Light-Induced Charge Transfer from Transition-Metal-Doped Aluminum Clusters to Carbon Dioxide.

Charge transfer between molecules and catalysts plays a critical role in determining the efficiency and yield of photochemical catalytic processes. In this paper, we study light-induced electron transfer between transition-metal-doped aluminum clusters and CO2 molecules using first-principles time-dependent density-functional theory. Specifically, we carry out calculations for a range of dopants (Zr, Mn, Fe, Ru, Co, Ni, and Cu) and find that the resulting systems fall into two categories: Cu- and Fe-doped clusters exhibit no ground-state charge transfer, weak CO2 adsorption, and light-induced electron transfer into the CO2. In all other systems, we observe ground-state electron transfer into the CO2 resulting in strong adsorption and predominantly light-induced electron back-transfer from the CO2 into the cluster. These findings pave the way toward a rational design of atomically precise aluminum photocatalysts.

Motive Arousal Without Pictures? An Experimental Validation of a Hybrid Implicit Motive Test.

Pictures are widely used as stimuli in implicit motive tests. Hybrid forms of such tests present pictures and declarative statements underneath pictures. Some authors have argued that explicitly declaring agreement with motive-related statements presented underneath pictures might shift the validity of such tests from capturing less implicit motives to more explicit motives. If that is the case, pictures as elicitors of implicit motives might become less relevant. Adopting the views on validity presented by Borsboom, Mellenbergh, and van Heerden ( 2004 ) and Bornstein ( 2011 ), as well as item generation theory, we investigated whether the availability of pictures in hybrid motive tests causally affects test scores. To this end, we administered the Multi-Motive Grid (MMG; Sokolowski, Schmalt, Langens, & Puca, 2000 ), as an example of a hybrid motive test, either with or without pictures to 108 participants. Results revealed that the availability of pictures had no effect on 3 out of 6 test scores. Furthermore, eliminating pictures had only inconsistent effects on correlations with a test of explicit motives. We conclude that pictures might not unanimously elicit motives in implicit motive tests that use declarative statements as response options.

Cell side-specific sensitivities of intracellular Ca2+ stores for inositol 1,4,5-trisphosphate, cyclic ADP-ribose, and nicotinic acid adenine dinucleotide phosphate in permeabilized pancreatic acinar cells from mouse.

In pancreatic acinar cells hormonal stimulation leads to a cytosolic Ca(2+) wave that starts in the apical cell pole and subsequently propagates toward the basal cell side. We used permeabilized pancreatic acinar cells from mouse and the mag-fura-2 technique, which allows direct monitoring of changes in [Ca(2+)] of intracellular stores. We show here that Ca(2+) can be released from stores in all cellular regions by inositol 1,4,5-trisphosphate. Stores at the apical cell pole showed a higher affinity to inositol 1,4,5-trisphosphate (EC(50) = 89 nm) than those at the basolateral side (EC(50) = 256 nm). In contrast, cADP-ribose, a modifier of Ca(2+)-induced Ca(2+) release, and nicotinic acid adenine dinucleotide phosphate (NAADP) were able to release Ca(2+) exclusively from intracellular stores located at the basolateral cell side. Our data agree with observations that upon stimulation Ca(2+) is released initially at the apical cell side and that this is caused by high affinity inositol 1,4,5-trisphosphate receptors. Moreover, our findings allow the conclusion that in Ca(2+) wave propagation from the apical to the basolateral cell side observed in pancreatic acinar cells Ca(2+)-induced Ca(2+) release, modulated by cADP-ribose and/or NAADP, might be involved.