scholarly journals The oxidation of reduced nicotinamide nucleotides by hydrogen peroxide in the presence of lactoperoxidase and thiocyanate, iodide or bromide

1970 ◽  
Vol 117 (4) ◽  
pp. 791-797 ◽  
Author(s):  
D. McC. Hogg ◽  
G. R. Jago
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidation Product ◽  
Chemical Properties ◽  
Oxidation Reactions ◽  
Significant Extent ◽  
And Chemical Properties

Lactoperoxidase (EC 1.11.1.7) catalysed the oxidation of NADH by hydrogen peroxide in the presence of either thiocyanate, iodide or bromide. In the presence of thiocyanate, net oxidation of thiocyanate occurred simultaneously with the oxidation of NADH, but in the presence of iodide or bromide, only the oxidation of NADH occurred to a significant extent. In the presence of thiocyanate or bromide, NADH was oxidized to NAD+ but in the presence of iodide, an oxidation product with spectral and chemical properties distinct from NAD+ was formed. Thiocyanate, iodide and bromide appeared to function in the oxidation of NADH by themselves being oxidized to products which in turn oxidized NADH, rather than by activating the enzyme. Iodine, which oxidized NADH non-enzymically, appeared to be an intermediate in the oxidation of NADH in the presence of iodide. NADPH was oxidized similarly under the same conditions. An assessment was made of the rates of these oxidation reactions, together with the rates of other lactoperoxidase-catalysed reactions, at physiological concentrations of thiocyanate, iodide and bromide. The results indicated that in milk and saliva the oxidation of thiocyanate to a bacterial inhibitor was likely to predominate over the oxidation of NADH.

scholarly journals The Effects of Hydrogen Peroxide on Plant Growth, Mineral Accumulation, as Well as Biological and Chemical Properties of Ficus deltoidea

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 599 ◽  
Author(s):  
Nik Nurnaeimah ◽  
Nashriyah Mat ◽  
Khamsah Suryati Mohd ◽  
Noor Afiza Badaluddin ◽  
Nornasuha Yusoff ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Antioxidant Activity ◽  
Chemical Properties ◽  
The Other ◽  
Mineral Nutrient ◽  
Flavonoid Content ◽  
Ficus Deltoidea ◽  
Other Hand ◽  
Mineral Accumulation ◽  
And Chemical Properties

Hydrogen peroxide (H2O2) is defined as a reactive oxygen species (ROS), able to cause damage to a variety of cellular structures. On the other hand, recent work has demonstrated that H2O2 can also act as a potent signaling molecule that mediates various physiological and biochemical processes in plants. This study was carried out to investigate the effects of H2O2 on the growth, mineral nutrient accumulation, as well as the biologic and chemical properties of Ficus deltoidea var. deltoidea. F. deltoidea plants were spray-treated with 0- (control), 8-, 16-, 30- and 60-mM H2O2 under field conditions. Plant height, leaf area, chlorophyll content, net photosynthetic rate, stomatal conductance and quantum yield of the F. deltoidea plants significantly increased after treatment with 16 and 30-mM H2O2. The results indicate that 60-mM H2O2 increased the accumulation of arsenic, iron and sodium content in the leaves of F. deltoidea. On the other hand, 8-mM H2O2 significantly enhanced the accumulation of arsenic, iron, calcium and potassium content in the syconium of F. deltoidea plants. In addition, H2O2 treatment did not produce any significant effects on antimony and magnesium accumulation in the leaves or the syconium of F. deltoidea plants. The results show that the F. deltoidea plant has strong antidiabetic properties and its α-glucosidase activity increased in treated plants compared to standard acarbose. Hydrogen peroxide, particularly in concentrations of 16 and 30 mM, increased the antioxidant activity, total phenolic and flavonoid content and the vitexin and isovitexin content. There was a positive correlation between antioxidant activity with total phenol and total flavonoid content in H2O2-treated plants. The quantitative analysis by HPTLC indicates that the amount of vitexin and isovitexin increased with the higher concentrations of H2O2. From this study, it can be concluded that spraying 16 and 30-mM H2O2 once a week enhances growth, mineral accumulation and stimulates bioactive compounds of the F. deltoidea plants.

Sulfoxydes et sulfones hétérobicycliques dérivés de l'α-thioglycérol. 2,8-Dioxa-6-oxo-6-thiabicyclo[3.2.1]octanes et 2,8-dioxa-6,6′-dioxo-6-thiabicyclo[3.2.1]octanes

1983 ◽  
Vol 61 (9) ◽  
pp. 2095-2102 ◽  
Author(s):  
Pierre Calinaud ◽  
Jacques Gelas
Keyword(s):  
Chemical Properties ◽  
Oxidation Reactions ◽  
Tert Butyl ◽  
And Chemical Properties

The oxidation reactions of heterobicyclic sulfides derived from α-thioglycerol (alkyl-2,8-dioxa-6-thiabicyclo[3.2.1]octanes), leading to sulfoxides and the corresponding sulfones, have been studied. The stereochemistry of the oxidation as a function of the reagent used (H2O2, meta-chloroperbenzoic acid, and tert-butyl hypochlorite) has been examined. Structural assignments of the sulfoxides arise from the spectroscopic and chemical properties of these compounds. [Journal translation]

scholarly journals Application of Enzyme for Bleaching of Wheat Straw AQ-Soda Pulp

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Ghafoor A ◽  
Cheema K. J. ◽  
Yaqoob N. ◽  
Rehman I.Ur- ◽  
Said A
Keyword(s):  
Hydrogen Peroxide ◽  
Wheat Straw ◽  
Paper Industry ◽  
Chemical Properties ◽  
Elemental Chlorine ◽  
Metal Contents ◽  
Soda Pulp ◽  
Physical And Chemical ◽  
Toxic Load ◽  
And Chemical Properties

Pulp and paper industry is one of the major contributors to environmental pollution due to its toxic and carcinogenic discharges during its various processes e.g., chlorinated bleaching of the pulp. Use of alternative bleaching chemicals e.g., enzyme and/or elemental chlorine free (ECF) or total chlorine free (TCF) agents are the best option to reduce the load of carcinogenic chlorinated compounds on our environment. Present study was carried out to highlight the application of enzyme during bleaching of wheat straw anthraquinon (AQ)-soda pulp to considerably reduce the toxic load on the environment. Wheat straw AQ-soda pulp was treated with acid (A) to reduce its metal contents followed by oxygen (O) delignification. Delignified pulp was then subjected to enzymatic (X) treatment with xylanase prior to bleaching to increase the effectiveness of successive bleaching with hydrogen peroxide (P). Handsheets were prepared from the treated pulp after each experimental trial to study its various optical, physical and chemical properties. Brightness of bleached pulp was improved up to ISO 73% with AOXP1P2 bleaching sequence. The improved brightness up to ISO 76% was achieved when alkali extraction stage was incorporated before bleaching with hydrogen peroxide (AOXEP1P2). TDS, COD and BOD5 of effluent samples during different experimental stages was monitored and compared with NEQS. It was evident from the results that enzymatic treatment not only helped to reduce the effluent load but also reduced the consumption of bleaching chemicals to achieve good brightness values.

scholarly journals Pus solvents as new drugs with unique physical and chemical properti

2020 ◽  
Vol 17 (4) ◽  
pp. 89-95
Author(s):  
Alexander L. Urakov
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Bicarbonate ◽  
Detrimental Effect ◽  
Chemical Properties ◽  
Chemical Compounds ◽  
Biological Tissues ◽  
Local Interaction ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

The literature review shows that standards for the treatment of purulent diseases to date include antiseptic and disinfectants, but do not include agents that dilute and/or dissolve thick pus. It is shown that the pharmacodynamics of antiseptic and disinfectants consists in the local disinfecting effect of these agents. With local interaction with the surface of living and non-living tissues, these agents are able to sterilize it. It was found that for disinfection of the selected surfaces, these agents are used in solutions that contain these agents in concentrations that provide a denaturing effect. It is shown that denaturing action of antiseptic and disinfectants is a special case of dependence of local action of solutions of all medicines and chemical compounds on their concentration. The fact is that increasing the concentration of chemical compounds in solutions sooner or later turns that solutions into a liquid medium that is not compatible with life. Therefore, this liquid kills all cells of the micro-and macroworld. That is why the use of solutions with denaturing action provides a detrimental effect on the cells of all microorganisms and cells of the macroorganism. With local interaction with the tissues of the macroorganism, the drugs cause the following pharmacological effects: local sterilizing, irritating (local inflammatory) and cauterizing (necrotic) action. Thus solutions with denaturing concentration of one means increase the hardness, other means do not change the hardness, and the third means decrease the hardness of biological tissues, including purulent masses. From this it is concluded that today in the treatment of purulent diseases are used means, detrimental effect on all forms of life, and not means, unidirectionally acting on purulent masses. At the same time, it is shown that some of the modern antiseptic and disinfectants can change the properties of purulent masses in the right direction and optimize their removal by diluting and dissolving the thick pus. It is established that the leaders in the solvent action on thick and sticky pus are sodium bicarbonate solutions in combination with hydrogen peroxide. It is shown that solutions that effectively dissolve thick pus have special physical and chemical properties: all of them have moderate alkaline, temperature, boiling and osmotic activity. Preparations that most effectively dissolve thick pus and most quickly and completely remove it out of the purulent cavities, additionally contain carbon dioxide gas or oxygen gas under excessive pressure. In chronological order are recipes invented hygiene products with special physical and chemical properties, providing them with the ability to quickly and effectively liquefy, dissolve and remove the thick pus out of the purulent cavities. It is shown that a new group of hygiene products was discovered in Russia and was called Solvents of pus. The most effective and safe solvents of pus are warm (heated to a temperature of 42 C) solutions containing 24% sodium bicarbonate and 0.53% hydrogen peroxide.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

The microstructure of a TiB2/Ti-47 Al composite material

1989 ◽  
Vol 47 ◽  
pp. 674-675
Author(s):  
O. Popoola ◽  
A.H. Heuer ◽  
P. Pirouz
Keyword(s):  
Composite Material ◽  
Ion Beam ◽  
Chemical Properties ◽  
Intermetallic Alloys ◽  
Transmission Electron ◽  
Diamond Polishing ◽  
Al Composite ◽  
The Matrix ◽  
Argon Ion ◽  
And Chemical Properties

The addition of fibres or particles (TiB2, SiC etc.) into TiAl intermetallic alloys could increase their toughness without compromising their good high temperature mechanical and chemical properties. This paper briefly discribes the microstructure developed by a TiAl/TiB2 composite material fabricated with the XD™ process and forged at 960°C.The specimens for transmission electron microscopy (TEM) were prepared in the usual way (i.e. diamond polishing and argon ion beam thinning) and examined on a JEOL 4000EX for microstucture and on a Philips 400T equipped with a SiLi detector for microanalyses.The matrix was predominantly γ (TiAl with L10 structure) and α2(TisAl with DO 19 structure) phases with various morphologies shown in figure 1.

Tailoring microstructures of materials through biomimetics

1993 ◽  
Vol 51 ◽  
pp. 500-501
Author(s):  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Chemical Properties ◽  
Design And Synthesis ◽  
Structure Sensitive ◽  
Macro Scale ◽  
Methods Of Synthesis ◽  
Successive Level ◽  
Engineering Materials ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Synthesis Of Materials

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications.Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging.In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.

On some energetic and chemical properties of the calcite surface

1976 ◽  
Vol 73 ◽  
pp. 351-355 ◽  
Author(s):  
Gilles Goujon ◽  
Boyan Mutaftschiev
Keyword(s):  
Chemical Properties ◽  
And Chemical Properties

KARAKTERISTIK TANAH DAN PERBANDINGAN PRODUKSI KELAPA SAWIT (Elaeis guineensis Jacq.) DENGAN METODE TANAM LUBANG BESAR DAN PARIT DRAINASE 2:1 PADA LAHAN SPODOSOL DI KABUPATEN BARITO TIMUR PROPINSI KALIMANTAN TENGAH - INDONESIA

2015 ◽  
Vol 2 (2) ◽  
pp. 148-158
Author(s):  
Surianto
Keyword(s):  
Soil Texture ◽  
Oil Palm ◽  
Soil Profile ◽  
Chemical Properties ◽  
Exchangeable Cations ◽  
Soil Horizon ◽  
Soil Profiles ◽  
Negative Effect ◽  
Hole Profile ◽  
And Chemical Properties

Spodosol soil of Typic Placorthod sub-group of East Barito District is one of the problem soils with the presence of hardpan layer, low fertility, low water holding capacity, acid reaction and it is not suitable for oil palm cultivation without any properly specific management of land preparation and implemented best agronomic practices. A study was carried out to evaluate the soil characteristic of a big hole (A profile) and no big hole (B profile) system and comparative oil palm productivity among two planting systems. This study was conducted in Spodosol soil at oil palm plantation (coordinate X = 0281843 and Y = 9764116), East Barito District, Central Kalimantan Province on February 2014, by surveying of placic and ortstein depth and observing soil texture and chemical properties of 2 (two) oil palm's soil profiles that have been planted in five years. Big hole system of commercial oil palm field planting on the Spodosol soil area was designed for the specific purpose of minimizing the potential of a negative effect of shallow effective planting depth for oil palms growing due to the hardpan layer (placic and ortstein) presence as deep as 0.25 - 0.50 m. The big hole system is a planting hole type which was vertical-sided with 2.00 m x 1.50 m on top and bottom side and 3.00 m depth meanwhile the 2:1 drain was vertical-sided also with 1.50 m depth and 300 m length. Oil palm production was recorded from the year 2012 up to 2014. Results indicated that the fractions both big hole profile (A profile) and no big hole profile (B profile) were dominated by sands ranged from 60% to 92% and the highest sands content of non-big hole soil profile were found in A and E horizons (92%). Better distribution of sand and clay fractions content in between layers of big hole soil profiles of A profile sample is more uniform compared to the B profile sample. The mechanical holing and material mixing of soil materials of A soil profile among the upper and lower horizons i.e. A, E, B and C horizons before planting that resulted a better distribution of both soil texture (sands and clay) and chemical properties such as acidity value (pH), C-organic, N, C/N ratio, CEC, P-available and Exchangeable Bases. Investigation showed that exchangeable cations (Ca, Mg, K), were very low in soil layers (A profile) and horizons (B profile) investigated. The low exchangeable cations due to highly leached of bases to the lower layers and horizons. Besides, the palm which was planted on the big hole system showed good adaptation and response positively by growing well of tertiary and quaternary roots that the roots were penetrable into deeper rooting zone as much as >1.00 m depth. The roots can grow well and penetrate much deeper in A profile compared to the undisturbed hardpan layer (B profile). The FFB (fresh fruit bunches) production of the non-big hole block was higher than the big hole block for the first three years of production. This might be due to the high variation of monthly rainfall in-between years of observation from 2009 to 2014. Therefore, the hardness of placic and ortstein as unpenetrable agents by roots and water to prevent water loss and retain the water in the rhizosphere especially in the drier weather. In the high rainfall condition, the 2:1 drain to prevent water saturation in the oil palm rhizosphere by moving some water into the drain. Meanwhile, the disturbed soil horizon (big hole area) was drier than un disturbance immediately due to water removal to deeper layers. We concluded that both big hole and 2:1 drain are a suitable technology for Spodosol soil land especially in preparing palms planting to minimize the negative effect of the hardpan layer for oil palm growth.

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