ATRP catalysts of tetradentate guanidine ligands - do guanidine donors induce a faster atom transfer?

Tripodal tetradentate N donor ligands stabilise the most active ATRP catalyst systems. Here, we set out to synthesise the new guanidine ligand TMG-4NMeuns-penp, inspired by -substituted tris(2-pyridylmethyl)amine (TPMA) ligands. The impact of changing pyridine against guanidine donors was examined through solid state and solution experiments and density functional theory (DFT) calculations.

The bridge towards a more stable and active side-on-peroxido (Cu(µ-η:η-O)) complex as a tyrosinase model system.

A novel dinucleating bis(pyrazolyl)methane ligand was developed for tyrosinase model systems. After ligand synthesis, the corresponding Cu(I) complex was synthesized and upon oxygenation, formation of a µ-η:η peroxido complex could be observed and monitored using UV/Vis-spectroscopy. Due to the high stability of this species even at room temperature, a molecular structure of the complex could be characterized single-crystal XRD.

Formate complexes of tri- and tetravalent titanium supported by a tris(phenolato)amine ligand.

Titanium(III) and titanium(IV) formate complexes supported by the sterically encumbering tris(phenolato)amine ligand (H(ON) = tris(4,6-di--butyl-2-hydroxybenzyl)amine) are described. Salt metathesis of the chlorido precursor [(ON)TiCl] (1-Cl) with sodium formate in a 2 : 1 ratio in THF gave a dimer of sodium dititanium triformate units with 12-membered ring [Na{(ON)Ti}(μ-OCHO-η:η')] (3-Na) when crystallized from acetonitrile. Complex 3-Na was also prepared by reacting the previously reported terminal formate complex [(ON)Ti(OCHO)] (2) with excess sodium formate.

Understanding the structure-activity relationship and performance of highly active novel ATRP catalysts.

Copper bromide complexes based on a series of substituted guanidine-quinolinyl and -pyridinyl ligands are reported. The ligand systems were chosen based on the large variation with regard to their flexibility in the backbone, different guanidine moieties and influence by electron density donating groups. Relationships between the molecular structures and spectroscopic and electronic properties are described.

Evaluation of eye metrics as a detector of fatigue.

Objectives: This study evaluated oculometrics as a detector of fatigue in Air Force-relevant tasks after sleep deprivation. Using the metrics of total eye closure duration (PERCLOS) and approximate entropy (ApEn), the relation between these eye metrics and fatigue-induced performance decrements was investigated.

Background: One damaging effect to the successful outcome of operational military missions is that attributed to sleep deprivation-induced fatigue.

Mutual regulation of hypoxia-inducible factor and mammalian target of rapamycin as a function of oxygen availability.

The mammalian target of rapamycin (mTOR) regulates cellular growth and proliferation, mainly by controlling cellular translation. Most tumors show constitutive activation of the mTOR pathway. In hypoxia, mTOR is inactivated, which is believed to be part of the program of the cell to maintain energy homeostasis.

Alertness management strategies for operational contexts.

This review addresses the problem of fatigue (on-the-job-sleepiness) attributable to sleep loss in modern society and the scientifically proven strategies useful for reducing fatigue-related risks. Fatigue has become pervasive because many people work non-standard schedules, and/or they consistently fail to obtain sufficient sleep. Sleep restriction, sleep deprivation, and circadian desynchronization produce a variety of decrements in cognitive performance as well as an array of occupational and health risks.

Generating performance test batteries relevant to specific operational tasks.

The present review focuses on the development of a performance battery generation system that selects performance tests most applicable to particular jobs. First, a list or taxonomy of cognitive and performance skills that are involved in real-world jobs or missions is developed. Based on this list, an "armory" of performance tests probing those skills is identified.