The synthesis of model block copolymers of Poly(cis-1,4-isoprene : styrene)

1968 ◽  
Vol 21 (7) ◽  
pp. 1835 ◽  
Author(s):  
DN Cramond ◽  
JR Urwin
Keyword(s):  
Block Copolymers ◽  
Molecular Size ◽  
Model Block

The synthesis of model block copolymers of poly(cis-1,4-isoprene : styrene)initiated by butyllithium in the solvent benzene is described in detail, and the analysis of the microstructure of the polyisoprene sequence discussed. The copolymers were found to be of narrow distribution in molecular size and composition and the microstructure was close to that expected from previously published results on the synthesis of polyisoprenes.

Predicting the Effects of Composition, Molecular Size and Shape, Plasticization, and Swelling on the Diffusion of Aromatic Additives in Block Copolymers

2017 ◽  
Vol 50 (16) ◽  
pp. 6137-6148 ◽  
Author(s):  
Dustin W. Janes ◽  
Vaishnavi Chandrasekar ◽  
Steven E. Woolford ◽  
Kyle B. Ludwig
Keyword(s):  
Block Copolymers ◽  
Molecular Size ◽  
Size And Shape

Model block copolymers with complex architecture

1998 ◽  
Vol 132 (1) ◽  
pp. 207-220 ◽  
Author(s):  
Nikos Hadjichristidis ◽  
Yiannis Poulos ◽  
Apostolus Avgeropoulos
Keyword(s):  
Block Copolymers ◽  
Model Block ◽  
Complex Architecture

scholarly journals The Mechanism of the Helix-Sense Inversion of Polyaspartates as Revealed by the Study of Model Block Copolymers

2002 ◽  
Vol 34 (6) ◽  
pp. 450-454 ◽  
Author(s):  
Akinobu Ushiyama ◽  
Hidemine Furuya ◽  
Akihiro Abe ◽  
Toshimasa Yamazaki
Keyword(s):  
Block Copolymers ◽  
Model Block

Characterization of Recombinant Human Coagulation Factor XFriuli

1996 ◽  
Vol 75 (02) ◽  
pp. 313-317 ◽  
Author(s):  
D J Kim ◽  
A Girolami ◽  
H L James
Keyword(s):  
Catalytic Domain ◽  
Coagulation Factor ◽  
Molecular Size ◽  
Binding Pocket ◽  
Site Directed Mutagenesis ◽  
Bleeding Tendency ◽  
Factor X ◽  
Amino Terminal ◽  
Normal Plasma ◽  
Plasma Factor

SummaryNaturally occurring plasma factor XFriuli (pFXFr) is marginally activated by both the extrinsic and intrinsic coagulation pathways and has impaired catalytic potential. These studies were initiated to obtain confirmation that this molecule is multi-functionally defective due to the substitution of Ser for Pro at position 343 in the catalytic domain. By the Nelson-Long site-directed mutagenesis procedure a construct of cDNA in pRc/CMV was derived for recombinant factor XFriuli (rFXFr) produced in human embryonic (293) kidney cells. The rFXFr was purified and shown to have a molecular size identical to that of normal plasma factor X (pFX) by gel electrophoretic, and amino-terminal sequencing revealed normal processing cleavages. Using recombinant normal plasma factor X (rFXN) as a reference, the post-translational y-carboxy-glutamic acid (Gla) and (β-hydroxy aspartic acid (β-OH-Asp) content of rFXFr was over 85% and close to 100%, respectively, of expected levels. The specific activities of rFXFr in activation and catalytic assays were the same as those of pFXFr. Molecular modeling suggested the involvement of a new H-bond between the side-chains of Ser-343 and Thr-318 as they occur in anti-parallel (3-pleated sheets near the substrate-binding pocket of pFXFr. These results support the conclusion that the observed mutation in pFXFr is responsible for its dysfunctional activation and catalytic potentials, and that it accounts for the moderate bleeding tendency in the homozygous individuals who possess this variant procoagulant.

Suppressive Effect of Dextran on Platelet Adhesiveness

1966 ◽  
Vol 16 (03/04) ◽  
pp. 384-394 ◽  
Author(s):  
S Cronberg ◽  
B Robertson ◽  
Inga Marie Nilsson ◽  
J.-E Niléhn
Keyword(s):  
Molecular Weight ◽  
Bleeding Time ◽  
Slight Modification ◽  
Molecular Size ◽  
Suppressive Effect ◽  
Factor Ix ◽  
Factor V ◽  
Platelet Adhesiveness ◽  
History Of ◽  
Mean Molecular Weight

Summary43 normal volunteers, 3 patients with thrombophlebitis, and 1 patient with a high platelet adhesiveness and a history of thrombophlebitis have received dextran and its action on the mechanism of haemostasis has been studied. Platelet adhesiveness has been investigated by a slight modification of Hellem’s methods for whole blood and plasma. Dextran with a mean molecular weight of 70,000 produced a markedly lowered platelet adhesiveness together with a moderate prolongation of the Ivy bleeding time. Factor VIII was decreased by about 50% and factor V, factor IX and fibrinogen were decreased slightly more than could be expected from haemodilution alone. No fibrinolysis occurred. Dextran of lower molecular size was less potent. The possible use of dextrans as a thrombosis prophylactic agent is discussed.

Self-Assembly of Hydrogels From Elastin-Mimetic Block Copolymers

2002 ◽  
Vol 724 ◽  
Author(s):  
Elizabeth R. Wright ◽  
R. Andrew McMillan ◽  
Alan Cooper ◽  
Robert P. Apkarian ◽  
Vincent P. Conticello
Keyword(s):  
Block Copolymers ◽  
Self Assembly ◽  
Triblock Copolymers ◽  
Variable Temperature ◽  
Inverse Temperature ◽  
Temperature Transition ◽  
Scanning Calorimetry ◽  
Design Synthesis ◽  
Inverse Temperature Transition ◽  
Functional Biomaterials

AbstractTriblock copolymers have traditionally been synthesized with conventional organic components. However, triblock copolymers could be synthesized by the incorporation of two incompatible protein-based polymers. The polypeptides would differ in their hydrophobicity and confer unique physiochemical properties to the resultant materials. One protein-based polymer, based on a sequence of native elastin, that has been utilized in the synthesis of biomaterials is poly (Valine-Proline-Glycine-ValineGlycine) or poly(VPGVG) [1]. This polypeptide has been shown to have an inverse temperature transition that can be adjusted by non-conservative amino acid substitutions in the fourth position [2]. By combining polypeptide blocks with different inverse temperature transition values due to hydrophobicity differences, we expect to produce amphiphilic polypeptides capable of self-assembly into hydrogels. Our research examines the design, synthesis and characterization of elastin-mimetic block copolymers as functional biomaterials. The methods that are used for the characterization include variable temperature 1D and 2D High-Resolution-NMR, cryo-High Resolutions Scanning Electron Microscopy and Differential Scanning Calorimetry.

Use of Nonionic Block Copolymers in Vaccines and Therapeutics

1998 ◽  
Vol 15 (2) ◽  
pp. 89-142 ◽  
Author(s):  
Mark J. Newman ◽  
Jeffrey K. Actor ◽  
Mannersamy Balusubramanian ◽  
Chinnaswamy Jagannath
Keyword(s):  
Block Copolymers

Mechanical and Structural Consequences of Associative Dynamic Cross-Linking in Acrylic Diblock Copolymers

2019 ◽  
Author(s):  
Jacob Ishibashi ◽  
Yan Fang ◽  
Julia Kalow
Keyword(s):  
Block Copolymers ◽  
Rheological Properties ◽  
Diblock Copolymers ◽  
Cross Linking ◽  
Statistical Copolymer

<p>Block copolymers are used to construct covalent adaptable networks that employ associative exchange chemistry (vitrimers). The resulting vitrimers display markedly different nanostructural, thermal and rheological properties relative to those of their statistical copolymer-derived counterparts. This study demonstrates that prepolymer sequence is a versatile strategy to modify the properties of vitrimers.</p>

Medicinal Chemistry Database GDBMedChem

2019 ◽  
Author(s):  
Mahendra Awale ◽  
Finton Sirockin ◽  
Nikolaus Stiefl ◽  
Jean-Louis Reymond
Keyword(s):  
Small Molecules ◽  
Natural Product ◽  
Medicinal Chemistry ◽  
3D Visualization ◽  
Molecular Size ◽  
Similarity Searching ◽  
Complex Molecules ◽  
Synthetic Accessibility ◽  
Simple Chemical ◽  
Reduced Complexity

<div>The generated database GDB17 enumerates 166.4 billion possible molecules up to 17 atoms of C, N, O, S and halogens following simple chemical stability and synthetic feasibility rules, however medicinal chemistry criteria are not taken into account. Here we applied rules inspired by medicinal chemistry to exclude problematic functional groups and complex molecules from GDB17, and sampled the resulting subset evenly across molecular size, stereochemistry and polarity to form GDBMedChem as a compact collection of 10 million small molecules.</div><div><br></div><div>This collection has reduced complexity and better synthetic accessibility than the entire GDB17 but retains higher sp 3 - carbon fraction and natural product likeness scores compared to known drugs. GDBMedChem molecules are more diverse and very different from known molecules in terms of substructures and represent an unprecedented source of diversity for drug design. GDBMedChem is available for 3D-visualization, similarity searching and for download at http://gdb.unibe.ch.</div>

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