High-Resolution Metalens Imaging Polarimetry.

Imaging polarimeters find many critical applications in applications ranging from remote sensing to biological detection. Metasurfaces have been proposed as a compact approach for imaging polarimeters, but prior strategies suffer from low imaging resolution. Here, we propose an interleaved metalens configuration for polarization imaging where three-row metasurface units within a group individually interact with three pairs of orthogonal polarization channels. The optical paths between the object and adjacent three-row metasurfaces are nearly equal, allowing the construction of a metalens polarimeter with an unlimited numerical aperture (NA), which is beneficial for high-resolution polarization imaging. The metalens polarimeter fabricated by crystalline silicon nanostructures has a NA of 0.51 at 632.8 nm and achieves an imaging resolution of up to a 1.2-fold wavelength. Polarimetric microscopy experiments demonstrate that metalens polarimeters can realize high-resolution polarization imaging for various microscopic samples. This study offers a promising solution for high-resolution metasurface polarization imaging, with the potential for widespread applications.

Enhancing chiroptical responses in the nanoparticle system by manipulating the far-field and near-field couplings.

Employing nanostructure to generate large chiroptical response has been cultivated as an emerging field, for its great potentials in integrated optics, biochemistry detections, etc. However, the lack of intuitive approaches for analytically describing the chiroptical nanoparticles has discouraged researchers from effectively designing advanced chiroptical structures. In this work, we take the twisted nanorod dimer system as a basic example to provide an analytical approach from the perspective of mode coupling, including far-field coupling and near-field coupling of nanoparticles. Using this approach, we can calculate the expression of circular dichroism (CD) in the twisted nanorod dimer system, which can establish the analytical relationship between the chiroptical response and the basic parameters of this system. Our results show that the CD response can be engineered by modulating the structure parameters, and a high CD response of ∼ 0.78 under the guidance of this approach has been achieved.

Low-frequency broadband multilayer microwave metamaterial absorber based on resistive frequency selective surfaces.

Herein, a low-frequency broadband multilayer metamaterial absorber (MMA) based on resistive frequency selective surfaces (RFSSs) is proposed, which consists of a three-layer RFSS, three-layer polymethacrylimide (PMI) foam substrates, and a copper film. The proposed absorber has the advantages of ultra-broadband absorption with absorptivity more than 90% ranging from 1.91 to 20.78 GHz, which covers the entire S, C, X, and Ku bands with the thickness of 0.102λ L (where λ L corresponds to the wavelength of the lowest operating frequency). The absorption performance can keep good stability in a wide angular range for both TE and TM modes. Moreover, a prototype of the proposed MMA is fabricated and experimentally measured to demonstrate its excellent performance. The experimental results show excellent consistency with numerical simulations.

Pseudomembranous necrotizing laryngotracheobronchitis due to Mycoplasma pneumoniae: a case report and literature review.

BACKGROUND: Pseudomembranous necrotizing laryngotracheobronchitis refers to an acute diffuse necrotizing inflammation in the mucosa of the larynx, trachea, and bronchus. It often occurs in infants and children having viral infections secondary to bacterial infections. Mycoplasma pneumoniae (M. pneumoniae) is a common pathogen that causes pneumonia in children. In recent years, serious complications due to M. pneumoniae infection, including necrotizing pneumonia, pulmonary embolism, and pleural effusion, have been increasingly reported. CASE PRESENTATION: An 11-year-old girl was admitted to our unit with cough, fever, and hoarseness persistent for a week. The results of the M. pneumoniae serological test, PCR examination with bronchial aspirate and bronchoalveolar lavage fluid (BALF), next-generation sequencing (mNGS) for BALF, all suggested the presence of M. pneumoniae infection. High-resolution CT scanning of the chest showed inflammation of the middle and lower lobes of the right lung. By bronchoscopy, the necrosis of the vocal cords, trachea, and bronchial mucosa was observed; each bronchial lumen contained a large amount of white viscous sputum. Pathological findings for bronchial mucosa suggested inflammatory necrosis. After administration of azithromycin and glucocorticoids, the symptoms of the patients were ameliorated. After 2 weeks post-discharge, the X-ray scan of her chest indicated the pneumonia resolution in the right lung. CONCLUSIONS: In patients with pneumonia due to M. pneumoniae infection, which causes obvious hoarseness, bronchoscopy is necessary even if the lung lesions are not massively consolidated. When necrotizing lesions of the larynx, trachea, and bronchi are detected by bronchoscopy, the necrotic tissues in the corresponding parts should be conducted tissue biopsy for pathological examination. Apart from macrolide antibiotics, the administration of small doses of glucocorticoids is necessary.

Steering Room-Temperature Plexcitonic Strong Coupling: A Diexcitonic Perspective.

Plexcitonic strong coupling between a plasmon-polariton and a quantum emitter empowers ultrafast quantum manipulations in the nanoscale under ambient conditions. The main body of previous studies deals with homogeneous quantum emitters. To enable multiqubit states for future quantum computing and network, the strong coupling involving two excitons of the same material but different resonant energies has been investigated and observed primarily at very low temperature. Here, we report a room-temperature diexcitonic strong coupling (DiSC) nanosystem in which the excitons of a transition metal dichalcogenide monolayer and dye molecules are both strongly coupled to a single Au nanocube. Coherent information exchange in this DiSC nanosystem could be observed even when exciton energy detuning is about five times larger than the respective line widths. The strong coupling behaviors in such a DiSC nanosystem can be manipulated by tuning the plasmon resonant energies and the coupling strengths, opening up a paradigm of controlling plasmon-assisted coherent energy transfer.

Metaoptronic Multiplexed Interface for Probing Bioentity Behaviors.

Biointerface sensors have brought about remarkable advances in modern biomedicine. To accurately monitor bioentity's behaviors, biointerface sensors need to capture three main types of information, which are the electric, spectroscopic, and morphologic signals. Simultaneously obtaining these three types of information is of critical importance in the development of future biosensor, which is still not possible in the existing biosensors. Herein, by synergizing metamaterials, optical, and electronic sensing designs, we proposed the metaoptronic multiplexed interface (MMI) and built a MMI biosensor which can collectively record electric, spectroscopic, and morphologic information on bioentities. The MMI biosensor enables the real-time triple-monitoring of cellular dynamics and opens up the possibility for powerlessly monitoring ocular dryness. Our findings not only demonstrate an advanced multiplexed biointerface sensor with integrated capacities but also help to identify a uniquely significant arena for the nanomaterials, meta-optics, and nanotechnologies to play their roles in a complementary manner.

Ferroelectric-Gated InSe Photodetectors with High On/Off Ratios and Photoresponsivity.

Indium selenide (InSe) has a high electron mobility and tunable direct band gap, enabling its potential applications to electronic and optoelectronic devices. Here, we report the fabrication of InSe photodetectors with high on/off ratios and ultrahigh photoresponsivity, using ferroelectric poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) copolymer films as the top-gate dielectric. Benefiting from the successful suppression of the dark current down to ∼10-14A in the InSe channel by tuning the three different polarization states in ferroelectric P(VDF-TrFE) and improved interface properties using h-BN as a substrate, the ferroelectric-gated InSe photodetectors show a high on/off ratio of over 108, a high photoresponsivity up to 14 250 AW-1, a high detectivity up to 1.63 × 1013 Jones, and a fast response time of 600 µs even at zero-gate voltage. The present results highlight the role of ferroelectric P(VDF-TrFE) in tuning the carrier transport of InSe and may provide an avenue for the development of InSe-based photodetectors.

Reconfigurable Photon Sources Based on Quantum Plexcitonic Systems.

A single photon in a strongly nonlinear cavity is able to block the transmission of a second photon, thereby converting incident coherent light into antibunched light, which is known as the photon blockade effect. Photon antipairing, where only the entry of two photons is blocked and the emission of bunches of three or more photons is allowed, is based on an unconventional photon blockade mechanism due to destructive interference of two distinct excitation pathways. We propose quantum plexcitonic systems with moderate nonlinearity to generate both antibunched and antipaired photons. The proposed plexcitonic systems benefit from subwavelength field localizations that make quantum emitters spatially distinguishable, thus enabling a reconfigurable photon source between antibunched and antipaired states via tailoring the energy bands. For a realistic nanoprism plexcitonic system, chemical and optical schemes of reconfiguration are demonstrated. These results pave the way to realize reconfigurable nonclassical photon sources in a simple quantum plexcitonic platform.

Insulating SiO2 under Centimeter-Scale, Single-Crystal Graphene Enables Electronic-Device Fabrication.

Graphene on SiO2 enables fabrication of Si-technology-compatible devices, but a transfer of these devices from other substrates and direct growth have severe limitations due to a relatively small grain size or device-contamination. Here, we show an efficient, transfer-free way to integrate centimeter-scale, single-crystal graphene, of a quality suitable for electronic devices, on an insulating SiO2 film. Starting with single-crystal graphene grown epitaxially on Ru(0001), a SiO2 film is grown under the graphene by stepwise intercalation of silicon and oxygen. Thin (∼1 nm) crystalline or thicker (∼2 nm) amorphous SiO2 has been produced. The insulating nature of the thick amorphous SiO2 is verified by transport measurements. The device-quality of the corresponding graphene was confirmed by the observation of Shubnikov-de Haas oscillations, an integer quantum Hall effect, and a weak antilocalization effect within in situ fabricated Hall bar devices. This work provides a reliable platform for applications of large-scale, high-quality graphene in electronics.

Genomic Identification and Functional Analysis of JHAMTs in the Pond Wolf Spider, Pardosa pseudoannulata.

Juvenile hormone (JH) plays a critical role in many physiological activities of Arthropoda. Juvenile hormone acid methyltransferase (JHAMT) is involved in the last steps of JH biosynthesis as an important rate-limiting enzyme. In recent studies, an increasing number of JHAMTs were identified in arthropods, but no JHAMT was reported in spiders. Herein, eight JHAMTs were identified in the pond wolf spider, Pardosa pseudoannulata, all containing the well conserved S-adenosyl-L-methionine binding motif. JHAMT-1 and the other seven JHAMTs were located at chromosome 13 and chromosome 1, respectively. Multiple alignment and phylogenetic analysis showed that JHAMT-1 was grouped together with insect JHAMTs independently and shared high similarities with insect JHAMTs compared to the other seven JHAMTs. In addition, JHAMT-1, JHAMT-2, and JHAMT-3 were highly expressed in the abdomen of spiderlings and could respond to the stimulation of exogenous farnesoic acid. Meanwhile, knockdown of these three JHAMTs caused the overweight and accelerated molting of spiderlings. These results demonstrated the cooperation of multi-JHAMTs in spider development and provided a new evolutionary perspective of the expansion of JHAMT in Arachnida.

Modified reverse-puncture anastomotic technique vs. traditional technique for total minimally invasive Ivor-Lewis esophagectomy.

BACKGROUND: Total endoscopic Ivor-Lewis esophagectomy is a challenging, complex, and costly operation. These disadvantages restrict its wide application. The aim of this study was to compare the modified reverse-puncture anastomotic technique and traditional technique for total minimally invasive Ivor-Lewis esophagectomy. METHODS: In this cohort retrospective study, all patients with medial and lower squamous cell carcinoma of esophagus from February 2014 and June 2018 were divided into two groups according to the surgical method, which were modified reverse-puncture anastomotic technique group and traditional technique group. The operation time, intraoperative bleeding volume, complications, and cost of the two groups were compared. RESULTS: Forty-eight patients in the modified reverse-puncture anastomotic technique group while 54 patients in the traditional technique group were included. The operation time was 293.4 ± 57.2 min in the modified reverse-puncture anastomotic technique group, which was significantly shorter than that in the traditional technique group (353.4 ± 64.1 min) (P < 0.05). The intraoperative bleeding volume of modified reverse-puncture anastomotic technique group was 157.3 ± 107.4 ml, while it was 191.9 ± 123.6 ml in traditional technique group (P = 0.14). There were similar complications between the two groups. The cost of modified reverse-puncture anastomotic and traditional technique in our hospital were and 72 ± 13 and 83 ± 41 thousand Yuan, respectively (P = 0.08). CONCLUSION: The good short-term outcomes that were achieved suggested that the use of modified reverse-puncture anastomotic technique is safe and feasible for total endoscopic Ivor-Lewis esophagectomy.

Quasi-2D Transport and Weak Antilocalization Effect in Few-layered VSe2.

With strong spin-orbit coupling (SOC), ultrathin two-dimensional (2D) transitional metal chalcogenides (TMDs) are predicted to exhibit weak antilocalization (WAL) effect at low temperatures. The observation of WAL effect in VSe2 is challenging due to the relative weak SOC and three-dimensional (3D) transport nature in thick VSe2. Here, we report on the observation of quasi-2D transport and WAL effect in sublimed-salt-assisted low-temperature chemical vapor deposition (CVD) grown few-layered high-quality VSe2 nanosheets. The WAL magnitudes in magnetoconductance can be perfectly fitted by the 2D Hikami-Larkin-Nagaoka (HLN) equation in the presence of strong SOC, by which the spin-orbit scattering length lSO and phase coherence length lϕ have been extracted. The phase coherence length lϕ shows a power law dependence with temperature, lϕ∼ T-1/2, revealing an electron-electron interaction-dominated dephasing mechanism. Such sublimed-salt-assisted growth of high-quality few-layered VSe2 and the observation of WAL pave the way for future spintronic and valleytronic applications.

Observation of the Kondo Effect in Multilayer Single-Crystalline VTe2 Nanoplates.

We report the chemical vapor deposition (CVD) growth, characterization, and low-temperature magnetotransport of 1T phase multilayer single-crystalline VTe2 nanoplates. The transport studies reveal that no sign of intrinsic long-range ferromagnetism but localized magnetic moments exist in the individual multilayer metallic VTe2 nanoplates. The localized moments give rise to the Kondo effect, evidenced by logarithmical increment of resistivity with decreasing temperature and negative magnetoresistance (NMR) regardless of the direction of magnetic field at temperatures below the resistivity minimum. The low-temperature resistivity upturn is well described by the Hamann equation, and the NMR at different temperatures, a manifestation of the magnetization of the localized spins, is well fitted to a Brillouin function for S = 1/2. Density functional theory calculations reveal that the localized magnetic moments mainly come from the interstitial vanadium ions in the VTe2 nanoplates. Our results will shed light on the study of magnetic properties, strong correlation, and many-body physics in two-dimensional metallic transition metal dichalcogenides.

Morphine activates blast-phase chronic myeloid leukemia cells and alleviates the effects of tyrosine kinase inhibitors.

Morphine is an opioid analgesic drug routinely used in the postoperative period for pain management in cancer patients. In this work, we analyzed the effects of morphine on leukemia cells at all stages of development and addressed its underlying mechanism. We showed that clinically relevant concentrations of morphine promoted growth without affecting survival in blast phase-chronic myeloid leukemia (BP-CML) K562 and LAMA84 cells. In addition, morphine alleviated the anti-proliferative and pro-apoptotic effects of BCR-ABL tyrosine kinase inhibitor (TKI) in BP-CML cells. We further found that morphine increased colony formation and replating capacity of CD34 stem/progenitor derived from BP-CML patients. In addition, morphine alleviated the inhibitory effects of BCR-ABL TKIs in cell survival, colony formation and replating capacity in BP-CML CD34 + stem/progenitor cells. Mechanistic investigations demonstrated that morphine specifically activated Wnt signaling via increasing ß-catenin activity and Wnt target genes transcription in K562 and CD34 + stem/progenitor cells. The effects of morphine in BP-CML were abolished by Wnt inhibitor LGK-974 or XAV939, which further confirmed that morphine protected BP-CML cells from BCR-ABL TKIs-induced toxicity via activating Wnt/ß-catenin signaling. Our work demonstrated the novel role of morphine on leukemia cells. The activation of Wnt/ß-catenin by morphine may provide a new guide in the clinical use of morphine, particularly in patients with Wnt-driven cancers.

Inhibition of the sterol regulatory element-binding protein pathway suppresses hepatocellular carcinoma by repressing inflammation in mice.

Obesity is a critical risk factor for hepatocellular carcinoma (HCC). However, it remains unknown whether inhibition of de novo lipid biosynthesis can suppress HCC. In this study, we blocked the sterol regulatory element-binding protein (SREBP) pathway, one of the key determinants of lipid homeostasis, by ablating 78-kDa cell-surface glycoprotein or SREBP cleavage-activating protein in hepatocytes, as well as by administering a chemical compound called betulin. We found that either genetically or pharmacologically inhibiting the SREBP pathway dramatically reduced diethylnitrosamine-induced HCC progression by down-regulating tumor-promoting cytokines, including interleukin (IL)-6, tumor necrosis factor alpha, and IL-1ß. CONCLUSION: Inhibition of de novo lipid biosynthesis by suppressing the SREBP pathway prevents HCC. This study identifies a previously underappreciated role of the SREBP pathway in HCC and suggests a novel metabolic strategy to control liver cancer. (Hepatology 2017;65:1936-1947).

Flexible Nanowire Cluster as a Wearable Colorimetric Humidity Sensor.

Wearable plasmonic devices combine the advantages of high flexibility, ultrathinness, light weight, and excellent integration with the optical benefits mediated by plasmon-enhanced electric fields. However, two obstacles severely hinder further developments and applications of a wearable plasmonic device. One is the lack of efficient approach to obtaining devices with robust antimotion-interference property, i.e., the devices can work independently on the morphology changes of their working structures caused by arbitrary wearing conditions. The other issue is to seek a facile and high-throughput fabrication method to satisfy the financial requirement of industrialization. In order to overcome these two challenges, a functional flexible film of nanowire cluster is developed, which can be easily fabricated by taking the advantages of both conventional electrochemical and sputtering methods. Such flexible plasmonic films can be made into wearable devices that work independently on shape changes induced by various wearing conditions (such as bending, twisting and stretching). Furthermore, due to plasmonic advantages of color controlling and high sensitivity to environment changes, the flexible film of nanowire cluster can be used to fabricate wearable items (such as bracelet, clothes, bag, or even commercial markers), with the ability of wireless visualization for humidity sensing.

Strong Light-Matter Interactions in Single Open Plasmonic Nanocavities at the Quantum Optics Limit.

Reaching the quantum optics limit of strong light-matter interactions between a single exciton and a plasmon mode is highly desirable, because it opens up possibilities to explore room-temperature quantum devices operating at the single-photon level. However, two challenges severely hinder the realization of this limit: the integration of single-exciton emitters with plasmonic nanostructures and making the coupling strength at the single-exciton level overcome the large damping of the plasmon mode. Here, we demonstrate that these two hindrances can be overcome by attaching individual J aggregates to single cuboid Au@Ag nanorods. In such hybrid nanosystems, both the ultrasmall mode volume of ∼71 nm^{3} and the ultrashort interaction distance of less than 0.9 nm make the coupling coefficient between a single J-aggregate exciton and the cuboid nanorod as high as ∼41.6 meV, enabling strong light-matter interactions to be achieved at the quantum optics limit in single open plasmonic nanocavities.

Precise characterization of self-catalyzed III-V nanowire heterostructures via optical second harmonic generation.

We demonstrate the utility of optical second harmonic generation (SHG) polarimetry to perform structural characterization of self-assembled zinc-blende/wurtzite III-V nanowire heterostructures. By analyzing four anisotropic SHG polarimetric patterns, we distinguish between wurtzite (WZ), zinc-blende (ZB) and ZB/WZ mixing III-V semiconducting crystal structures in nanowire systems. By neglecting the surface contributions and treating the bulk crystal within the quasi-static approximation, we can well explain the optical SHG polarimetry from the NWs with diameter from 200-600 nm. We show that the optical in-coupling and out-coupling coefficients arising from depolarization field can determine the polarization of the SHG. We also demonstrate micro-photoluminescence of GaAs quantum dots in related ZB and ZB/WZ mixing sections of core-shell NW structure, in agreement with the SHG polarimetry results. The ability to perform in situ SHG-based crystallographic study of semiconducting single and multi-crystalline nanowire heterostructures will be useful in displaying structure-property relationships of nanodevices.

Near-UV-enhanced broad-band large third-order optical nonlinearity in aluminum nanorod array film with sub-10 nm gaps.

Plasmonic nanostructures with sub-10 nm gaps possess intense electric field enhancements, leading to their high reputation for exploring various functional applications at nanoscale. Till now, although large amounts of efforts have been devoted into investigation of such structures, few works were emphased on the nonlinear optical properties in near-ultraviolet (UV) region. Here, by combining sputtering technique and an optimized anodic aluminum oxide (AAO) template growing method, we obtain aluminum (Al) nanorod array film (NRAF) with average rod diameter and gap size of 50 and 7 nm, respectively. The Al-NRAF exhibits large third-order optical nonlinear susceptibility (χ(3)) and high figure of merit (χ(3)/α) over a broad wavelength range from 360 to 900 nm, and reaches their maximums at the shortest measured wavelength. In addition, comparisons with Au-NRAF and Ag-NRAF samples further confirm that Al-NRAF has better nonlinear optical properties in the blue and near-UV wavelength regions. These results indicate that Al nanostructures are promising candidates for nonlinear plasmonic applications at blue and near-UV wavelengths.

Charging Mechanism for Polymer Particles in Nonpolar Surfactant Solutions: Influence of Polymer Type and Surface Functionality.

Surface charging phenomena in nonpolar dispersions are exploited in a wide range of industrial applications, but their mechanistic understanding lags far behind. We investigate the surface charging of a variety of polymer particles with different surface functionality in alkane solutions of a custom-synthesized and purified polyisobutylene succinimide (PIBS) polyamine surfactant and a related commercial surfactant mixture commonly used to control particle charge. We find that the observed electrophoretic particle mobility cannot be explained exclusively by donor-acceptor interactions between surface functional groups and surfactant polar moieties. Our results instead suggest an interplay of multiple charging pathways, which likely include the competitive adsorption of ions generated among inverse micelles in the solution bulk. We discuss possible factors affecting the competitive adsorption of micellar ions, such as the chemical nature of the particle bulk material and the size asymmetry between inverse micelles of opposite charge.