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Sample records for non-enzymatic browning reaction

  1. The Effect of Irradiation Treatment on the Non-Enzymatic Browning Reaction in Legume Seeds

    International Nuclear Information System (INIS)

    El-Niely, H.F.G.

    2013-01-01

    The present study was conducted to evaluate the effects of gamma irradiation treatment, at room temperature, on the non-enzymatic browning reaction (Millerd reaction products, MRPs) generated in soybeans, broad beans and dried peas seeds at dose levels of 10, 30 and 60 kGy and their effects on the chemical constituents, soluble protein, available lysine and in vitro protein digestibility. The formation of MRPs in the studied legumes was assayed by monitoring the formation of brown pigments (browning intensity) by spectrophotometric method. The results revealed that the chemical composition of irradiated legumes showed non-significant differences relative to the raw one. A dose dependent decrease in soluble proteins and available lysine in the three legumes were observed. The non-enzymatic browning reaction was significantly increased with increasing the radiation dose, which was proved by changes in browning index tests. At the same time, the in vitro protein digestibility was increased after irradiation up to 60 kGy. Irradiation of dried peas with 60 kGy produced higher browning index than the other legumes. A positive correlation was observed between the radiation dose and the browning index for soybeans (R2= 0.96), broad beans (R2 = 0.81) and dried peas (R2 = 0.97) which means that 96%, 81% and 97 of the variation in the incidence of non-enzymatic browning reaction in soybean, broad bean and dried peas, respectively, are due to the effect of irradiation treatments. The present study suggests that the formation of non-enzymatic browning reaction did not impair the nutritional quality of legumes, therefore, the process of irradiation was helpful in increasing the in vitro protein digestibility of studied legumes. These results clearly indicated that gamma irradiation processing at the studied doses can add valuable effects to the studied legumes

  2. The browning kinetics of the non-enzymatic browning reaction in L-ascorbic acid/basic amino acid systems

    Directory of Open Access Journals (Sweden)

    Ai-Nong YU

    Full Text Available Abstract Under the conditions of weak basis and the reaction temperature range of 110-150 °C, lysine, arginine and histidine were reacted with L-ascorbic acid at equal amount for 30-150 min, respectively and the formation of browning products was monitored with UV–vis spectrometry. The kinetic characteristics of their non-enzymatic browning reaction were investigated. The study results indicated that the non-enzymatic browning reaction of these three amino acids with L-ascorbic acid to form browning products was zero-order reaction. The apparent activation energies for the formation of browning products from L-ascorbic acid/lysine, L-ascorbic acid/arginine and L-ascorbic acid/histidine systems were 54.94, 50.08 and 35.31kJ/mol. The activation energy data indicated the degree of effects of reaction temperature on non-enzymatic browning reaction. Within the temperature range of 110-150 °C, the reaction rate of L-ascorbic acid/lysine system was the fastest one, followed by that of the L-ascorbic acid/arginine system. The reaction rate of L-ascorbic acid/histidine system was the slowest one. Based on the observed kinetic data, the formation mechanisms of browning products were proposed.

  3. The effect of irradiation temperature on the non-enzymatic browning reaction in cooked rice

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ju-Woon [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of); Oh, Sang-Hee [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of); Kim, Jae-Hun [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of); Byun, Eui-Hong [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of); Ree Kim, Mee [Department of Food and Nutrition, Chungnam National University, Gung-Dong 220, Yuseong, Daejeon 305-764 (Korea, Republic of); Baek, Min [Atomic Energy Policy Division, Ministry of Science and Technology, Government Complex-Gwacheon, Kyunggi 427-715 (Korea, Republic of); Byun, Myung-Woo [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of)]. E-mail: mwbyun@kaeri.re.kr

    2007-05-15

    The effect of irradiation temperature on the non-enzymatic browning reaction in a sugar-glycine solution and cooked rice generated by gamma irradiation was evaluated in the present study. When the sugar-glycine solution and cooked rice were irradiated at room temperature, the browning reaction was dramatically increased during the post-irradiation period. In the case of irradiation at below the freezing point, the browning by irradiation was retarded during not only irradiation but also a post-irradiation period. The changes of the sugar profile, such as a sugar loss or reducing power of the irradiated sugar-glycine solution and the electron spin resonance signal intensity of the irradiated cooked rice were also decreased with lower irradiation temperature. The present results may suggest that the production of free radicals and a radiolysis product is inhibited during gamma irradiation in the frozen state and it may prevent the browning reaction generated by gamma irradiation from occurring.

  4. Investigation of lipid oxidation and non-enzymatic browning reactions in marine PL emulsions

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.

    Marine phospholipids (PL) have received much attention recently due to their numerous advantages. One of these advantages is their better resistance towards oxidation as compared to fish oil. In addition to the antioxidative properties of α-tocopherol and phospholipids, the better oxidative...... stability of marine PL might be attributed to antioxidative properties of pyrroles formed between oxidised lipids with amine groups from phosphatidylethanolamine (PE) or residues amino acids that are present in marine PL. The main objective of this study was to investigate if the presence of amine group...... from PE or amino acids affected the oxidative stability of purified marine PL emulsions. The secondary objective was to study the non-enzymatic browning reactions in the emulsions which included both Strecker degradation (SD) and pyrroles formation. Emulsions were prepared with and without addition...

  5. Effect of temperature towards lipid oxidation and non-enzymatic browning reactions in krill oil upon storage

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Bruheim, I.; Haugsgjerd, B.O.

    2014-01-01

    was assessed by peroxide value and anisidine value, measurement of lipid derived volatiles, lipid classes and antioxidants. The non-enzymatic browning reactions were assessed through the measurement of pyrroles, free amino acids content and Strecker-derived volatiles. The increase of incubation temperature...

  6. Influence of l-pyroglutamic acid on the color formation process of non-enzymatic browning reactions.

    Science.gov (United States)

    Wegener, Steffen; Kaufmann, Martin; Kroh, Lothar W

    2017-10-01

    Heating aqueous d-glucose model reactions with l-glutamine and l-alanine yielded similar colored solutions. However, size-exclusion chromatography (SEC) revealed that both non-enzymatic browning reactions proceeded differently. Due to a fast occurring cyclization of l-glutamine to pyroglutamic acid, the typical amino-carbonyl reaction was slowed down. However, l-glutamine and l-alanine model reactions showed the same browning index. Closer investigations could prove that l-pyroglutamic acid was able to influence non-enzymatic browning reactions. SEC analyses of d-glucose model reactions with and without l-pyroglutamic acid revealed an increase of low molecular colored compounds in the presence of l-pyroglutamic acid. Polarimetric measurements showed a doubling of d-glucose mutarotation velocity and HPLC analyses of d-fructose formation during thermal treatment indicated a tripling of aldose-ketose transformation in the presence of l-pyroglutamic acid, which are signs of a faster proceeding non-enzymatic browning process. 2-Pyrrolidone showed no such behavior, thus the additional carboxylic group should be responsible for the observed effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Technical Report for a Study on the Mechanism and Control of Non-Enzymatic Browning Reaction in Gamma-Irradiated Food

    International Nuclear Information System (INIS)

    Byun, Myung Woo; Lee, Ju Woon; Kim, Jae Hun

    2007-01-01

    Gamma irradiation leads to a non-enzymatic browning reaction (carbonyl -amine reaction) in an aqueous system similar to those induced in a heated one. This reaction may influence the changes of the color in irradiated foods. The intensity of the reaction was dependent on the type of the sugar, if the occurrence is by irradiation or by heating. There was a difference in the browning reaction between irradiation and heating. Although no browning was observed in the heated solution of the non-reducing sugar, the formation of colored products was observed in the irradiated sucrose-lysine solution. It could be explained on the basis that irradiation promotes the breakdown of the glycosidic linkages of the disaccharide, sucrose and the produce of a reducing power. The high molecular weight melanoidin (> MW 12,000-14,000 Da) was produced by gamma irradiation from the non-enzymatic browning reaction between glucose and glycine. The structure of melanoidin was similar to melanodin from heat processing. The results suggested that gamma-irradiation occurred the non-enzymatic browning reaction that is similar the reaction by heat processing. Non-enzymatic browning reaction during gamma-irradiation processing was greatly influenced by pH and medium of reaction system. The brown color development of irradiated sugar solutions with and without glycine is more increased in buffer system especially with alkaline pH than DDW. When food is irradiated, off-color such as browning can be produced due to the non-enzymatic browning reaction and it is influenced by other ions and/or pH of system. This suggests that the browning of irradiated food might be retarded by lowering the pH of the system. Gamma-irradiation produce the free radical and the radiolysis products of sugar and glycine and then they may be condensed to colored products during post-irradiation. However, when the food is irradiated in frozen state, the production of free radical and radiolysis product is inhibited and it

  8. Technical Report for a Study on the Mechanism and Control of Non-Enzymatic Browning Reaction in Gamma-Irradiated Food

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Myung Woo; Lee, Ju Woon; Kim, Jae Hun

    2007-01-15

    Gamma irradiation leads to a non-enzymatic browning reaction (carbonyl -amine reaction) in an aqueous system similar to those induced in a heated one. This reaction may influence the changes of the color in irradiated foods. The intensity of the reaction was dependent on the type of the sugar, if the occurrence is by irradiation or by heating. There was a difference in the browning reaction between irradiation and heating. Although no browning was observed in the heated solution of the non-reducing sugar, the formation of colored products was observed in the irradiated sucrose-lysine solution. It could be explained on the basis that irradiation promotes the breakdown of the glycosidic linkages of the disaccharide, sucrose and the produce of a reducing power. The high molecular weight melanoidin (> MW 12,000-14,000 Da) was produced by gamma irradiation from the non-enzymatic browning reaction between glucose and glycine. The structure of melanoidin was similar to melanodin from heat processing. The results suggested that gamma-irradiation occurred the non-enzymatic browning reaction that is similar the reaction by heat processing. Non-enzymatic browning reaction during gamma-irradiation processing was greatly influenced by pH and medium of reaction system. The brown color development of irradiated sugar solutions with and without glycine is more increased in buffer system especially with alkaline pH than DDW. When food is irradiated, off-color such as browning can be produced due to the non-enzymatic browning reaction and it is influenced by other ions and/or pH of system. This suggests that the browning of irradiated food might be retarded by lowering the pH of the system. Gamma-irradiation produce the free radical and the radiolysis products of sugar and glycine and then they may be condensed to colored products during post-irradiation. However, when the food is irradiated in frozen state, the production of free radical and radiolysis product is inhibited and it

  9. New parameters for evaluating the quality of commercial krill oil capsules from the aspect of lipid oxidation and non-enzymatic browning reactions

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Bruheim, Inge; Jacobsen, Charlotte

    2015-01-01

    , and their alkyl derivatives, sulphur and amino compounds). The data of chemical composition of krill oil were correlated well with those from volatile measurement. Through investigating volatile profile, new insights into the lipid oxidation and non-enzymatic browning reactions in krill oil were obtained...... different commercial krill oil capsules through parameters such as: investigation of chemical compositions (bioactive compounds such as phospholipids, n-3 polyunsaturated fatty acids, antioxidants), hydrophobic pyrroles, and volatile profiles (lipid and Strecker-derived volatiles, pyridines, pyrazines...... provides new parameters to differentiate the quality of krill oil through the measurement of bioactive compounds and hydrophobic pyrroles in krill oil, and investigation of volatile profiles of krill oil from the aspect of lipid oxidation and non-enzymatic browning reactions....

  10. Non-Enzymatic-Browning-Reaction: A Versatile Route for Production of Nitrogen-Doped Carbon Dots with Tunable Multicolor Luminescent Display

    Science.gov (United States)

    Wei, Weili; Xu, Can; Wu, Li; Wang, Jiasi; Ren, Jinsong; Qu, Xiaogang

    2014-01-01

    The non-enzymatic browning, namely Maillard reaction is commonly invoked to account for abiotic chemical transformations of organic matter. Here we report a new reaction pathway via the Maillard reaction to systematically synthesize a series of nitrogen-doped carbon dots (C-dots) with superhigh quantum yield (QY) and tunable multicolor luminescent displayment. The starting materials are glucose and the serial amino acid analogues which allow systemically controlling luminescent and physicochemical properties of C-dots at will. Unexpectedly, the as-prepared C-dots possess bright photoluminescence with QY up to 69.1% which is almost the highest ever reported, favorable biocompatibility, excellent aqueous and nonaqueous dispersibility, ultrahigh photostability, and readily functionalization. We have demonstrated that they are particularly suitable for multicolor luminescent display and long-term and real-time cellular imaging. Furthermore, the methodology is readily scalable to large yield, and can provide sufficient amount of C-dots for practical demands.

  11. Non-enzymatic browning reaction of glucosamine at mild conditions: Relationship between colour formation, radical scavenging activity and α-dicarbonyl compounds production.

    Science.gov (United States)

    Hong, Pui Khoon; Betti, Mirko

    2016-12-01

    Glucosamine (GlcN, 5% w/v) was incubated in either phosphate buffer or ammonium hydroxide solutions at 40 and 60°C for up to 48h in order to yield caramel solutions. Non-enzymatic browning was monitored via changes in absorption at 280, 320 and 420nm and the physico-chemical properties as well as the generation of short chain α-dicarbonyl compounds were evaluated. Accumulation of GlcN autocondensation products (280nm) proceeded in parallel with the development of pre-melanoidins (320nm) and melanoidins (420nm). The reactive α-dicarbonyls were detected at temperature as low as 40°C within 3h with a maximum level of diacetyl recorded at 6h. The caramel solutions showed a high efficacy in scavenging DPPH and ABTS radicals in accordance with the increasing browning intensity. The results suggest that GlcN browning can be modulated according to the specific desired properties to produce a multi-functional food ingredient that has health-promoting effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Kinetic modelling of non-enzymatic browning and changes of physio-chemical parameters of peach juice during storage.

    Science.gov (United States)

    Lyu, Jian; Liu, Xuan; Bi, Jinfeng; Wu, Xinye; Zhou, Linyan; Ruan, Weihong; Zhou, Mo; Jiao, Yi

    2018-03-01

    Kinetics of non-enzymatic browning and loss of free amino acids during different storage temperature (4, 25, 37 °C) were investigated. Changes of browning degree ( A 420 ), color parameters, Vitamin C ( V c ), free amino acids and 5-hydroxymethylfurfural (5-HMF) were analyzed to evaluate the non-enzymatic browning reactions, which were significantly affected by storage temperature. The lower temperature (4 °C) decreased the loss of V c and the generation of 5-HMF, but induce the highest loss of serine. At the end of storage, loss of serine, alanine and aspartic acid were mainly lost. Results showed that zero-order kinetic model ( R 2  > 0.859), the first-order model ( R 2  > 0.926) and the combined kinetic model ( R 2  > 0.916) were the most appropriate to describe the changes of a * and b * values, the degradation of V c and the changes of A 420 , L * and 5-HMF during different storage temperatures. These kinetic models can be applied for predicting and minimizing the non-enzymatic browning of fresh peach juice during storage.

  13. Impact of primary amine group from aminophospholipids and amino acids on marine phospholipids stability: Non-enzymatic browning and lipid oxidation

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.

    2013-01-01

    The main objective of this study was to investigate the oxidative stability and non-enzymatic browning reactions of marine PL in the presence or in the absence of primary amine group from aminophospholipids and amino acids. Marine phospholipids liposomal dispersions were prepared from two authent...... the formation of pyrroles, generated Strecker derived volatiles, decreased the YI development and lowered lipid oxidation. The lower degree of lipid oxidation in liposomal dispersions containing amino acids might be attributed to antioxidative properties of pyrroles or amino acids....

  14. Oxidative degradation and non-enzymatic browning due to the interaction between oxidised lipids and primary amine groups in different marine PL emulsions

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.

    2012-01-01

    levels of triglycerides in the emulsions. The oxidative and hydrolytic stability of emulsions was investigated through measurement of peroxide value, free fatty acids, and 31P NMR during storage at 2 C for up to 32 days. The oxidative stability of marine PL emulsions during storage was further......Due to the beneficial health effects of marine phospholipids (PL) there is an increasing industrial interest in using them for nutritional applications including emulsified foods. This study was undertaken to investigate both oxidative and hydrolytic stability of marine PL emulsions in relation...... investigated through the measurement of secondary volatile compounds by solid-phase microextraction (SPME) and dynamic headspace (DHS) connected to gas chromatography (GC–MS). Non-enzymatic browning reactions were investigated through the measurement of Strecker derived volatiles, colour changes and pyrrole...

  15. Non-enzymatic browning due to storage is reduced by using clarified lemon juice as acidifier in industrial-scale production of canned peach halves.

    Science.gov (United States)

    Saura, Domingo; Vegara, Salud; Martí, Nuria; Valero, Manuel; Laencina, José

    2017-06-01

    Non-enzymatic browning (NEB) in canned peach halves in syrup during storage was investigated. Absorbance at 420 nm ( A 420 ), colorimetric parameters (CIE Lab , TCD and La / b ), fructose, glucose and sucrose, total sugar, organic acids, ascorbic acid (AA), dehydroascorbic acid, and 2,3-diketogulonic acid were used to estimate the extent of NEB during 1 year of storage at 30 °C and the relationships between each of these parameters and A 420 were established. The investigation was carried out to explore the possibility of replacing the E330 commonly used as acidifier by turbid or clarified lemon juice (TLJ or CLJ) to obtain a product having good nutrition with better retention of quality. The a , La / b , glucose and fructose were positively correlated with A 420 and all proved to be good indicators of browning development. Overall results showed that replacement of acidifier E330 with CLJ for controlling pH in canned peach halves in syrup had some advantages.

  16. Effect of formulation and baking conditions on the structure and development of non-enzymatic browning in biscuit models using images.

    Science.gov (United States)

    Leiva-Valenzuela, Gabriel A; Quilaqueo, Marcela; Lagos, Daniela; Estay, Danilo; Pedreschi, Franco

    2018-04-01

    The aim of this research was to determine the effect of composition (dietary fiber = DF, fat = F, and gluten = G) and baking time on the target microstructural parameters that were observed using images of potato and wheat starch biscuits. Microstructures were studied Scanning Electron Microscope (SEM). Non-enzymatic browning (NEB) was assessed using color image analysis. Texture and moisture analysis was performed to have a better understanding of the baking process. Analysis of images revealed that the starch granules retained their native form at the end of baking, suggesting their in complete gelatinization. Granules size was similar at several different baking times, with an average equivalent diameter of 9 and 27 µm for wheat and potato starch, respectively. However, samples with different levels of DF and G increased circularity during baking to more than 30%, and also increasing hardness. NEB developed during baking, with the maximum increase observed between 13 and 19 min. This was reflected in decreased luminosity (L*) values due to a decrease in moisture levels. After 19 min, luminosity did not vary significantly. The ingredients that are used, as well as their quantities, can affect sample L* values. Therefore, choosing the correct ingredients and quantities can lead to different microstructures in the biscuits, with varying amounts of NEB products.

  17. Oxidative stability and non-enzymatic browning reactions in Antarctic krill oil (Euphausia superba)

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Bruheim, Inge; Jacobsen, Charlotte

    2014-01-01

    Antarctic krill oil has gained much consideration recently due to its rich content of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the form of phospholipids and its powerful antioxidant known as astaxanthin. To secure these valuable bioactive nutrients in krill oil, a gentle...

  18. Bimolecular interaction of argpyrimidine (a Maillard reaction product) in in vitro non-enzymatic protein glycation model and its potential role as an antiglycating agent.

    Science.gov (United States)

    Bhattacherjee, Abhishek; Dhara, Kaliprasanna; Chakraborti, Abhay Sankar

    2017-09-01

    Non- enzymatic glycation, also known as Maillard reaction, is one of the most important and investigated reactions in biochemistry. Maillard reaction products (MRPs) like protein-derived advanced glycation end products (AGEs) are often referred to cause pathophysiological complications in human systems. On contrary, several MRPs are exogenously used as antioxidant, antimicrobial and flavouring agents. In the preset study, we have shown that argpyrimidine, a well-established AGE, interacts with bovine serum albumin (BSA) and glucose individually in standard BSA-glucose model system and successfully inhibits glycation of the protein. Bimolecular interaction of argpyrimidine with glucose or BSA has been studied independently. Chromatographic purification, different spectroscopic studies and molecular modeling have been used to evaluate the nature and pattern of interactions. Binding of argpyrimidine with BSA prevents incorporation of glucose inside the native protein. Argpyrimidine can also directly entrap glucose. Both these interactions may be associated with the antiglycation potential of argpyrimidine, indicating a beneficial function of an AGE. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Non-enzymatic detection of hydrogen peroxide based on Fenton-type reaction on poly(azure A)-chitosan/Cu modified electrode

    International Nuclear Information System (INIS)

    Liu, Tong; Luo, Yiqun; Wang, Wen; Kong, Liyan; Zhu, Jiaming; Tan, Liang

    2015-01-01

    Highlights: • The PAA-CS modified GCE was prepared using cyclic voltammetry. • Copper ions were strongly bound to the PAA-CS composites by complexation. • ·OH derived from the reaction between Cu 2+ and H 2 O 2 effectively oxidized PAA. • An electrochemical sensor of H 2 O 2 with good analytical performance was developed. - Abstract: In this work, a sensitive electrochemical method for the detection of H 2 O 2 was proposed based on Fenton-type reaction on the electrode surface. A glassy carbon electrode modified with poly(azure A) (PAA), chitosan (CS) and copper ions, displaying a good electrochemical activity, was fabricated by cyclic voltammetry and the adsorption of Cu 2+ . Scanning electron microscopy-Energy dispersive spectroscopy analysis, infrared and Raman spectral characterization and XPS measurement showed the stable complexation of Cu 2+ with the PAA-CS film. Hydroxyl radicals derived from the Fenton-type reaction between Cu 2+ and H 2 O 2 could effectively oxidize poly(azure A), leading to the great reduction-current change of the dye polymer in the electrode process. Under the optimized conditions, the fabricated electrode displayed a linear response in the H 2 O 2 concentration range from 0.002 to 0.5 mM and that from 2.56 to 25.0 mM with a detection limit of 0.7 μM estimated at a signal-to-noise ratio of 3. The good analytical performance including low detection limit, fast response time, low cost, good anti-interference performance, satisfying stability, acceptable repeatability and reliable reproducibility were found from the proposed amperometric sensor, suggesting that the current work could provide a feasible approach for the non-enzymatic H 2 O 2 detection.

  20. Modeling the kinetics nonenzymatic browning reactions and rheological behavior in the termal process of fruit juices and pulps

    Directory of Open Access Journals (Sweden)

    Damian Manayay

    2010-06-01

    Full Text Available In the manufacture of fruit juices and pulps, is of paramount importance to refer to non-enzymatic browning and rheological behavior. The non-enzymatic browning is a phenomenon of darkening of a purely chemical (Braverman, 1980, is characterized by the presence of brown polymers called melanoidins, generated by the Maillard reaction or condensation of melanoidins, the caramelization and degradation of acid ascorbic, while the rheological behavior is define as the proportion deformation of the material when exposed to shear stress (σ caused by a rheometer (Muller, 1978; Ibarz, 2005. Modeling studies of colour formation and definition of rheological behavior, considered in this review, aimed at the conclusion of the existence of a zero kinetic and first order respectively, and the most influential factors with the reactions are mainly Maillard, temperature, amino acids presence, water activity and pH, while the rheological behavior is affected by temperature, solid concentration and particles size that make up the suspension in the specific case of the pulps.

  1. Sulfate radicals enable a non-enzymatic Krebs cycle precursor.

    Science.gov (United States)

    Keller, Markus A; Kampjut, Domen; Harrison, Stuart A; Ralser, Markus

    2017-03-13

    The evolutionary origins of the tricarboxylic acid cycle (TCA), or Krebs cycle, are so far unclear. Despite a few years ago, the existence of a simple non-enzymatic Krebs-cycle catalyst has been dismissed 'as an appeal to magic', citrate and other intermediates have meanwhile been discovered on a carbonaceous meteorite and do interconvert non-enzymatically. To identify the non-enzymatic Krebs cycle catalyst, we used combinatorial, quantitative high-throughput metabolomics to systematically screen iron and sulfate reaction milieus that orient on Archean sediment constituents. TCA cycle intermediates are found stable in water and in the presence of most iron and sulfate species, including simple iron-sulfate minerals. However, we report that TCA intermediates undergo 24 interconversion reactions in the presence of sulfate radicals that form from peroxydisulfate. The non-enzymatic reactions critically cover a topology as present in the Krebs cycle, the glyoxylate shunt and the succinic semialdehyde pathways. Assembled in a chemical network, the reactions achieve more than ninety percent carbon recovery. Our results show that a non-enzymatic precursor for the Krebs cycle is biologically sensible, efficient, and forms spontaneously in the presence of sulfate radicals.

  2. Changes in the physicochemical characteristics, including flavour components and Maillard reaction products, of non-centrifugal cane brown sugar during storage.

    Science.gov (United States)

    Asikin, Yonathan; Kamiya, Asahiro; Mizu, Masami; Takara, Kensaku; Tamaki, Hajime; Wada, Koji

    2014-04-15

    Changes in the quality attributes of non-centrifugal cane brown sugar represented by physicochemical characteristics as well as flavour components and Maillard reaction products (MRPs) were monitored every 3 months over 1 year of storage. Stored cane brown sugar became darker, and its moisture content and water activity (a(w)) increased during storage. Fructose and glucose levels decreased as non-enzymatic browning via the Maillard reaction occurred in the stored sample, and a similar trend was also discovered in aconitic and acetic acids. Stored cane brown sugar lost its acidic and sulfuric odours (58.70-39.35% and 1.85-0.08%, respectively); subsequently, the nutty and roasted aroma increased from 26.52% to 38.59% due to the volatile MRPs. The browning rate of stored cane brown sugar was positively associated with the development of volatile MRPs (Pearson's coefficient = 0.860), whereas the amount of 3-deoxyglucosone, an intermediate product of the Maillard reaction, had a lower association with the brown colour due to its relatively slow degradation rate. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Induction of mitotic gene conversion by browning reaction products and its modulation by naturally occurring agents.

    Science.gov (United States)

    Rosin, M P; Stich, H F; Powrie, W D; Wu, C H

    1982-05-01

    Mitotic gene conversion in the D7 strain of Saccharomyces cerevisiae was significantly enhanced by exposure to non-enzymatic browning reaction products. These products were formed during the heating of sugar (caramelization reaction) or sugar-amino acid mixtures (Maillard reaction) at temperatures normally used during the cooking of food. Several modulating factors of this convertogenic activity were identified. These factors included two main groups: (1) trace metals which are widely distributed in the environment; and (2) several cellular enzymatic systems. The convertogenic activities of a heated glucose-lysine mixture and a commercial caramel powder were completely suppresses when yeast were concurrently exposed to these products and to either FeIII or CuII. Equimolar concentrations of MnII or sodium selenite had no effect on the convertogenic activity of the products of either model system. Horse-radish peroxidase, beef liver catalase and rat liver S9 preparations each decreased the frequency of gene conversion induced by the caramel powder and the heated glucose-lysine products. This modulating activity of the enzymes was lost if they were heat-inactivated. These studies indicate the presence of a variety of protective mechanisms which can modify genotoxic components in complex food mixtures.

  4. Electrochemical non-enzymatic glucose sensors

    International Nuclear Information System (INIS)

    Park, Sejin; Boo, Hankil; Chung, Taek Dong

    2006-01-01

    The electrochemical determination of glucose concentration without using enzyme is one of the dreams that many researchers have been trying to make come true. As new materials have been reported and more knowledge on detailed mechanism of glucose oxidation has been unveiled, the non-enzymatic glucose sensor keeps coming closer to practical applications. Recent reports strongly imply that this progress will be accelerated in 'nanoera'. This article reviews the history of unraveling the mechanism of direct electrochemical oxidation of glucose and making attempts to develop successful electrochemical glucose sensors. The electrochemical oxidation of glucose molecules involves complex processes of adsorption, electron transfer, and subsequent chemical rearrangement, which are combined with the surface reactions on the metal surfaces. The information about the direct oxidation of glucose on solid-state surfaces as well as new electrode materials will lead us to possible breakthroughs in designing the enzymeless glucose sensing devices that realize innovative and powerful detection. An example of those is to introduce nanoporous platinum as an electrode, on which glucose is oxidized electrochemically with remarkable sensitivity and selectivity. Better model of such glucose sensors is sought by summarizing and revisiting the previous reports on the electrochemistry of glucose itself and new electrode materials

  5. Non-enzymatic depolymerization of cotton cellulose by fungal mimicking metabolites

    Science.gov (United States)

    Anne Christine Steenkjaer Hastrup; Caitlin Howell; Bo Jensen; Frederick Green

    2011-01-01

    Small, low molecular weight, non-enzymatic compounds have been linked to the early stages of brown rot decay as the enzymes involved with holocellulose degradation are too large to penetrate the S3 layer of intact wood cells. We investigated the most notable of these compounds, i.e. hydrogen peroxide, iron, and oxalic acid. The former two are involved in the Fenton...

  6. Physico-chemical properties, oxidative stability and non-enzymatic browning reactions in marine phospholipids emulsions and their applications for food enrichment

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.

    Marine phospholipids (PL) are more advantageous than fish oil. They seem to have better bioavailability, better resistance and higher content of eicosapentaenoic acids and docosahexaenoic acids than fish oil. The main objective of this study was to explore the possibilities of using marine PL...

  7. Possibility of the Nonenzymatic Browning (Maillard) Reaction in the ISM

    Science.gov (United States)

    Jalbout, Abraham F.; Shipar, M. Abul Haider

    2008-04-01

    The possibility of the occurrence of the nonenzymatic browning reaction in the gaseous phase in the interstellar medium has been investigated by using Density Functional Theory computations. Mechanisms for the reactions between formaldehyde ( Fald) + glycine ( Gly), Fald + NH 3 and Fald + methylamine ( MeAm) have been proposed, and the possibility of the formation of different compounds in the proposed mechanisms has been evaluated through calculating the Gibb's free energy changes for different steps of the reaction, by following the total mass balance. The Fald + Gly reaction under basic conditions is found as the most favorable for producing 1-methyl-amino methene or 1-methyl-amino methelene ( MAM). The reaction under acidic conditions is found to be the least favorable for producing MAM. The Fald + NH 3 reaction is found to be plausible for the production of MeAm, which can participate by reaction with Fald, resulting in the formation of MAM.

  8. Browning reaction systems as sources of mutagens and antimutagens.

    OpenAIRE

    Powrie, W D; Wu, C H; Molund, V P

    1986-01-01

    Heated food systems contain hundreds of chemical compounds, some being mutagenic and others being antimutagenic. Studies have indicated that foods exposed to drying, frying, roasting, baking, and broiling conditions possess net mutagenic activity as assessed by the Ames/Salmonella/microsome mutagenicity test and the chromosome aberration assay with Chinese hamster ovary (CHO) cells. With the above-mentioned heat treatment of food, nonenzymic browning reactions are generally proceeding at rapi...

  9. Browning reaction systems as sources of mutagens and antimutagens.

    Science.gov (United States)

    Powrie, W D; Wu, C H; Molund, V P

    1986-08-01

    Heated food systems contain hundreds of chemical compounds, some being mutagenic and others being antimutagenic. Studies have indicated that foods exposed to drying, frying, roasting, baking, and broiling conditions possess net mutagenic activity as assessed by the Ames/Salmonella/microsome mutagenicity test and the chromosome aberration assay with Chinese hamster ovary (CHO) cells. With the above-mentioned heat treatment of food, nonenzymic browning reactions are generally proceeding at rapid rates and are involved in the development of mutagens. Caramelization and Maillard reactions are two important pathways in the nonenzymic browning of food and are responsible for the formation of volatile aromatic compounds, intermediate nonvolatile compounds, and brown pigments called melanoidins. Heated sugar-amino acid mixtures possessed mutagenic activities which have been assessed by short-term bioassays. Purified Maillard and caramelization reaction products such as reductones, dicarbonyls, pyrazines, and furan derivatives have exhibited mutagenicity and clastogenicity. The water-insoluble fraction (WIF) of instant coffee and a model-system melanoidin (MSM) have been shown to inhibit the mutagenicity of known carcinogens--aflatoxin B1 (AFB1), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), and benzo(a)pyrene (BP)--in aqueous dispersion. WIF and MSM were found to be effective binding agents for the carcinogens.

  10. Ketone Body Acetoacetate Buffers Methylglyoxal via a Non-enzymatic Conversion during Diabetic and Dietary Ketosis

    DEFF Research Database (Denmark)

    Salomon, Trine; Sibbersen, Christian; Hansen, Jakob

    2017-01-01

    now demonstrate that during ketosis, another meta- bolic route is operative via direct non-enzymatic aldol reaction between methylglyoxal and the ke- tone body acetoacetate, leading to 3-hydroxyhex- ane-2,5-dione. This novel metabolite is present at a concentration of 10%–20% of the methylglyoxal...

  11. Brown carbon formation by aqueous-phase carbonyl compound reactions with amines and ammonium sulfate.

    Science.gov (United States)

    Powelson, Michelle H; Espelien, Brenna M; Hawkins, Lelia N; Galloway, Melissa M; De Haan, David O

    2014-01-21

    Reactions between small water-soluble carbonyl compounds, ammonium sulfate (AS), and/or amines were evaluated for their ability to form light-absorbing species in aqueous aerosol. Aerosol chemistry was simulated with bulk phase reactions at pH 4, 275 K, initial concentrations of 0.05 to 0.25 M, and UV-vis and fluorescence spectroscopy monitoring. Glycolaldehyde-glycine mixtures produced the most intense absorbance. In carbonyl compound reactions with AS, methylamine, or AS/glycine mixtures, product absorbance followed the order methylglyoxal > glyoxal > glycolaldehyde > hydroxyacetone. Absorbance extended into the visible, with a wavelength dependence fit by absorption Ångstrom coefficients (Å(abs)) of 2 to 11, overlapping the Å(abs) range of atmospheric, water-soluble brown carbon. Many reaction products absorbing between 300 and 400 nm were strongly fluorescent. On a per mole basis, amines are much more effective than AS at producing brown carbon. In addition, methylglyoxal and glyoxal produced more light-absorbing products in reactions with a 5:1 AS-glycine mixture than with AS or glycine alone, illustrating the importance of both organic and inorganic nitrogen in brown carbon formation. Through comparison to biomass burning aerosol, we place an upper limit on the contribution of these aqueous carbonyl-AS-amine reactions of ≤ 10% of global light absorption by brown carbon.

  12. Nonenzymatic browning reaction of essential amino acids: effect of pH on caramelization and Maillard reaction kinetics.

    Science.gov (United States)

    Ajandouz, E H; Puigserver, A

    1999-05-01

    The interaction between glucose and essential amino acids at 100 degrees C at pH values ranging from 4.0 to 12.0 was investigated by monitoring the disappearance of glucose and amino acids as well as the appearance of brown color. Lysine was the most strongly destroyed amino acid, followed by threonine which induced very little additional browning as compared with that undergone by glucose. Around neutrality, the nonenzymatic browning followed pseudo-zero-order kinetics after a lag time, while the glucose and amino acid losses did not follow first-order kinetics at any of the pH values tested. Glucose was more strongly destroyed than all of the essential amino acids, the losses of which are really small at pH values lower than 9.0. However, glucose was less susceptible to thermal degradation in the presence of amino acids, especially at pH 8.0 with threonine and at pH 10.0 with lysine. The contribution of the caramelization reaction to the overall nonenzymatic browning above neutrality should lead to an overestimation of the Maillard reaction in foods.

  13. Comparison of the role that entropy has played in processes of non-enzymatic and enzymatic catalysis

    International Nuclear Information System (INIS)

    Dixon Pineda, Manuel Tomas

    2012-01-01

    The function that entropy has played is compared in processes of non-enzymatic and enzymatic catalysis. The processes followed are showed: the kinetics of the acid hydrolysis of 3-pentyl acetate and cyclopentyl acetate catalyzed by hydrochloric acid and enzymatic hydrolysis of ethyl acetate and γ-butyrolactone catalyzed by pig liver esterase. The activation parameters of Eyring were determined for each process and interpreted the contribution of the entropy of activation for catalysis in this type of model reactions. (author) [es

  14. Enzymatic and non-enzymatic detoxification of 4-hydroxynonenal: Methodological aspects and biological consequences.

    Science.gov (United States)

    Mol, Marco; Regazzoni, Luca; Altomare, Alessandra; Degani, Genny; Carini, Marina; Vistoli, Giulio; Aldini, Giancarlo

    2017-10-01

    4-Hydroxynonenal (HNE), an electrophilic end-product deriving from lipid peroxidation, undergoes a heterogeneous set of biotransformations including enzymatic and non-enzymatic reactions. The former mostly involve red-ox reactions on the HNE oxygenated functions (phase I metabolism) and GSH conjugations (phase II) while the latter are due to the HNE capacity to spontaneously condense with nucleophilic sites within endogenous molecules such as proteins, nucleic acids and phospholipids. The overall metabolic fate of HNE has recently attracted great interest not only because it clearly determines the HNE disposal, but especially because the generated metabolites and adducts are not inactive molecules (as initially believed) but show biological activities even more pronounced than those of the parent compound as exemplified by potent pro-inflammatory stimulus induced by GSH conjugates. Similarly, several studies revealed that the non-enzymatic reactions, initially considered as damaging processes randomly involving all endogenous nucleophilic reactants, are in fact quite selective in terms of both reactivity of the nucleophilic sites and stability of the generated adducts. Even though many formed adducts retain the expected toxic consequences, some adducts exhibit well-defined beneficial roles as documented by the protective effects of sublethal concentrations of HNE against toxic concentrations of HNE. Clearly, future investigations are required to gain a more detailed understanding of the metabolic fate of HNE as well as to identify novel targets involved in the biological activity of the HNE metabolites. These studies are and will be permitted by the continuous progress in the analytical methods for the identification and quantitation of novel HNE metabolites as well as for proteomic analyses able to offer a comprehensive picture of the HNE-induced adducted targets. On these grounds, the present review will focus on the major enzymatic and non-enzymatic HNE

  15. Non-enzymatic glucose detection using magnetic nanoemulsions

    International Nuclear Information System (INIS)

    Mahendran, V.; Philip, John

    2014-01-01

    We probe the optical properties and intermolecular interactions in magnetically responsive nanoemulsions in the presence of glucose. The equilibrium interdroplet distance between the emulsion droplets in an one-dimensional array increases by several nanometers in the presence of glucose because of intermolecular hydrogen bonding with sodium dodecyl sulphate molecules at the oil-water interface that gives rise to stretched lamellae-like structure. The observed large red shift in the diffracted Bragg peak (∼50–100 nm) and the linear response in the glucose concentration range of 0.25–25 mM offer a simple, fast, and cost effective non-enzymatic approach for glucose detection.

  16. Non-enzymatic palladium recovery on microbial and synthetic surfaces.

    Science.gov (United States)

    Rotaru, Amelia-Elena; Jiang, Wei; Finster, Kai; Skrydstrup, Troels; Meyer, Rikke Louise

    2012-08-01

    The use of microorganisms as support for reduction of dissolved Pd(II) to immobilized Pd(0) nanoparticles is an environmentally friendly approach for Pd recovery from waste. To better understand and engineer Pd(0) nanoparticle synthesis, one has to consider the mechanisms by which Pd(II) is reduced on microbial surfaces. Escherichia coli, Shewanella oneidensis, and Pseudomonas putida were used as model organisms in order to elucidate the role of microbial cells in Pd(II) reduction under acidic conditions. Pd(II) was reduced by formate under acidic conditions, and the process occurred substantially faster in the presence of cells as compared to cell-free controls. We found no difference between native (untreated) and autoclaved cells, and could demonstrate that even a non-enzymatic protein (bovine serum albumin) stimulated Pd(II) reduction as efficiently as bacterial cells. Amine groups readily interact with Pd(II), and to specifically test their role in surface-assisted Pd(II) reduction by formate, we replaced bacterial cells with polystyrene microparticles functionalized with amine or carboxyl groups. Amine-functionalized microparticles had the same effect on Pd(II) reduction as bacterial cells, and the effect could be hampered if the amine groups were blocked by acetylation. The interaction with amine groups was confirmed by infrared spectroscopy on whole cells and amine-functionalized microparticles. In conclusion, bio-supported Pd(II) reduction on microbial surfaces is possibly mediated by a non-enzymatic mechanism. We therefore suggest the use of amine-rich biomaterials rather than intact cells for Pd bio-recovery from waste. Copyright © 2012 Wiley Periodicals, Inc.

  17. Application of Ni(II-assisted peptide bond hydrolysis to non-enzymatic affinity tag removal.

    Directory of Open Access Journals (Sweden)

    Edyta Kopera

    Full Text Available In this study, we demonstrate a non-enzymatic method for hydrolytic peptide bond cleavage, applied to the removal of an affinity tag from a recombinant fusion protein, SPI2-SRHWAP-His(6. This method is based on a highly specific Ni(II reaction with (S/TXHZ peptide sequences. It can be applied for the protein attached to an affinity column or to the unbound protein in solution. We studied the effect of pH, temperature and Ni(II concentration on the efficacy of cleavage and developed an analytical protocol, which provides active protein with a 90% yield and ∼100% purity. The method works well in the presence of non-ionic detergents, DTT and GuHCl, therefore providing a viable alternative for currently used techniques.

  18. On the Growth Rate of Non-Enzymatic Molecular Replicators

    Directory of Open Access Journals (Sweden)

    Harold Fellermann

    2011-10-01

    Full Text Available It is well known that non-enzymatic template directed molecular replicators X + nO -> 2X exhibit parabolic growth d[X]/dt -> k[X]1/2. Here, we analyze the dependence of the effective replication rate constant k on hybridization energies, temperature, strand length, and sequence composition. First we derive analytical criteria for the replication rate k based on simple thermodynamic arguments. Second we present a Brownian dynamics model for oligonucleotides that allows us to simulate their diffusion and hybridization behavior. The simulation is used to generate and analyze the effect of strand length, temperature, and to some extent sequence composition, on the hybridization rates and the resulting optimal overall rate constant k. Combining the two approaches allows us to semi-analytically depict a replication rate landscape for template directed replicators. The results indicate a clear replication advantage for longer strands at lower temperatures in the regime where the ligation rate is rate limiting. Further the results indicate the existence of an optimal replication rate at the boundary between the two regimes where the ligation rate and the dehybridization rates are rate limiting.

  19. Archetypal sandwich-structured CuO for high performance non-enzymatic sensing of glucose

    Science.gov (United States)

    Meher, Sumanta Kumar; Rao, G. Ranga

    2013-02-01

    In the quest to enhance the selectivity and sensitivity of novel structured metal oxides for electrochemical non-enzymatic sensing of glucose, we report here a green synthesis of unique sandwich-structured CuO on a large scale under microwave mediated homogeneous precipitation conditions. The physicochemical studies carried out by XRD and BET methods show that the monoclinic CuO formed via thermal decomposition of Cu2(OH)2CO3 possesses monomodal channel-type pores with largely improved surface area (~43 m2 g-1) and pore volume (0.163 cm3 g-1). The fascinating surface morphology and pore structure of CuO is formulated due to homogeneous crystallization and microwave induced self assembly during synthesis. The cyclic voltammetry and chronoamperometry studies show diffusion controlled glucose oxidation at ~0.6 V (vs. Ag/AgCl) with extremely high sensitivity of 5342.8 μA mM-1 cm-2 and respective detection limit and response time of ~1 μM and ~0.7 s, under a wide dynamic concentration range of glucose. The chronoamperometry measurements demonstrate that the sensitivity of CuO to glucose is unaffected by the absence of dissolved oxygen and presence of poisoning chloride ions in the reaction medium, which essentially implies high poison resistance activity of the sandwich-structured CuO. The sandwich-structured CuO also shows insignificant interference/significant selectivity to glucose, even in the presence of high concentrations of other sugars as well as reducing species. In addition, the sandwich-structured CuO shows excellent reproducibility (relative standard deviation of ~2.4% over ten identically fabricated electrodes) and outstanding long term stability (only ~1.3% loss in sensitivity over a period of one month) during non-enzymatic electrochemical sensing of glucose. The unique microstructure and suitable channel-type pore architecture provide structural stability and maximum accessible electroactive surface for unimpeded mobility of glucose as well as the

  20. Non-enzymatic U(VI) interactions with biogenic mackinawite

    Science.gov (United States)

    Veeramani, H.; Qafoku, N. P.; Kukkadapu, R. K.; Murayama, M.; Hochella, M. F.

    2011-12-01

    Reductive immobilization of hexavalent uranium [U(VI)] by stimulation of dissimilatory metal and/or sulfate reducing bacteria (DMRB or DSRB) has been extensively researched as a remediation strategy for subsurface U(VI) contamination. These bacteria derive energy by reducing oxidized metals as terminal electron acceptors, often utilizing organic substrates as electron donors. Thus, when evaluating the potential for in-situ uranium remediation in heterogeneous subsurface media, it is important to understand how the presence of alternative electron acceptors such as Fe(III) and sulfate affect U(VI) remediation and the long term behavior and reactivity of reduced uranium. Iron, an abundant subsurface element, represents a substantial sink for electrons from DMRB, and the reduction of Fe(III) leads to the formation of dissolved Fe(II) or to reactive biogenic Fe(II)- and mixed Fe(II)/Fe(III)- mineral phases. Consequently, abiotic U(VI) reduction by reactive forms of biogenic Fe(II) minerals could be a potentially important process for uranium immobilization. In our study, the DMRB Shewanella putrefaciens CN32 was used to synthesize a biogenic Fe(II)-bearing sulfide mineral: mackinawite, that has been characterized by XRD, SEM, HRTEM and Mössbauer spectroscopy. Batch experiments involving treated biogenic mackinawite and uranium (50:1 molar ratio) were carried out at room temperature under strict anoxic conditions. Following complete removal of uranium from solution, the biogenic mackinawite was analyzed by a suite of analytical techniques including XAS, HRTEM and Mössbauer spectroscopy to determine the speciation of uranium and investigate concomitant Fe(II)-phase transformation. Determining the speciation of uranium is critical to success of a remediation strategy. The present work elucidates non-enzymatic/abiotic molecular scale redox interactions between biogenic mackinawite and uranium.

  1. Monitoring the progress of non-enzymatic glycation in vitro

    International Nuclear Information System (INIS)

    Shaw, S.M.; Crabbe, M.J.

    1994-01-01

    The progress of in vitro non-enzymatic glycation of bovine serum albumin was followed by using 14 C-glucose and a nitroblue tetrazolium assay, absorption and fluorescence spectroscopy, SDS gel electrophoresis and protease digestion. The number of adducts detectable using both 14 C-tracers and a fructosamine assay remained low at physiological glucose concentrations, fewer than five adducts being detectable. When glucose concentrations > 1.0 M were used the number of adducts was found to greatly exceed the number of lysyl residues available in BSA, indicative of cross-linking between Maillard products. Incubation of BSA with glucose concentrations of up to 160 mM for one month produced no observable increase in molecular weight by SDS gel electrophoresis, showing that at physiological glucose concentrations, increases in molecular weight were minimal for short incubation periods. Increases in absorption were proportial to both the glucose concentration and the incubation time. Several absorption peaks, at 370, 488 and 554 nm, were consistent in appearance throughout the course of each incubation. Fluorescence spectroscopy of the modified proteins showed a disappearance of the fluorescence associated with peptide bonds and aromatic residues and the appearance of a broad peak at longer wavelengths due to the wide range of absorptive/fluorescent wavelengths of the developing Maillard products. Protease digestion gave similar patterns with non-glycated and glycated protein, suggesting that glycation did not block digestion sites, and that partial digestion did not cause significant further exposure of susceptible sites. Our results show that while glycation ultimately results in protein conformational changes and the formation of large molecular weight species, these occur at a relatively late stage in the maturation of protein Maillard products, after ≥ nine months of incubation with glucose concentration of ≥ 20 mM. Monitoring of AGE maturation in vitro is better

  2. The browning value changes and spectral analysis on the Maillard reaction product from glucose and methionine model system

    Science.gov (United States)

    Al-Baarri, A. N.; Legowo, A. M.; Widayat

    2018-01-01

    D-glucose has been understood to provide the various effect on the reactivity in Maillard reaction resulting in the changes in physical performance of food product. Therefore this research was done to analyse physical appearance of Maillard reaction product made of D-glucose and methionine as a model system. The changes in browning value and spectral analysis model system were determined. The glucose-methionine model system was produced through the heating treatment at 50°C and RH 70% for 24 hours. The data were collected for every three hour using spectrophotometer. As result, browning value was elevated with the increase of heating time and remarkably high if compare to the D-glucose only. Furthermore, the spectral analysis showed that methionine turned the pattern of peak appearance. As conclusion, methionine raised the browning value and changed the pattern of spectral analysis in Maillard reaction model system.

  3. Correlating enzymatic browning inhibition and antioxidant ability of Maillard reaction products derived from different amino acids.

    Science.gov (United States)

    Xu, Haining; Zhang, Xiaoming; Karangwa, Eric; Xia, Shuqin

    2017-09-01

    Up to now, only limited research on enzymatic browning inhibition capacity (BIC) of Maillard reaction products (MRPs) has been reported and there are still no overall and systematic researches on MRPs derived from different amino acids. In the present study, BIC and antioxidant capacity, including 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and Fe 2+ reducing power activity, of the MRPs derived from 12 different amino acids and three reducing sugars were investigated. The MRPs of cysteine (Cys), cystine, arginine (Arg) and histidine (His) showed higher BIC compared to other amino acids. Lysine (Lys)-MRPs showed the highest absorbance value at 420 nm (A 420 ) but very limited BIC, whereas Cys-MRPs, showed the highest BIC and the lowest A 420 . The A 420 can roughly reflect the trend of BIC of MRPs from different amino acids, except Cys and Lys. MRPs from tyrosine (Tyr) showed the most potent antioxidant capacity but very limited BIC, whereas Cys-MRPs showed both higher antioxidant capacity and BIC compared to other amino acids. Partial least squares regression analysis showed positive and significant correlation between BIC and Fe 2+ reducing power of MRPs from 12 amino acids with glucose or fructose, except Lys, Cys and Tyr. The suitable pH for generating efficient browning inhibition compounds varies depending on different amino acids: acidic pH was favorable for Cys, whereas neutral and alkaline pH were suitable for His and Arg, respectively. Increasing both heating temperature and time over a certain range could improve the BIC of MRPs of Cys, His and Arg, whereas any further increase deteriorates their browning inhibition efficiencies. The types of amino acid, initial pH, temperature and time of the Maillard reaction were found to greatly influence the BIC and antioxidant capacity of the resulting MRPs. There is no clear relationship between BIC and the antioxidant capacity of MRPs when reactant type and processing parameters of the Maillard

  4. Characterization of polyphenol oxidase from the Manzanilla cultivar (Olea europaea pomiformis) and prevention of browning reactions in bruised olive fruits.

    Science.gov (United States)

    Segovia-Bravo, Kharla A; Jarén-Galan, Manuel; García-García, Pedro; Garrido-Fernandez, Antonio

    2007-08-08

    The crude extract of the polyphenol oxidase (PPO) enzyme from the Manzanilla cultivar (Olea europaea pomiformis) was obtained, and its properties were characterized. The browning reaction followed a zero-order kinetic model. Its maximum activity was at pH 6.0. This activity was completely inhibited at a pH below 3.0 regardless of temperature; however, in alkaline conditions, pH inhibition depended on temperature and was observed at values above 9.0 and 11.0 at 8 and 25 degrees C, respectively. The thermodynamic parameters of substrate oxidation depended on pH within the range in which activity was observed. The reaction occurred according to an isokinetic system because pH affected the enzymatic reaction rate but not the energy required to carry out the reaction. In the alkaline pH region, browning was due to a combination of enzymatic and nonenzymatic reactions that occurred in parallel. These results correlated well with the browning behavior observed in intentionally bruised fruits at different temperatures and in different storage solutions. The use of a low temperature ( approximately 8 degrees C) was very effective for preventing browning regardless of the cover solution used.

  5. Revealing Brown Carbon Chromophores Produced in Reactions of Methylglyoxal with Ammonium Sulfate.

    Science.gov (United States)

    Lin, Peng; Laskin, Julia; Nizkorodov, Sergey A; Laskin, Alexander

    2015-12-15

    Atmospheric brown carbon (BrC) is an important contributor to light absorption and climate forcing by aerosols. Reactions between small water-soluble carbonyls and ammonia or amines have been identified as one of the potential pathways of BrC formation. However, detailed chemical characterization of BrC chromophores has been challenging and their formation mechanisms are still poorly understood. Understanding BrC formation is impeded by the lack of suitable methods which can unravel the variability and complexity of BrC mixtures. This study applies high performance liquid chromatography (HPLC) coupled to photodiode array (PDA) detector and high resolution mass spectrometry (HRMS) to investigate optical properties and chemical composition of individual BrC components produced through reactions of methylglyoxal (MG) and ammonium sulfate (AS), both of which are abundant in the atmospheric environment. A direct relationship between optical properties and chemical composition of 30 major BrC chromophores is established. Nearly all of these chromophores are nitrogen-containing compounds that account for >70% of the overall light absorption by the MG+AS system in the 300-500 nm range. These results suggest that reduced-nitrogen organic compounds formed in reactions between atmospheric carbonyls and ammonia/amines are important BrC chromophores. It is also demonstrated that improved separation of BrC chromophores by HPLC will significantly advance understanding of BrC chemistry.

  6. Highly Dispersed NiO Nanoparticles Decorating graphene Nanosheets for Non-enzymatic Glucose Sensor and Biofuel Cell

    Science.gov (United States)

    Zeng, Guisheng; Li, Weiping; Ci, Suqin; Jia, Jingchun; Wen, Zhenhai

    2016-11-01

    Nickel oxide-decorated graphene nanosheet (NiO/GNS), as a novel non-enzymatic electrocatalyst for glucose oxidation reaction (GOR), was synthesized through a facile hydrothermal route followed by the heat treatment. The successful synthesis of NiO/GNS was characterized by a series of techniques including XRD, BET, SEM and TEM. Significantly, the NiO/GNS catalyst show excellent catalytic activity toward GOR, and was employed to develop a sensitive non-enzymatic glucose sensor. The developed glucose sensor could response to glucose in a wide range from 5 μM-4.2 mM with a low detection limit (LOD) of 5.0 μM (S/N = 3). Importantly, compared with bare NiO, the catalytic activity of NiO/GNS was much higher. The reason might be that the 2D structure of graphene could prevent the aggregation of NiO and facilitate the electron transfer at electrode interface. Moreover, the outstanding catalytic activity of NiO/GNS was further demonstrated by applying it to construct a biofuel cell using glucose as fuel, which exhibited high stability and current density.

  7. One-pot non-enzymatic formation of firefly luciferin in a neutral buffer from p-benzoquinone and cysteine.

    Science.gov (United States)

    Kanie, Shusei; Nishikawa, Toshio; Ojika, Makoto; Oba, Yuichi

    2016-04-21

    Firefly luciferin, the substrate for the bioluminescence reaction of luminous beetles, possesses a benzothiazole ring, which is rare in nature. Here, we demonstrate a novel one-pot reaction to give firefly luciferin in a neutral buffer from p-benzoquinone and cysteine without any synthetic reagents or enzymes. The formation of firefly luciferin was low in yield in various neutral buffers, whereas it was inhibited or completely prevented in acidic or basic buffers, in organic solvents, or under a nitrogen atmosphere. Labelling analysis of the firefly luciferin using stable isotopic cysteines showed that the benzothiazole ring was formed via the decarboxylation and carbon-sulfur bond rearrangement of cysteine. These findings imply that the biosynthesis of firefly luciferin can be developed/evolved from the non-enzymatic production of firefly luciferin using common primary biosynthetic units, p-benzoquinone and cysteine.

  8. Quantum chemical investigation of the primary thermal pyrolysis reactions of the sodium carboxylate group in a brown coal model.

    Science.gov (United States)

    Li, Jian; Zhang, Baisheng; Zhang, Zhiqiang; Yan, Kefeng; Kang, Lixun

    2014-12-01

    The primary pyrolysis mechanisms of the sodium carboxylate group in sodium benzoate-used as a model compound of brown coal-were studied by performing quantum chemical computations using B3LYP and the CBS method. Various possible reaction pathways involving reactions such as unimolecular and bimolecular decarboxylation and decarbonylation, crosslinking, and radical attack in the brown coal matrix were explored. Without the participation of reactive radicals, unimolecular decarboxylation to release CO2 was calculated to be the most energetically favorable primary reaction pathway at the B3LYP/6-311+G (d, p) level of theory, and was also found to be more energetically favorable than decarboxylation of an carboxylic acid group. When CBS-QBS results were included, crosslinking between the sodium carboxylate group and the carboxylic acid and the decarboxylation of the sodium carboxylate group (catalyzed by the phenolic hydroxyl group) were found to be possible; this pathway competes with unimolecular decarboxylation of the sodium carboxylate group. Provided that H and CH3 radicals are present in the brown coal matrix and can access the sodium carboxylate group, accelerated pyrolysis of the sodium carboxylate group becomes feasible, leading to the release of an Na atom or an NaCO2 radical at the B3LYP/6-311+G (d, p) or CBS-QB3 level of theory, respectively.

  9. Mechanisms of browning development in aggregates of marine organic matter formed under anoxic conditions: A study by mid-infrared and near-infrared spectroscopy

    Science.gov (United States)

    Mecozzi, Mauro; Acquistucci, Rita; Nisini, Laura; Conti, Marcelo Enrique

    2014-03-01

    In this paper we analyze some chemical aspects concerning the browning development associated to the aggregation of marine organic matter (MOM) occurring in anoxic conditions. Organic matter samples obtained by the degradation of different algal samples were daily taken to follow the evolution of the aggregation process and the associated browning process. These samples were examined by Fourier transform mid infrared (FTIR) and Fourier transform near infrared (FTNIR) spectroscopy and the colour changes occurring during the above mentioned aggregation process were measured by means of Colour Indices (CIs). Spectral Cross Correlation Analysis (SCCA) was applied to correlate changes in CI values to the structural changes of MOM observed by FTIR and FTNIR spectra which were also submitted to Two-Dimensional Hetero Correlation Analysis (2HDCORR). SCCA results showed that all biomolecules present in MOM aggregates such as carbohydrates, proteins and lipids are involved in the browning development. In particular, SCCA results of algal mixtures suggest that the observed yellow-brown colour can be linked to the development of non enzymatic (i.e. Maillard) browning reactions. SCCA results for MOM furthermore suggest that aggregates coming from brown algae also showed evidence of browning related to enzymatic reactions. In the end 2HDCORR results indicate that hydrogen bond interactions among different molecules of MOM can play a significant role in the browning development.

  10. Non-enzymatic translocation in ribosomes from streptomycin-resistant mutants of Escherichia coli.

    Science.gov (United States)

    Asatryan, L S; Spirin, A S

    1975-07-10

    The capablity of ribosomes of four types of streptomycin-resistant mutants (A1, A2, A40 and A60) for non-enzymatic (EF-G--GTP-independent) translocation was tested. It was found that an A40 type mutation (amino acid replacement in position 87 of the protein S12 polypeptide chain) leads to activation of the capablity of the ribosome to perform spontaneous non-enzymatic translocation, while type A1, A2 and A60 mutations (amino acid replacements in position 42 of protein S12) does not give such an effect. Thus, it is shown that non-enzymatic translocation can be activated not only by the earlier described damage of the protein S12 by para-chloromercuribenzoate or by the complete removal of protein S12, but also by a definate mutational alteration of the protein. Preliminary data are also reported on the possibility of activating non-enzymatic translocation by combinations of mutational alterations of the ribosomal proteins other than protein S12 but interdepending with it (such as S4 and S5).

  11. The non-enzymatic inactivation of thirteen beta-lactam antibiotics in human faeces

    NARCIS (Netherlands)

    Jansen, G; Weissing, F; de Vries-Hospers, H; Tonk, R; van der Waaij, D

    1992-01-01

    In order to obtain a method that could predict the in vitro inactivation of an antibiotic in the digestive tract, the non-enzymatic inactivation of 13 beta-lactam antibiotics by human faeces was investigated. Benzylpenicillin, amoxicillin, amoxicillin/clavulanate, cloxacillin, piperacillin,

  12. The non-enzymatic inactivation of thirteen β-lactam antibiotics in human faeces

    NARCIS (Netherlands)

    Jansen, G; Weissing, F; de Vries Hospers, H; Tonk, R; van der Waaij, D

    1992-01-01

    In order to obtain a method that could predict the in vitro inactivation of an antibiotic in the digestive tract, the non-enzymatic inactivation of 13 beta-lactam antibiotics by human faeces was investigated. Benzylpenicillin, amoxicillin, amoxicillin/clavulanate, cloxacillin, piperacillin,

  13. Effect of pH and temperature on browning intensity of coconut sugar and its antioxidant activity

    Directory of Open Access Journals (Sweden)

    Karseno

    2017-09-01

    Full Text Available Coconut sugar is produced by heating coconut neera. The brown color of sugar is derived from non-enzymatic browning Maillard reaction. It is strongly influenced by pH and temperature. In this study, the effect of pH and temperature on browning intensity and antioxidant activity of coconut sugar were examined. The pH of coconut neera was adjusted at 6 and 8 and the temperature of its heating was 100ºC, 105 ºC, 110ºC, and 115ºC, respectively. The browning intensity of sugar was determined by spectrophotometrically at 420 nm. Total phenolic content of sugar was estimated by Folin-Ciocalteu method and antioxidant activity was expressed as DPPH scavenging activity. The results showed that browning intensity and antioxidant activity of sugars was increased with increasing pH of coconut neera and temperature. It was found that the effect of pH at 8 and temperature at 115ºC show highest total phenolics (0.48% and browning intensity (0.35 of sugar. The treatment also exhibited good antioxidant activity (DPPH scavenging activity as high as 40%. This result also indicates that there is a significant correlation between browning intensity and antioxidant activity of coconut sugar.

  14. Quantum chemical investigation of the thermal pyrolysis reactions of the carboxylic group in a brown coal model.

    Science.gov (United States)

    Liu, Shengyu; Zhang, Zhiqiang; Wang, Huifang

    2012-01-01

    Different reaction pathways of the carboxylic group in a brown coal model were investigated by applying density function quantum chemical theory, examining the possible cross-linking and decomposition reactions between the hydrogen bonded carboxylic group-carboxylic group and the carboxylic group-hydroxyl group during the thermal pyrolysis process. The results show that bimolecular dehydration and decarboxylation of hydrogen bonded carboxylic groups have distinctly lower activation barriers and therefore, proceed preferentially at low temperature. The esterification reaction between the hydrogen bonded carboxylic group and hydroxyl group, together with unimolecular decarboxylation of isolated single carboxylic groups were also possible at moderate temperature. Aryl-aryl coupling is thought to occur via radical pyrolysis and recombination at relatively high temperature.

  15. Non-enzymatic glucosylation induced neo-epitopes on human serum albumin: A concentration based study.

    Directory of Open Access Journals (Sweden)

    Km Neelofar

    Full Text Available Hyperglycaemia induced non enzymatic glycation is accelerated in diabetic patients and aggressively involved in diabetes progression. Human serum albumin (HSA is the most abundant protein in blood circulation. In hyperglycaemia, it undergoes fast glycation and results in the impairment of structure. Our previous study has demonstrated structural alterations in Amadori-albumin modified with different glucose concentrations from physiological to pathophysiological range. Here, we focused on immunological characterization of Amadori-albumin. Immunogenicity of Amadori-albumin was analysed by direct binding and competitive ELISA. Amadori-albumin was found to be highly immunogenic (expect albumin modified with 5mM and induced high titre antibodies depending upon the extent of modification. Very high titre antibodies were obtained with albumin modified with 75mM glucose as compared to native albumin. Anti-Amadori-albumin-IgG from rabbit sera exhibited increased recognition of Amadori-albumin than native albumin in competitive immunoassay. Alteration induced in albumin after glucosylation has made it highly immunogenic. Induced antibodies were quite specific for respective immunogens but showed cross-reaction with other Amadori/native proteins. It suggests that glucosylation has generated highly immunogenic epitopes on albumin. Formation of high molecular weight immune complex with retarded mobility further supports specificity of anti-Amadori-albumin-IgG towards Amadori-albumin. It may be concluded that due to early glycation, an array of modification occurred in HSA structure. Such gross structural changes might favour polymerization of most of the native epitopes into potent immunogenic neo-epitopes, but some original epitopes were still active and has contributed in the immunogenicity. It could be concluded that induction of anti-Amadori-albumin antibodies may be due to protection of glucose modified albumin from protiolytic breakdown. We assumed

  16. Non-enzymatic glucosylation induced neo-epitopes on human serum albumin: A concentration based study.

    Science.gov (United States)

    Neelofar, Km; Arif, Zarina; Ahmad, Jamal; Alam, Khursheed

    2017-01-01

    Hyperglycaemia induced non enzymatic glycation is accelerated in diabetic patients and aggressively involved in diabetes progression. Human serum albumin (HSA) is the most abundant protein in blood circulation. In hyperglycaemia, it undergoes fast glycation and results in the impairment of structure. Our previous study has demonstrated structural alterations in Amadori-albumin modified with different glucose concentrations from physiological to pathophysiological range. Here, we focused on immunological characterization of Amadori-albumin. Immunogenicity of Amadori-albumin was analysed by direct binding and competitive ELISA. Amadori-albumin was found to be highly immunogenic (expect albumin modified with 5mM) and induced high titre antibodies depending upon the extent of modification. Very high titre antibodies were obtained with albumin modified with 75mM glucose as compared to native albumin. Anti-Amadori-albumin-IgG from rabbit sera exhibited increased recognition of Amadori-albumin than native albumin in competitive immunoassay. Alteration induced in albumin after glucosylation has made it highly immunogenic. Induced antibodies were quite specific for respective immunogens but showed cross-reaction with other Amadori/native proteins. It suggests that glucosylation has generated highly immunogenic epitopes on albumin. Formation of high molecular weight immune complex with retarded mobility further supports specificity of anti-Amadori-albumin-IgG towards Amadori-albumin. It may be concluded that due to early glycation, an array of modification occurred in HSA structure. Such gross structural changes might favour polymerization of most of the native epitopes into potent immunogenic neo-epitopes, but some original epitopes were still active and has contributed in the immunogenicity. It could be concluded that induction of anti-Amadori-albumin antibodies may be due to protection of glucose modified albumin from protiolytic breakdown. We assumed that this type of

  17. Fabrication of Nickel/nanodiamond/boron-doped diamond electrode for non-enzymatic glucose biosensor

    International Nuclear Information System (INIS)

    Dai, Wei; Li, Mingji; Gao, Sumei; Li, Hongji; Li, Cuiping; Xu, Sheng; Wu, Xiaoguo; Yang, Baohe

    2016-01-01

    Highlights: • Nanodiamonds (NDs) were electrophoretically deposited on the BDD film. • The NDs significantly extended the potential window. • Ni/NDs/BDD electrode was prepared by electrodeposition. • The electrode shows good catalytic activity for glucose oxidation. - Abstract: A stable and sensitive non-enzymatic glucose sensor was prepared by modifying a boron-doped diamond (BDD) electrode with nickel (Ni) nanosheets and nanodiamonds (NDs). The NDs were electrophoretically deposited on the BDD surface, and acted as nucleation sites for the subsequent electrodeposition of Ni. The morphology and composition of the modified BDD electrodes were characterized by field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively. The Ni nanosheet-ND modified BDD electrode exhibited good current response towards the non-enzymatic oxidation of glucose in alkaline media. The NDs significantly extended the potential window. The response to glucose was linear over the 0.2–1055.4-μM range. The limit of detection was 0.05 μM, at a signal-to-noise ratio of 3. The Ni nanosheet-ND/BDD electrode exhibited good selectivity, reproducibility and stability. Its electrochemical performance, low cost and simple preparation make it a promising non-enzymatic glucose sensor.

  18. Demonstration of physical phenomenas and scavenging activity from d-psicose and methionine maillard reaction products

    Directory of Open Access Journals (Sweden)

    Arum Tiyas Suminar

    2017-01-01

    Full Text Available Maillard reaction has been well understood as a non-enzymatic reaction between reducing sugars and amino acids to generate the Maillard reaction products (MRPs. This study is aimed to demonstrate the browning intensity, color development, spectra measurements, scavenging activity, and the correlation between browning intensity and scavenging activity of the MRPs generated from D-Psicose and Methionine (Psi-Met at 50℃. The browning intensity of MRPs was investigated based on the absorbance using spectrophotometer at 420 nm, the color development was observed using digital colorimeter to gained L*a*b* value then calculated as browning index, the spectra development was analyzed using spectrophotometer at 190 - 750 nm, and the scavenging activity was determined with ABTS method using spectrophotometer at 734 nm. The browning intensity, color development, and scavenging activity were improved along with the increase in heating process. Based on spectra analysis, MRPs from Psi-Met was initially detected at 21 h and Psi at 24 h of heating treatment, which indicating that Psi-Met have faster and better reaction than Psi during heating process. Positive non-linear and significant correlation between browning intensity and scavenging activity were assigned. This finding may provide beneficial information of D-psicose and MRPs to the next scientific research and to the food industries which applies MRPs in their products.

  19. Optimization of Maillard Reaction between Glucosamine and Other Precursors by Measuring Browning with a Spectrophotometer.

    Science.gov (United States)

    Ogutu, Benrick; Kim, Ye-Joo; Kim, Dae-Wook; Oh, Sang-Chul; Hong, Dong-Lee; Lee, Yang-Bong

    2017-09-01

    The individual Maillard reactions of glucose, glucosamine, cyclohexylamine, and benzylamine were studied at a fixed temperature of 120°C under different durations by monitoring the absorbance of the final products at 425 nm. Glucosamine was the most individually reactive compound, whereas the reactions of glucose, cyclohexylamine, and benzylamine were not significantly different from each other. Maillard reactions of reaction mixtures consisting of glucosamine-cyclohexylamine, glucosamine-benzylamine, glucose-cyclohexylamine, and glucose-benzylamine were also studied using different concentration ratios under different durations at a fixed temperature of 120°C and pH 9. Maillard reactions in the pairs involving glucosamine were observed to be more intense than those of the pairs involving glucose. Finally, with respect to the concentration ratios, it was observed that in most instances, optimal activity was realized, when the reaction mixtures were in the ratio of 1:1.

  20. Transglycosylation reactions, a main mechanism of phenolics incorporation in coffee melanoidins: Inhibition by Maillard reaction.

    Science.gov (United States)

    Moreira, Ana S P; Nunes, Fernando M; Simões, Cristiana; Maciel, Elisabete; Domingues, Pedro; Domingues, M Rosário M; Coimbra, Manuel A

    2017-07-15

    Under roasting conditions, polysaccharides depolymerize and also are able to polymerize, forming new polymers through non-enzymatic transglycosylation reactions (TGRs). TGRs can also occur between carbohydrates and aglycones, such as the phenolic compounds present in daily consumed foods like coffee. In this study, glycosidically-linked phenolic compounds were quantified in coffee melanoidins, the polymeric nitrogenous brown-colored compounds formed during roasting, defined as end-products of Maillard reaction. One third of the phenolics present were in glycosidically-linked form. In addition, the roasting of solid-state mixtures mimicking coffee beans composition allowed the conclusion that proteins play a regulatory role in TGRs extension and, consequently, modulate melanoidins composition. Overall, the results obtained showed that TGRs are a main mechanism of phenolics incorporation in melanoidins and are inhibited by amino groups through Maillard reaction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Highly ordered Ni–Ti–O nanotubes for non-enzymatic glucose detection

    Energy Technology Data Exchange (ETDEWEB)

    Hang, Ruiqiang, E-mail: hangruiqiang@tyut.edu.cn [Research Institute of Surface Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Liu, Yanlian [Research Institute of Surface Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Gao, Ang [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Bai, Long; Huang, Xiaobo; Zhang, Xiangyu; Lin, Naiming [Research Institute of Surface Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Tang, Bin, E-mail: tangbin@tyut.edu.cn [Research Institute of Surface Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2015-06-01

    Anodization is used to fabricate Ni–Ti–O nanotube (NT) electrodes for non-enzymatic glucose detection. The morphology, microstructure and composition of the materials are characterized by field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). Our results show amorphous and highly ordered NTs with diameter of 50 nm, length of 800 nm, and Ni/Ti ratio (at %) of 0.35 can be fabricated in ethylene glycol electrolyte supplemented with 0.2 wt.% NH{sub 4}F and 0.5 vol.% H{sub 2}O at 30 °C and 25 V for 1 h. Electrochemical experiments indicate that at an applied potential of 0.60 V vs. Ag/AgCl, the electrode exhibits a linear response window for glucose concentrations from 0.002 mM to 0.2 mM with a response time of 10 s, detection limit of 0.13 μM (S/N = 3), and sensitivity of 83 μA mM{sup −1} cm{sup −2}. The excellent performance of the electrode is attributed to its large specific area and fast electron transfer between the NT walls. The good electrochemical performance of the Ni–Ti–O NTs as well as their simple and low-cost preparation method make the strategy promising in non-enzymatic glucose detection. - Highlights: • Highly ordered Ni–Ti–O nanotubes have been fabricated by one-step anodization. • We find H{sub 2}O contents in the electrolyte is critical to successful fabrication of the NTs. • The Ni–Ti–O nanotubes are ideal electrode materials for non-enzymatic glucose detection.

  2. Molecular Investigation of the Mechanism of Non-Enzymatic Hydrolysis of Proteins and the Predictive Algorithm for Susceptibility.

    Science.gov (United States)

    Lauer, Timothy M; Wood, Geoffrey P F; Farkas, David; Sathish, Hasige A; Samra, Hardeep S; Trout, Bernhardt L

    2016-06-14

    A number of potential degradation routes can limit the shelf life of a biotherapeutic. While these are experimentally measurable, the tests to do so require a substantial investment in both time and material, resources rarely available early in the drug development process. To address the potential degradation route of non-enzymatic hydrolysis, we performed a molecular modeling analysis, together with an experimental study, to gain detailed insight into the reaction. On the basis of the mechanism, an algorithm for predicting the likely cleavage sites of a protein has been created. This algorithm measures four key properties during a molecular dynamics simulation, which relate to the key steps of the hydrolysis mechanism, in particular the rate-determining step (which can vary depending on the local environment). The first two properties include the secondary structure and the surface exposure of the amide bond, both of which help detect if the addition of the proton to the amide bond is possible. The second two properties relate to whether the side chain can cyclize and form a furane ring. These two properties are the orientation of the side chain relative to the amide bond and the number of hydrogen bonds between the side chain and the surrounding protein. Overall, the algorithm performs well at identifying reactive versus nonreactive bonds. The algorithm correctly classifies nearly 90% of all amide bonds following an aspartic or glutamic acid residue as reactive or nonreactive.

  3. Electrochemical behavior of Azure A/gold nanoclusters modified electrode and its application as non-enzymatic hydrogen peroxide sensor.

    Science.gov (United States)

    Priya, C; Sivasankari, G; Narayanan, S Sriman

    2012-09-01

    A novel non-enzymatic hydrogen peroxide sensor was developed using Azure A/gold nanoclusters modified graphite electrode. The method of preparation of Azure A/gold nanoclusters was simple and it was characterized by UV-visible spectroscopy, field emission scanning electron microscopy (FESEM) and confocal Raman microscopy. The electrochemical properties of Azure A/gold nanoclusters modified graphite electrode was characterized by cyclic voltammetry. In 0.1M H(2)SO(4) the modified electrode showed redox peaks which correspond to the redox behavior of gold nanoparticle. In 0.1M PBS the modified electrode exhibited well defined redox peaks with the formal potential of -0.253 V which is analogous to the redox reaction of Azure A. The results have shown that the gold nanoclusters has reduced the formal potential of Azure A and enhanced the current due to the fast charge transfer kinetics. Also the modified electrode showed an enhanced electrocatalytic activity towards the reduction of H(2)O(2) in the concentration range of 3.26×10(-6)M to 3.2×10(-3)M with a detection limit of 1.08×10(-6)M (S/N=3). The proposed electrode exhibited good stability and reproducibility, and it has the potential application as a sensor for other biologically significant compounds. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Local adaptation at the transcriptome level in brown trout: evidence from early life history temperature genomic reaction norms.

    Directory of Open Access Journals (Sweden)

    Kristian Meier

    Full Text Available Local adaptation and its underlying molecular basis has long been a key focus in evolutionary biology. There has recently been increased interest in the evolutionary role of plasticity and the molecular mechanisms underlying local adaptation. Using transcriptome analysis, we assessed differences in gene expression profiles for three brown trout (Salmo trutta populations, one resident and two anadromous, experiencing different temperature regimes in the wild. The study was based on an F2 generation raised in a common garden setting. A previous study of the F1 generation revealed different reaction norms and significantly higher QST than FST among populations for two early life-history traits. In the present study we investigated if genomic reaction norm patterns were also present at the transcriptome level. Eggs from the three populations were incubated at two temperatures (5 and 8 degrees C representing conditions encountered in the local environments. Global gene expression for fry at the stage of first feeding was analysed using a 32k cDNA microarray. The results revealed differences in gene expression between populations and temperatures and population × temperature interactions, the latter indicating locally adapted reaction norms. Moreover, the reaction norms paralleled those observed previously at early life-history traits. We identified 90 cDNA clones among the genes with an interaction effect that were differently expressed between the ecologically divergent populations. These included genes involved in immune- and stress response. We observed less plasticity in the resident as compared to the anadromous populations, possibly reflecting that the degree of environmental heterogeneity encountered by individuals throughout their life cycle will select for variable level of phenotypic plasticity at the transcriptome level. Our study demonstrates the usefulness of transcriptome approaches to identify genes with different temperature reaction

  5. Investigation of heat induced reactions between lipid oxidation products and amino acids in lipid rich model systems and hazelnuts.

    Science.gov (United States)

    Karademir, Yeşim; Göncüoğlu, Neslihan; Gökmen, Vural

    2013-07-01

    This study aimed to investigate the contribution of lipid oxidation to non-enzymatic browning reactions in lipid rich model and actual food systems. Hazelnut oil and model reaction mixtures consisting of different amino acids were heated under certain conditions to determine possible lipid oxidation and non-enzymatic browning reaction products. In model systems, the Schiff base of 2,4-decadienal, its decarboxylated form, and reaction products formed after hydrolytic cleavage of the Schiff base or decarboxylated form were identified by high resolution mass spectrometry. No furosine was detected in hazelnuts after roasting at 160 °C while the concentration of free amino acids significantly decreased. 2,4-Decadienal reacted effectively with all amino acids studied through a Maillard type carbonyl-amine condensation pathway. (2E,4E)-Deca-2,4-dien-1-amine was identified as a typical reaction product in model systems and roasted hazelnuts. In lipid-rich foods like hazelnuts, lipid-derived carbonyls might be responsible for potential modifications of free and protein bound amino acids during heating.

  6. Non-Enzymatic Glucose Sensor Composed of Carbon-Coated Nano-Zinc Oxide

    Directory of Open Access Journals (Sweden)

    Ren-Jei Chung

    2017-02-01

    Full Text Available Nowadays glucose detection is of great importance in the fields of biological, environmental, and clinical analyzes. In this research, we report a zinc oxide (ZnO nanorod powder surface-coated with carbon material for non-enzymatic glucose sensor applications through a hydrothermal process and chemical vapor deposition method. A series of tests, including crystallinity analysis, microstructure observation, and electrochemical property investigations were carried out. For the cyclic voltammetric (CV glucose detection, the low detection limit of 1 mM with a linear range from 0.1 mM to 10 mM was attained. The sensitivity was 2.97 μA/cm2mM, which is the most optimized ever reported. With such good analytical performance from a simple process, it is believed that the nanocomposites composed of ZnO nanorod powder surface-coated with carbon material are promising for the development of cost-effective non-enzymatic electrochemical glucose biosensors with high sensitivity.

  7. A Highly Sensitive Electrochemical Glucose Sensor By Nickel-Epoxy Electrode With Non-Enzymatic Sensor

    Directory of Open Access Journals (Sweden)

    Riyanto Riyanto

    2016-03-01

    Full Text Available The preparation of new sensor for glucose was based on the fact that glucose can be determined by non-enzymatic glucose oxidase. The Ni metals (99.98% purity, 0.5 mm thick, Aldrich Chemical Company was used to prepare Ni-Epoxy electrode. The Ni-epoxy electrodes were prepared in square cut of 1 cm and 1 mm by length and wide respectively. The Ni metal electrodes were connected to silver wire with silver conducting paint prior covered with epoxy gum. The prepared of nickel-epoxy modified electrode showed outstanding electro catalytic activity toward the oxidation of glucose in alkaline solution. The result from this research are correlation of determination using Nickel-Epoxyelectrode for electroanalysis of glucose in NaOH was R2 = 0.9984. LOQ, LOD and recovery of the Nickel-Epoxy electrode towards glucose were found to be 4.4 μM, 1.48 μM and 98.19%, respectively. The Nickel-Epoxy wire based electrochemical glucose sensor demonstrates good sensitivity, wide linear range, outstanding detection limit, attractive selectivity, good reproducibility, high stability as well as prominent feasibility use of non-enzymatic sensor for monitoring glucose in human urine owing to its advantages of low cost, simple preparation and excellent properties for glucose detection.

  8. Facile synthesis of a silver nanoparticles/polypyrrole nanocomposite for non-enzymatic glucose determination.

    Science.gov (United States)

    Poletti Papi, Maurício A; Caetano, Fabio R; Bergamini, Márcio F; Marcolino-Junior, Luiz H

    2017-06-01

    The present work describes the synthesis of a new conductive nanocomposite based on polypyrrole (PPy) and silver nanoparticles (PPy-AgNP) based on a facile reverse microemulsion method and its application as a non-enzymatic electrochemical sensor for glucose detection. Focusing on the best sensor performance, all experimental parameters used in the synthesis of nanocomposite were optimized based on its electrochemical response for glucose. Characterization of the optimized material by FT-IR, cyclic voltammetry, and DRX measurements and TEM images showed good monodispersion of semispherical Ag nanoparticles capped by PPy structure, with size average of 12±5nm. Under the best analytical conditions, the proposed sensor exhibited glucose response in linear dynamic range of 25 to 2500μmolL -1 , with limit of detection of 3.6μmolL -1 . Recovery studies with human saliva samples varying from 99 to 105% revealed the accuracy and feasibility of a non-enzymatic electrochemical sensor for glucose determination by easy construction and low-cost. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Nitrogen-doped graphene-silver nanodendrites for the non-enzymatic detection of hydrogen peroxide

    International Nuclear Information System (INIS)

    Tajabadi, M.T.; Basirun, W.J.; Lorestani, F.; Zakaria, R.; Baradaran, S.; Amin, Y.M.; Mahmoudian, M.R.; Rezayi, M.; Sookhakian, M.

    2015-01-01

    Highlights: • N-graphene/Ag nanodendrities by electrophoretic and electrochemical deposition. • Support of N-graphene shows efficient electrocatalytic activity toward H 2 O 2 reduction. • The fabricated non-enzymatic H 2 O 2 electrochemical sensor improved in the presence of Ag. - Abstract: An organic-metal hybrid film based on nitrogen-doped graphene-silver nanodendrites (Ag-NG) was fabricated on an indium tin oxide (ITO) electrode using a simple electrophoretic and electrochemical sequential deposition approach. The microwave-assisted method was utilized for the synthesis of nitrogen-doped graphene. This method involves a three-step process consisting of graphite oxidation, exfoliation, and finally chemical reduction with the use of hydrazine as the reducing agent, which leads to the simultaneous reduction of graphene oxide and production of nitrogen-doped graphene. The morphology and structure of the as-fabricated electrode were determined by X-ray diffraction, field emission electron microscopy and transmission electron microscopy. The as-prepared Ag-NG-modified ITO electrode exhibited superior electrocatalytic activity toward hydrogen peroxide (H 2 O 2 ) reduction, with a wide linear detection range of 100 μM to 80 mM (r = 0.9989) and a detection limit of 0.26 μM with a signal-to-noise ratio of 3. Furthermore, the fabricated non-enzymatic H 2 O 2 electrochemical sensor exhibited excellent stability and reproducibility

  10. High Performance Non-enzymatic Glucose Sensor Based on One-Step Electrodeposited Nickel Sulfide.

    Science.gov (United States)

    Kannan, Padmanathan Karthick; Rout, Chandra Sekhar

    2015-06-22

    Nanostructured NiS thin film was prepared by a one-step electrodeposition method and the structural, morphological characteristics of the as-prepared films were analyzed by X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray analysis (EDAX). The electrocatalytic activity of NiS thin film towards glucose oxidation was investigated by fabricating a non-enzymatic glucose sensor and the sensor performance was studied by cyclic voltammetry (CV) and amperometry. The fabricated sensor showed excellent sensitivity and low detection limit with values of 7.43 μA μM(-1)  cm(-2) and 0.32 μM, respectively, and a response time of <8 s. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Role of enzymatic and non enzymatic antioxidant in ameliorating salinity induced damage in nostoc muscorum

    International Nuclear Information System (INIS)

    Hend, A.; Abeer, A.; Allah, A.

    2015-01-01

    Presence of high salt concentration in the growth medium adversely affected the plant growth and productivity by altering its metabolic activities. Experiments were conducted on cyanobacteriaum Nostoc muscorum grown in nitrogen free medium supplemented with 250 mM NaCl to evaluate the salt stress induced changes in growth, antioxidants and lipid composition. Salt stress significantly reduced the growth and physio-biochemical attributes. Salt stress increased malonaldehyde content thereby causing alterations in the lipid fraction. Significant reduction in polyunsaturated fatty acids including phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylinositol (PI) and phosphatidylserine (PS) was observed. Where as diacylglycerol, sterol ester and non-esterified fatty acids were increased. Activities of antioxidant enzymes and contents of non-enzymatic antioxidants including glutathione enhanced due to salt stress. An increase in accumulation of proline was also observed. Hence increased activity of antioxidants and altered fatty acid composition was observed in salt stressed Nostoc muscorum. (author)

  12. Non-Enzymatic Glucose Biosensor Based on CuO-Decorated CeO2 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Panpan Guan

    2016-08-01

    Full Text Available Copper oxide (CuO-decorated cerium oxide (CeO2 nanoparticles were synthesized and used to detect glucose non-enzymatically. The morphological characteristics and structure of the nanoparticles were characterized through transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The sensor responses of electrodes to glucose were investigated via an electrochemical method. The CuO/CeO2 nanocomposite exhibited a reasonably good sensitivity of 2.77 μA mM−1cm−2, an estimated detection limit of 10 μA, and a good anti-interference ability. The sensor was also fairly stable under ambient conditions.

  13. New functionalities of Maillard reaction products as emulsifiers and encapsulating agents, and the processing parameters: a brief review.

    Science.gov (United States)

    Lee, Yee-Ying; Tang, Teck-Kim; Phuah, Eng-Tong; Alitheen, Noorjahan Banu Mohamed; Tan, Chin-Ping; Lai, Oi-Ming

    2017-03-01

    Non-enzymatic browning has been a wide and interesting research area in the food industry, ranging from the complexity of the reaction to its applications in the food industry as well as its ever-debatable health effects. This review provides a new perspective to the Maillard reaction apart from its ubiquitous function in enhancing food flavour, taste and appearance. It focuses on the recent application of Maillard reaction products as an inexpensive and excellent source of emulsifiers as well as superior encapsulating matrices for the entrapment of bioactive compounds. Additionally, it will also discuss the latest approaches employed to perform the Maillard reaction as well as several important reaction parameters that need to be taken into consideration when conducting the Maillard reaction. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  14. Construction of an ultrasensitive non-enzymatic sensor to investigate the dynamic process of superoxide anion release from living cells.

    Science.gov (United States)

    Wei, Hongwei; Shang, Tianyi; Wu, Tiaodi; Liu, Guoan; Ding, Lan; Liu, Xiuhui

    2018-02-15

    In this work, a novel non-enzymatic superoxide anion (O 2 • - ) sensor was constructed based on Ag nanoparticles (NPs) / poly (amidoamine) (PAMAM) dendrimers and used to investigate the dynamic process of O 2 • - release from living cells. The AgNPs/PAMAM nanohybrids were characterized by transmission electron microscopy (TEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The fabricated electrode exhibited excellent catalytic activity toward the reaction of O 2 • - with a super low detection limit (LOD) of 2.530 × 10 -13 M (S/N = 3) and wide linear range of 8 orders of magnitude. It could fulfill the requirement of real-time measurement O 2 • - released from living cells. Furthermore, zymosan was chosen as the stimulant to induce O 2 • - generation from cancer cells (rat adrenal medulla pheochromocytoma cell (PC12)). The electrochemical experiment results indicated that the levels of intracellular O 2 • - depended on the amount of Zymosan. A large amount of O 2 • - generated in the living cells by added heavy stimulant could damage cells seriously. More importantly, a vitro simulation experiment confirmed the role of superoxide dismutase (SOD) for the first time because it could maintain the O 2 • - concentration at a normal physiological range. These findings are of great significance for evaluating the metabolic processes of O 2 • - in the biological system, and this work has the tremendous potential application in clinical diagnostics to assess oxidative stress. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Role of non enzymatic synthesis of indole-3-acetic acid in the Ipomoea batatas L. Lam. (sweet potato) response to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lage, C.L.S.; Esquibel, M.A. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Biofisica. Lab. de Fisiologia Vegetal

    1995-12-01

    Indolacetic acid (IAA) production by tryptophan radiolysis was evaluated after irradiation of a tryptophan solution (1.0 mg/ml) with a 2000 Gy dose of gamma rays followed by High Performance Liquid Chromatography (HPLC) analysis. New absorbance peaks at 280 nm were detected in the irradiated solution, one of them having a migration time similar to that of IAA, indicating a0.14% yield for the conversion reaction. The low yield led us to abandon the hypothesis that non-enzymatic IAA synthesis may account for growth simulation. When the electrophoretic patterns of peroxidases from absorbent roots derived from storage roots treated with IAA (1.0 mg/l) or gamma radiation were compared with control, differences were detected only in the irradiated material. Thus the growth radiation-induced effects do not seem to result from a sudden endogenous IAA increment. (author)

  16. Role of non enzymatic synthesis of indole-3-acetic acid in the Ipomoea batatas L. Lam. (sweet potato) response to gamma radiation

    International Nuclear Information System (INIS)

    Lage, C.L.S.; Esquibel, M.A.

    1995-01-01

    Indolacetic acid (IAA) production by tryptophan radiolysis was evaluated after irradiation of a tryptophan solution (1.0 mg/ml) with a 2000 Gy dose of gamma rays followed by High Performance Liquid Chromatography (HPLC) analysis. New absorbance peaks at 280 nm were detected in the irradiated solution, one of them having a migration time similar to that of IAA, indicating a0.14% yield for the conversion reaction. The low yield led us to abandon the hypothesis that non-enzymatic IAA synthesis may account for growth simulation. When the electrophoretic patterns of peroxidases from absorbent roots derived from storage roots treated with IAA (1.0 mg/l) or gamma radiation were compared with control, differences were detected only in the irradiated material. Thus the growth radiation-induced effects do not seem to result from a sudden endogenous IAA increment. (author)

  17. Non-enzymatic cyclic oxygenated metabolites of adrenic, docosahexaenoic, eicosapentaenoic and α-linolenic acids; bioactivities and potential use as biomarkers.

    Science.gov (United States)

    Galano, Jean-Marie; Lee, Jetty Chung-Yung; Gladine, Cecile; Comte, Blandine; Le Guennec, Jean-Yves; Oger, Camille; Durand, Thierry

    2015-04-01

    Cyclic oxygenated metabolites are formed in vivo through non-enzymatic free radical reaction of n-6 and n-3 polyunsaturated fatty acids (PUFAs) such as arachidonic (ARA C20:4 n-6), adrenic (AdA 22:4 n-6), α-linolenic (ALA 18:3 n-3), eicosapentaenoic (EPA 20:5 n-3) and docosahexaenoic (DHA 22:6 n-3) acids. These cyclic compounds are known as isoprostanes, neuroprostanes, dihomo-isoprostanes and phytoprostanes. Evidence has emerged for their use as biomarkers of oxidative stress and, more recently, the n-3PUFA-derived compounds have been shown to mediate bioactivities as secondary messengers. Accordingly, this review will focus on the cyclic oxygenated metabolites generated from AdA, ALA, EPA and DHA. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance". Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Changes in non-enzymatic antioxidant capacity and lipid peroxidation during germination of white, yellow and purple maize seeds

    International Nuclear Information System (INIS)

    Deng, B.; Zhang, Y.; Yang, K.

    2016-01-01

    In this study, the changes in non-enzymatic antioxidant capacity and lipid peroxidation during the germination process of purple, yellow and white maize seeds were compared, under favorable conditions. Results showed that germination can increase non-enzymatic antioxidant capacity (evaluated with ferric reducing power and 2, 2-diphenyl-1-picryl-hydrazyl-hydrate radical scavenging capacity) and lipid peroxidation levels for all these seeds. In addition, non-enzymatic antioxidant capacity observed in the germinating seeds were in the order of purple > yellow > white. However, the highest and lowest levels of lipid peroxidation could be seen during the germination processes of the white and purple seeds, respectively. In addition, the germination rates of the seeds followed the order of white > yellow > purple. Further studies showed that H/sub 2/O/sub 2/ treatment can significantly promote seed germination, especially for purple seeds. In addition, DMTU (dimethylthiourea), a specific scavenger for H/sub 2/O/sub 2/, could slightly but significantly arrest dormancy release. Data analysis showed that a high negative correlation (R/sup 2/ = -0.955) existed between non-enzymatic antioxidant capacity and germination rates. However, a high positive correlation (R/sup 2/ = 0.860) could be detected between lipid peroxidation and germination rates. Finally, lipid peroxidation as a possible novel signaling mechanism for seed germination has been discussed under stress-free conditions. (author)

  19. Prospective randomized study comparing the debriding effect of krill enzymes and a non-enzymatic treatment in venous leg ulcers

    NARCIS (Netherlands)

    Westerhof, W.; van Ginkel, C. J.; Cohen, E. B.; Mekkes, J. R.

    1990-01-01

    The debriding potential of a recently discovered potent enzyme preparation derived from Antarctic krill (Euphausia superba) was compared to a routine non-enzymatic treatment in 31 patients with venous leg ulcers. To assure a reliable interpretation of the cleaning effect, computer image analysis was

  20. Effects of non-enzymatic glycation in human serum albumin. Spectroscopic analysis

    Science.gov (United States)

    Szkudlarek, A.; Sułkowska, A.; Maciążek-Jurczyk, M.; Chudzik, M.; Równicka-Zubik, J.

    2016-01-01

    Human serum albumin (HSA), transporting protein, is exposed during its life to numerous factors that cause its functions become impaired. One of the basic factors - glycation of HSA - occurs in diabetes and may affect HSA-drug binding. Accumulation of advanced glycation end-products (AGEs) leads to diseases e.g. diabetic and non-diabetic cardiovascular diseases, Alzheimer disease, renal disfunction and in normal aging. The aim of the present work was to estimate how non-enzymatic glycation of human serum albumin altered its tertiary structure using fluorescence technique. We compared glycated human serum albumin by glucose (gHSAGLC) with HSA glycated by fructose (gHSAFRC). We focused on presenting the differences between gHSAFRC and nonglycated (HSA) albumin used acrylamide (Ac), potassium iodide (KI) and 2-(p-toluidino)naphthalene-6-sulfonic acid (TNS). Changes of the microenvironment around the tryptophan residue (Trp-214) of non-glycated and glycated proteins was investigated by the red-edge excitation shift method. Effect of glycation on ligand binding was examined by the binding of phenylbutazone (PHB) and ketoprofen (KP), which a primary high affinity binding site in serum albumin is subdomain IIA and IIIA, respectively. At an excitation and an emission wavelength of λex 335 nm and λem 420 nm, respectively the increase of fluorescence intensity and the blue-shift of maximum fluorescence was observed. It indicates that the glycation products decreases the polarity microenvironment around the fluorophores. Analysis of red-edge excitation shift method showed that the red-shift for gHSAFRC is higher than for HSA. Non-enzymatic glycation also caused, that the Trp residue of gHSAFRC becomes less accessible for the negatively charged quencher (I-), KSV value is smaller for gHSAFRC than for HSA. TNS fluorescent measurement demonstrated the decrease of hydrophobicity in the glycated albumin. KSV constants for gHSA-PHB systems are higher than for the unmodified serum

  1. Effects of non-enzymatic glycation in human serum albumin. Spectroscopic analysis.

    Science.gov (United States)

    Szkudlarek, A; Sułkowska, A; Maciążek-Jurczyk, M; Chudzik, M; Równicka-Zubik, J

    2016-01-05

    Human serum albumin (HSA), transporting protein, is exposed during its life to numerous factors that cause its functions become impaired. One of the basic factors --glycation of HSA--occurs in diabetes and may affect HSA-drug binding. Accumulation of advanced glycation end-products (AGEs) leads to diseases e.g. diabetic and non-diabetic cardiovascular diseases, Alzheimer disease, renal disfunction and in normal aging. The aim of the present work was to estimate how non-enzymatic glycation of human serum albumin altered its tertiary structure using fluorescence technique. We compared glycated human serum albumin by glucose (gHSA(GLC)) with HSA glycated by fructose (gHSA(FRC)). We focused on presenting the differences between gHSA(FRC) and nonglycated (HSA) albumin used acrylamide (Ac), potassium iodide (KI) and 2-(p-toluidino)naphthalene-6-sulfonic acid (TNS). Changes of the microenvironment around the tryptophan residue (Trp-214) of non-glycated and glycated proteins was investigated by the red-edge excitation shift method. Effect of glycation on ligand binding was examined by the binding of phenylbutazone (PHB) and ketoprofen (KP), which a primary high affinity binding site in serum albumin is subdomain IIA and IIIA, respectively. At an excitation and an emission wavelength of λex 335nm and λem 420nm, respectively the increase of fluorescence intensity and the blue-shift of maximum fluorescence was observed. It indicates that the glycation products decreases the polarity microenvironment around the fluorophores. Analysis of red-edge excitation shift method showed that the red-shift for gHSA(FRC) is higher than for HSA. Non-enzymatic glycation also caused, that the Trp residue of gHSA(FRC) becomes less accessible for the negatively charged quencher (I(-)), KSV value is smaller for gHSA(FRC) than for HSA. TNS fluorescent measurement demonstrated the decrease of hydrophobicity in the glycated albumin. KSV constants for gHSA-PHB systems are higher than for the

  2. Drying characteristic, enzyme inactivation and browning pigmentation kinetics of controlled humidity-convective drying of banana slices

    Science.gov (United States)

    Sarpong, Frederick; Yu, Xiaojie; Zhou, Cunshan; Oteng-Darko, Patricia; Amenorfe, Leticia Peace; Wu, Bengang; Bai, Junwen; Ma, Haile

    2018-04-01

    Investigating the kinetics of enzyme activities and browning indexes in food are very essential in understanding the enzyme inactivation and browning pigmentation reaction during drying processing. In order to understand and predict accurately the enzyme inactivation and browning pigmentation of banana slices using Relative Humidity (RH)-convective hot air dryer aided by ultrasound (US) pretreatment, this study was conducted. Drying was carried out with 20 kHz frequency of US-pretreatment using three durations (10 20 and 30 min) and RH (10 20 and 30%) conditions at 70 °C and 2.0 m/s air velocity. The kinetic study of both enzyme inactivation and browning pigmentation results were compared to their relevance of fit in terms of coefficient of correlation (R2), the root mean square error (RMSE) and the reduced chi-square (χ 2). First order and second-order polynomial kinetic model fitted well for enzyme inactivation and browning indexes respectively. Both enzymes inactivation kinetics and enzymatic browning index (EBI) declined significantly (p < 0.05) with increasing drying time in all drying conditions and rate of decrease intensified in longer US-pretreatment duration and lower RH conditions. However, shorter US-pretreatment duration and higher RH conditions reduced the non- enzymatic browning index (NBI) significantly. Again, longer US-pretreatment duration and lower RH shortened the drying time but adversely created more microspores from the micrograph study. Longer US pretreatment and lower RH decrease significantly (p < 0.05) the L* and b* values whereas the a* values was increased.

  3. Non-enzymatic electrochemical immunoassay using noble metal nanoparticles: a review

    International Nuclear Information System (INIS)

    Tang, Juan; Tang, Dianping

    2015-01-01

    Electrochemical immunodetection has attracted considerable attention due to its high sensitivity, low cost and simplicity. Large efforts have recently made in order to design ultrasensitive assays. Noble metal nanoparticles (NM-NPs) offer advantages such as high conductivity and large surface-to-volume ratio. NM-NPs therefore are excellent candidates for developing electrochemical platforms for immunodetection and as signal tags. The use of biofunctionalized NM-NPs often results in amplified recognition via stronger loading of signal tags, and also in enhanced signal. This review (with 87 references) gives an overview on the current state in the use of NM-NPs in Non-enzymatic electrochemical immunosensing. We discuss the application of NM-NPs as electrode matrices and as electroactive labels (either as a carrier or as electrocatalytic labels), and compare the materials (mainly nanoparticles of gold, platinum, or of bimetallic materials) in terms of performance (for example by increasing sensitivity via label amplification or via high densities of capture molecules). A conclusion covers current challenges and gives an outlook. Rather than being exhaustive, the review focuses on representative examples that illustrate novel concepts and promising applications. NM-NPs based immunosensing opens a series of concepts for basic research and offers new tools for determination of trace amounts of protein-related analytes in environment and clinical applications. (author)

  4. Non-enzymatic detection of urea using unmodified gold nanoparticles based aptasensor.

    Science.gov (United States)

    Kumar, Piyush; Lambadi, Paramesh Ramulu; Navani, Naveen Kumar

    2015-10-15

    Biosensing nitrogenous compounds like urea is required to control the incidents of Economically Motivated Adulteration (EMA). In this study, we report the FluMag Systematic Evolution of Ligands by Exponential Enrichment (FluMag-SELEX) method to isolate a urea specific DNA aptamer with a dissociation constant (Kd) of 232 nM. The interaction of DNA aptamer with urea has been confirmed by affinity assay, CD analysis, melting curve analysis and truncation studies. Unlike other urea sensing methods reported so far, using this urea aptamer, we demonstrate a simple, 'non-enzymatic' easy-to-use, dual readout aptasensor that exploits unmodified gold nanoparticles (AuNPs) to transduce the signals of aptamer binding to urea in terms of intrinsic fluorescence differences and color changes simultaneously. This method is free from complicated sample processing and labeling steps. The urea aptasensor displays high selectivity for urea and is free from interference from common milk adulterants. The developed aptasensor reliably detects urea adulteration in milk. The response signals linearly correlate with the increasing concentrations of urea in milk ranging from 20mM to 150 mM with detection limit of 20mM. We also show that this aptasensor can also be used as a simple fluorescence based "turn-on" sensor. The results obtained in this study are comparable to the commercial urease based detection methods. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. A non-enzymatic microsurgical dissection technique of mouse embryonic tissues for gene expression profiling applications.

    Science.gov (United States)

    Sun, Li; Lee, May-Yin; Veltmaat, Jacqueline M

    2011-01-01

    With the increased use of gene expression profiling to identify molecular regulators of cellular and developmental mechanisms, developmental biologists face a new challenge in dissecting tissues without cross-contamination or change in RNA profile, and with intact RNA integrity. We have developed a technique that overcomes these problems. We took the dissection of rudimentary mouse embryonic mammary glands as an example, as these structures are particularly difficult to separate from their contiguous ectoderm and strongly adhering mesenchyme. Contrary to conventional enzymatic tissue-separation methods, we blocked transcriptional activity prior to dissection and protected RNA from degradation during dissection, by the use of RNAlater. While RNAlater dehydrates specimens so severely that it interferes with visibility and clean dissection of organs or tissues, we established rehydration conditions that in fact facilitated tissue separation and shortened dissection time to about 10 minutes. The extracted RNA had an excellent quality, rendering it perfectly suitable for transcriptional profiling. Visual inspection of separated tissues and tissue specific gene expression analysis by microarray and RT-PCR confirmed that the tissues were separated with minimal or no cross-contamination. We show that this dissection method can be applied to a broad variety of organs, and that the tissue is still amenable to protein detection. In conclusion, this is a rapid, cheap and effective non-enzymatic tissue separation method which greatly facilitates the exploration of molecular mechanisms in organ formation.

  6. Destructive effect of non-enzymatic glycation on catalase and remediation via curcumin.

    Science.gov (United States)

    Mofidi Najjar, Fayezeh; Taghavi, Fereshteh; Ghadari, Rahim; Sheibani, Nader; Moosavi-Movahedi, Ali Akbar

    2017-09-15

    Non-enzymatic glycation of proteins is a post-translational modification that is produced by a covalent binding between reducing sugars and amino groups of lysine and arginine residues. In this paper the effect of pathological conditions, derived from hyperglycemia on bovine liver catalase (BLC) as a model protein was considered by measuring enzyme activity, reactive oxygen species (ROS) generation, and changes in catalase conformational properties. We observed that in the presence of glucose, the catalase activity gradually decreased. ROS generation was also involved in the glycation process. Thus, decreased BLC activity was partly considered as a result of ROS generation through glycation. However, in the presence of curcumin the amount of ROS was reduced resulting in increased activity of the glycated catalase. The effect of high glucose level and the potential inhibitory effect of curcumin on aggregation and structural changes of catalase were also investigated. Molecular dynamic simulations also showed that interaction of catalase with curcumin resulted in changes in accessible surface area (ASA) and pKa, two effective parameters of glycation, in potential glycation lysine residues. Thus, the decrease in ASA and increase in pKa of important lysine residues were considered as predominant factors in decreased glycation of BLC by curcumin. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Target-responsive DNA hydrogel for non-enzymatic and visual detection of glucose.

    Science.gov (United States)

    Ma, Yanli; Mao, Yu; An, Yuan; Tian, Tian; Zhang, Huimin; Yan, Jinmao; Zhu, Zhi; Yang, Chaoyong James

    2018-03-26

    We have successfully developed a target-responsive aptamer cross-linked hydrogel for the visual detection of glucose, an important biomedical analyte. In this work, the glucose-responsive hydrogel was prepared using the target aptamer and its two short complementary DNA strands grafted onto a linear polyacrylamide chain as cross-linkers. Gold nanoparticles (AuNPs) modified with thiol-PEG were encapsulated in the gel and used as the output signal for visible detection. The complex of glucose and its ligand of boronic acid derivatives (Shinkai's receptor) can bind with the aptamer to disrupt the hydrogel, leading to the release of AuNPs with a distinct red colour in the supernatant. By this method glucose can be detected with the naked eye, and the sensor has a detection limit of 0.44 mM in buffer with the help of UV-Vis spectrophotometry. Furthermore, glucose spiked in 50% urine and 30% serum could also be detected respectively with the naked eye, and glucose was quantitatively detected in 50% urine. The hydrogel system provides a non-enzymatic and visual method for glucose detection, and offers promising applications in biotechnology and biomedicine.

  8. A nanocomposite-based electrochemical sensor for non-enzymatic detection of hydrogen peroxide.

    Science.gov (United States)

    Du, Xin; Chen, Yuan; Dong, Wenhao; Han, Bingkai; Liu, Min; Chen, Qiang; Zhou, Jun

    2017-02-21

    Hydrogen peroxide (H2O2) plays important signaling roles in normal physiology and disease. However, analyzing the actions of H2O2 is often impeded by the difficulty in detecting this molecule. Herein, we report a novel nanocomposite-based electrochemical sensor for non-enzymatic detection of H2O2. Graphene oxide (GO) was selected as the dopant for the synthesis of polyaniline (PANI), leading to the successful fabrication of a water-soluble and stable GO-PANI composite. GO-PANI was subsequently subject to cyclic voltammetry to generate reduced GO-PANI (rGO-PANI), enhancing the conductivity of the material. Platinum nanoparticles (PtNPs) were then electrodeposited on the surface of the rGO-PANI-modified glassy carbon electrode (GCE) to form an electrochemical H2O2 sensor. Compared to previously reported sensors, the rGO-PANI-PtNP/GCE exhibited an expanded linear range, higher sensitivity, and lower detection limit in the quantification of H2O2. In addition, the sensor displayed outstanding reproducibility and selectivity in real-sample examination. Our study suggests that the rGO-PANI-PtNP/GCE may have broad utility in H2O2 detection under physiological and pathological conditions.

  9. Non-Enzymatic Glucose Sensing Using Carbon Quantum Dots Decorated with Copper Oxide Nanoparticles

    Directory of Open Access Journals (Sweden)

    Houcem Maaoui

    2016-10-01

    Full Text Available Perturbations in glucose homeostasis is critical for human health, as hyperglycemia (defining diabetes leads to premature death caused by macrovascular and microvascular complications. However, the simple and accurate detection of glucose in the blood at low cost remains a challenging task, although it is of great importance for the diagnosis and therapy of diabetic patients. In this work, carbon quantum dots decorated with copper oxide nanostructures (CQDs/Cu2O are prepared by a simple hydrothermal approach, and their potential for electrochemical non-enzymatic glucose sensing is evaluated. The proposed sensor exhibits excellent electrocatalytic activity towards glucose oxidation in alkaline solutions. The glucose sensor is characterized by a wide concentration range from 6 µM to 6 mM, a sensitivity of 2.9 ± 0.2 µA·µM−1·cm−2, and a detection limit of 6 µM at a signal-to-noise ratio S/N = 3. The sensors are successfully applied for glucose determination in human serum samples, demonstrating that the CQDs/Cu2O-based glucose sensor satisfies the requirements of complex sample detection with adapted potential for therapeutic diagnostics.

  10. Hierarchical 3-dimensional nickel-iron nanosheet arrays on carbon fiber paper as a novel electrode for non-enzymatic glucose sensing.

    Science.gov (United States)

    Kannan, Palanisamy; Maiyalagan, Thandavarayan; Marsili, Enrico; Ghosh, Srabanti; Niedziolka-Jönsson, Joanna; Jönsson-Niedziolka, Martin

    2016-01-14

    Three-dimensional nickel-iron (3-D/Ni-Fe) nanostructures are exciting candidates for various applications because they produce more reaction-active sites than 1-D and 2-D nanostructured materials and exhibit attractive optical, electrical and catalytic properties. In this work, freestanding 3-D/Ni-Fe interconnected hierarchical nanosheets, hierarchical nanospheres, and porous nanospheres are directly grown on a flexible carbon fiber paper (CFP) substrate by a single-step hydrothermal process. Among the nanostructures, 3-D/Ni-Fe interconnected hierarchical nanosheets show excellent electrochemical properties because of its high conductivity, large specific active surface area, and mesopores on its walls (vide infra). The 3-D/Ni-Fe hierarchical nanosheet array modified CFP substrate is further explored as a novel electrode for electrochemical non-enzymatic glucose sensor application. The 3-D/Ni-Fe hierarchical nanosheet arrays exhibit significant catalytic activity towards the electrochemical oxidation of glucose, as compared to the 3-D/Ni-Fe hierarchical nanospheres, and porous nanospheres. The 3-D/Ni-Fe hierarchical nanosheet arrays can access a large amount of glucose molecules on their surface (mesopore walls) for an efficient electrocatalytic oxidation process. Moreover, 3-D/Ni-Fe hierarchical nanosheet arrays showed higher sensitivity (7.90 μA μM(-1) cm(-2)) with wide linear glucose concentration ranging from 0.05 μM to 0.2 mM, and the low detection limit (LOD) of 0.031 μM (S/N = 3) is achieved by the amperometry method. Further, the 3-D/Ni-Fe hierarchical nanosheet array modified CFP electrode can be demonstrated to have excellent selectivity towards the detection of glucose in the presence of 500-fold excess of major important interferents. All these results indicate that 3-D/Ni-Fe hierarchical nanosheet arrays are promising candidates for non-enzymatic glucose sensing.

  11. Analyses of the in vitro non-enzymatic glycation of peptides/proteins by matrix-assisted laser desorption/ionization mass spectrometry

    Science.gov (United States)

    Lee, Bao-Shiang; Krishnanchettiar, Sangeeth; Lateef, Syed Salman; Gupta, Shalini

    2007-01-01

    Non-enzymatic glycation of proteins with the reducing agent glucose is implicated to be responsible for diabetes-derived complications, food browning, and aging. However, the non-enzymatic glycation process of peptides/proteins is not well understood and further research is needed to gain an understanding of the underlying principles involved in diabetes-related complications. In this study, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry is used to analyze the in vitro glycation of peptides/proteins. In addition to the physiological conditions, harsh conditions (higher concentration of glucose, higher or lower pH, and higher temperature) are also used in this study. Peptides/proteins are reacted with glucose for up to 120 h at 4 [degree sign]C, 37 [degree sign]C, or 65 [degree sign]C. Single and/or multiple glycations are observed using broad pH conditions (from 10% TFA with pKa of 0.5 to pH 10) at various glucose concentrations (from 0.01 M to 1 M). Data suggest that glucose reacts readily with both peptides and proteins, and the efficiency of the glycation increases with higher temperature, higher pH, higher glucose concentration, or longer incubation time. However, influence of the buffer pH on the efficiency of the glycation of peptides is less pronounced compared to that of proteins. This effect could result from denaturation of proteins at higher pH and the resultant exposure of potential glycation sites. This data could lead to the inference that the glycation process of peptides/proteins would occur but proceed very slowly under the diabetes conditions in vivo (37 [degree sign]C, ~neutral pH, ~0.007 M glucose). Postsource decay and MS/MS results of singly glycated angiotensin I, P14R (PPPPPPPPPPPPPPR), and human adrenocorticotropic hormone (ATCH) fragments 1-13 indicate that glucose reacts with the amino group of the N-terminal of ATCH 1-13 and the guanidino group of the arginine residue of both angiotensin I and P14R.

  12. Assessment of collagen quality associated with non-enzymatic cross-links in human bone using Fourier-transform infrared imaging.

    Science.gov (United States)

    Schmidt, F N; Zimmermann, E A; Campbell, G M; Sroga, G E; Püschel, K; Amling, M; Tang, S Y; Vashishth, D; Busse, B

    2017-04-01

    Aging and many disease conditions, most notably diabetes, are associated with the accumulation of non-enzymatic cross-links in the bone matrix. The non-enzymatic cross-links, also known as advanced glycation end products (AGEs), occur at the collagen tissue level, where they are associated with reduced plasticity and increased fracture risk. In this study, Fourier-transform infrared (FTIR) imaging was used to detect spectroscopic changes associated with the formation of non-enzymatic cross-links in human bone collagen. Here, the non-enzymatic cross-link profile was investigated in one cohort with an in vitro ribose treatment as well as another cohort with an in vivo bisphosphonate treatment. With FTIR imaging, the two-dimensional (2D) spatial distribution of collagen quality associated with non-enzymatic cross-links was measured through the area ratio of the 1678/1692cm -1 subbands within the amide I peak, termed the non-enzymatic crosslink-ratio (NE-xLR). The NE-xLR increased by 35% in the ribation treatment group in comparison to controls (p<0.005), with interstitial bone tissue being more susceptible to the formation of non-enzymatic cross-links. Ultra high-performance liquid chromatography, fluorescence microscopy, and fluorometric assay confirm a correlation between the non-enzymatic cross-link content and the NE-xLR ratio in the control and ribated groups. High resolution FTIR imaging of the 2D bone microstructure revealed enhanced accumulation of non-enzymatic cross-links in bone regions with higher tissue age (i.e., interstitial bone). This non-enzymatic cross-link ratio (NE-xLR) enables researchers to study not only the overall content of AGEs in the bone but also its spatial distribution, which varies with skeletal aging and diabetes mellitus and provides an additional measure of bone's propensity to fracture. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Novel synthesis and structural analysis of zinc oxide nanoparticles for the non enzymatic glucose biosensor.

    Science.gov (United States)

    Dayakar, T; Venkateswara Rao, K; Bikshalu, K; Rajendar, V; Park, Si-Hyun

    2017-06-01

    A non-enzymatic glucose biosensor was developed by utilizing the zinc oxide nanoparticles (ZnO NPs) synthesized by a novel green method using the leaf extract of Ocimum tenuiflorum. The structural, optical and morphological properties of ZnO NPs characterized by means of X-ray diffraction (XRD), ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray (EDAX) spectroscopy, and transmission electron microscopy (TEM). The XRD analysis revealed that the ZnO NPs were crystalline and had a hexagonal wurtzite structure. The crystallite size measured by XRD was the same as that measured using SEM and TEM. The UV-vis absorption spectrum estimates the band gap of ZnO NPs present in the range of 2.82 to 3.45eV. The reduction and formation of ZnO NPs mainly due to the involvement of leaf extract bio-molecular compounds analyzed from the FTIR spectra. The SEM result confirms the morphology of the NPs responsible from the various concentration of leaf extract in the synthesis process. HRTEM analysis depicts the spherical structure of ZnO NPs. The synthesized NPs have the average size ranges from 10 to 20nm. The fabricated GCE/ZnO glucose sensor represents superior electro catalytic activity that has been observed for ZnO NPs with a reproducible sensitivity of 631.30μAmM -1 cm -2 , correlation coefficient of R=0.998, linear dynamic range from 1-8.6mM, low detection limit of 0.043μM (S/N=3) and response time<4s. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Electrodeposition and electrocatalytic properties of Pt/Ni–Co nanowires for non-enzymatic glucose detection

    Energy Technology Data Exchange (ETDEWEB)

    Mahshid, Sahar Sadat [Materials Science and Engineering Department, Sharif University of Technology, Tehran 11155-9466 (Iran, Islamic Republic of); State Key Laboratory of Chemo/Biosensing and Chemometrics, Department of Chemistry, Hunan University, Changsha 410082 (China); Mahshid, Sara [School of Engineering, Monash University Sunway Campus, Bandar Sunway 46150 (Malaysia); Dolati, Abolghasem, E-mail: dolati@sharif.edu [Materials Science and Engineering Department, Sharif University of Technology, Tehran 11155-9466 (Iran, Islamic Republic of); Ghorbani, Mohammad [Materials Science and Engineering Department, Sharif University of Technology, Tehran 11155-9466 (Iran, Islamic Republic of); Yang, Lixia [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Luo, Shenglian [State Key Laboratory of Chemo/Biosensing and Chemometrics, Department of Chemistry, Hunan University, Changsha 410082 (China); Cai, Qingyun, E-mail: qycai0001@hnu.cn [State Key Laboratory of Chemo/Biosensing and Chemometrics, Department of Chemistry, Hunan University, Changsha 410082 (China)

    2013-03-25

    Highlights: ► We fabricate a non-enzyme glucose sensor based on the alloyed nanowires of Pt/Ni–Co. ► We design the process on alternate deposition of metals from single bath. ► Cooperation of Pt, Ni and Co leads to good conductivity and catalytic activity. ► Cooperation of Pt, Ni and Co lowers the applied potential of detection in this electrode. ► This electrode provides good current response in detection of low glucose amount. -- Abstract: A nanowire arrays system consisting of an ordered configuration of Pt, Ni and Co was constructed in single-bath solution through pulse electrodeposition. This structure was evaluated as a potential amperometric non-enzymatic sensor to detect glucose in alkaline solution. We observed a strong and fast amperometric response at low applied potential of 0.4 V vs. SCE over linear ranges of 0–0.2 mM and 0.2–8 mM glucose with sensitivities of 1125 and 333 μA mM{sup −1} cm{sup −2}, respectively. We also observed a low detection limit for glucose of 1 μM. Correlation of the electronic and geometric modifications with the electrochemical performance characteristics enhanced catalytic activity of the electrode by applying the Ni and Co components to Pt nanowires structure. The electrode showed good analytical performance and high selectivity with no interference from other oxidable species, demonstrating its promise for developing an effective glucose sensor.

  15. Changes in Non-Enzymatic Antioxidants in the Blood Following Anaerobic Exercise in Men and Women.

    Directory of Open Access Journals (Sweden)

    Magdalena Wiecek

    Full Text Available The aim of this study was to compare changes in total oxidative status (TOS, total antioxidative capacity (TAC and the concentration of VitA, VitE, VitC, uric acid (UA, reduced (GSH and oxidized glutathione (GSSG in blood within 24 hours following anaerobic exercise (AnEx among men and women.10 women and 10 men performed a 20-second bicycle sprint (AnEx. Concentrations of oxidative stress indicators were measured before AnEx and 3, 15 and 30 minutes and 1 hour afterwards. UA, GSH and GSSH were also measured 24 hours after AnEx. Lactate and H+ concentrations were measured before and 3 minutes after AnEx.The increase in lactate and H+ concentrations following AnEx was similar in both sexes. Changes in the concentrations of all oxidative stress indicators were significant and did not differ between men and women. In both sexes, TOS, TAC, TOS/TAC and VitA and VitE concentrations were the highest 3 minutes, VitC concentration was the highest 30 minutes, and UA concentration was the highest 1 hour after AnEx. GSH concentration was significantly lower than the initial concentration from 15 minutes to 24 hour after AnEx. GSSG concentration was significantly higher, while the GSH/GSSG ratio was significantly lower than the initial values 1 hour and 24 hour after AnEx.With similar changes in lactate and H+ concentrations, AnEx induces the same changes in TAC, TOS, TOS/TAC and non-enzymatic antioxidants of low molecular weight in men and women. Oxidative stress lasted at least 24 hours after AnEx.

  16. Enzymatic and non-enzymatic antioxidant potentials of Chlorella vulgaris grown in effluent of a confectionery industry

    OpenAIRE

    Kumar, R. Ranjith; Rao, P. Hanumantha; Subramanian, V. V.; Sivasubramanian, V.

    2011-01-01

    Enzymatic and non-enzymatic antioxidant potentials of Chlorella vulgaris have gained considerable importance in recent decades. C. vulgaris strain highly tolerant to extreme pH variations was isolated and mass-cultivated in the wastewater from a confectionery industry. C.vulgaris showed better growth in wastewater than in improvised CFTRI medium. The microalgal biomass was then screened for the following antioxidants: peroxidase, superoxide dismutase, polyphenol oxidase, glutathione peroxidas...

  17. Non-enzymatic acetylcholine sensor based on Ni–Al layered double hydroxides/ordered mesoporous carbon

    International Nuclear Information System (INIS)

    Ju Jian; Bai Jing; Bo Xiangjie; Guo Liping

    2012-01-01

    Highlights: ► Nanostructured Ni–Al layered double hydroxides supported on ordered mesoporous carbon. ► A non-enzymatic amperometric sensor for acetylcholine. ► High sensitivity, wide linear range, and low limit of detection for acetylcholine. - Abstract: In this work, a novel non-enzymatic acetylcholine (ACh) sensor was constructed based on electrodepoition of Ni–Al layered double hydroxides (Ni–Al LDHs) on ordered mesoporous carbon (OMC) modified glassy carbon (GC) electrode. The obtained Ni–Al LDHs/OMC nanocomposite was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and electrochemical methods. A novel non-enzymatic acetylcholine (ACh) sensor based on Ni–Al LDHs/OMC was developed. Compared with the pristine OMC and Ni–Al LDHs modified electrodes, Ni–Al LDHs/OMC displayed higher electrocatalytic activity toward ACh and gave a wide concentration interval of 2–4922 μM and a low limit of detection (42 nM, R = 0.999), which is better than some reports in the literatures. The sensor also exhibited long-term stability and remarkable antifouling property. The excellent electrocatalysis for ACh can be attributed to the combination of the unique properties of Ni–Al LDHs nanoparticles and the ordered mesostructure of OMCs matrix.

  18. CuO nanoparticles supported on nitrogen and sulfur co-doped graphene nanocomposites for non-enzymatic glucose sensing

    Energy Technology Data Exchange (ETDEWEB)

    Li, Meixia [Hebei University of Engineering, Faculty of Material Science and Engineering (China); Guo, Qingbin, E-mail: guoqingbinhue@163.com [Hebei University of Engineering, Academic Affairs office (China); Xie, Juan; Li, Yongde; Feng, Yapeng [Hebei University of Engineering, Faculty of Material Science and Engineering (China)

    2017-01-15

    Developing highly active catalysts to promote the electrocatalytic glucose oxidation (EGO) is a crucial demand for non-enzymatic glucose sensing. Herein, we reported the use of nitrogen and sulfur co-doped graphene (NSG) as a novel support material for anchoring CuO nanoparticles and obtained CuO/NSG was employed as an efficient EGO catalyst for non-enzymatic glucose sensing. The results showed that the NSG endowed the CuO/NSG with large surface area, increased structural defects, improved conductivity, and strong covalent coupling between NSG and CuO. Owing to the significant contribution of NSG and the synergistic effect of NSG and CuO, the CuO/NSG exhibited a remarkably higher EGO activity than CuO and CuO/reduced graphene oxide. The CuO/NSG-based sensor displayed excellent glucose sensing performances with a considerably low detection limit of 0.07 μM. These findings elucidate that the NSG is a promising support material for non-enzymatic glucose detection.

  19. Preexposure to amorphous silica particles attenuates but also enhances allergic reactions in trimellitic anhydride-sensitized brown Norway rats

    NARCIS (Netherlands)

    Arts, J.H.E.; Schijf, M.A.; Kuper, C.F.

    2008-01-01

    Irritant-induced inflammation of the airways may aggravate respiratory allergy induced by chemical respiratory allergens. Therefore, the effect of airway irritation by synthetic amorphous silica (SAS) on respiratory allergy to trimellitic anhydride (TMA) was studied. Brown Norway (BN) rats were

  20. Non-enzymatic depolymerization of cotton cellulose by fungal mimicking metabolites

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Howell, Caitlin; Jensen, Bo

    2011-01-01

    significant depolymerization effect on cotton cellulose. An oxalic acid/sodium oxalate buffered pH gradient had an inhibitory effect on the reduction of cellulose polymers at increased pH values. The organic iron chelator, EDTA, was found to promote depolymerization of cellulose in combination with Fenton....... The results confirm that low molecular weight metabolites are capable of depolymerizing cellulose and suggest an importance of these mechanisms during incipient decay by brown rot fungi....

  1. epsilon-fructoselysine in urine of rats fed 14C-lysine-labeled casein browned by amino-carbonyl reaction

    International Nuclear Information System (INIS)

    Mori, Bunpei; Kojima, Kazumi; Saito, Susumu

    1980-01-01

    Radioactive substances were identified in urine of rats fed on browned casein, which had been labeled with U- 14 C-L-lysine. When browned casein was ingested by growing rats, high radioactivity was found in urine taken for 24 hr after feeding. Urinary recovery of radioactivity and specific radioactivity were about 9-times as high as those of the control. The radioactive substances were separated by Sephadex gel filtration and ion-exchange chromatography 75 - 83% of the total radioactivity was recovered in the first peak of Sephadex gel filtration. The material with radioactivity was separated into two fractions by ionexchange chromatography. The ratio of radioactivity of these peaks on the chromatogram was about 30 to 70. The main peak was identified as epsilon-fructoselysine with an amino acid autoanalyzer. Urinary epsilon-fructoselysine content of 24 hr after a single dose feeding of 600 mg browned labeled casein was 13 - 18 mg per head. The relationship between epsilon-fructoselysine content as an absorption delayed-material in the small intestinal lumen and the amount excreted in urine was explained in a scheme together with results from previous studies. (author)

  2. Standardization and quality control in quantifying non-enzymatic oxidative protein modifications in relation to ageing and disease

    DEFF Research Database (Denmark)

    Nedić, Olgica; Rogowska-Wrzesinska, Adelina; Rattan, Suresh I S

    2015-01-01

    Post-translational modifications (PTM) of proteins determine the activity, stability, specificity, transportability and lifespan of a protein. Some PTM are highly specific and regulated involving various enzymatic pathways, but there are other non-enzymatic PTM (nePTM), which occur stochastically...... being fully active to totally inactive molecules. Determination of the type and the amount (abundance) of nePTM is essential for establishing connection between specific protein structure and specific biological role. This article summarizes analytical demands for reliable quantification of ne......PTM, including requirements for the assay performance, standardization and quality control, and points to the difficulties, uncertainties and un-resolved issues....

  3. Non-enzymatic modifications in metallothioneins connected to lipid membrane damages: structural and biomimetic studies under reductive radical stress.

    Science.gov (United States)

    Torreggiani, Armida; Chatgilialoglu, Chryssostomos; Ferreri, Carla; Melchiorre, Michele; Atrian, Silvia; Capdevila, Merce'

    2013-10-30

    Metallothioneins (MTs) are small cysteine-rich proteins with the ability to coordinate heavy metal atoms through metal-thiolate bonds, which are widely distributed among the animal and plant kingdoms. Multifunctional roles for MTs have been proposed, including their ability to scavenger various radicals and reactive oxygen species. In the present article we summarize available information of four MT polypeptides from different organisms, forming metal complexes with Zn(II), Cd(II) or Cu (I) ions. Non-enzymatic modifications of MTs under ionizing radiations and their consequences on the lipidic membrane compartment were studied by Raman spectroscopy and a biomimetic model, respectively. The latter is based on liposome technology and allows to measure the trans unsaturated fatty acid content as a result of reductive radical stress on MTs. The effect of radical stress on the cell metabolism and functions is a very active field of research connecting various disciplines in life sciences. In this contest tandem radical damage has been the subject of recent investigations that pointed out its harmfulness in the general scenario of establishing the consequences of radical stress. By using biomimetic models of tandem damage we have for the first time tested the capability of metallothioneins (MTs), small metalloproteins rich of Cys residues, to damage another cell compartment like lipid membranes when they are undergone to reductive radical stress. The connection of MT reactivity with membrane lipid transformation can give a contribution to the puzzling context of radical stress occurring to biomolecules and the role as biological signaling. To this purpose, MT polypeptides from different organisms, exhibiting different sequence peculiarities, have been analyzed here. The spectroscopic analysis of these systems has allowed to identify modifications affecting metal-thiolate clusters, cystines, and Met residues, acting as efficient interceptors of reducing radical species

  4. Synthesis of CdS quantum dots decorated graphene nanosheets and non-enzymatic photoelectrochemical detection of glucose

    International Nuclear Information System (INIS)

    Zhang, Xuyan; Xu, Fang; Zhao, Bingqing; Ji, Xin; Yao, Yanwen; Wu, Dapeng; Gao, Zhiyong; Jiang, Kai

    2014-01-01

    Graphical abstract: - Highlights: • Graphene-CdS hybrid materials were prepared via one-step hydrothermal method. • Graphene-CdS was used as non-enzymatic photoelectrochemical sensor to detect glucose. • Glucose in real sample was detected and showed good specificity and sensitivity. - ABSTRACT: Graphene-CdS quantum dots (QDs) hybrid materials were successfully prepared via one-step hydrothermal method. CdS QDs with average size of ∼6 nm were dispersed on graphene sheets with high coverage through non-covalent bonding. Photocurrent and electrochemical impedance spectroscopy (EIS) results suggested that the best dosage of graphene oxide for graphene-CdS hybrid materials is 0.5% (G0.5-CdS). When G0.5-CdS QDs was used as photoanode materials in non-enzymatic sensor, and the sensor was used to detect glucose and displayed satisfactory analytical performance with good linear range from 0.1∼4 mmol dm −3 with a detection limit of 7 μmol dm −3 at a signal-to-noise ratio of 3. The sensor also possessed high selectivity and durability in trace detection of glucose

  5. Non-enzymatic lipid oxidation products in biological systems: assessment of the metabolites from polyunsaturated fatty acids.

    Science.gov (United States)

    Vigor, Claire; Bertrand-Michel, Justine; Pinot, Edith; Oger, Camille; Vercauteren, Joseph; Le Faouder, Pauline; Galano, Jean-Marie; Lee, Jetty Chung-Yung; Durand, Thierry

    2014-08-01

    Metabolites of non-enzymatic lipid peroxidation of polyunsaturated fatty acids notably omega-3 and omega-6 fatty acids have become important biomarkers of lipid products. Especially the arachidonic acid-derived F2-isoprostanes are the classic in vivo biomarker for oxidative stress in biological systems. In recent years other isoprostanes from eicosapentaenoic, docosahexaenoic, adrenic and α-linolenic acids have been evaluated, namely F3-isoprostanes, F4-neuroprostanes, F2-dihomo-isoprostanes and F1-phytoprostanes, respectively. These have been gaining interest as complementary specific biomarkers in human diseases. Refined extraction methods, robust analysis and elucidation of chemical structures have improved the sensitivity of detection in biological tissues and fluids. Previously the main reliable instrumentation for measurement was gas chromatography-mass spectrometry (GC-MS), but now the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and immunological techniques is gaining much attention. In this review, the types of prostanoids generated from non-enzymatic lipid peroxidation of some important omega-3 and omega-6 fatty acids and biological samples that have been determined by GC-MS and LC-MS/MS are discussed. Copyright © 2014. Published by Elsevier B.V.

  6. A high performance non-enzymatic glucose sensor based on nickel hydroxide modified nitrogen-incorporated nanodiamonds.

    Science.gov (United States)

    Ko, Chih-Yu; Huang, Jin-Hua; Raina, Supil; Kang, Weng P

    2013-06-07

    A highly selective, sensitive, and stable non-enzymatic glucose sensor based on Ni hydroxide modified nitrogen-incorporated nanodiamonds (Ni(OH)2-NND) was developed. The sensor was fabricated by e-beam evaporation of a thin Ni film on NND followed by the growth of Ni(OH)2 using an electrochemical process. It was found that the Ni film thickness greatly affects the morphology and electro-catalytic activity of the as-synthesized electrode for non-enzymatic glucose oxidation. Owing to its nanostructure characteristics, the best sensor fabricated by 150 nm Ni deposition showed two wide response ranges, namely, 0.02-1 mM and 1-9 mM, with sensitivities of 3.20 and 1.41 mA mM(-1) cm(-2), respectively, and a detection limit of 1.2 μM (S/N = 3). The sensor also showed good long-term stability as well as high selectivity in the presence of interferences such as ascorbic acid, acetaminophen, and uric acid. This finding reveals the possibility of exploiting the NND as an electrochemical biosensor platform where high performance addressable sensor arrays could be built.

  7. Flexible electronics-compatible non-enzymatic glucose sensing via transparent CuO nanowire networks on PET films

    Science.gov (United States)

    Bell, Caroline; Nammari, Abdullah; Uttamchandani, Pranay; Rai, Amit; Shah, Pujan; Moore, Arden L.

    2017-06-01

    Diabetic individuals need simple, accurate, and cost effective means by which to independently assess their glucose levels in a non-invasive way. In this work, a sensor based on randomly oriented CuO nanowire networks supported by a polyethylene terephthalate thin film is evaluated as a flexible, transparent, non-enzymatic glucose sensing system analogous to those envisioned for future wearable diagnostic devices. The amperometric sensing characteristics of this type of device architecture are evaluated both before and after bending, with the system’s glucose response, sensitivity, lower limit of detection, and effect of applied bias being experimentally determined. The obtained data shows that the sensor is capable of measuring changes in glucose levels within a physiologically relevant range (0-12 mM glucose) and at lower limits of detection (0.05 mM glucose at +0.6 V bias) consistent with patient tears and saliva. Unlike existing studies utilizing a conductive backing layer or macroscopic electrode setup, this sensor demonstrates a percolation network-like trend of current versus glucose concentration. In this implementation, controlling the architectural details of the CuO nanowire network could conceivably allow the sensor’s sensitivity and optimal sensing range to be tuned. Overall, this work shows that integrating CuO nanowires into a sensor architecture compatible with transparent, flexible electronics is a promising avenue to realizing next generation wearable non-enzymatic glucose diagnostic devices.

  8. Enhanced sensitivity in non-enzymatic glucose detection by improved growth kinetics of Ni-based nanostructures

    Science.gov (United States)

    Urso, M.; Pellegrino, G.; Strano, V.; Bruno, E.; Priolo, F.; Mirabella, S.

    2018-04-01

    Ni-based nanostructures are attractive catalytic materials for many electrochemical applications, among which are non-enzymatic sensing, charge storage, and water splitting. In this work, we clarify the synthesis kinetics of Ni(OH)2/NiOOH nanowalls grown by chemical bath deposition at room temperature and at 50 °C. We applied the results to non-enzymatic glucose sensing, reaching a highest sensitivity of 31 mA cm-2mM-1. Using scanning electron microscopy, x-ray diffraction analysis and Rutherford backscattering spectrometry we found that the growth occurs through two regimes: first, a quick random growth leading to disordered sheets of Ni oxy-hydroxide, followed by a slower growth of well-aligned sheets of Ni hydroxide. A high growth temperature (50 °C), leading mainly to well-aligned sheets, offers superior electrochemical properties in terms of charge storage, charge carrier transport and catalytic action, as confirmed by cyclic voltammetry and electrochemical impedance spectroscopy analyses. The reported results on the optimization and application of low-cost synthesis of these Ni-based nanostructures have a large potential for application in catalysis, (bio)sensing, and supercapacitors areas.

  9. Local adaptation at the transcriptome level in brown trout: Evidence from early life history temperature genomic reaction norms

    DEFF Research Database (Denmark)

    Meier, Kristian; Hansen, Michael Møller; Normandeau, Eric

    2014-01-01

    reaction norms and significantly higher QST than FST among populations for two early life-history traits. In the present study we investigated if genomic reaction norm patterns were also present at the transcriptome level. Eggs from the three populations were incubated at two temperatures (5 and 8 degrees......, the latter indicating locally adapted reaction norms. Moreover, the reaction norms paralleled those observed previously at early life-history traits. We identified 90 cDNA clones among the genes with an interaction effect that were differently expressed between the ecologically divergent populations....... These included genes involved in immune- and stress response. We observed less plasticity in the resident as compared to the anadromous populations, possibly reflecting that the degree of environmental heterogeneity encountered by individuals throughout their life cycle will select for variable level...

  10. Effect of Cadmium Stress on Non-enzymatic Antioxidant and Nitric Oxide Levels in Two Varieties of Maize (Zea mays).

    Science.gov (United States)

    Akinyemi, Ayodele Jacob; Faboya, Oluwabamise Lekan; Olayide, Israel; Faboya, Opeyemi Ayodeji; Ijabadeniyi, Tosin

    2017-06-01

    Cadmium (Cd) is one of the most toxic heavy metals that inhibit physiological processes of plants. Hence, the present study sought to investigate the effect of cadmium-contaminated seeds from two varieties of maize (Zea mays) on non-enzymatic antioxidant and nitric oxide levels. Seeds of yellow and white maize were exposed to different concentrations of Cd (0, 1, 3 and 5 ppm) for two weeks. The results from this study revealed that both varieties of maize bio-accumulate Cd in leaves in a dose-dependent manner. In addition, Cd exposure caused a significant (p < 0.05) decrease in total phenolic, GSH and nitric oxide (NO) levels at the highest concentration tested when compared with control. Therefore, the observed decrease in NO and endogenous antioxidant status by Cd treatment in maize plants could suggest some possible mechanism of action for Cd-induced oxidative stress and counteracting effect of the plants against Cd toxicity.

  11. Phosphomolybdic acid functionalized graphene loading copper nanoparticles modified electrodes for non-enzymatic electrochemical sensing of glucose

    International Nuclear Information System (INIS)

    Xu, Jiaoyan; Cao, Xiyue; Xia, Jianfei; Gong, Shida; Wang, Zonghua; Lu, Lin

    2016-01-01

    A sensitive non-enzymatic glucose electrochemical biosensor (Cu/PMo 12 -GR/GCE) was developed based on the combination of copper nanoparticles (CuNPs) and phosphomolybdic acid functionalized graphene (PMo 12 -GR). PMo 12 -GR films were modified on the surface of glassy carbon electrode (GCE) through electrostatic self-assembly with the aid of poly diallyl dimethyl ammonium chloride (PDDA). Then CuNPs were successfully decorated onto the PMo 12 -GR modified GCE through electrodeposition. The morphology of Cu/PMo 12 -GR/GCE was characterized by scanning electron microscope (SEM). Cyclic voltammetry (CV) and chronoamperometry were used to investigate the electrochemical performances of the biosensor. The results indicated that the modified electrode displayed a synergistic effect of PMo 12 -GR sheets and CuNPs towards the electro-oxidation of glucose in the alkaline solution. At the optimal detection potential of 0.50 V, the response towards glucose presented a linear response ranging from 0.10 μM to 1.0 mM with a detection limit of 3.0 × 10 −2  μM (S/N = 3). In addition, Cu/PMo 12 -GR/GCE possessed a high selectivity, good reproducibility, excellent stability and acceptable recovery, which indicating the potential application in clinical field. - Highlights: • Cu/PMo 12 -GR/GCE as a non-enzymatic glucose electrochemical sensor. • PMo 12 is efficient for the uniform growth of Cu-NPs and electron transport. • The sensor exhibits good sensitivity and specificity towards glucose.

  12. Phosphomolybdic acid functionalized graphene loading copper nanoparticles modified electrodes for non-enzymatic electrochemical sensing of glucose

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jiaoyan; Cao, Xiyue [College of Chemistry and Chemical Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071 (China); Xia, Jianfei, E-mail: xiajianfei@126.com [College of Chemistry and Chemical Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071 (China); Gong, Shida [College of Chemistry and Chemical Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071 (China); Wang, Zonghua, E-mail: wangzonghua@qdu.edu.cn [College of Chemistry and Chemical Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071 (China); Lu, Lin [College of Chemistry and Chemical Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071 (China); Zibo Normal College, Zibo, Shandong 255100 (China)

    2016-08-31

    A sensitive non-enzymatic glucose electrochemical biosensor (Cu/PMo{sub 12}-GR/GCE) was developed based on the combination of copper nanoparticles (CuNPs) and phosphomolybdic acid functionalized graphene (PMo{sub 12}-GR). PMo{sub 12}-GR films were modified on the surface of glassy carbon electrode (GCE) through electrostatic self-assembly with the aid of poly diallyl dimethyl ammonium chloride (PDDA). Then CuNPs were successfully decorated onto the PMo{sub 12}-GR modified GCE through electrodeposition. The morphology of Cu/PMo{sub 12}-GR/GCE was characterized by scanning electron microscope (SEM). Cyclic voltammetry (CV) and chronoamperometry were used to investigate the electrochemical performances of the biosensor. The results indicated that the modified electrode displayed a synergistic effect of PMo{sub 12}-GR sheets and CuNPs towards the electro-oxidation of glucose in the alkaline solution. At the optimal detection potential of 0.50 V, the response towards glucose presented a linear response ranging from 0.10 μM to 1.0 mM with a detection limit of 3.0 × 10{sup −2} μM (S/N = 3). In addition, Cu/PMo{sub 12}-GR/GCE possessed a high selectivity, good reproducibility, excellent stability and acceptable recovery, which indicating the potential application in clinical field. - Highlights: • Cu/PMo{sub 12}-GR/GCE as a non-enzymatic glucose electrochemical sensor. • PMo{sub 12} is efficient for the uniform growth of Cu-NPs and electron transport. • The sensor exhibits good sensitivity and specificity towards glucose.

  13. Preexposure to amorphous silica particles attenuates but also enhances allergic reactions in trimellitic anhydride-sensitized brown Norway rats.

    Science.gov (United States)

    Arts, Josje H E; Schijf, Marcel A; Kuper, C Frieke

    2008-08-01

    Irritant-induced inflammation of the airways may aggravate respiratory allergy induced by chemical respiratory allergens. Therefore, the effect of airway irritation by synthetic amorphous silica (SAS) on respiratory allergy to trimellitic anhydride (TMA) was studied. Brown Norway (BN) rats were topically sensitized on day 0 and on day 7, subsequently exposed for 6 h/day for 6 days to 27 mg/m(3) SAS, and challenged by inhalation to a minimally irritating concentration of 12 mg/m(3) TMA, 24 h after the last SAS exposure. An additional group was exposed to SAS before a second challenge to TMA. Control groups were treated with vehicle, and/or did not receive SAS exposure. Breathing parameters, cellular and biochemical changes in bronchoalveolar lavage (BAL) fluid, and histopathological airway changes 24 h after challenge were the main parameters studied. Exposure to SAS alone resulted in transient changes in breathing parameters during exposure, and in nasal and alveolar inflammation with neutrophils and macrophages. Exposure to SAS before a single TMA challenge resulted in a slightly irregular breathing pattern during TMA challenge. SAS also diminished the effect of TMA on tidal volume, laryngeal ulceration, laryngeal inflammation, and the number of BAL (lung) eosinophils in most animals, but aggravated laryngeal squamous metaplasia and inflammation in a single animal. The pulmonary eosinophilic infiltrate and edema induced by a second TMA challenge was diminished by the preceding SAS exposure, but the number of lymphocytes in BAL was increased. Thus, a respiratory particulate irritant like SAS can reduce as well as aggravate certain aspects of TMA-induced respiratory allergy.

  14. Local adaptation at the transcriptome level in brown trout: Evidence from early life history temperature genomic reaction norms

    DEFF Research Database (Denmark)

    Meier, Kristian; Hansen, Michael Møller; Normandeau, Eric

    2014-01-01

    Local adaptation and its underlying molecular basis has long been a key focus in evolutionary biology. There has recently been increased interest in the evolutionary role of plasticity and the molecular mechanisms underlying local adaptation. Using transcriptome analysis, we assessed differences......, the latter indicating locally adapted reaction norms. Moreover, the reaction norms paralleled those observed previously at early life-history traits. We identified 90 cDNA clones among the genes with an interaction effect that were differently expressed between the ecologically divergent populations....... These included genes involved in immune- and stress response. We observed less plasticity in the resident as compared to the anadromous populations, possibly reflecting that the degree of environmental heterogeneity encountered by individuals throughout their life cycle will select for variable level...

  15. Comparative investigation to see the efficacy of polyphenol oxidase inhibitors parallel to sulphite for control of enzymatic browning in guava juice

    International Nuclear Information System (INIS)

    Zai, M.N.K.A.

    2008-01-01

    Comparative study was conducted to determine the efficacy of polyphenol oxidase inhibitors to control browning in guava juice/concentrates parallel to sulfite. Although sulfites are highly effective to control the browning but these have shown adverse effect on health particularly to those who have pulmonary disorder like asthma. Filtration with useful filter aid and juicing agents are found to be helpful in removing browning residue particulates fractions to extend the shelf life of the juice. Non-enzymatic browning can be prevented by cold blanching. (author)

  16. Binderless solution processed Zn doped Co3O4 film on FTO for rapid and selective non-enzymatic glucose detection

    CSIR Research Space (South Africa)

    Chowdhury, M

    2016-09-01

    Full Text Available A simple solution based deposition process has been used to fabricate Zn doped Co(sub3)O(sub4) electrode as an electrocatalyst for non-enzymatic oxidation of glucose. XRD, HRTEM, SEM, EELS, AFM, EIS was used to characterise the electrode...

  17. Studies on the modification of the allergenic potential of proteins form cherry and peanut by non-enzymatic glycosylation and enzymatic browning

    OpenAIRE

    Gruber, Patrick

    2007-01-01

    Im Rahmen der Arbeit wurden Veränderungen der IgE-Bindungskapazität der rekombinanten Allergene rPru av 1 aus Kirsche, rAra h 2 aus Erdnuss sowie Erdnusslectin durch Hitzeeinwirkung, Maillard-Reaktion und enzymatische Bräunung studiert. Ferner wurden peptidische Partialsequenzen von Ara h 2 synthetisiert und untersucht, bei denen die Aminosäuren Cystein, Serin, Lysin und Arginin durch thermische Abbauprodukte bzw. Glykosylierungsprodukte ersetzt waren. Abschließend wurden sog. Multiple Antige...

  18. Physico-chemical properties, oxidative stability and non-enzymatic browning in marine phospholipid emulsions and their use in food applications

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng

    better bioavailability and ability to form liposomes. All these unique properties of marine PL make them an attractive choice as ingredients for food fortification. Nowadays, a wide range of food products fortified with n-3 triglycerides (TAG) are available worldwide. However, the feasibility of using...... marine PL for food fortification has not been explored. The main objective of the present Ph.D. study was to explore the feasibility of using marine PL for food fortification. The secondary objective was to study the physical and oxidative stability of marine PL emulsions while identifying the important...... be prepared by using 2-10 % marine PL. The high physical stability of these emulsions was most likely due to the coexistence of micelles, liposomes and emulsified oil droplets. However, there was a requirement for at least 3 % of marine PL (equivalent to 0.8 - 1.3 % of PC depending on the marine PL sources...

  19. Non-enzymatic amperometric sensor for hydrogen peroxide based on a biocomposite made from chitosan, hemoglobin, and silver nanoparticles

    International Nuclear Information System (INIS)

    Tian, L.; Feng, Y.; Qi, Y.; Wang, B.; Chen, Y.; Fu, X.

    2012-01-01

    We report on a novel non-enzymatic sensor for hydrogen peroxide (HP) that is based on a biocomposite made up from chitosan (CS), hemoglobin (Hb), and silver nanoparticles (AgNPs). The AgNPs were prepared in the presence of CS and glucose in an ultrasonic bath, and CS is found to act as a stabilizing agent. They were then combined with Hb and CS to construct a carbon paste biosensor. The resulting electrode gave a well-defined redox couple for Hb, with a formal potential of about -0.17 V (vs. SCE) at pH 6. 86 and exhibited a remarkable electrocatalytic activity for the reduction of HP. The sensor was used to detect HP by flow injection analysis, and a linear response is obtained in the 0. 08 to 250 μM concentration range. The detection limit is 0.05 μM (at S/N = 3). These characteristics, along with its long-term stability make the sensor highly promising for the amperometric determination of HP. (author)

  20. Nanoporous Carbon Nanofibers Decorated with Platinum Nanoparticles for Non-Enzymatic Electrochemical Sensing of H2O2

    Directory of Open Access Journals (Sweden)

    Yang Li

    2015-11-01

    Full Text Available We describe the preparation of nanoporous carbon nanofibers (CNFs decorated with platinum nanoparticles (PtNPs in this work by electrospining polyacrylonitrile (PAN nanofibers and subsequent carbonization and binding of PtNPs. The fabricated nanoporous CNF-PtNP hybrids were further utilized to modify glass carbon electrodes and used for the non-enzymatic amperometric biosensor for the highly sensitive detection of hydrogen peroxide (H2O2. The morphologies of the fabricated nanoporous CNF-PtNP hybrids were observed by scanning electron microscopy, transmission electron microscopy, and their structure was further investigated with Brunauer–Emmett–Teller (BET surface area analysis, X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectrum. The cyclic voltammetry experiments indicate that CNF-PtNP modified electrodes have high electrocatalytic activity toward H2O2 and the chronoamperometry measurements illustrate that the fabricated biosensor has a high sensitivity for detecting H2O2. We anticipate that the strategies utilized in this work will not only guide the further design and fabrication of functional nanofiber-based biomaterials and nanodevices, but also extend the potential applications in energy storage, cytology, and tissue engineering.

  1. Non-enzymatic glucose sensing properties of MoO3 nanorods: experimental and density functional theory investigations

    Science.gov (United States)

    Sharma, Maneesha; Gangan, Abhijeet; Chakraborty, Brahmananda; Sekhar Rout, Chandra

    2017-11-01

    We report the growth of monoclinic MoO3 nanorods by a simple and highly reproducible hydrothermal method. Structural and morphological studies provide significant insights about the phase and crystalline structure of the synthesized samples. Further, the non-enzymatic glucose sensing properties were investigated and the MoO3 nanorods exhibited a sensitivity of 15.4 µA µM‑1 cm‑2 in the 5–175 µM linear range. Also, a quick response time of 8 s towards glucose molecules was observed, exhibiting an excellent electrochemical activity. We have also performed density functional theory (DFT) simulations to qualitatively support our experimental observations by investigating the interactions and charge-transfer mechanism of glucose on MoO3. There is a strong interaction between glucose and the MoO3 surface due to charge transfer from a bonded O atom of glucose to a Mo atom of MoO3 resulting in a strong hybridization between the p orbital of O and d orbital of Mo. Thus, the MoO3 nanorod-based electrodes are found to be good glucose sensing materials for practical industrial applications.

  2. Cell-cycle regulation of non-enzymatic functions of the Drosophila methyltransferase PR-Set7.

    Science.gov (United States)

    Zouaz, Amel; Fernando, Céline; Perez, Yannick; Sardet, Claude; Julien, Eric; Grimaud, Charlotte

    2018-04-06

    Tight cell-cycle regulation of the histone H4-K20 methyltransferase PR-Set7 is essential for the maintenance of genome integrity. In mammals, this mainly involves the interaction of PR-Set7 with the replication factor PCNA, which triggers the degradation of the enzyme by the CRL4CDT2 E3 ubiquitin ligase. PR-Set7 is also targeted by the SCFβ-TRCP ligase, but the role of this additional regulatory pathway remains unclear. Here, we show that Drosophila PR-Set7 undergoes a cell-cycle proteolytic regulation, independently of its interaction with PCNA. Instead, Slimb, the ortholog of β-TRCP, is specifically required for the degradation of the nuclear pool of PR-Set7 prior to S phase. Consequently, inactivation of Slimb leads to nuclear accumulation of PR-Set7, which triggers aberrant chromatin compaction and G1/S arrest. Strikingly, these phenotypes result from non-enzymatic PR-Set7 functions that prevent proper histone H4 acetylation independently of H4K20 methylation. Altogether, these results identify the Slimb-mediated PR-Set7 proteolysis as a new critical regulatory mechanism required for proper interphase chromatin organization at G1/S transition.

  3. Pulse electrodeposited nickel-indium tin oxide nanocomposite as an electrocatalyst for non-enzymatic glucose sensing

    Energy Technology Data Exchange (ETDEWEB)

    Sivasakthi, P.; Ramesh Bapu, G.N.K., E-mail: rameshbapugnk@cecri.res.in; Chandrasekaran, Maruthai

    2016-01-01

    Nickel and nickel-ITO nanocomposite on mild steel substrate were prepared by pulse electrodeposition method from nickel sulphamate electrolyte and were examined as electrocatalysts for non-enzymatic glucose sensing. The surface morphology, chemical composition, preferred orientation and oxidation states of the nickel metal ion in the deposits were characterized by SEM, EDAX, XRD and XPS. Electrochemical sensing of glucose was studied by cyclic voltammetry and amperometry. The modified Ni-ITO nanocomposite electrode showed higher electrocatalytic activity for the oxidation of glucose in alkaline medium and exhibited a linear range from 0.02 to 3.00 mM with a limit of detection 3.74 μM at a signal-to-noise ratio of 3. The higher selectivity, longer stability and better reproducibility of this electrode compared to nickel in the sensing of glucose are pointers for exploitation in practical clinical applications. - Highlights: • Ni-ITO nanocomposites are prepared by pulse electrocodeposition method from nickel sulphamate solutions. • Ni-ITO nanocomposites are characterized using SEM, EDAX, XRD and XPS. • Electrochemical characteristics of the Ni and Ni-ITO nanocomposite deposits are studied by CV and amperometry techniques. • Ni-ITO nanocomposite electrode could be used as sensing material for detection of glucose in practical condition.

  4. Non-enzymatic detection of glucose using poly(azure A)-nickel modified glassy carbon electrode.

    Science.gov (United States)

    Liu, Tong; Luo, Yiqun; Zhu, Jiaming; Kong, Liyan; Wang, Wen; Tan, Liang

    2016-08-15

    A simple, sensitive and selective non-enzymatic glucose sensor was constructed in this paper. The poly(azure A)-nickel modified glassy carbon electrode was successfully fabricated by the electropolymerization of azure A and the adsorption of Ni(2+). The Ni modified electrode, which was characterized by scanning electron microscope, cyclic voltammetry, electrochemical impedance spectra and X-ray photoelectron spectroscopy measurements, respectively, displayed well-defined current responses of the Ni(III)/Ni(II) couple and showed a good activity for electrocatalytic oxidation of glucose in alkaline medium. Under the optimized conditions, the developed sensor exhibited a broad linear calibration range of 5 μM-12mM for quantification of glucose and a low detection limit of 0.64μM (3σ). The excellent analytical performance including simple structure, fast response time, good anti-interference ability, satisfying stability and reliable reproducibility were also found from the proposed amperometric sensor. The results were satisfactory for the determination of glucose in human serum samples as comparison to those from a local hospital. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Non-enzymatic detection of glucose in fruits using TiO2-Mn3O4 hybrid nano interface

    Science.gov (United States)

    Jayanth Babu, K.; Sasya, Madhurantakam; Nesakumar, Noel; Shankar, Prabakaran; Gumpu, Manju Bhargavi; Ramachandra, Bhat Lakshmishri; Kulandaisamy, Arockia Jayalatha; Rayappan, John Bosco Balaguru

    2017-08-01

    Consumption of fruits leads to increase in glucose level in blood for diabetic patients, which in turn leads to peripheral, vascular, ocular complications and cardiac diseases. In this context, a non-enzymatic hybrid glucose biosensor was fabricated for the first time to detect glucose by immobilizing titanium oxide-manganese oxide (TiO2-Mn3O4) nanocomposite and chitosan membrane on to the surface of Pt working electrode (Pt/TiO2-Mn3O4/chitosan). TiO2-Mn3O4 nanocomposite catalyzed the oxidation of glucose to gluconolactone in the absence of glucose oxidase enzyme with high electron transfer rate, good biocompatibility and large surface coverage. Electrochemical measurements revealed the excellent sensing response of the developed biosensor towards glucose with a high sensitivity of 7.073 µA mM-1, linearity of 0.01-0.1 mM, low detection limit of 0.01 µM, reproducibility of 1.5% and stability of 98.8%. The electrochemical parameters estimated from the anodic process were subjected to linear regression models for the detection of unknown concentration of glucose in different fruit samples.

  6. Novel synthesis and characterization of Ag@TiO2 core shell nanostructure for non-enzymatic glucose sensor

    Science.gov (United States)

    T, Dayakar; Venkateswara Rao, K.; Vinodkumar, M.; Bikshalu, K.; Chakradhar, B.; Ramachandra Rao, K.

    2018-03-01

    Ag@TiO2 core-shell nano composite (ATCSNC) were synthesized by using Ocimum tenuiflorum leaves extract through a simple one-step hydrothermal route for Non-enzymatic glucose sensing material. The prepared NCs were characterized and found high crystallinity, red shift absorbance, interface-bonding parameters, rough surface and network like microstructure through XRD, Uv-vis, FTIR, SEM, and TEM. The prepared ATCSNC have been used for fabrication of glassy carbon electrode (GCE) and the same was applied to test its electro catalytic activity of glucose in 0.1 M NaOH. The promising results were recorded for ATCSNC/GCE with a high sensitivity (1968.72 μAm M-1cm-2), wide linear range (1 μM-8.1 mM), good response time (3 s), and excellent low detection limit (0.19 μM, S/N = 3). Furthermore, the designed sensor exhibits admirable stability and reproducibility, as well as attractive achievability for real sample analysis. As such, the proposed ATCSNC could be highly beneficial in the development of sustainable and eco-friendly glucose sensing devices.

  7. The Development of Non-Enzymatic Glucose Biosensors Based on Electrochemically Prepared Polypyrrole–Chitosan–Titanium Dioxide Nanocomposite Films

    Directory of Open Access Journals (Sweden)

    Ali M. A. Abdul Amir AL-Mokaram

    2017-05-01

    Full Text Available The performance of a modified electrode of nanocomposite films consisting of polypyrrole–chitosan–titanium dioxide (Ppy-CS-TiO2 has been explored for the developing a non-enzymatic glucose biosensors. The synergy effect of TiO2 nanoparticles (NPs and conducting polymer on the current responses of the electrode resulted in greater sensitivity. The incorporation of TiO2 NPs in the nanocomposite films was confirmed by X-ray photoelectron spectroscopy (XPS spectra. FE-SEM and HR-TEM provided more evidence for the presence of TiO2 in the Ppy-CS structure. Glucose biosensing properties were determined by amperommetry and cyclic voltammetry (CV. The interfacial properties of nanocomposite electrodes were studied by electrochemical impedance spectroscopy (EIS. The developed biosensors showed good sensitivity over a linear range of 1–14 mM with a detection limit of 614 μM for glucose. The modified electrode with Ppy-CS nanocomposite also exhibited good selectivity and long-term stability with no interference effect. The Ppy-CS-TiO2 nanocomposites films presented high electron transfer kinetics. This work shows the role of nanomaterials in electrochemical biosensors and describes the process of their homogeneous distribution in composite films by a one-step electrochemical process, where all components are taken in a single solution in the electrochemical cell.

  8. Poly(BCB)/Au-nanoparticles hybrid film modified electrode: Preparation, characterization and its application as a non-enzymatic sensor

    International Nuclear Information System (INIS)

    Kumar, S. Ashok; Wang, Sea-Fue; Chang, Yu-Tsern

    2010-01-01

    We report electrochemical preparation and characterization of poly-brilliant cresyl blue (Poly(BCB))/gold nanoparticles (Au-NPs) modified electrode. The Poly(BCB)/Au-NPs modified electrode has been used as an electrochemical sensor for the detection of hydrogen peroxide (H 2 O 2 ) at lower potential (- 0.2 V). The Poly(BCB)/Au-NPs film was characterized by scanning electron microscopy, Uv-visible spectroscopy (Uv-vis) and cyclic voltammetry. We have observed that, Au-NPs attached glassy carbon electrode (Au-NPs/GCE) significantly enhanced the polymerization of BCB compared to bare GCE. The Poly(BCB) film was irreversibly attached onto the Au-NPs modified electrode, the resulting hybrid film modified electrode was electrochemically active in the pH range from 2 to 11. Attachment of Poly(BCB)/Au-NPs hybrid film on the electrode surface was confirmed by Uv-vis spectra. In addition, electrocatalytic properties of the Poly(BCB)/Au-NPs/GCE towards reduction of H 2 O 2 have been investigated, and it was found that the sensitivity, reduction potential as well as the corresponding detection limit were improved as compared to the voltammetric response of the Poly(BCB)/GCE and Au-NPs/GCE. Based on this study, a non-enzymatic electrochemical sensor for the determination of H 2 O 2 has been reported. Moreover, analysis of commercial H 2 O 2 samples was performed using the proposed method and satisfactory results were obtained.

  9. Understanding non-enzymatic aminophospholipid glycation and its inhibition. Polar head features affect the kinetics of Schiff base formation.

    Science.gov (United States)

    Caldés, Catalina; Vilanova, Bartolomé; Adrover, Miquel; Muñoz, Francisco; Donoso, Josefa

    2011-08-01

    Non-enzymatic aminophospholipid glycation is an especially important process because it alters the stability of lipid bilayers and interferes with cell function and integrity as a result. However, the kinetic mechanism behind this process has scarcely been studied. As in protein glycation, the process has been suggested to involve the formation of a Schiff base as the initial, rate-determining step. In this work, we conducted a comparative kinetic study of Schiff base formation under physiological conditions in three low-molecular weight analogues of polar heads in the naturally occurring aminophospholipids O-phosphorylethanolamine (PEA), O-phospho-DL-serine (PSer) and 2-aminoethylphenethylphosphate (APP) with various glycating carbonyl compounds (glucose, arabinose and acetol) and the lipid glycation inhibitor pyridoxal 5'-phosphate (PLP). Based on the results, the presence of a phosphate group and a carboxyl group in α position respect to the amino group decrease the formation constant for the Schiff base relative to amino acids. On the other hand, esterifying the phosphate group with a non-polar substituent in APP increases the stability of its Schiff base. The observed kinetic formation constants of aminophosphates with carbonyl groups were smaller than those for PLP. Our results constitute an important contribution to understanding the competitive inhibition effect of PLP on aminophospholipid glycation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Non-Enzymatic Decomposition of Collagen Fibers by a Biglycan Antibody and a Plausible Mechanism for Rheumatoid Arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Antipova, Olga; Orgel, Joseph P.R.O. (IIT)

    2013-04-08

    Rheumatoid arthritis (RA) is a systemic autoimmune inflammatory and destructive joint disorder that affects tens of millions of people worldwide. Normal healthy joints maintain a balance between the synthesis of extracellular matrix (ECM) molecules and the proteolytic degradation of damaged ones. In the case of RA, this balance is shifted toward matrix destruction due to increased production of cleavage enzymes and the presence of (autoimmune) immunoglobulins resulting from an inflammation induced immune response. Herein we demonstrate that a polyclonal antibody against the proteoglycan biglycan (BG) causes tissue destruction that may be analogous to that of RA affected tissues. The effect of the antibody is more potent than harsh chemical and/or enzymatic treatments designed to mimic arthritis-like fibril de-polymerization. In RA cases, the immune response to inflammation causes synovial fibroblasts, monocytes and macrophages to produce cytokines and secrete matrix remodeling enzymes, whereas B cells are stimulated to produce immunoglobulins. The specific antigen that causes the RA immune response has not yet been identified, although possible candidates have been proposed, including collagen types I and II, and proteoglycans (PG's) such as biglycan. We speculate that the initiation of RA associated tissue destruction in vivo may involve a similar non-enzymatic decomposition of collagen fibrils via the immunoglobulins themselves that we observe here ex vivo.

  11. One-step preparation of silver–polyaniline nanotube composite for non-enzymatic hydrogen peroxide detection

    Energy Technology Data Exchange (ETDEWEB)

    Lorestani, Farnaz, E-mail: Farnaz.lorestani@siswa.um.edu.my; Shahnavaz, Zohreh; Nia, Pooria Moozarm; Alias, Y.; Manan, Ninie S.A., E-mail: niniemanan@um.edu.my

    2015-08-30

    Graphical abstract: - Highlights: • Silver nanoparticle-decorated polyaniline nanotube composites (AgNPs–PANINTs) have been fabricated through a one step modified method without adding any extra acids, template and surface modifier. • The sensor showed excellent selectivity, reproducibility, and stability properties. • The AgNPs–PANINTs composite that prepared with silver ammonia solution (Ag(NH{sub 3}){sub 2}OH) exhibits better electrochemical performance than the AgNPs–PANINTs composite that was prepared with silver nitrite (AgNO{sub 3}) due to smaller size and higher surface area of silver nanoparticle (AgNPs) in the composite. • The electrocatalytic activity for the reduction was strongly affected by the concentration of silver ammonia solution in the nanocomposites, with the best electrocatalytic activity observed for the composite of 6:1 volume ratios of PANI to Ag(NH{sub 3}){sub 2}OH (0.04 M). - Abstract: A modified glassy carbon electrode with silver nanoparticles–polyaniline nanotubes (AgNPs–PANINTs) composite is used as a non-enzymatic nanobiosensor for detecting hydrogen peroxide (H{sub 2}O{sub 2}). The electrocatalytic activity for the reduction was strongly affected by the concentration of silver ammonia solution in the nanocomposites, with the best electrocatalytic activity observed for the composite of 6:1 volume ratios of PANI to Ag(NH{sub 3}){sub 2}OH (0.04 M). Field emission scanning electron microscope images and their size distribution diagrams indicated that using the silver ammonia complex instead of silver nitrate caused uniform distribution of nanometer-sized silver nanoparticles with a narrow size distribution in the composite. The corresponding calibration curve for the current response showed a linear detection range of 0.1–90 mM (R{sup 2} = 0.9986), while the limit of detection was estimated to be 0.2 μM at the signal to noise ratio of 3.

  12. A non-enzymatic function of Golgi glycosyltransferases: mediation of Golgi fragmentation by interaction with non-muscle myosin IIA.

    Science.gov (United States)

    Petrosyan, Armen; Cheng, Pi-Wan

    2013-06-01

    The Golgi apparatus undergoes morphological changes under stress or malignant transformation, but the precise mechanisms are not known. We recently showed that non-muscle myosin IIA (NMIIA) binds to the cytoplasmic tail of Core 2 N-acetylglucosaminyltransferase mucus-type (C2GnT-M) and transports it to the endoplasmic reticulum for recycling. Here, we report that Golgi fragmentation induced by brefeldin A (BFA) or coatomer protein (β-COP) knockdown (KD) in Panc1-bC2GnT-M (c-Myc) cells is accompanied by the increased association of NMIIA with C2GnT-M and its degradation by proteasomes. Golgi fragmentation is prevented by inhibition or KD of NMIIA. Using multiple approaches, we have shown that the speed of BFA-induced Golgi fragmentation is positively correlated with the levels of this enzyme in the Golgi. The observation is reproduced in LNCaP cells which express high levels of two endogenous glycosyltransferases--C2GnT-L and β-galactoside α2,3 sialyltransferase 1. NMIIA is found to form complexes with these two enzymes but not Golgi matrix proteins. The KD of both enzymes or the prevention of Golgi glycosyltransferases from exiting endoplasmic reticulum reduced Golgi-associated NMIIA and decreased the BFA-induced fragmentation. Interestingly, the fragmented Golgi detected in colon cancer HT-29 cells can be restored to a compact morphology after inhibition or KD of NMIIA. The Golgi disorganization induced by the microtubule or actin destructive agent is NMIIA-independent and does not affect the levels of glycosyltransferases. We conclude that NMIIA interacts with Golgi residential but not matrix proteins, and this interaction is responsible for Golgi fragmentation induced by β-COP KD or BFA treatment. This is a novel non-enzymatic function of Golgi glycosyltransferases.

  13. Non-enzymatic antioxidant capacity (NEAC) estimated by two different dietary assessment methods and its relationship with NEAC plasma levels.

    Science.gov (United States)

    Carrión-García, Cayetano Javier; Guerra-Hernández, Eduardo J; García-Villanova, Belén; Molina-Montes, Esther

    2017-06-01

    We aimed to quantify and compare dietary non-enzymatic antioxidant capacity (NEAC), estimated using two dietary assessment methods, and to explore its relationship with plasma NEAC. Fifty healthy subjects volunteer to participate in this study. Two dietary assessment methods [a food frequency questionnaire (FFQ) and a 24-hour recall (24-HR)] were used to collect dietary information. Dietary NEAC, including oxygen radical absorbance capacity (ORAC), total polyphenols, ferric-reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity, was estimated using several data sources of NEAC content in food. NEAC status was measured in fasting blood samples using the same assays. We performed nonparametric Spearman's correlation analysis between pairs of dietary NEAC (FFQ and 24-HR) and diet-plasma NEAC, with and without the contribution of coffee's NEAC. Partial correlation analysis was used to estimate correlations regardless of variables potentially influencing these relationships. FFQ-based NEAC and 24-HR-based NEAC were moderately correlated, with correlation coefficients ranging from 0.54 to 0.71, after controlling for energy intake, age and sex. Statistically significant positive correlations were found for dietary FRAP, either derived from the FFQ or the 24-HR, with plasma FRAP (r ~ 0.30). This weak, albeit statistically significant, correlation for FRAP was mostly present in the fruits and vegetables food groups. Plasma ORAC without proteins and 24-HR-based total ORAC were also positively correlated (r = 0.35). The relationship between dietary NEAC and plasma FRAP and ORAC suggests the dietary NEAC may reflect antioxidant status despite its weak in vivo potential, supporting further its use in oxidative stress-related disease epidemiology.

  14. Vertically grown zinc oxide nanorods functionalized with ferric oxide for in vivo and non-enzymatic glucose detection

    Science.gov (United States)

    Marie, Mohammed; Manoharan, Anishkumar; Kuchuk, Andrian; Ang, Simon; Manasreh, M. O.

    2018-03-01

    An enzyme-free glucose sensor based on vertically grown zinc oxide nanorods (NRs) functionalized with ferric oxide (Fe2O3) is investigated. The well-aligned and high density ZnO NRs were synthesized on an FTO/glass substrate by a sol-gel and hydrothermal growth method. A dip-coating technique was utilized to modify the surface of the as-grown ZnO NRs with Fe2O3. The immobilized surface was coated with a layer of nafion membrane. The fabricated glucose sensor was characterized amperometrically at room temperature using three electrodes stationed in the phosphate buffer solution, where ZnO NRs/Fe2O3/nafion membrane was the sensing or working electrode, and platinum plate and silver/silver chloride were used as the counter and reference electrodes, respectively. The proposed non-enzymatic and modified glucose sensor exhibited a high sensitivity in the order of 0.052 μA cm-2 (mg/dL)-1, a lower detection limit of around 0.95 mmol L-1, a sharp and fast response time of ˜1 s, and a linear response to changes in glucose concentrations from 100-400 mg dL-1. The linear amperometric response of the sensor covers the physiological and clinical interest of glucose levels for diabetic patients. The device continues to function accurately after multiple measurements with a good reproducibility. The proposed glucose sensor is expected to be used clinically for in vivo monitoring of glucose.

  15. A non-enzymatic amperometric hydrogen peroxide sensor based on iron nanoparticles decorated reduced graphene oxide nanocomposite.

    Science.gov (United States)

    Amanulla, Baishnisha; Palanisamy, Selvakumar; Chen, Shen-Ming; Velusamy, Vijayalakshmi; Chiu, Te-Wei; Chen, Tse-Wei; Ramaraj, Sayee Kannan

    2017-02-01

    A simple and facile green process was used for the synthesis of iron nanoparticles (FeNPs) decorated reduced graphene oxide (rGO) nanocomposite by using Ipomoea pes-tigridis leaf extract as a reducing and stabilizing agent. The as-prepared rGO/FeNPs nanocomposite was characterized by transmission electron microscopy, X-ray spectroscopy and Fourier transform infrared spectroscopy. The nanocomposite was further modified on the glassy carbon electrode and used for non-enzymatic sensing of hydrogen peroxide (H 2 O 2 ). Cyclic voltammetry results reveal that rGO/FeNPs nanocomposite has excellent electro-reduction behavior to H 2 O 2 when compared to the response of FeNPs and rGO modified electrodes. Furthermore, the nanocomposite modified electrode shows 9 and 6 folds enhanced reduction current response to H 2 O 2 than that of rGO and FeNPs modified electrodes. Amperometric method was further used to quantify the H 2 O 2 using rGO/FeNPs nanocomposite, and the response was linear over the concentration ranging from 0.1μM to 2.15mM. The detection limit and sensitivity of the sensor were estimated as 0.056μM and 0.2085μAμM -1 cm -2 , respectively. The fabricated sensor also utilized for detection of H 2 O 2 in the presence of potentially active interfering species, and found high selectivity towards H 2 O 2 . Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Enzymatic and non-enzymatic antioxidant potentials of Chlorella vulgaris grown in effluent of a confectionery industry.

    Science.gov (United States)

    Kumar, R Ranjith; Rao, P Hanumantha; Subramanian, V V; Sivasubramanian, V

    2014-02-01

    Enzymatic and non-enzymatic antioxidant potentials of Chlorella vulgaris have gained considerable importance in recent decades. C. vulgaris strain highly tolerant to extreme pH variations was isolated and mass-cultivated in the wastewater from a confectionery industry. C.vulgaris showed better growth in wastewater than in improvised CFTRI medium. The microalgal biomass was then screened for the following antioxidants: peroxidase, superoxide dismutase, polyphenol oxidase, glutathione peroxidase, chlorophyll a, ascorbic acid, α-tocopherol and reduced glutathione. The total polyphenol content of the strain was also studied. The strain showed a high degree of enzymatic antioxidant activity (0.195 × 10(-5) ± 0.0072 units/cell peroxidase, 0.04125 × 10(-5) ± 0.001 units/cell superoxide dismutase, 0.2625 × 10(-5) ± 0.003 units/cell polyphenol oxidase and 0.025 × 10(-5) ± 0.003 glutathione peroxidase). The microalgal biomass also showed, per milligram weight, 0.2182 ± 0.005 μg of ascorbic acid, 0.00264 ± 0.001 μg of α-tocopherol and 0.07916 ± 0.004 μg of reduced glutathione. These results represent the possibility of using C. vulgaris grown in confectionery industry wastewater as a source of nutritious supplement, which is highly promising in terms of both economic and nutritional point of view.

  17. Unmaking Brown

    Science.gov (United States)

    Lockette, Tim

    2010-01-01

    America's schools are more segregated now than they were in the late 1960s. More than 50 years after "Brown v. Board of Education," educators need to radically rethink the meaning of "school choice." For decades at Wake County, buses would pick up public school students in largely minority communities along the Raleigh…

  18. Electrodeposition of flower-like platinum on electrophoretically grown nitrogen-doped graphene as a highly sensitive electrochemical non-enzymatic biosensor for hydrogen peroxide detection

    Energy Technology Data Exchange (ETDEWEB)

    Tajabadi, M.T. [University Malaya Centre for Ionic Liquids, Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Sookhakian, M., E-mail: m.sokhakian@gmail.com [University Malaya Centre for Ionic Liquids, Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Department of Mechanical Convergence Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 133-791, Korea (Korea, Republic of); Zalnezhad, E., E-mail: erfan@hanyang.ac.kr [Department of Mechanical Convergence Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 133-791, Korea (Korea, Republic of); Yoon, G.H. [Department of Mechanical Convergence Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 133-791, Korea (Korea, Republic of); Hamouda, A.M.S. [Mechanical and Industrial Engineering Department, College of Engineering, Qatar University, 2713, Doha (Qatar); Azarang, Majid [Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Basirun, W.J. [Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Institute of Nanotechnology & Catalysis Research, Institute of Postgraduate Studies, University Malaya, 50603 Kuala Lumpur (Malaysia); Alias, Y., E-mail: yatimah70@um.edu.my [University Malaya Centre for Ionic Liquids, Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia)

    2016-11-15

    Highlights: • Nitrogen doped graphene with different thickness by electrophoretic deposition. • The conductivity of N-graphene layer depends on the tickness. • Support of platinum shows efficient electrocatalytic performance for biosensor. • CV curves and amperometric responses improved and optimized in the presence of N-graphene. - Abstract: An efficient non-enzymatic biosensor electrode consisting of nitrogen-doped graphene (N-graphene) and platinum nanoflower (Pt NF) with different N-graphene loadings were fabricated on indium tin oxide (ITO) glass using a simple layer-by-layer electrophoretic and electrochemical sequential deposition approach. N-graphene was synthesized by annealing graphene oxide with urea at 900 °C. The structure and morphology of the as-fabricated non-enzymatic biosensor electrodes were determined using X-ray diffraction, field emission electron microscopy, transmission electron microscopy, Raman and X-ray photoelectron spectra. The as-fabricated Pt NF-N-graphene-modified ITO electrodes with different N-graphene loadings were utilized as a non-enzymatic biosensor electrode for the detection of hydrogen peroxide (H{sub 2}O{sub 2}). The behaviors of the hybrid electrodes towards H{sub 2}O{sub 2} reduction were assessed using chronoamperometry, cyclic voltammetry and electrochemical impedance spectroscopy analysis. The Pt NF-N-graphene-modified ITO electrode with a 0.05 mg ml{sup −1} N-graphene loading exhibited the lowest detection limit, fastest amperometric sensing, a wide linear response range, excellent stability and reproducibility for the non-enzymatic H{sub 2}O{sub 2} detection, due to the synergistic effect between the electrocatalytic activity of the Pt NF and the high conductivity and large surface area of N-graphene.

  19. Electrodeposition of flower-like platinum on electrophoretically grown nitrogen-doped graphene as a highly sensitive electrochemical non-enzymatic biosensor for hydrogen peroxide detection

    International Nuclear Information System (INIS)

    Tajabadi, M.T.; Sookhakian, M.; Zalnezhad, E.; Yoon, G.H.; Hamouda, A.M.S.; Azarang, Majid; Basirun, W.J.; Alias, Y.

    2016-01-01

    Highlights: • Nitrogen doped graphene with different thickness by electrophoretic deposition. • The conductivity of N-graphene layer depends on the tickness. • Support of platinum shows efficient electrocatalytic performance for biosensor. • CV curves and amperometric responses improved and optimized in the presence of N-graphene. - Abstract: An efficient non-enzymatic biosensor electrode consisting of nitrogen-doped graphene (N-graphene) and platinum nanoflower (Pt NF) with different N-graphene loadings were fabricated on indium tin oxide (ITO) glass using a simple layer-by-layer electrophoretic and electrochemical sequential deposition approach. N-graphene was synthesized by annealing graphene oxide with urea at 900 °C. The structure and morphology of the as-fabricated non-enzymatic biosensor electrodes were determined using X-ray diffraction, field emission electron microscopy, transmission electron microscopy, Raman and X-ray photoelectron spectra. The as-fabricated Pt NF-N-graphene-modified ITO electrodes with different N-graphene loadings were utilized as a non-enzymatic biosensor electrode for the detection of hydrogen peroxide (H 2 O 2 ). The behaviors of the hybrid electrodes towards H 2 O 2 reduction were assessed using chronoamperometry, cyclic voltammetry and electrochemical impedance spectroscopy analysis. The Pt NF-N-graphene-modified ITO electrode with a 0.05 mg ml −1 N-graphene loading exhibited the lowest detection limit, fastest amperometric sensing, a wide linear response range, excellent stability and reproducibility for the non-enzymatic H 2 O 2 detection, due to the synergistic effect between the electrocatalytic activity of the Pt NF and the high conductivity and large surface area of N-graphene.

  20. Can Dietary Polyphenols Prevent the Formation of Toxic Compounds from Maillard Reaction?

    Science.gov (United States)

    Del Turco, Serena; Basta, Giuseppina

    2016-01-01

    Polyphenols are functional compounds in edible vegetable and food such as tea, coffee and red wine and increasing evidence demonstrates a positive link between consumption of polyphenol-rich foods and disease prevention. In this review we have focused on the current knowledge of the potential anti-glycation effects of polyphenols, particularly in regard to their influence on Maillard reaction, a non-enzymatic reaction between amino acids and reducing sugars that contributes to the production of toxic compounds, mainly reactive carbonyl species, advanced glycation end-products (AGEs) and other toxicants. The Maillard reaction occurs in the human body during hyperglycemic condition, but it is well known as browning reaction in thermally processed foods and it is responsible for flavor and toxicant formation. Dietary polyphenols can have anti-glycation effects and actively participate in Maillard reaction, mitigating the AGE formation and the heat-induced production of toxic compounds. In a time in which the role of a healthy diet in the prevention of chronic diseases is welcome and the borderline between food and medicine is becoming very thin, an improved mechanistic knowledge of how polyphenols can function to reduce harmful and unhealthy substances is mandatory.

  1. Optimization of Maillard Reaction in Model System of Glucosamine and Cysteine Using Response Surface Methodology

    Science.gov (United States)

    Arachchi, Shanika Jeewantha Thewarapperuma; Kim, Ye-Joo; Kim, Dae-Wook; Oh, Sang-Chul; Lee, Yang-Bong

    2017-01-01

    Sulfur-containing amino acids play important roles in good flavor generation in Maillard reaction of non-enzymatic browning, so aqueous model systems of glucosamine and cysteine were studied to investigate the effects of reaction temperature, initial pH, reaction time, and concentration ratio of glucosamine and cysteine. Response surface methodology was applied to optimize the independent reaction parameters of cysteine and glucosamine in Maillard reaction. Box-Behnken factorial design was used with 30 runs of 16 factorial levels, 8 axial levels and 6 central levels. The degree of Maillard reaction was determined by reading absorption at 425 nm in a spectrophotometer and Hunter’s L, a, and b values. ΔE was consequently set as the fifth response factor. In the statistical analyses, determination coefficients (R2) for their absorbance, Hunter’s L, a, b values, and ΔE were 0.94, 0.79, 0.73, 0.96, and 0.79, respectively, showing that the absorbance and Hunter’s b value were good dependent variables for this model system. The optimum processing parameters were determined to yield glucosamine-cysteine Maillard reaction product with higher absorbance and higher colour change. The optimum estimated absorbance was achieved at the condition of initial pH 8.0, 111°C reaction temperature, 2.47 h reaction time, and 1.30 concentration ratio. The optimum condition for colour change measured by Hunter’s b value was 2.41 h reaction time, 114°C reaction temperature, initial pH 8.3, and 1.26 concentration ratio. These results can provide the basic information for Maillard reaction of aqueous model system between glucosamine and cysteine. PMID:28401086

  2. Optimization of Maillard Reaction in Model System of Glucosamine and Cysteine Using Response Surface Methodology.

    Science.gov (United States)

    Arachchi, Shanika Jeewantha Thewarapperuma; Kim, Ye-Joo; Kim, Dae-Wook; Oh, Sang-Chul; Lee, Yang-Bong

    2017-03-01

    Sulfur-containing amino acids play important roles in good flavor generation in Maillard reaction of non-enzymatic browning, so aqueous model systems of glucosamine and cysteine were studied to investigate the effects of reaction temperature, initial pH, reaction time, and concentration ratio of glucosamine and cysteine. Response surface methodology was applied to optimize the independent reaction parameters of cysteine and glucosamine in Maillard reaction. Box-Behnken factorial design was used with 30 runs of 16 factorial levels, 8 axial levels and 6 central levels. The degree of Maillard reaction was determined by reading absorption at 425 nm in a spectrophotometer and Hunter's L, a, and b values. ΔE was consequently set as the fifth response factor. In the statistical analyses, determination coefficients (R 2 ) for their absorbance, Hunter's L, a, b values, and ΔE were 0.94, 0.79, 0.73, 0.96, and 0.79, respectively, showing that the absorbance and Hunter's b value were good dependent variables for this model system. The optimum processing parameters were determined to yield glucosamine-cysteine Maillard reaction product with higher absorbance and higher colour change. The optimum estimated absorbance was achieved at the condition of initial pH 8.0, 111°C reaction temperature, 2.47 h reaction time, and 1.30 concentration ratio. The optimum condition for colour change measured by Hunter's b value was 2.41 h reaction time, 114°C reaction temperature, initial pH 8.3, and 1.26 concentration ratio. These results can provide the basic information for Maillard reaction of aqueous model system between glucosamine and cysteine.

  3. The ethylene glycol template assisted hydrothermal synthesis of Co{sub 3}O{sub 4} nanowires; structural characterization and their application as glucose non-enzymatic sensor

    Energy Technology Data Exchange (ETDEWEB)

    Khun, K., E-mail: kimleang.khun@liu.se [Department of Science and Technology, Linköping University, SE-60174 Norrköping (Sweden); Ibupoto, Z.H. [Dr M.A. Kazi Institute of Chemistry, University of Sindh Jamshoro, Sindh Jamshoro (Pakistan); Liu, X. [Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping (Sweden); Beni, V. [Biosensors and Biolelectronics Centre, Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping (Sweden); Willander, M. [Department of Science and Technology, Linköping University, SE-60174 Norrköping (Sweden)

    2015-04-15

    Highlights: • Ethylene glycol assisted Co{sub 3}O{sub 4} nanowires were synthesized by hydrothermal method. • The grown Co{sub 3}O{sub 4} nanowires were used for sensitive non-enzymatic glucose sensor. • The proposed glucose sensor shows a wide linear range with fast response. • The Co{sub 3}O{sub 4} modified electrode is a highly specific enzyme-less glucose sensor. - Abstract: In the work reported herein the ethylene glycol template assisted hydrothermal synthesis, onto Au substrate, of thin and highly dense cobalt oxide (Co{sub 3}O{sub 4}) nanowires and their characterization and their application for non-enzymatic glucose sensing are reported. The structure and composition of Co{sub 3}O{sub 4} nanowires have been fully characterized using scanning electron microscopy, X-ray diffraction, high resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The synthesized Co{sub 3}O{sub 4} nanowires resulted to have high purity and showed diameter of approximately 10 nm. The prepared Co{sub 3}O{sub 4} nanowires coated gold electrodes were applied to the non-enzymatic detection of glucose. The developed sensor showed high sensitivity (4.58 × 10{sup 1} μA mM{sup −1} cm{sup −2}), a wide linear range of concentration (1.00 × 10{sup −4}–1.2 × 10{sup 1} mM) and a detection limit of 2.65 × 10{sup −5} mM. The developed glucose sensor has also shown to be very stable and selective over interferents such as uric acid and ascorbic acid. Furthermore, the proposed fabrication process was shown to be highly reproducible response (over nine electrodes)

  4. Non-enzymatic hydrogen peroxide biosensor based on rose-shaped FeMoO{sub 4} nanostructures produced by convenient microwave-hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hongying, E-mail: liuhongying@hdu.edu.cn [College of Life Information Science & Instrument Engineering, Hangzhou Dianzi University, Zhejiang, Hangzhou 310018 (China); Gu, Chunchuan [Department of Clinical Laboratory, Hangzhou Cancer Hospital, Zhejiang, Hangzhou 310002 (China); Li, Dujuan; Zhang, Mingzhen [College of Life Information Science & Instrument Engineering, Hangzhou Dianzi University, Zhejiang, Hangzhou 310018 (China)

    2015-04-15

    Graphical abstract: A non-enzymatic H{sub 2}O{sub 2} sensor with high selectivity and sensitivity based on rose-shaped FeMoO{sub 4} synthesized by the convenient microwave-assisted hydrothermal method, was fabricated. - Highlights: • Rose-shaped FeMoO{sub 4} is synthesized within 10 min via microwave-assisted hydrothermal approach. • Non-enzymatic hydrogen peroxide biosensor based on FeMoO{sub 4} nanomaterials is fabricated. • The biosensor exhibits good performance. - Abstract: In this work, we demonstrated a simple, rapid and reliable microwave-assisted hydrothermal approach to synthesize the uniform rose-shaped FeMoO{sub 4} within 10 min. The morphologies of the synthesized materials were characterized by X-ray powder diffraction and scanning electron microscopy. Moreover, a non-enzymatic amperometric sensor for the detection of hydrogen peroxide (H{sub 2}O{sub 2}) was fabricated on the basis of the FeMoO{sub 4} as electrocatalysis. The resulting FeMoO{sub 4} exhibited high sensitivity and good stability for the detection of H{sub 2}O{sub 2}, which may be attributed to the rose-shaped structure of the material and the catalytic property of FeMoO{sub 4}. Amperometric response showed that the modified electrode had a good response for H{sub 2}O{sub 2} with a linear range from 1 μM to 1.6 mM, a detection limit of 0.5 μM (S/N = 3), high selectivity and short response time. Additionally, good recoveries of analytes in real milk samples confirm the reliability of the prepared sensor in practical applications.

  5. Non-enzymatic modifications of prostaglandin H synthase 1 affect bifunctional enzyme activity - Implications for the sensitivity of blood platelets to acetylsalicylic acid.

    Science.gov (United States)

    Kassassir, Hassan; Siewiera, Karolina; Talar, Marcin; Stec-Martyna, Emilia; Pawlowska, Zofia; Watala, Cezary

    2016-06-25

    Due to its ability to inhibit the blood platelet PGHS-1, acetylsalicylic acid (ASA, Aspirin(®)) is widely used as a preventive agent in atherothrombotic diseases. However, its beneficial effects seem to be lower in diabetic patients, suggesting that protein glycation may impair effective ASA-mediated acetylation process. On the other hand, it is proposed that ASA can prevent some of the late complications of diabetes by lowering the extent of glycation at protein free amino groups. The aim of this work was to evaluate the extents of non-enzymatic N-glycosylation (glycation) and acetylation of blood platelet PGHS-1 (COX-1) and the competition between glycation and acetylation was investigated in order to demonstrate how these two reactions may compete against platelet PGHS-1. When PGHS-1 was incubated with glycating/acetylating agents (glucose, Glu; 1,6-bisphosphofructose, 1,6-BPF; methylglyoxal, MGO, acetylsalicylic acid, ASA), the enzyme was modified in 13.4 ± 1.6, 5.3 ± 0.5, 10.7 ± 1.2 and 6.4 ± 1.1 mol/mol protein, respectively, and its activity was significantly reduced. The prior glycation/carbonylation of PGHS-1 with Glu, 1,6-BPF or MGO decreased the extent of acetylation from 6.4 ± 1.1 down to 2.5 ± 0.2, 3.6 ± 0.3 and 5.2 ± 0.2 mol/mol protein, respectively, but the enzyme still remained susceptible to the subsequent inhibition of its activity with ASA. When PGHS-1 was first acetylated with ASA and then incubated with glycating/carbonylating agents, we observed the following reductions in the enzyme modifications: from 13.4 ± 1.6 to 8.7 ± 0.6 mol/mol protein for Glu, from 5.3 ± 0.5 to 3.9 ± 0.3 mol/mol protein for 1,6-BPF and from 10.7 ± 1.2 to 7.5 ± 0.5 mol/mol protein for MGO, however subsequent glycation/carbonylation did not significantly affect PGHS-1 function. Overall, our outcomes allow to better understand the structural aspects of the chemical competition between glycation and acetylation of PGHS-1

  6. A green synthetic strategy of nickel hexacyanoferrate nanoparticals supported on the graphene substrate and its non-enzymatic amperometric sensing application

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Zhonghua, E-mail: xzh@nwnu.edu.cn [Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); He, Nan [Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Rao, Honghong [College of Chemistry and Chemical Engineering, Lanzhou City University, Lanzhou, 730070 (China); Hu, Chenxian; Wang, Xiaofen; Wang, Hui; Liu, Xiuhui [Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Lu, Xiaoquan, E-mail: luxq@nwnu.edu.cn [Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China)

    2017-02-28

    Highlights: • A sensitive non-enzymatic glucose sensor was explored by using a facile and green strategy. • Well dispersed and uniform NiHCF nanoparticles can be effectively produced by the introduction of electrochemical reduction graphene oxide films. • Metal hexacyanoferrate as a potential electron mediator was proposed and applied into non-enzymatic sensing. - Abstract: Rapid glucose detection is a key requirement for both diagnosis and treatment of diabetes. A facile and green strategy to achieve spherical-shaped nickel hexacyanoferrate (NiHCF) nanoparticals supported on electrochemical reduction graphene oxide by using electrochemical cyclic voltammetry is explored. As a sensing substrate, electrochemical reduction graphene oxide deposited on a glassy carbon electrode surface exhibited obvious positive effect on the electrodeposition of NiHCF nanoparticals with spherical structure and thus effectively improved the electrical conductivity and electrochemical sensing of the proposed amperometric sensor. Proof-concept experiments demonstrated that the proposed nanocomposites modified electrode exhibited excellent sensitivity toward glucose oxidation as well as with a satisfying detection limit of 0.11 μM. More importantly, we also explore that as a simple, green and facile method, electrochemical technology can be employed and provide a new strategy for developing GO and metal hexacyanoferrate based amperometric sensing platform toward glucose and other biomolecules.

  7. Moderate O3/O2therapy enhances enzymatic and non-enzymatic antioxidant in brain and cochlear that protects noise-induced hearing loss.

    Science.gov (United States)

    Nasezadeh, Parvaneh; Shahi, Farshad; Fridoni, Mohammadjavad; Seydi, Enayatollah; Izadi, Morteza; Salimi, Ahmad

    2017-10-01

    Mitochondrial damage and oxidative stress are known to contribute to the pathogenesis of noise-induced hearing loss (NIHL). In this study, we examined the protective effect of O 2 /O 3 mixture (ozone/oxygen) therapy against mitochondrial induced damage and oxidative stress by noise exposure in rat brain and cochlear. For this purpose, rats were divided into four groups: 1 - control group; 2 - noise-exposed group (100 dB); 3 - noise + O 2 /O 3 , and 4 - O 2 /O 3 (30 µg/ml). After 14 d, animals were anesthetised. Rat brain and cochlear tissue were removed for evaluation of the histopathological damages, oxidative stress, and mitochondrial dysfunction in both tissues. Our findings indicated that noise caused pathological damage, oxidative stress, and mitochondrial dysfunction in rat brain and cochlear. Also, daily administration of an O 2 /O 3 therapy (30 µg/ml intravenous) efficiently increased enzymatic and non-enzymatic antioxidant in brain and cochlear that this action led to inhibition of pathological damages, oxidative stress, reactive oxygen species formation, mitochondrial membrane potential (MMP) collapse, mitochondrial swelling, and cytochrome c release resulting from noise. These findings suggest that the moderate O 2 /O 3 therapy enhances the capacity of enzymatic and non-enzymatic antioxidant in brain and cochlear that protects against NIHL.

  8. Fabrication and electrochemistry characteristics of nickel-doped diamond-like carbon film toward applications in non-enzymatic glucose detection

    Science.gov (United States)

    Liu, Chi-Wen; Chen, Wei-En; Sun, Yin Tung Albert; Lin, Chii-Ruey

    2018-04-01

    This research work focused on the fabrication of nickel-doped diamond-like carbon (DLC) films and their characteristics including of surface morphology, microstructure, and electrochemical aiming at applications in non-enzymatic glucose detection. Novel nanodiamond target was employed in unbalanced magnetron radio-frequency co-sputtering process to prepared high quality Ni-doped DLC thin film at room temperature. TEM analysis reveals a highly uniform distribution of Ni crystallites in amorphous carbon matrix with fraction ranged from 3 to 11.5 at.% which is considered as active sites for the glucose detection. Our cyclic voltammetry measurements using 0.1 M H2SO4 solution demonstrated that the as-prepared Ni-doped DLC films possess large electrochemical potential window of 2.12 V, and this was also observed to be significantly reduced at high Ni doping level owing to lower sp3 fraction. The non-enzymatic glucose detection investigation indicates that the Ni-doped DLC thin film electrode prepared under 7 W of DC sputtering power on Ni target possesses good detecting performance, high stability, and high sensitivity to glucose concentration up to 10 mM, even with the existence of uric acid and ascorbic acid. The peak current was observed to be proportional to glucose concentration and scanning rate, demonstrating highly reversibility redox process of the film electrode and glucose.

  9. Protective Effect of Slforafin on the Non-Enzymatic Antioxidants and Chromosomal Aberrations When Injected with Tc 99m Tin colloid in Mice

    International Nuclear Information System (INIS)

    Alwan, I.F.; Abd-Karim, H.M.; Ahmood, A.M.; Mohamad, H.A.

    2015-01-01

    Study aims to evaluated the preventive effect of (Slforafin ) compound extracted from Broccoli plant to effect on Technetium 99m irradiated isotope user to labeled Tin colloid and used in prevent several Tin colloid changes , antioxidant Non-Enzymatic ( vitamin A,E,C ) and some of the basic elements in serum , such as (Zn, Mn, Se, Mg and Cu) and (Chromosomal Aberrations ) in the bone marrow genes of laboratory animals .Slforafin compound was analyzed by High-performance liquid chromatography technique HPLC. Treated the laboratory animals daily with, concentration (200 mg / kg) of Slforafin Broccoli extract material through mouth for one week ,then were injected with (500 μci / 0.1 ml) doses of preparation Tc 99m Tin colloidal.The results indicated that there are significant differences (p< 0.05) at the deviation level of Non- enzymatic changes and chromosomal genes and some of the basic elements in serum of the Non –treated laboratory animals with Slforafin compound compared with the group of animals treated with (Slforafin) and injected with the same radiation dose compared with the control laboratory animal groups .

  10. Effect of topical application of fluoride gel NaF 2% on enzymatic and non-enzymatic antioxidant parameters of saliva.

    Science.gov (United States)

    Leite, Mariana Ferreira; Ferreira, Nayara Ferraz D'Assumpção; Shitsuka, Caleb David Willy Moreira; Lima, Amanda Martins; Masuyama, Mônica Miyuki; Sant'Anna, Giselle Rodrigues; Yamaguti, Paula Mochidome; Polotow, Tatiana G; de Barros, Marcelo Paes

    2012-06-01

    The aim of the study was to evaluate the effect of topical fluoride gel NaF 2% application on antioxidant parameters of whole saliva from children. The saliva mechanically stimulated with parafilm was collected from 25 children (6-12 years) attending the Clinic of Paediatric Dentistry of Universidade Cruzeiro do Sul, São Paulo, Brazil, before (control group) and immediately after application of neutral fluoride gel NaF 2% (fluoride-gel group), according to the Standards for Research Using Human Subjects, Resolution 196/96 of the USA National Health Council of 10/10/1996. Afterwards, pre-post ferric-reducing antioxidant power (FRAP), trolox-equivalent antioxidant capacity (TEAC), uric acid, reduced/oxidised glutathione content (GSH/GSSG) and total peroxidase activity (TPO) were evaluated in whole saliva of both groups. All non-enzymatic antioxidant parameters were augmented by fluoride-gel NaF 2% application, whereas a notable reduction (31%) of peroxidase activity was concomitantly observed in the children's saliva (p ≤ 0.05). Nevertheless, the reducing power of saliva was kept unaltered under these circumstances (p ≤ 0.05). Despite the reduced activity of peroxidase (an important antimicrobial and antioxidant enzyme), the topical fluoride gel NaF 2% favourably stimulated the release of non-enzymatic antioxidant components of saliva, sustaining the reducing power of saliva and the natural defences of the oral cavity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. A green synthetic strategy of nickel hexacyanoferrate nanoparticals supported on the graphene substrate and its non-enzymatic amperometric sensing application

    International Nuclear Information System (INIS)

    Xue, Zhonghua; He, Nan; Rao, Honghong; Hu, Chenxian; Wang, Xiaofen; Wang, Hui; Liu, Xiuhui; Lu, Xiaoquan

    2017-01-01

    Highlights: • A sensitive non-enzymatic glucose sensor was explored by using a facile and green strategy. • Well dispersed and uniform NiHCF nanoparticles can be effectively produced by the introduction of electrochemical reduction graphene oxide films. • Metal hexacyanoferrate as a potential electron mediator was proposed and applied into non-enzymatic sensing. - Abstract: Rapid glucose detection is a key requirement for both diagnosis and treatment of diabetes. A facile and green strategy to achieve spherical-shaped nickel hexacyanoferrate (NiHCF) nanoparticals supported on electrochemical reduction graphene oxide by using electrochemical cyclic voltammetry is explored. As a sensing substrate, electrochemical reduction graphene oxide deposited on a glassy carbon electrode surface exhibited obvious positive effect on the electrodeposition of NiHCF nanoparticals with spherical structure and thus effectively improved the electrical conductivity and electrochemical sensing of the proposed amperometric sensor. Proof-concept experiments demonstrated that the proposed nanocomposites modified electrode exhibited excellent sensitivity toward glucose oxidation as well as with a satisfying detection limit of 0.11 μM. More importantly, we also explore that as a simple, green and facile method, electrochemical technology can be employed and provide a new strategy for developing GO and metal hexacyanoferrate based amperometric sensing platform toward glucose and other biomolecules.

  12. Non-enzymatic N-acetylation of Lysine Residues by AcetylCoA Often Occurs via a Proximal S-acetylated Thiol Intermediate Sensitive to Glyoxalase II

    Directory of Open Access Journals (Sweden)

    Andrew M. James

    2017-02-01

    Full Text Available Summary: Acetyl coenzyme A (AcCoA, a key intermediate in mitochondrial metabolism, N-acetylates lysine residues, disrupting and, in some cases, regulating protein function. The mitochondrial lysine deacetylase Sirtuin 3 (Sirt3 reverses this modification with benefits reported in diabetes, obesity, and aging. We show that non-enzymatic lysine N-acetylation by AcCoA is greatly enhanced by initial acetylation of a cysteine residue, followed by SN-transfer of the acetyl moiety to a nearby lysine on mitochondrial proteins and synthetic peptides. The frequent occurrence of an S-acetyl intermediate before lysine N-acetylation suggests that proximity to a thioester is a key determinant of lysine susceptibility to acetylation. The thioesterase glyoxalase II (Glo2 can limit protein S-acetylation, thereby preventing subsequent lysine N-acetylation. This suggests that the hitherto obscure role of Glo2 in mitochondria is to act upstream of Sirt3 in minimizing protein N-acetylation, thus limiting protein dysfunction when AcCoA accumulates. : James et al. show that the non-enzymatic N-acetylation of lysine residues in mitochondrial proteins frequently occurs via a proximal S-acetylated thiol intermediate. Glutathione equilibrates with this intermediate, allowing the thioesterase glyoxalase II to limit protein lysine N-acetylation. These findings expand our understanding of how protein acetylation arises. Keywords: AcetylCoA, lysine acetylation, glyoxalase

  13. The classic "brown-ring" reaction in a new medium: kinetics, mechanism, and spectroscopy of the reversible binding of nitric oxide to iron(II) in an ionic liquid.

    Science.gov (United States)

    Begel, Svetlana; Heinemann, Frank W; Stopa, Grzegorz; Stochel, Grazyna; van Eldik, Rudi

    2011-05-02

    To elucidate the applicability and properties of ionic liquids (ILs) to serve as chemical reaction media for the activation of small molecules by transition-metal complexes, detailed kinetic and mechanistic studies were performed on the reversible binding of NO to FeCl(2) dissolved in the IL 1-ethyl-3-methylimidazolium dicyanamide ([emim][dca]) as a solvent. We report, for the first time, the application of laser flash photolysis at ambient and high pressure to study the kinetics of this reaction in an IL. The kinetic data and activation parameters for the "on" and "off" reactions suggest that both processes follow a limiting dissociative (D) ligand substitution mechanism, in contrast to that reported for the same reaction in aqueous solution, where this well-known "brown-ring" reaction follows an interchange dissociative (I(d)) ligand substitution mechanism. The observed difference apparently arises from the participation of the IL anion as a N-donor ligand, as evidenced by the formation of polymeric [Fe(dca)(3)Cl](x)[emim](2x) chains in the solid state and verified by X-ray crystallography. In addition, infrared (IR), Mössbauer, and EPR spectra were recorded for the monomeric reaction product [Fe(dca)(5)NO](3-) formed in the IL, and the parameters closely resemble those of the {FeNO}(7) unit in other well-characterized nitrosyl complexes. It is concluded that its electronic structure is best described by the presence of a high-spin Fe(III) (S = 5/2) center antiferromagnetically coupled to NO(-) (S = 1), yielding the observed spin quartet ground state (S(t) = 3/2). © 2011 American Chemical Society

  14. Effect of treatment with N-acetylcysteine on non-enzymatic antioxidant reserves and lipid peroxidation in workers exposed to lead

    Directory of Open Access Journals (Sweden)

    Sławomir Kasperczyk

    2014-06-01

    Full Text Available There are no published studies examining the effects of N-acetylcysteine (NAC administration on the non-enzymatic defence systems in humans exposed to lead. In view of this, it was decided to measure the levels of uric acid (UA, albumin, bilirubin and alpha-tocopherol before and after treatment with NAC. An estimation was also made of the degree of oxidative stress by measuring the ferric reducing ability of plasma (FRAP, the levels of conjugated dienes (CD and lipid hydroperoxides (LHP. Male employees who worked with lead were randomized into two groups. The first group included workers who were not administered any drugs (n=49, while the second group (n=122 consisted of workers who were treated with NAC at three different doses (200 mg, 400 mg and 800 mg for 12 weeks. The administration of NAC (400 mg, 800 mg resulted in significant decreases in the LHP levels. Similarly, a strong tendency toward lower levels of CD was observed in the same groups. The UA levels were significantly lower only in the group receiving the 200 mg dose of NAC. However, the alpha-tocopherol levels were significantly elevated after treatment with NAC (400 mg, 800 mg. NAC administration did not significantly affect the levels of bilirubin and albumin, but a tendency toward higher values was observed for FRAP. NAC reduced the extent of lipid peroxidation in a dose-dependent manner. Elevated concentrations of alpha-tocopherol may have enhanced the beneficial effects of NAC. Treatment with NAC may contribute to the restoration of non-enzymatic antioxidant reserves when administered to lead-exposed workers.

  15. A novel hierarchical 3D N-Co-CNT@NG nanocomposite electrode for non-enzymatic glucose and hydrogen peroxide sensing applications.

    Science.gov (United States)

    Balamurugan, Jayaraman; Thanh, Tran Duy; Karthikeyan, Gopalsamy; Kim, Nam Hoon; Lee, Joong Hee

    2017-03-15

    A novel 3D nanocomposite of nitrogen doped Co-CNTs over graphene sheets (3D N-Co-CNT@NG) have been successfully fabricated via a simple, scalable and one-step thermal decomposition method. This 3D hierarchical nanostructure provides an admirable conductive network for effective charge transfer and avoids the agglomeration of NG matrices, which examine direct as well as non-enzymatic responses to glucose oxidation and H 2 O 2 reduction at a low potential. The novel electrode showed excellent electrochemical performance towards glucose oxidation, with high sensitivity of 9.05μAcm -2 mM -1 , a wide linear range from 0.025 to 10.83mM, and a detection limit of 100nM with a fast response time of less than 3s. Furthermore, non-enzymatic H 2 O 2 sensors based on the 3D N-Co-CNT@NG electrode exhibited high sensitivity (28.66μAmM -1 cm -2 ), wide linear range (2.0-7449μM), low detection limit of 2.0μM (S/N=3), excellent selectivity, decent reproducibility and long term stability. Such outstanding electrochemical performance can be endorsed to the large electroactive surface area, unique porous architecture, highly conductive networks, and synergistic interaction between N-Co-CNTs and nitrogen doped graphene (NG) in the novel 3D nanocomposite. This facile, cost-effective, sensitive, and selective glucose as well as H 2 O 2 sensors are also proven to be appropriate for the detection of glucose as well as H 2 O 2 in human serum. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Non-enzymatic hydrogen peroxide detection at NiO nanoporous thin film- electrodes prepared by physical vapor deposition at oblique angles

    International Nuclear Information System (INIS)

    Salazar, Pedro; Rico, Victor; González-Elipe, Agustín R.

    2017-01-01

    Highlights: • A non-enzymatic sensor for H 2 O 2 detection based on nickel thin film is reported. • Nanostructured nickel thin films are prepared by physical vapor deposition at oblique angles. • Main analytical parameters were obtained under optimal operation conditions. • Sensors depict an outstanding selectivity and a high stability. • Sensors are successfully used to determine H 2 O 2 in antiseptic solutions. - Abstract: In this work we report a non-enzymatic sensor for hydrogen peroxide (H 2 O 2 ) detection based on nanostructured nickel thin films prepared by physical vapor deposition at oblique angles. Porous thin films deposited on ITO substrates were characterized by X-ray diffraction analysis, scanning electron microcopy (SEMs), X-ray photoelectron spectroscopy (XPS) and electrochemical techniques such as Cyclic Voltammetry (CV) and Constant Potential Amperometry (CPA). The microstructure of the thin films consisted of inclined and separated Ni nanocolumns forming a porous thin layer of about 500 nm thickness. Prior to their use, the films surface was electrochemically modified and the chemical state studied by CV and XPS analysis. These techniques also showed that Ni 2+ /Ni 3+ species were involved in the electrochemical oxidation and detection of H 2 O 2 in alkaline medium. Main analytical parameters such as sensitivity (807 mA M −1 cm −2 ), limit of detection (3.22 μM) and linear range (0.011–2.4 mM) were obtained under optimal operation conditions. Sensors depicted an outstanding selectivity and a high stability and they were successfully used to determine H 2 O 2 concentration in commercial antiseptic solutions.

  17. 3D-copper oxide and copper oxide/few-layer graphene with screen printed nanosheet assembly for ultrasensitive non-enzymatic glucose sensing

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhimei [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin, 300384 (China); Advanced Materials and Printed Electronics Center, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin, 300384 (China); Pan, Peng, E-mail: panpeny@163.com [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin, 300384 (China); Advanced Materials and Printed Electronics Center, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin, 300384 (China); Liu, Xuewen [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin, 300384 (China); Advanced Materials and Printed Electronics Center, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin, 300384 (China); Yang, Zhengchun; Wei, Jun [Advanced Materials and Printed Electronics Center, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin, 300384 (China); Wei, Zhen, E-mail: weizhenxinxi@163.com [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin, 300384 (China); Advanced Materials and Printed Electronics Center, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin, 300384 (China)

    2017-02-01

    Screen-printed copper oxide (CuO) and CuO/few-layer graphene on graphite electrodes were used to fabricate the ultrasensitive nonenzymatic glucose biosensors. Flower-like CuO and flower-like CuO/few-layer graphene composites were prepared by screen-printing method and characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HETEM). On the basis of their cyclic voltammetry (CV) and chronoamperometry results, it was concluded that the addition of graphene to CuO significantly improved the performance of the fabricated glucose sensors, exhibiting high and reproducible sensitivity of 3120 μAmM{sup −1} cm{sup −2} with three linear ranges from 4 μM to 13.5 mM and the detection limit of 4 μM (S/N = 3) in a fast response time of 2 s. In addition, the fabricated sensors could effectively avoid the disturbance by interferents, such as Ascorbic Acid (AA), Uric Acid (UA), and Dopamine (DA). Most importantly, the testing results of real blood serum samples demonstrated that the electrodes were applicable and acceptable for the determination of glucose concentrations in human serum. The efficiencies of two non-enzymatic glucose biosensors for glucose determination were comparable with that of a commercial enzymatic sensor. - Highlights: • The method 2D nanosheet turns to 3D microflower by using screen printing was proposed. • Few-layer graphene added improved the sensor’s performance on base of CuO functional material. • Two ultrasensitive non-enzymatic glucose sensors were successfully fabricated. • The proposed sensor shows a high sensitivity of 3120 μA mM{sup −1} cm{sup −2}.

  18. Nuclear excitations and reaction mechanisms. Progress report, 1 November 1979-30 September 1980. [Dept. of Physics, Brown Univ. , Providence, Rhode Island

    Energy Technology Data Exchange (ETDEWEB)

    1980-10-01

    Among the topics investigated were the following: photon scattering and consistency condition between seagull quadrupole terms and the absorption sum rule; Raman scattering to negative-parity states; nonlocal terms due to exchange and retardation effects in charge-transfer reactions; consistency and meaning of various approximate channel coupling array equations; derivation of equations used in empirical nuclear reaction analyses; multicluster, n-particle scattering theory; converged molecular bound state calculations; consistency of approximate channel coupling array equations; derivations of equations used in empirical nuclear reaction analyses; and WKB-type approximation in angular momenta for central potentials. References to publications are given.

  19. Identification of Maillard reaction induced chemical modifications on Ara h 1

    Science.gov (United States)

    The Maillard reaction is a non-enzymatic glycation reaction between proteins and reducing sugars that can modify nut allergens during thermal processing. These modifications can alter the structural and immunological properties of these allergens, and may result in increased IgE binding. Here, we ...

  20. Non-enzymatic glycation enhances human serum albumin binding capacity to sodium fluorescein at room temperature: A spectroscopic analysis.

    Science.gov (United States)

    Fatima, Sadaf; Anwar, Tamanna; Ahmad, Nabeel; Islam, Asimul; Sen, Priyankar

    2017-06-01

    Sodium fluorescein (SF) is a fluorescent tracer dye used extensively in diagnostic tools in the field of Ophthalmology, particularly in intravenous fluorescein angiography (IVFA). The binding of SF to human serum albumin (HSA) has been predicted by molecular docking and investigated by circular dichroism (CD) and fluorescence spectroscopy with or without glycation at temperatures 296, 301, and 310K. The binding parameters were calculated by quenching of emission spectrum of a constant concentration of SF (2μmol/l) at 513nm against increasing concentrations of glycated or unmodified HSA as quencher starting from stoichiometry ratio of 1:1. The HSA-SF interaction found to be a static binding. The Stern-Volmer constants (Ksv) were in the range of ~10 4 M -1 and other thermodynamic parameters like enthalpy (ΔH°), free energy (ΔG°) and entropy (ΔS°) are similar to albumin ligand bindings reported by previous workers. The interactions were found to be spontaneous, irrespective of temperature or glycation. Glycated HSA is clinically used to monitor unstable glycemic controls in diabetic patients. A 39% increase in binding affinity (log K) and free energy (ΔG°) is reported on glycation at 310K (room temperature), which may be important in the SF based angiographies. On glycation HSA-SF binding appears to change from an enthalpy-driven to an entropy-driven reaction. SF shows best binding to FA binding site III of HSA, which also overlaps with drug binding site II of subdomain IIIA. Leu430 seems to play a pivotal role in the interaction. Copyright © 2017. Published by Elsevier B.V.

  1. Co3O4 based non-enzymatic glucose sensor with high sensitivity and reliable stability derived from hollow hierarchical architecture

    Science.gov (United States)

    Tian, Liangliang; He, Gege; Cai, Yanhua; Wu, Shenping; Su, Yongyao; Yan, Hengqing; Yang, Cong; Chen, Yanling; Li, Lu

    2018-02-01

    Inspired by kinetics, the design of hollow hierarchical electrocatalysts through large-scale integration of building blocks is recognized as an effective approach to the achievement of superior electrocatalytic performance. In this work, a hollow, hierarchical Co3O4 architecture (Co3O4 HHA) was constructed using a coordinated etching and precipitation (CEP) method followed by calcination. The resulting Co3O4 HHA electrode exhibited excellent electrocatalytic activity in terms of high sensitivity (839.3 μA mM-1 cm-2) and reliable stability in glucose detection. The high sensitivity could be attributed to the large specific surface area (SSA), ample unimpeded penetration diffusion paths and high electron transfer rate originating from the unique two-dimensional (2D) sheet-like character and hollow porous architecture. The hollow hierarchical structure also affords sufficient interspace for accommodation of volume change and structural strain, resulting in enhanced stability. The results indicate that Co3O4 HHA could have potential for application in the design of non-enzymatic glucose sensors, and that the construction of hollow hierarchical architecture provides an efficient way to design highly active, stable electrocatalysts.

  2. Ternary nanohybrid of reduced graphene oxide-nafion@silver nanoparticles for boosting the sensor performance in non-enzymatic amperometric detection of hydrogen peroxide.

    Science.gov (United States)

    Yusoff, Norazriena; Rameshkumar, Perumal; Mehmood, Muhammad Shahid; Pandikumar, Alagarsamy; Lee, Hing Wah; Huang, Nay Ming

    2017-01-15

    A sensitive and novel electrochemical sensor was developed for the detection of hydrogen peroxide (H 2 O 2 ) using a reduced graphene oxide-nafion@silver6 (rGO-Nf@Ag6) nanohybrid modified glassy carbon electrode (GC/rGO-Nf@Ag6). The GC/rGO-Nf@Ag6 electrode exhibited an excellent electrochemical sensing ability for determining H 2 O 2 with high sensitivity and selectivity. The detection limit of the electrochemical sensor using the GC/rGO-Nf@Ag6 electrode for H 2 O 2 determination was calculated to be 5.35×10 -7 M with sensitivity of 0.4508µAµM -1 . The coupling between rGO-Nf with silver nanoparticles (AgNPs) significantly boosted the electroanalytical performance by providing more active area for analyte interaction, thereby allowing more rapid interfacial electron transfer process. The interfering effect on the current response of H 2 O 2 was studied and the results revealed that the sensor electrode exhibited an excellent immunity from most common interferents. The proposed non-enzymatic electrochemical sensor was used for determining H 2 O 2 in apple juice, and the sensor electrode provided satisfactory results with reliable recovery values. These studies revealed that the novel GC/rGO-Nf@Ag6 sensor electrode could be a potential candidate for the detection of H 2 O 2 . Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Facile fabrication of chitosan-calcium carbonate nanowall arrays and their use as a sensitive non-enzymatic organophosphate pesticide sensor

    Science.gov (United States)

    Gong, Jingming; Zhang, Wei; Liu, Ting; Zhang, Lizhi

    2011-08-01

    Novel nanowall arrays of CaCO3-chitosan (CaCO3-chi) were deposited onto a cathodic substrate by a facile one-step electrodeposition approach. Results demonstrate that chitosan plays an important role in the formation of nanowall arrays. Freestanding well-aligned CaCO3-chi nanowall arrays were observed to be uniformly distributed over the whole substrate with a lateral dimension in the micrometre size and an average pore size of ~400 nm. The as-formed CaCO3-chi nanowall arrays featuring interlaced porous network architecture, large surface area, and open boundaries, are highly efficient in the capture of organophosphate pesticides (OPs). Combined with stripping voltammetry, a highly sensitive non-enzymatic OPs sensor was fabricated using the prepared CaCO3-chi nanowall arrays for solid phase extraction (SPE). The detection limit for methyl parathion (MP) in aqueous solutions was determined to be 0.8 ng mL-1 (S/N = 3). The resulting sensor made of novel CaCO3-chi nanowall arrays exhibits good reproducibility and acceptable stability. This work not only provides a facile and effective route for the preparation of CaCO3-chi nanowall arrays, but also offers a new promising protocol for OPs analysis.

  4. Non-enzymatic N-acetylation of Lysine Residues by AcetylCoA Often Occurs via a Proximal S-acetylated Thiol Intermediate Sensitive to Glyoxalase II.

    Science.gov (United States)

    James, Andrew M; Hoogewijs, Kurt; Logan, Angela; Hall, Andrew R; Ding, Shujing; Fearnley, Ian M; Murphy, Michael P

    2017-02-28

    Acetyl coenzyme A (AcCoA), a key intermediate in mitochondrial metabolism, N-acetylates lysine residues, disrupting and, in some cases, regulating protein function. The mitochondrial lysine deacetylase Sirtuin 3 (Sirt3) reverses this modification with benefits reported in diabetes, obesity, and aging. We show that non-enzymatic lysine N-acetylation by AcCoA is greatly enhanced by initial acetylation of a cysteine residue, followed by SN-transfer of the acetyl moiety to a nearby lysine on mitochondrial proteins and synthetic peptides. The frequent occurrence of an S-acetyl intermediate before lysine N-acetylation suggests that proximity to a thioester is a key determinant of lysine susceptibility to acetylation. The thioesterase glyoxalase II (Glo2) can limit protein S-acetylation, thereby preventing subsequent lysine N-acetylation. This suggests that the hitherto obscure role of Glo2 in mitochondria is to act upstream of Sirt3 in minimizing protein N-acetylation, thus limiting protein dysfunction when AcCoA accumulates. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Non-Enzymatic Electrochemical Sensing of Malathion Pesticide in Tomato and Apple Samples Based on Gold Nanoparticles-Chitosan-Ionic Liquid Hybrid Nanocomposite

    Directory of Open Access Journals (Sweden)

    Gulcin Bolat

    2018-03-01

    Full Text Available Malathion (MLT is an organophosphorous type pesticide and having seriously high toxicity and electrochemical platforms for rapid, simple, inexpensive and sensitive determination of pesticides is still a special concern. This paper describes a simple preparation of a composite film consisting of ionic liquid (IL, chitosan (CS and electrochemically synthesized gold nanoparticles (AuNPs on single use pencil graphite electrodes (PGEs. The microscopic and electrochemical characterization of AuNP-CS-IL/PGE was studied using scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. This fabricated surface was then explored for the first time as a sensing matrix for the non-enzymatic electrochemical sensing of malathion by cyclic voltammetry and square wave voltammetry measurements. The proposed AuNP-CS-IL/PGE showed excellent characteristics and possessed remarkable affinity for malathion. The voltammetric current response exhibited two linear dynamic ranges, 0.89–5.94 nM and 5.94–44.6 nM reflecting two binding sites, with a detection limit of 0.68 nM. The method was applied in real sample analysis of apple and tomato. The results demonstrate the feasibility of AuNP-CS-IL-modified electrodes for simple, fast, ultrasensitive and inexpensive detection of MLT.

  6. Plasmodesmata of brown algae

    OpenAIRE

    Terauchi, Makoto; Nagasato, Chikako; Motomura, Taizo

    2014-01-01

    Plasmodesmata (PD) are intercellular connections in plants which play roles in various developmental processes. They are also found in brown algae, a group of eukaryotes possessing complex multicellularity, as well as green plants. Recently, we conducted an ultrastructural study of PD in several species of brown algae. PD in brown algae are commonly straight plasma membrane-lined channels with a diameter of 10?20?nm and they lack desmotubule in contrast to green plants. Moreover, branched PD ...

  7. Brown adipocyte function

    DEFF Research Database (Denmark)

    Winther, Sally

    that glycolytic flux is important for β-adrenergically induced oxygen consumption, and highlights that glucose oxidation serves multiple purposes in brown adipocytes. Together the studies describe novel aspects of glucose consumption adding to the understanding of substrate oxidation in activated brown adipocytes....... Taken together the research presented in this thesis describes novel aspects of BAT physiology, adding to the growing understanding of brown adipocyte activation and fuel preferences....

  8. Unraveling the mechanism responsible for the contrasting tolerance of Synechocystis and Synechococcus to Cr(VI): Enzymatic and non-enzymatic antioxidants

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Alka [Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Ballal, Anand, E-mail: aballal@barc.gov.in [Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 40085 (India)

    2015-07-15

    Highlights: • Cr(VI) accumulation generates higher ROS in Synechocystis than in Synechococcus. • Synechococcus exhibits better photosynthetic activity in response to Cr(VI). • Synechococcus has higher enzymatic/non-enzymatic antioxidants than Synechocystis. • Synechococcus shows better tolerance to other oxidative stresses than Synechocystis. • Differential detoxification of ROS is responsible for the contrasting tolerance to Cr(VI) - Abstract: Two unicellular cyanobacteria, Synechocystis and Synechococcus, showed contrasting tolerance to Cr(VI); with Synechococcus being 12-fold more tolerant than Synechocystis to potassium dichromate. The mechanism responsible for this differential sensitivity to Cr(VI) was explored in this study. Total content of photosynthetic pigments as well as photosynthetic activity decreased at lower concentration of Cr(VI) in Synechocystis as compared to Synechococcus. Experiments with {sup 51}Cr showed Cr to accumulate intracellularly in both the cyanobacteria. At lower concentrations, Cr(VI) caused excessive ROS generation in Synechocystis as compared to that observed in Synechococcus. Intrinsic levels of enzymatic antioxidants, i.e., superoxide dismutase, catalase and 2-Cys-peroxiredoxin were considerably higher in Synechococcus than Synechocystis. Content of total thiols (both protein as well as non-protein) and reduced glutathione (GSH) was also higher in Synechococcus as compared to Synechocystis. This correlated well with higher content of carbonylated proteins observed in Synechocystis than Synechococcus. Additionally, in contrast to Synechocystis, Synechococcus exhibited better tolerance to other oxidative stresses like high intensity light and H{sub 2}O{sub 2}. The data indicate that the disparity in the ability to detoxify ROS could be the primary mechanism responsible for the differential tolerance of these cyanobacteria to Cr(VI)

  9. A novel non-enzymatic glucose sensor based on the modification of carbon paste electrode with CuO nanoflower: Designing the experiments by response surface methodology (RSM).

    Science.gov (United States)

    Amani-Beni, Zahra; Nezamzadeh-Ejhieh, Alireza

    2017-10-15

    A non enzymatic modified electrode was constructed based on the modification of carbon paste electrode with CuO nanoflower (CuO-CPE). The raw and modified samples were characterized by XRD, TEM, SEM-EDX and X-ray mapping techniques. The proposed CuO-CPE showed a well voltammetric peak pair in cyclic voltammetry which of peak currents were decreased in the presence of glucose. Hence, this decrease in peak current was used for voltammetric determination of glucose. To evaluate interactions between the influencing variables, experiments were designed by response surface methodology (RSM) and the results showed CuO%-pH have the most effect on square wave voltammetric response. The best response was obtained in a run including 20% CuO modifier, pH 3.6, amplitude 0.106V, step potential 0.0074V and frequency 17.75Hz. Calibration curve was constructed and a linear response between ΔIp (difference of peak current in the presence and absence of glucose in SqW voltammograms) and glucose concentration was obtained in concentration range from 0.06 to 10mmolL -1 [calibration equation: ΔI (μA)=91.35 C glucose +523.12, R 2 =0.9967] with detection and quantification limits of 7.49×10 -10 and 2.49×10 -9 molL -1 , respectively. The modified electrode can be used satisfactory in determination of glucose in real samples such as human blood serum. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Laurie M Brown

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. Laurie M Brown. Articles written in Resonance – Journal of Science Education. Volume 16 Issue 9 September 2011 pp 874-878 Personal Reflections. To Have Been a Student of Richard Feynman · Laurie M Brown · More Details Fulltext PDF ...

  11. A novel fluorescence microscopy approach to estimate quality loss of stored fruit fillings as a result of browning.

    Science.gov (United States)

    Cropotova, Janna; Tylewicz, Urszula; Cocci, Emiliano; Romani, Santina; Dalla Rosa, Marco

    2016-03-01

    The aim of the present study was to estimate the quality deterioration of apple fillings during storage. Moreover, a potentiality of novel time-saving and non-invasive method based on fluorescence microscopy for prompt ascertainment of non-enzymatic browning initiation in fruit fillings was investigated. Apple filling samples were obtained by mixing different quantities of fruit and stabilizing agents (inulin, pectin and gellan gum), thermally processed and stored for 6-month. The preservation of antioxidant capacity (determined by DPPH method) in apple fillings was indirectly correlated with decrease in total polyphenols content that varied from 34±22 to 56±17% and concomitant accumulation of 5-hydroxymethylfurfural (HMF), ranging from 3.4±0.1 to 8±1mg/kg in comparison to initial apple puree values. The mean intensity of the fluorescence emission spectra of apple filling samples and initial apple puree was highly correlated (R(2)>0.95) with the HMF content, showing a good potentiality of fluorescence microscopy method to estimate non-enzymatic browning. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Gibberellin-like effects of KAR1 on dormancy release of Avena fatua caryopses include participation of non-enzymatic antioxidants and cell cycle activation in embryos.

    Science.gov (United States)

    Cembrowska-Lech, Danuta; Kępczyński, Jan

    2016-02-01

    The induction of dormancy release and germination of Avena fatua caryopses by KAR 1 involves ABA degradation to phaseic acid. Both, KAR 1 and GA 3 , control the AsA-GSH cycle, DNA replication and accumulation of β-tubulin in embryos before caryopses germination. Avena fatua caryopses cannot germinate in darkness at 20 °C because of dormancy, but karrikinolide-1 (KAR1), a compound in plant-derived smoke, and gibberellic acid (GA3) induced an almost complete germination. The radicle protrusion through the coleorhiza was preceded by increased water uptake, rupture of coat, increased embryo size and coleorhiza length as well as coleorhiza protrusion through covering structures. The stimulatory effect of KAR1 was correlated with the reduced content of abscisic acid (ABA) and an increase in phaseic acid (PA) in embryos from caryopses before coleorhiza protrusion. Two non-enzymatic antioxidants, ascorbate (AsA) and reduced glutathione (GSH), did not affect the germination of dormant caryopses, but in the presence of KAR1 or GA3 they only slightly delayed the germination. The stimulatory effect of KAR1 or GA3 on the final germination percentage was markedly antagonized by lycorine, an AsA biosynthesis inhibitor. KAR1 and GA3 applied during caryopses imbibition resulted in increases of AsA, dehydroascorbate (DHA) and GSH, but reduced the embryos' oxidized glutathione (GSSG) content. Furthermore, both KAR1 and GA3 induced an additional ascorbate peroxidase (APX) isoenzyme and increased the glutathione reductase (GR) activity. Both compounds stimulated β-tubulin accumulation in radicle+coleorhiza (RC) and plumule+coleoptile (PC), and enhanced the transition from G1 to S and also from S to G2 phases. The comparison of the effects produced by KAR1 and GA3  shows a similar action; thus the KAR1 effect may not be specific. The study provides new data regarding the mechanism with which KAR1, a representative of a novel class of plant growth regulators, regulates dormancy and

  13. MnO{sub x}/C nanocomposite: An insight on high-performance supercapacitor and non-enzymatic hydrogen peroxide detection

    Energy Technology Data Exchange (ETDEWEB)

    Ahuja, Preety, E-mail: drpreetyahuja@gmail.com [Department of Chemistry, Jamia Hamdard, Delhi 110062 (India); Kumar Ujjain, Sanjeev [Department of Physics, Indian Institute of Technology, Kanpur, UP 208016 (India); Kanojia, Rajni [Department of Chemistry, Shivaji College, University of Delhi, Delhi 110027 (India)

    2017-05-15

    Graphical abstract: In-situ inclusion of carbon matrix during growth of MnO{sub x} nanoparticles resulted in MnO{sub x}/C nanocomposite with enhanced electronic diffusion leading to high energy/power densities supercapacitor and highly sensitive H{sub 2}O{sub 2} sensor. - Highlights: • MnO{sub x}/C, synthesized via microemulsion method, is electrochemically investigated towards supercapacitor and sensing applications. • In-situ inclusion of conducting carbon in manganese oxide enhances the network conductivity facilitating the charge transfer process. • It provides high energy and power density, 31.6 Wh kg{sup −1} and 3.8 kW kg{sup −1} respectively, with short relaxation time ∼3 ms for fabricated cell. • MnO{sub x}/C as sensor, exhibits excellent catalytic activity toward H{sub 2}O{sub 2} oxidation and offer high sensitivity with low detection limit. - Abstract: In this work, we have used microemulsion method for synthesis of MnO{sub x}/C nanocomposite and investigated its electrochemical properties via fabrication of supercapacitor and non-enzymatic hydrogen peroxide (H{sub 2}O{sub 2}) sensor. In-situ inclusion of conducting carbon in manganese oxide (MnO{sub x}/C) enhances the network conductivity facilitating the charge transfer process which is beneficial for supercapacitor and sensing applications. MnO{sub x}/C provides high energy and power density, 31.6 Wh kg{sup −1} and 3.8 kW kg{sup −1} respectively and short relaxation time ∼3 ms for fabricated cell (MnO{sub x}/C//MnO{sub x}/C) endowing excellent power delivery capacity. Furthermore, MnO{sub x}/C as sensor, exhibits excellent catalytic activity toward the oxidation of H{sub 2}O{sub 2} and shows high sensitivity (0.37 mA mM{sup −1} cm{sup −2}) with low detection limit (0.5 μM at an S/N of 3). Hence, this study provides new avenue for high performance supercapacitor and H{sub 2}O{sub 2} detection.

  14. Brown Recluse Spider

    Science.gov (United States)

    ... to a group of spiders commonly known as violin spiders or fiddlebacks. The characteristic fiddle-shaped pattern ... 4-19.1mm) • Color: Golden brown • A dark violin/fiddle shape (see top photo) is located on ...

  15. Understanding Brown Dwarf Variability

    Science.gov (United States)

    Marley, Mark S.

    2013-01-01

    Surveys of brown dwarf variability continue to find that roughly half of all brown dwarfs are variable. While variability is observed amongst all types of brown dwarfs, amplitudes are typically greatest for L-T transition objects. In my talk I will discuss the possible physical mechanisms that are responsible for the observed variability. I will particularly focus on comparing and contrasting the effects of changes in atmospheric thermal profile and cloud opacity. The two different mechanisms will produce different variability signatures and I will discuss the extent to which the current datasets constrain both mechanisms. By combining constraints from studies of variability with existing spectral and photometric datasets we can begin to construct and test self-consistent models of brown dwarf atmospheres. These models not only aid in the interpretation of existing objects but also inform studies of directly imaged giant planets.

  16. Field Brown Dwarfs & GAIA

    Science.gov (United States)

    Haywood, M.; Jordi, C.

    Because of their very red colours and intrinsic faintness, field brown dwarfs will represent a small but valuable subset of the GAIA catalogue. The return of the astrometric satellite is expected to be important because of the inherent difficulty of obtaining good parallaxes in general and for this class of objects in particular. Our first estimates show that, due to the photometric sensitivity of the astrometric CCD (ASM1) towards relatively blue objects, GAIA is unlikely to detect field brown dwarfs that have not been already seen is previous near-IR surveys, to the notable exception of the galactic plane region. The real advantage of GAIA over ground-based surveys will be the very accurate (to within a few percents) astrometric data for a few thousands brown dwarfs. These data should permit a detailed mapping of the transition region between stellar and substellar regimes, together with the kinematical and density patterns of the youngest brown dwarfs in our neighbourhood.

  17. Transcriptomics in brown algae

    OpenAIRE

    Heinrich, Sandra

    2015-01-01

    Brown algae are distributed worldwide on rocky shores. They are importenet components of ecosystems, they provide habitat, shelter and serve as nurseries for various marine organisms. The geographic as well as depth distribution of macroalgae is constrained by abiotic factors, especially light and temperature. It is therefore likely that due to the global change, distribution patterns of these organisms will change. In this work the molecular acclimation of two prominent brown macroalgae, Sac...

  18. Plasmodesmata of brown algae.

    Science.gov (United States)

    Terauchi, Makoto; Nagasato, Chikako; Motomura, Taizo

    2015-01-01

    Plasmodesmata (PD) are intercellular connections in plants which play roles in various developmental processes. They are also found in brown algae, a group of eukaryotes possessing complex multicellularity, as well as green plants. Recently, we conducted an ultrastructural study of PD in several species of brown algae. PD in brown algae are commonly straight plasma membrane-lined channels with a diameter of 10-20 nm and they lack desmotubule in contrast to green plants. Moreover, branched PD could not be observed in brown algae. In the brown alga, Dictyota dichotoma, PD are produced during cytokinesis through the formation of their precursor structures (pre-plasmodesmata, PPD). Clustering of PD in a structure termed "pit field" was recognized in several species having a complex multicellular thallus structure but not in those having uniseriate filamentous or multiseriate one. The pit fields might control cell-to-cell communication and contribute to the establishment of the complex multicellular thallus. In this review, we discuss fundamental morphological aspects of brown algal PD and present questions that remain open.

  19. A highly sensitive non-enzymatic glucose sensor based on nickel and multi-walled carbon nanotubes nanohybrid films fabricated by one-step co-electrodeposition in ionic liquids

    International Nuclear Information System (INIS)

    Sun Aili; Zheng Jianbin; Sheng Qinglin

    2012-01-01

    Graphical abstract: Cyclic voltammograms of Ni–MWNTs/GCE at different concentrations of glucose. Highlights: ► Ni –MWNT nanohybrid film was successfully synthesized and characterized by SEM and EDS. ► The mechanism of glucose at Ni –MWNT nanohybrid film was evaluated and the upper glucose concentration limit produced a linear response of 17.5 mM. ► Simple of preparation and good analytical response made nanohybrid films a promising sensor material for non-enzymatic glucose sensing in routine analysis. - Abstract: In this paper, nickel was combined with multi-walled carbon nanotubes (Ni–MWNTs) to fabricate nanohybrid films on a conventional glassy carbon electrode using simultaneous electrodeposition of NiCl 2 and the MWNTs in ionic liquids (ILs). The morphologies and elemental compositions of the nanohybrid films were investigated with scanning electron microscopy and energy dispersive spectroscopy. A novel non-enzymatic glucose sensor based on the Ni–MWNT nanohybrid film-modified glassy carbon electrode was described, and its electrochemical behaviors were investigated. The proposed sensor exhibited high electrocatalytic activity and good response to glucose. Under optimal conditions, the sensor showed high sensitivity (67.2 μA mM −1 cm −2 ), rapid response time (<2 s) and a low detection limit (0.89 μM; signal/noise ratio of 3). In particular, the upper glucose concentration limit produced a linear response of 17.5 mM. Thus, the Ni–MWNT nanohybrid films represent promising sensor materials for non-enzymatic glucose sensing in routine analyses.

  20. High-performance non-enzymatic catalysts based on 3D hierarchical hollow porous Co3O4nanododecahedras in situ decorated on carbon nanotubes for glucose detection and biofuel cell application.

    Science.gov (United States)

    Wang, Shiyue; Zhang, Xiaohua; Huang, Junlin; Chen, Jinhua

    2018-03-01

    In this work, high-performance non-enzymatic catalysts based on 3D hierarchical hollow porous Co 3 O 4 nanododecahedras in situ decorated on carbon nanotubes (3D Co 3 O 4 -HPND/CNTs) were successfully prepared via direct carbonizing metal-organic framework-67 in situ grown on carbon nanotubes. The morphology, microstructure, and composite of 3D Co 3 O 4 -HPND/CNTs were characterized by scanning electron microscopy, transmission electron microscopy, micropore and chemisorption analyzer, and X-ray diffraction. The electrochemical characterizations indicated that 3D Co 3 O 4 -HPND/CNTs present considerably catalytic activity toward glucose oxidation and could be promising for constructing high-performance electrochemical non-enzymatic glucose sensors and glucose/O 2 biofuel cell. When used for non-enzymatic glucose detection, the 3D Co 3 O 4 -HPND/CNTs modified glassy carbon electrode (3D Co 3 O 4 -HPND/CNTs/GCE) exhibited excellent analytical performance with high sensitivity (22.21 mA mM -1  cm -2 ), low detection limit of 0.35 μM (S/N = 3), fast response (less than 5 s) and good stability. On the other hand, when the 3D Co 3 O 4 -HPND/CNTs/GCE worked as an anode of a biofuel cell, a maximum power density of 210 μW cm -2 at 0.15 V could be obtained, and the open circuit potential was 0.68 V. The attractive 3D hierarchical porous structural features, the large surface area, and the excellent conductivity based on the continuous and effective electron transport network in 3D Co 3 O 4 -HPND/CNTs endow 3D Co 3 O 4 -HPND/CNTs with the enhanced electrochemical performance and promising applications in electrochemical sensing, biofuel cell, and other energy storage and conversion devices such as supercapacitor. Graphical abstract High-performance non-enzymatic catalysts for enzymeless glucose sensing and biofuel cell based on 3D hierarchical hollow porous Co 3 O 4 nanododecahedras anchored on carbon nanotubes were successfully prepared via direct carbonizing

  1. Effects of roasting temperature and duration on fatty acid composition, phenolic composition, Maillard reaction degree and antioxidant attribute of almond (Prunus dulcis) kernel.

    Science.gov (United States)

    Lin, Jau-Tien; Liu, Shih-Chun; Hu, Chao-Chin; Shyu, Yung-Shin; Hsu, Chia-Ying; Yang, Deng-Jye

    2016-01-01

    Roasting treatment increased levels of unsaturated fatty acids (linoleic, oleic and elaidic acids) as well as saturated fatty acids (palmitic and stearic acids) in almond (Prunus dulcis) kernel oils with temperature (150 or 180 °C) and duration (5, 10 or 20 min). Nonetheless, higher temperature (200 °C) and longer duration (10 or 20 min) roasting might result in breakdown of fatty acids especially for unsaturated fatty acids. Phenolic components (total phenols, flavonoids, condensed tannins and phenolic acids) of almond kernels substantially lost in the initial phase; afterward these components gradually increased with roasting temperature and duration. Similar results also observed for their antioxidant activities (scavenging DPPH and ABTS(+) radicals and ferric reducing power). The changes of phenolic acid and flavonoid compositions were also determined by HPLC. Maillard reaction products (estimated with non-enzymatic browning index) also increased with roasting temperature and duration; they might also contribute to enhancing the antioxidant attributes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Tune Your Brown Clustering, Please

    DEFF Research Database (Denmark)

    Derczynski, Leon; Chester, Sean; Bøgh, Kenneth Sejdenfaden

    2015-01-01

    Brown clustering, an unsupervised hierarchical clustering technique based on ngram mutual information, has proven useful in many NLP applications. However, most uses of Brown clustering employ the same default configuration; the appropriateness of this configuration has gone predominantly...

  3. Fucoidans from brown seaweeds

    DEFF Research Database (Denmark)

    Ale, Marcel Tutor; Meyer, Anne S.

    2013-01-01

    Fucoidan or fucoidans cover a family of sulfated fucose-rich polysaccharides, built of a backbone of L-fucose units, and characteristically found in brown seaweeds. Fucoidans have potential therapeutic properties, including anti-inflammatory and anti-coagulant activities, as well as anti-prolifer...

  4. Molecular Selectivity of Brown Carbon Chromophores

    Energy Technology Data Exchange (ETDEWEB)

    Laskin, Julia; Laskin, Alexander; Nizkorodov, Sergey; Roach, Patrick J.; Eckert, Peter A.; Gilles, Mary K.; Wang, Bingbing; Lee, Hyun Ji; Hu, Qichi

    2014-10-21

    Complementary methods of high-resolution mass spectrometry and micro-spectroscopy were utilized for molecular analysis of secondary organic aerosol (SOA) generated from ozonolysis of two structural monoterpene isomers: D-limonene (LSOA) and a-pinene (PSOA). Laboratory simulated aging of LSOA and PSOA, through conversion of carbonyls into imines mediated by NH3 vapors in humid air, resulted in selective browning of the LSOA sample, while the PSOA sample remained white. Comparative analysis of the reaction products in the aged LSOA and PSOA samples provided insights into chemistry relevant to formation of brown carbon chromophores. A significant fraction of carbonyl-imine conversion products with identical molecular formulas were detected in both samples. This reflects the high level of similarity in the molecular composition of these two closely related SOA materials. Several highly conjugated products were detected exclusively in the brown LSOA sample and were identified as potential chromophores responsible for the observed color change. The majority of the unique products in the aged LSOA sample with the highest number of double bonds contain two nitrogen atoms. We conclude that chromophores characteristic of the carbonyl- imine chemistry in LSOA are highly conjugated oligomers of secondary imines (Schiff bases) present at relatively low concentrations. Formation of this type of conjugated compounds in PSOA is hindered by the structural rigidity of the a-pinene oxidation products. Our results suggest that the overall light-absorbing properties of SOA may be determined by trace amounts of strong brown carbon chromophores.

  5. Low accumulation of chlorogenic acids represses reddening during flesh browning in Japanese peach "Okayama PEH7".

    Science.gov (United States)

    Yokotani, Naoki; Uraji, Misugi; Hara, Miyuki; Hihara, Seisuke; Hatanaka, Tadashi; Oda, Kenji

    2017-01-01

    In peaches, fruit flesh browns unattractively after peeling or cutting. A recently developed cultivar, Okayama PEH7, was distinct from other Japanese cultivars, including Okayama PEH8, with respect to its reduced browning potential. Homogenate prepared from Okayama PEH7 flesh had significantly less reddening during the browning reaction. Okayama PEH7 had less soluble phenolic compounds and higher polyphenol oxidase activity than Okayama PEH8. Reduced browning was observed even when phenols prepared from Okayama PEH7 were incubated with crude extract from Okayama PEH8, suggesting that phenols lower the browning potential of Okayama PEH7. In Okayama PEH7, contents of chlorogenic acid and its isomers were about one-tenth compared to Okayama PEH8. Exogenous addition of chlorogenic acid to Okayama PEH7 homogenate increased the browning potential and visibly enhanced reddening. These results indicate that the reduced browning of Okayama PEH7 flesh is due to a defect in chlorogenic acid accumulation.

  6. Differences in crystalline cellulose modification due to degradation by brown and white rot fungi.

    Science.gov (United States)

    Hastrup, Anne Christine Steenkjær; Howell, Caitlin; Larsen, Flemming Hofmann; Sathitsuksanoh, Noppadon; Goodell, Barry; Jellison, Jody

    2012-10-01

    Wood-decaying basidiomycetes are some of the most effective bioconverters of lignocellulose in nature, however the way they alter wood crystalline cellulose on a molecular level is still not well understood. To address this, we examined and compared changes in wood undergoing decay by two species of brown rot fungi, Gloeophyllum trabeum and Meruliporia incrassata, and two species of white rot fungi, Irpex lacteus and Pycnoporus sanguineus, using X-ray diffraction (XRD) and (13)C solid-state nuclear magnetic resonance (NMR) spectroscopy. The overall percent crystallinity in wood undergoing decay by M. incrassata, G. trabeum, and I. lacteus appeared to decrease according to the stage of decay, while in wood decayed by P. sanguineus the crystallinity was found to increase during some stages of degradation. This result is suggested to be potentially due to the different decay strategies employed by these fungi. The average spacing between the 200 cellulose crystal planes was significantly decreased in wood degraded by brown rot, whereas changes observed in wood degraded by the two white rot fungi examined varied according to the selectivity for lignin. The conclusions were supported by a quantitative analysis of the structural components in the wood before and during decay confirming the distinct differences observed for brown and white rot fungi. The results from this study were consistent with differences in degradation methods previously reported among fungal species, specifically more non-enzymatic degradation in brown rot versus more enzymatic degradation in white rot. Copyright © 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  7. Inhibition of tyrosinase-mediated enzymatic browning by sulfite and natural alternatives

    NARCIS (Netherlands)

    Kuijpers, T.F.M.; Vincken, J.P.

    2013-01-01

    Although sulfite is widely used to counteract enzymatic browning, its mechanism has remained largely unknown. We describe a double inhibitory mechanism of sulfite on enzymatic browning, affecting both the enzymatic oxidation of phenols into o‑quinones, as well as the non‑enzymatic reactions of these

  8. Radiation induced Maillard reactions (the kinetic of colour formation during heating)

    International Nuclear Information System (INIS)

    Tegota, A.; Bachman, S.

    1998-01-01

    The results are presented of the investigation of the effect of ionizing radiation from 60 Co on the acceleration of the Maillard reactions in a model system containing an aqueous solution of fructose (F) at 0.03 mol/dm 3 and alanine (Ala) at 0.01 mol/dm 3 . Solutions of F/Ala irradiated with 5 to 30 kGy at a dose rate 1.4 Gy/s were then heated for a few hours at different temperatures: 400, 600, 800, and 1000 deg C. The colour intensity of the solutions was measured via their absorbance at 450 nm. The reaction constant estimates increased with increasing radiation dose and temperature. The activation energy of colour development determined over the range of 600 deg C to 1000 deg C decreased with dose from 70.6 kJ/mol for 5 kGy to 60.7 kJ/mol for 30 kGy. The results confirmed the formation of carbonyl products from fructose radiolysis and their participation in the acceleration of the non-enzymatic browning reactions. The aldehyde products formed from the amino acids as a result of the Strecker degradation are responsible for the formation of odour typical of the Maillard reaction during heating. The changes in the F and Ala concentrations during irradiation of the solutions were proportional to the radiation dose. The radiation yield of fructose and alanine decomposition was G = 2.6 and 0.22, respectively. In the irradiated solutions of F/Ala, serine has been found, which has not been mentioned so far as a product of alanine radiolysis. The study demonstrates the influence of radiation and acceleration of the Maillard reaction during subsequent heating at 400 deg C up to 1000 deg C of systems containing reducing sugars and amino acids. It should be taken under consideration in the studies on introducing radiation technology of food products preservation connected with further thermal treatment

  9. Cascaded strand displacement for non-enzymatic target recycling amplification and label-free electronic detection of microRNA from tumor cells

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Kai; Dou, Baoting; Yang, Jianmei; Yuan, Ruo; Xiang, Yun, E-mail: yunatswu@swu.edu.cn

    2016-04-15

    The monitoring of microRNA (miRNA) expression levels is of great importance in cancer diagnosis. In the present work, based on two cascaded toehold-mediated strand displacement reactions (TSDRs), we have developed a label- and enzyme-free target recycling signal amplification approach for sensitive electronic detection of miRNA-21 from human breast cancer cells. The junction probes containing the locked G-quadruplex forming sequences are self-assembled on the senor surface. The presence of the target miRNA-21 initiates the first TSDR and results in the disassembly of the junction probes and the release of the active G-quadruplex forming sequences. Subsequently, the DNA fuel strand triggers the second TSDR and leads to cyclic reuse of the target miRNA-21. The cascaded TSDRs thus generate many active G-quadruplex forming sequences on the sensor surface, which associate with hemin to produce significantly amplified current response for sensitive detection of miRNA-21 at 1.15 fM. The sensor is also selective and can be employed to monitor miRNA-21 from human breast cancer cells. - Highlights: • Amplified and sensitive detection of microRNA from tumor cells is achieved. • Signal amplification is realized by two cascaded strand displacement reactions. • The developed sensor is selective and label-free without involving any enzymes.

  10. Cassava brown streak disease effects on leaf metabolites and ...

    African Journals Online (AJOL)

    Cassava Brown Streak Disease (CBSD) is a threat to productivity and product quality in East Africa. The objective of this study was to understand the effect of CBSD on the primary photosynthetic apparatus of cassava (Manihot esculenta Crantz). Three cassava varieties with varying levels of reaction to infection by CBSD ...

  11. cassava brown streak disease effects on leaf metabolites

    African Journals Online (AJOL)

    USER

    Cassava Brown Streak Disease (CBSD) is a threat to productivity and product quality in East Africa. The objective of this study was to understand the effect of CBSD on the primary photosynthetic apparatus of cassava (Manihot esculenta Crantz). Three cassava varieties with varying levels of reaction to infection by CBSD.

  12. A Very Cool Pair of Brown Dwarfs

    Science.gov (United States)

    2011-03-01

    Observations with the European Southern Observatory's Very Large Telescope, along with two other telescopes, have shown that there is a new candidate for the coldest known star: a brown dwarf in a double system with about the same temperature as a freshly made cup of tea - hot in human terms, but extraordinarily cold for the surface of a star. This object is cool enough to begin crossing the blurred line dividing small cold stars from big hot planets. Brown dwarfs are essentially failed stars: they lack enough mass for gravity to trigger the nuclear reactions that make stars shine. The newly discovered brown dwarf, identified as CFBDSIR 1458+10B, is the dimmer member of a binary brown dwarf system located just 75 light-years from Earth [1]. The powerful X-shooter spectrograph on ESO's Very Large Telescope (VLT) was used to show that the composite object was very cool by brown dwarf standards. "We were very excited to see that this object had such a low temperature, but we couldn't have guessed that it would turn out to be a double system and have an even more interesting, even colder component," said Philippe Delorme of the Institut de planétologie et d'astrophysique de Grenoble (CNRS/Université Joseph Fourier), a co-author of the paper. CFBDSIR 1458+10 is the coolest brown dwarf binary found to date. The dimmer of the two dwarfs has now been found to have a temperature of about 100 degrees Celsius - the boiling point of water, and not much different from the temperature inside a sauna [2]. "At such temperatures we expect the brown dwarf to have properties that are different from previously known brown dwarfs and much closer to those of giant exoplanets - it could even have water clouds in its atmosphere," said Michael Liu of the University of Hawaii's Institute for Astronomy, who is lead author of the paper describing this new work. "In fact, once we start taking images of gas-giant planets around Sun-like stars in the near future, I expect that many of them

  13. 7 CFR 29.3505 - Brown colors.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Brown colors. 29.3505 Section 29.3505 Agriculture... Type 95) § 29.3505 Brown colors. A group of colors ranging from a light brown to a dark brown. These colors vary from medium to low saturation and from medium to very low brillance. As used in these...

  14. 7 CFR 29.2504 - Brown colors.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Brown colors. 29.2504 Section 29.2504 Agriculture...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2504 Brown colors. A group of colors ranging from a reddish brown to yellowish brown. These colors vary from low to medium saturation and from very...

  15. Phlorotannins from Brown Algae: inhibition of advanced glycation end products formation in high glucose induced Caenorhabditis elegans.

    Science.gov (United States)

    Shakambari, Ganeshan; Ashokkumar, Balasubramaniem; Varalakshmi, Perumal

    2015-06-01

    Advanced Glycation End products (AGE) generated in a non enzymatic protein glycation process are frequently associated with diabetes, aging and other chronic diseases. Here, we explored the protective effect of phlorotannins from brown algae Padina pavonica, Sargassum polycystum and Turbinaria ornata against AGEs formation. Phlorotannins were extracted from brown algae with methanol and its purity was analyzed by TLC and RP-HPLC-DAD. Twenty five grams of P. pavonica, S. polycystum, T. ornata yielded 27.6 ± 0.8 μg/ml, 37.7 μg/ml and 37.1 ± 0.74 μg/ml of phloroglucinol equivalent of phlorotannins, respectively. Antioxidant potentials were examined through DPPH assay and their IC50 values were P. pavonica (30.12 ± 0.99 μg), S. polycystum (40.9 ± 1.2 μg) and T. ornata (22.9 ± 1.3 μg), which was comparatively lesser than the control ascorbic acid (46 ± 0.2 μg). Further, anti-AGE activity was examined in vitro by BSA-glucose assay with the extracted phlorotannins of brown algae (P. pavonica, 15.16 ± 0.26 μg/ml; S. polycystum, 35.245 ± 2.3 μg/ml; T. ornata, 22.7 ± 0.3 μg/ml), which revealed the required concentration to inhibit 50% of albumin glycation (IC50) were lower for extracts than controls (phloroglucinol, 222.33 ± 4.9 μg/ml; thiamine, 263 μg/ml). Furthermore, brown algal extracts containing phlorotannins (100 μl) exhibited protective effects against AGE formation in vivo in C. elegans with induced hyperglycemia.

  16. Kinetic modelling of the Maillard reaction between proteins and sugars

    NARCIS (Netherlands)

    Brands, C.M.J.

    2002-01-01

    Keywords: Maillard reaction, sugar isomerisation, kinetics, multiresponse modelling, brown colour formation, lysine damage, mutagenicity, casein, monosaccharides, disaccharides, aldoses, ketoses

    The aim of this thesis was to determine the kinetics of the Maillard reaction between

  17. Microbial reactions in coal and coal relevant structures. Part project: fungal and enzymatic depolarisation of brown coal for the production of low-molecular compounds. Interim report; Mikrobielle Umsetzung an Kohle und kohlenrelevanten Strukturen. Teilvorhaben: Pilzliche und enzymatische Depolymerisation von Braunkohle zur Gewinnung niedermolekularer Verbindungen. Zwischenbericht (Berichtszeitraum 01.01.1998 - 31.12.1998)

    Energy Technology Data Exchange (ETDEWEB)

    Ziegenhagen, D.; Bublitz, F.; Sorge, S.; Ullrich, R.; Hofrichter, M.; Fritsche, W.

    1999-04-29

    The present research project involved a study of the depolymerisation of brown coal constituents. The purpose of the depolymerisation experiments, which were carried out with fungi as well as their (acellular) enzymes, was to obtain products with a potential market value. Research focussed on one of the key enzymes of lignocellulose degradation, namely manganese (II) peroxidase (MnP). The effects of this enzyme on the depolymerisation of brown coal was studied in detail in acellular systems. The insights gained in this way then served as a basis for optimising the fungal and enzymatic depolymerisation processes for maximum yields of low-molecular products. The experiments carried out during the period under review were oriented to finding new types of lignolytically active organisms, isolating lignolytic enzymes and immobilising them on natural support materials, and further examining the action spectrum of MnP. Different model substrates were used in order to gain information on what bond types are MnP-cleavable and on possible reaction products. Substrates were either fixed to silica gel as support material or used without support material. The idea of using substrates fixed to support materials was motivated by the need to distinguish between intracellular and extracellular reactions involving the fungal mycelium. [Deutsch] Im Rahmen des Forschungsvorhabens wird die Depolymerisation von Braunkohle-Bestandteilen untersucht. Ziel der sowohl mit Pilzorganismen als auch mit deren Enzymen (zellfrei) durchgefuehrten Depolymerisationsversuche ist die Gewinnung von Produkten mit potentiellem Werkstoffcharakter. Im Mittelpunkt der Forschung steht eines der Schluesselenzyme des Ligninozellulose-Abbaus: Die Mangan(II)-Peroxidase (MnP). Die Wirkung dieses Enzyms bei der Depolymerisation von Braunkohle (Bk) in zellfreien Systemen wird weitergehend untersucht. Auf Grundlage der gewonnenen Erkenntnisse werden die pilzlichen und enzymatischen Depolymerisationsprozesse so

  18. A combined self-assembly and calcination method for preparation of nanoparticles-assembled cobalt oxide nanosheets using graphene oxide as template and their application for non-enzymatic glucose biosensing.

    Science.gov (United States)

    Zhang, Haiyan; Liu, Sen

    2017-01-01

    Cobalt oxide (Co 3 O 4 )-based materials have been extensively investigated as efficient electrocatalysts for non-enzymatic glucose biosensing. The proper tuning the structure of Co 3 O 4 -based materials could improve sensing performances for glucose detection. Herein, we have developed a combined self-assembly and calcination method to prepare nanoparticles-assembled Co 3 O 4 nanosheets, which exhibit good sensing performances for glucose biosensing. The Co 3 O 4 nanosheets were prepared by the following three steps: (i) the Co 2+ modified graphene oxide (GO) was prepared by the self-assembly of Co 2+ and GO in aqueous solution firstly, and then Co 2+ modified GO film was obtained by vacuum filtration method; (ii) after calcination of Co 2+ modified GO film in N 2 atmosphere, Co 3 O 4 nanoparticles modified reduced GO (RGO) was obtained; (iii) finally, nanoparticles-assembled Co 3 O 4 nanosheets were obtained by calcination of Co 3 O 4 modified RGO in air to remove RGO template. Most importantly, Co 3 O 4 nanosheets exhibit good electrocatalytic activity for oxidation of glucose, leading to high-performance glucose sensor. The detection limit and linear range of Co 3 O 4 nanosheets-based glucose sensor in the present work are 0.15μM, and 1-50μM, respectively. Furthermore, such sensor also shows excellent selectivity for glucose detection, compared to the commonly interfering species including dopamine, and uric acid. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Brown coal gasification made easy

    International Nuclear Information System (INIS)

    Hamilton, Chris

    2006-01-01

    Few Victorians will be aware that gas derived from coal was first used in 1849 to provide lighting in a baker's shop in Swanston Street, long before electric lighting came to the State. The first commercial 'gas works' came on stream in 1856 and Melbourne then had street lighting run on gas. By 1892 there were 50 such gas works across the State. Virtually all were fed with black coal imported from New South Wales. Brown coal was first discovered west of Melbourne in 1857, and the Latrobe Valley deposits were identified in the early 1870s. Unfortunately, such wet brown coal did not suit the gas works. Various attempts to commercialise Victorian brown coal met with mixed success as it struggled to compete with imported New South Wales black coal. In June 1924 Yallourn A transmitted the first electric power to Melbourne, and thus began the Latrobe Valley's long association with generating electric power from brown coal. Around 1950, the Metropolitan Gas Company applied for financial assistance to build a towns gas plant using imported German gasification technology which had been originally designed for a brown coal briquette feed. The State Government promptly acquired the company and formed the Gas and Fuel Corporation. The Morwell Gasification Plant was opened on 9 December 1956 and began supplying Melbourne with medium heating value towns gas

  20. Effect of heat treatment on polyphenol oxidase and peroxidase ...

    African Journals Online (AJOL)

    GREGO

    2006-12-18

    Dec 18, 2006 ... Polyphenol oxidase (EC 1.14.18.1) catalyses enzyma- tic browning through its action on mono and o-diphenols. (Mayer and Harel, 1979; Golbeck and Camarata, 1981;. Mayer and Harel, 1991). Browning of dates was found to be related to enzymatic and non - enzymatic reactions. *Corresponding author.

  1. Nonenzymatic browning of lactose and caseinate during dry heating at different relative humidities.

    Science.gov (United States)

    Pan, Geoffrey Ge; Melton, Laurence D

    2007-11-28

    Dry mixtures of lactose and caseinate were heated at 60 degrees C for up to 96 h at different relative humidities (RHs) ranging from 29 to 95%. The resulting nonenzymatic browning was studied by determining lactulosyl lysine formation in the caseinate (as measured by the conversion to furosine), amount of reacted lactose, loss of lysine, color formation, and fluorescent intensity. For each measurement, the maximum reaction occurred at intermediate RHs. While there is general agreement between the results obtained by different methods, discrepancies are understandable given the complex nature of nonenzymatic browning. It was shown that the degradation of the Amadori product, lactulosyl lysine, increased with RH. Moreover, the Maillard reaction, as opposed to caramelization of lactose, was the major pathway at all RHs. Visible browning occurred when the destruction of Amadori product became dominant, and interactions between sugar fragments and caseinate were not the rate-limiting steps in the nonenzymatic browning.

  2. Fungal accumulation of metals from building materials during brown rot wood decay.

    Science.gov (United States)

    Hastrup, Anne Christine Steenkjær; Jensen, Bo; Jellison, Jody

    2014-08-01

    This study analyzes the accumulation and translocation of metal ions in wood during the degradation performed by one strain of each of the three brown rot fungi; Serpula lacrymans, Meruliporia incrassata and Coniophora puteana. These fungi species are inhabitants of the built environment where the prevention and understanding of fungal decay is of high priority. This study focuses on the influence of various building materials in relation to fungal growth and metal uptake. Changes in the concentration of iron, manganese, calcium and copper ions in the decayed wood were analyzed by induced coupled plasma spectroscopy and related to wood weight loss and oxalic acid accumulation. Metal transport into the fungal inoculated wood was found to be dependent on the individual strain/species. The S. lacrymans strain caused a significant increase in total iron whereas the concentration of copper ions in the wood appeared decreased after 10 weeks of decay. Wood inoculated with the M. incrassata isolate showed the contrary tendency with high copper accumulation and low iron increase despite similar weight losses for the two strains. However, significantly lower oxalic acid accumulation was recorded in M. incrassata degraded wood. The addition of a building material resulted in increased weight loss in wood degraded by C. puteana in the soil-block test; however, this could not be directly linked specifically to the accumulation of any of the four metals recorded. The accumulation of oxalic acid seemed to influence the iron uptake. The study assessing the influence of the presence of soil and glass in the soil-block test revealed that soil contributed the majority of the metals for uptake by the fungi and contributed to increased weight loss. The varying uptake observed among the three brown rot fungi strains toward the four metals analyzed may be related to the specific non-enzymatic and enzymatic properties including bio-chelators employed by each of the species during wood

  3. Fulfilling the Promise of Brown.

    Science.gov (United States)

    Winston, Judith A.

    1995-01-01

    Summarizes the U.S. Department of Education's efforts to implement the mandate of "Brown v. Board of Education of Topeka, Kansas" and the Civil Rights Act of 1964, examining traditional tools used in enforcing civil rights laws and reviewing new strategies to promote high quality education, equal educational opportunity, and diversity.…

  4. Brown at 50: Keeping Promises

    Science.gov (United States)

    Wu, Frank H.

    2004-01-01

    The story of Brown is compelling. Blacks and Whites alike understood that the Jim Crow system of "separate but equal" was a convenient fiction. There was no actual effort to ensure that Whites and Blacks were provided the same services. Invariably, the White schools had higher funding, better buildings, newer supplies and so on. Indeed,…

  5. 7 CFR 29.2254 - Brown colors.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Brown colors. 29.2254 Section 29.2254 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... colors. A group of colors ranging from a reddish brown to yellowish brown. These colors vary from low to...

  6. 21 CFR 184.1120 - Brown algae.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Brown algae. 184.1120 Section 184.1120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1120 Brown algae. (a) Brown algae are seaweeds of the species Analipus...

  7. Two acidic, anticoagulant PLA2 isoenzymes purified from the venom of monocled cobra Naja kaouthia exhibit different potency to inhibit thrombin and factor Xa via phospholipids independent, non-enzymatic mechanism.

    Directory of Open Access Journals (Sweden)

    Ashis K Mukherjee

    Full Text Available The monocled cobra (Naja kaouthia is responsible for snakebite fatality in Indian subcontinent and in south-western China. Phospholipase A2 (PLA2; EC 3.1.1.4 is one of the toxic components of snake venom. The present study explores the mechanism and rationale(s for the differences in anticoagulant potency of two acidic PLA2 isoenzymes, Nk-PLA2α (13463.91 Da and Nk-PLA2β (13282.38 Da purified from the venom of N. kaouthia.By LC-MS/MS analysis, these PLA2s showed highest similarity (23.5% sequence coverage with PLA2 III isolated from monocled cobra venom. The catalytic activity of Nk-PLA2β exceeds that of Nk-PLA2α. Heparin differentially regulated the catalytic and anticoagulant activities of these Nk-PLA2 isoenzymes. The anticoagulant potency of Nk-PLA2α was comparable to commercial anticoagulants warfarin, and heparin/antithrombin-III albeit Nk-PLA2β demonstrated highest anticoagulant activity. The anticoagulant action of these PLA2s was partially contributed by a small but specific hydrolysis of plasma phospholipids. The strong anticoagulant effect of Nk-PLA2α and Nk-PLA2β was achieved via preferential, non-enzymatic inhibition of FXa (Ki = 43 nM and thrombin (Ki = 8.3 nM, respectively. Kinetics study suggests that the Nk-PLA2 isoenzymes inhibit their "pharmacological target(s" by uncompetitive mechanism without the requirement of phospholipids/Ca(2+. The anticoagulant potency of Nk-PLA2β which is higher than that of Nk-PLA2α is corroborated by its superior catalytic activity, its higher capacity for binding to phosphatidylcholine, and its greater strength of thrombin inhibition. These PLA2 isoenzymes thus have evolved to affect haemostasis by different mechanisms. The Nk-PLA2β partially inhibited the thrombin-induced aggregation of mammalian platelets suggesting its therapeutic application in the prevention of unwanted clot formation.In order to develop peptide-based superior anticoagulant therapeutics, future application of Nk-PLA2

  8. Metabolically active human brown adipose tissue derived stem cells.

    Science.gov (United States)

    Silva, Francisco J; Holt, Dolly J; Vargas, Vanessa; Yockman, James; Boudina, Sihem; Atkinson, Donald; Grainger, David W; Revelo, Monica P; Sherman, Warren; Bull, David A; Patel, Amit N

    2014-02-01

    Brown adipose tissue (BAT) plays a key role in the evolutionarily conserved mechanisms underlying energy homeostasis in mammals. It is characterized by fat vacuoles 5-10 µm in diameter and expression of uncoupling protein one, central to the regulation of thermogenesis. In the human newborn, BAT depots are typically grouped around the vasculature and solid organs. These depots maintain body temperature during cold exposure by warming the blood before its distribution to the periphery. They also ensure an optimal temperature for biochemical reactions within solid organs. BAT had been thought to involute throughout childhood and adolescence. Recent studies, however, have confirmed the presence of active BAT in adult humans with depots residing in cervical, supraclavicular, mediastinal, paravertebral, and suprarenal regions. While human pluripotent stem cells have been differentiated into functional brown adipocytes in vitro and brown adipocyte progenitor cells have been identified in murine skeletal muscle and white adipose tissue, multipotent metabolically active BAT-derived stem cells from a single depot have not been identified in adult humans to date. Here, we demonstrate a clonogenic population of metabolically active BAT stem cells residing in adult humans that can: (a) be expanded in vitro; (b) exhibit multilineage differentiation potential; and (c) functionally differentiate into metabolically active brown adipocytes. Our study defines a new target stem cell population that can be activated to restore energy homeostasis in vivo for the treatment of obesity and related metabolic disorders. © 2013 AlphaMed Press.

  9. Baking, ageing, diabetes: a short history of the Maillard reaction.

    Science.gov (United States)

    Hellwig, Michael; Henle, Thomas

    2014-09-22

    The reaction of reducing carbohydrates with amino compounds described in 1912 by Louis-Camille Maillard is responsible for the aroma, taste, and appearance of thermally processed food. The discovery that non-enzymatic conversions also occur in organisms led to intensive investigation of the pathophysiological significance of the Maillard reaction in diabetes and ageing processes. Dietary Maillard products are discussed as "glycotoxins" and thus as a nutritional risk, but also increasingly with regard to positive effects in the human body. In this Review we give an overview of the most important discoveries in Maillard research since it was first described and show that the complex reaction, even after over one hundred years, has lost none of its interdisciplinary actuality. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Low molecular weight anti-carboxymethyl lysine reactive bands in cashew extracts

    Science.gov (United States)

    The Maillard Reaction is the non-enzymatic browning of foods during thermal processing, and is a result of the reaction of reducing sugar carbonyl groups and primary amine groups of proteins. Maillard Reaction products are unstable, and Amadori rearrangements result in a network of chemical modifica...

  11. Brown carbon formation from ketoaldehydes of biogenic monoterpenes

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Tran B.; Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey

    2013-04-10

    Sources and chemical composition of the brown carbon are poorly understood, and even less is known about the mechanisms of its atmospheric transformations. This work presents molecular level investigation of the reactive compound ketolimononaldehyde (KLA, C9H14O3), a second generation ozonolysis product of limonene (C10H16), as a potent brown carbon precursor in secondary organic aerosol (SOA) through its reactions with reduced nitrogen compounds such as ammonium ion (NH4+), ammonia, and amino acids. The reactions of synthesized and purified KLA with NH4+ and glycine resulted in the formation of chromophores nearly identical in spectral properties and formation rates to those found in similarly-aged limonene/O3 SOA. Similar chemical reaction processes of limononaldehyde (LA, C10H16O2) and pinonaldehyde (PA, C10H16O2), the first-generation ozonolysis products in the oxidation of limonene and α-pinene, respectively, were also studied, but the resulting products did not exhibit light absorption properties of brown carbon, suggesting that the unique molecular structure of KLA produces visible-light-absorbing compounds. The KLA/NH4+ and KLA/GLY reactions produce water-soluble, hydrolysis-resilient chromophores with high mass absorption coefficients (MAC = 2000-4000 cm2 g-1) at λ ~ 500 nm, precisely at the maximum of the solar emission spectrum. Liquid chromatography was used to isolate the light-absorbing fraction, and UV-Vis, FTIR, NMR and high-resolution mass spectrometry (HR-MS) techniques were used to investigate the structures and chemical properties of the light-absorbing compounds. The KLA browning reaction generates a diverse mixture of light-absorbing compounds, with the majority of the observable products containing 1-4 units of KLA and 0-2 nitrogen atoms. Based on the HR-MS product distribution, conjugated aldol condensates, secondary imines (Schiff bases), and N-heterocycles like pyrroles may contribute in varying degree to the light-absorbing properties

  12. The role of various amino acids in enzymatic browning process in potato tubers, and identifying the browning products.

    Science.gov (United States)

    Ali, Hussein M; El-Gizawy, Ahmed M; El-Bassiouny, Rawia E I; Saleh, Mahmoud A

    2016-02-01

    The effects of five structurally variant amino acids, glycine, valine, methionine, phenylalanine and cysteine were examined as inhibitors and/or stimulators of fresh-cut potato browning. The first four amino acids showed conflict effects; high concentrations (⩾ 100mM for glycine and ⩾ 1.0M for the other three amino acids) induced potato browning while lower concentrations reduced the browning process. Alternatively, increasing cysteine concentration consistently reduced the browning process due to reaction with quinone to give colorless adduct. In PPO assay, high concentrations (⩾ 1.11 mM) of the four amino acids developed more color than that of control samples. Visible spectra indicated a continuous condensation of quinone and glycine to give colored adducts absorbed at 610-630 nm which were separated and identified by LC-ESI-MS as catechol-diglycine adduct that undergoes polymerization with other glycine molecules to form peptide side chains. In lower concentrations, the less concentration the less developed color was observed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Brown dwarfs as dark galactic halos

    International Nuclear Information System (INIS)

    Adams, F.C.; Walker, T.P.

    1990-01-01

    The possibility that the dark matter in galactic halos can consist of brown dwarf stars is considered. The radiative signature for such halos consisting solely of brown dwarfs is calculated, and the allowed range of brown dwarf masses, the initial mass function (IMF), the stellar properties, and the density distribution of the galactic halo are discussed. The prediction emission from the halo is compared with existing observations. It is found that, for any IMF of brown dwarfs below the deuterium burning limit, brown dwarf halos are consistent with observations. Brown dwarf halos cannot, however, explain the recently observed near-IR background. It is shown that future satellite missions will either detect brown dwarf halos or place tight constraints on the allowed range of the IMF. 30 refs

  14. Brown spider dermonecrotic toxin directly induces nephrotoxicity

    International Nuclear Information System (INIS)

    Chaim, Olga Meiri; Sade, Youssef Bacila; Bertoni da Silveira, Rafael; Toma, Leny; Kalapothakis, Evanguedes; Chavez-Olortegui, Carlos; Mangili, Oldemir Carlos; Gremski, Waldemiro; Dietrich, Carl Peter von; Nader, Helena B.; Sanches Veiga, Silvio

    2006-01-01

    Brown spider (Loxosceles genus) venom can induce dermonecrotic lesions at the bite site and systemic manifestations including fever, vomiting, convulsions, disseminated intravascular coagulation, hemolytic anemia and acute renal failure. The venom is composed of a mixture of proteins with several molecules biochemically and biologically well characterized. The mechanism by which the venom induces renal damage is unknown. By using mice exposed to Loxosceles intermedia recombinant dermonecrotic toxin (LiRecDT), we showed direct induction of renal injuries. Microscopic analysis of renal biopsies from dermonecrotic toxin-treated mice showed histological alterations including glomerular edema and tubular necrosis. Hyalinization of tubules with deposition of proteinaceous material in the tubule lumen, tubule epithelial cell vacuoles, tubular edema and epithelial cell lysis was also observed. Leukocytic infiltration was neither observed in the glomerulus nor the tubules. Renal vessels showed no sign of inflammatory response. Additionally, biochemical analyses showed such toxin-induced changes in renal function as urine alkalinization, hematuria and azotemia with elevation of blood urea nitrogen levels. Immunofluorescence with dermonecrotic toxin antibodies and confocal microscopy analysis showed deposition and direct binding of this toxin to renal intrinsic structures. By immunoblotting with a hyperimmune dermonecrotic toxin antiserum on renal lysates from toxin-treated mice, we detected a positive signal at the region of 33-35 kDa, which strengthens the idea that renal failure is directly induced by dermonecrotic toxin. Immunofluorescence reaction with dermonecrotic toxin antibodies revealed deposition and binding of this toxin directly in MDCK epithelial cells in culture. Similarly, dermonecrotic toxin treatment caused morphological alterations of MDCK cells including cytoplasmic vacuoles, blebs, evoked impaired spreading and detached cells from each other and from

  15. Brown adipose tissue in cetacean blubber.

    Directory of Open Access Journals (Sweden)

    Osamu Hashimoto

    Full Text Available Brown adipose tissue (BAT plays an important role in thermoregulation in species living in cold environments, given heat can be generated from its chemical energy reserves. Here we investigate the existence of BAT in blubber in four species of delphinoid cetacean, the Pacific white-sided and bottlenose dolphins, Lagenorhynchus obliquidens and Tursiops truncates, and Dall's and harbour porpoises, Phocoenoides dalli and Phocoena phocoena. Histology revealed adipocytes with small unilocular fat droplets and a large eosinophilic cytoplasm intermingled with connective tissue in the innermost layers of blubber. Chemistry revealed a brown adipocyte-specific mitochondrial protein, uncoupling protein 1 (UCP1, within these same adipocytes, but not those distributed elsewhere throughout the blubber. Western blot analysis of extracts from the inner blubber layer confirmed that the immunohistochemical positive reaction was specific to UCP1 and that this adipose tissue was BAT. To better understand the distribution of BAT throughout the entire cetacean body, cadavers were subjected to computed tomography (CT scanning. Resulting imagery, coupled with histological corroboration of fine tissue structure, revealed adipocytes intermingled with connective tissue in the lowest layer of blubber were distributed within a thin, highly dense layer that extended the length of the body, with the exception of the rostrum, fin and fluke regions. As such, we describe BAT effectively enveloping the cetacean body. Our results suggest that delphinoid blubber could serve a role additional to those frequently attributed to it: simple insulation blanket, energy storage, hydrodynamic streamlining or contributor to positive buoyancy. We believe delphinoid BAT might also function like an electric blanket, enabling animals to frequent waters cooler than blubber as an insulator alone might otherwise allow an animal to withstand, or allow animals to maintain body temperature in cool

  16. Brown adipose tissue in cetacean blubber.

    Science.gov (United States)

    Hashimoto, Osamu; Ohtsuki, Hirofumi; Kakizaki, Takehiko; Amou, Kento; Sato, Ryo; Doi, Satoru; Kobayashi, Sara; Matsuda, Ayaka; Sugiyama, Makoto; Funaba, Masayuki; Matsuishi, Takashi; Terasawa, Fumio; Shindo, Junji; Endo, Hideki

    2015-01-01

    Brown adipose tissue (BAT) plays an important role in thermoregulation in species living in cold environments, given heat can be generated from its chemical energy reserves. Here we investigate the existence of BAT in blubber in four species of delphinoid cetacean, the Pacific white-sided and bottlenose dolphins, Lagenorhynchus obliquidens and Tursiops truncates, and Dall's and harbour porpoises, Phocoenoides dalli and Phocoena phocoena. Histology revealed adipocytes with small unilocular fat droplets and a large eosinophilic cytoplasm intermingled with connective tissue in the innermost layers of blubber. Chemistry revealed a brown adipocyte-specific mitochondrial protein, uncoupling protein 1 (UCP1), within these same adipocytes, but not those distributed elsewhere throughout the blubber. Western blot analysis of extracts from the inner blubber layer confirmed that the immunohistochemical positive reaction was specific to UCP1 and that this adipose tissue was BAT. To better understand the distribution of BAT throughout the entire cetacean body, cadavers were subjected to computed tomography (CT) scanning. Resulting imagery, coupled with histological corroboration of fine tissue structure, revealed adipocytes intermingled with connective tissue in the lowest layer of blubber were distributed within a thin, highly dense layer that extended the length of the body, with the exception of the rostrum, fin and fluke regions. As such, we describe BAT effectively enveloping the cetacean body. Our results suggest that delphinoid blubber could serve a role additional to those frequently attributed to it: simple insulation blanket, energy storage, hydrodynamic streamlining or contributor to positive buoyancy. We believe delphinoid BAT might also function like an electric blanket, enabling animals to frequent waters cooler than blubber as an insulator alone might otherwise allow an animal to withstand, or allow animals to maintain body temperature in cool waters during

  17. The Engrailed-1 Gene Stimulates Brown Adipogenesis

    Directory of Open Access Journals (Sweden)

    Chuanhai Zhang

    2016-01-01

    Full Text Available As a thermogenic organ, brown adipose tissue (BAT has received a great attention in treating obesity and related diseases. It has been reported that brown adipocyte was derived from engrailed-1 (EN1 positive central dermomyotome. However, functions of EN1 in brown adipogenesis are largely unknown. Here we demonstrated that EN1 overexpression increased while EN1 knockdown decreased lipid accumulation and the expressions of key adipogenic genes including PPARγ2 and C/EBPα and mitochondrial OXPHOS as well as BAT specific marker UCP1. Taken together, our findings clearly indicate that EN1 is a positive regulator of brown adipogenesis.

  18. Enzymatic Browning: a practical class

    Directory of Open Access Journals (Sweden)

    Maria Teresa Pedrosa Silva Clerici

    2014-10-01

    Full Text Available This paper presents a practical class about the enzymes polyphenol oxidases, which have been shown to be responsible for the enzymatic browning of fruits and vegetables. Vegetables samples were submitted to enzymatic inactivation process with chemical reagents, as well as by bleaching methods of applying heat by conventional oven and microwave oven. Process efficiency was assessed qualitatively by both observing the guaiacol peroxidase activity and after the storage period under refrigeration or freezing. The practical results obtained in this class allow exploring multidisciplinary knowledge in food science, with practical applications in everyday life.

  19. Brown Fat and Browning for the Treatment of Obesity and Related Metabolic Disorders

    Directory of Open Access Journals (Sweden)

    So Hun Kim

    2016-01-01

    Full Text Available Brown fat is a specialized fat depot that can increase energy expenditure and produce heat. After the recent discovery of the presence of active brown fat in human adults and novel transcription factors controlling brown adipocyte differentiation, the field of the study of brown fat has gained great interest and is rapidly growing. Brown fat expansion and/or activation results in increased energy expenditure and a negative energy balance in mice and limits weight gain. Brown fat is also able to utilize blood glucose and lipid and results in improved glucose metabolism and blood lipid independent of weight loss. Prolonged cold exposure and beta adrenergic agonists can induce browning of white adipose tissue. The inducible brown adipocyte, beige adipocyte evolving by thermogenic activation of white adipose tissue have different origin and molecular signature from classical brown adipocytes but share the characteristics of high mitochondria content, UCP1 expression and thermogenic capacity when activated. Increasing browning may also be an efficient way to increase whole brown fat activity. Recent human studies have shown possibilities that findings in mice can be reproduced in human, making brown fat a good candidate organ to treat obesity and its related disorders.

  20. Jahan et al., Afr J Tradit Complement Altern Med. (2015) 12(4):134 ...

    African Journals Online (AJOL)

    Proff.Adewunmi

    important chemical change is the condensation of sugars and free amino acids to produce brown pigments as a result of non-enzymatic Maillard reactions, which create Maillard reaction products that are believed to contribute to the antioxidant potential of honey (Manzocco, 2000). Dewanto et al. (2002) established that ...

  1. Brown dwarf disks with ALMA

    Energy Technology Data Exchange (ETDEWEB)

    Ricci, L.; Isella, A. [Department of Astronomy, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Testi, L.; De Gregorio-Monsalvo, I. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching (Germany); Natta, A. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy); Scholz, A., E-mail: lricci@astro.caltech.edu [School of Cosmic Physics, Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland)

    2014-08-10

    We present Atacama Large Millimeter/submillimeter Array continuum and spectral line data at 0.89 mm and 3.2 mm for three disks surrounding young brown dwarfs and very low mass stars in the Taurus star forming region. Dust thermal emission is detected and spatially resolved for all the three disks, while CO(J = 3-2) emission is seen in two disks. We analyze the continuum visibilities and constrain the disks' physical structure in dust. The results of our analysis show that the disks are relatively large; the smallest one has an outer radius of about 70 AU. The inferred disk radii, radial profiles of the dust surface density, and disk to central object mass ratios lie within the ranges found for disks around more massive young stars. We derive from our observations the wavelength dependence of the millimeter dust opacity. In all the three disks, data are consistent with the presence of grains with at least millimeter sizes, as also found for disks around young stars, and confirm that the early stages of the solid growth toward planetesimals occur also around very low-mass objects. We discuss the implications of our findings on models of solids evolution in protoplanetary disks, the main mechanisms proposed for the formation of brown dwarfs and very low-mass stars, as well as the potential of finding rocky and giant planets around very low-mass objects.

  2. Rapid pyrolysis of Serbian soft brown coals

    Directory of Open Access Journals (Sweden)

    Jankes Goran

    2009-01-01

    Full Text Available Soft brown coals of the open coal fields of Kolubara and Kostolac are the main domestic energy sources of Serbia. This paper presents the results of investigations on rapid devolatilization of these two coals which have covered kinetics of devolatilization (based on total volatile yield, forms of sulphur and petrographic analysis of coal and char. Experiments of devolatilization were performed in inert gas (N2 at atmospheric pressure and in batch-type hot-wire screen reactor. The mass-loss values of both coals at selected final reaction temperatures (300-900°C and retention times (3-28 s were obtained. Anthony and Howard's kinetic model was applied over two temperature ranges (300-500 and 700-900°C. The types of sulphur as monosulphide, sulphate, pyritic, and organic sulphur were determined for chars and original coals. Strong transformation of pyrite was evident even at low temperatures (300°C. Devolatilization of all types of sulphur has started over 600 and at 900°C the content of sulphur in char remained only 66% of total sulphur in original coal. Microscopic investigations were carried out on samples prepared for reflected light measurements. The petrographic analysis included: the ratio of unchanged and changed coal, maceral types, the share of cenosferes, isotropic mixed carbonized grains, mixed grains, small fragments, clay, and pyrite. The change of the structure of devolatilized coal was also observed.

  3. Rapid Molecular detection of citrus brown spot disease using ACT gene in Alternaria alternata

    Directory of Open Access Journals (Sweden)

    Hamid Moghimi

    2017-06-01

    Full Text Available Introduction:Using rapid detection methods is important for detection of plant pathogens and also prevention through spreading pests in agriculture. Citrus brown spot disease caused by pathogenic isolates of Alternaria alternata is a common disease in Iran. Materials and methods: In this study, for the first time a PCR based molecular method was used for rapid diagnosis of brown spot disease. Nine isolates of A. Alternata were isolated in PDA medium from different citrus gardens. The plant pathogenic activity was examined in tangerine leaves for isolates. Results showed that these isolates are the agents of brown spot disease. PCR amplification of specific ACT-toxin gene was performed for DNA extracted from A. alternata isolates, with 11 different fungal isolates as negative controls and 5 DNA samples extracted from soil. Results: Results showed that A. alternata, the causal agent of brown spot disease, can be carefully distinguished from other pathogenic agents by performing PCR amplification with specific primers for ACT toxin gene. Also, the results from Nested-PCR method confirmed the primary reaction and the specificity of A. alternata for brown spot disease. PCR results to control samples of the other standard fungal isolates, showed no amplification band. In addition, PCR with the DNA extracted from contaminated soils confirmed the presence of ACT toxin gene. Discussion and conclusion: Molecular procedure presented here can be used in rapid identification and prevention of brown spot infection in citrus gardens all over the country.

  4. Remembering "Brown": Silence, Loss, Rage, and Hope

    Science.gov (United States)

    Banks, James A.

    2004-01-01

    The author was in the seventh grade at the Newsome Training School in Aubrey, Arkansas when the Supreme Court handed down "Brown v. Board of Education" on May 17, 1954. His most powerful memory of the "Brown" decision is that he has no memory of it being rendered or mentioned by his parents, teachers, or preachers. In his rural…

  5. Isolation of glycoproteins from brown algae.

    OpenAIRE

    Surendraraj, Alagarsamy; Farvin Koduvayur Habeebullah , Sabeena; Jacobsen, Charlotte

    2015-01-01

    The present invention relates to a novel process for the isolation of unique anti-oxidative glycoproteins from the pH precipitated fractions of enzymatic extracts of brown algae. Two brown seaweeds viz, Fucus serratus and Fucus vesiculosus were hydrolysed by using 3 enzymes viz, Alcalase, Viscozyme and Termamyl and the glycoproteins were isolated from these enzyme extracts.

  6. Cytoskeleton and Morphogenesis in Brown Algae

    OpenAIRE

    KATSAROS, CHRISTOS; KARYOPHYLLIS, DEMOSTHENES; GALATIS, BASIL

    2006-01-01

    • Background Morphogenesis on a cellular level includes processes in which cytoskeleton and cell wall expansion are strongly involved. In brown algal zygotes, microtubules (MTs) and actin filaments (AFs) participate in polarity axis fixation, cell division and tip growth. Brown algal vegetative cells lack a cortical MT cytoskeleton, and are characterized by centriole-bearing centrosomes, which function as microtubule organizing centres.

  7. Microlensing Binaries with Candidate Brown Dwarf Companions

    DEFF Research Database (Denmark)

    Shin, I.-G; Han, C.; Gould, A.

    2012-01-01

    Brown dwarfs are important objects because they may provide a missing link between stars and planets, two populations that have dramatically different formation histories. In this paper, we present the candidate binaries with brown dwarf companions that are found by analyzing binary microlensing...... with well-covered light curves increases with new-generation searches....

  8. Brown vs. Board of Education Booklet

    OpenAIRE

    IDEA, UCLA

    2004-01-01

    This booklet was designed for K-12 classrooms and community groups examining the legacy of Brown v Board for California. The booklet chronicles the national battle for equal schooling up to and since the Brown decision. It also highlights the history of school segregation in California and the ongoing struggle for equal schooling.

  9. "Brown" and Black-White Achievement

    Science.gov (United States)

    Armor, David J.

    2006-01-01

    "Brown v. Board of Education" only presumed to eliminate the "de jure" apartheid that existed in 1954. It was never intended to resolve the "de facto" gap in minority achievement that still faces education policymakers today. Sociologist David J. Armor goes beyond "Brown" to identify a set of definite risk…

  10. Novel nuances of human brown fat

    DEFF Research Database (Denmark)

    Scheele, Camilla; Larsen, Therese Juhlin; Nielsen, Søren

    2014-01-01

    the types of thermogenic adipocytes in humans. We recently published a contradictory mRNA expression signature of human supraclavicular fat defined by an upregulation of the brite marker TBX1 along with the classical brown markers ZIC1 and LHX8, as well as genes indicating brown fat activity including UCP1...

  11. Thermochemical modelling of brown dwarf discs

    NARCIS (Netherlands)

    Greenwood, A. J.; Kamp, I.; Waters, L. B. F. M.; Woitke, P.; Thi, W.-F.; Rab, Ch.; Aresu, G.; Spaans, M.

    The physical properties of brown dwarf discs, in terms of their shapes and sizes, are still largely unexplored by observations. ALMA has by far the best capabilities to observe these discs in sub-mm CO lines and dust continuum, while also spatially resolving some discs. To what extent brown dwarf

  12. Effects of glucocorticoids on human brown adipocytes.

    Science.gov (United States)

    Barclay, Johanna L; Agada, Hadiya; Jang, Christina; Ward, Micheal; Wetzig, Neil; Ho, Ken K Y

    2015-02-01

    Clinical cases of glucocorticoid (GC) excess are characterized by increased fat mass and obesity through the accumulation of white adipocytes. The effects of GCs on growth and function of brown adipose tissue are unknown and may contribute to the negative energy balance observed clinically. This study aims to evaluate the effect of GCs on proliferation, differentiation, and metabolic function of brown adipocytes. Human brown adipocytes sourced from supraclavicular fat biopsies were grown in culture and differentiated to mature adipocytes. Human white adipocytes sourced from subcutaneous abdominal fat biopsies were cultured as controls. Effects of dexamethasone on growth, differentiation (UCP1, CIDEA, and PPARGC1A expression), and function (oxygen consumption rate (OCR)) of brown adipocytes were quantified. Dexamethasone (1 μM) significantly stimulated the proliferation of brown preadipocytes and reduced that of white preadipocytes. During differentiation, dexamethasone (at 0.1, 1, and 10 μM) stimulated the expression of UCP1, CIDEA, and PPARGC1A in a concentration-dependent manner and enhanced by fourfold to sixfold the OCR of brown adipocytes. Isoprenaline (100 nM) significantly increased (Peffects were significantly reduced (Peffects on development and function of brown adipocytes. These findings provide strong evidence for an effect of GCs on the biology of human brown adipose tissue (BAT) and for the involvement of the BAT system in the metabolic manifestation of Cushing's syndrome. © 2015 Society for Endocrinology.

  13. Isolation of glycoproteins from brown algae

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a novel process for the isolation of unique anti-oxidative glycoproteins from the pH precipitated fractions of enzymatic extracts of brown algae. Two brown seaweeds viz, Fucus serratus and Fucus vesiculosus were hydrolysed by using 3 enzymes viz, Alcalase, Viscozyme...

  14. Control of lethal browning by using ascorbic acid on shoot tip ...

    African Journals Online (AJOL)

    SAM

    2014-04-16

    Apr 16, 2014 ... vanillin coumurin, P-coumaric acid and phenol (Khalil et al., 2007). Browning reactions and astringency of the fruit caused by phenolic compounds are .... treatment (Table 2) and (Figure 1). It is well established that injured tissues normally stimulate the production of phenols (Dodds and Roberts, 1995).

  15. A fast and inexpensive DNA extraction/purification protocol for brown macroalgae

    NARCIS (Netherlands)

    Hoarau, Galice; Coyer, James A.; Stam, Wytze T.; Olsen, Jeanine L.

    Here we describe a rapid method for extracting DNA from dried brown algae material using a microtitre plate system in conjunction with a milling instrument. The method allows the preparation of nuclear and organelle DNA of quality suitable for polymerase chain reaction amplification. It combines

  16. Food Processing: The Influence of the Maillard Reaction on Immunogenicity and Allergenicity of Food Proteins

    Directory of Open Access Journals (Sweden)

    Malgorzata Teodorowicz

    2017-08-01

    Full Text Available The majority of foods that are consumed in our developed society have been processed. Processing promotes a non-enzymatic reaction between proteins and sugars, the Maillard reaction (MR. Maillard reaction products (MRPs contribute to the taste, smell and color of many food products, and thus influence consumers’ choices. However, in recent years, MRPs have been linked to the increasing prevalence of diet- and inflammation-related non-communicable diseases including food allergy. Although during the last years a better understanding of immunogenicity of MRPs has been achieved, still only little is known about the structural/chemical characteristics predisposing MRPs to interact with antigen presenting cells (APCs. This report provides a comprehensive review of recent studies on the influence of the Maillard reaction on the immunogenicity and allergenicity of food proteins.

  17. Food Processing: The Influence of the Maillard Reaction on Immunogenicity and Allergenicity of Food Proteins.

    Science.gov (United States)

    Teodorowicz, Malgorzata; van Neerven, Joost; Savelkoul, Huub

    2017-08-04

    The majority of foods that are consumed in our developed society have been processed. Processing promotes a non-enzymatic reaction between proteins and sugars, the Maillard reaction (MR). Maillard reaction products (MRPs) contribute to the taste, smell and color of many food products, and thus influence consumers' choices. However, in recent years, MRPs have been linked to the increasing prevalence of diet- and inflammation-related non-communicable diseases including food allergy. Although during the last years a better understanding of immunogenicity of MRPs has been achieved, still only little is known about the structural/chemical characteristics predisposing MRPs to interact with antigen presenting cells (APCs). This report provides a comprehensive review of recent studies on the influence of the Maillard reaction on the immunogenicity and allergenicity of food proteins.

  18. Quality changes in krill and krill products during their manufacturing process

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Jacobsen, Charlotte; Bruheim, Inge

    The main objective of this study is to a) investigate the effect of temperature towards the non-enzymatic browning reactions and lipid oxidation in krill products sampled at different stages during their manufacturing process. In order to further investigate this, a simple model system comprising...... amino acids (leucine, isoleucine, valine, methionine and lysine) was prepared with addition of lipid (saturated and α, β-unsaturated aldehydes) or non-enzymatic (Strecker aldehydes and pyrazine) derived volatiles. Therefore, the secondary objective is to investigate if the occurrence of non......-enzymatic browning reactions and lipid oxidation in krill products during their manufacturing process. The occurrence of these reactions could be observed in krill meal and this was ascribed to the presence of carbonyl compounds derived lipid oxidation products. The presence of a high level of non...

  19. Mineralogical study of brown olivine in Northwest Africa 1950 shergottite and implications for the formation mechanism of iron nanoparticles

    Science.gov (United States)

    Takenouchi, Atsushi; Mikouchi, Takashi; Kogure, Toshihiro

    2017-12-01

    Martian meteorites, in particular shergottites, contain darkened olivine (so-called "brown olivine") whose color is induced by iron nanoparticles formed in olivine during a shock event. The formation process and conditions of brown olivine have been discussed in the Northwest Africa 2737 (NWA 2737) chassignite. However, formation conditions of brown olivine in NWA 2737 cannot be applied to shergottites because NWA 2737 has a different shock history from that of shergottites. Therefore, this study observed brown olivine in the NWA 1950 shergottite and discusses the general formation process and conditions of brown olivine in shergottites. Our observation of NWA 1950 revealed that olivine is heterogeneously darkened between and within grains different from brown olivine in NWA 2737. XANES analysis showed that brown olivine contains small amounts of Fe3+ and TEM/STEM observation revealed that there is no SiO-rich phase around iron metal nanoparticles. These observations indicate that iron nanoparticles were formed by a disproportionation reaction of olivine (3Fe2+olivine → Fe0metal + 2Fe3+olivine + Volivine, where Volivine means a vacancy in olivine). Some parts of brown olivine show lamellar textures in SEM observation and Raman peaks in addition to those expected for olivine, implying that brown olivine experienced a phase transition (to e.g., ringwoodite). In order to induce heterogeneous darkening, heterogeneous high temperature of about 1500-1700 K and shock duration of at least 90 ms are required. This heterogeneous high temperature resulted in high postshock temperature (>900 K) inducing back-transformation of most high-pressure phases. Therefore, in spite of lack of high-pressure phases, NWA 1950 (= Martian meteorites with brown olivine) experienced higher pressure and temperature compared to other highly shocked meteorite groups.

  20. Kinetics of browning and correlations between browning degree and pyrazine compounds in l-ascorbic acid/acidic amino acid model systems.

    Science.gov (United States)

    Yu, Ai-Nong; Zhou, Yong-Yan; Yang, Yi-Ni

    2017-04-15

    The kinetics of browning and the correlation between browning products (BPs) and pyrazine compounds were investigated by heating equimolar l-ascorbic acid (ASA)/acidic amino acids under weak alkaline conditions at 120-150°C for 10-120min. The formations of BPs and pyrazine compounds from the reaction were monitored by UV-vis and SPME-GC-FID, respectively. The formation of BPs in both ASA/l-glutamic acid and ASA/l-aspartic acid model reaction systems followed zero order reaction kinetics with activation energies (E a ) of 90.13 and 93.38kJ/mol, respectively. ASA/l-aspartic acid browned at a slightly higher rate than ASA/l-glutamic acid. The total concentration of pyrazine compounds was highly and positively correlated with that of BPs. Based on the observed kinetic data, the formation mechanisms of BPs and pyrazine compounds were proposed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. The effect of thermal treatment on the quality changes of Antartic krill meal during the manufacturing process: High processing temperatures decrease product quality

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Bruheim, Inge; Ale, Marcel Tutor

    2015-01-01

    The quality of krill products is influenced by their manufacturing process and could be evaluated by their degradation products from lipid oxidation and non-enzymatic browning reactions. The main objectives of this study were: (i) to investigate the effect of thermal treatment on these two reacti...

  2. Brown algae hydrolysis in 1-n-butyl-3-methylimidazolium chloride with mineral acid catalyst system.

    Science.gov (United States)

    Malihan, Lenny B; Nisola, Grace M; Chung, Wook-Jin

    2012-08-01

    The amenability of three brown algal species, Sargassum fulvellum, Laminaria japonica and Undaria pinnatifida, to hydrolysis were investigated using the ionic liquid (IL), 1-n-butyl-3-methylimidazolium chloride ([BMIM]Cl). Compositional analyses of the brown algae reveal that sufficient amounts of sugars (15.5-29.4 wt.%) can be recovered. Results from hydrolysis experiments show that careful selection of the type of mineral acid as catalyst and control of acid loading could maximize the recovery of sugars. Optimal reaction time and temperature were determined from the kinetic studies on the sequential reducing sugar (TRS) formation and degradation. Optimal reaction times were determined based on the extent of furfurals formation as TRS degradation products. X-ray diffraction and environmental scanning electron microscopy confirmed the suitability of [BMIM]Cl as solvent for the hydrolysis of the three brown algae. Overall results show the potential of brown algae as renewable energy resources for the production of valuable chemicals and biofuels. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. The unified theory of nuclear reactions

    International Nuclear Information System (INIS)

    Tobocman, W.

    A unified nuclear reaction theory is a formalism for the scattering reactions of many-body nuclear systems which is capable of describing both direct interaction and compound nucleus formation processes. The Feshbach projection operator formalism is the original unified nuclear reaction theory. An alternative unified nuclear reaction theory called the X-matrix formalism is described. The X-matrix formalism is a generalization of the Brown-de Dominicis formalism. It does not require projection operators and is readly applied to rearrangement collisions

  4. A Perspective on Reagent Diversity and Non-covalent Binding of Reactive Carbonyl Species (RCS and Effector Reagents in Non-enzymatic Glycation (NEG: Mechanistic Considerations and Implications for Future Research

    Directory of Open Access Journals (Sweden)

    Kenneth J. Rodnick

    2017-06-01

    Full Text Available This perspective focuses on illustrating the underappreciated connections between reactive carbonyl species (RCS, initial binding in the nonenzymatic glycation (NEG process, and nonenzymatic covalent protein modification (here termed NECPM. While glucose is the central species involved in NEG, recent studies indicate that the initially-bound glucose species in the NEG of human hemoglobin (HbA and human serum albumin (HSA are non-RCS ring-closed isomers. The ring-opened glucose, an RCS structure that reacts in the NEG process, is most likely generated from previously-bound ring-closed isomers undergoing concerted acid/base reactions while bound to protein. The generation of the glucose RCS can involve concomitantly-bound physiological species (e.g., inorganic phosphate, water, etc.; here termed effector reagents. Extant NEG schemes do not account for these recent findings. In addition, effector reagent reactions with glucose in the serum and erythrocyte cytosol can generate RCS (e.g., glyoxal, glyceraldehyde, etc.. Recent research has shown that these RCS covalently modify proteins in vivo via NECPM mechanisms. A general scheme that reflects both the reagent and mechanistic diversity that can lead to NEG and NECPM is presented here. A perspective that accounts for the relationships between RCS, NEG, and NECPM can facilitate the understanding of site selectivity, may help explain overall glycation rates, and may have implications for the clinical assessment/control of diabetes mellitus. In view of this perspective, concentrations of ribose, fructose, Pi, bicarbonate, counter ions, and the resulting RCS generated within intracellular and extracellular compartments may be of importance and of clinical relevance. Future research is also proposed.

  5. Whither do the microlensing Brown Dwarfs rove?

    CERN Document Server

    De Rújula, Alvaro; Mollerach, S; Roulet, Esteban; de Rujula, A; Giudice, G; Mollerach, S; Roulet, E

    1995-01-01

    The EROS and MACHO collaborations have reported observations of light curves of stars in the Large Magellanic Cloud that are compatible with gravitational microlensing by intervening massive objects, presumably Brown-Dwarf stars. The OGLE and MACHO teams have also seen similar events in the direction of the galactic Bulge. Current data are insufficient to decide whether the Brown-Dwarfs are dark-matter constituents of the non-luminous galactic Halo, or belong to a more conventional population, such as that of faint stars in the galactic Spheroid, in its Thin or Thick Disks, or in their possible LMC counterparts. We discuss in detail how further observations of microlensing rates and of the moments of the distribution of event durations, can help resolve the issue of the Brown-Dwarf location, and eventually provide information on the mass function of the dark objects.

  6. Reaction Automata

    OpenAIRE

    Okubo, Fumiya; Kobayashi, Satoshi; Yokomori, Takashi

    2011-01-01

    Reaction systems are a formal model that has been introduced to investigate the interactive behaviors of biochemical reactions. Based on the formal framework of reaction systems, we propose new computing models called reaction automata that feature (string) language acceptors with multiset manipulation as a computing mechanism, and show that reaction automata are computationally Turing universal. Further, some subclasses of reaction automata with space complexity are investigated and their la...

  7. Brown adipogenesis of mouse embryonic stem cells in alginate microstrands

    Science.gov (United States)

    Unser, Andrea Mannarino

    The ability of brown adipocytes (fat cells) to dissipate energy as heat shows great promise for the treatment of obesity and other metabolic disorders. Employing pluripotent stem cells, with an emphasis on directed differentiation, may overcome many issues currently associated with primary fat cell cultures. However, brown adipocytes are difficult to transplant in vivo due to the instability of fat, in terms of necrosis and neovascularization, once injected. Thus, 3D cell culture systems that have the potential to mimic adipogenic microenvironments are needed, not only to advance brown fat implantation, but also to better understand the role of brown adipocytes in treating obesity. To address this need, we created 3D "Brown-Fat-in-Microstrands" by microfluidic synthesis of alginate hydrogel microstrands that encapsulated cells and directly induced cell differentiation into brown adipocytes, using mouse embryonic stem cells (ESCs) as a model of pluripotent stem cells and brown preadipocytes as a positive control. The effect of hydrogel formation parameters on brown adipogenesis was studied, leading to the establishment of "Brown-Fat-in-Microstrands". Brown adipocyte differentiation within microstrands was confirmed by lipid droplet accumulation, immunocytochemistry and qPCR analysis of gene expression of brown adipocyte marker uncoupling protein 1 (UCP1) in addition to adipocyte marker expression. Compared to a 2D approach, 3D differentiated "Brown-Fat-in-Microstrands" exhibited higher level of brown adipocyte marker expression. The functional analysis of "Brown-Fat-in-Microstrands" was attempted by measuring the mitochondrial activity of ESC-differentiated brown adipocytes in 3D using Seahorse XF24 3 Extracellular Flux Analyzer. The ability to create "Brown-Fat-in-Microstrands" from pluripotent stem cells opens up a new arena to understanding brown adipogenesis and its implications in obesity and metabolic disorders.

  8. Brown dwarfs in retrogradely precessing cataclysmic variables?

    Directory of Open Access Journals (Sweden)

    Martin E.L.

    2011-07-01

    Full Text Available We compare Smoothed Particle Hydrodynamic simulations of retrogradely precessing accretion disks that have a white dwarf primary and a main sequence secondary with observational data and with theory on retrograde precession via tidal torques like those by the Moon and the Sun on the Earth [1, 2]. Assuming the primary does not accrete much of the mass lost from the secondary, we identify the theoretical low mass star/brown dwarf boundary. We find no observational candidates in our study that could qualify as brown dwarfs.

  9. Brown tumor of mandible with primary hyperparathyroidism

    International Nuclear Information System (INIS)

    Ali, S.K.; Khan, F.A.; Siddiq, A.; Hanif, M.S.

    2011-01-01

    Parathyroid hormone (PTH) is secreted and released by the parathyroid glands, the activity of which is controlled by the ionized serum calcium level. Increased PTH secretion results in hyperparathyroidism. Hyperparathyroidism is classified as primary, secondary and tertiary types. Primary hyperparathyroidism is characterized by increased parathyroid hormone secretion occurring as a result of abnormality in one or more of the parathyroid glands. Brown tumors are non-neoplastic lesions as a result of abnormal bone metabolism in cases of hyperparathyroidism, creating a local destructive phenomenon. A rare case of a young female patient with brown tumors in her mandible associated with primary hyperparathyroidism, is reported. (author)

  10. Briquetting of Coke-Brown Coal Mixture

    Directory of Open Access Journals (Sweden)

    Ïurove Juraj

    1998-09-01

    Full Text Available The paper presents the results of the research of briquetting a coke-brown coal composite The operation consists of the feeding crushed coal and coke to moulds and pressing into briquettes which have been made in the Laboratories at the Mining Faculty of Technical University of Košice (Slovakia. In this research, all demands will be analyzed including the different aspects of the mechanical quality of briquettes, the proportion of fine pulverulent coal and coke in bricks, the requirements for briquetting the coke-brown coal materials.

  11. Impact of different alginate lyases on combined cellulase–lyase saccharification of brown seaweed

    DEFF Research Database (Denmark)

    Manns, Dirk Martin; Nyffenegger, Christian; Saake, B.

    2016-01-01

    -guluronic acid. When applied together with a fungal cellulase preparation (Cellic®CTec2) at pH 6 and 40 °C on a glucan rich brown seaweed Laminaria digitata the viscosity decreased in the initial minutes while measurable alginate degradation occurred primarily within the first 1–2 hours of reaction. Whereas FALy...... solubilization of sulfated fucoidan, whereas most of the nitrogen was recovered in the residual seaweed solids....

  12. Variation in oxalate and oxalate decarboxylase production by six species of brown and white rot fungi

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Oliver, Jason; Howell, Caitlin

    cell lumen where it quickly dissociates into hydrogen ions and oxalate, resulting in a pH decrease of the environment, and oxalate-cation complexes. Generally, brown rot fungi accumulate larger quantities of oxalic acid in the wood than white rot fungi. The amount of oxalic acid has been shown to vary......  Oxalic acid (C2O4H2), the strongest of the organic acids is produced by both brown and white rot decay fungi and has been connected to various aspects of brown- and white rot decay including the Fenton reaction (Green and Highley, 1997; Munir et al.,2001). Oxalic acid is secreted into the wood...

  13. Alanine-dependent reactions of 5'-deoxypyridoxal in water.

    Science.gov (United States)

    Go, Maybelle K; Richard, John P

    2008-12-01

    The non-enzymatic reaction of 5'-deoxypyridoxal (DPL) with l-alanine in water at 25 degrees C was investigated. DPL reacts with alanine to form an imine, which then undergoes deprotonation at the alpha-amino carbon of alanine to form a resonance delocalized DPL-stabilized carbanion. At early reaction times the only detectable products are pyruvate and the dimeric species formed by addition of the alpha-pyridine stabilized carbanion to DPL. No Claisen-type products of addition of the alpha-amino carbanion to DPL, as was previously reported to form from the reaction between DPL and glycine [K. Toth, T.L. Amyes, J.P. Richard, J.P.G. Malthouse, M.E. Ni Beilliu, J. Am. Chem. Soc. 126 (2004) 10538-10539], are observed. The electrophile reacts instead at the alpha-pyridyl carbon. This dimer is in chemical equilibrium with reactants. At longer reaction times about 50% of DPL is converted to 5'-deoxypyridoxamine, the thermodynamically favored product of formal transamination of DPL.

  14. Egg-Citing! Isolation of Protoporphyrin IX from Brown Eggshells and Its Detection by Optical Spectroscopy and Chemiluminescence

    Science.gov (United States)

    Dean, Michelle L.; Miller, Tyson A.; Bruckner, Christian

    2011-01-01

    A simple and cost-effective laboratory experiment is described that extracts protoporphyrin IX from brown eggshells. The porphyrin is characterized by UV-vis and fluorescence spectroscopy. A chemiluminescence reaction (peroxyoxalate ester fragmentation) is performed that emits light in the UV region. When the porphyrin extract is added as a fluor…

  15. Use of Brown Algae to Demonstrate Natural Products Techniques.

    Science.gov (United States)

    Porter, Lee A.

    1985-01-01

    Background information is provided on the natural products found in marine organisms in general and the brown algae in particular. Also provided are the procedures needed to isolate D-mannitol (a primary metabolite) and cholesterol from brown algae. (JN)

  16. Involvement of phenoloxidase in browning during grinding of Tenebrio molitor larvae.

    Science.gov (United States)

    Janssen, Renske H; Lakemond, Catriona M M; Fogliano, Vincenzo; Renzone, Giovanni; Scaloni, Andrea; Vincken, Jean-Paul

    2017-01-01

    Insects are investigated as alternative protein source to meet the increasing demand for proteins in the future. Enzymatic browning occurring during grinding of insect and subsequent extraction of proteins can influence the proteins' properties, but it is unclear which enzymes are responsible for this phenomenon. This study was performed on larvae of three commonly used insect species, namely Tenebrio molitor, Alphitobius diaperinus and Hermetia illucens. Oxygen consumption measurements on protein extracts showed activity on L-tyrosine, L-3,4-di-hydroxy-phenylalanine (L-DOPA) and L-dopamine, indicating phenoloxidase as a key player in browning. Furthermore, no reaction on 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) was observed, ruling out an important contribution of laccase to browning. The browning reaction was most prominent at pH 6 for T. molitor and A. diaperinus, and 7 for H. illucens. As the enzyme activity of H. illucens was the lowest with the darkest color formation, this was likely caused by another factor. The activity of phenoloxidase was confirmed for T. molitor and A. diaperinus by activity measurements after fractionation by anion-exchange chromatography. Color measurements showed the presence of activity on both L-DOPA and L-tyrosine in the same fractions. Both substrates were converted into dopachrome after incubation with enzyme-enriched fractions. No DOPA-decarboxylase, tyrosine hydroxylase and peroxidase activities were observed. By using native PAGE with L-DOPA as staining-solution, active T. molitor protein bands were resolved and characterized, identifying a tyrosinase/phenoloxidase as the active enzyme species. All together, these data confirmed that tyrosinase is an important enzyme in causing enzymatic browning in T. molitor and likely in A. diaperinus.

  17. Involvement of phenoloxidase in browning during grinding of Tenebrio molitor larvae.

    Directory of Open Access Journals (Sweden)

    Renske H Janssen

    Full Text Available Insects are investigated as alternative protein source to meet the increasing demand for proteins in the future. Enzymatic browning occurring during grinding of insect and subsequent extraction of proteins can influence the proteins' properties, but it is unclear which enzymes are responsible for this phenomenon. This study was performed on larvae of three commonly used insect species, namely Tenebrio molitor, Alphitobius diaperinus and Hermetia illucens. Oxygen consumption measurements on protein extracts showed activity on L-tyrosine, L-3,4-di-hydroxy-phenylalanine (L-DOPA and L-dopamine, indicating phenoloxidase as a key player in browning. Furthermore, no reaction on 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid was observed, ruling out an important contribution of laccase to browning. The browning reaction was most prominent at pH 6 for T. molitor and A. diaperinus, and 7 for H. illucens. As the enzyme activity of H. illucens was the lowest with the darkest color formation, this was likely caused by another factor. The activity of phenoloxidase was confirmed for T. molitor and A. diaperinus by activity measurements after fractionation by anion-exchange chromatography. Color measurements showed the presence of activity on both L-DOPA and L-tyrosine in the same fractions. Both substrates were converted into dopachrome after incubation with enzyme-enriched fractions. No DOPA-decarboxylase, tyrosine hydroxylase and peroxidase activities were observed. By using native PAGE with L-DOPA as staining-solution, active T. molitor protein bands were resolved and characterized, identifying a tyrosinase/phenoloxidase as the active enzyme species. All together, these data confirmed that tyrosinase is an important enzyme in causing enzymatic browning in T. molitor and likely in A. diaperinus.

  18. A non-enzymic browning induced by gamma cobalt-60 irradiation and heating in a fructose-alanine model system

    International Nuclear Information System (INIS)

    Bachman, S.; Zegota, A.; Zegota, H.

    1981-01-01

    The Maillard browning reaction between reducing sugars and amino compounds is important in food chemistry and may considerably affect the colour, aroma and nutritional value of food after thermal processing. In this study, the effect of irradiation combined with heating on the course of browning reaction in the model system of aqueous solution of fructose (0.03M) and alanine (0.01M) was investigated. The optical absorption spectra recorded for irradiated and heated solution of fructose-alanine were different from those of only irradiated or only heated solution. The brown colour of the samples is caused by the extension of the tail-end absorption into the visible region of the spectrum. No absorption maximum appears in the visible range. The heating of irradiated fructose solution with non-irradiated alanine develops markedly more intensive browning than that of the heating of irradiated alanine solution with non-irradiated fructose. The products of fructose radiolysis are responsible for the acceleration of browning in the fructose-alanine system. (author)

  19. Trustworthy-looking face meets brown eyes.

    Directory of Open Access Journals (Sweden)

    Karel Kleisner

    Full Text Available We tested whether eye color influences perception of trustworthiness. Facial photographs of 40 female and 40 male students were rated for perceived trustworthiness. Eye color had a significant effect, the brown-eyed faces being perceived as more trustworthy than the blue-eyed ones. Geometric morphometrics, however, revealed significant correlations between eye color and face shape. Thus, face shape likewise had a significant effect on perceived trustworthiness but only for male faces, the effect for female faces not being significant. To determine whether perception of trustworthiness was being influenced primarily by eye color or by face shape, we recolored the eyes on the same male facial photos and repeated the test procedure. Eye color now had no effect on perceived trustworthiness. We concluded that although the brown-eyed faces were perceived as more trustworthy than the blue-eyed ones, it was not brown eye color per se that caused the stronger perception of trustworthiness but rather the facial features associated with brown eyes.

  20. Fucoidans — sulfated polysaccharides of brown algae

    Science.gov (United States)

    Usov, Anatolii I.; Bilan, M. I.

    2009-08-01

    The methods of isolation of fucoidans and determination of their chemical structures are reviewed. The fucoidans represent sulfated polysaccharides of brown algae, the composition of which varies from simple fucan sulfates to complex heteropolysaccharides. The currently known structures of such biopolymers are presented. A variety of the biological activities of fucoidans is briefly summarised.

  1. Nixon's "Southern Strategy" and Forces against Brown

    Science.gov (United States)

    Brown, Frank

    2004-01-01

    Richard M. Nixon, the United States President in 1968 gave birth to the modern reform movement through public vouchers and other educational reform measures under his "Southern Strategy" that was designed to gain the votes of individuals who oppose school desegregation. The political activities in school desegregation after Brown by the…

  2. Brown midrib sorghum deserves a look

    Science.gov (United States)

    Forage sorghum varieties have been developed to allow them to thrive under low moisture and poor soil conditions while producing adequate amounts of forage. In addition, newer varieties, such as the brown midrib (BMR) hybrids, can be alternatives to conventional varieties as they contain less lignin...

  3. Browning and thermogenic programing of adipose tissue.

    Science.gov (United States)

    Kiefer, Florian W

    2016-08-01

    The view of adipose tissue as solely a fat storing organ has changed significantly over the past two decades with the discoveries of numerous adipocyte-secreted factors, so called adipokines, and their endocrine functions throughout the body. The newest chapter added to this story is the finding that adipose tissue is also a thermogenic organ contributing to energy expenditure through actions of specialized, heat-producing brown or beige adipocytes. In contrast to bone fide brown adipocytes, beige cells develop within white fat depots in response to various stimuli such as prolonged cold exposure, underscoring the great thermogenic plasticity of adipose tissue. The energy dissipating properties of beige and/or brown adipocytes hold great promise as a novel therapeutic concept against obesity and related complications. Hence, identifying the specific thermogenic adipocyte populations in humans and their pathways of activation are key milestones of current metabolism research. Here we will discuss the recent advances in the understanding of the molecular and physiological mechanisms of adipose tissue browning. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Phospholipids of New Zealand Edible Brown Algae.

    Science.gov (United States)

    Vyssotski, Mikhail; Lagutin, Kirill; MacKenzie, Andrew; Mitchell, Kevin; Scott, Dawn

    2017-07-01

    Edible brown algae have attracted interest as a source of beneficial allenic carotenoid fucoxanthin, and glyco- and phospholipids enriched in polyunsaturated fatty acids. Unlike green algae, brown algae contain no or little phosphatidylserine, possessing an unusual aminophospholipid, phosphatidyl-O-[N-(2-hydroxyethyl) glycine], PHEG, instead. When our routinely used technique of 31 P-NMR analysis of phospholipids was applied to the samples of edible New Zealand brown algae, a number of signals corresponding to unidentified phosphorus-containing compounds were observed in total lipids. NI (negative ion) ESI QToF MS spectra confirmed the presence of more familiar phospholipids, and also suggested the presence of PHEG or its isomers. The structure of PHEG was confirmed by comparison with a synthetic standard. An unusual MS fragmentation pattern that was also observed prompted us to synthesise a number of possible candidates, and was found to follow that of phosphatidylhydroxyethyl methylcarbamate, likely an extraction artefact. An unexpected outcome was the finding of ceramidephosphoinositol that has not been reported previously as occurring in brown algae. An uncommon arsenic-containing phospholipid has also been observed and quantified, and its TLC behaviour studied, along with that of the newly synthesised lipids.

  5. Civil Rights Law and the Brown Decision.

    Science.gov (United States)

    Greenberg, Jack

    The Brown decision of 1954 was the product of a planned program of litigation begun in the late 1920s and the early 1930s by a group of Black lawyers. Their work would not have succeeded if the ethos of the United States had not been changing simultaneously. The growth of a climate more conducive to civil rights is reflected in the presidential…

  6. Maxillary brown tumour: unusual presentation of parathyroid ...

    African Journals Online (AJOL)

    This is a report of a maxillary brown tumour caused by primary hyperparathyroidism (HPT) secondary to parathyroid carcinoma. A 62-year-old man presented with a large swelling in the right maxilla, which caused right-sided nasal obstruction, intermittent bleeding and diplopia. A computed tomography scan demonstrated ...

  7. Gas exchange and brown heart in conference pears

    NARCIS (Netherlands)

    Otma, E.C.; Peppelenbos, H.W.

    2003-01-01

    Brown heart is a tissue disorder found in Conference pears during CA storage. Differences in susceptibility for brown heart have been found between countries, orchards, harvest dates and storage conditions. One hypothesis is that brown heart is caused by increased internal CO2. This research

  8. Search for brown dwarfs in the IRAS data bases

    International Nuclear Information System (INIS)

    Low, F.J.

    1986-01-01

    A report is given on the initial searches for brown dwarf stars in the IRAS data bases. The paper was presented to the workshop on 'Astrophysics of brown dwarfs', Virginia, USA, 1985. To date no brown dwarfs have been discovered in the solar neighbourhood. Opportunities for future searches with greater sensitivity and different wavelengths are outlined. (U.K.)

  9. 49 CFR 173.216 - Asbestos, blue, brown or white.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Asbestos, blue, brown or white. 173.216 Section... Class 7 § 173.216 Asbestos, blue, brown or white. (a) Asbestos, blue, brown or white, includes each of the following hydrated mineral silicates: chrysolite, crocidolite, amosite, anthophyllite asbestos...

  10. A Panchromatic View of Brown Dwarf Aurorae

    Energy Technology Data Exchange (ETDEWEB)

    Pineda, J. Sebastian [University of Colorado Boulder, Laboratory for Atmospheric and Space Physics, 3665 Discovery Drive, Boulder CO, 80303 (United States); Hallinan, Gregg; Kao, Melodie M. [California Institute of Technology, Department of Astronomy, 1200 E. California Avenue, Pasadena CA, 91125 (United States)

    2017-09-01

    Stellar coronal activity has been shown to persist into the low-mass star regime, down to late M-dwarf spectral types. However, there is now an accumulation of evidence suggesting that at the end of the main sequence, there is a transition in the nature of the magnetic activity from chromospheric and coronal to planet-like and auroral, from local impulsive heating via flares and MHD wave dissipation to energy dissipation from strong large-scale magnetospheric current systems. We examine this transition and the prevalence of auroral activity in brown dwarfs through a compilation of multiwavelength surveys of magnetic activity, including radio, X-ray, and optical. We compile the results of those surveys and place their conclusions in the context of auroral emission as a consequence of large-scale magnetospheric current systems that accelerate energetic electron beams and drive the particles to impact the cool atmospheric gas. We explore the different manifestations of auroral phenomena, like H α , in brown dwarf atmospheres and define their distinguishing characteristics. We conclude that large-amplitude photometric variability in the near-infrared is most likely a consequence of clouds in brown dwarf atmospheres, but that auroral activity may be responsible for long-lived stable surface features. We report a connection between auroral H α emission and quiescent radio emission in electron cyclotron maser instability pulsing brown dwarfs, suggesting a potential underlying physical connection between quiescent and auroral emissions. We also discuss the electrodynamic engines powering brown dwarf aurorae and the possible role of satellites around these systems both to power the aurorae and seed the magnetosphere with plasma.

  11. A Panchromatic View of Brown Dwarf Aurorae

    Science.gov (United States)

    Pineda, J. Sebastian; Hallinan, Gregg; Kao, Melodie M.

    2017-09-01

    Stellar coronal activity has been shown to persist into the low-mass star regime, down to late M-dwarf spectral types. However, there is now an accumulation of evidence suggesting that at the end of the main sequence, there is a transition in the nature of the magnetic activity from chromospheric and coronal to planet-like and auroral, from local impulsive heating via flares and MHD wave dissipation to energy dissipation from strong large-scale magnetospheric current systems. We examine this transition and the prevalence of auroral activity in brown dwarfs through a compilation of multiwavelength surveys of magnetic activity, including radio, X-ray, and optical. We compile the results of those surveys and place their conclusions in the context of auroral emission as a consequence of large-scale magnetospheric current systems that accelerate energetic electron beams and drive the particles to impact the cool atmospheric gas. We explore the different manifestations of auroral phenomena, like Hα, in brown dwarf atmospheres and define their distinguishing characteristics. We conclude that large-amplitude photometric variability in the near-infrared is most likely a consequence of clouds in brown dwarf atmospheres, but that auroral activity may be responsible for long-lived stable surface features. We report a connection between auroral Hα emission and quiescent radio emission in electron cyclotron maser instability pulsing brown dwarfs, suggesting a potential underlying physical connection between quiescent and auroral emissions. We also discuss the electrodynamic engines powering brown dwarf aurorae and the possible role of satellites around these systems both to power the aurorae and seed the magnetosphere with plasma.

  12. The Halogenated Metabolism of Brown Algae (Phaeophyta, Its Biological Importance and Its Environmental Significance

    Directory of Open Access Journals (Sweden)

    Stéphane La Barre

    2010-03-01

    Full Text Available Brown algae represent a major component of littoral and sublittoral zones in temperate and subtropical ecosystems. An essential adaptive feature of this independent eukaryotic lineage is the ability to couple oxidative reactions resulting from exposure to sunlight and air with the halogenations of various substrates, thereby addressing various biotic and abiotic stresses i.e., defense against predators, tissue repair, holdfast adhesion, and protection against reactive species generated by oxidative processes. Whereas marine organisms mainly make use of bromine to increase the biological activity of secondary metabolites, some orders of brown algae such as Laminariales have also developed a striking capability to accumulate and to use iodine in physiological adaptations to stress. We review selected aspects of the halogenated metabolism of macrophytic brown algae in the light of the most recent results, which point toward novel functions for iodide accumulation in kelps and the importance of bromination in cell wall modifications and adhesion properties of brown algal propagules. The importance of halogen speciation processes ranges from microbiology to biogeochemistry, through enzymology, cellular biology and ecotoxicology.

  13. The halogenated metabolism of brown algae (Phaeophyta), its biological importance and its environmental significance.

    Science.gov (United States)

    La Barre, Stéphane; Potin, Philippe; Leblanc, Catherine; Delage, Ludovic

    2010-03-31

    Brown algae represent a major component of littoral and sublittoral zones in temperate and subtropical ecosystems. An essential adaptive feature of this independent eukaryotic lineage is the ability to couple oxidative reactions resulting from exposure to sunlight and air with the halogenations of various substrates, thereby addressing various biotic and abiotic stresses i.e., defense against predators, tissue repair, holdfast adhesion, and protection against reactive species generated by oxidative processes. Whereas marine organisms mainly make use of bromine to increase the biological activity of secondary metabolites, some orders of brown algae such as Laminariales have also developed a striking capability to accumulate and to use iodine in physiological adaptations to stress. We review selected aspects of the halogenated metabolism of macrophytic brown algae in the light of the most recent results, which point toward novel functions for iodide accumulation in kelps and the importance of bromination in cell wall modifications and adhesion properties of brown algal propagules. The importance of halogen speciation processes ranges from microbiology to biogeochemistry, through enzymology, cellular biology and ecotoxicology.

  14. Hydrocarbon fuels from brown grease: Moving from the research laboratory toward an industrial process

    Science.gov (United States)

    Pratt, Lawrence M.; Strothers, Joel; Pinnock, Travis; Hilaire, Dickens Saint; Bacolod, Beatrice; Cai, Zhuo Biao; Sim, Yoke-Leng

    2017-04-01

    Brown grease is a generic term for the oily solids and semi-solids that accumulate in the sewer system and in sewage treatment plants. It has previously been shown that brown grease undergoes pyrolysis to form a homologous series of alkanes and 1-alkenes between 7 and 17 carbon atoms, with smaller amounts of higher hydrocarbons and ketones up to about 30 carbon atoms. The initial study was performed in batch mode on a scale of up to 50 grams of starting material. However, continuous processes are usually more efficient for large scale production of fuels and commodity chemicals. This work describes the research and development of a continuous process. The first step was to determine the required reactor temperature. Brown grease consists largely of saturated and unsaturated fatty acids, and they react at different rates, and produce different products and intermediates. Intermediates include ketones, alcohols, and aldehydes, and Fe(III) ion catalyzes at least some of the reactions. By monitoring the pyrolysis of brown grease, its individual components, and intermediates, it was determined that a reactor temperature of at least 340 °C is required. A small scale (1 L) continuous stirred tank reactor was built and its performance is described.

  15. Generalised Brown Clustering and Roll-up Feature Generation

    DEFF Research Database (Denmark)

    Derczynski, Leon; Chester, Sean

    2016-01-01

    Brown clustering is an established technique, used in hundreds of computational linguistics papers each year, to group word types that have similar distributional information. It is unsupervised and can be used to create powerful word representations for machine learning. Despite its improbable...... active set size. Moreover, the generalisation permits a novel approach to feature selection from Brown clusters: We show that the standard approach of shearing the Brown clustering output tree at arbitrary bitlengths is lossy and that features should be chosen instead by rolling up Generalised Brown...... hierarchies. The generalisation and corresponding feature generation is more principled, challenging the way Brown clustering is currently understood and applied....

  16. Analysis of volatiles in brown rice, germinated brown rice, and selenised germinated brown rice during storage at different vacuum levels.

    Science.gov (United States)

    Liu, Kunlun; Zhao, Shuang; Li, Yang; Chen, Fusheng

    2017-10-09

    The quality of nutritionally enhanced foods can be determined by evaluating changes in the volatile compounds produced in these foods over time. In this work, selenium-enriched germinated brown rice (Se-GBR), germinated brown rice (GBR), and brown rice (BR) stored under 90% relative humidity, 38 °C, and various vacuum levels were investigated. The relative abundance and differences of volatile compounds in Se-GBR, GBR, and BR over various storage periods were detected. The correlation of volatile compound abundance with vacuum level and storage time was analysed using principal component analysis (PCA). Volatile compounds in the three samples were quantified at various storage periods (0, 90 and 150 days). Approximately 100 volatile compounds and eight species were identified and classified. Various proportions or types of volatile compounds were found in each sample at different sampling times. PCA results showed an isolation of volatile compounds in terms of sampling day and vacuum level at each storage period. Changes in volatile compounds over time and vacuum levels can provide bases for assessing of the nutritional quality of Se-GBR, GBR, and BR. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  17. Effects of salt concentration on the reaction rate of Glc with amino acids, peptides, and proteins.

    Science.gov (United States)

    Yamaguchi, Keiko; Noumi, Yuri; Nakajima, Katsumi; Nagatsuka, Chiharu; Aizawa, Haruko; Nakawaki, Rie; Mizude, Eri; Otsuka, Yuzuru; Homma, Takeshi; Chuyen, Nguyen Van

    2009-11-01

    The reaction between the amino group and the carbonyl group is important in food quality control. Furthermore, advanced glycation end products from foods are considered to relate to aging and diabetes. Thus, it is important to control this reaction. In this study, we investigated the effects of salt concentration on the rates of browning reaction of amino acid, peptides, and proteins. A high concentration of sodium chloride retarded the reaction rate of Glc with amino acids as measured with the absorbance at 470 nm, but did not change the browning rate of Glc with peptides. On the other hand, sodium chloride retarded the browning reaction rate of proteins as measured with polymerization degree or by the loss of Lys. It is hoped that the results of this study will be applied in the control of amino-carbonyl reaction rates in the food industry.

  18. The effects of reactants ratios, reaction temperatures and times on Maillard reaction products of the L-ascorbic acid/L-glutamic acid system

    Directory of Open Access Journals (Sweden)

    Yong-Yan ZHOU

    2016-01-01

    Full Text Available Abstract The transformation law of the Maillard reaction products with three different reactants ratios - equimolar reactants, excess L-glutamic acid and excess L-ascorbic acid reaction respectively, five different temperatures, and different time conditions for the L-ascorbic acid / L-glutamic acid system were investigated. Results showed that, the increase of the reaction time and temperature led to the increase of the browning products, uncoloured intermediate products, as well as aroma compounds. Compared with the equimolar reaction system, the excess L-ascorbic acid reaction system produced more browning products and uncoloured intermediate products, while the aroma compounds production remained the same. In the excess L-glutamic acid system, the uncoloured intermediate products increased slightly, the browning products remained the same, while the aroma compounds increased.

  19. SPECTROSCOPY OF PUTATIVE BROWN DWARFS IN TAURUS

    International Nuclear Information System (INIS)

    Luhman, K. L.; Mamajek, E. E.

    2010-01-01

    Quanz and coworkers have reported the discovery of the coolest known member of the Taurus star-forming complex (L2 ± 0.5), and Barrado and coworkers have identified a possible protostellar binary brown dwarf in the same region. We have performed infrared spectroscopy on the former and the brighter component of the latter to verify their substellar nature. The resulting spectra do not exhibit the strong steam absorption bands that are expected for cool objects, demonstrating that they are not young brown dwarfs. The optical magnitudes and colors for these sources are also indicative of background stars rather than members of Taurus. Although the fainter component of the candidate protostellar binary lacks spectroscopy, we conclude that it is a galaxy rather than a substellar member of Taurus based on its colors and the constraints on its proper motion.

  20. Recommendations related to Browns Ferry Fire

    International Nuclear Information System (INIS)

    1976-02-01

    Based on its review of the events transpiring before, during and after the Browns Ferry fire, the Review Group concludes that the probability of disruptive fires of the magnitude of the Browns Ferry event is small, and that there is no need to restrict operation of nuclear power plants for public safety. However, it is clear that much can and should be done to reduce even further the likelihood of disabling fires and to improve assurance of rapid extinguishment of fires that occur. Consideration should be given also to features that would increase further the ability of nuclear facilities to withstand large fires without loss of important functions should such fires occur. The Review Group believes that improvements, especially in the areas of fire prevention and fire control, can and should be made in most existing facilities

  1. Characterization of Mannuronan C-5-Epimerase Genes from the Brown Alga Laminaria digitata1

    Science.gov (United States)

    Nyvall, Pi; Corre, Erwan; Boisset, Claire; Barbeyron, Tristan; Rousvoal, Sylvie; Scornet, Delphine; Kloareg, Bernard; Boyen, Catherine

    2003-01-01

    Alginate is an industrially important polysaccharide obtained commercially by harvesting brown algae. The final step in alginate biosynthesis, the epimerization of β-1,4-d-mannuronic acid to α-1,4-l-guluronic acid, a structural change that controls the physicochemical properties of the alginate, is catalyzed by the enzyme mannuronan C-5-epimerase. Six different cDNAs with homology to bacterial mannuronan C-5-epimerases were isolated from the brown alga Laminaria digitata (Phaeophyceae). Hydrophobic cluster analysis indicated that the proteins encoded by the L. digitata sequences have important structural similarities to the bacterial mannuronan C-5-epimerases, including conservation of the catalytic site. The expression of the C-5-epimerase genes was examined by northern-blot analysis and reverse transcriptase-polymerase chain reaction in L. digitata throughout a year. Expression was also monitored in protoplast cultures by northern and western blot, reverse transcriptase-polymerase chain reaction, and activity measurements. From both the structural comparisons and the expression pattern, it appears that the cDNAs isolated from L. digitata encode functional mannuronan C-5-epimerases. The phylogenetic relationships of the bacterial and brown algal enzymes and the inferences on the origin of alginate biosynthetic machinery are discussed. PMID:14526115

  2. Finding Brown's peony a sweet attraction

    Science.gov (United States)

    Nan. Vance

    2012-01-01

    I first encountered Brown’s peony (Paeonia brownie) with its verdant, lavender-tinged leaves and elegantly nodding maroon flowers growing among bitterbrush and bunchgrass on the eastern flank of the Oregon Cascades. My first thought was “What is a plant like you doing in a place like this?” It would be natural to visualize this native wild peony as...

  3. SILICATE EVOLUTION IN BROWN DWARF DISKS

    International Nuclear Information System (INIS)

    Riaz, B.

    2009-01-01

    We present a compositional analysis of the 10 μm silicate spectra for brown dwarf disks in the Taurus and Upper Scorpius (UppSco) star-forming regions, using archival Spitzer/Infrared Spectrograph observations. A variety in the silicate features is observed, ranging from a narrow profile with a peak at 9.8 μm, to nearly flat, low-contrast features. For most objects, we find nearly equal fractions for the large-grain and crystalline mass fractions, indicating both processes to be active in these disks. The median crystalline mass fraction for the Taurus brown dwarfs is found to be 20%, a factor of ∼2 higher than the median reported for the higher mass stars in Taurus. The large-grain mass fractions are found to increase with an increasing strength in the X-ray emission, while the opposite trend is observed for the crystalline mass fractions. A small 5% of the Taurus brown dwarfs are still found to be dominated by pristine interstellar medium-like dust, with an amorphous submicron grain mass fraction of ∼87%. For 15% of the objects, we find a negligible large-grain mass fraction, but a >60% small amorphous silicate fraction. These may be the cases where substantial grain growth and dust sedimentation have occurred in the disks, resulting in a high fraction of amorphous submicron grains in the disk surface. Among the UppSco brown dwarfs, only usd161939 has a signal-to-noise ratio high enough to properly model its silicate spectrum. We find a 74% small amorphous grain and a ∼26% crystalline mass fraction for this object.

  4. Multiplicity of viral infection in brown algae

    OpenAIRE

    Stevens, Kim

    2014-01-01

    Brown algae are important primary producers and habitat formers in coastal environments and are believed to have evolved multicellularity independently of the other eukaryotes. The phaeoviruses that infect them form a stable lysogenic relationship with their host via genome integration, but have only been extensively studied in two genera: Ectocarpus and Feldmannia. In this study I aim to improve our understanding of the genetic diversity, host range and distribution of phaeoviruses. Seq...

  5. The Brown School of Public Health.

    Science.gov (United States)

    Cambra, Kris; Wetle, Terrie Fox

    2013-06-04

    The nation's newest school of public health boasts research excellence in aging, obesity, addictions, health care services and policy research, and more. The Brown School of Public Health is home to a variety of master's and doctoral programs, in addition to one of the oldest undergraduate concentrations in community health. The School plays a key role in the development of public policy at the state and national level and implements programs that benefits Rhode Island physicians and their patients.

  6. Drivers of hibernation in the brown bear

    OpenAIRE

    Evans, Alina; Singh, N.J.; Arnemo, Jon Martin; Laske, T.G.; Fröbert, O.; Swenson, Jon; Blanc, S.

    2016-01-01

    Background Hibernation has been a key area of research for several decades, essentially in small mammals in the laboratory, yet we know very little about what triggers or ends it in the wild. Do climatic factors, an internal biological clock, or physiological processes dominate? Using state-of-the-art tracking and monitoring technology on fourteen free-ranging brown bears over three winters, we recorded movement, heart rate (HR), heart rate variability (HRV), body temperature (Tb), physical a...

  7. Nuclear reactions

    International Nuclear Information System (INIS)

    Lane, A.M.

    1980-01-01

    In reviewing work at Harwell over the past 25 years on nuclear reactions it is stated that a balance has to be struck in both experiment and theory between work on cross-sections of direct practical relevance to reactors and on those relevant to an overall understanding of reaction processes. The compound nucleus and direct process reactions are described. Having listed the contributions from AERE, Harwell to developments in nuclear reaction research in the period, work on the optical model, neutron capture theory, reactions at doorway states with fine structure, and sum-rules for spectroscopic factors are considered in more detail. (UK)

  8. Plasma Ascorbic Acid and Non-Enzymatic Antioxidants Level in ...

    African Journals Online (AJOL)

    Free radicals have been implicated in the pathology of several diseases including cataract. Ascorbic acid functions as the major chain breaking antioxidant vitamin in the aqueous phase. Bilirubin, albumin and uric acid are regarded as natural antioxidants. There are conflicting reports on plasma concentrations of these ...

  9. Non-Enzymatic Oligomerization of 3 ', 5 ' Cyclic AMP

    Czech Academy of Sciences Publication Activity Database

    Costanzo, G.; Pino, S.; Timperio, A.M.; Šponer, Judit E.; Sponer, Jiri; Nováková, Olga; Šedo, O.; Zdráhal, Z.; Di Mauro, E.

    2016-01-01

    Roč. 11, č. 11 (2016), č. článku e0165723. E-ISSN 1932-6203 R&D Projects: GA ČR(CZ) GA14-12010S; GA ČR GBP206/12/G151 Institutional support: RVO:68081707 Keywords : template-directed synthesis * nucleoside phosphorylation * montmorillonite catalysis * molecular-structure Subject RIV: BO - Biophysics Impact factor: 2.806, year: 2016

  10. Non-enzymatic palladium recovery on microbial and synthetic surfaces

    DEFF Research Database (Denmark)

    Rotaru, Amelia-Elena; Jiang, Wei; Finster, Kai

    2012-01-01

    The use of microorganisms as support for reduction of dissolved Pd(II) to immobilized Pd(0) nanoparticles is an environmentally friendly approach for Pd recovery from waste. To better understand and engineer Pd(0) nanoparticle synthesis, one has to consider the mechanisms by which Pd(II) is reduced...

  11. Cannabidiol promotes browning in 3T3-L1 adipocytes.

    Science.gov (United States)

    Parray, Hilal Ahmad; Yun, Jong Won

    2016-05-01

    Recruitment of the brown-like phenotype in white adipocytes (browning) and activation of existing brown adipocytes are currently being investigated as a means to combat obesity. Thus, a wide variety of dietary agents that contribute to browning of white adipocytes have been identified. The present study was designed to investigate the effects of cannabidiol (CBD), a major nonpsychotropic phytocannabinoid of Cannabis sativa, on induction of browning in 3T3-L1 adipocytes. CBD enhanced expression of a core set of brown fat-specific marker genes (Ucp1, Cited1, Tmem26, Prdm16, Cidea, Tbx1, Fgf21, and Pgc-1α) and proteins (UCP1, PRDM16, and PGC-1α). Increased expression of UCP1 and other brown fat-specific markers contributed to the browning of 3T3-L1 adipocytes possibly via activation of PPARγ and PI3K. In addition, CBD increased protein expression levels of CPT1, ACSL, SIRT1, and PLIN while down-regulating JNK2, SREBP1, and LPL. These data suggest possible roles for CBD in browning of white adipocytes, augmentation of lipolysis, thermogenesis, and reduction of lipogenesis. In conclusion, the current data suggest that CBD plays dual modulatory roles in the form of inducing the brown-like phenotype as well as promoting lipid metabolism. Thus, CBD may be explored as a potentially promising therapeutic agent for the prevention of obesity.

  12. The nuclear reaction matrix

    International Nuclear Information System (INIS)

    Krenciglowa, E.M.; Kung, C.L.; Kuo, T.T.S.; Osnes, E.; and Department of Physics, State University of New York at Stony Brook, Stony Brook, New York 11794)

    1976-01-01

    Different definitions of the reaction matrix G appropriate to the calculation of nuclear structure are reviewed and discussed. Qualitative physical arguments are presented in support of a two-step calculation of the G-matrix for finite nuclei. In the first step the high-energy excitations are included using orthogonalized plane-wave intermediate states, and in the second step the low-energy excitations are added in, using harmonic oscillator intermediate states. Accurate calculations of G-matrix elements for nuclear structure calculations in the Aapprox. =18 region are performed following this procedure and treating the Pauli exclusion operator Q 2 /sub p/ by the method of Tsai and Kuo. The treatment of Q 2 /sub p/, the effect of the intermediate-state spectrum and the energy dependence of the reaction matrix are investigated in detail. The present matrix elements are compared with various matrix elements given in the literature. In particular, close agreement is obtained with the matrix elements calculated by Kuo and Brown using approximate methods

  13. Nuclear reaction matrix

    International Nuclear Information System (INIS)

    Krenciglowa, E.M.; Kung, C.L.; Kuo, T.T.S.; Osnes, E.

    1975-01-01

    Different definitions of the reaction matrix G appropriate to the calculation of nuclear structure are reviewed and discussed. Qualitative physical arguments are presented in support of a two-step calculation of the G-matrix for finite nuclei. In the first step the high-energy excitations are included using orthogonalized plane-wave intermediate states, and in the second step the low-energy excitations are added in, using harmonic oscillator intermediate states. Accurate calculations of G-matrix elements for nuclear structure calculations in the A approximately 18 region are performed following this procedure and treating the Pauli exclusion operator Q/sub 2p/ by the method of Tsai and Kuo. The treatment of Q/sub 2p/, the effect of the intermediate-state spectrum and the energy dependence of the reaction matrix are investigated in detail. The present matrix elements are compared with various matrix elements given in the literature. In particular, close argument is obtained with the matrix elements calculated by Kuo and Brown using approximate methods

  14. Evaluation of rice mutant lines for resistance to brown planthopper, nilaparvata lugens stall

    International Nuclear Information System (INIS)

    Mugiono

    1985-01-01

    The most important and common insect in rice cultivation in South East Asia is brown planthopper, nilaparvata lugens stall. Seven rice mutant lines produced by the National Atomic Energy Agency, Indonesia, were tested at IRRI, the Philippines for resistance to brown planthopper. Those mutant lines were Atomita 1, 627/10-3/PsJ, Atomita 2 and 627/4-E/PsJ originated from Pelita 1/1 which was irradiated with 0.2 kGy of gamma rays and A227/2/PsJ, A227/3/PsJ and A227/5/PsJ, originated from early maturing mutant A23/PsJ/72K from irradiated Pelita 1/1 which was irradiated with 0.1 kGy of gamma rays. Evaluation of resistance was carried out by seedling bulk screening, honeydew excretion, survival and population build up tests by using brown planthopper biotype 1, 2 and 3. Results of these tests showed that the seven tested mutant lines were resistant to biotype 1 but susceptible to biotype 2. Reaction to biotype 3 showed that six mutant lines tested were moderately resistant and only one mutant of 627/4-E/PsJ was susceptible. Reactions of the mutant lines to biotype 1, 2 and 3 were different from the resistant varieties, Mudgo or ASD-7. This indicated that mutant lines might have gene(s) for resistance which differed from those of resistant varieties. The results showed that resistance to brown planthopper is possible to be introduced in Indonesian rice varieties by means of mutations. (author)

  15. Effect of steam baking on acrylamide formation and browning kinetics of cookies.

    Science.gov (United States)

    Isleroglu, Hilal; Kemerli, Tansel; Sakin-Yilmazer, Melike; Guven, Gonul; Ozdestan, Ozgul; Uren, Ali; Kaymak-Ertekin, Figen

    2012-10-01

    Effects of baking method and temperature on surface browning and acrylamide concentration of cookies were investigated. Cookies were baked in natural and forced convection and steam-assisted hybrid ovens at 165, 180, and 195 °C and at different times. For all oven types, the acrlyamide concentration and surface color of cookies increased with increasing baking temperature. Significant correlation was observed between acrylamide formation and browning index, BI, which was calculated from Hunter L, a, and b color values, and it showed that the BI may be considered as a reliable indicator of acrylamide concentration in cookies. Acrylamide formation and browning index in cookies were considered as the first-order reaction kinetics and the reaction rate constants, k, were in the range of 0.023 to 0.077 (min(-1) ) and 0.019 to 0.063 (min(-1) ), respectively. The effect of baking temperature on surface color and acrylamide concentration followed the Arrhenius type of equation, with activation energies for acrylamide concentration as 6.87 to 27.84 kJ/mol; for BI value as 19.54 to 35.36 kJ/mol, for all oven types. Steam-assisted baking resulted in lower acrylamide concentration at 165 °C baking temperature and lower surface color for all temperatures. Steam-assisted baking is recommended as a healthy way of cooking providing the reduction of harmful compounds such as acrylamide for bakery goods, at a minimal level, while keeping the physical quality. The kinetics of acrylamide formation and browning of cookies will possibly allow definition of optimum baking temperatures and times at convectional and steam-assisted baking ovens. The kinetic model can be used by developing baking programs that can automatically control especially a new home-scale steam-assisted hybrid oven producing healthy products, for the use of domestic consumers. © 2012 Institute of Food Technologists®

  16. Unusual Slowly Rotating Brown Dwarfs Discovered through Precision Spitzer Photometry

    Science.gov (United States)

    Heinze, Aren; Metchev, S.

    2014-01-01

    Many brown dwarfs exhibit low-amplitude rotationally modulated variability due to photospheric inhomogeneities caused by condensate clouds in their atmospheres. The Spitzer Space Telescope 'Weather on Other Worlds' (WoW) project has monitored 44 brown dwarfs at unprecedented photometric precision from space. We present one of several important new results from WoW: the discovery of brown dwarfs with unexpectedly slow rotation periods. While most brown dwarfs have periods of 2-12 hours, we have identified two with well-constrained periods of 13±1 and >20 hours, respectively, and 2 others that show more tentative evidence of longer than 20-hour periods. By serving as almost non-rotating standards, these objects will allow more accurate calibration of spectroscopic measurements of brown dwarfs' projected rotational velocities. The existence of such slowly-rotating objects also constrains models of brown dwarf formation and angular momentum evolution.

  17. Germinated brown rice and its role in human health.

    Science.gov (United States)

    Wu, Fengfeng; Yang, Na; Touré, Alhassane; Jin, Zhengyu; Xu, Xueming

    2013-01-01

    Brown rice, unmilled or partly milled, contains more nutritional components than ordinary white rice. Despite its elevated content of bioactive components, brown rice is rarely consumed as a staple food for its dark appearance and hard texture. The germination of brown rice can be used to improve its taste and further enhance its nutritional value and health functions. Germinated brown rice is considered healthier than white rice, as it is not only richer in the basic nutritional components such as vitamins, minerals, dietary fibers, and essential amino acids, but also contains more bioactive components, such as ferulic acid, γ-oryzanol, and gamma aminobutyric acid. Moreover, germinated brown rice has been reported to exhibit many physiological effects, including antihyperlipidemia, antihypertension, and the reduction in the risk of some chronic diseases, such as cancer, diabetes, cardiovascular disease, and Alzheimer's disease. Therefore, it is likely that germinated brown rice will become a popular health food.

  18. Transcriptional Control of Brown Fat Determination by PRDM16

    OpenAIRE

    Seale, Patrick; Kajimura, Shingo; Yang, Wenli; Chin, Sherry; Rohas, Lindsay; Uldry, Marc; Tavernier, Geneviève; Langin, Dominique; Spiegelman, Bruce M.

    2007-01-01

    Brown fat cells are specialized to dissipate energy and can counteract obesity; however, the transcriptional basis of their determination is largely unknown. We show here that the zinc-finger protein PRDM16 is highly enriched in brown fat cells compared to white fat cells. When expressed in white fat cell progenitors, PRDM16 activates a robust brown fat phenotype including induction of PGC-1α, UCP1 and type 2 deiodinase expression, and a remarkable increase in uncoupled respiration. Transgeni...

  19. Regulation of glycolysis in brown adipocytes by HIF-1α

    DEFF Research Database (Denmark)

    Basse, Astrid Linde; Isidor, Marie Sophie; Winther, Sally

    2017-01-01

    Brown adipose tissue takes up large amounts of glucose during cold exposure in mice and humans. Here we report an induction of glucose transporter 1 expression and increased expression of several glycolytic enzymes in brown adipose tissue from cold-exposed mice. Accordingly, these genes were also...... with glucose as the only exogenously added fuel. These data suggest that HIF-1α-dependent regulation of glycolysis is necessary for maximum glucose metabolism in brown adipocytes....

  20. Obituary: Beth Brown (1969-2008)

    Science.gov (United States)

    Bregman, Joel

    2011-12-01

    The astronomical community lost one of its most buoyant and caring individuals when Beth Brown died, unexpectedly, at the age of 39 from a pulmonary embolism. Beth Brown was born in Roanoke, Virginia where she developed a deep interest in astronomy, science, and science fiction (Star Trek). After graduating as the valedictorian of William Fleming High School's Class of 1987, she attended Howard University, where she graduated summa cum laude in 1991 with a bachelor's degree in astrophysics. Following a year in the graduate physics program at Howard, she entered the graduate program in the Department of Astronomy at the University of Michigan, the first African-American woman in the program. She received her PhD in 1998, working with X-ray observations of elliptical galaxies from the Röntgen Satellite (ROSAT; Joel Bregman was her advisor). She compiled and analyzed the first large complete sample of such galaxies with ROSAT and her papers in this area made an impact in the field. Following her PhD, Beth Brown held a National Academy of Science & National Research Council Postdoctoral Research Fellowship at NASA's Goddard Space Flight Center. Subsequently, she became a civil servant at the National Space Science Data Center at GSFC, where she was involved in data archival activities as well as education and outreach, a continuing passion in her life. In 2006, Brown became an Astrophysics Fellow at GSFC, during which time she worked as a visiting Assistant Professor at Howard University, where she taught and worked with students and faculty to improve the teaching observatory. At the time of her death, she was eagerly looking forward to a new position at GSFC as the Assistant Director for Science Communications and Higher Education. Beth Brown was a joyous individual who loved to work with people, especially in educating them about our remarkable field. Her warmth and openness was a great aid in making accessible explanations of otherwise daunting astrophysical

  1. Brown Dwarf Like Behaviors of Jupiter

    Science.gov (United States)

    Ghosh, K.

    2007-06-01

    Jupiter is by far the most massive object in our solar system after the Sun having mass of about 10-3 M&odot, M&odot being the mass of the Sun. Its density is significantly lower than that of the inner planets; just 1.3 g cm-3 while the densities of Mercury, Venus, Earth and Mars are respectively 5.4, 5.3, 5.5 and 3.9 g cm-3. Jupiter radiates more energy into space than it receives from the Sun. It is proposed that the interior of Jupiter has excess energy stored since the time of its collapse. The heat is also generated by the Kelvin-Helmholtz mechanism, the slow gravitational compression of the configuration. This heat within Jupiter contributes to the unusual motion in the internal rotation in Jupiter. Motions in the interior of Jupiter contribute in a very special way to the development of the powerful and extensive magnetosphere of Jupiter. These observations indicate that the composition of Jupiter is basically different from that of the inner planets and these properties of Jupiter are significantly similar to the features of rotating brown dwarfs under the consideration of magnetic field which are thought to be objects having mass between stars and planets. The stellar bodies with mass less than the lower mass limit of the main sequence become completely degenerate as a consequence of gravitational contraction and consequently they cannot go through normal stellar evolution. Primarily they were named 'Black Dwarf.' The modern term for these objects is 'Brown Dwarf.' In their young age (<10^8 years) they contract rapidly and the gravitational binding energy released makes them quite luminous, but as they age they cool rapidly and make them harder to detect. Calculations show a significant similarity in this paper between the presently observed configuration of Jupiter with that of the model brown dwarf under the consideration of internal rotation and magnetic field with mass, composition and age same that of Jupiter which leads to to a conclusion that

  2. From a Brown to a Green Economy

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    2013-01-01

    instruments such as taxes and subsidies. In this way, renewable energy sources and green industries become more competitive, thus enhancing the transition from brown to green economy. Not only can these economic incentives accelerate the so-called switch point in time from fossil fuel–based energy sources......One main theme in the Rio+20 Conference was how to facilitate the growth of green industries. How can politicians more specifically promote renewable green industries such as wind turbines or solar energy? How can we get prices right in the market? Prices can be adjusted by the use of economic...

  3. Diterpenes from the Brown Alga Dictyota crenulata

    Directory of Open Access Journals (Sweden)

    Valéria Laneuville Teixeira

    2008-06-01

    Full Text Available The crude extract of the Brazilian brown alga Dictyota crenulata was analyzed by NMR spectroscopy and HRGC-MS techniques. Seven diterpenes were identified: pachydictyol A, dictyodial, 4β-hydroxydictyodial A, 4β-acetoxydictyodial A, isopachydictyol A, dictyol C and dictyotadiol. Xeniane diterpenes have previously been found in D. crenulata from the Pacific Ocean. The results characterize D. crenulata as a species that provides prenylated guaiane (group I and xeniane diterpenes (group III, thus making it a new source of potential antiviral products.

  4. Brown Dwarf Variability: What's Varying and Why?

    Science.gov (United States)

    Marley, Mark Scott

    2014-01-01

    Surveys by ground based telescopes, HST, and Spitzer have revealed that brown dwarfs of most spectral classes exhibit variability. The spectral and temporal signatures of the variability are complex and apparently defy simplistic classification which complicates efforts to model the changes. Important questions include understanding if clearings are forming in an otherwise uniform cloud deck or if thermal perturbations, perhaps associated with breaking gravity waves, are responsible. If clouds are responsible how long does it take for the atmospheric thermal profile to relax from a hot cloudy to a cooler cloudless state? If thermal perturbations are responsible then what atmospheric layers are varying? How do the observed variability timescales compare to atmospheric radiative, chemical, and dynamical timescales? I will address such questions by presenting modeling results for time-varying partly cloudy atmospheres and explore the importance of various atmospheric processes over the relevant timescales for brown dwarfs of a range of effective temperatures. Regardless of the origin of the observed variability, the complexity seen in the atmospheres of the field dwarfs hints at the variability that we may encounter in the next few years in directly imaged young Jupiters. Thus understanding the nature of variability in the field dwarfs, including sensitivity to gravity and metallicity, is of particular importance for exoplanet characterization.

  5. Brown Adipose Tissue Bioenergetics: A New Methodological Approach

    Science.gov (United States)

    Calderon‐Dominguez, María; Alcalá, Martín; Sebastián, David; Zorzano, Antonio; Viana, Marta; Serra, Dolors

    2017-01-01

    The rediscovery of brown adipose tissue (BAT) in humans and its capacity to oxidize fat and dissipate energy as heat has put the spotlight on its potential as a therapeutic target in the treatment of several metabolic conditions including obesity and diabetes. To date the measurement of bioenergetics parameters has required the use of cultured cells or extracted mitochondria with the corresponding loss of information in the tissue context. Herein, we present a method to quantify mitochondrial bioenergetics directly in BAT. Based on XF Seahorse Technology, we assessed the appropriate weight of the explants, the exact concentration of each inhibitor in the reaction, and the specific incubation time to optimize bioenergetics measurements. Our results show that BAT basal oxygen consumption is mostly due to proton leak. In addition, BAT presents higher basal oxygen consumption than white adipose tissue and a positive response to b‐adrenergic stimulation. Considering the whole tissue and not just subcellular populations is a direct approach that provides a realistic view of physiological respiration. In addition, it can be adapted to analyze the effect of potential activators of thermogenesis, or to assess the use of fatty acids or glucose as a source of energy. PMID:28435771

  6. Enzymatic browning and after-cooking darkening of Jerusalem artichoke tubers (Helianthus tuberosus L.)

    DEFF Research Database (Denmark)

    Bach, Vibe; Bennedbæk-Jensen, Sidsel; Clausen, Morten Rahr

    2013-01-01

    enzymatic browning, but Rema and Draga had higher scores than Mari in after-cooking darkening. Jerusalem artichoke tubers had higher contents of total phenolics, phenolic acids and citric acid in the autumn and low contents in the spring, while it was the opposite for malic acid. None of the chemical......Jerusalem artichoke tubers (Helianthus tuberosus L.) undergo enzymatic browning when peeled or cut, and turn grey after boiling, due to after-cooking darkening reactions between iron and phenolic acids. In an attempt to reveal the components responsible for these discolouration reactions, sensory...... evaluation and instrumental colour measurements were related to contents of total phenolics, phenolic acids, organic acids and iron in three varieties of raw and boiled Jerusalem artichoke tubers harvested in the autumn and the spring. No differences were found between varieties in sensory evaluated...

  7. Effects of some hydrocolloids and water activity on nonenzymic browning of concentrated orange juice.

    Science.gov (United States)

    Gögüs, F; Düzdemir, C; Eren, S

    2000-12-01

    5-hydroxymethyl furfural (HMF) accumulation and brown pigment formation (BPF) were studied in the presence and absence of some hydrocolloids in concentrated orange juice. The influence of addition of 1.5% xanthan gum (XG) and 1.5% XG and 0.5% microcrystalline cellulose (MCC) were observed on the nonenzymic browning reactions in concentrated orange juice at 45, 60, and 75 degrees C. The effect of water activity was also observed by replacing the samples into different water activity media (0.11 +/- 0.01, 0.30 +/- 0.01, 0.50 +/- 0.01, 0.75 +/- 0.01, and 0.80 +/- 0.01). It was observed that the samples containing 1.5% XG and 0.5% MCC showed the lowest BPF and HMF accumulation, whereas the browning rate and HMF accumulation in pure orange juice were the highest at all temperatures. Maximum BPF and HMF accumulation were observed in the range of water activity between 0.30 and 0.75. The lowest values were observed at aw 0.80.

  8. File list: Unc.Adp.10.AllAg.Brown_preadipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Adp.10.AllAg.Brown_preadipocytes mm9 Unclassified Adipocyte Brown preadipocytes... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Adp.10.AllAg.Brown_preadipocytes.bed ...

  9. The Therapeutic Potential of Brown Adipocytes in Humans

    Directory of Open Access Journals (Sweden)

    Craig ePorter

    2015-10-01

    Full Text Available Obesity and its metabolic consequences represent a significant clinical problem. From a thermodynamic standpoint, obesity results from a discord in energy intake and expenditure. To date, lifestyle interventions based on reducing energy intake and/or increasing energy expenditure have proved ineffective in the prevention and treatment of obesity, owing to poor long-term adherence to such interventions. Thus, an effective strategy to prevent or correct obesity is currently lacking.As the combustion engines of our cells, mitochondria play a critical role in energy expenditure. At a whole body level, approximately 80% of mitochondrial membrane potential generated by fuel oxidation is used to produce ATP, and the remaining 20% is lost through heat-producing uncoupling reactions. The coupling of mitochondrial respiration to ATP production represents an important component in whole body energy expenditure. Brown adipose tissue (BAT is densely populated with mitochondria containing the inner mitochondrial proton carrier uncoupling protein 1 (UCP. UCP1 uncouples oxidative phosphorylation, meaning that mitochondrial membrane potential is dissipated as heat. The recent re-discovery of BAT depots in adult humans has rekindled scientific interest in the manipulation of mitochondrial uncoupling reactions as a means to increase metabolic rate, thereby counteracting obesity and its associated metabolic phenotype. In this article, we discuss the evidence for the role BAT plays in metabolic rate and glucose and lipid metabolism in humans, and the potential for UCP1 recruitment in the white adipose tissue of humans. While the future holds much promise for a therapeutic role of UCP1 expressing adipocytes in human energy metabolism, particularly in the context of obesity, tissue specific strategies that activate or recruit UCP1 in human adipocytes represent an obligatory translation step for this early promise to be realized.

  10. Possible consequences of the sucrose replacement by a fructose-glucose syrup

    Directory of Open Access Journals (Sweden)

    Judit Süli

    2017-01-01

    Full Text Available The fructose-glucose syrup is currently used instead of sucrose in bakery products for economic and technological reasons. The authors investigated the extent to which this change affects the formation of non-enzymatic browning products (Advanced Glycation End - AGE-Products and melanoidins. Formation of these products in model systems - mixtures of various sugars (sucrose, fructose, glucose - concentration 6% with glycine (concentration 0.7% or/and lysine (concentration 0.3%, heat-treated 60 - 100 °C for 15, 30, 45 and 60 min, was studied. The formation of AGE products and melanoidins was determined on the basis of absorption at 294 nm (AGE-products and 420 nm (melanoidins, respectively. The results pointed out notable difference in the AGE-products and also melanoidins formation for a variety of sugars. The reactivity of sucrose was low even at 100 °C/60 min. Fructose and glucose originated a significantly increasing of the non-enzymatic browning products formation. The reactivity of fructose was in the caramelisation and also in Maillard reactions the highest in any combination of composition. Lysine is the most reactive amino acid which takes part in Maillard reactions even if it is bound to protein. The non-enzymatic browning reactions result in the formation of non-digestible cross-linked proteins. Lysine is also the limiting essential amino acid of most cereals. Due to the lysine properties, reduction in protein quality is the most important nutritional effect of Maillard reactions in food. The sucrose replacement by fructose-glucose syrup in bakery products leads to more extensive non-enzymatic browning reactions, i.e. caramelisation and also Maillard reactions, while changes are in the Maillard reaction more pronounced.

  11. A Role for 2-Methyl Pyrrole in the Browning of 4-Oxopentanal and Limonene Secondary Organic Aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Aiona, Paige K. [Department; Lee, Hyun Ji [Department; Lin, Peng [Department; Heller, Forrest [Environmental; Laskin, Alexander [Department; Laskin, Julia [Department; Nizkorodov, Sergey A. [Department

    2017-09-15

    Brown Carbon” (BrC) is a type of organic particulate matter that absorbs visible and near ultraviolet radiation. Reactions of carbonyls in secondary organic aerosol (SOA) produced from limonene with ammonia (NH3) or ammonium sulfate (AS) are known to produce BrC with a distinctive absorption band at 500 nm. Although the general mechanism for this process has been proposed in previous studies, the specific molecular structures of the light-absorbing species remain unclear. This study examined the browning processes occurring in aqueous solutions of AS and 4-oxopentanal (4-OPA), which has a 1,4-dicarbonyl structural motif present in many limonene SOA compounds. The reaction of 4-OPA with AS in a bulk aqueous solution produces a 2-methyl pyrrole (2-MP) intermediate, which is not a strong light absorber by itself, but can react further with carbonyl compounds leading to the eventual formation of BrC chromophores. The direct involvement of 2-MP in the browning process was demonstrated by reacting 2-MP with 4-OPA and with limonene SOA, both of which produced BrC chromophores with distinctive absorption bands at visible wavelengths. The formation of BrC in reaction of 4-OPA with AS and ammonium nitrate (AN) was found to be accelerated by evaporation of the solution suggesting an important role of the dehydration processes in BrC formation from 1,4- dicarbonyls. 4-OPA was also found to produce BrC in aqueous reactions with a broad spectrum of amino acids and amines. The results suggest that 4-OPA may be the smallest atmospherically relevant compound capable of browning by the same mechanism as limonene SOA.

  12. Exploring the microbiota of the red-brown defect in smear-ripened cheese by 454-pyrosequencing and its prevention using different cleaning systems.

    Science.gov (United States)

    Guzzon, Raffaele; Carafa, Ilaria; Tuohy, Kieran; Cervantes, Gonzalo; Vernetti, Luca; Barmaz, Andrea; Larcher, Roberto; Franciosi, Elena

    2017-04-01

    Red-brown pigmentation can occasionally form in smeared-ripened cheese such as Fontina during the ripening process. This reaction is due to over-development of the typical microbiota present on the rind. Previous studies have demonstrated the relationship between red-brown pigmentation and the traditional utilization of wooden shelves during cheese ripening. The first part of the paper focuses on the characterisation of yeast and bacterial microbiota: plate counts and 454-pyrosequencing were performed in spoiled (n = 6) and non-spoiled cheeses (n = 6) and on the wooden shelves used during ripening. The second part shows different systems tested for cleaning the wooden shelves and avoiding the development of the red-brown defect in cheese: washing with hot water and ozone treatment. Actinobacteria, dominated on the wooden shelves, suggesting to be responsible for the red-brown pigmentation; they were also found in traces in the defected cheese samples. Galactomyces and Debaryomyces were the main species characterizing the yeast population, with Debaryomyces being the most dominant species on the shelves used during ripening of the red-brown defective cheese. Hot water treatment reduced the microbial contamination of shelves, whereas only the ozone treatment ensured complete elimination of both yeast and bacteria, resulting in the cheese rind not having the red-brown defect. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Reduction of Exudates (Browning) in Sugarcane Micro Propagation ...

    African Journals Online (AJOL)

    ... of this variety, ascorbic acid and citric acid was added as constituent of the media using MS and stock at different concentrations. The browning was reduced drastically at the addition of 0.1g/litre ascorbic acid and 0.15g/litre citric acid. Keywords: reduction, exudates browning, micro propagation, sugarcane. Nig J. Biotech.

  14. Approaches to diagnosis and detection of cassava brown streak ...

    African Journals Online (AJOL)

    Cassava brown streak disease (CBSD) has been a problem in the East African coastal cassava growing areas for more than 70 years. The disease is caused by successful infection with Cassava Brown Streak Virus (CBSV) (Family, Potyviridae: Genus, Ipomovirus). Diagnosis of CBSD has for long been primarily leaf ...

  15. Physicochemical properties of germinated brown rice ( Oryza sativa L.)

    African Journals Online (AJOL)

    Physicochemical properties of white rice (WR), brown rice (BR) and germinated brown rice (GBR) starches from a mixed variety of MR219 and MR220, commonly consumed Malaysian varieties, were compared in this study. The granular size of the starch particles, measured using scanning electron microscope (SEM), ...

  16. The "brown" environmental agenda and the constitutional duties of ...

    African Journals Online (AJOL)

    This note explores the interrelationship between ecologically sustainable development (the green environmental agenda) and pro-poor urban development and environmental health (the brown environmental agenda) in relation to local government in South Africa. The meaning and relevance of the brown agenda versus ...

  17. Sorghum Brown Midrib Mutants, Tools to Improve Biomass for Biofuels

    Science.gov (United States)

    To improve sorghum for cellulosic bioenergy uses, brown midrib mutants are being investigated for their ability to increase the conversion efficiency of biomass. brown midrib 6 and 12 (bmr6 and 12) mutants affect monolignol biosynthesis resulting in reduced lignin content and altered lignin composi...

  18. Witnessing "Brown": Pursuit of an Equity Agenda in American Education

    Science.gov (United States)

    Smith, Anne; Kozleski, Elizabeth B.

    2005-01-01

    The 50th anniversary of the "Brown v. Board of Education" decision provides a critical opportunity to reflect on "Brown's" importance, impact, and the lessons it provides on achieving racial desegregation and its relationship to the progressive inclusion of students with disabilities into public schools across the United…

  19. The Troublesome Legacy of "Brown v. Board of Education"

    Science.gov (United States)

    López, Gerardo R.; Burciaga, Rebeca

    2014-01-01

    Purpose: This article reflects on the 60th anniversary of the "Brown v. Board of Education" Supreme Court decision while discussing the significant lessons learned from this and subsequent court decisions. Argument: In this article, we posit that a fundamentally different conversation surrounding the legacy of Brown is needed if we are…

  20. Sperm storage potential and daily sperm production of brown male ...

    African Journals Online (AJOL)

    Sperm storage potential and daily sperm production of brown male Japanese quails for three different physiological age groups. ... positively correlated (r=0.91 P<0.01). This study revealed that the brown male Japanese quail has its peak reproduction potential at puberty. Keywords: Quail sperm storage, sperm production ...

  1. Reduction of Exudates (Browning) in Sugarcane Micro Propagation

    African Journals Online (AJOL)

    DELL USER

    scientists have therefore resulted to the use of biotechnology to mass produce this plant. One of the problems encountered is browning as a result of exudates from wounds in the course of ex- plant preparation. This paper discussed how the browning can be controlled and rapidly produce shoot from explants in vitro.

  2. Phytase activity in brown rice during steeping and sprouting

    NARCIS (Netherlands)

    Ou, K.; Cheng, Y.; Xing, Y.; Lin, L.; Nout, M.J.R.; Liang, J.

    2011-01-01

    Phytase in brown rice will be activated and accumulated during seed germination. Changes of phytase activity in brown rice during two stages of germination (steeping and sprouting) affected by process conditions were studied. It was shown that steeping led to significant decrease of phytase activity

  3. Differential gene expression in white and brown preadipocytes

    NARCIS (Netherlands)

    Boeuf, S.; Klaus, S.; Klingenspor, M.; Schneider, T.; Franssen-Hal, van N.L.W.; Keijer, J.

    2001-01-01

    White (WAT) and brown (BAT) adipose tissue are tissues of energy storage and energy dissipation, respectively. Experimental evidence suggests that brown and white preadipocytes are differentially determined, but so far not much is known about the genetic control of this determination process. The

  4. Nonenzyme browning and its effect on protein nutrition.

    Science.gov (United States)

    Dworschák, E

    1980-01-01

    The nonenzyme browning involves the thermal decomposition of sugars, the caramelization, the decomposition of oxi-acids, the so called "Maillard reaction" between amino acids and carbohydrates, the reaction between oxidized fats and proteins, and those alterations which take place by the alkaline treatment of proteins. The Maillard reaction is of secondary importance in the case of foodstuffs and fodders with low carbohydrate contents (meats, meat meal, fish meal). By the heat treatment, the sulphur-containing amino acids of proteins (cystine, methionine) are damaged primarily because of oxidation, but the decrease in the amount of threonine, serine, tryptophan, and lysine is observable too. According to the formation of enzyme resistant cross-links, the in vitro and in vivo digestibility of protein decreases after the heat threatment and the communication with oxidized fats. Besides the amino acids mentioned, the possibility of enzymatic break-off of leucine and isoleucine is reduced too. In the course of the heating of proteins the occurance of racemization has to be considered too (formation of alloisoleucine). The basic mechanism of the reaction between sugars and simple amino acids is already essentially explained: amino-acids break off after the formation glycosilamines and Amadori products but they are linked irreversibly to some, partly unsaturated decomposition products of sugars, types of 6 and 3 carbon atoms. The decrease in the biological usability of amino acids starts already with the Amadori products. The reactivity of the single amino acids depends on the number of carbon atoms, on the basicity, and on the polarity of the amino acid molecule. The especially highly reactive amino acids of proteins are (1) the essential lysine (because of its 6-HN2 group), (2) other types of basic amino acids, and (3) trypotphan (because of the lability of the indole ring), methionine, cystine and threonine. In the Maillard reaction of tryptophan the --NH--group of

  5. The effects of tolaasin, the toxin produced by Pseudomonas tolaasii on tyrosinase activities and the induction of browning in Agaricus bisporus fruiting bodies

    NARCIS (Netherlands)

    Soler Rivas, C.; Arpin, N.; Olivier, J.M.; Wichers, H.J.

    1999-01-01

    Infection of Agaricus bisporus with Pseudomonas tolaasii or treatment with a tolaasin containing preparation resulted in the activation of tyrosinase and the development of a brown discolouration of the fruitbody. In order to investigate whether tolaasin is responsible for these reactions, mushrooms

  6. Methane, carbon monoxide, and ammonia in brown dwarfs and self-luminous giant planets

    Energy Technology Data Exchange (ETDEWEB)

    Zahnle, Kevin J.; Marley, Mark S., E-mail: Kevin.J.Zahnle@NASA.gov, E-mail: Mark.S.Marley@NASA.gov [NASA Ames Research Center, MS-245-3, Moffett Field, CA 94035 (United States)

    2014-12-10

    We address disequilibrium abundances of some simple molecules in the atmospheres of solar composition brown dwarfs and self-luminous extrasolar giant planets using a kinetics-based one-dimensional atmospheric chemistry model. Our approach is to use the full kinetics model to survey the parameter space with effective temperatures between 500 K and 1100 K. In all of these worlds, equilibrium chemistry favors CH{sub 4} over CO in the parts of the atmosphere that can be seen from Earth, but in most disequilibrium favors CO. The small surface gravity of a planet strongly discriminates against CH{sub 4} when compared to an otherwise comparable brown dwarf. If vertical mixing is like Jupiter's, the transition from methane to CO occurs at 500 K in a planet. Sluggish vertical mixing can raise this to 600 K, but clouds or more vigorous vertical mixing could lower this to 400 K. The comparable thresholds in brown dwarfs are 1100 ± 100 K. Ammonia is also sensitive to gravity, but, unlike CH{sub 4}/CO, the NH{sub 3}/N{sub 2} ratio is insensitive to mixing, which makes NH{sub 3} a potential proxy for gravity. HCN may become interesting in high-gravity brown dwarfs with very strong vertical mixing. Detailed analysis of the CO-CH{sub 4} reaction network reveals that the bottleneck to CO hydrogenation goes through methanol, in partial agreement with previous work. Simple, easy to use quenching relations are derived by fitting to the complete chemistry of the full ensemble of models. These relations are valid for determining CO, CH{sub 4}, NH{sub 3}, HCN, and CO{sub 2} abundances in the range of self-luminous worlds we have studied, but may not apply if atmospheres are strongly heated at high altitudes by processes not considered here (e.g., wave breaking).

  7. Restricting glycolysis impairs brown adipocyte glucose and oxygen consumption

    DEFF Research Database (Denmark)

    Winther, Sally; Isidor, Marie S; Basse, Astrid L

    2018-01-01

    )-stimulated respiration was fueled mainly by fatty acids, with a significant contribution from glucose oxidation. Knockdown of glucose transporters in brown adipocytes not only impaired ISO-stimulated glycolytic flux but also oxygen consumption. Diminishing glycolytic flux by knockdown of the first and final enzyme......During thermogenic activation, brown adipocytes take up large amounts of glucose. In addition, cold stimulation leads to an upregulation of glycolytic enzymes. Here we have investigated the importance of glycolysis for brown adipocyte glucose consumption and thermogenesis. Using si......RNA-mediated knockdown in mature adipocytes, we explored the effect of glucose transporters and glycolytic enzymes on brown adipocyte functions such as consumption of glucose and oxygen. Basal oxygen consumption in brown adipocytes was equally dependent on glucose and fatty acid oxidation, whereas isoproterenol (ISO...

  8. Investigation of metal ions sorption of brown peat moss powder

    Science.gov (United States)

    Kelus, Nadezhda; Blokhina, Elena; Novikov, Dmitry; Novikova, Yaroslavna; Chuchalin, Vladimir

    2017-11-01

    For regularities research of sorptive extraction of heavy metal ions by cellulose and its derivates from aquatic solution of electrolytes it is necessary to find possible mechanism of sorption process and to choice a model describing this process. The present article investigates the regularities of aliovalent metals sorption on brown peat moss powder. The results show that sorption isotherm of Al3+ ions is described by Freundlich isotherm and sorption isotherms of Na+ i Ni2+ are described by Langmuir isotherm. To identify the mechanisms of brown peat moss powder sorption the IR-spectra of the initial brown peat moss powder samples and brown peat moss powder samples after Ni (II) sorption were studied. Metal ion binding mechanisms by brown peat moss powder points to ion exchange, physical adsorption, and complex formation with hydroxyl and carboxyl groups.

  9. Alleviation of Oxidative Stress by Using Olive Pomace in Crossbred (Brown Swiss X Baladi) Calves Under Hot Environmental Conditions

    International Nuclear Information System (INIS)

    Abdalla, E.B.; Khalil, F.K.; El - Masry, K.A.; Teama, F.E.; Emara, S.S.

    2015-01-01

    Ten female crossbred (Brown Swiss X Baladi) calves , 8 – 10 months old with average live body weight of 112 kg at the be ginning of experimental period were used to investigate the effect of olive pomace (OP) supplementation which contains phenolic compounds on oxidant and antioxidant agents and some blood constituents, and its relation with growth performance in heat stressed calves. The animals were maintained under hot summer environmental conditions, where, ambient temperature and relative humidity average d 37.48°C ± 0.32 and 64.58 % ± 0.77 , (equivalent to THI 91) during day, and 28.38 °C ± 0.22 and 78.23 % ± 0.69 , (equivalent to THI 80) during night, respectively. The animals were divided into two equal groups (5 calves each). The first group control (received 0 % OP of the concentrate mixture, while the second group) treated received 15 % OP of the concentrate mixture, for two months. Body weight o f calves was recorded twice at the beginning and at the end of experimental period, and daily gain was calculated for each animal. Blood samples were taken from each animal at the end of experimental period to determine antioxidant and oxidant indices, some blood constituents and T 3 concentration. Our results showed that supplementation of OP significantly increased antioxidant status including catalase enzyme activity, total antioxidant capacity, uric acid as a non-enzymatic antioxidant and copper as a specific antioxidant protecting macromolecules. More over, OP significantly reduced serum malondialdehyde as a lipid peroxidation marker, iron concentration which act as a pro-oxidant, lipids profile including total cholesterol, low density lipoprotein (LDL – cholesterol), very low density lipoprotein (VLDL – cholesterol), triglycerides and phospholipids. Also, OP caused a significant decrease in serum creatinine and urea- N concentrations as well as AST activity. However, OP significantly elevated T3 level, and improved feed efficiency and daily

  10. Browning and graying: novel transcriptional regulators of brown and beige fat tissues and aging

    Directory of Open Access Journals (Sweden)

    Elisabetta eMueller

    2016-03-01

    Full Text Available Obesity represents a major risk factor for the development of a number of metabolic disorders, including cardiovascular disease and type 2 diabetes. Since the discovery that brown and beige fat cells exist in adult humans and contribute to energy expenditure, increasing interest has been devoted to the understanding of the molecular switches turning on calorie utilization. It has been reported that the ability of thermogenic tissues to burn energy declines during aging, possibly contributing to the development of metabolic dysfunction late in life. This review will focus on the recently identified transcriptional modulators of brown and beige cells and will discuss the potential impact of some of these thermogenic factors on age-associated metabolic disorders.

  11. Arsenic, organic foods, and brown rice syrup.

    Science.gov (United States)

    Jackson, Brian P; Taylor, Vivien F; Karagas, Margaret R; Punshon, Tracy; Cottingham, Kathryn L

    2012-05-01

    Rice can be a major source of inorganic arsenic (Asi) for many sub-populations. Rice products are also used as ingredients in prepared foods, some of which may not be obviously rice based. Organic brown rice syrup (OBRS) is used as a sweetener in organic food products as an alternative to high-fructose corn syrup. We hypothesized that OBRS introduces As into these products. We determined the concentration and speciation of As in commercially available brown rice syrups and in products containing OBRS, including toddler formula, cereal/energy bars, and high-energy foods used by endurance athletes. We used inductively coupled plasma mass spectrometry (ICP-MS) and ion chromatography coupled to ICP-MS to determine total As (Astotal) concentrations and As speciation in products purchased via the Internet or in stores in the Hanover, New Hampshire, area. We found that OBRS can contain high concentrations of Asi and dimethyl-arsenate (DMA). An "organic" toddler milk formula containing OBRS as the primary ingredient had Astotal concentrations up to six times the U.S. Environmental Protection Agency safe drinking water limit. Cereal bars and high-energy foods containing OBRS also had higher As concentrations than equivalent products that did not contain OBRS. Asi was the main As species in most food products tested in this study. There are currently no U.S. regulations applicable to As in food, but our findings suggest that the OBRS products we evaluated may introduce significant concentrations of Asi into an individual's diet. Thus, we conclude that there is an urgent need for regulatory limits on As in food.

  12. Toxins not neutralized by brown snake antivenom

    International Nuclear Information System (INIS)

    Judge, Roopwant K.; Henry, Peter J.; Mirtschin, Peter; Jelinek, George; Wilce, Jacqueline A.

    2006-01-01

    The Australian snakes of the genus Pseudonaja (dugite, gwardar and common brown) account for the majority of snake bite related deaths in Australia. Without antivenom treatment, the risk of mortality is significant. There is an accumulating body of evidence to suggest that the efficacy of the antivenom is limited. The current study investigates the protein constituents recognized by the antivenom using 2-DE, immuno-blot techniques and rat tracheal organ bath assays. The 2-DE profiles for all three snake venoms were similar, with major species visualized at 78-132 kDa, 32-45 kDa and 6-15 kDa. Proteins characterized by LC-MS/MS revealed a coagulant toxin (∼42 kDa) and coagulant peptide (∼6 kDa), as well as two PLA 2 (∼14 kDa). Peptides isolated from ∼78 kDa and 15-32 kDa protein components showed no similarity to known protein sequences. Protein recognition by the antivenom occurred predominantly for the higher molecular weight components with little recognition of 6-32 kDa MW species. The ability of antivenom to neutralize venom activity was also investigated using rat tracheal organ bath assays. The venoms of Pseudonaja affinis affinis and Pseudonaja nuchalis incited a sustained, significant contraction of the trachea. These contractions were attributed to PLA 2 enzymatic activity as pre-treatment with the PLA 2 inhibitor 4-BPB attenuated the venom-induced contractions. The venom of Pseudonaja textilis incited tracheal contractility through a non-PLA 2 enzymatic activity. Neither activity was attenuated by the antivenom treatment. These results represent the first proteomic investigation of the venoms from the snakes of the genus Pseudonaja, revealing a possible limitation of the brown snake antivenom in binding to the low MW protein components

  13. Drivers of hibernation in the brown bear.

    Science.gov (United States)

    Evans, A L; Singh, N J; Friebe, A; Arnemo, J M; Laske, T G; Fröbert, O; Swenson, J E; Blanc, S

    2016-01-01

    Hibernation has been a key area of research for several decades, essentially in small mammals in the laboratory, yet we know very little about what triggers or ends it in the wild. Do climatic factors, an internal biological clock, or physiological processes dominate? Using state-of-the-art tracking and monitoring technology on fourteen free-ranging brown bears over three winters, we recorded movement, heart rate (HR), heart rate variability (HRV), body temperature (Tb), physical activity, ambient temperature (TA), and snow depth to identify the drivers of the start and end of hibernation. We used behavioral change point analyses to estimate the start and end of hibernation and convergent cross mapping to identify the causal interactions between the ecological and physiological variables over time. To our knowledge, we have built the first chronology of both ecological and physiological events from before the start to the end of hibernation in the field. Activity, HR, and Tb started to drop slowly several weeks before den entry. Bears entered the den when snow arrived and when ambient temperature reached 0 °C. HRV, taken as a proxy of sympathetic nervous system activity, dropped dramatically once the bear entered the den. This indirectly suggests that denning is tightly coupled to metabolic suppression. During arousal, the unexpected early rise in Tb (two months before den exit) was driven by TA, but was independent of HRV. The difference between Tb and TA decreased gradually suggesting that bears were not thermoconforming. HRV increased only three weeks before exit, indicating that late activation of the sympathetic nervous system likely finalized restoration of euthermic metabolism. Interestingly, it was not until TA reached the presumed lower critical temperature, likely indicating that the bears were seeking thermoneutrality, that they exited the den. We conclude that brown bear hibernation was initiated primarily by environmental cues, but terminated by

  14. Novel Browning Agents, Mechanisms, and Therapeutic Potentials of Brown Adipose Tissue

    Directory of Open Access Journals (Sweden)

    Umesh D. Wankhade

    2016-01-01

    Full Text Available Nonshivering thermogenesis is the process of biological heat production in mammals and is primarily mediated by brown adipose tissue (BAT. Through ubiquitous expression of uncoupling protein 1 (Ucp1 on the mitochondrial inner membrane, BAT displays uncoupling of fuel combustion and ATP production in order to dissipate energy as heat. Because of its crucial role in regulating energy homeostasis, ongoing exploration of BAT has emphasized its therapeutic potential in addressing the global epidemics of obesity and diabetes. The recent appreciation that adult humans possess functional BAT strengthens this prospect. Furthermore, it has been identified that there are both classical brown adipocytes residing in dedicated BAT depots and “beige” adipocytes residing in white adipose tissue depots that can acquire BAT-like characteristics in response to environmental cues. This review aims to provide a brief overview of BAT research and summarize recent findings concerning the physiological, cellular, and developmental characteristics of brown adipocytes. In addition, some key genetic, molecular, and pharmacologic targets of BAT/Beige cells that have been reported to have therapeutic potential to combat obesity will be discussed.

  15. Reaction mechanisms

    International Nuclear Information System (INIS)

    Nguyen Trong Anh

    1988-01-01

    The 1988 progress report of the Reaction Mechanisms laboratory (Polytechnic School, France), is presented. The research topics are: the valence bond methods, the radical chemistry, the modelling of the transition states by applying geometric constraints, the long range interactions (ion - molecule) in gaseous phase, the reaction sites in gaseous phase and the mass spectroscopy applications. The points of convergence between the investigations of the mass spectroscopy and the theoretical chemistry teams, as well as the purposes guiding the research programs, are discussed. The published papers, the conferences, the congress communications and the thesis, are also reported [fr

  16. Sulforaphane induces adipocyte browning and promotes glucose and lipid utilization.

    Science.gov (United States)

    Zhang, Hui Q; Chen, Shi Y; Wang, An S; Yao, An J; Fu, Jian F; Zhao, Jin S; Chen, Fen; Zou, Zu Q; Zhang, Xiao H; Shan, Yu J; Bao, Yong P

    2016-10-01

    Obesity is closely related to the imbalance of white adipose tissue storing excess calories, and brown adipose tissue dissipating energy to produce heat in mammals. Recent studies revealed that acquisition of brown characteristics by white adipocytes, termed "browning," may positively contribute to cellular bioenergetics and metabolism homeostasis. The goal was to investigate the putative effects of natural antioxidant sulforaphane (1-isothiocyanate-4-methyl-sulfonyl butane; SFN) on browning of white adipocytes. 3T3-L1 mature white adipocytes were treated with SFN for 48 h, and then the mitochondrial content, function, and energy utilization were assessed. SFN was found to induce 3T3-L1 adipocytes browning based on the increased mitochondrial content and activity of respiratory chain enzymes, whereas the mechanism involved the upregulation of nuclear factor E2-related factor 2/sirtuin1/peroxisome proliferator activated receptor gamma coactivator 1 alpha signaling. SFN enhanced uncoupling protein 1 expression, a marker for brown adipocyte, leading to the decrease in cellular ATP. SFN also enhanced glucose uptake and oxidative utilization, lipolysis, and fatty acid oxidation in 3T3-L1 adipocytes. SFN-induced browning of white adipocytes enhanced the utilization of cellular fuel, and application of SFN is a promising strategy to combat obesity and obesity-related metabolic disorder. © 2016 The Authors. Molecular Nutrition & Food Research Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. EVIDENCE FOR ACCRETION IN A NEARBY, YOUNG BROWN DWARF

    International Nuclear Information System (INIS)

    Reiners, Ansgar

    2009-01-01

    We report on the discovery of the young, nearby, brown dwarf 2MASS J0041353-562112. The object has a spectral type of M7.5; it shows Li absorption and signatures of accretion, which implies that it still has a disk and suggests an age below 10 Myr. The space motion vector and position on the sky indicate that the brown dwarf is probably a member of the ∼20 Myr old Tuc-Hor association, or that it may be an ejected member of the ∼12 Myr old β Pic association; both would imply that 2MASS J0041353-562112 may in fact be older than 10 Myr. No accreting star or brown dwarf was previously known in these associations. Assuming an age of 10 Myr, the brown dwarf has a mass of about 30 M Jup and is located at 35 pc distance. The newly discovered object is the closest accreting brown dwarf known. Its membership to an association older than 10 Myr implies that either disks in brown dwarfs can survive as long as in more massive stars, perhaps even longer, or that star formation in Tuc-Hor or β Pic occurred more recently than previously thought. The history and evolution of this object can provide new fundamental insight into the formation process of stars, brown dwarfs, and planets.

  18. Capture reactions

    NARCIS (Netherlands)

    Endt, P.M.

    1956-01-01

    Capture reactions will be considered here from the viewpoint of the nuclear spectroscopist. Especially important to him are the capture of neutrons, protons, and alpha particles, which may proceed through narrow resonances, offering a well defined initial state for the subsequent deexcitation

  19. Allergic reactions

    Science.gov (United States)

    ... that don't bother most people (such as venom from bee stings and certain foods, medicines, and pollens) can ... person. If the allergic reaction is from a bee sting, scrape the ... more venom. If the person has emergency allergy medicine on ...

  20. cycloaddition reactions

    Indian Academy of Sciences (India)

    Unknown

    ... has shown very severe limitations in predicting the regioselectivity. In comparison,. DFT-based descriptors are better suited to model the regioselectivity of cycloaddition reactions. Acknowledgements. GG thanks the Council of Scientific and Industrial. Research for a fellowship. References. 1. Winkler J D 1996 Chem. Rev.

  1. Browning boreal forests of western North America

    Science.gov (United States)

    Verbyla, David

    2011-12-01

    The GIMMS NDVI dataset has been widely used to document a 'browning trend' in North American boreal forests (Goetz et al 2005, Bunn et al 2007, Beck and Goetz 2011). However, there has been speculation (Alcaraz-Segura et al 2010) that this trend may be an artifact due to processing algorithms rather than an actual decline in vegetation activity. This conclusion was based primarily on the fact that GIMMS NDVI did not capture NDVI recovery within most burned areas in boreal Canada, while another dataset consistently showed post-fire increasing NDVI. I believe that the results of Alcaraz-Segura et al (2010) were due simply to different pixel sizes of the two datasets (64 km2 versus 1 km2 pixels). Similar results have been obtained from tundra areas greening in Alaska, with the results simply due to these pixel size differences (Stow et al 2007). Furthermore, recent studies have documented boreal browning trends based on NDVI from other sensors. Beck and Goetz (2011) have shown the boreal browning trend derived from a different sensor (MODIS) to be very similar to the boreal browning trend derived from the GIMMS NDVI dataset for the circumpolar boreal region. Parent and Verbyla (2010) found similar declining NDVI patterns based on NDVI from Landsat sensors and GIMMS NDVI in boreal Alaska. Zhang et al (2008) found a similar 'browning trend' in boreal North America based on a production efficiency model using an integrated AVHRR and MODIS dataset. The declining NDVI trend in areas of boreal North America is consistent with tree-ring studies (D'Arrigo et al 2004, McGuire et al 2010, Beck et al 2011). The decline in tree growth may be due to temperature-induced drought stress (Barber et al 2000) caused by higher evaporative demands in a warming climate (Lloyd and Fastie 2002). In a circumpolar boreal study, Lloyd and Bunn (2007) found that a negative relationship between temperature and tree-ring growth occurred more frequently in warmer parts of species' ranges

  2. Movement and mortality of stocked brown trout in a stream

    DEFF Research Database (Denmark)

    Aarestrup, Kim; Jepsen, Niels; Koed, Anders

    2005-01-01

    The movement and mortality of stocked brown trout Salmo trutta were investigated using radio telemetry. Four brown trout left the study area whereas the remaining fish were stationary. After 5 weeks, 13 out of 50 tagged brown trout were still alive in the stream. Surviving fish had a significantly...... lower mean movement per day than fish, which later either died or disappeared. This difference in behaviour was most pronounced 2 to 8 days after release. Predation by the otter Lutra lutra was probably the main cause of the observed mortality. (c) 2005 The Fisheries Society of the British Isles...

  3. Pre-germinated Parboiled Brown Rice Drying Using Fluidization Technique

    OpenAIRE

    Nattapol Poomsa-ad; Lamul Wiset

    2012-01-01

    Pre-germinated parboiled brown rice or Khao hang (in Thai) is paddy which undergoing the processes of soaking, steaming, drying and dehusking to obtain the edible form for consumption. The objectives of this research were to study the kinetic of pre-germinated parboiled brown rice drying using fluidization technique and to study the properties of pre-germinated parboiled brown rice after drying. The dryings were performed at the different temperatures of 110, 120 and 130 oC at the bed depth o...

  4. Discovery of Nearest Known Brown Dwarf

    Science.gov (United States)

    2003-01-01

    Bright Southern Star Epsilon Indi Has Cool, Substellar Companion [1] Summary A team of European astronomers [2] has discovered a Brown Dwarf object (a 'failed' star) less than 12 light-years from the Sun. It is the nearest yet known. Now designated Epsilon Indi B, it is a companion to a well-known bright star in the southern sky, Epsilon Indi (now "Epsilon Indi A"), previously thought to be single. The binary system is one of the twenty nearest stellar systems to the Sun. The brown dwarf was discovered from the comparatively rapid motion across the sky which it shares with its brighter companion : the pair move a full lunar diameter in less than 400 years. It was first identified using digitised archival photographic plates from the SuperCOSMOS Sky Surveys (SSS) and confirmed using data from the Two Micron All Sky Survey (2MASS). Follow-up observations with the near-infrared sensitive SOFI instrument on the ESO 3.5-m New Technology Telescope (NTT) at the La Silla Observatory confirmed its nature and has allowed measurements of its physical properties. Epsilon Indi B has a mass just 45 times that of Jupiter, the largest planet in the Solar System, and a surface temperature of only 1000 °C. It belongs to the so-called 'T dwarf' category of objects which straddle the domain between stars and giant planets. Epsilon Indi B is the nearest and brightest T dwarf known. Future studies of the new object promise to provide astronomers with important new clues as to the formation and evolution of these exotic celestial bodies, at the same time yielding interesting insights into the border zone between planets and stars. TINY MOVING NEEDLES IN GIANT HAYSTACKS ESO PR Photo 03a/03 ESO PR Photo 03a/03 [Preview - JPEG: 400 x 605 pix - 92k [Normal - JPEG: 1200 x 1815 pix - 1.0M] Caption: PR Photo 03a/03 shows Epsilon Indi A (the bright star at far right) and its newly discovered brown dwarf companion Epsilon Indi B (circled). The upper image comes from one of the SuperCOSMOS Sky

  5. alpha-Dicarbonyl compounds formed by nonenzymatic browning during the dry heating of caseinate and lactose.

    Science.gov (United States)

    Ge Pan, Geoffrey; Oliver, Christine M; Melton, Laurence D

    2006-09-06

    A method using high-performance liquid chromatography with UV and electrospray ionization mass spectrometry detection was developed for monitoring the alpha-dicarbonyl compound profiles generated from nonenzymatic browning using o-phenylenediamine (OPD) as a trapping agent. The alpha-dicarbonyl compounds were generated by the "dry" reaction of sodium caseinate and lactose heated at various relative humidities (RHs). The proportions of alpha-dicarbonyls formed were different for samples heated at low, intermediate, and high RHs. This study shows that relatively large amounts of 3-deoxypentosulose and galactosyl 2-pentosulose are produced under high RHs, while galactosyl hexosulose and 1,4-dideoxyhexosulose are elevated under low RH conditions. Both caramelization and Maillard reaction pathways contributed to the generation of alpha-dicarbonyls.

  6. Modificações do método gravimétrico não enzimático para determinar fibra alimentar solúvel e insolúvel em frutos Modifications in the gravimetric non enzymatic method for determination of soluble and insoluble dietary fiber in fruits

    Directory of Open Access Journals (Sweden)

    Nonete Barbosa Guerra

    2004-03-01

    Full Text Available OBJETIVOS: Modificações do tratamento da amostra e da seqüência operacional do método gravimétrico não enzimático foram realizadas, com vistas a simplificá-lo e permitir a quantificação das frações solúvel e insolúvel da fibra alimentar total. MÉTODOS: A influência da liofilização foi inicialmente avaliada em amostras de goiaba e, posteriormente, em acerola, manga, pinha, sapoti e uva. As modificações inerentes à seqüência metodológica foram testadas nos referidos frutos e em abacaxi, caju, maracujá e morango. RESULTADOS: As médias de fibra alimentar total obtidas para goiaba liofilizada e não liofilizada: 10,47%±1,15 e 10,53 %±0,88, respectivamente, demonstram: boa reprodutibilidade do método e inexistência de diferenças significativas entre os tratamentos aplicados à goiaba e demais frutos. Diferentemente do constatado na determinação da Fibra Alimentar Insolúvel, cujo percentual variou de 99,6% para o caju a 54,0% para a acerola, os dados gerados para a fibra alimentar solúvel foram desconsiderados, dada a dispersibilidade apresentada. CONCLUSÃO: Estes resultados evidenciam que as amostras prescindem da liofilização e que a quantificação da Fibra Alimentar Solúvel requer ajustes na etapa de precipitação.OBJETIVES: Modifications in the treatment of samples and operational sequence of the gravimetric non enzymatic method were carried out in order to simplify it and allow the quantification of soluble and insoluble quantities of the total dietary fiber. METHODS: Lyophilization influence was first evaluated in guava samples and afterward in samples of acerola, mango, sugar apples, sapodilla and grapes. The mentioned fruits and also pineapple, cashew, passion fruit and strawberry were tested for the modifications intrinsic in the methodological sequence. RESULTS: The average total dietary fiber for guava, both lyophilized and non-lyophilized, were: 10.50% ±0.97 and 10.53% ±0.88, respectively

  7. Ectocarpus: a model organism for the brown algae.

    Science.gov (United States)

    Coelho, Susana M; Scornet, Delphine; Rousvoal, Sylvie; Peters, Nick T; Dartevelle, Laurence; Peters, Akira F; Cock, J Mark

    2012-02-01

    The brown algae are an interesting group of organisms from several points of view. They are the dominant organisms in many coastal ecosystems, where they often form large, underwater forests. They also have an unusual evolutionary history, being members of the stramenopiles, which are very distantly related to well-studied animal and green plant models. As a consequence of this history, brown algae have evolved many novel features, for example in terms of their cell biology and metabolic pathways. They are also one of only a small number of eukaryotic groups to have independently evolved complex multicellularity. Despite these interesting features, the brown algae have remained a relatively poorly studied group. This situation has started to change over the last few years, however, with the emergence of the filamentous brown alga Ectocarpus as a model system that is amenable to the genomic and genetic approaches that have proved to be so powerful in more classical model organisms such as Drosophila and Arabidopsis.

  8. Data for Brown et al MEA Developmental Neurotoxicity Screening Manuscript

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data are the individual parameter and well-level data that were support the conclusions in Brown et al. Note: the parameters CVtime and CVnetwork were not...

  9. NOAA Ship Ronald Brown Underway Meteorological Data, Quality Controlled

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Ronald Brown Underway Meteorological Data (delayed ~10 days for quality control) are from the Shipboard Automated Meteorological and Oceanographic System...

  10. NOAA Ship Ronald Brown Underway Meteorological Data, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Ship Ronald Brown Underway Meteorological Data (Near Real Time, updated daily) are from the Shipboard Automated Meteorological and Oceanographic System (SAMOS)...

  11. Technical and economic aspects of brown coal gasification and liquefaction

    International Nuclear Information System (INIS)

    Speich, P.

    1980-01-01

    A number of gasification and liquefaction processes for Rhenish brown coal are investigated along with the technical and economic aspects of coal beneficiation. The status of coal beneficiation and the major R + D activities are reviewed. (orig.) [de

  12. Brown Trout Distribution, Pacific Northwest (updated March, 2006)

    Data.gov (United States)

    Pacific States Marine Fisheries Commission — This dataset is a record of fish distribution and activity for BROWN TROUT contained in the StreamNet database. This feature class was created based on linear event...

  13. Genetic backgrounds determine brown remodeling of white fat in rodents

    Directory of Open Access Journals (Sweden)

    Giulia Ferrannini

    2016-10-01

    Conclusion: Rodent genetic background determines the brown remodeling of different white fat depots. This study provides new insights into the role of genetic variation in fat remodeling in susceptibility to metabolic diseases.

  14. Rüütel, Halonen ja Brown? / Eve Heinla

    Index Scriptorium Estoniae

    Heinla, Eve, 1966-

    2006-01-01

    James Browni kontserdil 27. juulil Tallinna laulukaare all loodetakse kaasa tõmmata ka poliitikud. Ameerika soulmuusik James Brown esitas president Arnold Rüütlile kutse laulda koos temaga duetti. Lisa: Rüütlil siiani Annaniga laulmata

  15. Brown and Beige Fat: Molecular Parts of a Thermogenic Machine.

    Science.gov (United States)

    Cohen, Paul; Spiegelman, Bruce M

    2015-07-01

    The epidemic of obesity and type 2 diabetes has increased interest in pathways that affect energy balance in mammalian systems. Brown fat, in all of its dimensions, can increase energy expenditure through the dissipation of chemical energy in the form of heat, using mitochondrial uncoupling and perhaps other pathways. We discuss here some of the thermodynamic and cellular aspects of recent progress in brown fat research. This includes studies of developmental lineages of UCP1(+) adipocytes, including the discovery of beige fat cells, a new thermogenic cell type. We also discuss the physiology and transcriptional control of brown and beige cells in rodents and the state of current knowledge about human brown fat. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  16. The Suppressive Activity of Fucofuroeckol-A Derived from Brown Algal Ecklonia stolonifera Okamura on UVB-Induced Mast Cell Degranulation

    Directory of Open Access Journals (Sweden)

    Thanh Sang Vo

    2018-01-01

    Full Text Available UV light, especially UVB, is known as a trigger of allergic reaction, leading to mast cell degranulation and histamine release. In this study, phlorotannin Fucofuroeckol-A (F-A derived from brown algal Ecklonia stolonifera Okamura was evaluated for its protective capability against UVB-induced allergic reaction in RBL-2H3 mast cells. It was revealed that F-A significantly suppress mast cell degranulation via decreasing histamine release as well as intracellular Ca2+ elevation at the concentration of 50 μM. Moreover, the inhibitory effect of F-A on IL-1β and TNF-α productions was also evidenced. Notably, the protective activity of F-A against mast cell degranulation was found due to scavenging ROS production. Accordingly, F-A from brown algal E. stolonifera was suggested to be promising candidate for its protective capability against UVB-induced allergic reaction.

  17. Brown Grease to Biodiesel Demonstration Project Report

    Energy Technology Data Exchange (ETDEWEB)

    San Francisco Public Utilities Commission; URS Corporation; Biofuels, Blackgold; Carollo Engineers

    2013-01-30

    program by other municipal agencies (as applicable). In order to accomplish the goals of the project, the following steps were performed: 1. Operation of a demonstration facility designed to receive 10,000 to 12,000 gallons of raw Trap Waste each day from private Trap Waste hauling companies. The demonstration facility was designed and built by Pacific Biodiesel Technologies (PBTech). The demonstration facility would also recover 300 gallons of Brown Grease per day from the raw Trap Waste. The recovered Brown Grease was expected to contain no more than 2% Moisture, Insolubles, and Unsaponifiables (MIU) combined. 2. Co-digestion of the side streams (generated during the recovery of 300 gallons of Brown Grease from the raw Trap Waste) with wastewater sludge in the WWTP's anaerobic digesters. The effects of the side streams on anaerobic digestion were quantified by comparison with baseline data. 3. Production of 240 gallons per day of ASTM D6751-S15 grade Biodiesel fuel via a Biodiesel conversion demonstration facility, with the use of recovered Brown Grease as a feedstock. The demonstration facility was designed and built by Blackgold Biofuels (BGB). Side streams from this process were also co-digested with wastewater sludge. Bench-scale anaerobic digestion testing was conducted on side streams from both demonstration facilities to determine potential toxicity and/or changes in biogas production in the WWTP anaerobic digester. While there is a lot of theoretical data available on the lab-scale production of Biodiesel from grease Trap Waste, this full-scale demonstration project was one of the first of its kind in the United States. The project's environmental impacts were expected to include: Reduction of greenhouse gas emissions by prevention of the release of methane at landfills. Although the combustion product of Biodiesel and Methane gas produced in the Anaerobic digester, Carbon Dioxide, is also a greenhouse gas; it is 20 times weaker for the same amount

  18. Activation of brown adipose tissue in hypothyroidism.

    Science.gov (United States)

    Lapa, Constantin; Maya, Yoshifumi; Wagner, Martin; Arias-Loza, Paula; Werner, Rudolf A; Herrmann, Ken; Higuchi, Takahiro

    2015-01-01

    Brown adipose tissue (BAT) attracts growing interest as a potential therapeutic target for obesity and diabetes. Hyperthyroidism is well-known to increase BAT activity, but the role of hypothyroidism is controversial. We aimed to investigate the association between different thyroid hormone (TH) states and BAT activity. FDG-PET studies were retrospectively evaluated in thyroid cancer patients after total thyroidectomy both at euthyroidism during TH replacement or at hypothyroidism after TH cessation. Serum TH levels were compared between patients with active BAT and control patients with non-active BAT matched for age, gender, and body mass index. Additionally, animal experiments with controls (n = 5) and hypothyroid rats (n = 5) were performed. Out of 124 patients, 6 patients with active BAT were identified. These patients showed significantly higher thyroid-stimulating hormone (TSH) levels than matched controls (P hypothyroid animals showed BAT activation at room temperature (24 °C), whereas controls did not (P hypothyroidism, which might be the result of a feedback mechanism to maintain body temperature in a state of reduced basal thermogenesis. Future research needs to explore the underlying mechanistic and biological implications.

  19. JVLA Observations of Young Brown Dwarfs

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez, Luis F.; Zapata, Luis A.; Palau, Aina, E-mail: l.rodriguez@crya.unam.mx, E-mail: l.zapata@crya.unam.mx, E-mail: a.palau@crya.unam.mx [Instituto de Radioastronomía y Astrofísica, UNAM, Apdo. Postal 3-72 (Xangari), 58089 Morelia, Michoacán, México (Mexico)

    2017-05-01

    We present sensitive 3.0 cm JVLA radio continuum observations of six regions of low-mass star formation that include twelve young brown dwarfs (BDs) and four young BD candidates. We detect a total of 49 compact radio sources in the fields observed, of which 24 have no reported counterparts and are considered new detections. Twelve of the radio sources show variability in timescales of weeks to months, suggesting gyrosynchrotron emission produced in active magnetospheres. Only one of the target BDs, FU Tau A, was detected. However, we detected radio emission associated with two of the BD candidates, WL 20S and CHLT 2. The radio flux densities of the sources associated with these BD candidates are more than an order of magnitude larger than expected for a BD and suggest a revision of their classification. In contrast, FU Tau A falls on the well-known correlation between radio luminosity and bolometric luminosity, suggesting that the emission comes from a thermal jet and that this BD seems to be forming as a scaled-down version of low-mass stars.

  20. Extraction of organic compounds from brown coal

    Directory of Open Access Journals (Sweden)

    Slavomír Hredzák

    2005-11-01

    Full Text Available The paper presents the study on the extraction of organic compounds (low-molecular weight - diterpenes, high-molecular weight - fullerenes and humic acids from Handlová brown coal and pyrolytic soot. It was confirmed that the coal extract with a diterpene content - 16 β (H kaurene was obtained by the supercritical fluid extraction (using CO2 and modificator - tetrahydrofurane/acetone, 8:2 w/w at T = 90 oC and p = 30 MPa. The occurrence of fullerenes in the toluene extract of solid carbon product has confirmed by the MALDI - TOF - MS and UV-VIS spectroscopy. In the extraction process of GACL (Grinding Aqueous Caustic Leaching at the concentration of 0.1 % NaOH, the content of humic acids (HK in the physically untreated and pretreated sample increased by 6.09 and 4.57 times, respectively. In the case of higher leaching agent concentration (2 % NaOH, the content of HK in the physically untreated and pretreated sample increased by 8,67 and 8,21 times, respectively.

  1. Monoclonal Antibodies Directed to Fucoidan Preparations from Brown Algae

    OpenAIRE

    Torode, Thomas A.; Marcus, Susan E.; Jam, Murielle; Tonon, Thierry; Blackburn, Richard S.; Herv?, C?cile; Knox, J. Paul

    2015-01-01

    International audience; Cell walls of the brown algae contain a diverse range of polysaccharides with useful bioactivities. The precise structures of the sulfated fucan/fucoidan group of polysaccharides and their roles in generating cell wall architectures and cell properties are not known in detail. Four rat monoclonal antibodies, BAM1 to BAM4, directed to sulfated fucan preparations, have been generated and used to dissect the heterogeneity of brown algal cell wall polysaccharides. BAM1 and...

  2. Thermogenic activation represses autophagy in brown adipose tissue.

    Science.gov (United States)

    Cairó, M; Villarroya, J; Cereijo, R; Campderrós, L; Giralt, M; Villarroya, F

    2016-10-01

    Brown adipose tissue (BAT) thermogenesis is an adaptive process, essential for energy expenditure and involved in the control of obesity. Obesity is associated with abnormally increased autophagy in white adipose tissue. Autophagy has been proposed as relevant for brown-vs-white adipocyte differentiation; however, its role in the response of BAT to thermogenic activation is unknown. The effects of thermogenic activation on autophagy in BAT were analyzed in vivo by exposing mice to 24 h cold condition. The effects of norepinephrine (NE), cAMP and modulators of lysosomal activity were determined in differentiated brown adipocytes in the primary culture. Transcript expression was quantified by real-time PCR, and specific proteins were determined by immunoblot. Transmission electron microscopy, as well as confocal microscopy analysis after incubation with specific antibodies or reagents coupled to fluorescent emission, were performed in BAT and cultured brown adipocytes, respectively. Autophagy is repressed in association with cold-induced thermogenic activation of BAT in mice. This effect was mimicked by NE action in brown adipocytes, acting mainly through a cAMP-dependent protein kinase A pathway. Inhibition of autophagy in brown adipocytes leads to an increase in UCP1 protein and uncoupled respiration, suggesting a repressing role for autophagy in relation to the activity of BAT thermogenic machinery. Under basal conditions, brown adipocytes show signs of active lipophagy, which is suppressed by a cAMP-mediated thermogenic stimulus. Our results show a noradrenergic-mediated inverse relationship between autophagy and thermogenic activity in BAT and point toward autophagy repression as a component of brown adipocyte adaptive mechanisms to activate thermogenesis.

  3. New library buildings. Part VI: Sciences Library, Brown University.

    Science.gov (United States)

    Carson, J R; Bobick, J E

    1976-04-01

    Brown was one of the first universities in the nation to combine its science collections into a single library in the interest of aiding interdisciplinary teaching and research. This paper discusses the evolution of the Sciences Library and its resources, the development of the medical education program, and the physical aspects of the new library building. A fifteen-story tower, housing the collections of the physical, biological, and medical sciences, symbolizes the interdisciplinary approach to teaching and research at Brown University.

  4. Vacancy clusters, dislocations and brown colouration in diamond

    OpenAIRE

    Bangert, U.; Barnes, R.; Gass, M. H.; Bleloch, A. L.; Godfrey, I. S.

    2009-01-01

    Following on from the idea that clusters of vacancies are the origin of the featureless absorption and brown colouration in natural diamond, dislocations are shown to exhibit sub-bandgap absorption also. The vacancy cluster idea has arisen from theoretical predictions of π-bonded chains reconstructing the cluster surfaces and has been confirmed by energy loss studies. In contrast, bandgap states at dislocations are observed in brown and colourless diamonds alike, giving rise to weak absorptio...

  5. Management of brown bears (Ursus arctos) in Europe.

    OpenAIRE

    Klenzendorf, Sybille A.

    1997-01-01

    Management of Brown Bears (Ursus arctos) in Europe. Sybille A. Klenzendorf (Abstract) Successful conservation of brown bears (Ursus arctos) in Europe is associated with public acceptance of damages caused by bears. Recent increases in sheep depredation and beehive damage in central Austria resulted in the deaths of two bears there. Since bear numbers are low in most European populations, alternatives to the elimination of problem bears associated with dam...

  6. Browning of Subcutaneous White Adipose Tissue in Humans

    OpenAIRE

    Sidossis, Labros S.; Porter, Craig; Saraf, Manish K.; Børsheim, Elisabet; Radhakrishnan, Ravi S.; Chao, Tony; Ali, Arham; Chondronikola, Maria; Mlcak, Ronald; Finnerty, Celeste C.; Hawkins, Hal K.; Toliver-Kinsky, Tracy; Herndon, David N.

    2015-01-01

    Since the presence of brown adipose tissue (BAT) was confirmed in adult humans, BAT has become a therapeutic target for obesity and insulin resistance. We examined whether human subcutaneous white adipose tissue (sWAT) can adopt a BAT-like phenotype using a clinical model of prolonged and severe adrenergic stress. sWAT samples were collected from severely burned and healthy individuals. A subset of burn victims were prospectively followed during their acute hospitalization. Browning of sWAT w...

  7. Brown coal - on the way to industrial-scale upgrading

    International Nuclear Information System (INIS)

    Speich, P.

    1981-01-01

    The main fields of development of Rheinische Braunkohlenwerke AG (Rheinbraun) in the field of brown coal upgrading are reported, i.e. production of synthesis gas, SNG, and liquid products. The Rheinbraun research programme involves the processes of high-temperature-Winkler gasification, hydrogasification, hydroliquefaction, tube stills, and methanation plants. In the long run, nuclear power will be indispensable for base load power supply so that brown coal can be upgraded instead of being used directly for electric power generation. (HS) [de

  8. Brown algae as a model for plant organogenesis.

    Science.gov (United States)

    Bogaert, Kenny A; Arun, Alok; Coelho, Susana M; De Clerck, Olivier

    2013-01-01

    Brown algae are an extremely interesting, but surprisingly poorly explored, group of organisms. They are one of only five eukaryotic lineages to have independently evolved complex multicellularity, which they express through a wide variety of morphologies ranging from uniseriate branched filaments to complex parenchymatous thalli with multiple cell types. Despite their very distinct evolutionary history, brown algae and land plants share a striking amount of developmental features. This has led to an interest in several aspects of brown algal development, including embryogenesis, polarity, cell cycle, asymmetric cell division and a putative role for plant hormone signalling. This review describes how investigations using brown algal models have helped to increase our understanding of the processes controlling early embryo development, in particular polarization, axis formation and asymmetric cell division. Additionally, the diversity of life cycles in the brown lineage and the emergence of Ectocarpus as a powerful model organism, are affording interesting insights on the molecular mechanisms underlying haploid-diploid life cycles. The use of these and other emerging brown algal models will undoubtedly add to our knowledge on the mechanisms that regulate development in multicellular photosynthetic organisms.

  9. In vitro effectiveness of Brazilian brown propolis against Enterococcus faecalis

    Directory of Open Access Journals (Sweden)

    Hévelin Couto PIMENTA

    2015-01-01

    Full Text Available The aim of this study was to evaluate the in vitro antimicrobial activity of Brazilian brown propolis as an intracanal medication against Enterococcus faecalis. Thirty dentin discs prepared from intact freshly extracted bovine maxillary central incisors were infected with E. faecalis for 21 days. The specimens were distributed into six groups according to the medicament used as follows: G1- calcium hydroxide paste; G2- Carbowax 400 (control group; G3- 20% brown propolis paste; G4- 40% brown propolis paste; G5- 20% brown propolis paste + calcium hydroxide paste; and G6- 40% brown propolis paste + calcium hydroxide paste. The experimental pastes were placed into the canal lumen and left for 14 days. After each period, irrigation was performed with sterile saline to remove the medicament, and the canals were dried with sterile paper points. The dentin chips were removed from the canals with sequential sterile round burs at low speed and were immediately collected in separate test tubes containing BHI broth. The tubes were incubated at 37°C, and microbial growth was analyzed by spectrophotometry after 15 days. All the experimental medications significantly reduced the number of viable bacteria. The G4 and G5 pastes were more effective than the G1 paste, with 35.8%, 41%, and 21.3% antibacterial activity, respectively. Brazilian brown propolis shows antibacterial capacity against E. faecalis.

  10. Influence of surround proximity on induction of brown and darkness.

    Science.gov (United States)

    Buck, Steven L; Shelton, Andrew; Stoehr, Brooke; Hadyanto, Vina; Tang, Miaolu; Morimoto, Takuma; DeLawyer, Tanner

    2016-03-01

    A bright white surround makes a yellow long-wavelength target look both browner and darker. We explored the parallel between these two types of induction by examining their dependence on the proximity of the bright surround to the target at two different time scales with 27 ms and 1 s stimulus durations. We assessed (a) brown induction by adjustment of target luminance to perceptual brown and yellow boundaries and (b) darkness induction by a successive matching procedure. We found that brown induction is a quick process that is robust even for 27 ms stimuli. For darkness induction, there was a strong, spatially localized surround proximity effect for the 27 ms stimuli and much weaker proximity effect for the 1 s stimuli. For brown induction, proximity effects were generally weaker but still showed relatively stronger localized proximity effects for 27 ms stimuli than for 1 s stimuli. For these stimuli, darkness induction predicts the relative pattern but not the magnitudes of brown induction. Both brown and darkness inductions show the operation of quick, spatially localized processes that are apparently superseded by other processes for extended stimulus presentations.

  11. Platelet function in brown bear (Ursus arctos compared to man

    Directory of Open Access Journals (Sweden)

    Särndahl Eva

    2010-06-01

    Full Text Available Abstract Background Information on hemostasis and platelet function in brown bear (Ursus arctos is of importance for understanding the physiological, protective changes during hibernation. Objective The study objective was to document platelet activity values in brown bears shortly after leaving the den and compare them to platelet function in healthy humans. Methods Blood was drawn from immobilized wild brown bears 7-10 days after leaving the den in mid April. Blood samples from healthy human adults before and after clopidogrel and acetylsalicylic acid administration served as control. We analyzed blood samples by standard blood testing and platelet aggregation was quantified after stimulation with various agonists using multiple electrode aggregometry within 3 hours of sampling. Results Blood samples were collected from 6 bears (3 females between 1 and 16 years old and from 10 healthy humans. Results of adenosine diphosphate, aspirin, and thrombin receptor activating peptide tests in bears were all half or less of those in humans. Platelet and white blood cell counts did not differ between species but brown bears had more and smaller red blood cells compared with humans. Conclusion Using three different tests, we conclude that platelet function is lower in brown bears compared to humans. Our findings represent the first descriptive study on platelet function in brown bears and may contribute to explain how bears can endure denning without obvious thrombus building. However, the possibility that our findings reflect test-dependent and not true biological variations in platelet reactivity needs further studies.

  12. Eggshell color in brown-egg laying hens - a review.

    Science.gov (United States)

    Samiullah, S; Roberts, J R; Chousalkar, K

    2015-10-01

    The major pigment in eggshells of brown-egg laying hens is protoporphyrin IX, but traces of biliverdin and its zinc chelates are also present. The pigment appears to be synthesized in the shell gland. The protoporphyrin IX synthetic pathway is well defined, but precisely where and how it is synthesized in the shell gland of the brown-egg laying hen is still ambiguous. The pigment is deposited onto all shell layers including the shell membranes, but most of it is concentrated in the outermost layer of the calcareous shell and in the cuticle. Recently, the genes that are involved in pigment synthesis have been identified, but the genetic control of synthesis and deposition of brown pigment in the commercial laying hen is not fully understood. The brown coloration of the shell is an important shell quality parameter and has a positive influence on consumer preference. The extent of pigment deposition is influenced by the housing system, hen age, hen strain, diet, stressors, and certain diseases such as infectious bronchitis. In this article, the physiological and biochemical characteristics of the brown pigment in commercial brown-egg layers are reviewed in relation to its various functions in the poultry industry. © 2015 Poultry Science Association Inc.

  13. Effect of browned and unbrowned corn products intrinsically labeled with 65Zn on absorption of 65Zn in humans

    International Nuclear Information System (INIS)

    Lykken, G.I.; Mahalko, J.; Johnson, P.E.; Milne, D.; Sandstead, H.H.; Garcia, W.J.; Dintzis, F.R.; Inglett, G.E.

    1986-01-01

    Experimental browned and unbrowned corn products were formulated and processed from unenriched, degermed yellow corngrits. The browned product (cornflakes) contained more insoluble dietary fiber and bound more zinc (in vitro) than the unbrowned product (corngrits). During processing some of the cornflakes and corngrits were combined with a small amount of yellow corn endospermhull intrinsically labeled with 65 Zn. The intrinsically labeled corn products were fed, in a crossover design, as components of two breakfasts to six normal, unconfined volunteers. Each volunteer absorbed more 65 Zn from the corngrits than from the cornflakes. The reduced 65 Zn absorption from cornflakes was attributed to heating and toasting reaction products, possibly Maillard, which bound zinc and consequently made the zinc less available for absorption

  14. Loss of ADAMTS5 enhances brown adipose tissue mass and promotes browning of white adipose tissue via CREB signaling

    Directory of Open Access Journals (Sweden)

    Dries Bauters

    2017-07-01

    Conclusions: These data indicate that ADAMTS5 plays a functional role in development of BAT and browning of WAT. Hence, selective targeting of ADAMTS5 could provide a novel therapeutic strategy for treatment/prevention of obesity and metabolic diseases.

  15. Searching for chemical signatures of brown dwarf formation

    Science.gov (United States)

    Maldonado, J.; Villaver, E.

    2017-06-01

    Context. Recent studies have shown that close-in brown dwarfs in the mass range 35-55 MJup are almost depleted as companions to stars, suggesting that objects with masses above and below this gap might have different formation mechanisms. Aims: We aim to test whether stars harbouring massive brown dwarfs and stars with low-mass brown dwarfs show any chemical peculiarity that could be related to different formation processes. Methods: Our methodology is based on the analysis of high-resolution échelle spectra (R 57 000) from 2-3 m class telescopes. We determine the fundamental stellar parameters, as well as individual abundances of C, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, and Zn for a large sample of stars known to have a substellar companion in the brown dwarf regime. The sample is divided into stars hosting massive and low-mass brown dwarfs. Following previous works, a threshold of 42.5 MJup was considered. The metallicity and abundance trends of the two subsamples are compared and set in the context of current models of planetary and brown dwarf formation. Results: Our results confirm that stars with brown dwarf companions do not follow the well-established gas-giant planet metallicity correlation seen in main-sequence planet hosts. Stars harbouring massive brown dwarfs show similar metallicity and abundance distribution as stars without known planets or with low-mass planets. We find a tendency of stars harbouring less-massive brown dwarfs of having slightly higher metallicity, [XFe/Fe] values, and abundances of Sc II, Mn I, and Ni I than the stars having the massive brown dwarfs. The data suggest, as previously reported, that massive and low-mass brown dwarfs might present differences in period and eccentricity. Conclusions: We find evidence of a non-metallicity dependent mechanism for the formation of massive brown dwarfs. Our results agree with a scenario in which massive brown dwarfs are formed as stars. At high metallicities, the core

  16. Effects of White Rice, Brown Rice and Germinated Brown Rice on Antioxidant Status of Type 2 Diabetic Rats

    OpenAIRE

    Imam, Mustapha Umar; Musa, Siti Nor Asma; Azmi, Nur Hanisah; Ismail, Maznah

    2012-01-01

    Oxidative stress is implicated in the pathogenesis of diabetic complications, and can be increased by diet like white rice (WR). Though brown rice (BR) and germinated brown rice (GBR) have high antioxidant potentials as a result of their bioactive compounds, reports of their effects on oxidative stress-related conditions such as type 2 diabetes are lacking. We hypothesized therefore that if BR and GBR were to improve antioxidant status, they would be better for rice consuming populations inst...

  17. Spallation reactions

    International Nuclear Information System (INIS)

    Cugon, J.

    1996-01-01

    Spallation reactions dominate the interactions of hadrons with nuclei in the GeV range (from ∼ 0.1 to ∼ 10 GeV). They correspond to a sometimes important ejection of light particles leaving most of the time a residue of mass commensurate with the target mass. The main features of the experimental data are briefly reviewed. The most successful theoretical model, namely the intranuclear cascade + evaporation model, is presented. Its physical content, results and possible improvements are critically discussed. Alternative approaches are shortly reviewed. (author)

  18. 37 NEW T-TYPE BROWN DWARFS IN THE CANADA-FRANCE BROWN DWARFS SURVEY

    International Nuclear Information System (INIS)

    Albert, Loic; Artigau, Etienne; Delorme, Philippe; Reyle, Celine; Forveille, Thierry; Delfosse, Xavier; Willott, Chris J.

    2011-01-01

    The Canada-France Brown Dwarfs Survey is an i'- and z'-band survey realized with MegaCam at the Canada-France-Hawaii Telescope that covers a surface area of 780 deg 2 . Image analysis is now completed while J-band follow-up campaigns are ∼90% done. The survey identified about 70 T dwarf candidates, of which 43 now have near-infrared spectra obtained with NIRI and GNIRS at Gemini and ISAAC at the Very Large Telescope. Six of these were previously published and we present here the 37 new discoveries, all T dwarfs. They range from T0 to T8.5 with four being of type T7 or later. Both newly identified T8 dwarfs are possibly high log (g) massive brown dwarfs of thin disk age. One T4.5 dwarf shows signs of sub-metallicity. We present proper motions and near-infrared photometry, and discuss about the most peculiar/interesting objects in some details.

  19. Brown colour in natural diamond and interaction between the brown related and other colour-inducing defects

    International Nuclear Information System (INIS)

    Fisher, D; Sibley, S J; Kelly, C J

    2009-01-01

    Absorption spectroscopy results on a range of type II diamonds are presented which enable the electronic states associated with them to be mapped out. High pressure, high temperature treatment of brown type IIa diamonds has enabled an activation energy for the removal of the brown colour of 8.0 ± 0.3 eV to be determined and this is consistent with expectations associated with the currently accepted vacancy cluster model for the defect. Theoretical calculations suggest that this defect will generate partially filled gap states about 1 eV above the valence band. Data on the photochromic behaviour of bands producing pink colour and their relation to brown colour are presented; these suggest that the pink bands are produced from two independent transitions with ground states close to each other just below the middle of the band gap. Compensation of neutral boron by charge transfer from states associated with brown colour is demonstrated via the correlated increase in neutral boron and decrease in brown colour on high pressure, high temperature treatment to remove the defects causing the brown colour.

  20. Nuclear reactions

    International Nuclear Information System (INIS)

    Corner, J.; Richardson, K.; Fenton, N.

    1990-01-01

    Nuclear reactions' marks a new development in the study of television as an agency of public policy debate. During the Eighties, nuclear energy became a major international issue. The disasters at Three-mile Island and Chernobyl created a global anxiety about its risks and a new sensitivity to it among politicians and journalists. This book is a case-study into documentary depictions of nuclear energy in television and video programmes and into the interpretations and responses of viewers drawn from many different occupational groupings. How are the complex and specialist arguments about benefit, risk and proof conveyed through the different conventions of commentary, interview and film sequence? What symbolic associations does the visual language of television bring to portrayals of the issue? And how do viewers make sense of various and conflicting accounts, connecting what they see and hear on the screen with their pre-existing knowledge, experience and 'civic' expectations. The authors examine some of the contrasting forms and themes which have been used by programme makers to explain and persuade, and then give a sustained analysis of the nature and sources of viewers' own accounts. 'Nuclear Reactions' inquires into the public meanings surrounding energy and the environment, spelling out in its conclusion some of the implications for future media treatments of this issue. It is also a key contribution to the international literature on 'television knowledge' and the processes of active viewing. (author)

  1. Central control of brown adipose tissue thermogenesis

    Directory of Open Access Journals (Sweden)

    Shaun F. Morrison

    2012-01-01

    Full Text Available Thermogenesis, the production of heat energy, is an essential component of the homeostatic repertoire to maintain body temperature during the challenge of low environmental temperature and plays a key role in elevating body temperature during the febrile response to infection. Mitochondrial oxidation in brown adipose tissue (BAT is a significant source of neurally-regulated metabolic heat production in many species from mouse to man. BAT thermogenesis is regulated by neural networks in the central nervous system which responds to feedforward afferent signals from cutaneous and core body thermoreceptors and to feedback signals from brain thermosensitive neurons to activate BAT sympathetic nerve activity. This review summarizes the research leading to a model of the feedforward reflex pathway through which environmental cold stimulates BAT thermogenesis and includes the influence on this thermoregulatory network of the pyrogenic mediator, prostaglandin E2, to increase body temperature during fever. The cold thermal afferent circuit from cutaneous thermal receptors, through second-order thermosensory neurons in the dorsal horn of the spinal cord ascends to activate neurons in the lateral parabrachial nucleus which drive GABAergic interneurons in the preoptic area to inhibit warm-sensitive, inhibitory output neurons of the preoptic area. The resulting disinhibition of BAT thermogenesis-promoting neurons in the dorsomedial hypothalamus activates BAT sympathetic premotor neurons in the rostral ventromedial medulla, including the rostral raphe pallidus, which provide excitatory, and possibly disinhibitory, inputs to spinal sympathetic circuits to drive BAT thermogenesis. Other recently recognized central sites influencing BAT thermogenesis and energy expenditure are also described.

  2. Hunting promotes sexual conflict in brown bears.

    Science.gov (United States)

    Gosselin, Jacinthe; Leclerc, Martin; Zedrosser, Andreas; Steyaert, Sam M J G; Swenson, Jon E; Pelletier, Fanie

    2017-01-01

    The removal of individuals through hunting can destabilize social structure, potentially affecting population dynamics. Although previous studies have shown that hunting can indirectly reduce juvenile survival through increased sexually selected infanticide (SSI), very little is known about the spatiotemporal effects of male hunting on juvenile survival. Using detailed individual monitoring of a hunted population of brown bears (Ursus arctos) in Sweden (1991-2011), we assessed the spatiotemporal effect of male removal on cub survival. We modelled cub survival before, during and after the mating season. We used three proxies to evaluate spatial and temporal variation in male turnover; distance and timing of the closest male killed and number of males that died around a female's home range centre. Male removal decreased cub survival only during the mating season, as expected in seasonal breeders with SSI. Cub survival increased with distance to the closest male killed within the previous 1·5 years, and it was lower when the closest male killed was removed 1·5 instead of 0·5 year earlier. We did not detect an effect of the number of males killed. Our results support the hypothesis that social restructuring due to hunting can reduce recruitment and suggest that the distribution of the male deaths might be more important than the overall number of males that die. As the removal of individuals through hunting is typically not homogenously distributed across the landscape, spatial heterogeneity in hunting pressure may cause source-sink dynamics, with lower recruitment in areas of high human-induced mortality. © 2016 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

  3. Introgressive hybridization: brown bears as vectors for polar bear alleles.

    Science.gov (United States)

    Hailer, Frank

    2015-03-01

    The dynamics and consequences of introgression can inform about numerous evolutionary processes. Biologists have therefore long been interested in hybridization. One challenge, however, lies in the identification of nonadmixed genotypes that can serve as a baseline for accurate quantification of admixture. In this issue of Molecular Ecology, Cahill et al. (2015) analyse a genomic data set of 28 polar bears, eight brown bears and one American black bear. Polar bear alleles are found to be introgressed into brown bears not only near a previously identified admixture zone on the Alaskan Admiralty, Baranof and Chichagof (ABC) Islands, but also far into the North American mainland. Elegantly contrasting admixture levels at autosomal and X chromosomal markers, Cahill and colleagues infer that male-biased dispersal has spread these introgressed alleles away from the Late Pleistocene contact zone. Compared to a previous study on the ABC Island population in which an Alaskan brown bear served as a putatively admixture-free reference, Cahill et al. (2015) utilize a newly sequenced Swedish brown bear as admixture baseline. This approach reveals that brown bears have been impacted by introgression from polar bears to a larger extent (up to 8.8% of their genome), than previously known, including the bear that had previously served as admixture baseline. No evidence for introgression of brown bear into polar bear is found, which the authors argue could be a consequence of selection. Besides adding new exciting pieces to the puzzle of polar/brown bear evolutionary history, the study by Cahill and colleagues highlights that wildlife genomics is moving from analysing single genomes towards a landscape genomics approach. © 2015 John Wiley & Sons Ltd.

  4. Phylogeny and biogeography of South Chinese brown frogs (Ranidae, Anura).

    Science.gov (United States)

    Zhou, Yu; Wang, Sirui; Zhu, Hedan; Li, Pipeng; Yang, Baotian; Ma, Jianzhang

    2017-01-01

    Few studies have explored the role of Cenozoic tectonic evolution in shaping the patterns and processes of extant animal distributions in and around East Asia. In this study, we selected South Chinese brown frogs as a model to examine the phylogenetic and biogeographical consequences of Miocene tectonic events within South China and its margins. We used mitochondrial and nuclear molecular data to reconstruct phylogenetic interrelationships among Chinese brown frogs using Bayesian and maximum likelihood analyses. The phylogeny results show that there are four main clades of Chinese brown frogs. Excepting the three commonly known Chinese brown frog species groups, R. maoershanensis forms an independent clade nearest to the R. japonica group. Phylogeny and P-distance analyses confirmed R. maoershanensis as a valid species. Among South Chinese brown frogs, there are four subclades associated with four geographical areas: (I) R. maoershanensis; (II) R. japonica; (III) R. chaochiaoensis; and (IV) other species of the R. longicrus species group. Divergence times, estimated using mitochondrial sequences, place the vicariance events among the four subclades in the middle to late Miocene epoch. Our results suggest that (1) South Chinese brown frogs originated due to a vicariance event separating them from the R. chensinensis species group at the time of the Geological movement (~18 million years ago, Ma) in southern Tibet and the Himalayan region; (2) the separation and speciation of R. maoershanensis from the R. japonica group occurred due to the dry climate at approximately 16 Ma; (3) South Chinese brown frogs migrated from South China to Japan at the time (~10.8 Ma) that the global sea-level fell and the East China Sea Shelf Basin was swamp facies, when a land gallery may have formed across the sea to connect the two areas; and (4) R. chaochiaoensis separated from other species of the R. longicrus species group during the uplift of the Tibetan Plateau at approximately 9

  5. New Brown Dwarf Discs in Upper Scorpius Observed with WISE

    Science.gov (United States)

    Dawson, P.; Scholz, A.; Ray, T. P.; Natta, A.; Marsh, K. A.; Padgett, D.; Ressler, M. E.

    2013-01-01

    We present a census of the disc population for UKIDSS selected brown dwarfs in the 5-10 Myr old Upper Scorpius OB association. For 116 objects originally identified in UKIDSS, the majority of them not studied in previous publications, we obtain photometry from the Wide-Field Infrared Survey Explorer data base. The resulting colour magnitude and colour colour plots clearly show two separate populations of objects, interpreted as brown dwarfs with discs (class II) and without discs (class III). We identify 27 class II brown dwarfs, 14 of them not previously known. This disc fraction (27 out of 116, or 23%) among brown dwarfs was found to be similar to results for K/M stars in Upper Scorpius, suggesting that the lifetimes of discs are independent of the mass of the central object for low-mass stars and brown dwarfs. 5 out of 27 discs (19 per cent) lack excess at 3.4 and 4.6 microns and are potential transition discs (i.e. are in transition from class II to class III). The transition disc fraction is comparable to low-mass stars.We estimate that the time-scale for a typical transition from class II to class III is less than 0.4 Myr for brown dwarfs. These results suggest that the evolution of brown dwarf discs mirrors the behaviour of discs around low-mass stars, with disc lifetimes of the order of 5 10 Myr and a disc clearing time-scale significantly shorter than 1 Myr.

  6. MEASURING TINY MASS ACCRETION RATES ONTO YOUNG BROWN DWARFS

    International Nuclear Information System (INIS)

    Herczeg, Gregory J.; Cruz, Kelle L.; Hillenbrand, Lynne A.

    2009-01-01

    We present low-resolution Keck I/LRIS spectra spanning from 3200 to 9000 A of nine young brown dwarfs and three low-mass stars in the TW Hya Association and in Upper Sco. The optical spectral types of the brown dwarfs range from M5.5 to M8.75, though two have near-IR spectral types of early L dwarfs. We report new accretion rates derived from excess Balmer continuum emission for the low-mass stars TW Hya and Hen 3-600A and the brown dwarfs 2MASS J12073347-3932540, UScoCTIO 128, SSSPM J1102-3431, USco J160606.29-233513.3, DENIS-P J160603.9-205644, and Oph J162225-240515B, and upper limits on accretion for the low-mass star Hen 3-600B and the brown dwarfs UScoCTIO 112, Oph J162225-240515A, and USco J160723.82-221102.0. For the six brown dwarfs in our sample that are faintest at short wavelengths, the accretion luminosity or upper limit is measurable only when the image is binned over large wavelength intervals. This method extends our sensitivity to accretion rate down to ∼10 -13 M sun yr -1 for brown dwarfs. Since the ability to measure an accretion rate from excess Balmer continuum emission depends on the contrast between excess continuum emission and the underlying photosphere, for objects with earlier spectral types the upper limit on accretion rate is much higher. Absolute uncertainties in our accretion rate measurements of ∼3-5 include uncertainty in accretion models, brown dwarf masses, and distance. The accretion rate of 2 x 10 -12 M sun yr -1 onto 2MASS J12073347-3932540 is within 15% of two previous measurements, despite large changes in the Hα flux.

  7. Arctic Browning: vegetation damage and implications for carbon balance.

    Science.gov (United States)

    Treharne, Rachael; Bjerke, Jarle; Emberson, Lisa; Tømmervik, Hans; Phoenix, Gareth

    2016-04-01

    'Arctic browning' is the loss of biomass and canopy in Arctic ecosystems. This process is often driven by climatic and biological extreme events - notably extreme winter warm periods, winter frost-drought and severe outbreaks of defoliating insects. Evidence suggests that browning is becoming increasingly frequent and severe at the pan-arctic scale, a view supported by observations from more intensely observed regions, with major and unprecedented vegetation damage reported at landscape (>1000km2) and regional (Nordic Arctic Region) scales in recent years. Critically, the damage caused by these extreme events is in direct opposition to 'Arctic greening', the well-established increase in productivity and shrub abundance observed at high latitudes in response to long-term warming. This opposition creates uncertainty as to future anticipated vegetation change in the Arctic, with implications for Arctic carbon balance. As high latitude ecosystems store around twice as much carbon as the atmosphere, and vegetation impacts are key to determining rates of loss or gain of ecosystem carbon stocks, Arctic browning has the potential to influence the role of these ecosystems in global climate. There is therefore a clear need for a quantitative understanding of the impacts of browning events on key ecosystem carbon fluxes. To address this, field sites were chosen in central and northern Norway and in Svalbard, in areas known to have been affected by either climatic extremes or insect outbreak and subsequent browning in the past four years. Sites were chosen along a latitudinal gradient to capture both conditions already causing vegetation browning throughout the Norwegian Arctic, and conditions currently common at lower latitudes which are likely to become more damaging further North as climate change progresses. At each site the response of Net Ecosystem CO2 Exchange to light was measured using a LiCor LI6400 Portable Photosynthesis system and a custom vegetation chamber with

  8. Necrotic skin lesion in a dog attributed to Loxosceles (brown spider bite: a case report

    Directory of Open Access Journals (Sweden)

    LHA Machado

    2009-01-01

    Full Text Available Envenomations caused by Loxosceles (brown spider have been reported throughout the world. Clinical signs associated to bites of these spiders involve dermonecrotic lesions and intense local inflammatory response, besides systemic manifestations such as intravascular hemolysis, thrombocytopenia, disseminated intravascular coagulation and acute renal failure. The present study aimed to report and to describe dermonecrotic lesions probably caused by a Loxosceles envenomation in a four year-old poodle female dog, treated at the Dermatology Service of the Veterinary Hospital of the Veterinary Medicine and Animal Husbandry School, São Paulo State University, Botucatu, Brazil. Initially, the animal presented two skin lesions with blackish aspect that evolved into ulcerative crusts. The owner reported the presence of a brown spider near the place where the animal spent most of the time. Histological examination of lesions revealed necrosis of the epidermis extending to adnexa and panniculi, which is compatible with Loxosceles bite reaction. The animal was treated with systemic antibiotic and local curatives. Lesions healed by second intention in two months.

  9. [Effect of sulfated polysaccharides from brown algae on proliferative and cytotoxic activity of mice splenocytes].

    Science.gov (United States)

    Makarenkova, I D; Semenova, I B; Akhmatova, N K; Besednova, N N; Zviagintseva, T N; Ermakova, S P

    2012-01-01

    Study effect of fucoidans from brown algae on proliferative and cytotoxic activity of mice splenocytes. Proliferative and cytotoxic activity of mice splenocytes in vitro and ex vivo were studied in lymphocyte blast transformation reaction and in cytotoxic MTT-test on K562 human erythroblast leucosis cell line. Microphotography and microscopy were performed by using Axiocam HS photosystem and computer program AxioVision 4 (Germany). Fucoidans from brown algae Fucus evanescens, Laminaria cichorioides and Laminaria japonica in vitro and ex vivo systems were established to increase proliferative activity of mice splenocytes which is evidenced by an increase of stimulation index. Results of in vitro and ex vivo cytotoxic activity studies demonstrate that fucoidans which are various by chemical structure stimulate activity of NK-cells and facilitate an increase of splenocyte cytotoxic potential level against NK sensitive K562 cell line. The data obtained from the study demonstrate an ability of fucoidans to stimulate splenocyte proliferation and NK-cell killer activity, and studies of relation between structure and functions of sulfated polysaccharides facilitate a more detailed understanding of aspects of their mechanism of action on innate immunity system, thus providing the basis for development of new immunobiologic preparations - modifiers/agonists of innate immunity.

  10. Acute Post-Prandial Cognitive Effects of Brown Seaweed Extract in Humans

    Directory of Open Access Journals (Sweden)

    Crystal F. Haskell-Ramsay

    2018-01-01

    Full Text Available (Polyphenols and, specifically, phlorotannins present in brown seaweeds have previously been shown to inhibit α-amylase and α-glucosidase, key enzymes involved in the breakdown and intestinal absorption of carbohydrates. Related to this are observations of modulation of post-prandial glycemic response in mice and increased insulin sensitivity in humans when supplemented with seaweed extract. However, no studies to date have explored the effect of seaweed extract on cognition. The current randomized, placebo-controlled, double-blind, parallel groups study examined the impact of a brown seaweed extract on cognitive function post-prandially in 60 healthy adults (N = 30 per group. Computerized measures of episodic memory, attention and subjective state were completed at baseline and 5 times at 40 min intervals over a 3 h period following lunch, with either seaweed or placebo consumed 30 min prior to lunch. Analysis was conducted with linear mixed models controlling for baseline. Seaweed led to significant improvements to accuracy on digit vigilance (p = 0.035 and choice reaction time (p = 0.043 tasks. These findings provide the first evidence for modulation of cognition with seaweed extract. In order to explore the mechanism underlying these effects, future research should examine effects on cognition in parallel with blood glucose and insulin responses.

  11. Examining Cloud, Metallicity, and Gravity signatures in Brown Dwarfs

    Science.gov (United States)

    Gonzales, Eileen; Faherty, Jacqueline K.; Gagné, Jonathan; Artigau, Étienne; BDNYC

    2018-01-01

    The nearby solar neighborhood is littered with low mass, low temperature objects called brown dwarfs. This population of ultracool objects do not have enough mass to sustain stable hydrogen burning so they never enter the main sequence and simply cool through time. Brown dwarfs span effective temperatures in the range 250 to 3000K. They also have age dependent observable properties. Young brown dwarfs appear to have redder near infrared colors than field age sources, while old objects tend to have bluer colors. Over the past several years, the research group entitled “Brown Dwarfs in New York City” (BDNYC) has been collecting optical, near and mid-infrared spectra, as well as photometry for sources that have well defined distances. In this poster, I will compare the distance calibrated spectral energy distributions of a sample of old, young, and field age brown dwarfs of the same effective temperature. In so doing, I will discern observables linked to gravity, atmosphere, metallicity and age effects.

  12. Monoclonal antibodies directed to fucoidan preparations from brown algae.

    Science.gov (United States)

    Torode, Thomas A; Marcus, Susan E; Jam, Murielle; Tonon, Thierry; Blackburn, Richard S; Hervé, Cécile; Knox, J Paul

    2015-01-01

    Cell walls of the brown algae contain a diverse range of polysaccharides with useful bioactivities. The precise structures of the sulfated fucan/fucoidan group of polysaccharides and their roles in generating cell wall architectures and cell properties are not known in detail. Four rat monoclonal antibodies, BAM1 to BAM4, directed to sulfated fucan preparations, have been generated and used to dissect the heterogeneity of brown algal cell wall polysaccharides. BAM1 and BAM4, respectively, bind to a non-sulfated epitope and a sulfated epitope present in the sulfated fucan preparations. BAM2 and BAM3 identified additional distinct epitopes present in the fucoidan preparations. All four epitopes, not yet fully characterised, occur widely within the major brown algal taxonomic groups and show divergent distribution patterns in tissues. The analysis of cell wall extractions and fluorescence imaging reveal differences in the occurrence of the BAM1 to BAM4 epitopes in various tissues of Fucus vesiculosus. In Ectocarpus subulatus, a species closely related to the brown algal model Ectocarpus siliculosus, the BAM4 sulfated epitope was modulated in relation to salinity levels. This new set of monoclonal antibodies will be useful for the dissection of the highly complex and yet poorly resolved sulfated polysaccharides in the brown algae in relation to their ecological and economic significance.

  13. Boron uptake, localization, and speciation in marine brown algae.

    Science.gov (United States)

    Miller, Eric P; Wu, Youxian; Carrano, Carl J

    2016-02-01

    In contrast to the generally boron-poor terrestrial environment, the concentration of boron in the marine environment is relatively high (0.4 mM) and while there has been extensive interest in its use as a surrogate of pH in paleoclimate studies in the context of climate change-related questions, the relatively depth independent, and the generally non-nutrient-like concentration profile of this element have led to boron being neglected as a potentially biologically relevant element in the ocean. Among the marine plant-like organisms the brown algae (Phaeophyta) are one of only five lineages of photosynthetic eukaryotes to have evolved complex multicellularity. Many of unusual and often unique features of brown algae are attributable to this singular evolutionary history. These adaptations are a reflection of the marine coastal environment which brown algae dominate in terms of biomass. Consequently, brown algae are of fundamental importance to oceanic ecology, geochemistry, and coastal industry. Our results indicate that boron is taken up by a facilitated diffusion mechanism against a considerable concentration gradient. Furthermore, in both Ectocarpus and Macrocystis some boron is most likely bound to cell wall constituent alginate and the photoassimilate mannitol located in sieve cells. Herein, we describe boron uptake, speciation, localization and possible biological function in two species of brown algae, Macrocystis pyrifera and Ectocarpus siliculosus.

  14. FINE STRUCTURE AND ORGANELLE ASSOCIATIONS IN BROWN ALGAE

    Science.gov (United States)

    Bouck, G. Benjamin

    1965-01-01

    The structural interrelationships among several membrane systems in the cells of brown algae have been examined by electron microscopy. In the brown algae the chloroplasts are surrounded by two envelopes, the outer of which in some cases is continuous with the nuclear envelope. The pyrenoid, when present, protrudes from the chloroplast, is also surrounded by the two chloroplast envelopes, and, in addition, is capped by a third dilated envelope or "pyrenoid sac." The regular apposition of the membranes around the pyrenoid contrasts with their looser appearance over the remainder of the chloroplast. The Golgi apparatus is closely associated with the nuclear envelope in all brown algae examined, but in the Fucales this association may extend to portions of the cytoplasmic endoplasmic reticulum as well. Evidence is presented for the derivation of vesicles, characteristic of those found in the formative region of the Golgi apparatus, from portions of the underlying nuclear envelope. The possibility that a structural channeling system for carbohydrate reserves and secretory precursors may be present in brown algae is considered. Other features of the brown algal cell, such as crystal-containing bodies, the variety of darkly staining vacuoles, centrioles, and mitochondria, are examined briefly, and compared with similar structures in other plant cells. PMID:5865936

  15. Monoclonal antibodies directed to fucoidan preparations from brown algae.

    Directory of Open Access Journals (Sweden)

    Thomas A Torode

    Full Text Available Cell walls of the brown algae contain a diverse range of polysaccharides with useful bioactivities. The precise structures of the sulfated fucan/fucoidan group of polysaccharides and their roles in generating cell wall architectures and cell properties are not known in detail. Four rat monoclonal antibodies, BAM1 to BAM4, directed to sulfated fucan preparations, have been generated and used to dissect the heterogeneity of brown algal cell wall polysaccharides. BAM1 and BAM4, respectively, bind to a non-sulfated epitope and a sulfated epitope present in the sulfated fucan preparations. BAM2 and BAM3 identified additional distinct epitopes present in the fucoidan preparations. All four epitopes, not yet fully characterised, occur widely within the major brown algal taxonomic groups and show divergent distribution patterns in tissues. The analysis of cell wall extractions and fluorescence imaging reveal differences in the occurrence of the BAM1 to BAM4 epitopes in various tissues of Fucus vesiculosus. In Ectocarpus subulatus, a species closely related to the brown algal model Ectocarpus siliculosus, the BAM4 sulfated epitope was modulated in relation to salinity levels. This new set of monoclonal antibodies will be useful for the dissection of the highly complex and yet poorly resolved sulfated polysaccharides in the brown algae in relation to their ecological and economic significance.

  16. Being Black and Brown in the 21st Century

    Directory of Open Access Journals (Sweden)

    Pierre W. Orelus

    2012-11-01

    Full Text Available Depending on one’s level of understanding and awareness about the plight of Black and Brown people, one might argue that they are better off today than they were 50 years ago or so, especially when one remembers the Jim Crow era during which Black and Brown people were ruthlessly brutalized, particularly by White supremacist groups such as the Klu Klux Kan. However, if one critically analyzed the achievement gap between students of color and their White counterparts, the decline in incomes, and other forms of educational and socioeconomic inequality that Black and Brown people, particularly poor students of color, have been experiencing for the last several decades or so, one would realize that substantially nothing has changed for them. In light of this view, this article explores the educational and socioeconomic conditions of People of Color, including those of linguistically and culturally diverse students. Specifically, it examines the ways and the degree to which lack of resources combined with institutional racism and the legacy of slavery continue to limit the life chances of Black and Brown people in the 21st century. The author ends this article making recommendations to counter inequality in schools and society at large that Black and Brown people have been facing.

  17. Detecting magnetic fields on brown dwarfs and exoplanets

    Science.gov (United States)

    Berdyugina, Svetlana

    2017-05-01

    There is growing evidence that brown dwarfs may possess rather strong magnetic fields, similar to active, early M-type red dwarf stars. Strong clues come from extremely energetic flares detected in UV, X-ray and optical line emission as well as quiescent and transient radio emission and bursts. Our recent spectropolarimetric study of one such active brown dwarf has revealed a 5 kG magnetic spot on its surface. The emitting region topology recovered using spectral line profile inversions indicates the presence of a hot plasma large-scale loop of at least 7000 K with a vertical stratification of the sources producing both optical and radio emission. This loop rotates with the dwarf in and out of view causing the emission bursts. The 5 kG magnetic field is detected at the base of the loop. This result provides the first direct observational constraint for a magnetically driven non-thermal emission mechanism and for generation of magnetic fields in fully convective brown dwarfs. It also paves a path towards magnetic studies of hot Jupiters of similar temperatures. We model relevant atomic lines and molecular bands in order to predict spectropolarimetric signals due to magnetic fields on brown dwarfs, hot Jupiters and other types of exoplanets. This exercise helps to determine instrumental requirements for magnetic surveys of brown dwarfs and exoplanets.

  18. Brown adipose tissue in morbidly obese subjects.

    Directory of Open Access Journals (Sweden)

    Guy H E J Vijgen

    Full Text Available BACKGROUND: Cold-stimulated adaptive thermogenesis in brown adipose tissue (BAT to increase energy expenditure is suggested as a possible therapeutic target for the treatment of obesity. We have recently shown high prevalence of BAT in adult humans, which was inversely related to body mass index (BMI and body fat percentage (BF%, suggesting that obesity is associated with lower BAT activity. Here, we examined BAT activity in morbidly obese subjects and its role in cold-induced thermogenesis (CIT after applying a personalized cooling protocol. We hypothesize that morbidly obese subjects show reduced BAT activity upon cold exposure. METHODS AND FINDINGS: After applying a personalized cooling protocol for maximal non-shivering conditions, BAT activity was determined using positron-emission tomography and computed tomography (PET-CT. Cold-induced BAT activity was detected in three out of 15 morbidly obese subjects. Combined with results from lean to morbidly obese subjects (n = 39 from previous study, the collective data show a highly significant correlation between BAT activity and body composition (P<0.001, respectively explaining 64% and 60% of the variance in BMI (r = 0.8; P<0.001 and BF% (r = 0.75; P<0.001. Obese individuals demonstrate a blunted CIT combined with low BAT activity. Only in BAT-positive subjects (n = 26 mean energy expenditure was increased significantly upon cold exposure (51.5±6.7 J/s versus 44.0±5.1 J/s, P = 0.001, and the increase was significantly higher compared to BAT-negative subjects (+15.5±8.9% versus +3.6±8.9%, P = 0.001, indicating a role for BAT in CIT in humans. CONCLUSIONS: This study shows that in an extremely large range of body compositions, BAT activity is highly correlated with BMI and BF%. BAT-positive subjects showed higher CIT, indicating that BAT is also in humans involved in adaptive thermogenesis. Increasing BAT activity could be a therapeutic target in (morbid obesity.

  19. Chain reaction

    International Nuclear Information System (INIS)

    Balogh, Brian.

    1991-01-01

    Chain Reaction is a work of recent American political history. It seeks to explain how and why America came to depend so heavily on its experts after World War II, how those experts translated that authority into political clout, and why that authority and political discretion declined in the 1970s. The author's research into the internal memoranda of the Atomic Energy Commission substantiates his argument in historical detail. It was not the ravages of American anti-intellectualism, as so many scholars have argued, that brought the experts back down to earth. Rather, their decline can be traced to the very roots of their success after World War II. The need to over-state anticipated results in order to garner public support, incessant professional and bureaucratic specialization, and the sheer proliferation of expertise pushed arcane and insulated debates between experts into public forums at the same time that a broad cross section of political participants found it easier to gain access to their own expertise. These tendencies ultimately undermined the political influence of all experts. (author)

  20. Dangerous reef aquaristics: Palytoxin of a brown encrusting anemone causes toxic corneal reactions.

    Science.gov (United States)

    Ruiz, Yasmin; Fuchs, Joan; Beuschel, Ralf; Tschopp, Markus; Goldblum, David

    2015-11-01

    Although frequently observed in domestic saltwater aquariums, literature on exposure to palytoxin (PTX) of encrusting anemones (Zoanthidea) kept in aquariums is rare. Handling these animals for propagation purposes or during cleaning work can lead to dermal, ocular or respiratory contact with the PTX generated by some Zoanthids. The present study describes a case of ocular exposure to liquid from a Zoanthid, which led to corneal ulcers. The patient also suffered from systemic symptoms of dyspnea and shivering and a suspected rhabdomyolysis, which required monitoring in the Intensive Care Unit. After symptomatic treatment provided insufficient results, the corneal ulcers improved with an amniotic membrane transplantation. A review of the literature regarding ocular exposures to this diverse order of Hexacorallia reveals that severe and systemic symptoms can develop with minimal contact. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Investigation of oxidative degradation and non‐enzymatic browning reactions in krill and fish oils

    DEFF Research Database (Denmark)

    Thomsen, Birgitte Raagaard; Haugsgjerd, Bjørn Ole; Griinari, Mikko

    2013-01-01

    substance (TBARS), conjugated dienes and trienes, and antioxidant content, and (ii) advanced methods such as determination of volatiles content by dynamic headspace (DHS)‐GC/MS, lipid classes, and pyrrole content. In addition, the oxidative stability of the oils was evaluated under accelerated oxidation...... of these classical methods. Nevertheless, the conclusion was supported by the results of the Oxipres™ measurements, which showed that the oxygen consumption was higher for fish oil. Furthermore, the level of most volatile lipid oxidation products was higher for fish oil. The development of Strecker degradation...

  2. Interspecific variation in total phenolic content in temperate brown algae

    Directory of Open Access Journals (Sweden)

    Anna Maria Mannino

    2017-09-01

    Full Text Available Marine algae synthesize secondary metabolites such as polyphenols that function as defense and protection mechanisms. Among brown algae, Fucales and Dictyotales (Phaeophyceae contain the highest levels of phenolic compounds, mainly phlorotannins, that play multiple roles. Four temperate brown algae (Cystoseira amentacea, Cystoseira compressa, Dictyopteris polypodioides and Padina pavonica were studied for total phenolic contents. Total phenolic content was determined colorimetrically with the Folin-Ciocalteu reagent. Significant differences in total phenolic content were observed between leathery and sheetlike algae and also within each morphological group. Among the four species, the sheet-like alga D. polypodioides, living in the upper infralittoral zone, showed the highest concentration of phenolic compounds. These results are in agreement with the hypothesis that total phenolic content in temperate brown algae is influenced by a combination of several factors, such as growth form, depth, and exposition to solar radiation.

  3. Potential pharmacological applications of polyphenolic derivatives from marine brown algae.

    Science.gov (United States)

    Thomas, Noel Vinay; Kim, Se-Kwon

    2011-11-01

    Recently, the isolation and characterization of the biologically active components from seaweeds have gained much attention from various research groups across the world. The marine algae have been studied for biologically active components and phlorotannins are one among them. Among marine algae, brown algal species such as Ecklonia cava, Eisenia arborea, Ecklonia stolinifera and Eisenia bicyclis have been studied for their potential biological activities. Majority of the investigations on phlorotannins derived from brown algae have exhibited their potentiality as antioxidant, anti-inflammatory, antidiabetic, antitumor, antihypertensive, anti-allergic, hyaluronidase enzyme inhibition and in matrix metalloproteinases (MMPs) inhibition activity. In this review, we have made an attempt to discuss the potential biological activities of phlorotannins from marine brown algae and their possible candidature in the pharmaceutical applications. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Helminths of brown bears (Ursus arctos) in the Kola Peninsula.

    Science.gov (United States)

    Bugmyrin, S V; Tirronen, K F; Panchenko, D V; Kopatz, A; Hagen, S B; Eiken, H G; Kuznetsova, A S

    2017-06-01

    We present data on the species composition of helminths in brown bears (Ursus arctos) from the Murmansk Region, Russia. The absence of any information about helminths of brown bear in the region necessitated the conduct of these studies. Samples were collected in 2014 and 2015 in the southern part of the Kola Peninsula from the White Sea coastal habitats. Annually, in the study area, 1-3 bears are legally hunted and biological samples for examination are very difficult to obtain. Therefore, we used fecal samples. We studied 93 feces and identified parasite eggs identified in 43 of them by morphometric criteria. The surveys revealed eggs of the following helminths: Dicrocoelium sp., Diphyllobothrium sp., Anoplocephalidae, Capillariidae, Baylisascaris sp., Strongylida 1, and Strongylida 2. These results represent the first reconnaissance stage, which allowed characterizing the taxonomic diversity and prevalence of parasites of brown bears of the Kola Peninsula.

  5. Brown Tumor Shown Flare Phenomenon On Bone Scan After Parathyroidectomy

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Kwang Ho; Park, Seol Hoon; Baek, So Ra; Chae, Sun Young; Koh, Jung Min; Kim, Jae Seung; Moon, Dae Hyuk; Ryu, Jin Sook [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2009-10-15

    Brown tumor is the benign bone lesion consists of woven bone and fibrous tissue without matrix, which develop due to chronic excessive osteoclastic activity such as hyperparathyroidism. Usually they appear with normal uptake or occasionally focally increased uptake on bone scan. We present a case with brown tumor shown more increased uptake and more number of lesions on bone scan after parathyroidectomy, and lesser increased uptake on serial bone scans without any other treatment through several months. This finding is thought to be similar to 'flare phenomenon' which is occasionally seen after treatment of metastatic bone lesions of malignant cancer, and may represent curative process of brown tumor with rapid normal bone formation.

  6. Plume trajectory validation study: Brown cloud support project overview

    International Nuclear Information System (INIS)

    Brown-Strattan, M.A.; Smith, M.L.

    1991-01-01

    The brown cloud is an air pollution phenomenon of great concern to the Denver metropolitan area. Regulatory agencies, academia, and research organizations are involved in characterizing the development and transport of the brown cloud and identifying mitigation approaches. In support of this effort, NOAA conducted releases of small (one cubic meter) constant density balloons from sites in Denver and along the South Platte Valley. These balloons, called ''tetroons'' because of their tetrahedral shape, carried five-ounce transponders and were tracked by radar as they rose to predetermined altitudes and followed airflow patterns at those altitudes. The data gathered from these releases included the geographic position and altitude of each tetroon over time. These data will aid efforts to understand brown cloud development, structure, and transport

  7. Characterization of the Mysteriously Cool Brown Dwarf HD 4113

    Science.gov (United States)

    Ednie, Michaela; Follette, Katherine; Ward-Duong, Kimberly

    2018-01-01

    Characterizing the physical properties of brown dwarfs is necessary to expand and improve our understanding of low mass companions, including exoplanets. Systems with both close radial velocity companions and distant directly imaged companions are particularly powerful in understanding planet formation mechanisms. Early in 2017, members of the SPHERE team discovered a companion brown dwarf in the HD 4113 system, which also contains a known RV planet. Atmospheric model fits to the Y and J-band spectra and H2/H3 photometry of the brown dwarf suggested it is unusually cool. We obtained new Magellan data in the Z and K’ bands in mid-2017. This data will help us to complete a more detailed atmospheric and astrometric characterization of this unusually cool companion. Broader wavelength coverage will help in accurate spectral typing and estimations of luminosity, temperature, surface gravity, radius, and composition. Additionally, a second astrometric epoch will help constrain the architecture of the system.

  8. EVALUATION OF BROWN COAL SPONTANEOUS COMBUSTION AND SOURCES GENESIS PROGNOSES

    Directory of Open Access Journals (Sweden)

    Vlastimil MONI

    2014-10-01

    Full Text Available This article presents summarizing information about the solution of partial part of research problem of prognoses of deposited brown coal spontaneous combustion sources genesis as a part of project TA01020351 – program ALFA. We will gradually describe the results of long term measurements carried out on selected brown coal heaps realized from 2011 to 2013. The attention is devoted to characterization of key parameters. These parameters influence the genesis of combustion. The second problem is the comparison of results of thermal imaging with laboratory results of gas and coal samples sampled in situ, with the influence of atmospheric conditions (insolation, aeration, rainfall, atmospheric pressure changes etc., with influence of coal mass degradation, physical and chemical factors and another failure factors to brown coal spontaneous combustion processes.

  9. The Genetics of Brown Adipocyte Induction in White Fat Depots

    Directory of Open Access Journals (Sweden)

    Leslie P. Kozak

    2011-10-01

    Full Text Available Evidence that adult humans have functional brown adipose tissue has stirred interest in the possibility that the impressive effectiveness of induction of brown adipocytes to reduce obesity in mice may be translated to the human condition. A major focus recently on the identification of signaling and transcription factor that stimulate the induction of brown adipocytes has come from transgenic and gene KO models. However, these models have created a very complex picture of the regulatory mechanisms for brown fat induction. In this review insights into the critical regulatory pathways involved in brown adipocyte induction in the retroperitoneal fat depot of mice are described from quantitative trait locus analysis of allelic variability determining Ucp1 levels and brown adipocyte induction in A/J vs B6 mice. The key observation is that recombinant genotypes, found in recombinant inbred stains and backcross and intercross progeny , show transgressive variation for Ucp1 mRNA levels. These genetic crosses also show that the levels of Ucp1 mRNA are determined by interactions that control the levels of PPARα, PGC-1α and type 2 deiodinase and that each factor is controlled by a subset of QTLs that also control Ucp1expression. These results indicate that induction of Ucp1 in the retroperitoneal fat depot involves synergy between signaling and transcription factors that vary depending upon the environmental conditions. Inherent in this model is the idea that there is a high level of redundancy that can involve any factor with the potential to influence expression of the core factors, PPARα, PGC-1a and DIO2.

  10. Effect of hydrothermal dewatering on the slurryability of brown coals

    International Nuclear Information System (INIS)

    Yu Yujie; Liu Jianzhong; Wang Ruikun; Zhou Junhu; Cen Kefa

    2012-01-01

    Highlights: ► Brown coals are upgraded by hydrothermal dewatering. ► The moisture content and oxygen functional groups decrease during the process. ► The point of zero charge and the contact angle rise as the temperature increases. ► The products were highly hydrophobic. ► The improvement on slurryability of solid products were examined. - Abstract: Two brown coals from China were dewatered under hydrothermal dewatering (HTD) conditions at 250–320 °C for 1 h in a 2 L autoclave. The hydrothermally dewatered products were used to prepare coal water slurry (CWS) with a lower viscosity than brown raw coal slurry. Moreover, the coal rank and heat value of the brown coal increased as the inherent moisture and oxygen content decreased during the HTD process. The maximum solid concentration of CWS prepared from XiMeng coal increased from 45.7% to 59.3%, whereas that of CWS prepared from BaoTou coal increased from 53.7% to 62.1%, after being dewatered at 320 °C. The improvement in the slurryability of brown coal significantly depended on the final temperature of the HTD process, the mechanism of which can be explained by the chemical analysis of oxygen functional groups, zeta potential, and the contact angle of the surface between coal and water. The oxygen functional groups, the oxygen/carbon ratio and hydrogen/carbon ratio in brown coal decreased, indicating that the coal rank was upgraded during the HTD process. As a result, both the point of zero charge and the contact angle increased, implying that the HTD products were highly hydrophobic.

  11. Effect of germination on chemical, functional and nutritional characteristics of wheat, brown rice and triticale: a comparative study.

    Science.gov (United States)

    Sibian, Mandeep S; Saxena, Dharmesh C; Riar, Charanjit S

    2017-10-01

    Germination is accompanied by various metabolic reactions in the seed, which lead to alteration of its chemical composition as compared to raw seed. Among the micromolecules, amino acids play an important role in various growth and metabolic activities in seeds. Results indicated that germination altered seeds' chemical composition, which improved/changed the functional properties investigated such as bulk density, foaming capacity, water holding capacity, oil binding capacity and emulsification properties. Essential amino acids were increased during germination, which contributed in enhancing the nutritional quality of protein in seeds. Germination also improved protein-based quality parameters such as essential amino acid index, biological value, protein efficiency ratio and nutritional index in seeds of brown rice, wheat and triticale. Among the grains, the essential amino acid index of brown rice was reported to be highest after germination. Indispensable/essential amino acids such as lysine, methionine, leucine, isoleucine, threonine, phenylalanine and valine showed a significant increase during germination. As a result, amino acid scoring based on the reference pattern of an FAO Expert Consultation Report (2013) for infants and adults was appreciably improved after germination along with an increase in the essential amino acid indices for brown rice (78.78), wheat (76.55) and triticale (73.99). © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. Local adaptation in brown trout early life-history traits: implications for climate change adaptability

    DEFF Research Database (Denmark)

    Jensen, L.F.; Hansen, Michael Møller; Pertoldi, C.

    2008-01-01

      Knowledge of local adaptation and adaptive potential of natural populations is becoming increasingly relevant due to anthropogenic changes in the environment, such as climate change. The concern is that populations will be negatively affected by increasing temperatures without the capacity...... to adapt. Temperature-related adaptability in traits related to phenology and early life history are expected to be particularly important in salmonid fishes. We focused on the latter and investigated whether four populations of brown trout (Salmo trutta) are locally adapted in early life-history traits...... traits, indicating local adaptation. A temperature effect was observed for three traits. However, this effect varied among populations due to locally adapted reaction norms, corresponding to the temperature regimes experienced by the populations in their native environments. Additive genetic variance...

  13. The brown spider Loxosceles laeta: source of the remedy Tarentula cubensis?

    Science.gov (United States)

    Richardson-Boedler, C

    2002-07-01

    The homeopathic remedy Tarentula cubensis (Cuban tarantula), used in homeopathy to treat abscesses with burning pains, gangrene, septicaemia, toxaemia, has been grouped by homeopathic authorities with either the mygalomorph or wolf spiders. The original specimen used for preparation of the mother tincture was decomposed, leaving the spider's exact identity in doubt. Investigation of the toxicological and clinical literature, compared with homeopathic materia medica, reveals the brown spider, Loxosceles laeta, indigenous to South America but present also in Mid- and North America, as a more likely source. Venoms of spiders of the genus Loxosceles cause severe necrotic arachnidism, as well as, in some cases, a life-threatening systemic reaction marked by renal failure, disseminated intravascular coagulation, thrombocytopeania, coma and convulsions.

  14. Energy balance associated with the degradation of lignocellulosic material by white-rot and brown-rot fungi.

    Science.gov (United States)

    Derrien, Delphine; Bédu, Hélène; Buée, Marc; Kohler, Annegret; Goodell, Barry; Gelhaye, Eric

    2017-04-01

    Forest soils cover about 30% of terrestrial area and comprise between 50 and 80% of the global stock of soil organic carbon (SOC). The major precursor for this forest SOC is lignocellulosic material, which is made of polysaccharides and lignin. Lignin has traditionally been considered as a recalcitrant polymer that hinders access to the much more labile structural polysaccharides. This view appears to be partly incorrect from a microbiology perspective yet, as substrate alteration depends on the metabolic potential of decomposers. In forest ecosystems the wood-rotting Basidiomycota fungi have developed two different strategies to attack the structure of lignin and gain access to structural polysaccharides. White-rot fungi degrade all components of plant cell walls, including lignin, using enzymatic systems. Brown-rot fungi do not remove lignin. They generate oxygen-derived free radicals, such as the hydroxyl radical produced by the Fenton reaction, that disrupt the lignin polymer and depolymerize polysaccharides which then diffuse out to where the enzymes are located The objective of this study was to develop a model to investigate whether the lignin relative persistence could be related to the energetic advantage of brown-rot degradative pathway in comparison to white-rot degradative pathway. The model simulates the changes in substrate composition over time, and determines the energy gained from the conversion of the lost substrate into CO2. The energy cost for the production of enzymes involved in substrate alteration is assessed using information derived from genome and secretome analysis. For brown-rot fungus specifically, the energy cost related to the production of OH radicals is also included. The model was run, using data from the literature on populous wood degradation by Trametes versicolor, a white-rot fungus, and Gloeophyllum trabeum, a brown-rot fungus. It demonstrates that the brown-rot fungus (Gloeophyllum trabeum) was more efficient than the white

  15. Adsorption of Heavy Metals on Biologically Activated Brown Coal Sludge

    Directory of Open Access Journals (Sweden)

    Mária Praščáková

    2005-11-01

    Full Text Available Adsorption of cooper (II and zinc (II ions from aqueous solutions on a biologically activated brown coal sludge was investigated. Four families of adsorbents were prepared from the brown coal sludge bya microorganism’s activity. There were used microscopic fungi such as Aspergillus niger, Aspergillus clavatus, Penicillium glabrum and Trichoderma viride. Prepared sorbents were capable of removing Cu (II and Zn (II. The sorption isotherm has been constructed and the specific metal uptake and the maximum capacity of the adsorbent have been determined.

  16. Tool-use in the brown bear (Ursus arctos)

    OpenAIRE

    Deecke, Volker B.

    2012-01-01

    This is the first report of tool-using behaviour in a wild brown bear (Ursus arctos). Whereas the use of tools is comparatively common among primates and has also been documented in several species of birds, fishes and invertebrates, tool-using behaviours have so far been observed in only four species of non-primate mammal. The observation was made and photographed while studying the behaviour of a subadult brown bear in southeastern Alaska. The animal repeatedly picked up barnacle-encrusted ...

  17. A brown dwarf orbiting an M-dwarf

    DEFF Research Database (Denmark)

    Bachelet, E.; Fouque, P.; Han, C.

    2012-01-01

    gives two local minima, which correspond to the theoretical degeneracy s ≡ s-1. We find that the lens is composed of a brown dwarf secondary of mass MS = 0.05 M⊙ orbiting a primary M-star of mass MP = 0.18 M⊙. We also reveal a new mass-ratio degeneracy for the central caustics of close binaries....... Conclusions. As far as we are aware, this is the first detection using the microlensing technique of a binary system in our Galaxy composed of an M-star and a brown dwarf....

  18. The pore structure in processed Victorian Brown coal.

    Science.gov (United States)

    McMahon, P J; Snook, I K; Treimer, W

    2002-08-01

    Changes in the pore structure of Victorian Brown coal when upgraded with heated gases under pressure are investigated. We show that the results obtained from ultra-small-angle neutron scattering (USANS) measurements agree with previous results using small-angle X-ray scattering results but that USANS may also be used to investigate the meso porosity. Findings from small-angle scattering are confirmed using electron microscopy. We also show evidence from electron diffraction that thermal conditions within the brown coals during the upgrade procedure may be far more extreme than previously thought.

  19. The pore structure in processed Victorian brown coal

    Energy Technology Data Exchange (ETDEWEB)

    McMahon, P.J.; Snook, I.K.; Treimer, W. [University of Melbourne, Melbourne, Vic. (Australia). School of Physics

    2002-07-01

    Changes in the pore structure of Victorian Brown coal when upgraded with heated gases under pressure are investigated. It is shown that the results obtained from ultra-small-angle neutron scattering (USANS) measurements agree with previous results using small-angle X-ray scattering results but that USANS may also be used to investigate the meso porosity. Findings from small-angle scattering are confirmed using electron microscopy. Evidence is given from electron diffraction that thermal conditions within the brown coals during the upgrade procedure may be far more extreme than previously thought.

  20. HUBBLE SPIES BROWN DWARFS IN NEARBY STELLAR NURSERY

    Science.gov (United States)

    2002-01-01

    Probing deep within a neighborhood stellar nursery, NASA's Hubble Space Telescope uncovered a swarm of newborn brown dwarfs. The orbiting observatory's near-infrared camera revealed about 50 of these objects throughout the Orion Nebula's Trapezium cluster [image at right], about 1,500 light-years from Earth. Appearing like glistening precious stones surrounding a setting of sparkling diamonds, more than 300 fledgling stars and brown dwarfs surround the brightest, most massive stars [center of picture] in Hubble's view of the Trapezium cluster's central region. All of the celestial objects in the Trapezium were born together in this hotbed of star formation. The cluster is named for the trapezoidal alignment of those central massive stars. Brown dwarfs are gaseous objects with masses so low that their cores never become hot enough to fuse hydrogen, the thermonuclear fuel stars like the Sun need to shine steadily. Instead, these gaseous objects fade and cool as they grow older. Brown dwarfs around the age of the Sun (5 billion years old) are very cool and dim, and therefore are difficult for telescopes to find. The brown dwarfs discovered in the Trapezium, however, are youngsters (1 million years old). So they're still hot and bright, and easier to see. This finding, along with observations from ground-based telescopes, is further evidence that brown dwarfs, once considered exotic objects, are nearly as abundant as stars. The image and results appear in the Sept. 20 issue of the Astrophysical Journal. The brown dwarfs are too dim to be seen in a visible-light image taken by the Hubble telescope's Wide Field and Planetary Camera 2 [picture at left]. This view also doesn't show the assemblage of infant stars seen in the near-infrared image. That's because the young stars are embedded in dense clouds of dust and gas. The Hubble telescope's near-infrared camera, the Near Infrared Camera and Multi-Object Spectrometer, penetrated those clouds to capture a view of those

  1. 403 nm cavity ring-down measurements of brown carbon aerosol

    Science.gov (United States)

    Kwon, D.; Grassian, V. H.; Kleiber, P.; Young, M. A.

    2017-12-01

    Atmospheric aerosol influences Earth's climate by absorbing and scattering incoming solar radiation and outgoing terrestrial radiation. One class of secondary organic aerosol (SOA), called brown carbon (BrC), has attracted attention for its wavelength dependent light absorbing properties with absorption coefficients that generally increase from the visible (Vis) to ultraviolet (UV) regions. Here we report results from our investigation of the optical properties of BrC aerosol products from the aqueous phase reaction of ammonium sulfate (AS) with methylglyoxal (MG) using cavity ring-down spectroscopy (CRDS) at 403 nm wavelength. We have measured the optical constants of BrC SOA from the AS/MG reaction as a function of reaction time. Under dry flow conditions, we observed no apparent variation in the BrC refractive index with aging over the course of 22 days. The retrieved BrC optical constants are similar to those of AS with n = 1.52 for the real component. Despite significant UV absorption observed from the bulk BrC solution, the imaginary index value at 403 nm is below our minimum detection limit which puts an upper bound of k as 0.03. These observations are in agreement with results from our recent studies of the light scattering properties of this BrC aerosol.

  2. Temporal Occurrence and Niche Preferences of Phytophthora spp. Causing Brown Rot of Citrus in the Central Valley of California.

    Science.gov (United States)

    Hao, Wei; Miles, Timothy D; Martin, Frank N; Browne, Gregory T; Förster, Helga; Adaskaveg, James E

    2018-03-01

    Brown rot of citrus fruit is caused by several species of Phytophthora and is currently of serious concern for the California citrus industry. Two species, Phytophthora syringae and P. hibernalis, are quarantine pathogens in China, a major export market for California citrus. To maintain trade and estimate the risk of exporting a quarantine pathogen, the distribution and frequency of Phytophthora spp. causing brown rot of orange in major growing areas of California was investigated. Symptomatic fruit were collected from navel (winter to late spring) and Valencia (late spring to summer) orange orchards from 2013 to 2015. Species identification of isolates was based on morphological characteristics, random amplified polymorphic DNA banding patterns, and sequencing of the internal transcribed spacer and the partial cox2/spacer/cox1 regions from axenic cultures, or directly on DNA from fruit tissue using a multiplex TaqMan quantitative polymerase chain reaction assay. In winter samplings, the incidence of P. syringae based on the number of fruit with Phytophthora spp. detection ranged from 73.6 to 96.1% for the two counties surveyed. The remaining isolates were identified as P. citrophthora. In late spring or summer, only P. citrophthora was recovered. P. hibernalis and P. nicotianae were not detected in any fruit with brown rot symptoms. These results indicate that P. syringae is currently an important brown rot pathogen of citrus fruit in California during the cooler seasons of the year. In winter 2016 and 2017, P. syringae was recovered by pear baiting at a high incidence from leaf litter and from a small number of rhizosphere soil or root samples but not from living leaves on the tree. In contrast, P. citrophthora was rarely found in leaf litter but was commonly detected in the rhizosphere. Thus, leaf litter is a major inoculum source for P. syringae and this species occupies a distinct ecological niche.

  3. Identification of anti-inflammatory effects of extract of brown algae Padina sp. in mice (Mus musculus: A pilot study

    Directory of Open Access Journals (Sweden)

    Dwi Fitrah Ariani Bahar

    2016-06-01

    Full Text Available Infection, tissue damage, or interference immune response are factors that cause inflasmmatory reactions of teeth and surrounding tissues. To reduce the side effects of pharmaceutical drugs, it is necessary to research which uses the principle of back to nature as a source of medicines. One of the natural ingredients that have anti-inflammatory activity is brown algae Padina sp. containing polysaccharides, PUFA, and fucoxanthin. The purpose of this research is to determine antiinflammatory effects of extract brown algae Padina sp. in mice. The research design is pretest and post test with control group design. Sample were 15 male mice weighing 14-35g. Mice were divided into three treatment groups (n=5. G1 (negative control NaCMC 1%, G2 (positive control sodium diclofenac 0.35mg/35g B/V, and G3 was extracted with methanol and Padina sp. dose 7mg/35g B/V. After 30 minutes of testing material was injected, peptone 1% (0.05ml is injected at subplantar area of mice left paw. Measurements were taken using plethysmometer. Data was analysis using repeated ANOVA test. The results showed that volume inflammation of the extract brown algae Padina sp. on V0=0.170ml, V1=0.164 ml, V2=0.120ml, V3=0.108ml, V4=0.138ml, respectively. Repeated ANOVA test obtained P value (<.05 in the Padina sp. group. In conclusion, extract brown algae Padina sp. has anti-inflammatory effects in mice.

  4. Brown v. Board of Education and School Desegregation: An Analysis of Selected Litigation

    OpenAIRE

    Brown, Lynn T.

    2004-01-01

    BROWN V. BOARD OF EDUCATION AND SCHOOL DESEGREGATION: AN ANALYSIS OF SELECTED LITIGATION Lynn T. Brown (ABSTRACT) Brown is often regarded among the most monumental decisions ever rendered by the United States Supreme Court. Its legacy includes a body of case law affecting the shape and meaning of school desegregation over the past fifty years. However, school desegregation and the transition of Brown from courtroom jurisprudence to a manifestation of equal educational opport...

  5. Study on evaluation of gamma oryzanol of germinated brown rice by near infrared spectroscopy

    OpenAIRE

    Kannapot Kaewsorn; Panmanas Sirisomboon

    2014-01-01

    Germinated brown rice (GBR) is rich in gamma oryzanol which increase its consumption popularity, particularly in the health food market. The objective of this research was to apply the near infrared spectroscopy (NIRS) for evaluation of gamma oryzanol of the germinated brown rice. The germinated brown rice samples were prepared from germinated rough rice (soaked for 24 and 48 h, incubated for 0, 6, 12, 18, 24, 30 and 36 h) and purchased from local supermarkets. The germinated brown rice sampl...

  6. Brown Boveri moves to fourth generation MSRs [moisture separator reheaters

    International Nuclear Information System (INIS)

    Boeckh, P. von

    1987-01-01

    The fourth, space saving, generation of moisture separator reheaters from Brown Boveri and Cie (BBC) consists of two types of high velocity moisture separators, 'Mops' and 'Scrups', and the small size reheater, 'Road' . The design of the unit is described, together with operational experience. (author)

  7. PICTORIAL ESSAY Traumatic Brown-Sequard syndrome– clinico ...

    African Journals Online (AJOL)

    A 34-year-old man presented with a history of a stab wound to the left side of the neck. Physical examination revealed an ipsilateral left-sided hemiplegia and contralateral loss of sensation. A clinical diagnosis of. Brown-Sequard syndrome was made. Magnetic resonance imaging. (MRI) findings demonstrated ...

  8. Considerations on the etiology of congenital Brown syndrome.

    Science.gov (United States)

    Coussens, Tracey; Ellis, Forrest J

    2015-07-01

    Brown syndrome is an ocular motility disorder characterized by limited volitional and passive elevation of the eye in adduction. Although originally thought due to abnormalities in the trochlea or tendon sheath (limiting the free movement of the tendon through the trochlea), recent evidence suggests that some cases of congenital Brown syndrome may be related to neurodevelopmental abnormalities of the extraocular muscles (congenital cranial dysinnervation disorders, CCDD). CCDD is a term encompassing congenital abnormalities of eye movements caused by congenital innervational abnormalities. The abnormal development of cranial nerve nuclei or abnormalities in cranial nerve axonal transport affects the development of the extraocular muscle(s). Currently, congenital fibrosis of the extraocular muscles, Duane syndrome, Moebius syndrome, Horizontal gaze palsy and progressive scoliosis, and synergistic divergence are included as CCDDs. In addition, congenial ptosis, Jaw Wink ptosis, and congenital superior oblique palsy are also included. Recently, it has been suggested that some cases of congenital Brown syndrome and congenital superior oblique paresis are related, and these entities may be part of the CCDDs spectrum. Important findings regarding the cause of congenital Brown syndrome will be reviewed.

  9. Bearing the Burden of Desegregation. Black Principals and "Brown"

    Science.gov (United States)

    Karpinski, Carol

    2006-01-01

    "Brown" had a tragic consequence: the displacement, dismissal, and demotion of thousands of African American educators, in particular principals, in the South. Although the lack of diversity in today's teaching force has multiple origins, a reexamination of one of its roots deepens our understanding of the past, illuminates the present,…

  10. Characterisation of bacterial brown spot pathogen from dry bean ...

    African Journals Online (AJOL)

    Pseudomonas syringae pv. syringae (Pss) causes bacterial brown spot (BBS) of beans (Phaseolus vulgaris L.), with yield losses of up to 55% in South Africa. Pss has a wide host range and for many of these, the pathogen has been biochemically and genetically characterised. However, few studies have been conducted on ...

  11. Discovery of a nearby young brown dwarf binary candidate

    Science.gov (United States)

    Reiners, A.; Seifahrt, A.; Dreizler, S.

    2010-04-01

    In near-infrared NaCo observations of the young brown dwarf 2MASS J0041353-562112, we discovered a companion a little less than a magnitude fainter than the primary. The binary candidate has a separation of 143 mas, and the spectral types of the two components are M 6.5 and M 9.0. Colors and flux ratios of the components are consistent with their locations being at the same distance minimizing the probability of the secondary being a background object. The brown dwarf is known to exhibit Li absorption constraining the age to be younger than ~ 200 Myr, and has been suspected of experiencing ongoing accretion, which implies an age as young as ~ 10 Myr. We estimate distance and orbital parameters of the binary as a function of age. For an age of 10 Myr, the distance to the system is 50 pc, the orbital period is 126 yr, and the masses of the components are ~ 30 and ~ 15 MJup. The binary brown dwarf fills a so far unoccupied region in the parameters mass and age; it is a valuable new benchmark object for brown dwarf atmospheric and evolutionary models. Emmy Noether Fellow.

  12. Cytotoxic hydroazulene diterpenes from the brown alga Cystoseira myrica.

    Science.gov (United States)

    Ayyad, Seif-Eldin N; Abdel-Halim, Osama B; Shier, W Thomas; Hoye, Thomas R

    2003-01-01

    Cytotoxicity-guided fractionation of the alcohol extract of the brown alga, Cystoseira myrica, afforded four new cytotoxic hydroazulene diterpenes, dictyone acetate (2), dictyol F monoacetate (4), isodictytriol monoacetate (6), and cystoseirol monoacetate (8), together with two known cytotoxic hydroazulene diterpenes, pachydictyol A (1) and dictyone (3). The constitution of each isolated compound has been determined on the basis of spectroscopic and chemical evidence.

  13. "Brown" at 62: School Segregation by Race, Poverty and State

    Science.gov (United States)

    Orfield, Gary; Ee, Jongyeon; Frankenberg, Erica; Siegel-Hawley, Genevieve

    2016-01-01

    As the anniversary of "Brown v. Board of Education" decision arrives again without any major initiatives to mitigate spreading and deepening segregation in the nation's schools, the Civil Rights Project adds to a growing national discussion with a research brief drawn from a much broader study of school segregation to be published in…

  14. Phenolic Profile and Antioxidant Activity of Brown and Yellow ...

    African Journals Online (AJOL)

    Tigernuts (yellow, YTG and brown, BTG)) were sorted, washed, dried, milled into powder, phenolics extracted with sodium hydroxide and analyzed with Gas chromatography (GC). The tigernuts contain significant concentration of hydroxybenzoic acids, hydrocinnamic acids and flavonoids. The major phenolic acids in YTG ...

  15. Complete Plastid Genome Sequence of the Brown Alga Undaria pinnatifida.

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    Full Text Available In this study, we fully sequenced the circular plastid genome of a brown alga, Undaria pinnatifida. The genome is 130,383 base pairs (bp in size; it contains a large single-copy (LSC, 76,598 bp and a small single-copy region (SSC, 42,977 bp, separated by two inverted repeats (IRa and IRb: 5,404 bp. The genome contains 139 protein-coding, 28 tRNA, and 6 rRNA genes; none of these genes contains introns. Organization and gene contents of the U. pinnatifida plastid genome were similar to those of Saccharina japonica. There is a co-linear relationship between the plastid genome of U. pinnatifida and that of three previously sequenced large brown algal species. Phylogenetic analyses of 43 taxa based on 23 plastid protein-coding genes grouped all plastids into a red or green lineage. In the large brown algae branch, U. pinnatifida and S. japonica formed a sister clade with much closer relationship to Ectocarpus siliculosus than to Fucus vesiculosus. For the first time, the start codon ATT was identified in the plastid genome of large brown algae, in the atpA gene of U. pinnatifida. In addition, we found a gene-length change induced by a 3-bp repetitive DNA in ycf35 and ilvB genes of the U. pinnatifida plastid genome.

  16. New records of brown algae (Phaeophyta) from the Azores.

    OpenAIRE

    Parente, Manuela I.; Fletcher, Robert L.; Neto, Ana I.

    2000-01-01

    Copyright © 2000 Kluwer Academic Publishers. Printed in the Netherlands. The following five species of microscopic tuft-forming/encrusting brown algae (Phaeophyta) are newly recorded for the Island of São Miguel (Azores): Nemoderma tingitana Schousboe ex Bornet. Pseudolithoderma roscoffense Loiseaux (Lithodermataceae), Hecatonema terminalis (Kutzing) Kylin (Punctariaceae), Compsonema saxicolum (Kuckuck) Kuckuck, and Microspongium gelatinosum Reinke (Scytosiphonaceae). The species are descr...

  17. Antioxidant and anti-browning activities of Mentha suaveolens extracts

    African Journals Online (AJOL)

    The chemical analysis of the phenol extract using the high performance liquid chromatography (HPLC) suggests that the rosmarinic acid could explain the observed inhibition. In conclusion, these data suggest that the M. suaveolens compounds can act as preservatives of food against oxidation and enzymatic browning.

  18. Jim Crow's Children: The Broken Promise of the Brown Decision.

    Science.gov (United States)

    Irons, Peter

    This book explores the 150-year struggle against segregated education, showing how victory over segregation was gained, then lost. It provides court testimonials from 1849, through the victory of NAACP lawyers in Brown v. Board of Education, to the erosion of that decision in recent Supreme Court rulings. The story reveals that this long battle…

  19. The Mechanism of White and Brown Adipocyte Differentiation

    Directory of Open Access Journals (Sweden)

    Hironori Nakagami

    2013-04-01

    Full Text Available Obesity gives vent to many diseases such as type 2 diabetes, hypertension, and hyperlipidemia, being considered as the main causes of mortality and morbidity worldwide. The pathogenesis and pathophysiology of metabolic syndrome can well be understood by studying the molecular mechanisms that control the development and function of adipose tissue. In human body, exist two types of adipose tissue, the white and the brown one, which are reported to play various roles in energy homeostasis. The major and most efficient storage of energy occurs in the form of triglycerides in white adipose tissue while brown adipose tissue actively participates in both basal and inducible energy consumption in the form of thermogenesis. Recent years have observed a rapid and greater interest towards developmental plasticity and therapeutic potential of stromal cells those isolated from adipose tissue. The adipocyte differentiation involves a couple of regulators in the white or brown adipogenesis. Peroxisome proliferators-activated receptor-γ actively participates in regulating carbohydrate and lipid metabolism, and also acts as main regulator of both white and brown adipogenesis. This review based on our recent research, seeks to highlight the adipocyte differentiation.

  20. Participatory mapping in Browns Canyon National Monument, Colorado (USA)

    Science.gov (United States)

    John Harner; Lee Cerveny; Rebecca Gronewold

    2017-01-01

    Natural resource managers need up-to-date information about how people interact with public lands and the meanings these places hold for use in planning and decision-making. This case study explains the use of public participatory Geographic Information System (GIS) to generate and analyze spatial patterns of the uses and values people hold for the Browns Canyon...

  1. Morphometric Study of Musanga cecropioides R. Brown and ...

    African Journals Online (AJOL)

    Morphometric or Numerical taxonomic analysis of 56 quantitative and qualitative characters, obtained from Musanga cecropioides R. Brown and five species of Myrianthus, M. arboreus Palisot de Beauvois, M. holstii Engler, M. libericus Rendle, M. preusii Engler and M. serratus (Trecul) Bentham was carried out by ...

  2. A Commentary: "Brown v. Board of Education I: A Reconsideration"

    Science.gov (United States)

    Outlaw, Lucius T., Jr.

    2004-01-01

    This article, a reconsidering of both the benefits and the consequences of the Brown v. Board of Education (1954; Davis and Graham, 1995) case, posits determinations as to the historical significance of the U.S. Supreme Court justices' decision. Carefully weighing the words of the justices renders a position that the decision of the Court and the…

  3. Public School Administration and "Brown v. Board of Education"

    Science.gov (United States)

    Hunter, Richard C.

    2009-01-01

    This article reviews educational initiatives of state and federal government that were designed to remedy the effects of racial segregation on Black public school students in the United States after the famous "Brown v. Board of Education" decisions. Several policy and legal initiatives are reviewed, including school desegregation,…

  4. Pyrolysis of brown coals of the Lelchitsy deposit

    Science.gov (United States)

    Lishtvan, I. I.; Falyushin, P. L.; Kraiko, V. M.; Dudarchik, V. M.

    2012-11-01

    Results of experimental studies on pyrolysis of brown coals of the Lelchitsy deposit, which were conducted on Laboratory setups in stationary and moving layers for producing high-caloric energy carriers, are presented. The yield of the pyrolysis products is determined; the chemical composition of solid, liquid, and gaseous products of thermochemical treatment is considered.

  5. User-Centered Design in Practice: The Brown University Experience

    Science.gov (United States)

    Bordac, Sarah; Rainwater, Jean

    2008-01-01

    This article presents a case study in user-centered design that explores the needs and preferences of undergraduate users. An analysis of LibQual+ and other user surveys, interviews with public service staff, and a formal American with Disabilities Act accessibility review served as the basis for planning a redesign of the Brown University…

  6. Neuroradiologic findings in brown snake envenomation: Computed tomography demonstration

    International Nuclear Information System (INIS)

    Midyett, F.A.

    1998-01-01

    A case of fatal brown snake (Pseudonaja textilis) envenomation is presented. The CT examinations show rapid development and progression of atypical bilateral intracerebral haematomas (ICH) which produce a fatal outcome despite correction of the underlying coagulopathy. The striking CT appearance suggests coagulopathy and is predictive of increased mortality. Copyright (1998) Blackwell Science Pty Ltd

  7. Screening and characterization a RAPD marker of tobacco brown ...

    African Journals Online (AJOL)

    RAPD) methods were used to analyze F2 individuals of 82-3041 × Yunyan 84 to screen and characterize the molecular marker linked to brown-spot resistant gene. A total of 800 arbitrary decamer oligonucleotide primers were used for RAPD ...

  8. Screening lowland rice varieties for resistance to brown spot ...

    African Journals Online (AJOL)

    PAT

    Twelve lowland rice varieties (BG 90-2, Cisadane, FARO 12, FARO 15 (early maturing), FARO 15 (late maturing), IR 5, ITA 123, ITA 306, MAS 2401, Suakoko 8 and TOS 2578) were planted in 2008 and 2009 growing seasons in Enyong creek rice field in Akwa Ibom State. The varieties were screened for resistance to brown ...

  9. Social vocalizations of big brown bats vary with behavioral context.

    Directory of Open Access Journals (Sweden)

    Marie A Gadziola

    Full Text Available Bats are among the most gregarious and vocal mammals, with some species demonstrating a diverse repertoire of syllables under a variety of behavioral contexts. Despite extensive characterization of big brown bat (Eptesicus fuscus biosonar signals, there have been no detailed studies of adult social vocalizations. We recorded and analyzed social vocalizations and associated behaviors of captive big brown bats under four behavioral contexts: low aggression, medium aggression, high aggression, and appeasement. Even limited to these contexts, big brown bats possess a rich repertoire of social vocalizations, with 18 distinct syllable types automatically classified using a spectrogram cross-correlation procedure. For each behavioral context, we describe vocalizations in terms of syllable acoustics, temporal emission patterns, and typical syllable sequences. Emotion-related acoustic cues are evident within the call structure by context-specific syllable types or variations in the temporal emission pattern. We designed a paradigm that could evoke aggressive vocalizations while monitoring heart rate as an objective measure of internal physiological state. Changes in the magnitude and duration of elevated heart rate scaled to the level of evoked aggression, confirming the behavioral state classifications assessed by vocalizations and behavioral displays. These results reveal a complex acoustic communication system among big brown bats in which acoustic cues and call structure signal the emotional state of a caller.

  10. Vacancy clusters, dislocations and brown colouration in diamond.

    Science.gov (United States)

    Bangert, U; Barnes, R; Gass, M H; Bleloch, A L; Godfrey, I S

    2009-09-09

    Following on from the idea that clusters of vacancies are the origin of the featureless absorption and brown colouration in natural diamond, dislocations are shown to exhibit sub-bandgap absorption also. The vacancy cluster idea has arisen from theoretical predictions of π-bonded chains reconstructing the cluster surfaces and has been confirmed by energy loss studies. In contrast, bandgap states at dislocations are observed in brown and colourless diamonds alike, giving rise to weak absorption, which resembles that theoretically predicted from shuffle dislocation segments. This, however, would not account for the degrees of brownness in the diamonds, but it suggests that if such shuffle segments exist, vacancies must have been present and moved to dislocations to create these configurations in the first place. The question arises, what happens to the vast number of vacancy clusters upon high pressure high temperature (HPHT) annealing, which renders the diamonds colourless. Our observations on natural brown diamonds after HPHT treatment suggest that vacancy clusters, trapped in the strain fields of dislocations, grow in size accompanied by a decrease in their numbers; this leads to much reduced optical absorption.

  11. Short Note DNA sequences from the Little Brown Bustard Eupodotis ...

    African Journals Online (AJOL)

    Taxonomic classification of birds based exclusively on morphology and plumage traits has often been found to be inconsistent with true evolutionary history when tested with molecular phylogenies based on neutrally evolving markers. Here we present cytochrome-b gene sequences for the poorly known Little Brown ...

  12. Parent–offspring recognition in the Brown-headed Parrot ...

    African Journals Online (AJOL)

    Recognition by vocal characteristics between parents and their offspring is thought to be ubiquitous in colonially nesting avian species. The Brown-headed Parrot Poicephalus cryptoxanthus nests in hollows in trees. However, when the chicks fledge they leave the nest and for the following three weeks spend their time in a ...

  13. William Faulkner: No Friend of Brown v. Board of Education.

    Science.gov (United States)

    Polsgrove, Carol

    2001-01-01

    In the years following the Supreme Court's Brown v. Board of Education decision to integrate America's public schools, William Faulkner, Norman Mailer, Hannah Arendt, Robert Penn Warren, and, to a lesser extent, C. Vann Woodward, provided intellectual sustenance to southern efforts to resist racial integration. Focuses on Faulkner's political…

  14. Social organization of the golden brown mouse lemur (Microcebus ravelobensis)

    NARCIS (Netherlands)

    Weidt, A.; Hagenah, N.; Randrianambinina, B.; Radespiel, U.

    2004-01-01

    Our study provides the first data on the social organization of the golden brown mouse lemur, a nocturnal primate discovered in northwestern Madagascar in 1994. The study was carried out in two 6-month field periods during the dry season, covering time before and during the mating season. The

  15. Hyperparathyroidism with presumed sellar-parasellar brown tumour ...

    African Journals Online (AJOL)

    Brown tumours are an end-stage complication of hyperparathyroidism. They are relatively rare today, due to earlier diagnosis and prompt treatment of hyperparathyroidism. Common locations are the mandible, pelvis, ribs and long bones of the axial skeleton.2 The skull base is an extremely rare site and, for obvious ...

  16. Primary hyperparathyroidism with rare presentation as multiple brown tumours

    Directory of Open Access Journals (Sweden)

    Smit Doshi

    2012-04-01

    Full Text Available We present a case of primary hyperparathyroidism with an uncommon presentation as multiple brown tumours, which may easily be mistaken for a primary bone neoplasm. A brief literature review and its clinical and surgical management are also discussed here.

  17. A case of multiple brown tumors with primary hyperparathyroidism.

    Science.gov (United States)

    Mori, Hiroko; Okada, Yosuke; Arao, Tadashi; Shimaziri, Shohei; Tanaka, Yoshiya

    2013-01-01

    We report a case of large multiple brown tumors in a patient with primary hyperparathyroidism. A 52-year-old woman suffered from pain in the ribs and developed left facial swelling and deformity. CT showed a large destructive osteolytic lesion in the left maxillary sinus. Biopsy showed a lesion with newly formed bone tissue, diffuse giant cells and deposits of hemosiderin. In addition, similar lesions were also observed in the ribs, iliac bones and pelvis. The laboratory data showed hypercalcemia and hyperparathyroidism. Cervical echo and (201)Tl-(99m)TcO(4-) scintigraphy demonstrated a right lower swollen parathyroid adenoma. The diagnosis was multiple brown tumors with primary hyperparathyroidism and parathyroidectomy was performed. Follow-up CT showed marked decreases in the size of osteolytic lesions with calcification in the brown tumors compared to pre-treatment findings. These changes were associated with marked improvement in pain and facial deformity. We described a rare case of multiple brown tumors appeared in the maxilla associated with primary hyperparathyroidism.

  18. Germination conditions affect physicochemical properties of germinated brown rice flour.

    Science.gov (United States)

    Charoenthaikij, Phantipha; Jangchud, Kamolwan; Jangchud, Anuvat; Piyachomkwan, Kuakoon; Tungtrakul, Patcharee; Prinyawiwatkul, Witoon

    2009-01-01

    Germinated brown rice has been reported to be nutritious due to increased free gamma-aminobutyric acid (GABA). The physicochemical properties of brown rice (BR) and glutinous brown rice (GNBR) after germination as affected by different steeping times (24, 36, 48, and 72 h depending on the rice variety) and pHs of steeping water (3, 5, 7, and as-is) were determined and compared to those of the nongerminated one (control). As the steeping time increased or pH of steeping water decreased, germinated brown rice flours (GBRF) from both BR and GNBR had greater reducing sugar, free GABA and alpha-amylase activity; while the total starch and viscosity were lower than their respective controls. GBRFs from both BR and GNBR prepared after 24-h steeping time at pH 3 contained a high content of free GABA at 32.70 and 30.69 mg/100 g flour, respectively. The peak viscosity of GBRF obtained from both BR and GNBR (7.42 to 228.22 and 4.42 to 58.67 RVU, respectively) was significantly lower than that of their controls (255.46 and 190.17 RVU, respectively). The principal component analysis indicated that the important variables for discriminating among GBRFs, explained by the first 2 components at 89.82% of total explained variance, were the pasting profiles, alpha-amylase activity, and free GABA.

  19. Enzymatic oxalic acid regulation correlated with wood degradation in four brown-rot fungi

    Science.gov (United States)

    Anne Christine Steenkjær Hastrup; Frederick Green III; Patricia K. Lebow; Bo Jensen

    2012-01-01

    Oxalic acid is a key component in the initiation of brown-rot decay and it has been suggested that it plays multiple roles during the degradation process. Oxalic acid is accumulated to varying degrees among brown-rot fungi; however, details on active regulation are scarce. The accumulation of oxalic acid was measured in this study from wood degraded by the four brown-...

  20. 'n Kritiese evaluasie van Colin Brown se studie: Miracles and the ...

    African Journals Online (AJOL)

    A critical evaluation of Colin Brown's study: Miracles and the critical mind. As a historical survey of the viewpoints regarding miracles throughout the ages. Miracles and the critical mind of Colin Brown can be highly recommended as a reference work. In this lies its value. Brown has an interesting viewpoint. He states that ...

  1. File list: Oth.Adp.20.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Adp.20.AllAg.Brown_adipocytes mm9 TFs and others Adipocyte Brown adipocytes SRX...RX978689,SRX800015,SRX800014,SRX800018,SRX800019 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Adp.20.AllAg.Brown_adipocytes.bed ...

  2. File list: Oth.Adp.50.AllAg.Brown_preadipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Adp.50.AllAg.Brown_preadipocytes mm9 TFs and others Adipocyte Brown preadipocyt...341028,SRX341760,SRX341767,SRX341763,SRX341027 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Adp.50.AllAg.Brown_preadipocytes.bed ...

  3. Justice Deferred A Half Century After Brown v. Board of Education

    Science.gov (United States)

    Pettigrew, Thomas F.

    2004-01-01

    The road to Brown v. Board of Education (1954) was a slow and circuitous climb, whereas the retreat down from Brown has been swift and direct. This article reviews 4 distinct U.S. Supreme Court eras of racial decisions: the segregation, preparatory, desegregation, and resegregation eras. It notes both the strengths and weaknesses of Brown and…

  4. The Scientific Attack on Brown v. Board of Education, 1954-1964

    Science.gov (United States)

    Jackson, John P.

    2004-01-01

    Psychologists' work was cited in the Supreme Court case of Brown v. Board of Education (1954). One criticism of the citation was that psychology could be used to overturn the Brown decision and return the country to segregation. A historical examination of such an attempt to overturn Brown in the early 1960s on the basis of new psychological…

  5. Order of Argument in the Case Brown v. Board of Education

    Science.gov (United States)

    Chism, Kahlil; Potter, Lee Ann

    2004-01-01

    The Supreme Court's opinion in the 1954 Brown v. Board of Education case legally ended decades of racial segregation in America's public schools. Originally named after Oliver Brown, the first of many plaintiffs listed in the lower court case of Brown v. Board of Education of Topeka, KS, the landmark decision actually resolved five separate…

  6. After Brown U.'s Report on Slavery, Silence (So Far)

    Science.gov (United States)

    Bartlett, Thomas

    2006-01-01

    This article, discusses Brown University's slavery report, a 106-page narrative examination of the early connections between Brown University and slavery, that has been greeted--so far--with silence. The report, done at the behest of Ruth J. Simmons, Brown's president and herself a descendant of slaves, is an unsparing look at a shameful side of…

  7. File list: ALL.Adp.50.AllAg.Brown_adipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Adp.50.AllAg.Brown_adipocytes mm9 All antigens Adipocyte Brown adipocytes SRX80...X800019,SRX185797,SRX478163,SRX478162 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Adp.50.AllAg.Brown_adipocytes.bed ...

  8. File list: His.Adp.50.AllAg.Brown_preadipocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Adp.50.AllAg.Brown_preadipocytes mm9 Histone Adipocyte Brown preadipocytes SRX3...RX341421,SRX341046,SRX478160 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Adp.50.AllAg.Brown_preadipocytes.bed ...

  9. Prying the Gates Wide Open: Academic Freedom and Gender Equality at Brown University, 1974-1977

    Science.gov (United States)

    Porwancher, Andrew

    2013-01-01

    In 1974, Brown University's Department of Anthropology denied tenure to assistant professor Louise Lamphere. Convinced that her dismissal was the product of sex discrimination, Lamphere filed suit against Brown. Lamphere and three other female scholars who joined her suit successfully pressed Brown into an out-of-court settlement in 1977.…

  10. Arctic Tundra Greening and Browning at Circumpolar and Regional Scales

    Science.gov (United States)

    Epstein, H. E.; Bhatt, U. S.; Walker, D. A.; Raynolds, M. K.; Yang, X.

    2017-12-01

    Remote sensing data have historically been used to assess the dynamics of arctic tundra vegetation. Until recently the scientific literature has largely described the "greening" of the Arctic; from a remote sensing perspective, an increase in the Normalized Difference Vegetation Index (NDVI), or a similar satellite-based vegetation index. Vegetation increases have been heterogeneous throughout the Arctic, and were reported to be up to 25% in certain areas over a 30-year timespan. However, more recently, arctic tundra vegetation dynamics have gotten more complex, with observations of more widespread tundra "browning" being reported. We used a combination of remote sensing data, including the Global Inventory Monitoring and Modeling System (GIMMS), as well as higher spatial resolution Landsat data, to evaluate the spatio-temporal patterns of arctic tundra vegetation dynamics (greening and browning) at circumpolar and regional scales over the past 3-4 decades. At the circumpolar scale, we focus on the spatial heterogeneity (by tundra subzone and continent) of tundra browning over the past 5-15 years, followed by a more recent recovery (greening since 2015). Landsat time series allow us to evaluate the landscape-scale heterogeneity of tundra greening and browning for northern Alaska and the Yamal Peninsula in northwestern Siberia, Russia. Multi-dataset analyses reveal that tundra greening and browning (i.e. increases or decreases in the NDVI respectively) are generated by different sets of processes. Tundra greening is largely a result of either climate warming, lengthening of the growing season, or responses to disturbances, such as fires, landslides, and freeze-thaw processes. Browning on the other hand tends to be more event-driven, such as the shorter-term decline in vegetation due to fire, insect defoliation, consumption by larger herbivores, or extreme weather events (e.g. winter warming or early summer frost damage). Browning can also be caused by local or

  11. Database for content of mercury in Polish brown coal

    Science.gov (United States)

    Jastrząb, Krzysztof

    2018-01-01

    Poland is rated among the countries with largest level of mercury emission in Europe. According to information provided by the National Centre for Balancing and Management of Emissions (KOBiZE) more than 10.5 tons of mercury and its compounds were emitted into the atmosphere in 2015 from the area of Poland. Within the scope of the BazaHg project lasting from 2014 to 2015 and co-financed from the National Centre of Research and Development (NCBiR) a database was set up with specification of mercury content in Polish hard steam coal, coking coal and brown coal (lignite) grades. With regard to domestic brown coal the database comprises information on coal grades from Brown Coal Mines of `Bełchatów', `Adamów', `Turów' and `Sieniawa'. Currently the database contains 130 records with parameters of brown coal, where each record stands for technical analysis (content of moisture, ash and volatile particles), elemental analysis (CHNS), content of chlorine and mercury as well as net calorific value and combustion heat. Content of mercury in samples of brown coal grades under test ranged from 44 to 985 μg of Hg/kg with the average level of 345 μg of Hg/kg. The established database makes up a reliable and trustworthy source of information about content of mercury in Polish fossils. The foregoing details completed with information about consumption of coal by individual electric power stations and multiplied by appropriate emission coefficients may serve as the background to establish loads of mercury emitted into atmosphere from individual stations and by the entire sector of power engineering in total. It will also enable Polish central organizations and individual business entities to implement reasonable policy with respect of mercury emission into atmosphere.

  12. Development trends in the Lusatian brown coal mining industry

    International Nuclear Information System (INIS)

    Schwirten, D.

    1994-01-01

    Lusatia has lived on and with brown coal for over 200 years. Brown coal changed what was once a region in which forestry and agriculture predominated into an industrial region. Thanks to its good combustion properties and high energy yield brown coal very soon became known and popular. It was always the driving force for a rapid development which resulted in an economically sound and technically up-to-date industry in Lusatia. This powerful status of brown coal was however soon exploited for aims which were bound to lead to the downfall of two social structures (during the years from 1933 to 1990) by reason of a regime of unconditional autarchy. The economic and technical development thus initiated certainly brought many advantages, but it also had serious diadvantages. Constant increases in production, as a result of which planned rated outputs were intentionally disregarded, were the rule because production targets had to be met or exceeded. Economic inefficiency led to a scarcity of labour and a shortage of finances. Environmental aims had no priority since production was the absolute, primary objective. Consequently, this regime of economic autarchy ended in an one-way street as far as industry was concerned, a situation which was accompanied by an unexampled destruction of the natural basic living conditions and direct, threatening health hazards to man and nature. The year 1990 saw the beginning of the transition from planned controlled economy to free market economy. The reorganization of the former large combines as corporations was not however merely a formal change, but internally also represented a transformation. The brown coal mining industry manifested its new intention and determination to be economically competitive and unsubsidized in future, to operate in such a way as to be compatible with the environment and to exploit reserves carefully, as well as to render its activities socially compatible. (orig.) [de

  13. Sperm cryopreservation in brown bear (Ursus arctos): preliminary aspects.

    Science.gov (United States)

    Anel, L; Alvarez, M; Martínez-Pastor, F; Gomes, S; Nicolás, M; Mata, M; Martínez, A F; Borragán, S; Anel, E; de Paz, P

    2008-10-01

    The development of sperm cryopreservation procedures in brown bear is the basis for establishing a specific genetic resource bank aimed at the preservation of a Cantabric brown bear population, which is seriously threatened. Several issues complicate the development of these cryopreservation procedures: lack of previous specific studies, a high incidence of urospermia and spermagglutination observed in bear ejaculates. Moreover, the availability of individuals for research from these threatened populations is problematic. In the case of the Cantabric brown bear, we have used males from other populations, but of the same species, as surrogates, to carry out a direct extrapolation of the results. Urospermia-- Moreover, 70% of the ejaculates are urine contaminated and spermagglutination have a detrimental effect on post-thawing cell quality recovery in this species. Considering the high value of these samples (autochthonous population with few individuals), a pre-selection of the ejaculates is not a viable alternative. Preventive methods reducing the mentioned detrimental effects need to be developed. On the basis of previous data, we can suppose that bear spermatozoa resist freezing injuries well. Nevertheless, because of the scarcity of this information, it is necessary to conduct further research on bear semen freezing under field conditions. Epidydimal spermatozoa can be important for genetic resource banking of threatened populations and thus specific cryobiological protocols need to be assayed. To date, 168 brown bear ejaculates have been frozen by the ITRA-ULE group at the University of León (Spain) in the development of methodologies for the preservation of brown bear sperm.

  14. Effects of Sodium Chloride, Potassium Chloride and Calcium Chloride on the Formation of α-Dicarbonyl Compounds, Furfurals and Development of Browning in Cookies during Baking.

    Science.gov (United States)

    Kocadağlı, Tolgahan; Gökmen, Vural

    2016-10-02

    Effect of NaCl, KCl, CaCl2, NaHCO3, and NH4HCO3 on the formation of glucosone, 1-deoxyglucosone, 3-deoxyglucosone, glyoxal, methylglyoxal, diacetyl, 5-hydroxymethyl-2-furfural, 2-furfural and browning were investigated in cookies. Presence of 1.5% NaCl, 1% KCl, and 1% CaCl2 on flour basis had no effect on α-dicarbonyl compounds, except 1-deoxyglucosone increased in the presence of KCl and CaCl2. The increase in 5-hydroxymethyl-2-furfural formation in the presence of NaCl, KCl, and CaCl2 did not relate to 3-deoxyglucosone formation and pH changes. NaCl, KCl, and CaCl2 increased browning in cookies. Model reaction systems indicated that NaCl, KCl, and CaCl2 enhance browning by increasing furfurals in caramelization. NaCl, KCl, and CaCl2 decreased browning intensity in heated glucose-glycine system. Usage of CaCl2 in cookies may considerably increase furfurals but not α-dicarbonyl compounds. Sodium reduction can be obtained by replacement with potassium without sacrificing the desired consequences of caramelization in sugar rich bakeries.

  15. Evaluation of browning ratio in an image analysis of apple slices at different stages of instant controlled pressure drop-assisted hot-air drying (AD-DIC).

    Science.gov (United States)

    Gao, Kun; Zhou, Linyan; Bi, Jinfeng; Yi, Jianyong; Wu, Xinye; Zhou, Mo; Wang, Xueyuan; Liu, Xuan

    2017-06-01

    Computer vision-based image analysis systems are widely used in food processing to evaluate quality changes. They are able to objectively measure the surface colour of various products since, providing some obvious advantages with their objectivity and quantitative capabilities. In this study, a computer vision-based image analysis system was used to investigate the colour changes of apple slices dried by instant controlled pressure drop-assisted hot air drying (AD-DIC). The CIE L* value and polyphenol oxidase activity in apple slices decreased during the entire drying process, whereas other colour indexes, including CIE a*, b*, ΔE and C* values, increased. The browning ratio calculated by image analysis increased during the drying process, and a sharp increment was observed for the DIC process. The change in 5-hydroxymethylfurfural (5-HMF) and fluorescent compounds (FIC) showed the same trend with browning ratio due to Maillard reaction. Moreover, the concentrations of 5-HMF and FIC both had a good quadratic correlation (R 2  > 0.998) with the browning ratio. Browning ratio was a reliable indicator of 5-HMF and FIC changes in apple slices during drying. The image analysis system could be used to monitor colour changes, 5-HMF and FIC in dehydrated apple slices during the AD-DIC process. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  16. miRNA-32 Drives Brown Fat Thermogenesis and Trans-activates Subcutaneous White Fat Browning in Mice

    Directory of Open Access Journals (Sweden)

    Raymond Ng

    2017-05-01

    Full Text Available Brown adipose tissue (BAT activation and subcutaneous white fat browning are essential components of the thermogenic response to cold stimulus in mammals. microRNAs have been shown to regulate both processes in cis. Here, we identify miR-32 as a BAT-specific super-enhancer-associated miRNA in mice that is selectively expressed in BAT and further upregulated during cold exposure. Inhibiting miR-32 in vivo led to impaired cold tolerance, decreased BAT thermogenesis, and compromised white fat browning as a result of reduced serum FGF21 levels. Further examination showed that miR-32 directly represses its target gene Tob1, thereby activating p38 MAP kinase signaling to drive FGF21 expression and secretion from BAT. BAT-specific miR-32 overexpression led to increased BAT thermogenesis and serum FGF21 levels, which further promotes white fat browning in trans. Our results suggested miR-32 and Tob1 as modulators of FGF21 signaling that can be manipulated for therapeutic benefit against obesity and metabolic syndrome.

  17. The emergence of cold-induced brown adipocytes in mouse white fat depots is determined predominantly by white to brown adipocyte transdifferentiation

    DEFF Research Database (Denmark)

    Barbatelli, G.; Murano, I.; Madsen, Lise

    2010-01-01

    The origin of brown adipocytes arising in white adipose tissue (WAT) after cold acclimatization is unclear. Here, we demonstrate that several UCP1-immunoreactive brown adipocytes occurring in WAT after cold acclimatization have a mixed morphology (paucilocular adipocytes). These cells also had...... for C/EBP (an antimitotic protein), whereas Ccna1 expression (related to cell proliferation) was unchanged. Overall, our data strongly suggest that the cold-induced emergence of brown adipocytes in WAT predominantly reflects ß3-adrenoceptor-mediated transdifferentiation....

  18. [Multiple brown tumors in a female hemodialyzed patient with severe secondary hyperparathyroidism].

    Science.gov (United States)

    Peces, R; Gil, F; González, F; Ablanedo, P

    2002-01-01

    Skeletal brown tumours are relatively uncommon, and brown tumours that involve multiple bones are considered very rare. We describe a 29-year-old woman with chronic renal failure (CRF) who had undergone hemodialysis for 21 years and developed multiple brown tumours associated with severe secondary hyperparathyroidism. Computed tomography (CT) revealed multiple brown tumours involving scapula, ribs, spine and sacroiliac bone. Microscopic analysis of the brown tumour showed dense infiltration of the marrow space by reactive fibroblastic tissue with irregularly distributed multinucleated osteoclastic giants cells and marked increase in hematopoietic elements.

  19. Data set for extraction and transesterification of bio-oil fromStoechospermum marginatum, a brown marine algae.

    Science.gov (United States)

    Venkatesan, Hariram; Godwin, John J; Sivamani, Seralathan

    2017-10-01

    The article presents the experimental data on the extraction and transesterification of bio-oil derived from Stoechospermum marginatum, a brown macro marine algae. The samples were collected from Mandapam region, Gulf of Mannar, Tamil Nadu, India. The bio-oil was extracted using Soxhlet technique with a lipid extraction efficiency of 24.4%. Single stage transesterification was adopted due to lower free fatty acid content. The yield of biodiesel was optimized by varying the process parameters. The obtained data showed the optimum process parameters as reaction time 90 min, reaction temperature 65 °C, catalyst concentration 0.50 g and 8:1 M ratio. Furthermore, the data pertaining to the physio-chemical properties of the derived algal biodiesel were also presented.

  20. Data set for extraction and transesterification of bio-oil from Stoechospermum marginatum, a brown marine algae

    Directory of Open Access Journals (Sweden)

    Hariram Venkatesan

    2017-10-01

    Full Text Available The article presents the experimental data on the extraction and transesterification of bio-oil derived from Stoechospermum marginatum, a brown macro marine algae. The samples were collected from Mandapam region, Gulf of Mannar, Tamil Nadu, India. The bio-oil was extracted using Soxhlet technique with a lipid extraction efficiency of 24.4%. Single stage transesterification was adopted due to lower free fatty acid content. The yield of biodiesel was optimized by varying the process parameters. The obtained data showed the optimum process parameters as reaction time 90 min, reaction temperature 65 °C, catalyst concentration 0.50 g and 8:1 M ratio. Furthermore, the data pertaining to the physio-chemical properties of the derived algal biodiesel were also presented.

  1. Desulfurization and oxidation behavior of ultra-fine CaO particles prepared from brown coal; Kattan wo mochiite choseishita CaO chobiryushi no datsuryu tokusei to sanka tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin, G.; Roman, M.; Yamazaki, Y.; Abe, H.; Harano, Y.; Takarada, Y. [Gunma University, Gunma (Japan). Faculty of Engineering

    1996-10-28

    The effect of reaction temperature and oxygen concentration on the desulfurization and oxidation behavior of ion-exchanged brown coal by Ca as new desulfurizing agent was studied. In experiment, Yallourn coal was used for ion- exchange, and limestone produced in Tochigi prefecture was also used for comparative study. Ca-exchanged brown coal was prepared by agitating coal in Ca(OH)2 slurry for 24 hours. The desulfurization behavior of a desulfurizing agent was obtained by measuring H2S and sulfur compounds in outlet gas of a reactor, and the oxidation behavior by measuring SO2 emission in outlet gas after oxidation reaction. As the experimental result, CaO produced from Ca-exchanged brown coal offered the extremely high activity to desulfurization reaction in a temperature range of 850-950{degree}C as compared with limestone. Although the oxidation behavior was dependent on oxidation temperature and oxygen concentration, CaS obtained from Ca-exchanged brown coal was more rapidly converted to CaSO4 than limestone. 3 refs., 8 figs., 2 tabs.

  2. Catalysis of Photochemical Reactions.

    Science.gov (United States)

    Albini, A.

    1986-01-01

    Offers a classification system of catalytic effects in photochemical reactions, contrasting characteristic properties of photochemical and thermal reactions. Discusses catalysis and sensitization, examples of catalyzed reactions of excepted states, complexing ground state substrates, and catalysis of primary photoproducts. (JM)

  3. On Thermonuclear Reaction Rates

    OpenAIRE

    Haubold, H. J.; Mathai, A. M.

    1996-01-01

    Nuclear reactions govern major aspects of the chemical evolution of galaxies and stars. Analytic study of the reaction rates and reaction probability integrals is attempted here. Exact expressions for the reaction rates and reaction probability integrals for nuclear reactions in the cases of nonresonant, modified nonresonant, screened nonresonant and resonant cases are given. These are expressed in terms of H-functions, G-functions and in computable series forms. Computational aspects are als...

  4. Enzymatic decolourisation of Methyl Orange and Bismarck Brown using crude peroxidase from Armoracia rusticana

    Science.gov (United States)

    Ambatkar, Mugdha; Mukundan, Usha

    2015-12-01

    The decolourisation of Methyl Orange (MO) and Bismarck Brown (BB) by crude peroxidase from Armoracia rusticana (Horseradish) was studied by varying different reaction parameters. The pH of the reaction mixture, initial dye concentration, amount of enzyme and hydrogen peroxide concentration were optimised for ambient temperatures (30 ± 2 °C). The optimum pH for decolourisation was 4.0 (72.95 %) and 3.0 (79.24 %) for MO and BB, respectively. Also it was found that the Chemical Oxygen Demand of the enzyme-treated sample was significantly lower than that of the untreated controls for both dyes. The addition of a complex iron salt like Ferric EDTA was found to enhance the decolourisation of both dyes at pH 6.0, showing an increase of 8.69 % and 14.17 % in the decolourisation of MO and of BB, respectively. The present study explores the potential of crude peroxidase from horseradish to decolourise representative monoazo and diazo dyes, MO and BB, respectively. An attempt has been made to utilise a crude enzyme with appreciable activity obtained after minimal processing for the decolourisation of the aforesaid dyes. The findings of this study would find application in the enzymatic treatment of wastewater containing azo dyes.

  5. Surprisingly small HONO emissions from snow surfaces at Browning Pass, Antarctica

    Directory of Open Access Journals (Sweden)

    H. J. Beine

    2006-01-01

    Full Text Available Measured Fluxes of nitrous acid at Browning Pass, Antarctica were very low, despite conditions that are generally understood as favorable for HONO emissions, including: acidic snow surfaces, an abundance of NO3- anions in the snow surface, and abundant UV light for NO3- photolysis. Photochemical modeling suggests noon time HONO fluxes of 5–10 nmol m-2 h-1; the measured fluxes, however, were close to zero throughout the campaign. The location and state of NO3- in snow is crucial to its reactivity. The analysis of soluble mineral ions in snow reveals that the NO3- ion is probably present in aged snows as NaNO3. This is peculiar to our study site, and we suggest that this may affect the photochemical reactivity of NO3-, by preventing the release of products, or providing a reactive medium for newly formed HONO. In fresh snow, the NO3- ion is probably present as dissolved or adsorbed HNO3 and yet, no HONO emissions were observed. We speculate that HONO formation from NO3- photolysis may involve electron transfer reactions of NO2 from photosensitized organics and that fresh snows at our site had insufficient concentrations of adequate organic compounds to favor this reaction.

  6. Fatal snake bite in a brown bear (Ursus arctos L.: A case report

    Directory of Open Access Journals (Sweden)

    Romel Velev

    2015-03-01

    Full Text Available Poisoning from snake venom in animals is an emergency which requires immediate attention or otherwise, the delayed and inadequate treatment leads to untoward consequences and death. The present paper describes a case of venomous snakebite in a brown bear cub (Ursus arctos L. and its therapeutic management. The brown bear cub of which was found alone on the slopes of a mountain in the southwest part of the country was presented to the peripheral veterinary practice in Ohrid with a history of dullness, disorientation and excessive swelling around the left forepaw. It was diagnosed for snakebite based on the history and physical examination. The hematological parameters showed reduced values of hemoglobin, packed cell volume and increased total leukocyte count. The biochemical values showed elevated levels of alanine aminotransferase and creatinine. After immobilization of the animal, the treatment was conducted with fluids, corticosteroid and broad spectrum antibiotic with careful monitoring. Despite the treatment which was initiated immediately, it was only partially effective, and the animal died one hour after the beginning of its course. Poisonous snakes are common in the mountainous part of Macedonia and, just like humans, wild bears especially their cubs are susceptible to the deadly venom of some species. The severity of the reaction to snake venom and prognosis in animals depends on a number of factors: on the type and species of snake, on how much venom was injected, on the location of the bite, on the age, health and body weight of the animal and crucially, the time interval between the snakebite and the application of the treatment.

  7. Brown queer compositionistas and the reflective practice of automythnography.

    Science.gov (United States)

    Inayatulla, Shereen

    2017-10-02

    Autoethnographic self-reflection is a strategy for teachers to examine their pedagogies and academic workspaces at large. In the process of moving from teaching composition at an institution in the Midwest to one in Southeast Queens, this author describes significant shifts in how she perceived herself as a Brown queer pedagogue. In order to analyze these shifts in ways that advance her pedagogical praxis, the author evaluates the research tools available to her and offers a hybrid method for reflection, which she calls "vulnerable automythnography." Applying this reflective practice to a specific classroom occurrence, the author considers some ways in which vulnerable automythnography offers underrepresented teachers and students an opportunity to examine the aggressions Black, Brown, and queer bodies face in academic settings. She posits this method of reflection as a tool for savvy resistance and intervention.

  8. Brown's TRANSPORT up to third order aberration by artificial intelligence

    International Nuclear Information System (INIS)

    Xia Jiawen; Xie Xi; Qiao Qingwen

    1991-01-01

    Brown's TRANSPORT is a first and second order matrix multiplication computer program intended for the design of accelerator beam transport systems, neglecting the third order aberration. Recently a new method was developed to derive analytically any order aberration coefficients of general charged particle optic system, applicable to any practical systems, such as accelerators, electron microscopes, lithographs, etc., including those unknown systems yet to be invented. An artificial intelligence program in Turbo Prolog was implemented on IBM-PC 286 or 386 machine to generate automatically the analytical expression of any order aberration coefficients of general charged particle optic system. Based on this new method and technique, Brown's TRANSPORT is extended beyond the second order aberration effects by artificial intelligence, outputing automatically all the analytical expressions up to the third order aberration coefficients

  9. Associationism without associative links: Thomas Brown and the associationist project.

    Science.gov (United States)

    Dacey, Mike

    2015-12-01

    There are two roles that association played in 18th-19th century associationism. The first dominates modern understanding of the history of the concept: association is a causal link posited to explain why ideas come in the sequence they do. The second has been ignored: association is merely regularity in the trains of thought, and the target of explanation. The view of association as regularity arose in several forms throughout the tradition, but Thomas Brown (1778-1820) makes the distinction explicit. He argues that there is no associative link, and association is mere sequence. I trace this view of association through the tradition, and consider its implications: Brown's views, in particular, motivate a rethinking of the associationist tradition in psychology. Associationism was a project united by a shared explanandum phenomenon, rather than a theory united by a shared theoretical posit. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. A role of active brown adipose tissue in cancer cachexia?

    Directory of Open Access Journals (Sweden)

    Emiel Beijer

    2012-06-01

    Full Text Available Until a few years ago, adult humans were not thought to have brown adipose tissue (BAT. Now, this is a rapidly evolving field of research with perspectives in metabolic syndromes such as obesity and new therapies targeting its bio-energetic pathways. White, brown and socalled brite adipose fat seem to be able to trans-differentiate into each other, emphasizing the dynamic nature of fat tissue for metabolism. Human and animal data in cancer cachexia to date provide some evidence for BAT activation, but its quantitative impact on energy expenditure and weight loss is controversial. Prospective clinical studies can address the potential role of BAT in cancer cachexia using 18F-fluorodeoxyglucose positron emission tomography-computed tomography scanning, with careful consideration of co-factors such as diet, exposure to the cold, physical activity and body mass index, that all seem to act on BAT recruitment and activity.

  11. Characterizing Water Ice Clouds on the Coldest Known Brown Dwarf

    Science.gov (United States)

    Luhman, Kevin; Burgasser, Adam; Cushing, Michael; Esplin, Taran; Fortney, Jonathan; Hardegree-Ullman, Kevin; Marley, Mark; Morley, Caroline; Schneider, Adam; Trucks, Jesica

    2014-12-01

    We have conducted a search for high proper motion brown dwarfs using multi-epoch all-sky mid-infrared images from the WISE satellite. Through this work, we have discovered an object with a parallactic distance of 2.3 pc and a temperature of 250 K, making it the 4th closest neighbor of the Sun, and the coldest known brown dwarf. Because of its extreme proximity and temperature, it represents an unparalleled laboratory for studying planet-like atmospheres in an unexplored temperature regime. We propose to photometrically monitor this object with IRAC to 1) detect and characterize water ice clouds in its atmosphere via the short-term variations induced during rotation and 2) constrain the long-term evolution of its clouds across a period of months.

  12. [Comparative chemical composition of the Barents Sea brown algae].

    Science.gov (United States)

    Obluchinskaia, E D

    2008-01-01

    Comparative study of phytochemical compositions of the most widespread brown algae species (one laminarian and four fucoid algae) from Barents Sea has been performed. A modified technique for mannitol determination in brown algae is proposed. It was revealed that fucus algae (fam. Fucaceae) contain 3% (of total dry weight) less mannitol than laminaria (Laminaria saccharina). The contents of alginic acid and laminaran in the Barents Sea fucoids are more than 10% less compared to laminaria. The alga L. saccharina contains almost two times more iodine than the species of fam. Fucaceae. The amounts of fucoidan and sum lipids in the Barents Sea fucoid algae is higher than in Laminaria saccharina (4-7% and 1-3%, respectively). In terms of contents of main biologically active compounds, fucus and laminarian algae from Barents Sea are inferior to none of the Far-Eastern species. The Barents Sea algae may become an important source of biologically active compounds.

  13. Feasibility of observing Hanbury Brown and Twiss phase

    Science.gov (United States)

    Wentz, Tina; Saha, Prasenjit

    2015-01-01

    The interferometers of Hanbury Brown and collaborators in the 1950s and 1960s, and their modern descendants now being developed (intensity interferometers) measure the spatial power spectrum of the source from intensity correlations at two points. The quantum optical theory of the Hanbury Brown and Twiss effect shows that more is possible, in particular the phase information can be recovered by correlating intensities at three points (bispectrum). In this paper we argue that such three-point measurements are possible for bright stars such as Sirius and Betelgeuse using off the shelf single photon counters with collecting areas of the order of 100 m2. It seems possible to map individual features on the stellar surface. Simple diameter measurements would be possible with amateur class telescopes.

  14. Crafting identities and accessing opportunities post-Brown.

    Science.gov (United States)

    Spencer, Margaret Beale

    2005-11-01

    Decades following Brown v. Board of Education (1954), issues regarding the effects of skin color, poverty, and racial differences in the availability of protective factors persist. For a multiethnic sample of mainly African American (56%), female (69%), and high-achieving (65%) youths, a dual-axis model of vulnerability is used to compare four groups of youths identified as high, masked, low, and undetermined vulnerability on the basis of the presence of risk and protective factors. Risks included level of poverty, number of parents in home, and skin-color pigmentation. Protective factors included youths' perceptions of school climate, parental monitoring, and consonance between skin pigmentation and preferred skin color. The author suggests that 50 years post-Brown, issues concerning White privilege, color stereotyping, power discrepancies, and economic disparities maintain "invisible" and persistent hurdles for vulnerable youths who vary on available protective factors. Findings confirm the impact of vulnerability on psychosocial and achievement outcomes. Copyright (c) 2005 APA, all rights reserved.

  15. Multiple brown tumors of the jaws in primary hyperparathyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoung A; Koh, Kwang Joon [School of Dentisity, Chonbuk National University, Jeonju (Korea, Republic of)

    2010-09-15

    Brown tumor is usually diagnosed at the terminal stage of hyperparathyroidism. Diagnosis of this tumor is confirmed by endocrinologic investigations along with clinical and radiographic examination. Radiographical differential diagnosis of this tumor includes central giant cell granuloma, aneurysmal bone cyst, metastatic tumor, multiple myeloma, and Paget disease. This report presents a rare case of multiple brown tumors occurring at the maxilla and mandible, which was initially misdiagnosed as central giant cell granuloma. Plain radiographs demonstrated multiple well-defined multilocular radiolucency. CT images showed soft tissue mass with low attenuated lesions, perforation of the lingual cortical plate, and a heterogeneous mass at the right thyroid lobe. These findings were consistent with parathyroid adenoma. The patient had hypercalcemia, hypophosphatemia, and elevated alkaline phosphatase level. Surgical excision of the tumor was performed. No recurrence was observed during a 28-month follow-up.

  16. Oxidative stress and partial migration in brown trout (Salmo trutta)

    DEFF Research Database (Denmark)

    Birnie-Gauvin, Kim; Peiman, K. S.; Larsen, Martin Hage

    2017-01-01

    During migration, animals are typically limited by their endogenous energetic resources which must be allocated to the physiological costs associated with locomotion, as well as avoiding and/or compensating for oxidative stress. To date, there have been few attempts to understand the role...... oxidative stress and migration. Using the brown trout, we obtained blood samples from juveniles from a coastal stream in Denmark in the fall prior to peak seaward migration which occurs in the spring, and assayed for antioxidant capacity (oxygen radical absorbance capacity) and oxidative stress levels...... of oxidative status in migration biology, particularly in fish. Semi-anadromous brown trout (Salmo trutta, Linnaeus 1758) exhibit partial migration, where some individuals smoltify and migrate to sea, and others become stream residents, providing us with an excellent model to investigate the link between...

  17. A systematic search for brown dwarfs orbiting nearby stars

    International Nuclear Information System (INIS)

    Henry, T.J.; Mccarthy, D.W. Jr.

    1990-01-01

    Survey data for brown dwarf and stellar companions relative to known M dwarf stars within 5 pc north of -30 deg are analyzed. A region 0.2 to 5 arcsec in radius around 27 stars at the IR H and K bands are examined using IR speckle interferometry. The frequency of binary versus single M dwarfs in the solar neighborhood is examined. The IR mass-magnitude relations and mass-luminosity-age relation are studied. The data reveal that there are 19 single M dwarfs, 8 M dwarf binaries, 1 M dwarf triple system, and 1 M dwarf in a triple system for M dwarfs within 5 pc north of -30 deg. Also of the 27 M dwarfs studied none was found to have a brown dwarf companion. 64 refs

  18. Bridging the Gap on Tight Separation Brown Dwarf Binaries

    Science.gov (United States)

    Bardalez Gagliuffi, Daniella C.; Burgasser, Adam J.; Gelino, Christopher R.; Melis, Carl; Blake, Cullen

    2015-01-01

    Multiplicity is a key statistic for understanding the formation of very low mass (VLM) stars and brown dwarfs. Currently, the separation distribution of VLM binaries remains poorly constrained at small separations (candidates from a library of 738 spectra from the SpeX Prism Spectral Libraries. We present twelve new binary candidates, confirm two previously reported candidates and rule out other two previously reported candidates. All of our candidates have primary and secondary spectral types between M7-L7 and L8-T8 respectively. We find that blue L dwarfs and subdwarfs are contaminants in our sample and propose a method for segregating these sources. If confirmed by follow-up observations, these systems may potentially add to the growing list of tight separation binaries, giving further insight into brown dwarf formation scenarios.

  19. [Secondary hyperparathyroidism and multiple vertebral brown tumors: cure after parathyroidectomy].

    Science.gov (United States)

    Kharrat, M; Turc Baron, C; Djamali, A; Delmas, S; Lopez, S; Deschodt, G; Mourad, G

    1997-01-01

    A 46 year old man was referred for severe left cruralgia and multiple vertebral cystic defects on CT-scan. He was treated by hemodialysis since 1987 for chronic renal failure secondary to focal and segmental glomerulosclerosis, diagnosed in 1960 on renal biopsy. Dialysis schedule consisted of 3 x 4 h/week with a polysulfone dialyser and 1.75 mMol Ca containing bicarbonate dialysate. On early 1995, the patient complained of back pain and cruralgia, which gradually worsened. Vertebral column CT-scan and MRI showed multiple lytic lesions expanding into the medullary canal. Biological hyperparathyroidism was present. To differentiate between hyperparathyroidism with brown tumors, malignancy and amyloid deposition, an iliac biopsy and a biopsy of a corporeal vertebral cyst were done. They showed florid hyperparathyroidism and brown tumors. The patient was submitted to surgical parathyroidectomy. Six months after surgery, cruralgia resumed, CT-scan and MRI showed refilling of the cysts by calcic material.

  20. Cervical disc herniation manifesting as a Brown-Sequard syndrome

    Directory of Open Access Journals (Sweden)

    Kunio Yokoyama

    2012-01-01

    Full Text Available Brown-Sequard syndrome is commonly seen in the setting of spinal trauma or an extramedullary spinal neoplasm. The clinical picture reflects hemisection of the spinal cord. We report a rare case of Brown-Sequard syndrome caused by a large cervical herniated disc. A 63-year-old man presented with progressive right hemiparesis and disruption of pain and temperature sensation on the left side of the body. Magnetic resonance imaging showed large C3-C4 disc herniation compressing the spinal cord at that level, with severe canal stenosis from C4 through C7. Decompressive cervical laminoplasty was performed. After surgery, complete sensory function was restored and a marked improvement in motor power was obtained.