scholarly journals Studies on the low molecular weight RNA associated with 28S ribosomal RNA from Crotalus durissus terrificus liver

1976 ◽  
Vol 3 (1) ◽  
pp. 165-176 ◽  
Author(s):  
J.F. Giorgini ◽  
F.L. de Lucca
Keyword(s):  
Molecular Weight ◽  
Ribosomal Rna ◽  
Low Molecular Weight ◽  
Crotalus Durissus Terrificus ◽  
Crotalus Durissus

scholarly journals Thermolability of 28S ribosomal ribonucleic acid from the liver of Crotalus durissus terrificus (Ophidia, Reptilia)

1973 ◽  
Vol 135 (1) ◽  
pp. 73-79 ◽  
Author(s):  
J. F. Giorgini ◽  
F. L. De Lucca
Keyword(s):  
Molecular Weight ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sucrose Density Gradient ◽  
Dimethyl Sulphoxide ◽  
Low Molecular Weight ◽  
28S Rrna ◽  
Sucrose Density Gradient Centrifugation ◽  
Crotalus Durissus Terrificus ◽  
Crotalus Durissus

Instability of 28S rRNA of Crotalus durissus terrificus liver was observed during hotphenol extraction: purified 28S rRNA is converted into an 18S RNA component by heat treatment. It was also found that ‘6S’ and ‘8S’ low-molecular-weight RNA species were released during the thermal conversion. This conversion and the release of the low-molecular-weight species were also induced by 8m-urea and 80% (v/v) dimethyl sulphoxide at 0°C. Evidence is presented that this phenomenon is an irreversible process and results from the rupture of hydrogen bonds. The 18S RNA product was shown to be homogeneous by polyacrylamide-gel electrophoresis and by sucrose-density-gradient centrifugation. The base composition of the 18S RNA products obtained by heat, urea or dimethyl sulphoxide treatments was similar. The C+G content of the 18S RNA product was different from that of the native 18S rRNA, but similar to that of 28S rRNA.

II. Isolierung und Charakterisierung der Chloroplasten-Ribosomen von Antirrhinum majus

1968 ◽  
Vol 23 (7) ◽  
pp. 997-1004 ◽  
Author(s):  
Hans Georg Ruppel
Keyword(s):  
Molecular Weight ◽  
Serum Albumin ◽  
High Molecular Weight ◽  
Ribosomal Rna ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Molecular Size ◽  
Antirrhinum Majus ◽  
Low Molecular Weight ◽  
Fraction I

Methods for very efficient isolation of non-degraded chloroplasts from Antirrhinum majus are described. When studied in the analytical ultracentrifuge, isolated ribosomes of such chloroplasts show a single symmetrical 68s peak. Extraction of the ribosomal RNA from chloroplasts and chromatographic separation on methylated serum albumin yields 4 main fractions: (1) low molecular weight RNA (fraction I b) with s20 = 5.5, (2) high molecular weight RNA (fraction III) with s20 = 16-17, (3) high molecular weight RNA (fraction V) with s20 = 23, and (4) a RNA fraction (fraction VI) heterogeneous in molecular size. In addition data are presented which show a higher resolution of RNA species by polyacrylamide gel electrophoresis than by chromatographic fractionation on methylated serum albumin. The high molecular weight RNA (16 -17s) of chloroplasts differs from the corresponding “light” ribosomal RNA of the cytoplasm in its electrophoretic mobility.

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

Low-molecular-weight heparin in the prevention and treatment of thromboembolic disorders

1998 ◽  
Vol 1 (5) ◽  
pp. 166-174 ◽  
Author(s):  
Evelyn R Hermes De Santis ◽  
Betsy S Laumeister ◽  
Vidhu Bansal ◽  
Vandana Kataria ◽  
Preeti Loomba ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Low Molecular Weight ◽  
Prevention And Treatment
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