The Crucial Role of Water in the Stability and Electrocatalytic Activity of Pt Electrodes

Author(s):  
Johanna Ranninger ◽  
Karl J. J. Mayrhofer ◽  
Balázs B. Berkes
2015 ◽  
Vol 128 (17) ◽  
pp. 3317-3329 ◽  
Author(s):  
S. Li ◽  
J. Wang ◽  
Y. Wei ◽  
Y. Liu ◽  
X. Ding ◽  
...  

2018 ◽  
Vol 6 (26) ◽  
pp. 12565-12573 ◽  
Author(s):  
Jang Mee Lee ◽  
Sharad B. Patil ◽  
Bohyun Kang ◽  
Seul Lee ◽  
Min Gyu Kim ◽  
...  

In situ spectroscopic investigation elucidates the crucial role of local structural order in the excellent electrocatalytic activity of crystalline MnO2.


2020 ◽  
Author(s):  
Wenjun Yang ◽  
Ivan Yu. Chernyshov ◽  
Robin K. A. van Schendel ◽  
Manuela Weber ◽  
Christian Müller ◽  
...  

<div>The foremost requirement for any catalyst to be</div><div>implemented in practice is its efficiency and stability. This</div><div>requirement is particularly valid for manganese hydrogenation catalysts representing more sustainable alternatives to conventional noble metal-based systems. Herein, we report a highly efficient Mn(I)-CNP pre-catalyst featuring phosphine arm hemilability, which gives rise to the excellent productivity (TOF° up to 41 000 h-1) and outstanding stability (TON up to 200 000) in hydrogenation catalysis. This system enables near-quantitative hydrogenation of ketones, imines, aldehydes, and esters at the catalyst loadings as low as 5-200 ppm. Our analysis points to the crucial role of the phosphine hemilability for the catalyst activation step and the stability of the reactive species under the catalytic conditions. Unprecedented in</div><div>manganese hydrogenation catalysis, this unusual coordination behavior might have general utility for improving catalysis by Mn complexes and bringing them yet another competitive advantage.</div>


2021 ◽  
Vol 118 (3) ◽  
pp. e2015416118
Author(s):  
Panpan Hou ◽  
Penghui Jia ◽  
Kongxiang Yang ◽  
Zibo Li ◽  
Tian Tian ◽  
...  

Nuclear factor κB (NF-κB)–mediated signaling pathway plays a crucial role in the regulation of inflammatory process, innate and adaptive immune responses. The hyperactivation of inflammatory response causes host cell death, tissue damage, and autoinflammatory disorders, such as sepsis and inflammatory bowel disease. However, how these processes are precisely controlled is still poorly understood. In this study, we demonstrated that ankyrin repeat and suppressor of cytokine signaling box containing 1 (ASB1) is involved in the positive regulation of inflammatory responses by enhancing the stability of TAB2 and its downstream signaling pathways, including NF-κB and mitogen-activated protein kinase pathways. Mechanistically, unlike other members of the ASB family that induce ubiquitination-mediated degradation of their target proteins, ASB1 associates with TAB2 to inhibit K48-linked polyubiquitination and thereby promote the stability of TAB2 upon stimulation of cytokines and lipopolysaccharide (LPS), which indicates that ASB1 plays a noncanonical role to further stabilize the target protein rather than induce its degradation. The deficiency of Asb1 protects mice from Salmonella typhimurium– or LPS-induced septic shock and increases the survival of mice. Moreover, Asb1-deficient mice exhibited less severe colitis and intestinal inflammation induced by dextran sodium sulfate. Given the crucial role of ASB proteins in inflammatory signaling pathways, our study offers insights into the immune regulation in pathogen infection and inflammatory disorders with therapeutic implications.


2015 ◽  
Vol 30 (27) ◽  
pp. 1550165
Author(s):  
S. Kalyana Rama

Unitarity of evolution in gravitational collapses implies existence of macroscopic stable horizonless objects. With such objects in mind, we study the effects of anisotropy of pressures on the stability of stars. We consider stars in four or higher dimensions and also stars in M theory made up of (intersecting) branes. Taking the stars to be static, spherically symmetric and the equations of state to be linear, we study “singular solutions” and the asymptotic perturbations around them. Oscillatory perturbations are likely to imply instability. We find that nonoscillatory perturbations, which may imply stability, are possible if an appropriate amount of anisotropy is present. This result suggests that it may be possible to have stable horizonless objects in four or any higher dimensions, and that anisotropic pressures may play a crucial role in ensuring their stability.


2020 ◽  
Author(s):  
Wenjun Yang ◽  
Ivan Yu. Chernyshov ◽  
Robin K. A. van Schendel ◽  
Manuela Weber ◽  
Christian Müller ◽  
...  

<div>The foremost requirement for any catalyst to be</div><div>implemented in practice is its efficiency and stability. This</div><div>requirement is particularly valid for manganese hydrogenation catalysts representing more sustainable alternatives to conventional noble metal-based systems. Herein, we report a highly efficient Mn(I)-CNP pre-catalyst featuring phosphine arm hemilability, which gives rise to the excellent productivity (TOF° up to 41 000 h-1) and outstanding stability (TON up to 200 000) in hydrogenation catalysis. This system enables near-quantitative hydrogenation of ketones, imines, aldehydes, and esters at the catalyst loadings as low as 5-200 ppm. Our analysis points to the crucial role of the phosphine hemilability for the catalyst activation step and the stability of the reactive species under the catalytic conditions. Unprecedented in</div><div>manganese hydrogenation catalysis, this unusual coordination behavior might have general utility for improving catalysis by Mn complexes and bringing them yet another competitive advantage.</div>


2019 ◽  
Vol 49 (4) ◽  
pp. 617-641
Author(s):  
Eyene Okpanachi

Abstract Since Nigeria’s return to electoral rule in 1999, the People’s Democratic Party (PDP) ruled the country as the majority party at both levels of its federal system until 2015. However, despite this dominance, the relationship between presidents and governors was often so divisive that the instability within the party threatened the stability of not only the ruling governments, but also the federation as a whole and undermined its productivity. This article examines this anomaly against the background of scholarship emphasizing the crucial role of federation-wide parties in fostering smooth intergovernmental bargains and in facilitating federal stability. It argues that Nigeria’s recent experience provides counterevidence of this theory and discusses the mutually reinforcing contextual factors that might have influenced this development, focusing on the PDP’s norms and the country’s intergovernmental fiscal structure.


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