Kinetics and mechanism of the hydrogen-evolution reaction on mercury in HCl-dimethylsulphoxide solutions

Rapid galvanostatic and potentiostatic stationary E/I curves, E/time characteristics at current interruption and electrode capacitance measurements were made to investigate hydrogen-ion discharge on mercury in HCl-DMSO solutions, with and without the addition of LiCl as supporting electrolyte. Kinetic parameters and their temperature and concentration dependences are discussed in terms of the initial electron-trnsfer reaction as rate-determining.     

Electrode behaviour of nickel in HCl-dimethylsulphoxide solutions—I. The cathodic evolution of hydrogen

The electrochemical reduction of the solvated hydrogen ion dissolved in DMSO as HCl was investigated from 25 to 45°C, at different concentrations and ionic strength. Stationary and non-stationary techniques were employed to obtained the kinetic parameters. The results were interpreted with a reaction scheme involving an initial electron transfer as rds, probably followed by an electrochemical desorption step.     

Engineered Neutral Phosphorous Dendrimers Protect Mouse Cortical Neurons and Brain Organoids from Excitotoxic Death

Nanoparticles are playing an increasing role in biomedical applications. Excitotoxicity plays a significant role in the pathophysiology of neurodegenerative diseases, such as Alzheimer’s or Parkinson’s disease. Glutamate ionotropic receptors, mainly those activated by N-methyl-D-aspartate (NMDA), play a key role in excitotoxic death by increasing intraneuronal calcium levels; triggering mitochondrial potential collapse; increasing free radicals; activating caspases 3, 9, and 12; and inducing endoplasmic reticulum stress. Neutral phosphorous dendrimers, acting intracellularly, have neuroprotective actions by interfering with NMDA-mediated excitotoxic mechanisms in rat cortical neurons. In addition, phosphorous dendrimers can access neurons inside human brain organoids, complex tridimensional structures that replicate a significant number of properties of the human brain, to interfere with NMDA-induced mechanisms of neuronal death. Phosphorous dendrimers are one of the few nanoparticles able to gain access to the inside of neurons, both in primary cultures and in brain organoids, and to exert pharmacological actions by themselves.     

A comparative study of the effect of some paraffinic oils on rheological and dynamic properties and behavior at low temperature in EPDM rubber compounds

The influence of some paraffinic oils on rheological properties, dynamic properties, and behavior at low temperature of various ethylene–propylene–diene monomer rubber (EPDM) compounds was studied. Three different types of EPDM, Dutral TER 4049, Dutral Ter 4038, and Nordel IP 4770 R, and five different paraffinic oils were used. The properties of the compounds were evaluated with reference to the oil characteristics: viscosity, composition, glass transition temperature, and solubility parameter. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1825–1834, 2005     

Kinetics and mechanism of the anodic dissolution of nickel in HCl-dimethylsulphoxide solutions

The anodic dissolution of nickel in HCl-DMSO solutions containing different supporting electrolytes has been studied between 20–40°C. The electrodissolution and electrodeposition are predominantly activated electrode processes. At high anodic potentials and in the presence of perchlorate ions at high concentration passivation sets in.A probable reaction pathway is postulated which explains most of the experimental findings. Passivation corresponds to a salt precipitation-dissolution process at the electrode vicinity.     

Deposition and stripping processes of tin on gold film electrodes studied by surface conductance

The CV and surface conductance (SC) responses of tin species adsorbed on evaporated gold film electrodes were studied as a function of the potential window and the potential sweep rate. Sn adatoms were generated either, by reducing Sn(II) present in the solution (u p d) or by first irreversibly adsorbing Sn(II) and then reducing it in the supporting electrolyte alone. The experimental results show that at potentials about E ≈ −0.25 V(versus SCE), all the Sn(II) is reduced to Sn(0) and this species is adsorbed on the electrode surface. The subsequent oxidation of Sn(0) leads to Sn(II)_ad, adsorbed on the electrode. This species desorbs only when the Sn(II)_ad is further oxidised to soluble Sn(IV). The number of electrons involved in the reduction of Sn(II) to Sn(0) and vice versa is two. On the other hand, the analysis of the resistance measurements at low coverage is made by applying the surface Linde's rule. This leads to the conclusion that the Sn(0) behaves as an interstitial impurity. SC experiments, made in the potential region corresponding to Sn bulk deposition, suggest the formation of a bulk Sn–Au alloy.     

CETP and LCAT Gene Polymorphisms Are Associated with High‐Density Lipoprotein Subclasses and Acute Coronary Syndrome

We evaluated whether CETP and LCAT gene polymorphisms are statistically associated with the high‐density lipoprotein (HDL) size distribution, the cholesterol level of HDL subclasses, and the acute coronary syndrome (ACS) susceptibility. Two CETP gene polymorphisms (rs4783961 and rs708272) and one LCAT polymorphism (rs2292318) were genotyped by 5′ exonuclease TaqMan assays in 619 patients with ACS and 607 control individuals. For HDL analysis, a subgroup of 100 healthy individuals was recruited; the HDL subclasses were separated via ultracentrifugation and polyacrylamide gradient gel electrophoresis under native conditions. Under a dominant model, the G allele of the rs708272 polymorphism was associated with an increased risk of ACS (odds ratios [OR] = 1.45, corrected p‐value [pC_Dom] = 0.036). The linkage disequilibrium analysis showed that one of the eight possible combinations was associated with the risk of developing ACS (OR = 1.52, pC = 0.02), which suggests that it may contribute to coronary atherosclerosis. The rs708272 G allele carriers had a lower concentration of cholesterol associated with the HDL2a and HDL3a subclasses when compared with subjects carrying the A allele. Carriers of LCAT rs2292318 A allele showed a lower concentration of high‐density lipoprotein‐cholesterol (HDL‐C) in comparison to the GG genotype; the cholesterol associated with the each one of the five HDL subclasses was significantly lower in rs2292318 A than in GG subjects. In summary, this study demonstrates that the rs708272 polymorphism is associated with a heightened risk of developing ACS. In addition, we report the association of the rs708272 and rs2292318 polymorphisms with HDL‐C levels and HDL subclasses.