We present a joint experimental and theoretical study on the desolvation of Ba(+) cations in (4)He nanodroplets excited via the 6p ← 6s transition. The experiments reveal an efficient desolvation process yielding mainly bare Ba(+) cations and Ba(+)Hen exciplexes with n = 1 and 2. The speed distributions of the ions are well described by Maxwell-Boltzmann distributions with temperatures ranging ...

Upon depolarization, many voltage-gated potassium channels undergo a time-dependent decrease in conductance known as inactivation. Both entry of channels into an inactivated state and recovery from this state govern cellular excitability. In this study, we show that recovery from slow inactivation is regulated by intracellular permeant cations. When inactivated channels are hyperpolarized, clos...

The reactions of small gold cluster cations Au(x)(+) (x=2-6) with CH(4) were studied by joint gas-phase kinetics and first-principles density functional theory calculations. The experimentally obtained temperature-dependent low pressure rate constants were analyzed by employing the Lindemann energy transfer model for association reactions in conjunction with statistical RRKM theory. In this way...

The selective preference of Chlorella pyrenoidosa for alkali metal cations was found to have the order Rb > K > > > Na. It was demonstrated that a cation of higher preference can replace in the cell cations of lower preference by an ion interchange process.The replacement of Na from the cell by K or Rb occurred against high external Na concentrations up to 450 meq/1 Na.It is suggested that the ...

The membrane response to mechanical stimulation was investigated under voltage-clamp conditions in the hypotrich ciliate Stylonychia mytilus (Protozoa). The mechanoreceptor current shows high ionic selectivity, unlike than in metazoans. It is exclusively carried by potassium ions and is selectively inhibited by tetraethylammonium and 4-aminopyridine. Procaine, tetramethylammonium, caesium and d...

This study evaluates the impact of high-skilled immigrants on US technology formation. Speci…cally, we use reduced-form speci…cations that exploit large changes in the H-1B visa program. Fluctuations in H-1B admissions levels signi…cantly in‡uence the rate of Indian and Chinese patenting in cities and …rms dependent upon the program relative to their peers. Most speci…cations …nd weak crowding-...

Large-scale density functional theory calculations (DFT) found various types of binding of an unsaturated hydrocarbon (C2H2 and C2H4) to a ZSM-5 zeolite extraframework copper cation. We employed the DFT calculations based on the B3LYP functional to obtain local minima of an unsaturated hydrocarbon adsorbed on one or two copper cations embedded inside ZSM-5, and then compared their stabilization...

In a combined experimental and theoretical study, we show that capacitive charging of porous electrodes in multicomponent electrolytes may lead to the phenomenon of time-dependent ion selectivity of the electrical double layers (EDLs) in the electrodes. This effect is found in experiments on capacitive deionization of water containing NaCl/CaCl(2) mixtures, when the concentration of Na(+) ions ...

increasing urbanisation and industrialisation have led to a dramatic reduction in forest area, and now only culturally protected remnants of natural forests and some new plantations remain in most areas of the north of iran. to investigate the status of the chemical and physical characteristics of soil under these remnant forests and assess the possible impacts of reforestation on soil properti...