Climate Effects on Subsoil Carbon Loss Mediated by Soil Chemistry.

Subsoils store at least 50% of soil organic carbon (SOC) globally, but climate change may accelerate subsoil SOC (SOC) decomposition and amplify SOC-climate feedbacks. The climate sensitivity of SOC decomposition varies across systems, but we lack the mechanistic links needed to predict system-specific SOC vulnerability as a function of measurable properties at larger scales. Here, we show that soil chemical properties exert significant control over SOC decomposition under elevated temperature and moisture in subsoils collected across terrestrial National Ecological Observatory Network sites.

Effects of season and interval of prescribed burns on pyrogenic carbon in ponderosa pine stands in the southern Blue Mountains, Oregon, USA.

In ponderosa pine () forests of the western United States, prescribed burns are used to reduce fuel loads and restore historical fire regimes. The season of and interval between burns can have complex consequences for the ecosystem, including the production of pyrogenic carbon (PyC). PyC plays a crucial role in soil carbon cycling, displaying turnover times that are orders of magnitude longer than unburned organic matter.

Modulation of amyloid-β aggregation by histidine-coordinating Cobalt(III) Schiff base complexes.

Oligomers of the Aβ42 peptide are significant neurotoxins linked to Alzheimer's disease (AD). Histidine (His) residues present at the N terminus of Aβ42 are believed to influence toxicity by either serving as metal-ion binding sites (which promote oligomerization and oxidative damage) or facilitating synaptic binding. Transition metal complexes that bind to these residues and modulate Aβ toxicity have emerged as therapeutic candidates.

Structural optimization of Zn(II)-activated magnetic resonance imaging probes.

We report the structural optimization and mechanistic investigation of a series of bioactivated magnetic resonance imaging contrast agents that transform from low relaxivity to high relaxivity in the presence of Zn(II). The change in relaxivity results from a structural transformation of the complex that alters the coordination environment about the Gd(III) center. Here, we have performed a series of systematic modifications to determine the structure that provides the optimal change in relaxivity in response to the presence of Zn(II).

Synthesis, Characterization, and in vitro Testing of a Bacteria-Targeted MR Contrast Agent.

A bacteria-targeted MR contrast agent, Zn-, consisting of two Zn-dipicolylamine (Zn-dpa) groups conjugated to a Gd chelate has been synthesized and characterized. In vitro studies with and show that Zn- exhibits a significant improvement in bacteria labeling efficiency vs. control.

Rational design of [Co(acacen)L2]+ inhibitors of protein function.

Cobalt(III) Schiff base complexes, such as [Co(acacen)L(2)](+), inhibit the function of Zn(II)-dependent proteins through dissociative exchange of the axial ligands with key histidine residues of the target protein. Consequently the efficacy of these compounds depends strongly on the lability of the axial ligands. A series of [Co(acacen)L(2)](+) complexes with various axial ligands was investigated using DFT to determine the kinetics and thermodynamics of ligand exchange and hydrolysis.

Strong coordination of tetraphenylborate anion to copper(I) bipyridine and phenanthroline-based complexes and its effect on catalytic activity in the cyclopropanation of styrene.

The synthesis, characterization, and cyclopropanation activity of tetrahedral copper(I) complexes with bipyridine- and phenanthroline-based ligands containing strongly coordinated tetraphenylborate anions are reported. Cu(I)(bpy)(BPh(4)), Cu(I)(phen)(BPh(4)), and Cu(I)(3,4,7,8-Me(4)phen)(BPh(4)) complexes are the first examples in which the BPh(4)(-) counterion chelates a transition metal center in bidentate fashion through eta(2) pi interactions with two of its phenyl rings.