Gum Disease

Science.gov (United States)

... and gums isn't removed by good daily dental care, over time it will harden into a crust called calculus or tartar . Once tartar forms, it starts to destroy gum tissue, causing gums to bleed and pull away from the teeth. This is known as periodontitis (pronounced: pair-ee- ...

PLA/PBAT Bionanocomposites with Antimicrobial Natural Rosin for Green Packaging.

Science.gov (United States)

Moustafa, Hesham; El Kissi, Nadia; Abou-Kandil, Ahmed I; Abdel-Aziz, Mohamed S; Dufresne, Alain

2017-06-14

The use of biodegradable polymers is of great importance nowadays in many applications. Some of the most commonly used biopolymers are polylactic acid (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) due to their superior properties and availability. In this manuscript, we use a facile and green modification method of organoclay (OC) by antimicrobial natural rosin which is considered as a toxicity-free reinforcing material, thus keeping the green character of the material. It increases the interlayer spacing between the clay platelets. This was proven by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) and found to impart antimicrobial properties to PLA/PBAT blends. The morphology of the resulting blends was conducted using scanning and transmission electron microscopies (SEM and TEM), and evidence of exfoliation and intercalation was observed. The thermal properties of the blends were studied using differential scanning calorimetry (DSC), and a detailed study of the crystallization of both PLA and PBAT was reported showing cold crystallization behavior of PLA. The final effect on mechanical and antimicrobial properties was also investigated. The obtained results reveal excellent possibility of using expanded OC modified PLA/PBAT polymer blends by adding a green material, antimicrobial natural rosin, for food packaging and biomembranes applications.

The effect of gamma irradiation on guar gum, locust bean gum, gum tragacanth and gum karaya

International Nuclear Information System (INIS)

King, Karen; Gray, Richard

1993-01-01

Changes in rheological properties, as measured by viscosity, of two galactomannans (guar gum and locust beam gum) and two acidic polysaccharides (gumtragacanth and gum karaya) were studied at a range of irradiation doses o C for 1 h was determined over a wide shear rate range. All samples showed pseudoplastic behaviour which approached Newtonian with increasing irradiation dose. Viscosities were calculated at a shear rate of 54 sec -1 to enable comparison across the samples. Both galactomannans showed a decrease in viscosity with increasing γ irradiation independent of temperature and a hypothesis is proposed that at low γ irradiation doses (<2 kGy) there is a reduction in polymer aggregation in solution, whereas at higher doses polymer hydrolysis occurs. Electron spin resonance spectroscopy data supports this hypothesis, with the detection of different free radicals at low and high irradiation doses. The viscosity of the acidic polysaccharides, gum karaya and gum tragacanth, following γ irradiation at low doses (<1 kGy) was unchanged or slightly higher when compared to the unirradiated control samples. Above 1 kGy dispersion viscosity decreased with increasing dose. For these polysaccharides chain hydrolysis seems to occur during irradiation at all doses resulting in an increase in the amount of soluble polymer and hence increased viscosity at low doses, whilst at high doses viscosity decreases due to extensive polymer hydrolysis. Similar electron spin resonance (ESR) spectra were obtained at low and high doses with a stronger signal at the higher dose. (Author)

Immune reactivities against gums.

Science.gov (United States)

Vojdani, Aristo; Vojdani, Charlene

2015-01-01

Different kinds of gums from various sources enjoy an extremely broad range of commercial and industrial use, from food and pharmaceuticals to printing and adhesives. Although generally recognized as safe by the US Food and Drug Administration (FDA), gums have a history of association with sensitive or allergic reactions. In addition, studies have shown that gums have a structural, molecular similarity to a number of common foods. A possibility exists for cross-reactivity. Due to the widespread use of gums in almost every aspect of modern life, the overall goal of the current investigation was to determine the degree of immune reactivity to various gum antigens in the sera of individuals representing the general population. The study was a randomized, controlled trial. 288 sera purchased from a commercial source. The sera was screened for immunoglobulin G (IgG) and immunoglobulin E (IgE) antibodies against extracts of mastic gum, carrageenan, xantham gum, guar gum, gum tragacanth, locust bean gum, and β-glucan, using indirect enzyme-linked immunosorbent assay (ELISA) testing. For each gum antigen, inhibition testing was performed on the 4 sera that showed the highest IgG and IgE immune reactivity against the different gums used in the study. Inhibition testing on these same sera for sesame albumin, lentil, corn, rice, pineapple, peanut, pea protein, shrimp, or kidney bean was used to determine the cross-reactivity of these foods with the gum. Of the 288 samples, 4.2%-27% of the specimens showed a significant elevation in IgG antibodies against various gums. Only 4 of 288, or 1.4%, showed a simultaneous elevation of the IgG antibody against all 7 gum extracts. For the IgE antibody, 15.6%-29.1% of the specimens showed an elevation against the various gums. A significant percentage of the specimens, 12.8%, simultaneously produced IgE antibodies against all 7 tested extracts. Overall, the percentage of elevation in IgE antibodies against different gum extracts, with

Gummed-up memory: chewing gum impairs short-term recall.

Science.gov (United States)

Kozlov, Michail D; Hughes, Robert W; Jones, Dylan M

2012-01-01

Several studies have suggested that short-term memory is generally improved by chewing gum. However, we report the first studies to show that chewing gum impairs short-term memory for both item order and item identity. Experiment 1 showed that chewing gum reduces serial recall of letter lists. Experiment 2 indicated that chewing does not simply disrupt vocal-articulatory planning required for order retention: Chewing equally impairs a matched task that required retention of list item identity. Experiment 3 demonstrated that manual tapping produces a similar pattern of impairment to that of chewing gum. These results clearly qualify the assertion that chewing gum improves short-term memory. They also pose a problem for short-term memory theories asserting that forgetting is based on domain-specific interference given that chewing does not interfere with verbal memory any more than tapping. It is suggested that tapping and chewing reduce the general capacity to process sequences.

The effect of gamma irradiation on guar gum, locust bean gum, gum tragacanth and gum karaya

Energy Technology Data Exchange (ETDEWEB)

King, Karen (Department of Agriculture for Northern Ireland, Belfast (United Kingdom) Queen' s Univ., Belfast, Northern Ireland (United Kingdom)); Gray, Richard (Department of Agriculture for Northern Ireland, Belfast (United Kingdom))

1993-02-01

Changes in rheological properties, as measured by viscosity, of two galactomannans (guar gum and locust beam gum) and two acidic polysaccharides (gumtragacanth and gum karaya) were studied at a range of irradiation doses < 10 kGy. Powdered samples were irradiated, and the viscosity of a 1% dispersion prepared at room temperature or by heating to 80[sup o]C for 1 h was determined over a wide shear rate range. All samples showed pseudoplastic behaviour which approached Newtonian with increasing irradiation dose. Viscosities were calculated at a shear rate of 54 sec[sup -1] to enable comparison across the samples. Both galactomannans showed a decrease in viscosity with increasing [gamma] irradiation independent of temperature and a hypothesis is proposed that at low [gamma] irradiation doses (<2 kGy) there is a reduction in polymer aggregation in solution, whereas at higher doses polymer hydrolysis occurs. Electron spin resonance spectroscopy data supports this hypothesis, with the detection of different free radicals at low and high irradiation doses. The viscosity of the acidic polysaccharides, gum karaya and gum tragacanth, following [gamma] irradiation at low doses (<1 kGy) was unchanged or slightly higher when compared to the unirradiated control samples. Above 1 kGy dispersion viscosity decreased with increasing dose. For these polysaccharides chain hydrolysis seems to occur during irradiation at all doses resulting in an increase in the amount of soluble polymer and hence increased viscosity at low doses, whilst at high doses viscosity decreases due to extensive polymer hydrolysis. Similar electron spin resonance (ESR) spectra were obtained at low and high doses with a stronger signal at the higher dose. (Author).

Gummed-up memory: Chewing gum impairs short-term recall

OpenAIRE

Kozlov, Michail D; Hughes, Robert W; Jones, Dylan M

2012-01-01

Several studies have suggested that short-term memory is generally improved by chewing gum. However, we report the first studies to show that chewing gum impairs short-term memory for both item order and item identity. Experiment 1 showed that chewing gum reduces serial recall of letter lists. Experiment 2 indicated that chewing does not simply disrupt vocal-articulatory planning required for order retention: Chewing equally impairs a matched task that required retention of list item identity...

Insights in the Rhodium-Catalyzed Tandem Isomerization-Hydroformylation of 10-Undecenitrile: Evidence for a Fast Isomerization Regime

Directory of Open Access Journals (Sweden)

Lucas Le Goanvic

2018-04-01

Full Text Available The tandem isomerization-hydroformylation of 10-undecenitrile (1 into the corresponding linear aldehyde (2 with a Rh-biphephos system was studied and the formation of internal olefin isomers (1-int-x was monitored over time. The existence of an “isomerization phenomenon” was evidenced, where fast isomerization of 1 into up to 70% of 1-int-x followed by fast back-isomerization of 1-int-x into 1 and, in turn, into 2 occurs. This fast dynamic isomerization regime is favored at high syngas pressure (40 bar and low biphephos-to-Rh ratio (5–10, and it is best observed at relatively high catalyst loadings ([1]0/[Rh] ≤ 3000. The latter regime is indeed evanescent, and gives place to a second stage in which isomerization of internal olefins (and eventual conversion into 2 proceeds much more slowly. The results are tentatively rationalized by the formation of an unstable species that promotes dynamic isomerization and which slowly vanishes or collapses into a Rh-biphephos species which is the one responsible for hydroformylation.

Structural, thermal and rheological characterization of modified Dalbergia sissoo gum--A medicinal gum.

Science.gov (United States)

Munir, Hira; Shahid, Muhammad; Anjum, Fozia; Mudgil, Deepak

2016-03-01

Dalbergia sissoo gum was purified by ethanol precipitation. The purified gum was modified and hydrolyzed. Gum was modified by performing polyacrylamide grafting and carboxymethylation methods. The hydrolysis was carried out by using mannanase, barium hydroxide and trifluoroacetic acid. The modified and hydrolyzed gums were characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The decrease in viscosity was studied by performing the flow test. The modified and hydrolyzed gums were thermally stable as compared to crude gum. There was increase in crystallinity after modification and hydrolysis, determined through XRD. FTIR analysis exhibits no major transformation of functional group, only there was change in the intensity of transmittance. It is concluded that the modified and hydrolyzed gum can be used for pharmaceutical and food industry. Copyright © 2015 Elsevier B.V. All rights reserved.

Is isomerism a risk factor for intestinal volvulus?

Science.gov (United States)

Landisch, Rachel M; Loomba, Rohit S; Salazar, Jose H; Buelow, Matthew W; Frommelt, Michele; Anderson, Robert H; Wagner, Amy J

2018-03-06

Isomerism, or heterotaxy syndrome, affects many organ systems anatomically and functionally. Intestinal malrotation is common in patients with isomerism. Despite a low reported risk of volvulus, some physicians perform routine screening and prophylactic Ladd procedures on asymptomatic patients with isomerism who are found to have intestinal malrotation. The primary aim of this study was to determine if isomerism is an independent risk factor for volvulus. Kid's Inpatient Database data from 1997 to 2012 was utilized for this study. Characteristics of admissions with and without isomerism were compared with a particular focus on intestinal malrotation, volvulus, and Ladd procedure. A logistic regression was conducted to determine independent risk factors for volvulus with respect to isomerism. 15,962,403 inpatient admissions were included in the analysis, of which 7970 (0.05%) patients had isomerism, and 6 patients (0.1%) developed volvulus. Isomerism was associated with a 52-fold increase in the odds of intestinal malrotation by univariate analysis. Of 251 with isomerism and intestinal malrotation, only 2.4% experienced volvulus. Logistic regression demonstrated that isomerism was not an independent risk factor for volvulus. Isomerism is associated with an increased risk of intestinal malrotation but is not an independent risk factor for volvulus. Prognosis study. Level III. Copyright © 2018 Elsevier Inc. All rights reserved.

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

Science.gov (United States)

2010-04-01

... gum, kelp, methylcellulose, plantago seed (psyllium), polycarbophil tragacanth, and xanthan gum) as... gum, kelp, methylcellulose, plantago seed (psyllium), polycarbophil tragacanth, and xanthan gum) as..., methylcellulose, plantago seed (psyllium), polycarbophil, tragacanth, and xanthan gum. Esophageal obstruction and...

Tragacanth gum

DEFF Research Database (Denmark)

Meyer, Anne S.; Mikkelsen, Jørn Dalgaard; Gavlighi, Hassan Ahmadi

2013-01-01

highly substituted pectin-like structural elements. Enzymatically produced low molecular- weight fractions of tragacanth gum exhibit potential prebiotic activity by promoting growth in vitro of Bifidobacterium longum subsp. infantis strains. These findings may lead to new uses of this gum for production...... of value-added prebiotic compounds for functional foods....

Quantum optimal control of ozone isomerization

International Nuclear Information System (INIS)

Artamonov, Maxim; Ho, Tak-San; Rabitz, Herschel

2004-01-01

We present a feasibility study of ozone isomerization based on a recent ab initio potential energy surface and a model Hamiltonian constructed by holding the bond lengths constant and using the valence angle as the isomerization coordinate. Optimal control theory is used to find an electric field that drives isomerization with a yield of 95% to the symmetric metastable triangular form of ozone. A frequency filter is applied as an additional spectral constraint limiting the field bandwidth. A post-facto analysis is performed showing a degree of inherent robustness of the isomerization yield to field noise

Exudate gums: occurrence, production, and applications.

Science.gov (United States)

Verbeken, D; Dierckx, S; Dewettinck, K

2003-11-01

This paper presents a review of the industrially most relevant exudate gums: gum arabic, gum karya, and gum tragacanth. Exudate gums are obtained as the natural exudates of different tree species and exhibit unique properties in a wide variety of applications. This review covers the chemical structure, occurrence and production of the different gums. It also deals with the size and relative importance of the various players on the world market. Furthermore, it gives an overview of the main application fields of the different gums, both food and non-food.

Fluoroacetic acid in guar gum.

Science.gov (United States)

Vartiainen, T; Gynther, J

1984-04-01

The toxicity of guar gum, derived from the Indian leguminous plant Cyamopsis tetragonolobus, is thought to be due to a globulin which can be denaturated and made non-toxic. Another very toxic compound, fluoroacetic acid, has been detected at a low level in raw samples of guar gum (0.07-1.42 micrograms fluoroacetic acid/g). A sample of a guar-gum pharmaceutical formulation contained only 0.08 ppm fluoroacetate. One exceptionally high value of 9.5 micrograms/g was found in a guar-gum powder. The low concentrations of fluoroacetate found in guar gum dispel any considerations about possible health risks associated with fluoroacetate during the prolonged use of guar gum at the recommended doses.

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

Science.gov (United States)

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

2000-10-01

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

Rheological and interfacial properties at the equilibrium of almond gum tree exudate (Prunus dulcis) in comparison with gum arabic.

Science.gov (United States)

Mahfoudhi, Nesrine; Sessa, Mariarenata; Ferrari, Giovanna; Hamdi, Salem; Donsi, Francesco

2016-06-01

Almond gum contains an arabinogalactan-type polysaccharide, which plays an important role in defining its interfacial and rheological properties. In this study, rheological and interfacial properties of almond gum and gum arabic aqueous dispersions were comparatively investigated. The interfacial tension of almond gum and gum arabic aqueous dispersions was measured using the pendant drop method in hexadecane. The asymptotic interfacial tension values for almond gum were significantly lower than the corresponding values measured for gum arabic, especially at high concentration. Rheological properties were characterized by steady and oscillatory tests using a coaxial geometry. Almond gum flow curves exhibited a shear thinning non-Newtonian behavior with a tendency to a Newtonian plateau at low shear rate, while gum arabic flow curves exhibited such behavior only at high shear rate. The influence of temperature (5-50  ℃) on the flow curves was studied at 4% (m/m) gum concentration and the Newtonian viscosities at infinite and at zero shear rate, for gum arabic and almond gum, respectively, were accurately fitted by an Arrhenius-type equation. The dynamic properties of the two gum dispersions were also studied. Both gum dispersions exhibited viscoelastic properties, with the viscous component being predominant in a wider range of concentrations for almond gum, while for gum arabic the elastic component being higher than the elastic one especially at higher concentrations.The rheological and interfacial tension properties of almond gum suggest that it may represent a possible substitute of gum arabic in different food applications. © The Author(s) 2015.

Isomeric Targets and Beams

International Nuclear Information System (INIS)

Oganesyan, Yu.Ts.; Karamyan, S.A.

1994-01-01

One of the main topics of modern nuclear physics is the investigation of exotic nuclei including hyper-nuclei, trans fermium elements, proton and neutron rich isotopes near drip lines as well as high-spin excited states and states with anomalous deformation. The isomerism of nuclei is closely related with such phenomena as the alignment of single-particle orbitals, the coexistence of various deformations and the manifestation of intruder-levels from neighbouring shells. The investigation of electromagnetic and nuclear interactions of isomers could give important information on their shell structure and its role in the mechanism of nuclear reactions. For such experiments one can either make isomeric targets (sufficiently long-lived) or use the methods of acceleration of isomeric nuclei. Recently, an exotic 16 + four-quasiparticle isomer of 178 Hf m 2 was produced in a micro weight quantity and the first nuclear reactions on it were successfully observed. The talk describes these experiments as well as new ideas for the continuation of the studies and some advantageous ways for the isomeric beams production by the method of direct acceleration or by the secondary beam method. 35 refs., 15 figs., 8 tabs

Chewing gum and context-dependent memory: the independent roles of chewing gum and mint flavour.

Science.gov (United States)

Johnson, Andrew J; Miles, Christopher

2008-05-01

Two experiments independently investigated the basis of the chewing gum induced context-dependent memory effect. At learning and/or recall, participants either chewed flavourless gum (Experiment 1) or received mint-flavoured strips (Experiment 2). No context-dependent memory effect was found with either flavourless gum or mint-flavoured strips, indicating that independently the contexts were insufficiently salient to induce the effect. This is found despite participants' subjective ratings indicating a perceived change in state following administration of flavourless gum or mint-flavoured strips. Additionally, some preliminary evidence for a non-additive facilitative effect of receiving gum or flavour at either learning and/or recall is reported. The findings raise further concerns regarding the robustness of the previously reported context-dependent memory effect with chewing gum.

Experimental grounds for nuclear shape isomerism

International Nuclear Information System (INIS)

Makarenko, V.E.

1995-11-01

Experimental data on fission isomeric states of actinide nuclei - half lives, energies, quantum numbers, decay branches and spectroscopic properties - are discussed. Quite a few results find their explanation in the framework of nuclear shape isomerism hypothesis being the in-thing for about thirty years. Others seem to be the hints to the quasiparticle nature of fission isomers. The problem could be solved by direct measurement of nuclear spin for isomeric states. (author). 44 refs, 1 tab

21 CFR 172.615 - Chewing gum base.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Chewing gum base. 172.615 Section 172.615 Food and..., Chewing Gum Bases and Related Substances § 172.615 Chewing gum base. The food additive chewing gum base... substances listed in paragraph (a) of this section, chewing gum base may also include substances generally...

Dependence on the nicotine gum in former smokers.

Science.gov (United States)

Etter, Jean-François

2009-03-01

We conducted an Internet survey in 2004-2007 in 526 daily users of the nicotine gum, to assess use of, and dependence on the nicotine gum in former smokers. We used modified versions of the Nicotine Dependence Syndrome Scale (NDSS-G), the Cigarette Dependence Scale (CDS-G) and the Fagerström Test (FTND-G). After 30 days, 155 participants (29%) indicated their gum use. Higher dependence on the gum predicted a lower chance of stopping using it at follow-up (odds ratio=0.36 for each standard deviation unit on CDS-G, p=0.001). More long-term (>3 months) than short-term (dependence on the gum than short-term users, as assessed with NDSS-Gum, CDS-Gum and FTND-Gum (all pdependence on the nicotine gum. Lower levels of dependence on the gum predicted cessation of gum use. However, long term use of the nicotine gum has no known serious adverse consequence, and may be beneficial if it prevents late relapse.

Xylene isomerization

KAUST Repository

Bilaus, Rakan Sulaiman; Pinnau, Ingo

2016-01-01

at isomenzation conditions and producing an isomerized product comprising a higher proportion of p-xylene than in the feed mixture, wherein the catalyst comprises an acidic sulfonated catalytic membrane. Xylene isomenzation can also be coupled with a p

Effect of GutsyGum(tm), A Novel Gum, on Subjective Ratings of Gastro Esophageal Reflux Following A Refluxogenic Meal.

Science.gov (United States)

Brown, Rachel; Sam, Cecilia H Y; Green, Tim; Wood, Simon

2015-06-01

Chewing gum alleviates symptoms of gastro-esophageal reflux (GER) following a refluxogenic meal. GutsyGum(tm), a chewing gum developed to alleviate the symptoms of GER contains calcium carbonate, with a proprietary blend of licorice extract, papain, and apple cider vinegar (GiGs®). The efficacy of GutsyGum(tm) was determined in alleviating the symptoms of GER after a refluxogenic meal compared to placebo gum. This double-blind, placebo-controlled-crossover trial with a one-week washout between treatments had 24 participants with a history of GER consume a refluxogenic meal and then chew GutsyGum(tm) or placebo gum. Participants completed GER symptom questionnaires, consisting of symptom based 10 cm Visual Analogue Scales, immediately following the meal and then at regular intervals out to four hours postmeal. Adjusted mean ± SEM heartburn score (15-min postmeal to 240 min) was significantly lower in GutsyGum(tm) than in placebo gum treatment (0.81 ± 0.20 vs. 1.45 ± 0.20 cm; p = 0.034). Mean acid reflux score was significantly lower in GutsyGum(tm) than in placebo treatment (0.72 ± 0.19 vs. 1.46 ± 0.19 cm; p = 0.013). There were no significant differences for any of the secondary outcomes. However, pain approached significance with less pain reported in GutsyGum(tm) versus placebo treatment (0.4 ± 0.2 vs. 0.9 ± 0.2 cm; p = 0.081). Although nausea (p = 0.114) and belching (p = 0.154) were lower following GutsyGum(tm), the difference was not statistically significant. GutsyGum(tm) is more effective than a placebo gum in alleviating primary symptoms of heartburn and acid reflux (Clinical Trial Registration: ACTRN12612000973819).

Experiments with neutron-rich isomeric beams

International Nuclear Information System (INIS)

Rykaczewski, K.; Lewitowicz, M.; Pfuetzner, M.

1998-01-01

A review of experimental results obtained on microsecond-isomeric states in neutron-rich nuclei produced in fragmentation reactions and studied with SISSI-Alpha-LISE3 spectrometer system at GANIL Caen is given. The perspectives of experiments based on secondary reactions with isomeric beams are presented

Occupational allergic rhinitis from guar gum.

Science.gov (United States)

Kanerva, L; Tupasela, O; Jolanki, R; Vaheri, E; Estlander, T; Keskinen, H

1988-05-01

Three cases of allergic rhinitis from a vegetable gum, guar gum, have been detected. Two subjects were exposed to fine guar gum powder (Emco Gum 563, Meyhall Chemical AG, Switzerland), an insulator in rubber cables, when opening cables in a power cable laboratory. After 1-2 years' exposure the patients developed rhinitis. Scratch-chamber tests, nasal provocation tests, nasal eosinophilia and a RAST test proved their allergy. A third subject developed allergic rhinitis from another guar gum product (Meyproid 5306, Meyhall Chemical AG) after 2 years' exposure in a paper factory. A positive skin test and nasal provocation test confirmed the diagnosis. A fourth case of possible allergy to guar gum after exposure to Meyproid 5306 in a paper factory is also presented. No final diagnosis was reached in this case (in 1974). The present subjects, only one of whom was atopic, developed allergy within 2 years, although their exposure to guar gum was not especially heavy. Therefore, when handling guar, adequate ventilation facilities should be provided and protective clothing, including a respiratory mask, should be worn.

Determination of locust bean gum and guar gum by polymerase chain reaction and restriction fragment length polymorphism analysis.

Science.gov (United States)

Meyer, K; Rosa, C; Hischenhuber, C; Meyer, R

2001-01-01

A polymerase chain reaction (PCR) was developed to differentiate the thickening agents locust bean gum (LBG) and the cheaper guar gum in finished food products. Universal primers for amplification of the intergenic spacer region between trnL 3' (UAA) exon and trnF (GAA) gene in the chloroplast (cp) genome and subsequent restriction analysis were applied to differentiate guar gum and LBG. The presence of guar gum powder added to LBG powder was detectable. Based on data obtained from sequencing this intergenic spacer region, a second PCR method for the specific detection of guar gum DNA was also developed. This assay detected guar gum powder in LBG in amounts as low as 1% (w/w). Both methods successfully detected guar gum and/or LBG in ice cream stabilizers and in foodstuffs, such as dairy products, ice cream, dry seasoning mixes, a finished roasting sauce, and a fruit jelly product, but not in products with highly degraded DNA, such as tomato ketchup and sterilized chocolate cream. Both methods detected guar gum and LBG in ice cream and fresh cheese at levels <0.1%.

Design, formulation and evaluation of caffeine chewing gum.

Science.gov (United States)

Aslani, Abolfazl; Jalilian, Fatemeh

2013-01-01

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. 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. 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. 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.

Evaluation of certain food additives and contaminants.

Science.gov (United States)

2013-01-01

This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives and a food contaminant with a view to concluding as to safety concerns and to preparing specifications for identity and purity. The first part of the report contains a general discussion of the principles governing the toxicological evaluation of and assessment of dietary exposure to food additives. A summary follows of the Committee's evaluations of technical, toxicological and dietary exposure data for seven food additives (advantame; glucoamylase from Trichoderma reesei expressed in Trichoderma reesei; glycerol ester of gum rosin; glycerol ester of tall oil rosin; glycerol ester of wood rosin; nisin; and octenyl succinic acid modified gum arabic) and an assessment of dietary exposure to cadmium from cocoa and cocoa products. Specifications for the following food additives were revised: annatto extracts (solvent-extracted bixin and solvent-extracted norbixin); Benzoe tonkinensis; food additives containing aluminium and/or silicon; mineral oil (medium viscosity); modified starches; paprika extract; phosphates (analytical methods for the determination of phosphorus and revision of specifications); 3-phytase from Aspergillus niger expressed in Aspergillus niger; potassium aluminium silicate; and potassium aluminium silicate-based pearlescent pigments. Annexed to the report are tables summarizing the Committee's recommendations for dietary exposures to and toxicological evaluations of the food additives and contaminant considered.

Chewing gum can produce context-dependent effects upon memory.

Science.gov (United States)

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

2004-10-01

Two experiments examined whether chewing spearmint gum can affect the initial learning or subsequent recall of a word list. Comparing those participants in Experiment 1 who chewed gum at the learning or the recall phases showed that chewing gum at initial learning was associated with superior recall. In addition, chewing gum led to context-dependent effects as a switch between gum and no gum (or no gum and gum) between learning and recall led to poorer performance. Experiment 2 provided evidence that sucking gum was sufficient to induce some of the same effects as chewing.

Occupational asthma caused by guar gum.

Science.gov (United States)

Lagier, F; Cartier, A; Somer, J; Dolovich, J; Malo, J L

1990-04-01

Some vegetable gums have been reported to cause asthma. We describe three subjects who were exposed at work to guar gum, which is derived from the outer part of Cyanopsis tetragonolobus, a vegetable that grows in India. The first subject worked for a pharmaceutical company; the second and third subjects worked at a carpet-manufacturing plant. All three subjects developed symptoms of rhinitis and asthma after the onset of exposure to guar gum. All subjects were atopic and demonstrated mild bronchial hyperresponsiveness to inhaled histamine at the time they were observed. Skin prick tests demonstrated an immediate skin reaction to guar gum. All three subjects had high levels of serum IgE antibodies to guar gum. Specific inhalation challenges in which the three subjects were exposed for short intervals (less than or equal to 4 minutes) to powder of guar gum elicited isolated immediate bronchospastic reactions in two subjects and a dual reaction in the other subject.

Ti-Catalyzed Selective Isomerization of Terminal Mono-substituted Olefins

International Nuclear Information System (INIS)

Lee, Hyung Soo; Lee, Gab Yong

2005-01-01

The isomerization of olefins occurs either by a metal hydride addition-elimination or by a π-allyl metal hydride intermediate. HCo(CO) 4 , [(C 2 H 4 ) 2 RhCl] 2 , Ni[P(OEt) 3 ] 4 , and PtCl 2 (PPh 3 ) 2 -SnCl 2 are effective catalysts for isomerization of olefins via a metal hydride addition-elimination mechanism, 3,4 and Fe 3 (CO) 12 catalyzed isomerization of 3-ethyl-1-pentene and isomerization of 1-heptene catalyzed by (PhCN) 2 PdCl 2 occur via a π-allyl metal hydride mechanism. The cis/trans ratio of 2-butene obtained from isomerization of 1-butene by RhH(CO)(PPh 3 ) 3 has also been investigated. The skeletal isomerization of olefins catalyzed by (R 3 P) 2 NiCl 2 is developed such as conversion of cis-1,4-hexadiene to trans-2-methyl-1,3-pentadiene. Titanium complexes serve as an effective catalysts for a variety of reactions such as hydroalumination, hydroboration, and hydrogenation of unsaturated hydrocarbons. We have been interested in the selective reactions of unsaturated hydrocarbons by using titanium and zirconium compounds. The reagent system composed of LiAlH 4 /Cp 2 TiCl 2 ≤ 2 in the molar ratio promotes the isomerization of 1-octene, but the detailed reaction for isomerization of olefins has not been reported. We report here a selective isomerization of olefins with low valent titanium complex generated from Cp 2 TiCl 2 (Cp=cyclopentadienyl) and LiAlH 4

Oral health benefits of chewing gum

NARCIS (Netherlands)

Wessel, Stefan

2016-01-01

In the last decades sugar-free chewing gum has developed in an oral healthcare product, next to the conventional products such as the toothbrush and mouthrinses. In this thesis we investigate the oral health benefits of chewing gum and the effects of additives to chewing gum, such as antimicrobials.

Chewing gum and context-dependent memory: The independent roles of chewing gum and mint flavour

OpenAIRE

Johnson, A.J.; Miles, C.

2008-01-01

Two experiments independently investigated the basis of the chewing-gum induced context-dependent memory effect (Baker et al, 2004). At learning and/or recall participants either chewed flavourless gum (Experiment 1) or received mint-flavoured strips (Experiment 2). No context dependent memory effect was found with either flavourless gum or mint-flavoured strips, indicating that independently the contexts were insufficiently salient to induce the effect. This is found despite participants’ su...

Gums, badgers, and economics

CSIR Research Space (South Africa)

Van Wilgen, BW

2007-01-01

Full Text Available Gums trees (in the genus Eucalyptus, from Australia) are not set to ‘disappear’ (even if some people wanted them to). Gums form an important component of the forest industry and, at last count, they covered over 540 000 ha in formal plantations...

21 CFR 184.1351 - Gum tragacanth.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Gum tragacanth. 184.1351 Section 184.1351 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1351 Gum tragacanth. (a) Gum tragacanth is the exudate from one of several...

The CT appearance of intraoral chewing gum

Energy Technology Data Exchange (ETDEWEB)

Towbin, Alexander J. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

2008-12-15

When imaged, intraoral chewing gum has the potential to be misdiagnosed. Chewing gum has a characteristic appearance on CT: it is ovoid in shape, hyperdense, and has small internal locules of air. Reports have described the appearance of gum on radiographs and abdominal CT images; however, no reports could be found detailing its appearance within the mouth. This report describes the appearance of intraoral chewing gum as well as the properties of the gum that lead to this appearance. Because of the potential for misdiagnosis, screening for intraoral foreign bodies should be considered prior to imaging. (orig.)

The CT appearance of intraoral chewing gum

International Nuclear Information System (INIS)

Towbin, Alexander J.

2008-01-01

When imaged, intraoral chewing gum has the potential to be misdiagnosed. Chewing gum has a characteristic appearance on CT: it is ovoid in shape, hyperdense, and has small internal locules of air. Reports have described the appearance of gum on radiographs and abdominal CT images; however, no reports could be found detailing its appearance within the mouth. This report describes the appearance of intraoral chewing gum as well as the properties of the gum that lead to this appearance. Because of the potential for misdiagnosis, screening for intraoral foreign bodies should be considered prior to imaging. (orig.)

Cat's claw oxindole alkaloid isomerization induced by common extraction methods

Directory of Open Access Journals (Sweden)

Samuel Kaiser

2013-01-01

Full Text Available Cat's claw oxindole alkaloids are prone to isomerization in aqueous solution. However, studies on their behavior in extraction processes are scarce. This paper addressed the issue by considering five commonly used extraction processes. Unlike dynamic maceration (DM and ultrasound-assisted extraction, substantial isomerization was induced by static maceration, turbo-extraction and reflux extraction. After heating under reflux in DM, the kinetic order of isomerization was established and equations were fitted successfully using a four-parameter Weibull model (R² > 0.999. Different isomerization rates and equilibrium constants were verified, revealing a possible matrix effect on alkaloid isomerization.

Gum Producers Can Improve Quality Of Gum Marketed and Get Higher Prices

Science.gov (United States)

Ralph W. Clements

1979-01-01

Acid waste from over-treatment and old, wornout iron cups have contributed significantly to the generally poor quality of gum marketed. Today producers are reluctant to purchase new cups and gutters and invest up to $1.80 per tree for production when the market price for gum averages 14.54 per pound annually. Guidelines are given for improving the quality by...

Examining disadoption of gum arabic production in Sudan

NARCIS (Netherlands)

Rahim, A.; Ruben, R.; Ierland, van E.C.

2008-01-01

Gum arabic production in Sudan has developed over the years in a well-established traditional bush-fallow system in which the gum tree (Acacia senegal) is rotated with annual crops. Following the Sahel drought, the gum area has suffered from deforestation and gum production has declined. Several

Flavor-Enhanced Modulation of Cerebral Blood Flow during Gum Chewing.

Directory of Open Access Journals (Sweden)

Yoko Hasegawa

Full Text Available Flavor perception, the integration of taste and odor, is a critical factor in eating behavior. It remains unclear how such sensory signals influence the human brain systems that execute the eating behavior.WE TESTED CEREBRAL BLOOD FLOW (CBF IN THE FRONTAL LOBES BILATERALLY WHILE SUBJECTS CHEWED THREE TYPES OF GUM WITH DIFFERENT COMBINATIONS OF TASTE AND ODOR: no taste/no odor gum (C-gum, sweet taste/no odor gum (T-gum, and sweet taste/lemon odor gum (TO-gum. Simultaneous recordings of transcranial Doppler ultrasound (TCD and near infrared spectrometer (NIRS were used to measure CBF during gum chewing in 25 healthy volunteers. Bilateral masseter muscle activity was also monitored.We found that subjects could discriminate the type of gum without prior information. Subjects rated the TO-gum as the most flavorful gum and the C-gum as the least flavorful. Analysis of masseter muscle activity indicated that masticatory motor output during gum chewing was not affected by taste and odor. The TCD/NIRS measurements revealed significantly higher hemodynamic signals when subjects chewed the TO-gum compared to when they chewed the C-gum and T-gum.These data suggest that taste and odor can influence brain activation during chewing in sensory, cognitive, and motivational processes rather than in motor control.

Chewing gum moderates the vigilance decrement.

Science.gov (United States)

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

2014-05-01

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. © 2013 The British Psychological Society.

Isomers chart; Table des isomeres

Energy Technology Data Exchange (ETDEWEB)

Dupont-Gautier, P; Chantelot, S; Moisson, N [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

The nuclear isomers are nuclides offering the same mass number and the same atomic number, but different energy levels. In the following chart the zero energy ground states are omitted and the metastable isomers, i.e. of non-zero energy, known and of measurable lifetime, are listed. The lower limit of this lifetime was set here to 0.1 x 10{sup -6} s. The various isomers were classified in increasing lifetimes. (authors) [French] Les isomeres nucleaires sont des nucleides presentant le meme nombre de masse et le meme numero atomique, mais des niveaux energetiques differents. Dans la table suivante, on a neglige les etats fondamentaux d'energie nulle et on a recense les isomeres metastables, c'est-a-dire d'energie non nulle, connus et de periode mesurable. La limite inferieure de cette periode a ete fixee ici a 0,1 x 10{sup -6} s. Les differents isomeres ont ete classes par periodes croissantes. (auteurs)

Isomers chart; Table des isomeres

Energy Technology Data Exchange (ETDEWEB)

Dupont-Gautier, P.; Chantelot, S.; Moisson, N. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

The nuclear isomers are nuclides offering the same mass number and the same atomic number, but different energy levels. In the following chart the zero energy ground states are omitted and the metastable isomers, i.e. of non-zero energy, known and of measurable lifetime, are listed. The lower limit of this lifetime was set here to 0.1 x 10{sup -6} s. The various isomers were classified in increasing lifetimes. (authors) [French] Les isomeres nucleaires sont des nucleides presentant le meme nombre de masse et le meme numero atomique, mais des niveaux energetiques differents. Dans la table suivante, on a neglige les etats fondamentaux d'energie nulle et on a recense les isomeres metastables, c'est-a-dire d'energie non nulle, connus et de periode mesurable. La limite inferieure de cette periode a ete fixee ici a 0,1 x 10{sup -6} s. Les differents isomeres ont ete classes par periodes croissantes. (auteurs)

Easy Synthesis of Two Positional Isomeric Tetrazole Libraries

NARCIS (Netherlands)

Wang, Yuanze; Patil, Pravin; Dömling, Alexander

2016-01-01

A fast and efficient synthesis of libraries of positional isomeric 1H-tetrazoles and 5H-tetrazoles, for the purpose of testing binding hypothesis of isomeric tetrazoles in fragment-based drug discovery, is described.

Tracer kinetic investigations on isomerization and synthesis of /sup 8/C-aromates. II. Isomerization of ethylbenzene by means of heterogeneous catalysts

Energy Technology Data Exchange (ETDEWEB)

Dermietzel, J; Roesseler, M; Jockisch, W; Wienhold, C [Akademie der Wissenschaften der DDR, Leipzig. Zentralinstitut fuer Isotopen- und Strahlenforschung; Franke, H; Klempin, J; Barz, H J [VEB Petrolchemisches Kombinat Schwedt (German Democratic Republic)

1978-01-01

The mechanism of ethylbenzene isomerization on Pt/Al/sub 2/O/sub 3/ catalysts by means of /sup 14/C labelled compounds has been investigated, measuring the isotope distribution between ring and alkyl carbon atoms. The results suggest that ethylbenzene isomerizes via structure rearrangement involving ring carbon atoms. A similar mechanism takes place in xylene isomerization under increased hydrogen partial pressure, while under normal pressure 1,2-methyl group shifting is dominating. All three xylenes are formed from ethylbenzene by parallel reactions.

GumTree-An integrated scientific experiment environment

International Nuclear Information System (INIS)

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

2006-01-01

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

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

Directory of Open Access Journals (Sweden)

Saroea Geoffrey

2008-08-01

Full Text Available Abstract Background Extrinsic staining of teeth may result from the deposition of a variety of pigments into or onto the tooth surface, which originate mainly from diet or from tobacco use. More recently, clinical studies have demonstrated the efficacy of some chewing gums in removing extrinsic tooth staining. The aim of this study was to assess the effectiveness of two nicotine medicated chewing gums (A and B on stain removal in an in vitro experiment, when compared with a confectionary whitening chewing gum (C and human saliva (D. Methods Bovine incisors were stained by alternating air exposure and immersion in a broth containing natural pigments such as coffee, tea and oral microorganisms for 10 days. Stained enamel samples were exposed to saliva alone or to the test chewing gums under conditions simulating human mastication. The coloration change of the enamel samples was measured using a spectrophotometer. Measurements were obtained for each specimen (average of three absorbances using the L*a*b scale: lightness (L*, red-green (a and yellow-blue (b. Results Medicated chewing gums (A and B removed a greater amount of visible extrinsic stain, while the confectionary chewing gum with a whitening claim (C had a milder whitening effect as evaluated by quantitative and qualitative assessment. Conclusion The tested Nicotine Replacement Therapy (NRT chewing gums were more effective in the removal of the extrinsic tooth stain. This visible improvement in tooth whitening appearance could strengthen the smokers' motivation to quit smoking.

What do GUM physicians think should be taught in a modern undergraduate GUM module? A qualitative inquiry.

Science.gov (United States)

Fernando, I

2015-10-01

Traditional undergraduate Genitourinary Medicine (GUM) teaching in the UK concentrated on the management of individual sexually transmitted infections. There is significant variation, however, in the GUM teaching provided by different medical schools today. I undertook a qualitative interview study to gather views of GUM and other sexual health clinicians regarding what should be taught within a modern undergraduate GUM module. Nine GUM clinicians and two Sexual and Reproductive Health (SRH) clinicians participated in the study; all were directly involved in undergraduate teaching. Semi-structured interviews were conducted with study participants by a single interviewer, focusing on three key topics: their individual opinions regarding important learning outcomes (LOs) for a modern model GUM curriculum, their preferred teaching methods and the total recommended teaching time required. Interviews were audio-recorded with consent and professionally transcribed. Data were analysed by the content analysis method. Interviewees frequently stressed skill and attitudinal LOs, even above knowledge. Recommended important skills included sexual history taking, HIV risk assessment and testing, and male and female genital examination. Recommended attitudinal LOs were developing an open and non-judgemental approach to sexual health issues and understanding sexual well-being to be an important component of general health. Respondents were keen for a mixture of teaching methods, but generally agreed that clinic attendance and experiential learning were beneficial. They preferred that GUM teaching should be delivered in the latter years of the undergraduate curriculum. © The Author(s) 2015.

Graphene oxide catalyzed cis-trans isomerization of azobenzene

Directory of Open Access Journals (Sweden)

Dongha Shin

2014-09-01

Full Text Available We report the fast cis-trans isomerization of an amine-substituted azobenzene catalyzed by graphene oxide (GO, where the amine functionality facilitates the charge transfer from azobenzene to graphene oxide in contrast to non-substituted azobenzene. This catalytic effect was not observed in stilbene analogues, which strongly supports the existence of different isomerization pathways between azobenzene and stilbene. The graphene oxide catalyzed isomerization is expected to be useful as a new photoisomerization based sensing platform complementary to GO-based fluorescence quenching methods.

Rheological Modeling and Characterization of Ficus platyphylla Gum Exudates

Directory of Open Access Journals (Sweden)

Nnabuk O. Eddy

2013-01-01

Full Text Available Ficus platyphylla gum exudates (FP gum have been analyzed for their physicochemical parameters and found to be ionic, mildly acidic, odourless, and yellowish brown in colour. The gum is soluble in water, sparingly soluble in ethanol, and insoluble in acetone and chloroform. The nitrogen (0.39% and protein (2.44% contents of the gum are relatively low. The concentrations of the cations were found to increase according to the following trend, Mn>Fe>Zn>Pb>Cu>Mg>Cd>Ca. Analysis of the FTIR spectrum of the gum revealed vibrations similar to those found in polysaccharides while the scanning electron micrograph indicated that the gum has irregular molecular shapes, arranged randomly. The intrinsic viscosity of FP gum estimated by extrapolating to zero concentrations in Huggins, Kraemer, Schulz-Blaschke, and Martin plots has an average value of 7 dL/g. From the plots of viscosity versus shear rate/speed of rotation and also that of shear stress versus shear rate, FP gum can be classified as a non-Newtonian gum with characteristics-plastic properties. Development of the Master_s curve for FP gum also indicated that the gum prefers to remain in a dilute domain (Cgum (calculated from Arrhenius-Frenkel-Eyring plot was relatively low and indicated the presence of fewer inter- and intramolecular interactions.

Gellan Gum: Fermentative Production, Downstream Processing and Applications

Directory of Open Access Journals (Sweden)

Ishwar B. Bajaj

2007-01-01

Full Text Available The microbial exopolysaccharides are water-soluble polymers secreted by microorganisms during fermentation. The biopolymer gellan gum is a relatively recent addition to the family of microbial polysaccharides that is gaining much importance in food, pharmaceutical and chemical industries due to its novel properties. It is commercially produced by C. P. Kelco in Japan and the USA. Further research and development in biopolymer technology is expected to expand its use. This article presents a critical review of the available information on the gellan gum synthesized by Sphingomonas paucimobilis with special emphasis on its fermentative production and downstream processing. Rheological behaviour of fermentation broth during fermentative production of gellan gum and problems associated with mass transfer have been addressed. Information on the biosynthetic pathway of gellan gum, enzymes and precursors involved in gellan gum production and application of metabolic engineering for enhancement of yield of gellan gum has been specified. Characteristics of gellan gum with respect to its structure, physicochemical properties, rheology of its solutions and gel formation behaviour are discussed. An attempt has also been made to review the current and potential applications of gellan gum in food, pharmaceutical and other industries.

Optimizing gelling parameters of gellan gum for fibrocartilage tissue engineering.

Science.gov (United States)

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

2011-08-01

Gellan gum is an attractive biomaterial for fibrocartilage tissue engineering applications because it is cell compatible, can be injected into a defect, and gels at body temperature. However, the gelling parameters of gellan gum have not yet been fully optimized. The aim of this study was to investigate the mechanics, degradation, gelling temperature, and viscosity of low acyl and low/high acyl gellan gum blends. Dynamic mechanical analysis showed that increased concentrations of low acyl gellan gum resulted in increased stiffness and the addition of high acyl gellan gum resulted in greatly decreased stiffness. Degradation studies showed that low acyl gellan gum was more stable than low/high acyl gellan gum blends. Gelling temperature studies showed that increased concentrations of low acyl gellan gum and CaCl₂ increased gelling temperature and low acyl gellan gum concentrations below 2% (w/v) would be most suitable for cell encapsulation. Gellan gum blends were generally found to have a higher gelling temperature than low acyl gellan gum. Viscosity studies showed that increased concentrations of low acyl gellan gum increased viscosity. Our results suggest that 2% (w/v) low acyl gellan gum would have the most appropriate mechanics, degradation, and gelling temperature for use in fibrocartilage tissue engineering applications. Copyright © 2011 Wiley Periodicals, Inc.

Extraction and Characterization of Boswellia Serrata Gum as Pharmaceutical Excipient.

Science.gov (United States)

Panta, Sumedha; Malviya, Rishabha; Sharma, Pramod

2015-01-01

This manuscript deals with the purification and characterization of Boswellia serrata gum as a suspending agent. The Boswellia serrata gum was purchased as crude material, purified and further characterized in terms of organoleptic properties and further micromeritic studies were carried out to characterize the polymer as a pharmaceutical excipient. The suspending properties of the polymer were also evaluated. The results showed that the extracted gum possesses optimum organoleptic as well as micromeritic and suspending properties. To characterize Boswellia serrata gum as a natural excipient. Boswellia serrata gum, paracetamol, distilled water. The results showed that the extracted gum possesses optimum organoleptic as well as micromeritic and suspending properties. It is concluded from the research work that the gum extracted from Boswellia serrata shows the presence of carbohydrates after chemical tests. All the organoleptic properties evaluated were found to be acceptable. The pH was found to be slightly acidic. Swelling Index reveals that the gum swells well in water. Total ash value was within the limits. The values of angle of repose and Carr's Index of powdered gum powder showed that the flow property was good. IR spectra confirmed the presence of alcohol, amines, ketones, anhydrides and aromatic rings. The suspending properties of Boswellia serrata gum were found to be higher as compared to gum acacia while the flow rate of Boswellia serrata gum (1% suspension) was less than gum acacia (1% suspension). The viscosity measurement of both Boswellia serrata gum suspension and gum acacia suspension showed approximately similar results.

GumTree - An Integrated Scientific Experiment Environment

International Nuclear Information System (INIS)

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

2005-01-01

Full text: 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. (authors)

Thermal E/ Z Isomerization in First Generation Molecular Motors.

Science.gov (United States)

Kuwahara, Shunsuke; Suzuki, Yuri; Sugita, Naoya; Ikeda, Mari; Nagatsugi, Fumi; Harada, Nobuyuki; Habata, Yoichi

2018-04-20

Determination of a thermal E/ Z isomerization barrier of first generation molecular motors is reported. Stable ( E)-1a directly converts to stable ( Z)-1c without photochemical E/ Z isomerization. The activation Gibbs energy of the isomerization was determined to be 123 kJ mol -1 by circular dichroism spectral changes. Density functional theory calculations show that ( Z)-1c is ∼11.4 kJ mol -1 more stable than ( E)-1a.

Nanodisturbances in deformed Gum Metal

International Nuclear Information System (INIS)

Gutkin, Mikhail Yu.; Ishizaki, Toshitaka; Kuramoto, Shigeru; Ovid'ko, Ilya A.

2006-01-01

Systematic experiments have been performed to characterize defect structures in deformed Gum Metal, a special titanium alloy with high strength, low Young's modulus, excellent cold workability and low resistance to shear in certain crystallographic planes. Results from high-resolution transmission electron microscopy characterization reveal nanodisturbances (planar nanoscopic areas of local shear) as typical elements of defect structures in deformed Gum Metal. A theoretical model is suggested describing nanodisturbances as nanoscale dipoles of non-conventional partial dislocations with arbitrary, non-quantized Burgers vectors. It is shown theoretically that the homogeneous generation of nanodisturbances is energetically favorable in Gum Metal, where they effectively carry plastic flow

Designing bifunctional alkene isomerization catalysts using predictive modelling

NARCIS (Netherlands)

Landman, I.R.; Paulson, E.R.; Rheingold, A.L.; Grotjahn, D.B.; Rothenberg, G.

2017-01-01

Controlling the isomerization of alkenes is important for the manufacturing of fuel additives, fine-chemicals and pharmaceuticals. But even if isomerization seems to be a simple unimolecular process, the factors that govern catalyst performance are far from clear. Here we present a set of models

Isolation and characterization of gum from Chrysophyllum albidum ...

African Journals Online (AJOL)

This study describes the morphology, physicochemical and compressional characteristics of a natural gum derived from the fruits of Chrysophyllum albidum. Preliminary phytochemical screening and physicochemical properties of Chrysophyllum albidum gum (in comparison with tragacanth gum) were determined while ...

GumTree: Data reduction

Energy Technology Data Exchange (ETDEWEB)

Rayner, Hugh [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)]. E-mail: hrz@ansto.gov.au; Hathaway, Paul [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Hauser, Nick [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Fei, Yang [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Franceschini, Ferdi [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Lam, Tony [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

2006-11-15

Access to software tools for interactive data reduction, visualisation and analysis during a neutron scattering experiment enables instrument users to make informed decisions regarding the direction and success of their experiment. ANSTO aims to enhance the experiment experience of its facility's users by integrating these data reduction tools with the instrument control interface for immediate feedback. GumTree is a software framework and application designed to support an Integrated Scientific Experimental Environment, for concurrent access to instrument control, data acquisition, visualisation and analysis software. The Data Reduction and Analysis (DRA) module is a component of the GumTree framework that allows users to perform data reduction, correction and basic analysis within GumTree while an experiment is running. It is highly integrated with GumTree, able to pull experiment data and metadata directly from the instrument control and data acquisition components. The DRA itself uses components common to all instruments at the facility, providing a consistent interface. It features familiar ISAW-based 1D and 2D plotting, an OpenGL-based 3D plotter and peak fitting performed by fityk. This paper covers the benefits of integration, the flexibility of the DRA module, ease of use for the interface and audit trail generation.

GumTree: Data reduction

International Nuclear Information System (INIS)

Rayner, Hugh; Hathaway, Paul; Hauser, Nick; Fei, Yang; Franceschini, Ferdi; Lam, Tony

2006-01-01

Access to software tools for interactive data reduction, visualisation and analysis during a neutron scattering experiment enables instrument users to make informed decisions regarding the direction and success of their experiment. ANSTO aims to enhance the experiment experience of its facility's users by integrating these data reduction tools with the instrument control interface for immediate feedback. GumTree is a software framework and application designed to support an Integrated Scientific Experimental Environment, for concurrent access to instrument control, data acquisition, visualisation and analysis software. The Data Reduction and Analysis (DRA) module is a component of the GumTree framework that allows users to perform data reduction, correction and basic analysis within GumTree while an experiment is running. It is highly integrated with GumTree, able to pull experiment data and metadata directly from the instrument control and data acquisition components. The DRA itself uses components common to all instruments at the facility, providing a consistent interface. It features familiar ISAW-based 1D and 2D plotting, an OpenGL-based 3D plotter and peak fitting performed by fityk. This paper covers the benefits of integration, the flexibility of the DRA module, ease of use for the interface and audit trail generation

Iodine-Catalyzed Isomerization of Dimethyl Muconate

Energy Technology Data Exchange (ETDEWEB)

Settle, Amy E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Berstis, Laura R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhang, Shuting [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rorrer, Nicholas [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hu, Haiming [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Richards, Ryan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Crowley, Michael F [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vardon, Derek R [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-04-12

cis,cis-Muconic acid is a platform biobased chemical that can be upgraded to drop-in commodity and novel monomers. Among the possible drop-in products, dimethyl terephthalate can be synthesized via esterification, isomerization, Diels-Alder cycloaddition, and dehydrogenation. The isomerization of cis,cis-dimethyl muconate (ccDMM) to the trans,trans-form (ttDMM) can be catalyzed by iodine; however, studies have yet to address (i) the mechanism and reaction barriers unique to DMM, and (ii) the influence of solvent, potential for catalyst recycle, and recovery of high-purity ttDMM. To address this gap, we apply a joint computational and experimental approach to investigate iodine-catalyzed isomerization of DMM. Density functional theory calculations identified unique regiochemical considerations due to the large number of halogen-diene coordination schemes. Both transition state theory and experiments estimate significant barrier reductions with photodissociated iodine. Solvent selection was critical for rapid kinetics, likely due to solvent complexation with iodine. Under select conditions, ttDMM yields of 95% were achieved in <1 h with methanol, followed by high purity recovery (>98%) with crystallization. Lastly, post-reaction iodine can be recovered and recycled with minimal loss of activity. Overall, these findings provide new insight into the mechanism and conditions necessary for DMM isomerization with iodine to advance the state-of-the-art for biobased chemicals.

Design, formulation and evaluation of nicotine chewing gum.

Science.gov (United States)

Aslani, Abolfazl; Rafiei, Sahar

2012-01-01

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. 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. 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 F(19-SC) and F(20-SC), respectively) had optimal chewing hardness, adhering to teeth, and plumpness characteristics, as well as the most pleasant taste and highest acceptability to smokers. 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.

Design, formulation and evaluation of caffeine chewing gum

Directory of Open Access Journals (Sweden)

Abolfazl Aslani

2013-01-01

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.

Elastic properties of Gum Metal

International Nuclear Information System (INIS)

Kuramoto, Shigeru; Furuta, Tadahiko; Hwang, Junghwan; Nishino, Kazuaki; Saito, Takashi

2006-01-01

In situ X-ray diffraction measurements under tensile loading and dynamic mechanical analysis were performed to investigate the mechanisms of elastic deformation in Gum Metal. Tensile stress-strain curves for Gum Metal indicate that cold working substantially decreases the elastic modulus while increasing the yield strength, thereby confirming nonlinearity in the elastic range. The gradient of each curve decreased continuously to about one-third its original value near the elastic limit. As a result of this decrease in elastic modulus and nonlinearity, elastic deformability reaches 2.5% after cold working. Superelasticity is attributed to stress-induced martensitic transformations, although the large elastic deformation in Gum Metal is not accompanied by a phase transformation

Characterizing gamma fields using isomeric activation ratios

Science.gov (United States)

Venkataraman, Ramkumar; Fleming, Ronald F.

1994-12-01

Isomeric activities were induced in indium by gamma irradiation in three different gamma fields, through the reactions 115In(γ, γ') 115mIn and 113In(γ, γ') 113mIn. The irradiation fields were (i) the 15 kCi 60Co source available in the University, (ii) the spent fuel gamma irradiator in the pool of the University's Ford Nuclear Reactor (FNR) and (iii) south face of the core of the FNR during routine shut downs. Isomeric activation ratios can serve to characterize gamma fields, provided the response functions of the two (γ, γ') reactions sample different energy regimes of the gamma spectrum present in the irradiation fields. The response of an isomeric activation detector, in turn, depends on the number of activation energy levels of the nuclide and the probabilities with which the activation levels de-populate to the isomeric level. The reaction rate ratio RIn115m/ RIn113m was measured in the three gamma fields. The measured ratios were (i) 1.210 ± 0.011 in the 60Co source, (ii) 1.314 ± 0.060 in the spent fuel gamma irradiator and (iii) 1.298 ± 0.039 in a location alongside the FNR core during routine shut downs. The measured reaction rate ratios are not only close to each other, but close to unity as well. This indicates that the excitation functions for the reactions 115In(γ, γ') 115mIn and 113In(γ, γ') 113mIn have similar shapes and that for the nuclides 115In and 113In, the number of activation energy levels and the probabilities with which they populate the isomeric levels are very similar to each other. Thus, the ratio RIn115m/ RIn113m will not yield any information regarding the shape of gamma spectrum in the field of measurement. However by choosing (γ, γ') reactions with different shapes for the excitation functions one can measure a set of isomeric activation ratios that characterize a given gamma field.

Study on plant Gums and their new development in application: with focus on tragacanth, guar and arabic Gum; a short review

Directory of Open Access Journals (Sweden)

F. Hassanpour

2016-01-01

Full Text Available Gums refer to a type of polysaccharides which are used to increase viscosity and create some other functional properties such as thickening agent, emulsifying agent, stabilizer, crystal inhibitor and so forth. They are classifying based on their nature and originality including, microbial, plant, exudate and animal Gums. This article shortly reviews a group of plant Gums and recent findings in their application. Gums or Hydrocolloids are main compounds which create stability of emulsion via entering into water phase. The importance of these compounds is on viscosity and electrostatic reactions to stabilize nonalcoholic emulsion with below properties; 1 easily soluble in cold water, 2 the lowest amount of viscosity in water, 3 having maximum level of emulsifier amount, 4 no creation of gelling. Diversity and functionality of Gums and regarding their still novelty in food industries have made Gums one of the main additives in food formulations. Since sourced of Gums are different we must focus on using them together to improve their synergistic effect but interactions among them and combined matrixes produced by them also need to be studied in details.

Nicotine Gum

Science.gov (United States)

... with a smoking cessation program, which may include support groups, counseling, or specific behavioral change techniques. Nicotine gum ... and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or ...

Stabilization of emulsions by gum tragacanth (Astragalus spp.) correlates to the galacturonic acid content and methoxylation degree of the gum

DEFF Research Database (Denmark)

Ahmadi Gavlighi, Hassan; Meyer, Anne S.; Abang Zaidel, Dayang Norulfairuz

2013-01-01

Gum tragacanth samples from six species of Iranian Astragalus bush plants (“goat's-horn”) were evaluated for their emulsion stabilizing effects and their detailed chemical composition in order to examine any possible correlation between the make-up and the emulsion stabilizing properties of gum......:50 (A. rahensis, A. microcephalus, A. compactus) or tipped toward higher bassorin than tragacanthin (A. gossypinus). The monosaccharide make-up of the six gums also varied, but all the gums contained relatively high levels of galacturonic acid (∼100–330 mg/g), arabinose (50–360 mg/g), xylose (∼150...

Phytase application in chewing gum - A technical assessment

DEFF Research Database (Denmark)

Nielsen, Anne Veller Friis; Meyer, Anne S.

2016-01-01

either prior to ingestion, i.e. in the food, or post ingestion, i.e. in the human gastrointestinal tract. We have assessed the technical aspects of formulation and release of phytase added to chewing gum as a delivery vehicle. Phytases from Aspergillus niger and Escherichia coli incorporated into chewing...... gum were released quantitatively upon chewing and retained phytase activity (50-80% of the enzyme activity added was released within 10 minutes). Initial evaluations of phytase chewing gum shelf life showed good stability after 48 days of storage of the chewing gum at ambient conditions....

Radiochemical study of isomerization of free butyl cations

International Nuclear Information System (INIS)

Sinotova, E.N.; Nefedov, V.D.; Skorokhodov, S.S.; Arkhipov, Yu.M.

1987-01-01

Ion-molecular reactions of free butyl cations, generated by nuclear chemical method, with carbon monoxide containing small quantities of ethanol vapors are studied. Carbon monoxide was used to fix instable butyl cations in the form of corresponding acyl ions. Ester of α-methyl-butyric acid appears to be the only product of free butyl cation interaction with carbon monoxide in the presence of ethanol vapors. That means, that up to the moment of butyl cation reaction with carbon monoxide, the primary butyl cations are almost completely isomerized into secondary in agreement with results of previous investigations. This allows one to study free butyl cation isomerization process according to ion-molecular reaction product isomeric composition

Physico-chemical study on guar gum

International Nuclear Information System (INIS)

Mahmoud, Nahla Mubarak

2000-05-01

Guar plant is an annual summer plant and it can resist diseases, pests and drought. Guar gum is used in a lot of industries. The present study deals with some physical properties of two commercial grade samples of guar gum cyamopsis tetragonoloba which where produced in 1996 and 1997 seasons (S 1 and S 2 respectively). Our analytical data are compared with those of previous workers in this area and international quality. Guar gum (S 2 ) is separated into water-insoluble components. Three fractions were obtained from the water-soluble components by fractional participation using acetone. Guar gum powder is yellowish white; the water-insoluble component is brownish white. Comparison study between gum samples (S 1 and S 2 ) and water-insoluble fraction (1) and water-soluble fractions are close to each other in their physico-properties. chemical All samples and fractions contain galactomannan polysaccharide as explained by infra-red spectra.Moisture contents for the gum samples were 5.2% and 7.8% and that for the water-insoluble fraction 4.7% while that for fraction samples were 5.2%-7.5% ash contents for the gum samples was 0.81% and 1.14% and for the water-insoluble component 0.88% while the contents in the fractions between 0.5%-0.66%. Nitrogen content determination showed that the gum samples had value of 0.678% and 0.732% and water -insoluble fraction had a value of 0.118%. The values decreased in the water-soluble fractions giving 0.049%, 0.053 and 0.056%. Water-soluble component and its fractions record the following results: pH measurements showed that the water-soluble component had pH 6.70 and 6.84 while its fractions had pH 5.90 and 7.00. Viscosity measurements showed that water-soluble fractions had intrinsic viscosity of 6.4 and 6.8 dL. g -1 . The fractions derived from water-soluble fraction had intrinsic viscosity of 6.6, 7 and 7.5 dl. g -1 . Using Mark-Howink equation, calculated average molecular weights for the water-soluble components were 7.01x10 5

Characterization of Grewia Gum, a Potential Pharmaceutical Excipient

Directory of Open Access Journals (Sweden)

Elijah.I.Nep

2010-03-01

Full Text Available Grewia gum was extracted from the inner stem bark of Grewia mollis and characterized by several techniques such as gas chromatography (GC, gel permeation chromatography (GPC, scanning electron microscopy (SEM, differential scanning calorimetry (DSC and thermogravimetric analysis of the extracted sample. Spectroscopic techniques such as x-ray photoelectron spectroscopy (XPS, fourier-transformed infrared (FT-IR, solid-state nuclear magnetic resonance (NMR, and 1H and 13C NMR techniques were also used to characterize the gum. The results showed that grewia gum is a typically amorphous polysaccharide gum containing glucose, rhamnose, galactose, arabinose and xylose as neutral sugars. It has an average molecular weight of 5925 kDa expressed as the pullulan equivalent. The gum slowly hydrated in water, dispersing and swelling to form a highly viscous dispersion exhibiting pseudoplastic flow behaviour. The polysaccharide gum is thermally stable and may have application as stabilizer or suspending agent in foods, cosmetics and in pharmaceuticals. It may have application as a binder or sustained-release polymer matrix in tablets or granulations.

Evaluation of carboxymethyl moringa gum as nanometric carrier.

Science.gov (United States)

Rimpy; Abhishek; Ahuja, Munish

2017-10-15

In the present study, carboxymethylation of Moringa oleifera gum was carried out by reacting with monochloroacetic acid. Modified gum was characterised employing Fourier-transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and Rheology study. The carboxymethyl modification of moringa gum was found to increase its degree of crystallinity, reduce viscosity and swelling, increase the surface roughness and render its more anionic. The interaction between carboxymethyl moringa gum and chitosan was optimised by 2-factor, 3-level central composite experimental design to prepare polyelectrolyte nanoparticle using ofloxacin, as a model drug. The optimal calculated parameters were found to be carboxymethyl moringa gum- 0.016% (w/v), chitosan- 0.012% (w/v) which provided polyelectrolyte nanoparticle of average particle size 231nm and zeta potential 28mV. Carboxymethyl moringa gum-chitosan polyelectrolyte nanoparticles show sustained in vitro release of ofloxacin upto 6h which followed first order kinetics with mechanism of release being erosion of polymer matrix. Copyright © 2017 Elsevier Ltd. All rights reserved.

Competition in the gum arabic market: a game theoretic modelling approach

NARCIS (Netherlands)

Rahim, A.; Ierland, van E.C.; Weikard, H.P.

2010-01-01

Gum arabic is mainly produced from two Acacias that are found in the gum belt of Sub-Saharan Africa. These are Acacia senegal that produces high quality gum and Acacia seyal that produces low quality gum. In recent years the gum market structure has changed and Sudan lost its near monopoly position

Gum chewing and cognition : an overview

NARCIS (Netherlands)

Tucha, L.I.; Koerts, J.

In recent years, there was a debate about the effects of gum chewing on various aspects of cognitive functioning. In this review, the results of previous studies are presented and summarized. There is a clear indication that gum chewing can improve various aspects of cognitive functioning including

Grewia Gum 1: Some Mechanical and Swelling Properties of ...

African Journals Online (AJOL)

Erah

Methods: Compacts (500 mg) of both freeze-dried and air-dried grewia gum were separately ... grewia gum films were compared with films of pullulan and guar gum which were similarly prepared. .... Freeze-drying was carried out using an.

gum production by Xanthomonas campestris pv

African Journals Online (AJOL)

DR TONUKARI NYEROVWO

2012-09-11

Sep 11, 2012 ... 8004) for xanthan gum production in this study. ... strain for xanthan gum production using cassava starch in industrial applications. ... the cassava price is cost-effective relative to other ... For amylase activity determination, a crude enzyme sample (1 ml) .... time point to stop fermentation from an economic.

21 CFR 582.7351 - Gum tragacanth.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gum tragacanth. 582.7351 Section 582.7351 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... tragacanth. (a) Product. Tragacanth (gum tragacanth). (b) Conditions of use. This substance is generally...

Neem gum as a binder in a formulated paracetamol tablet with reference to Acacia gum BP.

Science.gov (United States)

Ogunjimi, Abayomi Tolulope; Alebiowu, Gbenga

2014-04-01

This study determined the physical, compressional, and binding properties of neem gum (NMG) obtained from the trunk of Azadirachta indica (A Juss) in a paracetamol tablet formulation in comparison with official Acacia gum BP (ACA). The physical and flow properties were evaluated using density parameters: porosity, Carr's index, Hausner's ratio, and flow rate. Compressional properties were analyzed using Heckel and Kawakita equations. The tensile strength, brittle fracture index, and crushing strength-friability/disintegration time ratio were used to evaluate the mechanical properties of paracetamol tablets while the drug release properties of the tablets were assessed using disintegration time and dissolution times. Tablet formulations containing NMG exhibited faster onset and higher amount of plastic deformation during compression than those containing ACA. Neem gum produced paracetamol tablets with lower mechanical strength; however, the tendency of the tablets to cap or laminate was lower when compared to those containing ACA. Inclusion of NMG improved the balance between binding and disintegration properties of paracetamol tablets produced than those containing ACA. Neem gum produced paracetamol tablets with lower disintegration and dissolution times than those containing ACA.

Brief Report: Gum Chewing Affects Standardized Math Scores in Adolescents

Science.gov (United States)

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

2012-01-01

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

Mango kernel starch-gum composite films: Physical, mechanical and barrier properties.

Science.gov (United States)

Nawab, Anjum; Alam, Feroz; Haq, Muhammad Abdul; Lutfi, Zubala; Hasnain, Abid

2017-05-01

Composite films were developed by the casting method using mango kernel starch (MKS) and guar and xanthan gums. The concentration of both gums ranged from 0% to 30% (w/w of starch; db). Mechanical properties, oxygen permeability (OP), water vapor permeability (WVP), solubility in water and color parameters of composite films were evaluated. The crystallinity and homogeneity between the starch and gums were also evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The scanning electron micrographs showed homogeneous matrix, with no signs of phase separation between the components. XRD analysis demonstrated diminished crystalline peak. Regardless of gum type the tensile strength (TS) of composite films increased with increasing gum concentration while reverse trend was noted for elongation at break (EAB) which found to be decreased with increasing gum concentration. The addition of both guar and xanthan gums increased solubility and WVP of the composite films. However, the OP was found to be lower than that of the control with both gums. Furthermore, addition of both gums led to changes in transparency and opacity of MKS films. Films containing 10% (w/w) xanthan gum showed lower values for solubility, WVP and OP, while film containing 20% guar gum showed good mechanical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Isomeric states in 253No and 253Fm

International Nuclear Information System (INIS)

Antalic, S.; Kalaninova, Z.; Saro, S.; Venhart, M.; Hessberger, F.P.; Ackermann, D.; Heinz, S.; Kindler, B.; Khuyagbaatar, J.; Kojouharov, I.; Kuusiniemi, P.; Lommel, B.; Mann, R.; Sulignano, B.; Hofmann, S.; Leino, M.; Nishio, K.; Streicher, B.

2011-01-01

Nuclear structure and decay of isomeric states in 253 No were investigated. The isotope was produced by the reaction 48 Ca + 207 Pb. The excitation energy of the known single-particle isomeric state (5/2 + [622]) was measured by delayed coincidences between γ-rays and implanted evaporation residues and was placed into the level scheme. In addition, decay of a high-lying multi-quasiparticle isomer in 253 No was studied using e - -γ coincidence measurements. A rotational band populated by its de-excitation was identified in 253 No. A new isomeric state in 253 Fm was observed and a partial-level scheme for this isotope is suggested. In addition γ transitions from excited levels are reported for 253 Md. (orig.)

{sup 13} C-NMR of mesquite gum

Energy Technology Data Exchange (ETDEWEB)

Andrade, Cristina T; Garcia, Rosangela B [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Macromoleculas

1992-12-31

Mesquite and guar gums are galactomannans extracted from the seeds of Proposis Juliflora and Cyamopsis tetragonolobus, respectively. An experimental sample of mesquite gum and a commercial sample of guar gum were partially depolymerized by ultrasonic radiation and the produce analysed by high resolution {sup 13} C-NMR spectroscopy. The different carbon lines were resolved and their assignments were done as those reported in the literature. The galactose to mannose ratios (G/M) were estimated from the relative peak areas of the C-1 lines as G/M=61 for mesquite and G/M=0.54 for guar gum. The next nearest-neighbour probabilities (diad frequencies) of the D-galactosyl substitution to the D-mannose backbone were evaluated by integrating C-4 mannose splitted peaks. (author) 9 refs., 2 figs., 2 tabs.

Xylene isomerization

KAUST Repository

Bilaus, Rakan Sulaiman

2016-06-23

A process for producing xylenes, in particular para-xylene that is less energy intensive than conventional processes is provided. In an embodiment the process comprises contacting a feed mixture in an isomenzation zone with a catalyst at isomenzation conditions and producing an isomerized product comprising a higher proportion of p-xylene than in the feed mixture, wherein the catalyst comprises an acidic sulfonated catalytic membrane. Xylene isomenzation can also be coupled with a p-xylene extraction process, where the raffinate (p-xylene deprived stream) from the extraction process is fed to an isomenzation reactor to produce p-xylene. In an embodiment, the process can comprise: a) providing a feed stream comprising a mixture of xylene isomers including p-xylene; b) extracting p-xylene from the feed stream using a separator to separate the feed stream into a p-xylene rich stream and a p-xylene deprived stream; and c) delivering the p-xylene deprived stream to an isomenzation unit, the isomenzation unit including an acidic sulfonated catalytic membrane, and using the isomenzation unit to produce an isomerized product comprising a higher proportion of p-xylene than in the p-xylene deprived stream delivered to the isomenzation unit. In any one or more aspects, the isomenzation unit can be operated at a temperature in the range of less than 350°, for example about 20°C to about 200°C.

Impact of welan gum on tricalcium aluminate–gypsum hydration

International Nuclear Information System (INIS)

Ma Lei; Zhao Qinglin; Yao Chukang; Zhou Mingkai

2012-01-01

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 3 A was also demonstrated. Thus, through the adsorption effect, welan gum induces a retarding behavior in tricalcium aluminate–gypsum hydration. Highlights: ► Adsorption characteristics of welan gum on C 3 A and ettringite have been studied. ► C 3 A–gypsum hydration behavior and the hydration products are examined in L/S = 3. ► Welan gum retards the process of C 3 A–gypsum hydration. ► The addition of welan gum changes the nucleation growth of ettringite.

Chewing gum and context-dependent memory effects: a re-examination.

Science.gov (United States)

Miles, Christopher; Johnson, Andrew J

2007-03-01

Two experiments re-examined whether chewing spearmint gum affects initial word learning and/or immediate recall for a word list. Both experiments failed to show effects of chewing gum at learning or recall, nor did they suggest that chewing gum produces a context-dependent memory effect. This was true when extraneous contextual cues at learning and recall were minimised (Experiment 2). Together, the data are inconsistent with [Wilkinson, L., Scholey, A. & Wesnes, K. (2002). Chewing gum selectively improves aspects of memory in healthy volunteers. Appetite, 38, 235-236.] claim that chewing gum aids immediate recall of visually presented words. Our results are consistent with [Baker, J. R., Bezance, J. B., Zellaby, E. & Aggleton, J. P. (2004). Chewing gum can produce context-dependent effects upon memory. Appetite, 43, 207-210.] finding that chewing gum of itself is not a sufficient condition to provoke context-dependent learning with immediate testing.

A new fundamental type of conformational isomerism

Science.gov (United States)

Canfield, Peter J.; Blake, Iain M.; Cai, Zheng-Li; Luck, Ian J.; Krausz, Elmars; Kobayashi, Rika; Reimers, Jeffrey R.; Crossley, Maxwell J.

2018-06-01

Isomerism is a fundamental chemical concept, reflecting the fact that the arrangement of atoms in a molecular entity has a profound influence on its chemical and physical properties. Here we describe a previously unclassified fundamental form of conformational isomerism through four resolved stereoisomers of a transoid (BF)O(BF)-quinoxalinoporphyrin. These comprise two pairs of enantiomers that manifest structural relationships not describable within existing IUPAC nomenclature and terminology. They undergo thermal diastereomeric interconversion over a barrier of 104 ± 2 kJ mol-1, which we term `akamptisomerization'. Feasible interconversion processes between conceivable synthesis products and reaction intermediates were mapped out by density functional theory calculations, identifying bond-angle inversion (BAI) at a singly bonded atom as the reaction mechanism. We also introduce the necessary BAI stereodescriptors parvo and amplo. Based on an extended polytope formalism of molecular structure and stereoisomerization, BAI-driven akamptisomerization is shown to be the final fundamental type of conformational isomerization.

Chewing gum differentially affects aspects of attention in healthy subjects.

Science.gov (United States)

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

2004-06-01

In a study published previously in this journal (Wilkinson et al., 2002), the effect of chewing gum on cognitive functioning was examined. The results of this study indicated that chewing a piece of gum results in an improvement of working memory and of both immediate and delayed recall of words but not of attention. In the present study, memory and a variety of attentional functions of healthy adult participants were examined under four different conditions: no chewing, mimicking chewing movements, chewing a piece of tasteless chewing gum and chewing a piece of spearmint flavoured chewing gum. The sequence of conditions was randomised across participants. The results showed that the chewing of gum did not improve participants' memory functions. Furthermore, chewing may differentially affect specific aspects of attention. While sustained attention was improved by the chewing of gum, alertness and flexibility were adversely affected by chewing. In conclusion, claims that the chewing a gum improves cognition should be viewed with caution.

Quantification and Qualification of Bacteria Trapped in Chewed Gum

NARCIS (Netherlands)

Wessel, Stefan W.; van der Mei, Henny C.; Morando, David; Slomp, Anje M.; van de Belt-Gritter, Betsy; Maitra, Amarnath; Busscher, Henk J.

2015-01-01

Chewing of gum contributes to the maintenance of oral health. Many oral diseases, including caries and periodontal disease, are caused by bacteria. However, it is unknown whether chewing of gum can remove bacteria from the oral cavity. Here, we hypothesize that chewing of gum can trap bacteria and

75 FR 44251 - Wood Oils and Gums, and Streptomyces

Science.gov (United States)

2010-07-28

... ENVIRONMENTAL PROTECTION AGENCY EPA-HQ-OPP-2010-0441; FRL-8829-8 Wood Oils and Gums, and... integrated use in tank mixes with chemical fungicides. The Wood Oils and Gums Registration Review Case no longer contains any other wood oils or gums with active ingredients with registered products except for...

Aplikasi Campuran Alginat Dari Sargassum Crassifolium Dan Gum Sebagai Pengental Textile Printing

Directory of Open Access Journals (Sweden)

Subaryono Subaryono

2015-12-01

Full Text Available Penelitian aplikasi campuran alginat dari Sargassum crassifolium dan gum untuk meningkatkan viskositas alginat sebagai pengental pada textile printing telah dilakukan. Viskositas campuran alginat dengan guar gum, gum arab, dan locust bean gum diamati pada penyimpanan selama 8 jam. Produk terbaik diujikan sebagai pengental pada textile printing. Campuran alginat dengan guar gum pada perbandingan 90:10 dan 80:20 meningkatkan viskositas dan stabilitas alginat selama penyimpanan. Campuran alginat dengan gum arab dan locust bean gum akan menurunkan viskositas alginat sehingga tidak sesuai untuk aplikasi textile printing. Aplikasi campuran alginat dengan guar gum 90:10 dan 80:20 sebagai pengental pada tekstil printing menghasilkan produk akhir yang setara dengan pengental komersial manutex.

Gum Arabic authentication and mixture quantification by near infrared spectroscopy

DEFF Research Database (Denmark)

Dong, Yongjiang; Sørensen, Klavs Martin; He, Sailing

2017-01-01

A rapid and reliable method is developed for Gum Arabic authentication based on Near Infrared (NIR) spectroscopy and chemometric methods. On a large industrial collection of authentic gum Arabics, the two major Acacia gum species, Acacia senegal and Acacia seyal could be assigned perfectly...... by the NIR spectroscopic method. In addition, a partial least squares (PLS) regression model is calibrated to predict the blending percentage of the two pure gum types, producing an accuracy, root mean square error of cross validation (RMSECV) of 2.8%. Sampling of the Gum Arabic ‘tears’ is discussed......, and it was determined that subsamples from three ‘tears’ is required for a representative result. It is concluded that NIR spectroscopy is a very powerful and reliable method for authenticity testing of Gum Arabic species....

Masticatory performance alters stress relief effect of gum chewing.

Science.gov (United States)

Nishigawa, Keisuke; Suzuki, Yoshitaka; Matsuka, Yoshizo

2015-10-01

We evaluated the effects of gum chewing on the response to psychological stress induced by a calculation task and investigated the relationship between this response and masticatory performance. Nineteen healthy adult volunteers without dental problems undertook the Uchida-Kraepelin (UK) test (30 min of reiterating additions of one-digit numbers). Before and immediately after the test, saliva samples were collected from the sublingual area of the participants. Three min after the UK test, the participants were made to chew flavorless gum for 3 min, and the final saliva samples were collected 10 min after the UK test. The experiment was performed without gum chewing on a different day. Masticatory performance was evaluated using color-changing chewing gum. Salivary CgA levels at immediately and 10 min after the UK test were compared with and without gum chewing condition. Two-way repeated measures analysis of variance revealed significant interaction between gum chewing condition and changes in CgA levels during post 10 min UK test period. A significant correlation was found between changes in CgA levels and masticatory performance in all participants. Our results indicate that gum chewing may relieve stress responses; however, high masticatory performance is required to achieve this effect. Copyright © 2015 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Analytical studies on the gum exudate from Anogeissus leiocarpus

International Nuclear Information System (INIS)

Ahmed, Samia Eltayeb

1999-04-01

Anogeissus leiocarpus gum samples were collected as natural exudate nodules, from three different location. Physicochemical properties of gum samples were studied. results showed significant differences within each location in most parameters studied except refractive index value which was found to be constant in all samples. The effect of location on the properties of gum samples was also studied and the analysis of variance showed insignificant differences (P≤0.05) in all properties studied except in ash content. Inter nodule variations of gum from two different location were studied individually. Results showed significant differences for each parameter studied except for the refractive index value. The properties studied of all gum samples were as follows: 9.2% moisture, 3.4% ash, 0.72% nitrogen, 4.74% protein, -35.5 specific rotation, 1.68 relative viscosity, 4.2 pH, 1.334 refractive index, 14.3 uronic acid, 0.44% reducing sugar, 1336.0 equivalent weight and 0.68% tannin content. UV absorption spectra of gum samples and gum nodules were determined. Cationic composition of gum samples was also determined and the results showed that (Mg) has highest value in all samples studied followed by Fe, Na, K, Ca, Zn and trace amount of Mn, Co, Ni, Cd and Pb. The water holding capacity was found to be 65.5% and emulsifying stability was found to be 1.008. The component sugars of gum were examined by different methods followed by qualitative and quantitative analysis. Analysis of hydrolysate crude gum sample by HPLC show L-rhamnose (6.82), L-arabinose (48.08), D-galactose (11.26) and two unknown oligosaccharides having values (0.22 and 32.61). Some physicochemical properties were studied. Results showed significant differences in nitrogen and protein contents, specific rotation, relative viscosity, equivalent weight and pH of fractions, where as insignificant differences were observed in uronic acid content and refractive index values

Design, formulation and evaluation of nicotine chewing gum

OpenAIRE

Abolfazl Aslani; Sahar Rafiei

2012-01-01

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...

21 CFR 172.695 - Xanthan gum.

Science.gov (United States)

2010-04-01

.... Record the sample as “negative” for xanthan gum if no gel forms or if a soft or brittle gel forms both... more than 1.5 percent of pyruvic acid and “negative” for xanthan gum if the sample contains less than 1... preclude such use. (f) To assure safe use of the additive: (1) The label of its container shall bear, in...

Granule properties of paracetamol made with Bombax ceiba gum ...

African Journals Online (AJOL)

Bombax ceiba gum was extracted from the calyx of the Bombax flower using both hot and cold water extraction method. The gum was used as binder to prepare paracetamol granules in concentrations of 1, 1.5, 2, and 3 %. Acacia gum was used to prepare the standard at the same concentrations. The granule properties of ...

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

Science.gov (United States)

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

2014-03-01

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.

Gum Graft Surgery

Science.gov (United States)

... Tomography (CBCT) American Academy of Periodontology Installs New President, Officers in Boston American Academy of Periodontology Announces ... May Increase Lung Cancer Risk CDC Estimate: New Mexico, Hawaii Have Highest U.S. Incidence of Advanced Gum ...

Gum Disease Symptoms

Science.gov (United States)

... Tomography (CBCT) American Academy of Periodontology Installs New President, Officers in Boston American Academy of Periodontology Announces ... May Increase Lung Cancer Risk CDC Estimate: New Mexico, Hawaii Have Highest U.S. Incidence of Advanced Gum ...

Gum chewing affects academic performance in adolescents

Science.gov (United States)

Chewing gum may have an impact on improved memory during specific tasks of recognition and sustained attention. Research objective was to determine the effect of gum chewing on standardized test scores and math class grades of eighth grade students. Four math classes, 108 students, were randomized i...

Effects of caffeine in chewing gum on mood and attention.

Science.gov (United States)

Smith, Andrew

2009-04-01

Recent research has shown that even small doses (attention tasks. Previous studies have given the caffeine in a variety of beverages or in capsules and it was of interest to see whether similar effects could be observed when the caffeine was given in gum. In addition, chewing gum has been shown to have behavioural effects and the present study extended our knowledge of this topic. To compare the effects of caffeinated gum (40 mg), placebo gum and no gum conditions on mood and attention. A double blind placebo controlled study was conducted with volunteers being randomly assigned to one of the three conditions. Baseline measures of mood and attention were taken prior to chewing and a test session was then conducted. One hundred and eighteen young adults participated in the study. Caffeinated gum was associated with a more positive mood and better performance on tasks requiring sustained attention. The caffeine improved the speed of encoding of new information which is consistent with previous findings. Chewing placebo gum was also found to be associated with more positive mood, both shortly after chewing and at the end of the study. The implications of the present study are that chewing caffeinated gum has been shown to improve performance efficiency and mood by its alerting and energising effects. The profile of caffeine effects is what one would predict from the existing caffeine literature and such effects may be extremely beneficial in real-life situations. Prior chewing of placebo gum was associated with a more positive mood and this also confirms previous findings.

Isomerization of C[sub 4] alkenes

Science.gov (United States)

Smith, L.A. Jr.

1984-11-13

A method is described for isomerizing isobutene or n-butene to produce a mixture of isobutene and normal butene, and polymerizing at least a portion thereof to produce isobutene/n-butene co-dimer, which comprises feeding at least 80 weight % of either the isobutene or n-butene to a catalytic distillation reactor containing a fixed bed acidic cation exchange resin catalyst packing which provides both the catalyst sites and distillation sites for the reaction products, isomerizing a portion of the isobutene or n-butene to produce a mixture of isobutene and n-butene and reacting at least a portion of the isobutene and n-butene to form co-dimer of isobutene and n-butene, whereby an overhead fraction containing any unreacted isobutene and n-butene and a bottoms fraction containing co-dimer is produced. The result of the reaction is substantially the same regardless whether the feed is isobutene or n-butene. Other aspects of the invention, include combinations of procedures to produce high purity isobutene and n-butene. Either isobutene or n-butene product (depending on the desired product) can be recycled as feed, thus substantially carrying out the isomerization to extinction and total conversion to the desired product. 1 fig.

Evaluation of excitation functions for isomeric levels in neutron reactions

International Nuclear Information System (INIS)

Grudzevich, O.T.; Zelenetskij, A.V.; Zolotarev, K.I.; Kornilov, N.V.; Pashchenko, A.B.

1993-07-01

The authors consider the use of theoretical models to describe experimental excitation functions for isomeric levels in neutron reactions and to predict the cross-sections when no experimental data are available. It is shown that, in many cases, experimental data can be described quite satisfactorily by calculations without adjustment of parameters. For threshold reactions at a neutron energy of ∼ 14 MeV the agreement between calculated and experimental isomeric ratios is ∼ 20%, and is determined mainly by errors in the experimental ratios. However, for some reactions there are considerable differences between experimental and calculated data, which are due, in the authors' opinion, to uncertainties in the schemes of the low-lying levels and of gamma transitions between levels and to the spin dependence of level density. The small isomeric ratio values R<0.1 are described with the lowest accuracy. A formula is suggested for the energy dependence of the isomeric ratio in the (n,γ) reaction. (author)

Glucose Isomerization by Enzymes and Chemo-catalysts: Status and Current Advances

DEFF Research Database (Denmark)

Li, Hu; Yang, Song; Saravanamurugan, Shunmugavel

2017-01-01

of isomerization of aldoses in terms of yields, catalysts, solvents, catalytic systems, etc., by both enzymatic and chemo-catalytic approaches. Among aldose ketose interconversion reactions, fructose production by glucose isomerization to make high-fructose corn syrup (HFCS) is an industrially important and large....../intermediate fructose. This review focuses on how both enzyme and chemo-catalysts are being useful for the isomerization of glucose to fructose. Specifically, development of Lewis acid containing zeolites for glucose isomerization is reviewed in detail, including mechanism, isotopic labeling, and computational studies....... biocatalytic process today, and a large number of studies have been reported on the process development. In parallel, also alternative chemo-catalytic systems have emerged, as enzymatic conversion has drawbacks, though they are typically more selective and produce fructose under mild reaction conditions...

Neem Gum as a Binder in a Formulated Paracetamol Tablet with Reference to Acacia Gum BP

OpenAIRE

Ogunjimi, Abayomi Tolulope; Alebiowu, Gbenga

2014-01-01

This study determined the physical, compressional, and binding properties of neem gum (NMG) obtained from the trunk of Azadirachta indica (A Juss) in a paracetamol tablet formulation in comparison with official Acacia gum BP (ACA). The physical and flow properties were evaluated using density parameters: porosity, Carr’s index, Hausner’s ratio, and flow rate. Compressional properties were analyzed using Heckel and Kawakita equations. The tensile strength, brittle fracture index, and crushing ...

Occurrence of gum spots in black cherry after partial harvest cutting

Science.gov (United States)

Charles O. Rexrode; H. Clay Smith; H. Clay Smith

1990-01-01

Bark beetles, primarily the bark beetle Phlosotribus liminori (Harris), are the major cause of gum spots in sawtimber-size black cherry Prunus serotina Ehrh. Approximately 90 percent of all gum spots in the bole sections are caused by bark beetles. Gum spots were studied in 95 black cherry trees near Parsons, West Virginia. Over 50 percent of the bark beetle-caused gum...

Rapid screening of guar gum using portable Raman spectral identification methods.

Science.gov (United States)

Srivastava, Hirsch K; Wolfgang, Steven; Rodriguez, Jason D

2016-01-25

Guar gum is a well-known inactive ingredient (excipient) used in a variety of oral pharmaceutical dosage forms as a thickener and stabilizer of suspensions and as a binder of powders. It is also widely used as a food ingredient in which case alternatives with similar properties, including chemically similar gums, are readily available. Recent supply shortages and price fluctuations have caused guar gum to come under increasing scrutiny for possible adulteration by substitution of cheaper alternatives. One way that the U.S. FDA is attempting to screen pharmaceutical ingredients at risk for adulteration or substitution is through field-deployable spectroscopic screening. Here we report a comprehensive approach to evaluate two field-deployable Raman methods--spectral correlation and principal component analysis--to differentiate guar gum from other gums. We report a comparison of the sensitivity of the spectroscopic screening methods with current compendial identification tests. The ability of the spectroscopic methods to perform unambiguous identification of guar gum compared to other gums makes them an enhanced surveillance alternative to the current compendial identification tests, which are largely subjective in nature. Our findings indicate that Raman spectral identification methods perform better than compendial identification methods and are able to distinguish guar gum from other gums with 100% accuracy for samples tested by spectral correlation and principal component analysis. Published by Elsevier B.V.

Xanthan gum production by Xanthomonas campestris pv ...

African Journals Online (AJOL)

Cassava starch is a main renewable bio-resource with low price and mass production in Guangxi, China. It was used as carbon source in growing Xanthomonas campestris pv. campestris 8004 (Xcc 8004) for xanthan gum production in this study. The xanthan gum yield of gelatinized cassava starch was higher than that of ...

Design, formulation and evaluation of nicotine chewing gum

Directory of Open Access Journals (Sweden)

Abolfazl Aslani

2012-01-01

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.

High-spin μs isomeric states in 96 Ag

International Nuclear Information System (INIS)

Becerril, A. D.; Lorusso, G.; Amthor, A. M.; Brown, B. A.; Estrade, A.; Guess, C. J.; Hitt, G. W.; Meharchand, R.; Schatz, H.; Smith, K.; Zegers, R. G. T.; Baumann, T.; Bazin, D.; Ginter, T.; Hausmann, M.; Minamisono, K.; Portillo, M.; Stolz, A.; Berryman, J. S.; Crawford, H. L.

2011-01-01

The isomeric and β decays of the N=Z+2 nucleus 96 Ag were investigated at the National Superconducting Cyclotron Laboratory. A cascade of γ-ray transitions originating from the deexcitation of a microsecond isomer was observed for the first time and was found in coincidence with two previously known transitions with energies of 470 and 667 keV. The isomeric half-life was determined as 1.45(7) μs, more precise than previously reported. The existence of a second, longer-lived microsecond isomer, associated with a 743-keV γ transition, is also proposed here. Shell model results within the (p 3/2 p 1/2 f 5/2 g 9/2 ) model space, using the jj44b interaction, reproduced level energies and isomeric decay half-lives reasonably well.

Chewing Gum: Cognitive Performance, Mood, Well-Being, and Associated Physiology

Science.gov (United States)

Allen, Andrew P.; Smith, Andrew P.

2015-01-01

Recent evidence has indicated that chewing gum can enhance attention, as well as promoting well-being and work performance. Four studies (two experiments and two intervention studies) examined the robustness of and mechanisms for these effects. Study 1 investigated the acute effect of gum on mood in the absence of task performance. Study 2 examined the effect of rate and force of chewing on mood and attention performance. Study 3 assessed the effects of chewing gum during one working day on well-being and performance, as well as postwork mood and cognitive performance. In Study 4, performance and well-being were reported throughout the workday and at the end of the day, and heart rate and cortisol were measured. Under experimental conditions, gum was associated with higher alertness regardless of whether performance tasks were completed and altered sustained attention. Rate of chewing and subjective force of chewing did not alter mood but had some limited effects on attention. Chewing gum during the workday was associated with higher productivity and fewer cognitive problems, raised cortisol levels in the morning, and did not affect heart rate. The results emphasise that chewing gum can attenuate reductions in alertness, suggesting that chewing gum enhances worker performance. PMID:26075253

Chewing Gum: Cognitive Performance, Mood, Well-Being, and Associated Physiology

Directory of Open Access Journals (Sweden)

Andrew P. Allen

2015-01-01

Full Text Available Recent evidence has indicated that chewing gum can enhance attention, as well as promoting well-being and work performance. Four studies (two experiments and two intervention studies examined the robustness of and mechanisms for these effects. Study 1 investigated the acute effect of gum on mood in the absence of task performance. Study 2 examined the effect of rate and force of chewing on mood and attention performance. Study 3 assessed the effects of chewing gum during one working day on well-being and performance, as well as postwork mood and cognitive performance. In Study 4, performance and well-being were reported throughout the workday and at the end of the day, and heart rate and cortisol were measured. Under experimental conditions, gum was associated with higher alertness regardless of whether performance tasks were completed and altered sustained attention. Rate of chewing and subjective force of chewing did not alter mood but had some limited effects on attention. Chewing gum during the workday was associated with higher productivity and fewer cognitive problems, raised cortisol levels in the morning, and did not affect heart rate. The results emphasise that chewing gum can attenuate reductions in alertness, suggesting that chewing gum enhances worker performance.

Chewing gum: cognitive performance, mood, well-being, and associated physiology.

Science.gov (United States)

Allen, Andrew P; Smith, Andrew P

2015-01-01

Recent evidence has indicated that chewing gum can enhance attention, as well as promoting well-being and work performance. Four studies (two experiments and two intervention studies) examined the robustness of and mechanisms for these effects. Study 1 investigated the acute effect of gum on mood in the absence of task performance. Study 2 examined the effect of rate and force of chewing on mood and attention performance. Study 3 assessed the effects of chewing gum during one working day on well-being and performance, as well as postwork mood and cognitive performance. In Study 4, performance and well-being were reported throughout the workday and at the end of the day, and heart rate and cortisol were measured. Under experimental conditions, gum was associated with higher alertness regardless of whether performance tasks were completed and altered sustained attention. Rate of chewing and subjective force of chewing did not alter mood but had some limited effects on attention. Chewing gum during the workday was associated with higher productivity and fewer cognitive problems, raised cortisol levels in the morning, and did not affect heart rate. The results emphasise that chewing gum can attenuate reductions in alertness, suggesting that chewing gum enhances worker performance.

Chewing gum benefits sustained attention in the absence of task degradation.

Science.gov (United States)

Johnson, Andrew J; Muneem, Mohammed; Miles, Christopher

2013-07-01

The present study examined the effect of chewing gum on sustained attention and associated changes in subjective alertness. In a within-participants design, 20 participants completed an extended version of the sustained attention response task (SART: Robertson et al., 1997), both with and without chewing gum. Self-rated measures of alertness, contentedness, and calmness were taken before and after the SART. Chewing gum was associated with improved attentional task performance. This finding was not contingent upon a general decrease in attentional performance and was apparent at all stages of the task. Subjective measures of alertness, contentedness, and calmness were higher following the chewing of gum. Changes in sustained attention co-varied with subjective alertness. The effects of chewing gum on attention and alertness are consistent with past literature and were not contingent on declines in attention. Additionally, we found evidence that gum-induced changes in self-rated alertness and attention are related. We found no support for the proposition that chewing gum can impair attention due to the division of resources.

Effect of enzymatic depolymerization on physicochemical and rheological properties of guar gum.

Science.gov (United States)

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

2012-09-01

Depolymerization of guar gum using enzymatic hydrolysis was performed to obtain depolymerized guar gum having functional application as soluble dietary fiber. Enzymatic hydrolysis of guar gum significantly affected the physicochemical and rheological characteristics of guar gum. The depolymerized guar gum showed a significant increase in crystallinity index from 3.86% to 13.2% and flow behavior index from 0.31 to 1.7 as compared to native guar gum. Remarkable decrease in intrinsic viscosity and consistency index was also observed from 9 to 0.28 and 4.04 to 0.07, respectively. Results revealed that enzymatic hydrolysis of guar gum resulted in a polysaccharide with low degree of polymerization, viscosity and consistency which could make it useful for incorporation in food products as dietary fiber without affecting the rheology, consistency and texture of the products. Copyright © 2012 Elsevier Ltd. All rights reserved.

Preparation and characterization of cross-linked excipient of coprocessed xanthan gum-acacia gum as matrix for sustained release tablets

Science.gov (United States)

Surini, Silvia; Wati, Dina Risma; Syahdi, Rezi Riadhi

2018-02-01

Sustained release tablet is solid dosage form which is designed to release drugs slowly in the body. This research was intended to prepare and characterize the cross-linked excipients of co-processed xanthan gum-acacia gum (CL-Co-XGGA) as matrices for sustained release tablets with gliclazide as a model drug. CL-Co-XGGA excipients were cross-linked materials of co-processed excipients of xanthan gum-acacia gum (Co-XGGA) using sodium trimetaphosphate. Co-processed excipients of xanthan gum-acacia gum were prepared in the ratio of each excipient 1:2, 1:1 and 2:1. Co-XGGA and CL-Co-XGGA excipients were characterized physically, chemically and functionally. Then, the sustained release (SR) tablets were formulated by wet granulation method using CL-Co-XGGA excipients as matrices. Also, the dissolution study of the gliclazide SR tablets was carried out in phosphate buffer medium pH 7,4 containing sodium lauryl sulphate 0.2% for 12 hours. The results showed that the degree of substitution (DS) of CL-Co-XGGA 1:2, 1:1, 2:1 excipients were respectively 0.067, 0.082 and 0.08. Besides that, the excipients gel strengths were 14.03, 17.27 and 20,70 gF, respectively. The cross-linked excipients had improved flow properties and swelling capability compared to the Co-XGGA excipients. The results of the gliclazide SR tablets evaluations showed that all tablets were passed all tablet requirements. Moreover, the gliclazide release from SR tablets F1 - F6 revealed the sustained release profile, which was following zero order kinetics (F1, F2, F3, F6) and Higuchi kinetics (F4 and F5). It could be concluded that the obtained CL-Co-XGGA excipients might be used as matrices for sustained release tablets and could retard drug release up to 8 until 32 hours.

Oxidized Xanthan Gum and Chitosan as Natural Adhesives for Cork

Directory of Open Access Journals (Sweden)

Diana Paiva

2016-07-01

Full Text Available Natural cork stopper manufacturing produces a significant amount of cork waste, which is granulated and combined with synthetic glues for use in a wide range of applications. There is a high demand for using biosourced polymers in these composite materials. In this study, xanthan gum (XG and chitosan (CS were investigated as possible natural binders for cork. Xanthan gum was oxidized at two different aldehyde contents as a strategy to improve its water resistance. This modification was studied in detail by 1H and 13C nuclear magnetic resonance (NMR, and the degree of oxidation was determined by the hydroxylamine hydrochloride titration method. The performance of the adhesives was studied by tensile tests and total soluble matter (TSM determinations. Xanthan gum showed no water resistance, contrary to oxidized xanthan gum and chitosan. It is hypothesized that the good performance of oxidized xanthan gum is due to the reaction of aldehyde groups—formed in the oxidation process—with hydroxyl groups on the cork surface during the high temperature drying. Combining oxidized xanthan gum with chitosan did not yield significant improvements.

Xylose Isomerization with Zeolites in a Two-Step Alcohol–Water Process

DEFF Research Database (Denmark)

Paniagua, Marta; Shunmugavel, Saravanamurugan; Melián Rodriguez, Mayra

2015-01-01

Isomerization of xylose to xylulose was efficiently catalyzed by large-pore zeolites in a two-step methanol–water process that enhanced the product yield significantly. The reaction pathway involves xylose isomerization to xylulose, which, in part, subsequently reacts with methanol to form methyl...

Xylitol Chewing Gums on the Market: Do They Prevent Caries?

Science.gov (United States)

Alanzi, Abrar; Soderling, Eva; Varghese, Anisha; Honkala, Eino

To measure the xylitol content in sugar-free chewing gums available on the market in Gulf Cooperation Council (GCC) countries in the Middle East, in order to identify those products that can provide the recommended daily dose of xylitol for caries prevention (6-7 g). Acid production from chewing gums was also measured in vitro and in vivo. Twenty-one chewing gums containing xylitol were identified and collected from the GCC market (Kuwait, Bahrain, Qatar, Saudi Arabia, UAE and Oman). Xylitol was extracted and its concentration was analysed using a special enzymatic kit. The pH of extracts was measured during 30-min incubation with Streptococcus mutans. Changes in saliva and plaque pH were noted in four subjects after the consumption of highly concentrated xylitol gums. The xylitol content in grams was clearly mentioned only on one product's label. Twelve products stated the percentage of xylitol (3.5% to 35%). The rest did not specify the amount. The mean measured weight of one piece of gum was 1.67 ± 0.38 g. The mean measured xylitol content/piece was 0.33 ± 0.21 g. Xylitol content was 0.5 g in 5 products. None of the highly concentrated xylitol gums showed a pH drop in vitro or in vivo. One chewing gum, containing xylitol and glucose, resulted in a low pH level (xylitol chewing gums sold on the GCC market do not provide the consumers with the recommended daily dose of xylitol for caries prevention. Clear, accurate labeling is recommended.

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

Directory of Open Access Journals (Sweden)

Maryam Karami Nogourani

2012-01-01

Full Text Available 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 (<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.

Compatibility of chewing gum excipients with the amino acid L-cysteine and stability of the active substance in directly compressed chewing gum formulation.

Science.gov (United States)

Kartal, Alma; Björkqvist, Mikko; Lehto, Vesa-Pekka; Juppo, Anne Mari; Marvola, Martti; Sivén, Mia

2008-09-01

Using L-cysteine chewing gum to eliminate carcinogenic acetaldehyde in the mouth during smoking has recently been introduced. Besides its efficacy, optimal properties of the gum include stability of the formulation. However, only a limited number of studies exist on the compatibility of chewing gum excipients and stability of gum formulations. In this study we used the solid-state stability method, Fourier transform infrared spectroscopy and isothermal microcalorimetry to investigate the interactions between L-cysteine (as a free base or as a salt) and excipients commonly used in gum. These excipients include xylitol, sorbitol, magnesium stearate, Pharmagum S, Every T Toco and Smily 2 Toco. The influence of temperature and relative humidity during a three-month storage period on gum formulation was also studied. Cysteine alone was stable at 25 degrees C/60% RH and 45 degrees C/75% RH whether stored in open or closed glass ambers. As a component of binary mixtures, cysteine base remained stable at lower temperature and humidity but the salt form was incompatible with all the studied excipients. The results obtained with the different methods corresponded with each other. At high temperature and humidity, excipient incompatibility with both forms of cysteine was obvious. Such sensitivity to heat and humidity during storage was also seen in studies on gum formulations. It was also found that cysteine is sensitive to high pressure and increase in temperature induced by compression. The results suggest that the final product should be well protected from temperature and humidity and, for example, cooling process before compression should be considered.

Chew on this: No support for facilitating effects of gum on spatial task performance.

Science.gov (United States)

Nader, Ingo W; Gittler, Georg; Waldherr, Karin; Pietschnig, Jakob

2010-09-01

To determine whether chewing of gum facilitates spatial task performance in healthy participants, two behavioral experiments were performed. In the first experiment, spatial task performance of 349 men and women preceding and after treatment administration (saccharated chewing gum, sugar-free chewing gum, no chewing gum) was assessed using effect modeling by means of Item Response Theory. In the second experiment, another 100 participants were either administered sugar-free chewing gum or no chewing gum during spatial task performance. Effects of gum in the second study were assessed by standard means of data analysis. Results indicated no significant effects of either chewing gum or sugar on spatial task performance in either experiment. Our findings are consistent with recent studies investigating the influences of chewing gum on various memory functions, extending them by another measure of cognitive ability. Thus, further doubt is cast on enhancing effects of chewing gum on cognitive task performance. Copyright 2010 Elsevier Ltd. All rights reserved.

The development of isomerization catalysts for production of high-octane products

Energy Technology Data Exchange (ETDEWEB)

Pedrosa, A.M. Garrido; Melo, D.M.A.; Araujo, A.S. [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil). Dept. de Quimica; Souza, M.J.B.; Silva, A.O.S. [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil). Dept. de Engenharia Quimica

2004-07-01

In current petroleum industry, paraffins larger than C5 are used for catalytic reform. The catalytic reform is one of the most important processes for petroleum refine in reason of all reactions they drive to production of high-octane products. Reformate has high-octane products, but they contain 60% aromatics. Isomerization of C5- C7 can improve the octane number. The octane number of n-heptane is zero and increases after isomerization. For tri branched C7, the octane number reaches 113, which is higher than that of benzene. So, isomerization of C5-C7 is suggested to be a reasonable way to replace or partly replace the catalytic reforming process. It can decrease aromatics content with enhancement of octane number. Liquid acid catalysts were widely used in chemical industry in past decades. However, they face strong environmental challenges. The heavy corrosion of the reactor system is one of the main problems. Thus, solid acid catalysts are investigated for the isomerization reactions. The aim of this work is to develop a catalysts for the production of reformate products. Isomerization is catalyzed by metal-acid bifunctional catalysts. The metal components aid in hydrogenation, while the support, such as, zirconium, clays or zeolites, is the acidic component. (author)

Cryo-EM structure of isomeric molluscan hemocyanin triggered by viral infection.

Directory of Open Access Journals (Sweden)

Hongtao Zhu

Full Text Available Hemocyanins (Hcs of arthropods and mollusks function not only as oxygen transporters, but also as phenoloxidases (POs. In invertebrates, PO is an important component in the innate immune cascade, where it functions as the initiator of melanin synthesis, a pigment involved in encapsulating and killing of pathogenic microbes. Although structures of Hc from several species of invertebrates have been reported, the structural basis for how PO activity is triggered by structural changes of Hc in vivo remains poorly understood. Here, we report a 6.8 Å cryo-electron microscopy (cryo-EM structure of the isomeric form of hemocyanin, which was isolated from Abalone Shriveling syndrome-associated Virus (AbSV infected abalone (Halitotis diversicolor, and build a pseudoatomic model of isomeric H. diversicolor hemocyanin 1 (HdH1. Our results show that, compared with native form of HdH1, the architecture of isomeric HdH1 turns into a more relaxed form. The interactions between certain functional units (FUs present in the native form of Hc either decreased or were totally abolished in the isomeric form of Hc. As a result of that, native state Hc switches to its isomeric form, enabling it to play its role in innate immune responses against invading pathogens.

Improving gasoline quality produced from MIDOR light naphtha isomerization unit

Directory of Open Access Journals (Sweden)

M.F. Mohamed

2017-03-01

Full Text Available Isomerization process became one of the best gasoline production sources, as it gives a high octane product while saving environment from pollution impacts. This paper presents a practical study that aims to improve the gasoline quality and economic income of an existing light naphtha isomerization unit used for octane improvement. The study included selecting the optimum combination of isomerization unit equipment that gives better product specifications for a specified feed. Eight scenarios were studied and simulated to predict the product specs. The original studied unit is MIDOR light naphtha isomerization unit at Alexandria-Egypt that recycles the unconverted hexane (C6. The other studied scenarios were adding fractionators for separating feed iso-pentanes, and recycling unconverted pentanes, hexanes and/or combinations of these fractionators. The results show a change in octane number of gasoline product for a specific feed. Once through process with no extra fractionators has lower octane number of 81 while that with de-iso-pentanizer–de-pentanizer and de-hexanizer produces gasoline with 92.3 octane number. Detailed economic study was done to calculate the return on investment “ROI” for each process option based on equipment, utilities, feed and product prices. Once through simple isomerization unit had the lowest ROI of 14.3% per year while the combination of De-iso-pentanizer with the De-hexanizer had the best ROI of 26.6% per year.

Isomerization Intermediates In Solution Phase Photochemistry Of Stilbenes

Science.gov (United States)

Doany, F. E.; Hochstrasser, R. M.; Greene, B. I.

1985-04-01

Picosecond and subpicosecond spectroscopic studies have revealed evidence for an isomerization intermediate between cis and trans in the photoinduced isomerism of both stilbene and biindanyledene ("stiff" stilbene). In stiff stilbene, a transient absorption at 351 nm displays time evolution and viscosity dependence consistent with absorption by a twisted intermediate ("phantom" state) with a lOps lifetime. An analagous bottleneck state with a life-time of 4ps is also consistent with the ground state recovery dynamics of t-stilbene following excitation of c-stilbene when monitored with 0.1ps resolution.

cis–trans Isomerization of silybins A and B

Directory of Open Access Journals (Sweden)

Michaela Novotná

2014-05-01

Full Text Available Methods were developed and optimized for the preparation of the 2,3-cis- and the 10,11-cis-isomers of silybin by the Lewis acid catalyzed (BF3∙OEt2 isomerization of silybins A (1a and B (1b (trans-isomers. The absolute configuration of all optically pure compounds was determined by using NMR and comparing their electronic circular dichroism data with model compounds of known absolute configurations. Mechanisms for cis–trans-isomerization of silybin are proposed and supported by quantum mechanical calculations.

Entandophragma angolense Gum as a Novel Binder and ...

African Journals Online (AJOL)

Michael

the development of oral controlled release dosage forms. These semisynthetic polymers are quite expensive when compared with natural polymers such as guar gum and alginates, while the natural polymers are nontoxic and readily available [18]. The present study was designed to evaluate the hydrophilic natural gum ...

Guar gum: processing, properties and food applications—A Review

OpenAIRE

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

2011-01-01

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 movement...

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

Science.gov (United States)

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

2011-12-01

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. 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. 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. Gum flavor can affect the SFR and special flavors may be advised for different individuals according to their oral conditions.

Preparation and characterization of tragacanth-locust bean gum edible blend films.

Science.gov (United States)

Mostafavi, Fatemeh Sadat; Kadkhodaee, Rassoul; Emadzadeh, Bahareh; Koocheki, Arash

2016-03-30

The present work introduces the structure and physicomechanical properties of a novel blend film made from binary solutions of gum tragacanth (GT) and locust bean gum (LBG) at different mixing ratios. Apparent viscosities and surface tensions of individual and blend gum solutions were also investigated. The viscosity data indicated that there was a distinct synergism between the two gums at all mixing ratios. FTIR spectra showed the existence of noncovalent intermolecular interactions between gums. The surface tensions of binary solutions were significantly lower than those of individual gums which is advantageous for coating applications. All films had homogenous and smooth surface morphology and their transparency, water vapour barrier and mechanical properties were improved by incorporating LBG in blend. The results of this study suggest that GT-LBG blend film, owing to its desirable properties, has the potential to be used as a new degradable food packaging material. Copyright © 2015 Elsevier Ltd. All rights reserved.

Modified gum arabic cross-linked gelatin scaffold for biomedical applications

International Nuclear Information System (INIS)

Sarika, P.R.; Cinthya, Kuriakose; Jayakrishnan, A.; Anilkumar, P.R.; James, Nirmala Rachel

2014-01-01

The present work deals with development of modified gum arabic cross-linked gelatin scaffold for cell culture. A new biocompatible scaffold was developed by cross-linking gelatin (Gel) with gum arabic, a polysaccharide. Gum arabic was subjected to periodate oxidation to obtain gum arabic aldehyde (GAA). GAA was reacted with gelatin under appropriate pH to prepare the cross-linked hydrogel. Cross-linking occurred due to Schiff's base reaction between aldehyde groups of oxidized gum arabic and amino groups of gelatin. The scaffold prepared from the hydrogel was characterized by swelling properties, degree of cross-linking, in vitro degradation and scanning electron microscopy (SEM). Cytocompatibility evaluation using L-929 and HepG2 cells confirmed non-cytotoxic and non-adherent nature of the scaffold. These properties are essential for generating multicellular spheroids and hence the scaffold is proposed to be a suitable candidate for spheroid cell culture. - Highlights: • Gum arabic cross-linked gelatin scaffold was developed for tissue engineering. • Cross-linking was achieved by Schiff's base reaction. • The scaffold is non-cytotoxic and non adherent to fibroblast and hepatocytes. • The scaffolds are potential candidates for spheroid cell culture

Modified gum arabic cross-linked gelatin scaffold for biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Sarika, P.R. [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram, Kerala 695 547 (India); Cinthya, Kuriakose [Tissue Culture Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Thiruvananthapuram, Kerala 695 012 (India); Jayakrishnan, A. [Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600 036 (India); Anilkumar, P.R., E-mail: anilkumarpr@sctimst.ac.in [Tissue Culture Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Thiruvananthapuram, Kerala 695 012 (India); James, Nirmala Rachel, E-mail: nirmala@iist.ac.in [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram, Kerala 695 547 (India)

2014-10-01

The present work deals with development of modified gum arabic cross-linked gelatin scaffold for cell culture. A new biocompatible scaffold was developed by cross-linking gelatin (Gel) with gum arabic, a polysaccharide. Gum arabic was subjected to periodate oxidation to obtain gum arabic aldehyde (GAA). GAA was reacted with gelatin under appropriate pH to prepare the cross-linked hydrogel. Cross-linking occurred due to Schiff's base reaction between aldehyde groups of oxidized gum arabic and amino groups of gelatin. The scaffold prepared from the hydrogel was characterized by swelling properties, degree of cross-linking, in vitro degradation and scanning electron microscopy (SEM). Cytocompatibility evaluation using L-929 and HepG2 cells confirmed non-cytotoxic and non-adherent nature of the scaffold. These properties are essential for generating multicellular spheroids and hence the scaffold is proposed to be a suitable candidate for spheroid cell culture. - Highlights: • Gum arabic cross-linked gelatin scaffold was developed for tissue engineering. • Cross-linking was achieved by Schiff's base reaction. • The scaffold is non-cytotoxic and non adherent to fibroblast and hepatocytes. • The scaffolds are potential candidates for spheroid cell culture.

Chewing gum moderates the vigilance decrement.

OpenAIRE

Morgan, K.; Johnson, A.J.; Miles, C..

2014-01-01

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 p...

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

Science.gov (United States)

Barak, Sheweta; Mudgil, Deepak

2014-05-01

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. Copyright © 2014 Elsevier B.V. All rights reserved.

Left cardiac isomerism in the Sonic hedgehog null mouse.

Science.gov (United States)

Hildreth, Victoria; Webb, Sandra; Chaudhry, Bill; Peat, Jonathan D; Phillips, Helen M; Brown, Nigel; Anderson, Robert H; Henderson, Deborah J

2009-06-01

Sonic hedgehog (Shh) is a secreted morphogen necessary for the production of sidedness in the developing embryo. In this study, we describe the morphology of the atrial chambers and atrioventricular junctions of the Shh null mouse heart. We demonstrate that the essential phenotypic feature is isomerism of the left atrial appendages, in combination with an atrioventricular septal defect and a common atrioventricular junction. These malformations are known to be frequent in humans with left isomerism. To confirm the presence of left isomerism, we show that Pitx2c, a recognized determinant of morphological leftness, is expressed in the Shh null mutants on both the right and left sides of the inflow region, and on both sides of the solitary arterial trunk exiting from the heart. It has been established that derivatives of the second heart field expressing Isl1 are asymmetrically distributed in the developing normal heart. We now show that this population is reduced in the hearts from the Shh null mutants, likely contributing to the defects. To distinguish the consequences of reduced contributions from the second heart field from those of left-right patterning disturbance, we disrupted the movement of second heart field cells into the heart by expressing dominant-negative Rho kinase in the population of cells expressing Isl1. This resulted in absence of the vestibular spine, and presence of atrioventricular septal defects closely resembling those seen in the hearts from the Shh null mutants. The primary atrial septum, however, was well formed, and there was no evidence of isomerism of the atrial appendages, suggesting that these features do not relate to disruption of the contributions made by the second heart field. We demonstrate, therefore, that the Shh null mouse is a model of isomerism of the left atrial appendages, and show that the recognized associated malformations found at the venous pole of the heart in the setting of left isomerism are likely to arise from

Remineralization of enamel subsurface lesions by chewing gum with added calcium.

Science.gov (United States)

Cai, Fan; Shen, Peiyan; Walker, Glenn D; Reynolds, Coralie; Yuan, Yi; Reynolds, Eric C

2009-10-01

Chewing sugar-free gum has been shown to promote enamel remineralization. Manufacturers are now adding calcium to the gum in an approach to further promote enamel remineralization. The aim of this study was to compare the remineralization efficacy of four sugar-free chewing gums, two containing added calcium, utilizing a double-blind, randomized, crossover in situ model. The sugar-free gums were: Trident Xtra Care, Orbit Professional, Orbit and Extra. Ten subjects wore removable palatal appliances with four human-enamel half-slab insets containing subsurface demineralized lesions. For four times a day for 14 consecutive days subjects chewed one of the chewing gums for 20min. After each treatment the enamel slabs were removed, paired with their respective demineralized control slabs, embedded, sectioned and mineral level determined by microradiography. After 1-week rest the subjects chewed another of the four gums and this was repeated until each subject had used the four gum products. Chewing with Trident Xtra Care resulted in significantly higher remineralization (20.67+/-1.05%) than chewing with Orbit Professional (12.43+/-0.64%), Orbit (9.27+/-0.59%) or Extra (9.32+/-0.35%). The form of added calcium in Trident Xtra Care was CPP-ACP and that in Orbit Professional calcium carbonate with added citric acid/citrate for increased calcium solubility. Although saliva analysis confirmed release of the citrate and calcium from the Orbit Professional gum the released calcium did not result in increased enamel remineralization over the normal sugar-free gums. These results highlight the importance of calcium ion bioavailability in the remineralization of enamel subsurface lesions in situ.

Tandem ring-closing metathesis/isomerization reactions for the total synthesis of violacein

DEFF Research Database (Denmark)

Petersen, Mette Terp; Nielsen, Thomas Eiland

2013-01-01

A series of 5-substituted 2-pyrrolidinones was synthesized through a one-pot ruthenium alkylidene-catalyzed tandem RCM/isomerization/nucleophilic addition sequence. The intermediates resulting from RCM/isomerization showed reactivity toward electrophiles in aldol condensation reactions which...

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

Science.gov (United States)

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

2001-07-01

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 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.

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

OpenAIRE

Moore, Michael; Hasler-Nguyen, Nathalie; Saroea, Geoffrey

2008-01-01

Abstract Background Extrinsic staining of teeth may result from the deposition of a variety of pigments into or onto the tooth surface, which originate mainly from diet or from tobacco use. More recently, clinical studies have demonstrated the efficacy of some chewing gums in removing extrinsic tooth staining. The aim of this study was to assess the effectiveness of two nicotine medicated chewing gums (A and B) on stain removal in an in vitro experiment, when compared with a confectionary whi...

Effects of chewing gum on mood, learning, memory and performance of an intelligence test.

Science.gov (United States)

Smith, Andrew

2009-04-01

Recent research suggests that chewing gum may increase alertness and lead to changes in cognitive performance. The present study examined effects of chewing gum on these functions within the context of a single study. This study had four main aims. The first was to examine whether chewing gum improved learning and memory of information in a story. The second aim was to determine whether chewing gum improved test performance on a validated intellectual task (the Alice Heim task). A third aim was to determine whether chewing gum improved performance on short memory tasks (immediate and delayed recall of a list of words, delayed recognition memory, retrieval from semantic memory, and a working memory task). The final aim was to determine whether chewing gum improved mood (alertness, calm and hedonic tone). A cross-over design was used with gum and no-gum sessions being on consecutive weeks. In each week, volunteers attended for two sessions, two days apart. The first session assessed mood, immediate recall of information from a story and performance on short memory tasks. The second session assessed mood, delayed recall of information from a story and performance of an intelligence test (the Alice Heim test). There were no significant effects of chewing gum on any aspect of recall of the story. Chewing gum improved the accuracy of performing the Alice Heim test which confirms the benefits of gum on test performance seen in an earlier study. Chewing gum had no significant effect on the short memory tasks. Chewing gum increased alertness at the end of the test session in both parts of the study. This effect was in the region of a 10% increase and was highly significant (P increases alertness. In contrast, no significant effects of chewing gum were observed in the memory tasks. Intellectual performance was improved in the gum condition. Overall, the results suggest further research on the alerting effects of chewing gum and possible improved test performance in these

Gum Disease in Children

Science.gov (United States)

... Club Program Perio Store Education & Careers Careers in Periodontics Perio Exam for Dental Licensure Recommended Competencies Periodontal ... With Find a Periodontist Gum Disease In Children Chronic gingivitis. aggressive periodontitis and generalized aggressive periodontitis are ...

Synthesis, structure and isomerism of three-bridge exo-nido-osmacarborane clusters

International Nuclear Information System (INIS)

Kolomnikova, G.D.; Petrovskij, P.V.; Sorokin, P.V.; Dolgushin, F.M.; Yanovskij, A.I.; Chizhevskij, I.T.

2001-01-01

The structure and isomerism of exo-nido-osmacarboranes prepared by reaction between coordination-unsaturated complex OsCl 2 (PPh 3 ) 3 (Ph-phenyl) in benzene at 20 deg C and K + -salts of nido-dicarbaundecarborate anions were studied by the methods of 1 H and 11 B NMR (including usual and two-dimensional spectra) and X-ray diffraction analysis. It was ascertained that in the compounds prepared osmium-containing group is bound with nido-carborane ligand via three-center bonds, open pentagonal plane of carborane ligand being retained in the isomers. In it nature isomerism in the compounds mentioned is geometrical cis-trans-isomerism [ru

Gum Disease and Women

Science.gov (United States)

... Tomography (CBCT) American Academy of Periodontology Installs New President, Officers in Boston American Academy of Periodontology Announces ... May Increase Lung Cancer Risk CDC Estimate: New Mexico, Hawaii Have Highest U.S. Incidence of Advanced Gum ...

Development of natural gum based fast disintegrating tablets of glipizide

OpenAIRE

Antesh Kumar Jha; Dipak Chetia

2012-01-01

Dysphagia and risk of choking are leading causes of patient non-compliance in the self-administration of conventional tablets. To overcome these limitations of conventional tablets fast-disintegrating tablets were developed, using natural gums. Natural gums were evaluated for bulk swelling capacity. Powder mix containing natural gums and glipizide was evaluated for water sorption, swelling index and capillary action. For faster onset and immediate hypoglycemic action, the fast disintegrating ...

Extraction and characterization of artocarpus integer gum as pharmaceutical excipient.

Science.gov (United States)

Farooq, Uzma; Malviya, Rishabha; Sharma, Pramod Kumar

2014-01-01

Natural polymers are widely used as excipients in pharmaceutical formulations. They are easily available, cheap and less toxic as compared to synthetic polymers. This study involves the extraction and characterization of kathal (Artocarpus integer) gum as a pharmaceutical excipient. Water was used as a solvent for extraction of the natural polymer. Yield was calculated with an aim to evaluate the efficacy of the process. The product was screened for the presence of Micrometric properties, and swelling index, flow behavior, surface tension, and viscosity of natural polymers were calculated. Using a water based extraction method, the yield of gum was found to be 2.85%. Various parameters such as flow behavior, organoleptic properties, surface tension, viscosity, loss on drying, ash value and swelling index together with microscopic studies of particles were done to characterize the extracted gum. The result showed that extracted kathal gum exhibited excellent flow properties. The gum was investigated for purity by carrying out chemical tests for different phytochemical constituents and only carbohydrates were found to be present. It had a good swelling index (13 ± 1). The pH and surface tension of the 1% gum solution were found to be 6 ± 0.5 and 0.0627 J/m2, respectively. The ash values such as total ash, acid insoluble ash, and water soluble ash were found to be 18.9%, 0.67% and 4% respectively. Loss on drying was 6.61%. The extracted gum was soluble in warm water and insoluble in organic solvents. The scanning electron micrograph (SEM) revealed rough and irregular particles of the isolated polymer. The results of the evaluated properties showed that kathal-derived gum has acceptable pH and organoleptic properties and can be used as a pharmaceutical excipient to formulate solid oral dosage forms.

Evaluation of the Binding Effect of Local Gum of Boswellia papyrifera ...

African Journals Online (AJOL)

In this work, B. papyrifera gum has been evaluated for its binding effect in paracetamol granules and tablet formulations in comparison with the commonly used binders, Acacia BP and PVP K-30. Some physicochemical properties of the extracted gum indicated that the gum exhibited solubility in water, absence of tannin and ...

Äppideteemaline vestlusring: lapsed ei lähe enam iga hullusega kaasa / Kristjan Port, Kristi Mäe, Kristi Rahn, Jakob Rosin ; intervjueerinud Madis Aesma

Index Scriptorium Estoniae

2016-01-01

Käib konkurss "Eesti parim mobiilirakendus 2016". Vestlusringis äppidest rääkimas inimesed, kelle jaoks rakendused mängivad igapäevaelus erinevaid rolle - spordibioloog, SA Eesti Antidoping nõukogu liige Kristjan Port, politsei- ja piirivalveameti juhtivkriminaalametnik Kristi Mäe, Gustav Adolfi gümnaasiumi klassiõpetaja Kristi Rahn ja Eesti pimedate liidu juhatuse liige, vaegnägija Jakob Rosin

Effects of chewing gum and time-on-task on alertness and attention.

Science.gov (United States)

Allen, A P; Smith, A P

2012-07-01

Chewing gum has been shown to reliably increase subjective alertness whereas the effects on attention are more variable. It has been suggested that chewing gum only enhances attention when the person has been performing a task for some time. The current research aimed to investigate if time-on-task trends enhancing effects of chewing gum could be observed in alertness and attention during and following chewing. Study 1 used tests of reported mood, including reported mood, and tests of attention (categoric search, focussed attention, simple reaction time, and vigilance). These tasks were performed shortly after the start of chewing. Study 2 examined effects of previous and current chewing on reported alertness and the attention tests. Study 1 showed that chewing gum increased reported alertness and hedonic tone and improved performance on the categoric search task. Chewing gum maintained reported alertness across sessions in study 2. In the first experimental session of study 2 gum improved categoric search performance, and during the second session gum broadened focus of attention and quickened vigilance reaction time. This effect on vigilance reaction time was moderated by time-on-task, with an initial negative effect being replaced by a positive effect. The results confirm the robust effect of chewing gum on reported alertness and show that changes in the effects of chewing gum on attention require further investigation. Future research may also determine underlying mechanisms for an alerting effect.

Thiol derivatization of Xanthan gum and its evaluation as a mucoadhesive polymer.

Science.gov (United States)

Bhatia, Meenakshi; Ahuja, Munish; Mehta, Heena

2015-10-20

Thiol-derivatization of xanthan gum polysaccharide was carried out by esterification with mercaptopropionic acid and thioglycolic acid. Thiol-derivatization was confirmed by Fourier-transformed infra-red spectroscopy. Xanthan-mercaptopropionic acid conjugate and xanthan-thioglycolic acid conjugate were found to possess 432.68mM and 465.02mM of thiol groups as determined by Ellman's method respectively. Comparative evaluation of mucoadhesive property of metronidazole loaded buccal pellets of xanthan and thiolated xanthan gum using chicken buccal pouch membrane revealed higher ex vivo bioadhesion time of thiolated xanthan gum as compared to xanthan gum. Improved mucoadhesive property of thiolated xanthan gum over the xanthan gum can be attributed to the formation of disulfide bond between mucus and thiolated xanthan gum. In vitro release study conducted using phosphate buffer (pH 6.8) revealed a sustained release profile of metronidazole from thiolated xanthan pellets as compared to xanthan pellets. In conclusion, thiolation of xanthan improves its mucoadhesive property and sustained the release of metronidazole over a prolonged period. Copyright © 2015 Elsevier Ltd. All rights reserved.

Xanthan - A Versatile Gum

Indian Academy of Sciences (India)

conveniently from microbial sources due to several factors. They can ... Why do Microorganisms Produce Gums? Most phytopathogenic bacteria do not form spores. Many of .... salts of the polymer at alkaline pH, precipitation as a quarternary.

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

Science.gov (United States)

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

2012-01-01

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 salivary pH. Gum flavored can affect the SFR and pH and special flavors can be advised for different individuals according to their oral conditions.

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

Science.gov (United States)

Stephens, Richard; Tunney, Richard J

2004-10-01

This study tests the hypothesis that chewing gum leads to cognitive benefits through improved delivery of glucose to the brain, by comparing the cognitive performance effects of gum and glucose administered separately and together. Participants completed a battery of cognitive tests in a fully related 2 x 2 design, where one factor was Chewing Gum (gum vs. mint sweet) and the other factor was Glucose Co-administration (consuming a 25 g glucose drink vs. consuming water). For four tests (AVLT Immediate Recall, Digit Span, Spatial Span and Grammatical Transformation), beneficial effects of chewing and glucose were found, supporting the study hypothesis. However, on AVLT Delayed Recall, enhancement due to chewing gum was not paralleled by glucose enhancement, suggesting an alternative mechanism. The glucose delivery model is supported with respect to the cognitive domains: working memory, immediate episodic long-term memory and language-based attention and processing speed. However, some other mechanism is more likely to underlie the facilitatory effect of chewing gum on delayed episodic long-term memory.

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

Science.gov (United States)

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

2012-11-01

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)-κB, 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. Copyright © 2012 John Wiley & Sons, Ltd.

Preparation and characterization of the graft copolymer of chitosan with poly[rosin-(2-acryloyloxy)ethyl ester].

Science.gov (United States)

Duan, Wengui; Chen, Chunhong; Jiang, Linbin; Li, Guang Hua

2008-09-05

Graft copolymerization of rosin-(2-acryloyloxy)ethyl ester (RAEE) onto chitosan (Cts) was carried out under microwave irradiation using potassium persulfate as an initiator. The structures, morphology, and thermal properties of the Cts graft copolymer (Cts-g-PRAEE) were characterized by means of FT-IR, XRD, SEM, and TG. Also, Cts and Cts-g-PRAEE copolymer were used as carriers of fenoprofen calcium (FC), and their controlled release behavior in artificial intestinal juice were studied. The results show that the rate of release of fenoprofen calcium from the carrier of Cts-g-PRAEE copolymer becomes very slower than that of Cts in artificial intestinal juice. Copyright © 2008. Published by Elsevier Ltd.

Fabrication of electrospun almond gum/PVA nanofibers as a thermostable delivery system for vanillin.

Science.gov (United States)

Rezaei, Atefe; Tavanai, Hossein; Nasirpour, Ali

2016-10-01

In this study, the fabrication of vanillin incorporated almond gum/polyvinyl alcohol (PVA) nanofibers through electrospinning has been investigated. Electrospinning of only almond gum was proved impossible. It was found that the aqueous solution of almond gum/PVA (80:20, concentration=7% (w/w)) containing 3% (w/w) vanillin could have successfully electrospun to uniform nanofibers with diameters as low as 77nm. According to the thermal analysis, incorporated vanillin in almond gum/PVA nanofibers showed higher thermal stability than free vanillin, making this composite especially suitable for high temperature applications. XRD and FTIR analyses proved the presence of vanillin in the almond gum/PVA nanofibers. It was also found that vanillin was dispersed as big crystallites in the matrix of almond gum/PVA nanofibers. FTIR analysis showed almond gum and PVA had chemical cross-linking by etheric bonds between COH groups of almond gum and OH groups of PVA. Also, in the nanofibers, there were no major interaction between vanillin and either almond gum or PVA. Copyright © 2016 Elsevier B.V. All rights reserved.

Selective depression behavior of guar gum on talc-type scheelite flotation

Science.gov (United States)

Zhang, Yong-zhong; Gu, Guo-hua; Wu, Xiang-bin; Zhao, Kai-le

2017-08-01

The depression behavior and mechanism of guar gum on talc-type scheelite flotation were systematically investigated by flotation experiments, adsorption tests, zeta-potential measurements, and infrared spectroscopic analyses. The flotation results for monominerals, mixed minerals, and actual mineral samples indicated that guar gum exhibited much higher selective depression for talc than for scheelite. Bench-scale closed-circuit tests showed that a tungsten concentrate with a WO3 grade of 51.43% and a WO3 recovery of 76.18% was obtained. Adsorption tests, zeta-potential measurements, and infrared spectral analyses confirmed that guar gum absorbed more strongly onto the talc surface than onto the scheelite surface because of chemisorption between guar gum and talc. This chemisorption is responsible for the guar gum's highly selective depression for talc and small depression for scheelite. The flotation results provide technical support for talc-type scheelite flotation.

Photochromic ruthenium sulfoxide complexes: evidence for isomerization through a conical intersection.

Science.gov (United States)

McClure, Beth Anne; Mockus, Nicholas V; Butcher, Dennis P; Lutterman, Daniel A; Turro, Claudia; Petersen, Jeffrey L; Rack, Jeffrey J

2009-09-07

The complexes [Ru(bpy)(2)(OS)](PF(6)) and [Ru(bpy)(2)(OSO)](PF(6)), where bpy is 2,2'-bipyridine, OS is 2-methylthiobenzoate, and OSO is 2-methylsulfinylbenzoate, have been studied. The electrochemical and photochemical reactivity of [Ru(bpy)(2)(OSO)](+) is consistent with an isomerization of the bound sulfoxide from S-bonded (S-) to O-bonded (O-) following irradiation or electrochemical oxidation. Charge transfer excitation of [Ru(bpy)(2)(OSO)](+) in MeOH results in the appearance of two new metal-to-ligand charge transfer (MLCT) maxima at 355 and 496 nm, while the peak at 396 nm diminishes in intensity. The isomerization is reversible at room temperature in alcohol or propylene carbonate solution. In the absence of light, solutions of O-[Ru(bpy)(2)(OSO)](+) revert to S-[Ru(bpy)(2)(OSO)](+). Kinetic analysis reveals a biexponential decay with rate constants of 5.66(3) x 10(-4) s(-1) and 3.1(1) x 10(-5) s(-1). Cyclic voltammograms of S-[Ru(bpy)(2)(OSO)](+) are consistent with electron-transfer-triggered isomerization of the sulfoxide. Analysis of these voltammograms reveal E(S)(o)' = 0.86 V and E(O)(o)' = 0.49 V versus Ag/Ag(+) for the S- and O-bonded Ru(3+/2+) couples, respectively, in propylene carbonate. We found k(S-->O) = 0.090(15) s(-1) in propylene carbonate and k(S-->O) = 0.11(3) s(-1) in acetonitrile on Ru(III), which is considerably slower than has been reported for other sulfoxide isomerizations on ruthenium polypyridyl complexes following oxidation. The photoisomerization quantum yield (Phi(S-->O) = 0.45, methanol) is quite large, indicating a rapid excited state isomerization rate constant. The kinetic trace at 500 nm is monoexponential with tau = 150 ps, which is assigned to the excited S-->O isomerization rate. There is no spectroscopic or kinetic evidence for an O-bonded (3)MLCT excited state in the spectral evolution of S-[Ru(bpy)(2)(OSO)](+) to O-[Ru(bpy)(2)(OSO)](+). Thus, isomerization occurs nonadiabatically from an S-bonded (or eta(2

Isomerization of glucose into fructose by environmentally friendly Fe/β zeolite catalysts.

Science.gov (United States)

Xu, Siquan; Zhang, Lei; Xiao, Kehao; Xia, Haian

2017-06-29

Herein, the environmentally friendly Fe/β zeolite for glucose isomerization to fructose in aqueous media was reported for the first time. The effects of various reaction conditions including reaction temperature, reaction time, catalyst dosage, etc. on the isomerization reaction over Fe/β zeolite were studied in detail. Under the optimized conditions, yield of fructose higher than 20% were obtained. Moreover, the Fe/β zeolite catalysts were stable and remained constant catalytic activity after five consecutive runs. The possible active Fe species for isomerization of glucose in Fe/β zeolite is also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

In situ effect of CPP-ACP chewing gum upon erosive enamel loss

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Catarina Ribeiro Barros de ALENCAR

Full Text Available Abstract Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP is able to increase salivary calcium and phosphate levels at an acidic pH. Previous studies demonstrated that a CPP-ACP chewing gum was able to enhance the re-hardening of erosion lesions, but could not diminish enamel hardness loss. Therefore, there is no consensus regarding the effectiveness of CPP-ACP on dental erosion. Objective This in situ study investigated the ability of a CPP-ACP chewing gum in preventing erosive enamel loss. Material and Methods: During three experimental crossover phases (one phase per group of seven days each, eight volunteers wore palatal devices with human enamel blocks. The groups were: GI – Sugar free chewing gum with CPP-ACP; GII – Conventional sugar free chewing gum; and GIII – No chewing gum (control. Erosive challenge was extraorally performed by immersion of the enamel blocks in cola drink (5 min, 4x/day. After each challenge, in groups CPP and No CPP, volunteers chewed one unit of the corresponding chewing gum for 30 minutes. Quantitative analysis of enamel loss was performed by profilometry (µm. Data were analyzed by Repeated-Measures ANOVA and Tukey’s test (p0.05. Conclusion The CPP-ACP chewing gum was not able to enhance the anti-erosive effect of conventional chewing gum against enamel loss.

Evaluation of the suspending properties of Abizia zygia gum on ...

African Journals Online (AJOL)

Purpose: Some excipients are currently available for the formulation of pharmaceutical suspensions. ... Method: The suspending properties of Albizia zygia gum (family ... Characterization tests were carried out on purified Albizia zygia gum.

Deconstructing field-induced ketene isomerization through Lagrangian descriptors.

Science.gov (United States)

Craven, Galen T; Hernandez, Rigoberto

2016-02-07

The time-dependent geometrical separatrices governing state transitions in field-induced ketene isomerization are constructed using the method of Lagrangian descriptors. We obtain the stable and unstable manifolds of time-varying transition states as dynamic phase space objects governing configurational changes when the ketene molecule is subjected to an oscillating electric field. The dynamics of the isomerization reaction are modeled through classical trajectory studies on the Gezelter-Miller potential energy surface and an approximate dipole moment model which is coupled to a time-dependent electric field. We obtain a representation of the reaction geometry, over varying field strengths and oscillation frequencies, by partitioning an initial phase space into basins labeled according to which product state is reached at a given time. The borders between these basins are in agreement with those obtained using Lagrangian descriptors, even in regimes exhibiting chaotic dynamics. Major outcomes of this work are: validation and extension of a transition state theory framework built from Lagrangian descriptors, elaboration of the applicability for this theory to periodically- and aperiodically-driven molecular systems, and prediction of regimes in which isomerization of ketene and its derivatives may be controlled using an external field.

Evidence against memorial facilitation and context-dependent memory effects through the chewing of gum

OpenAIRE

Johnson, A.J.; Miles, C.

2007-01-01

The experiment examined the prediction that chewing gum at learning and/or recall facilitated subsequent word recall. Chewing gum at learning significantly impaired recall, indicating that the chewing of gum has a detrimental impact upon initial word encoding. In addition, a context-dependent memory effect was reported for those participants who both learned and recalled in the absence of gum, however a context dependent effect was not found with chewing gum. The findings contradict previous ...

Effect of guar and xanthan gums on functional properties of mango (Mangifera indica) kernel starch.

Science.gov (United States)

Nawab, Anjum; Alam, Feroz; Haq, Muhammad Abdul; Hasnain, Abid

2016-12-01

The effects of different concentrations of guar and xanthan gums on functional properties of mango kernel starch (MKS) were studied. Both guar and xanthan gum enhanced the water absorption of MKS. The addition of xanthan gum appeared to reduce the SP (swelling power) and solubility at higher temperatures while guar gum significantly enhanced the SP as well as solubility of MKS. The addition of both gums produced a reinforcing effect on peak viscosity of MKS as compared to control. Pasting temperature of MKS was higher than that of starch modified by gums indicating ease of gelatinization. Guar gum played an accelerative effect on setback but xanthan gum delayed the setback phenomenon during the cooling of the starch paste. Both gums were found to be effective in reducing the syneresis while gel firmness was markedly improved. Copyright © 2016 Elsevier B.V. All rights reserved.

Design, formulation, and evaluation of ginger medicated chewing gum

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Abolfazl Aslani

2016-01-01

Conclusion: Ginger chewing gum comprises admissible properties to be used as a modern drug delivery system due to its advantageous results in motion sickness. It passed all the specified tests for an acceptable chewing gum. Thus, it may be successfully produced to help GI problems.

Switching between chewing-gum and no-gum at learning and retrieval does not accentuate error production in free recall

OpenAIRE

Miles, C.; Johnson, A.J.

2010-01-01

Three experiments compared chewing gum to a no gum condition to examine further the finding (Anderson, Berry, Morse & Diotte, 2005) that switching flavour between learning and recall encourages error production independently of free recall. In order to encourage error production, participants in Experiment 1 were told to guess responses at recall, participants in Experiment 2 were required to recall categorised word lists and in Experiment 3 participants repeated the same learning-recall comb...

Influence of different kinds of rosins and hydrogenated resins on the setting time of Grossman cements Influência de diferentes tipos de breus e resinas hidrogenadas sobre o tempo de endurecimento dos cimentos do tipo Grossman

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Manoel Damião SOUSA NETO

1999-01-01

Full Text Available In this study, the effect on the setting time by the addition of different kinds of rosin and hydrogenated resin on the Grossman cement powder was evaluated. The experiments were carried out following the American Dental Association’s specification number 57 for root canal sealers. For this analysis, different Grossman cement powders were prepared using different rosins (X, WW and WG and hydrogenated resins (Staybelite and Staybelite ester 10. The study of the physicochemical properties of the Grossman cements obtained the different kinds of rosins and hydrogenated resins interference on the cement’s setting time. The hydrogenated resin, having a higher pH, increased the setting time of the cement when compared to the X, WW and WG rosins.No presente estudo, analisou-se o efeito da adição de diferentes tipos de breus e resinas hidrogenadas ao pó do cimento de GROSSMAN sobre o tempo de endurecimento. Os experimentos foram realizados de acordo com a Especificação 57 para materiais obturadores de canais radiculares da American Dental Association (ADA. Para análise, foram aviados pós do cimento de GROSSMAN com diferentes tipos de breu (X, WW e WG e resinas hidrogenadas (Stabylite e Stabylite éster 10. Os estudos das propriedades físico-químicas dos cimentos tipo GROSSMAN obtidos de diferentes tipos de breus e resinas hidrogenadas interferem no tempo de endurecimento do cimento. A resina hidrogenada, obtida do processo de hidrogenação tem o pH mais alto, provocando um aumento do tempo de endurecimento do cimento em relação aos breus tipo X, WW e WG, que têm pH mais ácido.

Isomerizations of the Nitromethane Radical Cation in the Gas Phase

DEFF Research Database (Denmark)

Egsgaard, Helge; Carlsen, Lars; Elbel, Susanne

1986-01-01

The concurrent isomerizations of the nitromethane radical cation to its aci-nitromethane and methylnitrite isomers, respectively, has been established based on metastable ion studies and collision activation mass spectrometry. The energy diagram for the ionized nitromethane/aci-nitromethane tauto......The concurrent isomerizations of the nitromethane radical cation to its aci-nitromethane and methylnitrite isomers, respectively, has been established based on metastable ion studies and collision activation mass spectrometry. The energy diagram for the ionized nitromethane...

The potential of dental-protective chewing gum in oral health interventions.

Science.gov (United States)

Ly, Kiet A; Milgrom, Peter; Rothen, Marilynn

2008-05-01

The authors provide an overview of chewing gum as a delivery vehicle for dental-protective agents, highlighting xylitol and its potential application in caries-prevention programs for children. The authors reviewed selected clinical investigations and previous reviews associated with chewing gum containing substances such as calcium, bicarbonate, carbamide, chlorhexidine, fluoride and xylitol and their effects on reducing caries. They searched the MEDLINE database by using the key words "dental caries," "oral health," "calcium," "bicarbonate," "carbamide," "chlorhexidine," "fluoride" and "xylitol." Chewing gum is being used as a delivery vehicle for substances such as calcium, bicarbonate, carbamide, chlorhexidine, fluoride and xylitol to improve oral health and reduce caries. These substances exhibit properties that are protective of the oral environment and mediate common oral diseases. The debate for advocating xylitol use in caries prevention is advancing; however, chewing gum use by young schoolchildren in the United States is hindered by choking hazard concerns and lack of specific xylitol dosing recommendations. The use of chewing gum containing dental-protective substances, particularly xylitol, in caries-prevention programs can reduce the tooth decay epidemic. Chewing gum use by children in the school setting should be reconsidered.

Evidence against memorial facilitation and context-dependent memory effects through the chewing of gum.

Science.gov (United States)

Johnson, Andrew J; Miles, Christopher

2007-05-01

The experiment examined the prediction that chewing gum at learning and/or recall facilitated subsequent word recall. Chewing gum at learning significantly impaired recall, indicating that the chewing of gum has a detrimental impact upon initial word encoding. In addition, a context-dependent memory effect was reported for those participants who both learned and recalled in the absence of gum; however, a context-dependent effect was not found with chewing gum. The findings contradict previous research.

Fluoride and urea chewing gums in an intra-oral experimental caries model

NARCIS (Netherlands)

Sjogren, K; Ruben, J; Lingstrom, P; Lundberg, AB; Birkhed, D

2002-01-01

The aim of the present investigation was to evaluate the effect of sugar-free chewing gums containing fluoride (F) and urea in an intra-oral experimental caries model. Placebo chewing gums (without any active ingredient) and no gum served as controls. Fifteen subjects participated in a cross-over,

Formulation and In vitro Evaluation of Natural Gum-Based ...

African Journals Online (AJOL)

obtained using the blends of natural gum: alginate at total polymer concentration of 2 % w/v using 10 % w/v calcium ... Keywords: Microbeads, Ibuprofen, Natural gums, Sodium alginate, Drug release kinetics. Tropical ... addition, its high cohesiveness which result in ... different chelating agents in order to optimize the.

Chewing Gum: Cognitive Performance, Mood, Well-Being, and Associated Physiology

OpenAIRE

Allen, Andrew P.; Smith, Andrew P.

2015-01-01

Recent evidence has indicated that chewing gum can enhance attention, as well as promoting well-being and work performance. Four studies (two experiments and two intervention studies) examined the robustness of and mechanisms for these effects. Study 1 investigated the acute effect of gum on mood in the absence of task performance. Study 2 examined the effect of rate and force of chewing on mood and attention performance. Study 3 assessed the effects of chewing gum during one working day on w...

Enzymatic depolymerization of gum Tragacanth: Bifidogenic potential of low molecular weight oligosaccharides

DEFF Research Database (Denmark)

Ahmadi Gavlighi, Hassan; Michalak, Malwina; Meyer, Anne S.

2013-01-01

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...... 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 (2 strains), B. longum subsp. infantis (3 strains...... that on galactan (control). HAG3 completely inhibited the growth of the Cl. 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....

Partially hydrolyzed guar gum as a potential prebiotic source.

Science.gov (United States)

Mudgil, Deepak; Barak, Sheweta; Patel, Ami; Shah, Nihir

2018-06-01

Guar galactomannan was enzymatically hydrolyzed to obtain partially hydrolyzed guar gum which can be utilized as prebiotic source. In present study, growth of probiotics (Lactic Acid Bacteria strains) were studied with glucose, partially hydrolyzed guar gum and native guar gum. All the six strains were galactose &/or mannose positive using the API CHl 50 test. Almost all these strains showed an ability to assimilate partially hydrolyzed guar gum with respect to increase in optical density and viable cell count with concomitant decrease in the pH of the growth medium. Streptococcus thermophilus MD2 exhibited higher growth (7.78 log cfu/ml) while P. parvulus AI1 showed comparatively less growth (7.24 log cfu/ml) as compared to used lactobacillus and Weissella strains. Outcomes of the current study suggest that partially hydrolyzed guar can be considered as potential prebiotic compound that may further stimulate the growth of potentially probiotic bacteria or native gut microflora. Copyright © 2018 Elsevier B.V. All rights reserved.

Radiation induced degradation of xanthan gum in aqueous solution

Science.gov (United States)

Hayrabolulu, Hande; Demeter, Maria; Cutrubinis, Mihalis; Güven, Olgun; Şen, Murat

2018-03-01

In our previous study, we have investigated the effect of gamma rays on xanthan gum in the solid state and it was determined that dose rate was an important factor effecting the radiation degradation of xanthan gum. In the present study, in order to provide a better understanding of how ionizing radiation effect xanthan gum, we have investigated the effects of ionizing radiation on aqueous solutions of xanthan at various concentrations (0.5-4%). Xanthan solutions were irradiated with gamma rays in air, at ambient temperature, at different dose rates (0.1-3.3-7.0 kGy/h) and doses (2.5-50 kGy). Change in their molecular weights was followed by size exclusion chromatography (SEC). Chain scission yield (G(S)), and degradation rate constants (k) were calculated. It was determined that, solution concentration was a factor effecting the degradation chemical yield and degradation rate of xanthan gum. Chain scission reactions were more effective for lower solution concentrations.

Thermal decomposition and isomerization of cis-permethrin and beta-cypermethrin in the solid phase.

Science.gov (United States)

González Audino, Paola; Licastro, Susana A; Zerba, Eduardo

2002-02-01

The stability to heart of cis-permethrin and beta-cypermethrin in the solid phase was studied and the decomposition products identified. Samples heated at 210 degrees C in an oven in the dark showed that, in the absence of potassium chlorate (the salt present in smoke-generating formulations of these pyrethroids), cis-permethrin was not isomerized, although in the presence of that salt, decomposition was greater and thermal isomerization occurred. Other salts of the type KXO3 or NaXO3, with X being halogen or nitrogen, also led to a considerable thermal isomerization. Heating the insecticides in solution in the presence of potassium chlorate did not produce isomerization in any of the solvents assayed. Salt-catalysed thermal cis-trans isomerization was also found for other pyrethroids derived from permethrinic or deltamethrinic acid but not for those derived from chrysanthemic acid. The main thermal degradation processes of cis-permethrin and beta-cypermethrin decomposition when potassium chlorate was present were cyclopropane isomerization, ester cleavage and subsequent oxidation of the resulting products. Permethrinic acid, 3-phenoxybenzyle chloride, alcohol, aldehyde and acid were identified in both cases, as well as 3-phenoxybenzyl cyanide from beta-cypermethrin. A similar decomposition pattern occurred after combustion of pyrethroid fumigant formulations.

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

Science.gov (United States)

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

2014-06-22

Research has shown that chewing gum improves attention, although the mechanism for this effect remains unclear. This study investigated the effects and after-effects of chewing gum on vigilance, mood, heart rate and EEG. Participants completed a vigilance task four times; at baseline, with or without chewing gum, and twice post-chewing. EEG alpha and beta power at left frontal and temporal lobes, subjective mood and heart rate were assessed. Chewing gum shortened reaction time and increased the rate of hits, although hits fell during the second post-chewing task. Chewing gum heightened heart rate, but only during chewing. Gum also increased beta power at F7 and T3 immediately post-chewing, but not following the post-chewing tasks. The findings show that chewing gum affects several different indicators of alertness. Copyright © 2014 Elsevier Inc. All rights reserved.

KARAKTERISTIK EMULSI SANTAN DAN MINYAK KEDELAI YANG DITAMBAH GUM ARAB DAN SUKROSA ESTER [Emulsion Characteristics of Coconut Milk and Soybean Oil Added with Gum Arabic and Sucrose Ester

Directory of Open Access Journals (Sweden)

Laksmi Hartayanie

2015-07-01

Full Text Available High saturated fatty acid content in coconut milk can be reduced by adding unsaturated fat. Pretreatment such as pasteurisation, homogenization or stabilizer and emulsifier addition are essential to prevent emulsion deterioration that could happen in few hours. This study aimed to determine the most appropriate combination of gum arabic and sucrose ester to produce good emulsion stability based on its physical and chemical characteristics. Furthermore this study also aimed to determine correlation between creaming index and other characteristics of coconut milk emulsion. Emulsion stability of mixed coconut milk in sterile glass bottles was observed for 7 days under 23-24°C. Stabilizer and emulsifier added were gum arabic and sucrose ester in five combinations, i.e. 6% gum arabic, 0.3% sucrose ester, 6% gum arabic + 0.3% sucrose ester, 3% gum arabic + 0.15% sucrose ester and 4.5% gum arabic + 0.225% sucrose ester. The physical characteristics evaluated were creaming index, total color change, viscosity and droplet distribution, while the chemical characteristics observed included pH, TBA value, and protein content. Data were analyzed by One Way Anova at 95% significant level to determine the differences among treatments. Bivariate Pearson Correlation was used in order to determine the interaction among sample characteristics. The data showed that, gum arabic and sucrose ester can maintain the emulsion stability. A combination of 4.5% gum arabic and 0.225% sucrose ester provided the best physicochemical characteristics with the lowest creaming index and decreased viscosit, and uniform droplet distribution.

Grewia Gum 1: Some Mechanical and Swelling Properties of ...

African Journals Online (AJOL)

Purpose: To study the mechanical and dynamic swelling properties of grewia gum, evaluate its compression behaviour and determine the effect of drying methods on its properties. Methods: Compacts (500 mg) of both freeze-dried and air-dried grewia gum were separately prepared by compression on a potassium bromide ...

Effect of gum hardness on chewing pattern.

Science.gov (United States)

Plesh, O; Bishop, B; McCall, W

1986-06-01

Chewing rhythms are set by a putative central pattern generator whose output is influenced by sensory feedback. In this study we assessed how an altered feedback imposed by changing the hardness of a gum bolus modifies the timing of chewing, the maximal gape, and the activity in the masseter muscle on the chewing side. Ten adult subjects with no orofacial dysfunction chewed a standard piece of soft or hard gum for at least 3 min in random order. Vertical jaw movements were recorded with a kinesiograph and activity of the masseter muscle was recorded and integrated from surface EMG electrodes. The subjects sat in a dental chair and viewed a video lecture to distract their attention from chewing; they were instructed to chew on the right molars. Cycle-by-cycle analysis showed that 9 of the 10 subjects chewed the hard gum more slowly than the soft with no significant change in gape. The increases in cycle duration were due to changes in the duration of the opening and occlusal phases. The duration of closing was not significantly changed even though the duration and level of masseter activity were both significantly increased. We conclude that gum hardness by altering proprioceptive feedback modifies the output of the masticatory central pattern generator in such a way that the temporal aspects of chewing and the output of the masseteric motor pool are affected.

Effect of Teucrium Polium-Containing Chewing Gum on Reducing Salivary Streptococcus Mutans Counts

Directory of Open Access Journals (Sweden)

Somayeh Khoramian Tusi

2018-06-01

Full Text Available Introduction: Several studies have reported the antibacterial effect of Teucrium polium extract. In this study, we sought to determine the effect of a chewing gum containing the aqueous extract of Teucrium polium on the level of salivary Streptococcus mutans. Materials and Methods: In this double-blind clinical trial, 20 dental students were randomly assigned to two groups of intervention and control. The intervention group received a chewing gum containing the aqueous extract of Teucrium polium, and the control group received a chewing gum without any plant extract. Each person chewed the gum for 20 minutes three times a day (after each meal for three weeks. Unstimulated saliva samples were collected at the beginning of the experiment before the use of the gums and one day after the final gum consumption. The quantitative polymerase chain reaction (qPCR technique was employed to determine the bacterial level. The colonization rate of Streptococcus mutans was compared between the two groups by using t-test in SPSS, version 21. Results: There was no significant difference between the two groups in terms of Streptococcus mutans counts before the intervention (P>0.05. The consumption of Teucrium polium extract-containing chewing gum in comparison with the placebo gum significantly diminished the number of Streptococcus mutans colonies (P=0.002. Conclusion: The results of this study showed that the chewing gum containing the aqueous extract of Teucrium polium significantly lowered the colonization rate of Streptococcus mutans in human saliva.

Gum cordia as carrier of antioxidants: effects on lipid oxidation of peanuts.

Science.gov (United States)

Haq, Muhammad Abdul; Azam, Mahmood; Hasnain, Abid

2015-04-01

Performance of antioxidants is improved by incorporating them into polymer matrix such as polysaccharides based edible coatings. Gum cordia, an anionic polysaccharide extracted from the fruits of Cordia.myxa could be used as carrier of antioxidants by virtue of its strong adhering and emulsifying properties. This study aimed to explore the potential of gum cordia as carrier of antioxidants when applied as edible coating on peanuts. Gum Cordia was compared with carboxymethyl cellulose (CMC) in delivering of antioxidants: butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and ascorbic acid (AA). Coated and uncoated peanuts were stored at 35 °C for 126 days and coating carrier effectiveness was measured by following lipid oxidation using chemical parameters (peroxide value and thiobarbituric acid reactive species) and sensory evaluation (oxidized flavor). Significant differences (p cordia was found better than CMC to deliver the antioxidants. Gum cordia based coating in combination with BHA/BHT exhibited highest protection (290 % higher shelf life than control) based on peroxide value (40 meq.O2 kg(-1)) followed by gum codia plus BHT (244 %), gum cordia plus BHA (232 %), CMC plus BHA/BHT (184 %), CMC plus BHA (139 %), CMC plus BHT (119 %), gum cordia plus AA (96 %) and CMC plus AA (46 %).

Effects of chewing gum on cognitive function, mood and physiology in stressed and non-stressed volunteers.

Science.gov (United States)

Smith, Andrew

2010-02-01

Recent research suggests that chewing gum may improve aspects of cognitive function and mood. There is also evidence suggesting that chewing gum reduces stress. It is important, therefore, to examine these two areas and to determine whether contextual factors (chewing habit, type of gum, and personality) modify such effects. The aims of the present study were: (i) to determine whether chewing gum improved mood and mental performance; (ii) to determine whether chewing gum had benefits in stressed individuals; and (iii) to determine whether chewing habit, type of gum and level of anxiety modified the effects of gum. A cross-over study involving 133 volunteers was carried out. Each volunteer carried out a test session when they were chewing gum and without gum, with order of gum conditions counterbalanced across subjects. Baseline sessions were conducted prior to each test session. Approximately half of the volunteers were tested in 75 dBA noise (the stress condition) and the rest in quiet. Volunteers were stratified on chewing habit and anxiety level. Approximately, half of the volunteers were given mint gum and half fruit gum. The volunteers rated their mood at the start and end of each session and had their heart rate monitored over the session. Saliva samples were taken to allow cortisol levels (good indicator of alertness and stress) to be assayed. During the session, volunteers carried out tasks measuring a range of cognitive functions (aspects of memory, selective and sustained attention, psychomotor speed and accuracy). Chewing gum was associated with greater alertness and a more positive mood. Reaction times were quicker in the gum condition, and this effect became bigger as the task became more difficult. Chewing gum also improved selective and sustained attention. Heart rate and cortisol levels were higher when chewing which confirms the alerting effect of chewing gum. Overall, the results suggest that chewing gum produces a number of benefits that are

Extrudates of starch-xanthan gum mixtures as affected by chemical agents and irradiation

International Nuclear Information System (INIS)

Hanna, M.A.; Chinnaswamy, R.; Gray, D.R.; Miladinov, V.D.

1997-01-01

Mixtures of starch, xanthan gum and either polyvinyl alcohol, epichlorohydrin, valeric acid or adipoyl chloride were extruded. Properties of extrudates including apparent viscosity, water solubility, water absorption indices and extrudate expansion were measured for different proportions of xanthan gum, 70% amylose starch (with or without irradiation) and chemical agents. Extrusion with chemical agents and irradiation changed physical properties of both starch and xanthan gum. Expansions of extrudates were higher than that of starch. Viscosity of extrudates increased with xanthan gum concentration. The addition of 1% (w/w) polyvinyl alcohol had the greatest effect of the chemical agents. Irradiation increased the apparent viscosity of starch-xanthan gum mixtures

Excitation functions and isomeric ratios for the isomeric pair sup(106m)Ag and sup(106g)Ag in the 107Ag (d,t) reaction

International Nuclear Information System (INIS)

Lalli, M.E.; Wasilevsky de Lammirato, C.; Herreros, O.R.; Nassiff, S.J.

1976-09-01

Excitation functions and isomeric cross section ratios have been measured for the 107 Ag (d,t), reaction in which the isomeric pair sup(106m/106g)Ag is produced. Thick-target yields have been determined for different irradiation times and as a function of deuteron energy. Stacked silver foils with aluminium foils as monitors were bombarded with deuterons up to 27 MeV and the activities of products measured with a calibrated Ge(Li) counter. (author) [es

Fabrication and characterization of gum Arabic bonded Rhizophora spp. particleboards

International Nuclear Information System (INIS)

Abuarra, Ali; Hashim, Rokiah; Bauk, Sabar; Kandaiya, Sivamany; Tousi, Ehsan Taghizadeh

2014-01-01

Highlights: • Exploring gum Arabic as a binder for Rhizophora sp. particleboards. • The addition of gum Arabic improved overall properties. • Gum Arabic could be added to manufacture particleboards. - Abstract: Gum Arabic (GA) was used as a binder for the fabrication of Rhizophora spp. particleboards. The physical and mechanical properties of the bioadhesive bonded particleboards, including moisture content, internal bond (IB) strength, thickness swelling (TS), water absorption (WA) and field-emission scanning electron microscopy (FESEM) were used to characterize the manufactured particleboards. Three different particle sizes of the Rhizophora spp. with four adhesive levels were utilized. Results revealed that the addition of GA into the particleboards noticeably improved panel overall properties. The GA bonded particleboards resulted in smoother surfaces, more rigid texture and better internal bonding strength compared to binderless particleboards made without using any adhesive. All specimens had internal bond strength of more than the minimum requirement of the Japanese Industrial Standard JIS A-5908 Type-8 of 0.15 N/mm 2 and were noticed to increase by increasing the adhesive level. However the GA bonded particleboards had higher percentage of WA and the TS compared with the binderless boards. Microscopic study also revealed that particleboards bonded with the gum had better contact compared to the binderless boards. Based on these results, it could be concluded that gum Arabic is an effective natural substance that could be added to manufacture particleboards to improve some of panels’ physical and mechanical properties

STUDIES ON SOME PHYSICOCHEMICAL PROPERTIES OF LEUCAENA LEUCOCEPHALA BARK GUM

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Vijetha Pendyala

2010-06-01

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

The impact of chewing gum resistance on immediate free recall.

Science.gov (United States)

Rickman, Sarah; Johnson, Andrew; Miles, Christopher

2013-08-01

Although the facilitative effects of chewing gum on free recall have proved contentious (e.g., Tucha, Mecklinger, Maier, Hammerl, & Lange, 2004; Wilkinson, Scholey, & Wesnes, 2002), there are strong physiological grounds, for example, increased cerebral activity and blood flow following the act of mastication, to suppose facilitation. The present study manipulated resistance to mastication, that is, chewing four pellets versus one pellet of gum, with the assumption that increased resistance will accentuate cerebral activity and blood flow. Additionally, chewing rate was recorded for all participants. In a within-participants design, participants performed a series of immediate free recall tasks while chewing gum at learning (one or four pellets) and recall (one or four pellets). Increased chewing resistance was not associated with increased memory performance, despite consistent chewing rates for both the one and four pellet conditions at both learning and recall. However, a pattern of recall consistent with context-dependent memory was observed. Here, participants who chewed the equivalent number of gum pellets at both learning and recall experienced significantly superior word recall compared to those conditions where the number of gum pellets differed. ©2012 The British Psychological Society.

QbD based synthesis and characterization of polyacrylamide grafted corn fibre gum.

Science.gov (United States)

Singh, Akashdeep; Mangla, Bhumika; Sethi, Sheshank; Kamboj, Sunil; Sharma, Radhika; Rana, Vikas

2017-01-20

The aim of present investigation was to utilize quality by design approach for the synthesis of polyacrylamide corn fibre gum (PAAm-g-CFG) from corn fibre gum (CFG) by varying concentration of acrylamide and initiator. The spectral analysis (ATR-FTIR, 1 H NMR, DSC, X-ray and Mass spectroscopy) was conducted to assure grafting copolymerization of CFG with acrylamide. The powder flow properties confirm the porous nature of PAAm-g-CFG. The grafted copolymer dispersion showed shear thinning behaviour that follows Herschel Bulkley model. The viscoelastic analysis suggested viscous liquid like nature of PAAm-g-CFG and its viscosity increases with increase in concentration of PAAm-g-CFG. The mucoadhesive strength of synthesized PAAm-g-CFG was found to be higher than moringa oleifera gum, karaya gum, guar gum, xanthan gum, chitosan and gelatin. Further, the results pointed toward enhanced thermal stability of PAAm-g-CFG. Thus, PAAm-g-CFG has a great potential to be used in food and pharmaceutical industry. Copyright © 2016 Elsevier Ltd. All rights reserved.

Flavor release measurement from gum model system.

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Ovejero-López, Isabel; Haahr, Anne-Mette; van den Berg, Frans; Bredie, Wender L P

2004-12-29

Flavor release from a mint-flavored chewing gum model system was measured by atmospheric pressure chemical ionization mass spectroscopy (APCI-MS) and sensory time-intensity (TI). A data analysis method for handling the individual curves from both methods is presented. The APCI-MS data are ratio-scaled using the signal from acetone in the breath of subjects. Next, APCI-MS and sensory TI curves are smoothed by low-pass filtering. Principal component analysis of the individual curves is used to display graphically the product differentiation by APCI-MS or TI signals. It is shown that differences in gum composition can be measured by both instrumental and sensory techniques, providing comparable information. The peppermint oil level (0.5-2% w/w) in the gum influenced both the retronasal concentration and the perceived peppermint flavor. The sweeteners' (sorbitol or xylitol) effect is less apparent. Sensory adaptation and sensitivity differences of human perception versus APCI-MS detection might explain the divergence between the two dynamic measurement methods.

Green Synthesis of Carvenone by Montmorillonite-Catalyzed Isomerization of 1,2-Limonene Oxide

DEFF Research Database (Denmark)

Nguyen, Thao-Tran Thi; Chau, Duy-Khiem Nguyen; Duus, Fritz

2013-01-01

Montmorillonite was considered as a good heterogeneous catalyst for the isomerization of 1,2-limonene oxide into car-venone under solvent-free condition. Both conventional heating and green activations were tested in this research. The microwave-assisted isomerization afforded carvenone in high...

Increased gum arabic production after infestation of Acacia senegal ...

African Journals Online (AJOL)

The aim of this study was to investigate the correlation between the beetle Agrilus nubeculosus and gum arabic production by Acacia senegal. Some trees were tapped and left open to facilitate infestation by A. nubeculosus and others were covered with wire mesh as control. Gum yield, physical and chemical properties of ...

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

Science.gov (United States)

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

2012-05-01

Guar gum was hydrolyzed using cellulase from Aspergillus niger at 5.6 pH and 50°C temperature. Hydrolyzed guar gum sample was characterized using Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, dilute solution viscometry and rotational viscometry. Viscometry analysis of native guar gum showed a molecular weight of 889742.06, whereas, after enzymatic hydrolysis, the resultant product had a molecular weight of 7936.5. IR spectral analysis suggests that after enzymatic hydrolysis of guar gum there was no major transformation of functional group. Thermal analysis revealed no major change in thermal behavior of hydrolyzed guar gum. It was shown that partial hydrolysis of guar gum could be achieved by inexpensive and food grade cellulase (Aspergillus niger) having commercial importance and utilization as a functional soluble dietary fiber for food industry. Copyright © 2012 Elsevier B.V. All rights reserved.

Chewing gum benefits sustained attention in the absence of task degradation.

OpenAIRE

Johnson, A.J.; Muneem, M.; Miles, C.

2013-01-01

OBJECTIVES: The present study examined the effect of chewing gum on sustained attention and associated changes in subjective alertness. METHODS: In a within-participants design, 20 participants completed an extended version of the sustained attention response task (SART: Robertson et al., 1997), both with and without chewing gum. Self-rated measures of alertness, contentedness, and calmness were taken before and after the SART. RESULTS: Chewing gum was associated with improved attentional tas...

Tin-containing zeolites are highly active catalysts for the isomerization of glucose in water.

Science.gov (United States)

Moliner, Manuel; Román-Leshkov, Yuriy; Davis, Mark E

2010-04-06

The isomerization of glucose into fructose is a large-scale reaction for the production of high-fructose corn syrup (HFCS; reaction performed by enzyme catalysts) and recently is being considered as an intermediate step in the possible route of biomass to fuels and chemicals. Here, it is shown that a large-pore zeolite that contains tin (Sn-Beta) is able to isomerize glucose to fructose in aqueous media with high activity and selectivity. Specifically, a 10% (wt/wt) glucose solution containing a catalytic amount of Sn-Beta (150 Sn:glucose molar ratio) gives product yields of approximately 46% (wt/wt) glucose, 31% (wt/wt) fructose, and 9% (wt/wt) mannose after 30 min and 12 min of reaction at 383 K and 413 K, respectively. This reactivity is achieved also when a 45 wt% glucose solution is used. The properties of the large-pore zeolite greatly influence the reaction behavior because the reaction does not proceed with a medium-pore zeolite, and the isomerization activity is considerably lower when the metal centers are incorporated in ordered mesoporous silica (MCM-41). The Sn-Beta catalyst can be used for multiple cycles, and the reaction stops when the solid is removed, clearly indicating that the catalysis is occurring heterogeneously. Most importantly, the Sn-Beta catalyst is able to perform the isomerization reaction in highly acidic, aqueous environments with equivalent activity and product distribution as in media without added acid. This enables Sn-Beta to couple isomerizations with other acid-catalyzed reactions, including hydrolysis/isomerization or isomerization/dehydration reaction sequences [starch to fructose and glucose to 5-hydroxymethylfurfural (HMF) demonstrated here].

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

Science.gov (United States)

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

2007-12-01

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

Design, formulation and evaluation of Aloe vera chewing gum

Science.gov (United States)

Aslani, Abolfazl; Ghannadi, Alireza; Raddanipour, Razieh

2015-01-01

Background: Aloe vera has antioxidant, antiinflammatory, healing, antiseptic, anticancer and antidiabetic effects. The aim of the present study was to design and evaluate the formulation of Aloe vera chewing gum with an appropriate taste and quality with the indications for healing oral wounds, such as lichen planus, mouth sores caused by cancer chemotherapy and mouth abscesses as well as reducing mouth dryness caused by chemotherapy. Materials and Methods: In Aloe vera powder, the carbohydrate content was determined according to mannose and phenolic compounds in terms of gallic acid. Aloe vera powder, sugar, liquid glucose, glycerin, sweeteners and different flavors were added to the soft gum bases. In Aloe vera chewing gum formulation, 10% of dried Aloe vera extract entered the gum base. Then the chewing gum was cut into pieces of suitable sizes. Weight uniformity, content uniformity, the organoleptic properties evaluation, releasing the active ingredient in the phosphate buffer (pH, 6.8) and taste evaluation were examined by Latin square method. Results: One gram of Aloe vera powder contained 5.16 ± 0.25 mg/g of phenolic compounds and 104.63 ± 4.72 mg/g of carbohydrates. After making 16 Aloe vera chewing gum formulations, the F16 formulation was selected as the best formulation according to its physicochemical and organoleptic properties. In fact F16 formulation has suitable hardness, lack of adhesion to the tooth and appropriate size and taste; and after 30 min, it released more than 90% of its drug content. Conclusion: After assessments made, the F16 formulation with maltitol, aspartame and sugar sweeteners was selected as the best formulation. Among various flavors used, peppermint flavor which had the most acceptance between consumers was selected. PMID:26605214

Increased gum arabic production after infestation of Acacia senegal ...

African Journals Online (AJOL)

Jane

2011-07-20

Jul 20, 2011 ... chemical properties of gum were determined for infested and control trees. A. senegal infested by A. ... also in the textile, pottery, lithography, cosmetics and ... Deforestation within the gum belt has lead to an increase in desert .... Atomic Absorption = V*N EDTA*1000/Volume of extract (mg/l). Where, V is the ...

Rheological and Quality Characteristics of Taftoon Bread as Affected by Salep and Persian Gums

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M. A. Sahari

2014-01-01

Full Text Available Effects of salep gum at concentrations of 0.5%, 1%, 3%, and 5% (w/w flour basis and the Persian gum at concentrations of 0.5%, 1%, and 3% (w/w flour basis and combination of the two gums at concentrations of 0.5% + 0.5%, 0.75% + 0.25%, and 0.25% + 0.75% on rheological properties of the wheat flour dough and quality of Taftoon bread were studied with regard to retardation of staling. Rheological (farinograph and extensograph characteristics, staling, and organoleptic evaluations were performed on the dough and the resulting Taftoon bread. Statistical results showed that the salep gum at 5% and Persian gum at 3% (w/w flour basis had a significant effect on the dough properties. Salep and Persian gums when each separately added increased and decreased dough water absorption, respectively. Both hydrocolloids increased the dough resistance to extension and decreased its extensibility. Persian gum shows dual nature in water absorption and some other baking properties. Textural studies revealed that addition of 5% salep gum (w/w flour basis reduced the bread crumb firmness and delayed the staling process of the Taftoon bread. X-ray diffraction study also confirmed this result.

Rheological and Quality Characteristics of Taftoon Bread as Affected by Salep and Persian Gums.

Science.gov (United States)

Sahari, M A; Mohammadi, R; Hamidi Esfehani, Z

2014-01-01

Effects of salep gum at concentrations of 0.5%, 1%, 3%, and 5% (w/w flour basis) and the Persian gum at concentrations of 0.5%, 1%, and 3% (w/w flour basis) and combination of the two gums at concentrations of 0.5% + 0.5%, 0.75% + 0.25%, and 0.25% + 0.75% on rheological properties of the wheat flour dough and quality of Taftoon bread were studied with regard to retardation of staling. Rheological (farinograph and extensograph) characteristics, staling, and organoleptic evaluations were performed on the dough and the resulting Taftoon bread. Statistical results showed that the salep gum at 5% and Persian gum at 3% (w/w flour basis) had a significant effect on the dough properties. Salep and Persian gums when each separately added increased and decreased dough water absorption, respectively. Both hydrocolloids increased the dough resistance to extension and decreased its extensibility. Persian gum shows dual nature in water absorption and some other baking properties. Textural studies revealed that addition of 5% salep gum (w/w flour basis) reduced the bread crumb firmness and delayed the staling process of the Taftoon bread. X-ray diffraction study also confirmed this result.

Recent advances in Rosaceae gum exudates: From synthesis to food and non-food applications.

Science.gov (United States)

Bouaziz, Fatma; Koubaa, Mohamed; Ellouz Ghorbel, Raoudha; Ellouz Chaabouni, Semia

2016-05-01

In recent years, great interest has been devoted to the development of new applications for natural gums. These molecules were used for a variety of purposes since they are chemically inert, non-toxic, less expensive, biodegradable and widely available. They represent one of the most abundant raw materials used not only in commercial food products, but also in cosmetic and pharmaceutical products. Plant gums take their advantages compared to other gums (e.g., from animal and microbial sources) mainly because of their acceptance by consumers. Despite of the well description given in literature for the features of plant gum exudates, there is a lack distinguishing the different families that are producing gums, and their potential applications. Among these gums, the ones produced by Rosaceae family (e.g., almond, apricot, cherry, peach, and plum plants) have been taking special attention. Thus, the aim of this review is to report the recent advances in Rosaceae gum exudates. An emphasis is given for the formation mechanisms of these gums, their chemical composition, functional properties and structures, beneficial properties, as well as their food/non-food applications. Copyright © 2016 Elsevier B.V. All rights reserved.

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

International Nuclear Information System (INIS)

Singh, Baljit; Sharma, Vikrant

2013-01-01

Keeping in view the influence of gamma radiation on the physiochemical properties of the polysaccharides and their importance in the food and pharmaceutical industry, in the present study attempt has been made to investigate the effects of absorbed dose on FTIR, XRD, SEMs, absorbance, pH, solubility, water absorption capacity, emulsion stability and rheology of sterculia gum. Increase in solubility and decrease in swellability of gum has been observed on increasing the absorbed dose. The emulsion stability has improved for the gum sample irradiated with total dose of 8.1±0.2 kGy. Apparent viscosity of gum solution first increased with increase in dose from 0 to 8.1±0.2 kGy than decreased with regular trends with further increase in total absorbed dose. Flow behavior of gum solution shifted to Newtonian from non-Newtonian with increasing the dose. - Highlights: • Solubility increased and swellability decreased of gum on increasing the total dose. • Apparent viscosity of gum solution increased upto 8.1 kGy then decreased. • Emulsion stability improved for gum irradiated with total dose of 8.1 kGy. • Flow behavior shifted to Newtonian from non-Newtonian with increasing total dose

Gum acacia coating with garlic and cinnamon as an alternate ...

African Journals Online (AJOL)

Madhumita

The antibacterial activity of gum arabic coating with ... Key words: Gum acacia coating, garlic, cinnamon, antioxidant, antimicrobial, meat, ... cinnamaldehyde and eugenol inhibit production of an ... antioxidant activity because these two properties are ... temperatures .... activity of these spices but no report on its application.

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

Science.gov (United States)

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

2013-10-15

Guar gum is a galactomannan extracted from the seed of the leguminous shrub Cyamopsis tetragonoloba. It was found to form a soft viscoelastic gel in 1-butyl-3-methylimidazolium chloride, an ionic liquid at an optimized concentration of 10%w/v. A nanocomposite gel of the gum with enhanced strength could be prepared with 0.2%w/v of multiwalled carbon nanotubes (MWCNTs) in the ionic liquid. When the gels thus prepared were subjected to surface fractures or bisected completely, they found to self-heal at room temperature without any external interventions. The self-healing process could be repeated several times. These viscoelastic gel systems showed thixotropic nature and recovery of the storage modulus with time for several cycles was observed upon rheological investigations. The interaction took place between ionic liquid, guar gum and MWCNT was studied by SEM, TEM, FT-IR, powder XRD and rheometry. The results suggested that, upon standing at room temperature development of electrostatic interactions and the van der Waals interactions among the ionic liquid molecules facilitated the formation of reversible noncovalent bonds and eventually activated the self-healing in the gel systems through appropriate chain entanglements. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

Ahuja, Munish; Kumar, Suresh; Kumar, Ashok

2013-04-01

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. Copyright © 2012 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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

2012-06-01

An intervention study was carried out to examine the effects of chewing gum on occupational stress and related outcomes. 101 volunteers from Cardiff University completed the study. The results showed that chewing gum reduced stress (both at work and outside work), reduced fatigue, reduced anxiety and depression and led to a more positive mood. Chewing gum was also associated with perceptions of better performance (both at work and outside). Copyright © 2012 Elsevier Ltd. All rights reserved.

Gum chewing improves swallow frequency and latency in Parkinson patients: a preliminary study.

Science.gov (United States)

South, Angela R; Somers, Stephanie M; Jog, Mandar S

2010-04-13

Reduced swallowing frequency affects secretion management in Parkinson disease (PD). Gum chewing increases saliva flow and swallow frequency. This study uses chewing gum to modify swallow frequency and latency between swallows in patients with PD. 1) Assess the frequency and latency of swallow at baseline (BL), during gum chewing (GC), and post gum chewing (PGC) for participants with PD (stage 2-4) nonsymptomatic for prandial dysphagia; and 2) assess carryover after gum is expectorated. Twenty participants were studied across 3 tasks, each of 5 minutes in duration: BL, GC, and PGC. Respiratory and laryngeal signals were continuously recorded using PowerLab (version 5.5.5; ADI Instruments, Castle Hill, Australia). Frequency and latency of swallow events were calculated. Differences (analysis of variance) are reported for frequency (p Parkinson disease. This study provides Class III evidence that chewing gum increases swallow frequency and decreases latency of swallowing in an experiment in patients with stage 2 to 4 Parkinson disease who are nonsymptomatic for significant prandial dysphagia.

Increased gum arabic production after infestation of Acacia senegal ...

African Journals Online (AJOL)

Jane

2011-07-20

Jul 20, 2011 ... Despite the fact that gum arabic is widely used as a vehicle for .... humidity, are the main factors affecting gum arabic yield. ... 450 mm from May to October; the soil is uniform deep reddish sand with little textural differentiation in the profile. .... 0.01; Mg/l * equivalent weight = mg/l (ppm); Molecular weight *.

Intrinsic viscosity of guar gum in sweeteners solutions | Samavati ...

African Journals Online (AJOL)

Rheological methods were applied to study the effect of sweeteners on the rheological behavior of guar gum in dilute solutions. The concentration of the sweeteners were 0.1, 0.2%w/v for aspartame, acesulfame-k and cyclamate, and 0.001, 0.002%w/v for neotame. Gum was evaluated for intrinsic viscosity by various ...

Trimethylphosphide isomerization in lanthanum ions presence

International Nuclear Information System (INIS)

Zacharias, M.A.; Massabni, A.M.G.

1984-01-01

The integration between the trimethilphosphide and the lanthanum ions carry to the formation of solid complexes in a relation of 6:1 where the ligand is the phosphonate what is resultant of the isomerization of trimetylphosphite. By the RMN -1 H and infra-red spectra the products were characterized. (L.M.J.) [pt

Gum in apricot (Prunus armeniaca L. shoots induced by methyl jasmonate

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Marian Saniewski

2013-12-01

Full Text Available It has been well known that some fungal pathogens (Monilia laxa, M. fructigena, Cytospora cincta, larvae of Grapholita molesta and plant hormone - ethylene, induce gummosis in apricot shoots. Methyl jasmonate (JA-Me was also found to induce gummosis in apricot shoots as well as biotic and abiotic factors mentioned above. In order to know the mode of action of JA-Me on gum induction and/or formation, chemical composition of polysaccharides (after hydrolysis in gums of apricot shoots induced by JA-Me compared with those by ethephon and their mixture, and naturally occurring ones was studied, resulted in the succesful identification of monosaccharides, and the similarity of a composition consisting of xylose, arabinose and galactose at molar ratio 1:10:14, respectively. These results suggest that beside different inducers of gum in apricot the mechanism of polysaccharides biosynthesis of gums is the same or similar. The physiological role for JA-Me on gum induction and/or formation in apricot shoots, and other species are also discussed.

Consequences of acid strength for isomerization and elimination catalysis on solid acids.

Science.gov (United States)

Macht, Josef; Carr, Robert T; Iglesia, Enrique

2009-05-13

We address here the manner in which acid catalysis senses the strength of solid acids. Acid strengths for Keggin polyoxometalate (POM) clusters and zeolites, chosen because of their accurately known structures, are described rigorously by their deprotonation energies (DPE). Mechanistic interpretations of the measured dynamics of alkane isomerization and alkanol dehydration are used to obtain rate and equilibrium constants and energies for intermediates and transition states and to relate them to acid strength. n-Hexane isomerization rates were limited by isomerization of alkoxide intermediates on bifunctional metal-acid mixtures designed to maintain alkane-alkene equilibrium. Isomerization rate constants were normalized by the number of accessible protons, measured by titration with 2,6-di-tert-butylpyridine during catalysis. Equilibrium constants for alkoxides formed by protonation of n-hexene increased slightly with deprotonation energies (DPE), while isomerization rate constants decreased and activation barriers increased with increasing DPE, as also shown for alkanol dehydration reactions. These trends are consistent with thermochemical analyses of the transition states involved in isomerization and elimination steps. For all reactions, barriers increased by less than the concomitant increase in DPE upon changes in composition, because electrostatic stabilization of ion-pairs at the relevant transition states becomes more effective for weaker acids, as a result of their higher charge density at the anionic conjugate base. Alkoxide isomerization barriers were more sensitive to DPE than for elimination from H-bonded alkanols, the step that limits 2-butanol and 1-butanol dehydration rates; the latter two reactions showed similar DPE sensitivities, despite significant differences in their rates and activation barriers, indicating that slower reactions are not necessarily more sensitive to acid strength, but instead reflect the involvement of more unstable organic

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

Science.gov (United States)

Demirci, Zeynep Ozben; Yılmaz, Ismail; Demirci, Ahmet Şukru

2014-05-01

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 meatball samples formulated with 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.

Study of the nanostructure of Gum Metal using energy-filtered transmission electron microscopy

International Nuclear Information System (INIS)

Yano, T.; Murakami, Y.; Shindo, D.; Kuramoto, S.

2009-01-01

The nanostructure of Gum Metal, which has many anomalous mechanical properties, was investigated using transmission electron microscopy with energy filtering. A precise analysis of the weak diffuse electron scattering that was observed in the electron diffraction patterns of the Gum Metal specimen revealed that Gum Metal contains a substantial amount of the nanometer-sized ω phase. The morphology of the ω phase appeared to have a correlation with the faulting in the {2 1 1} planes, which are one of the characteristic lattice imperfections of the Gum Metal specimen. It is likely that the nanometer-sized ω phase may be a type of obstacle related to the restriction of the dislocation movement, which has been a significant problem in research on Gum Metal

Gum Disease by the Numbers | NIH MedlinePlus the Magazine

Science.gov (United States)

... us Gum Disease by the Numbers Gum (or periodontal) disease is one of the leading threats to dental health. It's typically caused by poor brushing and flossing habits that allow plaque—a sticky film of bacteria—to build up on teeth and harden. In ...

Stability and isomerization reactions of phenyl cation C{sub 6}H{sub 5}{sup +} isomers

Energy Technology Data Exchange (ETDEWEB)

Shi, Dandan [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun 130012 (China); Yang, Xue [College of Science, Jilin Institute of Chemical Technology, Jilin 132022 (China); Zhang, Xiaomei; Shan, Shimin [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun 130012 (China); Xu, Haifeng, E-mail: xuhf@jlu.edu.cn [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun 130012 (China); Yan, Bing, E-mail: yanbing@jlu.edu.cn [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun 130012 (China)

2016-03-01

Highlights: • A total of 60 isomers of C{sub 6}H{sub 5}{sup +} cations were obtained at density functional theory. • The stability and isomerization reactions of C{sub 6}H{sub 5}{sup +} isomers were performed. • The structures, frequencies, thermodynamic properties of isomers were summarized. • Ring to ring or chain isomerization pathways were investigated using IRC method. • Result shows reactions contain hydrogen transfer, bond broken and reconstruction. - Abstract: As a key polyatomic molecular cation that plays a pivotal role in growth of the polycyclic aromatic hydrocarbons, phenyl cation C{sub 6}H{sub 5}{sup +} exhibits various isomers and isomerization reactions. Investigation on the structure and stability of the isomers as well as the isomerization is important for better understanding the chemical reactions involving C{sub 6}H{sub 5}{sup +} cations. In this work, we have performed a theoretical study on the stability and isomerization reactions of C{sub 6}H{sub 5}{sup +} isomers at density functional theory B3LYP/6-311G (d, p) level. We have obtained a total of 60 isomers of C{sub 6}H{sub 5}{sup +} cations, most of which are reported for the first time. The geometries, vibrational frequencies, thermodynamic properties and stability of 28 out of 60 isomers have been summarized in detail. Different ring-to-ring and ring-to-chain isomerization pathways, which are connected via 28 transition states, have been investigated using the intrinsic reaction coordinate method. The results show that the isomerization reactions occur via hydrogen migration followed by bond-breaking and reconstruction.

Relative bioavailability of methadone hydrochloride administered in chewing gum and tablets

DEFF Research Database (Denmark)

Christrup, Lona Louring; Angelo, H.R.; Bonde, J.

1990-01-01

Methadone administered in chewing gum in doses of 16.7-22.6 mg to seven patients in a study using an open balanced cross-over design, was compared with 20 mg of methadone given perorally as tablets. There was no significant difference in the AUC/D obtained after administration of chewing gum...... and tablets (p>0.05). It is concluded that the chewing gum formulation should be considered for further testing with respect to suppression of abstinence syndrome in narcotic addicts....

Relative bioavailability of methadone hydrochloride administered in chewing gum and tablets.

Science.gov (United States)

Christrup, L L; Angelo, H R; Bonde, J; Kristensen, F; Rasmussen, S N

1990-01-01

Methadone administered in chewing gum in doses of 16.7-22.6 mg to seven patients in a study using an open balanced cross-over design, was compared with 20 mg of methadone given perorally as tablets. There was no significant difference in the AUC/D obtained after administration of chewing gum and tablets (p greater than 0.05). It is concluded that the chewing gum formulation should be considered for further testing with respect to suppression of abstinence syndrome in narcotic addicts.

Dehydrogenation and concurrent isomerization of n-butenes on mixed tin and antimony oxide catalysts

Energy Technology Data Exchange (ETDEWEB)

Irvine, E.A.; Taylor, D.

1978-01-01

The dehydrogenation and concurrent isomerization of n-butenes on mixed tin and antimony oxide catalysts which had been outgassed at 698/sup 0/K were carried out in the presence of oxygen at 474/sup 0/K, and the initial approximately zero-order rates of 1,3-butadiene formation and rates of isomerization were used as a measure of catalytic activity to construct activity patterns as a function of catalyst composition. A comparison of the patterns with those for the isomerization of 3,3-dimethyl-1-butene and for the selective oxidation of propane on the same catalysts indicated that the dehydrogenation of 1-butene involves a m-allyl intermediate, but isomerization occurs through carbonium ion formation. For the cis- and trans-isomers, both reactions apparently occurred via a common allyl (but not m-allyl) intermediate. Dehydrogenation to butadiene decreased in the order 1-butene > cis-2-butene trans-2-butene and was maximum at 10% antimony for 1-butene and 21% antimony for 2-butene. Isomerization was always slower than dehydrogenation and showed two maEima, at 21 (or 27%) and at 75% antimony.

Crystal structure of isomeric boron difluoride acetylnaphtholates

International Nuclear Information System (INIS)

Bukvetskij, B.V.; Fedorenko, E.V.; Mirochnik, A.G.; Karasev, V.E.

2006-01-01

Crystal structures of luminescent isomeric acetylnaphtholates of boron difluoride are investigated. Full X-ray structural analysis is done at 293 K. Coordinated of atoms, bond angles, bond lengths, interatomic distances are determined. Results of comparative evaluations of the isomers are represented [ru

Evaluation of isomeric excitation functions in neutron induced reactions

International Nuclear Information System (INIS)

Grudzevich, O.; Ignatyuk, A.; Zolotarev, K.

1992-01-01

The possibilities of isomer levels experimental excitation functions description with theoretical models are discussed. It is shown that the experimental data in many cases can be described by theoretical models quite well without parameter fitting. However, large discrepancies are observed for some reactions. In our opinion, these discrepancies are due to uncertainties of discrete level schemes, schemes of gamma-transitions between levels and spin dependence of level density. Small values of isomeric ratios (< 0.1) have been described with the largest errors. The simple formulae for energy dependence of isomeric ratio for (n,g) reaction has been proposed. (author). 53 refs, 10 figs, 8 tabs

Physicochemical and functional parameters of Cochlospermum vitifolium (bototo gum exudate

Directory of Open Access Journals (Sweden)

Maritza Coromoto Martínez

2016-12-01

Full Text Available The physicochemical parameters of Cochlospermum vitifolium they were evaluated and were linked to certain functional properties of industrial interest. The physicochemical parameters were determined by the classic methodology used for carbohydrates and the functional properties, as reported in the literature. The results obtained showed that the gum object of this study is low soluble in water, which corresponds with relatively high values of swelling indexes and water absorption capacity. Also, the intrinsic viscosity of the C. vitifolium exudate was related to a high molar mass, in the order of 106. Its emulsifying capacity is high, which is attributed to hydrophobic groups present in its structure. The gum gels at a minimum concentration, similar to that of the gum karaya (4.5%, but the gel that forms agglomerates, it is not uniform. The C. vitifolium gum exhibits important physicochemical and functional parameters which could serve as a criterion for testing its use in various industries.

Control of structural isomerism in noncovalent hydrogen-bonded assemblies using peripheral chiral information

NARCIS (Netherlands)

Prins, L.J.; Jolliffe, K.A.; Hulst, A.J.R.L.; Timmerman, P.; Reinhoudt, David

2000-01-01

The results of a systematic study of the structural isomerism in more than 30 noncovalent hydrogen-bonded assemblies are described. These dynamic assemblies, composed of three calix[4]arene dimelamines and six barbiturates/cyanurates, can be present in three isomeric forms with either D3, C3h, or Cs

Gum from the bark of Anogeissius leiocarpus as a potential ...

African Journals Online (AJOL)

Gum from the bark of Anogeissius leiocarpusas a potential pharmaceutical raw material – granule properties. Philip F Builders, Olubayo O Kunle, Yetunde C Isimi. Abstract. With the continuous effort to discover and produce cheap but high quality excipients for drug production Anogeissius leiocarpus gum (ALG), a brownish ...

Vegetation status and socio-economic importance of gum and resin ...

African Journals Online (AJOL)

Ethiopian Journal of Biological Sciences ... Abstract. Study on population status, socio-economic importance and threats of gum- and resin-producing plant species was made in Borena, South Wollo, (Ethiopia). ... A total of 14 gum- and resin-bearing plant species representing seven families were recorded. Five of them ...

Development of controlled release spheroids using Buchananiacochinchinesis gum

Directory of Open Access Journals (Sweden)

Narayan Babulal Gaikwad

2013-03-01

Full Text Available Chirauli nut gum was isolated from the bark of Buchanania cochinchinesis (fam. Anacadiacea and was used as a release modifier for the preparation of Diclofenac sodium spheroids using the extrusion spheronization technique. The process was studied for the effects on variables when making spheroids with satisfactory particle shape, size and size distribution. The prepared spheroids were characterized for surface morphology, qualitative surface porosity, friability, bulk density and flow properties. In vitro studies demonstrated that the release exhibited Fickian diffusion kinetics which was confirmed by the Higuchi and the Korsmeyer-Peppas models. The physico-chemical parameters of the gum could be correlated to the in vitro dissolution profile of the spheroids. The spheroids were not able to sustain the drug releases over 12 hours. A greater concentration of Chirauli nut gum and a process that can accommodate such greater concentrations may produce a formulation capable of significant sustained release.

Influence of gas injection on viscous and viscoelastic properties of Xanthan gum.

Science.gov (United States)

Bobade, Veena; Cheetham, Madalyn; Hashim, Jamal; Eshtiaghi, Nicky

2018-05-01

Xanthan gum is widely used as a model fluid for sludge to mimic the rheological behaviour under various conditions including impact of gas injection in sludge. However, there is no study to show the influence of gas injection on rheological properties of xanthan gum specifically at the concentrations at which it is used as a model fluid for sludge with solids concentration above 2%. In this paper, the rheological properties of aqueous xanthan gum solutions at different concentrations were measured over a range of gas injection flow rates. The effect of gas injection on both the flow and viscoelastic behaviour of Xanthan gum (using two different methods - a creep test and a time sweep test) was evaluated. The viscosity curve of different solid concentrations of digested sludge and waste activated sludge were compared with different solid concentrations of Xanthan gum and the results showed that Xanthan gum can mimic the flow behaviour of sludge in flow regime. The results in linear viscoelastic regime showed that increasing gas flow rate increases storage modulus (G'), indicating an increase in the intermolecular associations within the material structure leading to an increase in material strength and solid behaviour. Similarly, in creep test an increase in the gas flow rate decreased strain%, signifying that the material has become more resistant to flow. Both observed behaviour is opposite to what occurs in sludge under similar conditions. The results of both the creep test and the time sweep test indicated that choosing Xanthan gum aqueous solution as a transparent model fluid for sludge in viscoelastic regime under similar conditions involving gas injection in a concentration range studied is not feasible. However Xanthan gum can be used as a model material for sludge in flow regime; because it shows a similar behaviour to sludge. Copyright © 2018 Elsevier Ltd. All rights reserved.

The release of vitamin C from chewing gum and its effects on supragingival calculus formation.

Science.gov (United States)

Lingström, Peter; Fure, Solveig; Dinitzen, Bettina; Fritzne, Christina; Klefbom, Carin; Birkhed, Dowen

2005-02-01

The aims of this study were to evaluate (i): whether vitamin C in chewing gum, alone or in combination with carbamide, influences calculus formation, and (ii) whether carbamide affects the release, stability and uptake of vitamin C in a chewing gum. In two test series (Series I and II), 30 subjects, all calculus formers, participated. They were instructed to chew on five (Series I) or 10 (Series II) pieces of gum per day for a period of 3 months. The chewing gums were: vitamin C (60 mg, Series I), non-vitamin C (Series I) and vitamin C + carbamide (30 mg + 30 mg, Series II). In both series, no gum was used as a negative control. Calculus formation was scored on three lingual sites on the six anterior mandibular teeth according to the Volpe-Manhold index. The effect on plaque and gingivitis was also determined. A significant reduction in the total calculus score was observed after the use of vitamin C (33%) and vitamin C + carbamide (12%) gums compared with no gum use; this reduction was most pronounced in the heavy calculus formers. A reduced amount of visible plaque was also observed after use of vitamin C and non-vitamin C gum, but only the vitamin C gum reduced the number of bleeding sites (37%). In a separate study, the release, stability and uptake of vitamin C were evaluated using the iodine titration method in both saliva and urine after exposure to the following gums: vitamin C + carbamide (30 mg + 30 mg) and vitamin C (30 mg). There was no indication that carbamide affected the release, stability or uptake of vitamin C when used in a chewing gum.

Water adsorption isotherms of carboxymethyl cellulose, guar, locust bean, tragacanth and xanthan gums.

Science.gov (United States)

Torres, María D; Moreira, Ramón; Chenlo, Francisco; Vázquez, María J

2012-06-20

Water adsorption isotherms of carboxymethyl cellulose (CMC), guar gum (GG), locust bean gum (LBG), tragacanth gum (TG) and xanthan gum (XG) were determined at different temperatures (20, 35, 50, and 65°C) using a gravimetric method. Several saturated salt solutions were selected to obtain different water activities in the range from 0.09 to 0.91. Water adsorption isotherms of tested hydrocolloids were classified like type II isotherms. In all cases, equilibrium moisture content decreased with increasing temperature at each water activity value. Three-parameter Guggenheim-Anderson-de Boer (GAB) model was employed to fit the experimental data in the water activity range and statistical analysis indicated that this model gave satisfactory results. CMC and GG were the most and the least hygroscopic gums, respectively. Sorption heats decreased with increasing moisture content. Monolayer moisture content evaluated with GAB model was consistent with equilibrium conditions of maximum stability calculated from thermodynamic analysis of net integral entropy. Values of equilibrium relative humidity at 20°C are proposed to storage adequately the tested gums. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

Parrott, A C; Winder, G

1989-01-01

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 (RVIP), memory for new information, and heart rate. Nicotine raised heart rate in a significant monotonic dose-related manner (P less than 0.001): placebo +0.2; 2 mg gum +5.1; 4 mg gum +9.8; cigarette +17.5 bpm. Rapid visual information processing target detections were also significantly related to dose (P less than 0.01), with this increased vigilance significant under 4 mg nicotine gum and cigarette smoking. Memory task performance was not significantly affected. Self-reported feelings of alertness/energy were higher while smoking than under placebo or 4 mg gum. Complaints about the taste of the 4 mg nicotine gum were frequent.

Immunogenicity, immunological cross reactivity and non-specific irritant properties of the exudate gums, arabic, karaya and tragacanth.

Science.gov (United States)

Strobel, S; Ferguson, A; Anderson, D M

1986-01-01

An animal model has been used to investigate the immunogenicity and non-specific irritant properties of exudate gums. The materials studied were four preparations of gum arabic (Acacia spp.), two of gum karaya (Sterculia spp.), two of gum tragacanth (Astralagus spp.) and a residue obtained after ethanol extraction of gum arabic. Groups of animals were intradermally immunized with the gum in complete Freund's adjuvant. Serum antibody levels were measured by an ELISA technique and delayed hypersensitivity responses by a footpad swelling test. Antigenic cross-reactivity within each gum species was tested in a crossover fashion. All gum preparations elicited systemic immune responses after immunization. Further processing reduced immunogenicity, although there was no evidence that systemic immunity to these complex polysaccharide antigens responses could be completely abolished by processing or purification. The ethanolic extract, and some of the gum preparations, particularly tragacanth and karaya, caused considerable footpad swelling when injected intradermally. It is concluded that processing and awareness of subspecies differences can reduce the inherent immunogenicity and potential irritant effects of exudate gums.

High spin states and isomeric decays in doubly-odd 208Fr

International Nuclear Information System (INIS)

Kanjilal, D.; Bhattacharya, S.; Goswami, A.; Kshetri, R.; Raut, R.; Saha, S.; Bhowmik, R.K.; Gehlot, J.; Muralithar, S.; Singh, R.P.; Jnaneswari, G.; Mukherjee, G.; Mukherjee, B.

2010-01-01

Neutron deficient isotopes of francium (Z=87, N∼121-123) as excited nuclei were produced in the fusion-evaporation reaction: 197 Au( 16 O, xn) 213-x Fr at 100 MeV. The γ rays from the residues were observed through the high sensitivity Germanium Clover detector array INGA. The decay of the high spin states and the isomeric states of the doubly-odd 208 Fr nuclei, identified from the known sequence of ground state transitions, were observed. The half-lives of the E γ =194(2) keV isomeric transition, known from earlier observations, was measured to be T 1/2 =233(18) ns. A second isomeric transition at E γ =383(2) keV and T 1/2 =33(7) ns was also found. The measured half-lives were compared with the corresponding single particle estimates, based on the level scheme obtained from the experiment.

Isomeric periodic mesoporous organosilicas with controllable properties

NARCIS (Netherlands)

Vercaemst, C.; Ide, I.; Friedrich, H.; de Jong, K.P.; Verpoort, F.; van der Voort, P.

2009-01-01

The synthesis procedure for isomeric periodic mesoporous organosilicas with E-configured ethenylene bridges was investigated using the homemade pure E-isomer of 1,2-bis(triethoxysilyl)ethene. The pH, aging temperature and the presence of cosolvents played a key role in obtaining well-ordered

Iron microencapsulation in gum tragacanth using solvent evaporation method.

Science.gov (United States)

Asghari-Varzaneh, Elham; Shahedi, Mohammad; Shekarchizadeh, Hajar

2017-10-01

In this study iron salt (FeSO 4 ·7H 2 O) was microencapsulated in gum tragacanth hydrogel using solvent evaporation method. Three significant parameters (ferrous sulfate content, content of gum tragacanth, and alcohol to mixture ratio) were optimized by response surface methodology to obtain maximum encapsulation efficiency. Ferrous sulfate content, 5%, content of gum tragacanth, 22%, and alcohol to mixture ratio, 11:1 was determined to be the optimum condition to reach maximum encapsulation efficiency. Microstructure of iron microcapsules was thoroughly monitored using scanning electron microscopy (SEM). The microphotographs indicated two distinct crystalline and amorphous structures in the microcapsules. This structure was confirmed by X-ray diffraction (XRD) pattern of microcapsules. Fourier transform infrared (FTIR) spectra of iron microcapsules identified the presence of iron in the tragacanth microcapsules. The average size of microcapsules was determined by particle size analyzer. Release assessment of iron in simulated gastric fluid showed its complete release in stomach which is necessary for its absorption in duodenum. However, the use of encapsulated iron in gum tragacanth in watery foods is rather recommended due to the fast release of iron in water. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of alkali or acid treatment on the isomerization of amino acids.

Science.gov (United States)

Ohmori, Taketo; Mutaguchi, Yuta; Doi, Katsumi; Ohshima, Toshihisa

2012-10-01

The effect of alkali treatment on the isomerization of amino acids was investigated. The 100×D/(D+L) values of amino acids from peptide increased with increase in the number of constituent amino acid residues. Furthermore, the N-terminal amino acid of a dipeptide was isomerized to a greater extent than the C-terminal residue. Copyright © 2012. Published by Elsevier B.V.

Molecular isomerization induced by ultrashort infrared pulses. II. Pump-dump isomerization using pairs of time-delayed half-cycle pulses.

Science.gov (United States)

Uiberacker, Christoph; Jakubetz, Werner

2004-06-22

We investigate population transfer across the barrier in a double-well potential, induced by a pair of time-delayed single-lobe half-cycle pulses. We apply this setup both to a one-dimensional (1D) quartic model potential and to a three-dimensional potential representing HCN-->HNC isomerization. Overall the results for the two systems are similar, although in the 3D system some additional features appear not seen in the 1D case. The generic mechanism of population transfer is the preparation by the pump pulse of a wave packet involving delocalized states above the barrier, followed by the essentially 1D motion of the delocalized part of wave packet across the barrier, and the eventual de-excitation by the dump pulse to localized states in the other well. The correct timing is given by the well-to-well passage time of the wave packet and its recurrence properties, and by the signs of the field lobes which determine the direction and acceleration or deceleration of the wave packet motion. In the 3D system an additional pump-pump-dump mechanism linked to wave packet motion in the reagent well can mediate isomerization. Since the transfer time and the pulse durations are of the same order of magnitude, there is also a marked dependence of the dynamics and the transfer yield on the pulse duration. Our analysis also sheds light on the pronounced carrier envelope phase dependence previously observed for isomerization and molecular dissociation with one-cycle and sub-one-cycle pulses. (c) 2004 American Institute of Physics.

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

Science.gov (United States)

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

2014-08-01

Guar gum is a polysaccharide obtained from guar seed endosperm portion. Enzymatically hydrolyzed guar gum is low in viscosity and has several health benefits as dietary fiber. In this study, response surface methodology was used to determine the optimum conditions for hydrolysis that give minimum viscosity of guar gum. Central composite was employed to investigate the effects of pH (3-7), temperature (20-60 °C), reaction time (1-5 h) and cellulase concentration (0.25-1.25 mg/g) on viscosity during enzymatic hydrolysis of guar (Cyamopsis tetragonolobus) gum. A second order polynomial model was developed for viscosity using regression analysis. Results revealed statistical significance of model as evidenced from high value of coefficient of determination (R(2) = 0.9472) and P < 0.05. Viscosity was primarily affected by cellulase concentration, pH and hydrolysis time. Maximum viscosity reduction was obtained when pH, temperature, hydrolysis time and cellulase concentration were 6, 50 °C, 4 h and 1.00 mg/g, respectively. The study is important in optimizing the enzymatic process for hydrolysis of guar gum as potential source of soluble dietary fiber for human health benefits.

Isomeric rations study for the α + 70 Ge

International Nuclear Information System (INIS)

Hora Villano, M.H. da.

1984-12-01

Isomeric ratios for 73 Se F,I produced in the reaction α + 70 Ge with incidence laboratory energy ranging from 8 to 28 MeV, have been measured using off-line γ-ray spectroscopy. Relative formation cross-section for isomeric and ground states were obtained with NAT Ge targets. Compound nucleus statistical analyses were performed using computer codes Alice and Julian. Unlike to Alice code, the Julian code predictions agreed quite well with the experimental results. This agreement may be explained by the inclusion of the γ competition in the deexcitation channels of the compound nucleus and by the correct level density calculation of the emission probabilities in the Julian code. Finally angular momentum populations for isomers formations in the reaction 70 Ge(α, n) 73 have been determined. (author)

The influence of excessive chewing gum use on headache frequency and severity among adolescents.

Science.gov (United States)

Watemberg, Nathan; Matar, Manar; Har-Gil, Miki; Mahajnah, Muhammad

2014-01-01

Excessive gum-chewing is underreported as a headache precipitant in children and adolescents. We evaluated the influence of daily excessive gum-chewing in older children and teenagers with chronic headache, emphasizing the impact of habit discontinuation and its reintroduction. Patients with chronic headache and excessive gum-chewing were consecutively recruited and asked to fill questionnaire pertaining headache characteristics, potential triggers, family history of headaches, and gum-chewing habits. These individuals were classified into four groups depending on the number of daily hours of gum-chewing. All children discontinued chewing for 1 month, reintroduced the habit, and were reinterviewed after 2 to 4 weeks. Thirty patients (25 girls) were recruited. Median age was 16 years. Most had migraine-like headaches. Following gum-chewing discontinuation, 26 reported significant improvement, including headache resolution in 19. All 20 patients reinstituting the habit reported symptom relapse within days. Duration of headache before discontinuation and the number of daily hours of chewing had no influence on the response to habit discontinuation. Excessive daily gum-chewing may be associated with chronic headache and should get more attention in the medical literature. Physician and patient awareness of this association could have a meaningful impact on the quality of life of children and adolescents with chronic headache who chew gum excessively. Copyright © 2014 Elsevier Inc. All rights reserved.

Optimization of enzymatic hydrolysis of guar gum using response surface methodology

OpenAIRE

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

2012-01-01

Guar gum is a polysaccharide obtained from guar seed endosperm portion. Enzymatically hydrolyzed guar gum is low in viscosity and has several health benefits as dietary fiber. In this study, response surface methodology was used to determine the optimum conditions for hydrolysis that give minimum viscosity of guar gum. Central composite was employed to investigate the effects of pH (3–7), temperature (20–60 °C), reaction time (1–5 h) and cellulase concentration (0.25–1.25 mg/g) on viscosity d...

Gum cordia as carrier of antioxidants: effects on lipid oxidation of peanuts

OpenAIRE

Haq, Muhammad Abdul; Azam, Mahmood; Hasnain, Abid

2013-01-01

Performance of antioxidants is improved by incorporating them into polymer matrix such as polysaccharides based edible coatings. Gum cordia, an anionic polysaccharide extracted from the fruits of Cordia.myxa could be used as carrier of antioxidants by virtue of its strong adhering and emulsifying properties. This study aimed to explore the potential of gum cordia as carrier of antioxidants when applied as edible coating on peanuts. Gum Cordia was compared with carboxymethyl cellulose (CMC) in...

Structural, Thermal, Physical, Mechanical, and Barrier Properties of Chitosan Films with the Addition of Xanthan Gum.

Science.gov (United States)

de Morais Lima, Maria; Carneiro, Lucia Cesar; Bianchini, Daniela; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa; Prentice, Carlos; Moreira, Angelita da Silveira

2017-03-01

Films based on chitosan and xanthan gum were prepared using casting technique aiming to investigate the potential of these polymers as packaging materials. Six formulations of films were studied varying the proportion of chitosan and xanthan gum: 100:0 (chitosan:xanthan gum, w/w, C100XG0 film); 90:10 (chitosan:xanthan gum, w/w, C90XG10 film); 80:20 (chitosan:xanthan gum, w/w, C80XG20 film); 70:30 (chitosan:xanthan gum, w/w, C70XG30 film); 60:40 (chitosan:xanthan gum, w/w, C60XG40 film); and 50:50 (chitosan:xanthan gum, w/w, C50XG50 film). The total quantity of solids (chitosan and xanthan gum) in the filmogenic solution was 1.5 g per 100 mL of aqueous solution for all treatments, according to the proportion of each polymer. The films were evaluated by their functional groups, structural, thermal, morphological, physical, mechanical, and barrier properties. All films have presented endothermic peaks in the range of 122 to 175 °C and broad exothermic peaks above 200 °C, which were assigned to the melting temperature and thermal decomposition, respectively. These results demonstrated that films with xanthan gum have the highest T m and Δ m H. The films containing higher content of xanthan gum show also the highest tensile strength and the lowest elongation. Xanthan gum addition did not affect the water vapor permeability, solubility, and moisture of films. This set of data suggests the formation of chitosan-xanthan complexes in the films. © 2017 Institute of Food Technologists®.

Detrimental effects of gum chewing on vigilance in children with attention deficit hyperactivity disorder.

Science.gov (United States)

Tucha, Lara; Simpson, William; Evans, Lynsay; Birrel, Laura; Sontag, Thomas A; Lange, Klaus W; Tucha, Oliver

2010-12-01

Impairments of attention are cardinal features of attention deficit hyperactivity disorder (ADHD) and can seriously affect the daily life of children with ADHD. Despite effective treatment strategies, there is a need of further treatment options that can be added to available and well established treatments. Further treatment options are needed since available treatments are often time consuming, expensive and limited regarding their external validity. Recent research demonstrated that gum chewing has beneficial effects on cognition including certain aspects of attention. Therefore, gum chewing may benefit children with ADHD in situations requiring particular cognitive efforts. In a crossover study, attentional functioning of 32 children with ADHD and 32 children without the condition was examined. All participants were assessed with chewing gum and without chewing gum. A computerized test was used for the assessment of vigilance and sustained attention. The findings of the present study suggest that gum chewing during task execution has detrimental effects on vigilance of both healthy children and children with ADHD. Sustained attention was not affected by gum chewing. Chewing gum, therefore, appears not to improve attentional performance in children with ADHD. Copyright © 2010 Elsevier Ltd. All rights reserved.

Elucidation of structural isomers from the homogeneous rhodium-catalyzed isomerization of vegetable oils.

Science.gov (United States)

Andjelkovic, Dejan D; Min, Byungrok; Ahn, Dong; Larock, Richard C

2006-12-13

The structural isomers formed by the homogeneous rhodium-catalyzed isomerization of several vegetable oils have been elucidated. A detailed study of the isomerization of the model compound methyl linoleate has been performed to correlate the distribution of conjugated isomers, the reaction kinetics, and the mechanism of the reaction. It has been shown that [RhCl(C8H8)2]2 is a highly efficient and selective isomerization catalyst for the production of highly conjugated vegetable oils with a high conjugated linoleic acid (CLA) content, which is highly desirable in the food industry. The combined fraction of the two major CLA isomers [(9Z,11E)-CLA and (10E,12Z)-CLA] in the overall CLA mixture is in the range from 76.2% to 93.4%. The high efficiency and selectivity of this isomerization method along with the straightforward purification process render this approach highly promising for the preparation of conjugated oils and CLA. Proposed improvements in catalyst recovery and reusability will only make this method more appealing to the food, paint, coating, and polymer industries in the future.

The role of time on task performance in modifying the effects of gum chewing on attention.

Science.gov (United States)

Tucha, Lara; Simpson, William

2011-04-01

Recent research examined the effects of chewing gum on attention and reported a significant interaction of gum chewing with time. Using a crossover within-subject design, the present study examined the effect of gum chewing on sustained attention in healthy adults over a period of 30 min. The results revealed a significant main effect of time and a significant interaction between gum chewing and time. The findings suggest that gum chewing differentially affects attention performance. While gum chewing has detrimental effects on sustained attention in earlier stages of the task, beneficial effects on sustained attention were observed at later stages. Copyright © 2010 Elsevier Ltd. All rights reserved.

Possible evidence for shape isomeric γ-decay in μ- atoms of 238U

International Nuclear Information System (INIS)

Fromm, W.D.; Ortlepp, H.-G.; Polikanov, S.M.; Schmidt, U.; Zorin, G.N.; Arlt, R.; Musiol, G.

1977-01-01

A search for the γ-decay of the shape isomer in muonic 238 U excited by radiationless transitions has been performed. Seven delayed transitions in the energy region of 700 to 3200 keV have been observed with a large Ge(Li) detector. Two transitions with Esub(γ)=2215 and 3131 keV have been attributed to the decay of the shape isomeric state into levels in the first well. The isomeric shift of the second minimum Esub(II) approximately 600 keV in the presence of the muon and the decrease of the lifetime of the shape isomer to tau=12+-2 ns give arguments in favour of the connection of shape isomerism with large quadrupole deformations. (Auth.)

Tragacanth gum: an effective oil well drilling fluid additive

Energy Technology Data Exchange (ETDEWEB)

Mahto, V.; Sharma, V. [Indian School of Mines, Dhanbad (India). Department of Petroleum Engineering

2005-02-15

The low penetration rate, excessive torque and drag, poor hole cleaning and formation damage are major impediments in drilling oil and gas well. These have a major impact on drilling efficiency and well economics. Keeping these in mind, an attempt was made to design a water based drilling fluid system using Indian bentonite clays and tragacanth gum. The effect of tragacanth gum on rheological behavior of three different Indian bentonite water suspensions was studied and a drilling fluid system was developed. The filtrates of these drilling fluids were subjected to formation damage study on the field core using Ruska Liquid Permeameter. The laboratory investigation furnishes that tragacanth gum acts as a good viscosifier and fluid loss control agent. The drilling fluid filtrate also has less effect on formation damage. (author)

Low-lying isomeric levels in Cu75

Science.gov (United States)

Daugas, J. M.; Faul, T.; Grawe, H.; Pfützner, M.; Grzywacz, R.; Lewitowicz, M.; Achouri, N. L.; Angélique, J. C.; Baiborodin, D.; Bentida, R.; Béraud, R.; Borcea, C.; Bingham, C. R.; Catford, W. N.; Emsallem, A.; de France, G.; Grzywacz, K. L.; Lemmon, R. C.; Lopez Jimenez, M. J.; de Oliveira Santos, F.; Regan, P. H.; Rykaczewski, K.; Sauvestre, J. E.; Sawicka, M.; Stanoiu, M.; Sieja, K.; Nowacki, F.

2010-03-01

Isomeric low-lying states were identified and investigated in the Cu75 nucleus. Two states at 61.8(5)- and 128.3(7)-keV excitation energies with half-lives of 370(40)- and 170(15)-ns were assigned as Cu75m1 and Cu75m2, respectively. The measured half-lives combined with the recent spin assignment of the ground state allow one to deduce tentatively spin and parity of the two isomers and the dominant multipolarities of the isomeric transitions with respect to the systematics of the Cu isotopes. Shell-model calculations using an up-to-date effective interaction reproduce the evolution of the 1/2-, 3/2-, and 5/2- states for the neutron-rich odd-mass Cu isotopes when filling the νg9/2. The results indicate a significant change in the nuclear structure in this region, where a single-particle 5/2- state coexists with more and more collective 3/2- and 1/2- levels at low excitation energies.

Influence of tragacanth gum in egg white based bioplastics: Thermomechanical and water uptake properties.

Science.gov (United States)

López-Castejón, María Luisa; Bengoechea, Carlos; García-Morales, Moisés; Martínez, Inmaculada

2016-11-05

This study aims to extend the range of applications of tragacanth gum by studying its incorporation into bioplastics formulation, exploring the influence that different gum contents (0-20wt.%) exert over the thermomechanical and water uptake properties of bioplastics based on egg white albumen protein (EW). The effect of plasticizer nature was also evaluated through the modification of the water/glycerol ratio within the plasticizer fraction (fixed at 40wt.%). The addition of tragacanth gum generally yielded an enhancement of the water uptake capacity, being doubled at the highest content. Conversely, presence of tragacanth gum resulted in a considerable decrease in the bioplastic mechanical properties: both tensile strength and maximum elongation were reduced up to 75% approximately when compared to the gum-free system. Ageing of selected samples was also studied, revealing an important effect of storage time when tragacanth gum is present, possibly due to its hydrophilic character. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multi-quasiparticle high-K isomeric states in deformed nuclei

Directory of Open Access Journals (Sweden)

Xu F. R.

2016-01-01

Full Text Available In the past years, we have made many theoretical investigations on multi-quasiparticle high-K isomeric states. A deformation-pairing-configuration self-consistent calculation has been developed by calculating a configuration-constrained multi-quasiparticle potential energy surface (PES. The specific single-particle orbits that define the high-K configuration are identified and tracked (adiabatically blocked by calculating the average Nilsson numbers. The deformed Woods-Saxon potential was taken to give single-particle orbits. The configuration-constrained PES takes into account the shape polarization effect. Such calculations give good results on excitation energies, deformations and other structure information about multi-quasiparticle high-K isomeric states. Many different mass regions have been investigated.

Promotion or suppression of glucose isomerization in subcritical aqueous straight- and branched-chain alcohols.

Science.gov (United States)

Gao, Da-Ming; Kobayashi, Takashi; Adachi, Shuji

2015-01-01

The influence of water-miscible alcohols (methanol, 1-propanol, 2-propanol, and t-butyl alcohol) on the isomerization of glucose to fructose and mannose was investigated under subcritical aqueous conditions (180-200 °C). Primary and secondary alcohols promoted the conversion and isomerization of glucose to afford fructose and mannose with high and low selectivity, respectively. On the other hand, the decomposition (side-reaction) of glucose was suppressed in the presence of the primary and secondary alcohols compared with that in subcritical water. The yield of fructose increased with increasing concentration of the primary and secondary alcohols, and the species of the primary and secondary alcohols tested had little effect on the isomerization behavior of glucose. In contrast, the isomerization of glucose was suppressed in subcritical aqueous t-butyl alcohol. Both the conversion of glucose and the yield of fructose decreased with increasing concentration of t-butyl alcohol. In addition, mannose was not detected in reactions using subcritical aqueous t-butyl alcohol.

A Novel Technique that Enables Efficient Conduct of Simultaneous Isomerization and Fermentation (SIF) of Xylose

Science.gov (United States)

Rao, Kripa; Chelikani, Silpa; Relue, Patricia; Varanasi, Sasidhar

Of the sugars recovered from lignocellulose, D-glucose can be readily converted into ethanol by baker's or brewer's yeast (Saccharomyces cerevisiae). However, xylose that is obtained by the hydrolysis of the hemicellulosic portion is not fermentable by the same species of yeasts. Xylose fermentation by native yeasts can be achieved via isomerization of xylose to its ketose isomer, xylulose. Isomerization with exogenous xylose isomerase (XI) occurs optimally at a pH of 7-8, whereas subsequent fermentation of xylulose to ethanol occurs at a pH of 4-5. We present a novel scheme for efficient isomerization of xylose to xylulose at conditions suitable for the fermentation by using an immobilized enzyme system capable of sustaining two different pH microenvironments in a single vessel. The proof-of-concept of the two-enzyme pellet is presented, showing conversion of xylose to xylulose even when the immobilized enzyme pellets are suspended in a bulk solution whose pH is sub-optimal for XI activity. The co-immobilized enzyme pellets may prove extremely valuable in effectively conducting "simultaneous isomerization and fermentation" (SIF) of xylose. To help further shift the equilibrium in favor of xylulose formation, sodium tetraborate (borax) was added to the isomerization solution. Binding of tetrahydroxyborate ions to xylulose effectively reduces the concentration of xylulose and leads to increased xylose isomerization. The formation of tetrahydroxyborate ions and the enhancement in xylulose production resulting from the complexation was studied at two different bulk pH values. The addition of 0.05 M borax to the isomerization solution containing our co-immobilized enzyme pellets resulted in xylose to xylulose conversion as high as 86% under pH conditions that are suboptimal for XI activity. These initial findings, which can be optimized for industrial conditions, have significant potential for increasing the yield of ethanol from xylose in an SIF approach.

Microscopic study of gum-metal alloys: A role of trace oxygen for dislocation-free deformation

International Nuclear Information System (INIS)

Nagasako, Naoyuki; Asahi, Ryoji; Isheim, Dieter; Seidman, David N.; Kuramoto, Shigeru; Furuta, Tadahiko

2016-01-01

A class of Ti–Nb–Ta–Zr–O alloys called gum metal are known to display high strength, low Young's modulus and high elastic deformability up to 2.5%, simultaneously, and considered to deform by a dislocation-free deformation mechanism. A trace of oxygen (∼1%) in gum metal is indispensable to realize such significant properties; however, the detailed mechanism and the role of the oxygen has not been understood. To investigate an effect of trace oxygen included in gum metal, first-principles calculations for gum-metal approximants including zirconium and oxygen are performed. Calculated results clearly indicate that oxygen site with less neighboring Nb atom is energetically favorable, and that Zr–O bonding has an important role to stabilize the bcc structure of gum metal. The three-dimensional atom-probe tomography (3-D APT) measurements for gum metal were also performed to identify compositional inhomogeneity attributed to the trace elements. From the 3-D APT measurements, Zr ions bonding with oxygen ions are observed, which indicates existence of Zr–O nano-clusters in gum metal. Consequently, it is found that (a) coexistence of Zr atom and oxygen atom improves elastical stability of gum metal, (b) inhomogeneous distribution of the compositions induced by the trace elements causes anisotropical change of shear moduli, and (c) Zr–O nano-clusters existing in gum metal are expected to be obstacles to suppress movemen of dislocations.

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

Science.gov (United States)

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

2007-12-21

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

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

Science.gov (United States)

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

2012-02-01

In this study, the physicochemical properties of a low-fat dried yogurt paste (kashk) were determined, and the effects of different concentrations (0, 0·1, 0·3 and 0·5% w/w) of gum tragacanth exudates from Astragalus gossypinus on the stability and texture of the samples were investigated by measuring amount of syneresis, turbidity, particle size distribution (PSD), flow behaviour and viscoelastic properties. The flow behaviour index was not very sensitive to the concentration of gum, while a remarkable concentration dependency of the power-law consistency coefficient and Herschel-Bulkley yield stress was observed. The initial increase in the gum concentration at 0·1 and 0·3% levels led to a higher degree of syneresis, which was related to the depletion flocculation mechanism. However, the reduced amount of syneresis in samples containing 0·5% gum tragacanth was attributed to the significant increase in viscosity of the continuous phase, which is also accompanied by trapping of the aggregated casein particles. The presence of 3% salt in the samples may have led to the neutralization of charges on the surface of gum tragacanth; consequently, the non-adsorbing behaviour of high-ionic-strength polysaccharides inhibited the formation of electrostatic protein-polysaccharide complexes. Furthermore, maximum values of polydispersity, syneresis and tan δ at high frequencies were found in samples containing 0·1% gum tragacanth.

Guar gum effects on food intake, blood serum lipids and glucose levels of Wistar rats.

Science.gov (United States)

Frias, A C; Sgarbieri, V C

1998-01-01

The effects of guar gum derived from the endosperm of Cyamopsis tetragonoloba (75% soluble fiber, 7.6% insoluble fiber, 2.16% crude protein, 0.78% total lipids, 0.54% ash and 9.55% moisture) on food intake, levels of blood serum cholesterol, triacylglycerols, glucose and LDL and HDL-cholesterol were studied. The effects of guar gum on indices of protein absorption and utilization were also investigated. Diets containing 0%, 10% and 20% (w/w) guar gum or 10% and 20% cellulose powder (reference) were fed to normal rats for 60 days. The rats fed the guar gum diets showed significantly (p Guar gum decreased blood serum glucose only during the first month of the experiment, and no changes in the indices of protein absorption and utilization were found. The guar gum caused a 10% increase in the small intestine length and a 25% retardation in the intestinal transit. The results of this research suggested that guar gum could potentially be effective in the treatment of hypercholesterolemia and obesity in humans.

Compositional analysis and rheological characterization of gum tragacanth exudates from six species of Iranian Astragalus

DEFF Research Database (Denmark)

Balaghi, Sima; Mohammadifar, Mohammad Amin; Zargaraan, Azizollaah

2011-01-01

The sugar composition and viscoelastic behaviour of Iranian gum tragacanth exuded by six species of Astragalus was investigated at a concentration of 1.3% and varying ionic strength using a controlled shear-rate rheometer. Compositional analysis of the six species of gum tragacanth by high...... of Astragalus, and this variation led to interesting differences in functional properties. Rheological measurements performed on dispersions of the six species of gum tragacanth demonstrated viscoelastic properties. The mechanical spectra derived from strain sweep and frequency sweep measurements indicated...... that the different gum tragacanth dispersions had distinctive viscoelastic behaviours. Investigation of the viscoelastic properties of the different gum dispersions in the presence of NaCl revealed that the addition of NaCl could lead to slight to drastic decreases in the G′, G″ or η∗ values of the various gums...

Seeds of genus Cassia as possible sources of industrial gums

Energy Technology Data Exchange (ETDEWEB)

Farooqi, M I.H.; Kapoor, V P; Islam, G

1978-01-01

Water-soluble mucilages (gums) and their properties were determined for the seeds of twenty Indian Cassia species, including nine trees and nine shrubs. The seeds of the shrub C. alata were regarded as the best potential commercial source of gums; those of the trees C. fistula, C. grandis, C. javanica, C. marginata and C. multijuga were also promising.

Economic incentives for abandoning or expanding gum arabic production in Sudan

NARCIS (Netherlands)

Rahim, A.; Ierland, van E.C.; Wesseler, J.H.H.

2007-01-01

In this paper we use a real options approach to analyze farmers' economic incentives to abandon gum production or expand by creating new plantations. Our results indicate that agricultural crops currently provide higher economic benefits as compared to gum agroforestry. However, we show that the

New isomeric states in 152,154,156Nd produced by spontaneous fission of 252Cf

International Nuclear Information System (INIS)

Gautherin, C.; Houry, M.; Korten, W.; Le Coz, Y.; Lucas, R.; Phan, X.H.; Theisen, C.; Belier, G.; Girod, M.; Meot, V.; Peru, S.; Astier, A.; Ducroux, L.; Meyer, M.; Redon, N.

1998-01-01

Isomeric states have been observed in fission-fragments produced by spontaneous fission of 252 Cf. These states are found in neutron rich nuclei of different structure and deformations. About 50 isomeric nuclei have been observed using coincidences between γ-rays identified in EUROGAM II and fission fragments detected in photovoltaic cells (SAPhIR). Lifetimes in the range from 20 ns to 2μs have been measured. Presented calculations based on HFB+D1S force on new measured isomeric states in the 152,154,156 Nd show evidence for K-isomers. (orig.)

Gellan gum fluid gels for topical administration of diclofenac.

Science.gov (United States)

Mahdi, Mohammed H; Conway, Barbara R; Mills, Thomas; Smith, Alan M

2016-12-30

Diclofenac topical formulations are often preferred for drug administration to patients who experience serious GIT problems. Absorption of the drug through the skin, however, can be challenging due to the natural protective feature of the stratum corneum (SC). In this article, fluid gels prepared from gellan gum were explored as a topical drug delivery vehicle. Rheological analysis of the formulations showed that it was possible to produce a topical gel with a viscosity and the mechanical strength similar to that of the commercially available Voltaren ® gel using 1% w/w of a 50:50 low acyl/high acyl (LA/HA) gellan blend. Soft-tribology was used to assess the lubrication properties of gellan fluid gels. The lubrication of the gellan gum fluid gel formulations at high rubbing speeds was similar to the lubrication of the Voltaren ® gel. The use of gellan gum dramatically increased skin permeation of diclofenac when compared with the commercially available formulation and could be controlled by changing the gellan gum concentration and/or sodium ion concentration in the formulation. This study highlights the potential use of fluid gels that can be easily tuned to have physical properties suitable for topical formulations with the added advantage of increasing drug permeation. Copyright © 2016 Elsevier B.V. All rights reserved.

Behavioral economic substitutability of e-cigarettes, tobacco cigarettes, and nicotine gum.

Science.gov (United States)

Johnson, Matthew W; Johnson, Patrick S; Rass, Olga; Pacek, Lauren R

2017-07-01

The public health impact of e-cigarettes may depend on their substitutability for tobacco cigarettes. Dual users of e-cigarettes and tobacco cigarettes completed purchasing tasks in which they specified daily use levels under hypothetical conditions that varied the availability and price of e-cigarettes, tobacco cigarettes, and nicotine gum (for those with nicotine gum experience). When either e-cigarettes or tobacco cigarettes were the only available commodity, as price per puff increased, purchasing decreased, revealing similar reinforcement profiles. When available concurrently, as the price of tobacco puffs increased, purchasing of tobacco puffs decreased while purchasing of fixed-price e-cigarette puffs increased. Among those with nicotine gum experience, when the price of tobacco puffs was closest to the actual market value of tobacco puffs, e-cigarette availability decreased median tobacco puff purchases by 44% compared to when tobacco was available alone. In contrast, nicotine gum availability caused no decrease in tobacco puff purchases. E-cigarettes may serve as a behavioral economic substitute for tobacco cigarettes, and may be a superior substitute compared to nicotine gum in their ability to decrease tobacco use. Although important questions remain regarding the health impacts of e-cigarettes, these data are consistent with the possibility that e-cigarettes may serve as smoking cessation/reduction aids.

Effects of short-term xylitol gum chewing on the oral microbiome.

Science.gov (United States)

Söderling, Eva; ElSalhy, Mohamed; Honkala, Eino; Fontana, Margherita; Flannagan, Susan; Eckert, George; Kokaras, Alexis; Paster, Bruce; Tolvanen, Mimmi; Honkala, Sisko

2015-03-01

The aim of this study was to determine the effects of short-term xylitol gum chewing on the salivary microbiota of children. The study was a randomised, controlled, double-blind trial. Healthy children used xylitol chewing gum (xylitol group, n = 35) or sorbitol chewing gum (control group, n = 38) for 5 weeks. The daily dose of xylitol/sorbitol was approximately 6 g/day. At baseline and at the end of the test period, unstimulated and paraffin-stimulated saliva were collected. The microbial composition of the saliva was assessed using human oral microbe identification microarray (HOMIM). Mutans streptococci (MS) were plate cultured. As judged by HOMIM results, no xylitol-induced changes in the salivary microbiota took place in the xylitol group. In the control group, Veillonella atypica showed a significant decrease (p = 0.0001). The xylitol gum chewing decreased viable counts of MS in both stimulated (p = 0.006) and unstimulated (p = 0.002) saliva, but similar effects were also seen in the control group. The use of xylitol gum decreased MS, in general, but did not change the salivary microbial composition. Short-term consumption of xylitol had no impact on the composition of the salivary microbiota, but resulted in a decrease in the levels of MS.

Surface analysis characterisation of gum binders used in modern watercolour paints

Science.gov (United States)

Sano, Naoko; Cumpson, Peter J.

2016-02-01

Conducting this study has demonstrated that not only SEM-EDX but also XPS can be an efficient tool for characterising watercolour paint surfaces. We find that surface effects are mediated by water. Once the powdered components in the watercolour come into contact with water they dramatically transform their chemical structures at the surface and show the presence of pigment components with a random dispersion within the gum layer. Hence the topmost surface of the paint is confirmed as being composed of the gum binder components. This result is difficult to confirm using just one analytical technique (either XPS or SEM-EDX). In addition, peak fitting of C1s XPS spectra suggests that the gum binder in the commercial watercolour paints is probably gum arabic (by comparison with the reference materials). This identification is not conclusive, but the combination techniques of XPS and SEM shows the surface structure with material distribution of the gum binder and the other ingredients of the watercolour paints. Therefore as a unique technique, XPS combined with SEM-EDX may prove a useful method in the study of surface structure for not only watercolour objects but also other art objects; which may in future help in the conservation for art.

Determination of the active site and mechanism for alkene isomerization in Cu(II) exchnaged Y-type zeolite

Energy Technology Data Exchange (ETDEWEB)

John, C S; Leach, H F

1977-01-01

An ESR study of 1-butene isomerization at 315/sup 0/-375/sup 0/C, 3,3-dimethyl-1-butene isomerization to 2,3-dimethyl-1- and -2-butene at 293/sup 0/K, and deuterium redistribution in 3,3-dideuteriopropene at 363/sup 0/-396/sup 0/K showed the presence of two copper(II) species in different environments, which reacted with the olefins at different rates. Although activation energies for the three reactions differed and only dideuteriopropene showed an induction period, a similar mechanism is proposed in all cases, involving preliminary reduction of copper(II), with the rates of reduction and isomerization differing from olefin to olefin. Apparently, the active site for the isomerization is a Broensted acid generated by the reduction, and the isomerization follows an associative (proton addition-elimination) mechanism with a carbonium ion intermediate. Spectra, graphs, diagram, and 12 references.

Iridium-Catalyzed Dynamic Kinetic Isomerization: Expedient Synthesis of Carbohydrates from Achmatowicz Rearrangement Products.

Science.gov (United States)

Wang, Hao-Yuan; Yang, Ka; Bennett, Scott R; Guo, Sheng-rong; Tang, Weiping

2015-07-20

A highly stereoselective dynamic kinetic isomerization of Achmatowicz rearrangement products was discovered. This new internal redox isomerization provided ready access to key intermediates for the enantio- and diastereoselective synthesis of a series of naturally occurring sugars. The nature of the de novo synthesis also enables the preparation of both enantiomers. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Using Gamma Irradiation to Modify Properties of Polysaccharides (Guar Gum)

International Nuclear Information System (INIS)

Sayed, H.

2015-01-01

Radiation processing of material is one of most recent technology used in modification of material properties. The aim of this work was to determine the effect of gamma irradiation on the Polysaccharides Viscosity and Molecular Weight, as definition of Guar Gum. Its series of glactomanene (glactos + manose). (1-2-,3). Guar Gum powder was the main material and Co-60 irradiator facility as main technique. For gamma–ray source of required doses, 2.5, 5, 7.5, 10, 20, 30, 40 and 50 kGy. Viscosity of the aqueous suspensions of irradiated Guar Gum at different concentrations (0.1–0.5%) was measured, also it measured for solutions made of irradiated powder. Results used to calculate the difference occur in molecular weight, in order to determine the irradiation effect in the material. The monitored rheological parameters showed (non-Newtonian Behavior) of the samples which processed by gamma irradiation. The decrease tendency of the viscosity by irradiation of samples under study (different concentrations) and compared with control also for irradiated powder decrease of the concentration as well has been noticed. From results evaluation concluded that the viscosity values for all studied concentrations decreased by irradiation. This aspect suggests a depolymerization phenomenon of the aqueous Guar Gum solutions. This study contributes to the knowledge of the viscoelastic properties of Guar Gum as powder or aqueous solution, with application for food, agriculture, medical products, Petroleum and construction. (author)

The next GUM and its proposals: a comparison study

Science.gov (United States)

Damasceno, J. C.; Couto, P. R. G.

2018-03-01

The Guide to the Expression of Uncertainty in Measurement (GUM) is currently under revision. New proposals for its implementation were circulated in the form of a draft document. Two of the main changes are explored in this work using a Brinell hardness model example. Changes in the evaluation of uncertainty for repeated indications and in the construction of coverage intervals are compared with the classic GUM and with Monte Carlo simulation method.

Gum forming olefinic precursors in motor gasoline: a model compound study

Energy Technology Data Exchange (ETDEWEB)

Nagpal, J.M.; Joshi, G.C.; Singh, J.; Rastogi, S.N. (Indian Institute of Petroleum, Dehradun (India))

1994-01-01

The source of the cracked components in motor gasoline are generally (Fluid Catalytic Cracking) FCC and thermal cracking naphthas incorporated in the gasoline pool. The FCC olefins are predominant in isostructures, while thermal cracking naphthas obtained from visbreaking and coking operations contain substantial amounts of cyclic structures. The contribution of various olefinic structures present in these naphthas are likely to vary. The gum forming tendencies of different types of olefinic structures have been studied by taking model compounds in a known sample matrix through potential gum measurements under accelerated test conditions. Peroxide number values have also been determined on aged sample. Cyclic and dicyclic structures have been found to contribute maximum, towards gum formation tendencies. Branching generally increases the gum formation. However, position of branching plays an important role besides the double bond. Synergistic effects of dienes with straight chain and branched olefins have also been studied. 11 refs., 10 figs., 2 tabs.

Whole and crushed nutlets of chia (Salvia hispanica from Mexico as a source of functional gums

Directory of Open Access Journals (Sweden)

Maira Segura-Campos

2014-12-01

Full Text Available The objective of this study was to characterize the chemical and functional properties of Mexican chia (Salvia hispanica gums extracted from defatted whole and crushed nutlets using the Soxhlet and SFE-CO2 methods. Chia gums have interesting chemical and functional properties for the food industry. The oil and gum yields were in the range of 1.98-16.42% and 5.81-12.60%, respectively. The defatting procedure did not affect significantly the oil and gum extraction; the nutlet type (whole or crushed was the only parameter influencing the yield. The proximate composition and the protein and fiber contents of chia gum were evaluated. Low contents of protein and fiber and high NFE levels were found in whole nutlet gums. The functional properties of chia gum extracted from whole and crushed nutlets with the Soxhlet and SFE-COs methods showed the following ranges of water absorption capacity of 62.64 to 143.66 g/g, water adsorption capacity of 0.69 to 1.35 g/g, and water and oil holding capacity of 100 to 149.28 g/g and19.5 to 40.4 g/g, respectively. The rheological behavior exhibited by the gums was pseudoplastic or shear thinning. From a functional perspective, chia gum is an important food component due its emulsifier and stabilizer potentials.

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

Science.gov (United States)

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

2007-09-01

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

Preparing isomerically pure beams of short-lived nuclei at JYFLTRAP

Energy Technology Data Exchange (ETDEWEB)

Eronen, T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), FIN-40014 (Finland)], E-mail: tommi.eronen@jyu.fi; Elomaa, V.-V.; Hager, U.; Hakala, J.; Jokinen, A.; Kankainen, A.; Rahaman, S.; Rissanen, J.; Weber, C.; Aystoe, J. [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), FIN-40014 (Finland)

2008-10-15

A new procedure to prepare isomerically clean samples of short-lived ions with a mass resolving power of more than 1 x 10{sup 5} has been developed at the JYFLTRAP tandem Penning trap system. The method utilises a dipolar rf-excitation of the ion motion with separated oscillatory fields in the precision trap. During a subsequent retransfer to the purification trap, the contaminants are rejected and as a consequence, the remaining bunch is isomerically cleaned. This newly-developed method is suitable for very high-resolution cleaning and is at least a factor of five faster than the methods used so far in Penning trap mass spectrometry.

A SANS study of the adsorption of guar gum on talc surfaces

International Nuclear Information System (INIS)

Cram, S.L.; Knott, R.; Hanley, H.

2002-01-01

Reagents based on guar gum are commonly used as 'gangue' depressants in the flotation of sulphides from ores containing naturally floating layer silicate minerals such as talc. Nickel sulphide ores processed by WMC Resources Ltd. at the Leinster Nickel Operations in Western Australia typically contain 1-2 % talc. Guar gum, added to the flotation cell, depresses the talc by adsorbing onto its surface, thereby reducing its hydrophobic nature. Guar gum is a long chain polysaccharide containing many hydroxyl functional groups along the length of its chain. The ratio of chain length to the number of hydroxyl and carboxyl groups causes the guar gum to be selective in depressing talc rather than nickel sulphide minerals. Small angle neutron scattering (SANS) it is an excellent tool for probing structures in the nano length scale. Unlike X-rays, neutrons are sensitive to low atomic weight elements, especially hydrogen and therefore organics. Using SANS it is possible to contrast different parts of a composite sample to get information on spatial arrangements. These qualities make SANS an obvious choice for studying the adsorption of guar gum on the surface of talc in aqueous solutions. Complimentary SANS experiments were carried out in Australia at the Australian Nuclear Science and Technology Organisation (ANSTO) and in the United States at the National Institute of Standards and Technology (NIST). Initially talc samples were studied 'as supplied', however as experiments proceeded attempts to reduce the particle size and distribution were carried out by milling and centrifuging procedures. Contrast matching techniques were used to observed the scattering behaviour of talc with and without the presence of guar gum and vice versa, over a total q range of 0.002 - 0.1 Angstroms -1 . The size of the talc particles appears to affect the scattering behaviour not only of talc but also of guar gum in the same solutions. This implies that the structure of the guar gum is strongly

Dependence levels in users of electronic cigarettes, nicotine gums and tobacco cigarettes.

Science.gov (United States)

Etter, Jean-François; Eissenberg, Thomas

2015-02-01

To assess dependence levels in users of e-cigarettes, and compare them with dependence levels in users of nicotine gums and tobacco cigarettes. Self-reports from cross-sectional Internet and mail surveys. Comparisons of: (a) 766 daily users of nicotine-containing e-cigarettes with 30 daily users of nicotine-free e-cigarettes; (b) 911 former smokers who used the e-cigarette daily with 451 former smokers who used the nicotine gum daily (but no e-cigarette); (c) 125 daily e-cigarette users who smoked daily (dual users) with two samples of daily smokers who did not use e-cigarettes (2206 enrolled on the Internet and 292 enrolled by mail from the general population of Geneva). We used the Fagerström test for nicotine dependence, the nicotine dependence syndrome scale, the cigarette dependence scale and versions of these scales adapted for e-cigarettes and nicotine gums. Dependence ratings were slightly higher in users of nicotine-containing e-cigarettes than in users of nicotine-free e-cigarettes. In former smokers, long-term (>3 months) users of e-cigarettes were less dependent on e-cigarettes than long-term users of the nicotine gum were dependent on the gum. There were few differences in dependence ratings between short-term (≤3 months) users of gums or e-cigarettes. Dependence on e-cigarettes was generally lower in dual users than dependence on tobacco cigarettes in the two other samples of daily smokers. Some e-cigarette users were dependent on nicotine-containing e-cigarettes, but these products were less addictive than tobacco cigarettes. E-cigarettes may be as or less addictive than nicotine gums, which themselves are not very addictive. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Matrix Effect on the Spray Drying Nanoencapsulation of Lippia sidoides Essential Oil in Chitosan-Native Gum Blends.

Science.gov (United States)

Paula, Haroldo C B; Oliveira, Erick F; Carneiro, Maria J M; de Paula, Regina C M

2017-03-01

Essential oils have many applications in the pharmaceutical, chemical, and food fields, however, their use is limited to the fact that they are very labile, requiring their a priori encapsulation, aiming to preserve their properties.This work reports on the preparation of chitosan-gum nanoparticles loaded with thymol containing Lippia sidoides essential oil, using exudates of Anacardium Occidentale (cashew gum), Sterculia striata (chichá gum), and Anadenanthera macrocarpa trees (angico gum). Nanoparticles were produced by spray drying an emulsion of L. sidoides essential oil and aqueous solution of gums with different chitosan : gum ratios. Samples were characterized by FTIR and UV/VIS spectroscopy, particle size, volume distribution, and zeta potential. The FTIR spectrum showed the main signals of chitosan and the gums. Data obtained revealed that the samples had sizes in the nano range, varying from 17 nm to 800 nm. The zeta potential varied from + 30 mV to - 40 mV. Nanoparticle loading values varied from 6.7 % to 15.6 %, with an average encapsulating efficiency of 62 %, where the samples with high ratios of cashew gum and chichá gum presented high oil loading values. The data revealed that both the chitosan : gum ratio and polysaccharide characteristics play major roles in nanoencapsulation processes. Georg Thieme Verlag KG Stuttgart · New York.

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

Science.gov (United States)

Singh, Baljit; Sharma, Vikrant

2013-11-01

Keeping in view the influence of gamma radiation on the physiochemical properties of the polysaccharides and their importance in the food and pharmaceutical industry, in the present study attempt has been made to investigate the effects of absorbed dose on FTIR, XRD, SEMs, absorbance, pH, solubility, water absorption capacity, emulsion stability and rheology of sterculia gum. Increase in solubility and decrease in swellability of gum has been observed on increasing the absorbed dose. The emulsion stability has improved for the gum sample irradiated with total dose of 8.1±0.2 kGy. Apparent viscosity of gum solution first increased with increase in dose from 0 to 8.1±0.2 kGy than decreased with regular trends with further increase in total absorbed dose. Flow behavior of gum solution shifted to Newtonian from non-Newtonian with increasing the dose.

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

Science.gov (United States)

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

2013-03-01

The purpose of this study was to identify the risk factors associated with the masticatory dysfunction after maxillectomy using a colour-changing chewing gum. Thirty-nine patients who underwent maxillectomy between January 2002 and May 2010 in the Department of Kobe University Hospital were recruited for this study. There were 20 male and 19 female subjects, with a median age of 73·3 years (range of 44-90) at the time of surgery. The intra-oral conditions after maxillectomy were classified by HS classification, and the masticatory function was evaluated by a colour-changing chewing gum and the results of a modified Sato's questionnaire. The scores of the colour-changing gum were closely correlated with the scores of the modified Sato's questionnaire (r = 0·661, P gum test masticatory dysfunction were the number of anchor teeth ≤2 and a soft palate defect. A colour-changing gum was found to be useful for evaluating the post-operative masticatory function, and it was important to conserve the anchor teeth and the soft palate to avoid masticatory dysfunction. © 2012 Blackwell Publishing Ltd.

A study of guar seed and guar gum properties (Cyamopsis tetragonolabous)

Energy Technology Data Exchange (ETDEWEB)

Eldaw, Ganal Elawad [Department of Food Science and Technology, Faculty of Agriculture, University of Khartoum, Khartoum (Sudan)

1998-06-01

Guar seed components of three genotypes (HFG53, HFG182, HFG363), are hull (13.4-14%), germ (43.3-44.2%) and endosperm (36.0-40%). The proximate composition of guar seed in mean values is moisture (11.3{+-}0.01%), crude protein (29.10{+-}0.01%), crude fat (1.58{+-}0.01%), crude fibre (9.01{+-}0.01%) and carbohydrates by difference. The endosperm analysis showed mean values for moisture (6.18{+-}0.03%), ash (1.35{+-}0.03%), crude protein (4.41{+-}0.0%), crude fat (0.30{+-}0.0%), crude fibre (1.55{+-}0.01%) and carbohydrates (0.41{+-}0.04%). The micro and macro-elements quantities of the endosperm of the three genotypes are as follows: Zn (29-44 mg/kg), fe (52-112 mg/kg), Cu (2.6-3.8 mg/kg), Pb (0.34-0.38 mg/kg) and As (0.24 mg/kg), Na (0.1-0.5%), K (0.70-0.95%), Ca (0.30-0.37%) and Mg (0.11%), respectively. The micro and macro elements of germ and hull are also reported in this study. The Ost wald relative viscosity of guar gum behave Newtonian up to 0.5% mg/ml. The relative viscosity linear curves have high coefficient of correlation (r=0.87, 0.82-1.05, and 0.99) for gum of endosperm, respectively. Redwood measures kinematic viscosity of guar gum for the three genotypes at varying temperatures 40-80 degree. Heat stability of HFG53 is the best among the three genotypes guar gum. the high contamination in gum lowered the heat stability of the three genotypes. Brookfield method shows a high rate of dispersability for HFG363 followed by HFG182 and HFG53. The comparative study of the effect of purification on guar gum viscosities measured by Ostwald within the three genotypes show high coefficient of correlation. The influence of salt concentration 1.0, 1.5 and 2.0% on heat stability of commercial guar gum show high viscosities. Sugar influence in heated guar gum solution 0.5% (200 mesh) gives a high viscosity increase than 80 mesh with 5, 10 and 15% added sugar. The effect of combined salt-sugar on commercial guar gives increased viscosity than the control.

A study of guar seed and guar gum properties (Cyamopsis tetragonolabous)

International Nuclear Information System (INIS)

Eldaw, Ganal Elawad

1998-06-01

Guar seed components of three genotypes (HFG53, HFG182, HFG363), are hull (13.4-14%), germ (43.3-44.2%) and endosperm (36.0-40%). The proximate composition of guar seed in mean values is moisture (11.3±0.01%), crude protein (29.10±0.01%), crude fat (1.58±0.01%), crude fibre (9.01±0.01%) and carbohydrates by difference. The endosperm analysis showed mean values for moisture (6.18±0.03%), ash (1.35±0.03%), crude protein (4.41±0.0%), crude fat (0.30±0.0%), crude fibre (1.55±0.01%) and carbohydrates (0.41±0.04%). The micro and macro-elements quantities of the endosperm of the three genotypes are as follows: Zn (29-44 mg/kg), fe (52-112 mg/kg), Cu (2.6-3.8 mg/kg), Pb (0.34-0.38 mg/kg) and As (0.24 mg/kg), Na (0.1-0.5%), K (0.70-0.95%), Ca (0.30-0.37%) and Mg (0.11%), respectively. The micro and macro elements of germ and hull are also reported in this study. The Ost wald relative viscosity of guar gum behave Newtonian up to 0.5% mg/ml. The relative viscosity linear curves have high coefficient of correlation (r=0.87, 0.82-1.05, and 0.99) for gum of endosperm, respectively. Redwood measures kinematic viscosity of guar gum for the three genotypes at varying temperatures 40-80 degree. Heat stability of HFG53 is the best among the three genotypes guar gum. the high contamination in gum lowered the heat stability of the three genotypes. Brookfield method shows a high rate of dispersability for HFG363 followed by HFG182 and HFG53. The comparative study of the effect of purification on guar gum viscosities measured by Ostwald within the three genotypes show high coefficient of correlation. The influence of salt concentration 1.0, 1.5 and 2.0% on heat stability of commercial guar gum show high viscosities. Sugar influence in heated guar gum solution 0.5% (200 mesh) gives a high viscosity increase than 80 mesh with 5, 10 and 15% added sugar. The effect of combined salt-sugar on commercial guar gives increased viscosity than the control

Synthesis and Characterisation of Eight Isomeric Bis(2-pyridyloxynaphthalenes

Directory of Open Access Journals (Sweden)

Peter J. Steel

2006-09-01

Full Text Available Eight isomeric bis(2-pyridyloxynaphthalenes have been prepared from reactions of 2-bromopyridine with the appropriate dihydroxynaphthalene and the products fully characterised by 1- and 2-D NMR spectroscopy.

Gum acacia mitigates genetic damage in adenine-induced chronic renal failure in rats.

Science.gov (United States)

Ali, B H; Al Balushi, K; Al-Husseini, I; Mandel, P; Nemmar, A; Schupp, N; Ribeiro, D A

2015-12-01

Subjects with chronic renal failure (CRF) exhibit oxidative genome damage, which may predispose to carcinogenesis, and Gum acacia (GumA) ameliorates this condition in humans and animals. We evaluated here renal DNA damage and urinary excretion of four nucleic acid oxidation adducts namely 8-oxoguanine (8-oxoGua), 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), 8-oxoguanosine (8-oxoGuo) and 8-hydroxy-2-deoxyguanisone (8-OHdg) in rats with adenine (ADE)-induced CRF with and without GumA treatment. Twenty-four rats were divided into four equal groups and treated for 4 weeks. The first group was given normal food and water (control). The second group was given normal food and GumA (15% w/v) in drinking water. The third group was fed powder diet containing adenine (ADE) (0·75% w/w in feed). The fourth group was fed like in the third group, plus GumA in drinking water (15%, w/v). ADE feeding induced CRF (as measured by several physiological, biochemical and histological indices) and also caused a significant genetic damage and significant decreases in urinary 8-oxo Gua and 8-oxoGuo, but not in the other nucleic acids. However, concomitant GumA treatment reduced the level of genetic damage in kidney cells as detected by Comet assay and significantly reversed the effect of adenine on urinary 8-oxoGuo. Treatment with GumA is able to mitigate genetic damage in renal tissues of rats with ADE-induced CRF. © 2015 Stichting European Society for Clinical Investigation Journal Foundation.

Gum chewing improves adolescents’ math performance in an SAT preparatory course

Science.gov (United States)

The purpose of the current study was to determine the effect of gum chewing on students’ performance in a preparatory course for the Scholastic Aptitude Test (SAT). A total of 182 adolescents enrolled in an SAT preparatory class were randomized into one of two treatments: 1) gum chewing condition (G...

Evaluation of the suspening property of Grewia gum in zinc oxide ...

African Journals Online (AJOL)

The suspending property of grewia gum in zinc oxide suspension was evaluated. The gum was extracted by maceration, filtration, precipitation and drying techniques. It was used at 0.3 to 1% w/v as a suspending agent for zinc oxide. Sodiumcarboxymethylcellulose (SCMC) and tragacanth were used as basis for ...

Combined Function of Brønsted and Lewis Acidity in the Zeolite-Catalyzed Isomerization of Glucose to Fructose in Alcohols

DEFF Research Database (Denmark)

Shunmugavel, Saravanamurugan; Riisager, Anders; Taarning, Esben

2016-01-01

Glucose conversion via fructose to useful chemicals and fuels has attracted considerable attention. Isomerization of glucose to fructose can proceed along several different reaction pathways involving different sugar intermediates and isomeric forms. Presently, the roles of the substrate isomeric...

Formation, isomerization, and derivatization of keggin tungstoaluminates.

Science.gov (United States)

Jennifer J. Cowan; Alan J. Bailey; Robert A. Heintz; Bao T. Do; Kenneth I. Hardcastle; Craig L. Hill; Ira A. Weinstock

2001-01-01

Trends in the stability of ¥á and ©¬-Keggin heteropolytungstates of the second-row main-group heteroatoms Al(III), Si(IV), and P(V) are elaborated by data that establish the roles of kinetic and thermodynamic control in the formation and isomerization of Keggin tungstoaluminates. Slow, room-temperature co-...

Evaluation of accelerated stability test conditions for medicated chewing gums.

Science.gov (United States)

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

2013-10-01

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

Sugar-free chewing gum and dental caries: a systematic review

Directory of Open Access Journals (Sweden)

Steffen Mickenautsch

2007-04-01

Full Text Available OBJECTIVE: To appraise existing evidence for a therapeutic / anti-cariogenic effect of sugar-free chewing gum for patients. METHOD: 9 English and 2 Portuguese databases were searched using English and Portuguese keywords. Relevant articles in English, German, Portuguese and Spanish were included for review. Trials were excluded on lack of randomisation, control group, blinding and baseline data, drop out rate >33%, no statistical adjustment of baseline differences and no assessment of clinically important outcomes. Reviews were excluded on lack of information, article selection criteria, search strategy followed, search keywords, searched databases or lack of study-by-study critique tables. In cases of multiple reports from the same study, the report covering the longest period was included. Two reviewers independently reviewed and assessed the quality of accepted articles. RESULTS: Thirty-nine articles were included for review. Thirty were excluded and 9 accepted. Of the 9 accepted, 2 trials of reasonable and good evidence value did not demonstrate any anti-cariogenic effect of sugar-free chewing gum. However, 7 articles, with 1 of strong, and 6 of good evidence value, demonstrated anti-cariogenic effects of chewing Sorbitol, Xylitol or Sorbitol/Xylitol gum. This effect can be ascribed to saliva stimulation through the chewing process, particularly when gum is used immediately after meals; the lack of sucrose and the inability of bacteria to metabolize polyols into acids. Conclusion: The evidence suggests that sugar-free chewing gum has a caries-reducing effect. Further well-designed randomised trials are needed to confirm these findings.

Naturalistic assessment of demand for cigarettes, snus, and nicotine gum.

Science.gov (United States)

Stein, Jeffrey S; Wilson, A George; Koffarnus, Mikhail N; Judd, Michael C; Bickel, Warren K

2017-01-01

Behavioral economic measures of demand provide estimates of tobacco product abuse liability and may predict effects of policy-related price regulation on consumption of existing and emerging tobacco products. In the present study, we examined demand for snus, a smokeless tobacco product, in comparison to both cigarettes and medicinal nicotine. We used both a naturalistic method in which participants purchased these products for use outside the laboratory, as well as laboratory-based self-administration procedures. Cigarette smokers (N = 42) used an experimental income to purchase their usual brand of cigarettes and either snus or gum (only one product available per session) across a range of prices, while receiving all products they purchased from one randomly selected price. In a separate portion of the study, participants self-administered these products during laboratory-based, progressive ratio sessions. Demand elasticity (sensitivity of purchasing to price) was significantly greater for snus than cigarettes. Elasticity for gum was intermediate between snus and cigarettes but was not significantly different than either. Demand intensity (purchasing unconstrained by price) was significantly lower for gum compared to cigarettes, with no significant difference observed between snus and cigarettes. Results of the laboratory-based, progressive ratio sessions were generally discordant with measures of demand elasticity, with significantly higher "breakpoints" for cigarettes compared to gum and no significant differences between other study products. Moreover, breakpoints and product purchasing were generally uncorrelated across tasks. Under naturalistic conditions, snus appears more sensitive to price manipulation than either cigarettes or nicotine gum in existing smokers.

Protein-free cress seed (Lepidium sativum) gum: Physicochemical characterization and rheological properties

DEFF Research Database (Denmark)

Razmkhah, Somayeh; Razavi, Seyed Mohammad Ali; Mohammadifar, Mohammad Amin

2016-01-01

Protein-free cress seed gum (PFCSG) was obtained by precipitation of crude cress seed gum (CSG) withethanol followed by treatment with protease. Molecular weight, moisture, ash and uronic acids contentdecreased after elimination of protein. Elimination of protein improved significantly rheologica...

PHYSICOCHEMICAL AND gabonensis GUM EXUDATES A ...

African Journals Online (AJOL)

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fundamental property of a gum therefore is i water solubility ... tion November, 2017. Journal of ... ly or after mechanical incision of the .... and structure of liquid water. .... On the other hand, the strength .... the mineral/aqueous solution interface.".

Synthesis, physico-chemical and biomedical applications of sulfated Aegle marmelos gum: Green chemistry approach

Directory of Open Access Journals (Sweden)

Manish Jindal

2017-05-01

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

K isomerism and collectivity in neutron-rich rare-earth isotopes

Science.gov (United States)

Patel, Zena

Neutron-rich rare-earth isotopes were produced by in-flight fission of 238U ions at the Radioactive Isotope Beam Factory (RIBF), RIKEN, Japan. In-flight fission of a heavy, high-intensity beam of 238U ions on a light target provides the cleanest secondary beams of neutron-rich nuclei in the rare-earth region of isotopes. In-flight fission is advantageous over other methods of nuclear production, as it allows for a secondary beam to be extracted, from which the beam species can be separated and identified. The excited states of nuclei are studied by delayed isomeric or beta-delayed gamma-ray spectroscopy. New K isomers were found in Sm (Z=62), Eu (Z=63), and Gd (Z=64) isotopes. The key results are discussed here. Excited states in the N=102 isotones 166Gd and 164Sm have been observed following isomeric decay for the first time. The K-isomeric states in 166Gd and 164Sm are due to 2-quasiparticle configurations. Based on the decay patterns and potential energy surface calculations, including beta6 deformation, both isomers are assigned a (6-) spin-parity. The half-lives of the isomeric states have been measured to be 950(60)ns and 600(140)ns for 166Gd and 164Sm respectively. Collective observables are discussed in light of the systematics of the region, giving insight into nuclear shape evolution. The decrease in the ground state band energies of 166Gd and 164Sm (N=102) compared to 164Gd and 162Sm (N=100) respectively, presents evidence for the predicted deformed shell closure at N=100. A 4-quasiparticle isomeric state has been discovered in 160Sm: the lightest deformed nucleus with a 4-quasiparticle isomer to date. The isomeric state is assigned an (11+) spin-parity with a measured half-life of 1.8(4)us. The (11+) isomeric state decays into a rotational band structure, based on a (6-) v5/2-[523] ⊗ v7/2+[633] bandhead, determined from the extracted gK-gR values. Potential energy surface and blocked BCS calculations were performed in the deformed midshell region

The study of a new short-life isomeric state in 38K

International Nuclear Information System (INIS)

Iordachescu, A.

1976-01-01

The 38 K nucleus having a protone and neutron hole coupled with a 40 Ca inert core has a structure analysed easily by the shell model. A new short life, high spin and highly excited isomeric state of the 38 K nucleus has been studied in detail using this model. Theoretical aspects connected with static and dynamic electromagnetic moments of the nucleus state, with the magnetic moment of the nucleus and the selection rules according to the isotopic spin are presented in the case of gamma transitions. Experimentallz/ presented in the case of gamma transitions. Experimentally, it has been used a combination between a natural pulsation of the cyclotron beam and an external pulsation by electrostatic deflexion, thus obtaining a pulsation beam of 12-26 MeV alpha particles. As targets, a series of chemical chlorine combinations have been utilized, the isomeric state being obtained by the reaction 35 Cl(α,n) 38 K, having the isomeric level (1fsub(7/2))sub(7+)sup(2). (author)

High spin states and isomeric decays in doubly-odd {sup 208}Fr

Energy Technology Data Exchange (ETDEWEB)

Kanjilal, D.; Bhattacharya, S.; Goswami, A.; Kshetri, R.; Raut, R. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India); Saha, S., E-mail: satyajit.saha@saha.ac.i [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India); Bhowmik, R.K.; Gehlot, J.; Muralithar, S.; Singh, R.P. [Inter University Accelerator Centre, New Delhi 110067 (India); Jnaneswari, G. [Department of Physics, Andhra University, Vishakhapatnam 530003 (India); Mukherjee, G. [Variable Energy Cyclotron Centre, Kolkata 700064 (India); Mukherjee, B. [Department of Physics, Visva Bharati, Santiniketan 731235 (India)

2010-10-15

Neutron deficient isotopes of francium (Z=87, N{approx}121-123) as excited nuclei were produced in the fusion-evaporation reaction: {sup 197}Au({sup 16}O, xn) {sup 213-x}Fr at 100 MeV. The {gamma} rays from the residues were observed through the high sensitivity Germanium Clover detector array INGA. The decay of the high spin states and the isomeric states of the doubly-odd {sup 208}Fr nuclei, identified from the known sequence of ground state transitions, were observed. The half-lives of the E{sub {gamma}=}194(2) keV isomeric transition, known from earlier observations, was measured to be T{sub 1/2}=233(18) ns. A second isomeric transition at E{sub {gamma}=}383(2) keV and T{sub 1/2}=33(7) ns was also found. The measured half-lives were compared with the corresponding single particle estimates, based on the level scheme obtained from the experiment.

intra-species variation of the properties of gum exudates from Acacia

African Journals Online (AJOL)

a

The results show that significant inter-species variation of the properties of the gum exudates from the two species exist, whereas only some parameters show significant intra-species variation. The specific optical rotations of the gum exudates have been found to vary from ---43.2o to ---52o for Acacia senegal var. senegal ...

Deformation Mechanisms of Gum Metals Under Nanoindentation

Science.gov (United States)

Sankaran, Rohini Priya

Gum Metal is a set of multi-component beta-Ti alloys designed and developed by Toyota Central R&D Labs in 2003 to have a nearly zero shear modulus in the direction. After significant amounts of cold-work (>90%), these alloys were found to have yield strengths at a significant fraction of the predicted ideal strengths and exhibited very little work hardening. It has been speculated that this mechanical behavior may be realized through an ideal shear mechanism as opposed to conventional plastic deformation mechanisms, such as slip, and that such a mechanism may be realized through a defect structure termed "nanodisturbance". It is furthermore theorized that for near ideal strength to be attained, dislocations need to be pinned at sufficiently high stresses. It is the search for these defects and pinning points that motivates the present study. However, the mechanism of plastic deformation and the true origin of specific defect structures unique to gum metals is still controversial, mainly due to the complexity of the beta-Ti alloy system and the heavily distorted lattice exhibited in cold worked gum metals, rendering interpretation of images difficult. Accordingly, the first aim of this study is to clarify the starting as-received microstructures of gum metal alloys through conventional transmission electron microscopy (TEM) and aberration-corrected high resolution scanning transmission electron microscopy with high-angle annular dark field detector (HAADF-HRSTEM) imaging. To elucidate the effects of beta-stability and starting microstructure on the deformation behavior of gum metals and thus to provide adequate context for potentially novel deformation structures, we investigate three alloy conditions: gum metal that has undergone solution heat treatment (STGM), gum metal that has been heavily cold worked (CWGM), and a solution treated alloy of nominal gum metal composition, but leaner in beta-stabilizing content (ST Ref-1). In order to directly relate observed

Want to block earworms from conscious awareness? B(u)y gum!

Science.gov (United States)

Beaman, C Philip; Powell, Kitty; Rapley, Ellie

2015-01-01

Three experiments examine the role of articulatory motor planning in experiencing an involuntary musical recollection (an "earworm"). Experiment 1 shows that interfering with articulatory motor programming by chewing gum reduces both the number of voluntary and the number of involuntary-unwanted-musical thoughts. This is consistent with other findings that chewing gum interferes with voluntary processes such as recollections from verbal memory, the interpretation of ambiguous auditory images, and the scanning of familiar melodies, but is not predicted by theories of thought suppression, which assume that suppression is made more difficult by concurrent tasks or cognitive loads. Experiment 2 shows that chewing the gum affects the experience of "hearing" the music and cannot be ascribed to a general effect on thinking about a tune only in abstract terms. Experiment 3 confirms that the reduction of musical recollections by chewing gum is not the consequence of a general attentional or dual-task demand. The data support a link between articulatory motor programming and the appearance in consciousness of both voluntary and unwanted musical recollections.

Impacts of daily intakes on the isomeric profiles of perfluoroalkyl substances (PFASs) in human serum.

Science.gov (United States)

Shan, Guoqiang; Wang, Zhi; Zhou, Lianqiu; Du, Pin; Luo, Xiaoxiao; Wu, Qiannian; Zhu, Lingyan

2016-01-01

Perfluoroalkyl substances (PFASs) have been well studied in human daily intake for assessment of potential health risks. However, little is known about the isomeric compositions of PFASs in daily intake and their impacts on isomeric profiles in humans. In this study, we investigated the occurrence of PFASs with isomeric analysis in various human exposure matrices including foodstuffs, tap water and indoor dust. Perfluorooctanesulfonate (PFOS) and/or perfluorooctanoate (PFOA) were predominant in these exposure matrices collected in Tianjin, China. In fish and meat, linear (n-) PFOA was enriched with a percentage of 92.2% and 99.6%, respectively. Although n-PFOS was higher in fish (84.8%) than in technical PFOS (ca. 70%), it was much lower in meat (63.1%) and vegetables (58.5%). Dietary intake contributed >99% of the estimated daily intake (EDI) for the general population. The isomeric profiles of PFOA and PFOS in human serum were predicted based on the EDI and a one-compartment, first-order pharmacokinetic model. The isomeric percentage of n-PFOA in the EDI (98.6%) was similar to that in human serum (predicted: 98.2%, previously measured: 99.7%) of Tianjin residents. The results suggest direct PFOA intake plays an important role in its isomeric compositions in humans. For PFOS, the predicted n-PFOS (69.3%) was much higher than the previously measured values (59.2%) in human serum. This implies that other factors, such as indirect exposure to PFOS precursors and multiple excretion pathways, may contribute to the lower percentage of n-PFOS in humans than of technical PFOS. Copyright © 2016 Elsevier Ltd. All rights reserved.

Electron beam irradiation effects on xanthan gum. Rheological aspects

International Nuclear Information System (INIS)

Vieira, F.F.; Del Mastro, N.L.

2001-01-01

The paper describes the application of electron beam irradiation to xanthum gum as used as ingredient by the food or cosmetics industry in order to establish their radiosensitivity. The edible powder of xanthum gum samples were irradiated in 1mm thick layers of Petri dishes covered by a transparent PVC of films using an EB accelerator Dynamitron (Radiation Dynamics Inc.) model JOB 188, dose rate 11.17 kGy/s, 0.637 MeV, 1.78 mA, 5 kGy per passage, 3.36 m min -1 with doses of 5, 10, 20 and 50kGy. One % aqueous solutions from irradiated and non-irradiated xanthum gum were prepared and the radiation effects were measured following viscosity changes at 25 deg. C using a Brookfield viscometer; model DVIII, spindel L, with Rheocalc software. Viscosity measurements were performed according to our previous experience and the results are the mean of at least 3 experiments

Cardiovascular responses in humans to experimental chewing of gums of different consistencies.

Science.gov (United States)

Farella, M; Bakke, M; Michelotti, A; Marotta, G; Martina, R

1999-10-01

Although the cardiovascular effects of exercise have been extensively investigated in man, little attention has been paid to such responses to jaw muscle activity. The aim here was to investigate the general cardiovascular effects of chewing activity in a single-blind, cross-over design. Ten healthy individuals performed one of the following chewing tasks in four separate sessions: chewing a very hard gum, chewing a moderately hard gum, chewing a soft gum, and "empty chewing" without a bolus. Unilateral chewing of gum or empty chewing was performed for 20 min on the participant's most convenient chewing side at a constant rate of 80 cycles/min. In each session, heart rate and arterial blood pressure were recorded together with electromyographic activity in the masseter and anterior temporalis muscles on the chewing side. Ratings of perceived masticatory fatigue were recorded with visual analogue scales. The heart rate and blood pressure were significantly increased (ANOVA; p chewing tasks and the increases were, in parallel with the muscle activity, more pronounced the harder the gum. With the very hard gum, heart rate increased by up to 11 beats/min, the systolic blood pressure was 14 mmHg (1.9kPa) higher, and the diastolic blood pressure was 11 mmHg (1.5kPa) higher. The perceived fatigue was proportional to the level of muscle activity. After 10 min of recovery from exercise, heart rate and arterial blood pressures were slightly but still significantly elevated. The results demonstrate that chewing is associated with general circulatory effects proportional to the bolus resistance.

A system to measure isomeric state half-lives in the 10 ns to 10 μs range

Energy Technology Data Exchange (ETDEWEB)

Toufen, D. L., E-mail: dennis@if.usp.br [Institute of Physics, University of São Paulo, C.P. 66318, 05315-970 São Paulo, São Paulo (Brazil); Federal Institute of Education, Science and Technology of São Paulo - IFSP, 07115-000 Guarulhos, São Paulo (Brazil); Allegro, P. R. P.; Medina, N. H.; Oliveira, J. R. B.; Cybulska, E. W.; Seale, W. A.; Ribas, R. V. [Institute of Physics, University of São Paulo, C.P. 66318, 05315-970 São Paulo, São Paulo (Brazil); Linares, R. [Fluminense Federal University, 24220-900 Niterói, Rio de Janeiro (Brazil); Silveira, M. A. G. [Universitary Center of FEI, 09850-901 São Bernardo do Campo, São Paulo (Brazil)

2014-07-15

The Isomeric State Measurement System (SISMEI) was developed to search for isomeric nuclear states produced by fusion-evaporation reactions. The SISMEI consists of 10 plastic phoswich telescopes, two lead shields, one NaI(Tl) scintillation detector, two Compton suppressed HPGe γ-ray detectors, and a cone with a recoil product catcher. The new system was tested at the 8 UD Pelletron tandem accelerator of the University of São Paulo with the measurement of two known isomeric states: {sup 54}Fe, 10{sup +} state (E = 6527.1 (11) keV, T{sub 1/2} = 364(7) ns) and the 5/2{sup +} state of {sup 19}F (E = 197.143 (4) keV, T{sub 1/2} = 89.3 (10) ns). The results indicate that the system is capable of identifying delayed transitions, of measuring isomeric state lifetimes, and of identifying the feeding transitions of the isomeric state through the delayed γ-γ coincidence method. The measured half-life for the 10{sup +} state was T{sub 1/2} = 365(14) ns and for the 5/2{sup +} state, 100(36) ns.

A system to measure isomeric state half-lives in the 10 ns to 10 μs range

Science.gov (United States)

Toufen, D. L.; Allegro, P. R. P.; Medina, N. H.; Oliveira, J. R. B.; Cybulska, E. W.; Seale, W. A.; Linares, R.; Silveira, M. A. G.; Ribas, R. V.

2014-07-01

The Isomeric State Measurement System (SISMEI) was developed to search for isomeric nuclear states produced by fusion-evaporation reactions. The SISMEI consists of 10 plastic phoswich telescopes, two lead shields, one NaI(Tl) scintillation detector, two Compton suppressed HPGe γ-ray detectors, and a cone with a recoil product catcher. The new system was tested at the 8 UD Pelletron tandem accelerator of the University of São Paulo with the measurement of two known isomeric states: 54Fe, 10+ state (E = 6527.1 (11) keV, T1/2 = 364(7) ns) and the 5/2+ state of 19F (E = 197.143 (4) keV, T1/2 = 89.3 (10) ns). The results indicate that the system is capable of identifying delayed transitions, of measuring isomeric state lifetimes, and of identifying the feeding transitions of the isomeric state through the delayed γ-γ coincidence method. The measured half-life for the 10+ state was T1/2 = 365(14) ns and for the 5/2+ state, 100(36) ns.

The Effect of Persian Gums and Tragacanth on Texture and Sensory Characteristics of Non-Gluten ‎Cakes

Directory of Open Access Journals (Sweden)

Afrooz Ghasemi

2017-08-01

Methods: The effect of addition of Persian gums, Tragacanth, and a combination of both of these compounds at levels of 0.5, 1, and 1.5% on texture, color, and sensory characteristics of these cakes was evaluated in this study. Results: The results showed that solidity and viscosity factors were elevated by addition of gum to cake. Using of gums in cakes leads to moisture maintenance inside the cake texture and thus improves mastication property. Furthermore, the results of porosity evaluation showed that addition of Persian gums and Tragacanth decreases the size and increases the number of gas cells inside the cake texture and improves porosity. The best porosity was related to the sample containing 1.5% Persian gum and Tragacanth. The treatment that contained 0.75% Persian gum and 0.75% Tragacanth had the highest acceptability among consumers. Conclusions: Results showed that Persian and Tragacanth gums, whether used independently or in combination, can improve the quality and organoleptic characteristics of gluten-free cakes.

Structural and spectral comparisons between isomeric benzisothiazole and benzothiazole based aromatic heterocyclic dyes

Science.gov (United States)

Wang, Yin-Ge; Wang, Yue-Hua; Tao, Tao; Qian, Hui-Fen; Huang, Wei

2015-09-01

A pair of isomeric heterocyclic compounds, namely 3-amino-5-nitro-[2,1]-benzisothiazole and 2-amino-6-nitrobenzothiazole, are used as the diazonium components to couple with two N-substituted 4-aminobenzene derivatives. As a result, two pairs of isomeric aromatic heterocyclic azo dyes have been produced and they are structurally and spectrally characterized and compared including single-crystal structures, electronic spectra, solvatochromism and reversible acid-base discoloration, thermal stability and theoretically calculations. It is concluded that both benzisothiazole and benzothiazole based dyes show planar molecular structures and offset π-π stacking interactions, solvatochromism and reversible acid-base discoloration. Furthermore, benzisothiazole based aromatic heterocyclic dyes exhibit higher thermal stability, larger solvatochromic effects and maximum absorption wavelengths than corresponding benzothiazole based ones, which can be explained successfully by the differences of their calculated isomerization energy, dipole moment and molecular band gaps.

Scope and mechanism in palladium-catalyzed isomerizations of highly substituted allylic, homoallylic, and alkenyl alcohols.

Science.gov (United States)

Larionov, Evgeny; Lin, Luqing; Guénée, Laure; Mazet, Clément

2014-12-03

Herein we report the palladium-catalyzed isomerization of highly substituted allylic alcohols and alkenyl alcohols by means of a single catalytic system. The operationally simple reaction protocol is applicable to a broad range of substrates and displays a wide functional group tolerance, and the products are usually isolated in high chemical yield. Experimental and computational mechanistic investigations provide complementary and converging evidence for a chain-walking process consisting of repeated migratory insertion/β-H elimination sequences. Interestingly, the catalyst does not dissociate from the substrate in the isomerization of allylic alcohols, whereas it disengages during the isomerization of alkenyl alcohols when additional substituents are present on the alkyl chain.

Natural gums of plant origin as edible coatings for food industry applications.

Science.gov (United States)

Saha, Anuradha; Tyagi, Shvetambri; Gupta, Rajinder K; Tyagi, Yogesh K

2017-12-01

Natural plant-based gums and their derivatives are widely utilized in food industries, however, their applications as edible coatings to extend fresh fruits and vegetable shelf-life has been explored recently. These natural polymeric polysaccharides have many advantages as compared to synthetic polymers, because they are biodegradable, nontoxic, economical and easily available in the environment. Natural gums can also be semi synthetically modified to produce derivatives, which can easily compete with the synthetic preservatives available on the food market. In this review, the recent developments in the use of natural gums and their derivatives as edible coatings have been explored and discussed.

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

Science.gov (United States)

Momin, Munira; Pundarikakshudu, K

2004-09-24

The objective of the present study is to develop colon targeted drug delivery systems for sennosides using guar gum as a carrier. Matrix tablets containing various proportions of guar gum were prepared by wet granulation technique using starch paste as a binder. The tablets were evaluated for content uniformity and in vitro drug release study as per BP method. T(50) % value from the dissolution studies was taken for selecting the best formulation. Guar gum matrix tablets released 4-18% sennosides in the physiological environment of gastrointestinal tract depending on the proportion of the guar gum used in the formulation. The matrix tablets containing 50% of guar gum were found to be suitable for targeting of sennosides for local action in the colon. Compared to tablets having 30% and 40% of guar gum, those with 50% guar gum gave better T(50)% (11.7 h) le and fewer amounts (5-8%) of drug release in upper GIT. These tablets with 50% guar gum released 43% and 96% sennosides with and without rat caecal fluids. This suggests the susceptibility of matrix to the colonic micro flora. The similarity factor (f2 value) for drug release with and without rat caecal fluids was found to be less than 30. When hydroxy propyl methylcellulose phthalate (10%) was used as a coat material on the matrix tablets, the initial loss of 5-8% sennosides in stomach could be completely averted. These tablets showed no change in physical appearance, content and dissolution profile upon storage at 45 degrees C / 75% relative humidity for 3 months. The results of our study indicates that matrix tablets containing 50% guar gum and coated with 10% hydroxy propyl methylcellulose phthalate are most suitable for drugs like sennosides which are mainly active in the lower GIT.

Rhythm and amplitude of rhythmic masticatory muscle activity during sleep in bruxers - comparison with gum chewing.

Science.gov (United States)

Matsuda, Shinpei; Yamaguchi, Taihiko; Mikami, Saki; Okada, Kazuki; Gotouda, Akihito; Sano, Kazuo

2016-07-01

The aim of this study was to elucidate characteristics of rhythmic masticatory muscle activity (RMMA) during sleep by comparing masseteric EMG (electromyogram) activities of RMMA with gum chewing. The parts of five or more consecutive phasic bursts in RMMA of 23 bruxers were analyzed. Wilcoxon signed-rank test for matched pairs and Spearman's correlation coefficient by the rank test were used for statistical analysis. Root mean square value of RMMA phasic burst was smaller than that during gum chewing, but correlates to that of gum chewing. The cycle of RMMA was longer than that of gum chewing due to the longer burst duration of RMMA, and variation in the cycles of RMMA was wider. These findings suggest that the longer but smaller EMG burst in comparison with gum chewing is one of the characteristics of RMMA. The relation between size of RMMA phasic bursts and gum chewing is also suggested.

Study of the isomeric states of 66As

International Nuclear Information System (INIS)

Czajkowski, S.; Blank, B.; Andriamonje, S.; Attallah, F.; Boue, F.; Davi, F.; Del Moral, R.; Fleury, A.; Musquere, A.; Pravikoff, M.S.; Dufour, J-P; Grzywacz, R.; Janas, Z.; Karny, M.; Pfuetzner, M.; Donzaud, C.; Grewe, A.; Heinz, A.; Junghans, A.; Lewitowicz, M.; Sauvestre, J-E.

1997-01-01

The most neutron-deficient isotopes in the N = Z region are an important source of information on the neutron-proton interaction far off stability. The isotopes in this region are characterized by an extreme sensitivity of the deformation to the isospin variations. Here the structure of deformed shells are favoring the high spin states the lifetime of which being sufficient long to be observed after flight time of the order of the microsecond. The study of the decay of this isomeric states permits to approach the structure of the first excited levels of this isotopes. Recent experiments at GANIL with the SISSI - LISE 3 spectrometer were performed to study the neutron deficient nucleus 66 As. This nucleus was produced in the fragmentation of 70 MeV/u 78 Kr primary beam in a nickel target. Two new isomeric states have been observed. From the observed γ transitions a decay scheme is proposed

Microwave Irradiated Copolymerization of Xanthan Gum with Acrylamide for Colonic Drug Delivery

Directory of Open Access Journals (Sweden)

Fozia Anjum

2015-01-01

Full Text Available Xanthan gum (XG is a polysaccharide produced by Xanthomonas campestris. The aim of the present study was to modify the xanthan by hydrolysis and grafting with acrylamide through microwave irradiation for different time intervals. Pure xanthan was partially hydrolyzed via enzymatic and chemical treatments followed by optional grafting. Proximate composition analysis, moisture content, and carbohydrate, protein, lipid, and fiber contents were determined. The morphological characteristics, structural composition, functional groups, and heat resistance of the crude, hydrolyzed, and grafted gum were evaluated using SEM, XRD, FTIR spectroscopy, and TGA. Morphological studies revealed that xanthan was broken down into smaller fragments as a result of hydrolysis and became somewhat smoother. Thermal analysis studies indicated a larger heat tolerance in the grafted xanthan relative to that of the native and hydrolyzed gums. Xanthan bound to a triamcinolone drug was evaluated in the context of controlled drug release. Controlled drug release correlated well with the exposure time to microwaves used to graft the gum.

Effect of Guar Gum with Sorbitol Coating on the Properties and Oil Absorption of French Fries.

Science.gov (United States)

Jia, Bo; Fan, Daming; Li, Jinwei; Duan, Zhenhua; Fan, Liuping

2017-12-13

This paper investigated the effects of guar gum with sorbitol coating on the oil absorption of French fries by combined dye oil methods, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The results showed that pretreatment of blanching with calcium ions and coating with guar gum and sorbitol could significantly reduce the structural oil (STO) and penetrated surface oil (PSO) of French fries and have no negative effects on its texture and also effectively control the final moisture content ( p French fries with guar gum and sorbitol reduced by 50.8%, 33.1% and 30.6%, respectively. CLSM photographs confirmed that STO significantly reduced after coating with guar gum and sorbitol, followed by PSO. In the process of frying, the coatings of guar gum or guar gum with sorbitol could effectively prevent oil from infiltrating the potato tissue, which can be seen in the SEM photographs. The barrier properties of French fries were enhanced by coating guar gum, and sorbitol was added to avoid pores and cracks. Blanching with calcium ion can significantly reduce the final moisture content of coating French fries.

Oxidation of cashew tree gum exudate polysaccharide with TEMPO reagent

International Nuclear Information System (INIS)

Cunha, Pablyana L.R.; Maciel, Jeanny S.; Paula, Regina C.M. de; Feitosa, Judith P.A.; Sierakowski, Maria Rita

2007-01-01

Cashew gum (CG), an exudate polysaccharide from Anacardium occidentale trees, was oxidized with TEMPO reagent and the product (CGOX) characterized by spectroscopic techniques (FTIR and NMR), chromatographic analyses (HPLC and GPC), viscosity measurements and thermal analysis (TGA). The yield of the reaction product was 96%. The uronic acid content in starting gum (7.2 m%) was increased to 36 m%. The degree of oxidation based on free galactose and glucose units was 68%. NMR data show that oxidation occurred preferentially at primary carbons of galactose units. High degradation degree after oxidation was estimated by the difference on the expected and observed η CGOX /η CG ratio. The presence of organic and inorganic impurities in the new polyelectrolyte was detected by TGA. A less thermally stable cashew gum is formed after the oxidation with TEMPO based on initial decomposition temperature and IPDT. (author)

Isomerization of β-carotene by titanium tetrachloride catalyst

Indian Academy of Sciences (India)

TECS

2007-05-04

May 4, 2007 ... antioxidant because of the presence of a long chain of conjugated carbon-carbon double bonds. ... such as extraction, chromatography etc. It has been reported that the chlorinated solvents can promote isomerization of trans conjugated polyenes such as β-carotene during extraction.5. Also, the isomeriza-.

Excitation of isomeric states 1h11/2 in (γ, n) reactions

International Nuclear Information System (INIS)

Tonchev, A.P.; Gangrskij, Yu.P.; Belov, A.G.

1995-01-01

The cross sections of (γ, n) reactions were measured for ground and isomeric states 1h 11/2 in 16 isotopes of Pd, Cd, Sn, Te, Ba, Ce, Nd and Sm. The energy of γ-rays was placed in the region of Giant Dipole Resonance. An activation method of measurements has been used. IR dependence of neutron and proton number in nucleus was detected and of excitation energy of residual nucleus as well. Different factors influencing the values of the isomeric ratios are discussed. 20 refs., 5 figs., 2 tabs

Temperature dependency of the interaction between xanthan gum and sage seed gum: An interpretation of dynamic rheology and thixotropy based on creep test.

Science.gov (United States)

Razavi, Seyed M A; Behrouzian, Fataneh; Alghooneh, Ali

2017-10-01

The viscoelastic (transient and dynamic) and time-dependent rheological behaviors of XG (xanthan gum), SSG (sage seed gum) and their blends at various ratios (1-3, 1-1, and 3-1 SSG-XG) and temperatures (10, 30, and 50C) were investigated using creep and recovery analyses. The creep compliance was converted to stress relaxation data; then, the structural kinetic model satisfactorily fitted the time-dependent relaxation modulus. Furthermore, dynamic rheology of mixtures was investigated using creep analyses. The most important contribution of the Maxwell spring to deformation (53.51%), was that corresponding to the SSG at 50C and the most important contribution of the Maxwell dashpot to the maximum deformation, were those corresponding to the XG (61.44%) and 1-3 SSG-XG (58.91%) samples both at 50C. The breakdown rate constant ( α) of the crosslinked gum structure in SSG and 3-1 SSG-XG under the application of external shear stress increases with temperature from 10 to 50C in the range of 0.14-0.32 (1/s) and 0.14-0.24 (1/s), respectively, whereas other dispersions showed the reverse trend. Among all dispersions, only XG and 1-3 SSG-XG demonstrated crossover frequency at 9.95 and 31.47 rad/s, respectively, at 50C, indicative of the lowest entanglement density for 1-3 SSG-XG. The greatest interaction between SSG and XG occurred for 3-1 ratio at 50C, which was confirmed by the Han curves. Hydrocolloid blends, particularly those consisting of xanthan gum and a galactomannan from new source can provide a range of attractive textural properties. Rheological studies contribute to the description of the molecular structure and prediction of the structural changes during their manufacturing processes. Sage seed gum (SSG), as a polyelectrolyte galactomannan, has a great potential to exert stabilizing, thickening, gelling and binding properties in food, cosmetics, and pharmaceutical systems. Therefore, we elaborate the interactions between SSG and xanthan gum and also the

Structure of xanthan gum and cell ultrastructure at different times of alkali stress.

Science.gov (United States)

Luvielmo, Márcia de Mello; Borges, Caroline Dellinghausen; Toyama, Daniela de Oliveira; Vendruscolo, Claire Tondo; Scamparini, Adilma Regina Pippa

2016-01-01

The effect of alkali stress on the yield, viscosity, gum structure, and cell ultrastructure of xanthan gum was evaluated at the end of fermentation process of xanthan production by Xanthomonas campestris pv. manihotis 280-95. Although greater xanthan production was observed after a 24h-alkali stress process, a lower viscosity was observed when compared to the alkali stress-free gum, regardless of the alkali stress time. However, this outcome is not conclusive as further studies on gum purification are required to remove excess sodium, verify the efficiency loss and the consequent increase in the polymer viscosity. Alkali stress altered the structure of xanthan gum from a polygon-like shape to a star-like form. At the end of the fermentation, early structural changes in the bacterium were observed. After alkali stress, marked structural differences were observed in the cells. A more vacuolated cytoplasm and discontinuities in the membrane cells evidenced the cell lysis. Xanthan was observed in the form of concentric circles instead of agglomerates as observed prior to the alkali stress. Copyright © 2015 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Chewing gum and lozenges as delivery systems for noscapine

DEFF Research Database (Denmark)

Norgaard Jensen, L.; Christrup, Lona Louring; Menger, N.

1991-01-01

Chewing gum and lozenges were evaluated as delivery systems for noscapine with the aim of developing improved antitussive preparations. The formulations studied were prepared with both the water-soluble hydrochloride salt of noscapine and with the poorly soluble embonate salt and noscapine free...... base. The release characteristics of the preparations were evaluated both in vitro and in vivo, and their taste properties examined. Only the formulations containing noscapine base were without any appreciable taste. Chewing gum containing this compound showed, however, a low level of drug release both...

The role of time on task performance in modifying the effects of gum chewing on attention

NARCIS (Netherlands)

Tucha, Lara; Simpson, William

Recent research examined the effects of chewing gum on attention and reported a significant interaction of gum chewing with time. Using a crossover within-subject design, the present study examined the effect of gum chewing on sustained attention in healthy adults over a period of 30 min. The

[Isomeric derivatives of lupinine and epilupinine--organophosphorus inhibitors of cholinesterases].

Science.gov (United States)

Basova, N E; Kormilitsyn, B N; Perchenok, A Iu; Rosengart, E V; Saakov, V S; Suvorov, A A

2012-01-01

The isomeric-structure analysis data of anticholinesterase action of organophosphorous inhibitors with similar structure help in the search of specific effectors and detection of differences in reactivity of various animals' enzymes. This study compared the data of efficacy in respect of 4 mammal and 5 arthropoda cholinesterase preparations for 26 quinolizidine inhibitors, which molecules contain both the isomeric unbranched and branched alkoxyl radicals in the phosphoryl group, and the epimeric lupinine and epilupinine derivatives in the leaving group. The changes in the alkoxyl radical structure of inhibitor molecules act on their efficacy only with respect to the mammal enzymes ("group" inhibitor specificity). The differences between lupinine and epilupinine derivatives were revealed. Highly specific inhibitors of different enzymes were detected among the tested compounds.

Determination of the production rate of low intensity isomeric transitions

International Nuclear Information System (INIS)

Lakosi, L.; Veres, A.; Tam, N.C.; Pavlicsek, I.

1992-01-01

Flat 2π and cylindrical 4π multiwire proportional counters were built for counting for low energy internal conversion electrons from the nuclear isomers 83m Kr, 103m Rh and 189m Os, induced by irradiation with high intensity 60 Co and 4 MeV bremsstrahlung sources. The β-decay of 176m Lu was recorded by a plastic scintillator. In this way higher sensitivities were attained than by detecting γ-rays or characteristic X-rays associated with the isomeric transitions, and the excitation of 189m Os by low energy 137 Cs and 300 kV X-ray sources also became detectable. Comparatively large isomeric activities produced by linac irradiation were standardizing by a Ge spectrometer for calibrating proportional and scintillation counting. (orig.)

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

Science.gov (United States)

Soparkar, P; Newman, M B

2001-07-01

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.

cis-trans Isomerization of silybins A and B

Czech Academy of Sciences Publication Activity Database

Novotná, Michaela; Gažák, Radek; Biedermann, David; Di Meo, F.; Marhol, Petr; Kuzma, Marek; Bednárová, Lucie; Fuksová, Kateřina; Trouillas, P.; Křen, Vladimír

-, č. 10 (2014), s. 1047-1063 ISSN 1860-5397 R&D Projects: GA ČR GAP207/10/0288; GA MŠk LH13097; GA MŠk(CZ) LD13041 Institutional support: RVO:61388971 ; RVO:61388963 Keywords : isomerization * silibinin * silybin Subject RIV: CC - Organic Chemistry Impact factor: 2.762, year: 2014

The Impact of Maltitol-Sweetened Chewing Gum on the Dental Plaque Biofilm Microbiota Composition

Directory of Open Access Journals (Sweden)

Bart J. F. Keijser

2018-03-01

Full Text Available Background: The oral cavity harbors a complex microbial ecosystem, intimately related to oral health and disease. The use of polyol-sweetened gum is believed to benefit oral health through stimulation of salivary flow and impacting oral pathogenic bacteria. Maltitol is often used as sweetener in food products. This study aimed to establish the in vivo effects of frequent consumption of maltitol-sweetened chewing gum on the dental plaque microbiota in healthy volunteers and to establish the cellular and molecular effects by in vitro cultivation and transcriptional analysis.Results: An intervention study was performed in 153 volunteers, randomly assigned to three groups (www.trialregister.nl; NTR4165. One group was requested to use maltitol gum five times daily, one group used gum-base, and the third group did not use chewing gum. At day 0 and day 28, 24 h-accumulated supragingival plaque was collected at the lingual sites of the lower jaw and the buccal sites of the upper jaw and analyzed by 16S ribosomal rRNA gene sequencing. At day 42, 2 weeks after completion of the study, lower-jaw samples were collected and analyzed. The upper buccal plaque microbiota composition had lower bacterial levels and higher relative abundances of (facultative aerobic species compared to the lower lingual sites. There was no difference in bacterial community structure between any of the three study groups (PERMANOVA. Significant lower abundance of several bacterial phylotypes was found in maltitol gum group compared to the gum-base group, including Actinomyces massiliensis HOT 852 and Lautropia mirabilis HOT 022. Cultivation studies confirmed growth inhibition of A. massiliensis and A. johnsonii by maltitol at levels of 1% and higher. Transcriptome analysis of A. massiliensis revealed that exposure to maltitol resulted in changes in the expression of genes linked to osmoregulation, biofilm formation, and central carbon metabolism.Conclusion: The results showed that

The Impact of Maltitol-Sweetened Chewing Gum on the Dental Plaque Biofilm Microbiota Composition.

Science.gov (United States)

Keijser, Bart J F; van den Broek, Tim J; Slot, Dagmar E; van Twillert, Lodewic; Kool, Jolanda; Thabuis, Clémentine; Ossendrijver, Michel; van der Weijden, Fridus A; Montijn, Roy C

2018-01-01

Background: The oral cavity harbors a complex microbial ecosystem, intimately related to oral health and disease. The use of polyol-sweetened gum is believed to benefit oral health through stimulation of salivary flow and impacting oral pathogenic bacteria. Maltitol is often used as sweetener in food products. This study aimed to establish the in vivo effects of frequent consumption of maltitol-sweetened chewing gum on the dental plaque microbiota in healthy volunteers and to establish the cellular and molecular effects by in vitro cultivation and transcriptional analysis. Results: An intervention study was performed in 153 volunteers, randomly assigned to three groups (www.trialregister.nl; NTR4165). One group was requested to use maltitol gum five times daily, one group used gum-base, and the third group did not use chewing gum. At day 0 and day 28, 24 h-accumulated supragingival plaque was collected at the lingual sites of the lower jaw and the buccal sites of the upper jaw and analyzed by 16S ribosomal rRNA gene sequencing. At day 42, 2 weeks after completion of the study, lower-jaw samples were collected and analyzed. The upper buccal plaque microbiota composition had lower bacterial levels and higher relative abundances of (facultative) aerobic species compared to the lower lingual sites. There was no difference in bacterial community structure between any of the three study groups (PERMANOVA). Significant lower abundance of several bacterial phylotypes was found in maltitol gum group compared to the gum-base group, including Actinomyces massiliensis HOT 852 and Lautropia mirabilis HOT 022. Cultivation studies confirmed growth inhibition of A. massiliensis and A. johnsonii by maltitol at levels of 1% and higher. Transcriptome analysis of A. massiliensis revealed that exposure to maltitol resulted in changes in the expression of genes linked to osmoregulation, biofilm formation, and central carbon metabolism. Conclusion: The results showed that chewing itself

The Impact of Maltitol-Sweetened Chewing Gum on the Dental Plaque Biofilm Microbiota Composition

Science.gov (United States)

Keijser, Bart J. F.; van den Broek, Tim J.; Slot, Dagmar E.; van Twillert, Lodewic; Kool, Jolanda; Thabuis, Clémentine; Ossendrijver, Michel; van der Weijden, Fridus A.; Montijn, Roy C.

2018-01-01

Background: The oral cavity harbors a complex microbial ecosystem, intimately related to oral health and disease. The use of polyol-sweetened gum is believed to benefit oral health through stimulation of salivary flow and impacting oral pathogenic bacteria. Maltitol is often used as sweetener in food products. This study aimed to establish the in vivo effects of frequent consumption of maltitol-sweetened chewing gum on the dental plaque microbiota in healthy volunteers and to establish the cellular and molecular effects by in vitro cultivation and transcriptional analysis. Results: An intervention study was performed in 153 volunteers, randomly assigned to three groups (www.trialregister.nl; NTR4165). One group was requested to use maltitol gum five times daily, one group used gum-base, and the third group did not use chewing gum. At day 0 and day 28, 24 h-accumulated supragingival plaque was collected at the lingual sites of the lower jaw and the buccal sites of the upper jaw and analyzed by 16S ribosomal rRNA gene sequencing. At day 42, 2 weeks after completion of the study, lower-jaw samples were collected and analyzed. The upper buccal plaque microbiota composition had lower bacterial levels and higher relative abundances of (facultative) aerobic species compared to the lower lingual sites. There was no difference in bacterial community structure between any of the three study groups (PERMANOVA). Significant lower abundance of several bacterial phylotypes was found in maltitol gum group compared to the gum-base group, including Actinomyces massiliensis HOT 852 and Lautropia mirabilis HOT 022. Cultivation studies confirmed growth inhibition of A. massiliensis and A. johnsonii by maltitol at levels of 1% and higher. Transcriptome analysis of A. massiliensis revealed that exposure to maltitol resulted in changes in the expression of genes linked to osmoregulation, biofilm formation, and central carbon metabolism. Conclusion: The results showed that chewing itself

Analysis of Optimal Process Flow Diagrams of Light Naphtha Isomerization Process by Mathematic Modelling Method

OpenAIRE

Chuzlov, Vyacheslav Alekseevich; Molotov, Konstantin

2016-01-01

An approach to simulation of hydrocarbons refining processes catalytic reactors. The kinetic and thermodynamic research of light naphtha isomerization process was conducted. The kinetic parameters of hydrocarbon feedstock chemical conversion on different types of platinum-content catalysts was established. The estimation of efficiency of including different types of isomerization technologies in oil refinery flow diagram was performed.

Implications of Partial Conjugation of Whey Protein Isolate to Durian Seed Gum through Maillard Reactions: Foaming Properties, Water Holding Capacity and Interfacial Activity

Directory of Open Access Journals (Sweden)

Bahareh Tabatabaee Amid

2013-12-01

Full Text Available 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.

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

Science.gov (United States)

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

2005-04-01

Many patients on haemodialysis (HD) therapy suffer from a dry mouth and xerostomia. This can be relieved by mechanical and gustatory stimulation or palliative care. The aim of this crossover study was to investigate the effect and preferences of a sugar-free chewing gum (Freedent White) and a xanthan gum-based artificial saliva (Xialine) in the management of xerostomia in chronic HD patients. Sixty-five HD patients participated in a 6-week crossover trial. The artificial saliva was rated significantly lower than the chewing gum for effectiveness, taste and a global assessment. No preference differences were found for gender and age, although older subjects rated the artificial saliva with a higher mark. Thirty-nine subjects (60%) preferred chewing gum, 15% (n=10) preferred the artificial saliva. Therefore, both chewing gum and artificial saliva could play an important role in the palliative care of xerostomia in HD patients.

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

Science.gov (United States)

Kumar, Shobhit; Gupta, Satish Kumar

2012-01-01

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.

Effect of Angum gum in combination with tragacanth gum on rheological and sensory properties of ketchup.

Science.gov (United States)

Komeilyfard, Ahmadreza; Fazel, Mohammad; Akhavan, Hamidreza; Mousakhani Ganjeh, Alireza

2017-04-01

The aim of this study was to evaluate the effect of Angum gum (AnG) alone and in combination with tragacanth gum (TG) on the stability, texture, sensory, and rheological properties of tomato ketchup. AnG, TG, and Angum gum and tragacanth gum mixture (AnGT; 1:1 ratio) were added at levels of 0.5, 1, and 1.5%. Ten tomato ketchup formulations were produced: control (without hydrocolloid), AnG (0.5-1.5%), TG (0.5-1.5%), AnGT (0.5-1.5%). It was observed that the hydrocolloids addition to tomato ketchup significantly decreased the Bostwick consistency value and serum separation at 2200, 5000, and 8800 g. Textural properties of tomato ketchup by using back extrusion test and particle size analysis were significantly increased with hydrocolloid addition. All tomato ketchup formulations showed shear thinning behavior and the addition of hydrocolloids increased apparent viscosity. The power law and Herschel-Bulkley models were successfully fitted with experimental data. The flow behavior indices of Herschel-Bulkley and power law models were changed in the range of 0.19-0.24 and 0.14-0.30, respectively. The consistency coefficients of these models were in the range of 16.31-79.57 and 11.19-146.06 Pa s n , respectively. The storage modulus (G') of all tomato ketchups was higher than the loss modulus (G″). Hydrocolloid addition showed no significant effect on the color indices (L*, a*, b*, hue angle, chroma, and total color differences) of tomato ketchup. The overall acceptability of 1.5% AnG, 0.5% TG, 1 and 1.5% AnGT were significantly higher than other samples. Therefore, AnG can be used alone and in combination with TG as stabilizer in tomato ketchup. The consistency of tomato ketchup is an important attribute from both engineering and consumer viewpoints. It was observed that addition of TG, AnG, and AnGT to tomato ketchups significantly decreased their Bostwick consistency values and their serum separation. In addition, hydrocolloid addition showed no significant effect

Oxidation of cashew tree gum exudate polysaccharide with TEMPO reagent

Energy Technology Data Exchange (ETDEWEB)

Cunha, Pablyana L.R.; Maciel, Jeanny S.; Paula, Regina C.M. de; Feitosa, Judith P.A. [Universidade Federal do Ceara, Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica; Sierakowski, Maria Rita [Universidade Federal do Parana, Curitiba, PR (Brazil). Dept. de Quimica]. E-mail: judith@dqoi.ufc.br

2007-07-01

Cashew gum (CG), an exudate polysaccharide from Anacardium occidentale trees, was oxidized with TEMPO reagent and the product (CGOX) characterized by spectroscopic techniques (FTIR and NMR), chromatographic analyses (HPLC and GPC), viscosity measurements and thermal analysis (TGA). The yield of the reaction product was 96%. The uronic acid content in starting gum (7.2 m%) was increased to 36 m%. The degree of oxidation based on free galactose and glucose units was 68%. NMR data show that oxidation occurred preferentially at primary carbons of galactose units. High degradation degree after oxidation was estimated by the difference on the expected and observed {eta}{sub CGOX}/{eta}{sub CG} ratio. The presence of organic and inorganic impurities in the new polyelectrolyte was detected by TGA. A less thermally stable cashew gum is formed after the oxidation with TEMPO based on initial decomposition temperature and IPDT. (author)

Diabetes, Gum Disease, and Other Dental Problems

Science.gov (United States)

... Diabetes, Sexual, & Bladder Problems Diabetes, Gum Disease, & Other Dental Problems How can diabetes affect my mouth? Too ... What if my mouth is sore after my dental work? A sore mouth is common after dental ...

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

Science.gov (United States)

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

2005-02-01

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

Discussion of isomeric ratios in (p, n) and (d, 2n) reaction

Energy Technology Data Exchange (ETDEWEB)

Bakhshiyan, T. M., E-mail: tiruhi44@mail.ru [Yerevan State University (Armenia)

2016-01-15

Isomeric ratios (IR) in the (p, n) and (d, 2n) reactions are considered. The dependence of IR values on the projectile type and energy, the target- and product-nucleus spin, the spin difference between the isomeric and ground states of products, and the product mass number is discussed. The isomeric ratios for 46 product nuclei (from {sup 44m,g}Sc to {sup 127m,g}Xe) obtained in reactions where target and product nuclei have identical mass numbers were calculated at energies from the reaction threshold to 50 MeV (with a step of ΔE = 1 MeV). The calculations in question were performed with the aid of the TALYS 1.4 code package. The calculated IR values were compared with their experimental counterparts available from the literature (EXFOR database). In the majority of cases, the calculated IR values agree well with the experimental data in question. It is noteworthy that the IR values obtained in (d, 2n) reactions are substantially greater than those in (p, n) reactions.

Effect of Chewing Bicarbonate-containing Sugar-free Gum on the Salivary pH: An in vivo Study.

Science.gov (United States)

Ballal, Raksha K; Bhat, Sham S; Ramdas, Shenoy Shailesh; Ballal, Shrinidhi

2016-01-01

The objective of the study was to evaluate the effect of chewing gum on the salivary pH and to compare the effect of chewing bicarbonate-containing sugar-free gum on salivary pH against that of standard sugar-free gum. The experiment was carried out on 30 volunteers aged 20-22 years (mean age = 21 years) who fulfilled the inclusion criteria. The test gum was sugar-free greenmint-flavored bicarbonate-containing gum and the standard control was sugar-free spearmint-flavored gum. The pH was measured immediately using pH strips. According to statistical analysis, the mean salivary pH of the bicarbonate gum at 0, 5, 10, 15 and 20 minutes is 6.9713, 6.5667, 6.4267, 6.3867 and 6.3233 respectively. There is decrease in pH from 0 to 20 minutes. According to Bonferroni, there was no significant difference in pH from 0 to 20 minutes, 10 to 20 minutes and 15 to 20 minutes, but there was a significant difference in salivary pH from 5 to 20 minutes (p = 0.014). The mean salivary pH of the standard gum at 0, 5, 10, 15 and 20 minutes is 6.8767, 6.6067, 6.4200, 6.4027 and 6.3000 respectively. There is decrease in pH from 0 to 20 minutes. According to Bonferroni, there was no significant difference in pH from 0 to 20 minutes, 5 to 20 minutes, 10 to 20 minutes and 15 to 20 minutes. Thus, the higher salivary pH achieved with chewing bicarbonate gum compared with a standard sugar-free gum may have important oral health implications. How to cite this article: Ballal RK, Bhat SS, Ramdas SS, Ballal S. Effect of Chewing Bicarbonate-containing Sugar-free Gum on the Salivary pH: An in vivo Study. Int J Clin Pediatr Dent 2016;9(1):35-38.

Development of postcompressional textural tests to evaluate the mechanical properties of medicated chewing gum tablets with high drug loadings.

Science.gov (United States)

Al Hagbani, Turki; Nazzal, Sami

2018-02-01

Medicated chewing gum tablets (CGTs) represent a unique platform for drug delivery. Loading directly compressible gums with high concentrations of powdered medication, however, results in compacts with hybrid properties between a chewable gum and a brittle tablet. The aim of the present study was to develop textural tests that can identify the point at which CGTs begin to behave like a solid tablet upon drug incorporation. Curcumin (CUR) CGTs made with Health in gum were prepared with increasing CUR load from 0 to 100% and were characterized for their mechanical properties by a single-bite (knife) and a two-bite tests. From each test several parameters were extracted and correlated with drug loading. In the single-bite test, the change in the resistance of the compacts to plastic deformation was found to give a definitive guide on whether they behave as gums or tablets. A more in depth analysis of the impact of CUR loading on the chewability of the CGTs was provided by the two-bite test where CUR loading was found to have a nonlinear impact on the mechanical properties of compacts. An upper limit of 10% was found to yield compacts with gum-like properties, which were abolished at higher CUR loads. The textural test procedure outlined in this study are expected to assist those involved in the formulation of medicated gums for pharmaceutical applications in making an informed decision on the impact of drug loading on gum behavior before proceeding with clinical testing. There is a growing interest in utilizing medicated chewing gums for drug delivery, especially those made using directly compressible gum bases, such as Health in gum. Directly compressing a gum base with high amounts of solid drug powder, however, poses a challenge as it may result in compressed compacts with hybrid properties between a chewing gum and a hard tablet. Currently, official Pharmacopeias do not specify a testing procedure for the estimation of the mechanical and textural properties of

Special features of isomeric ratios in nuclear reactions induced by various projectile particles

Energy Technology Data Exchange (ETDEWEB)

Danagulyan, A. S.; Hovhannisyan, G. H., E-mail: hov-gohar@ysu.am; Bakhshiyan, T. M.; Martirosyan, G. V. [Yerevan State University (Armenia)

2016-05-15

Calculations for (p, n) and (α, p3n) reactions were performed with the aid of the TALYS-1.4 code. Reactions in which the mass numbers of target and product nuclei were identical were examined in the range of A = 44–124. Excitation functions were obtained for product nuclei in ground and isomeric states, and isomeric ratios were calculated. The calculated data reflect well the dependence of the isomeric ratios on the projectile type. A comparison of the calculated and experimental data reveals, that, for some nuclei in a high-spin state, the calculated data fall greatly short of their experimental counterparts. These discrepancies may be due to the presence of high-spin yrast states and rotational bands in these nuclei. Calculations involving various level-density models included in the TALYS-1.4 code with allowance for the enhancement of collective effects do not remove the discrepancies in the majority of cases.

The amino acid composition of the proteinaceous component of gum tragacanth (Asiatic Astragalus spp.).

Science.gov (United States)

Anderson, D M; Howlett, J F; McNab, C G

1985-01-01

Six Iranian and seven Turkish samples of commercial gum tragacanth, and a sample of Turkish 'gum traganton', have been studied. Their nitrogen content varied from 0.17 to 0.58%. Their amino acid compositions are characterized by the presence of very large but variable proportions of hydroxyproline and substantial proportions of serine, proline and valine. The data presented may be useful for extending the current specifications for identity and purity, at present based solely on polysaccharide parameters, for gum tragacanth (E413).

investigation of the effect of zinc oxide-modified gum arabic on polar ...

African Journals Online (AJOL)

BARTH EKWUEME

Gum Arabic solution, a water-based adhesive, was modified with zinc oxide filler and the formulation was applied on wood, ceramic, glass and textile substrates. A strip of paper was used as a common adherent to all the substrates. Zinc oxide increased the viscosity of 30wt% gum Arabic solution and increased bond ...

Investigation of the effect of zinc oxide-modified gum Arabic on polar ...

African Journals Online (AJOL)

Gum Arabic solution, a water-based adhesive, was modified with zinc oxide filler and the formulation was applied on wood, ceramic, glass and textile substrates. A strip of paper was used as a common adherent to all the substrates. Zinc oxide increased the viscosity of 30wt% gum Arabic solution and increased bond ...

Analysis of Optimal Process Flow Diagrams of Light Naphtha Isomerization Process by Mathematic Modelling Method

Directory of Open Access Journals (Sweden)

Chuzlov Vjacheslav

2016-01-01

Full Text Available An approach to simulation of hydrocarbons refining processes catalytic reactors. The kinetic and thermodynamic research of light naphtha isomerization process was conducted. The kinetic parameters of hydrocarbon feedstock chemical conversion on different types of platinum-content catalysts was established. The estimation of efficiency of including different types of isomerization technologies in oil refinery flow diagram was performed.

Chewing gum does not induce context-dependent memory when flavor is held constant.

Science.gov (United States)

Overman, Amy A; Sun, Justin; Golding, Abbe C; Prevost, Darius

2009-10-01

This study examined the effect of chewing gum on memory when flavor is held constant. Four separate groups of participants (total n=101) completed a word recall task. At learning and recall, participants either chewed a piece of gum or sucked a sweet. Each participant completed the memory task twice, once with abstract words and once with concrete words. A significant effect of word type (concrete vs. abstract) was found, however recall performance was not improved by matched oral activity at learning and recall. The results cast further doubt on the ability of chewing gum to induce context-dependent memory effects.

Tuliposides and tulipalins in tulip Gum

NARCIS (Netherlands)

Lubbe, A.; Verpoorte, R.; Gude, H.; Dijkema, M.H.G.E.

2013-01-01

Gummosis in tulip bulbs is one of the negative effects of ethylene gas that is produced during storage by Fusarium-infected bulbs on the healthy bulbs. Several aspects of the gummosis process, like the factors inducing it, the underlying carbohydrate metabolism and the composition of the gum have

Catalyst compositions useful for olefin isomerization and disproportionation

International Nuclear Information System (INIS)

Drake, C.A.

1987-01-01

A process is described for the double bond isomerization of an aliphatic olefinic hydrocarbon feed which comprises contacting the feed under isomerization conditions with a catalyst prepared by: (a) impregnating an alumina support having a surface area of at least 200 m/sup 2//g and a pore volume of at least 0.45 cm/sup 3//g with: 1 up to 20 wt. % of at least one magnesium compound convertible to the oxide, based on the weight of support and calculated as the metal; 0 up to 5 wt. % of at least one alkali metal compound convertible to the oxide, based on the weight of support and calculated as the metal; and 0 up to 5 wt. % of at least one zirconium compound convertible to the oxide, based on the weight of support and calculated as the metal; and (b) heating the alumina support impregnated in accordance with step (a) in an oxygen-containing atmosphere under conditions suitable to convert at least a portion of the magnesium, alkali metal, and zirconium compounds to the oxide form

Determination of trace elements in chewing gum by neutron activation analysis

International Nuclear Information System (INIS)

Dietz, M.L.

1990-01-01

Six trace elements of nutritional or toxicological interest (Al, Ca, Cl, Mn, Na and Sr) were determined in three different brands of chewing gum by instrumental neutron activation analysis. For the particular brands of gum examined, none of the detected elements was found to be present at a level representing a substantial contribution to the total dietary intake of the element for an American adult. (author) 11 refs.; 3 tabs

Want to block earworms from conscious awareness?B(u)y gum!

OpenAIRE

Beaman, C. Philip; Powell, Kitty; Rapley, Ellie

2015-01-01

Three experiments examine the role of articulatory motor planning in experiencing an involuntary musical recollection (an “earworm”). Experiment 1 shows that interfering with articulatory motor programming by chewing gum reduces both the number of voluntary and the number of involuntary—unwanted—musical thoughts. This is consistent with other findings that chewing gum interferes with voluntary processes such as recollections from verbal memory, the interpretation of ambiguous auditory images,...

Application of Neem Gum for Aqueous Film Coating of Ciprofloxacin Tablets

OpenAIRE

A P Kulkarni; Y R Shaikh; MH GR Dehghan

2013-01-01

Summary. At present the pharmaceutical industry and academia are focusing on the use of natural materials and resources for development of pharmaceutical product. In previous study, neem gum (NG), obtained from Azadirachata indica plant revealed satisfactory film forming ability. The present study evaluates the application potential of neem gum, as an aqueous film coating material, using ciprofloxacin hydrchloride (drug) as a model drug. Initial study of physical mixture indicated absence of ...

Market-driven production with transaction costs outlook: Gum arabic collection systems in Senegal

NARCIS (Netherlands)

Mujawamariya, G.; Burger, C.P.J.; Haese, D' M.F.C.

2015-01-01

Low returns from marketing of non-timber forest products such as gum arabic restrict the collection of these products. A hypothesis is tested that access to good markets motivates collectors to harvest and market gum arabic. Analyses of the choice of participation in group marketing, sale price,

Validating the applicability of the GUM procedure

Science.gov (United States)

Cox, Maurice G.; Harris, Peter M.

2014-08-01

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

Properties of a color-changeable chewing gum used to evaluate masticatory performance.

Science.gov (United States)

Hama, Yohei; Kanazawa, Manabu; Minakuchi, Shunsuke; Uchida, Tatsuro; Sasaki, Yoshiyuki

2014-04-01

To clarify the basic properties of a color-changeable chewing gum to determine its applicability to evaluations of masticatory performance under different types of dental status. Ten participants with natural dentition aged 26-30 years chewed gum that changes color during several chewing strokes over five repetitions. Changes in color were assessed using a colorimeter, and then L*, a*, and b* values in the CIELAB color system were quantified. Relationships between chewing progression and color changes were assessed using regression analysis and the reliability of color changes was assessed using intraclass correlation coefficients. We then measured 42 dentate participants (age, 22-31 years) and 47 complete denture wearers (age, 44-90 years) to determine the detectability of masticatory performance under two types of dental status. Regression between the number of chewing strokes and the difference between two colors was non-linear. The intraclass correlation coefficients were highest between 60 and 160 chewing strokes. Dentate and edentulous groups significantly differed (Wilcoxon rank sum test) and values were widely distributed within each group. The color of the chewing gum changed over a wide range, which was sufficient to evaluate the masticatory performance of individuals with natural dentition and those with complete dentures. Changes in the color values of the gum reliably reflected masticatory performance. These findings indicate that the color-changeable chewing gum will be useful for evaluating masticatory performance under any dental status. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

New isomeric states in {sup 152,154,156}Nd produced by spontaneous fission of {sup 252}Cf

Energy Technology Data Exchange (ETDEWEB)

Gautherin, C.; Houry, M.; Korten, W.; Le Coz, Y.; Lucas, R.; Phan, X.H.; Theisen, C. [Commissariat l`Energie Atomique de Saclay, Gif sur Yvette (France). DSM/DAPINA/SPhN; Badimon, C.; Barreau, G.; Doan, T.P.; Pedemay, G. [Centre d`Etudes Nucleaires de Bordeaux-Gradignan, Domaine du Haut Vigneau, F-33175 Gradignan (France); Belier, G.; Girod, M.; Meot, V.; Peru, S. [Commissariat a l`Energie Atomique de Bruyeres-le-Chatel, DAM/SPN, BP12, F-91680 Bruyeres-le-Chatel (France); Astier, A.; Ducroux, L.; Meyer, M.; Redon, N. [Institut de Physique Nucleaire de Lyon, F-69622 Villeurbanne Cedex (France)

1998-04-01

Isomeric states have been observed in fission-fragments produced by spontaneous fission of {sup 252}Cf. These states are found in neutron rich nuclei of different structure and deformations. About 50 isomeric nuclei have been observed using coincidences between {gamma}-rays identified in EUROGAM II and fission fragments detected in photovoltaic cells (SAPhIR). Lifetimes in the range from 20 ns to 2{mu}s have been measured. Presented calculations based on HFB+D1S force on new measured isomeric states in the {sup 152,154,156}Nd show evidence for K-isomers. (orig.) With 8 figs., 27 refs.

Effect of gum arabic in an oral rehydration solution on recovery from diarrhea in rats.

Science.gov (United States)

Teichberg, S; Wingertzahn, M A; Moyse, J; Wapnir, R A

1999-10-01

It has been shown that gum arabic, a soluble fiber, enhances water, electrolyte, and glucose absorption from oral rehydration solutions in jejunal perfusion of healthy rats and in animals with theophylline-induced secretion or chronic osmotic-secretory diarrhea. This report concerns a study of the effectiveness of an oral rehydration solution supplemented with gum arabic, during recovery from chronic osmotic secretory diarrhea in free-living rats. Chronic diarrhea was induced in 60- to 80-g juvenile rats by providing a magnesium citrate-phenolphthalein solution as the sole fluid source for 7 days. This led to diarrhea characterized by dehydration, soft stools, increased cecal volume, decreased food and fluid intake and failure to gain weight. After 7 days of diarrhea, rats recovered for 24 hours with either tap water or an oral rehydration solution (90 mM Na, 111 mM glucose, 20 mM K, 80 mM chloride, 20 mM citrate) with or without 2.5 g/l gum arabic. Although all three solutions improved the diarrhea, optimal recovery from diarrhea was achieved with the gum arabic-supplemented oral rehydration solution. After 4 hours and 24 hours, rats drinking the gum arabic-supplemented solution gained more weight and had lower fecal output than rats receiving water or the rehydration solution without gum arabic. All three solutions normalized plasma osmolality after 24 hours. The positive effects of the gum arabic-supplemented rehydration solution on fluid and electrolyte absorption seen during jejunal perfusion also occurred during recovery from chronic osmotic secretory diarrhea, when free-living animals drank the solution ad libitum.

Antinociceptive activity of Astragalus gummifer gum (gum tragacanth) through the adrenergic system: A in vivo study in mice.

Science.gov (United States)

Bagheri, Seyyed Majid; Keyhani, Leila; Heydari, Mehrangiz; Dashti-R, Mohammad Hossein

2015-01-01

In Iranian traditional medicine, gum obtained from Astragalus gummifer and some other species of Astragalus was used as analgesic agent. In this study, we investigated the antinociceptive effect of several concentrations (125, 250, and 500 μg/kg body weight) of Astragalus gummifer gum (AGG) on thermal and acetic acid induced pain in mice. AGG was dissolved in distillated water and injected i.p to male mice 15 minute before the onset of experiment. Writhing and hot-plate tests were applied to study the analgesic effect of AGG and compared with that of diclofenac sodium (30 mg/kg, i.p.) or morphine (8 mg/kg, i.p). To investigate the mechanisms involved in antinociception, yohimbine, naloxone, glibenclamide, and theophylline were used in writhing test. These drugs were injected intraperitoneally 15 min before the administration of AGG. The number of writhes were counted in 30 minutes and analyzed. AGG exhibited a significant antinociceptive effect and the most effective dose of AGG was 500 μg/kg. The most maximum possible effect (%MPE) was observed (117.4%) 15 min after drug administration. The %inhibition of acetic acid-induced writhing in AGG 125, 250 and 500 was 47%, 50% and 54% vs %15 of control and 66.3% of diclofenac sodium group. The antinociceptive effect induced by this gum in the writhing test was reversed by the systemic administration of yohimbine (α2-adrenergic antagonist), but naloxone, glibenclamide, and theophylline did not reverse this effect. The findings of this study indicated that AGG induced its antinociceptive through the adrenergic system.

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

DEFF Research Database (Denmark)

Nøhr-Jensen, Lene; Damkier, Per; Bidstrup, Tanja Busk

2006-01-01

OBJECTIVE: The aim of this study was to investigate the pharmacokinetics of loratadine and its active metabolite desloratadine after single-dose administration of loratadine as a conventional tablet, orally disintegrating tablet (smelt tablet) and a chewing gum formulation with and without...... of medicated chewing gum without collection of saliva and a 30-mg portion of medicated chewing gum with collection of saliva. Blood samples were taken at predefined sampling points 0-24 h after medication, and the plasma concentrations of loratadine and desloratadine were determined by high-performance liquid...... chromatography. Each study period was separated by a wash-out period of at least 7 days. RESULTS: The mean dose-corrected area under the plasma concentration-time curve extrapolated to infinity AUC(0-infinity) for the chewing gum formulation was statistically significantly increased compared to the tablet...

[done no pages] An overview on applications of guar gum in food systems to modify structural properties

Directory of Open Access Journals (Sweden)

Biljana B. Popova

2017-01-01

Full Text Available Polysaccharides define as complex polymers composed of units interlinked with glycosidic bonds originated naturally. Polysaccharides are categorizing in several groups and among them, Gums are those with critical roles in food systems. Guar Gum is imparting softness, emulsification, stabilizing via its addition to formulas. This Gum is a fast soluble in cold water and can be active in a wide range of pH. The aim of this overview is giving an initial concept about guar gum and then convey to an introduction of its applications in food industries.

Enzymatic production of polysaccharides from gum tragacanth

DEFF Research Database (Denmark)

2014-01-01

Plant polysaccharides, relating to the field of natural probiotic components, can comprise structures similar to human milk oligosaccharides. A method for enzymatic hydrolysis of gum tragacanth from the bush-like legumes of the genus Astragalus, using a combination of pectin hydrolases...

Effect of chewing gums containing the probiotic bacterium Lactobacillus reuteri on oral malodour

DEFF Research Database (Denmark)

Keller, Mette K; Bardow, Allan; Jensdottir, Thorbjörg

2012-01-01

OBJECTIVE: To evaluate the effect of chewing gums containing probiotic bacteria on oral malodour. The null hypothesis was that no difference would be displayed compared with placebo gums. MATERIALS AND METHODS: Twenty-five healthy young adults with self-reported malodorous morning breath completed...... this randomized double-blind placebo-controlled cross-over trial. The design included run-in and wash-out periods interspersed by two intervention periods of 14 days each. The subjects were instructed to chew one gum in the morning and one in the evening containing either two strains of probiotic lactobacilli (L...... lower in the probiotic group compared with the placebo group (p chewing...

Potential benefits of chewing gum for the delivery of oral therapeutics and its possible role in oral healthcare

NARCIS (Netherlands)

Wessel, Stefan W.; van der Mei, Henny C.; Maitra, Amarnath; Dodds, Michael W. J.; Busscher, Henk J.

2016-01-01

Introduction: Over the years, chewing gum has developed from a candy towards an oral health-promoting nutraceutical. This review summarizes evidence for the oral health benefits of chewing gum, emphasizing identification of active ingredients in gum that facilitate prevention and removal of oral

Peptide models of protein metastable binding sites: competitive kinetics of isomerization and hydrolysis.

Science.gov (United States)

Khan, S A; Sekulski, J M; Erickson, B W

1986-09-09

alpha 2-Macroglobulin and the complement components C3 and C4 each contain a metastable binding site that is essential for covalent attachment. Two cyclic peptides are useful models of these unusual protein sites. Five-membered lactam 1 (CH3CO-Gly-Cys-Gly-Glu-Glp-Asn-NH2) contains an internal residue of pyroglutamic acid (Glp). Fifteen-membered thiolactone 2 (CH3CO-Gly-Cys-Gly-Glu-Glu-Asn-NH2 15-thiolactone) contains a thiol ester bond between Cys-2 and Glu-5. These isomeric hexapeptides are spontaneously interconverted in water. Competing with the two isomerization reactions are three reactions involving hydrolysis of 1 and 2. These five processes were found to occur simultaneously under physiologic conditions (phosphate-buffered saline, pH 7.3, 37 degrees C). Best estimates of the five rate constants for these apparent first-order reactions were obtained by comparing the observed molar percentages of peptides 1-4 with those calculated from a set of exponential equations. Both isomerization reactions (ring expansion of 1 to 2, k1 = 6.4 X 10(-5) s-1; ring contraction of 2 to 1, k-1 = 69 X 10(-5) s-1) proceeded faster than any of the hydrolysis reactions: alpha-cleavage of 1 with fragmentation to form dipeptide 3 (k2 = 3.3 X 10(-5) s-1), gamma-cleavage of 1 with ring opening to yield mercapto acid 4 (k3 = 0.35 X 10(-5) s-1), and hydrolysis of 2 with ring opening to give 4 (k4 = 1.9 X 10(-5) s-1). The isomerization rate ratio (k1/k-1 = 10.9) agreed with the isomer ratio at equilibrium (1:2 = 11 starting from 1 and 10 starting from 2). The alpha/gamma regioselectivity ratio (k2/k3 = 9.7) for hydrolysis of the internal Glp residue of 1 was consistent with results for model tripeptides. Part of the chemistry of the protein metastable binding sites can be explained by similar isomerization and hydrolysis reactions.

Effect of irradiation on functional properties of Gum Tragacanth

Directory of Open Access Journals (Sweden)

Neda Mollakhalili meybodi

2017-03-01

Full Text Available Background and objective: irradiation is a physical treatment in which products are exposed to ionized radiation such as gamma and x rays to improve the security and quality. Hydrocolloids are components that are used in food science to improve texture properties. Exposing to irradiation treatment may change structural and functional properties. By regard to the importance of irradiation on decontaminating of hydrocolloids in food application, the aim of this study is studying the effect of irradiation at different doses on functional properties of Gum Tragacanth in food application. Material and methods: effect of irradiation treatment was studied on the rheological properties, zeta potential, particle size distribution and surface tension of dispersion systems contained 0/5% w/ w gum tragacanth that is irradiated at different doses (0, 0.75. 3, 5 kGy. The effect of irradiation on rheological properties was monitored by rheometer. In order to monitor the effect of irradiation treatment on particle size distribution, zeta potential and surface tension, particle sizer, Brookhaven zeta plus and tensiometer sere used respectively. All treatments were performed three times and the data were analyzed by one way ANOVA. Significant differences between means were identified (P values < 0.05 using Duncan test. Results: Irradiation, change rheologiacal properties and particle size distribution of dispersion contained gum tragacanth. Irradiation treatment up to 0.75 kGy increase zeta potential, but irradiating at higher doses decrease it again. Results of studying parameters showed that irradiation changes the functional properties by affecting on structure. These changes depend on irradiation dose Conclusion: Gum tragacanth irradiation may improve the functional properties by affecting on structure.

Sulfomethylated graft copolymers of xanthan gum and polyacrylamide

Energy Technology Data Exchange (ETDEWEB)

Cottrell, I.W.; Empey, R.A.; Racciato, J.S.

1978-08-08

A water-soluble anionic graft copolymer of xanthan gum and polyacrylamide is described in which at least part of the amide function of the acrylamide portion of the copolymer is sulfomethylated and the xanthan gum portion of the copolymer is unreacted with formaldehyde. The copolymer is sulfomethylated by reaction with formaldehyde and sodium metabisulfite. The formaldehyde does not cause any appreciable cross-linking between hydroxyl groups of the xanthan moieties. The sulfomethylation of the acrylamido group takes place at temperatures from 35 to 70 C. The pH is 10 or higher, typically from 12 to 13. The degree of anionic character may be varied by adjusting the molar ratio of formaldehyde and sodium metabisulfite with respect to the copolymer. 10 claims.

Rosin-enabled ultraclean and damage-free transfer of graphene for large-area flexible organic light-emitting diodes

Science.gov (United States)

Zhang, Zhikun; Du, Jinhong; Zhang, Dingdong; Sun, Hengda; Yin, Lichang; Ma, Laipeng; Chen, Jiangshan; Ma, Dongge; Cheng, Hui-Ming; Ren, Wencai

2017-02-01

The large polymer particle residue generated during the transfer process of graphene grown by chemical vapour deposition is a critical issue that limits its use in large-area thin-film devices such as organic light-emitting diodes. The available lighting areas of the graphene-based organic light-emitting diodes reported so far are usually transfer method using rosin as a support layer, whose weak interaction with graphene, good solubility and sufficient strength enable ultraclean and damage-free transfer. The transferred graphene has a low surface roughness with an occasional maximum residue height of about 15 nm and a uniform sheet resistance of 560 Ω per square with about 1% deviation over a large area. Such clean, damage-free graphene has produced the four-inch monolithic flexible graphene-based organic light-emitting diode with a high brightness of about 10,000 cd m-2 that can already satisfy the requirements for lighting sources and displays.

Effect of Different Combinations of Gums and Emulsifiers on the Quality of Bread

International Nuclear Information System (INIS)

Haider, M. R.; Din, G. M. U.; Mehmood, A.; Hussain, A.; Nasir, M. U.

2016-01-01

A project was designed to evaluate the effect of different combinations of emulsifiers and gums on the quality of bread. Wheat variety AARI-11 was milled to get straight grade flour and mixed with the Emulsifiers (DMG and DATEM) and Gums (G.G and CMC) in a quantity of (0.3- 0.6 %). Both, straight grade flour as well as treated flour (combination with gums and emulsifiers) were subjected to proximate and rheological analysis. Results of the rheological study showed a significant change in water absorption, dough development time, dough stability time and dough viscosity i.e. W/A 61.33-62.93%, D.D.T 3.9-4.8 min, D.S.T 7-9.1 min and 818.33-950.00 BU, respectively. Breads prepared with both flours were also studied for their sensory attributes during storage after the interval of 24 h. The highest score was awarded to T1 (0.3% DATEM and 0.5% guar gum) on the bases of its excellent external attributes (colour of crust, volume, symmetry of form, evenness of bake and crust character) and internal characteristics (aroma, grain, texture, taste, mastication and colour of crumb). After the sensory and physicochemical analyses, it is concluded that with the addition of DATEM (0.3%) and guar gum (0.5%) resulted in good quality of bread. (author)

A comparison of the stability of beverage cloud emulsions formulated with different gum acacia- and starch-based emulsifiers.

Science.gov (United States)

Reiner, S J; Reineccius, G A; Peppard, T L

2010-06-01

The performance of several hydrocolloids (3 gum acacias, 1 modified gum acacia, and 3 modified starches) in stabilizing beverage emulsions and corresponding model beverages was investigated employing different core materials, emulsifier usage levels, and storage temperatures. Concentrated emulsions were prepared using orange terpenes or Miglyol 812 (comprising medium-chain triglycerides, MCT) weighted 1:1 with ester gum, stored at 25 or 35 degrees C, and analyzed on days 0, 1, and 3. On day 3, model beverages were made from each emulsion, stored at both temperatures, and analyzed weekly for 4 wk. Stability of concentrated emulsions was assessed by measuring mean particle size and by visual observations of ringing; beverage stability was judged similarly and also by loss of turbidity. Particle size measurements showed concentrated emulsions containing gum acacia or modified gum acacia with either core material were stable over 3 d storage at both temperatures whereas those made with modified starches were not, destabilization being faster at 35 degrees C. Beverages based on orange terpenes, in contrast to Miglyol, yielded smaller mean particle sizes, both on manufacture and during storage, regardless of hydrocolloid used. Visual observations of ringing generally supported this finding. Modified gum acacia was evaluated at both recommended and higher usage levels, stability increasing in the latter case. In general, all gum acacia and modified gum acacia emulsifiers were superior in stability to those based on modified starches, at either temperature, for orange terpene-based beverages. In Miglyol-based beverages, similar results were seen, except 1 modified starch performed as well as the gum acacia products.

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

Directory of Open Access Journals (Sweden)

Bin Li

2012-05-01

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

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

Science.gov (United States)

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

2013-02-01

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-δ-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. Copyright © 2012 Elsevier B.V. All rights reserved.

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

NARCIS (Netherlands)

Rahim, A.

2006-01-01

Keywords: Gum Arabic; Deforestation; Entry and Exit; Real options Drought; Socio-economic, Oligopoly; Interdependent markets; Stackelberg.The gum arabic belt inSudanoffered in the past an

Influence of xanthan gum on the structural characteristics of myofibrillar proteins treated by high pressure.

Science.gov (United States)

Villamonte, Gina; Jury, Vanessa; Jung, Stéphanie; de Lamballerie, Marie

2015-03-01

The effects of xanthan gum on the structural modifications of myofibrillar proteins (0.3 M NaCl, pH 6) induced by high pressure (200, 400, and 600 MPa, 6 min) were investigated. The changes in the secondary and tertiary structures of myofibrillar proteins were analyzed by circular dichroism. The protein denaturation was also evaluated by differential scanning calorimetry. Likewise, the protein surface hydrophobicity and the solubility of myofibrillar proteins were measured. High pressure (600 MPa) induced the loss of α-helix structures and an increase of β-sheet structures. However, the presence of xanthan gum hindered the former mechanism of protein denaturation by high pressure. In fact, changes in the secondary (600 MPa) and the tertiary structure fingerprint of high-pressure-treated myofibrillar proteins (400 to 600 MPa) were observed in the presence of xanthan gum. These modifications were confirmed by the thermal analysis, the thermal transitions of high-pressure (400 to 600 MPa)-treated myofibrillar proteins were modified in systems containing xanthan gum. As consequence, the high-pressure-treated myofibrillar proteins with xanthan gum showed increased solubility from 400 MPa, in contrast to high-pressure treatment (600 MPa) without xanthan gum. Moreover, the surface hydrophobicity of high-pressure-treated myofibrillar proteins was enhanced in the presence of xanthan gum. These effects could be due to the unfolding of myofibrillar proteins at high-pressure levels, which exposed sites that most likely interacted with the anionic polysaccharide. This study suggests that the role of food additives could be considered for the development of meat products produced by high-pressure processing. © 2015 Institute of Food Technologists®

Tin-containing zeolites are highly active catalysts for the isomerization of glucose in water

OpenAIRE

Moliner, Manuel; Román-Leshkov, Yuriy; Davis, Mark E.

2010-01-01

The isomerization of glucose into fructose is a large-scale reaction for the production of high-fructose corn syrup (HFCS; reaction performed by enzyme catalysts) and recently is being considered as an intermediate step in the possible route of biomass to fuels and chemicals. Here, it is shown that a large-pore zeolite that contains tin (Sn-Beta) is able to isomerize glucose to fructose in aqueous media with high activity and selectivity. Specifically, a 10% (wt/wt) glucose solution containin...

Novel calcified gum Arabic porous nano-composite scaffold for bone tissue regeneration.

Science.gov (United States)

Hadavi, M; Hasannia, S; Faghihi, Sh; Mashayekhi, F; Zadeh, H H; Mostofi, S B

2017-07-08

The aim of this study was to investigate the biomechanical and biological properties of a nanocomposite scaffold containing both mineral and polysaccharide constituents. Hydroxyapatite nanoparticles (n-HA) was synthesized from dead abra ovata shells using wet chemical methods and was used in different ratios in concert with gum Arabic, a branched plant polysaccharide. N-HA/gum nanocomposite was fabricated with freeze-drying process and characterized by FTIR and SEM for chemical structure and morphology. Porosity was estimated using liquid substitution method. The scaffold mechanical properties were evaluated by compressive test measurement. Osteogenic differentiation was assessed using alkaline phosphatase production and biomineralization was evaluated using Alizarin red assay. Results demonstrated that the hydroxyapatite/gum Arabic nanocomposite had favorable biocompatibility and a similar structure to natural bone matrix. Porous nanocomposite possessed macropore networks with a porosity 87-93% and mean pore size ranging between 164 and 230 μm. The gum/HA with a ratio of 50% w/w HA had the highest compressive modulus of ∼75.3 MPa Pa (MPa) and the ultimate compressive stress of ∼16.6 MPa. C2C12 cells cultured on a scaffold with higher percentage (40 and 50 w/w) of HA demonstrated increased ALP levels and calcium deposition. The data from the present study demonstrated significant changes to the biomechanical properties and osteoconductivity of the nanocomposite scaffold by modulating its mineral content. Nanocomposite scaffolds containing gum and n-HA of 40-50% exhibited highest mechanical properties, as well as supported increased biomineralization. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Science.gov (United States)

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

2013-02-13

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 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.

Franšīzes līgums

OpenAIRE

Bērziņš, Artūrs

2011-01-01

Bakalaura darba "Franšīzes līgums" mērķis ir jaunā nacionālā tiesiskā regulējuma izpēte, tā atbilstības starptautiskajam regulējumam konstatēšana. Bakalaura darbs sastāv no četrām nodaļām, kurās tiek aplūkots franšīzes līgums un tā būtība, tā atšķirība no citiem civiltieskiem līgumiem, franšīzes attīstība Latvijā un tiesiskā regulējuma pilnveidošana Eiropas Savienības tiesiskā regulējuma ietvaros, kā arī problēmjautājumi un to risinājums. Darba autors nonāk pie secinājuma, ka nolūkā past...

Probiotic capsules and xylitol chewing gum to manage symptoms of pharyngitis: a randomized controlled factorial trial.

Science.gov (United States)

Little, Paul; Stuart, Beth; Wingrove, Zoe; Mullee, Mark; Thomas, Tammy; Johnson, Sophie; Leydon, Gerry; Richards-Hall, Samantha; Williamson, Ian; Yao, Lily; Zhu, Shihua; Moore, Michael

2017-12-18

Reducing the use of antibiotics for upper respiratory tract infections is needed to limit the global threat of antibiotic resistance. We estimated the effectiveness of probiotics and xylitol for the management of pharyngitis. In this parallel-group factorial randomized controlled trial, participants in primary care (aged 3 years or older) with pharyngitis underwent randomization by nurses who provided sequential intervention packs. Pack contents for 3 kinds of material and advice were previously determined by computer-generated random numbers: no chewing gum, xylitol-based chewing gum (15% xylitol; 5 pieces daily) and sorbitol gum (5 pieces daily). Half of each group were also randomly assigned to receive either probiotic capsules (containing 24 × 10 9 colony-forming units of lactobacilli and bifidobacteria) or placebo. The primary outcome was mean self-reported severity of sore throat and difficulty swallowing (scale 0-6) in the first 3 days. We used multiple imputation to avoid the assumption that data were missing completely at random. A total of 1009 individuals consented, 934 completed the baseline assessment, and 689 provided complete data for the primary outcome. Probiotics were not effective in reducing the severity of symptoms: mean severity scores 2.75 with no probiotic and 2.78 with probiotic (adjusted difference -0.001, 95% confidence interval [CI] -0.24 to 0.24). Chewing gum was also ineffective: mean severity scores 2.73 without gum, 2.72 with sorbitol gum (adjusted difference 0.07, 95% CI -0.23 to 0.37) and 2.73 with xylitol gum (adjusted difference 0.01, 95% CI -0.29 to 0.30). None of the secondary outcomes differed significantly between groups, and no harms were reported. Neither probiotics nor advice to chew xylitol-based chewing gum was effective for managing pharyngitis. Trial registration: ISRCTN, no. ISRCTN51472596. © 2017 Joule Inc. or its licensors.

Preparation of Acetylated Guar Gum – Unsaturated Polyester Composites & Effect of Water on Their Properties

Directory of Open Access Journals (Sweden)

David D’Melo

2012-07-01

Full Text Available Guar gum has seen extensive use in blends, however, its application as a filler in thermoset composites has as yet not been investigated. The effect of the addition of guar gum and its acetyl derivatives on the kinetics of water diffusion in unsaturated polyester composites was studied. The effect of water on the mechanical properties of the composites was studied with respect to the nature of filler, filler concentration and time of immersion. All the mechanical properties were observed to decrease on exposure to water. Further, it was observed that acetylated guar gum, with a degree of substitution of 0.21, showed the best mechanical properties, surpassing the other filled composites and that of the pure unsaturated polyester. Thus, acetylated guar gum showed promise as eco-friendly filler in composite formulation.

Trace element evaluation of different varieties of chewing gum by radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Zaidi, J.H.; Arif, M.; Fatima, I.; Ahmad, S.; Qureshi, I.H.

2000-01-01

Extensive use of chewing gums, by children in particular, entails the evaluation of trace element contents in them. Radiochemical neutron activation analysis (RNAA) was successfully employed to determine the concentration of 35 trace elements (essential, toxic and nonessential) in eight different brands of chewing gum generally consumed in Rawalpindi/Islamabad area. Comparison of trace element data of our work with literature has been presented. None of the elements detected in the brands of chewing gum examined was found to be present at a level representing a substantial contribution to the total dietary intake of the element. (author)

Neuropharmacological screening of essential oil from oleo gum resin of Gardenia lucida Roxb.

Science.gov (United States)

Shareef, Mohammad Zubair; Yellu, Narsimha Reddy; Achanta, Venkata Narsimha Appa Rao

2013-10-07

The oleo gum resin of Gardenia lucida is commonly employed in traditional medicine to treat multiple ailments, including epilepsy and mania. The essential oil isolated from it was screened for CNS activities to check if it is responsible for the claims made regarding the traditional use of the oleo gum resin. The hypnotic and anticonvulsant activity was assessed by pentobarbitone induced hypnosis and convulsant models-Maximum electroshock (MES) and Pentylene tetrazole (PTZ) respectively. Effect on motor activity was evaluated using an actophotometer, rotarod and grip strength methods. The oil significantly potentiated the barbitone induced hypnosis and offered significant protection against the intensity and frequency of convulsions and mortality rate in both the convulsant models. A significant decrease in locomotion, motor impairment and loss of gripping reflex was also observed. The essential oil of the oleo gum resin of Gardenia lucida is a CNS depressant and anticonvulsant with central muscle relaxant properties. This justifies the claims made regarding the use of the oleo gum resin of Gardenia lucida in CNS disorders. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

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

Science.gov (United States)

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

1990-01-01

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

Rheological Characterization of Isabgol Husk, Gum Katira Hydrocolloids, and Their Blends

Directory of Open Access Journals (Sweden)

Vipin Kumar Sharma

2014-01-01

Full Text Available The rheological parameters of Isabgol husk, gum katira, and their blends were determined in different media such as distilled water, 0.1 N HCl, and phosphate buffer (pH 7.4. The blend properties of Isabgol husk and gum katira were measured for four different percentage compositions in order to understand their compatibility in dispersion form such as 00 : 100, 25 : 50, 50 : 50, 75 : 25, and 100 : 00 in the gel strength of 1 mass%. The miscibility of blends was determined by calculating Isabgol husk-gum katira interaction parameters by Krigbaum and Wall equation. Other rheological properties were analyzed by Bingham, Power, Casson, Casson chocolate, and IPC paste analysis. The study revealed that the power flow index “p” was less than “1” in all concentrations of Isabgol husk, gum katira, and their blends dispersions indicating the shear-thinning (pseudoplastic behavior. All blends followed pseudoplastic behavior at thermal conditions as 298.15, 313.15, and 333.15°K and in dispersion media such as distilled water, 0.1 N HCl, and phosphate buffer (pH 7.4. Moreover, the study indicated the applicability of these blends in the development of drug delivery systems and in industries, for example, ice-cream, paste, nutraceutical, and so forth.

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

Science.gov (United States)

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

2013-10-01

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. © 2013 John Wiley & Sons Ltd.

Flavor release measurement from gum model system

DEFF Research Database (Denmark)

Ovejero-López, I.; Haahr, Anne-Mette; van den Berg, Frans W.J.

2004-01-01

composition can be measured by both instrumental and sensory techniques, providing comparable information. The peppermint oil level (0.5-2% w/w) in the gum influenced both the retronasal concentration and the perceived peppermint flavor. The sweeteners' (sorbitol or xylitol) effect is less apparent. Sensory...

Concurrent Mass Measurement and Laser Spectroscopy for Unambiguous Isomeric State Assignment

Science.gov (United States)

Lascar, Daniel; Babcock, Carla; Henderson, Jack; Pearson, Matt

2017-09-01

Recent work by the TITAN group at TRIUMF on isomeric state mass measurements of odd-A, neutron-rich cadmium nuclei has shown a disconnect between experiment and theory in 127 g , mCd. The spin and parity assignments of the ground and isomeric states are assigned as 3/2+ and 11/2-, respectively, primarily via systematic arguments. Conversely, state of the art shell model and ab initio calculations show a reversal of the states, predicting a ground state of 11/2- and a 3/2+ isomer. Penning Trap Mass Spectrometry (PTMS) can measure the energy separation between the ground state and the isomer without ambiguity but cannot, on its own, comment on the spin and parity. Collinear Laser Spectroscopy (CLS) experiments have been performed on 127Cd and have elegantly demonstrated the existence of both 3/2+ and 11/2- states. What CLS cannot do, on its own, is assign an ordering to those states. If, however, a PTMS and CLS experiment could be performed concurrently using identical beams from the same facility then there exists sufficient information shared between both experiments that a definitive assignment can be made. We present a concept for a new slate of measurements using existing experimental facilities simultaneously, with shared resources, to definitively assign spin and parity for ground and isomeric states in short-lived nuclei.

Antinociceptive activity of Astragalus gummifer gum (gum tragacanth through the adrenergic system: A in vivo study in mice

Directory of Open Access Journals (Sweden)

Seyyed Majid Bagheri

2015-01-01

Full Text Available Background: In Iranian traditional medicine, gum obtained from Astragalus gummifer and some other species of Astragalus was used as analgesic agent. Objective: In this study, we investigated the antinociceptive effect of several concentrations (125, 250, and 500 μg/kg body weight of Astragalus gummifer gum (AGG on thermal and acetic acid induced pain in mice. Materials and Methods: AGG was dissolved in distillated water and injected i.p to male mice 15 minute before the onset of experiment. Writhing and hot-plate tests were applied to study the analgesic effect of AGG and compared with that of diclofenac sodium (30 mg/kg, i.p. or morphine (8 mg/kg, i.p. To investigate the mechanisms involved in antinociception, yohimbine, naloxone, glibenclamide, and theophylline were used in writhing test. These drugs were injected intraperitoneally 15 min before the administration of AGG. The number of writhes were counted in 30 minutes and analyzed. Results: AGG exhibited a significant antinociceptive effect and the most effective dose of AGG was 500 μg/kg. The most maximum possible effect (%MPE was observed (117.4% 15 min after drug administration. The %inhibition of acetic acid-induced writhing in AGG 125, 250 and 500 was 47%, 50% and 54% vs %15 of control and 66.3% of diclofenac sodium group. The antinociceptive effect induced by this gum in the writhing test was reversed by the systemic administration of yohimbine (α2 -adrenergic antagonist, but naloxone, glibenclamide, and theophylline did not reverse this effect. Conclusions: The findings of this study indicated that AGG induced its antinociceptive through the adrenergic system.

High-pressure liquid chromatographic determination of chlorphenesin carbamate and the beta-isomeric carbamate.

Science.gov (United States)

Beyer, W F

1976-12-01

A high-pressure liquid chromatographic assay was developed for the determination of chlorphenesin carbamate and its beta-isomeric carbamate. A single 4-mm i.d. X 30-cm column, prepacked with 10 micrometer fully porous silica gel particles, is used with 3% methanol in 50% water-saturated butyl chloride as the mobile phase. The procedure separates chlorphenesin carbamate from several possible impurities in addition to the beta-isomeric carbamate. The assay was applied to bulk drug and compressed tablets. The relative standard deviations for the assays of chlorphenesin carbamate and the beta-isomer are approximately 1 and 2%, respectively.

Isomeric ratio measurements for the radiative neutron capture 176Lu(n,γ at DANCE

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Denis-Petit D.

2017-01-01

Full Text Available The isomeric ratios for the neutron capture reaction 176Lu(n,γ to the Jπ = 5/2−, 761.7 keV, T1/2 = 32.8 ns and the Jπ = 15/2+, 1356.9 keV, T1/2 = 11.1 ns levels of 177Lu, have been measured for the first time with the Detector for Advanced Neutron Capture Experiments (DANCE at the Los Alamos National Laboratory. These measured isomeric ratios are compared with TALYS calculations.

Short-term effect of chewing gums containing probiotic Lactobacillus reuteri on the levels of inflammatory mediators in gingival crevicular fluid

DEFF Research Database (Denmark)

Twetman, Svante; Derawi, Bilal; Keller, Mette

2009-01-01

OBJECTIVE: To investigate the effect of a chewing gum containing probiotic bacteria on gingival inflammation and the levels of selected inflammatory mediators in gingival crevicular fluid (GCF). MATERIAL AND METHODS: Forty-two healthy adults with moderate levels of gingival inflammation entered...... a double-blind placebo-controlled study design. The subjects were randomly assigned to one of three parallel arms: Group A/P was given one active and one placebo gum daily, Group A/A received two active chewing gums, and Group P/P two placebo gums. The chewing gums contained two strains of Lactobacillus...... reuteri: ATCC 55730 and ATCC PTA 5289 (1 x 10(8) CFU/gum, respectively). The subjects were instructed to chew the gums for 10 min over the course of 2 weeks. Bleeding on probing (BOP) and GCF sampling were conducted at baseline and after 1, 2 and 4 weeks. The levels of IL-1beta, TNF-alpha, IL-6, IL-8...

Enhancement of electrical conductivity in the Gum Arabica complex

International Nuclear Information System (INIS)

Pradhan, Sourav S.; Sarkar, A.

2009-01-01

Gum Arabica is a natural biopolymer obtained from plant Acacia Arabica. In this present study the electro-active nature of its complex has been investigated. The complexes were developed using pure Gum Arabica and pure Citric acid by the sol-gel process. The scope of complex formation has been investigated and their natures were examined experimentally. The experiments which were carried out in this work are namely d.c V-I characteristics, d.c Arrhenius, ion transference number measurement, UV-VIS and IR photo-absorption. Solid specimen of the complex at various concentration of Citric acid has been developed for d.c experiments and adequate specimens were also developed for UV-VIS experiment. The result of d.c V-I characteristics on specimens at different Citric acid concentrations shows that d.c conductivity increases with concentration of the acid. The said enhancement is observed to be about 100 times that of pure hosts. The ion transference number measurement shows that the total conductivity increases with external acid concentration of which d.c conductivity enhance many times compared to that of ionic part. The result from d.c Arrhenius study shows that electro-thermal activation energy decreases with increasing acid concentration leading to enhancement of electronic conductivity of the complex. The result of UV-VIS study confirms the formation of the acid complex of Gum Arabica. The nature of photo-absorption indicates very clearly that main absorption region shows gradual shifts towards longer wavelength with increase of acid concentration. The result of FTIR absorption shows the structural concepts of electro-activity and complex formation indication of pure Gum Arabica. The overall analysis shows that the electro-activity of the mentioned biopolymer may be tailored.

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

Science.gov (United States)

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

2012-01-01

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

Examples of measurement uncertainty evaluations in accordance with the revised GUM

Science.gov (United States)

Runje, B.; Horvatic, A.; Alar, V.; Medic, S.; Bosnjakovic, A.

2016-11-01

The paper presents examples of the evaluation of uncertainty components in accordance with the current and revised Guide to the expression of uncertainty in measurement (GUM). In accordance with the proposed revision of the GUM a Bayesian approach was conducted for both type A and type B evaluations.The law of propagation of uncertainty (LPU) and the law of propagation of distribution applied through the Monte Carlo method, (MCM) were used to evaluate associated standard uncertainties, expanded uncertainties and coverage intervals. Furthermore, the influence of the non-Gaussian dominant input quantity and asymmetric distribution of the output quantity y on the evaluation of measurement uncertainty was analyzed. In the case when the probabilistically coverage interval is not symmetric, the coverage interval for the probability P is estimated from the experimental probability density function using the Monte Carlo method. Key highlights of the proposed revision of the GUM were analyzed through a set of examples.

Second-chance forward isomerization dynamics of the red/green cyanobacteriochrome NpR6012g4 from Nostoc punctiforme.

Science.gov (United States)

Kim, Peter W; Freer, Lucy H; Rockwell, Nathan C; Martin, Shelley S; Lagarias, J Clark; Larsen, Delmar S

2012-01-11

The primary ultrafast Z-to-E isomerization photodynamics of the phytochrome-related cyanobacteriochrome NpR6012g4 from Nostoc punctiforme was studied by transient absorption pump-dump-probe spectroscopy. A 2 ps dump pulse resonant with the stimulated emission band depleted 21% of the excited-state population, while the initial photoproduct Lumi-R was depleted by only 11%. We observed a red-shifted ground-state intermediate (GSI) that we assign to a metastable state that failed to isomerize fully. Multicomponent global analysis implicates the generation of additional Lumi-R from the GSI via crossing over the ground-state thermal barrier for full isomerization, explaining the discrepancy between excited-state and Lumi-R depletion by the dump pulse. This second-chance ground-state dynamics provides a plausible explanation for the unusually high quantum yield of 40% for the primary isomerization step in the forward reaction of NpR6012g4. © 2011 American Chemical Society

Development and Antibacterial Activity of Cashew Gum-Based Silver Nanoparticles

Directory of Open Access Journals (Sweden)

Maria José dos S. Soares

2013-03-01

Full Text Available 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.

Measurement of millisecond half-lives of isomeric levels in some nuclei

Energy Technology Data Exchange (ETDEWEB)

Garg, K C; Khurana, C S [Punjabi Univ., Patiala (India). Nuclear Science Labs.

1976-09-01

Half-lives of 2.7, 14.5, 17, 20, 20.4, 44 and 2230 msec, of isomeric levels in /sup 208/Bi, /sup 88/Y, /sup 75/As, /sup 24/Na, /sup 71/Ge, /sup 114/In and /sup 167/Er respectively have been measured, employing on-line irradiation system. These millisecond isomeric levels are produced by 14.7 MeV neutrons through (n,p), (n,..cap alpha..), (n,n') and (n,2n) reactions on natural target samples. A ..gamma..-ray scintillation detector coupled with NTA-512B, 1024 channel analyzer has been used to follow the decay of the millisecond activities. Deflected deuteron beam bursts have been used to reduce the long-time background to initial count ratios in the decay curves to achieve a better accuracy of measurements.

Unveiling the Sources of Chromium in Pictorialist Photographs: Gum-Dichromate Process or Paper Sizing?

DEFF Research Database (Denmark)

Vila, Anna; Centeno, Silvia A; Kennedy, Nora W

2015-01-01

For this issue of Hand Papermaking devoted to paper sizing, we offer a review and extension of pertinent results obtained in our investigations of the gum-dichromate photographic process, commonly known as the gum-bichromate process.1 We have published three articles to date on our findings; this...

NaSO2Ph Induced Exclusive Isomerization of 1,2-Allenyl Sulfoxides to 2-Alkynylic Phenyl Sulfoxides

Institute of Scientific and Technical Information of China (English)

傅春玲; 麻生明

2005-01-01

The clean isomerization of 1,2-allenyl sulfoxides in the presence of NaSO2Ph afforded 2-alkynylic phenyl sulfoxides in good yields and selectivities. Although strong base-catalyzed isomerization of allenes to alkynes is known, the mechanism for the current reaction is interesting for the obvious reason that NaSOEPh is a weak base.

The hypolipidaemic effect of gum tragacanth in diet induced hyperlipidaemia in rats.

Science.gov (United States)

Amer, S; Kamil, R; Siddiqui, P Q

1999-07-01

Previous research indicated that fiber in the diet of men lowers plasma lipid and LDL cholesterol concentration. To further study the lipid lowering effect of fibre, we conducted an animal study using rats with diet induced hyperlipidaemia. Rats were randomly assigned to one of the three experimental diets. Two of the diets contained cholesterol and choice acid to induce hyperlipidaemia, the fiber source in the hyperlipidaemic diet was gum tragacanth (5%). The rats consumed one of the three diets ad libitum for 4 weeks before they were killed. Plasma LDL cholesterol and total cholesterol concentrations were significantly higher in the hyperlipidaemic group than in the non hyperlipidaemic control group. A marked improvement in the plasma LDL cholesterol and total cholesterol concentration was observed in the rats that were fed hyperlipidaemic diet containing grum tragacanth. No significant difference in the plasma triglyceride concentration was detected in the three groups. Plasma HDL concentration was significantly higher in the non-hyperlipidaemic group than in the hyperlipidaemic group than. Addition of gum tragacanth to the hyperlipidaemic diet significantly improved the plasma HDL concentration in the hyperlipidaemic rats. These results suggest that fiber from gum tragacanth lowers plasma cholesterol and LDL in hyperlipidaemia. Gum tragacanth could be useful adjunct to the dietary management of hyperlipidaemia.

An infrared study of the nitro—nitrito linkage isomerization in solid nitro- and nitritopentamminecobalt(III) chloride

Science.gov (United States)

Heyns, A. M.; de Waal, D.

1989-01-01

The photochemical isomerization reaction of [Co(NH 3) 5NO 2]Cl 2 to [Co(NH 3) 5ONO]Cl 2 has been studied in the solid state by means of i.r. spectroscopy. The reaction is first order with k = 2.53±0.05 × 10 -4s -1 and is much faster ( t1/2=49min) than the well-known spontaneous nitrito → nitro isomerization ( t1/2 = 6 days). The i.r. bands of both the NH 3 and ONO - -groups in the range 4000-50 cm -1 indicate minor differences between the structures of freshly and photochemically prepared [Co(NH 3) 5ONO]Cl 2. The far i.r. spectra indicate the disorder existing in the intermediate products during the isomerization processes.

Isomerization of 2-phospha-4-silabicyclo[1.10]butane

NARCIS (Netherlands)

Slootweg, J.C.; Ehlers, A.W.; Lammertsma, K.

2004-01-01

In analogy with the valence isomerism of the hydrocarbons bicyclobutane, 1,3-butadiene and cyclobutene, the rearrangements for 2-phospha-4-sila- bicyclo[1.1.0]butane were studied at the B3LYP/6-311+G** level of theory. The monocyclic 1,2-dihydro-1,2-phosphasilete is shown to be the thermodynamically

Spontaneous Isomerization of Peptide Cation Radicals Following Electron Transfer Dissociation Revealed by UV-Vis Photodissociation Action Spectroscopy.

Science.gov (United States)

Imaoka, Naruaki; Houferak, Camille; Murphy, Megan P; Nguyen, Huong T H; Dang, Andy; Tureček, František

2018-01-16

Peptide cation radicals of the z-type were produced by electron transfer dissociation (ETD) of peptide dications and studied by UV-Vis photodissociation (UVPD) action spectroscopy. Cation radicals containing the Asp (D), Asn (N), Glu (E), and Gln (Q) residues were found to spontaneously isomerize by hydrogen atom migrations upon ETD. Canonical N-terminal [z 4 + H] +● fragment ion-radicals of the R-C ● H-CONH- type, initially formed by N-C α bond cleavage, were found to be minor components of the stable ion fraction. Vibronically broadened UV-Vis absorption spectra were calculated by time-dependent density functional theory for several [ ● DAAR + H] + isomers and used to assign structures to the action spectra. The potential energy surface of [ ● DAAR + H] + isomers was mapped by ab initio and density functional theory calculations that revealed multiple isomerization pathways by hydrogen atom migrations. The transition-state energies for the isomerizations were found to be lower than the dissociation thresholds, accounting for the isomerization in non-dissociating ions. The facile isomerization in [ ● XAAR + H] + ions (X = D, N, E, and Q) was attributed to low-energy intermediates having the radical defect in the side chain that can promote hydrogen migration along backbone C α positions. A similar side-chain mediated mechanism is suggested for the facile intermolecular hydrogen migration between the c- and [z + H] ● -ETD fragments containing Asp, Asn, Glu, and Gln residues. Graphical Abstract ᅟ.

Spontaneous Isomerization of Peptide Cation Radicals Following Electron Transfer Dissociation Revealed by UV-Vis Photodissociation Action Spectroscopy

Science.gov (United States)

Imaoka, Naruaki; Houferak, Camille; Murphy, Megan P.; Nguyen, Huong T. H.; Dang, Andy; Tureček, František

2018-01-01

Peptide cation radicals of the z-type were produced by electron transfer dissociation (ETD) of peptide dications and studied by UV-Vis photodissociation (UVPD) action spectroscopy. Cation radicals containing the Asp (D), Asn (N), Glu (E), and Gln (Q) residues were found to spontaneously isomerize by hydrogen atom migrations upon ETD. Canonical N-terminal [z4 + H]+● fragment ion-radicals of the R-C●H-CONH- type, initially formed by N-Cα bond cleavage, were found to be minor components of the stable ion fraction. Vibronically broadened UV-Vis absorption spectra were calculated by time-dependent density functional theory for several [●DAAR + H]+ isomers and used to assign structures to the action spectra. The potential energy surface of [●DAAR + H]+ isomers was mapped by ab initio and density functional theory calculations that revealed multiple isomerization pathways by hydrogen atom migrations. The transition-state energies for the isomerizations were found to be lower than the dissociation thresholds, accounting for the isomerization in non-dissociating ions. The facile isomerization in [●XAAR + H]+ ions (X = D, N, E, and Q) was attributed to low-energy intermediates having the radical defect in the side chain that can promote hydrogen migration along backbone Cα positions. A similar side-chain mediated mechanism is suggested for the facile intermolecular hydrogen migration between the c- and [z + H]●-ETD fragments containing Asp, Asn, Glu, and Gln residues. [Figure not available: see fulltext.

Development of Oral Dissolvable Films of Diclofenac Sodium for Osteoarthritis Using Albizia and Khaya Gums as Hydrophilic Film Formers

Directory of Open Access Journals (Sweden)

Martina Aduenimaa Bonsu

2016-01-01

Full Text Available Oral dissolvable films (ODFs of diclofenac sodium intended for osteoarthritis were prepared using Albizia and Khaya gums as hydrophilic film formers. The physicochemical properties of the gums were characterized and the gums were used to prepare diclofenac sodium ODFs (~50 mg/4 cm2 film by solvent casting. The two gums showed satisfactory film forming properties. The physicomechanical properties, drug-excipient compatibility, and in vitro drug release of the films in phosphate buffer pH 6.8 were studied. Khaya gum had higher extraction yield, moisture content, insoluble matter and true density while Albizia gum showed greater swelling capacity, solubility, and minerals content. The ODFs were thin, soft, and flexible with smooth glossy surfaces and possessed satisfactory physicomechanical properties. FTIR studies showed that no interaction occurred between the drug and the gums. The ODFs disintegrated in 75% drug release within 7 min with dissolution efficiencies of ~83–96%. Drug releases from F2, F3, F4, F5, and F6 were similar to F1 (p>0.05; f115 and f2<50. Drug release followed the Higuchi kinetic model which is indicative of Fickian drug diffusion.

Kinetic study of the gum decomposition from brazilian gasoline; Estudo cinetico da decomposicao da goma oriunda de gasolina brasileira

Energy Technology Data Exchange (ETDEWEB)

Pivesso, Paulo Roberto; Galvao, Luzia Patricia Fernandes de Carvalho; Fernandes Junior, Valter Jose; Coutinho, Ana Carla S.L.S. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Souza, Antonio Gouveia de [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil)

2004-07-01

The modern gasoline contains in your composition insatured hydrocarbons that can be degraded by the action of the air, heat and substances presenting catalytic activity. The presence of air and heat promote oxidation reactions and polymerization, which promote the gum formation, that is a product with diverse characteristics. The petroleum and l the automobile industries have been investing in researches to lessen the gum undesirable effects. Nowadays, several products are added to the gasoline, for example, the surfactant additives, with the purpose to reduce the formation of deposits in the engine. This work evaluated the influence of a polyester amine addictive, used as the main active component in Brazilian gasoline. The gums were generated evaporating the gasolines according to the ASTM D 381 method. Two types of gum were obtained; the Common Washed Gum (White Sample) and the Additive based Washed Gum (Additive Sample). Both samples were characterized for thermal analysis and submitted for a kinetic study using the model-free method proposed by Vyazovkin. This approach was applied to the final stage of the gums decomposition, supplying the corresponding relative kinetic parameters, such as energy of activation and conversion (author)

Effects of caffeinated chewing gum on muscle pain during submaximal isometric exercise in individuals with fibromyalgia.

Science.gov (United States)

Umeda, Masataka; Kempka, Laura; Weatherby, Amy; Greenlee, Brennan; Mansion, Kimberly

2016-04-01

Physical activity is important to manage symptom of fibromyalgia (FM); however, individuals with FM typically experience augmented muscle pain during exercise. This study examined the effects of caffeinated chewing gum on exercise-induced muscle pain in individuals with FM. This study was conducted with a double-blind, placebo-controlled, cross-over design. Twenty-three patients with FM completed a caffeine condition where they consumed a caffeinated chewing gum that contains 100mg of caffeine, and a placebo condition where they consumed a non-caffeinated chewing gum. They completed isometric handgrip exercise at 25% of their maximal strength for 3 min, and muscle pain rating (MPR) was recorded every 30s during exercise. Clinical pain severity was assessed in each condition using a pain questionnaire. The order of the two conditions was randomly determined. MPR increased during exercise, but caffeinated chewing gum did not attenuate the increase in MPR compared to placebo gum. Clinical pain severity was generally associated with the average MPR and the caffeine effects on MPR, calculated as difference in the average MPR between the two conditions. The results suggest that more symptomatic individuals with FM may experience greater exercise-induced muscle pain, but benefit more from caffeinated chewing gum to reduce exercise-induced muscle pain. Copyright © 2016 Elsevier Inc. All rights reserved.

Efficient assembly of polysubstituted pyrroles via a (3 + 2) cycloaddition/skeletal rearrangement/redox isomerization cascade reaction.

Science.gov (United States)

Yu, Yuanyuan; Wang, Chunyu; He, Xinze; Yao, Xiaotong; Zu, Liansuo

2014-07-03

An unprecedented cascade strategy, used in conjunction with a redox isomerization, for the synthesis of 3-allyl pyrroles is reported. In a single step, readily accessible simple starting materials are transformed into highly substituted pyrroles with high efficiency. The products obtained contain allyl substituents, which can be readily elaborated to other useful functional groups. The reaction proceeds through an unusual (3 + 2) cycloaddition/skeletal rearrangement/redox isomerization pathway.

Analysis of temporal variation in human masticatory cycles during gum chewing.

Science.gov (United States)

Crane, Elizabeth A; Rothman, Edward D; Childers, David; Gerstner, Geoffrey E

2013-10-01

The study investigated modulation of fast and slow opening (FO, SO) and closing (FC, SC) chewing cycle phases using gum-chewing sequences in humans. Twenty-two healthy adult subjects participated by chewing gum for at least 20s on the right side and at least 20s on the left side while jaw movements were tracked with a 3D motion analysis system. Jaw movement data were digitized, and chewing cycle phases were identified and analysed for all chewing cycles in a complete sequence. All four chewing cycle phase durations were more variant than total cycle durations, a result found in other non-human primates. Significant negative correlations existed between the opening phases, SO and FO, and between the closing phases, SC and FC; however, there was less consistency in terms of which phases were negatively correlated both between subjects, and between chewing sides within subjects, compared with results reported in other species. The coordination of intra-cycle phases appears to be flexible and to follow complex rules during gum-chewing in humans. Alternatively, the observed intra-cycle phase relationships could simply reflect: (1) variation in jaw kinematics due to variation in how gum was handled by the tongue on a chew-by-chew basis in our experimental design or (2) by variation due to data sampling noise and/or how phases were defined and identified. Copyright © 2013 Elsevier Ltd. All rights reserved.

Determination of the isomeric fraction in a postaccelerated radioactive ion beam using the coupled decay-chain equations

CERN Document Server

Ekstrom, A; Dijulio, D D; Cederkall, J; Van de Walle, J

2010-01-01

A method based on the coupled decay-chain equations for extracting the isotopic and the isomeric composition of a postaccelerated radioactive ion beam is presented and demonstrated on a data set from a Coulomb excitation experiment. This is the first attempt of analyzing the content of a postaccelerated radioactive ion beam using this technique. The beam composition is required for an absolute normalization of the measurement. The strength of the method, as compared to present online-based methods, lies in the determination of the isomeric fraction of a partially isomeric beam using all data accumulated during the experiment. We discuss the limitations and sensitivity of the method with respect to the gamma-ray detection efficiency and the accumulated flux. (C) 2010 Elsevier B.V. All rights reserved.

Production and Rheological Properties of Welan Gum Produced by Sphingomonas sp. ATCC 31555 with Different Nitrogen Sources.

Science.gov (United States)

Xu, Xiaopeng; Nie, Zuoming; Zheng, Zhiyong; Zhu, Li; Zhan, Xiaobei

2017-01-01

This study aimed to investigate the effect of nitrogen sources on the production and rheological properties of welan gum produced by Sphingomonas sp. ATCC 31555. Six different nitrogen sources were used for ATCC 31555 fermentation, and 2 of these were further analyzed due to their more positive influence on welan gum production and bacterial biomass. Bacterial biomass, welan gum yield, welan viscosity, molecular weight, monosaccharide composition, acyl content, and welan structure were analyzed. Welan gum production and the biomass concentration of ATCC 31555 were higher in media containing NaNO3 and beef extract. Welan viscosity decreased at higher temperatures of 30-90°C, and it increased with a higher welan concentration. In the media containing NaNO3 (3 g·L-1), welan viscosity was higher at 30-70°C and a welan solution concentration of 6-10 g·L-1. With a reduced NaNO3 concentration, the molecular weight of welan gum and the molar ratio of mannose decreased, but the molar ratio of glucuronic acid increased. With different nitrogen sources, the acetyl content of welan gum differed but its structure was similar. NaNO3 and beef extract facilitated welan production. A reduced NaNO3 concentration promoted welan viscosity. © 2017 S. Karger AG, Basel.

Direct Measurement of the Isomerization Barrier of the Isolated Retinal Chromophore

DEFF Research Database (Denmark)

Dilger, Jonathan; Musbat, Lihi; Sheves, Mordechai

2015-01-01

Isomerizations of the retinal chromophore were investigated using the IMS-IMS technique. Four different structural features of the chromophore were observed, isolated, excited collisionally, and the resulting isomer and fragment distributions were measured. By establishing the threshold activatio...

Observation of excited states and isomeric decays in doubly-odd 208Fr

International Nuclear Information System (INIS)

Kanjilal, D.; Bhattacharya, S.; Goswami, A.; Kshetri, R.; Raut, R.; Saha, S.; Bhowmik, R.K.; Gehlot, J.; Jnaneswari, G.; Muralithar, S.; Singh, R.P.; Mukherjee, B.; Mukherjee, G.

2009-01-01

The nuclei near the doubly magic 208 Pb are predicted to exhibit various interesting structural phenomena, one of which is a wealth of isomerism. However, a detailed study of high spin states of 211, 212, 213 Fr has already been done. Structure of such trans-Lead nuclei can be interpreted in terms of the shell model states, and the high spin states of these nuclei are interpreted. One of the major interests in the spectroscopic investigation of these nuclei is the role played by the i 13/2 state in creating isomeric levels which decay through transitions of higher muiltipolarity, or are hindered by the close proximity of the levels below. A systematic study of these nuclei will possibly reveal many other interesting structural features

A NEW SPECIES OF INVASIVE GALL WASP (HYMENOPTERA: EULOPHIDAE: TETRASTICHINAE) ON BLUE GUM (EUCALYPTUS GLOBULUS) IN CALIFORNIA

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The blue gum gall wasp, Selitrichodes globulus La Salle & Gates (Hymenoptera: Eulophidae: Tetrastichinae), is described as an invasive gall inducer on blue gum, Eucalyptus globulus (Myrtaceae), in California....

EFFECT OF GUM CHEWING ON AIR SWALLOWING, SALIVA SWALLOWING AND BELCHING

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Ana Cristina Viana da SILVA

2015-09-01

Full Text Available BackgroundEructation is a physiologic event which allows gastric venting of swallowed air and most of the time is not perceived as a symptom. This is called gastric belching. Supragastric belching occurs when swallowed air does not reach the stomach and returns by mouth a short time after swallowing. This situation may cause discomfort, life limitations and problems in daily life.ObjectiveOur objective in this investigation was to evaluate if gum chewing increases the frequency of gastric and/or supragastric belches.MethodsEsophageal transit of liquid and gas was evaluated by impedance measurement in 16 patients with complaint of troublesome belching and in 15 controls. The Rome III criteria were used in the diagnosis of troublesome belching. The esophageal transit of liquid and gas was measured at 5 cm, 10 cm, 15 cm and 20 cm from the lower esophageal sphincter. The subjects were evaluated for 1 hour which was divided into three 20-minute periods: (1 while sitting for a 20-minute base period; (2 after the ingestion of yogurt (200 mL, 190 kcal, in which the subjects were evaluated while chewing or not chewing gum; (3 final 20-minute period in which the subjects then inverted the task of chewing or not chewing gum. In gastric belch, the air flowed from the stomach through the esophagus in oral direction and in supragastric belch the air entered the esophagus rapidly from proximal and was expulsed almost immediately in oral direction. Air swallows were characterized by an increase of at least 50% of basal impedance and saliva swallow by a decrease of at least 50% of basal impedance, that progress from proximal to distal esophagus.ResultsIn base period, air swallowing was more frequent in patients than in controls and saliva swallowing was more frequent in controls than in patients. There was no difference between the medians of controls and patients in the number of gastric belches and supragastric belches. In six patients, supragastric belches

Micronised bran-enriched fresh egg tagliatelle: Significance of gums addition on pasta technological features.

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Martín-Esparza, M E; Raga, A; González-Martínez, C; Albors, A

2018-06-01

The aim of the work was to produce fibre-enriched fresh pasta based on micronised wheat bran and durum wheat semolina with appropriate techno-functional properties. Wheat semolina was replaced with fine particle size (50% below 75 µm) wheat bran - up to 11.54% (w/w). A Box-Behnken design with randomised response surface methodology was used to determine a suitable combination of carboxymethylcellulose, xanthan gum and locust bean gum to improve pasta attributes: minimum cooking loss, maximum values for water gain and swelling index, as well as better colour and texture characteristics before and after cooking. The proximate chemical composition of wheat semolina and bran was determined and the microstructure of uncooked pasta was observed as well. From the response surface methodology analysis, it is recommended to use: (i) xanthan gum over 0.6% w/w as it led to bran-enriched pasta with a better developed structure and superior cooking behaviour, (ii) a combination of xanthan gum (0.8% w/w) and carboxymethylcellulose (over 0.6% w/w) to enhance uncooked pasta yellowness.

Effects of chewing gum on driving performance as evaluated by the STISIM driving simulator.

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Yoo, Ingyu; Kim, Eun-Joo; Lee, Joo-Hyun

2015-06-01

[Purpose] The purpose of this study was to determine the effects of chewing gum on driving performance in a driving simulator. [Subjects] In total, 26 young licensed drivers participated. [Methods] The driving scenario was typical of an urban environment: a single-carriageway, two-way road consisting of a mix of curved and straight sections, with considerable levels of traffic, pedestrians, and parked cars. Mean distance driven above the speed limit, lane position, mean distance driven across the center line, and mean distance driven off the road were used as estimates of brake, accelerator, and steering control. The results were compared with those of a non-chewing gum control condition. [Results] The driving performance while chewing gum was significantly better: the mean distance driven above the speed limit was 26.61% shorter, and the mean distance driven off the road was 31.99% shorter. Lane position and mean distance driven across the center line did not differ significantly between the two conditions. [Conclusion] Chewing gum appears to enhance driving performance during a sustained attention driving task.

Short-term effects of chewing gum on satiety and afternoon snack intake in healthy weight and obese women.

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Park, Eunyoung; Edirisinghe, Indika; Inui, Taichi; Kergoat, Sophie; Kelley, Michael; Burton-Freeman, Britt

2016-05-15

Afternoon snacking contributes significantly to total energy intake. Strategies to enhance the satiety value of lunch and reduce afternoon snacking are of interest for body weight management. To assess whether between-meal gum chewing would enhance the satiety response to a fixed lunch meal; and assess the role of cholecystokinin (CCK) as a potential mediator of the response in non-obese healthy weight and obese women. Fifty unrestrained obese (n=25) and non-obese healthy weight (n=25) women participated in a two-arm cross-over study assessing multiple (15min per hour×3h) gum chewing (GUM) occurrences or no gum (Control) on subjective ratings of satiety, subsequent sweet and salty snack intake, CCK and general metabolic responses. GUM compared to Control resulted in significant suppression of hunger, desire to eat and prospective consumption (pwomen (p=0.05) and Oreo cookie intake in healthy weight women (p=0.03) 3h after lunch. Metabolic responses and CCK did not differ between experimental conditions. Chewing gum intermittently post-lunch enhances perceptions of satiety and may have important implications in reducing afternoon high carbohydrate-snack intake. Copyright © 2016. Published by Elsevier Inc.

Effect of guar gum conjugation on functional, antioxidant and antimicrobial activity of egg white lysozyme.

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Hamdani, Afshan Mumtaz; Wani, Idrees Ahmed; Bhat, Naseer Ahmad; Siddiqi, Raushid Ahmad

2018-02-01

This study was undertaken to analyze the effect of conjugation of egg-white lysozyme with guar gum. Lysozyme is an antimicrobial polypeptide that can be used for food preservation. Its antibacterial activity is limited to gram positive bacteria. Conjugation with polysaccharides like guar gum may broaden its activity against gram negatives. Conjugate was developed through Maillard reaction. Assays carried out included sugar estimation, SDS-PAGE, GPC, color, FT-IR, DSC, thermal stability, solubility, emulsifying, foaming and antioxidant activity. In addition, antimicrobial activity of the conjugate was determined against two gram positive (Staphyllococcus aureus and Enterococcus) and two gram negative pathogens (E. coli and Salmonella). Results showed higher functional properties of lysozyme-guar gum conjugate. The antioxidant properties increased from 2.02-35.80% (Inhibition of DPPH) and 1.65-4.93AAE/g (reducing power) upon guar gum conjugation. Conjugate significantly inhibited gram negative bacteria and the antibacterial activity also increased significantly against gram positive pathogens. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pharmacodynamic and pharmacokinetic assessment of electronic cigarettes, combustible cigarettes, and nicotine gum: implications for abuse liability.

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Stiles, Mitchell F; Campbell, Leanne R; Graff, Donald W; Jones, Bobbette A; Fant, Reginald V; Henningfield, Jack E

2017-09-01

Electronic cigarettes (ECs) are becoming popular alternatives for smokers, but there has been limited study of their abuse liability. The objective of this study was to evaluate the abuse liability of three Vuse Solo ECs, ranging from 14 to 36 mg in nicotine content, relative to high- and low-abuse liability comparator products (usual brand combustible cigarettes and nicotine gum, respectively) in a group of 45 EC-naïve smokers. Enrolled subjects' ratings of subjective effects and nicotine uptake over 6 h were used to measure abuse liability and pharmacokinetics following in-clinic use of each EC. Use of Vuse Solo resulted in subjective measures and nicotine uptake that were between those of combustible cigarettes and nicotine gum, although generally closer to nicotine gum. Compared to combustible cigarettes, use of Vuse Solo resulted in significantly lower scores in measures of product liking, positive effects, and intent to use again. These pharmacodynamic findings were consistent with the pharmacokinetic data, showing that cigarettes produced substantially faster and higher levels of nicotine uptake as compared to Vuse Solo and nicotine gum. Vuse Solo resulted in more rapid initial uptake of nicotine compared to nicotine gum, but peak concentration and long-term extent of uptake were not different or were lower with Vuse. Collectively, these findings suggest that Vuse Solo likely has an abuse liability that is somewhat greater than nicotine gum but lower than cigarettes. ClinicalTrials.gov identifier: NCT02269514.

Isomeric cross-section ratios of some (n,2n) reactions at 14. 7 MeV

Energy Technology Data Exchange (ETDEWEB)

Garg, K C; Khurana, C S [Punjabi Univ., Patiala (India). Nuclear Science Labs.

1979-08-01

Isomeric cross-section ratios of (n,2n) reactions at 14.7 MeV leading to the millisecond isomeric levels have been calculated theoretically using the statistical theory of nuclear reactions and the spin distribution form due to Bethe and Bloch. The theoretical ratios have been compared with the experimentally measured values in order to evaluate the spin cut-off parameter sigma. This parameter has been used to calculate the effective moment of inertia of the nucleus to draw useful conclusions from the results of present calculations.

Evaluation of the content of TiO2 nanoparticles in the coatings of chewing gums.

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Dudefoi, William; Terrisse, Hélène; Popa, Aurelian Florin; Gautron, Eric; Humbert, Bernard; Ropers, Marie-Hélène

2018-02-01

Titanium dioxide is a metal oxide used as a white pigment in many food categories, including confectionery. Due to differences in the mass fraction of nanoparticles contained in TiO 2 , the estimated intakes of TiO 2 nanoparticles differ by a factor of 10 in the literature. To resolve this problem, a better estimation of the mass of nanoparticles present in food products is needed. In this study, we focused our efforts on chewing gum, which is one of the food products contributing most to the intake of TiO 2 . The coatings of four kinds of chewing gum, where the presence of TiO 2 was confirmed by Raman spectroscopy, were extracted in aqueous phases. The extracts were analysed by transmission electron microscopy (TEM), X-ray diffraction, Fourier Transform Raman spectroscopy, and inductively coupled plasma atomic emission spectroscopy (ICP-AES) to establish their chemical composition, crystallinity and size distribution. The coatings of the four chewing gums differ chemically from each other, and more specifically the amount of TiO 2 varies from one coating to another. TiO 2 particles constitute the entire coating of some chewing gums, whereas for others, TiO 2 particles are embedded in an organic matrix and/or mixed with minerals like calcium carbonate, talc, or magnesium silicate. We found 1.1 ± 0.3 to 17.3 ± 0.9 mg TiO 2 particles per piece of chewing gum, with a mean diameter of 135 ± 42 nm. TiO 2 nanoparticles account for 19 ± 4% of all particles, which represents a mass fraction of 4.2 ± 0.1% on average. The intake of nanoparticles is thus highly dependent on the kind of chewing gum, with an estimated range extending from 0.04 ± 0.01 to 0.81 ± 0.04 mg of nano-TiO 2 per piece of chewing gum. These data should serve to refine the exposure scenario.

Socioeconomic aspects of agroforesty systems: the case of gum-cultivation cycle

International Nuclear Information System (INIS)

Sharawi, H. A.

2010-01-01

The purpose of the study was to attempt to understand the nature of the problems related to production and local marketing of gum arabic as been by producers and local traders. Using structural questionnaires and multistage stratified sampling, data were collected on economic activities, production and productivity, price and pricing policy and marketing and trade as well as services provided to producers. Statistical analysis was carried out using various descriptive methods including means and means comparisons. The results indicated a general declining trend of the areas trapped by households. Productivity per unit area, prices received by producers and different from of services during the period covered by the study. The level of the producer's price seems to be the most important socioeconomic factor affecting the decision to produce. The need for institutions that are more effective and of services that promote production and marketing were seen as essential. The results have important implications on pricing policies and sustain ability of the gum-cultivation cycle as an integrated management system in the gum belt of the Sudan.(Author)

Compartmental and noncompartmental modeling of ¹³C-lycopene absorption, isomerization, and distribution kinetics in healthy adults.

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Moran, Nancy E; Cichon, Morgan J; Riedl, Kenneth M; Grainger, Elizabeth M; Schwartz, Steven J; Novotny, Janet A; Erdman, John W; Clinton, Steven K

2015-12-01

Lycopene, which is a red carotenoid in tomatoes, has been hypothesized to mediate disease-preventive effects associated with tomato consumption. Lycopene is consumed primarily as the all-trans geometric isomer in foods, whereas human plasma and tissues show greater proportions of cis isomers. With the use of compartmental modeling and stable isotope technology, we determined whether endogenous all-trans-to-cis-lycopene isomerization or isomeric-bioavailability differences underlie the greater proportion of lycopene cis isomers in human tissues than in tomato foods. Healthy men (n = 4) and women (n = 4) consumed (13)C-lycopene (10.2 mg; 82% all-trans and 18% cis), and plasma was collected over 28 d. Unlabeled and (13)C-labeled total lycopene and lycopene-isomer plasma concentrations, which were measured with the use of high-performance liquid chromatography-mass spectrometry, were fit to a 7-compartment model. Subjects absorbed a mean ± SEM of 23% ± 6% of the lycopene. The proportion of plasma cis-(13)C-lycopene isomers increased over time, and all-trans had a shorter half-life than that of cis isomers (5.3 ± 0.3 and 8.8 ± 0.6 d, respectively; P lycopene bioavailability and endogenous trans-to-cis-lycopene isomerization was predictive of plasma (13)C and unlabeled cis- and all-trans-lycopene concentrations. Although the bioavailability of cis (24.5% ± 6%) and all-trans (23.2% ± 8%) isomers did not differ, endogenous isomerization (0.97 ± 0.25 μmol/d in the fast-turnover tissue lycopene pool) drove tissue and plasma isomeric profiles. (13)C-Lycopene combined with physiologic compartmental modeling provides a strategy for following complex in vivo metabolic processes in humans and reveals that postabsorptive trans-to-cis-lycopene isomerization, and not the differential bioavailability of isomers, drives tissue and plasma enrichment of cis-lycopene. This trial was registered at clinicaltrials.gov as NCT01692340. © 2015 American Society for Nutrition.

Compartmental and noncompartmental modeling of 13C-lycopene absorption, isomerization, and distribution kinetics in healthy adults123

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Moran, Nancy E; Cichon, Morgan J; Riedl, Kenneth M; Grainger, Elizabeth M; Schwartz, Steven J; Novotny, Janet A; Erdman, John W; Clinton, Steven K

2015-01-01

Background: Lycopene, which is a red carotenoid in tomatoes, has been hypothesized to mediate disease-preventive effects associated with tomato consumption. Lycopene is consumed primarily as the all-trans geometric isomer in foods, whereas human plasma and tissues show greater proportions of cis isomers. Objective: With the use of compartmental modeling and stable isotope technology, we determined whether endogenous all-trans-to-cis-lycopene isomerization or isomeric-bioavailability differences underlie the greater proportion of lycopene cis isomers in human tissues than in tomato foods. Design: Healthy men (n = 4) and women (n = 4) consumed 13C-lycopene (10.2 mg; 82% all-trans and 18% cis), and plasma was collected over 28 d. Unlabeled and 13C-labeled total lycopene and lycopene-isomer plasma concentrations, which were measured with the use of high-performance liquid chromatography–mass spectrometry, were fit to a 7-compartment model. Results: Subjects absorbed a mean ± SEM of 23% ± 6% of the lycopene. The proportion of plasma cis-13C-lycopene isomers increased over time, and all-trans had a shorter half-life than that of cis isomers (5.3 ± 0.3 and 8.8 ± 0.6 d, respectively; P lycopene bioavailability and endogenous trans-to-cis-lycopene isomerization was predictive of plasma 13C and unlabeled cis- and all-trans-lycopene concentrations. Although the bioavailability of cis (24.5% ± 6%) and all-trans (23.2% ± 8%) isomers did not differ, endogenous isomerization (0.97 ± 0.25 μmol/d in the fast-turnover tissue lycopene pool) drove tissue and plasma isomeric profiles. Conclusion: 13C-Lycopene combined with physiologic compartmental modeling provides a strategy for following complex in vivo metabolic processes in humans and reveals that postabsorptive trans-to-cis-lycopene isomerization, and not the differential bioavailability of isomers, drives tissue and plasma enrichment of cis-lycopene. This trial was registered at clinicaltrials.gov as NCT01692340. PMID

SIFAT FUNGSIONAL PRODUK INTERAKSI FRAKSI GLOBULIN 7S KOMAK (Dolichos lablab DAN GUM XANTAN [Functional Properties of the Interaction Product Between Globulin of 7S Fraction of Lablab Bean (Dolichos lablab with Xantan Gum

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Sukamto1*

2009-12-01

Full Text Available Lablab bean (Dolichos lablab seeds is a potential source of protein globulin.The bean’s protein content is 20.86 %, and the amount of globulin was more than 60% from the total protein, having major fractions of 7S and 11S. The objectives of this research were to explore the 7S globulin fractions, to study interaction between 7S globulin fractions with xanthan gum, and to observe the functional properties of the product of the interaction. The research was conducted in 2 steps. The first step was to fractionate the 7S fractions from globulin. The second steps was to interact 7S globulin fraction with xanthan gum. The yield of these interaction were examined for its physicochemical and functional properties. The results showed that the 7S globulin fractions could be interacted by xanthan gum at pH 7. The interacted product of globulin 7S fraction 10 % with xanthan gum 0,75 % had good functional properties than globulin 7S fraction, such as oil holding capacity, foaming capacity, and emulsion activity. Water holding capacity could not be detected because the yield became soluble. However,the foaming and emulsifying stability were still lower than those of soybean protein isolates. The research concluded that xanthan gum could be used to improve the physicochemical and functional properties of globulin 7S fraction.

Antidiabetic effects of Artemisia sphaerocephala Krasch. gum, a novel food additive in China, on streptozotocin-induced type 2 diabetic rats.

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Xing, Xiao-Hui; Zhang, Zheng-Mao; Hu, Xin-Zhong; Wu, Rui-Qin; Xu, Chao

2009-09-25

Since ancient times, practicians of traditional Chinese medicine have discovered that Artemisia sphaerocephala Krasch. (Asteraceae) seed powder was useful for the treatment of diabetes. Artemisia sphaerocephala Krasch. gum (ASK gum), which is extracted from seed powder of the plant, is a novel food additive favored by the food industry in China. The objective of this study was to determine the antidiabetic function of ASK gum on type 2 diabetes. Type 2 diabetic rat model was induced with high fat diet and low dose of streptozotocin (STZ). The effects of ASK gum on hyperglycemia, hyperlipemia, insulin resistance, and liver fat accumulation in type 2 diabetic rats were evaluated. The results were compared to those of normal rats and diabetic rats treated with metformin. The addition of ASK gum to the rats' food supply significantly lowered fasting blood glucose, glycated serum protein, serum cholesterol, and serum triglyceride in type 2 diabetic rats, and significantly elevated liver glucokinase, liver glycogen, and serum high density protein cholesterol in the diabetic rats. ASK gum significantly reduced insulin resistance and liver fat accumulation of type 2 diabetes. Artemisia sphaerocephala Krasch. gum can alleviate hyperglycemia, hyperlipemia and insulin resistance of type 2 diabetes.

Studies on some Physicochemical Properties of the Plant Gum ...

African Journals Online (AJOL)

A. senegal, A. sieberiana and A. nilotica) in Batagarawa, Katsina State, were determined and compared. Data generated from the study confirm that there are a number of physicochemical differences between the gum exudates.

Synthesis, characterization of thiolated karaya gum and evaluation of effect of pH on its mucoadhesive and sustained release properties.

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Bahulkar, Swati S; Munot, Neha M; Surwase, Sachin S

2015-10-05

Present study aims at synthesis and characterization of thiolated gum karaya by reacting karaya gum with 80% thioglycolic acid resulting in esterification and immobilization of thiol groups on polymeric backbone. Immobilized thiol groups were found to be 5.026 mM/g determined by Ellman's method. It was characterized by FTIR, DSC and XRD. Directly compressible tablets prepared using thiolated gum displayed more disintegration time, swelling and mucoadhesion with increase in pH of medium simulating gastric and intestinal environment than plain gum. Controlled drug release for more than 24h by Fickian diffusion following Korsemeyer-Peppas model was observed with Metoprolol Succinate as a model drug as compared to plain gum which released more than 90% of the drug within 2h. Synthesized thiomer showed no cytotoxicity determined using HepG2 cell line. According to these results, thiolated gum karaya seems to be promising excipient for the development of mucoadhesive drug delivery systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Carbon nanotube modification using gum arabic and its effect on the dispersion and tensile properties of carbon nanotubes/epoxy nanocomposites.

Science.gov (United States)

Kim, Man Tae; Park, Ho Seok; Hui, David; Rhee, Kyong Yop

2011-08-01

In this study, the effects of a MWCNT treatment on the dispersion of MWCNTs in aqueous solution and the tensile properties of MWCNT/epoxy nanocomposites were investigated. MWCNTs were treated using acid and gum arabic, and MWCNT/epoxy nanocomposites were fabricated with 0.3 wt.% unmodified, oxidized and gum-treated MWCNTs. The dispersion states of the unmodified, oxidized, and Gum-treated MWCNTs were characterized in distilled water. The tensile strengths and elastic modulus of the three nanocomposites were determined and compared. The results indicated that the gum treatment produced better dispersion of the MWCNTs in distilled water and that gum-treated MWCNT/epoxy nanocomposites had a better tensile strength and elastic modulus than did the unmodified and acid-treated MWCNT/epoxy nanocomposites. Scanning electron microscope examination of the fracture surface showed that the improved tensile properties of the gum-treated MWCNT/epoxy nanocomposites were attributed to the improved dispersion of MWCNTs in the epoxy and to interfacial bonding between nanotubes and the epoxy matrix.

Changes in Atmospheric Butanes and Pentanes and Their Isomeric Ratios in the Continental United States

Science.gov (United States)

Rossabi, Sam; Helmig, Detlev

2018-04-01

Nonmethane hydrocarbons have been used as tracers in research on emissions and atmospheric oxidation chemistry. This research investigates source region mixing ratio trends of the nonmethane hydrocarbons i-butane, n-butane, i-pentane, and n-pentane, and the (i/n) isomeric ratios of these compounds between 2001 and 2015. Data collected at Photochemical Assessment Monitoring Stations, mandated by the U.S. Environmental Protection Agency in ozone nonattainment areas, and data collected at Global Greenhouse Gas Reference Network sites within the National Oceanic and Atmospheric Administration network, and analyzed at the Institute of Arctic and Alpine Research at the University of Colorado-Boulder, were examined. Among all considered species, linear regression analyses on concentration time series had negative slopes at 81% of sites, indicating predominantly declining butane and pentane atmospheric concentrations. Mostly negative slopes (78% of sites) were found for the (i/n) butane and pentane isomeric ratios, including all six and seven statistically significant (i/n) butane and pentane trends, respectively. Over the 15 year investigation period and averaged over all sites, total relative changes were 30 and 45% for the (i/n) ratios of butanes and pentanes, respectively, with a relative increase in the prominence of the n-isomers. Most likely causes include changing isomeric ratios in gasoline sector emissions, and increasing influence of oil and natural gas industry emissions. Changes in concentrations and isomeric ratios depend on proximity of contributing emission sources to measurement sites.

Phase behavior, rheological characteristics and microstructure of sodium caseinate-Persian gum system.

Science.gov (United States)

Sadeghi, Farzad; Kadkhodaee, Rassoul; Emadzadeh, Bahareh; Phillips, Glyn O

2018-01-01

In this study, the phase behavior of sodium caseinate-Persian gum mixtures was investigated. The effect of thermodynamic incompatibility on phase distribution of sodium caseinate fractions as well as the flow behavior and microstructure of the biopolymer mixtures were also studied. The phase diagram clearly demonstrated the dominant effect of Persian gum on the incompatibility of the two biopolymers. SDS-PAGE electrophoresis indicated no selective fractionation of sodium caseinate subunits between equilibrium phases upon de-mixing. The microstructure of mixtures significantly changed depending on their position within the phase diagram. Fitting viscometric data to Cross and Bingham models revealed that the apparent viscosity, relaxation time and shear thinning behavior of the mixtures is greatly influenced by the volume ratio and concentration of the equilibrium phases. There is a strong dependence of the flow behavior of sodium caseinate-Persian gum mixtures on the composition of the equilibrium phases and the corresponding microstructure of the system. Copyright © 2017. Published by Elsevier Ltd.

Pistachio (Pistacia vera L.) gum: a potent inhibitor of reactive oxygen species.

Science.gov (United States)

Sehitoglu, M Hilal; Han, Hatice; Kalin, Pınar; Gülçin, İlhami; Ozkan, Ali; Aboul-Enein, Hassan Y

2015-04-01

In the present study, in order to evaluate antioxidant and radical scavenging properties of Pistachio gum (P-Gum), different bioanalytical methods such as DPPH(•) scavenging activity, DMPD(•+) radical scavenging activity, total antioxidant activity determination by ferric thiocyanate, reducing ability Fe(3+)-Fe(2+) transformation, Cuprac and FRAP assays, O2(•-) scavenging by riboflavin-methionine-illuminate system and ferrous ions (Fe(2+)) chelating activities by 2,2'-bipyridyl reagent were performed separately. P-Gum inhibited 54.2% linoleic acid peroxidation at 10 µg/ml concentration. On the other hand, BHA, BHT, α-tocopherol and trolox, pure antioxidant compounds, indicated inhibition of 80.3%, 73.5%, 36.2% and 72.0% on peroxidation of linoleic acid emulsion at the same concentration, respectively. In addition, all of sample had an effective DPPH(•), DMPD(•+) and O2(•-) scavenging, Fe(3+) reducing power by Fe(3+)-Fe(2+) transformation and FRAP assay, Cu(2+) reducing ability by Cuprac method and Fe(2+) chelating activities.

Enhanced transport of zerovalent iron nanoparticles in saturated porous media by guar gum

International Nuclear Information System (INIS)

Tiraferri, Alberto; Sethi, Rajandrea

2009-01-01

In order to ensure adequate mobility of zerovalent iron nanoparticles in natural aquifers, the use of a stabilizing agent is necessary. Polymers adsorbed on the nanoparticle surface will give rise to electrosteric stabilization and will decrease attachment to the surface soil grains. Water saturated sand-packed columns were used in this study to investigate the transport of iron nanoparticle suspensions, bare or modified with the green polymer guar gum. The suspensions were prepared at 154 mg/L particle concentration and 0.5 g/L polymer concentration. Transport experiments were conducted by varying the ionic strength, ionic composition, and approach velocity of the fluid. Nanoparticle deposition rates, attachment efficiencies, and travel distances were subsequently calculated based on the classical particle filtration theory. It was found that bare iron nanoparticles are basically immobile in sandy porous media. In contrast, guar gum is able to ensure significant nanoparticle transport at the tested conditions, regardless of the chemistry of the solution. Attachment efficiency values for guar gum-coated nanoparticles under the various conditions tested were smaller than 0.066. Although the calculated travel distances may not prove satisfactory for field application, the investigation attested the promising role of guar gum to ensure mobility of iron nanoparticles in the subsurface environment.

Effects of gum chewing on postoperative bowel motility after caesarean section: a meta-analysis of randomised controlled trials.

Science.gov (United States)

Zhu, Y-P; Wang, W-J; Zhang, S-L; Dai, B; Ye, D-W

2014-06-01

Gum chewing has been reported to enhance bowel motility and reduce postoperative ileus (POI). However, the efficacy remains imprecise for women following caesarean section. To summarise and evaluate the current evidence for postoperative gum chewing on the recovery of bowel function following caesarean section. We searched studies from the following electronic databases: PubMed, EMBASE, SCOPUS and Cochrane Library from inception to 30 May 2013. We included randomised controlled trials (RCTs) of women after caesarean section; these RCTs should compared gum chewing with no gum chewing and reported on at least one of the outcomes: time to flatus, time to bowel sound, time to passing stool and length of hospital stay (LOS). Study outcomes were presented as mean differences (for continuous data) with 95% confidence interval (95% CI). The risk of bias in the study results was assessed using the assessment tool from the Cochrane Handbook. Six RCTs including 939 women were included in our meta-analysis. The pooled results demonstrated that gum chewing is superior to no gum chewing with a reduction of 6.42 hours (95% CI -7.55 to -5.29) for time to first flatus, 3.62 hours (95% CI -6.41 to -0.83) for time to first bowel sound, 6.58 hours (95% CI -10.10 to -3.07) for time to first stool and 5.94 hours (95% CI -9.39 to -2.49) for LOS. In addition, no evidence emerged for any side effects caused by gum chewing. The current evidence suggests that gum chewing is associated with early recovery of bowel motility and shorter LOS for women after caesarean section. This safe and inexpensive intervention should be included in routine postoperative care following a caesarean section. © 2014 Royal College of Obstetricians and Gynaecologists.

Mutanase-containing chewing gum: A new potential approach for prevention of dental caries

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Jafar Kolahi

2013-01-01

Full Text Available Introduction: Study on the effect of topically applied mutanase on plaque formation and caries in rats showed strong inhibition of dental caries. Furthermore, it has been shown that the presence of mutanase in dental plaque may affect the synthesis and structure of sticky, extracellular glucans. The Hypothesis: Mutanase can be easily added to gum base. After chewing of mutanase-containing chewing gum, the enzyme will be released into the oral cavity. Mutanase will hydrolyze sticky, extracellular glucans, e.g., mutan inhibiting cariogenic bacteria to cohere/adhere and form plaque. Evaluation of the Hypothesis: The main challenge with this hypothesis is the source of mutanase. It can be obtained from Paenibacillus sp. MP-1 or Trichoderma harzianum F-340. Directly compressible medicated chewing gum bases can be used to avoid inactivation of mutanase during the manufacturing process.

Effect of different radiations on some physico-chemical properties of gum Arabic (Acacia senegal (L.) Wild)

International Nuclear Information System (INIS)

Elamin, R. M.

2001-07-01

Seven different Acacia senegal gum samples namely A1, A2, A3, A4, A5, A6, and A7 were collected from different trees in the same forest growing in Eldmazein season 1994/ 1995. Some physicochemical and functional properties were investigated i. e. moisture content, nitrogen content, specific rotation, molecular weight, emulsifying stability and water holding capacity. Also the effect of radiation from different sources gammaγ, ultraviolet (UV) and infra-red (IR) radiations with various doses i.e 150, 325 and 500 gray, 2,4 and 6 hours and 80, 105 and 140 C, respectively on some physicochemical and functional properties and component sugars of gum samples in solid from and solution of different concentrations were studied. Statistical analysis showed significant differences (P≤0.05) between all of these seven samples in their physicochemical and functional properties except in ph value. Also Ph values were not affected by different doses of γ, UV and IR radiations used in this study. Results showed that the moisture content, ash, nitrogen content and emulsifying stability were not affected γ( 60 (Co) irradiation where solid and aqueous solution of gum samples showed significant differences (P≤0.05) in specific rotation, intrinsic and molecular weight when exposed to various doses of γrays. Statistical analysis showed insignificant differences (P≤0.05) between the whole and irradiated solid gum by UV radiation on ash, nitrogen content and emulsifying stability. But there was a little decrease as radiation time increase on the moisture content. Reducing sugars and solubility were decreased from 1.88 % and 97.19 % of whole gum to 0.16 % and 84.1 % of gum irradiated by IR radiation at 140 C, respectively while moisture content reduced from 10.7 % to 0.4 %. Maximum absorbance of UV spectrum of the whole gum was reported at the wave length 280 nm. UV absorbance was not affected by Υand UV radiations while it increased of temperature. Thin layer chromatography

Destabilization in the isomeric nitrobenzonitriles: an experimental thermochemical study

International Nuclear Information System (INIS)

Roux, Maria Victoria; Jimenez, Pilar; Davalos, Juan Z.; Temprado, Manuel; Liebman, Joel F.

2003-01-01

The enthalpies of combustion and of sublimation, respectively, of the three isomeric nitrobenzonitriles have been measured: o-, {(-3456.3±2.9), (88.1±1.4)} kJ·mol -1 ; m-, {(-3442.8±3.3), (92.8±0.3)} kJ·mol -1 ; p-, {(-3448.2±3.6), (91.1±1.3)} kJ·mol -1 . In turn, from these values, the standard molar enthalpies of formation for the condensed and gaseous state, respectively, have been derived: o-, {(130.1±3.1), (218.2±3.4)} kJ·mol -1 ; m-, {(116.5±3.5), (209.3±3.5)} kJ·mol -1 ; p-, {(122.0±3.8), (213.1±4.0)} kJ·mol -1 . Destabilization energies associated with the presence of the two electron-withdrawing groups have been determined, for o-, m-, and p-nitrobenzonitrile, {(17.6±4.1), (8.7±4.2), and (12.5±4.6)} kJ·mol -1 , respectively, and are consistent with those obtained for the corresponding sets of isomeric methyl benzenedicarboxylates, dicyanobenzenes, dinitrobenzenes, and (neutral and ionized) nitrobenzoic acids

The influence of guar gum on textural and sensory properties of rolls made from semi-finished frozen products

Directory of Open Access Journals (Sweden)

Pavlína Boudová Pečivová

2014-07-01

Full Text Available Textural and sensory properties of rolls produced from semi-finished frozen products with additions of guar gum were assessed. A commercial wheat flour T 512, ingredients such as yeast Saccharomyces cerevisiae, rapeseed oil, sodium chloride were used for preparing dough and final products. Guar gum and commercial additive Trial RC2 were used as additives for production. The textural properties of rolls were measured by a TA-XT Plus Texture Analyzer. All samples were evaluated by selected assessors. A five-point hedonic scale was used for evaluation characteristics such as taste, pliancy, texture, porosity, stickiness, gumminess, crispness and quality. The obtained data showed nonsignificant difference in moisture of rolls after baking and 3 days after baking. Control sample of rolls had higher firmness in comparison to other samples with guar gum after baking. Samples of rolls with higher addition of guar gum (10 g.kg-1 and 15 g.kg-1 had less firmness in comparison to control sample and sample with 5 g.kg-1 of guar gum. Sensory analysis showed negligible differences among all samples in monitored characteristics. Sensory assessors evaluated all samples as identical. Increased addition of guar gum in rolls led to the extension of shelf life (lower firmness at unchanged sensory properties of the rolls.

Preparation and In-Vitro Evaluation of Sustained Release Matrix Diclofenac Sodium Tablets Using HPMC KM 100 and Gums

Directory of Open Access Journals (Sweden)

Zafar Iqbal, Raza Khan, Fazli Nasir, Jamshaid Ali Khan, Lateef Ahmad, Abad Khan, Yaser Shah

2010-12-01

Full Text Available Objectives: The impact of hydroxypropylmethyl cellulose(HPMC K 100M alone and in combination with the guar gum,xanthan gum and gum tragacanth on the release of the diclofenac sodium matrix tablets were evaluated.Materials and Methods: The granules were prepared using wet granulation method and compressed into tablets using different ratio of drug and gum ratio. The physical properties of the tablets were within acceptable pharmacopeial limits.The release profiles of the matrix tablets were evaluated in vitro,using USP dissolution apparatus II (paddle method.Results: The formulations containing HPMC K 100M drug ratio1:1.3 and 1:1.6 and formulations containing HPMC, gum and drug with different ratio also sustained the release of diclofenac sodium for 12 hours. The mechanism of drug release from the matrix tablets was studied using Zero order, First order, Higuchi and Korsmeyer’s models using regression coefficient method. The stability of the selected formulations was evaluated at 40˚C and 70% RH for 6 months.Conclusions: HPMC K100M alone and in combination with natural gums as the retarding material retarded the release upto 12 hours and showed little deviation from the theoretical release pattern.

Demand characteristics, pre-test attitudes and time-on-task trends in the effects of chewing gum on attention and reported mood in healthy volunteers.

Science.gov (United States)

Allen, A P; Smith, A P

2012-10-01

Previous research has indicated that chewing gum enhances reported alertness, but has variable effects on attention. Demand characteristics may explain these effects. The current study investigated the effects of gum and demand characteristics on attention and reported mood over time. Participants completed measures of mood and attention, with and without chewing gum. To manipulate demand characteristics, they were told that the hypothesised effect of gum was either positive or negative, or no hypothesis was mentioned. Attitudes towards gum were assessed pre- and post-manipulation. Gum increased reported alertness; this effect was only significant for positive and neutral demand characteristics. Vigilance accuracy was reduced for chewing gum, but only in the fourth minute of the task, and gum reduced focussed attention accuracy, but only for the first 64 trials. Demand characteristics did not moderate time-on-task effects. Gum improved selective attention. A positive effect on response organisation was observed; this was significant when demand characteristics and pre-test attitudes to gum were both negative. The results suggest that demand characteristics moderate effects on self-reported alertness and response organisation, but cannot explain time-on-task effects or variable main effects on other aspects of attention. Copyright © 2012 Elsevier Ltd. All rights reserved.

Light-induced linkage isomerization of photochromic [Ru(bpy){sub 2}(R-OSO)]{sup +} compounds

Energy Technology Data Exchange (ETDEWEB)

Springfeld, Kristin; Dieckmann, Volker; Eicke, Sebastian; Imlau, Mirco [Department of Physics, University of Osnabrueck (Germany); Rack, Jeffrey J. [Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio (United States)

2010-07-01

Ruthenium sulfoxides exhibit light-induced linkage isomerization of the SO-bond with remarkable photosensitivity S=(0.25{+-}0.03) Ws cm{sup -1} and extended lifetimes of the related metastable states in the order of 10{sup 4} s. The isomerization is accompanied with tremendous changes of the optical extinction up to 9350 cm{sup -1} mol{sup -1} thus enabling the study of linkage isomerization by means of time-resolved optical spectroscopy. Here, the influence of ligand substitution is studied via inspection of the photosensitivity and the generation and relaxation dynamics of the photochromic response as a function of temperature (pump at {lambda}=405 nm, probe at {lambda}=532 nm). The spectra of the modified compounds, where ligands R=Bn, BnCl, and BnMe were attached to OSO, were compared with the reference system [Ru(bpy){sub 2}(OSO)]{sup +}. It turns out, that the new ligands affect the absorption features and the photosensitivity of the system only slightly. In contrast, a strong influence of the thermal relaxation of the metastable states is uncovered. Remarkably, the influence on the frequency factors is much more pronounced than on the activation energies achieved by Arrhenius' law.

Investigation of the interaction between isomeric derivatives and human serum albumin by fluorescence spectroscopy and molecular modeling

Energy Technology Data Exchange (ETDEWEB)

Wang, Ruiyong, E-mail: wangry@zzu.edu.cn; Dou, Huanjing; Yin, Yujing; Xie, Yuanzhe; Sun, Li; Liu, Chunmei; Dong, Jingjing; Huang, Gang; Zhu, Yanyan; Song, Chuanjun, E-mail: chjsong@zzu.edu.cn; Chang, Junbiao, E-mail: changjunbiao@zzu.edu.cn

2014-10-15

In this paper, we have synthesized 9H-pyrrolo[1,2-a]indol-9-ones and the isomeric indeno[2,1-b]pyrrol-8-ones. The interactions of human serum albumin with series of isomeric derivatives have been studied by spectrophotometric methods. Results show the intrinsic fluorescence is quenched by the derivatives with a static quenching procedure. The thermodynamics parameters indicate that van der Waals forces and hydrogen bonds play a major role in the interactions. The results of synchronous fluorescence spectra demonstrate that the microenvironments of Trp residue of human serum albumin are disturbed by most derivatives. Thermodynamic results showed that the 9H-pyrrolo[1,2-a]indol-9-ones are stronger quenchers and bind to human serum albumin with the higher affinity than isomeric indeno[2,1-b]pyrrol-8-ones. The influence of molecular structure on the binding aspects has been investigated. - Highlights: • The interactions between isomeric derivatives and HSA have been investigated. • Results reveal that 9H-pyrrolo[1,2-a]indol-9-ones are stronger quenchers for HSA. • Hydrogen bonds and van der Waals forces play major role in the binding process. • The influence of molecular structure on the binding aspects has been investigated. • The binding study was also modeled by molecular docking.

Investigation of the interaction between isomeric derivatives and human serum albumin by fluorescence spectroscopy and molecular modeling

International Nuclear Information System (INIS)

Wang, Ruiyong; Dou, Huanjing; Yin, Yujing; Xie, Yuanzhe; Sun, Li; Liu, Chunmei; Dong, Jingjing; Huang, Gang; Zhu, Yanyan; Song, Chuanjun; Chang, Junbiao

2014-01-01

In this paper, we have synthesized 9H-pyrrolo[1,2-a]indol-9-ones and the isomeric indeno[2,1-b]pyrrol-8-ones. The interactions of human serum albumin with series of isomeric derivatives have been studied by spectrophotometric methods. Results show the intrinsic fluorescence is quenched by the derivatives with a static quenching procedure. The thermodynamics parameters indicate that van der Waals forces and hydrogen bonds play a major role in the interactions. The results of synchronous fluorescence spectra demonstrate that the microenvironments of Trp residue of human serum albumin are disturbed by most derivatives. Thermodynamic results showed that the 9H-pyrrolo[1,2-a]indol-9-ones are stronger quenchers and bind to human serum albumin with the higher affinity than isomeric indeno[2,1-b]pyrrol-8-ones. The influence of molecular structure on the binding aspects has been investigated. - Highlights: • The interactions between isomeric derivatives and HSA have been investigated. • Results reveal that 9H-pyrrolo[1,2-a]indol-9-ones are stronger quenchers for HSA. • Hydrogen bonds and van der Waals forces play major role in the binding process. • The influence of molecular structure on the binding aspects has been investigated. • The binding study was also modeled by molecular docking

Effect of maltitol-containing chewing gum use on the composition of dental plaque microbiota in subjects with active dental caries.

Science.gov (United States)

Prosdocimi, Erica M; Kistler, James O; Moazzez, Rebecca; Thabuis, Clementine; Perreau, Caroline; Wade, William G

2017-01-01

Background : Sugar alcohols such as xylitol are incorporated in a number of oral hygiene products for their anti-cariogenic properties while chewing gum is known to be beneficial to oral hygiene. Objective : The aim of this study was to determine the composition of the dental plaque microbiota in patients with active caries before and after using a chewing gum supplemented with maltitol. Design : Forty subjects with active caries were randomly allocated to chew maltitol gum or gum base for two weeks. A healthy control group used gum base for two weeks. Plaque samples were collected before and after treatment and the microbiota analysed by pyrosequencing of 16S rRNA genes. Results : A total of 773,547 sequences were obtained from 117 samples. There was no difference in structure of the bacterial communities between groups (AMOVA). There was a significant difference in community membership between groups, (AMOVA, p=0.009). There was a significant difference between the control group after treatment and the maltitol patient group after treatment (p<0.001). A. naeslundii HOT-176 and Actinomyces HOT-169 were significantly reduced following use of maltitol chewing gum in patients. Conclusions : This study has shown that chewing gum containing maltitol had minor effects on the composition of the plaque microbiome.

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

Science.gov (United States)

Mahfoudhi, Nesrine; Chouaibi, Moncef; Hamdi, Salem

2014-01-01

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

Contribution of the cashew gum (Anacardium occidentale L.) for development of layer-by-layer films with potential application in nanobiomedical devices

Energy Technology Data Exchange (ETDEWEB)

Araujo, I.M.S. [Departamento de Quimica, Centro de Ciencias da Natureza, CCN, Universidade Federal do Piaui, UFPI, Teresina, PI, 64049-550 (Brazil); Nucleo de Pesquisa em Biodiversidade e Biotecnologia, BIOTEC, Campus Parnaiba, CMRV, Universidade Federal do Piaui, UFPI, Parnaiba, PI, 64202-020 (Brazil); Zampa, M.F. [Nucleo de Pesquisa em Biodiversidade e Biotecnologia, BIOTEC, Campus Parnaiba, CMRV, Universidade Federal do Piaui, UFPI, Parnaiba, PI, 64202-020 (Brazil); Campus Parnaiba, Instituto Federal de Educacao Ciencia e Tecnologia do Piaui, IFPI, Parnaiba, PI, 64210-260 (Brazil); Moura, J.B.; Santos, J.R. dos [Departamento de Quimica, Centro de Ciencias da Natureza, CCN, Universidade Federal do Piaui, UFPI, Teresina, PI, 64049-550 (Brazil); Eaton, P. [REQUIMTE, Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre, Porto, 4169-007 (Portugal); Zucolotto, V. [Grupo de Biofisica Molecular Sergio Mascarenhas, Instituto de Fisica de Sao Carlos, IFSC, USP, Sao Carlos, SP, 13566-590 (Brazil); and others

2012-08-01

The search for bioactive molecules to be employed as recognition elements in biosensors has stimulated researchers to pore over the rich Brazilian biodiversity. In this sense, we introduce the use of natural cashew gum (Anacardium occidentale L.) as an active biomaterial to be used in the form of layer-by-layer films, in conjunction with phthalocyanines, which were tested as electrochemical sensors for dopamine detection. We investigated the effects of chemical composition of cashew gum from two different regions of Brazil (Piaui and Ceara states) on the physico-chemical characteristics of these nanostructures. The morphology of the nanostructures containing cashew gum was studied by atomic force microscopy which indicates that smooth films punctuated by globular features were formed that showed low roughness values. The results indicate that, independent of the origin, cashew gum stands out as an excellent film forming material with potential application in nanobiomedical devices as electrochemical sensors. Highlights: Black-Right-Pointing-Pointer This study focused on the use of cashew gum for the formation of LbL films. Black-Right-Pointing-Pointer LbL films containing cashew gums were investigated by AFM and cyclic voltammetry. Black-Right-Pointing-Pointer Cashew gum contributed to obtain stable films with well-defined redox processes. Black-Right-Pointing-Pointer Cashew gum films detected dopamine in low concentrations. Black-Right-Pointing-Pointer These LbL films presented potential application in nanobiomedical devices.

Contribution of the cashew gum (Anacardium occidentale L.) for development of layer-by-layer films with potential application in nanobiomedical devices

International Nuclear Information System (INIS)

Araújo, I.M.S.; Zampa, M.F.; Moura, J.B.; Santos, J.R. dos; Eaton, P.; Zucolotto, V.

2012-01-01

The search for bioactive molecules to be employed as recognition elements in biosensors has stimulated researchers to pore over the rich Brazilian biodiversity. In this sense, we introduce the use of natural cashew gum (Anacardium occidentale L.) as an active biomaterial to be used in the form of layer-by-layer films, in conjunction with phthalocyanines, which were tested as electrochemical sensors for dopamine detection. We investigated the effects of chemical composition of cashew gum from two different regions of Brazil (Piauí and Ceará states) on the physico-chemical characteristics of these nanostructures. The morphology of the nanostructures containing cashew gum was studied by atomic force microscopy which indicates that smooth films punctuated by globular features were formed that showed low roughness values. The results indicate that, independent of the origin, cashew gum stands out as an excellent film forming material with potential application in nanobiomedical devices as electrochemical sensors. Highlights: ► This study focused on the use of cashew gum for the formation of LbL films. ► LbL films containing cashew gums were investigated by AFM and cyclic voltammetry. ► Cashew gum contributed to obtain stable films with well-defined redox processes. ► Cashew gum films detected dopamine in low concentrations. ► These LbL films presented potential application in nanobiomedical devices.

Computational Studies of Bridging Structures and Isomerism in Substituted Disilynes.

Science.gov (United States)

Serafin, Lukasz M; Law, Mark M; van Mourik, Tanja

2013-06-11

The substituted disilyne molecules, Si2Li2 and Si2HX, where X = Li, F, and Cl, have been investigated using the high-level CCSD(T) and CCSD(T)-F12 ab initio methods. The calculations have found or confirmed the existence of several isomeric forms and transition states for each molecule. Optimized geometries, relative energies, and harmonic vibration frequencies are reported. Bridging structures exist in all cases. Comparisons are made with existing literature results for the related Si2H2, C2X2, and C2HX isomerizing systems. Additionally, CCSD(T) and CCSD(T)-F12 calculations were performed for Si2H2, for which experimental spectroscopic data are available. Results calculated with CCSD(T)-F12 and the cc-pVTZ-F12 basis set are of comparable quality as those computed with CCSD(T) and the much larger cc-pV(6+d)Z basis set, at much less computational cost. We recommend the CCSD(T)-F12/cc-pVTZ-F12 level of theory as a very attractive alternative to conventional CCSD(T).

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

Science.gov (United States)

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

2013-11-01

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. Copyright © 2013 Elsevier B.V. All rights reserved.

Effect of CMC and arabic gum in the manufacture of jackfruit velva (Artocarpus heterophyllus)

Science.gov (United States)

Yudhistira, B.; Riyadi, N. H.; Pangestika, A. D.; Pertiwi, S. R.

2018-03-01

Velva is one type of frozen dessert which is made from fruit/vegetable with ice cream maker, low fat and high fiber content. Jackfruit is a raw material for the manufacture of velva because of the high fiber content of 2.31 gr. The use of a stabilizers combination of CMC and arabic gum in the manufacture of velva will provide a better gel mix than single use. The purpose of this research is to know the influence of variation of CMC and arabic gum stabilizer on the characteristics (physical, chemical, and sensory) of jackfruit velva (Artocarpus heterophyllus) and determine variations in the most appropriate combinations of stabilizers to produce jackfruit velva with the best quality. This research applied Completely Randomized Design consist of one factor which is the combination of CMC and arabic gum levels in the making of jackfruit velva with two replicates and two replications of the analysis. The data obtained then analyzed statistically using one way analysis of variance (ANOVA), when there is a significant difference, then followed by Duncan’s Multiple Range Test (DMRT) at significance level of 0.05. The results of this study concluded that the jackfruit velva with the addition of various concentrations of CMC and arabic gum is significantly affecting the taste, texture and overall parameters, but no significant difference on the color and flavor parameters of jackfruit velva. Based on the results of physical characteristics, chemical and sensory jackfruit velva with the addition of a stabilizing concentration of CMC and arabic gum 1: 1 result in best jackfruit velva. The best jackfruit velva with stabilizing the concentration of CMC and arabic gum 1: 1 contains a water content of 61.95%, dietary fiber 2.231%, total dissolved solids 20.38 °Brix, overrun 19.709%, meltdown 28.215 minutes. As for the color attribute score 3.72; Taste 4; flavor 3.60; Texture 3.68, and overall 3.88.

Isomeric Diruthenium Complexes Bridged by Deprotonated Indigo in cis and trans Configuration

Czech Academy of Sciences Publication Activity Database

Chatterjee, M.; Ghosh, P.; Beyer, K.; Paretzki, A.; Fiedler, Jan; Kaim, W.; Lahiri, G. K.

2018-01-01

Roč. 13, č. 1 (2018), s. 118-125 ISSN 1861-4728 Institutional support: RVO:61388955 Keywords : isomerism * ruthenium * spectroelectrochemistry * structure Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 4.083, year: 2016

Effects of sugar-free chewing gum sweetened with xylitol or maltitol on the development of gingivitis and plaque: a randomized clinical trial.

Science.gov (United States)

Keukenmeester, R S; Slot, D E; Rosema, N A M; Van Loveren, C; Van der Weijden, G A

2014-11-01

The objective of this study was to test the effect of sugar-free chewing gum sweetened with xylitol or maltitol compared to the use of a gum base or no gum on gingivitis and plaque scores under both brushing and non-brushing circumstances. The design of the study was a four-group, double-blinded, randomized controlled study with a 3-week duration. In each group, the participants did not brush the teeth in the lower jaw designated to develop experimental gingivitis, while maintaining normal oral hygiene procedures in the upper jaw. After professional dental prophylaxis, the participants were allocated into one of four groups (xylitol, maltitol, gum base or no gum). Chewing gum was used five times a day for 10 min. 220 participants completed the study and provided evaluable data. The increase in bleeding on marginal probing (BOMP) and plaque scores (PS) in the non-brushed (lower) jaw with experimental gingivitis was significant in all groups (P xylitol and maltitol group was significantly lower. In the brushed upper jaw, no significant changes for BOMP were observed from the baseline to the end point of the study, and there were no significant differences in BOMP and PS between the groups. In circumstances where regular brushing is performed, no effect of chewing gum was observed on bleeding and plaque scores. In the absence of brushing, chewing xylitol or maltitol gum provided a significant inhibitory effect on gingivitis scores compared to chewing gum base. The difference when compared to the group not using gum was not significant. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of xanthan gum on the release of strawberry flavor in formulated soy beverage.

Science.gov (United States)

Xu, Jiao; He, Zhiyong; Zeng, Maomao; Li, Bingbing; Qin, Fang; Wang, Linxiang; Wu, Shengfang; Chen, Jie

2017-08-01

The effects of xanthan gum on the release of strawberry flavor compounds in formulated soy protein isolate (SPI) beverage were investigated by headspace gas chromatography (GC). Seven strawberry flavor compounds (limonene, ethyl hexanoate, (Z)-3-hexenyl acetate, ethyl 2-methylbutanoate, ethyl butanoate, (Z)-3-hexen-1-ol and diacetyl) could be detected by GC and hence analyzed the gas-matrix partition coefficients (K). The release of flavor compounds was restrained in SPI and/or xanthan gum solution. The retention of (Z)-3-hexen-1-ol, limonene and diacetyl significantly changed (pfuraneol) accelerated the release of ester compounds to some extent in different matrices. The above results demonstrated that presence of SPI and xanthan gum could bring about an imbalance in the strawberry flavor. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thermal isomerization of azobenzenes: on the performance of Eyring transition state theory

Science.gov (United States)

Rietze, Clemens; Titov, Evgenii; Lindner, Steven; Saalfrank, Peter

2017-08-01

The thermal Z\\to E (back-)isomerization of azobenzenes is a prototypical reaction occurring in molecular switches. It has been studied for decades, yet its kinetics is not fully understood. In this paper, quantum chemical calculations are performed to model the kinetics of an experimental benchmark system, where a modified azobenzene (AzoBiPyB) is embedded in a metal-organic framework (MOF). The molecule can be switched thermally from cis to trans, under solvent-free conditions. We critically test the validity of Eyring transition state theory for this reaction. As previously found for other azobenzenes (albeit in solution), good agreement between theory and experiment emerges for activation energies and activation free energies, already at a comparatively simple level of theory, B3LYP/6-31G* including dispersion corrections. However, theoretical Arrhenius prefactors and activation entropies are in qualitiative disagreement with experiment. Several factors are discussed that may have an influence on activation entropies, among them dynamical and geometric constraints (imposed by the MOF). For a simpler model—Z\\to E isomerization in azobenzene—a systematic test of quantum chemical methods from both density functional theory and wavefunction theory is carried out in the context of Eyring theory. Also, the effect of anharmonicities on activation entropies is discussed for this model system. Our work highlights capabilities and shortcomings of Eyring transition state theory and quantum chemical methods, when applied for the Z\\to E (back-)isomerization of azobenzenes under solvent-free conditions.

Dilute solution, flow behavior, thixotropy and viscoelastic characterization of cress seed (Lepidium sativum) gum fractions

DEFF Research Database (Denmark)

Razmkhah, Somayeh; Razavi, Seyed Mohammad Ali; Mohammadifar, Mohammad Amin

2017-01-01

In this study, rheological properties of cress seed gum (CSG) and its fractions (F1, F2, F3; fractionated using stepwise extraction with water) were investigated. Cress seed gum and its fractions revealed random coil conformation in dilute regimes; chain flexibility and intrinsic viscosity...... indicated that CSG and the fractions exhibited significantly different rheological properties....

Pressure production in oral vestibule during gum chewing.

Science.gov (United States)

Nishiura, M; Ono, T; Yoshinaka, M; Fujiwara, S; Yoshinaka, M; Maeda, Y

2015-12-01

The aim of this study was to record oral vestibule pressure (OVP) by the lip and cheek contraction during gum chewing, to examine the characteristics of these pressures and coordination between the OVP and jaw movement. The subjects were eight healthy adult men (mean age of 29·3 ± 3·3 years). An experimental plate that incorporated four pressure sensors on the midline of the upper jaw (Ch. 1), upper right canine (Ch. 2), upper right first molar (Ch. 3) and upper left first molar (Ch. 4) was used for measuring OVP. The right masseter electromyogram (EMG) was recorded simultaneously. Subjects chewed gum on the right side 20 times, and eight consecutive strokes were used for the analysis of the sequential order, maximal magnitude and duration of each OVP. Onset of OVP was observed at the molar on the non-chewing side (Ch. 4) before chewing side (Ch. 3), and offset was largely simultaneous at each site. On the chewing side (Chs. 1-3), OVP onset during the interval of EMG activity reached to the peak around the end of interval and offset in the duration of EMG activity. The maximal pressure was significantly larger at Chs. 1-3 than at Ch. 4, but no significant differences were observed in duration of pressure among each site. These results suggest that OVP is coordinated with jaw movement during gum chewing, and larger pressure is produced on the chewing side than on the non-chewing side. Our findings are quantitative indices for the evaluation of lip and cheek function during mastication. © 2015 John Wiley & Sons Ltd.

Effect of incorporation of pumpkin (Cucurbita moshchata) powder and guar gum on the rheological properties of wheat flour.

Science.gov (United States)

Kundu, Himani; Grewal, Raj Bala; Goyal, Ankit; Upadhyay, Neelam; Prakash, Saurabh

2014-10-01

The present study was carried out to study the effect of incorporation of fibre rich pumpkin powder and guar gum on the farinographic characteristics of wheat flour. The flour and pumpkin powder were assessed for proximate composition, total dietary fibre, minerals and β-carotene. Pumpkin powder contained appreciable amount of fibre, minerals and β-carotene. The effects of incorporation of different levels of pumpkin powder and guar gum along with pumpkin powder on farinographic characteristics were studied. Dough development time, dough stability, time to break down and farinograph quality number increased whereas mixing tolerance index decreased with incorporation of pumpkin powder (> 5 %) and guar gum (1.0 and 1.5 %) along with pumpkin powder in the flour. Resistance to extension as well as extensibility of dough prepared increased significantly by adding pumpkin powder (5-15 %) whereas increase in resistance to extension only was noticed with inclusion of guar gum (0.5-1.5 %) to flour containing 5 % pumpkin powder. Results indicated that pumpkin can be processed to powder that can be utilized with guar gum for value addition.

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

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Sateesh Kumar Vemula

2013-01-01

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

Characterization and preliminary toxicity assay of nano-titanium dioxide additive in sugar-coated chewing gum.

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