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1

21 CFR 172.665 - Gellan gum.  

Code of Federal Regulations, 2011 CFR

... 3 2011-04-01 2011-04-01 false Gellan gum. 172.665 Section 172.665 Food and Drugs ...PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.665 Gellan...

2011-04-01

2

21 CFR 172.665 - Gellan gum.  

Code of Federal Regulations, 2012 CFR

... 3 2012-04-01 2012-04-01 false Gellan gum. 172.665 Section 172.665 Food and Drugs ...PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.665 Gellan...

2012-04-01

3

21 CFR 172.665 - Gellan gum.  

Code of Federal Regulations, 2010 CFR

... 3 2010-04-01 2009-04-01 true Gellan gum. 172.665 Section 172.665 Food and Drugs ...PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.665 Gellan...

2010-04-01

4

21 CFR 172.665 - Gellan gum.  

... 3 2014-04-01 2014-04-01 false Gellan gum. 172.665 Section 172.665 Food and Drugs ...PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.665 Gellan...

2014-04-01

5

21 CFR 172.665 - Gellan gum.  

Code of Federal Regulations, 2013 CFR

... 3 2013-04-01 2013-04-01 false Gellan gum. 172.665 Section 172.665 Food and Drugs ...PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.665 Gellan...

2013-04-01

6

Enhanced gelation properties of purified gellan gum.  

PubMed

Gellan gum is a hydrogel-forming polysaccharide when combined with monovalent or divalent cations such as sodium, magnesium, potassium or calcium. Commercially, gellan gums are sold with trace amounts of these cations, which have been proven to affect the gelation and mechanical properties of the resultant hydrogels. A new method based on impedance analysis for determining the gel transition temperature of purified and un-purified gellan gum is presented. The sodium salt form of gellan gum is shown to have lower dissolution and gel transition temperatures. PMID:24637048

Kirchmajer, Damian Martin; Steinhoff, Benedikt; Warren, Holly; Clark, Ross; in het Panhuis, Marc

2014-03-31

7

Evaluation of carboxymethyl gellan gum as a mucoadhesive polymer.  

PubMed

The study was conducted to evaluate carboxymethyl gellan gum as bioadhesive polymer for drug delivery applications. Gellan gum was carboxymethylated by reacting it with monochloroacetic acid. Degree of carboxymethyl substitution was found to be 1.18. Further, carboxymethylation of gellan gum was found to increase its degree of crystallinity, surface roughness and diminish the cation-induced gelation. On comparative evaluation carboxymethyl gellan gum showed 2.71-fold higher mucoadhesive strength than gellan gum. Evaluation of ex vivo ocular tolerance using chorioallantoic membrane of hen's egg and cytotoxicity screening on Vero cells using resazurin assay revealed that caroboxymethyl gellan gum is non-irritant and biocompatible. Ionotiropically gelled beads of carboxymethyl gellan gum formulated using metformin as the model drug and calcium chloride as the cross-linking agent showed ex vivo bioadhesion of 100% over 24h. Further, it was observed that carboxymethyl gellan gum beads released metformin at a rate faster than gellan gum. PMID:23178342

Ahuja, Munish; Singh, Seema; Kumar, Ashok

2013-02-01

8

Gellan gum as a substitute for agar in leptospiral media.  

PubMed Central

An albumin polysorbate semisolid medium (Ellinghausen McCullough Johnson Harris medium) gelled with gellan gum (Gelrite; Kelco Div., Merck & Co., Inc.) compared favorably with conventional agar media for the cultivation of both pathogenic and saprophytic leptospires. The gellan gum medium supported the growth of all 18 leptospiral strains studied which included an array of serovars with various fastidious growth characteristics. Gellan gum medium was also used advantageously as a long-term maintenance medium; 9- to 12-month-old cultures still contained viable organisms. The colonial growth in gellan gum plating medium of six representative strains was consistent with previously described colonial growth on agar plating media. In addition, gellan gum medium appeared to be an excellent medium for the recovery of leptospires from the blood, liver, and kidneys of hamsters experimentally infected with a virulent Leptospira interrogans serovar bataviae strain. As few as 1 to 10 organisms in the infective tissue could be recovered in semisolid Ellinghausen McCullough Johnson Harris-gellan gum medium. The antigenicity did not appear to be affected by growth in gellan gum medium. The hamster-virulent strain of L. interrogans serovar bataviae isolated from a moribund hamster maintained its virulence after 10 sequential passages in gellan gum medium. Gellan gum medium can be a valuable adjunct to currently used cultural procedures. Images PMID:3754265

Rule, P L; Alexander, A D

1986-01-01

9

The latest technologies for the application of gellan gum  

Microsoft Academic Search

Gellan gum already has 10 years’ history of commercial application as a food additive, and now it has been applied to a very\\u000a wide range of foods. Gellan gum is a polysaccharide produced extracellularly by a microorganism (Pseudomonas elodea); it is a straight-chain heteropolysaccharide and comprises a repeating unit of four monosaccharide molecules, i.e., glucose,\\u000a glucuronic acid, glucose, and rhamnose,

T. Omoto; Y. Uno; I. Asai

10

Bioremediation of coking wastewater containing carbazole, dibenzofuran and dibenzothiphene by immobilized naphthalene-cultivated Arthrobacter sp. W1 in magnetic gellan gum.  

PubMed

In this study, the cometabolic degradation of carbazole (CA), dibenzofuran (DBF), and dibenzothiphene (DBT) by immobilized Arthrobacter sp. W1 cells pregrown with naphthalene was investigated. Four kinds of polymers were evaluated as immobilization supports for strain W1. After comparison with agar, alginate, and ?-carrageenan, gellan gum was selected as the optimal immobilization support. Furthermore, magnetic Fe?O? nanoparticle was selected as most suitable nanoparticle for immobilization and the optimal concentration was 80 mg/L. The relationship between specific degradation rate and the initial concentration of CA, DBF and DBT was described well by Michaelis-Menten kinetics. The recycling experiments demonstrated that the magnetically immobilized cells coupling with activation zeolite showed highly bioremediation activity on the coking wastewater containing high concentration of phenol, naphthalene, CA, DBF and DBT during seven recycles. Toxicity assessment indicated the treatment of the coking wastewater by magnetically immobilized cells with activation zeolite led to less toxicity than untreated wastewater. PMID:24905045

Shi, Shengnan; Qu, Yuanyuan; Ma, Fang; Zhou, Jiti

2014-08-01

11

Biodegradation behavior of gellan gum in simulated colonic media.  

PubMed

The objective of this investigation was to test the biodegradability of gellan gum in the presence of galactomannanase in order to explore its suitability for the development of colon-specific controlled delivery systems. Gellan beads containing azathioprine (AZA) were prepared by ionotropic gelation in the presence of Ca2+ ions and were coated with an enteric polymer, Eudragit S-100. The effects of the simulated colonic fluid (SCF, pH 7.4 phosphate buffer) containing 15 mg/mL of galactomannanase on the in vitro release profiles of uncoated and enteric-coated beads were investigated, and the morphological changes in the structure of uncoated beads were assessed by scanning electron microscopy (SEM). In addition, 1% solution of deacetylated gellan gum was prepared and several aliquots of the resulting solution were evaluated rheologically to determine the concentration- and time-dependent effects of galactomannanase. Based on the percent drug released at 2 h, approximately 10% greater amount of drug was released in the SCF containing galactomannanase when compared with the enzyme-free dissolution medium. Results of rheological studies demonstrated that effects of galactomannanase on the viscosity of gellan gum solution are concentration-dependent rather than time-dependent. A significant decrease in the viscosity was noted in the presence of galactomannanase at a concentration of 15 mg/ mL, indicating that the polysaccharide degraded in an enzymatic reaction. SEM micrographs showed a distinct disruption of the polymeric network in the SCF. Overall, the results suggest that gellan gum undergoes significant degradation in the presence of galactomannanase which in turn facilitates the drug release from beads in the SCF in a controlled manner, thus approving the suitability of gellan gum as a carrier for controlled colonic delivery. PMID:15581076

Singh, Brahma N; Trombetta, Louis D; Kim, Kwon H

2004-11-01

12

Controlled release of cephalexin through gellan gum beads: Effect of formulation parameters on entrapment efficiency, size, and drug release  

Microsoft Academic Search

Gellan gum beads containing cephalexin were prepared by extruding the dispersion of cephalexin and gellan gum into a solution containing a mixture of calcium and zinc ions (counterions). Beads were prepared by changing experimental variables such as pH of the counterion solution and amount of cephalexin loading in order to optimize process variables on the final % drug entrapment efficiency,

Sunil A. Agnihotri; Sheetal S. Jawalkar; Tejraj M. Aminabhavi

2006-01-01

13

Effects of salts on the gel-sol transition of gellan gum by differential scanning calorimetry and thermal scanning rheology  

Microsoft Academic Search

The rheological and thermal properties of sodium form gellan gum solutions with and without sodium chloride, potassium chloride, calcium chloride and magnesium chloride were studied by dynamic viscoelastic measurement and differential scanning calorimetry. Temperature dependence of the loss modulus for gellan gum solutions of lower concentrations without salt showed a one step-like change at a certain temperature, however that for

Emako Miyoshi; Tomohisa Takaya; Katsuyoshi Nishinari

1995-01-01

14

Multi-modality gellan gum-based tissue-mimicking phantom with targeted mechanical, electrical, and thermal properties  

NASA Astrophysics Data System (ADS)

This study develops a new class of gellan gum-based tissue-mimicking phantom material and a model to predict and control the elastic modulus, thermal conductivity, and electrical conductivity by adjusting the mass fractions of gellan gum, propylene glycol, and sodium chloride, respectively. One of the advantages of gellan gum is its gelling efficiency allowing highly regulable mechanical properties (elastic modulus, toughness, etc). An experiment was performed on 16 gellan gum-based tissue-mimicking phantoms and a regression model was fit to quantitatively predict three material properties (elastic modulus, thermal conductivity, and electrical conductivity) based on the phantom material's composition. Based on these material properties and the regression model developed, tissue-mimicking phantoms of porcine spinal cord and liver were formulated. These gellan gum tissue-mimicking phantoms have the mechanical, thermal, and electrical properties approximately equivalent to those of the spinal cord and the liver.

Chen, Roland K.; Shih, A. J.

2013-08-01

15

Synthesis and characterization of N-(2-aminoethyl)-2-acetamidyl gellan gum with potential biomedical applications.  

PubMed

N-(2-aminoethyl)-2-acetamidyl gellan gum (GCM-EDA) was prepared by carboxymethylation (via nucleophilic substitution of primary hydroxyl groups of the ?-D-glucose unit of gellan gum, in the presence of alkali and chloroacetic acid) and reaction with tert-butyl N-(2-aminoethyl) carbamate (N-Boc-EDA) using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) as an activator, followed by deprotection with trifluoroacetic acid. The structural confirmation and characterization of N-(2-aminoethyl)-2-acetamidyl gellan gum was performed by spectroscopic, rheological and thermogravimetric analysis, and in vitro tests showed a lack of cytotoxicity which is indicative of the potential of this material to be used in biomedical applications. PMID:23987332

Novac, O; Lisa, G; Barbu, E; Alhaique, F; Popa, M I

2013-10-15

16

Antibacterial quaternized gellan gum based particles for controlled release of ciprofloxacin with potential dermal applications.  

PubMed

This paper presents the synthesis and characterization of gellan gum derivatives containing quaternary ammonium groups, with the purpose of obtaining particulate controlled release systems for ciprofloxacin. Quaternized gellan derivatives were synthesized by grafting N-(3-chloro-2-hydroxypropyl)-trimethyl ammonium chloride onto gellan primary hydroxyl groups by nucleophilic substitution, in the presence of alkali, under specific reaction conditions using various gellan/N-(3-chloro-2-hydroxypropyl)-trimethyl ammonium chloride molar ratios. Degree of quaternization was determined by (1)H NMR spectroscopy and AgNO3 conductometric titration. Thermal behavior was investigated for all materials by thermogravimetric analysis. A study of the degree of quaternization and effect of the reaction conditions upon activation energy of quaternized gellan derivatives for the main degradation step by applying the Kissinger method at four heating rates is also reported. The novelty that this work brings refers to obtaining quaternized gellan and chitosan based particles with retention of quaternary ammonium moieties' antibacterial activity. In vitro transdermal release tests of ciprofloxacin from loaded particles were carried out on rat skin in isotonic phosphate buffer solution (pH=7.43). Ciprofloxacin was released up to 24 h, confirming quaternized gellan-chitosan particles' potential as controlled release systems for topical dermal applications. PMID:24411380

Novac, O; Lisa, G; Profire, L; Tuchilus, C; Popa, M I

2014-02-01

17

Simvastatin loaded composite polyspheres of gellan gum and carrageenan: in vitro and in vivo evaluation.  

PubMed

We investigated the lipid lowering ability of simvastatin loaded gellan gum-carrageenan composite polyspheres, which were prepared by ionotropic gelation/covalent crosslinking method. The surface morphology revealed that the polyspheres have rough and dense surface. The drug entrapment efficiency of the polyspheres prepared by ionic crosslinking was higher than those prepared by dual crosslinking. The in vitro drug release study indicated that the ionically crosslinked polyspheres discharged the drug quickly whereas, dual crosslinked polyspheres extended the drug release for longer period. The hypolipidemic activity performed on Wistar rats indicated that the polyspheres have effectively reduced the elevated total serum cholesterol and triglycerides. PMID:23511060

Kulkarni, Raghavendra V; Nagathan, Vineeta V; Biradar, Prakash R; Naikawadi, Akram A

2013-06-01

18

Cytotoxicity of sophorolipid-gellan gum-gold nanoparticle conjugates and their doxorubicin loaded derivatives towards human glioma and human glioma stem cell lines  

Microsoft Academic Search

Biocompatible gold nanoparticles were synthesized by using a naturally occurring gum-Gellan Gum-as a capping and reducing agent. These were further conjugated with sophorolipids which again were accessed through a biochemical transformation of a fatty acid. The cellular uptake of sophorolipid-conjugated gellan gum reduced gold nanoparticles and their cytotoxicity on human glioma cell line LN-229 and human glioma stem cell line

Sheetal Dhar; E. Maheswara Reddy; Asmita Prabhune; Varsha Pokharkar; Anjali Shiras; B. L. V. Prasad

2011-01-01

19

Aceclofenac-loaded unsaturated esterified alginate/gellan gum microspheres: in vitro and in vivo assessment.  

PubMed

Aceclofenac-loaded alginate/gellan gum microspheres for prolonged aceclofenac release were prepared through maleic anhydride-induced unsaturated esterification. The drug entrapment efficiency of these microspheres was found 39.30 ± 1.28% to 98.46 ± 0.40% and their average particle sizes were 270-490 ?m. These microspheres were characterized by FTIR, DSC, P-XRD and SEM analysis. The in vitro dissolution indicated prolonged sustained release of aceclofenac over 6h, which also followed the Korsmeyer-Peppas model (R(2)=0.9571-0.9952). The microspheres prepared through 3% (w/v) maleic anhydride-induced esterification exhibited comparatively slower drug-release. Most of the microspheres were followed Fickian diffusion mechanism except the microspheres containing higher gellan gum content, which followed anomalous (non-Fickian) diffusion. The in vivo results showed sustained systemic absorption of aceclofenac in rabbits and excellent anti-inflammatory activity in carrageenan-induced rats after oral administration over prolonged period. PMID:23499517

Jana, Sougata; Das, Arindam; Nayak, Amit Kumar; Sen, Kalyan Kumar; Basu, Sanat Kumar

2013-06-01

20

High Rate of N2 Fixation by East Siberian Cryophilic Soil Bacteria as Determined by Measuring Acetylene Reduction in Nitrogen-Poor Medium Solidified with Gellan Gum? †  

PubMed Central

For evaluating N2 fixation of diazotrophic bacteria, nitrogen-poor liquid media supplemented with at least 0.5% sugar and 0.2% agar are widely used for acetylene reduction assays. In such a soft gel medium, however, many N2-fixing soil bacteria generally show only trace acetylene reduction activity. Here, we report that use of a N2 fixation medium solidified with gellan gum instead of agar promoted growth of some gellan-preferring soil bacteria. In a soft gel medium solidified with 0.3% gellan gum under appropriate culture conditions, bacterial microbiota from boreal forest bed soils and some free-living N2-fixing soil bacteria isolated from the microbiota exhibited 10- to 200-fold-higher acetylene reduction than those cultured in 0.2% agar medium. To determine the N2 fixation-activating mechanism of gellan gum medium, qualitative differences in the colony-forming bacterial components from tested soil microbiota were investigated in plate cultures solidified with either agar or gellan gum for use with modified Winogradsky's medium. On 1.5% agar plates, apparently cryophilic bacterial microbiota showed strictly distinguishable microbiota according to the depth of soil in samples from an eastern Siberian Taiga forest bed. Some pure cultures of proteobacteria, such as Pseudomonas fluorescens and Burkholderia xenovorans, showed remarkable acetylene reduction. On plates solidified with 1.0% gellan gum, some soil bacteria, including Luteibacter sp., Janthinobacterium sp., Paenibacillus sp., and Arthrobacter sp., uniquely grew that had not grown in the presence of the same inoculants on agar plates. In contrast, Pseudomonas spp. and Burkholderia spp. were apparent only as minor colonies on the gellan gum plates. Moreover, only gellan gum plates allowed some bacteria, particularly those isolated from the shallow organic soil layer, to actively swarm. In consequence, gellan gum is a useful gel matrix to bring out growth potential capabilities of many soil diazotrophs and their consortia in communities of soil bacteria. PMID:19286791

Hara, Shintaro; Hashidoko, Yasuyuki; Desyatkin, Roman V.; Hatano, Ryusuke; Tahara, Satoshi

2009-01-01

21

High rate of N2 fixation by East Siberian cryophilic soil bacteria as determined by measuring acetylene reduction in nitrogen-poor medium solidified with gellan gum.  

PubMed

For evaluating N(2) fixation of diazotrophic bacteria, nitrogen-poor liquid media supplemented with at least 0.5% sugar and 0.2% agar are widely used for acetylene reduction assays. In such a soft gel medium, however, many N(2)-fixing soil bacteria generally show only trace acetylene reduction activity. Here, we report that use of a N(2) fixation medium solidified with gellan gum instead of agar promoted growth of some gellan-preferring soil bacteria. In a soft gel medium solidified with 0.3% gellan gum under appropriate culture conditions, bacterial microbiota from boreal forest bed soils and some free-living N(2)-fixing soil bacteria isolated from the microbiota exhibited 10- to 200-fold-higher acetylene reduction than those cultured in 0.2% agar medium. To determine the N(2) fixation-activating mechanism of gellan gum medium, qualitative differences in the colony-forming bacterial components from tested soil microbiota were investigated in plate cultures solidified with either agar or gellan gum for use with modified Winogradsky's medium. On 1.5% agar plates, apparently cryophilic bacterial microbiota showed strictly distinguishable microbiota according to the depth of soil in samples from an eastern Siberian Taiga forest bed. Some pure cultures of proteobacteria, such as Pseudomonas fluorescens and Burkholderia xenovorans, showed remarkable acetylene reduction. On plates solidified with 1.0% gellan gum, some soil bacteria, including Luteibacter sp., Janthinobacterium sp., Paenibacillus sp., and Arthrobacter sp., uniquely grew that had not grown in the presence of the same inoculants on agar plates. In contrast, Pseudomonas spp. and Burkholderia spp. were apparent only as minor colonies on the gellan gum plates. Moreover, only gellan gum plates allowed some bacteria, particularly those isolated from the shallow organic soil layer, to actively swarm. In consequence, gellan gum is a useful gel matrix to bring out growth potential capabilities of many soil diazotrophs and their consortia in communities of soil bacteria. PMID:19286791

Hara, Shintaro; Hashidoko, Yasuyuki; Desyatkin, Roman V; Hatano, Ryusuke; Tahara, Satoshi

2009-05-01

22

Cytotoxicity of sophorolipid-gellan gum-gold nanoparticle conjugates and their doxorubicin loaded derivatives towards human glioma and human glioma stem cell lines.  

PubMed

Biocompatible gold nanoparticles were synthesized by using a naturally occurring gum--Gellan Gum--as a capping and reducing agent. These were further conjugated with sophorolipids which again were accessed through a biochemical transformation of a fatty acid. The cellular uptake of sophorolipid-conjugated gellan gum reduced gold nanoparticles and their cytotoxicity on human glioma cell line LN-229 and human glioma stem cell line HNGC-2 were investigated. Quite surprisingly even the simple sophorolipid-conjugated gellan gum reduced/capped gold nanoparticles showed greater efficacy in killing the glioma cell lines and, gratifyingly, the glioma stem cell lines also. The cytotoxic effects became more prominent once the anti cancer drug doxorubicin hydrochloride was also conjugated to these gold nanoparticles. PMID:21069248

Dhar, Sheetal; Reddy, E Maheswara; Prabhune, Asmita; Pokharkar, Varsha; Shiras, Anjali; Prasad, B L V

2011-02-01

23

Mucoadhesive beads of gellan gum/pectin intended to controlled delivery of drugs.  

PubMed

Gellan gum/pectin beads were prepared by ionotropic gelation, using Al(3+) as crosslinker. High yield (92.76%) and entrapment efficiency (52.22-88.78%) were reached. Beads exhibited high circularity (0.730-0.849) and size between 728.95 and 924.56?m. Particle size and circularity was increased by raising polymer and crosslinker concentrations. Polymers ratio did not influence beads properties. The materials stability and the absence of drug-polymers interactions were evidenced by thermal analysis and FTIR. The high beads mucoadhesiveness was evidenced by in vitro and ex vivo tests. The erosion of beads was greater in acid media while swelling was more pronounced in pH 7.4. Drug release was dependent on pH in which samples 11H1-3, 11H1-5 and 41H1-3 released only 34%, 20% and 22% of ketoprofen in pH 1.2, while in pH 7.4 the drug release was sustained up to 360min. Korsmeyer-Peppas model demonstrated that drug release occurred according to super case-II transport. PMID:25256487

Prezotti, Fabíola Garavello; Cury, Beatriz Stringhetti Ferreira; Evangelista, Raul Cesar

2014-11-26

24

Engineering cell-adhesive gellan gum spongy-like hydrogels for regenerative medicine purposes.  

PubMed

The similarity between the extracellular matrix of soft tissue and hydrogels, characterized by high-water-content viscoelastic polymeric networks, has been sustaining the advancement of hydrogels for tissue engineering and regenerative medicine (TERM) purposes. Current research on hydrogels has focused on introducing cell-adhesive peptides to promote cell adhesion and spreading, a critical applicability limitation. Here we report the development of gellan gum (GG) spongy-like hydrogels with ameliorated mechanical performance and flexibility in relation to hydrogels, using a simple and cost-effective method. Most importantly, these materials allow the entrapment of different cell types representing mesenchymal, epidermal and osteoblastic phenotypes that spread within the three-dimensional microstructure. This effect was associated with microstructural rearrangements characterized by pore wall thickening and pore size augmentation, and lower water content than precursor hydrogels. These properties significantly affected protein adsorption once cell adhesion was inhibited in the absence of serum. Spongy-like hydrogels are not adhesive for endothelial cells; however, this issue was surpassed by a pre-incubation with a cell-adhesive protein, as demonstrated for other substrates but not for traditional hydrogels. The proposed cell-compatible GG-based structures avoid time-consuming and expensive strategies that have been used to include cell-adhesive features in traditional hydrogels. This, associated with their off-the-shelf availability in an intermediary dried state, represents unique and highly relevant features for diverse TERM applications. PMID:25048775

da Silva, Lucília P; Cerqueira, Mariana T; Sousa, Rui A; Reis, Rui L; Correlo, Vitor M; Marques, Alexandra P

2014-11-01

25

Chondrogenic potential of two hASCs subpopulations loaded onto gellan gum hydrogel evaluated in a nude mice model.  

PubMed

Cells constitute one of the fundamental components of any cartilage tissue engineering approach. Adipose tissue derived stem cells (ASCs) have a promising future considering the abundance of this tissue in the human body, ease of harness, and the high number of stem cells that can be isolated from small amounts of tissue. However the stromal vascular fraction of the adipose tissue that is isolated upon digestion by collagenase followed by a rough selection of the adherent cells, is composed of many different types of cells, some of which may compromise the proliferation and the differentiation of the ASCs. This manuscript reports a study on the in vivo chondrogenic potential of two ASCs specific subpopulations isolated using a method based on immunomagnetic beads coated with specific antibodies. These ASCs subpopulations, isolated using immunomagnetic beads coated with CD29 and CD105 antibodies, were subsequently transfected with green fluorescent protein (GFP), expanded, and pre-differentiated into the chondrogenic lineage, before being encapsulated in a novel hydrogel based on gellan gum, that has recently been showed to promote in vitro and in vivo cartilage tissue formation. The two ASCs subpopulations encapsulated in the gellan gum hydrogel and in vitro pre-differentiated, were then subcutaneously implanted in nude mice for 6 weeks. Explants were analyzed by various techniques, namely histology, immunohistology and real time RT-PCR that demonstrated the different behaviour of the two ASCs subpopulations under study, namely their potential to differentiate into the chondrogenic lineage and to form new cartilage tissue. PMID:23755728

Rada, Tommaso; Carvalho, Pedro P; Santos, Tircia C; Castro, Antonio G; Reis, Rui L; Gomes, Manuela E

2013-09-01

26

Gellan gum biosynthesis in Sphingomonas paucimobilis ATCC 31461: Genes, enzymes and exopolysaccharide production engineering  

Microsoft Academic Search

  The commercial gelling agent, gellan, is an extracellular polysaccharide (EPS) produced by Sphingomonas paucimobilis ATCC 31461. In recent years, significant progress in understanding the relationship between gellan structure and properties\\u000a and elucidation of the biosynthesis and engineering of this recent product of biotechnology has been made. This review focuses\\u000a on recent advances in this field. Emphasis is given to identification

I Sá-Correia; A M Fialho; P Videira; L M Moreira; A R Marques; H Albano

2002-01-01

27

Evaluation of the ability of xanthan gum/gellan gum/hyaluronan hydrogel membranes to prevent the adhesion of postrepaired tendons.  

PubMed

After tendon-repair surgery, adhesion between the surgical tendon and the synovial sheath is often presented resulting in poor functional repair of the tendon. This may be prevented using a commercially available mechanical barrier implant, Seprafilm, which is composed of hyaluronan (HA) and carboxymethyl cellulose hydrogels. In a rat model, prepared membranes of various compositions of gellan gum (GG), xanthan gum (XG) and HA as well as Seprafilm were wrapped around repaired tendons and the adhesion of the tendons was examined grossly and histologically after 3 weeks of healing. Certain formulations of the XG/GG/HA hydrogel membranes reduced tendon adhesion with equal efficacy but without reducing the tendon strength compared to Seprafilm. The designed membranes swelled rapidly and blanketed onto the tendon tissue more readily and closely than Seprafilm. Also they degraded slowly, which allowed the membranes to function as barriers for extended periods. PMID:25263886

Kuo, Shyh Ming; Chang, Shwu Jen; Wang, Hung-Yi; Tang, Shu Ching; Yang, Shan-Wei

2014-12-19

28

Thixotropic Behavior of Salad Dressings Stabilized with Modified Starch, Pectin, and Gellan Gum. Influence of Temperature  

Microsoft Academic Search

The thixotropy of low?oil salad dressing has been analyzed at different temperatures (8–26°C). The usual formulation containing modified starch (4%) was compared with others in which part of the starch had been substituted by pectin (0.5%) or different concentrations of gellan (0.1 and 0.5%). Up and down flow curves were measured, showing in all cases shear thinning behavior and fitting

M. J. Hernández; J. Dolz; Jesús Delegido; C. Cabeza; M. Dolz

2008-01-01

29

Tranexamic acid loaded gellan gum-based polymeric microbeads for controlled release: in vitro and in vivo assessment.  

PubMed

Gellan gum (GG) microbeads containing tranexamic acid (TA), an anti-fibrinolytic drug were prepared by a classic sol-gel transition induced by ionic crosslinking technique using aluminum chloride (AlCl3) as cross-linking agent. The influence of different formulation variables on in vitro physico-chemical parameters and drug release studies were performed systematically. The microbeads were evaluated by scanning electron microscopy (SEM), Fourier transform infra-red (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC) and high performance liquid chromatographic (HPLC) analysis. Particle size and swelling behavior of microbeads were also investigated. Microbeads showed improved drug encapsulation efficiency along with enhanced drug release. The in vivo studies exhibited sustained drug release in rabbits over a prolonged period after oral administration of these newly developed TA loaded GG microbeads. Based on the results of in vitro and in vivo studies in experimental animal model it was concluded that these microbeads provided intestinal specific controlled release of TA. PMID:24183265

Bhattacharya, Shiv Sankar; Banerjee, Subham; Chowdhury, Purojit; Ghosh, Amitava; Hegde, Rahul Rama; Mondal, Ranjit

2013-12-01

30

Enzymatic mineralization of gellan gum hydrogel for bone tissue-engineering applications and its enhancement by polydopamine.  

PubMed

Interest is growing in the use of hydrogels as bone tissue-engineering (TE) scaffolds due to advantages such as injectability and ease of incorporation of active substances such as enzymes. Hydrogels consisting of gellan gum (GG), an inexpensive calcium-crosslinkable polysaccharide, have been applied in cartilage TE. To improve GG suitability as a material for bone TE, alkaline phosphatase (ALP), an enzyme involved in mineralization of bone by cleaving phosphate from organic phosphate, was incorporated into GG hydrogels to induce mineralization with calcium phosphate (CaP). Incorporated ALP induced formation of apatite-like material on the submicron scale within GG gels, as shown by FTIR, SEM, EDS, XRD, ICP-OES, TGA and von Kossa staining. Increasing ALP concentration increased amounts of CaP as well as stiffness. Mineralized GG was able to withstand sterilization by autoclaving, although stiffness decreased. In addition, mineralizability and stiffness of GG was enhanced by the incorporation of polydopamine (PDA). Furthermore, mineralization of GG led to enhanced attachment and vitality of cells in vitro while cytocompatibility of the mineralized gels was comparable to one of the most commonly used bone substitute materials. The results proved that ALP-mediated enzymatic mineralization of GG could be enhanced by functionalization with PDA. Copyright © 2012 John Wiley & Sons, Ltd. PMID:23038649

Douglas, Tel; Wlodarczyk, M; Pamula, E; Declercq, Ha; de Mulder, Elw; Bucko, Mm; Balcaen, L; Vanhaecke, F; Cornelissen, R; Dubruel, P; Jansen, Ja; Leeuwenburgh, Scg

2014-11-01

31

Gellan Gum-Hyaluronic Acid Spongy-like Hydrogels and Cells from Adipose Tissue Synergize Promoting Neoskin Vascularization.  

PubMed

Currently available substitutes for skin wound healing often result in the formation of nonfunctional neotissue. Thus, urgent care is still needed to promote an effective and complete regeneration. To meet this need, we proposed the assembling of a construct that takes advantage of cell-adhesive gellan gum-hyaluronic acid (GG-HA) spongy-like hydrogels and a powerful cell-machinery obtained from adipose tissue, human adipose stem cells (hASCs), and microvascular endothelial cells (hAMECs). In addition to a cell-adhesive character, GG-HA spongy-like hydrogels overpass limitations of traditional hydrogels, such as reduced physical stability and limited manipulation, due to improved microstructural arrangement characterized by pore wall thickening and increased mean pore size. The proposed constructs combining cellular mediators of the healing process within the spongy-like hydrogels that intend to recapitulate skin matrix aim to promote neoskin vascularization. Stable and off-the-shelf dried GG-HA polymeric networks, rapidly rehydrated at the time of cell seeding then depicting features of both sponges and hydrogels, enabled the natural cell entrapment/encapsulation and attachment supported by cell-polymer interactions. Upon transplantation into mice full-thickness excisional wounds, GG-HA spongy-like hydrogels absorbed the early inflammatory cell infiltrate and led to the formation of a dense granulation tissue. Consequently, spongy-like hydrogel degradation was observed, and progressive wound closure, re-epithelialization, and matrix remodelling was improved in relation to the control condition. More importantly, GG-HA spongy-like hydrogels promoted a superior neovascularization, which was enhanced in the presence of human hAMECs, also found in the formed neovessels. These observations highlight the successful integration of a valuable matrix and prevascularization cues to target angiogenesis/neovascularization in skin full-thickness excisional wounds. PMID:25361388

Cerqueira, Mariana Teixeira; da Silva, Lucília Pereira; Santos, Tírcia Carlos; Pirraco, Rogério Pedro; Correlo, Vítor Manuel; Reis, Rui Luís; Marques, Alexandra Pinto

2014-11-26

32

Development of Re-Usable Yeast-Gellan Gum Micro-Bioreactors for Potential Application in Continuous Fermentation to Produce Bio-Ethanol  

PubMed Central

The objectives of this study were to investigate the feasibility of encapsulating yeast cells using gellan gum by an emulsification method and to evaluate the fermentation efficiency and the reusability of the micro-bioreactors produced. It was found that yeast cells could be successfully encapsulated to form relatively spherical micro-bioreactors with high specific surface area for mass transfer. Cell viability was found to be reduced by one log reduction after the emulsification process. The ethanol yield of the micro-bioreactors was comparable to that of free yeast in the first fermentation cycle. The micro-bioreactors remained intact and could be re-used up to 10 cycles of fermentation. Despite cell breakthrough, relatively high ethanol yields were obtained, indicating that the micro-bioreactors also functioned as regenerative reservoirs of yeast. PMID:24309306

Tan, Sook Mun; Heng, Paul Wan Sia; Chan, Lai Wah

2011-01-01

33

Development of re-usable yeast-gellan gum micro-bioreactors for potential application in continuous fermentation to produce bio-ethanol.  

PubMed

The objectives of this study were to investigate the feasibility of encapsulating yeast cells using gellan gum by an emulsification method and to evaluate the fermentation efficiency and the reusability of the micro-bioreactors produced. It was found that yeast cells could be successfully encapsulated to form relatively spherical micro-bioreactors with high specific surface area for mass transfer. Cell viability was found to be reduced by one log reduction after the emulsification process. The ethanol yield of the micro-bioreactors was comparable to that of free yeast in the first fermentation cycle. The micro-bioreactors remained intact and could be re-used up to 10 cycles of fermentation. Despite cell breakthrough, relatively high ethanol yields were obtained, indicating that the micro-bioreactors also functioned as regenerative reservoirs of yeast. PMID:24309306

Tan, Sook Mun; Heng, Paul Wan Sia; Chan, Lai Wah

2011-01-01

34

Formulation and In Vitro evaluation of pH sensitive oil entrapped polymeric blended gellan gum buoyant beads of clarithromycin  

PubMed Central

Background and the purpose of the study A gastroretentive pH sensitive system has been a frontier approach to release the drug in controlled manner in stomach and duodenum. The aim of this study was to develop buoyant beads of gellan based, wherein, the oil was entrapped, blended with hydroxypropyl methyl cellulose or carbopol 934 in order to evaluate its potential for targeted sustained delivery of clarithromycin in the gastric region. Methods Buoyant beads of gellan was developed by inotropic gelation technique using calcium carbonate as gas forming agent and the drug polymer dispersion was emulsified with mineral oil. The oil was entrapped and blended with hydroxypropyl methyl cellulose or carbopol 934. The developed beads were evaluated in terms of diameter,% floating, encapsulation efficiency, In vitro drug release, In vivo gastric residence efficacy and clarithromycine concentration in the mucosa of the experimental animal model. Results The scanning electron microscope photograph indicated that the prepared beads were spherical in shape and buoyancy, encapsulation efficiency and drug content obtained from all batches were satisfactory. Particle size and percentage buoyancy of the gel beads increased by raising the concentration of calcium carbonate. The formulation exhibited sustained release profile and was best fitted in the Peppas model with n<0.45. Subsequent coating of microbeads exhibited zero-order sustained pattern of the drug release up to 8 hrs. Batch B4 showed comparatively better residence and the drug concentration in the gastric mucosa of the treated animals. Conclusion The result provides evidence that the prepared optimized formulation may be used effectively for pH sensitive gastric targeted antibiotic such as clarithromycin. PMID:22615623

Tripathi, G.; Singh, S.

2010-01-01

35

Human skin cell fractions fail to self-organize within a gellan gum/hyaluronic acid matrix but positively influence early wound healing.  

PubMed

Split-thickness autografts still are the current gold standard to treat skin, upon severe injuries. Nonetheless, autografts are dependent on donor site availability and often associated to poor quality neoskin. The generation of dermal-epidermal substitutes by tissue engineering is seen as a promising strategy to overcome this problematic. However, solutions that can be safely and conveniently transplanted in one single surgical intervention are still very challenging as their production normally requires long culture time, and graft survival is many times compromised by delayed vascularization upon transplantation. This work intended to propose a strategy that circumvents the prolonged and laborious preparation period of skin substitutes and allows skin cells self-organization toward improved healing. Human dermal/epidermal cell fractions were entrapped directly from isolation within a gellan gum/hyaluronic acid (GG-HA) spongy-like hydrogel formed from an off-the-shelf dried polymeric network. Upon transplantation into full-thickness mice wounds, the proposed constructs accelerated the wound closure rate and re-epithelialization, as well as tissue neovascularization. A synergistic effect of the GG-HA matrix and the transplanted cells over those processes was demonstrated at early time points. Despite the human-derived and chimeric blood vessels found, the proposed matrix did not succeed in prolonging cells residence time and in sustaining the self-organization of transplanted human cells possibly due to primitive degradation. Despite this, the herein proposed approach open the opportunity to tackle wound healing at early stages contributing to re-epithelialization and neovascularization. PMID:24299468

Cerqueira, Mariana T; da Silva, Lucília P; Santos, Tírcia C; Pirraco, Rogério P; Correlo, Vitor M; Marques, Alexandra P; Reis, Rui L

2014-05-01

36

Gellan gum-based mucoadhesive microspheres of almotriptan for nasal administration: Formulation optimization using factorial design, characterization, and in vitro evaluation  

PubMed Central

Background: Almotriptan malate (ALM), indicated for the treatment of migraine in adults is not a drug candidate feasible to be administered through the oral route during the attack due to its associated symptoms such as nausea and vomiting. This obviates an alternative dosage form and nasal drug delivery is a good substitute to oral and parenteral administration. Materials and Methods: Gellan gum (GG) microspheres of ALM, for intranasal administration were prepared by water-in-oil emulsification cross-linking technique employing a 23 factorial design. Drug to polymer ratio, calcium chloride concentration and cross-linking time were selected as independent variables, while particle size and in vitro mucoadhesion of the microspheres were investigated as dependent variables. Regression analysis was performed to identify the best formulation conditions. The microspheres were evaluated for characteristics such as practical percentage yield, particle size, percentage incorporation efficiency, swellability, zeta potential, in vitro mucoadhesion, thermal analysis, X-ray diffraction study, and in vitro drug diffusion studies. Results: The shape and surface characteristics of the microspheres were determined by scanning electron microscopy, which revealed spherical nature and nearly smooth surface with drug incorporation efficiency in the range of 71.65 ± 1.09% – 91.65 ± 1.13%. In vitro mucoadhesion was observed the range of 79.45 ± 1.69% – 95.48 ± 1.27%. Differential scanning calorimetry and X-ray diffraction results indicated a molecular level dispersion of drug in the microspheres. In vitro drug diffusion was Higuchi matrix controlled and the release mechanism was found to be non-Fickian. Stability studies indicated that there were no significant deviations in the drug content, in vitro mucoadhesion and in vitro drug diffusion characteristics. Conclusion: The investigation revealed promising potential of GG microspheres for delivering ALM intranasally for the treatment of migraine. PMID:25400410

Abbas, Zaheer; Marihal, Sachin

2014-01-01

37

The mechanical properties and cytotoxicity of cell-laden double-network hydrogels based on photocrosslinkable gelatin and gellan gum biomacromolecules.  

PubMed

A major goal in the application of hydrogels for tissue engineering scaffolds, especially for load-bearing tissues such as cartilage, is to develop hydrogels with high mechanical strength. In this study, a double-network (DN) strategy was used to engineer strong hydrogels that can encapsulate cells. We improved upon previously studied double-network (DN) hydrogels by using a processing condition compatible with cell survival. The DN hydrogels were created by a two-step photocrosslinking using gellan gum methacrylate (GGMA) for the rigid and brittle first network, and gelatin methacrylamide (GelMA) for the soft and ductile second network. We controlled the degree of methacrylation of each polymer so that they obtain relevant mechanical properties as each network. The DN was formed by photocrosslinking the GGMA, diffusing GelMA into the first network, and photocrosslinking the GelMA to form the second network. The formation of the DN was examined by diffusion tests of the large GelMA molecules into the GGMA network, the resulting enhancement in the mechanical properties, and the difference in mechanical properties between GGMA/GelMA single networks (SN) and DNs. The resulting DN hydrogels exhibited the compressive failure stress of up to 6.9 MPa, which approaches the strength of cartilage. It was found that there is an optimal range of the crosslink density of the second network for high strength of DN hydrogels. DN hydrogels with a higher mass ratio of GelMA to GGMA exhibited higher strength, which shows promise in developing even stronger DN hydrogels in the future. Three dimensional (3D) encapsulation of NIH-3T3 fibroblasts and the following viability test showed the cell-compatibility of the DN formation process. Given the high strength and the ability to encapsulate cells, the DN hydrogels made from photocrosslinkable macromolecules could be useful for the regeneration of load-bearing tissues. PMID:22265786

Shin, Hyeongho; Olsen, Bradley D; Khademhosseini, Ali

2012-04-01

38

Survival of bifidobacteria in yogurt and simulated gastric juice following immobilization in gellan–xanthan beads  

Microsoft Academic Search

A novel acid-stable bead made of gellan gum and xanthan gum was used to immobilize Bifidobacteria. The beads (0.75% gellan and 1% xanthan gum) had an average diameter of 3 mm and did not shrink in 25% lactic acid solution, pH 1.5, or 20% acetic acid solution, pH 1.5, after storage at 4°C for 4 weeks. Bifidobacterium infantis ATCC 15697,

Wenrong Sun; Mansel W Griffiths

2000-01-01

39

Gellan-thioglycolic acid conjugate: synthesis, characterization and evaluation as mucoadhesive polymer.  

PubMed

Gellan-thioglycollic acid conjugate was synthesized with the objective to improve its mucoadhesive properties. Synthesis of conjugate was confirmed by -SH stretch in the Fourier-transform infrared spectra at 2571 cm(-1). It was found to contain 13.92 mM of thiol groups/g of the conjugate. Thiolation of gellan gum was found to slightly increase its degree of crystallinity and decrease its sensitivity to Ca(2+)-induced gelation. On screening of gellan-thioglycollic acid conjugate for ex-vivo ocular tolerance using hen's egg chorio-allantoic membrane test and for biocompatibility by resazurin assay on Vero-cells, it was found to be non-irritant and biocompatible. Metronidazole gels formulated using gellan thioglycollic acid conjugate as bioadhesive agent showed 1.82-fold higher mucoadhesive strength than the gels formulated using gellan gum. Further, the metronidazole gels containing gellan and gellan-thioglycollic conjugate released the drug following first-order and Higuchi's square-root release kinetics. In conclusion, gellan-thioglycollic acid conjugate is a promising bioadhesive excipient. PMID:24274549

Yadav, Shikha; Ahuja, Munish; Kumar, Ashok; Kaur, Harmanmeet

2014-01-01

40

Gellan sulfate inhibits Plasmodium falciparum growth and invasion of red blood cells in vitro  

PubMed Central

Here, we assessed the sulfated derivative of the microbial polysaccharide gellan gum and derivatives of ? and ?-carrageenans for their ability to inhibit Plasmodium falciparum 3D7 and Dd2 growth and invasion of red blood cells in vitro. Growth inhibition was assessed by means of flow cytometry after a 96-h exposure to the inhibitors and invasion inhibition was assessed by counting ring parasites after a 20-h exposure to them. Gellan sulfate strongly inhibited invasion and modestly inhibited growth for both P. falciparum 3D7 and Dd2; both inhibitory effects exceeded those achieved with native gellan gum. The hydrolyzed ?-carrageenan and oversulfated ?-carrageenan were less inhibitory than their native forms. In vitro cytotoxicity and anticoagulation assays performed to determine the suitability of the modified polysaccharides for in vivo studies showed that our synthesized gellan sulfate had low cytotoxicity and anticoagulant activity. PMID:24740150

Recuenco, Frances Cagayat; Kobayashi, Kyousuke; Ishiwa, Akiko; Enomoto-Rogers, Yukiko; Fundador, Noreen Grace V.; Sugi, Tatsuki; Takemae, Hitoshi; Iwanaga, Tatsuya; Murakoshi, Fumi; Gong, Haiyan; Inomata, Atsuko; Horimoto, Taisuke; Iwata, Tadahisa; Kato, Kentaro

2014-01-01

41

Nicotine Gum  

MedlinePLUS

Nicotine chewing gum is used to help people stop smoking cigarettes. Nicotine chewing gum should be used together with a smoking cessation ... Nicotine gum is used by mouth as a chewing gum and should not be swallowed. Follow the directions ...

42

Magnetorheology of xanthan-gum-coated soft magnetic carbonyl iron microspheres and their polishing characteristics  

NASA Astrophysics Data System (ADS)

Magnetorheological (MR) fluids are colloidal suspensions of soft magnetic particles dispersed in a non-magnetic liquid. Among their applications, MR polishing has attracted considerable attention owing to its smart control of the polishing characteristics for dedicated microelectromechanical system applications. To improve the polishing characteristics of MR fluids, we fabricated carbonyl iron (CI) microspheres coated with xanthan gum (XG) by using a solvent casting method. The morphologies and densities of both pure CI and CI/XG particles were characterized using a scanning electron microscope and a pycnometer, respectively. In addition, the rheological characteristics of the MR fluids under various applied magnetic field strengths were examined using a rotational rheometer. The MR polishing characteristics were conducted using an MR polishing machine to examine the surface roughness and the material removal by MR polishing with added nano-ceria slurry abrasives.

Kwon, Seung Hyuk; Choi, Hyoung Jin; Lee, Jung Won; Hong, Kwang Pyo; Cho, Myeong Woo

2013-06-01

43

Magnetic Parkia pendula seed gum as matrix for Concanavalin A lectin immobilization and its application in affinity purification.  

PubMed

The present work aimed to magnetize Parkia pendula seeds gum and use it as a matrix for Concanavalin A covalent immobilization. This composite was applied in affinity purification of glycoconjugates. Parkia pendula seeds were hydrated and the gum provenient from the supernatant was precipitated and washed with ethanol and dried. The gum was magnetized in co-precipitation using solutions of Fe+2 and Fe+3. Matrix activation was accomplished with NaIO4. Magnetized Parkia pendula seeds gum with covalently immobilized Concanavalin A was used as an affinity matrix for the recognition of bovine serum fetuin glycoprotein. Fetuin elution was carried out with a solution of glucose (300mM) and evaluated through SDS-PAGE. The efficiency of lectin immobilization and fetuin purification were 63% and 14%, respectively. These results indicate that the composite produced is a promising magnetic polysaccharide matrix for lectins immobilization. Thus, such system can be applied for affinity purification allowing an easy recovery by magnetic field. PMID:25140501

Rêgo, Moacyr J B M; Almeida, Sinara M; Bezerra, Sérgio A; Carvalho Júnior, Luiz B; Beltrão, Eduardo I C

2014-09-01

44

Spontaneous synthesis of gold nanoparticles on gum arabic-modified iron oxide nanoparticles as a magnetically recoverable nanocatalyst  

NASA Astrophysics Data System (ADS)

A novel magnetically recoverable Au nanocatalyst was fabricated by spontaneous green synthesis of Au nanoparticles on the surface of gum arabic-modified Fe3O4 nanoparticles. A layer of Au nanoparticles with thickness of about 2 nm was deposited on the surface of gum arabic-modified Fe3O4 nanoparticles, because gum arabic acted as a reducing agent and a stabilizing agent simultaneously. The resultant magnetically recoverable Au nanocatalyst exhibited good catalytic activity for the reduction of 4-nitrophenol with sodium borohydride. The rate constants evaluated in terms of pseudo-first-order kinetic model increased with increase in the amount of Au nanocatalyst or decrease in the initial concentration of 4-nitrophenol. The kinetic data suggested that this catalytic reaction was diffusion-controlled, owing to the presence of gum arabic layer. In addition, this nanocatalyst exhibited good stability. Its activity had no significant decrease after five recycles. This work is useful for the development and application of magnetically recoverable Au nanocatalyst on the basis of green chemistry principles.

Wu, Chien-Chen; Chen, Dong-Hwang

2012-06-01

45

Spontaneous synthesis of gold nanoparticles on gum arabic-modified iron oxide nanoparticles as a magnetically recoverable nanocatalyst  

PubMed Central

A novel magnetically recoverable Au nanocatalyst was fabricated by spontaneous green synthesis of Au nanoparticles on the surface of gum arabic-modified Fe3O4 nanoparticles. A layer of Au nanoparticles with thickness of about 2?nm was deposited on the surface of gum arabic-modified Fe3O4 nanoparticles, because gum arabic acted as a reducing agent and a stabilizing agent simultaneously. The resultant magnetically recoverable Au nanocatalyst exhibited good catalytic activity for the reduction of 4-nitrophenol with sodium borohydride. The rate constants evaluated in terms of pseudo-first-order kinetic model increased with increase in the amount of Au nanocatalyst or decrease in the initial concentration of 4-nitrophenol. The kinetic data suggested that this catalytic reaction was diffusion-controlled, owing to the presence of gum arabic layer. In addition, this nanocatalyst exhibited good stability. Its activity had no significant decrease after five recycles. This work is useful for the development and application of magnetically recoverable Au nanocatalyst on the basis of green chemistry principles. PMID:22713480

2012-01-01

46

Spontaneous synthesis of gold nanoparticles on gum arabic-modified iron oxide nanoparticles as a magnetically recoverable nanocatalyst.  

PubMed

A novel magnetically recoverable Au nanocatalyst was fabricated by spontaneous green synthesis of Au nanoparticles on the surface of gum arabic-modified Fe3O4 nanoparticles. A layer of Au nanoparticles with thickness of about 2?nm was deposited on the surface of gum arabic-modified Fe3O4 nanoparticles, because gum arabic acted as a reducing agent and a stabilizing agent simultaneously. The resultant magnetically recoverable Au nanocatalyst exhibited good catalytic activity for the reduction of 4-nitrophenol with sodium borohydride. The rate constants evaluated in terms of pseudo-first-order kinetic model increased with increase in the amount of Au nanocatalyst or decrease in the initial concentration of 4-nitrophenol. The kinetic data suggested that this catalytic reaction was diffusion-controlled, owing to the presence of gum arabic layer. In addition, this nanocatalyst exhibited good stability. Its activity had no significant decrease after five recycles. This work is useful for the development and application of magnetically recoverable Au nanocatalyst on the basis of green chemistry principles. PMID:22713480

Wu, Chien-Chen; Chen, Dong-Hwang

2012-01-01

47

Chain Release Behavior of Gellan Gels  

NASA Astrophysics Data System (ADS)

The chain release behavior from gellan gels was studied by immersing the gel into water and monitoring the mass loss as a function of time. Concentration of released gellan in the external solution was determined for gels of different sizes using phenol-sulfuric acid method. The chain release process became faster with increasing total surface area and volume. However the concentration of released chain normalized by surface area and volume suggests that the chain release itself is governed not only by the ionic effect and the amount of unassociated chains in gel but other factors such as osmotic pressure may play an important role on the chain release from the gels. The diffusion coefficient was estimated from the chain release process which is in the same order of magnitude reported for an isolated gellan chain by light scattering. Rheological measurements also suggest that the unassociated gellan chains are released out when immersed in pure water while unassociated chains are restricted to release out when immersed in salt solution due to the intrusion of cations which is responsible for further association of the unassociated gellan chains being in agreement with the previously published results. The elastic modulus of gels was increased by immersion of gels in water and in salt solutions, which can be attributed as the stiffening of network chains due to gel swelling and the conversion from free and unassociated chains into network chains, respectively, leading to an increase in elastic modulus with time.

Hossain, Khandker S.; Nishinari, Katsuyoshi

48

Gum biopsy  

MedlinePLUS

Biopsy - gingiva (gums) ... to eat for a few hours before the biopsy. ... Bleeding from the biopsy site Infection of the gums Soreness ... Avoid brushing the area where the biopsy was performed for 1 week.

49

Nanometric organisation in blends of gellan/xyloglucan hydrogels.  

PubMed

Mixtures of gellan gum (GL) and a xyloglucan (XGJ) extracted from Hymenaea courbaril seeds were prepared in a solution of 0.15molL(-1) NaCl. Rheology measurements revealed that 2.4gL(-1) pure GL formed a brittle hydrogel, and GL-XGJ blends showed improved pseudoplastic character with higher XGJ contents. SAXS analyses showed that the Rg dimensions ranged from 1.3 to 4.9nm, with larger values occurring as the amount of XGJ increased, and diffusion tests indicated that better diffusion of methylene blue dye was obtained in the network with a higher XGJ content. AFM topographic images of the films deposited onto mica revealed fewer heterogeneous surfaces with increased XGJ contents. The water contact angle revealed more hydrophobic character on all of the films, and the wettability decreased with increasing amounts of XGJ. Therefore, the demonstrated benefit of using XGJ blends is the production of a soft material with improved interface properties. PMID:25263863

de Souza, Clayton F; Riegel-Vidotti, Izabel C; Cardoso, Mateus B; Ono, Lucy; Lucyszyn, Neoli; Lubambo, Adriana F; Sens, Camila V; Grein-Iankovski, Aline; Sierakowski, Maria Rita

2014-12-19

50

Process optimization for fabrication of gellan based electrospun nanofibers.  

PubMed

In this investigation, the nanofiber formation ability of gellan, a FDA approved low cost natural polysaccharide, has been achieved for the first time using electrospinning technique. The gellan based ultrafine nanofibers were fabricated by using a blend mixture of gellan with another biodegradable polymer polyvinyl alcohol (PVA). The morphology of resulting gellan-PVA nanofibers was analyzed using field emission scanning electron microscopy (FESEM). The mass ratio of 50:50 for gellan:PVA was recorded as an optimum solution ratio to obtain uniform bead free nanofibers with an average diameter of 40 ± 15.8 nm. Data depicted that among different parameters evaluated, viscosity and the mass ratio of gellan:PVA were the key parameters that influence the nanofiber morphology and diameter. PMID:24815395

Vashisth, Priya; Pruthi, Parul A; Singh, Rajesh P; Pruthi, Vikas

2014-08-30

51

A fronto-parietal network for chewing of gum: a study on human subjects with functional magnetic resonance imaging  

Microsoft Academic Search

The purpose of this study is to investigate human brain activity during mastication using fMRI. Twelve right-handed normal subjects performed two tasks: chewing of gum at their own pace, and imitating the movements of chewing gum. In order to reveal which areas of the brain are more strongly activated while chewing gum, we performed the conjunction analyses of gum chewing

Toshihisa Takada; Tamaki Miyamoto

2004-01-01

52

Chewing-side Preference is Involved in Differential Cortical Activation Patterns during Tongue Movements after Bilateral Gum-chewing: a Functional Magnetic Resonance Imaging Study  

Microsoft Academic Search

Contralateral dominance in the activation of the primary sensorimotor cortex (S1\\/M1) during tongue movements (TMs) has been shown to be associated with a chewing-side preference (CSP). However, little is known about its interaction with chewing-related cortical activation. Functional magnetic resonance imaging was performed before and after gum-chewing in six subjects who exhibited a left CSP to determine the relationship between

H. Shinagawa; T. Ono; E. Honda; T. Sasaki; M. Taira; A. Iriki; T. Kuroda; K. Ohyama

2004-01-01

53

Stomach-specific controlled release gellan beads of acid-soluble drug prepared by ionotropic gelation method.  

PubMed

The purpose of the present work was the development and evaluation of stomach-specific controlled release mucoadhesive drug delivery system prepared by ionotropic gelation of gellan beads, containing acid-soluble drug amoxicillin trihydrate, using 3(2) factorial design with concentration of gellan gum and quantity of drug as variables. The study showed that beads prepared in alkaline cross-linking medium have higher entrapment efficiency than the acidic cross-linking medium. The entrapment efficiency was in the range of 32% to 46% w/w in acidic medium, which increased up to 60% to 90% w/w in alkaline medium. Batches with lowest, medium, and highest drug entrapment were subjected to chitosan coating to form a polyelectrolyte complex film. As polymer concentration increases, entrapment efficiency and particle size increases. Scanning electron microscopy revealed spherical but rough surface due to leaching of drug in acidic cross-linking solution, dense spherical structure in alkaline cross-linking solution, and rough surface of chitosan-coated beads with minor wrinkles. The in vitro drug release up to 7 h in a controlled manner following the Peppas model (r = 0.9998). In vitro and in vivo mucoadhesivity study showed that beads have good mucoadhesivity and more than 85% beads remained adhered to stomach mucosa of albino rat even after 7 h. In vitro growth inhibition study showed complete eradication of Helicobacter pylori. These results indicate that stomach-specific controlled release mucoadhesive system of amoxicillin gellan beads may be useful in H. pylori treatment. PMID:20180053

Narkar, Mrunalini; Sher, Praveen; Pawar, Atmaram

2010-03-01

54

What Happens to Swallowed Gum?  

MedlinePLUS

... gum is harmless. What Exactly Happens to the Gum? Chewing gum is made of either natural or synthetic materials ( ... Too much of anything can be a problem. Chewing gum is hard on dental work and most gums ...

55

Chew that Gum  

NSDL National Science Digital Library

In this quick activity, learners will investigate what happens to bubble gum when it is chewed for 5-10 minutes. First, learners measure the weight of unwrapped pieces on a kitchen scale and recorded. Then learners chew the gum for 5-10 minutes and record the new weight. Learners are encouraged to compare sugarless gum with regular gum as well as different brands. Relates to the linked video, DragonflyTV: Exercise and Memory.

Twin Cities Public Television, Inc.

2005-01-01

56

Chewing gum diarrhea  

Microsoft Academic Search

Summary A 66-year-old woman was found to have intractable diarrhea related to excessive consumption of sugarless chewing gum. The effect of sorbitol on the intestinal tract was felt to be the etiology. Upon cessation of gum utilization, the diarrhea ceased. It is suggested that chewing gum usage be included in medical histories!

Lee D. Goldberg; Norman T. Ditchek

1978-01-01

57

Occurrence, production, and applications of gellan: current state and perspectives  

Microsoft Academic Search

Bacterial exopolysaccharides (EPS) are products of biotechnology that are of high interest due to their rheological properties.\\u000a This is the case of sphingans, a group of structurally related EPS secreted by members of the genus Sphingomonas. Among these, gellan is a multifunctional gelling agent produced in high yields by the non-pathogenic strain Sphingomonas elodea ATCC 31461. In its native form,

Arsenio M. Fialho; Leonilde M. Moreira; Ana Teresa Granja; Alma O. Popescu; Karen Hoffmann; Isabel Sá-Correia

2008-01-01

58

Diffusion of sucrose and aspartame in kappa-carrageenan and gellan gum gels  

Microsoft Academic Search

In the process of sweetness release from the food to the human papillae, diffusion of the sweetener through the food is one of the steps. Information on diffusion behaviour of small molecules like sucrose has been studied mainly in connection with blanching or osmotic processes. In this paper, diffusion constants (D) of both sucrose (100 and 150g\\/l) and aspartame (0.8

S Bayarri; I Rivas; E Costell; L Durán

2001-01-01

59

Gums and Related Polysaccharides  

NASA Astrophysics Data System (ADS)

In the context of carbohydrates, gums are usually considered to be non-starch, water-soluble polysaccharides with commercial importance. When used as ingredients in processed foods, they may be called hydrocolloids . Gums are used because of the functionalities they impart to whatever system or product into which they are incorporated. As with other polymers, their chemical structures, together with the nature of the aqueous environment surrounding the molecules (pH, types and concentrations of salts or other solutes, temperature, shear, etc.) determines the shapes of the molecules; the chemical nature and shapes of the molecules determines the gum's physiochemical properties, and their physicochemical properties determines their functionalities. All gums have one similar property, i. e., the ability to thicken water and aqueous systems, but they may impart different rheological properties to the systems they thicken. Certain gums provide certain functionalities better than do other gums.

Bemiller, James N.

60

The effect of thermal history on the elasticity of K-type gellan gels.  

PubMed

Elasticity of potassium type gellan gels prepared at different thermal histories was examined using dynamic viscoelastic measurements. The storage Young's modulus E' decreased with increasing cooling rate during gelation. Once gel formation occurred, thermal history at lower temperature did not influence the elastic modulus and thermal stability of the gellan gels. On the other hand, thermal history around gelation temperature influenced strongly the elastic modulus and thermal stability of resulting gels. When the gellan solution was kept for a certain time before cooling at a temperature near the gelation temperature, it was found that gels with higher elastic modulus and thermal stability were formed. PMID:25256474

Nitta, Yoko; Yoshimura, Miki; Nishinari, Katsuyoshi

2014-11-26

61

Preparation of the sodium salt of high acyl gellan and characterization of its structure, thermal and rheological behaviors.  

PubMed

This work presents a method to obtain the sodium salt of high acyl gellan (NaHAG) from a commercial preparation, LT-100, by ionic exchange and freeze drying without involving alcohol precipitation to recover the modified macromolecule. NaHAG was characterized by atomic absorption spectrophotometry, attenuated total reflectance Fourier transform infrared spectroscopy, X-ray diffraction and proton nuclear magnetic resonance. In addition, gel viscoelasticity, sol-gel transition temperatures from rheological temperature sweeps and differential scanning calorimetry, of both preparations was examined. Up to 87% of the initial weight of LT-100 was recovered as NaHAG. The sodium ion content in NaHAG was 3.2 times greater than in LT-100 and more than 90% of potassium, calcium and magnesium ions present in the original sample were removed. Transition temperatures of LT-100 were significantly higher than those of NaHAG. However, LT-100 gels were slightly stronger and elastic than NaHAG gels. Characterization data from different analyses suggest that the treatment method makes possible to obtain NaHAG with only slight structure modification with respect to LT-100, and could be advantageously utilized to obtain other monovalent and divalent salt forms of high acyl gellan for use in fundamental studies on its properties in aqueous environment. PMID:24751279

Murillo-Martínez, María M; Tecante, Alberto

2014-08-01

62

Gum Disease and Women  

MedlinePLUS

... Surgery Procedures Find a Periodontist Gum Disease and Women A woman's periodontal health may be impacted by a variety ... turn red and feel tender. Menstruation Occasionally, some women experience menstruation gingivitis. Women with this condition may ...

63

Modification of palm kernel oil esters nanoemulsions with hydrocolloid gum for enhanced topical delivery of ibuprofen  

PubMed Central

Introduction During recent years, there has been growing interest in the use of nanoemulsion as a drug-carrier system for topical delivery. A nanoemulsion is a transparent mixture of oil, surfactant and water with a very low viscosity, usually the product of its high water content. The present study investigated the modification of nanoemulsions with different hydrocolloid gums, to enhanced drug delivery of ibuprofen. The in vitro characterization of the initial and modified nanoemulsions was also studied. Methods A palm kernel oil esters nanoemulsion was modified with different hydrocolloid gums for the topical delivery of ibuprofen. Three different hydrocolloids (gellan gum, xanthan gum, and carrageenan) were selected for use. Ternary phase diagrams were constructed using palm kernel oil esters as the oil, Tween 80 as the surfactant, and water. Nanoemulsions were prepared by phase inversion composition, and were gradually mixed with the freshly prepared hydrocolloids. The initial nanoemulsion and modified nanoemulsions were characterized. The abilities of the nanoemulsions to deliver ibuprofen were assessed in vitro, using a Franz diffusion cell fitted with rat skin. Results No significant changes were observed in droplet size (~16–20 nm) but a significant difference in polydispersity indexes were observed before and after the modification of nanoemulsions using gellan gum, carrageenan, and xanthan gum. The zeta potentials of the initial nanoemulsions (?11.0 mV) increased to ?19.6 mV, ?13.9 mV, and ?41.9 mV, respectively. The abilities of both the initial nanoemulsion (T802) and the modified nanoemulsion to deliver ibuprofen through the skin were evaluated in vitro, using Franz diffusion cells fitted with rat skin. The in vitro permeation data showed that the modified nanoemulsion (Kp value of 55.4 × 10?3 cm · h?1) increased the permeability of ibuprofen 4.40 times over T802 (Kp value of 12.6 × 10?3 cm · h?1) (P < 0.05). Conclusion The modified nanoemulsion may be a promising vehicle to enhance the permeation of ibuprofen for topical delivery. PMID:22973096

Salim, Norazlinaliza; Basri, Mahiran; Rahman, Mohd BA; Abdullah, Dzulkefly K; Basri, Hamidon

2012-01-01

64

Guar Gum Slime  

NSDL National Science Digital Library

In this activity, learners create a gelatinous slime using guar gum powder and borax. Educators can use this simple activity to introduce learners to colloids. This activity page features a fun how-to video that shows learners and educators how to make the slime.

Houston, Children'S M.

2010-01-01

65

Novel plasma-separation dilayer gellan–gellan-sulfate adsorber for direct removal of extra domain A containing fibronectin from the blood of rheumatoid arthritis patients  

Microsoft Academic Search

Rheumatoid arthritis (RA) patients, in whom cryogelation occurs in the presence of heparin, exhibit abnormally high concentrations of extra domain A containing fibronectin [EDA(+)FN] in their plasma. The selective removal of EDA(+)FN from patient blood is therefore of potential therapeutic benefit. Gellan-sulfate is a candidate ligand for the removal of EDA(+)FN due to its high affinity for FN. In this

Keiichi Miyamoto; Katsuyuki Sugihara; Yasunori Abe; Tsutomu Nobori; Masayuki Tokita; Takashi Komai

2002-01-01

66

The Trouble With Bubble Gum  

NSDL National Science Digital Library

Most students are totally unaware of the amount of sugar in bubble gum and don't know that they are literally eating sugar in huge amounts. In this chapter, the author is concerned with finding out what happens to the weight of gum when it is chewed, whic

Konicek-Moran, Richard

2010-03-12

67

Enzymatically-treated guar gums  

Microsoft Academic Search

A method is described of recovering oil from an oil bearing formation by fracturing the step of inserting into the formation, at high pressure, an aqueous composition comprising guar gum in water. The guar gum is first coated and impregnated, while in the solid particulate state, with an aqueous solution of a hydrolytic enzyme.

W. H. Carter; V. K. Srivastava

1987-01-01

68

Chewing Gum—Facts and Fiction: a Review of Gum-Chewing and Oral Health  

Microsoft Academic Search

The world market for chewing gum is estimated to be 560,000 tons per year, representing approximately US $5 billion. Some 374 billion pieces of chewing gum are sold worldwide every year, representing 187 billion hours of gum-chewing if each piece of gum is chewed for 30 minutes. Chewing gum can thus be expected to have an influence on oral health.

T. Imfeld

1999-01-01

69

Schultheiss Chewing gum and salivary hormones 1 Running head: CHEWING GUM AND SALIVARY HORMONES  

E-print Network

Schultheiss Chewing gum and salivary hormones 1 Running head: CHEWING GUM AND SALIVARY HORMONES Effects of sugarless chewing gum as a stimulant on progesterone, cortisol, and testosterone concentrations Chewing gum and salivary hormones 2 Abstract Sugarless chewing gum is a frequently used stimulant

Schultheiss, Oliver C.

70

Periodontal (Gum) Disease Causes, Symptoms, and Treatments  

E-print Network

or AIDS and their treatments can also negatively affect the health of gums. · Medications gums · Painful chewing · Loose teeth · Sensitive teeth · Receding gums or longer appearing teeth AnyPeriodontal (Gum) Disease Causes, Symptoms, and Treatments U.S. DEPARTMENT OF HEALTH AND HUMAN

Bandettini, Peter A.

71

Do It: Chew that Gum!  

NSDL National Science Digital Library

In this science experiment, kids learn that when they chew gum and spit it out, it weighs less than it did originally because the weight of the saliva added is less than the weight of the sugar swallowed.

Tv, Agonfly

72

'Radioactive' decay of chewing gum  

NSDL National Science Digital Library

Student preparation for this assignment is the same as any other class. They are responsible to complete the reading before class. After I have introduced the concept of isotopic decay I have three student volunteers conduct the 'experiment'. One student is the time keeper while the other two students chew gum and weigh the gum at one minute intervals. The only instructions to the students are to chew consistently and to make sure they try to weigh a 'dry' piece of gum. The time keeper is responsible for making sure the gum chewers weigh the sample after each minute of chewing. I enter the data into a spread sheet as it is collected. That way I can discuss the data, explain the equations and ask questions. The entire experiment takes about 25 minutes to complete. After all of the data are collected, we determine half-lives through an iterative process by minimizing the RMS error. This also allows me to introduce error and one way to quantify it. This demonstration could be expanded into a component of a laboratory. Multiple students could chew the same gum to increase the sample size, the could chew different types of gum and measure a different decay constant, they could plot their own graphs, calculate their own decay constants and half-lives, and use a type of candy that does not follow the from exponential decay form. In this form students could form their own hypotheses and test them. There is no additional information that you need to know. I have included a spreadsheet of data from Fall 2007. You can use the same spreadsheet and just adjust for the data from your students. The only thing to keep in mind is that gum will not decay to almost 0 because there is a portion of the gum that will remain. We are only interested in the portion of the gum that does 'decay'. Therefore, I have included a 'mass correction' calculation based on the mass of the gum after the 10 minute mark.

Nichols, Kyle

73

Preparation and in vitro characterization of gellan based floating beads of acetohydroxamic acid for eradication of H. pylori.  

PubMed

Gellan based floating beads of acetohydroxamic acid (AHA) were prepared by the ionotropic gellation method to achieve controlled and sustained drug release for treatment of Helicobacter pylori infection. The prepared beads were evaluated for diameter, surface morphology and encapsulation efficiency. Formulation parameters like concentrations of gellan, chitosan, calcium carbonate and the drug influenced the in vitro drug release characteristics of beads. Drug and polymer interaction studies were carried out using differential scanning calorimetry. Chitosan coating increased encapsulation efficiency of the beads and reduced the initial burst release of the drug from the beads. Kinetic treatment of the drug release data revealed a matrix diffusion mechanism. Prepared floating beads showed good antimicrobial activity (in vitro H. pylori culture) as potent urease inhibitors. In conclusion, an oral dosage form of floating gellan beads containing AHA may form a useful stomach site specific drug delivery system for the treatment of H. pylori infection. PMID:18165186

Rajinikanth, Parauvathanahalli Siddalingam; Mishra, Brahmeshwar

2007-12-01

74

In Vitro Release of Nicotine From Chewing Gum Formulations  

Microsoft Academic Search

Release of nicotine from conventional gums and from gums made using a directly compressible gum base was studied using the European Pharmacopoeia apparatus for testing of medicated chewing gums. It was found that gum base and the method of preparation used in a formulation were important factors when controlling the release of drugs from chewing gum.

Yamini Morjaria; William J Irwin; Paul X Barnett; Rick S Chan; Barbara R Conway

75

21 CFR 582.3336 - Gum guaiac.  

Code of Federal Regulations, 2010 CFR

...Preservatives § 582.3336 Gum guaiac. (a) Product. Gum guaiac. (b) Tolerance. 0.1 percent (equivalent antioxidant activity 0.01 percent). (c) Limitations, restrictions, or explanation. This substance is generally...

2010-04-01

76

21 CFR 582.3336 - Gum guaiac.  

...Preservatives § 582.3336 Gum guaiac. (a) Product. Gum guaiac. (b) Tolerance. 0.1 percent (equivalent antioxidant activity 0.01 percent). (c) Limitations, restrictions, or explanation. This substance is generally...

2014-04-01

77

21 CFR 582.3336 - Gum guaiac.  

Code of Federal Regulations, 2011 CFR

...Preservatives § 582.3336 Gum guaiac. (a) Product. Gum guaiac. (b) Tolerance. 0.1 percent (equivalent antioxidant activity 0.01 percent). (c) Limitations, restrictions, or explanation. This substance is generally...

2011-04-01

78

21 CFR 582.3336 - Gum guaiac.  

Code of Federal Regulations, 2013 CFR

...Preservatives § 582.3336 Gum guaiac. (a) Product. Gum guaiac. (b) Tolerance. 0.1 percent (equivalent antioxidant activity 0.01 percent). (c) Limitations, restrictions, or explanation. This substance is generally...

2013-04-01

79

21 CFR 582.3336 - Gum guaiac.  

Code of Federal Regulations, 2012 CFR

...Preservatives § 582.3336 Gum guaiac. (a) Product. Gum guaiac. (b) Tolerance. 0.1 percent (equivalent antioxidant activity 0.01 percent). (c) Limitations, restrictions, or explanation. This substance is generally...

2012-04-01

80

[Combination of ethylene oxide with gums].  

PubMed

Concerning combinaisons of ethylene oxide with any gums. The combinaisons of ethylene oxide are determined with any gums: tragacanthe, arabic, ceratonia, guar and sterculia. Among the stable compounds obtained with the gums sterculia, the author make mention of chloro-2 éthanol and ethyleneglycol. PMID:1867461

Chaigneau, M

1991-01-01

81

21 CFR 172.695 - Xanthan gum.  

Code of Federal Regulations, 2013 CFR

...3 2013-04-01 2013-04-01 false Xanthan gum. 172.695 Section 172.695 Food and Drugs ...PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.695...

2013-04-01

82

21 CFR 172.695 - Xanthan gum.  

Code of Federal Regulations, 2011 CFR

...3 2011-04-01 2011-04-01 false Xanthan gum. 172.695 Section 172.695 Food and Drugs ...PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.695...

2011-04-01

83

21 CFR 172.695 - Xanthan gum.  

...3 2014-04-01 2014-04-01 false Xanthan gum. 172.695 Section 172.695 Food and Drugs ...PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.695...

2014-04-01

84

21 CFR 172.695 - Xanthan gum.  

Code of Federal Regulations, 2012 CFR

...3 2012-04-01 2012-04-01 false Xanthan gum. 172.695 Section 172.695 Food and Drugs ...PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.695...

2012-04-01

85

21 CFR 172.695 - Xanthan gum.  

Code of Federal Regulations, 2010 CFR

... 3 2010-04-01 2009-04-01 true Xanthan gum. 172.695 Section 172.695 Food and Drugs ...PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.695...

2010-04-01

86

How Much Sugar Is in Bubble Gum?  

NSDL National Science Digital Library

Some of the flavoring in bubble gum is due to the sugar or other sweetener it contains. As gum is chewed, the sugar dissolves and is swallowed. After a piece of gum loses its sweetness, it can be left to dry at room temperature and then the difference between its initial (unchewed) mass and its chewed mass can be used to calculate the percentage of sugar in the gum. This demonstration experiment is used to generate new questions about gums and their ingredients, and students can then design and execute new experiments based on their own questions.

Engineering K-Phd Program

87

Does Your Chewing Gum Lose Its Flavor?  

NSDL National Science Digital Library

Each learner chews a piece of gum until it loses its flavor, and then leaves the gum to dry for several days. By weighing the gum before and after chewing, they can determine the amount of mass lost which corresponds to the amount of sugar in the gum. Learners are then asked to design their own experiment to answer a question of their choosing related to the activity. Learners can follow this with a related activity: "How much Sugar is in Bubble Gum?" Resource contains detailed suggestions to assist learners who are designing their own experiment. Time requirement is intended to be spread over several meetings.

Hebrank, Mary R.

2013-01-01

88

TE activity gum drop atoms  

NSDL National Science Digital Library

This lesson has students building a model of lithium with gum drops and explaining where the model accurately represents the atom and where the model falls short. Enrichment exercises are included such as having groups of students play the parts of subatomic particles to model an atom in the gymnasium.

2006-01-01

89

Gummy vs. Gum (Number Pattern)  

NSDL National Science Digital Library

"In this lesson, students use gummy bears and sticks of gum to discover a number pattern and write an equation that describes it. This lesson should be conducted after students have worked with patterns and one- and two-step equations." from the Beacon Learning Center.

Center, Beacon L.

2009-10-13

90

Rheological properties of lesquerella gum fractions recovered by aqueous extraction  

Microsoft Academic Search

Lesquerella fendleri seeds contain a cross-linked carbohydrate gum with viscoelastic properties that may be used for industrial and edible applications. Laboratory studies compared the rheological behavior of gum isolates obtained from whole seed, defatted hull, and defatted meal fractions. Gum yields and rheological properties were determined for gum isolates from each of these fractions. All gum isolates exhibited positive hysteresis,

Ronald A Holser; Craig J Carriere; Thomas P Abbott

2000-01-01

91

Chewing gum can produce context-dependent effects upon memory  

Microsoft Academic Search

Two experiments examined whether chewing spearmint gum can affect the initial learning or subsequent recall of a word list. Comparing those participants in Experiment 1 who chewed gum at the learning or the recall phases showed that chewing gum at initial learning was associated with superior recall. In addition, chewing gum led to context-dependent effects as a switch between gum

Jess R. Baker; Jessica B. Bezance; Ella Zellaby; John P. Aggleton

2004-01-01

92

Brief Report: Gum Chewing Affects Standardized Math Scores in Adolescents  

ERIC Educational Resources Information Center

Gum chewing has been shown to improve cognitive performance in adults; however, gum chewing has not been evaluated in children. This study examined the effects of gum chewing on standardized test scores and class grades of eighth grade math students. Math classes were randomized to a gum chewing (GC) condition that provided students with gum

Johnston, Craig A.; Tyler, Chermaine; Stansberry, Sandra A.; Moreno, Jennette P.; Foreyt, John P.

2012-01-01

93

Residual Gastric Fluid Volume and Chewing Gum Before Surgery  

Microsoft Academic Search

In this study we sought to determine if chewing gum preoperatively increases gastric fluid volume (GFV) andchangesgastricacidity.Children,5-17yrold,were randomizedtooneofthreegroups:acontrolgroupthat was not given any gum, a group that was given sugar- less bubble gum, and a group that was given sugared bubble gum. Patients in the two gum groups were in- structed to chew their gum for a period of 30 min.

Renate C. Schoenfelder; Chandra M. Ponnamma; David Freyle; Shu-Ming Wang; Zeev N. Kain

2006-01-01

94

Preparation and characterization of antimicrobial wound dressings based on silver, gellan, PVA and borax.  

PubMed

Silver-loaded dressings are designed to provide the same antimicrobial activity of topical silver, with the advantages of a sustained silver release and a reduced number of dressing changes. Moreover, such type of dressing must provide a moist environment, avoiding fiber shedding, dehydration and adherence to the wound site. Here we describe the preparation of a novel silver-loaded dressing based on a Gellan/Hyaff(®) (Ge-H) non woven, treated with a polyvinyl alcohol (PVA)/borax system capable to enhance the entrapment of silver in the dressing and to modulate its release. The new hydrophilic non woven dressings show enhanced water uptake capability and slow dehydration rates. A sustained silver release is also achieved. The antibacterial activity was confirmed on Staphylococcus aureus and Pseudomonas aeruginosa. PMID:22939352

Cencetti, C; Bellini, D; Pavesio, A; Senigaglia, D; Passariello, C; Virga, A; Matricardi, P

2012-10-15

95

Preparation and in vitro antibacterial evaluation of gatifloxacin mucoadhesive gellan system  

PubMed Central

Background and the purpose of the study The poor bioavailability and therapeutic response exhibited by the conventional ophthalmic solutions due to precorneal elimination of the drug may be overcome by the use of mucoadhesive in situ gel forming systems that are instilled as drops into the eye and undergo a sol-gel transition in the cul-de-sac and have good mucoadhesion with ocular mucus layers. The objective of this study was to formulate ophthalmic mucoadhesive system of gatifloxacin (GTN) and to evaluate its in vitro antibacterial potential against, Staphylococcus aureus and Escherichia coli. Methods : Mucoadhesive systems were prepared using gellan combined with sodium carboxymethylcellulose (NaCMC) or sodium alginate to enhance the gel bioadhesion properties. The prepared formulations were evaluated for their gelation, and rheological behaviors, mucoadhesion force, in vitro drug release, and antibacterial activity. Results All formulations in non-physiological or physiological conditions showed pseudoplastic behaviors. Increase in the concentration of mucoadhesive agent enhanced the mucoadhesive force significantly. In vitro release of gatifloxacin from the mucoadhesive system in simulated tear fluid (STF, pH of 7.4) was influenced significantly by the properties and concentration of gellan, sodium carboxymethyl cellulose and sodium alginate. Significant reduction in the total bacterial count was observed between drug solution (control) and mucoadhesive batches against both tested organisms. Major conclusion The developed mucoadhesive system is a viable alternative to conventional eye drops of GTN due to its ability to enhance bioavailability through its longer precorneal residence time and ability to sustain the release of the drug. PMID:22615622

Kesavan, K.; Nath, G.; Pandit, JK.

2010-01-01

96

Guar gum, xanthan gum, and HPMC can define release mechanisms and sustain release of propranolol hydrochloride.  

PubMed

The objectives were to characterize propranolol hydrochloride-loaded matrix tablets using guar gum, xanthan gum, and hydroxypropylmethylcellulose (HPMC) as rate-retarding polymers. Tablets were prepared by wet granulation using these polymers alone and in combination, and physical properties of the granules and tablets were studied. Drug release was evaluated in simulated gastric and intestinal media. Rugged tablets with appropriate physical properties were obtained. Empirical and semi-empirical models were fit to release data to elucidate release mechanisms. Guar gum alone was unable to control drug release until a 1:3 drug/gum ratio, where the release pattern matched a Higuchi profile. Matrix tablets incorporating HPMC provided near zero-order release over 12 h and erosion was a contributing mechanism. Combinations of HPMC with guar or xanthan gum resulted in a Higuchi release profile, revealing the dominance of the high viscosity gel formed by HPMC. As the single rate-retarding polymer, xanthan gum retarded release over 24 h and the Higuchi model best fit the data. When mixed with guar gum, at 10% or 20% xanthan levels, xanthan gum was unable to control release. However, tablets containing 30% guar gum and 30% xanthan gum behaved as if xanthan gum was the sole rate-retarding gum and drug was released by Fickian diffusion. Release profiles from certain tablets match 12-h literature profiles and the 24-h profile of Inderal(®) LA. The results confirm that guar gum, xanthan gum, and HPMC can be used for the successful preparation of sustained release oral propranolol hydrochoride tablets. PMID:21174179

Mughal, Muhammad Akhlaq; Iqbal, Zafar; Neau, Steven Henry

2011-03-01

97

Problem Solving: Bubble Gum Contest  

NSDL National Science Digital Library

This professional development video clip presents students engaged in The Common Core Practice Standard #1âMake sense of problems and persevere in solving them. The learners gather data for a bubble gum contest, as part of a larger activity involving recording data and writing up results. Students understand the problem and persevere with the task as they independently go to other classrooms to conduct their survey. Additional resources include a video transcript, teaching tips, and a link to a professional development reflection activity based upon the video.

Boston, Wghb

2013-01-01

98

Chewing gum moderates the vigilance decrement.  

PubMed

We examine the impact of chewing gum on a Bakan-type vigilance task that requires the continual updating of short-term order memory. Forty participants completed a 30-min auditory Bakan-task either with, or without, the requirement to chew gum. Self-rated measures of mood were taken both pre- and post-task. As expected, the vigilance task produced a time-dependent performance decrement indexed via decreases in target detections and lengthened correct reaction times (RTs), and a reduction in post-task self-rated alertness scores. The declines in both performance and subjective alertness were attenuated in the chewing-gum group. In particular, correct RTs were significantly shorter following the chewing of gum in the latter stages of the task. Additionally, the gradients of decline for target detection and incline for correct RTs were both attenuated for the chewing-gum group. These findings are consistent with the data of Tucha and Simpson (2011), Appetite, 56, 299-301, who showed beneficial effects of chewing gum in the latter stages of a 30 min visual attention task, and extend their data to a task that necessitates the continuous updating of order memory. It is noteworthy that our data contradict the claim (Kozlov, Hughes, & Jones, 2012, Q. J. Exp. Psychology, 65, 501-513) that chewing gum negatively impacts short-term memory task performance. PMID:24754809

Morgan, Kate; Johnson, Andrew J; Miles, Christopher

2014-05-01

99

21 CFR 184.1333 - Gum ghatti.  

...Indian gum) is an exudate from wounds in the bark of Anogeissus latifolia, a large tree found in the dry deciduous forests of India and Ceylon. (b) The ingredient complies with the following specifications: (1) Viscosity of a 1-percent...

2014-04-01

100

Comparing Fractions: Bubble Gum Blowing Contest  

NSDL National Science Digital Library

In this interactive activity adapted from Anneberg Learner’s Teaching Math Grades 3–5, compare fractions on number lines to determine which class of students wins bubble-gum-blowing contests.

Foundation, Wgbh E.

2012-06-29

101

Does Your Chewing Gum Lose Its Sweetness?  

NSDL National Science Digital Library

In the first part of the activity, each student chews a piece of gum until it loses its sweetness, and then leaves the gum to dry for several days before weighing it to determine the amount of mass lost. This mass corresponds to the amount of sugar in the gum, and can be compared to the amount stated on the package label. In the second part of the activity, students work in groups to design and conduct new experiments based on questions of their own choosing. These questions arise naturally from observations during the first experiment, and from students' own experiences with and knowledge of the many varieties of chewing and bubble gums available.

Engineering K-Ph.d. Program

102

Scientific Method Lab Using Bubble Gum  

NSDL National Science Digital Library

This activity is a lab investigation where students gather data which compares 2 types of bubble gum, while learning to use the scientific method to collect qualitative and quantitative data using SI units.

103

Fractionation of Mastic Gum in Relation to Antimicrobial Activity  

PubMed Central

Mastic gum is a viscous light-green liquid obtained from the bark of Pistacia lentiscus var. chia. which belongs to the Anacardiaceae family. The gum has been fractionated to investigate the antimicrobial activity of the whole gum and its fractions against various strains of Helicobacter pylori. The polymeric gum fraction was separated from the essential oil and the resin (trunk exudates without essential oil) to assess and compare the anti-H. pylori activity of the polymer fraction against lower molecular weight fractions, the gum itself and masticated gum. The polymer fraction was also oxidized and assessed for antimicrobial activity.

Sharifi, Mohammad Sharif; Hazell, Stuart Loyd

2009-01-01

104

21 CFR 184.1343 - Locust (carob) bean gum.  

...bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree, Ceratonia siliqua (Linne...evergreen tree, with lesser quantities of seed coat and germ. (b) The...

2014-04-01

105

Manilkara zapota (Linn.) Seeds: A Potential Source of Natural Gum.  

PubMed

Mucilage isolated from seeds of Manilkara zapota (Linn.) P. Royen syn. is a plant growing naturally in the forests of India. This mucilage is yet to be commercially exploited, and characterized as polymer. Various physicochemical methods like particle size analysis, scanning electron microscopy, thermal analysis, gel permeation chromatography, X-ray diffraction spectrometry, zeta potential, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy have been employed to characterize this gum in the present study. Particle size analyses suggest that mucilage has particle size in nanometer. Scanning electron microscopy analysis suggests that the mucilage has irregular particle size. The glass transition temperature of the gum was observed to be 138°C and 136°C by differential scanning calorimetry and differential thermal analysis, respectively. The thermogravimetric analysis suggested that mucilage had good thermal stability. The average molecular weight of mucilage was determined to be 379180, by gel permeation chromatography, while the viscosity of mucilage was observed to be 219.1 cP. The X-ray diffraction spectrometry pattern of the mucilage indicates a completely amorphous structure. Elemental analysis of the gum revealed the contents of carbon, hydrogen, nitrogen, and sulfur to be 80.9 (%), 10.1 (%), 1.58 (%), and 512 (mg/kg), respectively. Mucilage had specific content of calcium, magnesium, potassium, lower concentrations of aluminum, cadmium, cobalt, lead, and nickel. The major functional groups identified from FT-IR spectrum include 3441?cm(-1) (-OH), 1660?cm(-1) (Alkenyl C-H & C=C Stretch), 1632?cm(-1) (-COO-), 1414?cm(-1) (-COO-), and 1219?cm(-1) (-CH3CO). Analysis of mucilage by paper chromatography and 1D NMR, indicated the presence of rhamnose, xylose, arabinose, mannose, and fructose. PMID:24729907

Singh, Sudarshan; Bothara, Sunil B

2014-01-01

106

21 CFR 172.615 - Chewing gum base.  

Code of Federal Regulations, 2012 CFR

...Drugs 3 2012-04-01 2012-04-01 false Chewing gum base. 172.615 Section 172.615 Food and Drugs...FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.615...

2012-04-01

107

21 CFR 172.615 - Chewing gum base.  

Code of Federal Regulations, 2010 CFR

...Drugs 3 2010-04-01 2009-04-01 true Chewing gum base. 172.615 Section 172.615 Food and Drugs...FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.615...

2010-04-01

108

21 CFR 172.615 - Chewing gum base.  

Code of Federal Regulations, 2011 CFR

...Drugs 3 2011-04-01 2011-04-01 false Chewing gum base. 172.615 Section 172.615 Food and Drugs...FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.615...

2011-04-01

109

Oral bolus kneading and shaping measured with chewing gum  

Microsoft Academic Search

A masticatory test using two-colored chewing gum is presented and analyzed. Two separate parameters of chewing were studied on the same chewing gum bolus after 10 strokes of oral preparation, color mixing, and bolus shaping. The two parameters were evaluated in indices 1–5. A test series should preferably contain three chewing gums, and color mixing can be evaluated on six

Birgitta Liedberg; Bengt Öwall

1995-01-01

110

21 CFR 184.1330 - Acacia (gum arabic).  

Code of Federal Regulations, 2013 CFR

...Substances Affirmed as GRAS § 184.1330 Acacia (gum arabic). (a) Acacia (gum arabic) is the dried gummy exudate from stems...thickener, § 170.3(o)(28) of this chapter. Chewing gum, § 170.3(n)(6) of this chapter...

2013-04-01

111

21 CFR 184.1330 - Acacia (gum arabic).  

Code of Federal Regulations, 2012 CFR

...Substances Affirmed as GRAS § 184.1330 Acacia (gum arabic). (a) Acacia (gum arabic) is the dried gummy exudate from stems...thickener, § 170.3(o)(28) of this chapter. Chewing gum, § 170.3(n)(6) of this chapter...

2012-04-01

112

21 CFR 184.1330 - Acacia (gum arabic).  

Code of Federal Regulations, 2010 CFR

...Substances Affirmed as GRAS § 184.1330 Acacia (gum arabic). (a) Acacia (gum arabic) is the dried gummy exudate from stems...thickener, § 170.3(o)(28) of this chapter. Chewing gum, § 170.3(n)(6) of this chapter...

2010-04-01

113

21 CFR 184.1330 - Acacia (gum arabic).  

Code of Federal Regulations, 2011 CFR

...Substances Affirmed as GRAS § 184.1330 Acacia (gum arabic). (a) Acacia (gum arabic) is the dried gummy exudate from stems...thickener, § 170.3(o)(28) of this chapter. Chewing gum, § 170.3(n)(6) of this chapter...

2011-04-01

114

21 CFR 172.615 - Chewing gum base.  

...Drugs 3 2014-04-01 2014-04-01 false Chewing gum base. 172.615 Section 172.615 Food and Drugs...FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.615...

2014-04-01

115

21 CFR 184.1330 - Acacia (gum arabic).  

...Substances Affirmed as GRAS § 184.1330 Acacia (gum arabic). (a) Acacia (gum arabic) is the dried gummy exudate from stems...thickener, § 170.3(o)(28) of this chapter. Chewing gum, § 170.3(n)(6) of this chapter...

2014-04-01

116

21 CFR 172.615 - Chewing gum base.  

Code of Federal Regulations, 2013 CFR

...Drugs 3 2013-04-01 2013-04-01 false Chewing gum base. 172.615 Section 172.615 Food and Drugs...FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Gums, Chewing Gum Bases and Related Substances § 172.615...

2013-04-01

117

The Gum Nebula and Related Problems  

NASA Technical Reports Server (NTRS)

Proceedings of a symposium concerning the Gum Nebula (GN) and related topics are reported. Papers presented include: Colin Gum and the discovery of the GN; identification of the GN as the fossil Stromgren sphere of Vela X Supernova; size and shape of GN; formation of giant H-2 regions following supernova explosions; radio astronomy Explorer 1 observations of GN; cosmic ray effects in the GN; low intensity H beta emission from the interstellar medium; and how to recognize and analyze GN. Astronomical charts and diagrams are included.

1973-01-01

118

Design, formulation and evaluation of caffeine chewing gum  

PubMed Central

Background: Caffeine which exists in drinks such as coffee as well as in drug dosage forms in the global market is among the materials that increase alertness and decrease fatigue. Compared to other forms of caffeine, caffeine gum can create faster and more prominent effects. In this study, the main goal is to design a new formulation of caffeine gum with desirable taste and assess its physicochemical properties. Materials and Methods: Caffeine gum was prepared by softening of gum bases and then mixing with other formulation ingredients. To decrease the bitterness of caffeine, sugar, aspartame, liquid glucose, sorbitol, manitol, xylitol, and various flavors were used. Caffeine release from gum base was investigated by mechanical chewing set. Content uniformity test was also performed on the gums. The gums were evaluated in terms of organoleptic properties by the Latin-Square design at different stages. Results: After making 22 formulations of caffeine gums, F11 from 20 mg caffeine gums and F22 from 50 mg caffeine gums were chosen as the best formulation in organoleptic properties. Both types of gum released about 90% of their own drug content after 30 min. Drug content of 20 and 50 mg caffeine gum was about 18.2-21.3 mg and 45.7-53.6 mg respectively. Conclusion: In this study, 20 and 50 mg caffeine gums with suitable and desirable properties (i.e., good taste and satisfactory release) were formulated. The best flavor for caffeine gum was cinnamon. Both kinds of 20 and 50 mg gums succeeded in content uniformity test. PMID:24223387

Aslani, Abolfazl; Jalilian, Fatemeh

2013-01-01

119

Potential utilization of guar gum industrial waste in vermicompost production  

Microsoft Academic Search

Recycling of guar gum industrial waste through vermitechnology was studied under laboratory conditions by using composting earthworm Perionyx excavatus (Perrier). Three different combination of guar gum industrial waste namely guar gum industrial waste:cow dung:saw dust in 40:30:30 ratio (T1), guar gum industrial waste:cow dung:saw dust in 60:20:20 ratio (T2), and guar gum industrial waste:cow dung:saw dust in 75:15:10 ratio (T3)

Surendra Suthar

2006-01-01

120

Guar Gum, Xanthan Gum, and HPMC Can Define Release Mechanisms and Sustain Release of Propranolol Hydrochloride  

Microsoft Academic Search

The objectives were to characterize propranolol hydrochloride-loaded matrix tablets using guar gum, xanthan gum, and hydroxypropylmethylcellulose\\u000a (HPMC) as rate-retarding polymers. Tablets were prepared by wet granulation using these polymers alone and in combination,\\u000a and physical properties of the granules and tablets were studied. Drug release was evaluated in simulated gastric and intestinal\\u000a media. Rugged tablets with appropriate physical properties were

Muhammad Akhlaq Mughal; Zafar Iqbal; Steven Henry Neau

2011-01-01

121

Proteoglycans from the gum exudate of myrrh  

Microsoft Academic Search

The watersoluble gum fraction of myrrh (40% w\\/w), has been found to comprise of a heterodisperse mixture of proteoglycans with dominating amounts of uronic acid rich polymers. The major fraction (70% w\\/w) was a proteoglycan (Mr ~200 000) with protein content of 10% and Hyp as the main amino acid (40%). Structural investigations using mild acid hydrolysis, Smith degradation and

R. M. Wiendl; B. M. Müller; G. Franz

1995-01-01

122

ESR spectroscopic properties of irradiated gum Arabic.  

PubMed

Electron spin resonance (ESR) spectra of irradiated gum Arabic with doses between 0.5 and 5 kGy were studied. A linear relationship between the absorbed dose and the intensities of the ESR spectra was observed. ESR spectra of irradiated gum Arabic showed a decay of relative concentrations of free radicals originated by radiation and the production of at least two species of free radicals with half-times: 3.3 and 125.4 h. The results of spectral simulations for these radical groups were giso=2.0046; A=1.2 mT and gx=gy=2.0062, gz=2.0025. Hydration and dehydration of irradiated gum Arabic returns the ESR spectrum to its initial state before irradiation. The results show that ESR can be used as simple and reliable method to detect irradiated gum Arabic up to 60 days after initial radiation with doses on the order of 5 kGy. PMID:23870902

Leonor, S J; Gómez, J A; Kinoshita, A; Calandreli, I; Tfouni, E; Baffa, O

2013-12-01

123

Clinical use of nicotine chewing-gum  

Microsoft Academic Search

Nicotine chewing-gum has recently become available to doctors in Britain for use as an aid to giving up smoking. It produces blood nicotine concentrations similar to tobacco smoking and so relieves symptoms of nicotine withdrawal. Owing partly to the slower rate of absorption of nicotine through the buccal mucosa, however, it does not reproduce the pleasure of cigarette smoking. Indeed,

M A Russell; M Raw; M J Jarvis

1980-01-01

124

Preparation and evaluation of release characteristics of 3TabGum, a novel chewing device  

Microsoft Academic Search

A new chewing gum device in the form of a three layers tablet (3TabGum) has been developed. The new drug delivery system is obtained, at room temperature, by direct compression using conventional pharmaceutical equipment. Basically, the resulting chewing gum tablets comprise a gum core combined with two protective antiadherent external layers, which prevent gum adhesion to the punches of the

L. Maggi; L. Segale; S. Conti; E. Ochoa Machiste; A. Salini; U. Conte

2005-01-01

125

Linear Mixed Models: Gum and Beyond  

NASA Astrophysics Data System (ADS)

In Annex H.5, the Guide to the Evaluation of Uncertainty in Measurement (GUM) [1] recognizes the necessity to analyze certain types of experiments by applying random effects ANOVA models. These belong to the more general family of linear mixed models that we focus on in the current paper. Extending the short introduction provided by the GUM, our aim is to show that the more general, linear mixed models cover a wider range of situations occurring in practice and can be beneficial when employed in data analysis of long-term repeated experiments. Namely, we point out their potential as an aid in establishing an uncertainty budget and as means for gaining more insight into the measurement process. We also comment on computational issues and to make the explanations less abstract, we illustrate all the concepts with the help of a measurement campaign conducted in order to challenge the uncertainty budget in calibration of accelerometers.

Arendacká, Barbora; Täubner, Angelika; Eichstädt, Sascha; Bruns, Thomas; Elster, Clemens

2014-04-01

126

Evaluation of Sterculia foetida Gum as Controlled Release Excipient  

Microsoft Academic Search

The purpose of the research was to evaluate Sterculia foetida gum as a hydrophilic matrix polymer for controlled release preparation. For evaluation as a matrix polymer; characterization\\u000a of Sterculia foetida gum was done. Viscosity, pH, scanning electronmicrographs were determined. Different formulation aspects considered were:\\u000a gum concentration (10–40%), particle size (75–420 ?m) and type of fillers and those for dissolution studies; pH,

Amit Ashok Chivate; Sushilkumar Sharatchandra Poddar; Shajahan Abdul; Gaurav Savant

2008-01-01

127

Plasma nicotine levels after cigarette smoking and chewing nicotine gum  

Microsoft Academic Search

Plasma nicotine levels were measured over seven hours of smoking cigarettes (1-2 mg nicotine) in a single subject under standardised conditions, and were compared with the levels obtained from chewing-gum containing either 2 mg or 4 mg nicotine. Levels comparable to those resulting from smoking were not obtained with the 2-mg gum, but peak levels on the 4-mg gum averaged

M A Russell; C Feyerabend; P V Cole

1976-01-01

128

Validating the applicability of the GUM procedure  

NASA Astrophysics Data System (ADS)

This paper is directed at practitioners seeking a degree of assurance in the quality of the results of an uncertainty evaluation when using the procedure in the Guide to the Expression of Uncertainty in Measurement (GUM) (JCGM 100?:?2008). Such assurance is required in adhering to general standards such as International Standard ISO/IEC 17025 or other sector-specific standards. We investigate the extent to which such assurance can be given. For many practical cases, a measurement result incorporating an evaluated uncertainty that is correct to one significant decimal digit would be acceptable. Any quantification of the numerical precision of an uncertainty statement is naturally relative to the adequacy of the measurement model and the knowledge used of the quantities in that model. For general univariate and multivariate measurement models, we emphasize the use of a Monte Carlo method, as recommended in GUM Supplements 1 and 2. One use of this method is as a benchmark in terms of which measurement results provided by the GUM can be assessed in any particular instance. We mainly consider measurement models that are linear in the input quantities, or have been linearized and the linearization process is deemed to be adequate. When the probability distributions for those quantities are independent, we indicate the use of other approaches such as convolution methods based on the fast Fourier transform and, particularly, Chebyshev polynomials as benchmarks.

Cox, Maurice G.; Harris, Peter M.

2014-08-01

129

Guar gum: processing, properties and food applications-A Review.  

PubMed

Guar gum is a novel agrochemical processed from endosperm of cluster bean. It is largely used in the form of guar gum powder as an additive in food, pharmaceuticals, paper, textile, explosive, oil well drilling and cosmetics industry. Industrial applications of guar gum are possible because of its ability to form hydrogen bonding with water molecule. Thus, it is chiefly used as thickener and stabilizer. It is also beneficial in the control of many health problems like diabetes, bowel movements, heart disease and colon cancer. This article focuses on production, processing, composition, properties, food applications and health benefits of guar gum. PMID:24587515

Mudgil, Deepak; Barak, Sheweta; Khatkar, Bhupendar Singh

2014-03-01

130

Antiectoparasitic activity of the gum resin, gum haggar, from the East African plant, Commiphora holtziana.  

PubMed

The mechanism of ixodid tick (Acari: Ixodidae) repellency by gum haggar, a resin produced by Commiphora holtziana (Burseraceae), was investigated by evaluating activity against the cattle tick, Boophilus microplus. In an arena bioassay, a hexane extract of the resin of C. holtziana exhibited a repellent effect lasting up to 5h. The hydrocarbon fraction of the resin extract was shown to account for the repellent activity, and was analysed by coupled gas chromatography-mass spectrometry (GC-MS). Major sesquiterpene hydrocarbons were tentatively identified as germacrene-D, delta-elemene and beta-bourbonene. The identity and stereochemistry of the former compound was confirmed as the (+)-isomer by peak enhancement using enantioselective GC, whereas the latter 2 compounds, which are most likely degradation products of germacrene-type precursors, were identified through isolation by preparative gas chromatography followed by microprobe-NMR spectroscopy. GC comparison of gum haggar with another resin, C. myrrha, which was inactive in the tick bioassay, showed that the latter contained much lower levels of these hydrocarbons. To assess the suitability of the gum haggar resin as a general acarine repellent, further tests were made on a major acarine pest of European and US animal husbandry systems, the red poultry mite, Dermanyssus gallinae (Acari: Dermanyssidae). Gum haggar extract, and the isolated hydrocarbon fraction, showed strong repellent effects in an olfactometer assay, and again gum myrrh showed no effect. These findings provide a scientific basis for the observed anti-tick properties of gum haggar, and demonstrate the potential for its development as a general acarine repellent for use in animal husbandry systems. PMID:18402993

Birkett, Michael A; Abassi, Sate Al; Kröber, Thomas; Chamberlain, Keith; Hooper, Antony M; Guerin, Patrick M; Pettersson, Jan; Pickett, John A; Slade, Robin; Wadhams, Lester J

2008-05-01

131

Effects of sugarless chewing gum as a stimulant on progesterone, cortisol, and testosterone concentrations assessed in saliva  

E-print Network

Effects of sugarless chewing gum as a stimulant on progesterone, cortisol, and testosterone Testosterone Cortisol Progesterone Chewing gum Saliva collection Sugarless chewing gum is a frequently used conditions (gum, no gum) as well as in a saliva pool and water, either untreated or treated with chewing gum

Schultheiss, Oliver C.

132

Effect of gums on the rheological characteristics and microstructure of acid-induced SPI-gum mixed gels.  

PubMed

The effect of addition of xanthan gum (XG) and guar gum (GG) on the rheological properties and microstructure of glucono-?-lactone induced soy protein isolate (SPI)-XG gels and SPI-GG gels was investigated using steady and dynamic rheological tests, creep-recovery and confocal laser scanning microscopy (CLSM). Results showed that the apparent viscosity of SPI-gum (XG, GG) mixed solutions increased with the increase in the gum (XG, GG) concentration. The storage (G') and loss (G?) moduli of SPI-gum (XG, GG) mixed gels increased in the presence and increase in the gum (XG, GG) concentration. The Burger's model fitted the creep recovery data well (R(2)>0.919) and showed that both the instantaneous and equilibrium (retarded) elastic components of this model increased with the increase in SPI and gum concentrations. The proportion occupied by gum in mixed gels was found to increase with the increase in the concentration of gums which increased the density of protein aggregates in the mixed gels. PMID:24751263

Chang, Yuan-Yuan; Li, Dong; Wang, Li-Jun; Bi, Chong-Hao; Adhikari, Benu

2014-08-01

133

Immunological and functional properties of the exudate gum from northwestern Mexican mesquite (Prosopis spp.) in comparison with gum arabic.  

PubMed

A comparison between the fine structural features of exudate gum from mesquite (Prosopis spp.) indigenous to NW Mexico and commercial gum arabic from Acacia spp. was achieved by means of immunological techniques. Their functional properties were compared from the ability to form oil-in-water emulsions and encapsulate cold press orange peel essential oil by spray drying. Fine comparison of the antigenic compounds in both materials against polyclonal rabbit antibodies, showed that the carbohydrate-rich components with slow mobility of mesquite gum are closely related to the faster ones of gum arabic. Also, close identity was observed for the components in the proteic fraction of both gums. Similar tannin concentrations were found in both materials (approximately 0.43%) with only dark coloured samples bearing higher amounts (approximately 1.9%). Gum arabic retained nearly 100% of the quantity of orange peel essential oil emulsified in water before spray drying, while mesquite gum did so for 90.6% of the citrus oil. From these results it is believed that mesquite gum might be a suitable replacement of gum arabic in arid regions of the world were Prosopis trees have widespread occurrence. PMID:9283013

Goycoolea, F M; Calderón de la Barca, A M; Balderrama, J R; Valenzuela, J R

1997-08-01

134

Characterization and in vitro drug release studies of a natural polysaccharide Terminalia catappa gum (Badam gum).  

PubMed

The main objective of the present study is the physicochemical characterization of naturally available Terminalia catappa gum (Badam gum [BG]) as a novel pharmaceutical excipient and its suitability in the development of gastroretentive floating drug delivery systems (GRFDDS) to retard the drug for 12 h when the dosage form is exposed to gastrointestinal fluids in the gastric environment. As BG was being explored for the first time for its pharmaceutical application, physicochemical, microbiological, rheological, and stability studies were carried out on this gum. In the present investigation, the physicochemical properties, such as micromeritic, rheological, melting point, moisture content, pH, swelling index, water absorption, and volatile acidity, were evaluated. The gum was characterized by scanning electron microscopy, differential scanning calorimetry (DSC), powder X-ray diffraction studies (PXRD), and Fourier transform infrared spectroscopy (FTIR). Gastroretentive floating tablets of BG were prepared with the model drug propranolol HCl by direct compression methods. The prepared tablets were evaluated for all their physicochemical properties, in vitro buoyancy, in vitro drug release, and rate order kinetics. PBG 04 was selected as an optimized formulation based on its 12-h drug release and good buoyancy characteristics. The optimized formulation was characterized with FTIR, DSC, and PXRD studies, and no interaction between the drug and BG was found. Thus, the study confirmed that BG might be used in the gastroretentive drug delivery system as a release-retarding polymer. PMID:23090110

Meka, Venkata Srikanth; Nali, Sreenivasa Rao; Songa, Ambedkar Sunil; Kolapalli, Venkata Ramana Murthy

2012-12-01

135

Chewing gum differentially affects aspects of attention in healthy subjects  

Microsoft Academic Search

In a study published previously in this journal (Wilkinson et al., 2002), the effect of chewing gum on cognitive functioning was examined. The results of this study indicated that chewing a piece of gum results in an improvement of working memory and of both immediate and delayed recall of words but not of attention. In the present study, memory and

Oliver Tucha; Lara Mecklinger; Kerstin Maier; Marianne Hammerl; Klaus W Lange

2004-01-01

136

Gum Arabic as a Cause of Occupational Allergy  

PubMed Central

Background. Gum arabic is a potential sensitizer in food industry. Methods. We examined 11 candy factory workers referred to examinations due to respiratory and skin symptoms paying attention to exposure and sensitization to gum arabic. Skin tests, pulmonary function tests, and respiratory provocation tests were carried out as indicated by the symptoms and findings. Results. Occupational asthma, caused by gum arabic was diagnosed in 4/11 candy factory workers and two of them had also occupational contact urticaria and one had occupational rhinitis. One of them had oral symptoms associated with ingestion of products containing gum arabic. Conclusions. Airborne exposure to gum arabic may cause sensitization leading to allergic rhinitis, asthma, and urticaria. PMID:21747872

Viinanen, Arja; Salokannel, Maija; Lammintausta, Kaija

2011-01-01

137

Chemoenzymatic synthesis and hydrogelation of amylose-grafted xanthan gums.  

PubMed

This paper reports the chemoenzymatic synthesis of an amylose-grafted xanthan gum. An amine-functionalized maltooligosaccharide was chemically introduced to xanthan gum by condensation with its carboxylates using a condensing agent to produce a maltooligosaccharide-grafted xanthan gum. Then, a phosphorylase-catalyzed enzymatic polymerization of glucose 1-phosphate from the graft chain ends on the xanthan gum derivative was performed, giving an amylose-grafted xanthan gum. Furthermore, the product formed a gel with an ionic liquid, which was converted into a hydrogel with high water content by replacement of the ionic liquid with water. The ionically cross-linked hydrogel was also provided by soaking the primary formed hydrogel in FeCl(3) aqueous solution. The mechanical properties of the resulting hydrogels were evaluated by compressive testing. PMID:21689681

Arimura, Takuya; Omagari, Yuji; Yamamoto, Kazuya; Kadokawa, Jun-ichi

2011-11-01

138

Design, formulation and evaluation of nicotine chewing gum  

PubMed Central

Background: Nicotine replacement therapy (NRT) can help smokers to quit smoking. Nicotine chewing gum has attracted the attention from pharmaceutical industries to offer it to consumers as an easily accessible NRT product. However, the bitter taste of such gums may compromise their acceptability by patients. This study was, therefore, designed to develop 2 and 4 mg nicotine chewing gums of pleasant taste, which satisfy the consumers the most. Materials and Methods: Nicotine, sugar, liquid glucose, glycerin, different sweetening and taste-masking agents, and a flavoring agent were added to the gum bases at appropriate temperature. The medicated gums were cut into pieces of suitable size and coated by acacia aqueous solution (2% w/v), sugar dusting, followed by acacia–sugar–calcium carbonate until a smooth surface was produced. The gums’ weight variation and content uniformity were determined. The release of nicotine was studied in pH 6.8 phosphate buffer using a mastication device which simulated the mastication of chewing gum in human. The Latin Square design was used for the evaluation of organoleptic characteristics of the formulations at different stages of development. Results: Most formulations released 79–83% of their nicotine content within 20 min. Nicotine-containing sugar-coated gums in which aspartame as sweetener and cherry and eucalyptus as flavoring agents were incorporated (i.e. formulations F19-SC and F20-SC, respectively) had optimal chewing hardness, adhering to teeth, and plumpness characteristics, as well as the most pleasant taste and highest acceptability to smokers. Conclusion: Taste enhancement of nicotine gums was achieved where formulations comprised aspartame as the sweetener and cherry and eucalyptus as the flavoring agents. Nicotine gums of pleasant taste may, therefore, be used as NRT to assist smokers quit smoking. PMID:23326788

Aslani, Abolfazl; Rafiei, Sahar

2012-01-01

139

Evaluation of Sterculia foetida gum as controlled release excipient.  

PubMed

The purpose of the research was to evaluate Sterculia foetida gum as a hydrophilic matrix polymer for controlled release preparation. For evaluation as a matrix polymer; characterization of Sterculia foetida gum was done. Viscosity, pH, scanning electronmicrographs were determined. Different formulation aspects considered were: gum concentration (10-40%), particle size (75-420 microm) and type of fillers and those for dissolution studies; pH, and stirring speed were considered. Tablets prepared with Sterculia foetida gum were compared with tablets prepared with Hydroxymethylcellulose K15M. The release rate profiles were evaluated through different kinetic equations: zero-order, first-order, Higuchi, Hixon-Crowell and Korsemeyer and Peppas models. The scanning electronmicrographs showed that the gum particles were somewhat triangular. The viscosity of 1% solution was found to be 950 centipoise and pH was in range of 4-5. Suitable matrix release profile could be obtained at 40% gum concentration. Higher sustained release profiles were obtained for Sterculia foetida gum particles in size range of 76-125 microm. Notable influences were obtained for type of fillers. Significant differences were also observed with rotational speed and dissolution media pH. The in vitro release profiles indicated that tablets prepared from Sterculia foetida gum had higher retarding capacity than tablets prepared with Hydroxymethylcellulose K15M prepared tablets. The differential scanning calorimetry results indicated that there are no interactions of Sterculia foetida gum with diltiazem hydrochloride. It was observed that release of the drug followed through surface erosion and anomalous diffusion. Thus, it could be concluded that Sterculia foetida gum could be used a controlled release matrix polymer. PMID:18446482

Chivate, Amit Ashok; Poddar, Sushilkumar Sharatchandra; Abdul, Shajahan; Savant, Gaurav

2008-01-01

140

Microbead design for sustained drug release using four natural gums.  

PubMed

Four natural gums, namely albizia, cissus, irvingia and khaya gums have been characterized and evaluated as polymers for the formulation of microbeads for controlled delivery of diclofenac sodium. The natural gums were characterized for their material properties using standard methods. Diclofenac microbeads were prepared by ionotropic gelation using gel blends of the natural gums and sodium alginate at different ratios and zinc chloride solution (10%w/v) as the crosslinking agent. The microbeads were assessed using SEM, swelling characteristics, drug entrapment efficiencies and release properties. Data obtained from in vitro dissolution studies were fitted to various kinetic equations to determine the kinetics and mechanisms of drug release, and the similarity factor, f2, was used to compare the different formulations. The results showed that the natural gum polymers varied considerably in their material properties. Spherical and discrete microbeads with particle size of 1.48-2.41 ?m were obtained with entrapment efficiencies of 44.0-71.3%w/w. Drug release was found to depend on the type and concentration of polymer gum used with formulations containing gum:alginate ratio of 3:1 showing the highest dissolution times. Controlled release of diclofenac was obtained over for 5h. Drug release from the beads containing the polymer blends of the four gums and sodium alginate fitted the Korsmeyer-Peppas model which appeared to be dependent on the nature of natural gum in the polymer blend while the beads containing alginate alone fitted the Hopfenberg model. Beads containing albizia and cissus had comparable release profiles to those containing khaya (f2>50). The results suggest that the natural gums could be potentially useful for the formulation controlled release microbeads. PMID:23541556

Odeku, Oluwatoyin A; Okunlola, Adenike; Lamprecht, Alf

2013-07-01

141

Rheological characterization of jet-cooked Lesquerella fendleri seed gum and cornstarch solutions  

Microsoft Academic Search

Lesquerella is a potential new seed crop that contains hydroxy fatty acid triglycerides and approximately 15% seed coat gums. The polysaccharide gum of the Lesquerella fendleri seed was isolated and jet-cooked with cornstarch in a series of laboratory experiments to investigate the viscoelastic properties of gum-modified starch solutions. The Lesquerella gum was combined with cornstarch at 1, 5, and 10%

R. A. Holser; C. J. Carriere; J. S. Park; T. P. Abbott

2000-01-01

142

The Effects of Chewing Gum on Gastric Content Prior to Induction of General Anesthesia  

Microsoft Academic Search

To study the effects on gastric content and subjective well being of chewing gum in the immediate preopera- tive period, 60 female nonsmokers were randomized to use regular, sugar-free chewing gum preoperatively or to continue the overnight fast. In a similar fashion 44 habitual smokers were randomized to use nicotine gum 2 mg or not. Nonsmokers using chewing gum had

Eldar Soreide; Helge Holst-Larsen; Terje Veel; Petter A. Steen

1995-01-01

143

Role of glucose in chewing gum-related facilitation of cognitive function  

Microsoft Academic Search

This study tests the hypothesis that chewing gum leads to cognitive benefits through improved delivery of glucose to the brain, by comparing the cognitive performance effects of gum and glucose administered separately and together. Participants completed a battery of cognitive tests in a fully related 2×2 design, where one factor was Chewing Gum (gum vs. mint sweet) and the other

Richard Stephens; Richard J. Tunney

2004-01-01

144

Which smokers report most relief from craving when using nicotine chewing gum?  

Microsoft Academic Search

Seventy-seven smoker clinic clients who managed at least 2 weeks of smoking abstinence while chewing 2 mg nicotine gum reported the degree to which the gum reduced their craving for cigarettes, their daily gum consumption and the extent of urges to smoke despite the gum. Greatest relief from craving by the gum was reported by smokers with higher pre-abstinence expired-air

R. J. West; P. Hajek; M. Belcher

1986-01-01

145

Emulsification properties of a novel hydrocolloid (Angum gum) for d-limonene droplets compared with Arabic gum.  

PubMed

In this study, the emulsification properties of a native biopolymer namely Angum gum (Ang) for use as a food flavor encapsulant in spray drying encapsulation was investigated and the results were compared with Arabic gum (Arg) stabilized emulsions. After gum extraction, gum dispersions with maltodextrin were prepared in water (in 1-5% concentrations) and emulsified with 5 and 10% d-limonene using high pressure homogenization. Statistical analysis of emulsion droplet size data revealed a significant difference between flavor level, gum type and droplet size at ?=0.05. The results showed that increasing the Arg level leads to a decrease in emulsion droplet size, while increasing Ang content results in bigger droplet sizes. However, no significant differences were observed in droplet size. Also, droplet size data revealed that Ang-emulsified droplets at 2% gum and 5% flavor level had the lowest d32, d43 and the highest specific surface area by high-pressure homogenizer which could be mentioned as the optimum level of this native gum. PMID:23817096

Jafari, Seid Mahdi; Beheshti, Peyman; Assadpour, Elham

2013-10-01

146

Nicotine chewing gum (2 mg, 4 mg) and cigarette smoking: comparative effects upon vigilance and heart rate  

Microsoft Academic Search

Sixteen male smokers, abstinent the morning before testing, were assessed under four conditions: placebo chewing gum, 2 mg nicotine chewing gum, 4 mg nicotine gum, and cigarette smoking. Placebo gum was administered in the cigarette condition, while sham smoking occurred in the gum conditions. Pre-drug administration and post-drug difference scores were calculated for each assessment measure: rapid visual information processing

A. C. Parrott; G. Winder

1989-01-01

147

Effect of Chewing Xylitol Chewing Gum on Salivary Flow Rate and the Acidogenic Potential of Dental Plaque  

Microsoft Academic Search

Ten adults participated in the study which consisted of four experimental periods each lasting 2 weeks, during each of which subjects were assigned to one of four gum-chewing regimens: no gum, sucrose gum, sorbitol gum and xylitol gum. At the start and end of each test period unstimulated and stimulated salivary flow rates were determined. At the end of each

O. Aguirre-Zero; D. T. Zero; H. M. Proskin

1993-01-01

148

Equipment for drug release testing of medicated chewing gums.  

PubMed

An apparatus was specially designed and constructed for release testing of medicated chewing gums. The adjustable instrumental settings such as temperature, chewing frequency, chewing time, volume of test medium, distance between the jaws and twisting angle increased the versatility of the apparatus. Selection of the test medium was also an important parameter. Each sample was kneaded mechanically in separate test chambers and the drug release was followed by sampling and HPLC analysis. Different gum formulations were tested and the obtained results demonstrated satisfactory release curves for a variety of formulations and active ingredients. The tested gum formulations comprised nicotine, meclizine, dimenhydrinate and xylitol. The apparatus proved to be suitable in product control of commercial batches but also a useful tool in the research and development of medicated gum formulations. PMID:10766358

Kvist, L C; Andersson, S B; Berglund, J; Wennergren, B; Fors, S M

2000-04-01

149

The Antibacterial Effect of CMCTS-Containing Chewing Gum  

Microsoft Academic Search

ObjectiveThis paper was designed to confirm the efficacy of chewing carboxymethyl chitosan(CMCTS)-containing gum in suppressing the growth of oral bacteria when compared to a CMCTS-containing mouth rinse.

Dagang Miao; Dan Blom; Hongmei Zhao; Xuefei Luan; Tongzhi Chen; Xiaohui Wu; Ning Song

2009-01-01

150

Reproductive Biology of Some Gum-Producing Indian Desert Plants  

Microsoft Academic Search

\\u000a This chapter covers the reproductive biology of Acacia senegal, Butea monosperma, Boswellia serrata, Commiphora wightii and Sterculia urens – important gum and gum-resin yielding tree species that grow in the deserts and dry deciduous forests of India. These species\\u000a have been overexploited and there is a need for conservation of their germplasm to ensure their availability on a sustainable\\u000a basis.

Rajesh Tandon; K. R. Shivanna; H. Y. Mohan Ram

151

A Two-Year Clinical Trial of Sorbitol Chewing Gum  

Microsoft Academic Search

A clinical trial of sorbitol chewing gum was carried out in 540 children aged 7–11 years in a nonfluoride area. Subjects were assigned at random to one of two groups, a no chewing group and one which chewed gum twice daily. Mean caries increments over the 2-year study period were 4.6 new DF surfaces (SD = 4.8) for the sorbitol

R. L. Glass

1983-01-01

152

Nicotine chewing gum as a substitute for smoking  

Microsoft Academic Search

The capacity of nicotine-containing chewing gum to produce plasma nicotine levels comparable to heavy cigarette smoking was tested in 21 subjects. On a fixed schedule of one piece of gum (4 mg nicotine) per hour, the average peak plasma nicotine concentration was 175-7 nmol\\/l (28-5 ng\\/ml) compared to 189-3 nmol\\/l (30-7 ng\\/ml) obtained from normal ad libitum smoking. Unpleasant side

M A Russell; S R Sutton; C Feyerabend; P V Cole; Y Saloojee

1977-01-01

153

Randomised controlled trial of nicotine chewing-gum  

Microsoft Academic Search

The effectiveness of 2 mg nicotine chewing-gum as an aid to stopping smoking was compared with a placebo containing 1 mg nicotine, but unbuffered, in a double-blind randomised trial. Of 58 subjects given the active gum, 27 (47%) were not smoking at one-year follow-up compared with 12 (21%) of the 58 subjects treated with placebo (p less than 0.025). By

M J Jarvis; M Raw; M A Russell; C Feyerabend

1982-01-01

154

Design, formulation and evaluation of green tea chewing gum  

PubMed Central

Background: The main purpose of this study is to design, formulate and evaluate the green tea gums with a suitable taste and quality in order to produce an anti-oxidant chewing gum. Materials and Methods: Fresh green tea leaves obtained from Northern Iran for extraction. Maceration is the extraction method that is used in this study. The contents of caffeine, catechin and flavonoids of the hydro alcoholic extract were measured. Various formulations of the 120 mg green tea extract chewing gums with different sweeteners, flavoring agents and various gum bases were prepared afterward release pattern, content uniformity, organoleptic results and other properties were characterized. Results: The contents of caffeine, catechin and flavonoid of the hydro alcoholic extraction were 207.32 mg/g, 130.00 mg/g and 200.82 mg/g, respectively. Release pattern of green tea chewing gum with different gum base ratios and various sweeteners in phosphate buffer were prepared. A total of 60 persons who were 20-30 years of age, participated in our panel test for organoleptic properties such as taste, stiffness, stickiness, etc., Acceptable gum was the one with the same ratio of the used rubber bases. Cinnamon selected as the preferred taste by volunteers. Combination of aspartame, sugar and maltitol has appropriate taste. The effect of various sweetener on release pattern was negligible, on the other hand rubber bases ratio variation, changed the release pattern obviously. Conclusion: The green tea chewing gum with sugar, maltitol and aspartame sweeteners and cinnamon flavor, using the same rubber bases ratio may be a desirable antioxidant product. PMID:25161989

Aslani, Abolfazl; Ghannadi, Alireza; Khalafi, Zeinab

2014-01-01

155

Chewing gum and impasse-induced self-reported stress.  

PubMed

An insoluble anagram task [Zellner, D., Loaiza, S., Gonzalez, Z., Pita, J., Morales, J., Pecora, D., et al. (2006). Food selection changes under stress. Physiology and Behaviour, 87, 789-793] was used to investigate the proposition that chewing gum reduces self-rated stress [Scholey, A., Haskell, C., Robertson, B., Kennedy, D., Milne, A., & Wetherell, M. (2009). Chewing gum alleviates negative mood and reduces cortisol during acute laboratory psychological stress. Physiology and Behaviour, 97, 304-312]. Using a between-participants design, 40 participants performed an insoluble anagram task followed by a soluble anagram task. These tasks were performed with or without chewing gum. Self-rated measures were taken at baseline, post-stressor, and post-recovery task. The insoluble anagram task was found to amplify stress in terms of increases in self-rated stress and reductions in both self-rated calmness and contentedness. However, chewing gum was found not to mediate the level of stress experienced. Furthermore, chewing gum did not result in superior performance on the soluble anagram task. The present study fails to generalise the findings of Scholey et al. to an impasse-induced stress that has social components. The explanation for the discrepancy with Scholey et al. is unclear; however, it is suggested that the impossibility of the insoluble anagram task may negate any secondary stress reducing benefits arising from chewing gum-induced task improvement. PMID:19619595

Torney, Laura K; Johnson, Andrew J; Miles, Christopher

2009-12-01

156

Rheological properties of grouts with viscosity modifying agents as diutan gum and welan gum incorporating pulverised fly ash  

Microsoft Academic Search

This investigation was undertaken to evaluate the influence of the dosage of the second generation of viscosity modifying agent (diutan gum) on fluidity and rheological parameters of cement-based materials grout compared to welan gum. All grouts were made with 0.40 water-to-binder ratio (W\\/B). The fresh properties of control grouts made without any viscosity modifying agent (VMA) and with superplasticizer (SP)

Mohammed Sonebi

2006-01-01

157

The impact of chewing gum resistance on immediate free recall.  

PubMed

Although the facilitative effects of chewing gum on free recall have proved contentious (e.g., Tucha, Mecklinger, Maier, Hammerl, & Lange, 2004; Wilkinson, Scholey, & Wesnes, 2002), there are strong physiological grounds, for example, increased cerebral activity and blood flow following the act of mastication, to suppose facilitation. The present study manipulated resistance to mastication, that is, chewing four pellets versus one pellet of gum, with the assumption that increased resistance will accentuate cerebral activity and blood flow. Additionally, chewing rate was recorded for all participants. In a within-participants design, participants performed a series of immediate free recall tasks while chewing gum at learning (one or four pellets) and recall (one or four pellets). Increased chewing resistance was not associated with increased memory performance, despite consistent chewing rates for both the one and four pellet conditions at both learning and recall. However, a pattern of recall consistent with context-dependent memory was observed. Here, participants who chewed the equivalent number of gum pellets at both learning and recall experienced significantly superior word recall compared to those conditions where the number of gum pellets differed. PMID:23848385

Rickman, Sarah; Johnson, Andrew; Miles, Christopher

2013-08-01

158

STUDIES ON SOME PHYSICOCHEMICAL PROPERTIES OF LEUCAENA LEUCOCEPHALA BARK GUM  

PubMed Central

Gum exudates from Leucaena Leucocephala (Family: Fabaceae) plants grown all over India were investigated for its physicochemical properties such as pH, swelling capacity and viscosities at different temperatures using standard methods. Leucaena Leucocephala bark gum appeared to be colorless to reddish brown translucent tears. 5 % w/v mucilage has pH of 7.5 at 28°C. The gum is slightly soluble in water and practically insoluble in ethanol, acetone and chloroform. It swells to about 5 times its original weight in water. A 5 %w/ v mucilage concentration gave a viscosity value which was unaffected at temperature ranges (28-40°C). At concentrations of 2 and 5 %w/v, the gum exhibited pseudo plastic flow pattern while at 10 %w/v concentration the flow behaviour was thixotropic. The results indicate that the swelling ability of Leucaena Leucocephala (LL) bark gum may provide potentials for its use as a disintegrant in tablet formulation, as a hydro gel in modified release dosage forms and the rheological flow properties may also provide potentials for its use as suspending and emulsifying agents owing to its pseudo plastic and thixotropic flow patterns. PMID:22247853

Pendyala, Vijetha; Baburao, Chandu; Chandrasekhar, K.B

2010-01-01

159

In situ Remineralization of Subsurface Enamel Lesion after the Use of a Fluoride Chewing Gum  

Microsoft Academic Search

In situ remineralization of early enamel lesions by a fluoride chewing gum was studied. Human enamel specimens with subsurface lesions were mounted in removable lower appliances for 6 adults. Subjects used a F-free dentifrice 3 ×\\/day and chewed five sticks\\/day for the F gum group (0.1 mg F\\/stick) or five sticks of sugarless gum. No gum was chewed for controls.

W. J. Lamb; R. E. Corpron; F. G. More; E. D. Beltran; D. S. Strachan; C. J. Kowalski

1993-01-01

160

Effect of Sorbitol, Xylitol, and Xylitol\\/Sorbitol Chewing Gums on Dental Plaque  

Microsoft Academic Search

The effect of sorbitol (SOR), xylitol (XYL), and the mixture XYL\\/SOR in chewing gums on dental plaque was studied in three groups of 7 adults (mean age 22.5 years). A fourth group of habitual users of sucrose-containing gums was used as a control. The study involved a 2-week, no-gum period followed by the use of the polyol gums for 2

E. Söderling; K. K. Mäkinen; C.-Y. Chen; W. Loesche; P.-L. Mäkinen

1989-01-01

161

Chewing-Gum Flavor Affects Measures of Global Complexity of Multichannel EEG  

Microsoft Academic Search

Global complexity of spontaneous brain electric activity was studied before and after chewing gum without flavor and with 2 different flavors. One-minute, 19-channel, eyes-closed electroencephalograms (EEG) were recorded from 20 healthy males before and after using 3 types of chewing gum: regular gum containing sugar and aromatic additives, gum containing 200 mg theanine (a constituent of Japanese green tea), and

T. Yagyu; J. Wackermann; T. Kinoshita; T. Hirota; K. Kochi; I. Kondakor; T. Koenig; D. Lehmann

1997-01-01

162

Toxicologic evaluation of modified gum acacia: Mutagenicity, acute and subchronic toxicity  

Microsoft Academic Search

Modified gum acacia, produced from acacia gum by a process analogous to the production of modified food starch, was tested for mutagenicity in the microbial reverse mutation assay. The assay employed a wide range of dose levels, both with and without metabolic activation. Test results gave no indication that modified gum acacia possessed any mutagenic potential. The acute oral toxicity

D. Schmitt; N. Tran; S. Riefler; J. Jacoby; D. Merkel; P. Marone; N. Naouli

2008-01-01

163

Effects of Chewing Different Flavored Gums on Salivary Flow Rate and pH.  

PubMed

Chewing gum increases salivary flow rate (SFR) and pH, but differences in preferences of gum flavor may influence SFR and pH. The aim of this paper was to assess the effect of five different flavors of sucrose-free chewing gum on the salivary flow rate and pH in healthy dental students in Isfahan, Iran. Fifteen (7 men and 8 women) healthy dental student volunteers collected unstimulated saliva and then chewed one of five flavored gums for 6?min. The whole saliva was collected and assessed for 6 consecutive days. After unstimulated saliva was collected, stimulated saliva was collected at interval of 0-1, 1-3, and 3-6 minutes after the start of different flavored chewing gums. The SFR and salivary pH were measured. The SFR increased in all five flavored gums at 1, 3, and 6 minutes after start of chewing gums (P < 0.001). The flow rate of all products reached peak in the 1st minute of stimulation, except spearmint-flavored gums which reached peak in the 6th minute. In the 1st minute, the strawberry-flavored gums showed the highest SFR. During 1-3 minutes, strawberry- and apple-flavored gums showed higher SFR, respectively. Only the spearmint- and cinnamon-flavored gum significantly increased salivary pH. Gum flavored can affect the SFR and pH and special flavors can be advised for different individuals according to their oral conditions. PMID:22505903

Karami Nogourani, Maryam; Janghorbani, Mohsen; Kowsari Isfahan, Raha; Hosseini Beheshti, Mozhgan

2012-01-01

164

Factors affecting the emulsifying and rheological properties of gum acacia in beverage emulsions  

Microsoft Academic Search

Gum acacia, a natural hydrocolloid, is extensively used as an emulsifier\\/stabilizer in beverage emulsions. Factors that may affect emulsion formation, emulsion stability and viscosity of the emulsion concentrate were studied to assess their significance, including proximal composition of the gum (protein content and mineral content), gum processing prior to emulsion preparation (pasteurization and demineralization), and pH of the dilute emulsion.

R. A Buffo; G. A Reineccius; G. W Oehlert

2001-01-01

165

Xylitol Chewing Gums and Caries Rates: A 40-month Cohort Study  

Microsoft Academic Search

Dental caries is a pandemic infectious disease which can affect the quality of life and consumes considerable health care resources. The chewing of xylitol, sorbitol, and even sugar gum has been suggested to reduce caries rates. No clinical study has simultaneously investigated the effectiveness of these gums when compared with a group receiving no chewing gum. A 40-month double-blind cohort

K. K. Makinen; C. A. Bennett; P. P. Hujoel; P. J. Isokangas; K. P. Isotupa; H. R. Pape; PL Makinen

1995-01-01

166

Use of dye as tracer of drug release from medicated chewing gums  

Microsoft Academic Search

The evaluation of the potential use of a dye as indicator of in vivo drug release from a medicated chewing gum is described. The device is a three-layer tablet obtained by direct compression consisting of a gum core and two external protective soluble layers to prevent gum adhesion to the punches of the tableting machine. The active ingredient and a

Evelyn Ochoa; Lauretta Maggi; Stefania Conti; Ubaldo Conte; Guy Vergnault; Pascal Grenier

2008-01-01

167

FORMULATION OF MEDICATED CHEWING GUM OF ONDANSETRON HYDROCHLORIDE AND ITS PHARMACOKINETIC EVALUATIONS  

Microsoft Academic Search

An attempt has been made to formulate new chewing gum device for ondansetron hydrochloride in the form of tablet. The new drug delivery system was obtained, at room temperature, by direct compression using conventional pharmaceutical equipment. The resulting chewing gum tablets comprise a gum core combined with fillers, antioxidants, coloring agent and plasticizers, which provide smooth appearance and flexibility during

UPENDRA NAGAICH; VANDANA CHAUDHARY; ROOPA KARKI; AKASH YADAV; B. M. Reddy

2010-01-01

168

Molecular structures of gum exudates from Hakea species.  

PubMed

Partial acid-hydrolysis of the gum exudates from Hakea sericea and H. gibbosa yields L-arabinose, D-galactose, D-xylose, D-mannose, D-glucuronic acid, the aldobiouronic acid GlcA (beta 1,2)Man, and a dimer of this acid alpha-linked from D-Man to O-4 of GlcA. Methylation analysis showed the modes of linkage of the sugar units to be typical of those present in plant polysaccharide exudates of the arabinogalactan type, while partial acid hydrolysis and Smith degradations established the position of linkage of the peripheral sugar assemblies at O-3 of D-Man in the interior core. Some minor differences were noted between the molecular structures of the gums from these two species of Hakea, the Gal:Ara ratio being higher for H. sericea gum. PMID:7764147

Eagles, P F; Stephen, A M; Churms, S C

1993-10-01

169

Hybrid modeling of xanthan gum bioproduction in batch bioreactor.  

PubMed

This work is focused on hybrid modeling of xanthan gum bioproduction process by Xanthomonas campestris pv. mangiferaeindicae. Experiments were carried out to evaluate the effects of stirred speed and superficial gas velocity on the kinetics of cell growth, lactose consumption and xanthan gum production in a batch bioreactor using cheese whey as substrate. A hybrid model was employed to simulate the bio-process making use of an artificial neural network (ANN) as a kinetic parameter estimator for the phenomenological model. The hybrid modeling of the process provided a satisfactory fitting quality of the experimental data, since this approach makes possible the incorporation of the effects of operational variables on model parameters. The applicability of the validated model was investigated, using the model as a process simulator to evaluate the effects of initial cell and lactose concentration in the xanthan gum production. PMID:21553014

Zabot, Giovani L; Mecca, Jaqueline; Mesomo, Michele; Silva, Marceli F; Prá, Valéria Dal; de Oliveira, Débora; Oliveira, J Vladimir; Castilhos, Fernanda; Treichel, Helen; Mazutti, Marcio A

2011-10-01

170

Preparation and characterization of carboxymethyl guar gum nanoparticles.  

PubMed

Carboxymethyl guar gum nanoparticles (CMGGNPs) were synthesized by nanoprecipitation and sonication method. This method was used for the first time for the synthesis of carboxymethyl guar gum nanoparticles. It was found that the formation of nanoparticles might depend upon the sonication time, solvent, and stirring time. Nanoparticles were characterized by SEM, TEM, XRD and FTIR. The sizes of the particles in suspension have been found in the range 12-30nm. It was concluded that such type of nanoparticles may be used in pharmaceutical and drug delivery. PMID:24832982

Gupta, Anek Pal; Verma, Devendra Kumar

2014-07-01

171

Improving encapsulation efficiency and stability of water-in-oil-in-water emulsions using a modified gum arabic (Acacia (sen) SUPER GUM™)  

Microsoft Academic Search

A matured gum arabic, (Acacia (sen) SUPER GUM™) was investigated as an emulsifier to aid in the stabilisation of water-in-oil-in-water (W\\/O\\/W) emulsions. Emulsions were characterised by phase separation, confocal microscopy, droplet sizing, and encapsulation efficiencies (EE). Initial results showed that some precipitates were observed when SUPER GUM™ was dissolved in a 0.1M sodium phosphate buffer and this necessitated the preparation

Jiahong Su; John Flanagan; Harjinder Singh

2008-01-01

172

Effects and after-effects of chewing gum on vigilance, heart rate, EEG and mood.  

PubMed

Research has shown that chewing gum improves attention, although the mechanism for this effect remains unclear. This study investigated the effects and after-effects of chewing gum on vigilance, mood, heart rate and EEG. Participants completed a vigilance task four times; at baseline, with or without chewing gum, and twice post-chewing. EEG alpha and beta power at left frontal and temporal lobes, subjective mood and heart rate were assessed. Chewing gum shortened reaction time and increased the rate of hits, although hits fell during the second post-chewing task. Chewing gum heightened heart rate, but only during chewing. Gum also increased beta power at F7 and T3 immediately post-chewing, but not following the post-chewing tasks. The findings show that chewing gum affects several different indicators of alertness. PMID:24857722

Allen, Andrew P; Jacob, Tim J C; Smith, Andrew P

2014-06-22

173

Guaranteed uncertainty management (GUM) for sensor provisioning in missile defense  

E-print Network

Guaranteed uncertainty management (GUM) for sensor provisioning in missile defense Alfred O Hero or discriminating between N targets. It is a central problem in missile defense radar systems where the number was sensor management for engagement planning in missile defense. The guaranteed un- certainty management

Hero, Alfred O.

174

UTILIZATION OF OKRA GUM FOR TREATMENT OF TANNERY EFFLUENT  

Microsoft Academic Search

Several natural polymeric flocculants are used for water purification. Natural polymers, mainly polysaccharides, by virtue of being biodegradable, non-toxic, shear stable and easily available, are becoming popular in domestic and industrial effluent treatment. Okra gum obtained from seedpods of Hibiscus esculentus is an anionic polysaccharide. It is used as flocculant for removal of solid wastes from tannery effluent in this

M. Agarwal; S. Rajani; A. Mishra; J. S. P. Rai

2003-01-01

175

Investigation of Transport Properties of a New Biomaterials - GUM Mangosteen  

NASA Astrophysics Data System (ADS)

Biomaterial has occupied leading position in material science for various scientific and technological applications. This present work is carried out over a natural gum extracted from raw fruit of Mangosteen, an east Indian tree (Gercinia Mangostana) following extraction and purification process. Solid specimen of the said gum is developed following sol-gel like process. AC and DC electrical analysis on the dried solid specimen of the gum were carried out and showed high electrical conduction with ? ~ 1 E-03 S/cm, of which ionic and electronic contributions are 70% and 30% respectively. Analysis shows that origin of high electrical conductivity is due to presence of substantial amount of organic acid unit in its polysaccharide background. In fact the observed ? is about 1000 times of that observed in gum Arabica. Optical absorption of this new bio- materials are also studied using UV-VIS analysis. The results show its high absorption co-efficient in UV and blue part of analysed range. A complete electrical characterization of the material have been made. It has also been observed that the electronic conduction can be enhanced to 70% of the total electrical conductivity by forming complex with Iodine and organic (Citric) acid from Lemon fruit. This high potential material is being studied for development of electronic device application.

Pradhan, Sourav S.; Sarkar, A.

2006-06-01

176

The effect of chewing gum on tobacco withdrawal  

Microsoft Academic Search

When smokers are in situations where smoking is prohibited, chewing gum is believed to reduce cravings to smoke. However, there is little scientific evidence to support this widely held assumption. The present study assessed craving for a cigarette and nicotine withdrawal in 20 dependent cigarette smokers under one of two conditions. All subjects smoked an initial cigarette upon arrival to

Lee M. Cohen; Frank L. Collins; Dana M. Britt

1997-01-01

177

Equipment for drug release testing of medicated chewing gums  

Microsoft Academic Search

An apparatus was specially designed and constructed for release testing of medicated chewing gums. The adjustable instrumental settings such as temperature, chewing frequency, chewing time, volume of test medium, distance between the jaws and twisting angle increased the versatility of the apparatus. Selection of the test medium was also an important parameter. Each sample was kneaded mechanically in separate test

L. Catharina Kvist; Sven-Börje Andersson; Johan Berglund; Bo Wennergren; Susan M Fors

2000-01-01

178

BRIEF REPORT THE EFFECT OF CHEWING GUM ON TOBACCO WITHDRAWAL  

Microsoft Academic Search

When smokers are in situations where smoking is prohibited, chewing gum is be- lieved to reduce cravings to smoke. However, there is little scientific evidence to support this widely held assumption. The present study assessed craving for a cigarette and nicotine with- drawal in 20 dependent cigarette smokers under one of two conditions. All subjects smoked an initial cigarette upon

LEE M. COHEN; FRANK L. COLLINS; DANA M. BRITT

179

In vitro tooth whitening effect of two medicated chewing gums compared to a whitening gum and saliva  

Microsoft Academic Search

BACKGROUND: Extrinsic staining of teeth may result from the deposition of a variety of pigments into or onto the tooth surface, which originate mainly from diet or from tobacco use. More recently, clinical studies have demonstrated the efficacy of some chewing gums in removing extrinsic tooth staining. The aim of this study was to assess the effectiveness of two nicotine

Michael Moore; Nathalie Hasler-Nguyen; Geoffrey Saroea

2008-01-01

180

Use of hydrophilic natural gums in formulation of sustained-release matrix tablets of tramadol hydrochloride.  

PubMed

The objective of this work was to develop matrix sustained-release tablets of highly water-soluble tramadol HCl using natural gums (xanthan [X gum] and guar [G gum]) as cost-effective, nontoxic, easily available, and suitable hydrophilic matrix systems compared with the extensively investigated hydrophilic matrices (ie, hydroxypropyl methylcellulose [HPMC]/carboxymethyl cellulose [CMC] with respect to in vitro drug release rate) and hydration rate of the polymers. Matrix tablets of tramadol (dose 100 mg) were produced by direct compression method. Different ratios of 100:0, 80:20, 60:40, 20:80, 0:100 of G gum (or X):HPMC, X gum:G gum, and triple mixture of these polymers (G gum, X gum, HPMC) were applied. After evaluation of physical characteristics of tablets, the dissolution test was performed in the phosphate buffer media (pH 7.4) up to 8 hours. Tablets with only X had the highest mean dissolution time (MDT), the least dissolution efficiency (DE(8)%), and released the drug following a zero-order model via swelling, diffusion, and erosion mechanisms. Guar gum alone could not efficiently control the drug release, while X and all combinations of natural gums with HPMC could retard tramadol HCl release. However, according to the similarity factor (f(2) ), pure HPMC and H(8)G(2) were the most similar formulations to Topalgic-LP as the reference standard. PMID:16584155

Varshosaz, Jaleh; Tavakoli, Naser; Kheirolahi, Fatemeh

2006-01-01

181

Socio-economic aspects of Gum Arabic production in Dalanj area, South Korodofan, Sudan.  

PubMed

Acacia senegal (locally: Hashab tree) is one of the most important tree species in Sudan as it considers the main Gum Arabic producing tree. The objective of this study is to investigate the socio-economic aspects of gum Arabic production and to assess contribution of gum Arabic to sustainable livelihood of local people in Dalanj Locality, South Kordofan State-Sudan. Social survey was carried out by using structured questionnaire for 80 respondents (gum producers) on random sample basis in eight villages, 10 respondents from each village. Issues pertaining to socio-economic factors affecting gum Arabic production and contribution of gum Arabic to sustainable livelihood of local people, in Dalanj Locality, were assessed. Results of the study revealed that expansion of agriculture lands at the expense of hashab trees, fires and illegal felling are the most important factors constraining gum production in the area. The results also indicated that agriculture is the main source of income and gum Arabic is a supplementary source of income. The importance of gum Arabic becomes apparent during (off farm season) the period between crops harvest and the preparation of the next agricultural season. Establishment of producers' associations and provision of loans to producers are highly recommended to ensure sustainability of gum production. PMID:24511757

Koli, A O; Eltayeb, A M; Sanjak, E M; Mohammed, M H

2013-11-01

182

Gum Containing Calcium Fluoride Reinforces Enamel Subsurface Lesions in situ  

Microsoft Academic Search

The aim of this study was to assess the effect of chewing gum containing phosphoryl oligosaccharides of calcium (POs-Ca) and a low concentration of fluoride (F) on the hardness of enamel subsurface lesions, utilizing a double-blind, randomized, and controlled in situ model. Fifteen individuals wore removable lingual appliances with 3 bovine-enamel insets containing subsurface demineralized lesions. Three times a day

Y. Kitasako; A. Sadr; H. Hamba; M. Ikeda; J. Tagami

2012-01-01

183

Use of hydrophilic natural gums in formulation of sustained-release matrix tablets of tramadol hydrochloride  

Microsoft Academic Search

The objective of this work was to develop matrix sustained-release tablets of highly water-soluble tramadol HCl using natural\\u000a gums (xanthan [X gum] and guar [G gum]) as cost-effective, nontoxic, easily available, and suitable hydrophilic matrix systems\\u000a compared with the extensively investigated hydrophilic matrices (ie, hydroxypropyl methylcellulose [HPMC]\\/carboxymethyl cellulose\\u000a [CMC] with respect to in vitro drug release rate) and hydration rate

Jaleh Varshosaz; Naser Tavakoli; Fatemeh Kheirolahi

2006-01-01

184

Utilization of laboratory-produced xanthan gum in the manufacture of yogurt and soy yogurt  

Microsoft Academic Search

The effect of laboratory-produced xanthan gum and mixtures of it with other gums at different concentrations on the chemical, microbiological, rheological, micro-structural and sensory properties of yogurt and soy yogurt were studied. The addition of xanthan gum or its mixtures had no marked effect on pH-values, contents of total solids or the changes of lactic acid bacterial counts of yogurt

E. M. El-Sayed; I. A. Abd El-Gawad; H. A. Murad; S. H. Salah

2002-01-01

185

Gum kondagogu-g-poly (acrylamide): Microwave-assisted synthesis, characterisation and release behaviour  

Microsoft Academic Search

Microwave-assisted grafting of gum kondagogu onto poly (acrylamide) was carried out employing two-level, four-factor full factorial experimental design. Gum kondagogu-g-poly(acrylamide) was characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction and scanning electron microscopy. Microwave power, microwave exposure time and the concentration of ammonium persulfate had significant synergistic effect on grafting efficiency, while the concentration of gum kondagogu

Swati Malik; Munish Ahuja

2011-01-01

186

Effect of gel-forming gums on the intestinal unstirred layer and sugar transport in vitro  

Microsoft Academic Search

The effect of two gel-forming polysaccharide gums, guar gum and Na-carboxymethyl-cellulose (CMC), on glucose transport in vitro was investigated using everted sacs of rat jejunum. The gums were added to the mucosal bathing media to give apparent viscosities in the range of 1-110 Pascal seconds X 10(-3), mPa.s(cP). Serosal glucose transport fell steeply by about 60% as the viscosities of

I T Johnson; J M Gee

1981-01-01

187

Optimization of xanthan gum production by Xanthomonas campestris grown in molasses  

Microsoft Academic Search

Xanthan gum production by Xanthomonas campestris ATCC 1395 using sugar beet molasses as carbon source was studied. The pre-treatment of sugar beet molasses and the supplementation of the medium were investigated in order to improve xanthan gum production. Addition of K2HPO4 to the medium had a significant positive effect on both xanthan gum and biomass production. The medium was subsequently

Stavros Kalogiannis; Gesthimani Iakovidou; Maria Liakopoulou-Kyriakides; Dimitrios A Kyriakidis; George N Skaracis

2003-01-01

188

Natural gum and resin bearing species of Ethiopia and their potential applications  

Microsoft Academic Search

Ethiopia is one of the countries well endowed with various species of Acacia, Boswellia and Commiphora that are known to produce gum arabic, frankincense and myrrh, respectively. Over 60 gum and resin bearing species are found in the country. The total area of oleo-gum resin bearing woodlands cover about 2.9 million ha of land in the country, with over 300,000

W. Tadesse; G. Desalegn; R. Alia

189

The short-term effect of nicotine chewing gum in patients with parkinson's disease  

Microsoft Academic Search

Because of the inverse association of cigarette smoking with the risk of Parkinson's disease, we performed a short-term, double-blind, randomized controlled trial of nicotine polacrilex resin gum in patients with this disease. Forty-eight subjects were randomly assigned to chew either nicotine gum or placebo gum three times at 2-h intervals, with evaluation of symptoms before and after the trial. The

Paula Clemens; John A. Baron; David Coffey; Alexander Reeves

1995-01-01

190

Protective effect of arabic gum against acetaminophen-induced hepatotoxicity in mice  

Microsoft Academic Search

Overdose of acetaminophen, a widely used analgesic drug, can result in severe hepatotoxicity and is often fatal. This study was undertaken to examine the effects of arabic gum (AG), which is commonly used in processed foods, on acetaminophen-induced hepatotoxicity in mice. Mice were given arabic gum orally (100gl?1) 5 days before a hepatotoxic dose of acetaminophen (500mgkg?1) intraperitoneally. Arabic gum

Ayman M Gamal el-din; Adel M. Mostafa; Othman A. Al-Shabanah; Abdullah M. Al-Bekairi; Mahmoud N. Nagi

2003-01-01

191

Cardiovascular effects of nicotine chewing gum in healthy non-smokers  

Microsoft Academic Search

Nicotine chewing gum (Nicorette® 4 mg) and an identical placebo gum were administered on different days, in a double-blind cross over fashion, to 4 men, aged 25–52 years, and 4 women, aged 21–49 years, all healthy non-smokers. The subjects chewed the gum for 30 min and heart rate, blood pressure, electrocardiogram, finger tip temperature, calf and hand blood flow and

G. Nyberg; V. Panfilov; R. Sivertsson; L. Wilhelmsen

1982-01-01

192

Insulin chewing gum: Need of the day for diabetic patients  

PubMed Central

Chewing gum is an excellent drug delivery system for self medication as it is convenient, can be administered discreetly without water and offers the removal of ‘needle fear’ for the patients. As it releases insulin orally, it helps in tackling of the deprivation of insulin by digestive enzyme without adding digestive enzyme inhibitor. This can be done by binding of vitamin B12 and insulin. The vitamin B12 is protected with haptocorrin which is a salivary protein. Another chemical pathway takes over to help vitamin B12 pass into the bloodstream as haptocorrin reaches the intestines. The binding of vitamin B12 and insulin molecules makes the insulin to be protected on this supply chain. The insulin could ride all the way into the bloodstream, where it is released to do its work. By stimulating the brain, chewing gum also increases the releases of insulin. Finding simpler ways to deliver insulin into the blood stream is one important avenue for tackling the diabetes epidemic that is sweeping the developed world. The conditions in gastrointestinal tract may damage the body's protecting and absorbing mechanisms for the valuable molecules. Chewing gum would be a better delivery method in humans. PMID:23071934

Mateti, Uday Venkat; Adla, Nagesh; Rajakannan, Thiyagu; Valakkathala, Rajesh

2011-01-01

193

Recovery, chemical and rheological characterization of gum from Assyrian pulm.  

PubMed

The extraction of gum from Assyrian pulm fruit (APH) was performed by microwave-assisted extraction technique. A Box-Behnken design (BBD) was applied to evaluate the effects of three independent variables (power of microwave (X1: 50-350W), extraction time (X2: 20-90min), and extraction temperature (X3: 50-90°C)) on the extraction yield of APH. The effect of temperature and concentration on flow behavior of gum solution was studied. The viscosity of 2% APH solution was 0.55Pas at a shear rate of 10s(-1) at 20°C. The viscosity of fully hydrated gum solutions decreased as temperature increase. It was found that increasing the temperature from 10 to 60°C causing the viscosity to decrease about 87% at shear rate 0.1s(-1) and 98% at shear rate 500s(-1). The correlation analysis of the mathematical-regression model indicated that quadratic polynomial model could be employed to optimize the microwave extraction of APH. The optimal conditions to obtain the highest extraction of APH (18.19±0.26%) were as follows: microwave power, 330W; extraction time, 80.67min and extraction temperature, 82°C. PMID:24661886

Samavati, Vahid; Skandari, Farshid

2014-06-01

194

Green synthesis of gold nanoparticles using gum polysaccharide of Cochlospermum religiosum (katira gum) and study of catalytic activity  

NASA Astrophysics Data System (ADS)

A green synthesis of gold nanoparticles (Au NPs) using aqueous solution of a hetero-polysaccharide, extracted from the gum of Cochlospermum religiosum (katira gum), has been demonstrated in this work. The hetero-polysaccharide plays the role of both reducing and stabilizing agent. The synthesized Au NPs were characterized by UV-vis spectroscopy, HR-TEM, XRD and FT-IR experiments. The surface plasmon resonance (SPR) band of UV-vis spectrum around 528 nm confirmed the formation of Au NPs. Transmission electron microscopic analysis showed an average size of Au NPs of 6.9 nm. The fcc crystalline nature of these particles was identified by XRD analysis and SAED pattern. These Au NPs also function as an efficient heterogeneous catalyst in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The reduction of 4-NP follows pseudo-first-order kinetics with rate constant 2.67×10-2 min-1.

Maity, Saikat; Kumar Sen, Ipsita; Sirajul Islam, Syed

2012-08-01

195

Synthesis and devolatilization of M-97 NVB silicone gum compounded into silica reinforced silicone base  

SciTech Connect

Silica reinforced silicon bases having 0.31 weight percent vinyl content were prepared by using a blend of low and high vinyl content devolatilized M-97 NVB silicone gum. The M-97 NVB is a custom dimethyl-, diphenyl-, methylvinylsiloxane gum. The silicon gum was devolatilized to evaluate the anticipated improved handling characteristics. Previous procured batches of M-97 NVB had not been devolatilized and difficult handling problems were encountered. The synthesis, devolatilization, and compound processes for the M-97 NVB silicone gum are discussed.

Schneider, J.W.

1986-06-01

196

Self-healing guar gum and guar gum-multiwalled carbon nanotubes nanocomposite gels prepared in an ionic liquid.  

PubMed

Guar gum is a galactomannan extracted from the seed of the leguminous shrub Cyamopsis tetragonoloba. It was found to form a soft viscoelastic gel in 1-butyl-3-methylimidazolium chloride, an ionic liquid at an optimized concentration of 10%w/v. A nanocomposite gel of the gum with enhanced strength could be prepared with 0.2%w/v of multiwalled carbon nanotubes (MWCNTs) in the ionic liquid. When the gels thus prepared were subjected to surface fractures or bisected completely, they found to self-heal at room temperature without any external interventions. The self-healing process could be repeated several times. These viscoelastic gel systems showed thixotropic nature and recovery of the storage modulus with time for several cycles was observed upon rheological investigations. The interaction took place between ionic liquid, guar gum and MWCNT was studied by SEM, TEM, FT-IR, powder XRD and rheometry. The results suggested that, upon standing at room temperature development of electrostatic interactions and the van der Waals interactions among the ionic liquid molecules facilitated the formation of reversible noncovalent bonds and eventually activated the self-healing in the gel systems through appropriate chain entanglements. PMID:23987443

Sharma, Mukesh; Mondal, Dibyendu; Mukesh, Chandrakant; Prasad, Kamalesh

2013-10-15

197

Magnetism  

NSDL National Science Digital Library

This webpage is part of the University Corporation for Atmospheric Research (UCAR) Windows to the Universe program. It describes the nature and configuration of magnetic fields, which are the result of moving electric charges, including how they cause magnetic objects to orient themselves along the direction of the magnetic force points, which are illustrated as lines. Magnetic field lines by convention point outwards at the north magnetic pole and inward at the south magnetic pole. The site features text, scientific illustrations and an animation. Text and vocabulary are selectable for the beginning, intermediate, or advanced reader.

Team, University C.

2007-12-12

198

78 FR 2251 - Xanthan Gum From Austria: Preliminary Determination of Sales at Less Than Fair Value and...  

Federal Register 2010, 2011, 2012, 2013

...with which xanthan gum may be blended include, but are not limited to, sugars, minerals, and salts. Xanthan gum is a polysaccharide produced by aerobic fermentation of Xanthomonas campestris. The chemical structure of the repeating pentasaccharide...

2013-01-10

199

78 FR 43143 - Xanthan Gum From the People's Republic of China: Amended Final Determination of Sales at Less...  

Federal Register 2010, 2011, 2012, 2013

...with which xanthan gum may be blended include, but are not limited to, sugars, minerals, and salts. Xanthan gum is a polysaccharide produced by aerobic fermentation of Xanthomonas campestris. The chemical structure of the repeating pentasaccharide...

2013-07-19

200

Physical and chemical stability of gum arabic-stabilized conjugated linoleic acid oil-in-water emulsions.  

PubMed

Oil-in-water (O/W) emulsions have been used as a delivery system to protect conjugated linoleic acid (CLA), a polyunsaturated fatty acid, from oxidation. Conventional gum arabic (GA) and two matured gum arabic samples (EM2 and EM10) were used as emulsifiers to prepare CLA-in-water emulsions. The emulsions have optimal physical and chemical stability at gum concentrations of 5% for all three gums. Emulsions with higher gum concentrations are more susceptible to lipid oxidation. This is attributed to reduced physical stability at higher gum concentrations because of the coalescence and depletion-induced flocculation of the emulsion droplets. The prooxidants iron and copper intrinsically contained in the gums could also contribute to this instability. Among the three gums, EM10 provides the most effective protection for CLA both physically and chemically, because of its superior interfacial properties over GA and EM2. PMID:23614832

Yao, Xiaolin; Xu, Qiong; Tian, Dazhi; Wang, Nana; Fang, Yapeng; Deng, Zhongyang; Phillips, Glyn O; Lu, Jiang

2013-05-15

201

Characterization and properties of Acacia senegal (L.) Willd. var. Senegal with enhanced properties (Acacia ( sen) SUPER GUM ™): Part 5. Factors affecting the emulsification of Acacia senegal and Acacia ( sen) SUPER GUM  

Microsoft Academic Search

Acacia senegal is the major gum arabic species used in commercial emulsification for the production of beverages and flavor concentrates. This paper examines the effect of gum concentration, molecular weight parameters and homogenization conditions on the droplet size and stability of emulsions prepared using a conventional commercial A. senegal product and a series of A. senegal test gums that were

Hiromitsu Aoki; Tsuyoshi Katayama; Takeshi Ogasawara; Yasushi Sasaki; Saphwan Al-Assaf; Glyn O. Phillips

2007-01-01

202

Enrichment of gum content from Lesquerella fendleri seed coat by air classification  

Microsoft Academic Search

Studies were conducted to increase the gum yield from Lesquerella fendleri seeds. The seeds were first fractured and the seed coat fraction isolated and defatted. The polysaccharide gum content of the defatted seed coat (28%) was concentrated by pin milling the seed coat at various speeds followed by air classification. A stepwise procedure involving pin milling at 14,000 rpm and

Y. Victor Wu; Thomas P. Abbott

1996-01-01

203

Gas chromatographic-mass spectrometric characterisation of plant gums in samples from painted works of art.  

PubMed

This paper presents an analytical GC-MS procedure to study the chemical composition of plant gums, determining aldoses and uronic acids in one step. The procedure is based on the silylation of aldoses and uronic acids, released from plant gums by microwave assisted hydrolysis, and previously converted into the corresponding diethyl-dithioacetals and diethyl-dithioacetal lactones. Using this method only one peak for each compound is obtained, thus providing simple and highly reproducible chromatograms. The analytical procedure was optimised using reference samples of raw plant gums (arabic, karaya, ghatti, guar, locust bean and tragacanth, cherry, plum and peach gums), commercial watercolours and paint layers prepared according to ancient recipes at the Opificio delle Pietre Dure of Florence (Italy). To identify gum media in samples of unknown composition, a decisional schema for the gum identification and the principal component analysis of the relative sugar percentage contents were employed. The procedure was used to study samples collected from wall paintings from Macedonian tombs (4th-3rd centuries bc) and from the Mycenaean "Palace of Nestor" (13th century bc) in Pylos, Greece. The presence of carbohydrates was ascertained and plant gum binders (fruit and a mixture of tragacanth and fruit tree gums) were identified in some of the samples. PMID:18023451

Bonaduce, Ilaria; Brecoulaki, Hariclia; Colombini, Maria Perla; Lluveras, Anna; Restivo, Vincenzo; Ribechini, Erika

2007-12-21

204

Hypolipidemic Effects of Guar Gum and Its Enzyme Hydrolysate in Rats Fed Highly Saturated Fat Diets  

Microsoft Academic Search

The effects of guar gum and its enzyme hydrolysate as well as fructooligosaccharide on lipid metabolism were compared in rats fed high-fat diets employing lard or palm oil as dietary fat (25% in the diets). Guar gum and the enzyme hydrolysate greatly increased cecal volatile fatty acid contents to a similar extent. Fructooligosaccharide also increased the variable but to a

Takashi Ide; Hiroshi Moriuchi; Katsuya Nihimoto

1991-01-01

205

Physicochemical Properties of Cissus Gum Powder Extracted with the Aid of Edible Starches  

Microsoft Academic Search

Gum powder was extracted from the stem and root of the cissus (Cissus populnea Guill and perr Ampelidacae) plant using water. Extraction was facilitated by the incorporation of 25–50% edible starches of sweet cassava, sweet potato, and maize. Dry samples were milled and sieved through a 250-µm sieve. Proximate and physicochemical properties of the gum samples were determined using standard

M. O. Iwe; P. O. Obaje; M. A. Akpapunam

2004-01-01

206

Adverse Reaction to Nicotine Gum in Malay Female Smoker: A Case Report  

ERIC Educational Resources Information Center

Nicotine replacement therapies (NRT) are prescribed in smoking cessation programmes to help smokers stop smoking. The ideal dosage of NRT should control cravings and withdrawal symptoms but avoid adverse reactions. This report describes a case of adverse reaction to nicotine gum in a female Malay smoker. Assays taken 2 h after the gum, showed that…

Noorzurani, Md Haris Robson; Bond, Alyson; Wolff, Kim

2008-01-01

207

Effectiveness of nicotine patch and nicotine gum as individual versus combined treatments for tobacco withdrawal symptoms  

Microsoft Academic Search

Nicotine gum and transdermal nicotine have been shown to relieve withdrawal and double success rates over placebo in trials of smoking cessation. This study tested whether combining the two methods would relieve withdrawal more effectively compared to either treatment alone. Twenty-eight smokers served as their own controls in each of four conditions: active gum + active patch (double active), active

K. O. Fagerström; N. G. Schneider; E. Lunell

1993-01-01

208

Physicochemical characteristics and antioxidant activity of Prunus cerasoides D. Don gum exudates.  

PubMed

The physicochemical properties and antioxidant activity of Prunus cerasoides D. Don gum exudates was investigated in this study. The total carbohydrate and protein content were found to be 73.72±2.44% and 2.33±1.25%, respectively. Analysis of monosaccharide composition by HPLC-RI system after acid hydrolysis of the gum showed the presence of arabinose, galactose, glucose, rhamnose and xylose. The molecular weight of the gum was also found to be 5.55×10(5)Da. FTIR and DSC studies showed characteristics typical of a natural polysaccharide. The viscosity of 2% aqueous solution of the gum exhibited non-Newtonian type of flow and the gum was also found to show pH dependent swelling. Determination of the angle of repose, Carr's index and Hausner ratio indicate the gum possess fairly good powder flow property. The antioxidant properties of the gum were evaluated by determining DPPH and hydroxyl scavenging activities, reducing power and total phenolic contents which showed the gum possess antioxidant property. PMID:24875319

Malsawmtluangi, C; Thanzami, K; Lalhlenmawia, H; Selvan, Veenus; Palanisamy, Selvamani; Kandasamy, Ruckmani; Pachuau, Lalduhsanga

2014-08-01

209

Salvadora Persica extract chewing gum and gingival health: Improvement of gingival and probe-bleeding index  

Microsoft Academic Search

Previous studies showed that Persica extracts have antibacterial activity against cariogenic and periodontopathic bacteria and can develop periodontal health; however, the clinical effects of gum as a delivery device for Persica to periodontal health in human, have not yet been investigated. The objective of this study was to evaluate the effect of chewing gum containing Persica extract on periodontal health

Babak Amoian; Ali Akbar Moghadamnia; Soozan Barzi; Sepideh Sheykholeslami; Afsaneh Rangiani

2010-01-01

210

Effect of nicotine chewing gum on plasma nicotine levels of cigarette smokers  

Microsoft Academic Search

This study was designed to determine whether the use of nicotine chewing gum modifies the inhalation and absorption of nicotine by cigarette smokers. Our subjects, 12 subjects who smoked cigarettes regularly, were studied for 4 days. On the first day, they smoked as usual, and on the second, third, and fourth days they also chewed a placebo gum, 2-mg nicotine

Richard V Ebert; McKendree E McNabb; Sharon L Snow

1984-01-01

211

Development and Evaluation of a Novel Dissolution Apparatus for Medicated Chewing Gum Products  

Microsoft Academic Search

A novel dissolution apparatus was developed for medicated chewing gum products. A prototype gum product containing phenylpropa-nolamine hydrochloride (PPA) was used to evaluate the apparatus. The apparatus consists of a conical Teflon base and a rotating, ribbed Teflon plunger suspended in a dissolution vessel. Parameters evaluated were rotation speed, plunger frequency, medium volume, medium type, medium sampling location, number of

James N. Rider; Ed L. Brunson; Walter G. Chambliss; Robert W. Cleary; Ahmed H. Hikal; Peggy H. Rider; Larry A. Walker; Christy M. Wyandt; Alan B. Jones

1992-01-01

212

The Effect of Chewing Sugar-free Gum on Gastro-esophageal Reflux  

Microsoft Academic Search

Regurgitated acid entering the mouth in gastro-esophageal reflux disease can cause dental erosion. Chewing gum could induce increased swallowing frequency, thus improving the clearance rate of reflux within the esophagus. The null hypothesis of this study was that chewing gum does not have any effect on the clearance of reflux from the distal esophagus. Thirty-one subjects presenting with symptoms of

R. Moazzez; D. Bartlett; A. Anggiansah

2005-01-01

213

The management of xerostomia in patients on haemodialysis: comparison of artificial saliva and chewing gum  

Microsoft Academic Search

Many patients on haemodialysis (HD) therapy suffer from a dry mouth and xerostomia. This can be relieved by mechanical and gustatory stimulation or palliative care. The aim of this crossover study was to investigate the effect and preferences of a sugar-free chewing gum (Freedent White) and a xanthan gum-based artificial saliva (Xialine) in the management of xerostomia in chronic HD

Casper P Bots; Henk S Brand; Enno CI Veerman; Marianne Valentijn-Benz; Barbara M Van Amerongen; Nieuw Amerongen van A; Robert M Valentijn; Pieter F Vos; Joost A Bijlsma; Pieter D Bezemer; Piet M ter Wee

2005-01-01

214

Psychological and Pharmacological Influences in Cigarette Smoking Withdrawal: Effects of Nicotine Gum and Expectancy on Smoking Withdrawal Symptoms and Relapse.  

ERIC Educational Resources Information Center

Examined effects of expectancy and nicotine depletion on withdrawal symptoms by giving 109 smokers nicotine gum or placebo. Subjects who believed they had nicotine gum reported fewer physical symptoms of withdrawal, showed less arousal, and smoked fewer cigarettes than did those who thought they had placebo. Actual nicotine content of gum had no…

Gottlieb, Andrew M.; And Others

1987-01-01

215

In vivo predictive release methods for medicated chewing gums.  

PubMed

Understanding the performance of a drug product in vivo plays a key role in the development of meaningful in vitro drug release methodology. In case of functional chewing gums, the mode and the mechanism of release and the site of application differ significantly from other conventional solid oral dosage forms and require a special consideration to extract meaningful information from clinical studies. In the current study, suitable drug release methodology was developed to predict the in vivo performance of an investigated chewing gum product. Different parameters of the drug release testing apparatus described in the Ph. Eur. and Pharmeuropa were evaluated. Drug release data indicate that the parameters, chewing distance, chewing frequency and twisting motion, affect the drug release. Higher drug release was observed when the frequency was changed from 40 chews/min to 60 chews/min for apparatus A and B, as was the case for the twisting motion when changed from 20º to 40º for apparatus B. As far as the chewing distance is concerned, the release rate was in the following order; apparatus A: 0.3 mm > 0.5 mm > 0.7 mm; apparatus B: 1.4 mm > 1.6 mm > 1.8 mm. A suitable apparatus set-up for in vitro release testing was identified. The method will be useful for the establishment of in vitro in vivo correlations (IVIVC) for medicated chewing gums. Interchangeability of the apparatus for a product is not generally recommended without prior knowledge of the performance of the product, as the construction and principle of operation for the apparatus differ considerably. PMID:22674680

Gajendran, Jayachandar; Kraemer, Johannes; Langguth, Peter

2012-10-01

216

Magnetism  

NSDL National Science Digital Library

This radio broadcast discusses the history of magnetism from the time of its discovery by an apocryphal Greek sheperd until the late 16th century and the work of William Gilbert. There is also discussion of who pioneered the study of magnetism, what theories they constructed from its curious abilities, and how the power of the magnet was brought out of the realm of magic and into the service of science. The broadcast concludes with a discussion of why magnetism is still mysterious and how the modern search for the single magnetic pole, or magnetic monopole, could provide a fundamental unit of magnetism, essential for ultimate explanation. The broadcast is 41 minutes and 45 seconds in length.

2010-10-27

217

Mutans Streptococci Dose Response to Xylitol Chewing Gum  

Microsoft Academic Search

Xylitol is promoted in caries-preventive strategies, yet its effective dose range is unclear. This study determined the dose-response of mutans streptococci in plaque and unstimulated saliva to xylitol gum. Participants (n = 132) were randomized: controls (G1) (sorbitol\\/maltitol), or combinations giving xylitol 3.44 g\\/day (G2), 6.88 g\\/day (G3), or 10.32 g\\/day (G4). Groups chewed 3 pellets\\/4 times\\/d. Samples were taken

P. Milgrom; K. A. Ly; M. C. Roberts; M. Rothen; G. Mueller; D. K. Yamaguchi

2006-01-01

218

Use of dye as tracer of drug release from medicated chewing gums.  

PubMed

The evaluation of the potential use of a dye as indicator of in vivo drug release from a medicated chewing gum is described. The device is a three-layer tablet obtained by direct compression consisting of a gum core and two external protective soluble layers to prevent gum adhesion to the punches of the tableting machine. The active ingredient and a colour are contained in the gum core. To evaluate the drug and the dye release from the formulations, a chew-out study was performed by a panel of volunteers. The results obtained suggest that the use of a dye could be useful to indicate the chewing time necessary to complete drug delivery from medicated chewing gums. PMID:17951037

Ochoa, Evelyn; Maggi, Lauretta; Conti, Stefania; Conte, Ubaldo; Vergnault, Guy; Grenier, Pascal

2008-03-01

219

Composition and physicochemical properties of Zedo gum exudates from Amygdalus scoparia.  

PubMed

Composition and physicochemical properties of three types of Zedo gum exudates from Amygdalus scoparia were investigated. Monosaccharide analysis by GC-MS indicated the occurrence of arabinose and galactose as the main sugars. FTIR spectra showed no differences in functional groups among the samples. Steady shear rheological data and power law parameters revealed that the white gum (W) was the most shear sensitive type and had the highest value of consistency coefficient. The mechanical spectra derived from the strain and frequency sweep measurements indicated a liquid viscoelastic behavior for Zedo gum dispersions. GPC-MALLS revealed that the white sample had the highest apparent average molecular weight (4.74 × 10(6)Da) and the lowest dispersity (1.045). TG-DTA analysis showed that the character of gum decomposition significantly depended on the gum type and the white sample had the highest thermal stability. PMID:24299876

Fadavi, Ghasem; Mohammadifar, Mohammad Amin; Zargarran, Azizollaah; Mortazavian, Amir Mohammad; Komeili, Rozita

2014-01-30

220

[Analysis of constituents of ester-type gum bases used as natural food additives].  

PubMed

The differences in the constituents of ten ester-type gum bases used as natural food additives in Japan (urushi wax, carnauba wax, candelilla wax, rice bran wax, shellac wax, jojoba wax, bees wax, Japan wax, montan wax, and lanolin) were investigated. Several kinds of gum bases showed characteristic TLC patterns of lipids. In addition, compositions of fatty acid and alcohol moieties of esters in the gum bases were analyzed by GC/MS after methanolysis and hydrolysis, respectively. The results indicated that the varieties of fatty acids and alcohols and their compositions were characteristic for each gum base. These results will be useful for identification and discrimination of the ester-type gum bases. PMID:18203503

Tada, Atsuko; Masuda, Aino; Sugimoto, Naoki; Yamagata, Kazuo; Yamazaki, Takeshi; Tanamoto, Kenichi

2007-12-01

221

Nicotine gum chewing: A novel strategy to shorten duration of postoperative ileus via vagus nerve activation.  

PubMed

Postoperative ileus (POI) is a transit cessation of bowel motility after surgery. Substantial evidences suggest that gum chewing accelerate the recovery of bowel motility after surgery. Perioperative nicotine administration reduces postoperative opioid use and prevents postoperative nausea and vomiting. Nicotine gum chewing combines stimulation of the cephalic-vagal reflex by gum chewing, and activation of the cholinergic anti-inflammatory pathway by nicotine administration. We therefore hypothesized that nicotine gum chewing reduces POI and improves patient outcomes such as shortening the length of hospitalization as well as saving medical costs. As nicotine gum is commercially available, inexpensive, and has been in use for many years without any severe side effects, it may have a wide clinical application in POI prevention. PMID:24998667

Wu, Z; Boersema, G S A; Jeekel, J; Lange, J F

2014-09-01

222

Guar gum solutions for improved delivery of iron particles in porous media (part 1): porous medium rheology and guar gum-induced clogging.  

PubMed

The present work is the first part of a comprehensive study on the use of guar gum to improve delivery of microscale zero-valent iron particles in contaminated aquifers. Guar gum solutions exhibit peculiar shear thinning properties, with high viscosity in static conditions and lower viscosity in dynamic conditions: this is beneficial both for the storage of MZVI dispersions, and also for the injection in porous media. In the present paper, the processes associated with guar gum injection in porous media are studied performing single-step and multi-step filtration tests in sand-packed columns. The experimental results of single-step tests performed by injecting guar gum solutions prepared at several concentrations and applying different dissolution procedures evidenced that the presence of residual undissolved polymeric particles in the guar gum solution may have a relevant negative impact on the permeability of the porous medium, resulting in evident clogging. The most effective preparation procedure which minimizes the presence of residual particles is dissolution in warm water (60°C) followed by centrifugation (procedure T60C). The multi-step tests (i.e. injection of guar gum at constant concentration with a step increase of flow velocity), performed at three polymer concentrations (1.5, 3 and 4g/l) provided information on the rheological properties of guar gum solutions when flowing through a porous medium at variable discharge rates, which mimic the injection in radial geometry. An experimental protocol was defined for the rheological characterization of the fluids in porous media, and empirical relationships were derived for the quantification of rheological properties and clogging with variable injection rate. These relationships will be implemented in the second companion paper (Part II) in a radial transport model for the simulation of large-scale injection of MZVI-guar gum slurries. PMID:25065767

Gastone, Francesca; Tosco, Tiziana; Sethi, Rajandrea

2014-10-01

223

Guar gum solutions for improved delivery of iron particles in porous media (Part 1): Porous medium rheology and guar gum-induced clogging  

NASA Astrophysics Data System (ADS)

The present work is the first part of a comprehensive study on the use of guar gum to improve delivery of microscale zero-valent iron particles in contaminated aquifers. Guar gum solutions exhibit peculiar shear thinning properties, with high viscosity in static conditions and lower viscosity in dynamic conditions: this is beneficial both for the storage of MZVI dispersions, and also for the injection in porous media. In the present paper, the processes associated with guar gum injection in porous media are studied performing single-step and multi-step filtration tests in sand-packed columns. The experimental results of single-step tests performed by injecting guar gum solutions prepared at several concentrations and applying different dissolution procedures evidenced that the presence of residual undissolved polymeric particles in the guar gum solution may have a relevant negative impact on the permeability of the porous medium, resulting in evident clogging. The most effective preparation procedure which minimizes the presence of residual particles is dissolution in warm water (60 °C) followed by centrifugation (procedure T60C). The multi-step tests (i.e. injection of guar gum at constant concentration with a step increase of flow velocity), performed at three polymer concentrations (1.5, 3 and 4 g/l) provided information on the rheological properties of guar gum solutions when flowing through a porous medium at variable discharge rates, which mimic the injection in radial geometry. An experimental protocol was defined for the rheological characterization of the fluids in porous media, and empirical relationships were derived for the quantification of rheological properties and clogging with variable injection rate. These relationships will be implemented in the second companion paper (Part II) in a radial transport model for the simulation of large-scale injection of MZVI-guar gum slurries.

Gastone, Francesca; Tosco, Tiziana; Sethi, Rajandrea

2014-10-01

224

Assessment of ferula Gummosa gum as a binding agent in tablet formulations.  

PubMed

Ferula gummosa Boiss. (Apiaceae) is one of the natural plants of Iran. The whole plant, but especially the root, contains the gum resin "galbanum". A study of the comparative effects of galbanum gum and two standard binding agents--polyvinylpyrolidone and acacia--on characteristics of acetaminophen and calcium carbonate compacts was made. The Ferula gummosa gum was extracted and its swelling index was determined. Acetaminophen and calcium carbonate granules were prepared using the wet granulation method and were evaluated for their micromeritics and flow properties, while the compacts were evaluated for mechanical properties using the hardness, tensile strength and friability. The drug release from acetaminophen compacts were assessed using dissolution studies. The dry powder of Ferula gummosa gum resin (galbanum) yielded 14% w/w of gum using distilled water as extraction solvent. The swelling index indicates that galbanum gum swelled to about 190% of initial volume in distilled water. Thus galbanum gum has the ability to hydrate and swells in cold water. The bulk and tapped densities and the interspace porosity (void porosity) percent of the granules prepared with different binders showed significant difference. The hardness and tensile strength of acetaminophen and calcium carbonate compacts containing various binders was of the rank order PVP > acacia > galbanum gum (p < 0.05) and the friability percent was of the reverse order (p < 0.05). The ranking for the dissolution rate of tablets containing the different binders was PVP> galbanum gum > acacia. The results of mechanical properties of acetaminophen and calcium carbonate compacts indicate that galbanum gum could be useful to produce tablets with desired mechanical characteristics for specific purposes, and could be used as an alternative substitute binder in pharmaceutical industries. PMID:22568044

Enauyatifard, Reza; Azadbakht, Mohammad; Fadakar, Yousef

2012-01-01

225

Modernization in GUM/HIV services: what does it mean?  

PubMed

Genitourinary medicine services are expected to modernize in order to meet the needs of the NHS in the 21st century. Although increased funding is essential, there is a need for services to look at new ways of delivering care in order to deal with the increasing rate of sexually transmitted infections (STIs) including HIV in the community. This must include a review of skill-mix and roles. Some changes may appear to lower the quality of service. There must be auditing of changes to ensure that standards are not lowered. A short-lived working group was put together at the request of the RCP joint specialty committee for GUM consisting of representatives from diverse GUM clinics which have all been involved in extensive modernization of their service in order to meet demand. This report does not hold all the answers but provides suggestions for clinics wishing to initiate change. Changes must be appropriate to the local population and access pressures. More extreme measures may only be appropriate in the most severely stretched clinics and with consideration of measuring outcomes. PMID:12662386

Robinson, Angela J; Rogstad, Karen

2003-02-01

226

Antioxidant Activity of Pistacia vera Fruits, Leaves and Gum Extracts  

PubMed Central

The side effects of synthetic antioxidants have been considered in different studies. Accordingly, there is an increasing interest toward the use of natural substances instead of the synthetic ones. In this study, the aqueous and ethanolic extracts of Pistacia vera leaves and fruits as well as hydroalcoholic extract of gum were tested for a possible antioxidant activity using in vitro methods. Deoxyribose assay, erythrocyte membrane lipid peroxidation and liver misrosomal non- enzymatic lipid peroxidation tests were used as an in-vitro model for determination antioxidant activity. The extract were evaluated at different concentratios: 25,100, 250, 500 and 1000 ?g/mL. In all procedures, all extracts showed free radical scavenging activity. The effect of ethanolic extract of P. vera fruit at 1000 ?g/mL was quite similar to positive control (DMSO 20 mM) in deoxyribose method. In two other tests, the ethanolic extracts of fruits and leaves were more effective than the aqueous extracts to inhibit malondialdehyde generation. Phytochemical tests showed the presence of flavonoids and tannins in Pistocia vera extracts. The present study showed that extracts of different part of P. vera have antioxidant activity in different in vitro methods. The ethanolic extracts of leaves and fruits showed more roles for antioxidant properties and gum hydroalcoholic extract demonstrated less antioxidant effect. PMID:24250515

Hosseinzadeh, Hossein; Sajadi Tabassi, Sayyed Abolghasem; Milani Moghadam, Negar; Rashedinia, Marzieh; Mehri, Soghra

2012-01-01

227

Gum containing calcium fluoride reinforces enamel subsurface lesions in situ.  

PubMed

The aim of this study was to assess the effect of chewing gum containing phosphoryl oligosaccharides of calcium (POs-Ca) and a low concentration of fluoride (F) on the hardness of enamel subsurface lesions, utilizing a double-blind, randomized, and controlled in situ model. Fifteen individuals wore removable lingual appliances with 3 bovine-enamel insets containing subsurface demineralized lesions. Three times a day for 14 days, they chewed one of the 3 chewing gums (placebo, POs-Ca, POs-Ca+F). After the treatment period, cross-sectional mineral content, nanoindentation hardness, and fluoride ion mapping by time-of-flight secondary ion mass spectrometry (TOF-SIMS) were evaluated. Although there were no statistical differences in overall mineral content and hardness recovery rates between POs-Ca and POs-Ca+F subsurface lesions (p > 0.05), nanoindentation at 1-?m distance increments from the surface showed statistical differences in hardness recovery rate between POs-Ca and POs-Ca+F in the superficial 20-?m region (p < 0.05). Fluoride mapping revealed distribution of the ion up to 20 ?m from the surface in the POs-Ca+F group. Nanoindentation and TOF-SIMS results highlighted the benefits of bioavailability of fluoride ion on reinforcement of the superficial zone of subsurface lesions in situ (NCT01377493). PMID:22337700

Kitasako, Y; Sadr, A; Hamba, H; Ikeda, M; Tagami, J

2012-04-01

228

Rheological characterization and drug release studies of gum exudates of Terminalia catappa Linn.  

PubMed

The present study was undertaken to evaluate the gum exudates of Terminalia catappa Linn. (TC gum) as a release retarding excipient in oral controlled drug delivery system. The rheological properties of TC gum were studied and different formulation techniques were used to evaluate the comparative drug release characteristics. The viscosity was found to be dependent on concentration and pH. Temperature up to 60 degrees C did not show significant effect on viscosity. The rheological kinetics evaluated by power law, revealed the shear thinning behavior of the TC gum dispersion in water. Matrix tablets of TC gum were prepared with the model drug dextromethorphan hydrobromide (DH) by direct compression, wet granulation and solid dispersion techniques. The dissolution profiles of the matrix tablets were compared with the pure drug containing capsules using the USP Basket apparatus with 500 ml phosphate buffer of pH 6.8 as a dissolution medium. The drug release from the compressed tablets containing TC gum was comparatively sustained than pure drug containing capsules. Even though all the formulation techniques showed reduction of dissolution rate, aqueous wet granulation showed the maximum sustained release of more than 8 h. The release kinetics estimated by the power law revealed that the drug release mechanism involved in the dextromethorphan matrix is anomalous transport as indicated by the release exponent n values. Thus the study confirmed that the TC gum might be used in the controlled drug delivery system as a release-retarding polymer. PMID:18661243

Kumar, Sadhis V; Sasmal, Dinakar; Pal, Subodh C

2008-01-01

229

Preparation and evaluation of release characteristics of 3TabGum, a novel chewing device.  

PubMed

A new chewing gum device in the form of a three layers tablet (3TabGum) has been developed. The new drug delivery system is obtained, at room temperature, by direct compression using conventional pharmaceutical equipment. Basically, the resulting chewing gum tablets comprise a gum core combined with two protective antiadherent external layers, which prevent gum adhesion to the punches of the tableting machine. Drug release from a dosage form is the critical step in drug absorption and bioavailability, thus an experimental protocol has been designed to evaluate the efficiency of this kind of therapeutic system by verifying its capability to release the drug dose and by assessing the delivery rate. Simple diffusion into the medium causes the release of only a small percentage of the drug contained in the medicated chewing gum, while the delivery of the major part of the dose occurs during mastication. The results obtained in this study suggest that water soluble drugs are freely and easily released by chewing gums, while for actives characterized by reduced water solubility the release rate depends on the chewing time although all the drugs tested are completely released after a reasonable mastication time. PMID:15784338

Maggi, L; Segale, L; Conti, S; Ochoa Machiste, E; Salini, A; Conte, U

2005-04-01

230

Rheological Behavior of Xanthan Gum Solution Related to Shear Thinning Fluid Delivery for Subsurface Remediation  

SciTech Connect

Xanthan gum, a biopolymer, forms shear thinning fluids which can be used as delivery media to improve the distribution of remedial amendments injected into heterogeneous subsurface environments. The rheological behavior of the shear thinning solution needs to be known to develop an appropriate design for field injection. In this study, the rheological properties of xanthan gum solutions were obtained under various chemical and environmental conditions relevant to delivery of remedial amendments to groundwater. Higher xanthan concentration raised the absolute solution viscosity and increased the degree of shear thinning. Addition of remedial amendments (e.g., phosphate, sodium lactate, ethyl lactate) caused the dynamic viscosity of xanthan gum to decrease, but the solutions maintained shear-thinning properties. Use of simple salt (e.g. Na+, Ca2+) to increase the solution ionic strength also decreased the dynamic viscosity of xanthan and the degree of shear thinning, although the effect is a function of xanthan gum concentration and diminished as the xanthan gum concentration was increased. At high xanthan concentration, addition of salt to the solution increased dynamic viscosity. In the absence of sediments, xanthan gum solutions maintain their viscosity properties for months. However, xanthan gum solutions were shown to lose dynamic viscosity over a period of days to weeks when contacted with saturated site sediment. Loss of viscosity is attributed to physical and biodegradation processes.

Zhong, Lirong; Oostrom, Martinus; Truex, Michael J.; Vermeul, Vincent R.; Szecsody, James E.

2013-01-15

231

Formulation development and evaluation of metformin chewing gum with bitter taste masking  

PubMed Central

Background: Medicated gums are intended to be chewed and act either locally, absorbed via the buccal mucosa or swallowed with saliva. We prepared the metformin gum to overcome its side effects including vomiting, diarrhea, and abdomen discomfort. Furthermore, it could be useful for those who have swallowing problems. Materials and Methods: Metformin hydrochloride (250 mg) with suitable sweeteners was mixed manually for 5 min. This mixture was spray dried, freeze dried, or directly mixed with chewing gum base. Glycerin, xylitol, and menthol were added and the produced paste was kept in the freezer for 2 h to be stable. As the metformin shows bitter taste, we tried to mask this unpleasant taste with using different methods explained. The releasing pattern was evaluated by using a mechanical chewing machine. The best formulation with the optimized releasing pattern, suitable physicochemical properties and pleasant taste were selected. Content uniformity, releasing percent, and other physicochemical properties were identified as well. Taste, flavor, and appearance characteristics were evaluated by using a self-made questionnaire based on the hedonic test method. Results: The chewing gum dosage content was about 86.2%. The release rate of metformin chewing gum was about 70% after 5 min of mastication. Masking the bitter taste of drug was achieved by using acesulfame-isomalt as sweeteners and prepared it by freeze drying equipment. Conclusion: Metfornin chewing gum had suitable appearance and appropriate invitro characteristics that fallow the pharmacopeia suggestions. This chewable gum showed bitterness suppression with a suitable release rate. PMID:24800181

Mostafavi, Sayed Abolfazl; Varshosaz, Jaleh; Arabian, Saber

2014-01-01

232

[Sugar of substitute stevioside in chewing gum: comparative double blind controllable study].  

PubMed

In double blind controllable study on 126 volunteers - students of medical academy - influence on ?? the mixed saliva of 5 kinds of chewing gums with the different contents of substitute of sugar as xylitol and sorbitol, and also the chewing sweets R.O.C.S., two kinds of chewing gums containing a basis with substitute of sugar stevioside (1.25 and 2.5%) and placebo (a basis without additives) were investigated. Products chewed within 10 minutes. In one of groups surveyed such chewing was preceded with rinsing a mouth by a test solution of saccharose. ?? determined within 30 minutes. At chewing gums with substitute of sugar displacement ?? the mixed saliva in the alkaline side was revealed a different degree. Thus gums with stevioside did not concede and even surpassed in this action of chewing gums with other substitutes of sugar. In comparison with placebo chewing gums and sweets restored acid-alkaline balance of oral cavities faster. Hence, use of stevioside in structure of chewing gum allows at preservation of its positive actions in oral cavity essentially to reduce concentration substitute of sugar and, hence, its collateral action by an organism. PMID:21378715

Rumiantsev, V A; Beliaev, V V; Zubtsov, V A; Esaian, L K; Namestnikova, I V

2011-01-01

233

Magnetism  

NSDL National Science Digital Library

This overview of magnetism provides a brief history prior to 1600 and continues with the work of William Gilbert, Hans Christian Oersted, and Andre-Marie Ampere in describing and exploring the magnetosphere and learning the role that electric current plays in producing magnetism. Magnetic field lines are then discussed, citing the work of Michael Faraday. The work of James Clerk Maxwell and Heinrich Hertz is mentioned in a discussion of the relationship of light waves and radio waves as part of the electromagnetic spectrum.

Stern, David

234

Study of algal biomass harvesting using cationic guar gum from the natural plant source as flocculant.  

PubMed

Microalgae are small in size with negatively charged surface. They are usually stable in suspension culture and hard to flocculate. The present work emphasizes on the synthesis of cationic guar gum (CGG) by the introduction of quaternary amine groups onto the backbone of guar gum (GG) from N-(3-chloro-2-hydroxypropyl) trimethyl ammonium chloride (CHPTAC). The optimal dosage of the synthesized cationic guar gum is used to flocculate two different green algae viz. Chlorella sp. CB4 and Chlamydomonas sp. CRP7. PMID:23218353

Banerjee, Chiranjib; Ghosh, Sandipta; Sen, Gautam; Mishra, Sumit; Shukla, Pratyoosh; Bandopadhyay, Rajib

2013-01-30

235

Chewing gum intake in Europe: a survey of intakes in France, Germany, Italy, Spain and the UK.  

PubMed

A limited number of studies have examined chewing gum intakes in Europe. In the current study, chewing gum intakes were estimated in children, adolescents and adults via customised online questionnaires developed to collect data on patterns of chewing gum consumption (including usage, duration and gum variety) in September and October 2011. A total sample of chewing gum consumers composed of 1001 children and 5186 adolescents and adults from five European countries was included in the survey, with 79% and 66% of children and adolescents/adults reporting chewing gum in the previous 3 and 6 months, respectively. The intake of chewing gum on a per g basis was estimated by establishing the mean weights of each form of gum, and using factors for the frequency of chewing gum intake obtained through the online survey. Intakes of chewing gum at the mean, 90th and 95th percentile in children were 1.87, 3.79 and 6.59 g day(-1) (equivalent to 0.75, 1.67 and 2.40 pieces/day), respectively. In adolescents and adults, intakes at the mean, 90th and 95th percentile were 1.87, 5.40 and 8.00 g day(-1) (equivalent to 0.98, 3.00 and 4.00 pieces/day), respectively. Intakes were similar across the five countries. Chewing gum use was significantly higher in older compared with younger children and was significantly higher in adolescents compared with older adults. The data reported herein provide a reliable resource for chewing gum intakes in Europe and will be important for estimating exposure to food additives and flavourings intended for use in chewing gum. PMID:24720761

Hearty, Áine; Lau, Annette; Roberts, Ashley

2014-01-01

236

Development and evaluation of a novel dissolution apparatus for medicated chewing gum products.  

PubMed

A novel dissolution apparatus was developed for medicated chewing gum products. A prototype gum product containing phenylpropanolamine hydrochloride (PPA) was used to evaluate the apparatus. The apparatus consists of a conical Teflon base and a rotating, ribbed Teflon plunger suspended in a dissolution vessel. Parameters evaluated were rotation speed, plunger frequency, medium volume, medium type, medium sampling location, number of plunger ribs, and number of gum pieces. Samples were taken over a 20-min period and samples were analyzed by HPLC. Cumulative percentage released-versus-time profiles were obtained for each parameter evaluated. Statistical analysis of the gum product indicated that the only significant differences occurred at the lowest rotation speed and lowest plunger frequencies. A Level A correlation was found between the in vitro release profile for the 20-rpm and 30-cycles/min plunger frequency and the in vivo chew-out study. PMID:1553351

Rider, J N; Brunson, E L; Chambliss, W G; Cleary, R W; Hikal, A H; Rider, P H; Walker, L A; Wyandt, C M; Jones, A B

1992-02-01

237

Ethephon-Induced Gummosis in Sour Cherry (Prunus cerasus L.) : II. Flow Characteristics of Gum Solutions.  

PubMed

Flow of sour cherry (Prunus cerasus L. cv. Montmorency) gum solutions through a glass capillary was Newtonian for pressure gradients from 0 to 1.8 megapascals per meter, and hydraulic conductance was inversely proportional to solution viscosity in this range. However, flow became plastic at pressure gradients above 1.8 megapascals per meter, resulting in a decrease in solution viscosity. The magnitude of this effect diminished as gum concentration increased. Flow of water, a solution of the component sugar monomers of sour cherry gum, and sucrose solutions remained Newtonian over the entire pressure gradient range examined (0-4 megapascals per meter). Plastic flow of gum solutions in the vessels of intact sour cherry shoots is possible under pressure gradients induced by transpiration when high resistance to flow occurs over short distances. PMID:16662533

Olien, W C; Bukovac, M J

1982-08-01

238

ISO/GUM UNCERTAINTIES AND CIAAW (UNCERTAINTY TREATMENT FOR RECOMMENDED ATOMIC WEIGHTS AND ISOTOPIC ABUNDANCES)  

SciTech Connect

The International Organization for Standardization (ISO) has published a Guide to the expression of Uncertainty in Measurement (GUM). The IUPAC Commission on Isotopic Abundance and Atomic Weight (CIAAW) began attaching uncertainty limits to their recommended values about forty years ago. CIAAW's method for determining and assigning uncertainties has evolved over time. We trace this evolution to their present method and their effort to incorporate the basic ISO/GUM procedures into evaluations of these uncertainties. We discuss some dilemma the CIAAW faces in their present method and whether it is consistent with the application of the ISO/GUM rules. We discuss the attempt to incorporate variations in measured isotope ratios, due to natural fractionation, into the ISO/GUM system. We make some observations about the inconsistent treatment in the incorporation of natural variations into recommended data and uncertainties. A recommendation for expressing atomic weight values using a tabulated range of values for various chemical elements is discussed.

HOLDEN,N.E.

2007-07-23

239

Unknown syndrome: microcephaly, hypoplastic nose, exophthalmos, gum hyperplasia, cleft palate, low set ears, and osteosclerosis  

Microsoft Academic Search

We report a neonate, born at term, with microcephaly, a hypoplastic nose, exophthalmos, gum hyperplasia, cleft palate, and low set ears, who died at 86 minutes of age. Radiographs showed diffuse sclerosis of the bones.

J Raine; R M Winter; A Davey; S M Tucker

1989-01-01

240

Origin and thermodynamic properties of the instability of synthetic azo colorants in gum arabic solutions.  

PubMed

The instability of some industrially important synthetic azo colorants, including sunset yellow, azorubine, and allura red, toward gum arabic in aqueous solution has been a long-standing problem for the beverage and confectionery industries. Precipitation of these colorants causes the deterioration of product appearance and properties. This work examines the origin and nature of the problem by analysis of the precipitate and thermodynamic studies of gum arabic-colorant interactions using isothermal titration calorimetry (ITC). The presence of divalent alkaline earth metals in gum arabic samples, that is, calcium and magnesium, is shown to be responsible for the precipitation of the azo colorants. There is no direct interaction between gum arabic and the colorant molecules, and the precipitate is formed likely due to the mediation/bridging by the divalent cations. The thermodynamic knowledge gained from the ITC studies, for example, binding affinity, stoichiometry, and enthalpy, enables interpretation of many industrial observations. PMID:17910512

Fang, Yapeng; Al-Assaf, Saphwan; Sakata, Makoto; Phillips, Glyn O; Schultz, Matthias; Monnier, Vivianne

2007-10-31

241

Synthesis and characterization of novel guar gum hydrogels and their use as Cu2+ sorbents.  

PubMed

To prepare novel hydrogels for use in water technologies, guar gum was subjected to acid hydrolysis. The depolymerized guar gum obtained there from and the native guar gum were oxidized to their respective polycarboxylic forms using NO(x) as oxidant. All these polymers were crosslinked with N,N-methylenebisacrylamide, and were used as Cu(2+) sorbents. The candidate hydrogel exhibiting the highest uptake was used further to investigate the effect of external stimuli on sorption. The sorption on hydrogels was fast as the highest sorption was observed after 2 h at 40 degrees C and 20 ppm of Cu(2+) ions. The hydrogel prepared from the oxidized guar gum afforded the maximum sorption capacity of 125.893 mg g(-1). Langmuir and Freundlich isotherms, and pseudo second order kinetics matches the experimental data. The evidence of sorption was obtained by characterizing Cu(2+)-loaded hydrogels by FTIR spectroscopy. PMID:19342225

Chauhan, Kalpana; Chauhan, Ghanshyam S; Ahn, J-H

2009-07-01

242

Application and Characterization of Gum from Bombax buonopozense Calyxesas an Excipient in Tablet Formulation  

PubMed Central

This study was undertaken to explore gum from Bombax buonopozense calyxes as a binding agent in formulation of immediate release dosage forms using wet granulation method. The granules were characterized to assess the flow and compression properties and when compressed, non-compendial and compendial tests were undertaken to assess the tablet properties for tablets prepared with bombax gum in comparison with those prepared with tragacanth and acacia gums. Granules prepared with bombax exhibited good flow and compressible properties with angle of repose 28.60°, Carr’s compressibility of 21.30% and Hausner’s quotient of 1.27. The tablets were hard, but did not disintegrate after one hour. Furthermore, only 52.5% of paracetamol was released after one hour. The drug release profile followed zero order kinetics. Tablets prepared with bombax gum have the potential to deliver drugs in a controlled manner over a prolonged period at a constant rate. PMID:24300296

Ngwuluka, Ndidi C.; Kyari, Jehu; Taplong, John; Uwaezuoke, Onyinye J.

2012-01-01

243

The Quantitative Determination of Butylated Hydroxytoluene in Chewing Gum Using GC--MS  

ERIC Educational Resources Information Center

The experiment to measure concentration of Photophysical Characterization(BHT) and determine percent recovery in chewing gum is described. The results demonstrated that over time, the concentration of BHT in the extract decreased owing to aerial oxidation.

Witter, A. E.

2005-01-01

244

Prebiotic Properties of Yeast Cell Wall Mannanoligosaccharides and Guar Gum Galactomannans in Starting Broilers  

E-print Network

Two studies were designed to evaluate the growth promoting and prebiotic properties of Yeast Cell Wall (YCW) containing mannanoligosaccharides (MOS) and guar gum galactomannans in starting broilers. In study one, the effects of different sources...

Kakani, Radhika

2013-12-04

245

Gas chromatographic–mass spectrometric characterisation of plant gums in samples from painted works of art  

Microsoft Academic Search

This paper presents an analytical GC–MS procedure to study the chemical composition of plant gums, determining aldoses and uronic acids in one step. The procedure is based on the silylation of aldoses and uronic acids, released from plant gums by microwave assisted hydrolysis, and previously converted into the corresponding diethyl-dithioacetals and diethyl-dithioacetal lactones. Using this method only one peak for

Ilaria Bonaduce; Hariclia Brecoulaki; Maria Perla Colombini; Anna Lluveras; Vincenzo Restivo; Erika Ribechini

2007-01-01

246

Characterization of xanthan gum biosynthesis in a centrifugal, packed-bed reactor using metabolic flux analysis  

Microsoft Academic Search

Xanthan gum biosynthesis in a centrifugal, packed-bed reactor (CPBR) was characterized using metabolic flux analysis. Metabolic fluxes through the carbon pathways for xanthan gum production by Xanthomonas campestris were calculated by the metabolic flux-based stoichiometric model. Use of 5.0% instead of 2.5% glucose resulted in an enhanced glucose uptake rate (?s) in all bioreactors. The ?s values in CPBR were

Chia-Hua Hsu; Y. Martin Lo

2003-01-01

247

Compaction, compression and drug release characteristics of xanthan gum pellets of different compositions  

Microsoft Academic Search

Compaction and compression of xanthan gum (XG) pellets were evaluated and drug release from tablets made of pellets was characterised. Three formulations were prepared by extrusion–spheronisation and included, among other excipients, diclofenac sodium (Dic Na), at 10% (w\\/w); xanthan gum, at 16% (w\\/w); and one of three different fillers (lactose monohydrated (LAC), tribasic calcium phosphate (TCP) and ?-cyclodextrin (?-CD)), at

Helton Santos; Francisco Veiga; M Pina; João José Sousa

2004-01-01

248

Formulation variables affecting drug release from xanthan gum matrices at laboratory scale and pilot scale  

Microsoft Academic Search

The purpose of this research was to study processing variables at the laboratory and pilot scales that can affect hydration\\u000a rates of xanthan gum matrices containing diclofenac sodium and the rate of drug release. Tablets from the laboratory scale\\u000a and pilot scale proceedings were made by wet granulation. Swelling indices of xanthan gum formulations prepared with different\\u000a amounts of water

Nashiru Billa; Kah-Hay Yuen

2000-01-01

249

Effect of carboxymethylcellulose and xanthan gum on rheological profile of dried maize masa  

Microsoft Academic Search

Maize masa was obtained using a traditional nixtamalisation process, and then freeze-dried to obtain dried masa. Both masa\\u000a dispersions with 10%(w\\/V) total solids control (DM), masa dispersions mixed with carboxymethylcellulose (CMC) and xanthan gum (0.2% and 0.5%(mass\\u000a fraction) gum solids) named masa with hydrocolloid (DMH) were prepared by distilled water, and the rheological properties were tested. Dynamic oscillatory measurements were

Andrés Aguirre-Cruz; Guadalupe Méndez-Montealvo; Javier Solorza-Feria; Luis Arturo Bello-Pérez

2007-01-01

250

Production of vermifertilizer from guar gum industrial wastes by using composting earthworm Perionyx sansibaricus (Perrier)  

Microsoft Academic Search

Efforts have been made to convert the guar gum industrial waste into a value-added product, by employing a new earthworm species\\u000a for vermicomposting e.g. Perionyx sansibaricus (Perrier) (Megascolecidae), under laboratory conditions. Industrial lignocellulosic waste was amended with other organic\\u000a supplements (saw dust and cow dung); and three types of vermibeds were prepared: guar gum industrial waste + cow dung + saw\\u000a dust in 40:

Surendra Suthar

2007-01-01

251

Nicotine-containing chewing gum as an anti-smoking aid  

Microsoft Academic Search

Chewing gum containing nicotine or placebo was given to smokers attending an anti-smoking clinic. During a one week double-blind study subjects receiving nicotine smoked less and chewed less gum than those receiving placebo. The difference in tobacco consumption between the two treatment groups was most apparent among previous heavy smokers. During a 6 month follow-up phase all subjects were offered

B. Brantmark; P. Ohlin; H. Westling

1973-01-01

252

Effects of Chewing Sorbitol Gum and Paraffin on Human Interproximal Plaque pH  

Microsoft Academic Search

The effects of chewing sorbitol-containing gum and paraffin upon human interproximal plaque pH responses after consumption of a jelly donut were investigated in this study. Prolonged plaque pH responses were observed following consumption of the jelly donut. Dramatic rises in pH resulted when sorbitol gum and paraffin were chewed 15 min after consumption of the donut. Ten minutes of chewing

M. E. Jensen

1986-01-01

253

Polyol Chewing Gums and Caries Rates in Primary Dentition: A 24Month Cohort Study  

Microsoft Academic Search

The effect of 2-year chewing-gum use on the caries rates of primary teeth was studied in a combined school and home program in a sample of 510 initially 6-year-old subjects with high caries experience, low availability of fluoride, and difficult access to dental care. The gum, formed into either sticks or pellets, comprised either xylitol, sorbitol, or mixtures thereof The

K. K. Mäkinen; P. P. Hujoel; C. A. Bennett; K. P. Isotupa; P.-L. Mäkinen; P. Allen

1996-01-01

254

The erosive effects of saliva following chewing gum on enamel and dentine: an ex vivo study  

Microsoft Academic Search

Objectives The primary objective was to determine the erosive effect of expectorated saliva, following chewing acidic gum, on enamel and dentine samples, using a non-acidic gum as a negative control. Secondary objectives were to determine the effect of brushing enamel and dentine samples and the effect of individual saliva pH and buffering.Design A single-centre, single-blind, placebo-controlled, two-way crossover study.Setting A

E. M. Paice; R. W. Vowles; N. X. West; S. M. Hooper

2011-01-01

255

Comparison of nicotine chewing-gum and psychological treatments for dependent smokers  

Microsoft Academic Search

The results of using nicotine chewing-gum to treat dependent smokers attending a withdrawal clinic were compared with the results of psychological treatment. At one-year follow-up 26 (38%) out of 69 people who received nicotine gum were abstinent compared with seven (14%) out of 49 who received psychological treatment (p < 0.01). Abstinence was confirmed by the measurement of carboxyhaemoglobin concentrations

M Raw; M J Jarvis; C Feyerabend; M A Russell

1980-01-01

256

Anti-stress effects of chewing gum prepared with yeast hydrolysate  

Microsoft Academic Search

In this study, we investigated the anti-stress effects of chewing gum prepared with yeast hydrolysate (SCP) in the general\\u000a Korean population using heart rate value (HRV) analysis and the Beck depression inventory (BDI) and Beck anxiety inventory\\u000a (BAI). Four different kinds of chewing gum (weight 960 ± 2 mg) were designed: three with different concentrations of SCP (30,\\u000a 85, and 250 mg\\/piece) combined with

Hyung Joo Suh; Seong Yeong Kim; Un Jae Chang; Jin Man Kim

2008-01-01

257

Sugarless gum chewing before surgery does not increase gastric fluid volume or acidity  

Microsoft Academic Search

Patients occasionally arrive in the operating suite chewing gum despite instructions to avoid oral intake for a specific number\\u000a of hours before surgery. Some anaesthetists are hesitant to proceed with these patients fearing an increase in gastric volume\\u000a and acidity. This study was undertaken to determine if gum chewing increased gastric volume and acidity. Seventy seven patients\\u000a were recruited and

Stevin A. Dubin; Holly G. Jense; Jody M. McCranie; Victor Zubar

1994-01-01

258

Effect of guar gum on glucose and lipid metabolism in white sea bream Diplodus sargus.  

PubMed

The aim of this study was to assess the role of soluble non-starch polysaccharide (guar gum) on white sea bream Diplodus sargus, glucose and lipid metabolism. A control diet was formulated to contain 40 % crude protein, 14 % crude lipids and 35 % pregelatinized maize starch, and three other diets were formulated similar to the control diet except for guar gum, which was included at 4 % (diet GG4), 8 % (diet GG8) or 12 % (diet GG12). Diets were fed to the fish for 9 weeks on a pair-feeding scheme. Guar gum had no effect on growth performance, feed efficiency, glycaemia, cholesterolaemia and plasma triacylglyceride levels. Hepatic glucokinase and pyruvate kinase activities, liver glycogen content and liver insulin-like growth factor-I gene expression were not affected by dietary guar gum, while fructose-1,6-bisphosphatase activity was lower in fish fed guar gum-supplemented diets. Hepatic glucose-6-phosphate dehydrogenase activity was higher in fish fed diets GG4 and GG8 than in the control group. Overall, data suggest that in contrast to mammals guar gum had no effect on white sea bream glucose utilization and in lowering plasma cholesterol and triacylglyceride levels. However, it seems to contribute to lower endogenous glucose production. PMID:22763699

Enes, P; Pousão-Ferreira, P; Salmerón, C; Capilla, E; Navarro, I; Gutiérrez, J; Oliva-Teles, A

2013-04-01

259

Gum arabic/starch/maltodextrin/inulin as wall materials on the microencapsulation of rosemary essential oil.  

PubMed

The effects of the partial or total replacement of gum arabic by modified starch, maltodextrin and inulin on the characteristics of rosemary essential oil microencapsulated by spray drying were evaluated in this study. The lowest level of water absorption under conditions of high relative humidity was observed in treatments containing inulin. The wettability property of the powders was improved by the addition of inulin. The total replacement of gum arabic by modified starch or a mixture of modified starch and maltodextrin (1:1, m/m) did not significantly affect the efficiency of encapsulation, although higher Tg values were exhibited by microcapsules prepared using pure gum arabic or gum arabic and inulin. 1,8-cineol, camphor and ?-pinene were the main components identified by gas chromatography in the oils extracted from the microcapsules. The particles had smoother surfaces and more folds when gum arabic or inulin was present. Larger particles were observed in the powders prepared with pure gum arabic or modified starch. PMID:24299808

Fernandes, Regiane Victória de Barros; Borges, Soraia Vilela; Botrel, Diego Alvarenga

2014-01-30

260

Efficacy of baking soda-containing chewing gum in removing natural tooth stain.  

PubMed

A 14-week, double-blind, randomized clinical trial was conducted with 126 healthy volunteers to compare the efficacy of twice-daily use of 3 baking soda-containing chewing gums in removing natural tooth stain when used in conjunction with a program of regular oral hygiene. All 3 chewing gums significantly reduced extrinsic stain (P < .0001) and improved the whitened appearance of teeth (P < .0001) at both the 2-week interim and the final 4-week evaluations. ARM & HAMMER DENTAL CARE The Baking Soda Gum (AHDC) reduced dental stain by 70.8%, compared to reductions of 71.9% and 65.3%, after use of 2 experimental gum formulations. Whitened appearance improved by 1.73 shade tabs using AHDC gum, and up to 2.49 shade tabs with the experimental formulations. These results suggest that the use of baking soda-containing gum after meals, in conjunction with good oral hygiene, can improve both extrinsic dental staining and the whitened appearance of teeth. PMID:11913307

Mankodi, S M; Conforti, N; Berkowitz, H

2001-07-01

261

Effect of Gum Chewing on the Recovery From Laparoscopic Colorectal Cancer Surgery  

PubMed Central

Purpose We aimed to examine the effect of gum chewing after laparoscopic colorectal cancer surgery. Methods We reviewed the medical records of patients who underwent laparoscopic colorectal cancer surgery in Incheon St. Mary's Hospital, The Catholic University of Korea School of Medicine. We divided the patients into 2 groups: group A consisted of 67 patients who did not chew gum; group B consisted of 65 patients who chewed gum. We analyzed the short-term clinical outcomes between the two groups to evaluate the effect of gum chewing. Results The first passage of gas was slightly earlier in group B, but the difference was not significant. However, the length of hospital stay was 6.7 days in group B, which was significantly shorter than that in group A (7.3 days, P = 0.018). Conclusion This study showed that length of postoperative hospital stay was shorter in the gum-chewing group. In future studies, we expect to elucidate the effect of gum chewing on the postoperative recovery more clearly. PMID:24466540

Hwang, Duk Yeon; Kim, Ho Young; Kim, Ji Hoon; Lee, In Gyu; Kim, Jun Ki; Oh, Seung Taek

2013-01-01

262

Glucose absorption, hormonal release and hepatic metabolism after guar gum ingestion  

NASA Technical Reports Server (NTRS)

Six non-anaesthetized Large White pigs (mean body weight 59 +/- 1.7 kg) were fitted with permanent catheters in the portal vein, the brachiocephalic artery and the right hepatic vein and with electromagnetic flow probes around the portal vein and the hepatic artery. The animals were provided a basal none-fibre diet (diet A) alone or together with 6% guar gum (diet B) or 15% purified cellulose (diet C). The diets were given for 1 week and according to a replicated 3 x 3 latin-square design. On the last day of each adaptation period test meals of 800 g were given prior to blood sampling. The sampling was continued for 8 h. Guar gum strongly reduced the glucose absorption as well as the insulin, gastric inhibitory polypeptide (GIP) and insulin-like growth factor-1 (IGF-1) production. However, the reduction in peripheral blood insulin levels caused by guar gum was not associated with a change in hepatic insulin extraction. IGF-1 appeared to be strongly produced by the gut. The liver had a net uptake of the peptide. Ingestion of guar gum increased the hepatic extraction coefficient of gut produced IGF-1. Guar gum ingestion also appeared to decrease pancreatic glucagon secretion. Cellulose at the level consumed had very little effect on the parameters considered. It is suggested that the modulation of intestinal mechanisms by guar gum was sufficient to mediate the latter internal metabolic effects.

Simoes Nunes, C.; Malmlof, K.

1992-01-01

263

Implications of partial conjugation of whey protein isolate to durian seed gum through Maillard reactions: foaming properties, water holding capacity and interfacial activity.  

PubMed

This paper deals with the conjugation of durian seed gum (DSG) with whey protein isolate (WPI) through Maillard reactions. Subsequently, the functional properties of durian seed gum in the non-conjugated (control sample) and conjugated forms were compared with several commercial gums (i.e., Arabic gum, sodium alginate, kappa carrageenan, guar gum, and pectin). The current study revealed that the conjugation of durian seed gum with whey protein isolate significantly (p < 0.05) improved its foaming properties. In this study, the conjugated durian seed gum produced the most stable foam among all samples. On the other hand, the emulsion stabilized with the conjugated durian seed gum also showed more uniform particles with a larger specific surface area than the emulsion containing the non-conjugated durian seed gum. The conjugated durian seed gum showed significant different foaming properties, specific surface area, particle uniformity and water holding capacity (WHC) as compared to the target polysaccharide gums. The conjugated durian seed gum showed more similar functional properties to Arabic gum rather than other studied gums. PMID:24322494

Amid, Bahareh Tabatabaee; Mirhosseini, Hamed; Poorazarang, Hashem; Mortazavi, Seyed Ali

2013-01-01

264

Comparison of guar gum from different sources for the preparation of prolonged-release or colon-specific dosage forms.  

PubMed

The aim of the present study was to compare some physicochemical properties of guar gum samples from different sources and thus to investigate the suitability of these samples for the formulation of either prolonged-release or colon-specific dosage forms. Twelve different guar gum samples from India, Pakistan and the USA were used. Theophylline was chosen as a model drug. The flow type of the guar gum samples was determined as pseudoplastic. The viscosity and the particle size of the guar gum samples were found to be the main parameters which could affect the drug release from matrix tablets. All of the guar gum samples are suitable for use in the preparation of prolonged-release matrix tablets. But, three of them, obtained from India and the USA, may be potentially the most suitable guar gum samples for the preparation of colon-specific dosage forms. PMID:19519181

Acartürk, Füsun; Celkan, Arma?an

2009-01-01

265

Effects of a Baking Soda Gum on extrinsic dental stain: results of a longitudinal 4-week assessment.  

PubMed

An evaluation of the effects of ARM & HAMMER DENTAL CARE The Baking Soda Gum (AHDC) on extrinsic dental stain was made in 48 subjects presenting with measurable extrinsic stain. The subjects were randomized to use either the baking soda gum or a non-baking soda placebo gum for 20 minutes twice daily after lunch and dinner while brushing once daily. The procedure of limited brushing was chosen to simulate the level of hygiene normally practiced by participants entering a clinical study. After 4 weeks, the reduction in measurable extrinsic stain in the baking soda gum group was statistically significant (P = .0044) relative to baseline. Statistical analysis of the placebo gum group revealed no significant change in extrinsic stain from baseline. The magnitude of the unadjusted longitudinal reduction in extrinsic stain in the baking soda gum group was 29.7% at 4 weeks. PMID:11913306

Soparkar, P; Newman, M B

2001-07-01

266

Influence of different purification and drying methods on rheological properties and viscoelastic behaviour of durian seed gum.  

PubMed

The aim of the present study was to investigate the effects of different purification and drying methods on the viscoelastic behaviour and rheological properties of durian seed gum. The results indicated that the purified gum A (using isopropanol and ethanol) and D (using hydrochloric acid and ethanol) showed the highest and lowest viscosity, respectively. Four drying techniques included oven drying (105 °C), freeze drying, spray drying and vacuum oven drying. In the present work, all purified gums exhibited more elastic (gel-like) behaviour than the viscous (liquid-like) behaviour (G?gum. The freeze-dried gum and oven-dried (105 °C) gum exhibited the highest and lowest viscous modulus (G?), respectively. PMID:24751065

Amid, Bahareh Tabatabaee; Mirhosseini, Hamed

2012-09-01

267

Effects of Nine Different Chewing-Gums and Lozenges on Salivary Flow Rate and pH  

Microsoft Academic Search

The objectives of this study were to determine how salivary flow rate and pH vary with time during use of chewing-gums and lozenges. Twenty-four young adults collected unstimulated saliva and then, on different occasions, chewed one of six flavoured gums, or gum base, or sucked on one of two lozenges, for 20 min, during which time eight separate saliva samples

C. Dawes; L. M. D. Macpherson

1992-01-01

268

Jumping mechanisms in gum treehopper insects (Hemiptera, Eurymelinae).  

PubMed

Jumping in a species of Australian gum treehopper was analysed from high-speed images. Pauroeurymela amplicincta adults and nymphs lived together in groups that were tended by ants, but only adults jumped. The winged adults with a body mass of 23 mg and a body length of 7 mm had some morphological characteristics intermediate between those of their close relatives the leafhoppers (Cicadellidae) and the treehoppers (Membracidae). They, like leafhoppers, lacked the prominent prothoracic helmets of membracid treehoppers, and their large hind coxae were linked by press studs (poppers), that are present in leafhoppers but not treehoppers. The hindlegs were only 30-40% longer than the other legs and 67% of body length. They are thus of similar proportion to the hindlegs of treehoppers but much shorter than those of most leafhoppers. Jumping was propelled by the hindlegs, which moved in the same plane as each other beneath and almost parallel to the longitudinal axis of the body. A jump was preceded by full levation of the coxo-trochanteral joints of the hindlegs. In its best jumps, the rapid depression of these joints then accelerated the insect in 1.4 ms to a take-off velocity of 3.8 m s(-1) so that it experienced a force of almost 280 g. In 22% of jumps, the wings opened before take-off but did not flap until the gum treehopper was airborne, when the body rotated little in any plane. The energy expended was 170 ?J, the power output was 122 mW and the force exerted was 64 mN. Such jumps are predicted to propel the insect forwards 1450 mm (200 times body length) and to a height of 430 mm if there is no effect of wind resistance. The power output per mass of jumping muscle far exceeded the maximum active contractile limit of muscle and indicates that a catapult-like action must be used. This eurymelid therefore out-performs both leafhoppers and treehoppers in i ts faster acceleration and in its higher take-off velocity. PMID:23619401

Burrows, Malcolm

2013-07-15

269

Substitutes for tobacco smoking: a behavioral economic analysis of nicotine gum, denicotinized cigarettes, and nicotine-containing cigarettes.  

PubMed

Both pharmacological and nonpharmacological stimuli may be responsible for the reinforcement and maintenance of tobacco smoking. The present study examined the self-administration of nicotine gum, denicotinized cigarettes, and nicotine-containing cigarettes utilizing a behavioral economic design in order to investigate the pharmacological and nonpharmacological aspects of cigarette smoking. Cigarette-deprived, dependent smokers worked for cigarette puffs and nicotine gum in daily operant sessions. In one phase, nicotine-containing cigarettes were available at increasing unit prices across sessions. Three phases replicated these sessions with nicotine gum, denicotinized cigarettes, or both, concurrently available at a constant unit price. As nicotine-containing cigarette unit price increased, consumption decreased. However, as nicotine-containing cigarette unit price increased, nicotine gum and denicotinized cigarette consumption increased. Consumption of nicotine gum, but not denicotinized cigarettes, diminished when all three reinforcers were concurrently available. Concurrently available denicotinized cigarettes, but not nicotine gum, caused a statistically significant reduction in nicotine-containing cigarette consumption. In another phase, denicotinized cigarettes were available at increasing unit prices across sessions while nicotine gum was concurrently available at a constant unit price. This phase demonstrated that nicotine content had no reliable effect on cigarette or nicotine gum consumption. These results suggest that denicotinized cigarettes are a more effective alternative reinforcer than nicotine gum, indicating that nonpharmacological stimuli of smoking merit attention in smoking cessation treatment. Furthermore, these findings indicate that alternative reinforcement would be most effective in smoking cessation treatment when combined with high prices for cigarettes. PMID:15194203

Johnson, Matthew W; Bickel, Warren K; Kirshenbaum, Ari P

2004-06-11

270

Study of water vapour permeability of protein and gum-based edible films by a photothermal method  

NASA Astrophysics Data System (ADS)

The water vapour permeability of protein and gum-based edible films was studied by means of a photothermal method. The films were prepared with two basic ingredients, whey protein concentrate and mesquite gum, according to the proportions 75:25, 50:50, 25:75, and 0:100 (weight:weight). The water vapour diffusion coefficient of the analyzed films was found within the interval 0.37 × 10-6 to 2.04 × 10-6 cm^2/s, increasing linearly by increasing the mesquite gum composition in the films. The incorporation of mesquite gum in films produces less effective moisture barriers due to its highly hydrophilic property.

Tomás, S. A.; Saavedra, R.; Cruz, A.; Pedroza-Islas, R.; San Martín, E.

2005-06-01

271

A two-colored chewing gum test for assessing masticatory performance: a preliminary study.  

PubMed

This study was conducted to compare subjective and objective assessment methods of a two-colored chewing gum test and to find out whether these methods are capable of discriminating masticatory performances between sexes. 31 adults, 16 males and 15 females participated in this study. Each subject chewed five samples of two-colored chewing gum sticks for 5, 10, 20, 30 and 50 chewing strokes, respectively. The subjective color-mixing and shape indices for the gum bolus (SCMI-B, SSI-B) and the subjective color-mixing index and objective color-mixing ratio for the gum wafer (SCMI-W, OCMR-W) were evaluated by two independent examiners and, on a different day, re-evaluated by one of the examiners. The SCMI-B and SCMI-W assessments had inter- and intra-examiner reliable agreement at 20 or more chewing strokes. The OCMR-W measurement demonstrated high accuracy and low reproducibility between and within the examiners. There were significant gender differences in the distribution of SCMI-W scores (P = 0.044) and in the mean OCMI-W (P = 0.007). The SCMI-B and SCMI-W assessments and the OCMR-W measurement were reliable and valid at the 20 and 30 chewing strokes in this two-colored chewing gum test. The subjective color-mixing index (SCMI-W) and objective color-mixing ratio (OCMR-W) for the chewing gum wafer are capable of discriminating masticatory performance between sexes in this two-colored chewing gum test and that the OCMR-W measurement is discriminating better than the SCMI-W assessment. PMID:23076496

Endo, Toshiya; Komatsuzaki, Akira; Kurokawa, Hiroomi; Tanaka, Satoshi; Kobayashi, Yoshiki; Kojima, Koji

2014-01-01

272

Effect of molecular configuration of Xanthan gum drage reduction  

NASA Astrophysics Data System (ADS)

Drag reduction in turbulent pipe flow has been studied using dilute xanthan gum solutions. The primary goal of the studies was torelate the molecular configuration of xanthan in solutions of varying ionic strength to its effectiveness as a drag reducer. Xanthan solutions of various concentrations (10-250 wppm) in glycerine/water (12.5/87.5) and with 0.5%NaCl, added were studied over a wide Reynolds number range (1000< Re<2×104). A Rheometrics Fluids Rheometer was used to characterize the solutions in steady shear and to perform transient start-up experiments. The steady shear viscosity and transient shear stress overshoot are both significantly reduced with the addition of salt to the solution, indicating that the xanthan configuration is altered. The form of the drag reduction is similar to that which is expected for an extended molecule in dilute solution. For a given xanthan concentration, the drag reduction at high Reynolds numbers is also much lower in salt solution. Combining a knowledge of the molecular structure of xanthan and the results of recent analytical studies by several research groups, with the rheological data of this study, it is possible to speculate as to the configuration change which occurs with the addition of salt and to relate that to its effect on drag reduction. With this information, some insight into the mechanisms for drag reduction in semi-rigid polymer systems is obtained.

Rochefort, Skip; Middleman, Stanley

1986-01-01

273

An evaluation of sodium bicarbonate chewing gum as a supplement to toothbrushing for removal of dental plaque from children's teeth.  

PubMed

The purpose of this human clinical study was to determine whether a commercial chewing gum containing 5% sodium bicarbonate (ARM & HAMMER DENTAL CARE The Baking Soda Gum [AHDC]) was effective in removing dental plaque when used as a supplement to regular toothbrushing by children. Healthy children (N = 28, average age = 11 years) were randomly distributed into 2 groups. One group was instructed to chew 2 tablets of AHDC chewing gum for 20 minutes 2 times each day (after lunch and dinner) in addition to their normal toothbrushing regimen. The other group used a sugarless mint tablet twice daily during the same period in addition to toothbrushing. After 1 week of using their assigned product, all participants were again examined for oral health and plaque. After a 1-week washout period, subjects were crossed over to the opposite group. Among the 21 participants completing the study, the AHDC chewing gum significantly (P < .0001) reduced plaque by 15% after 1 week compared to the mint tablet control, as measured by the Modified Quigley-Hein Plaque Index. When longitudinally compared to the baseline plaque scores, the gum resulted in a significant (P < .01) 10% reduction of plaque on the teeth. Subanalysis of the data showed that the AHDC chewing gum was particularly effective on the lingual surfaces and the posterior teeth and least effective on the facial surfaces of the anterior teeth, which do not readily come into direct contact with the gum during mastication. The bicarbonate gum demonstrated significant plaque reduction in all other areas of the mouth, even on tooth surfaces not directly contacted during chewing. Compliance with the chewing gum regimen was excellent, and oral health exams did not indicate any adverse events among children using either the chewing gum or mint tablets. In this study, regular use of AHDC chewing gum was safe and effective in removing dental plaque and served as a significant complement to the daily toothbrushing regimen of children. PMID:11913309

Kleber, C J; Davidson, K R; Rhoades, M L

2001-07-01

274

Green stabilization of microscale iron particles using guar gum: bulk rheology, sedimentation rate and enzymatic degradation.  

PubMed

Guar gum can be used to effectively improve stability and mobility of microscale zerovalent iron particles (MZVI) used in groundwater remediation. Guar gum is a food-grade, environment friendly natural polysaccharide, which is often used as thickening agent in a broad range of food, pharmaceutical and industrial applications. Guar gum solutions are non-Newtonian, shear thinning fluids, characterized by high viscosity in static conditions and low viscosity in dynamic conditions. In particular, the high zero shear viscosity guarantees the MZVI dispersion stability, reducing the sedimentation rate of the particles thus enabling its storage and field operations. In this work, a comprehensive rheological characterization of guar gum-based slurries of MZVI particles is provided. First, we derived a model to link the bulk shear viscosity to the concentration of guar gum and then we applied it for the derivation of a modified Stokes law for the prediction of the sedimentation rate of the iron particles. The influence of the preparation procedure (cold or hot dissolution and high shear processing) on the viscosity and on the stability of the suspensions was then assessed. Finally, the dosage and concentration of enzymes - an environment friendly breaker--were studied for enhancing and controlling the degradation kinetics of the suspensions. The derived empirical relationships can be used for the implementation of an iron slurry flow and transport model and for the design of full scale injection interventions. PMID:24594029

Gastone, Francesca; Tosco, Tiziana; Sethi, Rajandrea

2014-05-01

275

Chemical and Physical Properties, Safety and Application of Partially Hydrolized Guar Gum as Dietary Fiber  

PubMed Central

The ideal water-soluble dietary fiber for the fiber-enrichment of foods must be very low in viscosity, tasteless, odorless, and should produce clear solutions in beverages. Partially hydrolyzed guar gum (PHGG) produced from guar gum by enzymatic process has the same chemical structure with intact guar gum but less than one-tenth the original molecular length of guar gum, which make available to be used as film former, foam stabilizer and swelling agent. The viscosity of PHGG is about 10 mPa·s in 5% aqueous solution, whereas 1% solution of guar gum shows range from 2,000 to 3,000 mPa·s. In addition, PHGG is greatly stable against low pH, heat, acid and digestive enzyme. For these reasons, PHGG seems to be one of the most beneficial dietary fiber materials. It also showed that interesting physiological functions still fully exert the nutritional function of a dietary fiber. PHGG has, therefore, been used primarily for a nutritional purpose and became fully integrated food material without altering the rheology, taste, texture and color of final products. PHGG named as Benefiber® in USA has self-affirmation on GRAS status of standard grade PHGG. PHGG named as Sunfiber® is now being used in various beverages, food products and medicinal foods as a safe, natural and functional dietary fiber in all over the world. PMID:18231623

Yoon, Seon-Joo; Chu, Djong-Chi; Raj Juneja, Lekh

2008-01-01

276

Optimization of enzymatic hydrolysis of guar gum using response surface methodology.  

PubMed

Guar gum is a polysaccharide obtained from guar seed endosperm portion. Enzymatically hydrolyzed guar gum is low in viscosity and has several health benefits as dietary fiber. In this study, response surface methodology was used to determine the optimum conditions for hydrolysis that give minimum viscosity of guar gum. Central composite was employed to investigate the effects of pH (3-7), temperature (20-60 °C), reaction time (1-5 h) and cellulase concentration (0.25-1.25 mg/g) on viscosity during enzymatic hydrolysis of guar (Cyamopsis tetragonolobus) gum. A second order polynomial model was developed for viscosity using regression analysis. Results revealed statistical significance of model as evidenced from high value of coefficient of determination (R(2)?=?0.9472) and P?gum as potential source of soluble dietary fiber for human health benefits. PMID:25114354

Mudgil, Deepak; Barak, Sheweta; Khatkar, B S

2014-08-01

277

Moisture Retention and Consumer Acceptability of Chocolate Bar Cookies Prepared With Okra Gum as a Fat Ingredient Substitute  

Microsoft Academic Search

Low dietary fat intake may reduce the risk of developing atherosclerosis. This study determined the feasibility of using okra gum as a fat replacer in chocolate bar cookies. Fat-free cookies were prepared with okra gum (OK) or applesauce (AP), replacing margarine and egg yolk in high-fat cookies (CTL). The moisture content of cookies was determined by using a drying oven.

JOELLE E ROMANCHIK-CERPOVICZ; RANELDA W TILMON; KAREN A BALDREE

2002-01-01

278

Influence of Phosphorus Application on Water Relations, Biochemical Parameters and Gum Content in Cluster Bean Under Water Deficit  

Microsoft Academic Search

Relative water content (RWC), leaf water potential (?w) and osmotic potential (?s), contents of chlorophyll (Chl) a, Chl b, soluble sugars, and seed quality (gum content) were used to evaluate the role of phosphorus in alleviation of the deleterious effect of water deficit in clusterbean (Cyamopsis tetragonoloba L. Taub). Under water stress, ?w, ?s, and Chl and gum contents decreased

Shubhra; J. Dayal; C. L. Goswami; R. Munjal

2004-01-01

279

Preparation and in vitro evaluation of guar gum based triple-layer matrix tablet of diclofenac sodium.  

PubMed

The objective of the present study was to design an oral controlled drug delivery system for sparingly soluble diclofenac sodium (DCL) using guar gum as triple-layer matrix tablets. Matrix tablet granules containing 30% (D1), 40% (D2) or 50% (D3) of guar gum were prepared by the conventional wet granulation technique. Matrix tablets of diclofenac sodium were prepared by compressing three layers one by one. Centre layer of sandwich like structure was incorporated with matrix granules containing DCL which was covered on either side by guar gum granule layers containing either 70, 80 or 87% of guar gum as release retardant layers. The tablets were evaluated for hardness, thickness, drug content, and drug release studies. To ascertain the kinetics of drug release, the dissolution profiles were fitted to various mathematical models. The in vitro drug release from proposed system was best explained by the Hopfenberg model indicating that the release of drug from tablets displayed heterogeneous erosion. D3G3, containing 87% of guar gum in guar gum layers and 50% of guar gum in DCL matrix granule layer was found to provide the release rate for prolonged period of time. The results clearly indicate that guar gum could be a potential hydrophilic carrier in the development of oral controlled drug delivery systems. PMID:23181081

Chavda, H V; Patel, M S; Patel, C N

2012-01-01

280

Changes in electrical energy requirements to operate an ice cream freezer as a function of sweeteners and gums  

Microsoft Academic Search

Changes in electrical energy required to operate a continuous freezer were monitored for various ice cream formulae. Ice cream formulae consisted of nine different combinations of sucrose, 36 DE corn syrup, and 42 high fructose corn syrup as well as two ratios of guar gum to locust bean gum. Within the same sweetening system, a mix high in locust bean

D. E. Smith; A. S. Bakshi; S. A. Gay

1985-01-01

281

Psychological and Pharmacological Influences in Cigarette Smoking Withdrawal: Effects of Nicotine Gum and Expectancy on Smoking Withdrawal Symptoms and Relapse  

Microsoft Academic Search

To determine the relative effects of expectancy and nicotine depletion on aversive withdrawal symptoms, we gave 109 smokers attempting to quit either nicotine gum or placebo within a balanced placebo design and monitored their withdrawal symptoms and smoking for 2 weeks. Subjects who believed they were getting nicotine gum reported less physical symptoms of withdrawal, showed less arousal, and smoked

Andrew M. Gottlieb; Joel D. Killen; G. Alan Marlatt; C. Barr Taylor

1987-01-01

282

Psychological and Pharmacological Influences in Cigarette Smoking Withdrawal : Effects of Nicotine Gum and Expectancy on Smoking Withdrawal Symptoms and Relapse  

Microsoft Academic Search

To determine the relative effects of expectancy and nicotine depletion on aversive withdrawal symp- toms, we gave 109 smokers attempting to quit either nicotine gum or placebo within a balanced placebo design and monitored their withdrawal symptoms and smoking for 2 weeks . Subjects who believed they were getting nicotine gum reported less physical symptoms of withdrawal, showed less arousal,

G. Alan; Marlatt C; Barr Taylor

283

The rate of absorption and relative bioavailability of caffeine administered in chewing gum versus capsules to normal healthy volunteers  

Microsoft Academic Search

Objectie:The purpose of this study was to evaluate the rate of absorption and relative bioavailability of caffeine from a Stay Alert ® chewing gum and capsule formulation. Methods: This was a double blind, parallel, randomized, seven treatment study. The treatment groups were: 50, 100, and 200 mg gum, 50, 100, and 200 mg capsule, and a placebo. Subjects consisted of

Gary H. Kamimori; Chetan S. Karyekar; Ronald Otterstetter; Donna S. Cox; Thomas J. Balkin; Gregory L. Belenky; Natalie D. Eddington

2002-01-01

284

Productivity improvement in xanthan gum fermentation using multiple substrate optimization.  

PubMed

A novel and more comprehensive formulation of the optimal control problem that reflects the operational requirements of a typical industrial fermentation has been proposed in this work. This formulation has been applied to a fed-batch bioreactor with three control variables, i.e., feed rates of carbon source, nitrogen source, and an oxygen source, to result in a 148.7% increase in product formation. Xanthan gum production using Xanthomonas campestris has been used as the model system for this optimization study, and the liquid-phase oxygen supply strategy has been used to supply oxygen to the fermentation. The formulated optimization problem has several constraints associated with it due to the nature of the system. A robust stochastic technique, differential evolution, has been used to solve this challenging optimization problem. The infinite dimensional optimization problem has been approximated to a finite dimensional one by control vector parametrization. The state constraints that are path constraints have been addressed by using penalty functions and by integrating them over the total duration to ensure a feasible solution. End point constraints on final working volume of the reactor and on the final residual concentrations of carbon and nitrogen sources have been included in the problem formulation. Further, the toxicity of the oxygen source, H(2)O(2), has been addressed by imposing a constraint on its maximum usable concentration. In addition, the initial volume of the bioreactor contents and feed concentrations have been handled as decision variables, which has enabled a well-grounded choice for their values from the optimization procedure; adhoc values are normally used in the industry. All results obtained by simulation have been validated experimentally with good agreements between experimental and simulated values. PMID:12892481

Chaitali, Mandal; Kapadi, Mangesh; Suraishkumar, G K; Gudi, R D

2003-01-01

285

Properties of Whole Saliva and Dental Plaque in Relation to 40Month Consumption of Chewing Gums Containing Xylitol, Sorbitol or Sucrose  

Microsoft Academic Search

Samples of whole saliva and dental plaque were collected from initially 10-year old subjects who participated in a 40-month cohort study investigating the effect of chewing gum usage on caries rates. The subjects represented nine cohorts of which one did not receive gum, while in eight cohorts the subjects received gum containing either xylitol, sorbitol, their mixtures, or sucrose as

K. K. Mäkinen; C.-Y. Chen; P.-L. Mäkinen; C. A. Bennett; P. J. Isokangas; K. P. Isotupa

1996-01-01

286

Peach gum polysaccharide polyelectrolyte: preparation, properties and application in layer-by-layer self-assembly.  

PubMed

The hydrolyzed peach gum polysaccharide (HPGP) prepared at acidic condition is investigated as an anionic polyelectrolyte for the first time. A hydrolysis mechanism is proposed by monitoring the hydrolysis efficiency and morphological change of crude peach gum, and the intrinsic viscosity of resulted HPGP as a function of hydrolysis time. Fourier transform infrared (FTIR) spectroscopy and ?-potential measurements reveal that HPGP with multiple carboxylic groups is negatively charged in water in the pH range 3-11. The HPGP exhibits remarkable pH and ionic strength responsiveness, as proven by dynamic light scattering (DLS) and atomic force microscopy (AFM) measurements. Moreover, the layer-by-layer (LbL) self-assembly experiments further confirmed that the HPGP can be utilized as an anionic polyelectrolyte. Considering the facile availability, favorable compatibility and intriguing functionality of HPGP, this study opens up enormous opportunities for the large-scale utilization of peach gum resource. PMID:25256497

Huang, Jiachang; Zhou, Li

2014-11-26

287

Discovery of X-ray emission associated with the Gum Nebula  

NASA Technical Reports Server (NTRS)

The Gum Nebula was observed by the A-2 LED proportional counters on the HEAO-1 satellite as part of the all-sky survey. The first detection of X-ray emission associated with the Gum Nebula is reported. Soft X-ray spectra were constructed from the A-2 LED PHA data. Single temperature Raymond-Smith models were fitted to the observed spectra to yield temperature, column density and emission measure. The temperature is 6 x 10 exp 5 K, the column density 4 x 10 exp 20/sq cm, and the emission measure 5 cm exp-6 pc. The X-ray and optical properties of the Gum Nebula are consistent with a supernova remnant in the shell stage of evolution, which was the product of an energetic (3 x 10 exp 51 ergs) supernova explosion which occurred about 2 x 10 exp 6 yr ago.

Leahy, D. A.; Nousek, J.; Garmire, G.

1992-01-01

288

Dose response of xylitol and sorbitol for EPR retrospective dosimetry with applications to chewing gum.  

PubMed

The purpose of this investigation was to study the radiation-induced electron paramagnetic resonance signal in sweeteners xylitol and sorbitol for use in retrospective dosimetry. For both sweeteners and chewing gum, the signal changed at an interval of 1-84 d after irradiation with minimal changes after 4-8 d. A dependence on storage conditions was noticed and the exposure of the samples to light and humidity was therefore minimised. Both the xylitol and sorbitol signals showed linearity with dose in the measured dose interval, 0-20 Gy. The dose-response measurements for the chewing gum resulted in a decision threshold of 0.38 Gy and a detection limit of 0.78 Gy. A blind test illustrated the possibility of using chewing gums as a retrospective dosemeter with an uncertainty in the dose determination of 0.17 Gy (1 SD). PMID:22908355

Israelsson, A; Gustafsson, H; Lund, E

2013-04-01

289

Natural gums as sustained release carriers: development of gastroretentive drug delivery system of ziprasidone HCl  

PubMed Central

Background Objective of this study is to show the potential use of natural gums in the development of drug delivery systems. Therefore in this work gastro retentive tablet formulations of ziprasidone HCl were developed using simplex lattice design considering concentration of okra gum, locust bean gum and HPMC K4M as independent variables. A response surface plot and multiple regression equations were used to evaluate the effect of independent variables on hardness, flag time, floating time and drug release for 1 h, 2 h, and 8 h and for 24 h. A checkpoint batch was also prepared by considering the constraints and desirability of optimized formulation to improve its in vitro performance. Significance of result was analyzed using ANOVA and p < 0.05 was considered statistically significant. Results Formulation chiefly contains locust bean gum found to be favorable for hardness and floatability but combined effect of three variables was responsible for the sustained release of drug. The in vitro drug release data of check point batch (F8) was found to be sustained well compared to the most satisfactory formulation (F7) of 7 runs. The ‘n’ value was found to be between 0.5 and 1 suggesting that release of drug follows anomalous (non-fickian) diffusion mechanism indicating both diffusion and erosion mechanism from these natural gums. Predicted results were almost similar to the observed experimental values indicating the accuracy of the design. In vivo floatability test indicated non adherence to the gastric mucosa and tablets remain buoyant for more than 24 h. Conclusions Study showed these eco-friendly natural gums can be considered as promising SR polymers. PMID:23352292

2012-01-01

290

Inhibition of a model protease--pyroglutamate aminopeptidase by a natural oligosaccharide gum from Hakea gibbosa.  

PubMed

The purpose of this study was to investigate the effect of the oligosaccharide gum from Hakea gibbosa on the activity of a model protease enzyme pyroglutamate aminopeptidase (5-oxoprolyl peptidase; EC 3.4.19.3) and to elucidate the mechanism responsible for the decreased activity. Enzyme kinetic studies were conducted at 37 degrees C in 100 mM potassium phosphate buffer with 10 mM EDTA, 5% (v/v) glycerol, and 5 mM DTT (pH 8) for 15 min and were performed both in the presence and absence of the gum. Enzymatic activity was determined by a colorimetric assay using the specific substrate L-pyroglutamic acid beta-napthylamide. The enzyme kinetics was studied at various substrate and gum concentrations. The velocity of the reaction was determined by the amount of the product (beta-napthylamine) liberated at each substrate and gum concentration. The Ks and Vmax of the enzyme in the absence of the gum were 24.40+/-2.14 microM and 502.95+/-28.90 nmoles x min(-1) x mg protein(-1), respectively. As the concentration of the gum was gradually increased from 0.1 to 2%, the value of the Vmax decreased from 318.94+/-21.46 to 158.83+/-24.51 nmoles x min(-1) x mg protein(-1) while Ks increased from 17.42+/-4.6 to 63.03+/-1.89 microM. The mechanism for the inhibition of the enzyme by Hakea appeared to be a mixed-linear type (a type of non-competitive inhibition) as suggested from Hanes-Woolf, Dixon and Cornish-Bowden plots. The turnover number, kcat, calculated for the enzyme also decreased from 14.09+/-0.81 to 4.45+/-0.69 min(-1) as the concentration of the inhibitor was incrementally increased from 0 to 2% (w/v). The K(i) and alphaK(i) calculated from Dixon and Cornish-Bowden plots were found to be 0.31+/-0.11% (w/v) and 1.33+/-0.42% (w/v), respectively. The natural gum from Hakea gibbosa was effective in non-competitively inhibiting the enzyme pyroglutamate aminopeptidase. Thus, the natural gum may be a promising additive not only for its sustained-release and mucoadhesive properties as shown previously, but also for its ability to slow the enzymatic degradation of therapeutic polypeptides incorporated in dosage forms. PMID:11165074

Alur, H H; Desai, R P; Mitra, A K; Johnston, T P

2001-01-16

291

Development and Antibacterial Activity of Cashew Gum-Based Silver Nanoparticles  

PubMed Central

The present study describes the development of a green synthesis of silver nanoparticles reduced and stabilized by exuded gum from Anacardium occidentale L. and evaluates in vitro their antibacterial and cytotoxic activities. Characterization of cashew gum-based silver nanoparticles (AgNPs) was carried out based on UV–Vis spectroscopy, transmission electron microscopy and dynamic light scattering analysis which revealed that the synthesized silver nanoparticles were spherical in shape, measuring about 4 nm in size with a uniform dispersal. AgNPs presented antibacterial activity, especially against Gram-negative bacteria, in concentrations where no significant cytotoxicity was observed. PMID:23455467

Quelemes, Patrick V.; Araruna, Felipe B.; de Faria, Bruna E. F.; Kuckelhaus, Selma A. S.; da Silva, Durcilene A.; Mendonça, Ronaldo Z.; Eiras, Carla; dos S. Soares, Maria José; Leite, José Roberto S. A.

2013-01-01

292

Design of sterculia gum based double potential antidiarrheal drug delivery system.  

PubMed

In view of the antidiarrheal properties of sterculia gum and ornidazole, an attempt has been made to synthesize novel hydrogels by functionalization of sterculia gum with poly(vinylpyrrolidone) (PVP) for release of the model antidiarrheal drug ornidazole. These hydrogels were characterized with FTIR, SEM, TGA and swelling behavior. Swelling kinetics of the hydrogels and in vitro release dynamics of ornidazole from the drug loaded hydrogels have been studied to determine the mechanism of swelling and drug release from the drug loaded hydrogels. A Fickian diffusion mechanism has been observed for the release of drug from the hydrogels. These hydrogels may have dual actions for the treatment of diarrhea. PMID:20889316

Singh, Baljit; Sharma, Nisha

2011-02-01

293

The deformation of gum metal under nanoindentation and sub-micron pillar compression  

NASA Astrophysics Data System (ADS)

Reaching ideal strength has proven to be difficult in most materials. Dislocation slip, phase transformations, twinning, and fracture all tend to occur at stresses well below the ideal strength of a material. Only on very small scales has it been possible to approach ideal strength. Thus, it was of great interest when a set of beta-Ti alloys, Gum Metal, were found to have a bulk yield strength close to half of its ideal strength. However, some recent studies have questioned the reliability of this claim. Several studies have suggested Gum Metal deforms by dislocation slip. Others have suggested the possibility of transformation-induced plasticity. The present study was undertaken in order to help clarify if and how Gum Metal can reach ideal strength. Two different experiments, ex situ nanoindentation and quantitative in situ nanopillar compression in a transmission electron microscope to correlate real-time deformation behavior, were performed on a single composition of Gum Metal, Ti-23Nb-0.7Ta-2Zr-1.20 at. %, obtained from Toyota Central R&D Laboratories. Nanoindented specimens were thinned from the bottom surface until the pits of multiple indentations became electron-transparent allowing for qualitative analysis of the deformation microstructure in both fully cold-worked and solution-treated specimens. Real-time load-displacement behavior from the nanopillar compression tests was correlated with real-time video recorded during each compression to determine both the compressive strength of each pillar and the timing and strengths of different deformation behaviors observed. Combining the results from both experiments provided several important conclusions. First, Gum Metal approaches and can attain ideal strength in nanopillars regardless of processing condition. While dislocations exist in Gum Metal, they can be tightly pinned by obstacles with spacing less than ˜20 nm, which should inhibit their motion at strengths below the ideal shear strength. The plastic deformation of Gum Metal is not controlled by giant faults or by stress-induced phase transformations. Both of these phenomena, while active, are not the source of plasticity in Gum Metal.

Withey, Elizabeth Ann

294

Anti-inflammatory activity of Chios mastic gum is associated with inhibition of TNF-alpha induced oxidative stress  

PubMed Central

Background Gum of Chios mastic (Pistacia lentiscus var. chia) is a natural antimicrobial agent that has found extensive use in pharmaceutical products and as a nutritional supplement. The molecular mechanisms of its anti-inflammatory activity, however, are not clear. In this work, the potential role of antioxidant activity of Chios mastic gum has been evaluated. Methods Scavenging of superoxide radical was investigated by electron spin resonance and spin trapping technique using EMPO spin trap in xanthine oxidase system. Superoxide production in endothelial and smooth muscle cells stimulated with TNF-? or angiotensin II and treated with vehicle (DMSO) or mastic gum (0.1-10 ?g/ml) was measured by DHE and HPLC. Cellular H2O2 was measured by Amplex Red. Inhibition of protein kinase C (PKC) with mastic gum was determined by the decrease of purified PKC activity, by inhibition of PKC activity in cellular homogenate and by attenuation of superoxide production in cells treated with PKC activator phorbol 12-myristate 13-acetate (PMA). Results Spin trapping study did not show significant scavenging of superoxide by mastic gum itself. However, mastic gum inhibited cellular production of superoxide and H2O2 in dose dependent manner in TNF-? treated rat aortic smooth muscle cells but did not affect unstimulated cells. TNF-? significantly increased the cellular superoxide production by NADPH oxidase, while mastic gum completely abolished this stimulation. Mastic gum inhibited the activity of purified PKC, decreased PKC activity in cell homogenate, and attenuated superoxide production in cells stimulated with PKC activator PMA and PKC-dependent angiotensin II in endothelial cells. Conclusion We suggest that mastic gum inhibits PKC which attenuates production of superoxide and H2O2 by NADPH oxidases. This antioxidant property may have direct implication to the anti-inflammatory activity of the Chios mastic gum. PMID:21645369

2011-01-01

295

The environs of the H II region Gum 31  

NASA Astrophysics Data System (ADS)

Aims:We analyze the distribution of the interstellar matter in the environs of the H ii region Gum 31, excited by the open cluster NGC 3324, located in the complex Carina region, with the aim of investigating the action of the massive stars on the surrounding neutral material. Methods: We use neutral hydrogen 21-cm line data, radio continuum images at 0.843, 2.4 and 4.9 GHz, 12CO(1-0) observations, and IRAS and MSX infrared data. Results: Adopting a distance of 3 kpc for the H ii region and the ionizing cluster, we derived an electron density of 33±3 cm-3 and an ionized mass of (3.3±1.1)×103 M? based on the radio continuum data at 4.9 GHz. The H i 21-cm line images revealed an H i shell surrounding the H ii region. The H i structure is 10.0 ± 1.7 pc in radius, has a neutral mass of 1500 ± 500 M?, and is expanding at 11 km s-1. The associated molecular gas amounts to (1.1 ± 0.5)×105 M?, being its volume density of about 350 cm-3. This molecular shell could represent the remains of the cloud where the young open cluster NGC 3324 was born or could have originated by the shock front associated with the H ii region. The difference between the ambient density and the electron density of the H ii region suggests that the H ii region is expanding. The distributions of the ionized and molecular material, along with that of the emission in the MSX band A, suggest that a photodissociation region has developed at the interface between the ionized and molecular gas. The copious UV photon flux from the early type stars in NGC 3324 keeps the H ii region ionized. The characteristics of a relatively large number of the IRAS, MSX, and 2MASS point sources projected onto the molecular envelope are compatible with protostellar candidates, showing the presence of active star forming regions. Very probably, the expansion of the H ii region has triggered stellar formation in the molecular shell.

Cappa, C.; Niemela, V. S.; Amorín, R.; Vasquez, J.

2008-01-01

296

Chemical composition and rheology of low-fat Iranian white cheese incorporated with guar gum and gum arabic as fat replacers.  

PubMed

The effects of incorporating guar gum (GG) and gum arabic (GA) in cheese-making milk with various fat contents (0.4, 0.9, and 1.4 %) on chemical and rheological properties of Iranian white cheese were evaluated by response surface method (RSM). As GG concentration increased, dry matter content of cheese samples decreased due to the high water binding capacity of this gum. A similar trend was also observed for GA at concentrations less than 150 ppm. The higher the GG concentration, the higher was the free fatty acid content of cheese samples. GA at concentrations more than 150 ppm, increased the storage modulus (G'), causing an undesirable hard texture for the product. The G' and stress at fracture (?f) of samples decreased by the increasing concentration of GG incorporated into the cheese-making milk. Response surface minimization of rheological indices for Iranian white cheese showed that combination of two hydrocolloids (GG in the concentration range 75-170 ppm and GA at concentrations <75 ppm) would provide the softest texture. PMID:25328199

Lashkari, Hannan; Khosrowshahi Asl, Asghar; Madadlou, Ashkan; Alizadeh, Mohammad

2014-10-01

297

Effectiveness of almond gum trees exudate as a novel edible coating for improving postharvest quality of tomato (Solanum lycopersicum L.) fruits.  

PubMed

The use of coatings is a technique used to increase postharvest life of the fruit. Almond gum exudate was used, in comparison with gum arabic, at concentrations of 10% as a novel edible coating, to preserve the quality parameters of tomato (Solanumlycopersicum). Fruits were harvested at the mature-green stage of ripening. Results showed that the coatings delayed significantly (p?gum and gum arabic coatings to maintain the overall quality of tomato fruits during storage period (20 days). In addition, the difference between gum arabic and almond gum coatings was not significant (p?>?0.05) except for pulp color. Therefore, we can suggest the use of almond gum exudate as a novel edible coating extends the shelf-life of tomato fruits on postharvest. PMID:23733822

Mahfoudhi, Nesrine; Chouaibi, Moncef; Hamdi, Salem

2014-01-01

298

A review of recent developments on the regulatory, structural and functional aspects of gum arabic  

Microsoft Academic Search

There have been substantial developments recently concerning the regulatory aspects of gum arable and the elucidation of its structure and functional characteristics. The aim of this paper is to present the position with regard to its current legal definition, to summarize what is now known about the structure of this complex polysaccharide and to illustrate how the structural features relate

A. M. Islam; G. O. Phillips; A. Sljivo; M. J. Snowden; P. A. Williams

1997-01-01

299

Colon Targeted Guar Gum Compression Coated Tablets of Flurbiprofen: Formulation, Development, and Pharmacokinetics  

PubMed Central

The rationale of the present study is to formulate flurbiprofen colon targeted compression coated tablets using guar gum to improve the therapeutic efficacy by increasing drug levels in colon, and also to reduce the side effects in upper gastrointestinal tract. Direct compression method was used to prepare flurbiprofen core tablets, and they were compression coated with guar gum. Then the tablets were optimized with the support of in vitro dissolution studies, and further it was proved by pharmacokinetic studies. The optimized formulation (F4) showed almost complete drug release in the colon (99.86%) within 24?h without drug loss in the initial lag period of 5?h (only 6.84% drug release was observed during this period). The pharmacokinetic estimations proved the capability of guar gum compression coated tablets to achieve colon targeting. The Cmax of colon targeted tablets was 11956.15?ng/mL at Tmax of 10?h whereas it was 15677.52?ng/mL at 3?h in case of immediate release tablets. The area under the curve for the immediate release and compression coated tablets was 40385.78 and 78214.50?ng-h/mL and the mean resident time was 3.49 and 10.78?h, respectively. In conclusion, formulation of guar gum compression coated tablets was appropriate for colon targeting of flurbiprofen. PMID:24260738

Bontha, Vijaya Kumar

2013-01-01

300

Biobased adhesives, gums, emulsions, and binders: current trends and future prospects  

Microsoft Academic Search

Biopolymers derived from renewable resources are an emerging class of advanced materials that offer many useful properties for a wide range of food and nonfood applications. Current state of the art in research and development of renewable polymers as adhesives, gums, binders, and emulsions is the subject of this review. Much of the focus will be on major biopolymers such

Syed H. Imam; Cristina Bilbao-Sainz; Bor-Sen Chiou; Gregory M. Glenn; William J. Orts

2012-01-01

301

Oil-entrapped sterculia gum-alginate buoyant systems of aceclofenac: development and in vitro evaluation.  

PubMed

The current investigation deals with the development and optimization of oil-entrapped sterculia gum-alginate buoyant beads containing aceclofenac by ionotropic emulsion-gelation technique using 3(2) factorial design. The effect of polymer to drug ratio and sodium alginate to sterculia gum ratio on the drug entrapment efficiency (%), and cumulative drug release after 7 h (%) was optimized. The optimized oil-entrapped sterculia gum-alginate buoyant beads containing aceclofenac (F-O) showed drug entrapment efficiency of 90.92±2.34%, cumulative drug release of 41.65±3.97% after 7 h in simulated gastric fluid (pH 1.2), and well buoyancy over 8 h in simulated gastric fluid (pH 1.2) with 5.20 min buoyant lag-time. The in vitro drug release from these buoyant beads followed Korsmeyer-Peppas model (R(2)=0.9866-0.9995) with anomalous (non-Fickian) diffusion drug release mechanism. These new sterculia gum-alginate buoyant beads containing aceclofenac were also characterized using SEM, FTIR, and P-XRD analysis. PMID:23334180

Guru, Pravat Ranjan; Nayak, Amit Kumar; Sahu, Rajendra Kumar

2013-04-01

302

Preparation and characterization of cross-linked guar gum microspheres: optimization using factorial design.  

PubMed

In the present work cross-linked guar gum microspheres were prepared for colon specific delivery of ornidazole. Development and optimization of guar gum microspheres for colonic drug delivery was carried out using a 2(4) factorial design based on four independent variables. Microspheres were prepared by emulsification method using glutaraldehyde as cross-linking agent. Morphology and surface characteristics of the formulations were determined by scanning electron microscopy. Particle size of the guar gum microspheres was determined by particle size analyzer. In vitro drug-release studies were performed in conditions simulating stomach-to-colon transit in the presence and absence of rat cecal contents. Only a small fraction of drug was released at acidic pH; however, the release of drug was found to be higher in the presence of rat cecal contents, indicating the susceptibility of guar gum matrix to colonic enzymes released from rat cecal contents. The significance of differences was evaluated by analysis of variance (ANOVA). Differences were considered statistically significant at p<0.05. PMID:21297297

Kumar, Shukla Raj; Piyush, Trivedi; Suman, Ramteke; Akanksha, Tiwari

2011-01-01

303

Nanodisturbances in deformed Gum Metal Mikhail Yu. Gutkin a,*, Toshitaka Ishizaki b  

E-print Network

alloy with high strength, low Young's modulus, excellent cold workability and low resistance to shear Young's modulus and excellent cold workability [1,2]. This alloy, Gum Metal, is composed of group Va is its excellent cold workability. The alloy shows much less work hardening than ordinary metals even up

Ovid'ko Ilya A.

304

Gum arabic as a potential corrosion inhibitor for aluminium in alkaline medium and its adsorption characteristics  

Microsoft Academic Search

Purpose – To investigate the inhibitive effect of gum arabic (GA) for the corrosion of aluminium in alkaline (NaOH) medium and determine its adsorption characteristics. The present work is another trial to find a cheap and environmentally safe inhibitor for aluminium corrosion. Design\\/methodology\\/approach – The inhibition efficiency (%I) has been evaluated using the hydrogen evolution (via the gasometric assembly) and

S. A. Umoren; I. B. Obot; E. E. Ebenso; P. C. Okafor; O. Ogbobe; E. E. Oguzie

2006-01-01

305

In vitro retardation of glucose diffusion with gum extracted from malva nut seeds produced in Thailand  

Microsoft Academic Search

Mucilage of malva nut fruit has been used as traditional medicine in Thailand. Our laboratory has succeeded in extracting malva nut gum (MNG) from malva nut seeds by using alkaline-extraction method. The extract had higher gelling properties compared to water-extracted MNG. This research was aimed to investigate the effect of MNG on the retardation of glucose diffusion in in vitro

Anchalee Srichamroen; Visith Chavasit

2011-01-01

306

Effectiveness of a GUM-Compliant Course for Teaching Measurement in the Introductory Physics Laboratory  

ERIC Educational Resources Information Center

An evaluation of a course aimed at developing university students' understanding of the nature of scientific measurement and uncertainty is described. The course materials follow the framework for metrology as recommended in the "Guide to the Expression of Uncertainty in Measurement" (GUM). The evaluation of the course is based on responses to…

Pillay, Seshini; Buffler, Andy; Lubben, Fred; Allie, Saalih

2008-01-01

307

Dielectric and Thermal Properties of Rice Cake Formulations Containing Different Gums Types  

Microsoft Academic Search

In this study, dielectric properties of rice cake formulations containing different gum types (xanthan, guar, locust bean, HPMC, and kappa-carrageenan) were determined at temperatures between 25 and 90°C at 2450 MHz. Moreover, thermal properties of these formulations were determined by using differential scanning calorimeter (DSC). Dielectric properties of cake batters were found to be dependent on cake formulation. Xanthan and

Elif Turabi; Marc Regier; Gulum Sumnu; Serpil Sahin; Matthias Rother

2010-01-01

308

of Acacia gum polymers (GA) on both human fecal flora composition and  

E-print Network

of Acacia gum polymers (GA) on both human fecal flora composition and metabolism in vitro. Methods the changes in the digestive flora and their functional consequences. Colonic transit time was compared with fecal flora during supplementation of healthy subjects (n = 19) with Propioni- bacteria, regularly used

Paris-Sud XI, Université de

309

Gums and resins: The potential for supporting sustainable adaptation in Kenya's drylands  

Microsoft Academic Search

Frequent droughts and conflicts are key challenges faced by nomadic pastoralists in Kenya's drylands. Few options exist for alternative livelihoods. This article investigates the potential of collecting plant gums and resins for livelihood diversification and for contributing to sustainable adaptation to climate change in Kenya's drylands. Observations were made in various studies over a period of two years on dryland

FRANCIS N. GACHATHI; SIRI ERIKSEN

2011-01-01

310

Gemcitabine combined with gum mastic causes potent growth inhibition and apoptosis of pancreatic cancer cells  

PubMed Central

Aim: To investigate the antiproliferative and apoptotic effects of gemcitabine combined with gum mastic and the underlying mechanisms in human pancreatic cancer cell lines. Methods: Cell proliferation and apoptosis were examined using the methyl thiazolyl tetrazolium (MTT) assay and propidium iodine staining, respectively. The expression of Bcl-2, Bax, NF-?B p65 subunit, and I?B? protein was measured using Western blotting. Results: Gemcitabine 0.01?100 ?g/mL inhibited cell proliferation and induced apoptosis in both pancreatic cancer BxPC-3 and COLO 357 cells. Gum mastic 40 ?g/mL significantly potentiated the antiproliferative and apoptotic effects of gemcitabine 10 ?g/mL after 72-h treatment. When cells were treated with gemcitabine in combination with gum mastic, the I?B? level was increased, whereas NF-?B activation was blocked; the expression of Bax protein was substantially increased, but Bcl-2 protein was down-regulated. Conclusion: Gemcitabine combined with gum mastic causes potent apoptosis in pancreatic cancer cells. The combination may be an effective therapeutic strategy for pancreatic cancer. PMID:20523344

Huang, Xin-yu; Wang, Hong-cheng; Yuan, Zhou; Li, Ang; He, Mei-lan; Ai, Kai-xing; Zheng, Qi; Qin, Huan-long

2010-01-01

311

The effects of prolonged gum chewing on salivary flow rate and composition  

Microsoft Academic Search

Objective: To determine the effect of gum chewing for 2h on salivary flow rate and composition. Design: Five male and five females each collected whole saliva at intervals over a 2h period on three separate days, prior to which they collected unstimulated saliva for 5min. For one 2h session they continued to collect only unstimulated saliva while for the others

C Dawes; K Kubieniec

2004-01-01

312

The intra-oral distribution of unstimulated and chewing-gum-stimulated parotid saliva  

Microsoft Academic Search

The objective was to determine the percentage contribution of parotid saliva to whole saliva and to the saliva at 11 sites in the mouth, when flow rate was unstimulated or stimulated with chewing-gum. The marker substance used was a-amylase, as this is in much higher concentration in parotid saliva than in secretions from other salivary glands. Formulae were derived for

R. Sas; C. Dawes

1997-01-01

313

Chewing gum and cognitive performance: a case of a functional food with function but no food?  

Microsoft Academic Search

Recent reports suggest that enhancement of memory performance while chewing gum is a fairly robust phenomenon. The processes underlying the effect are not known, but may involve glucose delivery, context-dependent effects and arousal mechanisms amongst others. This brief commentary outlines the main findings from these studies and raises some issues regarding interpretation, methodology and future research directions.

Andrew Scholey

2004-01-01

314

"JCE" Classroom Activity #105. A Sticky Situation: Chewing Gum and Solubility  

ERIC Educational Resources Information Center

In this Activity, students perform several solubility tests using common food items such as chocolate, chewing gum, water, sugar, and oil. From their observations during the Activity, students will initially classify the substances tested as soluble or insoluble. They will then use their understanding of the chemistry of solubility to classify the…

Montes-Gonzalez, Ingrid; Cintron-Maldonado, Jose A.; Perez-Medina, Ilia E.; Montes-Berrios, Veronica; Roman-Lopez, Saurie N.

2010-01-01

315

Effect of nicotine chewing gum as an adjunct to general practitioner's advice against smoking  

Microsoft Academic Search

This study was designed to see whether the offer and prescription of nicotine chewing gum would enhance the efficacy of general practitioners' advice to stop smoking. A sample of 1938 cigarette smokers who attended the surgeries of 34 general practitioners in six group practices were assigned by week of attendance (in a balanced design) to one of three groups: (a)

M A Russell; R Merriman; J Stapleton; W Taylor

1983-01-01

316

Association between masticatory performance using a colour-changeable chewing gum and jaw movement.  

PubMed

The purpose of this study was to investigate the relationship between masticatory performance as determined using a colour-changeable chewing gum and mandibular movements. Subjects comprised 45 fully dentate adults (23 men, 22 women; mean age, 28·1 years). The gum was chewed for a specified number of chewing strokes (20, 40, 60, 80, 120 or 160 strokes) without any instructions as to chewing side. A colourimeter was used to measure L*, a* and b* values (CIE-L*a*b* colour system) for the chewed gum, then the difference between two colours in the CIE-L*a*b* colour space (?E) for each number of chewing strokes was calculated according to a formula. Index of masticatory performance (?E60) for each subject was obtained using ?E for 20, 40, 60, 80, 120 and 160 strokes. Mandibular movements were recorded using an opto-electric system with six degrees of freedom. Twelve parameters of mandibular movements relating to amplitude, duration, velocity and angle were computed for each cycle, and mean values for 10 cycles (from cycle 11 to 20) were calculated separately. Stepwise multiple regression analysis identified maximum closing velocity and closing angle as predictors accounting for 18% of the variation in ?E60. These results suggest that lower angles of approach to intercuspation and faster speed during closing duration are associated with colour changes in the colour-changeable chewing gum. PMID:21314707

Komagamine, Y; Kanazawa, M; Minakuchi, S; Uchida, T; Sasaki, Y

2011-08-01

317

Prolonged rhythmic gum chewing suppresses nociceptive response via serotonergic descending inhibitory pathway in humans  

Microsoft Academic Search

Serotonergic (5-HT) neurons are implicated in modulating nociceptive transmission. It is established that 5-HT neuronal activity is enhanced by rhythmic behaviors such as chewing and locomotion in animals. We thus hypothesized that 5-HT descending inhibitory pathways may be enhanced by rhythmic behavior of gum chewing in humans. To evaluate this idea, we examined nociceptive flexion reflex (NFR), while a subject

Yuko Mohri; Masaki Fumoto; Ikuko Sato-Suzuki; Masahiro Umino; Hideho Arita

2005-01-01

318

Nicotine chewing gum in general practice: effect of follow up appointments  

Microsoft Academic Search

Two hundred smokers who were judged by their general practitioner to be motivated to stop smoking were allocated to one of two groups. All were offered an initial appointment at which they were advised to stop smoking and offered nicotine gum. One group then received no further appointments. The other was offered four further appointments over three months. Both groups

A Marshall; M Raw

1985-01-01

319

Design and evaluation of fast dissolving tablets containing diclofenac sodium using fenugreek gum as a natural superdisintegrant  

PubMed Central

Objective To formulate diclofenac sodium as fast dissolving tablets (FDTs) using fenugreek gum as a natural superdisintegrant which also possess anti-inflammatory activity. Methods An attempt was made to extract the fenugreek gum and evaluated it for various physicochemical characterizations. The swelling index and viscosity of fenugreek gum was 221% and 293.4 mpa.s respectively. FDTs of diclofenac sodium was formulated by direct compression technique using different concentrations (1%-6%, w/w) of fenugreek gum as a natural superdisintegrant and compared with renowned synthetic superdisintegrants like sodium starch glycolate and croscarmellose sodium. The anti-inflammatory activity of a formulation was evaluated with carrageenan induced experimental rats. Results The formulated tablets were evaluated for various physical tests like weight variation, friability, hardness and results complied with the limits. The drug release from all the formulations ascertained first order kinetics. Among all the formulations F3 containing fenugreek gum with the concentration of 6% produced least disintegrating time 21 seconds resulting in higher drug release rate 93.74% at the end of 25 min. Hence, it was considered as optimized formulation. The present study revealed that the fenugreek gum as a natural superdisintegrant showed better disintegrating property than the most widely used synthetic superdisintegrants like sodium starch glycolate and croscarmellose sodium in the formulations of FDTs. Conclusions The results suggested that the fenugreek gum act as a good super disintegrating agent and it showed promising additive anti-inflammatory activity with diclofenac sodium.

Kumar, M. Uday; Babu, M. Kishore

2014-01-01

320

The use of Hibiscus esculentus (Okra) gum in sustaining the release of propranolol hydrochloride in a solid oral dosage form.  

PubMed

The effectiveness of Okra gum in sustaining the release of propranolol hydrochloride in a tablet was studied. Okra gum was extracted from the pods of Hibiscus esculentus using acetone as a drying agent. Dried Okra gum was made into powder form and its physical and chemical characteristics such as solubility, pH, moisture content, viscosity, morphology study using SEM, infrared study using FTIR, crystallinity study using XRD, and thermal study using DSC and TGA were carried out. The powder was used in the preparation of tablet using granulation and compression methods. Propranolol hydrochloride was used as a model drug and the activity of Okra gum as a binder was compared by preparing tablets using a synthetic and a semisynthetic binder which are hydroxylmethylpropyl cellulose (HPMC) and sodium alginate, respectively. Evaluation of drug release kinetics that was attained from dissolution studies showed that Okra gum retarded the release up to 24 hours and exhibited the longest release as compared to HPMC and sodium alginate. The tensile and crushing strength of tablets was also evaluated by conducting hardness and friability tests. Okra gum was observed to produce tablets with the highest hardness value and lowest friability. Hence, Okra gum was testified as an effective adjuvant to produce favourable sustained release tablets with strong tensile and crushing strength. PMID:24678512

Zaharuddin, Nurul Dhania; Noordin, Mohamed Ibrahim; Kadivar, Ali

2014-01-01

321

Synthesis, characterization and evaluation of the antioxidant potential of vanadium encapsulated guar gum nanoparticles.  

PubMed

The present study investigated the antioxidant potential of guar gum macroparticles (GGMs), vanadium oxide sulphate (VS) encapsulated guar gum macroparticles (GVMs), guar gum nanoparticles (GGNs), VS encapsulated guar gum nanoparticles (GVNs) and VS. GGNs and GVNs prepared by nanoprecipitation were characterized by SEM (scanning electron microscopy), TEM (transmission electron microscopy) and particle size analysis to confirm the nanostructure of the particles. Particle size analysis revealed that GVNs possess a size of 239 nm, about 148 nm larger than that of GGNs. TEM imaging and EDAX data also confirmed the formation of fine spherical nanoparticles with vanadium incorporation. In addition the larger size of GVNs also confirmed the vanadium incorporation. MTT assay showed that concentrations up to 100 nM of GVNs for 24 h exposure did not induce significant toxicity when VS was toxic (16%) at 100 nM. Various in vitro antioxidant assays (total reducing power, total antioxidant capacity, DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), hydroxyl radical and superoxide anion radical scavenging assays) revealed significantly high antioxidant potential of GVNs compared to GGNs, VS, GGMs and GVMs. The IC50 of GVNs was 23.21 ± 2.1 ?g mL(-1), 33.0 ± 2.93 ?g mL(-1), 21 ± 1.98 ?g mL(-1) and 22.79 ± 2.12 ?g mL(-1) for DPPH, ABTS, hydroxyl, superoxide anion scavenging activity assays respectively. The cell line based assay also proved that the GVN was more effective in reactive oxygen species (ROS) scavenging than VS against tertiary butyl hydrogen peroxide (TBHP) induced oxidative stress in H9c2 cell lines. The overall results indicated that vanadium in combination with nano guar gum exhibits significantly high antioxidant potential. PMID:24463743

Soumya, R S; Reshmi, R; Jomon, S; Antu, K A; Riya, M P; Raghu, K G

2014-03-01

322

Enzymatic depolymerization of gum tragacanth: bifidogenic potential of low molecular weight oligosaccharides.  

PubMed

Gum tragacanth derived from the plant "goat's horn" (Astragalus sp.) has a long history of use as a stabilizing, viscosity-enhancing agent in food emulsions. The gum contains pectinaceous arabinogalactans and fucose-substituted xylogalacturonans. In this work, gum tragacanth from Astragalus gossypinus was enzymatically depolymerized using Aspergillus niger pectinases (Pectinex BE Color). The enzymatically degraded products were divided into three molecular weight fractions via membrane separation: HAG1 < 2 kDa; 2 kDa < HAG2 < 10 kDa; HAG3 > 10 kDa. Compositional and linkage analyses showed that these three fractions also varied with respect to composition and structural elements: HAG1 and HAG2 were enriched in arabinose, galactose, and galacturonic acid, but low in fucose and xylose, whereas HAG3 was high in (terminal) xylose, fucose, and 1,4-bonded galacturonic acid, but low in arabinose and galactose content. The growth-stimulating potential of the three enzymatically produced gum tragacanth fractions was evaluated via growth assessment on seven different probiotic strains in single-culture fermentations on Bifidobacterium longum subsp. longum (two strains), B. longum subsp. infantis (three strains), Lactobacillus acidophilus , B. lactis, and on one pathogenic strain of Clostridium perfringens . The fractions HAG1 and HAG2 consistently promoted higher growth of the probiotic strains than HAG3, especially of the three B. longum subsp. infantis strains, and the growth promotion on HAG1 and HAG2 was better than that on galactan (control). HAG3 completely inhibited the growth of the C. perfringens strain. Tragacanth gum is thus a potential source of prebiotic carbohydrates that exert no viscosity effects and which may find use as natural functional food ingredients. PMID:23343141

Gavlighi, Hassan Ahmadi; Michalak, Malwina; Meyer, Anne S; Mikkelsen, J Dalgaard

2013-02-13

323

Hydrogen peroxide (H?O?) supply significantly improves xanthan gum production mediated by Xanthomonas campestris in vitro.  

PubMed

To improve xanthan gum productivity, a strategy of adding hydrogen peroxide (H?O?) was studied. The method could intensify oxygen supply through degradation of H?O? to oxygen (O?). In shake flask testing, the xanthan gum yield reached 2.8% (improved by 39.4%) when adding 12.5 mM H?O? after 24 h of fermentation. In fermentor testing, it was obvious that the oxygen conditions varied with the H?O? addition time. Eventually, gum yield of 4.2% (w/w) was achieved (increased by 27.3%). Compared with the method of intense mixing and increasing the air flow rate, adding H?O? to improve the dissolved oxygen concentration was more effective and much better. Moreover, addition of H?O? improved the quality of xanthan gum; the pyruvate content of xanthan was 4.4% (w/w), higher than that of the control (3.2%). PMID:22183692

Cheng, Rong; Lin, Lin; Zhang, Yongkui

2012-05-01

324

Influence of chemical extraction conditions on the physicochemical and functional properties of polysaccharide gum from durian (Durio zibethinus) seed.  

PubMed

Durian seed is an agricultural biomass waste of durian fruit. It can be a natural plant source of non-starch polysaccharide gum with potential functional properties. The main goal of the present study was to investigate the effect of chemical extraction variables (i.e., the decolouring time, soaking temperature and soaking time) on the physicochemical properties of durian seed gum. The physicochemical and functional properties of chemically-extracted durian seed gum were assessed by determining the particle size and distribution, solubility and the water- and oil-holding capacity (WHC and OHC). The present work revealed that the soaking time should be considered as the most critical extraction variable affecting the physicochemical properties of crude durian seed gum. PMID:22643356

Mirhosseini, Hamed; Amid, Bahareh Tabatabaee

2012-01-01

325

Collagen-poly(dialdehyde) guar gum based porous 3D scaffolds immobilized with growth factor for tissue engineering applications.  

PubMed

Here we report the preparation of collagen-poly(dialdehyde) guar gum based hybrid functionalized scaffolds covalently immobilized with platelet derived growth factor - BB for tissue engineering applications. Poly(dialdehyde) guar gum was synthesized from selective oxidation of guar gum using sodium periodate. The synthesized poly(dialdehyde) guar gum not only promotes crosslinking of collagen but also immobilizes the platelet derived growth factor through imine bonds. The covalent crosslinking formed in collagen improves thermal, swelling and biodegradation properties of the hybrid scaffolds. The prepared hybrid scaffolds show 3D interconnected honeycomb porous structure when viewed under a microscope. The release of immobilized platelet derived growth factor was seen up to 13th day of incubation thereby proving its sustained delivery. The developed hybrid scaffold leads to a quantum increase in NIH 3T3 fibroblast cell density and proliferation thereby demonstrating its potential for tissue engineering applications. PMID:25263907

Ragothaman, Murali; Palanisamy, Thanikaivelan; Kalirajan, Cheirmadurai

2014-12-19

326

STUDIES OF MIXING IN A CONCENTRIC TUBE AIRLIFT REACTOR CONTAINING XANTHAN GUM BY MEANS OF AN IMPROVED FLOW FOLLOWER  

Microsoft Academic Search

The influence of a pseudoplastic non-Newtonian fluid upon the hydrodynamic performance and mixing parameters of a concentric tube air-lift fermenter has been studied using a range of dilute xanthan gum solutions (0-0.5% weight by volume). Liquid circulation times vary in a complex pattern with increasing gum concentration. At low concentrations, circulation was more; rapid due to drag reduction whilst at

P. R. FIELDS; F. R. G. MITCHELL; N. K. H. SLATER

1984-01-01

327

Release properties of chemical and enzymatic crosslinked gelatin-gum Arabic microparticles containing a fluorescent probe plus vetiver essential oil  

Microsoft Academic Search

Oil-containing gelatin-gum Arabic microparticles were prepared by complex coacervation followed by crosslinking with glutaraldehyde or transglutaminase. A fluorescent mixture, khusimyl dansylate (KD) as the fluorescent compound mixed to the vetiver essential oil, was used as oil model. The effect of the type of crosslinking of the coacervated gelatin-gum Arabic membrane, the physical state of microparticles, wet or freeze-dried and the

Ana S. Prata; Maria H. A. Zanin; Maria I. Ré; Carlos R. F. Grosso

2008-01-01

328

Substitutes for tobacco smoking: a behavioral economic analysis of nicotine gum, denicotinized cigarettes, and nicotine-containing cigarettes  

Microsoft Academic Search

Both pharmacological and nonpharmacological stimuli may be responsible for the reinforcement and maintenance of tobacco smoking. The present study examined the self-administration of nicotine gum, denicotinized cigarettes, and nicotine-containing cigarettes utilizing a behavioral economic design in order to investigate the pharmacological and nonpharmacological aspects of cigarette smoking. Cigarette-deprived, dependent smokers worked for cigarette puffs and nicotine gum in daily operant

Matthew W Johnson; Warren K Bickel; Ari P Kirshenbaum

2004-01-01

329

Chemical composition and functional properties of gum exudates from the trunk of the almond tree (Prunus dulcis)  

Microsoft Academic Search

The physicochemical components and functional properties of the gum exudates from the trunk of the almond tree (Prunus dulcis) have been investigated, along with the emulsification and foaming properties. The gum exudates are composed on dry weight basis by 2.45% of proteins, 0.85% of fats and 92.36% of carbohydrates. The latter consist of arabinose, xylitol, galactose and uronic acid (46.8

N Mahfoudhi; M Chouaibi; F Donsì; G Ferrari; S Hamdi

2012-01-01

330

Effect of Salivary Flow Rate on Salivary Fluoride Clearance after Use of a Fluoride-Containing Chewing Gum  

Microsoft Academic Search

The fluoride concentration in whole saliva and the effect of variations in salivary flow rate were studied in 5 volunteers after use of a chewing gum (Fluomin®) containing 0.25 mg fluoride as sodium fluoride. Basal fluoride concentration during 2 consecutive days ranged between 0.3 and 1.1 ?mol\\/l. The salivary fluoride clearance was studied after chewing one piece of the gum.

A. Oliveby; J. Ekstrand; F. Lagerlöf

1987-01-01

331

The Effect of Chlorhexidine\\/Xylitol Chewing-Gum on Cariogenic Salivary Microf lora: A Clinical Trial in Elderly Patients  

Microsoft Academic Search

The effects of 14-day use of either a chlorhexidine\\/xylitol or a xylitol chewing-gum on salivary levels of mutans streptococci, lactobacilli, and yeasts were determined for 53 subjects (mean age 79.49 ± 7.7 years) participating in this randomised, double-blind, placebo-controlled trial. Salivary flow rates and enamel staining were measured and the attitudes of the subjects to gum chewing were evaluated by

D. Simons; E. A. M. Kidd; D. Beighton; B. Jones

1997-01-01

332

Effect of guar gum upon the partition coefficients of diacetyl, acetaldehyde, and ethanol in acidified milk products  

E-print Network

EFFECT OF GUAR GUM UPON THE PARTITION COEFFICIENTS OF DIACE~ ACETALDEHYDE& AND ETHANOL IN ACIDIFIED MILK PRODUCTS A Thesis by CHIH- YANG LO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE December 1992 Major Subject: Food Science and Technology EFFECT OF GUAR GUM UPON THE PARTITION COEFFICIENTS OF DIACETYL, ACETALDEHYDE, AND ETHANOL IN ACIDIFIED MILK PRODUCTS A Thesis by Chih- Yang Lo...

Lo, Chih-Yang

2012-06-07

333

The effects of chewing frequency and duration of gum chewing on salivary flow rate and sucrose concentration  

Microsoft Academic Search

On ten separate occasions, unstimulated saliva was collected from 12 adults and then eight samples of saliva over a 20-min period while chewing, in random order, 3 g of either Wrigley's Spearmint chewing-gum or gum-base at frequencies of 35, 50, 70, 90, or 130 chews\\/min. With both stimuli, flow rates peaked in the first minute of stimulation and then fell

C. Dong; A. D. Puckett; C. Dawes

1995-01-01

334

Pharmaceutical applications of various natural gums, mucilages and their modified forms.  

PubMed

A large number of plant based pharmaceutical excipients are available today. Gums and mucilages are the most commonly available plant ingredients with a wide range of applications in pharmaceutical and cosmetic industries. They are being used due to their abundance in nature, safety and economy. They have been extensively explored as pharmaceutical excipients. They are biocompatible, cheap and easily available. Natural materials have advantages over synthetic ones since they are chemically inert, nontoxic, less expensive, biodegradable and widely available. They can also be modified in different ways to obtain tailor-made materials for drug delivery systems and thus can compete with the available synthetic excipients. Recent trend toward the use of plant based and natural products demands the replacement of synthetic additives with natural ones. In this review, we describe the pharmaceutical applications of various natural gums, mucilages and their modified forms for the development of various drug delivery systems. PMID:23399207

Prajapati, Vipul D; Jani, Girish K; Moradiya, Naresh G; Randeria, Narayan P

2013-02-15

335

Functionalization of natural gum: an effective method to prepare iodine complex.  

PubMed

To overcome the drawbacks associated with iodine e.g. insolubility in water, etc., it has been complexed with polymers that have the ability to bind it. In this study, gum arabic (GA), a natural gum was functionalized to introduce new reactive groups that can easily interact with small molecules followed by iodination in ethanol solution to prepare an iodine complex. The samples were characterized by FTIR, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The synthesized iodine complex was found reddish-brown in colour and stable at room temperature. The interaction of free available iodine with functionalized GA was also studied and established by UV-vis spectrophotometer. The amount of iodine released in water was measured by iodometric titration method and its value compared with the available iodine complex, polyvinylpyrrolidone-iodine complex. The antimicrobial activity of iodine complex was tested against Escherichia coli (Gram negative bacteria) and found to be effective against it. PMID:23218326

Ahmad, Syed Ishraque; Mazumdar, Nasreen; Kumar, Sunil

2013-01-30

336

High yield production and purification of few layer graphene by gum arabic assisted physical sonication.  

PubMed

Exploiting the emulsification properties of low cost, environmentally safe Gum Arabic we demonstrate a high yield process to produce a few layer graphene with a low defect ratio, maintaining the pristine graphite structure. In addition, we demonstrate the need for and efficacy of an acid hydrolysis treatment to remove the polymer residues to produce 100% pure graphene. The scalable process gives yield of up to 5 wt% graphene based on 10 g starting graphite. The graphene product is compared with reduced graphene oxide produced through Hummer's method using UV-visible spectroscopy, SEM, TEM, and Raman spectroscopy. The two graphene materials show significant difference in these characterizations. Further, the film fabricated from this graphene exhibits 20 times higher electrical conductivity than that of the reduced graphene oxide. Sonication processing of graphite with environmentally approved biopolymers such as Gum Arabic opens up a scalable avenue for production of cheap graphene. PMID:23478744

Chabot, Victor; Kim, Brian; Sloper, Brent; Tzoganakis, Costas; Yu, Aiping

2013-01-01

337

Oral adverse reactions due to cinnamon-flavoured chewing gums consumption.  

PubMed

Cinnamon-flavoured products (toothpaste, chewing gum, food, candy and mouthwash) can cause oral adverse reactions; among these, the most common is contact stomatitis (cinnamon contact stomatitis, CCS). Signs and symptoms of contact allergic reactions affecting the oral mucosa can mimic other common oral disorders, making diagnosis difficult. As CCS may be more prevalent than believed and its clinical features can frequently determine misdiagnosis, we reviewed case reports and case series of oral adverse reactions due to cinnamon-containing chewing gums, emphasizing clinical aspects, diagnostic and management procedures. We also proposed an algorithm to perform a diagnosis of CCS as in the previous published literature the diagnostic approach was not based on a harmonized and shared evidence-based procedure. Moreover, as patients can refer to different specialists as dentists, dermatologists and allergists, a multidisciplinary approach is suggested. PMID:24004186

Calapai, G; Miroddi, M; Mannucci, C; Minciullo, Pl; Gangemi, S

2014-10-01

338

Preparation of microcapsules by complex coacervation of gum Arabic and chitosan.  

PubMed

Gum Arabic-chitosan microcapsules containing a commercially available blend of triglycerides (Miglyol 812 N) as core phase were synthesized by complex coacervation. This study was conducted to clarify the influence of different parameters on the encapsulation process, i.e. during the emulsion formation steps and during the shell formation, using conductometry, zeta potential, surface and interface tension measurement and Fourier-transform infrared spectroscopy. By carefully analyzing the influencing factors including phase volume ratio, stirring rate and time, pH, reaction time, biopolymer ratio and crosslinking effect, the optimum synthetic conditions were found out. For the emulsion step, the optimum phase volume ratio chosen was 0.10 and an emulsion time of 15 min at 11,000 rpm was selected. The results also indicated that the optimum formation of these complexes appears at a pH value of 3.6 and a weight ratio of chitosan to gum Arabic mixtures of 0.25. PMID:24274550

Butstraen, Chloé; Salaün, Fabien

2014-01-01

339

Facilitating Return of Bowel Function after Colorectal Surgery: Alvimopan and Gum Chewing  

PubMed Central

Postoperative ileus is common after colorectal surgery, and has a huge impact on hospital LOS. With the impeding cost crisis in the United States, safely reducing length of stay is essential. Chewing gum and pharmacological treatment with alvimopan are safe, simple tools to reduce postoperative ileus and its associated costs. Future research will determine if integrating these tools with laparoscopic procedures and enhanced recovery pathways is a best practice in colorectal surgery. PMID:24436673

Keller, Deborah; Stein, Sharon L.

2013-01-01

340

Removal of lead from aqueous solutions using Cassia grandis seed gum-graft-poly(methylmethacrylate)  

Microsoft Academic Search

Using persulfate\\/ascorbic acid redox system, a series of Cassia grandis seed gum-graft-poly(methylmethacrylate) samples were synthesized. The copolymer samples were evaluated for lead(II) removal from the aqueous solutions where the sorption capacities were found proportional to the grafting extent. The conditions for the sorption were optimized using copolymer sample of highest percent grafting. The sorption was found pH and concentration dependent,

Vandana Singh; Stuti Tiwari; Ajit Kumar Sharma; Rashmi Sanghi

2007-01-01

341

Gum odina: a novel matrix forming material for sustained drug delivery  

Microsoft Academic Search

The study concerns the evaluation of natural gum odina as novel sustained release matrix forming material in tablet formulation.\\u000a Matrix tablets were prepared by wet granulation technique. Diclofenac sodium was used as model drug. The tablet weight (250 mg)\\u000a and diameter (9 mm) was kept constant. The tablets were evaluated for physicochemical properties, drug content uniformity\\u000a and in vitro drug release kinetics.

Subas Chandra Dinda; Biswajit Mukherjee; Amalesh Samanta

342

Formulation Variables Influencing Drug Release from Layered Matrix System Comprising Chitosan and Xanthan Gum  

Microsoft Academic Search

The purpose of this study was to investigate the formulation variables influencing the drug release from the layered tablets\\u000a containing chitosan and xanthan gum as matrix component. Increasing the amount of lactose could diminish pH sensitive release\\u000a behavior of these matrix tablets. Effect of formulation variables on drug release from the prepared three-layered matrix tablets\\u000a was investigated. The amount of

Thawatchai Phaechamud; Garnpimol C. Ritthidej

2008-01-01

343

Studies on the steady shear flow behavior and functional properties of Lepidium perfoliatum seed gum  

Microsoft Academic Search

Flow properties of Lepidium perfoliatum gum, extracted from Qodume shahri seeds, as influences of concentrations (0.5%, 1%, 1.5% and 2%), temperatures (5, 25, 45, and 65°C), salts and pHs were investigated. Among the selected models, power law model well described the rheological behavior of the L. perfoliatum seed mucilage solutions with high determination coefficients, R2 and low root mean square

Arash Koocheki; Ali Reza Taherian; Aram Bostan

344

Release properties on gelatin-gum arabic microcapsules containing camphor oil with added polystyrene  

Microsoft Academic Search

In this study, gelatin blended with arabic gum microcapsules containing camphor oil with added polystyrene were fabricated by a compound coacervation method. The parameters of oil\\/wall volume ratio, emulsification stirring speed, concentration of cross-linking agent, treated time and oil release properties were investigated. In order to improve the constant release effect of camphor oil, oil-soluble polystyrene (PS) was used as

Chih-Pong Chang; Ting-Kai Leung; Shang-Ming Lin; Che-Chang Hsu

2006-01-01

345

Raphia hookeri gum as a potential eco-friendly inhibitor for mild steel in sulfuric acid  

Microsoft Academic Search

Exudate gum from Raphia hookeri (RH) was tested as corrosion inhibitor for mild steel in H2SO4 using weight loss and hydrogen evolution techniques at 30–60 °C. Results obtained revealed that RH act as corrosion inhibitor\\u000a for mild steel in sulfuric acid medium. The corrosion rates in all concentrations studied increased with rise in temperature.\\u000a The inhibition efficiency was observed to increase

S. A. Umoren; I. B. Obot; N. O. Obi-Egbedi

2009-01-01

346

Hydrolyzed guar gum decreases postprandial blood glucose and glucose absorption in the rat small intestine  

Microsoft Academic Search

We hypothesized that infusing partially hydrolyzed guar gum (PHGG) into the duodenum would reduce increases in postprandial plasma glucose by decreasing the rate of glucose diffusion from the small intestine luminal digesta of the rat. The postprandial plasma glucose and apparent glucose disappearance from the small intestine were measured after infusing artificial digesta containing 0 (control), 3.0, or 6.0 g\\/L

Toru Takahashi; Takeo Yokawa; Noriyuki Ishihara; Tsutomu Okubo; Djong-Chi Chu; Eri Nishigaki; Yuka Kawada; Masako Kato; Lekh Raj Juneja

2009-01-01

347

Hepatoprotective prenylaromadendrane-type diterpenes from the gum resin of Boswellia carterii.  

PubMed

Chemical examination of the exuded gum resin of Boswellia carterii resulted in the isolation of nine new prenylaromadendrane-type diterpenes, boscartols A-I (1-9). The structures of these compounds were established by extensive 1D and 2D NMR spectroscopic analyses, mass spectrometric data, and circular dichroism spectra. Compounds 1-3, 5, 6, 8, and 9 (10 ?M) showed moderate hepatoprotective activity against d-galactosamine-induced HL-7702 cell damage. PMID:24195447

Wang, Yan-gai; Ren, Jin; Wang, Ai-guo; Yang, Jian-bo; Ji, Teng-fei; Ma, Qin-Ge; Tian, Jin; Su, Ya-lun

2013-11-22

348

Structure of a heteroxylan of gum exudate of the palm Scheelea phalerata (uricuri)  

Microsoft Academic Search

The polysaccharide isolated from the gum exudate of palm Scheelea phalerata (SPN) was water-insoluble and composed of Fuc, Ara, Xyl, and uronic acid moieties in a 5:34:54:7 molar ratio: 12% of phenolics were also present. A soluble polysaccharide (SPNa) was obtained after alkaline treatment, which contained Fuc, Ara, Xyl and uronic acid in a 7:44:42:7 molar ratio, with only 2%

Fernanda F. Simas; Philip A. J. Gorin; Marco Guerrini; Annamaria Naggi; Guilherme L. Sassaki; Cirene L. Delgobo; Marcello Iacomini

2004-01-01

349

Remineralization of Artificial Caries-like Lesions in Human Enamel in situ by Chewing Sorbitol Gum  

Microsoft Academic Search

The objective of the study was to determine quantitatively the effect on the potential for in situ remineralization of artificial caries-like lesions in human enamel when sugar-free gum containing mainly sorbitol as sweetener was chewed after meals and snacks. Artificial white-spot lesions were created in extracted human premolars and divided into three parts. One part was used as reference and

S. A. Leach; G. T. R. Lee; W. M. Edgar

1989-01-01

350

Long-term Use of Nicotine Chewing Gum and Mercury Exposure from Dental Amalgam Fillings  

Microsoft Academic Search

In experimental studies, chewing gum has been shown to increase the release rate of mercury vapor from dental amalgam fillings. The aim of the present study was to investigate the influence of long-term frequent chewing on mercury levels in plasma and urine. Mercury levels in plasma (P-Hg) and urine (U-Hg), and urinary cotinine were examined in 18 subjects who regularly

G. Sällsten; J. Thorén; L. BarregÅrd; A. Schütz; G. Skarping

1996-01-01

351

Facilitating return of bowel function after colorectal surgery: alvimopan and gum chewing.  

PubMed

Postoperative ileus is common after colorectal surgery, and has a huge impact on hospital LOS. With the impeding cost crisis in the United States, safely reducing length of stay is essential. Chewing gum and pharmacological treatment with alvimopan are safe, simple tools to reduce postoperative ileus and its associated costs. Future research will determine if integrating these tools with laparoscopic procedures and enhanced recovery pathways is a best practice in colorectal surgery. PMID:24436673

Keller, Deborah; Stein, Sharon L

2013-09-01

352

Effect of nicotine chewing gum on smoking behaviour and as an aid to cigarette withdrawal  

Microsoft Academic Search

In a double-blind, placebo-controlled, crossover trial the effect of 2-mg nicotine chewing gum was studied in 43 smokers when they were smoking as inclined and when they were trying to stop smoking. Although 70% of the smokers stopped smoking during treatment, only 23% were still abstinent after one year. The effect of the nicotine, though significant, was small compared with

M A Russell; C Wilson; C Feyerabend; P V Cole

1976-01-01

353

The relative bioavailability of loratadine administered as a chewing gum formulation in healthy volunteers  

Microsoft Academic Search

Objective  The aim of this study was to investigate the pharmacokinetics of loratadine and its active metabolite desloratadine after single-dose administration of loratadine as a conventional tablet, orally disintegrating tablet (smelt tablet) and a chewing gum formulation with and without the collection of saliva.Methods  Twelve healthy male volunteers participated in a four-period cross-over trial evaluating the effect of dosage forms on the

Lene Noehr-Jensen; Per Damkier; Tanja Busk Bidstrup; Rasmus Steen Pedersen; Flemming Nielsen; Kim Brosen

2006-01-01

354

Acid Resistance of Enamel Subsurface Lesions Remineralized by a Sugar-Free Chewing Gum Containing Casein Phosphopeptide-Amorphous Calcium Phosphate  

Microsoft Academic Search

The aim of this clinical study was to investigate the acid resistance of enamel lesions remineralized in situ by a sugar-free chewing gum containing casein phosphopeptide-amorphous calcium phosphate nanocomplexes (CPP-ACP: Recaldent™). The study utilized a double-blind, randomized, crossover design with two treatments: (i) sugar-free gum containing 18.8 mg of CPP-ACP, and (ii) sugar-free gum not containing CPP-ACP as control. Subjects

Y. Iijima; F. Cai; P. Shen; G. Walker; C. Reynolds; E. C. Reynolds

2004-01-01

355

Use of natural gums and cellulose derivatives in production of sustained release metoprolol tablets.  

PubMed

Metoprolol tartrate sustained-release tablets (100 mg) were prepared using xanthan/guar gums and also hydroxypropyl methyl cellulose (HPMC) carboxymethyl-Cellulose (CMC) polymers by direct compression method. Physical characteristics of the tablets and water uptake in addition to their dissolution profiles were compared with standard (Lopressor SR) tablets. Dissolution test was performed in the phosphate buffer solution (pH 6.8) and the samples were analyzed spectrophotometerically in 275.7 nm. Dissolution studies showed that formulations containing 100 and 80% of HPMC, 100% of guar, and 20% of xanthan followed the Higuchi model, while those containing 60 and 40% HPMC and 100 and 80% xanthan followed a zero-order model. The tablets with 40% xanthen followed a Hixon-Crowell model. In cellulose derivatives the highest MDT and dissolution efficiency until 8 hr (DE8%) belonged to tablets with 40% HPMC, increasing the amount of CMC decreased the drug release rate, and formulations containing 60 and 40% of HPMC had the USP dissolution standards. While, in the gum formulations, the highest mean dissolution time and the lowest DE(8)% belonged to tablets with 100% xanthan, increasing the xanthan decreased the release rate of metoprolol, and formulations containing 80 and 100% xanthan had the USP dissolution standards. Results showed that natural gums are suitable for production of sustained-release tablets of metoprolol. PMID:16423799

Varshosaz, Jaleh; Tavakoli, Nasser; Eram, S Ali

2006-01-01

356

Synthesis of partially hydrolyzed graft copolymer (H-Ipomoea hederacea seed gum-g-polyacrylonitrile).  

PubMed

Polyacrylonitrile was grafted to Ipomoea hederacea (Ih) seed gum with 138.5% grafting yield and 43.55% grafting efficiency in a procedure that was performed under homogeneous microwave (MW) irradiation conditions for 70s in the absence of a radical initiator. Under similar conditions, a maximum grafting yield of 108% and 33.96% efficiency was achieved when the K2S2O8/ascorbic acid redox system was used as a radical initiator in a thermostatic water bath at 35 °C. The effects of reaction variables, such as monomer/Ih seed gum concentration, MW power, and exposure time on the graft copolymerization were studied. The partially hydrolyzed graft copolymer (H-Ih-g-PAN) formed a loose, porous surface and improved the water absorbency of Ih seed gum. The swelling behavior of H-Ih-g-PAN in various ionic salt (NaCl, MgCl2 and Na2SO4) solutions was also systematically investigated. The graft copolymer was further characterized using FTIR, TGA, XRD, and SEM. PMID:23618295

Yadav, Mithilesh; Singh, Somit Kumar; Rhee, Kyong Yop

2013-06-01

357

Bioadhesive Controlled Metronidazole Release Matrix Based on Chitosan and Xanthan Gum  

PubMed Central

Metronidazole, a common antibacterial drug, was incorporated into a hydrophilic polymer matrix composed of chitosan xanthan gum mixture. Hydrogel formation of this binary chitosan-xanthan gum combination was tested for its ability to control the release of metronidazole as a drug model. This preparation (MZ-CR) was characterized by in vitro, ex vivo bioadhesion and in vivo bioavailability study. For comparison purposes a commercial extended release formulation of metronidazole (CMZ) was used as a reference. The in vitro drug-release profiles of metronidazole preparation and CMZ were similar in 0.1 M HCl and phosphate buffer pH 6.8. Moreover, metronidazole preparation and CMZ showed a similar detachment force to sheep stomach mucosa, while the bioadhesion of the metronidazole preparation was higher three times than CMZ to sheep duodenum. The results of in vivo study indicated that the absorption of metronidazole from the preparation was faster than that of CMZ. Also, MZ-CR leads to higher metronidazole Cmax and AUC relative to that of the CMZ. This increase in bioavailability might be explained by the bioadhesion of the preparation at the upper part of the small intestine that could result in an increase in the overall intestinal transit time. As a conclusion, formulating chitosan-xanthan gum mixture as a hydrophilic polymer matrix resulted in a superior pharmacokinetic parameters translated by better rate and extent of absorption of metronidazole. PMID:20559494

Eftaiha, Ala’a F.; Qinna, Nidal; Rashid, Iyad S.; Al Remawi, Mayyas M.; Al Shami, Munther R.; Arafat, Tawfiq A.; Badwan, Adnan A.

2010-01-01

358

Diuretic activity of Boswellia serrata Roxb. oleo gum extract in albino rats.  

PubMed

The aim of the study was to evaluate the effect of crude aqueous extract of Boswellia serrata Roxb. oleo gum on urinary electrolytes, pH and diuretic activity in normal albino rats. Moreover, acute toxicity of the gum extract was assessed using mice. Albino rats were divided into five groups. Control group received normal saline (10 mg/kg), reference group received furosemide (10 mg/kg) and test groups were given different doses of crude extract (10, 30 and 50 mg/kg) by intra-peritoneal route, respectively. The Graph Pad Prism was used for the statistical analysis and p < 0.05 was considered statistically significant. Significant diuretic, kaliuretic and natriuretic effects were observed in the treated groups in a dose dependent manner. Diuretic index showed good diuretic activity of the crude extract. Lipschitz values indicated that the crude extract, at the dose of 50 mg/kg, showed 44 % diuretic activity compared to the reference drug. No lethal effects were observed among albino mice even at the higher dose of 3000 mg/kg. It is concluded that aqueous extract of Boswellia serrata oleo gum, at the dose of 50 mg/kg showed significant effects on urinary volume and concentration of urinary electrolytes with no signs of toxicity. PMID:25362605

Asif, Muhammad; Jabeen, Qaiser; Abdul-Majid, Amin Malik-Shah; Atif, Muhammad

2014-11-01

359

Formulation and In Vitro Evaluation of Ofloxacin Tablets using Natural Gums as Binders.  

PubMed

Natural gums are economical, easily available, and useful as tablet binders. In the present investigation, an attempt was made to formulate Ofloxacin tablets using three natural binders, namely Acacia arabica, Hibiscus esculentus, and xanthan gum. Such six batches of Ofloxacin tablets were prepared by using different types and amounts of the natural binders by the wet granulation method. The tablets were analyzed for their hardness, friability, and weight variation, and in vitro release was performed in a phosphate buffer at pH 6.8. The prepared tablets were also evaluated for their various release kinetics and similarity factors f2. The physical properties of the tablets containing the natural binders showed sufficient hardness, desirable disintegration time, and low friability. Their better percentage of drug release was observed as compared to the marketed formulation showing more than 85% drug release within 45 minutes. The in vitro release data was well-fitted into zero-order and the values of release exponent 'n' were between 0.303 and 0.514. The high similarity factor f2 of 64.50 was achieved with the best batch in comparison to the marketed tablets. The results obtained indicated that the gum Acacia arabica performed as well as gelatin compared to the other binders for the Ofloxacin tablet formulation. PMID:24959411

Mistry, Amisha K; Nagda, Chirag D; Nagda, Dhruti C; Dixit, Bharat C; Dixit, Ritu B

2014-06-01

360

Assessment of xanthan gum based sustained release matrix tablets containing highly water-soluble propranolol HCl.  

PubMed

The present study was carried out to develop oral sustained release tablets of propranolol HCl by different ratios of drug : matrix. Tablets were prepared by direct compression technique using xanthan gum and lactose. All the formulations (tablets) were evaluated for thickness, diameter, hardness, friability, weight variation, content of active ingredient, in vitro dissolution using USP dissolution apparatus-II and swelling index. In case of dissolution, an inverse relationship was noted between amount of xanthan gum and release rate of propranolol HCl and the drug release was gradually enhanced as the amount of the lactose increased. The direct release was observed between swelling index and xanthan gum concentration. Significant difference in different media was observed in release profile, indicating that propranolol HCI has better solubility in HCI buffer pH 1.2. Moreover, dissolution data at differing stirring speeds was also analyzed, indicating that the drug release profile was at 50 rpm comparative to 100 rpm. The kinetic treatment showed the best fitted different mathematical models (zero order, first order, Higuchi's, Hixson-Crowell and Korsmeyer Peppas model. Most of the formulations showed linearity in Higuchi's model. The drug release from these tablets was by Fickian diffusion and anomalous (non-Fickian) mechanisms. PMID:23614284

Ali, Atif; Iqbal, Muhammad; Akhtar, Naveed; Khan, Haji Muhamad Shoaib; Ullah, Aftab; Uddin, Minhaj; Khan, Muhammad Tahir

2013-01-01

361

[Chewing gum as an additional agent in maintaining oral hygiene versus smoking status--preliminary study].  

PubMed

Nowadays chewing gum is widely used in different age groups, so complying with proper duration and frequency of chewing is an important factor influencing the state of masticatory system. The study involved 112 dental students of the Medical University of Lublin. Everyday use of chewing gum declared 47,32% of cases. Chewing time up to 10 minutes was stated in 23,08% of respondents, 11-20 minutes in 40,38% of interviewees. Among the examined students 17,3% smoked cigarettes. In smokers group 83,33% of questioned chewed the gum every day, while among non-smokers - 43,37%. Chewing time shorter than 10 minutes declared 22,22% of smokers and 23,26% of non-smokers, while chewing time between 11-20 minutes - 27,78% i 44,35% of smokers and non-smokers respectively. Obtained results indicate the need of carrying out further studies aimed at the nicotine influence on saliva parameters with respect to development of diseases of hard tooth tissues. PMID:23421028

Nakonieczna-Rudnicka, Marta; Strycharz-Dudziak, Ma?gorzata; Bachanek, Teresa

2012-01-01

362

Effects of guar gum and cellulose on glucose absorption, hormonal release and hepatic metabolism in the pig  

NASA Technical Reports Server (NTRS)

Six Large White pigs (mean body-weight 59 (SE 1.7) kg) were surgically fitted with permanent catheters in the portal vein, the brachiocephalic artery and the right hepatic vein, as well as with electromagnetic flow probes around the portal vein and the hepatic artery, and allowed to recover. The non-anaesthetized animals were given a basal non-fibre diet (diet A) alone or together with 60 g guar gum/kg (diet B) or 150 g purified cellulose/kg (diet C) by substitution for mica. The diets were given for weekly periods and according to a replicated 3 x 3 Latin square design. On the last day of each such adaptation period, test meals of 800 g were given before blood sampling. Sampling was continued for 8 h. Guar gum strongly reduced glucose apparent absorption without changing the absorption and the hepatic uptake profiles. Production rates of insulin, gastric inhibitory polypeptide and insulin-like growth factor-1 (IGF-1) were lowest after guar gum ingestion. However, the reductions in peripheral blood insulin levels caused by guar gum were not associated with a change in hepatic insulin extraction. IGF-1 appeared to be strongly secreted by the gut, whereas the liver had a net uptake of the peptide. Ingestion of guar gum increased the hepatic extraction coefficient of gut-produced IGF-1. Guar gum ingestion appeared also to decrease glucagon secretion. Cellulose at the level consumed had very few effects on the variables considered. It is suggested that the modulation of intestinal mechanisms by guar gum was sufficient to mediate the metabolic effects described.

Nunes, C. S.; Malmlof, K.

1992-01-01

363

Effect of incorporation of pumpkin (Cucurbita moshchata) powder and guar gum on the rheological properties of wheat flour.  

PubMed

The present study was carried out to study the effect of incorporation of fibre rich pumpkin powder and guar gum on the farinographic characteristics of wheat flour. The flour and pumpkin powder were assessed for proximate composition, total dietary fibre, minerals and ?-carotene. Pumpkin powder contained appreciable amount of fibre, minerals and ?-carotene. The effects of incorporation of different levels of pumpkin powder and guar gum along with pumpkin powder on farinographic characteristics were studied. Dough development time, dough stability, time to break down and farinograph quality number increased whereas mixing tolerance index decreased with incorporation of pumpkin powder (> 5 %) and guar gum (1.0 and 1.5 %) along with pumpkin powder in the flour. Resistance to extension as well as extensibility of dough prepared increased significantly by adding pumpkin powder (5-15 %) whereas increase in resistance to extension only was noticed with inclusion of guar gum (0.5-1.5 %) to flour containing 5 % pumpkin powder. Results indicated that pumpkin can be processed to powder that can be utilized with guar gum for value addition. PMID:25328201

Kundu, Himani; Grewal, Raj Bala; Goyal, Ankit; Upadhyay, Neelam; Prakash, Saurabh

2014-10-01

364

Beneficial properties of selenium incorporated guar gum nanoparticles against ischemia/reperfusion in cardiomyoblasts (H9c2).  

PubMed

Nanotechnology for the treatment and diagnosis has been emerging recently as a potential area of research and development. In the present study, selenium incorporated guar gum nanoparticles have been prepared by nanoprecipitation and characterized by transmission electron microscopy and particle size analysis. The nanoparticles were screened for antioxidant potential (metal chelation, total reducing power and hydroxyl radical scavenging activity) and were evaluated against the cell line based cardiac ischemia/reperfusion model with special emphasis on oxidative stress and mitochondrial parameters. The cell based cardiac ischemia model was employed using H9c2 cell lines. Investigations revealed that there was a significant alteration (P ? 0.05) in the innate antioxidant status (glutathione?, glutathione peroxidase?, thioredoxin reductase?, superoxide dismutase?, catalase?, lipid peroxidation?, protein carbonyl?, xanthine oxidase? and caspase 3 activity?), mitochondrial functions (reactive oxygen species generation, membrane potential, and pore opening) and calcium homeostasis (calcium ATPase and intracellular calcium overload) during both ischemia and reperfusion. For comparative evaluation, selenium, guar gum and selenium incorporated guar gum nanoparticles were evaluated for their protective properties against ischemia/reperfusion. The study reveals that selenium incorporated guar gum nanoparticles were better at protecting the cells from ischemia/reperfusion compared to selenium and guar gum nanoparticles. The potent antioxidant capability shown by the sample in in vitro assays may be the biochemical basis of its better biological activity. Further, the nanodimensions of the particle may be the additional factor responsible for its better effect. PMID:25307064

Soumya, R S; Vineetha, V P; Salin Raj, P; Raghu, K G

2014-10-22

365

Reliability and validity of a quantitative color scale to evaluate masticatory performance using color-changeable chewing gum.  

PubMed

In the present study, we developed a novel color scale for visual assessment, conforming to theoretical color changes of a gum, to evaluate masticatoryperformance; moreover, we investigated the reliability and validity of this evaluation method using the color scale. Ten participants (aged 26.30 years) with natural dentition chewed the gum at several chewing strokes. Changes in color were measured using a colorimeter, and then, linearregression expressions that represented changes in gum color were derived. The color scale was developed using these regression expressions. Thirty-two chewed gums were evaluated using colorimeter and were assessed three times using the color scale by six dentists aged 25.27 (mean, 25.8) years, six preclinical dental students aged 21.23 (mean, 22.2) years, and six elderly individuals aged 68.84 (mean, 74.0) years. The intrarater and interrater reliability of evaluations was assessed using intraclass correlation coefficients. Validity of the method compared with a colorimeter was assessed using Spearman's rank correlation coefficient. All intraclass correlation coefficients were > 0.90, and Spearman's rank-correlation coefficients were > 0.95 in all groups. These results indicated that the evaluation method of the color-changeable chewing gum using the newly developed color scale is reliable and valid. PMID:24658959

Hama, Yohei; Kanazawa, Manabu; Minakuchi, Shunsuke; Uchida, Tatsuro; Sasaki, Yoshiyuki

2014-01-01

366

The effect of chewing gum on self-reported nicotine withdrawal: is it the flavor, the act of chewing, or both?  

PubMed

A healthy alternative that has been shown to lessen the severity of nicotine withdrawal symptoms during brief periods of nicotine abstinence (e.g., 3-4 h) is confectionary chewing gum (Cohen and colleagues, 1997, 1999, & 2001). The current study sought to build upon this line of research by examining the impact of chewing gum on nicotine withdrawal severity over an extended period of nicotine abstinence (e.g., 24 h) while also identifying the specific attributes of chewing gum that may be responsible for the reported decreases in withdrawal. Specifically, the acts of chewing, flavor, as well as the combination of the two, were independently examined. Twenty-four dependent cigarette smokers participated in three experimental conditions (e.g., a flavorless gum base, flavor strips, and flavored chewing gum) as well as a no product control across four weeks while abstaining from smoking for 24 h each week. Using repeated measures ANOVAs, a significant difference in withdrawal severity was reported by participants across conditions, F(3, 69)=2.89, p < .05. Follow-up analyses revealed that the flavored gum condition yielded significantly lower withdrawal scores than the flavorless gum base and no product control conditions. These findings indicate that chewing gum appears useful in lessening the severity of nicotine withdrawal symptoms over a 24-hour period of nicotine abstinence and that it is a combination of flavor and chewing that appears to lead to this effect. PMID:19914004

Cortez-Garland, Monica; Cohen, Lee M; Vanderveen, Joseph W; Cook, Katrina

2010-03-01

367

Adaptive genetic variation in water-use efficiency and gum yield in Acacia senegal provenances grown on clay soil in the Blue Nile region, Sudan  

Microsoft Academic Search

The genetic variation in shoot growth, water-use efficiency (as assessed by ?13C) and gum production was compared among eight Acacia senegal provenances originating from contrasting conditions of the gum arabic belt in central Sudan. The experimental site was in the clay plain region. Carbon isotope ratios were obtained from leaves and branch wood samples of the dissimilar A. senegal provenances.

El Amin Y. Raddad; Olavi Luukkanen

2006-01-01

368

DAIRY FOODS TECHNICAL NOTES Changes in Electrical Energy Requirements to Operate an Ice Cream Freezer as a Function of Sweeteners and Gums  

Microsoft Academic Search

Changes in electrical energy required to operate a continuous freezer were monitored for various ice cream for- mulae. Ice cream formulae consisted of nine different combinations of sucrose, 36 DE corn syrup, and 42 high fructose corn syrup as well as two ratios of guar gum to locust bean gum. Within the same sweetening system, a mix high in locust

D. E. SMITH; A. S. BAKSHI; S. A. GAY

369

Serum Concentrations and Accumulation of Silver in Skin During Three Months Treatment with an Anti-smoking Chewing Gum containing Silver Acetate  

Microsoft Academic Search

Silver acetate chewing gum was used for 12 weeks as a smoking deterrent in 21 adults. The effect of silver on serum concentrations, its accumulation in the skin and the risk of developing clinically evident argyria were investigated. Serum concentrations of silver clearly rose after chewing gum use had started, and concentrations quickly returned to normal after use had ceased.

E. J. Jensen; J. Rungby; J. C. Hansen; E. Schmidt; B. Pedersen; R. Dahl

1988-01-01

370

Effects of a chewing gum containing phosphoryl oligosaccharides of calcium (POs-Ca) and fluoride on remineralization and crystallization of enamel subsurface lesions in situ  

Microsoft Academic Search

ObjectivesManufacturers are adding fluoride (F) to calcium-containing chewing gums to further promote enamel remineralization. The aim of this study was to assess the effect of a chewing gum containing phosphoryl oligosaccharides of calcium (POs-Ca) and fluoride on remineralization of enamel subsurface lesions, in a double-blind, randomized controlled in situ trial.

Yuichi Kitasako; Miyuki Tanaka; Alireza Sadr; Hidenori Hamba; Masaomi Ikeda; Junji Tagami

2011-01-01

371

Sonication-based improvement of the physicochemical properties of Guar Gum as a potential substrate for modified drug delivery systems.  

PubMed

Guar Gum is a natural polysaccharide that, due to its physicochemical properties, is extensively investigated for biomedical applications as a matrix for modified drug delivery, but it is also used in the food industry as well as in cosmetics. A commercial sample of Guar Gum was sonicated for different periods of time, and the reduction in the average molecular weight was monitored by means of viscometric measurements. At the same time, the rheological behaviour was also followed, in terms of viscoelasticity range, flow curves, and mechanical spectra. Sonicated samples were used for the preparation of gels in the presence of borate ions. The effect of borax on the new samples was investigated by recording mechanical spectra, flow curves, and visible absorption spectra of complexes with Congo Red. The anisotropic elongation, observed in previous studies with tablets of Guar Gum and borax, was remarkably reduced when the sonicated samples were used for the preparation of the gels. PMID:23984426

Ansari, Siddique Akber; Matricardi, Pietro; Cencetti, Claudia; Di Meo, Chiara; Carafa, Maria; Mazzuca, Claudia; Palleschi, Antonio; Capitani, Donatella; Alhaique, Franco; Coviello, Tommasina

2013-01-01

372

Sonication-Based Improvement of the Physicochemical Properties of Guar Gum as a Potential Substrate for Modified Drug Delivery Systems  

PubMed Central

Guar Gum is a natural polysaccharide that, due to its physicochemical properties, is extensively investigated for biomedical applications as a matrix for modified drug delivery, but it is also used in the food industry as well as in cosmetics. A commercial sample of Guar Gum was sonicated for different periods of time, and the reduction in the average molecular weight was monitored by means of viscometric measurements. At the same time, the rheological behaviour was also followed, in terms of viscoelasticity range, flow curves, and mechanical spectra. Sonicated samples were used for the preparation of gels in the presence of borate ions. The effect of borax on the new samples was investigated by recording mechanical spectra, flow curves, and visible absorption spectra of complexes with Congo Red. The anisotropic elongation, observed in previous studies with tablets of Guar Gum and borax, was remarkably reduced when the sonicated samples were used for the preparation of the gels. PMID:23984426

Ansari, Siddique Akber; Cencetti, Claudia; Carafa, Maria; Mazzuca, Claudia; Capitani, Donatella; Coviello, Tommasina

2013-01-01

373

Effect of Encapsulating Nitrate in Sesame Gum on In vitro Rumen Fermentation Parameters.  

PubMed

Encapsulation is a method used to protect material from certain undesirable environments, for controlled release at a more favorable time and place. Animal productivity would be enhanced if feed additives are delivered to be utilized at their site of action, bypassing the rumen where they are likely to be degraded by microbial action. A novel method of encapsulation with sesame gum was used to coat nitrate, a known enteric methane mitigating agent, and tested for the effect on methane reduction and other in vitro fermentation parameters using rumen fluid from cannulated Hanwoo steers. Orchard grass was used as basal diet for fermentation. The treatments were matrix (1.1 g sesame gum+0.4 g sesame oil cake) only, encapsulated nitrate (matrix+nitrate [21 mM]), free nitrate (21 mM), and a control that contained no additive. Analyses of fermentation parameters were done at 0, 3, 6, 9, 12, 24, and 48 h time periods. In comparison to control, both free and encapsulated nitrate produced significantly reduced (p<0.01) methane (76% less) and also the total volatile fatty acids were reduced. A significantly higher (p<0.01) concentration of ammonia nitrogen was obtained with the encapsulated nitrate treatment (44%) compared to the free form (28%) and matrix only (20%) (p = 0.014). This might suggest slow release of encapsulated nitrate so that it is fully reduced to ammonia. Thus, this pioneering study found a significant reduction in methane production following the use of sesame gum encapsulated nitrate that shows the potential of a controlled release system in enhancing sustainability of ruminant production while reducing/eliminating the risk of nitrite toxicity. PMID:25358317

Mamvura, Chiedza Isabel; Cho, Sangbuem; Mbiriri, David Tinotenda; Lee, Hong-Gu; Choi, Nag-Jin

2014-11-01

374

Variations in tongue-palate swallowing pressures when swallowing xanthan gum-thickened liquids.  

PubMed

Thickened liquids are frequently recommended to reduce the risk of aspiration in patients with oropharyngeal dysphagia. Although it has previously been reported that tongue-palate pressures increase when swallowing spoon-thick and semi-solid consistencies compared to thin liquids, relatively little is known about how swallowing behaviors differ when swallowing liquids of nectar- or honey-thick consistency. Furthermore, previous studies have primarily used starch-based thickeners, and little is known about swallowing behaviors with xanthan gum-thickened liquids, which have recently been introduced for dysphagia management. In this study, we measured variations in tongue-palate pressures during the swallowing of liquids thickened to apparent viscosities of 190, 250, and 380 mPa s at 50/s using increasing concentrations of xanthan gum (0.5, 0.63 and 0.87 w/w%). The viscosity differences between these nectar- and honey-thick stimuli were confirmed to exceed sensory perceptual discrimination thresholds. Data were collected from 78 healthy adults in two sex-balanced age-groups (young; mature) and compared to reference values obtained during water swallowing. The results confirm that increased amplitudes of tongue-palate pressure were used when swallowing the thickened liquid stimuli, compared to swallows of water, and for the honey-thick liquid compared to the two nectar-thick liquids. Age-related reductions were seen in tongue strength but not in swallowing pressures, which fell below 40 % of maximum isometric pressure values. Thus, the use of xanthan gum-thickened liquids is unlikely to tax the swallowing system in terms of tongue pressure generation requirements, even in seniors with reduced maximum isometric tongue pressure measures. PMID:25087111

Steele, Catriona M; Molfenter, Sonja M; Péladeau-Pigeon, Melanie; Polacco, Rebecca C; Yee, Clemence

2014-12-01

375

Effect of Encapsulating Nitrate in Sesame Gum on In vitro Rumen Fermentation Parameters  

PubMed Central

Encapsulation is a method used to protect material from certain undesirable environments, for controlled release at a more favorable time and place. Animal productivity would be enhanced if feed additives are delivered to be utilized at their site of action, bypassing the rumen where they are likely to be degraded by microbial action. A novel method of encapsulation with sesame gum was used to coat nitrate, a known enteric methane mitigating agent, and tested for the effect on methane reduction and other in vitro fermentation parameters using rumen fluid from cannulated Hanwoo steers. Orchard grass was used as basal diet for fermentation. The treatments were matrix (1.1 g sesame gum+0.4 g sesame oil cake) only, encapsulated nitrate (matrix+nitrate [21 mM]), free nitrate (21 mM), and a control that contained no additive. Analyses of fermentation parameters were done at 0, 3, 6, 9, 12, 24, and 48 h time periods. In comparison to control, both free and encapsulated nitrate produced significantly reduced (p<0.01) methane (76% less) and also the total volatile fatty acids were reduced. A significantly higher (p<0.01) concentration of ammonia nitrogen was obtained with the encapsulated nitrate treatment (44%) compared to the free form (28%) and matrix only (20%) (p = 0.014). This might suggest slow release of encapsulated nitrate so that it is fully reduced to ammonia. Thus, this pioneering study found a significant reduction in methane production following the use of sesame gum encapsulated nitrate that shows the potential of a controlled release system in enhancing sustainability of ruminant production while reducing/eliminating the risk of nitrite toxicity. PMID:25358317

Mamvura, Chiedza Isabel; Cho, Sangbuem; Mbiriri, David Tinotenda; Lee, Hong-gu; Choi, Nag-Jin

2014-01-01

376

What can we learn from the saga of chitosan gums in hyperphosphatemia therapy?  

PubMed

Control of high serum phosphorus, a marker of poor outcome, is still a poorly achieved goal in dialysis therapy. Therefore, the 2009 study (Savica et al., J Am Soc Nephrol 20: 639-644, 2009) showing a significant drop of serum phosphate (2.35 mg/dl) after only 2 weeks of chewing a chitosan-containing gum two times per day was received with great hopes by the renal community. Chitosan is a polymer of glucosamine, similar to sevelamer, which allegedly would bind phosphate present in high concentrations in the saliva of renal patients. Recent randomized studies, however, have been unable to duplicate these results. A systematic and detailed quantitative analysis of the available data was performed. It concluded that the amount of chitosan contained in the chewing gum (20 mg) is too little to account for the originally observed reduction in serum phosphate and be of any use as a phosphate binding agent in the management of hyperphosphatemia. It was postulated that the original marked drop in serum phosphate may have been caused by the Hawthorne effect, which is frequently observed in nonrandomized clinical trials. Two important lessons derived from this analysis are emphasized. The first lesson is the demonstration of the importance of randomized, placebo-controlled studies in clinical research. If randomization had been performed in the original study, the Hawthorne effect would have been detected. The second lesson is showing the importance of quantitative analysis, which in this case, would have avoided the time and effort expended in several randomized clinical trials that eventually concluded the ineffectiveness of the chitosan-containing chewing gums as a phosphate binder. PMID:24408115

Oh, Man S; Uribarri, Jaime

2014-05-01

377

Dissolution Improvement of Atorvastatin Calcium using Modified Locust Bean Gum by the Solid Dispersion Technique  

PubMed Central

The present research was aimed at the enhancement of the dissolution rate of atorvastatin calcium by the solid dispersion technique using modified locust bean gum. Solid dispersions (SD) using modified locust bean gum were prepared by the modified solvent evaporation method. Other mixtures were also prepared by physical mixing, co-grinding, and the kneading method. The locust bean gum was subjected to heat for modification. The prepared solid dispersions and other mixtures were evaluated for equilibrium solubility studies, content uniformity, FTIR, DSC, XRD, in vitro drug release, and in vivo pharmacodynamic studies. The equilibrium solubility was enhanced in the solid dispersions (in a drug:polymer ratio of 1:6) and other mixtures such as the co-grinding mixture (CGM) and kneading mixture (KM). Maximum dissolution rate was observed in the solid dispersion batch SD3 (i.e. 50% within 15 min) with maximum drug release after 2 h (80%) out of all solid dispersions. The co-grinding mixture also exhibited a significant enhancement in the dissolution rate among the other mixtures. FTIR studies revealed the absence of drug-polymer interaction in the solid dispersions. Minor shifts in the endothermic peaks of the DSC thermograms of SD3 and CGM indicated slight changes in drug crystallinity. XRD studies further confirmed the results of DSC and FTIR. Topological changes were observed in SEM images of SD3 and CGM. In vivo pharmacodynamic studies indicated an improved efficacy of the optimized batch SD3 as compared to the pure drug at a dose of 3 mg/kg/day. Modified locust bean gum can be a promising carrier for solubility enhancement of poorly water-soluble drugs. The lower viscosity and wetting ability of MLBG, reduction in particle size, and decreased crystallinity of the drug are responsible for the dissolution enhancement of atorvastatin. The co-grinding mixture can be a good alternative to solid dispersions prepared by modified solvent evaporation due to its ease of preparation and significant improvement in dissolution characteristics. PMID:24634850

Panghal, Dharmila; Nagpal, Manju; Thakur, Gurjeet Singh; Arora, Sandeep

2014-01-01

378

Dissolution Improvement of Atorvastatin Calcium using Modified Locust Bean Gum by the Solid Dispersion Technique.  

PubMed

The present research was aimed at the enhancement of the dissolution rate of atorvastatin calcium by the solid dispersion technique using modified locust bean gum. Solid dispersions (SD) using modified locust bean gum were prepared by the modified solvent evaporation method. Other mixtures were also prepared by physical mixing, co-grinding, and the kneading method. The locust bean gum was subjected to heat for modification. The prepared solid dispersions and other mixtures were evaluated for equilibrium solubility studies, content uniformity, FTIR, DSC, XRD, in vitro drug release, and in vivo pharmacodynamic studies. The equilibrium solubility was enhanced in the solid dispersions (in a drug:polymer ratio of 1:6) and other mixtures such as the co-grinding mixture (CGM) and kneading mixture (KM). Maximum dissolution rate was observed in the solid dispersion batch SD3 (i.e. 50% within 15 min) with maximum drug release after 2 h (80%) out of all solid dispersions. The co-grinding mixture also exhibited a significant enhancement in the dissolution rate among the other mixtures. FTIR studies revealed the absence of drug-polymer interaction in the solid dispersions. Minor shifts in the endothermic peaks of the DSC thermograms of SD3 and CGM indicated slight changes in drug crystallinity. XRD studies further confirmed the results of DSC and FTIR. Topological changes were observed in SEM images of SD3 and CGM. In vivo pharmacodynamic studies indicated an improved efficacy of the optimized batch SD3 as compared to the pure drug at a dose of 3 mg/kg/day. Modified locust bean gum can be a promising carrier for solubility enhancement of poorly water-soluble drugs. The lower viscosity and wetting ability of MLBG, reduction in particle size, and decreased crystallinity of the drug are responsible for the dissolution enhancement of atorvastatin. The co-grinding mixture can be a good alternative to solid dispersions prepared by modified solvent evaporation due to its ease of preparation and significant improvement in dissolution characteristics. PMID:24634850

Panghal, Dharmila; Nagpal, Manju; Thakur, Gurjeet Singh; Arora, Sandeep

2014-03-01

379

Efficacy of acute administration of nicotine gum in relief of cue-provoked cigarette craving  

Microsoft Academic Search

  \\u000a \\u000a Rationale. Acute cravings, often provoked by exposure to smoking cues, appear to be important triggers for smoking relapse. Relief\\u000a of acute craving may therefore be an important step in preventing relapse.\\u000a \\u000a \\u000a \\u000a \\u000a Objectives. This study was undertaken to assess the effectiveness of nicotine gum in relieving acute craving.\\u000a \\u000a \\u000a \\u000a \\u000a Methods. A multi-center, randomized, placebo-controlled study was conducted with smokers (n=296) who

Saul Shiffman; William G. Shadel; Raymond Niaura; Moise A. Khayrallah; Douglas E. Jorenby; Charles F. Ryan; Clifford L. Ferguson

2003-01-01

380

Comparison between classical GUM and Bayesian uncertainty estimation approaches in SPRT calibrations  

NASA Astrophysics Data System (ADS)

In this paper a comparison between the results of an uncertainties assessment, using different approaches, of the calibration of Standard Platinum Resistance Thermometers (SPRT) in fixed points are examined. Three different approaches are selected: classical GUM, propagation of probability distribution functions using Monte Carlo method, and the Bayesian approach. They are applied to the mathematical model proposed in the document "Uncertainties in the Realisation of the SPRT subranges of the ITS-90", prepared by the Working Group 3 of the Consultative Committee for Thermometry, and their results are discussed.

del Campo, D.; García, C.; Ruiz, S.

2013-09-01

381

Green synthesis, characterization and catalytic activity of palladium nanoparticles by xanthan gum  

NASA Astrophysics Data System (ADS)

Here, we report the synthesis, characterization and catalytic evaluation of palladium nanoparticles (PdNPs) using xanthan gum, acting as both reducing and stabilizing agent without using any synthetic reagent. The uniqueness of our method lies in its fast synthesis rates using hydrothermal method in autoclave at a pressure of 15 psi and at 120 °C temperature by 10 min time. The formation and size of the PdNPs were characterized by UV-visible spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and transmission electron microscopy. The catalytic activity of PdNPs was evaluated on the reduction of 4-nitrophenol to 4-aminophenol by sodium borohydride using spectrophotometry.

Santoshi kumari, Amrutham; Venkatesham, Maragoni; Ayodhya, Dasari; Veerabhadram, Guttena

2014-05-01

382

Molecular gas in cometary globules: CG4 and CG 6 in the GUM Nebula  

Microsoft Academic Search

With the SEST telescope, we observed ^12^CO(10,->^13^)CO(10,->and) C^18^O(10)->emission from the cometary globules CG4 and CG6 in the Gum Nebula and also CS(21->and) HCO^+^(10->in) CG4. There are =~50Msun_ and =~5.5Msun_ of molecular hydrogen, respectively, in CG4 and CG6. The gas kinetic temperature is =~16K in both globules. The gas kinematics indicate the globules are strongly affected by ionization fronts on their

E. Gonzalez-Alfonso; J. Cernicharo; S. J. E. Radford

1995-01-01

383

Dislocation mobility in gum metal ?-titanium alloy studied via insitu transmission electron microscopy  

NASA Astrophysics Data System (ADS)

In situ tensile tests in a transmission electron microscope were carried out on a “Gum Metal” ?-titanium alloy. Conventional dislocation slip was observed to be the only mechanism occurring during the plastic deformation. The low mobility of screw dislocations was shown to be due to their core structure configuration. Nanometer-sized obstacles were also present but have a weaker effect on the dislocation mobility. The density of these obstacles and the variation in energy due to the core structure of screw dislocations were measured and compared to theoretical data in the literature.

Castany, Philippe; Besse, Magali; Gloriant, Thierry

2011-07-01

384

Structure of arabinogalactan-protein from Acacia gum: from porous ellipsoids to supramolecular architectures.  

PubMed

The structure of the arabinogalactan-protein (AGP) fraction of the gum exudate of Acacia senegal (gum Arabic) isolated from hydrophobic interaction chromatography was investigated using HPSEC-MALLS, small angle neutron scattering and TEM observations. Literature reported that the AGP structure of gum Arabic adopts a very compact conformation in solution due to the attachment of short arabinoside side chains and much larger blocks of carbohydrate to the polypeptidic backbone. The present study revealed that AGP in solution had a weight average molecular weight Mw of 1.86×10(6) g mol(-1) and a radius of gyration Rg of 30 nm. In addition, two exponent values were identified in the Rg, [?], Rh and ? vs. Mw relationships highlighting two types of conformations depending on the molecular weight range considered: a low molar mass population with long-chain branching and a compact conformation and a high molar mass population with short-chain branching and an elongated conformation. AGP would behave in solution as a branched or hyper-branched polymer with conformations ranging from globular to elongated shape depending on the size of the carbohydrate branches. Small angle scattering form factor revealed an elongated average conformation corresponding to a triaxial ellipsoid while inverse Fourier transform of the scattering form factor gave a maximum dimension for AGP of 64 nm. Transmission electron microscopy highlighted the existence of two types of flat objects with thicknesses below 3-5 nm, single particles with a more or less anisotropic spheroidal shape and aggregated structures with a more elongated shape. A remarkable feature of all particle morphologies was the presence of an outer structure combined to an inner more or less porous network of interspersed chains or interacting structural blocks, as previously found for the arabinogalactan (AG) main molecular fraction of Acacia gum. However, clear differences were observed in the density and morphology of the inner porous network, probably highlighting differences in the degree of branching. The existence of assembled AG as part of the AGP family was confirmed using TEM micrographs at high resolution. Fused AGP dimers, trimers, tetramers and multimers were also identified. These molecular assemblies questioned about the nature of interactions involved. PMID:24751048

Renard, D; Garnier, C; Lapp, A; Schmitt, C; Sanchez, C

2012-09-01

385

Gum heteropolysaccharide and free reducing mono- and oligosaccharides of Anadenanthera colubrina  

Microsoft Academic Search

The gum from Anadenanthera colubrina consists mainly of a complex high-arabinose heteropolysaccharide with a (1 ? 3)-linked ?-d-Galp main-chain and many different side-chains. These contain ?-d-Galp-[(1 ? 6)-?-d-Galp]m-(1 ? 6)-, substituted in turn at O-3 by ?-l-Araƒ-[(1 ? 3)-?-l-Araƒ-]0?2. Also present are (1) main-chain units substituted at O-4 and O-6 by ?-l-Araƒ units, (2) side-chains of Rhap-(1 ? 4)-?-d-GlcpA-(1 ?

Cirene L. Delgobo; Philip A. J. Gorin; Christopher Jones; Marcello Iacomini

1998-01-01

386

Structure of a glycoglucuronomannan from the gum exudate of Vochysia tucanorum (family Vochysiaceae)  

Microsoft Academic Search

The polysaccharide (VTP) from the gum exudate of Vochysia tucanorum gave aqueous solutions of low viscosity. VTP contained two components, which on freeze–thawing, gave rise to soluble (S-VTP) and precipitated (P-VTP) fractions, with Mw 350,000 and 520,000g\\/mol, and dn\\/dc 0.134 and 0.139, respectively. Acid hydrolysis of S-VTP provided Ara, Xyl, Man, Gal, Glc in a 43:1:5:18:2 molar ratio (GC–MS) with

Ricardo Wagner; Fernanda F. Simas; Graciele C. Z. Pereira; Aline Angeli; José O. Brito; Sandra M. Woranovicz-Barreira; Cirene L. Delgobo; Guilherme L. Sassaki; Marcello Iacomini; Philip A. J. Gorin

2007-01-01

387

Oral ulceration due to chronic use of Nicorette gum: case report.  

PubMed

Oral ulceration is a common presentation in a dental clinic. These ulcers may be acute or chronic, based on the duration of symptoms. The etiology of oral ulceration can range from trauma to squamous cell carcinoma. It is the responsibility of the dentist to differentiate the various etiologies of oral ulceration for proper management. This case report is presented to remind dentists that the long-term use of Nicorette gum should be considered in the differential diagnosis of chronic oral ulcers. PMID:20591780

Narayana, Nagamani; Meinberg, Trudy

2010-01-01

388

Multi-temporal and Change Analysis of Land Use Land Cover in the Gum Arabic Belt in Kordofan, Sudan  

NASA Astrophysics Data System (ADS)

The gum arabic belt in Sudan plays a significant role in environmental, social and economical aspects. The belt has suffered from deforestation and degradation due to natural hazards and human activities. The research was conducted in North Kordofan State, which is affected by modifications in conditions and composition of vegetation cover trends in the gum arabic belt as in the rest of the Sahelian Sudan zone. The research investigated the possibility of identification, monitoring and mapping of the land use land cover changes and dynamics in the gum arabic belt during the last 35 years. Also a newly approach of object-based classification was applied for image classification. The study used imageries from different satellites (Landsat and ASTER) and multi-temporal dates (MSS 1972, TM 1985, ETM+ 1999 and ASTER 2007) acquired in dry season (November). The imageries were geo-referenced and radiometrically corrected by using ENVI-FLAASH software. Application of multi-temporal remote sensing data in gum arabic belt demonstrated successfully the identification and mapping of land use land cover into five main classes. Forest dominated by Acacia senegal class was separated covering an area of 21% and 24% in the year 2007 for areas A and B, respectively. The land use land cover structure in the gum arabic belt has obvious changes and reciprocal conversions between the classes indicating the trends and conditions caused by the human interventions as well as ecological impacts on Acacia senegal trees. The study revealed a drastic loss of Acacia senegal cover by 25% during the period of 1972 to 2007. The study come out with some valuable recommendations and comments which could contribute positively in using remotely sensed imagery and GIS techniques to explore management tools of Acacia senegal stands in gum Arabic belt.

Adam, Hassan Elnour; Csaplovics, Elmar

2012-07-01

389

Shear rheology and filament stretching behaviour of xanthan gum and carboxymethyl cellulose solution in presence of saliva  

PubMed Central

The objective of the work reported in this paper is to determine if saliva addition has an effect on the rheology of xanthan gum solutions. The reasons for the interest was that it has been previously reported that flavour release from high viscosity xanthan thickened foods is not reduced in the same way as foods thickened by other hydrocolloids at comparable viscosities. It was previously postulated that this could be due to an interaction between saliva and xanthan that could change the microstructure and rheology of xanthan solutions. In this work the effect of saliva on the rheology of CMC and xanthan solutions was compared. Solutions of molecularly dissolved xanthan gum and CMC mixed with water or human whole saliva at a ratio of 5:1 showed little impact of the presence of saliva on steady shear or dynamic viscosity for the two hydrocolloids. In filament thinning experiments saliva addition significantly increased filament break-up time for xanthan gum while it had little effect on the break-up time of the CMC filament. Also, filament thinning appeared a lot less even and was not as reproducible in the case of xanthan gum. Addition of CMC and hydroxypropyl methylcellulose (HPMC) to xanthan gum solutions showed a similar increase in break-up time to saliva, but to see this effect the viscosity of the added CMC or HPMC solution had to be very much higher than the viscosity of saliva. The results are discussed in the context of the structure of xanthan gum and the reported extensional rheology of saliva.

Choi, Hyejung; Mitchell, John R.; Gaddipati, Sanyasi R.; Hill, Sandra E.; Wolf, Bettina

2014-01-01

390

Anti-inflammatory activity of Chios mastic gum is associated with inhibition of TNF-alpha induced oxidative stress  

Microsoft Academic Search

Background  Gum of Chios mastic (Pistacia lentiscus var. chia) is a natural antimicrobial agent that has found extensive use in pharmaceutical products and as a nutritional supplement.\\u000a The molecular mechanisms of its anti-inflammatory activity, however, are not clear. In this work, the potential role of antioxidant\\u000a activity of Chios mastic gum has been evaluated.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Scavenging of superoxide radical was investigated by

Angelike Triantafyllou; Alfiya Bikineyeva; Anna Dikalova; Rafal Nazarewicz; Stamatios Lerakis; Sergey Dikalov

2011-01-01

391

Randomized controlled trial to evaluate tooth stain reduction with nicotine replacement gum during a smoking cessation program  

PubMed Central

Background In addition to its general and periodontal health effects smoking causes tooth staining. Smoking cessation support interventions with an added stain removal or tooth whitening effect may increase motivation to quit smoking. Oral health professionals are well placed to provide smoking cessation advice and support to patients. The objective of the present study was to evaluate the effect of Nicorette® Freshmint Gum used in a smoking cessation programme administered in a dental setting, on extrinsic stain and tooth shade among smokers. Methods An evaluator-blinded, randomized, 12-week parallel-group controlled trial was conducted among 200 daily smokers motivated to quit smoking. Participants were randomised to use either the Nicorette® Freshmint Gum or Nicorette® Microtab (tablet). Tooth staining and shade were rated using the modified Lobene Stain Index and the Vita® Shade Guide at baseline, weeks 2, 6 and 12. To maintain consistency with other whitening studies, the primary end-point was the mean change in stain index between baseline and week 6. Secondary variables included changes in stain measurements and tooth shade at the other time points the number of gums or tablets used per day and throughout the trial period; and the number of cigarettes smoked per day. Treatments were compared using analysis of covariance (ANCOVA), using treatment and nicotine dependence as factors and the corresponding baseline measurement as a covariate. Each comparison (modified intention-to-treat) was tested at the 0.05 level, two-sided. Within-treatment changes from baseline were compared using a paired t-test. Results At week 6, the gum-group experienced a reduction in mean stain scores whilst the tablet-group experienced an increase with mean changes of -0.14 and +0.12 respectively, (p?=?0.005, ANCOVA). The change in mean tooth shade scores was statistically significantly greater in the gum-group than in the tablet group at 2 (p?=?0.015), 6 (p?=?0.011) and 12 weeks (p?=?0.003) with greater lightening in the gum-group at each examination period. Conclusion These results support the efficacy of the tested nicotine replacement gum in stain reduction and shade lightening. These findings may help dentists to motivate those wishing to quit smoking using a nicotine replacement gum. Trial registration NCT01440985 PMID:22695211

2012-01-01

392

Gum Tragacanth Fibers from Astragalus gummifer Species: Effects of Influencing Factors on Mechanical Properties of Fibers  

NASA Astrophysics Data System (ADS)

Gum Tragacanth (GT) is one of the most widely used natural gum across the globe and it is shown that GT from Asteragalus gummifer can be processed into fiber via alkaline treatment. In this study a complementary description of GT fibers is provided and the effects of influencing factors on properties of GT fibers investigated. Spinning Dope (SD) prepared by adding ribbon type GT of Astragalus gummifer species to alkaline solutions and fibers produced by solution spinning method. The effects of some processing factors including: draft ratio, residence time in coagulation bath, GT concentration in SD, ripening time of SD, kind of coagulant agent and the pH of washing bath on some mechanical properties of GT fibers studied. It was concluded that with increasing the coagulant concentration the mechanical properties of fibers improved, but it caused formation of sheet core structure. ZnCl2 as coagulant agent improved mechanical properties and applying glycerol caused more flexibility in GT fibers, even though their tenacity reduced.

Khajavi, Ramin; Mossavi Pourgharbi, Seyed Hossein; Kiumarsi, Amir; Rashidi, Abosayeed

393

New intrinsic mechanism on gum-like superelasticity of multifunctional alloys.  

PubMed

Ti-Nb-based Gum Metals exhibit extraordinary superelasticity with ultralow elastic modulus, superior strength and ductility, and a peculiar dislocation-free deformation behavior, most of which challenge existing theories of crystal strength. Additionally, this kind of alloys actually displays even more anomalous mechanical properties, such as the non-linear superelastic behavior, accompanied by a pronounced tension-to-compression asymmetry, and large ductility with a low Poisson's ratio. Two main contradictory arguments exist concerning the deformation mechanisms of those alloys, i.e., formation of reversible nanodisturbance and reversible martensitic transformation. Herein we used the in-situ synchrotron high-energy X-ray scattering technique to reveal the novel intrinsic physical origin of all anomalous mechanical properties of the Ti-24Nb-4Zr-8Sn-0.10O alloy, a typical gum-like metal. Our experiments provide direct evidence on two different kinds of interesting, stress-induced, reversible nanoscale martensitic transitions, i.e., the austenitic regions with B2 structure transform to ?? martensite and those with BCC structure transform to ? martensite. PMID:23831664

Liu, Jia-Peng; Wang, Yan-Dong; Hao, Yu-Lin; Wang, Yunzhi; Nie, Zhi-Hua; Wang, Dong; Ren, Yang; Lu, Zhao-Ping; Wang, Jinguo; Wang, Haoliang; Hui, Xidong; Lu, Ning; Kim, Moon J; Yang, Rui

2013-01-01

394

New intrinsic mechanism on gum-like superelasticity of multifunctional alloys  

PubMed Central

Ti-Nb-based Gum Metals exhibit extraordinary superelasticity with ultralow elastic modulus, superior strength and ductility, and a peculiar dislocation-free deformation behavior, most of which challenge existing theories of crystal strength. Additionally, this kind of alloys actually displays even more anomalous mechanical properties, such as the non-linear superelastic behavior, accompanied by a pronounced tension-to-compression asymmetry, and large ductility with a low Poisson's ratio. Two main contradictory arguments exist concerning the deformation mechanisms of those alloys, i.e., formation of reversible nanodisturbance and reversible martensitic transformation. Herein we used the in-situ synchrotron high-energy X-ray scattering technique to reveal the novel intrinsic physical origin of all anomalous mechanical properties of the Ti-24Nb-4Zr-8Sn-0.10O alloy, a typical gum-like metal. Our experiments provide direct evidence on two different kinds of interesting, stress-induced, reversible nanoscale martensitic transitions, i.e., the austenitic regions with B2 structure transform to ?? martensite and those with BCC structure transform to ? martensite. PMID:23831664

Liu, Jia-Peng; Wang, Yan-Dong; Hao, Yu-Lin; Wang, Yunzhi; Nie, Zhi-Hua; Wang, Dong; Ren, Yang; Lu, Zhao-Ping; Wang, Jinguo; Wang, Haoliang; Hui, Xidong; Lu, Ning; Kim, Moon J.; Yang, Rui

2013-01-01

395

Review: Chios mastic gum: a plant-produced resin exhibiting numerous diverse pharmaceutical and biomedical properties.  

PubMed

Chios mastic gum (CMG) is a resin produced by the plant Pistacia lentiscus var. chia. CMG is used to extract the mastic gum essential oil (MGO). CMG and MGO consist of nearly 70 constituents and have demonstrated numerous and diverse biomedical and pharmacological properties including (a) eradication of bacteria and fungi that may cause peptic ulcers, tooth plaque formation and malodor of the mouth and saliva; (b) amelioration or dramatic reduction of symptoms of autoimmune diseases by inhibiting production of pro-inflammatory substances by activated macrophages, production of cytokines by peripheral blood mononuclear cells in patients with active Crohn's disease, and suppression of production of inflammatory cytokines and chemokines in an asthma model in mice; (c) protection of the cardiovascular system by effectively lowering the levels of total serum cholesterol, low-density lipoprotein and triglycerides in rats, and protection of low-density lipoprotein from oxidation in humans; (d) induction of apoptosis in human cancer cells in vitro and extensive inhibition of growth of human tumors xenografted in immunodeficient mice; and (e) improvement of symptoms in patients with functional dyspepsia. Collectively taken, these numerous and diverse medical and pharmaceutical properties of CMG and MGO warrant further research in an effort to enhance specific properties and identify specific constituent(s) that might be associated with each property. PMID:22949590

Dimas, Konstantinos S; Pantazis, Panayotis; Ramanujam, Rama

2012-01-01

396

GumPack: a personal health assistant with reconfigurable surface components.  

PubMed

Wearable and everyday-carry medical devices can improve quality of life for individuals that need frequent health monitoring. Such tools can supplement ubiquitous home care environments populated with medical sensors, extending the reach of these environments and increasing the freedom of their occupants. This paper presents the concept design for an everyday-carry medical device called a 'GumPack': a small cuboid-shaped device that offers wireless connectivity and plug-and-play surface components, where a component can be a biomedical sensor or a wireless network coordinator that manages a body area network. This geometrical layout optimizes access to surface-based medical hardware mounted on a small form factor. The device offers substantive computing power, supports local component reconfigurability, and promotes interoperability with medical device coordination environments. The GumPack is envisioned to be a personal health assistant carried in a pocket or handbag that can operate alone or interface to, e.g., a cell phone. PMID:23502254

Li, Kejia; Warren, Steve

2013-01-01

397

Catalytic reduction of p-nitrophenol by using platinum nanoparticles stabilised by guar gum.  

PubMed

We report a facile and green method to synthesise highly stable dispersions of platinum nanoparticles (PtNPs) with an average particle size of ? 6 nm. Natural, nontoxic, eco-friendly biopolymer guar gum was utilised as both the reducing and capping agent precursor in aqueous medium. The PtNPs that had been stabilised by guar gum (GG-s-PtNPs) were characterised by UV-vis spectroscopy, XRD, TEM and XPS. GG-s-PtNPs performed better in terms of catalytic activity for the liquid phase reduction of p-nitrophenol (p-NP) compared to p-aminophenol (p-AP). The efficiency of the catalytic reduction of p-NP over GG-s-PtNPs was found to be 97% in a total time of 320 s at room temperature. The mechanisms of the synthesis and catalytic reduction of p-NP are also discussed. The synthesis approach presented here does not require stringent conditions or toxic agents and thus is a straightforward, rapid, efficient, and green approach to the fabrication of highly active catalysts. PMID:25256515

Pandey, Sadanand; Mishra, Shivani B

2014-11-26

398

Healing efficiency of oligosaccharides generated from almond gum (Prunus amygdalus) on dermal wounds of adult rats.  

PubMed

Almond gum is a naturally occurring polymer produced by almond trees and shrubs. Its abundance, as well as its low cost production makes it a potential feedstock for use in food and pharmaceuticals. In this regard, almond gum oligosaccharides were enzymatically generated, purified and their monosaccharide composition assessed using gas chromatography-flame ionization detector. Oligosaccharide analyses show that the most prominent residues were galactose and arabinose with traces of xylose, rhamnose, glucose and mannose. The glycosyl linkage positions were analyzed using gas chromatography - mass spectrometry showing a main chain composed of galactose units [?3)-Gal-(1?] branched mainly with arabinose residues [Ara-(1?]. The potent role of the generated oligosaccharides on rats wound healing was investigated. They have been applied either alone or supplemented, as active substance, with cream formulation, on full-thickness wound created on the dorsum of the rats. The effect of oligosaccharides was assessed by measuring the wound closure percentage, reaching an average of around 100% when applied alone or supplemented to cream formulation. The healing percentage for the control group was only 74.3% at the same day. The histological evaluation of skin sections visualized by light microscopy revealed an improved collagen deposition and an increased fibroblast and vascular densities. PMID:25201790

Bouaziz, Fatma; Ben Romdhane, Molka; Boisset Helbert, Claire; Buon, Laurine; Bhiri, Fatma; Bardaa, Sana; Driss, Dorra; Koubaa, Mohamed; Fakhfakh, Akram; Sahnoun, Zouhair; Kallel, Fatma; Zghal, Najiba; Ellouz Chaabouni, Semia

2014-08-01

399

Potentiality of the "Gum Metal" titanium-based alloy for biomedical applications.  

PubMed

In this study, the "Gum Metal" titanium-based alloy (Ti-23Nb-0.7Ta-2Zr-1.2O) was synthesized by melting and then characterized in order to evaluate its potential for biomedical applications. Thus, the mechanical properties, the corrosion resistance in simulated body fluid and the in vitro cell response were investigated. It was shown that this alloy presents a very high strength, a low Young's modulus and a high recoverable strain by comparison with the titanium alloys currently used in medicine. On the other hand, all electrochemical and corrosion parameters exhibited more favorable values showing a nobler behavior and negligible toxicity in comparison with the commercially pure Ti taken as reference. Furthermore, the biocompatibility tests showed that this alloy induced an excellent response of MC3T3-E1 pre-osteoblasts in terms of attachment, spreading, viability, proliferation and differentiation. Consequently, the "Gum Metal" titanium-based alloy processes useful characteristics for the manufacturing of highly biocompatible medical devices. PMID:25280716

Gordin, D M; Ion, R; Vasilescu, C; Drob, S I; Cimpean, A; Gloriant, T

2014-11-01

400

Evaluation of oleo-gum resin as directly compressible tablet excipient and release retardant.  

PubMed

The present study was designed to study drug release retardant property of myrrh oleo-gum resin from tablets prepared by direct compression method (without binding agent). The tablets were evaluated for various physical tests viz. hardness, friability, tensile strength and drug content. Accelerated stability testing was carried out according to ICH guidelines. Batch F-VII showed 041% friability, 6 kg/cm2 hardness and 0.961 MN/m2 tensile strength. In vitro dissolution studies were performed and different empirical models were applied to drug release data for evaluating the drug release mechanisms and kinetics. A criterion for selecting the most appropriate model was based on linearity (coefficient of correlation). The in vitro release data fit well to the Hixson Crowell model (r2 value ranged from 0.9771 to 0.9945) indicating the drug release mechanism to be surface erosion, effected through water diffusion, polymer hydration, disentanglement and dissolution. In conclusion, myrrh-oleo-gum resin was found to be a suitable directly compressible tablet excipients having release modifying property. PMID:20524434

Kumar, Pradeep; Singh, Inderbir

2010-01-01

401

New intrinsic mechanism on gum-like superelasticity of multifunctional alloys  

NASA Astrophysics Data System (ADS)

Ti-Nb-based Gum Metals exhibit extraordinary superelasticity with ultralow elastic modulus, superior strength and ductility, and a peculiar dislocation-free deformation behavior, most of which challenge existing theories of crystal strength. Additionally, this kind of alloys actually displays even more anomalous mechanical properties, such as the non-linear superelastic behavior, accompanied by a pronounced tension-to-compression asymmetry, and large ductility with a low Poisson's ratio. Two main contradictory arguments exist concerning the deformation mechanisms of those alloys, i.e., formation of reversible nanodisturbance and reversible martensitic transformation. Herein we used the in-situ synchrotron high-energy X-ray scattering technique to reveal the novel intrinsic physical origin of all anomalous mechanical properties of the Ti-24Nb-4Zr-8Sn-0.10O alloy, a typical gum-like metal. Our experiments provide direct evidence on two different kinds of interesting, stress-induced, reversible nanoscale martensitic transitions, i.e., the austenitic regions with B2 structure transform to ?'' martensite and those with BCC structure transform to ? martensite.

Liu, Jia-Peng; Wang, Yan-Dong; Hao, Yu-Lin; Wang, Yunzhi; Nie, Zhi-Hua; Wang, Dong; Ren, Yang; Lu, Zhao-Ping; Wang, Jinguo; Wang, Haoliang; Hui, Xidong; Lu, Ning; Kim, Moon J.; Yang, Rui

2013-07-01

402

Simultaneous determination of five aluminum lake dyes in chewing gum by HPLC with photodiode array detection.  

PubMed

A simple and rapid method has been developed and validated for the determination of five food aluminum lake dyes (Tartrazine Al lake, Sunset Yellow Al lake, Ponceau 4R Al lake, Allura Red Al lake and Brilliant Blue Al lake) in chewing gum. The dye portions of the target aluminum lakes were simultaneous extracted with 0.25 M NaOH and cleaned up by liquid-liquid extraction with dichloromethane, followed by further purification using Oasis WAX solid-phase extraction (SPE) cartridges. Analytes were separated by HPLC using an Inertsil ® ODS-3 column coupled to a photodiode array detector. The amounts of the aluminum lake dyes were finally quantified and indicated as their dye portions using corresponding calibration curves over ranges of 0.5 to 50 µg ml(-1), with correlation coefficients >0.9999. Recoveries of the dye parts in aluminum lake dyes (spiked at levels of 1, 5, 25 µg g(-1)) ranged from 72.5 to 116.4%, with relative standard deviations between 0.9 and 6.5%. Limits of detection and limits of quantification for all analytes were 0.15 and 0.50 µg g(-1), respectively. This method was successfully applied in real samples of chewing gum. PMID:21707267

Yang, Yi; Yin, Jie; Shao, Bing

2011-09-01

403

Kinematics of the ionised gas in Puppis-Vela including the GUM nebula  

NASA Astrophysics Data System (ADS)

We present a high resolution spectroscopic study of the ionized gas in Puppis-Vela, which includes the Gum Nebula and the IRAS Vela Shell, in the emission lines of hydrogen alpha lambda 6563 A, (NII) lambda lambda 6548, 6584 A and the (OIII) lambda 5007 A. Line profiles were obtained at 18 positions well distributed over the entire region. Only the (NII) line profiles in the region of the IRAS Vela Shell show double peaked profiles, consistent with an expansion velocity of 10 +/- 2 km/s. The ionized gas associated with the 36 deg-diameter Gumm Nebula does not show any such systematic motions. This is consistent with, and provides further confirmation of, the results obtained from the IRAS Super Sky Flux (ISSA) maps (Srinivasan Sahu & Blaauw 1993) that the IRAS Vela Shell and the Gum Nebula are two separate structures but seen overlapping in projection. We detected no (OIII) lambda 5007A emission in any of the positions observed. From the (NII)/hydrogen alpha ratio, the temperatures derived at the 18 positions vary between 5,000 to 12,000 K.

Sahu, M. Srinivasan; Sahu, K. C.

1993-12-01

404

Encapsulation of nZVI particles using a Gum Arabic stabilized oil-in-water emulsion.  

PubMed

Stabilization of reactive iron particles against aggregation and sedimentation is a critical engineering aspect for successful application of nZVI (nanoscale zero valent iron) within the contaminated subsurface environment. In this work we explore the stability and reactivity of a new encapsulation approach that relies upon Gum Arabic to stabilize high quantities of nZVI (? 12 g/L) in the dispersed phase of a soybean oil-in-water emulsion. The emulsion is kinetically stable due to substantial repulsive barriers to droplet-droplet induced deformation and subsequent coalescence. Sedimentation time scales were found to be on the order of hours (?=4.77 ± 0.02 h). Thus, the use of Gum Arabic represents an advance in stabilizing nZVI-in-oil-in-water emulsions. nZVI within the emulsion was shown to be reactive with both TCE degradation and H(2) production observed. Degradation rates were observed to be on the same order of magnitude as those reported for less stable, aqueous suspensions of nZVI. TCE consumption within the emulsion was described with an equivalent aqueous phase rate coefficient of ? 5 × 10(-4)L(aq)/m(2)h. PMID:21440368

Long, Tao; Ramsburg, C Andrew

2011-05-30

405

Helping people to stop smoking: randomised comparison of groups being treated with acupuncture and nicotine gum with control group  

E-print Network

Helping people to stop smoking: randomised comparison of groups being treated with acupuncture people to stop smoking are acupuncture1,2 and nicotine gum.3,4 We report the results of a randomised to stop smoking, we had to contact nearly 35 000 smokers to enrol 651 participants. Adults smoking

Paris-Sud XI, Université de

406

Learning Mastery System for "Investigating School Mathematics," Book 3. [Kit Contains Teacher's Manuals, Gummed Stickers, and Duplicator Masters].  

ERIC Educational Resources Information Center

This set of duplicator masters accompanies "Investigating School Mathematics," Book 3 as a supplement to individualize mathematics instruction. The set includes three teacher's manuals, three sets of gummed labels for file folder tabs, and duplicating masters for student record sheets, a home correspondence information letter, and a home…

Southwest Regional Laboratory for Educational Research and Development, Los Alamitos, CA.

407

Effect of emulsifier and guar gum on micro structural, rheological and baking performance of frozen bread dough  

Microsoft Academic Search

The influence of mono- and diacylglycerols esterified to mono- and diacetyltartaric acid (DATEM) and guar gum on dynamic rheological behaviour, starch gelatinization, microstructure and bread properties of frozen dough were analysed. The results obtained showed that the dough freezing and storage at ?18 °C decreased the bread quality. The dough freezing and frozen storage provoked a decrease in the complex

P. D. Ribotta; G. T. Pérez; A. E. León; M. C. Añón

2004-01-01

408

Effect of Guar Gum Polymer and Lime Powder Addition on the Fluid Loss and Rheological Properties of the Bentonite Dispersions  

Microsoft Academic Search

The effects of guar gum polymer and lime powder addition on the fluid loss and rheological properties of bentonite dispersions have been investigated. Eleven different formulations have been prepared according to the American Petroleum Institute procedures and their rheological characteristics have been determined using a rotational viscometer. Four rheological models have been used to describe the pseudoplastic behavior of the

Meisam Mirarab Razi; Majid Ghiass; Fatemeh Mirarab Razi

2012-01-01

409

The free reducing oligosaccharides of angico branco ( Anadenanthera colubrina) gum exudate: an aid for structural assignments in the heteropolysaccharide  

Microsoft Academic Search

A novel method is described for the determination of sequential side-chain structures in the complex, high-arabinose polysaccharide of the gum exudate of angico branco (Anadenantheracolubrina), using as basis the structurally similar reducing oligosaccharides present in small quantities. Of the ten detected, eight were characterized as disaccharides (2, 3, and 9), linear trisaccharides (1 and 4), branched pentasaccharides (5 and 6),

Cirene L. Delgobo; Philip A. J. Gorin; Cesar A. Tischer; Marcello Iacomini

1999-01-01

410

Oral Biochemical Status and Depression of Streptococcus mutans in Children during 24- to 36Month Use of Xylitol Chewing Gum  

Microsoft Academic Search

Plaque and whole saliva samples were collected from initially 11- to 12-year-old children randomly chosen from two groups which participated in a 2- to 3-year field trial designed to test the efficacy of xylitol chewing gums in caries prevention. No initial differences were observed between the groups with regard to the plaque levels of Streptococcus mutans, but at the end

K. K. Mäkinen; E. Söderling; P. Isokangas; J. Tenovuo; J. Tiekso

1989-01-01

411

Quality Attributes of Halva by Utilization of Proteins, Non-hydrogenated Palm Oil, Emulsifiers, Gum Arabic, Sucrose, and Calcium Chloride  

Microsoft Academic Search

Emulsion stability (oil separation) in halva is a major problem that affects quality upon storage. Emulsion instability results in toughness, oil separation, and oil contamination on packaging materials. The objective of this study was to evaluate the effectiveness of improving halva quality by incorporating non-hydrogenated palm oil, glycerol, soy protein concentrate, gelatin, lecithin, pectin, gum Arabic, sugar powder, and calcium

K. I. Ereifej; T. M. Rababah; M. A. Al-Rababah

2005-01-01

412

Effect of nicotine, silver acetate, and ordinary chewing gum in combination with group counselling on smoking cessation  

Microsoft Academic Search

Four hundred and ninety six smokers participated in a randomised comparison of the effect of silver acetate, nicotine, and ordinary chewing gum on smoking cessation. All were motivated to stop smoking abruptly and all had smoked at least 10 cigarettes a day for at least five years. Side effects and taste acceptability were related to outcome after six months. The

E J Jensen; E Schmidt; B Pedersen; R Dahl

1990-01-01

413

Evaluation and Comparison of Changes in Microhardness of Primary and Permanent Enamel on Exposure to Acidic Center-filled Chewing Gum: An in vitro Study  

PubMed Central

ABSTRACT Objectives: The study is to evaluate changes in microhardness of enamel after exposure to acidic center filled chewing gum on primary and permanent teeth. Methods: Thirty primary and 30 permanent molar extracted teeth were painted with acid resistant varnish except a small window over buccal surface. Teeth were divided into four groups according to type of teeth and type of chewing gum (Center fresh and Bubbaloo) (D1, P1, D2 and P2); each tooth was exposed to whole chewing gum mashed with 5 ml of artificial saliva for five minutes at room temperature twice a day for 5 days. After the exposure, teeth were stored in deionized water and submitted for microhardness tests. Results: Paired t-test and independent sample t-test were used for statistical analysis. A significant reduction in microhardness was found between exposed and unexposed areas in all groups. There was no statistically significant difference in reduction of microhardness to chewing gums, and between primary and permanent enamel. Conclusion: There is a definite reduction in microhardness in all groups exposed to chewing gums. Both the chewing gums are equally erosive; both permanent and primary teeth were affected. How to cite this article: Mudumba VL, Muppa R, Srinivas NCH, Kumar DM. Evaluation and Comparison of Changes in Microhardness of Primary and Permanent Enamel on Exposure to Acidic Center-filled Chewing Gum: An in vitro Study. Int J Clin Pediatr Dent 2014;7(1):24-29. PMID:25206233

Muppa, Radhika; Srinivas, NCH; Kumar, Duddu Mahesh

2014-01-01

414

Release properties of chemical and enzymatic crosslinked gelatin-gum Arabic microparticles containing a fluorescent probe plus vetiver essential oil.  

PubMed

Oil-containing gelatin-gum Arabic microparticles were prepared by complex coacervation followed by crosslinking with glutaraldehyde or transglutaminase. A fluorescent mixture, khusimyl dansylate (KD) as the fluorescent compound mixed to the vetiver essential oil, was used as oil model. The effect of the type of crosslinking of the coacervated gelatin-gum Arabic membrane, the physical state of microparticles, wet or freeze-dried and the type of release media, aqueous with surfactants, Sodium Dodecyl Sulphate (sds) or Tween 80 (tw) and anhydrous ethanol as organic media on the release rate of the KD from the microparticles, was experimentally investigated. It was shown that the oil was dispersed uniformly throughout the microparticles and the chemical crosslinked microparticles were more resistant to swelling, presenting smaller sizes after hydration. Also the crosslinking effect, transglutaminase or glutaraldehyde, could be confirmed by the integrity of the crosslinked gelatin-gum Arabic microparticles after incubation in the aqueous sds media, compared to complete dissolution of the uncrosslinked microparticles in this media. The cumulative fluorescent KD release from the gelatin-gum Arabic microparticles decreased in the following order of dissolution media: anhydrous ethanol>tw>sds and the wet microparticles have shown a faster KD release than freeze-dried ones. A mathematical model was used to estimate the diffusion coefficient (D). The chemically crosslinked gelatin-gum Arabic microparticles ensured a pronounced retard effect in the KD diffusion, presenting a D varying from 0.02 to 0.6 x 10(-11)cm(2)/s, mainly in an aqueous media, against D varying from 1.05 to 13.9 x 10(-11)cm(2)/s from the enzymatic crosslinked microparticles. PMID:18835139

Prata, Ana S; Zanin, Maria H A; Ré, Maria I; Grosso, Carlos R F

2008-12-01

415

Land use and land cover classification, changes and analysis in gum Arabic belt in North Kordofan, Sudan  

NASA Astrophysics Data System (ADS)

The gum arabic belt in Sudan plays a significant role in environmental, social and economical aspects. This research was conducted in North Kordofan State, which is affected by modifications in conditions and composition of vegetation cover trends in the gum arabic belt as in the rest of the Sahelian Sudan zone. The objective of the paper is to study the classification, changes and analysis of the land use and land cover in the gum arabic belt in North Kordofan State in Sudan. The study used imageries from different satellites (Landsat and ASTER) and multi-temporal dates (MSS 1972, TM 1985, ETM+ 1999 and ASTER 2007) acquired in dry season. The imageries were geo-referenced and radiometrically corrected by using ENVI-FLAASH software. Image classification (pixel-based) and accuracy assessment were applied. Application of multi-temporal remote sensing data demonstrated successfully the identification and mapping of land use and land cover into five main classes. Forest dominated by Acacia senegal class was separated covering an area of 21% in the year 2007. The obvious changes and reciprocal conversions in the land use and land cover structure indicate the trends and conditions caused by the human interventions as well as ecological impacts on Acacia senegal trees. Also the study revealed that a drastic loss of forest resources occurred in the gum arabic belt in North Kordofan during 1972 to 2007 (25% for Acacia senegal trees). The study concluded that, using of traditional Acacia senegal-based agro-forestry as one of the most successful form in the gum belt.

Adam, Hassan E.; Csaplovics, Elmar; Elhaja, Mohamed E.; El Abbas, Mustafa M.

2013-10-01

416

Chewing gums has stimulatory effects on bowel function in patients undergoing cesarean section: a randomized controlled trial.  

PubMed

The aim of study was to investigate the effect of postoperative gum chewing on the recovery of bowel function after cesarean section. Total 100 women delivered by lower uterine segment section cesarean under local anesthesia (spinal). Eligible patients were randomly allocated into two groups: a gum-chewing group (n=50) or a control group (n= 50). The gum-chewing group participants who received one stick of sugarless gum for one hours, three times daily immediately after recovery from anesthesia and the control group had the usual postoperative care until being discharged. All women were followed up regularly until discharge from hospital, and recorded the times to the ?rst bowel sounds of normal intestinal sounds, the time to the ?rst passage of ?atus, the time to the first feeling of hunger, and the time to the first defecation. The operative data, postoperative tolerance of gum chewing, and postoperative complications were documented. There was no statistically significant difference between the two groups in terms of demographic characteristics such as age, body mass index, parity, duration of surgery, number of miscarriages and curettages, time to the first feeding, the amount of serum intake, and type of cesarean section. The mean average postoperative interval of the first bowel sounds (21.9 versus 26.1 hours, p= 0.016), the first feeling of hunger (11.8 versus 14.5 hours, p= 0.050), the first passage of flatus (24.8 versus 30.0 hours, P=0.002), the first defecation (30.6 versus 38.4 hours, P= 0.0001) was significantly shorter compared to the control group. PMID:23198943

Ledari, Farideh Mohsenzadeh; Barat, Shanaz; Delavar, Mouloud Agajani

2012-11-01

417

Discovering young stars in the Gum 31 region with infrared observations  

NASA Astrophysics Data System (ADS)

Context. The Gum 31 bubble, which contains the stellar cluster NGC 3324, is a poorly studied young region close to the Carina Nebula. Aims: We are aiming to characterise the young stellar and protostellar population in and around Gum 31 and to investigate the star-formation process in this region. Methods: We identified candidate young stellar objects from Spitzer, WISE, and Herschel data. Combining these, we analysed the spectral energy distributions of the candidate young stellar objects. With density and temperature maps obtained from Herschel data and comparisons to a collect-and-collapse scenario for the region we are able to further constrain the characteristics of the region as a whole. Results: We find 661 candidate young stellar objects from WISE data; 91 protostar candidates are detected through Herschel observations in a 1.0° × 1.1° area. Most of these objects are found in small clusters or are well aligned with the H II bubble. We also identify the sources of Herbig-Haro jets. The infrared morphology of the region suggests that it is part of the larger Carina Nebula complex. Conclusions: The location of the candidate young stellar objects on the rim of the H II bubble is suggestive of their being triggered according to a collect-and-collapse scenario, which agrees well with the observed parameters of the region. Some candidate young stellar objects are found in the heads of pillars, which indicates radiative triggering of star formation. All in all, we find evidence that in the region different mechanisms of triggered star formation are at work. Correcting the number of candidate young stellar objects for contamination, we find ~600 young stellar objects in Gum 31 above our completeness limit of about 1 M?. Extrapolating the initial mass function down to 0.1 M?, we estimate a total population of ~5000 young stars for the region. This work is based in part on data collected by Herschel, an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA, and on data observed by VISTA (ESO run number 088.C-0117(A)), an ESO survey telescope developed by a consortium of 18 universities in the United Kingdom, led by Queen Mary, University of London.Tables 1-3 are available in electronic form at http://www.aanda.org

Ohlendorf, H.; Preibisch, T.; Gaczkowski, B.; Ratzka, T.; Ngoumou, J.; Roccatagliata, V.; Grellmann, R.

2013-04-01

418

Gums - swollen  

MedlinePLUS

... dentures or other dental appliances Pregnancy Sensitivity to toothpaste or mouthwash Scurvy Side effect of a drug ... such as mouthwashes, alcohol, and tobacco. Change your toothpaste brand and stop using mouthwashes if sensitivity to ...

419

Bleeding Gums  

MedlinePLUS

... Schueler, MD How it Works Testimonials FAQ for Consumers FAQ for Physicians News Advertising Terms of Use Contact Us Site Map How ... yourself? About Stephen J. Schueler, M.D News Advertising How It Works FAQ for Consumers FAQ for Physicians Testimonials Site Map Terms of ...

420

Apparatus for studying in vitro drug release from medicated chewing gums.  

PubMed

An apparatus for in vitro drug release testing of medicated chewing gums has been developed and is described in detail. The effects on the drug release when varying critical instrumental settings such as the chewing stroke frequency, the distance between the chewing surfaces, the twisting movements of these surfaces and the temperature of the test medium have been thoroughly investigated. It has been shown that the drug release can be tuned to obtain suitable drug release profiles for a number of products: Nicorette((R)) and Nicotinell((R)) (active substance nicotine), Travvell((R)) (dimenhydrinate), V6((R)) (xylitol) and an experimental formulation containing meclizine. The main usage of the present apparatus should be within quality control but the present study has also shown that it may be employed within development pharmaceutics since useful in vivo/in vitro relationships may be obtained due to the versatile settings of the critical instrumental parameters. PMID:10518685

Kvist, C; Andersson, S B; Fors, S; Wennergren, B; Berglund, J

1999-10-28

421

Guar gum and scleroglucan interactions with borax: experimental and theoretical studies of an unexpected similarity.  

PubMed

Guar gum is a galactomannan that assumes a very flexible conformation in solution, while Scleroglucan is a very rigid polysaccharide that dissolves in water as triple helices. Both polymers can form gels in the presence of borax. Despite their structural differences, the freeze-dried gel systems of both polymers, when compressed to form tablets, show a peculiar anisotropic swelling in water that reflects an amazing similarity in terms of their molecular properies. In this paper the behavior of the Guar/borax gel is compared with that of Scleroglucan/borax. The macroscopic properties of the two systems were characterized in terms of rheological measurements. Atomic force microscopy images and molecular dynamics simulation allowed to evaluate, at molecular level, the effect of borax addition to the Guar polymer. Both experiments show that an increasing of the polymer rigidity is produced by borax. The role played by galactose in the side chain was also discussed. PMID:20863102

Bocchinfuso, Gianfranco; Mazzuca, Claudia; Sandolo, Chiara; Margheritelli, Silvia; Alhaique, Franco; Coviello, Tommasina; Palleschi, Antonio

2010-10-21

422

Evaluation of honey locust (Gleditsia triacanthos Linn.) gum as sustaining material in tablet dosage forms.  

PubMed

In this study, honey locust gum (HLG) obtained from Gleditsia triacanthos (honey locust) beans was investigated as a hydrophilic matrix material in the tablets prepared at different concentrations (5% and 10%) by wet granulation method. Theophylline was chosen as a model drug. The matrix tablets containing hydroxyethylcellulose and hydroxypropyl methylcellulose as sustaining polymers at the same concentrations were prepared and a commercial sustained release (CSR) tablet containing 200 mg theophylline was examined for comparison of HLG performance. Physical analysis on CSR tablet, matrix tablets and their granules before compression were performed. According to the results obtained from dissolution studies in distilled water, pH 1.2 HCl buffer and pH 7.2 phosphate buffer, no significant difference was found between CSR tablet and the matrix tablet containing 10% HLG in each medium (P > 0.05) and these tablets showed zero-order kinetic model in all the mediums. PMID:15231434

Uner, Melike; Altinkurt, Turan

2004-07-01

423

Effect of okra gum on the pasting, thermal, and viscous properties of rice and sorghum starches.  

PubMed

The effect of okra gum (OE) on the physical properties of rice and sorghum starches was investigated using rapid visco-analyzer (RVA), Brookfield viscometer, differential scanning Calorimetry (DSC), and light microscopy. Starch was replaced with 5, 10, 15% OE weight basis (g/100 g). In the presence of OE, the peak and final viscosity as well as the setback of both starches were reduced. However, the difference between the theoretical and the measured setback was more than just can be attributed to the omitted starch. The DSC data of the blends showed higher peak temperature compared to the control, indicating slower starch gelatinization in the presence of OE. Brookfield profiles demonstrated increase in shear stress at higher shear rate confirming pseudoplasticity of the system (n<1). Over all, it can be assumed that OE has influenced the properties of the starches, particularly, by decreasing viscosity, setback, and pseudoplasticity of the starch gels. PMID:24750624

Alamri, Mohammed S; Mohamed, Abdellatif A; Hussain, Shahzad

2012-06-01

424

Biopharmaceutical evaluation of diclofenac sodium controlled release tablets prepared from gum karaya--chitosan polyelectrolyte complexes.  

PubMed

The phenomena of polymer interactions and formation of polyelectrolyte complexes (PECs) of oppositely charged polymers have been the focus of interest in fundamental and applied research. Such PECs may possess unique properties that are different from those of individual polymers. In the present study, attempts were made to prepare PECs of negative colloid gum karaya (GK) and positively charged polysaccharide chitosan (CH). The association and factors affecting the interactions between GK and CH were studied by pH and conductivity studies. The dried complexes were characterized by X-ray diffraction, Fourier transformed Infrared (FTIR) Spectroscopy, Scanning Electron Microscopy. The PECs were utilized for encapsulation of diclofenac sodium. Selected polyelectrolyte microparticles were compressed into tablets and were compared with commercial sustained release product Voveran SR®. Positive results of the study indicated the applicability of PECs in the design of oral controlled release drug delivery systems. PMID:22087874

Lankalapalli, Srinivas; Kolapalli, Ramana Murthy

2012-07-01

425

Lepidium perfoliatum seed gum: a new source of carbohydrate to make a biodegradable film.  

PubMed

Microstructural, physical, mechanical and thermal properties of a novel biodegradable film based on Lepidium perfoliatum seed gum (LPSG) were investigated. LPSG films were successfully prepared by incorporation of four levels of glycerol (40%, 50%, 60% and 70%, w/w). As expected, increasing glycerol concentration from 40 to 70% (w/w), increased water vapor permeability (WVP), elongation at break (EB%), moisture content, moisture adsorption and water solubility of LPSG films; whilst, elastic modulus (EM), contact angle, melting point (Tm), enthalpy of melting (?Hm) and glass transition point (Tg) decreased significantly. LPSG films became slightly greenish and yellowish in color but still transparent in appearance. The images taken from electron scanning microscopy indicated uniform surface, compact sheets with no holes or fracture. This study demonstrates that LPSG based films with desired properties can be obtained by adjusting glycerol content. PMID:24299783

Seyedi, Samira; Koocheki, Arash; Mohebbi, Mohebbat; Zahedi, Younes

2014-01-30

426

Semi-dilute galactomannan solutions: observations on viscosity scaling behavior of guar gum  

NASA Astrophysics Data System (ADS)

Based on experimental work involving evaluation of viscosity enhancement of aqueous solutions by high molecular weight guar gum, we have observed that the shear viscosity scaling exponent b for semi-dilute solutions, ?sp ? (c[?])b, is sensitive to molecular weight, being approximately 4.7 for native samples and decreasing progressively as Mw is lowered. The critical overlap parameter demarcating the dilute and semi-dilute regimes also depends on the molecular weight as {{?ft(c[? ]\\right)}*} ? Mw-0.82 . Consequently, viscosity–concentration plots fail to achieve overlap using only specific viscosity and overlap concentration as reducing variables, a commonly accepted empiricism for random-coil polysaccharides. To bridge the gap, we propose to account for water solubility, its temperature dependence and the resulting chain flexibility as additional factors to fully describe the solution behavior of these highly-important raw materials.

Pollard, Michael A.; Fischer, Peter

2014-11-01

427

Microencapsulation of purple Brazilian cherry juice in xanthan, tara gums and xanthan-tara hydrogel matrixes.  

PubMed

The purple Brazilian cherry (Eugenia uniflora L.) juice was encapsulated in xanthan, tara and xanthan-tara hydrogel matrixes. Encapsulation efficiency, Differential Scanning Calorimetry (DSC), X-ray diffractometry, release profile, stability of carotenoids, phenolic compounds and antioxidant activity of microparticles were evaluated. Encapsulation was confirmed. The highest encapsulation efficiency was obtained with xanthan gum and hydrogel was mostly indicated for the release of carotenoids in GFS and IFS medium. Phenolic compounds had the highest release rate but not in a gradually way, regardless of wall material and fluids under analysis. Stored microparticles at 4 and 25 °C, showed carotenoid degradation. Xanthan and hydrogel wall material provided the greatest stability to these compounds. The microparticles' anti-oxidant activity decreased during storage due to the degradation of carotenoids. PMID:24053801

Rutz, Josiane K; Zambiazi, Rui C; Borges, Caroline D; Krumreich, Fernanda D; da Luz, Suzane R; Hartwig, Naralice; da Rosa, Cleonice G

2013-11-01

428

Preparation and properties of organic-inorganic composite superabsorbent based on xanthan gum and loess.  

PubMed

A new, low-cost, and eco-friendly organic-inorganic composite superabsorbent was successfully synthesized in aqueous solution by polymerization xanthan gum (XG), neutralized acrylic acid (AA) and loess using ammonium persulfate (APS) as initiator and N,N-methylenebisacrylamide (MBA) as crosslinker. Structure and morphological characterizations of the composite superabsorbent were investigated by Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The loess content, pH values, surfactants, salts and temperature which could affect the swelling and water-retention capabilities of the composite superabsorbent were investigated. The composite superabsorbent exhibits excellent water absorbency (610 g/g in distilled water), pH-stability (pH 5-10), and higher swelling capacity in anionic surfactant solution; on the other hand, the composite superabsorbent can be used for removing multivalent metal ions. PMID:25037376

Feng, Enke; Ma, Guofu; Wu, Yajuan; Wang, Haiping; Lei, Ziqiang

2014-10-13

429

HI line measurements of pulsars towards the GUM nebula and the Carina arm  

NASA Astrophysics Data System (ADS)

We have observed 21-cm absorption and emission spectra in the direction of seven southern pulsars with the Parkes telescope in order to derive their kinematic distances and to study the interstellar medium. For the first time, we have successfully obtained HI absorption measurements for PSRs J0942-5552, J1048-5832, J1224-6424 and J1401-6357. We have also significantly improved the sensitivity and resolution on PSRs J0738-4042, J0837-4135 and J1157-6224, the spectra of which have been measured previously, and obtained the transverse velocities of PSRs J0837-4135 and J0942-5552 by analysing their scintillation properties. We show that the Taylor & Cordes distance model works reasonably well for pulsars located behind the Gum nebula. Following from our earlier work, we show further evidence for strong deviations from a simple Galactic rotation law in the velocities of the HI gas towards the Carina arm.

Johnston, Simon; Koribalski, Barbel; Weisberg, Joel M.; Wilson, Warwick

1996-03-01

430

Structure and antioxidant activities of sulfated guar gum: homogeneous reaction using DMAP/DCC catalyst.  

PubMed

It was essential to understand the chemical structure of polysaccharides for further research and biochemical or medical application of this natural biopolymer. In the present study, sulfated derivatives of guar gum with high degree of sulfation (DS) were synthesized using 4-dimethylaminopyridine (DMAP)/dimethylcyclohexylcarbodiimide (DCC) as catalyst in homogeneous conditions. The effects of the ratio of chlorosulfuric acid to pyridine, the content of catalyst and reaction temperature were investigated. Results of FT-IR, (1)H and (13)C NMR indicated that C-6 substitution was predominant in sulfated polysaccharide. In the sulfation reaction, a sharp decrease in M(W) was observed. The enhanced antioxidant activities of sulfated polysaccharides were not a function of a single factor but a combination of high DS and low molecule weight. PMID:22484325

Wang, Junlong; Zhao, Baotang; Wang, Xiaofang; Yao, Jian; Zhang, Ji

2012-06-01

431

Formulation and in vitro evaluation of xanthan gum-based bilayered mucoadhesive buccal patches of zolmitriptan.  

PubMed

A novel bilayered mucoadhesive buccal patch of zolmitriptan was prepared using xanthan gum (XG) as mucoadhesive polymer. Hydroxypropyl methylcellulose E-15 was used as film-former and polyvinyl alcohol (PVA) was incorporated, to increase the tensile strength of the patches. To study the effect of independent variables viz. concentrations of XG and PVA, on various dependent variables like in vitro drug release, ex vivo mucoadhesive strength and swelling index, 3(2) factorial design was employed. In vitro drug release studies of optimized formulation showed initially, rapid drug release; 43.15% within 15 min, followed by sustained release profile over 5h. Incorporation of 4% dimethyl sulfoxide enhanced drug permeability by 3.29 folds, transported 29.10% of drug after 5h and showed no buccal mucosal damage after histopathological studies. In conclusion, XG can be used as a potential drug release modifier and mucoadhesive polymer for successful formulation of zolmitriptan buccal patches. PMID:24299896

Shiledar, Rewathi R; Tagalpallewar, Amol A; Kokare, Chandrakant R

2014-01-30

432

Synthesis and flocculation properties of gum ghatti and poly(acrylamide-co-acrylonitrile) based biodegradable hydrogels.  

PubMed

This article reports the development of biodegradable flocculants based on graft co-polymers of gum ghatti (Gg) and a mixture of acrylamide and acrylonitrile co-monomers (AAm-co-AN). The hydrogel polymer exhibited an excellent swelling capacity of 921% in neutral medium at 60°C. The polymer was used to remove saline water from various petroleum fraction-saline water emulsions. The flocculation characteristics of the hydrogel polymer were studied in turbid kaolin solution as a function of the amount of polymer and the solution temperature and pH. Biodegradation studies of hydrogel polymer were conducted using the soil composting method, and the degradation process was constantly monitored using scanning electron microscopy and Fourier transform infrared spectroscopy techniques. The results demonstrated an 89.47% degradation of the polymer after 60 days. Finally, the hydrogel polymer adsorbed 98% of cationic dyes from the aqueous solutions. PMID:25263897

Mittal, Hemant; Jindal, Rajeev; Kaith, Balbir Singh; Maity, Arjun; Ray, Suprakas Sinha

2014-12-19

433

Directly compressible medicated chewing gum formulation for quick relief from common cold  

PubMed Central

Introduction: Common cold is the most frequently recurring disease in the world and is a leading cause of doctor visits and missed days from school and work. Cold reliever medicated chewing gum (MCG) will be a definitive patient acceptable solution for this condition. Anti-allergic, cetirizine (CTZ) is a BCS class-I (highly soluble and highly permeable) non-sedating antihistaminic drug and this study was based on the hypothesis that CTZ as a BCS class I drug will be easily released from chewing gum into the salivary fluid within few minutes of chewing and can be easily permeated from oral mucosa by the pressure created by the chewing action and absorbed to a larger extent into the systemic circulation. Therefore, ultimately patients will get quick relief from symptoms of common cold with greater compliance compared to other conventional dosage forms. Materials and Methods: This study mainly focuses on taste masking of CTZ by inclusion complexation method, its formulation development in the MCG form and its quality and performance evaluation with the study of potential factors affecting drug release by 32 full factorial experimental design. A “chew out” study is carried out to assess in vivo drug release from MCG, in which residual amount is extracted from the chewed sample. Results: Formulation ingredients, such as elastomers, softeners, bulking agents, play an important role in the feel of the final product and its consistency; while sweeteners and flavors play a very essential character in its sensory properties. Conclusion: Interindividual variation in chewing frequency and chewing intensity is the main factor which affects release of active ingredient from MCG; while salivary dilution and involuntary swallowing are main reasons for variability in the absorption site, i.e., either from buccal mucosa or from gastrointestinal tract. PMID:23373003

Chaudhary, Shivang A; Shahiwala, Aliasgar F

2012-01-01

434

Terminalia gum as a directly compressible excipient for controlled drug delivery.  

PubMed

The exudates from the incised trunk of Terminalia randii has been evaluated as controlled release excipient in comparison with xanthan gum and hydroxypropylmethylcellulose (HPMC) using carvedilol (water insoluble) and theophylline (water soluble) as model drugs. Matrix tablets were prepared by direct compression and the effects of polymer concentration and excipients-spray dried lactose, microcrystalline cellulose and dicalcium phosphate dihydrate on the mechanical (crushing strength (CS) friability (F) and crushing strength-friability ratio (CSFR)) and drug release properties of the matrix tablets were evaluated. The drug release data were fitted into different release kinetics equations to determine the drug release mechanism(s) from the matrix tablets. The results showed that the CS and CSFR increased with increase in polymer concentration while F decreased. The ranking of CS and CSFR was HPMC > terminalia > xanthan while the ranking was reverse for F. The ranking for t(25) (i.e. time for 25% drug release) at a polymer concentration of 60% was xanthan > terminalia = HPMC. The dissolution time, t(25), of theophylline matrices was significantly lower (p < 0.001) than those of carvedilol matrix tablets. Drug release from the matrices was by swelling, diffusion and erosion. The mechanical and drug release properties of the tablets were significantly (p < 0.05) dependent on the type and concentration of polymer and excipients used with the release mechanisms varying from Fickian to anomalous. Terminalia gum compared favourably with standard polymers when used in controlled release matrices and could serve as a suitable alternative to the standard polymers in drug delivery. PMID:22068290

Bamiro, Oluyemisi A; Odeku, Oluwatoyin A; Sinha, Vivek R; Kumar, Ruchita

2012-03-01

435

Removal of lead from aqueous solutions using Cassia grandis seed gum-graft-poly(methylmethacrylate).  

PubMed

Using persulfate/ascorbic acid redox system, a series of Cassia grandis seed gum-graft-poly(methylmethacrylate) samples were synthesized. The copolymer samples were evaluated for lead(II) removal from the aqueous solutions where the sorption capacities were found proportional to the grafting extent. The conditions for the sorption were optimized using copolymer sample of highest percent grafting. The sorption was found pH and concentration dependent, pH 2.0 being the optimum value. Adsorption of lead by the grafted seed gum followed a pseudo-second-order kinetics with a rate constant of 4.64 x 10(-5) g/mg/min. The equilibrium data followed the Langmuir isotherm model with maximum sorption capacity of 126.58 mg/g. The influence of electrolytes NaCl, Na(2)SO(4) on lead uptake was also studied. Desorption with 2 N HCl could elute 76% of the lead ions from the lead-loaded copolymer. The regeneration experiments revealed that the copolymer could be successfully reused for at least four cycles though there was a successive loss in lead sorption capacity with every cycle. The adsorbent was also evaluated for Pb(II) removal from battery waste-water containing 2166 mg/L Pb(II). From 1000 times diluted waste water, 86.1% Pb(II) could be removed using 0.05 g/20 ml adsorbent dose, while 0.5 g/20 ml adsorbent dose was capable of removing 60.29% Pb from 10 times diluted waste water. Optimum Pb(II) binding under highly acidic conditions indicated that there was a significant contribution of nonelectrostatic interactions in the adsorption process. A possible mechanism for the adsorption has been discussed. PMID:17719600

Singh, Vandana; Tiwari, Stuti; Sharma, Ajit Kumar; Sanghi, Rashmi

2007-12-15

436

Xanthan gum recovery from fermentation broth using ultrafiltration: Kinetics and process evaluation  

SciTech Connect

Ultrafiltration of xanthan gum solution as an alternative method to alcohol precipitation for xanthan gum recovery from dilute fermentation broth was studied. A polysulfone membrane (with 500,000 MWCO) hollow fiber (106 mil fiber diameter) tubular cartridge was used to concentrate xanthan broth from less than 3 (w/v) % to {approximately}13.5 (w/v) %, with the xanthan recovery yield of {approximately}95 % or higher. During ultrafiltration, the filtrate flux was one order of magnitude lower for xanthan broth than for water, However, the flux remained almost constant for xanthan concentrations up to {approximately}8%. It was then reduced dramatically as the xanthan concentration increased beyond 8%. The reduced filtrate flux was caused by the reduced pumping (shear) rate and higher viscosities at higher xanthan concentrations. At constant xanthan concentration, the filtrate flux remained almost unchanged for the entire period studied, suggesting that the process is not subject to membrane fouling. In general, the filtrate flux decreased with increasing the xanthan concentration and increased with increasing the pumping (shear) rate and the trans-membrane pressure difference. Changing the solution pH had a slight effect on the viscosity of xanthan solution, but did not affect the filtration performance. Even under high-shear-rate conditions, ultrafiltration did not give any adverse effects on the rheological properties and molecular weight of the xanthan polymer. Thus, ultra filtration can be used to concentrate xanthan broth from fermentation by a factor of four or higher and to reduce the subsequent alcohol recovery costs by at least 75 %.

Lo, Y.M.; Yang, S.T.; Min, D.B. [Ohio State Univ., Columbus, OH (United States)

1995-12-01

437

Effect of oil gum massage therapy on common pathogenic oral microorganisms - A randomized controlled trial  

PubMed Central

Objectives: (i) To assess reduction in Streptococcus mutans and Lactobacillus species count in saliva sample after ten minutes of oil gum massage therapy (massage of gingival tissues) per day for three weeks with sesame oil, olive oil, and coconut oil in three different groups of subjects. (ii) To compare the efficacy between three different oils and the “gold standard” chlorhexidine gel. (iii) To assess reduction in gingival scores and plaque scores of study subjects. Materials and Methods: Study design – Single center, parallel design, and triple blind randomized clinical study with four treatment groups. Participants: 32 of the 40 study subjects working as housekeeping personnel at Kasturba Hospital, Manipal; aged 18-55 years completed the three-week study period. Interventions: Subjects were randomly assigned to massage their gingiva everyday for three weeks with sesame oil, olive oil, coconut oil (tests), and Chlorhexidine gel (control). Oral health status and paraffin stimulated saliva samples were obtained at baseline and after three weeks of oil gum massage therapy. Outcome measures: Microbial culture, plaque index, and gingival index. Statistical analysis: Paired t test and Kruskal Wallis test. Results: There was a significant reduction in mean Streptococcus mutans count, Lactobacillus count, plaque scores, and gingival scores in all four groups after the study. However, there was no significant difference found in percentage reduction of these variables between the four groups. Conclusion: These oils can be used as valuable preventive agents in maintaining and improving oral health in low socioeconomic status population. However, it is recommended that further research should be conducted in other populations with a larger sample and longer duration of follow-up period.

Singla, Nishu; Acharya, Shashidhar; Martena, Suganthi; Singla, Ritesh

2014-01-01

438

Immediate Effect of Xylitol Chewing Gum and Mouth Rinse on Salivary Levels of Mutans Streptococci in Adults with Systemic Sclerosis: A Pilot Study  

PubMed Central

Objective To compare the immediate effect of xylitol chewing gum and xylitol mouth rinse on mutans streptococci (MS) levels in the saliva of adults with systemic sclerosis (SSc). Methods Thirteen female adults with SSc were assigned randomly to either the xylitol chewing gum or xylitol mouth rinse groups. Participants in the chewing gum group were given 2 pellets (2.12g) of commercial xylitol chewing gum to chew for 10 min; whereas participants in the mouth rinse group were given 10 ml (10% [w/v]) of xylitol solution to rinse orally for 2 min. MS samples were collected using Dentocult® SM Strip mutans before and after xylitol exposure. Results No significant difference in the change scores of MS levels between the two groups was observed at post xylitol exposure. Conclusions Mouth rinse may provide an alternative mode of xylitol delivery for this population. PMID:24532975

Yuen, Hon K.; Westwater, Caroline; DeGarmo, Justin; Bandyopadhyay, Dipankar

2013-01-01

439

Colonic mucosal tissue energetics and electrolyte transport in dogs fed cellulose, beet pulp or pectin\\/gum arabic as their primary fiber source  

Microsoft Academic Search

Fifteen adult beagle dogs were used to assess the effects of dietary fiber (cellulose, beet pulp and pectin\\/gum arabic) on the canine colonic mucosal DNA content, energetic activity and electrolyte transport systems. The fiber sources were selected according to their relative colonic fermentability (i.e. cellulose is limited, beet pulp is moderate and pectin\\/gum arabic is highly fermentable). Mucosal tissues of

J. E. Hallman; G. A. Reinhart; E. A. Wallace; A. Milliken; E. T. Clemens

1996-01-01

440

Formulation of Gluten-Free Pocket-Type Flat Breads: Optimization of Methylcellulose, Gum Arabic, and Egg Albumen Levels by Response Surface Methodology  

Microsoft Academic Search

Response surface methodology was used to analyze the effects of methyl- cellulose, egg albumen, and gum arabic on the sensory properties of gluten- free pocket-type flat bread baked from formulas based on pregelatinized rice flour and pregelatinized corn starch with corn flour. A rotatable central-composite design consisting of three variables (methylcellulose, egg albumen, and gum arabic), in a five-level pattern

IMAD TOUFEILI; SHAWKY DAGHER; SOSSY SHADAREVIAN

441

Characterization of extremely thermostable enzymatic breakers (?-1,6-galactosidase and ?-1,4-mannanase) from the hyperthermophilic bacterium Thermotoga neapolitana 5068 for hydrolysis of guar gum  

Microsoft Academic Search

An a-galactosidase and a p-mannanase produced by the hyperthermophilic bacterium, Thermotoga neapolitana 5068 (TN50681, separately and together, were evaluated fortheir ability to hydrolyze guar gum in relation toviscos- ity reduction of guar-based hydraulic fracturing fluids used in oil and gas well stimulation. In such applications, premature guar gum hydrolysis at lower temperatures before the fracturing process is completed is undesirable,

Carol M. McCutchen; Guy D. Duffaud; Pascal Leduc; Anja R. H. Petersen; Akash Tayal; Saad A. Khan; Robert M. Kelly

2000-01-01

442

Effect of Chewing Gums Containing Xylitol, Sorbitol or a Mixture of Xylitol and Sorbitol on Plaque Formation, pH Changes and Acid Production in Human Dental Plaque  

Microsoft Academic Search

The aim of the present investigation was to study if xylitol added to a sorbitol-containing chewing gum influenced the pH changes and the acid production activity from sorbitol in plaque. Using a cross-over design, a total of 71 persons were given, 10 times per day for 4 days, three types of chewing gum containing: (1) xylitol; (2) sorbitol, or (3)

V. Topitsoglou; D. Birkhed; L.-Å. Larsson; G. Frostell

1983-01-01

443

Long-Term Effect of Xylitol Chewing Gum in the Prevention of Dental Caries: A Follow-Up 5 Years after Termination of a Prevention Program  

Microsoft Academic Search

About 65% of the original 258 children who participated in 1982–1984 in a caries prevention program involving the use of xylitol chewing gum were retrieved in 1989 for a follow-up study. Ninety-five subjects from the original xylitol (X) group and 70 subjects from the original control (no-gum, C) group were available. In 1984, when the children completed the program at

P. Isogangas; K. K. Mäkinen; J. Tiekso; P. Alanen

1993-01-01

444

Effect of Xylitol and Sorbitol in Chewing-Gums on Mutans Streptococci, Plaque pH and Mineral Loss of Enamel  

Microsoft Academic Search

Seventeen subjects with more than 3 × 105 mutans streptococci per millilitre of saliva completed this randomised, cross-over study. Four different chewing-gums, containing: (1) 70% xylitol, (2) 35% xylitol+ 35% sorbitol, (3) 17.5% xylitol+ 52.5% sorbitol, and (4) 70% sorbitol, were tested. The participants used 12 pieces of each gum per day for 25 days. During the four experimental periods,

K. Wennerholm; J. Arends; D. Birkhed; J. Ruben; C. G. Emilson; A. G. Dijkman

1994-01-01

445

Effect of chewing gums with xylitol, sorbitol and xylitol-sorbitol on the remineralization and hardness of initial enamel lesions in situ  

PubMed Central

Background: The purpose of this study was to determine the effect of three chewing gums and paraffin on the remineralization and the hardness of demineralized enamel. Materials and Methods: A total of 12 subjects wore intraoral palatal appliances with two demineralized bovine enamel slabs. The study consisted of four experimental periods each lasting 21-days, during which subjects were assigned to one of three gum-chewing regimens: gum containing sorbitol, xylitol and a mixture of sorbitol and xylitol and with paraffin as control. The appliances were worn during gum-chewing for 20 min and then retained for 20 min 4 times/day. The slabs were subjected to energy dispersive X-ray spectroscopy analysis and surface microhardness measurements before in setting into the appliance and after the experimental period. The data were subjected to analysis of variance for repeated measures. A P < 0.05 was considered statistically significant. Results: Mineral analysis revealed no significant difference between the baseline and after chewing periods for all groups (P > 0.05). No significant difference was found among the groups either for the baseline measurements or after chewing periods (P > 0.05). All groups showed higher microhardness values after the chewing periods than the baseline except for the Vivident Xylit group (P < 0.05). Conclusion: The chewing of gum had no effect on the Ca/P ratio of demineralized enamel surfaces. The hardening of the demineralized enamel surfaces may vary according to the type of chewing gum.

Tuncer, Duygu; Önen, Alev; Yazici, A. Rüya

2014-01-01

446

In vitro and in vivo evaluation of guar gum matrix tablets for oral controlled release of water-soluble diltiazem hydrochloride.  

PubMed

The objective of the study was to develop guar gum matrix tablets for oral controlled release of water-soluble diltiazem hydrochloride. Matrix tablets of diltiazem hydrochloride, using various viscosity grades of guar gum in 2 proportions, were prepared by wet granulation method and subjected to in vitro drug release studies. Diltiazem hydrochloride matrix tablets containing either 30% wt/wt low-viscosity (LM1), 40% wt/wt medium-viscosity (MM2), or 50% wt/wt high-viscosity (HM2) guar gum showed controlled release. The drug release from all guar gum matrix tablets followed first-order kinetics via Fickian-diffusion. Further, the results of in vitro drug release studies in simulated gastrointestinal and colonic fluids showed that HM2 tablets provided controlled release comparable with marketed sustained release diltiazem hydrochloride tablets (D-SR tablets). Guar gum matrix tablets HM2 showed no change in physical appearance, drug content, or in dissolution pattern after storage at 40 degrees C/relative humidity 75% for 6 months. When subjected to in vivo pharmacokinetic evaluation in healthy volunteers, the HM2 tablets provided a slow and prolonged drug release when compared with D-SR tablets. Based on the results of in vitro and in vivo studies it was concluded that that guar gum matrix tablets provided oral controlled release of water-soluble diltiazem hydrochloride. PMID:16353958

Al-Saidan, Saleh M; Krishnaiah, Yellela S R; Patro, Srinivas S; Satyanaryana, Vemulapalli

2005-01-01

447

Preparation and in-vitro in-vivo evaluation of sustained release matrix diclofenac sodium tablets using PVP-K90 and natural gums.  

PubMed

Conventional dosage form is nowadays mostly replaced by sustained release formulation in order to increase drug efficacy and patient compliance. The sustained release properties of the PVP K90 alone and in combination with guar gum, xanthan gum and gum tragacanth were evaluated using diclofenac sodium (100 mg/tablet) as a model drug. Tablets were processed using wet granulation method and evaluated for sustained drug release properties. The drug release from the formulations was studied in relationship with Commercially available Diclofenac Sodium SR, used as a reference tablets and results were expressed as similarity (f1) and differential factor (f2). The tablets prepared using PVP K90 160 mg/tablet sustained the release of diclofenac sodium for 12 hours. Formulations where the PVP K90 was partially replaced with different gums also sustained the release of drug for 12 hours. The release of the drug from these formulations mainly followed Higuchi model and super case-II and Non-Fickian diffusion. The in-vivo drug release was studied in healthy human volunteers using non-blinded cross over, two period design using Diclofenac Sodium SR Tablets as a reference drug. The relative bioavailability of the formulation containing PVP K90 and gum tragacanth was 0.91. The studies showed that the use of the PVP K90 in combination with gum tragacanth both in-vitro and in-vivo sustained the release of the drug. PMID:21959802

Iqbal, Zafar; Khan, Raza; Nasir, Fazli; Khan, Jamshaid Ali; Rashid, Abdur; Khan, Abbas; Khan, Abad

2011-10-01

448

Distribution of major xanthones in the pericarp, aril, and yellow gum of mangosteen (Garcinia mangostana linn.) fruit and their contribution to antioxidative activity.  

PubMed

Xanthone compounds in mangosteen (Garcinia mangostana Linn.) fruit have been reported to have biological activities including antioxidative and anti-inflammatory effects, and the major xanthone compounds in mangosteen are ?-mangostin and ?-mangostin. The objectives of this research were to quantify and qualify the major xanthones in each part of the mangosteen fruit with and without yellow gum from the point of view of effective utilization of agricultural product. Quantitative evaluation revealed that yellow gum had extremely high amounts of ?-mangostin and ?-mangostin (382.2 and 144.9 mg/g on a wet basis, respectively) followed by pericarp and aril. In mangosteen fruit with yellow gum inside, xanthones seemed to have shifted from the pericarp and to have concentrated in a gum on the surface of aril, and there was almost no difference between the amounts of ?-mangostin and ?-mangostin in whole fruits with and without yellow gum. Pericarp and yellow gum showed much higher radical-scavenging activity and ferric reducing antioxidant potential than the aril. PMID:23649258

Sukatta, Udomlak; Takenaka, Makiko; Ono, Hiroshi; Okadome, Hiroshi; Sotome, Itaru; Nanayama, Kazuko; Thanapase, Warunee; Isobe, Seiichiro

2013-01-01

449

Stabilization of water in oil in water (W/O/W) emulsion using whey protein isolate-conjugated durian seed gum: enhancement of interfacial activity through conjugation process.  

PubMed

The present work was conducted to investigate the effect of purification and conjugation processes on functional properties of durian seed gum (DSG) used for stabilization of water in oil in water (W/O/W) emulsion. Whey protein isolate (WPI) was conjugated to durian seed gum through the covalent linkage. In order to prepare WPI-DSG conjugate, covalent linkage of whey protein isolate to durian seed gum was obtained by Maillard reaction induced by heating at 60 °C and 80% (±1%) relative humidity. SDS-polyacrylamide gel electrophoresis was used to test the formation of the covalent linkage between whey protein isolate and durian seed gum after conjugation process. In this study, W/O/W stabilized by WPI-conjugated DSG A showed the highest interface activity and lowest creaming layer among all prepared emulsions. This indicated that the partial conjugation of WPI to DSG significantly improved its functional characteristics in W/O/W emulsion. The addition of WPI-conjugated DSG to W/O/W emulsion increased the viscosity more than non-conjugated durian seed gum (or control). This might be due to possible increment of the molecular weight after linking the protein fraction to the structure of durian seed gum through the conjugation process. PMID:24060935

Tabatabaee Amid, Bahareh; Mirhosseini, Hamed

2014-01-01

450

Physicochemical responses and microbial characteristics of shiitake mushroom (Lentinus edodes) to gum arabic coating enriched with natamycin during storage.  

PubMed

Physicochemical responses and microbial characteristics of shiitake mushroom (Lentinus edodes) to gum arabic (GA) coating incorporating natamycin (NA) during storage were investigated. Mushroom weight loss, firmness, total soluble solids, total sugar, reducing sugar, ascorbic acid, and microbial and sensory quality were measured. Mushroom coated with gum arabic+natamycin (GANA) maintained tissue firmness and showed reduction in microbial counts from yeasts and moulds compared with the control. In addition, GANA coating also delayed changes in the soluble solids concentration, total sugar and ascorbic acid. Sensory evaluation proved the efficacy of GANA coating by maintaining the overall quality of shiitake mushroom during the storage period. The efficiency was better than that of GA or NA treatment alone. Our study suggests that GANA has the potential to improve the quality of shiitake mushroom and extend its shelf-life up to 16d. PMID:23411335

Jiang, Tianjia; Feng, Lifang; Zheng, Xiaolin; Li, Jianrong

2013-06-01

451

Ca-carboxymethyl xanthan gum mini-matrices: Swelling, erosion and their impact on drug release mechanism.  

PubMed

The effect of Ca(2+) ion concentration on swelling, erosion, and drug release mechanism of Ca(2+) ion cross-linked carboxymethyl xanthan gum (Ca-CMXG) matrices was investigated. By adding CaCl2 solution, carboxymethyl xanthan gum (CMXG) was converted into Ca-CMXG matrix, which was evaluated for swelling, erosion and drug release in different dissolution media. The amount of Ca(2+) ion alters the viscosity of gel layer formed around the matrices resulting in decreased water penetration into swollen layer. The changes in amount of Ca(2+) ion considerably influenced the swelling and erosion of the matrix leading to different drug release profiles. The simultaneous swelling and erosion of matrices that were controlled by the degree of cross-linking prejudiced the drug release mechanism. The release data fitted well into the Korsmeyer-Peppas equation and the combined effect of diffusion and erosion described the overall drug transport mechanism. PMID:24768968

Maity, Siddhartha; Sa, Biswanath

2014-07-01

452

Process development for spray drying of sticky pharmaceuticals; case study of bioadhesive nicotine microparticles for compressed medicated chewing gum.  

PubMed

Spray drying of pharmaceutical compounds with sticky properties is a challenging task and may require substantial time and resources. By including small-scale studies of single droplet drying kinetics a relatively high number of experiments with less material is allowed. This means one can construct a more robust design space according to Quality by Design (QbD) formulation development principles. In the current study we present a case study on the development of spray dried microparticles comprising nicotine bitartrate and hypromellose or alginate polymer, for incorporation into medicated chewing gum. By illustration of initial studies on single droplet drying kinetics, subsequent characterization of microparticles, and final characterization of compressed chewing gum this paper summarizes the entire development process. PMID:23684657

Sander, Camilla; Nielsen, Henrik Stillhof; Søgaard, Susanne Roslev; Støving, Celina; Yang, Mingshi; Jacobsen, Jette; Rantanen, Jukka

2013-08-16

453

Ionotropically Gelled Novel Hydrogel Beads: Preparation, Characterization and In vitro Evaluation  

PubMed Central

Prolonged release drug delivery system of stavudine was made by ionotropic gelation and polyelectrolyte complexation technique. Cross-linking reinforced chitosan-gellan complex beads were prepared by gelation of anionic gellan gum, the primary polymer, with oppositely charged counter ion to form beads which were further complexed with chitosan as a polyelectrolyte. The effect of this polymer on release profile of drug was studied. Beads without chitosan complexation were also made. The reaction of chitosan-gellan complex dominates the formation of skin layer on the surface of beads. Stavudine an antiretroviral drug was selected as novel drug for the experiment. The final formulations were subjected to in vitro evaluation and several characterization studies. Batches with gellan gum shows Higuchi model, while chitosan-gellan shows zero order release. All the batches with copolymer showed sustained the drug release more than 12 h, whereas with gellan gum alone showed up to 10 h. Batches with chitosan showed maximum drug encapsulation efficiency. PMID:22923862

Patil, J. S.; Kamalapur, M. V.; Marapur, S. C.; Shiralshetti, S. S.

2011-01-01

454

The effect of acacia gum and a water-soluble dietary fiber mixture on blood lipids in humans.  

PubMed

Water-soluble dietary fibers (WSDF) are generally thought to lower cholesterol. This study compared the cholesterol-lowering effects of a medium viscosity WSDF mixture (psyllium, pectin, guar gum and locust bean gum) with an equal amount of WSDF from acacia gum, which has a lower viscosity. Hypercholesterolemic males (n = 13) and females (n = 16) were randomly assigned to one of two WSDF treatments provided in a low-calorie powder form for mixing into beverages (< 4 kcal/serving). Subjects were instructed to mix powders into their usual beverages and to consume them three times daily (5 g WSDF/serving) for 4 weeks while consuming their typical fat-modified diets. Exercise and body weights were also held constant. The WSDF mixture yielded a 10% decrease in plasma total cholesterol (from 251 +/- 20 to 225 +/- 19 mg/dL; p < 0.01), and a 14% reduction in low-density lipoprotein cholesterol (from 167 +/- 14 to 144 +/- 14 mg/dL; p < 0.001). No significant changes in plasma high-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol or triglycerides were observed. In contrast, the acacia gum-treated group showed no change in any plasma lipid parameters. The WSDF treatments did not produce significant changes in mean dietary intakes within or between treatment groups. These data support previous findings that a diet rich in select WSDF can be a useful cholesterol-lowering adjunct to a fat-modified diet, but that caution should be exercised in ascribing cholesterol-lowering efficacy to dietary fibers based solely on their WSDF classification. Finally, WSDF viscosity is a potential cholesterol-lowering factor to be explored further. PMID:8385164

Jensen, C D; Spiller, G A; Gates, J E; Miller, A F; Whittam, J H

1993-04-01

455