Thermodynamic Stabilization of Powder-Route Nanocrystalline Tungsten Alloys

2013 ◽  
Author(s):  
Christopher A. Schuh
Keyword(s):  
Tungsten Alloys ◽  
Thermodynamic Stabilization

scholarly journals Near quantitative synthesis of urea macrocycles enabled by bulky N-substituent

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yingfeng Yang ◽  
Hanze Ying ◽  
Zhixia Li ◽  
Jiang Wang ◽  
Yingying Chen ◽  
...  
Keyword(s):  
High Efficiency ◽  
Molecular Structures ◽  
High Yield ◽  
Kinetic Control ◽  
High Concentration ◽  
Weak Association ◽  
Quantitative Synthesis ◽  
Thermodynamic Stabilization ◽  
Discrete Structures ◽  
Very High

AbstractMacrocycles are unique molecular structures extensively used in the design of catalysts, therapeutics and supramolecular assemblies. Among all reactions reported to date, systems that can produce macrocycles in high yield under high reaction concentrations are rare. Here we report the use of dynamic hindered urea bond (HUB) for the construction of urea macrocycles with very high efficiency. Mixing of equal molar diisocyanate and hindered diamine leads to formation of macrocycles with discrete structures in nearly quantitative yields under high concentration of reactants. The bulky N-tert-butyl plays key roles to facilitate the formation of macrocycles, providing not only the kinetic control due to the formation of the cyclization-promoting cis C = O/tert-butyl conformation, but also possibly the thermodynamic stabilization of macrocycles with weak association interactions. The bulky N-tert-butyl can be readily removed by acid to eliminate the dynamicity of HUB and stabilize the macrocycle structures.

Stabilization of telomeric G-quadruplex by ligand binding increases susceptibility to S1 nuclease

2021 ◽  
Author(s):  
Ryo Ishikawa ◽  
Mizuho Yasuda ◽  
Shogo Sasaki ◽  
Yue Ma ◽  
Kazuo Nagasawa ◽  
...  
Keyword(s):  
Ligand Binding ◽  
S1 Nuclease ◽  
G Quadruplex ◽  
Thermodynamic Stabilization

The extent of thermodynamic stabilization of telomeric G-quadruplex (G4) by isomers of G4 ligand L2H2-6OTD, a telomestatin analog, is inversely correlated with susceptibility to S1 nuclease. L2H2-6OTD facilitated the S1...

Fracture toughness investigations of tungsten alloys and SPD tungsten alloys

2007 ◽  
Vol 367-370 ◽  
pp. 800-805 ◽  
Author(s):  
M. Faleschini ◽  
H. Kreuzer ◽  
D. Kiener ◽  
R. Pippan
Keyword(s):  
Fracture Toughness ◽  
Tungsten Alloys

The Magnetism of Nickel and Tungsten Alloys

1888 ◽  
Vol 24 ◽  
pp. 181 ◽  
Author(s):  
John Trowbridge ◽  
Samuel Sheldon
Keyword(s):  
Tungsten Alloys ◽  
And Tungsten

scholarly journals Comparative Assessment of Tungsten Toxicity in the Absence or Presence of Other Metals

Toxics ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 66 ◽  
Author(s):  
Ola Wasel ◽  
Jennifer Freeman
Keyword(s):  
Human Exposure ◽  
Potable Water ◽  
Comparative Assessment ◽  
Tungsten Alloy ◽  
Tungsten Alloys ◽  
Mechanisms Of Toxicity ◽  
Adverse Health Effects ◽  
Current State ◽  
Wide Range ◽  
Military Applications

Tungsten is a refractory metal that is used in a wide range of applications. It was initially perceived that tungsten was immobile in the environment, supporting tungsten as an alternative for lead and uranium in munition and military applications. Recent studies report movement and detection of tungsten in soil and potable water sources, increasing the risk of human exposure. In addition, experimental research studies observed adverse health effects associated with exposure to tungsten alloys, raising concerns on tungsten toxicity with questions surrounding the safety of exposure to tungsten alone or in mixtures with other metals. Tungsten is commonly used as an alloy with nickel and cobalt in many applications to adjust hardness and thermal and electrical conductivity. This review addresses the current state of knowledge in regard to the mechanisms of toxicity of tungsten in the absence or presence of other metals with a specific focus on mixtures containing nickel and cobalt, the most common components of tungsten alloy.

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