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1

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

E-print Network

), phosphoenolpyruvate carbox- ykinase (PEPCK), citrate lyase (CL) and aspartate aminotransferase (AST). Malate dehydrogenase (MDH) was utilized as a coupling enzyme to detect either malate or oxaloacetate in the presence carbox- ykinase; CL; citrate lyase; MDH; malate dehydrogenase; 2D BN-PAGE; two-dimensional blue native

Appanna, Vasu

2

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

E-print Network

mediating nitrogen homeostasis in Pseudomonas fluorescens Sungwon Han a , Christopher Auger a , Varun P Keywords: Functional proteomics Nitrogen homeostasis Glutamate dehydrogenase Gel electrophoresis As glutamate and ammonia play a pivotal role in nitrogen homeostasis, their production is mediated by various

Appanna, Vasu

3

Separation of native allophycocyanin and R-phycocyanin from marine red macroalga Polysiphonia urceolata by the polyacrylamide gel electrophoresis performed in novel buffer systems.  

PubMed

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

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

2014-01-01

4

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

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

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

2014-01-01

5

Sodium dodecyl sulfate micelles in polyacrylamide gels.  

NASA Astrophysics Data System (ADS)

Polyacrylamide gels have been made in the presence of sodium dodecyl sulfate (SDS) micelles. The use of these gels for electrophoresis, after removal of the SDS, has demonstrated that the micelles modify the internal gel structure(R. Rill, B. Locke, Y. Liu, J. Dharia, D Van Winkle, Electrophoresis 17), 1304 (1996).. The phase diagram of SDS in buffer exhibits several transitions as a function of concentration and ionic strength. The SDS concentration used for templating gels is quite high, on the order of 20 - 30% by weight. This is the range in which the micellar system undergoes phase transitions. X-ray and light scattering experiments on gels with and without SDS and in SDS-buffer solutions were performed to understand the structure of the templated pores left after SDS removal. These experiments indicate the characteristic length scales associated with SDS micelles in gels changes from 3 to 15 nm as the gel and the SDS concentrations are varied.

van Winkle, David H.; Kettwig, Franz; Rill, Randolph L.; Liu, Yingjie; Locke, Bruce R.

1997-03-01

6

A Method for Activity Staining after Native Polyacrylamide Gel Electrophoresis Using a Coupled Enzyme Assay and Fluorescence Detection: Application to the Analysis of Several Glycolytic Enzymes  

Microsoft Academic Search

We describe a method for the detection of isoforms of several glycolytic enzymes by activity staining after native PAGE. The staining is based on coupled enzyme assays carried out on the gel after electrophoresis and is linked to the disappearance of NADH, which is visualized by fluorescence. This method offers reliable and sensitive detection for phosphoenolpyruvate carboxylase, PPi-dependent phosphofructokinase, and

Jean Rivoal; Christopher R. Smith; Trevor F. Moraes; David H. Turpin; William C. Plaxton

2002-01-01

7

Complications of Breast Augmentation with Injected Hydrophilic Polyacrylamide Gel  

Microsoft Academic Search

  Since 1997, the hydrophilic polyacrylamide gel (PAAG), an injectable alloplastic biomaterial, imported from the Ukraine has\\u000a been used for augmentation mammaplasty in China. There were twelve patients with various complications visiting our hospitals\\u000a after breast augmentation with injected hydrophilic polyacrylamide gel by other clinics, even though such procedures are not\\u000a performed in our clinical practices. The complications included four cases

Ning-xin Cheng; Yuan-lu Wang; Jin-huang Wang; Xiao-man Zhang; Hong Zhong

2002-01-01

8

Formation of magnetite nanoparticles in poly(acrylamide) gels  

Microsoft Academic Search

Magnetic gels with magnetite nanoparticles incorporated in a matrix of poly(acrylamide) gel were studied. Magnetite was synthesized through coprecipitation of Fe(II) and Fe(III) in the gel phase, in the solution of linear polymer and in aqueous solution without polymer in alkaline media. The effects of network structure and of the concentration of iron salts in the swollen networks on the

Sergey G Starodubtsev; Evheniy V Saenko; Maxim E Dokukin; Viktor L Aksenov; Vera V Klechkovskaya; Irina S Zanaveskina; Alexei R Khokhlov

2005-01-01

9

Activity staining of endoglucanases in polyacrylamide gels.  

PubMed

The endoglucanases of Penicillium funiculosum were analyzed for the presence of multiple forms using a modified version of the Congo red method. Postelectrophoretic slab gels were directly incubated in a solution of carboxymethylcellulose for a period as short as 15 min and then the activities were visualized by staining with Congo red. Ten distinct bands of clearances were obtained indicating the presence of at least as many multiple forms. PMID:1280921

Mathew, R; Rao, K K

1992-10-01

10

The instantaneous monitoring of polyacrylamide gels during electrophoresis.  

PubMed Central

The advantages of being able to see protein zones in a gel during electrophoresis (and hence before staining) are pointed out, and a method is described which depends on local increments of refractive index in these zones. The use of local increments of refractive index in polyacrylamide gels for measuring protein concentrations in zones during electrophoresis is briefly considered; it is found that such increments are greater than would be expected from the amount of protein when sodium dodecyl sulphate is present. The enhancement depends on conditions and time of running. This makes quantitative estimates difficult, but the sensitivity of detection of protein zones by observations based on refractive-index changes is greatly increased by this property of sodium dodecyl sulphate. Methods are described for making optically uniform gels (both with uniform and with graded concentrations of polyacrylamide), necessary for observation of small changes in refractive index. A simple dark-field system of observation is described. Examples are given showing protein samples observed with the system during electrophoresis and compared with the same gel stained with Coomassie Blue after completion of the run. Under optimal conditions the optical method is comparable in sensitivity with staining. With the proteins of lower mol.wt. (approx. 15000), the optical method is not so sensitive, becoming less sensitive with longer running time. This loss of sensitivity is greatly decreased by using more concentrated polyacrylamide gels, and graded gels are therefore more suitable for optical observation than are uniform gels. The observation of protein zones during electrophoresis adds nothing to the time needed for making a stained gel and gives much information long before it can be obtained from the stained gel. Images PLATE 1 PLATE 2 PMID:1008832

Elliott, A

1976-01-01

11

Jet injection into polyacrylamide gels: investigation of jet injection mechanics.  

PubMed

Jet injectors employ high-velocity liquid jets that penetrate into human skin and deposit drugs in the dermal or subdermal region. Although jet injectors have been marketed for a number of years, relatively little is known about the interactions of high-speed jets with soft materials such as skin. Using polyacrylamide gels as a model system, the mechanics of jet penetration, including the dependence of jet penetration on mechanical properties, was studied. Jets employed in a typical commercial injector, (orifice diameter: 152 microm, velocity: 170-180 m/s) were used to inject fluid into polyacrylamide gels possessing Young's moduli in the range of 0.06-0.77 MPa and hardness values in the range of 4-70 H(OO). Motion analysis of jet entry into polyacrylamide gels revealed that jet penetration can be divided into three distinct events: erosion, stagnation, and dispersion. During the erosion phase, the jet removed the gel at the impact site and led to the formation of a distinct cylindrical hole. Cessation of erosion induced a period of jet stagnation ( approximately 600 micros) characterized by constant penetration depth. This stage was followed by dispersion of the liquid into the gel. The dispersion took place by crack propagation and was nearly symmetrical with the exception of injections into 10% acrylamide (Young's modulus of 0.06 MPa). The penetration depth of the jets as well as the rate of erosion decreased with increasing Young's modulus. The mechanics of jet penetration into polyacrylamide gels provides an important tool for understanding jet injection into skin. PMID:15212923

Schramm-Baxter, Joy; Katrencik, Jeffrey; Mitragotri, Samir

2004-08-01

12

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

SciTech Connect

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.

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

1980-08-10

13

Basics and recent advances of two dimensional- polyacrylamide gel electrophoresis  

PubMed Central

Gel- based proteomics is one of the most versatile methods for fractionating protein complexes. Among these methods, two dimensional- polyacrylamide gel electrophoresis (2-DE) represents a mainstay orthogonal approach, which is popularly used to simultaneously fractionate, identify, and quantify proteins when coupled with mass spectrometric identification or other immunological tests. Although 2-DE was first introduced more than three decades ago, several challenges and limitations to its utility still exist. This review discusses the principles of 2-DE as well as both recent methodological advances and new applications. PMID:24735559

2014-01-01

14

Western Blot of Stained Proteins from Dried Polyacrylamide Gels  

NASA Technical Reports Server (NTRS)

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.

Gruber, Claudia; Stan-Lotter, Helga

1996-01-01

15

Polyacrylamide gels synthesized in the presence of surfactants  

NASA Astrophysics Data System (ADS)

The polymerization of acrylamide monomers in the presence of surfactant self-assemblies produces gels with variable pore architecture. Polyacrylamide gels were formed by polymerizing acrylamide plus a cross-linker in the presence of surfactants, which were then removed by soaking in distilled water. Gels formed in the presence of over 28% surfactant (by weight) formed clear, but became opaque upon removal of the surfactants. Other gels formed and remained clear. Several analytical techniques such as X-ray Scattering, Dynamic Rheology measurements, Optical Polarized Microscopy, and Atomic Force Microscopy (AFM) have been used to characterize the formation and the resulting gel structure. The surface morphology as imaged by AFM was studied by numerical scaling analysis. The surface morphology of the gels was studied by several one- and two-dimensional numerical scaling methods. The structure of the final gels were highly dependent on the amount of surfactant present during the formation of gels. At low surfactant concentrations (<25% by weight), the surfactant micelles are randomly distributed throughout the gel matrix. The average spacing between individual micelles is about 10 nm as indicated by X-ray scattering experiments. When the TTAB concentration is increased to moderate levels (25--28%), though the surfactant micelles are randomly distributed, a few surfactant-rich regions may form in the gel matrix. At high TTAB concentrations, phase separation of TTAB from the polymer leads to the formation of many surfactant-rich domains. A model for the gel structure based on symmetry and packing considerations for lattices of spheres of different concentrations was developed. This model was successfully used to interpret the physical observations, the experimental results, and the results from the scaling analysis. Highly porous gel networks with a high degree of mechanical strength have thus been synthesized. The controlled modification of gel structure provides new opportunities in the development of novel materials. A few areas of application include enzyme fixation for building biosensors, controlled release systems for drug delivery, support matrices for bio-molecule separation. The process of gel formation in the presence of unreactive surfactants can also be extended to alter the structure of other polymer materials.

Chakrapani, Mukundan

16

Investigations in x-ray computed tomography polyacrylamide gel dosimetry  

SciTech Connect

Polyacrylamide gels (PAGs) are radiosensitive materials currently under development for use as three-dimensional (3D) dosimeters in radiation therapy. Dose information is recorded in the gels and extracted through imaging. X-ray computed tomography (CT) has emerged as a promising gel imaging method due to a change in gel density that occurs upon irradiation. The accessibility of CT technology to cancer hospitals makes CT read out clinically attractive; however, the technique remains of limited clinical use due in part to poor dose resolution. This thesis investigates the use of CT for extracting dose information from PAGs with an overall goal of improving achievable dose resolution. Thesis results are divided into three studies: a gel-compositional study, a study of noise and dose resolution, and a digital filtering study. The first study investigates the effects of gel composition on PAG CT dose response and the underlying density change. Results indicate dramatic variation in CT dose response sensitivity and range with gel composition. A model is developed to describe gel density change with dose, revealing two fundamental properties of the density to dose response: the density change per unit polymer yield is highest for gels with low and high concentrations of crosslinking molecules, and dose response sensitivity is linearly dependent on the total concentration of monomers in the gel. The second study investigates strategies for minimizing noise in CT polymer gel dosimetry and assesses system performance. Specifically, the effects of phantom design, scanning technique, and voxel size on image noise are investigated and the effect of scanning protocol on imaging time is established. The dose resolution achievable with an optimized system is then calculated, given voxel size and imaging time constraints, and compared with published values for magnetic resonance imaging (MRI) and optical CT gel dosimetry. The third study investigates the potential of image filtering for improved dose resolution in CT gel dosimetry. CT image noise is characterized and appropriate filters are tested on a CT image of a PAG irradiated with a clinically relevant dose distribution. Filter performance is found to vary dramatically, with the best filters more than halving the dose resolution without significantly distorting the spatial distribution of dose. In summary, this thesis provides insight into the fundamental nature of PAG density to dose response, develops strategies for minimizing image noise, quantifies system performance, and demonstrates that digital image filtering is an effective tool to provide additional improvements to dose resolution.

Hilts, Michelle [Physics and Astronomy, University of British Columbia, British Columbia, Canada and Medical Physics, BC Cancer Agency, Vancouver Centre, British Columbia (Canada)]. E-mail: mhilts@bccancer.bc.ca

2005-09-15

17

Detection of proteins on polyacrylamide gels using calconcarboxylic acid.  

PubMed

We describe here a protein staining method in polyacrylamide gels with a new staining dye, 1-(2-hydroxy-4-sulfo-1-naphthylazo)-2-hydroxy-3-naphthoic acid (calconcarboxylic acid, NN). This method can be performed by both simultaneous and postelectrophoretic staining techniques. Simultaneous staining using 0.01% of NN in upper reservoir buffer eliminates the poststaining step, and thus enables detection of the proteins more rapidly and simply. In poststaining, proteins can be stained by a 30-min incubation of a polyacrylamide gel in 40% methanol/7% acetic acid solution of 0.05% NN. These techniques produced protein staining patterns identical to the ones obtained by the conventional poststaining with Coomassie blue R-250 (CB). NN staining can detect as little as 10 ng of bovine serum albumin by poststaining and 25 ng by simultaneous staining, compared to 50 ng detectable by CB poststaining. In comparing the relationship between band intensity and amount of protein, NN staining gave better linearity than CB staining. PMID:8250260

Hong, H Y; Choi, J K; Yoo, G S

1993-10-01

18

Characteristics of polyacrylamide gel with THPC and Turnbull Blue gel dosimeters evaluated using optical tomography  

NASA Astrophysics Data System (ADS)

The purpose of this study was to compare characteristics of radiochromic gel - Turnbull Blue gel (TB gel) with polymer gel - polyacrylamide gel and tetrakis hydroxymethyl phosphonium chloride (PAGAT) using optical tomography. Both types of gels were examined in terms of dose sensitivity, dose response linearity and background value of spectrophotometric absorbance. The calibration curve was obtained for 60Co irradiation performed on Gammacell 220 at predefined gamma dose levels between 0 and 140 Gy for TBG and 0-15 Gy for PAGAT. To measure relative dose distributions from stereotactic irradiation, dosimeters were irradiated on Leksell Gamma Knife Perfexion. The cylindrical glass housings filled with gel were attached to the stereotactic frame. They were exposed with single shot and 16 mm collimator by 65 Gy to a 50% prescription isodose for TB gel and 4 Gy to a 50% prescription isodose for PAGAT. Evaluations of dosimeters were performed on an UV-vis Spectrophotometer Helios ? and an optical cone beam homemade tomography scanner with a 16-bit astronomy CCD camera with a set of color filters. The advantages and potential disadvantages for both types of gel dosimeters were summarized. Dose distribution in central slice and measured profiles of 16 mm shot shows excellent correspondence with treatment planning system Leksell GammaPlan® for both PAGAT and Turnbull Blue gels. Gel dosimeters are suitable for steep dose gradient verification. An optical tomography evaluation method is successful. Dose response characteristics of TB gel and PAGAT gel are presented.

Pila?ová (Vávr?), Kate?ina; Kozubíková, Petra; Šolc, Jaroslav; Sp?vá?ek, Václav

2014-11-01

19

Probing the viscoelastic properties of polyacrylamide polymer gels in a wide frequency range.  

E-print Network

Probing the viscoelastic properties of polyacrylamide polymer gels in a wide frequency range. Y. Abidine,1, 2 V. M. Laurent,1, 2 R. Michel,1, 2 A. Duperray,3, 4, 5 L. I. Palade,6 and C. Verdier1, 2 1-Lyon, P^ole de Math´ematiques, F-69621 Villeurbanne, France (Dated: April 2, 2014) Polymer gels have been

Boyer, Edmond

20

Non-denaturing polyacrylamide gradient gel electrophoresis for the diagnosis of dysbetalipoproteinemia  

Microsoft Academic Search

Dysbetalipoproteinemia, an uncommon but highly atherogenic mixed hyperlipidemia due to the accumulation of remnants of triglyceride-rich lipoproteins, is characterized by cholesterol-enriched VLDL that migrates in the ? -position on agarose gels. The demonstration of a broad ? -band on agarose gel electrophoresis of plasma is an insensitive method and ultracentrifugation is an impractical method of diagnosing this condition. Non-denaturing polyacrylamide

Dirk J. Blom; Pamela Byrnes; Sheena Jones; A. David Marais

2003-01-01

21

Detection of cellulase activity in polyacrylamide gels using Congo red-stained agar replicas.  

PubMed

Bands that have cellulolytic activity are visualized after polyacrylamide gel electrophoresis by laying the slab gel on top of a thin sheet of 2% agar containing 0.1% carboxymethylcellulose. After a suitable incubation time, zones of carboxymethylcellulose hydrolysis are revealed by staining the agar replica with Congo red. PMID:6193735

Béguin, P

1983-06-01

22

Behaviour of Saccharomyces cerevisiae cells entrapped in a polyacrylamide gel and performing alcoholic fermentation  

Microsoft Academic Search

The behaviour of Saccharomyces cerevisiae cells entrapped in a polyacrylamide gel was studied during their continuous function in an ethanol-producing reactor. Polymerization destroys 40% to 80% of the cells, depending on their physiological state. A three day adaptation phase is required before ethanol production stabilizes and this phase corresponds to an increase in cell concentration in the gels and to

M. H. Siess; C. Divies

1981-01-01

23

Model and field studies of the degradation of cross-linked polyacrylamide gels used during the revegetation of slate waste  

Microsoft Academic Search

Cross-linked polyacrylamide gels are increasingly being used in environmental restoration schemes and horticulture as a means of enhancing water supply to plants. However, the environmental impact of cross-linked polyacrylamide gel deployment in soil remains poorly understood. This study assessed the chemical, physical and biological properties of new and field-conditioned cross-linked polyacrylamide gels. Both monomeric acrylamide (11 ?g l?1) and acrylic

Peter J. Holliman; Jennifer A. Clark; Julie C. Williamson; Davey L. Jones

2005-01-01

24

Sensitive Reverse Staining of Bacterial Lipopolysaccharides on Polyacrylamide Gels by Using Zinc and Imidazole Salts  

Microsoft Academic Search

We present a new method for visualizing bacterial lipopolysaccharides (LPS)\\/lipooligosaccharides (LOS) electrophoresed in sodium dodecyl sulfate–polyacrylamide gels. After electrophoresis, gels are washed in boiling water to appreciably remove remaining electrophoresis reagents, then incubated in 10 mmzinc sulfate for 15 min, and subsequently immersed in 0.2mimidazole for 3 min. As a result, zinc salts precipitate all over the gel surface except

Eugenio Hardy; Elder Pupo; Lila Castellanos-Serra; Jesus Reyes; Carlos Fernández-Patrón

1997-01-01

25

Dna electrophoresis in photopolymerized polyacrylamide gels on a microfluidic device  

E-print Network

DNA gel electrophoresis is a critical analytical step in a wide spectrum of genomic analysis assays. Great efforts have been directed to the development of miniaturized microfluidic systems (“lab-on-a-chip” systems) to perform low-cost, high...

Lo, Chih-Cheng

2009-05-15

26

Fluorography of tritium-labeled proteins in silver-stained polyacrylamide gels  

SciTech Connect

Silver-staining of polyacrylamide gel electrophoresis (PAGE)-separated proteins allows sensitive detection of proteins but severely reduces the ability to detect weak beta-emitters present in the protein band. A simple procedure is described in which silver can be removed from a silver-stained PAGE gel (deargentation) using photographic fixer, and the silver-free gel can be enhanced and used for fluorography. A quantitative study of sensitivity is reported for /sup 3/H-labeled bovine serum albumin with a one-dimensional sodium dodecyl sulfate-PAGE slab gel.

Kulcsar, P.; Prestwich, G.D.

1988-05-01

27

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

Microsoft Academic Search

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

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

28

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

E-print Network

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

Paris-Sud XI, Université de

29

Use of acridine orange staining for the detection of rotavirus RNA in polyacrylamide gels  

Microsoft Academic Search

Acridine orange is a metachromatic intercalator used extensively in histochemistry to differentiate double- from single-stranded (ds, ss) nucleic acid by the emission of green and red fluorescence, respectively, under ultraviolet light. In the present study we standardised a protocol in order to use acridine orange to detect rotavirus ds RNA in polyacrylamide gels and compared it to silver and ethidium

Flávio Lauretti; Fernando Lucas de Melo; Fabr??cio José Benati; Eduardo de Mello Volotão; Norma Santos; Rosa Elisa Carvalho Linhares; Carlos Nozawa

2003-01-01

30

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

PubMed

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

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

1984-03-01

31

Identification of Frankia Strains by Two-Dimensional Polyacrylamide Gel Electrophoresis  

PubMed Central

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

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

1984-01-01

32

Method for the detection and differentiation of cellulase components in polyacrylamide gels  

SciTech Connect

Endoglucanase and exoglucanase components of cellulase can be detected and differentiated after polyacrylamide gel electrophoresis by performing activity stains. Endoglucanase activity was visualized in carboxymethyl cellulose agar replicas of gels by staining with Congo red. General ..beta..-1,4-glucanase activity was located by soaking the gel in a solution of NaBH/sub 4/-reduced cellulo-oligosaccharides, and detecting the formation of reducing sugars by reaction with triphenyl tetrazolium chloride. Endoglucanases are active in both assays, while exoglucanases can be distinguished by their activity in the cellulo-oligosaccharide assay only. This methodology has facilitated the purification and characterization of cellulase components from Trichoderma reesei and Microbispora bispora.

Bartley, T.D.; Murphy-Holland, K.; Eveleigh, D.E.

1984-01-01

33

A method for the detection and differentiation of cellulase components in polyacrylamide gels.  

PubMed

Endoglucanase and exoglucanase components of cellulase can be detected and differentiated after polyacrylamide gel electrophoresis by performing activity stains. Endoglucanase activity was visualized in carboxymethyl cellulose agar replicas of gels by staining with Congo red. General beta-1,4-glucanase activity was located by soaking the gel in a solution of NaBH4-reduced cellulooligosaccharides, and detecting the formation of reducing sugars by reaction with triphenyl tetrazolium chloride. Endoglucanases are active in both assays, while exoglucanases can be distinguished by their activity in the cellulo-oligosaccharide assay only. This methodology has facilitated the purification and characterization of cellulase components from Trichoderma reesei and Microbispora bispora. PMID:6207744

Bartley, T D; Murphy-Holland, K; Eveleigh, D E

1984-07-01

34

Pressure-induced volume phase transition of polyacrylamide gels in acetone-water mixtures  

NASA Astrophysics Data System (ADS)

Equilibrium swelling curves of ionized polyacrylamide gels immersed in acetone-water mixtures were measured as a function of pressure up to pressures of 300 MPa. The gels, which shrank at atmospheric pressure, underwent an abrupt volume change (pressure-induced volume phase transition) from a shrunken state to a swollen state at the transition pressure. The transition pressure increased with an increase of acetone concentration. The pressure-induced volume phase transition can be interpreted by taking account of the free-energy change ?V?P between swollen (hydrated) and shrunken (dehydrated) states. The ?V represents the difference between the molar volume of water structured around hydrophilic groups of polyacrylamide chains and that of free water in the bulk mixtures. The estimated value of ?V is -3.3 mL/mol, which qualitatively agrees with that obtained from the experiments of denaturation of proteins. The pressure-induced volume phase transition is generally expected in many hydrogels.

Kato, Eiji

2000-07-01

35

Complications from Repeated Injection or Puncture of Old Polyacrylamide Gel Implant Sites: Case Reports  

Microsoft Academic Search

Polyacrylamide gel has been used for soft tissue augmentation outside the United States since 1997. Despite some adverse events,\\u000a the long duration of the augmentation and the tangible filling effect has increased its use in Asia and the Middle East. In\\u000a this era of mesotherapy and fillers, patients are more likely than ever to have additional injections. The response of

El-Sayed Ibrahim El-Shafey

2008-01-01

36

Increased 131I accumulation in the polyacrylamide hydrophilic gel used for breast augmentation.  

PubMed

A 37-year-old woman with papillary thyroid cancer received repeat 131I therapy. The first posttherapy scan revealed only activity in the neck. However, both the second and third posttherapy scans showed intense activity in the anterior lower chest bilaterally, suggestive of breast uptake. However, the SPECT/CT images demonstrated that the iodine activity was not located in the breast tissue. Instead, the activity was inside the polyacrylamide hydrophilic gels she received 10 years ago for breast augmentation. PMID:24566417

Lv, Jing; Qu, Yumin; Zhang, Min; Pan, Yu; Zhang, Yifan

2014-04-01

37

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

PubMed

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

Hochstrasser, D F; Merril, C R

1988-01-01

38

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

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

39

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

E-print Network

microscopy/microscope; BN-PAGE, blue native-polyacrylamide gel electrophoresis; CCB, Coomassie brilliant blue microscopy of negatively stained samples, blue native- and sodium dodecyl sulphate-polyacrylamide gel elec. Keywords: Blue native-polyacrylamide gel electrophoresis, cross- linking, G protein-coupled receptor

Palczewski, Krzysztof

40

Accommodating brightness and exposure levels in densitometry of stained polyacrylamide electrophoresis gels  

SciTech Connect

Flatbed scanner densitometers can be operated under various illumination and recording exposure levels. In this work, we show that optical density measurement accuracy, sensitivity, and stability of stained polyacrylamide electrophoresis gel densitometry are crucially dependent on these two factors (brightness and exposure level), notwithstanding that the source is monochromatic, spatially uniform, and the measurements are made using an accurately calibrated step wedge in tandem. We further outline a method to accommodate the intensity deviations over a range of illumination and exposure levels in order to maintain sensitivity and repeatability in the computed optical densities. Comparisons were also made with results from a commercial densitometer.

Tan, Han Yen; Ng, Tuck Wah; Liew, Oi Wah

2010-03-20

41

Temperature dependence of free volume of polyacrylamide gels studied by positron lifetime measurements  

NASA Astrophysics Data System (ADS)

Changes of positronium (Ps) cavity radii in polyacrylamide and poly( N-isopropylacrylamide) gels were studied from 120 to 300 K by positron lifetime technique and it has been shown that the Ps cavity radius in the hydrogels changes by three or four stages. Temperature dependence of the Ps cavity radius exhibits variations similar to common polymers around the glass transition temperature. Hydrophilicity of the polymer chains significantly affects the Ps cavity radius just below 273 K. These results suggest an important role of free volume on the state of water in hydrogels.

Ito, Kenji; Ujihira, Yusuke; Yamashita, Takashi; Horie, Kazuyuki

2000-06-01

42

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

E-print Network

and therefore poor contrast (e.g. SDS, ampholytes, amino acids, Tris). In the second phase, the gels1 Silver staining of proteins in polyacrylamide gels: a general overview Thierry Rabilloud Cycle Cellulaire, INSERM U309 DBMS / BMCC CEN-G, 17 rue des martyrs F-38054 GRENOBLE CEDEX 9 FRANCE

Boyer, Edmond

43

Partitioning and diffusion of proteins and linear polymers in polyacrylamide gels.  

PubMed Central

The equilibrium partition coefficient (K) and diffusion coefficient (Dgel) of two proteins and two linear polymers were measured as a function of polymer content of a 2.7% cross-linked polyacrylamide (PA) gel. The gel concentration, expressed as a volume percentage of PA in the gel (phi), varied between 0 and 14%. The measurements were made by fluorescence spectroscopy; fluorescent dyes were covalently attached to the macromolecules. The dependence of K on phi for the proteins agrees with a model of the gel network as randomly placed, impenetrable rods. The diffusion data are interpreted in terms of an effective medium theory for the mobility of a sphere in a Brinkman fluid. Using values of the Brinkman parameter in the literature, the effective medium model with no adjustable parameters fits the diffusion data for the proteins very well but underpredicts Dgel for the linear polymers. The gel effect on partitioning is significantly greater than that on diffusion. The permeability (KDgel) of bovine serum albumin decreased by 10(3) over the range phi = 0 --> 8%, and the ratio of permeabilities for ribonuclease compared to BSA increased from 2 to 30. Images FIGURE 1 PMID:8785307

Tong, J; Anderson, J L

1996-01-01

44

A rapid and effective method for silver staining of PCR products separated in polyacrylamide gels.  

PubMed

With the development of molecular quantitative genetics, particularly, genetic linkage map construction, quantitative trait loci mapping or genes fine mapping and association analysis etc., more and more PCR products separated in polyacrylamide gels need to be silver-stained. However, conventional silver-staining procedures are complicated and time-consuming as they require a lot of preparation and handling of several solutions prior to use. In this study, a simple and rapid protocol for silver staining of PCR products was developed. The number of steps was reduced compared to conventional protocols, thus achieving detection of PCR products in 7 min, saving time and resources. Fixation and staining solution and developing solution in present staining procedure allowed a reutilization for 12 and 8 times, respectively, reducing the cost greatly. Meanwhile, the sensitivity was significantly improved with the improved method and the minimum of 0.097 ng/?L of DNA amount can be detected in denaturing polyacrylamide gel. The protocol developed in this study will facilitate the development of molecular quantitative genetics. PMID:24789566

Liang, Qingzhi; Wen, Dingqing; Xie, Jianghui; Liu, Liqin; Wei, Yongzan; Wang, Yicheng; Shi, Shengyou

2014-09-01

45

Sensitive detection of transglycosylating activity of xyloglucan endotransglycosylase\\/hydrolase (XTH) after isoelectric focusing in polyacrylamide gels  

Microsoft Academic Search

The paper describes a sensitive and rapid zymogram technique for detection of transglycosylating activity (XET) of xyloglucan endotransglycosylase\\/hydrolase (XTH; EC 2.4.1.207) in polyacrylamide isoelectric focusing gels. After the electrophoresis, the separating gel was overlaid and incubated with an agarose detection gel containing XET substrates: tamarind-seed xyloglucan as the glycosyl donor and sulphorhodamine-labeled xyloglucan-derived oligosaccharides (XGO-SRs) as the glycosyl acceptors. The

Vladimír Farkaš; Fairouz Ait-Mohand; Eva Stratilová

2005-01-01

46

Migration of implants: a problem with injectable polyacrylamide gel in aesthetic plastic surgery.  

PubMed

Polyacrylamide gel (PAAG) has been used as a soft tissue filler material for cosmetic purposes in Europe and China since 1997. The various complications of PAAG have been reported. A total of 15 patients who received PAAG injections at other institutions were treated for gel migration in the authors' hospitals. During treatment, the authors found that the injected PAAG had not formed capsules within the muscle and was encapsulated only by thin fibrous tissue in skin and mammary glands. Consequently, the filler material migrated easily because of muscular activity or the influence of gravity, especially when the capsule was broken by incorrect massage or incidental force. It is suggested that PAAG should not be injected into muscular tissue or subcutaneous areas with active movement, such as joints and muscles involved in facial expression with thin skin. After years of gel implantation, the thinned capsule may result in an increasing incidence of this complication. Management and some clinical findings in relation to the complication also are discussed. PMID:16547628

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

2006-01-01

47

Data-base techniques for multiple two-dimensional polyacrylamide gel electrophoresis analyses.  

PubMed

Two-dimensional protein electrophoresis can benefit from a powerful set of computer-supported image processing and data structure/management procedures. Detection of quantitative differences is complicated by local inhomogeneities in the polyacrylamide base; biochemical changes and variations in temperature and preparative technique also make the between-gel density and x-y coordinate correspondences quite imprecise. The program presented here provides local alignment and computer-controlled variable "flicker" rates for multiple gels, with use of an interactive display system. Manual spot densitometry, referred to a National Bureau of Standards density wedge, can be complemented by a set of automatic densitometry routines for previously established lists of spots. The ability to establish a set of local landmarks, either by included standards or user identification, provides a basis for automatic n-way gel comparison for subsets or for the entire set of spots. Automatic segmentatin algorithms allow isolatin of spots and separation of touching and partially overlapping regions. Various analytical and statistical facilities are part of the user's access to the interactively developed data base. The data-structure and image-manipulation techniques developed here allow for user-directed and heuristic comparisons with online presentation of intermediate and final results. PMID:6996868

Lipkin, L E; Lemkin, P F

1980-09-01

48

Immunoblots and plasmid fingerprints compared with serotyping and polyacrylamide gel electrophoresis for typing Clostridium difficile.  

PubMed Central

Two new methods for typing Clostridium difficile, immunoblotting and plasmid fingerprinting, were compared with serotyping and polyacrylamide gel electrophoresis (PAGE). Of these methods, immunoblotting was found to be the most valuable for use in a comprehensive typing system. More groups could be distinguished by immunoblotting than by serotyping or PAGE. Immunoblotting results were also more reproducible and distinctive than results by PAGE. Plasmid fingerprinting was an excellent marker for plasmid-bearing strains, but it had limited use because many isolates lacked plasmids. A unique plasmid profile observed for one group of isolates correlated with differences in phenotypic characteristics resolved by immunoblot analysis but not by serotyping or PAGE. Preliminary attempts to correlate typing results with pathogenicity of isolates were not successful but underscored the need for future studies to include careful assessment of the clinical significance of isolates. Images PMID:3343314

Mulligan, M E; Peterson, L R; Kwok, R Y; Clabots, C R; Gerding, D N

1988-01-01

49

Globin chain separation by SDS polyacrylamide gel electrophoresis. Simple screening method for elongated hemoglobin chains.  

PubMed

A simple method for the separation of hemoglobin chains from hemolysate or globin, by sodium dodecyl sulfate polyacrylamide gel electrophoresis, is described. The alpha, beta, and gamma chains can be clearly separated from each other. The alpha chain has the highest mobility, the beta chain has a slower mobility than the gamma chain, while the delta chain has about the same mobility as the beta chain. Hemoglobins with elongated chains can easily be detected by this method. Tak-beta, elongated by 11 residues, moves much more slowly than betaA but is much faster than alpha Constant Spring which is elongated by 31 residues. Screening of several individuals with slow-moving hemoglobins using this method led to the finding of a case with Hb Tak-beta thalassemia and other carriers of Hb Tak. PMID:659552

Lie-Injo, L E; Solai, A; Ganesan, J

1978-06-01

50

Phosphoprotein staining for sodium dodecyl sulfate-polyacrylamide gel electrophoresis using fluorescent reagent morin hydrate.  

PubMed

A fluorescence-based stain with 3,5,7,2',4'-pentahydroxyflavone (morin hydrate, MH) was designed to stain phosphoproteins in one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Al(3+) was applied as a "fixed bridge," providing an efficient energy transfer channel between phosphoprotein and MH, to produce a strong fluorescent complex for the determination of phosphoprotein. As little as 62.5ng of ?-casein (7 or 8 phosphates) and ?-casein (5 phosphates), 125ng of ovalbumin (2 phosphates), and ?-casein (1 phosphate) could be visualized with a wide linear dynamic range. In comparison with conventional methods, MH stain is a time-saving method that takes just 90min. It also has good compatibility with routine protein stainings such as Coomassie Brilliant Blue R (CBBR) and SYPRO Ruby for total protein analysis. PMID:23274386

Wang, Xu; Hwang, Sun-Young; Cong, Wei-Tao; Jin, Li-Tai; Choi, Jung-Kap

2013-04-01

51

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

PubMed Central

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

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

2013-01-01

52

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

SciTech Connect

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.

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

1986-01-01

53

Agarose and Polyacrylamide Gel Electrophoresis Methods for Molecular Mass Analysis of 5–500 kDa Hyaluronan  

PubMed Central

Agarose and polyacrylamide gel electrophoresis systems for the molecular mass-dependent separation of hyaluronan (HA) in the size range of approximately 5–500 kDa have been investigated. For agarose-based systems, the suitability of different agarose types, agarose concentrations, and buffers systems were determined. Using chemoenzymatically synthesized HA standards of low polydispersity, the molecular mass range was determined for each gel composition, over which the relationship between HA mobility and logarithm of the molecular mass was linear. Excellent linear calibration was obtained for HA molecular mass as low as approximately 9 kDa in agarose gels. For higher resolution separation, and for extension to molecular masses as low as approximately 5 kDa, gradient polyacrylamide gels were superior. Densitometric scanning of stained gels allowed analysis of the range of molecular masses present in a sample, and calculation of weight-average and number-average values. The methods were validated for polydisperse HA samples with viscosity-average molecular masses of 112, 59, 37, and 22 kDa, at sample loads of 0.5 µg (for polyacrylamide) to 2.5 µg (for agarose). Use of the methods for electrophoretic mobility shift assays was demonstrated for binding of the HA-binding region of aggrecan (recombinant human aggrecan G1-IGD-G2 domains) to a 150 kDa HA standard. PMID:21684248

Bhilocha, Shardul; Amin, Ripal; Pandya, Monika; Yuan, Han; Tank, Mihir; LoBello, Jaclyn; Shytuhina, Anastasia; Wang, Wenlan; Wisniewski, Hans-Georg; de la Motte, Carol; Cowman, Mary K.

2011-01-01

54

A shortcut organic dye-based staining method for the detection of DNA both in agarose and polyacrylamide gel electrophoresis.  

PubMed

In this study, we describe a brief, sensitive and safe organic dye-based staining method for the visualization of DNA both in agarose and polyacrylamide gels by using Victoria Pure Blue BO (VPBBO). Down to 0.8-1.6 ng of ? DNA/HindIII markers in agarose gels and 0.4-0.8 ng of pUC18 DNA/Mspl markers in polyacrylamide gels can be successfully detected within 15 and 10 min by the new developed technique, respectively. Moreover, the mechanism of the VPBBO staining was investigated and further confirmed by electrospray ionization mass spectrometry (ESI-MS) and molecular docking. The results indicated that the interaction between VPBBO and DNA is mainly due to groove binding. PMID:23296513

Cong, Weitao; Chen, Mao; Zhu, Zhongxin; Liu, Zhiguo; Nan, Jia; Ye, Weijian; Ni, Maowei; Zhao, Ting; Jin, Litai

2013-02-21

55

Loop-mediated isothermal amplification of a single DNA molecule in polyacrylamide gel-based microchamber.  

PubMed

Loop-mediated isothermal amplification (LAMP) is an original nucleic acid amplification method established by Notomi et al. LAMP is performed under isothermal condition, employing only a basic reaction protocol and minimal supporting electronics. These requirements prove to be viable for exploring the avenues to down-scale this biological reaction for Lab-on-a-chip application. Hence here, we developed a novel technique for fluorescent imaging of LAMP at a single molecule level. The experiment was conducted in a polyacrylamide (PAA) gel-based microchamber where a single DNA template, freely suspended in a solution containing primers and polymerase was initially encapsulated. In order to activate the amplification reaction, a microheater regulated by an automatic computerized feedback system was used for localized heating. This microchamber-based approach for LAMP demonstrated the effective exploitation of minute amount of templates and primers, and the overall reduction in LAMP detection time. An average efficiency of 80% was evaluated for conducting DNA amplification after 50 min of incubation at 65 degrees C. As the total time for reaction including detection can be completed in less than 1 h, this one-step, direct observation method displays the potential as a simple alternative to conventional techniques for genetic analysis and diagnosis in the clinical laboratory. PMID:18302022

Lam, Liza; Sakakihara, Shouichi; Ishizuka, Koji; Takeuchi, Shoji; Arata, Hideyuki F; Fujita, Hiroyuki; Noji, Hiroyuki

2008-08-01

56

Sodium dodecyl sulfate-polyacrylamide gel protein electrophoresis of freshwater photosynthetic sulfur bacteria.  

PubMed

Sodium dodecyl sulfate-polyacrylamide gel protein electrophoresis (SDS-PAGE) was carried out using different bacterial strains of the photosynthetic sulfur bacteria Chlorobium, Thiocapsa, Thiocystis, and Chromatium cultured in the laboratory, and the natural blooms in two karstic lakes (Lake Cisó and Lake Vilar, NE Spain) where planktonic photosynthetic bacteria (purple and green sulfur bacteria) massively developed accounting for most of the microbial biomass. Several extraction, solubilization, and electrophoresis methods were tested to develop an optimal protocol for the best resolution of the SDS-PAGE. Protein composition from different water depths and at different times of the year was visualized within a molecular mass range between 100 and 15 kDa yielding up to 20 different protein bands. Protein banding patterns were reproducible and changed in time and with depth in agreement with changes in photosynthetic bacteria composition. When a taxonomically stable community was followed in time, differences were observed in the intensity but not in the composition of the SDS-PAGE banding pattern. Three environmental variables directly related to the activity of sulfur bacteria (light, oxygen, and sulfide concentrations) had a significant effect on protein banding patterns and explained 33% of the variance. Changes in natural protein profiles of the bacterial blooms agreed with changes in species composition and in the in situ metabolic state of the populations. PMID:20524118

Osuna, M Begoña; Casamayor, Emilio O

2011-01-01

57

Ribosomal ribonucleic acids of cultured cells: A preliminary survey of differences among mammalian species detectable by polyacrylamide gel electrophoresis  

Microsoft Academic Search

Summary  Ribosomal ribonucleic acids (rRNA's) of cultured cells from various species were compared by polyacrylamide gel electrophoresis.\\u000a Electrophoretic mobility of the 28 S RNA component varied according to species. Human cell 28 S rRNA was distinguishable from\\u000a that of monkey cells. The mobility of chimpanzee 28 S rRNA was identical to that from human cells, but different from that\\u000a of monkey

M. E. Soergel; F. L. Schaffer

1972-01-01

58

Simple and cost effective apparatus for silver staining of polyacrylamide gels with sequential reagents addition and real time monitoring.  

PubMed

Highly reproducible results in molecular biology depend a lot on effective staining and destaining methods. Silver staining of polyacrylamide DNA and protein gel has been adopted widely in the molecular biology laboratories for detecting a very low nanogram range of sample. An efficient staining of a polyacrylamide gel requires a number of well controlled and highly sensitive steps that often becomes tiresome when done manually or when there are a number of gels to be stained simultaneously. Since, silver staining is a multistep procedure that requires proper fixation and exchange of substance, a reliable protocol is necessary and a simple apparatus may be an added advantage to carry out the steps with ease and safety. Here, we describe a simple and cost effective device made from off-the-shelf components for some established silver staining protocols. Staining is done on a tray while six graduated bottles with a liquid delivery stopcock each, is connected to the tray through silicon tubing. The used up solution is drained off completely from the staining tray through a liquid outlet stopcock using vacuum pressure. The system is fixed with a camera connected to a computer for effective control of the staining process in each step. The apparatus provides the researchers with efficient staining and real time monitoring of gels without the need for handling toxic chemicals. PMID:24388443

Maurye, Praveen; Basu, Arpita; Gupta, Angshuman

2014-06-01

59

Gradient polyacrylamide gel electrophoresis in presence of sodium dodecyl sulfate: a practical approach to muscle contractile and regulatory proteins.  

PubMed

Two gradient systems for polyacrylamide gel electrophoresis (PAGE) in the presence of sodium dodecyl sulfate (SDS) are described, with emphasis on improvements accumulated over two decades of studies on contractile proteins and regulatory enzymes from smooth muscle. The first "big slab" system utilizes 18 x 20 x 0.1 cm3 gels and a 10-18% acrylamide gradient, optimized for a high resolution of 10 to 500 kDa polypeptides. Eight (or more) gels are cast simultaneously with a gradient formation from "bottom to top" and 20% glycerol is added to the 18% acrylamide solution. The second "minislab" system represents an improved version of the system of Matsudaira and Burgess (Anal. Biochem. 1978, 87, 386-396), with 8 x 10 x 0.05 cm3 gels and 5-15% or 9-18% acrylamide gradient ranges. They are cast from "top to bottom" in 28-piece batches also with the addition of glycerol for improved gradient formation. Both types of gels can also be cast individually using a specially designed pestle-type gradient maker. For gel destaining, a convenient continuous hydrodynamic destainer is also described. PMID:7859701

Sobieszek, A

1994-01-01

60

Phys. Med. Biol. 44 (1999) 18751884. Printed in the UK PII: S0031-9155(99)02424-0 Dynamics of polymerization in polyacrylamide gel (PAG)  

E-print Network

of polymerization in polyacrylamide gel (PAG) dosimeters: (II) modelling oxygen diffusion S J Hepworth, M O Leach to ionizing radiation, undergo a polymerization reaction. This changes, locally, the nuclear magnetic-bis-acrylamide (MBA) dispersed in a 5% gelatin/89% water gel matrix. 0031-9155/99/081875+10$30.00 © 1999 IOP

Doran, Simon J.

61

Photo-initiated cross-linked polyacrylamide gels for microdevice electrophoresis  

E-print Network

complex micro-channel network. The rate of photo-initiation in the free radical gel polymerization reaction, however, can exert a strong influence on the resulting gel structure. Experimental data on separation resolution of single stranded DNA (ss...

Agrawal, Shilpa

2005-08-29

62

Supramolecular gel electrophoresis of acidic native proteins.  

PubMed

Amphiphilic tris-urea molecules self-assemble into a supramolecular hydrogel in tris(hydroxymethyl)aminomethane-glycine buffer. The supramolecular hydrogel is used as a matrix for the electrophoresis of acidic native proteins, in which proteins are separated based on their isoelectric points rather than their molecular weights. The proteins remain in their native forms during migration, and their activities are retained after electrophoresis. Glucoside substituents on the amphiphilic tris-urea molecule allow for the affinity electrophoresis of a carbohydrate-binding protein to be performed. The proteins can be efficiently recovered from the supramolecular hydrogel using a simple procedure. This is a major advantage of using this noncovalent, self-assembled material. PMID:25147927

Munenobu, Kanako; Hase, Takayuki; Oyoshi, Takanori; Yamanaka, Masamichi

2014-10-01

63

The fractionation of high-molecular-weight ribonucleic acid by polyacrylamide-gel electrophoresis  

PubMed Central

1. Gels were prepared with recrystallized acrylamide and bisacrylamide. Electrophoresis was in tris–sodium acetate–EDTA buffer for 0·5 to 3hr. Gels were scanned at 280 or 265m?. Techniques are described for slicing and radioactive counting. 2. The mobility of RNA was inversely related to the sedimentation coefficient and varied with gel concentration. Electrophoresis in 2·2–2·6% gels gives a fractionation similar to density-gradient centrifugation. It shows the two ribosomal RNA components, the 45s precursor, transfer RNA and minor components. In 5% and 7·5% gels, 4s and 5s RNA separated and ribosomal RNA was excluded. 3. The resolution is greater and more detailed than by centrifugation, and many samples can be analysed simultaneously and rapidly. PMID:5339944

Loening, U. E.

1967-01-01

64

Typing and subtyping of haptoglobin from native serum using disc gel electrophoresis in alkaline buffer: application to routine screening.  

PubMed

A method with which the six common phenotypes of human haptoglobin can be identified using unseparated serum is described. In contrast to other reported methods, both typing and subtyping of haptoglobin can be performed by polyacrylamide gel electrophoresis in alkaline buffer using 0.1-4.0 microliter of native serum with hemoglobin added. Haptoglobin-hemoglobin complexes are visualized by their peroxidase activity using benzidine and barium peroxide. This relatively inexpensive and fast method seems particularly well suited for the typing and subtyping of haptoglobin from minute amounts in large series of sera and other body fluids and thus may be useful in medical genetics and forensic medicine. PMID:6496936

Linke, R P

1984-08-15

65

Activity staining of cellulases in polyacrylamide gels containing mixed linkage beta-glucans.  

PubMed

Endoglucanase and cellobiohydrolase components of thermophilic cellulases can be detected in situ after gel electrophoresis in the presence of sodium dodecyl sulfate by incorporating a mixed linkage beta-glucan (barley beta-glucan, lichenan) in the separation gel. Zymograms are prepared after a renaturation treatment and incubation by staining the gel with Congo red. This method is suitable for the detection of beta-glucanases with different substrate specificities cleaving beta-1,4-, beta-1,4-1,3-, or beta-1,3-glucans. Cellobiohydrolase activities can be detected by adding 4-methylumbelliferyl-beta-D-cellobioside to the incubation buffer. The gels are subsequently stained with Coomassie blue to establish identical molecular weights of beta-glucanase and protein bands. Applications of this technique for the comparison of cellulases and for the identification of cellulase components expressed from recombinant clones are presented. PMID:2445222

Schwarz, W H; Bronnenmeier, K; Gräbnitz, F; Staudenbauer, W L

1987-07-01

66

Electrophoretic analysis of plant cysteine and serine proteinases using gelatin-containing polyacrylamide gels and class-specific proteinase inhibitors.  

PubMed

Inclusion of gelatin in polyacrylamide gels provides a sensitive way of detecting multiple proteolytic activities in crude extracts from any source. The present study describes a method allowing discrimination between cysteine and serine proteinases in plant extracts, using gelatin-containing gels in combination with class-specific proteinase inhibitors. Preincubation of extracts with 4 mM phenylmethylsulfonyl fluoride, a serine proteinase inhibitor, or with 25 microM L-trans-epoxysuccinyl-L-leucylamido(4-guanidino) butane, a cysteine proteinase inhibitor, allowed the identification of enzymes from both classes in extracts of tomato fruit and papaya latex. The efficiency of the two low molecular weight inhibitors used was very high, and the irreversibility of the inhibiting effect was maintained during electrophoresis conducted in the presence of sodium dodecyl sulfate. The analytic procedure described here, with a detection threshold of less than 100 pg enzyme, is the first that allows quick and accurate discrimination of plant cysteine and serine proteinases separated in electrophoretic gels. This simple and rapid technique could be of interest for studying the evolution of class-specific proteinases in plant extracts during various developmental, physiological, and pathogenic processes. It is also potentially applicable to the majority of eucaryotic and procaryotic systems. PMID:8462522

Michaud, D; Faye, L; Yelle, S

1993-01-01

67

Comparison of the influence of inorganic salts on the NMR dose sensitivity of polyacrylamide-based gel dosimeter  

NASA Astrophysics Data System (ADS)

On the NMR dose sensitivities of polyacrylamide-based gel dosimeters irradiated by X-ray, the additive effect of various inorganic salts (electrolytes) is investigated. Among the various combination of cations (Li+, Na+, K+, Mg2+, Ca2+, Sr2+, Ba2+, Zn2+ and Al3+) and anions (Cl-, NO-3 and SO2-4), MgCl2 is shown to be the most effective sensitizer. In the result, it is suggested that the extent of the increase of the dose sensitivity may correlate to the hydration power of cations rather than anions. Contrary to the dose sensitivity enhancement, the depression of melting point caused by the additives is also pointed out.

Hayashi, S.-I.; Kawamura, H.; Usui, S.; Tominaga, T.

2013-06-01

68

Rheological and mechanical behavior of polyacrylamide hydrogels chemically crosslinked with allyl agarose for two-dimensional gel electrophoresis.  

PubMed

Two-dimensional (2-D) gel electrophoresis currently represents one of the most standard techniques for protein separation. In addition to the most commonly employed polyacrylamide crosslinked hydrogels, acrylamide-agarose copolymers have been proposed as promising systems for separation matrices in 2-D electrophoresis, because of the good resolution of both high and low molecular mass proteins made possible by careful control and optimization of the hydrogel pore structure. As a matter of fact, a thorough understanding of the nature of the hydrogel pore structure as well as of the parameters by which it is influenced is crucial for the design of hydrogel systems with optimal sieving properties. In this work, a series of acrylamide-based hydrogels covalently crosslinked with different concentrations of allyl agarose (0.2-1%) is prepared and characterized by creep-recovery measurements, dynamic rheology and tensile tests, in the attempt to gain a clearer understanding of structure-property relationships in crosslinked polyacrylamide-based hydrogels. The rheological and mechanical properties of crosslinked acrylamide-agarose hydrogels are found to be greatly affected by crosslinker concentration. Dynamic rheological tests show that hydrogels with a percentage of allyl agarose between 0.2% and 0.6% have a low density of elastically effective crosslinks, explaining the good separation of high molecular mass proteins in 2-D gel electrophoresis. Over the same range of crosslinker concentration, creep-recovery measurements reveal the presence of non-permanent crosslinks in the hydrogel network that justifies the good resolution of low molecular mass proteins as well. In tensile tests, the hydrogel crosslinked with 0.4% of allyl agarose exhibits the best results in terms of mechanical strength and toughness. Our results show how the control of the viscoelastic and the mechanical properties of these materials allow the design of mechanically stable hydrogels with improved sieving ability in protein electrophoresis over a wide range of molecular masses. PMID:24368174

Suriano, R; Griffini, G; Chiari, M; Levi, M; Turri, S

2014-02-01

69

Optimized method for rapid protein electroblotting Protein electroblotting is a common method for transferring proteins out of a polyacrylamide gel onto  

E-print Network

for transferring proteins out of a polyacrylamide gel onto a membrane for subsequent western blotting. With a high­ionic strength transfer buffer, protein transfer from nitrocellulose or polyvinylidene difluoride (PVDF) membranes can be achieved in 5­10 m, even with proteins as large as 300 kDa. Introduction Western blotting

Cai, Long

70

Normoxic polyacrylamide gel doped with iodine: response versus X-ray energy.  

PubMed

The basis of Synchrotron Stereotactic Radio-Therapy (SSRT) is the incorporation of high atomic number atoms (iodine, for example) into the tumour mass followed by an irradiation with a monochromatic, low energy, X-ray beam from a synchrotron source. The purpose of the present study was to determine whether polymer gel dosimetry could be used to measure the enhancement of absorbed energy induced by the iodine in the media. We have used a standard nPAG formulation, loaded with NaI and the irradiations were performed either with monochromatic X-rays at the ESRF medical beamline or with a conventional 6 MV X-ray beam from a linear accelerator at the Grenoble University Hospital. We observed sensitivity increase with iodine loaded gels irradiated at low energies, in good agreement with the theoretical iodine dose-enhancement. As expected, the response of the iodine-doped polymer gel was not increased after irradiation with mega-voltage X-rays. We demonstrate in this study that polymer gel dosimeters can be used for measuring dose-enhancement due to iodine presence in SSR treatment. PMID:18602237

Gastaldo, Jérôme; Boudou, Caroline; Lamalle, Laurent; Troprès, Irène; Corde, Stéphanie; Sollier, Albéric; Rucka, Günther; Elleaume, Hélène

2008-12-01

71

Quantification of AAV Particle Titers by Infrared Fluorescence Scanning of Coomassie-Stained Sodium Dodecyl Sulfate-Polyacrylamide Gels  

PubMed Central

Abstract Adeno-associated virus (AAV)-based vectors have gained increasing attention as gene delivery vehicles in basic and preclinical studies as well as in human gene therapy trials. Especially for the latter two—for both safety and therapeutic efficacy reasons—a detailed characterization of all relevant parameters of the vector preparation is essential. Two important parameters that are routinely used to analyze recombinant AAV vectors are (1) the titer of viral particles containing a (recombinant) viral genome and (2) the purity of the vector preparation, most commonly assessed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) followed by silver staining. An important, third parameter, the titer of total viral particles, that is, the combined titer of both genome-containing and empty viral capsids, is rarely determined. Here, we describe a simple and inexpensive method that allows the simultaneous assessment of both vector purity and the determination of the total viral particle titer. This method, which was validated by comparison with established methods to determine viral particle titers, is based on the fact that Coomassie Brilliant Blue, when bound to proteins, fluoresces in the infrared spectrum. Viral samples are separated by SDS–PAGE followed by Coomassie Brilliant Blue staining and gel analysis with an infrared laser-scanning device. In combination with a protein standard, our method allows the rapid and accurate determination of viral particle titers simultaneously with the assessment of vector purity. PMID:22816378

Kohlbrenner, Erik; Henckaerts, Els; Rapti, Kleopatra; Gordon, Ronald E.; Linden, R. Michael; Hajjar, Roger J.

2012-01-01

72

Use of Two-Dimensional Polyacrylamide Gel Electrophoresis to Identify and Classify Rhizobium Strains  

PubMed Central

Fifty-seven strains of various Rhizobium species were analyzed by two-dimensional gel electrophoresis. Since the protein pattern on such gels is a reflection of the genetic background of the tested strains, similarities in pattern allowed us to estimate the relatedness between these strains. All group II rhizobia (slow growing) were closely related and were very distinct from group I rhizobia (fast growing). Rhizobium meliloti strains formed a distinct group. The collection of R. leguminosarum and R. trifolii strains together formed another distinct group. Although there were some similarities within the R. phaseoli, sesbania rhizobia, and lotus rhizobia, the members within these seemed much more diverse than the members of the above groups. The technique also is useful to determine whether two unknown strains are identical. Images PMID:16345514

Roberts, Gary P.; Leps, Walter T.; Silver, Lin E.; Brill, Winston J.

1980-01-01

73

Revisit of imidazole-zinc reverse stain for protein polyacrylamide gel electrophoresis.  

PubMed

Imidazole-zinc reverse stain (ZN stain) is known for its high sensitivity, ease of use, and cost-effective feature. ZN stain is compatible to many experiments of which those are proteomics-related in particular. Here, we describe the ZN staining procedures and the subsequent procedures incorporated in detail, along with the improvements of setup in aspects of visualization and documentation for post-processing ZN-stained gel images. PMID:22585514

Chen, Han-Min

2012-01-01

74

Novel moving reaction boundary-induced stacking and separation of human hemoglobins in slab polyacrylamide gel electrophoresis.  

PubMed

We developed a novel polyacrylamide gel electrophoresis (PAGE) method to stack and separate human hemoglobins (Hbs) based on the concept of moving reaction boundary (MRB). This differs from the classic isotachophoresis (ITP)-based stacking PAGE in the aspect of buffer composition, including the electrode buffer (pH 8.62 Tris-Gly), sample buffer (pH 6.78 Tris-Gly), and separation buffer (pH 8.52 Tris-Gly). In the MRB-PAGE system, a transient MRB was formed between alkaline electrode buffer and acidic sample buffer, being designed to move toward the anode. Hbs carried partial positive charges in the sample buffer due to its pH below pI values of Hbs, resulting in electromigrating to the cathode. Hbs would carry negative charges quickly when migrated into the alkaline electrode buffer and be transported to the anode until meeting the sample buffer again. Thus, Hbs were stacked within a MRB until the transient MRB reached the separation buffer and then separated by zone electrophoresis with molecular sieve effect of the gel. The experimental results demonstrated that there were three clear and sharp protein zones of Hbs (HbA1c, HbA0, and HbA2) in MRB-PAGE, in contrast to only one protein zone (HbA0) in ITP-PAGE for large-volume loading (?15 ?l), indicating high stacking efficiency, separation resolution, and good sensitivity of MRB-PAGE. In addition, MRB-PAGE was performed in a conventional slab PAGE device, requiring no special device. Thus, it could be widely used in separation and analysis of diluted protein in a standard laboratory. PMID:23912834

Tang, Yun-Yun; Wang, Hou-Yu; Chen, Lu; Li, Si; Guo, Chen-Gang; Fan, Hui-Zhi; Cao, Cheng-Xi; Fan, Liu-Yin

2013-10-01

75

Studies on lectins. XXXVI. Properties of some lectins prepared by affinity chromatography on O-glycosyl polyacrylamide gels.  

PubMed

A number of lectins has been purified by affinity chromatography on O-glycosyl polyacrylamide gels. The lectins isolated (and the particular sugar ligands used in the affinity carriers) are as follows: Anguilla anguilla, serum (alpha-L-fucosyl-), Vicia cracca, seeds; Phaseolus lunatus, seeds; Glycine soja, seeds; Dolichos biflorus, seeds; Maclura pomifera, seeds; Sarothamnus scoparius, seeds; Helix pomatia, ablumin glands; Clitocybe nebularis, fruiting bodies (all N-acetyl-alpha-D-galactosaminyl-); Ricinus communis, seeds (beta-lactosyl-); Ononis spinosa, root; Fomes fomentarius, fruiting bodies; Marasmius oreades, fruiting bodies (all alpha-D-galactosyl-), Canavalia ensiformis, seeds, (i.e., concanavalin A) (alpha-D-glucosyl-). Physicochemical properties of Glycine soja, Dolichos biflorus, Phaseolus lunatus, Helix Pomatia and Ricinus communis lectins corresponded well to properties of the preparations studied earlier by other workers. For the other purified lectins the essential physiochemical data (sedimentation coefficient, molecular weight, subunit composition, electrophoretic patterns, amino acid composition, carbohydrate content, isoelectric point) were established and their precipitating, hemagglutinating and mitogenic activities determined. PMID:563738

Horejsí, V; Kocourek, J

1978-01-18

76

A Single-Sample Method for Determination of Carbohydrate and Protein Contents Glycoprotein Bands Separated by Sodium Dodecyl Sulfate– Polyacrylamide Gel Electrophoresis  

Microsoft Academic Search

A method is described for determination of carbohydrate and protein contents of glycoproteins separated by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and then electroblotted onto polyvinylidene difluoride (PVDF) membranes. Blots were stained, and appropriate pieces of PVDF membranes were excised, destained, and subjected to sequential hydrolysis with 0.2 M trifluoroacetic acid (TFA) for 1 h at 80°C, then with 2 M

Ewa Zdebska; Jerzy Ko?cielak

1999-01-01

77

Dried polyacrylamide gel absorption: a method for efficient elimination of the interferences from SDS-solubilized protein samples in mass spectrometry-based proteome analysis.  

PubMed

Sample preparation holds an important place in MS-based proteome analysis. For effective proteolysis and MS analysis, it is essential to eliminate the interferences while extracting the analytes of interest from complex mixtures. To address this, herein we describe a new dried polyacrylamide gel absorption method. In this method, the protein sample prepared using high concentration of SDS was directly and completely absorbed by vacuum-dried polyacrylamide gel, and then the interfering substances including SDS and some other salts were efficiently removed by in-gel washing steps while retaining the denatured proteins in the gel, thus offering a clean environment amenable to downstream buffer exchange, proteolytic digestion and digest recovery, etc. In combination with in-gel digestion and LC-MS/MS, the newly developed method was applied to the proteome analyses of membrane-enriched fraction and whole tissue homogenate. It was demonstrated that the method is suitable for the analysis of a complex biological sample and can be widely used for sample cleanup in shotgun proteome analyses. PMID:21064138

Zhou, Jian; Li, Jianglin; Li, Jianjun; Chen, Ping; Wang, Xianchun; Liang, Songping

2010-12-01

78

Enantiomeric separations of primary amino compounds by capillary electrochromatography with monolithic chiral stationary phases of chiral crown ether-bonded negatively charged polyacrylamide gels.  

PubMed

A novel enantiomeric separation method by capillary electrochromatography with chiral crown ether-bonded negatively charged polyacrylamide gels is presented. Two kinds of chiral crown ether derivatives, (+)-tetraallyl 18-crown-6 carboxylate and (+)-18-crown-6 tetracarboxylic acid 2-allyl ester were synthesized and allowed to covalently bind to a negatively charged polyacrylamide gel, a so-called monolithic stationary phase, respectively. The gel was placed in fused-silica tubing, the walls of which had been activated with a bifunctional reagent to make the resulting gel bind covalently to the inner surface. Enantiomeric separations of 12 primary amino compounds were achieved using these columns and mobile phases of 200 mM triethanolamine-300 mM boric acid buffers with high efficiencies of up to 135000 plates m(-1). Both the within- and between-run reproducibilities of retention time and separation factor were good. The reproducibilities of retention time and separation factor for three different columns prepared from a different batch of monomers were acceptable. The gel-filled capillaries were stable for at least 13 months with intermittent use for 3 months followed by storage at room temperature for 10 months. The result of the optical purity test of alanine-2-naphthylamide is also described. PMID:11269530

Koide, T; Ueno, K

2001-02-16

79

Characterization of Finnish Borrelia burgdorferi sensu lato isolates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and with monoclonal antibodies.  

PubMed Central

Thirty-seven Borrelia burgdorferi strains, isolated in 1992 from Ixodes ricinus in Finland, were investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and by immunoblotting and indirect immunofluorescence assay (IFA) with five to nine monoclonal antibodies (MAbs). By SDS-PAGE results and reactivities to MAbs H3TS, J 8.3, I 17.3, and D6, the 37 isolates were assigned to the species B. burgdorferi sensu stricto (n = 7), Borrelia afzelii (n = 17), or Borrelia garinii (n = 13). Twenty more isolates examined only by IFA and with part of the MAbs were distributed as follows: 9 B. burgdorferi sensu stricto and 11 other species. Among 16 of 37 isolates displaying a SDS-PAGE patterns considered typical of that of B. garinii, 3 were negative by the test with MAb D6; the rest were positive. The three MAb D6-negative isolates reacted with MAb J 8.3 but not with MAb I 17.3. It is suggested that these isolates of a previously undescribed type represent atypical B. afzelii strains deficient in the expression of OspB proteins. The misleading species designation by the SDS-PAGE result is described. The IFA results were generally consistent with those obtained by immunoblotting. The exception was for 3 of 29 isolates that were positive with MAb H5332 by immunoblotting but that were IFA negative. In the present material of 57 strains, all 16 B. burgdorferi sensu stricto isolates originated from the Aland Islands. B. afzelii and B. garinii were isolated from all three regions where ticks were collected. The distributive difference seems to offer a basis for comparative clinico-epidemiological studies of Lyme borreliosis. PMID:7559935

Tuomi, J; Rantamaki, L K; Tanskanen, R; Junttila, J

1995-01-01

80

Two-dimensional polyacrylamide gel electrophoresis of equine seminal plasma proteins and their relation with semen freezability.  

PubMed

The objective was to evaluate protein profiles of equine seminal plasma using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and to determine whether any of these proteins were related to semen freezability. Seminal plasma was collected from 10 stallions, of high and low semen freezability, housed at the State Stud of Lower Saxony, and routinely used in AI programs. Twenty-five protein spots were identified from the two-dimensional gel (12%), seven of which were present in all samples (all proteins were identified by MALDI-MS). Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has been used to generate ion images of samples in one or more mass-to-charge (m/z) values, providing the capability of mapping specific molecules to two-dimensional coordinates of the original sample. Of the 25 proteins identified, two spots had greater relative content (P < 0.05) in seminal plasma samples collected from stallions with high semen freezability: spot 5 (80-85 kDa, isoelectric point [pI] 7.54), identified as CRISP-3; and spot 45 (18.2 kDa, pI 5.0-5.2), identified as HSP-2. Conversely, protein content was greater (P < 0.05) in seminal plasma samples from stallions with low semen freezability: spot 7 (75.4 kDa, pI 6.9-7.4), identified as lactoferrin; spot 15 (26.7 kDa, pI 5.51), identified as kallikrein; spot 25 (25 kDa, pI 7.54), identified as CRISP-3; and spot 35 (13.9 kDa, pI 3.8-4.2), identified as HSP-1. In conclusion, there were differences in the seminal plasma protein profile from stallions with high and low semen freezability. Furthermore, CRISP-3 and HSP-2 were potential seminal plasma markers of high semen freezability. PMID:21601917

Jobim, M I M; Trein, C; Zirkler, H; Gregory, R M; Sieme, H; Mattos, R C

2011-09-01

81

A highly sensitive "turn-on" fluorescent sensor for the detection of human serum proteins based on the size exclusion of the polyacrylamide gel.  

PubMed

A highly sensitive "turn-on" fluorescent sensor based on the size exclusion of the polyacrylamide gel was developed for the on-gels detection of human serum proteins after PAGE. The possible mechanism of this fluorescence sensor was illustrated and validated by utilizing five kinds of colloidal silver nanoparticles with different particle size distribution and six kinds of polyacrylamide gels with different pore size. It was attributed to that silver nanoparticles (<5 nm in diameter) had been selectively absorbed into the gel and formed the small silver nanoclusters, resulting in the red fluorescence. Using this new technique for the detection of human serum proteins after PAGE, a satisfactory sensitivity was achieved and some relatively low-abundance proteins (e.g. zinc-alpha-2-glycoprotein), which are the significant proteinic markers of certain diseases can be easily detected, but not with traditional methods. Furthermore, it was also successfully applied to distinguish between serums from hepatoma patient and healthy people. As a new protein detection technique, the colloidal silver nanoparticles based "turn-on" fluorescent sensor offers a rapid, economic, low background, and sensitive way for direct detection of human serum proteins, showing available potential and significance in the development of nanobiotechnology and proteome research. PMID:24150987

Xu, Shenghao; Liu, Pingping; Lu, Xin; Zhang, Jing; Huang, Lingyun; Hua, Wenhao; He, Dacheng; Ouyang, Jin

2014-02-01

82

Fluid diversion and sweep improvement with chemical gels in oil recovery processes. [Four types of gels: resorcinol-formaldehyde; colloidal silica; Cr sup 3+ (chloride)-xanthan; and Cr sup 3+ (acetate)-polyacrylamide  

SciTech Connect

The objectives of this project were to identify the mechanisms by which gel treatments divert fluids in reservoirs and to establish where and how gel treatments are best applied. Several different types of gelants were examined, including polymer-based gelants, a monomer-based gelant, and a colloidal-silica gelant. This research was directed at gel applications in water injection wells, in production wells, and in high-pressure gas floods. The work examined how the flow properties of gels and gelling agents are influenced by permeability, lithology, and wettability. Other goals included determining the proper placement of gelants, the stability of in-place gels, and the types of gels required for the various oil recovery processes and for different scales of reservoir heterogeneity. During this three-year project, a number of theoretical analyses were performed to determine where gel treatments are expected to work best and where they are not expected to be effective. The most important, predictions from these analyses are presented. Undoubtedly, some of these predictions will be controversial. However, they do provide a starting point in establishing guidelines for the selection of field candidates for gel treatments. A logical next step is to seek field data that either confirm or contradict these predictions. The experimental work focused on four types of gels: (1) resorcinol-formaldehyde, (2) colloidal silica, (3) Cr{sup 3+}(chloride)-xanthan, and (4) Cr{sup 3+}(acetate)-polyacrylamide. All experiments were performed at 41{degrees}C.

Seright, R.S.; Martin, F.D.

1992-09-01

83

The unravelling of metabolic dysfunctions linked to metal-associated diseases by blue native  

E-print Network

-PAGE Blue native polyacrylamide gel electrophoresis ETC Electron transport chain FAD Flavin adenine dinucleotide Fe-S iron­sulfur G6PDH Glucose 6-phosphate dehydrogenase HK Hexokinase ICDH Isocitrate

Appanna, Vasu

84

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

PubMed

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

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

2003-10-01

85

Continuous monitoring of enzymatic activity within native electrophoresis gels: Application to mitochondrial oxidative phosphorylation complexes  

PubMed Central

Native gel electrophoresis allows the separation of very small amounts of protein complexes while retaining aspects of their activity. In-gel enzymatic assays are usually performed by using reaction-dependent deposition of chromophores or light scattering precipitates quantified at fixed time points after gel removal and fixation, limiting the ability to analyze enzyme reaction kinetics. Herein, we describe a custom reaction chamber with reaction media recirculation and filtering and an imaging system that permits the continuous monitoring of in-gel enzymatic activity even in the presence of turbidity. Images were continuously collected using time-lapse high resolution digital imaging, and processing routines were developed to obtain kinetic traces of the in-gel activities and analyze reaction time courses. This system also permitted the evaluation of enzymatic activity topology within the protein bands of the gel. This approach was used to analyze the reaction kinetics of two mitochondrial complexes in native gels. Complex IV kinetics showed a short initial linear phase where catalytic rates could be calculated, whereas Complex V activity revealed a significant lag phase followed by two linear phases. The utility of monitoring the entire kinetic behavior of these reactions in native gels, as well as the general application of this approach, is discussed. PMID:22975200

Covian, Raul; Chess, David; Balaban, Robert S.

2012-01-01

86

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)

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.

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

2003-07-01

87

Polyacrylamide hydrogel micropatterning.  

PubMed

This chapter describes the production of micropatterns of extracellular matrix proteins on a 2D flat polyacrylamide (PAA) gel. The technique is divided into two parts. First, micropatterns are produced on glass or directly on a photomask using deep UV. Then the micropatterns are transferred on acrylamide gel by polymerization of the gel directly on the template coverslip. This procedure is easy to perform and does not require any expensive equipment. It can be performed in no more than 2h once you get your hands on it. It combines the advantages of other existing techniques: good spatial resolution, suitable for very soft gel, no need for the use of chemical crosslinkers for attachment of the proteins to the acrylamide, no modification of the mechanical properties of the gel by the process, and suitable for multiple protein patterning. We also discuss the storage issues of such substrates and provide a brief review of other existing techniques for micropatterning on PAA. PMID:24484659

Vignaud, Timothée; Ennomani, Hajer; Théry, Manuel

2014-01-01

88

Direct detection of an antimicrobial peptide of Pediococcus acidilactici in sodium dodecyl sulfate-polyacrylamide gel electrophoresis  

Microsoft Academic Search

Summary An SDS-PAGE technique is described that allows identification of the antimicrobial activity of a peptide secreted by a strain ofPediococcus acidilactici. This peptide has an antimicrobial property against several baeteria associated with food. This technique enables detection of the specific peptide (or protein) band(s) associated with the inhibitory effect which can then be eluted from the gel for further

Arun K. Bhunia; M. C. Johnson; Bibek Ray

1987-01-01

89

Structural analysis of protein complexes with sodium alkyl sulfates by small-angle scattering and polyacrylamide gel electrophoresis.  

PubMed

Small-angle X-ray (SAXS) and neutron (SANS) scattering is used to probe the structure of protein-surfactant complexes in solution and to correlate this information with their performance in gel electrophoresis. Proteins with sizes between 6.5 to 116 kDa are denatured with sodium alkyl sulfates (SC(x)S) of variable tail lengths. Several combinations of proteins and surfactants are analyzed to measure micelle radii, the distance between micelles, the extension of the complex, the radius of gyration, and the electrophoretic mobility. The structural characterization shows that most protein-surfactant complexes can be accurately described as pearl-necklace structures with spherical micelles. However, protein complexes with short surfactants (SC(8)S) bind with micelles that deviate significantly from spherical shape. Sodium decyl (SC(10)S) and dodecyl (SC(12)S, more commonly abbreviated as SDS) sulfates result in the best protein separations in standard gel electrophoresis. Particularly, SC(10)S shows higher resolutions for complexes of low molecular weight. The systematic characterization of alkyl sulfate surfactants demonstrates that changes in the chain architecture can significantly affect electrophoretic migration so that protein-surfactant structures could be optimized for high resolution protein separations. PMID:21182321

Ospinal-Jiménez, Mónica; Pozzo, Danilo C

2011-02-01

90

On-Chip Native Gel Electrophoresis-Based Immunoassays for Tetanus Antibody and Toxin  

E-print Network

On-Chip Native Gel Electrophoresis-Based Immunoassays for Tetanus Antibody and Toxin Amy E. Herr was developed for detection of tetanus antibodies in buffer as well as diluted serum samples. After an off was 0.68 nM. A competitive immunoassay was also developed for tetanus toxin C-fragment by allowing un

Herr, Amy E.

91

Proteome analysis of glycoforms: a review of strategies for the microcharacterisation of glycoproteins separated by two-dimensional polyacrylamide gel electrophoresis.  

PubMed

Preparative two-dimensional polyacrylamide electrophoresis (2-D PAGE) is a method of separation which for the first time allows protein isoforms to be readily purified for subsequent analysis. The profile of the 2-D separation of the protein complement (proteome) of eukaryotic cells and tissues typically contains obvious 'trains' of spots which differ in pI and/or apparent molecular mass. These are usually isoforms of the same protein and result from post-translational modifications. There is growing evidence that alterations to the glycosylation and/or phosphorylation of a protein can be correlated with developmental and pathological changes; these changes can be visualised on the 2-D separation. It is not clear, however, how these modifications alter the structural properties of the protein and affect their migration in this mode of separation. Strategies need to be developed to obtain a more detailed understanding of the reason for the appearance of isoforms as discrete spots on 2-D PAGE. Standard proteins, fetuin and ovalbumin, were used to monitor the effect of the removal of glycans and phosphates on the migration of the glycoproteins in the 2-D system. The isoforms were not simply explained by the presence or absence of a single modification. To further investigate the reasons for the different migration of the isoforms it is necessary to characterise the modifications in more detail. Unlike protein analysis, until recently the available methodology for the analysis of the glycans attached to proteins has not been sensitive enough to allow analysis of single spots in gels or blots resulting from 2-D electrophoresis. In this paper we review current and future strategies for characterisation of protein modifications using single spots from 2-D gels. PMID:9150924

Packer, N H; Pawlak, A; Kett, W C; Gooley, A A; Redmond, J W; Williams, K L

1997-01-01

92

Differential Silver-Staining Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis: A Nonisotopic Method for Characterizing Gel-Separated Histone–DNA Complexes  

Microsoft Academic Search

Some nonspecific, DNA-binding proteins, like the linker histones, precipitate DNA upon binding. This is a poorly understood process that limits analysis of such nucleoprotein complexes using standard gel electrophoresis. To circumvent this problem, low concentrations of glutaraldehyde were used to crosslink the linker histones to DNA; then the partially crosslinked complexes were solubilized in SDS2and separated by SDS–PAGE. Differential detection

George John Carter; Kensal van Holde

1998-01-01

93

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

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

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

2014-10-01

94

Evidence for recombination between N- and B-tropic murine leukemia viruses: analysis of three virion proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.  

PubMed Central

We have sodium dodecyl sulfate-polyacrylamide gel electrophoresis to analyze the virion proteins of an N- and a B-tropic C-type virus derived from the BALB/c mouse and 21 putative recombinants, designated XLP-N viruses, obtained from seven crosses between these N- and B-tropic viruses. All the XLP-N viruses are N-tropic but posses the XC plaque morphology of their B-tropic virus parent. Three virion proteins, p15, p30, and gp70, of the parental viruses each differ in electrophoretic mobility. Two recombinants were found that possess a p15 that comigrates with p15 of the B virus; 19 possess a p15 that comigrates with N virus p15. Sixteen recombinants possess a gp70 that migrates like the gp70 of the B virus: four have gp70 with an electrophoretic mobility like that of the N virus gp70. All 21 recombinants possess a p30 that comigrates with p30 of their N virus parent. Given the origin and phenotype of XLP-N viruses, these results would seem to provide good evidence that these viruses are recombinants. Images PMID:197267

Schindler, J; Hynes, R; Hopkins, N

1977-01-01

95

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

PubMed Central

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

Whalen, Michael; Wilson, Thomas G.

1986-01-01

96

Two-Dimensional Polyacrylamide Gel Electrophoresis Analysis of the Acid Tolerance Response in Listeria monocytogenes LO28  

PubMed Central

Listeria monocytogenes is capable of withstanding low pH after initial exposure to sublethal acidic conditions, a phenomenon termed the acid tolerance response (B. O'Driscoll, C. G. M. Gahan, and C. Hill, Appl. Environ. Microbiol. 62:1693-1698, 1996). Treatment of L. monocytogenes LO28 with chloramphenicol during acid adaptation abrogated the protective effect, suggesting that de novo protein synthesis is required for the acid tolerance response. Analysis of protein expression during acid adaptation by two-dimensional gel electrophoresis revealed changes in the levels of 53 proteins. Significant protein differences were also evident between nonadapted L. monocytogenes LO28 and a constitutively acid-tolerant mutant, ATM56. In addition, the analysis[S_TABC] revealed differences in protein expression between cells induced with a weak acid (lactic acid) and those induced with a strong acid (HCl). Comparison of both acid-adapted LO28 and ATM56 revealed that both are capable of maintaining their internal pH (pH(infi)) at higher levels than nonadapted control cells during severe acid stress. Collectively, the data demonstrate the profound alterations in protein synthesis which take place during acid adaptation in L. monocytogenes and ultimately lead to an increased ability to survive severe stress conditions. PMID:16535645

O'Driscoll, B.; Gahan, C.; Hill, C.

1997-01-01

97

Quantification of bovine sperm separation by a swim-up method. Relationship to sperm motility, integrity of acrosomes, sperm migration in polyacrylamide gel and fertility.  

PubMed

The number of bovine spermatozoa separated in a swim-up procedure was quantified using an electronic cell counter. In an initial test of the swim-up procedure, non-frozen sperm samples with different ratios of live to dead cells were prepared and tested for the number of spermatozoa counted by the swim-up procedure. In ejaculates from six bulls, the number of spermatozoa swimming up was related to the number of live cells present (R2 = 0.97). Next, sperm quality of frozen-thawed semen immediately after thawing was measured at 37 C by swim-up sperm count, sperm motility, spermatozoa with an intact acrosome and migration in polyacrylamide gel and then compared with the fertility of the semen used for artificial insemination. Twenty-nine ejaculates of frozen-thawed semen from 11 bulls were evaluated. Correlations with fertility were highest on an ejaculate basis for motility (r = 0.41, P = 0.05) and for swim-up sperm count (r = 0.35, P = 0.06). On a bull basis, swim-up sperm count had the highest correlation with fertility (r = 0.59, P = 0.06). In a multiple regression model to predict male fertility that included all described measures of semen quality, a R2 value of 0.69 was obtained. This is the first report showing that the ability of spermatozoa to swim out of a more dense medium (whole milk-glycerol extender) into culture media is quantitatively related to in vivo fertility. PMID:3624063

Parrish, J J; Foote, R H

1987-01-01

98

Dimethylformamide interferes with Coomassie dye staining of proteins on blue native gel electrophoresis.  

PubMed

Blue native gel electrophoresis (BN-PAGE) is used extensively for characterization of mitochondrial respiratory complexes and uses the binding of Coomassie brilliant blue G-250 to visualize proteins. Oxidative modification of sulfhydryl groups of such proteins can be evaluated by labeling with iodoacetamide conjugated to biotin (BIAM) and detected with streptavidin peroxidase on Western blots following BN-PAGE. However, dissolving BIAM in dimethylformamide, a recommended solvent, reduces Coomassie blue G staining to proteins during BN-PAGE. This interference is prevented by dissolving BIAM in dimethyl sulfoxide. Precautions in the use of the dye for protein staining subsequent to BIAM labeling are discussed. PMID:24662748

Raghupathy, V; Oommen, Anna; Ramachandran, Anup

2014-06-15

99

Relative Quantitative Comparisons of the Extracellular Protein Profiles of Staphylococcus aureus UAMS-1 and Its sarA, agr, and sarA agr Regulatory Mutants Using One-Dimensional Polyacrylamide Gel Electrophoresis and Nanocapillary Liquid Chromatography Coupled with Tandem Mass Spectrometry  

Microsoft Academic Search

One-dimensional polyacrylamide gel electrophoresis followed by nanocapillary liquid chromatography cou- pled with mass spectrometry was used to analyze proteins isolated from Staphylococcus aureus UAMS-1 after 3, 6, 12, and 24 h of in vitro growth. Protein abundance was determined using a quantitative value termed normalized peptide number, and overall, proteins known to be associated with the cell wall were more

Richard C. Jones; Joanna Deck; Ricky D. Edmondson; Mark E. Hart

2008-01-01

100

Detection of glycoproteins in polyacrylamide gels and on electroblots using Pro-Q Emerald 488 dye, a fluorescent periodate Schiff-base stain.  

PubMed

Pro-Q Emerald 488 glycoprotein stain reacts with periodic acid-oxidized carbohydrate groups, generating a bright green-fluorescent signal on glycoproteins. The stain permits detection of less than 5-18 ng of glycoprotein per band, depending upon the nature and the degree of protein glycosylation, making it roughly 8-16-fold more sensitive than the standard colorimetric periodic acid-Schiff base method using acidic fuchsin dye (pararosaniline). The green-fluorescent signal from Pro-Q Emerald 488 stain may optimally be visualized using charge-coupled device/xenon arc lamp-based imaging systems or 470-488 nm laser-based gel scanners. Though glycoprotein detection may be performed on transfer membranes, direct detection in gels avoids electroblotting and the specificity of staining is better in gels. After detecting glycoproteins with Pro-Q Emerald 488 dye, total protein profiles may subsequently be detected using SYPRO Ruby protein gel stain. Using computer-assisted registration techniques, images may then be merged to generate differential display maps. PMID:12601726

Hart, Courtenay; Schulenberg, Birte; Steinberg, Thomas H; Leung, Wai-Yee; Patton, Wayne F

2003-02-01

101

Lipid, Detergent, and Coomassie Blue G-250 Affect the Migration of Small Membrane Proteins in Blue Native Gels  

PubMed Central

Blue native gel electrophoresis is a popular method for the determination of the oligomeric state of membrane proteins. Studies using this technique have reported that mitochondrial carriers are dimeric (composed of two ?32-kDa monomers) and, in some cases, can form physiologically relevant associations with other proteins. Here, we have scrutinized the behavior of the yeast mitochondrial ADP/ATP carrier AAC3 in blue native gels. We find that the apparent mass of AAC3 varies in a detergent- and lipid-dependent manner (from ?60 to ?130 kDa) that is not related to changes in the oligomeric state of the protein, but reflects differences in the associated detergent-lipid micelle and Coomassie Blue G-250 used in this technique. Higher oligomeric state species are only observed under less favorable solubilization conditions, consistent with aggregation of the protein. Calibration with an artificial covalent AAC3 dimer indicates that the mass observed for solubilized AAC3 and other mitochondrial carriers corresponds to a monomer. Size exclusion chromatography of purified AAC3 in dodecyl maltoside under blue native gel-like conditions shows that the mass of the monomer is ?120 kDa, but appears smaller on gels (?60 kDa) due to the unusually high amount of bound negatively charged dye, which increases the electrophoretic mobility of the protein-detergent-dye micelle complex. Our results show that bound lipid, detergent, and Coomassie stain alter the behavior of mitochondrial carriers on gels, which is likely to be true for other small membrane proteins where the associated lipid-detergent micelle is large when compared with the mass of the protein. PMID:23744064

Crichton, Paul G.; Harding, Marilyn; Ruprecht, Jonathan J.; Lee, Yang; Kunji, Edmund R. S.

2013-01-01

102

Speciation analysis of inorganic arsenic in river water by Amberlite IRA 910 resin immobilized in a polyacrylamide gel as a selective binding agent for As(V) in diffusive gradient thin film technique.  

PubMed

In this study, a method is proposed for the selective retention of As(V) using diffusive gradient in thin film (DGT) samplers containing a strongly basic anion exchange resin (Amberlite IRA 910) supported on a polyacrylamide gel. In addition, the total arsenic content is determined by ferrihydrite gel discs. Subsequently, the concentration of As(III) was obtained by determining the difference between the total As and As(V). DGT experiments showed linear accumulation of As(V) (up to 280 ng) until a deployment time of 8 h deployment (R(2) > 0.99). The retention of As(V) was appropriate (97.9-112.3%) between pH 5 and 9. For a solution with an ionic strength ranging from 0.001 to 0.05 mol L(-1), the As(V) uptake ranged from 90-120%. The proposed method was applied for the speciation of arsenic in river water. For the analysis of spiked samples collected at the Furnas stream, the recoveries of total arsenic content ranged between 103.9% and 118.8%. However, the recoveries of As(III) and As(V) were 43.3-75.2% and 147.3-153.4%, respectively. These differences were probably because of the oxidation of As(III) to As(V) during deployments. For spiked samples collected at the Ribeirão Claro, the recoveries of dissolved As(III), As(V) and As(T) were 103.1%, 108.0% and 106.3%, respectively. Thus, the DGT technique with Amberlite IRA 910 resin as the binding phase can be employed for the in situ redox speciation of inorganic arsenic. PMID:25010156

Rolisola, Ana M C M; Suárez, Carlos A; Menegário, Amauri A; Gastmans, Didier; Kiang, Chang H; Colaço, Camila D; Garcez, Daniel L; Santelli, Ricardo E

2014-09-01

103

Depletion of hemoglobin and carbonic anhydrase from erythrocyte cytosolic samples by preparative clear native electrophoresis  

Microsoft Academic Search

Proteomic analysis of red cells is compromised by the presence of high-abundance proteins (hemoglobin and carbonic anhydrase-1), which completely obscure low-abundance species. The depletion method presented here involves performing native gel electrophoresis in a polyacrylamide gel tube using a modified electroelution cell. The electrophoretic run is interrupted intermittently to allow the recovery of at least three different liquid fractions, which

Gian Maria D'Amici; Sara Rinalducci; Lello Zolla

2011-01-01

104

Preparation of DNA-crosslinked Polyacrylamide Hydrogels.  

PubMed

Mechanobiology is an emerging scientific area that addresses the critical role of physical cues in directing cell morphology and function. For example, the effect of tissue elasticity on cell function is a major area of mechanobiology research because tissue stiffness modulates with disease, development, and injury. Static tissue-mimicking materials, or materials that cannot alter stiffness once cells are plated, are predominately used to investigate the effects of tissue stiffness on cell functions. While information gathered from static studies is valuable, these studies are not indicative of the dynamic nature of the cellular microenvironment in vivo. To better address the effects of dynamic stiffness on cell function, we developed a DNA-crosslinked polyacrylamide hydrogel system (DNA gels). Unlike other dynamic substrates, DNA gels have the ability to decrease or increase in stiffness after fabrication without stimuli. DNA gels consist of DNA crosslinks that are polymerized into a polyacrylamide backbone. Adding and removing crosslinks via delivery of single-stranded DNA allows temporal, spatial, and reversible control of gel elasticity. We have shown in previous reports that dynamic modulation of DNA gel elasticity influences fibroblast and neuron behavior. In this report and video, we provide a schematic that describes the DNA gel crosslinking mechanisms and step-by-step instructions on the preparation DNA gels. PMID:25226067

Previtera, Michelle L; Langrana, Noshir A

2014-01-01

105

Photopatterned polyacrylamide gels enable efficient microfluidic assays  

E-print Network

GFP filter cube) were summed with image sequences taken oncubes and independent realizations of separations in each color signal. To produce two-color CCD images,cube) from back-to-back injections of the same multi-component samples. Image

Hou, Chenlu

2011-01-01

106

Hybrid Gel Composed of Native Heart Matrix and Collagen Induces Cardiac Differentiation of Human Embryonic Stem  

E-print Network

the ability of native heart extracellular matrix (ECM) to direct cardiac differentiation of human embryonic, a series of hydrogels was prepared from decellularized ECM from porcine hearts by mixing ECM and collagen markers. Hydrogel with high ECM content (75% ECM, 25% collagen, no supple- mental soluble factors

Linhardt, Robert J.

107

Physical properties of natively textured yttrium doped zinc oxide films by sol-gel  

Microsoft Academic Search

Sol-gel derived yttrium doped ZnO films of various thicknesses have been deposited by the dip coating technique. The investigations of microstructural, electrical and optical properties of post heat-treated films in air as a function of thickness have been made. It is found that high quality films are obtained at an annealing temperature of 550 ?C. The (002) preferential growth of

R. Kaur; A. V. Singh; R. M. Mehra

2005-01-01

108

Electrically controlled polymeric gel actuators  

Microsoft Academic Search

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

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

1993-01-01

109

Electrically controlled polymeric gel actuators  

Microsoft Academic Search

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

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

1993-01-01

110

Performance of Competitive and Indirect Enzyme-Linked Immunosorbent Assays, Gel Immunoprecipitation with Native Hapten Polysaccharide, and Standard Serological Tests in Diagnosis of Sheep Brucellosis  

Microsoft Academic Search

Competitive and standard enzyme-linked immunosorbent assays (ELISAs), rose bengal (RB), complement fixation, and agar gel immunoprecipitation with native hapten (AGID-NH) were compared by using sera from Brucella-free, Brucella melitensis-infected, and B. melitensis Rev1-vaccinated sheep. The most sensitive tests were indirect ELISA and RB, and the most specific tests were AGID-NH and competitive ELISA. We show that RB followed by AGID-NH

C. M. MARIN; E. MORENO; I. MORIYON; R. DIAZ; J. M. BLASCO

111

Lipid, detergent, and Coomassie Blue G-250 affect the migration of small membrane proteins in blue native gels: mitochondrial carriers migrate as monomers not dimers.  

PubMed

Blue native gel electrophoresis is a popular method for the determination of the oligomeric state of membrane proteins. Studies using this technique have reported that mitochondrial carriers are dimeric (composed of two ?32-kDa monomers) and, in some cases, can form physiologically relevant associations with other proteins. Here, we have scrutinized the behavior of the yeast mitochondrial ADP/ATP carrier AAC3 in blue native gels. We find that the apparent mass of AAC3 varies in a detergent- and lipid-dependent manner (from ?60 to ?130 kDa) that is not related to changes in the oligomeric state of the protein, but reflects differences in the associated detergent-lipid micelle and Coomassie Blue G-250 used in this technique. Higher oligomeric state species are only observed under less favorable solubilization conditions, consistent with aggregation of the protein. Calibration with an artificial covalent AAC3 dimer indicates that the mass observed for solubilized AAC3 and other mitochondrial carriers corresponds to a monomer. Size exclusion chromatography of purified AAC3 in dodecyl maltoside under blue native gel-like conditions shows that the mass of the monomer is ?120 kDa, but appears smaller on gels (?60 kDa) due to the unusually high amount of bound negatively charged dye, which increases the electrophoretic mobility of the protein-detergent-dye micelle complex. Our results show that bound lipid, detergent, and Coomassie stain alter the behavior of mitochondrial carriers on gels, which is likely to be true for other small membrane proteins where the associated lipid-detergent micelle is large when compared with the mass of the protein. PMID:23744064

Crichton, Paul G; Harding, Marilyn; Ruprecht, Jonathan J; Lee, Yang; Kunji, Edmund R S

2013-07-26

112

Two-Component Supramolecular Gels Derived from Amphiphilic Shape-Persistent Cyclo[6]aramides for Specific Recognition of Native Arginine.  

PubMed

A unique supramolecular two-component gelation system was constructed from amphiphilic shape-persistent cyclo[6]aramides and diethylammonium chloride (or triethylammonium chloride). This system has the ability to discriminate native arginine from 19 other amino acids in a specific fashion. Cyclo[6]aramides show preferential binding for the guanidinium residue over ammonium groups. This specificity was confirmed by both experimental results and theoretical simulations. These results demonstrated a new modular displacement strategy, exploring the use of species-binding hydrogen-bonded macrocyclic foldamers for the construction of two-component gelation systems for selective recognition of native amino acids by competitive host-guest interactions. This strategy may be amenable to developing a variety of functional two-component gelators for specific recognition of various targeted organic molecular species. PMID:25213644

He, Youzhou; Xu, Min; Gao, Rongzhao; Li, Xiaowei; Li, Fengxue; Wu, Xuedan; Xu, Dingguo; Zeng, Huaqiang; Yuan, Lihua

2014-10-27

113

An experimental study of conformance treatments using crosslinked polyacrylamide polymer  

SciTech Connect

The objective of this study was to identify the correlation among the gel strength, redox concentration, the permeability of the porous medium before treatment and the extent of permeability reduction after treatment. The gelling solution system employed consisted of CYANAGLE 100 partially hydrolyzed polyacrylamide polymer, sodium dichromate as the source of hexavalent chromium cations, and a reducing agent. Gelation and rheological studies were first performed to identify gelling solutions having proper gelation time and gel strength combination for subsequent in-situ gelation studies. The results indicate that the gelation time and gel strength combination of a gelling solution can be controlled by carefully selecting the type and concentration of the redox system employed. In-situ gelation studies were conducted using gelling solutions with different gel strengths and sandpacks having different initial permeabilities. The results indicate that while the initial permeability of the sandpacks remains within the same range, the degree of permeability reduction after treatment increased with increasing gel strength. The results also reveal that for weak gels having gel strength less than 200 dyne/cm{sup 2}, the extent of permeability reduction remains low and increases slowly with increasing gel strength. For strong gels having gel strength greater than 1000 dyne/cm{sup 2}, complete plugging of the sandpacks was observed. The results of the yield stress measurements disclose that the complete plugging was caused by the pressure gradients needed to start the flow of the gels being greater than the maximum output pressure of the pump. The degree of permeability reduction after treatment was found to increase with increasing polymer and chromium retention.

Liang, J.T.

1988-01-01

114

Nanotube-grafted polyacrylamide hydrogels for electrophoretic protein separation.  

PubMed

Multiwalled carbon nanotube-modified polyacrylamide gels have been employed for the electrophoretic separation of proteins. Two approaches are compared in this investigation, one using nanotubes only as fillers inside the gel matrix and the other using nanotubes as catalyst for polymerization of acrylamide. In both the cases, polymerization of acryl-amide/bisacrylamide has been carried out in situ in the presence of nanotubes dispersed in the gel buffer containing monomer and cross-linker. In the former case, initiator and catalyst have been added after ultrasonication of nanotubes in the gel buffer mixture where the nanotubes play the role of filler. On the other hand, the second approach precludes use of catalyst and involves addition of initiator alone during ultrasonication of nanotubes in the gel buffer containing monomer and cross-linker, which leads to the formation of nanotube-grafted gel after 25 min. When nanotubes are used as a catalyst instead of N,N,N',N'-tetramethylethylenediamine, pore size distribution of the gel matrix and linearity of molecular weight calibration plots are found to be improved. In addition, other issues associated with the use of an external catalyst like handling the moisture-sensitive and corrosive reagent and associated irreproducibility are addressed in this approach. PMID:22589105

Gunavadhi, Murugappan; Maria, Lourdusamy Arul Antony; Chamundeswari, Vidya N; Parthasarathy, Meera

2012-04-01

115

Spring-loaded polymeric gel actuators  

DOEpatents

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.

Shahinpoor, Mohsen (Albuquerque, NM)

1995-01-01

116

Recent Applications of Polyacrylamide as Biomaterials  

Microsoft Academic Search

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

Tsung-Hua Yang

2008-01-01

117

Long-term effects of polyacrylamide hydrogel on human breast tissue.  

PubMed

Polyacrylamide hydrogel is an atoxic, stable, nonresorbable sterile watery gel consisting of approximately 2.5% cross-linked polyacrylamide and nonpyrogenic water. Polyacrylamide hydrogel is widely used in ophthalmic operations, drug treatment, food packaging products, and water purification. In the former Soviet Union, polyacrylamide hydrogel has been used in plastic and aesthetic surgery for more than 10 years, and Kiev City Hospital treats approximately 300 women a year for breast augmentation using the polyacrylamide hydrogel Interfall (Contura SA, Montreux, Switzerland). Capsule shrinkage following these injections has never been observed. The authors examined breast tissue samples from a total of 27 women who had polyacrylamide hydrogel injected at Kiev City Hospital up to 8 years and 10 months earlier. Age at operation, duration of polyacrylamide hydrogel implantation, history of possible side effects to the gel injection, other intercurrent diseases, the reason for present open breast operation, and breast palpation findings before operation were in each case compared with the histological findings on samples taken from breast tissue bordering the gel. The gel presented itself as a dark violet, homogenous mass with a rounded or ragged outline in large or medium-size deposits and as elongated strands, which mimicked the extracellular matrix, in small deposits. Histological findings of the breast tissue bordering the gel showed three different patterns: large collections of gel gave rise to a thick, soft-looking cellular membrane of macrophages and foreign-body giant cells; medium-size deposits were surrounded by just a thin layer of macrophages; and small deposits were not associated with any reaction in the surrounding tissue. Projections of the cellular soft membrane, known as granulomas, were seen in six patients. The granulomas were composed of macrophages, foreign-body giant cells, lymphocytes, and blood cells. A thin layer of fibrous connective tissue was occasionally present around the foreign-body membrane, but the thick fibrous capsule, which has been described in connection with silicone implants, was completely absent. The gel changes could be correlated to neither time since gel injection nor a history of recent injury or inflammation. It is concluded that the polyacrylamide hydrogel Interfall, which has been used in the former Soviet Union, is stable over time, nondegradable, confined to the breast, and diffusion and migration resistant. When the hydrogel is injected in medium-size or large quantities a cellular foreign-body reaction occurs, but in small amounts it is capable of splitting up individual connective tissue fibers and fat cells, substituting for the extracellular connective tissue matrix without eliciting any foreign-body reaction. As far as these data are concerned, polyacrylamide hydrogel is well tolerated by the breast and does not give rise to severe fibrosis, pain, or capsule shrinkage. However, to determine safety with more certainty, a larger sample size would be necessary. PMID:12711948

Christensen, Lise H; Breiting, Vibeke B; Aasted, Annet; Jørgensen, Anna; Kebuladze, Ivan

2003-05-01

118

Templated native silk smectic gels  

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

119

Electrically controlled polymeric gel actuators  

DOEpatents

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.

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

1993-10-05

120

Electrically controlled polymeric gel actuators  

DOEpatents

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.

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

1993-01-01

121

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

Microsoft Academic Search

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

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

1989-01-01

122

Stability of gels formed following coagulation of Limulus amebocyte lysate: lack of covalent crosslinking of coagulin.  

PubMed

Incubation of lysates prepared from amebocytes of the horseshoe crab (Limulus polyphemus) with bacterial endotoxin results in coagulation and formation of a solid gel. Although Limulus gels remained solid indefinitely, if undisturbed, they were easily disrupted by mechanical agitation. Chemical solubility studies of gelled lysates demonstrated rapid solubilization of gels in monochloroacetic acid, a property of clots that have not been covalently stabilized; but in contrast demonstrated resistance to solubilization by urea, a property of stabilized clots. Analysis of solubilized proteins by polyacrylamide gel electrophoresis in SDS demonstrated coagulin, the designation for the activated form of coagulogen (the clottable protein) that forms a gel, only in samples derived from clotted lysate that had been previously incubated with monochloroacetic acid, but not in samples following incubation with urea, confirming the results of the chemical solubility studies. Enzymatic assays for transpeptidase (Factor XIII-like) activity in either native or gelled Limulus lysates were negative. Furthermore, analysis for covalently crosslinked peptides in gelled coagulin confirmed the absence of intermolecular gamma-glutamyl-epsilon-lysyl bonds. Therefore, the stable gels formed following coagulation of Limulus lysate by bacterial endotoxin are not covalently crosslinked. PMID:2781519

Roth, R I; Chen, J C; Levin, J

1989-07-01

123

Polyacrylamide Transport in Water Delivery Canals  

Microsoft Academic Search

Linear, anionic polyacrylamide (PAM) is being considered in the western United States as a technology to reduce seepage in unlined water delivery canals. A broad laboratory and field testing program has been undertaken to understand the benefits and potential environmental impacts of PAM use. The ability to predict the fate and transport of PAM in water delivery canals could prove

L. Chen; J. Zhu; M. Young

2007-01-01

124

21 CFR 172.255 - Polyacrylamide.  

...FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.255 Polyacrylamide. ...than 0.2 percent of acrylamide monomer may be safely used as a film former in the imprinting of soft-shell gelatin capsules...

2014-04-01

125

Pouring and running a protein gel by reusing commercial cassettes.  

PubMed

The evaluation of proteins using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis is a common technique used by biochemistry and molecular biology researchers. For laboratories that perform daily analyses of proteins, the cost of commercially available polyacrylamide gels (~$10/gel) can be considerable over time. To mitigate this cost, some researchers prepare their own polyacrylamide gels. Traditional methods of pouring these gels typically utilize specialized equipment and glass gel plates that can be expensive and preclude pouring many gels and storing them for future use. Furthermore, handling of glass plates during cleaning or gel pouring can result in accidental breakage creating a safety hazard, which may preclude their use in undergraduate laboratory classes. Our protocol demonstrates how to pour multiple protein gels simultaneously by recycling Invitrogen Nupage Novex minigel cassettes, and inexpensive materials purchased at a home improvement store. This economical and streamlined method includes a way to store the gels at 4°C for a few weeks. By re-using the plastic gel cassettes from commercially available gels, labs that run frequent protein gels can save significant costs and help the environment. In addition, plastic gel cassettes are extremely resistant to breakage, which makes them ideal for undergraduate laboratory classrooms. PMID:22349047

Hwang, Alexander C; Grey, Paris H; Cuddy, Katrina; Oppenheimer, David G

2012-01-01

126

Quantification of viscoelastic effects of polyacrylamide solutions  

SciTech Connect

Beyond a critical rate of flow in cores the viscoelasticity of polyacrylamide solutions is reflected by shear thickening behaviour. Practical information is provided on the critical flow rate and magnitude of shear thickening and their dependency on core permeability, temperature, molecular weight and concentration of commercial polymers. To describe the onset of shear thickening, critical Deborah numbers were calculated using fluid relaxation times obtained by oscillation rheometry. Using three core-flow parameters, viz. the critical flow rate and two powerlaw exponents, the viscoelastic effects are quantified.

Heemskerk, J.; Holtslag, R.J.; Janssen-van Rosmalen, R.; Teeuw, D.

1984-04-01

127

Hybrid Gel Composed of Native Heart Matrix and Collagen Induces Cardiac Differentiation of Human Embryonic Stem Cells without Supplemental Growth Factors  

Microsoft Academic Search

Our goal was to assess the ability of native heart extracellular matrix (ECM) to direct cardiac differentiation of human embryonic\\u000a stem cells (hESCs) in vitro. In order to probe the effects of cardiac matrix on hESC differentiation, a series of hydrogels\\u000a was prepared from decellularized ECM from porcine hearts by mixing ECM and collagen type I at varying ratios. Maturation

Yi Duan; Zen Liu; John O’Neill; Leo Q. Wan; Donald O. Freytes; Gordana Vunjak-Novakovic

128

Performance and Biocompatibility of Extremely Tough Alginate/Polyacrylamide Hydrogels  

PubMed Central

Although hydrogels now see widespread use in a host of applications, low fracture toughness and brittleness have limited their more broad use. As a recently described interpenetrating network (IPN) of alginate and polyacrylamide demonstrated a fracture toughness of ?9000 J/m2, we sought to explore the biocompatibility and maintenance of mechanical properties of these hydrogels in cell culture and in vivo conditions. These hydrogels can sustain a compressive strain of over 90% with minimal loss of Young's Modulus as well as minimal swelling for up to 50 days of soaking in culture conditions. Mouse mesenchymal stem cells exposed to the IPN gel-conditioned media maintain high viability, and although cells exposed to conditioned media demonstrate slight reductions in proliferation and metabolic activity (WST assay), these effects are abrogated in a dose-dependent manner. Implantation of these IPN hydrogels into subcutaneous tissue of rats for 8 weeks led to mild fibrotic encapsulation and minimal inflammatory response. These results suggest the further exploration of extremely tough alginate/PAAM IPN hydrogels as biomaterials. PMID:23896005

Darnell, Max; Sun, Jeong-Yun; Mehta, Manav; Johnson, Chris; Arany, Praveen; Suo, Zhigang

2013-01-01

129

New gel phantoms simulating optical properties of biological tissue  

E-print Network

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...

Lee, Mija

2012-06-07

130

Experimental study of attenuation properties of normoxic polymer gel dosimeters  

Microsoft Academic Search

The change in linear attenuation coefficient with absorbed dose has been investigated for aqueous polyacrylamide, gelatine and tetrakis (PAGAT) and aqueous methacrylic acid, gelatine and tetrakis (MAGAT) normoxic polymer gel dosimeters using tetrakis (hydroxy methyl) phosphonium chloride as the antioxidant. The measured linear attenuation coefficient increased linearly with absorbed dose up to 15 Gy for PAGAT gels and 10 Gy

S Brindha; A J Venning; B Hill; C Baldock

2004-01-01

131

Pore-Level Examination of Gel Destruction During Oil Flow  

E-print Network

Pore-Level Examination of Gel Destruction During Oil Flow R.S. Seright, SPE, New Mexico Petroleum-scale X-ray computed microtomography (XMT) images were obtained at a variety of oil (hexadecane(III)-acetate-hydrolyzed polyacrylamide (HPAM) gel]. For each pore in our image volume, we followed oil and water saturations

New York at Stoney Brook, State University of

132

Transport of proteins through gel-filled porous membranes  

Microsoft Academic Search

Membranes with a mean pore diameter of 0.5 ?m were filled with neutral polyacrylamide (PA) gels at fixed crosslink density. The gel was synthesized in the membranes by impregnating the pores with a solution of monomer and crosslinker and then initiating polymerization by ultraviolet radiation. The rate of diffusion and convection (ultrafiltration) of two proteins, ribonuclease A (RNAse) and bovine

Vivek Kapur; John Charkoudian; John L. Anderson

1997-01-01

133

Performance of 18 polymers in aluminum citrate colloidal dispersion gels  

SciTech Connect

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.

Smith, J.E.

1995-11-01

134

On the limiting pore size of hydrophilic gels for electrophoresis and isoelectric focusing.  

PubMed

The maximum pore diameter that can be obtained in hydrophilic gels, either highly diluted agarose (0.16%C) or highly cross-linked polyacrylamide (45%CBis or 60%C DHEBA) is around 500 nm. An empirical equation has been derived linking the mean pore diameter (mean p) to gel concentration (C) in dilute agarose gels: mean p = 140.7 x C(-0.7). It is suggested that other equations hold for concentrated gels and for highly cross-linked polyacrylamides, since the matrix structure is different. Most of the cross linkers for polymerizing polyacrylamide gels have been tabulated and their properties studied. A new gel matrix is described: a highly cross-linked N,N'-(1,2-dihydroxyethylene)bisacrylamide gel, which is hydrophilic, highly porous and can be conveniently used for electrophoresis in horizontal, ultrathin layers cast on silanized glass surfaces. PMID:7252045

Righetti, P G; Brost, B C; Snyder, R S

1981-06-01

135

Selective adsorption of hydrocarbon-oxidizing Rhodococcus cells in a column with hydrophobized poly(acrylamide) cryogel  

Microsoft Academic Search

A method for selective adsorption of Rhodococcus cells in the column with hydrophobized poly(acrylamide) cryogel (cryoPAAG) was developed that allowed rhodococci separation from mixed bacterial populations and their effective concentration within a sponge-like gel matrix. Hydrophobization of cryoPAAG using the n-dodecane graft (C12) was performed to enhance the adhesion of Rhodococcus cells to the cryogel; this was suggested by our

Maria S. Kuyukina; Ekaterina V. Rubtsova; Irena B. Ivshina; Roman V. Ivanov; Vladimir I. Lozinsky

2009-01-01

136

Improved polyacrylamide treatments for water control in producing wells  

SciTech Connect

This paper reports on two polyacrylamide processes for water control in producing wells which improve the efficiency of conventional polyacrylamide treatment without inducing any risk of well plugging by crosslinkers. Treatment of a gas-storage well strongly decreased water production without any adverse effect on gas injection or production for at least 3 years.

Zaltoun, A.; Kohler, N. (Inst. Francais du Petrole (FR)); Guerrini, Y. (Gaz de France (FR))

1991-07-01

137

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

E-print Network

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...

Shriwal, Prashant

2012-07-16

138

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

Code of Federal Regulations, 2013 CFR

...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...

2013-04-01

139

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

...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...

2014-04-01

140

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

Code of Federal Regulations, 2012 CFR

...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...

2012-04-01

141

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

Code of Federal Regulations, 2011 CFR

...Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive. 872.3420 Section...Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive. (a) Identification...carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive is a device...

2011-04-01

142

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

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Polyacrylamide polymer (modified cationic) denture adhesive...Devices § 872.3480 Polyacrylamide polymer (modified cationic) denture adhesive. (a) Identification. A polyacrylamide polymer (modified cationic) denture...

2011-04-01

143

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

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Polyacrylamide polymer (modified cationic) denture adhesive...Devices § 872.3480 Polyacrylamide polymer (modified cationic) denture adhesive. (a) Identification. A polyacrylamide polymer (modified cationic) denture...

2010-04-01

144

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

Code of Federal Regulations, 2010 CFR

...Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive. 872.3420 Section...Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive. (a) Identification...carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive is a device...

2010-04-01

145

Improving immobilized biocatalysts by gel phase polymerization  

SciTech Connect

A new method is presented for the treatment of gel-type supports, used for immobilizing microbial cells and enzymes, to obtain high mechanical strength. It is particularly useful for ethanol fermentation over gel beads containing immobilized viable cells, where the beads can be ruptured by gas production and the growth of cells within the gels. This method consists of treating agar or carrageenan gel with polyacrylamide to form a rigid support which retains the high catalytic activity characteristic of the untreated biocatalysts. The size and shape of the biocatalyst is unaffected by this treatment. The method involves the diffusion of acrylamide, N,N'-methylenebisacrylamide and BETA-dimethylaminopropionitrile (or N,N,N',N'-tetramethylethylenediamine) into the preformed biocatalyst beads followed by the addition of an initiator to cause polymerization within the beads. Treated gels have been used for the continuous fermentation of glucose to ethanol in a packed column for over two months.

Kuu, W.Y.; Polack, J.A.

1983-08-01

146

Difference gel electrophoresis: a single gel method for detecting changes in protein extracts.  

PubMed

We describe a modification of two-dimensional (2-D) polyacrylamide gel electrophoresis that requires only a single gel to reproducibly detect differences between two protein samples. This was accomplished by fluorescently tagging the two samples with two different dyes, running them on the same 2-D gel, post-run fluorescence imaging of the gel into two images, and superimposing the images. The amine reactive dyes were designed to insure that proteins common to both samples have the same relative mobility regardless of the dye used to tag them. Thus, this technique, called difference gel electrophoresis (DIGE), circumvents the need to compare several 2-D gels. DIGE is reproducible, sensitive, and can detect an exogenous difference between two Drosophila embryo extracts at nanogram levels. Moreover, an inducible protein from E. coli was detected after 15 min of induction and identified using DIGE preparatively. PMID:9420172

Unlü, M; Morgan, M E; Minden, J S

1997-10-01

147

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

Microsoft Academic Search

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

S. Sivapalan

2005-01-01

148

Immobilized electric eel acetylcholinesterase. I. Kinetics of acetylcholinesterase trapped in polyacrylamide membranes.  

PubMed

Techniques are described for the trapping of electric eel acetylcholinesterase in polyacrylamide gel. The activity of the trapped enzyme was substantially reduced, the effect being due to inhibition by acrylamide, but the emzyme immobilized in polyacrylamide was considerable more stable than that in free solutionma kinetic study was made of the hydrolysis of acetylthiocholine, covering a range of membrane thicknesses, enzyme concentrations, substrate concentrations and temperatures. The results were interpreted with reference to the theoretical treatment of Sundaram, Tweedale and Laidler, and of Kobayaski and Laidler, and provided support for those treatments; Clear evidence was obtained for diffusion control with the thicker membranes. An activation energy was obtained for the diffusion of the substrate within the membrane, by combining the temperature results for thick and thin membranes at low substrate concentrations. The results lead to the conclusion that the in vivo kinetics of acetylcholinesterase are largely diffusion-free in muscle filaments, but are substantially diffusion-controlled in fibrils and fibers. PMID:1168074

Ngo, T T; Laidler, K J

1975-02-19

149

Electric-field-enhanced transport in polyacrylamide hydrogel nano-composites  

E-print Network

Electroosmotic pumping through uncharged hydrogels can be achieved by embedding the polymer network with charged colloidal inclusions. Matos and co-workers (2006) recently used the concept to enhance the diffusion-limited flux of uncharged molecules across polyacrylamide hydrogel membraness for the purpose of improving the performance of biosensors. This paper seeks to link their reported macroscale diagnostics to physicochemical characteristics of the composite microstructure. A mathematical model for the bulk electroosmotically enhanced tracer flux is proposed, which is combined with the electrokinetic model to ascertain the electroosmotic pumping velocity from measured flux enhancements. Because the experiments are performed with a known current density, but unknown bulk conductivity and electric field strength, theoretical estimates of the bulk electrical conductivity are adopted. These account for nano-particle polarization, added counterions, and non-specific adsorption. Theoretical predictions of the flux enhancement, achieved without any fitting parameters, are within a factor of two of the experiments. Alternatively, if the Brinkman screening length of the polymer skeleton is treated as a fitting parameter, then the best-fit values are bounded by the range 0.9-1.6 nm, depending on the inclusion size and volume fraction. Independent pressure-driven flow experiments reported in the literature for polyacrylamide gels without inclusions suggest 0.4 or 0.8 nm. The comparison can be improved by allowing for hindered ion migration, while uncertainties regarding the inclusion surface charge are demonstrated to have a negligible influence on the electroosmotic flow.

Reghan J. Hill

2007-07-17

150

Gel Electrophoresis  

NSDL National Science Digital Library

This interactive activity from the Dolan DNA Learning Center illustrates the process of gel electrophoresis, in which DNA fragments are separated by size as they migrate at different rates through a gel matrix.

Foundation, Wgbh E.

2007-04-19

151

Permeability-dependent propagation of polyacrylamides under near-wellbore flow conditions  

SciTech Connect

A new type of polyacrylamide flow-induced retention has been observed in core experiments simulating near-wellbore flow conditions. The retention is due to the bridging of pore throats by adsorbed macromolecules previously stretched under elongational flow. It occurs in low-to-medium permeability granular packs (up to k = 1,000 mD in the test conditions) and leads to progressive but severe plugging. The present paper shows that polymer placement in the reservoir surrounding the wellbore can be very different from what is predicted from stable values of polymer mobility. In heterogeneous reservoirs, polymer penetration in low-permeability layers is expected to be strongly reduced, thus allowing a deeper penetration into higher permeability zones. The polymer can thus improve reservoir conformance around the wellbore when injected directly through the entire opened interval. Near-wellbore polymer or gel treatments may thus not require zone isolation to be efficient.

Zitha, P.; Chauveteau, G.; Zaitoun, A. [Inst. Francais du Petrole, Rueil-Malmaison (France)

1995-11-01

152

Collective diffusion of gels in a theta solvent (*) A.-M. Hecht and E. Geissler  

E-print Network

gels de polyacrylamide dans la condition thêta, par l'inter- médiaire d'une membrane semi309 Collective diffusion of gels in a theta solvent (*) A.-M. Hecht and E. Geissler Laboratoire de-perméable, pour produire leur dégonflement L'analyse du profil du gradient de concentration permet la mesure en

Boyer, Edmond

153

DYNAMIC LIGHT SCATTERING FROM GELS IN A POOR SOLVENT E. GEISSLER  

E-print Network

dependent; in particular the solvent viscosity displays a free volume behaviour. LE JOURNAL DE PHYSIQUE TOME955 DYNAMIC LIGHT SCATTERING FROM GELS IN A POOR SOLVENT E. GEISSLER Laboratoire de Spectroscopie and the longitudinal elastic modulus Egel of polyacrylamide gels in the poor solvent region using a water : methanol (3

Paris-Sud XI, Université de

154

Silver Staining of 2D Electrophoresis Gels Ccile Lelong, Mireille Chevallet, Sylvie Luche, Thierry Rabilloud  

E-print Network

1 Silver Staining of 2D Electrophoresis Gels Cécile Lelong, Mireille Chevallet, Sylvie Luche Cedex 9, France 1. Introduction Silver staining of polyacrylamide gels was introduced in 1979 by Switzer staining with Coomassie Blue. However, the first silver staining protocols were not trouble-free. High

Paris-Sud XI, Université de

155

Native Americans  

NSDL National Science Digital Library

Native Americans are made up of many fascinating groups of people with multiple cultures. We will explore the main cultural areas of these groups. We will describe and compare some of these groups of people such as Eastern Woodlands, Plains, Great Basin, Southwestern, Arctic, Northwest, Incan, Aztec, and Mayan. We will also identify how these people maintain their cultural traditions today. We will explore each of this interesting cultures and take notes as we explore with individualized graphic organizers. Learning about Native Americans Woodland Tribes Great Plains Tribes Great Basin Native Americans Northwest Southwest Aztec, Mayans Inca BRAINTEASER The Inca Trail and Machu Picchu Glossary Links ...

Keller, Mrs.

2009-06-12

156

Native Networks  

NSDL National Science Digital Library

Over the past few years, Native Americans have made significant contributions in a host of different media, including television, radio, and film. Involved in all aspects of this type of artistic and cultural expression, many Native Americans have also looked for a way to disseminate their substantial efforts in this arena. Fortunately, there is the Native Networks website (first launched in 2001), designed to provide information about such creations. The website was created by the Film and Video Center of the National Museum of the American Indian, and contains information about upcoming Native American film festivals and âÂÂclose-upâ profiles of people actively working in the field. Some of these features include material on the indigenous video makers in Mexico and an in-depth look at the film âÂÂHouse Made of DawnâÂÂ, which deals with a young Pueblo man in crisis. The site is available in both Spanish and English versions. [KMG

157

Study on the Complex of Soluble Proteins in the Cells of Clostridium Perfringens by Electrophoresis in Polyacrylanide Gel (O Komplekse Rastvorimykh Belkov, Soderzhashchikhsya V Kletke Clostridium Pereringens).  

National Technical Information Service (NTIS)

The method of electrophoresis in polyacrylamide gel is suitable for separating soluble acid cell proteins. The proteins are separated into a great many sharply demarcated zones and the resultant 'protein spectra' are analyzed. As a rule, the strains of C....

S. A. Nikolaeva, V. I. Safonov

1970-01-01

158

Gel Electrophoresis  

NSDL National Science Digital Library

In the early days of DNA manipulation, DNA fragments were laboriously separated by gravity. In the 1970s, the powerful tool of DNA gel electrophoresis was developed. This process uses electricity to separate DNA fragments by size as they migrate through a gel matrix. This animation from Cold Spring Harbor Laboratory's Dolan DNA Learning Center presents Gel Electrophoresis through a series of illustrations of the processes involved.

2012-01-20

159

Effect of polymer nature on the structure and properties of gel composites with incorporated bentonite particles  

Microsoft Academic Search

Composite gels based on polyacrylamide and poly(N-isopropyl acrylamide) with incorporated sodium bentonite particles are synthesized.\\u000a It is shown that the presence of hydrophobic isopropyl groups in a polymer molecule promotes the subsequent formation of highly\\u000a ordered aggregates of clay and cetylpyridinium chloride in a gel composite. An increase in temperature results in the collapse\\u000a of composite gels based on poly(N-isopropyl

E. K. Lavrent’eva; S. G. Starodubtsev; A. R. Khokhlov; V. V. Volkov; K. A. Dembo

2008-01-01

160

Diffusive transfer to membranes as an effective interface between gel electrophoresis and mass spectrometry  

Microsoft Academic Search

Diffusive transfer was examined as a blotting method to transfer proteins from polyacrylamide gels to membranes for ultraviolet matrix-assisted laser desorption ionization (MALDI) mass spectrometry. The method is well-suited for transfers from isoelectric focusing (IEF) gels. Spectra have been obtained for 11 pmol of 66 kDa albumin loaded onto an IEF gel and subsequently blotted to polyethylene. Similarly, masses of

Rachel R. Ogorzalek Loo; Charles Mitchell; Tracy I. Stevenson; Joseph A. Loo; Philip C. Andrews

1997-01-01

161

Amperometric biosensor for the detection of hydrogen peroxide using catalase modified electrodes in polyacrylamide.  

PubMed

A simple biosensor for the detection of hydrogen peroxide in organic solvents has been developed and coupled to a flow injection analysis (FIA) system. Catalase was entrapped in polyacrylamide gel and placed on the surface of platinum (working electrode) fixed in a Teflon holder with Ag-wire (auxiliary electrode), followed by addition of filter paper soaked in KCl. The entrapped catalase gel was held on the electrode using membranes. The effects of cellulose and polytetrafluroethylene (PTFE) membranes on the electrode response towards hydrogen peroxide have been studied. The modified electrode has been used to study the detection of hydrogen peroxide in solvents like water, dimethyl sulfoxide (DMSO), and 1,4-dioxane using amperometric techniques like cyclic voltammetry (CV) and FIA. The CV of modified catalase electrode showed a broad oxidation peak at -150 mV and a clear reduction peak at -212 mV in the presence of hydrogen peroxide. Comparison of CV with hydrogen peroxide in various solvents has been carried out. The electrode showed an irreversible kinetics with DMSO as the solvent. A flow cell has been designed in order to carry on FIA studies to obtain calibration plots for hydrogen peroxide with the modified electrode. The calibration plots in several solvents such as water, dimethyl sulfoxide, 1,4-dioxane have been obtained. The throughput of the enzyme electrode was 10 injections per hour. Due to the presence of membrane the response time of the electrode is concentration dependent. PMID:16099064

Varma, Shailly; Mattiasson, Bo

2005-09-23

162

Polyelectrolyte gels  

SciTech Connect

Polyelectrolyte (PE) gels are swollen polymer/solvent networks that undergo a reversible volume collapse/expansion through various types of stimulation. Applications that could exploit this large deformation and solvent expulsion/absorption characteristics include robotic {open_quotes}fingers{close_quotes} and drug delivery systems. The goals of the research were to first explore the feasibility of using the PE gels as {open_quotes}smart materials{close_quotes} - materials whose response can be controlled by an external stimulus through a feedback mechanism. Then develop a predictive capability to simulate the dynamic behavior of these gels. This involved experimentally characterizing the response of well-characterized gels to an applied electric field and other stimuli to develop an understanding of the underlying mechanisms which cause the volume collapse. Lastly, the numerical analysis tool was used to simulate various potential engineering devices based on PE gels. This report discusses the pursuit of those goals through experimental and computational means.

Segalman, D.J.; Witkowski, W.R.

1995-06-01

163

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

E-print Network

procedure of maintaining a supply of known species for use as standards. Many different electrophoretic contributed much towards eliminating problems of species substitution. Unfortunately, each of these techniques test. Varia- tions in stabilizing media composition, sample application technique, separation time

164

Formation of microemulsion: Effect of temperature and polyacrylamide  

Microsoft Academic Search

The pseudoternary phase diagram of the system involving cyclohexane, sodium dodecyl sulphate, propanol, and water was constructed for an SDS-to-propanol mass ratio 1:2. The area of the monophasic microemulsion region was computed. The effects of change of temperature and change of concentration of water-soluble polyacrylamide (PAA) on the microemulsion zone as well as the conductance, viscosity, and adiabatic compressibility of

A. C. John; A. K. Rakshit

1993-01-01

165

Histology and isozyme analysis of early infection of nearly isogenic susceptible and resistant maize cultivars by Puccinia polysora  

E-print Network

focusing (lEF) gels and native polyacrylamide gradient gels were both used. IEF PhastGels were homogeneous (5/o T, 3/. C) polyacrylamide gels containing ampholytes which created a continuous pH range from 3 to 9. IEF gels allow proteins to migrate under... focusing (lEF) gels and native polyacrylamide gradient gels were both used. IEF PhastGels were homogeneous (5/o T, 3/. C) polyacrylamide gels containing ampholytes which created a continuous pH range from 3 to 9. IEF gels allow proteins to migrate under...

Hanson, Lynn Ann

2012-06-07

166

Native Intelligence  

ERIC Educational Resources Information Center

Amid concerns from tribal leaders that No Child Left Behind testing is squeezing out electives that have traditionally covered their history and cultures, an ambitious brace of programs is making Native America part of the core curriculum at David Wolfle Elementary School and other schools in the western Washington State. By tapping into…

Seven, Richard

2006-01-01

167

Improving immobilized biocatalysts by gel phase polymerization  

SciTech Connect

A new method is presented for the treatment of gel-type supports, used for immobilizing microbial cells and enzymes, to obtain high mechanical strength. It is particularly useful for ethanol fermentation over gel beads containing immobilized viable cells, where the beads can be ruptured by gas production and the growth of cells within the gels. This method consists of treating agar or carrageenan gel with polyacrylamide to form a rigid support which retains the high catalytic activity characteristic of the untreated biocatalysts. The size and shape of the biocatalyst is unaffected by this treatment. The method involves the diffusion of acrylamide, N,N'-methylenebisacrylamide and ..beta..-dimethylaminopropionitrile (or N,N,N',N'-tetramethylethylenediamine) into the preformed biocatalyst beads followed by the addition of an initiator to cause polymerization within the beads. Treated gels have been used for the continuous fermentation of glucose to ethanol in a packed column for over two months. During this operation, the gel beads maintained their rigidity, and the maximum productivity was as high as 50 gh/sup -1/ L/sup -1/ gel. There was no appreciable decay of cell activity.

Kuu, W.Y.; Polack, J.A.

1983-08-01

168

Effect of gel structure of matrix orientation in pulsed alternating electric fields  

SciTech Connect

Four polymeric gels with different structures, LE agarose, HEEO agarose, beta-carrageenan, and polyacrylamide, were studied by transient electric birefringence to determine the importance of various structural features on the orientation of the gels in pulsed alternating electric fields. The birefrigence relaxation times observed for agarose gels in low voltage electric fields suggest that long fibers and/or domains, ranging up to tens of microns in size, are oriented by the electric field. The sign of the birefringence reverses when the direction of the electric field is reversed, suggesting that the oriented domains change their direction of orientation from parallel to perpendicular (or vice versa) when the polarity of the electric field is reversed. These anamalous orientation effects are observed with both types of agarose gels, but not with beta-carrageenan or polyacrylamide gels, suggesting that the alternating D,L galactose residues in the agarose backbone are responsible for the anomalies.

Stellwagen, N.C.; Stellwagen, J. [Univ. of Iowa, Iowa City, IA (United States)

1993-12-31

169

Ultrasonic Velocity Studies and Allied Parameters of Polyacrylamide\\/Polyethyleneglycol (600) and Polyacrylamide\\/Polyvinylalcohol Blend Solution at Low Concentrations  

Microsoft Academic Search

Viscosity, adiabatic compressibility, intermolecular free length, and acoustic impedance of polyacrylamide in polyethylene glycol (600) and polyvinyl alcohol polymer blended solutions at 303 K have been evaluated from ultrasonic (2 MHz) measurements of their density. The results have been interpreted in light of polymer–solvent and polymer–polymer interactions. Variations in the compatibility of the blends caused by increases of PEG (600) and polyvinyl

S. Ravichandran; K. Ramanathan

2008-01-01

170

Superoxide dismutase isozyme detection using two-dimensional gel electrophoresis zymograms.  

PubMed

Superoxide dismutases (SODs) are ubiquitous antioxidant enzymes involved in cell protection from reactive oxygen species. Their antioxidant activities make them of interest to applied biotechnology industries and are usually sourced from plants. SODs are also involved in stress signaling responses in plants, and can be used as indicators of these responses. In this article, a suitable method for the separation of different SOD isoforms using two-dimensional-gel electrophoresis (2D-GE) zymograms is reported. The method was developed with a SOD standard from bovine erythrocytes and later applied to extracts from Stemona tuberosa. The first (non-denaturing isoelectric focusing) and second (denaturing sodium dodecylsulphate-polyacrylamide gel electrophoresis) dimensions of duplicate 2D-GE gels were stained with either Coomassie brilliant blue G-250 for total protein visualization, or SOD activity (zymogram) using riboflavin/nitroblue tetrazolium. For confirmation, putative SOD activity positive spots were subject to trypsin digestion and nano-liquid chromatography tandem mass spectrometry, followed by searching the MASCOT database for potential identification. The method could separate different SOD isoforms from a plant extract and at least partially maintain or allow renaturation to the native forms of the enzyme. Peptide sequencing of the 2D-GE suggested that the SODs were resolved correctly, identifying the control CuZn-SOD from bovine erythrocytes. The two SODs from S. tuberosa tubers were found to be likely homologous of a CuZn-SOD. SOD detection and isoform separation by 2D-GE zymograms was efficient and reliable. The method is likely applicable to SOD detection from plants or other organisms. Moreover, a similar approach could be developed for detection of other important enzymes in the future. PMID:24334192

Niyomploy, Ploypat; Srisomsap, Chantragan; Chokchaichamnankit, Daranee; Vinayavekhin, Nawaporn; Karnchanatat, Aphichart; Sangvanich, Polkit

2014-03-01

171

Polyelectrolyte gels  

Microsoft Academic Search

Polyelectrolyte (PE) gels are swollen polymer\\/solvent networks that undergo a reversible volume collapse\\/expansion through various types of stimulation. Applications that could exploit this large deformation and solvent expulsion\\/absorption characteristics include robotic {open_quotes}fingers{close_quotes} and drug delivery systems. The goals of the research were to first explore the feasibility of using the PE gels as {open_quotes}smart materials{close_quotes} - materials whose response can

D. J. Segalman; W. R. Witkowski

1995-01-01

172

Binding and covalent cross-linking of purified von Willebrand factor to native monomeric collagen.  

PubMed Central

We have analyzed the interaction of the adhesive glycoprotein, von Willebrand factor (vWF), with native monomeric collagen monolayers by adsorbing acid soluble Types I and III collagen derived from calf skin to polystyrene microtiter wells and incubating the wells with purified human 125I-vWF. The binding of 125I-vWF was saturable, reversible, specific, and was abolished by heat denaturation of the collagen monomers. Binding was half-maximal at 5 micrograms/ml, and, at saturation, 7.5 ng 125I-vWF were bound to each microgram of immobilized collagen. 125I-vWF did not bind to wells coated with other extracellular matrix or plasma proteins such as fibronectin, fibrinogen, gelatin, or the q subunit of the first component of complement (C1q). In addition, bound 125I-vWF could not be displaced from collagen by the addition of either fibronectin or fibrinogen. After incubation with Factor XIIIa, plasma transglutaminase, 125I-vWF bound to collagen could no longer be displaced by vWF, which suggests covalent cross-linking of vWF to collagen monomers. Factor XIIIa-dependent covalent cross-linking of vWF to collagen, but not to fibronectin or laminin, was also demonstrated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Images PMID:2874156

Bockenstedt, P; McDonagh, J; Handin, R I

1986-01-01

173

Cationic polyacrylamides enhance rates of starch and cellulose saccharification.  

PubMed

Adding a cationic polyacrylamide (c-PAM) to either the amylase mediated hydrolysis of corn starch or the hydrolysis of wood fiber by cellulase can enhance the initial hydrolysis rates, although a rate decrease can occur under some conditions. Several c-PAMs can serve as catalysts and the same c-PAM can improve the efficiency of both amylase and cellulase. The initial amylase rate approximately doubles; the analogous cellulase hydrolysis rate increases by about 40%. c-PAMs increase the binding of enzyme to substrate. PMID:19547927

Reye, John T; Maxwell, Kendra; Rao, Swati; Lu, Jian; Banerjee, Sujit

2009-10-01

174

Laser CT evaluation on normoxic PAGAT gel dosimeter  

NASA Astrophysics Data System (ADS)

Optical computed tomography has been shown to be a potentially useful imaging tool for the radiation therapy physicists. In radiation therapy, researchers have used optical CT for the readout of 3D dosimeters. The purpose of this paper is to describe the initial evaluation of a newly fabricated laser CT scanner for 3D gel dosimetry which works using the first generation principle. A normoxic PAGAT (Polyacrylamide Gelatin and Tetrakis) gel is used as a dosimeter for this analysis. When a laser passes through the gel phantom, absorption and scattering of photon take place. The optical attenuation coefficient of the laser can be obtained by measuring its intensity after passing through the gel by a sensor. The scanner motion is controlled by a computer program written in Microsoft Visual C++. Reconstruction and data analysis on the irradiated gel phantom is performed by suitable algorithm using Matlab software.

Kumar, D. S.; Samuel, E. J. J.; Watanabe, Y.

2013-06-01

175

Electric Field Enhanced Diffusion of Salicylic Acid through Polyacrylamide Hydrogels  

NASA Astrophysics Data System (ADS)

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.

Niamlang, Sumonman; Sirivat, Anuvat

2008-03-01

176

Determination of polyacrylamides in coal washery effluents by ultrafiltration/site-exclusion chromatography-ultraviolet detection techniques  

SciTech Connect

The use of a combined technique of ultrafiltration and aqueous size-exclusion high-performance liquid chromatography-UV detection for monitoring trace levels of residual polyacrylamide flocculants in coal washery process water is described. Flocculants of both anionic and non-ionic types in effluents are analyzed by chromatography on a TSK 5000 PW type hydrophilic and semirigid porous polymer gel with 0.05 M Na/sub 2/SO/sub 4/ in water as the mobile phase and by UV detection at 208-nm wavelength for detection. Precision studies gave a relative standard deviation of 5.8% and a precision of 2.2% at the 95% confidence level in the concentration range of 20 ppm. The lower limit of detection for the method is 1.0 ..mu..g. Prior to chromatography, fractionation and concentration of the polyacrylamide in effluents are achieved by ultrafiltration with a hollow fiber cartridge having a nominal molecular weight cutoff of 100,000, and recoveries are determined by spiking studies. The application of the techniques for the analysis of residual flocculant in a coal washery thickener feed effluent sample is described.

Leung, R.W.M.; Pandey, R.N.; Das, B.S.

1987-05-01

177

Reprogramming cellular phenotype by soft collagen gels.  

PubMed

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

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

2014-10-23

178

Production of Antibodies Using Proteins in Gel Bands  

Microsoft Academic Search

\\u000a A number of methods for preparing proteins as antigens have been described (1). These include solubilization of protein samples in buffered solutions (ref. 2 and see Chapter 120), solubilization of nitrocellulose filters to which proteins have been adsorbed (ref. 3 and see Chapter 122), and emulsification of protein bands in polyacrylamide gels for direct injections (4–8). The latter technique can

Sally Ann Amero; Tharappel C. James; Sarah C. R. Elgin

179

Flocculation activity of novel ferric chloride–polyacrylamide (FeCl 3PAM) hybrid polymer  

Microsoft Academic Search

A ferric chloride–polyacrylamide inorganic–organic hybrid polymer has been synthesized using a ferric chloride\\/polyacrylamide ratio of 1:1 via free radical solution polymerization. A redox initiation system - (NH4)2S2O8 and NaHSO3 was used to initiate the polymerization at 50°C in aqueous medium. The ferric chloride–polyacrylamide hybrid polymer was characterized using Fourier transform infrared (FT-IR) spectrometer to determine their functional groups in the

Khai Ern Lee; Tjoon Tow Teng; Norhashimah Morad; Beng Teik Poh; Mohanapriya Mahalingam

2011-01-01

180

Technical notes on acrylamide gel electrophoresis used for comparing isozymes of mosquito larvae.  

PubMed

Various slight modifications of electrophoretic techniques were tried to obtain more reproducible results for comparing several isozymes with individual mosquito larvae. Horizontal electrophoresis was done using polyacrylamide gel plates of 1 mm thickness on a simple cooling system in which ice-cold water was circulated. This made it possible to carry out electrophoresis effectively even during field work in tropical areas. Gel concentration in routine work is 5% for usual enzymes, but for esterase, 6% gels have been adopted. Gel concentrations, running distance, running time, visualization of isozyme bands, etc., have especially been considered. PMID:6148783

Tsukamoto, M

1984-06-01

181

Microplate array diagonal gel electrophoresis (MADGE), CpG-PCR and temporal thermal ramp-MADGE (Melt-MADGE) for single nucleotide analyses in populations  

Microsoft Academic Search

Important requirements for molecular genetic epidemiological studies are economy, sample parallelism, convenience of setup and accessibility, goals inadequately met by existent approaches. We invented microplate array diagonal gel electrophoresis (MADGE) to gain simultaneously the advantages of simple setup, 96-well microplate compatibility, horizontal electrophoresis, and the resolution of polyacrylamide. At essentially no equipment cost (one simple plastic gel former), 10–100-fold savings

Ian N. M. Day; Sandra D. O’Dell; Emmanuel Spanakis; Glenn P. Weavind

1999-01-01

182

Optimization of the mineral content in polymeric gels: The effect of calcium to phosphate molar ratio  

Microsoft Academic Search

The influence of calcium to phosphate (Ca\\/P) molar ratio on the extent of mineralization in a model (poly)acrylamide gel was investigated under simulated physiological conditions. We hypothesized that the optimal growth of hydroxyapatite crystals will take place at the stoichiometric Ca\\/P molar ratio of 1.67. Phosphate ions were incorporated during the polymerization of the gel and mineralization was initiated by

Prasenjit Das; Ozan Akkus; Abdul-Majeed Azad

2005-01-01

183

Two-dimensional gel studies of genetic variation in the plasma proteins of Amerindians and Japanese  

Microsoft Academic Search

Genetic variation has been studied in plasma samples from 107 Amerindian children and their parents, and 110 Japanese children and their parents by means of two-dimensional polyacrylamide gel electrophoresis. Twenty-three polypeptides were scored; the identity of nine of these is at present still unknown. Genetic variation was encountered in 11 of these polypeptides. We have previously reported that the index

Jun-ichi Asakawa; Norio Takahashi; Barnett B. Rosenblum; James V. Neel

1985-01-01

184

Microsequence analysis of winged bean seed proteins electroblotted from two-dimensional gel  

Microsoft Academic Search

Electroblotting method employing a semidry blotting apparatus for the subsequent protein microsequence analysis (Hirano, 1987) was improved. This method is convenient and allows rapid and efficient transfer of the proteins from a polyacrylamide gel (1 mm thick) onto the Polybrene-coated glass-fiber sheet or polyvinylidene difluoride membrane filter in only 20 min. The electroblotted proteins could be sequenced directly with the

Hisashi Hirano

1989-01-01

185

Alaska Native Hispanic or  

E-print Network

fCOLLEGEo CHARLESTON American Indian or Alaska Native Asian Black or African American Hispanic Indian or Alaska Native Asian Black or African American Hispanic or Latino Native Hawaiian or Other Enrolled American Indian or Alaska Native Asian Black or African American Hispanic or Latino Native

Kunkle, Tom

186

Porous Polyacrylamide Monoliths in Hydrophilic Interaction Capillary Electrochromatography of Oligosaccharides  

PubMed Central

Capillary electrochromatography (CEC) of oligosaccharides in porous polyacrylamide monoliths has been explored. While it is possible to alter separation capacity for various compounds by copolymerization of suitable separation ligands in the polymerization backbone, “blank” acrylamide matrix is also capable of sufficient resolution of oligosaccharides in the hydrophilic interaction mode. The “blank” acrylamide network, formed with a more rigid crosslinker, provides maximum efficiency for separations (routinely up to 350,000 theoretical plates/m for fluorescently-labeled oligosaccharides). These columns yield a high spatial resolution of the branched glycan isomers and large column permeabilities. From the structural point of view, some voids are observable in the monoliths at the mesoporous range (mean pore radius ca. 35 nm, surface area of 74 m2/g), as measured by intrusion porosimetry in the dry state. PMID:17254635

Guryca, Vilem; Mechref, Yehia; Palm, Anders K.; Michalek, Jiri; Pacakova, Vera; Novotny, Milos V.

2007-01-01

187

Dielectric properties of gel collected from shark electrosensors  

NASA Astrophysics Data System (ADS)

To investigate the physical mechanism of the electric sense, we present an initial characterization of the dielectric properties of the glycoprotein gel that fills the electrosensitive organs of marine elasmobranches (sharks, skates, and rays). To ascertain the properties of the gel, low-frequency impedance spectroscopy is used. The impedance data collected from a dialyzed sample show large values of static permittivity and a loss peak corresponding to a long relaxation time (about 1 ms). Impedance measurements of the native (nondialyzed) gel reliable to 0.1 Hz will be presented and compared to the dialyzed gel. Ramifications of the gel's dielectric properties for the electric sense will be explored.

Hughes, Mary E.; Brown, Brandon R.; Hutchison, John C.; Murray, Royce W.

2003-03-01

188

Management for Postoperative Complications of Breast Augmentation by Injected Polyacrylamide Hydrogel  

Microsoft Academic Search

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

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

2005-01-01

189

Rheology of ?-carrageenan and ?-lactoglobulin mixed gels  

Microsoft Academic Search

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

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

2000-01-01

190

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

PubMed Central

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

2012-01-01

191

Native American Discursive Tactic  

ERIC Educational Resources Information Center

This essay derives from a course called ‘"The Rhetoric of Native America,’" which is a historical-critical survey of Native American primary texts. The course examines the rhetoric employed by Natives to enact social change and to build community in the face of exigencies. The main goal of exploring a native text (particularly, Simon Pokagon's…

Black, Jason Edward

2013-01-01

192

Electrophoretic extraction of proteins from two-dimensional electrophoresis gel spots  

DOEpatents

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. 8 figs.

Zhang, Jian-Shi; Giometti, C.S.; Tollaksen, S.L.

1987-09-04

193

A Gel Probe Equilibrium Sampler for Measuring Arsenic Porewater Profiles And Sorption Gradients in Sediments: I. Laboratory Development  

SciTech Connect

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.

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

2009-05-14

194

Investigation on Tissue Equivalent Normoxic Polymer Gel Dosimeter using In-house Laser CT scanning system  

NASA Astrophysics Data System (ADS)

Optical Computed Tomography has wide applications in the treatment of cancer. In continuation of this, an in-house Laser CT scanner has been built for "3D gel dosimetry". The Laser CT (LCT) scanner plays a major for Gel dosimeter or phantom readout and in clinical radiation therapy as a 3-Dimensional Radiation Dosimetry. A gel dosimeter which absorbs dose in a tissue-equivalent manner and allows the measurement of spatial distribution of the deposited dose is required. The normoxic PAGAT (Polyacrylamide Gelatin and Tetrakis) gel is used as a dosimeter for this analysis. When laser passes through this gel phantom, absorption and scattering takes place and combined to attenuation. The optical attenuation coefficient of the laser can be obtained by measuring its intensity after passing through the gel by means of a sensor. Reconstruction using Mat Lab algorithm provides 3D dose distribution.

Senthil Kumar, D.; Jebaseelan Samuel, E. James

2010-11-01

195

Evaluation of Erosion Control Products With and Without Added Polyacrylamide  

NASA Astrophysics Data System (ADS)

Polyacrylamide (PAM) has been demonstrated to greatly reduce erosion in furrow irrigation, but much less is known about its effectiveness on the much steeper slopes typical of construction sites. The purpose of this study was to determine if anionic PAM would enhance erosion control either alone on bare soil or in combination with four types of ground covers commonly used for grass establishment: straw, straw erosion control blanket (ECB), wood fiber, and mechanically bonded fiber matrix (MBFM). Tests were conducted under natural rainfall and vegetation on a 4 percent slope (bare soil, straw, ECB, and MBFM) or using a rainfall simulator (bare soil, straw, wood fiber, MBFM) on either 10 percent or 20 percent slope on three different soil substrates. All ground cover treatments were evaluated with and without PAM applied in solution at 19 kg/ha. The straw, ECB, and MBFM significantly reduced runoff volume, average turbidity, and total sediment lost over five rainfall events on the vegetated plots. The addition of PAM to ground covers only occasionally had significant effects on runoff parameters but did significantly increase vegetative coverage overall. The rainfall simulator tests produced similar results after four events, with the straw, wood fiber, and MBFM all having significantly lower turbidity than the bare soil. The PAM significantly reduced turbidity for both the first and second events but did not consistently improve runoff quality after multiple rainfall events for any ground cover-soil combinations tested. Separate tests of PAM applied before or after straw did not indicate a clear advantage of either approach, but runoff turbidity was often significantly reduced with PAM, especially at the 20 percent slope. Turbidity reductions were attributed to flocculation of eroded sediment.

McLaughlin, Richard A.; Brown, Tabitha T.

2006-06-01

196

Detection of human butyrylcholinesterase-nerve gas adducts by liquid chromatography–mass spectrometric analysis after in gel chymotryptic digestion  

Microsoft Academic Search

To verify the exposure to nerve gas, a method for detecting human butyrylcholinesterase (BuChE)-nerve gas adduct was developed using LC–electrospray mass spectrometry (ESI-MS). Purified human serum BuChE was incubated with sarin, soman or VX, and the adduct was purified by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) and digested in gel by treatment with chymotrypsin. The resulting peptide mixture was subjected

Kouichiro Tsuge; Yasuo Seto

2006-01-01

197

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

Code of Federal Regulations, 2012 CFR

...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...

2012-04-01

198

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

...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...

2014-04-01

199

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

Code of Federal Regulations, 2013 CFR

...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...

2013-04-01

200

Restoring Native Grasslands  

E-print Network

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...

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

2005-03-23

201

How deeply cells feel: methods for thin gels  

PubMed Central

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

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

2010-01-01

202

Native American Healing Traditions  

ERIC Educational Resources Information Center

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…

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

2006-01-01

203

Alaska Natives & the Land.  

ERIC Educational Resources Information Center

Pursuant to the Native land claims within Alaska, this compilation of background data and interpretive materials relevant to a fair resolution of the Alaska Native problem seeks to record data and information on the Native peoples; the land and resources of Alaska and their uses by the people in the past and present; land ownership; and future…

Arnold, Robert D.; And Others

204

Laser light scattering studies of biological gels  

NASA Astrophysics Data System (ADS)

Several authors have investigated the Rayleigh linewidth of light scattered from the gels of cross-linked flexible polymers such as polyacrylamide14. The width of the spectral broadening varies as sinL(O/2), and diffusion coefficients may be calculated in the same way as for a macromolecular solution5. According to the theory of Tanaka et al.1, this corresponds to freely diffusing fluctuations in polymer segment density and is equal to the ratio of the longitudinal elastic modulus to the force per unit volume required to maintain unit relative velocity between the polymer network and solvent. The degree of spectral broadening has, in general, been found to be small enough (ca. 10%) for the optical beating to be regarded as largely heterodyne, most of the scattered light arising from a stationary component in the density fluctuations.

Burne, P. M.; Sellen, D. B.

1991-05-01

205

2012 National Native American Heritage Month Native American House  

E-print Network

2012 National Native American Heritage Month Native American House Community Service Project Adopt a Native Elder November 1-30th Drop off location: Native American House, Monday thru Friday 9am-5pm Sponsored by: Native American House (NAH), Native American Student Organization (NASO), American Indian

Kravets, Robin

206

Fundamentals of gel dosimeters  

NASA Astrophysics Data System (ADS)

Fundamental chemical and physical phenomena that occur in Fricke gel dosimeters, polymer gel dosimeters, micelle gel dosimeters and genipin gel dosimeters are discussed. Fricke gel dosimeters are effective even though their radiation sensitivity depends on oxygen concentration. Oxygen contamination can cause severe problems in polymer gel dosimeters, even when THPC is used. Oxygen leakage must be prevented between manufacturing and irradiation of polymer gels, and internal calibration methods should be used so that contamination problems can be detected. Micelle gel dosimeters are promising due to their favourable diffusion properties. The introduction of micelles to gel dosimetry may open up new areas of dosimetry research wherein a range of water-insoluble radiochromic materials can be explored as reporter molecules.

McAuley, K. B.; Nasr, A. T.

2013-06-01

207

Selective adsorption of hydrocarbon-oxidizing Rhodococcus cells in a column with hydrophobized poly(acrylamide) cryogel.  

PubMed

A method for selective adsorption of Rhodococcus cells in the column with hydrophobized poly(acrylamide) cryogel (cryoPAAG) was developed that allowed rhodococci separation from mixed bacterial populations and their effective concentration within a sponge-like gel matrix. Hydrophobization of cryoPAAG using the n-dodecane graft (C12) was performed to enhance the adhesion of Rhodococcus cells to the cryogel; this was suggested by our finding that alkanotrophic rhodococci possess high adhesive activity (91-98%) towards n-alkanes, whereas other Gram-positive and Gram-negative bacteria tested did not adhere strongly to hydrocarbons. The selective index of the hydrophobic C12-cryoPAAG column for Rhodococcus cells was 72% that ensured their separation from complex bacterial cultures. Respirometry results using the Columbus Micro-Oxymax respirometer showed that the maximal respiratory activity of C12-cryoPAAG-immobilized Rhodococcus cells incubated with petroleum hydrocarbons was 1.6-1.8 times higher than that of freely suspended cells, and this correlated with the largest immobilized cell number. Moreover, high respiration rates were maintained over 3 weeks of incubation, indicating a considerable functional stability of the cryoPAAG-immobilized biocatalyst developed. PMID:19682505

Kuyukina, Maria S; Rubtsova, Ekaterina V; Ivshina, Irena B; Ivanov, Roman V; Lozinsky, Vladimir I

2009-10-01

208

Enhanced removal of methylene blue and methyl violet dyes from aqueous solution using a nanocomposite of hydrolyzed polyacrylamide grafted xanthan gum and incorporated nanosilica.  

PubMed

The synthesis and characterization of a novel nanocomposite is reported that was developed as an efficient adsorbent for the removal of toxic methylene blue (MB) and methyl violet (MV) from aqueous solution. The nanocomposite comprises hydrolyzed polyacrylamide grafted onto xanthan gum as well as incorporated nanosilica. The synthesis exploits the saponification of the grafted polyacrylamide and the in situ formation of nanoscale SiO2 by a sol-gel reaction, in which the biopolymer matrix promotes the silica polymerization and therefore acts as a novel template for nanosilica formation. The detailed investigation of the kinetics and the adsorption isotherms of MB and MV from aqueous solution showed that the dyes adsorb rapidly, in accordance with a pseudo-second-order kinetics and a Langmuir adsorption isotherm. The entropy driven process was furthermore found to strongly depend on the point of zero charge (pzc) of the adsorbent. The remarkably high adsorption capacity of dyes on the nanocomposites (efficiency of MB removal, 99.4%; maximum specific removal Qmax, 497.5 mg g(-1); and efficiency of MV removal, 99.1%; Qmax, 378.8 mg g(-1)) is rationalized on the basis of H-bonding interactions as well as dipole-dipole and electrostatic interactions between anionic adsorbent and cationic dye molecules. Because of the excellent regeneration capacity the nanocomposites are considered interesting materials for the uptake of, for instance, toxic dyes from wastewater. PMID:24579659

Ghorai, Soumitra; Sarkar, Asish; Raoufi, Mohammad; Panda, Asit Baran; Schönherr, Holger; Pal, Sagar

2014-04-01

209

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

Federal Register 2010, 2011, 2012, 2013

...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...

2013-11-27

210

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

SciTech Connect

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.

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

2003-11-01

211

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

E-print Network

Technologies such as horizontal wells and multi-stage hydraulic fracturing have made ultra-low permeability shale and tight gas reservoirs productive but the industry is still on the learning curve when it comes to addressing various production...

Jayakumar, Swathika 1986-

2012-07-09

212

Comparison of methods for sample preparation of individual rat cerebrospinal fluid samples prior to two-dimensional polyacrylamide gel electrophoresis  

Microsoft Academic Search

Different pre-treatment methods have been compared for two-dimensional mapping of individual rat cerebrospinal fluid samples based on acetone, trichloroacetic acid\\/acetone and methanol\\/acetone precipitation of proteins. Acetone precipitation following incubation with DTT gave the highest protein recovery (72%) and the largest number of protein spots (92 ± 4) as well as minimizing the time taken.

Sonia Garcia-Rodriguez; Sandro Argüelles Castilla; Alberto Machado; Antonio Ayala

2003-01-01

213

Fluorescence studies of extracellular hemoglobin of Glossoscolex paulistus obtained by gel filtration  

Microsoft Academic Search

Chromatography in Sephadex G-200 of extracellular hemoglobin of the giant worm Glossoscolex paulistus presents a unique band at pH 7.0 and several bands at pH 9.0 as a result of alkaline dissociation. SDS-polyacrylamide gel electrophoresis (PAGE) of the intact protein obtained at pH 7.0 shows the existence of five different bands with molecular weights of 12 ± 1, 26 ±

Hidetake Imasato; Maria Helena Tinto; Janice R. Perussi; Marcel Tabak

1995-01-01

214

Elastic properties of swollen polyelectrolyte gels in aqueous salt solutions  

NASA Astrophysics Data System (ADS)

The elastic relaxation responding to a uniaxially stretched poly(acrylic acid) rodlike gel in the aqueous NaCl solution was investigated. The relaxation elucidated the shear (?) and bulk (K) moduli and the frictional coefficients (?) of the fully ionized gel at pH above 9 as functions of the degree of swelling, which was controlled by the NaCl concentration (CS) of the solution. Two gels, cross-linked chains of which consist of 500 (GelA500) and 50 (GelA50) monomeric units, were examined to investigate the effect of the chain length on the elastic behavior. The moduli of GelA500 increased with swelling at CS below 100 mM and decreased at CS above it. The ? values of both gels can be characterized by the power function of gel diameter, d as ? ?d?. The ? values being -1 at CS above 100 mM transitionally changed to 1.2 at CS about 100 mM. That is, the dimensionality of space for the chains to distribute, ndim {=(?+5)/(?+2) according to the conventional theory [Sasaki et al., J. Chem. Phys. 102, 5694 (1995)]}, changed from 4 (ndim of ideal chain) to 1.9 at CS=100mM. This indicates that the electrostatic repulsion between gel chains reduces the ndim at CS below 100 mM but not at CS above it. It was found that the K values of GelA500 were well described by the conventional theory but those of GelA50 not. The ?zr/?rr (?zr is an off-diagonal element of the friction coefficient tensor and ?rr is a diagonal element of the friction coefficient tensor) was found to be 2.7×10-2, which was the same as the previously reported value for the swollen poly(acrylamide) gel [Sasaki, J. Chem. Phys. 120, 5789 (2004)]. The ?rr of unit volume of the GelA500 is well explained by the free draining model while the ?rr of GelA50 is less than that of the free draining model, suggesting the slip between water and ionized chain.

Sasaki, Shigeo

2006-03-01

215

Native American Powerpoint Project  

NSDL National Science Digital Library

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 ...

Albright, Miss

2009-07-09

216

Running an Agarose Gel  

NSDL National Science Digital Library

This video adapted from the University of Leicester provides step-by-step instructions for loading samples into an agarose gel and then running the gel to separate DNA molecules according to their size.

Foundation, Wgbh E.

2011-11-07

217

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

ERIC Educational Resources Information Center

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…

Lee, Tiffany S.

2009-01-01

218

Historic Native Americans  

NSDL National Science Digital Library

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 ...

G, Miss

2011-10-27

219

Listen to the Natives  

ERIC Educational Resources Information Center

"Digital natives" refer to today's students because they are native speakers of technology, fluent in the digital language of computers, video games, and the Internet. Those who were not born into the digital world are referred to as digital immigrants. Educators, considered digital immigrants, have slid into the 21st century--and into the digital…

Prensky, Marc

2006-01-01

220

Native American Health  

Microsoft Academic Search

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.

Danielle Carlock

2006-01-01

221

Native American Entrepreneurship. Digest.  

ERIC Educational Resources Information Center

Although Native Americans have owned and started the fewest small businesses of all U.S. minority groups, entrepreneurship is considered to be an efficient tool for alleviating their economic problems. Barriers to Native American entrepreneurship include poverty, scarce start-up capital, poor access to business education and technical assistance,…

Seymour, Nicole

222

Traditional Native Poetry.  

ERIC Educational Resources Information Center

While Native myths and legends were educational tools to transmit tribal beliefs and history, traditional American Indian poetry served a ritualistic function in everyday life. Few traditional Native songs, which all poems were, survive; only Mayan and Aztec poems were written, and most of these were burned by a Spanish bishop. In addition, many…

Grant, Agnes

1985-01-01

223

Native Vegetation Planting Guidelines  

E-print Network

's Sustainability Strategy, and include success indicators for the period 2008-2014. A native planting strategy of the biodiversity success indicators for the foreseeable future. 2. Basis for Selection of Planting Species1 Native Vegetation Planting Guidelines Based on Sustainability Goals for the Macquarie Campus #12

Wang, Yan

224

Multilocus enzyme analysis in aerobic and anaerobic bacteria using gel electrophoresis-nitrocellulose blotting.  

PubMed

An optimized multilocus enzyme electrophoresis method, which involves polyacrylamide-agarose gel electrophoresis followed by electrophoretic transfers on nitrocellulose sheets, was developed for the analysis of enzyme polymorphism in several aerobic and anaerobic bacterial species including Staphylococcus aureus, Streptococcus pneumoniae, S. agalactiae, Klebsiella pneumoniae and K. oxytoca, Clostridium bifermentans and C. sordellii, and Prevotella bivia. Serial electrophoretic transfers (during 5-15 min each) from a single polyacrylamide gel could be achieved for most enzymes studied, and allowed an increased definition of enzyme bands on nitrocellulose as compared to migration gels. Four enzymes, which could not be blotted in such conditions, could still be stained in gels after blotting. Thus, the method allowed the combined analysis of several enzymes after a single gel electrophoresis separation. The analysis of enzyme polymorphism in the various species studied raised the interest of polymorphic loci such as esterase or glutamic-oxaloacetic transaminase for epidemiologic studies. The method characterized a genetic diversity of enzyme loci of S. pneumoniae higher than previously reported, and is thus convenient for the analysis of genetic relationships between related isolates. Since the present method reduces the tediousness of multilocus enzyme electrophoresis and requires experimental conditions that are not specific for the bacterial population studied, it may be proposed for rapid population genetics analysis of a wide variety of bacteria. PMID:10754243

Combe, M; Lemeland, J; Pestel-Caron, M; Pons, J

2000-04-15

225

Fluid diversion and sweep improvement with chemical gels in oil recovery processes. Final report  

SciTech Connect

The objectives of this project were to identify the mechanisms by which gel treatments divert fluids in reservoirs and to establish where and how gel treatments are best applied. Several different types of gelants were examined, including polymer-based gelants, a monomer-based gelant, and a colloidal-silica gelant. This research was directed at gel applications in water injection wells, in production wells, and in high-pressure gas floods. The work examined how the flow properties of gels and gelling agents are influenced by permeability, lithology, and wettability. Other goals included determining the proper placement of gelants, the stability of in-place gels, and the types of gels required for the various oil recovery processes and for different scales of reservoir heterogeneity. During this three-year project, a number of theoretical analyses were performed to determine where gel treatments are expected to work best and where they are not expected to be effective. The most important, predictions from these analyses are presented. Undoubtedly, some of these predictions will be controversial. However, they do provide a starting point in establishing guidelines for the selection of field candidates for gel treatments. A logical next step is to seek field data that either confirm or contradict these predictions. The experimental work focused on four types of gels: (1) resorcinol-formaldehyde, (2) colloidal silica, (3) Cr{sup 3+}(chloride)-xanthan, and (4) Cr{sup 3+}(acetate)-polyacrylamide. All experiments were performed at 41{degrees}C.

Seright, R.S.; Martin, F.D.

1992-09-01

226

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

E-print Network

Microfabricated Polyacrylamide Devices for the Controlled Culture of Growing Cells and Developing, and C. elegans nematode development. The devices can integrate PDMS layers and allow for temporal for the Controlled Culture of Growing Cells and Developing Organisms. PLoS ONE 8(9): e75537. doi:10.1371/journal

Tans, Sander

227

Technological Solutions for Erosion Control and Water Clarification using Polyacrylamide (PAM) and PAM blends  

Microsoft Academic Search

Years of research, corporate publications, patents and trademarks have led to a greatly improved and cost efficient erosion control technology. Development of new polyacrylamide (PAM) blends and delivery methodologies has resulted in a whole new class of in-situ erosion control and water clarification tools. Multi-disciplinary environmental industry projects for mining, construction, water treatment and biological research have proven this class

William Gowdy; Jerry Hanna; Steven R. Iwinski; Dave Martin

228

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

Microsoft Academic Search

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

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

2010-01-01

229

The influence of salt concentration on negative thixotropy in solutions of partially hydrolyzed polyacrylamide  

Microsoft Academic Search

The influence of NaCl concentration on negative thixotropy in aqueous glycerol solutions of partially hydrolyzed polyacrylamide have been investigated. It was found that negative thixotropy type I (a slow increase in viscosity with time of shearing) sets in at higher critical shear rates when the salt is present. On the other hand, critical shear rates for negative thixotropy type II

P. Bradna; O. Quadrat; D. Dupuis

1995-01-01

230

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

PubMed Central

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

2010-01-01

231

Swelling and shrinking of a polyelectrolyte gel induced by a salt solution  

NASA Astrophysics Data System (ADS)

The stability of a polyelectrolyte gel in solution results from a delicate balance between several competing thermodynamic forces, viz. (i) osmotic pressure of free ions in the gel, (ii) molecular interaction of solvent and polymer molecules, (iii) network elasticity, (iv) Debye-Htickel interaction of ions. That balance may be upset by a decrease of temperature and by the addition of salt to the solvent. This results in a decrease of osmotic pressure and collapse of the gel to a small fraction of the initial volume. The effect can be reversed by increasing temperature and by removing salt from the solution. This paper presents an attempt to describe swelling and shrinking quantitatively and to understand the nature of the opposing forces. The volume of a particular polyacrylamide gel in a water acetone solution is represented as a function of the salt content and of temperature.

Rydzewski, R.

1990-05-01

232

Non-native Ants Are Smaller than Related Native Ants.  

PubMed

I compare the sizes of non-native and native ants to evaluate how worker size may be related to the ability of a species to invade new habitats. I compare the size of 78 non-native ant species belonging to 26 genera with the size of native congeneric species; native ants are larger than non-native ants in 22 of 26 genera. Ants were sorted by genera into fighting and nonfighting groups, based on observations of interspecific interactions with other ant species. In all of the genera with monomorphic worker castes that fight during competition, the non-native species were smaller than the native species. The genera that engage in combat had a higher frequency of significantly smaller size in non-native ants. I selected Wasmannia auropunctata for further studies, to compare native and non-native populations. Specimens of W. auropunctata from non-native populations were smaller than conspecific counterparts from its native habitat. I consider hypotheses to explain why non-native ants are smaller in size than native ants, including the role of colony size in interspecific fights, changes in life history, the release from intraspecific fighting, and climate. The discovery that fighting non-natives are smaller than their closest native relatives may provide insight into the mechanisms for success of non-native species, as well as the role of worker size and colony size during interspecific competition. PMID:10600613

McGlynn

1999-12-01

233

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.

234

Separation of membrane protein complexes by native LDS-PAGE.  

PubMed

Gel electrophoresis has become one of the most important methods for the analysis of proteins and protein complexes in a molecular weight range of 1-10(7) kDa. The separation of membrane protein complexes remained challenging to standardize until the demonstration of Blue Native PAGE in 1991 [1] and Clear Native PAGE in 1994 [2]. We present a robust protocol for high-resolution separation of photosynthetic complexes from Arabidopsis thaliana using lithium dodecyl sulfate as anion in a modified Blue Native PAGE (LDS-PAGE). Here, non-covalently bound chlorophyll is used as a sensitive probe to characterize the assembly/biogenesis of the pigment-protein complexes essential for photosynthesis. The high fluorescence yield recorded from chlorophyll-binding protein complexes can also be used to establish the separation of native protein complexes as an electrophoretic standard. PMID:24136555

Arnold, Janine; Shapiguzov, Alexey; Fucile, Geoffrey; Rochaix, Jean-David; Goldschmidt-Clermont, Michel; Eichacker, Lutz Andreas

2014-01-01

235

Native American Tribal Websites.  

ERIC Educational Resources Information Center

Lists Web sites maintained by 38 different Native American nations that deal with topics ranging from tribal history, news, arts and crafts, tourism, entertainment, and commerce. Represented nations include Apache, Blackfeet, Creek, Iroquois, Mohegan, and Sioux. (CMK)

Miller, Eric L.

1999-01-01

236

Natively probabilistic computation  

E-print Network

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 ...

Mansinghka, Vikash Kumar

2009-01-01

237

Native American Identity  

ERIC Educational Resources Information Center

Many issues and elements--including ethnic nomenclature, racial attitudes, and the legal and political status of American Indian nations and Indian people--influence Native American identity. (Contains 3 notes.)

Horse, Perry G.

2005-01-01

238

Alaska Native Science Commission  

NSDL National Science Digital Library

This is the homepage of the Alaska Native Science Commission (ANSC), an organization dedicated to bringing together research and science in partnership with the Native community. Site materials include information on Alaska Native communities; a searchable database of contacts for community knowledge and a directory of local, statewide, and federally recognized Alaska Native agencies. There is also information on organizational ethics and protocols, regulatory agencies, a browsable database of research projects, and information on sources of funding. The Key Issues page provides information on issues of concern, such as avian flu, climate change, observations about contaminants and environmental change, traditional knowledge systems, traditional foods, and views on climate change and ecology. For students, there is information on einternship and scholarship opportunities. The publications page provides access to archived newsletters, presentations, and reports.

2010-10-05

239

Native Health Research Database  

MedlinePLUS

... THIS APP WITH JAVASCRIPT TURNED OFF. THE NATIVE HEALTH DATABASE REQUIRES JAVASCRIPT IN ORDER TO FUNCTION. PLEASE ... Data and Links, U.S. Census Bureau American Indian Health from the National Library of Medicine Arctic Health ...

240

CONFORMANCE IMPROVEMENT USING GELS  

SciTech Connect

This report describes work performed during the second year of the project, ''Conformance Improvement Using Gels.'' The project has two objectives. The first objective is to identify gel compositions and conditions that substantially reduce flow through fractures that allow direct channeling between wells, while leaving secondary fractures open so that high fluid injection and production rates can be maintained. The second objective is to optimize treatments in fractured production wells, where the gel must reduce permeability to water much more than that to oil. Pore-level images from X-ray computed microtomography were re-examined for Berea sandstone and porous polyethylene. This analysis suggests that oil penetration through gel-filled pores occurs by a gel-dehydration mechanism, rather than a gel-ripping mechanism. This finding helps to explain why aqueous gels can reduce permeability to water more than to oil. We analyzed a Cr(III)-acetate-HPAM gel treatment in a production well in the Arbuckle formation. The availability of accurate pressure data before, during, and after the treatment was critical for the analysis. After the gel treatment, water productivity was fairly constant at about 20% of the pre-treatment value. However, oil productivity was stimulated by a factor of 18 immediately after the treatment. During the six months after the treatment, oil productivity gradually decreased to approach the pre-treatment value. To explain this behavior, we proposed that the fracture area open to oil flow was increased substantially by the gel treatment, followed by a gradual closing of the fractures during subsequent production. For a conventional Cr(III)-acetate-HPAM gel, the delay between gelant preparation and injection into a fracture impacts the placement, leakoff, and permeability reduction behavior. Formulations placed as partially formed gels showed relatively low pressure gradients during placement, and yet substantially reduced the flow capacity of fractures (with widths from 1 to 4 mm) during brine and oil flow after placement. Regardless of gel age before placement, very little gel washed out from the fractures during brine or oil flow. However, increased brine or oil flow rate and cyclic injection of oil and water significantly decreased the level of permeability reduction. A particular need exists for gels that can plug large apertures (e.g., wide fractures and vugs). Improved mechanical strength and stability were demonstrated (in 1- to 4-mm-wide fractures) for a gel that contained a combination of high- and low-molecular weight polymers. This gel reduced the flow capacity of 2- and 4-mm-wide fractures by 260,000. In a 1-mm-wide fracture, it withstood 26 psi/ft without allowing any brine flow through the fracture. Cr(III)-acetate-HPAM gels exhibited disproportionate permeability reduction in fractures. The effect was most pronounced when the gel was placed as gelant or partially formed gels. The effect occurred to a modest extent with concentrated gels and with gels that were ''fully formed'' when placed. The effect was not evident in tubes. We explored swelling polymers for plugging fractures. Polymer suspensions were quickly prepared and injected. In concept, the partially dissolved polymer would lodge and swell to plug the fracture. For three types of swelling polymers, behavior was promising. However, additional development is needed before their performance will be superior to that of conventional gels.

Randall S. Seright

2003-09-01

241

Immigration and native welfare  

Microsoft Academic Search

We unify two approaches towards identifying native welfare effects of immigration, one emphasizing the immigration surplus (Borjas, 1995,1999), the other identifying a welfare loss due to terms-of-trade effects (Davis & Weinstein, 2002). We decompose the native welfare effect of immigration into the standard complementarity effect, augmented by a Stolper-Samuelson effect, and a terms-of-trade effect. Using a structural model with three

Gabriel J. Felbermayr; Wilhelm Kohler

2004-01-01

242

OKLAHOMA NATIVE AMERICAN YOUTH LANGUAGE FAIR Native American Language Book  

E-print Network

OKLAHOMA NATIVE AMERICAN YOUTH LANGUAGE FAIR Native American Language Book Category Description Students are invited to enter books in a Native American language. Please remember the point of the ONAYLF is to demonstrate Native American language use. Keep this in mind when creating your book or instructing students

Oklahoma, University of

243

Problems in sampling the Native American and Alaska Native populations  

Microsoft Academic Search

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

EUGENE P. ERICKSEN

1997-01-01

244

Complex Pattern Formation in the Polyacrylamide-Methylene Blue-Oxygen Reaction Oliver Steinbock,*, Eric Kasper, and Stefan C. Mu1ller  

E-print Network

Complex Pattern Formation in the Polyacrylamide-Methylene Blue-Oxygen Reaction Oliver SteinbockVersita¨tsplatz 2, D-39106 Magdeburg, Germany ReceiVed: February 23, 1999 The polyacrylamide-methylene blue of reaction time and initial sulfide concentration. Introduction The polyacrylamide-methylene blue-oxygen (PA

Steinbock, Oliver

245

Gel mobility shift assays for RNA binding viral RNAi suppressors.  

PubMed

The host-virus interaction is a continuous coevolutionary race involving both host defence strategies and virus escape mechanisms. RNA silencing is one of the main processes employed by eukaryotic organisms to fight viruses. However, viruses encode suppressor proteins to counteract this antiviral mechanism. Virtually all plant viruses encode at least one suppressor. In spite of being highly diverse at the protein level, a large group of these proteins inhibit RNA silencing very similarly, by sequestration of double-stranded RNA or small-interfering RNA molecules, the central players of the pathway. The RNA binding capacity of virus suppressor proteins can be studied by the electrophoretic mobility shift assay method. Also known as gel retardation assay, gel mobility assay, gel shift assay or band shift assay, EMSA is an in vitro technique used to characterize protein:DNA or protein:RNA interactions. The method had been developed based on the observation that protein: nucleic acid complexes migrate slower through a non-denaturing polyacrylamide gel than the free nucleic acid fragments. Here, we provide a detailed protocol for the analysis of crucifer-infecting Tobacco mosaic tobamovirus (cr-TMV) silencing suppressor protein p122 RNA binding capacity. PMID:21431690

Csorba, Tibor; Burgyán, József

2011-01-01

246

Delivery of bioactive, gel-isolated proteins into live cells.  

PubMed

The delivery of proteins into live cells is a promising strategy for the targeted modulation of protein-protein interactions and the manipulation of specific cellular functions. Cellular delivery can be facilitated by complexing the protein of interest with carrier molecules. Recently, an amphipatic peptide was identified, Pep-1 (KETWWETWWTE WSQPKKKRKV), which crosses the plasma membrane of many cell types to carry and deliver proteins as large as antibodies. Pep-1 effectively delivers proteins in solution; but Pep-1 is not suitable for delivering sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) isolated proteins because Pep-1 complexes with cargo proteins are destroyed by SDS. Here, we report cellular delivery of SDS-PAGE-isolated proteins, without causing cellular damage, by using a nonionic detergent, Triton X-100, as carrier. To determine the specificity of our method, we separated antibodies against different intracellular targets by nonreducing SDS-PAGE. Following electrophoresis, the antibody bands were detected by zinc-imidazole reverse staining, excised, in-gel refolded with Triton X-100, and eluted in detergent-free phosphate-buffered saline. When overlaid on cultured NIH 3T3 cells, the antibodies penetrated the cells localizing to their corresponding intracellular targets. These results are proof-of-principle for the delivery of gel-isolated bioactive proteins into cultured cells and suggest new ways for experimental protein therapy and for studying protein-protein interactions using gel-isolated protein. PMID:12731017

Taylor, Jennifer E; Fernandez-Patron, Carlos

2003-05-01

247

CONFORMANCE IMPROVEMENT USING GELS  

SciTech Connect

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.

Randall S. Seright

2004-09-30

248

Montana State University Native American  

E-print Network

1 Montana State University Native American College Funding Guide Melanie Woods Admissions & New ­ 5 Types of Financial Aid 5 ­ 6 Helpful Websites 6 ­ 11 Sources For Native American Students 6 Native American Financial Aid 7 Eligibility for Native American Scholarships 7 MSU Campus Scholarships 7 Montana

Dyer, Bill

249

Updated: April 2013 Alaska Native  

E-print Network

fCOLLEGEo CHARLESTON Updated: April 2013 American Indian or Alaska Native Asian Black or African or Alaska Native Asian Black or African American Hispanic or Latino Native Hawaiian or Other Pacific of C Acceptances who Enrolled American Indian or Alaska Native Asian Black or African American Hispanic

Kunkle, Tom

250

Polyacrylamide brush layer for hydrophilic interaction liquid chromatography of intact glycoproteins.  

PubMed

A chromatographic column of nonporous silica particles with a bonded phase of linear polyacrylamide chains is evaluated for hydrophilic interaction liquid chromatography (HILIC) of intact glycoproteins. The column is shown to retain glycoproteins significantly more strongly than non-glycoproteins. A particle diameter of 700nm gives two-fold higher resolution than does a 1.4?m particle diameter, and the column efficiency is found to be mostly limited by packing heterogeneity. LCMS is able to resolve the five glycoforms of ribonuclease B and give high quality mass spectra, but there is loss of resolution of the isomers of glycoforms due to the lower amount of TFA. Compared to two leading commercial HILIC columns operated at 60°C, the polyacrylamide column operated at 30°C provided at least two-fold higher resolution for intact ribonuclease B, and showed peaks for glycoforms of prostate specific antigen, although not resolved. PMID:23806357

Zhang, Zhaorui; Wu, Zhen; Wirth, Mary J

2013-08-01

251

Polyacrylamide brush layer for Hydrophilic Interaction Liquid Chromatography of intact glycoproteins  

PubMed Central

A chromatographic column of nonporous silica particles with a bonded phase of linear polyacrylamide chains is evaluated for hydrophilic interaction liquid chromatography (HILIC) of intact glycoproteins. The column is shown to retain glycoproteins significantly more strongly than non-glycoproteins. A particle diameter of 700 nm gives two-fold higher resolution than does a 1.4 ?m particle diameter, and the column efficiency is found to be mostly limited by packing heterogeneity. LCMS is able to resolve the five glycoforms of ribonuclease B and give high quality mass spectra, but there is loss of resolution of the isomers of glycoforms due to the lower amount of TFA. Compared to two leading commercial HILIC columns operated at 60 °C, the polyacrylamide column operated at 30 °C provided at least two-fold higher resolution for intact ribonuclease B, and showed peaks for glycoforms of prostate specific antigen, although not resolved. PMID:23806357

Zhang, Zhaorui; Wu, Zhen; Wirth, Mary J.

2013-01-01

252

Uranium Sorption by Pseudomonas Biomass Immobilized in Radiation Polymerized Polyacrylamide Bio-Beads  

Microsoft Academic Search

A Pseudomonas strain identified as a potent biosorbent of uranium (U) and thorium was immobilized in radiation-induced polyacrylamide matrix for its application in radionuclide containing wastewater treatment. The immobilized biomass exhibited a high U sorption of 202 mg g dry wt. with its optimum at pH 5.0. A good fit of experimental data to the Freundlich model suggested multilayered uranium

S. F. DSOUZA; PINAKI SAR; SUFIA K. KAZY; B. S. KUBAL

2006-01-01

253

Polyacrylamide-based phantoms as tissue substitute in experimental radiation physics  

Microsoft Academic Search

Polyacrylamide-based tissue-equivalent phantoms simulating cortical bone and muscle are described. The equivalency is based upon similar elemental composition and density, and partial similarity in the morphology of bone. Satisfactory results were obtained when the phantoms were tested at low (20 keV) and high (15 MeV) gamma radiation. Applicability of this phantom material to neutron transport is discussed. The material can

L. Wielopolski; M. Maryanski; A. C. Washington; G. Schidlovsky; S. H. Cohn; L. E. Reinstein; A. M. Kalend; A. B. Meek

1985-01-01

254

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

Microsoft Academic Search

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

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

2010-01-01

255

Intrinsic viscosity, surface activity, and flocculation of cationic polyacrylamide modified with fluorinated acrylate  

Microsoft Academic Search

A novel cationic polyacrylamide modified with fluorinated acrylate had been synthesized of acrylamide (AM), methacryloxyethyl\\u000a trimethylammonium chloride (DMC), and 2-(perfluorooctyl)ethyl acrylate (FEA) by free radical micellar copolymerization in\\u000a aqueous solution utilizing cetyl trimethylammonium bromide (CTAB) as the surfactant and potassium persulfate (KPS)\\/sodium\\u000a bisulfite (SBS) as the redox initiator. Some factors affecting synthesis, such as the amount of FEA, CTAB, and

Yang Xiaowu; Shen Yiding; Li Peizhi

2010-01-01

256

Direct voltammetry and electrocatalytic properties of catalase incorporated in polyacrylamide hydrogel films  

Microsoft Academic Search

The direct voltammetry and electrocatalytic properties of catalase (Cat) in polyacrylamide (PAM) hydrogel films cast on pyrolytic graphite (PG) electrodes were investigated. Cat-PAM film electrodes showed a pair of well-defined and nearly reversible cyclic voltammetry peaks for Cat Fe(III)\\/Fe(II) redox couples at approximately ?0.46 V vs. SCE in pH 7.0 buffers. The electron transfer between catalase and PG electrodes was

Haiyun Lu; Zhen Li; Naifei Hu

2003-01-01

257

Modeling chemoresponsive polymer gels.  

PubMed

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

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

2014-01-01

258

Responsive Gel-Gel Phase Transitions in Artificially Engineered Protein Hydrogels  

NASA Astrophysics Data System (ADS)

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.

Olsen, B. D.

2012-02-01

259

Direct transformation of benzilic amines to carbonyls using polyacrylamide-bound tungstate under phase-transfer catalysis conditions  

Microsoft Academic Search

A recyclable catalytic system under heterogeneous phase-transfer catalysis conditions was designed by using polyacrylamide-bound tungstate. A convenient method for the oxidative direct transformation of benzilic amines to carbonyls with hydrogen peroxide was then developed.

Hiromi Hamamoto; Yachiyo Suzuki; Hideyo Takahashi; Shiro Ikegami

2007-01-01

260

Native American medicine.  

PubMed

This article summarizes common principles, practices, and ethics of Native American healing, the traditional medicine of North America. Native American healing, spirituality, culture, and, in modern times, political, social, and economic concerns are closely intertwined. Intuition and spiritual awareness are a healer's most essential diagnostic tools. Therapeutic methods include prayer, music, ritual purification, herbalism, massage, ceremony, and personal innovations of individual healers. A community of friends, family, and helpers often participate in the healing intervention and help to alleviate the alienation caused by disease. A healthy patient has a healthy relationship with his or her community and, ultimately, with the greater community of nature known as "All Relations." The goal of Native American healing is to find wholeness, balance, harmony, beauty, and meaning. "Healing," making whole, is as important as curing disease; at times they are identical. PMID:9810067

Cohen, K

1998-11-01

261

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.

262

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

PubMed Central

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

2013-01-01

263

In-phantom dosimetry for BNCT with Fricke and normoxic-polymer gels  

NASA Astrophysics Data System (ADS)

Measurements of in-phantom dose distributions and images are important for Boron Neutron Capture Therapy treatment planning. The method for spatial determination of absorbed doses in thermal or epithermal neutron fields, based on Fricke-xylenol-orange-infused gel dosimeters in form of layers, has revealed to be very reliable, as gel layer dosimeters give the possibility of obtaining spatial dose distributions and measurements of each dose contribution in neutron fields, by means of a properly studied procedure. Quite recently, BNCT has been applied to treat liver metastases; in this work the results of in-phantom dosimetry for explanted liver in BNCT treatments are described. Moreover, polyacrylamide gel (PAG) dosimeters in which a polymerization process appears as a consequence of absorbed dose, have been recently tested, because of their characteristic absence of diffusion. In fact, due to the diffusion of ferric ions, Fricke-gel dosimeters require prompt analysis after exposure to avoid spatial information loss. In this work the preliminary results of a study about the reliability of polymer gel in BNCT dosimetry are also discussed. Gel layers have been irradiated in a phantom exposed in the thermal column of the TRIGA MARK II reactor (Pavia). The results obtained with the two kinds of gel dosimeter have been compared.

Gambarini, G.; Agosteo, S.; Carrara, M.; Gay, S.; Mariani, M.; Pirola, L.; Vanossi, E.

2006-05-01

264

Agarose Gel Demos  

NSDL National Science Digital Library

This video, presented by WGBH, is a great overview of how to prepare Agarose gel for electrophoresis. The video goes in-depth with the finer points including how to insert the pipette as to not disturb the gel and get the best results. This video would be useful for anyone in biochemistry or molecular biology fields. This video would also be helpful for instructors looking to provide their students with an overview on how to prepare Agarose gel. Educators will also find a background essay, discussion questions, and standards alignment for the material.

2010-09-15

265

Native plant diversity increases herbivory to non-natives.  

PubMed

There is often an inverse relationship between the diversity of a plant community and the invasibility of that community by non-native plants. Native herbivores that colonize novel plants may contribute to diversity-invasibility relationships by limiting the relative success of non-native plants. Here, we show that, in large collections of non-native oak trees at sites across the USA, non-native oaks introduced to regions with greater oak species richness accumulated greater leaf damage than in regions with low oak richness. Underlying this trend was the ability of herbivores to exploit non-native plants that were close relatives to their native host. In diverse oak communities, non-native trees were on average more closely related to native trees and received greater leaf damage than those in depauperate oak communities. Because insect herbivores colonize non-native plants that are similar to their native hosts, in communities with greater native plant diversity, non-natives experience greater herbivory. PMID:25232143

Pearse, Ian S; Hipp, Andrew L

2014-11-01

266

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...

267

Native American Case Studies  

NSDL National Science Digital Library

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.

College, The E.; College, Northwest I.; College, Salish K.; College, Grays H.

268

Native Wisdom on Belonging.  

ERIC Educational Resources Information Center

Introduces the conceptual background of a model of youth development that utilizes the principles of the Native-American Circle of Courage. Discusses the four principles of the Circle of Courage: belonging, mastery, independence, and generosity. Discusses the development of the model and the life of the artist who developed that artwork for the…

Brokenleg, Martin

1998-01-01

269

Native American Literature.  

ERIC Educational Resources Information Center

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…

Porter, C. Fayne; And Others

270

Native American Cultural Groups.  

ERIC Educational Resources Information Center

Part of a larger report on the Four Directions Project, an American Indian technology innovation project, this section includes 13 "pathfinders" to locating information on Native American and other indigenous cultural groups. The pathfinders were designed by students in the Graduate School of Library and Information Science at the University of…

Roy, Loriene, Comp.

271

The Native American Speaks.  

ERIC Educational Resources Information Center

This publication is the product of several workshops and is aimed at multi-ethnic integration of teacher attitudes, curriculum content, and teaching techniques. The 7 articles and 3 bibliographies, contributed by Native American consultants, emphasize recognition and alteration of bias in teacher attitudes, curriculum content, and teaching…

Bromberg, Walter; And Others

272

Exploring Native American Symbolism.  

ERIC Educational Resources Information Center

This paper described the events and results of a workshop on Native American symbolism presented to educators and held in Kansas City, Missouri. The presenter maintained that some of the most crucial problems facing U.S. educators and students are caused by racial misunderstandings, and that the universality of artistic expression can be a vehicle…

Dufrene, Phoebe

273

Native American Resource Book.  

ERIC Educational Resources Information Center

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,…

Spears, Carl D., Comp.; And Others

274

Native American Health  

MedlinePLUS

... racial or ethnic group has specific health concerns. Differences in the health of groups can result from: Genetics Environmental factors Access to care Cultural factors On this page, you'll find links to health issues that affect Native-Americans.

275

Native American Nuances.  

ERIC Educational Resources Information Center

Continues a series of articles on art projects incorporating the use of alphabetical or numerical symbols. Describes a project in which third-grade students incorporated Native American art motifs and symbols into large-scale paintings of letters of the alphabet. Notes discoveries made by students in the course of their projects. (DSK)

Evensen, Helen

1998-01-01

276

Symbolicity Among Native Americans.  

ERIC Educational Resources Information Center

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…

Hill, L. Brooks; Lujan, Philip

277

Conformance Improvement Using Gels  

SciTech Connect

This research project had two objectives. The first objective was to identify gel compositions and conditions that substantially reduce flow through fractures that allow direct channeling between wells, while leaving secondary fractures open so that high fluid injection and production rates can be maintained. The second objective was to optimize treatments in fractured production wells, where the gel must reduce permeability to water much more than that to oil.

Seright, Randall S.; Schrader, Richard; II Hagstrom, John; Wang, Ying; Al-Dahfeeri, Abdullah; Gary, Raven; Marin; Amaury; Lindquist, Brent

2002-09-26

278

Preparation of chitosan gel  

NASA Astrophysics Data System (ADS)

Aerogel conditioning of the chitosan makes it possible to prepare porous solids of significant specific surface. The increase in the chitosan concentration or the degree of acetylation decreases the specific surface of the synthesized chitosan gel. Whereas drying with supercritical CO2 more effectively makes it possible to preserve the volume of the spheres of gel and to have a more significant specific surface in comparison with evaporative drying.

Moussaoui, Y.; Mnasri, N.; Elaloui, E.; Ben Salem, R.; Lagerge, S.; de Menorval, L. C.

2012-06-01

279

Native Peoples-Native Homelands Climate Change Workshop: Lessons Learned  

NASA Astrophysics Data System (ADS)

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.

Maynard, N. G.

2003-12-01

280

Native Peoples-Native Homelands Climate Change Workshop: Lessons Learned  

Microsoft Academic Search

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

N. G. Maynard

2003-01-01

281

[Native and renatured oligomer-dependent epitopes of intracellular influenza virus nucleocapsid protein].  

PubMed

Intracellular NP oligomers have been shown to react with some anti-NP monoclonal antibodies (mAbs) in radio-immnoprecipitation, immunoblotting, and dot immunoassay. Soluble NP monomers obtained after thermal dissociation of NP oligomers are not recognized by mAbs unlike the NP monomers whose concentration increased by about 100-fold due to transfer to the nitrocellulose membrane after polyacrylamide gel electrophoresis. The findings demonstrated that in the intact NP oligomers there were epitopes determined by their quaternary structure. These oligomer-dependent epitopes may be renaturated in vitro under the conditions allowing for a concentration-dependent NP-NP association. PMID:18318130

Semenova, N P; Prokudina, E N; Chumakov, V M; Grigor'eva, T A; Stitz, L

2008-01-01

282

Monopyrrolotetrathiafulvalene-succinamide conjugates and their TCNQ charge transfer complex based supramolecular gels with multiple stimulus responsiveness.  

PubMed

A series of monopyrrolotetrathiafulvalene-succinamide conjugates and their 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) charge transfer (CT) complexes have been synthesized and investigated as new low-molecular mass organogelators. The gelation capability of these conjugates is highly dependent on the length of the alkyl chain of the terminal amide. Thus, only the short alkyl chain derivatives and could efficiently gelate cyclohexane and methylcyclohexane (MCH). Surprisingly, these gelators react with TCNQ to form stable CT complex gels in both cyclohexane and MCH. The FE-SEM images of the native gels reveal the characteristic gelation morphologies of microporous or fibrous structures, whereas the morphologies of CT complex gels show the fibrillar and globular aggregates in cyclohexane and MCH, respectively. SAXS study of the native gel and the CT complex gel of in cyclohexane suggests that the molecules maintain rectangular and hexagonal columnar molecular packing models in the gel phase, respectively. The native gels undergo a reversible gel-sol phase transition upon exposure to external stimuli, such as temperature and chemical oxidation/reduction. Alternatively, the corresponding CT complex gels exhibit a complicated response to external stimuli. Chemical oxidation by I2 results in the destruction of the gel state. However, neither Fe(3+) nor Cu(2+) can induce the collapse of the gel phase. Interestingly, all the gels show an irreversible gel-sol transition on successively triggering with trifluoroacetic acid and triethylamine. The reformation of the gel from the sol state is achieved just by the addition of water, showing the phase-selective gelation of the solvents from their mixtures with water. PMID:25069409

Liu, Yucun; Zheng, Ningjuan; Chen, Tie; Jin, Longyi; Yin, Bingzhu

2014-09-21

283

Polyacrylamide-hydroxyapatite composite: Preparation, characterization and adsorptive features for uranium and thorium  

SciTech Connect

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 UO{sub 2}{sup 2+} and Th{sup 4+}. 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. Th{sup 4+} 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. - Graphical abstract: SEM images of hydroxyapatite (HAP) and polyacrylamide-hydroxyapatite (PAAm-HAP), and the adsorption isotherms for Uranium and Thorium. Highlights: Black-Right-Pointing-Pointer Composite of PAAm-HAP was synthesized from hydroxyapatite and polyacrylamide. Black-Right-Pointing-Pointer The materials were characterized by BET, FT-IR, XRD, SEM, TGA and PZC analysis. Black-Right-Pointing-Pointer HAP and PAAm-HAP had high sorption capacity and very rapid uptake for UO{sub 2}{sup 2+} and Th{sup 4+}. Black-Right-Pointing-Pointer Super porous PAAm was obtained from PAAm-HAP after its removal of HAP content. Black-Right-Pointing-Pointer The composite is potential for deposition of U, Th and its associate radionuclides.

Baybas, Demet, E-mail: dbaybas@cumhuriyet.edu.tr [Cumhuriyet University, Faculty of Science, Department of Chemistry, Kayseri, Sivas 58140 (Turkey)] [Cumhuriyet University, Faculty of Science, Department of Chemistry, Kayseri, Sivas 58140 (Turkey); Ulusoy, Ulvi, E-mail: ulusoy@cumhuriyet.edu.tr [Cumhuriyet University, Faculty of Science, Department of Chemistry, Kayseri, Sivas 58140 (Turkey)] [Cumhuriyet University, Faculty of Science, Department of Chemistry, Kayseri, Sivas 58140 (Turkey)

2012-10-15

284

Controlling tailwater sediment and phosphorus concentrations with polyacrylamide in the Imperial Valley, California.  

PubMed

External loading of phosphorus (P) from agricultural surface discharge (tailwater) is the main cause of excessive algae growth and the eutrophication of the Salton Sea, California. Continuous polyacrylamide (PAM) applications to agricultural irrigation water inflows were evaluated as a means of reducing sediment and P in tailwater. Zero (control) and 1 mg L(-1) PAM (PAM1) treatments were compared at 17 Imperial Valley field sites. Five and 10 mg L(-1) PAM treatments (PAM5, PAM10) were conducted at one site. The particulate phosphorus (Pp) fraction was determined as the difference between total phosphorus (Pt) and the soluble phosphorus (Ps) fraction. We observed 73, 82, and 98% turbidity reduction with PAM1, PAM5, and PAM10 treatments. Although eight field sites had control tailwater sediment concentrations above the New River total maximum daily loads (TMDL), all but one were made compliant during their paired PAM1 treatments. While PAM1 and PAM10 reduced tail water Pp by 31 and 78%, none of the treatments tested reduced Ps. This may have been caused by high irrigation water Na concentrations which would reduce Ca adsorption and Ca-phosphate bridging on the PAM. The PAM1 treatments resulted in <0.5 mg L(-1) drain water polyacrylamide concentrations 1.6 km downstream of PAM addition, while PAM5 and PAM10 treatments produced > 2 mg L(-1) drain water polyacrylamide concentrations. We concluded that, although PAM practically eliminates Imperial Valley tailwater sediment loads, it does not effectively reduce tailwater Ps, the P fraction most responsible for the eutrophication of the Salton Sea. PMID:16738392

Goodson, Christopher C; Schwartz, Gregory; Amrhein, Christopher

2006-01-01

285

Identification of iron Superoxide dismutase and a copper\\/zinc Superoxide dismutase enzyme activity within the marine cyanobacterium Synechococcus sp. WH 7803  

Microsoft Academic Search

Three constitutive forms of Superoxide dismutase activity have been demonstrated in the cyanobacterial marine picoplankter Synechococcus sp. WH 7803 using polyacrylamide gel activity staining techniques. A protein which gave a positive non-haem iron stain on native polyacrylamide gels exhibited N-terminal similarity to both the iron Superoxide dismutase and the manganese Superoxide dismutase of Escherichia coli. The metal prosthetic group of

Helen E Chadd; Julie Newman; Nicholas H Mann; Noel G Carr

1996-01-01

286

A novel polymeric flocculant based on polyacrylamide grafted inulin: aqueous microwave assisted synthesis.  

PubMed

Polyacrylamide grafted inulin (In-g-PAM) was synthesized via aqueous microwave assisted method (using ceric ammonium nitrate in synergism with microwave in aqueous medium). The intended grafting of the PAM chains on polysaccharide backbone was confirmed through standard physicochemical characterization techniques, namely intrinsic viscosity measurement, Fourier transform infrared (FTIR) spectroscopy, elemental analysis (C, H, N and O), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) studies. Flocculation efficacy of various grades of synthesized grafted product was studied in coal fines suspension, in relation to inulin (parent polysaccharide). This was done utilizing jar test and settling test procedure, towards possible application as a flocculant for coal washery effluents. PMID:24274474

Rahul, Rahul; Jha, Usha; Sen, Gautam; Mishra, Sumit

2014-01-01

287

Ceric ion initiated synthesis of polyacrylamide grafted oatmeal: Its application as flocculant for wastewater treatment.  

PubMed

Polyacrylamide grafted oatmeal (OAT-g-PAM) was synthesized by conventional method. The grafting of the PAM chains on the biomaterial backbone was confirmed through intrinsic viscosity study, FTIR spectroscopy, elemental analysis (C, H, N, S and O), SEM morphology and TGA study. The intrinsic viscosity of oatmeal appreciably improved on grafting of PAM chains, thus resulting grafted product with potential application as superior viscosifier. Further, flocculation efficacy of the graft copolymer was studied in coal fine suspension, kaolin suspension, iron-ore suspension and then in municipal wastewater through 'jar test' procedure. PMID:23499093

Bharti, Srijita; Mishra, Sumit; Sen, Gautam

2013-04-01

288

ALASKAN NATIVE SECONDARY SCHOOL DROPOUTS.  

ERIC Educational Resources Information Center

DETERMINATIONS WERE MADE OF THE DROPOUT RATE AMONG NATIVE ALASKAN HIGH SCHOOL STUDENTS AND THE VARIOUS REASONS FOR FAILURE TO FINISH SCHOOL. THE STUDY SAMPLE WAS DRAWN FROM NINE ALASKAN HIGH SCHOOLS WITH OVER ONE-HALF NATIVE STUDENT ENROLLEES. NATIVES WERE DEFINED AS PERSONS BEING ONE-FOURTH OR MORE ESKIMO, INDIAN, OR ALEUT. APPROXIMATELY 1,200…

RAY, CHARLES K.; AND OTHERS

289

Who Stole Native American Studies?  

ERIC Educational Resources Information Center

Native American Studies has failed to develop into an academic discipline because of the continued influence of postcolonial theories, attempts to discredit Native American scholars, politically determined research agendas, and the ideology of the "New Historicism." Native American Studies must seek autonomy from other opportunistic epistemologies…

Cook-Lynn, Elizabeth

1997-01-01

290

Readings in Canadian Native Studies.  

ERIC Educational Resources Information Center

After noting that Canadian and American scholars virtually ignore each other in the field of Native Studies, this paper summarizes sources of information for anyone interested in Canadian Native studies. The introduction mentions university programs and departments, newspaper coverage of Native issues, number of books and monographs published per…

Price, John A.

1986-01-01

291

The roles of disulphide and non-covalent bonding in the functional properties of heat-induced whey protein gels.  

PubMed

Heat-induced gelation (80 degrees C, 30 min or 85 degrees C, 60 min) of whey protein concentrate (WPC) solutions was studied using transmission electron microscopy (TEM), dynamic rheology and polyacrylamide gel electrophoresis (PAGE). The WPC solutions (150 g/kg, pH 6.9) were prepared by dispersing WPC powder in water (control), 10 g/kg sodium dodecyl sulphate (SDS) solution or 10 mM-dithiothreitol (DTT) solution. The WPC gels containing SDS were more translucent than the control gels, which were slightly more translucent than the gels containing DTT. TEM analyses showed that the SDS-gels had finer aggregate structure (approximately equal to 10 nm) than the control gels (approximately equal to 100 nm), whereas the DTT-gels had a more particulate structure (approximately equal to 200 to 300 nm). Dynamic rheology measurements showed that the control WPC gels had storage modulus (G) values (approximately equal to 13,500 Pa) that were approximately equal to 25 times higher than those of the SDS-gels (approximately equal to 550 Pa) and less than half those of the DTT-gels after cooling. Compression tests showed that the DTT-gels were more rigid and more brittle than the control gels, whereas the SDS-gels were softer and more rubbery than either the control gels or the DTT-gels. PAGE analyses of WPC gel samples revealed that the control WPC solutions heated at 85 degrees C for 10 min contained both disulphide bonds and non-covalent linkages. In both the SDS-solutions and the DTT-solutions, the denatured whey protein molecules were in the form of monomers or small aggregates. It is likely that, on more extended heating, more disulphide linkages were formed in the SDS-gels whereas more hydrophobic aggregates were formed in the DTT-gels. These results demonstrate that the properties of heat-induced WPC gels are strongly influenced by non-covalent bonding. Intermolecular disulphide bonds appeared to give the rubbery nature of heat-induced WPC gels whereas non-covalent bonds their rigidity and brittle texture. PMID:15354580

Havea, Palatasa; Carr, Alistair J; Creamer, Lawrence K

2004-08-01

292

Alaska Native Knowledge Network  

NSDL National Science Digital Library

The Alaska Native Knowledge Network (ANKN) was established to serve as "a resource for compiling and exchanging information related to Alaska Native knowledge systems and ways of knowing." To achieve this goal, the website brings together publications, information about academic programs, curriculum resources, and a calendar of events. In the Curriculum Resources area, visitors can look over lesson plans, fact sheets, and classroom activities that weave together indigenous and Western knowledge systems. Moving on, the Publications area contains links to print publications for sale and a range of free titles, including "Guidelines for Culturally Responsible School Boards" and "Guidelines for Respecting Cultural Knowledge." Also, visitors should take a look at the Announcements area for updates about relevant training programs, workshops, and conferences.

293

A model of ideal elastomeric gels for polyelectrolyte gels  

E-print Network

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

Suo, Zhigang

294

Effects of polyacrylamide, biopolymer, and biochar on decomposition of soil organic matter and 14C-labeled plant residues as determined by enzyme activities  

NASA Astrophysics Data System (ADS)

Application of polymers for the improvement of aggregate structure and reduction of soil erosion may alter the availability and decomposition of plant residues. In this study, we assessed the effects of anionic polyacrylamide (PAM), synthesized biopolymer (BP), and biochar (BC) on the decomposition of 14C-labeled maize residue in sandy and sandy loam soils. Specifically, PAM and BP with or without 14C-labeled plant residue were applied at 400 kg ha-1, whereas BC was applied at 5000 kg ha-1, after which the soils were incubated for 80 days at 22 oC. Initially, plant residue decomposition was much higher in untreated sandy loam soil than in sandy soil. Nevertheless, the stimulating effects of BP and BC on the decomposition of plant residue were more pronounced in sandy soil, where it accounted for 13.4% and 23.4% of 14C input, respectively, whereas in sandy loam soil, the acceleration of plant residue decomposition by BP and BC did not exceed 2.6% and 14.1%, respectively, compared to untreated soil with plant residue. The stimulating effects of BP and BC on the decomposition of plant residue were confirmed based on activities of ?-cellobiohydrolase, ?-glucosidase, and chitinase in both soils. In contrast to BC and BP, PAM did not increase the decomposition of native or added C in both soils.

Mahmoud Awad, Yasser; Ok, Young Sik; Kuzyakov, Yakov

2014-05-01

295

Hydrolyzed polyacrylamide grafted carboxymethylxyloglucan based microbeads for pH responsive drug delivery.  

PubMed

The present study investigates the pharmaceutical application of hydrolyzed polyacrylamide grafted carboxymethylxyloglucan (HPam-g-CMXG), as promising polymeric material for the development of pH responsive microbeads. The graft copolymer was synthesized by conventional free radical polymerization method and saponified to enhance its functionality and characterized. An acute oral toxicity study ensured the bio-safety of developed copolymer for clinical application. Various batches of pH responsive spherical microbeads were developed and evaluated for the effect of process parameters on their overall performance. Result of in vitro drug release study (USP Type-II, paddle method) carried out in two different pH media (pH 1.2 and pH 7.4) showed a triphasic drug release pattern in all the formulations. Both the drug release and swelling of microbeads were significantly higher in simulated intestinal (alkaline) pH compared to simulated gastric (acidic) pH and this nature is desirable for targeted drug delivery. A strong correlation was observed between the process parameters and matrix composition and it directly influenced the drug transport mechanism. In conclusion, the hydrolyzed polyacrylamide grafted carboxymethylxyloglucan holds an immense potential to be explored pharmaceutically as new matrix material for the design of targeted drug delivery system. PMID:24632345

Setty, C Mallikarjuna; Deshmukh, Anand S; Badiger, Aravind M

2014-06-01

296

Separation of rainbow trout (Salmo gairdneri) growth hormone by gel electrophoresis.  

PubMed

Pituitaries from immature (n = 12) and mature female (n = 15) rainbow trout were cultured separately in vitro and subjected to polyacrylamide gel electrophoresis. Four protein bands were identified from the immature rainbow trout and three from the adults. The material from the immature trout was used to raise antisera. Three of the bands, including those with the highest (0.74) and lowest (0.27) Rf values, produced antibodies. Immunocytochemical studies revealed that all of the antisera bound strongly to the growth hormone cells and weakly, if at all, to prolactin cells in pituitary sections from rainbow trout. PMID:2127033

Skarphedinsson, O; Power, D M; Ingleton, P M

1990-12-01

297

Swelling of Olympic Gels  

NASA Astrophysics Data System (ADS)

The swelling equilibrium of Olympic gels, which are composed of entangled cyclic polymers, is studied by Monte Carlo simulations. In contrast to chemically cross-linked polymer networks, we observe that Olympic gels made of chains with a larger degree of polymerization, N, exhibit a smaller equilibrium swelling degree, Q?N-0.28?0-0.72, at the same polymer volume fraction ?0 at network preparation. This observation is explained by a desinterspersion (reorganization with release of nontrapped entanglements) process of overlapping nonconcatenated rings upon swelling.

Lang, M.; Fischer, J.; Werner, M.; Sommer, J.-U.

2014-06-01

298

Native protein complexes in the cytoplasm of red blood cells.  

PubMed

Despite decades of advancements, the investigation of the red blood cell (RBC) cytosolic proteome still represents a challenging task because of the overwhelming abundance of hemoglobin. Besides, the separation method is one of the main limiting factors when investigating protein complexes. In this study, we performed for the first time a 2D-clear native (CN)-SDS-PAGE followed by mass spectrometry-based identification to screen multiprotein complexes (MCPs) in the cytosol of human RBCs. Upstream to 2D-CN-SDS-PAGE, we applied a recently developed native pre-enrichment strategy that allows discriminating and separately collecting three distinct fractions, one of which is highly enriched for hemoglobin. Such prefractionation strategy is conservative, in that it makes soluble native-complex analyses amenable without loss of biological information. Because of the resolution of native gel electrophoresis techniques, we could observe and describe 55 potential hetero-oligomeric MPCs from the RBC native cytosolic proteome, among which ultratetrameric hemoglobin. The detected protein complexes were characterized by proteins mainly involved in oxygen transport, antioxidant responses, metabolism, and protein degradation cascades, in agreement with recent in silico models. Metabolic enzyme oligomers also interacted with complexes of proteins involved in oxidative stress responses, thus suggesting a functional relationship between metabolic modulation and antioxidant defenses. PMID:23781972

Pallotta, Valeria; D'Alessandro, Angelo; Rinalducci, Sara; Zolla, Lello

2013-07-01

299

Native American geometry  

NSDL National Science Digital Library

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)

2007-12-12

300

Running an Agarose Gel  

NSDL National Science Digital Library

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.

Hinkley, Craig

2013-06-17

301

Preparing an Agarose Gel  

NSDL National Science Digital Library

This video from CUNY Kingsborough Community College describes the technique of preparing 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 3:10.

Shun Ho, Ivan

2013-06-25

302

Pouring an Agarose Gel  

NSDL National Science Digital Library

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.

Hinkley, Craig

2013-06-26

303

Transdermal delivery of paeonol using cubic gel and microemulsion gel  

PubMed Central

Background The aim of this study was to develop new systems for transdermal delivery of paeonol, in particular microemulsion gel and cubic gel formulations. Methods Various microemulsion vehicles were prepared using isopropyl myristate as an oil phase, polyoxyethylated castor oil (Cremophor® EL) as a surfactant, and polyethylene glycol 400 as a cosurfactant. In the optimum microemulsion gel formulation, carbomer 940 was selected as the gel matrix, and consisted of 1% paeonol, 4% isopropyl myristate, 28% Cremophor EL/polyethylene glycol 400 (1:1), and 67% water. The cubic gel was prepared containing 3% paeonol, 30% water, and 67% glyceryl monooleate. Results A skin permeability test using excised rat skins indicated that both the cubic gel and microemulsion gel formulations had higher permeability than did the paeonol solution. An in vivo pharmacokinetic study done in rats showed that the relative bioavailability of the cubic gel and microemulsion gel was enhanced by about 1.51-fold and 1.28-fold, respectively, compared with orally administered paeonol suspension. Conclusion Both the cubic gel and microemulsion gel formulations are promising delivery systems to enhance the skin permeability of paeonol, in particular the cubic gel. PMID:21904450

Luo, Maofu; Shen, Qi; Chen, Jinjin

2011-01-01

304

Physico-chemical characteristics of polyacrylamide solutions after mechanical degradation through a porous medium  

SciTech Connect

Mechanical degradation of polymer solutions is an important problem which has to be assessed before injection into a reservoir. The main consequence is a viscosity loss due to macromolecules breakage which can strongly reduce the polymer solution effectiveness in controlling the water mobility inside the reservoir. Flow experiments have been performed by recirculating hydrolyzed polyacrylamide solutions through a small pack of sand particles. Polymer characteristics determined by viscometric and light scattering measurements have been analyzed before and after injection at various flow rates. A normalized rate of degradation was defined by comparing the initial and final values of the intrinsic viscosity of solutions. The parameters investigated were: polymer concentration, molecular weight, concentration and nature of electrolytes.

Noiek, C.; Delaplace, P. [Inst. Francais du Petrole, Rueil-Malmaison (France); Muller, G. [Faculte des Sciences, Mont St. Aignan (France)

1995-11-01

305

The electro-responsive drug delivery from salicylic acid -loaded polyacrylamide hydrogels  

NASA Astrophysics Data System (ADS)

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.

Niamlang, Sumonman; Sirivat, Anuvat

2007-03-01

306

Direct capture of lactoferrin from cheese whey on supermacroporous column of polyacrylamide cryogel with copper ions.  

PubMed

Lactoferrin is a protein that is present in cheese whey (a waste product from the dairy industry) and has several biological activities. However, its production from whey must have a high yield and low cost for industrial applications. As such, this study reports the use of polyacrylamide cryogel, loaded with Cu(2+) (through the bond with iminodiacetic acid (IDA)), as an adsorbent for the chromatographic process to capture lactoferrin whey. Ultrafiltered cheese whey was passed through the cryogel-IDA-Cu(2+) system. The eluates were subjected to analysis of total protein, SDS-PAGE and size exclusion chromatography. The results showed an axial dispersion coefficients, at different superficial velocities of liquid, in a range of 10(-6)-10(-5)m(2)/s. The cryogel demonstrated good hydraulic permeability (4.7086×10(-13)m(2)) and a porosity of approximately 78.2%. The IDA-Cu(2+) cryogel system was also able to capture lactoferrin in high purity. PMID:24518347

Carvalho, B M A; Carvalho, L M; Silva, W F; Minim, L A; Soares, A M; Carvalho, G G P; da Silva, S L

2014-07-01

307

The Use of Polyacrylamide as a Selective Depressant in the Separation of Chalcopyrite and Galena  

NASA Astrophysics Data System (ADS)

High molecular weight polyacrylamide (PAM) was tested as a potential selective depressant in the differential flotation separation of galena and chalcopyrite using potassium ethyl xanthate (KEX) as a collector. In single mineral flotation, PAM depressed chalcopyrite while galena was floatable. Mechanism study indicated that PAM could adsorb on galena through hydrogen bonding, and on chalcopyrite through hydrogen bonding as well as ammonium-copper complexation. KEX could only break up the galena-PAM bonding. It is the combined use of PAM and KEX that caused the selectivity. In mineral mixture flotation, galena and chalcopyrite could be separated by PAM and KEX only after EDTA treatment of the mineral mixtures. Time of flight secondary ion mass spectrometric (ToF-SIMS) measurements indicated that when galena and chalcopyrite were present together in the suspension, PAM adsorbed on both galena and chalcopyrite. However, after prior treatment of the mineral mixture by EDTA, PAM mainly adsorbed on chalcopyrite.

Wang, Lei

308

Stabilization of insulin against agitation-induced aggregation by the GMO cubic phase gel.  

PubMed

The main objective of the study was to evaluate if the liquid crystalline cubic phase gel of glyceryl monooleate (GMO) protects insulin from agitation induced aggregation. The aggregation of Humulin(R), Regular Iletin I(R) and Regular Iletin II(R), in cubic phase GMO gels at 30 U/g of gel was compared with that in PBS at 100 oscillations/min at 37 degrees C using optical density at 600 nm. The effect of agitation on the secondary structure of insulin in solution and in the gels was determined with circular dichroism (CD) spectroscopy, and the time course of aggregation was also followed by HPLC. A sigmoidal increase in optical density of solution with time indicated formation of increasing amounts of insoluble insulin aggregates. However, in the gels, optical density values stayed at, or around, the initial optical density value, comparable with that of a blank gel suggesting that insulin had not aggregated in the gel. CD spectroscopy of the soluble insulin showed a total loss of native conformation upon aggregation of insulin in solution. In contrast, CD spectra of insulin in the gel were unaltered suggesting protection from aggregation during agitation. Furthermore, agitation of insulin in gels for a duration as long as 2 months at 37 degrees C, had very little adverse effect on the native conformation of insulin, as indicated by the lack of a significant change in its CD spectrum. Therefore, the cubic phase gel was indeed able to protect insulin from agitation-induced aggregation and subsequent precipitation. Although the majority of insulin in solution appeared to have aggregated and precipitated after 8 days by UV and CD spectroscopy, RP-HPLC results indicated the presence of some soluble aggregates of insulin. In summary, the liquid crystalline cubic phase gel of GMO protects peptides, like insulin, from agitation-induced aggregation. PMID:10556740

Sadhale, Y; Shah, J C

1999-11-25

309

Introduced brown trout alter native acanthocephalan infections in native fish.  

PubMed

1. Native parasite acquisition provides introduced species with the potential to modify native host-parasite dynamics by acting as parasite reservoirs (with the 'spillback' of infection increasing the parasite burdens of native hosts) or sinks (with the 'dilution' of infection decreasing the parasite burdens of native hosts) of infection. 2. In New Zealand, negative correlations between the presence of introduced brown trout (Salmo trutta) and native parasite burdens of the native roundhead galaxias (Galaxias anomalus) have been observed, suggesting that parasite dilution is occurring. 3. We used a multiple-scale approach combining field observations, experimental infections and dynamic population modelling to investigate whether native Acanthocephalus galaxii acquisition by brown trout alters host-parasite dynamics in native roundhead galaxias. 4. Field observations demonstrated higher infection intensity in introduced trout than in native galaxias, but only small, immature A. galaxii were present in trout. Experimental infections also demonstrated that A. galaxii does not mature in trout, although parasite establishment and initial growth were similar in the two hosts. Taken together, these results support the hypothesis that trout may serve as an infection sink for the native parasite. 5. However, dynamic population modelling predicts that A. galaxii infections in native galaxias should at most only be slightly reduced by dilution in the presence of trout. Rather, model exploration indicates parasite densities in galaxias are highly sensitive to galaxias predation on infected amphipods, and to relative abundances of galaxias and trout. Hence, trout presence may instead reduce parasite burdens in galaxias by either reducing galaxias density or by altering galaxias foraging behaviour. PMID:21426342

Paterson, Rachel A; Townsend, Colin R; Poulin, Robert; Tompkins, Daniel M

2011-09-01

310

Polyacrylamide-chitosan hydrogels: in vitro biocompatibility and sustained antibiotic release studies.  

PubMed

Controlled drug delivery is gaining importance over the conventional methods of drug administration because of its inherent benefits. Self-regulated release from the delivery vehicle may enhance drug potency with a sustained action. The present study describes a novel hydrogel blend of polyacrylamide with chitosan for controlled delivery of antibiotics. Hydrogel was synthesized by cross-linking acrylamide-chitosan mixture (8:2 v/v) with N,N' methylene bisacrylamide. Hydrogel was characterized for surface morphology, hydrophilicity, pH-dependent swelling properties, cytotoxicity, and control release properties. Scanning electron microscopy (SEM) revealed the macroporous surface morphology of the matrix with average pore size at 104 +/- 7.61 mu. Hydrogel was found to be highly hydrophilic as assessed by octane contact angle (154.5 + 0.572) measurement. Hydrogel showed no cytotoxic effects on NIH3T3 and HeLa cells up to 40% of extract concentrations as determined by MTT and neutral red assay. This showed hydrogel biocompatibility and thus absence of deleterious effects of the hydrogel on cell viability and functionality. Hydrogels did not show any pH-dependent swelling profile, and they swelled considerably to achieve a swelling ratio of approximately 16.0 at the end of 24 hr. Amoxicillin was incorporated in the hydrogel matrix as a candidate antibiotic for release studies. In vitro release studies of amoxicillin revealed the sustained nature of delivery and matrix released 56.47 + 1.12% and 77.096 + 1.72% of amoxicillin at the end of 24 and 75 hr, respectively. Although in vivo studies are awaited, the present study provides enough documentation to consider polyacrylamide-chiotsan hydrogel as a possible candidate for controlled delivery of antibiotics. PMID:10892406

Risbud, M V; Bhonde, R R

2000-01-01

311

Fabrication of 3D-networks of native starch and their application to produce porous inorganic oxide networks through a supercritical route  

Microsoft Academic Search

Herein an effective method for fabrication of three dimensional networks of starch is presented. In this method, the native starch was dissolved in hot water to form solution, resulting in the formation of starch gel after cooled to room temperature. Then the water in the starch gel was exchanged by ethanol, followed by drying with supercritical (SC) CO2 extraction, the

Zhenjiang Miao; Kunlun Ding; Tianbin Wu; Zhimin Liu; Buxing Han; Guimin An; Shiding Miao; Guanying Yang

2008-01-01

312

Traditional West Coast Native Medicine  

PubMed Central

An important part of the complex culture of the Native people of Canada's Pacific coast is the traditional system of medicine each culture has developed. Population loss from epidemics and the influence of dominant European cultures has resulted in loss of many aspects of traditional medicine. Although some Native practices are potentially hazardous, continuation of traditional approaches to illness remains an important part of health care for many Native people. The use of “devil's club” plant by the Haida people illustrates that Native medicine has both spiritual and physical properties. Modern family practice shares many important foundations with traditional healing systems. PMID:21253031

Deagle, George

1988-01-01

313

Two-dimensional Gel Electrophoresis (2DE)  

NASA Astrophysics Data System (ADS)

The chemical compounds, which are present in the environment, increasingly cause bad effects on health. The most serious effects are tumors and various mutations at the cellular level. Such compounds, from the analytical point of view, can serve the function of biomarkers, constituting measurable changes in the organism's cells and biochemical processes occurring therein. The challenge of the twenty-first century is therefore searching for effective and reliable methods of identification of biomarkers as well as understanding bodily functions, which occur in living organisms at the molecular level. The irreplaceable tool for these examinations is proteomics, which includes both quality and quantity analysis of proteins composition, and also makes it possible to learn their functions and expressions. The success of proteomics examinations lies in the usage of innovative analytical techniques, such as electromigration technique, two-dimensional electrophoresis in polyacrylamide gel (2D PAGE), liquid chromatography, together with high resolution mass spectrometry and bio-informatical data analysis. Proteomics joins together a number of techniques used for analysis of hundreds or thousands of proteins. Its main task is not the examination of proteins inside the particular tissue but searching for the differences in the proteins' profile between bad and healthy tissues. These differences can tell us a lot regarding the cause of the sickness as well as its consequences. For instance, using the proteomics analysis it is possible to find relatively fast new biomarkers of tumor diseases, which in the future will be used for both screening and foreseeing the course of illness. In this chapter we focus on two-dimensional electrophoresis because as it seems, it may be of enormous importance when searching for biomarkers of cancer diseases.

K?odzi?ska, Ewa; Buszewski, Bogus?aw

314

Heat-induced whey protein gels: protein-protein interactions and functional properties.  

PubMed

Heat-induced gelation (80 degrees C for 30 min or 85 degrees C for 60 min) of whey protein concentrate (WPC) solutions was studied using small deformation dynamic rheology, small and large deformation compression, and polyacrylamide gel electrophoresis (PAGE). The WPC solutions (15% w/w, pH 6.9) were prepared by dispersing WPC powder in water (control), 1% (w/w) sodium dodecyl sulfate (SDS) solution, and N-ethylmaleimide (NEM) solution at a protein/NEM molar ratio of 1:1 or in 10 mM dithiothreitol (DTT) solution. PAGE analyses showed that the heat treatment of control solutions contained both disulfide and non-covalent linkages between denatured protein molecules. Only disulfide linkages were formed in heated SDS-WPC solutions, whereas only non-covalent linkages were formed in DTT-WPC and NEM-WPC solutions during heating. In heated NEM-WPC solutions, the pre-existing disulfide linkages remained unaltered. Small deformation rheology measurements showed that the storage modulus (G') values, compared with those of the control WPC gels (approximately 14000 Pa), were 3 times less for the SDS-WPC gels (approximately 4000 Pa), double for the NEM-WPC gels (approximately 24000 Pa), and even higher for the DTT-WPC gels (approximately 30000 Pa). Compression tests suggested that the rubberiness (fracture strain) of the WPC gels increased as the degree of disulfide linkages within the gels increased, whereas the stiffness (modulus) of the gels increased as the degree of non-covalent associations among the denatured protein molecules increased. PMID:19199595

Havea, Palatasa; Watkinson, Philip; Kuhn-Sherlock, Barbara

2009-02-25

315

Our Native Ways: The Voices of Native American Youth.  

ERIC Educational Resources Information Center

To celebrate the "Decade of the Indigenous Peoples," this issue of a nonprofit children's magazine includes art and writings by Native American youth who share their ways of looking at and living life. Emphasizes the distinct customs, traditions, languages, and folklore of the different Native Nations and Tribes. (LZ)

Toke, Arun Narayan, Ed.; And Others

1994-01-01

316

Introduced brown trout alter native acanthocephalan infections in native fish  

E-print Network

galaxias (Galaxias anomalus) have been observed, suggesting that parasite dilution is occurring. 3. We used­parasite dynamics in native roundhead galaxias. 4. Field observations demonstrated higher infection intensity in introduced trout than in native galaxias, but only small, immature A. galaxii were present in trout

Poulin, Robert

317

Detection of cation-specific conformational changes in ribosomal RNA by gel electrophoresis.  

PubMed

Electrophoresis of ribosomal RNA in polyacrylamide-agarose composite gels separates 16S and 23S species into multiple bands. These bands of RNA represent multiple conformational forms of the molecules as judged by oligonucleotide analysis of the 16S RNA. Gel electrophoresis was used to test for cation-specific conformational changes in ribosomal RNA. Relative to magnesium-equilibrated RNA, barium ion and putrescine induced alterations in the electrophoretic behavior of ribosomal RNA while calcium ion produced no change. Exchange of a critical level of bound magnesium ion for barium or putrescine was necessary for these changes to take place. The alterations in electrophoretic behavior were unaffected by simply restoring magnesium ion, but in addition required heating for reversal. We suggest that these conformational changes are a result of interaction at a specific class of cation binding sites previously observed with intact ribosomes. PMID:10793686

Morris, D R; Dahlberg, J E; Dahlberg, A E

1974-10-01

318

Detection of cation-specific conformational changes in ribosomal RNA by gel electrophoresis.  

PubMed

Electrophoresis of ribosomal RNA in polyacrylamide-agrose composite gels separates 16S and 23S species into multiple bands. These bands of RNA represent multiple conformational forms of the molecules as judged by oligonucleotide analysis of the 16S RNA. Gel elctrophoresis was used to test for cation-specific conformational changes in ribosomal RNA. Relative to magnesium-equilibrated RNA, barium ion and putrescine induced alterations in the electrophoretic behavior of ribosomal RNA while calcium ion produced no change. Exchange of a critical level of bound magnesium ion for barium or putrescine was necessary for these changes to take place. The alterations in electrophoretic behavior were unaffected by simply restoring magnesium ion, but in addition required heating for reversal. We suggest that these conformational changes are a result of interaction at a specific class of cation binding sites previously observed with intact ribosomes. PMID:1094419

Morris, D R; Dahlberg, J E; Dahlberg, A E

1975-04-01

319

Detection of cation-specific conformational changes in ribosomal RNA by gel electrophoresis  

PubMed Central

Electrophoresis of ribosomal RNA in polyacrylamide-agarose composite gels separates 16S and 23S species into multiple bands. These bands of RNA represent multiple conformational forms of the molecules as judged by oligonucleotide analysis of the 16S RNA. Gel electrophoresis was used to test for cation-specific conformational changes in ribosomal RNA. Relative to magnesium-equilibrated RNA, barium ion and putrescine induced alterations in the electrophoretic behavior of ribosomal RNA while calcium ion produced no change. Exchange of a critical level of bound magnesium ion for barium or putrescine was necessary for these changes to take place. The alterations in electrophoretic behavior were unaffected by simply restoring magnesium ion, but in addition required heating for reversal. We suggest that these conformational changes are a result of interaction at a specific class of cation binding sites previously observed with intact ribosomes. Images PMID:10793686

Morris, David R.; Dahlberg, James E.; Dahlberg, Albert E.

1974-01-01

320

Detection of cation-specific conformational changes in ribosomal RNA by gel electrophoresis.  

PubMed Central

Electrophoresis of ribosomal RNA in polyacrylamide-agrose composite gels separates 16S and 23S species into multiple bands. These bands of RNA represent multiple conformational forms of the molecules as judged by oligonucleotide analysis of the 16S RNA. Gel elctrophoresis was used to test for cation-specific conformational changes in ribosomal RNA. Relative to magnesium-equilibrated RNA, barium ion and putrescine induced alterations in the electrophoretic behavior of ribosomal RNA while calcium ion produced no change. Exchange of a critical level of bound magnesium ion for barium or putrescine was necessary for these changes to take place. The alterations in electrophoretic behavior were unaffected by simply restoring magnesium ion, but in addition required heating for reversal. We suggest that these conformational changes are a result of interaction at a specific class of cation binding sites previously observed with intact ribosomes. Images PMID:1094419

Morris, D R; Dahlberg, J E; Dahlberg, A E

1975-01-01

321

A simple and fast procedure for high quality DNA isolation from gels using laundry detergent and inverted columns.  

PubMed

A quick method for the recovery of DNA from agarose and polyacrylamide gels with high efficiency and quality is described. Excised gel slices, containing at least 10 ng DNA, are incubated for 15 min at 60 degrees C in the presence of laundry detergents. An "inverted column" is obtained by covering the extraction liquid by a layer of cotton wool, Sephadex G-50 and another layer of cotton wool. Following centrifugation the supernatant containing the DNA is recovered by aspiration and the DNA is precipitated with isopropanol and tRNA, washed with ethanol and air-dried. The yield of reisolated DNA does not depend on DNA fragment size and small quantities of gel volume. Thus, the technique may prove useful in a broad range of applications in the methodology of molecular biology. PMID:9237563

Pusch, C

1997-06-01

322

Application of an improved system of electrophoresis in acrylamide gel to studies on the sera of different species.  

PubMed

Polyacrylamide gels constitute a generally better matrix for routine electrophoresis of serum proteins than other media commonly employed, but the immunoglobulin fractions of the largest size may not migrate into gels in which the acrylamide concentration exceeds 5%. To facilitate adequate separation, slabs containing a semi-solid layer were prepared from discontinuous gels consisting of 2 to 8% acrylamide. Serum samples were subjected to electrophoresis, under carefully controlled conditions at pH 9.0, by means of a pulsed constant power supply. The method provided a rapid, reproducible, and relatively simple technique for the study of human serum proteins, either by electrophoresis or by immunoelectrophoresis, and for differentiation of serum samples from various animal species. PMID:5043376

Hyslop, N S

1972-06-01

323

Gastrointestinal Mucus Gel Barrier  

Microsoft Academic Search

A family of glycoproteins, known as gel-forming mucins, endow gastrointestinal mucus with its characteristic viscoelastic\\u000a and biological properties. In the mucus, these large oligomeric glycoproteins are organized into entangled networks that occasionally\\u000a can be stabilized by non-covalent interactions as in the stomach lumen. This network is a formidable chemical and physical\\u000a barrier that not only protects the underlying epithelia but

Juan Perez-Vilar

324

MAGIC Gel Dosimetry  

NASA Astrophysics Data System (ADS)

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.

Mifflin, Rachel; Shahnazi, Kambiz; Jesseph, Rick

2008-10-01

325

Ocular tolerance of sertaconazole gel.  

PubMed

The in vitro and in vivo tolerance of sertaconazole gel, a new topical azole antifungal, was studied. Ketoconazole gel (Panfungol) was used as a reference substance. The methods applied for tolerance assessment were the bovine corneal opacity and permeability test for the in vitro assay and a modified Draize test for the in vivo assay. The results obtained show that both substances can be classified as slightly irritant and with acceptable tolerance. However, unlike ketoconazole gel, sertaconazole gel did not cause a positive lesion index in vivo. Ketoconazole was 5.25 times more irritant in vitro than sertaconazole gel, whose effect was similar to that of saline solution. Consequently, the negligible irritant effect of sertaconazole gel on a type of epithelium that is extremely sensitive, i.e. the cornea, confirms the good tolerance of this new antifungal gel on other structures such as the skin and mucous membranes. PMID:8786760

Romero, A; Grau, M T; Villamayor, F; Zapatero, J; Mayordomo, L; Tortajada, A; Sacristán, A; Ortiz, J A

1996-01-01

326

Native American Adolescent Career Development  

Microsoft Academic Search

Within the framework of Social Cognitive Career (SCCT; Lent, Brown, & Hackett, 1994, 2000), this study examined the associations among career interests, career efficacy expectations, gender, and perceived parent support among Native American and Caucasian middle school adolescents. Consistent with previous research, results indicated that Native American young people had greater interests in Realistic and Conventional occupations, and in occupations

Sherri L. Turner; Richard T. Lapan

2003-01-01

327

Native American Adolescent Career Development.  

ERIC Educational Resources Information Center

Career interests, efficacy expectations, and parental support were measured for 120 Native American and 134 Caucasian adolescents. Native Americans had greater interest in Realistic and Commercial occupations and those requiring high school diploma, trade school, or two-year postsecondary education. They were similar to Caucasians in range of…

Turner, Sherri L.; Lapan, Richard T.

2003-01-01

328

Alaska Natives In Higher Education.  

ERIC Educational Resources Information Center

This study examines changes in the entrance and success rates of Native students in Alaska colleges from 1963 to 1972, a time when special college recruitment and assistance programs were being developed. Information is based on the college records of those Natives who entered college for the first time at the University of Alaska at Fairbanks…

Kohout, Karen; Kleinfeld, Judith

329

Native American Perspectives on Generosity.  

ERIC Educational Resources Information Center

This is the last in a series of articles on the four elements of the Circle of Courage. Traditional Native American child development practices have created environments of belonging, mastery, independence, and generosity. Discusses the theme of generosity from a Native American perspective. (Author/GCP)

Brokenleg, Martin

1999-01-01

330

Native Tradition, Evolution and Creation.  

ERIC Educational Resources Information Center

Presents evidence that Native peoples' profound understanding of ecology, the nature of individuality, and resulting differences in survival and reproduction led them to develop ideas of evolution through natural selection long before Europeans. Suggests that in order to survive, Native Americans must not allow Western ways of thought, which are…

Pierotti, Raymond; Wildcat, Daniel R.

1997-01-01

331

Native American Curriculum Resource Guide.  

ERIC Educational Resources Information Center

This guide aims to assist the faculty member who wishes to integrate Native American materials into core courses of the curriculum. The first section is a bibliography of over 350 entries, primarily books and journal articles, arranged in the following categories: Native American bibliographies and general sources, history, economics,…

McCoy, Melanie, Ed.

332

Physical Activity and Native Americans  

Microsoft Academic Search

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

James D. Coble; Ryan E. Rhodes

2006-01-01

333

Alcohol abuse among Native Americans  

Microsoft Academic Search

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

Roland J. Lamarine

1988-01-01

334

Genetic conservation of native trees  

E-print Network

, 2001). Chloroplast DNA investigations have continued and include work on veteran oak treesGenetic 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

335

Understanding Native American healing practices  

Microsoft Academic Search

Counselor cultural competency with respect to Native Americans requires understanding of common healing practices and ceremonies and of their spiritual significance. Historical trauma serves as a general backdrop for Native America experience and identity. Particular tribal practices and the individual's degree of affiliation with such practices provide a more specific context for client worldview. Knowledge of the symbolic significance of

Christopher Rybak; Amanda Decker-Fitts

2009-01-01

336

Native Americans: The First Campers.  

ERIC Educational Resources Information Center

Questions are presented to help camps determine if their usage of American Indian culture truly honors Native Americans. Camps that plan to use Indian lore should research the tribe's name, location, symbols, legends, and living habits. A 5-day program is presented for enhancing campers' understanding of Native peoples and their relationship to…

Dunn, Bonnie; Frebertshauser, Denise

2002-01-01

337

Native Americans as Sports Mascots.  

ERIC Educational Resources Information Center

Discusses the controversy over whether sport teams should use Native American logos, mascots, or native symbols. Suggests that by implementing role-reversal techniques (putting the nonnative people in the same place) uncaring sports fans may recognize the disrespect involved; offers a hypothetical newspaper article that illustrates the…

Muir, Sharon Pray

1999-01-01

338

Native Language Literacy Screening Device.  

ERIC Educational Resources Information Center

The purpose the Native Language Literacy Screening Device (NLLSD) is to give English for Speakers of Other Languages (ESOL) practitioners a sense of the native language literacy levels of learners coming into their programs. This is worth knowing because when learners have had limited schooling in their first language instructional strategies used…

Hudson River Center for Program Development, Glenmont, NY.

339

BachelorofArts NativeAmericanStudies  

E-print Network

BachelorofArts NativeAmericanStudies N a m e : ______________________________________ I DL website at www.uleth.ca/ross/ppgs/ppg.html About the Native American Studies Major The Native American. Opportunities for Native American Studies Majors Native American Studies is a growing academic field

Seldin, Jonathan P.

340

NATIVE AMERICAN www.nas.pdx.edu  

E-print Network

NATIVE AMERICAN STUDIES www.nas.pdx.edu PSU's Native American Studies (NAS) Program is program was inaugurated in 2004 and presently offers a Minor in Native American Studies. NAS is an interdisciplinary of American Indians, Alaska Natives, and Native Hawaiians. e minor is meant to serve three primary

341

Encapsulation of the ferritin protein in sol-gel derived silica glasses  

Microsoft Academic Search

A significant recent development in sol-gel science has been the encapsulation of biomolecules such as proteins and enzymes in optically transparent silica glasses. This paper reports on the encapsulation of an iron (Fe) storage protein, ferritin, to develop a magnetic silica glass. Native ferritin, which has a nanometer-sized microcrystalline Fe oxide core, was encapsulated in optically transparent silica glasses using

Esther H. Lan; Bruce Dunn; Joan Selverstone Valentine; Jeffrey I. Zink

1996-01-01

342

Effects of counter ions of clay platelets on the swelling behavior of nanocomposite gels.  

PubMed

The effects of replacing the native Na(+) counter ions associated with the clay platelets by various other cations on the swelling behavior of nanocomposite (NC) gels consisting of an organic (polymer)/inorganic (clay) network were investigated. The negative surface charge of the clay platelet conferred an ionic nature on the NC gels making them a type of polyelectrolyte gel; consequently, the swelling behavior of the NC gels was strongly influenced by the valence of the co-existing counter ions. NC gels containing monovalent cations such as Na(+), K(+) and Li(+) exhibited large swellings and subsequent deswelling in water after attaining maximum degrees of swelling. In contrast, introduction of multivalent cations such as Ca(2+), Mg(2+), and Al(3+) into NC gels depressed markedly both the swelling and subsequent deswelling. The decreased swelling and suppressed deswelling with multivalent ions were strongly influenced by the initial gel state and result from the formation of additional cross-links through ionic interactions between the clay platelets and the multivalent cations. Also, the similar swelling behaviors were observed for all NC gels with different clay concentration. Further, reversible absorption/desorption and selective absorption of multivalent cations were observed for the NC gels examined. PMID:22425253

Ren, Huai-Yin; Zhu, Meifang; Haraguchi, Kazutoshi

2012-06-01

343

Strategies Used by Native Speakers in Native-Non-Native Conversations.  

ERIC Educational Resources Information Center

Discourse analysis has provided a methodology for the study of conversational interactions between language learner and native speaker. This study examines the verbal and nonverbal strategies that native speakers use when communicating with second language learners in natural, non-academic, "survival type" settings. The areas discussed include:…

Carty, Maria A.

344

Native American Studies Page 203Sonoma State University 2012-2013 Catalog NATIVE AMERICAN STUDIES  

E-print Network

Native American Studies Page 203Sonoma State University 2012-2013 Catalog NATIVE AMERICAN STUDIES, American Indian Religion & Philosophy, Native American Education and North American History Gregory Sarris / Native American Literature Program Offered Minor in Native American Studies The Native American Studies

Ravikumar, B.

345

Development and optimization of a 2-hydroxyethylacrylate MRI polymer gel dosimeter  

NASA Astrophysics Data System (ADS)

In this study, radiation induced changes in a polymer gel dosimeter manufactured using 2-hydroxyethylacrylate (HEA) and N,N'-methylene-bisacrylamide (BIS) were investigated using magnetic resonance imaging (MRI) and FT-Raman spectroscopy. The variation in magnetic resonance relaxation time (T2) with absorbed dose was modelled assuming fast exchange of magnetization. Overall good agreement between the model and experimental data was obtained. However, comparison with FT-Raman data suggests that not all the protons attached to the polymer contribute to the relaxation process. Furthermore, for certain compositions improved agreement with experimental data was achieved when a lower fraction of polymer protons available for exchange with water was assumed in the low dose region. This indicates that the T2 value is influenced by the composition and topology of the formed polymer, which may vary with absorbed dose. The concept of percentage dose resolution (DpDgr,%) was introduced to enable optimization of gel compositions for use in relative dosimetry applications. This concept was applied to demonstrate the effects of varying the gelatine concentration, the total fraction of monomer/crosslinker (%T) and the relative fraction of crosslinker (%C) on gel performance in HEA gels as well as compare the performance of HEA and a standard polyacrylamide gel (PAG). The percentage dose resolution was improved for all HEA gels compared to the PAG dosimeter containing 3% acrylamide and 3% BIS. Increasing the total concentration of monomer was shown to have the largest single effect. In the range of doses of interest for clinical radiation therapy, DpDgr,% for the optimal HEA gel (4% HEA, 4% BIS) was lower than 2.3%, compared to 3.8% for the PAG dosimeter.

Gustavsson, H.; Bäck, S. Å. J.; Lepage, M.; Rintoul, L.; Baldock, C.

2004-01-01

346

High transparent shape memory gel  

NASA Astrophysics Data System (ADS)

Gels are a new material having three-dimensional network structures of macromolecules. They possess excellent properties as swellability, high permeability and biocompatibility, and have been applied in various fields of daily life, food, medicine, architecture, and chemistry. In this study, we tried to prepare new multi-functional and high-strength gels by using Meso-Decoration (Meso-Deco), one new method of structure design at intermediate mesoscale. High-performance rigid-rod aromatic polymorphic crystals, and the functional groups of thermoreversible Diels-Alder reaction were introduced into soft gels as crosslinkable pendent chains. The functionalization and strengthening of gels can be realized by meso-decorating the gels' structure using high-performance polymorphic crystals and thermoreversible pendent chains. New gels with good mechanical properties, novel optical properties and thermal properties are expected to be developed.

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

2014-03-01

347

Foam and gel decontamination techniques  

SciTech Connect

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 gel that adheres to the surface being decontaminated for periods ranging from fifteen minutes (foam) to infinite contact (gel). This equipment was started up in a cold environment. The desired foam and gel consistency was achieved, operators were trained in its proper maintenance and operation, and the foam and gel were applied to walls, ceilings, and hard to reach surfaces. 17 figs.

McGlynn, J.F.; Rankin, W.N.

1989-01-01

348

Response of hydroponically grown head lettuce on residual monomer from polyacrylamide.  

PubMed

The aim was to assess acrylamide monomer (AMD) uptake by hydroponically grown lettuce. Lettuce was cultivated by applying plant tissue testing in a recycled system by the use of nutrient solutions prepared with two water-soluble flocculants F3 and F4 containing 176 and 763 mg kg(-1) of AMD, respectively. The effects on growth, fresh weight and plant leaf quality were evaluated by comparing these treatments and one control standard nutrient solution typically recommended for lettuce hydroponic cultivation. To assess the nutritional status of lettuce, samples were collected and lyophilised before determination of the selected micro- and macro-element contents. An HPLC with photodiode array detector method was applied to determine AMD in both selected flocculants and dried plant samples. Results show that lettuces cultivated under the conditions described above absorb AMD from nutrient solutions into their leaves. The AMD presence in recycled nutrient solutions has a negative influence on the growth of lettuce, reducing their average fresh weight and average number of leaves. The study confirmed that the problem of AMD mobility and its accumulation risk in plants should to be an important topic with respect to safe polyacrylamide (PAM) handling in the agro food area. PMID:24916210

Mroczek, E; Konieczny, P; Kleiber, T; Wa?kiewicz, A

2014-08-01

349

Water Soluble Usnic Acid-Polyacrylamide Complexes with Enhanced Antimicrobial Activity against Staphylococcus epidermidis  

PubMed Central

Usnic acid, a potent antimicrobial and anticancer agent, poorly soluble in water, was complexed to novel antimicrobial polyacrylamides by establishment of strong acidic-base interactions. Thermal and spectroscopic analysis evidenced a molecular dispersion of the drug in the polymers and a complete drug/polymer miscibility for all the tested compositions. The polymer/drug complexes promptly dissolved in water and possessed a greater antimicrobial activity against Staphylococcus epidermidis than both the free drug and the polymer alone. The best results were obtained with the complex based on the lowest molecular weight polymer and containing a low drug content. Such a complex showed a larger inhibition zone of bacterial growth and a lower minimum inhibitory concentration (MIC) with respect to usnic acid alone. This improved killing effect is presumably due to the reduced size of the complexes that allows an efficient cellular uptake of the antimicrobial complexes. The killing effect extent seems to be not significantly dependent on usnic acid content in the samples. PMID:23549269

Francolini, Iolanda; Taresco, Vincenzo; Crisante, Fernanda; Martinelli, Andrea; D'Ilario, Lucio; Piozzi, Antonella

2013-01-01

350

Competition between kaolinite flocculation and stabilization in divalent cation solutions dosed with anionic polyacrylamides.  

PubMed

Divalent cations have been reported to develop bridges between anionic polyelectrolytes and negatively-charged colloidal particles, thereby enhancing particle flocculation. However, results from this study of kaolinite suspensions dosed with various anionic polyacrylamides (PAMs) reveal that Ca(2+) and Mg(2+) can lead to colloid stabilization under some conditions. To explain the opposite but coexisting processes of flocculation and stabilization with divalent cations, a conceptual flocculation model with (1) particle-binding divalent cationic bridges between PAM molecules and kaolinite particles and (2) polymer-binding divalent cationic bridges between PAM molecules is proposed. The particle-binding bridges enhanced flocculation and aggregated kaolinite particles in large, easily-settleable flocs whereas the polymer-binding bridges increased steric stabilization by developing polymer layers covering the kaolinite surface. Both the particle-binding and polymer-binding divalent cationic bridges coexist in anionic PAM- and kaolinite-containing suspensions and thus induce the counteracting processes of particle flocculation and stabilization. Therefore, anionic polyelectrolytes in divalent cation-enriched aqueous solutions can sometimes lead to the stabilization of colloidal particles due to the polymer-binding divalent cationic bridges. PMID:22921393

Lee, Byung Joon; Schlautman, Mark A; Toorman, Erik; Fettweis, Michael

2012-11-01

351

Self-assembled reduced graphene oxide/polyacrylamide conductive composite films.  

PubMed

Substrate supported conductive thin films are prepared by the self-assembly of graphene oxide (GO) on a cationic polyacrylamide (CPAM) layer followed by a subsequent chemical reduction. During self-assembly, the dispersed GO nanosheets with a negative zeta potential from solution are spontaneously assembled onto the positively charged CPAM adsorption layer. In addition, CPAM adsorption on the substrate is studied with an electrochemical quartz crystal microbalance (EQCM), showing adsorption stabilization could be established in less than 150 s. The electrostatic interactions between GO and CPAM are investigated by changing the polarization potential with EQCM for the first time, and optimal conditions for facilitating self-assembly are determined. The self-assembled GO/CPAM films are further characterized by Raman spectroscopy, infrared spectroscopy and atomic force microscopy. Importantly, reduced GO (R-GO)/CPAM composite films exhibiting a sheet resistance of 3.1 k?/sq can be obtained via in situ reduction in sodium borohydride for 20 min at room temperature. This provides a simple, highly effective, and green route to prepare conductive graphene-based composite thin films. PMID:25329422

Yu, Shiyou; Li, Ning; Higgins, Drew; Li, Deyu; Li, Qing; Xu, Hui; Spendelow, Jacob S; Wu, Gang

2014-11-26

352

Hydroxypropyl methyl cellulose grafted with polyacrylamide: application in controlled release of 5-amino salicylic acid.  

PubMed

In the present study, hydroxypropyl methyl cellulose grafted with polyacrylamide (HPMC-g-PAM) hydrogel was evaluated in vitro as a potential carrier for controlled release of 5-amino salicylic acid (5-ASA). The graft copolymer was developed by grafting PAM chains onto HPMC backbone using potassium persulphate as initiator. The swelling behaviour of hydrogel based tablet was investigated as a function of pH and time in various buffer solutions similar to that of gastric and intestinal fluids. The % equilibrium swelling was found to be higher in case of simulated intestinal fluid (pH=7.4) and lower in simulated gastric fluid (pH=1.2), making an ideal matrix as required for colon specific drug delivery. The drug release study was performed at various pH values akin to the condition of GI tract. The release kinetics of 5-ASA showed non-Fickian diffusion behaviour. This indicates that the release is controlled by a combination of polymer relaxation or erosion of the matrix and diffusion of the drug from the swollen matrix. PMID:23732799

Das, Raghunath; Pal, Sagar

2013-10-01

353

Polyacrylamide hydrogel injection for augmentation mammaplasty: loss of ability for breastfeeding.  

PubMed

Polyacrylamide hydrogel (PAAG) has been widely used for injection augmentation mammaplasty in Russia, China, and Iran for more than 2 decades. In recent years, it has been advocated as a safe permanent filler for soft-tissue augmentation. However, the complications associated with PAAG injection in soft-tissue augmentation have not been extensively investigated. Augmentation mammaplasty through PAAG injection is associated with some complications. The incidence of infection during breastfeeding was reported to be higher than 50%. Herein, we report 58 cases of infection in breastfeeding women receiving PAAG injection, including 50 with unilateral injection (36 on the right, 14 on the left) and 8 bilateral injection. They experienced large breast autoinflation and some severe symptoms, such as local and systemic fever, breast swelling, nipple bulging, tenderness, and pain, which lead to surgical removal of galactocele or intraprosthetic collection of sterile pus resulting in deformity. Operation and comprehensive measures including removal of the injected material, clearing residual cavity, and pharmacotherapy were carried out to control infection and inflammation for 1 to 2 weeks. In the following 12 months, no relapse or recurrence of residual cavity was noted. Therefore, we do not recommend PAAG injection for augmentation mammaplasty, especially in women intending to breastfeed. Patients undergoing PAAG injection for augmentation mammaplasty should avoid breastfeeding. PAAG injection will cause serious consequences resulting in tissue atrophy and breast resection if inappropriately handled. PMID:21785335

Wang, Zhen-Xiang; Luo, Dong-Lin; Dai, Xia; Yu, Pan; Tao, Ling; Li, Shi-Rong

2012-08-01

354

Polyacrylamide-hydroxyapatite composite: Preparation, characterization and adsorptive features for uranium and thorium  

NASA Astrophysics Data System (ADS)

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.

Bayba?, Demet; Ulusoy, Ulvi

2012-10-01

355

Reducing sediment and phosphorus in tributary waters with alum and polyacrylamide.  

PubMed

The Salton Sea is the largest inland water body in California, covering an area of 980 km(2). Inflow to the Salton Sea (1.6 km(3) yr(-1)) is predominately nutrient-rich agricultural wastewater, which has led to eutrophication. Because internal phosphorus release from the bottom sediments is comparatively low and external phosphorus loading to the Salton Sea is high, reduction of tributary phosphorus is expected to reduce algal blooms, increase dissolved oxygen, and reduce odors. Removing both dissolved phosphorus and phosphorus-laden sediment from agricultural drainage water (ADW) should decrease eutrophication. Both alum and polyacrylamide (PAM) are commonly used in wastewater treatment to remove phosphorus and sediment and were tested for use in tributary waters. Laboratory jar tests determined PAM effectiveness (2 mg L(-1)) for turbidity reduction as cationic > anionic = nonionic. Although cationic PAM was the most effective at reducing turbidity at higher speeds, there was no observed difference between the neutral and anionic PAMs at velocity gradients of 18 to 45 s(-1). Alum (4 mg L(-1) Al) reduced turbidity in low energy systems (velocity gradients < 10 s(-1)) by 95% and was necessary to reduce soluble phosphorus, which comprises 47 to 100% of the total P concentration in the tributaries. When PAM was added with alum, the anionic PAM became ineffective in aiding flocculation. The nonionic PAM (2 mg L(-1)) + alum (4 mg L(-1) Al) is recommended to reduce suspended solids in higher energy systems and reduce soluble P by 93%. PMID:16221819

Mason, L B; Amrhein, C; Goodson, C C; Matsumoto, M R; Anderson, M A

2005-01-01

356

Shear thickening compositions containing polyacrylic acid and polyacrylamide, their preparation and use  

SciTech Connect

A process is described for plugging a portion of a well bore using a shear-thickening composition and a emulsion spacer where a conduit, which contains a fluid, extends down into a well bore from the surface to at least that portion to be plugged and where the shear-thickening composition comprises a water-in-oil emulsion having particles of hydratable, water-expandable clay dispersed in the continuous oily phase. The oily phase comprises a hydrocarbon liquid having a surfactant dissolved in which surfactant comprises a polyamine attached to an oil solubilizing hydrocarbon with or without an intervening bridging group and where the dispersed aqueous phase of the emulsion comprises an aqueous polymer solution, having a pH below 7, of both a polyacrylic acid and polyacrylamine. The spacer comprises a water-in-oil emulsion having a composition similar to the water-in-oil emulsion of the shear-thickening composition and each droplet of dispersed aqueous phase of the shear-thickening composition is encapsulated in a film which forms as a result of the interaction of the polyacrylic acid, surfactant and polyacrylamide.

Eustace, D.J.; Siano, D.B.; Drake, E.N.; Calcavecchio, P.

1987-08-04

357

One step synthesis of polyacrylamide functionalized graphene and its application in Pb(II) removal  

NASA Astrophysics Data System (ADS)

Polyacrylamide grafted graphene (PAM-g-graphene) from graphite oxide (GO) was successfully prepared by ?-ray irradiation with acrylamide monomers in aqueous at room temperature in this paper. Our strategy involves the PAM chains graft on the surface and between the layers of GO by in situ radical polymerization which led to the exfoliation of GO into individual sheets. Results show that the degree of grafting of PAM-g-graphene samples is 24.2%, and the thickness is measured to be 2.59 nm. Moreover, the as-prepared PAM-g-graphene with some amino from PAM and little oxygen functional groups exhibit superior adsorption of Pb(II) ions. The adsorption processes reach equilibrium in just 30 min and the adsorption isotherms are described well by Langmuir and Freundlich classical isotherms models. The determined adsorption capacity of PAM-g-graphene is 819.67 mg g-1 (pH 6) for Pb(II), which is 20 times and 8 times capacities of that for graphene nanosheets and carbon nanotubes according to reports, respectively. This chemically modified graphene synthesized by this fast one-step approach, featuring a good versatility and adaptability, excellent adsorption capacity and rapid extraction, may provide a new idea for the global problem of heavy metal pollutants’ removal in water.

Xu, Zhiwei; Zhang, Yaoyao; Qian, Xiaoming; Shi, Jie; Chen, Lei; Li, Baodong; Niu, Jiarong; Liu, Liangsen

2014-10-01

358

Polyoxometalate-based Supramolecular Gel  

PubMed Central

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. PMID:23666013

He, Peilei; Xu, Biao; Liu, Huiling; He, Su; Saleem, Faisal; Wang, Xun

2013-01-01

359

Mechanical properties of biological gels  

NASA Astrophysics Data System (ADS)

The rheological properties of biological gels are illustrated by reviewing measurements made on samples containing polymer networks reconstituted from cytoskeletal constitutents. Although these networks are crosslinked by non-covalent interactions which may lead to transient gel behavior, the early-time (rapid) mechanical response of the gels can be characterized by the instantaneous shear modulus. A theory for the latter is described, and used to examine the relationship between the cortical f-actin content and the stiffening of activated polymorphonuclear leukocytes.

Nossal, Ralph

1996-02-01

360

Alaska Native Teens Help Researchers  

NSDL National Science Digital Library

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.

Foundation, Wgbh E.

2009-01-13

361

Native Americans in College Textbooks.  

ERIC Educational Resources Information Center

Pejorative terms, biased or incomplete maps and illustrations, outdated bibliographies, and narrow or missing coverage characterize the treatment of Native Americans in the latest editions of three leading textbooks used in college level American history survey courses. (SB)

Wilson, Raymond

1980-01-01

362

Native American Studies at Dartmouth  

E-print Network

Native American Studies at Dartmouth Colin G. Calloway Dartmouth College, in Hanover, New Hampshire, was founded in 1769 by Eleazar Wheeiock. At the same time, Wheelock relocated Moor's Charity School from Lebanon, Connecticut, to the Dartmouth... campus, for the education of Native American students. In an effort to raise funds for his school, Wheelock dispatched a Mohegan Indian named Samson Occom to the British Isles. Occom, a former student of Wheelock and an ordained minister, delivered...

Calloway, Colin G.

2001-03-01

363

A simple monolithic column electroelution for protein recovery from gel electrophoresis.  

PubMed

Protein recovery from gel electrophoresis plays an important role in functional genomics and proteomics but faces a series of issues (e.g., complex procedure, low recovery, long experimental time). In this study, a monolithic column electroelution (MCE) was developed for protein recovery from gel electrophoresis. With the model proteins of bovine serum albumin (BSA), hemoglobin (Hb), and myoglobin (Mb), the developed device and method were compared with common electroelution procedures in agarose gel electrophoresis (AGE). The comparative experiments revealed that (i) the protein recovery achieved with the developed device was greater than 83%, much higher than the 41% to 50% achieved with the common devices; (ii) the running time to obtain 70% recovery was approximately 15 min, evidently shorter than the 240 min with the common devices; and (iii) the device and procedure were simple and less time-consuming as compared with those of the common devices. It was observed that the serum protein bands cut from polyacrylamide gel electrophoresis could be transferred into solution in 15 to 30 min with 82% yield. The device, along with its relevant procedure, has potential use in protein extraction and proteomics as well as in DNA studies. PMID:22800655

Li, Guo-Qing; Shao, Jing; Guo, Chen-Gang; Dong, Jing-Yu; Fan, Liu-Yin; Cao, Cheng-Xi

2012-11-01

364

Screening of phage-displayed human liver cDNA library against doxorubicin with drug-immobilized monolithic polyacrylamide cryogel.  

PubMed

Monolithic polyacrylamide cryogel was prepared and utilized as a new matrix for drug immobilization to screen against phage-displayed human liver cDNA library. The macropores and hydrophilic nature of the cryogel made it possible for phage particles to pass unhindered. Doxorubicin, an anticancer drug, was covalently bonded to the monolithic cryogel by the glutaraldehyde method, and after five rounds of affinity selection performed in an SPE cartridge, phage clones that displayed Homo sapiens methyl CpG binding protein 2 (MeCP2 ) were selectively enriched. The interaction between doxorubicin and MeCP2 displayed phages was further validated by studying the retention of doxorubicin on MeCP2 phage-coupled cryogel. These results demonstrate that drug-coupled polyacrylamide cryogel might be a promising kind of matrix for screening target proteins against phage-displayed library. PMID:23852887

Yu, Xiaoming; Zhao, Peng; Zhang, Lihua; Zhang, Yukui

2013-11-01

365

Polyacrylamide as an organic nitrogen source for soil microorganisms with potential effects on inorganic soil nitrogen in agricultural soil  

Microsoft Academic Search

Linear polyacrylamide (PAM) is gaining considerable acceptance as an effective anti-erosion additive in irrigation water. The potential effects of repeated PAM application on soil microbial ecology and the potential for biotransformation of this polymer in soils are not completely known. Untreated and PAM-treated soils (coarse-silty, mixed, mesic Durixerollic Calciorthids) were collected from agricultural fields near Kimberly, ID. Soils were analyzed

Jeanine L. Kay-Shoemake; Mary E. Watwood; Rodrick D. Lentz; Robert E. Sojka

1998-01-01

366

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

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

Ajit Hazarika; Hirendra N. Sarma

2006-01-01

367

Electromechanical nonionic gels  

NASA Astrophysics Data System (ADS)

The electrically induced bending of nonionic polyvinyl alcohol gels, bending over 90° within 100 ms, is the fastest motion in the field of electroactuation of polymers. This rapid bending produces initial mechanical vibrations followed by a durable displacement that contrasts highly with the relaxation observed with elastomer- and polyelectrolyte-based actuators. Here, we characterize the bending process using video imaging and laser detecting technology and establish a physical model for the electromechanical conversion, based on our observation of an induced solvent migration. Our results show excellent agreement between the measurements and calculations. This study provides general rules for understanding the electrically induced bending of isotropic dielectrics and may also shed light on nonmuscular biological engines.

Zheng, J.; Xu, C.; Hirai, T.

2008-02-01

368

Difference gel electrophoresis.  

PubMed

DIGE is a protein labelling and separation technique allowing quantitative proteomics of two or more samples by optical fluorescence detection of differentially labelled proteins that are electrophoretically separated on the same gel. DIGE is an alternative to quantitation by MS-based methodologies and can circumvent their analytical limitations in areas such as intact protein analysis, (linear) detection over a wide range of protein abundances and, theoretically, applications where extreme sensitivity is needed. Thus, in quantitative proteomics DIGE is usually complementary to MS-based quantitation and has some distinct advantages. This review describes the basics of DIGE and its unique properties and compares it to MS-based methods in quantitative protein expression analysis. PMID:19003860

Timms, John F; Cramer, Rainer

2008-12-01

369

Nanocrystal/sol-gel nanocomposites  

DOEpatents

The present invention is directed to solid composites including colloidal nanocrystals within a sol-gel host or matrix and to processes of forming such solid composites. The present invention is further directed to alcohol soluble colloidal nanocrystals useful in formation of sol-gel based solid composites

Petruska, Melissa A. (Los Alamos, NM); Klimov, Victor L. (Los Alamos, NM)

2012-06-12

370

Nanocrystal/sol-gel nanocomposites  

DOEpatents

The present invention is directed to solid composites including colloidal nanocrystals within a sol-gel host or matrix and to processes of forming such solid composites. The present invention is further directed to alcohol soluble colloidal nanocrystals useful in formation of sol-gel based solid composites.

Petruska, Melissa A. (Los Alamos, NM); Klimov, Victor L. (Los Alamos, NM)

2007-06-05

371

Native American Healing Practices and Counseling  

ERIC Educational Resources Information Center

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…

Rybak, Christopher J.; Eastin, Carol Lakota; Robbins, Irma

2004-01-01

372

An overview of Native American outreach and  

E-print Network

Gathering Together: An overview of Native American outreach and education projects at MSU #12's Native American community. From encouraging young Native American students to pursue careers in science on reservations, you will see that MSU embraces Native American traditions and is committed to improving

Lawrence, Rick L.

373

The Problems with Native American Mascots.  

ERIC Educational Resources Information Center

Lays out the main arguments against the use of Native American mascots, including that mascots represent racist stereotypes of Native Americans; the stereotypes focus on the past and obscure the lives of contemporary Native Americans; mascots misrepresent, distort, and trivialize many aspects of Native American culture; and mascot stereotypes have…

Davis, Laurel R.

2002-01-01

374

The University of Montana Native American Center  

E-print Network

The University of Montana Native American Center "Pay attention and learn as much as you can American History also from a Native American perspective was important. This is what inspired her to obtain a degree in Native American Studies. "In learning about Native American culture, one of the things

Vonessen, Nikolaus

375

50 CFR 17.5 - Alaska natives.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Alaska natives. 17.5 Section 17.5 ...Introduction and General Provisions § 17.5 Alaska natives. (a) The provisions...is an Alaskan native and who resides in Alaska; or (2) Any non-native...

2013-10-01

376

50 CFR 17.5 - Alaska natives.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Alaska natives. 17.5 Section 17.5 ...Introduction and General Provisions § 17.5 Alaska natives. (a) The provisions...is an Alaskan native and who resides in Alaska; or (2) Any non-native...

2010-10-01

377

50 CFR 17.5 - Alaska natives.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Alaska natives. 17.5 Section 17.5 ...Introduction and General Provisions § 17.5 Alaska natives. (a) The provisions...is an Alaskan native and who resides in Alaska; or (2) Any non-native...

2012-10-01

378

50 CFR 17.5 - Alaska natives.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Alaska natives. 17.5 Section 17.5 ...Introduction and General Provisions § 17.5 Alaska natives. (a) The provisions...is an Alaskan native and who resides in Alaska; or (2) Any non-native...

2011-10-01

379

Native-American elders. Health care status.  

PubMed

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

Rousseau, P

1995-02-01

380

Diabetes in American Indians and Alaska Natives  

MedlinePLUS

... in American Indians and Alaska Natives Diabetes in American Indians and Alaska Natives American Indians/Alaska Natives (from the Office on Women’s ... as one of the health conditions common among American Indians/Alaska Natives. American Indian Health: An informational ...

381

Superporous hybrid hydrogels based on polyacrylamide and chitosan: Characterization and in vitro drug release  

PubMed Central

Objective: Current research was aimed at the development of the drug delivery systems based on the superporous hydrogels (SPH) with the desired swelling and the mechanical properties. Materials and Methods: Superporous hydrogel composites (SPHCs) and superporous hybrid hydrogels (SPHHs) based on the chitosan and the polyacrylamide were synthesized using the gas blowing technique. The prepared hydrogels were evaluated for swelling studies, mechanical strength and scanning electron microscopy. The selected hydrogels were loaded with the drug (verapamil hydrochloride) by aqueous loading method. Drug integrity with in polymeric network was evaluated via fourier transform infrared spectroscopy (FTIR), X-ray diffraction (X-RD), differential scanning calorimetry (DSC), proton nuclear magnetic resonance (1HNMR) studies. In vitro drug release studies were carried out using the united state pharmacopoeial (USP) dissolution apparatus (type II). Results and Discussion: The mechanical strength was observed to be higher in SPH hybrids in comparison to that in SPHCs while no significant difference was observed in swelling behavior. In situ crosslinking of chitosan with glutaraldehyde (GA) may be responsible for high mechanical strength. The equilibrium swelling time was slight higher in SPHH than in SPHCs. The integrity of pores was maintained in ethanol treated hydrogels as observed in scanning electron micrographs. Whereas, freeze dried SPH samples showed non-uniform pores. No drug polymer interaction was observed as indicated by DSC, FTIR, X-RD and NMR studies. However, the crosslinking of chitosan with GA was clearly indicated by these studies. The in vitro drug release studies from SPH hybrids indicated initial fast release (65%) with in first 2 h and then sustained release at the end of 24 h (95%). The addition of hydroxypropyl methyl cellulose with drug; however, leads to a significant decrease in drug release (56% at the end of 24 h). Conclusion: Superporous hybrid hydrogels can be promising devices for the sustained delivery of drug candidates to the gastrointestinal region. PMID:24015380

Nagpal, Manju; Singh, Shailendra Kumar; Mishra, Dinanath

2013-01-01

382

Tissue distribution and pharmacokinetics of stable polyacrylamide nanoparticles following intravenous injection in the rat  

SciTech Connect

A variety of polymer nanoparticles (NP) are under development for imaging and therapeutic use. However, little is known about their behavior. This study examined pharmacokinetics, distribution and elimination of stable polyacrylamide (PAA) nanoparticles ({approx} 31 nm average diameter). PAA NPs and polyethylene glycol-coated PAA NPs were injected into the tail veins of healthy male rats. Blood, tissues and excreta were collected at times ranging from 5 min to 120 h and their radioactive content was quantified. A mathematical model was then applied to analyze the distribution dynamics of both NPs. Elimination from the blood could be accounted for by a quick but finite relocation to the major organs (about 20%, 0.6 to 1.3 h half-lives), and a slower distribution to the carcass (about 70%, 35 to 43 h half-lives). Excreted urinary levels correlated with blood concentrations. Combined cumulative urinary and fecal output accounted for less than 6% of the dose at 120 h. Compared to five other polymeric nanoparticles, the studied particles are at the highest half-lives and Area Under the Curve (4000 to 5000%-h). These two parameters decrease by three orders of magnitude when nanoparticle size increases from the 30 nm range up to 250 nm. For similar sizes, pegylated nanoparticles are more persistent in the blood than non-pegylated ones, but this difference is much smaller in the 30 nm and relatively high dose range than above 100 nm. Persistence of PAA NPs is not associated with acute toxicity signs as measured by typical serum markers of inflammation and cellular damage.

Wenger, Yvan, E-mail: yvan@umich.edu [Risk Science Center, Department of Environmental Health Sciences, 109 S Observatory, University of Michigan School of Public Health, Ann Arbor, MI 48109-2029 (United States); Schneider, Randal J., E-mail: randal.schneider@phci.org [Risk Science Center, Department of Environmental Health Sciences, 109 S Observatory, University of Michigan School of Public Health, Ann Arbor, MI 48109-2029 (United States); Reddy, G. Ramachandra, E-mail: nexgennano@gmail.com [Next Generation Therapeutics, Inc., 2900 Huron Parkway, Suite 8, Ann Arbor, MI 48105-3454 (United States); Kopelman, Raoul, E-mail: kopelman@umich.edu [Department of Chemistry, 930 N. University Ave., University of Michigan, Ann Arbor, MI 48105-1055 (United States); Jolliet, Olivier, E-mail: ojolliet@umich.edu [Risk Science Center, Department of Environmental Health Sciences, 109 S Observatory, University of Michigan School of Public Health, Ann Arbor, MI 48109-2029 (United States); Philbert, Martin A., E-mail: philbert@umich.edu [Risk Science Center, Department of Environmental Health Sciences, 109 S Observatory, University of Michigan School of Public Health, Ann Arbor, MI 48109-2029 (United States)

2011-03-15

383

Living bacteria in silica gels  

NASA Astrophysics Data System (ADS)

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'.

Nassif, Nadine; Bouvet, Odile; Noelle Rager, Marie; Roux, Cécile; Coradin, Thibaud; Livage, Jacques

2002-09-01

384

Sonication-triggered instantaneous gel-to-gel transformation.  

PubMed

Two new peptide-based isomers containing cholesterol and naphthalic groups have been designed and synthesized. We found that the position of L-alanine in the linker could tune the gelation properties and morphologies. The molecule with the L-alanine residue positioned in the middle of the linker (1b) shows better gelation behavior than that with L-alanine directly linked to the naphthalimido moiety (1a). As a result, a highly thermostable organogel of 1b with a unique core-shell structure was obtained at high temperature and pressure in acetonitrile. Moreover, the gels of 1a and 1b could undergo an instantaneous gel-to-gel transition triggered by sonication. Ultrasound could break the core-shell microsphere of 1b and the micelle structure of 1a into entangled fibers. By studying the mechanism of the sonication-triggered gel-to-gel transition process of these compounds, it can be concluded that ultrasound has a variety of effects on the morphology, such as cutting, knitting, unfolding, homogenizing, and even cross-linking. Typically, ultrasound can cleave and homogenize pi-stacking and hydrophobic interactions among the gel molecules and then reshape the morphologies to form a new gel. This mechanism of morphology transformation triggered by sonication might be attractive in the field of material storage and controlled release. PMID:20572172

Yu, Xudong; Liu, Qian; Wu, Junchen; Zhang, Mingming; Cao, Xinhua; Zhang, Song; Wang, Qi; Chen, Liming; Yi, Tao

2010-08-01

385

Optimization of the mineral content in polymeric gels: The effect of calcium to phosphate molar ratio  

NASA Astrophysics Data System (ADS)

The influence of calcium to phosphate (Ca/P) molar ratio on the extent of mineralization in a model (poly)acrylamide gel was investigated under simulated physiological conditions. We hypothesized that the optimal growth of hydroxyapatite crystals will take place at the stoichiometric Ca/P molar ratio of 1.67. Phosphate ions were incorporated during the polymerization of the gel and mineralization was initiated by submersion of the gel in calcium acetate solution. Ca/P molar ratios were varied in the range of 0.5-5.0. The mineralized gel was characterized by Raman spectroscopy, scanning electron microscopy (SEM) and mineral weight fraction analysis via ashing. Raman spectra captured across the bulk of the gels indicated the presence of mineral at the core section. The phosphate symmetric stretching peak was observed in the range of 955-960 cm -1 which is characteristic of hydroxyapatite. SEM images showed that crystals formed at Ca/P=2.0 were denser and larger in size than at other molar ratios. In agreement with SEM images, the dry weight fraction of mineral reached the maximum at the molar ratio of 2.0 and the extent of mineralization rapidly declined as the molar ratio diverged from 2.0. Also, the crystallinity of the mineral was optimum at the molar ratio of 2.0. Thus it appears that for effective mineralization, the molar ratio of the two ions needs to be in excess of the stoichiometric requirement, suggesting that ions are expended in processes other than the formation and growth of hydroxyapatite crystals. Therefore, the optimal level of mineralization in biomimetic-based growth of calcium phosphate crystals in sol-gel environment requires consideration of a range of molar ratios as opposed to using the molar ratios corresponding to that of the crystal species intended to grow.

Das, Prasenjit; Akkus, Ozan; Azad, Abdul-Majeed

2005-07-01

386

The structure of high-methoxyl sugar acid gels of citrus pectin as determined by AFM.  

PubMed

Images of native high-methoxyl sugar acid gels (HMSAGs) were obtained by atomic force microscopy (AFM) in the Tapping Mode. Electronic thinning of the pectin strands to one-pixel wide allowed the pectin network to be viewed in the absence of variable strand widths related to preferentially solvated sugar. Thinned images revealed that HMSAGs of pectin comprise a partially cross-linked network, in that many of the cross-linking moieties are attached at only one end. Based on their structural similarities, aggregated pectin in water appears to be a fluid precursor of a HMSAG of pectin. Furthermore, examination of AFM images revealed that gels with 'uniform' distribution of strands and pores between strands had higher gel strengths than gels in which strands were non-uniformly distributed and were separated by large and small spaces. PMID:19111283

Fishman, Marshall L; Cooke, Peter H

2009-09-28

387

Cross-Language Perception of Cantonese Vowels Spoken by Native and Non-Native Speakers  

ERIC Educational Resources Information Center

This study examined the effect of native language background on listeners' perception of native and non-native vowels spoken by native (Hong Kong Cantonese) and non-native (Mandarin and Australian English) speakers. They completed discrimination and an identification task with and without visual cues in clear and noisy conditions. Results…

So, Connie K.; Attina, Virginie

2014-01-01

388

Native American Studies Page 211Sonoma State University 2014-2015 Catalog NATIVE AMERICAN STUDIES  

E-print Network

Native American Studies Page 211Sonoma State University 2014-2015 Catalog NATIVE AMERICAN STUDIES COORDINATOR Linnea Mullins - (707) 664-2486 Faculty Gregory Sarris / Native American Literature; Endowed Chair Native American Studies Ashley Hall, Adjunct Faculty Program Offered Minor in Native American Studies

Ravikumar, B.

389

Characterization of rehydrated gelatin gels.  

PubMed

Five percent glutaraldehyde cross-linked gels have shown excellent blood compatibility as coatings for cardiac prostheses. A method was developed for producing thin dehydrated coatings using a proprietary dehydration procedure and ethylene oxide (EO) sterilization. The swollen surfaces of rehydrates versus wet (original) gels were compared. Within 30 min of saline rehydration, dry 30-50-microns films on textured surfaces became smooth, uniform, and comparable to original gelatin gels. Mechanical test results after rehydration showed values for strain remain unchanged (39.3 + 10.0 to 40.0 + 7.8%), but stress increased (2.79 + 1.21 to 4.22 + 1.60 dyne/cm2; p less than 0.01). The contact angle data reported gamma C values of 26.1 and 30.4 dyne/cm for original and rehydrated gels. Using a coulometric titrimeter, the measured water content of original gels was reduced from 85 to 3.4% after drying. Dried and saline rehydrated gels had a 73.2% moisture content. Gels shrank 8.8% of their original length after rehydration; however, the thickness of all pump coatings remained stable. Two-hour incubations with bovine platelet rich plasma showed no differences in platelet reactivity or morphology when compared to original gels. Light microscopy and scanning electron microscopy (SEM) showed no evidence of gel cracking or surface defects after pump endurance testing for 3 and 5 weeks. The process of dehydration eliminates the wet storage and sterility problems of such hydrogels and provides a stable film coating for a variety of blood-contacting substrates. PMID:1998488

Emoto, H; Kambic, H; Chen, J F; Nosé, Y

1991-02-01

390

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.

1999-01-01

391

Adhesive, elastomeric gel impregnating composition  

DOEpatents

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.

Shaw, David Glenn (Tucson, AZ); Pollard, John Randolph (Tucson, AZ); Brooks, Robert Aubrey (Tijeras, NM)

2002-01-01

392

The Native American healing experience.  

PubMed

Recovery from addiction to alcohol and other drugs is taking place with the assistance of culture-specific methods in American Indian and Alaska Native communities in North America. These communities utilize many of the recovery approaches that make up today's best practices, but they also use their own cultural and ethnic strengths as an important part of their addictions recovery. The Wellbriety Movement among Native people is one such expression of culture-specific healing for North Americans having the heritage of indigenous peoples. The rallying call, "Our culture is prevention," expresses an approach unique in addictions recovery processes anywhere. PMID:19016172

Coyhis, Don; Simonelli, Richard

2008-01-01

393

Interactive Effects Of Non-Native Predators And Anthropogenic Habitat Alterations On Native Juvenile Salmon.  

E-print Network

??Multiple human stressors including non-native species and habitat alterations can interact with complex consequences on native species. Human-modified habitats can change non-native predator functional and… (more)

Sabal, Megan Christine

2014-01-01

394

Indian Education - Curriculum Development: Native Languages, Native Studies.  

ERIC Educational Resources Information Center

Brief program descriptions derived from a cross-Canada survey of current enrichment programs and teaching materials for Native Studies programs are presented in this document. Prices for materials and some funding sources are also presented. Brief paragraphs describe on-going programs in each of the following subject areas: art (5 programs);…

Department of Indian Affairs and Northern Development, Toronto (Ontario). Education Div.

395

Application of chitosan/polyacrylamide nanofibres for removal of chromate and phosphate in water  

NASA Astrophysics Data System (ADS)

Water pollution is an intractable environmental problem in South Africa. Management of the water resource is vital in order to address the water scarcity issues. Research on remediation of contaminated water has focused mainly on the removal of heavy metals such as Pb, Cd, Zn, Hg and Cu and neglected other inorganic pollutants. In this work we focus on the removal of anions, namely chromate and phosphate. Chromium is extensively used in the textile, leather and metallurgy industries and contaminates surface water and groundwater when inadequately treated industrial effluents are discharged. Chromium has been associated with irregular sugar metabolism, nosebleeds and ulcers, and it is also carcinogenic. The phosphate ion is an essential micronutrient responsible for healthy plant growth. However, excess phosphate intake stimulates rapid growth of photosynthetic algae and cyanobacteria, resulting in eutrophication. This phenomenon (algal bloom) causes other organisms to die due to reduced oxygen in the water. In order to offer remediation measures, this study reports the use of electrospun nanofibres for the removal of chromate and phosphate anions. Adsorption experiments were carried out using nanofibres electrospun from chitosan and polyacrylamide polymer blends, cross-linked with glutaraldehyde. Quantification of chromium was done using ICP-OES while UV-Vis spectrophotometry was used for the determination of phosphates. Batch adsorption experiments were done to determine optimum adsorption parameters such as pH, contact time, temperature and initial analyte concentration. Removal of the ions using a flow-adsorption technique through a micro-column was performed. The experimental data obtained were analysed using Langmuir and Freundlich models to study the adsorption mechanisms. The nanofibres had an adsorption capacity for Cr(VI) and PO43- of 0.26 mg g-1 and 392 mg g-1, respectively, and removal efficiencies of 93% and 97.4%, in the same order, in synthetic water samples and environmental water samples. It was observed that both chromium(VI) and phosphate adsorption followed pseudo-second-order kinetics. During the regeneration process, it was established that Cr(VI) was reduced to Cr(III) at the surface of the sorbent. This reaction offers the advantage of reducing the toxicity of chromium(VI) in water. The results of this work have potential applications in the removal of these anions in contaminated drinking water thus improving its quality for human consumption.

Nthumbi, Richard M.; Catherine Ngila, J.; Moodley, Brenda; Kindness, Andrew; Petrik, Leslie

396

Polyacrylamide hydrogels: an effective tool for delivering liquid baits to pest ants (Hymenoptera: Formicidae).  

PubMed

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

Buczkowski, Grzegorz; Roper, Elray; Chin, Darren

2014-04-01

397

Colloidal gels: Clay goes patchy  

NASA Astrophysics Data System (ADS)

Empty liquids and equilibrium gels have so far been only theoretical possibilities, predicted for colloids with patchy interactions. But evidence of both has now been found in Laponite, a widely studied clay.

Kegel, Willem K.; Lekkerkerker, Henk N. W.

2011-01-01

398

Self polymerising ionic liquid gel.  

PubMed

A novel self-polymerised ionic liquid (IL) gel was prepared at room temperature (RT), without light or heat or addition of initiator, using a new IL, choline formate (CF), and 2-hydroxyethyl methacrylate (HEMA). PMID:19462080

Winther-Jensen, Orawan; Vijayaraghavan, R; Sun, Jiazeng; Winther-Jensen, Bjorn; MacFarlane, Douglas R

2009-06-01

399

A conjugated polymer plastic gel  

E-print Network

We present a gel route to process highly oriented conjugated polymer films and fibers. The incorporation of hexafluoroisopropanol, a strong and stable dipolar group, to the polythiophene backbone enhances the solubility ...

Alcazar Jorba, Daniel

2008-01-01

400

Raft Instability of Biopolymer Gels  

E-print Network

Following recent X-ray diffraction experiments by Wong, Li, and Safinya on biopolymer gels, we apply Onsager excluded volume theory to a nematic mixture of rigid rods and strong ``$\\pi/2$'' cross-linkers obtaining a long-ranged, highly anisotropic depletion attraction between the linkers. This attraction leads to breakdown of the percolation theory for this class of gels, to breakdown of Onsager's second-order virial method, and to formation of heterogeneities in the form of raft-like ribbons.

I. Borukhov; R. F. Bruinsma

2002-09-13

401

TOPICAL REVIEW: Polymer gel dosimetry  

Microsoft Academic Search

Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. These gel dosimeters, with the capacity to uniquely record the radiation dose distribution in three-dimensions (3D), have specific advantages when compared to one-dimensional dosimeters, such as ion chambers, and two-dimensional dosimeters, such as film. These advantages are particularly significant

C. Baldock; Y. De Deene; S. Doran; G. Ibbott; A. Jirasek; M. Lepage; K. B. McAuley; M. Oldham; L. J. Schreiner

2010-01-01

402

Census Data and Native Americans.  

ERIC Educational Resources Information Center

Designed for those seeking data on Native Americans, this paper presents U.S. census data sources and the developments which have taken place in data collection procedures and definitions between 1860 and 1970. Specifically, this paper presents: (1) development of race concept and definitions (emphasis on American Indian, Aleut and Eskimo, and…

McKenney, Nampeo D. R.; Crook, Karen A.

403

Rethinking Native American Language Revitalization  

ERIC Educational Resources Information Center

As many linguists continue to work with and analyze First Nations/Native American languages, the consensus opinion usually direly predicts the loss of daily use for almost all of the extant Indigenous languages. Tremendous efforts are being expended for renewing, revitalizing, and restoring these languages to everyday use. The model upon which…

White, Frederick

2006-01-01

404

Issues in Native American Archives  

Microsoft Academic Search

Native American communities face extreme challenges in the archival preservation of their historical documents. For many tribal repositories, a lack of funding, insufficient archival training, and the lack of clear collection development have meant that critical documentation of the tribal historical record is at risk. This paper describes the author's 1998 summer internship at the Hatathli Museum at Dine College

Amy Cooper

2003-01-01

405

Native Birthrights and Indigenous Science  

ERIC Educational Resources Information Center

In traditional tribal cultures, children are treated with great respect and eagerly learn from their elders. But in contemporary Western society, Native students have the highest dropout rates and are subjected to disproportionate school disciplinary exclusion, which becomes a pipeline into the justice system (Sprague, Vincent, Tobin, & Pavel,…

James, Adrienne Brant; Lunday, Tammy

2014-01-01

406

Amphoteric native defects in semiconductors  

SciTech Connect

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.

Walukiewicz, W.

1989-05-22

407

Native Americans in Public Health.  

ERIC Educational Resources Information Center

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…

Westberg, Jane

2003-01-01

408

Amyloidogenesis of Natively Unfolded Proteins  

PubMed Central

Aggregation and subsequent development of protein deposition diseases originate from conformational changes in corresponding amyloidogenic proteins. The accumulated data support the model where protein fibrillogenesis proceeds via the formation of a relatively unfolded amyloidogenic conformation, which shares many structural properties with the pre-molten globule state, a partially folded intermediate first found during the equilibrium and kinetic (un)folding studies of several globular proteins and later described as one of the structural forms of natively unfolded proteins. The flexibility of this structural form is essential for the conformational rearrangements driving the formation of the core cross-beta structure of the amyloid fibril. Obviously, molecular mechanisms describing amyloidogenesis of ordered and natively unfolded proteins are different. For ordered protein to fibrillate, its unique and rigid structure has to be destabilized and partially unfolded. On the other hand, fibrillogenesis of a natively unfolded protein involves the formation of partially folded conformation; i.e., partial folding rather than unfolding. In this review recent findings are surveyed to illustrate some unique features of the natively unfolded proteins amyloidogenesis. PMID:18537543

Uversky, Vladimir N.

2009-01-01

409

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....

410

Surface grafted chitosan gels. Part II. Gel formation and characterization.  

PubMed

Responsive biomaterial hydrogels attract significant attention due to their biocompatibility and degradability. In order to make chitosan based gels, we first graft one layer of chitosan to silica, and then build a chitosan/poly(acrylic acid) multilayer using the layer-by-layer approach. After cross-linking the chitosan present in the polyelectrolyte multilayer, poly(acrylic acid) is partly removed by exposing the multilayer structure to a concentrated carbonate buffer solution at a high pH, leaving a surface-grafted cross-linked gel. Chemical cross-linking enhances the gel stability against detachment and decomposition. The chemical reaction between gluteraldehyde, the cross-linking agent, and chitosan was followed in situ using total internal reflection Raman (TIRR) spectroscopy, which provided a molecular insight into the complex reaction mechanism, as well as the means to quantify the cross-linking density. The amount of poly(acrylic acid) trapped inside the surface grafted films was found to decrease with decreasing cross-linking density, as confirmed in situ using TIRR, and ex situ by Fourier transform infrared (FTIR) measurements on dried films. The responsiveness of the chitosan-based gels with respect to pH changes was probed by quartz crystal microbalance with dissipation (QCM-D) and TIRR. Highly cross-linked gels show a small and fully reversible behavior when the solution pH is switched between pH 2.7 and 5.7. In contrast, low cross-linked gels are more responsive to pH changes, but the response is fully reversible only after the first exposure to the acidic solution, once an internal restructuring of the gel has taken place. Two distinct pKa's for both chitosan and poly(acrylic acid), were determined for the cross-linked structure using TIRR. They are associated with populations of chargeable groups displaying either a bulk like dissociation behavior or forming ionic complexes inside the hydrogel film. PMID:25006685

Liu, Chao; Thormann, Esben; Claesson, Per M; Tyrode, Eric

2014-07-29

411

Pre-Cast Gel Electrophoresis Guide  

E-print Network

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

Kirschner, Marc W.

412

Visualization of barley beta-glucan degrading isozymes after gel isoelectric focusing.  

PubMed

A simple method to study the polymorphism of barley (Hordeum vulgare L.) beta-(1-3,1-4)-glucanases (specific enzymes of barley beta-glucan hydrolysis) is described. Proteins of a crude extract of germinated barley kernels were separated in an immobilized pH gradient in two pH ranges (pH 3-10.5 and pH 4-7). beta-glucanases were visualized by contact printing with a polyacrylamide gel containing beta-glucan or lichenan. Patterns of beta-glucanases were revealed by staining with Congo Red with resultant clear zones on a stained background. Various conditions of germination, extraction and visualization were investigated. New isozyme bands could be detected and their nature and origin discussed. PMID:7498123

Menteur, S; Jestin, L; Risacher, T; Branlard, G

1995-06-01

413

Eagle Feather Tutoring Native American Cultural Center  

E-print Network

Eagle Feather Tutoring Native American Cultural Center LSC West� Mac Gym Colorado State University NativeAmericanCulturalCenter(8013) ColoradoStateUniversity LSCWest�MACGym FortCollins,CO80523-8016 LSC

Collett Jr., Jeffrey L.

414

Diabetes in American Indians and Alaska Natives  

MedlinePLUS

... 1 of 2 Diabetes in American Indians and Alaska Natives Facts At-a-Glance In response to the diabetes epidemic in American Indian and Alaska Native people, Congress established the Special Diabetes Program ...

415

Healthy Native Babies Project: Honoring the Past,  

E-print Network

Healthy Native Babies Project: Honoring the Past, Learning for the Future Facilitator's Guide for 2-Hour Training A Collaboration Between the Healthy Native Babies Project Workgroup and the Eunice..............................................................................................................2 HOW TO USE THIS TRAINING

Rau, Don C.

416

Healthy Native Babies Project: Honoring the Past,  

E-print Network

Healthy Native Babies Project: Honoring the Past, Learning for the Future Facilitator's Guide for 1-Day Training A Collaboration Between the Healthy Native Babies Project Workgroup and the Eunice........................................................................................................................3 HOW TO USE THIS TRAINING

Rau, Don C.

417

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 ...

418

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 ...

419

Native Hawaiian & Other Pacific Islander Populations  

MedlinePLUS

... Other Pacific Islander individuals in the United States. States with the largest Native Hawaiian or Other Pacific Islander populations in 2011 were Hawaii (359,000) and California (329,000) . The Native ...

420

Use of Native American Healers Among Native American Patients in an Urban Native American Health Center  

Microsoft Academic Search

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

Anne M. Marbella; Mickey C. Harris; Sabina Diehr; Gerald Ignace; Georgianna Ignace

1998-01-01

421

Gel Formation of Recombinant Fibrinogen Lacking ?C Termini  

NASA Astrophysics Data System (ADS)

In order to examine the role of ?C domains, especially the terminal region of it, of fibrinogen A? chain in the fibrin gel formation, we prepared a recombinant fibrinogen, A?570 fibrinogen. A?570 fibrinogen is the fibrinogen that is truncated at A?570 and lacks 40 amino acids at the terminus of the ?C domain. We examined the thrombin-catalyzed polymerization by transmission spectroscopy and confocal laser scanning microscopy (CLSM). We found that A?570 fibrinogen exhibited a significantly delayed aggregation showing the importance of the terminal region of the ?C domain in the polymerization process. Contrary to the fact that the addition of glucose to the mixture of fibrinogen and thrombin results in a substantial delay of the lateral aggregation of protofibrils for the native fibrinogen, delaying effect due to the addition of glucose disappeared thoroughly in the case of A?570 fibrinogen. Turbidity measurements dependent upon the wavelength in the time course of gelation showed that mass per unit fiber length of A?570 fibrinogen decreased significantly compared to the native fibrinogen, and the lateral aggregation of protofibrils was hindered significantly. Those results are consistent with the CLSM measurements that the bundles of protofibrils of A?570 fibrinogen are thinner and denser with more branching than those of the native one. It was confirmed that C-terminal region of the ?C domain plays an important role in the lateral aggregation and glucose interferes the interacting process between the ?C domains.

Kuboa, Kenji; Masuda, Yuka; Toyama, Yoshiharu; Nameki, Nobukazu; Okumura, Nobuo; Ochiai, Masanori

422

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

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.

Gonzalo G. Palazolo; Delia A. Sorgentini; Jorge R. Wagner

2004-01-01

423

Native American Children in Michigan. [Executive Summary  

ERIC Educational Resources Information Center

"Native American Children in Michigan," provides a historical context for the tenuous relationship between Michigan's 12 federally recognized tribes and the state government, paying particular attention to the erosion of Native American education programs and the disproportionate number of Native children who find themselves in both the child…

W. K. Kellogg Foundation, 2012

2012-01-01

424

NATIVE AMERICAN HISTORY Libby R. Tronnes  

E-print Network

NATIVE AMERICAN HISTORY Libby R. Tronnes Overviews Deloria, Philip, ed., A Companion to American. "The Indian's Old World: Native Americans and the Coming of Europeans." William and Mary Quarterly in Native American Communities (1995) Dowd, Gregory Evans. A Spirited Resistance: The North American Indian

Wisconsin at Madison, University of

425

Eagle Feather Tutoring Native American Cultural Center  

E-print Network

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.S.Postage,PAID FortCollins,CO PermitNo.19 NativeAmericanCulturalCenter(8013) ColoradoStateUniversity 218Lory

Stephens, Graeme L.

426

Eagle Feather Tutoring Native American Cultural Center  

E-print Network

Eagle Feather Tutoring Native American Cultural Center 218 Lory Student Center Colorado State the NACC office at 491-1332. NonProfitOrg. U.S.Postage,PAID FortCollins,CO PermitNo.19 NativeAmerican Feather Tutoring Program Native American Cultural Center NACC #12;

427

Eagle Feather Tutoring Native American Cultural Center  

E-print Network

Eagle Feather Tutoring Native American Cultural Center LSC West­ Mac Gym Colorado State University, and kinship with all living things" -Author Unknown Native American Cultural Center NACC #12;The Eagle Feather.S.Postage,PAID FortCollins,CO PermitNo.19 NativeAmericanCulturalCenter(8013) ColoradoStateUniversity LSCWest

Stephens, Graeme L.

428

Generating Textures of New Zealand Native Wood  

E-print Network

1 Generating Textures of New Zealand Native Wood Jack Wang Abstract - This report explores algorithms for computer generated textures simulating New Zealand native wood, we out line procedural and Ray tracing. The main goal of this research is to study New Zealand native wood in depth and to gather

Goodman, James R.

429

Canadian Journal of Native Studies: An Assessment.  

ERIC Educational Resources Information Center

Describes and critically analyzes volume of "Canadian Journal of Native Studies" (v4 n2 1984). Sketches journal's history and critiques three articles. Article topics include history (Indian treaties and Indian policy administration); resource development impacts (reserve land flooding, native health, and fishing); and native education (case…

Price, Richard T.

1987-01-01

430

Bill Demmert and Native Education in Alaska  

ERIC Educational Resources Information Center

This article describes the influences of William Demmert's formative years growing up in Alaska and his years as an educator of Native American students upon his career in Native education policy. It focuses on Alaska Native education during a ten-year period between 1980 and 1990 during which time he served as the director of the Center for…

Barnhardt, Ray

2011-01-01

431

Palatability and nutritive value of native legumes  

Microsoft Academic Search

Native perennial legumes have potential for use as components of grazing systems. Palatability affects forage utilization by grazing livestock, but relative palatability of native legumes is unknown. We determined the palatability of these native legumes of the Fabaceae family based on relative leaf consumption: false indigo (Amorpha fruticosa L.), Illinois bundleflower (Desmanthus illinoensis (Michx.) MacMill. ex B.L. Rob. & Fernald),

Donald L Wyse Craig C Sheaffer; Nancy J Ehlke

2009-01-01

432

The State of Native American Youth Health.  

ERIC Educational Resources Information Center

This survey on the health status of Native American adolescents living on or near reservations was completed by 14,000 American Indian and Alaska Native youths from 50 tribes attending 200 schools in 12 states. Results indicate that most Native teenagers felt their family cared about them a great deal, and many would go to a family member first…

Minnesota Univ., Minneapolis. Div. of General Pediatrics and Adolescent Health.

433

Encountering Complexity: Native Musics in the Curriculum.  

ERIC Educational Resources Information Center

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)

Boyea, Andrea

1999-01-01

434

Native Education: The Next 100 Years.  

ERIC Educational Resources Information Center

This paper discusses the history and trauma of Native education in Canada and stresses the importance of integrating the best of the Native culture with the best of the Western culture in future Native education. The paper is organized in three parts. The first section acknowledges the trauma inflicted on the indigenous peoples by means of early…

Atleo, E. R.

435

The Native American Fish & Wildlife Society.  

ERIC Educational Resources Information Center

The Native American Fish & Wildlife Society helps over 200 tribes and Alaska Native villages implement best management practices, informs them about wildlife issues, provides hazardous materials training, trains game wardens, and conducts a summer practicum for Native youth on environmental issues and careers in natural resource fields.…

Walsh, Patricia

2002-01-01

436

Native American Studies Major Major Advisors  

E-print Network

Native American Studies Major Major Advisors Laura Jimenez-Olvera & Dewey St. Germaine 532 & 530://ethnicstudies.berkeley.edu/ Undergraduate Program The Native American Studies Program exists to broaden the understanding of students interested in the history, culture, and contemporary situations of Native Americans in the United States

Walker, Matthew P.

437

10 CFR 440.11 - Native Americans.  

...2014-01-01 2014-01-01 false Native Americans. 440.11 Section 440.11 Energy...LOW-INCOME PERSONS § 440.11 Native Americans. (a) Notwithstanding any other...population of all low-income Native Americans for whom a determination under...

2014-01-01

438

Native Americans and Wage Labor: Ethnohistorical Perspectives.  

ERIC Educational Resources Information Center

This book reconsiders a largely ignored fact of North American Indian economic life--the place of wage labor in the culture and history of Native Americans. Case studies examine social networks of Native agricultural laborers, the decline of Native communities from self-sufficient producers to lower-class wage laborers, vocational education in…

Littlefield, Alice, Ed.; Knack, Martha C., Ed.

439

English and Native Languages: Integration Not Competition.  

ERIC Educational Resources Information Center

Describes the discussion and recommendations of the March 1982 Symposium on Language Development for Native Peoples. Focuses on why TESL Canada advocates not only good English as a second language and standard English as a second dialect teaching in Native education, but also relevant, effective Native language teaching. (NEC)

Burnaby, Barbara

1984-01-01

440

Flocculation of both anionic and cationic dyes in aqueous solutions by the amphoteric grafting flocculant carboxymethyl chitosan-graft-polyacrylamide.  

PubMed

In the current work, a series of amphoteric grafting chitosan-based flocculants (carboxymethyl chitosan-graft-polyacrylamide, denoted as CMC-g-PAM) was designed and prepared successfully. The flocculants were applied to eliminate various dyes from aqueous solutions. Among different graft copolymers, CMC-g-PAM11 with a PAM grafting ratio of 74% demonstrated the most efficient performance for removal of both the anionic dye (Methyl Orange, MO) and the cationic dye (Basic Bright Yellow, 7GL) under the corresponding favored conditions (80 mg/L of the flocculant at pH 4.0, and 160 mg/L at pH 11.0). In comparison with its precursors, chitosan and carboxymethyl chitosan, CMC-g-PAM11 showed higher removal efficiencies and wider flocculation windows. More importantly, the graft copolymer produced notably more compacted flocs based on image analysis in combination with fractal theory, which was of great significance in practical water treatment. Furthermore, the flocculation mechanism was discussed in detail. The grafted polyacrylamide chains were found to contribute much to the improved bridging and sweeping flocculation effects, but reduced charge neutralization flocculation for the effect of charge screening. PMID:23583947

Yang, Zhen; Yang, Hu; Jiang, Ziwen; Cai, Tao; Li, Haijiang; Li, Haibo; Li, Aimin; Cheng, Rongshi

2013-06-15

441

Polyacrylamide hydrogel pulmonary embolism--A fatal consequence of an illegal cosmetic vaginal tightening procedure: A case report.  

PubMed

Vaginal tightening is a kind of esthetic surgery aimed at enhancing sexual satisfaction during intercourse. Although the injective vaginal tightening procedure is informal, there are already some reports of its application. But pulmonary embolism is a really rare therapeutic complication of this procedure. We report a case of death due to the non-thrombotic pulmonary embolism as a consequence of illegal cosmetic vaginal-tightening procedure using polyacrylamide hydrogel. A 34-year-old woman was hospitalized with paroxysmal abdominal cramps and diarrhea as initial symptoms, while she concealed the genital cosmetic surgery history. Respiratory distress presented only 1.5h before she died. The result of autopsy revealed the cause of death as pulmonary embolism due to the hydrogel which was injected into her vaginal wall. The emboli were confirmed as polyacrylamide hydrogel by Alcian-blue stain and the Fourier transform infrared scanning. It is suggested that pulmonary embolism should not be discarded in the expertise of deaths following cosmetic implant surgeries. It broadens our understanding about death associated with esthetic genital procedures and informs clinicians and medical examiners of the potential death of this type. And detailed investigations of previous medical and surgical history will always play a critical role in the certification of cause of death. PMID:24656776

Duan, Yijie; Zhang, Lin; Li, Shangxun; Yang, Yi; Xing, Jingjun; Li, Wenhe; Wang, Xinmei; Zhou, Yiwu

2014-05-01

442

Capillary fracture of soft gels  

E-print Network

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 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 $L\\propto t^{3/4}$. 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 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 impo...

Bostwick, Joshua B

2013-01-01

443

Capillary fracture of soft gels  

E-print Network

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 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 $L\\propto t^{3/4}$. 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 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.

Joshua B. Bostwick; Karen E. Daniels

2013-10-16

444

OKLAHOMA NATIVE AMERICAN YOUTH LANGUAGE FAIR Song in Native American Language  

E-print Network

OKLAHOMA NATIVE AMERICAN YOUTH LANGUAGE FAIR Song in Native American Language Category Description Students are invited to perform in songs in Native American languages, and be accompanied by music if needed. Please remember that the point of the ONAYLF is to demonstrate Native American language use

Oklahoma, University of

445

Positive relationship between non-native and native squirrels in an urban landscape  

Microsoft Academic Search

Paradoxically, non-native species sometimes displace native species that appear to be well adapted to local land- scapes. That many landscapes have been altered by humans, creating habitat suitable for non-native species, helps explain this apparent paradox. We asked whether the abundance of native Douglas (Tamiasciurus douglasii (Bachman, 1839)) and northern flying (Glaucomys sabrinus (Shaw, 1801)) squirrels was best explained by

E. K. Gonzales; Y. F. Wiersma; A. I. Maher; T. D. Nudds

2008-01-01

446

Native American Support Programs Task Force Changing Winds: Service to Native American Students  

E-print Network

Native American Support Programs Task Force Changing Winds: Service to Native American Students and Communities in Montana Final Report of the MSU Native American Support Programs Task Force Submitted To Shelly Hogan #12;Native American Support Programs Task Force Contents EXECUTIVE SUMMARY

Dyer, Bill

447

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

Federal Register 2010, 2011, 2012, 2013

...DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT [Docket No...Native American, Alaska Native and Native Hawaiian Housing Needs...below to the Office of Management and Budget (OMB) for review, in...people who are at least 50% blood quantum Native Hawaiian) and are...

2013-12-11

448

Native Plants of Montara Mountain  

NSDL National Science Digital Library

It is always inspiring to find websites that have been created by a committed individual who is passionate about the site's subject. Developed by naturalist Chuck Kozak, Native Plants of Montara Mountain is just that type of website. Mr. Kozak has assembled a nice online field guide of plants native to Montara Mountain, a northern spur of California's Santa Cruz Mountains. The guide organizes plants by Family and Scientific name, Common name, or Color and Type. Site visitors can also find plants by using the alphabetically organized Master Index. The numerous plant entries include clear photos and brief descriptions. Although the website focuses on the flora of a specific area, many of these plants can be found in other geographic regions as well. This site is also reviewed in the September 3, 2004 _NSDL Life Sciences Report_.

449

Free classification of American English dialects by native and non-native listeners  

PubMed Central

Most second language acquisition research focuses on linguistic structures, and less research has examined the acquisition of sociolinguistic patterns. The current study explored the perceptual classification of regional dialects of American English by native and non-native listeners using a free classification task. Results revealed similar classification strategies for the native and non-native listeners. However, the native listeners were more accurate overall than the non-native listeners. In addition, the non-native listeners were less able to make use of constellations of cues to accurately classify the talkers by dialect. However, the non-native listeners were able to attend to cues that were either phonologically or sociolinguistically relevant in their native language. These results suggest that non-native listeners can use information in the speech signal to classify talkers by regional dialect, but that their lack of signal-independent cultural knowledge about variation in the second language leads to less accurate classification performance. PMID:20161400

Clopper, Cynthia G.; Bradlow, Ann R.

2009-01-01

450

Production and Perception of Temporal Patterns in Native and Non-Native Speech  

PubMed Central

Two experiments examined production and perception of English temporal patterns by native and non-native participants. Experiment 1 indicated that native and non-native (L1 = Chinese) talkers differed significantly in their production of one English duration pattern (i.e., vowel lengthening before voiced versus voiceless consonants) but not another (i.e., tense versus lax vowels). Experiment 2 tested native and non-native listener identification of words that differed in voicing of the final consonant by the native and non-native talkers whose productions were substantially different in experiment 1. Results indicated that differences in native and non-native intelligibility may be partially explained by temporal pattern differences in vowel duration although other cues such as presence of stop releases and burst duration may also contribute. Additionally, speech intelligibility depends on shared phonetic knowledge between talkers and listeners rather than only on accuracy relative to idealized production norms. PMID:18679042

Bent, Tessa; Bradlow, Ann R.; Smith, Bruce L.

2012-01-01

451

Copolymers For Capillary Gel Electrophoresis  

DOEpatents

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.

Liu, Changsheng (State College, PA); Li, Qingbo (State College, PA)

2005-08-09

452

MSU REQUEST FOR PROPOSALS-NATIVE AMERICAN RECRUITMENT & RETENTION INITIATIVES  

E-print Network

MSU REQUEST FOR PROPOSALS- NATIVE AMERICAN RECRUITMENT & RETENTION INITIATIVES The Office to Native American students and their communities. Further, MSU seeks to build stronger partnerships with Native Communities and increase collaboration among campus-wide programs that support Native Americans

Maxwell, Bruce D.

453

Statistical physics of polymer gels  

NASA Astrophysics Data System (ADS)

This work presents a comprehensive analysis of the statistical mechanics of randomly cross-linked polymer gels, starting from a microscopic model of a network made of instantaneously cross-linked Gaussian chains with excluded volume, and ending with the derivation of explicit expressions for the thermodynamic functions and for the density correlation functions which can be tested by experiments. Using replica field theory we calculate the mean field density in replica space and show that this solution contains statistical information about the behavior of individual chains in the network. The average monomer positions change affinely with macroscopic deformation and fluctuations about these positions are limited to length scales of the order of the mesh size. We prove that a given gel has a unique state of microscopic equilibrium which depends on the temperature, the solvent, the average monomer density and the imposed deformation. This state is characterized by the set of the average positions of all the monomers or, equivalently, by a unique inhomogeneous monomer density profile. Gels are thus the only known example of equilibrium solids with no long-range order. We calculate the RPA density correlation functions that describe the statistical properties of small deviations from the average density, due to both static spatial heterogeneities (which characterize the inhomogeneous equilibrium state) and thermal fluctuations (about this equilibrium). We explain how the deformation-induced anisotropy of the inhomogeneous equilibrium density profile is revealed by small angle neutron scattering and light scattering experiments, through the observation of the butterfly effect. We show that all the statistical information about the structure of polymer networks is contained in two parameters whose values are determined by the conditions of synthesis: the density of cross-links and the heterogeneity parameter. We find that the structure of instantaneously cross-linked gels becomes increasingly inhomogeneous with the approach to the cross-link saturation threshold at which the heterogeneity parameter diverges. Analytical expressions for the correlators of deformed gels are derived in both the long wavelength and the short wavelength limits and an exact expression for the total static structure factor, valid for arbitrary wavelengths, is obtained for gels in the state of preparation. We adapt the RPA results to gels permeated by free labelled chains and to gels in good solvents (in the latter case, excluded volume effects are taken into account exactly) and make predictions which can be directly tested by scattering and thermodynamic experiments. Finally, we discuss the limitations and the possible extensions of our work.

Panyukov, Sergei; Rabin, Yitzhak

1996-05-01

454

Tracer diffusion in colloidal gels  

E-print Network

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.

Sujin Babu; Jean Christophe Gimel; Taco Nicolai

2007-05-09

455

In-gel derivatization of proteins for cysteine-specific cleavages and their analysis by mass spectrometry.  

PubMed

As a potential tool for proteomics and protein characterization, in-gel cysteine- and arginine-specific cleavage is demonstrated by means of trypsin or endoproteinase Lys-C for six model proteins (lysozyme, alpha-lactalbumin, beta-lactoglobulin, ribonuclease A, albumin, and transferrin), ranging in size from 14 kDa to 79 kDa. Chemical modifications of cysteine (aminoethylation with bromoethylamine or N-(iodoethyl)-trifluoroacetamide, and subsequent guanidination) and lysine (acetylation) prior to tryptic digestion releases peptides delineated by cysteine or arginine residues. Peptide products are analyzed by MALDI-TOF-MS, ESI-MS, and ESI- and MALDI-MS/MS (with a quadrupole time-of-flight instrument). Complications induced by acrylamide alkylations of cysteines were avoided by substituting lower pH bis-tris polyacrylamide gels for tris-glycine. Sequence coverages from 35 to 86% were obtained and amino acid compositions of generated peptides could be confirmed by comprehensive y- and b-ion series. Detailed information about, in particular, cysteine rich proteins after gel electrophoresis were obtained. The chemistries for modification and cleavage specificities at cysteine residues provide an alternative means to characterize and identify proteins separated by gel electrophoresis. PMID:12716130

Thevis, Mario; Ogorzalek Loo, Rachel R; Loo, Joseph A

2003-01-01

456

A Case of Foreign-Body Granuloma of the Glabella due to Polyacrylamide Filler and an Intractable Ulcer after Skin Biopsy: An Immunohistochemical Evaluation of Inflammatory Changes  

PubMed Central

Introduction Polyacrylamide hydrogel has been considered a safe and biocompatible soft tissue filler, and it has been widely used in cosmetic procedures. However, recent studies have revealed some complications with polyacrylamide filler injections. Case Report We present the case of foreign-body granulomas of the glabella, which subsequently formed an infectious ulcer 3 years after a polyacrylamide injection. An immunohistochemical evaluation of the foreign-body granulomas was performed in order to study the relationship between foreign-body granulomas and immune response. Conclusion We believe that our analysis of foreign-body granulomas 1 and 3 years after a filler injection may contribute to revealing the mechanism of chronic and intractable infections after filler injections. PMID:23874295

Park, Kio; Nishiwaki, Fuyuko; Kabashima, Kenji; Miyachi, Yoshiki

2013-01-01

457

Creating Wildlife Habitat with Native Florida Freshwater Wetland Plants1  

E-print Network

CIR 912 Creating Wildlife Habitat with Native Florida Freshwater Wetland Plants1 Martin B. Main by establishing and managing desirable native plants. Native wetland plants play important ecological roles many more species than non-native plants because native wildlife evolved with native plant communities

Watson, Craig A.

458

Gel Electrophoresis Lab: DNA Fingerprinting  

NSDL National Science Digital Library

This lab activity from the Biotechnology Alliance for Suncoast Biology Educators introduces the methods of RFLP analysis, or DNA fingerprinting, by using gel electrophoresis. Students will learn the role of restriction enzymes in DNA fingerprinting. Required materials, procedure and instructions are provided. This lesson plan may be downloaded in Microsoft Word document file format.

Ehlers, Megan

2012-10-24

459

Electromechanical coupling in polyelectrolyte gels  

Microsoft Academic Search

This work concerns the systematic characterization of the electromechanical coupling in polyelectrolyte gels (PGs) in correlation with their structure and physical properties in view of their potential application as pressure sensors. PGs are electroactive polymers that respond with an electrical potential difference to gradients in mechanical stress and vice versa. So far, these materials have mainly been studied as electrical

Katsiaryna I. Prudnikova

2010-01-01

460

Gluing gels: A nanoparticle solution  

NASA Astrophysics Data System (ADS)

Synthetic polymer gels with certain surface chemistries can be glued together by a simple and inexpensive method that uses commercially available silica nanoparticles. Biological tissues can also be joined by this nanotechnological route, eliminating the need for sutures, additional adhesives or chemical reactions.

Appel, Eric A.; Scherman, Oren A.

2014-03-01

461

Gel Electrophoresis Lab: Paternity Case  

NSDL National Science Digital Library

This lab activity from the Biotechnology Alliance for Suncoast Biology Educators provides instructions for conducting a gel electrophoresis lab. Students will try to solve a paternity case with this activity by obtaining a DNA fingerprint from each potential father, the mother and the child. This activity may be downloaded in PDF file format. A data collection sheet and student questions are also included.

2013-07-05

462

Capillary fracture of soft gels.  

PubMed

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[proportional]t(3/4). 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. PMID:24229192

Bostwick, Joshua B; Daniels, Karen E

2013-10-01

463

Removal of methylene blue dye from aqueous solution by adsorption onto sodium humate/polyacrylamide/clay hybrid hydrogels.  

PubMed

A type of novel hybrid hydrogels from sodium humate (SH), polyacrylamide (PAM), and hydrophilic laponite clay were prepared using potassium persulfate (KPS) as the initiator and N,N'-methylenebisacrylamide (MBA) as the cross-linker. The morphology of the hydrogels was characterized by field emission scanning electron microscope (FESEM). The adsorption-desorption kinetics of methylene blue (MB) were also investigated. It was shown that SH/PAM/clay hydrogels exhibited excellent performance in MB adsorption. The maximum absorption concentration of MB was 800 mg/l/g of hydrogel. The adsorption concentration of hydrogels increased with increasing SH or clay content. Less MB were desorbed with increasing SH content, while the clay content had no significant influence on the amount of MB desorbed. This effect was attributed to the formation of a ionic complex between the imine groups of MB and the ionized carboxylic groups of SH. MB diffusion process was dominant in MB desorption. PMID:17601732

Yi, Ju-Zhen; Zhang, Li-Ming

2008-05-01

464

Two simple and rapid methods for the detection of polymer-degrading enzymes on high-resolution, alkaline, cold, in situ-native (HiRACIN)PAGE and high-resolution, in situ-inhibited native (HiRISIN)PAGE  

Microsoft Academic Search

Two sensitive, high-resolution and exceedingly versatile methods for the detection of isoenzymes of polymer-degrading enzymes on high-resolution, alkaline, cold, in situ-native (HiRACIN)-PAGE and high-resolution in situ-inhibited, native (HiRISIN)-PAGE are described. Extracellular crude extracts containing xylanases and carboxymethylcellulases from Scopulariopsis sp. and glucoamylases from Aspergillus niger were subjected to non-denaturing PAGE containing substrates in the resolving gel. In case of HiRACIN-PAGE, the enzymes

Ahmed Jawaad Afzal; Salim Ahmed Bokhari; Waseem Ahmad; Mohammad Hamid Rashid; Mohammad Ibrahim Rajoka; Khawar Sohail Siddiqui

2000-01-01

465

TCP over native ATM (TONA)  

NASA Astrophysics Data System (ADS)

This paper presents an approach for carrying Internet transport PDUs directly over AAL5, discarding IP. The main advantage is an overhead reduction that can significantly impact upstream Internet traffic performance in asymmetric access network technologies such as HFC and ADSL. The TONA model proposed in the paper considers ATM to be at network layer-3, and tries to combine the best solutions given by previous models. Removal of the IP layer and the use of TCP over native ATM were achieved in a way that maximizes comparability with current standards and existent Internet applications, and allows the use of TCP by ATM applications.

Grilo, Antonio M.; Nunes, Mario S.

1998-09-01

466

Valuable Plants Native to Texas.  

E-print Network

part of the state. It will grow from seed or can be purchased from dealers. EPHEDRACEAE Ephedra antisyphi'litica Berl ex. C. A. Meyer. Joint Fir. This peculiar shrub is little known but makes a very interesting hedge or specimen plant. Its long... reed-like green branches and clusters of yellow stamens and red berries in early spring make the plant worthy of cultivation. It is a native of sections 4, 3, 5, 6, and 7. Ephedra peczuncz~fiata Engelm. Vine Ephedra. This is. the most pecu- liar...

Parks, Harris Braley

1937-01-01

467

Commercial applications of block copolymer photonic gels  

E-print Network

Block copolymer photonic gels are a simple and easily processed material which responds rapidly to environmental stimuli through a color change. The diblock copolymer that forms the gel self-assembles into a lamellar ...

Lou, Sally S

2008-01-01

468

Literacy Skill Differences between Adult Native English and Native Spanish Speakers  

PubMed Central

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 tasks but were equally skilled on the phonology and vocabulary tasks. Morphology, coupled with phonology, was a stronger predictor of vocabulary and comprehension abilities for the native Spanish speakers, which suggests that instruction focused on morphology is likely to have a greater impact on this group.

Herman, Julia; Cote, Nicole Gilbert; Reilly, Lenore; Binder, Katherine S.

2014-01-01