Investigating the Stability Mechanism of Water-in-Diluted Bitumen Emulsions through Isolation and Characterization of the Stabilizing Materials at the Interface

2003 ◽  
Vol 17 (1) ◽  
pp. 179-190 ◽  
Author(s):  
X. Wu
2006 ◽  
Vol 20 (2) ◽  
pp. 673-681 ◽  
Author(s):  
Guoxing Gu ◽  
Liyan Zhang ◽  
Xin A. Wu ◽  
Zhenghe Xu ◽  
Jacob Masliyah

2019 ◽  
Vol 8 (1) ◽  
pp. 12-18
Author(s):  
Malathi Mangalanathan ◽  
Tamiloli Devendhiran ◽  
Saraswathi Uthamaramasamy ◽  
Keerthika Kumarasamy ◽  
K Mohanraj ◽  
...  

Mitochondrial and lysosomal membranes are prominent membranes of cardiac cells and are the factors that determine membrane function in myocardial ischemia. In this study, isolation of mitochondria and lysosome from heart tissue under the control, isoproterenol (ISO) (8.5mg/100g) induced cardiotoxic rats and oral pretreatment with Z. armatum fruit (200, 400mg/kg body weight) treated rats. Further characterization of marker enzymes was done. A decreased in the activity of all the mitochondrial and lysosomal marker enzymes in ISO administered cardiotoxic rats when compared to control rats which indicate ISO decreased the stability of the membrane. Pretreatment with hydroethanolic extract of Z. armatum fruit to ISO induced rats significantly reverted these biochemical alterations near to normal. The possible mechanism for the protection of heart mitochondria and lysosome against oxidative damage induced by ISO might be due to quenching of free radicals and enhancing the action of marker enzymes.


2016 ◽  
Vol 77 (1) ◽  
Author(s):  
. TRI-PANJI ◽  
. SUHARYANTO ◽  
Marini WIJAYANTI

AbstractSpirulina platensis is a blue-green microalgawhich is frequently used for food and feedsupplements and cosmetic active agent. Thismicroalga also produces a strong antioxidantnamely superoxide dismutase (SOD) used ascosmetic active agent for anti aging and anti freeradicals. SOD was isolated from S. platensis cellbiomass from local isolate grown on latex serumon semipilot (3.5 m 3 ) and pilot scale (40 m 3 )then dried with spray drying or sun drying andcharacterized. SOD was purified with sequentialtwo-stage sedimentation using ammoniumsulphate and fractionated in chromatographiccolumn containing Sephadex G 200. Thefractions were analysed to determine the activity,cofactor metal and amino acid composition of theantioxidant. The results showed thatsedimentation of SOD extract with 80%ammonium sulphate produced SOD with higheractivity compared to that of SOD fromcommercial S. platensis biomass. This SOD wassuccessfully isolated and purified. MetaloenzymeSOD was composed of subunits with molecularweight of 77.78; 71.74; and 19.2 kDa, whichcontained nine types of amino acids with tyrosineand lysine as the major amino acid components.Zn was the most predominant metal on SOD, thenfollowed by Fe and Mn. The main subunitcofactors consisted of Zn 72%, Fe 25%, Mn 2%,and Cu 1%, which were different from thesmall subunit that contained of Zn 55%, Mn 31%,Fe 14%, and Cu 4%. The stability of SOD wasachieved on pH 7.5 and temperature below 25 o C.AbstrakSpirulina platensis adalah mikroalga hijaubiru yang banyak digunakan sebagai suplemenpangan, pakan, dan bahan aktif kosmetika.Mikroalga ini juga menghasilkan antioksidankuat yaitu superoksida dismutase (SOD), yangmerupakan bahan aktif kosmetika anti penuaandini dan pencegah efek radikal bebas. SODdiisolasi dari biomassa sel S. platensis isolat lokalyang dibiakkan dalam serum lateks skalasemipilot (3,5 m 3 ) dan pilot (40 m 3 ) sertadikeringkan dengan cara pengeringan kabut(spray drying) atau penjemuran untuk kemudiandikarakterisasi. SOD dimurnikan dengan peng-endapan bertingkat menggunakan ammoniumsulfat dan dipisahkan dengan kolom kromatografiberisi Sephadex G 200. Hasil pemisahankemudian dianalisis untuk menentukan aktivitas,logam kofaktor serta komposisi asam amino antioksidan tersebut. Hasil penelitian menunjukkanbahwa pengendapan ekstrak SOD denganSOD lebih tinggi dari SOD asal biomassaS. platensis komersial. SOD tersebut telahberhasil diisolasi dan dimurnikan. MetaloenzimSOD tersusun atas subunit dengan BM 77,78;71,74; dan 19,2 kDa, yang mengandungsembilan jenis asam amino dengan tirosin danlisin sebagai komponen asam amino utama.Logam yang dominan pada SOD adalah Zn,disusul kemudian Fe dan Mn. Kofaktor sub unitbesar terdiri dari Zn 72%, Fe 25%, Mn 2%, danCu 1%, berbeda dengan sub unit kecil yangmengandung Zn 55%, Mn 31%, Fe 14%, dan Cu4%. Stabilitas SOD S. platensis dicapai pada pH7,5 dan suhu di bawah 25 o Cammonium sulfat 80% menghasilkan aktivitas


2016 ◽  
Vol 77 (1) ◽  
Author(s):  
. TRI-PANJI ◽  
. SUHARYANTO ◽  
Marini WIJAYANTI

AbstractSpirulina platensis is a blue-green microalgawhich is frequently used for food and feedsupplements and cosmetic active agent. Thismicroalga also produces a strong antioxidantnamely superoxide dismutase (SOD) used ascosmetic active agent for anti aging and anti freeradicals. SOD was isolated from S. platensis cellbiomass from local isolate grown on latex serumon semipilot (3.5 m 3 ) and pilot scale (40 m 3 )then dried with spray drying or sun drying andcharacterized. SOD was purified with sequentialtwo-stage sedimentation using ammoniumsulphate and fractionated in chromatographiccolumn containing Sephadex G 200. Thefractions were analysed to determine the activity,cofactor metal and amino acid composition of theantioxidant. The results showed thatsedimentation of SOD extract with 80%ammonium sulphate produced SOD with higheractivity compared to that of SOD fromcommercial S. platensis biomass. This SOD wassuccessfully isolated and purified. MetaloenzymeSOD was composed of subunits with molecularweight of 77.78; 71.74; and 19.2 kDa, whichcontained nine types of amino acids with tyrosineand lysine as the major amino acid components.Zn was the most predominant metal on SOD, thenfollowed by Fe and Mn. The main subunitcofactors consisted of Zn 72%, Fe 25%, Mn 2%,and Cu 1%, which were different from thesmall subunit that contained of Zn 55%, Mn 31%,Fe 14%, and Cu 4%. The stability of SOD wasachieved on pH 7.5 and temperature below 25 o C.AbstrakSpirulina platensis adalah mikroalga hijaubiru yang banyak digunakan sebagai suplemenpangan, pakan, dan bahan aktif kosmetika.Mikroalga ini juga menghasilkan antioksidankuat yaitu superoksida dismutase (SOD), yangmerupakan bahan aktif kosmetika anti penuaandini dan pencegah efek radikal bebas. SODdiisolasi dari biomassa sel S. platensis isolat lokalyang dibiakkan dalam serum lateks skalasemipilot (3,5 m 3 ) dan pilot (40 m 3 ) sertadikeringkan dengan cara pengeringan kabut(spray drying) atau penjemuran untuk kemudiandikarakterisasi. SOD dimurnikan dengan peng-endapan bertingkat menggunakan ammoniumsulfat dan dipisahkan dengan kolom kromatografiberisi Sephadex G 200. Hasil pemisahankemudian dianalisis untuk menentukan aktivitas,logam kofaktor serta komposisi asam amino antioksidan tersebut. Hasil penelitian menunjukkanbahwa pengendapan ekstrak SOD denganSOD lebih tinggi dari SOD asal biomassaS. platensis komersial. SOD tersebut telahberhasil diisolasi dan dimurnikan. MetaloenzimSOD tersusun atas subunit dengan BM 77,78;71,74; dan 19,2 kDa, yang mengandungsembilan jenis asam amino dengan tirosin danlisin sebagai komponen asam amino utama.Logam yang dominan pada SOD adalah Zn,disusul kemudian Fe dan Mn. Kofaktor sub unitbesar terdiri dari Zn 72%, Fe 25%, Mn 2%, danCu 1%, berbeda dengan sub unit kecil yangmengandung Zn 55%, Mn 31%, Fe 14%, dan Cu4%. Stabilitas SOD S. platensis dicapai pada pH7,5 dan suhu di bawah 25 o Cammonium sulfat 80% menghasilkan aktivitas


1980 ◽  
Vol 35 (9-10) ◽  
pp. 696-698 ◽  
Author(s):  
B. Schöbel ◽  
W. Pollmann

Abstract The characteristic features of an acetic acid esters hydrolyzing enzyme (acetylesterase, EC 3.1.1.16) are described. The pH- and temperature optimum were 7.0 and 40 °C respectively. The stability of the enzyme regarding different pH- and temperature conditions was investigated. The molecular weight of the acetylesterase could be determined to 160000. A small acetic ester hydrolyzing activity was found too with a molecular weight of about 25000. The activity was not inhibited by addition of di-isopropylphosphorofluoridate (DFP) or physostigmine. The KM-value for glyceryl triacetate was about 90 mM. Concentration of the enzyme was done by ultrafiltration and column-chromatography. The enzymatic activity tests were performed titrimetrically using glyceryl triacetate for substrate.


1983 ◽  
Vol 48 (6) ◽  
pp. 1552-1557
Author(s):  
Jana Podlahová ◽  
Jaroslav Podlaha

The anions of ethylenediphosphinetetraacetic acid are hydrolyzed in aqueous solutions at 80 °C in the two following reactions: ((OOCCH2)2PCH2CH2P(CH2COO)2)4- → (OOCCH2(O)HPCH2CH2PH(O)CH2COO)2- → (O(O)HPCH2CH2PH(O)O)2-. Both reactions are acid and base catalyzed so that, at pH < 12, the first reaction is much faster than the second. The reaction course was studied by 1H NMR spectroscopy and by isolation and characterization of the products. The effect of both reactions on the stability of solutions of ethylenediphosphinetetraacetic acid and their salts is negligible at laboratory temperature.


Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.


2000 ◽  
Vol 31 (2) ◽  
pp. 149-149 ◽  
Author(s):  
T Tozaki ◽  
H Kakoi ◽  
S Mashima ◽  
K Hirota ◽  
T Hasegawa ◽  
...  

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