DJD is a common disease of domesticated cats that requires further investigation of its associated clinical signs.

No abstract

The current imbalance in the biogeochemical cycle of nitrogen is as serious as that of carbon. One way to mitigate this problem is through the electrochemical reduction of nitrates under mild conditions, which is an appealing though not fully understood process. Therefore, deeper insight into the electrocatalytic reaction mechanism is needed to optimize this process. Here we thoroughly analyse the adsorption energy of nitrate with DFT calculations on various surface facets of pure Au, Ag, and their near-surface and surface alloys, as the adsorption and subsequent reduction of nitrate are thought to be rate limiting in the electrocatalytic reaction. The observed systematic trends allow prediction of the surface with highest electrocatalytic activity for the reduction of nitrate. This prediction was verified experimentally by depositing sub-monolayer amounts of Ag on polycrystalline Au electrodes. We observe a well-defined volcano curve which correlates the amount of Ag deposited on the surface with the current density at a fixed potential, with the peak activity around 2/3 ML Ag surface coverage. The electrocatalytic activity and stability of the bimetallic Ag-Au systems, found through the interplay of theoretical modelling and empirical observations, serve as a clear example for the rational design of novel catalytic materials and confirm the key role that the adsorption of nitrate plays in the overall nitrate reduction rate.

The dinuclear RuII arene complexes [{(eta6-arene)RuCl}2(mu-2,3-dpp)](PF6)2, arene=indan (1), benzene (2), p-cymene (3), or hexamethylbenzene (4) and 2,3-dpp=2,3-bis(2-pyridyl)pyrazine, have been synthesized and characterized. Upon irradiation with UVA light, complexes 1 and 2 readily underwent arene loss, while complexes 3 and 4 did not. The photochemistry of 1 was studied in detail. In the X-ray structure of [{(eta6-indan)RuCl}2(mu-2,3-dpp)](PF6)2 (1), 2,3-dpp bridges two RuII centers 6.8529(6) A apart. In water, aquation of 1 in the dark occurs with replacement of chloride with biexponential kinetics and decay constants of 100+/-1 min-1 and 580+/-11 min-1. This aquation was suppressed by 0.1 M NaCl. UV or visible irradiation of 1 in aqueous or methanolic solution led to arene loss. The fluorescence of the unbound arene is approximately 40 times greater than when it is complexed. Irradiation of 1 also had a significant effect on its interactions with DNA. The DNA binding of 1 is increased after irradiation. The non-irradiated form of 1 preferentially formed DNA adducts that only weakly blocked RNA polymerase, while irradiation of 1 transformed the adducts into stronger blocks for RNA polymerase. The efficiency of irradiated 1 to form DNA interstrand cross-links was slightly greater than that of cisplatin in both 10 mM NaClO4 and 0.1 M NaCl. In contrast, the interstrand cross-linking efficiency of non-irradiated 1 in 10 mM NaClO4 was relatively low. An intermediate amount of cross-linking was observed when the sample of DNA already modified by non-irradiated 1 was irradiated. DNA unwinding measurements supported the conclusion that both mono- and bifunctional adducts with DNA can form. These results show that photoactivation of dinuclear RuII arene complexes can simultaneously produce a highly reactive ruthenium species that can bind to DNA and a fluorescent marker (the free arene). Importantly, the mechanism of photoreactivity is also independent of oxygen. These complexes, therefore, have the potential to combine both photoinduced cell death and fluorescence imaging of the location and efficiency of the photoactivation process.