Solvent-Dependent Photophysics and Reactivity of Monomeric and Dimeric 4-Amino-1,8-Naphthalimides.

The solvent-dependent photophysics of two 4-amino-substituted 1,8-naphthalene imides (AIs) were studied using fluorescence spectroscopy and laser flash photolysis. The compounds were functionalized with water-soluble 2,2'(ethylenedioxy) diethylamine groups, yielding a monomer (AI3) and a dimer (AI4). The radiative and nonradiative singlet-state deactivation processes of AI3 and AI4 were quantified in 10 solvents and at different pH values. The fluorescence quantum yield for the AI4 dimer in water was more than 100× lower than in other solvents, or for the monomeric AI3. The enhanced nonradiative decay of aqueous solutions of dimeric AI4 is accompanied by biexponential decay kinetics, suggesting equilibration with a dark excited state. An oxygen-quenchable triplet state (T1) of AI3 was produced upon 416 nm excitation in both water and n-octanol. In water, the T1 state evolved into a long-lived transient that was unreactive toward oxygen or several electron donors. This species was not observed in n-octanol. The transient observed upon 416 nm excitation of AI4 in water was extremely weak. However, production of T1 in both AI3 and AI4 was evidenced by the photoinduced electron transfer to methyl viologen, albeit in low quantum yield (0.0503 and 0.00778 for AI3 and AI4, respectively). The photophysics and reactivity are consistent with the production of an intramolecular charge transfer (ICT) state that is stabilized in water. Significantly, this stabilization enhances nonradiative decay pathways, particularly in the AI4 dimer. The results indicate that the photochemistry of these compounds can be environmentally mediated, switching from radical- to triplet-initiated processes.

Nail Bed Reconstruction Using Single-Layer Bovine Acellular Dermal Matrix.

Traumatic nail bed injuries to the hand are a common problem for hand surgeons. Whereas the majority of those are treated with primary repair, the remainder present significant surgical challenges to address residual soft tissue defects. In this article, we present our approach to treating injuries to the fingertips utilizing single-layer bovine acellular dermal matrix grafts.

Reliability of focal identification of motor fascicles of the ulnar nerve proximal to the wrist: an anatomical study.

We investigated whether motor fascicles of the ulnar nerve can be reliably identified proximal to the wrist. In 17 cadaveric upper limbs, the anterior interosseous nerve was transected at its arborization in the pronator quadratus and transposed to the palmar aspect of the ulnar nerve. The motor fascicular bundle was identified at this level after distinguishing the intraneural epineural involution by microsurgical probing. The motor branch was identified in Guyon's canal and traced retrograde via intraneural dissection to assess accuracy of the original identification. The motor fascicular bundle was found to have been correctly identified in all specimens. We conclude that local anatomic landmarks allow for the motor fascicular group to be correctly identified. Therefore, retrograde, internal dissection of the ulnar nerve is not likely to be required for reliable transfer of anterior interosseous nerve to ulnar nerve motor fascicles.

The circle of life: A cross-cultural comparison of children's attribution of life-cycle traits.

Do children attribute mortality and other life-cycle traits to all minded beings? The present study examined whether culture influences young children's ability to conceptualize and differentiate human beings from supernatural beings (such as God) in terms of life-cycle traits. Three-to-5-year-old Israeli and British children were questioned whether their mother, a friend, and God would be subject to various life-cycle processes: Birth, death, ageing, existence/longevity, and parentage. Children did not anthropomorphize but differentiated among human and supernatural beings, attributing life-cycle traits to humans, but not to God. Although 3-year-olds differentiated significantly among agents, 5-year-olds attributed correct life-cycle traits more consistently than younger children. The results also indicated some cross-cultural variation in these attributions. Implications for biological conceptual development are discussed.

Cross-cultural similarities and differences in person-body reasoning: experimental evidence from the United Kingdom and Brazilian Amazon.

We report the results of a cross-cultural investigation of person-body reasoning in the United Kingdom and northern Brazilian Amazon (Marajó Island). The study provides evidence that directly bears upon divergent theoretical claims in cognitive psychology and anthropology, respectively, on the cognitive origins and cross-cultural incidence of mind-body dualism. In a novel reasoning task, we found that participants across the two sample populations parsed a wide range of capacities similarly in terms of the capacities' perceived anchoring to bodily function. Patterns of reasoning concerning the respective roles of physical and biological properties in sustaining various capacities did vary between sample populations, however. Further, the data challenge prior ad-hoc categorizations in the empirical literature on the developmental origins of and cognitive constraints on psycho-physical reasoning (e.g., in afterlife concepts). We suggest cross-culturally validated categories of "Body Dependent" and "Body Independent" items for future developmental and cross-cultural research in this emerging area.