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1. Design of a minimal di-nickel hydrogenase peptide

   https://doi.org/10.1126/sciadv.abq1990  

   Timm, Jennifer; Pike, Douglas H.; Mancini, Joshua A.; Tyryshkin, Alexei M.; Poudel, Saroj; Siess, Jan A.; Molinaro, Paul M.; McCann, James J.; Waldie, Kate M.; Koder, Ronald L.; et al (March 2023, Science Advances)

   Thorp, Holden (Ed.)

   Ancestral metabolic processes involve the reversible oxidation of molecular hydrogen by hydrogenase. Extant hydrogenase enzymes are complex, comprising hundreds of amino acids and multiple cofactors. We designed a 13–amino acid nickel-binding peptide capable of robustly producing molecular hydrogen from protons under a wide variety of conditions. The peptide forms a di-nickel cluster structurally analogous to a Ni-Fe cluster in [NiFe] hydrogenase and the Ni-Ni cluster in acetyl-CoA synthase, two ancient, extant proteins central to metabolism. These experimental results demonstrate that modern enzymes, despite their enormous complexity, likely evolved from simple peptide precursors on early Earth. 

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2. Nickel nanoparticles set a new record of strength

   https://doi.org/10.1038/s41467-018-06575-6  

   Sharma, A.; Hickman, J.; Gazit, N.; Rabkin, E.; Mishin, Y. (October 2018, Nature Communications)

   Abstract Material objects with micrometer or nanometer dimensions can exhibit much higher strength than macroscopic objects, but this strength rarely approaches the maximum theoretical strength of the material. Here, we demonstrate that faceted single-crystalline nickel (Ni) nanoparticles exhibit an ultrahigh compressive strength (up to 34 GPa) unprecedented for metallic materials. This strength matches the available estimates of Ni theoretical strength. Three factors are responsible for this record-high strength: the large Ni shear modulus, the smooth edges and corners of the nanoparticles, and the thin oxide layer on the particle surface. This finding is supported by molecular dynamics simulations that closely mimic the experimental conditions, which show that the mechanical failure of the strongest particles is triggered by homogeneous nucleation of dislocation loops inside the particle. The nucleation of a stable loop is preceded by multiple nucleation attempts accompanied by unusually large local atomic displacements caused by thermal fluctuations. 

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3. The Role of Carbon Content: A Comparison of the Nickel Particle Size and Magnetic Property of Nickel/Polysiloxane‐Derived Silicon Oxycarbide

   https://doi.org/10.1002/adem.202201453  

   Yang, Ni; Zhang, Xuanyi; Reynolds, Lewis; Kumah, Divine; Xu, Chengying (January 2023, Advanced Engineering Materials)

   A facile and novel processable method to synthesize the Ni nanoparticles (Ni NPs) by tailoring their size in the matrix of the silicon oxycarbide (SiOC) ceramic system is reported. This method is based on polymer‐derived ceramics (PDCs), instead of the conventional powder route. The specific structural characteristics and magnetic properties of the various Ni NPs/SiOC composites as a function of carbon content are systematically investigated. The magnetic properties are experimentally investigated as a function of NP size and measurement temperature. It is demonstrated that the change in the size of Ni NPs (average from ≈4 to ≈ 19 nm) determines the magnetic nature of superparamagnetism. Zero‐field‐cooled (ZFC) and field‐cooled (FC) magnetization studies under magnetic fields of 100 Oe are performed. The saturatedMversusH(M–H) loops (saturation magnetization) increase and the coercivity decreases with the size reduction of Ni NPs. It is an indicator of the presence of superparamagnetic behavior and single‐domain NP for ceramic materials. 

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4. Distribution and Cycling of Nickel and Nickel Isotopes in the Pacific Ocean

   https://doi.org/10.1029/2024GL111115  

   Bian, X; Yang, S‐C; Raad, R J; Odendahl, C E; Lanning, N T; Sieber, M; Huang, K‐F; Fitzsimmons, J N; Conway, T M; John, S G (August 2024, Geophysical Research Letters)

   Abstract Nickel stable isotopes (δ⁶⁰Ni) provide insight to Ni biogeochemistry in the modern and past oceans. Here, we present the first Pacific Ocean high‐resolution dissolved Ni concentration and δ⁶⁰Ni data, from the US GEOTRACES GP15 cruise. As in other ocean basins, increases in δ⁶⁰Ni toward the surface ocean are observed across the entire transect, reflecting preferential biological uptake of light Ni isotopes, however the observed magnitude of fractionation is larger in the tropical Pacific than the North Pacific Subtropical Gyre. Such surface ocean fractionation by phytoplankton should accumulate isotopically lighter Ni in the deep Pacific, yet we find that North Pacific deep ocean δ⁶⁰Ni is similar to previously reported values from the deep Atlantic. Finally, we find that seawater dissolved δ⁶⁰Ni in regions with hydrothermal input can be either higher or lower than background deep ocean δ⁶⁰Ni, depending on vent geochemistry and proximity. 

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5. Heteroleptic nickel complexes of a bulky bis(carbene)borate ligand

   https://doi.org/10.1016/j.poly.2018.09.026  

   Martinez, Jorge L.; Lee, Wei-Tsung; Pink, Maren; Chen, Chun-Hsing; Smith, Jeremy M. (December 2018, Polyhedron)