Device-quality, reconfigurable metamaterials from shape-directed nanocrystal assembly.

Anchoring nanoscale building blocks, regardless of their shape, into specific arrangements on surfaces presents a significant challenge for the fabrication of next-generation chip-based nanophotonic devices. Current methods to prepare nanocrystal arrays lack the precision, generalizability, and postsynthetic robustness required for the fabrication of device-quality, nanocrystal-based metamaterials [Q. Y.

Anisotropic localized surface plasmons in borophene.

We present a theoretical study on the plasmonic response of borophene, a monolayer 2D material that is predicted to exhibit metallic response and anisotropic plasmonic behavior in visible wavelengths. We investigate plasmonic properties of borophene thin films as well as borophene nanoribbons and nanopatches where polarization-sensitive absorption values in the order of 50% is obtained with monolayer borophene. It is demonstrated that by adding a metal layer, this absorption can be enhanced to 100%.

Continuous-wave quantum dot photonic crystal lasers grown on on-axis Si (001).

Semiconductor III-V photonic crystal (PC) laser is regarded as a promising ultra-compact light source with unique advantages of ultralow energy consumption and small footprint for the next generation of Si-based on-chip optical interconnects. However, the significant material dissimilarities between III-V materials and Si are the fundamental roadblock for conventional monolithic III-V-on-silicon integration technology. Here, we demonstrate ultrasmall III-V PC membrane lasers monolithically grown on CMOS-compatible on-axis Si (001) substrates by using III-V quantum dots.

Effects of Ischemic Post-Conditioning on the Expressions of LC3-II and Beclin-1 in the Hippocampus of Rats After Cerebral Ischemia and Reperfusion.

Objective: To investigate the effects of postconditioning ischemia on the expressions of the hippocampus neuron autophagy-related proteins LC3-II and Beclin-1 in rats following cerebral ischemia reperfusion.

Methods: A total of 128 male Sprague-Dawley rats were randomly divided into 4 groups: control, cerebral ischemia-reperfusion (IR), cerebral ischemia post-conditioning group (IP), and PI3K/Akt inhibitor (LY294002). The rat cerebral ischemia model was established by the improved Pulsinelli four vessel occlusion method.

Extrinsic polarization-controlled optical anisotropy in plasmon-black phosphorus coupled system.

Two-dimensional black phosphorus (BP) has drawn extensive research interest due to its promising anisotropic photonic and electronic properties. Here, we study anisotropic optical absorption and photoresponse of exfoliated BP flakes at visible frequencies. We enhance this intrinsic optical anisotropy in BP flakes by coupling plasmonic rectangular nanopatch arrays that support localized surface plasmon resonances.

DNA-Mediated Size-Selective Nanoparticle Assembly for Multiplexed Surface Encoding.

Multiplexed surface encoding is achieved by positioning two different sizes of gold nanocubes on gold surfaces with precisely defined locations for each particle via template-confined, DNA-mediated nanoparticle assembly. As a proof-of-concept demonstration, cubes with 86 and 63 nm edge lengths are assembled into arrangements that physically and spectrally encrypt two sets of patterns in the same location. These patterns can be decrypted by mapping the absorption intensity of the substrate at λ = 773 and 687 nm, respectively.

Biaxial hyperbolic metamaterials using anisotropic few-layer black phosphorus.

Most of hyperbolic metamaterials (HMMs) investigated to date are based on isotropic materials resulting in uniaxial HMMs in which dielectric permittivities perpendicular to the propagation direction are the same. Using an anisotropic material constituent to form a HMM is a promising research direction providing opportunities to control the dielectric permittivity in all three directions independently. Herein, we propose and theoretically demonstrate novel biaxial HMMs composed of multilayer stacks of few-layer black phosphorus (BP) and Au thin films.

Atrial Natriuretic Peptide: A Potential Early Therapy for the Prevention of Multiple Organ Dysfunction Syndrome Following Severe Trauma.

Trauma remains a tremendous medical burden partly because of increased expenditure for the management of multiple organ dysfunction syndrome (MODS) developed during hospital stay. The intestinal barrier injury continues to be a second insult resulting in MODS which currently lacks efficient strategies for prevention. Recent studies have uncovered multi-organ protective benefits of atrial natriuretic peptide (ANP) in cardiovascular disease.

Quantifying Plasmon-Enhanced Light Absorption in Monolayer WS Films.

Transition metal dichalcogenide semiconductors hold great promise in photonic and optoelectronic applications, such as flexible solar cells and ultrafast photodetectors, because of their direct band gap and few-atom thicknesses. However, it is crucial to understand and improve the absorption characteristics of these monolayer semiconducting materials. In this study, we conducted a systematic numerical and experimental investigation to demonstrate and quantify absorption enhancement in WS monolayer films, in the presence of silver plasmonic nanodisk arrays.

Broadband asymmetric light transmission through tapered metallic gratings at visible frequencies.

Asymmetric transmission phenomenon has attracted tremendous research interest due to its potential applications in integrated photonic systems. Broadband asymmetric transmission (BAT) is a highly desirable but challenging functionality to achieve in the visible regime due to the limitation of material dispersion. In this paper, we propose and numerically demonstrate that a tapered-metal-grating structure (TMGS) can achieve high-contrast BAT spectra covering the entire visible region.

Enhanced infrared transmission through gold nanoslit arrays via surface plasmons in continuous graphene.

Graphene is a monolayer plasmonic material that has been widely studied in the area of plasmonics and nanophotonics. Combining graphene with traditional plasmonic structures provides new opportunities and challenges. One particular application for nanostructured metals is enhanced optical transmission.

Peritoneal Lavage for Severe Acute Pancreatitis: A Meta-analysis and Systematic Review.

Objective: The aim of this study was to assess the efficiency and safety of peritoneal lavage in patients with severe acute pancreatitis.

Methods: A comprehensive search was performed to identify randomized controlled trials that compared peritoneal lavage with conservative treatment for severe acute pancreatitis. The primary outcome was all-cause mortality.

Localized Surface Plasmons in Nanostructured Monolayer Black Phosphorus.

Plasmonic materials provide electric-field localization and light confinement at subwavelength scales due to strong light-matter interaction around resonance frequencies. Graphene has been recently studied as an atomically thin plasmonic material for infrared and terahertz wavelengths. Here, we theoretically investigate localized surface plasmon resonances (LSPR) in a monolayer, nanostructured black phosphorus (BP).

Intensity tunable infrared broadband absorbers based on VO2 phase transition using planar layered thin films.

Plasmonic and metamaterial based nano/micro-structured materials enable spectrally selective resonant absorption, where the resonant bandwidth and absorption intensity can be engineered by controlling the size and geometry of nanostructures. Here, we demonstrate a simple, lithography-free approach for obtaining a resonant and dynamically tunable broadband absorber based on vanadium dioxide (VO2) phase transition. Using planar layered thin film structures, where top layer is chosen to be an ultrathin (20 nm) VO2 film, we demonstrate broadband IR light absorption tuning (from ~90% to ~30% in measured absorption) over the entire mid-wavelength infrared spectrum.

The optical conductivity of bilayer zigzag-edge graphene nanoribbons with external transverse electric fields.

The optical absorption properties of bilayer zigzag-edge graphene nanoribbons (BL-ZGNRs) with external transverse electric fields are investigated by taking into account the Coulomb interaction effect in the Hartree-Fock approximation. We study the phase transitions of BL-ZGNRs induced by external electric fields and also the optical selection rules for the incident light polarized along the longitudinal and transverse directions. We find that the excitations from the edge states are crucial for the optical properties of BL-ZGNRs in the antiferromagnetic phase.