Single-shot observation of nonlinear pulse splitting in a Kerr medium.

We report single-shot, time-resolved observation of self-steepening and temporal splitting of near-infrared, 50 fs, micro-joule pulses propagating nonlinearly in flint (SF11) glass. A coherent, smooth-profiled, 60-nm-bandwidth probe pulse that propagated obliquely to the main pulse through the Kerr medium recorded a time sequence of longitudinal projections of the main pulse's induced refractive index profile in the form of a phase-shift "streak," in which frequency-domain interferometry recovered with ∼10 fs temporal resolution. A three-dimensional simulation based on a unidirectional pulse propagation equation reproduced observed pulse profiles.

Novel 3D Neuron Regeneration Scaffolds Based on Synthetic Polypeptide Containing Neuron Cue.

Neural tissue engineering has become a potential technology to restore the functionality of damaged neural tissue with the hope to cure the patients with neural disorder and to improve their quality of life. This paper reports the design and synthesis of polypeptides containing neuron stimulate, glutamic acid, for the fabrication of biomimetic 3D scaffold in neural tissue engineering application. The polypeptides are synthesized by efficient chemical reactions.

Single-shot visualization of evolving laser wakefields using an all-optical streak camera.

We visualize ps-time-scale evolution of an electron density bubble--a wake structure created in atmospheric density plasma by an intense ultrashort laser pulse--from the phase "streak" that the bubble imprints onto a probe pulse that crosses its path obliquely. Phase streaks, recovered in one shot using frequency-domain interferometric techniques, reveal the formation, propagation, and coalescence of the bubble within a 3 mm long ionized helium gas target. 3D particle-in-cell simulations validate the observed density-dependent bubble evolution, and correlate it with the generation of a quasimonoenergetic ∼ 100 MeV electron beam.

Single-shot tomographic movies of evolving light-velocity objects.

Tomography--cross-sectional imaging based on measuring radiation transmitted through an object along different directions--enables non-invasive imaging of hidden stationary objects, such as internal bodily organs, from their sequentially measured projections. Here we adapt tomographic methods to visualize--in one laser shot--the instantaneous structure and evolution of a laser-induced object propagating through a transparent Kerr medium. We reconstruct 'movies' of a laser pulse's diffraction, self-focusing and filamentation from phase 'streaks' imprinted onto probe pulses that cross the main pulse's path simultaneously at different angles.

Single-shot visualization of evolving, light-speed structures by multiobject-plane phase-contrast imaging.

We demonstrate a single-shot method of visualizing the evolution of light-speed, laser-generated structures as they propagate over hundreds of Rayleigh lengths (typically ≥10 cm) through a tenuous medium. An ultrashort probe pulse crosses the object's path at a small angle (θ<5°) and a specific time delay. Copies of the phase-modulated probe are then relay-imaged to separate detectors from selected object planes along the propagation path.

Long-term social isolation exacerbates the impairment of spatial working memory in APP/PS1 transgenic mice.

The interaction between gene and environment is known to play a major role in the etiology of several neuropsychiatric disorders, including Alzheimer's disease (AD). The present study evaluated whether environmental manipulations such as social isolation may affect the genetic predisposition to accelerate the onset of AD-related symptoms in an adult APP/PS1 double mutant transgenic mouse model. Transgenic and wild-type male mice were housed either singly or in groups from the age of 3 months, and their behavior was compared at 7 months.

The interaction between acute oligomer Abeta(1-40) and stress severely impaired spatial learning and memory.

In this study, we investigated whether stress can enhance the toxicity of oligomer Abeta(1-40) in the mouse brain. Stress was applied to the animals, consisting of a 2-day inescapable foot shock followed by 3-weekly situation reminders (SRs). We found that stress significantly affected not only the amygdala-dependent (anxiety) but also the hippocampal-dependent (spatial learning and memory) behaviors through the oxidative damage caused in these two regions.