Characterization of the second- and third-harmonic optical susceptibilities of atomically thin tungsten diselenide

Supplementary information accompanies this paper at https://doi.org/10.1038/s41598-018-28374-1We report the first detailed characterization of the sheet third-harmonic optical susceptibility, χ(3)s, of tungsten diselenide (WSe2). With a home-built multiphoton microscope setup developed to study harmonics generation, we map the second and third-harmonic intensities as a function of position in the sample, pump power and polarization angle, for single- and few-layers flakes of WSe2. We register a value of |χ(3)s| ≈ 0.9 × 10-28 m3 V-2 at a fundamental excitation frequency of ℏω = 0.8 eV, which is comparable in magnitude to the third-harmonic susceptibility of other group-VI transition metal dichalcogenides. The simultaneously recorded sheet second-harmonic susceptibility is found to be |χ(2)s| ≈ 0.7 × 10-19 m2 V-1 in very good agreement on the order of magnitude with recent reports for WSe2, which asserts the robustness of our values for |χ(3)s|.Y.W.H. acknowledges scholarship support from NGS. G.E. acknowledges financial support from National Research Foundation of Singapore (NRF Research Fellowship NRF-NRFF2011-02 and medium-sized centre programme) and Ministry of Education of Singapore (AcRF Tier 2 MOE2015-T2-2-123). V. M. P. acknowledges fnancial support from Ministry of Education of Singapore (FRC AcRF Tier 1 R-144-000-386-114). J.C.V.G. acknowledges fnancial support from CA2DM through National Research Foundation of Singapore (NRF-CRP Grant No. R-144-000-295-281)

Transport of organic anions and cations in murine embryonic kidney development and in serially-reaggregated engineered kidneys

Recent advances in renal tissue engineering have shown that dissociated, early renogenic tissue from the developing embryo can self-assemble into morphologically accurate kidney-like organs arranged around a central collecting duct tree. In order for such self-assembled kidneys to be useful therapeutically or as models for drug screening, it is necessary to demonstrate that they are functional. One of the main functional characteristics of mature kidneys is transport of organic anions and cations into and out of the proximal tubule. Here, we show that the transport function of embryonic kidneys allowed to develop in culture follows a developmental time-course that is comparable to embryonic kidney development in vivo. We also demonstrate that serially-reaggregated engineered kidneys can transport organic anions and cations through specific uptake and efflux channels. These results support the physiological relevance of kidneys grown in culture, a commonly used model for kidney development and research, and suggest that serially-reaggregated kidneys self-assembled from separated cells have some functional characteristics of intact kidneys

Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Isoscalar giant dipole resonance in Zr-90, Sn-116, Sm-144 and Pb-208 excited by 240 MeV alpha particle scattering

The giant resonance regions of Zr-90, Sn-116, Sm-144 and (208)pb were investigated using 240 MeV a particle scattering at small angles including 0 degrees. E1 strengths corresponding to 91+/-11%, 89+/-10%, 105+/-12% and 95+/-13% of the isoscalar E1 energy-weighted sum rule were identified between 18 less than or equal to E(x)less than or equal to 31 MeV, 16 less than or equal to E(x)less than or equal to 30 MeV, 15 less than or equal to E(x)less than or equal to 27 MeV and 15 less than or equal to E(x)less than or equal to 25 MeV with centroid energies of 24.8+/-0.4 MeV, 22.5+/-0.3 MeV, 21.6+/-0.3 MeV and 19.3+/-0.3 MeV and rms widths of 3.2+/-0.2 MeV, 3.5+/-0.2 MeV, 3.2+/-0.2 MeV and 2.5+/-0.2 MeV for Zr-90, Sn-116, Sm-144 and Pb-208, respectively. Parameters obtained for the isoscalar giant monopole resonance, isoscalar giant quadrupole resonance and high energy octupole resonance are in agreement with accepted values