scholarly journals The effect of pancreatic ribonuclease on rabbit reticulocyte ribosomes and its interpretation in terms of ribosome structure

1969 ◽  
Vol 114 (4) ◽  
pp. 753-767 ◽  
Author(s):  
R A Cox
Keyword(s):  
Optical Properties ◽  
Biological Activity ◽  
Electron Microscope ◽  
Sedimentation Coefficient ◽  
Enzymic Hydrolysis ◽  
X Ray Diffraction ◽  
Pancreatic Ribonuclease ◽  
X Ray ◽  
Low Concentrations ◽  
Melting Properties

1. Parts of the 16s and 30s RNA species of reticulocytes are readily hydrolysed by pancreatic ribonuclease. The biological activity of the ribosomes is diminished after treatment with low concentrations of the enzyme (e.g. 1ng. of ribonuclease/2·5mg. of polyribosome fraction/ml.). A high proportion of the chain scissions are ‘hidden’ owing to the secondary structure of the RNA moiety. 2. As the concentration of ribonuclease is increased RNA is lost from the ribosome. About 20–30% of the RNA may be removed from the ribosome without altering appreciably its sedimentation coefficient or its appearance in the electron microscope. 3. The amount of RNA removed from the ribosome is not increased by raising the concentration of enzyme from about 1μg. to 2·5mg. of ribonuclease/2·5mg. of polyribosome fraction/ml., or by increasing the temperature from 0° to 30°, or by first converting the RNA moiety into a single-stranded form before exposure to ribonuclease. 4. Untreated polyribosomes aggregate at about 75°, whereas ribosomes treated with ribonuclease aggregate at about 45°. The aggregates that are found on heating ribosomes after enzymic hydrolysis contain about 40–50% of the complement of RNA of intact ribosomes. 5. From the size of the fragments of RNA isolated from RNA-depleted ribosomes it is inferred that there is one site/60–100 nucleotides that is sensitive to ribonuclease. 6. The RNA moiety of RNA-depleted ribosomes has some double-helical character as shown by the optical properties and X-ray-diffraction pattern of ribonuclease-treated ribosomes and by the ‘melting’ properties of the isolated RNA. 7. Subparticles prepared by titration with an excess of EDTA are readily hydrolysed by ribonuclease to fragments of S20,w less than 4s, in contrast with the intact particle.

THE COMPOSITION, STRUCTURE, AND MECHANISM OF FORMATION OF THE LINING OF THE GIZZARD OF THE CHICKEN

1964 ◽  
Vol 42 (1) ◽  
pp. 59-70 ◽  
Author(s):  
T. E. Webb ◽  
J. Ross Colvin
Keyword(s):  
Electron Microscope ◽  
Sedimentation Coefficient ◽  
Performic Acid ◽  
X Ray Diffraction ◽  
Mechanism Of Formation ◽  
Protein Layer ◽  
Covalent Bonds ◽  
X Ray ◽  
Disulphide Bonds ◽  
Composition Structure

The extracellular protein layer which surrounds the lumen of the gizzard of the chicken has been reinvestigated to determine if it is a keratin. The lining is insoluble in keratin solvents such as urea-bisulphite or Swan's reagent as well as thioglycollate and performic acid. In addition, it contains only 1.45% sulphur so that disulphide bonds cannot play a major role in its consolidation. The lining is insoluble in acids but readily dispersed in alkali without breaking of covalent bonds. The dispersion in alkali is retarded by electrolytes. The lining is hydrolyzed by trypsin and chymotrypsin at pH 8.0 but is resistant to pepsin at pH 2.0. An alkaline dispersion of the lining is heterogeneous in the ultracentrifuge, but not grossly so, with a mean sedimentation coefficient of 5.6 svedbergs. Electron microscope studies of the lining suggest it is an amorphous, precipitated protein, which is consistent with the observation of three hazy rings in X-ray diffraction powder patterns reflecting spacings of 3.5, 4.6, and 9.4 Å. Amino acid analysis shows a ratio of more than three acidic groups to one basic, with no carbohydrate residues and little lipid in the protein layer. These observations are interpreted as indicating the precipitation of an amorphous, non-keratin, acidic, abrasion-resistant protein from the glandular mucosa by the acid in the gizzard.

scholarly journals The optical properties of C\Mg, nano-rods produced by the explosion wire technique

2021 ◽  
Vol 2114 (1) ◽  
pp. 012041
Author(s):  
Nada. K. Hussein ◽  
S.J. Kadhem
Keyword(s):  
Image Analysis ◽  
Optical Properties ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Energy Gap ◽  
Arc Discharge ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Nano Rods

Abstract The aim of this research is to study the optical properties of carbon-magnesium plasma resulting from arc discharge with explosive wire technique, where the energy gap of each of carbon and magnesium and the carbon-magnesium bond for three values of the wire exploding current (50,75,100 amperes) was studied. It was found that the energy gap for each of carbon and magnesium decreases with increasing the current, the X-ray diffraction of magnesium and the carbon-magnesium suspension was studied, and FTIR of the carbon-magnesium suspended carbon was studied for three values of the exploding current (50, 75, 100 amperes) and the type of bonds for carbon and magnesium was determined. To obtain deeper insight about the morphology and size distribution of the nano rods obtained from the explosion of a magnesium strip in a carbon suspension images obtained from transmission electron microscope (TEM) image analysis confirmed that the formed nanomaterial is rod-shaped.

scholarly journals Synthesis, photocatalytic and antidiabetic properties of ZnO/PVA nanoparticles

2021 ◽  
Author(s):  
shady M. El Dafrawy ◽  
Mahmoud Tarek ◽  
Salem Samra ◽  
Shawky M. Hassan
Keyword(s):  
Methylene Blue ◽  
Biological Activity ◽  
Electron Microscope ◽  
Methyl Orange ◽  
Sol Gel ◽  
Diabetic Rats ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Scanning Electron

Abstract We prepared a series of ZnO and ZnO/PVA catalysts by sol-gel method. The wurtzite ZnO phase was confirmed by X-ray diffraction analysis (XRD). Forming spherical shaped ZnO and ZnO/PVA nanoparticles was proved by Scanning electron microscope (SEM) images. Decomposition of Methylene Blue (MB) and methyl orange (MO) by synthesized pure ZnO and ZnO/PVA nanoparticles were studied in the UV–Vis region. ZnO/5PVA was the most active in decomposition of MB, while ZnO/7PVA was the most active in decomposition of MO. By studying biological activity of pure ZnO and ZnO/PVA in diabetic rats shows that ZnO/5PVA was the most active in lowering glucose level by different percentages.

scholarly journals Effects of Li+ Codoping on the Optical Properties of SrAl2O4 Long Afterglow Ceramic Phosphors

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Timur Sh. Atabaev ◽  
Hong Ha Thi Vu ◽  
Mac Kim ◽  
Yong Suk Yang ◽  
Hyung-Kook Kim ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Synthesis Method ◽  
Strontium Aluminate ◽  
X Ray Diffraction ◽  
High Brightness ◽  
X Ray ◽  
Long Afterglow ◽  
Scanning Electron

Rare-earths codoped long afterglow strontium aluminate phosphors with high brightness were synthesized via a facile combustion synthesis method using urea as a fuel. The resulted phosphor particles were analyzed by using X-ray diffraction and field emission scanning electron microscope, whereas their optical properties were monitored by photoluminescence spectroscopy. The prepared SrAl2O4:Eu2+, Dy3+, Li+ samples showed a broad green-yellowish emission, peaking at 512 nm when excited by 348 nm. Compared to traditional SrAl2O4:Eu2+, Dy3+ phosphor, the initial luminescence brightness of SrAl2O4:Eu2+, Dy3+, codoped with Li+ improved from 1.89 cd/m2 to 2.71 cd/m2 and the afterglow decay time was prolonged from 103 to 121 min. The possible mechanism of SrAl2O4:Eu2+, Dy3+, Li+ phosphorescence enhancement has been discussed.

Structural and optical properties of Tin Oxide and Indium doped SnO2 thin films deposited by thermal evaporation technique

2016 ◽  
Vol 12 (3) ◽  
pp. 4394-4399
Author(s):  
Sura Ali Noaman ◽  
Rashid Owaid Kadhim ◽  
Saleem Azara Hussain
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Tin Oxide ◽  
Thermal Evaporation ◽  
Pure Sno2 ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Evaporation Technique ◽  
Sno2 Thin Films

Tin Oxide and Indium doped Tin Oxide (SnO2:In) thin films were deposited on glass and Silicon  substrates  by  thermal evaporation technique.  X-ray diffraction pattern of  pure SnO2 and SnO2:In thin films annealed at 650oC and the results showed  that the structure have tetragonal phase with preferred orientation in (110) plane. AFM studies showed an inhibition of grain growth with increase in indium concentration. SEM studies of pure  SnO2 and  Indium doped tin oxide (SnO2:In) ) thin films showed that the films with regular distribution of particles and they have spherical shape.  Optical properties such as  Transmission , optical band-gap have been measured and calculated.

PENGGUNAAN TiO2 PARTIKEL NANO HASIL SINTESIS BERBASIS AIR MENGGUNAKAN METODA SOL-GEL PADA BAHAN KAPAS SEBAGAI APLIKASI UNTUK TEKSTIL ANTI UV

Arena Tekstil ◽  
2013 ◽  
Vol 28 (1) ◽  
Author(s):  
Maya Komalasari ◽  
Bambang Sunendar
Keyword(s):  
Fourier Transform ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Sol Gel ◽  
Crosslinking Agent ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
X Ray ◽  
Infra Red ◽  
Scanning Electron

Partikel nano TiO2 berbasis air dengan pH basa telah berhasil disintesis dengan menggunakan metode sol-gel dan diimobilisasi pada kain kapas dengan menggunakan kitosan sebagai zat pengikat silang. Sintesis dilakukan  dengan prekursor TiCl4 pada konsentrasi 0,3 M, 0,5 M dan 1 M, dan menggunakan templat kanji dengan proses kalsinasi pada suhu 500˚C selama 2 jam. Partikel nano TiO2 diaplikasikan ke kain kapas dengan metoda pad-dry-cure dan menggunakan kitosan sebagai crosslinking agent. Berdasarkan hasil Scanning Electron Microscope (SEM),diketahui bahwa morfologi partikel TiO2 berbentuk spherical dengan ukuran nano (kurang dari 100 nm). Karakterisasi X-Ray Diffraction (XRD) menunjukkan adanya tiga tipe struktur kristal utama, yaitu (100), (101) dan (102) dengan fasa kristal yang terbentuk adalah anatase dan rutile. Pada karakterisasi menggunakan SEM terhadap serbuk dari TiO2 yang telah diaplikasikan ke permukaan kain kapas, terlihat adanya imobilisasi partikel nano TiO2 melalui ikatan hidrogen silang dengan kitosan pada kain kapas. Hasil analisa tersebut kemudian dikonfirmasi dengan FTIR (Fourier Transform Infra Red) yang hasilnya memperlihatkan puncak serapan pada bilangan gelombang 3495 cm-1, 2546 cm-1, dan 511 cm-1,  yang masing-masing diasumsikan sebagai adanya vibrasi gugus fungsi O-H, N-H dan Ti-O-Ti. Hasil SEM menunjukkan pula bahwa kristal nano yang terbentuk diantaranya adalah fasa rutile , yang berdasarkan literatur terbukti dapatberfungsi sebagai anti UV.

scholarly journals New Haloterpenes from the Marine Red Alga Laurencia papillosa: Structure Elucidation and Biological Activity

Marine Drugs ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 35
Author(s):  
Mohamed Shaaban ◽  
Ghada S. E. Abou-El-Wafa ◽  
Christopher Golz ◽  
Hartmut Laatsch
Keyword(s):  
Biological Activity ◽  
Crude Extract ◽  
Structure Elucidation ◽  
Antimicrobial Activities ◽  
Red Alga ◽  
Spectroscopic Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Structures ◽  
Terpene Derivatives

Analysis of the air-dried marine red alga Laurencia papillosa, collected near Ras-Bakr at the Suez gulf (Red Sea) in Egypt delivered five new halogenated terpene derivatives: aplysiolic acid (1), 7-acetyl-aplysiol (2), aplysiol-7-one (3), 11,14-dihydroaplysia-5,11,14,15-tetrol (5a), and a new maneonene derivative 6, named 5-epi-maneolactone. The chemical structures of these metabolites were characterized employing spectroscopic methods, and the relative and absolute configurations were determined by comparison of experimental and ab initio-calculated NMR, NOE, ECD, and ORD data, and by X-ray diffraction of 2 and 6. The antimicrobial activities of the crude extract and compounds 1–3, 5a and 6 were studied.

Luminescent Properties of Gd2MoO6:Eu3+ Nanophosphor for WLEDs

2021 ◽  
Author(s):  
Yan Chen ◽  
Yuemei Lan ◽  
Dong Wang ◽  
Guoxing Zhang ◽  
Wenlong Peng ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Fluorescence Spectra ◽  
Solvothermal Method ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

A series of Gd2-xMoO6:xEu3+(x=0.18-0.38) nanophosphors were synthesized by the solvothermal method. The properties of this nanophosphor were characterized by x-ray diffraction (XRD), transmission electron microscope (TEM), fluorescence spectra and diffuse...

scholarly journals Study on the Electrical, Structural, Chemical and Optical Properties of PVD Ta(N) Films Deposited with Different N2 Flow Rates

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 937
Author(s):  
Yingying Hu ◽  
Md Rasadujjaman ◽  
Yanrong Wang ◽  
Jing Zhang ◽  
Jiang Yan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Photoelectron Spectroscopy ◽  
Crystal Size ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Flow Rates ◽  
X Ray ◽  
N2 Flow Rate

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.

Formation of Graphite Encapsulated Nickel Nanoparticles by Ball Milling and Annealing of Expanded Graphite with Nickel

2011 ◽  
Vol 80-81 ◽  
pp. 217-220 ◽  
Author(s):  
Xue Qing Yue ◽  
Hai Jun Fu ◽  
Da Jun Li
Keyword(s):  
Electron Microscope ◽  
Ball Milling ◽  
Transmission Electron Microscope ◽  
Nickel Nanoparticles ◽  
Size Range ◽  
Expanded Graphite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Powders ◽  
Transmission Electron

Graphite encapsulated nickel nanoparticles were prepared by ball milling andsubsequently annealing a mixture of expanded graphite with nickel powders. The products were characterized by transmission electron microscope and X-ray diffraction. The formation mechanism of the products was discussed. Results show that the products have a size range of 20-150 nm. The graphite and nickel in the products all exhibit a high crystallinity.

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