A carbon nanotube (CNT) synapse emulates a biological synapse with its dynamic logic, learning, and memory functions induced by the interactions between CNTs and hydrogen ions in an electrochemical cell. A circuit of CNT synapses operates with extremely low-energy consumption and could potentially emulate the functions of the neuronal network.

Melittin is the main component in the venom of the honey bee (Apis mellifera). It has multiple effects including antibacterial, antiviral, and anti-inflammatory activities in various cell types. However, the anti-inflammatory mechanisms of melittin have not been elucidated in Propionibactierium acnes (P. acnes)-induced keratinocyte or inflammatory skin disease animal models. In this study, we examined the effects of melittin on the production of inflammatory cytokines in heat-killed P. acnes-induced HaCaT cells. Heat-killed P. acnes-treated keratinocytes increased the expression of pro-inflammatory cytokines and Toll-like receptor 2. However, melittin treatment significantly suppressed the expression of these cytokines through regulation of the NF-κB and MAPK signaling pathways. Subsequently, the living P. acnes (1 × 10(7) CFU) were intradermally injected into the ear of mice. Living P. acnes-injected ears showed cutaneous erythema, swelling, and granulomatous response at 24 hours after injection. However, melittin-treated ears showed markedly reduced swelling and granulomatous responses compared with ears injected with only living P. acnes. These results demonstrate the feasibility of applying melittin for the prevention of inflammatory skin diseases induced by P. acnes.

We report an analog neuromorphic module composed of p-type carbon nanotube (CNT) synapses and an integrate-and-fire (I&F) circuit. The CNT synapse has a field-effect transistor structure with a random CNT network as its channel and an aluminum oxide dielectric layer implanted with indium ions as its gate. A positive voltage pulse (spike) applied on the gate attracts electrons into the defect sites of the gate dielectric layer, and the trapped electrons are gradually released after the pulse is removed. The electrons modify the hole concentration and induce a dynamic postsynaptic current in the CNT channel. Multiple input spikes induce excitatory or inhibitory postsynaptic currents via excitatory or inhibitory CNT synapses, which flow toward an I&F circuit to trigger output spikes. The dynamic transfer function between the input and output spikes of the neuromorphic module is analyzed. The module could potentially be scaled up to emulate biological neural networks and their functions.

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We have fabricated light-emitting diodes with a transparent doping layer on silicon nanocrystals (nc-Si) embeded in silicon nitride matrix formed by plasma-enhanced chemical vapor deposition. Under forward biased condition, orange electroluminescence (EL) with its peak wavelength at about 600 nm was observed at room temperature. The peak position of the EL is very similar to that of the photoluminescence (PL) and the emitted EL intensity is proportional to the current density passing through the device. We suggest that the observed EL is originated from electron-hole pair recombination in nc-Si. By using indium tin oxide and n-type SiC layer combination as a transparent doping layer, we obtained high external quantum efficiency greater than 1.6%.

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