Long-term <i>in vivoi> single-cell lineage tracing of deep structures using three-photon activation

Isil Tekeli, Isabelle Aujard, Xavier Trepat, Ludovic Jullien, Angel Raya

doi:10.1038/lsa.2016.84

Abstract:

Genetic labeling techniques allow for noninvasive lineage tracing of cells <i>in vivoi>. Two-photon inducible activators provide spatial resolution for superficial cells, but labeling cells located deep within tissues is precluded by scattering of the far-red illumination required for two-photon photolysis. Three-photon illumination has been shown to overcome the limitations of two-photon microscopy for <i>in vivoi> imaging of deep structures, but whether it can be used for photoactivation remains to be tested. Here we show, both theoretically and experimentally, that three-photon illumination overcomes scattering problems by combining longer wavelength excitation with high uncaging three-photon cross-section molecules. We prospectively labeled heart muscle cells in zebrafish embryos and found permanent labeling in their progeny in adult animals with negligible tissue damage. This technique allows for a noninvasive genetic manipulation <i>in vivoi> with spatial, temporal

Anisotropic coding metamaterials and their powerful manipulation of differently polarized terahertz waves

Shuo Liu, Tie Jun Cui, Quan Xu, Di Bao, Liangliang Du, Xiang Wan, Wen Xuan Tang, Chunmei Ouyang, Xiao Yang Zhou, Hao Yuan, Hui Feng Ma, Wei Xiang Jiang, Jiaguang Han, Weili Zhang

doi:10.1038/lsa.2016.76

Abstract:

Metamaterials based on effective media can be used to produce a number of unusual physical properties (for example, negative refraction and invisibility cloaking) because they can be tailored with effective medium parameters that do not occur in nature. Recently, the use of coding metamaterials has been suggested for the control of electromagnetic waves through the design of coding sequences using digital elements ‘0’ and ‘1,' which possess opposite phase responses. Here we propose the concept of an anisotropic coding metamaterial in which the coding behaviors in different directions are dependent on the polarization status of the electromagnetic waves. We experimentally demonstrate an ultrathin and flexible polarization-controlled anisotropic coding metasurface that functions in the terahertz regime using specially designed coding elements. By encoding the elements with elaborately designed coding sequences (both 1-bit and 2-bit sequences), the <i>xi>- and <i>yi>-polarized waves

Quantum super-oscillation of a single photon

Guang Hui Yuan, Stefano Vezzoli, Charles Altuzarra, Edward TF Rogers, Christophe Couteau, Cesare Soci and Nikolay I Zheludev, Cesare Soci,Nikolay I Zheludev

doi:10.1038/lsa.2016.127

Abstract:

Super-oscillation is a counterintuitive phenomenon describing localized fast variations of functions and fields that happen at frequencies higher than the highest Fourier component of their spectra. The physical implications of this effect have been studied in information theory and optics of classical fields, and have been used in super-resolution imaging. As a general phenomenon of wave dynamics, super-oscillations have also been predicted to exist in quantum wavefunctions. Here we report the experimental demonstration of super-oscillatory behavior of a single-quantum object, a photon. The super-oscillatory behavior is demonstrated by tight localization of the photon wavefunction after focusing with an appropriately designed slit mask to create an interference pattern with a sub-diffraction hotspot (~0.45<ii>). Such quantum super-oscillation can be used for low-intensity far-field super-resolution imaging techniques even down

Nanoplasmonic mid-infrared biosensor for in vitro protein secondary structure detection

Dordaneh Etezadi, John B Warner IV, Francesco S Ruggeri, Giovanni Dietler, Hilal A Lashuel, Hatice Altug

doi:10.1038/lsa.2017.29

Abstract:

Plasmonic nanoantennas offer new applications in mid-infrared (mid-IR) absorption spectroscopy with ultrasensitive detection of structural signatures of biomolecules, such as proteins, due to their strong resonant near-fields. The amide I fingerprint of a protein contains conformational information that is greatly important for understanding its function in health and disease. Here, we introduce a non-invasive, label-free mid-IR nanoantenna-array sensor for secondary structure identification of nanometer-thin protein layers in aqueous solution by resolving the content of plasmonically enhanced amide I signatures. We successfully detect random coil to cross β-sheet conformational changes associated with α-synuclein protein aggregation, a detrimental process in many neurodegenerative disorders. Notably, our experimental results demonstrate high conformational sensitivity by differentiating subtle secondary-structural variations in a native β-sheet protein monolayer from those of cross

Plasmonic nano-printing: large-area nanoscale energy deposition for efficient surface texturing

Lei Wang, Qi-Dai Chen, Xiao-Wen Cao, Ričardas Buividas, Xuewen Wang, Saulius Juodkazis, Hong-Bo Sun

doi:10.1038/lsa.2017.112

Abstract:

The lossy nature of plasmonic wave due to absorption is shown to become an advantage for scaling-up a large area surface nanotexturing of transparent dielectrics and semiconductors by a self-organized sub-wavelength energy deposition leading to an ablation pattern—ripples—using this plasmonic nano-printing. Irreversible nanoscale modifications are delivered by surface plasmon polariton (SPP) using: (i) fast scan and (ii) cylindrical focusing of femtosecond laser pulses for a high patterning throughput. The mechanism of ripple formation on ZnS dielectric is experimentally proven to occur via surface wave at the substrate–plasma interface. The line focusing increase the ordering quality of ripples and facilitates fabrication over wafer-sized areas within a practical time span. Nanoprinting using SPP is expected to open new applications in photo-catalysis, tribology, and solar light harvesting via localized energy deposition rather scattering used in photonic and sensing applications

Extremely high-efficiency and ultrasimplified hybrid white organic light-emitting diodes exploiting double multifunctional blue emitting layers

Bai-Quan Liu, Lei Wang, Dong-Yu Gao, Jian-Hua Zou, Hong-Long Ning, Jun-Biao Peng and Yong Cao, Jun-Biao Peng,Yong Cao

doi:10.1038/lsa.2016.137

Abstract:

In addition, the device exhibits the lowest voltages among hybrid WOLEDs (i.e., 2.4, 2.7 and 3.1

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