Intermetallic Pd-Y nanoparticles/N-doped carbon nanotubes as multi-active catalysts for oxygen reduction reaction, ethanol oxidation reaction, and zinc-air batteries.

Intermetallic nanomaterials are unique in terms of their band gap, atomic-level arrangement, and well-defined stoichiometry, which allows them to exhibit significantly enhanced catalytic performance in electrochemical applications. However, the preparation of durable intermetallic catalysts with a lower content of platinum group metals is challenging, while the lack of control over the loss of active components limits their long-term application due to weak interaction between the support and the nanostructure. Here, we have designed the intermetallic alloyed nanoparticles (NPs) of PdY on N-doped carbon nanotubes (PdY/NCNTs) as a multifunctional catalyst for the oxygen reduction reaction (ORR), the ethanol oxidation reaction (EOR), and zinc-air batteries (ZABs).

Characteristic electronic perturbation by asymmetric arrangements of p-aminophenyl substituents in free-base porphyrins.

We have investigated the perturbed electronic properties of meso-substituted free-base porphyrins with symmetric and asymmetric arrangements of substituents using time-resolved spectroscopic measurements and theoretical calculations. The extent of electronic perturbation by substituents in meso-substituted porphyrins is mainly affected by the isoenergetic condition of frontier MOs of porphine and substituent units, nonorthogonal geometry, and geometrical arrangement of substituents. By using the asymmetric arrangements of p-aminophenyl and pentafluorophenyl substituents, we can induce the electron-rich condition on the porphine unit and the intramolecular charge transfer character in the excited state.

Electrocatalytic oxidation of formic acid by poly(diallyldimethylammonium chloride) and Pt/Pd-functionalized carbon nanotubes mixtures.

Improving the catalytic activity of the anode catalyst is an important task in the direct formic acid fuel cell (DFAFC). In this study, the catalysts were prepared by dispersing either platinum or palladium metal on the surface of thiolated multi-walled carbon nanotubes (t-MWCNTs), denoted as t-MWCNT-Pt and t-MWCNT-Pd, respectively. These modified t-MWCNT and poly(diallyldimethylammonium chloride) (PDDA) were ultrasonically mixed and loading on a glassy carbon electrode (GCE) for formic acid (FA) oxidation and the catalytic activities were then investigated by using cyclic voltammetry (CV) and chronoamperometry (CA) methods.

Comparison of intravitreal bevacizumab alone or combined with triamcinolone versus triamcinolone in diabetic macular edema: a randomized clinical trial.

Purpose: To compare the effect of an intravitreal injection of bevacizumab alone (IVB) or combined with triamcinolone (IVB/IVT) versus triamcinolone (IVT) in patients with diabetic macular edema (DME).

Methods: In this randomized three-arm clinical trial, eligible eyes were assigned randomly to one of the three study arms: the IVB group, 2 injections of 1.25 mg of bevacizumab with 6-week intervals; the IVB/IVT group, 1.

A lead(II)-selective PVC membrane based on a Schiff base complex of N,N'-bis(salicylidene)-2,6-pyridinediamine.

PVC membrane electrodes for lead ion based on N,N'-bis(salicylidene)-2,6-pyridinediamine as membrane carrier were prepared. Among their membranes, a membrane electrode (m-3) containing o-NPOE as a plasticizer and 50mol% additive displays an excellent Nernstian response (29.4mV/decade) and the limit of detection of -loga (M) = 6.

Nitrate-selective electrodes based on meso-tetrakis[(2-arylphenylurea)-phenyl]porphyrins as neutral lipophilic ionophores.

Polymeric-membrane electrodes for NO(3)(-) anion based on (alpha,alpha,alpha,alpha)-5,10,15,20-tetrakis [2-(4-methylphenylurea)phenyl]porphyrin I and similar urea-functionalized porphyrins II-IV as neutral ionophores were prepared. The effects of polymeric-membrane composition and test solution pH were tested. The electrodes revealed good selectivity coefficients for NO(3)(-) over a wide variety of other anions, and the values of eight anions were measured.