scholarly journals THE NON-VIRUS PROTEINS ASSOCIATED WITH TOBACCO MOSAIC VIRUS

1955 ◽  
Vol 38 (4) ◽  
pp. 459-473 ◽  
Author(s):  
Barry Commoner ◽  
Mas Yamada
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Infected Plant ◽  
Infected Leaf ◽  
Low Molecular Weight ◽  
Tobacco Plants ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Derivatives Of ◽  
Virus Proteins

1. Exhaustive fractionation of leaves from tobacco plants systemically infected with TMV has led to the isolation of two non-virus proteins, B3 and B6, and the detection of a third, A4, which do not occur in comparable uninfected plants. 2. Components B3 and B6 have been found consistently in a series of ten extracts from plants grown over an 18 month period in all seasons of the year. It is concluded that these components are as characteristic of the infected plant as TMV itself. 3. As they occur in the initial extracts, the non-virus proteins are of low molecular weight (S20 ca. 3). On treatment, each component tends to form a high molecular weight polymer with an electrophoretic mobility considerably greater than that of the starting material. The high molecular weight derivatives of A4, B3, and B6 have been designated A8, B8, and B7 respectively. There is no evidence that these high molecular weight components occur as such in the infected leaf. 4. The non-virus proteins are free of nucleic acid and are not infectious. They cross-react immunochemically with TMV. 5. Compared with TMV content, the amounts of the non-virus proteins found in infected leaf are relatively small, falling in the range of 10 to 150 micrograms per gm. of tissue.

Experimental Study on Flow-Front Fingering Instabilities in Injection Molding of Polymer Solutions and Melts

2004 ◽  
Author(s):  
Kalonji K. Kabanemi ◽  
Jean-Franc¸ois He´tu ◽  
Samira H. Sammoun
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polymer Solutions ◽  
Low Molecular Weight ◽  
Flow Front ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Polymer Molecules ◽  
Molecular Weights ◽  
Solvent Molecules

An experimental investigation of the flow behavior of dilute, semi-dilute and concentrated polymer solutions has been carried out to gain a better understanding of the underlying mechanisms leading to the occurrence of instabilities at the advancing flow front during the filling of a mold cavity. Experiments were performed using various mass concentrations of low and high molecular weight polyacrylamide polymers in corn syrup and water. This paper reports a new type of elastic fingering instabilities at the advancing flow front that has been observed only in semi-dilute polymer solutions of high molecular weight polymers. These flow front elastic instabilities seem to arise as a result of a mixture of widely separated high molecular weight polymer molecules and low molecular weight solvent molecules, which gives rise to a largely non-uniform polydisperse solution, with respect to all the kinds of molecules in the resulting mixture (solvent molecules and polymer molecules). The occurrence of these instabilities appears to be independent of the injection flow rate and the cavity thickness. Moreover, these instabilities do not manifest themselves in dilute or concentrated regimes, where respectively, polymer molecules and solvent molecules are minor perturbation of the resulting solution. In those regimes, smooth flow fronts are confirmed from our experiments. Based on these findings, the experimental investigations have been extended to polymer melts. Different mixtures of polycarbonate melts of widely separated molecular weights (low and high molecular weights) were first prepared. The effect of the large polydispersity of the resulting mixtures on the flow front behavior was subsequently studied. The same instabilities at the flow front were observed only in the experiments where a very small amount of high molecular weight polycarbonate polymer has been mixed to a low molecular weight polycarbonate melt (oligomers).

Intrinsic viscoelasticity in thin high-molecular-weight polymer films

2014 ◽  
Vol 89 (6) ◽  
Author(s):  
Xiaoyuan Sheng ◽  
Frédéric Wintzenrieth ◽  
Katherine R. Thomas ◽  
Ullrich Steiner
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polymer Films ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer

8 Final Report on the Safety Assessment of Polyquaternium-11

1983 ◽  
Vol 2 (5) ◽  
pp. 161-178 ◽  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Skin Irritation ◽  
Low Molecular Weight ◽  
Final Report ◽  
Dermal Toxicity ◽  
Molecular Weight Polymer ◽  
Patch Tests ◽  
Skin Patch ◽  
Available Information

Polyquaternium-11 is a quaternized copolymer of vinylpyrrolidone and di-methylamine ethylmethacrylate, and is used at concentrations up to 50% in a variety of hair care preparations. The acute oral LD50 in test animals of high molecular weight Polyqua-ternium-11 is estimated to be greater than 12.8 g/kg; the LD50 for the low molecular weight polymer is calculated to be 6.2 g/kg. At concentrations of up to 50% in water, the raw ingredient produced no signs of skin or eye irritation. There was no evidence of dermal toxicity in subchronic tests nor in a maximization test for sensitization. In clinical studies, 1 of 19 subjects showed slight skin irritation after a 24-hour single insult skin patch with 9.5% Polyquaternium-11 in water. Repeated insult patch tests at concentrations up to 50% produced no instances of skin sensitization and only isolated instances of transient skin irritation. Clinical photoreactivity studies on both low and high molecular weight polymers showed no evidence of phototoxicity or photoallergenicity. From the available information, it is concluded that Polyquaternium-11 is safe as a cosmetic ingredient in the present practices of use.

Structural studies of the capsular polysaccharide from Haemophilus pleuropneumoniae serotype 2

1987 ◽  
Vol 65 (5) ◽  
pp. 414-422 ◽  
Author(s):  
Eleonora Altman ◽  
Jean-Robert Brisson ◽  
Malcolm B. Perry
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Molecular Weight ◽  
Capsular Polysaccharide ◽  
Structural Studies ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Structure Formula ◽  
Nuclear Magnetic

The capsular polysaccharide of Haemophilus pleuropneumoniae serotype 2 (ATCC 27089) is composed of D-glucose (two parts), D-galactose (one part), glycerol (one part), and phosphate (one part). Hydrolysis, dephosphorylation, methylation, enzymic studies, and 1H and 13C nuclear magnetic resonance experiments showed that the polysaccharide is a high molecular weight polymer of a tetrasaccharide repeating units, linked by monophosphate diester and having the following structure:[Formula: see text]

scholarly journals Antigen valence determines the binding of nominal antigen to cytolytic T cell clones.

1985 ◽  
Vol 162 (2) ◽  
pp. 768-773 ◽  
Author(s):  
R F Siliciano ◽  
R M Colello ◽  
A D Keegan ◽  
R Z Dintzis ◽  
H M Dintzis ◽  
...  
Keyword(s):  
Molecular Weight ◽  
T Cell ◽  
High Molecular Weight ◽  
Cytotoxic T Cell ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
T Cell Clones ◽  
Cell Clones ◽  
Nominal Antigen ◽  
Epitope Density

We have shown that cytotoxic T cell clones specific for the nominal antigen FL will bind high molecular weight (600,000 to 2,000,000) polyacrylamide and Ficoll polymers conjugated with 200-600 FL groups per molecule. Low molecular weight polymers (40,000) with the same epitope density did not give stable binding. A high molecular weight polymer with a lower epitope density also failed to bind. Taken together, these results suggest that a substantial degree of multivalence is a necessary factor in the stable binding of nominal antigen to T cell clones.

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