Single molybdenum atom anchored on 2D Ti2NO2 MXene as a promising electrocatalyst for N2 fixation

Nanoscale ◽  
2019 ◽  
Vol 11 (39) ◽  
pp. 18132-18141 ◽  
Author(s):  
Yuwen Cheng ◽  
Jianhong Dai ◽  
Yan Song ◽  
Yumin Zhang
Keyword(s):  
N2 Fixation ◽  
Molybdenum Atom ◽  
Enzymatic Mechanism

Mo anchored on Ti2NO2 (Mo/Ti2NO2) surface possesses superior NRR performance, with an overpotential ηNRR of 0.16 V via enzymatic mechanism.

Selection of soybean (Glycine max) lines for increased tolerance of N2 fixation to drying soil

Agronomie ◽  
2001 ◽  
Vol 21 (6-7) ◽  
pp. 653-657 ◽  
Author(s):  
Thomas R. Sinclair ◽  
Larry C. Purcell ◽  
Vincent Vadez ◽  
Rachid Serraj
Keyword(s):  
Glycine Max ◽  
N2 Fixation ◽  
Selection Of

Platelet-Bound Prekallikrein Promotes Pro-Urokinase-Induced Clot Lysis: A Mechanism for Targeting the Factor XII Dependent Intrinsic Pathway of Fibrinolysis

1994 ◽  
Vol 71 (03) ◽  
pp. 347-352 ◽  
Author(s):  
Jean-Pierre Loza ◽  
Victor Gurewich ◽  
Michael Johnstone ◽  
Ralph Pannell
Keyword(s):  
Platelet Rich Plasma ◽  
Specific Inhibitor ◽  
Specific Effect ◽  
Clot Lysis ◽  
Factor Xii ◽  
Intrinsic Pathway ◽  
Clot Retraction ◽  
Enzymatic Mechanism ◽  
Low Concentrations ◽  
Factor Xiia

SummaryClots formed from platelet rich plasma were found to be lysed more readily by low concentrations of pro-urokinase (pro-UK) than clots formed from platelet poor plasma. This was not a non-specific effect since the reverse occurred with tissue plasminogen activator. A mechanical explanation due to platelet-mediated clot retraction was excluded by experiments in which retraction was inhibited with cyto-chalasin B. Therefore, a platelet-mediated enzymatic mechanism was postulated to explain the promotion of fibrinolysis. Casein autography of isolated platelets revealed a ≈ 90 kDa band of activity which comigrated with plasma prekallikrein (PK)/kallikrein, a known activator of pro-UK. Furthermore, treatment of platelets with plasma PK activator (PPA), consisting essentially of factor XIIa, induced activation of pro-UK and of chromomgenic substrate for kallikrein (S-2302). This activity corresponded to approximately 40-200 pM kallikrein per 10 8 washed and gel filtered platelets per ml. The activation of pro-UK by PPA-pretreated platelets was dose-dependent and inhibited by soybean trypsin inhibitor but not by bdellin, a specific inhibitor of plasmin, nor by the corn inhibitor of factor XIIa. Kinetic analysis of pro-UK activation by kallikrein showed promotion of the reaction by platelets. The KM of the reaction was reduced by platelets by ≈ 7-fold, while the kcat was essentially unchanged. In conclusion, PK was shown to be tightly associated with platelets where it can be activated by factor XIIa during clotting. The activation of pro-UK by platelet-bound kallikrein provides an explanation for the observed platelet mediated promotion of pro-UK-induced clot lysis. Since pro-UK and plasminogen have also been shown to be associated with platelets, the present findings suggest a mechanism by which the factor Xlla-dependent intrinsic pathway of fibrinolysis can be localized and targeted to a thrombus.

Identification of Promiscuous Nodulating Soybean Efficient in N2 Fixation 1

Crop Science ◽  
1985 ◽  
Vol 25 (4) ◽  
pp. 660-663 ◽  
Author(s):  
E. L. Pulver ◽  
E. A. Kueneman ◽  
V. Ranga‐Rao
Keyword(s):  
N2 Fixation

scholarly journals The Quorum Sensing Auto-Inducer 2 (AI-2) Stimulates Nitrogen Fixation and Favors Ethanol Production over Biomass Accumulation in Zymomonas mobilis

2021 ◽  
Vol 22 (11) ◽  
pp. 5628
Author(s):  
Valquíria Campos Alencar ◽  
Juliana de Fátima dos Santos Silva ◽  
Renata Ozelami Vilas Boas ◽  
Vinícius Manganaro Farnézio ◽  
Yara N. L. F. de Maria ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Quorum Sensing ◽  
Ethanol Production ◽  
N2 Fixation ◽  
Energy Demand ◽  
Zymomonas Mobilis ◽  
Biomass Accumulation ◽  
High Energy ◽  
Gram Negative ◽  
Expression Of Genes

Autoinducer 2 (or AI-2) is one of the molecules used by bacteria to trigger the Quorum Sensing (QS) response, which activates expression of genes involved in a series of alternative mechanisms, when cells reach high population densities (including bioluminescence, motility, biofilm formation, stress resistance, and production of public goods, or pathogenicity factors, among others). Contrary to most autoinducers, AI-2 can induce QS responses in both Gram-negative and Gram-positive bacteria, and has been suggested to constitute a trans-specific system of bacterial communication, capable of affecting even bacteria that cannot produce this autoinducer. In this work, we demonstrate that the ethanologenic Gram-negative bacterium Zymomonas mobilis (a non-AI-2 producer) responds to exogenous AI-2 by modulating expression of genes involved in mechanisms typically associated with QS in other bacteria, such as motility, DNA repair, and nitrogen fixation. Interestingly, the metabolism of AI-2-induced Z. mobilis cells seems to favor ethanol production over biomass accumulation, probably as an adaptation to the high-energy demand of N2 fixation. This opens the possibility of employing AI-2 during the industrial production of second-generation ethanol, as a way to boost N2 fixation by these bacteria, which could reduce costs associated with the use of nitrogen-based fertilizers, without compromising ethanol production in industrial plants.

scholarly journals Enzymatic mechanism of an RNA ligase from wheat germ.

1983 ◽  
Vol 258 (13) ◽  
pp. 8374-8383
Author(s):  
R C Schwartz ◽  
C L Greer ◽  
P Gegenheimer ◽  
J Abelson
Keyword(s):  
Wheat Germ ◽  
Rna Ligase ◽  
Enzymatic Mechanism

scholarly journals Nitrogen Pools in Tropical Plantations of N2-Fixing and Non-N2-Fixing Legume Trees under Different Tree Stand Densities

Nitrogen ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 86-98
Author(s):  
Kelly Nery Bighi ◽  
Ranieri Ribeiro Paula ◽  
Marcos Vinícius Winckler Caldeira ◽  
Diego Lang Burak ◽  
Eduardo de Sá Mendonça ◽  
...  
Keyword(s):  
N2 Fixation ◽  
Stand Density ◽  
N Accumulation ◽  
Biological N2 Fixation ◽  
Nitrogen Acquisition ◽  
Nitrogen Pools ◽  
Acquisition Strategies ◽  
Tropical Plantations ◽  
Schizolobium Parahyba ◽  
Slow Growing

We investigated the nitrogen pools in monocultures of legume species widely used in reforestation in Brazil that have contrasting growth and nitrogen acquisition strategies. The plantations were established with the slow-growing and N2-fixing tree Anadenanthera peregrina var. peregrina, and the fast-growing and non-fixing tree Schizolobium parahyba var. amazonicum. The measurements of N pools in the tree biomass and the soil followed standard methods and were carried out on 54 experimental plots. The N2 fixation pools were evaluated by abundance natural of 15N and the N accretion methods. The soil N content was of similar magnitude between species and stand densities. The species showed similar amounts of N in the biomass, but divergent patterns of N accumulation, as well as the 15N signature on the leaves. S. parahyba accumulated most N in the stem, while A. peregrina accumulated N in the roots and leaves. However, the N accumulation in biomass of A. peregrina stand was less constrained by environment than in S. parahyba stands. The percentage of N derived from N2 fixation in A. peregrina stands decreased with the increase of stand density. The biological N2 fixation estimates depended on the method and the response of tree species to environment.

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