scholarly journals Prospects for technology platforms: synergistic effects

2019 ◽  
Author(s):  
Yuliya Nikitsina ◽  
Keyword(s):  
Synergistic Effects ◽  
Technology Platforms

Morphology of High-Performance Rigid-Rod Polymer Fibers and Molecular Composites

1989 ◽  
Vol 47 ◽  
pp. 338-339
Author(s):  
W.W. Adams ◽  
S. J. Krause
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Liquid Crystalline ◽  
Molecular Level ◽  
Synergistic Effects ◽  
Tensile Modulus ◽  
Commercial Development ◽  
The Matrix ◽  
Molecular Composites ◽  
Rigid Rod

Rigid-rod polymers such as PBO, poly(paraphenylene benzobisoxazole), Figure 1a, are now in commercial development for use as high-performance fibers and for reinforcement at the molecular level in molecular composites. Spinning of liquid crystalline polyphosphoric acid solutions of PBO, followed by washing, drying, and tension heat treatment produces fibers which have the following properties: density of 1.59 g/cm3; tensile strength of 820 kpsi; tensile modulus of 52 Mpsi; compressive strength of 50 kpsi; they are electrically insulating; they do not absorb moisture; and they are insensitive to radiation, including ultraviolet. Since the chain modulus of PBO is estimated to be 730 GPa, the high stiffness also affords the opportunity to reinforce a flexible coil polymer at the molecular level, in analogy to a chopped fiber reinforced composite. The objectives of the molecular composite concept are to eliminate the thermal expansion coefficient mismatch between the fiber and the matrix, as occurs in conventional composites, to eliminate the interface between the fiber and the matrix, and, hopefully, to obtain synergistic effects from the exceptional stiffness of the rigid-rod molecule. These expectations have been confirmed in the case of blending rigid-rod PBZT, poly(paraphenylene benzobisthiazole), Figure 1b, with stiff-chain ABPBI, poly 2,5(6) benzimidazole, Fig. 1c A film with 30% PBZT/70% ABPBI had tensile strength 190 kpsi and tensile modulus of 13 Mpsi when solution spun from a 3% methane sulfonic acid solution into a film. The modulus, as predicted by rule of mixtures, for a film with this composition and with planar isotropic orientation, should be 16 Mpsi. The experimental value is 80% of the theoretical value indicating that the concept of a molecular composite is valid.

A new model of synergistic effects of alcohol and high-fat diet on hepatic injury

2010 ◽  
Vol 48 (01) ◽  
Author(s):  
E Gäbele ◽  
K Dostert ◽  
C Dorn ◽  
C Hellerbrand
Keyword(s):  
High Fat Diet ◽  
Hepatic Injury ◽  
Synergistic Effects ◽  
High Fat ◽  
New Model

Landscape of Combination Therapy – Which Way Forward? Proceedings of the Satellite Symposium Held at the ESH European Meeting on Hypertension and Cardiovascular Protection, 27 April 2012, London

2012 ◽  
Vol 8 (3) ◽  
pp. 192
Author(s):  
Patricia Fonseca ◽  
Anna F Dominiczak ◽  
Stephen Harrap ◽  
◽  
◽  
...  
Keyword(s):  
Blood Pressure ◽  
High Risk ◽  
Combination Therapy ◽  
Enzyme Inhibitor ◽  
Synergistic Effects ◽  
Term Treatment ◽  
Angiotensin Ii Receptor Blocker ◽  
Angiotensin Ii Receptor ◽  
Hypertensive Patients ◽  
Long Term Treatment

Early combination therapy is more effective for hypertension control in high-risk patients than monotherapy, and current guidelines recommend the use of either an angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker (ARB) for first-line therapy in patients younger than 55 years. Recent evidence shows that ACEIs reduce mortality, whereas ARBs show no apparent benefit despite their blood pressure lowering action. However, it is important to consider which blood pressure parameters should be targeted given that different drugs have distinct effects on key parameters. Remarkably, a high percentage of hypertensive patients whose treatment has brought these parameters within target ranges still remain at high risk of cardiovascular disease due to additional risk factors. Combination therapy with synergistic effects on blood pressure and metabolic control should thus be considered for the long-term treatment of hypertensive patients with co-morbid conditions.

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