Interaction of Self-Sustained Pulses in Tunnel-Diode Oscillator Lattices

A one-dimensional lattice in tunnel-diode (TD) oscillators supports self-sustained solitary pulses resulting from the balance between gain and attenuation. By applying the reduction theory to the device’s model equation, it is found that two relatively distant pulses moving in the lattice are mutually affected by a repulsive interaction. This property can be efficiently utilized in equalizing pulse positions to achieve jitter elimination. In particular, when two pulses rotate in a small, closed lattice, they separate evenly at the asymptotic limit. As a result, the lattice loop can provide an efficient platform to obtain low-phase-noise multiphase oscillatory signals. In this work, the interaction between two self-sustained pulses in a TD-oscillator lattice is examined, and the properties of interpulse interaction are validated by conducting several measurements using a test breadboarded lattice.

MnS/FeS2 heterostructure with high-degree lattice match anchored into carbon skeleton for ultrastable sodium-ion storage

In this work, a heterostructure between MnS and FeS2 featuring identical cubic system and closed lattice parameters confined in one dimensional carbon nanofibers was synthesized through electrospinning technology (denoted as...

Structural state recognition facilitates tip tracking of EB1 at growing microtubule ends

The microtubule binding protein EB1 specifically targets the growing ends of microtubules in cells, where EB1 facilitates the interactions of cellular proteins with microtubule plus-ends. Microtubule end targeting of EB1 has been attributed to high-affinity binding of EB1 to GTP-tubulin that is present at growing microtubule ends. However, our 3D single-molecule diffusion simulations predicted a ~ 6000% increase in EB1 arrivals to open, tapered microtubule tip structures relative to closed lattice conformations. Using quantitative fluorescence, single-molecule, and electron microscopy experiments, we found that the binding of EB1 onto opened, structurally disrupted microtubules was dramatically increased relative to closed, intact microtubules, regardless of hydrolysis state. Correspondingly, in cells, the blunting of growing microtubule plus-ends by Vinblastine was correlated with reduced EB1 targeting. Together, our results suggest that microtubule structural recognition, based on a fundamental diffusion-limited binding model, facilitates the tip tracking of EB1 at growing microtubule ends.

Structural state recognition facilitates tip tracking of EB1 at growing microtubule ends in cells

The microtubule binding protein EB1 specifically targets the growing ends of microtubules in cells, where EB1 facilitates the interactions of cellular proteins with microtubule plus-ends. Microtubule end targeting of EB1 has been attributed to high affinity binding of EB1 to GTP-tubulin that is present at growing microtubule ends. However, our 3D single-molecule diffusion simulations predicted a ∼6000% increase in EB1 arrivals to open, tapered microtubule tip structures relative to closed lattice conformations. Using quantitative fluorescence, single-molecule, and electron microscopy experiments, we found that the binding of EB1 onto opened, structurally disrupted microtubules was dramatically increased relative to closed, intact microtubules, regardless of hydrolysis state. Correspondingly, in cells, the conversion of growing microtubule ends from a tapered into a blunt configuration resulted in reduced EB1 targeting. Together, our results suggest that microtubule structural recognition, based on a fundamental diffusion-limited binding model, facilitates the tip tracking of EB1 at growing microtubule ends.

Coura and Valença Bridges on Minho Railway line – old structures, updated performance

<p>The pleasant Minho railway single lane line section from Caminha to Valença crosses the Minho river at Valença, through a very interesting and beautiful steel bridge. At Caminha it crosses the river Coura, by an also attractive steel bridge. Both are more than a century old and were refurbished and upgraded in a recent past and had before severe speed restrictions and load limitations:</p><ol><li> <p>Coura bridge: This 1879 iron bridge is a 3 span 164m lower deck continuous closed lattice girder, for a live load of only 4t/m without dynamic effects allowance. It was totally supported by a new continuous steel arch bridge, so both work together, combining in a very elegant construction.</p></li><li> <p>Valença bridge: This double-deck 1886 bridge is a steel 5 span 333m continuous lattice girder. Pathologies like excessive bending on the columns top sections, changing inappropriate bearing and a lock-up system for the braking action resulted in a demanding but discrete reinforcement.</p></li></ol>