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1

Degradation of Carbazole by Microbial Cells Immobilized in Magnetic Gellan Gum Gel Beads?  

PubMed Central

Polycyclic aromatic heterocycles, such as carbazole, are environmental contaminants suspected of posing human health risks. In this study, we investigated the degradation of carbazole by immobilized Sphingomonas sp. strain XLDN2-5 cells. Four kinds of polymers were evaluated as immobilization supports for Sphingomonas sp. strain XLDN2-5. After comparison with agar, alginate, and ?-carrageenan, gellan gum was selected as the optimal immobilization support. Furthermore, Fe3O4 nanoparticles were prepared by a coprecipitation method, and the average particle size was about 20 nm with 49.65-electromagnetic-unit (emu) g?1 saturation magnetization. When the mixture of gellan gel and the Fe3O4 nanoparticles served as an immobilization support, the magnetically immobilized cells were prepared by an ionotropic method. The biodegradation experiments were carried out by employing free cells, nonmagnetically immobilized cells, and magnetically immobilized cells in aqueous phase. The results showed that the magnetically immobilized cells presented higher carbazole biodegradation activity than nonmagnetically immobilized cells and free cells. The highest biodegradation activity was obtained when the concentration of Fe3O4 nanoparticles was 9 mg ml?1 and the saturation magnetization of magnetically immobilized cells was 11.08 emu g?1. Additionally, the recycling experiments demonstrated that the degradation activity of magnetically immobilized cells increased gradually during the eight recycles. These results support developing efficient biocatalysts using magnetically immobilized cells and provide a promising technique for improving biocatalysts used in the biodegradation of not only carbazole, but also other hazardous organic compounds.

Wang, Xia; Gai, Zhonghui; Yu, Bo; Feng, Jinhui; Xu, Changyong; Yuan, Yong; Lin, Zhixin; Xu, Ping

2007-01-01

2

21 CFR 172.665 - Gellan gum.  

Code of Federal Regulations, 2010 CFR

... 3 2009-04-01 2009-04-01 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...

2009-04-01

3

21 CFR 172.665 - Gellan gum.  

Code of Federal Regulations, 2010 CFR

... 3 2010-01-01 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...

2010-01-01

4

Degradation of Carbazole by Microbial Cells Immobilized in Magnetic Gellan Gum Gel Beads  

Microsoft Academic Search

Polycyclic aromatic heterocycles, such as carbazole, are environmental contaminants suspected of posing human health risks. In this study, we investigated the degradation of carbazole by immobilized Sphingomonas sp. strain XLDN2-5 cells. Four kinds of polymers were evaluated as immobilization supports for Sphingomonas sp. strain XLDN2-5. After comparison with agar, alginate, and -carrageenan, gellan gum was selected as the optimal immobilization

Xia Wang; Zhonghui Gai; Bo Yu; Jinhui Feng; Changyong Xu; Yong Yuan; Zhixin Lin; Ping Xu

2007-01-01

5

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

2012-11-21

6

Optimizing gelling parameters of gellan gum for fibrocartilage tissue engineering.  

PubMed

Gellan gum is an attractive biomaterial for fibrocartilage tissue engineering applications because it is cell compatible, can be injected into a defect, and gels at body temperature. However, the gelling parameters of gellan gum have not yet been fully optimized. The aim of this study was to investigate the mechanics, degradation, gelling temperature, and viscosity of low acyl and low/high acyl gellan gum blends. Dynamic mechanical analysis showed that increased concentrations of low acyl gellan gum resulted in increased stiffness and the addition of high acyl gellan gum resulted in greatly decreased stiffness. Degradation studies showed that low acyl gellan gum was more stable than low/high acyl gellan gum blends. Gelling temperature studies showed that increased concentrations of low acyl gellan gum and CaCl? increased gelling temperature and low acyl gellan gum concentrations below 2% (w/v) would be most suitable for cell encapsulation. Gellan gum blends were generally found to have a higher gelling temperature than low acyl gellan gum. Viscosity studies showed that increased concentrations of low acyl gellan gum increased viscosity. Our results suggest that 2% (w/v) low acyl gellan gum would have the most appropriate mechanics, degradation, and gelling temperature for use in fibrocartilage tissue engineering applications. PMID:21604364

Lee, Haeyeon; Fisher, Stephanie; Kallos, Michael S; Hunter, Christopher J

2011-05-20

7

Photocrosslinkable gellan gum film as an anti-adhesion barrier.  

PubMed

The purpose of this study was to develop a gellan gum-based film which could be photocrosslinked for medical applications. Gellan gum was grafted with cinnamate to yield the photo crosslinkable polymer (gellan gum-cin). This material had 14.7% of its D-galacturonic residues reacted with cinnamate groups and displayed maximum absorption at 254 nm. Investigation of the photochemical properties showed that the crosslinking efficiency was 82% after 16 min of UV irradiation. The anti-adhesion films prepared from gellan gum-cin polymers exhibited high gel contents (88 2%) and suitable mechanical properties. When implanted into rats, the gellan gum-cin film exhibited the most promising anti-adhesion potential in 2 out of 10 rats without forming any tissue adhesion. Furthermore, the gellan gum-cin film could effectively inhibit inflammation in rats based on the results of fluid leukocyte analyses. The gellan gum-cin film thus has potential in clinical applications. PMID:22840050

Lee, Ming-Wei; Tsai, Hui-Fang; Wen, Shu-Min; Huang, Chia-Hui

2012-06-29

8

Preparation and Evaluation of Soft Gellan Gum Gel Containing Paracetamol  

PubMed Central

The objective of this study was to develop soft paracetamol gel using gellan gum as a gelling agent and sodium citrate as a source of cation. Different batches were prepared using three different concentrations of gellan gum (0.1, 0.3, and 0.5%), each with two different sodium citrate concentrations (0.3 and 0.5%). The consistency of the paracetamol gel was dependent on the concentration of gellan gum, sodium citrate and co-solute. The results of dissolution study of soft gel containing 0.3% gellan gum and 0.3% sodium citrate revealed that paracetamol was completely released in 30 min. Polyethylene glycol 400 worked as a solubilizer for paracetamol. All the gels possessed acceptable sensory characteristics when evaluated by human volunteers. Short term stability study carried out for four weeks at different temperatures revealed no considerable changes in performance characteristics of developed optimized formulation.

Gohel, M. C.; Parikh, R. K.; Nagori, S. A.; Shah, S. N.; Dabhi, M. R.

2009-01-01

9

Gellan gum-based hydrogels for intervertebral disc tissue-engineering applications.  

PubMed

Intervertebral disc (IVD) degeneration is a challenging clinical problem that urgently demands viable nucleus pulposus (NP) implant materials. The best suited biomaterial for NP regeneration has yet to be identified, but it is believed that biodegradable hydrogel-based materials are promising candidates. In this work, we have developed ionic- and photo-crosslinked methacrylated gellan gum (GG-MA) hydrogels to be used in acellular and cellular tissue-engineering strategies for the regeneration of IVDs. The physicochemical properties of the developed hydrogels were investigated by Fourier-transform infrared spectroscopy, (1) H nuclear magnetic resonance and differential scanning calorimetry. The swelling ability and degradation rate of hydrogels were also analysed in phosphate-buffered saline solution at physiological pH for a period of 30 days. Additionally, the morphology and mechanical properties of the hydrogels were assessed under a scanning electron microscope and dynamic compression, respectively. An in vitro study was carried out to screen possible cytotoxicity of the gellan gum-based hydrogels by culturing rat lung fibroblasts (L929 cells) with hydrogel leachables up to 7 days. The results demonstrated that gellan gum was successfully methacrylated. We observed that the produced GG-MA hydrogels possess improved mechanical properties and lower water uptake ability and degradation rate as compared to gellan gum. This work also revealed that GG-MA hydrogels are non-cytotoxic in vitro, thus being promising biomaterials to be used in IVD tissue-engineering strategies. PMID:21604382

Silva-Correia, J; Oliveira, J M; Caridade, S G; Oliveira, J T; Sousa, R A; Mano, J F; Reis, R L

2010-12-29

10

An insight into the emerging exopolysaccharide gellan gum as a novel polymer.  

PubMed

The microbial exopolysaccharides are water-soluble polymers secreted by microorganisms during fermentation. The biopolymer gellan gum is a relatively recent addition to the family of microbial polysaccharides that is gaining much importance in food, pharmaceutical and chemical industries due to its novel properties. It is commercially produced by C.P. Kelco in Japan and the USA. This article presents a critical review of the available information on the gum synthesized by Sphingomonas paucimobilis with special emphasis on its fermentative production. Factors affecting the fermentative production of gellan gum and problems associated with mass transfer have been addressed. Classification and trade names of gellan gum has been specified. Characteristics of gellan gum with respect to its structure, physicochemical properties are discussed. An attempt has also been made to review the current and potential applications of gellan gum in food, pharmaceutical and other industries. PMID:23499110

Prajapati, Vipul D; Jani, Girish K; Zala, Bhumi S; Khutliwala, Tohra A

2013-01-21

11

Genome sequence of Sphingomonas elodea ATCC 31461, a highly productive industrial strain of gellan gum.  

PubMed

The commercial gelling agent gellan gum is a heteropolysaccharide produced by Sphingomonas elodea ATCC 31461. However, the genes involved in the biosynthesis, regulation, and modification of gellan gum have not been fully characterized. Here we describe the draft genome sequence of stain ATCC 31461 and major findings from its annotation. PMID:22123766

Gai, Zhonghui; Wang, Xia; Zhang, Xiaoyun; Su, Fei; Wang, Xiaoyu; Tang, Hongzhi; Tai, Cui; Tao, Fei; Ma, Cuiqing; Xu, Ping

2011-12-01

12

Genome Sequence of Sphingomonas elodea ATCC 31461, a Highly Productive Industrial Strain of Gellan Gum  

PubMed Central

The commercial gelling agent gellan gum is a heteropolysaccharide produced by Sphingomonas elodea ATCC 31461. However, the genes involved in the biosynthesis, regulation, and modification of gellan gum have not been fully characterized. Here we describe the draft genome sequence of stain ATCC 31461 and major findings from its annotation.

Gai, Zhonghui; Wang, Xia; Zhang, Xiaoyun; Su, Fei; Wang, Xiaoyu; Tang, Hongzhi; Tai, Cui; Tao, Fei; Ma, Cuiqing; Xu, Ping

2011-01-01

13

Preparation and evaluation of collagen I/ gellan Gum/?-TCP microspheres as bone graft substitute materials.  

PubMed

Collagen I is the main component of protein in bone and exhibits many excellent applications in biomedical fields. Gellan gum possesses good biocompatible, biodegradable and good mechanical property, and shows great potentials as tissue engineering scaffold or cell culture substrate. Therefore, the aim of this study was to use collagen I, gellan gum and ?-TCP to prepare collagen I/gellan gum/?-TCP microspheres by emulsion method as bone graft substitute materials. The preliminary results showed that collagen I/gellan gum/?-TCP microspheres had particle size distribution between 500-1000 P in diameter and exhibited better mechanical strength. These microspheres also showed good biocompatibility in cell activity test. PMID:24111272

Ku, Kai-Chi; Lee, Ming-Wei; Kuo, Shyh Ming; Yao, Chun-Hsu; Chang, Shwu-Jen

2013-07-01

14

Effects of sugar on the sol-gel transition in gellan gum aqueous solutions  

Microsoft Academic Search

The effects of glucose, fructose, sucrose and trehalose on the sol-gel transition in gellan gum aqueous solutions have been\\u000a studied using rheological measurements and differential scanning calorimetry (DSC). Thermal scanning rheological results suggested\\u000a that a 1 % gellan gum solution without sugar could not form a gel even on cooling to 0 C; however, on addition of any sugar\\u000a at

E. Miyoshi; K. Nishinari

15

A semi-fluid gellan gum medium improves nematode toxicity testing  

Microsoft Academic Search

This study examined an alternative test medium for nematodes that use gellan gum as the gelling agent instead of agar. The semi-fluid consistency of the gel-like component nematode growth gellan gum (CNGG) supports three-dimensional distribution of the nematodes and food bacteria, but still allows free movement of the former. Moreover, flexible preparation of the medium and easy recovery of the

Marvin Brinke; Peter Heininger; Walter Traunspurger

2011-01-01

16

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

PubMed

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. PMID:23880566

Chen, Roland K; Shih, A J

2013-07-24

17

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

2013-06-03

18

Gellan gum capped silver nanoparticle dispersions and hydrogels: cytotoxicity and in vitro diffusion studies  

NASA Astrophysics Data System (ADS)

The preparation of highly stable water dispersions of silver nanoparticles using the naturally available gellan gum as a reducing and capping agent is reported. Further, exploiting the gel formation characteristic of gellan gum silver nanoparticle incorporated gels have also been prepared. The optical properties, morphology, zeta potential and long-term stability of the synthesized silver nanoparticles were investigated. The superior stability of the gellan gum-silver nanoparticle dispersions against pH variation and electrolyte addition is revealed. Finally, we studied the cytotoxicity of AgNP dispersions in mouse embryonic fibroblast cells (NIH3T3) and also evaluated the in vitro diffusion of AgNP dispersions/gels across rat skin.The preparation of highly stable water dispersions of silver nanoparticles using the naturally available gellan gum as a reducing and capping agent is reported. Further, exploiting the gel formation characteristic of gellan gum silver nanoparticle incorporated gels have also been prepared. The optical properties, morphology, zeta potential and long-term stability of the synthesized silver nanoparticles were investigated. The superior stability of the gellan gum-silver nanoparticle dispersions against pH variation and electrolyte addition is revealed. Finally, we studied the cytotoxicity of AgNP dispersions in mouse embryonic fibroblast cells (NIH3T3) and also evaluated the in vitro diffusion of AgNP dispersions/gels across rat skin. Electronic supplementary information (ESI) available: Time dependent UV-Vis spectral studies revealing the stability of AgNP dispersions and agar plate images displaying the antibacterial activity of AgNPs. See DOI: 10.1039/c1nr10957j

Dhar, S.; Murawala, P.; Shiras, A.; Pokharkar, V.; Prasad, B. L. V.

2012-01-01

19

Effects of divalent cations on drug encapsulation efficiency of deacylated gellan gum.  

PubMed

The objective of this research was to evaluate the effects of various divalent cations on the encapsulation efficiency of gellan gum and to probe the underlying mechanisms responsible for drug-loading efficiency. Spherical beads containing azathioprine were prepared from deacetylated gellan gum by ionotropic gelation method. One molar solution of various divalent chlorides (MgCl(2), BaCl(2), CaCl(2), CuCl(2) and ZnCl(2)) and two additional concentrations of CaCl(2) (2.5 M and 5.0 M) were used as ionotropic media. Drug solubility was also determined in these ionotropic media and statistically evaluated using ANOVA. Solubility in various divalent chloride solutions (1.0 M) suggests that azathioprine forms complex with Ca(2+), Zn(2+) and Cu(2+), while there might be a formation of poorly water-soluble chelates with Mg(2+) and Ba(2+) as solubility in these media were less than in deionized water. The encapsulation efficiency of gellan gum was much higher in the presence of transition elements (Cu(2+) and Zn(2+)) when compared to alkaline earth metal ions (Ca(2+), Mg(2+) and Ba(2+)). Higher concentrations of Ca(2+) decreased the encapsulation efficiency of gellan gum in a nearly proportional manner. The correlation between encapsulation efficiency and pH of the ionotropic media was negative and significant (r=-0.9574, p<0.05), although the solubility of azathioprine seems to be independent of the pH of the ionotropic medium. Overall, the results suggest that drug encapsulation efficiency of deacetylated gellan gum is largely affected by the concentration and nature of various divalent cations (e.g. atomic number, valency or electro-positivity, co-ordination property, etc.) and pH of the ionotropic medium. PMID:16421086

Singh, Brahma N; Kim, Kwon H

2005-11-01

20

Biocompatible gellan gum-reduced gold nanoparticles: cellular uptake and subacute oral toxicity studies.  

PubMed

Currently gold nanoparticles are being explored for drug delivery and other biomedical applications; therefore it is necessary to study the fate of such nanoparticles inside the body. The objective of the present study was to investigate the cellular uptake and toxicity of the gold nanoparticles synthesized using a microbial polysaccharide, gellan gum, as a capping and reducing agent. The cellular uptake of gold nanoparticles was studied on mouse embryonic fibroblast cells, NIH3T3 and human glioma cell line, LN-229. The cellular uptake study indicated that the gellan gum-reduced gold nanoparticles were located in cancer cells (LN-229) while no uptake was observed in normal mouse embryonic fibroblast cells (NIH3T3). The toxicity of the gold nanoparticles was evaluated by carrying out subacute 28 day oral toxicity studies in rats. Subacute administration of gum-reduced gold nanoparticles to the rats did not show any hematological or biochemical abnormalities. The weight and normal architecture of various organs did not change compared with control. The current findings, while establishing the specific uptake of nanoparticles into cancerous cells, also demonstrates that the gellan gum-reduced gold nanoparticles are devoid of toxicity in animals following oral administration. PMID:21089158

Dhar, Sheetal; Mali, Vishal; Bodhankar, Subhash; Shiras, Anjali; Prasad, B L V; Pokharkar, Varsha

2010-11-19

21

The effect of deacetylated gellan gum on aesculin distribution in the posterior segment of the eye after topical administration.  

PubMed

The aim of the present work was to evaluate the effect of deacetylated gellan gum on delivering hydrophilic drug to the posterior segment of the eye. An aesculin-containing in situ gel based on deacetylated gellan gum (AG) was prepared and characterized. In vitro corneal permeation across isolated rabbit cornea of aesculin between AG and aesculin solution (AS) was compared. The results showed that deacetylated gellan gum promotes corneal penetration of aesculin. Pharmacokinetics and ocular tissue distribution of aesculin after topical administration in rabbit eye showed that AG greatly improved aesculin accumulation in posterior segmentsrelative to AS, which was probably attributed to conjunctivital/sclera pathway. The area-under-the-curve (AUC) for AG in aqueous humor, choroid-retina, sclera and iris-ciliary body were significantly larger than those of AS. AG can be used as a potential carrier for broading the application of aesculin. PMID:22643053

Chen, Qiuhong; Zheng, Yu; Li, Ye; Zeng, Ying; Kuang, Jianchao; Hou, Shixiang; Li, Xiaohui

2012-05-01

22

Cloning and knockout of phytoene desaturase gene in Sphingomonas elodea ATCC 31461 for economic recovery of gellan gum.  

PubMed

A gene encoding phytoene desaturase (crtI) in the carotenoid biosynthetic pathway of Sphingomonas elodea ATCC 31461, an industrial gellan gum-producing strain, was cloned and identified. This gene is predicted to encode a 492-amino acid protein with significant homology to the phytoene desaturase of other carotenogenic organisms. Knockout of crtI gene blocked yellow carotenoid pigment synthesis and resulted in the accumulation of colorless phytoene, confirming that it encodes phytoene desaturase. Further research indicates that the yield of gellan gum production by crtI gene knockout mutants is almost the same as that by the wild-type strain. In addition, a recovery method based on the colorless fermentation broth of the crtI gene knockout mutant was investigated. Compared to the volume of alcohol for the parent strain, much less alcohol (30%) is required in this recovery process; thus, the costs of downstream purification of gellan gum can be substantially reduced. PMID:21229377

Zhu, Liang; Wu, Xuechang; Li, Ou; Chen, Yamin; Qian, Chaodong; Teng, Yi; Tao, Xianglin; Gao, Haichun

2011-01-13

23

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

2013-03-17

24

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

2013-03-13

25

Biological evaluation of intervertebral disc cells in different formulations of gellan gum-based hydrogels.  

PubMed

Gellan gum (GG)-based hydrogels are advantageous in tissue engineering not only due to their ability to retain large quantities of water and provide a similar environment to that of natural extracellular matrix (ECM), but also because they can gelify in situ in seconds. Their mechanical properties can be fine-tuned to mimic natural tissues such as the nucleus pulposus (NP). This study produced different formulations of GG hydrogels by mixing varying amounts of methacrylated (GG-MA) and high-acyl gellan gums (HA-GG) for applications as acellular and cellular NP substitutes. The hydrogels were physicochemically characterized by dynamic mechanical analysis. Degradation and swelling abilities were assessed by soaking in a phosphate buffered saline solution for up to 170 h. Results showed that as HA-GG content increased, the modulus of the hydrogels decreased. Moreover, increases in HA-GG content induced greater weight loss in the GG-MA/HA-GG formulation compared to GG-MA hydrogel. Potential cytotoxicity of the hydrogel was assessed by culturing rabbit NP cells up to 7 days. An MTS assay was performed by seeding rabbit NP cells onto the surface of 3D hydrogel disc formulations. Viability of rabbit NP cells encapsulated within the different hydrogel formulations was also evaluated by Calcein-AM and ATP assays. Results showed that tunable GG-MA/HA-GG hydrogels were non-cytotoxic and supported viability of rabbit NP cells. Copyright 2012 John Wiley & Sons, Ltd. PMID:23225767

Khang, G; Lee, Sk; Kim, Hn; Silva-Correia, J; Gomes, Me; Viegas, Caa; Dias, Ir; Oliveira, Jm; Reis, Rl

2012-12-01

26

Gellan gum-PEI nanocomposites as efficient gene delivery agents.  

PubMed

Of the non-viral vectors, a cationic polymer like PEI is an attractive candidate which however, has been negatively impacted due to its marked toxicity. An anionic sugar polymer gelan gum (GG) has been introduced into PEI system to increase transfection efficiency with minimal toxicity. We showed that one of the synthesized (GP1-GP6) GG-PEI nanocomposites (NCs), GP3, exhibited negligible toxicity in in vitro (primary keratinocytes, HEK293, HeLa and HepG2 cells) and in vivo (Drosophila melanogaster) as compared to PEI or lipofectamin. GP3-pDNA complex was found to be transfected efficiently in the above cells as confirmed by FACS analysis (72.0 + 5.5%) while lipofectamine showed only 12.4 + 3.5% efficiency. GP3 mediated GFP specific siRNA delivery resulted in the knockdown of the GFP expression by approximately 77% and JNK (60%). In vivo gene expression studies in mice revealed reporter gene expression in spleen. The study demonstrates that GG blended PEI NCs hold promise for future applications in gene delivery both in vitro and in vivo. PMID:21485792

Goyal, Ritu; Tripathi, S K; Tyagi, S; Ram, K Ravi; Ansari, K M; Kumar, P; Shukla, Y; Chowdhuri, D Kar; Gupta, K C

2011-02-01

27

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

2009-03-13

28

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.

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

2009-01-01

29

Effect of sugars, amino acids, and culture technique on maturation of somatic embryos of Pinus strobus on medium with two gellan gum concentrations  

Microsoft Academic Search

Maturation of five embryogenic lines of Pinus strobus L. was tested on media with various sugars and sources of organic nitrogen, and solidified with two gellan gum concentrations\\u000a (0.6 and 1.0%). Mature somatic embryo production was more abundant at 1.0% gellan gum than at 0.6%. Complex combinations of\\u000a amino acids had little effect on mature embryo production of most tested

lisabeth Garin; Michle Bernier-Cardou; Nathalie Isabel; Krystyna Klimaszewska; Ariane Plourde

2000-01-01

30

Preparation of polymer gel dosimeters based on less toxic monomers and gellan gum  

NASA Astrophysics Data System (ADS)

New polymer gel dosimeters consisting of 2-hydroxyethyl methacrylate (HEMA), triethylene glycol monoethyl ether monomethacrylate (TGMEMA), polyethylene glycol 400 dimethacrylate (9G), tetrakis (hydroxymethyl) phosphonium chloride as an antioxidant, and gellan gum as a gel matrix were prepared. They were optically analyzed by measuring absorbance to evaluate a dose response. The absorbance of the polymer gel dosimeters that were exposed to 60Co ?-rays increased with increasing dose. The dosimeters comprising HEMA and 9G showed a linear increase in absorbance in the dose range from 0 to 10 Gy. The dose response depended on the 9G concentration. For others comprising HEMA, 9G and TGMEMA, the absorbance of the polymer gel dosimeters drastically increased above a certain dose, and then leveled off up to 10 Gy. The optical variations in these polymer gel dosimeters were also induced by x-irradiation from Cyberknife radiotherapy equipment. Furthermore, the exposed region of the latter polymer gel dosimeter exhibited a thermo-responsive behavior.

Hiroki, A.; Sato, Y.; Nagasawa, N.; Ohta, A.; Seito, H.; Yamabayashi, H.; Yamamoto, T.; Taguchi, M.; Tamada, M.; Kojima, T.

2013-10-01

31

Brevifollis gellanilyticus gen. nov., sp. nov., a gellan-gum-degrading bacterium of the phylum Verrucomicrobia.  

PubMed

The taxonomic properties of strain DC2c-G4(T), a Gram-staining-negative, ovoid, gellan-gum-degrading bacterial isolate, were examined. Phylogenetic analysis based on 16S rRNA gene sequences identified this isolate as a member of the phylum Verrucomicrobia and closest to the genus Prosthecobacter. The 16S rRNA gene sequence similarities between this isolate and any of the type strains of species of the genus Prosthecobacter were less than 95 %. In addition, the absence of a single prostheca and the predominant menaquinone MK-7(H2) supported the differentiation of this isolate from the genus Prosthecobacter. Here, we propose Brevifollis gellanilyticus gen. nov., sp. nov. to accommodate the isolate. The type strain of the type species is DC2c-G4(T) (= NBRC 108608(T) = CIP 110457(T)). PMID:23416572

Otsuka, Shigeto; Suenaga, Taku; Vu, Hoan Thi; Ueda, Hiroyuki; Yokota, Akira; Senoo, Keishi

2013-02-15

32

Physicochemical studies of glucose, gellan gum, and hydroxypropyl cellulose--inhibition of cast iron corrosion.  

PubMed

Glucose, gellan gum, and hydroxypropyl cellulose were studied against the acid corrosion of cast iron by means of weight loss, potentiodynamic polarization, and AC impedance spectroscopy techniques. The inhibition efficiency was found to increase with increasing concentration of the inhibitors. The effect of immersion time and temperature were also studied. The addition of potassium iodide to the corrosion-inhibition system showed both antagonism and synergism toward inhibition efficiency. Polarization studies revealed the mixed-type inhibiting nature of the carbohydrates. The adsorption of inhibitors on the cast iron surface obeys Langmuir adsorption isotherm model, both in presence and absence of KI. Physical interaction between the inhibitor molecules and the iron surface was suggested by the thermochemical parameters, rather than chemical interaction. PMID:23618271

Rajeswari, Velayutham; Kesavan, Devarayan; Gopiraman, Mayakrishnan; Viswanathamurthi, Periasamy

2013-03-07

33

A semi-fluid gellan gum medium improves nematode toxicity testing.  

PubMed

This study examined an alternative test medium for nematodes that use gellan gum as the gelling agent instead of agar. The semi-fluid consistency of the gel-like component nematode growth gellan gum (CNGG) supports three-dimensional distribution of the nematodes and food bacteria, but still allows free movement of the former. Moreover, flexible preparation of the medium and easy recovery of the test organisms are possible. Here, the effects of the nematicides ivermectin (pharmaceutical) and aldicarb (pesticide) and of the metal cadmium on the growth and reproduction of the free-living nematodes Caenorhabditis elegans and Panagrolaimus cf. thienemanni were studied in CNGG media. Results were compared to those obtained with the standard liquid test media in order to evaluate the applicability of CNGG for nematode toxicity testing. The sensitivity of P. cf. thienemanni to all three substances was found to be higher than that of C. elegans, but both nematodes showed the highest sensitivity to ivermectin exposure. This raises concerns about the risk posed by the pharmaceutical to non-target nematodes. In contrast to ivermectin bioassays carried out in CNGG medium, those conducted in liquid medium resulted in wide-ranging variability between and within replicates. Thus, CNGG seems to be particularly valuable for testing hydrophobic substances with a high sorption affinity as it favors their sorption to food bacteria and minimizes contact with the surfaces of the test vessels. However, the medium was less suitable for deriving toxicity thresholds for cadmium and may likewise not be an appropriate choice for testing other metals. The medium introduced herein was shown to be appropriate for sublethal nematode toxicity testing and likely provides a convenient environment for testing other nematode species. Besides improved testing of hydrophobic substances, CNGG also offers advantages for long-term studies, such as full life-cycle experiments, in which fresh medium is regularly needed. Moreover it may be beneficial for testing other poorly soluble or insoluble substances, such as nanoparticles. PMID:21784524

Brinke, Marvin; Heininger, Peter; Traunspurger, Walter

2011-07-23

34

Cloning and knockout of phytoene desaturase gene in Sphingomonas elodea ATCC 31461 for economic recovery of gellan gum  

Microsoft Academic Search

A gene encoding phytoene desaturase (crtI) in the carotenoid biosynthetic pathway of Sphingomonas elodea ATCC 31461, an industrial gellan gum-producing strain, was cloned and identified. This gene is predicted to encode a 492-amino\\u000a acid protein with significant homology to the phytoene desaturase of other carotenogenic organisms. Knockout of crtI gene blocked yellow carotenoid pigment synthesis and resulted in the accumulation

Liang ZhuXuechang; Xuechang Wu; Ou Li; Yamin Chen; Chaodong Qian; Yi Teng; Xianglin Tao; Haichun Gao

35

Gellan gum blended PEI nanocomposites as gene delivery agents: evidences from in vitro and in vivo studies.  

PubMed

Branched Polyethylenimine, 25 kDa (PEI), was blended with gellan gum, an anionic heteropolysaccharide, for partial neutralization of its excess positive charge to form gellan gum-polyethylenimine (GP) nanocomposites (NCs). Subsequently, we manipulated the amount of gellan gum for obtaining a series of NCs and characterized them for their size, charge and morphology. Among all the NCs, one member, named GP3, showed the best transfection efficiency in tested cell lines in comparison with the rest of the series, PEI, Lipofectamine and other commercial transfection agents and also exhibited minimum cytotoxicity. It was found to transfect primary cells of mouse skin with better efficiency than PEI and Lipofectamine and was able to protect the plasmid DNA from nucleases and serum proteins present in the blood. GP3 exhibited efficient intracellular delivery of plasmid as revealed by confocal studies while its intracellular presence was also confirmed by the knockdown of GFP expression (using GFP specific siRNA) and JNKII by quantifying proteins in cell lysates and by western blotting and hybridization, respectively. In vivo cytotoxicity studies in Drosophila showed lack of induction of stress response in the exposed organisms. Further, exposed organisms did not show any developmental delay or mortality and no morphological defects were observed in the emerged flies. In vivo gene expression studies in Balb/c mice revealed maximum expression of luciferase enzyme in spleen. The study suggests that GP3 may act as an efficient non-viral gene carrier with diverse biomedical applications. PMID:21272636

Goyal, Ritu; Tripathi, S K; Tyagi, Shilpa; Ravi Ram, K; Ansari, K M; Shukla, Y; Kar Chowdhuri, D; Kumar, Pradeep; Gupta, K C

2011-01-25

36

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

2010-11-11

37

Preparation of polymer gel dosimeters based on less toxic monomers and gellan gum.  

PubMed

New polymer gel dosimeters consisting of 2-hydroxyethyl methacrylate (HEMA), triethylene glycol monoethyl ether monomethacrylate (TGMEMA), polyethylene glycol 400 dimethacrylate (9G), tetrakis (hydroxymethyl) phosphonium chloride as an antioxidant, and gellan gum as a gel matrix were prepared. They were optically analyzed by measuring absorbance to evaluate a dose response. The absorbance of the polymer gel dosimeters that were exposed to (60)Co ?-rays increased with increasing dose. The dosimeters comprising HEMA and 9G showed a linear increase in absorbance in the dose range from 0 to 10 Gy. The dose response depended on the 9G concentration. For others comprising HEMA, 9G and TGMEMA, the absorbance of the polymer gel dosimeters drastically increased above a certain dose, and then leveled off up to 10 Gy. The optical variations in these polymer gel dosimeters were also induced by x-irradiation from Cyberknife radiotherapy equipment. Furthermore, the exposed region of the latter polymer gel dosimeter exhibited a thermo-responsive behavior. PMID:24052135

Hiroki, A; Sato, Y; Nagasawa, N; Ohta, A; Seito, H; Yamabayashi, H; Yamamoto, T; Taguchi, M; Tamada, M; Kojima, T

2013-09-20

38

The effects of peptide modified gellan gum and olfactory ensheathing glia cells on neural stem/progenitor cell fate.  

PubMed

The regenerative capacity of injured adult central nervous system (CNS) tissue is very limited. Specifically, traumatic spinal cord injury (SCI) leads to permanent loss of motor and sensory functions below the site of injury, as well as other detrimental complications. A potential regenerative strategy is stem cell transplantation; however, cell survival is typically less than 1%. To improve cell survival, stem cells can be delivered in a biomaterial matrix that provides an environment conducive to survival after transplantation. One major challenge in this approach is to define the biomaterial and cell strategies in vitro. To this end, we investigated both peptide-modification of gellan gum and olfactory ensheathing glia (OEG) on neural stem/progenitor cell (NSPC) fate. To enhance cell adhesion, the gellan gum (GG) was modified using Diels-Alder click chemistry with a fibronectin-derived synthetic peptide (GRGDS). Amino acid analysis demonstrated that approximately 300 nmol of GRGDS was immobilized to each mg of GG. The GG-GRGDS had a profound effect on NSPC morphology and proliferation, distinct from that of NSPCs in GG alone, demonstrating the importance of GRGDS for cell-GG interaction. To further enhance NSPC survival and outgrowth, they were cultured with OEG. Here NSPCs interacted extensively with OEG, demonstrating significantly greater survival and proliferation relative to monocultures of NSPCs. These results suggest that this co-culture strategy of NSPCs with OEG may have therapeutic benefit for SCI repair. PMID:22698724

Silva, Nuno A; Cooke, Michael J; Tam, Roger Y; Sousa, Nuno; Salgado, Antnio J; Reis, Rui L; Shoichet, Molly S

2012-06-12

39

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

40

A comparison of fibrin, agarose and gellan gum hydrogels as carriers of stem cells and growth factor delivery microspheres for cartilage regeneration.  

PubMed

The limited intrinsic repair capacity of articular cartilage has led to the investigation of different treatment options to promote its regeneration. The delivery of hydrogels containing stem or progenitor cells and growth factor releasing microspheres represents an attractive approach to cartilage repair. In this study, the influence of the encapsulating hydrogel on the ability of progenitor cells coupled with TGF-?3 releasing microspheres to form cartilaginous tissue was investigated. Fibrin, agarose and gellan gum hydrogels containing TGF-?3 loaded gelatin microspheres and progenitor cells derived from the infrapatellar fat-pad of the knee were cultured for 21days in a chemically defined media. In the presence of TGF-?3 releasing microspheres, gellan gum hydrogels were observed to facilitate greater cell proliferation than fibrin or agarose hydrogels. Histological and biochemical analysis of the hydrogels indicated that fibrin was the least chondro-inductive of the three hydrogels, while agarose and gellan gum appeared to support more robust cartilage formation as demonstrated by greater sGAG accumulation within these constructs. Gellan gum hydrogels also stained more intensely for collagen type II and collagen type I, suggesting that although total collagen synthesis was higher in these constructs, that the phenotype may be more fibrocartilaginous in nature than normal hyaline cartilage. This study demonstrates how the encapsulating hydrogel can have a significant impact on the ability of stem cells to form cartilage when incorporated into a growth factor delivery system. PMID:23532058

Ahearne, Mark; Kelly, Daniel J

2013-03-26

41

Preparation and characterization of a new gellan gum and sulphated hyaluronic acid hydrogel designed for epidural scar prevention.  

PubMed

Postsurgical adhesions are a common problem in clinical practice, causing nerve compression, pain and discomfort. A new hydrogel based on gellan gum and sulphated hyaluronic acid was synthesized, with the aim to create an effective barrier for epidural scar formation. Physico-chemical properties of the gel were analyzed, and preliminary biocompatibility data (i.e. cytotoxicity) have been collected in view of its potential clinical use. The characterization of the new material demonstrated that the hydrogel, due to its high-viscosity, could effectively act as a barrier with a long in situ residence time. In addition, the hydrogel can be easily extruded from a syringe and its structure exhibits excellent stabilizing properties. Furthermore, biological assays showed that this gel is suitable for further preclinical development. PMID:21221734

Cencetti, Claudia; Bellini, Davide; Longinotti, Cristina; Martinelli, Andrea; Matricardi, Pietro

2011-01-08

42

Development of gellan gum-based microparticles/hydrogel matrices for application in the intervertebral disc regeneration.  

PubMed

Low back pain is one of the most reported medical conditions associated to intervertebral disc (IVD) degeneration. Nucleus pulposus (NP) is often regarded as the structure where IVD degeneration begins. Gellan gum (GG)-based hydrogels for acellular and cellular tissue engineering strategies have been developed for finding applications as NP substitutes. The innovative strategy is based on the reinforcement of the hydrogel matrix with biocompatible and biodegradable GG microparticles (MPs), which are expected to improve the mechanical properties, while allowing to tailor its degradation rate. In this study, several GG MP/hydrogel disc formulations were prepared by means of mixing high acyl GG (0.75% (w/v)) and low acyl GG (2% (w/v)) GG aqueous solutions at different ratios, namely, 75%:25% (v/v), 50%:50% (v/v), and 25%:75% (v/v), respectively. The GG MP size was measured using a stereo microscope, and their dispersion within the hydrogel matrix was evaluated by means of staining the MPs with Toluidine Blue-O. The developed GG MPs/hydrogel discs were physicochemically characterized by Fourier-transform infrared spectroscopy and (1)H-nuclear magnetic resonance spectroscopy. The swelling behavior and degradation rate were assessed by immersion in a phosphate buffer saline for 14 days. The morphology and mechanical behavior were investigated by scanning electron microscopy and dynamic mechanical analysis, respectively. The mechanical properties of the hydrogel disc were improved by mixing the gels with the MPs. In addition, the possible cytotoxicity of the leachables released by MPs/hydrogel discs was screened in vitro, using a mouse lung fibroblast cell line (L929 cells). To investigate the encapsulation efficacy of L929 cells into the GG MPs/hydrogel discs, cells were stained with DAPI blue/Texas Red-Phalloidin and observed by confocal microscopy, after 24, 48, and 72 h of culturing. A cell viability assay was also performed using Calcein AM staining. The cell culture studies demonstrated that MPs/hydrogel discs are noncytotoxic over L929 cells. It was also demonstrated that L929 cells can be successfully encapsulated into the GG MPs of different formulations, remaining viable after 72 h of culturing. This study showed that GG hydrogel matrices reinforced with cell-loaded MPs could be a candidate strategy for NP regeneration. PMID:21574937

Pereira, Diana Ribeiro; Silva-Correia, Joana; Caridade, Sofia Glria; Oliveira, Joao T; Sousa, Rui A; Salgado, Antonio J; Oliveira, Joaquim M; Mano, Joo F; Sousa, Nuno; Reis, Rui L

2011-07-07

43

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

2012-10-01

44

Improvement in Production and Quality of Gellan Gum by Sphingomonas paucimobilis Under High Dissolved Oxygen Tension Levels  

Microsoft Academic Search

The effect of agitation rate and dissolved oxygen tension (DOT) on growth and gellan production by Sphingomonas paucimobilis was studied. Higher cell growth of 5.4gl?1 was?obtained at 700rpm but maximum gellan (15gl?1) was produced at 500rpm. DOT levels above 20% had no effect on cell growth but gellan yield was increased to 23gl?1 with increase in DOT level to 100%.

R. M. Banik; A. Santhiagu

2006-01-01

45

Identification of the pgmG Gene, Encoding a Bifunctional Protein with Phosphoglucomutase and Phosphomannomutase Activities, in the Gellan Gum-Producing Strain Sphingomonas paucimobilis ATCC 31461  

PubMed Central

The pgmG gene of Sphingomonas paucimobilis ATCC 31461, the industrial gellan gum-producing strain, was cloned and sequenced. It encodes a 50,059-Da polypeptide that has phosphoglucomutase (PGM) and phosphomannomutase (PMM) activities and is 37 to 59% identical to other bifunctional proteins with PGM and PMM activities from gram-negative species, including Pseudomonas aeruginosa AlgC. Purified PgmG protein showed a marked preference for glucose-1-phosphate (G1P); the catalytic efficiency was about 50-fold higher for G1P than it was for mannose-1-phosphate (M1P). The estimated apparent Km values for G1P and M1P were high, 0.33 and 1.27 mM, respectively. The pgmG gene allowed the recovery of alginate biosynthetic ability in a P. aeruginosa mutant with a defective algC gene. This result indicates that PgmG protein can convert mannose-6-phosphate into M1P in the initial steps of alginate biosynthesis and, together with other results, suggests that PgmG may convert glucose-6-phosphate into G1P in the gellan pathway.

Videira, Paula A.; Cortes, Luisa L.; Fialho, Arsenio M.; Sa-Correia, Isabel

2000-01-01

46

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 6.9MPa, 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

2012-01-20

47

Biochemical characterization of the beta-1,4-glucuronosyltransferase GelK in the gellan gum-producing strain Sphingomonas paucimobilis A.T.C.C. 31461.  

PubMed Central

Biosynthesis of bacterial polysaccharide-repeat units proceeds by sequential transfer of sugars, from the appropriate sugar donor to an activated lipid carrier, by committed glycosyltransferases (GTs). Few studies on the mechanism of action for this type of GT are available. Sphingomonas paucimobilis A.T.C.C. 31461 produces the industrially important polysaccharide gellan gum. We have cloned the gelK gene from S. paucimobilis A.T.C.C. 31461. GelK belongs to family 1 of the GT classification [Campbell, Davies, Bulone, Henrissat (1997) Biochem. J. 326, 929-939]. Sequence similarity studies suggest that GelK consists of two protein modules corresponding to the -NH(2) and -CO(2)H halves, the latter possibly harbouring the GT activity. The gelK gene and the open reading frames coding for the -NH(2) (GelK(NH2)) and -CO(2)H (GelK(COOH)) halves were overexpressed in Escherichia coli. GelK and GelK(NH2) were present in both the soluble and membrane fractions of E. coli, whereas GelK(COOH) was only present in the soluble fraction. GelK catalysed the transfer of [(14)C]glucuronic acid from UDP-[(14)C]glucuronic acid into a glycolipid extracted from S. paucimobilis or E. coli, even in the presence of EDTA, and the radioactive sugar was released from the glycolipid by beta-1,4-glucuronidase. GelK was not able to use synthetic glucosyl derivatives as acceptors, indicating that the PP(i)-lipid moiety is needed for enzymic activity. Recombinant GelK(NH2) and GelK(COOH) did not show detectable activity. Based on the biochemical characteristics of GelK and on sequence similarities with N-acetylglucosaminyltransferase, we propose that GT families 1 and 28 form a superfamily.

Videira, P; Fialho, A; Geremia, R A; Breton, C; Sa-Correia, I

2001-01-01

48

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

PubMed Central

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.

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

2012-01-01

49

Gum Arabic surface-modified magnetic nanoparticles for cancer therapy  

Microsoft Academic Search

The objective of this study is to investigate the influence of Gum Arabic-modified magnetic nanoparticles on cellular uptake. The ultimate goal is to develop a technique to promote the selective uptake of magnetic nanoparticles by cancer cells for cancer treatment. A novel use of magnetic fields and magnetic particles is to deliver therapeutic drugs at the desired time in the

U. Effiong; D. Williams; W. Otto; W. Anderson

2004-01-01

50

Electrotransformacao de 'Pseudomonas elodea' na Clonagem dos Genes Envolvidos na Sintese do Gelano (Electrotransformation of 'Pseudomonas elodea' in the Cloning of Genes Involved in Gellan Synthesis).  

National Technical Information Service (NTIS)

Gellan gum is a exopolysaccharide produced with a high yield by Pseudomonas elodea ATCC31461. The cloning and identification of the genes of the gellan biosynthetic path can allow the development of new polysaccharides with different chemical composition ...

G. A. A. Monteiro

1991-01-01

51

Fast removal of copper ions by gum arabic modified magnetic nano-adsorbent  

Microsoft Academic Search

A novel magnetic nano-adsorbent was developed by treating Fe3O4 nanoparticles with gum arabic to remove copper ions from aqueous solutions. Gum arabic was attached to Fe3O4 via the interaction between the carboxylic groups of gum arabic and the surface hydroxyl groups of Fe3O4. The surface modification did not result in the phase change of Fe3O4, while led to the formation

Shashwat S. Banerjee; Dong-Hwang Chen

2007-01-01

52

Gum Arabic-Coated Magnetic Nanoparticles for Potential Application in Simultaneous Magnetic Targeting and Tumor Imaging  

Microsoft Academic Search

Magnetic iron oxide nanoparticles (MNP) coated with gum arabic (GA), a biocompatible phytochemical glycoprotein widely used\\u000a in the food industry, were successfully synthesized and characterized. GA-coated MNP (GA-MNP) displayed a narrow hydrodynamic\\u000a particle size distribution averaging about 100nm; a GA content of 15.6% by dry weight; a saturation magnetization of 93.1emu\\/g\\u000a Fe; and a superparamagnetic behavior essential for most magnetic-mediated

Lei Zhang; Faquan Yu; Adam J. Cole; Beata Chertok; Allan E. David; Jingkang Wang; Victor C. Yang

2009-01-01

53

21 CFR 172.665 - Gellan gum.  

Code of Federal Regulations, 2013 CFR

...Pseudomonas elodea by a pure culture fermentation process and purified by recovery with isopropyl alcohol. It is composed of tetrasaccharide...will form. (2) Residual isopropyl alcohol (IPA) not to exceed 0.075...

2013-04-01

54

Gellan: Influence of the fermentor hydrodynamics on its production, its physico-chemical characteristics and its possibilities of appliance in drilling fluids.  

National Technical Information Service (NTIS)

Gellan gum is a new bacterial polysaccharide exhibiting interesting properties. This study deals with the effect of fermentor hydrodynamics on production, physico-chemical characteristics and potentialities of this biopolymer in non polluting well drillin...

E. Dreveton

1994-01-01

55

Characterization of magnetic guar gum-grafted carbon nanotubes and the adsorption of the dyes  

Microsoft Academic Search

The hydrophobicity of carbon nanotubes (CNTs) limits their extensive application. The hydrophilicity and biocompatibility of CNTs can be improved by modifying them with biopolymers. As a natural biopolymer, guar gum (GG) was covalently grafted on the surfaces of multiwall carbon nanotube (MWCNT) to obtain GGMWCNT composite. Then iron oxide nanoparticles were synthesized on the GGMWCNT to prepare the magnetic GGMWCNTFe3O4.

Li Yan; Peter R. Chang; Pengwu Zheng; Xiaofei Ma

56

Freezethaw stabilization of sweet potato starch gel by polysaccharide gums  

Microsoft Academic Search

Nine polysaccharide gums (sodium alginate, carboxymethyl cellulose, curdlan, gellan, guar gum, gum arabic, ?-carrageenan, locust bean, and xanthan) were compared for their stabilizing effects in sweet potato starch gel against repeated freezethawing (FT) treatments. The gums were added in starch gel at 0.3 or 0.6% (w\\/w, based on total gel weight), and total solid content in the gel was adjusted

M. H. Lee; M. H. Baek; D. S. Cha; H. J. Park; S. T. Lim

2002-01-01

57

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

58

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.

2012-01-01

59

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

60

Gum Disease  

MedlinePLUS

... which is both embarrassing and serious!). What Is Gum Disease? Gum disease is also known as periodontal (pronounced: per- ... tissues and bone that support the teeth. Untreated gum disease can become very serious, causing teeth to ...

61

Gum biopsy  

MedlinePLUS

Biopsy - gingiva (gums) ... the mouth in the area of the abnormal gum tissue. In some cases, a numbing injection may be used. A small piece of the gum tissue that appears abnormal is removed and checked ...

62

Structures and Properties of Gellan Polymers Produced by Sphingomonas paucimobilis ATCC 31461 from Lactose Compared with Those Produced from Glucose and from Cheese Whey  

Microsoft Academic Search

The dairy industry produces large quantities of whey as a by-product of cheese production and is increas- ingly looking for new ways to utilize this waste product. Gellan gum is reliably produced by Sphingomonas paucimobilis in growth media containing lactose, a significant component of cheese whey, as a carbon source. We studied and compared polysaccharide biosynthesis by S. paucimobilis ATCC

ARSENIO M. FIALHO; LIGIA O. MARTINS; MARIE-LUCIE DONVAL; JORGE H. LEITAO; MICHAEL J. RIDOUT; ANDREW J. JAY; VICTOR J. MORRIS; ISABEL SA -CORREIA

1999-01-01

63

Nicotine Gum  

MedlinePLUS

... chewing gum should be used together with a smoking cessation program, which may include support groups, counseling, or ... gum is in a class of medications called smoking cessation aids. It works by providing nicotine to your ...

64

Chitosan-gellan electrostatic complexes: influence of preparation conditions and surfactant presence.  

PubMed

Nanoparticles were obtained by electrostatic complexation between chitosan and gellan gum at different polysaccharide ratios. The effect of the chitosan:gellan ratio on the particle charge and particle size distribution was determined by dynamic light scattering measurements. The particle stability was studied during storage in an aqueous medium at 25C for 100 h. The effect of the preparation procedure (mixing steps) on the characteristics of the complexes was also determined. In addition, the influence of a nonionic surfactant (polysorbate-20) on the chitosan:gellan electrostatic complexes (PECs) was evaluated. The charge of the PECs depended on the polysaccharide ratio. During storage, structural reorganization of the complexes was observed. The mixture protocol was a determinant factor for PEC size. Multilayered particles formed by a 2-step mixing of polysaccharide solutions showed a considerable increase in size as compared to the complexes formed by a 1-step mixing. The PEC size, count rate and zeta potential were not affected by the presence of polysorbate-20. PMID:23544592

Picone, Carolina Siqueira Franco; Cunha, Rosiane Lopes

2013-02-07

65

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

66

Large deformation analysis of gellan gels  

NASA Astrophysics Data System (ADS)

Gellan gel, a typical polysaccharide gel, is ruptured with different deformation behaviors from gelatin gel or rubber. It exhibits both strain hardening and softening; hardening is observed for moderate strain and softening occurs for larger strain. From the analyses of stress-strain curves of gellan gels, we propose forms of strain energy function. The fit with the proposed equation was excellent, while the existing models fail because they consider only one of hardening or softening effect. Furthermore, these equations are shown to be capable of extracting the hardening and softening effects separately from the observed stress-strain curves. By using these fitting equations, the concentration dependences of hardening and softening are investigated. It is shown that the degrees of hardening and softening both increase with increasing gellan concentration.

Kawai, Shinnosuke; Nitta, Yoko; Nishinari, Katsuyoshi

2007-08-01

67

Texture profile and turbidity of gellan\\/gelatin mixed gels  

Microsoft Academic Search

The effect of gellan (1.60.2%) to gelatin (01.4%) ratio and calcium ion concentration (030 mM) on the textural properties and turbidity of gellan\\/gelatin mixed gels was examined using instrumental Texture Profile Analysis (TPA) and spectrophotometry. Hardness of the mixed gels decreased as the proportion of gellan decreased. Hardness increased with increasing calcium ions until calcium concentration reached a critical level,

M. H. Lau; J. Tang; A. T. Paulson

2000-01-01

68

Injectable in situ physically and chemically crosslinkable gellan hydrogel.  

PubMed

An injectable, in situ physically and chemically crosslinkable gellan hydrogel is synthesized via gellan thiolation. The thiolation does not alter the gellan's unique 3-D conformation, but leads to a lower phase transition temperature under physiological conditions and stable chemical crosslinking. The synthesis and hydrogels are characterized by (1)H NMR, FT-IR, CD, or rheology measurements. The injectability and the tissue culture cell viability is also tested. The thiolated gellan hydrogel exhibits merits, such as ease for injection, quick gelation, lower gelling temperature, stable structure, and nontoxicity, which make it promising in biomedicine and bioengineering as an injectable hydrogel. PMID:22707249

Du, Hongwei; Hamilton, Paul; Reilly, Mattew; Ravi, Nathan

2012-06-18

69

Gum Disease  

MedlinePLUS

... damage to the tissue and bone supporting the teeth. In the worst cases, you can lose teeth. In gingivitis, the gums become red and swollen. ... flossing and regular cleanings by a dentist or dental hygienist. Untreated gingivitis can lead to periodontitis. If ...

70

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

71

Brain Functional Network for Chewing of Gum  

Microsoft Academic Search

\\u000a Recent studies showed that gum-chewing induced significant increases in cerebral blood flow and blood-oxygenation level in\\u000a the widespread brain regions. However, little is known about the underlying mechanism of chewing-induced regional interconnection\\u000a and interaction within the brain. In this study, we investigated the human brain functional network during chewing of gum\\u000a by using functional magnetic resonance imaging and complex network

Ming Ke; Hui Shen; Zongtan Zhou; Xiaolin Zhou; Dewen Hu; Xuhui Chen

72

What Happens to Swallowed Gum?  

MedlinePLUS

... The Pink Locker Society What Happens to Swallowed Gum? KidsHealth > Kids > Q&A > Icky Q & A > What ... have a bowel movement (poop). When Is Swallowed Gum a Problem? Swallowing a large mass of gum, ...

73

Gum Disease and Men  

MedlinePLUS

... Gum Disease Regenerative Procedures Dental Crown Lengthening Procedure Dental Implants Single Tooth Implants Multiple Tooth Implants Full Mouth Dental Implants Sinus Augmentation Ridge Modification Periodontal Pocket Reduction Procedures ...

74

Gum Disease and Women  

MedlinePLUS

... Gum Disease Regenerative Procedures Dental Crown Lengthening Procedure Dental Implants Single Tooth Implants Multiple Tooth Implants Full Mouth Dental Implants Sinus Augmentation Ridge Modification Periodontal Pocket Reduction Procedures ...

75

Effect of polymer ratio and calcium concentration on gelation properties of gellan\\/gelatin mixed gels  

Microsoft Academic Search

Gelation properties of gellan\\/gelatin mixed solutions were studied using dynamic viscoelastic testing at eight different ratios of gellan (1.60.2% w\\/v) to gelatin (01.4% w\\/v) and seven different calcium levels (030 mM). The gelation temperature and gelation rate of the mixed gels were significantly affected by the ratio of gellan to gelatin as well as concentration of calcium. Addition of calcium

M. H. Lau; J. Tang; A. T. Paulson

2001-01-01

76

Extractive fermentation for enhanced gellan-hydrolysing enzyme production by Bacillus thuringiensis H14  

Microsoft Academic Search

A new extractive fermentation process using PEG and potassium phosphate aqueous two-phase system (ATPS) was developed for enhanced production of gellan-hydrolysing enzyme by Bacillus thuringiensis H14. Five different Bacillus sp. were tested for their ability to synthesize gellan-hydrolysing enzyme. Bacillus thuringiensis H14 was found to be the best organism for gellan-hydrolysing enzyme production. The enzyme showed maximum activity at pH

R. M. Banik; A. Santhiagu

2002-01-01

77

Adsorption of gum Arabic on bioceramic nanoparticles  

Microsoft Academic Search

Surface modification agents can be used to tailor the surface chemistry and biological activity of bioceramic nanoparticles in very intriguing ways. However, the specific modes of interactions between macromolecules and nanoparticles can be difficult to characterize. The aim of this study was to investigate the adsorption of gum Arabic on hydroxyapatite (HAp) and magnetic nanoparticles (MNP) using the bicinchoninic acid

A. C. A. Roque; O WILSONJR

2008-01-01

78

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 S-Correia

2008-01-01

79

Physicochemical characteristics of a thermostable gellan lyase from Geobacillus stearothermophilus 98.  

PubMed

A purified thermostable gellan lyase, produced by a thermophilic bacterium, Geobacillus stearothermophilus 98, was characterized in relation to its physicochemical properties. The gellan lyase was established to have a molecular weight of 216 kDa, defined by capillary gel electrophoresis. Amino acid analysis revealed high quantities of Lys, His, Ala, Val, Ile, Glx, and Pro residues. The circular dichroism revealed 45% beta-structure and practically lack of a-spiral domains. Kinetic studies showed high affinity of the enzyme to gellan as a substrate (Km = 0.21 microM). The thermal denaturation investigated by cicular dichroism showed a highly cooperative transition with a midpoint (Tm) at about 75 degrees C. A single product was identified after enzyme action on gellan. Large exothermic aggregation near Tm was observed by differential scanning calorimetry. Two types of gellan lyase crystals were reproducibly isolated. PMID:20469643

Derekova, Anna; Atanassova, Miroslava; Christova, Petya; Tchorbanov, Bojidar; Shosheva, Alexandra; Mandeva, Rossitsa; Rodrguez-Alonso, Patricia; Garabal, Jose I; Kambourova, Margarita

80

The effect of three gums on the retrogradation of indica rice starch.  

PubMed

Retrograded starch (RS(3)) was produced from indica rice starch with three kinds of gums (konjac glucomannan, KGM; carrageenan, CA, USA; and gellan, GA, USA) by autoclaving, respectively, and the effect of the gums on the retrogradation behavior of starch was estimated. The influences of polysaccharide concentration, sodium chloride concentration, autoclaving time, refrigerated time, and pH value on RS(3) formation were discussed. Except for sodium chloride's persistent restraint on RS(3), the others all forced RS(3) yields higher at first, but lowered it after the peak value. The influencing sequence of these impact factors was: sodium chloride concentration > polysaccharide concentration > autoclaving time > refrigerated time > pH value. The results also proved that in the three gums, KGM plays the most significant role in RS(3) changing. It was concluded that the incorporation of each of these three gums into starch, especially KGM, results in an increase or decrease of RS(3) under different conditions. This phenomenon could be taken into consideration when developing starchy food with appropriate amount of RS(3). PMID:22822444

Song, Rukun; Huang, Min; Li, Bin; Zhou, Bin

2012-05-29

81

The Effect of Three Gums on the Retrogradation of Indica Rice Starch  

PubMed Central

Retrograded starch (RS3) was produced from indica rice starch with three kinds of gums (konjac glucomannan, KGM; carrageenan, CA, USA; and gellan, GA, USA) by autoclaving, respectively, and the effect of the gums on the retrogradation behavior of starch was estimated. The influences of polysaccharide concentration, sodium chloride concentration, autoclaving time, refrigerated time, and pH value on RS3 formation were discussed. Except for sodium chlorides persistent restraint on RS3, the others all forced RS3 yields higher at first, but lowered it after the peak value. The influencing sequence of these impact factors was: sodium chloride concentration > polysaccharide concentration > autoclaving time > refrigerated time > pH value. The results also proved that in the three gums, KGM plays the most significant role in RS3 changing. It was concluded that the incorporation of each of these three gums into starch, especially KGM, results in an increase or decrease of RS3 under different conditions. This phenomenon could be taken into consideration when developing starchy food with appropriate amount of RS3.

Song, Rukun; Huang, Min; Li, Bin; Zhou, Bin

2012-01-01

82

Assessment of cassia gum.  

PubMed

Cassia gum is approved for use in Europe by the Commission Directive (EEC No. E 499) and is listed in the Annex of the Council Directive (70/524/EEC) as a stabilizer (thickening and gelling agent) in the manufacture of canned pet foods (for cats and dogs). It is also approved for use in Japan and is listed as a food additive in The Ministry of Health and Welfare Announcement No. 160 (10 August 1995). A panel of experts in the areas of toxicology, pharmacology and food science was assembled to review the safety of cassia gum for use as a thickening agent in human and pet foods in the United States. The available data on cassia gum and structurally related gums demonstrate a lack of toxic effects in animals. This review is the basis for the consideration of cassia gum as generally recognized as safe (GRAS) under conditions of its intended use as a thickening agent in human and pet foods. PMID:9225022

Hallagan, J B; La Du, B N; Pariza, M W; Putnam, J M; Borzelleca, J F

1997-06-01

83

Chewing gum affects smoking topography.  

PubMed

In a previous study, Wrigley's chewing gum was shown to reduce cravings to smoke and nicotine withdrawal when smokers were not allowed access to cigarettes. The present study expanded these findings by examining smoking behavior of 20 dependent cigarette smokers who were allowed free access to cigarettes throughout the study session but were encouraged and rewarded not to smoke. Each experimental session consisted of the participant watching a movie, then waiting an additional 30 min. Half of the participants were assigned to a gum condition in which they were asked to chew at least one piece of gum and had free access to chewing gum throughout the experimental session; half were assigned to a no-gum control. Results from this study indicate that when gum was present, participants took significantly fewer puffs and abstained for a longer period of time until their first cigarette. These results suggest that chewing gum may facilitate quit attempts. PMID:10609978

Cohen, L M; Britt, D M; Collins, F L; Stott, H D; Carter, L C

1999-11-01

84

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

85

Plastic Surgery Procedures (for Gums)  

MedlinePLUS

... Gum Disease Regenerative Procedures Dental Crown Lengthening Procedure Dental Implants Single Tooth Implants Multiple Tooth Implants Full Mouth Dental Implants Sinus Augmentation Ridge Modification Periodontal Pocket Reduction Procedures ...

86

Dispelling Myths about Gum Disease  

MedlinePLUS

... Gum Disease Regenerative Procedures Dental Crown Lengthening Procedure Dental Implants Single Tooth Implants Multiple Tooth Implants Full Mouth Dental Implants Sinus Augmentation Ridge Modification Periodontal Pocket Reduction Procedures ...

87

Gum Disease Risk Assessment Test  

MedlinePLUS

... Gum Disease Regenerative Procedures Dental Crown Lengthening Procedure Dental Implants Single Tooth Implants Multiple Tooth Implants Full Mouth Dental Implants Sinus Augmentation Ridge Modification Periodontal Pocket Reduction Procedures ...

88

Conservation of Mass Gum Lab  

NSDL National Science Digital Library

Students develop and conduct an experiment using the law of conservation of mass to determine whether or not gum should be considered food. Students will compare the mass swallowed for sugar and sugar-free gum. This could be used to discuss solubility.

89

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

90

Enzymatically-treated guar gums  

SciTech Connect

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.

Carter, W.H.; Srivastava, V.K.

1987-07-28

91

FT-Raman spectroscopy of gums of technological significance  

Microsoft Academic Search

The FT-Raman spectra of four technically important gums, namely, locust bean gum, karaya gum (five varieties), gum tragacanth (nine varieties) and gum ghatti (four varieties), are reported. Bands characteristic of each gum which can be used for their identification are identified and assigned to molecular species where possible. Because the gums contain similar chemical components, an integral part of the

H. G. M Edwards; M. J Falk; M. G Sibley; J. Alvarezbenedi; F. Rull

1998-01-01

92

Evaluation of the Health Aspects of Oat Gum, Okra Gum, Quince Seed Gum, and Psyllium Seed Husk Gum as Food Ingredients.  

National Technical Information Service (NTIS)

This report, by a group of qualified scientists designated the Select Committee of GRAS Substances (SCOGS), provides an independent evaluation of the safety of the health aspects of oat gum, okra gum, quince seed gum, and psyllium seed husk gum as food in...

1982-01-01

93

Structural studies on matrices of deacylated gellan with polydextrose.  

PubMed

The effect of varying concentrations of co-solute (polydextrose) on thermomechanical and physicochemical properties of deacylated gellan matrices is presented. Modulated differential scanning calorimetry, micro differential scanning calorimetry, small deformation dynamic oscillation in shear, Fourier transform infrared spectroscopy, wide angle X-ray diffraction and environmental scanning electron microscopy have been used to investigate the structural transformations in aqueous, low-solid and condensed systems. There was a rise in values of storage modulus as the level of co-solute was increased, followed by a significant decline at intermediate concentrations, with high modulus values being regained as more of the co-solute was incorporated. These results confirm the hypothesis of a structural transformation from a highly enthalpic aggregated assembly in the aqueous/low-solid environment to a lightly cross linked polysaccharide network in the high solids regime. Time-temperature superposition (TTS) phenomena observed for amorphous synthetic polymers have been utilised to generate master curves of viscoelasticity, which afforded rationalisation of results on the basis of the free volume theory. PMID:23199988

Chaudhary, Vinita; Small, Darryl M; Kasapis, Stefan

2012-10-17

94

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

95

Borate-gum gel breakers  

Microsoft Academic Search

This is a delayed action gel breaker for borate-gum gels. Water-base fracturing fluid is widely used in hydraulic fracturing operations. Borate ions and certain natural gums having cis di-diol groups or adjcent cis hydroxyl units form a gel in water to produce a satisfactory fracturing fluid. The gel must retain its high viscosity and particle suspending qualities from 1 to

R. E. Wyant; T. K. Perkins; T. F. Moore

1964-01-01

96

The comparison of rheological properties of aqueous welan gum and xanthan gum solutions.  

PubMed

Rheological properties of welan gum and xanthan gum solutions have been characterized systematically at various concentrations, temperatures and salinities. It is found that the viscoelasticity of welan gum is higher than that of xanthan gum at the same condition though the molecular weight of welan gum is lower. In view of this, welan gum will make a good performance in enhanced oil recovery, especially in high temperature and high salinity reservoirs. Network structure can be formed in solutions of welan gum and xanthan gum for the dynamic modulus has exponential relationship with the concentration. Moreover, the molecular aggregates of welan gum adopt a different arrangement with that of xanthan gum, adjacent double helices of welan gum arrange in parallel as the zipper model. The structure formed by zipper model is still stable in high temperature and high salinity. PMID:23218329

Xu, Long; Xu, Guiying; Liu, Teng; Chen, Yijian; Gong, Houjian

2012-10-13

97

Novel plasma-separation dilayer gellangellan-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

98

'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

99

21 CFR 201.319 - Water-soluble gums, hydrophilic gums, and hydrophilic mucilloids (including, but not limited to...  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Water-soluble gums, hydrophilic gums, and hydrophilic mucilloids (including, but not...B-1,4 linked) polymannose acetate), guar gum, karaya gum, kelp, methylcellulose, plantago...

2010-04-01

100

21 CFR 201.319 - Water-soluble gums, hydrophilic gums, and hydrophilic mucilloids (including, but not limited to...  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Water-soluble gums, hydrophilic gums, and hydrophilic mucilloids (including, but not...B-1,4 linked) polymannose acetate), guar gum, karaya gum, kelp, methylcellulose, plantago...

2009-04-01

101

GUM: A Portable Parallel Implementation of Haskell  

Microsoft Academic Search

GUM is a portable, parallel implementation of the Haskell functional language. Despite sustained research interest in parallel functional programming, GUM is one of the first such systems to be made publicly available.GUM is message-based, and portability is facilitated by using the PVM communications harness that is available on many multi-processors. As a result, GUM is available for both shared-memory (Sun

Philip W. Trinder; Kevin Hammond; James S. Mattson Jr.; A. S. Partridge; Simon L. Peyton Jones

1996-01-01

102

Production of recombinant plant gum with tobacco cell culture in bioreactor and gum characterization  

Microsoft Academic Search

Many plant gums, such as gum arabic, contain hydroxyproline-rich glycoproteins (HRGPs), which are also abundant components of the plant cell extracellular matrix. Here we expressed in transgenic BY2 Nicotiana tabacum (tobacco) cells, a synthetic gene encoding a novel HRGP-based gum, designated gum arabic-8 or (GA)8. (GA)8 encoded eight repeats of the consensus polypeptide sequence of gum arabic glycoprotein (GAGP): Gly-Pro-

Jianfeng Xu; Elena Shpak; Tingyue Gu; Murray Moo-Young; Marcia Kieliszewski

2005-01-01

103

21 CFR 172.695 - Xanthan gum.  

Code of Federal Regulations, 2010 CFR

... 3 2010-01-01 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 Xanthan...

2010-01-01

104

21 CFR 172.695 - Xanthan gum.  

Code of Federal Regulations, 2010 CFR

... 3 2009-04-01 2009-04-01 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 Xanthan...

2009-04-01

105

21 CFR 184.1339 - Guar gum.  

Code of Federal Regulations, 2010 CFR

...Drugs 3 2010-01-01 2009-04-01 true Guar gum. 184.1339 Section 184.1339 Food and...Specific Substances Affirmed as GRAS § 184.1339 Guar gum. (a) Guar gum is the natural substance obtained from the...

2010-01-01

106

21 CFR 184.1339 - Guar gum.  

Code of Federal Regulations, 2010 CFR

...Drugs 3 2009-04-01 2009-04-01 false Guar gum. 184.1339 Section 184.1339 Food and...Specific Substances Affirmed as GRAS § 184.1339 Guar gum. (a) Guar gum is the natural substance obtained from the...

2009-04-01

107

The effect of added sucrose and corn syrup on the physical properties of gellangelatin mixed gels  

Microsoft Academic Search

Gellangelatin blends in the presence of high levels of co-solute (sucrose plus corn syrup) are thermally stable systems with increased gel strength. Dynamic oscillatory analysis (frequency, timetemperature and strain sweeps) demonstrated that the two polymeric components form gelled phases with diverse viscoelastic properties. Gellan continuous mixtures could be prepared easily since the polysaccharide is capable of forming a supporting matrix

Maria Papageorgiou; Stefan Kasapis

1995-01-01

108

TECHNICAL NOTE: The strengthening effect of guar gum on the yield stress of magnetorheological fluid  

NASA Astrophysics Data System (ADS)

In this paper we present a novel approach for producing obvious strengthening of the magnetorheological (MR) effect of MR fluids. Carbonyl iron powders coated with guar gum were used as magnetic particles in the MR fluid. Experimental results showed that inducing a guar gum coating not only greatly improved the sedimentation stability but also strengthened the yield stress of the MR fluid. An intermolecular force based model was proposed for explaining the strengthening effect.

Wu, Wei Ping; Zhao, Bin Yuan; Wu, Qing; Chen, LeSheng; Hu, Ke Ao

2006-08-01

109

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.

2004-01-01

110

How Much Sugar Is in Bubble Gum?  

NSDL National Science Digital Library

Most 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 flavor, 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-Ph.d. Program

111

Analytical testing and characterization of three polysiloxane gums. [RG97, SE54, Y3976  

SciTech Connect

Because of the termination of both silicone gums and cellular silicone products by Union Carbide Corporation, it has been necessary to evaluate commercial alternatives as well as potential developmental polymer replacements for W97. For this reason, LLNL, Bendix Corporation, and the Pantex plant have undertaken the development of characterization methodology for silicone gums as well as the concomitant chemical and physical analyses of the polysiloxanes RG97, SE54 and Y3976. The most viable test battery to arise from this study is the determination of anti M/sub w/, anti M/sub n/, and MWD by GPC, vinyl and phenyl contents of the gums by magnetic resonance or chromatographic techniques, and volatile content of the gums by thermogravimetric analysis. A comparison of the siloxane gums indicates that the random SE54 is a high phenyl content, high molecular weight, low volatile resin of high quality. RG97 is in contrast a relatively low molecular weight, high volatile content gum that is inferior to SE54. The developmental material Y3976, which is synthesized by a different procedure, is close in properties to the SE54 gum but is somewhat lower in phenyl content. 3 figures, 10 tables.

Kolb, J.R.; Cady, W.E.; Jessop, E.S.; Hoffman, D.M.

1980-04-28

112

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

113

Brief report: Gum chewing affects standardized math scores in adolescents  

Microsoft Academic Search

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 during class and testing, or

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

114

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

115

Keep Gum Disease Away! | NIH MedlinePlus the Magazine  

MedlinePLUS

... this page please turn Javascript on. Feature: Fighting Gum Disease Keep Gum Disease Away! Past Issues / Fall 2010 Table of ... repair damage resulting from uncared-for teeth and gums. Photo: Frederic Havens "Take care of your teeth, ...

116

[A chewing gum with mineral additives].  

PubMed

Finely dispersed hen egg shell was added to a new chewing gum as a mineral component. The studies carried out in 28 schoolchildren have shown that 15 min chewing of this gum results in a marked elevation of salivary Ca levels and in improvement of the hygienic status of the oral cavity. This fact recommends this chewing gum as an additional means for care of the oral cavity for both hygienic purposes and for improving the mineralizing potential of the saliva. PMID:1412556

Skliar, V E; Tereshina, T P

117

Caffeine gum minimizes sleep inertia.  

PubMed

Naps are an effective strategy for maintaining alertness and cognitive performance; however, upon abrupt wakening from naps, sleep inertia (temporary performance degradation) may ensue. In the present study, attenuation of post-nap sleep inertia was attempted by administration of caffeine gum. Using a double-blind, placebo-controlled crossover design, 15 healthy, non-smoking adults were awakened at 1 hr. and again at 6 hr. after lights out (0100 and 0600, respectively) and were immediately administered a gum pellet containing 100 mg of caffeine or placebo. A 5-min. psychomotor vigilance task was administered at 0 min., 6 min., 12 min., and 18 min. post-awakening. At 0100, response speed with caffeine was significantly better at 12 min. and 18 min. post-awakening compared to placebo; at 0600, caffeine's effects were evident at 18 min. post-awakening. Caffeinated gum is a viable means of rapidly attenuating sleep inertia, suggesting that the adenosine receptor system is involved in sleep maintenance. PMID:23829154

Newman, Rachel A; Kamimori, Gary H; Wesensten, Nancy J; Picchioni, Dante; Balkin, Thomas J

2013-02-01

118

Effects on Whole Saliva of Chewing Gums Containing Calcium Phosphates  

Microsoft Academic Search

To evaluate chewing gums as a vehicle to increase salivary mineral saturation levels and enhance salivation, monocalcium phosphate monohydrate (MCPM) and an equimolar mixture of tetracalcium phosphate (TTCP) with dicalcium phosphate anhydrous (DCPA) were chosen as experimental chewing gum additives. Each of eight subjects chewed a commercial sugarless bubble gum (control) for 16 min or the same gum to which

L. C. Chow; S. Takagi; R. J. Shern; T. H. Chow; K. K. Takagi; B. A. Sieck

1994-01-01

119

AN IMPROVED METHOD OF TAPPING GUM FROM KULLU STERCULIA URENS  

Microsoft Academic Search

Kullu or gum karaya (Sterculia urens) is a gum-yielding tree found in the dry deciduous forests of Madhya Pradesh, India. The tree is source of an important gum called kullu gum, gum karaya or katira. Katiraa nationalized forest product in Madhya Pradeshis commercially and industrially very important. The Saheriyasa forest dependent tribal community of Sheopurextract katira from naturally growing kullu

PRODYUT BHATTACHARYA; BHARATI JOSHI; SEYED FAIZ HAYAT

2003-01-01

120

Tips for Removing Gum without Cutting Hair  

MedlinePLUS

For the public Diseases and treatments Health and beauty General skin care Hair care Tips for healthy ... series Home Dermatology A to Z Health and beauty Hair care Removing gum without cutting hair Tips ...

121

Modification of hydroxypropyl guar gum with ethanolamine.  

PubMed

A new guar gum derivative containing amino group was synthesized through nucleophilic substitution of p-toluenesulfonate activated hydroxypropyl guar gum with ethanolamine. For the preparation of p-toluenesulfonate esters hydroxypropyl guar gum, the results showed that the reaction rate was optimal at 25 C and the reaction could reach equilibrium state when it was carried out for 10h at 25 C. For the nucleophilic substitution of tosyl group with ethanolamine, the reaction was completed after 10h reaction at 50 C. The structures of products were characterized by NMR and FT-IR spectroscopy. The results showed that the p-toluenesulfonate esters can be effectively substituted by ethanolamine to form the hydroxyethyl amino hydroxypropyl guar gum (EAHPG). The content of nitrogen of EAHPG was determined by acid-base titration and element analysis. PMID:22840030

Zhao, Yongchao; He, Jianping; Han, Xiaoxiao; Tian, Xiulin; Deng, Mingyu; Chen, Weiping; Jiang, Bo

2012-06-20

122

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

123

Does Your Chewing Gum Lose Its Flavor?  

NSDL National Science Digital Library

In the first part of the activity, each student chews a piece of gum until it loses its flavor, 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 of four to design and conduct new experiments based on questions of their own choosing. These questions arise naturally from observations that occur 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

124

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

2012-07-11

125

Hydroxyapatite/gelatin/gellan sponges as nanocomposite scaffolds for bone reconstruction.  

PubMed

The aim of this work was the morphological, physicochemical, mechanical and biological characterization of a new composite system, based on gelatin, gellan and hydroxyapatite, and mimicking the composition of natural bone. Porous scaffolds were prepared by freeze-drying technique, under three different conditions of freezing. The morphological analysis showed a homogeneous porosity, with well interconnected pores, for the sample which underwent a more rapid freezing. The elastic modulus of the same sample was close to that of the natural bone. The presence of interactions among the components was demonstrated through the physicochemical investigation. In addition, the infrared chemical imaging analysis pointed out the similarity among the composite scaffold and the natural bone, in terms of chemical composition, homogeneity, molecular interactions and structural conformation. Preliminary biological characterization showed a good adhesion and proliferation of human mesenchymal stem cells. PMID:22116662

Barbani, Niccoletta; Guerra, Giulio D; Cristallini, Caterina; Urciuoli, Patrizia; Avvisati, Riccardo; Sala, Alessandro; Rosellini, Elisabetta

2011-11-25

126

REMINERALIZATION OF ENAMEL SUBSURFACE LESIONS BY XYLITOL CHEWING GUM CONTAINING FUNORAN AND CALCIUM HYDROGENPHOSPHATE  

Microsoft Academic Search

The aim of the present study was to determine the remineralization effects of xylitol chewing gum containing funoran and calcium hydrogenphosphate on enamel subsurface lesions in humans. The study was a double-blind, randomized, cross-over design, with 4 types of gum: (1) xylitol gum, (2) xylitol gum containing funoran and calcium hydrogenphosphate, (3) sugar gum, and (4) gum base as a

Sroisiri Thaweboon; Siriruk Nakornchai; Yasuo Miyake; Takaaki Yanagisawa; Boonyanit Thaweboon; Surin Soo-ampon; Duangjai Lexomboon

2009-01-01

127

The classification of natural gums. X. Chemometric characterization of exudate gums that conform to the revised specification of the gum arabic for food use, and the identification of adulterants  

Microsoft Academic Search

Fifty-four individual authenticated or commercial exudate gums were collected from the gum arabic producing countries of Africa as part of an FAO project to clarify the factors which influence the specification of gum arabic additive (Acacia gum INS 414) used in food. Seven analytical parameters were measured for each gum: specific optical rotation, intrinsic viscosity, content of nitrogen (and hence

J. Mocak; P. Jurasek; G. O. Phillips; S. Varga; E. Casadei; B. N. Chikemai

1998-01-01

128

21 CFR 184.1343 - Locust (carob) bean gum.  

Code of Federal Regulations, 2010 CFR

...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...

2010-01-01

129

21 CFR 184.1343 - Locust (carob) bean gum.  

Code of Federal Regulations, 2010 CFR

...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...

2009-04-01

130

Interstellar gas in the Gum Nebula  

SciTech Connect

We have surveyed the interstellar gas in and around the Gum Nebula by optically observing 67 stars at Ca II, 42 stars at Na I, and 14 stars in the ultraviolet with the Copernicus satellite. Velocity dispersions for gas in the Gum Nebula, excluding the region of Vela remnant filaments, are not significantly larger than in the general interstellar medium. The ionization structure is predominantly that of an H II region with moderately high ionization, i.e., strong Si III and S III, in clouds with Vertical BarV/sub LSR/Vertical Bar> or approx. =10 km s/sup -1/. Furthermore, we find an increase in fine-structure excitation with increasing component LSR velocity, suggestive of ram-pressure confinement for the intermediate-velocity clouds. These denser, more highly ionized clouds appear to be concentrated toward the inner Gum Nebula, where a somewhat higher velocity dispersion is found than in the outer regions. Clouds in the Gum Nebula do not show the anomalously high ionization seen in the Vela remnant clouds. The observational data are generally consistent with a model of the Gum Nebula as an H II region ionized by OB stars and stirred up by multiple stellar winds.

Wallerstein, G.; Silk, J.; Jenkins, E.B.

1980-09-15

131

Different approaches of katira gum formulations for colon targeting  

Microsoft Academic Search

The objective of the study is to compare the different formulations prepared by using gum, grafted gum and hydrogel of katira as a carrier for colon-specific drug delivery using in vitro methods with and without enzymes. Katira gum is naturally occurring polysaccharides containing mainly l-rhamnose and d-galactose sugar unit and small percent of d-galactouronic acid. Compared to grafted gum and

B. Bharaniraja; K. Jayaram Kumar; C. M. Prasad; A. K. Sen

2011-01-01

132

Investigation and comparison of colon specificity of novel polymer khaya gum with guar gum.  

PubMed

To investigate the colon specificity of novel natural polymer khaya gum and compare with guar gum. Release profile of tablets was carried out in presence and absence of rat cecal contents. The fast disintegrating core tablets of budesonide, were initially prepared by direct compression technique. Later, these tablets were coated with khaya gum or guar gum. After suitable pre compression and post compression evaluation, these tablets were further coated using Eudragit L-100 by dip coating technique. X-ray images were taken to investigate the movement, location and the integrity of the tablets in different parts of gastro intestinal tract in rabbits. The release profiles revealed that khaya gum or guar gum, when used as compression coating, protected the drug from being released in the upper parts of the gastro intestinal tract to some extent but the enteric coated formulations completely protected the drug from being released in the upper parts of the gastro intestinal tract, and released the drug in the colon by bacterial degradation of gums. It was found that both the polysaccharide polymers exhibited different release profiles in presence and absence of rat cecal contents. However, further enteric coat helped in targeting the drug to colon very effectively. Better dissolution models revealed the colon specificity of polysaccharides and alone can not be used either for targeting the drug to the colon or for sustaining or controlling the release of drug. PMID:20566437

Prabhu, Prabhakara; Ahamed, Nissara; Matapady, Harish Nairy; Ahmed, Mohd Gulzar; Narayanacharyulu, R; Satyanarayana, D; Subrahmanayam, Evs

2010-07-01

133

78 FR 43226 - Xanthan Gum From Austria and China  

Federal Register 2010, 2011, 2012, 2013

...731-TA-1202-03 (Final)] Xanthan Gum From Austria and China Determinations On...reason of imports from Austria of xanthan gum provided for in subheading 3913.90.20...reason of imports from China of xanthan gum provided for in subheading...

2013-07-19

134

Novel Lannea Woodier gum matrices for controlled release of drugs  

Microsoft Academic Search

The objective of the study is to establish the potential of Odina gum as a novel pharmaceutical aid for development of controlled release drug delivery systems. The influence of varying the proportion of the gum, the nature of diluents and their ratio in the preparation was also evaluated. Compatibility of the drugs with the gum was studied using FTIR and

V. R. Sinha; Azaki Ahmed Al-Azaki; R. V. Kumar

2011-01-01

135

Influence of Nicotine Gum on Acute Cravings for Cigarettes  

Microsoft Academic Search

Reviews of nicotine gum trials generally confirm the efficacy of this substitute in smoking cessation. However, little research has considered the efficacy of nicotine gum as a method for alleviating acute cravings in situations where smokers are not permitted to smoke. The aim of the present study was to evaluate the efficacy of nicotine gum in alleviating acute cravings for

G. M. Davies; P. Willner; D. L. James; M. J. Morgan

2004-01-01

136

Natural gums and modified natural gums as sustained-release carriers.  

PubMed

Although natural gums and their derivatives are used widely in pharmaceutical dosage forms, their use as biodegradable polymeric materials to deliver bioactive agents has been hampered by the synthetic materials. These natural polysaccharides do hold advantages over the synthetic polymers, generally because they are nontoxic, less expensive, and freely available. Natural gums can also be modified to have tailor-made materials for drug delivery systems and thus can compete with the synthetic biodegradable excipients available in the market. In this review, recent developments in the area of natural gums and their derivatives as carriers in the sustained release of drugs are explored. PMID:11028217

Bhardwaj, T R; Kanwar, M; Lal, R; Gupta, A

2000-10-01

137

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

138

Effects on whole saliva of chewing gums containing calcium phosphates.  

PubMed

To evaluate chewing gums as a vehicle to increase salivary mineral saturation levels and enhance salivation, monocalcium phosphate monohydrate (MCPM) and an equimolar mixture of tetracalcium phosphate (TTCP) with dicalcium phosphate anhydrous (DCPA) were chosen as experimental chewing gum additives. Each of eight subjects chewed a commercial sugarless bubble gum (control) for 16 min or the same gum to which 5 wt% of MCPM or the TTCP-DCPM mixture had been added. The saliva samples collected every 2 min were analyzed for weight, pH, and total calcium (Ca) and phosphate (P) concentrations. Both experimental gums were found to increase significantly the Ca and P concentrations of saliva during the 16-minute period even more than with a previously evaluated gum that contained dicalcium phosphate dihydrate. The degree of saturation of tooth mineral was significantly increased by both experimental gums, with the greater increase being produced by the TTCP-DCPA gum. The MCPM gum produced a significantly greater saliva flow and a lower salivary pH than did the control and TTCP-DCPA gums. The results suggest that the experimental gums may be useful for promoting remineralization in general and for inducing salivation in xerostomic patients. PMID:8294615

Chow, L C; Takagi, S; Shern, R J; Chow, T H; Takagi, K K; Sieck, B A

1994-01-01

139

Different approaches of katira gum formulations for colon targeting.  

PubMed

The objective of the study is to compare the different formulations prepared by using gum, grafted gum and hydrogel of katira as a carrier for colon-specific drug delivery using in vitro methods with and without enzymes. Katira gum is naturally occurring polysaccharides containing mainly l-rhamnose and d-galactose sugar unit and small percent of d-galactouronic acid. Compared to grafted gum and hydrogel, all proportions of katira gum protect the drug from being released completely in the physiological environment of the stomach and small intestine. In vitro release studies in enzymes (Pectinex Ultra SP-L having galactouronidase activity) have demonstrated the susceptibility of katira gum to the colonic bacterial enzyme (galactouronidase activity from Pectinex Ultra SP-L) with a consequent drug release. It illustrates that katira gum, a natural polysaccharide may be suitable as a carrier for colon targeting. PMID:21600918

Bharaniraja, B; Jayaram Kumar, K; Prasad, C M; Sen, A K

2011-05-11

140

The oral health benefits of chewing gum.  

PubMed

The use of sugar-free gum provides a proven anti-caries benefit, but other oral health effects are less clearly elucidated. Chewing sugar-free chewing gum promotes a strong flow of stimulated saliva, which helps to provide a number of dental benefits: first, the higher flow rate promotes more rapid oral clearance of sugars; second, the high pH and buffering capacity of the stimulated saliva help to neutralise plaque pH after a sugar challenge; and, lastly, studies have shown enhanced remineralisation of early caries-like lesions and ultimately prospective clinical trials have shown reduced caries incidence in children chewing sugar-free gum. This paper reviews the scientific evidence for these functional claims and discusses other benefits, including plaque and extrinsic stain reduction, along with the possibility of adding specific active agents, including fluoride, antimicrobials, urea and calcium phosphates, to enhance these inherent effects. The evidence for a specific effect of xylitol as a caries-therapeutic agent is also discussed. In conclusion, it is asserted that chewing gum has a place as an additional mode of dental disease prevention to be used in conjunction with the more traditional preventive methods. PMID:23573702

Dodds, Michael W J

141

21 CFR 582.3336 - Gum guaiac.  

Code of Federal Regulations, 2013 CFR

21 Food and Drugs 6 2013-04-01 2013-04-01... 582.3336 Section 582.3336 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT...GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3336 Gum guaiac....

2013-04-01

142

Xanthan gum: production, recovery, and properties  

Microsoft Academic Search

Xanthan gum is a microbial polysaccharide of great commercial significance. This review focuses on various aspects of xanthan production, including the producing organism Xanthomonas campestris, the kinetics of growth and production, the downstream recovery of the polysaccharide, and the solution properties of xanthan.

F Garc??a-Ochoa; V. e. Santos; J. a. Casas; E. Gomez

2000-01-01

143

Effect of a glassy gellan/polydextrose matrix on the activity of ?-D-glucosidase.  

PubMed

An investigation of the ability of the enzyme ?-D-glucosidase to act on the substrate 4-nitrophenyl ?-D-glucopyranoside (pNPG) while embedded in glassy carbohydrate matrices (deacylated gellan with polydextrose and polydextrose alone) is presented. Physicochemical characterisation of the matrices was achieved using the techniques of modulated differential scanning calorimetry, small deformation dynamic oscillation on shear, Fourier transform infra-red spectroscopy, wide angle X-ray diffraction and scanning electron microscopy. A UV-vis spectrophotometric procedure was adapted for the analysis of the activity of ?-D-glucosidase in hydrolysing pNPG in the condensed carbohydrate systems. In order to derive a relationship between the structural properties of the matrix and the enzymatic activity, mechanical spectra were recorded using the combined framework of the Williams, Landel and Ferry equation with the time-temperature superposition principle. Theoretical modelling and experimental observations strongly argue for a pronounced effect of the gelling polysaccharide/co-solute mixture on enzymatic activity near the mechanical Tg of the matrix. PMID:23618284

Chaudhary, Vinita; Small, Darryl M; Kasapis, Stefan

2013-03-13

144

Biodegradation of Xanthan Gum by Bacillus sp  

PubMed Central

Strains tentatively identified as Bacillus sp. were isolated from sewage sludge and soil and shown to elaborate extracellular enzymes that degrade the extracellular polysaccharide (xanthan gum, polysaccharide B-1459) of Xanthomonas campestris NRRL B-1459. Enzyme production by one strain was greatly enhanced when the strain was incubated in a mixed culture. Products of degradation were identified as d-glucuronic acid, d-mannose, pyruvylated mannose, 6-O-acetyl d-mannose, and a (1?4)-linked glucan. These products correlate with the known structure of the gum. The complexity of the product mixture indicated that the xanthanase was a mixture of carbohydrases. The xanthanase complexes were similar to one another in temperature stability, pH and temperature optima, degree of substrate degradation, and enzymolysis products. Differences in pH stability, salt tolerance, recoverability, and yields of enzyme were observed.

Cadmus, Martin C.; Jackson, Linda K.; Burton, Kermit A.; Plattner, Ronald D.; Slodki, Morey E.

1982-01-01

145

40 CFR 454.20 - Applicability; description of the manufacture of gum rosin and turpentine subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the manufacture of gum rosin and turpentine subcategory. 454...CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GUM AND WOOD CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Gum Rosin and Turpentine Subcategory §...

2010-07-01

146

40 CFR 454.20 - Applicability; description of the manufacture of gum rosin and turpentine subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the manufacture of gum rosin and turpentine subcategory. 454...CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GUM AND WOOD CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Gum Rosin and Turpentine Subcategory §...

2009-01-01

147

40 CFR 454.20 - Applicability; description of the manufacture of gum rosin and turpentine subcategory.  

Code of Federal Regulations, 2011 CFR

...Applicability; description of the manufacture of gum rosin and turpentine subcategory. 454...CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GUM AND WOOD CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Gum Rosin and Turpentine Subcategory §...

2011-07-01

148

77 FR 65361 - Xanthan Gum From Austria and the People's Republic of China: Postponement of Preliminary...  

Federal Register 2010, 2011, 2012, 2013

...A-433-811, A-570-985] Xanthan Gum From Austria and the People's Republic...antidumping duty investigations of xanthan gum from Austria and the People's Republic...1\\ See Xanthan Gum From Austria and the People's...

2012-10-26

149

Use of Seed Gums in Low-Fat Ground Pork  

Microsoft Academic Search

Consumer demand for low-fat meat products has increased. Low-fat meat products have decreased palatability. Decreased fat content in ground meats has been associated with decreased juiciness and tenderness. Gums have been reported to retain moisture and improve overall textural characteristics of ground beef Therefore, the objective of this study was to investigate the effects of seed gums, i.e., guar gum

H. Ligutom; A. Mesina; V. Ganji

1999-01-01

150

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

151

Smart reticulated hydrogel of functionally decorated gellan copolymer for prolonged delivery of salbutamol sulphate to the gastro-luminal milieu.  

PubMed

A partially hydrolysed poly(acrylamide)-grafted-gellan (HPAmGG) copolymer was synthesised and characterised. Temperature- and concentration-dependent rheology and gel-like property of Gelrite gellan (GG) disappeared in HPAmGG copolymer. Smart HPAmGG hydrogel was fabricated with variation in aluminium chloride (AlCl(3)) strength and initial drug loading. The hydrogel reticulates seemed spherical and showed a maximum of ?65% drug retention, but the assay was ?22% lower for GG hydrogel. The drug release rate was inversely proportional to AlCl(3) strength in simulated intestinal milieu (pH 7.4), but approximated a proportional relationship with drug load. HPAmGG hydrogel liberated only 10-17% content in simulated gastric milieu (pH 1.2) in 2?h. The release data correlated well with the pH-dependent swelling of hydrogel and indicated the anomalous drug diffusion mechanism. Differential scanning calorimetry, X-ray diffraction, and high-performance liquid chromatography analyses confirmed the amorphous nature of the drug and its stability in fresh and aged hydrogel. Hence, smart HPAmGG hydrogel had the potential to prolong drug release mimicking the variable pH of the gastrointestinal tract. PMID:22594768

Maiti, Sabyasachi; Ghosh, Sudipa; Mondol, Ranjit; Ray, Somasree; Sa, Biswanath

2012-05-17

152

Starchcassia gum interactions: A microstructure Rheology study  

Microsoft Academic Search

We present for the first time the interactions of starch and cassia gum a novel galactomannan recently approved for use in food processing. Viscoelastic, pasting and microstructural characterization of various starches (waxy; high amylose; normal; cross-linked waxy corn starch; potato starch) containing different levels of the cassia gum was carried out. Significant changes were observed in the morphology of

Lovedeep Kaur; Jaspreet Singh; Harjinder Singh; Owen J. McCarthy

2008-01-01

153

GRAS (Generally Recognized as Safe) Food Ingredients - Guar Gum.  

National Technical Information Service (NTIS)

The report summarizes the available scientific literature from 1920 to 1972 related to the 'safety' of guar gum as a food ingredient. Chemical information, biological data, and biochemical aspects of guar gum are given in a 35 page summary containing 116 ...

1972-01-01

154

Production of xanthan gum from a chemically defined medium introduction  

Microsoft Academic Search

Heteropolysaccharides produced by the action of Xanthomonas bacteria on carbohydrate media have a potential application as film forming agents, as thickeners in oil field drilling fluids and fracturing liquids and as emulsifying, stabilizing, and sizing agents. Heteropolysaccharides, particularly, xanthan gum, have a significant potential as mobility control agents in micellar polymer flooding. Xanthan gum has excellent viscosifying properties at low

W. P. Weisrock; H. S. Klein

1983-01-01

155

Current evidence on the anticancer potential of Chios mastic gum.  

PubMed

Chios mastic gum derived from the plant Pistacia lentiscus L. variation chia has been shown to exert beneficial effects on a wide range of human disorders. The most comprehensive data so far have indicated that mastic gum provides protection against gastrointestinal malfunctions and bacterial infections. Substantial evidence has also suggested that mastic gum exhibits hepatoprotective and cardioprotective, antiinflammatory/antioxidant, and antiatherogenic properties. In the last decade, an increasing number of studies further evaluated the potential antiproliferative properties of mastic gum against several types of human neoplasia. The present review aims to summarize the current data concerning the anticancer activities of mastic gum and their major constituents, highlighting also the molecular mechanisms through which they exert anticancer function. Mastic gum constituents that belong to the chemical class of triterpenoids appear to be mainly responsible for its anticancer potential. Thus, a brief discussion is dedicated to the anticancer activity of synthetic and naturally occurring triterpenoid analogues with similar chemical structure to mastic gum constituents. Taking into consideration the available data so far, Chios mastic gum could be considered as a conglomeration of effective anticancer drugs. PMID:22044444

Giaginis, Constantinos; Theocharis, Stamatios

2011-11-01

156

Impact of welan gum on tricalcium aluminate-gypsum hydration  

SciTech Connect

The retarding effect of welan gum on tricalcium aluminate-gypsum hydration, as a partial system of ordinary Portland cement (OPC) hydration, was investigated with several methods. The tricalcium aluminate-gypsum hydration behavior in the presence or absence of welan gum was researched by field emission gun scanning electron microscopy, X-ray diffraction and zeta potential analysis. Meanwhile, we studied the surface electrochemical properties and adsorption characteristics of welan gum by utilizing a zeta potential analyzer and UV-VIS absorption spectrophotometer. By adding welan gum, the morphology change of ettringite and retardation of hydration stages in tricalcium aluminate-gypsum system was observed. Moreover, we detected the adsorption behavior and zeta potential inversion of tricalcium aluminate and ettringite, as well as a rapid decrease in the zeta potential of tricalcium aluminate-gypsum system. The reduction on nucleation rate of ettringite and hydration activity of C{sub 3}A was also demonstrated. Thus, through the adsorption effect, welan gum induces a retarding behavior in tricalcium aluminate-gypsum hydration. Highlights: Black-Right-Pointing-Pointer Adsorption characteristics of welan gum on C{sub 3}A and ettringite have been studied. Black-Right-Pointing-Pointer C{sub 3}A-gypsum hydration behavior and the hydration products are examined in L/S = 3. Black-Right-Pointing-Pointer Welan gum retards the process of C{sub 3}A-gypsum hydration. Black-Right-Pointing-Pointer The addition of welan gum changes the nucleation growth of ettringite.

Ma Lei, E-mail: malei198713@163.com; Zhao Qinglin, E-mail: zhaoqinglin@whut.edu.cn; Yao Chukang; Zhou Mingkai

2012-02-15

157

Marketing Chewing Gum: A Case Study of a Cypriot Company  

Microsoft Academic Search

The purpose of this article is to examine the issues related to the chewing gum marketing practices employed by a Cypriot company importing gum. Thus, the product, its target market, and competition are examined, a SWOT analysis is performed and the marketing mix is presented. Then the results are compared with the international market.The case study method was employed to

Evangelia K. Blery; Loukas Antoniades

2010-01-01

158

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

2011-06-13

159

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.

Viinanen, Arja; Salokannel, Maija; Lammintausta, Kaija

2011-01-01

160

Safety assessment and caloric value of partially hydrolyzed guar gum.  

PubMed

Guar gum and partially hydrolyzed guar gum (PHGG) are food ingredients that have been available for many years. PHGG is the partially hydrolyzed product from guar gum obtained from the Indian cluster bean (Cyanopsis tetragonolopus). The gum (CAS Registry No. 9000-30-0) is composed of galactomannan, a gel-forming polysaccharide with a molecular weight ranging from 200 to 300 kDa. The intact and partially hydrolyzed forms have multiple food applications. The intact material can be used to control the viscosity, stability, and texture of foods. PHGG is highly soluble and has little physical impact on foods. Both forms are indigestible but are excellent sources of fermentable dietary fiber. The caloric value of intact guar gum is accepted as 2.0, whereas the caloric value of PHGG has not been firmly established. It is the goal of this paper to review the chemistry, safety, in vivo effects, and caloric value of PHGG. PMID:23347282

Finley, John W; Soto-Vaca, Adriana; Heimbach, James; Rao, T P; Juneja, Lekh Raj; Slavin, Joanne; Fahey, George C

2013-02-12

161

Gum and deposit formation from jet turbine and diesel fuels  

SciTech Connect

The present paper describes measurements of rates of oxidation and soluble gum formation in both pure hydrocarbons and in mixed hydrocarbon fuels. Some patterns which appear can be explained on the basis of what is known about co-oxidation of hydrocarbon mixtures. The oxidations were conducted in an oil bath at 130/sup 0/C. Gum formation is closely associated with oxidation. The compounds that copolymerize with oxygen to produce polyperoxides require the least amount of oxygen to yield a mg of gum; among other pure hydrocarbons and fuels, the rates of gum formation and oxygen absorption decrease together. The most useful approach to understanding and reducing gum and deposit formation will come through understanding the effects of condensed aromatic and heterocyclic compounds on the oxidation rates of fuels. 4 figures. 4 tables.

Mayo, F.R.; Lan, B.Y.

1983-09-01

162

Microbial contamination of gum elastic bougies.  

PubMed

The gum elastic bougie is a simple device that is used to assist in the management of the difficult intubation. It is not uncommon for a bougie to be re-used many times. This study investigated the incidence of microbial contamination of the bougies in one hospital. Potentially pathogenic organisms were identified both on the bougies and in their storage containers. This has implications for their cleaning and maintenance, and raises the question as to whether we should replace them with single-use, disposable devices. PMID:10792139

Cupitt, J M

2000-05-01

163

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

2008-02-05

164

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 acaciasugarcalcium 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 7983% 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.

Aslani, Abolfazl; Rafiei, Sahar

2012-01-01

165

Smokeless tobacco abstinence effects and nicotine gum dose.  

PubMed

There were two experiments on abstinence from smokeless tobacco. The purpose of the first experiment was to determine abstinence effects from smokeless tobacco. The purpose of the second experiment was to examine the effects of different doses of nicotine gum on smokeless tobacco abstinence effects. The subjects were male Copenhagen smokeless tobacco users who underwent 3 days of baseline measurement while continuing to use smokeless tobacco ad libitum, and 5 days of the experimental condition. In the first experiment, the subjects were assigned randomly to one of two groups and compared: continuous smokeless tobacco users (n = 10), and deprivation plus no nicotine gum (n = 10). In the second experiment, subjects were assigned randomly and in a double-blind fashion to one of three groups and compared: (1) deprivation plus 0 mg nicotine gum (n = 20); (2) deprivation plus 2 mg nicotine gum (n = 20); and (3) deprivation plus 4 mg nicotine gum (n = 20). The first experiment showed significant increases upon abstinence for the following variables: (1) craving; (2) difficulty concentrating; (3) restlessness; (4) excessive hunger; (5) eating; (6) reaction time; (7) variability of reaction time and (8) total withdrawal scores for both the self-rated and the observer-rated forms. The second experiment showed that nicotine gum failed to significantly reduce smokeless tobacco abstinence effects, although those with high cotinine levels may receive some benefit from nicotine gum. PMID:1738794

Hatsukami, D; Anton, D; Keenan, R; Callies, A

1992-01-01

166

Influence of nicotine gum on acute cravings for cigarettes.  

PubMed

Reviews of nicotine gum trials generally confirm the efficacy of this substitute in smoking cessation. However, little research has considered the efficacy of nicotine gum as a method for alleviating acute cravings in situations where smokers are not permitted to smoke. The aim of the present study was to evaluate the efficacy of nicotine gum in alleviating acute cravings for cigarettes using the subjective multi-dimensional Questionnaire of Smoking Urges (QSU) and the objective progressive ratio (PR) measures of craving. Forty-five regular smokers participated in a double-blind placebo-controlled trial. All participants were required to abstain from cigarettes for a period of 4 h. Fifteen of the participants were required to chew nicotine gum, 15 were required to chew placebo gum and 15 received no intervention during this abstinence period. All participants then completed the QSU, PR and mood and anxiety questionnaires. The results revealed that participants who had been in either of the gum conditions reported significantly lower QSU factor 1 and factor 2 craving scores after 4 h abstinence than those who had received no intervention. Although a significant partial correlation between QSU factor 1 and 2 scores and the number of reinforcers earned under the PR procedure was observed, the results revealed no significant difference between groups on measures of PR performance or mood and anxiety. Both nicotine and placebo gum are equally effective at reducing acute cravings for cigarettes. PMID:15107189

Davies, G M; Willner, P; James, D L; Morgan, M J

2004-03-01

167

Randomised controlled trial of nicotine chewing-gum.  

PubMed Central

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 the most stringent criterion of outcome, 18 (31%) subjects in the active treatment group and eight (14%) in the placebo group had not smoked at all from the start of treatment to follow-up at one year (p less than 0.05). Subjects receiving the active gum experienced less severe withdrawal symptoms and rated their gum as more helpful than did the placebo group. Minor side effects were common but only gastric symptoms were more frequent with the active gum. Subjects receiving active gum used it for longer than those receiving placebo but most stopped using it within six months and only four (7%) developed longer-term dependence. The number of gums used daily correlated significantly with pretreatment blood nicotine concentrations in the active treatment group and with pretreatment cigarette consumption in the placebo group. A lower pretreatment blood nicotine value was the best predictor of success at one year (p less than 0.001) but there was no significant relation to cigarette consumption, sex, and social class. The results clearly confirm the usefulness of nicotine chewing-gum as an aid to stopping smoking and imply a definite role for nicotine in cigarette dependence and withdrawal. Successful use of the gum requires careful attention to subjects' expectations and clear instructions on how to use it.

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

1982-01-01

168

Identification of Intestinal Bacteria Responsible for Fermentation of Gum Arabic in Pig Model  

Microsoft Academic Search

Acacia spp. produce gum exudates, traditionally called gum arabic or gum acacia, which are widely used in the food industry such\\u000a as emulsifiers, adhesives, and stabilizers. The traditional gum arabic is highly variable with average molecular weights varying\\u000a from 300,000800,000. For this reason a standardized sample was used for the present experiments, based on a specific species\\u000a of gum arabic

Akio Kishimoto; Kazunari Ushida; Glyn O. Phillips; Takashi Ogasawara; Yasushi Sasaki

2006-01-01

169

Pasting and rheological properties of waxy corn starch as affected by guar gum and xanthan gum  

Microsoft Academic Search

Effects of guar (GG) and xanthan (XG) gums (0.351.0% w\\/w) on pasting and rheological properties of waxy corn starch (WCS) (6.0% w\\/w) were studied. GG had a higher molecular weight but lower intrinsic viscosity than did XG, indicating that the GG chain was more flexible. RVA results indicated that viscosity and pasting temperature of the WCS dispersion during pasting increased

Piyada Achayuthakan; Manop Suphantharika

2008-01-01

170

Structural assignment of a heteropolysaccharide isolated from the gum of Cochlospermum religiosum (Katira gum).  

PubMed

A heteropolysaccharide isolated from the gum (Katira) of Cochlospermum religiosum was found to consist of D-galactose, D-galacturonic acid and L-rhamnose in a molar ratio 2:1:3. Structural assignment of the polysaccharide was carried out using total acid hydrolysis, methylation analysis, periodate oxidation, Smith degradation and NMR studies (1H, 13C, DQF-COSY, TOCSY, NOESY, HMBC and HSQC) and the repeating unit of the polysaccharide was established as [Formula: see text]. PMID:18374321

Ojha, Arnab K; Maiti, Debabrata; Chandra, Krishnendu; Mondal, Subhas; Das Sadhan K Roy, Debsankar; Ghosh, Kaushik; Islam, Syed S

2008-03-13

171

Structural assignment of a heteropolysaccharide isolated from the gum of Cochlospermum religiosum (Katira gum)  

Microsoft Academic Search

A heteropolysaccharide isolated from the gum (Katira) of Cochlospermum religiosum was found to consist of d-galactose, d-galacturonic acid and l-rhamnose in a molar ratio 2:1:3. Structural assignment of the polysaccharide was carried out using total acid hydrolysis, methylation analysis, periodate oxidation, Smith degradation and NMR studies (1H, 13C, DQF-COSY, TOCSY, NOESY, HMBC and HSQC) and the repeating unit of the

Arnab K. Ojha; Debabrata Maiti; Krishnendu Chandra; Subhas Mondal; Debsankar Das Sadhan K. Roy; Kaushik Ghosh; Syed S. Islam

2008-01-01

172

Production of xanthan gum from a chemically defined medium introduction  

SciTech Connect

Heteropolysaccharides produced by the action of Xanthomonas bacteria on carbohydrate media have a potential application as film forming agents, as thickeners in oil field drilling fluids and fracturing liquids and as emulsifying, stabilizing, and sizing agents. Heteropolysaccharides, particularly, xanthan gum, have a significant potential as mobility control agents in micellar polymer flooding. Xanthan gum has excellent viscosifying properties at low concentration, is resistant to shear degradation and exhibits only minimal losses in viscosity as a function of temperature, pH, and ionic strength. For these reasons, xanthan gum is an attractive alternative to synthetic polyacrylamides for enhanced oil recovery operations. 15 claims.

Weisrock, W.P.; Klein, H.S.

1983-02-22

173

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

2013-06-29

174

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

175

Evaluation of mucoadhesive potential of gum cordia, an anionic polysaccharide.  

PubMed

The study involves mucoadhesive evaluation by formulating buccal discs using fluconazole as the model drug. The effect of compression pressure and gum cordia/lactose ratio on the ex vivo bioadhesion time and in vitro release of fluconazole was optimized using central composite experimental design. It was observed that the response ex vivo bioadhesion time was affected significantly by the proportion of gum cordia in the buccal discs while the in vitro release of fluconazole from the buccal discs was influenced significantly by the compression pressure. The optimized batch of buccal discs comprised of gum cordia/lactose - 0.66, fluconazole - 20 mg and was compressed at the pressure of 6600 kg. Further, it provided the ex vivo bioadhesion of 22 h and in vitro release of 80% in 24h. In conclusion, gum cordia is a promising bucoadhesive polymer. PMID:23280130

Ahuja, Munish; Kumar, Suresh; Kumar, Ashok

2012-12-29

176

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

177

Hydrolysis of plant seed gums by microwave irradiation  

Microsoft Academic Search

Under microwave irradiation (MW), the seed gums, guar and Ipomoea quamoclit were hydrolyzed to constituent monosaccharides and oligosaccharides in very mild conditions and short reaction time. Under MW both the seed gums could be completely hydrolyzed using very dilute acid (0.00625N H2SO4) within two minutes. Hydrolysis occurs in 2 min and 20 s even in absence of acid under the

Vandana Singh; Rupali Sethi; Ashutosh Tewari; Vasundhara Srivastava; Rashmi Sanghi

2003-01-01

178

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 711 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

179

Apparent viscosity of co-extruded starch and xanthan gum  

Microsoft Academic Search

Xanthan gum is a polysaccharide which forms viscous, pseudoplastic aqueous solutions useful in numerous food and industrial applications. The viscous properties of starch and xanthan gum co-extruded with injection of adipoyl chloride were determined. Viscosities of aqueous solutions of ground extruded and nonextruded samples were compared at different temperatures, NaCl concentrations, and pH's. The effect of ?-amylase at 50 C

V. D. Miladinov; M. A. Hanna

1996-01-01

180

Seasonality in Gum and Honeydew Feeding in Gray Mouse Lemurs  

Microsoft Academic Search

\\u000a Exudates represent an important component of the natural diets of small-bodied primates. For mouse lemurs, the impact of\\u000a forest type and seasonal predictability on gum consumption has recently been intensively investigated. The goal of our study\\u000a was to extend our knowledge regarding the seasonality of feeding ecology of Microcebus murinus, first, to investigate the relative consumption of gum and hemipteran

Marine Joly-Radko; Elke Zimmermann

181

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

182

Xanthan gum biosynthesis and application: a biochemical?\\/genetic perspective  

Microsoft Academic Search

Xanthan gum is a complex exopolysaccharide produced by the plant-pathogenic bacterium Xanthomonas campestris pv. campestris. It consists of D-glucosyl, D-mannosyl, and D-glucuronyl acid residues in a molar ratio of 2:2:1 and variable proportions of O-acetyl and pyruvyl residues. Because of its physical properties, it is widely used as a thickener or viscosifier in both\\u000a food and non-food industries. Xanthan gum

A. Becker; F. Katzen; A. Phler; L. Ielpi

1998-01-01

183

Effect of guar gum on mineral balances in NIDDM adults.  

PubMed

The self-selected diet of 16 subjects with non-insulin-dependent diabetes mellitus (NIDDM) was supplemented for 6 mo with either a granolalike bar containing 35.5 g carbohydrate and 6.6 g guar gum/bar or a placebo bar containing carbohydrate but no guar gum. Subjects consumed a mean of 4.8 bars/day. Average guar gum consumption at the end of the study was 31.7 g/day. One week before and at the end of the study, subjects were admitted to a metabolic ward and fed a controlled diet similar to their self-selected diet. Food, feces, and urine were composited for analysis of iron, zinc, copper, calcium, magnesium, and manganese. Eight subjects consuming the guar gum supplement and 6 subjects consuming the placebo bar completed collections for mineral balance. Neither consumption of guar gum nor placebo bar significantly changed apparent mineral balance for iron, copper, zinc, calcium, manganese, or magnesium from prestudy levels to 6-mo levels, and no significant differences were observed between the two groups. With the exception of copper, men consumed significantly more minerals than women. We conclude that consumption of guar gum by patients with NIDDM does not adversely affect apparent mineral balance. PMID:2541985

Behall, K M; Scholfield, D J; McIvor, M E; Van Duyn, M S; Leo, T A; Michnowski, J E; Cummings, C C; Mendeloff, A I

1989-05-01

184

Cashew gum microencapsulation protects the aroma of coffee extracts.  

PubMed

Microencapsulation of materials rich in volatile compounds by spray drying presents the challenge of removing water by vapourization without loss of odour and/or flavour components. Crioconcentrated coffee extracts rich in odour components were used as a substrate core to evaluate microencapsulation with cashew gum from Anacardium occidentale L. In Brazil, cashew gum is a low cost alternative to the traditional Arabic gum. A suspension containing coffee extract and the wall material was dissolved in water and then passed through a spray dryer. Core microcapsules were microwave-assisted extracted (MAE) and the aroma protection of the microcapsules produced was evaluated using gas chromatography and mass spectroscopy (GC/MS). The external morphology and size distribution of the microcapsules were obtained by scanning electron microscopy (SEM) and light scattering techniques, respectively. When comparing Arabic and cashew gum microencapsulation of coffee extracts both wall materials were observed to have similar aroma protection, external morphology and size distribution. Sensory analysis was employed to examine flavour protection and consumer preference with microencapsulation. These biochemical, sensory and structural data suggest that low cost cashew gum is a well suited alternative for odour microencapsulation to the more costly Arabic gum currently used in Brazil. PMID:18188728

Rodrigues, R A F; Grosso, C R F

2008-02-01

185

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

Federal Register 2010, 2011, 2012, 2013

...Administration [A-433-811] Xanthan Gum From Austria: Preliminary Determination...preliminarily determines that xanthan gum from Austria is being, or is likely to...of this investigation covers dry xanthan gum, whether or not coated or blended...

2013-01-10

186

Physicochemical properties of cissus gum powder extracted with the aid of edible starches.  

PubMed

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-microm sieve. Proximate and physicochemical properties of the gum samples were determined using standard methods. Results of the proximate analyses showed that protein and ash contents of the root gum were appreciably higher than those of the stem gum. Values of the crude fiber and ether extract of the root gum were lower than those of the stem gum. Inclusion of edible starches in the extraction process appreciably lowered proximate values. Results of the physicochemical properties showed that cissus gum samples did not form true gel but a "putty-like" mass. Addition of starches at various levels did not alter the characteristic putty-like nature of the gum. The gum samples had a remarkably low oil absorption capacity. Cissus gum samples had appreciably higher emulsion capacity and stability than the samples containing starch. The pH of the cissus gum powder and those of the starch-containing samples lie in the low-acid range (5.69-6.49). Cissus gum samples were highly hygroscopic; however, the addition of starch lowered the hygroscopicity. Incorporation of 25% starch into cissus mucilage enhanced extraction of the gum without adverse alteration of the physicochemical properties. PMID:15678725

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

2004-01-01

187

Magnetism.  

National Technical Information Service (NTIS)

This program describes magnets and magnetic materials by pointing out the characteristics of the magnetic field, the molecular arrangement of magnetized and unmagnetized metals, the laws of attraction and repulsion, and the factors that affect the amount ...

1972-01-01

188

Economic analysis of deforestation : the case of the gum Arabic belt in Sudan  

Microsoft Academic Search

Keywords: Gum Arabic; Deforestation; Entry and Exit; Real options Drought; Socio-economic, Oligopoly; Interdependent markets; Stackelberg.<\\/o:p><\\/span><\\/h5>The gum arabic belt in

A. Rahim

2006-01-01

189

Monographs on GRAS (Generally Recognized as Safe) Food Ingredients - Gum Ghatti.  

National Technical Information Service (NTIS)

The monograph summarizes the available scientific literature from 1920 to 1972 related to the 'safety' of gum ghatti as a food ingredient. Chemical information, biological data, and biochemical aspects of gum ghatti are given in a 8 page summary containin...

1972-01-01

190

Evaluation of accelerated stability test conditions for medicated chewing gums.  

PubMed

The overall stability of medicated chewing gums is investigated under different storage conditions. Active substances with different chemical stabilities in solid state are chosen as model drugs. The dosage form is a three layer tablet obtained by direct compression. The gum core contains the active ingredient while the external layers are formulated to prevent gum adhesion to the punches of the tableting machine. Two accelerated test conditions (40C/75% RH and 30C/65% RH) are performed for 6 months. Furthermore, a long-term stability test at room conditions is conducted to verify the predictability of the results obtained from the stress tests. Some drugs are stable in all the conditions tested, but other drugs, generally considered stable in solid dosage forms, have shown relevant stability problems particularly when stress test conditions are applied to this particular semi-solid dosage forms. For less stable drugs, the stress conditions of 40C/75% RH are not always predictable of chewing gum stability at room temperature and may produce false negative; intermediate conditions, 30C/65% RH, are more predictive for this purpose, the results of drug content found after 6 months at intermediate stress conditions and 12 months at room conditions are generally comparable. But the results obtained show that only long-term conditions stability tests gave consistent results. During aging, the semi solid nature of the gum base itself, may also influence the drug delivery rate during chewing and great attention should be given also to the dissolution stability. PMID:22794248

Maggi, Lauretta; Conte, Ubaldo; Nhamias, Alain; Grenier, Pascal; Vergnault, Guy

2012-07-16

191

Studies on some physicochemical properties of leucaena leucocephala bark gum.  

PubMed

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 28C. 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 (28-40C). 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

2010-04-01

192

The effect of chewing gum on tobacco withdrawal.  

PubMed

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 the experimental session and were informed that they would not be allowed to smoke for the remainder of the session. The session consisted of each subject watching a movie, then waiting an additional 30 minutes. Half of the subjects were assigned to a Gum Condition where they were given free access to chewing gum throughout the experimental session; half were assigned to a No-Gum Control. Nicotine withdrawal was assessed immediately following the movie (Time 1) and again 30 minutes later (Time 2). Results from this study indicate that chewing gum reduces craving and helps with withdrawal when a nicotine-dependent person cannot smoke. PMID:9426794

Cohen, L M; Collins, F L; Britt, D M

193

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 28C. 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 (28-40C). 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.

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

2010-01-01

194

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. Sderling; K. K. Mkinen; C.-Y. Chen; W. Loesche; P.-L. Mkinen

1989-01-01

195

Effects of cations on the gelling characteristics of fish mince with added nonionic and ionic gums  

Microsoft Academic Search

The effects of a mixture of added chloride salts (01% NaCl plus 01% KCl plus 01% CaCl2) on the gelling characteristics of blue whiting muscle containing nonionic (locust bean gum, guar gum) or ionic (xanthan gum, carboxymethylcellulose) gums were studied by response surface methodology and factor analysis (principal component analysis). The salts employed did not display any interaction effects altering

M Prez-Mateos; P Montero

2002-01-01

196

Effects of Gum Arabic Concentration and Soy Proteins on the Flow and Viscoelasticity of their Dispersion  

Microsoft Academic Search

The present study analyzed the flow and viscoelasticity behavior of dispersions of 15 to 45% (w\\/v) gum arabic, 1 to 8% (w\\/v) soy proteins, and of gum arabic\\/soy proteins mixtures. Flow of gum arabic dispersions showed Newtonian behavior, while soy protein dispersions and gum arabic\\/soy proteins mixtures presented non-Newtonian behavior (n < 1) of shear thinning type. Viscosity increased by

J. A. Salazar-Montoya; H. A. Jimnez-Avalos; E. G. Ramos-Ramrez

2012-01-01

197

TECHNICAL NOTE: The effect of the green additive guar gum on the properties of magnetorheological fluid  

NASA Astrophysics Data System (ADS)

Magnetorheological (MR) fluid containing guar gum was prepared for the first time by ball-milling the guar gum powder together with silicone oil and carbonyl iron powder. By forming a coating layer over the ground carbonyl iron powder, the guar gum improves the sedimentation stability and thixotropy of the MR fluid effectively.

Fang, Chen; Zhao, Bin Yuan; Chen, LeSheng; Wu, Qing; Liu, Nan; Hu, Ke Ao

2005-02-01

198

Influence of Gum Chewing on Postoperative Bowel Activity after Cesarean Section  

Microsoft Academic Search

Objective: To assess the effects of gum chewing on postoperative bowel function after cesarean section. Material and Methods: Women who underwent cesarean section were randomized to either a gum-chewing group (n = 74) or a non-gum-chewing group (n = 76). The two groups were compared with respect to the return of bowel activity, postoperative analgesic and antiemetic drug requirement and

Hasan Kafali; Elif Gzdemir; Serap Simavli; Yksel Onaran; Esra Keskin

2010-01-01

199

Cigarette Smoking and Nicotine Gum (0, 2 and 4 mg): Effects upon Four Visual Attention Tasks  

Microsoft Academic Search

Sixteen regular smokers, abstinent for 12 h prior to testing, were assessed on a battery of four visual attention tasks: rapid visual information processing (RVIP), letter cancellation, Stroop, and width of attention. Each subject was assessed under four conditions: placebo gum, 2 mg nicotine gum, 4 mg nicotine gum, and cigarette smoking (own brand), with the order of drug administration

A. C. Parrott; D. Craig

1992-01-01

200

Effects of food gums on viscosities of starch suspensions during pasting  

Microsoft Academic Search

Pasting curves of starches in gum (hydrocolloid) solutions at low concentrations (starch 3.6%, gum 0.4%) were produced with a Brookfield viscometer. Gums produced a variety of effects on viscosities of starches during starch pasting (increase or decrease greatly or slightly or no effect). A viscosity increase before the normal starch pasting temperature was detected for normal maize starch in the

Xiaohong Shi; James N. BeMiller

2002-01-01

201

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

202

A Systematic Review of the Efficacy of Gum Chewing for the Amelioration of Postoperative Ileus  

Microsoft Academic Search

Background: Recent trials have shown promising results for the efficacy of gum chewing for the amelioration of postoperative ileus. This finding could have a major clinical impact since gum chewing is relatively harmless and cheap while postoperative ileus has a significant impact on healthcare. Methods: Systematic review and meta-analysis of randomized controlled trials comparing the efficacy of gum chewing after

S. M. M. de Castro; J. W. van den Esschert; N. T. van Heek; S. Dalhuisen; M. J. W. Koelemay; O. R. C. Busch; D. J. Gouma

2008-01-01

203

Prospective of guar gum and its derivatives as controlled drug delivery systems  

Microsoft Academic Search

Guar gum is a non-ionic polysaccharide that is found abundantly in nature and has many properties desirable for drug delivery applications. However, due to its high swelling characteristics in aqueous solution, the use of guar gum as delivery carriers is limited. Guar gum can be modified by derivatization, grafting and network formation to improve its property profile for a wide

M. Prabaharan

2011-01-01

204

Evaluation of the Safety of Tara Gum as a Food Ingredient: A Review of the Literature  

Microsoft Academic Search

Tara gum is a potential replacement for locust bean gum for use as a formulation aid, stabilizer, and thickener for food applications. In addition to biochemical and digestibility data, studies assessing the toxicity of tara gum are reviewed. The latter includes three 90-day feeding studies, two in rats and one in dogs; two 2-year feeding studies in rats and one

Joseph F. Borzelleca; Bert N. Ladu; Frederic R. Senti; John L. Egle

1993-01-01

205

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; Pr, Valria Dal; de Oliveira, Dbora; Oliveira, J Vladimir; Castilhos, Fernanda; Treichel, Helen; Mazutti, Marcio A

2011-05-07

206

A "SOLUBLE SPECIFIC SUBSTANCE" DERIVED FROM GUM ARABIC  

PubMed Central

1. By partial acid hydrolysis a specific carbohydrate may be isolated from gum arabic (gum acacia). This carbohydrate is comparable in its precipitating activity for Type II (and Type III) antipneumococcus serum with the bacterial soluble specific substances themselves. 2. On hydrolysis this fraction yields galactose and two or more complex sugar acids, one of which appears to be a disaccharide add comparable with those isolated from the specific polysaccharides of the Type III pneumococcus and the Type A Friedlnder bacillus. 3. The significance of these findings is discussed.

Heidelberger, Michael; Avery, Oswald T.; Goebel, Walther F.

1929-01-01

207

On the application of Supplement 1 to the GUM to non-linear problems  

NASA Astrophysics Data System (ADS)

Supplement 1 to the GUM (GUM-S1) produces an arbitrarily large sample from a probability distribution for the measurand which is used for the calculation of an estimate and its associated uncertainty. In the presence of Gaussian observations on one or several input quantities this distribution is equivalent to the Bayesian posterior obtained for a particular choice of a non-informative prior. Recently, a reference prior under partial information was proposed as an alternative non-informative prior in this context. Since for non-linear problems different results are obtained with this prior than by application of GUM-S1, the question arises whether GUM-S1 should actually be recommended for non-linear problems. We address this question by comparing the properties of the GUM-S1 distribution and the posterior distribution obtained by the proposed alternative prior. The comparison is supplemented by also considering a hybrid prior which assigns a constant prior for the measurand. We specify the conditions when the same results are reached. While the GUM-S1 distribution is always proper, we show that the proposed reference prior under partial information and the hybrid prior can fail to yield a proper posterior. On the basis of this (most important) criterion we can already recommend application of GUM-S1. Finally, we show that the prior underlying GUM-S1 can be derived as a (conditional) data-translated likelihood prior that exploits the symmetry and invariance of the considered likelihood function.

Bodnar, O.; Wbbeler, G.; Elster, C.

2011-10-01

208

Effect of arabic gum and xanthan gum on the stability of pesticide in water emulsion.  

PubMed

The effect of arabic gum (AG) and xanthan gum (XG) on the physicochemical properties of 2% pesticide avermyctin in water emulsions was systematically investigated by measuring creaming stability, droplet size, zeta potential, and rheology. Addition of AG and XG had significant influence on the physicochemical properties of emulsions. Emulsions showed high stability throughout the storage time in the AG concentration range of 0-0.14%. In contrast, addition of XG induced the apparent creaming of emulsion as the XG concentration increased from 0.011 to 0.15%, which might be well explained by the depletion flocculation of droplets. The droplet diameter increased progressively with increasing AG concentration; however, it sharply grew initially with XG concentration and reached a maximum, followed by a gradual decrease. Zeta potential increased gradually as AG concentration was lower than 0.081%, followed by a slight decrease, whereas it reduced dramatically as XG concentration increased from 0.011 to 0.040% and then remained almost unchanged. In the AG concentration range of 0-0.14%, the emulsion exhibited typical Newtonian flow behavior and the viscosity decreased a little. The XG emulsion exhibited Newtonian flow behavior at low XG concentrations (?0.019%), whereas, non-Newtonian flow behavior was displayed at relatively high XG concentrations (>0.019%), wherein viscosity value and yield value increased gradually as XG concentration increased. In addition, the curves of shear stress versus shear rate for XG emulsion and solution were well fitted by a power law model and the Herschel-Bulkley model; the Herschel-Bulkley model fitted much better. The present study would provide useful information for the reasonable application of AG and XG in making stable pesticide emulsion. PMID:21226518

Zhang, Xiaoguang; Liu, Jiexiang

2011-01-12

209

A non-ionic water-soluble seed gum from Ipomoea campanulata.  

PubMed

A non-ionic water-soluble galactomannan, having galactose and mannose in 2:3 molar ratio was isolated from endosperm of the seeds of Ipomoea campanulata. The seed gum was found to have linear chain of beta (1-->4) linked mannopyranosyl units with D-galactose side chains attached through alpha (1-->6) linkage to the main chain. This structure is similar to many commercial gums like Guar, Carob and Locust bean gum. Various physical properties of the gum were studied in order to explore the possibility of commercial exploitation of the seed gum. PMID:12628393

Singh, V; Pandey, M; Srivastava, A; Sethi, R

2003-02-01

210

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

211

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

PubMed

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 gum, or 4-mg nicotine gum. They were instructed to smoke as usual throughout the study. Mean plasma nicotine concentration was 29.5 ng/ml with the placebo gum, 30.9 ng/ml with the 2-mg gum, and 40.7 ng/ml with the 4-mg gum. Peak carbon monoxide level was lower with nicotine gum than with placebo gum. Data indicate self-regulation of blood nicotine levels. The subjects appear to have compensated almost completely for the increased intake of nicotine from the 2-mg nicotine gum by decreasing the inhalation of tobacco smoke. Nicotine compensation provided by the 4-mg nicotine gum is only partial. PMID:6705447

Ebert, R V; McNabb, M E; Snow, S L

1984-04-01

212

Effects of chewing gum on the stress and work of university students.  

PubMed

Recent research has indicated that chewing gum can relieve perceptions of stress in an occupational sample (Smith, 2009). In the present study, 72 students completed 2 weeks of either chewing gum or refraining from chewing gum. They completed scales measuring perceived stress, anxiety, depression, and single item measures of work levels and tiredness. These were completed both pre- and post-treatment. Perceived stress decreased as a function of the amount of gum chewed. The chewing gum condition was also associated with a decrease in not getting enough academic work done. There were no significant effects of chewing gum on mental health outcomes. These results confirm some of findings from previous studies of chewing gum and stress in other samples. PMID:22402304

Smith, Andrew P; Woods, Martin

2012-03-05

213

Oxygen transfer and uptake rates during xanthan gum production  

Microsoft Academic Search

Oxygen uptake rate and oxygen mass transfer rate have been studied during xanthan gum production process in stirred tank bioreactor. Empirical equations for the oxygen mass transfer coefficient have been obtained taking into account several variables such as air flow rate, stirrer speed and apparent viscosity. Oxygen uptake rate evolution in the course fermentation has been measured, obtaining an equation

F Garc??a-Ochoa; E. Gmez Castro; V. E Santos

2000-01-01

214

Study of Mutagenic Effects of Guar Gum (71-16).  

National Technical Information Service (NTIS)

The study includes results of three mutagenic assay procedures. The host-mediated assay of guar gum (71-16) did not produce any measureable mutagenic response or alteration in the recombination frequency for Saccharomyces cerevisiae in either the host-med...

G. W. Newell W. A. Maxwell

1972-01-01

215

21 CFR 172.615 - Chewing gum base.  

Code of Federal Regulations, 2013 CFR

...concentrated latices) of vegetable origin Family...The residue is hydrogenated and further treated...a maximum oil content of 0.5...ester of partially hydrogenated gum or wood rosin...Glycerol ester of tall oil rosin Having...rosin, partially hydrogenated Having an...

2013-04-01

216

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

217

Xanthan gum production from waste sugar beet pulp  

Microsoft Academic Search

The feasibility of using waste sugar beet pulp (WSBP) as a supplemental substrate for xanthan gum production from Xanthomonas campestris was investigated. For the range of incubation periods and contact times investigated (1 to 5 days), there were no differences in the mean WSBP degradation. The mean WSBP degradation was significantly greater for incubation temperatures of 28C as compared to

Seong D Yoo; Sarah W Harcum

1999-01-01

218

PHENOLIC ACIDS, LIPIDS AND PROTEINS IN CORN FIBER GUM  

Technology Transfer Automated Retrieval System (TEKTRAN)

An arabinoxylan (hemicellulose B), termed "Corn fiber gum" (CFG), is obtained by the alkaline extraction of corn kernel pericarp and/or endosperm fractions of corn fiber (1). Two classes of phytochemicals, hydroxycinnamic acids (p-coumaric and ferulic) and lipids were released, when CFG was hydroly...

219

Method for inhibiting gum formation in liquid hydrocarbon mediums  

SciTech Connect

This patent describes a method of inhibiting the formation of gum and sediment in a liquid hydrocarbonaceous medium. It comprises: adding to the medium an inhibiting amount of an alkyl 1,2-dihydroquinoline or polymerized alkyl 1,2-dihydroquinoline.

Reid, D.K.

1990-07-17

220

Gum and deposit formation from jet turbine and diesel fuels  

SciTech Connect

The rates of oxidation and soluble gum formation in both pure hydrocarbons and mixed hydrocarbon fuels are investigated. A rate equation in terms of rate constants for initiation, propagation, and termination is discussed. A theory based on the coupling of fuels and their primary oxidation products to form products of higher molecular weight is presented.

Mayo, F.R.; Lan, B.Y.

1983-01-01

221

Contribution of lipids, phenolic acids, and protein rich components to emulsifying properties of corn fiber gum and acacia gum  

Technology Transfer Automated Retrieval System (TEKTRAN)

Corn fiber gum (CFG) is an arabinoxylan enriched fraction obtained by the extraction of corn bran/fiber using a proprietary alkaline hydrogen peroxide process. When purified CFG prepared by this process was hydrolyzed with concentrated base (1.5 N methanolic KOH at 70 C for one hour) considerable ...

222

Effect of sol-gel transition on shear-induced drop deformation in aqueous mixtures of gellan and kappa-carrageenan.  

PubMed

In this work, we present an experimental methodology to investigate the dynamics under shear flow of a drop that is gelling as a consequence of a temperature quench. The experiments were carried out on the system water/gellan/kappa-carrageenan in the biphasic region of the phase diagram, the gellan-rich phase being used as the dispersed phase. Gelation was brought about by lowering the temperature during flow after steady state drop deformation had been reached. Simple shear flow was applied by using a parallel plate apparatus equipped with optical microscopy and image analysis, which made it possible to monitor drop shape evolution before, during, and after gelation. The onset of gelation trapped drop deformation, thus producing anisotropic particles. The fingerprint of gelation was the simultaneous tumbling of the drops, which rotated as rigid ellipsoids under the action of shear flow. Interfacial tension between the two equilibrium phases was determined at different times during the temperature quench by analyzing drop retraction upon cessation of flow. Up to gelation, no significant change was observed in the measured values. PMID:15571707

Simeone, M; Tassieri, M; Sibillo, V; Guido, S

2005-01-15

223

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

224

The effect of chewing gum's flavor on salivary flow rate and pH  

PubMed Central

Background: Chewing sugar-free gums is a convenient way to increase salivary flow. Salivary flow increases in response to both gustatory (taste) and mechanical (chewing) stimuli, and chewing gum can provide both of these stimuli. The aim of this study was to compare the effect of five different flavors of sugar-free chewing gum on the salivary flow rate (SFR) and pH. Materials and Methods: Fifteen dental students volunteered at the same time on six consecutive days, to collect one minute unstimulated saliva. After five minutes, while some volunteers continued to collect only unstimulated saliva, the others asked to start chewing one of the five flavored gums randomly. The flavors were spearmint, cinnamon, watermelon, strawberry, and apple. The whole saliva was collected over time periods of 0 1, 1 3, and 3 6 minutes, and the SFR and pH were also measured. The data were subjected to pair t-test, repeated-measures analysis of variance, and Duncan tests. Results: Compared to the unstimulated rate, all five different flavored gums significantly increased the SFR within six minutes. Although the flow rate peaked during the first minute of stimulation with all five products, it reduced gradually, but still remained above the unstimulated saliva, after six minutes. In the first minute, the strawberry-flavored gums showed the highest weight, yet, it only induced a significantly higher SFR compared to the cinnamon-flavored gums. During one to three minutes, strawberry and apple-flavored gums showed significantly higher SFR, respectively, compared to cinnamon-flavored gums. There were no significant differences in the flow rates elicited by each flavored gum through the three-to-six minute interval, although the spearmint-flavored gums induced slightly higher SFR. Only the spearmint and cinnamon-flavored gum significantly increased the salivary pH. Conclusion: Gum flavor can affect the SFR and special flavors may be advised for different individuals according to their oral conditions.

Karami-Nogourani, Maryam; Kowsari-Isfahan, Raha; Hosseini-Beheshti, Mozhgan

2011-01-01

225

Property of cellular silicone from high-vinyl silicone gums as a function of porosity (referenced to SE54 gum). [Density, porosity, deflection, compression set  

SciTech Connect

We have established the load-deflection properties of cushions from the high methylvinylsiloxane (MVS) content gums, L97KVB-0.7, MN97KVB-0.7, and L60VB-0.7, as a function of cushion porosity. These properties are referenced to the properties of cushions from General Electric's (GE) SE54 gum which has considerably less MVS. The higher MVS gums produce considerably stiffer cushions. We have also evaluated the confined compression set of these various porosity cushions. There is no pattern for set as a function of porosity. Set is reduced at the higher MVS contents. We have established the densities of the cured solid elastomers (3219) from the four silicone gums. We have also calculated a linear relationship between porosity of the cushions and the wt % of urea temporary filler in the molding compound for the 97-type gums and L60 gum. L97KVB-0.7 and MN97KVB gums produce cushions with similar but not exactly the same load-deflections and sets, and are alike in their correlations of porosity with urea loading. L60VB-0.7 produces a softer cushion and probably has less set than the 97-type gums at 0.7% MVS. 13 figures, 36 tables.

Cady, W.E.; Jessop, E.S.; McKinley, B.M.

1982-08-20

226

Absence of coreshine in the Gum/Vela region  

NASA Astrophysics Data System (ADS)

Context. We recently discovered mid-infrared light scattering by micron-size grains deeply buried in dark clouds. We have named this coreshine. We also showed that this effect is widespread across the Galaxy except in the Gum/Vela region, the only region among those we explored without any trace of coreshine. Aims: We aim to check whether the Gum/Vela situation is a chance effect or if coreshine is really absent from the region. Methods: We explored the entire available Spitzer/InfraRed Red Array Camera (IRAC) archive centered on the Gum/Vela region in search of the coreshine effect. Results: Out of 24 validated objects (of a total of 32), we found three cases of coreshine and three possible other cases, while we detect nine cases of non-coreshine emission (bright rimmed clouds - BRC - or polycyclic aromatic hydrocarbon - PAH - emission). This is markedly different from our previous galactic-wide survey with a ratio of 7-8 coreshine cases per PAH case. In Gum/Vela, a majority of the clouds with protostars or young stellar objects do not show a coreshine effect, while in the galactic-wide survey, 75% of the protostellar clouds do. Conclusions: The rare occurence of coreshine, outnumbered by PAH and BRC cases, together with a large number of protostars, let us conclude that the Gum Nebula is a supernova remnant (SNR), and that the blast wave has both reset the grain size distribution and induced the formation of several protostars. The absence of coreshine in the vicinity of several of the Class I objects also implies that the growth time for grains to efficiently scatter mid-infrared radiation exceeds the Class I life duration, which is typically 2 105 years, and it also implies that the blast wave has reached these clouds only recently despite the age of the Gum region (over 1.5 My). This is consistent with their large distance from the center of the SNR. Appendices B and C are available in electronic form at http://www.aanda.org

Pagani, L.; Lefvre, C.; Bacmann, A.; Steinacker, J.

2012-05-01

227

X-ray diffraction, IR spectroscopy and thermal characterization of partially hydrolyzed guar gum.  

PubMed

Guar gum was hydrolyzed using cellulase from Aspergillus niger at 5.6 pH and 50C temperature. Hydrolyzed guar gum sample was characterized using Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, dilute solution viscometry and rotational viscometry. Viscometry analysis of native guar gum showed a molecular weight of 889742.06, whereas, after enzymatic hydrolysis, the resultant product had a molecular weight of 7936.5. IR spectral analysis suggests that after enzymatic hydrolysis of guar gum there was no major transformation of functional group. Thermal analysis revealed no major change in thermal behavior of hydrolyzed guar gum. It was shown that partial hydrolysis of guar gum could be achieved by inexpensive and food grade cellulase (Aspergillus niger) having commercial importance and utilization as a functional soluble dietary fiber for food industry. PMID:22409871

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

2012-03-03

228

Moisture Adsorption Isotherms and Glass Transition Temperature of Xanthan Gum  

Microsoft Academic Search

The moisture adsorption isotherms of the xanthan gum were determined at 3070C over water activity ranging from 0.11 to 0.94. The moisture adsorption isotherms revealed that the equilibrium moisture content increased with water activity. Increased temperature, in general, resulted in decreased equilibrium moisture content. However, in some cases equilibrium moisture content values increased with temperature. Selected sorption models were tested

Santanu Basu; A. S. Mujumdar

2007-01-01

229

Evaluation of the flow properties of xanthan gum solution  

SciTech Connect

In this study, the solution properties of two forms of xanthan gum, a powder and a broth, which are commercially available were evaluated. As previous studies have shown, the solutions prepared from the broth do exhibit better injectivity properties. However, this investigation also shows that other properties of these solutions are not equivalent. In its natural state, xanthane gum exists as a multistranded helix. This ordered confirmation can be destroyed and in a denatured state, the xanthan gum exhibits a more random configuration and consequently higher viscosity. One of the major conclusions of this study is that the xanthan powder is partially denatured when compared to the xanthan molecules which exist in the broth. This denaturing may occur during the drying process in which the xanthan solids are removed from the broth. Solutions prepared from the broth in the absence of the added salt show a transition in the viscosity-temperature relationship at approximately 40 to 50/sup 0/C. This is consistent with the behavior of native xanthan gum solutions. At approximately 50/sup 0/C, the molecules in solution go into a more random state and consequently, an abrupt rise in the viscosity is observed. However, solutions prepared from the polymer powder do not show any evidence of such a transition. The solutions prepared from the broth can be thermally denatured, and this denaturing results in viscosities which are equivalent to the viscosities realized with the powdered polymer. Before denaturing, the broth solution showed a lower viscosity. Further, intrinsic viscosity measurements indicate that the hydrodynamic volume of the polymer solutions prepared from the borth are smaller than the hydrodynamic volumes of solutions prepared from the powder.

Duda, J.L.; Klaus, E.E.; Leung, W.C.

1981-02-01

230

Correlating the fineness and residual gum content of degummed hemp fibres  

Microsoft Academic Search

It is well known residual gum exists in degummed or retted hemp fibres. Gum removal results in improvement in fibre fineness\\u000a and the properties of the resultant hemp yarns. However, it is not known what correlation if any exists between the residual\\u000a gum content in retted hemp fibres and the fibre fineness, described in terms of fibre width in this

Rafael Beltran; Christopher J. Hurren; Akif Kaynak; Xungai Wang

2002-01-01

231

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

232

Zeta potential and drop growth of oil in water emulsions stabilized with mesquite gum  

Microsoft Academic Search

The influence of the nature of the oil phase on the zeta potential and the time course evolution of mean droplet-size of emulsions stabilized with mesquite gum have been investigated. Mesquite gum-stabilized emulsions of d-limonene, n-decane, n-dodecane, n-tetradecane n-hexadecane, and orange oil were prepared in the range of 922% w\\/w mesquite gum concentrations to investigate the emulsion stability by analyzing

J. I. Acedo-Carrillo; A. Rosas-Durazo; R. Herrera-Urbina; M. Rinaudo; F. M. Goycoolea; M. A. Valdez

2006-01-01

233

Chewing gum, occupational stress, work performance and wellbeing. An intervention study.  

PubMed

An intervention study was carried out to examine the effects of chewing gum on occupational stress and related outcomes. 101 volunteers from Cardiff University completed the study. The results showed that chewing gum reduced stress (both at work and outside work), reduced fatigue, reduced anxiety and depression and led to a more positive mood. Chewing gum was also associated with perceptions of better performance (both at work and outside). PMID:22390954

Smith, Andrew P; Chaplin, Katherine; Wadsworth, Emma

2012-03-03

234

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

235

Meta-Analytical Review of the Efficacy of Nicotine Chewing Gum in Smoking Treatment Programs  

Microsoft Academic Search

The research on the effectiveness of nicotine gum as a treatment for smoking was reviewed through a meta-analysis of 33 studies. The differential effectiveness of experimental (nicotine gum) versus control (placebo and no gum) groups at both short- and long-term follow-up was indexed as d, the mean effect size. These effect sizes were contrasted within each brief and intensive treatments.

Antonio Cepeda-Benito

1993-01-01

236

Quantitative analysis of ?-pinene and ?-myrcene in mastic gum oil using FT-Raman spectroscopy  

Microsoft Academic Search

?-Pinene and ?-myrcene are compounds that are contained in mastic gum in high concentrations. The ?-myrcene percentage determines the marketability of mastic gums. The chemical composition of mastic gum oil of a representative resin quality was evaluated by gas chromatographymass spectrometry (GCMS) technique. FT-Raman spectroscopy, based on band intensity measurements, was used for the determination of ?-pinene and ?-myrcene content

D. Daferera; C. Pappas; P. A. Tarantilis; M. Polissiou

2002-01-01

237

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

238

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

239

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.

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

2011-01-01

240

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

PubMed

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 gum + placebo patch (gum only active), placebo gum + active patch (patch active) and placebo gum + placebo patch (double placebo). This "double placebo" design controls sensory, psychological and ritual variables associated with each drug form. Withdrawal symptoms were rated four times daily for 3 days in each condition. Total baseline (smoking) withdrawal scores using visual analogue scales (VAS) averaged 101.1. During cessation, total withdrawal increased to 187.0 for the double placebo condition, 142.2 for the active gum/placebo patch treatment and 128.3 for the active patch/placebo gum treatment. The double active condition equalled smoking with score 99.2. All pairwise comparisons were significant (P < 0.001) except between the two single active conditions and between smoking versus the double active condition. Significant time-of-day effects by treatment on withdrawal were observed for the double placebo condition (P < 0.05) with less withdrawal in the morning. The findings suggest: 1) combining nicotine gum with transdermal nicotine may be superior to either treatment alone, 2) more symptoms may be nicotine specific (relieved by replacement) than previously thought. PMID:7870963

Fagerstrm, K O; Schneider, N G; Lunell, E

1993-01-01

241

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

242

Effect of masticating chewing gum on postural stability during upright standing.  

PubMed

The purpose of this study was to investigate the effect of masticating chewing gum on postural stability during upright standing. To address this issue, 12 healthy subjects performed quiet standing on a force platform for the posturography study. The subjects were instructed to stand as stable as possible on the force platform in order to record the trajectory of the center-of-pressure (COP). After measuring the postural sway in the initial condition (pre-condition), the subjects were asked to stand while masticating chewing gum (gum-condition). Following the gum-condition, quiet standing without mastication was evaluated (post-condition) to ensure the effect of masticating chewing gum on postural stability. The trajectory and velocity of the COP were analyzed for each condition. We found that the postural stability tended to enhance during mastication of chewing gum. The rectangle area of the COP trajectory significantly diminished in the gum-condition and significantly enlarged in the post-condition. A similar effect was observed in the maximum velocity and standard deviation (SD) of the fore-aft amplitude of the COP trajectory. The values were significantly smaller in the gum-condition compared to those in the post-condition. These findings suggest that mastication of chewing gum affects the postural control by enhancing the postural stability during upright standing. PMID:20959136

Kushiro, Keisuke; Goto, Fumiyuki

2010-10-17

243

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 2.6710-2 min-1.

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

2012-08-01

244

In-vitro evaluation of khaya and albizia gums as compression coatings for drug targeting to the colon.  

PubMed

Khaya and albizia gums were evaluated as compression coatings for target drug delivery to the colon using indometacin (a water insoluble drug) and paracetamol (a water soluble drug) as model drugs. The core tablets were compression-coated with 300 and 400 mg of 100% khaya gum, 100% albizia gum and a mixture of khaya and albizia gum (1:1). Drug release studies were carried out in 0.1(M) HCl (pH 1.2) for 2 h, Sorensen's buffer (pH 7.4) for 3 h and then in phosphate-buffered saline (pH 6.8) or in simulated colonic fluid for the rest of the experiment to mimic the physiological conditions from the mouth to colon. The results indicated that khaya and albizia gums were capable of protecting the core tablet in the physiological environment of the stomach and small intestine, with albizia gum showing greater ability than khaya gum. The release from tablets coated with the mixture of khaya and albizia gums was midway between the two individual gums, indicating that there was no interaction between the gums. Studies carried out using rat caecal matter in phosphate-buffered saline at pH 6.8 (simulated colonic fluid) showed that the gums were susceptible to degradation by the colonic bacterial enzymes, leading to release of the drug. The results demonstrate that khaya gum and albizia gum have potential for drug targeting to the colon. PMID:15720778

Odeku, Oluwatoyin A; Fell, John T

2005-02-01

245

Three clinical trials comparing xylitol- and sorbitol-containing chewing gums for their effect on supragingival plaque accumulation.  

PubMed

Studies have evaluated the effects of xylitol when administered in chewing gum, as a dietary substitute for sugar, in dentifrice and in mouthrinse. Three clinical trials were conducted to further investigate chewing gums containing xylitol or xylitol/sorbitol mixtures for their ability to reduce plaque accumulation when compared to a sorbitol containing gum. These studies all had two phases; supragingival prophylaxis with an assessment of plaque accumulation to be used for balanced assignment for the second phase, which assessed plaque regrowth following a second supragingival prophylaxis and various chewing gum regimens. In the first trial of xylitol/sorbitol versus sorbitol gum only, the combination gum had a significantly greater reduction in plaque growth. In the second trial, different regimens of chewing gums with xylitol/sorbitol and sorbitol alone were compared. The combined average of the plaque regrowth scores for the subjects chewing the xylitol/sorbitol gum was significantly better than that for the sorbitol gum alone. The final trial evaluated two regimens in two forms (stick and pellet) of a xylitol gum versus a sorbitol gum. Both xylitol-containing gum forms were statistically superior to the sorbitol gum in retarding plaque regrowth. PMID:8602901

Cronin, M; Gordon, J; Reardon, R; Balbo, F

1994-01-01

246

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

PubMed

Sugarless chewing gum is a frequently used stimulant to collect saliva samples for hormone analyses. This study tested the effect of sugarless chewing gum on cortisol, testosterone, and progesterone concentrations measured in saliva samples collected from 8 individuals at different times of the day (morning, evening) and under different collection conditions (gum, no gum) as well as in a saliva pool and water, either untreated or treated with chewing gum. Sugarless chewing gum raised all progesterone concentrations by 20 to 40pg/mL, corresponding to a twofold increase, relative to no-gum controls and attenuated salivary testosterone and cortisol concentrations. It is recommended that the use of sugarless chewing gum as a stimulant should be avoided with saliva samples. PMID:23220228

Schultheiss, Oliver C

2012-12-06

247

Process for the selective hydrogenation of gasolines comprising both gum-generating compounds and undesirable sulfur compounds  

SciTech Connect

Unsaturated gasolines of both high mercaptan or hydrogen sulfide content and high gum-generator content are hydrogenated first over a palladium catalyst and then over a nickel catalyst. Resultant unsaturated gasolines are sweet and have low gum generator content.

Cosyns, J.; Derrien, M.

1980-06-17

248

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

249

Characterisation of natural polysaccharides (plant gums) used as binding media for artistic and historic works by capillary zone electrophoresis.  

PubMed

The monosaccharide constituents of plant gums were separated by capillary electrophoresis at pH 12.1 and detected with indirect UV absorbance. The plant gums investigated were gum arabic, gum acacia, gum tragacanth, cherry gum and locust bean gum (carob gum). The monosaccharides obtained after hydrolysis with 2M trifluoroacetic acid and lyophilisation of the hydrolysate were arabinose, galactose, mannose, rhamnose, xylose, fucose, and glucose, and the two sugar acids galacturonic and glucuronic acid, in accordance with the literature. They were separated in a background electrolyte consisting of NaOH to adjust the pH, 20 mM 2,6-pyridinedicarboxylic acid as chromophore for detection and 0.5 mM cetyltrimethylammonium bromide as additive to reverse the electroosmotic flow. Based on their electropherograms, the plant gums could be identified by their typical composition (depicted in a decision scheme) as follows: a peak of glucuronic acid, together with that of rhamnose, is indicative for gum arabic. Peaks of galacturonic acid and fucose point to gum tragacanth. Locust bean gum shows a major peak for mannose (with the concomitant galactose peak in ratio 4-1), whereas a glucuronic acid and a mannose peak together with a prominent arabinose peak indicates cherry gum. The method was applied to identify the plant gums in samples like watercolours and in several paint layers like gum tempera or those with egg white or drying oils as additives. Artificial aging experiments of thin layers of gum arabic on paper or glass carried out with UV-A radiation (366 nm) did not result in changes of the saccharide patterns, in contrast to the simultaneously conducted aging of a drying oil layer. PMID:15988990

Grssl, Michael; Harrison, Sabine; Kaml, Isabella; Kenndler, Ernst

2005-06-01

250

Genome Sequence of the Welan Gum-Producing Strain Sphingomonas sp. ATCC 31555  

PubMed Central

Sphingomonas sp. strain ATCC 31555 can produce an anionic heteropolysaccharide, welan gum, which shows excellent stability and viscosity retention even at high temperatures. Here we present a 4.0-Mb assembly of its genome sequence. We have annotated 10 coding sequences (CDSs) responsible for the welan gum biosynthesis and 55 CDSs related to monosaccharide metabolism.

Wang, Xiaoyu; Tao, Fei; Gai, Zhonghui; Tang, Hongzhi

2012-01-01

251

Cell free xanthan gum production using continuous recycled packed fibrous-bed bioreactor-membrane  

Microsoft Academic Search

Although the xanthan gum has been produced as a commercial commodity, the biomass isolation and its recovery are still challenging. This study revealed the xanthan gum production by fermentation of Xanthomonas campestris DSMZ using glucose as a carbon source in an immobilised batch and a continuous recycled packed fibrous-bed bioreactor-membrane (CRPBFBM). The pure cotton fibre was used to immobilise the

252

Synthesis of oxidized guar gum by dry method and its application in reactive dye printing  

Microsoft Academic Search

The aim of this study was to prepare oxidized guar gum with a simple dry method, basing on guar gum, hydrogen peroxide and a small amount of solvent. To obtain a product with suitable viscosity for reactive dye printing, the effects of various factors such as the amount of oxidant and solvent, reaction temperature and time were studied with respect

Honghong Gong; Mingzhu Liu; Bing Zhang; Dapeng Cui; Chunmei Gao; Boli Ni; Jiucun Chen

2011-01-01

253

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

254

In vitro studies on guar gum based formulation for the colon targeted delivery of Sennosides  

Microsoft Academic Search

PURPOSE: The objective of the present study is to develop colon targeted drug delivery sys- tems for sennosides using guar gum as a carrier. METHODS: Matrix tablets containing various pro- portions of guar gum were prepared by wet granula- tion technique using starch paste as a binder. The tablets were evaluated for content uniformity and in vitro drug release study

Munira Momin; K. Pundarikakshudu

255

The effects of sugar-free chewing gums on dental plaque regrowth: A comparative study  

Microsoft Academic Search

Sugar-free chewing gum has been claimed to be a useful means of reducing dental plaque accumulation. The incorporation of additives, such as enzymes, abrasives and divalent metal ions, into gum formulations might improve their antiplaque activity, particularly at the buccal and lingual surfaces of the teeth.

Giuseppe Pizzo; Maria Ester Licata; Monica La Cara; Ignazio Pizzo; Rosario Guiglia; Dario Melilli

2007-01-01

256

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 2550% edible starches of sweet cassava, sweet potato, and maize. Dry samples were milled and sieved through a 250-m 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

257

Gum katira a cheap gelling agent for plant tissue culture media  

Microsoft Academic Search

Gum katira, an insoluble gum derived from the bark of Cochlospermum religiosum, has been successfully used as a gelling agent in tissue culture media for in vitro shoot formation and rooting in Syzygium cuminii and somatic embryogenesis in Albizzia lebbeck. The epicotyl segments, excised from in vitro grown seedlings of S. cuminii, developed shoots when cultured on MS medium (Murashige

Neeru Jain; Shashi B. Babbar

2002-01-01

258

Stability of cumin oleoresin microencapsulated in different combination of gum arabic, maltodextrin and modified starch  

Microsoft Academic Search

Microencapsulations of cumin oleoresin by spray drying using gum arabic, maltodextrin, and modified starch (HiCap 100) and their ternary blends as wall materials were studied for its encapsulation efficiency and stability under storage. The microcapsules were evaluated for the content and stability of volatiles, and total cuminaldehyde, ?-terpinene and p-cymene content for six weeks. Gum arabic offered greater protection than

Dattanand Kanakdande; Rajesh Bhosale; Rekha S. Singhal

2007-01-01

259

Gum Spots Caused by Cambium Miners in Black Cherry in West Virginia.  

National Technical Information Service (NTIS)

Six types of gum spots in black cherry, Prunus serotina, were associated with parenchyma flecks caused by the cambium miner Phytobia pruni. The number of parenchyma flecks and associated gum spots increased with the height of the tree. Four percent of the...

C. O. Rexrode J. E. Baumgras

1980-01-01

260

Whole Saliva Flow Rate and Proteolytic Activity Induced by an Enzyme-Containing Chewing Gum.  

National Technical Information Service (NTIS)

To learn the effect of enzyme chewing gum on flow rate and proteolytic enzyme content of the oral fluid, 1,980 whole saliva samples were collected from 120 healthy young adult males. The test gum produced a rate of flow of 1.442 ml./min., this mean not di...

I. L. Shannon V. A. Segreto

1967-01-01

261

Laser-induced-fluorescence detection of gums in jet fuels. Final report, Jul 90-May 92  

SciTech Connect

The current method (ASTM D381) of determining the concentration of gums in jet fuels is a lengthy procedure requiring a large sample size. Because gum formation is believed to be an important step in the formation of deposits in fuel systems used in jet aircraft, a non-intrusive method of performing spatially resolved measurements of gum concentration in high temperature flow systems is a desired research tool. The present study was conducted to determine the feasibility of using laser-induced fluorescence (LIF) to monitor gum concentration in jet fuel. The study revealed several effects, such as aging and the interference of other fluoroshores with gum fluorescence, which require further investigation before LIF is to be considered a quantitative technique for measuring gums in jet fuels. However, this study showed that the formation of gums in jet fuels is detectable by LIF. The results show that gum formation in some fuels correlates strongly with LIF while for other fuels the results are ambiguous.

Naegeli, D.W.; Hill, R.H.

1992-05-01

262

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. Fagerstrm; N. G. Schneider; E. Lunell

1993-01-01

263

77 FR 34997 - Xanthan Gum From Austria and China; Institution of Antidumping Duty Investigations and Scheduling...  

Federal Register 2010, 2011, 2012, 2013

...Investigation Nos. 731-TA-1202-1203 (Preliminary)] Xanthan Gum From Austria and China; Institution of Antidumping Duty Investigations...by reason of imports from Austria and/or China of xanthan gum, provided for in subheading 3913.90.20 of the...

2012-06-12

264

Combined Use of Nicotine Patch and Gum in Smoking Cessation: A Placebo-Controlled Clinical Trial  

Microsoft Academic Search

Background. Smoking is considered as an addiction to nicotine for most subjects consuming 10 cigarettes or more per day. Hence, nicotine replacement therapy by way of gum, patch, or spray has been advocated. The rationale of this study is to evaluate the possible beneficial effects of adding nicotine gum to the routine of subjects using the nicotine patch. The effect

M. Kornitzer; M. Boutsen; M. Dramaix; J. Thijs; G. Gustavsson

1995-01-01

265

RHEOLOGICAL STUDY OF XANTHAN AND LOCUST BEAN GUM INTERACTION IN DILUTE SOLUTION: EFFECT OF SALT  

Technology Transfer Automated Retrieval System (TEKTRAN)

An oscillatory capillary rheometer was used to investigate the effects of NaCl, KCl, and CaCl2 on visco-elastic properties of xanthan and locust bean gum (LBG) blends in dilute solution. Gums were evaluated for intrinsic viscosity and elastic component. Molecular conformation of the xanthan-LBG comp...

266

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

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

2008-01-01

267

CORN FIBER: A POTENTIAL GUM ARABIC REPLACER FOR BEVERAGE FLAVOR EMULSIFICATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

The U.S. food industry needs a domestically produced food gum with a dependable supply and consistent quality, which can be used for preparing oil-in-water emulsions, such as citrus oil emulsions for beverages. Corn Fiber Gum (CFG) is an arabinoxylan (hemicellulose) extracted from the corn kernel p...

268

Evaluation of alternatives to guar gum as tackifiers for hydromulch and as clumping agents for biodegradable cat litter  

Technology Transfer Automated Retrieval System (TEKTRAN)

Guar gum is currently the principal gum used as a tackifier for hydromulch used in erosion control, and as a clumping agent in biodegradable cat litters. Due to recent severe price increases for guar gum, cheaper alternatives are being investigated. We examined several alternatives, including xanth...

269

The effect of chewing gum flavor on the negative affect associated with tobacco abstinence among dependent cigarette smokers.  

PubMed

Many smokers relapse during cessation attempts due to increases in negative affect. Previous research has shown that chewing confectionary chewing gum appears to lessen the severity of acute nicotine withdrawal symptoms and help individuals who are trying to reduce smoking in part due to the flavor of the gum chewed. The current study compared the effects of three flavored gums to a No Gum Control during 48-hour cessation periods for young dependent smokers. Forty-nine smokers participated in three experimental conditions (peppermint, vanilla, and baked apple cardamom flavored gum) as well as a No Gum Control across four weeks while abstaining from smoking for 48-hours each week. Compared to the No Gum Control, participants in the Gum conditions reported lower levels of anxiety, dysphoria, and tension. Vanilla and baked apple cardamom flavored gum resulted in lower levels of negative affect while peppermint flavored gum was not different from the No Gum Control. These findings indicate that some flavors of gum are effective in reducing the negative affect associated with nicotine withdrawal and may serve as a valuable tool in helping smokers quit. PMID:20598808

Cohen, Lee M; Collins, Frank L; Vanderveen, Joseph W; Weaver, Cameron C

2010-06-10

270

Effect of Three Months' Frequent Use of Sugar-free Chewing Gum with and without Urea on Calculus Formation  

Microsoft Academic Search

Studies on the relationship between gum-chewing and calculus formation have produced contradictory results, and it is not clear whether frequent use of chewing gum promotes or inhibits calculus formation. Also, little is known about whether the addition of a small amount of urea to the chewing gum influences calculus formation. The aim of this investigation was to study the effect

S. Fure; P. Lingstrom; D. Birkhed

1998-01-01

271

Influence of gamma radiation on the physicochemical and rheological properties of sterculia gum polysaccharides  

NASA Astrophysics Data System (ADS)

Keeping in view the influence of gamma radiation on the physiochemical properties of the polysaccharides and their importance in the food and pharmaceutical industry, in the present study attempt has been made to investigate the effects of absorbed dose on FTIR, XRD, SEMs, absorbance, pH, solubility, water absorption capacity, emulsion stability and rheology of sterculia gum. Increase in solubility and decrease in swellability of gum has been observed on increasing the absorbed dose. The emulsion stability has improved for the gum sample irradiated with total dose of 8.10.2 kGy. Apparent viscosity of gum solution first increased with increase in dose from 0 to 8.10.2 kGy than decreased with regular trends with further increase in total absorbed dose. Flow behavior of gum solution shifted to Newtonian from non-Newtonian with increasing the dose.

Singh, Baljit; Sharma, Vikrant

2013-11-01

272

[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

273

Gum and deposit formation from jet-turbine and diesel fuels at 130C  

SciTech Connect

The ultimate objective of this work is to devise an accelerated test to compare rates of soluble gum and deposit formation from jet-turbine and diesel fuels in storage and of hard deposits in engines. This paper describes rates of oxygen absorption and gum formation in air at 130 C. For a single fuel or hydrocarbon, the rate of gum formation is closely proportional to the oxygen absorbed, even when this rate varies with purification and additives. In general, pure hydrocarbons absorb oxygen much faster than the fuels, but the fuels and 2-ethylnaphthalene give more gum for the oxygen absorbed than the other pure hydrocarbons. Gum has two main sources; one appears to be associated with the chain termination mechanism in oxidation, the other coupling of fuel molecules in the absence of oxygen. Other possibilities are discussed.

Mayo, F.R.; Lan, Bosco Y.

1986-01-01

274

Gum and deposit formation in diesel fuels. Final report, 1984-1988  

SciTech Connect

The authors examined two aspects of the stability of diesel fuels in storage: the formation of sediments in suspension, which subsequently clog filters, and the formation of soluble gum, which passes the filters but then forms hard deposits on hot engine parts. Research on fuel stability at SRI during the last 6 years has shown that soluble gum appears first on storage, and then part of it grows into sediment. If the oxidation mixture is agitated gently, the precipitating gum grows on the surface gum, and no loose sediment is formed. Three mechanisms of gum formation were distinguished: (1) a process intimately associated with chain propagation and termination during oxidation, (2) a coupling of fuel molecules by decomposing peroxides in the absence of oxygen, and (3) a condensation of naphthols and aldehydes from the oxidation of alkylnaphthalenes. The polymeric oxidation products from a JP-8 fuel are shown to be largely responsible for deposits in the Jet Fuel Thermal Oxidation Tester (JFTOT).

Mayo, F.R.; Mill, T.

1988-05-15

275

Sulfation of Aegle marmelos gum: synthesis, physico-chemical and functional characterization.  

PubMed

The present investigation was aimed at optimizing the conditions for preparing sulfated derivative of gum obtained from partially ripe fruits of Aegle marmelos. Elemental analysis, FTIR-ATR and NMR studies confirmed successful sulfation. The ratio of chlorosulfonic acid to pyridine exerted maximum influence on the degree of substitution followed by reaction temperature and reaction time. The sulfated derivative showed higher swelling in both acidic and alkaline pH as compared to unmodified gum. It also possessed higher negative zeta potential, higher viscosity, work of shear, firmness, consistency, cohesiveness and index of viscosity as compared to both unmodified gum as well as sodium alginate. Sulfated derivative was superior to unmodified gum and sodium alginate in terms of antimicrobial and anticoagulant activity. The sulfated sample appears to be a potential substitute over the unmodified gum sample and sodium alginate for modulating physicochemical properties of food and drug release dosage forms. PMID:23399204

Jindal, Manish; Rana, Vikas; Kumar, Vineet; Singh, Ram S; Kennedy, John F; Tiwary, Ashok K

2012-11-19

276

Young stars of low mass in the Gum nebula  

SciTech Connect

Observations are presented for four recently formed stars in the vicinity of the Gum nebula which are heavily obscured by surrounding dust and are associated with small reflection nebulae. HH46 is the only currently active star of the sample, and it is found to have a spectral type in the range of late G-early K, with superimposed emission lines of H-alpha, Ca II, Fe I, Fe II, and weak He I at near zero velocities. It is suggested that the observed scenario of low-mass stars in an older massive star environment may be analogous to the circumstances surrounding the birth of the sun. 53 refs.

Graham, J.A.; Heyer, M.H. (Carnegie Institution of Washington, Washington, DC (USA))

1989-06-01

277

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

278

MAGNETS  

DOEpatents

This patent relates to nmgnets used in a calutron and more particularly to means fur clamping an assembly of magnet coils and coil spacers into tightly assembled relation in a fluid-tight vessel. The magnet comprises windings made up of an assembly of alternate pan-cake type coils and spacers disposed in a fluid-tight vessel. At one end of the tank a plurality of clamping strips are held firmly against the assembly by adjustable bolts extending through the adjacent wall. The foregoing arrangement permits taking up any looseness which may develop in the assembly of coils and spacers.

Hofacker, H.B.

1958-09-23

279

Bayesian uncertainty analysis for a regression model versus application of GUM Supplement 1 to the least-squares estimate  

NASA Astrophysics Data System (ADS)

Application of least-squares as, for instance, in curve fitting is an important tool of data analysis in metrology. It is tempting to employ the supplement 1 to the GUM (GUM-S1) to evaluate the uncertainty associated with the resulting parameter estimates, although doing so is beyond the specified scope of GUM-S1. We compare the result of such a procedure with a Bayesian uncertainty analysis of the corresponding regression model. It is shown that under certain assumptions both analyses yield the same results but this is not true in general. Some simple examples are given which illustrate the similarities and differences between the two approaches.

Elster, Clemens; Toman, Blaza

2011-10-01

280

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

2012-02-15

281

Noncatalytic hydrolysis of guar gum under hydrothermal conditions.  

PubMed

Guar gum, a naturally occurring heteropolysaccharide made of mannose and galactose, was hydrolytically degraded without a catalyst in a batch reactor to produce water-soluble (WS) saccharides including mono- and oligosaccharides. The degradation was carried out under hydrothermal conditions over ranges of temperature from 180 to 240 degrees C and of reaction time from 3 to 60min. Guar gum was readily dissolved and hydrolyzed, and the major products identified in the WS components were oligosaccharides with degrees of polymerization up to about 20, monosaccharides containing mannose and galactose, and 5-hydroxymethyl-2-furaldehyde (5-HMF). At 200 degrees C, the oligosaccharide yield, obtained from the difference between the yields of the total WS saccharides and monosaccharides, showed the highest value of 94.4% at 7min among all conditions studied, on the basis of the saccharide content in the initial sample. The oligosaccharide yield decreased with reaction time, and the yield of monosaccharides correspondingly increased, and reached the highest value of 34.5% (mannose 22.8%, galactose 11.7%) at 60min. The monosaccharides produced were further decomposed to secondary products such as 5-HMF. The maximum yield of 5-HMF obtained was 26.3% at 220 degrees C and 30min. The production and the decomposition of galactose somewhat preceded those of mannose. PMID:16529730

Miyazawa, Tetsuya; Funazukuri, Toshitaka

2006-03-10

282

Gum and deposit formation from jet turbine and diesel fuels  

SciTech Connect

The objective of this work is to determine the chemistry of deposit formation in hot parts of jet turbine and diesel engines and, thus, to predict and prevent deposit formation. Previous work in the field has been extensive, but a real understanding of deposit formation has been elusive. Work at SRI started on the basis that deposit formation from fuels must take place stepwise and is associated with autoxidation and the hydroperoxide produced. More recent work showed that in the absence of dissolved oxygen, higher temperatures are required for deposit formation. A recent report indicated that gum and deposit formation proceed mainly through oxidation products of the parent hydrocarbon, coupling of these products to dimeric, trimeric and higher condensation products (partly or wholly by radicals from hydroperoxides) and precipitation of insoluble products. The authors know of no information on how these first precipitates are converted to the ultimate, very insoluble, carbonaceous materials that cause engine problems. The present paper describes measurements of rates of oxidation and soluble gum formation in both pure hydrocarbons and mixed hydrocarbon fuels. Some patterns appear that can be largely explained on the basis of what is known about co-oxidations of hydrocarbon mixtures.

Mayo, F.R.; Lan, B.Y.

1983-09-01

283

Evaluation of khaya gum as a directly compressible matrix system for controlled release.  

PubMed

Khaya gum has been evaluated as a controlled release agent in modified release matrices in comparison with hydroxypropylmethylcellulose (HPMC) using paracetamol (water soluble) and indometacin (water insoluble) as model drugs. Tablets were produced by direct compression and the in-vitro drug release was assessed in conditions mimicking the gastrointestinal system. Khaya gum matrices provided a controlled release of paracetamol for up to 5 h. The release of paracetamol from khaya gum matrices followed time-independent kinetics (n = 1.042) and release rates were dependent on the concentration of the drug present in the matrix. The addition of tablet excipients not only improved the mechanical properties of the tablet, but also altered the dissolution profile, except for dicalcium phosphate where the profile remained unchanged. HPMC could be used to control the drug release rates from khaya gum matrices and a combination of khaya gum and HPMC gave zero-order time-independent release kinetics. Indometacin exhibited a lag time in excess of 2 h, due to its insolubility at low pH, before the zero-order release was observed. Thus khaya gum matrices could be useful in the formulation of sustained release tablets for up to 5 h and the appropriate combination of khaya gum and HPMC could be used to provide a time-independent release for longer periods. PMID:15525442

Odeku, Oluwatoyin A; Fell, John T

2004-11-01

284

Reactivity recovery of guar gum coupled mZVI by means of enzymatic breakdown and rinsing  

NASA Astrophysics Data System (ADS)

Microscale zerovalent iron (mZVI) reduces chlorinated aliphatic hydrocarbons (CAHs) to harmless compounds, but the sedimentation of the mZVI particles in the injection fluid limits the injectability of the particles during field applications. In this study, mZVI particles in suspension were stabilized by green polymer guar gum, which had a positive impact on mZVI stability, but decreased the reactivity of the particles towards CAHs by 1 to 8 times. Guar gum (GG) was found to adsorb onto the mZVI surface, inhibiting contact between the chlorinated compounds and the reactive iron surface. Indications were found for intermolecular hydrogen bonding between mZVI and the guar gum. Subsequent addition of commercially available enzymes resulted in the cleavage of the polysaccharide guar gum into lower molecular fragments, but not in improved reactivity. The reactivity recovery of guar gum coupled mZVI was recovered after intensive rinsing of the iron particles, removing the guar gum fragments from the particles. Overall, this study shows that CAHs can be treated efficiently by guar gum stabilized mZVI after reactivation by means of enzymatic breakdown and rinsing.

Velimirovic, Milica; Chen, Hong; Simons, Queenie; Bastiaens, Leen

2012-11-01

285

Reactivity recovery of guar gum coupled mZVI by means of enzymatic breakdown and rinsing.  

PubMed

Microscale zerovalent iron (mZVI) reduces chlorinated aliphatic hydrocarbons (CAHs) to harmless compounds, but the sedimentation of the mZVI particles in the injection fluid limits the injectability of the particles during field applications. In this study, mZVI particles in suspension were stabilized by green polymer guar gum, which had a positive impact on mZVI stability, but decreased the reactivity of the particles towards CAHs by 1 to 8 times. Guar gum (GG) was found to adsorb onto the mZVI surface, inhibiting contact between the chlorinated compounds and the reactive iron surface. Indications were found for intermolecular hydrogen bonding between mZVI and the guar gum. Subsequent addition of commercially available enzymes resulted in the cleavage of the polysaccharide guar gum into lower molecular fragments, but not in improved reactivity. The reactivity recovery of guar gum coupled mZVI was recovered after intensive rinsing of the iron particles, removing the guar gum fragments from the particles. Overall, this study shows that CAHs can be treated efficiently by guar gum stabilized mZVI after reactivation by means of enzymatic breakdown and rinsing. PMID:23047137

Velimirovic, Milica; Chen, Hong; Simons, Queenie; Bastiaens, Leen

2012-09-20

286

The contrasting physiological and subjective effects of chewing gum on social stress.  

PubMed

Uncertainty exists with respect to the extent to which chewing gum may attenuate stress-induced rises in cortisol secretion (Johnson, Jenks, Miles, Albert, & Cox, 2011; Scholey et al., 2009; Smith, 2010). The present study used the Trier Social Stress Task (TSST: Kirschbaum, Pirke, & Hellhammer, 1993), a task known to elevate cortisol secretion (Kudielka, Schommer, Hellhammer, & Kirschbaum, 2004), in order to examine the moderating physiological and subjective effects of chewing gum on social stress. Forty participants completed the TSST either with or without chewing gum. As expected, completion of the TSST elevated both cortisol and subjective stress levels, whilst impairing mood. Although gum moderated the perception of stress, cortisol concentrations were higher following the chewing of gum. The findings are consistent with Smith (2010) who argued that elevations in cortisol following the chewing of gum reflect heightened arousal. The findings suggest that chewing gum only benefits subjective measures of stress. The mechanism remains unclear; however, this may reflect increased cerebral blood flow, cognitive distraction, and/or effects secondary to task facilitation. PMID:22123610

Gray, Gemma; Miles, Christopher; Wilson, Nigel; Jenks, Rebecca; Cox, Martin; Johnson, Andrew J

2011-11-15

287

Evaluation of Albizia procera gum as compression coating material for colonic delivery of budesonide.  

PubMed

The purpose of this research was to develop and evaluate Albizia procera gum as compression-coating polymer for colonic delivery of budesonide. Tablets were prepared by direct compression method using spray-dried lactose and microcrystalline cellulose as filler binders. The compatibility between the drug and the polymer was studied through TGA and FTIR spectroscopy. In vitro drug release were studied in dissolution media with or without 2% rat cecal contents while in vivo X-ray study was conducted on rabbits. The results indicate that procera gum and the drug were compatible with each other and tablet coated with procera gum was suitable for colonic delivery of drugs. PMID:23916644

Pachuau, Lalduhsanga; Mazumder, Bhaskar

2013-08-02

288

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

2012-09-16

289

Photosensitivity of heterojunctions formed by deposition of gum on a layered III VI semiconductor  

NASA Astrophysics Data System (ADS)

The list of materials showing promise for the production of photosensitive structures is extended to include an organic material of biological origin known as gum. The current-voltage characteristics of hetero-junctions formed by a gum layer and a layered semiconductor (InSe, GaSe) are studied. An attempt is made to relate some spectral features of the relative quantum efficiency of the structures (for example, nonzero photosensitivity beyond the fundamental absorption edge of the semiconductor material) to the deformation interaction between the condensed gum layer and the layered III VI semiconductor surface.

Drapak, S. I.; Kovalyuk, Z. D.

2007-09-01

290

Chios gum mastic: A review of its biological activities.  

PubMed

The resin of Pistacia lentiscus (L.) var. chia (Duham), an evergreen shrub belonging to the family Anacardiaceae and uniquely cultivated in southern Chios, is known as mastic. It has been used for more than 2500 years in traditional Greek medicine for treating several diseases such as gastralgia and peptic ulcers, while the actions of the gum are mentioned in the works of Herodotus, Dioscorides and Galen. Several Roman, Byzantine, Arab and European authors make extensive references to mastic's healing properties. Modern scientific research has justified the beneficial action of mastic to gastric diseases, by revealing its in vivo and in vitro activity against Helicobacter pylori, which is considered as the main cause for gastric ulcers. Furthermore, studies of the antimicrobial, antifungal, antioxidant, hypolipidemic, anti-inflammatory, anti-Crohn and anticancer activities of mastic have characterized it as a wide-range therapeutic agent and a potential source of nature-originated treatments. PMID:22414110

Paraschos, S; Mitakou, S; Skaltsounis, A-L

2012-01-01

291

Study of the reaction of grafting acrylamide onto xanthan gum.  

PubMed

The present study aimed to study the reaction conditions of grafting of acrylamide on xanthan gum. It was analyzed the influence of reaction conditions, mainly type of initiator activation, initiator concentration and initiator/acrylamide ratio, on graft parameters and copolymer properties. Potassium persulfate was employed as an initiator and heating or N,N,N',N'-tetramethylethylenediamine was used to activate the initiator. Reaction time and initiator concentration were varied and final values for grafting percentage and grafting efficiency were the same for both methods, whereas speed in reaching these values differs from one technique to another. We found that reaction time was inversely proportional to intrinsic viscosity, likely due to main chain degradation promoted by potassium persulfate (KPS); furthermore, the increasing in the KPS concentration lowers grafting percentage, acrylamide conversion and chain degradation, possibly as a result of O(2) formation at high KPS concentrations. PMID:22840001

Maia, Ana M S; Silva, Hugo V M; Curti, Priscila S; Balaban, Rosangela C

2012-05-27

292

Compounds from Gum Ammoniacum with Acetylcholinesterase Inhibitory Activity  

PubMed Central

The use of herbal medicinal preparations in dementia therapy has been studied based on experience from traditional medicine. A dichloromethane extract of gum ammoniacum, the gum-resin from Dorema ammoniacum D. Don had shown acetylcholinesterase (AChE) inhibitory activity in a previous study. The aim of this study was the isolation and characterization of the active compounds from this resin. The extract was investigated by a respective colorimetric microplate assay and the active zones were identified via TLC bioautography and isolated using several chromatographic techniques. The structures of the active components were characterized by one- and two-dimensional 1H and 13C NMR spectroscopy and mass spectrometry as (2?S,5?S)-2?-ethenyl-5?-(3-hy-droxy-6-methyl-4-oxohept-5-en-2-yl)-7-methoxy-2?-methyl-4H-spiro[chromene-3,1?-cyclopentane]-2,4-dione (1), which is an analogue of doremone A and a new natural compound, and as (2?S,5?R)-2?-ethenyl-5?-[(2R,4R)-4-hydroxy-6-methyl-3-oxohept-5-en-2-yl]-7-methoxy-2?-methyl-4H-spiro[chromene-3,1?-cyclo-pentane]-2,4-dione (2 = doremone A), (4E,8E)-1-(2,4-dihydroxyphenyl)-5,9,13-trimethyltetradeca-4,8,12-trien-1-one (3 = dshamirone), and 4,7-dihydroxy-3-[(2E,6E)-3,7,11-trimethyldodeca-2,6,10-trien-1-yl]-2H-chromen-2-one (4 = am-moresinol). Dshamirone turned out to be the most active compound with an IC50 value for AChE inhibitory activity of 23.5 ?M, whereas the other substances showed weak activity. The concentrations of the analytes in the resin were determined by HPLC as 3.1%, 4.6%, 1.9%, and 9.9%, respectively.

Adhami, Hamid-Reza; Lutz, Johannes; Kahlig, Hanspeter; Zehl, Martin; Krenn, Liselotte

2013-01-01

293

Polyelectrolyte complex materials consisting of antibacterial and cell-supporting layers.  

PubMed

The characterization of a polyelectrolyte complex material comprised of two biopolymers, a chitosan upper layer and a gellan gum under layer, is reported. It is shown that the upper layer of chitosan with incorporated levofloxacin displays an antibacterial activity, while the under layer of a gellan gum/TiO(2) composite supports the growth of fibroblastic cells. PMID:22223665

Mat Amin, Khairul Anuar; Gilmore, Kerry J; Matic, Jake; Poon, Stephen; Walker, Mark J; Wilson, Mark R; in het Panhuis, Marc

2011-12-30

294

Viscoelastic and fragmentation characters of model bolus from polysaccharide gels after instrumental mastication  

Microsoft Academic Search

Model bolus from polysaccharide gels was investigated by the stress-relaxation tests and particulate size analyses. Using two gelling agents, gellan gum and a composite of gellan\\/psyllium seed gums, gels with different physical properties (i.e., elastic gellan single gels and plastic composite gels) and gel hardness were prepared. Gels were masticated instrumentally in the presence or absence of artificial saliva to

Sayaka Ishihara; Makoto Nakauma; Takahiro Funami; Sachiko Odake; Katsuyoshi Nishinari

2011-01-01

295

40 CFR 454.20 - Applicability; description of the manufacture of gum rosin and turpentine subcategory.  

Code of Federal Regulations, 2013 CFR

40 Protection of Environment 31 2013-07-01...454.20 Section 454.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT...STANDARDS (CONTINUED) GUM AND WOOD CHEMICALS MANUFACTURING POINT...

2013-07-01

296

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

297

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

298

Xanthan Gum and Its Derivatives as a Potential Bio-polymeric Carrier for Drug Delivery System.  

PubMed

Xanthan gum is a high molecular weight natural polysaccharide produced by fermentation process. It consists of 1, 4-linked ?-D-glucose residues, having a trisaccharide side chain attached to alternate D-glucosyl residues. Although the gum has many properties desirable for drug delivery, its practical use is mainly confined to the unmodified forms due to slow dissolution and substantial swelling in biological fluids. Xanthan gum has been chemically modified by conventional chemical methods like carboxymethylation, and grafting such as free radical, microwave-assisted, chemoenzymatic and plasma assisted chemical grafting to alter physicochemical properties for a wide spectrum of biological applications. This article reviews various techniques utilized for modification of xanthan gum and its applications in a range of drug delivery systems. PMID:23607638

Badwaik, Hemant R; Giri, Tapan Kumar; Nakhate, Kartik T; Kashyap, Pranita; Tripathi, Dulal Krishna

2013-10-01

299

Cashew-tree (Anacardium occidentale L.) exudate gum: a novel bioligand tool.  

PubMed

The potential of bioaffinity as a tool for the study of biological-recognition mechanisms is gaining increasing value. The search continues for alternative products that can be obtained from renewable sources, such as the bark exudate gum from the cashew tree (Anacardium occidentale L.), which grows wild in many tropical and subtropical countries. Its potential use as a chromatographic matrix and/or for bioaffinity ligand for proteins (lectins) has been investigated. The crude gum was cross-linked in order to obtain a kind of chromatographic matrix (gel). To evaluate the gum's ability to retain glycoproteins (lectins), affinity chromatography was performed and, in addition, the reological behaviour of the gum was characterized. PMID:11834129

da Silveira Nogueira Lima, Raquel; Rabelo Lima, Jacira; Ribeiro De Salis, Celio; de Azevedo Moreira, Renato

2002-02-01

300

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

2007-10-03

301

Mechanical properties of gels formed by mixtures of mucilage gum ( Opuntia ficus indica) and carrageenans  

Microsoft Academic Search

The mechanical properties of gels formed by either mixtures of mucilage gum from Opuntia ficus indica and ?-carrageenan or i-carrageenan have been examined using dynamic shear and uniaxial compression measurements. A total polymer concentration of 2% (w\\/w) was used, the proportion of mucilage gum varying from 0 to 80% (w\\/w) and KCl or CaCl2 in the range from 12 to

L. Medina-Torres; E. Brito-De La Fuente; B. Torrestiana-Sanchez; S. Alonso

2003-01-01

302

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

303

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

304

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

305

Acacia gum and its use by bushbabies, Galago senegalensis (Primates: Lorisidae)  

Microsoft Academic Search

Lesser bushbabies (Galago senegalensis moholi)were studied by radiotracking over a 2-year period (August 1975 to August 1977)at a thornveld study site in the Northern Transvaal, South Africa. It was confirmed that the diet consisted exclusively of\\u000a plant exudates (gums) and arthropods;available fruits were never eaten. The gums were taken from the trunks and branches of Acaciatrees, particularly from Acacia karroo(the

S. K. Bearder; R. D. Martin

1980-01-01

306

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

Microsoft Academic Search

Nicotine replacement therapies (NRT) are prescribed in smoking cessation programmes to help smokers stop smoking. The ideal\\u000a dosage of NRT should control cravings and withdrawal symptoms but avoid adverse reactions. This report describes a case of\\u000a adverse reaction to nicotine gum in a female Malay smoker. Assays taken 2h after the gum, showed that her plasma cotinine\\/nicotine\\u000a ratio was 0.4,

Alyson Bond; Kim Wolff

2008-01-01

307

Injectivity improvement of xanthan gums by enzymes: Process design and performance evaluation  

SciTech Connect

Injectability and filterability of xanthan gum dispersions, especially in hard brines, can be considerably improved by successive use of cellulase and alkaline protease enzyme treatments. A thorough optimization of the different parameters controlling enzymatic activity has led to an original clarification process. Improvements observed in flow behavior of treated xanthan gum solutions through reservoir rocks is the result of almost complete elimination of both insoluble bacterial cells and microgels.

Kohler, N.; Lonchamp, D.; Thery, M.

1987-07-01

308

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

309

GUM Analysis for SIMS Isotopic Ratios in BEP0 Graphite Qualification Samples, Round 2  

SciTech Connect

This report describes GUM calculations for TIMS and SIMS isotopic ratio measurements of reactor graphite samples. These isotopic ratios are used to estimate reactor burn-up, and currently consist of various ratios of U, Pu, and Boron impurities in the graphite samples. The GUM calculation is a propagation of error methodology that assigns uncertainties (in the form of standard error and confidence bound) to the final estimates.

Gerlach, David C.; Heasler, Patrick G.; Reid, Bruce D.

2009-01-01

310

THE EFFECT OF GUM SHELLAC SOLUTION ON THE SURFACE TENSION OF RABBIT SERUM  

PubMed Central

Following the intravenous injection of a gum shellac solution which alters the peripheral blood picture there is an increase in the time-drop of the diluted serum. This is believed to indicate changes in the physicochemical state of the plasma. This gum shellac solution behaves as a surface-active substance; its effect on the surface tension of serum is hindered by the du Noy phenomenon of adsorption on serum molecules.

Hayman, J. M.

1927-01-01

311

Biosynthetic pathway of sugar nucleotides essential for welan gum production in Alcaligenes sp. CGMCC2428  

Microsoft Academic Search

Welan gum is a microbial polysaccharide produced by Alcaligenes sp. CGMCC2428 that has d-glucose, d-glucuronic acid, d-glucose, and l-rhamnose as the main structural unit. The biosynthetic pathway of sugar nucleotides essential for producing welan gum in\\u000a this strain was established in the following ways: (1) the detection of the presence of several intermediates and key enzymes;\\u000a (2) the analysis of

Hui Li; Hong Xu; Hao Xu; Sha Li; Ping-Kai Ouyang

2010-01-01

312

Influence of gum tragacanth on the physicochemical and rheological properties of kashk.  

PubMed

In this study, the physicochemical properties of a low-fat dried yogurt paste (kashk) were determined, and the effects of different concentrations (0, 01, 03 and 05% w/w) of gum tragacanth exudates from Astragalus gossypinus on the stability and texture of the samples were investigated by measuring amount of syneresis, turbidity, particle size distribution (PSD), flow behaviour and viscoelastic properties. The flow behaviour index was not very sensitive to the concentration of gum, while a remarkable concentration dependency of the power-law consistency coefficient and Herschel-Bulkley yield stress was observed. The initial increase in the gum concentration at 01 and 03% levels led to a higher degree of syneresis, which was related to the depletion flocculation mechanism. However, the reduced amount of syneresis in samples containing 05% gum tragacanth was attributed to the significant increase in viscosity of the continuous phase, which is also accompanied by trapping of the aggregated casein particles. The presence of 3% salt in the samples may have led to the neutralization of charges on the surface of gum tragacanth; consequently, the non-adsorbing behaviour of high-ionic-strength polysaccharides inhibited the formation of electrostatic protein-polysaccharide complexes. Furthermore, maximum values of polydispersity, syneresis and tan ? at high frequencies were found in samples containing 01% gum tragacanth. PMID:23171586

Shiroodi, Setareh Ghorban; Mohammadifar, Mohammad Amin; Gorji, Elham Ghorbani; Ezzatpanah, Hamid; Zohouri, Nilofar

2012-02-01

313

Xanthomonas campestris pv. campestris gum Mutants: Effects on Xanthan Biosynthesis and Plant Virulence  

PubMed Central

Xanthan is an industrially important exopolysaccharide produced by the phytopathogenic, gram-negative bacterium Xanthomonas campestris pv. campestris. It is composed of polymerized pentasaccharide repeating units which are assembled by the sequential addition of glucose-1-phosphate, glucose, mannose, glucuronic acid, and mannose on a polyprenol phosphate carrier (L. Ielpi, R. O. Couso, and M. A. Dankert, J. Bacteriol. 175:24902500, 1993). A cluster of 12 genes in a region designated xpsI or gum has been suggested to encode proteins involved in the synthesis and polymerization of the lipid intermediate. However, no experimental evidence supporting this suggestion has been published. In this work, from the biochemical analysis of a defined set of X. campestris gum mutants, we report experimental data for assigning functions to the products of the gum genes. We also show that the first step in the assembly of the lipid-linked intermediate is severely affected by the combination of certain gum and non-gum mutations. In addition, we provide evidence that the C-terminal domain of the gumD gene product is sufficient for its glucosyl-1-phosphate transferase activity. Finally, we found that alterations in the later stages of xanthan biosynthesis reduce the aggressiveness of X. campestris against the plant.

Katzen, Federico; Ferreiro, Diego U.; Oddo, Cristian G.; Ielmini, M. Veronica; Becker, Anke; Puhler, Alfred; Ielpi, Luis

1998-01-01

314

Chewing gum may be an effective complementary therapy in patients with mild to moderate depression.  

PubMed

Previous studies indicated that chewing gum may relieve stress and depression. There have, however, not been a significant number of studies on clinical usage of chewing gum. In the present study, 30 patients with mild to moderate depression were given either medication combined with chewing gum, or medication only, for 6 weeks. Turkish adaptation of Hamilton Rating Scale for Depression (HAM-D) was used to measure depression levels. Assessments were conducted by the same physician both before, and after treatment. The physician who was responsible for the assessment was not aware of the group allocation. Changes in main HAM-D scores and each item were analyzed by independent samples t test and Chi-Square test, respectively. Those patients who were administrated chewing gum responded better to the treatment than patients who took medication only. The most beneficial effect of chewing gum was observed on the gastrointestinal symptoms, e.g. loss of appetite, and flatulence among others. These results indicate that chewing gum may not be directly effective on depressed mood; however, it may reduce the symptoms originating from depression. PMID:23415985

Erbay, Furkan Muhammed; Ayd?n, Nazan; Sat?-K?rkan, Tlay

2013-02-12

315

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; Pouso-Ferreira, P; Salmern, C; Capilla, E; Navarro, I; Gutirrez, J; Oliva-Teles, A

2012-07-05

316

Binding effectiveness of Colocassia esculenta gum in poorly compressible drugs-paracetamol and metronidazole tablet formulations.  

PubMed

The effectiveness of a polysaccharide gum obtained from the cormels of Colocassia esculenta was evaluated comparatively with acacia and methylcellulose as binders in the formulation of poorly compressible drugs. The granules of these drugs produced by wet massing method using colocassia and acacia gums as binders have high compressibility index indicating poor flow. Based on this parameter, the granules produced with methylcellulose as binder seem to flow better. The properties of tablets evaluated include breaking strength, friability, disintegration time and dissolution rate. The new polysaccharide gum showed better concentration-strength profile than acacia while methylcellulose yielded mechanically more stable tablets than the two binders. The resistance of tablets to abrasion was poor in metronidazole tablets formulated with colocassia gum. The in vitro availability characteristics showed that tablets produced with the new gum show acceptable disintegration time and release profile within a certain range of its concentration in tablets. At 4% w/w nominal concentration of colocassia gum in metronidazole tablets and 6% w/w in paracetamol, tablets show very long disintegration time and prolonged release profile. The binders used for comparison yielded tablets that show better in vitro release characteristics. PMID:10920535

Chukwu, K I; Udeala, O K

317

The effect of mastic gum on Helicobacter pylori: a randomized pilot study.  

PubMed

Our aim was to study the effect of pure mastic gum on Helicobacter pylori (H. pylori) eradication in patients suffering from an H. pylori infection Fifty two patients were randomized to receive either 350mg three times a day (tid) of pure mastic gum for 14 days (Group A), or 1,05g tid of pure mastic gum (Group B) for 14 days, or pantoprazole 20mg twice a day (bd) plus pure mastic gum 350mg tid for 14 days (Group C) or pantoprazole 20mg bd plus amoxicillin 1g bd plus clarithromycin 500mg bd for 10 days (Group D). All patients harboured H. pylori before entering the study and that was confirmed by a (13)C urea breath test (UBT). H. pylori eradication was tested by a UBT 5 weeks after completion of the eradication regime. Eradication of H. pylori was confirmed in 4/13 patients in Group A and in 5/13 in Grour B. No patient in Group C achieved eradication whereas 10/13 patients in Group D had a negative UBT. There were no statistically significant differences in mean UBT values in Groups A, B, C although there was a trend in Group A (p=0.08) and in Group B (p=0.064). The difference was significant in Group D (p=0.01). All patients tolerated mastic gum well and no serious adverse events were reported. Mastic gum has bactericidal activity on H. pylori in vivo. PMID:19879118

Dabos, K J; Sfika, E; Vlatta, L J; Giannikopoulos, G

2009-10-29

318

Gum and deposit formation from jet-turbine and diesel fuels at 100 C  

SciTech Connect

Rates of oxidation and gum formation for six hydrocarbons, three jet-turbine fuels and three diesel fuels have been measured at 100 C in the presence of t-Bu2O2 tert-butyl-peroxide as initiator. Four of six fuels oxidize faster at 100 C than in previous work at 130 C with initiator. Four any single substrate, the amount of gum produced for the oxygen absorbed is similar at 100 and 130 C even with large changes in rates and t-Bu2O2 concentrations. Thus, one mechanism of gum formation is intimately associated with oxidation. The effects of t-Bu2O2 concentration on the rates of oxygen absorption and gum formation show that gum formation is associated with chain termination by two peroxy radicals. In general, the pure hydrocarbons have long kinetic chains and give good yields of hydroperoxides. The fuels give short kinetic chains and produce little hydroperoxide but but much more gum formation is the coupling of substrates by peroxides in the absence of oxygen. The mechanism, condensation of oxidation products from alkylnaphthalenes, is also proposed.

Mayo, F.R.; Lan, B.Y.

1987-01-01

319

Antihyperglycemic and antihyperlipidemic effects of guar gum on streptozotocin-induced diabetes in male rats  

PubMed Central

Background: Herbal medicine is widely used in the treatment of diseases like diabetes mellitus. We investigated the effects of guar gum in diabetic rats for the reduction of the risk of diabetes and cardiovascular disease. Dietary pattern emphasizing foods high in complex carbohydrates and fiber are associated with low blood glucose and cholesterol levels. Materials and Methods: Diet containing 0%, 5%, 10% and 20% (w/w) guar gum was fed to diabetic rats for 28 days. Blood serum glucose, triglycerides, cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol levels, atherogenic index levels, body weights and food intake were monitored at 0, 7.14 and 28 days after induction of diabetes. Results: In spite of the fact that diabetes elevated blood lipids in all rats after 14 days, the guar gum diet significantly decreased the serum concentration of cholesterol, triacylglicerols and LDL-C and atherogenic index. The most significant result in this study was the reduction of blood glucose in diabetic rats treated with the guar gum diet after 28 days versus non- and glibenclamide-treated rats. The gum promoted a general improvement in the condition of the diabetic rats in body weight and food intake in comparison with nontreated rats. Conclusion: The results of this research suggest that guar gum was significantly effective in comparison with glibenclamide in the treatment of hyperlipidemia and hyperglycemia in diabetes rats. Therefore, it may be suggested as a reliable fiber in diabetic regimes in diabetic patients.

Saeed, Samarghandian; Mosa-Al-Reza, Hadjzadeh; Fatemeh, Amin Nya; Saeideh, Davoodi

2012-01-01

320

Studies on the rheological properties and functional potentials of achi ( Brachystegea eurycoma) and ogbono ( Irvingia gabonesis) seed gums  

Microsoft Academic Search

Water soluble gums were extracted from seeds of achi (Brachystegea eurycoma) and Ogbono (Irvingia gabonesis). The rheological properties of each gum were studied at temperatures from between 1070C at 1.0, 1.5, 2.0, and 2.5% concentrations. The effects of small quantities of the gums on some of the quality characteristics of an ice cream mix were investigated. These characteristics were compared

A Uzomah; R. N Ahiligwo

1999-01-01

321

Composition and physicochemical properties of locust bean gum extracted from whole seeds by acid or water dehulling pre-treatment  

Microsoft Academic Search

The purpose of this study was to extract locust bean gum (LBG) from whole seeds by two different dehulling pre-treatments. The first process consisted in separating the endosperm (gum) from the hull and the germ after seeds pre-treatment with boiling water. The second one used acidic pre-treatment. Then the composition and the physicochemical characteristics of the isolated gum were studied

Patrick Aubin Dakia; Christophe Blecker; Christelle Robert; Bernard Wathelet; Michel Paquot

2008-01-01

322

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.

Toms, S. A.; Saavedra, R.; Cruz, A.; Pedroza-Islas, R.; San Martn, E.

2005-06-01

323

Texture of low-fat Iranian White cheese as influenced by gum tragacanth as a fat replacer.  

PubMed

The effect of different concentrations of gum tragacanth on the textural characteristics of low-fat Iranian White cheese was studied during ripening. A batch of full-fat and 5 batches of low-fat Iranian White cheeses with different gum tragacanth concentrations (without gum or with 0.25, 0.5, 0.75, or 1 g of gum/kg of milk) were produced to study the effects of fat content reduction and gum concentration on the textural and functional properties of the product during ripening. Cheese samples were analyzed with respect to chemical, color, and sensory characteristics, rheological parameters (uniaxial compression and small-amplitude oscillatory shear), and microstructure. Reducing the fat content had an adverse effect on cheese yield, sensory characteristics, and the texture of Iranian White cheese, and it increased the instrumental hardness parameters (i.e., fracture stress, elastic modulus, storage modulus, and complex modulus). However, increasing the gum tragacanth concentration reduced the values of instrumental hardness parameters and increased the whiteness of cheese. Although when the gum concentration was increased, the low-fat cheese somewhat resembled its full-fat counterpart, the interaction of the gum concentration with ripening time caused visible undesirable effects on cheese characteristics by the sixth week of ripening. Cheeses with a high gum tragacanth concentration became very soft and their solid texture declined somewhat. PMID:17699022

Rahimi, J; Khosrowshahi, A; Madadlou, A; Aziznia, S

2007-09-01

324

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

SciTech Connect

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 gum tended to have a lower energy demand than mix with large amounts of guar gum. This was especially pronounced in mixes with 50% 42 high fructose corn syrup and/or 50% 36 DE corn syrup solids.

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

1985-01-01

325

Characterization of khaya gum as a binder in a paracetamol tablet formulation.  

PubMed

The influence of khaya gum, a binding agent obtained from Khaya grandifolia (Meliaceae family), on the bulk, compressional, and tabletting characteristics of a paracetamol tablet formulation was studied in comparison with the effects of two standard binders: polyvinylpyrrolidone (PVP; molecular weight 40,000) and gelatin. The relative ability of khaya gum to destroy any residual microbial contamination in the binder or in the formulation during tabletting was also studied using Bacillus subtilis spores as a model. Formulations containing khaya gum exhibited more densification than formulations containing PVP and gelatin during die filling, but less densification due to rearrangement at low pressures. The mean yield pressure of the formulation particles obtained from Heckel plots, and another pressure term, also inversely related to plasticity, obtained from Kawakita plots, showed dependence on the nature and concentration of the binder, with formulations containing khaya gum exhibiting the lowest and highest values respectively. The values of the pressure terms suggest that the yield pressure relates to the onset of plastic deformation during compression, while the Kawakita pressure relates to the total amount of plastic deformation occurring during the compression process. Tablets made from formulations containing khaya gum had the lowest tensile strength values but also the lowest tendency to laminate or cap, as indicated by their lowest brittleness. All the tablets had friability values < 1% at higher concentrations of the three binders. In addition, khaya gum demonstrated a comparable ability to destroy microorganisms in the formulation during tabletting as the two binders. The characterization of the formulations suggests that khaya gum can be developed into a commercial binding agent for particular tablets. PMID:12026225

Odeku, O A; Itiola, O A

2002-03-01

326

Mutans streptococci dose response to xylitol chewing gum.  

PubMed

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 at baseline, 5 wks, and 6 mos, and were cultured on modified Mitis Salivarius agar for mutans streptococci and on blood agar for total culturable flora. At 5 wks, mutans streptococci levels in plaque were 10x lower than baseline in G3 and G4 (P = 0.007/0.003). There were no differences in saliva. At 6 mos, mutans streptococci in plaque for G3 and G4 remained 10x lower than baseline (P = 0.007/0.04). Saliva for G3 and G4 was lower than baseline by 8 to 9x (P = 0.011/0.038). Xylitol at 6.44 g/day and 10.32 g/day reduces mutans streptococci in plaque at 5 wks, and in plaque and unstimulated saliva at 6 mos. A plateau effect is suggested between 6.44 g and 10.32 g xylitol/day. PMID:16434738

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

2006-02-01

327

Physical properties of gum karaya-starch-essential oil patches.  

PubMed

Essential oils are used in foods, cosmetics, and pharmaceuticals. Despite the recent marketing of novel essential-oil-containing patches, there is no information on their production, constituents, or physical properties. The objectives of this study were to produce essential-oil patches and characterize their physical properties. The essential oil of Lavandula angustifolia (lavender) was included at concentrations of 2.5% to 10% in patches manufactured from the exudate gum karaya, propylene glycol, glycerol, emulsifier, and optionally, potato starch as filler. Inclusion of essential oil reduced patch strength, stiffness, and elasticity relative to patches without essential oil. Inclusion of starch in the essential-oil patches strengthened them, but reduced their elasticity. Patches' adhesion to substrate was examined by both peeling and probe-tack tests: the higher the inclusion of essential oils within the patch, the larger the decrease in its adhesion to substrate. Addition of starch to essential-oil-containing patches increased their adhesion relative to their essential-oil-only counterparts. Scanning electron micrographs of the patches provided evidence of entrapped starch granules. Although inclusion of essential oil reduced both the mechanical properties and adhesion of the patches, a high proportion of essential oil can still be included without losing patch integrity or eliminating its adhesiveness to the skin. PMID:20711695

Shcherbina, Yulia; Roth, Zvi; Nussinovitch, Amos

2010-08-14

328

In vitro and in vivo activities of Chios mastic gum extracts and constituents against Helicobacter pylori.  

PubMed

The extracts and pure major constituents of Chios mastic gum (resin of Pistacia lentiscus var. chia) were tested for their activities against Helicobacter pylori. A total mastic extract without polymer (TMEWP) was prepared after removal of the contained insoluble polymer in order to ameliorate solubility and enhance in vivo activity. Administration of TMEWP to H. pylori SS1-infected mice over the period of 3 months with an average dose of 0.75 mg/day led to an approximately 30-fold reduction in the H. pylori colonization (1.5 log CFU/g of tissue). However, no attenuation in the H. pylori-associated chronic inflammatory infiltration and the activity of chronic gastritis was observed. To further characterize potential active mastic constituents, the TMEWP was separated into an acidic and a neutral fraction. Both were extensively characterized by nuclear magnetic resonance and mass spectroscopy to elucidate the structure of the components contained within each fraction. After chromatographic separation, the acid fraction gave the major triterpenic acids, while the neutral fraction gave several triterpenic alcohols and aldehydes. Mastic extracts and isolated pure triterpenic acids were tested for in vitro activity against a panel of 11 H. pylori clinical strains. The acid fraction was found to be the most active extract (minimum bactericidal concentration [MBC], 0.139 mg/ml), and the most active pure compound was isomasticadienolic acid (MBC, 0.202 mg/ml [0.443 mM]). Our results show that administration of TMEWP may be effective in reducing H. pylori colonization and that the major triterpenic acids in the acid extract may be responsible for such an activity. PMID:17116667

Paraschos, Sotirios; Magiatis, Prokopios; Mitakou, Sofia; Petraki, Kalliopi; Kalliaropoulos, Antonios; Maragkoudakis, Petros; Mentis, Andreas; Sgouras, Dionyssios; Skaltsounis, Alexios-Leandros

2006-11-20

329

Hydrocolloids in emulsions: particle size distribution and interfacial activity  

Microsoft Academic Search

The emulsification properties of 14 hydrocolloid gums (propylene glycol alginate, gellan, carrageenan, pectin, methylcellulose, microcrystalline cellulose, gum arabic, locust bean gum, guar, xanthan, mustard, flaxseed, fenugreek, oat) were investigated. Gum dispersions were prepared in water (0.5%) and emulsified with 40% oil using a Polytron homogenizer. Emulsion stability was determined by centrifugation and storage time, surface and interfacial tension by Du

X Huang; Y Kakuda; W Cui

2001-01-01

330

Final report of the safety assessment of Acacia catechu gum, Acacia concinna fruit extract, Acacia dealbata leaf extract, Acacia dealbata leaf wax, Acacia decurrens extract, Acacia farnesiana extract, Acacia farnesiana flower wax, Acacia farnesiana gum, Acacia senegal extract, Acacia senegal gum, and Acacia senegal gum extract.  

PubMed

These ingredients are derived from various species of the acacia plant. Only material derived from Acacia senegal are in current use according to industry data. The concentration at which these ingredients are reported to be used ranges from 9% in mascara to 0.0001% in tonics, dressings, and other hair-grooming aids. Gum arabic is a technical name for Acacia Senegal Gum. Gum arabic is comprised of various sugars and glucuronic acid residues in a long chain of galactosyl units with branched oligosaccharides. Gum arabic is generally recognized as safe as a direct food additive. Little information is available to characterize the extracts of other Acacia plant parts or material from other species. Acacia Concinna Fruit Extract was generally described as containing saponins, alkaloids, and malic acid with parabens and potassium sorbate added as preservatives. Cosmetic ingredient functions have been reported for Acacia Decurrens Extract (astringent; skin-conditioning agent--occlusive) and Acacia Farnesiana Extract (astringent), but not for the other Acacias included in this review. Toxicity data on gum arabic indicates little or no acute, short-term, or subchronic toxicity. Gum arabic is negative in several genotoxicity assays, is not a reproductive or developmental toxin, and is not carcinogenic when given intraperitoneally or orally. Clinical testing indicated some evidence of skin sensitization with gum arabic. The extensive safety test data on gum arabic supports the safety of Acacia Senegal Gum and Acacia Senegal Gum Extract, and it was concluded that these two ingredients are safe as used in cosmetic formulations. It was not possible, however, to relate the data on gum arabic to the crude Acacias and their extracts from species other than Acacia senegal. Therefore, the available data were considered insufficient to support the safety of Acacia Catechu Gum, Acacia Concinna Fruit Extract, Acacia Dealbata Leaf Extract, Acacia Dealbata Leaf Wax, Acacia Decurrens Extract, Acacia Farnesiana Extract, Acacia Farnesiana Flower Wax, Acacia Farnesiana Gum, and Acacia Senegal Extract in cosmetic products. The additional data needed to complete the safety assessment for these ingredients include (1) concentration of use; (2) identify the specific chemical constituents, and clarify the relationship between crude Acacias and their extracts and the Acacias and their extracts that are used as cosmetic ingredients; (3) data on contaminants, particularly relating to the presence of pesticide residues, and a determination of whether Acacia melanoxylon is used in cosmetics and whether acamelin (a quinone) and melacacidin (a flavin) are present in the Acacias that are being used; (4) skin sensitization study (i.e., dose response to be determined); (5) contact urticaria study at use concentration; and (6) ultraviolet (UV) absorption spectrum; if there is significant absorbance in the UVA or UVB range, then a photosensitization study may be needed. It was also noted that other data may be needed after clarification of the chemical constituents of the Acacia-derived ingredients. PMID:16422266

2005-01-01

331

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 10mPas in 5% aqueous solution, whereas 1% solution of guar gum shows range from 2,000 to 3,000mPas. 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.

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

2008-01-01

332

Evaluation of the effects of khaya gum on the mechanical and release properties of paracetamol tablets.  

PubMed

A study of the comparative effects of khaya gum and two standard binding agents-polyvinylpyrrolidone (PVP) and gelatin--on crushing strength and friability, and the disintegration and dissolution characteristics of paracetamol tablets was made. The crushing strength-friability ratio (CSFR), the disintegration times, D, and the dissolution times t50, t90, and t1 (derived from the equation of Noyes and Whitney), all increased with an increase in binder concentration; however, the dissolution rate constants, k1 and k2, decreased. The ranking for the values of CSFR for tablets containing the different binders was PVP > gelatin > khaya gum. The ranking for D and the dissolution times was gelatin > khaya gum > PVP, whereas the ranking for the dissolution rate constants was PVP > khaya gum > gelatin. There were significant linear correlations between CSFR, D, t50, t90, and t1 for the tablets. There were also significant correlations between k1 and D, t50, t90, and t1, and between k2 and t90. The results suggest that khaya gum could be useful as an alternative binding agent to produce tablets with particular mechanical strength and drug release profiles. PMID:12741612

Odeku, O A; Itiola, O A

2003-03-01

333

Long-term effect of xylitol gum use on mutans streptococci in adults.  

PubMed

Many studies have shown the effects of chewing xylitol gum on mutans streptococci (MS) over short- and long-term periods in children; however, few studies have addressed long-term periods in adults. The objective of this investigation was to examine for 6 months the effects of chewing xylitol gum on MS in saliva and plaque in 127 adults (mean age 28.0 years). The participants were assigned to three groups according to gum type, in part taking preference for flavor into account and in part at random: xylitol (XYL), maltitol (MAL) and control (CR); 33, 34 and 27 subjects in each group, respectively, completed the trial. Daily gum use of the XYL and MAL groups was 7.9 and 7.1 g, respectively. MS levels, which declined significantly in saliva (p < 0.05) and plaque (p < 0.001) in the XYL group after 6 months, exhibited a significant increase in plaque in the MAL group (p < 0.001). Differences in relative changes of MS levels in plaque during the experimental period were significant between the XYL group and the CR (p < 0.05) and MAL groups (p < 0.001). Differences in relative change of amount of plaque during the experimental period were not statistically significant between the groups. The present study demonstrated that chewing xylitol gum for 6 months continued to inhibit the growth of mutans streptococci in adults. PMID:17426399

Haresaku, S; Hanioka, T; Tsutsui, A; Yamamoto, M; Chou, T; Gunjishima, Y

2007-01-01

334

Inter- and Intra-Manufacturer Variability in Pharmaceutical Grades and Lots of Xanthan Gum  

PubMed Central

A pharmaceutical formulation typically contains one or more excipients in addition to the active pharmaceutical ingredient(s). Though excipients have been considered inert components of a formulation, variability in their properties has been shown to affect the performance of drug dosage forms and delivery systems. This study investigates the inter- and intra-manufacturer variability among different NF grades and lots of xanthan gum made by two manufacturers. As many formulators rely on compendial standards to monitor and control the variability of excipients, this study focuses on the adequacy of the NF specifications, in particular the viscosity specification, to discern the variability in solution properties of different pharmaceutical grades and lots of xanthan gum. All the grades and lots in this study were NF grade materials. Xanthan gum solutions were prepared in accordance with NF test methodology and were rheologically evaluated using a rotational rheometer. Both steady shear measurements and small amplitude oscillatory measurements were carried out on 1% w/w xanthan gum solutions. Results showed significant inter- and intra-manufacturer variability among the NF grades and lots of xanthan gum that was not reflected in the NF viscosity test specifications.

Thacker, Ankur; Fu, Shao; Boni, Riccardo L.

2010-01-01

335

Evaluation of masticatory function after maxillectomy using a colour-changing chewing gum.  

PubMed

The purpose of this study was to identify the risk factors associated with the masticatory dysfunction after maxillectomy using a colour-changing chewing gum. Thirty-nine patients who underwent maxillectomy between January 2002 and May 2010 in the Department of Kobe University Hospital were recruited for this study. There were 20 male and 19 female subjects, with a median age of 733years (range of 44-90) at the time of surgery. The intra-oral conditions after maxillectomy were classified by HS classification, and the masticatory function was evaluated by a colour-changing chewing gum and the results of a modified Sato's questionnaire. The scores of the colour-changing gum were closely correlated with the scores of the modified Sato's questionnaire (r=0661, P<001). A logistic regression analysis with the outcome variable of the gum test <4 demonstrated that significant predictors for the masticatory dysfunction were the number of anchor teeth ?2 and a soft palate defect. A colour-changing gum was found to be useful for evaluating the post-operative masticatory function, and it was important to conserve the anchor teeth and the soft palate to avoid masticatory dysfunction. PMID:23278102

Shibuya, Y; Ishida, S; Kobayashi, M; Hasegawa, T; Nibu, K; Komori, T

2012-12-20

336

Guar gum and guar gum-oligomeric poly(vinyl alcohol) blends as novel flocculants for kaolinated waste water.  

PubMed

This is probably the first report on kaolin flocculation done with aqueous guar gum (GG) at various pH. Dynamic light scattering and reduced viscosity proved the polyelectrolytic feature (zeta potential) of aqueous GG which changed on changing pH. Interestingly, the molecular size of GG did not always increased with rising zeta potential due to strong intermolecular repulsion leading to macromolecular recoiling. Best pH range for settling was 4.0-5.0 which included isoelectric point (IEP) of kaolin. Post-settling turbidity was also acceptable at that range. Optimized GG was further blended with oligomeric poly (vinyl alcohol) (PVA) (Mn 14,000) to prepare a new set of flocculant. Oligomeric PVA was previously optimized at similar pH as excellent kaolin flocculant in our earlier investigation. All GG-PVA blends including neat GG exhibited faster settling than neat PVA. However, settling times of all blend compositions were slightly greater than that of neat GG except for few cases where the post settling turbidity was found significantly lower than all our previous investigations. PMID:23567291

Nasim, Tanbir; Panda, Asit Baran; Bandyopadhyay, Abhijit

2013-04-06

337

The Anticariogenic Effect of Sugar-Free Gum Containing CPP-ACP Nanocomplexes on Approximal Caries Determined Using Digital Bitewing Radiography  

Microsoft Academic Search

This study investigated, using digital bitewing radiography, the progression and regression of approximal caries in adolescent subjects chewing a sugar-free gum containing 54 mg CPP-ACP relative to the identical gum without CPP-ACP. 2,720 subjects from 29 schools were randomly assigned to one of the two gums and were instructed to chew their assigned gum for 3 10 min\\/day, with

M. V. Morgan; G. G. Adams; D. L. Bailey; C. E. Tsao; S. L. Fischman; E. C. Reynolds

2008-01-01

338

A ninety-day oral toxicity study of a new type of processed gum arabic, from Acacia tree ( Acacia senegal) exudates, in F344 rats  

Microsoft Academic Search

This study was designed to evaluate and characterize any subchronic toxicity of a new type of gum arabic (SUPER GUM [Acacia(sen)SUPER GUM]), a naturally processed polysaccharide exudate from gum acacia trees (Acacia senegal), when administered to both sexes of F344 rats at dietary levels of 0 (control), 1.25%, 2.5%, and 5.0% (10 rats\\/sex\\/group). During the study, the treatment had no

Y. Doi; T. Ichihara; A. Hagiwara; N. Imai; S. Tamano; H. Orikoshi; K. Ogasawara; Y. Sasaki; M. Nakamura; T. Shirai

2006-01-01

339

Analytical, Nutritional and Clinical Methods Section Quantitative analysis of a-pinene and b-myrcene in mastic gum oil using FT-Raman spectroscopy  

Microsoft Academic Search

a-Pinene and b-myrcene are compounds that are contained in mastic gum in high concentrations.The b-myrcene percentage determines the marketability of mastic gums.The chemical composition of mastic gum oil of a representative resin quality was evaluated by gas chromatography-mass spectrometry (GC-MS) technique.FT-Raman spectroscopy, based on band intensity measurements, was used for the determination of a-pinene and b-myrcene content in mastic gum.Bands

D. Daferera; C. Pappas; P. A. Tarantilis; M. Polissiou

340

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

341

Is Chios mastic gum effective in the treatment of functional dyspepsia? A prospective randomised double-blind placebo controlled trial  

Microsoft Academic Search

BackgroundHerbal remedies are increasingly popular for the treatment of functional dyspepsia. Chios mastic gum is a resinous exudate from the stem of Pistacia lentiscus var. chia. It is a traditional natural remedy used throughout the eastern Mediterranean.The aim of this study was to assess the efficacy of Chios mastic gum in patients with functional dyspepsia.

Konstantinos J. Dabos; Ekaterini Sfika; Lisa J. Vlatta; Despoina Frantzi; Georgios I. Amygdalos; Georgios Giannikopoulos

2010-01-01

342

Effect of the Variation of Moisture Content on the Properties of Nigerian Gum Arabic Bonded Foundry Sand Moulds  

Microsoft Academic Search

2 Abstract: Each of four commercial grades of Nigerian acacia species (gum Arabic) had been investigated in previous researches for binding foundry moulding sands with gum arabic as binder added to sand in two phase schedules of bonding with acacia exudates added to mix in powdered form before mould compaction and acacia exudates in pre-solutionized form before mould compaction. Each

Nuhu Ali

343

Viscosity of locust bean, guar and xanthan gum solutions in the Newtonian domain: a critical examination of the log ( ? sp ) o -log c[ ?] o master curves  

Microsoft Academic Search

The viscosity in the low shear rate Newtonian domain of three biopolymers, locust bean gum, guar gum and xanthan gum was studied as a function of temperature and of polymer concentration in various aqueous solvents. The intrinsic viscosities [?]o of both galactomannans are not modified in the presence of 10 or 40% sucrose. In this case, a master curve relating

Bernard Launay; Grard Cuvelier; Salomon Martinez-Reyes

1997-01-01

344

Evaluation of the destructive effect of khaya gum on Bacillus subtilis spores during tableting.  

PubMed

The destructive effect of khaya gum used as a binding agent in a paracetamol formulation on Bacillus subtilis spores during tableting has been investigated, in comparison with the effects of two standard binders-polyvinylpyrrolidone and gelatin. The destructive effect of khaya gum was generally similar to those of the standard binders. Significant (p < 0.001 in each case) inverse linear relationships of log % survival of the B. subtilis spores with compression pressure and with concentration of binder, were established. The effect of the binding agent was significantly dependent (p < 0.001 in each case) on both compression pressure and the binder concentration. However, there was no significant interaction (p > 0.05) between the destructive effects of compression pressure and binder concentration. The results suggest that khaya gum and the standard binders would be useful in the destruction of microorganisms during tableting. PMID:10404534

Odeku, O A; Itiola, O A; Odelola, H A

1999-06-01

345

Effects of nicotine gum on psychomotor performance in smokers and non-smokers.  

PubMed

Two experiments were conducted to investigate the effects of nicotine on human performance. In the first study six smokers, who had been allowed to smoke normally prior to testing, completed a battery of psychometric tests (choice reaction time, memory scanning, tracking and flicker fusion threshold) at set points over 4 h after chewing 0, 2, or 4 mg nicotine polacrilex gum. A second study followed a similar design, but used five non-smoker volunteers who were required to chew only the 0 or 2 mg nicotine gum. Blood nicotine levels following the gum were measured in all subjects. The results indicate that additional nicotine improved both the speed and accuracy of motor activity among the smokers, but did not enhance central cognitive processes. No drug effects were found in the non-smoker study. PMID:2320715

Hindmarch, I; Kerr, J S; Sherwood, N

1990-01-01

346

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

2012-08-19

347

Glutamate transport and xanthan gum production in the plant pathogen Xanthomonas axonopodis pv. citri.  

PubMed

L-glutamate plays a central role in nitrogen metabolism in all living organisms. In the genus Xanthomonas, the nitrogen nutrition is an important factor involved in the xanthan gum production, an important exopolysaccharide with various industrial and biotechnological applications. In this report, we demonstrate that the use of L-glutamate by the phytopathogen Xanthomonas axonopodis pv. citri as a nitrogen source in defined medium significantly increases the production of xanthan gum. This increase is dependent on the L-glutamate concentration. In addition, we have also characterized a glutamate transport system that is dependent on a proton gradient and on ATP and is modulated by amino acids that are structurally related to glutamate. This is the first biochemical characterization of an energy substrate transport system observed in a bacterial phytopathogen with a broad economic and industrial impact due to xanthan gum production. PMID:23719672

Rojas, Robert; Nishidomi, Sabrina; Nepomuceno, Roberto; Oshiro, Elisa; de Cassia Caf Ferreira, Rita

2013-05-30

348

Effect of sucrose on the perceived flavor intensity of chewing gum.  

PubMed

The release of sucrose and menthone from chewing gum was measured in-mouth and in-nose, respectively, during eating. Swabs of saliva were taken from the tongue and analyzed using a rapid, direct liquid-mass spectrometry procedure. Menthone concentration in-nose was monitored on a breath-by-breath basis using direct gas phase atmospheric pressure chemical ionization-mass spectrometry. Simultaneously with the volatile release, trained panelists followed the change in mint flavor by time-intensity (TI) analysis. Two types of commercial chewing gum were analyzed. Both showed that the panelists perception of mint flavor followed sucrose release rather than menthone release. The temporal analysis of the chemical stimuli, with simultaneous TI analysis, provided unequivocal evidence of the perceptual interaction between nonvolatile and volatile flavor compounds from chewing gum. PMID:10552812

Davidson, J M; Linforth, R S; Hollowood, T A; Taylor, A J

1999-10-01

349

Homogeneous synthesis of hydroxypropyl guar gum in an ionic liquid 1-butyl-3-methylimidazolium chloride.  

PubMed

With potassium hydroxide (KOH) as catalyst, hydroxypropyl guar gum (HPG) was successfully prepared under homogenous conditions in an ionic liquid 1-butyl-3-methylimidazolium chloride (BmimCl). The value of degree of molar substitution (MS) of HPG, which was determined by means of (1)H NMR, was easily controlled by varying the mass ratio of propylene oxide (PO) to guar gum (GG). The distribution of hydroxypropyl moieties among the seven hydroxy groups in HPGs was investigated by NMR and the results indicated that the homogeneous reaction preferentially substituted at the C3?OH of the mannosyl residues in guar gum which was quite different from the heterogeneous reaction where substitution mostly occurred at C6?OH. The average number of hydroxypropyl units per OH substitution of HPGs with MS value of 0.20, 0.37 and 0.60 was 1.82, 1.42 and 1.76, respectively. PMID:23499112

Zhan, Zhensheng; Du, Bin; Peng, Shuhua; He, Jianping; Deng, Mingyu; Zhou, Jing; Wang, Ke

2012-12-12

350

Microwave-promoted hydrolysis of plant seed gums on alumina support.  

PubMed

Using a catalytic amount of potassium persulfate (1.48 x 10(-4)M), eight different seed gums were fully hydrolyzed on alumina support under microwave irradiation. The hydrolysis time varied between 1.33 and 2.33 min depending upon the seed gum structure. The used solid support could be easily separated from the hydrolyzates and recycled. However, under microwave field in an aqueous medium, the same amount of persulfate was unable to hydrolyze the seed gums. Solid-supported microwave hydrolysis has been compared with the microwave-enhanced aqueous hydrolysis (using K2S2O8 or 0.1N H2SO4) and also with the conventional hydrolysis procedures. PMID:16806127

Singh, Vandana; Tiwari, Ashutosh; Kumari, Premlata; Tiwari, Stuti

2006-06-27

351

Formulation and development of matrix tablets of tramadol using katira gum as release modifier.  

PubMed

The present study was aimed to study the drug release retardant property of katira gum in matrix tablets containing tramadol as a model drug. Katira gum was characterized in terms of pH, viscosity and swelling index. The tablets were evaluated for various physical tests viz. hardness, friability, tensile strength and drug content. In vitro dissolution studies were performed and different empirical models were applied to drug release data for evaluating the drug release mechanisms and kinetics. Owing to good swelling properties (swelling index 340% and 480% after 6 and 24 h hydration) of the gum, the n values (as computed from Korsmeyer-Peppas model) were found to be ranging between 0.453 to 0.710 indicating involvement of both polymeric hydration and relaxation in the diffusion of drug from the matrix tablet. PMID:20823680

Singh, Inderbir; Kumar, Pradeep; Kumar, Sanjeev; Rana, Vikas

2010-09-01

352

Oxidation and gum formation in diesel fuels. Interim technical report, May-December 1985  

SciTech Connect

This Report describes experiments on oxidation and gum formation from n-dodecane, tetralin, and several diesel fuels at 43, 60, and 100 C, with and without added initiators, t-butyl peroxide and 2,2'azobis(2-methylpropionitrile) (ABN). Experiments on gum determination and a manuscript for publication, Gum and Deposit Formation from Jet Turbine and Diesel Fuels at 100 C, are included. One objective of work on this Contract is to relate oxidations of diesel fuels at 100 and 130 C, where experiments can be performed in hours or days, to standard tests for fuel stability at ambient temperatures and 43.3 C (110 F), which require many weeks. A second objective is to devise a fast test for fuel stability.

Mayo, F.R.

1985-12-20

353

Xanthan Gum-a lyotropic, liquid crystalline polymer and its properties as a suspending agent  

SciTech Connect

Studies a variety of xanthan solutions of various polymer concentrations in the presence and absence of various salts under a polarized light microscope (100X) in order to test xanthan gum for liquid crystalline order. Xanthan gum, a polysaccharide used in drilling fluids and in tertiary recovery, has relatively stable viscosity properties as a function of salt concentration, pH, temperature, and shear degradation. With solutions from 2 to 10% (wt/vol) xanthan gum in distilled water at room temperature, birefringent, ordered domains were observed at 10% concentration, with a decrease in birefringence as the polymer concentration decreased. When the xanthan solution is sheared between a glass slide and a cover slip, the optic axis (chain direction) aligns using the shear direction (as determined by the colors displayed using a first-order red plate). Examines liquid crystalline behavior of other naturally occurring polymers.

Salamone, J.C.; Clough, S.B.; Jamison, D.E.; Reid, K.I.G.; Salamone, A.B.

1982-08-01

354

Paste, wrap, and shimmy: a regimen for the prevention of gum disease.  

PubMed

The body of evidence showing a possible correlation between gum infection and systemic diseases is well documented and growing. At the same time, the prevalence of gum infection is increasing in the general populace. Gum infection and disease are routinely seen in patients who adhere to regular dental hygiene regimens and see their dentists on a regular basis. One of the reasons typical daily dental care does not eradicate gum disease (gingivitis) is that the usual home care regimens do not attack a major underlying cause of gingivitis: the layer of biofilm in the sulcus surrounding the tooth's root. This biofilm harbors and protects the bacteria that cause gum disease and root decay. Research has shown that there are no "magic bullets" in the form of rinses, pills, or special tools that effectively destroy the bacteria and its protective calyx. Therefore, daily dental regimens must be changed until the absence of gum infection and inflammation becomes the standard of care. The Paste, Wrap, and Shimmy method is presented in a way that can be understood by all patients. It can be reproduced and used as a teaching supplement by the dental team. The method is conceptually simple and inexpensive, but not intuitive or easy. It must be coached and reinforced; however, if implemented, it can be very effective. The author's office has increased the length of new patient and recurring hygiene visits so that the method can be properly taught through repetitive practice and visual presentations. Prevention is not insurance-driven, so dentists most often provide it as a free service. The rewards are significant, however, and on initial exposure to this method, patients routinely ask: "Why haven't I been shown this before?" They will also have an expectation that the learning process will be repeated at each visit until they are free of infection. PMID:23302359

Jester, Craig W

355

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.

2011-01-01

356

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 UVVis 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.

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

2013-01-01

357

IgE antibodies specific for carbohydrates in a patient allergic to gum arabic (Acacia senegal).  

PubMed

The present study deals with the detailed investigation of the IgE antibody response of a gum arabic-allergic patient. The patient showed multiple serologic and skin test sensitizations to a range of pollen, other inhalants and foods, and bee venom, and to the recombinant allergens Bet v 1 and Bet v 2. Moreover, the patient's serum reacted strongly to gum-arabic extract. The NaIO4-treated and thus deglycosylated extract showed no binding to IgE. In contrast, removal of the protein backbone by basic hydrolysis did not deplete the IgE reactivity. Therefore, it is concluded that the gum arabic-specific IgE antibodies of this patient were mainly directed against the carbohydrate fraction of this material. In IgE-inhibition assays, cross-reactions occurred in the range of 60% between gum arabic and known immunogenic N-glycans containing alpha1-3-linked fucose. Since the inhibition graphs were not parallel and the inhibition was not complete with heterologue antigens, the cross-reacting epitopes of gum arabic appeared to be different from the latter well-known cross-reactive carbohydrate determinants (CCD). Inhibition may have been caused by a partial immunologic identity of the investigated carbohydrate moieties. A strong IgE response to the fucose-containing glycan from bromelain was measured in a glycan ELISA that utilizes purified glycopeptides at the solid phase. This response, which may explain the multiple sensitizations without clinical significance diagnosed in the patient, could originate from inhalation of pollen, which is known to contain similar glycans, or from occupational sensitization during work as a baker and confectioner. Since the gum-arabic protein showed only very weak participation in the IgE reactivity, the clinical symptoms of the patient caused by gum arabic may be attributed to carbohydrate epitopes. Due to the repetitive polysaccharide sequence of gum arabic, several epitopes for the cross-linking of IgE should exist. PMID:9860236

Ftisch, K; Fh, J; Wthrich, B; Altmann, F; Haustein, D; Vieths, S

1998-11-01

358

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

2010-09-21

359

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

360

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

PubMed Central

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) non-intervention controls, (b) advice plus booklet, and (c) advice plus booklet plus the offer of nicotine gum. Follow up was done after four months and one year. The results show a clear advantage for those offered the nicotine gum (p less than 0.001). After correction for those who refused or failed chemical validation and those who switched from cigarettes to a pipe or cigars, the proportions who were abstinent at four months and still abstinent at one year were 3.9%, 4.1%, and 8.8% in the three groups, respectively. These percentages are based on all cigarette smokers who attended the surgeries including those who did not wish to stop and those in the gum group who did not try the gum (47%). The effect of the offer and prescription of gum was to motivate more smokers to try to stop, to increase the success rate among those who tried, and to reduce the relapse rate of those who stopped. The self selected subgroup of 8% who used more than one box of 105 pieces of gum achieved a success rate of 24%. It would be feasible and effective for general practitioners to include the offer of nicotine gum and brief instructions on its use as part of a minimal intervention routine with all cigarette smokers. A general practitioner who adopts such a routine with similar success could expect to achieve about 35-40 long term ex-smokers a year and so save the lives of about 10 of them. If replicated by all general practitioners throughout the country the yield of ex-smokers would be about one million a year.

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

1983-01-01

361

Standard test method for existent gum in fuels by jet evaporation  

SciTech Connect

This method covers determination of the existent gum in motor gasoline and aircraft fuels at the time of test. Provisions are made for the determination of the unwashed gum content of motor gasoline. Summary of method: a measured quantity of fuel is evaporated under controlled conditions of temperature and flow of air or steam. For aviation gasoline and aircraft turbine fuel, the resulting residue is weighed and reported as milligrams per 100 mL. For motor gasoline, the residue is weighed before and after extracting with n-heptane and the results reported as milligrams per 100 mL.

Not Available

1980-01-01

362

Development and antibacterial activity of cashew gum-based silver nanoparticles.  

PubMed

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; Mendona, Ronaldo Z; Eiras, Carla; Dos S Soares, Maria Jos; Leite, Jos Roberto S A

2013-03-01

363

The Xanthomonas campestris gumDGene Required for Synthesis of Xanthan Gum Is Involved in Normal Pigmentation and Virulence in Causing Black Rot  

Microsoft Academic Search

A cloned 4.1-kbEcoRI fragment fromXanthomonas campestrispv.campestriswas previously shown to complement the non-mucoid mutant P22 and increase xanthan gum production after being transformed into the wild-type strain Xc17. The gene responsible for these effects was identified, sequenced, and shown to be thegumDgene which has previously been proposed to encode glucose transferase activity, an enzyme required for adding the first glucose residue

Fang-Li Chou; Huei-Chi Chou; Yen-Shin Lin; Bih-Ying Yang; Nien-Tsung Lin; Shu-Fen Weng; Yi-Hsiung Tseng

1997-01-01

364

Cardiovascular effect of nicotine chewing gum in healthy non-smokers.  

PubMed

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 whole blood nicotine levels were measured for 240 min in the supine position, under indirect body heating. 72% -96% of the nicotine was absorbed. Only heart rate showed a significant increase (10%-12%) during the study as compared to placebo. The mean peak nicotine level was 6.5 ng/ml, which occurred at 15-60 min and roughly coincided with the peak heart rate, and then levelled off to around 3 ng/l at 120-240 min. All subjects complained of nausea, dizziness or anxiety to varying degrees. It is concluded that if healthy non-smokers chew Nicorette gum 4 mg by mistake, they would probably suffer more from generally unpleasant symptoms than from any cardiovascular upset. PMID:7173300

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

1982-10-01

365

Fractionation, characterization and study of emulsifying properties of corn fiber gum  

Technology Transfer Automated Retrieval System (TEKTRAN)

Corn fiber gum has been fractionated by hydrophobic interaction chromatography on Amberlite XAD-1180 resin using ionic, acidic, basic and hydrophobic solvents of different polarity. Characterization, including determination of total carbohydrate, acidic sugar and protein content has been done for e...

366

Corn fiber gum and milk protein conjugates with improved emulsion stability  

Technology Transfer Automated Retrieval System (TEKTRAN)

Corn fiber gum (CFG), an alkaline hydrogen peroxide extract of the corn kernel milling by-product corn fiber was covalently conjugated with Beta-lactoglobulin (Beta-LG) and whey protein isolate (WPI). Covalent coupling of CFG to protein was achieved by dry heating reaction (Maillard-type) of CFG ...

367

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

368

Irritant potential of some constituents from oleo-gum-resin of Commiphora myrrha.  

PubMed

The irritant potentials of essential oil and seven sesquiterpenoids compounds newly isolated from the oleo-gum-resin of Commiphora myrrha were investigated by open mouse ear assay. The essential oil, curzerenone, furanodiene-6-one and furanoeudesma-1,3-diene showed potent and persistent irritant effects while others possess least irritant potentials. PMID:14693226

Saeed, M Asif; Sabir, A W

2004-01-01

369

Floral sexuality and breeding system in gum karaya tree, Sterculia urens  

Microsoft Academic Search

Comprehensive studies were carried out on phenology, floral sexuality, pollination biology, pollen-pistil interaction, breeding system and fruit and seed set on three populations of gum karaya tree ( Sterculia urens). The species is andromonoecious and produces a large number of male and a limited number of bisexual (functionally female) flowers. The numbers of male and bisexual flowers varies not only

V. G. Sunnichan; H. Y. Mohan Ram; K. R. Shivanna

2004-01-01

370

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

371

"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

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

2010-01-01

372

Effect of Regular Gum Chewing on Levels of Anxiety, Mood, and Fatigue in Healthy Young Adults  

PubMed Central

Introduction: The effect of regular gum chewing on psychological status is unknown. The purpose of this study was to examine the effect of gum chewing for fourteen days on psychological status and physical and mental fatigue in healthy young adults. Methods: We assigned 50 volunteers randomly to an intervention group (n = 26) and a control group (n = 24). Participants in the intervention group were requested to chew the gum twice per a day for fourteen days. The volunteers were required to complete a questionnaire related to lifestyle for baseline assessment. The State-Trait Anxiety Inventory (STAI), the Profile of Mood State (POMS), the World Health Organization Quality of Life 26, and assessment of physical and mental fatigue by visual analog scale were used at baseline, 2 weeks (after intervention), and 4 weeks (follow-up). Results: At 2 weeks, the score of state anxiety was significantly lower in the intervention group than the control group. The intervention participants scores of depression-dejection, fatigue and confusion in POMS were better than the control group scores. Mental fatigue were also relieved after the intervention. At 4 weeks, there were no significant differences between both groups. Conclusion: Fourteen days gum chewing may improve the levels of anxiety, mood and fatigue.

Sasaki-Otomaru, Akiyo; Sakuma, Yumiko; Mochizuki, Yoshiko; Ishida, Sadayo; Kanoya, Yuka; Sato, Chifumi

2011-01-01

373

Fomation of corn fiber gum-milk protein conjugates and their molecular characterization  

Technology Transfer Automated Retrieval System (TEKTRAN)

Corn fiber arabinoxylan is hemicellulose B isolated from the fibrous portions (pericarp, tip cap, and endosperm cell wall fractions) of corn kernels and is commonly referred to as corn fiber gum (CFG). Our previous studies showed that CFG isolated from corn bran (a byproduct of corn dry milling) co...

374

Stability and thermal conductivity enhancement of carbon nanotube nanofluid using gum arabic  

Microsoft Academic Search

This experimental study reports on the stability and thermal conductivity enhancement of carbon nanotubes (CNTs) nanofluids with and without gum arabic (GA). The stability of CNT in the presence of GA dispersant in water is systematically investigated by taking into account the combined effect of various parameters, such as sonication time, temperature, dispersant and particle concentration. The concentrations of CNT

W. Rashmi; A. F. Ismail; I. Sopyan; A. T. Jameel; F. Yusof; M. Khalid; N. M. Mubarak

2011-01-01

375

The water-soluble gumstheir botany, sources and utilization  

Microsoft Academic Search

Arabic, tragacanth, ghatti, karaya and other commercially valuable gums are exudations of a variety of trees and shrubs in\\u000a many parts of the world. Their hydrophilic and other properties render them useful in the adhesives, beverage, cosmetic, paint,\\u000a papermaking, pharmaceutical, textile and other industries.

C. L. Mantell

1949-01-01

376

Study of blend films from methacryloyl guar gum and sodium alginate  

Microsoft Academic Search

Films were prepared by the casting method using sodium alginate (SA) and methacryloyl guar gum (MAG) in different ratios. The concentration of SA ranged from 0% to 50% (v\\/v). Water vapor transmission rate and oxygen permeability of the films were investigated. Films were evaluated for mechanical and antibacterial properties. The water vapor transmission rate did not change significantly upon addition

Wenfa Xiao; Litao Dong

2011-01-01

377

Irritant potential of some constituents from oleo-gum-resin of Commiphora myrrha  

Microsoft Academic Search

The irritant potentials of essential oil and seven sesquiterpenoids compounds newly isolated from the oleo-gum-resin of Commiphora myrrha were investigated by open mouse ear assay. The essential oil, curzerenone, furanodiene-6-one and furanoeudesma-1,3-diene showed potent and persistent irritant effects while others possess least irritant potentials.

M. Asif Saeed; A. W. Sabir

2004-01-01

378

Ronidazole pharmacokinetics in cats following delivery of a delayed-release guar gum formulation.  

PubMed

Ronidazole (RDZ) is the only known effective treatment for feline diarrhea caused by Tritrichomonas foetus. This study aimed to develop guar gum-coated colon-targeted tablets of RDZ and to determine the pharmacokinetics of this delayed-release formulation in cats. Guar gum-coated tablets were administered orally once to five healthy cats (mean dose 32.3 mg/kg). The tablets were then administered once daily for 5 days to four cats (mean dose 34.5 mg/kg), and absorption studies repeated on day 5. Plasma was collected and analyzed for RDZ concentration, and pharmacokinetic noncompartmental and deconvolution analysis were performed on the data. There was negligible RDZ release until after 6 h, and a delayed peak plasma concentration (mean Cmax 28.9 ?g/mL) at approximately 14.5 h, which coincides with colonic arrival in cats. Maximum input rate (mg/kg per hour) occurred between 6 and 16 h. This delayed release of ronidazole from guar gum-coated tablets indicates that release of RDZ may be delayed to deliver the medication to a targeted area of the intestine. Repeated dosing with guar gum tablets to steady-state did not inhibit drug bioavailability or alter the pharmacokinetics. Such targeted RDZ drug delivery may provide improved efficacy and reduce adverse effects in cats. PMID:23106427

Papich, M G; Levine, D N; Gookin, J L; Davidson, G S; Stagner, W C; Hayes, R B

2012-10-30

379

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

380

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

381

Functional effects of xanthan gum on composite cassava-wheat dough and bread  

Microsoft Academic Search

The use of composite flour for bread making is gradually gaining prominence worldwide due to some economic and nutritional reasons. However, studies on the application of functional ingredients purposely to improve composite bread quality are very few. This paper examines the functional role of xanthan gum (XG) on the properties of dough and bread from composite cassava-wheat flour. The viscoelastic

Taofik A. Shittu; Rashidat A. Aminu; Evelyn O. Abulude

2009-01-01

382

Interfacial rheology of surface-active biopolymers: Acacia senegal gum versus hydrophobically modified starch.  

PubMed

Acacia gum is a hybrid polyelectrolyte containing both protein and polysaccharide subunits. We study the interfacial rheology of its adsorption layers at the oil/water interface and compare it with adsorbed layers of hydrophobically modified starch, which for economic and political reasons is often used as a substitute for Acacia gum in technological applications. Both the shear and the dilatational rheological responses of the interfaces are considered. In dilatational experiments, the viscoelastic response of the starch derivative is just slightly weaker than that for Acacia gum, whereas we found pronounced differences in shear flow: The interfaces covered with the plant gum flow like a rigid, solidlike material with large storage moduli and a linear viscoelastic regime limited to small shear deformations, above which we observe apparent yielding behavior. In contrast, the films formed by hydrophobically modified starch are predominantly viscous, and the shear moduli are only weakly dependent on the deformation. Concerning their most important technological use as emulsion stabilizers, the dynamic interfacial responses imply not only distinct interfacial dynamics but also different stabilizing mechanisms for these two biopolymers. PMID:17949102

Erni, Philipp; Windhab, Erich J; Gunde, Rok; Graber, Muriel; Pfister, Bruno; Parker, Alan; Fischer, Peter

2007-10-20

383

An Approach to Combining Results From Multiple Methods Motivated by the ISO GUM  

Microsoft Academic Search

The problem of determining a consensus value and its uncertainty from the results of multiple methods or laboratories is dis- cussed. Desirable criteria of a solution are presented. A solution motivated by the ISO Guide to the Expression of Uncer- tainty in Measurement (ISO GUM) is intro- duced and applied in a detailed worked example. A Bayesian hierarchical model motivated

M. S. Levenson; K. R. Eberhardt; L. M. Gill; W. F. Guthrie; H. K. Liu; M. G. Vangel; J. H. Yen; N. F. Zhang

2000-01-01

384

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 90.922.34%, cumulative drug release of 41.653.97% 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

2012-12-20

385

Mood Management and Nicotine Gum in Smoking Treatment: A Therapeutic Contact and Placebo-Controlled Study  

Microsoft Academic Search

Earlier research indicated that a 10-session mood management (MM) intervention was more effective than a 5-session standard intervention for smokers with a history of major depressive disorder (MDD). In a 2 2 factorial design, the present study compared MM intervention to a contact-equivalent health education intervention (HE) and 2 mg to 0 mg of nicotine gum for smokers with

Sharon M. Hall; Ricardo F. Muoz; Victor I. Reus; Karen L. Sees; Carol Duncan; Gary L. Humfleet; Diane T. Hartz

1996-01-01

386

Effect of xylitol chewing gum on salivary Streptococcus mutans in preschool children.  

PubMed

Dental caries remains a significant problem for poor children in the United States. One strategy for treating dental caries is to suppress streptococcus mutans, the chief pathogen responsible for the disease. The purpose of this study was to evaluate the effect of xylitol gum in salivary S. mutans levels in preschool children. Sixty-one children were randomly assigned into the xylitol group and the control group. The xylitol group chewed gum sweetened only with xylitol (XyliFresh100%, Hershey Food Corporation, U.S.A.) three times a day for three weeks. S. mutans counts were tested using the Dentocult-SM Strip Mutans-test (Orion Diagnostica, Finland) at baseline and after three weeks. The shift from higher S. mutans scores to lower was greater in the xylitol group than in the control group (p;lt0.05). This study supports the suggestion that chewing xylitol gum may reduce salivary S. mutans levels. Xylitol chewing gum may provide a feasible caries prevention method for preschool children. PMID:12119821

Autio, Jaana T

387

Isolation, purification and identification of protein associated with corn fiber gum  

Technology Transfer Automated Retrieval System (TEKTRAN)

Corn fiber gum (CFG), an alkaline hydrogen peroxide extract of corn kernel milling by-product corn fiber is a proteinaceous arabinoxylan with a protein content ranging from ca. 2 to 9% by weight for the CFG samples isolated from different corn milling fiber sources. Several studies have suggested...

388

In Vitro and In Vivo Activities of Chios Mastic Gum Extracts and Constituents against Helicobacter pylori  

Microsoft Academic Search

The extracts and pure major constituents of Chios mastic gum (resin of Pistacia lentiscus var. chia) were tested for their activities against Helicobacter pylori. A total mastic extract without polymer (TMEWP) was prepared after removal of the contained insoluble polymer in order to ameliorate solubility and enhance in vivo activity. Administration of TMEWP to H. pylori SS1-infected mice over the

Sotirios Paraschos; Prokopios Magiatis; Sofia Mitakou; Kalliopi Petraki; Antonios Kalliaropoulos; Petros Maragkoudakis; Andreas Mentis; Dionyssios Sgouras; Alexios-Leandros Skaltsounis

2007-01-01

389

GUM AND PROTEIN ENRICHMENT FROM SICKLEPOD (CASSIA OBTUSIFOLIA) SEED BY FINE GRINDING AND SIEVING  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sicklepod (Cassia obtusifolia) is a weed species that has contaminated soybean and other crops. Although sicklepod continues to be a problem weed, the advent of herbicide-resistant soybeans has reduced the problem somewhat in the last few years. Sicklepod seed contains a gum of commercial interest...

390

Two-colour chewing gum mixing ability: digitalisation and spatial heterogeneity analysis.  

PubMed

Many techniques are available to assess masticatory performance, but not all are appropriate for every population. A proxy suitable for elderly persons suffering from dementia was lacking, and a two-colour chewing gum mixing ability test was investigated for this purpose. A fully automated digital analysis algorithm was applied to a mixing ability test using two-coloured gum samples in a stepwise increased number of chewing cycles protocol (Experiment 1: n=14; seven men, 19-63years), a test-retest assessment (Experiment 2: n=10; four men, 20-49years) and compared to an established wax cubes mixing ability test (Experiment 3: n=13; 0 men, 21-31years). Data were analysed with repeated measures anova (Experiment 1), the calculation of the intraclass correlation coefficient (ICC; Experiment 2) and Spearman's rho correlation coefficient (Experiment 3). The method was sensitive to increasing numbers of chewing cycles (F5,65 =57270, P=0000) and reliable in the test-retest (ICC value of 0714, P=0004). There was no significant correlation between the two-coloured gum test and the wax cubes test. The two-coloured gum mixing ability test was able to adequately assess masticatory function and is recommended for use in a population of elderly persons with dementia. PMID:23927753

Weijenberg, R A F; Scherder, E J A; Visscher, C M; Gorissen, T; Yoshida, E; Lobbezoo, F

2013-08-09

391

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

392

Reduction of the viscosity of solutions viscosified with xanthan gum polymers  

SciTech Connect

This patent describes a process for reducing the viscosity of a drilling fluid containing Xanthan gum polymer solution. It comprises: contacting the drilling fluid with hydrogen peroxide and adjusting the pH of the solution to a level of at least about between 8 and 10.

Bridges, K.L.; Kalinski, K.L.

1991-10-08

393

Importance of protein rich components in the emulsifying properties of corn fiber gum  

Technology Transfer Automated Retrieval System (TEKTRAN)

Purified corn fiber gum (CFG-F) isolated from "fine" (kernel endosperm-derived) corn fiber that contained about 2% residual protein was extracted with 70% aqueous ethanol. The aqueous ethanol extract (AEE), which contained 19.5% of the total CFG, contained a high percentage of the proteinaceous ma...

394

The Effect of a Sodium Trimetaphosphate Chewing Gum on Dental Caries.  

National Technical Information Service (NTIS)

Sodium trimetaphosphate added to chewing gum has been shown to be of marginal value in reducing dental caries on the proximal surfaces of permanent teeth. This phosphate may have application as a food or drink additive as an adjunct in the total quest for...

S. B. Finn B. B. Keele R. Frew

1976-01-01

395

Molecular mobility in ultrasonically treated butyl gum and devulcanized butyl rubber  

Microsoft Academic Search

In an effort to improve our understanding of the structural changes during ultrasonic treatment, proton NMR transverse relaxation was used to study butyl rubber gum before and after ultrasonic treatment, and ultrasonically devulcanized unfilled butyl rubber. The relaxation decay was successfully described using a two-component model. The short component is attributed to entangled and crosslinked networks including the high molecular

Wenlai Feng; A. I. Isayev; E. von Meerwall

2004-01-01

396

Identification of Albizia gum exudates which are not permitted food additives  

Microsoft Academic Search

Trees of the genus Albizia have frequently been confused with Acacia species. The genus Albizia has been recommended for more extensive arid zone development; its species are sources of tannins and gum exudates, which are not included in any of the regulatory lists of permitted food additives. Analytical data permitting their identification are therefore required to allow food law compliance

D. M. W. Anderson; N. A. Morrison

1990-01-01

397

Chewing Sugar-Free Gum Reduces Ileus After Cesarean Section in Nulliparous Women: A Randomized Clinical Trial  

PubMed Central

Background Gum chewing after cesarean section may stimulate bowel motility and decrease duration of postoperative ileus. Objectives The current study assessed the effect of chewing sugar-free gum on the return of bowel function, where cesarean section had been performed in nulliparous women. Materials and Methods In a randomized clinical trial, 60 patients, scheduled for cesarean section were randomly divided in to 2 groups gum-chewing group (n = 30) and control group (n = 30) postoperatively. The patients in the gum-chewing group postoperatively chewed sugar free gum 3 times daily each time for 1 hour until discharge. The patients' demographic characteristics, duration of surgery, mean hunger time, flatus and bowel motility were compared in the two groups. Results There was no significant difference between the 2 groups regarding patient demographics, intraoperative, and postoperative care. In the gum-chewing and the control group there was a significant difference in the mean postoperative interval of the first bowel movement (20.89 8.8 versus 27.93 9.3 hours, P = 0.004), the first feeling of hunger (10.37 6.0 versus 16.33 9.3 hours, P = 0.005), the first passage of flatus (25.02 5.8 versus 31.08 9.7 hours, P = 0.003), and the first defecation (31.17 5.3versus 40.08 8.8 hours, P = 0.000) respectively, which were significantly shorter in the gum-chewing group compared to those of the control group. There were no major complications in either group. All patients in the gum-chewing group tolerated it without any major complications and side effects. Conclusions The study results demonstrated that bowel motility after cesarean section in nulliparous women can be accelerated by gum chewing which is a useful, inexpensive and well-tolerated method for mothers in post-cesarean section.

Mohsenzadeh Ledari, Farideh; Barat, Shanaz; Delavar, Mouloud Agajani; Banihosini, Seyed Zahra; Khafri, Soriya

2013-01-01

398

Rate and yield relationships in the production of xanthan gum by batch fermentations using complex and chemically defined growth media  

SciTech Connect

Rate and yield information relating to biomass and product formation and to nitrogen, glucose and oxygen consumption are described for xanthan gum batch fermentations in which both chemically defined (glutamate nitrogen) and complex (peptone nitrogen) media are employed. Simple growth and product models are used for data interpretation. For both nitrogen sources, rate and yield parameter estimates are shown to be independent of initial nitrogen concentrations. For stationary phases, specific rates of gum production are shown to be independent of nitrogen source but dependent on initial nitrogen concentration. The latter is modeled empirically and suggests caution in applying simple product models to xanthan gum fermentations. 13 references.

Pinches, A.; Pallent, L.J.

1986-10-01

399

Steady and dynamic shear rheological properties of gum-based food thickeners used for diet modification of patients with dysphagia: effect of concentration.  

PubMed

Gum-based food thickeners are widely used for diet modification for patients with dysphagia in Korea. In this study, the rheological properties of two commercially available gum-based food thickeners (xanthan gum and xanthan-guar gum mixture) marketed in Korea were determined as a function of concentration. The steady and dynamic shear rheological properties of the food thickeners in water were investigated at five different concentrations (1.0%, 1.5%, 2.0%, 2.5%, and 3.0% w/w). Both food thickeners showed high shear-thinning fluid characteristics (n=0.14-0.19) at all concentrations (1.0-3.0%). In general, the thickener with the xanthan-guar gum mixture showed higher values for steady shear viscosity compared to that with xanthan alone, whereas it showed lower dynamic rheological parameter values. Steady and dynamic rheological parameters demonstrated differences in rheological behaviors between the gum-based food thickeners, indicating that their rheological properties are related to the type of gum and gum concentration. In particular, the type of gum played a role in the time-dependent flow properties of the gum-based food thickeners. Appropriately selecting a commercial food thickener appears to be of great importance for dysphagia therapists and patients. PMID:23179025

Seo, Chan-Won; Yoo, Byoungseung

2012-11-24

400

Comparative evaluation of the binding properties of two species of Khaya gum polymer in a paracetamol tablet formulation.  

PubMed

A study was made of the comparative effects of polymers obtained from two species of khaya tree - Khaya senegalensis and Khaya grandifoliola - as binding agents in a paracetamol tablet formulation. The mechanical properties of the tablets were assessed using the tensile strength (T), brittle fracture index (BFI) and friability (F) of the tablets while the drug release properties of the tablets were assessed using disintegration and dissolution times. The tensile strength, disintegration and the dissolution times of tablets increased with the increase in binder concentration while F and BFI decreased. K. senegalensis gum produced tablets with stronger mechanical properties with less tendency to laminate, and longer disintegration and dissolution times than K. grandifoliola gum. The results suggest that the polymer gum from K. senegalensis will be more appropriate as a binding agent than the gum from K. grandifoliola when higher mechanical strength and slower release profiles of tablets are desired. PMID:18720239

Adenuga, Yedunni A; Odeku, Oluwatoyin A; Adegboye, Temidayo A; Itiola, Oludele A

2008-01-01

401

Investigation and record of the apricot trees' gums raw resources of flora of the Republic of Armenia.  

PubMed

Considering the fact that the recent resourceological researches referring to the local flora apricot trees' gums held in different regions of the RA were encountered in 1999-2000, there was a problem of serious approach necessity regarding gums in the RA (for a process of their resources record in the RA), as their need increase is anticipated not just in the medical industry, but also in the other industrial aspects. According to the got value, the possible annual provision volume all over the Republic made up 49.52-55.69 tons. Meanwhile raw productivity is approximately 53.6 6.67 g/m(2). Thus, the gums' raw sources provided by the widely-cultivating in the RA apricot gum-trees can fully meet the needs of those industrial aspects, where use of the polysaccharides of natural origin is inevitable. PMID:22201092

Chichoyan, N

2011-11-01

402

Predictors of Adherence to Nicotine Gum and Counseling among African-American Light Smokers  

PubMed Central

BACKGROUND A high proportion of African-American smokers are light smokers, and they experience low smoking cessation rates and disproportionately high tobacco-related morbidity; yet no studies have examined tobacco treatment adherence in this group. OBJECTIVES To determine the predictors of adherence to nicotine gum and counseling among African-American light smokers (defined as smoking ?10 cigarettes/day), and the effects of adherence on smoking cessation. DESIGN Data were from a 2??2 randomized, placebo-controlled smoking cessation trial of nicotine gum (2mg versus placebo) and counseling (motivational interviewing versus health education). PARTICIPANTS Seven hundred fifty-five African-American light smokers at a community-based clinic. MEASUREMENTS Demographic and health-related information, smoking behaviors, psychosocial variables, adherence to nicotine gum and counseling, and cotinine-verified 7-day abstinence from smoking at week-26 follow-up. RESULTS A logistic regression model showed that having a higher body mass index (OR?=?1.03, 95% CI?=?1.01 to 1.05), more quit attempts in the past year (OR?=?1.04, 95% CI?=?1.01 to 1.07), higher baseline exhaled carbon monoxide (OR?=?1.22, 95% CI?=?1.01 to 1.48), and higher perceived stress (OR?=?1.12, 95% CI?=?1.03 to 1.22) increased the likelihood of adherence to nicotine gum. Being a high school graduate was a predictor of adherence to counseling (OR?=?1.58, 95% CI?=?1.02 to 2.44). Surprisingly, being adherent to nicotine gum significantly reduced the odds of smoking cessation (OR?=?0.50, CI?=?0.28 to 0.87). On the other hand, adherence to counseling dramatically increased the likelihood of smoking cessation (OR?=?3.32, CI?=?1.36 to 8.08). CONCLUSIONS Individual risk factors may influence adherence to nicotine gum and counseling. Improving psychological interventions and promoting adherence to counseling may increase overall smoking cessation success among African-American light smokers.

Zheng, Hui; Guo, Hongfei; Ahluwalia, Jasjit S.

2010-01-01

403

Traditional uses, phytochemistry and pharmacology of asafoetida ( Ferula assa-foetida oleo-gum-resin)A review  

Microsoft Academic Search

The old traditional phytomedicine asafoetida, an oleo-gum-resin obtained from the roots of different Ferula assa-foetida, is used in different countries for various purposes. Asafoetida is not only used as a culinary spice but also traditionally used to treat various diseases, including asthma, gastrointestinal disorders, intestinal parasites, etc. This oleo-gum-resin has been known to possess antifungal, anti-diabetic, anti-inflammatory, anti-mutagenic and antiviral

Milad Iranshahy; Mehrdad Iranshahi

2011-01-01

404

Sensitization due to Gum Arabic (Acacia senegal): The Cause of Occupational Allergic Asthma or Crossreaction to Carbohydrates?  

Microsoft Academic Search

Background: A pharmaceutical industry worker was exposed to dust of gum arabic in the tablet coating plant and complained of work-related shortness of breath, chest tightness, runny nose, itching and redness of the eyes. This case was investigated for allergy to gum arabic and compared with a control group. The aim of the study was to identify the IgE-binding components

Ingrid Sander; Monika Raulf-Heimsoth; Kai Wiemer; Sabine Kespohl; Thomas Brning; Rolf Merget

2006-01-01

405

Three-layer guar gum matrix tablet formulations for oral controlled delivery of highly soluble trimetazidine dihydrochloride  

Microsoft Academic Search

The present study is carried out to design oral controlled drug delivery systems for highly water-soluble drugs using guar gum as a carrier in the form of three-layer matrix tablets. Trimetazidine dihydrochloride was chosen as a model drug because of its high water solubility. Matrix tablet granules containing 30% (M1), 40% (M2) or 50% (M3) of guar gum were prepared

Y. S. R. Krishnaiah; R. S. Karthikeyan; V. Gouri Sankar; V. Satyanarayana

2002-01-01

406

Gum chewing inhibits the sensory processing and the propagation of stress-related information in a brain network.  

PubMed

Stress is prevalent in human life and threatens both physical and mental health; stress coping is thus of adaptive value for individual's survival and well-being. Although there has been extensive research on how the neural and physiological systems respond to stressful stimulation, relatively little is known about how the brain dynamically copes with stress evoked by this stimulation. Here we investigated how stress is relieved by a popular coping behavior, namely, gum chewing. In an fMRI study, we used loud noise as an acute stressor and asked participants to rate their feeling of stress in gum-chewing and no-chewing conditions. The participants generally felt more stressful when hearing noise, but less so when they were simultaneously chewing gum. The bilateral superior temporal sulcus (STS) and the left anterior insula (AI) were activated by noise, and their activations showed a positive correlation with the self-reported feeling of stress. Critically, gum chewing significantly reduced the noise-induced activation in these areas. Psychophysiological interaction (PPI) analysis showed that the functional connectivity between the left AI and the dorsal anterior cingulate cortex (dACC) was increased by noise to a lesser extent when the participants were chewing gum than when not chewing gum. Dynamic causality modeling (DCM) demonstrated that gum chewing inhibited the connectivity from the STS to the left AI. These findings demonstrate that gum chewing relieves stress by attenuating the sensory processing of external stressor and by inhibiting the propagation of stress-related information in the brain stress network. PMID:23573184

Yu, Hongbo; Chen, Xi; Liu, Jinting; Zhou, Xiaolin

2013-04-03

407

Potentials of Gum From Detarium microcarpum (DM) and Mucuna flagellipes (MF) Seeds as Raw Beef Burger Stabilizers  

Microsoft Academic Search

Raw beef burgers containing graded levels (0.25, 0.5, 0.75, and 1.0%) of polysaccharide gums extracted from Detarium microcarpum (DM) and Mucuna flagellipes (MF) were produced. Unstabilized beef burgers and beef burgers containing gum tragacanth (TR) were also produced simultaneously to serve as control. The raw beef burgers were evaluated for selected physicochemical and sensory properties so as to assess the

J. C. Onweluzo; Z. A. Obanu; M. C. Okwandu

2004-01-01

408

Chewing gum moderates multi-task induced shifts in stress, mood, and alertness. A re-examination.  

PubMed

The finding that chewing gum can moderate stress and mood changes following a multi-task cognitive stressor (Scholey et al., 2009) was re-examined. In a repeated measures cross-over design, thirty participants completed a 20-min multi-tasking stressor on consecutive days, both with and without chewing gum. Both prior to and post stressor, participants provided salivary cortisol samples and self-rated measures of stress, state anxiety, calmness, contentedness, and alertness. Contrary to Scholey et al. (2009), chewing gum failed to attenuate both salivary cortisol levels and the increase in self-rated stress. Self-rated anxiety, calmness, and contentedness were not impacted by chewing gum. This suggests that the stress effects reported by Scholey et al. may be constrained by particular features of that study (e.g. morning testing). However, consistent with Scholey et al. (2009), chewing gum was shown to increase alertness following the stressor. The mechanisms underpinning heightened alertness are unclear; however, such increases may be linked to greater cerebral activity following the chewing of gum (Fang Li, Lu, Gong, & Yew, 2005). PMID:21232569

Johnson, Andrew J; Jenks, Rebecca; Miles, Christopher; Albert, Michael; Cox, Martin

2011-01-11

409

Note. Influence of texture and type of hydrocolloid on perception of basic tastes in carrageenan and gellan gels Nota. Influencia de la textura y del tipo de hidrocoloide en la percepcin de los gustos fundamentales en geles de carragenato y de gelana  

Microsoft Academic Search

Preliminary work was carried out on the effect of texture, as represented by gel strength, between around 5 and 20 N of compression maximum force, of both carrageenan and gellan gels on the per ception of the four basic tastes. These were produced by addition of 15% (w\\/w) sucrose, 0.06%(w\\/w) caffeine, 0.5% (w\\/w) sodium chloride, or a mixture of 0.15%

E. Costell; M. Peyroln; L. Durn

2000-01-01

410

Gum and deposit formation from jet turbine and diesel fuels at 100/sup 0/C  

SciTech Connect

Rates of oxidation and gum formation for six hydrocarbons, three jet turbine fuels and three diesel fuels have been measured at 100/sup 0/C in the presence of t-Bu/sub 2/O/sub 2/ as initiator. Four of the six fuels oxidize faster at 100/sup 0/C than in previous work at 130/sup 0/C without initiator. For any single substrate, the amount of gum produced for the oxygen absorbed is similar at 100 and 130/sup 0/C, even with large changes in rates and t-Bu/sub 2/O/sub 2/ concentrations. In general, the pure hydrocarbons have long kinetic chains and give good yields of hydroperoxides.

Mayo, F.R.; Lan, B.Y.

1987-02-01

411

Gamma scintigraphic studies on guar gum matrix tablets for colonic drug delivery in healthy human volunteers  

Microsoft Academic Search

A novel colon-specific drug delivery system based on a polysaccharide, guar gum, was evaluated by conducting gamma scintigraphic studies using technetium-99m-DTPA as tracer, in six healthy male human volunteers. Scintigraphs taken at regular intervals have shown that some amount of tracer present on the surface of the tablets was released in stomach and small intestine and the bulk of the

Y. S. R Krishnaiah; S Satyanarayana; Y. V Rama Prasad; S Narasimha Rao

1998-01-01

412

Effects onWholeSaliva ofChewingGums Containing Calcium Phosphates  

Microsoft Academic Search

Toevaluate chewing gumsasavehicle toincrease salivary mineral saturation levels andenhance salivation, monocalcium phosphate monohydrate (MCPM)andan equimolar mixture oftetracalcium phosphate (TTCP) with dicalcium phosphate anhydrous (DCPA) werechosen asex- perimental chewing gumadditives. Eachofeight subjects chewed acommercial sugarless bubble gum(control) for16 minorthesamegumtowhich 5wt%ofMCPMortheTTCP- DCPAmixture hadbeen added. Thesaliva samples collected every 2minwereanalyzed forweight, pH,andtotal calcium (Ca) andphosphate (P) concentrations. Bothexperimental gumswerefound toincrease significantly theCaandPcon- centrations

L. C. Chow; S. Takagi; T. H. Chow; K. K. Takagi; A. Sieck

413

Xylitol Concentrations in the Saliva of Children After Chewing Xylitol Gum or Consuming a Xylitol Mixture  

Microsoft Academic Search

. Xylitol prevents otitis media when given to children regularly five times per day. To find a more convenient dosing schedule,\\u000a an enzymatic assay was used to measure xylitol concentrations in the saliva of 65 children after giving them xylitol chewing\\u000a gum or syrup in doses equal to those used in clinical trials. Although concentrations high enough to have an

T. Tapiainen; M. Renko; T. Kontiokari; M. Uhari

2002-01-01

414

Determination of Nicotine Absorption from Multiple Tobacco Products and Nicotine Gum  

PubMed Central

Introduction: Snus is a smokeless tobacco product traditionally used in Scandinavia and available in pouched or loose forms. The objective of this study was to determine nicotine absorption for current pouched and loose snus products in comparison with a cigarette and an over-the-counter nicotine gum. Methods: We conducted an open-label, randomized, 6-way, crossover study involving 20 healthy snus and cigarette users. One of 6 products (2 pouched snus, 2 weights of loose snus, a cigarette, and a nicotine gum) was administered at each of 6 visits. Blood samples were taken at intervals over 120 min and sensory perception assessed by questionnaire. Results: For the 4 smokeless tobacco products and the nicotine gum, blood plasma levels of nicotine were ranked according to total nicotine content as follows: loose snus (27.1 mg nicotine) > pouched snus (14.7 mg nicotine) > loose snus (10.8 mg nicotine) = pouched snus (10.7 mg nicotine) > nicotine gum (4.2 mg nicotine). The area under the plasma concentrationtime curve (AUC) and maximum plasma concentration (Cmax) of nicotine ranged from 26.9 to 13.1 ng.h/ml and 17.9 to 9.1 ng.h/ml, respectively across all the products. Nicotine was absorbed more rapidly from the cigarette but systemic exposure was within the range of the smokeless tobacco products (AUC = 14.8 ng.h/ml; Cmax = 12.8 ng.h/ml). Conclusions: This study has generated new information on comparative nicotine absorption from a cigarette, loose snus, and pouched snus typical of products sold in Scandinavia. The similar nicotine absorption for 1 g portions of loose and pouched snus with approximately 11 mg of nicotine indicate that absorption kinetics were dependent on quantity of tobacco by weight and total nicotine content rather than product form.

Digard, Helena; Proctor, Christopher; Kulasekaran, Anuradha; Malmqvist, Ulf

2013-01-01

415

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. Sllsten; J. Thorn; L. Barregrd; A. Schtz; G. Skarping

1996-01-01

416

Rheological properties of extracted malva nut gum ( Scaphium scaphigerum) in different conditions of solvent  

Microsoft Academic Search

Mucilage of malva nut fruit has been used as traditional medicine in Thailand. Health benefits of this mucilage are linked to its gelling property. This research was aimed to evaluate oscillatory rheological properties of malva nut gum (MNG) in different conditions of solvent (pH, ionic strength, and co-solutes addition). A small strain oscillation (0.1% strain) was used to investigate gelling

Anchalee Srichamroen; Visith Chavasit

2011-01-01

417

Rheological behaviour of spray-dried egg yolk\\/xanthan gum aqueous dispersions  

Microsoft Academic Search

This paper provides information on the microstructure of, and reports particle size distributions and rheological results\\u000a for, aqueous dispersions of spray-dried egg yolk and xanthan gum prepared on a laboratory scale using two types of homogenisers.\\u000a Laser light scattering results demonstrated that higher energy input during homogenisation yielded a dispersion with a lower\\u000a average particle size and a wider polydispersity,

Jose Muoz; Nicholas E. Hudson; Genovera Vlez; Maria Carmen Alfaro; James Ferguson

2001-01-01

418

CONTROL OF PIERCE'S DISEASE THROUGH DEGRADATION OF XANTHAN GUM Project Leader  

Microsoft Academic Search

Acinetobacter johnsonii GX123, a Xylella gum-degrading endophyte was co-inoculated with Xylella fastidiosa strain Texas in oleander plants to determine its efficacy as a biocontrol agent in preliminary experiments. Symptoms appeared in both plants inoculated with X. fastidiosa alone and plants co-inoculated with the endophyte. However, symptoms were more severe and appeared earlier in plants inoculated with X. fastidiosa than in

Donald A. Cooksey; Neal L. Schiller; Rosina Bianco; Seung-Don Lee; Korsi Dumenyo

419

Development of a peptide-containing chewing gum as a sustained release antiplaque antimicrobial delivery system  

Microsoft Academic Search

The objective of this study was to characterize the stability of KSL-W, an antimicrobial decapeptide shown to inhibit the\\u000a growth of oral bacterial strains associated with caries development and plaque formation, and its potential as an antiplaque\\u000a agent in a chewing gum formulation. KSL-W formulations with or without the commercial antibacterial agent cetylpyridinium\\u000a chloride (CPC) were prepared. The release of

Jabar A. Faraj; Rossella Dorati; Aurlie Schoubben; David Worthen; Francesca Selmin; Yilmaz Capan; Kai Leung; Patrick P. DeLuca

2007-01-01

420

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

421

Structural features of a water soluble gum polysaccharide from Murraya paniculata fruits  

Microsoft Academic Search

A water soluble gum polysaccharide was isolated from Murraya paniculata fruits. Hydrolytic experiments, methylation analysis, periodate oxidation studies and NMR data revealed that the polysaccharide was extensively branched and it consisted of 1,3-, and 1,3,6-linked ?-d-galactopyranosyl units, terminal ?-d-galactopyranosyl units and terminal ?-d-glucopyranosyl 1,4-?-d-galactopyranosyl units. Small amounts of 4-O-methylglucuronic acid residues were also present.

Saroj K Mondal; Bimalendu Ray; Pradyot K Ghosal; Anita Teleman; Tapani Vuorinen

2001-01-01

422

Structural features of a water soluble gum polysaccharide from Murraya paniculata fruits.  

PubMed

A water soluble gum polysaccharide was isolated from Murraya paniculata fruits. Hydrolytic experiments, methylation analysis, periodate oxidation studies and NMR data revealed that the polysaccharide was extensively branched and it consisted of 1,3-, and 1,3,6-linked beta-D-galactopyranosyl units, terminal beta-D-galactopyranosyl units and terminal alpha-D-glucopyranosyl 1,4-beta-D-galactopyranosyl units. Small amounts of 4-O-methylglucuronic acid residues were also present. PMID:11589969

Mondal, S K; Ray, B; Ghosal, P K; Teleman, A; Vuorinen, T

2001-10-22

423

Task-induced activation and hemispheric dominance in cerebral circulation during gum chewing  

Microsoft Academic Search

In elderly persons, it is thought that maintenance of masticatory function may have a beneficial effect on maintenance of\\u000a cerebral function. However, few studies on cerebral circulation during mastication exist. This study aimed to verify a possible\\u000a increase in cerebral circulation and the presence of cerebral hemispheric dominance during gum chewing. Twelve healthy, young\\u000a right-handed subjects with normal dentition were

Takahiro Ono; Yoko Hasegawa; Kazuhiro Hori; Takashi Nokubi; Toshimitsu Hamasaki

2007-01-01

424

Evaluation of satiety enhancement, including compensation, by blends of gum arabic. A methodological approach.  

PubMed

In the present study a potential satiating effect by two blends of gum arabic (EmulGold() (EG) and PreVitae() (PV)) was investigated in healthy humans applying a regression analysis on the change of values throughout the interval of the study. Two studies were thus conducted: a feasibility study using doses between 10 and 40 g and a dose-finding study of 5 or 10 g of only EG. The gums were dissolved in 250 ml of water (negative control). In both studies energy intake was determined 3 h after consumption, while Visual Analogue Scale (VAS) scores were recorded every 30 min from the time of consumption onwards. At doses of 40 g both EG and PV yielded a significant reduction in energy intake of more than 100 and 200 kcal, respectively. At doses of 10 or 20 g the reduction in energy intake amounted to more than 100 kcal for both. The second study demonstrated a significant reduction in caloric intake of more than 60 kcal at doses of 5 and 10 g of EG. With respect to the subjective perception of satiety, VAS scores revealed a significant increase as compared to the negative control of all doses of both gums. The regression analysis was sensitive in identifying not only the intensity of the perception during the time interval of the study but also the change in this intensity over time. The results of this study show that both blends of gum arabic are able to decrease the caloric intake significantly 3 h after consumption, and increase subjective ratings of feeling satiated, and could therefore be used in a dietary approach to control body weight development. PMID:21683750

Calame, Wim; Thomassen, Frans; Hull, Sarah; Viebke, Christer; Siemensma, Andr D

2011-06-12

425

Mastic gum has no effect on Helicobacter pylori load in vivo  

Microsoft Academic Search

Objective: To determine whether mastic gum suppresses or eradicates Helicobacter pylori infection in humans. Patients and methods: Nine patients with H. pylori infection, and without gastroduodenal ulceration, were recruited from day-case endoscopy lists and treated with mastic 1 g four times daily for 14 days. (13C)Urea breath tests (UBTs) were carried out immediately before, on day 15 and 5 weeks

James R. Bebb; Nathalie Bailey-Flitter; Dlawer Ala' Aldeen; John C. Atherton

426

Polysaccharide-based nanoparticles formation by polyeletrolyte complexation of carboxymethylated cashew gum and chitosan  

Microsoft Academic Search

Polyelectrolyte complex nanoparticles of chitosan and carboxymethyl cashew gum (CMCG) were prepared with CMCG with two different\\u000a degrees of substitution (DS=0.16 and 0.36). The effects of polymer concentration, molar mixing ratio (n\\u000a +\\/n\\u000a ?) and mixing order of reactants on particle size distribution and zeta potential were investigated. Nanoparticle structure\\u000a was elucidated by Fourier transform spectroscopy. Particle size of CH\\/CMCG

D. A. Silva; J. S. Maciel; J. P. A. Feitosa; H. C. B. Paula; R. C. M. de Paula

2010-01-01

427

Deeper Insight into the Monoterpenic Composition of Ferula gummosa oleo-gum-resin from Iran  

Microsoft Academic Search

The monoterpenic composition of the essential oil of oleo-gum-resin Ferula gummosa Boiss from Iran was studied by GCGCToFMS. This study allowed to tentatively identify 130 monoterpenic compounds including 24 hydrocarbons, 52 alcohols, 4 ethers, 20 aldehydes, 8 oxides, 18 ketones, 1 furan and 3 epoxides, from which only 25 were reported before in this species. Furthermore, while previous studies identified

Hossein T. Jalali; Slvia Petronilho; Juan J. Villaverde; Manuel A. Coimbra; M. Rosrio M. Domingues; Zahra J. Ebrahimian; Armando J. D. Silvestre; Slvia M. Rocha

428

Immobilized growing lactic acid bacteria with ? -carrageenan locust bean gum gel  

Microsoft Academic Search

Summary A cell entrapment process using ?-carrageenan locust bean gum gel is presented. Streptococcus thermophilus, Lactobacillus bulgaricus and S. lactis were immobilized in small gel beads (0.51.0 mm and 1.02.0 mm diameter) and fermentations in bench bioreactors were conducted. Viability of entrapped cells, lactose utilization, lactic acid production and cell release rates were measured during fermentation. The procedure was

Pascal Audet; Cline Paquin; Christophe Lacroix

1988-01-01

429

The amino acid composition of the proteinaceous component of guar gum (Cyamopsis tetragonolobus)  

Microsoft Academic Search

Guar gum, powdered endosperm from the seeds of the legume Cyamopsis tetragonolobus is a galactomannan which contains 2.54.5% of a proteinaceous component. Data presented for 11 bulk commercial samples show that the most abundant amino acids are glycine, glutamic acid, aspartic acid, serine and alanine, but that their relative proportions vary considerably. The proportions of other amino acids, e.g. histidine,

D. M. W. Anderson; J. F. Howlett; C. G. A. McNab

1985-01-01

430

Preventive dentistryAntimicrobial chewing gum for the elderly in residential homes  

Microsoft Academic Search

Objective The aim of this study was to investigate the attitudes of elderly residents to using an antimicrobial chewing gum as an aid to oral health, and the opinion of their carers on such a procedure.Design A cross-sectional, multi-centre survey using a structured interview\\/questionnaire conducted with elderly residents and their carers.Setting In January 1998, 9 residential\\/nursing homes were chosen at

G Hoad-Reddick

1999-01-01

431

Genetic construction of Xanthomonas campestris and xanthan gum production from whey  

Microsoft Academic Search

Plasmids pUR291 and pNZ521 containing lacZ gene, maturation protein and proteinase P genes, were transferred into X. campestris either by conjugation or by transformation. Plasmid pNZ521 was also conjugally transferred into X. campestris XMT1 a transformant carrying plasmid pUR291. All the constructed strains were evaluated for xanthan gum production in either a medium of 50% whey or the same medium

S. V. Papoutsopoulou; L. V. Ekateriniadou; D. A. Kyriakidis

1994-01-01

432

Xanthan gum: an economical substitute for agar in plant tissue culture media  

Microsoft Academic Search

Xanthan gum, a microbial desiccation-resistant polysaccharide prepared commercially by aerobic submerged fermentation from\\u000a Xanthomonas campestris, has been successfully used as a solidifying agent for plant tissue culture media. Its suitability as a substitute to agar\\u000a was demonstrated for in vitro seed germination, caulogenesis and rhizogenesis of Albizzia lebbeck, androgenesis in anther cultures of Datura innoxia, and somatic embryogenesis in callus

R. Jain; S. B. Babbar

2006-01-01

433

Leaf Respiration of Snow Gum in the Light and Dark. Interactions between Temperature and Irradiance  

Microsoft Academic Search

We investigated the effect of temperature and irradiance on leaf respiration (R, non-photorespiratory mitochondrial CO2 release) of snow gum (Eucalyptus pauciflora Sieb. ex Spreng). Seedlings were hydroponically grown under constant 20C, controlled- environment conditions. Measurements of R (using the Laisk method) and photosynthesis (at 37 Pa CO2) were made at several irradiances (0-2,000 mmol photons m22 s21) and temperatures (6C-30C).

Owen K. Atkin; John R. Evans; Marilyn C. Ball; Hans Lambers; Thijs L. Pons

2000-01-01

434

Effects of nicotine gum on repeated administration of the stroop test  

Microsoft Academic Search

Using a double-blind procedure, 24 non-smoking subjects chewed either 2 mg nicorette gum or a placebo for 20 min, before completing a Stroop test on three occasions. Colour-word reading and simple colour naming times were consistent across repeats, and were unaffected by nicotine. However, the time taken to name the colour of incongruous colour word stimuli declined across trials. This

Stephen C. Provost; Ros Woodward

1991-01-01

435

A Comparison Between Shaker and Bioreactor Performance Based on the Kinetic Parameters of Xanthan Gum Production  

Microsoft Academic Search

Xanthan gum production was studied using sugarcane broth as the raw material and batch fermentation by Xanthomonas campestris pv. campestris NRRL B-1459. The purpose of this study was to optimize the variables of sucrose, yeast extract, and ammonium nitrate concentrations\\u000a and to determine the kinetic parameters of this bioreaction under optimized conditions. The effects of yeast extract and ammonium\\u000a nitrate

S. Faria; P. A. Vieira; M. M. Resende; F. P. Frana; V. L. Cardoso

2009-01-01

436

Efficacy of acacia, pectin, and guar gum-based fiber supplementation in the control of hypercholesterolemia  

Microsoft Academic Search

We examined the lipid-lowering effects of an acacia, pectin, and guar gum-based product marketed as a fiber supplement, in 50 adults (mean age= 55.4 years) who had an LDL-C ? 4.1 mmol\\/l (160 mg\\/dl), or ? 3.4 mmol\\/l (130 mg\\/dl) if at least two coronary risk factors were present. All subjects were instructed on a Step I diet not to

Cindy Hosobuchi; Lapa Rutanassee; Stanley L. Bassin; Nathan D. Wong

1999-01-01

437

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

438

Dissolution enhancement of glimepiride using modified gum karaya as a carrier  

PubMed Central

Objective: The aim of present investigation is to enhance in vitro dissolution of poorly soluble drug glimepiride by preparing solid dispersions using modified gum karaya. Materials and Methods: Solid dispersions of drug were prepared by solvent evaporation method using modified gum karaya as carrier. Four batches of solid dispersion (SD1, SD4, SD9, and SD14) and physical mixture (PM1, PM4, PM9, and PM14) were prepared and characterized by differential scanning colorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, powder X-Ray diffraction (X-RD), and scanning electron microscopy (SEM) studies. Equilibrium solubility studies were carried out in shaker incubator for 24 h and in vitro drug release was determined using USP Dissolution Apparatus-II. Results: Maximum solubility and in vitro dissolution were observed with Batch SD4. No significant enhancement of dissolution characteristics were observed in the corresponding physical mixture PM4. Low viscosity with comparable swelling characteristics as compared to GK of modified form of gum karaya may lead to improvement in dissolution behavior of solid dispersion batches. Also, the conversion of crystalline form of drug to amorphous form may be a responsible factor, which was further confirmed by DSC, FTIR studies, and X-RD studies. SEM photographs of batch SD4 revealed porous nature of particle surface. Conclusion: Modified forms of natural carriers prove beneficial in dissolution enhancement of poorly soluble drugs and exhibited a great potential in novel drug delivery systems.

Nagpal, Manju; Rajera, Rampal; Nagpal, Kalpana; Rakha, Pankaj; Singh, SK; Mishra, DN

2012-01-01

439

A study of the neutral hydrogen in direction to the GUM nebula  

NASA Astrophysics Data System (ADS)

This paper presents 44 gray-scale maps at constant velocity of the distribution of H I in the direction of the Gum nebula. It is shown that there is no H I shell with a size comparable to the 36 deg diameter optical nebulosities and that there is a thick H I shell, about 7 deg in radius, shifted from the center of the optical nebula by more than 10 deg. The observations are consistent with a model in which the Gum nebula is the remnant of a supernova explosion that occurred about 2.6 million yr ago. The presence of two new H I bubbles associated with SWR 12 and 14, plus a possible one around WR 13, are disclosed from analysis of the H I gas distribution around the four WR star located beyond the Gum nebula. These H I bubbles have characteristics similar to those previously observed. Three shell-like objects probably related to OB stars and H II regions are also described.

Dubner, G.; Giacani, E.; Cappa de Nicolau, C.; Reynoso, E.

1992-12-01

440

[Assessment of three methods for the identification of enzymatically hydrolyzed guar gum].  

PubMed

Enzymatically hydrolyzed guar gum (EHGG), which is used as a thickener or a soluble dietary fiber, is produced by partial hydrolysis of the guar gum (GG) backbone using mannan endo-?-1,4-mannosidase. In this study, we compared and evaluated 3 methods to distinguish EHGG from other polysaccharides used as food additives or monosaccharides. The first method is based on cross-linking reaction of saccharide hydroxyl groups mediated by borate ions. EHGG showed gelation and was distinguished from some soluble polysaccharides, which did not form gels, and also from polysaccharides with low solubility in water. The second method is based on co-gelation with xanthan gum. It was applicable to GG, but not to EHGG. The third method is based on the alcohol precipitation of hydrophilic polymers. EHGG, some soluble polysaccharides and monosaccharides were dissolved in water at the concentration of 10%, while GG and some polysaccharides were not. The 10% solutions thus obtained were mixed with 2-propanol at the ratio of 1 : 1 (v/v). A white precipitate was formed in the EHGG solutions and the tested soluble polysaccharide solutions, while it was not produced in the monosaccharide solutions. This result demonstrated that soluble polysaccharides including EHGG can be distinguished from polysaccharides with low solubility or monosaccharides by the third method. PMID:23470876

Akiyama, Takumi; Sekiguchi, Wakana; Yamazaki, Takeshi; Akiyama, Hiroshi

2013-01-01

441

Comparative effects of xylitol- and sucrose-sweetened chew tablets and chewing gums on plaque quantity.  

PubMed

The effects of chewing gums and chew tablets sweetened with sucrose or xylitol on the quantity and adhesivity of dental plaque were studied with 14 volunteer dental students (mean age 23.2). The subjects participated in a four-phase study in which one of four different test products was used during each period. The 3-d periods were interspaced with 4-d normalization phases. The following four experimental products were tested: chewing gums (CG) and chew tablets (CT), sweetened with sucrose (s) or xylitol (x). The amount of plaque was determined through an automatic planimetric procedure on teeth treated with Dentotest. The total plaque areas before brushing were significantly larger in the CTs group compared with the CTx group. After brushing, the plaque areas remained larger in the CTs group. In the determination of the thick plaque areas, the use of CTx was associated with significantly smaller plaque scores than the use of CTs. In the adhesivity studies CGx consistently yielded the lowest plaque scores, but the differences between x and s were not significant. The comparison between CT and CG suggested that CTx produced significantly smaller plaque scores than CGx before brushing, but not after. This finding was considered to result from the differences involved in the texture and chemical composition between tablets and chewing gums. The present study showed that the use of CGx and CTx was associated with clinically more advantageous plaque effects than the use of corresponding products sweetened with sucrose. PMID:6952539

Rekola, M

1981-10-01

442

Multimodal assessment of the effect of chewing gum on nicotine withdrawal.  

PubMed

The present study was designed to evaluate the usefulness of chewing gum to reduce nicotine withdrawal, craving, and salivary cortisol concentrations during temporary nicotine deprivation. A total of 20 male smokers were studied under conditions when gum was and was not accessible during a 4-hour deprivation period. All subjects smoked an initial cigarette shortly after arrival for the two experimental sessions and were informed that they would be unable to smoke for the remainder of each session. The sessions consisted of each subject watching a movie, then waiting in the lab for two consecutive 30-min intervals. Self-reported nicotine withdrawal and craving were assessed four times and salivary cortisol five times during each experimental session. Results from this study indicate that chewing gum helps with self-reported withdrawal but not craving when a smoker is prevented from smoking. This study also provides preliminary data on the use of salivary cortisol as a physiological marker that may map these self-reports of nicotine withdrawal and craving. PMID:11316385

Cohen, L M; Britt, D M; Collins, F L; Al'Absi, M; McChargue, D E

443

The stability of ascorbic acid microencapsulated in granules of rice starch and in gum arabic.  

PubMed

Ascorbic acid (AA) was microencapsulated by spray drying, using gum arabic and rice starch as covering materials. The AA was dissolved in solutions of the wall material prior to processing. For the rice starch, gelatin was used as a binding agent and recovery was effected with calcium pectate. The morphology of the materials was analysed by optical and scanning electron microscopy, it thus being possible to verify the formation and evaluate the structural characteristics of the microcapsules. The capsules produced with gum arabic were smaller (d50% = 8.0 microns) and with a multimode particle size distribution, whilst uncovered starch capsules containing 1-2% gelatin presented a distribution mainly in the range of 5-40 microns. The capsules recovered with calcium pectate had average diameters 10-15 times greater than those obtained only by spray drying. The stability of the encapsulated materials was studied at room temperature (RH 60-65%) and at 45 degrees C (RH 60-65% and 90.7%). AA microencapsulated in gum arabic was shown to be as stable as free crystalline AA under environmental conditions, whereas that encapsulated in rice starch was less stable. Increasing the amount of the binding agent gelatin increased the stability of the uncovered starch encapsulated AA. Recovery with calcium pectate notably increased the stability of the starch encapsulated AA, as compared to the uncovered samples. PMID:10738692

Trindade, M A; Grosso, C R

444

The effect of guar gum on fluid friction in spiral pipe  

NASA Astrophysics Data System (ADS)

Pipeline is the most effective equipment to transport of fluid. Based on the shape, pipe can classify as circular, square, triangle and spiral. Each shape has different characteristics. On the transport of fluid using pipe, pressure drop is very important aspect because related with energy consumption. Special pipe as spiral pipe is used as a fuel mixing system of fuel. It is intended to prevent precipitation and to reduce the pressure drop. The purpose of this research is to investigate the reduction of pressure drop in a spiral pipe with the addition biopolymer (guar gum). Spiral pipe with the best aspect ratio, P/Di = 7 is used in this study. Working fluid used guar gum solution of 150 ppm and 200 ppm. Circular pipe with same diameter is used for comparison. Analysis of flow characteristics based on the power law model for non-Newtonian fluid. Experimental was conducted from low to high Reynolds number up to 60,000. The results showed that the effect of biopolymer guar gum solution can reduce drag either on a circular pipe and spiral pipe.

Yanuar; Gunawan; Baqi, M.

2012-06-01

445

Real-time investigation of mannosyltransferase function of a Xylella fastidiosa recombinant GumH protein using QCM-D.  

PubMed

Xylella fastidiosa is a gram-negative bacterium that causes serious diseases in economically important crops, including grapevine, coffee, and citrus fruits. X. fastidiosa colonizes the xylem vessels of the infected plants, thereby blocking water and nutrient transport. The genome sequence of X. fastidiosa has revealed an operon containing nine genes possibly involved in the synthesis of an exopolisaccharide (EPS) named fastidian gum that can be related with the pathogenicity of this bacterium. The ?-1,3-mannosyltransferase (GumH) enzyme from X. fastidiosa is involved in fastidian gum production. GumH is responsible for the transfer of mannose from guanosine diphosphate mannose (GDP-man) to the cellobiose-pyrophosphate-polyprenol carrier lipid (CPP-Lip) during the assembly and biosynthesis of EPS. In this work, a method for real-time detection of recombinant GumH enzymatic activity was successfully developed using a Quartz Crystal Microbalance with dissipation monitoring (QCM-D). The QCM-D transducer was strategically modified with CPP-Lip by using a solid-supported lipid bilayer that makes use of a self-assembled monolayer of 1-undecanethiol. Monitoring the real-time CPP-Lip QCM-D transducer in the presence of GDP-man and GumH enzyme shows a mass increase, indicating the transfer of mannose. The real-time QCM-D determination of mannosyltransferase function was validated by a High Performance Liquid Chromatography (LC) method developed for determination of GDP produced by enzymatic reaction. LC results confirmed the activity of recombinant GumH protein, which is the first enzyme involved in the biosynthesis of the EPS from X. fastidiosa enzymatically characterized. PMID:21521632

Alves, Claudia A; Pedroso, Mariele M; de Moraes, Marcela C; Souza, Dulce H F; Cass, Quezia B; Faria, Ronaldo C

2011-04-19

446

Highly viscous guar gum shifts dietary amino acids from metabolic use to fermentation substrate in domestic cats.  

PubMed

The present study evaluated the potential of affecting amino acid metabolism through intestinal fermentation in domestic cats, using dietary guar gum as a model. Apparent protein digestibility, plasma fermentation metabolites, faecal fermentation end products and fermentation kinetics (exhaled breath hydrogen concentrations) were evaluated. Ten cats were randomly assigned to either guar gum- or cellulose-supplemented diets, that were fed in two periods of 5 weeks in a crossover design. No treatment effect was seen on fermentation kinetics. The apparent protein digestibility (P= 0.07) tended to be lower in guar gum-supplemented cats. As a consequence of impaired small-intestinal protein digestion and amino acid absorption, fermentation of these molecules in the large intestine was stimulated. Amino acid fermentation has been shown to produce high concentrations of acetic and butyric acids. Therefore, no treatment effect on faecal propionic acid or plasma propionylcarnitine was observed in the present study. The ratio of faecal butyric acid:total SCFA tended to be higher in guar gum-supplemented cats (P= 0.05). The majority of large-intestinal butyric acid is absorbed by colonocytes and metabolised to 3-hydroxy-butyrylcoenzyme A, which is then absorbed into the bloodstream. This metabolite was analysed in plasma as 3-hydroxy-butyrylcarnitine, which was higher (P= 0.02) in guar gum-supplemented cats. In all probability, the high viscosity of the guar gum supplement was responsible for the impaired protein digestion and amino acid absorption. Further research is warranted to investigate whether partially hydrolysed guar gum is useful to potentiate the desirable in vivo effects of this fibre supplement. PMID:22877608

Rochus, Kristel; Janssens, Geert P J; Van de Velde, Hannelore; Verbrugghe, Adronie; Wuyts, Birgitte; Vanhaecke, Lynn; Hesta, Myriam

2012-08-09

447

Effects of guar gum and cellulose on glucose absorption, hormonal release and hepatic metabolism in the pig.  

PubMed

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. PMID:1337269

Nunes, C S; Malmlf, K

1992-11-01

448

Crystallization dynamics in model emulsions from magnetic resonance imaging  

Microsoft Academic Search

Melt crystallization of trilaurin and trimyristin was investigated in the bulk and in dispersed systems using magnetic resonance\\u000a imaging. Crystallization rates were studied as a function of time in fat\\/water (40:60) emulsions containing 0.5% tween 80\\u000a and 0.2% xanthan gum to prevent creaming. Oil weighted images were obtained to follow the dynamics of crystallization in the\\u000a bulk and in an

C. Simoneau; M. J. McCarthy; R. J. Kauten; J. B. German

1991-01-01

449

The effect of over-the-counter sales of the nicotine patch and nicotine gum on smoking cessation in California.  

PubMed

The Food and Drug Administration approved over-the-counter (OTC) sale of nicotine gum and nicotine patches in 1996. We used data from the 1996 California Tobacco Survey to compare the rates of nicotine replacement therapy (NRT) use and smoking abstinence in California for each month during a period immediately preceding and immediately following the OTC availability of nicotine gum and patches. For smokers eligible to report a quit attempt, the proportion making a quit attempt using NRT and the proportion remaining abstinent was calculated for each of the 12 months prior to the survey interview. Multiple regression modeling of quit attempts and abstinence included a term for the number of months between the quit attempt and survey interview and dummy variables for the months before and after the OTC availability of NRT. Results showed a significant increase in the fraction of smokers using the patch (P < 0.01) and gum (P < 0.05) immediately following their availability OTC. There was also a significantly higher proportion of smokers reporting abstinence with gum use (P < 0.01) and a significant increase in reported abstinence with patch use (P < 0.01) during the period of time immediately following the availability of these products without a prescription. The results of this study suggest that removing the prescription status of NRT products resulted in an immediate increase in quit attempts and smoking abstinence with the use of nicotine gum or patches. PMID:16172221

Reed, Mark B; Anderson, Christy M; Vaughn, Jerry W; Burns, David M

2005-09-01

450

Effect of gum tragacanth on rheological and physical properties of a flavored milk drink made with date syrup.  

PubMed

Date syrup as a nutritional additive and safe alternative to added sugar is one of the best choices for milk flavoring. In this study, a flavored milk beverage was formulated using date syrup for flavoring the product and gum tragacanth to obtain an acceptable mouth feel. Steady shear and dynamic oscillatory rheological properties of the samples contained 3 concentrations (0, 0.1, 0.2, and 0.3%, wt/wt) of 2 types of gum tragacanth (Astragalus gossypinus and Astragalus rahensis) which at 3C, were studied. Particle size distribution and colorimetric assays were determined by laser diffractometry and using reflection spectrometer, respectively. Sensory analysis was performed with 25 semitrained panelists, using a 5-point hedonic scale. The results showed that viscoelastic properties, flow behavior parameters, particle size, and color parameters (L*, a*, and b*, where L* represents lightness, a* represents the redness/greenness quality of the color, and b* represents the yellowness and blueness quality of the colors) were significantly affected by the concentration of the gum tragacanth and the severity of this effect was influenced by the type of gum. The use of appropriate type and concentration of gum tragacanth in date milk formulation can improve the texture and mouth feel by affecting on particle size and the flow behavior of this product. PMID:23746580

Keshtkaran, Maryam; Mohammadifar, Mohammad Amin; Asadi, Gholam Hassan; Nejad, Reza Azizi; Balaghi, Sima

2013-06-05

451

Group B streptococcus carriage and vulvovaginal symptoms: causal or casual? A case-control study in a GUM clinic population  

PubMed Central

Objectives: The isolation of group B streptococcus (GBS) on routine swabs taken from genitourinary medicine (GUM) clinic attendees is a common finding. The relation of GBS to vulvovaginal symptoms is unclear, creating confusion about management. This case-control study tested the hypothesis that detection of GBS on routine clinical specimens is not causally related to vulvovaginal symptoms in female GUM clinic attendees. Methods: Data were collected on all female GUM clinic attendees who had GBS isolated from anogenital swabs between July 1999 and July 2001. Controls were randomly selected from all new and rebooking female GUM clinic attendees. Controls were group matched for age with cases and were included only if a sexual health screen was performed and the results of this were available. Results: 118 cases and 308 controls were identified during the study period. There was no significant difference between cases and controls in patient demographic or behavioural characteristics, the presence of genital co-infection, or vulvovaginal symptoms. There was no relation between symptoms and quantitative growth of GBS reported by the laboratory in either cervical or urethral swabs. Only nine cases had high vaginal swabs taken, in whom there was a significant association between a heavy growth of GBS and vulvovaginal symptoms (p=0.008). Conclusion: The isolation of GBS from routinely collected genital swabs in female attendees of a GUM clinic is not causally related to vulvovaginal symptoms. We recommend that patients should receive this advice and should not be treated with antibiotic therapy for this indication.

Shaw, C; Mason, M; Scoular, A

2003-01-01

452

Development of reduced-fat mayonnaise using 4alphaGTase-modified rice starch and xanthan gum.  

PubMed

In this study a disproportionating enzyme, 4-alpha-glucanotransferase (4alphaGTase), was used to modify the structural properties of rice starch to produce a suitable fat substitute in reduced-fat (RF) mayonnaise. The mayonnaise fat was partially substituted with the 4alphaGTase-treated starch paste at levels up to 50% in combination with xanthan gum and the physical and rheological properties of the modified RF mayonnaise samples were investigated. All mayonnaises prepared in this study exhibited shear thinning behavior and yield stress. Viscoelastic properties of mayonnaise were characterized using dynamic oscillatory shear test and it was observed that mayonnaises exhibited weak gel-like properties. The magnitude of elastic and loss moduli was also affected by 4alphaGTase-treated starch concentration and presence of xanthan gum. In relation to microstructure, RF mayonnaise prepared with 3.8 or 5.6 wt% of 4alphaGTase-treated starch and xanthan gum showed smaller droplets. The use of 5.6 wt% of 4alphaGTase-treated starch and 0.1 wt% of xanthan gum produced a RF mayonnaise with similar rheological properties and appearances as FF mayonnaise with gum. This study demonstrated a high feasibility for using 4alphaGTase-treated rice starch as a viable fat replacer in mayonnaise. PMID:19428473

Mun, Saehun; Kim, Young-Lim; Kang, Choon-Gil; Park, Kwan-Hwa; Shim, Jae-Yong; Kim, Yong-Ro

2009-03-14

453

Characterization and preliminary toxicity assay of nano-titanium dioxide additive in sugar-coated chewing gum.  

PubMed

Nanotechnology shows great potential for producing food with higher quality and better taste through including new additives, improving nutrient delivery, and using better packaging. However, lack of investigations on safety issues of nanofood has resulted in public fears. How to characterize engineered nanomaterials in food and assess the toxicity and health impact of nanofood remains a big challenge. Herein, a facile and highly reliable separation method of TiO2 particles from food products (focusing on sugar-coated chewing gum) is reported, and the first comprehensive characterization study on food nanoparticles by multiple qualitative and quantitative methods is provided. The detailed information on nanoparticles in gum includes chemical composition, morphology, size distribution, crystalline phase, particle and mass concentration, surface charge, and aggregation state. Surprisingly, the results show that the number of food products containing nano-TiO2 (<200 nm) is much larger than known, and consumers have already often been exposed to engineered nanoparticles in daily life. Over 93% of TiO2 in gum is nano-TiO2 , and it is unexpectedly easy to come out and be swallowed by a person who chews gum. Preliminary cytotoxicity assays show that the gum nano-TiO2 particles are relatively safe for gastrointestinal cells within 24 h even at a concentration of 200 ?g mL(-1) . This comprehensive study demonstrates accurate physicochemical property, exposure, and cytotoxicity information on engineered nanoparticles in food, which is a prerequisite for the successful safety assessment of nanofood products. PMID:23065899

Chen, Xin-Xin; Cheng, Bin; Yang, Yi-Xin; Cao, Aoneng; Liu, Jia-Hui; Du, Li-Jing; Liu, Yuanfang; Zhao, Yuliang; Wang, Haifang

2012-10-15

454

Formulation and Evaluation of Bilayer Tablet of Metoclopramide Hydrochloride and Ibuprofen  

Microsoft Academic Search

The aim of this study was to prepare bi-layer tablet of Metoclopramide Hydrochloride (MTH) and Ibuprofen (IB) for the effective\\u000a treatment of migraine. MTH and IB were formulated as immediate and sustained release layer respectively. MTH was formulated\\u000a as immediate release layer by using various disintegrants like Ac-Di-Sol, Polyplasdone XL, Explotab, Agar and Gellan Gum.\\u000a Treated form of gellan gum

Bhavesh Shiyani; Surendra Gattani; Sanjay Surana

2008-01-01

455

Highly efficient system of plant regeneration from protoplasts of grapevine ( Vitis vinifera L.) through somatic embryogenesis by using embryogenic callus culture and activated charcoal  

Microsoft Academic Search

A simple protocol is described for high frequency plant regeneration from protoplasts isolated from leaf-derived embryogenic calli of grapevine (Vitis vinifera L. cv. Koshusanjaku). The protoplasts successfully divided to form somatic embryos by culturing in gellan gum disc-method in which protoplasts were embedded in 2 g\\/l gellan gum-solidified Nitsch's medium containing 2.0 mg\\/l NAA, 0.5 mg\\/l BA, 0.09 M sucrose

Yan-Ming Zhu; Yoichiro Hoshino; Masaru Nakano; Eikichi Takahashi; Masahiro Mii

1997-01-01

456

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

457

Coverage interval estimation of the measurement of Gross Heat of Combustion of fuel by bomb calorimetry: Comparison of ISO GUM and adaptive Monte Carlo method  

Microsoft Academic Search

The Guide to Uncertainty of Measurement (GUM) approach and the adaptive Monte Carlo method (MCM) provide two alternative approaches for the propagation stage of the uncertainty estimation. These two approaches are implemented and compared concerning the 95% coverage interval estimation of the measurement of Gross Heat of Combustion (GHC) of an automotive diesel fuel by bomb calorimetry. The GUM approach,

D. Theodorou; Y. Zannikou; G. Anastopoulos; F. Zannikos

2011-01-01

458

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.

Ansari, Siddique Akber; Cencetti, Claudia; Carafa, Maria; Mazzuca, Claudia; Capitani, Donatella; Coviello, Tommasina

2013-01-01

459

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

2013-08-05

460

Functions of fenugreek gum with various molecular weights on the gelatinization and retrogradation behaviors of corn starch2: Characterizations of starch and investigations of corn starch\\/fenugreek gum composite system at a relatively low starch concentration; 5 w\\/v%  

Microsoft Academic Search

Gelatinization and retrogradation behaviors of corn starch were investigated in an aqueous system in the presence or absence of fenugreek gum with various molecular weights. The addition of fenugreek gum (0.5w\\/v%) increased peak viscosity of the composite system (5% starch) during gelatinization when coil overlap parameter C[?] and weight-average molecular weight Mw of the gum were larger than 2.38 and

Takahiro Funami; Yohei Kataoka; Sakie Noda; Mika Hiroe; Sayaka Ishihara; Iwao Asai; Rheo Takahashi; Naoyoshi Inouchi; Katsuyoshi Nishinari

2008-01-01

461

Chewing gum alleviates negative mood and reduces cortisol during acute laboratory psychological stress.  

PubMed

The notion that chewing gum may relieve stress was investigated in a controlled setting. A multi-tasking framework which reliably evokes stress and also includes performance measures was used to induce acute stress in the laboratory. Using a randomised crossover design forty participants (mean age 21.98 years) performed on the multi-tasking framework at two intensities (on separate days) both while chewing and not chewing. Order of workload intensity and chewing conditions were counterbalanced. Before and after undergoing the platform participants completed the state portion of the State-Trait Anxiety Inventory, Bond-Lader visual analogue mood scales, a single Stress Visual Analogue Scale and provided saliva samples for cortisol measurement. Baseline measures showed that both levels of the multi-tasking framework were effective in significantly reducing self-rated alertness, calmness and contentment while increasing self-rated stress and state anxiety. Cortisol levels fell during both levels of the stressor during the morning, reflecting the predominance of a.m. diurnal changes, but this effect was reversed in the afternoon which may reflect a measurable stress response. Pre-post stressor changes (Delta) for each measure at baseline were subtracted from Delta scores under chewing and no chewing conditions. During both levels of stress the chewing gum condition was associated with significantly better alertness and reduced state anxiety, stress and salivary cortisol. Overall performance on the framework was also significantly better in the chewing condition. The mechanisms underlying these effects are unknown but may involve improved cerebral blood flow and/or effects secondary to performance improvement during gum chewing. PMID:19268676

Scholey, Andrew; Haskell, Crystal; Robertson, Bernadette; Kennedy, David; Milne, Anthea; Wetherell, Mark

2009-03-05

462

Caffeinated chewing gum increases repeated sprint performance and augments increases in testosterone in competitive cyclists.  

PubMed

This investigation reports the effects of caffeinated chewing gum on fatigue and hormone response during repeated sprint performance with competitive cyclists. Nine male cyclists (meanSD, age 247years, VO(2max) 62.55.4mLkg(-1)min(-1)) completed four high-intensity experimental sessions, consisting of four sets of 30s sprints (5 sprints each set). Caffeine (240mg) or placebo was administered via chewing gum following the second set of each experimental session. Testosterone and cortisol concentrations were assayed in saliva samples collected at rest and after each set of sprints. Mean power output in the first 10 sprints relative to the last 10 sprints declined by 5.84.0% in the placebo and 0.47.7% in the caffeine trials, respectively. The reduced fatigue in the caffeine trials equated to a 5.4% (90% confidence limit 3.6%, effect size 0.25; 0.16) performance enhancement in favour of caffeine. Salivary testosterone increased rapidly from rest (~53%) and prior to treatments in all trials. Following caffeine treatment, testosterone increased by a further 1214% (ES 0.50;0.56) relative to the placebo condition. In contrast, cortisol concentrations were not elevated until after the third exercise set; following the caffeine treatment cortisol was reduced by 2131% (ES -0.30;0.34) relative to placebo. The acute ingestion of caffeine via chewing gum attenuated fatigue during repeated, high-intensity sprint exercise in competitive cyclists. Furthermore, the delayed fatigue was associated with substantially elevated testosterone concentrations and decreased cortisol in the caffeine trials. PMID:20737165

Paton, Carl D; Lowe, Timothy; Irvine, Athena

2010-08-25

463

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

464

Potential of guar gum microspheres for target specific drug release to colon.  

PubMed

Various approaches for colon targeted drug delivery have been studied over the last decade including, pro-drugs, timed-released systems, coating of pH-dependant polymer and the use of polysaccharides. In the present work, a novel formulation consisting of cross-linked microspheres of guar gum has been investigated for colon-targeted delivery of metronidazole. An emulsification method involving the dispersion of aqueous solution of guar gum in castor oil was used to prepare spherical microspheres. Process parameters were analyzed in order to optimize the formulation. Shape and surface morphology of the microspheres were examined using scanning electron microscopy. Placebo microspheres exhibited a smooth surface while the incorporation of drug imparted a slight roughness to the surface texture. Particle size of the microspheres was determined using laser diffraction particle size analyzer. The in vitro drug release studies were performed in simulated gastric fluid for 2 h and intestinal fluid for 3 h, which revealed that the drug was retained comfortably inside the microspheres and that only 15.27+/-0.56% of the drug was released in 5 h. In vitro release rate studies were also carried out in simulated colonic fluid (SCF) in the presence of rat cecal contents, which showed improved drug release. Moreover, to induce the enzymes that specifically act on guar gum, the rats were treated with 1 ml of 1% w/v dispersion of guar gum for 2, 4 and 6 days and release rate studies were repeated in SCF in the presence of 2 and 4% w/v of cecal matter. A marked improvement in the drug release was observed in presence of cecal matter obtained after induction when compared to those without induction. In vitro release studies exhibited 31.23+/-1.49% drug release in 24 h in dissolution medium without rat cecal matter. However, the incorporation of 4% w/v cecal matter obtained after 6 days of enzymes induction increased the drug release to 96.24+/-4.77%. PMID:15621668

Chourasia, M K; Jain, S K

2004-01-01

465

Feasibility of xanthan gumsodium alginate as a transdermal drug delivery system for domperidone  

Microsoft Academic Search

The present investigation comprises the formulation and in vitro evaluation of domperidone loaded transdermal drug delivery\\u000a system (TDDS) for controlled release. The polymer membranes were prepared using xanthan gum (XG) and sodium alginate (SA)\\u000a by varying the blends compositions viz., 10:0, 8:2, 6:4, 5:5, 4:6, 2:8, and 0:10 (XG\\/SA, wt\\/wt, %). The drug loaded membranes\\u000a were evaluated for thickness, content

N. Rajesh; Siddaramaiah

2009-01-01

466

Drinking coffee and carbonated beverages blocks absorption of nicotine from nicotine polacrilex gum.  

PubMed

Patients failing to obtain benefit from nicotine polacrilex gum in their efforts to quit smoking may be inadvertently blocking nicotine absorption. Effective nicotine absorption depends on the mildly alkaline saliva that is produced when buffering agents in the polacrilex are released along with nicotine as the polacrilex is chewed. We found that intermittent mouth rinsing with coffee or cola, but not distilled water, substantially reduced salivary pH and nicotine absorption. Because many commonly consumed substances were also found to be highly acidic, we recommend that patients do not ingest any substance during or immediately before nicotine polacrilex use. PMID:2395197

Henningfield, J E; Radzius, A; Cooper, T M; Clayton, R R

1990-09-26

467

Cycloartane triterpenes from dikamali, the gum resin of Gardenia gummifera and Gardenia lucida.  

PubMed

We report on the chemical investigation of dikamali gum, which is the resin of Gardenia gummifera and G. lucida (Rubiaceae). Six new cycloartane triterpenes, dikamaliartanes A-F (1-6, resp.), together with a known flavonoid (7), were isolated and identified by NMR spectroscopy. All six cycloartanes are characterized by an open A-ring with a free COOH group at C(3). In four of them, the C-atoms C(23)-C(27) form a 4-methylfuran-2-yl moiety. Bacterial assays using Staphylococcus aureus, Candida albicans, and Mycobact