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| Live from the Labs cnrs I international w 12 magazine Gif-sur-Yvette The Buzz on Bee Bites By Fui Lee Luk w While domestic honeybees are notorious for their sting, far less is known about their bite. Greek and Cypriot biologists, along with CNRS researchers from the LEGS,1 have discovered that when bees bite their victims, they transfer a nifty local anesthetic with amazing medicinal potential.2 Doubt has long clouded the role of the 2-heptanone (2-H) secreted by the bee’s mandibular glands, thought to alert nest mates to threats or mark flowers already visited. The new study provides an unexpected answer: given its anesthetic properties, the compound can knock out hive intruders for up to 9 minutes, enough time to be pushed out of bee nests. Alexandros P apachristoforou of the University of Thessaloniki and Gérard A rnold of the LEGS stumbled on the find while assessing the possible effect q SEM scan of a honeybee mandible of 2-H on wax moth larvae. Fitted with motiontracking showing the pore (P) from which 2-H electrical probes, these common beehive is secreted. Contact information: pests stopped moving when bitten by honeybees or injected with 2-H. A nalysis of bee morphology and anatomy shows that bees control their mandibular muscles to administer 2-H when they bite. “The tactic went long undetected, since the bite is not strong enough to injure most enemies,” notes A rnold, “but it is effective on threats that are too small to be stung, including the parasitic mite Varroa destructor.” Disabling for tiny vermin, 2-H can act as a balm for other organisms, as highlighted when compared with the common anesthetic lidocaine. Testing both substances on insects (wax moth larvae) and mammalian tissues (hamster ovary and rat sciatic nerve samples), the team showed that 2-H works like lidocaine, by blocking sodium ions from flowing through cells, hence deactivating nerve impulses. A lready patented for pharmaceutical applications, 2-H—a natural product deemed a harmless food additive—seems less toxic than the synthetic lidocaine, markedly boosting its prospects for use in human and animal remedies. 01. Laboratoire évolution, génomes, spéciation (CNRS). 02. A . P apachristoforou et al., “The bite of the honeybee: 2-heptanone secreted from honeybee mandibles during a bite acts as a local anaesthetic in insects and mammals,” PLoS ONE, 2012. 7(10): e47432. Biology First Single-Molecule Motor BY Fui Lee Luk w It took 10 years of research and the development of a complex 15-step synthesis method for an international team1 involving CNRS’s CEMES2 to build the world’s smallest molecular motor.3 Under two nanometers in diameter, it is the smallest-ever single molecule capable of transforming energy into step-by-step reversible rotational movement, using a Scanning Tunneling Microscope (STM) both as an observation tool and an energy source. CEMES researchers Christian Joachim and Gwenaël Rapenne call it the “first genuine molecule motor, as its rotational capacity depends on the molecule itself and not on its contact with a specific surface or solution.” Totalling a mere 200 atoms, the cutting-edge design comprises three parts: a tripod-like stator attached to a gold surface that keeps the motor stable; a five-blade rotor, with one blade shorter to show the direction of rotation; and finally a ball bearing made up of a single ruthenium atom linking the static and rotational parts. The new motor breaks ground by rotating clockwise and anticlockwise at will. To achieve this, the experiment was performed at –268.5°C, a temperature at which the rotor stops turning freely. Motion is then prompted by electrons “tunneling” from the tip of the microscope through the motor. The energy lost by electrons during the process causes vibrations that drive the rotor’s movement. By aiming the STM’s tip at a given blade, the scientists are able to control the rotor’s direction, step by step. It is the first time that rotor direction can be controlled when using STM to propel motors. The team’s next challenge is to measure the nanomotor’s motive power by LEGS , Gif-sur-Yvette. Gérard Arnold > gerard.arnold@legs.cnrs-gif.fr fitting it with minuscule solid-state gears, and to optimize this power by modifying the molecule’s chemical composition. Nanometric in size, this motor has a great future in nanorobots or nanovehicles— also being developed by the CEMES. 01. Université de Toulouse (France), Ohio University (US), and Singapore’s Institute of Materials Research and Engineering (Singapore). 02. Centre d’élaboration de matériaux et d’études structurales (CNRS). 03. U.G.E. P erera et al., “Controlled clockwise and anticlockwise rotational switching of a molecular motor,” Nature Nanotechnology, 2013. 8: 46-51. Nanotechnology q The blade of the molecule motor (yellow) rotates on its axis in either direction, depending on where the tip of the STM (e) is aimed. Contact information: CEMES , Toulouse. Christian Joachim > christian.joachim@cemes.fr Toulouse © P apachristoforou et al © G. Rapenne et G. Vives , CEMES, CNRS/UPS P


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