ABSTRACT
Long-distance entanglement distribution is essential for both foundational tests of quantum physics and scalable quantum networks. Owing to channel loss, however, the previously achieved distance was limited to ~100 kilometers. Here we demonstrate satellite-based distribution of entangled photon pairs to two locations separated by 1203 kilometers on Earth, through two satellite-to-ground downlinks with a summed length varying from 1600 to 2400 kilometers. We observed a survival of two-photon entanglement and a violation of Bell inequality by 2.37 ± 0.09 under strict Einstein locality conditions. The obtained effective link efficiency is orders of magnitude higher than that of the direct bidirectional transmission of the two photons through telecommunication fibers.
ABSTRACT
Acetylcholinesterase (AChE; EC3.1.1.7) is well known for its role in the hydrolysis of acetylcholine at cholinergic synapses to terminate neurotransmission. In addition to its synaptic presence, AChE has been found to be in non-cholinergic cells such as hematopoietic and osteogenic cells. We have recently reported that AChE is expressed in various cells undergoing apoptosis. To characterize AChE in apoptotic cells and to investigate the role of AChE expression in apoptosis, we devised a method to purify AChE expressed in apoptotic human lung fibroblast cell line HLF. The isolation of this enzyme is mainly based on inhibitor ligand affinity chromatography using immobilized tacrine. However, this method is only effective in isolating active AChE. Here we employed antibody-based chromatography and found that both active and inactive AChE were present in apoptotic HLF cells. Active AChE was predominantly observed in the nuclei of apoptotic cells, while inactive AChE was mainly present in the cytoplasm. Therefore, our method provides an opportunity to investigate further the role of AChE, especially inactive AChE, in apoptosis.
