Emerging applications of radiation-modified carrageenans

Energy Technology Data Exchange (ETDEWEB)

Abad, Lucille V., E-mail: lvabad@pnri.dost.gov.ph; Aranilla, Charito T.; Relleve, Lorna S.; Dela Rosa, Alumanda M.

2014-10-01

The Philippines supplies almost half of the world’s processed carrageenan as ingredient for different applications. In order to maintain the country’s competitive advantage, R and D on radiation processed carrageenan with various potential applications had been undertaken. PVP-carrageenan hydrogels for wound dressing had been developed. A carrageenan-based radiation dose indicator can detect radiation dose of as low as 5 kGy. Irradiated carrageenan has also been tested as plant growth promoter. Irradiated carrageenans have been found have been found to contain some antioxidant properties which increase with increasing dose and concentration. Carboxymethyl carrageenans had also been developed that shows promising effect as super water absorbent for soil conditioner in plants.

Pharmacological importance of sulphated polysaccharide carrageenan from red seaweed Kappaphycus alvarezii in comparison with commercial carrageenan.

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Suganya, Arumugampillai Manimehalai; Sanjivkumar, Muthusamy; Chandran, Manohar Navin; Palavesam, Arunachalam; Immanuel, Grasian

2016-12-01

Pharmacological properties of native carrageenan (κ) extracted from Kappaphycus alvarezii and commercial carrageenan (Sigma-Aldrich) were evaluated using in vitro antioxidant, anticancer and antidiabetic studies. Phytochemical analysis of native and commercial carrageenans showed the presence of alkaloids, saponins, steroids, gums & mucilages and carbohydrate. Both native and commercial carrageenans exhibited better antioxidant activities such as total antioxidant capacity (87±0.47 and 82.6±0.47μg A.A/g), hydroxyl radical scavenging activity (61.4±0.27 and 58.66±0.31μg/ml), nitric oxide radical scavenging activity (80.42±0.22 and 73.66±0.22μg/ml), DPPH radical scavenging activity (56.26±0.20 and 53.67±0.082μg/ml) and reducing power assay (46.57±0.32 and 42.54±0.27μg/ml) at the maximum concentration of 100μg/ml carrageenans. These results indicated that native carrageenan from K. alvarezii possessed better antioxidant potential in comparison with commercial carrageenan. Anticancer activities of both carrageenans showed excellent inhibition on the growth of breast, colon, liver and osteosarcoma cell lines at the maximum concentration of 150μg/ml. Native carrageenan exhibited an excellent anticancer activity on colon carcinoma cell lines (67.66±0.168%) with the IC 50 value of 73.87μg/ml and commercial carrageenan possessed a potent inhibition on the growth of breast cancer cell lines (67.33±0.077%) with the IC 50 value of 123.8μg/ml. These results clearly indicated the beneficial effect of native and commercial carrageenans as anticancer agents being a free radical scavenger. Anti-diabetic property of both carrageenans showed inhibition effect on α- glucosidase enzyme. The inhibitory effect depends on concentration of carrageenans and it was recorded that maximum (74.49±1.05 and 67.42±0.63) inhibitory effect of α- glucosidase enzyme at 500μg/ml concentration. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Radiation Processed Materials from Carrageenan for Agricultural Applications

International Nuclear Information System (INIS)

Abad, Lucille V.; Relleve, Lorna S.; Aranilla, Charito T.; De la Rosa, Alumanda M.

2010-01-01

The radiation degradation yield (Gd) of κ- carrageenan was determined at different conditions. The computed Gd were as follows: 2.5, 1.7 and 1.2 for solid in atmosphere, solid in vacuum and at 1% aqueous solution, respectively. Chemical structure of irradiated κ-carrageenan at different doses (1% aqueous and solid in air and in vacuum) was investigated using several methods (UV-Vis / FT-IR / NMR spectroscopy / reducing sugar analysis / sulfate and carboxylic acid analysis). The chemical and spectral analyses of the radiolytic products indicated increasing reducing sugars, carbonyl, carboxylic acids, and sulfates with increasing doses which reach a maximum level at a certain dose depending on the irradiation condition. NMR data also revealed an intact structure of the oligomer irradiated at 100 kGy in the specific fraction that contains an Mw = (3-10) kDa. (author)

Carboxymethyl Carrageenan Based Biopolymer Electrolytes

International Nuclear Information System (INIS)

Mobarak, N.N.; Jumaah, F.N.; Ghani, M.A.; Abdullah, M.P.; Ahmad, A.

2015-01-01

Highlights: • The paper highlights the potential of carboxymethyl carrageenan based on iota and kappa to be utilized as host polymer. • The highest conductivity were achieved up to ∼10 −3 S cm −1 by carboxymethyl carrageenan without the addition of plasticizer. • The electrochemical stability windows of the films were electrochemically stable up to 3.0 V. - Abstract: A series of biodegradable carboxymethyl carrageenan based polymer electrolytes, which are carboxymethyl kappa carrageenan (sulphate per disaccharide) and carboxymethyl iota carrageenan (two sulphates per disaccharide), have been prepared by a solution casting technique with different ratios of lithium nitrate (LiNO 3 ) salts. Interestingly, the lithium ions tended to interact with the carbonyl group in the different modes of symmetry, as observed from reflection Fourier transform infrared (ATR-FTIR) spectroscopy analysis. In the carboxymethyl kappa carrageenan electrolytes, as the concentration of LiNO 3 increased, the asymmetric stretching peak of the carbonyl bond became dominant because it can be observed clearly with the shifting of the peak from 1592 to 1602 cm −1 due to the interaction between the lithium ion and the carbonyl group, while the broad O-H stretching peak became sharp and intense. However, for the carboxymethyl iota carrageenan, the asymmetry stretching mode of the carbonyl group shifted from 1567 to 1599 cm −1 , as the salt concentration increased. The shifting of the C-O-C peak also occurred in the iota-based electrolytes. However, the changes in the peak that represented SO 4 2− symmetric stretching were only detected when the ion pair formation was observed. It was proposed that the peak shifting was due to the presence of the lithium ion pathway, forming a dative bond between the lithium and oxygen in the carbonyl group. Accordingly, as more peak shifting was observed, the number of the ion pathways also increased. This hypothesis was supported by the impedance

Radiation degradation of marine polysaccharides by low energy electron beam

International Nuclear Information System (INIS)

Yoshii, Fumio; Nagasawa, Naotsugu; Kume, Tamikazu

2003-01-01

The radiation degradations of marine polysaccharides by both gamma Co-60 and electron beam irradiations are investigated. Polysaccharides and oligosaccharides can be produced by degradation of corresponding polysaccharides including marine polysaccharides such as alginates, chitin chitosan and carrageenan. The viscosity of alginate, chitosan and carrageenan solution decreases markedly with increase of the low energy electron beam irradiation time and the beam current. Furthermore, the viscosity is reduced sharply in short time for polysaccharide solution with low concentration, for instance carrageenan solution of 1%. (author)

Synthesis and In Vitro Evaluation of Thiolated Carrageenan.

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Suchaoin, Wongsakorn; Bonengel, Sonja; Hussain, Shah; Huck, Christian W; Ma, Benjamin N; Bernkop-Schnürch, Andreas

2015-08-01

The aim of this study was to generate and characterize a thiolated carrageenan. Thiolated carrageenan (carrageenan-SH) was synthesized from kappa (κ)- and iota (ι)-carrageenan by bromine replacement of the hydroxyl moieties followed by substitution to thiol groups using thiourea. Thiolated κ- and ι-carrageenan exhibited 176.57 ± 20.11 and 109.51 ± 18.26 μmol thiol groups per gram polymer, respectively. The resazurin test in Caco-2 cells revealed no toxic effect of both thiolated carrageenans at a concentration below 0.1% (w/v). Regarding efflux pump inhibitory effect, cellular accumulation of multidrug-resistance protein 2 substrate, sulforhodamine 101, was 1.38- and 1.35-fold increased in cells treated with thiolated κ- and ι-carrageenan, respectively. Modification of κ- and ι-carrageenan led to 3.9- and 2.0-fold increase in dynamic viscosity of mucus-thiolated carrageenan mixture within 4 h. Furthermore, residence time of κ- and ι-carrageenan-SH on porcine intestinal mucosa was 6.4- and 1.8-fold prolonged, respectively, as demonstrated by rotating cylinder method, indicating improved mucoadhesive properties. Hence, thiolation of carrageenans led to novel pharmaceutical excipients for various applications. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Antioxidant activity potential of gamma irradiated carrageenan

International Nuclear Information System (INIS)

Abad, Lucille V.; Relleve, Lorna S.; Racadio, Charles Darwin T.; Aranilla, Charito T.; De la Rosa, Alumanda M.

2013-01-01

The antioxidant capacity of irradiated κ-, ι-, λ-carrageenans were investigated using the hydroxyl radical scavenging assay, reducing power assay and DPPH radical scavenging capacity assay. The degree of oxidative inhibition increased with increasing concentration and dose. The type of carrageenan had also an influence on its antioxidant activity which followed the order of lambda< iota< kappa. Increase in oxidative property with radiation dose can be attributed mainly to the depolymerization of the carrageenans with corresponding increase in reducing sugar. The antioxidant properties of these carrageenan oligomers were lower than that of ascorbic acid and galactose sugar. - Highlights: • The antioxidant capacity of gamma irradiated κ-, ι-, λ-carrageenans increased with increasing concentration and dose. • The type of carrageenan had an influence on its antioxidant activity which followed the order of lambda< iota< kappa. • Increase in oxidative property with radiation dose can be attributed mainly to the depolymerization of the carrageenans with corresponding increase in reducing sugar

Hybrid carrageenans: isolation, chemical structure, and gel properties.

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Hilliou, Loic

2014-01-01

Hybrid carrageenan is a special class of carrageenan with niche application in food industry. This polysaccharide is extracted from specific species of seaweeds belonging to the Gigartinales order. This chapter focuses on hybrid carrageenan showing the ability to form gels in water, which is known in the food industry as weak kappa or kappa-2 carrageenan. After introducing the general chemical structure defining hybrid carrageenan, the isolation of the polysaccharide will be discussed focusing on the interplay between seaweed species, extraction parameters, and the hybrid carrageenan chemistry. Then, the rheological experiments used to determine the small and large deformation behavior of gels will be detailed before reviewing the relationships between gel properties and hybrid carrageenan chemistry. © 2014 Elsevier Inc. All rights reserved.

Plant growth promoter effect of radiation degraded Kappa-carrageenan on mungbean (Vigna radiate [L.] R. Wilczek) and peanut (Arachis Hypogaea L.) plants

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Abad, L.V.; Magsino, G.; Aurigue, F.B.; Montefalcon, D.V.; Lopez, G.E.P.; Dela Cruz, R.M.M.

2015-01-01

Kappa Carrageenan are hydrophilic polymers that comprise the main structural polysaccharides of numerous species of seaweed Eucheuma. They are composed of D-galactose units linked alternately with α(1,3) D-galactose-4-sulfated and β(1-4)-3,6-anhydro-D-galactose. Earlier studies indicate that irradiated κ-carrageenan enchances the growth of some plants such as rice bokchoi, and mustard. This study aims to determine the effects of radiation modified κ-carrageenan solution on mungbean and peanut plants and to identify its effective molecular weight range as plants growth promoter. Oligomers from radiation modified κ-carrageenan solution on mungbean and peanut plants. Results on plants sprayed with PGP revealed improvement of the agronomic traits of mungbean and peanut plants. Best PGP effects were manisfested in oligo-carrageenan sprayed plants treated with inoculants + fertilizer with an increase in yield of 200% and 154% for mungbean and peanuts, respectively. Likewise, spraying with oligo-carrageenan alone increased yield by 127% and 140%. Recent studies conducted on the effect of radiation modified κ-carrageenan on rice plants indicated an average of 30% increase in yield of rice in three (3) multi-location sites (Laguna, Nueva Ecija and Bulacan). Plants indicated resistance against Tungro virus. It also showed improved stem strength, enhancing its lodging resistance. The radiation modified κ-carrageenan solution which had an Mw of 6.9 kDa was fractionated into different molecular weight cut-offs of 5 kDa, 3 kDa and 1 kDa. Analysis by gel permeation chromatography of these samples indicated Mw of 5.2 kDa, 4.0 kDa, and 3.8 kDa, respectively. Treatment of pechay by foliar spraying of these solution indicated that plant growth promoter effect increased in the order of 1kDa > 3kDa > 5kDa. (author)

Complexation between carrageenan and methylene blue for sensor design

Science.gov (United States)

Ling, Yew Pei; Heng, Lee Yook

2013-11-01

Theoretical studies on the methylene blue (MB)-carrageenans complexation at solution and solid states have been carried out via ultraviolet spectrophotoscopy and reflectometry methods. The equilibrium constant (Ka) of the MBcarrageenans complexation follows the order of Iota > Lambda > Kappa carrageenans, which indicated Iota-carrageenan forms a stable complex. MB-carrageenan complexation reaction showed decrease in Ka value from 210.71 ppm-1 to 114.57 ppm-1 when the reaction temperature increased from 298 K to 323 K. Le Chatelier's principle and mass action law explained that the MB-carrageenan complexation was an exothermic reaction (ΔH=-18.54 kJmol-1) that release heat. Thus MB-carrageenan complex was less stable at high temperature and tend to dissociate into free MB and carrageenan molecules. It was also supported by the van't Hoff equation. The reaction is a spontaneous process (ΔG=-13.23 kJmol-1) where the randomness of the molecules reduced (ΔS=-17.83 Jmol-1K-1) due to complexation. Besides, linear regression of the concentration and absorption of the MB-carrageenan reaction obeys the Beer Lambert law, which elucidated that the complexation process was not affected by any concentration dependent factors such as aggregation and self-quenching. Moreover, linear Benesi Hilderbrend plot revealed that the interaction between MB and carrageenan was a reversible and stoichiometric reaction with 1:1 ratio. However, the molar extinction coefficient (ɛ) and molar adsorption coefficient (μa) of the MB-carrageenan complex were lower compared to free MB, described that the complex was less adsorptive. The sensor constructed based on these theoretical investigations showed response behavior that was similar with solution test as both have attraction for carrageenans in the sequence of Iota-, Lambda-, Kappa- carrageenans. Likewise, carrageenan sensor was more selective towards Iota-carrageenan than to Lambda- and Kappa-carrageenans, and no response observed when

Theoretical study of hydrogen bond interactions of fluvastatin with ι-carrageenan and λ-carrageenan.

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Papadopoulos, Anastasios G; Sigalas, Michael P

2011-07-01

The binding of the reductase inhibitor drug fluvastatin, hydroxy-3-methylglutaryl coenzyme A, with the hydrophilic ι- or λ-carrageenan polymers, serving as potential controllers of the drug's release rate, have been studied at the density functional level of theory with the B3LYP exchange correlation functional. Three low energy conformers of fluvastatin have been calculated. The vibrational spectroscopic properties calculated for the most stable conformer were in satisfactory agreement with the experimental data. A series of hydrogen bonded complexes of the most stable conformer of fluvastatin anion with low molecular weight models of the polymers have been fully optimized. In almost all, intermolecular H-bonds are formed between the sulfate groups of ι- or λ-carrageenan and fluvastatin's hydroxyls, resulting in a red shift of the fluvastatin's O - H stretching vibrations. Cooperative intramolecular H-bonds within fluvastatin or ι-, λ-carrageenan are also present. The BSSE and ZPE corrected interaction energies were estimated in the range 281-318 kJ mol⁻¹ for ι-carrageenan - fluvastatin and 145-200 kJ mol⁻¹ for λ-carrageenan - fluvastatin complexes. The electron density (ρ (bcp)) and Laplacian (∇²ρ (bcp)) properties at critical points of the intermolecular hydrogen bonds, estimated by AIM (atoms in molecules) calculations, have a low and positive character (∇²ρ(bcp) > 0), consistent with the electrostatic character of the hydrogen bonds. The structural and energetic data observed, as well as the extent of the red shift of the fluvastatin's O - H stretching vibrations upon complex formation and the properties of electron density show a stronger binding of fluvastatin to ι- than to λ-carrageenan.

Effect of carrageenan on properties of biodegradable thermoplastic cassava starch/low-density polyethylene composites reinforced by cotton fibers

International Nuclear Information System (INIS)

Prachayawarakorn, Jutarat; Pomdage, Wanida

2014-01-01

Highlights: • We prepared the TPCS/LDPE composites modified by carrageenan and/or cotton fibers. • The IR O–H stretching peak of the modified composites shifts to lower wavenumber. • Stress and Young’s modulus of the modified composites increase significantly. • The modified composites degrade faster than the non-modified composite. - Abstract: Applications of biodegradable thermoplastic starch (TPS) have been restricted due to its poor mechanical properties, limited processability and high water uptake. In order to improve properties and processability, thermoplastic cassava starch (TPCS) was compounded with low-density polyethylene (LDPE). The TPCS/LDPE blend was, then, modified by a natural gelling agent, i.e. carrageenan and natural fibers, i.e. cotton fibers. All composites were compounded and processed using an internal mixer and an injection molding machine, respectively. It was found that stress at maximum load and Young’s modulus of the TPCS/LDPE composites significantly increased by the addition of the carrageenan and/or the cotton fibers. The highest mechanical properties were obtained from the TPCS/LDPE composites modified by both the carrageenan and the cotton fibers. Percentage water absorption of all of the TPCS/LDPE composites was found to be similar. All modified composites were also degraded easier than the non-modified one. Furthermore, all the composites were analyzed using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Scanning electron microscopy (SEM)

Characterization of low molecular weight fragments from gamma irradiated κ-carrageenan used as plant growth promoter

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Abad, Lucille V.; Aurigue, Fernando B.; Relleve, Lorna S.; Montefalcon, Djowel Recto V.; Lopez, Girlie Eunice P.

2016-01-01

Radiation degraded κ-carrageenan (1% solution at absorbed doses of 20 kGy and 30 kGy) were tested for its plant growth promoter (PGP) effect on pechay plants under hydroponics condition. Results revealed that higher PGP effects were found in κ-carrageenan irradiated at an absorbed dose of 30 kGy. Mw of irradiated κ-carrageenan as measured by GPC were determined to be 7362 Da and 6762 Da for 20 kGy and 30 kGy, respectively. Fractionation of the irradiated κ-carrageenan (30 kGy) was done to separate different Mw fractions using Mw cut-off filters of 1 kDa, 3 kDa, and 5 kDa. The PGP effect of the different retentates showed that biological activity in plants followed the order of 5 kDa>3 kDa>1 kDa using hydroponics condition but the reverse was observed in the order of 1 kDa>3 kDa>5 kDa when absorbed in plants by foliar spraying. GPC chromatogram indicated at least three (3) low molecular weight (LMW) fragments from radiation modified κ-carrageenan solution with an Mw<2000 Da. A fragment has also been identified with an Mw of as low as 160 Da which was produced under acidic (un-neutralized) condition. This may be attributed to the formation of 5-hydroxymethylfurfural (5-HMF).

Preparation, characterization and antibacterial activity of oxidized κ-carrageenan.

Science.gov (United States)

Zhu, Mingjin; Ge, Liming; Lyu, Yongbo; Zi, Yaxin; Li, Xinying; Li, Defu; Mu, Changdao

2017-10-15

The oxidized κ-carrageenans with different oxidation levels were prepared through the hydrogen peroxide and copper sulfate redox system. The oxidation level of oxidized κ-carrageenan was successfully controlled by adjusting the dosage of hydrogen peroxide. The results showed that the microtopography of oxidized κ-carrageenan changed from rough granules to smooth flakes, mainly resulting from the easily melting property of oxidized κ-carrageenan induced by introduced carboxyl and aldehyde groups. Especially, the antibacterial activity of oxidized κ-carrageenans against Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) was systematically investigated. The results showed that the oxidized κ-carrageenan could damage the bacterial cell wall and cytoplasmic membrane and suppress the growth of both Gram-positive and Gram-negative bacteria. The oxidized κ-carrageenan possessed broad-spectrum antibacterial activity, which may be used as a new antibacterial agent. Copyright © 2017 Elsevier Ltd. All rights reserved.

Increase in the yield of mung bean (Vigna radiata [L.] R. Wilczek) with storage of radiation-modified kappa-carrageenan

International Nuclear Information System (INIS)

Aurigue, F.B.; Montefalcon, D.R.V.; Dela Cruz, R.M.M.; Abad, L.V.

2015-01-01

Kappa-carrageenan is a sulphated polysaccharide naturally present in seaweeds. Upon gamma radiation, radiolysis produces low molecular weight κ-carrageenan with the cleavage of some of its sulphate groups. Consequently, the acidic solution may further hydrolyze κ-carrageenan. The study aims to determine the effects of application by foliar spraying of freshly prepared irradiated κ-carrageenan solution and those which has been stored for 3 months on the yield of potted mungbean (Vigna radiata) plants. Foliar application of radiation-modified κ-carrageenan solution on the Kulabo variety two weeks after sowing, at flower initiation, and at fruit formation stage resulted in 30.8% increase in pod yield and 50.2% increase in seed yield compared to plants similarly treated with NitroPlus inoculants only. Pod yield and seed yield advantage over the control plants (no inoculants and no fertilizer) were 57.2% and 83% respectively no fertilizer was used in all treatments. These result confirm the previous finding that irradiated κ-carrageenan solution sprayed every two weeks inoculants only. There was 200% yield advantage over the negative control. The increase in yield is attributed to the longer length of pod, higher number of seed per pod, heavier 100-seed weight. Interestingly, the 3 months-old solution gave better result compared to a freshly irradiated one. There was 26.5% and 26.8% difference in pod yield and seed yield, respectively. Compared with the Control plants of the Kulabo variety, those sprayed with stored κ-carrageenan solution had 105% advantage in seed yield. It was proposed that the degradation process of the oligo-κ-carrageenan continue during storage because of the acidic nature of the solution. Undoubtedly, irradiated κ-carrageenan solution has plant growth promoting activity that increase yield mung bean by spraying on the leaves at least three times before fruit development.(author)

Carrageenan is a potent inhibitor of papillomavirus infection.

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Christopher B Buck

2006-07-01

Full Text Available Certain sexually transmitted human papillomavirus (HPV types are causally associated with the development of cervical cancer. Our recent development of high-titer HPV pseudoviruses has made it possible to perform high-throughput in vitro screens to identify HPV infection inhibitors. Comparison of a variety of compounds revealed that carrageenan, a type of sulfated polysaccharide extracted from red algae, is an extremely potent infection inhibitor for a broad range of sexually transmitted HPVs. Although carrageenan can inhibit herpes simplex viruses and some strains of HIV in vitro, genital HPVs are about a thousand-fold more susceptible, with 50% inhibitory doses in the low ng/ml range. Carrageenan acts primarily by preventing the binding of HPV virions to cells. This finding is consistent with the fact that carrageenan resembles heparan sulfate, an HPV cell-attachment factor. However, carrageenan is three orders of magnitude more potent than heparin, a form of cell-free heparan sulfate that has been regarded as a highly effective model HPV inhibitor. Carrageenan can also block HPV infection through a second, postattachment heparan sulfate-independent effect. Carrageenan is in widespread commercial use as a thickener in a variety of cosmetic and food products, ranging from sexual lubricants to infant feeding formulas. Some of these products block HPV infectivity in vitro, even when diluted a million-fold. Clinical trials are needed to determine whether carrageenan-based products are effective as topical microbicides against genital HPVs.

Carrageenan: a natural seaweed polysaccharide and its applications.

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Prajapati, Vipul D; Maheriya, Pankaj M; Jani, Girish K; Solanki, Himanshu K

2014-05-25

Polysaccharides have been gaining interesting and valuable applications in the food and pharmaceutical fields. As they are derived from the natural source, they are easily available, non-toxic, cheap, biodegradable and biocompatible. Carrageenan is one among them, which fulfills the criteria of polysaccharide; it is a natural carbohydrate (polysaccharide) obtained from edible red seaweeds. The name Carrageenan is derived from the Chondrus crispus species of seaweed (Rhodophyceace) known as Carrageen Moss or Irish Moss, and Carraigin. A demand based on its application has been widely increasing in food and pharmaceutical sectors. Carrageenan has gained wide applications in experimental medicine, pharmaceutical formulations, cosmetics, and food industries. Through keen references of the reported literature on carrageenan, in this review, we have described about carrageenan, its properties, extraction and refining, and its food and pharmaceutical applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

Characterization of ι-carrageenan and its derivative based green polymer electrolytes

Energy Technology Data Exchange (ETDEWEB)

Jumaah, Fatihah Najirah; Mobaraka, Nadhratun Naiim; Ahmad, Azizan; Ramli, Nazaruddin [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor Darul Ehsan (Malaysia)

2013-11-27

The new types of green polymer electrolytes based on ι-carrageenan derivative have been prepared. ι-carrageenan act as precursor was reacted with monochloroacetic acid to produce carboxymethyl ι-carrageenan. The powders were characterized by Attenuated Total Reflection Fourier Transform infrared (ATR-FTIR) spectroscopy and {sup 1}H nuclear magnetic resonance (NMR) to confirm the substitution of targeted functional group in ι-carrageenan. The green polymer electrolyte based on ι-carrageenan and carboxymethyl ι-carrageenan was prepared by solution-casting technique. The films were characterized by electrochemical impedance spectroscopy to determine the ionic conductivity. The ionic conductivity ι-carrageenan film were higher than carboxymethyl ι-carrageenan which 4.87 ×10{sup −6} S cm{sup −1} and 2.19 ×10{sup −8} S cm{sup −1}, respectively.

Carrageenan as a dry strength additive for papermaking.

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Zhenhua Liu

Full Text Available Carrageenans are commercially important sulfated gums found in various species of red seaweeds (Rhodophyta, wherein they serve a structural function similar to that of pectins in land plants. In this study, carrageenan was used independently or in combination with cationic polyacrylamide (CPAM and/or Al2(SO43 to explore its application as a dry strength additive in papermaking. Strength index determination, ash content detection, FTIR characterization and SEM observation were performed on prepared handsheets. The results showed that with 0.6% Al2(SO43 and 0.2% carrageenan as additives, the tensile index increased by 13.53% and precipitated calcium carbonate (PCC retention increased by 57.06%. With 0.6% Al2(SO43, 0.2% carrageenan and 0.03% CPAM as additives, PCC retention increased by 121% while the tensile index did not fall compared to handsheets without additives, indicating that carrageenan could enhance the strength of handsheets and be used as an anionic dry strength agent.

Rheological properties of agar and carrageenan from Ghanaian red seaweeds

DEFF Research Database (Denmark)

Rhein-Knudsen, Nanna; Ale, Marcel Tutor; Ajalloueian, Fatemeh

2017-01-01

spectroscopy (FTIR) analysis on the hydrocolloids extracted from H. musciformis (and K. alvarezii) indicated κ-carrageenan, C. crenulata hydrocolloids were mainly ι-carrageenan, and the H. dentata hydrocolloids were agar. Gelling temperatures ranged from 32 to 36 °C for the κ-carrageenan hydrocolloid samples...... comparable with κ-carrageenan from K. alvarezii, whereas the H. dentata agar properties were different from those of a commercial agar sample. This work shows that certain red seaweed species in Ghana contain hydrocolloids with desirable properties for high value applications....... and Cryptonemia crenulata, expected to hold carrageenan, contained 21–26% by weight of galactose. A commercial Kappaphycus alvarezii carrageenan sample had 30% galactose residues by weight. Hydropuntia dentata, expected to contain agar, contained 15% by weight of galactose-monomers. Fourier transform infrared...

Potential of sago starch/carrageenan mixture as gelatin alternative for hard capsule material

Science.gov (United States)

Poeloengasih, Crescentiana Dewi; Pranoto, Yudi; Anggraheni, Frida Dwi; Marseno, Djagal Wiseso

2017-03-01

In order to replace gelatin in capsule shell production, blends of sago starch and carrageenan were developed. Films and capsules were prepared with 10% (w/v) of sago starch, 25% (w/w starch) of glycerol and various carrageenan concentration (1, 2, 3% w/w starch) in two different kappa/iota-carrageenan ratio (1:3 and 3:1). The resulted films and capsules were characterized by mechanical property, water vapor and oxygen permeability. In addition, moisture absorption and solubility of capsule in acid solution were investigated. The results reveal that addition of carrageenan makes the films stronger and less permeable. Higher kappa-carrageenan content improved tensile strength and barrier properties of the films, whereas higher iota-carrageenan content produced films with higher elongation, moisture absorption and capsule solubility in acid solution. Capsule with 2% (w/w starch) of carrageenan at kappa-/iota-ratio 3:1 had the lowest moisture absorption, whereas capsule with 3% (w/w starch) of carrageenan at kappa/iota ratio 1:3 had the highest solubility. It is illustrated that sago starch/carrageenan blends can be used as hard capsule material.

Features of blood serum protein spectrum and cytokine spectrum of rats with chronic carrageenan-induced intestinal inflammation

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A. S. Tkachenko

2014-04-01

Full Text Available It has been established that features of modern diet might be considered as a possible source of inflammatory diseases of gastrointestinal tract. Particular attention is paid to the role of different food additives in the development of intestinal inflammation, including the food additive E407, known as carrageenan. A model of chronic carrageenan-induced gastroenterocolitis of moderate severity has been elaborated, which allows us to study carrageenan-induced intestinal inflammation. In particular, the features of blood serum protein spectrum and cytokine spectrum in chronic carrageenan-induced intestinal inflammation are not studied. The female Wistar rats have been used for the experiment. Chronic carrageenan-induced gastroenterocolitis has been reproduced by the free access of animals to 1% solution of carrageenan in drinking water. Laboratory animals have been divided into 3 groups. Group № 1 consisted of experimental animals, who consumed food additive carrageenan during 2 weeks and group № 2 included experimental animals, who consumed food additive carrageenan during 4 weeks. Group № 3 consisted of intact healthy animals. The development of gastroenterocolitis has been proved morphologically and biochemically. Manipulations with animals have been carried out in accordance with the provisions of the European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes (Strasbourg, 1986. It has been established that the disease has been associated with dysproteinemia. The level of α1-globulins increased after 2 weeks of carrageenan consumption and has been normalized in animals, who consumed carrageenan during 4 weeks. The similar changes have been observed for α2-globulins level. It could be explained by production of acute phase proteins, such as α1-acid glycoprotein, C-reactive protein, fibrinogen, α2-macroglobulin, ceruloplasmin, etc. The intake of carrageenan also caused

NMR study on the network structure of a mixed gel of kappa and iota carrageenans.

Science.gov (United States)

Hu, Bingjie; Du, Lei; Matsukawa, Shingo

2016-10-05

The temperature dependencies of the (1)H T2 and diffusion coefficient (D) of a mixed solution of kappa-carrageenan and iota-carrageenan were measured by NMR. Rheological and NMR measurements suggested an exponential formation of rigid aggregates of kappa-carrageenan and a gradual formation of fine aggregates of iota-carrageenan during two step increases of G'. The results also suggested that longer carrageenan chains are preferentially involved in aggregation, thus resulting in a decrease in the average Mw of solute carrageenans. The results of diffusion measurements for poly(ethylene oxide) (PEO) suggested that kappa-carrageenan formed thick aggregates that decreased hindrance to PEO diffusion by decreasing the solute kappa-carrageenan concentration in the voids of the aggregated chains, and that iota-carrageenan formed fine aggregates that decreased the solute iota-carrageenan concentration less. DPEO in a mixed solution of kappa-carrageenan and iota-carrageenan suggested two possibilities for the microscopic network structure: an interpenetrating network structure, or micro-phase separation. Copyright © 2016. Published by Elsevier Ltd.

Carrageenans as a new source of drugs with metal binding properties.

Science.gov (United States)

Khotimchenko, Yuri S; Khozhaenko, Elena V; Khotimchenko, Maxim Y; Kolenchenko, Elena A; Kovalev, Valeri V

2010-04-01

Carrageenans are abundant and safe non-starch polysaccharides exerting their biological effects in living organisms. Apart from their known pro-inflammation properties and some pharmacological activity, carrageenans can also strongly bind and hold metal ions. This property can be used for creation of the new drugs for elimination of metals from the body or targeted delivery of these metal ions for healing purposes. Metal binding activity of different carrageenans in aqueous solutions containing Y(3+) or Pb(2+) ions was studied in a batch sorption system. The metal uptake by carrageenans is not affected by the change of the pH within the range from 2.0 to 6.0. The rates and binding capacities of carrageenans regarding metal ions were evaluated. The Langmuir, Freundlich and BET sorption models were applied to describe the isotherms and constants, and the sorption isothermal data could be explained well by the Langmuir equation. The results obtained through the study suggest that kappa-, iota-, and lambda-carrageenans are favorable sorbents. The largest amount of Y(3+) and Pb(2+) ions are bound by iota-carrageenan. Therefore, it can be concluded that this type of polysaccharide is the more appropriate substance for elaboration of the drugs with high selective metal binding properties.

Carrageenans as a New Source of Drugs with Metal Binding Properties

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Yuri S. Khotimchenko

2010-04-01

Full Text Available Carrageenans are abundant and safe non-starch polysaccharides exerting their biological effects in living organisms. Apart from their known pro-inflammation properties and some pharmacological activity, carrageenans can also strongly bind and hold metal ions. This property can be used for creation of the new drugs for elimination of metals from the body or targeted delivery of these metal ions for healing purposes. Metal binding activity of different carrageenans in aqueous solutions containing Y3+ or Pb2+ ions was studied in a batch sorption system. The metal uptake by carrageenans is not affected by the change of the pH within the range from 2.0 to 6.0. The rates and binding capacities of carrageenans regarding metal ions were evaluated. The Langmuir, Freundlich and BET sorption models were applied to describe the isotherms and constants, and the sorption isothermal data could be explained well by the Langmuir equation. The results obtained through the study suggest that κ-, ι-, and λ-carrageenans are favorable sorbents. The largest amount of Y3+ and Pb2+ ions are bound by i-carrageenan. Therefore, it can be concluded that this type of polysaccharide is the more appropriate substance for elaboration of the drugs with high selective metal binding properties.

Characterisation and Radiation Modification of Carrageenan in the Solid State

International Nuclear Information System (INIS)

Gulrez, S.; Al-Assaf, S.; Phillips, G.O.

2010-01-01

This study reports the modification of kappa-carrageenan in the solid state using gamma radiation (in the dose range of 1-25kGy) in the presence of unsaturated alkyne gas. The results showed maximum production of hydrogel at 5kGy with nearly 80% of starting material being converted to hydrogel form in the absence of a gellin agent. Higher irradiation doses at 25kGy resulted in reducing the hydrogel proportion to ~40% due to degradation. The molecular weight and distribution was determined by GPC-MALLS and the results showed a decrease in the mass recovery and molecular weight of the soluble fraction at 60C. The molecular weight results were in agreement with hydrogel data determined from the filtration method. There was an optimum increase in the viscosity, elasticity and mechanical strength at 5kGy which was followed by a decrease in the gel strength at higher doses (25kGy). Our study demonstrates the potential production of novel hydrogel based carrageenan obtained by irradiation in the absence of metal ions with possible new applications. A mechanism for the radiation induced cross-linking to produce superhelical aggregates in the absence of a gelling agent is proposed. (author)

SANS contrast in iota-carrageenan gels and solutions in D2O

DEFF Research Database (Denmark)

Mischenko, N.; Denef, B.; Mortensen, K.

1997-01-01

SANS of Na+-iota-carrageenan in D2O/saline solutions was measured as a function of concentration, temperature and type of counterions (K+ or Na+). High and low scattering-contrasted gels and solutions were detected. High contrast is caused by aggregation of low-hydrated chains at high concentration...

Study Of Calcium And Potassium Different Nature Strength Gel Kappa-Carrageenan

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Петро Васильович Гурський

2015-07-01

Full Text Available The influence of certain organic and mineral salts of potassium and calcium for strength gel kappa-carrageenan. The influence of the mass concentration of individual calcium for strength gels with different content kappa-carrageenan. Grounded mass concentration of some calcium salts for use in the composition of the jelly for sweet and savory dishes based on kappa-carrageenan

Europium ion as a probe for binding sites to carrageenans

International Nuclear Information System (INIS)

Ramos, Ana P.; Goncalves, Rogeria R.; Serra, Osvaldo A.; Zaniquelli, Maria Elisabete D.; Wong, Kenneth

2007-01-01

Carrageenans, sulfated polysaccharides extracted from red algae, present a coil-helix transition and helix aggregation dependence on the type and concentration of counterions. In this study, we focus attention on a mixed valence counterion system: Eu 3+ /Na + or K + with different gel-forming carrageenans: kappa, iota, and kappa-2. Results of stationary and time-dependent luminescence showed to be a suitable tool to probe ion binding to both the negatively charged sulfate group and the hydroxyl groups present in the biopolymer. For lower europium ion concentrations, a single longer decay emission lifetime was detected, which was attributed to the binding of europium ion to the carrageenan sulfate groups. An additional decay ascribed to europium binding to hydroxyl groups was observed above a threshold concentration, and this decay was dependent on the carrageenan charge density. Symmetry of the europium ion microenvironment was estimated by the ratio between the intensities of its emission bands, which has been shown to depend on the concentration of europium ions and on the specificity of the monovalent counterion bound to the carrageenan

Carrageenan Extracted from Eucheuma cottonii Through Variant of Drying Time

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Pralisa Putri Novy

2018-01-01

Full Text Available Carrageenan is a derivative product of seaweed that used in various fields such as pharmacy, food and cosmetics. One of the most widely used carrageenan from seaweed was Eucheuma cottonii sp. The research was conduct to determine the effect of post-harvest seaweed pre-treatment on yields of Carrageenan. The first pre-treatment done by using the fresh seaweed that has been washed clean then directly dried. The second pre-treatment, washed seaweed soaked with clean water for seven days and then dried with a dryer. Drying time for the first and second pre-treatments is varied, then dried seaweed extracted with water to produce carrageenan. The analyses performed were moisture content of seaweed and yields of Carrageenan. The results of the research found that the initial moisture content of seaweed on the second pre-treatment was greater than the first pre-treatment. The variation of drying time on the first pre-treatment did not affect significantly on the yields, but in the second pre-treatment, yield of carageenan increased with accumulation drying time.

Europium ion as a probe for binding sites to carrageenans

Energy Technology Data Exchange (ETDEWEB)

Ramos, Ana P.; Goncalves, Rogeria R.; Serra, Osvaldo A. [Departamento de Quimica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo 14040-901 (Brazil); Zaniquelli, Maria Elisabete D. [Departamento de Quimica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo 14040-901 (Brazil)], E-mail: medzaniquelli@ffclrp.usp.br; Wong, Kenneth [Laboratorio de Fisico-Quimica, Centro de Pesquisas de Paulinia, Rhodia Brasil, Paulinia, Sao Paulo (Brazil)

2007-12-15

Carrageenans, sulfated polysaccharides extracted from red algae, present a coil-helix transition and helix aggregation dependence on the type and concentration of counterions. In this study, we focus attention on a mixed valence counterion system: Eu{sup 3+}/Na{sup +} or K{sup +} with different gel-forming carrageenans: kappa, iota, and kappa-2. Results of stationary and time-dependent luminescence showed to be a suitable tool to probe ion binding to both the negatively charged sulfate group and the hydroxyl groups present in the biopolymer. For lower europium ion concentrations, a single longer decay emission lifetime was detected, which was attributed to the binding of europium ion to the carrageenan sulfate groups. An additional decay ascribed to europium binding to hydroxyl groups was observed above a threshold concentration, and this decay was dependent on the carrageenan charge density. Symmetry of the europium ion microenvironment was estimated by the ratio between the intensities of its emission bands, which has been shown to depend on the concentration of europium ions and on the specificity of the monovalent counterion bound to the carrageenan.

Characterisation of Prosopis juliflora seed gum and the effect of its addition to κ-carrageenan systems

International Nuclear Information System (INIS)

Azero, Edwin G.; Andrade, Cristina T.

2006-01-01

The galactomannan from Prosopis juliflora (PJ galactomannan) was extracted from milled seeds in water at 50 deg C. Its structural and solution properties were characterised in comparison with a commercial sample of guar gum (GG galactomannan). After partial degradation, the resulting samples were submitted to 13 C-NMR spectroscopy. The mannose to galactose (M/G) ratios of PJ (M/G = 1.64) and GG (M/G = 1.85) galactomannans were estimated from the relative peak areas of the corresponding C-1 lines. Expansion of the C-4 lines revealed differences in the fine structure of the two galactomannans. The intrinsic viscosity determined for the GG sample, [η] = 10.3 dL g -1 , was slightly higher than that determined for PJ galactomannan, [η] = 9.4 dL g -1 . Dynamic experiments carried out at the same concentrations showed similar viscoelastic behaviours for the two gums. No enhancement in the storage modulus (G') was observed for κ-carrageenan/PJ mixed solution in 0.1 mol L -1 KCl at 1.0 g L -1 total polymer concentration, in relation to κ-carrageenan alone. Self-supporting gels obtained by mixing κ-carrageenan and PJ or GG galactomannans in 0.25 mol L -1 KCl at 10 g L -1 total polymer concentration displayed similar mechanical properties. (author)

Application of iota and kappa carrageenans to traditional several food using modified cassava flour

Science.gov (United States)

Al-Baarri, A. N.; Legowo, A. M.; Rizqiati, H.; Widayat; Septianingrum, A.; Sabrina, H. N.; Arganis, L. M.; Saraswati, R. O.; Mochtar, Rr C. P. R.

2018-01-01

Carrageenan has been known well as hydrocolloids that forming viscous dispersions and gels when dispersed in water. The carrageenan has not been widely applied to traditional foods. Therefore, the aim of this research was to determine the effect of kappa and iota carrageenans in traditional food models using modified cassava flour, sugar, and coconut milk. The textural properties, i.e. hardness, cohesiveness, springiness and adhesiveness have been measured using texture analyzer. The study indicated that traditional food models added kappa carrageenan at 2% generated remarkably higher in the hardness, cohesiveness, and springiness than those added iota carrageenan. On the other hand, the reserve result were found in the adhesiveness parameter. As conclusion, kappa carrageenan scan be potentially used for producing traditional foods based on the hard-texture-oriented foods whereas iota carrageenan can be used for the traditional foods with better adhesiveness.

Cationization of kappa- and iota-carrageenan--Characterization and properties of amphoteric polysaccharides.

Science.gov (United States)

Barahona, Tamara; Prado, Héctor J; Bonelli, Pablo R; Cukierman, Ana L; Fissore, Eliana L; Gerschenson, Lia N; Matulewicz, María C

2015-08-01

Commercial kappa- and iota carrageenans were cationized with 3-chloro-2-hydroxypropyltrimethylammonium chloride in aqueous sodium hydroxide solution. For kappa-carrageenan three derivatives with different degrees of substitution were obtained. Native and amphoteric kappa-carrageenans were characterized by NMR and infrared spectroscopy, scanning electron and atomic force microscopy; methanolysis products were studied by electrospray ionization mass spectrometry. Young moduli and the strain at break of films, differential scanning calorimetry, rheological and flocculation behavior were also evaluated; the native and the amphoteric derivatives showed different and interesting properties. Cationization of iota-carrageenan was more difficult, indicating as it was previously observed for agarose, that substitution starts preferentially on the 2-position of 3,6-anhydrogalactose residues; in iota-carrageenan this latter unit is sulfated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Anti-inflammatory activity of Ruta graveolens Linn on carrageenan ...

African Journals Online (AJOL)

Aqueous, ethanolic and methanolic extracts of Ruta graveolens were investigated for anti-inflammatory activity in carrageenan induced paw edema in wistar male rats, and compared to a positive control drug, Voveran. These extracts were given (ip) in a concentration of 20 and 50 mg/kg b.w. before carrageenan injection.

Potential of carrageenans to protect drugs from polymorphic transformation.

Science.gov (United States)

Schmidt, Andrea G; Wartewig, Siegfried; Picker, Katharina M

2003-07-01

Carrageenans were analysed in mixture with polymorphic drugs to test their potential for minimising polymorphic or pseudopolymorphic transitions, which are induced by the tableting process. The kappa-carrageenans Gelcarin GP-812 NF and Gelcarin GP-911 NF and the iota-carrageenan Gelcarin GP-379 NF were tested in comparison to the well-known tableting excipients microcrystalline cellulose (MCC), hydroxypropyl methylcellulose (HPMC), and dicalcium phosphate dihydrate (DCPD). Amorphous indomethacin was chosen as model drug since its well-known recrystallisation behaviour can be mechanically stimulated. Further on, theophylline monohydrate was used. Its dehydration is induced by tableting. Pure materials and mixtures containing 20% (w/w) drug were compressed up to different maximum relative densities. The data obtained during tableting were analysed by three-dimensional (3D) modelling. Afterwards tablets were broken and examined by Fourier transform Raman spectroscopy in order to determine the degree of transformation inside the tablet. For quantitative interpretation, the intensities of representative bands were used. Thermal analysis was used additionally. Using 3D modelling a decrease of plastic deformation can be noticed in the order HPMC>MCC>carrageenans, whereas DCPD represents an exception because of brittle fracture. Best hindrance of polymorphic transformation showed the carrageenans, the hindrance was slightly worse for HPMC. MCC and DCPD could not hinder transformation. A complete protection of the amorphous form could not be achieved. For theophylline monohydrate, the results were similar.

Comparison of the effects of crocin, safranal and diclofenac on local inflammation and inflammatory pain responses induced by carrageenan in rats.

Science.gov (United States)

Tamaddonfard, Esmaeal; Farshid, Amir-Abbas; Eghdami, Karim; Samadi, Farzad; Erfanparast, Amir

2013-01-01

Crocin and safranal are the active substances of saffron and have many biological properties. In the present study, we compared the effects of crocin, safranal and diclofenac on local inflammation and its induced pain in rats. Local inflammation was induced by intraplantar (ipl) injection of carrageenan (100 μl, 2%). Paw thickness was measured before and after carrageenan injection. Inflammatory pain responses including cold allodynia, mechanical allodynia and hyperalgesia were assessed using acetone spray and von Frey filament tests, respectively. The number of neutrophils in inflammatory zone was counted 6.5 h after injection of carrageenan. Carrageenan produced edema, cold allodynia, mechanical allodynia and hyperalgesia and caused neutrophil infiltration in paw tissues. Crocin at doses of 25, 50 and 100 mg/kg, safranal at doses of 0.5, 1 and 2 mg/kg and diclofenac (as a reference drug) at a dose of 10 mg/kg attenuated edema, suppressed inflammatory pain responses and decreased the number of neutrophils. The present study showed anti-inflammatory and antinociceptive activities for crocin, safranal and diclofenac in carrageenan model of local inflammation and inflammatory pain.

Seasonal changes in Carrageenan and other biochemical constituents of Hypnea musciformis

Digital Repository Service at National Institute of Oceanography (India)

Solimabi; Dass, B.; Kamat, S.Y.; DeSouza, L.; Reddy, C.V.G.

Carrageenan content was maximum in winter. Near inverse relationship was observed between the total carbohydrate and carrageenan. Protein levels were highest when the nitrogenous nutrients were high...

λ-Carrageenan Suppresses Tomato Chlorotic Dwarf Viroid (TCDVd Replication and Symptom Expression in Tomatoes

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Jatinder S. Sangha

2015-05-01

Full Text Available The effect of carrageenans on tomato chlorotic dwarf viroid (TCDVd replication and symptom expression was studied. Three-week-old tomato plants were spray-treated with iota(ɩ-, lambda(λ-, and kappa(κ-carrageenan at 1 g·L−1 and inoculated with TCDVd after 48 h. The λ-carrageenan significantly suppressed viroid symptom expression after eight weeks of inoculation, only 28% plants showed distinctive bunchy-top symptoms as compared to the 82% in the control group. Viroid concentration was reduced in the infected shoot cuttings incubated in λ-carrageenan amended growth medium. Proteome analysis revealed that 16 tomato proteins were differentially expressed in the λ-carrageenan treated plants. Jasmonic acid related genes, allene oxide synthase (AOS and lipoxygenase (LOX, were up-regulated in λ-carrageenan treatment during viroid infection. Taken together, our results suggest that λ-carrageenan induced tomato defense against TCDVd, which was partly jasmonic acid (JA dependent, and that it could be explored in plant protection against viroid infection.

Carrageenan drying with dehumidified air: drying characteristics and product quality

NARCIS (Netherlands)

Djaeni, M.; Sasongko, S.B.; Prasetyaningrum, Aji A A.A.; Jin, X.; Boxtel, van A.J.B.

2012-01-01

Applying dehumidified air is considered as an option to retain quality in carrageenan drying. This work concerns the effects of operational temperature, air velocity, and carrageenan thickness on the progress of drying and product quality when using dehumidified air. Final product quality and

Characterisation of Prosopis juliflora seed gum and the effect of its addition to {kappa}-carrageenan systems

Energy Technology Data Exchange (ETDEWEB)

Azero, Edwin G. [Universidade Federal do Estado do Rio de Janeiro (UNIRIO), Rio de Janeiro, RJ (Brazil). Dept. de Ciencias Naturais; Andrade, Cristina T. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano]. E-mail: ctandrade@ima.ufrj.br

2006-09-15

The galactomannan from Prosopis juliflora (PJ galactomannan) was extracted from milled seeds in water at 50 deg C. Its structural and solution properties were characterised in comparison with a commercial sample of guar gum (GG galactomannan). After partial degradation, the resulting samples were submitted to {sup 13}C-NMR spectroscopy. The mannose to galactose (M/G) ratios of PJ (M/G = 1.64) and GG (M/G = 1.85) galactomannans were estimated from the relative peak areas of the corresponding C-1 lines. Expansion of the C-4 lines revealed differences in the fine structure of the two galactomannans. The intrinsic viscosity determined for the GG sample, [{eta}] = 10.3 dL g{sup -1}, was slightly higher than that determined for PJ galactomannan, [{eta}] = 9.4 dL g{sup -1}. Dynamic experiments carried out at the same concentrations showed similar viscoelastic behaviours for the two gums. No enhancement in the storage modulus (G') was observed for {kappa}-carrageenan/PJ mixed solution in 0.1 mol L{sup -1} KCl at 1.0 g L{sup -1} total polymer concentration, in relation to {kappa}-carrageenan alone. Self-supporting gels obtained by mixing {kappa}-carrageenan and PJ or GG galactomannans in 0.25 mol L{sup -1} KCl at 10 g L{sup -1} total polymer concentration displayed similar mechanical properties. (author)

In vitro safety evaluation of human nasal epithelial cell monolayers exposed to carrageenan sinus wash.

Science.gov (United States)

Ramezanpour, Mahnaz; Murphy, Jae; Smith, Jason L P; Vreugde, Sarah; Psaltis, Alkis James

2017-12-01

Carrageenans have shown to reduce the viral load in nasal secretions and lower the incidence of secondary infections in children with common cold. Despite the widespread use of carrageenans in topical applications, the effect of carrageenans on the sinonasal epithelial barrier has not been elucidated. We investigate the effect of different carrageenans on the sinonasal epithelial barrier and inflammatory response in vitro. Iota and Kappa carrageenan delivered in saline irrigation solutions applied to air-liquid interface (ALI) cultures of primary human nasal epithelial cells from chronic rhinosinusitis patients and controls. Epithelial barrier structure was assessed by measuring the transepithelial electrical resistance (TEER) and immunolocalization of F actin. Ciliary beat frequency (CBF), toxicity, and inflammatory response was studied. Kappa or Iota carrageenan in the different solutions was not toxic, did not have detrimental effects on epithelial barrier structure and CBF. Rather, application of Kappa carrageenan significantly increased TEER and suppressed interleukin 6 (IL-6) secretion in ALI cultures from CRS patients. Kappa or Iota carrageenan solution was safe and did not negatively affect epithelial barrier function. Kappa carrageenan increased TEER and decreased IL-6 production in CRS patients, indicating positive effects on epithelial barrier function in vitro. © 2017 ARS-AAOA, LLC.

The effect of combination of sugar palm fruit, carrageenan, and citric acid on mechanical properties of biodegradable film

Science.gov (United States)

Rinanda, S. A.; Nastabiq, M.; Raharjo, S. H.; Hayati, S. K.; Yaqin, M. A.; Ratnawati

2017-11-01

Biodegradable film is a type of plastic material that can be degraded naturally and is usually made of organic material. The material commonly used is polysaccharides. The purpose of this study is to observe the effect of the combination of sugar palm fruit, carrageenan, and citric acid (CA) on the mechanical properties of the biodegradable films, such as tensile strength, elongation and film thickness. The experiment begins with dissolving the sugar palm fruit porridge and carrageenan with ratios of 1:0, 3:1, 2:1, 1:1 in water. The mixture was heated using a heater and magnetic stirrer at 80° C for 10 minutes. Glycerol and citric acid (CA) were added to the solution and stirred for 5 minutes. Each film solution was printed on a modified acrylic and, dried for 18 hours in an oven at 55° C. The formed film layer was then removed from the acrylic mold and inserted in a desiccatorsat 23° C for 1 hour. Then the film analyzed for its tensile strength, elongation using Dynamic Mechanical Thermal Analysis (DMTA), and thickness. The optimum result shown by sugar palm fruit and carrageenan ratio of 1:1 with 1% citric acid (CA).

Optical transparency and mechanical properties of semi-refined iota carrageenan film reinforced with SiO2 as food packaging material

Science.gov (United States)

Aji, Afifah Iswara; Praseptiangga, Danar; Rochima, Emma; Joni, I. Made; Panatarani, Camellia

2018-02-01

Food packaging is important for protecting food from environmental influences such as heat, light, water vapor, oxygen, dirt, dust particles, gas emissions and so on, which leads to decrease the quality of food. The most widely used type of packaging in the food industry is plastic which is made from synthetic polymers and takes hundreds of years to biodegrade. Recently, food packaging with high bio-degradability is being developed using biopolymer combined with nanoparticles as reinforcing agent (filler) to improve its properties. In this study, semi-refined iota carrageenan films were prepared by incorporating SiO2 nanoparticles as filler at different concentrations (0%, 0.5%, 1.0% and 1.5% w/w carrageenan) using solution casting method. The optical transparency and mechanical properties (tensile strength and elongation at break) of the films were analyzed. The results showed that incorporation of SiO2 nanoparticles to carrageenan matrix on optical transparency of the films. For the mechanical properties, the highest tensile strength was found for incorporation of 0.5% SiO2, while the elongation at break of the films improved with increasing SiO2 concentration.

Anti-ulcer, anti-protozoan and anti-cancer activities of irradiated κ-carrageenan: some biological effects of irradiated food grade-carrageenan on various gastrointestinal disorders

International Nuclear Information System (INIS)

Deocaris, Custer C.; Cruz, Angela C; Dela Rosa, Alumanda M.; De Guzman, Roche Ray C.; Abilo, Rhea Mae L.; Gutierrez, Ana Kamila O.; Deocaris, Chester C.

2001-01-01

κ carrageenan and its radiolytic products are both shown to strongly inhibit pepsin activity based on our in vitro peptic ulcer model. Generated Lineweaver-Burke (LB) plots resemble the trend for competitive inhibition except that the changes in the slopes are too large rendering Km to approach a negative value. Our observations corroborate with the published dual behavior of carrageenan in inhibiting peptic ulcers, that is, by exerting simultaneously both enzyme (E) competitive inhibition and substrate (S) occlusion. Irradiated-carrageenan does not display anti-protozoan activity against Tetrahymena and pathogenic Entamoeba histolytica, and anti-tumor potential based on Artemia salina (brine shrimp) nauplus tests and the MTT assay with human MCF7 breast carcinoma cell line. (Author)

The Effects of plasticizers and palmitic acid toward the properties of the carrageenan Film

Science.gov (United States)

Heru Wibowo, Atmanto; Listiyawati, Oktaviana; Purnawan, Candra

2016-02-01

Varied plasticizers and palmitic acid additive have been added in the carrageenan film. The film was made by mixing of the carrageenan and plasticizers (glycerol, polyethylene glycol, polyvinyl alcohol) with composition of 92:3, 90:6, 87:9, 84:12, 81:15(%w/w) and in the presence of palmitic acid as additive with 1%, 2%, 3%, 4%, 5% of total weight. Casting method was used for the film molding and drying at 60oC with the oven for 12 hours. To investigate the effects of plasticizers and additive, some mechanical tests on film were performed. The test result concludes that plasticizers in the film decreased the tensile strength and increased the elongation break of the carrageenan film. The additive of palmitic acid decreased the tensile strength of the carrageenan film and also decreased the-the water absorbance of the film. The highest tensile strength of films made was with the formulation of carrageenan: PEG with composition of 92:3 (% w/w). The highest elongation break of the film was for carrageenan:PVA with the composition of 81: 15 (%w/w) and carrageenan:palmitic acid:PEG with the composition of 92: 3: 1 (%w/w). The lowest water absorption of the film was achieved for carrageenan:PVA:palmitic acid with the composition of 87: 3: 5 (%w/w).

Three-Dimensional Supermacroporous Carrageenan-Gelatin Cryogel Matrix for Tissue Engineering Applications

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Archana Sharma

2013-01-01

Full Text Available A tissue-engineered polymeric scaffold should provide suitable macroporous structure similar to that of extracellular matrix which can induce cellular activities and guide tissue regeneration. Cryogelation is a technique in which appropriate monomers or polymeric precursors frozen at sub-zero temperature leads to the formation of supermacroporous cryogel matrices. In this study carrageenan-gelatin (natural polymers cryogels were synthesized by using glutaraldehyde and 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride and N-hydroxysuccinimide (EDC-NHS as crosslinking agent at optimum concentrations. Matrices showed large and interconnected pores which were in the range of 60–100 μm diameter. Unconfined compression analysis showed elasticity and physical integrity of all cryogels, as these matrices regained their original length after 90% compressing from the original size. Moreover Young’s modulus was found to be in the range of 4–11 kPa for the dry cryogel sections. These cryogels also exhibited good in vitro degradation capacity at 37 °C within 4 weeks of incubation. Supermacroporous carrageenan-gelatin cryogels showed efficient cell adherence and proliferation of Cos-7 cells which was examined by SEM. PI nuclear stain was used to observe cell-matrix interaction. Cytotoxicity of the scaffolds was checked by MTT assay which showed that cryogels are biocompatible and act as a potential material for tissue engineering and regenerative medicine.

Kinetics and Thermodynamics of Ultrasound-Assisted Depolymerization of κ-Carrageenan

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Ratnawati Ratnawati

2016-03-01

Full Text Available The ultrasound-assisted depolymerization of κ-carrageenan has been studied at various temperatures and times. The κ-carrageenan with initial molecular weight of 545 kDa was dispersed in water to form a 5 g/L solution, which was then depolymerized in an ultrasound device at various temperatures and times. The viscosity of the solution was measured using Brookfield viscometer, which was then used to find the number-average molecular weight by Mark-Houwink equation. To obtain the kinetics of κ-carrageenan depolymerization, the number-average molecular weight data was treated using midpoint-chain scission kinetics model. The pre-exponential factor and activation energies for the reaction are 2.683×10-7 mol g-1 min-1 and 6.43 kJ mol-1, respectively. The limiting molecular weight varies from 160 kDa to 240 kDa, and it is linearly correlated to temperature. The results are compared to the result of thermal depolymerization by calculating the half life. It is revealed that ultrasound assisted depolymerization of κ-carrageenan is faster than thermal depolymerization at temperatures below 72.2°C. Compared to thermal depolymerization, the ultrasound-assisted process has lower values of Ea, ΔG‡, ΔH‡, and ΔS‡, which can be attributed to the ultrasonically induced breakage of non-covalent bonds in κ-carrageenan molecules. Copyright © 2016 BCREC GROUP. All rights reserved Received: 10th November 2015; Revised: 18th January 2016; Accepted: 19th January 2016 How to Cite: Ratnawati, R., Prasetyaningrum, A., Wardhani, D.H. (2016. Kinetics and Thermodynamics of Ultrasound-Assisted Depolymerization of κ-Carrageenan. Bulletin of Chemical Reaction Engineering & Catalysis, 11(1: 48-58. (doi:10.9767/bcrec.11.1.415.48-58 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.1.415.48-58

Heparin-Functionalized chitosan/ κ-carrageenan complexes as potential scaffolds for tissue engineering

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Dofeliz, Joni L.; Rojas, Nina Rosario L.

2015-01-01

Cell-based approaches to tissue regeneration are playing an increasingly important role in bone and cartilage repair. This is made possible through the use of growth factors, which are signaling molecules that induce a number of effects such as cell proliferation, migration and differentiation. But problems arise as these growth factors tend to be expensive, short-lived and slow moving through the extracellular matrix, making them very inefficient in their current form of introduction. One such growth factor is basic fibroblast growth factor (bFGF). The general objective of this study is to construct heparin-functionalized chitosan/κ-carrageenan scaffolds, which when bound to basic fibroblast growth factor (bFGF), may be used in the culture of mesenchymal stem cells for differentiation into cartilage. In this study, gels of semi-interpenetrating networks (semi-IPN) of chitosan and κ-carrageenan (2:4:1 blend ration) were prepared using calcium chloride as a cross-linker. The gels were then functionalized with heparin, which is known for its growth factor binding ability, using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) as cross-linker. The functionalized gels were then reshaped into scaffold on the wells of 48-well plates through freeze-dry method. The scaffolds were found to be realatively porous with pore sizes larger than 100 μm which satisfies the requirements for cell culture. Subsequent thermogravimetric analysis shows that the scaffolds were relatively stable with a degradation temperature of 277°C. Additionally, there was no observable separation of the individual degradation temperatures of chitosan and κ-carrageenan, confirming that a single miscible phase in the form of a semi-IPN structure was created. Results of scanning electron microscopy also showed that the scaffolds were stable under 2 hours of UV sterilization. The FTIR spectra of the heparinized PEC showed characteristic absorption bands (S=O asymetric stretch) in the area of 1160

Evaluation of polyethylenimine/carrageenan multi-layer for antibacterial activity of pathogenic bacteria

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Briones, Annabelle V.; Bigol, Urcila G.; Sato, Toshinori

2012-01-01

The purpose of this study is to investigate the antibacterial activity of multi-layer of polyethylenimine (PEI) and carrageenan (κ,ι, λ) for potential use as coating on biomaterial surface. The multi-layer of PEI/carrageenan was formed using the layer-by-layer assembly absorption technique and was monitored by atomic force microscopy (AFM) and bio molecular interaction analysis. All samples were prepared in phosphate buffer solution and applied to mica disk alternately. The micrographs showed the formation of bi-layer of polyethylenimine and carrageenan (κ, ι, λ) as observed in the change of height of the layer and surface morphology. The bimolecular binding of carrageenan with polyethylenimine was also investigated using a biosensor. The sensorgram showed that PEI interacted molecularly with carrageenan. Results were: 1,916.08 pg/nm 2 for kappa type; 1,844.1 pg/nm 2 for iota type and 6,074.24 pg/nm 2 for lambda type. The multi-layer showed antibacterial activity against Enterobacter cloaceae, Staphylococcus aureus and Enterococcal strains (Enterococcus faecalis (EF) 29212 and 29505). (author)

Iota-carrageenan is a potent inhibitor of influenza A virus infection.

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Andreas Leibbrandt

Full Text Available The 2009 flu pandemic and the appearance of oseltamivir-resistant H1N1 influenza strains highlight the need for treatment alternatives. One such option is the creation of a protective physical barrier in the nasal cavity. In vitro tests demonstrated that iota-carrageenan is a potent inhibitor of influenza A virus infection, most importantly also of pandemic H1N1/2009 in vitro. Consequently, we tested a commercially available nasal spray containing iota-carrageenan in an influenza A mouse infection model. Treatment of mice infected with a lethal dose of influenza A PR8/34 H1N1 virus with iota-carrageenan starting up to 48 hours post infection resulted in a strong protection of mice similar to mice treated with oseltamivir. Since alternative treatment options for influenza are rare, we conclude that the nasal spray containing iota-carrageenan is an alternative to neuraminidase inhibitors and should be tested for prevention and treatment of influenza A in clinical trials in humans.

Diethylcarbamazine Attenuates the Development of Carrageenan-Induced Lung Injury in Mice

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Edlene Lima Ribeiro

2014-01-01

Full Text Available Diethylcarbamazine (DEC is an antifilarial drug with potent anti-inflammatory properties as a result of its interference with the metabolism of arachidonic acid. The aim of the present study was to evaluate the anti-inflammatory activity of DEC in a mouse model of acute inflammation (carrageenan-induced pleurisy. The injection of carrageenan into the pleural cavity induced the accumulation of fluid containing a large number of polymorphonuclear cells (PMNs as well as infiltration of PMNs in lung tissues and increased production of nitrite and tumor necrosis factor-α and increased expression of interleukin-1β, cyclooxygenase (COX-2, and inducible nitric oxide synthase. Carrageenan also induced the expression of nuclear factor-κB. The oral administration of DEC (50 mg/Kg three days prior to the carrageenan challenge led to a significant reduction in all inflammation markers. The present findings demonstrate that DEC is a potential drug for the treatment of acute lung inflammation.

Population Studies and Carrageenan Properties in Eight Gigartinales (Rhodophyta from Western Coast of Portugal

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Leonel Pereira

2013-01-01

Full Text Available Eight carrageenophytes, representing seven genera and three families of Gigartinales (Florideophyceae, were studied for 15 months. The reproductive status, dry weight, and carrageenan content have been followed by a monthly random sampling. The highest carrageenan yields were found in Chondracanthus acicularis (61.1%, Gigartina pistillata (59.7%, and Chondracanthus teedei var. lusitanicus (58.0%. Species of Cystocloniaceae family produces predominantly iota-carrageenans; Gigartinaceae family produces hybrid kappa-iota carrageenans (gametophytic plants and lambda-family carrageenans (sporophytic plants; Phyllophoraceae family produces kappa-iota-hybrid carrageenans. Quadrate destructive sampling method was used to determine the biomass and line transect. Quadrate nondestructive sampling method, applied along a perpendicular transect to the shoreline, was used to calculate the carrageenophytes cover in two periods: autumn/winter and spring/summer. The highest cover and biomass were found in Chondrus crispus (3.75%–570 g/m2, Chondracanthus acicularis (3.45%–99 g/m2, Chondracanthus teedei var. lusitanicus (2.45%–207.5 g/m2, and Mastocarpus stellatus (2.02%–520 g/m2.

Population studies and carrageenan properties in eight Gigartinales (Rhodophyta) from Western Coast of Portugal.

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Pereira, Leonel

2013-01-01

Eight carrageenophytes, representing seven genera and three families of Gigartinales (Florideophyceae), were studied for 15 months. The reproductive status, dry weight, and carrageenan content have been followed by a monthly random sampling. The highest carrageenan yields were found in Chondracanthus acicularis (61.1%), Gigartina pistillata (59.7%), and Chondracanthus teedei var. lusitanicus (58.0%). Species of Cystocloniaceae family produces predominantly iota-carrageenans; Gigartinaceae family produces hybrid kappa-iota carrageenans (gametophytic plants) and lambda-family carrageenans (sporophytic plants); Phyllophoraceae family produces kappa-iota-hybrid carrageenans. Quadrate destructive sampling method was used to determine the biomass and line transect. Quadrate nondestructive sampling method, applied along a perpendicular transect to the shoreline, was used to calculate the carrageenophytes cover in two periods: autumn/winter and spring/summer. The highest cover and biomass were found in Chondrus crispus (3.75%-570 g/m(2)), Chondracanthus acicularis (3.45%-99 g/m(2)), Chondracanthus teedei var. lusitanicus (2.45%-207.5 g/m(2)), and Mastocarpus stellatus (2.02%-520 g/m(2)).

Calibration of the BASS acoustic current meter with carrageenan agar

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Morrison, A.T.; Williams, A.J.; Martini, M.

1993-01-01

The BASS current meter can measure currents down to the millimeter per second range. Due to the dependence of zero offset on pressure, determining a sensor referenced velocity requires accurate in situ zeroing of the meter. Previously, flow was restricted during calibration by placing plastic bags around the acoustic volume. In this paper, bacterial grade and carrageenan agars are used in the laboratory to create a zero flow condition during calibration and are shown to be acoustically transparent. Additionally, the results of open ocean and dockside carrageenan and plastic bag comparisons are presented. Carrageenan is shown to reliably provide a low noise, zero mean flow environment that is largely independent of ambient conditions. The improved zeros make millimeter per second accuracy possible under field conditions.

The Role of Carrageenan and Carboxymethylcellulose in the Development of Intestinal Inflammation

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Johan Van Limbergen

2017-05-01

Full Text Available Although the exact pathophysiology remains unknown, the development of inflammatory bowel disease (IBD is influenced by the interplay between genetics, the immune system, and environmental factors such as diet. The commonly used food additives, carrageenan and carboxymethylcellulose (CMC, are used to develop intestinal inflammation in animal models. These food additives are excluded from current dietary approaches to induce disease remission in Crohn’s disease such as exclusive enteral nutrition (EEN using a polymeric formula. By reviewing the existing scientific literature, this review aims to discuss the role that carrageenan and CMC may play in the development of IBD. Animal studies consistently report that carrageenan and CMC induce histopathological features that are typical of IBD while altering the microbiome, disrupting the intestinal epithelial barrier, inhibiting proteins that provide protection against microorganisms, and stimulating the elaboration of pro-inflammatory cytokines. Similar trials directly assessing the influence of carrageenan and CMC in humans are of course unethical to conduct, but recent studies of human epithelial cells and the human microbiome support the findings from animal studies. Carrageenan and CMC may trigger or magnify an inflammatory response in the human intestine but are unlikely to be identified as the sole environmental factor involved in the development of IBD or in disease recurrence after treatment. However, the widespread use of carrageenan and CMC in foods consumed by the pediatric population in a “Western” diet is on the rise alongside a corresponding increase in IBD incidence, and questions are being raised about the safety of frequent usage of these food additives. Therefore, further research is warranted to elucidate the role of carrageenan and CMC in intestinal inflammation, which may help identify novel nutritional strategies that hinder the development of the disease or prevent

Leaching-resistant carrageenan-based colorimetric oxygen indicator films for intelligent food packaging.

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Vu, Chau Hai Thai; Won, Keehoon

2014-07-23

Visual oxygen indicators can give information on the quality and safety of packaged food in an economic and simple manner by changing color based on the amount of oxygen in the packaging, which is related to food spoilage. In particular, ultraviolet (UV)-activated oxygen indicators have the advantages of in-pack activation and irreversibility; however, these dye-based oxygen indicator films suffer from dye leaching upon contact with water. In this work, we introduce carrageenans, which are natural sulfated polysaccharides, to develop UV-activated colorimetric oxygen indicator films that are resistant to dye leakage. Carrageenan-based indicator films were fabricated using redox dyes [methylene blue (MB), azure A, and thionine], a sacrificial electron donor (glycerol), an UV-absorbing photocatalyst (TiO2), and an encapsulation polymer (carrageenan). They showed even lower dye leakage in water than conventional oxygen indicator films, owing to the electrostatic interaction of anionic carrageenan with cationic dyes. The MB/TiO2/glycerol/carrageenan oxygen indicator film was successfully bleached upon UV irradiation, and it regained color very rapidly in the presence of oxygen compared to the other waterproof oxygen indicator films.

Radiation degradation of carbohydrates and their biological activities for plants

International Nuclear Information System (INIS)

Kume, T.; Nagasawa, N.; Matsuhashi, S.

2000-01-01

Radiation effects on carbohydrates such as chitosan, sodium alginate, carrageenan, cellulose, pectin have been investigated to improve the biological activities. These carbohydrates were easily degraded by irradiation and induced various kinds of biological activities such as anti-bacterial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction. Pectic fragments obtained from degraded pectin induced the phytoalexins such as glyceollins in soybean and pisatin in pea. The irradiated chitosan shows the higher elicitor activity for pisatin than that of pectin. For the plant growth promotion, alginate derived from brown marine algae, chitosan and ligno-cellulosic extracts show a strong activity. Kappa and iota carrageenan derived from red marine algae can promote growth of rice and the highest effect was obtained with kappa irradiated at 100 kGy. Some radiation degraded carbohydrates suppressed the damage of heavy metals on plants. The effects of irradiated carbohydrates on transportation of heavy metals have been investigated by PETIS (Positron Emitting Tracer Imaging System) and autoradiography using 48 V and 62 Zn. (author)

The effect of addition of selected carrageenans on viscoelastic properties of model processed cheese spreads

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Michaela Černíková

2007-01-01

Full Text Available The effect of 0.25% w/w κ-carrageenan and ι‑carrageenan on viscoelastic properties of processed cheese were studied using model samples containing 40% w/w dry matter and 45 and 50% w/w fat in dry matter. Experimental samples of processed cheese were evaluated after 14 days of storage at the temperature of 6 ± 2 °C. Basic parameters of processed cheese samples under study (i.e. their dry matter content and pH were not different (P ≥ 0.05. There were no statistically significant differences in values of storage modulus G´ [Pa], loss modulus G'' [Pa] and tangent of phase shift angle tan δ [-] for the reference frequency of 1 Hz between processed cheese with κ‑carrageenan applied in the form of powder and in the form of aqueous dispersion (P ≥ 0.05. The addition of 0.25% w/w κ‑carrageenan and ι‑carrageenan (in the powder form resulted in an increase in storage (G´ and loss (G'' moduli and a decrease in values of tan δ (P < 0.05. As compared with control (i.e. without added carrageenans, samples of processed cheese became firmer. Iota-carrageenan added in the powder form in concentration of 0.25% w/w showed a more intensive effect on the increase in firmness of processed cheese under study than κ‑carrageenan (P < 0.05.

Optimization of the extraction of carrageenan from Kappaphycus alvarezii using response surface methodology

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Vanessa Webber

2012-12-01

Full Text Available This study aims to optimize an alternative method of extraction of carrageenan without previous alkaline treatment and ethanol precipitation using Response Surface Methodology (RSM. In order to introduce an innovation in the isolation step, atomization drying was used reducing the time for obtaining dry carrageenan powder. The effects of extraction time and temperature on yield, gel strength, and viscosity were evaluated. Furthermore, the extracted material was submitted to structural analysis, by infrared spectroscopy and nuclear magnetic resonance spectroscopy (¹H-NMR, and chemical composition analysis. Results showed that the generated regression models adequately explained the data variation. Carrageenan yield and gel viscosity were influenced only by the extraction temperature. However, gel strength was influenced by both, extraction time and extraction temperature. Optimal extraction conditions were 74 ºC and 4 hours. In these conditions, the carrageenan extract properties determined by the polynomial model were 31.17%, 158.27 g.cm-2, and 29.5 cP for yield, gel strength, and viscosity, respectively, while under the experimental conditions they were 35.8 ± 4.68%, 112.50 ± 4.96 g.cm-2, and 16.01 ± 1.03 cP, respectively. The chemical composition, nuclear magnetic resonance spectroscopy, and infrared spectroscopy analyses showed that the crude carrageenan extracted is composed mainly of κ-carrageenan.

Biodegradable Composite Films based on κ-carrageenan Reinforced by Cellulose Nanocrystal from Kenaf Fibers

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Siti Zarina

2014-11-01

Full Text Available Through alkali treatment, bleaching, and sulfuric acid hydrolysis, cellulose nanocrystals (CNCs were prepared from kenaf fibers and were used as reinforcement materials in biocomposites based on κ-carrageenan. Biocomposites in the form of films were prepared by solution casting of a mixture of κ-carrageenan, glycerol, and various amounts of CNCs (0 to 8 wt%. Fourier transform infrared spectroscopy (FTIR revealed that alkali treatment followed by bleaching totally removed lignin and hemicellulose from the kenaf. Morphological analysis of the fibers, cellulose, and κ-carrageenan of biocomposite films were carried out using field emission scanning electron microscopy (FESEM and transmission electron microscopy (TEM. The effects of filler content on the mechanical and thermal stability of the k-carrageenan biocomposite films were analyzed through tensile strength measurements and thermogravimetric analysis (TGA. At an optimum CNC content of 4%, the κ-carrageenan biocomposite films showed good dispersion, superior mechanical properties, and improved thermal stability.

Follistatin Alleviates Synovitis and Articular Cartilage Degeneration Induced by Carrageenan

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Jun Yamada

2014-01-01

Full Text Available Activins are proinflammatory cytokines which belong to the TGFβ superfamily. Follistatin is an extracellular decoy receptor for activins. Since both activins and follistatin are expressed in articular cartilage, we hypothesized that activin-follistatin signaling participates in the process of joint inflammation and cartilage degeneration. To test this hypothesis, we examined the effects of follistatin in a carrageenan-induced mouse arthritis model. Synovitis induced by intra-articular injection of carrageenan was significantly alleviated by preinjection with follistatin. Macrophage infiltration into the synovial membrane was significantly reduced in the presence of follistatin. In addition, follistatin inhibited proteoglycan erosion induced by carrageenan in articular cartilage. These data indicate that activin-follistatin signaling is involved in joint inflammation and cartilage homeostasis. Our data suggest that follistatin can be a new therapeutic target for inflammation-induced articular cartilage degeneration.

Development and characterization of carrageenan/grapefruit seed extract composite films for active packaging.

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Kanmani, Paulraj; Rhim, Jong-Whan

2014-07-01

Carrageenan-based antimicrobial films were developed by incorporation of grape fruit seed extract (GSE) at different concentration into the polymer using a solvent casing method and their physical, mechanical, and antimicrobial properties were examined. The carrageenan/GSE composite films appeared yellowish tint due to the polyphenolic compounds in the GSE. SEM analysis showed rough surface with sponge like structures on the cross section of the films. FT-IR results indicated at GSE had good compatibility with carrageenan. The amorphous structure of polymer films was not changed by the incorporation of GSE. But, the addition of GSE increased moisture content, water vapor permeability, and surface hydrophilicity of the films. The tensile strength and elastic modulus decreased with increasing content of GSE, however, the elongation at break increased significantly up to 6.6μg/mL of GSE then decreased thereafter. Thermal stability of the films was not influenced by GSE incorporation. The carrageenan/GSE composite films exhibited great antibacterial activity against food borne pathogens. These results suggest that the carrageenan-based composite films have a high potential for being used as an antimicrobial or active food packaging applications. Copyright © 2014 Elsevier B.V. All rights reserved.

Physico-Chemical Characterization of Carrageenan at Different Temperatures, Isolated from Hypnea musciformis from Karachi Coast Pakistan

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Junaid Mahmood, Syed; Bi, Fatima; Taj, Noor; Seema; Farhan, M.; Shahid, M.; Azmat, Rafia; Uddin, Fahim

This study describe the basic tools like viscosity measurements and thermodynamic parameters of the polysaccharide isolated from Hypnea musciformis (red algae) of Karachi Coast (Pakistan) showed characteristics of κ-carrageenan. An IR spectrum showed a fairly sharp band at 1210, 1225 cm-1 corresponding to sulphate ester and is in accordance with the high sulphate content of κ-carrageenan. Viscosity measurements revealed a linear relationship with increase in concentration and decreased with the rise in temperature of aqueous solutions of κ-carrageenan. Thermodynamic parameters were determined by the change in viscosity data as a function of temperature and concentration. The free energy change of activation (Î'Gη) increased regularly as the concentration of aqueous κ-carrageenan increased, as well as rises in temperature. Higher values of free energy change of activation, (Î'Gη) showed the higher association of κ-carrageenan with water at given temperature. The values of entropy change of activation (Î'Sη) of viscous flow also increased with the increase in concentration and temperature of aqueous κ-carrageenan solution. The high negative values of entropy change of activation (Î'Sη) showed that the solution of κ-carrageenan was more ordered in initial state than the activated one.

Multi-step carboxymethylation of kappa-Carrageenan

International Nuclear Information System (INIS)

Aranilla, Charito Tranquilan; Nagasawa, Naotsugu; Bayquen, Aristea V.

2008-01-01

Many polysaccharide derivatives have been prepared by carboxymethylation reactions in order to increase the range of potential applications of these natural polymers in the chemical, food, pharmaceutical and cosmetic industries. Carboxymethylation of kappa-carrageenan was attempted for the first time to synthesize derivatives with various degree of substitution. A multistep carboxymethylation was performed under heterogeneous reaction conditions, in isopropyl alcohol/water slurry medium, with aqueous sodium hydroxide solution for activation, and monochloroacetic acid for etherification. The derivatives obtained had average degree of substitutions from 1.20 to 1.92 as determined by potentiometric back-titration. Chemical and structural characterization were accomplished by Gel Permeation Chromatography, Elemental analysis, FT-IR Spectroscopy, 1 H N and 13 C NMR Spectroscopy. The relative reactivity of the hydroxyl groups in κ-carrageenan dimer unit proceeded in the order O-C2 G4S > O-C6 G4S >O-C2 AG at a ratio of 1:0.6:O.4. (author)

Mechanical and solubility properties of bio-nanocomposite film of semi refined kappa carrageenan/ZnO nanoparticles

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Saputri, Apriliana Eka; Praseptiangga, Danar; Rochima, Emma; Panatarani, Camellia; Joni, I. Made

2018-02-01

The aim of this present work is to develop semi refined kappa carrageenan based bio-nanocomposite film as an alternative to synthetic petroleum based food packaging materials. Among natural polymers, carrageenan is one of the most promising material, since it is a renewable bioresource. The ZnO nanoparticles (0.5%; 1.0%; 1.5% w/w carrageenan) was incorporated into carrageenan polymer to prepare bio-nanocomposite films, where ZnO acts as reinforcement for carrageenan matrix. The mechanical and solubility properties of the prepared films were investigated as a function of ZnO concentration. The results indicated that the addition of ZnO exhibits greater solubility compared to the neat film. The elongation at break is insignificantly different on the films with and without addition ZnO. The tensile strength of the film was highest for the sample with 0.5% ZnO. These mechanical and solubility properties suggest that bio-nanocomposite film of semi refined kappa carrageenan and nanoparticle ZnO can be effectively used as food packaging material.

Synthesis and characterization of modified κ-carrageenan for enhanced proton conductivity as polymer electrolyte membrane.

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Joy Wei Yi Liew

Full Text Available Polymer electrolyte membranes based on the natural polymer κ-carrageenan were modified and characterized for application in electrochemical devices. In general, pure κ-carrageenan membranes show a low ionic conductivity. New membranes were developed by chemically modifying κ-carrageenan via phosphorylation to produce O-methylene phosphonic κ-carrageenan (OMPC, which showed enhanced membrane conductivity. The membranes were prepared by a solution casting method. The chemical structure of OMPC samples were characterized using Fourier transform infrared spectroscopy (FTIR, 1H nuclear magnetic resonance (1H NMR spectroscopy and 31P nuclear magnetic resonance (31P NMR spectroscopy. The conductivity properties of the membranes were investigated by electrochemical impedance spectroscopy (EIS. The characterization demonstrated that the membranes had been successfully produced. The ionic conductivity of κ-carrageenan and OMPC were 2.79 × 10-6 S cm-1 and 1.54 × 10-5 S cm-1, respectively. The hydrated membranes showed a two orders of magnitude higher ionic conductivity than the dried membranes.

Bioactive compounds in industrial red seaweed used in carrageenan production

DEFF Research Database (Denmark)

Naseri, Alireza; Holdt, Susan Løvstad; Jacobsen, Charlotte

The main seaweed species used in industrial scale for carrageenan production are Kappaphycus alvarezii, Eucheuma denticulatum, Chondrus crispus, Gigartina sp. and also Furcellaria lumbricalis as a source of furcellaran (Danish Agar) is also classified together with carrageenan. The chemical...... compositions of these five industrial red seaweeds were evaluated. Protein, lipid and total phenolic content, total amino acid and composition, fatty acid profile, tocopherol content and pigment composition were analyzed. The results demonstrate that there is potential possibility to develop a method...

Characterization of radiation modified κ-carrageenan oligomers for bio-based materials development

International Nuclear Information System (INIS)

Abad, Lucille V.; Relleve, Lorna S.; Aranilla, Charito T.; Racadio, Darwin T.; Dela Rosa, Alumanda M.

2011-01-01

κ-carrageenan oligomers are known to have several biological activities such as anti-HIV, anti-herpes, antitumor and antioxidant properties. Recent progress in the development of radiation modified κ-carrageenan has resulted in new applications such as plant growth promoter, radiation dose indicator and hydrogels for wound dressing. This presentation would touch on the changes in chemical structure, gelation and conformational transition behavior and molecular size of κ-carrageenan at doses from 0 to 200 kGy and would be correlated to these functions for the development of bio-based materials. Chemical and spectral analyses were carried out using UV-Vis spectroscopy, FT-IR spectroscopy, NMR spectroscopy, reducing sugar analysis, free sulfate and carboxylic acid analysis. The chemical and spectral analyses of the radiolytic products indicated increasing reducing sugars, carbonyl, carboxylic acids, and sulfates with increasing doses which reached a maximum level at a certain dose depending on the irradiation condition. Values were very much lower in solid irradiation (in vacuum and in air) as compared to aqueous irradiation. NMR data also revealed an intact structure of the oligomer irradiated at 100 kGy in the specific fraction that contains an Mw = (3-10) kDa. κ-carrageenan oligomers exhibited antioxidant properties as determined by hydroxyl radical scavenging activity, reducing power and DPPH radical scavenging capacity assay. The degree of oxidative inhibition increased with increasing dose which can be attributed to higher reducing sugar. Dynamic light scattering (DLS) experiments showed that a dose of up to 50 kGy, sol-gelation transition was still observed. Beyond 50 kGy, no gelation took place, instead appearance of fast relax-carrageenan mode in characteristic decay time function was observed at doses of (75-150) kGy. Optimum peak intensity was found at 100 kGy (mol wt. 5-10 kDa) which coincides with the optimum plant growth promoter effect in κ-carrageenan

Amylmetacresol/2,4-dichlorobenzyl alcohol, hexylresorcinol, or carrageenan lozenges as active treatments for sore throat

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Morokutti-Kurz M

2017-02-01

Full Text Available Martina Morokutti-Kurz, Christine Graf, Eva Prieschl-Grassauer Marinomed Biotechnologie GmbH, Vienna, Austria Abstract: Up to 80% of sore throats are caused by viruses. Several over the counter products are available which provide symptomatic, not causal relief. For such lozenges, containing the antiseptics and local anesthetics amylmetacresol (AMC and 2,4-dichlorobenzyl alcohol (DCBA or hexylresorcinol (HR, recently an additional virucidal effect was published. Therefore, we tested a set of Strepsils® lozenges, containing either HR (Max [#2] or AMC/DCBA (Original [#3], Extra Strong [#4], Warm [#5], Orange and Vitamin C [#6], Sugar free Lemon [#7], Children/Strawberry [#8] and Soothing Honey and Lemon [#9] for their antiviral efficiency against representatives of respiratory viruses known to cause sore throat: human rhinovirus (HRV 1a, HRV8, influenza virus A H1N1n, Coxsackievirus A10, and human coronavirus (hCoV OC43. The lozenges were tested head to head with Coldamaris® lozenges (#1, which contain the patented antiviral iota-carrageenan. None of the tested AMC/DCBA or HR containing lozenges shows any antiviral effectiveness against HRV8 at the tested concentrations, whereas all are moderately active against HRV1a. Only lozenge #5 shows any activity against hCoV OC43 and Coxsackievirus A10 at the tested concentrations. Similarly, only lozenge #3 is moderately active against influenza A H1N1n virus. The data indicates that neither the isolated effect of the active ingredients nor the pH but rather one or more of the excipients of the specific formulations are responsible for the antiviral effect of some of the AMC/DCBA or HR containing lozenges. In contrast, carrageenan-containing lozenges are highly active against all viruses tested. In another experiment, we showed that binding and inactivation of virus particles by iota-carrageenan are fast and highly effective. During the residence time of the lozenge in the mouth, the viral titer is

Discovery of a novel iota carrageenan sulfatase isolated from the marine bacterium Pseudoalteromonas carrageenovora.

Science.gov (United States)

Genicot, Sabine M; Groisillier, Agnès; Rogniaux, Hélène; Meslet-Cladière, Laurence; Barbeyron, Tristan; Helbert, William

2014-01-01

Carrageenans are sulfated polysaccharides extracted from the cell wall of some marine red algae. These polysaccharides are widely used as gelling, stabilizing, and viscosifying agents in the food and pharmaceutical industries. Since the rheological properties of these polysaccharides depend on their sulfate content, we screened several isolated marine bacteria for carrageenan specific sulfatase activity, in the aim of developing enzymatic bioconversion of carrageenans. As a result of the screening, an iota-carrageenan sulfatase was detected in the cell-free lysate of the marine bacterium Pseudoalteromonas carrageenovora strain Psc(T). It was purified through Phenyl Sepharose and Diethylaminoethyl Sepharose chromatography. The pure enzyme, Psc ι-CgsA, was characterized. It had a molecular weight of 115.9 kDaltons and exhibited an optimal activity/stability at pH ~8.3 and at 40 ± 5°C. It was inactivated by phenylmethylsulfonyl fluoride but not by ethylene diamine tetraacetic acid. Psc ι-CgsA specifically catalyzes the hydrolysis of the 4-S sulfate of iota-carrageenan. The purified enzyme could transform iota-carrageenan into hybrid iota-/alpha- or pure alpha-carrageenan under controlled conditions. The gene encoding Psc ι-CgsA, a protein of 1038 amino acids, was cloned into Escherichia coli, and the sequence analysis revealed that Psc ι-CgsA has more than 90% sequence identity with a putative uncharacterized protein Q3IKL4 from the marine strain Pseudoalteromonas haloplanktis TAC 125, but besides this did not share any homology to characterized sulfatases. Phylogenetic studies show that P. carrageenovora sulfatase thus represents the first characterized member of a new sulfatase family, with a C-terminal domain having strong similarity with the superfamily of amidohydrolases, highlighting the still unexplored diversity of marine polysaccharide modifying enzymes.

Discovery of a novel iota carrageenan sulfatase isolated from the marine bacterium Pseudoalteromonas carrageenovora

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Sabine Marie Genicot

2014-08-01

Full Text Available Carrageenans are sulfated polysaccharides extracted from the cell wall of some marine red algae. These polysaccharides are widely used as gelling, stabilizing, and viscosifying agents in the food and pharmaceutical industries. Since the rheological properties of these polysaccharides depend on their sulfate content, we screened several isolated marine bacteria for carrageenan specific sulfatase activity, in the aim of developing enzymatic bioconversion of carrageenans. As a result of the screening, an iota-carrageenan sulfatase was detected in the cell-free lysate of the marine bacterium Pseudoalteromonas carrageenovora strain PscT. It was purified through Phenyl Sepharose and Diethylaminoethyl Sepharose chromatography. The pure enzyme, Psc -CgsA, was characterized. It had a molecular weight of 115.9 kDaltons and exhibited an optimal activity/stability at pH ~8.3 and at 40°C ± 5°C. It was inactivated by phenylmethylsulfonyl fluoride but not by ethylene diamine tetraacetic acid. Psc -CgsA specifically catalyzes the hydrolysis of the 4-S sulfate of iota-carrageenan. The purified enzyme could transform iota-carrageenan into hybrid iota-/alpha- or pure alpha-carrageenan under controlled conditions. The gene encoding Psc -CgsA, a protein of 1038 amino acids, was cloned into Escherichia coli, and the sequence analysis revealed that Psc -CgsA has more than 90% sequence identity with a putative uncharacterized protein Q3IKL4 from the marine strain Pseudoalteromonas haloplanktis TAC 125, but besides this did not share any homology to characterized sulfatases. Phylogenetic studies show that P. carrageenovora sulfatase thus represents the first characterized member of a new sulfatase family, with a C-terminal domain having strong similarity with the superfamily of amidohydrolases, highlighting the still unexplored diversity of marine polysaccharide modifying enzymes.

Macromolecular complexes of lysozyme with kappa carrageenan

NARCIS (Netherlands)

Antonov, Y.A.; Zhuravleva, I.L.; Cardinaels, R.; Moldenaers, P.

2018-01-01

We present a structural study of the complexation and binding of lysozyme (Lys) with kappa carrageenan (kCG) by means of turbidity measurements, phase analysis, dynamic and electrophoretic light scattering, differential scanning microcalorimetry (DSMC), confocal laser scanning (CLSM) microscopy,

A review on synthesis, properties and applications of natural polymer based carrageenan blends and composites.

Science.gov (United States)

Zia, Khalid Mahmood; Tabasum, Shazia; Nasif, Muhammad; Sultan, Neelam; Aslam, Nosheen; Noreen, Aqdas; Zuber, Mohammad

2017-03-01

Carrageenan is a natural polysaccharide extracted from edible red seaweeds of Rhodophycea class. It has been used as a viscosity increasing or gelling agent for prolonged and controlled drug release, food, pharmaceuticals and other industries. However, in spite of wide range of applications, carrageenan has some drawbacks and adverse effects on the biological systems, so its modifications with natural and synthetic polymers are carried out. This review article presents different sources and properties of carrageenans with special emphasis on natural polymer based carrageenan blends and composites and their applications in controlled drug delivery system, wound dressing and tissue engineering because of their biodegradability and biocompatibility, food industry as thickening/gelling materials, cosmeceuticals and making polyelectrolyte complexes. Copyright © 2016 Elsevier B.V. All rights reserved.

Specific Inhibitory Effect of κ-Carrageenan Polysaccharide on Swine Pandemic 2009 H1N1 Influenza Virus.

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Qiang Shao

Full Text Available The 2009 influenza A H1N1 pandemic placed unprecedented demands on antiviral drug resources and the vaccine industry. Carrageenan, an extractive of red algae, has been proven to inhibit infection and multiplication of various enveloped viruses. The aim of this study was to examine the ability of κ-carrageenan to inhibit swine pandemic 2009 H1N1 influenza virus to gain an understanding of antiviral ability of κ-carrageenan. It was here demonstrated that κ-carrageenan had no cytotoxicity at concentrations below 1000 μg/ml. Hemagglutination, 50% tissue culture infectious dose (TCID50 and cytopathic effect (CPE inhibition assays showed that κ-carrageenan inhibited A/Swine/Shandong/731/2009 H1N1 (SW731 and A/California/04/2009 H1N1 (CA04 replication in a dose-dependent fashion. Mechanism studies show that the inhibition of SW731 multiplication and mRNA expression was maximized when κ-carrageenan was added before or during adsorption. The result of Hemagglutination inhibition assay indicate that κ-carrageenan specifically targeted HA of SW731 and CA04, both of which are pandemic H1N/2009 viruses, without effect on A/Pureto Rico/8/34 H1N1 (PR8, A/WSN/1933 H1N1 (WSN, A/Swine/Beijing/26/2008 H1N1 (SW26, A/Chicken/Shandong/LY/2008 H9N2 (LY08, and A/Chicken/Shandong/ZB/2007 H9N2 (ZB07 viruses. Immunofluorescence assay and Western blot showed that κ-carrageenan also inhibited SW731 protein expression after its internalization into cells. These results suggest that κ-carrageenan can significantly inhibit SW731 replication by interfering with a few replication steps in the SW731 life cycles, including adsorption, transcription, and viral protein expression, especially interactions between HA and cells. In this way, κ-carrageenan might be a suitable alternative approach to therapy meant to address anti-IAV, which contains an HA homologous to that of SW731.

A Novel Enzyme Portfolio for Red Algal Polysaccharide Degradation in the Marine Bacterium Paraglaciecola hydrolytica S66T Encoded in a Sizeable Polysaccharide Utilization Locus.

Science.gov (United States)

Schultz-Johansen, Mikkel; Bech, Pernille K; Hennessy, Rosanna C; Glaring, Mikkel A; Barbeyron, Tristan; Czjzek, Mirjam; Stougaard, Peter

2018-01-01

Marine microbes are a rich source of enzymes for the degradation of diverse polysaccharides. Paraglaciecola hydrolytica S66 T is a marine bacterium capable of hydrolyzing polysaccharides found in the cell wall of red macroalgae. In this study, we applied an approach combining genomic mining with functional analysis to uncover the potential of this bacterium to produce enzymes for the hydrolysis of complex marine polysaccharides. A special feature of P. hydrolytica S66 T is the presence of a large genomic region harboring an array of carbohydrate-active enzymes (CAZymes) notably agarases and carrageenases. Based on a first functional characterization combined with a comparative sequence analysis, we confirmed the enzymatic activities of several enzymes required for red algal polysaccharide degradation by the bacterium. In particular, we report for the first time, the discovery of novel enzyme activities targeting furcellaran, a hybrid carrageenan containing both β-carrageenan and κ/β-carrageenan motifs. Some of these enzymes represent a new subfamily within the CAZy classification. From the combined analyses, we propose models for the complete degradation of agar and κ/β-type carrageenan by P. hydrolytica S66 T . The novel enzymes described here may find value in new bio-based industries and advance our understanding of the mechanisms responsible for recycling of red algal polysaccharides in marine ecosystems.

A Novel Enzyme Portfolio for Red Algal Polysaccharide Degradation in the Marine Bacterium Paraglaciecola hydrolytica S66T Encoded in a Sizeable Polysaccharide Utilization Locus

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Mikkel Schultz-Johansen

2018-05-01

Full Text Available Marine microbes are a rich source of enzymes for the degradation of diverse polysaccharides. Paraglaciecola hydrolytica S66T is a marine bacterium capable of hydrolyzing polysaccharides found in the cell wall of red macroalgae. In this study, we applied an approach combining genomic mining with functional analysis to uncover the potential of this bacterium to produce enzymes for the hydrolysis of complex marine polysaccharides. A special feature of P. hydrolytica S66T is the presence of a large genomic region harboring an array of carbohydrate-active enzymes (CAZymes notably agarases and carrageenases. Based on a first functional characterization combined with a comparative sequence analysis, we confirmed the enzymatic activities of several enzymes required for red algal polysaccharide degradation by the bacterium. In particular, we report for the first time, the discovery of novel enzyme activities targeting furcellaran, a hybrid carrageenan containing both β-carrageenan and κ/β-carrageenan motifs. Some of these enzymes represent a new subfamily within the CAZy classification. From the combined analyses, we propose models for the complete degradation of agar and κ/β-type carrageenan by P. hydrolytica S66T. The novel enzymes described here may find value in new bio-based industries and advance our understanding of the mechanisms responsible for recycling of red algal polysaccharides in marine ecosystems.

Trichilia monadelpha Bark Extracts Inhibit Carrageenan-Induced ...

African Journals Online (AJOL)

The present study was undertaken to evaluate the anti-inflammatory properties of aqueous (TWE), alcoholic (TAE) and petroleum ether extract (TPEE) of T. ... The reference anti-inflammatory drugs (diclofenac and dexamethasone) inhibited the chick-carrageenan-induced footpad oedema, with maximal inhibitions of ...

Quantification of free formaldehyde in carrageenan and processed Eucheuma seaweed using high-performance liquid chromatography.

Science.gov (United States)

Hornshøj, Bettina Høj; Kobbelgaard, Sara; Blakemore, William R; Stapelfeldt, Henrik; Bixler, Harris J; Klinger, Markus

2015-01-01

In 2010 the European Commission placed a limit on the amount of free formaldehyde in carrageenan and processed Eucheuma seaweed (PES) of 5 mg kg(-1). Formaldehyde is not used in carrageenan and PES processing and accordingly one would not expect free formaldehyde to be present in carrageenan and PES. However, surprisingly high levels up to 10 mg kg(-1) have been found using the generally accepted AOAC and Hach tests. These findings are, per proposed reaction pathways, likely due to the formation of formaldehyde when sulphated galactose, the backbone of carrageenan, is hydrolysed with the strong acid used in these conventional tests. In order to minimise the risk of false-positives, which may lead to regulatory non-compliance, a new high-performance liquid chromatography (HPLC) method has been developed. Initially, carrageenan or PES is extracted with 2-propanol and subsequently reacted with 2,4-dinitrophenylhydrazine (DNPH) to form the chromophore formaldehyde-DNPH, which is finally quantified by reversed-phase HPLC with ultraviolet light detection at 355 nm. This method has been found to have a limit of detection of 0.05 mg kg(-1) and a limit of quantification of 0.2 mg kg(-1). Recoveries from samples spiked with known quantities of formaldehyde were 95-107%. Using this more specific technique, 20 samples of carrageenan and PES were tested for formaldehyde. Only one sample had a detectable content of formaldehyde (0.40 mg kg(-1)), thus demonstrating that the formaldehyde content of commercial carrageenan and PES products are well below the European Commission maximum limit of 5 mg kg(-1).

Effect of carrageenans alone and in combination with casein or lipopolysaccharide on human epithelial intestinal HT-29 cells.

Science.gov (United States)

Sokolova, E V; Kuz'mich, A S; Byankina, A O; Yermak, I M

2017-10-01

The research described here was focused on the effect on human intestinal epithelial cell monolayers of sulfated red algal polysaccharides (κ-, λ-, and κ/β-carrageenans) alone and in combination with casein or lipopolysaccharide (LPS). HT-29 cells were investigated under normal and stress conditions; stress was induced by exposure to ethanol. Cell viability was monitored with a real-time system. The change in binding properties of negatively sulfated red algal polysaccharides assessed by the measurement of free carrageenans in mixtures with casein or McCoy's 5 A culture medium by means of toluidine blue O. Low sulfate content and the presence of 3,6-anhydogalactose are prerequisites for the recovery of ethanol-exposed HT-29 cells by carrageenans. Analysis of carrageenan binding ability confirmed that casein and LPS should affect carrageenan activity. Whether the combined action of the mucin-containing layer and carrageenans or the action of carrageenans alone was responsible for enhanced cell viability under stress conditions induced by ethanol is a subject for further research. © 2017 Wiley Periodicals Inc. J Biomed Mater Res Part A: 105A: 2843-2850, 2017. © 2017 Wiley Periodicals, Inc.

Environmental Degradation: Causes and Consequences

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Swati Tyagi

2014-08-01

Full Text Available The subject of environmental economics is at the forefront of the green debate: the environment can no longer be viewed as an entity separate from the economy. Environmental degradation is of many types and have many consequences. To address this challenge a number of studies have been conducted in both developing and developed countries applying different methods to capture health benefits from improved environmental quality. Minimizing exposure to environmental risk factors by enhancing air quality and access to improved sources of drinking and bathing water, sanitation and clean energy is found to be associated with significant health benefits and can contribute significantly to the achievement of the Millennium Development Goals of environmental sustainability, health and development. In this paper, I describe the national and global causes and consequences of environmental degradation and social injustice. This paper provides a review of the literature on studies associated with reduced environmental risk and in particular focusing on reduced air pollution, enhanced water quality and climate change mitigation.

Protein oxidation and degradation caused by particulate matter

Science.gov (United States)

Lai, Ching-Huang; Lee, Chun-Nin; Bai, Kuan-Jen; Yang, You-Lan; Chuang, Kai-Jen; Wu, Sheng-Ming; Chuang, Hsiao-Chi

2016-09-01

Particulate matter (PM) modulates the expression of autophagy; however, the role of selective autophagy by PM remains unclear. The objective of this study was to determine the underlying mechanisms in protein oxidation and degradation caused by PM. Human epithelial A549 cells were exposed to diesel exhaust particles (DEPs), urban dust (UD), and carbon black (CB; control particles). Cell survival and proliferation were significantly reduced by DEPs and UD in A549 cells. First, benzo(a)pyrene diolepoxide (BPDE) protein adduct was caused by DEPs at 150 μg/ml. Methionine oxidation (MetO) of human albumin proteins was induced by DEPs, UD, and CB; however, the protein repair mechanism that converts MetO back to methionine by methionine sulfoxide reductases A (MSRA) and B3 (MSRB3) was activated by DEPs and inhibited by UD, suggesting that oxidized protein was accumulating in cells. As to the degradation of oxidized proteins, proteasome and autophagy activation was induced by CB with ubiquitin accumulation, whereas proteasome and autophagy activation was induced by DEPs without ubiquitin accumulation. The results suggest that CB-induced protein degradation may be via an ubiquitin-dependent autophagy pathway, whereas DEP-induced protein degradation may be via an ubiquitin-independent autophagy pathway. A distinct proteotoxic effect may depend on the physicochemistry of PM.

Improvement of mechanical properties of hydrogel by irradiation of polymers in aqueous solution with κ-carrageenan

International Nuclear Information System (INIS)

Makuuchi, K.; Yoshii, F.; Zhai, M.

2000-01-01

Predominate radiation reaction of κ-carrageenan (KC) hydrogel is the main chain scission of KC. The gel strength of KC hydrogel decreased with increasing irradiation dose. However, KC was found to enhances the radiation crosslinking of synthetic water-soluble polymer (SWSP) such as poly(ethylene oxide) (PEO) and poly(N-vinylpyrolidone) (PVP) in aqueous solution. The gel strength of SWSP hydrogel increased with increasing dose when KC was blended. Probably the radiation degraded KC radicals are recombined with radicals of PVP and PEO. The hydrogel thus prepared absorbs huge amounts of water due to the presence of strong hydrophilic -OSO 3 - groups in KC. (author)

Improvement of mechanical properties of hydrogel by irradiation of polymers in aqueous solution with {kappa}-carrageenan

Energy Technology Data Exchange (ETDEWEB)

Makuuchi, K.; Yoshii, F. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Aranilla, C.T. [Philippine Nuclear Research Institute, Diliman, Quezon (Philippines); Zhai, M. [Department of Technical Physics, Peking Univ., Beijing (China)

2000-03-01

Predominate radiation reaction of {kappa}-carrageenan (KC) hydrogel is the main chain scission of KC. The gel strength of KC hydrogel decreased with increasing irradiation dose. However, KC was found to enhances the radiation crosslinking of synthetic water-soluble polymer (SWSP) such as poly(ethylene oxide) (PEO) and poly(N-vinylpyrolidone) (PVP) in aqueous solution. The gel strength of SWSP hydrogel increased with increasing dose when KC was blended. Probably the radiation degraded KC radicals are recombined with radicals of PVP and PEO. The hydrogel thus prepared absorbs huge amounts of water due to the presence of strong hydrophilic -OSO{sub 3}{sup -} groups in KC. (author)

Status report on the collaborative project on the sans of K-carrageenan

International Nuclear Information System (INIS)

Calix, V.S.

2006-01-01

In the 2001 Beijing workshop, the Philippines proposed studies on the SANS of a natural biopolymer carrageenan. Several studies were submitted which were reviewed and evaluated by the Japanese scientist (1). On the basis of the economic importance and support of the Philippine government, in addition to it satisfying the requirement of FNCA, the proposal was accepted to be conducted in collaboration with the Prof. M. Shibayama of ISSP-Tokyo University. Two studies were proposed by the Philippines: 1. Structural investigation of γ-irradiated K-carrageenan. 2. Structural investigation of K-carrageenan/PVP blend cross linked by γ-irradiation. The report discusses the progress of the different activities related to the proposed studies done in the Philippines and the one currently being undertaken under the MEXT Exchange Program at JAERI, Tokai by a researcher who joined the group of Prof. M. Shibayama. (author)

Carrageenan-Induced Colonic Inflammation Is Reduced in Bcl10 Null Mice and Increased in IL-10-Deficient Mice

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Sumit Bhattacharyya

2013-01-01

Full Text Available The common food additive carrageenan is a known activator of inflammation in mammalian tissues and stimulates both the canonical and noncanonical pathways of NF-κB activation. Exposure to low concentrations of carrageenan (10 μg/mL in the water supply has produced glucose intolerance, insulin resistance, and impaired insulin signaling in C57BL/6 mice. B-cell leukemia/lymphoma 10 (Bcl10 is a mediator of inflammatory signals from Toll-like receptor (TLR 4 in myeloid and epithelial cells. Since the TLR4 signaling pathway is activated in diabetes and by carrageenan, we addressed systemic and intestinal inflammatory responses following carrageenan exposure in Bcl10 wild type, heterozygous, and null mice. Fecal calprotectin and circulating keratinocyte chemokine (KC, nuclear RelA and RelB, phospho(Thr559-NF-κB-inducing kinase (NIK, and phospho(Ser36-IκBα in the colonic epithelial cells were significantly less (P<0.001 in the carrageenan-treated Bcl10 null mice than in controls. IL-10-deficient mice exposed to carrageenan in a germ-free environment showed an increase in activation of the canonical pathway of NF-κB (RelA activation, but without increase in RelB or phospho-Bcl10, and exogenous IL-10 inhibited only the canonical pathway of NF-κB activation in cultured colonic cells. These findings demonstrate a Bcl10 requirement for maximum development of carrageenan-induced inflammation and lack of complete suppression by IL-10 of carrageenan-induced inflammation.

Carbohydrate availability of arroz caldo with lambda-carrageenan.

Science.gov (United States)

Dumelod, B D; Ramirez, R P; Tiangson, C L; Barrios, E B; Panlasigui, L N

1999-07-01

Total available carbohydrate (sugars and starches) and total dietary fiber (soluble and insoluble) make up the total carbohydrate content of a food. Soluble fiber decreases the availability of glucose by delaying its absorption in the proximal small intestine, thus reducing the postprandial glucose levels (Jenkins et al., 1978; Schneeman, 1987a). Carrageenan, a seaweed extract, is a good source of soluble fiber (Montaño et al., 1985). This study aimed to determine the effect of carrageenan incorporation into arroz caldo on carbohydrate availability by monitoring the postprandial blood glucose levels of normal subjects. Control and experimental arroz caldo samples were prepared and subjected to proximate analysis and feeding studies. The total dietary fiber (TDF) content of the experimental (2.03%) was about thrice that of the control (0.68%). Using randomized crossover design, preweighed 55 g available carbohydrate serving portions of control and experimental arroz caldo samples, with 3.45 and 14.84 g TDF, respectively, were fed to ten fasting normal subjects then their postprandial blood glucose levels were determined at 15, 30, 45, 60 and 90 min intervals. Results of the short-term in vivo study showed that the mean postprandial glycaemic responses of subjects after consuming the experimental sample were significantly lower than the levels after consuming the control at 15, 45, and 90 min (P arroz caldo than control (147.29 +/- 53.34). The hypoglycaemic effect of carrageenan may prove useful in the prevention and management of metabolic conditions such as diabetes.

Discovery of novel algae-degrading enzymes from marine bacteria

DEFF Research Database (Denmark)

Schultz-Johansen, Mikkel; Bech, Pernille Kjersgaard; Hennessy, Rosanna Catherine

Algal cell wall polysaccharides, and their derived oligosaccharides, display a range of health beneficial bioactive properties. Enzymes capable of degrading algal polysaccharides into oligosaccharides may be used to produce biomolecules with new functionalities for the food and pharma industry....... Some marine bacteria are specialized in degrading algal biomass and secrete enzymes that can decompose the complex algal cell wall polysaccharides. In order to identify such bacteria and enzymatic activities, we have used a combination of traditional cultivation and isolation methods, bioinformatics...... and functional screening. This resulted in the discovery of a novel marine bacterium which displays a large enzymatic potential for degradation of red algal polysaccharides e.g. agar and carrageenan. In addition, we searched metagenome sequence data and identified new enzyme candidates for degradation...

Aspidosperma pyrifolium Has Anti-Inflammatory Properties: An Experimental Study in Mice with Peritonitis Induced by Tityus serrulatus Venom or Carrageenan.

Science.gov (United States)

Souza Lima, Maíra Conceição Jerônimo de; Oliveira Bitencourt, Mariana Angélica; Furtado, Allanny Alves; Torres-Rêgo, Manoela; Siqueira, Emerson Michell da Silva; Oliveira, Ruth Medeiros; Oliveira Rocha, Hugo Alexandre; Ferreira Rocha, Keyla Borges; Silva-Júnior, Arnóbio Antônio da; Zucolotto, Silvana Maria; Fernandes-Pedrosa, Matheus de Freitas

2017-11-11

Scorpions of the genus Tityus are responsible for the majority of envenomation in Brazil, the Tityus serrulatus species being the most common and dangerous in South America. In this approach, we have investigated the ability of the aqueous extract from the leaves of Aspidosperma pyrifolium in reducing carrageenan-induced inflammation and the inflammation induced by T. serrulatus envenomation in mice. We also evaluated the cytotoxic effects of this extract, using the 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl-2H-tetrazolium (MTT) assay and the results revealed that the extract is safe. Analysis by High Performance Liquid Chromatography coupled with Diode Array Detector (HPLC-DAD) and Liquid Chromatography Coupled with Mass Spectrometry with Diode Array Detection (LC-DAD-MS) showed one major chemical component, the flavonoid rutin and phenolics compounds. For in vivo studies in carrageenan-induced peritonitis model, mice received extracts, dexamethasone, rutin or saline, before administration of carrageenan. For venom-induced inflammation model, animals received T. serrulatus venom and were, simultaneously, treated with extracts, antivenom, rutin or saline. The extract and rutin showed a reduction in the cell migration into the peritoneal cavity, and in the same way the envenomated animals also showed reduction of edema, inflammatory cell infiltration and vasodilation in lungs. This is an original study revealing the potential action of A. pyrifolium against inflammation caused by Tityus serrulatus venom and carrageenan, revealing that this extract and its bioactive molecules, specifically rutin, may present potential anti-inflammatory application.

In vitro inhibition of human papillomavirus following use of a carrageenan-containing vaginal gel.

Science.gov (United States)

Novetsky, Akiva P; Keller, Marla J; Gradissimo, Ana; Chen, Zigui; Morgan, Stephanie L; Xue, Xiaonan; Strickler, Howard D; Fernández-Romero, José A; Burk, Robert; Einstein, Mark H

2016-11-01

To assess in vitro efficacy of Divine 9, a carrageenan-based vaginal lubricant that is being studied as a microbicide to inhibit HPV16 pseudovirus (PsV) infection. Sexually active US women between 19 and 35years without prior HPV vaccination or cervical intraepithelial neoplasia were instructed to use Divine 9 vaginally with an applicator either before sex only or before and after intercourse. Women who applied a single dose of gel returned for cervicovaginal lavage (CVL) collection 1, 4 or 8-12h after intercourse versus those who applied gel before and after intercourse returned 1, 4 or 8-12h after the second gel dose. Carrageenan concentrations were assessed using an ELISA assay and the inhibitory activity was assessed using a PsV-based neutralization assay against HPV16 infection. Carrageenan concentrations and the percentage of PsV16 inhibition were compared using the Wilcoxon rank sum test. Thirteen women were enrolled and thirty specimens from different time-points were assessed. 87% of CVL samples had detectable carrageenans with levels decreasing over time from intercourse. 93% of CVL samples had detectable PsV16 inhibition with median inhibition of 97.5%. PsV16 inhibition decreased over time, but remained high, with median inhibition of 98.1%, 97.4% and 83.4% at 1, 4 and 8-12h, respectively. Higher carrageenan concentrations were associated with higher levels of PsV16 inhibition (rho=0.69). This is the first report of a human study investigating in vitro HPV inhibition of a carrageenan-based vaginal lubricant with CVL collected after sexual intercourse. We demonstrate excellent efficacy in preventing PsV16 infection. Copyright © 2016 Elsevier Inc. All rights reserved.

Chemical investigation of carrageenan from the red alga Sarconema filiforme (Gigartinales, Rhodophyta) of Indian waters.

Science.gov (United States)

Kumar, Sanjay; Mehta, Gaurav K; Prasad, Kamalesh; Meena, Ramavtar; Siddhanta, Arup K

2011-09-01

Sulphated galactan (SF(A)) containing alpha (alpha), iota (i) and pyruvated alpha-carrageenans (17.6:18.8:25.3 mol %) was extracted and characterized from Sarconema filiforme of Indian waters. The SF(A) and its alkali modified derivative (SF(AM)) were composed of D-galactose, 3, 6-anhydro-D-galactose, 6-O-methylated-D-galactose (64.5:23.0:9.8 and 59.6:29.8:7.6 mol %) respectively. The linkage analysis, physicochemical analysis, infra red and 13C nuclear magnetic resonance spectra of SFA along with linkage analysis of the desulphated derivative (SF(D)) of SFA, reveals that it was a hybrid/combination of alpha/iota carrageenan as well as 3-linked 4',6'-O-(1-carboxyethylidene)-galactose (pyruvated alpha carrageenan) and 6-O-methylated alpha-carrageenan. The flow behavior of SF(A) obtained from rheological measurements suggested strong network formation in presence of 1% aqueous KCl and CaCl2 solutions.

On the structure of K/l-hybrid carrageenans

NARCIS (Netherlands)

Velde, F. van de; Peppelman, H.A.; Rollema, H.S.; Tromp, R.H.

2001-01-01

The coil-to-helix transition and temperature dependence of the viscosity of commercial κ/ι-hybrid carrageenans produced by the red algae Sarcothalia crispata, Mazaella laminarioides, and Chondrus crispus were studied using rheometry and optical rotation. The structure of these κ/ι-hybrid

Formation of carrageenan-CaCO{sub 3} bioactive membranes

Energy Technology Data Exchange (ETDEWEB)

Nogueira, Lucas F.B.; Maniglia, Bianca C.; Pereira, Lourivaldo S.; Tapia-Blácido, Delia R.; Ramos, Ana P., E-mail: anapr@ffclrp.usp.br

2016-01-01

The high biocompatibility and resorbability of polymeric membranes have encouraged their use to manufacture medical devices. Here, we report on the preparation of membranes consisting of carrageenan, a naturally occurring sulfated polysaccharide that forms helical structures in the presence of calcium ions. We incorporated CaCO{sub 3} particles into the membranes to enhance their bioactivity and mechanical properties. Infrared spectroscopy and X-ray diffraction data confirmed CaCO{sub 3} incorporation into the polymeric matrix. We tested the bioactivity of the samples by immersing them in a solution that mimics the ionic composition and pH of the human body fluid. The hybrid membranes generated hydroxyapatite, as attested by X-ray diffraction data. Scanning electron and atomic force microscopies aided investigation of membrane topography before and after CaCO{sub 3} deposition. The wettability and surface free energy, evaluated by contact angle measures, increased in the presence of CaCO{sub 3} particles. These parameters are important for membrane implantation in the body. Moreover, membrane stiffness was up to 110% higher in the presence of the inorganic particles, as revealed by Young's modulus. - Highlights: • Hybrid kappa and iota carrageenan-CaCO{sub 3} membranes were formed. • The hybrid membrane's origin hydroxyapatite after exposure to simulated body fluid • The carrageenan's specificity to bind Ca{sup 2+} ions tailors the surface properties.

Sodium Caseinate-Carrageenan Biopolymeric Nanocomplexes as a Carrier of Vitamin D: Study of Complex Formation, Particles Size and Encapsulation Efficiency

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Maryam Khoshmanzar

2014-04-01

Full Text Available The protein-polysaccharide complex-based nanocapsule is one type of polymeric nanocarrier which can be potentially useful for encapsulation of hydrophobic nutraceuticals. In this research, caseinate-carrageenan complex was used for encapsulation of vitamin D. The complex formation between caseinate and carrageenan was carried out by lowering the pH under isoelectric point of protein. The Fourier transform infrared spectroscopy (FTIR and differential scanning colorimetry (DSC confirmed complex formation between carrageenan, caseinate and vitamin D. The particle size of 1% caseinate particles was in the range of 150-300 nanometer and by addition of vitamin D the particle size increased to 450-750 nanometer. Moreover, carrageenan of all concentrations (at constant concentration of caseinate (1% and pH4.9 resulted in lower particle size below 100 nanometer. The stability of caseinate and its complex formation with carrageenan showed that encapsulation was achieved at 45% efficiency and also vitamin D stability (during 5 days storage was higher in nanocomplex compared to pure caseinate particles (60-63% compared to 53%. The complex formation between caseinate and carrageenan was carried out by pH decreasing under isoelectric point of protein. The FTIR and DSC confirmed complex formation between carrageenan, caseinate and vitamin D. The particle size of caseinate 1% particles were in the range of 150 -300 nanometer and with adding vitamin D, particle size increased to 450-750 nanometer. Moreover, adding carrageenan at all used concentration (at constant concentration of caseinate (1% and pH4.9 resulted in reduced particle size to less than 100 nanometer and vitamin D stability (during 5 days storage was higher (60-63% in nanocomplex compared to pure caseinate particles (53%.The protein-polysaccharide complex based nanocapsule is one type of the polymeric nanocarriers which can potentially be used for encapsulation of hydrophobic nutraceuticals. In

Landscape degradation at different spatial scales caused by aridification

OpenAIRE

Meyer Burghard Christian; Mezősi Gábor; Kovács Ferenc

2017-01-01

Landscape responses to degradation caused by aridification bring the landscape system into a new equilibrium state. The system transformation may entail irreversible changes to its constituting parameters. This paper analyses the impact of aridification on landscape degradation processes in the sand-covered landscapes of the Hungarian Danube-Tisza Interfluve region at the regional, landscape, and local site scales. Changes in groundwater level (well data), lake surface area (Modified Normaliz...

On the employment of lambda carrageenan in a matrix system. III. Optimization of a lambda carrageenan-HPMC hydrophilic matrix

NARCIS (Netherlands)

Bonferoni, MC; Rossi, S; Ferrari, F; Bertoni, M; Bolhuis, GK; Caramella, C

1998-01-01

The lambda carrageenan/HPMC ratio in matrix tablets has been optimized in order to obtain pH-independent release profiles of chlorpheniramine maleate, a freely soluble drug. Release profiles in acidic (pH 1.2) and neutral (pH 6.8) media were fitted according to the Weibull and the power law models.

Physicochemical and Antibacterial Properties of Carrageenan and Gelatine Hydrosols and Hydrogels Incorporated with Acidic Electrolyzed Water

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Ewa Brychcy

2015-12-01

Full Text Available The article focuses on investigation of the effects of usage of acidic electrolyzed water (AEW with different sodium chloride concentration (0.001%, 0.01%, and 0.1% for the preparation of carrageenan and gelatine hydrosols and hydrogels. To determine physiochemical properties of hydrosols, the pH, oxidation-reduction potential (ORP, available chloride concentration (ACC and rheological parameters such us gelation and flow temperatures were measured. The samples were also characterized using Fourier transform infrared spectroscopy (FT IR and texture profile analysis (TPA. Additionally, the article contains an analysis of antibacterial activity of carrageenan and gelatine hydrosols incorporated with acidic electrolyzed water, against Staphylococcus aureus and Escherichia coli. The FT IR spectra demonstrated that the structure of gelatine and carrageenan are not significantly affected by electrolyzed NaCl solution components. Furthermore, TPA analysis showed that the use of AEW did not cause undesirable changes in hydrogels layer. The microbiological analysis confirmed inhibition of bacterial growth by hydrosols to about 2.10 log reduction. The results showed that the range of reduction of microorganisms depends on the type AEW used. This might be explained by the fact that the lowest pH and the highest ACC values of hydrosols were obtained for samples with the longest period of exposure to electrolysis (10 min and the highest amount of NaCl (0.1% w/v. These results suggest that hydrogels and hydrosols incorporated with AEW may be used for food preservation.

The addition of nanochitosan suspension as filler in carrageenan-tapioca biocomposite film

Science.gov (United States)

Rochima, Emma; Fiyanih, Elisah; Afrianto, Eddy; Subhan, Ujang; Praseptiangga, Danar; Panatarani, Camellia; Joni, I. Made

2018-02-01

This research aimed to investigate the effect of nanochitosan (CSNPs) suspension by beads milling method as filler in carrageenan-tapioca biocomposite film. In addition, the antibacterial activity of CSNPs as filler with two food pathogenic bacteria, Staphylococcus aureus and Escherichia coli and then influence of nano fillers for appearance of films were observed. The incorporation of CSNPs suspension with 0.5, 1, 1.5 and 2 (%v/v) in carrageenan-tapioca film exhibited antibacterial activity againts both bacteria. CSNPs had slightly higher antimicrobial activity against E. coli aureus compared to S. aureus at all concentrations due to different mechanisms. Therefore, the best antimicrobial activity was obtained from 1 wt%. Furthermore the best antimicrobial activity was characterized by means of the thickness and transparency. The result showed that the thickness of film was 0.059 mm and the transparency was 87.88. It was concluded that the incorporation of CSNPs suspension 1 wt% in carrageenan-tapioca composite film is suitable for developing active packaging.

Radioprotection potential of the ascorbic acid on the carrageenan used as food additive

International Nuclear Information System (INIS)

Aliste, Antonio Joao; Mastro, Nelida Lucia del

2002-01-01

Carrageenans are a group of natural carbohydrates that are present in the structure of certain varieties of red algae (Rhodophyceae). They are used in emulsions, for syneresis control and to grow up, to promote adhesiveness and dispersion. In the industry of foods they can be used for instance, as thickness and gelling agents, alone or together with other additives. The processing of foods by radiation is increasing considerably, because the efficiency of the process in the industrial decontamination of products. The objective of this work was to study the action of the ascorbic acid as potential radioprotector of the carrageenan against 60 Co gamma radiation effects, using the viscosity as parameter. Samples of commercial carrageenan dissolved at 1,0% were irradiated in the presence or not of ascorbic acid, with doses of 0.0 kGy; 1.0 kGy; 2.5 kGy; 5.0 kGy and 10.0 kGy. After the irradiation the relationships viscosity/dose were established for the temperature of 60 deg C. For the dose of 10.0 kGy a better protecting effect of the ascorbic acid on the carrageenan was seen. The implications of the use of this antioxidant is discussed as a form of minimizing the effect of the radiation in irradiated foods. (author)

Positron annihilation lifetime studies of sol-gel transition of carrageenan gels

International Nuclear Information System (INIS)

Wakabayashi, Y.; Ito, K.; Li, H.L.; Ujihara, Y.

1996-01-01

Positron annihilation lifetime measurement was applied to study the sol-gel transition of anionic polysaccharide aqueous solutions in terms of free-volume parameters the size, intensity, and size distribution of free volumes of the gelation of K-form κ-carrageenan solutions as a function of temperature. Slight variations of free volume size and intensity against temperature were observed near 295 K. The correlation of free-volume data with other physical properties vibrational spectra (IR and Raman), conductivity, SAXS, elastic measurement, differential scanning calorimetry were investigated to understand the mechanism of sol-gel transition of carrageenan. (author)

Sinularin from Indigenous Soft Coral Attenuates Nociceptive Responses and Spinal Neuroinflammation in Carrageenan-Induced Inflammatory Rat Model

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Zhi-Hong Wen

2012-08-01

Full Text Available Three decades ago, the marine-derived compound sinularin was shown to have anti-edematous effects on paw edema induced by carrageenan or adjuvant. To the best of our knowledge, no new studies were conducted to explore the bioactivity of sinularin until we reported the analgesic properties of sinularin based on in vivo experiments. In the present study, we found that sinularin significantly inhibits the upregulation of proinflammatory proteins, inducible nitric oxide synthase (iNOS, and cyclooxygenase-2 (COX-2 and upregulates the production of transforming growth factor-β (TGF-β in lipopolysaccharide (LPS-stimulated murine macrophage RAW 264.7 cells according to western blot analysis. We found that subcutaneous (s.c. administration of sinularin (80 mg/kg 1 h before carrageenan injection significantly inhibited carrageenan-induced nociceptive behaviors, including thermal hyperalgesia, mechanical allodynia, cold allodynia, and hindpaw weight-bearing deficits. Further, s.c. sinularin (80 mg/kg significantly inhibited carrageenan-induced microglial and astrocyte activation as well as upregulation of iNOS in the dorsal horn of the lumbar spinal cord. Moreover, s.c. sinularin (80 mg/kg inhibited carrageenan-induced tissue inflammatory responses, redness and edema of the paw, and leukocyte infiltration. The results of immunohistochemical studies indicate that s.c. sinularin (80 mg/kg could upregulate production of TGF-β1 in carrageenan-induced inflamed paw tissue. The present results demonstrate that systemic sinularin exerts analgesic effects at the behavioral and spinal levels, which are associated with both inhibition of leukocyte infiltration and upregulation of TGF-β1.Three decades ago, the marine-derived compound sinularin was shown to have anti-edematous effects on paw edema induced by carrageenan or adjuvant. To the best of our knowledge, no new studies were conducted to explore the bioactivity of sinularin until we reported the

Sex Difference in Oxytocin-Induced Anti-Hyperalgesia at the Spinal Level in Rats with Intraplantar Carrageenan-Induced Inflammation.

Science.gov (United States)

Chow, Lok-Hi; Chen, Yuan-Hao; Wu, Wan-Chuan; Chang, En-Pei; Huang, Eagle Yi-Kung

2016-01-01

Previously, we demonstrated intrathecal administration of oxytocin strongly induced anti-hyperalgesia in male rats. By using an oxytocin-receptor antagonist (atosiban), the descending oxytocinergic pathway was found to regulate inflammatory hyperalgesia in our previous study using male rats. The activity of this neural pathway is elevated during hyperalgesia, but whether this effect differs in a sex-dependent manner remains unknown. We conducted plantar tests on adult male and female virgin rats in which paw inflammation was induced using carrageenan. Exogenous (i.t.) application of oxytocin exerted no anti-hyperalgesic effect in female rats, except at an extremely high dose. Female rats exhibited similar extent of hyperalgesia to male rats did when the animals received the same dose of carrageenan. When atosiban was administered alone, the severity of hyperalgesia was not increased in female rats. Moreover, insulin-regulated aminopeptidase (IRAP) was expressed at higher levels in the spinal cords of female rats compared with those of male rats. Oxytocin-induced anti-hyperalgesia exhibits a sex-dependent difference in rats. This difference can partially result from the higher expression of IRAP in the spinal cords of female rats, because IRAP functions as an enzyme that degrades oxytocin. Our study confirms the existence of a sex difference in oxytocin-induced anti-hyperalgesia at the spinal level in rats.

The effect of temperature and time of extraction on the quality of Semi Refined Carrageenan (SRC

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Heriyanto Heri

2018-01-01

Full Text Available Euchema cottonii is a good source of kappa-carrageenan and can be found cultivated in the Indonesia coastal areas in which one of them is in Banten Province. Carrageenans have many applications and are utilized in human food and pet-food industry. Carrageenans are also utilized in non-food industry such as pharmaceuticals, cosmetics, printing and textile formulations. Hence, the present study features on the cooking process cooking time and cooking temperature. The effects of these parameters on carrageenan quality such as gel viscosity and gel strength were studied. The process of extraction of carrageenan was conducted with variations temperature: 60, 70, and 80 °C and the variation of time: 1, 2, and 3 hours. Alkaline substance used was KOH with 8% concentration and the ratio of solvent to dry seaweed 8:1. From the present investigation, it was observed that SRC extraction reached the best condition at temperature 70 °C for 2 hours with the value of yield 30.20%, 5.90% moisture content, 18.34% ash content, sulfate content of 6.94%, viscosity of 190 cP, and the gel strength 714.45 g / cm2. The treatment of temperature and extraction time significantly affected the quality of the SRC yield parameter, viscosity and gel strength.

Effect of different vehicles in carrageenan suspension on the rate of the inflammatory response of chicks

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Alda Maria Backx Noronha Madeira

1995-12-01

Full Text Available This paper describes the pattern of edema, increased vascular permeability and cellular exudation elicited by the injection of different carrageenan suspensions into the foot pad of 80 male chicks, three to four-week old. Carrageenan suspensions at 0.5% were prepared in: Ringer Locke solution (RL, glucose aqueous solution 0.1% (G, demineralized water (W or phosphate buffered saline (PBS. The foot pad volume and vascular permeability were evaluated by pletismography and by Evans blue extravasation, respectively, before and at 0:15, 0:30, 1:00, 1:30, 2:00, 2:30, 3:00, 3:30 and 4:00 hours after injury. Cellular exudation was observed in thin sections of stained tissue 0:30, 1:30, 2:30 and 4:00 hours after injection of the carrageenan or vehicle only. The inflammatory response varied according to the carrageenan suspension used. Suspension C/PBS induced a less intense inflammatory response in foot pads of chicks than C/W, C/G and C/RL suspensions.

Magnetically tunable elasticity for magnetic hydrogels consisting of carrageenan and carbonyl iron particles.

Science.gov (United States)

Mitsumata, Tetsu; Honda, Atomu; Kanazawa, Hiroki; Kawai, Mika

2012-10-11

A new class of magnetoelastic gel that demonstrates drastic and reversible changes in storage modulus without using strong magnetic fields was obtained. The magnetic gel consists of carrageenan and carbonyl iron particles. The magnetic gel with a volume fraction of magnetic particles of 0.30 exhibited a reversible increase by a factor of 1400 of the storage modulus upon a magnetic field of 500 mT, which is the highest value in the past for magnetorheological soft materials. It is considered that the giant magnetoelastic behavior is caused by both high dispersibility and high mobility of magnetic particles in the carrageenan gel. The off-field storage modulus of the magnetic gel at volume fractions below 0.30 obeyed the Krieger-Dougherty equation, indicating random dispersion of magnetic particles. At 500 mT, the storage modulus was higher than 4.0 MPa, which is equal to that of magnetic fluids, indicating that the magnetic particles move and form a chain structure by magnetic fields. Morphological study revealed the evidence that the magnetic particles embedded in the gel were aligned in the direction of magnetic fields, accompanied by stretching of the gel network. We conclude that the giant magnetoelastic phenomenon originates from the chain structure consisting of magnetic particles similar to magnetic fluids.

Preparation and characterization of semi-refined kappa carrageenan-based edible film for nano coating application on minimally processed food

Science.gov (United States)

Manuhara, Godras Jati; Praseptiangga, Danar; Muhammad, Dimas Rahadian Aji; Maimuni, Bawani Hindami

2016-02-01

Shorter and easier processing of semi-refined kappa carrageenan extracted from Euchema cottonii red seaweed result in cheaper price of the polysaccharide. In this study, edible film was prepared from the semi-refined carrageenan without any salt addition. The effect of the carrageenan concentration (1.0, 1.5, and 2.0% w/v) on physical and mechanical properties of the edible film was studied. Edible film thickness and tensile strength increased but elongation at break and water vapor transmission rate (WVTR) decreased as the concentration increased. Based on the characteristic of the edible film, formulation using 2% carrageenan was recommended. The edible film demonstrated the characteristic as follow: 0.054 mm thickness, 21.14 MPa tensile strength, 12.36% elongation at break, and 9.56 g/m2.hour WVTR. It was also noted the carrageenan-based edible film indicated potential physical and mechanical characteristics for nano coating applications on minimally processed food.

Radiation effects on agar, alginates and carrageenan to be used as food additives

International Nuclear Information System (INIS)

Aliste, A.J.; Vieira, F.F.; Mastro, N.L. del

2000-01-01

Agar, alginates and carrageenan are hydrocolloids that induce stabilization of physical properties of the food product during shelf life and prevention of undesirable changes such as moisture migration, gas cell coalescence or textural profile changes. In this work, agar, alginates and carrageenan was irradiated as powder with different doses (0-10 kGy) of Co-60 and the rheological functional performance of water solutions of these irradiated additives was studied. The results are analyzed taking in account the future applications of those additives in irradiated foods. (author)

Radiation effects on agar, alginates and carrageenan to be used as food additives

Energy Technology Data Exchange (ETDEWEB)

Aliste, A.J. E-mail: nlmastro@net.ipen.br; Vieira, F.F.; Mastro, N.L. del

2000-03-01

Agar, alginates and carrageenan are hydrocolloids that induce stabilization of physical properties of the food product during shelf life and prevention of undesirable changes such as moisture migration, gas cell coalescence or textural profile changes. In this work, agar, alginates and carrageenan was irradiated as powder with different doses (0-10 kGy) of Co-60 and the rheological functional performance of water solutions of these irradiated additives was studied. The results are analyzed taking in account the future applications of those additives in irradiated foods. (author)

Effects of Astaxanthin from Litopenaeus Vannamei on Carrageenan-Induced Edema and Pain Behavior in Mice

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Zulkiflee Kuedo

2016-03-01

Full Text Available Carrageenan produces both inflammation and pain when injected in mouse paws via enhancement of reactive oxygen species formation. We have investigated an effect of astaxanthin extracted from Litopenaeus vannamei in carrageenan-induced mice paw edema and pain. The current study demonstrates interesting effects from astaxanthin treatment in mice: an inhibition of paw edema induced in hind paw, an increase in mechanical paw withdrawal threshold and thermal paw withdrawal latency, and a reduction in the amount of myeloperoxidase enzyme and lipid peroxidation products in the paw. Furthermore the effect was comparable to indomethacin, a standard treatment for inflammation symptoms. Due to adverse effects of indomethacin on cardiovascular and gastrointestinal systems, our study suggests promising prospect of astaxanthin extract as an anti-inflammatory alternative against carrageenan-induced paw edema and pain behavior.

Towards the Synthesis of Diverse Types of Carrageenan Oligosaccharides

DEFF Research Database (Denmark)

Kinnaert, Christine; Clausen, Mads Hartvig

Carrageenans are a family of linear sulfated polysaccharides that are extracted from red seaweeds.They play important roles in the biology of algae and furthermore they have many important industrial applications, such as gelling agent in the food industry. The idealized structures of the 10 known...

TPGS-Stabilized Curcumin Nanoparticles Exhibit Superior Effect on Carrageenan-Induced Inflammation in Wistar Rat

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Heni Rachmawati

2016-08-01

Full Text Available Curcumin, a hydrophobic polyphenol compound derived from the rhizome of the Curcuma genus, has a wide spectrum of biological and pharmacological applications. Previously, curcumin nanoparticles with different stabilizers had been produced successfully in order to enhance solubility and per oral absorption. In the present study, we tested the anti-inflammatory effect of d-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS-stabilized curcumin nanoparticles in vivo. Lambda-carrageenan (λ-carrageenan was used to induce inflammation in rats; it was given by an intraplantar route and intrapelurally through surgery in the pleurisy test. In the λ-carrageenan-induced edema model, TPGS-stabilized curcumin nanoparticles were given orally one hour before induction and at 0.5, 4.5, and 8.5 h after induction with two different doses (1.8 and 0.9 mg/kg body weight (BW. Sodium diclofenac with a dose of 4.5 mg/kg BW was used as a standard drug. A physical mixture of curcumin-TPGS was also used as a comparison with a higher dose of 60 mg/kg BW. The anti-inflammatory effect was assessed on the edema in the carrageenan-induced paw edema model and by the volume of exudate as well as the number of leukocytes reduced in the pleurisy test. TPGS-stabilized curcumin nanoparticles with lower doses showed better anti-inflammatory effects, indicating the greater absorption capability through the gastrointestinal tract.

Heavy metal accumulation by carrageenan and agar producing algae

Energy Technology Data Exchange (ETDEWEB)

Burdin, K.S. [Moscow State Univ. (Russian Federation). Faculty of Biology; Bird, K.T. [North Carolina Univ., Wilmington, NC (United States). Center for Marine Science Research

1994-09-01

The accumulation of six heavy metals Cu, Cd, Ni, Zn, Mn and Pb was measured in living and lzophilized algal thalli. The agar producing algae were Gracilaria tikvahiae and Gelidium pusillum. The carrageenan producing macroalgae were Agardhiella subulata and the gametophyte and tetrasporophyte phases of Chondrus crispus. These produce primarily iota, kappa and lambda carrageenans, respectively. At heavy metal concentrations of 0.5 mg L{sup -1}, living thalli of Gracilaria tikvahiae generally showed the greatest amount of accumulation of the 6 heavy metals tested. The accumulation of Pb was greater in the living thalli of all four species than in the lyophilized thalli. Except for Agardhiella subulata, lyophilized thalli showed greater accumulation of Ni, Cu and Zn. There was no difference in heavy metal accumulation between living and lyophilized thalli in the accumulation of Cd. Manganese showed no accumulation at the tested concentration. There did not appear to be a relationship between algal hydrocolloid characteristics and the amounts of heavy metals accumulated. (orig.)

Exposure to Common Food Additive Carrageenan Alone Leads to Fasting Hyperglycemia and in Combination with High Fat Diet Exacerbates Glucose Intolerance and Hyperlipidemia without Effect on Weight

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Sumit Bhattacharyya

2015-01-01

Full Text Available Aims. Major aims were to determine whether exposure to the commonly used food additive carrageenan could induce fasting hyperglycemia and could increase the effects of a high fat diet on glucose intolerance and dyslipidemia. Methods. C57BL/6J mice were exposed to either carrageenan, high fat diet, or the combination of high fat diet and carrageenan, or untreated, for one year. Effects on fasting blood glucose, glucose tolerance, lipid parameters, weight, glycogen stores, and inflammation were compared. Results. Exposure to carrageenan led to glucose intolerance by six days and produced elevated fasting blood glucose by 23 weeks. Effects of carrageenan on glucose tolerance were more severe than from high fat alone. Carrageenan in combination with high fat produced earlier onset of fasting hyperglycemia and higher glucose levels in glucose tolerance tests and exacerbated dyslipidemia. In contrast to high fat, carrageenan did not lead to weight gain. In hyperinsulinemic, euglycemic clamp studies, the carrageenan-exposed mice had higher early glucose levels and lower glucose infusion rate and longer interval to achieve the steady-state. Conclusions. Carrageenan in the Western diet may contribute to the development of diabetes and the effects of high fat consumption. Carrageenan may be useful as a nonobese model of diabetes in the mouse.

Utilization of cross-linked carboxymethyl κ-carrageenan as adsorbent for hexavalent chromium (Cr+6) ion

International Nuclear Information System (INIS)

Antonio, Princess Joyce R.; Punzalan, Mark Emile H.; Saturno, Rochelle Anne B.; Bayquen, Aristea V.

2009-01-01

The sorption behavior of cross-linked carboxymethyl κ-carrageenan as an alternative adsorbent for hexavalent chromium was studies. The κ-carrageenan had been carboxymethylated three times with 40% NaOH and monochloroacetic acid (MCA) in 80% isopropyl alcohol at 40 0 C. Carboxymethylated κ-carrageenan was crosslinked using Co 60 irradiation facility at PNRI. Batch experiments were conducted using prepared stock solution of Cr 6+ (70 ppm) under different sorption parameters at room temperature. These parameters include effects of pH, initial metal ion concentration, and contact time. Carboxymethylation and cross-linking was successfully achieved under optimum parameters. It was observed that cross-linked carboxymethyl κ-carrageenan best adsorbs chromium (VI) ion at pH 6, removing 41.59% of the metal ions present in the solution. Freundlich isotherm gave the highest correlation, R 2 , which is equal to 0.9880. This suggests the existence of mutilayer adsorption of the hexavalent chromium ions. Maximum adsorption was found to be at contact time of 2.5 hours and the concentration of the solution remains almost constant after 5 hours. The adsorption kinetics could be approximated favorably by the Lagergren pseudo-second-order kinetic model giving a correlation, R 2 , of 0.9985 and adsorption capacity, qmax, equal to 27.88 mg g +1 . (author)

Preparation and Characterization of K-Carrageenan/Nanosilica Biocomposite Film

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Lokesh R. Rane

2014-01-01

Full Text Available The purpose of this study is to improve the performance properties of K-carrageenan (K-CRG by utilizing nanosilica (NSI as the reinforcing agent. The composite films were prepared by solution casting method. NSI was added up to 1.5% in the K-CRG matrix. The prepared films were characterized for mechanical (tensile strength, tensile modulus, and elongation at break, thermal (differential scanning calorimetry, thermogravimetric analysis, barrier (water vapour transmission rate, morphological (scanning electron microscopy, contact angle, and crystallinity properties. Tensile strength, tensile modulus, and crystallinity were found to have increased by 13.8, 15, and 48% whereas water vapour transmission rate was found to have decreased by 48% for 0.5% NSI loaded K-CRG composite films. NSI was found to have formed aggregates for concentrations above 0.5% as confirmed by scanning electron microscopy. Melting temperature, enthalpy of melting, and degradation temperature of K-CRG increased with increase in concentration of NSI in K-CRG. Contact angle also increased with increase in concentration of NSI in K-CRG, indicating the decrease in hydrophilicity of the films improving its water resistance properties. This knowledge of the composite film could make beneficial contributions to the food and pharmaceutical packaging applications.

Semi-commercialization of PVP-carrageenan hydrogel

International Nuclear Information System (INIS)

Relleve, Lorna S.; Abad, Lucille V.; Aranilla, Charito T.; Dela Rosa, A.M.

2008-01-01

The Philippine Nuclear Research Institute (PNRI) has developed the PVP-Carrageenan hydrogel wound dressing by radiation processing. The PVP-Carrageenan hydrogel has undergone clinical testing for burn and bedsores. It has already a pending patent application (No. 1-2000-02471) at the Philippine Patent Office. The techno-economic feasibility study has also been completed. In order to commercialize this product, a project on semi-commercialization in partnership with the investor was proposed to Technology Incubation for Commercialization (TECHNICOM), a technology transfer program of the Department of Science and Technology (DOST). TECHNICOM was established in 2003 under the National Science and Technology Plan (2002-2020) as a strategic technology transfer program. The program aims to identify key technological breakthroughs especially those generated by R and D institutes. It can intervene through the following: technology assessment/commercial prototype development; business plan/feasibility study preparation; intellectual property rights protection; technology valuation negotiation and licensing; semi-commercial production assistance and training/consultancy services. High technology applications with commercial potentials are given priority. Under semi-commercialization stage, government funds will be provided to match private sector investment in the commercial application of a particular technology innovation. This will lessen the risk of commercialization and ensure commitment from the investors. Commercial success in the shortest time is ensured since scientist can then work closely with the private sector at the production floor while testing the gaps in the technology. (author)

Controlling of degradation effects in radiation processing of polymers. Second RCM report

International Nuclear Information System (INIS)

2005-08-01

The research and development works carried out by the participants of the CRP (Coordinated Research Project) dealt with natural polymers, synthetic polymers and new techniques for better understanding of radiation degradation of polymers. It includes progress in radiation degradation of polysaccharides from agricultural products (including sodium alginate, carrageenans, chitosan and gum acacia); use of radiation-degradation for doping of conductive polymers; controlling degradation processes in artificial joint implants, surface treatment of materials and food packaging; stabilizer additives for radiation environments; surface treatment of materials; and application of specialized analytical techniques (positron annihilation spectroscopy, ESR, RBS, ERDA, NMR/isotopic-labeling) to gain improved understanding of radiation degradation effects and mechanisms. Projects within the RCM group span the spectrum from fundamental studies through specific technological applications. Participants from Czech Republic, Spain and Turkey benefited from scientific collaboration with Bulgaria on PAS

The Use of Radiation-Induced Degradation in Controlling Molecular Weights of Polysaccharides : The Effect of Humidity

International Nuclear Information System (INIS)

Sen, M.

2006-01-01

Better understanding of chemistry of radiation-induced degradation is becoming of increasing importance on account of the utilization of polymeric materials in a variety of radiation environments as well as beneficial uses of degraded polymers. It is very well known that polysaccharides in dry form or in solution degrade when exposed to ionizing radiation. In this study degrading effect of radiation has been considered from the point of view of controlling the molecular weights of kappa- and iota-carrageenans and sodium alginate irradiated under varying environmental conditions. The humidity equilibrated polymer samples kept over saturated aqueous salt solutions of NaCl, NaNO 3 and MgCl 2 were irradiated in a Gammacell 220 at room temperature. The degradation was investigated in detail by a careful Gel Permeation Chromatographic analysis of their respective molecular weights before and after irradiation Alexander-Charlesby-Ross equation was used in determining their radiation-chemical yields. Degradation yield is the highest for dry irradiated kappa- (G(S) = 0.73) and iota-carrageenans (G(S) = 2.43) and with small amount of water taken up from surrounding humidity degradation becomes less pronounced and G(S) values show a decrease down to G(S) = 0.16 and 0.87 at 75 % relative humidity, respectively. At very high water contents degradation effect again becomes more effective. Sodium alginate has fount to be less sensitive to the effect of humidity. When there is small amount of water in the polysaccharide structure, it is unlikely to expect an indirect effect of radiation. The water located in between the polymer chains however can give enough mobility to kappa and iota karrageenans chains, plastifying effect, which may enhance the radical-radical combinations thus lowering the rate of degradation hence reducing G(S) values

Influence of lambda-carrageenan on the release of systematic series of volatile flavor compounds from viscous food model systems

DEFF Research Database (Denmark)

Bylaite, Egle; Ilgunaite, Z.; Meyer, Anne Boye Strunge

2004-01-01

-liquid partition coefficients K (37degreesC) of a total of 43 aroma compounds were determined in pure water and in the lambda-carrageenan solutions by static headspace gas chromatography. Mass transfer of the aroma compounds in water and in the thickened lambda-carrageenan solutions which had a wide viscosity...... range was assessed by dynamic headspace gas chromatography. K(37degreesC) increased as the carbon chain increased within each homologous series. Esters exhibited the highest volatility, followed by aldehydes, ketones, and alcohols. Under equilibrium, no overall effect of lambda-carrageenan was found...

Facial synthesis of carrageenan/reduced graphene oxide/Ag composite as efficient SERS platform

Energy Technology Data Exchange (ETDEWEB)

Zheng, Yuhong; Wang, Zhong; Fu, Li; Peng, Feng, E-mail: yuhongzhengcas@gmail.com [Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing (China); Wang, Aiwu [Department of Physics and Materials Science, City University of Hong (Hong Kong)

2017-01-15

In this paper, we reported the preparation of carrageenan/reduced graphene oxide/Ag composite (CA-RGO-Ag) by a wet chemical method at room temperature using carrageenan, graphene oxide and silver nitrate as starting materials. As-prepared composite was characterized by UV-vis spectroscopy, Raman spectroscopy, FTIR, SEM, EDX and XRD. Results showed that the reduction of graphene oxide (GO) and silver nitrate was achieved simultaneously by addition of NaBH{sub 4} . Surface-enhanced Raman scattering study showed that the obtained composite give an intensive and enhanced Raman scattering when Rhodamine B was used as a probing molecule. (author)

CHARACTERISTICS OF INTERACTIONS BETWEEN SOME TEXTURE PROPERTIES AND COMPOSITION OF CARRAGEENAN GELS AS A RESULT OF ITS DEFINED DIVERSIFIED FREEZING AND THAWING TREATMENT

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Katarzyna Kozłowicz

2013-06-01

Full Text Available Model samples of carrageenan gels based on water, milk and juice were air-blast frozen and frozen by immersion in glycol and in liquid nitrogen. The gel freezing rate was determined on the basis of the kinetics of freezing. Carrageenan gel samples were characterized by evaluation of its thawing drip loss and hardness determined with compression and penetration tests. Freezing in liquid nitrogen ensured the highest freezing rates. Thawing drip loss of gels significantly depended on the carrageenan content, pH of the solution, freezing method and freezing rate. The resulting relationships are linear functions with high determination coefficients. The results of compression and penetration tests prove the significant effect of the carrageenan content and pH on gel hardness. The higher carrageenan content in a sample, the higher compression force and penetration of the gel. Gel freezing resulted in lower hardness. Freezing conditions had a significant effect on the properties tested. The correlation between compression forces and penetration depending on the carrageenan content and the freezing method was described using regression equations with high determination coefficients. Gels based on milk and juice with 2.2% carrageenan content are recommended for immersion freezing at rates above 5.0 cm·h-1.

Antispasmodic and anti-inflammatory activity of Carrageenan from Hypnea musciformis Wulfen

Digital Repository Service at National Institute of Oceanography (India)

Solimabi; Das, B.

Pharmacological studies on K-carrageenan extracted from Hypnea musciformis have shown that it antagonizes histamine-induced spasm in guineapig ielum and possesses anti-inflammatory activity against rat hind paw oedema induced by commercial...

Lessons learned from a double-blind randomised placebo-controlled study with a iota-carrageenan nasal spray as medical device in children with acute symptoms of common cold.

Science.gov (United States)

Fazekas, Tamas; Eickhoff, Philipp; Pruckner, Nathalie; Vollnhofer, Georg; Fischmeister, Gustav; Diakos, Christopher; Rauch, Margit; Verdianz, Maria; Zoubek, Andreas; Gadner, Helmut; Lion, Thomas

2012-09-05

Common cold is caused by a variety of respiratory viruses. The prevalence in children is high, and it potentially contributes to significant morbidity. Iota-carragenan, a polymer derived from red seaweed, has reduced viral load in nasal secretions and alleviated symptoms in adults with common cold. We have assessed the antiviral and therapeutic activity of a nasal spray containing iota-carrageenan in children with acute symptoms of common cold. A cohort of 153 children between 1-18 years (mean age 5 years), displaying acute symptoms of common cold were randomly assigned to treatment with a nasal spray containing iota-carrageenan (0.12%) as verum or 0.9% sodium chloride solution as placebo for seven days. Symptoms of common cold were recorded and the viral load of respiratory viruses in nasal secretions was determined at two consecutive visits. The results of the present study showed no significant difference between the iota carrageenan and the placebo group on the mean of TSS between study days 2-7. Secondary endpoints, such as reduced time to clearance of disease (7.6 vs 9.4 days; p = 0.038), reduction of viral load (p = 0.026), and lower incidence of secondary infections with other respiratory viruses (p = 0.046) indicated beneficial effects of iota-carrageenan in this population. The treatment was safe and well tolerated, with less side effects observed in the verum group compared to placebo. In this study iota-carrageenan did not alleviate symptoms in children with acute symptoms of common cold, but significantly reduced viral load in nasal secretions that may have important implications for future studies. ISRCTN52519535, http://www.controlled-trials.com/ISRCTN52519535/

Gelam honey attenuates carrageenan-induced rat paw inflammation via NF-κB pathway.

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Saba Zuhair Hussein

Full Text Available The activation of nuclear factor kappa B (NF-κB plays a major role in the pathogenesis of a number of inflammatory diseases. In this study, we investigated the anti-inflammatory mechanism of Gelam honey in inflammation induced rats via NF-κB signalling pathway. Rats paw edema was induced by subplantar injection of 1% carrageenan into the right hind paw. Rats were pre-treated with Gelam honey at different doses (1 or 2 g/kg, p.o. and NSAID Indomethacin (10 mg/kg, p.o., in two time points (1 and 7 days. Our results showed that Gelam honey at both concentrations suppressed the gene expressions of NF-κB (p65 & p50 and IκBα in inflamed rats paw tissues. In addition, Gelam honey inhibited the nuclear translocation and activation of NF-κB and decreased the cytosolic degradation of IκBα dose dependently in inflamed rats paw tissues. The immunohistochemical expressions of pro-inflammatory mediators COX-2 and TNF-α were also decreased in inflamed rats paw tissues when treated with Gelam honey. The results of our findings suggest that Gelam honey exhibits its inhibitory effects by attenuating NF-κB translocation to the nucleus and inhibiting IκBα degradation, with subsequent decrease of inflammatory mediators COX-2 and TNF-α.

some causes and strategies pertaining to land degradation in ...

African Journals Online (AJOL)

Against the above background, this article outlines some of the social causes of land resource degradation in ... growing human numbers increase the pressure on available resources – a situation that is bound to ..... women to gain the degree of equality commensurate with their responsibility for social well-being and the ...

Physicochemical data on aqueous polymeric systems of methyl cellulose and lambda- and kappa-carrageenan: SAXS, rheological, densitometry, and sound velocity measurements

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Jure Cerar

2017-12-01

Full Text Available General as well as more specific physicochemical data obtained by studying the structure and various dynamical properties of aqueous polymer systems of methyl cellulose, λ−carrageenan, and κ−carrageenan are presented in graphical and numeric tabular form. The data provide basic polymer characterization info as also a specific structural and dynamical info for aqueous solutions of three industrially very important polymers (food additives that are available commercially. The commercial availability has much bigger impact to applications, research and connected advances, when the basic substances are well characterized – a feature that is still missing for many commercially available polymers unfortunately. Keywords: Food-grade polymers, Basic polymer characterization, Methyl cellulose, kappa-Carrageenan, lambda-Carrageenan

Thermal degradation kinetics of phycocyanin encapsulation as an antioxidant agent

Science.gov (United States)

Nilamsari, A. M.; Yunanda, A.; Hadiyanto, H.

2018-01-01

Phycocyanin is a blue-light pigment that found in Cyanobacteria and two Eukaryotics algae such as Rhodophyta and Crytophyta. Phycocyanin is soluble in water and has a strong fluorescent properties as an antioxidant and normally used in food industry, cosmetic, biotechnology, and drug. However, Phycocyanin is easily damaged by a heating process. The aim of this study is to obtain the optimal condition of phycocyanin encapsulation with different coating materials, Chitosan and Carrageenan, by the calculation of heat resistance of antioxidant activity (D), range of temperature that increase the rate of degradation (Z), rate constant of degradation (k), and activation energy (Ea). The ratio of phycocyanin and the coating material are 2% (w/v) and 2 % (w/v).

Evaluation of the swelling behaviour of iota-carrageenan in monolithic matrix tablets.

Science.gov (United States)

Kelemen, András; Buchholcz, Gyula; Sovány, Tamás; Pintye-Hódi, Klára

2015-08-10

The swelling properties of monolithic matrix tablets containing iota-carrageenan were studied at different pH values, with measurements of the swelling force and characterization of the profile of the swelling curve. The swelling force meter was linked to a PC by an RS232 cable and the measured data were evaluated with self-developed software. The monitor displayed the swelling force vs. time curve with the important parameters, which could be fitted with an Analysis menu. In the case of iota-carrageenan matrix tablets, it was concluded that the pH and the pressure did not influence the swelling process, and the first section of the swelling curve could be fitted by the Korsmeyer-Peppas equation. Copyright © 2015 Elsevier B.V. All rights reserved.

UV-screening, transparency and water barrier properties of semi refined iota carrageenan packaging film incorporated with ZnO nanoparticles

Science.gov (United States)

Khoirunnisa, Assifa Rahma; Joni, I. Made; Panatarani, Camellia; Rochima, Emma; Praseptiangga, Danar

2018-02-01

This study aims to develop film for food packaging application with high UV-screening, transparency and water barrier properties. Semi refined iota carrageenan (SRiC) nanocomposite films prepared by addition of zinc oxide (ZnO) nanoparticles as nanofiller using solution casting method. The effect of nanofiller with different concentration (0%, 0.5%, 1.0%, 1.5% w/w carrageenan) on UV-screening, transparency and water barrier properties of films were tested. The water barrier properties of the films were studied by measuring water vapor permeability (WVP) and the optical properties of the films were studied by using UV-Vis spectrophotometer at 280 nm for UV-screening test and at 660 nm for transparency test. WVP value of carrageenan films with addition of ZnO is low compared to a control carrageenan film and the lowest WVP value was found for the film with addition of 1.5% of ZnO. These result indicate that the addition of ZnO had a positive effect on the water barrier properties of the carrageenan matrix. Increase in the concentration of nanofiller leads to an increase in the UV-screening properties. Among all the films, carrageenan film with 1.5% ZnO has the highest UV-screening. The result showed that adding 0.5% and 1.0% of ZnO was insignificantly affect transparency of the films, however the transparency decreased sligthly when 1.5% ZnO was added. In conclusion, incorporating no more than 1.0% of ZnO to the films can obtain films with high UV-screening, transparency and water barrier properties and suitable for food packaging application.

Chemical analysis and biorefinery of red algae Kappaphycus alvarezii for efficient production of glucose from residue of carrageenan extraction process.

Science.gov (United States)

Masarin, Fernando; Cedeno, Fernando Roberto Paz; Chavez, Eddyn Gabriel Solorzano; de Oliveira, Levi Ezequiel; Gelli, Valéria Cress; Monti, Rubens

2016-01-01

Biorefineries serve to efficiently utilize biomass and their by-products. Algal biorefineries are designed to generate bioproducts for commercial use. Due to the high carbohydrate content of algal biomass, biorefinery to generate biofuels, such as bioethanol, is of great interest. Carrageenan is a predominant polysaccharide hydrocolloid found in red macroalgae and is widely used in food, cosmetics, and pharmaceuticals. In this study, we report the biorefinery of carrageenan derived from processing of experimental strains of the red macroalgae Kappaphycus alvarezii. Specifically, the chemical composition and enzymatic hydrolysis of the residue produced from carrageenan extraction were evaluated to determine the conditions for efficient generation of carbohydrate bioproducts. The productivity and growth rates of K. alvarezii strains were assessed along with the chemical composition (total carbohydrates, ash, sulfate groups, proteins, insoluble aromatics, galacturonic acid, and lipids) of each strain. Two strains, brown and red, were selected based on their high growth rates and productivity and were treated with 6 % KOH for extraction of carrageenan. The yields of biomass from treatment with 6 % KOH solution of the brown and red strains were 89.3 and 89.5 %, respectively. The yields of carrageenan and its residue were 63.5 and 23 %, respectively, for the brown strain and 60 and 27.8 %, respectively, for the red strain. The residues from the brown and red strains were assessed to detect any potential bioproducts. The galactan, ash, protein, insoluble aromatics, and sulfate groups of the residue were reduced to comparable extents for the two strains. However, KOH treatment did not reduce the content of glucan in the residue from either strain. Glucose was produced by enzymatic hydrolysis for 72 h using both strains. The glucan conversion was 100 % for both strains, and the concentrations of glucose from the brown and red strains were 13.7 and 11.5 g L(-1

Lessons learned from a double-blind randomised placebo-controlled study with a iota-carrageenan nasal spray as medical device in children with acute symptoms of common cold

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Fazekas Tamas

2012-09-01

Full Text Available Abstract Background Common cold is caused by a variety of respiratory viruses. The prevalence in children is high, and it potentially contributes to significant morbidity. Iota-carragenan, a polymer derived from red seaweed, has reduced viral load in nasal secretions and alleviated symptoms in adults with common cold. Methods We have assessed the antiviral and therapeutic activity of a nasal spray containing iota-carrageenan in children with acute symptoms of common cold. A cohort of 153 children between 1–18 years (mean age 5 years, displaying acute symptoms of common cold were randomly assigned to treatment with a nasal spray containing iota-carrageenan (0.12% as verum or 0.9% sodium chloride solution as placebo for seven days. Symptoms of common cold were recorded and the viral load of respiratory viruses in nasal secretions was determined at two consecutive visits. Results The results of the present study showed no significant difference between the iota carrageenan and the placebo group on the mean of TSS between study days 2–7. Secondary endpoints, such as reduced time to clearance of disease (7.6 vs 9.4 days; p = 0.038, reduction of viral load (p = 0.026, and lower incidence of secondary infections with other respiratory viruses (p = 0.046 indicated beneficial effects of iota-carrageenan in this population. The treatment was safe and well tolerated, with less side effects observed in the verum group compared to placebo. Conclusion In this study iota-carrageenan did not alleviate symptoms in children with acute symptoms of common cold, but significantly reduced viral load in nasal secretions that may have important implications for future studies. Trial registration ISRCTN52519535, http://www.controlled-trials.com/ISRCTN52519535/

Landscape degradation at different spatial scales caused by aridification

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Meyer Burghard Christian

2017-12-01

Full Text Available Landscape responses to degradation caused by aridification bring the landscape system into a new equilibrium state. The system transformation may entail irreversible changes to its constituting parameters. This paper analyses the impact of aridification on landscape degradation processes in the sand-covered landscapes of the Hungarian Danube-Tisza Interfluve region at the regional, landscape, and local site scales. Changes in groundwater level (well data, lake surface area (Modified Normalized Difference Water Index and vegetation cover (Enhanced Vegetation Index were analysed over time periods of 12–60 years. Significant regional variation in decreasing groundwater levels is observed and limits the regional applicability of this indicator. Applying the lake surface area parameter from remote sensing data demonstrated greater utility, identifying several local lakes in the landscapes which have dried out. Analysis of the vegetation response indicated minor changes over the 2000–2014 time period and did not indicate a landscape system change. Landscape degradation as a result of changes in groundwater, vegetation, land cover and land use is clearly identified exclusively in local lake areas, but at the landscape scale, changes in the water balance are found in phases of system stability and transformation. Thresholds are identified to support policy and management towards landscape degradation neutrality.

Conservation of Williams pear using edible coating with alginate and carrageenan

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Kessiane Silva de Moraes

2012-12-01

Full Text Available The aim of this study was to evaluate the physical and chemical parameters of Williams pear, stored at 25 ºC for 15 days, with and without edible coating. Edible coatings prepared with alginate 2% and carrageenan 0.5% were tested. The analyses carried out on the samples were: weight loss, pH, soluble solids, firmness, and color. The edible coatings were characterized in terms of mechanical properties, permeability, thickness, and opacity. The results show that the application of edible coatings with carrageenan and alginate in pears influenced physical and chemical characteristics such as weight loss, pH, total soluble solids, color, and firmness of the fruit. However, the alginate coating showed the best results on pear conservation since it had lower water vapor permeability and greater tensile strength, and therefore it can be used as a protective film on these fruits.

Anti-Inflammatory Activity of Lactobacillus on Carrageenan-Induced Paw Edema in Male Wistar Rats

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Sarika Amdekar

2012-01-01

Full Text Available Introduction. Lactobacillus casei and Lactobacillus acidophilus were used to assess the anti-inflammatory properties in carrageenan induced acute inflammatory model. Materials and Methods. Diclofenac sodium was used as standard drug at concentration of 150 mg/kg of body weight. Culture of Lactobacillus  2×107 CFU/ml was given orally. Edema was induced with 1% carrageenan to all the groups after one hour of the oral treatments. Paw thickness was checked at =1, 2, 3, 4, 5, and 24 hours. Stair climbing score and motility score were assessed at =24 hours. Cytokines assay for IL-6, IL-10, and TNF-α was performed on serum samples. Results. Lactobacillus showed a statistically significant decrease in paw thickness at <0.001. L. acidophilus and L. casei decreased by 32% and 28% in paw thickness. They both significantly increased the stair climbing and motility score. Lactobacillus treatment significantly downregulated IL-6 and TNF-α while upregulated IL-10 at <0.0001. Conclusion. L. casei and L. acidophilus significantly decreased the inflammatory reactions induced by carrageenan. This study has also proposed that Lactobacillus ameliorated the inflammatory reaction by downregulating the proinflammatory cytokines pathway.

Depolymerized products of lambda-carrageenan as a potent angiogenesis inhibitor.

Science.gov (United States)

Chen, Haimin; Yan, Xiaojun; Lin, Jing; Wang, Feng; Xu, Weifeng

2007-08-22

Since angiogenesis is involved in initiating and promoting several diseases such as cancer and cardiovascular events, this study was designed to evaluate the anti-angiogenesis of low-molecular-weight (LMW), highly sulfated lambda-carrageenan oligosaccharides (lambda-CO) obtained by carrageenan depolymerization, by CAM (chick chorioallantoic membrane) model and human umbilical vein endothelial cells (HUVECs). Significant inhibition of vessel growth was observed at 200 microg/pellet. A histochemistry assay also revealed a decrease of capillary plexus and connective tissue in lambda-CO treated samples. lambda-CO inhibited the viability of cells at the high concentration of 1 mg/mL, whereas it affected the cell survival slightly (>95%) at a low concentration (lambda-CO among three kinds of cells. Furthermore, the inhibitory action of lambda-CO was also observed in the endothelial cell invasion and migration at relatively low concentration (150-300 microg/mL), through down-regulation of intracellular matrix metalloproteinases (MMP-2) expression on endothelial cells. Taken together, these findings demonstrate that lambda-CO is a potential angiogenesis inhibitor with combined effects of inhibiting invasion, migration, and proliferation.

Water chemistry: cause and control of corrosion degradation in nuclear power plants

International Nuclear Information System (INIS)

Kain, Vivekanand

2008-01-01

The corrosion degradation of a material is directly determined by the water chemistry, material (composition, fabrication procedure and microstructure) and by the stress/strain in the material under operating conditions. Water chemistry plays an important role in both uniform corrosion and localized forms of corrosion of materials. Once we understand how water chemistry is contributing to corrosion of a material, it is logical to modify/change that water chemistry to control the corrosion degradation. In nuclear power plants, different water chemistries have been used in different components/systems. This paper will cover the origin of corrosion degradation in the Primary Heat Transport system of different reactor types, Steam Generator tubing, secondary circuit pipelines, service water pipelines and auxiliary systems and establish the role of water chemistry in causing corrosion degradation. The history of changes in water chemistry adopted in these systems to control corrosion degradation is also described. It is shown by examples that there is an obvious limitation in changing water chemistry to control corrosion degradation and in those cases, a change of material or change of the state of stresses/fabrication procedure becomes necessary. The role of water chemistry as a causative factor and also as a controlling parameter on particular types of corrosion degradation e.g. stress corrosion cracking, flow accelerated corrosion, pitting, crevice corrosion is illustrated. It will be shown that increase in dissolved oxygen content (due to radiolysis in nuclear reactors) is sufficient to make even the de-mineralized water to cause stress corrosion cracking in Boiling Water Reactors. Hydrogen Water Chemistry (by hydrogen injection) to control dissolved oxygen is shown to control the stress corrosion cracking. However, it is not possible to control dissolved oxygen at all parts of the Boiling Water Reactors. Therefore, a further refinement in terms of noble metal

Hydrophobic lappaconitine loaded into iota-carrageenan by one step self-assembly.

Science.gov (United States)

Sun, Wenxiu; Saldaña, Marleny D A; Zhao, Yujia; Wu, Lingling; Dong, Tungalag; Jin, Ye; Zhang, Ji

2016-02-10

New data on the loading of pH-sensitive lappaconitine loaded into iota-carrageenan (LA-ICG) is provided. This LA-ICG ionic biopolymer was prepared by one step self-assembly. The LA-ICG was characterized in terms of the loading capacity, lappaconitine (LA) releasing behavior, pH-sensitivity, and analgesic properties. Iota-carrageenan (ICG) high loading capacity reached up to 26.18% (w/w). Also, the LA, loaded with ICG, was released faster in an acidic environment than that in neutral or alkaline environments. Animal analgesic experiments showed that the LA-ICG of low molecular weight had earlier onset time and longer duration than the LA. These results suggest that the ICG of low molecular weight has great potential to achieve the synergistic effect of LA. In addition, the ICG can be used as a novel natural polymeric carrier for loading a hydrophobic alkaloid. Copyright © 2015 Elsevier Ltd. All rights reserved.

Micro-mesoporous carbon spheres derived from carrageenan as electrode material for supercapacitors

Science.gov (United States)

Fan, Yang; Yang, Xin; Zhu, Bing; Liu, Pei-Fang; Lu, Hai-Ting

2014-12-01

The polysaccharide carrageenan is used as a natural precursor to prepare micro-mesoporous carbon spheres. The carbon spheres were synthesized by hydrothermal carbonization of carrageenan, and subsequent chemical activation by KOH at different temperatures. The obtained micro-mesoporous carbon spheres have high surface area (up to 2502 m2 g-1) and large pore volume (up to 1.43 cm3 g-1). Moreover, the micro- and mesoporosity can be finely tuned be modifying the activation temperatures in the range of 700-900 °C. The carbon spheres activated at 900 °C present high specific capacitance of 230 F g-1 at a current density of 1 A g-1 and good ion transport kinetics. The good capacitive performance can be ascribed to the high specific surface area, well-controlled micro- and mesoporosity and narrow pore size distribution.

κ-Carrageenan Enhances Lipopolysaccharide-Induced Interleukin-8 Secretion by Stimulating the Bcl10-NF-κB Pathway in HT-29 Cells and Aggravates C. freundii-Induced Inflammation in Mice

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Wei Wu

2017-01-01

Full Text Available Background. The dietary usage of carrageenan as common food additive has increased observably over the last 50 years. But there is substantial controversy about its safety. Methods. We investigated whether the κ-carrageenan could enhance lipopolysaccharide-induced IL-8 expression by studying its actions on the TLR4-NF-κB pathway. The aggravating effect of κ-carrageenan on Citrobacter freundii DBS100-induced intestinal inflammation was also investigated in a mouse model. Results. Our data show that κ-carrageenan pretreatment promoted LPS-induced IL-8 expression in HT-29 cells. Although CD14, MD-2, and TLR4 were upregulated, the binding of LPS was not enhanced. However, the pathway of Bcl10-NF-κB was triggered. Interestingly, κ-carrageenan competitively blocked the binding of FITC-LPS. Furthermore, pretreatment with κ-carrageenan for one week previous to gavage with C. freundii DBS100 markedly aggravated weight loss, mortality, and colonic damage. The secretion of cytokines was unbalanced and the ratio of Tregs was decreased significantly. In addition, κ-carrageenan, together with C. freundii DBS100, enhanced the transcription and secretion of TLR4 and NF-κB. Conclusions. κ-Carrageenan can synergistically activate LPS-induced inflammatory through the Bcl10-NF-κB pathway, as indicated by its aggravation of C. freundii DBS100-induced colitis in mice. General Significance. Our results suggest that κ-carrageenan serves as a potential inflammatory agent that magnifies existing intestinal inflammation.

Food additive carrageenan: Part II: A critical review of carrageenan in vivo safety studies.

Science.gov (United States)

Weiner, Myra L

2014-03-01

Carrageenan (CGN) is a seaweed-derived high molecular weight (Mw) hydrocolloid, primarily used as a stabilizer and thickener in food. The safety of CGN regarding its use in food is reviewed. Based on experimental studies in animals, ingested CGN is excreted quantitatively in the feces. Studies have shown that CGN is not significantly degraded by low gastric pH or microflora in the gastrointestinal (GI) tract. Due to its Mw, structure and its stability when bound to protein, CGN is not significantly absorbed or metabolized. CGN also does not significantly affect the absorption of nutrients. Subchronic and chronic feeding studies in rodents indicate that CGN at doses up to 5% in the diet does not induce any toxicological effects other than soft stools or diarrhea, which are a common effect for non-digestible high molecular weight compounds. Review of several studies from numerous species indicates that food grade CGN does not produce intestinal ulceration at doses up to 5% in the diet. Effects of CGN on the immune system following parenteral administration are well known, but not relevant to food additive uses. The majority of the studies evaluating the immunotoxicity potential were conducted with CGN administered in drinking water or by oral gavage where CGN exists in a random, open structured molecular conformation, particularly the lambda form; hence, it has more exposure to the intestinal mucosa than when bound to protein in food. Based on the many animal subchronic and chronic toxicity studies, CGN has not been found to affect the immune system, as judged by lack of effects on organ histopathology, clinical chemistry, hematology, normal health, and the lack of target organ toxicities. In these studies, animals consumed CGN at orders of magnitude above levels of CGN in the human diet: ≥1000 mg/kg/d in animals compared to 18-40 mg/kg/d estimated in the human diet. Dietary CGN has been shown to lack carcinogenic, tumor promoter, genotoxic, developmental, and

Construction of biosensor systems for determining the pathophysiological potential of carrageenan variants

DEFF Research Database (Denmark)

Riedel, Angela; End, Caroline; Christiansen, Helle

2009-01-01

In vitro systems for monitoring safety of nutritional additives are desirable for high-throughput screenings and as a substitute for animal models. Carrageenan (CGN) is a sulfated polysaccharide widely used as a thickener and texturizer in human nutrition and is intensely discussed regarding its...

Efficacy and safety of an antiviral Iota-Carrageenan nasal spray: a randomized, double-blind, placebo-controlled exploratory study in volunteers with early symptoms of the common cold

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Weinmüllner Regina

2010-08-01

Full Text Available Abstract Background The common cold, the most prevalent contagious viral disease in humans still lacks a safe and effective antiviral treatment. Iota-Carrageenan is broadly active against respiratory viruses in-vitro and has an excellent safety profile. This study investigated the efficacy and safety of an Iota-Carrageenan nasal spray in patients with common cold symptoms. Methods In a randomized, double-blind, placebo-controlled exploratory trial, 35 human subjects suffering from early symptoms of common cold received Iota-Carrageenan (0.12% in a saline solution three times daily for 4 days, compared to placebo. Results Administration of Iota-Carrageenan nasal spray reduced the symptoms of common cold (p = 0.046 and the viral load in nasal lavages (p = 0.009 in patients with early symptoms of common cold. Pro-inflammatory mediators FGF-2, Fractalkine, GRO, G-CSF, IL-8, IL-1α, IP-10, IL-10, and IFN-α2 were reduced in the Iota-Carrageenan group. Conclusions Iota-Carrageenan nasal spray appears to be a promising treatment for safe and effective treatment of early symptoms of common cold. Larger trials are indicated to confirm the results.

Effect of process conditions on the gel viscosity and gel strength of semi-refined carrageenan (SRC produced from seaweed (Kappaphycus alvarezii

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Awang Bono

2014-01-01

Full Text Available Kappaphycus alvarezii or commonly known Euchema cottonii is a good source of kappa-carrageenan and can be found cultivated in the coastal areas of Malaysia, Philippines and Indonesia. Carrageenans have many applications and are utilized in human food and pet-food industry. Carrageenans are also utilized in non-food industry such as pharmaceuticals, cosmetics, printing and textile formulations. Currently, the Southeast Asian region is producing semi refined carrageenan (SRC. There are various works in producing SRC; however, there are limited efforts to develop the optimization of cooking process parameters. Hence, the present study features on the cooking process (alkaline treatment where the parameters (concentration of potassium hydroxide solution, cooking time and cooking temperature and the ranges are identified experimentally. The effects of these parameters on carrageenan quality such as gel viscosity and gel strength were studied. The optimization of cooking process parameters and the experimental design was conducted based on the Central Composite Design (CCD of Response Surface Methodology (RSM. The experimental result showed that gel viscosity increases with the decrease of cooking time, cooking temperature and potassium hydroxide (KOH concentration (% w/w. In contrast, gel strength increases as cooking time, cooking temperature and KOH concentration (% w/w increases. From the optimization, the best conditions for alkaline treatment found were cooking temperature 80 °C, cooking time 30 min and KOH concentration 10 (% w/w which are similar to current practice in industry.

Release-Active Dilutions of Diclofenac Enhance Anti-inflammatory Effect of Diclofenac in Carrageenan-Induced Rat Paw Edema Model

OpenAIRE

Sakat, Sachin S.; Mani, Kamaraj; Demidchenko, Yulia O.; Gorbunov, Evgeniy A.; Tarasov, Sergey A.; Mathur, Archna; Epstein, Oleg I.

2013-01-01

The study was aimed to investigate the effect of technologically treated diclofenac (release-active dilutions of diclofenac (RAD of diclofenac)) on anti-inflammatory activity of diclofenac in carrageenan-induced rat paw edema model. Ninety male Wistar albino rats (6–8 weeks) divided into nine groups (n = 10) were used. Anti-inflammatory activity was assessed at 1, 2, 3, 4, and 6 h after subplantar injection of carrageenan (0.1 ml of a 1 % solution in normal saline). Diclofenac alone was studi...

Effect of carrageenan addition on the yield and functional properties of charqui (Jerked Beef

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Carlos Eduardo Rocha Garcia

2013-04-01

Full Text Available The objective of this work was to evaluate the application of carrageenan (CAR to improve the functional properties of the jerked beef (JF and to increase its processing yield. JB produced from Vastus lateralis with CAR (1.0% at 25ºC and NaCl (15.0% had approximately 15.0% higher moisture and a 32.0% higher processing yield in comparison to the control samples.JB-CAR presented shear force approximately 5.0 and 20% lower in the samples uncooked salted and desalted cooked, respectively, and sensorial acceptance above 80%. The results demonstrated the possibility of applying carrageenan to jerked beef in order to obtain an increase in the processing yield and a tender product while maintaining the sensorial quality and its intermediate-moisture meat product nature.

Fasitibant chloride, a kinin B2 receptor antagonist, and dexamethasone interact to inhibit carrageenan-induced inflammatory arthritis in rats

Science.gov (United States)

Valenti, Claudio; Giuliani, Sandro; Cialdai, Cecilia; Tramontana, Manuela; Maggi, Carlo Alberto

2012-01-01

BACKGROUND AND PURPOSE Bradykinin, through the kinin B2 receptor, is involved in inflammatory processes related to arthropathies. B2 receptor antagonists inhibited carrageenan-induced arthritis in rats in synergy with anti-inflammatory steroids. The mechanism(s) underlying this drug interaction was investigated. EXPERIMENTAL APPROACH Drugs inhibiting inflammatory mediators released by carrageenan were injected, alone or in combination, into the knee joint of pentobarbital anaesthetized rats 30 min before intra-articular administration of carrageenan. Their effects on the carrageenan-induced inflammatory responses (joint pain, oedema and neutrophil recruitment) and release of inflammatory mediators (prostaglandins, IL-1β, IL-6 and the chemokine GRO/CINC-1), were assessed after 6 h. KEY RESULTS The combination of fasitibant chloride (MEN16132) and dexamethasone was more effective than each drug administered alone in inhibiting knee joint inflammation and release of inflammatory mediators. Fasitibant chloride, MK571, atenolol, des-Arg9-[Leu8]-bradykinin (B2 receptor, leukotriene, catecholamine and B1 receptor antagonists, respectively) and dexketoprofen (COX inhibitor), reduced joint pain and, except for the latter, also diminished joint oedema. A combination of drugs inhibiting joint pain (fasitibant chloride, des-Arg9-[Leu8]-bradykinin, dexketoprofen, MK571 and atenolol) and oedema (fasitibant chloride, des-Arg9-[Leu8]-bradykinin, MK571 and atenolol) abolished the respective inflammatory response, producing inhibition comparable with that achieved with the combination of fasitibant chloride and dexamethasone. MK571 alone was able to block neutrophil recruitment. CONCLUSIONS AND IMPLICATIONS Bradykinin-mediated inflammatory responses to intra-articular carrageenan were not controlled by steroids, which were not capable of preventing bradykinin effects either by direct activation of the B2 receptor, or through the indirect effects mediated by release of eicosanoids

PENGARUH KONSUMSI KAPPA-KARAGENAN TERHADAP GLUKOSA DARAH TIKUS WISTAR (Ratus norvegicus DIABETES [The Effect of Kappa-Carrageenan Consumption on Blood Glucose Level of Diabetic Wistar Rat (Ratus norwegicus

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Hardoko

2006-04-01

Full Text Available The effect of kappa-carrageenan consumption on blood glucose level were studied on diabetic male wistar rat (Ratus norvegicus.The rats were made diabetic by aloxan injection, and then were given that a ration contains 5, 10, 15, 20% (w/w kappa-carrageenan, standard ration (negative control, and parental glibenklamid (positive control. The results showed that the standard ration could not reduce blood glucose from hyperglycemic to normal level, while the ration contained kappacarrageenan could. The higher kappa-carrageenan seaweed level in the ration has higher capacity to decrease blood glucose level. The ration containing 20% and 15% kappa-carrageenan could reduce blood glucose in 18 and 21 days, respectively.The effect of this ration was similar to that of glibenklamid which reduced blood glucose to normal level in 18 days. The ration containing 5 and 10% kappa-carrageenan could reduce blood glucose level; Blood glucose leve return to normal on the 21st day.

Low-fat meat sausages with fish oil: optimization of milk proteins and carrageenan contents using response surface methodology.

Science.gov (United States)

Marchetti, L; Andrés, S C; Califano, A N

2014-03-01

Response surface methodology was used to analyze the effect of milk proteins and 2:1 κ:ι-carrageenans on cooking loss (CL), weight lost by centrifugation (WLC) and texture attributes of low-fat meat sausages with pre-emulsified fish oil. A central-composite design was used to develop models for the objective responses. Changes in carrageenans affected more the responses than milk proteins levels. Convenience functions were calculated for CL, WLC, hardness, and springiness of the product. Responses were optimized simultaneously minimizing CL and WLC; ranges for hardness and springiness corresponded to commercial products (20 g of pork fat/100 g). The optimum corresponded to 0.593 g of carrageenans/100 g and 0.320 g of milk proteins and its total lipid content was 6.3 g/100 g. This formulation was prepared and evaluated showing a good agreement between predicted and experimental responses. These additives could produce low-fat meat sausages with pre-emulsified fish oil with good nutritional quality and similar characteristics than traditional ones. Copyright © 2013 Elsevier Ltd. All rights reserved.

Drug Release Kinetics and Front Movement in Matrix Tablets Containing Diltiazem or Metoprolol/λ-Carrageenan Complexes

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Ruggero Bettini

2014-01-01

Full Text Available In this work we investigated the moving boundaries and the associated drug release kinetics in matrix tablets prepared with two complexes between λ-carrageenan and two soluble model drugs, namely, diltiazem HCl and metoprolol tartrate aiming at clarifying the role played by drug/polymer interaction on the water uptake, swelling, drug dissolution, and drug release performance of the matrix. The two studied complexes released the drug with different mechanism indicating two different drug/polymer interaction strengths. The comparison between the drug release behaviour of the complexes and the relevant physical mixtures indicates that diltiazem gave rise to a less soluble and more stable complex with carrageenan than metoprolol. The less stable metoprolol complex afforded an erodible matrix, whereas the stronger interaction between diltiazem and carrageenan resulted in a poorly soluble, slowly dissolving matrix. It was concluded that the different stability of the studied complexes affords two distinct drug delivery systems: in the case of MTP, the dissociation of the complex, as a consequence of the interaction with water, affords a classical soluble matrix type delivery system; in the case of DTZ, the dissolving/diffusing species is the complex itself because of the very strong interaction between the drug and the polymer.

Evaluation of stress-strain for characterization of the rheological behavior of alginate and carrageenan gels

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E.J. Mammarella

2002-12-01

Full Text Available The stress-strain of samples deformed until failure and the relaxation response after 50% deformation of the initial height under constant stress were obtained. Uniaxial compression and stress-relaxation tests enabled satisfactory differentiation of the mechanical resistance of gels with different alginate and carrageenan concentrations. Higher values for initial force at the beginning of the relaxation test were associated with higher calcium uptake by the gels. An increment of failure stress during the uniaxial compression tests for higher concentration of calcium in the gel structure was also observed. The maximum amount of cation uptake was higher than the theoretical value for saturation of all the carboxylic groups available in alginate molecules due to structural rearrangements. Stress-relaxation tests indicated that the residual stress of the gel increased with kappa-carrageenan concentration.

Mechanical and Barrier Properties of Semi Refined Kappa Carrageenan-based Composite Edible Film and Its Application on Minimally Processed Chicken Breast Fillet

Science.gov (United States)

Praseptiangga, D.; Maimuni, B. H.; Manuhara, G. J.; Muhammad, D. R. A.

2018-03-01

Kappa-carrageenan (KC) is one of the most interesting biopolymers that is composed of a linear chain of sulfated galactans and extracted from red seaweed, Kappaphycus alvarezii. It shows good potential for development as a source of biodegradable or edible films. However, KC films do not have good water vapor barrier properties, as they are intrinsically hydrophilic. Palmitic acid (PA) as hydrophobic material was incorporated into semi-refined kappa-carrageenan (SRKC) edible films in order to improve water vapor barrier properties. In this study, composite films based on SRKC incorporating PA were prepared and their applications on minimally processed chicken breast fillet were evaluated. Composite SRKC-based films with varying concentrations of PA (5%, 10%, and 15% w/w) were obtained by a solvent casting method. Their mechanical and barrier properties were investigated. Results showed that the incorporation of PA in films caused an increase in thickness, but decrease in water vapor transmission rate (WVTR) as the concentration of PA increased (from 5% to 15% w/w). Composite SRKC-based edible film incorporating 15% w/w of PA presented better water vapor barrier properties as compared to other films with 5% and 10% w/w PA incorporation. Thus, formulation containing 15% w/w PA was used as a wrapping material for film application on minimally processed chicken breast fillet. The application results showed that the incorporation of PA in film caused an effect (p 0.05) change the color of minimally processed chicken breast fillet.

Critical Causes of Degradation in Integrated Laboratory Scale Cells during High Temperature Electrolysis

Energy Technology Data Exchange (ETDEWEB)

M.S. Sohal; J.E. O' Brien; C.M. Stoots; J. J. Hartvigsen; D. Larsen; S. Elangovan; J.S. Herring; J.D. Carter; V.I. Sharma; B. Yildiz

2009-05-01

An ongoing project at Idaho National Laboratory involves generating hydrogen from steam using solid oxide electrolysis cells (SOEC). This report describes background information about SOECs, the Integrated Laboratory Scale (ILS) testing of solid-oxide electrolysis stacks, ILS performance degradation, and post-test examination of SOECs by various researchers. The ILS test was a 720- cell, three-module test comprised of 12 stacks of 60 cells each. A peak H2 production rate of 5.7 Nm3/hr was achieved. Initially, the module area-specific resistance ranged from 1.25 Ocm2 to just over 2 Ocm2. Total H2 production rate decreased from 5.7 Nm3/hr to a steady state value of 0.7 Nm3/hr. The decrease was primarily due to cell degradation. Post test examination by Ceramatec showed that the hydrogen electrode appeared to be in good condition. The oxygen evolution electrode does show delamination in operation and an apparent foreign layer deposited at the electrolyte interface. Post test examination by Argonne National Laboratory showed that the O2-electrode delaminated from the electrolyte near the edge. One possible reason for this delamination is excessive pressure buildup with high O2 flow in the over-sintered region. According to post test examination at the Massachusetts Institute of Technology, the electrochemical reactions have been recognized as one of the prevalent causes of their degradation. Specifically, two important degradation mechanisms were examined: (1) transport of Crcontaining species from steel interconnects into the oxygen electrode and LSC bond layers in SOECs, and (2) cation segregation and phase separation in the bond layer. INL conducted a workshop October 27, 2008 to discuss possible causes of degradation in a SOEC stack. Generally, it was agreed that the following are major degradation issues relating to SOECs: • Delamination of the O2-electrode and bond layer on the steam/O2-electrode side • Contaminants (Ni, Cr, Si, etc.) on reaction sites

Characterization and evaluation physical properties biodegradable plastic composite from seaweed (Eucheuma cottonii)

Science.gov (United States)

Deni, Glar Donia; Dhaningtyas, Shalihat Afifah; Fajar, Ibnu; Sudarno

2015-12-01

The characterization and evaluation of biodegradable plastic composed of a mixture PVA - carrageenan - chitosan was conducted in this study. Obtained data were then compared to commercial biodegradable plastic. Characteristic of plastic was mechanical tested such as tensile - strength and elongation. Plastic degradation was studied using composting method for 7 days and 14 days. The results showed that the increase carrageenan will decrease tensile-strength and elongation plastic composite. In addition, increase carrageenan would increase the degraded plastics composite.

Procyanidin B2 ameliorates carrageenan-induced chronic nonbacterial prostatitis in rats via anti-inflammatory and activation of the Nrf2 pathway.

Science.gov (United States)

Wang, Wei; Chen, Renzong; Wang, Jiye

2017-11-04

Prostatitis is one of the most prevalent problems in andriatry and urinary surgery. In the present study, we evaluated the effect of procyanidin B2 (PB) on carrageenan-induced chronic nonbacterial prostatitis in rats. Results showed that PB significantly decreased the prostatic index and enhanced the body weight inhibited by carrageenan. Biochemical results revealed that PB significantly lowered the prostatic specific antigen (PSA) and alleviated oxidative stress in serum. The levels of TNF-α, IL-6, and IL-10 in prostatic homogenate were also significantly decreased after PB treatment. We also found evidence that PB treatment reversed the suppression of Nrf2 nuclear translocation, and increased the expressions of NQO1 and HO-1 in the prostate glands. In conclusion, treatment with PB attenuates carrageenan-induced chronic nonbacterial prostatitis via anti-inflammatory and activation of the Nrf2 pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of tumbling time, injection rate and k-carrageenan addition on processing, textural and color characteristics of pork Biceps femoris muscle

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Livia PATRAŞCU

2013-08-01

Full Text Available The effect of tumbling time (0-9 hours, injection rate (20-50% and k carrageenan addition (0.25 - 0.5% on quality characteristics of cooked pork Biceps femoris muscle have been studied. Properties of injected and tumbled meat samples were determined by measuring processing characteristics (tumbling yield, cooking yield and expressible moisture, color (L*, a*, b*, Hue angle and Chroma and texture (firmness, toughness, adhesiveness, work of adhesion and fracturability. Increasing tumbling time up to 9 h led to better hydration properties and increased the cooking yield for all samples, both with 0.25% and 0.5% of k-carrageenan addition. It also decreased the firmness and toughness of the evaluated samples. Biceps femoris samples containing a higher level of k-carrageenan were tenderer than those containing less polysaccharide. Neither injection rate nor tumbling time affected the color components of the analyzed samples.

Optimization of formulation of cmc-na, xanthan gum and carrageenan affecting the physicochemical properties of papaya-wolfberry beverage using response surface methodology

International Nuclear Information System (INIS)

Geo, J.Z.H.; Zong, G.L.P.

2013-01-01

CMC-Na, xanthan gum and carrageenan are widely employed in food industry. They were used for its thickening properties of aqueous solutions or emulsifying abilities. The present work aims to optimize the formula of the three stabilizers in the process of papaya-wolfberry beverage by response surface methodology (RSM). The results showed that the models were significantly (p<0.05) fitted for describing the viscosity and cloudiness of papaya-wolfberry beverage. The results also indicated that the linear terms of CMC-Na and xanthan gum were the most significant (p<0.05) variables affecting the viscosity, while xanthan gum and carrageenan were the most significant (p<0.05) variable affecting the cloudiness. The interaction of CMC-Na and xanthan gum behaved extremely significant for viscosity. From the optimization procedure, the best formula for viscosity was obtained at the combined level of 0.0652% (w/w) CMC-Na, 0.1070% (w/w) xanthan gum and 0.1485% (w/w) carrageenan, and the other group of 0.0623% (w/w) CMC-Na, 0.1375% (w/w) xanthan gum and 0.1461% (w/w) carrageenan for cloudiness. The results of our study would be used to improve the quality of papaya-wolfberry beverage and increase its economic efficiency. (author)

Synthesis of superabsorbent hydrogel by radiation crosslinking of acrylic acid, semi-refined kappa-carrageenan and sugarcane bagasse blend

International Nuclear Information System (INIS)

Jizmundo, Leonie-Lou Dominguez

2015-04-01

Superabsorbent hydrogels have three-dimensional networks that enable it to exhibit great water absorption capacity leading to its promising applications. However, existing commercial hydrogels are mainly acrylic acid which causes environmental problems. In this study, the incorporation of agricultural waste as filler and polysaccharide from natural sources as binder for the production of superabsorbent hydrogel was done to reduce the use of acrylic acid as well as its environmental impact while adding value to the incorporated materials. A series of superabsorbent hydrogel with the blend of acrylic acid, semi-refined kappa carrageenan and sugarcane bagasse were synthesized by radiation crosslinking. The gel fraction and swelling capacity of the hydrogels were determined and studied. The characterizations were facilitated by Fourier transform infrared spectroscopy technique (FTIR) and Thermogravimetric Analysis (TGA). In the results obtained from analyses, the characteristic peaks of acrylic acid and sugarcane bagasse were observed in the FTIR spectra and the three step peaks if synthesized hydrogel in its TGA implies an improvement in thermal stability of the product. The synthesized superabsorbent hydrogel blends had exhibited comparable gel fraction to that of the polyacrylic acid hydrogel, had great swelling capacity, and achieved equilibrium degree of swelling within 72-96 hours. The optimum synthesized superabsorbent hydrogel is 3% semi-refined kappa-carrageenan, 3% sugarcane bagasse, 15% acrylic acid neutralize up to 50% and irradiated at 15kGy dose which exhibited a swelling of 599.53 and gel fraction of 39.73. (author)

Thrombolytic effects in vivo of nattokinase in a carrageenan-induced rat model of thrombosis.

Science.gov (United States)

Xu, Jianping; Du, Ming; Yang, Xiulin; Chen, Qingquan; Chen, Hong; Lin, Dong-Hong

2014-01-01

Nattokinase is a serine protease produced by Bacillus subtilis during the fermentation of the soybean product natto. The fibrinolytic activity and thrombolytic effects of nattokinase have been observed in vitro, but the effect in vivo has still to be researched. The objective of this study was to demonstrate the activity of nattokinase in vivo. To establish a rat model of thrombosis, κ-carrageenan was injected subcutaneously into the toes of Sprague-Dawley (SD) rats. Histological examination confirmed thrombosis. The rats were then treated with varying doses of nattokinase and the resulting thrombolysis was histologically assessed. ELISA was used to determine the levels of the fibrin/fibrinogen degradation products (FDPs) and D-dimer, which are sensitive indices of fibrinolytic activity. Vermis kinase, a known thrombolytic agent, was used as a positive control. Biopsy results revealed partial thrombolysis in the tail vessels of the rats treated with nattokinase or vermis kinase. FDP and D-dimer levels were higher in rats treated with high-dose nattokinase than in those treated with saline. No difference in FDP or D-dimer levels was observed between rats treated with high-dose nattokinase and those treated with vermis kinase. Both the histological and physiological evidence from this study indicate that nattokinase exerts thrombolytic effects in vivo.

Growth and substrate consumption of Nitrobacter agilis cells immobilized in carrageenan: part 1. Dynamic modeling.

Science.gov (United States)

de Gooijer, C D; Wijffels, R H; Tramper, J

1991-07-01

The modeling of the growth of Nitrobacter agilis cell immobilized in kappa-carrageenan is presented. A detailed description is given of the modeling of internal diffusion and growth of cells in the support matrix in addition to external mass transfer resistance. The model predicts the substrate and biomass profiles in the support as well as the macroscopic oxygen consumption rate of the immobilized biocatalyst in time. The model is tested by experiments with continuously operated airlift loop reactors containing cells immobilized in kappa-carrageenan. The model describes experimental data very well. It is clearly shown that external mass transfer may not be neglected. Furthermore, a sensitivity analysis of the parameters at their values during the experiments revealed that apart from the radius of the spheres and the substrate bulk concentration, the external mass transfer resistance coefficient is the most sensitive parameter for our case.

Grassland degradation caused by tourism activities in Hulunbuir, Inner Mongolia, China

International Nuclear Information System (INIS)

Le, C; Ikazaki, K; Siriguleng; Kosaki, T; Kadono, A

2014-01-01

The recent increase in the number of tourists has raised serious concerns about grassland degradation by tourism activities in Inner Mongolia. Thus, we evaluated the effects of tourism activities on the vegetation and soil in Hulunbuir grassland. We identified all the plant species, measured the number and height of plant and plant coverage rate, and calculated species diversity, estimated above-ground biomass in use plot and non-use plot. We also measured soil hardness, and collected soil samples for physical and chemical analysis in both plots. The obtained results were as follows: a) the height of the dominant plants, plant coverage rate, species diversity, and above-ground biomass were significantly lower in use plot than in non-use plot, b) Carex duriuscula C.A.Mey., indicator plant for soil degradation, was dominant in use plot, c) soil hardness was significantly higher in use plot than in non-use plot, and spatial dependence of soil hardness was only found in the use plot, d) CEC, TC, TN and pH in the topsoil were significantly lower in use plot than non-use plot. On the basis of the results, we concluded that the tourism activities can be another major cause of the grassland degradation in Inner Mongolia

Grassland degradation caused by tourism activities in Hulunbuir, Inner Mongolia, China

Science.gov (United States)

Le, C.; Ikazaki, K.; Siriguleng; Kadono, A.; Kosaki, T.

2014-02-01

The recent increase in the number of tourists has raised serious concerns about grassland degradation by tourism activities in Inner Mongolia. Thus, we evaluated the effects of tourism activities on the vegetation and soil in Hulunbuir grassland. We identified all the plant species, measured the number and height of plant and plant coverage rate, and calculated species diversity, estimated above-ground biomass in use plot and non-use plot. We also measured soil hardness, and collected soil samples for physical and chemical analysis in both plots. The obtained results were as follows: a) the height of the dominant plants, plant coverage rate, species diversity, and above-ground biomass were significantly lower in use plot than in non-use plot, b) Carex duriuscula C.A.Mey., indicator plant for soil degradation, was dominant in use plot, c) soil hardness was significantly higher in use plot than in non-use plot, and spatial dependence of soil hardness was only found in the use plot, d) CEC, TC, TN and pH in the topsoil were significantly lower in use plot than non-use plot. On the basis of the results, we concluded that the tourism activities can be another major cause of the grassland degradation in Inner Mongolia.

Anti-inflammatory effects of linezolid on carrageenan-induced paw edema in rats.

Science.gov (United States)

Matsumoto, Kazuaki; Obara, Shigeaki; Kuroda, Yuko; Kizu, Junko

2015-12-01

The immunomodulatory activity of linezolid has recently been reported using in vitro experimental models. However, the anti-inflammatory activity of linezolid has not yet been demonstrated using in vivo experimental models. Therefore, the aim of the present study was to demonstrate the anti-inflammatory activity of linezolid and other anti-MRSA agents using the carrageenan-induced rat paw edema model. The pretreatment with 50 mg/kg linezolid significantly suppressed edema rates, compared with control (5% glucose), with edema rates at 0.5 and 3 h after the administration of carrageenan being 17.3 ± 3.5 and 30.8 ± 3.0%, respectively. On the other hand, edema rates were not suppressed by the pretreatments with 50 mg/kg vancomycin, teicoplanin, arbekacin, and daptomycin. Furthermore, we demonstrated that linezolid exhibited anti-inflammatory activity in a concentration-dependent manner. These effects were observed at linezolid concentrations that are achievable in human serum with conventional dosing. In conclusion, the results of the present study suggest that the anti-inflammatory activities of linezolid, in addition to its antimicrobial effects, have a protective effect against destructive inflammatory responses in areas of inflammation. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Stable Isotope Fractionation Caused by Glycyl Radical Enzymes during Bacterial Degradation of Aromatic Compounds

Science.gov (United States)

Morasch, Barbara; Richnow, Hans H.; Vieth, Andrea; Schink, Bernhard; Meckenstock, Rainer U.

2004-01-01

Stable isotope fractionation was studied during the degradation of m-xylene, o-xylene, m-cresol, and p-cresol with two pure cultures of sulfate-reducing bacteria. Degradation of all four compounds is initiated by a fumarate addition reaction by a glycyl radical enzyme, analogous to the well-studied benzylsuccinate synthase reaction in toluene degradation. The extent of stable carbon isotope fractionation caused by these radical-type reactions was between enrichment factors (ɛ) of −1.5 and −3.9‰, which is in the same order of magnitude as data provided before for anaerobic toluene degradation. Based on our results, an analysis of isotope fractionation should be applicable for the evaluation of in situ bioremediation of all contaminants degraded by glycyl radical enzyme mechanisms that are smaller than 14 carbon atoms. In order to compare carbon isotope fractionations upon the degradation of various substrates whose numbers of carbon atoms differ, intrinsic ɛ (ɛintrinsic) were calculated. A comparison of ɛintrinsic at the single carbon atoms of the molecule where the benzylsuccinate synthase reaction took place with compound-specific ɛ elucidated that both varied on average to the same extent. Despite variations during the degradation of different substrates, the range of ɛ found for glycyl radical reactions was reasonably narrow to propose that rough estimates of biodegradation in situ might be given by using an average ɛ if no fractionation factor is available for single compounds. PMID:15128554

Prevention of carrageenan-induced pleurisy in mice by anti-CD30 ligand monoclonal antibody

DEFF Research Database (Denmark)

Di Paola, Rosanna; Di Marco, Roberto; Mazzon, Emanuela

2004-01-01

CD30 ligand (CD30L) and its receptor CD30 are members of the tumor necrosis factor (TNF) and TNF receptor superfamilies that play a major role in inflammation and immune regulation. To gain insight into the in vivo role of CD30L/CD30 in inflammatory diseases, we have used carrageenan (CAR)-induce...

Evaluation of the protective effect of pentoxifylline on carrageenan-induced chronic non-bacterial prostatitis in rats.

Science.gov (United States)

Hajighorbani, Mahboobeh; Ahmadi-Hamedani, Mahmood; Shahab, Elaheh; Hayati, Farzad; Kafshdoozan, Khatereh; Keramati, Keivan; Amini, Amin Hossein

2017-06-01

Chronic non-bacterial prostatitis (CNP) is the most common type of prostatitis and oxidative stress (OS) was shown to be highly elevated in prostatitis patients. This study aimed to investigate the protective effect of pentoxifylline (PTX) on CNP induced by carrageenan in rats. Male adult Wistar rats (n = 30) were divided into control, CNP and three treatment groups (n = 6) including CNP + cernilton and CNP + PTX groups. CNP was induced by single intraprostatic injection of 1% carrageenan (100 µl). Rats in treatment groups received orally cernilton 100 mg/kg and PTX at 50 and 100 mg/kg 1 week after CNP induction for 21 days. Prostatic index (PI), prostatic specific antigen (PSA), tumor-necrosis factor alpha (TNF-α), serum lipid peroxidation (MDA), blood urea nitrogen, creatinine and histopathological changes were compared between groups. There were significant increase of PI, serum levels of PSA, TNF-α and MDA in CNP group at 29 day. In treatment groups, significant reduction in PI, serum levels of PSA, TNF-α, MDA and creatinine was observed especially in rats treated with dose of 50 mg/kg of PTX. In CNP group, histopathological changes of the prostate such as leucocyte infiltration, large involutions and projection into the lumen and reducing the volume of the lumen were observed as well. Whereas PTX, especially at dose of 50 mg/kg, could improve the above-mentioned changes remarkably in CNP treated rats. For the first time, our findings indicated that PTX improved CNP induced by carrageenan in rats.

Characterization of k-carrageenan/Locust bean gumbased films with b-carotene emulsion

OpenAIRE

Martins, Joana; Silva, H. D.; Rojas, R.; Aguilar, Cristóbal N.; Vicente, A. A.

2014-01-01

New bio-based materials have been exploited to develop biodegradable and edible films as an effort to extend shelf life and improve quality of food while reducing packaging waste. The objective of this study was to investigate physicochemical properties of k-carrageenan/locust bean gum (k-car/LBG) films with different bcarotene emulsion concentrations. To prepare oil-in-water emulsions, b-carotene (0.03% v/v) was dissolved in mediumchain triglycerides (MCTs), and the solution was mixed ...

Radioprotection potential of the ascorbic acid on the carrageenan used as food additive; Potencial radioprotetor do acido ascorbico sobre a carragenana utilizada como aditivo alimenticio

Energy Technology Data Exchange (ETDEWEB)

Aliste, Antonio Joao; Mastro, Nelida Lucia del [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: ajaliste@net.ipen.br; nlmastro@net.ipen.br

2002-07-01

Carrageenans are a group of natural carbohydrates that are present in the structure of certain varieties of red algae (Rhodophyceae). They are used in emulsions, for syneresis control and to grow up, to promote adhesiveness and dispersion. In the industry of foods they can be used for instance, as thickness and gelling agents, alone or together with other additives. The processing of foods by radiation is increasing considerably, because the efficiency of the process in the industrial decontamination of products. The objective of this work was to study the action of the ascorbic acid as potential radioprotector of the carrageenan against {sup 60} Co gamma radiation effects, using the viscosity as parameter. Samples of commercial carrageenan dissolved at 1,0% were irradiated in the presence or not of ascorbic acid, with doses of 0.0 kGy; 1.0 kGy; 2.5 kGy; 5.0 kGy and 10.0 kGy. After the irradiation the relationships viscosity/dose were established for the temperature of 60 deg C. For the dose of 10.0 kGy a better protecting effect of the ascorbic acid on the carrageenan was seen. The implications of the use of this antioxidant is discussed as a form of minimizing the effect of the radiation in irradiated foods. (author)

Microwave-Assisted Synthesis of kappa-Carrageenan Beads Containing Silver Nanoparticles with Dye Adsorption and Antibacterial Properties

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Hossein Hosseinzadeh

2016-04-01

Full Text Available In this work, we used a simple and totally green method for synthesizing silver nanoparticles using kappa-carrageenan as reducing and stabilizing agent. The beads were prepared in aqueous medium by microwave heating, and then followed by cross-linking with K+ cations without using any additional toxic and expensive chemical agents. The preparation method of the carrageenan-based beads is easy, fast, simple, effective, and safe. The synthesized beads loaded with were characterized by ultraviolet-visible absorbance spectra, transmition electron microscopy and X-Ray diffraction techniques. The as-prepared beads were evaluated to remove cationic crystal violet dye from aqueous solutions. The thermodynamic parameters shown that the sorption process was feasible, spontaneous and endothermic. The kinetics and isotherm of crystal violet adsorption were found to well fit to pseudo-second-order kinetic and Langmuir isotherm model, respectively. Moreover, the antibacterial activity of the obtained beads was examined using the nutrient agar disc diffusion method.

Carrageenan-based semi-IPN nanocomposite hydrogels: Swelling kinetic and slow release of sequestrene Fe 138 fertilizer

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Mohammad Kazem Bahrami

2016-09-01

Full Text Available Nanocomposite hydrogels based on kappa-carrageenan were synthesized by incorporating natural sodium montmorillonite (Cloisite nanoclay. Acrylamide (AAm and methylenebisacrylamide (MBA were used as a monomer and a crosslinker, respectively. Effects of reaction variables on the swelling kinetics were studied. The results revealed that the rate of swelling for nanocomposites with high content of MBA was higher than those of nanocomposites consisting of low content of MBA. Similar to the effect of MBA, the rate of swelling enhanced as the carrageenan content was decreased. The influence of clay content on swelling rate was not remarkable. The experimental swelling data were evaluated by pseudo-first-order and pseudo-second-order kinetic models. The swelling data described well by pseudo-second-order kinetic model. Sequestrene Fe 138 (Sq as an agrochemical was loaded into nanocomposites and releasing of this active agent from nanocomposites was studied. The clay-free hydrogel released the whole loaded Sq; whereas the presence of clay restricted the release of Sq.

Causes of degradation and erosion of a blanket mire in the southern Pennines, UK

NARCIS (Netherlands)

Yeloff, D.; Hunt, C.O.; Labadz, J.C.

2006-01-01

This study investigates the causes of erosion and degradation of March Haigh, a blanket mire in the southern Pennines (UK), over a period of 160 years starting in 1840 AD. Peat samples taken from the site were dated using 210Pb; their humification and magnetic susceptibility were measured; and they

Carboxymethylated ɩ-carrageenan conjugated amphotericin B loaded gelatin nanoparticles for treating intracellular Candida glabrata infections.

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Aparna, V; Melge, Anu Rohit; Rajan, V K; Biswas, Raja; Jayakumar, R; Gopi Mohan, C

2018-04-15

Intercellular Candida glabrata infections are difficult to treat due to poor penetration of drugs into the fungal niche. Delivering amphotericin B (Amp B) into the macrophages where the pathogen inhabits is an effective solution. We are studying the macrophage targeting proficiency of ɩ-carrageenan for the delivery of Amp B using gelatin A nanoparticles (GNPs). The choice of gelatin A was the outcome of in silico inspections where the amino functionalized polymer having the best docking score with Amp B was selected. We prepared a sustained release formulation of amp B loaded carboxymethyl ɩ-carrageenan conjugated gelatin nanoparticles (CMC-Amp B-GNPs) with size 343±12nm and -25±5.3mV zeta potential. The formulations were found to be stable, biocompatible and non-haemolytic. Flow cytometry analysis showed 3 fold higher uptake of CMC-GNPs compared to the GNPs by RAW 264.7 cells. CMC-Amp B-GNPs showed enhanced antifungal activity than bare Amp B and Amp B-GNPs. Copyright © 2017 Elsevier B.V. All rights reserved.

Kappa-Carrageenan : a study on its physico-chemical properties, sol-gel transition and interaction with milk proteins

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Snoeren, T.H.M.

1976-01-01

In this thesis a characterization of the milkreactive polysaccharide κ-carrageenan by means of light scattering, viscosimetry and sedimentation experiments is presented. The disorder/order transitions occurring at the gelpoint of these substances are discussed in terms of a coil/double

Identification of component performance degradations caused by ageing using expert panels

International Nuclear Information System (INIS)

Nitoi, Mirela; Cristea, Dumitru; Pavelescu, Margarit

2008-01-01

Since the component ageing can be considered as one of the important causes of operating events reported, the identification of ageing effects and implementation of appropriate methods for mitigation of these effects represent an important preoccupation of many organizations and research activities. In the process of identification of ageing manifestation we can use either analysis of operational data or expert opinions, each of the methods having specific advantages and disadvantages. A reasonable combination of statistical, structural reliability and expert panel methods would be an appropriate approach in the failure probability assessments. In case when there are not enough operational data, the expert judgments represent the only viable alternative in the effort dedicated to identification of components and systems vulnerability to ageing. The panel use judgments to analyse the degradation produced by ageing, to score the components based on specific criteria and to rank them relative to one another. The paper presents the approach developed, including evaluation criteria and assigning indices for assessment of particular types of ageing degradation (the case of secondary system of TRIGA reactor). (authors)

Chemical and Electrochemical Synthesis of Polypyrrole Using Carrageenan as a Dopant: Polypyrrole/Multi-Walled Carbon Nanotube Nanocomposites

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Mostafizur Rahaman

2018-06-01

Full Text Available In this article, iota-carrageenan (IC and kappa-carrageenan (KC are used as dopants for the chemical and electrochemical synthesis of polypyrrole (PPy. The composites of chemically synthesized PPy with multi-walled carbon nanotubes (MWNTs were prepared using an in situ technique. Both the dialyzed and non-dialyzed IC and KC were used as dopants for electrochemical polymerization of pyrrole. Chemically synthesized PPy and PPy/MWNTs composites were studied by ultraviolet visible (UV-vis absorption spectra to investigate the effect of the concentration and the incorporation of MWNTs. In addition, the electrical, thermal, mechanical, and microscopic characterizations of these films were performed to examine the effect of the dopants and MWNTs on these properties, along with their surface morphology. The films of electrochemically polymerized PPy were characterized using UV-vis absorption spectra, scanning electron microscopy, and cyclic voltammetry (CV. The results were then compared with the chemical polymerized PPy.

Gamma radiation effects on the viscosity of carrageenan, agarans and alginates to be used as food additives

International Nuclear Information System (INIS)

Aliste, Antonio Joao

1999-01-01

Carrageenan, agarans and alginates are phycocolloids, which change the consistence of the foodstuff and prevent undesirable changes such as moisture migration or textural profile changes. These phycocolloids are additives used in large scale for all kind of food products. They are not absorbed for the human organism and do not introduce extra calories in the diet. The process of irradiation, is an alternative method of great potential, because do not increase the temperature and it is highly in the decontamination of food ingredients. In this work, agar alginates and carrageenan were irradiated as powder with different doses (0-10kGy) of Co-60 and the rheological functional performance of water solutions of the irradiated additives was studied. The results are analyzed taking in account the future applications of those additives in irradiated foods. The viscosity of these hydrocolloids shows a decrease when submitted to an irradiation with doses until 10 kGy. (author)

High Performances of Artificial Nacre-Like Graphene Oxide-Carrageenan Bio-Nanocomposite Films.

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Zhu, Wenkun; Chen, Tao; Li, Yi; Lei, Jia; Chen, Xin; Yao, Weitang; Duan, Tao

2017-05-16

This study was inspired by the unique multi-scale and multi-level 'brick-and-mortar' (B&M) structure of nacre layers. We prepared the B&M, environmentally-friendly graphene oxide-carrageenan (GO-Car) nanocomposite films using the following steps. A natural polyhydroxy polymer, carrageenan, was absorbed on the surface of monolayer GO nanosheets through hydrogen-bond interactions. Following this, a GO-Car hybridized film was produced through a natural drying process. We conducted structural characterization in addition to analyzing mechanical properties and cytotoxicity of the films. Scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses showed that the nanocomposite films had a similar morphology and structure to nacre. Furthermore, the results from Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Thermogravimetric (TG/DTG) were used to explain the GO-Car interaction. Analysis from static mechanical testers showed that GO-Car had enhanced Young's modulus, maximum tensile strength and breaking elongation compared to pure GO. The GO-Car nanocomposite films, containing 5% wt. of Car, was able to reach a tensile strength of 117 MPa. The biocompatibility was demonstrated using a RAW264.7 cell test, with no significant alteration found in cellular morphology and cytotoxicity. The preparation process for GO-Car films is simple and requires little time, with GO-Car films also having favorable biocompatibility and mechanical properties. These advantages make GO-Car nanocomposite films promising materials in replacing traditional petroleum-based plastics and tissue engineering-oriented support materials.

Carrageenan type effect on soybean oil/soy protein isolate emulsion employed as fat replacer in panela-type cheese

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Rojas-Nery, E.

2015-12-01

Full Text Available In order to modify the fatty acid profile of panela-type cheese (a Mexican fresh cheese, emulsified soybean oil with soy protein isolate and different carrageenan (iota, kappa or lambda was employed as fat replacer. The replacement of milk fat in panela-type cheese resulted in higher cheese yield values and moisture content, besides a concomitant lower fat phase and higher protein content, due to a soy protein isolate in emulsified soybean oil. Fat replacement resulted in a harder but less cohesive, spring and resilient texture, where differences in texture could be attributed to the specific carrageenan-casein interactions within the rennet coagulated cheese matrix. The FTIR analysis showed that the milk fat replacement changed the fatty acid profile, also in function of the type of carrageenan employed. Lambda carrageenan containing emulsions improved moisture retention and maintained the textural properties of panela-type cheese.Para modificar el perfil de ácidos grasos de los quesos tipo panela (queso fresco popular en México, se utilizó aceite de soja emulsionado con aislado de proteína de soja y diferentes carrageninas (iota, kappa o lambda como sustituto de la grasa. Reemplazar la grasa de la leche en el queso tipo panela resultó en mayor rendimiento quesero y mayor contenido de humedad, además de una concomitante menor fase grasa y mayor contenido de proteína, debido al aislado de proteína de soja en el aceite de soja emulsionado. La sustitución de la grasa dio como resultado una textura más dura, pero menos cohesiva, elástica y resiliente, donde estas diferencias podrían ser atribuidas a la interacción especifica entre carrageninas-caseinas en la matriz coagulada del queso. El análisis de FTIR muestra que reemplazar la grasa de la leche cambia el perfil de ácidos grasos, también en función del tipo de carragenina empleado. Las emulsiones con lambda carrageninas mejoraron la retención de humedad y mantuvieron las

Application of Essential Oils from Galanga Rhizome in Edible Coating Carrageenan as Antibacterial on Tilapia Fishball

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Fajar Bayu Senoaji

2017-08-01

Full Text Available Fish ball is a perishable food product. One of an alternative method which could be applied to delay the deterioration process was using carrageenan edible coating with the addition of galangal rhizome’s essential oil as an antibacterial agent. The aim of this study was to find out whether the addition of carrageenan edible coating with galangal rhizome’s essential oil could increase the shelf life of the tilapia fish ball during cold storage or not. This study was used experimental laboratories with the completely randomized design used factorial (2x6 two factors include essential oils concentrations (0%, dan 1% and storage time (0, 3, 6, 9, 12, 15 with three repetitions. The shelf life of the fish ball observed by sensory, TPC, TVBN, pH, Aw, moisture content, and gel strength test. The parametric data were analyzed by the ANOVA, while the non-parametric was using the Kruskal Wallis test. As the result, the fish ball with the 1% treatment was still acceptable until 15 days of storage compared with the control which only lasts for 9 days. The other results were the sensory test was 6.63≤π≤6.95, TPC value was 1.07x105 cfu/g, TVBN value was 30.33±1.68 mgN%, the moisture content was 61.38%±0.47, the Aw was 0.89±0.006, the pH was 6.24±0.0, and the gel strength was 721.19±1.61 g.cm. The treatment of 1% essential oil addition to carrageenan edible coating was significantly different (p<0.05 compared to the control treatment during cold storage to the characteristic of tilapia fish ball.

Mechanical and water barrier properties of agar/κ-carrageenan/konjac glucomannan ternary blend biohydrogel films.

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Rhim, Jong-Whan; Wang, Long-Feng

2013-07-01

Multicomponent hydrogel films composed of agar, κ-carrageenan, konjac glucomannan powder, and nanoclay (Cloisite(®) 30B) were prepared and their mechanical and water barrier properties such as water vapor permeability (WVP), water contact angle (CA), water solubility (WS), water uptake ratio (WUR), water vapor uptake ratio (WVUR) were determined. Mechanical, water vapor barrier, and water resistance properties of the ternary blend film exhibited middle range of individual component films, however, they increased significantly after formation of nanocomposite with the clay. Especially, the water holding capacity of the ternary blend biopolymer films increased tremendously, from 800% to 1681% of WUR for agar and κ-carrageenan films up to 5118% and 5488% of WUR for the ternary blend and ternary blend nanocomposite films, respectively. Water vapor adsorption behavior of films was also tested by water vapor adsorption kinetics and water vapor adsorption isotherms test. Preliminary test result for fresh spinach packaging revealed that the ternary blend biohydrogel films had a high potential for the use as an antifogging film for packaging highly respiring agricultural produce. In addition, the ternary blend nanocomposite film showed an antimicrobial activity against Gram-positive bacteria, Listeria monocytogenes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of Nigella Sativa Linn (Ranunculaceae ground seed extract on Carrageenan induced inflammation in rats

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Saima Parveen

2011-01-01

Full Text Available Nigella sativa Linn (Family: Ranunculaceae Bengali name “kalo jera” is used as spice in Bengali foods. Native to Western Asia, Turkey, Iraq and Egypt, the black seed oil has been valued for its health benefits for centuries. This plant has been used in traditional medicine for the treatment of stomach aches, asthma, bronchitis, coughs, fevers, tumour and as a tonic. The dried and grounded seed was extracted with ethanol and the extract was evaluated for anti-inflammatory activity in carrageenan induced rat paw edema model. The extracts were administered orally at the doses of 250 and 500 mg/kg body weight, and statistically significant (p<0.05 anti-inflammatory effects were observed in a dose dependant manner. The extract showed 28.75% and 43.79% inhibition of inflammation at the doses of 250 and 500 mg/kg body weight after first hour of the carrageenan administration which was comparable to that of standard drugs aspirin 40.52% and hydrocortisone 47.71% respectively. The result of this study supported the traditional medicinal uses of this seed. Ibrahim Med. Coll. J. 2011; 5(1: 22-24

The effects of sucrose on the mechanical properties of acid milk proteins-kappa-carrageenan gels

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E. Sabadini

2006-03-01

Full Text Available Mechanical properties have been widely correlated with textural characteristics to determine the interactions during the process formation of dairy gel. These interactions are strongly affected by process conditions and system composition. In the present study, the rheological of acid-induced protein dairy gels with (2(7-3 and without (2(6-2 sucrose and subjected to small and large deformations were studied using an experimental design. The independent variables were the sodium caseinate, whey protein concentrate (WPC, carrageenan and sucrose concentrations as well as stirring speed and heat treatment time and temperature. Mechanical deformation tests were performed at 0.1, 1, 5, and 9 mm/s up to 80% of initial height. A heavy dependence of rupture stress on increasing crosshead speed and the formation of harder gels with the addition of sucrose were observed. Moreover the elastic and viscous moduli, obtained by fitting the Maxwell model to stress relaxation data, increased with increasing addition of sucrose. These results can be explained by preferential hydration of the casein with sucrose, causing an induction of casein-polysaccharide and casein-casein interactions.

High Performances of Artificial Nacre-Like Graphene Oxide-Carrageenan Bio-Nanocomposite Films

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Wenkun Zhu

2017-05-01

Full Text Available This study was inspired by the unique multi-scale and multi-level ‘brick-and-mortar’ (B&M structure of nacre layers. We prepared the B&M, environmentally-friendly graphene oxide-carrageenan (GO-Car nanocomposite films using the following steps. A natural polyhydroxy polymer, carrageenan, was absorbed on the surface of monolayer GO nanosheets through hydrogen-bond interactions. Following this, a GO-Car hybridized film was produced through a natural drying process. We conducted structural characterization in addition to analyzing mechanical properties and cytotoxicity of the films. Scanning electron microscope (SEM and X-ray diffraction (XRD analyses showed that the nanocomposite films had a similar morphology and structure to nacre. Furthermore, the results from Fourier transform infrared spectroscopy (FT-IR, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS and Thermogravimetric (TG/DTG were used to explain the GO-Car interaction. Analysis from static mechanical testers showed that GO-Car had enhanced Young’s modulus, maximum tensile strength and breaking elongation compared to pure GO. The GO-Car nanocomposite films, containing 5% wt. of Car, was able to reach a tensile strength of 117 MPa. The biocompatibility was demonstrated using a RAW264.7 cell test, with no significant alteration found in cellular morphology and cytotoxicity. The preparation process for GO-Car films is simple and requires little time, with GO-Car films also having favorable biocompatibility and mechanical properties. These advantages make GO-Car nanocomposite films promising materials in replacing traditional petroleum-based plastics and tissue engineering-oriented support materials.

Preliminary study of semi-refined carrageenan (SRC) as secondary gelling agent in natural rubber (NR) latex foam

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Norhazariah, S.; Azura, A. R.; Azahari, B.; Sivakumar, R.

2017-12-01

Semi-refined carrageenan (SRC) product is considerably cheaper and easier to produce as a natural polysaccharide, which was utilized in food and other product application. However, the application in latex is limited. The aim of this work is to evaluate the SRC produced from low industrial grade seaweed (LIGS) in the latex foam application. The FTIR spectra showed the SRC produced as kappa type carrageenan with lower sulfur content compared to native LIGS. NR latex foam is produced by using the Dunlop method with some modifications. The effect of SRC loading as a secondary gelling agent in NR latex foam is investigated. The density and morphology of the NR latex foam with the addition of the SRC are analyzed. NR latex foam density increased with SRC loading and peaked at 1.8 phr SRC. The addition of SRC has induced the bigger cell size compared to the cell size of the control NR latex foam, as shown in the optical micrograph. It can be concluded that SRC LIGS could be acted as secondary gelling agent in NR latex foam.

A model of peripheral microvascular injury: irreversible caudal necrosis induced in carrageenan-inflamed rats treated with anti-inflammatory drugs and mild chilling: a pluricausal thrombo-haemorrhagic phenomenon.

Science.gov (United States)

Whitehouse, M W; Rainsford, K D

1985-01-01

A florid tail injury was observed in carrageenan-inflamed rats previously treated with acidic non-steroidal anti-inflammatory (NSAI) drugs to suppress paw inflammation and then exposed to mild chilling (7-10 degrees C for 10-16 h). All three treatments, i.e. NSAI drug + carrageenan paw oedema + mild chilling treatment, were required for the development of this condition. Histological observations suggest that the tissue necrosis was initiated by a primary disturbance of the peripheral vasculature. The possible involvement of suppressed prostaglandin (PG) production in the aetiology of this condition is indicated by the fact that it was totally reversed by prior treatment with PGE2. This appears to be a classical pluricausal thrombohaemorrhagic phenomenon (of Selye), with cold-stress being the sensitizer and carrageenan and NSAI drugs being the challenger. The possibilities are considered of employing this tail injury model as a convenient method of developing drugs to control microvascular disturbances in man.

Protective effect of Arbutus unedo aqueous extract in carrageenan-induced lung inflammation in mice.

Science.gov (United States)

Mariotto, Sofia; Esposito, Emanuela; Di Paola, Rosanna; Ciampa, Anna; Mazzon, Emanuela; de Prati, Alessandra Carcereri; Darra, Elena; Vincenzi, Simone; Cucinotta, Giovanni; Caminiti, Rocco; Suzuki, Hisanori; Cuzzocrea, Salvatore

2008-02-01

In the present study, we show that an aqueous extract of Arbutus unedo L. (AuE), a Mediterranean endemic plant widely employed as an astringent, diuretic and urinary anti-septic, in vitro down-regulates the expression of some inflammatory genes, such as those encoding inducible nitric oxide synthase (iNOS) and intracellular adhesion molecule-(ICAM)-1, exerting a inhibitory action on both IFN-gamma-elicited STAT1 activation and IL-6-elicited STAT3 activation. To evaluate further the effect of AuE in animal models of acute inflammation, we examined whether AuE administration attenuates inflammatory response of murine induced by intrapleural injection of carrageenan. For this purpose we studied: (1) STAT1/3 activation, (2) TNF-alpha, IL-1beta and IL-6 production in pleural exudate, (3) lung iNOS, COX-2 and ICAM-1 expression, (4) neutrophil infiltration, (5) the nitration of cellular proteins by peroxynitrite, (6) lipid peroxidation, (7) prostaglandin E2 and nitrite/nitrate levels and (8) lung injury. We show that AuE strongly down-regulates STAT3 activation induced in the lung by carrageenan with concomitant attenuation of all parameters examined associated with inflammation, suggesting that STAT3 should be a new molecular target for anti-inflammatory treatment. This study demonstrates that acute lung inflammation is significantly attenuated by the treatment with AuE.

Rheological behavior and non-enzymatic degradation of a sulfated galactan from Halymenia durvillei (Halymeniales, Rhodophyta).

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Fenoradosoa, Taratra André; Laroche, Céline; Delattre, Cedric; Dulong, Virginie; Le Cerf, Didier; Picton, Luc; Michaud, Philippe

2012-07-01

The rheological behavior of a sulfated galactan extracted from Halymenia durvillei, a red seaweed collected in the coastal waters of a small island of Madagascar (Nosy-be in Indian Ocean), was investigated in dilute and semi-dilute solutions. In dilute solution with NaCl at 0.3 M, the polysaccharide adopted a coil conformation whereas, at higher concentrations, the polymer had the behavior of shear-thinning fluid, typical of polymer with high molar mass or semi-rigid conformation. Degradations of this lambda carrageenan-like, using radical depolymerization, and high-pressure homogenization led to several samples of various and controlled molar masses. The measure of their intrinsic viscosities permitted the determination of the relationship of Mark-Houwink-Sakurada.

Anti-inflammatory effect of bee pollen ethanol extract from Cistus sp. of Spanish on carrageenan-induced rat hind paw edema

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Araki Yoko

2010-06-01

Full Text Available Abstract Background Bee pollen, a honeybee product, is the feed for honeybees prepared themselves by pollens collecting from plants and has been consumed as a perfect food in Europe, because it is nutritionally well balanced. In this study, we aimed to investigate the anti-inflammatory effect of bee pollen from Cistus sp. of Spanish origin by a method of carrageenan-induced paw edema in rats, and to investigate the mechanism of anti-inflammatory action and also to elucidate components involved in bee pollen extracted with ethanol. Methods The bee pollen bulk, its water extract and its ethanol extract were administered orally to rats. One hour later, paw edema was produced by injecting of 1% solution of carrageenan, and paw volume was measured before and after carrageenan injection up to 5 h. The ethanol extract and water extract were measured COX-1 and COX-2 inhibitory activities using COX inhibitor screening assay kit, and were compared for the inhibition of NO production in LPS-stimulated RAW 264.7 cells. The constituents of bee pollen were purified from the ethanol extract subjected to silica gel or LH-20 column chromatography. Each column chromatography fractions were further purified by repeated ODS or silica gel column chromatography. Results The bee pollen bulk mildly suppressed the carrageenan-induced paw edema and the water extract showed almost no inhibitory activity, but the ethanol extract showed relatively strong inhibition of paw edema. The ethanol extract inhibited the NO production and COX-2 but not COX-1 activity, but the water extract did not affect the NO production or COX activities. Flavonoids were isolated and purified from the ethanol extract of bee pollen, and identified at least five flavonoids and their glycosides. Conclusions It is suggested that the ethanol extract of bee pollen show a potent anti-inflammatory activity and its effect acts via the inhibition of NO production, besides the inhibitory activity of COX-2

Untangling the proximate causes and underlying drivers of deforestation and forest degradation in Myanmar.

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Lim, Cheng Ling; Prescott, Graham W; De Alban, Jose Don T; Ziegler, Alan D; Webb, Edward L

2017-12-01

Political transitions often trigger substantial environmental changes. In particular, deforestation can result from the complex interplay among the components of a system-actors, institutions, and existing policies-adapting to new opportunities. A dynamic conceptual map of system components is particularly useful for systems in which multiple actors, each with different worldviews and motivations, may be simultaneously trying to alter different facets of the system, unaware of the impacts on other components. In Myanmar, a global biodiversity hotspot with the largest forest area in mainland Southeast Asia, ongoing political and economic reforms are likely to change the dynamics of deforestation drivers. A fundamental conceptual map of these dynamics is therefore a prerequisite for interventions to reduce deforestation. We used a system-dynamics approach and causal-network analysis to determine the proximate causes and underlying drivers of forest loss and degradation in Myanmar from 1995 to 2016 and to articulate the linkages among them. Proximate causes included infrastructure development, timber extraction, and agricultural expansion. These were stimulated primarily by formal agricultural, logging, mining, and hydropower concessions and economic investment and social issues relating to civil war and land tenure. Reform of land laws, the link between natural resource extraction and civil war, and the allocation of agricultural concessions will influence the extent of future forest loss and degradation in Myanmar. The causal-network analysis identified priority areas for policy interventions, for example, creating a public registry of land-concession holders to deter corruption in concession allocation. We recommend application of this analytical approach to other countries, particularly those undergoing political transition, to inform policy interventions to reduce forest loss and degradation. © 2017 The Authors. Conservation Biology published by Wiley

Use of antioxidants substances to protect the hydrocolloids carrageenan, agaran and alginates used in food industry when exposed to radiation

International Nuclear Information System (INIS)

Aliste, Antonio Joao

2006-01-01

Carrageenan, agaran e alginates are hydrocolloids largely employed in every kind of food products as stabilizing agent and viscosity builder. The human body does not absorb them, so they do not introduce extra calories in the diet. Irradiation is presented as an important alternative method in food preservation because do not induce temperature increase being of good efficiency in cold food ingredients decontamination. In this work aqueous solutions of carrageenan, agar e sodium alginate were gamma irradiated (0-10 kGy) in presence of ascorbic acid, roselle (Hibiscus sabdariffa L.) extract and soy isoflavone. Edible polysaccharide solutions showed to be suitable systems for the evaluation of ionizing radiation effects as they presented a singular radiosensitivity through viscosity changes. The results obtained showed that in general the antioxidants employed had a radioprotective action that can be of importance in the future commercial applications of food irradiation. (author)

Corrosion inhibition of iota-carrageenan natural polymer on aluminum in presence of zwitterion mediator in HCl media

International Nuclear Information System (INIS)

Fares, Mohammad M.; Maayta, A.K.; Al-Mustafa, Jamil A.

2012-01-01

Highlights: ► Inhibition of Al by ι-carrageenan in the presence of zwitterion mediator was investigated. ► Considerable improvement in inhibition efficiency observed in the presence of zwitterion mediator. ► Coherent physical adsorption layer was evidenced by kinetic and thermodynamic parameters. ► Small but consistent fractured island layers observed after acid exposure as revealed by SEM images. - Abstract: ι-Carrageenan a natural polymer has been used as corrosion inhibitor of aluminum in presence of pefloxacin mesylate, acting as zwitterionic mediator, in acidic medium. Considerable improvement in inhibition efficiency occurred in the presence of the mediator. Activation energy of corrosion and other thermodynamic parameters such as standard free energy, standard enthalpy, and standard entropy of the adsorption process revealed better and well-ordered physical adsorption layers in presence of pefloxacin. Adsorption isotherms in absence or presence of pefloxacin mediator appropriately fit in the Langmuir isotherms. The scanning electron microscope (SEM) images demonstrated smooth, glossy, and relatively coherent adsorption layers of the inhibitor on the metal surface in aqueous solution. After the exposure to 2.0 M HCl for 2 h, a smaller but consistent regular shaped fractured layer is obtained.

Specific effect of the linear charge density of the acid polysaccharide on thermal aggregation/ disaggregation processes in complex carrageenan/lysozyme systems

NARCIS (Netherlands)

Antonov, Y.; Zhuravleva, I.; Cardinaels, R.M.; Moldenaers, P.

2017-01-01

We study thermal aggregation and disaggregation processes in complex carrageenan/lysozyme systems with a different linear charge density of the sulphated polysaccharide. To this end, we determine the temperature dependency of the turbidity and the intensity size distribution functions in complex

Development of Carrageenan Hydrogel as a Sustained Release Matrix Containing Tocotrienol-Rich Palm-Based Vitamin E

International Nuclear Information System (INIS)

Yee, C.M.; Zafarizal Aldrin Azizul Hasan; Norashikin Ahmad; Hazimah, A.H.

2016-01-01

Topically applied hydrogel system as a general therapeutic mask for transdermal delivery of hydrophobic actives is not efficient due to the differences in polarity between the actives and the polymer network. This work presents a study on developing hydrogels based on carrageenan as a matrix for the delivery of a hydrophobic type of active, i.e. tocotrienol-rich palm-based vitamin E (TRPE) into the skin. The strength and flexibility of the hydrogel were increased by the inclusion of guar gum, potassium citrate and glycerine. The thermogravimetric analysis (TGA) results indicated a higher quantity of water in the hydrogel with glycerine while differential scanning calorimetry (DSC) showed three types of water molecules existed in the hydrogel. The hydrogel was non-irritating according to OECD Test Guideline No. 439 for in vitro skin irritation test. The hydrogel with TRPE fluids was able to permeate the polysulfone membrane and bioavailability of TRPE improved with the inclusion of PEG-40 hydrogenated castor oil mixture. Therefore, a carrageenan-based hydrogel with locust bean, guar gum, glycerine, potassium citrate and TRPE was successfully developed with good strength and flexibility and without any potential irritancy. The good bioavailability of TRPE-loaded in the hydrogel can be used for skin care application. (author)

Utilization of carrageenan, citric acid and cinnamon oil as an edible coating of chicken fillets to prolong its shelf life under refrigeration conditions.

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Khare, Anshul Kumar; Abraham, Robinson J J; Appa Rao, V; Babu, R Narendra

2016-02-01

The present study was conducted to determine efficacy of edible coating of carrageenan and cinnamon oil to enhance the shelf life of chicken meat stored under refrigeration conditions. Chicken breast was coated with carrageenan and cinnamon oil by three methods of application viz., spraying brushing and dipping. The coated meat was evaluated for drip loss, pH, thiobarbituric acid number (TBA), tyrosine value (TV), extract release volume (ERV), Warner-Bratzler shear force value (WBSFV), instrumental color, microbiological, and sensory qualities as per standard procedures. There was a significant difference observed for physicochemical parameters (pH, TBA, TV, ERV, drip loss and WBSFV) and microbiological analysis between storage periods in all the samples and between the control and treatments throughout the storage period but samples did not differed significantly for hunter color scores. However, there was no significant difference among three methods of application throughout the storage period though dipping had a lower rate of increase. A progressive decline in mean sensory scores was recorded along with the increase in storage time. The carrageenan and cinnamon edible coating was found to be a good alternative to enhance the shelf life of chicken meat under refrigeration conditions. It was also observed from study that dipping method of the application had comparatively higher shelf life than other methods of application.

Synthesis and electrical properties of polyaniline/iota-carrageenan biocomposites.

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Vega-Rios, Alejandro; Olmedo-Martínez, Jorge L; Farías-Mancilla, Bárbara; Hernández-Escobar, Claudia A; Zaragoza-Contreras, E Armando

2014-09-22

Polyaniline/iota-carrageenan (ι-CGN) biocomposites were synthesized via in situ methodology using ammonium persulfate as the oxidizing agent. Both ionic (band at 1131 cm(-1)) and hydrogen bond (bands at 2500 and 3500 cm(-1)) interactions between polyaniline and ι-CGN were determined by infrared spectroscopy. Such intermolecular interactions provided the biocomposites with a cross-linked structure that provided the materials with hydrogel behavior. Biocomposite electro-conductivity, determined by the 4-probe technique, was in the range of semiconductors (10(-3) to 10(-2) S cm(-1)); whereas electro-activity, assessed by cyclic voltammetry, showed the oxidation-reduction transitions typical of polyaniline. Based on the properties of polyaniline and ι-CGN, some applications for the new materials in the field of biosensor design, electrochemical capacitors, or tissue engineering scaffolds are possible. It is worth saying that both electro-conductive and electro-active properties of polyaniline/ι-CGN biocomposites are reported here for the first time. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biopolymer electrolytes based on blend of kappa-carrageenan and cellulose derivatives for potential application in dye sensitized solar cell

International Nuclear Information System (INIS)

Rudhziah, S.; Ahmad, A.; Ahmad, I.; Mohamed, N.S.

2015-01-01

In this work, carboxymethyl kappa-carrageenan was used as the principle host for developing new biopolymer electrolytes based on the blend of carboxymethyl kappa-carrageenan/carboxymethyl cellulose. The blending of carboxymethyl cellulose into carboxymethyl kappa-carragenan was found to be a promising strategy to improve the material properties such as conductive properties. The electrolyte samples were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, dynamic mechanical analysis, electrochemical impedance spectroscopy, ionic transference number measurement and linear sweep voltammetry in order to investigate their structural, thermal and electrochemical properties. Impedance study showed that the ionic conductivity increased with the increment of ammonium iodide concentration. The highest room temperature ionic conductivity achieved was 2.41 × 10 −3 S cm −1 at 30 wt% of the salt. The increment of conductivity was due to the increase of formation of transient cross-linking between the carboxymethyl kappa-carrageenan/carboxymethyl cellulose chains and the doping salt as indicated the T g trend. The conductivity was also attributed by the increase in the number of charge carriers in the biopolymer electrolytes system. The interactions between polymers and salt were confirmed by FTIR study. The transference number measurements showed that the conductivity was predominantly ionic. Temperature dependent conductivity study showed that conductivity increased with the reciprocal of temperature. The conductivity-temperature plots suggested that the conductivity obeyed the Vogel–Tammann–Fulcher relation and the activation energy for the best conducting sample was 0.010 eV. This system was used for the fabrication of dye sensitized solar cells, FTO/TiO 2 -dye/CMKC/CMCE-NH 4 I + I 2 /Pt. The fabricated cell showed response under light intensity of 100 mW cm −2 with efficiency of 0.13% indicating that the blend biopolymer

Activity of some Mexican medicinal plant extracts on carrageenan-induced rat paw edema.

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Meckes, M; David-Rivera, A D; Nava-Aguilar, V; Jimenez, A

2004-07-01

The extracts obtained from 14 plants of the Mexican medicinal flora were assessed for anti-inflammatory activity by carrageenan-induced rat paw edema model. The i.p. administration of the extracts at a dose of 400 mg/kg produced a high reduction of edema with 70% of the plant extracts. Oenothera rosea methanol extract, Sphaeralcea angustifolia chloroform extract, Acaciafarnesiana, Larrea tridentata and Rubus coriifolius methanol extracts as well as the aqueous extract of Chamaedora tepejilote were demonstrated to be particularly active against the induced hind-paw edema. Moderate inhibition of edema formation was also demonstrated with the methanol extracts of Astianthus viminalis, Brickellia paniculata, C. tepejilote and Justicia spicigera.

Uncertainties in monitoring of SVOCs in air caused by within-sampler degradation during active and passive air sampling

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Melymuk, Lisa; Bohlin-Nizzetto, Pernilla; Prokeš, Roman; Kukučka, Petr; Přibylová, Petra; Vojta, Šimon; Kohoutek, Jiří; Lammel, Gerhard; Klánová, Jana

2017-10-01

Degradation of semivolatile organic compounds (SVOCs) occurs naturally in ambient air due to reactions with reactive trace gases (e.g., ozone, NOx). During air sampling there is also the possibility for degradation of SVOCs within the air sampler, leading to underestimates of ambient air concentrations. We investigated the possibility of this sampling artifact in commonly used active and passive air samplers for seven classes of SVOCs, including persistent organic pollutants (POPs) typically covered by air monitoring programs, as well as SVOCs of emerging concern. Two active air samplers were used, one equipped with an ozone denuder and one without, to compare relative differences in mass of collected compounds. Two sets of passive samplers were also deployed to determine the influence of degradation during longer deployment times in passive sampling. In active air samplers, comparison of the two sampling configurations suggested degradation of particle-bound polycyclic aromatic hydrocarbons (PAHs), with concentrations up to 2× higher in the denuder-equipped sampler, while halogenated POPs did not have clear evidence of degradation. In contrast, more polar, reactive compounds (e.g., organophosphate esters and current use pesticides) had evidence of losses in the sampler with denuder. This may be caused by the denuder itself, suggesting sampling bias for these compounds can be created when typical air sampling apparatuses are adapted to limit degradation. Passive air samplers recorded up to 4× higher concentrations when deployed for shorter consecutive sampling periods, suggesting that within-sampler degradation may also be relevant in passive air monitoring programs.

Iota-carrageenan/chitosan/gelatin scaffold for the osteogenic differentiation of adipose-derived MSCs in vitro.

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Li, Junjie; Yang, Boguang; Qian, Yufeng; Wang, Qiyu; Han, Ruijin; Hao, Tong; Shu, Yao; Zhang, Yabin; Yao, Fanglian; Wang, Changyong

2015-10-01

In this study, we have developed ι-carrageenan/chitosan/gelatin (CCG) scaffold containing multiple functional groups (-NH2 , -OH, -COOH, and -SO3 H) to resemble the native extracellular matrix (ECM), using the ion-shielding technology and ultrasonic dispersion method. Fourier transform infrared spectroscopy (FTIR) of the CCG scaffolds suggests that the formation of CCG network involves electrostatic interactions between ι-carrageenan (ι-CA) and chitosan/gelatin, and the covalent cross-linking among amino groups of chitosan and/or gelatin. Scanning electron microscopic (SEM) observation reveals that the porous structure of scaffolds can be modulated by the ratio of ι-CA to chitosan/gelatin. The swelling ratio of the hydrogels increases as the ι-CA contents increase. Using differential scanning calorimetry, we found that the double helix structure of ι-CA is only stabilized at low contents of ι-CA in the CCG scaffolds (e.g., 5 wt %). The scaffolds containing 5% ι-CA showed the best protein adsorption capacity (4.46 ± 0.63 μg protein/mg scaffold) and elastic modulus (5.37 ± 1.03 MPa). In addition, the CCG scaffolds exhibit excellent support for adipose-derived mesenchymal stem cells (ADMSCs) attachment and proliferation, and they can improve the osteogenic differentiation and neovascularization capacities of ADMSCs. Overall, we conclude that the CCG may represent an ideal scaffold material for bone tissue engineering. © 2014 Wiley Periodicals, Inc.

Characterization of elasticity and hydration of composite hydrogel based on collagen-iota carrageenan as a corneal tissue engineering

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Rinawati, M.; Triastuti, J.; Pursetyo, K. T.

2018-04-01

The cornea is a refractive element of the eye that serves to continue the stimulation of light into the eye it has a clear, transparent, elastic and relatively thick tissue. Factors caused corneal blindness, are dystrophy, keratoconus, corneal scaring. Hydrogels can be made from polysaccharide derivatives that have gelation properties such as iota carrageenan. Therefore, it is a need to develop composite hydrogel based collagen-iota carragenan as an engineeried corneal tissue with high elasticity and hydration properties. Collagen hydrogel has a maximum water content an has equlibrium up to 40 %, less than the human cornea, 81 % and under normal hydration conditions, the human cornea can transmit 87 % of visible light. In addition, the refractive index on the surface of the cornea with air is 1.375-1.380. Based on this study, it is necessary to conduct research on the development and composition of hydrogel composite collagen-iota carrageen hydrogen based on. The best result was K5 (5:5) treatment, which has the equilibrium water content of 87.07 % and viscosity of 10.7346 Pa.s.

Land degradation causes and sustainable land management practices in southern Jordan

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Khresat, Saeb

2014-05-01

Jordan is one of the world's most water-deficit countries with only about 4% of the total land area considered arable. As a consequence agricultural production is greatly constrained by limited natural resources. Therefore, a major challenge for the country is to promote the sustainable use of natural resources for agricultural purposes. This challenge is being made harder by the ongoing processes of degradation due to increased population pressure, which undermine any social and economic development gains. In the southern plains of Jordan, sustainability of farming practices has worsened in the past three decades, exacerbating pressure on land and increasing land degradation processes. Non-sustainable land use practices include improper ploughing, inappropriate rotations, inadequate or inexistent management of plant residues, overgrazing of natural vegetation, random urbanization, land fragmentation and over-pumping of groundwater. The root cause is the high population growth which exerts excessive pressure on the natural resources to meet increased food and income demand. The poorest farmers who are increasingly growing cereals on marginal areas. Wheat and barley are now grown with little to no rotation, with no nutrient replenishment, and at places avoiding even fallow. Small landholding sizes and topographic features of the area tend to oblige longitudinal mechanized tillage operations along the slopes. Overall, the constraints facing the deprived land users such as, poor access to technology, capital and organization are the factors that lead into unsustainable practices. The main bottlenecks and barriers that hinder mainstreaming of sustainable land management in Jordan can be grouped into three main categories: (i) Knowledge, (ii) Institutional and Governance, and (iii) Economic and Financial. In this case study, the key challenge was to create a knowledge base among local stakeholders - including planners, extension officers, NGO/community leaders, teachers

Did Eucalyptus contribute to environment degradation? Implications from a dispute on causes of severe drought in Yunnan and Guizhou, China

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WenJun Zhang

2012-06-01

Full Text Available Various viewpoints were proposed to explain the causes of recent years' severe drought occurred in Yunnan and Guizhou, China. In general there are two parties of viewpoints, the Eucalyptus cause and climate change cause. I think Yunnan-Guizhou drought has been mainly caused by abnormal climate change. Eucalyptus was not significant in the formation of Yunnan-Guizhou drought. However, the forestation effect of Eucalyptus in China was not good. Environment quality and biodiversity in Eucalyptus plantation forests has been degrading in last decades. Enhancement of alleopathy of Eucalyptus trees under drought conditions would partly contribute to biodiversity reduction and environment degradation in Eucalyptus plantation forests. For existing Eucalyptus plantation forests of Yunnan, I suggest that some improvement measures should be adopted. Artificial weeding and cleaning in Eucalyptus plantation forests should be banned. Density of Eucalyptus trees needs to be reduced. Biodiversity should be artificially improved in Eucalyptus plantation forests. In the future, the mountains and lands with better vegetation cover must not be reclaimed for Eucalyptus planting. Eucalyptus plantation forests should be made in barren mountains and lands with poor biodiversity.

Fuzzy Clustering-Based Modeling of Surface Interactions and Emulsions of Selected Whey Protein Concentrate Combined to i-Carrageenan and Gum Arabic Solutions

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Gums and proteins are valuable ingredients with a wide spectrum of applications. Surface properties (surface tension, interfacial tension, emulsion activity index “EAI” and emulsion stability index “ESI”) of 4% whey protein concentrate (WPC) in a combination with '- carrageenan (0.05%, 0.1%, and 0.5...

Kinetics and mechanism of permanganate oxidation of iota- and lambda-carrageenan polysaccharides as sulfated carbohydrates in acid perchlorate solutions.

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Hassan, Refat M; Fawzy, Ahmed; Ahmed, Gamal A; Zaafarany, Ishaq A; Asghar, Basim H; Takagi, Hideo D; Ikeda, Yasuhisa

2011-10-18

The kinetics of oxidation of iota- and lambda-carrageenan as sulfated carbohydrates by permanganate ion in aqueous perchlorate solutions at a constant ionic strength of 2.0 mol dm(-3) have been investigated spectrophotometrically. The pseudo-first-order plots were found to be of inverted S-shape throughout the entire courses of reactions. The initial rates were found to be relatively slow in the early stages, followed by an increase in the oxidation rates over longer time periods. The experimental observations showed first-order dependences in permanganate and fractional first-order kinetics with respect to both carrageenans concentration for both the induction and autoacceleration periods. The results obtained at various hydrogen ion concentrations showed that the oxidation processes in these redox systems are acid-catalyzed throughout the two stages of oxidation reactions. The added salts lead to the prediction that Mn(III) is the reactive species throughout the autoacceleration periods. Kinetic evidence for the formation of 1:1 intermediate complexes was revealed. The kinetic parameters have been evaluated and tentative reaction mechanisms in good agreement with the kinetic results are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparative study on the effects of negatively-charged biopolymers on chitosan-based gels for the development of instantaneous gels

International Nuclear Information System (INIS)

Jimeno, Austin Ed B.; Chakraborty, Soma

2015-01-01

Polymeric electrolytic complexes are solutions of charged/ionized chains. These solutions of positive and negative charge can be combined to make instantaneous networks bonded by electrostatic interactions, a gel network. These electrostatic interaction allows for easy application in injectable gels as the network can be temporarily distributed with the application of force and reformed on the relief of it. Possible applications for these injectable gels include drug delivery and wound-healing. κ-Carrageenan, dextran sulfate, alginate, and chitosan are polyelectrolytic biocompatible polymers which are widely studied and used for a variety of biomedical applications. Gel networks are made by combining a negatively-charged (κ-Carrageenan, dextran sulfate, or alginate) and positively charged (chitosan) solutions. The strong electrostatic interaction between the opposite charges from the gel network and the inherent biocompatibility of the polymers allow future biomedical applications. Quat 188-modified chitosan has additional sites for electrostatic bonding, can be dissolved in neutral, basic, and acidic pH, and has shown inherent antibacterial activity. The objectives of this study are the following: to formulate chitosan-based gels mixing solutions of chitosan with solutions of either κ-Carrageenan, dextran sulfate, or alginate, study the gelation of the gels as function of time and pH (4, 7, and 9) using UV-Vis, characterize the chitosan-based gels through DSC and DMA, characterize the physiological degradation of the chitosan-based gels, and compare results with those from Quat 188-modified chitosan-based gels. Polyelectrolytic solutions of chitosan and negatively-charged biopolymer of similar viscosities were mixed. It was determined from the UV-Vis spectroscopy of the chitosan-carrageenan gels under pH7 buffer that the increase of concentration by a factor of 5 for 0.006M-0.0095M and 1.25 for 0.0095M-0.0150M Chitosan-Carrageenan gels improved gelation by the

Chitosan and Kappa-Carrageenan Vaginal Acyclovir Formulations for Prevention of Genital Herpes. In Vitro and Ex Vivo Evaluation

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María-Pilar Sánchez-Sánchez

2015-09-01

Full Text Available Vaginal formulations for the prevention of sexually transmitted infections are currently gaining importance in drug development. Polysaccharides, such as chitosan and carrageenan, which have good binding capacity with mucosal tissues, are now included in vaginal delivery systems. Marine polymer-based vaginal mucoadhesive solid formulations have been developed for the controlled release of acyclovir, which may prevent the sexual transmission of the herpes simplex virus. Drug release studies were carried out in two media: simulated vaginal fluid and simulated vaginal fluid/simulated seminal fluid mixture. The bioadhesive capacity and permanence time of the bioadhesion, the prepared compacts, and compacted granules were determined ex vivo using bovine vaginal mucosa as substrate. Swelling processes were quantified to confirm the release data. Biocompatibility was evaluated through in vitro cellular toxicity assays, and the results showed that acyclovir and the rest of the materials had no cytotoxicity at the maximum concentration tested. The mixture of hydroxyl-propyl-methyl-cellulose with chitosan- or kappa-carrageenan-originated mucoadhesive systems that presented a complete and sustained release of acyclovir for a period of 8–9 days in both media. Swelling data revealed the formation of optimal mixed chitosan/hydroxyl-propyl-methyl-cellulose gels which could be appropriated for the prevention of sexual transmission of HSV.

The anti-inflammatory effects of venlafaxine in the rat model of carrageenan-induced paw edema

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Valiollah Hajhashemi

2015-07-01

Full Text Available Objective(s:Recently anti-inflammatory effects of antidepressants have been demonstrated. Venlafaxine belongs to newer antidepressants with serotonin norepinephrine reuptake inhibition property. The pain alleviating properties of venlafaxine in different pain models such as neurogenic pain, diabetic neuropathy, and fibromyalgia have been demonstrated. Anti-inflammatory effects of venlafaxine and also its underlying mechanisms remain unclear. The present study was designed to evaluate the anti-inflammatory effects of venlafaxine and determine possible underlying mechanisms. Materials and Methods: We examined the anti-inflammatory effects of intraperitoneal (IP and intracerebroventricular (ICV administration of venlafaxine in the rat model of carrageenan-induced paw edema. Results: Our results showed that both IP (50 and 100 mg/kg and ICV (50 and 100 μg/rat injection of venlafaxine inhibited carrageenan-induced paw edema. Also IP and ICV administration of venlafaxine significantly decreased myeloperoxidase (MPO activity and interleukin (IL-1β and tumor necrosis factor (TNF-α production. Finally, we tried to reverse the anti-inflammatory effect of venlafaxine by yohimbine (5 mg/kg, IP, an alpha2-adrenergic antagonist. Our results showed that applied antagonist failed to change the anti-inflammatory effect of venlafaxine. Conclusion: These results demonstrated that venlafaxine has potent anti-inflammatory effect which is related to the peripheral and central effects of this drug. Also we have shown that anti-inflammatory effect of venlafaxine is mediated mostly through the inhibition of IL-1β and TNF-α production and decreases MPO activity in the site of inflammation.

Effects of intraplantar botulinum toxin-B on carrageenan-induced changes in nociception and spinal phosphorylation of GluA1 and Akt.

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Sikandar, Shafaq; Gustavsson, Ynette; Marino, Marc J; Dickenson, Anthony H; Yaksh, Tony L; Sorkin, Linda S; Ramachandran, Roshni

2016-07-01

Increasing evidence suggests that botulinum neurotoxins (BoNTs) delivered into the skin and muscle in certain human and animal pain states may exert antinociceptive efficacy though their uptake and transport to central afferent terminals. Cleavage of soluble N-methylaleimide-sensitive attachment protein receptor by BoNTs can impede vesicular mediated neurotransmitter release as well as transport/insertion of channel/receptor subunits into plasma membranes, an effect that can reduce activity-evoked facilitation. Here, we explored the effects of intraplantar botulinum toxin- B (BoNT-B) on peripheral inflammation and spinal nociceptive processing in an inflammatory model of pain. C57BL/6 mice (male) received unilateral intraplantar BoNT (1 U, 30 μL) or saline prior to intraplantar carrageenan (20 μL, 2%) or intrathecal N-methyl-D-aspartate (NMDA), substance P or saline (5 μL). Intraplantar carrageenan resulted in edema and mechanical allodynia in the injected paw and increased phosphorylation of a glutamate subunit (pGluA1ser845) and a serine/threonine-specific protein kinase (pAktser473) in spinal dorsal horn along with an increased incidence of spinal c-Fos positive cells. Pre-treatment with intraplantar BoNT-B reduced carrageenan evoked: (i) allodynia, but not edema; (ii) pGluA1 and pAkt and (iii) c-Fos expression. Further, intrathecal NMDA and substance P each increased dorsal horn levels of pGluA1 and pAkt. Intraplantar BoNT-B inhibited NMDA, but not substance P evoked phosphorylation of GluA1 and Akt. These results suggest that intraplantar toxin is transported centrally to block spinal activation and prevent phosphorylation of a glutamate receptor subunit and a kinase, which otherwise contribute to facilitated states. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Coercivity degradation caused by inhomogeneous grain boundaries in sintered Nd-Fe-B permanent magnets

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Chen, Hansheng; Yun, Fan; Qu, Jiangtao; Li, Yingfei; Cheng, Zhenxiang; Fang, Ruhao; Ye, Zhixiao; Ringer, Simon P.; Zheng, Rongkun

2018-05-01

Quantitative correlation between intrinsic coercivity and grain boundaries in three dimensions is critical to further improve the performance of sintered Nd-Fe-B permanent magnets. Here, we quantitatively reveal the local composition variation across and especially along grain boundaries using the powerful atomic-scale analysis technique known as atom probe tomography. We also estimate the saturation magnetization, magnetocrystalline anisotropy constant, and exchange stiffness of the grain boundaries on the basis of the experimentally determined structure and composition. Finally, using micromagnetic simulations, we quantify the intrinsic coercivity degradation caused by inhomogeneous grain boundaries. This approach can be applied to other magnetic materials for the analysis and optimization of magnetic properties.

Effect of some plant starches and carrageenan as fat substitutes in chicken patties.

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Das, S K; Prabhakaran, P; Tanwar, V K; Biswas, S

2015-07-01

This study evaluated the effect of different flours on the physicochemical, textural, and sensory properties of chicken patties. pH; cooking yield %; water holding capacity (WHC); proximate analysis (cooked); cholesterol content; and storage stability studies of control (Con) and sorghum flour (SF; 10%w/w), finger millet flour (FMF; 10%w/w), and carrageenan (Cgn; 0.5% w/w) treated chicken patties were observed in this study. Texture profile analysis (TPA) parameters like hardness, springiness, cohesiveness, gumminess, chewiness, and sensory parameters were estimated on cooked patties. Highly significant (P cooked); and no significant (P > 0.05) difference in pH, WHC, and protein % among control and treatments were noticed. Storage stability was dependent on treatments and storage periods. Significant difference (P 0.05) between Con and treatments.

Bixa Orellana L Leaf infusion as an Anti-inflammatory Agent in Carrageenan-induced Wistar Rats

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Sabrina Munggarani Yusuf

2014-08-01

Full Text Available Background: One of the characteristics of inflammation is swelling or edema. Inflammation can be treated with traditional medicine, such as Bixa orellana L. Bixa orellana L leaf contains flavonoid and tannin responsible for its anti-inflammatory effect. This study was conducted to analyse the ability of Bixa orellana L leaf infusion (BOLI to suppress paw edema in carrageenan-induced Wistar rats. Methods: This study was conducted in the Animal Laboratory of Department of Pharmacology and Therapy Faculty of Medicine Universitas Padjadjaran in October 2012. Bixa orellana L leaves were procured from Lembang, Bandung, and were botanically identified at the Herbarium of Universitas Padjadjaran, Jatinangor. Thirty female Wistar rats were randomly divided into five groups. Group 1 was given 5 mL aquades as a control, three groups received BOLI with 0,09 g; 0,18 g; and 0,36 g dosage respectively; and group 5 was given 0,9 mg diclofenac. At 1 hour after treatment, all rats were induced by carrageenan injection subcutaneously. Paw edema changes were quantified at 0, 1, 2, 3, 4, 5, 6, and 24 hour afterwards. Data were analysed using Kruskal-Wallis and Mann-Whitney test Results: Based on paw edema inhibition percentage, 0.18 g of BOLI was shown most effective (16.97% compared to 0.09 g (10.96% and 0.36 g (7.50%. Interestingly, no significant differences of anti-inflammatory effect were observed between groups that were treated with 0,18 g of BOLI and diclofenac (p > 0,005. Conclusions: The BOLI can suppress inflammation comparable to diclofenac. The effective dosage is 0.18 g/200 g BW/day.

Analysis of Soil Degradation Causes in Phyllostachys edulis Forests with Different Mulching Years

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Jiancheng Zhao

2018-03-01

Full Text Available Moso bamboo (Phyllostachys edulis (Carrière J.Houz. is famous for its fast growth and biomass accumulation, as well as high annual output for timber and bamboo shoots. Organic mulches are widely used to improve shoots’ production in moso bamboo forests. However, continuous mulching management may cause bamboo forest degradation and affect sustainable development. The objective of this study was to identify the degradation mechanism and to provide a theoretical basis for recovery. A complete randomized block design with four treatments was conducted, including mulching for one year (M1, two years (M2, three years (M3 and no-mulching management (NM. Soil nutrient contents, enzyme activities and microbial biomass were determined. With the increase of mulching years, the soil pH value gradually reduced, causing soil acidification, but the content of soil organic matter was inclined to ascend. Soil total nitrogen (TN, total phosphorus (TP and total potassium (TK contents showed an increasing trend, and they were significantly higher in mulching stands than those in NM (p < 0.05. Contents of soil available nutrients (AN, AP and AK increased, then decreased with the increase of mulching years and peaked in M1. With the increase of mulching years, the soil stoichiometry ratio (C/N, C/P and N/P gradually increased. Soil invertase, urease and acid phosphatase activities presented a single-peak curve and reached the maximum within one year after mulching. Total microbial biomass and that of individual groups changed greatly after mulching. Soil microbial biomass increased first and then decreased, and it was the largest in M1. The fungi:bacteria ratio decreased in the first year and then began to rise, while the aerobic:anaerobic ratio showed the opposite trend. According to the overall results, M3 leads to soil acidification, imbalance of the nutrients’ proportion, abnormal enzyme activity and change of soil microbial flora, and rotated mulching

Microscopic degradation mechanism of polyimide film caused by surface discharge under bipolar continuous square impulse voltage

International Nuclear Information System (INIS)

Luo Yang; Wu Guang-Ning; Liu Ji-Wu; Peng Jia; Gao Guo-Qiang; Zhu Guang-Ya; Wang Peng; Cao Kai-Jiang

2014-01-01

Polyimide (PI) film is an important type of insulating material used in inverter-fed motors. Partial discharge (PD) under a sequence of high-frequency square impulses is one of the key factors that lead to premature failures in insulation systems of inverter-fed motors. In order to explore the damage mechanism of PI film caused by discharge, an aging system of surface discharge under bipolar continuous square impulse voltage (BCSIV) is designed based on the ASTM 2275 01 standard and the electrical aging tests of PI film samples are performed above the partial discharge inception voltage (PDIV). The chemical bonds of PI polymer chains are analyzed through Fourier transform infrared spectroscopy (FTIR) and the dielectric properties of unaged and aged PI samples are investigated by LCR testers HIOKI 3532-50. Finally, the micro-morphology and micro-structure changes of PI film samples are observed through scanning electron microscopy (SEM). The results show that the physical and chemical effects of discharge cut off the chemical bonds of PI polymer chains. The fractures of ether bond (C—O—C) and imide ring (C—N—C) on the backbone of a PI polymer chain leads to the decrease of molecular weight, which results in the degradation of PI polymers and the generation of new chemical groups and materials, like carboxylic acid, ketone, aldehydes, etc. The variation of microscopic structure of PI polymers can change the orientation ability of polarizable units when the samples are under an AC electric field, which would cause the dielectric constant ε to increase and dielectric loss tan δ to decrease. The SEM images show that the degradation path of PI film is initiated from the surface and then gradually extends to the interior with continuous aging. The injection charge could result in the PI macromolecular chain degradation and increase the trap density in the PI polymer bulk. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Effect of ethamsylate on carrageenan-induced rat paw oedema: a comparison with indomethacin.

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Gard, P R; Trigger, D J

1990-12-01

1. Ethamsylate (diethylammonium 2,5-dihydroxybenzene sulfonate, Dicynene), a systemic haemostatic agent with an unknown mechanism of action, was tested for anti-inflammatory activity using the carrageenan-induced rat paw oedema test. 2. Ethamsylate was shown to be an effective anti-inflammatory agent with a time course and amplitude of effect similar to that of indomethacin, although the potency was only about 4% of that for indomethacin. 3. When ethamsylate and indomethacin were co-administered they did not show additive effects, suggesting that they do not share a common mode of action. It is proposed that ethamsylate, like indomethacin, may inhibit prostaglandin synthesis. Ulceration produced by indomethacin, it is suggested that it may prove to be a useful addition to, or replacement for, indomethacin in the treatment of inflammatory disorders.

Mild KCC2 hypofunction causes inconspicuous chloride dysregulation that degrades neural coding

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Nicolas eDoyon

2016-01-01

Full Text Available Disinhibition caused by Cl- dysregulation is implicated in several neurological disorders. This form of disinhibition, which stems primarily from impaired Cl- extrusion through the co-transporter KCC2, is typically identified by a depolarizing shift in GABA reversal potential (EGABA. Here we show, using computer simulations, that intracellular [Cl-] exhibits exaggerated fluctuations during transient Cl- loads and recovers more slowly to baseline when KCC2 level is even modestly reduced. Using information theory and signal detection theory, we show that increased Cl- lability and settling time degrade neural coding. Importantly, these deleterious effects manifest after less KCC2 reduction than needed to produce the gross changes in EGABA required for detection by most experiments, which assess KCC2 function under weak Cl- load conditions. By demonstrating the existence and functional consequences of occult Cl- dysregulation, these results suggest that modest KCC2 hypofunction plays a greater role in neurological disorders than previously believed.

Modelling land degradation in IMAGE 2

NARCIS (Netherlands)

Hootsmans RM; Bouwman AF; Leemans R; Kreileman GJJ; MNV

2001-01-01

Food security may be threatened by loss of soil productivity as a result of human-induced land degradation. Water erosion is the most important cause of land degradation, and its effects are irreversible. This report describes the IMAGE land degradation model developed for describing current and

C1q protein binds to the apoptotic nucleolus and causes C1 protease degradation of nucleolar proteins.

Science.gov (United States)

Cai, Yitian; Teo, Boon Heng Dennis; Yeo, Joo Guan; Lu, Jinhua

2015-09-11

In infection, complement C1q recognizes pathogen-congregated antibodies and elicits complement activation. Among endogenous ligands, C1q binds to DNA and apoptotic cells, but whether C1q binds to nuclear DNA in apoptotic cells remains to be investigated. With UV irradiation-induced apoptosis, C1q initially bound to peripheral cellular regions in early apoptotic cells. By 6 h, binding concentrated in the nuclei to the nucleolus but not the chromatins. When nucleoli were isolated from non-apoptotic cells, C1q also bound to these structures. In vivo, C1q exists as the C1 complex (C1qC1r2C1s2), and C1q binding to ligands activates the C1r/C1s proteases. Incubation of nucleoli with C1 caused degradation of the nucleolar proteins nucleolin and nucleophosmin 1. This was inhibited by the C1 inhibitor. The nucleoli are abundant with autoantigens. C1q binding and C1r/C1s degradation of nucleolar antigens during cell apoptosis potentially reduces autoimmunity. These findings help us to understand why genetic C1q and C1r/C1s deficiencies cause systemic lupus erythematosus. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Anti-inflammatory activity of Achillea and Ruscus topical gel on carrageenan-induced paw edema in rats.

Science.gov (United States)

Maswadeh, Hamzah M; Semreen, Mohammad H; Naddaf, Ahmad R

2006-01-01

The anti-inflammatory activity of Achillea and Ruscus extracts was studied in comparison with diclofenac sodium topical gel (diclosal Emulgel), using the carrageenan induced paw edema model in Albino rats. Gel formulation was prepared containing 6% of each extract in gel base, namely sodium carboxymethylcellulose (NaCMC). The kinetics of drug release from the prepared formulation was studied separately in each case. Results showed that the release follows the Higuchi square root equation. The pharmacological screening revealed that the percent reduction of edema for Achillea extract and Ruscus extract were 48.1% and 18.8%, respectively, while diclosal Emulgel produced 47% reduction of edema.

STRUCTURAL PERFORMANCE OF DEGRADED REINFORCED CONCRETE MEMBERS

International Nuclear Information System (INIS)

Braverman, J.I.; Miller, C.A.; Ellingwood, B.R.; Naus, D.J.; Hofmayer, C.H.; Bezler, P.; Chang, T.Y.

2001-01-01

This paper describes the results of a study to evaluate, in probabilistic terms, the effects of age-related degradation on the structural performance of reinforced concrete members at nuclear power plants. The paper focuses on degradation of reinforced concrete flexural members and shear walls due to the loss of steel reinforcing area and loss of concrete area (cracking/spalling). Loss of steel area is typically caused by corrosion while cracking and spalling can be caused by corrosion of reinforcing steel, freeze-thaw, or aggressive chemical attack. Structural performance in the presence of uncertainties is depicted by a fragility (or conditional probability of failure). The effects of degradation on the fragility of reinforced concrete members are calculated to assess the potential significance of various levels of degradation. The fragility modeling procedures applied to degraded concrete members can be used to assess the effects of degradation on plant risk and can lead to the development of probability-based degradation acceptance limits

Abscisic acid-regulated protein degradation causes osmotic stress-induced accumulation of branched-chain amino acids in Arabidopsis thaliana.

Science.gov (United States)

Huang, Tengfang; Jander, Georg

2017-10-01

Whereas proline accumulates through de novo biosynthesis in plants subjected to osmotic stress, leucine, isoleucine, and valine accumulation in drought-stressed Arabidopsis thaliana is caused by abscisic acid-regulated protein degradation. In response to several kinds of abiotic stress, plants greatly increase their accumulation of free amino acids. Although stress-induced proline increases have been studied the most extensively, the fold-increase of other amino acids, in particular branched-chain amino acids (BCAAs; leucine, isoleucine, and valine), is often higher than that of proline. In Arabidopsis thaliana (Arabidopsis), BCAAs accumulate in response to drought, salt, mannitol, polyethylene glycol, herbicide treatment, and nitrogen starvation. Plants that are deficient in abscisic acid signaling accumulate lower amounts of BCAAs, but not proline and most other amino acids. Previous bioinformatic studies had suggested that amino acid synthesis, rather than protein degradation, is responsible for the observed BCAA increase in osmotically stressed Arabidopsis. However, whereas treatment with the protease inhibitor MG132 decreased drought-induced BCAA accumulation, inhibition of BCAA biosynthesis with the acetolactate synthase inhibitors chlorsulfuron and imazapyr did not. Additionally, overexpression of BRANCHED-CHAIN AMINO ACID TRANSFERASE2 (BCAT2), which is upregulated in response to osmotic stress and functions in BCAA degradation, decreased drought-induced BCAA accumulation. Together, these results demonstrate that BCAA accumulation in osmotically stressed Arabidopsis is primarily the result of protein degradation. After relief of the osmotic stress, BCAA homeostasis is restored over time by amino acid degradation involving BCAT2. Thus, drought-induced BCAA accumulation is different from that of proline, which is accumulated due to de novo synthesis in an abscisic acid-independent manner and remains elevated for a more prolonged period of time after removal of

Polyethylenimine/kappa carrageenan: Micro-arc oxidation coating for passivation of magnesium alloy.

Science.gov (United States)

Golshirazi, A; Kharaziha, M; Golozar, M A

2017-07-01

The aim of this study was to combine micro-arc oxidation (MAO) and self-assembly technique to improve corrosion resistivity of AZ91 alloy. While a silicate-fluoride electrolyte was adopted for MAO treatment, polyethylenimine (PEI)/kappa carrageenan (KC) self-assembly coating was applied as the second coating layer. Resulted demonstrated the formation of forsterite-fluoride containing MAO coating on AZ91 alloy depending on the voltage and time of anodizing process. Addition of the second PEI/KC coating layer on MAO treated sample effectively enhanced the adhesive strength of MAO coated sample due to filling the pores with polymers and increase in the mechanical interlocking of coating to the substrate. Moreover, the corrosion evaluation considered by potentiodynamic polarization and electrochemical impedance spectroscopy confirmed that double layered PEI/KC:MAO coating presented superior resistance to corrosion attack. It is envisioned that the proposed double layered PEI/KC:MAO coating could be useful for biomedical applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Release of Tenofovir from Carrageenan-Based Vaginal Suppositories

Directory of Open Access Journals (Sweden)

Toral Zaveri

2014-07-01

Full Text Available Microbicides are an active area of research for HIV prevention, being developed as a woman-initiated method of prevention during unprotected coitus. Along with safety and efficacy, assessing and improving compliance is a major area of research in microbicide development. We have produced microbicide prototypes in the form of semisoft vaginal suppositories prepared from carrageenan and conducted both qualitative and quantitative studies using these prototypes to determine the physical properties that drive acceptability and possibly adherence. In order to ensure that the suppositories function as effective drug delivery vehicles, we have conducted in vitro dissolution studies in water, vaginal simulant fluid (VSF and semen simulant fluid (SSF with suppositories loaded with the antiretroviral drug, tenofovir (TFV. TFV was released via diffusion and matrix erosion in water or by diffusion out of the matrix in VSF and SSF. Diffusion studies were conducted in two different volumes of VSF and SSF. The volume of VSF/SSF into which TFV diffused and the size of the suppositories determined the rate of diffusion from the suppositories. About 45%–50% of the encapsulated TFV diffused out of the suppositories within the first two hours, irrespective of suppository size, diffusion medium (VSF/SSF and the volume of medium. Prior work indicates that a short waiting period between insertion and coitus is highly desired by women; present data suggest our microbicide prototypes have rapid initial release followed by a slow release curve over the first 24 h.

Corrigendum to “Rheological properties of agar and carrageenan from Ghanaian red seaweeds” [Food Hydrocolloids 63 (2017) 50–58

DEFF Research Database (Denmark)

Rhein-Knudsen, Nanna; Ale, Marcel Tutor; Ajalloueian, Fatemeh

2018-01-01

. G., Penninkhof, B., Rudolph, B., & De Ruiter, G. A. (1999). A novel high-performance anion-exchange chromatographic method for the analysis of carrageenans and agars containing 3,6-anhydrogalactose. Analytical Biochemistry, 268, 213-222. Table 3 Overview of seaweed type (hydrocolloid source......), hydrocolloid extraction method (direct water-extraction or after alkali treatment), hydrocolloid and monomer1 yields, and sulfate levels [data given as means ± SD]. Different roman superscript letters indicate significant differences (P agar yields, monosaccharides...

Evaluation and selection of indicators for land degradation and desertification monitoring: types of degradation, causes, and implications for management.

Science.gov (United States)

Kairis, Or; Kosmas, C; Karavitis, Ch; Ritsema, C; Salvati, L; Acikalin, S; Alcalá, M; Alfama, P; Atlhopheng, J; Barrera, J; Belgacem, A; Solé-Benet, A; Brito, J; Chaker, M; Chanda, R; Coelho, C; Darkoh, M; Diamantis, I; Ermolaeva, O; Fassouli, V; Fei, W; Feng, J; Fernandez, F; Ferreira, A; Gokceoglu, C; Gonzalez, D; Gungor, H; Hessel, R; Juying, J; Khatteli, H; Khitrov, N; Kounalaki, A; Laouina, A; Lollino, P; Lopes, M; Magole, L; Medina, L; Mendoza, M; Morais, P; Mulale, K; Ocakoglu, F; Ouessar, M; Ovalle, C; Perez, C; Perkins, J; Pliakas, F; Polemio, M; Pozo, A; Prat, C; Qinke, Y; Ramos, A; Ramos, J; Riquelme, J; Romanenkov, V; Rui, L; Santaloia, F; Sebego, R; Sghaier, M; Silva, N; Sizemskaya, M; Soares, J; Sonmez, H; Taamallah, H; Tezcan, L; Torri, D; Ungaro, F; Valente, S; de Vente, J; Zagal, E; Zeiliguer, A; Zhonging, W; Ziogas, A

2014-11-01

Indicator-based approaches are often used to monitor land degradation and desertification from the global to the very local scale. However, there is still little agreement on which indicators may best reflect both status and trends of these phenomena. In this study, various processes of land degradation and desertification have been analyzed in 17 study sites around the world using a wide set of biophysical and socioeconomic indicators. The database described earlier in this issue by Kosmas and others (Environ Manage, 2013) for defining desertification risk was further analyzed to define the most important indicators related to the following degradation processes: water erosion in various land uses, tillage erosion, soil salinization, water stress, forest fires, and overgrazing. A correlation analysis was applied to the selected indicators in order to identify the most important variables contributing to each land degradation process. The analysis indicates that the most important indicators are: (i) rain seasonality affecting water erosion, water stress, and forest fires, (ii) slope gradient affecting water erosion, tillage erosion and water stress, and (iii) water scarcity soil salinization, water stress, and forest fires. Implementation of existing regulations or policies concerned with resources development and environmental sustainability was identified as the most important indicator of land protection.

Characterization of thermostable cellulase produced by Bacillus strains isolated from solid waste of carrageenan

Science.gov (United States)

Listyaningrum, N. P.; Sutrisno, A.; Wardani, A. K.

2018-03-01

Cellulase-producing bacteria was isolated from solid waste of carrageenan and identified as Bacillus licheniformis C55 by 16S rRNA sequencing. The optimum condition for cellulase production was obtained at pH and temperature of 8.0 and 50°C, respectively in a medium containing glucose as carbon source and 1.0% carboxymethyl cellulose (CMC) to stimulate the cellulase production. Most remarkably, the enzyme retained its relative activity over 50% after incubation at 50°C for 90 minutes. Substrate specificity suggested that the enzyme is an endoglucanase. The molecular mass of Bacillus licheniformis C55 crude cellulase was found about 18 kDa by SDS-PAGE analysis. This thermostable enzyme would facilitate development of more efficient and cost-effective forms of the process to convert lignocellulosic biomass into high-value products.

Investigation of Stress Concentration and Casing Strength Degradation Caused by Corrosion Pits

Directory of Open Access Journals (Sweden)

Wei Yan

2016-01-01

Full Text Available Downhole casing and tubing are subjected to corrosion in many cases because of the exposure to corrosive environment. A more serious problem is that pitting corrosion occurs in the casing inner surface. Meanwhile, downhole strings are subjected to various forms of mechanical loads, for example, internal pressure load, external collapse load, or both. These loads acting on the corrosion pits will cause stress concentration and degrade the casing strength. Thus, it is essential to evaluate the stress concentration degree reasonably. The SCF (stress concentration factor is usually used to characterize the degree of stress concentration induced by corrosion pits. This paper presented a comparison on the SCFs regarding the analytical method for a single pit and experimental method for double pits. The results show that the SCF of a single pit depends mainly on the depth of the corrosion pit; however, the SCF of the double pits strongly depends on the pits distance. A correction factor of 1.3 was recommended in the double pits SCF prediction model.

Quality evaluation of probiotic capsule prepared from alginate, carrageenan and tofu waste flour based on bacterial activity and organoleptic test

Science.gov (United States)

Muhardina, V.; Ermaya, D.; Aisyah, Y.; Haryani, S.

2018-02-01

Probiotic capsule is an innovation in functional food sector. It is used to preserve the living cells of probiotic bacteria during processing and storage. In this research, the improvement of probiotic viability is studied by using two kinds of encapsulating biomaterials and different concentration of tofu waste flour. Extrusion is selected method for encapsulation process. The purpose of this study is to examine the quality of probiotic capsule by evaluating the lactic acid bacteria performance and its physical characteristic. The article provides the data of probiotic bacteria activity related to their living cells present in capsule, activity in fermentation media compare to uncapsulated bacteria, and panelists’ preferences of capsule’s physical properties. The data is analyzed statistically by using ANOVA. The result shows that variables in this study affect the number of bacteria, their metabolic activity in producing acid during fermentation, and physical appearance of the capsule. Combination of alginate and tofu waste flour allows the multiplication of bacteria to a high number, and forms elastic, yellow and cloudy capsule, while with carrageenan, it causes the growth of a few numbers of bacteria which affects to a moderate pH and produces elastic, creamy and transparent capsule.

Preventive Effect of Aspirin Eugenol Ester on Thrombosis in κ-Carrageenan-Induced Rat Tail Thrombosis Model.

Directory of Open Access Journals (Sweden)

Ning Ma

Full Text Available Based on the prodrug principle, aspirin eugenol ester (AEE was synthesized, which can reduce the side effects of aspirin and eugenol. As a good candidate for new antithrombotic and anti-inflammatory medicine, it is essential to evaluate its preventive effect on thrombosis. Preventive effect of AEE was investigated in κ-carrageenan-induced rat tail thrombosis model. AEE suspension liquids were prepared in 0.5% sodium carboxymethyl cellulose (CMC-Na. AEE was administrated at the dosage of 18, 36 and 72 mg/kg. Aspirin (20 mg/kg, eugenol (18 mg/kg and 0.5% CMC-Na (30 mg/kg were used as control drug. In order to compare the effects between AEE and its precursor, integration of aspirin and eugenol group (molar ratio 1:1 was also designed in the experiment. After drugs were administrated intragastrically for seven days, each rat was injected intraperitoneally with 20 mg/kg BW κ-carrageen dissolved in physiological saline to induce thrombosis. The length of tail-thrombosis was measured at 24 and 48 hours. The blank group just was given physiological saline for seven days without κ-carrageenan administrated. The results indicated that AEE significantly not only reduced the average length of thrombus, PT values and FIB concentration, but also reduced the red blood cell (RBC, hemoglobin (HGB, hematocrit (HCT and platelet (PLT. The effects of AEE on platelet aggregation and anticoagulant in vitro showed that AEE could inhibit adenosine diphosphate (ADP-induced platelet aggregation as dose-dependence but no notable effect on blood clotting. From these results, it was concluded that AEE possessed positive effect on thrombosis prevention in vivo through the reduction of FIB, PLT, inhibition of platelet aggregation and the change of TT and PT values.

How does external feedback cause AlGaAs-based diode lasers to degrade?

DEFF Research Database (Denmark)

Hempel, Martin; Chi, Mingjun; Petersen, Paul Michael

2013-01-01

The effect of external feedback on the degradation of 808 nm emitting AlGaAs-based high-power broad-area diode lasers is studied. For this purpose, early stages of gradual degradation are induced by accelerated aging at high power levels. While the quantum well that actually experiences the highest...... total optical load remains unaffected, severe impact by point defects is observed on the cladding layers and the waveguide. Extended defects such as dislocations, however, are not observed in such early stages of degradation, which are accompanied by gradual power loss of a few percent only....

Analysis of accelerated degradation of a HT-PEM fuel cell caused by cell reversal in fuel starvation condition

DEFF Research Database (Denmark)

Zhou, Fan; Andreasen, Søren Juhl; Kær, Søren Knudsen

2015-01-01

This paper reports an accelerated degradation test of a high temperature PEM fuel cell under repeated H2 starvation condition. The H2 stoichiometry is cycled between 3.0 and 0.8 every 2 min during the test. The experimental results show that the polarity of the fuel cell is reversed under H2......, there is only a slight decrease in open circuit voltage of the fuel cell which implies the membrane is not affected by the test. The electrochemical impedance spectrum measurement shows that the H2 starvation can cause significant increase in the ohmic resistance and charge transfer resistance. By looking...... starvation condition, and the cell performance indicated by cell voltage at H2 stoichiometry of 3.0 declines from 0.59 V to 0.41 V in 19 cycles. Since CO2 is detected in anode exhaust under H2 starvation condition, carbon corrosion is believed to be the reason for the degradation in this test. After the test...

Carbon emissions from tropical forest degradation caused by logging

International Nuclear Information System (INIS)

Pearson, Timothy R H; Brown, Sandra; Casarim, Felipe M

2014-01-01

The focus of land-use related efforts in developing countries to reduce carbon emissions has been on slowing deforestation, yet international agreements are to reduce emissions from both deforestation and forest degradation (REDD). The second ‘D’ is poorly understood and accounted for a number of technical and policy reasons. Here we introduce a complete accounting method for estimating emission factors from selective timber harvesting, a substantial form of forest degradation in many tropical developing countries. The method accounts separately for emissions from the extracted log, from incidental damage to the surrounding forest, and from logging infrastructure, and emissions are expressed as units of carbon per cubic meter of timber extracted to allow for simple application to timber harvesting statistics. We applied the method in six tropical countries (Belize, Bolivia, Brazil, Guyana, Indonesia, and Republic of Congo), resulting in total emission factors of 0.99−2.33 Mg C m −3 . In all cases, emissions were dominated by damage to surrounding vegetation and the infrastructure rather than the logs themselves, and total emissions represented about 3–15% of the biomass carbon stocks of the associated unlogged forests. We then combined the emission factors with country level logging statistics for nine key timber producing countries represented by our study areas to gain an understanding of the order of magnitude of emissions from degradation compared to those recently reported for deforestation in the same countries. For the nine countries included, emissions from logging were on average equivalent to about 12% of those from deforestation. For those nine countries with relatively low emissions from deforestation, emissions from logging were equivalent to half or more of those from deforestation, whereas for those countries with the highest emissions from deforestation, emissions from logging were equivalent to <10% of those from deforestation

Cavity-mirror degradation in the deep-UV FEL

Energy Technology Data Exchange (ETDEWEB)

Yamada, K.; Yamazaki, T.; Sei, N. [Electrotechnical Lab., Ibaraki (Japan)] [and others

1995-12-31

It is known that the degradation of dielectric multilayer mirrors used in short wavelength free-electron lasers (FELs) is caused by the carbon contamination on the mirror surface and the defects inside the dielectrics. We reported last year that the degraded dielectric multilayer mirrors can be repaired with both surface treatment by RF-induced oxygen plasma and thermal annealing. However, such a mirror degradation is still one of the most critical issues in the deep ultraviolet (UV) FELs, because the fundamental undulator radiation resonating in the laser cavity, the intensity of which is much higher than that of higher harmonics, can be sufficiently energetic to cause the mirror degradation through photochemical reactions. We are investigating the mirror degradation mainly in the deep UV region down to 240 nm. The experimental results will be shown. The mirror degradation mechanism will be discussed.

Study on the friction of κ-carrageenan hydrogels in air and aqueous environments.

Science.gov (United States)

Kozbial, Andrew; Li, Lei

2014-03-01

Understanding the friction mechanism of polysaccharide hydrogels, which is the key component of human cartilage that has very low friction coefficient, is critical to develop next generation artificial joint replacement materials. In this study, the friction of the polysaccharide κ-carrageenan hydrogel was investigated to elucidate the effect of external load, cross-linking density, velocity, and environment on friction. Our experimental results show that (1) coefficient of friction (COF) decreases with normal load in air and remains constant in water, (2) increasing cross-linking density concurrently increases friction and is proportional to Young's modulus, (3) COF increases with testing velocity in both air and water, and (4) friction is reduced in aqueous environment due to the lubricating effect of water. The underlying frictional mechanism is discussed on the basis of water transport from bulk to surface and a previously proposed "repulsion-adsorption" model. Copyright © 2013 Elsevier B.V. All rights reserved.

Chiroplasmonic magnetic gold nanocomposites produced by one-step aqueous method using κ-carrageenan.

Science.gov (United States)

Lesnichaya, Marina V; Sukhov, Boris G; Aleksandrova, Galina P; Gasilova, Ekaterina R; Vakul'skaya, Tamara I; Khutsishvili, Spartak S; Sapozhnikov, Anatoliy N; Klimenkov, Igor V; Trofimov, Boris A

2017-11-01

Novel water-soluble chiroplasmonic nanobiocomposites with directly varied gold content were synthesized by a one-step redox method in water using a biocompatible polysaccharide κ-carrageenan (industrial product from algae) as both reducing and stabilizing matrix. The influence of the reactants ratio, temperature, and pH on the reaction was studied and the optimal reaction parameters were found. The structure and the properties of composite nanomaterials were examined in solid state and aqueous solutions by using complementary physical-chemical methods X-ray diffraction analysis, transmission electron microscopy, spectroscopy of electron paramagnetic resonance, atomic absorption and optical spectroscopy, polarimetry including optical rotatory dispersion with registration of interphase-crossbred Cotton effect of a chiral polysaccharide matrix on plasmonic chromophore of gold nanoparticles, dynamic and static light scattering. The new perspective multi-purpose nanocomposites demonstrate a complex of chiroplasmonic and magnetic properties, imparted by both nanoparticles and radicals enriched chiral polysaccharide matrix. Copyright © 2017 Elsevier Ltd. All rights reserved.

Improvement of Emulsifying Properties of Wheat Gluten Hydrolysate λ-Carrageenan Conjugates

Directory of Open Access Journals (Sweden)

Jin-Shui Wang

2006-01-01

Full Text Available Gluten hydrolysate was prepared through limited enzymatic hydrolysis of wheat gluten resulting from the byproducts of wheat starch. The enzyme applied in the present study was Protamex. Response surface methodology was used to investigate the effects of pH, gluten hydrolysate (GHPλ-carrageenan (C ratio and reaction time on emulsifying properties of the GHP-C conjugate. The regression model for emulsion activity index (EAI was significant at p=0.001, while reaction time had a significant effect on EAI of the conjugate with regression coefficient of 4.25. The interactions of pH and GHP/ C ratio, and GHP/C ratio and reaction time significantly affected the EAI of the conjugate. Both the emulsifying property and nitrogen solubility index (NSI of GHP-C conjugate prepared under the optimal conditions increased more remarkably, compared to the control. The denaturation temperature of GHP-C conjugate obviously increased compared to wheat gluten. The addition of GHP-C conjugate had different effects on dough characteristics. Moreover, this conjugate can delay the increase in the bread crumb firmness during storage. It demonstrated that this conjugate couldimprove the dough characteristics and had anti-staling properties of bread.

Operationalizing measurement of forest degradation

DEFF Research Database (Denmark)

Dons, Klaus; Smith-Hall, Carsten; Meilby, Henrik

2015-01-01

. In Tanzania, charcoal production is considered a major cause of forest degradation, but is challenging to quantify due to sub-canopy biomass loss, remote production sites and illegal trade. We studied two charcoal production sites in dry Miombo woodland representing open woodland conditions near human......Quantification of forest degradation in monitoring and reporting as well as in historic baselines is among the most challenging tasks in national REDD+ strategies. However, a recently introduced option is to base monitoring systems on subnational conditions such as prevalent degradation activities...

Kaempferol attenuates COX-2 expression in IL-6-induced macrophages and carrageenan-induced mouse paw edema by targeting STAT3 and NF-kB

Directory of Open Access Journals (Sweden)

Anandita Basu

2017-10-01

Full Text Available Dietary polyphenols are reported to possess varied pharmacological activities, viz. antioxidant, anti-inflammatory, anti-cancer, anti-allergic actions. Here, we report the efficacy of Kaempferol (kae to attenuate expression of IL-6 induced cycloxygenase-2 (COX-2, an inducible isoform of cycloxygenase enzyme family that catalyzes synthesis of inflammatory mediators, prostanoids and prostaglandins. IL-6 is a pleiotropic cytokine involved in both acute and chronic inflammation. Our results showed that kae attenuated COX-2 expression at both mRNA and protein level in IL-6-induced THP1 macrophages. This attenuation of COX-2 expression by kae involved dose-dependent inhibition of phosphorylation of STAT3 (Tyr 705 and NF-kB p65 (Ser 536 leading to their deactivation and reduced nuclear localization in THP-1 macrophages. Moreover, kae modulates COX-2 expression as well as STAT3 and NF-kB activation in carrageenan-induced mouse paw edema model. RT-PCR and western blot analysis from paw tissues were harvested after kae injection (i.p followed by carrageenan-treatment in sub-plantar region of right hind paw. Results showed that kae attenuated COX-2 expression and STAT3 and NF-kB activation in carrageenan-induced mouse paw edema, suggesting that inhibition of both IL-6-STAT3-COX-2 and IL-6-NFkB-COX-2 axes by kae might be stimulus-independent. To understand binding affinity of kae with NF-kB and STAT3, docking analysis was performed using Patchdock server. From our findings, we observed strong binding affinity and transient interaction in both NF-kB/kae and STAT3/kae complexes. We noticed negative atomic contact energy and greater interface area for both the complexes. Selected complexes obtained from Patchdock were refined using Firedock online server which also suggested similar negative binding energy profile. It is plausible that kae attenuates COX-2 expression by directly binding to both STAT3 and NF-kB proteins and inhibiting their activation and

Casein Kinase 1α Mediates the Degradation of Receptors for Type I and Type II Interferons Caused by Hemagglutinin of Influenza A Virus.

Science.gov (United States)

Xia, Chuan; Wolf, Jennifer J; Vijayan, Madhuvanthi; Studstill, Caleb J; Ma, Wenjun; Hahm, Bumsuk

2018-04-01

Although influenza A virus (IAV) evades cellular defense systems to effectively propagate in the host, the viral immune-evasive mechanisms are incompletely understood. Our recent data showed that hemagglutinin (HA) of IAV induces degradation of type I IFN receptor 1 (IFNAR1). Here, we demonstrate that IAV HA induces degradation of type II IFN (IFN-γ) receptor 1 (IFNGR1), as well as IFNAR1, via casein kinase 1α (CK1α), resulting in the impairment of cellular responsiveness to both type I and II IFNs. IAV infection or transient HA expression induced degradation of both IFNGR1 and IFNAR1, whereas HA gene-deficient IAV failed to downregulate the receptors. IAV HA caused the phosphorylation and ubiquitination of IFNGR1, leading to the lysosome-dependent degradation of IFNGR1. Influenza viral HA strongly decreased cellular sensitivity to type II IFNs, as it suppressed the activation of STAT1 and the induction of IFN-γ-stimulated genes in response to exogenously supplied recombinant IFN-γ. Importantly, CK1α, but not p38 MAP kinase or protein kinase D2, was proven to be critical for HA-induced degradation of both IFNGR1 and IFNAR1. Pharmacologic inhibition of CK1α or small interfering RNA (siRNA)-based knockdown of CK1α repressed the degradation processes of both IFNGR1 and IFNAR1 triggered by IAV infection. Further, CK1α was shown to be pivotal for proficient replication of IAV. Collectively, the results suggest that IAV HA induces degradation of IFN receptors via CK1α, creating conditions favorable for viral propagation. Therefore, the study uncovers a new immune-evasive pathway of influenza virus. IMPORTANCE Influenza A virus (IAV) remains a grave threat to humans, causing seasonal and pandemic influenza. Upon infection, innate and adaptive immunity, such as the interferon (IFN) response, is induced to protect hosts against IAV infection. However, IAV seems to be equipped with tactics to evade the IFN-mediated antiviral responses, although the detailed

Models of Inflammation: Carrageenan- or Complete Freund's Adjuvant (CFA)-Induced Edema and Hypersensitivity in the Rat.

Science.gov (United States)

McCarson, Kenneth E

2015-09-01

Animal models of inflammation are used to assess the production of inflammatory mediators at sites of inflammation, the processing of pain sensation at CNS sites, the anti-inflammatory properties of agents such as nonsteroidal anti-inflammatory drugs (NSAIDs), and the efficacy of putative analgesic compounds in reversing cutaneous hypersensitivity. Detailed in this unit are methods to elicit and measure carrageenan- and complete Freund's adjuvant (CFA)-induced cutaneous inflammation. Due to possible differences between the dorsal root sensory system and the trigeminal sensory system, injections into either the footpad or vibrissal pad are described. In this manner, cutaneous inflammation can be assessed in tissue innervated by the lumbar dorsal root ganglion neurons (footpad) or by the trigeminal ganglion neurons (vibrissal pad). Copyright © 2015 John Wiley & Sons, Inc.

Preparation and in vitro evaluation of carboxymethylated κ-carrageenan aluminum hydrogel microbeads for prolonged release of mefenamic acid

International Nuclear Information System (INIS)

Beron, Pia Maria G.; Cruzado, Shervin T.; Dela Cruz, Sharmaine F.; Estanislao, Fides Mae L.; Evangelista, Charina Joy; Mandocdoc, Larra Minnellie W.; Salas, Sharlaine B.; Tiu, Mark Brian C.; Carigma, Andrea Q.; Bayquen, Aristea V.

2012-01-01

Polymers that swell in an aqueous medium have been widely used to formulate controlled-release dosage forms. This study aims to prepare carboxymethyl κ-carrageenan (CMKC) microbeads and evaluate its potential for controlled release of mefenamic acid in comparison to the positive control, carboxymethylcellulose (CMC) microbeads. The powdered κ-carrageenan was carboxymethylated and Fourier-Transform Infrared Spectroscopy confirmed the carboxy methylation. Aqueous solutions of CMC (3% w/v) and CMKC (3%, 4%, 5% w/v) were prepared as microbeads using ionotropic gelation technique. Microbeads were loaded with mefenamic acid by suspending it in the aqueous solution (0.5% w/v) of the drug for 72 hours. Particle size and surface morphology were characterized using scanning electron microscopy. One-way ANOVA was used to determine a significant difference between the release activity of the drug-loaded CMKC and CMC microbeads. Differential Scanning Calorimetry was performed on the drug, drug- free, and drug-loaded microbeads of CMC and CMKC. Two-way ANOVARM showed significant interaction in % drug release of the three groups being analyzed in respect to time effect (p≤0.001) and group effect (p≤0.001). Post Hoc Duncan Multiple Range Test showed that 3% CMC and 4% CMKC has equal average % drug release values and is significantly higher compared to the commercial mefenamic acid. Also, one way ANOVA showed that 3% CMC was able to release the drug with no significant difference in time (p = 0.159), while 4% CMKC (p < 0.001) and the commercial mefenamic acid (p≤0.001) were able to release the drug with significant difference in time (author)

Radiation processing of natural polymers for industrial and agricultural applications

International Nuclear Information System (INIS)

Hegazy, El-Sayed A.; AbdEl-Rehim, H.; Diaa, D.A.; El-Barbary, A.

2008-01-01

Radiation induced degradation technology is a new and promising application of ionizing radiation to develop viscose, pulp, paper, food preservation, pharmaceutical production, and natural bioactive agents industries. Controlling the degree of degradation, uniform molecular weight distribution, saving achieved in the chemicals (used in conventional methods) on a cost basis, and environmentally friendly process are the beneficial effects of using radiation technology in these industries. However, for some development countries such technology is not economic. Therefore, a great efforts should be done to reduce the cost required for such technologies. One of the principle factors for reducing the cost is achieving the degradation at low irradiation doses. The addition of some additives such as potassium per-sulfate (KPS), ammonium per-sulfate (APS), or H 2 O 2 to natural polymers (carboxymethylcellulose (CMC), chitosan, carrageenan and Na-alginate) during irradiation process accelerates their degradation. The highest degradation rate of polysaccharides obtained when APS was used. The end product of irradiated CMC, chitosan, carrageenan and Na-alginate may be used as food additive or benefited in agricultural purposes. On the other hand, radiation crosslinking of PAAm or PNIPAAm is affected by the presence of natural polymer like CMC-Na and carrageenan due to their degradability which could be controlled according to its concentration in the bulk medium and irradiation dose. Accordingly, the gel content, thermo-sensitivity (LCST) and swelling properties of PNIPAAm based natural polymers could be controlled. The swelling of the prepared copolymer hydrogels was investigated for its possible use in personal care articles particularly diapers or as carriers for drug delivery systems. The prepared crosslinked copolymers possessed high and fast swelling properties in simulated urine media and the swelling ratios of CMC-Na/PAAm gels in urine are acceptable for diaper

Radiation Processing of Natural Polymers for Industrial Applications

International Nuclear Information System (INIS)

Hegazy, E.A.

2008-01-01

Radiation induced degradation technology is a new and promising application of ionizing radiation to develop viscose, pulp, paper, food preservation, pharmaceutical production, and natural bioactive agents industries. Controlling the degree of degradation, uniform molecular weight distribution, saving achieved in the chemicals (used in conventional methods) on a cost basis, and environmentally friendly process are the beneficial effects of using radiation technology in these industries. However, for some development countries such technology is not economic. Therefore, a great effort should be done to reduce the cost required for such technologies. One of the principle factors for reducing the cost is achieving the degradation at low irradiation doses. The addition of some additives such as potassium per-sulfate (KPS), ammonium per-sulfate (APS), or H 2 O 2 to natural polymers (carboxy-methylcellulose (CMC), chitosan, carrageenan and Na-alginate) during irradiation process accelerates their degradation. The highest degradation rate of polysaccharides obtained when APS was used. The end product of irradiated CMC, chitosan, carrageenan and Na-alginate may be used as food additive or benefited in agricultural purposes. On the other hand, radiation crosslinking of PAAm or PNIPAAm is affected by the presence of natural polymer like CMC-Na and carrageenan due to their degradability which could be controlled according to its concentration in the bulk medium and irradiation dose. Accordingly, the gel content, thermo-sensitivity (LCST) and swelling properties of PNIPAAm based natural polymers could be controlled. The swelling of the prepared copolymer hydrogels was investigated for its possible use in personal care articles particularly diapers or as carriers for drug delivery systems. The prepared crosslinked copolymers possessed high and fast swelling properties in simulated urine media and the swelling ratios of CMC-Na /PAAm gels in urine are acceptable for diaper

IAEA specialists' meeting on Environmental factors causing cracks and degradation in primary system components: conclusions and recommendations

International Nuclear Information System (INIS)

Stahlkopf, K.E.

1981-01-01

The phenomenon of intergranular stress corrosion cracking in BWR stainless steel piping joints is well understood, and does not present a safety hazard as leak before break can be shown. It is recommended that work should proceed to reduce the probability of stress corrosion cracking by changing the BWR environment by hydrogen feedwater additions to remove oxygen. The cause of LWR pipe cracking is understood to be thermal fatigue caused by thermal stratifications at low flow rates during operation (PWR) and thermal mixing in piping tees (PWR). Recommendations include, research on corrosion fatigue crack propagation, evaluation of compressive stress state, design changes, and additional development of NDT methods for detection and sizing of cracks. Conclusions drawn steam generator tube degradation suggest that this is a potentially large problem. Recommendation include the use of stress corrosion resistant materials, oxygen reduction through use of deaeration feed banks, and inclusion in future design of inspection access to evaluate conditions of steam generators. (author)

Diazotrophic Bacterial Community of Degraded Pastures

OpenAIRE

João Tiago Correia Oliveira; Everthon Fernandes Figueredo; Williane Patrícia da Silva Diniz; Lucianne Ferreira Paes de Oliveira; Pedro Avelino Maia de Andrade; Fernando Dini Andreote; Júlia Kuklinsky-Sobral; Danúbia Ramos de Lima; Fernando José Freire

2017-01-01

Pasture degradation can cause changes in diazotrophic bacterial communities. Thus, this study aimed to evaluate the culturable and total diazotrophic bacterial community, associated with regions of the rhizosphere and roots of Brachiaria decumbens Stapf. pastures in different stages of degradation. Samples of roots and rhizospheric soil were collected from slightly, partially, and highly degraded pastures. McCrady’s table was used to obtain the Most Probable Number (MPN) of bacteria per gram ...

Fabrication of micropatterned alginate-gelatin and k-carrageenan hydrogels of defined shapes using simple wax mould method as a platform for stem cell/induced Pluripotent Stem Cells (iPSC) culture.

Science.gov (United States)

Vignesh, S; Gopalakrishnan, Aswathi; M R, Poorna; Nair, Shantikumar V; Jayakumar, R; Mony, Ullas

2018-06-01

Micropatterning techniques involve soft lithography, which is laborious, expensive and restricted to a narrow spectrum of biomaterials. In this work we report, first time employment of patterned wax moulds for generation of micropatterned alginate-gelatin and κ-carrageenan (κ-CRG) hydrogel systems by a novel, simple and cost effective method. We generated and characterized uniform and reproducible micropatterned hydrogels of varying sizes and shapes such as square projections, square grooves, and circular grids and crisscrossed hillocks. The rheological analysis showed that κ-carrageenan hydrogels had higher gel strength when compared to alginate-gelatin hydrogels. Human Mesenchymal stem cells (hMSCs) and Human Induced Pluripotent Stem Cells (hiPSCs) were found to be cytocompatible with these hydrogels. This micropatterned hydrogel system may have potential application in tissue engineering and also in understanding the basic biology behind the stem cell/iPSC fate. Copyright © 2018 Elsevier B.V. All rights reserved.

The Effect of Multidentate Biopolymer Based on Polyacrylamide Grafted onto Kappa-Carrageenan on the Spectrofluorometric Properties of Water-Soluble CdS Quantum Dots

Directory of Open Access Journals (Sweden)

Ghasem Rezanejade Bardajee

2011-01-01

Full Text Available A new fluorescent composite based on CdS quantum dots immobilized on the multidentate biopolymer matrix is prepared through the graft copolymerization of the acrylamide onto kappa-Carrageenan. A variety of techniques like thermogravimetric analysis (TGA, transmission electron microscopy (TEM, and Fourier transform infrared spectroscopy (FT-IR was used to confirm the structure of the obtained samples. To investigate the spectrofluorometric properties, fluorescence spectroscopy of the obtained quantum dots was studied.

A condition-based maintenance of a dependent degradation-threshold-shock model in a system with multiple degradation processes

International Nuclear Information System (INIS)

Caballé, N.C.; Castro, I.T.; Pérez, C.J.; Lanza-Gutiérrez, J.M.

2015-01-01

This paper proposes a condition-based maintenance strategy for a system subject to two dependent causes of failure: degradation and sudden shocks. The internal degradation is reflected by the presence of multiple degradation processes in the system. Degradation processes start at random times following a Non-homogeneous Poisson process and their growths are modelled by using a gamma process. When the deterioration level of a degradation process exceeds a predetermined value, we assume that a degradation failure occurs. Furthermore, the system is subject to sudden shocks that arrive at the system following a Doubly Stochastic Poisson Process. A sudden shock provokes the total breakdown of the system. Thus, the state of the system is evaluated at inspection times and different maintenance tasks can be carried out. If the system is still working at an inspection time, a preventive maintenance task is performed if the deterioration level of a degradation process exceeds a certain threshold. A corrective maintenance task is performed if the system is down at an inspection time. A preventive (corrective) maintenance task implies the replacement of the system by a new one. Under this maintenance strategy, the expected cost rate function is obtained. A numerical example illustrates the analytical results. - Highlights: • A condition-based maintenance model is proposed. • Two dependent causes of failure are considered: deterioration and external shocks. • Deterioration is given by multiple degradation processes growing by a gamma process. • The initiation of degradation processes follows a Non-homogeneous Poisson process. • External shocks arrive at the system by using a Doubly Stochastic Poisson Process

Soil Degradation in India: Challenges and Potential Solutions

Directory of Open Access Journals (Sweden)

Ranjan Bhattacharyya

2015-03-01

Full Text Available Soil degradation in India is estimated to be occurring on 147 million hectares (Mha of land, including 94 Mha from water erosion, 16 Mha from acidification, 14 Mha from flooding, 9 Mha from wind erosion, 6 Mha from salinity, and 7 Mha from a combination of factors. This is extremely serious because India supports 18% of the world’s human population and 15% of the world’s livestock population, but has only 2.4% of the world’s land area. Despite its low proportional land area, India ranks second worldwide in farm output. Agriculture, forestry, and fisheries account for 17% of the gross domestic product and employs about 50% of the total workforce of the country. Causes of soil degradation are both natural and human-induced. Natural causes include earthquakes, tsunamis, droughts, avalanches, landslides, volcanic eruptions, floods, tornadoes, and wildfires. Human-induced soil degradation results from land clearing and deforestation, inappropriate agricultural practices, improper management of industrial effluents and wastes, over-grazing, careless management of forests, surface mining, urban sprawl, and commercial/industrial development. Inappropriate agricultural practices include excessive tillage and use of heavy machinery, excessive and unbalanced use of inorganic fertilizers, poor irrigation and water management techniques, pesticide overuse, inadequate crop residue and/or organic carbon inputs, and poor crop cycle planning. Some underlying social causes of soil degradation in India are land shortage, decline in per capita land availability, economic pressure on land, land tenancy, poverty, and population increase. In this review of land degradation in India, we summarize (1 the main causes of soil degradation in different agro-climatic regions; (2 research results documenting both soil degradation and soil health improvement in various agricultural systems; and (3 potential solutions to improve soil health in different regions using a

Assessment of causes for degrading fuel performance at Darlington NGS

International Nuclear Information System (INIS)

Judah, J.; Goodchild, S.

2013-01-01

Fuel performance at the Darlington nuclear generating station has historically been excellent. Until recently, the majority of these few fuel defects have been attributed to fretting by heat transport system debris. The minority have been linked to manufacturing issues. Recently, Darlington has experienced an increase in the number of fuel defects. Although the defect rate remains low with respect to industry standards, this defect experience is considered to be unacceptable given current industry expectations and the OPG zero defect policy. Nine fuel defects have been discharged since 2007 from the four Darlington reactors. This represents a fuel defect rate of just 0.35 defects per year per reactor. At the time of this writing three additional defects are suspected to be in core. Although a definitive defect cause has yet to be identified, these fuel performance issues appear to be due to the coincidental degradation of manufacturing and operational factors, thereby decreasing the margins to fuel failure due to fuelling power ramps. All of the confirmed defected bundles have been long bundles and all experienced a relatively high power ramp when shifted from Position 2 to Position 6. High bundle uranium masses and low internal clearances are thought to be significant contributing factors. Bundle burnups at the time of the power ramps were low and these bundles were not identified by existing power ramp defect predictive tools. Our assessment has resulted in a number of recommendations which are designed to mitigate these adverse conditions by restoring the margins to power ramp failures. These recommendations impact broadly across a number of organizations including reactor physics, fuel design, fuel manufacturing, reactor design, inspections and PIE. (author)

Fiscal 1994 survey report. Survey of factors causing degradation of phosphoric acid fuel cells; 1994 nendo rinsangata nenryo denchi no cell rekka yoin chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-03-01

This survey aims to effectively promote studies for evaluating phosphoric acid fuel cell degradation. Data of time-dependent changes in voltage are collected from 58 plants now in operation (for 17,500 hours at the maximum). Half of them exhibit a degradation rate of 0.25-1%/1000 hours while degradation is abruptly accelerated midway in the other half. Causes for voltage drop are not known clearly. Since but a little systematically collected test data are available concerning the mechanism of cell degradation, it is decided that tests be conducted using small test model cells sharing the same specifications. Primary test conditions (combination of temperature, current, and pressure with test reference levels), performance evaluating methods (conditions of data collection), and methods of investigation by dismantling (items and frequency of investigations) are determined, and guidelines are provided for element tests for complementing the said test items and for studying their relations with the degradation mechanism. Based on acceleration-related factors to be obtained by common specification test cells, corporations involved will develop their own accelerated test methods. Small cells are fabricated for testing parameters, and model cells are specified. (NEDO)

Juiciness improvement of frozen battered shrimp burger using modified tapioca starch, sodium alginate, and iota-carrageenan

Directory of Open Access Journals (Sweden)

Kongkarn Kijroongrojana

2009-11-01

Full Text Available A battered shrimp burger, as a new value-added shrimp product, was developed by increasing the juiciness of a frozen battered shrimp burger using a mixture of hydrocolloids. The formulations of hydrocolloid mixtures containing modified tapioca starch (MTS, sodium alginate (AL, and iota-carrageenan (CA were optimized. Juiciness measurements were defined and analyzed by 13 trained panelists. Texture Profile Analysis (TPA as well as moisture and fat contents of the products were analyzed. The mixture of MTS and AL had an impact on moisture content and juiciness scores, while CA influenced the hardness. The product made using the optimized formulation (0.3% MTS + 0.7% AL had a higher moisture content andjuiciness scores (p0.05. However, higher springiness and gumminess were found in the control burger (p0.05.

Molecular view of the interaction between iota-carrageenan and a phospholipid film and its role in enzyme immobilization.

Science.gov (United States)

Nobre, Thatyane M; de Sousa e Silva, Heurison; Furriel, Rosa P M; Leone, Francisco A; Miranda, Paulo B; Zaniquelli, Maria Elisabete D

2009-05-28

Proteins incorporated into phospholipid Langmuir-Blodgett (LB) films are a good model system for biomembranes and enzyme immobilization studies. The specific fluidity of biomembranes, an important requisite for enzymatic activity, is naturally controlled by varying phospholipid compositions. In a model system, instead, LB film fluidity may be varied by covering the top layer with different substances able to interact simultaneously with the phospholipid and the protein to be immobilized. In this study, we immobilized a carbohydrate rich Neurospora crassa alkaline phosphatase (NCAP) in monolayers of the sodium salt of dihexadecylphosphoric acid (DHP), a synthetic phospholipid that provides very condensed Langmuir films. The binding of NCAP to DHP Langmuir-Blodgett (LB) films was mediated by the anionic polysaccharide iota-carrageenan (iota-car). Combining results from surface isotherms and the quartz crystal microbalance technique, we concluded that the polysaccharide was essential to promote the interaction between DHP and NCAP and also to increase the fluidity of the film. An estimate of DHP:iota-car ratio within the film also revealed that the polysaccharide binds to DHP LB film in an extended conformation. Furthermore, the investigation of the polysaccharide conformation at molecular level, using sum-frequency vibrational spectroscopy (SFG), indicated a preferential conformation of the carrageenan molecules with the sulfate groups oriented toward the phospholipid monolayer, and both the hydroxyl and ether groups interacting preferentially with the protein. These results demonstrate how interfacial electric fields can reorient and induce conformational changes in macromolecules, which may significantly affect intermolecular interactions at interfaces. This detailed knowledge of the interaction mechanism between the enzyme and the LB film is relevant to design strategies for enzyme immobilization when orientation and fluidity properties of the film provided by the

Controlled drug release from cross-linked κ-carrageenan/hyaluronic acid membranes.

Science.gov (United States)

El-Aassar, M R; El Fawal, G F; Kamoun, Elbadawy A; Fouda, Moustafa M G

2015-01-01

In this work, hydrogel membrane composed of; kappa carrageenan (κC) and hyaluronic acid (HA) crosslinked with epichlorohydrine is produced. The optimum condition has been established based on their water absorption properties. Tensile strength (TS) and elongation (E%) for the formed films are evaluated. The obtained films were characterized by FTIR, scanning electron microscopy (SEM) and thermal analysis. All membranes were loaded with l-carnosine as a drug model. The swelling properties and kinetics of the release of the model drug from the crosslinked hydrogel membrane were monitored in buffer medium at 37°C. The equilibrium swelling of films showed fair dependency on the high presence of HA in the hydrogel. Moreover, the cumulative release profile increased significantly and ranged from 28% to 93%, as HA increases. SEM explored that, the porosity increased by increasing HA content; consequently, drug release into the pores and channels of the membranes is facilitated. In addition, water uptake % increased as well. A slight change in TS occurred by increasing the HA% to κC, while the highest value of strain for κC membrane was 498.38% by using 3% HA. The thermal stability of the κC/HA was higher than that of HA. Copyright © 2015 Elsevier B.V. All rights reserved.

Redox reactions in flooded uranium mines caused by natural wood degradation

International Nuclear Information System (INIS)

Abraham, A.; Baraniak, L.; Bernhard, G.

2002-01-01

Answering the question whether U(VI) and As(V) will be reduced and precipitated as U(OH) 4 and As 2 S 3 in mine water as a result of natural wood degradation. Redox equilibria were calculated, depending on the decreasing redox potential. (orig.)

SYSTEMIC APPROACH AND ROUGHNESS APPLICATION TO CAUSE EMERGING PROPERTIES IN THE RESTORATION OF DEGRADED SOILS

Directory of Open Access Journals (Sweden)

Juarês José Aumond

2014-09-01

Full Text Available http://dx.doi.org/10.5902/1980509815737Based on the general systems theory, an ecological model for the restoration of ecosystems has been developed, which soils are highly degraded, and treating the ecosystem as a complex dynamic system, hyper-sensitive to initial conditions of soil preparation. Assuming that degraded ecosystems are sensitive to initial conditions of soil preparation, the technique of roughness was evaluated (relief variations alternating between concave and convex surfaces to trigger over time emergent properties that accelerate the process of ecological restoration. The degraded ecosystems can be understood as organizationally open systems, as a dissipative structure, in which irreversibly matter and energy flow. The main task in ecological restoration in areas that had the soil degraded is to achieve the internalization of matter and energy to induce the system to organizational closure. The roughness, represented by soil micro-topography is an effective technique in the internalization of matter, retaining water, sediment, organic matter, nutrients and seeds. Variations of relief trigger environmental changes over time in a dynamic and heterogeneous way, which influence the interactions between solar radiation, moisture and nutrients, creating different opportunities for plants and animal species. There must be an oriented concentration to flow structures and processes between the degraded ecosystem (system and the environment (neighborhood. In this approach, a particular concentration on the interrelationships between the system and the environment is dedicated. For ecological restoration, whose area is with degraded soil, such as mining and ranching, a new integrative degraded systemic approach is proposed, in which the roughness of the soil might trigger spatial and temporal patterns and emergent environmental properties due to the hyper-sensitivity to initial conditions of the land preparation.

Optimization of the extraction of carrageenan from Kappaphycus alvarezii using response surface methodology Otimização da extração de carragenana de Kappaphycus alvarezii utilizando metodologia de superfície de resposta

Directory of Open Access Journals (Sweden)

Vanessa Webber

2012-12-01

Full Text Available This study aims to optimize an alternative method of extraction of carrageenan without previous alkaline treatment and ethanol precipitation using Response Surface Methodology (RSM. In order to introduce an innovation in the isolation step, atomization drying was used reducing the time for obtaining dry carrageenan powder. The effects of extraction time and temperature on yield, gel strength, and viscosity were evaluated. Furthermore, the extracted material was submitted to structural analysis, by infrared spectroscopy and nuclear magnetic resonance spectroscopy (¹H-NMR, and chemical composition analysis. Results showed that the generated regression models adequately explained the data variation. Carrageenan yield and gel viscosity were influenced only by the extraction temperature. However, gel strength was influenced by both, extraction time and extraction temperature. Optimal extraction conditions were 74 ºC and 4 hours. In these conditions, the carrageenan extract properties determined by the polynomial model were 31.17%, 158.27 g.cm-2, and 29.5 cP for yield, gel strength, and viscosity, respectively, while under the experimental conditions they were 35.8 ± 4.68%, 112.50 ± 4.96 g.cm-2, and 16.01 ± 1.03 cP, respectively. The chemical composition, nuclear magnetic resonance spectroscopy, and infrared spectroscopy analyses showed that the crude carrageenan extracted is composed mainly of κ-carrageenan.Este estudo tem como objetivo otimizar um método alternativo para extração de carragenana sem tratamento alcalino prévio e sem precipitação com etanol através da Metodologia de Superfície de Resposta (RSM. A fim de inovar a etapa de isolamento, a secagem por atomização foi adaptada, o que reduziu o tempo para a obtenção do pó seco. Os efeitos da temperatura e do tempo de extração sobre o rendimento, força do gel e de viscosidade foram avaliados. Além disso, o material extraído foi submetido a análises estruturais por

Analgesic and Anti-Inflammatory Properties of Gelsolin in Acetic Acid Induced Writhing, Tail Immersion and Carrageenan Induced Paw Edema in Mice.

Directory of Open Access Journals (Sweden)

Ashok Kumar Gupta

Full Text Available Plasma gelsolin levels significantly decline in several disease conditions, since gelsolin gets scavenged when it depolymerizes and caps filamentous actin released in the circulation following tissue injury. It is well established that our body require/implement inflammatory and analgesic responses to protect against cell damage and injury to the tissue. This study was envisaged to examine analgesic and anti-inflammatory activity of exogenous gelsolin (8 mg/mouse in mice models of pain and acute inflammation. Administration of gelsolin in acetic acid-induced writhing and tail immersion tests not only demonstrated a significant reduction in the number of acetic acid-induced writhing effects, but also exhibited an analgesic activity in tail immersion test in mice as compared to placebo treated mice. Additionally, anti-inflammatory function of gelsolin (8 mg/mouse compared with anti-inflammatory drug diclofenac sodium (10 mg/kg] was confirmed in the carrageenan injection induced paw edema where latter was measured by vernier caliper and fluorescent tomography imaging. Interestingly, results showed that plasma gelsolin was capable of reducing severity of inflammation in mice comparable to diclofenac sodium. Analysis of cytokines and histopathological examinations of tissue revealed administration of gelsolin and diclofenac sodium significantly reduced production of pro-inflammatory cytokines, TNF-α and IL-6. Additionally, carrageenan groups pretreated with diclofenac sodium or gelsolin showed a marked decrease in edema and infiltration of inflammatory cells in paw tissue. Our study provides evidence that administration of gelsolin can effectively reduce the pain and inflammation in mice model.

Biomonitoring of ecosystem degradation caused by CPO waste of Mentaya River in Central Kalimantan use of esterase isozyme electromorph method

Directory of Open Access Journals (Sweden)

PRABANG SETYONO

2008-07-01

Full Text Available The impact of CPO (Crude Palm Oil dock activity in Mentaya River of Central Borneo caused degradation of ecosystem, particularly on both mangrove and macrozoobenthos community. One of methods used for monitoring of ecosystem degradation was to determine species that were still survive under the polluted conditions. These survival species were assumed to synthesize alloenzyme that can be used as indicator. Alloenzyme was synthesized as an effort of adaptation processes toward environmental pressures caused by CPO spill on Mentaya River. Alloenzyme would be expressed as phenotypic and genotypic adaptation processes or phenotypic plasticity. Research was carried out, consisted of field research included collecting sample and environmental data (oil content, temperature, pH, electric conductivity and redox potential, and laboratory research included series analysis of water quality (DO, BOD, COD, pH, TSS, TDS and also alloenzyme content of Soneratia caseolaris L. and Macrobrachium rosenbergii de Man. The alloenzyme of root and leaves mangrove and prawn’s hepatopancreas was analyzed using Spencer starch gel electrophoresis modified method of exposed on sucrose solution. Separated components of alloenzyme were detected by special staining for Esterase isozyme. The results revealed that Soneratia caseolaris L. and Macrobrachium rosenbergii de Man were bioindicator organisms for the polluted site by oil spills from CPO loading activities. The polluted river water by oil spill from CPO activities decreased redox potential, DO, increased oil content, DHL, water temperature, pH sediment, pH water, TDS, BOD, COD, TSS. Gel electrophoretical analysis demonstrated that Mangrove Soneratia caseolaris synthesized alloenzyme consisted of complex enzymes such as EST in its root and leave cells. Those enzymes were nearly similar to those of Macrobrachium rosenbergii. The oil spill from CPO have ester bonding so its adaptation mechanism with release Esterase

Rheological behavior of pork Biceps femoris muscle influenced by injection-tumbling process and brine type

Directory of Open Access Journals (Sweden)

Livia PĂTRAŞCU

2014-12-01

Full Text Available The effect of tumbling time (1-9 h, injection rate (20, 30, 40, and 50 % and k-carrageenan addition (0, 0.25, and 0.5 % on the rheological characteristics of pork Biceps femoris muscle were assessed. The results of the creep-recovery tests were analyzed using Burger’s equation. Increasing tumbling time up to 9 h along with injection rate also increased compliance values and decreased viscosity. K-carrageenan addition showed the occurrence of a more gel-like structure of the brine-meat system, causing further increase of the compliance and strain values. Samples injected with brine were more elastic compared to those containing k-carrageenan. A longer mechanical treatment provided a softer like matrix. Mathematical modeling of creep-compliance data showed a decreasing tendency for viscosity values with k-carrageenan addition. Discrete retarded elastic compliance values increased when adding k-carrageenan to meat-brine system. Addition of k-carrageenan did not affect the equilibrium compliance values.

Detection of pump degradation

International Nuclear Information System (INIS)

Greene, R.H.; Casada, D.A.; Ayers, C.W.

1995-08-01

This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented

Detection of pump degradation

Energy Technology Data Exchange (ETDEWEB)

Greene, R.H.; Casada, D.A.; Ayers, C.W. [and others

1995-08-01

This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented.

Motor degradation prediction methods

Energy Technology Data Exchange (ETDEWEB)

Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

1996-12-01

Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor`s duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures.

Motor degradation prediction methods

International Nuclear Information System (INIS)

Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

1996-01-01

Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor's duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures

Gamma radiation effects on the viscosity of carrageenan, agarans and alginates to be used as food additives; Efeito da radiacao gama na viscosidade de carragenanas, agaranas e alginatos utilizados na industria alimenticia

Energy Technology Data Exchange (ETDEWEB)

Aliste, Antonio Joao

1999-07-01

Carrageenan, agarans and alginates are phycocolloids, which change the consistence of the foodstuff and prevent undesirable changes such as moisture migration or textural profile changes. These phycocolloids are additives used in large scale for all kind of food products. They are not absorbed for the human organism and do not introduce extra calories in the diet. The process of irradiation, is an alternative method of great potential, because do not increase the temperature and it is highly in the decontamination of food ingredients. In this work, agar alginates and carrageenan were irradiated as powder with different doses (0-10kGy) of Co-60 and the rheological functional performance of water solutions of the irradiated additives was studied. The results are analyzed taking in account the future applications of those additives in irradiated foods. The viscosity of these hydrocolloids shows a decrease when submitted to an irradiation with doses until 10 kGy. (author)

In vivo evaluation method of the effect of nattokinase on carrageenan-induced tail thrombosis in a rat model.

Science.gov (United States)

Kamiya, Seitaro; Hagimori, Masayori; Ogasawara, Masayoshi; Arakawa, Masayuki

2010-01-01

Thrombosis is characterized by congenital and acquired procatarxis. Nattokinase inhibits thrombus formation in vitro. However, in vivo evaluation of the therapeutic efficacy of nattokinase against thrombosis remains to be conducted. Subcutaneous nattokinase injections of 1 or 2 mg/ml were administered to the tails of rats. Subsequently, κ-carrageenan was intravenously administered to the tails at 12 h after nattokinase injections. The mean length of the infarcted regions in the tails of rats was significantly shorter in rats administered 2 mg/ml of nattokinase than those in control rats. Nattokinase exhibited significant prophylactic antithrombotic effects. Previously, the in vitro efficacy of nattokinase against thrombosis had been reported; now our study has revealed the in vivo efficacy of nattokinase against thrombosis. Copyright © 2010 S. Karger AG, Basel.

Suppression of cytotoxic T lymphocytes by carrageenan-activated macrophage-like cells

International Nuclear Information System (INIS)

Yung, Y.P.; Cudkowicz, G.

1978-01-01

In the presence of 100 μg/ml of carrageenans (CAR), B6D2F 1 responder spleen cells failed to generate antiparent or anti-allogeneic cytotoxic T lymphocytes in vitro, but instead generated suppressor cells. Cultured CAR-treated cells added to mixtures of B6D2F 1 anti-B6 or B6D2F 1 anti-C3H cytotoxic effectors (induced in vitro) and the appropriate 51 Cr-labeled lymphoma targets reduced or abolished cytolysis (measured as 51 Cr release) depending on the ratio of suppressor to effector cells. Cultured spleen cells not exposed to CAR failed to inhibit both types of cytotoxicity. Presuppressor cells were associated with a splenic subpopulation independent of the thymus (i.e., present in spleens of athymic nude mice), were moderately adherent to Sephadex G-10 columns, but were not phagocytic or ''sticky'' to carbonyl iron particles. Activation of such cells by CAR was not prevented by in vitro exposure to 2000 rads of γ-rays before culture, nor facilitated by antigenic stimulation. The matured suppressor cells remained radioresistant and became strongly adherent to Sephadex G-10. The suppressors lacked surface Thy-1 alloantigen detectable by antibody and rabbit complement. Suppressor cell activity was not restricted by the immunologic specificity and major histocompatibility type of effectors

Experimental Warming Aggravates Degradation-Induced Topsoil Drought in Alpine Meadows of The Qinghai-Tibetan Plateau

Science.gov (United States)

Xue, X.

2017-12-01

Climatic warming is presumed to cause topsoil drought by increasing evapotranspiration and water infiltration, and by progressively inducing land degradation in alpine meadows of the Qinghai-Tibetan Plateau. However, how soil moisture and temperature patterns of degraded alpine meadows respond to climate warming remains unclear. A six-year continuous warming experiment was carried out in both degraded and undegraded alpine meadows in the source region of the Yangtze River. The goal was to identify the effects of climatic warming and land degradation on soil moisture (θ), soil surface temperature (Tsfc), and soil temperature (Ts). In the present study, land degradation significantly reduced θ by 4.5-6.1% at a depth of 0-100 cm (P soil surface. Experimental warming aggravated topsoil drought caused by land degradation, intensified the magnitude of degradation, and caused a positive feedback in the degraded alpine meadow ecosystem. Therefore, an immediate need exists to restore degraded alpine meadow grasslands in the Qinghai-Tibetan Plateau in anticipation of a warmer future.

Synthesis of a biocopolymer carrageenan-g-poly(AAm-co-IA/ montmorilonite superabsorbent hydrogel composite

Directory of Open Access Journals (Sweden)

M. Sadeghi

2012-06-01

Full Text Available A novel superabsorbent hydrogel composite based on kappa-carrageenan (κC has been prepared via graft copolymerization of acrylamide (AAm and itaconic acid (IA monomers in the presence of montmorolonite clay powder, methylenebisacrylamide (MBA as the crosslinking agent and ammonium persulfate (APS as initiator. Evidence of grafting and montmorolonite interaction was obtained by comparison of FTIR and TGA spectra of the initial substrates and the superabsorbent composite. A new absorption band at 1722 cm-1 in the composite spectrum confirmed montmorolonite-organic polymer linkages. Moreover, the morphology of the samples was examined by scanning electron microscopy (SEM. The swelling of the superabsorbing hydrogels was also examined in solutions with pH values ranging between 1.0 and 13.0. Finally, the swelling behavior of these composite polymers was investigated in various salt solutions. Results indicated that the swelling capacity decreased with an increase in the ionic strength of the swelling medium. This behavior can be attributed to the charge screening effect of monovalent cations, as well as ionic crosslinking for multivalent cations.

Influence of structural features of carrageenan on the formation of polyelectrolyte complexes with chitosan.

Science.gov (United States)

Volod'ko, A V; Davydova, V N; Glazunov, V P; Likhatskaya, G N; Yermak, I M

2016-03-01

The polyelectrolyte complexes (PEC) of carrageenans (CG)-κ-, κ/β-, λ-and x-CG with chitosan were obtained. The formation of PEC was detected by Fourier-transform infrared (FTIR) spectroscopy and by centrifugation in a Percoll gradient. The influence of the structural peculiarities of CG on its interaction with chitosan was studied. The results of centrifugation showed that x-CG with a high degree of sulphation (SD) was completely bound to chitosan, unlike low SD κ-CG and κ/β-CG. Binding constant values showed there was a high affinity of CG for chitosan. CG with flexible macromolecule conformation and high SD exhibited the greatest binding affinity for chitosan. The full-atomic 3D-structures of the PEC κ-CG: chitosan in solution have been obtained by the experiments in silico for the first time. The amino groups of chitosan make the largest contribution to the energy of the complex formation by means of hydrogen and ionic bonds. The most probable complexes have stoichiometries of 1:1 and 1:1.5. Copyright © 2015 Elsevier B.V. All rights reserved.

Air drying modelling of Mastocarpus stellatus seaweed a source of hybrid carrageenan

Science.gov (United States)

Arufe, Santiago; Torres, Maria D.; Chenlo, Francisco; Moreira, Ramon

2018-01-01

Water sorption isotherms from 5 up to 65 °C and air drying kinetics at 35, 45 and 55 °C of Mastocarpus stellatus seaweed were determined. Experimental sorption data were modelled using BET and Oswin models. A four-parameter model, based on Oswin model, was proposed to estimate equilibrium moisture content as function of water activity and temperature simultaneously. Drying experiments showed that water removal rate increased significantly with temperature from 35 to 45 °C, but at higher temperatures drying rate remained constant. Some chemical modifications of the hybrid carrageenans present in the seaweed can be responsible of this unexpected thermal trend. Experimental drying data were modelled using two-parameter Page model (n, k). Page parameter n was constant (1.31 ± 0.10) at tested temperatures, but k varied significantly with drying temperature (from 18.5 ± 0.2 10-3 min-n at 35 °C up to 28.4 ± 0.8 10-3 min-n at 45 and 55 °C). Drying experiments allowed the determination of the critical moisture content of seaweed (0.87 ± 0.06 kg water (kg d.b.)-1). A diffusional model considering slab geometry was employed to determine the effective diffusion coefficient of water during the falling rate period at different temperatures.

Accelerated degradation and durability of concrete in cold climates.

Science.gov (United States)

2011-08-01

Degradation of aggregate in concrete can be caused by erosion or fracture, and both cementitious materials and aggregate age over time. : The specification requirements for the degradation of aggregates have been established for hot mix asphalt and f...

Review for carrageenan-based pharmaceutical biomaterials: favourable physical features versus adverse biological effects.

Science.gov (United States)

Liu, Jingjing; Zhan, Xiudan; Wan, Jianbo; Wang, Yitao; Wang, Chunming

2015-05-05

Carrageenan (CRG) is a family of natural polysaccharides derived from seaweeds and has widely been used as food additives. In the past decade, owing to its attractive physicochemical properties, CRG has been developed into versatile biomaterials vehicles for drug delivery. Nevertheless, studies also emerged to reveal its adverse effects on the biological system. In this review, we critically appraise the latest literature (two thirds since 2008) on the development of CRG-based pharmaceutical vehicles and the perspective of using CRG for broader biomedical applications. We focus on how current strategies exploit the unique gelling mechanisms, strong water absorption and abundant functional groups of the three major CRG varieties. Notably, CRG-based matrices are demonstrated to increase drug loading and drug solubility, enabling release of orally administrated drugs in zero-order or in a significantly prolonged period. Other amazing features, such as pH-sensitivity and adhesive property, of CRG-based formulations are also introduced. Finally, we discuss the adverse influence of CRG on the human body and then suggest some future directions for the development of CRG-based biomaterials for broader applications in biomedicine. Copyright © 2015 Elsevier Ltd. All rights reserved.

k-Carrageenan/poly vinyl pyrollidone/polyethylene glycol/silver nanoparticles film for biomedical application.

Science.gov (United States)

Fouda, Moustafa M G; El-Aassar, M R; El Fawal, G F; Hafez, Elsayed E; Masry, Saad Hamdy Daif; Abdel-Megeed, Ahmed

2015-03-01

Biopolymer composite film containing k-carrageenan (KC), polyvinyl pyrrolidone (PVP), and polyethylene glycol (PEG) was formulated by dissolving KC and PVP in water containing PEG. Silver nanoparticles (AgNPs), was produced by Honeybee and added to solution. Finally, all solutions were poured onto dishes and dried overnight at 40°C to form the final films. Tensile strength (TS) and elongation (E %) is evaluated. The water contact angle is inspected. Thermal properties (TGA) and swelling behavior for water were considered. Fungal activity is also examined. Morphology of all films was also explored using scanning electron microscope. AgNPs induced significant hydrophilicity to KC-PVP-PEG film with contact angle of 41.6 and 34.7 for KC-PVP-PEG-AgNPs. Films with AgNPs exhibited higher thermal stability and strength properties than other films without. Films with AgNPs explore lower swelling behavior than other films without. Both SEM and EDX proved the deposition of AgNPs on the surface of films. Films with AgNPs showed higher activity against pathogenic fungi compared with the chemical fungicide; fluconazole. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation and Selection of Indicators for Land Degradation and Desertification Monitoring: Types of Degradation, Causes, and Implications for Management

NARCIS (Netherlands)

Kairis, O.; Kosmas, C.; Karavitis, C.; Ritsema, C.J.; Salvati, L.; Acikalin, S.; Alcala, M.; Alfama, P.; Atlhopheng, J.; Barrera, J.; Belgacem, A.; Sole-Benet, A.; Brito, J.; Chaker, M.; Chanda, R.; Coelho, C.; Darkoh, M.; Diamantis, I.; Ermolaeva, O.; Fassouli, V.; Fei, W.; Feng, J.; Fernandez, F.; Ferreira, A.; Gokceoglu, C.; Gonzalez, D.; Gungor, H.; Hessel, R.; Juying, J.; Khatteli, H.; Khitrov, N.; Kounalaki, A.; Laouina, A.; Lollino, P.; Lopes, M.; Magole, L.; Medina, L.; Mendoza, M.; Morais, P.; Mulale, K.; Ocakoglu, F.; Ouessar, M.; Ovalle, C.; Perez, C.; Perkins, J.; Pliakas, F.; Polemio, M.; Pozo, A.; Prat, C.; Qinke, Y.; Ramos, A.; Ramos, J.; Riquelme, J.; Romanenkov, V.; Rui, L.; Santaloia, F.; Sebego, R.; Sghaier, M.; Silva, N.; Sizemskaya, M.; Soares, J.; Sonmez, H.; Taamallah, H.; Tezcan, L.; Torri, D.; Ungaro, F.; Valente, S.; Vente, de J.; Zagal, E.; Zeiliguer, A.; Zhonging, W.; Ziogas, A.

2014-01-01

Indicator-based approaches are often used to monitor land degradation and desertification from the global to the very local scale. However, there is still little agreement on which indicators may best reflect both status and trends of these phenomena. In this study, various processes of land

Investigation of possible causes for human-performance degradation during microgravity flight

Science.gov (United States)

Schroeder, James E.; Tuttle, Megan L.

1992-01-01

The results of the first year of a three year study of the effects of microgravity on human performance are given. Test results show support for the hypothesis that the effects of microgravity can be studied indirectly on Earth by measuring performance in an altered gravitational field. The hypothesis was that an altered gravitational field could disrupt performance on previously automated behaviors if gravity was a critical part of the stimulus complex controlling those behaviors. In addition, it was proposed that performance on secondary cognitive tasks would also degrade, especially if the subject was provided feedback about degradation on the previously automated task. In the initial experimental test of these hypotheses, there was little statistical support. However, when subjects were categorized as high or low in automated behavior, results for the former group supported the hypotheses. The predicted interaction between body orientation and level of workload in their joint effect on performance in the secondary cognitive task was significant for the group high in automatized behavior and receiving feedback, but no such interventions were found for the group high in automatized behavior but not receiving feedback, or the group low in automatized behavior.

Human Adenovirus Infection Causes Cellular E3 Ubiquitin Ligase MKRN1 Degradation Involving the Viral Core Protein pVII.

Science.gov (United States)

Inturi, Raviteja; Mun, Kwangchol; Singethan, Katrin; Schreiner, Sabrina; Punga, Tanel

2018-02-01

Human adenoviruses (HAdVs) are common human pathogens encoding a highly abundant histone-like core protein, VII, which is involved in nuclear delivery and protection of viral DNA as well as in sequestering immune danger signals in infected cells. The molecular details of how protein VII acts as a multifunctional protein have remained to a large extent enigmatic. Here we report the identification of several cellular proteins interacting with the precursor pVII protein. We show that the cellular E3 ubiquitin ligase MKRN1 is a novel precursor pVII-interacting protein in HAdV-C5-infected cells. Surprisingly, the endogenous MKRN1 protein underwent proteasomal degradation during the late phase of HAdV-C5 infection in various human cell lines. MKRN1 protein degradation occurred independently of the HAdV E1B55K and E4orf6 proteins. We provide experimental evidence that the precursor pVII protein binding enhances MKRN1 self-ubiquitination, whereas the processed mature VII protein is deficient in this function. Based on these data, we propose that the pVII protein binding promotes MKRN1 self-ubiquitination, followed by proteasomal degradation of the MKRN1 protein, in HAdV-C5-infected cells. In addition, we show that measles virus and vesicular stomatitis virus infections reduce the MKRN1 protein accumulation in the recipient cells. Taken together, our results expand the functional repertoire of the HAdV-C5 precursor pVII protein in lytic virus infection and highlight MKRN1 as a potential common target during different virus infections. IMPORTANCE Human adenoviruses (HAdVs) are common pathogens causing a wide range of diseases. To achieve pathogenicity, HAdVs have to counteract a variety of host cell antiviral defense systems, which would otherwise hamper virus replication. In this study, we show that the HAdV-C5 histone-like core protein pVII binds to and promotes self-ubiquitination of a cellular E3 ubiquitin ligase named MKRN1. This mutual interaction between the pVII and

Radiation degradation of alginate and chitosan

Energy Technology Data Exchange (ETDEWEB)

Nagasawa, Naotsugu; Mitomo, Hiroshi [Department of Biological and Chemical Engineering, Faculty of Engineering, Gunma University, Kiryu, Gunma (Japan); Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2000-03-01

Alginate and chitosan were irradiated in solid or aqueous solution condition with Co{sup 60} gamma rays in the dose range of 20 to 500 kGy. Degradation was observed both in solid and solution conditions. The degradation in solution was remarkably greater than that in solid. For example, the molecular weight of alginate in 4%(w/v) solution decreased from 2 x 10{sup 5} for 0 kGy to 6 x 10{sup 3} for 50 kGy irradiation while the equivalent degradation by solid irradiation required 500 kGy. The activated species from irradiated water must be responsible for the degradation in solution. The degradation was also accompanied with the color change of alginate: the color became deep brown for highly degraded alginate. UV spectra showed a distinct absorption peak at 265 nm for colored alginates, increasing with dose. The fact that discoloration of colored alginate was caused on exposure to ozone suggests a formation of double bond in pyranose-ring by scission of glycosidic bond. Degradation behavior of chitosan in irradiation was almost the same as that of alginate. (author)

Structural Modification of Fish Gelatin by the Addition of Gellan, κ-Carrageenan, and Salts Mimics the Critical Physicochemical Properties of Pork Gelatin.

Science.gov (United States)

Sow, Li Cheng; Kong, Karmaine; Yang, Hongshun

2018-05-01

Pork gelatin is not suitable for halal and kosher application; however, fish gelatin (FG) can be modified for use as a pork gelatin (PG) mimetic. Herein, low-acyl gellan (GE), κ-carrageenan (KC), and salts (CaCl 2 or KCl) were combined with a 180 Bloom tilapia FG. A formulation comprising 5.925% (w/v) FG + 0.025% (w/v) GE + 3mM CaCl 2 best matched the physicochemical properties of PG. The modification increased the FG gel strength from 115 ± 2 to 149 ± 2 g (matching the 148 ± 2 of PG), while the T m increased from 27.9 ± 1.0 to 32.4 ± 0.8 °C (matching the 33.1 ± 0.3 °C of PG). Nanoaggregates (diameter between 150 and 300 nm) could be an important structural factor affecting the physicochemical properties, as both PG and GE-modified FG showed a similar frequency distribution in this size group (57.4 ± 1.6% (PG) compared with 56.3 ± 2.2% (modified FG)). To further explore the differences between KC and GE in modifying of FG's structure, the FG-KC and FG-GE gels were compared. The zeta potential and Fourier transform infrared (FTIR) spectroscopy results for the FG-KC gel supported an associative interaction with complex formation, as indicated from the large aggregates and amorphous phase under atomic force microscopy (AFM). Contrastingly, a segregative FG-GE interaction took place in presence of CaCl 2 . These structures and interaction differences between FG-GE and FG-KC influenced the macro-properties of FG, possibly explaining the differences in the modification of the melting temperature of FG. A diagram representing the interaction-structure-physicochemical properties was proposed to explain the differences between the FG-GE and FG-KC gels. Certain people cannot consume any pork product or derivatives for religious reasons, thus it is essential to find a pork gelatin (PG) substitute for food product development. The commonly used polysaccharides, gellan and carrageenan, together with salt, can be added to fish gelatin (FG) to match the

Synthesis and anti-inflammatory activity of 3-indolyl pyridine ...

Indian Academy of Sciences (India)

Administrator

obtained from sea weed (rhodophyceae) and when injected causes the release of histamine 5-HT, bra- dykininins and prostaglandins. It produce inflamma- tion and oedema. 3.1a Preparation of 1% carrageenan solution: Carrageenan (1 g) was dissolved in 0.9% saline and the maximum volume administered to the rat was.

An Operational Framework for Defining and Monitoring Forest Degradation

Directory of Open Access Journals (Sweden)

Ian D. Thompson

2013-06-01

Full Text Available Forest degradation is broadly defined as a reduction in the capacity of a forest to produce ecosystem services such as carbon storage and wood products as a result of anthropogenic and environmental changes. The main causes of degradation include unsustainable logging, agriculture, invasive species, fire, fuelwood gathering, and livestock grazing. Forest degradation is widespread and has become an important consideration in global policy processes that deal with biodiversity, climate change, and forest management. There is, however, no generally recognized way to identify a degraded forest because perceptions of forest degradation vary depending on the cause, the particular goods or services of interest, and the temporal and spatial scales considered. Here, we suggest that there are types of forest degradation that produce a continuum of decline in provision of ecosystem services, from those in primary forests through various forms of managed forests to deforestation. Forest degradation must be measured against a desired baseline condition, and the types of degradation can be represented using five criteria that relate to the drivers of degradation, loss of ecosystem services and sustainable management, including: productivity, biodiversity, unusual disturbances, protective functions, and carbon storage. These criteria are not meant to be equivalent and some might be considered more important than others, depending on the local forest management objectives. We propose a minimum subset of seven indicators for the five criteria that should be assessed to determine forest degradation under a sustainable ecosystem management regime. The indicators can be remotely sensed (although improving calibration requires ground work and aggregated from stand to management unit or landscape levels and ultimately to sub-national and national scales.

Degradation of shape memory effect

International Nuclear Information System (INIS)

Vandermeer, R.A.

1983-01-01

An important parameter for deciding whether or not a SME alloy is suitable for practical applications is the magnitude of the strain reversal accompanying martensite reversion. This research is concerned with elucidating metallurgical factors that cause degradation of this heat-activated recovery strain, E/sub R/. After explaining what is meant by degradation, two manifestations of degradation recently identified in near-monotectoid uranium-niobium alloys are described. The first was associated with the onset of plastic deformation of the martensite beyond the reversible strain limit, E/sub L/; a reduction of E/sub R/ from 5.25% at 8% total strain, i.e. E/sub L/, to 2.9% at 12% total strain was observed. A second type of degradation depended strongly on the heating rate during reversion; the E/sub R/ for an imposed strain of 6.95% was reduced from a value of 5.25% to 1.3% when the heating rate was decreased from 40 0 /sec to 0.05 0 /sec. Degradation was attributed to a change in the transformation path and the interjection of time-dependent, low temperature aging reactions

Synthesis of PVA-Chitosan Hydrogels for Wound Dressing Using Gamma Irradiation. Part I: Radiation Degradation of Chitosan in Solid State and in Solution

International Nuclear Information System (INIS)

Mahlous, M.; Tahtat, D.; Benamer, S.; Nacer Khodja, A.; Larbi Youcef, S.

2010-01-01

Chitosan is a partially deacetylated product of chitin, a very abundant polysaccharide, existing in exoskeleton of crustaceans. It is a polymer consisting of glucosamine and N-acetylglucosamine units linked by β-1-4-glycosidic bonds. Chitosan, like others polysaccharides, such as cellulose derivatives, alginates and carrageenan is widely used in food, medicine and cosmetic fields. Chitosan presents a variety of distinctive properties, such as biocompatibility, biodegradability, nontoxicity and nonantigenicity. Chitosan obtained by the deacetylation of chitin has, generally, a high molecular weight, which limits its solubility in aqueous solvents. The reduction of its molecular weight by degradation is usually used in order to improve its water solubility. Water-soluble chitosan exhibit some specific properties, such as antifungal activity, antimicrobial activity and plant growth promotion. Among the methods that have been tried to produce low molecular weight chitosan, radiation processing is the most promising one, since the process is simple, it is carried out at room temperature and no purification of the product is required after processing

Shifting agriculture: the main cause of landscape degradation in the Central Spanish Pyrenees

Science.gov (United States)

Lasanta, Teodoro; Nadal-Romero, Estela; Errea, Paz

2017-04-01

Cereal agriculture occupied large areas in the Spanish Pyrenees to feed the population in a socio-economic system of limited exchanges with the outside. In the Western valleys, shifting agriculture constitutes the dominant field pattern, representing almost three-quarters of the traditional agricultural space (Lasanta et al., in press). These were cultivated at times of heavy population growth, necessitating steep and stony hillsides with poor soil to be tilled, or the ones that were far away from the village. The fields were created by clearing the vegetation from a slope, then burning it to use the ash as a fertilizer. Cereal was grown for 3-4 years, after which they were abandoned for 20-30 years to recover fertility, and the cycle was repeated. Almost all the fields (99%) using shifting agriculture had been abandoned by the 1950s. This study analyzes the role of the shifting agriculture in soil erosion and landscape degradation. For this purpose, (i) experimental plots, which reproduce the traditional agriculture in the Pyrenees and the abandonment processes, and (ii) the cartography made from the SIOSE (2009), which shows the present land cover 50 years after cropland abandonment, were used. The results show that shifting agriculture caused higher soil losses than other agricultural uses (1.36 kg m-2 yr-1): fallow land (0.87 kg m-2 yr-1), chemically fertilized cereal (0.86 kg m-2 yr-1) and meadow (0.14 kg m-2 yr-1). Also, after land abandonment, soil losses are higher in shifting agriculture (0.78 kg m-2 yr-1) than cereal lands (0.73 kg m-2 yr-1). The burning of the shrub cover and the use of ashes as fertilizer did not contribute to improve the soil quality, which explains both the higher soil losses during the cultivated period and after the abandonment, since slower plant succession occurs. The results obtained from the SIOSE confirm that the change from meadows to shrubland is relatively fast, as a consequence of the low relationship with livestock

κ-Carrageenan Enhances the Biomineralization and Osteogenic Differentiation of Electrospun Polyhydroxybutyrate and Polyhydroxybutyrate Valerate Fibers.

Science.gov (United States)

Goonoo, Nowsheen; Khanbabaee, Behnam; Steuber, Marc; Bhaw-Luximon, Archana; Jonas, Ulrich; Pietsch, Ullrich; Jhurry, Dhanjay; Schönherr, Holger

2017-05-08

Novel electrospun materials for bone tissue engineering were obtained by blending biodegradable polyhydroxybutyrate (PHB) or polyhydroxybutyrate valerate (PHBV) with the anionic sulfated polysaccharide κ-carrageenan (κ-CG) in varying ratios. In both systems, the two components phase separated as shown by FTIR, DSC and TGA. According to the contact angle data, κ-CG was localized preferentially at the fiber surface in PHBV/κ-CG blends in contrast to PHB/κ-CG, where the biopolymer was mostly found within the fiber. In contrast to the neat polyester fibers, the blends led to the formation of much smaller apatite crystals (800 nm vs 7 μm). According to the MTT assay, NIH3T3 cells grew in higher density on the blend mats in comparison to neat polyester mats. The osteogenic differentiation potential of the fibers was determined by SaOS-2 cell culture for 2 weeks. Alizarin red-S staining suggested an improved mineralization on the blend fibers. Thus, PHBV/κ-CG fibers resulted in more pronounced bioactive and osteogenic properties, including fast apatite-forming ability and deposition of nanosized apatite crystals.

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.

EFFECT OF COMMERCIALLY MANUFACTURED KAPPA SEMI-REFINED CARRAGEENAN (SRC WITH DIFFERENT PHOSPHATE SALTS ON YIELD, TEXTURAL AND SENSORY PROPERTIES OF BEEF MEAT

Directory of Open Access Journals (Sweden)

Marimuthu Murugesan

2016-06-01

Full Text Available The phosphate salts such as SDP, TSP, SHMP, DSP, TPPP, TKPP and STPP were blended with semi-refined kappa carrageenan (SRC individually and their aqueous solution was injected into the fresh beef meat. The highest weight gain (24% in fresh meat was obtained from injection of blend made with SRC and STPP as compared to other blends and control sample after forzen storage. Similarly, it also showed low cooking loss (24% with good testural and sensory proerties as compared to other blends. It can be concluded from the presnt study that blend of SRC and STPP can be used in beef meat for yield and quality improvement.

Operating experience feedback report: Service water system failures and degradations: Volume 3

International Nuclear Information System (INIS)

Lam, P.; Leeds, E.

1988-11-01

A comprehensive review and evaluation of service water system failures and degradations observed in operating events in light water reactors from 1980 to 1987 has been conducted. The review and evaluation focused on the identification of causes of system failures and degradations, the adequacy of corrective actions implemented and planned, and the safety significance of the operating events. The results of this review and evaluation indicate that the service water system failures and degradations have significant safety implications. These system failures and degradations are attributable to a great variety of causes, and have adverse impact on a large number of safety-related systems and components which are required to mitigate reactor accidents. Specifically, the causes of failures and degradations include various fouling mechanisms (sediment deposition, biofouling, corrosion and erosion, pipe coating failure, calcium carbonate, foreign material and debris intrusion); single failures and other design deficiencies; flooding; multiple equipment failures; personnel and procedural errors; and seismic deficiencies. Systems and components adversely impacted by a service water system failure or degradation include the component cooling water system, emergency diesel generators, emergency core cooling system pumps and heat exchangers, the residual heat removal system, containment spray and fan coolers, control room chillers, and reactor building cooling units. 44 refs., 10 figs., 5 tabs

Overview of restoration and management practices in the degraded ...

African Journals Online (AJOL)

The highest deforestation and forest degradation rates in Africa occur in the dry forests and woodlands where pressure for land is increasing, poverty is rampant, livelihood options are few and climate change effects are severe. This paper examines factors that cause land and forest degradation in the Sahel and dry forests ...

In vitro and in vivo ocular safety and eye surface permanence determination by direct and Magnetic Resonance Imaging of ion-sensitive hydrogels based on gellan gum and kappa-carrageenan.

Science.gov (United States)

Fernández-Ferreiro, Anxo; González Barcia, Miguel; Gil-Martínez, María; Vieites-Prado, Alba; Lema, Isabel; Argibay, Barbara; Blanco Méndez, José; Lamas, Maria Jesus; Otero-Espinar, Francisco Javier

2015-08-01

Gellan gum, kappa-carrageenan and alginates are natural polysaccharides able to interact with different cations that can be used to elaborate ion-activated in situ gelling systems for different uses. The interaction between fluid solutions of these polysaccharides and cations presents into the tear made these biopolymers very interesting to elaborate ophthalmic drug delivery systems. The main purpose of this study is to evaluate the ability of mixtures of these polymers to obtain ion-activated ophthalmic in situ gelling systems with optimal properties for ocular use. To achieve this purpose different proportion of the biopolymers were analyzed using a mixture experimental design evaluating their transparency, mechanical properties and bioadhesion in the absence and presence of simulated tear fluid. Tear induces a rapid sol-to-gel phase transition in the mixtures forming a consistent hydrogel. The solution composed by 80% of gellan gum and 20% kappa-carrageenan showed the best mechanical and mucoadhesive properties. This mixture was evaluated for rheological behavior, microstructure, cytotoxicity, acute corneal irritancy, ex-vivo and in vivo ocular toxicity and in vivo corneal contact time using Magnetic Resonance Images (MRI) techniques. Result indicates that the system is safe at ophthalmic level and produces an extensive ocular permanence higher than 6h. Copyright © 2015 Elsevier B.V. All rights reserved.

Use of antioxidants substances to protect the hydrocolloids carrageenan, agaran and alginates used in food industry when exposed to radiation; Uso de substancias antioxidantes na resposta a radiacao dos hidrocoloides carragenanas, agaranas e alginatos utilizados na industria alimenticia

Energy Technology Data Exchange (ETDEWEB)

Aliste, Antonio Joao

2006-07-01

Carrageenan, agaran e alginates are hydrocolloids largely employed in every kind of food products as stabilizing agent and viscosity builder. The human body does not absorb them, so they do not introduce extra calories in the diet. Irradiation is presented as an important alternative method in food preservation because do not induce temperature increase being of good efficiency in cold food ingredients decontamination. In this work aqueous solutions of carrageenan, agar e sodium alginate were gamma irradiated (0-10 kGy) in presence of ascorbic acid, roselle (Hibiscus sabdariffa L.) extract and soy isoflavone. Edible polysaccharide solutions showed to be suitable systems for the evaluation of ionizing radiation effects as they presented a singular radiosensitivity through viscosity changes. The results obtained showed that in general the antioxidants employed had a radioprotective action that can be of importance in the future commercial applications of food irradiation. (author)

Structural insight into molecular mechanism of poly(ethylene terephthalate) degradation

OpenAIRE

Joo, Seongjoon; Cho, In Jin; Seo, Hogyun; Son, Hyeoncheol Francis; Sagong, Hye-Young; Shin, Tae Joo; Choi, So Young; Lee, Sang Yup; Kim, Kyung-Jin

2018-01-01

Plastics, including poly(ethylene terephthalate) (PET), possess many desirable characteristics and thus are widely used in daily life. However, non-biodegradability, once thought to be an advantage offered by plastics, is causing major environmental problem. Recently, a PET-degrading bacterium, Ideonella sakaiensis, was identified and suggested for possible use in degradation and/or recycling of PET. However, the molecular mechanism of PET degradation is not known. Here we report the crystal ...

Degradation and toxicity of phenyltin compounds in soil

International Nuclear Information System (INIS)

Paton, G.I.; Cheewasedtham, W.; Marr, I.L.; Dawson, J.J.C.

2006-01-01

Although the fate of organotins has been widely studied in the marine environment, fewer studies have considered their impact in terrestrial systems. The degradation and toxicity of triphenyltin in autoclaved, autoclaved-reinoculated and non-sterilised soil was studied in a 231 day incubation experiment following a single application. Degradation and toxicity of phenyltin compounds in soil was monitored using both chemical and microbial (lux-based bacterial biosensors) methods. Degradation was significantly slower in the sterile soil when compared to non-sterilised soils. In the non-sterilised treatment, the half-life of triphenyltin was 27 and 33 days at amendments of 10 and 20 mg Sn kg -1 , respectively. As initial triphenyltin degradation occurred, there was a commensurate increase in toxicity, reflecting the fact that metabolites produced may be both more bioavailable and toxic to the target receptor. Over time, the toxicity reduced as degradation proceeded. The toxicity impact on non-target receptors for these compounds may be significant. - Triphenyltin degradative metabolites cause toxic responses to biosensors

Diazotrophic Bacterial Community of Degraded Pastures

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João Tiago Correia Oliveira

2017-01-01

Full Text Available Pasture degradation can cause changes in diazotrophic bacterial communities. Thus, this study aimed to evaluate the culturable and total diazotrophic bacterial community, associated with regions of the rhizosphere and roots of Brachiaria decumbens Stapf. pastures in different stages of degradation. Samples of roots and rhizospheric soil were collected from slightly, partially, and highly degraded pastures. McCrady’s table was used to obtain the Most Probable Number (MPN of bacteria per gram of sample, in order to determine population density and calculate the Shannon-Weaver diversity index. The diversity of total diazotrophic bacterial community was determined by the technique of Denaturing Gradient Gel Electrophoresis (DGGE of the nifH gene, while the diversity of the culturable diazotrophic bacteria was determined by the Polymerase Chain Reaction (BOX-PCR technique. The increase in the degradation stage of the B. decumbens Stapf. pasture did not reduce the population density of the cultivated diazotrophic bacterial community, suggesting that the degradation at any degree of severity was highly harmful to the bacteria. The structure of the total diazotrophic bacterial community associated with B. decumbens Stapf. was altered by the pasture degradation stage, suggesting a high adaptive capacity of the bacteria to altered environments.

Elastomer degradation sensor using a piezoelectric material

Science.gov (United States)

Olness, Dolores U.; Hirschfeld, deceased, Tomas B.

1990-01-01

A method and apparatus for monitoring the degradation of elastomeric materials is provided. Piezoelectric oscillators are placed in contact with the elastomeric material so that a forced harmonic oscillator with damping is formed. The piezoelectric material is connected to an oscillator circuit,. A parameter such as the resonant frequency, amplitude or Q value of the oscillating system is related to the elasticity of the elastomeric material. Degradation of the elastomeric material causes changes in its elasticity which, in turn, causes the resonant frequency, amplitude or Q of the oscillator to change. These changes are monitored with a peak height monitor, frequency counter, Q-meter, spectrum analyzer, or other measurement circuit. Elasticity of elastomers can be monitored in situ, using miniaturized sensors.

Oxidative degradation of lignin by photochemical and chemical radical generating systems

International Nuclear Information System (INIS)

Gold, M.H.; Kutsuki, H.; Morgan, M.A.

1983-01-01

Oxidation of specifically radiolabeled 14 C-lignins by UV/H 2 O 2 , Fenton's reagent, photosensitizing riboflavin, UV- and γ-irradiation was examined. In the presence of UV/H 2 O 2 , a hydroxyl radical (radicalOH) generating system, 14 C-methoxy, 2-[ 14 C-sidechain] and 14 C-ring labeled lignin were rapidly and extensively degraded as measured by gel filtration of the reaction products on Sephadex LH-20. This suggested that exposure to radicalOH leads to rapid, nonspecific lignin degradation. Rapid degradation of 14 C-methoxy, 2-[ 14 C-sidechain] and 14 C-ring labeled lignin also occurred in the presence of the radicalOH generating system, Fenton's reagent, confirming the primary role of radicalOH in these reactions. Photosensitizing riboflavin, also capable of effecting transformation of organic compounds via Type I hydrogen radical abstractions, caused extensive oxidative degradation of 14 C-methoxy labeled lignin and significant degradation of 2-[ 14 C-sidechain] and 14 C-ring labeled lignin. In addition, UV- and γ-irradiation caused slower but extensive degradation of the polymers, probably via radical type mechanisms. All of these results indicate that radicalOH as well as organic radical generating systems are effective agents for the purpose of degrading this heterogeneous, optically inactive and random biopolymer. (author)

Radiation degradation of silk protein

International Nuclear Information System (INIS)

Pewlong, W.; Sudatis, B.; Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu

2000-01-01

Silk fibroin fiber from the domesticated silkworm Bombyx mori was irradiated using an electron beam accelerator to investigate the application of the radiation degradation technique as a means to solubilize fibroin. The irradiation caused a significant degradation of the fiber. The tensile strength of fibroin fiber irradiated up to 2500 kGy decreased rapidly with increasing dose. The presence of oxygen in the irradiation atmosphere enhanced degradation of the tensile strength. The solubilization of irradiated fibroin fiber was evaluated using the following three kinds of solutions: a calcium chloride solution(CaCl 2 /C 2 H 5 OH/H 2 O=1:2:8 in mole ratio), a hydrochloric acid (0.5 N) and a distilled water. Dissolution of fibroin fiber into these solutions was significantly enhanced by irradiation. Especially, an appreciable amount of water soluble proteins was extracted by a distilled water. (author)

Radiation degradation of silk protein

Energy Technology Data Exchange (ETDEWEB)

Pewlong, W; Sudatis, B [Office of Atomic Energy for Peace, Bangkok (Thailand); Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2000-03-01

Silk fibroin fiber from the domesticated silkworm Bombyx mori was irradiated using an electron beam accelerator to investigate the application of the radiation degradation technique as a means to solubilize fibroin. The irradiation caused a significant degradation of the fiber. The tensile strength of fibroin fiber irradiated up to 2500 kGy decreased rapidly with increasing dose. The presence of oxygen in the irradiation atmosphere enhanced degradation of the tensile strength. The solubilization of irradiated fibroin fiber was evaluated using the following three kinds of solutions: a calcium chloride solution(CaCl{sub 2}/C{sub 2}H{sub 5}OH/H{sub 2}O=1:2:8 in mole ratio), a hydrochloric acid (0.5 N) and a distilled water. Dissolution of fibroin fiber into these solutions was significantly enhanced by irradiation. Especially, an appreciable amount of water soluble proteins was extracted by a distilled water. (author)

Evaluation of the performance degradation at PAFC effect of catalyst degradation on electrode performance

Energy Technology Data Exchange (ETDEWEB)

Nishizaki, K.; Uchida, H.; Watanabe, M. [Yamanashi Univ., Kofu (Japan)] [and others

1996-12-31

Aiming commercialization of Phosphoric Acid Fuel Cell (PAFC) power plant, many researches and developments have been contributed. Over 20000 hours operations have been demonstrated by many PAFC power plants. But there is no effective method for the estimation of lifetime of electrochemical cells without a practical long-term operation. Conducted by New Energy and Industrial Technology Development Organization (NEDO), cooperative research projects aiming development of PAFC lifetime estimation method have started since 1995 FY in Japan. As part of this project, this work has been performed to clarify basic phenomena of the performance degradation at PAFCs jointly by Yamanashi University, Phosphoric Acid Fuel Cell Technology Research Association (PAFC-TRA) and PAFC manufacturers (Toshiba Co., Mitsubishi Electric Co, Fuji Electric Co.). Among several main causes of the cell performance degradation, effects of catalyst degradation (reduction in metal surface area, dealloying, changes in catalyst support) on PAFC cathode performances are discussed in this work.

Anti-inflammatory and anti-allergic properties of the essential oil and active compounds from Cordia verbenacea.

Science.gov (United States)

Passos, Giselle F; Fernandes, Elizabeth S; da Cunha, Fernanda M; Ferreira, Juliano; Pianowski, Luiz F; Campos, Maria M; Calixto, João B

2007-03-21

The anti-inflammatory and anti-allergic effects of the essential oil of Cordia verbenacea (Boraginaceae) and some of its active compounds were evaluated. Systemic treatment with the essential oil of Cordia verbenacea (300-600mg/kg, p.o.) reduced carrageenan-induced rat paw oedema, myeloperoxidase activity and the mouse oedema elicited by carrageenan, bradykinin, substance P, histamine and platelet-activating factor. It also prevented carrageenan-evoked exudation and the neutrophil influx to the rat pleura and the neutrophil migration into carrageenan-stimulated mouse air pouches. Moreover, Cordia verbenacea oil inhibited the oedema caused by Apis mellifera venom or ovalbumin in sensitized rats and ovalbumin-evoked allergic pleurisy. The essential oil significantly decreased TNFalpha, without affecting IL-1beta production, in carrageenan-injected rat paws. Neither the PGE(2) formation after intrapleural injection of carrageenan nor the COX-1 or COX-2 activities in vitro were affected by the essential oil. Of high interest, the paw edema induced by carrageenan in mice was markedly inhibited by both sesquiterpenic compounds obtained from the essential oil: alpha-humulene and trans-caryophyllene (50mg/kg, p.o.). Collectively, the present results showed marked anti-inflammatory effects for the essential oil of Cordia verbenacea and some active compounds, probably by interfering with TNFalpha production. Cordia verbenacea essential oil or its constituents might represent new therapeutic options for the treatment of inflammatory diseases.

Towards Designing Graceful Degradation into Trajectory Based Operations: A Human-systems Integration Approach

Science.gov (United States)

Edwards, Tamsyn; Lee, Paul

2017-01-01

One of the most fundamental changes to the air traffic management system in NextGen is the concept of trajectory based operations (TBO). With the introduction of such change, system safety and resilience is a critical concern, in particular, the ability of systems to gracefully degrade. In order to design graceful degradation into a TBO envrionment, knowledge of the potential causes of degradation, and appropriate solutions, is required. In addition, previous research has predominantly explored the technological contribution to graceful degradation, frequently neglecting to consider the role of the human operator, specifically, air traffic controllers (ATCOs). This is out of step with real-world operations, and potentially limits an ecologically valid understanding of achieving graceful degradation in an air traffic control (ATC) environment. The following literature review aims to identify and summarize the literature to date on the potential causes of degradation in ATC and the solutions that may be applied within a TBO context, with a specific focus on the contribution of the air traffic controller. A framework of graceful degradation, developed from the literature, is presented. It is argued that in order to achieve graceful degradation within TBO, a human-system integration approach must be applied.

Simulated degradation of biochar and its potential environmental implications

International Nuclear Information System (INIS)

Liu, Zhaoyun; Demisie, Walelign; Zhang, Mingkui

2013-01-01

A simulated oxidation technique was used to examine the impacts of degradation on the surface properties of biochar and the potential implications of the changes in biochar properties were discussed. To simulate the short- and long-term environmental degradation, mild and harsh degradation were employed. Results showed that after mild degradation, the biochar samples showed significant reductions in surface area and pore volumes. After harsh degradation, the biochar samples revealed dramatic variations in their surface chemistry, surface area, pore volumes, morphology and adsorption properties. The results clearly indicate that changes of biochar surface properties were affected by biochar types and oxidative conditions. It is suggested that biochar surface properties are likely to be gradually altered during environmental exposure. This implies that these changes have potential effects for altering the physicochemical properties of biochar amended soils. -- Highlights: •Mild and harsh degradation were employed to simulate natural degradation of biochar. •Mild degradation could reduce the surface area and micropore volumes of biochar. •Harsh degradation caused severe changes of all of the biochar surface properties. •Biochar types and oxidative conditions may dominate the changes of its properties. -- The simulated degradation of biochar in this study could provide a mechanism for forecasting short- or long-term environmental degradation of biochar

In vitro Degradation of Butanediamine-Grafted Poly(DL-Lactic acids)

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

The degradation of butanediamine-grafted poly(DL-lactic acid) polymers (BDPLAs) in vitro together with PDLLA and maleic anhydride-grafted poly(DL-lactic acid) polymers (MPLAs) was investigated by observation of the changes of the pH value of incubation media, and weight loss ratio during degradation duration of 12 weeks. The results reveal that the acidity of PDLLA degradation products was weakened or neutralized by grafting butanediamine onto PDLLA. A uniform degradation of BDPLAs was observed in comparison with an acidity-induced auto-accelerating degradation featured by PDLLA and MPLAs. The biodegradation behaviors of BDPLAs can be adjusted by controlling the content of BDA. BDPLAs might be a new derivative of PDLLA-based biodegradable materials for medical applications without acidity-caused irritations and acidity-induced auto-accelerating degradation behavior as that of PDLLA.

Detecting and monitoring deforestation and forest degradation: Issues and obstacles for Southeast Asia

Science.gov (United States)

Douglas Muchoney; Sharon Hamann

2013-01-01

Forest degradation can be defined as the loss of forest volume, biomass and/or forest productivity caused by natural or human influences. Achieving Reduced Emissions from Deforestation and Forest Degradation (REDD+) requires that deforestation and degradation can be efficiently, reliably, and cost-effectively detected and quantified, often where ground and aerial...

Fermentation optimization and enzyme characterization of a new ι-Carrageenase from Pseudoalteromonas carrageenovora ASY5

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Qiong Xiao

2018-03-01

Full Text Available Background: A new ι-carrageenase-producing strain was screened from mangroves and authenticated as Pseudoalteromonas carrageenovora ASY5 in our laboratory. The potential application of this new strain was evaluated. Results: Medium compositions and culturing conditions in shaking flask fermentation were firstly optimized by single-factor experiment. ι-Carrageenase activity increased from 0.34 U/mL to 1.08 U/mL after test optimization. Optimal fermentation conditions were 20°C, pH 7.0, incubation time of 40 h, 15 g/L NaCl, 1.5% (w/v yeast extract as nitrogen source, and 0.9% (w/v ι-carrageenan as carbon source. Then, the crude ι-carrageenase was characterized. The optimum temperature and pH of the ι-carrageenase were 40°C and 8.0, respectively. The enzymatic activity at 35–40°C for 45 min retained more than 40% of the maximum activity. Meanwhile, The ι-carrageenase was inhibited by the addition of 1 mmol/L Cd2+ and Fe3+ but increased by the addition of 1 mmol/L Ag+, Ba2+, Ca2+, Co2+, Mn2+, Zn2+, Fe2+, and Al3+. The structure of oligosaccharides derived from ι-carrageenan was detected using electrospray ionization mass spectrometry (ESI-MS. The ι-carrageenase degraded ι-carrageenan, yielding disaccharides and tetrasaccharides as main products. Conclusions: The discovery and study of new ι-carrageenases are beneficial not only for the production of ι-carrageenan oligosaccharides but also for the further utilization in industrial production. Keywords: Disaccharides, Electrospray ionization mass spectrometry (ESI-MS, Enzyme properties, Fermentation optimization, Galactans, Pseudoalteromonas carrageenovora, Sulfated linear polysaccharides, Tetrasaccharides, ι-Carrageenan oligosaccharides, ι-Carrageenan, ι-Carrageenase-producing strain

Electroacupuncture Reduces Carrageenan- and CFA-Induced Inflammatory Pain Accompanied by Changing the Expression of Nav1.7 and Nav1.8, rather than Nav1.9, in Mice Dorsal Root Ganglia.

Science.gov (United States)

Huang, Chun-Ping; Chen, Hsiang-Ni; Su, Hong-Lin; Hsieh, Ching-Liang; Chen, Wei-Hsin; Lai, Zhen-Rung; Lin, Yi-Wen

2013-01-01

Several voltage-gated sodium channels (Navs) from nociceptive nerve fibers have been identified as important effectors in pain signaling. The objective of this study is to investigate the electroacupuncture (EA) analgesia mechanism by changing the expression of Navs in mice dorsal root ganglia (DRG). We injected carrageenan and complete Freund's adjuvant (CFA) into the mice plantar surface of the hind paw to induce inflammation and examined the antinociception effect of EA at the Zusanli (ST36) acupoint at 2 Hz low frequency. Mechanical hyperalgesia was evaluated by using electronic von Frey filaments, and thermal hyperalgesia was assessed using Hargreaves' test. Furthermore, we observed the expression and quality of Navs in DRG neurons. Our results showed that EA reduced mechanical and thermal pain in inflammatory animal model. The expression of Nav1.7 and Nav1.8 was increased after 4 days of carrageenan- and CFA-elicited inflammatory pain and further attenuated by 2 Hz EA stimulation. The attenuation cannot be observed in Nav1.9 sodium channels. We demonstrated that EA at Zusanli (ST36) acupoint at 2 Hz low-frequency stimulation attenuated inflammatory pain accompanied by decreasing the expression of Nav1.7 and 1.8, rather than Nav1.9, sodium channels in peripheral DRG neurons.

Isolation of nitrite-degrading strains from Douchi and their application to degrade high nitrite in Jiangshui.

Science.gov (United States)

Guo, Xing; Liu, Bianfang; Gao, Lina; Zhou, Yuan; Shan, Yuanyuan; Lü, Xin

2018-06-01

Excessive nitrite in food is potentially harmful to human health because of its carcinogenic effects caused by nitroso-dervivatives. Douchi, which widely distributed throughout the country, is a traditional solid fermented soybean food with low nitrite content. In this study, bacterias which can degrade nitrite were isolated from Douchi and identified according to 16S rDNA sequence. Acinetobacter guillouiae, Acinetobacter bereziniae, Bacillus subtilis, Bacillus tequilensis, Bacillus amyloliquefaciens, Bacillus licheniformis, Bacillus aryabhattai and Bacillus methylotrophicus were selected. It was shown that all strains have nitrite degradation capability, in which 99.41 % nitrite can be degraded by Bacillus subtilis NDS1. The enzyme activities of these strains were determined at 24 h and 48 h, which corresponded to their nitrite degradation rates. The strains were firstly tried to inoculate in Jiangshui, which is a kind of traditional fermented vegetable in northwest China and often has high nitrite content. It was found that Bacillus subtilis NDS1, Bacillus tequilensis NDS3, Acinetobacter bereziniae NDS4, Bacillus subtilis NDS6, Bacillus subtilis NDS12 can degrade nitrite in Jiangshui more quickly, among which Acinetobacter bereziniae NDS4 degraded almost all nitrite in 48 h while it took 180 h for control. These results indicated that the selected strains have potential to become nitrite degradition agent in food. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Stabilization and Degradation Mechanisms of Cytoplasmic Ataxin-1

Directory of Open Access Journals (Sweden)

Mayumi F. Kohiyama

2015-01-01

Full Text Available Aggregation-prone proteins in neurodegenerative disease disrupt cellular protein stabilization and degradation pathways. The neurodegenerative disease spinocerebellar ataxia type 1 (SCA1 is caused by a coding polyglutamine expansion in the Ataxin-1 gene ( ATXN1 , which gives rise to the aggregation-prone mutant form of ATXN1 protein. Cerebellar Purkinje neurons, preferentially vulnerable in SCA1, produce ATXN1 protein in both cytoplasmic and nuclear compartments. Cytoplasmic stabilization of ATXN1 by phosphorylation and 14-3-3-mediated mechanisms ultimately drive translocation of the protein to the nucleus where aggregation may occur. However, experimental inhibition of phosphorylation and 14-3-3 binding results in rapid degradation of ATXN1, thus preventing nuclear translocation and cellular toxicity. The exact mechanism of cytoplasmic ATXN1 degradation is currently unknown; further investigation of degradation may provide future therapeutic targets. This review examines the present understanding of cytoplasmic ATXN1 stabilization and potential degradation mechanisms during normal and pathogenic states.

Carrageenan activates monocytes via type-specific binding with interleukin-8: an implication for design of immuno-active biomaterials.

Science.gov (United States)

Chan, Weng-I; Zhang, Guangpan; Li, Xin; Leung, Chung-Hang; Ma, Dik-Lung; Dong, Lei; Wang, Chunming

2017-02-28

Polymers that can activate the immune system may become useful biomaterials tools, given that the mechanisms underlying their actions are well understood. Herein, we report a novel type of interaction between polymers and immune cells - in studying the influence of the three major types of carrageenan (CGN) polysaccharides on monocyte behaviour in vitro, we found only the λ-type induced monocyte adhesion and this action requires the presence of an adequate amount of serum. Further analyses indicated λ-CGN bound interleukin-8 (IL-8) in the serum and activated the cultured monocytes through an IL-8-dependent pathway. This is the first demonstration that a polymer, with a renowned immunostimulatory effect, activates the immune system via binding and harnessing the function of a specific cytokine in the microenvironment. This is a new mechanism underlying polymer-immunity interactions that may shed light on future design and application of biomaterials tools targeting the immune system for a wide variety of therapeutic applications.

Wind Erosion Induced Soil Degradation in Northern China: Status, Measures and Perspective

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Zhongling Guo

2014-12-01

Full Text Available Soil degradation is one of the most serious ecological problems in the world. In arid and semi-arid northern China, soil degradation predominantly arises from wind erosion. Trends in soil degradation caused by wind erosion in northern China frequently change with human activities and climatic change. To decrease soil loss by wind erosion and enhance local ecosystems, the Chinese government has been encouraging residents to reduce wind-induced soil degradation through a series of national policies and several ecological projects, such as the Natural Forest Protection Program, the National Action Program to Combat Desertification, the “Three Norths” Shelter Forest System, the Beijing-Tianjin Sand Source Control Engineering Project, and the Grain for Green Project. All these were implemented a number of decades ago, and have thus created many land management practices and control techniques across different landscapes. These measures include conservation tillage, windbreak networks, checkerboard barriers, the Non-Watering and Tube-Protecting Planting Technique, afforestation, grassland enclosures, etc. As a result, the aeolian degradation of land has been controlled in many regions of arid and semiarid northern China. However, the challenge of mitigating and further reversing soil degradation caused by wind erosion still remains.

Degradation Behavior of Thermal Stabilized Polyacrylonitrile Fibers

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LEI Shuai

2017-05-01

Full Text Available In the temperature range of 300-800℃, 40%-50% of the mass lost during the processing of polyacrylonitrile based carbon fiber (PANCF. Understanding the degradation behavior will be valuable in understanding the formation mechanism of pseudo-graphite structure, and providing theoretic basis for producing high performance carbon fiber and increasing the carbonization yield. The simulation of the degradation progress was carried out on the thermogravimetric analyzer (TGA, the results show that there are two degradation steps for PAN fiber stabilized in air, and controlled by cyclization coefficient and oxygen content. The cyclization coefficient and oxygen content are effective to the density of carbon fiber by influencing the degradation behavior, which cause defects in the fiber. The higher cyclization coefficient leads to form less structural defects and higher density of the fiber; on the contrary, the higher oxygen content leads to form more structural defects and lower density of the fiber.

Aflatoxin B1 Degradation by a Pseudomonas Strain

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Lancine Sangare

2014-10-01

Full Text Available Aflatoxin B1 (AFB1, one of the most potent naturally occurring mutagens and carcinogens, causes significant threats to the food industry and animal production. In this study, 25 bacteria isolates were collected from grain kernels and soils displaying AFB1 reduction activity. Based on its degradation effectiveness, isolate N17-1 was selected for further characterization and identified as Pseudomonas aeruginosa. P. aeruginosa N17-1 could degrade AFB1, AFB2 and AFM1 by 82.8%, 46.8% and 31.9% after incubation in Nutrient Broth (NB medium at 37 °C for 72 h, respectively. The culture supernatant of isolate N17-1 degraded AFB1 effectively, whereas the viable cells and intra cell extracts were far less effective. Factors influencing AFB1 degradation by the culture supernatant were investigated. Maximum degradation was observed at 55 °C. Ions Mn2+ and Cu2+ were activators for AFB1 degradation, however, ions Mg2+, Li+, Zn2+, Se2+, Fe3+ were strong inhibitors. Treatments with proteinase K and proteinase K plus SDS significantly reduced the degradation activity of the culture supernatant. No degradation products were observed based on preliminary LC-QTOF/MS analysis, indicating AFB1 was metabolized to degradation products with chemical properties different from that of AFB1. The results indicated that the degradation of AFB1 by P. aeruginosa N17-1 was enzymatic and could have a great potential in industrial applications. This is the first report indicating that the isolate of P. aeruginosa possesses the ability to degrade aflatoxin.

Iron-Binding Protein Degradation by Cysteine Proteases of Naegleria fowleri

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Moisés Martínez-Castillo

2015-01-01

Full Text Available Naegleria fowleri causes acute and fulminant primary amoebic meningoencephalitis. This microorganism invades its host by penetrating the olfactory mucosa and then traveling up the mesaxonal spaces and crossing the cribriform plate; finally, the trophozoites invade the olfactory bulbs. During its invasion, the protozoan obtains nutrients such as proteins, lipids, carbohydrates, and cationic ions (e.g., iron, calcium, and sodium from the host. However, the mechanism by which these ions are obtained, particularly iron, is poorly understood. In the present study, we evaluated the ability of N. fowleri to degrade iron-binding proteins, including hololactoferrin, transferrin, ferritin, and hemoglobin. Zymography assays were performed for each substrate under physiological conditions (pH 7 at 37°C employing conditioned medium (CM and total crude extracts (TCEs of N. fowleri. Different degradation patterns with CM were observed for hololactoferrin, transferrin, and hemoglobin; however, CM did not cause ferritin degradation. In contrast, the TCEs degraded only hololactoferrin and transferrin. Inhibition assays revealed that cysteine proteases were involved in this process. Based on these results, we suggest that CM and TCEs of N. fowleri degrade iron-binding proteins by employing cysteine proteases, which enables the parasite to obtain iron to survive while invading the central nervous system.

Towards Designing Graceful Degradation into Trajectory Based Operations: A Human-Machine System Integration Approach

Science.gov (United States)

Edwards, Tamsyn; Lee, Paul

2017-01-01

One of the most fundamental changes to the air traffic management system in NextGen is the concept of trajectory based operations (TBO). With the introduction of such change, system safety and resilience is a critical concern, in particular, the ability of systems to gracefully degrade. In order to design graceful degradation into a TBO envrionment, knowledge of the potential causes of degradation, and appropriate solutions, is required. In addition, previous research has predominantly explored the technological contribution to graceful degradation, frequently neglecting to consider the role of the human operator, specifically, air traffic controllers (ATCOs). This is out of step with real-world operations, and potentially limits an ecologically valid understanding of achieving graceful degradation in an air traffic control (ATC) environment. The following literature review aims to identify and summarize the literature to date on the potential causes of degradation in ATC and the solutions that may be applied within a TBO context, with a specific focus on the contribution of the air traffic controller. A framework of graceful degradation, developed from the literature, is presented. It is argued that in order to achieve graceful degradation within TBO, a human-system integration approach must be applied.

Degradation properties of the electrostatic assembly PDLLA/CS/CHS nerve conduit

Energy Technology Data Exchange (ETDEWEB)

Xu Haixing [School of Chemical Engineering, Wuhan University of Technology, Wuhan 430070 (China); Yan Yuhua; Wan Tao; Li Shipu, E-mail: yanyuhua8@126.co [Biomedical Materials and Engineering Research Center, Wuhan University of Technology, Wuhan 430070 (China)

2009-08-15

A poly(d,l-lactic acid)/chondroitin sulfate/chitosan (PDLLA/CS/CHS) nerve conduit for repairing nerve defects was prepared by electrostatic assembly and the thermally induced phase separation technique. The hydrophilic characteristics of the PDLLA/CS/CHS assembly nerve conduits were improved markedly. The degradation behavior of the nerve conduit with various assembly layers was evaluated by a pH change, weight loss rate and molecular weight change. The pH of the solution of the nerve conduit could be effectively adjusted by varying the layer numbers and overcoming the acidity-caused auto-acceleration of PDLLA; the nerve conduit can retain its integrity in a phosphate buffer solution after being degraded for 3 months. After such a conduit was implanted in the rat for 3 months, obvious degradation occurred, but the regenerated nerve was integrated and it grew successfully from the proximal to distal nerve stump. All these results implied that the degradation rate of the prepared conduit can adapt to the regeneration of the peripheral nerve, which might be a new derivative of PDLLA-based biodegradable materials for repairing nerve injuries without acidity-caused irritations and acidity-induced auto-accelerating degradation behavior as shown by PDLLA.

Fungal degradation of polyhydroxyalkanoates and a semiquantitative assay for screening their degradation by terrestrial fungi.

Science.gov (United States)

Matavulj, M; Molitoris, H P

1992-12-01

The current problems with decreasing fossile resources and increasing environmental pollution by petrochemical-based plastics have stimulated investigations to find biosynthetic materials which are also biodegradable. Bacterial reserve materials such as polyhydroxyalkanoates (PHA) have been discovered to possess thermoplastic properties and can be synthesized from renewable resources. Poly-beta-hydroxybutyric acid (PHB) is at present the most promising PHA; and BIOPOL, its copolymer with poly-beta-hydroxy-valerate (PHV), is already industrially produced (ICI, UK), and used as packaging material (WELLA, FRG). According to the literature, PHA degradation has so far mainly been observed in bacteria; only under certain environmental conditions has fungal degradation of PHAs been indicated. Since fungi constitute an important part of microbial populations participating in degradation processes, a simple screening method for fungal degradation of BIOPOL, a PHA-based plastic, was developed. Several media with about 150 fungal strains from different terrestrial environments and belonging to different systematic and ecological groups were used. PHA depolymerization was tested on three PHB-based media, each with 0.1% BIOPOL or PHB homopolymer causing turbidity of the medium. The media contained either a comparatively low or high content of organic carbon (beside PHA) or were based on mineral medium with PHA as the principal source of carbon. The degradation activity was detectable due to formation of a clear halo around the colony (Petri plates) or a clear zone under the colony (test tubes).(ABSTRACT TRUNCATED AT 250 WORDS)

40 CFR 125.122 - Determination of unreasonable degradation of the marine environment.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Determination of unreasonable degradation of the marine environment. 125.122 Section 125.122 Protection of Environment ENVIRONMENTAL... environment. (a) The director shall determine whether a discharge will cause unreasonable degradation of the...

Degradation of hydrocarbons in arctic areas

International Nuclear Information System (INIS)

Hundahl Pedersen, M.; Grau-Hansen, B.; Watson Nielsen, T.; Jensen, L.

1999-12-01

The scope of this project is to examine the natural degradation of a hydrocarbon contamination by investigating a specific location. The investigated location is a former airfield at Marraq situated on the west coast of Greenland, approx. 90 km south of Nuuk. In Autumn 1942 the US Air force established a diversion airfield called 'Teague Airfield' - under the military code name Bluie West-4. However, the location was abandoned in 1948 and accordingly all facilities and equipment were left behind, among these were a large amount of oil barrels, which mainly contained gas oil. In relation to the present investigation a number of disposal sites were found each containing approx. 50-600 oil barrels of 200 litres each. Through the years these barrels have corroded causing a heavy gas oil contamination several places on the site. This contamination is estimated to have taken place for approx. 40-50 years ago. The contamination is of such a severe character that a heavy smell of oil can be determined on site. Furthermore, vegetation mortality was observed around the barrels in connection to disposal sites situated in places covered by plants. Marraq is a peninsula consisting of coarse fluviatile deposits. The geology is relatively homogeneous without permafrost, which combined with a range of local defined contaminations, provide a unique possibility to assess the controlling environmental factors of natural degradation of oil contamination in the Arctic. A conservative estimate of the complete amount of gas oil which has contaminated the location is estimated to approx. 120,000 litres or more. The investigation showed that the extent of the oil degradation was different at the individual deposit sites. Roughly estimated the contamination is degraded on the order of 15 to twice the original oil amount. Assumable the contamination has been degraded due to the weathering process (evaporation and wash-out) and microbial degradation. Complex processes are involved depending

Polymers selection for a liquid inoculant of Azospirillum brasilense ...

African Journals Online (AJOL)

In this study, we used a method of accelerated degradation to select a polymer and a concentration to maintain cell stability of a liquid inoculant based on the strain C16 Azospirillum brasilense. A screening at 45°C was made to compare the protectant effect of five polymers on the viability of the strain (p/v): carrageenan ...

Hemostatic granules and dressing prepared from formulations of carboxymethyl cellulose, kappa-carrageenan and polyethylene oxide crosslinked by gamma radiation

Science.gov (United States)

Barba, Bin Jeremiah D.; Aranilla, Charito T.; Relleve, Lorna S.; Cruz, Veriza Rita C.; Vista, Jeanina Richelle; Abad, Lucille V.

2018-03-01

Uncontrolled hemorrhage remains a persistent problem especially in anatomical areas where compression and tourniquet cannot be applied. Hemostatic agents are materials which can achieve control of bleeding in acute, life-threatening traumatic coagulopathy. In this study, we prepared biocompatible hydrogel-based hemostat crosslinked by ionizing radiation. Granules made from carboxymethyl cellulose and dressing from kappa carrageenan and polyethylene oxide were characterized by FT-IR, SEM, and gel analysis. Gamma radiation with a dose of 25 kGy was used for sterilization process. Stability studies indicate that the products remain effective with a shelf life of up to 18 months based on accelerated aging. Both hemostatic agents were demonstrated to be effective in vitro blood clotting assays showing a low blood clotting index, high platelet adhesion capacity and accelerated clotting time. Hemostat granules and dressing were also used in a femoral artery rat bleeding model where hemorrhage control was achieved in 90 s without compression and resulted in 100% survival rate after a 7 and 14-day observation.

Status of peatland degradation and development in Sumatra and Kalimantan.

Science.gov (United States)

Miettinen, Jukka; Liew, Soo Chin

2010-01-01

Peatlands cover around 13 Mha in Sumatra and Kalimantan, Indonesia. Human activities have rapidly increased in the peatland ecosystems during the last two decades, invariably degrading them and making them vulnerable to fires. This causes high carbon emissions that contribute to global climate change. For this article, we used 94 high resolution (10-20 m) satellite images to map the status of peatland degradation and development in Sumatra and Kalimantan using visual image interpretation. The results reveal that less than 4% of the peatland areas remain covered by pristine peatswamp forests (PSFs), while 37% are covered by PSFs with varying degree of degradation. Furthermore, over 20% is considered to be unmanaged degraded landscape, occupied by ferns, shrubs and secondary growth. This alarming extent of degradation makes peatlands vulnerable to accelerated peat decomposition and catastrophic fire episodes that will have global consequences. With on-going degradation and development the existence of the entire tropical peatland ecosystem in this region is in great danger.

Kinetics approach to modeling of polymer additive degradation in lubricants

Institute of Scientific and Technical Information of China (English)

llyaI.KUDISH; RubenG.AIRAPETYAN; Michael; J.; COVITCH

2001-01-01

A kinetics problem for a degrading polymer additive dissolved in a base stock is studied.The polymer degradation may be caused by the combination of such lubricant flow parameters aspressure, elongational strain rate, and temperature as well as lubricant viscosity and the polymercharacteristics (dissociation energy, bead radius, bond length, etc.). A fundamental approach tothe problem of modeling mechanically induced polymer degradation is proposed. The polymerdegradation is modeled on the basis of a kinetic equation for the density of the statistical distribu-tion of polymer molecules as a function of their molecular weight. The integrodifferential kineticequation for polymer degradation is solved numerically. The effects of pressure, elongational strainrate, temperature, and lubricant viscosity on the process of lubricant degradation are considered.The increase of pressure promotes fast degradation while the increase of temperature delaysdegradation. A comparison of a numerically calculated molecular weight distribution with an ex-perimental one obtained in bench tests showed that they are in excellent agreement with eachother.

Performance degradation of integrated optical modulators due to electrical crosstalk

NARCIS (Netherlands)

Yao, W.; Gilardi, G.; Smit, M.K.; Wale, M.J.

2016-01-01

In this paper, we investigate electrical crosstalk in integrated Mach-Zehnder modulator arrays based on n-doped InP substrate and show that it can be the cause for transmitter performance degradations. In particular, a common ground return path between adjacent modulators can cause high coupling

Degradable polyphosphazene/poly(alpha-hydroxyester) blends: degradation studies.

Science.gov (United States)

Ambrosio, Archel M A; Allcock, Harry R; Katti, Dhirendra S; Laurencin, Cato T

2002-04-01

Biomaterials based on the polymers of lactic acid and glycolic acid and their copolymers are used or studied extensively as implantable devices for drug delivery, tissue engineering and other biomedical applications. Although these polymers have shown good biocompatibility, concerns have been raised regarding their acidic degradation products, which have important implications for long-term implantable systems. Therefore, we have designed a novel biodegradable polyphosphazene/poly(alpha-hydroxyester) blend whose degradation products are less acidic than those of the poly(alpha-hydroxyester) alone. In this study, the degradation characteristics of a blend of poly(lactide-co-glycolide) (50:50 PLAGA) and poly[(50% ethyl glycinato)(50% p-methylphenoxy) phosphazene] (PPHOS-EG50) were qualitatively and quantitatively determined with comparisons made to the parent polymers. Circular matrices (14mm diameter) of the PLAGA, PPHOS-EG50 and PLAGA-PPHOS-EG50 blend were degraded in non-buffered solutions (pH 7.4). The degraded polymers were characterized for percentage mass loss and molecular weight and the degradation medium was characterized for acid released in non-buffered solutions. The amounts of neutralizing base necessary to bring about neutral pH were measured for each polymer or polymer blend during degradation. The poly(phosphazene)/poly(lactide-co-glycolide) blend required significantly less neutralizing base in order to bring about neutral solution pH during the degradation period studied. The results indicated that the blend degraded at a rate intermediate to that of the parent polymers and that the degradation products of the polyphosphazene neutralized the acidic degradation products of PLAGA. Thus, results from these in vitro degradation studies suggest that the PLAGA-PPHOS-EG50 blend may provide a viable improvement to biomaterials based on acid-releasing organic polymers.

Proliferating effect of radiolytically depolymerized carrageenan on physiological attributes, plant water relation parameters, essential oil production and active constituents of Cymbopogon flexuosus Steud. under drought stress.

Science.gov (United States)

Singh, Minu; Khan, M Masroor A; Uddin, Moin; Naeem, M; Qureshi, M Irfan

2017-01-01

Carrageenan has been proved as potent growth promoting substance in its depolymerized form. However, relatively little is known about its role in counteracting the adverse effects of drought stress on plants. In a pot experiment, lemongrass (Cymbopogon flexuosus Steud.), grown under different water stress regimes [(100% field capacity (FC), 80% FC and 60% FC)], was sprayed with 40, 80 and 120 mg L-1 of gamma irradiated carrageenan (ICA). Foliar application of ICA mitigated the harmful effects of drought stress to various extents and improved the biochemical characteristics, quality attributes and active constituents (citral and geraniol) of lemongrass significantly. Among the applied treatments, ICA-80 mg L-1 proved the best in alleviating detrimental effects of drought. However, drought stress (80 and 60% FC), irrespective of the growth stages, had an adverse impact on most of the studied attributes. Generally, 60% FC proved more deleterious than 80% FC. At 80% FC, application of ICA-80 mg L-1 elevated the essential oil (EO) content by 18.9 and 25%, citral content by 7.33 and 8.19% and geraniol content by 9.2 and 8.9% at 90 and 120 days after planting (DAP), respectively, as compared to the deionized-water (DW) spray treatment (80% FC+ DW). Whereas, at 60% FC, foliar application of 80 mg L-1 ICA significantly augmented the EO content by 15.4 and 17.8% and active constituents viz. citral and geraniol, by 5.01 and 5.62% and by 6.06 and 5.61% at 90 and 120 DAP, respectively, as compared to the control (water-spray treatment).

Proliferating effect of radiolytically depolymerized carrageenan on physiological attributes, plant water relation parameters, essential oil production and active constituents of Cymbopogon flexuosus Steud. under drought stress.

Directory of Open Access Journals (Sweden)

Minu Singh

Full Text Available Carrageenan has been proved as potent growth promoting substance in its depolymerized form. However, relatively little is known about its role in counteracting the adverse effects of drought stress on plants. In a pot experiment, lemongrass (Cymbopogon flexuosus Steud., grown under different water stress regimes [(100% field capacity (FC, 80% FC and 60% FC], was sprayed with 40, 80 and 120 mg L-1 of gamma irradiated carrageenan (ICA. Foliar application of ICA mitigated the harmful effects of drought stress to various extents and improved the biochemical characteristics, quality attributes and active constituents (citral and geraniol of lemongrass significantly. Among the applied treatments, ICA-80 mg L-1 proved the best in alleviating detrimental effects of drought. However, drought stress (80 and 60% FC, irrespective of the growth stages, had an adverse impact on most of the studied attributes. Generally, 60% FC proved more deleterious than 80% FC. At 80% FC, application of ICA-80 mg L-1 elevated the essential oil (EO content by 18.9 and 25%, citral content by 7.33 and 8.19% and geraniol content by 9.2 and 8.9% at 90 and 120 days after planting (DAP, respectively, as compared to the deionized-water (DW spray treatment (80% FC+ DW. Whereas, at 60% FC, foliar application of 80 mg L-1 ICA significantly augmented the EO content by 15.4 and 17.8% and active constituents viz. citral and geraniol, by 5.01 and 5.62% and by 6.06 and 5.61% at 90 and 120 DAP, respectively, as compared to the control (water-spray treatment.

Reduction of entanglement degradation in Einstein-Gauss-Bonnet gravity

International Nuclear Information System (INIS)

Nasr Esfahani, B.; Shamirzaie, M.; Soltani, M.

2011-01-01

Bipartite entanglement for states of a noninteracting bosonic or fermionic field in the spacetime of a spherically symmetric black hole of Einstein-Gauss-Bonnet gravity is investigated. Although the initial state is chosen to be maximally entangled as the Bell states, the Hawking-Unruh effect causes the state to be mixed and the entanglement degrades, but with different asymptotic behaviors for the fermionic and bosonic fields. The Gauss-Bonnet term with positive α can play an antigravitation role and so this causes a decrease in the Hawking-Unruh effect and consequently reduces the entanglement degradation. On the other hand, the suggested higher dimensions for the spacetime lead to increased entanglement degradation by increasing the dimension. There is a dramatic difference between the behaviors of the entanglement in terms of the radius of the horizon for a five-dimensional black hole and that for higher dimensional black holes. Both bosonic and fermionic fields entanglements are treated beyond the single-mode approximation. Also, the cases where the accelerating observers located at regions near and far from the event horizon of black hole are studied separately.

Toxicological aspects of photocatalytic degradation of selected xenobiotics with nano-sized Mn-doped TiO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Ozmen, Murat, E-mail: murat.ozmen@inonu.edu.tr [Inonu University, Faculty of Science, Department of Biology, Malatya (Turkey); Güngördü, Abbas [Inonu University, Faculty of Science, Department of Biology, Malatya (Turkey); Erdemoglu, Sema [Inonu University, Faculty of Science, Department of Chemistry, Malatya (Turkey); Ozmen, Nesrin [Inonu University, Faculty of Education, Department of Science Teaching Program, Malatya (Turkey); Asilturk, Meltem [Akdeniz University, Department of Materials Science and Engineering, Antalya (Turkey)

2015-08-15

Highlights: • Undoped and Mn-doped TiO{sub 2} nanoparticles were synthesized and characterized. • The photocatalytic efficiency of the photocatalysts was evaluated for BPA and ATZ. • Toxicity of photocatalysts and photocatalytic by-products were determined. • Mn-doped TiO{sub 2} nanoparticles did not cause significant lethality on X. laevis. • Degradation of BPA caused a significant reduction of lethal effects. - Abstract: The toxic effects of two selected xenobiotics, bisphenol A (BPA) and atrazine (ATZ), were evaluated after photocatalytic degradation using nano-sized, Mn-doped TiO{sub 2}. Undoped and Mn-doped TiO{sub 2} nanoparticles were synthesized. The samples were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), UV–vis-diffuse reflectance spectra (DRS), X-ray fluorescence spectroscopy (XRF), and BET surface area. The photocatalytic efficiency of the undoped and Mn-doped TiO{sub 2} was evaluated for BPA and ATZ. The toxicity of the synthesized photocatalysts and photocatalytic by-products of BPA and ATZ was determined using frog embryos and tadpoles, zebrafish embryos, and bioluminescent bacteria. Possible toxic effects were also evaluated using selected enzyme biomarkers. The results showed that Mn-doped TiO{sub 2} nanoparticles did not cause significant lethality in Xenopus laevis embryos and tadpoles, but nonfiltered samples caused lethality in zebrafish. Furthermore, Mn-doping of TiO{sub 2} increased the photocatalytic degradation capability of nanoparticles, and it successfully degraded BPA and AZT, but degradation of AZT caused an increase of the lethal effects on both tadpoles and fish embryos. Degradation of BPA caused a significant reduction of lethal effects, especially after 2–4 h of degradation. However, biochemical assays showed that both Mn-doped TiO{sub 2} and the degradation by-products caused a significant change of selected biomarkers on X. laevis tadpoles; thus, the ecological risks of Mn

Soil degradation in Sub-Saharan Africa

NARCIS (Netherlands)

Hartemink, A.E.; Keulen, van H.

2005-01-01

Soil degradation in Sub-Sahara Africa has been much debated in the past decades. Although there are many different views, at the extremes there are those who are of the opinion that the problem is very serious and the main cause for the poverty and food crises and those that are convinced that it is

Degradation of cellulosic materials under the alkaline conditions of a cementitious repository for low- and intermediate level radioactive waste. Pt. III. Effect of degradation products on the sorption of radionuclides on feldspar

International Nuclear Information System (INIS)

Loon, L.R. van; Glaus, M.A.; Laube, A.; Stallone, S.

1999-01-01

The effect of degradation products of different cellulosic materials on the sorption behaviour of Th(IV), Eu(III) and Ni(II) on feldspar at pH 13.3 was studied. For all three metals, a decrease in sorption could be observed with increasing concentration of organics in solution. For Th(IV), α-ISA is the effective ligand present in the solutions of degraded cellulose, independent on the type of cellulose studied. For Eu(III), α-ISA is the effective ligand in the case of pure cellulose degradation. In the case of other cellulosic materials, unknown ligands cause the sorption reduction. For Ni(II), also unknown ligands cause sorption reduction, independent on the type of cellulose studied. These unknown ligands are not formed during alkaline degradation of cellulose, but are present as impurities in certain cellulosic materials. (orig.)

Atrazine degradation using chemical-free process of USUV: Analysis of the micro-heterogeneous environments and the degradation mechanisms

International Nuclear Information System (INIS)

Xu, L.J.; Chu, W.; Graham, Nigel

2014-01-01

Graphical abstract: - Highlights: • Two chemical-free AOP processes are combined to enhance atrazine degradation. • ATZ degradation in sonophotolytic process was analyzed using a previous proposed model. • The micro-bubble/liquid heterogeneous environments in sonolytic processes were investigated. • The salt effects on different sonolytic processes were examined. • ATZ degradation mechanisms were investigated and pathways were proposed. - Abstract: The effectiveness of sonolysis (US), photolysis (UV), and sonophotolysis (USUV) for the degradation of atrazine (ATZ) was investigated. An untypical kinetics analysis was found useful to describe the combined process, which is compatible to pseudo first-order kinetics. The heterogeneous environments of two different ultrasounds (20 and 400 kHz) were evaluated. The heterogeneous distribution of ATZ in the ultrasonic solution was found critical in determining the reaction rates at different frequencies. The presence of NaCl would promote/inhibit the rates by the growth and decline of “salting out” effect and surface tension. The benefits of combining these two processes were for the first time investigated from the aspect of promoting the intermediates degradation which were resistant in individual processes. UV caused a rapid transformation of ATZ to 2-hydroxyatrazine (OIET), which was insensitive to UV irradiation; however, US and USUV were able to degrade OIET and other intermediates through • OH attack. On the other hand, UV irradiation also could promote radical generation via H 2 O 2 decomposition, thereby resulting in less accumulation of more hydrophilic intermediates, which are difficult to degradation in the US process. Reaction pathways for ATZ degradation by all three processes are proposed. USUV achieved the greatest degree of ATZ mineralization with more than 60% TOC removed, contributed solely by the oxidation of side chains. Ammeline was found to be the only end-product in both US and USUV

Atrazine degradation using chemical-free process of USUV: Analysis of the micro-heterogeneous environments and the degradation mechanisms

Energy Technology Data Exchange (ETDEWEB)

Xu, L.J., E-mail: xulijie827@gmail.com [Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Chu, W., E-mail: cewchu@polyu.edu.hk [Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Graham, Nigel, E-mail: n.graham@imperial.ac.uk [Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom)

2014-06-30

Graphical abstract: - Highlights: • Two chemical-free AOP processes are combined to enhance atrazine degradation. • ATZ degradation in sonophotolytic process was analyzed using a previous proposed model. • The micro-bubble/liquid heterogeneous environments in sonolytic processes were investigated. • The salt effects on different sonolytic processes were examined. • ATZ degradation mechanisms were investigated and pathways were proposed. - Abstract: The effectiveness of sonolysis (US), photolysis (UV), and sonophotolysis (USUV) for the degradation of atrazine (ATZ) was investigated. An untypical kinetics analysis was found useful to describe the combined process, which is compatible to pseudo first-order kinetics. The heterogeneous environments of two different ultrasounds (20 and 400 kHz) were evaluated. The heterogeneous distribution of ATZ in the ultrasonic solution was found critical in determining the reaction rates at different frequencies. The presence of NaCl would promote/inhibit the rates by the growth and decline of “salting out” effect and surface tension. The benefits of combining these two processes were for the first time investigated from the aspect of promoting the intermediates degradation which were resistant in individual processes. UV caused a rapid transformation of ATZ to 2-hydroxyatrazine (OIET), which was insensitive to UV irradiation; however, US and USUV were able to degrade OIET and other intermediates through • OH attack. On the other hand, UV irradiation also could promote radical generation via H{sub 2}O{sub 2} decomposition, thereby resulting in less accumulation of more hydrophilic intermediates, which are difficult to degradation in the US process. Reaction pathways for ATZ degradation by all three processes are proposed. USUV achieved the greatest degree of ATZ mineralization with more than 60% TOC removed, contributed solely by the oxidation of side chains. Ammeline was found to be the only end-product in both US

Degradation of lithium ion batteries employing graphite negatives and nickel-cobalt-manganese oxide + spinel manganese oxide positives: Part 2, chemical-mechanical degradation model

Science.gov (United States)

Purewal, Justin; Wang, John; Graetz, Jason; Soukiazian, Souren; Tataria, Harshad; Verbrugge, Mark W.

2014-12-01

Capacity fade is reported for 1.5 Ah Li-ion batteries containing a mixture of Li-Ni-Co-Mn oxide (NCM) + Li-Mn oxide spinel (LMO) as positive electrode material and a graphite negative electrode. The batteries were cycled at a wide range of temperatures (10 °C-46 °C) and discharge currents (0.5C-6.5C). The measured capacity losses were fit to a simple physics-based model which calculates lithium inventory loss from two related mechanisms: (1) mechanical degradation at the graphite anode particle surface caused by diffusion-induced stresses (DIS) and (2) chemical degradation caused by lithium loss to continued growth of the solid-electrolyte interphase (SEI). These two mechanisms are coupled because lithium is consumed through SEI formation on newly exposed crack surfaces. The growth of crack surface area is modeled as a fatigue phenomenon due to the cyclic stresses generated by repeated lithium insertion and de-insertion of graphite particles. This coupled chemical-mechanical degradation model is consistent with the observed capacity loss features for the NCM + LMO/graphite cells.

Reversing an S-kink effect caused by interface degradation in organic solar cells through gold ion implantation in the PEDOT:PSS layer

Science.gov (United States)

Brenes-Badilla, D.; Coutinho, D. J.; Amorim, D. R. B.; Faria, R. M.; Salvadori, M. C.

2018-04-01

In this work, we performed a study on the recovery of the photovoltaic performance of an ITO/PEDOT:PSS/P3HT:PCBM/Ca/Al solar cell after the hole transport layer (PEDOT:PSS) had been degraded by contact with the environment. A device that was fully built in an inert environment exhibited a fill factor (FF) of 0.64, while the device whose hole transport layer was exposed to air presented a FF equal to 0.2. In addition, the J-V characteristic curve of the degraded device did not follow the photovoltaic pattern exhibiting the degenerate S shape. However, the elimination of the deleterious effect was achieved by bombarding gold ions on the contaminated surface of PEDOT:PSS by means of the Metal Plasma Immersion Ion Implantation technique. Due to the low energy of the ionic beam of gold, the implanted gold atoms were located at few nanometers off the surface, forming nanometric clusters, that is, gold nanoparticles. Most probably, the degradation of the J-V photovoltaic curve, represented by the S-kink effect, was caused by the appearance of a potential barrier at PEDOT:PSS/P3HT:PCBM interface, which was demolished by the gold nanoparticles that have work function close to HOMO of P3HT. This S-kink effect was also simulated by using an equivalent circuit model constituted by a two-diode circuit, one of which plays the role of the undesirable potential barrier formed at the PEDOT:PSS/P3HT:PCBM interface. Our analysis shows that deposition of gold nanoparticles next to the interface recovers the good hole injection condition from the PEDOT:PSS into the active layer, restoring the fill factor and the device efficiency.

Land Tenure Induced Deforestation and Environmental Degradation ...

African Journals Online (AJOL)

Land Tenure Induced Deforestation and Environmental Degradation in Ethiopia: The Case of Arbagugu State Forest Development and Protection Project (A ... The objective of this paper is to explore the cause and impact of this overarching problem by focusing on Arbagugu State Forest Development and Protection Project, ...

Reliability and corrosion induced degradation of electronic system

International Nuclear Information System (INIS)

Tapas, V.K.; Varde, P.V.

2014-01-01

This paper describe the corrosion induced degradation of electronic system failures due to environmental conditions such as humidity, temperature, ionic or organic contaminants, residuals; etc. which can accelerates as electrochemical reaction and causes corrosion of electronic components, Corrosive gases and water vapours from humid condition come into contact with the base metal results in buildup of various chemical reaction products. Ionic contamination responsible for electrochemical reaction, forms soluble complexes with metals, it can degrade the protective oxide film that forms on the positively biased metallization and/or lead to change in the local pH. Deterioration of metal components or electronic circuitry due to electrochemical migration needs to be controlled in order to reduce the corrosion. With explosive increase in demand and miniaturization in electronic system resulted in smaller components, closer spacing and thinner metallic path, it is expected that the corrosion and deterioration of electronic components may become cause or concern. This paper summarises the current understanding of chemistry behind possible causes of corrosion of electronic devices and its failure mechanism. (author)

Chromium related degradation of solid oxide fuel cells; Chrom-bezogene Degradation von Festoxid-Brennstoffzellen

Energy Technology Data Exchange (ETDEWEB)

Neumann, Anita

2011-05-04

Solid Oxide Fuel Cells (SOFCs) offer a high potential for application as an auxiliary power unit (APU) for heavy goods vehicles as well as combined heat and power (CHP) systems. SOFCs are especially attractive due to their high efficiencies and the use of different fuel types. However, optimization in terms of long term stability and costs are still necessary. This work characterized the degradation of SOFCs with lanthanum strontium manganite (LSM) cathodes under chromium influence. Galvanostatic cell tests were carried out at 800 C with operation times from 250 - 3000 h and variation of the chromium source and current density. The current densities of j = 0 (A)/(cm{sup 2}), j = 0,3 (A)/(cm{sup 2}) and j = 0,5 (A)/(cm{sup 2}) were applied. The high temperature ferritic alloy Crofer22APU was used as a chromium source. Variation of the chromium source was realized by coating the Crofer22APU insert with the chromium retention layer Mn{sub 3}O{sub 4} and the cathode contact layer LCC10. Cell degradation was analyzed with regard to cell voltage, current density and area specific resistance (ASR). Microstructural alterations of the cathode as well as chromium content and distribution across the cell were investigated after completion of the cell tests. For cells with a chromium source present and operation with a nonzero current density, the course of cell degradation was divided into three phases: a run-in, weak linear degradation and strong linear degradation. A decrease of the chromium release rate by means of different coatings stretched the course of degradation along the timescale. Strong degradation, which is characterized by a significant increase in ASR as well as a decrease of current density at the operating point, was only observed when a chromium source in the setup was comb ined with operation of the cell with a non-zero current density. Operation of the cell with a chromium source but no current density caused a degradation of current density at the

Effect of radiation and alkylating agents on chromatin degradation in normal and malignant lymphoid cells

International Nuclear Information System (INIS)

Ryabchenko, N.I.; Yurashkova, V.; Ivannik, B.P.; Konov, A.V.; Drashil, V.

1991-01-01

Regularities of chromatin degradation in thymocytes and LS/BL tumor cells have been investigated. It has been shown that the rate of DNA degradation by Ca/Mg-dependent endonuclease in LS/BL tumor cells is 25 times lower than that in thymocytes, and radiation does not induce chormatin degradation. The alkylating agent TS 160 causes chromatin degradation in both LS/Bl cells and thymocytes. In contrast to radiation TS 160 inhibits the endogenous chromatin degradation by Ca/Mg-dependent endonuclease in thymocytes

Relevance of rangeland degradation in semiarid Northeastern South Africa to the nonequilibrium theory

CSIR Research Space (South Africa)

Wessels, Konrad J

2007-04-01

Full Text Available degraded areas which have been mapped by the National Land Cover (NLC) program. Much evidence suggests that long-term heavy grazing is the cause of this degradation. In order to test for the prevalence of nonequilibrium dynamics, we determined the relative...

Utilization of polysaccharides by radiation processing

Energy Technology Data Exchange (ETDEWEB)

Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2000-03-01

Radiation treatment has been applied for improvement or pasteurization of agro-resources to recycle the resources and to reduce the pollution of environment. By using the radiation effect for pasteurization, upgrading of cellulosic wastes of oil palm to animal feeds and mushroom has been studied under the bilateral research cooperation between JAERI and MINT (Malaysian Institute for Nuclear Technology Research). The necessary dose for pasteurization of oil palm empty fruit bunch (EFB), which is a main cellulosic by-product of palm oil industry, was determined as 10 kGy. After pasteurization, the EFB substrate was inoculated with Pleurotus sajor-caju and fermented for 1 month. The digestibility and nutritional value of fermented products were evaluated as ruminant feeds and the mushroom can be produced as by-product. For the improvement of resources, radiation effects on polysaccharides such as chitosan, sodium alginate, carrageenan, cellulose, pectin have been investigated to induce the biological activities. These carbohydrates were easily degraded by irradiation and induced various kinds of biological activities. The anti-bacterial activity and elicitor activity of chitosan were induced by irradiation. The induction of phytoalexins was also observed by irradiated pectin but the higher elicitor activity for pisatin was obtained by chitosan than pectin. For the plant growth promotion, alginate derived from brown marine algae, chitosan and ligno-cellulosic extracts show a strong activity. carrageenan derived from red marine algae can promote growth of rice and the highest effect was obtained with kappa carrageenan irradiated at 100 kGy. Furthermore, some radiation degraded polysaccharides suppressed the damage of environmental stress on plants. (author)

Utilization of polysaccharides by radiation processing

International Nuclear Information System (INIS)

Kume, Tamikazu

2000-01-01

Radiation treatment has been applied for improvement or pasteurization of agro-resources to recycle the resources and to reduce the pollution of environment. By using the radiation effect for pasteurization, upgrading of cellulosic wastes of oil palm to animal feeds and mushroom has been studied under the bilateral research cooperation between JAERI and MINT (Malaysian Institute for Nuclear Technology Research). The necessary dose for pasteurization of oil palm empty fruit bunch (EFB), which is a main cellulosic by-product of palm oil industry, was determined as 10 kGy. After pasteurization, the EFB substrate was inoculated with Pleurotus sajor-caju and fermented for 1 month. The digestibility and nutritional value of fermented products were evaluated as ruminant feeds and the mushroom can be produced as by-product. For the improvement of resources, radiation effects on polysaccharides such as chitosan, sodium alginate, carrageenan, cellulose, pectin have been investigated to induce the biological activities. These carbohydrates were easily degraded by irradiation and induced various kinds of biological activities. The anti-bacterial activity and elicitor activity of chitosan were induced by irradiation. The induction of phytoalexins was also observed by irradiated pectin but the higher elicitor activity for pisatin was obtained by chitosan than pectin. For the plant growth promotion, alginate derived from brown marine algae, chitosan and ligno-cellulosic extracts show a strong activity. carrageenan derived from red marine algae can promote growth of rice and the highest effect was obtained with kappa carrageenan irradiated at 100 kGy. Furthermore, some radiation degraded polysaccharides suppressed the damage of environmental stress on plants. (author)

Investigation of abrupt degradation of drain current caused by under-gate crack in AlGaN/GaN high electron mobility transistors during high temperature operation stress

Energy Technology Data Exchange (ETDEWEB)

Zeng, Chang; Liao, XueYang; Li, RuGuan; Wang, YuanSheng; Chen, Yiqiang, E-mail: yiqiang-chen@hotmail.com; Su, Wei; Liu, Yuan; Wang, Li Wei; Lai, Ping; Huang, Yun; En, YunFei [Science and Technology on Reliability Physics and Application of Electronic Component Laboratory, The 5th Electronics Research Institute of the Ministry of Industry and Information Technology, 510610 Guangzhou (China)

2015-09-28

In this paper, we investigate the degradation mode and mechanism of AlGaN/GaN based high electron mobility transistors (HEMTs) during high temperature operation (HTO) stress. It demonstrates that there was abrupt degradation mode of drain current during HTO stress. The abrupt degradation is ascribed to the formation of crack under the gate which was the result of the brittle fracture of epilayer based on failure analysis. The origin of the mechanical damage under the gate is further investigated and discussed based on top-down scanning electron microscope, cross section transmission electron microscope and energy dispersive x-ray spectroscopy analysis, and stress simulation. Based on the coupled analysis of the failure physical feature and stress simulation considering the coefficient of thermal expansion (CTE) mismatch in different materials in gate metals/semiconductor system, the mechanical damage under the gate is related to mechanical stress induced by CTE mismatch in Au/Ti/Mo/GaN system and stress concentration caused by the localized structural damage at the drain side of the gate edge. These results indicate that mechanical stress induced by CTE mismatch of materials inside the device plays great important role on the reliability of AlGaN/GaN HEMTs during HTO stress.

Influência do amido e carragena nas propriedades texturiais de surimi de tilápia (Oreochomis sp. Influence of starch and carrageenan on textural properties on tilapia (Oreochomis sp. surimi

Directory of Open Access Journals (Sweden)

Pedro Luiz Manique BARRETO

1999-05-01

Full Text Available Foram utilizadas carcaças residuais da filetagem industrial de tilápias (Oreochomis sp. na obtenção de carne de pescado separada mecanicamente (CPSM para elaboração de surimi. Amidos de diferentes fontes, como milho ceroso, milho ceroso modificado e mandioca, e o polissacarídeo carragena foram usados como ingredientes, e estudados seus efeitos no comportamento do gel de surimi. O surimi elaborado a partir de carcaças residuais da filetagem industrial, apresentou um rendimento final de 25% (peso/peso. A análise instrumental de textura apresentou um efeito fortalecedor, em relação à força de penetração dos amidos no gel de surimi, sendo esse efeito proporcional à viscosidade (r = 0,81, pFillet frames from industrial processing of tilapias (Oreochomis sp. was utilized to obtained minced meat for surimi. Starch from differents sources ( waxy maize starch, modified waxy maize starch and tapioca and the polysaccharide carrageenan was utilized like additives, and then studied their effects on surimi gel behaviour. Tilapia surimi showed a yield of 25% (weight/weight. The instrumental analysis of texture showed a strong effect of starch in relation to penetration force in surimi gel, these effect was proportional to starches viscosity (r = 0,81, p<0,05, studied by Brabender amylograph, by other hand, both starch and carrageenan showed a decresed in viscoelasticity of surimi gel (p<0,005.

Parameter Estimation of a Reliability Model of Demand-Caused and Standby-Related Failures of Safety Components Exposed to Degradation by Demand Stress and Ageing That Undergo Imperfect Maintenance

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S. Martorell

2017-01-01

Full Text Available One can find many reliability, availability, and maintainability (RAM models proposed in the literature. However, such models become more complex day after day, as there is an attempt to capture equipment performance in a more realistic way, such as, explicitly addressing the effect of component ageing and degradation, surveillance activities, and corrective and preventive maintenance policies. Then, there is a need to fit the best model to real data by estimating the model parameters using an appropriate tool. This problem is not easy to solve in some cases since the number of parameters is large and the available data is scarce. This paper considers two main failure models commonly adopted to represent the probability of failure on demand (PFD of safety equipment: (1 by demand-caused and (2 standby-related failures. It proposes a maximum likelihood estimation (MLE approach for parameter estimation of a reliability model of demand-caused and standby-related failures of safety components exposed to degradation by demand stress and ageing that undergo imperfect maintenance. The case study considers real failure, test, and maintenance data for a typical motor-operated valve in a nuclear power plant. The results of the parameters estimation and the adoption of the best model are discussed.

Combining an Electrothermal and Impedance Aging Model to Investigate Thermal Degradation Caused by Fast Charging

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Joris de Hoog

2018-03-01

Full Text Available Fast charging is an exciting topic in the field of electric and hybrid electric vehicles (EVs/HEVs. In order to achieve faster charging times, fast-charging applications involve high-current profiles which can lead to high cell temperature increase, and in some cases thermal runaways. There has been some research on the impact caused by fast-charging profiles. This research is mostly focused on the electrical, thermal and aging aspects of the cell individually, but these factors are never treated together. In this paper, the thermal progression of the lithium-ion battery under specific fast-charging profiles is investigated and modeled. The cell is a Lithium Nickel Manganese Cobalt Oxide/graphite-based cell (NMC rated at 20 Ah, and thermal images during fast-charging have been taken at four degradation states: 100%, 90%, 85%, and 80% State-of-Health (SoH. A semi-empirical resistance aging model is developed using gathered data from extensive cycling and calendar aging tests, which is coupled to an electrothermal model. This novel combined model achieves good agreement with the measurements, with simulation results always within 2 °C of the measured values. This study presents a modeling methodology that is usable to predict the potential temperature distribution for lithium-ion batteries (LiBs during fast-charging profiles at different aging states, which would be of benefit for Battery Management Systems (BMS in future thermal strategies.

Anti-inflammatory effect of longan seed extract in carrageenan stimulated Sprague-Dawley rats

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Ching-Hsiao Lee

2016-08-01

Full Text Available Objective(s: Longan seeds have been used as a folk medicine in China. Longan seed extract (LSE is known for antioxidative, antiproliferative, hypoglycemic, and hypouremic effects. However, its anti-inflammatory effect has not been shown. Materials and Methods: In this study, Sprague-Dawley (SD rats were given LSE orally (vehicle, 10, and 30 mg/kg for 3 days to its test anti-inflammatory effect by injecting λ-carrageenan (CARR in the right hind paw or lipopolysaccharide (LPS, IP. For the positive control, animals were given aspirin (20 mg/kg orally and treated likewise. Serum or tissue samples from treated rats were collected after 3 hr of stimulation. Regarding the in vitro study, BV2 microglial cells were stimulated with LPS in the presence of LSE or normal saline for 10 min or 24 hr for Western blot and ELISA assay, respectively. Results: LSE reduced CARR-induced edema in the experimental animals. LSE also reduced LPS/CARR-induced nitric oxide (NO, interleukin-1β (IL1β, IL6, and COX2 productions. These inflammatory factors were also reduced dose dependently by LSE in LPS-stimulated BV2 cells. Furthermore, Western blot analysis revealed that LSE inhibited LPS activated c-Jun NH2-terminal protein kinase (JNK, extracellular signal-regulated kinases (ERKs, and p38 MAP kinases signaling pathways, caspase-3, inducible NO synthase, and COX2 expressions. Conclusion: LSE pretreatment suppressed CARR- and LPS-induced inflammations and these effects might be through the inhibition of MAP kinases signaling pathways and inflammatory factors.

Therapeutic effects of Qian-Yu decoction and its three extracts on carrageenan-induced chronic prostatitis/chronic pelvic pain syndrome in rats.

Science.gov (United States)

Zhang, Keda; Zeng, Xiaobin; Chen, Yonggang; Zhao, Rong; Wang, Hui; Wu, Jinhu

2017-01-25

Qian-Yu decoction (QYD) is a traditional Chinese medicinal recipe composed of Radix astragali (Astragalus membranaceus (Fisch.) Bunge var. mongholicus (Bunge) P.K. Hsiao, Fabaceae ), Herba epimedii (Epimedium brevicornum Maxim., Berberidaceae), Herba leonuri (Leonurus japonicus Houtt., Lamiaceae), Cortex phellodendri (Phellodendron chinense Schneid., Rutaceae) and Radix achyranthis bidentatae (Achyranthes bidentata Bl., Amaranthaceae). This study aimed to evaluate the therapeutic activity of QYD against carrageenan-induced chronic prostatic/chronic pelvic pain syndrome (CP/CPPS) in rats and further elucidate its effective components. Three types of components, total polysaccharides, total flavonoids and total saponins were separately extracted from QYD. Carrageenan-induced CP/CPPS rats were intragastrically administered with lyophilized product of QYD, individual extracts and all the combined forms of extracts for three weeks. Prostatic index (PI) was determined and histopathological analysis was performed. The levels of tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), cyclooxygenase-2 (COX-2) and prostaglandin E2 (PEG2) in rat prostate tissues were measured using ELISA. The production of inducible nitric oxide synthase (iNOS) was evaluated by an enzymatic activity assay, and the release of nitric oxide (NO) was determined by a nitrate/nitrite assay. Treatment with QYD significantly ameliorated the histological changes of CP/CPPS rats and reduced the PI by 44.3%, with a marked downregulation of TNF-α (42.8% reduction), IL-1β (45.3%), COX-2 (36.6%), PGE2 (44.2%), iNOS (54.1%) and NO (46.0%). Each of three extracts attenuated the symptom of CP/CPPS, but much more weakly than QYD. The combined administration of three extracts showed efficacy comparable to that of QYD while better than that of any combination of two extracts. A principal component analysis of the six inflammatory mediators as variables indicated that the effects of TS on CP

Soil-ecological risks for soil degradation estimation

Science.gov (United States)

Trifonova, Tatiana; Shirkin, Leonid; Kust, German; Andreeva, Olga

2016-04-01

Soil degradation includes the processes of soil properties and quality worsening, primarily from the point of view of their productivity and decrease of ecosystem services quality. Complete soil cover destruction and/or functioning termination of soil forms of organic life are considered as extreme stages of soil degradation, and for the fragile ecosystems they are normally considered in the network of their desertification, land degradation and droughts /DLDD/ concept. Block-model of ecotoxic effects, generating soil and ecosystem degradation, has been developed as a result of the long-term field and laboratory research of sod-podzol soils, contaminated with waste, containing heavy metals. The model highlights soil degradation mechanisms, caused by direct and indirect impact of ecotoxicants on "phytocenosis- soil" system and their combination, frequently causing synergistic effect. The sequence of occurring changes here can be formalized as a theory of change (succession of interrelated events). Several stages are distinguished here - from heavy metals leaching (releasing) in waste and their migration downward the soil profile to phytoproductivity decrease and certain phytocenosis composition changes. Phytoproductivity decrease leads to the reduction of cellulose content introduced into the soil. The described feedback mechanism acts as a factor of sod-podzolic soil self-purification and stability. It has been shown, that using phytomass productivity index, integrally reflecting the worsening of soil properties complex, it is possible to solve the problems dealing with the dose-reflecting reactions creation and determination of critical levels of load for phytocenosis and corresponding soil-ecological risks. Soil-ecological risk in "phytocenosis- soil" system means probable negative changes and the loss of some ecosystem functions during the transformation process of dead organic substance energy for the new biomass composition. Soil-ecological risks estimation is

Applying a dryland degradation framework for rangelands: the case of Mongolia.

Science.gov (United States)

Jamsranjav, C; Reid, R S; Fernández-Giménez, M E; Tsevlee, A; Yadamsuren, B; Heiner, M

2018-04-01

Livestock-caused rangeland degradation remains a major policy concern globally and the subject of widespread scientific study. This concern persists in part because it is difficult to isolate the effects of livestock from climate and other factors that influence ecosystem conditions. Further, degradation studies seldom use multiple plant and soil indicators linked to a clear definition of and ecologically grounded framework for degradation assessment that distinguishes different levels of degradation. Here, we integrate two globally applicable rangeland degradation frameworks and apply them to a broad-scale empirical data set for the country of Mongolia. We compare our assessment results with two other recent national rangeland degradation assessments in Mongolia to gauge consistency of findings across assessments and evaluate the utility of our framework. We measured livestock-use impacts across Mongolia's major ecological zones: mountain and forest steppe, eastern steppe, steppe, and desert steppe. At 143 sites in 36 counties, we measured livestock-use and degradation indicators at increasing distances from livestock corrals in winter-grazed pastures. At each site, we measured multiple indicators linked to our degradation framework, including plant cover, standing biomass, palatability, species richness, forage quality, vegetation gaps, and soil surface characteristics. Livestock use had no effect on soils, plant species richness, or standing crop biomass in any ecological zone, but subtly affected plant cover and palatable plant abundance. Livestock effects were strongest in the steppe zone, moderate in the desert steppe, and limited in the mountain/forest and eastern steppes. Our results aligned closely with those of two other recent country-wide assessments, suggesting that our framework may have widespread application. All three assessments found that very severe and irreversible degradation is rare in Mongolia (1-18% of land area), with most rangelands

A Markov chain model for CANDU feeder pipe degradation

International Nuclear Information System (INIS)

Datla, S.; Dinnie, K.; Usmani, A.; Yuan, X.-X.

2008-01-01

There is need for risk based approach to manage feeder pipe degradation to ensure safe operation by minimizing the nuclear safety risk. The current lack of understanding of some fundamental degradation mechanisms will result in uncertainty in predicting the rupture frequency. There are still concerns caused by uncertainties in the inspection techniques and engineering evaluations which should be addressed in the current procedures. A probabilistic approach is therefore useful in quantifying the risk and also it provides a tool for risk based decision making. This paper discusses the application of Markov chain model for feeder pipes in order to predict and manage the risks associated with the existing and future aging-related feeder degradation mechanisms. The major challenge in the approach is the lack of service data in characterizing the transition probabilities of the Markov model. The paper also discusses various approaches in estimating plant specific degradation rates. (author)

Degradation of Polypropylene Membranes Applied in Membrane Distillation Crystallizer

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Marek Gryta

2016-03-01

Full Text Available The studies on the resistance to degradation of capillary polypropylene membranes assembled in a membrane crystallizer were performed. The supersaturation state of salt was achieved by evaporation of water from the NaCl saturated solutions using membrane distillation process. A high feed temperature (363 K was used in order to enhance the degradation effects and to shorten the test times. Salt crystallization was carried out by the application of batch or fluidized bed crystallizer. A significant membrane scaling was observed regardless of the method of realized crystallization. The SEM-EDS, DSC, and FTIR methods were used for investigations of polypropylene degradation. The salt crystallization onto the membrane surface accelerated polypropylene degradation. Due to a polymer degradation, the presence of carbonyl groups on the membranes’ surface was identified. Besides the changes in the chemical structure a significant mechanical damage of the membranes, mainly caused by the internal scaling, was also found. As a result, the membranes were severely damaged after 150 h of process operation. A high level of salt rejection was maintained despite damage to the external membrane surface.

Anti-inflammatory Effect of Sodium Valproate on Carrageenan-Induced Paw Edema in Male Rat

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mj Khoshnood

2008-12-01

Full Text Available ABESTRACT: Introduction & objective: Inflammation is a body defensive response to the endogenous and exogenous stimulators such as chemical, radiation, trauma and invasive microorganism, which result pain and tissue necrosis. There are many natural and synthetic drugs for treatment of inflammation and lot of them are under investigation. Sodium valporate is an antiepileptic drug used particularly in the treatment of primary generalized seizure notably absence, myocolonic seizure, acute manic phase of bipolar disorder and prophylaxis of migraine. The previous observations showed sodium valporate increases level of gamma amino butyric acid (GABA in the central and peripheral nervous system. In acute inflammation, GABA showed a significant attenuation of paw edema and nociception. The aim of this study was evaluation of anti-inflammatory effect of sodium valporate. Materials & Methods: In order to evaluated the anti-inflammatory and antiexudative of sodium valporate doses of 200,400 and 600 mg/kg were investigated on rat paw edema that induced by carrageenan. In addition, the plasma leakage in the inflamed tissue was evaluated by application of trypan blue as intravenous injection. Dexamethason was used as positive control. Results: Results showed sodium valporate doses of 400 and 600 mg/kg decreased inflammatory and exudative effect as compared to control group. Conclusion: Although the anti-inflammatory mechanisms of this drug were not evident but we can say sodium valporate in addition to already proved effects has anti-inflammatory effect.

Degradation of gas-liquid gliding arc discharge on Acid Orange II

International Nuclear Information System (INIS)

Yan, J.H.; Liu, Y.N.; Bo, Zh.; Li, X.D.; Cen, K.F.

2008-01-01

The effects of pH value, initial concentration of dye solution and temperature on the degradation efficiency of Acid Orange II (AO7) using gas-liquid gliding arc discharge were investigated. The influences of pH value and temperature on degradation efficiency were not apparent. Increasing initial solution concentration caused the decrease of degradation rate and the increase of absolute degradation quantity. Considering energy efficiency and absolute degradation quantity, the gas-liquid gliding arc discharge is fit for treating high concentration organic wastewater. A possible mineralization pathway was proposed through the analysis of intermediate products detected by gas chromatograph coupled with mass spectrophotometer (GC-MS) and ion chromatograph (IC). Hydroxyl radicals reacted with the azo linkage-bearing carbon of a hydroxy-substituted ring, leading to the cleavage of -C-N- and degradation of AO7. The solution biodegradability was significantly improved (BOD 5 /COD from 0.02 to 0.43). The toxicity of intermediate products was lower than that of the initial Acid Orange II

Quantitative diagnosis and prognosis framework for concrete degradation due to alkali-silica reaction

Science.gov (United States)

Mahadevan, Sankaran; Neal, Kyle; Nath, Paromita; Bao, Yanqing; Cai, Guowei; Orme, Peter; Adams, Douglas; Agarwal, Vivek

2017-02-01

This research is seeking to develop a probabilistic framework for health diagnosis and prognosis of aging concrete structures in nuclear power plants that are subjected to physical, chemical, environment, and mechanical degradation. The proposed framework consists of four elements: monitoring, data analytics, uncertainty quantification, and prognosis. The current work focuses on degradation caused by ASR (alkali-silica reaction). Controlled concrete specimens with reactive aggregate are prepared to develop accelerated ASR degradation. Different monitoring techniques — infrared thermography, digital image correlation (DIC), mechanical deformation measurements, nonlinear impact resonance acoustic spectroscopy (NIRAS), and vibro-acoustic modulation (VAM) — are studied for ASR diagnosis of the specimens. Both DIC and mechanical measurements record the specimen deformation caused by ASR gel expansion. Thermography is used to compare the thermal response of pristine and damaged concrete specimens and generate a 2-D map of the damage (i.e., ASR gel and cracked area), thus facilitating localization and quantification of damage. NIRAS and VAM are two separate vibration-based techniques that detect nonlinear changes in dynamic properties caused by the damage. The diagnosis results from multiple techniques are then fused using a Bayesian network, which also helps to quantify the uncertainty in the diagnosis. Prognosis of ASR degradation is then performed based on the current state of degradation obtained from diagnosis, by using a coupled thermo-hydro-mechanical-chemical (THMC) model for ASR degradation. This comprehensive approach of monitoring, data analytics, and uncertainty-quantified diagnosis and prognosis will facilitate the development of a quantitative, risk informed framework that will support continuous assessment and risk management of structural health and performance.

Elucidation of release characteristics of highly soluble drug trimetazidine hydrochloride from chitosan-carrageenan matrix tablets.

Science.gov (United States)

Li, Liang; Wang, Linlin; Shao, Yang; Tian, Ye; Li, Conghao; Li, Ying; Mao, Shirui

2013-08-01

The aim of this study was to better understand the underlying drug release characteristics from matrix tablets based on the combination of chitosan (CS) and different types of carrageenans [kappa (κ)-CG, iota (ι)-CG, and lambda (λ)-CG]. Highly soluble trimetazidine hydrochloride (TH) was used as a model drug. First, characteristics of drug release from different formulations were investigated, and then in situ complexation capacity of CG with TH and CS was studied by differential scanning calorimetry and Fourier transform infrared spectroscopy. Erosion and swelling of matrix were also characterized to better understand the drug-release mechanisms. Effects of pH and ionic strength on drug release were also studied. It was found that not only ι-CG and λ-CG could reduce the burst release of TH by the effect of TH-CG interaction, CS-ι-CG- and CS-λ-CG-based polyelectrolyte film could further modify the controlled-release behavior, but not CS-κ-CG. High pH and high ionic strength resulted in faster drug release from CS-κ-CG- and CS-ι-CG-based matrix, but drug release from CS-λ-CG-based matrix was less sensitive to pH and ionic strength. In conclusion, CS-λ-CG-based matrix tablets are quite promising as controlled-release drug carrier based on multiple mechanisms. Copyright © 2013 Wiley Periodicals, Inc.

Enhanced mitochondrial degradation of yeast cytochrome c with amphipathic structures.

Science.gov (United States)

Chen, Xi; Moerschell, Richard P; Pearce, David A; Ramanan, Durga D; Sherman, Fred

2005-02-01

The dispensable N-terminus of iso-1-cytochrome c (iso-1) in the yeast Saccharomyces cerevisiae was replaced by 11 different amphipathic structures. Rapid degradation of the corresponding iso-1 occurred, with the degree of degradation increasing with the amphipathic moments; and this amphipathic-dependent degradation was designated ADD. ADD occurred with the holo-forms in the mitochondria but not as the apo-forms in the cytosol. The extreme mutant type degraded with a half-life of approximately 12 min, whereas the normal iso-1 was stable over hours. ADD was influenced by the rho+/rho- state and by numerous chromosomal genes. Most importantly, ADD appeared to be specifically suppressed to various extents by deletions of any of the YME1, AFG3, or RCA1 genes encoding membrane-associated mitochondrial proteases, probably because the amphipathic structures caused a stronger association with the mitochondrial inner membrane and its associated proteases. The use of ADD assisted in the differentiation of substrates of different mitochondrial degradation pathways.

Structural insight into molecular mechanism of poly(ethylene terephthalate) degradation.

Science.gov (United States)

Joo, Seongjoon; Cho, In Jin; Seo, Hogyun; Son, Hyeoncheol Francis; Sagong, Hye-Young; Shin, Tae Joo; Choi, So Young; Lee, Sang Yup; Kim, Kyung-Jin

2018-01-26

Plastics, including poly(ethylene terephthalate) (PET), possess many desirable characteristics and thus are widely used in daily life. However, non-biodegradability, once thought to be an advantage offered by plastics, is causing major environmental problem. Recently, a PET-degrading bacterium, Ideonella sakaiensis, was identified and suggested for possible use in degradation and/or recycling of PET. However, the molecular mechanism of PET degradation is not known. Here we report the crystal structure of I. sakaiensis PETase (IsPETase) at 1.5 Å resolution. IsPETase has a Ser-His-Asp catalytic triad at its active site and contains an optimal substrate binding site to accommodate four monohydroxyethyl terephthalate (MHET) moieties of PET. Based on structural and site-directed mutagenesis experiments, the detailed process of PET degradation into MHET, terephthalic acid, and ethylene glycol is suggested. Moreover, other PETase candidates potentially having high PET-degrading activities are suggested based on phylogenetic tree analysis of 69 PETase-like proteins.

Characterization of ZnO-degraded varistors used in high-tension devices

International Nuclear Information System (INIS)

Ramirez, M.A.; Simoes, A.Z.; Marquez, M.A.; Maniette, Y.; Cavalheiro, A.A; Varela, J.A.

2007-01-01

The effects of the degradation process on the structural, microstructural and electrical properties of ZnO-based varistors were analyzed. Rietveld refinement showed that the BiO 2-x phase is affected by the degradation process. Besides the changes in the spinel phase, the degradation process also affects the lattice microstrain in the ZnO phase. Scanning electron microscopy analysis showed electrode-melting failure, while wavelength dispersive X-ray spectroscopy qualitative analysis showed deficiency of oxygen species at the grain boundaries in the degraded samples. Atomic force microscopy using electrostatic mode force illustrated a decrease in the charge density at the grain boundaries of the degraded sample. Transmission electron microscopy showed submicrometric spinel grains embedded in a ZnO matrix, but their average grain size is smaller in the degraded sample than in the standard one. Long pulses appeared to be more harmful for the varistors' properties than short ones, causing higher leakage current values. The electrical characteristics of the degraded sample are partially restored after heat treatment in an oxygen-rich atmosphere

GIS-based evaluation and spatial distribution characteristics of land degradation in Bijiang watershed.

Science.gov (United States)

Zhao, Xiaoqing; Dai, Jinhua; Wang, Jianping

2013-01-01

Land degradation is one of the significant issues the human beings are confronted with, which has become a bottleneck of restricting the sustainable development of the regional society and economy. In order to ascertain the root causes contributed to the land degradation and characteristics of land degradation, Bijiang watershed, the most important Lead-Zinc mine area of Lanping county of Yunnan Province, was selected as the study area. One evaluation index system for land degradation that consists of 5 single factors(water-soil erosion intensity, geological disaster risk, cultivation intensity of arable land, pollution of heavy metals in soil and biodiversity deterioration) was established and 13 indicators were chosen, and the entropy method was adopted to assign weights to each single factor. By using the tools of Geographic Information System (GIS), the land degradation degree was evaluated and one spatial distribution map for land degradation was accomplished. In this study, the land of the whole watershed was divided into 4 types, including extremely-severe degradation area, severely-degraded area, moderately-degraded area and slightly-degraded area, and some solutions for ecological restoration and rehabilitation were also put forward in this study. The study results indicated that: (1) Water-soil erosion intension and pollution of heavy metals in soil have made greater contribution to the comprehensive land degradation in Bijiang watershed; (2) There is an apparent difference regarding land degradation degree in Bijiang watershed. The moderately-degraded area accounts for the most part in the region, which covers 79.66% of the whole watershed. The severely-degraded area accounts for 15.98% and the slightly-degraded regions and extremely severe degradation area accounts for 1.08% and 3.28% respectively; (3) There is an evident regularity of spatial distribution in land degradation in Bijiang watershed. The moderately-degraded areas mainly distribute in the

Development of degradation prediction technology for rotating machines

International Nuclear Information System (INIS)

Osaki, Kenji; Watanabe, Yukio; Kitajima, Yasumi; Hattori, Hitoshi; Uhara, Yoshihiko; Miyoshi, Toshiaki; O'shima, Eiji

1999-01-01

In order to rationalize facility maintenance management, it is desirable to develop degradation prediction technologies that reduce the workload for example of replacing worn bearings of rotating machines. For this purpose, we are developing a system that performs degradation prediction respecting casing deformation, curvature and crack of shaft, bearing sleeve corrosion, and bearing wear for primary loop recirculation (PLR) pumps, which are important equipment in BWR plants, and for sea water pumps whose bearings are replaced frequently. By means of a physical model of degradation that takes into account various degradation phenomena, this system performs life estimation, taking into consideration the distribution of the vibration characteristic caused by the differences in assembling processes and the distribution of the degradation characteristic. The design of the degradation prediction system was examined and a part of the analysis method was developed. The bearing characteristic analysis with consideration to surface roughness was performed and the vibration response analysis evaluated the effects of factors influencing vibration characteristics of pump, such as bearing misalignment, on bearing forces. The component test of an upper bearing of 1/2 scale PLR pump motor was carried out, and the bearing wear characteristic was clarified. The research was carried out by the Japan Power Engineering and Inspection Corporation (JAPEIC) which was entrusted by the Ministry of International Trade and Industry (MITI). (author)

Steam generator degradation: Current mitigation strategies for controlling corrosion

International Nuclear Information System (INIS)

Millett, P.

1997-01-01

Steam Generator degradation has caused substantial losses of power generation, resulted in large repair and maintenance costs, and contributed to significant personnel radiation exposures in Pressurized Water Reactors (PWRs) operating throughout the world. EPRI has just published the revised Steam Generator Reference Book, which reviews all of the major forms of SG degradation. This paper discusses the types of SG degradation that have been experienced with emphasis on the mitigation strategies that have been developed and implemented in the field. SG degradation is presented from a world wide perspective as all countries operating PWRs have been effected to one degree or another. The paper is written from a US. perspective where the utility industry is currently undergoing tremendous change as a result of deregulation of the electricity marketplace. Competitive pressures are causing utilities to strive to reduce Operations and Maintenance (O ampersand M) and capital costs. SG corrosion is a major contributor to the O ampersand M costs of PWR plants, and therefore US utilities are evaluating and implementing the most cost effective solutions to their corrosion problems. Mitigation strategies developed over the past few years reflect a trend towards plant specific solutions to SG corrosion problems. Since SG degradation is in most cases an economic problem and not a safety problem, utilities can focus their mitigation strategies on their unique financial situation. Accordingly, the focus of R ampersand D has shifted from the development of more expensive, prescriptive solutions (e.g. reduced impurity limits) to corrosion problems to providing the utilities with a number of cost effective mitigation options (e.g. molar ratio control, boric acid treatment)

Degradation of morpholine by Mycobacterium sp. isolated from ...

African Journals Online (AJOL)

The biodegradation of morpholine has attracted much interest because morpholine causes environmental pollution. Ten species belonging to nine genera were tested for their abilities to degrade morpholine in mineral salts medium containing morpholine (1 g/l). Mycobacterium sp. isolated from polluted water sample ...

Age-related degradation of boiling water reactor vessel internals

International Nuclear Information System (INIS)

Ware, A.G.; Shah, V.N.

1992-01-01

Researchers at the Idaho National Engineering Laboratory performed an assessment of the aging of the reactor internals in boiling water reactors (BWRs), and identified the unresolved technical issues related to the degradation of these components. The overall life-limiting mechanism is intergranular stress corrosion cracking (IGSCC). Irradiation-assisted stress corrosion cracking, fatigue, and thermal aging embrittlement are other potential degradation mechanisms. Several failures in BWR internals have been caused by a combination of factors such as environment, high residual or preload stresses, and flow-induced vibration. The ASME Code Section XI in-service inspection requirements are insufficient for detecting aging-related degradation at many locations in reactor internals. Many of the potential locations for IGSCC or fatigue are not accessible for inspection. (orig.)

Swift heavy ion irradiation induced electrical degradation in deca-nanometer MOSFETs

Energy Technology Data Exchange (ETDEWEB)

Ma, Yao; Yang, Zhimei; Gong, Min [Key Laboratory for Microelectronics, College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Gao, Bo; Li, Yun; Lin, Wei; Li, Jinbo; Xia, Zhuohui [Key Laboratory for Microelectronics, College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China)

2016-09-15

In this work, degradation of the electrical characteristics of 65 nm nMOSFETs under swift heavy ion irradiation is investigated. It was found that a heavy ion can generate a localized region of physical damage (ion latent track) in the gate oxide. This is the likely cause for the increased gate leakage current and soft breakdown (SBD) then hard breakdown (HBD) of the gate oxide. Except in the case of HBD, the devices retain their functionality but with degraded transconductance. The degraded gate oxide exhibits early breakdown behavior compatible with the model of defect generation and percolation path formation in the percolation model.

Degradation of oxcarbazepine by UV-activated persulfate oxidation: kinetics, mechanisms, and pathways.

Science.gov (United States)

Bu, Lingjun; Zhou, Shiqing; Shi, Zhou; Deng, Lin; Li, Guangchao; Yi, Qihang; Gao, Naiyun

2016-02-01

The degradation kinetics and mechanism of the antiepileptic drug oxcarbazepine (OXC) by UV-activated persulfate oxidation were investigated in this study. Results showed that UV/persulfate (UV/PS) process appeared to be more effective in degrading OXC than UV or PS alone. The OXC degradation exhibited a pseudo-first order kinetics pattern and the degradation rate constants (k obs) were affected by initial OXC concentration, PS dosage, initial pH, and humic acid concentration to different degrees. It was found that low initial OXC concentration, high persulfate dosage, and initial pH enhanced the OXC degradation. Additionally, the presence of humic acid in the solution could greatly inhibit the degradation of OXC. Moreover, hydroxyl radical (OH•) and sulfate radical (SO4 (-)••) were identified to be responsible for OXC degradation and SO4 (-)• made the predominant contribution in this study. Finally, major intermediate products were identified and a preliminary degradation pathway was proposed. Results demonstrated that UV/PS system is a potential technology to control the water pollution caused by emerging contaminants such as OXC.

Degradation of the photoluminescence of porous silicon caused by 60Co γ radiation

International Nuclear Information System (INIS)

Astrova, E.V.; Emtsev, V.V.; Lebedev, A.A.

1995-01-01

Two series of experiments were carried out. In the first, as-grown porous silicon was bombarded with 60 Co γ radiation to a dose ∼ 10 20 cm -2 . The photoluminescence intensity fell off by a factor ∼ 50 as a result, although the peak of the band underwent essentially no shift. In the second series, single-crystal silicon was bombarded to the same dose, and then porous silicon was fabricated on it. The intensity and spectra of these samples were the same as usual. Possible degradation mechanisms are discussed. 12 refs., 2 figs

Pathway and rate-limiting step of glyphosate degradation by Aspergillus oryzae A-F02.

Science.gov (United States)

Fu, Gui-Ming; Chen, Yan; Li, Ru-Yi; Yuan, Xiao-Qiang; Liu, Cheng-Mei; Li, Bin; Wan, Yin

2017-09-14

Aspergillus oryzae A-F02, a glyphosate-degrading fungus, was isolated from an aeration tank in a pesticide factory. The pathway and rate-limiting step of glyphosate (GP) degradation were investigated through metabolite analysis. GP, aminomethylphosphonic acid (AMPA), and methylamine were detected in the fermentation liquid of A. oryzae A-F02, whereas sarcosine and glycine were not. The pathway of GP degradation in A. oryzae A-F02 was revealed: GP was first degraded into AMPA, which was then degraded into methylamine. Finally, methylamine was further degraded into other products. Investigating the effects of the exogenous addition of substrates and metabolites showed that the degradation of GP to AMPA is the rate-limiting step of GP degradation by A. oryzae A-F02. In addition, the accumulation of AMPA and methylamine did not cause feedback inhibition in GP degradation. Results showed that degrading GP to AMPA was a crucial step in the degradation of GP, which determines the degradation rate of GP by A. oryzae A-F02.

Temperature Induced Degradation of Nb Ti/Cu Composite Superconductors

CERN Document Server

Scheuerlein, C; Senatore, C; Di Michiel, M; Thilly, L; Gerardin, A; Reluner, B; Oberli, L; Willering, G; Bottura, L

2009-01-01

The degradation mechanisms of state-of-the-art Nb-Ti/Cu superconductors are described, based on in-situ synchrotron X-ray diffraction measurements during heat treatment. A quantitative description of the Nb-Ti/Cu degradation in terms of critical current density, Cu stabiliser resistivity and mechanical composite strength is presented. In an applied magnetic field a significant critical current degradation is already observed after a 5-minute 400 °C heat treatment, due to variations of a-Ti precipitate size and distribution within the Nb-Ti alloy filaments. A strong degradation of the strand mechanical properties is observed after several minutes heating above 550 °C, which is also the temperature at which the formation of Cu Ti intermetallic phases is detected. Several minutes heating at 250 °C are sufficient to increase the RRR of the strongly cold work strands inside a Rutherford type cable from about 80 to about 240. Heating for several minutes at 400 °C does not cause a significant conductor degradati...

Biological degradation of chernozems under irrigation

Directory of Open Access Journals (Sweden)

Oksana Naydyonova

2014-12-01

Full Text Available We studied the changes in the state of microbial cenosis of Ukraine’s chernozems under irrigation. Considerable part of Ukraine’s chernozems is located in the areas where humidification is insufficient and unstable. Irrigation is a soil-reclamation measure for chernozems of Ukrainian Forest-steppe and Steppe which enables getting the assured yield, especially vegetable and fodder crops. At the same time, irrigation is a powerful anthropogenic factor that affects the soil, causes a significant transformation of many of its properties and regimes including biological ones. Often these changes are negative. The purpose of our investigation was to identify changes in the state of microbial cenoses of chernozem soils under irrigation which depend on such factors as the quality of irrigation water, the duration and intensity of irrigation, the initial properties of soil, the structure of crop rotation, usage of fertilizing systems and agroameliorative techniques. We identified direction and evaluated a degree of changes in biological properties of chernozems under influence of irrigation in different agro-irrigational and soil-climatic conditions. In the long-term stationary field experiments we identified the following biological indices of irrigated soils and their non-irrigated analogues: a number of microorganisms which belong to main ecological-trophic groups, activity of soil enzymes (dehydrogenase, invertase, phenol oxidase, soil phytotoxic activity, cellulose destroying capacity of soil, indices of oligotrophy and mineralization, summary biological index (SBI and index of biological degradation (BDI. Results of researches showed that irrigation unbalanced the soil ecosystem and stipulated the forming of microbial cenosis with new parameters. Long-term intensive irrigation of typical chernozem (Kharkiv Region with fresh water under condition of 4-fields vegetable crop rotation led to the degradation changes of its microbial cenosis such as

Land degradation and adoption of soil conservation technologies ...

African Journals Online (AJOL)

The study investigates the causes of land degradation, and adoption of soil conservation practices using a two-stage decision making process. The data for the study were collected with the aid of structured questionnaire and analyzed with descriptive analysis, difference regression equation and simultaneous probit model.

Change of mechanical properties of Norway Spruce wood due to degradation caused by fire retardants

Czech Academy of Sciences Publication Activity Database

Kloiber, Michal; Frankl, Jiří; Drdácký, Miloš; Kučerová, I.; Tippner, J.; Bryscejn, Jan

2010-01-01

Roč. 55, č. 4 (2010), s. 23-38 ISSN 1336-4561 Grant - others:GAČR(CZ) GA103/07/1091 Program:GA Institutional research plan: CEZ:AV0Z20710524 Keywords : wood degradation * fire retardant * mechanical properties * tensile strength * hardness Subject RIV: JN - Civil Engineering Impact factor: 0.284, year: 2010

Scenarios in tropical forest degradation: carbon stock trajectories for REDD+

Directory of Open Access Journals (Sweden)

Rafael B. de Andrade

2017-03-01

Full Text Available Abstract Background Human-caused disturbance to tropical rainforests—such as logging and fire—causes substantial losses of carbon stocks. This is a critical issue to be addressed in the context of policy discussions to implement REDD+. This work reviews current scientific knowledge about the temporal dynamics of degradation-induced carbon emissions to describe common patterns of emissions from logging and fire across tropical forest regions. Using best available information, we: (i develop short-term emissions factors (per area for logging and fire degradation scenarios in tropical forests; and (ii describe the temporal pattern of degradation emissions and recovery trajectory post logging and fire disturbance. Results Average emissions from aboveground biomass were 19.9 MgC/ha for logging and 46.0 MgC/ha for fire disturbance, with an average period of study of 3.22 and 2.15 years post-disturbance, respectively. Longer-term studies of post-logging forest recovery suggest that biomass accumulates to pre-disturbance levels within a few decades. Very few studies exist on longer-term (>10 years effects of fire disturbance in tropical rainforests, and recovery patterns over time are unknown. Conclusions This review will aid in understanding whether degradation emissions are a substantial component of country-level emissions portfolios, or whether these emissions would be offset by forest recovery and regeneration.

Soil Resources Degradation and Conservation Techniques Adopted ...

African Journals Online (AJOL)

Soil degradation is increasingly regarded as a major constraint to food production in the tropics. This problem is primarily caused by soil erosion, which particularly damages the soil surfaces. It is therefore the objectives of this paper to study the types of erosion in Gusau area as well as its effects on selected soil properties ...

Synthesis of Polyvinyl Pirrolidone (PVC /Κ-Carrageenan Hydrogel Prepared by Gamma Radiation Processing As a Function of Dose and PVP Concentration

Directory of Open Access Journals (Sweden)

Erizal Erizal

2013-05-01

Full Text Available The aim of this research is to prepare a biomaterial to be used in health care. A series of hydrogels based on polyvinyl pyrrolidone (PVP/κ-Carrageenan (KC has been prepared by radiation technique. PVP (5-15% were mixed with ΚC (2% and irradiated by gamma rays at the doses from 25 kGy to 35 kGy (dose rate 7 kGy/h at room temperature. The chemical change of hydrogels was characterized using Fourier Transform infra Red (FTIR. Gel fraction, water absorption and water evaporation were determined gravimetrically. Tensile strength and elongation at break was measured using Instron meter. It was found that with the increase irradiation dose and PVP concentration, the gel fraction and tensile strength of hydrogels increase. In contrast the elongation at break and water absorption of hydrogels decrease. The hydrogel of PVP/KC hydrogel produced by gamma radiation can be considered for wound dressings.

Investigation of the degradation of LSM-YSZ SOFC cathode by electrochemical impedance spectroscopy

DEFF Research Database (Denmark)

Torres da Silva, Iris Maura

The aim of this PhD study was to investigate degradation of the LSM-YSZ cathode of anode supported Ni-YSZ/YSZ/LSM-YSZ solid oxide fuel cells. The chosen cathode materials LSM25 and 8YSZ were investigated for their compatibility and stability, to confirm that expansion/contraction or decreasing......, at different operating conditions. An equivalent circuit was developed for the symmetrical cell, describing the processes taking place at the LSM-YSZ cathode. This equivalent circuit was applied in degradation studies, where the processes affected by degradation over time could be pinpointed. Furthermore......, it was discovered that impurities in air cause significant degradation of the cathode. Humidity was found to increase the degradation rate, but other impurities might also be present and increasing degradation. Then the anode supported Ni-YSZ/YSZ/LSM-YSZ single cells were prepared and tested. It was found...

Polyaniline - Carrageenan - Polyvinyl Alcohol Composite Material Synthesized Via Interfacial Polymerization, its Morphological Characteristics and Enhanced Solubility in Water

Science.gov (United States)

Montalbo, R. C. K.; Marquez, M. C.

2017-09-01

In recent years, conducting polyaniline (PAni) has been a popular interest of research in the field of conducting polymers due to its relatively low cost, ease of production, good conductivity, and environmental stability. Many studies however, have focused on improving its short-comings such as its limited processability and solubility in common solvents. In this study, PAni, soluble in water was produced via interfacial polymerization with chloroform as the organic solvent. Poly(vinyl alcohol) (PVA) and kappa(κ), iota(ι) and lambda(λ) - carrageenan (κCGN, ιCGN, λCGN) were added to the aqueous layer to stabilize PAni in the medium. FTIR and UV-Vis absorption spectra of the solutions as well as the fabricated film confirmed the existence of PAni emeraldine salt (PAni-ES). FTIR spectrum also confirmed the peaks corresponding to the interaction of PAni with the CGNs. Moreover, PVA-CGN played a very large role on the stability of the PAni nanofibers integrated on the PVA-CGN matrix. The morphologies of the products were further investigated using SEM and TEM. Polymer electrolyte for supercapacitor or an interfacial layer for organic solar cell is being targeted as potential application of the synthesized water soluble PAni.

Increased degradation rate of nitrososureas in media containing carbonate.

Science.gov (United States)

Seidegård, Janeric; Grönquist, Lena; Tuvesson, Helen; Gunnarsson, Per-Olov

2009-01-01

The stability of two nitrosoureas, tauromustine and lomustine, has been investigated in different media and buffers. All media tested, except Leibovitz's L-15 medium, significantly increased the degradation rate of the investigated nitrosoureas at pH 7.4. Sodium bicarbonate seems to be the cause of the observed increase of the degradation rate, since it provides the main buffering capacity of all the media except for Leibovitz's L-15 medium, which is based on phosphate buffer. Other ingredients in the media, such as amino acids, vitamins, and inorganic salts, or the ionic strength of a buffer, did not have any major effect on the degradation rate of the nitrosoureas. These results suggest that media containing carbonated buffer should be avoided when the anti-tumor effect of nitrosoureas is to be investigated in different cell cultures.

DEGRADATION OF CZECHOSLOVAK CREEP RESISTANT STEELS AFTER 50 YEARS OF SERVICE

Directory of Open Access Journals (Sweden)

Ladislav Horváth

2014-04-01

Full Text Available Thermally loaded assemblies in the energy and chemical industries require materials that provide the necessary functional characteristics, even after very long periods of operation. For the assessment of these materials are used expression grade of degradation in the basic meaning of the original English word grade = quality grade, Where the degradation is cumulative deterioration of quality (properties and thereby reduce the utility value. Knowledge of these mechanisms acting simultaneously allows determining the boundary conditions and more efficient utilization of used materials. Alternatively, it may give information to a qualified estimate of the causes of failure. Degradation starts its own production of semi-finished products (purity, structural homogeneity continues through technological factors of production (welding and the last part of degradation is during service of the parts (corrosion, hydrogen embrittlement, etc.. The aim of this article is at bases information obtained from fifty years of degraded materials to obtain information for more accurate reference catalogue. This catalogue can on bases information obtained from the microstructure and hardness estimate the state of degradation or possible time to rupture for the material.

Intrinsic immunogenicity of rapidly-degradable polymers evolves during degradation.

Science.gov (United States)

Andorko, James I; Hess, Krystina L; Pineault, Kevin G; Jewell, Christopher M

2016-03-01

Recent studies reveal many biomaterial vaccine carriers are able to activate immunostimulatory pathways, even in the absence of other immune signals. How the changing properties of polymers during biodegradation impact this intrinsic immunogenicity is not well studied, yet this information could contribute to rational design of degradable vaccine carriers that help direct immune response. We use degradable poly(beta-amino esters) (PBAEs) to explore intrinsic immunogenicity as a function of the degree of polymer degradation and polymer form (e.g., soluble, particles). PBAE particles condensed by electrostatic interaction to mimic a common vaccine approach strongly activate dendritic cells, drive antigen presentation, and enhance T cell proliferation in the presence of antigen. Polymer molecular weight strongly influences these effects, with maximum stimulation at short degradation times--corresponding to high molecular weight--and waning levels as degradation continues. In contrast, free polymer is immunologically inert. In mice, PBAE particles increase the numbers and activation state of cells in lymph nodes. Mechanistic studies reveal that this evolving immunogenicity occurs as the physicochemical properties and concentration of particles change during polymer degradation. This work confirms the immunological profile of degradable, synthetic polymers can evolve over time and creates an opportunity to leverage this feature in new vaccines. Degradable polymers are increasingly important in vaccination, but how the inherent immunogenicity of polymers changes during degradation is poorly understood. Using common rapidly-degradable vaccine carriers, we show that the activation of immune cells--even in the absence of other adjuvants--depends on polymer form (e.g., free, particulate) and the extent of degradation. These changing characteristics alter the physicochemical properties (e.g., charge, size, molecular weight) of polymer particles, driving changes in

Radiation-chemical degradation of traces of trichloroethylene and perchloroethylene in drinking water

International Nuclear Information System (INIS)

Gehringer, P.; Proksch, E.; Szinovatz, W.; Eschweiler, H.

1986-01-01

The degradation caused by gamma irradiation of traces of trichloroethylene and perchloroethylene in certain water samples has been investigated over a wide range of concentrations. In general, the degradation is the slower, the higher the concentration of organic and inorganic substances (especially of nitrates) dissolved in the respective water. For pollutant concentrations up to about 500 ppb and for drinking water with rather low nitrate content (some ppm) the degradation follows a first-order rate law. For higher concentrations of pollutants or/and nitrates a much more complex behaviour is observed. In general, perchloroethylene is degraded slower than trichloroethylene. During degradation, organic chlorine is converted quantitatively to chloride ions. Unfortunately, as a side reaction nitrate is partially reduced to nitrite. Except for that, first rough estimates resulted in costs which seem to render such a process economically quite attractive. (orig.) [de

Shear and elongational rheology of photo-oxidative degraded HDPE and LLDPE

Science.gov (United States)

Wagner, Manfred Hermann; Zheng, Wang; Wang, Peng; Talamante, Sebastián Ramos; Narimissa, Esmaeil

2017-05-01

The effect of photo-oxidative degradation of high-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE) was investigated by linear and non-linear rheological measurements. The linear-viscoelastic rheological measurements were performed at different temperatures, while the elongational viscosity was measured at 170°C and at different strain rates. The rheological data are indicative of structural changes caused by photo-oxidative degradation including formation of long-chain branches (LCB), cross-linking, and chain scission, and they revealed a cyclic and continuing competition between chain scission and LCB/gel formation. These findings are supported by additional FTIR measurements and direct measurements of the gel content of the degraded samples.

Effects of organic degradation products on the sorption of actinides

International Nuclear Information System (INIS)

Baston, G.M.N.; Berry, J.A.; Bond, K.A.; Brownsword, M.; Linklater, C.M.

1992-01-01

Previous work has shown that products from the chemical degradation of cellulosic matter can significantly reduce sorption of uranium(VI) and plutonium(IV) on geological materials. Uranium(IV) batch sorption experiments have now been performed to study the effect of organic degradation products in a reducing environment. Thorium(IV) sorption has also been studied since thorium is an important radioelement in its own right and has potential use as a simulant for other tetravalent actinides. Sorption onto London clay, Caithness flagstones and St. Bees sandstone was investigated. Experimental conditions were chosen to simulate both those expected close to cementitious repository (pH ∝ 11) and at the edge of the zone of migration of the alkaline plume (pH ∝ 8). Work was carried out with both authentic degradation products and with gluconate, acting as a well-characterized simulant for cellulosic degradation products. The results show that the presence of organic species can cause a reduction in sorption. This is especially so in the presence of a high concentration of gluconate ions, but the reduction is significantly less with authentic degradation products. (orig.)

Problems caused by dioxins and furans. Pt. 2. Controls and degradation methods; `I problemi causati da diossine e furani. Pt. 2. Metodi di contenimento e di degradazione

Energy Technology Data Exchange (ETDEWEB)

Gervasini, A.; Vezzoli, G.C.; Ragaini, V. [Milan Univ. (Italy). Dip. di Chimica Fisica ed Elettrochimica

1999-01-01

The environmental effects and the toxicity towards human health caused by polychlorodibenzodioxins and furans (PCDD/F) is related to the peculiar properties of the various isomers and to the geographic and climatic characteristics of the emission sources. The different methods and techniques of control and degradation introduced in the last years have to take into account the type and the location of the source. A survey of the principal methods of degradation of PCDD/F, thermal, chemical, photochemical, and catalytic decomposition, with their advantages and limits is presented. [Italiano] L`impatto che policlorodibenzodiossine e furani (PCDD/F) provocano sull`ambiente e sulla salute dell`uomo e` legato oltre che alle proprieta` peculiari dei vari congeneri alle caratteristiche geografiche e climatologiche del luogo in cui vengono emesse. Le metodologie di contenimento e le tecniche di degradazione messe a punto negli ultimi anni devono tenere in considerazione anche l`ubicazione e il tipo di sorgente dell`emissione. Viene fornita una panoramica sui principali metodi di degradazione di PCDD/F discutendo vantaggi e limiti delle varie tecniche: decomposizione termica, chimica, fotochimica e catalitica.

Thermal Efficiency Degradation Diagnosis Method Using Regression Model

International Nuclear Information System (INIS)

Jee, Chang Hyun; Heo, Gyun Young; Jang, Seok Won; Lee, In Cheol

2011-01-01

This paper proposes an idea for thermal efficiency degradation diagnosis in turbine cycles, which is based on turbine cycle simulation under abnormal conditions and a linear regression model. The correlation between the inputs for representing degradation conditions (normally unmeasured but intrinsic states) and the simulation outputs (normally measured but superficial states) was analyzed with the linear regression model. The regression models can inversely response an associated intrinsic state for a superficial state observed from a power plant. The diagnosis method proposed herein is classified into three processes, 1) simulations for degradation conditions to get measured states (referred as what-if method), 2) development of the linear model correlating intrinsic and superficial states, and 3) determination of an intrinsic state using the superficial states of current plant and the linear regression model (referred as inverse what-if method). The what-if method is to generate the outputs for the inputs including various root causes and/or boundary conditions whereas the inverse what-if method is the process of calculating the inverse matrix with the given superficial states, that is, component degradation modes. The method suggested in this paper was validated using the turbine cycle model for an operating power plant

Entanglement degradation in depolarizing light scattering

International Nuclear Information System (INIS)

Aiello, A.; Woerdman, J.P.

2005-01-01

Full text: In the classical regime, when a beam of light is scattered by a medium, it may emerge partially or completely depolarized depending on the optical properties of the medium. Correspondingly, in the quantum regime, when an entangled two-photon pair is scattered, the classical depolarization may result in an entanglement degradation. Here, relations between photon scattering, entanglement and multi-mode detection are investigated. We establish a general framework in which one- and two-photon elastic scattering processes can be discussed, and we focus on the study of the intrinsic entanglement degradation caused by a multi-mode detection. We show that any multi-mode scattered state cannot maximally violate the Bell-CHSH inequality because of the momentum spread. The results presented here have general validity and can be applied to both deterministic and random scattering processes. (author)

Determination of degradability of treated soybean meal and its ...

African Journals Online (AJOL)

STORAGESEVER

2009-01-05

Jan 5, 2009 ... caused a reduction in the dry matter and effective crude protein degradability compared with NTSBM. Electrophoretic patterns of ... Rapidly growing ruminants and lactating dairy cattle rely on both microbial protein ..... Proceedings of the Guelph Nutritional Conference on Feed. Manufacturers, pp. 35-43.

Carbon isotope effects associated with Fenton-like degradation of toluene: Potential for differentiation of abiotic and biotic degradation

International Nuclear Information System (INIS)

Ahad, Jason M.E.; Slater, Greg F.

2008-01-01

Hydrogen peroxide (H 2 O 2 )-mediated oxygenation to enhance subsurface aerobic biodegradation is a frequently employed remediation technique. However, it may be unclear whether observed organic contaminant mass loss is caused by biodegradation or chemical oxidation via hydroxyl radicals generated during catalyzed Fenton-like reactions. Compound-specific carbon isotope analysis has the potential to discriminate between these processes. Here we report laboratory experiments demonstrating no significant carbon isotope fractionation during Fenton-like hydroxyl radical oxidation of toluene. This implies that observation of significant isotopic fractionation of toluene at a site undergoing H 2 O 2 -mediated remediation would provide direct evidence of biodegradation. We applied this approach at a field site that had undergone 27 months of H 2 O 2 -mediated subsurface oxygenation. Despite substantial decreases (> 68%) in groundwater toluene concentrations carbon isotope signatures of toluene (δ 13 C tol ) showed no significant variation (mean = - 27.5 ±0.3 per mille, n = 13) over a range of concentrations from 11.1 to 669.0 mg L -1 . Given that aerobic degradation by ring attack has also been shown to result in no significant isotopic fractionation during degradation, at this site we were unable to discern the mechanism of degradation. However, such differentiation is possible at sites where aerobic degradation by methyl group attack results in significant isotopic fractionation

Chromatin degradation under the effect of differentiation inductors and γ-radiation on thymus lymphocytes in vitro

International Nuclear Information System (INIS)

Soldatenkov, V.A.; Sorokina, N.I.; Filippovich, I.V.

1985-01-01

Chemical inductors of differentiation were shown to cause chromatin degradation in thymus lymphocytes. This process was prevented by the protein synthesis inhibitors. The fragments formed after the effect of chemical differentiation inductors on thymocytes were fully identical to chromatin internucleosome degradation products formed in the exposed cells. Chromatin degradation under the effect of chemical differentiation inductors was most pronounced in a more radiosensitive thymocyte fraction

Novel Enzymes for Targeted Hydrolysis of Algal Cell Walls

DEFF Research Database (Denmark)

Schultz-Johansen, Mikkel

Seaweeds, also known as macroalgae, constitute a rich source of valuable biomolecules which have a potential industrial application in food and pharma products. The use of enzymes can optimize the extraction and separation of these molecules from the seaweed biomass, but most commercial enzymes...... are incapable of breaking the complex polysaccharides found in seaweed cell walls. Therefore, new enzymes are needed for degradation of seaweed biomass. Bacteria that colonize the surfaces of seaweed secrete enzymes that allow them to degrade and utilize seaweed polysaccharides as energy. In addition, sea...... degradation. In addition, three carrageenases were characterised; one as a GH16 κ-carrageenase whereas the other two belong to a new GH16 subfamily of enzymes that degrade furcellaran (κ/β-carrageenan). From metagenome sequence data three putative GH107 fucanases were identified and characterized...

Effect of Polylactic Acid-Degradable Film Mulch on Soil Temperature and Cotton Yield

Directory of Open Access Journals (Sweden)

ZHANG Ni

2016-03-01

Full Text Available Concern on biodegradable plastic film is increasing because of pollution problems caused by the plastic films currently used. The objective of this field experiment is to evaluate the effect of two thicknesses of polyactic acid-degradable film on soil temperature and cotton yield. The results showed that small holes appeared in the polyactic acid-degradable film at 17~22 d after it was installed. Burst period appeared about 60 d after installation. Splits were observed in the polyactic acid-degradable film at 130 d after installation. Soil temperatures rose slowly under polyactic acid-degradable film during the cotton seedling stage. Daytime soil temperatures were 0.8℃ and 6.2℃ lower under 18μm and 15μm thick polyactic acid-degradable film than non-degradable plastic film(CK, respectively. Nighttime soil temperatures under the polyactic acid-degradable film were about 1℃ warmer than CK. There was no significant difference in cotton yields between the 18μm polyactic acid degradable film treatment and CK. In contrast, yields in the 15μm degradable plastic film treatment were 8.9% less than that in CK. This study indicated that 18μm polyactic acid degradable plastic film had good degradability and no negative effect on cotton growth. The 18μm polyactic acid degradable plastic film can replace ordinary plastic film in agricultural production.

Degradation of phorbol 12,13-diacetate in aqueous solution by gamma irradiation

International Nuclear Information System (INIS)

Kongmany, Santi; Furuta, Masakazu; Matsuura, Hiroto; Okuda, Shuichi; Imamura, Kiyoshi; Maeda, Yasuaki

2014-01-01

Phorbol esters (PEs) are highly toxic compounds that cause skin irritation, inflammation, and tumor promotion upon contact with humans or animals. These compounds are naturally present in Jatropha curcas L. To promote the use of J. curcas seed oil in bio-diesel production industries and reduce environmental concerns, it is necessary to find methods of degrading PEs. In this study, the degradation of phorbol 12,13-diacetate (PDA), as a representative PE, in aqueous solution at a concentration of 10 mg/L by 60 Co-γ-irradiation was investigated. The results demonstrate that PDA was effectively degraded by this treatment and the degradation efficiency increased with the absorbed dose within the range of 0.5–3 kGy. Complete degradation of PDA was achieved at a dose of 3 kGy. In the presence of radical scavengers (i.e., methanol, tert-butanol, 2-propanol), reactive species from water radiolysis were scavenged, and significant inhibition of PDA degradation was observed at absorbed doses less than 1 kGy. In the presence of nitrous oxide, the generation of hydroxyl radicals (·OH) was promoted during gamma irradiation and PDA degradation was drastically enhanced. - Highlights: • PDA in aqueous solution was effectively degraded by gamma irradiation. • Hydroxyl radical mainly contributed to PDA degradation. • Intermediate product produced from PDA degradation was further decomposed. • Gamma irradiation process can be useful for degrading phorbol esters in water

A global fouling factor methodology for analyzing steam generator thermal performance degradation

International Nuclear Information System (INIS)

Kreider, M.A.; White, G.A.; Varrin, R.D. Jr.

1998-06-01

Over the past few years, steam generator (SG) thermal performance degradation has led to decreased plant efficiency and power output at numerous PWR nuclear power plants with recirculating-type SGs. The authors have developed and implemented methodologies for quantitatively evaluating the various sources of SG performance degradation, both internal and external to the SG pressure boundary. These methodologies include computation of the global fouling factor history, evaluation of secondary deposit thermal resistance using deposit characterization data, and consideration of pressure loss causes unrelated to the tube bundle, such as hot-leg temperature streaming and SG moisture separator fouling. In order to evaluate the utility of the global fouling factor methodology, the authors performed case studies for a number of PWR SG designs. Key results from two of these studies are presented here. In tandem with the fouling-factor analyses, a study evaluated for each plant the potential causes of pressure loss. The combined results of the global fouling factor calculations and the pressure-loss evaluations demonstrated two key points: (1) that the available thermal margin against fouling, which can vary substantially from plant to plant, has an important bearing on whether a given plant exhibits losses in electrical generating capacity, and (2) that a wide variety of causes can result in SG thermal performance degradation

Isolation of amoebic-bacterial consortia capable of degrading trichloroethylene

International Nuclear Information System (INIS)

Tyndall, R.L.; Ironside, K.; Little, C.D.; Katz, S.; Kennedy, J.

1990-01-01

Groundwater from a waste disposal site contaminated with chlorinated alkenes was examined for the presence of amoebic-bacterial consortia capable of degrading the suspected carcinogen, trichloroethylene (TCE). Consortia were readily isolated from all of four test wells. They contained free-living amoebae, and heterotrophic and methylotrophic bacteria. Electron microscopic examination showed bacteria localized throughout the amoebic cytoplasm and an abundance of hyphomicrobium, but not Type I methanotrophs. The presence of Type II methanotrophs was indirectly indicated by lipid analysis of one consortium. The consortia have been passaged for over two years on mineral salts media in a methane atmosphere, which would not be expected to maintain the heterotrophs or amoebae separately. The methanotrophic bacteria apparently provided a stable nutrient source, allowing the persistence of the various genera. By use of 14 C-radiotracer techniques, the degradation of TCE by the consortia was observed with 14 C eventuating predominantly in CO 2 and water-soluble products. In a more detailed examination of one consortia, the amoebae and heterotrohic components did not degrade TCE, while a mixed culture of heterotrophs and methanotrophs did degrade TCE, suggesting the latter component was the primary cause for the consortium's ability to degrade TCE. Amoebic-bacterial consortia may play a role in stabilizing and preserving methylotrophic bacteria in hostile environments

Ceftriaxone and clavulanic acid induce antiallodynia and anti-inflammatory effects in rats using the carrageenan model

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Ochoa-Aguilar A

2018-05-01

Full Text Available Abraham Ochoa-Aguilar,1,2 Rosa Ventura-Martinez,1 Marco Antonio Sotomayor-Sobrino,1 Ruth Jaimez,1 Ulises Coffeen,3 Ariadna Jiménez-González,2 Luis Gerardo Balcázar-Ochoa,1 Rafael Pérez-Medina-Carballo,2 Rodolfo Rodriguez,1 Ricardo Plancarte-Sánchez4 1Pharmacology Department, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, México; 2Research Department, Mexican Faculty of Medicine, La Salle University, Mexico City, México; 3Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Mexico City, México; 4Pain Clinic, National Cancer Institute of Mexico, Mexico City, México Introduction: Ceftriaxone (CFX and clavulanic acid (CA are 2 β-lactam molecules widely used as antibiotics. However, several reports of their antiallodynic properties have been published in recent years. Although this effect has been considered mostly due to a GLT1 overexpression, these molecules have also been proven to induce direct immunomodulation. In this work, we determine the acute analgesic effect of CFX and CA in an inflammatory pain model and assess if their administration may induce anti-inflammatory effects. Methods: The carrageenan (Carr test was used as an inflammatory pain model. Both mechanical and thermal responses were analyzed after CFX and CA administration at different times. A plethysmometer was used to determine inflammation. Also, TNF-α and IL-10 serum concentrations were determined by enzyme-linked immunosorbent assay. Results: Both CFX and CA induced a significant thermal antiallodynic effect 3 and 24 h after administration. Furthermore, CA induced a mechanical antiallodynic effect 30, 60, and 90 min after administration. Moreover, a significant anti-inflammatory effect was found for both molecules 24 h after Carr injection. Also, both CA and CFX modulated TNF-α and IL-10 serum concentrations at different times. Conclusion: Our results provide evidence that both CFX and CA cause an analgesic effect on a Carr

In-operation inspection technology development 'development of degradation prediction technology for rotating machinery'

International Nuclear Information System (INIS)

Osaki, K.; Watanabe, Y.; Uhara, Y.; Hattori, H.; O'shima, E.; Matsumoto, K.

2001-01-01

In order to rationalize facility maintenance management and improve reliabilities of rotating machines, it is desirable to develop the technology for estimating bearing wear and predicting bearing wear growth. Therefore, we developed a bearing wear analysis method for evaluating bearing wear growth in the mixed lubrication, and developed a degradation prediction system which estimates the bearing wear and predicts bearing wear growth from external parameters, such as shaft vibration. In bearing wear analysis, the influence of bearing surface roughness and elastic deformation are considered. This analysis model was validated by the bearing wear test. The developed system can predict degradation respecting bearing wear, casing deformation, shaft curvature and bearing sleeve corrosion, using some physical models of degradation that take into account various degradation phenomena. Furthermore, this system can estimate bearing life, taking into consideration the distribution of the vibration characteristic caused by the differences in assembling processes and the distribution of the degradation characteristic. This system was validated by the degradation simulation test. (authors)

Abiotic and biotic degradation of oxo-biodegradable plastic bags by Pleurotus ostreatus.

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José Maria Rodrigues da Luz

Full Text Available In this study, we evaluated the growth of Pleurotus ostreatus PLO6 using oxo-biodegradable plastics as a carbon and energy source. Oxo-biodegradable polymers contain pro-oxidants that accelerate their physical and biological degradation. These polymers were developed to decrease the accumulation of plastic waste in landfills. To study the degradation of the plastic polymers, oxo-biodegradable plastic bags were exposed to sunlight for up to 120 days, and fragments of these bags were used as substrates for P. ostreatus. We observed that physical treatment alone was not sufficient to initiate degradation. Instead, mechanical modifications and reduced titanium oxide (TiO2 concentrations caused by sunlight exposure triggered microbial degradation. The low specificity of lignocellulolytic enzymes and presence of endomycotic nitrogen-fixing microorganisms were also contributing factors in this process.

Abiotic and biotic degradation of oxo-biodegradable plastic bags by Pleurotus ostreatus.

Science.gov (United States)

da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Bazzolli, Denise Mara Soares; Tótola, Marcos Rogério; Demuner, Antônio Jacinto; Kasuya, Maria Catarina Megumi

2014-01-01

In this study, we evaluated the growth of Pleurotus ostreatus PLO6 using oxo-biodegradable plastics as a carbon and energy source. Oxo-biodegradable polymers contain pro-oxidants that accelerate their physical and biological degradation. These polymers were developed to decrease the accumulation of plastic waste in landfills. To study the degradation of the plastic polymers, oxo-biodegradable plastic bags were exposed to sunlight for up to 120 days, and fragments of these bags were used as substrates for P. ostreatus. We observed that physical treatment alone was not sufficient to initiate degradation. Instead, mechanical modifications and reduced titanium oxide (TiO2) concentrations caused by sunlight exposure triggered microbial degradation. The low specificity of lignocellulolytic enzymes and presence of endomycotic nitrogen-fixing microorganisms were also contributing factors in this process.

Abiotic and Biotic Degradation of Oxo-Biodegradable Plastic Bags by Pleurotus ostreatus

Science.gov (United States)

da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Bazzolli, Denise Mara Soares; Tótola, Marcos Rogério; Demuner, Antônio Jacinto; Kasuya, Maria Catarina Megumi

2014-01-01

In this study, we evaluated the growth of Pleurotus ostreatus PLO6 using oxo-biodegradable plastics as a carbon and energy source. Oxo-biodegradable polymers contain pro-oxidants that accelerate their physical and biological degradation. These polymers were developed to decrease the accumulation of plastic waste in landfills. To study the degradation of the plastic polymers, oxo-biodegradable plastic bags were exposed to sunlight for up to 120 days, and fragments of these bags were used as substrates for P. ostreatus. We observed that physical treatment alone was not sufficient to initiate degradation. Instead, mechanical modifications and reduced titanium oxide (TiO2) concentrations caused by sunlight exposure triggered microbial degradation. The low specificity of lignocellulolytic enzymes and presence of endomycotic nitrogen-fixing microorganisms were also contributing factors in this process. PMID:25419675

Effects of organic degradation products on the sorption of actinides

Energy Technology Data Exchange (ETDEWEB)

Baston, G.M.N.; Berry, J.A.; Bond, K.A.; Brownsword, M.; Linklater, C.M. (AEA Decommissioning and Radwaste, Harwell Lab. (United Kingdom))

1992-01-01

Previous work has shown that products from the chemical degradation of cellulosic matter can significantly reduce sorption of uranium(VI) and plutonium(IV) on geological materials. Uranium(IV) batch sorption experiments have now been performed to study the effect of organic degradation products in a reducing environment. Thorium(IV) sorption has also been studied since thorium is an important radioelement in its own right and has potential use as a simulant for other tetravalent actinides. Sorption onto London clay, Caithness flagstones and St. Bees sandstone was investigated. Experimental conditions were chosen to simulate both those expected close to cementitious repository (pH [proportional to] 11) and at the edge of the zone of migration of the alkaline plume (pH [proportional to] 8). Work was carried out with both authentic degradation products and with gluconate, acting as a well-characterized simulant for cellulosic degradation products. The results show that the presence of organic species can cause a reduction in sorption. This is especially so in the presence of a high concentration of gluconate ions, but the reduction is significantly less with authentic degradation products. (orig.).

Influences of the selected additives on the weight loss and organoleptic properties of marinated mussels and squids

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Metin Guldas

2012-01-01

Full Text Available Effects of seven different solutions prepared from various additives (carrageenan, konjac flour, phosphate, yeast extract, xanthan gum and maltodextrin were used to test for the first time in the marination of experimental seafood. The additives were added into the marination solutions and the samples were analyzed before and after marination. Statistically, the experimental solutions did not cause significant changes in pH, acidity and salt content of the samples (P P < 0.01. The organoleptic properties (mouth feel, flavour and softness of mussels and squids were also improved by carrageenan LM addition.

Experimental Strategy to Discover Microbes with Gluten-degrading Enzyme Activities.

Science.gov (United States)

Helmerhorst, Eva J; Wei, Guoxian

2014-05-05

Gluten proteins contained in the cereals barley, rye and wheat cause an inflammatory disorder called celiac disease in genetically predisposed individuals. Certain immunogenic gluten domains are resistant to degradation by mammalian digestive enzymes. Enzymes with the ability to target such domains are potentially of clinical use. Of particular interest are gluten-degrading enzymes that would be naturally present in the human body, e.g. associated with resident microbial species. This manuscript describes a selective gluten agar approach and four enzyme activity assays, including a gliadin zymogram assay, designed for the selection and discovery of novel gluten-degrading microorganisms from human biological samples. Resident and harmless bacteria and/or their derived enzymes could potentially find novel applications in the treatment of celiac disease, in the form of a probiotic agent or as a dietary enzyme supplement.

Degradation of l-polylactide during melt processing with layered double hydroxides

DEFF Research Database (Denmark)

Gerds, Nathalie; Katiyar, Vimal; Koch, Christian Bender

2012-01-01

PLA was melt compounded in small-scale batches with two forms of laurate-modified magnesium–aluminum layered double hydroxide (Mg-Al-LDH-C12), the corresponding carbonate form (Mg-Al-LDH-CO3) and a series of other additives. Various methods were then adopted to characterize the resulting compounds...... in an effort to gain greater insights into PLA degradation during melt processing. PLA molecular weight reduction was found to vary according to the type of LDH additive. It is considered that the degree of particle dispersion and LDH exfoliation, and hence the accessibility of the hydroxide layer surfaces...... and catalytically active Mg site centers are causative factors for PLA degradation. Interestingly, the release of water under the processing conditions was found to have a rather small effect on the PLA degradation. Low loadings of sodium laurate also caused PLA degradation indicating that carboxylate chain ends...

Degradation of polyethylene by Trichoderma harzianum--SEM, FTIR, and NMR analyses.

Science.gov (United States)

Sowmya, H V; Ramalingappa; Krishnappa, M; Thippeswamy, B

2014-10-01

Trichoderma harzianum was isolated from local dumpsites of Shivamogga District for use in the biodegradation of polyethylene. Soil sample of that dumpsite was used for isolation of T. harzianum. Degradation was carried out using autoclaved, UV-treated, and surface-sterilized polyethylene. Degradation was monitored by observing weight loss and changes in physical structure by scanning electron microscopy, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. T. harzianum was able to degrade treated polyethylene (40%) more efficiently than autoclaved (23%) and surface-sterilized polyethylene (13%). Enzymes responsible for polyethylene degradation were screened from T. harzianum and were identified as laccase and manganese peroxidase. These enzymes were produced in large amount, and their activity was calculated using spectrophotometric method and crude extraction of enzymes was carried out. Molecular weight of laccase was determined as 88 kDa and that of manganese peroxidase was 55 kDa. The capacity of crude enzymes to degrade polyethylene was also determined. By observing these results, we can conclude that this organism may act as solution for the problem caused by polyethylene in nature.

[Oil degradation by basidiomycetes in soil and peat at low temperatures].

Science.gov (United States)

Kulikova, N A; Klein, O I; Pivchenko, D V; Landesman, E O; Pozdnyakova, N N; Turkovskaya, O V; Zaichik, B Ts; Ruzhitskii, A O; Koroleva, O V

2016-01-01

A total of 17 basidiomycete strains causing white rot and growing on oil-contaminated substrates have been screened. Three strains with high (Steccherinum murashkinskyi), average (Trametes maxima), and low (Pleurotus ostreatus) capacities for the colonization of oil-contaminated substrates have been selected. The potential for degrading crude oil hydrocarbons has been assessed with the use of fungi grown on nonsterile soil and peat at low temperatures. Candida sp. and Rhodococcus sp. commercial strains have been used as reference organisms with oil-degrading ability. All microorganisms introduced in oil-contaminated soil have proved to be ineffective, whereas the inoculation of peat with basidiomycetes and oil-degrading microorganisms accelerated the destruction of oil hydrocarbons. The greatest degradation potential of oil-aliphatic hydrocarbons has been found in S. murashlinskyi. T. maxima turned out to be the most successful in degrading aromatic hydrocarbons. It has been suggested that aboriginal microflora contributes importantly to the effectiveness of oil-destructing microorganisms. T. maxima and S. murashkinskyi strains are promising for further study as oil-oxidizing agents during bioremediation of oil-contaminated peat soil under conditions of low temperatures.

Evidence for age-related performance degradation of (241)Am foil sources commonly used in UK schools.

Science.gov (United States)

Whitcher, R; Page, R D; Cole, P R

2014-06-01

The characteristics of alpha radiation have for decades been demonstrated in UK schools using small sealed (241)Am sources. There is a small but steady number of schools who report a considerable reduction in the alpha count rate detected by an end-window GM detector compared with when the source was new. This cannot be explained by incorrect apparatus or set-up, foil surface contamination, or degradation of the GM detector. The University of Liverpool and CLEAPSS collaborated to research the cause of this performance degradation. The aim was to find what was causing the performance degradation and the ramifications for both the useful and safe service life of the sources. The research shows that these foil sources have greater energy straggling with a corresponding reduction in spectral peak energy. A likely cause for this increase in straggling is a significant diffusion of the metals over time. There was no evidence to suggest the foils have become unsafe, but precautionary checks should be made on old sources.

Overview of the age-related degradation of nuclear power plant structures

International Nuclear Information System (INIS)

Deng, Daniel

2004-01-01

License renewal of nuclear power plants is an issue of increasing interest to the U.S. nuclear industry and the U.S. NRC. This paper presents and evaluates the plausible age-related degradation mechanisms that may affect the concrete and steel containment structures and other Class I structures to continue to perform their safety functions. Preventive and/or mitigative options are outlined for managing degradation mechanisms that could significantly affect plant performance during the license renewal period. The provided technical information and the degradation management options may be used as references for comparison with plant specific conditions to ensure that age-related degradation is controlled during the license renewal term. Plausible degradation mechanisms described and analyzed as they may affect the concrete, reinforcing steel, containment steel shell, prestressed-tendon, steel liner and other structural components typically used in Class I structures. The significance of these age-related degradation mechanisms to the structural components are evaluated, giving consideration to the design basis and quality of construction; typical service conditions; operating and maintenance history; and current test, inspection and refurbishment practices for containment and Class I structures. Degradation mechanisms which cannot be generically dispositioned on the basis of the two-step approach: (1) they will not cause significant degradation, or (2) any potential degradation will be bounded by current test, inspection, analytical evaluation, and/or refurbishment programs are identified. Aging degradation management measures are recommended to address the remaining age-related degradation mechanisms. A three-phase approach for the management of the containment and Class I structures is introduced. Various techniques, testing tools and the acceptable criteria for each step of the evaluation of the structures status are provided. The preventive and mitigative

ENHANCEMENT OF RESISTANCE TO OXIDATIVE DEGRADATION OF NATURAL RUBBER THROUGH LATEX DEGRADATION

Institute of Scientific and Technical Information of China (English)

无

1998-01-01

A fully characterised natural rubber latex was subjected to mechanical degradation by stirring at intervals. The resistance to oxidative degradation of the different samples were studied by measuring the Plasticity retention indices (PRI).The results show that there is an enhancement of the PRI from 57% for the undegraded rubber to 79% for the one-hour degraded sample. Further degradation resulted in decrease of PRI as time of degradation increased. Therefore, the one-hour degraded sample is a special rubber with high oxidation resistance which is of great importance in engineering.

Determination of Polymers Thermal Degradation by Color Change Analysis

Directory of Open Access Journals (Sweden)

Andrés Felipe Rojas González

2016-01-01

Full Text Available Context: It has been observed that thermal degradation of thermoplastic polymers, when they are reprocessed by injection, extrusion and extrusion / injection, undergo color changes in the product, although it not has been established as this change occurs. Method: It analyzed the effect on thermal degradation caused by polymer type, processing type, polymer grade, rotation speed of the extrusion screw and number of reprocessing, which is quantified by the color change using an empirical equation, with experimental data obtained by analysis through a microcolor colorimeter. Results: It was found that the color change analysis provides information about progress of the thermal degradation and stability of thermoplastic polymers, which are undergoing to multiple reprocessing events and processes. Conclusions: It was established that this technique can be implemented as a simple and efficient measure of thermoplastic products quality control, according to their color change.

Impact of composting strategies on the degradation of nonylphenol in sewage sludge.

Science.gov (United States)

Zheng, Guodi; Chen, Tongbin; Yu, Jie; Gao, Ding; Shen, Yujun; Niu, Mingjie; Liu, Hongtao

2015-12-01

Nonylphenol can be present in sewage sludge, and this can limit the use of the sewage sludge to amend soil. Composting is one of the most efficient and economical methods of making sewage sludge stable and harmless. The nonylphenol degradation rates during composting with added bulking agents and with aeration applied were studied. Three organic bulking agents (sawdust, corn stalk, and mushroom residue) were added to sewage sludge, and the effects of the bulking agents used and the amount added on nonylphenol degradation were determined. The highest apparent nonylphenol degradation rate (71.6%) was found for sewage sludge containing 20% mushroom residue. The lowest apparent nonylphenol degradation rate (22.5%) was found for sewage sludge containing 20% sawdust. The temperature of the composting pile of sewage sludge containing 20% sawdust became too high for nonylphenol to be efficiently degraded, and the apparent nonylphenol degradation rate was lower than was found for sewage sludge containing 10% sawdust. Increasing the ventilating time from 5 to 15 min increased the apparent nonylphenol degradation rate from 19.7 to 41.6%. Using appropriate aerobic conditions facilitates the degradation of nonylphenol in sewage sludge, decreasing the risks posed by sewage sludge applied to land. Adding too much of a bulking agent can decrease the amount of the nonylphenol degraded. Increasing the ventilating time and the amount of air supplied can increase the amount of nonylphenol degraded even if doing so causes the composting pile temperature to remain low.

Negative charge induced degradation of PMOSFETs with BF2-implanted p+-poly gate

International Nuclear Information System (INIS)

Lu, C.Y.; Sung, J.M.

1989-01-01

A new degradation phenomenon on thin gate oxide PMOS-FETs with BF 2 implanted p + -poly gate has been demonstrated and investigated. The cause of this type of degradation is a combination of the boron penetration through the gate oxide and charge trap generation due to the presence of fluorine in the gate oxide and some other processing-induced effects. The negative charge-induced degradation other than enhanced boron diffusion has been studied in detail here. The impact of this process-sensitive p + -poly gate structure on deep submicron CMOS process integration has been discussed. (author)

Polyox and carrageenan based composite film dressing containing anti-microbial and anti-inflammatory drugs for effective wound healing.

Science.gov (United States)

Boateng, Joshua S; Pawar, Harshavardhan V; Tetteh, John

2013-01-30

Polyethylene oxide (Polyox) and carrageenan based solvent cast films have been formulated as dressings for drug delivery to wounds. Films plasticised with glycerol were loaded with streptomycin (30%, w/w) and diclofenac (10%, w/w) for enhanced healing effects in chronic wounds. Blank and drug loaded films were characterised by texture analysis (for mechanical and mucoadhesive properties), scanning electron microscopy, differential scanning calorimetry, X-ray diffraction and Fourier transform infrared spectroscopy. In addition, swelling, in vitro drug release and antibacterial studies were conducted to further characterise the films. Both blank and drug loaded films showed a smooth, homogeneous surface morphology, excellent transparency, high elasticity and acceptable tensile (mechanical) properties. The drug loaded films showed a high capacity to absorb simulated wound fluid and significant mucoadhesion force which is expected to allow effective adherence to and protection of the wound. The films showed controlled release of both streptomycin and diclofenac for 72 h. These drug loaded films produced higher zones of inhibition against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli compared to the individual drugs zones of inhibition. Incorporation of streptomycin can prevent and treat chronic wound infections whereas diclofenac can target the inflammatory phase of wound healing to relieve pain and swelling. Copyright © 2012 Elsevier B.V. All rights reserved.

Release mechanism of doxazosin from carrageenan matrix tablets: Effect of ionic strength and addition of sodium dodecyl sulphate.

Science.gov (United States)

Kos, Petra; Pavli, Matej; Baumgartner, Saša; Kogej, Ksenija

2017-08-30

The polyelectrolyte matrix tablets loaded with an oppositely charged drug exhibit complex drug-release mechanisms. In this study, the release mechanism of a cationic drug doxazosin mesylate (DM) from matrix tablets based on an anionic polyelectrolyte λ-carrageenan (λ-CARR) is investigated. The drug release rates from λ-CARR matrices are correlated with binding results based on potentiometric measurements using the DM ion-sensitive membrane electrode and with molecular characteristics of the DM-λ-CARR-complex particles through hydrodynamic size measurements. Experiments are performed in solutions with different ionic strength and with the addition of an anionic surfactant sodium dodecyl sulphate (SDS). It is demonstrated that in addition to swelling and erosion of tablets, the release rates depend strongly on cooperative interactions between DM and λ-CARR. Addition of SDS at concentrations below its critical micelle concentration (CMC) slows down the DM release through hydrophobic binding of SDS to the DM-λ-CARR complex. On the contrary, at concentrations above the CMC SDS pulls DM from the complex by forming mixed micelles with it and thus accelerates the release. Results involving SDS show that the concentration of surfactants that are naturally present in gastrointestinal environment may have a great impact on the drug release process. Copyright © 2017 Elsevier B.V. All rights reserved.

Engineering a degradable polyurethane intravaginal ring for sustained delivery of dapivirine.

Science.gov (United States)

Kaur, Manpreet; Gupta, Kavita M; Poursaid, Azadeh E; Karra, Prasoona; Mahalingam, Alamelu; Aliyar, Hyder A; Kiser, Patrick F

2011-06-01

We describe the engineering of a degradable intravaginal ring (IVR) for the delivery of the potent HIV-1 reverse transcriptase inhibitor dapivirine. The degradable polymer used in fabricating the device incorporated poly(caprolactone) ester blocks in a poly(tetramethylene ether) glycol ABA type polyurethane backbone. The polymer was designed to maintain its structure for 1 month during usage and then degrade in the environment post-disposal. In vitro release of dapivirine showed zero-order kinetics for up to 1 month and significant levels of drug release into engineered vaginal tissue. The mechanical properties of the degradable IVR were comparable to those of a widely used contraceptive intravaginal ring upon exposure to simulated vaginal conditions. Incubation under simulated vaginal conditions for a month caused minimal degradation with minimal effect on the mechanical properties of the ring and polymer. The cytotoxicity evaluation of the drug-loaded IVRs against Vk2/E6E7 human vaginal epithelial cells, Lactobacillus jensenii, and engineered vaginal tissue constructs showed the degradable polyurethane to be non-toxic. In vitro evaluation of inflammatory potential monitored through the levels of inflammatory cytokines IL-8, IL-1α, IL-6, IL-1β, and MIP-3α when engineered EpiVaginal™ tissue was incubated with the polyurethanes suggested that the degradable polyurethane was comparable to commercial medical grade polyurethane. These results are encouraging for further development of this degradable IVR for topical vaginal delivery of microbicides.

Diagnosis of Feedwater Heater Performance Degradation using Fuzzy Approach

International Nuclear Information System (INIS)

Kim, Hyeonmin; Kang, Yeon Kwan; Heo, Gyunyoung; Song, Seok Yoon

2014-01-01

It is inevitable to avoid degradation of component, which operates continuously for long time in harsh environment. Since this degradation causes economical loss and human loss, it is important to monitor and diagnose the degradation of component. The diagnosis requires a well-systematic method for timely decision. Before this article, the methods using regression model and diagnosis table have been proposed to perform the diagnosis study for thermal efficiency in Nuclear Power Plants (NPPs). Since the regression model was numerically less-stable under changes of operating variables, it was difficult to provide good results in operating plants. Contrary to this, the diagnosis table was hard to use due to ambiguous points and to detect how it affects degradation. In order to cover the issues of previous researches, we proposed fuzzy approaches and applied it to diagnose Feedwater Heater (FWH) degradation to check the feasibility. The degradation of FWHs is not easy to be observed, while trouble such as tube leakage may bring simultaneous damage to the tube bundle. This study explains the steps of diagnosing typical failure modes of FWHs. In order to cover the technical issues of previous researches, we adopted fuzzy logic to suggest a diagnosis algorithm for the degradation of FHWs and performed feasibility study. In this paper, total 7 modes of FWH degradation modes are considered, which are High Drain Level, Low Shell Pressure, Tube Pressure Increase, Tube Fouling, Pass Partition Plate Leakage, Tube Leakage, Abnormal venting. From the literature survey and simulation, diagnosis table for FWH is made. We apply fuzzy logic based on diagnosis table. Authors verify fuzzy diagnosis for FWH degradation synthesized the random input sets from made diagnosis table. Comparing previous researches, suggested method more-stable under changes of operating variables, than regression model. On the contrary, the problem which ambiguous points and detect how it affects degradation

Diagnosis of Feedwater Heater Performance Degradation using Fuzzy Approach

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyeonmin; Kang, Yeon Kwan; Heo, Gyunyoung [Kyung Hee Univ., Yongin (Korea, Republic of); Song, Seok Yoon [Korea Hydro and Nuclear Power, Daejeon (Korea, Republic of)

2014-05-15

It is inevitable to avoid degradation of component, which operates continuously for long time in harsh environment. Since this degradation causes economical loss and human loss, it is important to monitor and diagnose the degradation of component. The diagnosis requires a well-systematic method for timely decision. Before this article, the methods using regression model and diagnosis table have been proposed to perform the diagnosis study for thermal efficiency in Nuclear Power Plants (NPPs). Since the regression model was numerically less-stable under changes of operating variables, it was difficult to provide good results in operating plants. Contrary to this, the diagnosis table was hard to use due to ambiguous points and to detect how it affects degradation. In order to cover the issues of previous researches, we proposed fuzzy approaches and applied it to diagnose Feedwater Heater (FWH) degradation to check the feasibility. The degradation of FWHs is not easy to be observed, while trouble such as tube leakage may bring simultaneous damage to the tube bundle. This study explains the steps of diagnosing typical failure modes of FWHs. In order to cover the technical issues of previous researches, we adopted fuzzy logic to suggest a diagnosis algorithm for the degradation of FHWs and performed feasibility study. In this paper, total 7 modes of FWH degradation modes are considered, which are High Drain Level, Low Shell Pressure, Tube Pressure Increase, Tube Fouling, Pass Partition Plate Leakage, Tube Leakage, Abnormal venting. From the literature survey and simulation, diagnosis table for FWH is made. We apply fuzzy logic based on diagnosis table. Authors verify fuzzy diagnosis for FWH degradation synthesized the random input sets from made diagnosis table. Comparing previous researches, suggested method more-stable under changes of operating variables, than regression model. On the contrary, the problem which ambiguous points and detect how it affects degradation

Non-Destructive Analysis of Degradation Mechanisms in Cycle-Aged Graphite/LiCoO2 Batteries

Directory of Open Access Journals (Sweden)

Liqiang Zhang

2014-09-01

Full Text Available Non-destructive analysis of degradation mechanisms can be very beneficial for the prognostics and health management (PHM study of lithium-ion batteries. In this paper, a type of graphite/LiCoO2 battery was cycle aged at high ambient temperature, then 25 parameters of the multi-physics model were identified. Nine key parameters degraded with the cycle life, and they were treated as indicators of battery degradation. Accordingly, the degradation mechanism was discussed by using the multi-physics model and key parameters, and the reasons for capacity fade and the internal resistance increase were analyzed in detail. All evidence indicates that the formation reaction of the solid electrolyte interface (SEI film is the main cause of battery degradation at high ambient temperature.

Restoring Soil Quality to Mitigate Soil Degradation

Directory of Open Access Journals (Sweden)

Rattan Lal

2015-05-01

Full Text Available Feeding the world population, 7.3 billion in 2015 and projected to increase to 9.5 billion by 2050, necessitates an increase in agricultural production of ~70% between 2005 and 2050. Soil degradation, characterized by decline in quality and decrease in ecosystem goods and services, is a major constraint to achieving the required increase in agricultural production. Soil is a non-renewable resource on human time scales with its vulnerability to degradation depending on complex interactions between processes, factors and causes occurring at a range of spatial and temporal scales. Among the major soil degradation processes are accelerated erosion, depletion of the soil organic carbon (SOC pool and loss in biodiversity, loss of soil fertility and elemental imbalance, acidification and salinization. Soil degradation trends can be reversed by conversion to a restorative land use and adoption of recommended management practices. The strategy is to minimize soil erosion, create positive SOC and N budgets, enhance activity and species diversity of soil biota (micro, meso, and macro, and improve structural stability and pore geometry. Improving soil quality (i.e., increasing SOC pool, improving soil structure, enhancing soil fertility can reduce risks of soil degradation (physical, chemical, biological and ecological while improving the environment. Increasing the SOC pool to above the critical level (10 to 15 g/kg is essential to set-in-motion the restorative trends. Site-specific techniques of restoring soil quality include conservation agriculture, integrated nutrient management, continuous vegetative cover such as residue mulch and cover cropping, and controlled grazing at appropriate stocking rates. The strategy is to produce “more from less” by reducing losses and increasing soil, water, and nutrient use efficiency.

EVALUATION AND MAPPING OF RANGELANDS DEGRADATION USING REMOTELY SENSED DATA

Directory of Open Access Journals (Sweden)

Majid Ajorlo

2005-05-01

Full Text Available The empirical and scientifically documents prove that misuse of natural resource causes degradation in it. So natural resources conservation is important in approaching sustainable development aims. In current study, Landsat Thematic Mapper images and grazing gradient method have been used to map the extent and degree of rangeland degradation. In during ground-based data measuring, factors such as vegetation cover, litter, plant diversity, bare soil, and stone & gravels were estimated as biophysical indicators of degradation. The next stage, after geometric correction and doing some necessary pre-processing practices on the study area’s images; the best and suitable vegetation index has been selected to map rangeland degradation among the Normalized Difference Vegetation Index (NDVI, Soil Adjusted Vegetation Index (SAVI, and Perpendicular Vegetation Index (PVI. Then using suitable vegetation index and distance parameter was produced the rangelands degradation map. The results of ground-based data analysis reveal that there is a significant relation between increasing distance from critical points and plant diversity and also percentage of litter. Also there is significant relation between vegetation cover percent and distance from village, i.e. the vegetation cover percent increases by increasing distance from villages, while it wasn’t the same around the stock watering points. The result of analysis about bare soil and distance from critical point was the same to vegetation cover changes manner. Also there wasn’t significant relation between stones & gravels index and distance from critical points. The results of image processing show that, NDVI appears to be sensitive to vegetation changes along the grazing gradient and it can be suitable vegetation index to map rangeland degradation. The degradation map shows that there is high degradation around the critical points. These areas need urgent attention for soil conservation. Generally, it

Prevention of Tibetan eco-environmental degradation caused by traditional use of biomass

Energy Technology Data Exchange (ETDEWEB)

Wang, Qiang [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China)

2009-12-15

Tibet is short in fossil energy, but rich in renewable energy sources, such as biomass, hydro, solar, geothermal, and wind power. This potential energy supply in Tibet can be juxtaposed to what drives Tibetan energy consumption its economic motivation and its cultural traditions. Currently, biomass heavily dominates Tibet's energy consumption. In 2003, total energy consumption was about 2 million tce (ton coal equivalent), traditional biomass accounting for nearly 70%. The rarified atmosphere and use of outdated stoves, make for a very low combustion efficiency, utilizing 10-15% of the potential energy of biomass. With population and economic growth, traditional use of biomass has become the principal factor responsible for deforestation, grassland degradation, desertification, and soil erosion. To eradicate the negative impact of the traditional use of biomass on the eco-environment in Tibet, a series of effective countermeasures are investigated. Among these are improved efficiency of stoves, widespread use of solar energy, hydroelectricity as a substitute for traditional biomass, and the development of biogas. (author)

Program plan for correction of US instrument degradation or failure in the Upper Plenum Test Facility (UPTF) in the Federal Republic of Germany

International Nuclear Information System (INIS)

Rhee, G.S.; Chen, Y.S.; Shotkin, L.M.

1987-07-01

This report documents, as of September, 1986, the investigation of the failure or degradation of some of the advanced two-phase flow instruments supplied by the United States Nuclear Regulatory Commission (USNRC) to the German Upper Plenum Test Facility (UPTF). These instruments include Tie-Plate Drag Bodies (DBs), Breakthrough Detectors (BTDs), Loop Drag Disc (DD) paddles, Fluid Distribution Grid (FDG) sensors, and Liquid Level Detector (LLD) sensors. The exact causes for these instrument degradations or failures are not known, but several potential causes have been identified. For DBs and BTDs, the primary mechanism for the degradation appears to be a leakage in the Inconel 600 strain gage encapsulation and the subsequent burnout of the strain gage elements. Excessive loads appear to be the cause of the degradation or failure of the drag discs. The degradation cause for most of the FDGs and LLDs may be either steam/water erosion or mechanical abrasion of the sapphire sensor tips. However, some of the FDG tips were found to be cracked also. The corrective actions are being directed towards identification of the primary causes for the instrument degradation or failure and methods of preventing recurrance and toward minimizing the impact on the test program. All possible action items are being reviewed to arrange them in terms of priority and the likelihood of success so that the best results can be obtained under the constraints of a fixed amount of resources and limited time

Implications of a New Global Picture of Land Degradation (Invited)

Science.gov (United States)

Olsson, L.; Dent, D.

2009-12-01

Effective responses to desertification have always been hampered by a lack of a scientific understanding and reliable data on the extent and severity of land degradation. We also argue that the poor scientific understanding of desertification is partly a consequence of the lack of reliable data. Policy development has to a large extent relied upon data from the 1990 GLASOD assessment that was compiled from expert judgements. This is a map of perceptions, not measurements, that doesn't stand scrutiny and lent itself to selective interpretations. Based on the GLASOD assessment, land degradation in arid and semi-arid regions have been emphasised over other regions as hotspots of land degradation. A recent analysis of consistent, remotely-sensed data and climatic observations, using clearly-defined methods, makes allowance for droughts and global warming. It indicates that 24 per cent of land has suffered declining net primary productivity over the last 25 years; this area is home to a quarter of the world's people. When adjusted for climatic variations, the loss of primary productivity is interpreted as land degradation. In contrast to received wisdom, dry lands don't feature strongly. Forests and croplands are most affected by land degradation and protected areas fare no better than anywhere else. Unprecedented land use change is being driven not only by local processes but also by external pressures related to burgeoning population, economic & technology developments and globalisation; and unsustainable land use is causing land degradation. This suggests a need for a policy shift from desertification in dry lands to land degradation globally, and from environmental protection to developmental initiatives. The paper will discuss potential responses to land degradation that are informed by the new insights into the extent and severity of land degradation globally.

Organic chemical degradation by remote study of the redox conditions

Science.gov (United States)

Fernandez, P. M.; Revil, A.; Binley, A. M.; Bloem, E.; French, H. K.

2014-12-01

Monitoring the natural (and enhanced) degradation of organic contaminants is essential for managing groundwater quality in many parts of the world. Contaminated sites often have limited access, hence non-intrusive methods for studying redox processes, which drive the degradation of organic compounds, are required. One example is the degradation of de-icing chemicals (glycols and organic salts) released to the soil near airport runways during winter. This issue has been broadly studied at Oslo airport, Gardermoen, Norway using intrusive and non-intrusive methods. Here, we report on laboratory experiments that aim to study the potential of using a self-potential, DCresistivity, and time-domain induced polarization for geochemical characterization of the degradation of Propylene Glycol (PG). PG is completely miscible in water, does not adsorb to soil particles and does not contribute to the electrical conductivity of the soil water. When the contaminant is in the unsaturated zone near the water table, the oxygen is quickly consumed and the gas exchange with the surface is insufficient to ensure aerobic degradation, which is faster than anaerobic degradation. Since biodegradation of PG is highly oxygen demanding, anaerobic pockets can exist causing iron and manganese reduction. It is hypothesised that nitrate would boost the degradation rate under such conditions. In our experiment, we study PG degradation in a sand tank. We provide the system with an electron highway to bridge zones with different redox potential. This geo-battery system is characterized by self-potential, resistivity and induced polarization anomalies. An example of preliminary results with self-potential at two different times of the experiment can be seen in the illustration. These will be supplemented with more direct information on the redox chemistry: in-situ water sampling, pH, redox potential and electrical conductivity measurements. In parallel, a series of batch experiments have been

High-power UV-LED degradation: Continuous and cycled working condition influence

Science.gov (United States)

Arques-Orobon, F. J.; Nuñez, N.; Vazquez, M.; Segura-Antunez, C.; González-Posadas, V.

2015-09-01

High-power (HP) UV-LEDs can replace UV lamps for real-time fluoro-sensing applications by allowing portable and autonomous systems. However, HP UV-LEDs are not a mature technology, and there are still open issues regarding their performance evolution over time. This paper presents a reliability study of 3 W UV-LEDs, with special focus on LED degradation for two working conditions: continuous and cycled (30 s ON and 30 s OFF). Accelerated life tests are developed to evaluate the influence of temperature and electrical working conditions in high-power LEDs degradation, being the predominant failure mechanism the degradation of the package. An analysis that includes dynamic thermal and optical HP UV-LED measurements has been performed. Static thermal and stress simulation analysis with the finite element method (FEM) identifies the causes of package degradation. Accelerated life test results prove that HP UV-LEDs working in cycled condition have a better performance than those working in continuous condition.

Precision Diagnosis, Monitoring and Control of Structural Component Degradation in Nuclear Power Plants

International Nuclear Information System (INIS)

Han, J. H.; Choi, M. S.; Lee, D. H.; Hur, D. H.; Na, J. W.; Kim, K. M.; Hong, J. H.; Kim, H. S.

2007-06-01

The occurrence of structural material degradations in NPPs and their progress during operation are directly related to the safety and the integrity of NPPs. The various kinds of material degradation are usually examined by methods of material integrity evaluation and non-destructive evaluation(NDE). Material integrity evaluation is well known as classical method to interpret cause and mechanism of degradation and failure, however, this method has a limitation of detection and diagnosis for actual condition of flaws and defects occurring during plant operation, particularly for their formation in the early stage. NDE used widely for detection of defects formed on structural materials provides many information for safety regulation, plant management, repairing, however, this technique has a generic problem in its reliability due to low detectability and ability of signal analysis, etc. The objective of this research project is to develop the advanced technologies ensuring a precision diagnosis on the various kind of defects in structural materials of NPP and a high performance in material degradation evaluation. Many of the advanced technologies were developed in the 1st phase of this project. They contributed to interpret more precisely the root causes of degradation, failure and to establish the proper measures for the safety and integrity of NPPs. The accomplishment of comprehensive technology developed as planned will be practically applied to the nuclear industries and contributed to improve the safety and integrity of NPPs

Bioprinting three-dimensional cell-laden tissue constructs with controllable degradation.

Science.gov (United States)

Wu, Zhengjie; Su, Xin; Xu, Yuanyuan; Kong, Bin; Sun, Wei; Mi, Shengli

2016-04-19

Alginate hydrogel is a popular biologically inert material that is widely used in 3D bioprinting, especially in extrusion-based printing. However, the printed cells in this hydrogel could not degrade the surrounding alginate gel matrix, causing them to remain in a poorly proliferating and non-differentiating state. Here, we report a novel study of the 3D printing of human corneal epithelial cells (HCECs)/collagen/gelatin/alginate hydrogel incubated with a medium containing sodium citrate to obtain degradation-controllable cell-laden tissue constructs. The 3D-printed hydrogel network with interconnected channels and a macroporous structure was stable and achieved high cell viability (over 90%). By altering the mole ratio of sodium citrate/sodium alginate, the degradation time of the bioprinting constructs can be controlled. Cell proliferation and specific marker protein expression results also revealed that with the help of sodium citrate degradation, the printed HCECs showed a higher proliferation rate and greater cytokeratin 3(CK3) expression, indicating that this newly developed method may help to improve the alginate bioink system for the application of 3D bioprinting in tissue engineering.

Land degradation in Northern Nigeria: The impacts and implications ...

African Journals Online (AJOL)

Otoigiakih

2013-04-27

Apr 27, 2013 ... expansion and agricultural intensification have been suggested to be part of the causes of land degradation in. Africa (including Nigeria). The possible loss of natural vegetation cover due to changes in land use, influenced by man, could expose the soil surface and render it vulnerable to the elements of ...

Progress in Understanding Degradation Mechanisms and Improving Stability in Organic Photovoltaics

KAUST Repository

Mateker, William R.

2016-12-23

Understanding the degradation mechanisms of organic photovoltaics is particularly important, as they tend to degrade faster than their inorganic counterparts, such as silicon and cadmium telluride. An overview is provided here of the main degradation mechanisms that researchers have identified so far that cause extrinsic degradation from oxygen and water, intrinsic degradation in the dark, and photo-induced burn-in. In addition, it provides methods for researchers to identify these mechanisms in new materials and device structures to screen them more quickly for promising long-term performance. These general strategies will likely be helpful in other photovoltaic technologies that suffer from insufficient stability, such as perovskite solar cells. Finally, the most promising lifetime results are highlighted and recommendations to improve long-term performance are made. To prevent degradation from oxygen and water for sufficiently long time periods, OPVs will likely need to be encapsulated by barrier materials with lower permeation rates of oxygen and water than typical flexible substrate materials. To improve stability at operating temperatures, materials will likely require glass transition temperatures above 100 °C. Methods to prevent photo-induced burn-in are least understood, but recent research indicates that using pure materials with dense and ordered film morphologies can reduce the burn-in effect.

Progress in Understanding Degradation Mechanisms and Improving Stability in Organic Photovoltaics

KAUST Repository

Mateker, William R.; McGehee, Michael D.

2016-01-01

Understanding the degradation mechanisms of organic photovoltaics is particularly important, as they tend to degrade faster than their inorganic counterparts, such as silicon and cadmium telluride. An overview is provided here of the main degradation mechanisms that researchers have identified so far that cause extrinsic degradation from oxygen and water, intrinsic degradation in the dark, and photo-induced burn-in. In addition, it provides methods for researchers to identify these mechanisms in new materials and device structures to screen them more quickly for promising long-term performance. These general strategies will likely be helpful in other photovoltaic technologies that suffer from insufficient stability, such as perovskite solar cells. Finally, the most promising lifetime results are highlighted and recommendations to improve long-term performance are made. To prevent degradation from oxygen and water for sufficiently long time periods, OPVs will likely need to be encapsulated by barrier materials with lower permeation rates of oxygen and water than typical flexible substrate materials. To improve stability at operating temperatures, materials will likely require glass transition temperatures above 100 °C. Methods to prevent photo-induced burn-in are least understood, but recent research indicates that using pure materials with dense and ordered film morphologies can reduce the burn-in effect.

Structural degradation of Thar lignite using MW1 fungal isolate: optimization studies

Science.gov (United States)

Haider, Rizwan; Ghauri, Muhammad A.; Jones, Elizabeth J.; Orem, William H.; SanFilipo, John R.

2015-01-01

Biological degradation of low-rank coals, particularly degradation mediated by fungi, can play an important role in helping us to utilize neglected lignite resources for both fuel and non-fuel applications. Fungal degradation of low-rank coals has already been investigated for the extraction of soil-conditioning agents and the substrates, which could be subjected to subsequent processing for the generation of alternative fuel options, like methane. However, to achieve an efficient degradation process, the fungal isolates must originate from an appropriate coal environment and the degradation process must be optimized. With this in mind, a representative sample from the Thar coalfield (the largest lignite resource of Pakistan) was treated with a fungal strain, MW1, which was previously isolated from a drilled core coal sample. The treatment caused the liberation of organic fractions from the structural matrix of coal. Fungal degradation was optimized, and it showed significant release of organics, with 0.1% glucose concentration and 1% coal loading ratio after an incubation time of 7 days. Analytical investigations revealed the release of complex organic moieties, pertaining to polyaromatic hydrocarbons, and it also helped in predicting structural units present within structure of coal. Such isolates, with enhanced degradation capabilities, can definitely help in exploiting the chemical-feedstock-status of coal.

Experimental degradation of polymer shopping bags (standard and degradable plastic, and biodegradable) in the gastrointestinal fluids of sea turtles.

Science.gov (United States)

Müller, Christin; Townsend, Kathy; Matschullat, Jörg

2012-02-01

The persistence of marine debris such as discarded polymer bags has become globally an increasing hazard to marine life. To date, over 177 marine species have been recorded to ingest man-made polymers that cause life-threatening complications such as gut impaction and perforation. This study set out to test the decay characteristics of three common types of shopping bag polymers in sea turtle gastrointestinal fluids (GIF): standard and degradable plastic, and biodegradable. Fluids were obtained from the stomachs, small intestines and large intestines of a freshly dead Green turtle (Chelonia mydas) and a Loggerhead turtle (Caretta caretta). Controls were carried out with salt and freshwater. The degradation rate was measured over 49 days, based on mass loss. Degradation rates of the standard and the degradable plastic bags after 49 days across all treatments and controls were negligible. The biodegradable bags showed mass losses between 3 and 9%. This was a much slower rate than reported by the manufacturers in an industrial composting situation (100% in 49 days). The GIF of the herbivorous Green turtle showed an increased capacity to break down the biodegradable polymer relative to the carnivorous Loggerhead, but at a much lower rate than digestion of natural vegetative matter. While the breakdown rate of biodegradable polymers in the intestinal fluids of sea turtles is greater than standard and degradable plastics, it is proposed that this is not rapid enough to prevent morbidity. Further study is recommended to investigate the speed at which biodegradable polymers decompose outside of industrial composting situations, and their durability in marine and freshwater systems. Copyright © 2011 Elsevier B.V. All rights reserved.

Temporal changes in wood crystalline cellulose during degradation by brown rot fungi

DEFF Research Database (Denmark)

Howell, Caitlin; Hastrup, Anne Christine Steenkjær; Goodell, Barry

2009-01-01

The degradation of wood by brown rot fungi has been studied intensely for many years in order to facilitate the preservation of in-service wood. In this work we used X-ray diffraction to examine changes in wood cellulose crystallinity caused by the brown rot fungi Gloeophyllum trabeum, Coniophora...... planes in all degraded samples after roughly 20% weight loss, as well as a decrease in the average observed relative peak width at 2¿ = 22.2°. These results may indicate a disruption of the outer most semi-crystalline cellulose chains comprising the wood microfibril. X-ray diffraction analysis of wood...... subjected to biological attack by fungi may provide insight into degradative processes and wood cellulose structure....

A review of proton exchange membrane water electrolysis on degradation mechanisms and mitigation strategies

Science.gov (United States)

Feng, Qi; Yuan, Xiao-Zi; Liu, Gaoyang; Wei, Bing; Zhang, Zhen; Li, Hui; Wang, Haijiang

2017-10-01

Proton exchange membrane water electrolysis (PEMWE) is an advanced and effective solution to the primary energy storage technologies. A better understanding of performance and durability of PEMWE is critical for the engineers and researchers to further advance this technology for its market penetration, and for the manufacturers of PEM water electrolyzers to implement quality control procedures for the production line or on-site process monitoring/diagnosis. This paper reviews the published works on performance degradations and mitigation strategies for PEMWE. Sources of degradation for individual components are introduced. With degradation causes discussed and degradation mechanisms examined, the review emphasizes on feasible strategies to mitigate the components degradation. To avoid lengthy real lifetime degradation tests and their high costs, the importance of accelerated stress tests and protocols is highlighted for various components. In the end, R&D directions are proposed to move the PEMWE technology forward to become a key element in future energy scenarios.

Electrochemical AC impedance model of a solid oxide fuel cell and its application to diagnosis of multiple degradation modes

Energy Technology Data Exchange (ETDEWEB)

Gazzarri, J.I.; Kesler, O. [Department of Mechanical Engineering, University of British Columbia, 2054-6250 Applied Science Lane, Vancouver, BC V6T 1Z4 (Canada)

2007-05-01

A finite element model of the impact of diverse degradation mechanisms on the impedance spectrum of a solid oxide fuel cell is presented as a tool for degradation mode identification. Among the degradation mechanisms that cause electrode active area loss, the attention is focused on electrode delamination and uniformly distributed surface area loss, which were found to cause distinct and specific changes in the impedance spectrum. Degradation mechanisms resulting in uniformly distributed reactive surface area loss include sintering, sulphur poisoning, and possibly incipient coke formation at the anode, and chromium deposition at the cathode. Parametric studies reveal the extent and limits of applicability of the model and detectability of the different degradation modes, as well as the influence of different cell geometries on the change in impedance behaviour resulting from the loss of active area. It is expected that this technique could form the basis of a useful diagnostic tool for both solid oxide fuel cell developers and users. (author)

Risk-informed assessment of degraded containment structures

International Nuclear Information System (INIS)

Spencer, B.W.; Kunsman, D.M.; Graves, H.L.

2003-01-01

As nuclear power plants age, a number of degradation mechanisms may begin to affect the ability of critical containment structures to prevent radiation release during a severe accident. A research program is underway to quantify the effects of various types of containment degradation in a risk-informed manner. In this paper, corrosion is assumed to occur in the liner of a reinforced concrete containment at a 'typical' U.S. pressurized water reactor nuclear power plant, and its effect is investigated. Latin hypercube sampling is used in conjunction with finite element models of a typical steel-lined reinforced concrete containment to generate overpressurization fragilities of the containment with and without corrosion. An existing probabilistic risk assessment model of the plant is then used with these fragilities to determine the increase in risk caused by the corrosion. (author)

Kinetic and mechanistic study of microcystin-LR degradation by nitrous acid under ultraviolet irradiation.

Science.gov (United States)

Ma, Qingwei; Ren, Jing; Huang, Honghui; Wang, Shoubing; Wang, Xiangrong; Fan, Zhengqiu

2012-05-15

Degradation of microcystin-LR (MC-LR) in the presence of nitrous acid (HNO(2)) under irradiation of 365nm ultraviolet (UV) was studied for the first time. The influence of initial conditions including pH value, NaNO(2) concentration, MC-LR concentration and UV intensity were studied. MC-LR was degraded in the presence of HNO(2); enhanced degradation of MC-LR was observed with 365nm UV irradiation, caused by the generation of hydroxyl radicals through the photolysis of HNO(2). The degradation processes of MC-LR could well fit the pseudo-first-order kinetics. Mass spectrometry was applied for identification of the byproducts and the analysis of degradation mechanisms. Major degradation pathways were proposed according to the results of LC-MS analysis. The degradation of MC-LR was initiated via three major pathways: attack of hydroxyl radicals on the conjugated carbon double bonds of Adda, attack of hydroxyl radicals on the benzene ring of Adda, and attack of nitrosonium ion on the benzene ring of Adda. Copyright © 2012 Elsevier B.V. All rights reserved.

Management-induced Soil Structure Degradation: Organic Matter Depletion and Tillage

OpenAIRE

Kay, B.D.; Munkholm, L.J.

2004-01-01

Soil structure is an important element of soil quality since changes in structural characteristics can cause changes in the ability of soil to fulfil different functions and services. Emphasis in this chapter is placed on the role of soil structure in biological productivity of agroecosystems. Combinations of management practices in which the extent of the degradation of soil structure caused by one practice is balanced or exceeded by the extent of regeneration by other practices will help su...

Anthropogenic causes of wetland loss and degradation in the lower Kłodnica valley (southern Poland

Directory of Open Access Journals (Sweden)

Wójcicki Krzysztof J.

2015-12-01

Full Text Available Loss and degradation of wetlands is now one of the most important environmental issues on a global scale. Previous research based on analyses of cartographic materials allow for quantification of changes in wetland area in recent centuries. The results of lithological research of peat cores, reported in this publication, have established that the processes of anthropogenic loss of wetlands can be much older and in the Kłodnica valley were initiated in the first millennium BC. As a result of increased mineral sedimentation accompanying soil erosion some peatlands have been fossilized whilst the area of others has been reduced. In total, the surface area of peat-forming wetlands in the bottom of the Kłodnica valley decreased by over 60% between the time of the Lusatian Culture settlement and the Middle Ages. Post-peatland habitats are recently used for agricultural or colonized by non-peat forming vegetation. These processes have played a more important role in the degradation of peatland ecosystems than the direct human impact in historic times. Changes in hydrographic networks, land drainage and regulation of water levels in rivers and canals in the last century have contributed to further reducing the wetland areas by almost 50% compared to the 1880s. These processes, however, have mainly affected ephemeral non-peat forming wetlands.

Polymer electrolyte membrane water electrolysis: Restraining degradation in the presence of fluctuating power

Science.gov (United States)

Rakousky, Christoph; Reimer, Uwe; Wippermann, Klaus; Kuhri, Susanne; Carmo, Marcelo; Lueke, Wiebke; Stolten, Detlef

2017-02-01

Polymer electrolyte membrane (PEM) water electrolysis generates 'green' hydrogen when conducted with electricity from renewable - but fluctuating - sources like wind or solar photovoltaic. Unfortunately, the long-term stability of the electrolyzer performance is still not fully understood under these input power profiles. In this study, we contrast the degradation behavior of our PEM water electrolysis single cells that occurs under operation with constant and intermittent power and derive preferable operating states. For this purpose, five different current density profiles are used, of which two were constant and three dynamic. Cells operated at 1 A cm-2 show no degradation. However, degradation was observed for the remaining four profiles, all of which underwent periods of high current density (2 A cm-2). Hereby, constant operation at 2 A cm-2 led to the highest degradation rate (194 μV h-1). Degradation can be greatly reduced when the cells are operated with an intermittent profile. Current density switching has a positive effect on durability, as it causes reversible parts of degradation to recover and results in a substantially reduced degradation per mole of hydrogen produced. Two general degradation phenomena were identified, a decreased anode exchange current density and an increased contact resistance at the titanium porous transport layer (Ti-PTL).

A thermo-degradable hydrogel with light-tunable degradation and drug release.

Science.gov (United States)

Hu, Jingjing; Chen, Yihua; Li, Yunqi; Zhou, Zhengjie; Cheng, Yiyun

2017-01-01

The development of thermo-degradable hydrogels is of great importance in drug delivery. However, it still remains a huge challenge to prepare thermo-degradable hydrogels with inherent degradation, reproducible, repeated and tunable dosing. Here, we reported a thermo-degradable hydrogel that is rapidly degraded above 44 °C by a facile chemistry. Besides thermo-degradability, the hydrogel also undergoes rapid photolysis with ultraviolet light. By embedding photothermal nanoparticles or upconversion nanoparticles into the gel, it can release the entrapped cargoes such as dyes, enzymes and anticancer drugs in an on-demand and dose-tunable fashion upon near-infrared light exposure. The smart hydrogel works well both in vitro and in vivo without involving sophisticated syntheses, and is well suited for clinical cancer therapy due to the high transparency and non-invasiveness features of near-infrared light. Copyright © 2016 Elsevier Ltd. All rights reserved.

Organic matter degradation in Chilean sediments - following nature's own degradation experiment

DEFF Research Database (Denmark)

Langerhuus, Alice Thoft; Niggemann, Jutta; Lomstein, Bente Aagaard

ORGANIC MATTER DEGRADATION IN CHILEAN SEDIMENTS – FOLLOWING NATURE’S OWN DEGRADATION EXPERIMENT Degradation of sedimentary organic matter was studied at two stations from the shelf of the Chilean upwelling region. Sediment cores were taken at 1200 m and 800 m water depth and were 4.5 m and 7.5 m...... in length, respectively. The objective of this study was to assess the degradability of the organic matter from the sediment surface to the deep sediments. This was done by analysing amino acids (both L- and D-isomers) and amino sugars in the sediment cores, covering a timescale of 15.000 years. Diagenetic...... indicators (percentage of carbon and nitrogen present as amino acid carbon and nitrogen, the ratio between a protein precursor and its non-protein degradation product and the percentage of D-amino acids) revealed ongoing degradation in these sediments, indicating that microorganisms were still active in 15...

Photocatalytic degradation of sunscreen active ingredients mediated by nanostructured materials

Science.gov (United States)

Soto-Vazquez, Loraine

Water scarcity and pollution are environmental issues with terrible consequences. In recent years several pharmaceutical and personal care products, such as sunscreen active ingredients, have been detected in different water matrices. Its recalcitrant behavior in the environment has caused controversies and generated countless questions about its safety. During this research, we employed an advanced oxidation process (photocatalysis) to degrade sunscreen active ingredients. For this study, we used a 3x3 system, evaluating three photocatalysts and three different contaminants. From the three catalysts employed, two of them were synthesized. ZnO nanoparticles were obtained using zinc acetate dihydrated as the precursor, and TiO2 nanowires were synthesized from titanium tetrachloride precursor. The third catalyst employed (namely, P25) was obtained commercially. The synthesized photocatalysts were characterized in terms of the morphology, elemental composition, crystalline structure, elemental oxidation states, vibrational modes and surface area, using SEM-EDS, XRD, XPS, Raman spectroscopy and BET measurements, respectively. The photocatalysts were employed during the study of the degradation of p-aminobenzoic acid, phenylbenzimidazole sulfonic acid, and benzophenone-4. In all the cases, at least 50% degradation was achieved. P25 showed degradation efficiencies above 90%, and from the nine systems, 7 of them degraded at least 86%.

Laboratory Evaluation of Interactions in the Degradation of a Polypropylene Geotextile in Marine Environments

Directory of Open Access Journals (Sweden)

José Ricardo Carneiro

2018-01-01

Full Text Available The long-term behaviour of geosynthetics applied in coastal engineering structures can be adversely affected by many agents. This paper studies the resistance of a nonwoven polypropylene geotextile against some degradation agents present in marine environments and evaluates the existence of interactions between them. For that purpose, the geotextile was exposed to some laboratory degradation tests: immersion tests (in seawater, deionised water, and sodium chloride 35 g·L−1, thermooxidation, and artificial weathering. The geotextile was (1 exposed separately to each degradation test and (2 exposed successively to combinations of two or three degradation tests. The damage caused by the degradation tests was evaluated by monitoring the tensile properties of the geotextile. Based on the changes occurred in tensile strength, reduction factors were determined. The reduction factors obtained directly in the multiple exposures were compared with those obtained by the traditional methodology for the combined effect of the degradation agents. The results, among other findings, showed the existence of relevant interactions between the degradation agents and showed that the reduction factors obtained by the traditional methodology were unable to represent accurately (by underestimating the degradation occurred in the geotextile.

Environmental degradation, population displacement and global security: An overview of the issues

International Nuclear Information System (INIS)

1992-12-01

An initial investigation is presented on the interrelationship between environmental degradation and population displacements, in the broader context of how this linkage affects human security. Emphasis is placed on both the causes and effects of population movements, with specific examples drawn from Southeast Asia. Types of migrants, the importance of environmental degradation with respect to other contributing factors, and the effects on origin and destination regions are considered. A key issue is the multi-causality of population displacements and the importance of improving understanding of the issues in order to develop appropriate policies. It is clear from the study that the discussion of environment as a cause or contributing factor to population displacement has, to date, been speculative, and the information provided largely anecdotal. 58 refs., 1 fig., 3 tabs

[Subluxation of scleral-fixated PC IOL caused by polypropylene suture degradation--case report].

Science.gov (United States)

Kanigowska, Krystyna; Grałek, Mirosława; Czarnowska, Elzbieta; Zajaczkowska, Agnieszka

2009-01-01

The purpose of the study is to evaluate factors related to late-onset of lens subluxation in transscleral sutured posterior chamber IOL. We report a child, which required surgical treatment for dislocation of a scleral-sutured PC IOL. 11 years earlier the secondary lens implantation with scleral fixation was performed in 4 years old boy. The first surgical procedure included an anterior victrectomy and suturing a single- piece PMMA IOL under the scleral flaps with a 10-0 polipropylene suture. The second--included explantation of the dislocated lens. Optic and scanning electron microscopy was used to analyze the surface of the explanted remnants of the breakage suture. Microscopic findings indicate that the late suture breakage and subluxation of suture-fixated PC IOL was due to the degradation of polypropylene suture.

Flow accelerated organic coating degradation

Science.gov (United States)

Zhou, Qixin

Applying organic coatings is a common and the most cost effective way to protect metallic objects and structures from corrosion. Water entry into coating-metal interface is usually the main cause for the deterioration of organic coatings, which leads to coating delamination and underfilm corrosion. Recently, flowing fluids over sample surface have received attention due to their capability to accelerate material degradation. A plethora of works has focused on the flow induced metal corrosion, while few studies have investigated the flow accelerated organic coating degradation. Flowing fluids above coating surface affect corrosion by enhancing the water transport and abrading the surface due to fluid shear. Hence, it is of great importance to understand the influence of flowing fluids on the degradation of corrosion protective organic coatings. In this study, a pigmented marine coating and several clear coatings were exposed to the laminar flow and stationary immersion. The laminar flow was pressure driven and confined in a flow channel. A 3.5 wt% sodium chloride solution and pure water was employed as the working fluid with a variety of flow rates. The corrosion protective properties of organic coatings were monitored inline by Electrochemical Impedance Spectroscopy (EIS) measurement. Equivalent circuit models were employed to interpret the EIS spectra. The time evolution of coating resistance and capacitance obtained from the model was studied to demonstrate the coating degradation. Thickness, gloss, and other topography characterizations were conducted to facilitate the assessment of the corrosion. The working fluids were characterized by Fourier Transform Infrared Spectrometer (FTIR) and conductivity measurement. The influence of flow rate, fluid shear, fluid composition, and other effects in the coating degradation were investigated. We conclude that flowing fluid on the coating surface accelerates the transport of water, oxygen, and ions into the coating, as

Characterization of the growth and degradation of glycogen in the liver

International Nuclear Information System (INIS)

Youn, J.; Bergman, R.

1986-01-01

The patterns of the growth and degradation of hepatic glycogen were studied using a computer model. The database was that of Devos and Hers on the distribution of label in glycogen from [1- 14 C] galactose injected at different times after the start of refeeding 40 h fasted mice. The data was simulated to examine the following hypotheses (H): Glycogen Synthesis H.S1: all glycogen molecules grow simultaneously. H.S2: at each moment of synthesis only a fixed number of molecules grow. H.S3: the number of growing molecules increases linearly with respect to time. H.S4: increase in the number of growing molecules is accelerated as glycogen is synthesized. Glycogen Degradation H.D1: glycogen molecules to be attacked by degrading enzymes are randomly chosen. H.D2: glycogen molecules are degraded sequentially in the reverse order of synthesis. H.D3: glycogen molecules have different probabilities of degradation depending upon the time of synthesis. The growth and degradation according to hypotheses S4 and D3, respectively, could best account for the data. The modelling study predicts that, at the beginning of refeeding, only a small number of molecules grow. But, as glycogen is synthesized, the rate of seeding of new glycogen molecules increases with time, causing a nonlinear proliferation of the number of growing molecules. During degradation glycogen molecules synthesized later have a greater chance to be degraded first, a characteristic which may be explained by the rosette structure of liver glycogen

A new strategy for the modification of a carbon paste electrode with carrageenan hydrogel for a sensitive and selective determination of arsenic in natural waters.

Science.gov (United States)

Núñez, Claudia; Arancibia, Verónica; Triviño, Juan José

2018-09-01

An adsorptive stripping voltammetric method for the determination of As(III) and As total in water samples using a carrageenan modified carbon paste electrode is presented for the first time (CAR-CPE). The modified electrode was prepared in different ways: by adding CAR in solid form or as a hydrogel together with graphite and paraffin, as well as adsorbing CAR by applying a potential on an unmodified carbon paste electrode. The best results were obtained when CAR was incorporated as hydrogel (HCAR-CPE). The selection of the ratio amounts for electrode preparation was carried out applying a multivariate experimental design. Variables like amount of graphite (U 1 ), HCAR (U 2 ) and paraffin (U 3 ) were optimized using a (2 K +2K+C) model. The results showed that the amount of HCAR was the most significant factor, and the adequate U 1 :U 2 :U 3 ratio to prepare the electrode was: 493 mg of graphite, 214 μL of paraffin and 134 μL of carrageenan as gel. The optimum parameters for the determination of As(III) were pH = 3.25 (0.01 mol L -1 H 3 PO 4 /H 2 PO 4 - solution); E acc = -0.50 V and t acc = 30 s. The electrode presents good linear behavior concentration range from 0.50 to 6.70 μg L -1 , with a limit of detection of 0.22 μg L -1 . The relative standard deviation was 5.0% at the 1.5 μg L -1 As(III) level (n = 16). The method was validated by quantifying As(III) in spiked tap water from laboratory (RE: 3.0%), and it was applied for the determination of As total in water samples from the Loa River (North of Chile) prior reduction of As(V) with Na 2 S 2 O 3 solution, obtaining 814.00 ± 0.03 μg L -1 . The results of the proposed method were compared with those obtained by adsorptive stripping voltammetry with HMDE and by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) techniques. Copyright © 2018 Elsevier B.V. All rights reserved.

Molecular Identification of Bacteria Involved in Degradation of Crude ...

African Journals Online (AJOL)

ISSN: 0189 1731. Available online at http://www.ajol.info/index.php/njb/index ... activities is a main cause of water and soil pollution. One of the ... 60% reduction in household food security and were capable of .... isolates to degrade crude oil, mineral salt media was .... to help maintain the cold chain and prevent the DNA ...

Modeling Day-to-day Flow Dynamics on Degradable Transport Network

Science.gov (United States)

Gao, Bo; Zhang, Ronghui; Lou, Xiaoming

2016-01-01

Stochastic link capacity degradations are common phenomena in transport network which can cause travel time variations and further can affect travelers’ daily route choice behaviors. This paper formulates a deterministic dynamic model, to capture the day-to-day (DTD) flow evolution process in the presence of degraded link capacity degradations. The aggregated network flow dynamics are driven by travelers’ study of uncertain travel time and their choice of risky routes. This paper applies the exponential-smoothing filter to describe travelers’ study of travel time variations, and meanwhile formulates risk attitude parameter updating equation to reflect travelers’ endogenous risk attitude evolution schema. In addition, this paper conducts theoretical analyses to investigate several significant mathematical characteristics implied in the proposed DTD model, including fixed point existence, uniqueness, stability and irreversibility. Numerical experiments are used to demonstrate the effectiveness of the DTD model and verify some important dynamic system properties. PMID:27959903

Applicability of X-ray reflectometry to studies of polymer solar cell degradation

DEFF Research Database (Denmark)

Andreasen, Jens Wenzel; Gevorgyan, Suren; Schleputz, C.M.

2008-01-01

Although degradation of polymer solar cells is widely acknowledged, the cause, physical or chemical, has not been identified. The purpose of this work is to determine the applicability of X-ray reflectometry for in situ observation of physical degradation mechanisms. We find that the rough...... interfaces of the polymer solar cell constituent layers seriously obstruct the sensitivity of the technique, rendering it impossible to elucidate changes in the layer/interface structure at the sub-nanometer level. (c) 2008 Elsevier B.V. All rights reserved....

Mechanisms of c-myc degradation by nickel compounds and hypoxia.

Directory of Open Access Journals (Sweden)

Qin Li

2009-12-01

Full Text Available Nickel (Ni compounds have been found to cause cancer in humans and animal models and to transform cells in culture. At least part of this effect is mediated by stabilization of hypoxia inducible factor (HIF1a and activating its downstream signaling. Recent studies reported that hypoxia signaling might either antagonize or enhance c-myc activity depending on cell context. We investigated the effect of nickel on c-myc levels, and demonstrated that nickel, hypoxia, and other hypoxia mimetics degraded c-myc protein in a number of cancer cells (A549, MCF-7, MDA-453, and BT-474. The degradation of the c-Myc protein was mediated by the 26S proteosome. Interestingly, knockdown of both HIF-1alpha and HIF-2alpha attenuated c-Myc degradation induced by Nickel and hypoxia, suggesting the functional HIF-1alpha and HIF-2alpha was required for c-myc degradation. Further studies revealed two potential pathways mediated nickel and hypoxia induced c-myc degradation. Phosphorylation of c-myc at T58 was significantly increased in cells exposed to nickel or hypoxia, leading to increased ubiquitination through Fbw7 ubiquitin ligase. In addition, nickel and hypoxia exposure decreased USP28, a c-myc de-ubiquitinating enzyme, contributing to a higher steady state level of c-myc ubiquitination and promoting c-myc degradation. Furthermore, the reduction of USP28 protein by hypoxia signaling is due to both protein degradation and transcriptional repression. Nickel and hypoxia exposure significantly increased the levels of dimethylated H3 lysine 9 at the USP28 promoter and repressed its expression. Our study demonstrated that Nickel and hypoxia exposure increased c-myc T58 phosphorylation and decreased USP28 protein levels in cancer cells, which both lead to enhanced c-myc ubiquitination and proteasomal degradation.

An ensemble classifier to predict track geometry degradation

International Nuclear Information System (INIS)

Cárdenas-Gallo, Iván; Sarmiento, Carlos A.; Morales, Gilberto A.; Bolivar, Manuel A.; Akhavan-Tabatabaei, Raha

2017-01-01

Railway operations are inherently complex and source of several problems. In particular, track geometry defects are one of the leading causes of train accidents in the United States. This paper presents a solution approach which entails the construction of an ensemble classifier to forecast the degradation of track geometry. Our classifier is constructed by solving the problem from three different perspectives: deterioration, regression and classification. We considered a different model from each perspective and our results show that using an ensemble method improves the predictive performance. - Highlights: • We present an ensemble classifier to forecast the degradation of track geometry. • Our classifier considers three perspectives: deterioration, regression and classification. • We construct and test three models and our results show that using an ensemble method improves the predictive performance.

Degradation of microbial polyesters.

Science.gov (United States)

Tokiwa, Yutaka; Calabia, Buenaventurada P

2004-08-01

Microbial polyhydroxyalkanoates (PHAs), one of the largest groups of thermoplastic polyesters are receiving much attention as biodegradable substitutes for non-degradable plastics. Poly(D-3-hydroxybutyrate) (PHB) is the most ubiquitous and most intensively studied PHA. Microorganisms degrading these polyesters are widely distributed in various environments. Although various PHB-degrading microorganisms and PHB depolymerases have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. Distributions of PHB-degrading microorganisms, factors affecting the biodegradability of PHB, and microbial and enzymatic degradation of PHB are discussed in this review. We also propose an application of a new isolated, thermophilic PHB-degrading microorganism, Streptomyces strain MG, for producing pure monomers of PHA and useful chemicals, including D-3-hydroxycarboxylic acids such as D-3-hydroxybutyric acid, by enzymatic degradation of PHB.

Causes for torque degradation during deceleration and the effect on the driving range of battery electric vehicles

Energy Technology Data Exchange (ETDEWEB)

Lieb, Johannes [BMW PEUGEOT CITROEN ELECTRIFICATION, Muenchen (Germany); Wilde, Andreas [BMW Group, Muenchen (Germany); Baeker, Bernard [Dresden Univ. of Technology (Germany). Dept. of Vehicle Mechatronics

2012-11-01

The ability to regain considerable amounts of the kinetic energy during deceleration phases is a key aspect to increase the efficiency of battery electric vehicles (BEV). Especially in urban and highly congested areas brake energy recovery (BER) can drastically improve the vehicle's driving range. However, due to the high power peaks that go along even with moderate braking maneuvers, severe requirements are being put on the electric drivetrain. Any limitation of power in one of the components of the powertrain inevitably leads to degradation of the regenerative brake torque, thus limiting the car's energy regeneration capability. Without an integrated brake system that can compensate the torque variations during deceleration, BER may need to be decreased even further to prevent a loss of driving comfort due to dynamic changes in the vehicle's behavior. This paper deals with the causes of these torque restraints within the electric drivetrain and how they affect the energy consumption and therefore the electric driving range. A simulation environment was set up and verified based on an existing BEV to conduct parameter studies and depict the sensitivities towards environmental influences. The calculated efficiencies are based on standard drive cycles and incorporate continuous fading between regenerative braking and the use of friction brakes. Special attention was laid on the battery system since energy storage still poses a particular challenge in the development of electric vehicles. Also through the high mutual dependence of the various parameters of the battery enviromental influences become most evident. (orig.)

Evaluation of Maltose-Induced Chemical Degradation at the Interface of Bilayer Tablets.

Science.gov (United States)

Matsuzaki, Naoya; Yamamoto, Yousuke; Murayama, Daisuke; Katakawa, Yoshifumi; Mimura, Hisashi; Kimura, Shin-Ichiro; Iwao, Yasunori; Itai, Shigeru

2017-01-01

Fixed dose combination tablets consisting of mirabegron (MB) and solifenacin succinate (SS) were developed and formulated into bilayer tablets in the current study. The results of a chemical stability study showed that the original formulation for the tablets led to a significant increase of unknown degradants in the SS layer. Two compatibility studies were conducted to simulate the interface between the MB and SS layers, and the results revealed that the degradants only formed in the presence of both active pharmaceutical ingredients (APIs), and that the presence of maltose in the SS layer was critical to inducing degradation. High resolution mass spectroscopy coupled with high performance liquid chromatography was used to determine the chemical structures of the degradants, which were identified to MB derivatives bearing one or two sugar units. These findings therefore suggested that the degradation of the API could be attributed to the addition of sugar units from maltose to MB under the acidic conditions caused by SS. With this in mind, we developed a new formulation by replacing maltose with hydroxypropyl cellulose as a polymer-type binder. The results showed that this formulation suppressed the formation of the degradants. The results of this study have shown that chemical degradation can occur at the interface of bilayer tablets and that an alternative strategy is available to formulate more stable MB/SS bilayer tablets.