Extraction and characterization of the blue-sensitive visual pigment of the toad Bufo marinus

1987 ◽  
Vol 65 (4) ◽  
pp. 884-887 ◽  
Author(s):  
A. J. Sillman
Keyword(s):  
Vitamin A ◽  
Visual Pigment ◽  
Chemical Properties ◽  
Bufo Marinus ◽  
Physical And Chemical Properties ◽  
Electrophysiological Studies ◽  
Physical And Chemical ◽  
Toad Bufo ◽  
And Chemical Properties

The blue-sensitive visual pigment of the green rods of Bufo marinus was extracted with digitonin. The pigment is present in an amount equal to about 11% that of rhodopsin. It is based on vitamin A1 and exhibits a maximum absorbance of 433 nm. The pigment is labile and readily destroyed by hydroxylamine, regenerates to a much greater degree than does rhodopsin, and is more effectively extracted from the membrane than is rhodopsin. The green rod pigment of Bufo marinus appears to share the same physical and chemical properties as the green rod pigments of other amphibians. Therefore, the results of electrophysiological studies on the green rods of Bufo marinus can be more confidently generalized to other species. The results are discussed in terms of the blue phototaxis that is characteristic of many amphibians.

scholarly journals AVALIAÇÃO DA ESTRUTURA ELETRÔNICA DA FASE MONOCLINICA DO ÓXIDO DE NIÓBIO COM BASE NO USO DE DIFERENTES FUNCIONAIS DE DENSIDADE

Química Nova ◽  
2021 ◽  
Author(s):  
Kamila Ody ◽  
João Jesus ◽  
Carlos Cava ◽  
Anderson Albuquerque ◽  
Ary Maia ◽  
...  
Keyword(s):  
Density Functional ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Density Functionals ◽  
Monoclinic Structure ◽  
Functional Theory ◽  
Periodic Models ◽  
Physical And Chemical ◽  
And Chemical Properties

ASSESSMENT OF THE ELECTRONIC STRUCTURE OF THE MONOCLINIC PHASE OF NIOBIUM OXIDE BASED ON THE USE OF DIFFERENT DENSITY FUNCTIONALS. Niobium oxides, Nb2O5, are considered semiconductor materials with very attractive physical and chemical properties for applications in many areas, such as catalysis, sensors, medical, aerospace, etc. Especially, the characterization of Nb2O5-based nanostructures with monoclinic structure has received much attention in recent years. However, despite the great importance of this system, some of its fundamentals properties are still not fully understood. Hence, this work aims to apply the theoretical methodologies through Density Functional Theory (DFT) calculations in periodic models based on the use of different density functionals (like B1WC, B3PW, B3LYP, PBE0, PBESOL0, SOGGAXC, and WC1LYP) to investigate the physical and chemical properties of the monoclinic structure of Nb2O5. The band structures, energy bandgap, density of state, and vibrational properties, as well as order-disorder effects on the monoclinic structure of Nb2O5 are investigated in this study. Our theoretical results show a better agreement with experimental data for the B3LYP functional and hence lead to new perspectives on the deeper physicochemical understanding of the monoclinic Nb2O5. From these computational tools, it is possible to unravel the relations between structure and properties, which may contribute to the future development of new devices and applications based on these materials.

scholarly journals Characterization of gelatins from Nile tilapia skins preserved by freezing and salting

2019 ◽  
Vol 40 (6) ◽  
pp. 2581
Author(s):  
Adriana Cristina Bordignon ◽  
Maria Luiza Rodrigues de Souza ◽  
Eliane Gasparino ◽  
Edson Minoru Yajima ◽  
Jesuí Vergílio Visentainer ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Nile Tilapia ◽  
Saturated Fatty Acids ◽  
Chemical Properties ◽  
Monounsaturated Fatty Acids ◽  
Gel Strength ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

After Nile tilapia skin was preserved using the methods of freezing and dry salting, characteristics of skin gelatin were evaluated with regard to yield, rheological features and physical and chemical properties. Preservation was performed after filleting, at which time skins were either frozen (-18°C) for 7 days or salted (25°C) for 7 days. Although no differences (p > 0.05) were observed with respect to humidity, protein, lipid, ash and calcium levels, gelatin from salted skins had a higher concentration of iron relative to frozen skins. Further, twenty-three fatty acids were detected in salted skins compared with merely three found in skin derived gelatin. Of amino acids found, glycine, alanine, proline and arginine were the most abundant. Hydroxyproline abundance in salted and frozen skin gelatin were 8.76% and 8.71%, respectively. In addition, salted skin gelatins had a greater accumulation of saturated fatty acids and lower rates of monounsaturated fatty acids. Salted skin gelatin had the highest yield (18g × 100g-1), gel strength (200 g) and viscosity (19.02mPas) when compared to the yield (17g × 100g-1), gel strength (12.7g) and viscosity (9.16 mPas) of frozen skins. Results show that gelatin from dry salted skin had the best yield and also had relatively better rheological properties, more iron, and better coloration relative to gelatin obtained from frozen skins of Nile tilapia.

Physicochemical characterization of nanoparticles and their behavior in the biological environment

2014 ◽  
Vol 16 (29) ◽  
pp. 15053-15067 ◽  
Author(s):  
L. Treuel ◽  
K. A. Eslahian ◽  
D. Docter ◽  
T. Lang ◽  
R. Zellner ◽  
...  
Keyword(s):  
Physicochemical Characterization ◽  
Chemical Properties ◽  
Sufficient Accuracy ◽  
Physical And Chemical Properties ◽  
Solvent Phase ◽  
Biological Environment ◽  
Physical And Chemical ◽  
And Chemical Properties

Whilst the physical and chemical properties of nanoparticles in the gas or idealized solvent phase can nowadays be characterized with sufficient accuracy, this is no longer the case for particles in the presence of a complex biological environment.

scholarly journals OPTIMALISASI KADAR ABU DALAM PEMBUATAN MINYAK JARAK PAGAR TERVULKANISASI

2017 ◽  
Vol 2 (1) ◽  
pp. 35
Author(s):  
Santi Puspitasari ◽  
Hani Handayani ◽  
R. Siti Noviani Melinda ◽  
Yoharmus Syamsu
Keyword(s):  
Jatropha Curcas ◽  
Chemical Properties ◽  
Optimal Dose ◽  
Ash Content ◽  
Physical And Chemical Properties ◽  
Rubber Compound ◽  
Jatropha Curcas Oil ◽  
Physical And Chemical ◽  
And Chemical Properties

Optimization of Ash Content on the Synthesize of Vulcanized Jarak Pagar (Jatropha curcas) Oil         Developments in the preparation of rubber compound formulations should be followed by a rubber compounder, especially in modifying the formula. Rubber compound composed of rubber as an elastomer and its chemical. Each ingredient has a specific function and influence to the properties of rubber articles. The research studied the formulation of vulcanized oil of Jatropha curcas to obtain the best quality in terms of ash content. The experiment begins with the characterization of Jatropha curcas oil and testing of ash content of each component in the formulation of vulcanized Jatropha curcas oil. The results was used as the basis for formulation of vulcanized Jatropha curcas oil components. Vulcanized Jatropha curcas oil was synthesized at the laboratory scale (100 g oil / batch) at 140OC temperature, agitation speed of 100 rpm, and the variation of dose Na2CO3 and ZnO (0.25; 0.50, and 0.75 pho). Vulcanized Jatropha curcas oil obtained were analyzed for visualization of physical and chemical properties. The experimental results showed that the lowest of ash content of vulcanized Jatropha curcas oil was of 1.24% obtained from the reaction by the addition of 0,25 pho of Na2CO3 and 0,50 pho of ZnO. This dose was defined as the optimal dose because it gived the ash content that meets the requirements of commercial vulcanized oil (max 1.5%).Keywords: Rubber compound, elastomer, Jatropha curcas oil ABSTRAK        Perkembangan teknik formulasi dalam penyusunan kompon karet harus dapat diikuti oleh rubber compounder terutama dalam memodifikasi formula tersebut. Kompon karet tersusun atas karet sebagai elastomer dan bahan kimianya. Setiap bahan kimia karet memiliki fungsi dan pengaruh yang spesifik terhadap sifat barang jadi karet. Pada penelitian ini dipelajari formulasi bahan dalam pembuatan minyak tervulkanisasi agar diperoleh mutu terbaik ditinjau dari segi kadar abu. Percobaan diawali dengan karakterisasi minyak jarak pagar dan pengujian kadar abu setiap komponen dalam formulasi minyak jarak pagar tervulkanisasi. Hasilnya digunakan sebagai dasar penyusunan formulasi komponen minyak jarak pagar tervulkanisasi. Minyak jarak pagar tervulkanisasi dibuat pada skala laboratorium (100 g minyak/batch) pada suhu 140oC, kecepatan pengadukan 100 rpm, dan variasi dosis Na2CO3 serta ZnO (0,25; 0,50; dan 0,75 bsm). Minyak jarak pagar yang diperoleh dianalisis visualisasi fisik dan sifat kimianya. Hasil percobaan menunjukkan bahwa kadar abu minyak jarak pagar tervulaknisasi terendah sebesar 1,24% diperoleh dari reaksi dengan penambahan 0,25 bsm Na2CO3 dan 0,50 bsm ZnO. Dosis ini ditetapkan sebagai dosis optimal karena memberikan kadar abu yang memenuhi persyaratan minyak nabati tervulkanisasi komersial (maks 1,5%).Kata kunci: Kompon karet, elastomer, minyak jarak pagar

scholarly journals Industrial Gelatin from Leather Chrome Shavings Wastes

2021 ◽  
Vol 2 (10) ◽  
pp. 1035-1043
Author(s):  
Nabil H Elsayed ◽  
Ghada M. Taha ◽  
Ola A. Mohamed
Keyword(s):  
Chemical Properties ◽  
Added Value ◽  
Physical And Chemical Properties ◽  
Isolation And Characterization ◽  
Hydrolysis Products ◽  
Alkali Hydrolysis ◽  
Hydrolysis Conditions ◽  
Physical And Chemical ◽  
And Chemical Properties

A step towards minimizing the environmental pollution of leather tanning , leather chrome shavings wastes were treated with Li2CO3 to extract technical or industrial gelatin as an added value material. Isolation and characterization of gelatin obtained from chrome-tanned shavings were done. The alkali hydrolysis products obtained, showed good physical and chemical properties in terms of gel strength, swelling and thermal stability. The optimum hydrolysis conditions using Li2CO3 were found to be 5 hr. extraction at 80°C, swelling time of one day and pH 9.5. The yield was over one third of the original starting waste material.

scholarly journals A Blueprint for the Synthesis and Characterization of Thiolated Graphene

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 45
Author(s):  
Maxim K. Rabchinskii ◽  
Victor V. Sysoev ◽  
Sergei A. Ryzhkov ◽  
Ilya A. Eliseyev ◽  
Dina Yu. Stolyarova ◽  
...  
Keyword(s):  
Smart Materials ◽  
Chemical Properties ◽  
Research Community ◽  
Physical And Chemical Properties ◽  
Facile Synthesis ◽  
The Core ◽  
Physical And Chemical ◽  
Significant Attention ◽  
And Chemical Properties

Graphene derivatization to either engineer its physical and chemical properties or overcome the problem of the facile synthesis of nanographenes is a subject of significant attention in the nanomaterials research community. In this paper, we propose a facile and scalable method for the synthesis of thiolated graphene via a two-step liquid-phase treatment of graphene oxide (GO). Employing the core-level methods, the introduction of up to 5.1 at.% of thiols is indicated with the simultaneous rise of the C/O ratio to 16.8. The crumpling of the graphene layer upon thiolation without its perforation is pointed out by microscopic and Raman studies. The conductance of thiolated graphene is revealed to be driven by the Mott hopping mechanism with the sheet resistance values of 2.15 kΩ/sq and dependable on the environment. The preliminary results on the chemiresistive effect of these films upon exposure to ethanol vapors in the mix with dry and humid air are shown. Finally, the work function value and valence band structure of thiolated graphene are analyzed. Taken together, the developed method and findings of the morphology and physics of the thiolated graphene guide the further application of this derivative in energy storage, sensing devices, and smart materials.

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