Note: This page contains sample records for the topic magnetic gellan gum from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: August 15, 2014.
1

21 CFR 172.665 - Gellan gum.  

Code of Federal Regulations, 2010 CFR

...specifications: (1) Positive for gellan gum when subjected to the following identification...made by hydrating 1 gram of gellan gum in 99 milliliters of distilled...determined by the procedure described in the Xanthan Gum monograph, the âFood...

2009-04-01

2

21 CFR 172.665 - Gellan gum.  

Code of Federal Regulations, 2010 CFR

...specifications: (1) Positive for gellan gum when subjected to the following identification...made by hydrating 1 gram of gellan gum in 99 milliliters of distilled...determined by the procedure described in the Xanthan Gum monograph, the âFood...

2010-01-01

3

Evaluation of carboxymethyl gellan gum as a mucoadhesive polymer.  

PubMed

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

Ahuja, Munish; Singh, Seema; Kumar, Ashok

2013-02-01

4

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

5

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

PubMed

In this study, the cometabolic degradation of carbazole (CA), dibenzofuran (DBF), and dibenzothiphene (DBT) by immobilized Arthrobacter sp. W1 cells pregrown with naphthalene was investigated. Four kinds of polymers were evaluated as immobilization supports for strain W1. After comparison with agar, alginate, and ?-carrageenan, gellan gum was selected as the optimal immobilization support. Furthermore, magnetic Fe3O4 nanoparticle was selected as most suitable nanoparticle for immobilization and the optimal concentration was 80mg/L. The relationship between specific degradation rate and the initial concentration of CA, DBF and DBT was described well by Michaelis-Menten kinetics. The recycling experiments demonstrated that the magnetically immobilized cells coupling with activation zeolite showed highly bioremediation activity on the coking wastewater containing high concentration of phenol, naphthalene, CA, DBF and DBT during seven recycles. Toxicity assessment indicated the treatment of the coking wastewater by magnetically immobilized cells with activation zeolite led to less toxicity than untreated wastewater. PMID:24905045

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

2014-08-01

6

Deproteinization of gellan gum produced by Sphingomonas paucimobilis ATCC 31461.  

PubMed

Deproteinization is a technical bottleneck in the purification of viscous water-soluble polysaccharides. The aim of this work is to provide an appropriate approach to deproteinize crude gellan gum. Several methods of deproteinization were investigated, including Sevag method, alkaline protease, papain and neutral protease. The results revealed that Sevag method had high deproteinization efficiency (87.9%), but it showed dissatisfactory recovery efficiency of gellan gum (28.6%), which made it less advisable in industrial applications. The deproteinization by alkaline protease was demonstrated in this work for the first time, indicating alkaline protease was preferred in the deproteinization of crude gellan gum with high polysaccharide recovery (89.3%) and high deproteinization efficiency (86.4%). PMID:17069918

Wang, Xia; Yuan, Yong; Wang, Kainai; Zhang, Dezhong; Yang, Zhengting; Xu, Ping

2007-02-01

7

Gellan Gum: Fermentative Production, Downstream Processing and Applications  

Microsoft Academic Search

Summary The microbial exopolysaccharides are water-soluble polymers secreted by microorgan- isms during fermentation. The biopolymer gellan gum is a relatively recent addition to the family of microbial polysaccharides that is gaining much importance in food, pharmaceu- tical and chemical industries due to its novel properties. It is commercially produced by C. P. Kelco in Japan and the USA. Further research

Ishwar B. Bajaj; Shrikant A. Survase; Parag S. Saudagar; Rekha S. Singhal

2007-01-01

8

Gellan gum: a new biomaterial for cartilage tissue engineering applications.  

PubMed

Gellan gum is a polysaccharide manufactured by microbial fermentation of the Sphingomonas paucimobilis microorganism, being commonly used in the food and pharmaceutical industry. It can be dissolved in water, and when heated and mixed with mono or divalent cations, forms a gel upon lowering the temperature under mild conditions. In this work, gellan gum hydrogels were analyzed as cells supports in the context of cartilage regeneration. Gellan gum hydrogel discs were characterized in terms of mechanical and structural properties. Transmissionelectron microscopy revealed a quite homogeneous chain arrangement within the hydrogels matrix, and dynamic mechanical analysis allowed to characterize the hydrogels discs viscoelastic properties upon compression solicitation, being the compressive storage and loss modulus of approximately 40 kPa and 3 kPa, respectively, at a frequency of 1 Hz. Rheological measurements determined the sol-gel transition started to occur at approximately 36 degrees C, exhibiting a gelation time of approximately 11 s. Evaluation of the gellan gum hydrogels biological performance was performed using a standard MTS cytotoxicity test, which showed that the leachables released are not deleterious to the cells and hence were noncytotoxic. Gellan gum hydrogels were afterwards used to encapsulate human nasal chondrocytes (1 x 10(6) cells/mL) and culture them for total periods of 2 weeks. Cells viability was confirmed using confocal calcein AM staining. Histological observations revealed normal chondrocytes morphology and the obtained data supports the claim that this new biomaterial has the potential to serve as a cell support in the field of cartilage regeneration. PMID:19658177

Oliveira, J T; Martins, L; Picciochi, R; Malafaya, P B; Sousa, R A; Neves, N M; Mano, J F; Reis, R L

2010-06-01

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

2011-06-01

10

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

NASA Astrophysics Data System (ADS)

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

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

2013-08-01

11

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

PubMed

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. PMID:22134682

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

2012-01-21

12

Application of gellan gum in pharmacy and medicine.  

PubMed

Over the past few decades, microbial polysaccharides have been under intense investigation due to their advantageous physicochemical properties. A great structural diversity of these biomolecules has led to multiple applications in food industry, personal care products, pharmacy and medicine. Currently, one of the most widely studied and fully described member of this group is gellan. It is a linear polymer produced by Sphingomonas elodea. A polymer chain of gellan consists of a tetrasaccharide repeating unit of l-rhamnose, d-glucose and d-glucuronate. So far most of the studies have been focused on the application of gellan as a food ingredient. However, due to the unique structure and beneficial properties, gellan is currently described as a potent multifunctional additive for various pharmaceutical products. Specific gelling properties in different media led to the development of controlled release forms based on gellan. Various formulations have been studied including oral, ophthalmic, nasal and other. Recent reports suggest that gellan-based materials can also be used in regenerative medicine, stomatology or gene transfer technology. PMID:24657577

Osma?ek, Tomasz; Froelich, Anna; Tasarek, Sylwia

2014-05-15

13

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

2011-07-01

14

Interpenetrating polymer network microcapsules of gellan gum and egg albumin entrapped with diltiazem–resin complex for controlled release application  

Microsoft Academic Search

Diltiazem HCl, a water soluble drug was bound to Indion 254®, a cation exchange resin and resulting drug–resin complex was entrapped within interpenetrating polymer network (IPN) microcapsules of gellan gum and egg albumin prepared by ionotropic gelation and covalent crosslinking method. The IPN microcapsules were characterized by SEM, DSC, TGA, XRD and FTIR analyses. The pure drug diltiazem showed rapid

Raghavendra V. Kulkarni; Banappa S. Mangond; Srinivas Mutalik; Biswanath Sa

2011-01-01

15

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

PubMed

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

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

2009-05-01

16

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

2013-06-01

17

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

2011-10-01

18

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, António J; Reis, Rui L; Shoichet, Molly S

2012-09-01

19

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 Glória; Oliveira, Joao T; Sousa, Rui A; Salgado, Antonio J; Oliveira, Joaquim M; Mano, João F; Sousa, Nuno; Reis, Rui L

2011-10-01

20

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

PubMed

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

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

2013-12-01

21

Optimization of nutrients for gellan gum production by Sphingomonas paucimobilis ATCC-31461 in molasses based medium using response surface methodology.  

PubMed

A molasses based medium for the production of gellan by Sphingomonas paucimobilis ATCC-31461 was developed. Placket-Burman design criterion was applied to study the effect of various nutrient supplements on gellan production using molasses. Among the 20 variables tested, molasses, tryptone, casaminoacid, disodium hydrogen orthophosphate and manganese chloride showed significant effect on gellan production. A central composite design was applied to determine the optimum concentrations of the significant variables obtained from Placket-Burman design. Most suitable medium composition for production of gellan was (g/l): molasses-112.5; tryptone-1; casaminoacid-1; disodium hydrogen orthophosphate-1; manganese chloride-0.947 and the optimum gellan production was 13.814 g/l. PMID:16707262

Banik, R M; Santhiagu, A; Upadhyay, S N

2007-03-01

22

Optimization of gellan gum production by Sphingomonas paucimobilis ATCC 31461 with nonionic surfactants using central composite design.  

PubMed

The effect of nonionic surfactants on gellan production by Sphingomonas paucimobilis was studied by the addition of 0.5, 0.75, 1.0, 1.25 and 1.5 g/l surfactants to shake flask culture. The nonionic surfactants Tween 80, Tween 40 and Triton X-100 improved gellan production by S. paucimobilis, and the maximum yield (10.44 g/l) was obtained with Triton X-100 at 0.75 g/l compared with that of the control fermentation (8.63 g/l) without surfactant. The DO profiles associated with gellan production in a 5-l laboratory fermentor showed higher oxygen and mass transfers during fermentation with surfactant than during control fermentation without surfactant. The addition of surfactant also resulted in a polymer with high viscosity as manifested by its lower acetyl content, than that obtained by control fermentation. A central composite design (CCD) was used to determine the maximum gellan production at optimum values for three process parameters (Triton X-100 concentration, pH, and temperature) each at five levels in a laboratory fermentor. The maximum gellan yield (14.62 g/l) was obtained in a 5-l laboratory fermentor with 1.0 g/l Triton X-100 and at pH 6.0 and temperature 29.6 degrees C. Further studies on the effects of agitation and DOT level demonstrated that the surfactants enhanced oxygen transfer resulting in higher gellan production (27.86 g/l) at higher agitation speed (1000 rpm) and 100% DOT level. PMID:18397769

Arockiasamy, Santhiagu; Banik, Rathindra Mohan

2008-03-01

23

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

24

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

PubMed

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

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

2014-05-01

25

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

26

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

PubMed Central

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

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

2014-01-01

27

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

28

21 CFR 172.665 - Gellan gum.  

Code of Federal Regulations, 2013 CFR

...NW., Washington, DC 20055 (Internet address http://www.nap.edu ), or may be examined at the Center for Food Safety and Applied Nutrition's Library, Food and Drug Administration, 5100 Paint Branch Pkwy., College Park, MD...

2013-04-01

29

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 100 nm; a GA content of 15.6% by dry weight; a saturation magnetization of 93.1 emu\\/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

30

Freeze–thaw 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 freeze–thawing (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

31

Rheological characterization of deacylated\\/acylated gellan films carrying l-(+)-ascorbic acid  

Microsoft Academic Search

Films developed for supporting l-(+)-ascorbic acid (AA), natural antioxidant for the protection of foods, were rheologically evaluated. A film was formulated by mixing gellan gum with its acylated form to attain a higher AA stability and lower non-enzymatic browning. The polymer mixture allowed obtaining a less rigid film, permitting the usage of a lower proportion of glycerol.Mechanical spectra of films

Paula G. León; Stefania Chillo; Amalia Conte; Lía N. Gerschenson; Matteo A. Del Nobile; Ana M. Rojas

2009-01-01

32

Purification and characterization of microbial gellan lyase.  

PubMed Central

Gellan lyase was purified from the culture fluid of soil samples incubated in a medium containing gellan as a sole carbon source. The enzyme was a monomer with a molecular mass of 140 kDa and was most active at pH 7.5 and 45 degrees C. The enzyme was highly specific to gellan and lowered the viscosity of the polymer.

Hashimoto, W; Inose, T; Nakajima, H; Sato, N; Kimura, S; Murata, K

1996-01-01

33

Self-structuring foods based on acid-sensitive low and high acyl mixed gellan systems to impact on satiety  

PubMed Central

This study investigated the in vitro acid-induced gelation of mixed systems of two biopolymers; low acyl and high acyl gellan gum. Rheological and texture analysis showed that these mixed gels displayed textures that lay between the material properties exhibited for the low and high acyl variants. DSC analysis showed that mixtures of the low acyl and high acyl forms exhibit two separate conformational transitions at temperatures coincident with each of the individual biopolymers. Various metabolically relevant pH environments and hydrocolloid concentrations were investigated. These resulted in very different acid gelled structures, which were characterised by texture analysis. The structures of the acid gels were shown to depend upon the pH, hydrocolloid concentration and proportion of each biopolymer used during their production. A selection of these mixed gellan structures were assessed post-production in terms of their response to prolonged exposure to an acidic (pH 1), stomach-like, environment. This resulted in a significant increase in the gel strength, regardless of the biopolymer proportions. The high acyl gellan was less acid-sensitive, and subsequently no evidence of acid gelation was observed with high acyl gellan at a proportion greater than 60% of the total biopolymer. The findings presented here demonstrate that structuring as well as de-structuring of mixed gellan acid gels can be controlled in acidic environments similar to those that are present in the stomach after food consumption.

Bradbeer, Jennifer F.; Hancocks, Robin; Spyropoulos, Fotios; Norton, Ian T.

2014-01-01

34

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

35

Nicotine Gum  

MedlinePLUS

Nicotine chewing gum is used to help people stop smoking cigarettes. Nicotine chewing gum should be used together with a ... support groups, counseling, or specific behavioral change techniques. Nicotine gum is in a class of medications called ...

36

Chain Release Behavior of Gellan Gels  

Microsoft Academic Search

\\u000a The chain release behavior from gellan gels was studied by immersing the gel into water and monitoring the mass loss as a\\u000a function of time. Concentration of released gellan in the external solution was determined for gels of different sizes using\\u000a phenol-sulfuric acid method. The chain release process became faster with increasing total surface area and volume. However\\u000a the concentration

Khandker S. Hossain; Katsuyoshi Nishinari

2009-01-01

37

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

38

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

39

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

40

Process optimization for fabrication of gellan based electrospun nanofibers.  

PubMed

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

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

2014-08-30

41

Vegetable Gums.  

National Technical Information Service (NTIS)

The monograph summarizes the available scientific literature from 1920-1978 related to the safety of vegetable gums. Chemical information, biological data, and biochemical aspects of these compounds are contained in a 103 page summary containing 491 refer...

R. Handler W. Bauer

1978-01-01

42

Thermoresponsive magnetic nanoparticle - Aminated guar gum hydrogel system for sustained release of doxorubicin hydrochloride.  

PubMed

Hydrogel based sustained drug delivery system has evolved as an immense treatment method for solid tumors over the past few decades with long term theranostic ability. Here, we synthesized an injectable hydrogel system comprising biocompatible aminated guar gum, Fe3O4-ZnS core-shell nanoparticles and doxorubicin hydrochloride. We show that amination of guar gum resulted in attraction of water molecules thereby forming the hydrogel without using toxic crosslinking agents. Hydrogel formation was observed at 37°C and is stable up to 95°C. The prepared hydrogel is also stable over a wide pH range. The in vitro studies show that the maximum de-gelation and drug release up to 90% can be achieved after 20 days of incubation. Studies reveal that the drug and the core-shell nanoparticles can be released slowly from the hydrogel to provide the healing and diagnosis of the solid tumor thereby avoiding several drug administrations and total excision of organs. PMID:24906777

Murali, Ragothaman; Vidhya, Ponraj; Thanikaivelan, Palanisamy

2014-09-22

43

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

44

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

Microsoft Academic Search

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

S Bayarri; I Rivas; E Costell; L Durán

2001-01-01

45

Gums and Related Polysaccharides  

NASA Astrophysics Data System (ADS)

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

Bemiller, James N.

46

Sphinganase, a new endoglycanase that cleaves specific members of the gellan family of polysaccharides.  

PubMed Central

A sporeforming gram-positive aerobic bacterium was isolated from soil and shown to secrete an endoglycanase that cleaves the tetrasaccharide backbone structure of specific members within the gellan family of related bacterial exopolysaccharides. We refer to these polysaccharides as sphingans. The structures of the sphingans differ by the type and position of side groups that are attached to the backbone. The new enzyme named sphinganase degrades welan, gellan, deacylated gellan, and polysaccharides S-88, S-7, and S-198. However, the enzyme does not attack rhamsan or polysaccharide NW11. Methods for growing the bacteria, isolating the enzyme, and assaying sphinganase activity are presented, and uses for the enzyme are proposed. Images

Mikolajczak, M J; Thorne, L; Pollock, T J; Armentrout, R W

1994-01-01

47

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

PubMed

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

Murillo-Martínez, María M; Tecante, Alberto

2014-08-01

48

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

PubMed Central

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

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

2012-01-01

49

Thermal behavior of gum arabic in comparison with cashew gum  

Microsoft Academic Search

Thermal behavior of gum arabic and cashew gum, the exudate polysaccharides from Acacia and Anacardium occidentale L., containing different gum\\/water concentrations: 100\\/0, 80\\/20, 60\\/40, 50\\/50, 40\\/60, 20\\/80 and 5\\/95% w\\/w, were studied by differential scanning calorimetry (DSC) and thermogravimetry (TG). DSC thermal profiles for gum arabic with low water content (0–40%) showed an endothermic event at about 90°C (Tonset) and

C. G Mothé; M. A Rao

2000-01-01

50

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

Microsoft Academic Search

Gellan based floating beads of acetohydroxamic acid (AHA) were prepared by the ionotropic gellation me- thod to achieve controlled and sustained drug release for treatment of Helicobacter pylori infection. The prepared beads were evaluated for diameter, surface morphology and encapsulation efficiency. Formulation parameters like concentrations of gellan, chitosan, calcium carbonate and the drug influenced the in vitro drug release charac-

BRAHMESHWAR MISHRA

51

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

52

Gum and Heart Disease  

NSDL National Science Digital Library

Scientists have long noticed a connection between gum disease and heart disease. Now, they've found a key piece of the puzzle. This science update examines what scientists have found linking the total amount of periodontal bacteria in the mouth and blockages in the carotid artery.

Science Update;

2005-04-25

53

Swelling studies of chitosan\\/cashew nut gum physical gels  

Microsoft Academic Search

Gels from chitosan\\/cashew nut gum (CH\\/CNG) were prepared with different chitosan to cashew nut gum ratio and their swelling behaviour was investigated as a function of pH and salt. Infrared and Carbon-13 nuclear magnetic resonance spectroscopy were used to elucidate the gel structure. Swelling in water diminishes sharply when the ratio CH\\/CNG increases. In the presence of Na+ counterions the

Haroldo C. B Paula; Francisco J. S Gomes; Regina C. M de Paula

2002-01-01

54

Stress-strain relationships for gellan gels in tension, compression and torsion  

Microsoft Academic Search

Formulated foods often contain small amounts of polymeric ingredients that interact to form three-dimensional networks which stabilize structure and provide desirable textural quality. One goal of food engineers is to understand how gels are formed and to be able to predict their mechanical properties. We have studied calcium-crosslinked gels of gellan, a polysaccharide recently introduced to the food industry, in

Juming Tang; Marvin A. Tung; John Lelievre; Yanyin Zeng

1997-01-01

55

Grewia gum as a potential aqueous film coating agent. I: Some physicochemical characteristics of fractions of grewia gum  

PubMed Central

Background: Grewia gum has received attention as a polymeric pharmaceutical excipient in the recent times, being employed as a suspending, film coating, mucoadhesive, and binding agent. The low aqueous solubility, however, has limited its characterization and application. Objective: The purpose of this study was to fractionate and evaluate some physicochemical properties of the gum. Materials and Methods: Aqueous dispersion of the gum was treated at 80°C for 30 min in the presence of sodium chloride and was subsequently fractionated by successively centrifuging it at 3445 rpm for 30 min. Skeletal density, solubility, particle size, and rheological as well as thermal characteristics of the fractions were evaluated. The 1H nuclear magnetic resonance (NMR) and near infrared (NIR) profiles of the fractions were also investigated. The solubility of the gum increased up to fourfold while the viscosity decreased from 244 to as low as70 cP at 40 rpm with some fractions. Results: Grewia gum and the fractions showed good thermal stability exhibiting no thermal events, but charred irreversibly at 297°C irrespective of the fraction. The molecular weight averages by weight and by number of the fractions were between 233,100 and 235,000. The 1H nuclear magnetic resonance (NMR) spectra showed broad peaks. The NMR and NIR spectra suggested the presence of –OH and –OCH3 functional groups in this gum. Conclusion: The fractionation improved solubility and facilitated further investigations on its characteristics that may have implication on its processing, application, and optimization as a potential pharmaceutical excipient.

Ogaji, Ikoni J.; Okafor, Ignatius S.; Hoag, Stephen W.

2013-01-01

56

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.

57

The Gum Nebula.  

NASA Technical Reports Server (NTRS)

A historical review of observations on the Gum Nebula is given together with a survey of knowledge on its size, emission features, and dynamics of expansion. The ultraviolet spectrum of Zeta Puppis is examined in terms of features caused by various absorption lines, and radio emission from Vela X is analyzed, together with the effects of nebular plasma on the propagation of radio pulses from pulsars in the Nebula. The density distribution and the possibility of being produced by the Vela X supernova are discussed.

Maran, S. P.

1971-01-01

58

Gum and Heart Disease  

NSDL National Science Digital Library

Over the past ten years, there have been many studies linking gum disease and hardening of the arteries. At first, there were observations that people with poor oral health were more prone to heart disease. More recently, scientists have found clear links between the total amount of periodontal bacteria in the mouth and blockages in the carotid artery. This study proves that at least some of the bacteria manage to escape that fate. This Science Update looks at the research, which leads to the findings presented and offers links to other sources for further inquiry.

American Association for the Advancement of Science (;)

2005-04-25

59

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

60

Thermal studies on natural and modified gums  

Microsoft Academic Search

Various industrial gums (i.e. gum arabic, gum tragacanth, gum xanthan, sodium alginate, chitosan, carboxymethylcellulose, hydroxyethylcellulose, and methylcellulose) were thermally characterized using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) under nitrogen atmosphere. Major thermal transitions as well as activation energies of the major decomposition stages were determined. Gum tragacanth and hydroxyethyl cellulose exhibited the highest (258 kJ\\/mol) and the lowest

M. J Zohuriaan; F Shokrolahi

2004-01-01

61

Solution rheology of mesquite gum in comparison with gum arabic  

Microsoft Academic Search

Commercial samples of mesquite gum and food-grade gum arabic were purified by filtration, alcohol precipitation, and extensive dialysis, and their Theological properties were characterised over the full range of concentrations at which solutions could be prepared (up to ~50% w\\/w). Both gave typical solution-like mechanical spectra, with close Cox-Merz superposition of ? (?g) and ??(?) and only slight shear thinning

F. M. Goycoolea; E. R. Morris; R. K. Richardson; A. E. Bell

1995-01-01

62

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

63

Nanomechanical Testing of Gum Metal  

Microsoft Academic Search

Gum Metal” is a newly developed ?-Ti alloy that, in the cold-worked condition, has exceptional elastic elongation and high\\u000a strength. The available evidence suggests that Gum Metal does not yield until the applied stress approaches the ideal strength,\\u000a and then deforms by mechanisms that do not involve conventional crystal dislocations. To study its behavior, submicron-sized\\u000a pillars of solution-treated and cold-worked

E. A. Withey; J. Ye; A. M. Minor; S. Kuramoto; D. C. Chrzan; J. W. Morris

2010-01-01

64

'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

65

Mind Your Mouth: Preventing Gum Disease  

MedlinePLUS

... External link, please review our exit disclaimer . Subscribe Mind Your Mouth Preventing Gum Disease If you have ... day. search Features Can We Prevent Alzheimer's Disease? Mind Your Mouth Wise Choices Links To Prevent Gum ...

66

21 CFR 172.695 - Xanthan gum.  

Code of Federal Regulations, 2010 CFR

... 2009-04-01 2009-04-01 false Xanthan gum. 172.695 Section 172.695 Food and...Bases and Related Substances § 172.695 Xanthan gum. The food additive xanthan gum may be safely used in food in accordance...

2009-04-01

67

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...Bases and Related Substances § 172.695 Xanthan gum. The food additive xanthan gum may be safely used in food in accordance...

2010-01-01

68

21 CFR 573.1010 - Xanthan gum.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2010-04-01 false Xanthan gum. 573.1010 Section 573.1010 Food and...ANIMALS Food Additive Listing § 573.1010 Xanthan gum. The food additive xanthan gum may be safely used in animal feed as...

2010-04-01

69

21 CFR 573.1010 - Xanthan gum.  

Code of Federal Regulations, 2010 CFR

... 2009-04-01 2009-04-01 false Xanthan gum. 573.1010 Section 573.1010 Food and...ANIMALS Food Additive Listing § 573.1010 Xanthan gum. The food additive xanthan gum may be safely used in animal feed as...

2009-04-01

70

Bacterial exopolysaccharide based magnetic nanoparticles: a versatile nanotool for cancer cell imaging, targeted drug delivery and synergistic effect of drug and hyperthermia mediated cancer therapy.  

PubMed

Microbial exopolysaccharides (EPSs) are highly heterogeneous polymers produced by fungi and bacteria that have garnered considerable attention and have remarkable potential in various fields, including biomedical research. The necessity of biocompatible materials to coat and stabilize nanoparticles is highly recommended for successful application of the same in biomedical regime. In our study we have coated magnetic nanoparticles (MNPs) with two bacterial EPS-mauran (MR) and gellan gum (GG). The biocompatibility of EPS coated MNPs was enhanced and we have made it multifunctional by attaching targeting moiety, folate and with encapsulation of a potent anticancerous drug, 5FU. We have conjugated an imaging moiety along with nanocomposite to study the effective uptake of nanoparticles. It was also observed that the dye labeled folate targeted nanoparticles could effectively enter into cancer cells and the fate of nanoparticles was tracked with Lysotracker. The biocompatibility of EPS coated MNPs and synergistic effect of magnetic hyperthermia and drug for enhanced antiproliferation of cancer cells was also evaluated. More than 80% of cancer cells was killed within a period of 60 min when magnetic hyperthermia (MHT) was applied along with drug loaded EPS coated MNPs, thus signifying the combined effect of drug loaded MNPs and MHT. Our results suggests that MR and GG coated MNPs exhibited excellent biocompatibility with low cell cytotoxicity, high therapeutic potential, and superparamagnetic behavior that can be employed as prospective candidates for bacterial EPS based targeted drug delivery, cancer cell imaging and for MHT for killing cancer cells within short period of time. PMID:24749386

Sivakumar, Balasubramanian; Aswathy, Ravindran Girija; Sreejith, Raveendran; Nagaoka, Yutaka; Iwai, Seiki; Suzuki, Masashi; Fukuda, Takahiro; Hasumura, Takashi; Yoshida, Yasuhiko; Maekawa, Toru; Sakthikumar, Dasappan Nair

2014-06-01

71

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

72

Gummy vs. Gum (Number Pattern)  

NSDL National Science Digital Library

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

Center, Beacon L.

2009-10-13

73

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

...2014-04-01 2014-04-01 false Water-soluble gums, hydrophilic gums...Specific Drug Products § 201.319 Water-soluble gums, hydrophilic gums...have been associated with the ingestion of water-soluble gums, hydrophilic...

2014-04-01

74

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...reason of imports from Austria of xanthan gum provided for in subheading 3913...reason of imports from China of xanthan gum provided for in subheading...

2013-07-19

75

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

PubMed

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

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

2012-10-15

76

The effect of sugars on the retention of ethyl butyrate by gellan gels.  

PubMed

The effect of sucrose, glucose and fructose on the retention of ethyl butyrate by low acyl gellan gels was investigated by static headspace gas chromatography. The air/biopolymer partition coefficient (K) and percentage of retention (R%) were determined. When 5 g of sample were left to equilibrate at 37 °C for 24 h, the obtained results were explained in terms of gel rigidity, as increased rigidity resulted in increased aroma retention. Glucose showed the greatest aroma release among the sugars and resulted in either the same or increased aroma release with increasing concentration. Increasing concentrations of fructose and sucrose did not alter aroma release significantly. For 15 g of sample mass, sucrose exhibited the lowest partition coefficient values among the sugars. The two higher sucrose concentrations resulted in decreased coefficient values. For fructose and glucose, aroma retention decreased with increasing concentration. The percentage of retention values were positive for all sugars, throughout their concentration range and for both experiments. PMID:24679778

Evageliou, Vasiliki; Patsiakou, Anna

2014-08-15

77

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

Code of Federal Regulations, 2010 CFR

...with the ingestion of water-soluble gums, hydrophilic gums...limited to, agar, alginic acid, calcium polycarbophil...drug products containing water-soluble gums, hydrophilic...dosage forms: Capsules, granules, powders,...

2010-04-01

78

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

Code of Federal Regulations, 2010 CFR

...with the ingestion of water-soluble gums, hydrophilic gums...limited to, agar, alginic acid, calcium polycarbophil...drug products containing water-soluble gums, hydrophilic...dosage forms: Capsules, granules, powders,...

2009-04-01

79

Preparation and in vitro antibacterial evaluation of gatifloxacin mucoadhesive gellan system  

PubMed Central

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

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

2010-01-01

80

Alginate and gellan-based edible coatings as carriers of antibrowning agents applied on fresh-cut Fuji apples  

Microsoft Academic Search

Alginate (2% w\\/v) and gellan (0.5% w\\/v)-based edible coatings were formulated to study the effect of glycerol (G) and antibrowning agents (N-acetylcysteine and glutathione) on water vapor resistance (WVR). The ability of the coatings to carry antibrowning agents was investigated following color changes of coated fresh-cut Fuji apples. Selected formulations obtained by a response surface analysis were 1.5% G, 1%

M. A. Rojas-Graü; M. S. Tapia; F. J. Rodríguez; A. J. Carmona; O. Martin-Belloso

2007-01-01

81

Structure of gum arabic in aqueous solution  

Microsoft Academic Search

Gum arabic, a natural polysaccharide derived from exudates of Acacia senegal and Acacia seyal trees, is a commonly used food hydrocolloid. The complex chemical structure of the gum has been widely studied revealing a multifraction ma- terial consisting mainly of a highly branched polysaccharide and a protein-polysac- charide complex (GAGP) as a minor component. This work investigates its mesoscopic structure

Yael Dror; Yachin Cohen; Rachel Yerushalmi-Rozen

2006-01-01

82

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

PubMed

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

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

2011-03-01

83

Problem Solving: Bubble Gum Contest  

NSDL National Science Digital Library

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

Boston, Wghb

2013-01-01

84

Chewing gum moderates the vigilance decrement.  

PubMed

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

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

2014-05-01

85

Synergistic gel formation of xyloglucan/gellan mixtures as sudied by rheology, DSC, and circular dichroism.  

PubMed

The gelation behavior of mixtures of tamarind seed xyloglucan (TSX) and sodium form gellan (Na-G) was investigated. The storage and loss shear moduli, G' and G'', of the mixtures showed that a thermoreversible gel was obtained although each polysaccharide alone did not form a gel at experimental conditions. The viscoelastic behavior of the mixtures showed a gel formation of TSX and Na-G induced by synergistic interaction. This synergistic interaction was also revealed by differential scanning calorimetry (DSC) and circular dichroism. Although TSX alone did not show any peak in DSC curves, mixtures with only a small amount of Na-G, which by itself did not show any peak, showed a single peak. With increasing Na-G content, another peak began to appear at the same temperature at which a peak of Na-G alone appeared. Thermally induced changes in circular dichroism of the mixtures were different from those expected from the individual behavior of TSX and Na-G. PMID:14606892

Nitta, Yoko; Kim, Bo S; Nishinari, Katsuyoshi; Shirakawa, Mayumi; Yamatoya, Kazuhiko; Oomoto, Toshio; Asai, Iwao

2003-01-01

86

Does Your Chewing Gum Lose Its Sweetness?  

NSDL National Science Digital Library

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

87

Welan gum: microbial production, characterization, and applications.  

PubMed

Microbial exopolysaccharides are of high molecular weight, environment friendly valuable natural polymers, having applications in diverse areas such as food industry, pharmaceutical industry, cement systems and cosmetics industries. Welan gum, a microbial product holds an important place among the exopolysaccharides due to its novel properties and potential applications. The biopolymer welan gum is synthesized by the fermentation process mainly by the Alcaligenes sp., and is composed of polymer of tetrasaccharide backbone chain containing l-mannose, l-rhamnose, d-glucose, and d-glucuronic acid. It acts as a thickening, suspending, binding, emulsifying, stabilizing and viscosifying agent. It has important commercial applications in the cement systems. This review is primarily focused on the microbial production, purification, recovery, and the characterization based on the available published literature on the welan gum. Besides this, the biosynthesis and the various process factors affecting the production as well as properties of welan gum and its various applications have also been addressed. PMID:24508918

Kaur, Varinder; Bera, Manav B; Panesar, Parmjit S; Kumar, Harish; Kennedy, J F

2014-04-01

88

Scientific Method Lab Using Bubble Gum  

NSDL National Science Digital Library

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

89

Locust bean gum: a versatile biopolymer.  

PubMed

Biopolymers or natural polymers are an attractive class of biodegradable polymers since they are derived from natural sources, easily available, relatively cheap and can be modified by suitable reagent. Locust bean gum is one of them that have a wide potentiality in drug formulations due to its extensive application as food additive and its recognized lack of toxicity. It can be tailored to suit its demands of applicants in both the pharmaceutical and biomedical areas. Locust bean gum has a wide application either in the field of novel drug delivery system as rate controlling excipients or in tissue engineering as scaffold formation. Through keen references of reported literature on locust bean gum, in this review, we have described critical aspects of locust bean gum, its manufacturing process, physicochemical properties and applications in various drug delivery systems. PMID:23544637

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

2013-05-15

90

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

91

The composition of two Spondias gum exudates  

Microsoft Academic Search

The polysaccharides isolated from Spondias purpurea var. lutea and Spondias cytherea contain galactose, as main component, arabinose, mannose, xylose and rhamnose residues. On the other hand, glucuronic acid and its 4-0-methyl derivative are present in those polysaccharides in contrast to the presence of galacturonic acid reported for other Spondias gums. S. cytherea gum has the highest intrinsic viscosity (63ml\\/g). The

G. L. de Pinto; M. Mart??nez; L. Sanabria; F. Rincón; A. Vera; O. Beltrán; C. Clamens

2000-01-01

92

Mutational analysis of the gum gene cluster required for xanthan biosynthesis in Xanthomonas oryzae pv oryzae.  

PubMed

Genome sequence analysis of Xanthomonas oryzae pv. oryzae has revealed a cluster of 12 ORFs that are closely related to the gum gene cluster of Xanthomonas campestris pv. campestris. The gum gene cluster of X. oryzae encodes proteins involved in xanthan production; however, there is little experimental evidence supporting this. In this study, biochemical analyses of xanthan produced by a defined set of X. oryzae gum mutant strains allowed us to preliminarily assign functions to most of the gum gene products: biosynthesis of the pentasaccharide repeating unit for GumD, GumM, GumH, GumK, and GumI, xanthan polymerization and transport for GumB, GumC, GumE, and GumJ, and modification of the pentasaccharide repeating unit for GumF, GumG, and GumL. In addition, we found that the exopolysaccharides are essential but not specific for the virulence of X. oryzae. PMID:18854951

Kim, Sang-Yoon; Kim, Jeong-Gu; Lee, Byoung-Moo; Cho, Jae-Yong

2009-02-01

93

Xanthan chain length is modulated by increasing the availability of the polysaccharide copolymerase protein GumC and the outer membrane polysaccharide export protein GumB.  

PubMed

Xanthan is a polysaccharide secreted by Xanthomonas campestris that contains pentameric repeat units. The biosynthesis of xanthan involves an operon composed of 12 genes (gumB to gumM). In this study, we analyzed the proteins encoded by gumB and gumC. Membrane fractionation showed that GumB was mainly associated with the outer membrane, whereas GumC was an inner membrane protein. By in silico analysis and specific globomycin inhibition, GumB was characterized as a lipoprotein. By reporter enzyme assays, GumC was shown to contain two transmembrane segments flanking a large periplasmic domain. We confirmed that gumB and gumC mutant strains uncoupled the synthesis of the lipid-linked repeat unit from the polymerization process. We studied the effects of gumB and gumC gene amplification on the production, composition and viscosity of xanthan. Overexpression of GumB, GumC or GumB and GumC simultaneously did not affect the total amount or the chemical composition of the polymer. GumB overexpression did not affect xanthan viscosity; however, a moderate increase in xanthan viscosity was achieved when GumC protein levels were increased 5-fold. Partial degradation of GumC was observed when only that protein was overexpressed; but co-expression of GumB and GumC diminished GumC degradation and resulted in higher xanthan viscosity than individual GumB or GumC overexpression. Compared with xanthan from the wild-type strain, longer polymer chains from the strain that simultaneously overexpressed GumB and GumC were observed by atomic force microscopy. Our results suggest that GumB-GumC protein levels modulate xanthan chain length, which results in altered polymer viscosity. PMID:23089617

Galván, Estela M; Ielmini, María V; Patel, Yamini N; Bianco, María I; Franceschini, Esteban A; Schneider, Jane C; Ielpi, Luis

2013-02-01

94

Anti-malarial effect of gum arabic  

PubMed Central

Background Gum Arabic (GA), a nonabsorbable nutrient from the exudate of Acacia senegal, exerts a powerful immunomodulatory effect on dendritic cells, antigen-presenting cells involved in the initiation of both innate and adaptive immunity. On the other hand GA degradation delivers short chain fatty acids, which in turn have been shown to foster the expression of foetal haemoglobin in erythrocytes. Increased levels of erythrocyte foetal haemoglobin are known to impede the intraerythrocytic growth of Plasmodium and thus confer some protection against malaria. The present study tested whether gum arabic may influence the clinical course of malaria. Methods Human erythrocytes were in vitro infected with Plasmodium falciparum in the absence and presence of butyrate and mice were in vivo infected with Plasmodium berghei ANKA by injecting parasitized murine erythrocytes (1 × 106) intraperitoneally. Half of the mice received gum arabic (10% in drinking water starting 10 days before the day of infection). Results According to the in vitro experiments butyrate significantly blunted parasitaemia only at concentrations much higher (3 mM) than those encountered in vivo following GA ingestion (<1 ?M). According to the in vivo experiments the administration of gum arabic slightly but significantly decreased the parasitaemia and significantly extended the life span of infected mice. Discussion GA moderately influences the parasitaemia and survival of Plasmodium-infected mice. The underlying mechanism remained, however, elusive. Conclusions Gum arabic favourably influences the course of murine malaria.

2011-01-01

95

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

2012-01-01

96

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

PubMed

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

Singh, Sudarshan; Bothara, Sunil B

2014-01-01

97

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

PubMed Central

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

Singh, Sudarshan; Bothara, Sunil B.

2014-01-01

98

Rehabilitating gum arabic systems in Sudan: Economic and environmental implications  

Microsoft Academic Search

The economic and environmental benefits of gum arabic production in the Sudano-Sahelian zone appear attractive. However, the farm-level economics of gum arabic production is complex, and much more needs to be understood about the economic-environmental interactions determining farmers' gum cropping. The following paper explores these issues in Sudan through a crop profitability analysis of gum and other crops combined with

Edward B. Barbier

1992-01-01

99

21 CFR 184.1343 - Locust (carob) bean gum.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Locust (carob) bean gum. 184.1343 Section 184.1343 Food...Affirmed as GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of...

2009-04-01

100

Design, formulation and evaluation of caffeine chewing gum  

PubMed Central

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

Aslani, Abolfazl; Jalilian, Fatemeh

2013-01-01

101

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

102

Corn fiber gum: A potential gum arabic replacer for beverage flavor emulsification  

Microsoft Academic Search

The US food industry would benefit from a domestically produced gum with a dependable supply and consistent quality that can be used for preparing oil-in-water (O-in-W) emulsions, such as citrus oil emulsions for beverages. Corn fiber gum (CFG) is an arabinoxylan (hemicellulose) extracted from the corn kernel pericarp and\\/or endosperm fiber fractions that can possibly fulfill this need. In this

Madhav P. Yadav; David B. Johnston; Arland T. Hotchkiss; Kevin B. Hicks

2007-01-01

103

Rheological behavior of aqueous dispersions of cashew gum and gum arabic: effect of concentration and blending  

Microsoft Academic Search

Rheological properties of cashew gum (CG) and gum arabic (AR), the exudate polysaccharides from Anacardium occidentale L. and Acacia, at different solutions (0.4–50%w\\/v) were studied. The intrinsic viscosity, [?], of CG in water at 20°C was ?0.1dlg?1, while that of AR was ?0.6dlg?1. The apparent viscosity of the unheated and the heated (at 80°C for 30min) CG and AR solutions

C. G Mothé; M. A Rao

1999-01-01

104

UTILIZATION OF MESQUITE ( Prosopis julijlora) GUM AS EMULSION STABILIZING AGENT FOR SPRAY-DRIED ENCAPSULATED ORANGE PEEL OIL  

Microsoft Academic Search

Orange peel oil was microencapsulated. Mesquite gum and its performance for producing spray-dried powders was compared to emulsions prepared with gum arabic. Average oil droplet size of mesquite gum capsules was smaller than that of gum arabic. Emulsions made with mesquite gum showed better stability than those made with gum arabic. Encapsulation capacity of mesquite gum was found to be

César I. Beristain; Eduardo J. Vernon-Carter

1994-01-01

105

Addiction to the nicotine gum in never smokers  

PubMed Central

Background Addiction to nicotine gum has never been described in never smokers or in never users of tobacco. Methods Internet questionnaire in 2004–2006 in a self-selected sample of 434 daily users of nicotine gum. To assess dependence on nicotine gum, we used modified versions of the Nicotine Dependence Syndrome Scale (NDSS), the Fagerström Test for Nicotine Dependence and the Cigarette Dependence Scale. Results Five never smokers used the nicotine gum daily. They had been using the nicotine gum for longer than the 429 ever smokers (median = 6 years vs 0.8 years, p = 0.004), and they had higher NDSS-gum Tolerance scores (median = 0.73 vs = -1.0, p = 0.03), a difference of 1.5 standard deviation units. Two never smokers had never used smokeless tobacco, both answered "extremely true" to: "I use nicotine gums because I am addicted to them", both "fully agreed" with: "after a few hours without chewing a nicotine gum, I feel an irresistible urge to chew one" and: "I am a prisoner of nicotine gum". Conclusion This is to our knowledge the first report of addiction to nicotine gum in never users of tobacco. However, this phenomenon is rare, and although the long-term effect of nicotine gum is unknown, this product is significantly less harmful than tobacco.

Etter, Jean-Francois

2007-01-01

106

ESR spectroscopic properties of irradiated gum Arabic.  

PubMed

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

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

2013-12-01

107

Teaching Measurement and Uncertainty the GUM Way  

NASA Astrophysics Data System (ADS)

This paper describes a course aimed at developing understanding of measurement and uncertainty in the introductory physics laboratory. The course materials, in the form of a student workbook, are based on the probabilistic framework for measurement as recommended by the International Organization for Standardization in their publication Guide to the Expression of Uncertainty in Measurement (GUM).

Buffler, Andy; Allie, Saalih; Lubben, Fred

2008-12-01

108

Xanthan gum: production, recovery, and properties.  

PubMed

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. PMID:14538095

García-Ochoa, F; Santos, V E; Casas, J A; Gómez, E

2000-11-01

109

Environmentally Friendly Green Materials from Plant-Based Resources: Modification of Soy Protein using Gellan and Micro\\/Nano-Fibrillated Cellulose  

Microsoft Academic Search

Fully biodegradable micro\\/nano-composite resins were prepared by reinforcing soy protein concentrate (SPC) with micro\\/nano-fibrillated cellulose (MFC) and then blending with gellan. The composite resins showed excellent mechanical and physical properties under testing conditions. Due to the high aspect ratio of MFC, excellent mechanical properties of MFC and MFC\\/SPC interfacial properties, the SPC (100 parts) reinforced with glycerol (1.5 parts) and

Xiaosong Huang; Anil N. Netravali

2008-01-01

110

Biodegradation of Xanthan Gum by Bacillus sp.  

PubMed

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. PMID:16346068

Cadmus, M C; Jackson, L K; Burton, K A; Plattner, R D; Slodki, M E

1982-07-01

111

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

112

Linear Mixed Models: Gum and Beyond  

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

113

Rheological characteristics of food gum (Cissus populnea)  

Microsoft Academic Search

The rheological characteristics (consistency and flow behavior indices) of food gum (Cissus populnea) exudates obtained from the fresh leaves and stem as well as dried leaves and stem were determined at 20, 30, 40, 50 and 60°C using a rotational viscometer at shear rates of 0.1, 0.2, 0.5, 1.0 and 1.5 rpm for effective design and simulation of its momentum

Joseph Shi-an Alakali; Simon Verlumun Irtwange; Moses Mkavga

114

76 FR 44811 - Carboxymethyl Guar Gum Sodium Salt and Carboxymethyl-Hydroxypropyl Guar; Exemption From the...  

Federal Register 2010, 2011, 2012, 2013

...carboxymethyl guar gum sodium salt (CAS Reg. No...thicker/drift reduction agent) in pesticide...carboxymethyl guar gum sodium salt and carboxymethyl...Carboxymethyl guar gum sodium Without limitation...Thicker/drift reduction agent. salt (CAS Reg....

2011-07-27

115

78 FR 33354 - Xanthan Gum From Austria: Final Determination of Sales at Less Than Fair Value  

Federal Register 2010, 2011, 2012, 2013

...Administration [A-433-811] Xanthan Gum From Austria: Final Determination...AD'') investigation of xanthan gum from Austria.\\1\\ On March 4...Department has determined that xanthan gum from Austria is being, or is...

2013-06-04

116

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

PubMed

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

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

2008-05-01

117

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

PubMed

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-His-Ser-Pro-Pro-Pro-Pro-Leu-Ser-Pro-Ser-Pro-Thr-Pro-Thr-Pro-Pro-Leu, in which most of the Pro residues were posttranslationally modified to hydroxyproline (Hyp). (GA)(8) was expressed as a green fluorescent protein (GFP) fusion protein targeted to the culture medium, (GA)(8)GFP. The culture of the transgenic cells in a 5-L bioreactor showed that the production of (GA)(8)GFP was cell growth-associated. The extracellular yield of (GA)(8)GFP was 116.8 mg/L after 14 days of culture and accounted for 87% of the total fusion protein expressed. (GA)(8)GFP was purified from the culture medium by a combination of hydrophobic interaction, gel permeation, and reversed phase chromatography. Biochemical characterization indicated that the amino acid composition of the (GA)(8) module, after removal of GFP by proteolysis, was virtually identical to that of predicted by the GAGP consensus sequence and that carbohydrate, which occurred as arabinogalactan polysaccharides and small oligoarabinosides O-linked through the Hyp residues, accounted for 84% of the molecules' dry weight. Functional assays showed that (GA)(8) exhibited low viscosity in aqueous solution similar to native GAGP. However, neither GFP alone nor the (GA)(8) module could emulsify orange oil. However, the fusion protein (GA)(8)GFP possessed 1.28-fold better emulsification properties than native GAGP. This work demonstrates the feasibility and potential of a synthetic gene approach to the de novo design of novel glycoprotein-based gums and emulsifiers. PMID:15818563

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

2005-06-01

118

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

PubMed

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

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

2014-03-01

119

When to feed on gums: Temporal patterns of gummivory in wild tamarins,Saguinus mystaxand Saguinus fuscicollis(Callitrichinae)  

Microsoft Academic Search

This study examines the temporal patterning of gum feeding in two species of sympatric tamarin monkeys, Saguinus mystax and Saguinus fuscicollis, during the diurnal activity period. The number and duration of visits to gum sources and number of gum feeding records are used as parameters to analyze the gum feeding itinerary. Both visits to gum sources and gum feeding records

Eckhard W. Heymann; Andrew C. Smith

1999-01-01

120

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

PubMed

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

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

2014-08-01

121

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

Microsoft Academic Search

The mechanism of ixodid tick (Acari: Ixodidae) repellency by gum haggar, a resin produced by Commiphora holtziana (Burseraceae), was investigated by evaluating activity against the cattle tick, Boophilus microplus. In an arena bioassay, a hexane extract of the resin of C. holtziana exhibited a repellent effect lasting up to 5h. The hydrocarbon fraction of the resin extract was shown to

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

2008-01-01

122

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

PubMed

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

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

2012-12-01

123

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

124

Carboxymethyl gum kondagogu: synthesis, characterization and evaluation as mucoadhesive polymer.  

PubMed

The objective of the study was to modify gum kondagogu by carboxymethylation and to evaluate it for potential pharmaceutical applications. Carboxymethylation of gum kondagogu was carried out by reacting gum kondagogu with monochloroacetic acid under alkaline conditions. The results of characterization studies revealed that carboxymethylation of gum kondagogu increases its degree of crystallinity and surface roughness, reduces its viscosity and improves its mucoadhesive properties. Further, carboxymethyl gum kondagogu was explored for pharmaceutical applications by formulating ionotropically gelled beads using metformin as the model drug and calcium chloride as cross-linking agent. Ex vivo bioadhesion study conducted using isolated chick-ileum by wash-off test revealed bioadhesion of >80% over a period of 24 h. It was observed that increasing the concentration of cross-linking agent increases the % drug entrapment and reduces the release rate. The beads were found to release the drug by Fickian-diffusion mechanism and following zero-order release kinetics. PMID:24751087

Kumar, Ashok; Ahuja, Munish

2012-09-01

125

Mechanical Characteristics of Spectacle Frames Made of Gum Metal  

NASA Astrophysics Data System (ADS)

Most spectacle frames are now made of titanium alloy. Recently, however, frames made of gum metal have become available. Gum metal is a new material having a low Young's modulus, high strength and high elastic deformation. The effectiveness of these spectacle frames, however, has not yet been mechanically evaluated. In this study, by using the recently proposed optical 3D shape measurement method, the deformation behavior of full-rim and rimless spectacle frames, made of gum metal and available on the market, were compared with that of conventional titanium frames. In addition, CAD models of these frames were created and their mechanical characteristics were evaluated in detail by the finite element method. Consequently, the gum metal frames were found more comfortable to wear than titanium ones. However, the rimless type of gum metal frames allowed more load to reach the front than did the titanium frames, causing lens damage due to stress concentration at the screws.

Kaneko, Hiroshi; Kakunai, Satoshi; Higa, Masaru; Nishimura, Jun

126

Evaluation of Sterculia foetida Gum as Controlled Release Excipient  

PubMed Central

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 ?m) 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 ?m. 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.

Poddar, Sushilkumar Sharatchandra; Abdul, Shajahan; Savant, Gaurav

2008-01-01

127

Design, formulation and evaluation of nicotine chewing gum  

PubMed Central

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

Aslani, Abolfazl; Rafiei, Sahar

2012-01-01

128

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

Microsoft Academic Search

A comparison between the fine structural features of exudate gum from mesquite (Prosopis spp.) indigenous to NW Mexico and commercial gum arabic from Acacia spp. was achieved by means of immunological techniques. Their functional properties were compared from the ability to form oil-in-water emulsions and encapsulate cold press orange peel essential oil by spray drying. Fine comparison of the antigenic

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

1997-01-01

129

Gellan co-polysaccharide micellar solution of budesonide for allergic anti-rhinitis: An in vitro appraisal.  

PubMed

The aim of this study was to design a novel amphiphilic co-polysaccharide for the development of anti-rhinitis micellar solution of budesonide. Herein, a long alkyl chain (C18) was successfully grafted onto gellan polysaccharide by etherification reaction. The dispersion of co-polysaccharide in water led to formation of spherical, nanomicellar structures. Depending upon the co-polysaccharide:drug weight ratio (1:1, 1:2 and 1:3), a maximum drug loading (>95%) was noted at the lowest level. The nanomicelles were in the range of 371-750nm and showed negative zeta potential (-48.3 to -67.2mV) values indicating their stability in aqueous system. They exhibited a longer dissolution profile in simulated nasal fluid (pH 5.5). The dissolution efficiency (39.79±0.93%) was maximal at the lowest polymer: drug ratio in 6h. The drug release was found to follow first order kinetic model. Korsmeyer-peppas modeling of in vitro drug release data indicated that besides simple diffusion, no other physical phenomenon was involved in the event of drug release from the nanostructures. Differential scanning calorimetry analysis suggested some degree of physical incompatibility; however Infrared spectroscopy revealed chemical compatibility between drug and co-polysaccharide. Thus, the co-polysaccharide micellar system offers a splendid outlook in controlled intranasal delivery of budesonide for the symptomatic relief of anti-rhinitis. PMID:24820153

Maiti, Sabyasachi; Chakravorty, Amrita; Chowdhury, Moumita

2014-07-01

130

Statistical evaluation of influence of xanthan gum and guar gum blends on dipyridamole release from floating matrix tablets.  

PubMed

The present investigation explored the use of xanthan gum and guar gum for development of floating drug delivery system of dipyridamole using factorial design approach. The content of polymer blends (X(1)) and ratio of xanthan gum to guar gum (X(2)) were selected as independent variables. The diffusion exponent (n), release rate constant (k), percentage drug release at 1 hr (Q(1)) and 6 hr (Q(6)) were selected as dependent variables. Tablets of all batches had desired buoyancy characteristics. Multiple regression analysis with two way ANOVA revealed that both the factors had statistically significant influence on the response studied (p<0.05). Results of Tukey test showed the relative contribution of each level of different factors for the response studied. It was concluded that the ratio of xanthan to gaur gum had equal or dominant role as controlling factor on kinetics of drug release compared to content of polymer blends. PMID:17454065

Patel, Viral F; Patel, Natavarlal M

2007-03-01

131

The amino acid composition of the proteinaceous component of gum arabic (Acacia Senegal (L.) Willd.)  

Microsoft Academic Search

The exudate from Acacia Senegal (gum arabic) is a proteinaceous polysaccharide, the protein content ranging from ca. 1–5% to 3% for samples from different producing areas. The data presented for the proteinaceous components of eight bulk commercial gum arabic samples, and for eleven gum specimens secured from Acacia Senegal trees growing at various locations in the main Sahelian gum?producing areas,

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

1985-01-01

132

The identification of Combretum gums which are not permitted food additives, II  

Microsoft Academic Search

Combretum gums, readily available at low prices in East and West Africa, may be offered for sale as ‘gum arabic’. Vigilance is necessary to detect such misrepresentations because Combretum gums differ greatly from gum arabic (Acacia Senegal (L.) Willd.) in terms of quality, solution properties and value. Moreover, because there is no toxicological evidence for their safety in use, Combretum

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

1990-01-01

133

Promoter analysis of the Xanthomonas campestris pv. campestris gum operon directing biosynthesis of the xanthan polysaccharide.  

PubMed Central

The Xanthomonas campestris gum gene cluster is composed of 12 genes designated gumB, -C, -D, -E, -F, -G, -H, -I, -J, -K, -L, and -M. The transcriptional organization of this gene cluster was analyzed by the construction of gum-lacZ transcriptional fusions in association with plasmid integration mutagenesis. This analysis, coupled with primer extension assays, indicated that the gum region was mainly expressed as an operon from a promoter located upstream of the first gene, gumB.

Katzen, F; Becker, A; Zorreguieta, A; Puhler, A; Ielpi, L

1996-01-01

134

Material and tableting properties of Azadirachta indica gum with reference to official acacia gum.  

PubMed

This study determined the material and tableting properties of Azadirachta indica gum (NMG) relative to acacia gum (ACA). The morphological properties were assessed with size and shape factors of aspect ratio, roundness, irregularity and equivalent-circle-diameter. The tableting properties of the gums were determined using compressional characteristics, tensile strength (TS), brittle fracture index (BFI) and crushing-strength-friability/disintegration-time ratio (CSFR/DT). The results suggest that NMG possesses larger, irregular and more elongated particles than ACA. The onset and amount of plastic deformation occurring in NMG was faster and higher, respectively, than in ACA. The result shows that, although ACA tablets were stronger, their tendency to cap/laminate was higher than in NMG tablets. The NMG tablets possess lower DT than those of ACA, while the CSFR/DT result suggests that a better balance exists between the strength and weakness of NMG tablets. The study concluded that NMG can be a useful excipient in tablet formulation. PMID:24779199

Ogunjimi, Abayomi T; Alebiowu, Gbenga

2014-01-01

135

Hydrophobic derivatives of guar gum hydrolyzate and gum Arabic as matrices for microencapsulation of mint oil.  

PubMed

Guar gum hydrolyzate (GGH) modified with n-octenyl succinic anhydride (OSA) and oleic acid having induced hydrophobicity was evaluated for encapsulation of mint oil and compared with gum Arabic (GA) and GA-OSA as wall material. Spray dried microcapsules prepared with these wall materials were evaluated for qualitative changes by principal component analysis and for percent retention of mint oil during 8-week storage. Results revealed that microcapsules with GGH-OSA and GGH-oleate showed slightly lower retention of mint oil as compared to GA. GA-OSA microcapsules showed better retention of mint oil than GA itself, as observed from the t1/2, the time required for the mint oil to come down to 50% of its original content. The t1/2 of mint oil in microcapsules of GA, GGH-oleate, GGH-OSA and GA-OSA was 26.12, 23.50, 24.11 and 29.67 weeks, respectively. The results suggested that GGH-OSA has the potential to replace gum Arabic for encapsulation of mint oil. PMID:23618256

Sarkar, Shatabhisa; Gupta, Sumit; Variyar, Prasad S; Sharma, Arun; Singhal, Rekha S

2013-06-01

136

THE CHEMICAL CHARACTERIZATION OF THE TEST ARTICLE USED IN TOXICOLOGICAL STUDIES OF GUM ARABIC (ACACIA SENEGAL (L.) WILLD)  

Microsoft Academic Search

The sample of commercial gum arabic used as the “Test Article” in recent toxicological studies has been characterized chemically. Comparative analytical data, presented for seven other commercial gum arabic samples, and for five specimens of gum collected from authenticated Acacia Senegal trees in several gum producing countries, indicate that the Test Article is a fair, average representative sample of gum

D. M. W. ANDERSON; M. M. E. BRIDGEMAN; J. G. K. FARQUHAR; C. G. A. McNAB

1983-01-01

137

Evaluation of a Treatment Approach Combining Nicotine Gum with Self-Guided Behavioral Treatments for Smoking Relapse Prevention.  

ERIC Educational Resources Information Center

Randomly assigned 1,218 smokers to cells in 4 (nicotine gum delivered ad lib, fixed regimen nicotine gum, placebo gum, no gum) x 3 (self-selected relapse prevention modules, randomly administered modules, no modules) design. Subjects receiving nicotine gum were more likely to be abstinent at 2- and 6-month followups. Fixed regimen accounted for…

Killen, Joel D.; And Others

1990-01-01

138

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

139

GRAS (Generally Recognized as Safe) Food Ingredients: Gum Arabic.  

National Technical Information Service (NTIS)

The report summarizes all available scientific data related to the 'safety' of gum arabic as a food ingredient. The period of the literature search covered is 1920 to 1972, and the monograph summarizes the chemical information, biological data, and bioche...

1972-01-01

140

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

National Technical Information Service (NTIS)

The report summarizes all available scientific data related to the safety of gum arabic as a food ingredient. The period of the literature search covered is 1920 to 1972, and the monograph summarizes the chemical information, biological data, and biochemi...

1972-01-01

141

High-Gum-Yielding Slash Plines Survive and Grow Well.  

National Technical Information Service (NTIS)

Plantings in Georgia and Florida were established with slash pine seedlings of three genetic types: selections improved for high gum yield (IHGY), selections with improved growth and form (IGF), and commercial stock (CS). Under adverse environmental condi...

C. R. Gansel S. V. Kossuth W. J. Peters

1982-01-01

142

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

2013-04-01

143

GUM Analysis for TIMS and SIMS Isotopic Ratios in Graphite  

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.

Heasler, Patrick G.; Gerlach, David C.; Cliff, John B.; Petersen, Steven L.

2007-04-01

144

Natural polymers, gums and mucilages as excipients in drug delivery.  

PubMed

Use of natural polymers, gums and mucilages in drug delivery systems has been weighed down by the synthetic materials. Natural based excipients offered advantages such as non-toxicity, less cost and abundantly availablity. Aqueous solubility of natural excipients plays an important role in their selection for designing immediate, controlled or sustained release formulations. This review article provide an overview of natural gum, polymers and mucilages as excipients in dosage forms as well as novel drug delivery systems. PMID:23457960

Kumar, Shobhit; Gupta, Satish Kumar

2012-01-01

145

New structural features of Spondias purpurea gum exudate  

Microsoft Academic Search

Spondias purpurea L. (Anacardiaceae), disseminated in Venezuela, produces a polysaccharide gum constituted by galactose (59%), arabinose (9%), mannose (2%), xylose (2%), rhamnose (2%) and uronic acids (26%). It also contains a proteinaceous material (2%). The original gum was subjected to two successive Smith-degradation process to obtain polysaccharide II. Application of 2D-NMR techniques, including COSY, HMQC and HMBC, to the original

M. Martínez; G. León de Pinto; M. Bozo de González; J. Herrera; H. Oulyadi; L. Guilhaudis

2008-01-01

146

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

147

GumTree—An integrated scientific experiment environment  

NASA Astrophysics Data System (ADS)

GumTree is an open source and multi-platform graphical user interface for performing neutron scattering and X-ray experiments. It handles the complete experiment life cycle from instrument calibration, data acquisition, and real time data analysis to results publication. The aim of the GumTree Project is to create a highly Integrated Scientific Experiment Environment (ISEE), allowing interconnectivity and data sharing between different distributed components such as motors, detectors, user proposal database and data analysis server. GumTree is being adapted to several instrument control server systems such as TANGO, EPICS and SICS, providing an easy-to-use front-end for users and simple-to-extend model for software developers. The design of GumTree is aimed to be reusable and configurable for any scientific instrument. GumTree will be adapted to six neutron beam instruments for the OPAL reactor at ANSTO. Other European institutes including ESRF, ILL and PSI have shown interest in using GumTree as their workbench for instrument control and data analysis.

Lam, Tony; Hauser, Nick; Götz, Andy; Hathaway, Paul; Franceschini, Fredi; Rayner, Hugh; Zhang, Lidia

2006-11-01

148

78 FR 13379 - Xanthan Gum from Austria and China; Scheduling of the Final Phase of an Antidumping Investigation  

Federal Register 2010, 2011, 2012, 2013

...731-TA-1202-03 (Final)] Xanthan Gum from Austria and China; Scheduling...from Austria and/or China of xanthan gum, provided for in subheading 3913...the subject merchandise as Adry xanthan gum, whether or not coated or...

2013-02-27

149

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...of this investigation covers dry xanthan gum, whether or not coated or...

2013-01-10

150

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

151

Investigations on interpolymer complexes of cationic guar gum and xanthan gum for formulation of bioadhesive films  

PubMed Central

The present study was aimed at evaluating the possible use of inter polymer complexed (IPC) films of xanthan gum (XG) and cationic guar gum (CGG) for formulating domperidone bioadhesive films. Formation of bonds between –COO¯ groups of XG and –N+(CH3)3 groups of CGG was evident in the FTIR spectra of IPC films. Bioadhesive strength of the films was evaluated employing texture analyser. Water uptake studies indicated swelling to be a function of XG concentration in the interpolymer complexes. The bioadhesive films were found to possess neutral pH. In vitro drug release studies and residence time studies indicated that the film comprising CGG:XG (80:20) released 98% of domperidone in 8 h and exhibited a residence time of approximately 8 h. Enhanced bioavailability of domperidone was observed from bioadhesive films as compared to orally administered conventional tablets. Overall, the findings suggest that IPC films of XG and CGG, exhibiting desired bioadhesive strength and enhanced bioavailability of domperidone, can be prepared.

Singh, M.; Tiwary, A.K.; Kaur, G.

2010-01-01

152

Studies on gum of Moringa oleifera for its emulsifying properties  

PubMed Central

Background: Emulsion has been a form of presenting water insoluble substances for a long period of time. Now a day, it has been a way of presenting various intravenous additives and diagnostic agents in X-ray examinations. Various substances can be used as emulsifying agent, which can be operationally defined as a stabilizer of the droplets formed of the internal phase. Materials and Methods: Gum from Moringa oleifera was evaluated for its emulsifying properties. Castor oil emulsions 30 percent (o/w), containing 2 to 4% Moringa oleifera gum was prepared. Emulsions containing equivalent concentration of acacia were also prepared for comparison. All the emulsions prepared were stored at room temperature and studied for stability at various time intervals for 8 weeks. The prepared emulsions were evaluated for creaming rate, globule size and rate of coalescence. 23 factorial design was chosen to investigate the effects of centrifugation, pH, temperature changes and electrolytes on the creaming rate and globule size. Results: The results of the investigations show that the gum of Moringa oleifera possesses better emulsifying properties as compared to gum acacia. Conclusion: Gum of Moringa oleifera could be used in pharmaceutical and non-pharmaceutical preparation.

Panda, Dibya Sundar

2014-01-01

153

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

154

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

Code of Federal Regulations, 2013 CFR

...Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GUM AND WOOD CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Gum Rosin and Turpentine Subcategory § 454.20 Applicability;...

2013-07-01

155

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

Microsoft Academic Search

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

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

1993-01-01

156

Comparison of methods to analyze time–intensity curves in a corn zein chewing gum study  

Microsoft Academic Search

Nine panelists participated in a time–intensity (T–I) study to evaluate the taste, texture and aroma qualities of corn zein gum compared to synthetic gum samples. Four corn zein gum samples varying in type of plasticizer, and two synthetic gum samples were evaluated. Two different methods were used to analyze T–I curves, grouping panelists with similar individual curves and the enhanced

B. A. McGowan; S.-Y. Lee

2006-01-01

157

Elicitation of guggulsterone production in cell cultures of Commiphora wightii by plant gums  

Microsoft Academic Search

Plant gum as an elicitor for guggulsterone production in cell cultures of Commiphora wightii is reported for the first time. Guggulsterone production increased 2.4 fold in the cell cultures by gum Arabic (100 mg l?1), while mesquite gum elicited 2 fold. The cells treated with gum Arabic at 7th and 9th day accumulated enhanced guggulsterones\\u000a within 24 h, which increased further up to

Suchismita Dass; K. G. Ramawat

2009-01-01

158

Effects of xanthan, guar, carrageenan and locust bean gum addition on physical, chemical and sensory properties of meatballs.  

PubMed

This study evaluated the effects of xanthan gum, guar gum, carrageenan and locust bean gum on physical, chemical and sensory properties of meatballs. Meatball samples were produced with three different formulations including of 0.5, 1, and 1.5% each gum addition and gum added samples were compared with the control meatballs. Physical and chemical analyses were carried out on raw and cooked samples separately. Moisture contents of raw samples decreased by addition of gums. There were significant decreases (p?gum when compared with control. Ash contents and texture values increased with gum addition to meatballs. Meatball redness decreased with more gum addition in raw and cooked meatball samples, which means that addition of gums resulted in a lighter-coloured product. According to sensory analysis results, locust bean gum added (1%) samples were much preferred by the panelists. PMID:24803701

Demirci, Zeynep Ozben; Y?lmaz, Ismail; Demirci, Ahmet ?ukru

2014-05-01

159

Evidence for a role for the gumB and gumC gene products in the formation of xanthan from its pentasaccharide repeating unit by Xanthomonas campestris.  

PubMed

The biosynthesis of the extracellular polysaccharide xanthan in Xanthomonas campestris pv. campestris is directed by a cluster of 12 genes, gumB-gumM. Several xanthan-deficient mutants of the wild-type strain 8004 have previously been described which carry Tn5 insertions in this region of the chromosome. Here it is shown that the transposon insertion in one of these mutants, strain 8397, is located 15 bp upstream of the translational start site of the gumB gene. EDTA-treated cells of strain 8397 were able to synthesize the lipid-linked pentasaccharide repeating unit of xanthan from the three nucleotide sugar donors (UDP-glucose, GDP-mannose and UDP-glucuronic acid) but were unable to polymerize the pentasaccharide into mature xanthan. A subclone of the gum gene cluster carrying gumB and gumC restored xanthan production to strain 8397 to levels approximately 28% of the wild-type. In contrast, subclones carrying gumB or gumC alone were not effective. These results are discussed with reference to previous speculations, based on computer analysis, that gumB and gumC are both involved in the translocation of xanthan across the bacterial membranes. PMID:9639919

Vojnov, A A; Zorreguieta, A; Dow, J M; Daniels, M J; Dankert, M A

1998-06-01

160

Hybrid modeling of xanthan gum bioproduction in batch bioreactor.  

PubMed

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

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

2011-10-01

161

Cigarette and nicotine chewing gum toxicity in children.  

PubMed

A prospective review of 51 cases of tobacco ingestion and 5 cases of nicotine resin chewing gum exposure was conducted to evaluate the incidence and degree of toxicity caused by these products in children. A dose-response relationship was observed for cigarette exposures. Nine of 10 children ingesting more than one cigarette or three cigarette butts developed signs or symptoms, while 12 of 24 ingesting lesser amounts became symptomatic (P less than 0.01). Severe symptoms (e.g. limb jerking and unresponsiveness) were only seen with the larger amounts. Nicotine resin gum produced toxicity in 4 of 5 children who chewed 1/2 to 4 pieces. Agitation, lethargy, tachycardia, hypotension, abdominal pain, and vomiting were seen within 30 min of exposure to the gum. PMID:3346035

Smolinske, S C; Spoerke, D G; Spiller, S K; Wruk, K M; Kulig, K; Rumack, B H

1988-01-01

162

Origin of substantial plastic deformation in Gum Metals  

NASA Astrophysics Data System (ADS)

The elastic property and structure of dislocation in Gum Metal are investigated by anisotropic elastic theory and high-resolution transmission electron microscopy (HRTEM). The results show that the elastic energy coefficients for the 1/2<111> perfect dislocations nearly equal to zero as the shear modulus along <111>{110}, {112}, {123} when the valence electron number e/a reaches 4.2, which implies a low intrinsic critical resolved shear stress for dislocation glide. HRTEM observations further revealed 70.53° dislocations in Gum Metal after severe cold working. The substantial plastic deformation is considered to originate from the conventional dislocation mechanism, rather than from the dislocation-free mechanism in Gum Metals.

Xing, H.; Sun, J.; Yao, Q.; Guo, W. Y.; Chen, R.

2008-04-01

163

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

Microsoft Academic Search

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

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

2001-01-01

164

Synthesis and characterization of novel guar gum hydrogels and their use as Cu 2+ sorbents  

Microsoft Academic Search

To prepare novel hydrogels for use in water technologies, guar gum was subjected to acid hydrolysis. The depolymerized guar gum obtained there from and the native guar gum were oxidized to their respective polycarboxylic forms using NOx as oxidant. All these polymers were crosslinked with N,N-methylenebisacrylamide, and were used as Cu2+ sorbents. The candidate hydrogel exhibiting the highest uptake was

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

2009-01-01

165

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

Microsoft Academic Search

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

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

2008-01-01

166

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

PubMed Central

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

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

2012-01-01

167

Metabolic Effects of Nicotine Gum and Cigarette Smoking: Potential Implications for Postcessation Weight Gain?  

ERIC Educational Resources Information Center

Twenty smoking women participated in nicotine gum and smoking administration, after which resting energy expenditures (REEs) were measured. Results indicated acute increase in REE for both nicotine gum and cigarettes. Metabolic rates for nicotine gum slowly returned to baseline; rates for cigarettes quickly fell significantly below baseline.…

Klesges, Robert C.; And Others

1991-01-01

168

Locust bean gum: Exploring its potential for biopharmaceutical applications  

PubMed Central

Polysaccharides have been finding, in the last decades, very interesting and useful applications in the biomedical and, specifically, in the biopharmaceutical field. Locust bean gum is a polysaccharide belonging to the group of galactomannans, being extracted from the seeds of the carob tree (Ceratonia siliqua). This polymer displays a number of appealing characteristics for biopharmaceutical applications, among which its high gelling capacity should be highlighted. In this review, we describe critical aspects of locust bean gum, contributing for its role in biopharmaceutical applications. Physicochemical properties, as well as strong and effective synergies with other biomaterials are described. The potential for in vivo biodegradation is explored and the specific biopharmaceutical applications are discussed.

Dionisio, Marita; Grenha, Ana

2012-01-01

169

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.; Wübbeler, G.; Elster, C.

2011-10-01

170

Production of xanthan gum by Sphingomonas bacteria carrying genes from Xanthomonas campestris.  

PubMed

Twelve genes coding for assembly, acetylation, pyruvylation, polymerization, and secretion of the polysaccharide xanthan gum are clustered together on the chromosome of the bacterium Xanthomonas campestris. These genes (gumBCDEFGHIJKLM) are sufficient for synthesis of xanthan gum when placed in bacteria from a different genus, Sphingomonas. The polysaccharide from the recombinant microorganism is largely indistinguishable, structurally and functionally, from native xanthan gum. These results demonstrate that a complex pathway for biosynthesis of a specific polysaccharide can be acquired by a single inter-generic transfer of genes between bacteria. This suggests the biological and commercial feasibility of synthesizing xanthan gum or other polysaccharides in non-native hosts. PMID:9366091

Pollock, T J; Mikolajczak, M; Yamazaki, M; Thorne, L; Armentrout, R W

1997-08-01

171

1D- and 2D-NMR spectroscopy studies of the polysaccharide gum from Spondias purpurea var. lutea  

Microsoft Academic Search

Spondias purpurea var. lutea (Anacardiaceae) trees located in Venezuela, South America, produce a clear gum very soluble in water. The polysaccharide, from this gum, contains galactosyl, arabinosyl, xylosyl, rhamnosyl and uronic acid residues. Degraded gums A and B were prepared by mild acid hydrolysis and Smith degradation, respectively. Application of 1D- and 2D-NMR spectroscopy to the original gum and its

Omaira Gutiérrez de G; Maritza Mart??nez; Lilian Sanabria; Gladys León de Pinto; J. Manuel Igartuburu

2005-01-01

172

UTILIZATION OF OKRA GUM FOR TREATMENT OF TANNERY EFFLUENT  

Microsoft Academic Search

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

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

2003-01-01

173

Production of High-Pyruvate Xanthan Gum on Synthetic Medium.  

National Technical Information Service (NTIS)

A high-pyruvate xanthan gum, substantially free of insolubles and undesirable coloration, is produced by fermentation of Xanthomonas campestris on a carbohydrate-containing nutrient medium having (NH4)2HPO4 at a level of at least 0.15% as the primary nitr...

M. C. Cadmus C. A. Knutson

1978-01-01

174

Effects of Gum Arabic on Lipase Interfacial Binding and Activity  

Microsoft Academic Search

We investigated the surface behavior of gum Arabic (GA) as well as its effects on the lipolytic activity of human pancreatic lipase (HPL) and Humicola lanuginosa lipase (HLL), using emulsions of triacylglycerols (TAG) with various chain lengths. The effects of GA on the interfacial binding of HPL were also investigated. In the presence of 4 mM sodium taurodeoxycholate (NaTDC), GA

Ali Tiss; Frédéric Carrière; Robert Verger

2001-01-01

175

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

176

Method for inhibiting gum formation in liquid hydrocarbon mediums  

Microsoft Academic Search

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.

1990-01-01

177

Functionality of gum arabic. Fractionation, characterization and evaluation of gum fractions in citrus oil emulsions and model beverages  

Microsoft Academic Search

Gum arabic, the exudate from Acacia Senegal, has been fractionated by size exclusion chromatography (SEC) and by hydrophobic interaction chromatography (HIC). Five SEC fractions and two HIC fractions have been evaluated in orange oil emulsions and also in model beverages. Comparisons were made on an equal nitrogen and\\/or equal weight basis to controls. Amino acid and other analyses of the

Apurba K. Ray; Philip B. Bird; Guillermo A. Iacobucci; Benjamin C. Clark Jr

1995-01-01

178

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

PubMed

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

Varshosaz, Jaleh; Tavakoli, Naser; Kheirolahi, Fatemeh

2006-01-01

179

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

180

Disruption of Xylella fastidiosa CVC gumB and gumF genes affects biofilm formation without a detectable influence on exopolysaccharide production.  

PubMed

Xylella fastidiosa causes citrus variegated chlorosis (CVC), a destructive disease of citrus. Xylella fastidiosa forms a biofilm inside plants and insect vectors. Biofilms are complex structures involving X. fastidiosa cells and an extracellular matrix which blocks water and nutrient transport in diseased plants. It is hypothesized that the matrix might be composed of an extracellular polysaccharide (EPS), coded by a cluster of nine genes closely related to the xanthan gum operon of Xanthomonas campestris pv. campestris. To understand the role of X. fastidiosa gum genes on biofilm formation and EPS biosynthesis, we produced gumB and gumF mutants. Xylella fastidiosa mutants were obtained by insertional duplication mutagenesis and recovered after triply cloning the cells. Xylella fastidiosa gumB and gumF mutants exhibited normal cell characteristics; typical colony morphology and EPS biosynthesis were not altered. It was of note that X. fastidiosa mutants showed a reduced capacity to form biofilm when BCYE was used as the sustaining medium, a difference not observed with PW medium. Unlike X. campestris pv. campestris, the expression of the X. fastidiosa gumB or gumF genes was not regulated by glucose. PMID:16553859

Souza, Leonardo C A; Wulff, Nelson A; Gaurivaud, Patrice; Mariano, Anelise G; Virgílio, Andréa C D; Azevedo, João L; Monteiro, Patrícia B

2006-04-01

181

Xanthan gum biosynthesis and application: a biochemical/genetic perspective.  

PubMed

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 food and non-food industries. Xanthan gum is also used as a stabilizer for a wide variety of suspensions, emulsions, and foams. This article outlines aspects of the biochemical assembly and genetic loci involved in its biosynthesis, including the synthesis of the sugar nucleotide substrates, the building and decoration of the pentasaccharide subunit, and the polymerization and secretion of the polymer. An overview of the applications and industrial production of xanthan is also covered. PMID:9763683

Becker, A; Katzen, F; Pühler, A; Ielpi, L

1998-08-01

182

Strategy to identify and quantify polysaccharide gums in gelled food concentrates.  

PubMed

A strategy for the unambiguous identification and selective quantification of xanthan gum and locust bean gum (LBG) in gelled food concentrates is presented. DNA detection by polymerase chain reaction (PCR) showed to be a fast, sensitive, and selective method that can be used as a first screening tool in intact gelled food concentrates. An efficient isolation procedure is described removing components that may interfere with subsequent analyses. NMR spectroscopy enabled the direct identification of xanthan gum and the discrimination between different galactomannans in the isolated polysaccharide fraction. An enzymatic fingerprinting method using endo-?-mannanase, in addition to being used to differentiate between galactomannans, was developed into a selective, quantitative method for LBG, whereas monosaccharide analysis was used to quantify xanthan gum. Recoveries for xanthan gum and LBG were 87% and 70%, respectively, with in-between day relative standard deviations below 20% for xanthan gum and below 10% for LBG. PMID:25053026

Grün, Christian H; Sanders, Peter; van der Burg, Monique; Schuurbiers, Eric; van Adrichem, Linda; van Velzen, Ewoud J J; de Roo, Niels; Brunt, Kommer; Westphal, Yvonne; Schols, Henk A

2015-01-01

183

Polyelectrolyte complexes of gum kondagogu and chitosan, as diclofenac carriers  

Microsoft Academic Search

Polyelectrolyte complexes (PEC) of gum kondagogu (GKG) and chitosan were prepared by mixing polymeric solutions of different concentrations (0.02–0.18% w\\/v). The complex formed were loaded with diclofenac sodium, and the release of the drug was measured invitro and in vivo, along with the measurement of particle size, zeta potential, complex formation, flow properties, and loading efficiency. Maximum yield of PEC

V. G. M. Naidu; K. Madhusudhana; R. B. Sashidhar; S. Ramakrishna; Roop K. Khar; Farhan J. Ahmed; Prakash V. Diwan

2009-01-01

184

Effect of Hydrophilic Gums on Frozen Dough. I. Dough Quality  

Microsoft Academic Search

Cereal Chem. 80(6):764-772 Disadvantages of frozen doughs are their variable performance and loss of stability over long-term frozen storage. Changes in rheological properties of frozen doughs have been reported to be due to the physical damage of the gluten network caused by ice crystallization and recrystallization. The objective of this study was to determine the effect of hydrophilic gums on

R. Sharadanant; K. Khan

2003-01-01

185

Antispasmodic and hypotensive effects of Ferula asafoetida gum extract  

Microsoft Academic Search

The effects of Ferula asafoetida gum extract on the contractile responses of the isolated guinea-pig ileum induced by acetylcholine, histamine and KCl, and on the mean arterial blood pressure of rat were investigated. In the presence of extract (3mg\\/ml), the average amplitude of spontaneous contractions of the isolated guinea-pig ileum was decreased to 54±7% of control. Exposure of the precontracted

Mohammad Fatehi; Freshteh Farifteh; Zahra Fatehi-Hassanabad

2004-01-01

186

Modification of Starch by Dry Heating with Ionic Gums  

Microsoft Academic Search

Cereal Chem. 79(5):601-606 Waxy maize (native and hydroxypropylated (HP)) and potato starches were impregnated with ionic gums (sodium alginate, CMC, and xanthan, 1% based on starch solids) and heat-treated in a dry state for 0, 2, or 4 hr at 130°C. Effects of the dry heating on paste viscosity (RVA) and clarity (light transmittance) were examined. Heat treatment with sodium

S.-T. Lim; J.-A. Han; H. S. Lim; J. N. BeMiller

2002-01-01

187

Structural investigation of the polysaccharide of Spondias mombin gum  

Microsoft Academic Search

The polysaccharide, isolated from Spondias mombin gum exudate, was subjected to acid hydrolysis and Smith degradation processes in order to investigate its relevant structural features. Chemical and spectral evidence suggested the existence of small blocks of (1?3)-linked ?-d-galactosyl residues, interspersed with 6-O substituted d-galactosyl residues, in the backbone of the investigated structure; these residues are also in the side-chains. In

G León de Pinto; M Mart??nez; O Beltrán; F Rincón; J Manuel Igartuburu; F Rodriguez Luis

2000-01-01

188

Oxygen transfer and uptake rates during xanthan gum production.  

PubMed

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 as a function of biomass concentration, including overall growth and non growth-associated oxygen uptake. A metabolic kinetic model has been employed for xanthan gum production description including oxygen mass transfer and uptake rates. The results point out that this model is able to describe adequately not only oxygen dissolved evolution, but also of the production of xanthan and substrate consumption. Also, the influence of several parameters (k(L)a, air flow rate and dissolved oxygen) in the evolution of the key compounds of the system have been studied. The results of the simulation shown that an increasing of dissolved oxygen concentration favor the xanthan gum production. PMID:11064050

García-Ochoa; Castro; Santos

2000-11-15

189

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

190

Insulin chewing gum: Need of the day for diabetic patients.  

PubMed

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

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

2011-07-01

191

Xanthan gum stabilized gold nanoparticles: Characterization, biocompatibility, stability and cytotoxicity.  

PubMed

Xanthan gum (XG) has been widely used in food, pharmaceutical and cosmetic industries. In the present study, we explored the potential of XG in the synthesis of gold nanoparticle. XG was used as both reducing and stabilizing agent. The effect of various formulation and process variables such as temperature, reaction time, gum concentration, gum volume and gold concentration, in GNP preparation was determined. The XG stabilized, rubey-red XGNP were obtained with 5ml of XG aqueous solution (1.5mg/ml). The optimum temperature was 80°C whereas the reaction time was 3h. The optimized nanoparticles were also investigated as drug delivery carrier for doxorubicin hydrochloride. DOX loaded gold nanoparticles (DXGP) were characterized by dynamic light scattering, TEM, FTIR, and DSC analysis. The synthesized nanoparticle showed mean particle size of 15-20nm and zeta potential -29.1mV. The colloidal stability of DXGP was studied under different conditions of pH, electrolytes and serum. Nanoparticles were found to be stable at pH range between pH 5-9 and NaCl concentration up to 0.5M. In serum, nanoparticles showed significant stability up to 24h. During toxicity studies, nanoparticles were found biocompatible and non-toxic. Compared with free DOX, DXGP displayed 3 times more cytotoxicity in A549 cells. In conclusion, this study provided an insight to synthesize GNP without using harsh chemicals. PMID:24906721

Pooja, Deep; Panyaram, Sravani; Kulhari, Hitesh; Rachamalla, Shyam S; Sistla, Ramakrishna

2014-09-22

192

Synthesis and characterization of monodisperse copper nanoparticles using gum acacia  

NASA Astrophysics Data System (ADS)

A simple method was put forward in this paper for preparing colloidal copper nanoparticles in aqueous solutions using copper sulfate, gum acacia and hydrazine hydrate as copper precursor, capping agents and reducing agents, respectively, without any inert gas. The formation of nanosized copper was confirmed by its characteristic surface plasmon absorption peak at 604 nm in UV-vis spectra. The transmission electron microscopic (TEM) and scanning electron microscope (SEM) images show that the as-synthesized copper fine spherical particles are distributed uniformly with a narrow distribution from 3 nm to 9 nm. The X-ray diffraction (XRD) and high resolution transmission electron microscopic (HRTEM) demonstrated that the obtained metallic nanoparticles are single crystalline copper nanoparticles. Fourier transform infra-red (FT-IR) spectroscopic data suggested that the copper nanoparticles are coated with gum acacia. The effects of the quantity of gum acacia on the particle size were investigated by the UV-vis spectra and TEM images. The growth process of the nanoparticles was monitored by the UV-vis spectra. The mechanism of the formation copper nanoparticles was discussed. The process raised in this study can be served as an excellent candidate for the preparation of copper nanoparticles in a large scale production.

Dong, Chunfa; Cai, Hao; Zhang, Xianglin; Cao, Chuanliang

2014-03-01

193

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 9–22% 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

194

Production of xanthan gum by Sphingomonas bacteria carrying genes from Xanthomonas campestris  

Microsoft Academic Search

  Twelve genes coding for assembly, acetylation, pyruvylation, polymerization, and secretion of the polysaccharide xanthan\\u000a gum are clustered together on the chromosome of the bacterium Xanthomonas campestris. These genes (gumBCDEFGHIJKLM) are sufficient for synthesis of xanthan gum when placed in bacteria from a different genus, Sphingomonas. The polysaccharide from the recombinant microorganism is largely indistinguishable, structurally and functionally, from\\u000a native xanthan

T J Pollock; M Mikolajczak; M Yamazaki; L Thorne; R W Armentrout

1997-01-01

195

Nutritional and Digestive Challenges to Being a Gum-Feeding Primate  

Microsoft Academic Search

\\u000a Gum is an unusual food that presents significant challenges to animals that feed on it. Gum is limited in availability; trees\\u000a generally secrete it only in response to damage. Gum is a ?-linked complex polysaccharide, and as such is resistant to mammalian\\u000a digestive enzymes and requires fermentation by gut microbes. It contains little or no lipid, low amounts of protein,

Michael L. Power

196

Structural features of an arabinogalactan gum exudates from Spondias dulsis (Anacardiaceae)  

Microsoft Academic Search

The tree Spondias dulcis, located in Venezuela, exudes a light-brown gum. The polysaccharide, isolated from the original gum, contains galactose, arabinose, mannose, rhamnose, glucuronic acid, and its 4-O-methyl derivative. Application of chemical methods, in combination with 1D and 2D NMR spectroscopy afforded interesting structural features of the gum polysaccharide. The unequivocal presence of rhamnose in the polymer structure was confirmed

Maritza Mart??nez; Gladys León de Pinto; Lilian Sanabria; Olga Beltrán; José M. Igartuburu; Ali Bahsas

2003-01-01

197

[Use of autogenous fibroblasts of human oral mucosa for gum recession treatment].  

PubMed

Minimally invasive soft tissue augmentation is a challenging problem for dentists. Use of autogenous fibroblast of oral mucosa is a promising method. The paper represents the results of preclinical, clinical and laboratory studies on the use of autogenous oral mucosa fibroblasts (AOMF) for gum recession correction. The results confirm statistically significant gum thickness augmentation and gum recession decrease after three weekly AOMF injections. The effect lasted for at least 9 months. PMID:23528396

Grudianov, A I; Stepanova, I I; Zorin, V L; Zorina, A I; Kopnin, P B; Cherkasov, V R

2013-01-01

198

Locust bean gum: processing, properties and food applications--a review.  

PubMed

Locust bean gum or carob gum is a galactomannan obtained from seed endosperm of carob tree i.e. Ceratonia siliqua. It is widely utilized as an additive in various industries such as food, pharmaceuticals, paper, textile, oil well drilling and cosmetics. Industrial applications of locust bean gum are due to its ability to form hydrogen bonding with water molecule. It is also beneficial in the control of many health problems like diabetes, bowel movements, heart disease and colon cancer due to its dietary fiber action. This article focuses on production, processing, composition, properties, food applications and health benefits of locust bean gum. PMID:24548746

Barak, Sheweta; Mudgil, Deepak

2014-05-01

199

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

PubMed

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

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

2013-05-15

200

Characterization, Thermal, and Mechanical Behaviours of Gamma Irradiated Gum Arabic\\/Poly Vinyl Alcohol Polymer Blends  

Microsoft Academic Search

Polymer blends based on various compositions of natural macromolecule gum arabic (GA) and poly vinyl alcohol (PVA) were prepared by solution casting technique. It was found that the maximum concentration of gum from which a compatible blend can be obtained was found to be from 10–30%. Compatible blend were exposed to gamma irradiation at different doses of 20, 30, and

Mervat S. Ibrahim; Sayeda M. Ibrahim; Serag A. Farag

2007-01-01

201

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

PubMed

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

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

2014-08-01

202

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

203

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

204

The Inhibition of aluminium corrosion in hydrochloric acid solution by exudate gum from Raphia hookeri  

Microsoft Academic Search

The corrosion inhibition of aluminium in HCl solution in the presence of exudate gum from Raphia hookeri at temperature range of 30–60°C was studied using weight loss and thermometric techniques. The exudate gum acts as an inhibitor in the acid environment. The inhibition efficiency increases with increase in inhibitor concentration but decreases with an increase in temperature. The inhibitive effect

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

2009-01-01

205

Rheological behaviour of whey protein stabilized emulsions in the presence of gum arabic  

Microsoft Academic Search

The rheological behaviour of whey protein isolate-stabilized emulsions was investigated in the presence of gum arabic (0–15 wt%). The flow behaviour of the emulsion was observed to be pseudoplastic at all gum concentrations. The increase in ionic strength reduced the magnitude of the apparent viscosity indicating that electrostatic interactions between the high molecular weight polysaccharide molecules influenced the rheology of

Esra ?bano?lu

2002-01-01

206

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

Microsoft Academic Search

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

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

2004-01-01

207

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

ERIC Educational Resources Information Center

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

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

2008-01-01

208

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

209

Ethanol-resistant ethylcellulose/guar gum coatings--importance of formulation parameters.  

PubMed

Recently, ethylcellulose/guar gum blends have been reported to provide ethanol-resistant drug release kinetics from coated dosage forms. This is because the ethanol insoluble guar gum effectively avoids undesired ethylcellulose dissolution in ethanol-rich bulk fluids. However, so far the importance of crucial formulation parameters, including the minimum amount of guar gum to be incorporated and the minimum required guar gum viscosity, remains unclear. The aim of this study was to identify the most important film coating properties, determining whether or not the resulting drug release kinetics is ethanol-resistant. Theophylline matrix cores were coated in a fluid bed with blends of the aqueous ethylcellulose dispersion "Aquacoat®ECD30" and guar gum. The polymer blend ratio, guar gum viscosity, and degree of dilution of the final coating dispersion were varied. Importantly, it was found that more than 5% guar gum (referred to the total polymer content) must be incorporated in the film coating and that the apparent viscosity of a 1% aqueous guar gum solution must be greater than 150 cP to provide ethanol-resistance. In contrast, the investigated degree of coating dispersion dilution was not found to be decisive for the ethanol sensitivity. Furthermore, all investigated formulations were long term stable, even upon open storage under stress conditions for 6 months. PMID:23891769

Rosiaux, Y; Velghe, C; Muschert, S; Chokshi, R; Leclercq, B; Siepmann, F; Siepmann, J

2013-11-01

210

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...by reason of imports from Austria and/or China of xanthan gum, provided for in subheading 3913.90.20 of the...

2012-06-12

211

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

ERIC Educational Resources Information Center

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

Gottlieb, Andrew M.; And Others

1987-01-01

212

Zeta potentials of gum arabic stabilised oil in water emulsions  

Microsoft Academic Search

The electrostatic contribution to the mechanism by which gum arabic stabilises oil in water has been investigated using laser Doppler electrophoresis. Electrophoretic mobilities of d-limonene emulsion droplets measured in 10?3, 10?2 and 10?1M NaCl over a pH range from 1 to 10, and 10?3–10?1M CaCl2 in doubly distilled water, yielded relatively low potentials (less than 28mV in magnitude). The interpreted

M. L Jayme; D. E Dunstan; M. L Gee

1999-01-01

213

Entrapment of Flaxseed Oil Within Gelatin-Gum Arabic Capsules  

Microsoft Academic Search

The aim of this study was to optimize the encapsulation of flaxseed oil within a gelatin-gum Arabic (GA) matrix via complex\\u000a coacervation. The effect of homogenization rates (3,000–15,000 rpm) and total biopolymer concentrations (1–2% w\\/v) on emulsion\\u000a efficiency was studied in order to optimize the wall matrix. The physicochemical properties of the dried powder, and the capsule’s\\u000a ability to inhibit oxidation

S. Liu; N. H. Low; Michael T. Nickerson

2010-01-01

214

Complex coacervation between ?-lactoglobulin and acacia gum in aqueous medium  

Microsoft Academic Search

The compatibility of ?-lactoglobulin (?-lg) and acacia gum in aqueous medium was investigated as a function of the pH (3.6–5.0), the protein to polysaccharide weight ratio (50:1–1:20) and the total biopolymer concentration (0.1–5wt%). The ternary phase diagrams obtained at low ionic strengths (0.005–10.7mM) typically accounted for phase separation through complex coacervation. Thus a drop-shaped two-phase region was anchored in the

C. Schmitt; C. Sanchez; F. Thomas; J. Hardy

1999-01-01

215

A diallel cross analysis of gum content in barley (Hordeum vulgare).  

PubMed

A diallel cross analysis of gum content in barley (Hordeum vulgare) was made using six cultivars of two-rowed spring barley as parents. A Jinks-Hayman analysis of F2 progeny means showed that gum content was controlled by a simple additive-dominance genetic system and that low gum content was strongly dominant. The analysis suggested that gum content was principally controlled by two or three genes showing a high degree of dominance. Some genotype-environment interaction was detected in a comparison between the F2 and F3 generations which were grown in different years and locations. However, the character was found to be highly heritable both within and between generations, suggesting that the selection and breeding of barleys of reduced gum content should not be difficult. PMID:24407497

Greenberg, D C

1977-01-01

216

Evaluation of guar gum in the preparation of sustained-release matrix tablets.  

PubMed

Polymeric hydrophilic matrices are widely used for controlled-release preparations. The process of drug release is controlled by matrix swelling or polymer dissolution. It has been shown that the swelling of guar gum is affected by concentration of drug and viscosity grade of the polymer. This study examines the mechanism of behavior of guar gum in a polymer-drug matrix. The swelling action of guar gum, in turn, is controlled by the rate of water uptake into the matrices. An inverse relationship exists between the drug concentration in the gel and matrix swelling. This implies that guar gum swelling is one of the factors affecting drug release. The swelling behavior of guar gum is therefore useful in predicting drug release. PMID:9876566

Khullar, P; Khar, R K; Agarwal, S P

1998-11-01

217

Identification of Anogeissus latifolia Wallich and analysis of refined gum ghatti.  

PubMed

Natural medicinal exudates such as gum arabic are high-molecular-weight natural polysaccharides and are highly soluble in water. The dissolved solutions of these exudates show viscous behavior and exhibit favorable emulsion stability. These exudates have been widely used not only as a medicinal additive, such as a coating agent for tablets and as an emulsifier and stabilizer in beverage and food products, but also for other industrial applications, such as paints and ink. Gum ghatti was originally used as an alternative to gum arabic due to its similar properties to those found in gum arabic. Gum ghatti has been used as a food additive due to its excellent emulsification properties. In this study, we obtained gum ghatti nodules and branches as botanical specimens, which were collected from the same harvesting area. Refined gum ghatti processed from the collected gum ghatti nodules was found to comply with the specifications set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and also to be identical to commercially available gum ghatti products as a food additive. Component analysis of the refined gum ghatti samples revealed that they contain arabinose (34.0-38.0 %), galactose (21.0-24.6 %), mannose (5.3-7.9 %), xylose (0.8-1.2 %), rhamnose (0.8-1.2 %), and glucuronic acid (15.4-18.6 %) as constituent sugars, protein (2.7-3.6 %), moisture (4.9-8.3 %), and tannin (0.041-0.092 %). As a result of the investigation of collected branches as botanical specimens, they were identified as Anogeissus latifolia Wallich. Detailed observation of their morphological characteristics revealed that many crystal cells were aligned in the lengthwise section of branch specimens. PMID:22730002

Sakai, Eiji; Katayama, Tsuyoshi; Ogasawara, Takeshi; Mizuno, Mizuo

2013-04-01

218

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

PubMed

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

Enauyatifard, Reza; Azadbakht, Mohammad; Fadakar, Yousef

2012-01-01

219

Comparison of MR Enteroclysis with Colonoscopy in Crohn's Disease-First Locust Bean Gum Study from Turkey  

PubMed Central

Background/Aim: The aim of this study was to compare magnetic resonance enteroclysis (MRE) findings with those of colonoscopy, using locust bean gum (LBG) as an oral contrast agent in the diagnosis and follow-up of patients with Crohn's disease. Materials and Methods: Nine patients with histologically proven Crohn's disease were enrolled in this study; MRE was performed within a week of colonoscopy. All patients were examined using a 1.5 T MR Scanner after per os administration of 850 mL of a combination of LBG and mannitol. After intravenous administration of 50 mg Eritromisin and 40 mg Scopolamine, images were obtained using a T2-weighted, balanced GRE, fat-suppressed T1-weighted sequence, before and after intravenous gadolinium administration. Bowel wall thickness and enhancement of inflamatory bowel wall were measured. Results: The oral ingestion of LBG was well tolerated and allowed optimal small and large bowel distention in all patients. MR findings correlated with the colonoscopy results. Additional inflammatory lesions of the colon and mesenteric inflamatory changes such as lymphadenopathy, conglomerate tumor, and fistulas were demonstrated. Contrast enhancement of the affected bowel wall was markedly increased and positive correlation was obtained between bowel wall enhancement and bowel wall thickness. Conclusion: Gadolinium-enhanced MRE with oral locust bean gum is very efficient in the detection and follow-up of the intestinal and extraintestinal findings of Crohn's disease.

Narin, Burcu; Sungurlu, Faik; Balci, Aysun; Arman, Alper; Kurdas, Oya O.; Simsek, Masum

2009-01-01

220

Effect of xanthan gum and guar gum on in situ gelling ophthalmic drug delivery system based on poloxamer-407.  

PubMed

The aim of this investigation was to develop a novel in situ gelling formulation based on poloxamer-407 (PM) for the sustained release of an ophthalmic drug. In an attempt to reduce the concentration of PM without compromising the in situ gelling capability and also to increase the drug release time, xanthan gum (XG) and guar gum (GG) were added into PM to develop different formulations. At concentrations of 18% and above, the PM was able to undergo sol-gel transition below body temperature. It was found that XG and GG at a weight ratio of 3:7 were able to convert PM solution into gel below body temperature at PM concentrations below 18%. Both the in vitro and in vivo studies indicated that the PM with an XG-GG combination had a better ability to retain the drug than PM itself. The results indicated that the developed in situ gelling formulations containing PM with XG-GG may be a better alternative than a conventional eye drop. PMID:23988556

Bhowmik, Manas; Kumari, Puja; Sarkar, Gunjan; Bain, Mrinal Kanti; Bhowmick, Biplab; Mollick, Md Masud Rahaman; Mondal, Dibyendu; Maity, Dipanwita; Rana, Dipak; Bhattacharjee, Debashis; Chattopadhyay, Dipankar

2013-11-01

221

Study of antimicrobial activity and atomic force microscopy imaging of the action mechanism of cashew tree gum.  

PubMed

The aim of this work was to evaluate the antimicrobial potential of two grades of cashew tree gum (crude and purified) against eight microorganisms and to analyze the mechanism of cashew tree gum antimicrobial action via atomic force microscopy (AFM) imaging. The results indicated strong antimicrobial properties of pure cashew tree gum against all tested microorganisms, except for Candida albicans and Lactobacillus acidophilus. On the other hand crude cashew gum showed antimicrobial activity only against Gram-positive bacteria (MRSA, MSSA, Listeria innocua and Enterococcus faecium). Atomic force microscopy imaging showed that pure cashew tree gum lead to bacterial cell collapse. In conclusion cashew tree gum presented relevant antimicrobial activity against most of the studied bacteria, and the purification of the cashew gum affected its antimicrobial spectrum. PMID:24751040

Campos, Débora A; Ribeiro, Alexandra C; Costa, Eduardo M; Fernandes, João C; Tavaria, Freni K; Araruna, Felipe Bastos; Eiras, Carla; Eaton, Peter; Leite, José Roberto S A; Manuela Pintado, M

2012-09-01

222

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

SciTech Connect

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

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

2013-01-15

223

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

PubMed Central

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

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

2014-01-01

224

Effects of chewing gum on short-term appetite regulation in moderately restrained eaters.  

PubMed

Orosensory stimulation is an important contributing factor to the development of satiation. Providing orosensory stimulation with few calories may satisfy appetite and help to suppress cravings for high energy snacks. This may be a useful strategy for those motivated to lose or maintain weight. The present study tested the hypothesis that chewing sweetened gum will reduce subjective appetite and subsequent snack intake in moderately restrained eaters. Within-subjects, repeated measures study, sixty healthy participants (53 women; body mass index, in kg/m(2): 26.2±4.5) came to the laboratory 4 times for a standard lunch. Immediately after this meal, participants rated hunger, appetite and cravings for sweet and salty snacks every hour until they returned to the laboratory 3 h later for snack. On two occasions during this 3 h period participants chewed gum for at least 15 min at hourly intervals (45 min) and on two occasions no gum was chewed. On two occasions salty snacks were offered and on two occasions sweet snacks were provided. A small but significant reduction in snack intake was observed, chewing gum reduced weight of snack consumed by 10% compared to no gum (p<0.05). Overall, chewing gum for at least 45 min significantly suppressed rated hunger, appetite and cravings for snacks and promoted fullness (p<0.05). This study demonstrated some benefit of chewing gum which could be of utility to those seeking an aid to appetite control. PMID:21718732

Hetherington, Marion M; Regan, Martin F

2011-10-01

225

Guar gum coupled microscale ZVI for in situ treatment of CAHs: continuous-flow column study.  

PubMed

A column study was performed under in situ conditions to evaluate to which extend the inactivation of the microscale zerovalent iron (mZVI) by guar gum occurs under continuous flow conditions. Five aquifer containing columns were set up under different conditions. Efficient removal of trichloroethene was observed for the column amended by mZVI. Stabilization of the mZVI with guar gum led to slightly reduced activity. More reduced reactivity was observed in the poisoned column containing guar gum stabilized mZVI. This confirms that soil microorganisms can degrade guar gum and that subsequent removal of the oligosaccharides by the groundwater flow (flushing effect) can reactivate the mZVI. After more than six months of continuous operation the columns were dismantled. DNA-based qPCR analysis revealed that mZVI does not significantly affect the bacterial community, while guar gum stabilized mZVI particles can even induce bacterial growth. Overall, this study suggests that the temporarily decreased mZVI reactivity due to guar gum, has a rather limited impact on the performance of in situ reactive zones. The presence of guar gum slightly reduced the reactivity of iron, but also slowed down the iron corrosion rate which prolongs the life time of reactive zone. PMID:24333711

Velimirovic, Milica; Simons, Queenie; Bastiaens, Leen

2014-01-30

226

Smoking Cessation during Alcohol Treatment: A Randomized Trial of Combination Nicotine Patch plus Nicotine Gum  

PubMed Central

Aims The primary aim was to compare the efficacy of smoking cessation treatment using the combination of active nicotine patch plus active nicotine gum versus therapy consisting of active nicotine patch plus placebo gum in a sample of alcohol dependent tobacco smokers in an early phase of outpatient alcohol treatment. A secondary aim was to determine whether or not there were any carryover effects of combination nicotine replacement on drinking outcomes. Design Small scale randomized double-blind placebo controlled clinical trial with one-year smoking and drinking outcome assessment. Setting Two outpatient substance abuse clinics provided a treatment platform of behavioral alcohol and smoking treatment delivered in three months of weekly sessions followed by three monthly booster sessions. Participants Participants were 96 men and women with a diagnosis of alcohol abuse or dependence and smoking 15 or more cigarettes per day. Intervention All participants received open-label transdermal nicotine patch and were randomized to receive either 2 mg nicotine gum or placebo gum under double blind conditions. Findings Analysis of 1-year follow-up data revealed that patients receiving nicotine patch plus active gum had better smoking outcomes than those receiving patch plus placebo gum on measures of time to smoking relapse and prolonged abstinence at 12 months. Alcohol outcomes were not significantly different across medication conditions. Conclusions Results of this study were consistent with results of larger trials of smokers without alcohol problems showing that combination therapy (nicotine patch plus gum) is more effective than monotherapy (nicotine patch) for smoking cessation.

Cooney, Ned L.; Cooney, Judith L.; Perry, Bridget L.; Carbone, Michael; Cohen, Emily H.; Steinberg, Howard R.; Pilkey, David T.; Sevarino, Kevin; Oncken, Cheryl A.; Litt, Mark D.

2009-01-01

227

Freeze-dried Xanthan/Guar Gum Nasal Inserts for the Delivery of Metoclopramide Hydrochloride  

PubMed Central

Prolonged residence of drug formulation in the nasal cavity is important for the enhancing intranasal drug delivery. The objective of the present study was to develop a mucoadhesive in-situ gelling nasal insert which would enable the reduced nasal mucociliary clearance in order to improve the bioavailability of metoclopramide hydrochloride. Metoclopramide hydrochloride is a potent antiemetic and effective for preventing emesis induced by cancer chemotherapy, migraine, pregnancy and gastroparesis. It undergoes hepatic first pass metabolism and both the absolute bioavailability and the plasma concentrations are subjected to wide inter-individual variation showing values between 32% and 98%. Oral antiemetic often gets vomited out before the systemic absorption compelling parenteral administration which results in low patient compliance. Adverse effect of metoclopramide HCL on CNS caused by high plasma peaks can be avoided through sustained formulation. A novel combination of xanthan gum and guar gum was used to prepare the nasal inserts and the effect of blend ratio of xanthan gum and guar gum on drug release from in-situ gelling nasal inserts and on other insert properties such as bioadhesion potential and water uptake was studied. PXRD was used to determine the effect of freeze-drying on crystalline nature of formulation. The viscosities of xanthan gum in combination with guar gum were observed to be higher than that of single polymer solutions. This is because of the synergistic rheological interaction between xanthan and guar gum. There is a substantial loss in crystalline nature of the formulation after freeze-drying. The best nasal inserts formulation containing xanthan gum and guar gum ratio 1:5, showed good release (91.83%) as well as bioadhesion which may result in an increase in the nasal residence time.

Dehghan, Mohamed Hassan; Girase, Mohan

2012-01-01

228

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

PubMed

Xanthan gum, a microbial desiccation-resistant polysaccharide prepared commercially by aerobic submerged fermentation from Xanthomonas campestris, has been successfully used as a solidifying agent for plant tissue culture media. Its suitability as a substitute to agar 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 cultures of Calliandra tweedii. Culture media used for eliciting these morphogenic responses were gelled with either 1% xanthan gum or 0.9% agar. Xanthan gum, like agar, supported all these responses. PMID:16331459

Jain, R; Babbar, S B

2006-03-01

229

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

2012-10-01

230

Characteristics of xanthan gum-based biodegradable superporous hydrogel.  

PubMed

A novel biopolymer-based superporous hydrogel (SPH) was synthesized through chemical crosslinking by graft copolymerization of 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AA) on to xanthan gum (XG) via redox initiator system of ammonium persulfate (APS) and N, N, N', N'-tetramethylethylenediamine (TMED), in the presence of N, N'-methylenebisacrylamide (MBA) crosslinking agent, sodium bicarbonate foaming agent, a triblock copolymer of polyoxyethylene/polyoxypropylene/polyoxyethylene as a foam stabilizer. Characterization of SPH was done by FT-IR, TGA, SEM, HPC and GCMS. The effects of pH and salinity on the swelling aptitude of the SPH were investigated along with its degradability in Streptococcus bovis medium. PMID:19643130

Gils, Palapparambil Sunny; Ray, Debajyoti; Sahoo, Prafulla Kumar

2009-11-01

231

Flocculation characteristics and biodegradation studies of Gum ghatti based hydrogels.  

PubMed

Biodegradable flocculants of Gum ghatti (Gg) with acrylamide (AAm) were prepared through graft co-polymerization technique using potassium persulphate (KPS)-ascorbic acid (ABC) redox pair as initiator and N,N'-methylene-bis-acrylamide (MBA) as a crosslinker. Gg-cl-poly(AAm) was found to exhibit pH and temperature responsive swelling behavior. Maximum flocculation efficiency of Gg-cl-poly(AAm) was observed with 15 mg L(-1) polymer dose in acidic medium at 50°C. Biodegradation studies of Gg and Gg-cl-poly(AAm) were done using composting method. Gg was found to degrade within 20 days, whereas, Gg-cl-poly(AAm) was found to degrade 88.18% within 60 days. Different stages of bio-degradation were characterized through FT-IR and SEM techniques. PMID:23541560

Mittal, H; Mishra, Shivani B; Mishra, A K; Kaith, B S; Jindal, R

2013-07-01

232

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

233

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

PubMed

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

Hearty, Aine; Lau, Annette; Roberts, Ashley

2014-07-01

234

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

ERIC Educational Resources Information Center

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

Witter, A. E.

2005-01-01

235

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

236

Antibacterial activities of some constituents from oleo-gum-resin of Commiphora mukul.  

PubMed

The essential oil, chloroform extract and seven sesquiterpenoids compounds newly isolated from the oleo-gum-resin of Commiphora mukul showed a wide range of inhibiting activity against both Gram (+) and Gram (-) bacteria. PMID:15030926

Saeed, M Asif; Sabir, A W

2004-03-01

237

Preventing Cavities, Gum Disease, Tooth Loss, and Oral Cancers at a Glance 2011  

MedlinePLUS

Preventing Cavities, Gum Disease, Tooth Loss, and Oral Cancers At A Glance 2011 On this Page At A Glance ... facial expressions. However, oral diseases, which range from cavities to oral cancer, cause pain and disability for ...

238

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

PubMed Central

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

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

2012-01-01

239

Antibacterial activities of some constituents from oleo-gum-resin of Commiphora mukul  

Microsoft Academic Search

The essential oil, chloroform extract and seven sesquiterpenoids compounds newly isolated from the oleo-gum-resin of Commiphora mukul showed a wide range of inhibiting activity against both Gram (+) and Gram (?) bacteria.

M. Asif Saeed; A. W. Sabir

2004-01-01

240

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

241

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

242

In vitro evaluation of Moringa oleifera gum for colon-specific drug delivery  

PubMed Central

Background: Moringa gum obtained from stem of the plant Moringa oleifera Lam. belonging to family Moringaceae. Number of naturally occurring polysaccharides obtained from plant (guar gum, inulin), animal (chitosan, chondrotin sulphate), algal (alginates) or microbial (dextran) origin. Objective: The present study was evaluated Moringa oleifera gum as a carrier for colon specific drug delivery using in vitro drug release studies. Materials and Methods: Six formulations of curcumin were prepared using varying concentration of Moringa oleifera gum containing 50 mg curcumin by wet granulation method. Tablets were subjected for evaluation by studying the parameter like hardness, friability, drug content uniformity and in vitro drug release study. Hardness was found to be in the range of 5.5 to 7.3 kg/cm2, the percentage friability was in the range of 0.60 to 0.89%, and tablet showed 98.99% to 99.89% of the labeled amount of curcumin indicating uniformity in drug content. Results and Discussion: In vitro drug release study was performed using simulated stomach, intestinal and colonic fluid. The susceptibility of Moringa gum to colonic bacteria was also assessed using drug release study with rat caecal contents. 30% Moringa gum containing formulation (F-3) was shown better drug released that is 90.46%, at the end of 24 h of dissolution study in the presence of rat caecal contents in comparison to 40% Moringa gum containing formulation (F-4) that was 78.03%. Conclusion: The results illustrate the usefulness of Moringa olefera gum as a potential carrier for colon-specific drug delivery.

Singhal, Anil Kumar; Jarald, Edwin E; Showkat, Ahmad; Daud, Anwar

2012-01-01

243

Reduced aggregation and sedimentation of zero-valent iron nanoparticles in the presence of guar gum.  

PubMed

Injection of nanoscale zero-valent iron (NZVI) is potentially a promising technology for remediation of contaminated groundwaters. However, the efficiency of this process is significantly hindered by the rapid aggregation of the iron nanoparticles. The aim of this study was to enhance the colloidal stability of the nanoparticles through the addition of the "green" polymer guar gum. We evaluated the properties of guar gum and its influence on the surface properties, particle size, aggregation, and sedimentation of iron nanoparticles. Commercial iron nanoparticles were dispersed in guar gum solutions, and their aggregation and sedimentation behaviors were compared to those of bare iron nanoparticles and commercial nanoparticles modified with a biodegradable polymer (polyaspartate). High performance size exclusion chromatography, charge titration, and viscosity assessment showed that guar gum is a high molecular weight polymer which is nearly neutrally charged, rendering it suitable for steric stabilization of the iron nanoparticles. Electrophoretic mobility measurements demonstrated the ability of guar gum to adsorb on the nanoparticles, forming a slightly negatively charged layer. Dynamic light scattering experiments were conducted to estimate the particle size of the different nanoparticle suspensions and to determine the aggregation behavior at different ionic strengths. Guar gum effectively reduced the hydrodynamic radius of the bare nanoparticles from 500 nm to less than 200 nm and prevented aggregation of the nanoparticles even at very high salt concentrations (0.5 M NaCl and 3 mM CaCl(2)). Sedimentation profiles of the different nanoparticle suspensions confirmed the improved stability of the iron nanoparticles in the presence of guar gum. The results strongly suggest that guar gum can be used to effectively deliver stabilized zero-valent iron nanoparticles for remediation of contaminated groundwater aquifers. PMID:18508073

Tiraferri, Alberto; Chen, Kai Loon; Sethi, Rajandrea; Elimelech, Menachem

2008-08-01

244

Solubility Enhancement of Lovastatin by Modified Locust Bean Gum Using Solid Dispersion Techniques  

Microsoft Academic Search

The aim of the present study was to improve the solubility of poorly water soluble drug lovastatin (LS) by solid dispersion\\u000a (SD) techniques using modified locust bean gum (MLBG) as a carrier. The locust bean gum (LBG) was modified by heating and\\u000a there observed irreversible decrease in viscosity, whereas swelling property remains unaffected. The advantage of modification\\u000a of LBG was

Manjil Patel; Avinash Tekade; Surendra Gattani; Sanjay Surana

2008-01-01

245

Strong Band-Edge Emission from ZnS Quantum Dots Stabilized by Gum Arabic  

NASA Astrophysics Data System (ADS)

ZnS quantum dots (QDs), prepared by soft-condensation, exhibit robust structure of a quantum size equal 3.13 nm mediated two-dimensional gum Arabic surfactant as characterized by scan tunnelling microscope (STM). Strong blue-shifted absorption and emission bands are depicted by optical characterization even for the sample stored under ambient condition for two weeks. These enhancements can be attributed to the completely passivated surface trap states by Gum Arabic.

Hatim, Dirar Mohamed El-Khair

2008-12-01

246

Gum arabic glycoprotein contains glycomodules of both extensin and arabinogalactan-glycoproteins  

Microsoft Academic Search

Gum arabic glycoprotein (GAGP) is a large molecular weight, hydroxyproline-rich arabinogalactan-protein (AGP) component of gum arabic. GAGP has a simple, highly biased amino acid composition indicating a repetitive polypeptide backbone. Previous work (Qi, W., Fong, C., Lamport, D.T.A., 1991. Plant Physiology 96, 848), suggested small (?11 residue) repetitive peptide motifs each with three Hyp-arabinoside attachment sites and a single Hyp-arabinogalactan

Leslie J. Goodrum; Amar Patel; Joseph F. Leykam; Marcia J. Kieliszewski

2000-01-01

247

Effect of xanthan and locust bean gums on the gelling properties of myofibrillar protein  

Microsoft Academic Search

Protein-hydrocolloids interactions play an important role on textural and mechanical properties of foods. The objective of this work was to evaluate the effect of xanthan and locust bean gums on the gelling ability of myofibrillar proteins at different levels of calcium addition. Surimi was supplemented with xanthan (X) and locust bean (LB) gums at different X\\/LB ratios: 0.00\\/1.00, 0.25\\/0.75, 0.50\\/0.50,

J. A. Ram??rez; M. Barrera; O. G. Morales; M. Vázquez

2002-01-01

248

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

249

Swelling Behavior of Guar Gum-g-Poly(Sodium Acrylate -co-Styrene)\\/Attapulgite Superabsorbent Composites  

Microsoft Academic Search

A series of superabsorbent composites, guar gum-g-poly(sodium acrylate-co- styrene)\\/attapulgite (GG-g-P(NaA-co-St)\\/APT), were prepared by simultaneous grafting partially neutralized acrylic acid (NaA) and hydrophobic styrene (St) onto guar gum (GG) in the presence of attapulgite (APT) as an inorganic component. Equilibrium swelling capacity strongly depended on the concentration of St, drastically increasing with increasing St concentration to 24.3 mmol\\/L and then decreasing.

XIAONING SHI; WENBO WANG; AIQIN WANG

2011-01-01

250

Structure and Function of Polysaccharide Gum-Based Edible Films and Coatings  

Microsoft Academic Search

\\u000a Polysaccharide gums are hydrocolloids of considerable molecular weight, and are water-soluble. They dissolve in and form intensive\\u000a hydrogen bonds with water. Because of the size and configuration of their molecules, these polysaccharides have the ability\\u000a to thicken and\\/or gel aqueous solutions as a result of both hydrogen bonding between polymer chains and intermolecular friction\\u000a when subjected to shear. Gums dissolve

Marceliano B. Nieto

251

Anti-stress effects of chewing gum prepared with yeast hydrolysate  

Microsoft Academic Search

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

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

2008-01-01

252

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

PubMed

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

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

2001-07-01

253

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

NASA Technical Reports Server (NTRS)

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

Simoes Nunes, C.; Malmlof, K.

1992-01-01

254

Pharmacological properties of guggulsterones, the major active components of gum guggul.  

PubMed

Oleo gum resin secreted by Commiphora mukul, also known as gum guggul, has been used widely as an ayurvedic drug. Commiphora mukul is a short thorny shrub that is native to the Indian subcontinent. Oleo gum resin extracted by incision of the bark is a very complex mixture of gum, minerals, essential oils, terpenes, sterols, ferrulates, flavanones and sterones. Its active constituents, the Z- and E-guggulsterones, have been demonstrated to exhibit their biological activities by binding to nuclear receptors and modulating the expression of proteins involved in carcinogenic activities. Guggulsterones have also been reported to regulate gene expression by exhibiting control over other molecular targets including transcription factors such as nuclear factor (NF)-?B, signal transducer and activator of transcription (STAT) and steroid receptors. Considerable scientific evidence indicates the use of gum guggul as a therapeutic agent in the treatment of inflammation, nervous disorders, hyperlipidaemia and associated cardiac disorders such as hypertension and ischaemia, skin disorders, cancer and urinary disorders. This review highlights the taxonomic details, phytochemical properties and pharmacological profile of gum guggul. PMID:22388973

Shah, Rohan; Gulati, Vandana; Palombo, Enzo A

2012-11-01

255

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

PubMed

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

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

2013-04-01

256

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

PubMed Central

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

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

2013-01-01

257

Pasting properties of Tamarind (Tamarindus indica) kernel powder in the presence of Xanthan, Carboxymethylcellulose and Locust bean gum in comparison to Rice and Potato flour.  

PubMed

Effects of addition of different levels of gums (xanthan, carboxymethylcellulose and locust bean gum) on the pasting properties of tamarind kernel, potato and rice flour were studied by using Rapid Visco-Analyzer (RVA). Tamarind kernel powder (TKP) varied significantly (P?gum mixtures were dependent upon the concentration and type of the gums. Peak, breakdown and final viscosity increased with increase in gum concentration in the flour/gum mixture, but the effect was more pronounced for rice and potato flour than for TKP which showed much lower viscosity responses to all of the gums. Among the three gums studied, the increase in viscosity was significantly higher with addition of locust bean gum followed by xanthan while the lowest was observed with carboxymethylcellulose. PMID:24425986

Kaur, Maninder; Sandhu, Kawaljit Singh; Kaur, Jasmeen

2013-08-01

258

Development of an optimal formulation for oxidative stability of walnut-beverage emulsions based on gum arabic and xanthan gum using response surface methodology  

Microsoft Academic Search

The susceptibility of lipids to oxidation is one of the most fundamental problems in oil-in-water emulsions. A response surface methodology 5-level-3-factor central-composite rotatable design was applied to study the effects of key formula ingredients including walnut oil (WO, 3–6%, w\\/w), gum arabic (GA, 5–10%, w\\/w) and xanthan gum (XG, 0.05–0.15%, w\\/w) on lipid oxidation in walnut-beverage emulsions. During 30 days’

Seyed Mohammad Taghi Gharibzahedi; Seyed Mohammad Mousavi; Manouchehr Hamedi; Faramarz Khodaiyan; Seyed Hadi Razavi

259

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

PubMed

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

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

2013-01-01

260

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

PubMed

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

Soparkar, P; Newman, M B

2001-07-01

261

TheOptimumTimetoInitiate Habitual Xylitol Gum-chewing forObtaining Long-term Caries Prevention  

Microsoft Academic Search

Habitual xylitol gum-chewing mayhavealong- termpreventive effect byreducing thecaries risk forseveral years after thehabitual chewing hasended. Thegoalofthis report was(1)todetermine ifsorbitol andsorbitol\\/xylitol mixtures provide along-term benefit, and(2)todetermine whichteeth benefit mostfromtwo-year habitual gum-chew- ing-those erupting before, during, orafter habitual gum- chewing. Children, onaverage 6years old, chewedgums sweetened withxylitol, sorbitol, orxylitol\\/sorbitol mixtures. Therewasa\\

P. P. Hujoell; K. K. M'akinen; C. A. Bennett; K. P. Isotupa; P. J. Isokangas; P. Allen; L. Makinen

262

Magnetism  

NSDL National Science Digital Library

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

2010-10-27

263

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

264

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

265

Evaluation of Gum of Moringa oleifera as a Binder and Release Retardant in Tablet Formulation  

PubMed Central

The present study was undertaken to find out the potential of gum from Moringa oleifera to act as a binder and release retardant in tablet formulations. The effect of calcium sulphate dihydrate (water insoluble) and lactose (water soluble) diluent on the release of propranolol hydrochloride was studied. The DSC thermograms of drug, gum and mixture of gum/drug indicated no chemical interaction. Tablets (F1, F2, F3, and F4) were prepared containing calcium sulphate dihydrate as diluent, propranolol hydrochloride as model drug using 10%, 8%, 6% and 4% w/v of gum solution as binder. Magnesium stearate was used as lubricant. Physical and technological properties of granules and tablets like flow rate, Carr index, Hausner ratio, angle of repose, hardness, friability and disintegration time were determined and found to be satisfactory. Tablets were prepared by wet granulation method containing calcium sulphate dihydrate as excipient, propranolol hydrochloride as model drug using 10%, 20% and 30% of gum as release retardant, magnesium stearate was used as lubricant. Similarly tablets were prepared replacing lactose with calcium sulphate dihydrate. Despite of the widely varying physico-chemical characteristics of the excipients, the drug release profiles were found to be similar. The drug release increased with increasing proportions of the excipient and decreased proportion of the gum irrespective of the solubility characteristics of the excipient. The values of release exponent ‘n’ are between 0.37 and 0.54. This implies that the release mechanism is Fickian. There is no evidence that the dissolution or erosion of the excipient has got any effect on the release of the drug. The t50% values for tablets containing calcium sulphate dihydrate were on an average 10%-15% longer than the tablets containing lactose as excipient. These relatively small differences in t50% values suggest that the nature of excipient used appeared to play a minor role in regulating the release, while the gum content was a major factor.

Panda, D. S.; Choudhury, N. S. K.; Yedukondalu, M.; Si, S.; Gupta, R.

2008-01-01

266

Physical Properties of Gum Karaya-Starch-Essential Oil Patches  

PubMed Central

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.

Shcherbina, Yulia; Roth, Zvi

2010-01-01

267

Effect of molecular configuration of Xanthan gum drage reduction  

NASA Astrophysics Data System (ADS)

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

Rochefort, Skip; Middleman, Stanley

1986-01-01

268

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

PubMed

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

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

2001-07-01

269

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

2013-07-01

270

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

PubMed Central

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

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

2008-01-01

271

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

PubMed

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

Gastone, Francesca; Tosco, Tiziana; Sethi, Rajandrea

2014-05-01

272

Electrically conducting silver/guar gum/poly(acrylic acid) nanocomposite.  

PubMed

This article describes the synthesis of an electrically conducting silver/guar gum/poly(acrylic acid) nanocomposite hydrogel. The synthesis process started with grafting acrylic acid monomers onto the natural polymer guar gum by the use of ammonium persulphate as a free radical initiator in acid medium. Guar gum/poly(acrylic acid) graft copolymer was separated from the polymerization medium, purified and subjected to crosslinking treatment, using alkaline epichlorohydrin as a crosslinking agent. Silver nitrate solution was added during the crosslinking treatment in varying concentrations, that the reaction conditions affect crosslinking of guar gum/poly(acrylic acid) graft copolymer to a hydrogel, as well as reduction of silver nitrate to silver nanoparticles, giving rise to the formation of silver/guar gum/poly(acrylic acid) nanocomposite. Factors affecting the grafting reaction as well as those affecting the crosslinking/reduction treatment were optimized. The so synthesized nanocomposite hydrogel samples were fully characterized, regarding their contents of silver nanoparticles and swelling ratio. The electrical conductivity of the nanocomposite hydrogel was studied and it was found to be affected by the swelling ratio of the hydrogel as well as its content of silver nanoparticles. PMID:24928058

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

2014-08-01

273

First-principles Calculations of Ideal Tensile and Shear Strengths for Gum-Metal Approximants  

NASA Astrophysics Data System (ADS)

A newly developed bcc-type Ti-23Nb-0.7Ta-2Zr-O (mol%) alloy named Gum-Metal showed unusual properties including ultralow elastic modulus, ultrahigh strength, super-elastic-like behavior, and super-plastic-like behavior, in particular, accompanied by dislocation-free plastic deformation. [1]. As proposed in first-principles calculations, one of the requirements for the Gum-Metal is dramatic softening of the elastic shear modulus C'=(C11-C12)/2 ˜ 0, which happens at a valence electron concentration around 4.24. We also study ideal tensile and shear strengths for Gum-Metal approximants to understand microscopic origin of such unique mechanical properties. The most stable Gum-metal approximant among all the possible 1820 atomic configurations of Ti12Nb4 has been determined, and showed good agreement with the experimental elastic constants of Gum-Metal.[4pt] [1] T. Saito et al., Science 300, 464 (2003).

Nagasako, Naoyuki; Jahnatek, Michal; Asahi, Ryoji; Hafner, Jürgen

2010-03-01

274

Nicotine Gum and Self-Help Behavioral Treatment for Smoking Relapse Prevention: Results from a Trial Using Population-Based Recruitment.  

ERIC Educational Resources Information Center

Smokers were randomized using a factorial design to compare nicotine gum use to no gum use, and self-help materials to no materials. Compared with the no-gum group, relapse occurred at a significantly lower rate in the gum group for the entire 12 months of follow-up. There was no significant main effect for the self-help materials and no…

Fortmann, Stephen P.; Killen, Joel D.

1995-01-01

275

Thermodynamic characterization of acacia gum-beta-lactoglobulin complex coacervation.  

PubMed

The interactions of beta-lactoglobulin (BLG) with total acacia gum (TAG) in aqueous solutions have been investigated at pH 4.2 and 25 degrees C. Isothermal titration calorimetry (ITC) has been used to determine the type and magnitude of the energies involved in the complexation process of TAG to BLG. Dynamic light scattering (DLS), electrophoretic mobility (mu(E)), turbidity measurements (tau), and optical microscopy were used as complementary methods on the titration mode to better understand the sum of complicated phenomena at the origin of thermodynamic behavior. Two different binding steps were detected. Thermodynamic parameters indicate a first exothermic step with an association constant K(a1) of (48.4 +/- 3.6) x 10(7) M(-1) that appeared to be mostly enthalpy-driven. A positive heat capacity change was obtained corresponding at the signature for electrostatic interactions. The second binding step, 45 times less affinity (K(a2) = (1.1 +/- 0.1) x 10(7) M(-1)), was largely endothermic and more entropy-driven with a negative value of heat capacity change, indicative of a hydrophobic contribution to the binding process. The population distribution of the different species in solution and their sizes were determined through DLS. Dispersion turbidity of particles markedly increased and reached a maximum at a 0.015 TAG/BLG molar ratio. Largely more numerous coacervates appeared at this molar ratio (0.015) and two different kinds of morphologies were noticed for the large coacervates. Above the TAG/BLG molar ratio of 0.015, dispersions turbidity decreased, which might be due to an excess of negative charges onto particles as revealed by electrophoretic mobility measurements. The results presented in this study should provide information about the thermodynamic mechanisms of TAG/BLG binding processes and will facilitate the application of the formed supramolecular assemblies as functional ingredients in food and nonfood systems. PMID:20586462

Aberkane, Leïla; Jasniewski, Jordane; Gaiani, Claire; Scher, Joël; Sanchez, Christian

2010-08-01

276

Productivity improvement in xanthan gum fermentation using multiple substrate optimization.  

PubMed

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

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

2003-01-01

277

The effect of chewing gum on physiological and self-rated measures of alertness and daytime sleepiness.  

PubMed

The proposition that chewing gum can improve alertness was investigated via both physiological and self-rated measures. The Pupillographic Sleepiness Test (PST) provided a measure of pupillary unrest (PUI); a physiological index of daytime sleepiness. Chewing gum reduced the extent of sleepiness as measured by both PUI and self-rated sleepiness. Specifically, in comparison with sham chewing and no chewing controls, the chewing gum condition significantly limited the increase in pupillary unrest following the 11-minute PST within a darkened laboratory: a finding indicating moderation of the daytime sleepiness increase for the chewing gum condition. In addition, there was some evidence that chewing gum (relative to the no-chewing condition only) moderated the increase in a self-rated measure of sleepiness (Stanford Sleepiness Scale). However, there was no evidence that chewing gum moderated the decrease in self-rated alertness (Bond-Lader Visual Analogue Mood Scale). Although the precise mechanism underpinning the effect of chewing gum is unclear, the reduction in daytime sleepiness may be underpinned via heightened cerebral activity following the chewing of gum or the arousing effects of mint flavour. PMID:22061430

Johnson, Andrew J; Miles, Christopher; Haddrell, Ben; Harrison, Emily; Osborne, Liam; Wilson, Nigel; Jenks, Rebecca

2012-02-01

278

The effect of chewing gum on physiological and self-rated measures of alertness and daytime sleepiness  

Microsoft Academic Search

The proposition that chewing gum can improve alertness was investigated via both physiological and self-rated measures. The Pupillographic Sleepiness Test (PST) provided a measure of pupillary unrest (PUI); a physiological index of daytime sleepiness. Chewing gum reduced the extent of sleepiness as measured by both PUI and self-rated sleepiness. Specifically, in comparison with sham chewing and no chewing controls, the

Andrew J. Johnson; Christopher Miles; Ben Haddrell; Emily Harrison; Liam Osborne; Nigel Wilson; Rebecca Jenks

279

A water-insoluble drug monolithic osmotic tablet system utilizing gum arabic as an osmotic, suspending and expanding agent  

Microsoft Academic Search

A monolithic osmotic tablet system (MOTS) with two orifices in both side surfaces has been studied. Water-insoluble naproxen was selected as the model drug. Gum arabic was used as an osmotic, suspending and expanding agent, and cellulose acetate (CA) was used as semipermeable membrane. Polyethylene glycol 400(PEG-400) was employed as plasticizer for controlling membrane porosity. The influences of gum arabic,

En-Xian Lu; Zhi-Qiang Jiang; Qi-Zhi Zhang; Xin-Guo Jiang

2003-01-01

280

Formulation of Extruded Snack Food (Gum Based Cereal–Pulse Blend): Optimization of Ingredients Levels Using Response Surface Methodology  

Microsoft Academic Search

Response surface methodology (RSM) was used to analyse the effect of corn flour, green gram flour, xanthan, guar gum, arabic gum and carboxymethyl cellulose (CMC) on the sensory and objective (expansion ratio) attributes of an extruded snack food. A rotatable central-composite design was used to develop models for the sensory and objective responses. The experiments were run at 160°C with

Sushma Thakur; D. C Saxena

2000-01-01

281

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

PubMed Central

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

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

2012-01-01

282

Influence of Pectin and Guar Gum Composite Flour on Plasma Biochemical Profile of Streptozotocin-Induced Diabetic Male Albino Rats  

Microsoft Academic Search

Dietary fiber sources like pectin and guar gum have gained immense importance because of their constructive role of releasing sugars and absorbing sugars slowly in the intestinal tract; consequently, they reduce the severity of diabetes mellitus. In this article, we explore the hypoglycemic and hypocholesterolemic worths of pectin and guar gum by adding them to wheat flour to prepare chapaties,

M. S. Butt; Aftab Ahmad; M. K. Sharif

2007-01-01

283

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

284

Ipomoea dasysperma seed gum: an effective natural coagulant for the decolorization of textile dye solutions.  

PubMed

An investigation of dye decolorization from synthetic dye solutions using the non-ionic, water-soluble, high molecular weight seed gums Ipomoea dasysperma and guar gum as coagulants was undertaken. The use of galactomannans derived from plants in this system presents a sustainable method of textile effluent treatment. These natural coagulants extracted from plants proved to be workable alternatives to conventional coagulants like polyaluminum chloride, as they are biodegradable, safe to human health, are cost effective when compared to imported chemicals and have a wider effective dosage range for flocculation of various colloidal suspensions. Coagulant dose and coagulation pH are important factors influencing the mechanism of coagulation. Also the type and chemical structure of the dye plays an important role in the coagulation process. The seed gums alone were found to be effective for decolorization of direct dye and in combination with PAC their coagulation efficiency was well extended even for reactive and acid dyes. PMID:16549236

Sanghi, Rashmi; Bhattacharya, Bani; Dixit, Awantika; Singh, Vandana

2006-10-01

285

Chromatographic resolution of racemic ?-amino acids: chiral stationary phase derived from modified xanthan gum.  

PubMed

Enantiomeric resolution of ?-amino acids into L-amino acid and D-amino acid via column chromatography using chiral stationary phase was performed. For this purpose, a dynamic chiral stationary phase prepared by grafting of methylmethacrylate onto xanthan gum (XG) was successfully employed in resolving various ?-amino acids racemates. The peculiarities of the chromatographic behaviour of xanthan gum-graft-poly(methylmethacrylate)-amino acid interaction and the mechanism of their retention in column are discussed. The enantioselective properties of the xanthan gum-graft-poly(methylmethacrylate) in the separation of enantiomers of ?-amino acids were studied using acidic solution of alanine, leucine, valine and tryptophan. The procedure is characterized by simplicity, efficiency and relatively low cost to analyze enantiomers of some amino acids. PMID:23399277

Pandey, Sadanand; Mishra, Shivani B

2013-02-15

286

Fastidian gum: the Xylella fastidiosa exopolysaccharide possibly involved in bacterial pathogenicity.  

PubMed

The Gram-negative bacterium Xylella fastidiosa was the first plant pathogen to be completely sequenced. This species causes several economically important plant diseases, including citrus variegated chlorosis (CVC). Analysis of the genomic sequence of X. fastidiosa revealed a 12 kb DNA fragment containing an operon closely related to the gum operon of Xanthomonas campestris. The presence of all genes involved in the synthesis of sugar precursors, existence of exopolysaccharide (EPS) production regulators in the genome, and the absence of three of the X. campestris gum genes suggested that X. fastidiosa is able to synthesize an EPS different from that of xanthan gum. This novel EPS probably consists of polymerized tetrasaccharide repeating units assembled by the sequential addition of glucose-1-phosphate, glucose, mannose and glucuronic acid on a polyprenol phosphate carrier. PMID:11583843

da Silva, F R; Vettore, A L; Kemper, E L; Leite, A; Arruda, P

2001-09-25

287

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 Café Ferreira, Rita

2013-11-01

288

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

PubMed

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

Israelsson, A; Gustafsson, H; Lund, E

2013-04-01

289

Double edged effect of gum-resin of ferula assa-foetida on lifespan of neurons  

PubMed Central

Objective(s): Based on knowledge from traditional herbal medicine, Ferula assa-foetida (asafoetida) has several therapeutic applications but there is less knowledge about its effect on neurons. Materials and Methods: In order to evaluate neuronal differentiation, neuronal like cells were stained against neuronal specific markers ?-Tubulin III and MAP2. After establishment of neuronal differentiation in cultured cells, aqueous extract of gum-resin of asafoetida were applied on culture medium of neurons with different concentrations then survival rate of neurons were evaluated by cell counting and methyl tetrazolium bromide (MTT) tests. Results: The results showed that asafoetida gum resin particularly with 0.01 and 1 µg/ml concentrations could improve survival rate of neurons, while10 µgr/ml treated group was toxic. Conclusion: Results of this study indicated that gum resin of asafoetida in low doses has neuroprotective effect on neurons and improves survival rate of them, however in higher concentrations it is toxic for neurons.

Homayouni Moghadam, Farshad; Vakili Zarch, Behzad; Shafiei, Mohammad

2013-01-01

290

Determining the collection efficiency of gummed paper for the deposition of radioactive contaminants in simulated rain.  

PubMed

An extensive network of gummed paper collectors was used during the 1950s for routine monitoring of radioactive fallout from weapons testing. The experiments reported in this paper were designed to examine the collection efficiency of gummed paper for wet deposition of several types of soluble and insoluble radioactive contaminants under conditions similar to those found during natural rainstorms. The collection efficiencies for each substance were determined over a range of rainfall amounts and at two separate rainfall intensities. The collection efficiency of the gummed paper is highest for large insoluble particles and lowest for soluble ionic substances. The values for 7Be and 131I ranged from about 0.30 (30%) at 2.5 mm of rain to 0.04-0.06 (4%-6%) at 20 mm of rain. These values were negatively correlated with the amount of rain and were unaffected by rain intensity. This suggests that the collection efficiency of either ion is simply a matter of rapid saturation and runoff. Neither rain amount nor rain intensity has much effect on the collection efficiency of large insoluble particles. These particles seem to settle readily onto the surface of the gummed paper from which they are not easily removed by additional rain. Analysis of the collection efficiencies of the gummed paper included the activity of both the gummed paper and the standing water on the paper. A large portion of the activity for the ionic substances was found in the standing water. There was less activity by insoluble particles in standing water. This indicates that for estimates of deposition of soluble substances, considerable bias could be introduced into the results if the standing water is discarded prior to analysis. PMID:1559814

Hoffman, F O; Thiessen, K M; Frank, M L; Blaylock, B G

1992-05-01

291

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

PubMed Central

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

2012-01-01

292

Development and Antibacterial Activity of Cashew Gum-Based Silver Nanoparticles  

PubMed Central

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

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

293

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

NASA Astrophysics Data System (ADS)

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

Withey, Elizabeth Ann

294

Theory of the nonplanar splitting of screw dislocations in Gum Metal  

NASA Astrophysics Data System (ADS)

A theoretical model is suggested that describes nonplanar splitting of perfect dislocations into partials in a newly discovered group of alloys called Gum Metal. Within the model, the partials have line cores located at a nanoscale circle and are connected by (generalized) stacking faults. Due to the complicated nonplanar structure of the split dislocation configuration and associated stacking faults, the split dislocation has a low mobility. Results of the model take into account experimental data on suppression of dislocation slip in Gum Metal reported in the literature.

Bobylev, S. V.; Ishizaki, T.; Kuramoto, S.; Ovid'Ko, I. A.

2008-03-01

295

Partially hydrolyzed guar gum in pediatric functional abdominal pain  

PubMed Central

AIM: To assess the effects of partially hydrolyzed guar gum (PHGG) diet supplement in pediatric chronic abdominal pain (CAP) and irritable bowel syndrome (IBS). METHODS: A randomized, double-blind pilot study was performed in sixty children (8-16 years) with functional bowel disorders, such as CAP or IBS, diagnosed according to Rome III criteria. All patients underwent ultrasound, blood and stool examinations to rule out any organic disease. Patients were allocated to receive PHGG at dosage of 5 g/d (n = 30) or placebo (fruit-juice n = 30) for 4 wk. The evaluation of the efficacy of fiber supplement included IBS symptom severity score (Birmingham IBS Questionnaire), severity of abdominal pain (Wong-Baker Face Pain Rating Score) and bowel habit (Bristol Stool Scale). Symptom scores were completed at 2, 4, and 8 wk. The change from baseline in the symptom severity scale at the end of treatment and at 4 wk follow-up after treatment was the primary endpoint. The secondary endpoint was to evaluate compliance to supplementation with the PHGG in the pediatric population. Differences within groups during the treatment period and follow-up were evaluated by the Wilcoxon signed-rank test. RESULTS: The results of the study were assessed considering some variables, such as frequency and intensity of symptoms with modifications of the bowel habit. Both groups were balanced for baseline characteristics and all patients completed the study. Group A (PHGG group) presented a higher level of efficacy compared to group B (control group), (43% vs 5%, P = 0.025) in reducing clinical symptoms with modification of Birmingham IBS score (median 0 ± 1 vs 4 ± 1, P = 0.025), in intensity of CAP assessed with the Wong-Baker Face Pain Rating Score and in normalization of bowel habit evaluated with the Bristol Stool Scale (40% vs 13.3%, P = 0.025). In IBS subgroups, statistical analysis shown a tendency toward normalization of bowel movements, but there was no difference in the prevalence of improvement in two bowel habit subsets. PHGG was therefore better tolerated without any adverse effects. CONCLUSION: Although the cause of pediatric functional gastrointestinal disorders is not known, the results show that complementary therapy with PHGG may have beneficial effects on symptom control.

Romano, Claudio; Comito, Donatella; Famiani, Annalisa; Calamara, Sabrina; Loddo, Italia

2013-01-01

296

The effect of sugar-free and sugar chewing gums on plaque deposition  

PubMed Central

Background: Chewing gum is a habit practiced regularly by a relatively high proportion of individuals in many countries including India, and its use has increased within the last decade. The aim of this study was to determine the effects of sugar-free and sugar chewing gums on plaque deposition. Materials and Methods: The study is a double blind clinical trial involving 16 healthy volunteers (divided into 2 groups) in a 4-day plaque regrowth model. On day one, subjects received professional prophylaxis, suspended oral hygiene measures, and commenced chewing their allocated product. Gum chewing was one piece chewed for 30 minutes 3 times a day. On day 5, subjects were scored for plaque with the help of Silness and Loe Index. Results: Results show sugar-free group have a lesser mean plaque score of 0.98 as compare to sugar group (1.23), though this difference was not statistically significant. Conclusion: The sugar-free gums can be used as an adjunct to mechanical oral hygiene measures.

Tangade, Pradeep; Mathur, Anmol; Chaudhary, Shikha; Gupta, Rahul

2012-01-01

297

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

298

On the stabilization mechanism of Doogh (Iranian yoghurt drink) by gum tragacanth  

Microsoft Academic Search

Serum separation in Doogh, a favorite acidic dairy drink in the Middle East, is a major problem which happens due to low pH (?4.00) and aggregation of caseins. Therefore, in the present study the influence of gum tragacanth (GT) and its soluble and insoluble fractions on prevention of serum separation as well as stabilization mechanisms were investigated using rheological, zeta

Fatemeh Azarikia; Soleiman Abbasi

2010-01-01

299

Reduced aggregation and sedimentation of zero-valent iron nanoparticles in the presence of guar gum  

Microsoft Academic Search

Injection of nanoscale zero-valent iron (NZVI) is potentially a promising technology for remediation of contaminated groundwaters. However, the efficiency of this process is significantly hindered by the rapid aggregation of the iron nanoparticles. The aim of this study was to enhance the colloidal stability of the nanoparticles through the addition of the “green” polymer guar gum. We evaluated the properties

Alberto Tiraferri; Kai Loon Chen; Rajandrea Sethi; Menachem Elimelech

2008-01-01

300

A Biomechanical Analysis of Skull Form in Gum-Harvesting Galagids  

Microsoft Academic Search

Among primates, some highly gummivorous species habitually gouge trees to elicit exudate flow whereas others scrape the hardened gums from trees. These foraging behaviors are thought to require high external forces at the anterior dentition. In this study, we test whether skull form in gouging and scraping galagids corresponds to this suggested need to produce these higher external forces and

Susan H. Williams; Christine E. Wall; Christopher J. Vinyard; William L. Hylander

2002-01-01

301

A Biomechanical Analysis of Skull Form in Gum‐Harvesting Galagids  

Microsoft Academic Search

Among primates, some highly gummivorous species habitually gouge trees to elicit exudate flow whereas others scrape the hardened gums from trees. These foraging behaviors are thought to require high external forces at the anterior dentition. In this study, we test whether skull form in gouging and scraping galagids corresponds to this suggested need to produce these higher external forces and

Susan H. Williams; Christine E. Wall; Christopher J. Vinyard; William L. Hylander

2002-01-01

302

Xanthan gum production from cassava bagasse hydrolysate with Xanthomonas campestris using alternative sources of nitrogen.  

PubMed

Cassava bagasse was hydrolyzed using HCl and the hydrolysate was used for the production of xanthan gum using a bacterial culture of Xanthomonas campestris. Cassava bagasse hydrolysate with an initial concentration of approx 20 g of glucose/L proved to be the best substrate concentration for xanthan gum production. Among the organic and inorganic nitrogen sources tested to supplement the medium-urea, yeast extract, peptone, potassium nitrate, and ammonium sulfate-potassium nitrate was most suitable. Ammonium sulfate was the least effective for xanthan gum production, and it affected sugar utilization by the bacterial culture. In media with an initial sugar concentration of 48.6 and 40.4 g/L, at the end of fermentation about 30 g/L of sugars was unused. Maximum xanthan gum (about 14 g/L) was produced when fermentation was carried out with a medium containing 19.8 g/L of initial reducing sugars supplemented with potassium nitrate and fermented for 72 h, and it remained almost the same until the end of fermentation (i.e., 96 h). PMID:15304758

Woiciechowski, Adenise L; Soccol, Carlos R; Rocha, Saul N; Pandey, Ashok

2004-01-01

303

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

304

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

Microsoft Academic Search

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

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

2006-01-01

305

Study of Mutagenic Effects of Gum Arabic (FDA No. 71-15).  

National Technical Information Service (NTIS)

The study includes results of three mutagenic assay procedures. The host-mediated assay of gum arabic (71-15) did not produce any measurable mutagenic response or alteration in the recombination frequency for Saccharomyces cerevisiae in either the host-me...

G. W. Newell W. A. Maxwell

1972-01-01

306

Carboxymethyl gum kondagogu-chitosan polyelectrolyte complex nanoparticles: preparation and characterization.  

PubMed

The interaction between carboxymethyl gum kondagogu and chitosan was optimized to prepare polyelectrolyte complex nanoparticles using ofloxacin as the model drug. The effect of concentrations of carboxymethyl gum kondagogu and chitosan on the particle size and % drug entrapment was screened using 2-factor, 3-level central composite experimental design. The results revealed that the concentration of carboxymethyl gum kondagogu has a pronounced effect on the particle size while the concentration of chitosan affected the drug entrapment prominently. The optimized concentrations of carboxymethyl gum kondagogu and chitosan were 0.031% (w/v) and 0.059% (w/v) respectively. The optimized batch of nanoparticles had a particle size of 285.9 nm, entrapment efficiency of 63% and was observed to be ovoid in shape. Screening of ofloxacin-loaded nanoparticles for antibacterial activity with aqueous ofloxacin solution revealed no significant difference between the two formulations. Nanoparticles provided a sustained release with 50% of the drug getting released in 24 h following Higuchi's square-root kinetics. PMID:23994791

Kumar, Ashok; Ahuja, Munish

2013-11-01

307

Release of peppermint flavour compounds from chewing gum: effect of oral functions  

Microsoft Academic Search

During chewing, the oral cavity functions like a bellow, forcing volatile flavour compounds into the exhaling air to the nasal compartment. Accordingly, we hypothesised that flavour release from chewing gum is predominantly governed by chewing frequency (CF), although other oral functions, like masseter muscle activity (MMA), chewing force (CFO), and saliva flow rate (SFR), may also play a role. In

Anne-Mette Haahr; Allan Bardow; Carsten E. Thomsen; Siri B. Jensen; Birgitte Nauntofte; Merete Bakke; Jens Adler-Nissen; Wender L. P. Bredie

2004-01-01

308

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

309

Graft polymerization of guar gum with acryl amide irradiated by microwaves for colonic drug delivery.  

PubMed

This article is aimed to discuss the modification of guar gum through microwave irradiation by varying the time of irradiation. The characterization of the modified products was carried out using FTIR spectroscopic analysis. The FT-IR spectrum of the pure guar gum (GG) sample showed a broad peak at 3298 cm(-1) while the modified GG sample displayed a peak at 1541 cm(-1) which was absent in the crude sample. The X-ray diffraction (XRD) analysis confirmed the increase in crystallinity due to grafting of the sample with polyacrylamide (GG-g-PAM). Scanning electron microscope (SEM) images revealed that granular form of guar gum was changed into fibrillar structure after grafting. Thermo-gravimetric analysis of the modified samples was also carried out and discussed. The role of guar gum as a matrix for controlled release of drug triamcinolone was evaluated. The GG-acrylamide grafted samples presented a correlation between drug release and time of microwave exposure. The results revealed that such modified product has potential applications in colonic drug delivery system. PMID:23973495

Shahid, Muhammad; Bukhari, Shazia Anwer; Gul, Yousra; Munir, Hira; Anjum, Fozia; Zuber, Mohammad; Jamil, Tahir; Zia, Khalid Mahmood

2013-11-01

310

The effect of electrostatic interactions on pasting properties of potato starch\\/xanthan gum combinations  

Microsoft Academic Search

The effects of electrostatic interactions on pasting properties of potato starch (PS)\\/xanthan gum (XG) combinations were investigated. The RVA peak viscosity of combinations was decreased firstly and then increased with the adding of XG. The analysis and regression model performance of RVA measurement showed that there was the relationship between pasting properties of combinations and XG concentrations. Electrostatic repulsions between

Xuran Cai; Yan Hong; Zhengbiao Gu; Yayuan Zhang

2011-01-01

311

Gum rosin–acetone system as an analogue to the degassing behaviour of hydrated magmas  

Microsoft Academic Search

Solutions of gum rosin and acetone reproduce the volatile- and temperature-dependent viscosity, together with the phase behaviour, of hydrated magmas. A range of experimental exsolution conditions was investigated, including the variation of supersaturation, rate of decompression, solution temperature and volatile content. Degassing processes were controlled by the formation of an exsolution interface above a supersaturated liquid. The end-products ranged from

J. C. Phillips; A.-M. Lejeune; M. Hilton

1995-01-01

312

Evaluation of the Health Aspects of Carob Bean Gum as a Food Ingredient.  

National Technical Information Service (NTIS)

The available information reveals that there are no short-term toxicological consequences in chicks, rats, mice, hamsters, rabbits, and man of consuming carob bean gum in amounts exceeding those currently consumed in the normal diet of the U.S. population...

1972-01-01

313

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, 19-63 years), a test-retest assessment (Experiment 2: n = 10; four men, 20-49 years) and compared to an established wax cubes mixing ability test (Experiment 3: n = 13; 0 men, 21-31 years). 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 = 57·270, P = 0·000) and reliable in the test-retest (ICC value of 0·714, P = 0·004). 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

2013-10-01

314

Safety and Effectiveness of Nicotine Chewing Gum for Smoking Cessation in USAF Aviators.  

National Technical Information Service (NTIS)

A double blind randomized placebo controlled trial of 2 mg nicotine chewing gum is proposed to test its safety and effectiveness for smoking cessation in USAF flying personnel. Subjects are USAF flyers who desire to quit smoking. The study has two parts: ...

W. P. Thorton

1985-01-01

315

Xanthan Gum from Austria and China. Investigation Nos. 731-TA-1202-03(Preliminary).  

National Technical Information Service (NTIS)

On June 5, 2012, a petition was filed with the Commission and Commerce by CP Kelco U.S., Atlanta, GA, alleging that an industry in the United States is materially injured or threatened with material injury by reason of LTFV imports of xanthan gum from Aus...

2012-01-01

316

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

317

Effect of organic matter on estuarine flocculation: a laboratory study using montmorillonite, humic acid, xanthan gum, guar gum and natural estuarine flocs  

PubMed Central

Background Riverine particles undergo a rapid transformation when they reach estuaries. The rapid succession of hydrodynamic and biogeochemical regimes forces the particles to flocculate, settle and enter the sediment pool. The rates and magnitudes of flocculation depend on the nature of the particles which are primarily affected by the types and quantities of organic matter (OM). Meanwhile, the OM characteristics vary widely between environments, as well as within a single environment due to seasonal climate and land use variability. We investigated the effect of the OM types and quantities through laboratory experiments using natural estuarine particles from the Mississippi Sound and Atchafalaya Bay as well as model mixtures of montmorillonite and organic molecules (i.e., biopolymers (guar/xanthan gums) and humic acid). Results Biopolymers promote flocculation but the magnitude depends on the types and quantities. Nonionic guar gum yields much larger flocs than anionic xanthan gum, while both of them exhibit a nonlinear behavior in which the flocculation is the most pronounced at the intermediate OM loading. Moreover, the effect of guar gum is independent of salinity whereas the effect of xanthan gum is pronounced at higher salinity. Meanwhile, humic acid does not affect flocculation at all salinity values tested in this study. These results are echoed in the laboratory manipulation of the natural estuarine particles. Flocculation of the humic acid-rich Mississippi Sound particles is unaffected by the OM, whereas that of biopolymer-rich Atchafalaya Bay particles is enhanced by the OM. Conclusions Flocculation is positively influenced by the presence of biopolymers that are produced as the result of marine primary production. Meanwhile, humic acid, which is abundant in the rivers that drain the agricultural soils of Southeastern United States, has little influence on flocculation. Thus, it is expected that humic acid-poor riverine particles (e.g., Mississippi River, and Atchafalaya River, to a lesser degree) may be prone to rapid flocculation and settling in the immediate vicinity of the river mouths when mixed with biopolymer-rich coastal waters. It is also expected that humic acid-rich riverine particles (e.g., Pearl River) may resist immediate flocculation and be transported further away from the river mouth.

2014-01-01

318

The Use of Hibiscus esculentus (Okra) Gum in Sustaining the Release of Propranolol Hydrochloride in a Solid Oral Dosage Form  

PubMed Central

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

Noordin, Mohamed Ibrahim; Kadivar, Ali

2014-01-01

319

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

PubMed

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

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

2014-01-01

320

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

PubMed Central

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

Kumar, M. Uday; Babu, M. Kishore

2014-01-01

321

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

322

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

PubMed

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

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

2013-02-13

323

Bone bonding ability of a chemically and thermally treated low elastic modulus Ti alloy: gum metal.  

PubMed

The gum metal with composition Ti-36Nb-2Ta-3Zr-0.3O, is free from cytotoxic elements and exhibits a low elastic modulus as well as high mechanical strength. We have previously demonstrated that this gum metal, once subjected to a series of surface treatments--immersion in 1 M NaOH (alkali treatment) and then 100 mM CaCl2, before heating at 700 °C (sample: ACaH-GM), with an optional final hot water immersion (sample: ACaHW-GM)--has apatite-forming ability in simulated body fluid. To confirm the in vivo bioactivity of these treated alloys, failure loads between implants and bone at 4, 8, 16, and 26 weeks after implantation in rabbits' tibiae were measured for untreated gum metal (UT-GM), ACaH-GM and ACaHW-GM, as well as pure titanium plates after alkali and heat treatment (AH-Ti). The ACaH-GM and UT-GM plates showed almost no bonding, whereas ACaHW-GM and AH-Ti plates showed successful bonding by 4 weeks, and their failure loads subsequently increased with time. The histological findings showed a large amount of new bone in contact with the surface of ACaHW-GM and AH-Ti plates, suggesting that the ACaHW treatment could impart bone-bonding bioactivity to a gum metal in vivo. Thus, with this improved bioactive treatment, these advantageous gum metals become useful candidates for orthopedic and dental devices. PMID:24293215

Tanaka, Masashi; Takemoto, Mitsuru; Fujibayashi, Shunsuke; Kawai, Toshiyuki; Yamaguchi, Seiji; Kizuki, Takashi; Matsushita, Tomiharu; Kokubo, Tadashi; Nakamura, Takashi; Matsuda, Shuichi

2014-03-01

324

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

2013-06-01

325

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

PubMed

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

Cheng, Rong; Lin, Lin; Zhang, Yongkui

2012-05-01

326

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

PubMed

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

Mirhosseini, Hamed; Amid, Bahareh Tabatabaee

2012-01-01

327

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

328

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 (2 mg 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

329

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

Microsoft Academic Search

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

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

2008-01-01

330

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 Brüning; Rolf Merget

2006-01-01

331

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

332

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

333

Partition of trypsin in aqueous two-phase systems of poly(ethylene glycol) and cashew-nut tree gum  

Microsoft Academic Search

The partition behaviour of trypsin in poly(ethylene glycol) (PEG)–cashew-nut tree gum aqueous two-phase systems has been characterized. The enzyme partitioned preferentially into the cashew-nut tree gum phase. Investigation on the effect of the molecular weight of the PEG, the pH of system and the tie-line length of the biphasic diagram lead to the conclusion that the system properties had little

L. A Oliveira; L. A Sarubbo; A. L. F Porto; G. M Campos-Takaki; E. B Tambourgi

2002-01-01

334

New aqueous two-phase system based on cashew-nut tree gum and poly(ethylene glycol)  

Microsoft Academic Search

The characterisation of a new system based on cashew-nut tree gum, a branched acidic heteropolysaccharide found in Brazil, and poly(ethylene glycol) (PEG) was studied. Phase diagrams are provided for the PEG–cashew-nut tree gum system. The influence of PEG molecular mass, tie-line length and pH on bovine serum albumin (BSA) partition was investigated. Protein partition coefficient was little influenced by changing

L. A Sarubbo; L. A Oliveira; A. L. F Porto; H. S Duarte; A. M. A Carneiro-Leão; J. L Lima-Filho; G. M Campos-Takaki; E. B Tambourgi

2000-01-01

335

Histological changes in the gum-resin producing cell system in Commiphora mukul Engl. induced by mechanical injury  

Microsoft Academic Search

The present paper describes alterations in the structure of bark, wood and gum-resin canals ofCommiphora mukul in response to mechanical injury. The samples of bark collected after 15 minutes of injury showed signs of visible distortion\\u000a or collapse of cell walls, specifically of the phloem cells near the gum-resin canals. The process of cell wall degradation\\u000a gets intensified after 45

G M Nair; Kamlesh R Patel; J J Shah

1981-01-01

336

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

2013-01-01

337

Gum Chewing Inhibits the Sensory Processing and the Propagation of Stress-Related Information in a Brain Network  

PubMed Central

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.

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

2013-01-01

338

Effect of gum tragacanth exuded by three Iranian Astragalus on mixed milk protein system during acid gelation.  

PubMed

The effects of various concentrations of three species of gum tragacanth on the gelation process, microstructure and viscoelastic properties of milk protein mixed gels acidified at 37°C by glucono-?-lactone (GDL) were investigated using dynamic rheometry and microscopy. According to rheological measurements, the addition of gum tragacanth in the range of 0.05-0.2% (w/w) into milk protein dispersions led to a weaker structure for the milk protein network, compared to the control sample. This weakening effect could be eliminated by adding 0.3% (w/w) gum tragacanth exudates from A. gossypinus; the compositional features of gum tragacanth may have been responsible for the improved protein-protein interactions, greater structural strength and reduced gelation time onset. It was determined by scanning electron microscopy that the addition of gum tragacanth at a low concentration caused the density of the matrix to increase, while an open structure was observed in the presence of a higher gum concentration. PMID:23146825

Nejatian, Mohammad; Hatami, Masoud; Mohammadifar, Mohammad Amin

2013-02-01

339

Abrasives in foods and their effect on intra-oral processing: a two-colour chewing gum study.  

PubMed

In this study we suggest that the presence of abrasives in food items lead to physiologic responses that reduce the amount of tooth loss because of abrasion. Subjects were presented with two pairs of two-colour chewing gum, one sample had 0.5 g of an abrasive powder added. Subjects were instructed to chew for 10 or 20 chewing strokes and then remove the gum. After removal the chewing gum was placed in a plastic bag and flattened. Each pair of gums was compared on the basis of the amount of mixing observed. In all cases the addition of the abrasive powder resulted in slower chewing and less mixing. Salivary flow rate increased from a resting value of 0.6 to 0.9 mL min(-1) when stimulated by the non-abrasive gum to 1.1 mL min(-1) with the abrasive gum. This difference was significant (P < 0.05). We conclude that when abrasive particles are detected in the mouth, less bolus manipulation is performed and more saliva is secreted. These responses would have the effect of reducing loss of tooth substance at the expense of reduced cominution of the food. PMID:15387836

Prinz, J F

2004-10-01

340

Functions of fenugreek gum with various molecular weights on the gelatinization and retrogradation behaviors of corn starch—1: Characterizations of fenugreek gum and investigations of corn starch\\/fenugreek gum composite system at a relatively high starch concentration; 15 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. Weight-average molecular weight Mw of fenugreek gum samples ranged from 7.5×104 to 20.7×105g\\/mol, whereas z-average root-mean-square radius of gyration Rg ranged between 16.3 and 122.3nm. The Flory exponent of 0.59 determined by the relationship between

Takahiro Funami; Yohei Kataoka; Sakie Noda; Mika Hiroe; Sayaka Ishihara; Iwao Asai; Rheo Takahashi; Katsuyoshi Nishinari

2008-01-01

341

Xanthan gum production by Xanthomonas campestris w.t. fermentation from chestnut extract.  

PubMed

Xanthomonas campestris w.t. was used for production of xanthan gum in fermentations with chestnut flour for the first time. Fermentations were carried out with either chestnut flour or its soluble sugars (33.5%) and starch (53.6%), respectively, at 28 degrees C and 200 rpm at initial pH 7.0 in flasks. The effect of agitation rate (at 200, 400, and 600 rpm) on xanthan gum production was also studied in a 2-L batch reactor. It was found that xanthan production reaches a maximum value of 3.3 g/100 mL at 600 rpm and 28 degrees C at 45 h. PMID:15304770

Liakopoulou-Kyriakides, M; Psomas, S K; Kyriakidis, D A

1999-12-01

342

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

PubMed

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

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

2013-01-01

343

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

PubMed

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

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

2013-01-30

344

Gum Arabic enhances paracellular transport of water in amphibian everted small intestinal segments.  

PubMed

Gum Arabic (GA) is known for its proabsorbent activity in normal intestine as well as in animal models of diarrhea. The aim of the study was to find the effect of GA on intestinal transport of water and possible route of absorption in frog everted gut sacs. D-Mannitol was used as a marker of paracellular transport to find the route of absorption. Everted gut sacs (n = 4,5) were placed in Ringer containing GA (2.5 g/L) with or without D-Mannitol (0.5 g/L), incubated for 1 hour and analysed for change in weights of the sacs and D-Mannitol uptake. There was significant increase in uptake of water and D-Mannitol in the presence of GA compared to controls (P < 0.05). Gum Arabic improves water uptake by the intestinal mucosa, possibly by opening the paracellular pathways. PMID:24617171

Pai, M Kirtana; Chetan, S; Rao, J Prakasa; Kumar, Ritesh; Kumar, Vikas; Kumar, Rishikesh

2013-01-01

345

Interpenetrating polymer network of locust bean gum-poly (vinyl alcohol) for controlled release drug delivery.  

PubMed

A novel interpenetrating polymer network (IPN) microspheres of locust bean gum (LBG) and poly (vinyl alcohol) (PVA) was developed for oral controlled release of buflomedil hydrochloride (BH) by emulsion crosslinking method using glutaraldehyde as crosslinker. The effects of gum-polymer ratio, concentration of crosslinker and internal phase viscosity were evaluated thoroughly. Drug entrapment efficiency, particle size distribution, swelling property and in vitro release characteristics with kinetic modelling of microspheres were evaluated. The microspheres were characterised by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), solid state C(13) NMR, X-ray diffraction study (XRD) and differential scanning colorimetry (DSC). The microspheres showed control release property without showing any incompatibility in IPN device. Hence, IPN microspheres of LBG and PVA can be used as a potential carrier for controlled oral delivery of highly water soluble drugs like BH. PMID:23544563

Kaity, Santanu; Isaac, Jinu; Ghosh, Animesh

2013-04-15

346

Identification of jasmonic acid and its methyl ester as gum-inducing factors in tulips.  

PubMed

The purpose of this study was to identify endogenous factors that induce gummosis and to show their role in gummosis in tulip (Tulipa gesneriana L. cv. Apeldoorn) stems. Using procedures to detect endogenous factors that induce gum in the stem of tulips, jasmonic acid (JA) and methyl jasmonate (JA-Me) were successfully identified using gas-liquid chromatography-mass spectrometry. Total amounts of JA and JA-Me designated as jasmonates in tulip stems were also estimated at about 70-80 ng/g fresh weight, using deuterium-labeled jasmonates as internal standards. The application of JA and JA-Me as lanolin pastes substantially induced gums in tulip stems with ethylene production. The application of ethephon, an ethylene-generating compound, however, induced no gummosis although it slightly affected jasmonate content in tulip stems. These results strongly suggest that JA and JA-Me are endogenous factors that induce gummosis in tulip stems. PMID:15654503

Skrzypek, Edyta; Miyamoto, Kensuke; Saniewski, Marian; Ueda, Junichi

2005-02-01

347

Fabrication of Triple-Layer Matrix Tablets of Venlafaxine Hydrochloride Using Xanthan Gum  

Microsoft Academic Search

The objective of present investigation was to develop venlafaxine hydrochloride-layered tablets for obtaining sustained drug\\u000a release. The tablets containing venlafaxine hydrochloride 150 mg were prepared by wet granulation technique using xanthan\\u000a gum in the middle layer and barrier layers. The granules and tablets were characterized. The in vitro drug dissolution study was conducted in distilled water. The tablets containing two lower

Mukesh C. Gohel; Shital H. Bariya

2009-01-01

348

Effect of xanthan gum on enhancing the foaming properties of soy protein isolate  

Microsoft Academic Search

The foaming properties of soy protein isolate (SPI) in the presence of xanthan gum (XG) were investigated. The XG solution\\u000a alone did not exhibit any foaming ability. The optimal foaming properties were obtained from the SPI-XG dispersion that contained\\u000a 0.1% SPI and 0.2% XG. This SPI-XG dispersion gave higher foaming capacity than that of SPI or egg white (PP<0.05). The

Y. R. Xie; N. S. Hettiarachchy

1998-01-01

349

Effect of xanthan gum on enhancing the foaming properties of whey protein isolate  

Microsoft Academic Search

The foaming properties of whey protein isolate (WPI) in the presence of xanthan gum (XG) were investigated. XG dispersion\\u000a did not exhibit any foaming properties. The optimal foaming overrun (FO), or the amount of air incorporated into the dispersion,\\u000a was obtained from the dispersion of 5% WPI and 0.05% XG at 949%. This WPI-XG dispersion had a significantly higher overrun

C. L. Mott; N. S. Hettiarachchy; M. Qi

1999-01-01

350

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

Microsoft Academic Search

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

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

2009-01-01

351

Effect of psyllium gum and wheat bran on spontaneous energy intake13  

Microsoft Academic Search

Energy intake, fecal energy output, and gastrointestinal symptoms were mea- sured in 12 females who consumed either '?-23 g\\/d supplementary fiber or a 4 g\\/d fiber control. Fiber supplements were crackers containing psyllium gum, wheat bran, or a combination of the two fiber sources. After 1 wk on the control cracker, subjects consumed the three high-fiber crackers and the control

June Stevens; David A Levitsky; Peter J VanSoest; James B Robertson; Heidi J Kalkwarf MNS; Daphne A Roe

352

Characterization of gum arabic fractions obtained by anion-exchange chromatography  

Microsoft Academic Search

Two samples of authentic gum arabic (A and B) have been fractionated by anion-exchange chromatography on DEAE-cellulose. The fractions were isolated by a step-wise increase in the ionic strength of the elution buffer. Samples A and B yielded five and six fractions, respectively. All of the fractions isolated were polydisperse containing varying proportions of the different Mr species associated with

Mohamed E. Osman; Alan R. Menzies; Beatriz Albo Martin; Peter A. Williams; Glyn O. Phillips; Timothy C. Baldwin

1995-01-01

353

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

Microsoft Academic Search

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

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

2006-01-01

354

Calcium alginate/gum Arabic beads containing glibenclamide: development and in vitro characterization.  

PubMed

This work investigates the development, optimization and in vitro characterization of calcium alginate/gum Arabic beads by an ionotropic gelation method for prolonged sustained release of glibenclamide. The effects of amount of sodium alginate and gum Arabic as independent process variables on the drug encapsulation efficiency and drug release were optimized and analyzed based on central composite design and response surface methodology. Increment in drug encapsulation efficiency and decrease in drug release were found with the increase of both the amounts of sodium alginate and gum Arabic, used as polymer-blend. These optimized beads showed high drug encapsulation efficiency (86.02±2.97%), and suitable sustained drug release pattern over prolonged period (cumulative drug release after 7 h of 35.68±1.38%). The average size of these formulated dried beads containing glibenclamide ranged from 1.15±0.11 to 1.55±0.19 mm. The in vitro dissolution of these beads showed prolonged sustained release of glibenclamide over 7 h, which followed first-order model (R(2)=0.9886-0.9985) with anomalous (non-Fickian) diffusion mechanism (release exponent, n=0.72-0.81). The swelling and degradation of the optimized beads were influenced by pH of test mediums. These beads were also characterized by SEM and FTIR spectroscopy for surface morphology and excipients-drug interaction analysis, respectively. These developed calcium alginate/gum Arabic beads containing glibenclamide could possibly be advantageous in terms of advanced patient compliance with reduced dosing interval. PMID:22947454

Nayak, Amit Kumar; Das, Biswarup; Maji, Ruma

2012-12-01

355

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

356

Influence of xanthan gum on rheological properties and freeze–thaw stability of tapioca starch  

Microsoft Academic Search

Physical properties and storage stability of tapioca starch (TS) can be modified using hydrocolloids. Xanthan gum (Xan) was investigated in this study for further application in TS-based products. The TS and TS\\/Xan mixtures at a total polysaccharide concentration of 5% w\\/w (db) were prepared. From RVA pasting profiles, pasting temperature, peak and final viscosities of TS pastes increased with increasing

Rungnaphar Pongsawatmanit; Suwapat Srijunthongsiri

2008-01-01

357

Toxicity studies in mice of Commiphora molmol oleo–gum–resin  

Microsoft Academic Search

Acute (24 h) and chronic (90 days) oral toxicity studies on Commiphora molmol (oleo–gum–resin) were carried out in mice. Dosages in acute study were 0.5, 1.0 and 3 g\\/kg, while in chronic study dosage was 100 mg\\/kg per day. All external morphological, biochemical and haematological changes, in addition to body and vital organ weights were recorded. There was no significant

R. M. Rao; Z. A. Khan; A. H. Shah

2001-01-01

358

Method of inhibiting crosslinking of aqueous xanthan gums in the presence of ferric acid ions  

Microsoft Academic Search

The cross linking of aqueous xanthan gums in the presence of ferric ions is inhibited or prevented by adding a soluble alkanoic and\\/or alkenoic acid having at least 4 carbon atoms and bearing at least 2 hydroxyl groups per molecule, and\\/or a soluble salt of ..gamma..-lactone. This combination of ingredients forms gelled acid compositions which are useful in acidizing treatments

Crowe

1982-01-01

359

Chewing gum of antimicrobial decapeptide (KSL) as a sustained antiplaque agent: Preformulation study  

Microsoft Academic Search

The purpose of this study was to investigate the potential of KSL, an antimicrobial decapeptide, which has been shown to inhibit the growth of oral bacterial strains associated with caries development and plaque formation, to act as an antiplaque agent in a chewing gum formulation. A reversed-phase high-performance liquid chromatography method was developed for KSL and found to be stability-indicating.

Dong Hee Na; Jabar Faraj; Yilmaz Capan; Kai P. Leung; Patrick P. DeLuca

2005-01-01

360

Expression of the gum operon directing xanthan biosynthesis in Xanthomonas campestris and its regulation in planta.  

PubMed

The gum gene cluster of Xanthomonas campestris pv. campestris comprises 12 genes whose products are involved in the biosynthesis of the extracellular polysaccharide xanthan. These genes are expressed primarily as an operon from a promoter upstream of the first gene, gumB. Although the regulation of xanthan synthesis in vitro has been well studied, nothing is known of its regulation in planta. A reporter plasmid was constructed in which the promoter region of the gum operon was fused to gusA. In liquid cultures, the expression of the gumgusA reporter was correlated closely with the production of xanthan, although a low basal level of beta-glucuronidase activity was seen in the absence of added carbon sources when xanthan production was very low. The expression of the gumgusA fusion also was subject to positive regulation by rpfF, which is responsible for the synthesis of the diffusible signal factor (DSF). The expression of the gumgusA fusion in bacteria recovered from inoculated turnip leaves was maximal at the later phases of growth and was subject to regulation by rpfF. These results provide indirect support for the operation of the DSF regulatory system in bacteria in planta. PMID:11386372

Vojnov, A A; Slater, H; Daniels, M J; Dow, J M

2001-06-01

361

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

2000-01-01

362

Bioadhesive Controlled Metronidazole Release Matrix Based on Chitosan and Xanthan Gum  

PubMed Central

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

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

2010-01-01

363

Preparation and characterization of pH-responsive guar gum microspheres.  

PubMed

Guar gum, being the natural polymer is renewable, nontoxic, biocompatible and biodegradable. Therefore, it is the perfect material to formulate particulates or microspheres for potential applications in pharmaceutical. The formulation of material in nano/microsphere scale offers new rich in application potential. In view of that, novel biodegradable and pH-sensitive hydrogels composed of pH-sensitive methacrylic acid (MAc) and a biodegradable guar gum were synthesized by grafting reactions. Water-in-oil (w/o) emulsion method was used to direct the pH-sensitive material in microspheres shape using bi-functional glutaraldehyde (GA) as crosslinker. The synthesized microspheres were characterized by FTIR and SEM (different magnification). The swelling ratios of hydrogels in buffer solutions showed a pH-dependent profile at physiological pH. In vitro release data was analyzed using Fick's law, which indicated swelling controlled super case II transport of BSA through the synthesized microspheres. Therefore, in conclusion, as ascertained from the results the introduction of -COOH moieties along the guar gum chain drastically increases the end-use performance due to pH-sensitivity. PMID:24099940

Sharma, Shitika; Kaur, Jasvinder; Sharma, Gaurav; Thakur, Kamal Kishor; Chauhan, Ghanshyam S; Chauhan, Kalpana

2013-11-01

364

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

PubMed

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

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

2014-06-01

365

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

PubMed Central

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

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

2014-01-01

366

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

PubMed

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

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

2006-01-01

367

Pressure cell assisted solubilization of xyloglucans: tamarind seed polysaccharide and detarium gum.  

PubMed

To improve the solubilization of two water-soluble xyloglucans, tamarind seed polysaccharide and detarium gum, by reducing substantially molecular aggregation, a "pressure cell" heating method was used. Conditions allowing solubilization and chain depolymerization were produced by varying appropriately the pressure, time, and temperature applied. The various MW fractions of solubilized xyloglucans were characterized by capillary viscometry and light scattering techniques in order to extract, with reliability, fundamental macromolecular parameters. Mark-Houwink and Flory exponents were found to be 0.67 +/- 0.04 and 0.51 +/- 0.06, respectively for both xyloglucan data combined, consistent with linear random coil behavior. A detailed analysis of the data seems to suggest that tamarind gum solutions are slightly perturbed by the effect of excluded volume, whereas detarium gum samples are close to the theta state. Chain flexibility parameters such characteristic ratio, C( proportional, variant ), and persistence length, L(p), were calculated for tamarind and detarium using the Burchard-Stockmayer-Fixman (BSF) geometric method. L(p) values of 6-8 nm were estimated for xyloglucans. The seemingly linear structure of tamarind and detarium, as suggested by the value of the Mark-Houwink and Flory exponents obtained, follows from analysis of the data by the classical Zimm method but not when employing the square root or Berry method which suggests a more branched chain profile. This was the approach adopted in our previous work on the characterization of detarium samples. PMID:12741801

Picout, David R; Ross-Murphy, Simon B; Errington, Neil; Harding, Stephen E

2003-01-01

368

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

369

Gum arabic glycoprotein is a twisted hairy rope. A new model based on O-galactosylhydroxyproline as the polysaccharide attachment site  

Microsoft Academic Search

Separation of the wound exudate from Acacia senegal (L.) Willd., gum arabic, on a preparative Superose-6 column gave two major fractions: a high molecular weight gum arabic glyco-protein (GAGP) containing about 90% carbohydrate and a lower molecular weight heterogeneous gum arabic polysaccharide fraction. Hydrogen fluoride-deglycosylation of GAGP gave a large hydroxyproline-rich polypeptide backbone (dGAGP). Alkaline hydrolysis of GAGP showed that

Wu Qi; C. Fong; D. T. A. Lamport

1991-01-01

370

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

371

Effects of guar gum and cellulose on glucose absorption, hormonal release and hepatic metabolism in the pig  

NASA Technical Reports Server (NTRS)

Six Large White pigs (mean body-weight 59 (SE 1.7) kg) were surgically fitted with permanent catheters in the portal vein, the brachiocephalic artery and the right hepatic vein, as well as with electromagnetic flow probes around the portal vein and the hepatic artery, and allowed to recover. The non-anaesthetized animals were given a basal non-fibre diet (diet A) alone or together with 60 g guar gum/kg (diet B) or 150 g purified cellulose/kg (diet C) by substitution for mica. The diets were given for weekly periods and according to a replicated 3 x 3 Latin square design. On the last day of each such adaptation period, test meals of 800 g were given before blood sampling. Sampling was continued for 8 h. Guar gum strongly reduced glucose apparent absorption without changing the absorption and the hepatic uptake profiles. Production rates of insulin, gastric inhibitory polypeptide and insulin-like growth factor-1 (IGF-1) were lowest after guar gum ingestion. However, the reductions in peripheral blood insulin levels caused by guar gum were not associated with a change in hepatic insulin extraction. IGF-1 appeared to be strongly secreted by the gut, whereas the liver had a net uptake of the peptide. Ingestion of guar gum increased the hepatic extraction coefficient of gut-produced IGF-1. Guar gum ingestion appeared also to decrease glucagon secretion. Cellulose at the level consumed had very few effects on the variables considered. It is suggested that the modulation of intestinal mechanisms by guar gum was sufficient to mediate the metabolic effects described.

Nunes, C. S.; Malmlof, K.

1992-01-01

372

Evaluation of the binder effects of the gum mucilages of Cissus populnea and Acassia senegal on the mechanical properties of paracetamol tablets  

Microsoft Academic Search

A comparative study has been carried out to investigate the binder effects of the gums of Cissus populnea and Accasia senegal on the mechanical properties of paracetamol tablets. Tablet mechanical properties evaluated include the packing fraction (Pf), the tensile strength (T) and the brittle fracture tendency (BFI). Varying concentrations of the gum mucilage ranging from 1 - 15% (w\\/v) was

F. E. Eichie

2007-01-01

373

Food hydrocolloids control the gelatinization and retrogradation behavior of starch. 2a. Functions of guar gums with different molecular weights on the gelatinization behavior of corn starch  

Microsoft Academic Search

Gelatinization behavior of starch in an aqueous system was studied in the presence or absence of various guar gum samples with different molecular weights in order to clarify the difference in functions of each guar to starch. Some native corn starches with different amylose\\/amylopectin ratios were used to clarify which fraction of starch the gums act on. Weight-average molecular weight

Takahiro Funami; Yohei Kataoka; Toshio Omoto; Yasunori Goto; Iwao Asai; Katsuyoshi Nishinari

2005-01-01

374

A study of the effects of aeration and agitation on the properties and production of xanthan gum from crude glycerin derived from biodiesel using the response surface methodology.  

PubMed

The effects of aeration and agitation on the properties and production of xanthan gum from crude glycerin biodiesel (CGB) by Xanthomonas campestris mangiferaeindicae 2103 were investigated and optimized using a response surface methodology. The xanthan gum was produced from CGB in a bioreactor at 28 °C for 120 h. Optimization procedures indicated that 0.97 vvm at 497.76 rpm resulted in a xanthan gum production of 5.59 g L(-1) and 1.05 vvm at 484.75 rpm maximized the biomass to 3.26 g L(-1). Moreover, the combination of 1.05 vvm at 499.40 rpm maximized the viscosity of xanthan at 0.5% (m/v), 25 °C, and 25 s(-1) (255.40 mPa s). The other responses did not generate predictive models. Low agitation contributed to the increase of xanthan gum production, biomass, viscosity, molecular mass, and the pyruvic acid concentration. Increases in the agitation contributed to the formation of xanthan gum with high mannose concentration. Decreases in the aeration contributed to the xanthan gum production and the formation of biopolymer with high mannose and glucose concentrations. Increases in aeration contributed to increased biomass, viscosity, and formation of xanthan gum with greater resistance to thermal degradation. Overall, aeration and agitation of CGB fermentation significantly influenced the production of xanthan gum and its properties. PMID:24435765

de Jesus Assis, Denilson; Brandão, Líllian Vasconcelos; de Sousa Costa, Larissa Alves; Figueiredo, Tamiris Vilas Boas; Sousa, Luciane Santos; Padilha, Francine Ferreira; Druzian, Janice Izabel

2014-03-01

375

Clinical effectiveness of a potassium chloride containing chewing gum in the treatment of hypersensitive teeth.  

PubMed

Dental hypersensitivity has been observed in an increasing number of younger patients over the past few decades. The reasons for this include forced or false tooth-brushing techniques, and abrasions caused by bruxism or orthodontic procedures. The aim of the present study was to assess the possible benefits of a potassium chloride (KCl) containing chewing gum in dental hypersensitivity. The study population consisted of 59 selected university students (age: 25 +/- 4.4 years). Each subject suitable for entry into the study had more than 3 teeth sensitive to thermal stimulation (air stimulus range of 30-80 mm on a 100mm visual analogue scale (VAS), and showed signs of facial/cervical erosion, abrasion and/or gingival recession. Exclusion criteria were daily doses of medication, teeth with deep restorations, a gingival score of > 2, or periodontal surgery within the past 6 months. The total number of hypersensitive teeth was 217. Over a period of 3 weeks the subjects brushed with a non-desensitising toothpaste and, in addition, used the KCl chewing gum up to 6 times daily for 10 min on each occasion. This was followed by a period of 3 weeks of non-desensitising toothpaste use alone. The subjects were questioned on the severity of intraoral pain and asked to indicate the intensity of the pain on the VAS (baseline, 1, 3 and 6 weeks). Mean thermal sensitivity at baseline was 54.5 +/- 9 mm. There was a drop to 40.8 mm ( 1.9) after 1 week and to 28.6 mm (+/- 2) after 3 weeks. The reduction was statistically significant (p <0.001) at both measurement points. The mean rating increased to 29.1 mm after 6 weeks. The results of this study demonstrate that the daily use of a KCl containing chewing gum is a useful non-invasive method of reducing dental hypersensitivity over an extended period of time. PMID:11726307

Krahwinkel, T; Theiss, P; Willershausen, B

2001-11-20

376

What can we learn from the saga of chitosan gums in hyperphosphatemia therapy?  

PubMed

Control of high serum phosphorus, a marker of poor outcome, is still a poorly achieved goal in dialysis therapy. Therefore, the 2009 study (Savica et al., J Am Soc Nephrol 20: 639-644, 2009) showing a significant drop of serum phosphate (2.35 mg/dl) after only 2 weeks of chewing a chitosan-containing gum two times per day was received with great hopes by the renal community. Chitosan is a polymer of glucosamine, similar to sevelamer, which allegedly would bind phosphate present in high concentrations in the saliva of renal patients. Recent randomized studies, however, have been unable to duplicate these results. A systematic and detailed quantitative analysis of the available data was performed. It concluded that the amount of chitosan contained in the chewing gum (20 mg) is too little to account for the originally observed reduction in serum phosphate and be of any use as a phosphate binding agent in the management of hyperphosphatemia. It was postulated that the original marked drop in serum phosphate may have been caused by the Hawthorne effect, which is frequently observed in nonrandomized clinical trials. Two important lessons derived from this analysis are emphasized. The first lesson is the demonstration of the importance of randomized, placebo-controlled studies in clinical research. If randomization had been performed in the original study, the Hawthorne effect would have been detected. The second lesson is showing the importance of quantitative analysis, which in this case, would have avoided the time and effort expended in several randomized clinical trials that eventually concluded the ineffectiveness of the chitosan-containing chewing gums as a phosphate binder. PMID:24408115

Oh, Man S; Uribarri, Jaime

2014-05-01

377

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

378

Microwave assisted synthesis of guar gum grafted sodium acrylate/cloisite superabsorbent nanocomposites: reaction parameters and swelling characteristics.  

PubMed

In this study, superabsorbent nanocomposites of guar gum grafted sodium acrylate have been synthesized via both microwave and conventional techniques. The reaction parameters of both techniques were optimized and the microwave assisted method was proved to have higher grafting yield with lesser time of reaction as compared to the conventional method. X-ray diffraction and scanning electron microscopy analyses revealed that cloisite was exfoliated and uniformly dispersed in guar gum grafted sodium acrylate matrix. The results show that introducing cloisite into the guar gum grafted sodium acrylate network improved the swelling capability and the swelling rate of the superabsorbent nanocomposite was found to be enhanced at an optimal loading of 10% cloisite. The nanocomposites showed high water absorbency within a wide pH range. Preliminary studies on crystal violet dye removal showed promising results. PMID:24530336

Likhitha, M; Sailaja, R R N; Priyambika, V S; Ravibabu, M V

2014-04-01

379

Sonication-based improvement of the physicochemical properties of Guar Gum as a potential substrate for modified drug delivery systems.  

PubMed

Guar Gum is a natural polysaccharide that, due to its physicochemical properties, is extensively investigated for biomedical applications as a matrix for modified drug delivery, but it is also used in the food industry as well as in cosmetics. A commercial sample of Guar Gum was sonicated for different periods of time, and the reduction in the average molecular weight was monitored by means of viscometric measurements. At the same time, the rheological behaviour was also followed, in terms of viscoelasticity range, flow curves, and mechanical spectra. Sonicated samples were used for the preparation of gels in the presence of borate ions. The effect of borax on the new samples was investigated by recording mechanical spectra, flow curves, and visible absorption spectra of complexes with Congo Red. The anisotropic elongation, observed in previous studies with tablets of Guar Gum and borax, was remarkably reduced when the sonicated samples were used for the preparation of the gels. PMID:23984426

Ansari, Siddique Akber; Matricardi, Pietro; Cencetti, Claudia; Di Meo, Chiara; Carafa, Maria; Mazzuca, Claudia; Palleschi, Antonio; Capitani, Donatella; Alhaique, Franco; Coviello, Tommasina

2013-01-01

380

Structure of arabinogalactan-protein from Acacia gum: from porous ellipsoids to supramolecular architectures.  

PubMed

The structure of the arabinogalactan-protein (AGP) fraction of the gum exudate of Acacia senegal (gum Arabic) isolated from hydrophobic interaction chromatography was investigated using HPSEC-MALLS, small angle neutron scattering and TEM observations. Literature reported that the AGP structure of gum Arabic adopts a very compact conformation in solution due to the attachment of short arabinoside side chains and much larger blocks of carbohydrate to the polypeptidic backbone. The present study revealed that AGP in solution had a weight average molecular weight Mw of 1.86×10(6) g mol(-1) and a radius of gyration Rg of 30 nm. In addition, two exponent values were identified in the Rg, [?], Rh and ? vs. Mw relationships highlighting two types of conformations depending on the molecular weight range considered: a low molar mass population with long-chain branching and a compact conformation and a high molar mass population with short-chain branching and an elongated conformation. AGP would behave in solution as a branched or hyper-branched polymer with conformations ranging from globular to elongated shape depending on the size of the carbohydrate branches. Small angle scattering form factor revealed an elongated average conformation corresponding to a triaxial ellipsoid while inverse Fourier transform of the scattering form factor gave a maximum dimension for AGP of 64 nm. Transmission electron microscopy highlighted the existence of two types of flat objects with thicknesses below 3-5 nm, single particles with a more or less anisotropic spheroidal shape and aggregated structures with a more elongated shape. A remarkable feature of all particle morphologies was the presence of an outer structure combined to an inner more or less porous network of interspersed chains or interacting structural blocks, as previously found for the arabinogalactan (AG) main molecular fraction of Acacia gum. However, clear differences were observed in the density and morphology of the inner porous network, probably highlighting differences in the degree of branching. The existence of assembled AG as part of the AGP family was confirmed using TEM micrographs at high resolution. Fused AGP dimers, trimers, tetramers and multimers were also identified. These molecular assemblies questioned about the nature of interactions involved. PMID:24751048

Renard, D; Garnier, C; Lapp, A; Schmitt, C; Sanchez, C

2012-09-01

381

Designing of silver nanoparticles in gum arabic based semi-IPN hydrogel.  

PubMed

Semi-interpenetrating network (SISH-GA) composed of gum arabic and crosslinked copolymer of poly(2-hydroxyethyl methacrylate-co-acrylic acid) was synthesized in the presence of initiator ammonium persulfate (APS), crosslinker N,N'-methylene bis acrylamide (MBA), catalyzed by [CuSO4/glycine] chelate complex and finally loaded nanoparticle inside the networks via in situ reduction of silver nitrate (AgNO3) using trisodium citrate (Na3C6H5O7) as reducing agent. Characterization of the product was performed along with its degradability in Escherichia coli medium. PMID:20060413

Gils, Palapparambil Sunny; Ray, Debajyoti; Sahoo, Prafulla Kumar

2010-03-01

382

Phonons and phase stability in Ti-V approximants to gum metal  

NASA Astrophysics Data System (ADS)

The stability of competing phases within body-centered-cubic Ti-V approximants to gum metal is considered from the perspective of phonon dispersion. Phonons are associated with the potential to form the ? and ?'' phases. It is argued that alloys can be designed to be linearly stable with respect to the formation of both phases, even as the ideal shear strength approaches zero. The reduction in ideal strength is associated with softening of the phonons along ?-N and is reflected in diffuse-scattering diffraction experiments.

Hanlumyuang, Y.; Sankaran, R. P.; Sherburne, M. P.; Morris, J. W., Jr.; Chrzan, D. C.

2012-04-01

383

Dislocation mobility in gum metal ?-titanium alloy studied via insitu transmission electron microscopy  

NASA Astrophysics Data System (ADS)

In situ tensile tests in a transmission electron microscope were carried out on a “Gum Metal” ?-titanium alloy. Conventional dislocation slip was observed to be the only mechanism occurring during the plastic deformation. The low mobility of screw dislocations was shown to be due to their core structure configuration. Nanometer-sized obstacles were also present but have a weaker effect on the dislocation mobility. The density of these obstacles and the variation in energy due to the core structure of screw dislocations were measured and compared to theoretical data in the literature.

Castany, Philippe; Besse, Magali; Gloriant, Thierry

2011-07-01

384

Green synthesis, characterization and catalytic activity of palladium nanoparticles by xanthan gum  

NASA Astrophysics Data System (ADS)

Here, we report the synthesis, characterization and catalytic evaluation of palladium nanoparticles (PdNPs) using xanthan gum, acting as both reducing and stabilizing agent without using any synthetic reagent. The uniqueness of our method lies in its fast synthesis rates using hydrothermal method in autoclave at a pressure of 15 psi and at 120 °C temperature by 10 min time. The formation and size of the PdNPs were characterized by UV-visible spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and transmission electron microscopy. The catalytic activity of PdNPs was evaluated on the reduction of 4-nitrophenol to 4-aminophenol by sodium borohydride using spectrophotometry.

Santoshi kumari, Amrutham; Venkatesham, Maragoni; Ayodhya, Dasari; Veerabhadram, Guttena

2014-05-01

385

Functions of fenugreek gum with various molecular weights on the gelatinization and retrogradation behaviors of corn starch—2: 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

386

Mapping Land Use Land Cover Using NDVI in a Semi-arid Areas in Gum Arabic Belt, Sudan  

NASA Astrophysics Data System (ADS)

Gum arabic belt is most important region in Sudan with producing gum arabic in global level. Each land cover type has different spectral characteristics, absorbing some frequencies of light and reflecting others. With an understanding of the reflectance characteristics and some ground observations, it is possible to use remotely sensed data to make inferences about the type of land cover and land use. The objective of this study is to measure and classify the vegetation cover in semi-arid area in gum arbic belt in Sudan using NDVI. The remotely sensed data used in this study were NDVI images created from Terra-ASTER (2007), ETM+ (1999) and TM (1985) images of the study area (35x35 km) in the gum arabic in Kordofan region, Sudan. The values of the NDVI were examined and evaluated on pixel-by-pixel using ERDAS software and the training points collected from the field work. Supervised classification of a multi-temporal Normalised Difference Vegetation Index (NDVI) data set was used to analyse the temporal land-cover changes. The magnitude of green vegetation was quantified to several levels and separated from other classes using the advantage of the stratification of cover classes as a function of the NDVI. Using this stratification, the study found many similarities in the value of NDVI in land use land cover classes in gum arabic belt region. Four LULC classes were indicated using the range (0.184 and below) to represent the bare and farm lands, (0.185 -0.254) represents the grass and bush lands, (0.255 -0.334) represents forest dominated by Hashab trees (0.335 and high) represents mixed woodlands. Maximum NDVI values (0.90) were found in images 1972. Further research is needed to fully determine the spatial and temporal range of the NDVI values over non-vegetated and partially vegetated areas in semi-arid areas. Key words: vegetation cover, NDVI, gum arabic belt, mapping

Elnour Adam, Hassan; Csaplovics, Elmar

387

Nutritional benefits of Crematogaster mimosae ants and Acacia drepanolobium gum for patas monkeys and vervets in Laikipia, Kenya.  

PubMed

Patas monkeys (Erythrocebus patas) are midsized primates that feed extensively on the gum of Acacia drepanolobium and the ants are housed in swollen thorns of this Acacia. Their diet resembles that expected more of smaller bodied primates. Patas monkeys are also more like smaller bodied primates in reproducing at high rates. We sought to better understand the convergence of patas monkeys with smaller bodied primates by comparing their feeding behavior on ants and gum with that of closely related, sympatric vervets (Chlorocebus pygerythrus), and analyzing the nutrient content of the gum of A. drepanolobium and of Crematogaster mimosae, the most common ant species eaten by patas monkeys in Laikipia, Kenya. All occurrences of feeding and moving during focal animal sampling revealed that 1) patas monkeys seek A. drepanolobium gum but vervets avoid it; 2) both species open swollen thorns most often in the morning when antsare less active; 3) patas monkeys continually feed onswollen thorns and gum while moving quickly throughout the day, whereas vervets reduce their consumption of these items and their travel rate at mid-day, and; 4) vervets eat young swollen thorns at a higher rate than patas monkeys. Patas monkeys are able to spend little time acquiring substantial amounts of energy, protein, and minerals from A. drepanolobium gum and C. mimosae ants each day. These findings, when coupled with evidence of causes of infant and adult female mortality, suggest that reproductive success of female patas monkeys is more immediately affected by illness, disease, interactions between adults and infants, and access to water than by food. PMID:23280312

Isbell, Lynne A; Rothman, Jessica M; Young, Peter J; Rudolph, Kathleen

2013-02-01

388

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

Microsoft Academic Search

Background  Gum of Chios mastic (Pistacia lentiscus var. chia) is a natural antimicrobial agent that has found extensive use in pharmaceutical products and as a nutritional supplement.\\u000a The molecular mechanisms of its anti-inflammatory activity, however, are not clear. In this work, the potential role of antioxidant\\u000a activity of Chios mastic gum has been evaluated.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Scavenging of superoxide radical was investigated by

Angelike Triantafyllou; Alfiya Bikineyeva; Anna Dikalova; Rafal Nazarewicz; Stamatios Lerakis; Sergey Dikalov

2011-01-01

389

Spreading of dislocation cores in elastically anisotropic body-centered-cubic materials: The case of gum metal  

NASA Astrophysics Data System (ADS)

The structure of dislocation cores in elastically anisotropic materials is considered. A definition of the dislocation core radius is introduced and used to demonstrate that the elastic anisotropy that develops near a composition driven phase transition, such as that predicted for the Ti-Nb based alloys known as gum metals, can drive dislocation core radii to infinity. Under these circumstances, dislocation cores necessarily overlap. The atomic scale structures predicted to arise from core overlap in Ti-V alloys are reminiscent of nanodisturbances observed in gum metals.

Chrzan, D. C.; Sherburne, M. P.; Hanlumyuang, Y.; Li, T.; Morris, J. W., Jr.

2010-11-01

390

Exercise as an adjunct to nicotine gum in treating tobacco dependence among women  

PubMed Central

This was the first randomized, controlled smoking cessation trial assessing the efficacy of an exercise intervention as an adjunct to nicotine gum therapy in comparison to both equal contact control and standard care control conditions. Sedentary female smokers aged 18-55 were provided with nicotine gum treatment along with brief behavioral counseling and were randomized into one of these three behavioral adjunct conditions. In the “intent-to-treat” sample (N=182), at end of treatment and at one-year follow up, there were clear, but non-significant, trends in univariate analyses in which the exercise and equal contact control conditions both had higher rates of abstinence than the standard care control. However, when adjusting for other predictors of relapse in a multiple logistic regression, both exercise and equal contact control showed an advantage over standard care control in avoiding early relapse (i.e., after 1 week). In a multivariate survival model adjusting for other predictors, the equal contact condition had a significantly lower likelihood of relapse compared to the standard care condition and there was a near significant trend in which exercise offered an advantage over standard care as well. While these findings suggest a slightly improved likelihood of abstinence with exercise compared with standard care, exercise did not differ from equal contact control in its efficacy. Potential explanations for these equivalent levels of efficacy and implications for the findings are discussed.

Kinnunen, Taru; Leeman, Robert F.; Korhonen, Tellervo; Terwal, Donna M.; Garvey, Arthur J.; Quiles, Zandra N.; Hartley, L. Howard

2013-01-01

391

New intrinsic mechanism on gum-like superelasticity of multifunctional alloys.  

PubMed

Ti-Nb-based Gum Metals exhibit extraordinary superelasticity with ultralow elastic modulus, superior strength and ductility, and a peculiar dislocation-free deformation behavior, most of which challenge existing theories of crystal strength. Additionally, this kind of alloys actually displays even more anomalous mechanical properties, such as the non-linear superelastic behavior, accompanied by a pronounced tension-to-compression asymmetry, and large ductility with a low Poisson's ratio. Two main contradictory arguments exist concerning the deformation mechanisms of those alloys, i.e., formation of reversible nanodisturbance and reversible martensitic transformation. Herein we used the in-situ synchrotron high-energy X-ray scattering technique to reveal the novel intrinsic physical origin of all anomalous mechanical properties of the Ti-24Nb-4Zr-8Sn-0.10O alloy, a typical gum-like metal. Our experiments provide direct evidence on two different kinds of interesting, stress-induced, reversible nanoscale martensitic transitions, i.e., the austenitic regions with B2 structure transform to ?? martensite and those with BCC structure transform to ? martensite. PMID:23831664

Liu, Jia-Peng; Wang, Yan-Dong; Hao, Yu-Lin; Wang, Yunzhi; Nie, Zhi-Hua; Wang, Dong; Ren, Yang; Lu, Zhao-Ping; Wang, Jinguo; Wang, Haoliang; Hui, Xidong; Lu, Ning; Kim, Moon J; Yang, Rui

2013-01-01

392

GumPack: a personal health assistant with reconfigurable surface components.  

PubMed

Wearable and everyday-carry medical devices can improve quality of life for individuals that need frequent health monitoring. Such tools can supplement ubiquitous home care environments populated with medical sensors, extending the reach of these environments and increasing the freedom of their occupants. This paper presents the concept design for an everyday-carry medical device called a 'GumPack': a small cuboid-shaped device that offers wireless connectivity and plug-and-play surface components, where a component can be a biomedical sensor or a wireless network coordinator that manages a body area network. This geometrical layout optimizes access to surface-based medical hardware mounted on a small form factor. The device offers substantive computing power, supports local component reconfigurability, and promotes interoperability with medical device coordination environments. The GumPack is envisioned to be a personal health assistant carried in a pocket or handbag that can operate alone or interface to, e.g., a cell phone. PMID:23502254

Li, Kejia; Warren, Steve

2013-01-01

393

Guar gum-g-N,N'-dimethylacrylamide: synthesis, characterization and applications.  

PubMed

The graft copolymerization of N,N'-dimethylacrylamide onto guar gum initiated by potassium peroxymonosulphate/glycolic acid redox pair in an aqueous medium was studied gravimetrically under a nitrogen atmosphere. Grafting ratio, grafting efficiency and add on increase on increasing the concentration of potassium peroxymonosulphate (8.0 × 10(-3) to 24.0 × 10(-3) mol dm(-3)) and glycolic acid concentration (4.4 × 10(-3) to 7.6 × 10(-3) mol dm(-3)). On increasing the hydrogen ion concentration from 4 × 10(-3) to 12.0 × 10(-3) mol dm(-3), grafting ratio, efficiency, add on and conversion were increased. Maximum grafting was obtained when guar gum and N,N'-dimethylacrylamide concentration were 1.0 × 10(-2) g dm(-3) and 14.0 × 10(-2) mol dm(-3), respectively. An increase in temperature from 25 °C to 45 °C, the grafting ratio increases but conversion and homopolymer decrease. The optimum time period for graft copolymerization was 2h. The graft copolymers were characterized by IR spectroscopy and thermogravimetric analysis. PMID:24274508

Pandey, Vijay Shankar; Verma, Shiv Kumar; Yadav, Mithilesh; Behari, Kunj

2014-01-01

394

Xanthan gum production under several operational conditions: molecular structure and rheological properties*  

PubMed

Xanthan gum production under several operational conditions has been studied. Temperature, initial nitrogen concentration and oxygen mass transfer rate have been changed and average molecular weight, pyruvilation and acetylation degree of xanthan produced have been measured in order to know the influence of these variables on the synthesised xanthan molecular structure. Also, xanthan gum solution viscosity has been measured, and rheological properties of the solutions have been related to molecular structure and operational conditions. The Casson model has been employed to describe the rheological behaviour. The parameter values of the Casson model, tau(0) and K(c), have been obtained for each polysaccharide synthesised under different operational conditions. Both pyruvilation and acetylation degrees and average molecular weight of xanthan increase with fermentation time at any operating conditions. Xanthan molecules with the highest average molecular weight have been obtained at 25 degrees C. Nevertheless, at this temperature acetate and pyruvate radical concentration are lowest. Nitrogen concentration in broth does not show any clear influence over xanthan average molecular weight, although with high nitrogen source concentration xanthan with low pyruvilation degree is produced. PMID:10689089

Casas; Santos; García-Ochoa

2000-02-01

395

Heterologous expression of a hyperthermophilic alpha-amylase in xanthan gum producing Xanthomonas campestris cells.  

PubMed

A hyperthermophilic alpha-amylase encoding gene from Pyrococcus woesei was transferred and expressed in Xanthomonas campestris ATCC 13951. The heterologous alpha-amylase activity was detected in the intracellular fraction of X. campestris and presented similar thermostability and catalytic properties with the native P. woesei enzyme. The recombinant alpha-amylase was found to be stable at 90 degrees C for 4 h and within the same period it retained more than 50% of its initial activity at 110 degrees C. Furthermore, X. campestris transformants produced similar levels of recombinant alpha-amylase activity regardless of the carbon source present in the growth medium, whereas the native X. campestris alpha-amylase production was highly dependent on starch availability and it was suppressed in the presence of glucose or other reducing sugars. On the other hand, xanthan gum yield, which appeared to be similar for both wild type and recombinant X. campestris strains, was enhanced at higher starch or glucose concentrations. Evidence presented in this study supports that X. campestris is a promising cell factory for the co-production of recombinant hyperthermophilic alpha-amylase and xanthan gum. PMID:18401740

Konsoula, Zoe; Liakopoulou-Kyriakides, Maria; Perysinakis, Angelos; Chira, Panayiota; Afendra, Amalia; Drainas, Constantin; Kyriakidis, Dimitrios A

2008-05-01

396

Release of peppermint flavour compounds from chewing gum: effect of oral functions.  

PubMed

During chewing, the oral cavity functions like a bellow, forcing volatile flavour compounds into the exhaling air to the nasal compartment. Accordingly, we hypothesised that flavour release from chewing gum is predominantly governed by chewing frequency (CF), although other oral functions, like masseter muscle activity (MMA), chewing force (CFO), and saliva flow rate (SFR), may also play a role. In 10 healthy young males, the retronasal expired air of menthol and menthone from peppermint-flavoured (2%) chewing gum was determined as functions of CF, SFR, MMA, and CFO. The experimental setup comprised three separate series of a 4-min chewing period. These series differed only with respect to CF, i.e., habitual frequency, and 60 and 88 strokes/min. Results showed that more than 50% of the released menthol and menthone could be retrieved in the expired air and saliva. After 2-min of chewing, the concentration of flavour compounds in the expired air depended primarily on MMA and CF, becoming higher with increased MMA and CF. The concentration of flavour compounds in saliva depended primarily on SFR and the duration of the chewing task, becoming lower with high SFR and prolonged chewing duration. An increased volume of saliva in the mouth seemed to keep more flavour compounds in the aqueous phase, thereby diminishing the release via the retronasal route. In conclusion, flavour release to the retronasal compartment was dependent on MMA and CF and influenced by the volume of saliva present in the mouth. PMID:15276819

Haahr, Anne-Mette; Bardow, Allan; Thomsen, Carsten E; Jensen, Siri B; Nauntofte, Birgitte; Bakke, Merete; Adler-Nissen, Jens; Bredie, Wender L P

2004-09-15

397

Allergic contact dermatitis caused by gum rosin and wood rosin in Tako-no-Suidashi ointment.  

PubMed

Tako-no-Suidashi ointment (TSO) is an old Japanese over-the-counter drug, used for the drainage of infectious pustular disease, such as furuncles, carbuncles and infectious atheroma, although whether it works well or not is unknown. The ingredients of the TSO compound commonly include rapeseed oil, gum rosin, wood rosin, Japanese wax, paraffin, petrolatum, copper sulfate, Peru balsam, acetic acid, salicylic acid and trace amounts of Guinea green B. We report a case of contact dermatitis in a 38-year-old Japanese woman caused by TSO. The patient presented to our hospital with pruritic erythema on her left cheek. In order to remove a subcutaneous tumor, she had applied TSO 4 days prior to presentation. Clinical examination showed a well-demarcated exudative erythematous macule with yellowish crusts and scales on her left cheek. Patch testing showed a positive reaction to TSO (++), gum rosin (++) and wood rosin (++) at 72 h. As TSO includes highly allergenic material, caution should be made in applying this topical therapy. PMID:21592201

Tsuruta, Daisuke; Sowa, Junko; Tsuruta, Kyoko; Ishii, Masamitsu; Kobayashi, Hiromi

2011-10-01

398

Evaluation of oleo-gum resin as directly compressible tablet excipient and release retardant.  

PubMed

The present study was designed to study drug release retardant property of myrrh oleo-gum resin from tablets prepared by direct compression method (without binding agent). The tablets were evaluated for various physical tests viz. hardness, friability, tensile strength and drug content. Accelerated stability testing was carried out according to ICH guidelines. Batch F-VII showed 041% friability, 6 kg/cm2 hardness and 0.961 MN/m2 tensile strength. In vitro dissolution studies were performed and different empirical models were applied to drug release data for evaluating the drug release mechanisms and kinetics. A criterion for selecting the most appropriate model was based on linearity (coefficient of correlation). The in vitro release data fit well to the Hixson Crowell model (r2 value ranged from 0.9771 to 0.9945) indicating the drug release mechanism to be surface erosion, effected through water diffusion, polymer hydration, disentanglement and dissolution. In conclusion, myrrh-oleo-gum resin was found to be a suitable directly compressible tablet excipients having release modifying property. PMID:20524434

Kumar, Pradeep; Singh, Inderbir

2010-01-01

399

A comparison between shaker and bioreactor performance based on the kinetic parameters of xanthan gum production.  

PubMed

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 and to determine the kinetic parameters of this bioreaction under optimized conditions. The effects of yeast extract and ammonium nitrate concentrations for a given sucrose concentration (12.1-37.8 g L(-1)) were evaluated by central composite design to maximize the conversion efficiency. In a bioreactor, the maximum conversion efficiency was achieved using 27.0 g L(-1) sucrose, 2.7 g L(-1) yeast extract, and 0.9 g L(-1) NH(4)NO(3). This point was assayed in a shaker and in a bioreactor to compare bioreaction parameters. These parameters were estimated by the unstructured kinetic model of Weiss and Ollis (Biotechnol Bioeng 22:859-873, 1980) to determinate the yields (Y (P/S)), the maximum growth specific rate (mu (max)), and the saturation cellular concentration (X*). The parameters of the model (mu (max), X*, m, lambda, alpha, and beta) were obtained by nonlinear regression. For production of xanthan gum in a shaker, the values of mu (max) and Y (P/S) obtained were 0.119 h(-1) and 0.34 g g(-1), respectively, while in a bioreactor, they were 0.411 h(-1) and 0.63 g g(-1), respectively. PMID:19130306

Faria, S; Vieira, P A; Resende, M M; França, F P; Cardoso, V L

2009-05-01

400

The Yariv reagent: Behaviour in different solvents and interaction with a gum arabic arabinogalactanprotein.  

PubMed

The ?-d-Glc Yariv reagent is frequently used to isolate and to study the structure of arabinogalactan-proteins with the arabinogalactan type II structure. The present paper describes the aggregation features of the Yariv reagent in water, salt solutions and in organic solvents as determined by NMR, absorption spectroscopy and light scattering experiments. The results indicate that in water the Yariv reagent forms aggregates of up to 300 units and in 1% aqueous NaCl the degree of aggregation is approx. 150. The aggregates are formed both by H-bonds and hydrophobic interactions, the former appearing to be of most importance in water. The interaction between the Yariv reagent and an AGP fraction from gum arabic, showed a degree of aggregation of the Yariv reagent when using 1% NaCl to be of approx. 150 units, whereas disruption of the aggregate took place in 10% NaCl with an aggregation number of approx. 100. Partial acid hydrolysis of an AGP from gum Arabic (Acacia Senegal) and analyses of the linkage types remaining indicated that a certain length of (1?3)-?-linked galactose units was necessary for binding between the Yariv reagent and the AGP. This is in accordance to what also was recently observed by Kitazawa et al. (2013). PMID:24721102

Paulsen, B S; Craik, D J; Dunstan, D E; Stone, B A; Bacic, A

2014-06-15

401

Formation of a bioactive calcium titanate layer on gum metal by chemical treatment.  

PubMed

The so-called gum metal with the composition Ti-36Nb-2Ta-3Zr-0.3O is free from cytotoxic elements and exhibits a low elastic modulus as well as high mechanical strength. In the present study, it was shown that this alloy exhibited a high capacity for apatite formation in a simulated body fluid when subjected to 1 M NaOH treatment, 100 mM CaCl(2) treatment, heat treatment at 700°C, and then hot water treatment. The high apatite formation was attributed to the CaTi(2)O(5) which was precipitated on its surface, and found to be maintained even in a humid environment over a long period. The treated surface exhibited high scratch resistance, which is likely to be useful in clinical applications. The surface treatment had little effect on the unique mechanical properties described above. These results show that gum metal subjected to the present surface treatments exhibits a high potential for bone-bonding, which will be useful in orthopedic and dental implants. PMID:22350777

Yamaguchi, Seiji; Kizuki, Takashi; Takadama, Hiroaki; Matsushita, Tomiharu; Nakamura, Takashi; Kokubo, Tadashi

2012-04-01

402

New intrinsic mechanism on gum-like superelasticity of multifunctional alloys  

NASA Astrophysics Data System (ADS)

Ti-Nb-based Gum Metals exhibit extraordinary superelasticity with ultralow elastic modulus, superior strength and ductility, and a peculiar dislocation-free deformation behavior, most of which challenge existing theories of crystal strength. Additionally, this kind of alloys actually displays even more anomalous mechanical properties, such as the non-linear superelastic behavior, accompanied by a pronounced tension-to-compression asymmetry, and large ductility with a low Poisson's ratio. Two main contradictory arguments exist concerning the deformation mechanisms of those alloys, i.e., formation of reversible nanodisturbance and reversible martensitic transformation. Herein we used the in-situ synchrotron high-energy X-ray scattering technique to reveal the novel intrinsic physical origin of all anomalous mechanical properties of the Ti-24Nb-4Zr-8Sn-0.10O alloy, a typical gum-like metal. Our experiments provide direct evidence on two different kinds of interesting, stress-induced, reversible nanoscale martensitic transitions, i.e., the austenitic regions with B2 structure transform to ?'' martensite and those with BCC structure transform to ? martensite.

Liu, Jia-Peng; Wang, Yan-Dong; Hao, Yu-Lin; Wang, Yunzhi; Nie, Zhi-Hua; Wang, Dong; Ren, Yang; Lu, Zhao-Ping; Wang, Jinguo; Wang, Haoliang; Hui, Xidong; Lu, Ning; Kim, Moon J.; Yang, Rui

2013-07-01

403

Ultrasound-assisted formation of the canthaxanthin emulsions stabilized by arabic and xanthan gums.  

PubMed

There is interest in incorporating canthaxanthin (CTX) into food emulsions due to its high potential health benefits. The used CTX in this study was produced by the bacterium of Dietzia natronolimnaea HS-1. Then, the influence of main emulsion components (gum arabic (GA), xanthan gum (XG) and coconut oil (CO)) on the surface-weighted mean diameter (D32), polydispersity index (PDI), specific surface area (SSA) of droplets and density of the emulsions containing CTX was optimized using response surface methodology (RSM). Polynomial equations between the responses and independent variables were derived. The linear effect of GA had a significant (p<0.0001) term in all reduced models. The optimal formulation for emulsions was composed of GA content of 9.85% (w/w), XG content of 0.13% (w/w) and CO concentration of 3.50% (w/w). This optimum formulation yielded D32 of 0.752 ?m, PDI of 1.533, SSA of 9.995 m(2)/ml and density of 1.0357 g/cm(3). PMID:23688450

Gharibzahedi, Seyed Mohammad Taghi; Razavi, Seyed Hadi; Mousavi, Seyed Mohammad

2013-07-01

404

New intrinsic mechanism on gum-like superelasticity of multifunctional alloys  

PubMed Central

Ti-Nb-based Gum Metals exhibit extraordinary superelasticity with ultralow elastic modulus, superior strength and ductility, and a peculiar dislocation-free deformation behavior, most of which challenge existing theories of crystal strength. Additionally, this kind of alloys actually displays even more anomalous mechanical properties, such as the non-linear superelastic behavior, accompanied by a pronounced tension-to-compression asymmetry, and large ductility with a low Poisson's ratio. Two main contradictory arguments exist concerning the deformation mechanisms of those alloys, i.e., formation of reversible nanodisturbance and reversible martensitic transformation. Herein we used the in-situ synchrotron high-energy X-ray scattering technique to reveal the novel intrinsic physical origin of all anomalous mechanical properties of the Ti-24Nb-4Zr-8Sn-0.10O alloy, a typical gum-like metal. Our experiments provide direct evidence on two different kinds of interesting, stress-induced, reversible nanoscale martensitic transitions, i.e., the austenitic regions with B2 structure transform to ?? martensite and those with BCC structure transform to ? martensite.

Liu, Jia-Peng; Wang, Yan-Dong; Hao, Yu-Lin; Wang, Yunzhi; Nie, Zhi-Hua; Wang, Dong; Ren, Yang; Lu, Zhao-Ping; Wang, Jinguo; Wang, Haoliang; Hui, Xidong; Lu, Ning; Kim, Moon J.; Yang, Rui

2013-01-01

405

DETECTION OF WOOD DECAY IN BLUE GUM AND ELM: AN EVALUATION OF THE RESISTOGRAPH® AND THE PORTABLE DRILL  

Microsoft Academic Search

Decay and soundwood assessments made with the Resistograph® and the portable drill were compared with laboratory measurements of wood density. Sixteen Tasmanian blue gum (Eucalyptus globulus) and 5 Scotch elm (Ulmus glabra) were evaluated in the field, cut, sectioned along Resistograph and drill test paths, and measured for density. Resistograph measurements of soundwood depth agreed closely with density measurements in

Laurence R. Costello; Stephen L. Quarles

1999-01-01

406

Graft [partially carboxymethylated guar gum-g-poly N-(hydroxymethyl) acrylamide] copolymer: From synthesis to applications.  

PubMed

Graft copolymer of N-(hydroxymethyl) acrylamide with carboxymethylated guar gum was synthesized and the reaction conditions were optimized for better yield using potassium peroxymonosulfate and thiourea as a redox initiator. The optimum reaction conditions for grafting have also been determined by studying the effect of N-(hydroxymethyl) acrylamide, hydrogen ion, peroxymonosulphate, thiourea concentration and carboxymethylated guar gum along with time and temperature. Experimental results show that maximum grafting has been obtained at 1.4gdm(-3) concentration of carboxymethylated guar gum and 16×10(-2)moldm(-3) concentration of N-(hydroxymethyl) acrylamide. It has been observed that grafting ratio, add on, conversion, efficiency and rate of grafting increase up to 6.0×10(-3)moldm(-3) of hydrogen ion, 2.4×10(-3)moldm(-3) of thiourea, 14×10(-3)moldm(-3) of peroxymonosulphate and 35°C of temperature. Grafted copolymer has been characterized by FTIR spectroscopy and thermogravimetric analysis. Water swelling, flocculating, and metal ion uptake properties of partially carboxymethylated guar gum-g-N-(hydroxymethyl) acrylamide have been determined. PMID:24906757

Pandey, Vijay Shankar; Verma, Shiv Kumar; Behari, Kunj

2014-09-22

407

Identification of the Properties of Gum Arabic Used as a Binder in 7.62- mm Ammunition Primers.  

National Technical Information Service (NTIS)

A chronic sporadic problem with 7.62-mm ammunition has been hangfires. The primer, FA-956, used in the cartridge was identified as a potential source of the problem. Specifically, gum arabic, used in the binder mix is believed to be the cause because of t...

G. Chen J. Beecher M. D'Auria M. Mansfield R. Godfrey

2010-01-01

408

Gum arabic promotes rat jejunal sodium and water absorption from oral rehydration solutions in two models of diarrhea  

Microsoft Academic Search

BACKGROUND & AIMS: We have shown that addition of gum arabic (GA) to a 90 mmol\\/L sodium-111 mmol\\/L glucose oral rehydration solution (ORS) enhances its effectiveness for water and electrolyte absorption in normal rats. The present study extends these observations on GA in ORS to two rat models of diarrheal disease. METHODS: Juvenile rats were either treated for 1 week

RA Wapnir; MA Wingertzahn; J Moyse; S Teichberg

1997-01-01

409

FLAVOR ENCAPSULATION AND RELEASE CHARACTERISTICS OF SPRAY-DRIED POWDER BY THE BLENDED ENCAPSULANT OF CYCLODEXTRIN AND GUM ARABIC  

Microsoft Academic Search

The flavor inclusion powder was prepared by spray drying, using the combined encapsulation method of inclusion by ?-cyclodextrin (?-CD) and emulsified by gum arabic (GA). d-Limonene and ethyl n-hexanoate were used as model flavors. The application of high pressure by Microfluidizer to the mixture of flavors and ?-CD slurry was an effective means of forming inclusion complex. Flavor retention during

Hirokazu Shiga; Hidefumi Yoshii; Taiji Nishiyama; Takeshi Furuta; Pirkko Forssele; Kaisa Poutanen; Pekka Linko

2001-01-01

410

Effects of Ca 2+ crosslinking on structure and properties of waterborne polyurethane-carboxymethylated guar gum films  

Microsoft Academic Search

Films from waterborne polyurethane (WPU) and carboxymethylated guar gum (CMGG) with different contents (20–80wt%) were prepared through solution casting method, and then were crosslinked with calcium chloride. The effect of CMGG content on the miscibility, morphology and physical properties of the blend films is investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, density measurements, differential scanning calorimetry, dynamic mechanical

Yihong Huang; Huiqun Yu; Chaobo Xiao

2006-01-01

411

Agglomeration of a model food powder: Effect of maltodextrin and gum Arabic dispersions on flow behavior and compacted mass  

Microsoft Academic Search

The process of agglomeration of particulate foods was studied by employing corn starch as a model system. The effect of different liquid binders (maltodextrin and gum Arabic) to the extent of 1–5% was used to study the changes in the characteristics of the powder. Rheological behavior of powder was quantified in terms of textural indices like maximum force, and energy

Sudeep Ghosal; T. N. Indira; Suvendu Bhattacharya

2010-01-01

412

Learning Mastery System for "Investigating School Mathematics," Book 2. [Kit Contains Teacher's Manuals, Gummed Stickers, and Duplicator Masters].  

ERIC Educational Resources Information Center

This set of duplicator masters accompanies "Investigating School Mathematics," Book 2, as a supplement to individualize mathematics instruction. The set includes three teacher's manuals, three sets of gummed labels for file folder tabs, and duplicating masters for student record sheets, a home correspondence information letter, and a home…

Southwest Regional Laboratory for Educational Research and Development, Los Alamitos, CA.

413

Learning Mastery System for "Investigating School Mathematics," Book 3. [Kit Contains Teacher's Manuals, Gummed Stickers, and Duplicator Masters].  

ERIC Educational Resources Information Center

This set of duplicator masters accompanies "Investigating School Mathematics," Book 3 as a supplement to individualize mathematics instruction. The set includes three teacher's manuals, three sets of gummed labels for file folder tabs, and duplicating masters for student record sheets, a home correspondence information letter, and a home…

Southwest Regional Laboratory for Educational Research and Development, Los Alamitos, CA.

414

Viscous Synergism in Carrageenans (&kgr; and &lgr;) and Locust Bean Gum Mixtures: Influence of Adding Sodium Carboxymethylcellulose  

Microsoft Academic Search

Synergistic interactions between locust bean gum (LBG) and two types of carrageenans (&kgr; and &lgr;) are studied. Viscous synergism index, Iv as a function of concentration ratioz=ćLBG\\/ćcar, and shear rate were obtained for every mixture. In both binary systems the values of this index decrease with increasing shear rate. For the LBG + &kgr; mixtures, Ivpresented a maximum at a

M. J. Hernández; J. Dolz; M. Dolz; J. Delegido; J. Pellicer

2001-01-01

415

Microencapsulation of cardamom oleoresin: Evaluation of blends of gum arabic, maltodextrin and a modified starch as wall materials  

Microsoft Academic Search

Although the spice oleoresins provide complete flavour profile than their respective essential oils, their sensitivity to the light, heat and oxygen is a disadvantage. This can be overcome by effective encapsulation. The present work reports on the microencapsulation of cardamom oleoresin by spray drying using binary and ternary blends of gum arabic, maltodextrin, and modified starch as wall materials. The

Savitha Krishnan; Rajesh Bhosale; Rekha S. Singhal

2005-01-01

416

Acacia gum supplementation of a low-protein diet in children with end-stage renal disease  

Microsoft Academic Search

Patients with end-stage renal disease (ESRD) die in the absence of renal replacement therapy (RRT). In developing countries RRT is not uniformly available and treatment often relies on conservative management and intermittent peritoneal dialysis (IPD). This study investigates the possibility of using acacia gum supplementation to improve the quality of life and provide children with ESRD with a dialysis-free period.

Aamir Jalal Al-Mosawi

2004-01-01

417

Gums - swollen  

MedlinePLUS

... dentures or other dental appliances Pregnancy Sensitivity to toothpaste or mouthwash Scurvy Side effect of a drug ... such as mouthwashes, alcohol, and tobacco. Change your toothpaste brand and stop using mouthwashes if sensitivity to ...

418

Bleeding Gums  

MedlinePLUS

... Women's Checkup Pregnancy Checkup Baby Checkup Mens Checkup Stephen J. Schueler, M.D. About Stephen J. Schueler, MD How it Works Testimonials FAQ ... should you do to care for yourself? About Stephen J. Schueler, M.D News Advertising How It ...

419

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

PubMed

Oil-containing gelatin-gum Arabic microparticles were prepared by complex coacervation followed by crosslinking with glutaraldehyde or transglutaminase. A fluorescent mixture, khusimyl dansylate (KD) as the fluorescent compound mixed to the vetiver essential oil, was used as oil model. The effect of the type of crosslinking of the coacervated gelatin-gum Arabic membrane, the physical state of microparticles, wet or freeze-dried and the type of release media, aqueous with surfactants, Sodium Dodecyl Sulphate (sds) or Tween 80 (tw) and anhydrous ethanol as organic media on the release rate of the KD from the microparticles, was experimentally investigated. It was shown that the oil was dispersed uniformly throughout the microparticles and the chemical crosslinked microparticles were more resistant to swelling, presenting smaller sizes after hydration. Also the crosslinking effect, transglutaminase or glutaraldehyde, could be confirmed by the integrity of the crosslinked gelatin-gum Arabic microparticles after incubation in the aqueous sds media, compared to complete dissolution of the uncrosslinked microparticles in this media. The cumulative fluorescent KD release from the gelatin-gum Arabic microparticles decreased in the following order of dissolution media: anhydrous ethanol>tw>sds and the wet microparticles have shown a faster KD release than freeze-dried ones. A mathematical model was used to estimate the diffusion coefficient (D). The chemically crosslinked gelatin-gum Arabic microparticles ensured a pronounced retard effect in the KD diffusion, presenting a D varying from 0.02 to 0.6 x 10(-11)cm(2)/s, mainly in an aqueous media, against D varying from 1.05 to 13.9 x 10(-11)cm(2)/s from the enzymatic crosslinked microparticles. PMID:18835139

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

2008-12-01

420

Discovering young stars in the Gum 31 region with infrared observations  

NASA Astrophysics Data System (ADS)

Context. The Gum 31 bubble, which contains the stellar cluster NGC 3324, is a poorly studied young region close to the Carina Nebula. Aims: We are aiming to characterise the young stellar and protostellar population in and around Gum 31 and to investigate the star-formation process in this region. Methods: We identified candidate young stellar objects from Spitzer, WISE, and Herschel data. Combining these, we analysed the spectral energy distributions of the candidate young stellar objects. With density and temperature maps obtained from Herschel data and comparisons to a collect-and-collapse scenario for the region we are able to further constrain the characteristics of the region as a whole. Results: We find 661 candidate young stellar objects from WISE data; 91 protostar candidates are detected through Herschel observations in a 1.0° × 1.1° area. Most of these objects are found in small clusters or are well aligned with the H II bubble. We also identify the sources of Herbig-Haro jets. The infrared morphology of the region suggests that it is part of the larger Carina Nebula complex. Conclusions: The location of the candidate young stellar objects on the rim of the H II bubble is suggestive of their being triggered according to a collect-and-collapse scenario, which agrees well with the observed parameters of the region. Some candidate young stellar objects are found in the heads of pillars, which indicates radiative triggering of star formation. All in all, we find evidence that in the region different mechanisms of triggered star formation are at work. Correcting the number of candidate young stellar objects for contamination, we find ~600 young stellar objects in Gum 31 above our completeness limit of about 1 M?. Extrapolating the initial mass function down to 0.1 M?, we estimate a total population of ~5000 young stars for the region. This work is based in part on data collected by Herschel, an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA, and on data observed by VISTA (ESO run number 088.C-0117(A)), an ESO survey telescope developed by a consortium of 18 universities in the United Kingdom, led by Queen Mary, University of London.Tables 1-3 are available in electronic form at http://www.aanda.org

Ohlendorf, H.; Preibisch, T.; Gaczkowski, B.; Ratzka, T.; Ngoumou, J.; Roccatagliata, V.; Grellmann, R.

2013-04-01

421

Ideal tensile and shear strength of a gum metal approximant: Ab initio density functional calculations  

NASA Astrophysics Data System (ADS)

The ideal tensile and shear strengths of binary ?-phase Ti3Nb alloys have been investigated using ab initio density functional calculations. The binary alloy is considered as an approximant to the multifunctional Ti-Nb-Ta-Zr-O alloy known as “gum metal,” which displays high strength, low elastic modulus, high yield strain, and very good ductility. This alloy has been reported to deform elastically until the stress approaches the ideal tensile strength. Our calculations have been performed for an optimized chemical decoration of the body-centered cubic (bcc) structure of the ? phase. Previous work has demonstrated that this model yields elastic constants in very good agreement with those measured for gum metal specimens and leads to a reasonably accurate description of the martensitic transformations between the bcc ?, the orthorhombic ?'' and the hexagonal ? phases [Lazar , Phys. Rev. BPLRBAQ0556-280510.1103/PhysRevB.84.054202 84, 054202 (2011)]. The simulations of the response to tensile and shear loading have been performed for large supercells which account also for the different orientations of the -Nb-Nb- chains characteristic for the ?-phase structure relative to the direction of the applied load. The energy-strain and stress-strain curves are found to be very different from those reported for all bcc metals. Under uniaxial <100> loading we find an ideal tensile strength of 2.4 GPa, the upper limit to the tensile stress arising from a shear instability of the structure. Under uniaxial <110> load we calculate an ideal tensile strength of 2.2 or 2.8 GPa, depending on the orientation of the -Nb-Nb- chains relative to the loading direction. For a realistic multidomain structure the ideal strength is expected to correspond to the average of these values. An ideal strength of 2.6 GPa under <110> loading is roughly the same as under <100> load, despite a considerable anisotropy of the tensile moduli. For {211}<111> shear we calculate an ideal shear strength of 1.6 GPa, again as an average over different possible shearing directions relative to the Nb-Nb bonds. For the {110}<110> shear system we find a lower strength of 0.9 GPa. The structures reached at the stress maximum under <100> uniaxial tension and {211}<111> shear are identical, and since the maximal shear stress is much lower than the tensile stress, the alloy will fail by shear even under strictly uniaxial tension. The values of the ideal tensile and shear strengths are significantly low, even in comparison with those calculated for bcc V and Nb with very small shear moduli and approach the values reported for gum metal alloys.

Nagasako, Naoyuki; Asahi, Ryoji; Hafner, Jürgen

2012-01-01

422

Lepidium perfoliatum seed gum: a new source of carbohydrate to make a biodegradable film.  

PubMed

Microstructural, physical, mechanical and thermal properties of a novel biodegradable film based on Lepidium perfoliatum seed gum (LPSG) were investigated. LPSG films were successfully prepared by incorporation of four levels of glycerol (40%, 50%, 60% and 70%, w/w). As expected, increasing glycerol concentration from 40 to 70% (w/w), increased water vapor permeability (WVP), elongation at break (EB%), moisture content, moisture adsorption and water solubility of LPSG films; whilst, elastic modulus (EM), contact angle, melting point (Tm), enthalpy of melting (?Hm) and glass transition point (Tg) decreased significantly. LPSG films became slightly greenish and yellowish in color but still transparent in appearance. The images taken from electron scanning microscopy indicated uniform surface, compact sheets with no holes or fracture. This study demonstrates that LPSG based films with desired properties can be obtained by adjusting glycerol content. PMID:24299783

Seyedi, Samira; Koocheki, Arash; Mohebbi, Mohebbat; Zahedi, Younes

2014-01-30

423

Biopharmaceutical evaluation of diclofenac sodium controlled release tablets prepared from gum karaya--chitosan polyelectrolyte complexes.  

PubMed

The phenomena of polymer interactions and formation of polyelectrolyte complexes (PECs) of oppositely charged polymers have been the focus of interest in fundamental and applied research. Such PECs may possess unique properties that are different from those of individual polymers. In the present study, attempts were made to prepare PECs of negative colloid gum karaya (GK) and positively charged polysaccharide chitosan (CH). The association and factors affecting the interactions between GK and CH were studied by pH and conductivity studies. The dried complexes were characterized by X-ray diffraction, Fourier transformed Infrared (FTIR) Spectroscopy, Scanning Electron Microscopy. The PECs were utilized for encapsulation of diclofenac sodium. Selected polyelectrolyte microparticles were compressed into tablets and were compared with commercial sustained release product Voveran SR®. Positive results of the study indicated the applicability of PECs in the design of oral controlled release drug delivery systems. PMID:22087874

Lankalapalli, Srinivas; Kolapalli, Ramana Murthy

2012-07-01

424

Ex Vivo Evaluation of Insulin Nanoparticles Using Chitosan and Arabic Gum  

PubMed Central

Polymeric delivery systems based on nanoparticles have emerged as a promising approach for peroral insulin delivery. The aim of the present study was to investigate the release of insulin nanoparticulate systems and ex vivo studies. The nanoparticles were prepared by the ion gelation method. Particle size distribution, zeta potential, and polydispersity index of the nanoparticles were determined. It was found that the nanoparticles carried positive charges and showed a size distribution in the range of 170–200?nm. The electrostatic interactions between the positively charged group of chitosan and negatively charged groups of Arabic gum play an important role in the association efficiency of insulin in nanoparticles. In vitro insulin release studies showed an initial burst followed by a slow release of insulin. The mucoadhesion of the nanosystem was evaluated using excised rat jejunum. Ex vivo studies have shown a significant increase in absorption of insulin in the presence of chitosan nanoparticles in comparison with free insulin.

Avadi, M. R.; Sadeghi, A. M. M.; Mohamadpour Dounighi, Naser; Dinarvand, R.; Atyabi, F.; Rafiee-Tehrani, M.

2011-01-01

425

Effect of ionic crosslink on the release of metronidazole from partially carboxymethylated guar gum tablet.  

PubMed

Partially carboxymethylated guar gum (PCMGG) was crosslinked in situ by Ca(2+) ions during wet massing step of tablet preparation. The resulting tablets were evaluated for the effect of the extent of crosslinking on drug release and matrix swelling. Increase in the concentration of Ca(2+) ions increased the viscosity of gel layer and reduced the water penetration velocity into the matrix with subsequent decrease in swelling of the tablets and drug release. Beyond a certain concentration of Ca(2+) ions, the viscosity of the gel layer decreased and the drug release rate increased primarily due to erosion of the matrix. The mechanism of drug release appeared to be non-Fickian or anomalous transport. The release data also best fitted in zero order equation. The model drug, metronidazole, was compatible with the matrix materials as evident from instrumental analyses. Such formulation may provide flexibility in achieving the desired drug release rate from crosslinked matrix tablets. PMID:24721097

Singh, Rakesh; Maity, Siddhartha; Sa, Biswanath

2014-06-15

426

Physicochemical and thermomechanical characterization of tara gum edible films: Effect of polyols as plasticizers.  

PubMed

The aim of this study was to evaluate tara gum as edible film material as well as the influence of polyols as plasticizers on the properties of the films. Thermomechanical, physicochemical and barrier properties were determined as a function of plasticizer type and concentration. Glycerol, sorbitol and PEG 400 were used in the range of 0.075-0.3g/tarag. Glycerol was the best plasticizer in terms of mechanical properties with the highest elongation (16-44%) and resistance (45-90MPa). Sorbitol presented the best barrier properties with the lowest hydrophilicity and water vapour permeability (0.24-0.34gmmm(-2)h(-1)kPa(-1)). Fourier transform infrared (FTIR) spectroscopy showed no significant effect on the structure of the polysaccharide. Dynamic mechanical analysis (DMA) revealed that incorporation of plasticizers increased the mobility of the polymer chains and reduced the glass transition and melting temperature by 30 and 100°C respectively. PMID:25037362

Antoniou, John; Liu, Fei; Majeed, Hamid; Qazi, Haroon Jamshaid; Zhong, Fang

2014-10-13

427

Uniquely different PVA-xanthan gum irradiated membranes as transdermal diltiazem delivery device.  

PubMed

This paper reports interesting differences between physical and mechanical properties of various membranes prepared from high and low molecular weight poly (vinyl alcohol) (PVA) and xanthan gum (XG) blends irradiated under low dose electron beam. The membranes were designed for sustained delivery of diltiazem hydrochloride through skin. Electron beam irradiation produced crosslinks and turned PVA into crystalline phase from its amorphous organization in the unirradiated state. PVA crystals were fibrillar at low XG content (1 wt.%) when the molecular weight was high while similar orientation at higher XG content (5 wt.%) when the molecular weight was low. Low molecular weight PVA-XG membranes showed equivalent physical properties under dry condition but wet-mechanical properties were superior for high molecular weight PVA-XG hybrids. Both of them showed slow and sustained diltiazem release but the later induced slightly slower release despite low drug encapsulation efficiency due to its better wet mechanical strength. PMID:23618267

Bhunia, Tridib; Giri, Arindam; Nasim, Tanbir; Chattopadhyay, Dipankar; Bandyopadhyay, Abhijit

2013-06-01

428

Vapor phase cracking of prompt tars from pyrolysis of sweet gum hardwood  

SciTech Connect

The vapor phase cracking of tar freshly generated by pyrolysis of sweet gum hardwood was studied as a function of temperature (500-800/sup 0/C) at residence times of 0.9 - 2.2 sec to obtain quantitative yields and kinetics. For residence times of about 1 sec, tar conversion ranged from 10 wt% at 500/sup 0/C to 32 wt% at 600/sup 0/C and reached 85 wt% at 800/sup 0/C. The major products of tar cracking are carbon monoxide, hydrogen, carbon dioxide, methane, and ethylene. Kinetic parameters obtained by fitting first-order reaction models to the data allow extents of tar cracking and resulting gaseous product yields to be predicted with an error generally less than ten percent.

Boroson, M.L.; Howard, J.B.; Longwell, J.P.; Peters, W.A.

1986-01-01

429

The influence of metabolic network structures and energy requirements on xanthan gum yields.  

PubMed

The metabolic network of Xanthomonas campestris is complex since a number of cyclic pathways are present making simple stoichiometric yield predictions difficult. The influence of certain pathway configurations and the resulting variations in flux have been examined as regards the maximum yield potential of this bacteria for xanthan gum production. These predictions have been compared with experimental results showing that the strain employed is functioning close to its theoretical maximum as regards yield criteria. The major constraint imposed on the network concerns energy availability which has a more pronounced effect on yield than carbon precursor supply. This can be attributed to the relatively high maintenance requirements determined experimentally and incorporated into the model. While some of this overall energy burden will undoubtedly be associated with incompressible metabolic requirements such as sugar uptake and xanthan efflux mechanisms, future strain improvement strategies will need to attack other non-essential energy-consuming reactions, if yields are to be further increased. PMID:12385717

Letisse, Fabien; Chevallereau, Paule; Simon, Jean-Luc; Lindley, Nic

2002-11-13

430

Toxicity studies in mice of Commiphora molmol oleo-gum-resin.  

PubMed

Acute (24 h) and chronic (90 days) oral toxicity studies on Commiphora molmol (oleo-gum-resin) were carried out in mice. Dosages in acute study were 0.5, 1.0 and 3 g/kg, while in chronic study dosage was 100 mg/kg per day. All external morphological, biochemical and haematological changes, in addition to body and vital organ weights were recorded. There was no significant difference in mortality in acute or chronic treatment as compared to controls. At the end of the treatment, weight gain in the treated as well as control group was significant. There was a significant increase in weight of testes, caudae epididymides and seminal vesicles in C. molmol treated group. Biochemical studies revealed no differences in C. molmol treated animals, however, haematological studies revealed a significant increase in RBC and haemoglobin levels as compared to the control group. C. molmol failed to show any spermatotoxic effects. PMID:11390128

Rao, R M; Khan, Z A; Shah, A H

2001-07-01

431

Phase separation induced molecular fractionation of gum arabic--sugar beet pectin systems.  

PubMed

This paper investigates the phase separation and phase separation-induced fractionation of gum arabic (GA)/sugar beet pectin (SBP) mixed solutions. A phase diagram, including cloud and binodal curves, was established by visual observation and phase composition analysis. The deviation of the binodal curve from the cloud curve was a result of phase separation-induced fractionation of polydisperse GA and SBP molecules. Fractionation of GA increased the content of arabinogalactan-protein complex (AGP) from ca. 13% to 27%. The fractionated GA (FGA) showed improved emulsifying functionality, whereas the fractionated SBP (FSBP) had a reduced emulsifying functionality. The changes in emulsifying efficiency can be explained by interfacial adsorption behaviors at the oil-water interface as indicated by interfacial tension measurements. PMID:23987401

Mao, Peng; Zhao, Meng; Zhang, Fan; Fang, Yapeng; Phillips, Glyn O; Nishinari, Katsuyoshi; Jiang, Fatang

2013-10-15

432

Thermal behavior and gelling interactions of Mesona Blumes gum and rice starch mixture.  

PubMed

In this research, thermal behavior and gelling interactions of Mesona Blumes gum (MBG)/rice starch mixture were extensively investigated. MBG/rice starch gel displayed significant endothermal and exothermal properties at different MBG concentrations, indicating essential interactions between MBG and rice starch. In addition, the gelling interaction between MBG and rice starch was studied by using hydrogen-bond forming agents (1,4-butanediol, ethane-1,2-diol, glycerol) and hydrogen-bond breaking agents (urea, tetramethyl urea, ethanol, methanol) on rheological spectra. The results indicated that the hydrogen bond between MBG, rice starch and water might be the major force of maintaining the complete structure of the mixed gel. Their hypothetic interactions have been schemed in computer using hyperchem 8.0. PMID:24751091

Feng, Tao; Ye, Ran; Zhuang, Haining; Fang, Zhongxiang; Chen, Hanqing

2012-09-01

433

Guar gum and scleroglucan interactions with borax: experimental and theoretical studies of an unexpected similarity.  

PubMed

Guar gum is a galactomannan that assumes a very flexible conformation in solution, while Scleroglucan is a very rigid polysaccharide that dissolves in water as triple helices. Both polymers can form gels in the presence of borax. Despite their structural differences, the freeze-dried gel systems of both polymers, when compressed to form tablets, show a peculiar anisotropic swelling in water that reflects an amazing similarity in terms of their molecular properies. In this paper the behavior of the Guar/borax gel is compared with that of Scleroglucan/borax. The macroscopic properties of the two systems were characterized in terms of rheological measurements. Atomic force microscopy images and molecular dynamics simulation allowed to evaluate, at molecular level, the effect of borax addition to the Guar polymer. Both experiments show that an increasing of the polymer rigidity is produced by borax. The role played by galactose in the side chain was also discussed. PMID:20863102

Bocchinfuso, Gianfranco; Mazzuca, Claudia; Sandolo, Chiara; Margheritelli, Silvia; Alhaique, Franco; Coviello, Tommasina; Palleschi, Antonio

2010-10-21

434

Preparation and characterization of guar gum hydrogels as carrier materials for controlled protein drug delivery.  

PubMed

Hydrogels were prepared from guar gum (GG) via esterification with 1,2,3,4-butanetetracarboxylic dianhydride (BTCA). Detailed spectroscopic analysis using FTIR and solid-state NMR revealed that an increase in the BTCA feed amount in the preparation mixture led to an increased degree of crosslinking, which affected the swelling behavior and rheological properties of the hydrogels. The hydrogels exhibited enzyme degradability, and after incubation with ?-mannanase and ?-galactosidase, 30-57% of the hydrogels were degraded. In addition, the hydrogels adsorbed bovine serum albumin and hen egg white lysozyme thorough electrostatic and hydrophobic interactions. The protein-adsorbed GG hydrogels exhibited a slow and steady release of the proteins over a 24h period in buffer solutions after a fast release of proteins in the first hour. As such, GG hydrogels are expected to be efficient drug delivery carriers for protein-based drugs. PMID:25037422

Kono, Hiroyuki; Otaka, Fumihiro; Ozaki, Masato

2014-10-13

435

Preparation and properties of organic-inorganic composite superabsorbent based on xanthan gum and loess.  

PubMed

A new, low-cost, and eco-friendly organic-inorganic composite superabsorbent was successfully synthesized in aqueous solution by polymerization xanthan gum (XG), neutralized acrylic acid (AA) and loess using ammonium persulfate (APS) as initiator and N,N-methylenebisacrylamide (MBA) as crosslinker. Structure and morphological characterizations of the composite superabsorbent were investigated by Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The loess content, pH values, surfactants, salts and temperature which could affect the swelling and water-retention capabilities of the composite superabsorbent were investigated. The composite superabsorbent exhibits excellent water absorbency (610g/g in distilled water), pH-stability (pH 5-10), and higher swelling capacity in anionic surfactant solution; on the other hand, the composite superabsorbent can be used for removing multivalent metal ions. PMID:25037376

Feng, Enke; Ma, Guofu; Wu, Yajuan; Wang, Haiping; Lei, Ziqiang

2014-10-13

436

Tests for mutagenic effects of ammoniated glycyrrhizin, butylated hydroxytoluene, and gum arabic in roden germ cells  

SciTech Connect

Ammoniated glycyrrhizin, butylated hydroxytoluene, and gum Arabic are generally recognized as safe (GRAS) substances that are used primarily as additives in foods. These substances were incorporated into rodent diets and fed to male rats and mice for 10 and 8 wk, respectively. The treated male mice and rats were then tested for dominant lethal effects. The mice were also tested for induced heritable translocation. Results of the rat studies indicated a statistically significant dominant lethal effect of each of the compounds tested; however, the biological significance of this response is not known. Results of the mouse dominant lethal and heritable translocation studies, on the other hand, indicated no adverse effects of the compounds tested.

Sheu, C.W.; Cain, K.T.; Rushbrook, C.J.; Jorgenson, T.A.; Generoso, W.M.

1986-01-01

437

Polyelectrolytic aqueous guar gum for adsorptive separation of soluble Pb(II) from contaminated water.  

PubMed

The article introduces the concept of homophase adsorption of soluble Pb(II) from contaminated water using aqueous guar gum (GG). The process appears to be extremely handy since it avoids hectic sample preparation and adsorbent recovery stages. The results show that, addition of only 1000ppm GG removes 56.72% of the contaminated Pb(II) within 150min at 303K. The best working pH has been found to be at 4.5. At this point GG molecules show greatest balance between negative zeta potential and high molecular size. Mechanistically, the adsorption follows Langmuir model since on formation of a monolayer, the positive Pb(II) prevent subsequent adsorption through strong electrostatic repulsion. The adsorption kinetics follows pseudo second order model. Both kinetics and thermodynamics of the process complies with the conventional hetero facial adsorption models despite huge procedural differences. PMID:24906750

Pal, Abhijit; Nasim, Tanbir; Giri, Arindam; Bandyopadhyay, Abhijit

2014-09-22

438

Processing of waxy starch/xanthan gum mixtures within the gelatinization temperature range.  

PubMed

Pasting experiments of waxy potato and waxy maize starch systems were set up in which temperatures close to the gelatinization temperature were selected (67.5, 70 and 72.5°C). DSC measurements showed that under these conditions small fractions of the starches remained ungelatinized. During the pasting process two different shear rates were imposed (50s(-1) and 150s(-1)) to investigate the shear stability of the different starch containing systems. Swelling of the granules occurred in a more controlled manner and granule breakdown during pasting could be limited. As a result of these heating conditions more swollen granules are present, as confirmed by laser light diffraction. This positive effect was clearly noticeable in the flow curves of the cooled pastes. Xanthan gum addition could further reduce breakdown either by restricting the swelling or by stabilizing the granules. At higher starch contents the former is most likely dominating. PMID:23768601

Heyman, Bart; Depypere, Frédéric; Van der Meeren, Paul; Dewettinck, Koen

2013-07-25

439

Formulation and in vitro evaluation of xanthan gum-based bilayered mucoadhesive buccal patches of zolmitriptan.  

PubMed

A novel bilayered mucoadhesive buccal patch of zolmitriptan was prepared using xanthan gum (XG) as mucoadhesive polymer. Hydroxypropyl methylcellulose E-15 was used as film-former and polyvinyl alcohol (PVA) was incorporated, to increase the tensile strength of the patches. To study the effect of independent variables viz. concentrations of XG and PVA, on various dependent variables like in vitro drug release, ex vivo mucoadhesive strength and swelling index, 3(2) factorial design was employed. In vitro drug release studies of optimized formulation showed initially, rapid drug release; 43.15% within 15 min, followed by sustained release profile over 5h. Incorporation of 4% dimethyl sulfoxide enhanced drug permeability by 3.29 folds, transported 29.10% of drug after 5h and showed no buccal mucosal damage after histopathological studies. In conclusion, XG can be used as a potential drug release modifier and mucoadhesive polymer for successful formulation of zolmitriptan buccal patches. PMID:24299896

Shiledar, Rewathi R; Tagalpallewar, Amol A; Kokare, Chandrakant R

2014-01-30

440

Microencapsulation of purple Brazilian cherry juice in xanthan, tara gums and xanthan-tara hydrogel matrixes.  

PubMed

The purple Brazilian cherry (Eugenia uniflora L.) juice was encapsulated in xanthan, tara and xanthan-tara hydrogel matrixes. Encapsulation efficiency, Differential Scanning Calorimetry (DSC), X-ray diffractometry, release profile, stability of carotenoids, phenolic compounds and antioxidant activity of microparticles were evaluated. Encapsulation was confirmed. The highest encapsulation efficiency was obtained with xanthan gum and hydrogel was mostly indicated for the release of carotenoids in GFS and IFS medium. Phenolic compounds had the highest release rate but not in a gradually way, regardless of wall material and fluids under analysis. Stored microparticles at 4 and 25 °C, showed carotenoid degradation. Xanthan and hydrogel wall material provided the greatest stability to these compounds. The microparticles' anti-oxidant activity decreased during storage due to the degradation of carotenoids. PMID:24053801

Rutz, Josiane K; Zambiazi, Rui C; Borges, Caroline D; Krumreich, Fernanda D; da Luz, Suzane R; Hartwig, Naralice; da Rosa, Cleonice G

2013-11-01

441

Mineralization of hydroxyapatite upon a unique xanthan gum hydrogel by an alternate soaking process.  

PubMed

We previously reported a xanthan gum (Xan) hydrogel showing excellent mechanical properties. Mineralization of hydroxyapatite (Hap) upon the Xan hydrogel would provide a unique biomaterial applicable for bone tissue engineering. Here, we show the mineralization of Hap upon the Xan hydrogel by means of an alternate soaking process. Hap was gradually grown upon the Xan-matrix surface with increasing number of soaking cycles due to the ionic interactions between calcium cations and carboxyl groups. Interestingly, the mineralization induced a microstructure change in the gel-matrix from a layered structure to a porous structure. The mechanical properties of the resulting Hap-Xan composite hydrogels were further investigated by a tensile test, where the Hap-Xan composite hydrogel with an appropriate amount of Hap (Xan/Hap=2.7) was capable of approximately 370% elongation. PMID:24507355

Izawa, Hironori; Nishino, Shoji; Maeda, Hiroyuki; Morita, Kohei; Ifuku, Shinsuke; Morimoto, Minoru; Saimoto, Hiroyuki; Kadokawa, Jun-ichi

2014-02-15

442

Method of inhibiting crosslinking of aqueous xanthan gums in the presence of ferric acid ions  

SciTech Connect

The cross linking of aqueous xanthan gums in the presence of ferric ions is inhibited or prevented by adding a soluble alkanoic and/or alkenoic acid having at least 4 carbon atoms and bearing at least 2 hydroxyl groups per molecule, and/or a soluble salt of ..gamma..-lactone. This combination of ingredients forms gelled acid compositions which are useful in acidizing treatments of wells. The gelled acid compositions are viscous fluids which have increased stability against shear and thermal degradation and other properties which result in retarded reaction rates and reduced fluid leak-off during acidizing treatments of subterranean formations surrounding well bores. The aqueous gelled acids have the further advantage of inhibiting or preventing the formation of insoluble compounds, such as ferric hydroxide, during such acidizing treatments. 13 claims.

Crowe, C.W.

1982-03-02

443

Evaluation of honey locust (Gleditsia triacanthos Linn.) gum as sustaining material in tablet dosage forms.  

PubMed

In this study, honey locust gum (HLG) obtained from Gleditsia triacanthos (honey locust) beans was investigated as a hydrophilic matrix material in the tablets prepared at different concentrations (5% and 10%) by wet granulation method. Theophylline was chosen as a model drug. The matrix tablets containing hydroxyethylcellulose and hydroxypropyl methylcellulose as sustaining polymers at the same concentrations were prepared and a commercial sustained release (CSR) tablet containing 200 mg theophylline was examined for comparison of HLG performance. Physical analysis on CSR tablet, matrix tablets and their granules before compression were performed. According to the results obtained from dissolution studies in distilled water, pH 1.2 HCl buffer and pH 7.2 phosphate buffer, no significant difference was found between CSR tablet and the matrix tablet containing 10% HLG in each medium (P > 0.05) and these tablets showed zero-order kinetic model in all the mediums. PMID:15231434

Uner, Melike; Altinkurt, Turan

2004-07-01

444

Morphology and metal binding characteristics of a natural polymer-kondagogu (Cochlospermum gossypium) gum.  

PubMed

Kondagogu (Cochlospermum gossypium) gum (KG), a natural tree exudate, was investigated for its morphological, adsorption and metal interaction behavior with various toxic heavy metals (Pb, Cd, Ni, Cr and Fe). SEM, AFM and TEM techniques were used to study the morphological changes occurring after metal adsorption onto the biopolymer structure. The degree of biosorption of metals on KG biopolymer surfaces was assessed by small-angle X-ray scattering analysis. EDXA spectrum revealed that the ion-exchange mechanism plays a major role in the binding process between KG and metal ions. The higher electron density observed in the KG-Cd complex suggests that Cd is strongly bound to KG compared to the other metals. This work provides a potential platform for developing a hydrocolloid-based nanogel for bioremediation of environmental contaminants. PMID:23860274

Vinod, V T P; Sashidhar, R B; ?erník, Miroslav

2013-01-01

445

Crystallization and Preliminary Crystallographic Characterization of GumK, A Membrane-Associated Gluocuronosyltransferase from Xanthomonas campestris Required for Xanthan Polysaccharide Synthesis  

SciTech Connect

GumK is a membrane-associated inverting glucuronosyltransferase that is part of the biosynthetic route of xanthan, an industrially important exopolysaccharide produced by Xanthomonas campestris. The enzyme catalyzes the fourth glycosylation step in the pentasaccharide-P-P-polyisoprenyl assembly, an oligosaccharide diphosphate lipid intermediate in xanthan biosynthesis. GumK has marginal homology to other glycosyltransferases (GTs). It belongs to the CAZy family GT 70, for which no structure is currently available, and indirect biochemical evidence suggests that it also belongs to the GT-B structural superfamily. Crystals of recombinant GumK from X. campestris have been grown that diffract to 1.9 {angstrom} resolution. Knowledge of the crystal structure of GumK will help in understanding xanthan biosynthesis and its regulation and will also allow a subsequent rational approach to enzyme design and engineering. The multiwavelength anomalous diffraction approach will be used to solve the phase problem.

Barreras,M.; Bianchet, M.; Ielpi, L.; Tong, L.

2006-01-01