Heat treatment of high-molecular-weight cellulose acetate fibres

1993 ◽  
Vol 24 (6) ◽  
pp. 467-469 ◽  
Author(s):  
E. A. Nekhaenko ◽  
L. S. Gembitskii ◽  
N. V. Protsenko ◽  
I. V. Stepanova ◽  
N. L. Kuz'mina ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Molecular Weight ◽  
Cellulose Acetate ◽  
High Molecular Weight

Stabilization of the properties of high-molecular-weight cellulose acetate

1994 ◽  
Vol 26 (1) ◽  
pp. 36-38
Author(s):  
E. A. Nekhaenko ◽  
L. S. Gembitskii ◽  
N. V. Protsenko ◽  
R. P. Papikyan ◽  
N. L. Kuz'mina ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Cellulose Acetate ◽  
High Molecular Weight

Heat-induced changes in sulphydryl and disulphide levels of β-lactoglobulin A and the formation of polymers

1976 ◽  
Vol 43 (3) ◽  
pp. 411-418 ◽  
Author(s):  
K. Watanabe ◽  
H. Klostermeyer
Keyword(s):  
Heat Treatment ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Exchange Reactions ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Ph Values ◽  
Different Temperatures ◽  
Induced Changes ◽  
Β Lactoglobulin

SummaryThe effects of heat and pH on sulphydryl (–SH) and disulphide (–SS–) groups of β-lactoglobulin (β-lg) A have been studied by heating at different temperatures and pH values in air and at pH 6·9 in the absence of air. At pH 6·9 under aerobic conditions a decrease of –SH groups and an increase of –SS– groups was observed with increasing time and temperature. Only small changes were found under anaerobic conditions. At pH from 3·0 to 9·8 the –SH level decreased while the –SS– level increased up to pH 6·9 and then dropped rapidly. In addition to –SH/–SS– interchange there were reactions to other sulphur-containing compounds as seen from the losses in the total amount of –SH plus –SS– sulphur. The results of gelchromatographic investigations suggest that –SH-initiated –SS– exchange-reactions play an important role in the formation of high molecular weight polymers of β-lg A during heat treatment, and that the formation of intermediates depends on the presence of air.

Modification of Microscopic Zirconia Surface Structure for Improvement in Tribological Characteristics of UHMWPE-on-Zirconia Sliding Pair for Joint Prostheses

2005 ◽  
Author(s):  
Y. Sawae ◽  
T. Murakami ◽  
H. Qiwei ◽  
T. Sawano
Keyword(s):  
Heat Treatment ◽  
Molecular Weight ◽  
Friction Coefficient ◽  
High Molecular Weight ◽  
Grain Structure ◽  
Tribological Characteristics ◽  
Microscopic Structure ◽  
Joint Prostheses ◽  
Articulating Surface ◽  
Ultra High Molecular Weight

In this study, authors attempted to improve tribological characteristics of ultra-high molecular weight polyethylene (UHMWPE)-on-zirconia sliding pair for joint prostheses by modifying a microscopic structure of ceramics articulating surface. Experimental results indicated that the friction coefficient of UHMWPE-on-zirconia sliding pair could be lowered by inhibiting a formation of crystal grain structure on an articulating surface during a heat treatment.

Microtubule motors and other maps

1990 ◽  
Vol 48 (3) ◽  
pp. 1-1
Author(s):  
Richard B. Vallee
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Cytoplasmic Dynein ◽  
Organelle Transport ◽  
Structural Components ◽  
Microtubule Associated Proteins ◽  
Microtubule Motors ◽  
Associated Proteins ◽  
The Subject ◽  
Intracellular Motility

Microtubules are involved in a number of forms of intracellular motility, including mitosis and bidirectional organelle transport. Purified microtubules from brain and other sources contain tubulin and a diversity of microtubule associated proteins (MAPs). Some of the high molecular weight MAPs - MAP 1A, 1B, 2A, and 2B - are long, fibrous molecules that serve as structural components of the cytamatrix. Three MAPs have recently been identified that show microtubule activated ATPase activity and produce force in association with microtubules. These proteins - kinesin, cytoplasmic dynein, and dynamin - are referred to as cytoplasmic motors. The latter two will be the subject of this talk.Cytoplasmic dynein was first identified as one of the high molecular weight brain MAPs, MAP 1C. It was determined to be structurally equivalent to ciliary and flagellar dynein, and to produce force toward the minus ends of microtubules, opposite to kinesin.

Studies on the Functionality of Newly Synthesized Fibrinogen after Treatment of Acute Myocardial Infarction with Streptokinase, Increase in the Rate of Fibrinopeptide Release

1993 ◽  
Vol 70 (06) ◽  
pp. 0978-0983 ◽  
Author(s):  
Edelmiro Regano ◽  
Virtudes Vila ◽  
Justo Aznar ◽  
Victoria Lacueva ◽  
Vicenta Martinez ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Molecular Weight ◽  
Steady State ◽  
High Molecular Weight ◽  
Coronary Arteries ◽  
Risk Index ◽  
Weight Fraction ◽  
High Molecular Weight Fraction ◽  
Fibrinopeptide A

SummaryIn 15 patients with acute myocardial infarction who received 1,500,000 U of streptokinase, the gradual appearance of newly synthesized fibrinogen and the fibrinopeptide release during the first 35 h after SK treatment were evaluated. At 5 h the fibrinogen circulating in plasma was observed as the high molecular weight fraction (HMW-Fg). The concentration of HMW-Fg increased continuously, and at 20 h reached values higher than those obtained from normal plasma. HMW-Fg represented about 95% of the total fibrinogen during the first 35 h. The degree of phosphorylation of patient fibrinogen increased from 30% before treatment to 65% during the first 5 h, and then slowly declined to 50% at 35 h.The early rates of fibrinopeptide A (FPA) and phosphorylated fibrinopeptide A (FPAp) release are higher in patient fibrinogen than in isolated normal HMW-Fg and normal fibrinogen after thrombin addition. The early rate of fibrinopeptide B (FPB) release is the same for the three fibrinogen groups. However, the late rate of FPB release is higher in patient fibrinogen than in normal HMW-Fg and normal fibrinogen. Therefore, the newly synthesized fibrinogen clots faster than fibrinogen in the normal steady state.In two of the 15 patients who had occluded coronary arteries after SK treatment the HMW-Fg and FPAp levels increased as compared with the 13 patients who had patent coronary arteries.These results provide some support for the idea that an increased synthesis of fibrinogen in circulation may result in a procoagulant tendency. If this is so, the HMW-Fg and FPAp content may serve as a risk index for thrombosis.

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