Subjects: Optics >> Quantum optics submitted time 2023-02-19
Abstract: How migratory birds can find the right way in navigating over thousand miles is an intriguing question, which much interested researchers in both fields of biology and physics for centuries. There several putative proposals that sound intuitively plausible all remain contested so far because those hypothesis-models of magnetoreceptor to sense geomagnetic field need either extremely high sensitivity or humankind-like intelligence to guide. Here we explore theoretically that the birds can navigate to their destination through an entirely new scenario to sense the geomagnetic field. Our proposal is based on separate peaks of the resonance-fluorescence spectrum of a four-level system derived from the ferric sulfide cluster which exists in a protein complex (Drosophila CG8198) of migratory birds. As the separation of spectral peaks contains information about geomagnetic field at both current location and birthland, the change of such separation cues the bird to choose a right direction to move and double-resonance emerges once arrived the destination. Our theoretical mechanism can explain previous experiments on the disorientation of migratory birds caused by oscillating magnetic field naturally and more precisely. This work provides insight to explain migratory navigation and motivates possible manmade practical devices.
Peer Review Status:Awaiting Review
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2017-11-17
Abstract: A new chemical class of potent DPP-IV inhibitors has been structurally derived from our recently disclosed pyrrolopyrimidine scaffold by replacing cyanobenzyl with butynyl group. Systematic variations and structure-activity relationship studies have been conducted on the starting hit 51 (IC50= 0.46 μM). Consequently, compound 78 (IC50= 1.55 nM) was identified to be a potent, selective, and orally available lead, worth further evaluations and optimizations.
Peer Review Status:Awaiting Review
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2017-11-17
Abstract: The structural superposition of DPP-IV complex with Alogliptin and Linagliptin displayed a similar binding mode. The butynyl of Linagliptin and cyanobenzyl of Alogliptin occupy the S1 pocket which therefore could be mutually switched. Thus a pharmacophore hybridization of Alogliptin was initiated and led to a novel DPP-IV inhibitor 61. Though it did not exhibit desired activity (IC50= 0.2 礛), the butynyl compound acts as a lead compound triggered a following structural optimization. A novel series of potent DPP-IV inhibitors represented by compound 77 (IC50= 0.36 nM) were obtained with a robust pharmacokinetic profile and better in vitro and in vivo efficacy than Alogliptin.
Peer Review Status:Awaiting Review