Topological Structures of Energy Flow: Poynting Vector Skyrmions.

Topological properties of energy flow of light are fundamentally interesting and may introduce novel physical phenomena associated with directional light scattering and optical trapping. In this Letter, skyrmionlike structures formed by Poynting vectors are unveiled in the focal region of two pairs of counterpropagating cylindrical vector vortex beams in free space. The appearance of local phase singularities, and the distinct traveling and standing wave modes of different field components passing through the focal spot lead to a Néel-Bloch-Néel transition of Poynting vector skyrmion textures along the light propagating direction. By shaping the wave front of the incident beams with patterned amplitudes, the topological invariant of the Poynting vector skyrmions can be further tuned in a prospective area. This work expands the family of optical skyrmions and holds great potential in energy flow associated applications.

Sub-100†nm pixel pitch via STED photolithography with a nanoprinting-at-expansion/employments-at-recovery strategy.

Featured with its extraordinary super-resolution capability, the advent of stimulated emission depletion (STED) lithography has allowed for vastly reduced minimum feature size of a single pixel down to the deep sub-diffraction scale so as to produce unprecedented nanofeatures. However, the anticipated sub-diffraction pixel pitch down below 100 nm remains out of reach due to redundant polymerization of adjacent exposures at a short distance, so called memory effect. In this work, a nanoprinting-at-expansion/employments-at-recovery strategy is applied in the dual-beam STED lithography technique to surmount the memory effect and break adjacent-exposure limit imposed on minimizing the pixel pitch. The implementation of a femtosecond laser at a wavelength of 532 nm, the same as the inhibition laser beam, working as the initiation laser beam, can drastically reduce the saturated inhibition laser intensity by 74% for abating redundant polymerization subjected to multiple exposures in realizing nanoscale pixel pitch. The adjacent-exposure zone can be separated by isotropically expanding an elastic PDMS substrate for further diminishing redundant polymerization. Applying stretching ratio of 30%, a minimum super-resolved nanodots pixel pitch of 96 nm was achieved with single-dot size of 34 nm on both planar and hierarchical substrate, which offers a record-close distance for printing adjacent pixels. With its nanometer discernibility, this method holds great promise for future versatile utilization in advanced nanoimprinting, high density data storage, etc.

Photo-Assisted Robust Anti-Interference Self-Powered Biosensing of MicroRNA Based on Pt-S Bonds and the Inorganic-Organic Hybridization Strategy.

Photo-assisted biofuel cell-based self-powered biosensors (PBFC-SPBs) possess the advantages of no need for external power supply, ease of sensing design, and simple instruments. In this work, a robust anti-interference PBFC-SPB for microRNA detection was constructed based on the Pt-S bond and the inorganic-organic hybridization strategy. The organic semiconductor [6,6]-phenyl-C61-butyric acid methylester@anthraquinone (PCBM@anthraquinone) served as an efficient light-harvesting material, and gold nanoparticle@Pt (AuNP@Pt) nanomaterials were immobilized on the surface via electrostatic adsorption for the binding of DNA. Notably, compared to Au-S bonds for DNA immobilization, the Pt-S bond exhibited better anti-interference ability. Ingeniously, cadmium sulfide quantum dots (CdS QDs) were close to the PCBM@anthraquinone substrate electrode to form sensitization structures, which was beneficial to enhance the photocurrent signal. Combining with the laccase-mimicking activity Cu2+/carbon nanotubes (Cu2+/CNTs) cathode, the PBFC-SPB for microRNA detection was achieved. Once the target existed, the identical sequence complementary microRNA would make DNA2/CdS dissociate and break away from the electrode, leading to a low signal. The linear detection range was 10 fM-100 pM, with the limit of determination of 2.4 fM (3S/N). The as-proposed strategy not only paves a new way for the design of photoelectrochemical biosensing but also opens a door for the construction of robust anti-interference bioassay for microRNA detection.

Circ_0037866 Contributes to the Tumorigenesis of Renal Cell Carcinoma by Sequestering miR-384 to Elevate Chromobox 5 Expression.

BACKGROUND: Circular RNAs (circRNAs) were demonstrated to have roles in the carcinogenesis of renal cell carcinoma (RCC). Hence, this work aimed to determine the functions and molecular mechanism of circ_0037866 in regulating the progression of RCC. METHODS: Quantitative real-time polymerase chain reaction and Western blotting were used to detect the levels of genes and proteins. In vitro assays, including colony formation, 5-ethynyl-2'-deoxyuridine, flow cytometry, transwell assays, and in vivo tumor formation, were conducted to investigate the effects of circ_0037866 on RCC tumorigenesis. Dual-luciferase reporter assay, RNA pull-down, and RNA immunoprecipitation assay were used to confirm the interaction between miR-384 and circ_0037866 or Chromobox 5 (CBX5). RESULTS: Circ_0037866 is a stable circRNA and was found to be increased in RCC tissues and cells. Functionally, circ_0037866 silencing suppressed RCC cell survival, invasion, and migration in vitro, and impeded RCC cell tumorigenesis in the subcutaneous xenograft model. Mechanistically, circ_0037866 could function as a sponge for miR-384 to elevate the expression of its target CBX5. Furthermore, a series of rescue experiments showed that miR-384 inhibition reversed the anticancer effects of circ_0037866 knockdown on RCC cells; besides that, miR-384 restoration suppressed RCC cell growth and mobility, which were attenuated by CBX5 overexpression. CONCLUSION: Circ_0037866 knockdown restrains the tumorigenesis of RCC by miR-384/CBX5, revealing a promising molecular target for RCC therapy.

3D high precision laser printing of a flat nanofocalizer for subwavelength light spot array.

Here, we demonstrate a flat nanofocalizer for converging light field into a uniform subwavelength light spot array based on the fractional Talbot effect by developing a direct laser writing technique with 3D fabrication precision. The fractional Talbot effect endows the device with the merits of high compression ratio and modular design capability for transforming a plane wave into arrayed light focal spots. By combining a synergistic laser printing technique, we introduce a buffer layer for improving the fabrication precision of structural height in favor of accurately manipulating the phase delay. For a given light wavelength at 750 nm, by precisely producing a nanofocalizer consisting of periodic unit elements with the dimensions of 300(width)×600(length)×585(height)nm, we have achieved 5×6 light spot array with modular design, while the full width at half-maximum of a single focused light spot can be reduced to ∼0.82λ. Our research may pave the way for realizing subwavelength optical devices capable of being readily integrated to existing optical systems.

Laser nanoprinting of floating three-dimensional plasmonic color in pH-responsive hydrogel.

Recent demonstrations of metasurfaces present their great potential to implement flat and multifunctional optical elements, which are accomplished with the designs of planar optics and micro-/nano- fabrications. Integrating metasurfaces in three dimensions has manifested drastically increasing advantages in manipulating light fields by extending design freedom. However, fabricating three-dimensional metasurfaces remain a tough challenge due to the lack of stereo printing protocols. Herein, we demonstrate laser nanoprinting of floated silver nanoparticle array in transparent hydrogel films for 3D metasurface to achieve color patterning. It is found that spatially resolved nanoparticles can be produced through laser induced photoreduction of silver ions and robustly anchored to the gel backbones by a focused femtosecond laser beam within a pH-responsive smart hydrogel matrix. With the aid of expansion properties of the pH-responsive hydrogel, repetitive coloration of the patterned plasmonic nanoparticle array over a wide spectrum range is achieved via reversible regulation of nanoparticle spacing from 550 to 350 nm and vice versa. This approach allows broadband 3D color-regulation in nanoscale for applications in active spectral filtering, information encryption, security tagging and biological colorimetric sensing, etc.

Tunable graphene metasurfaces by discontinuous Pancharatnam-Berry phase shift.

Metal-dielectric-graphene three-layer structures are proposed to improve the interaction of graphene micro- and nanostructures with incident waves, as the upper graphene cut-wire layer introduces a discontinuous Pancharatnam-Berry phase profile. A semi-analytical method based on the Jones calculus is conducted to investigate the conversion efficiency of cross-polarized light on this graphene metasurface for circularly polarized wave incidence, which predicts that the physical constraint (25%) of cross-coupling conversion efficiency for individual graphene layers can be overcome. Numerical simulations confirm the conclusion and demonstrate an efficiency as high as 60%. Based on this mechanism, high-efficiency anomalous reflection surfaces and flat focal mirrors are designed with the tunability of reflection angles and one order of magnitude improved focusing intensity. This method paves the way to engineering high-efficiency graphene metasurfaces for tunable electromagnetic wave manipulation.

Photon harvesting, coloring and polarizing in photovoltaic cell integrated color filters: efficient energy routing strategies for power-saving displays.

We describe the integral electro-optical strategies that combine the functionalities of photovoltaic (PV) electricity generation and color filtering as well as polarizing to realize more efficient energy routing in display technology. Unlike the conventional pigment-based filters and polarizers, which absorb substantial amounts of unwanted spectral components and dissipate them in the form of heat, we propose converting the energy of those photons into electricity by constructing PV cell-integrated color filters based on a selectively transmitting aluminum (Al) rear electrode perforated with nanoholes (NHs). Combining with a dielectric-metal-dielectric (DMD) front electrode, the devices were optimized to enable efficient cavity-enhanced photon recycling in the PV functional layers. We perform a comprehensive theoretical and numerical analysis to explore the extraordinary optical transmission (EOT) through the Al NHs and identify basic design rules for achieving structural coloring or polarizing in our PV color filters. We show that the addition of thin photoactive polymer layers on the symmetrically configured Al NH electrode narrows the bandwidth of the EOT-assisted high-pass light filtering due to the strongly damped anti-symmetric coupling of the surface modes excited on the front and rear surface of the Al NHs, which facilitates the whole visible coloring with relatively high purity for the devices. By engineering the cut-off characteristics of the plasmonic waveguide mode supported by the circular or ellipsoidal Al NHs, beyond the photon recycling capacity, PV color filters and PV polarizing color filters that allow polarization-insensitive and strong polarization-anisotropic color filtering were demonstrated. The findings presented here may shed some light on expanding the utilization of PV electricity generation across new-generation energy-saving electrical display devices.

Risk assessment and prevention of urolithiasis in urban areas of Baoding, China.

Urolithiasis, or the formation of calculi in the urinary system, represents a prevalent urological condition frequently encountered among individuals aged 30 to 55 years. An in-depth analysis of the composition of these calculi holds significant promise in shedding light on the underlying etiological and pathogenic factors contributing to this ailment. The primary objective of this study was to delineate the principal components comprising urinary system calculi within a cohort of patients who sought medical intervention at a tertiary grade A hospital located in Baoding City. Furthermore, our investigation entailed a comprehensive examination of the physical and morphological characteristics exhibited by these calculi. In this study, a total of 2307 individuals afflicted with urinary system calculi were recruited as participants, and a corresponding number of 2307 calculous specimens were subjected to thorough examination. The specimens were examined using infrared spectroscopy. We collected and examined patient data including gender, age, location of the calculi, employment status, residential area, and other factors. The middle-aged demographic exhibited a conspicuous predilection for urinary system calculi, wherein a notable gender disparity was observed, with a male-to-female ratio of 1.63 to 1. Among the enrolled patients, kidney calculi were prevalent in 1270 cases, ureteral calculi were documented in 983 cases, and bladder calculi were encountered in 46 instances. Notably, the principal components comprising these calculi were identified as calcium oxalate and apatite, while uric acid and ammonium magnesium phosphate were comparatively less frequently encountered. Furthermore, the analysis of calculus composition across patients residing in distinct geographical regions did not reveal any statistically significant variations. The identification of components within upper urinary tract calculi plays a pivotal role in elucidating the root causes of calculus formation. This valuable information empowers healthcare professionals, particularly nursing staff, to provide personalized dietary and health guidance to patients, thereby enhancing the quality of care and promoting more effective management of this condition.

Subcell misalignment in vertically cascaded metamaterial absorbers.

Metamaterial has demonstrated exotic electromagnetic (EM) properties and various applications, for example perfect absorbers. Cascaded perfect absorbers further extend the spectral engineering ability. Perfect alignment of subcells was usually presumed in previous studies. We numerically investigated the effect of lateral misalignments existing in the multiple lithography steps for vertically cascaded metamaterial absorbers and found that the position deviations of the subcells play an important role of the spectral response. As an example, near-unity absorbance reduces to only 30% for a λ/10 subcell misalignment. The detailed investigation of EM field and induced current distributions reveals that the relative position variations of strongly coupled subcells contribute to this phenomenon. The results give us an evaluation that how much registration accuracy is required in multi-step lithography for cascaded metamaterials and on the other side a hint of the potential application of this high position sensitivity.

Plasmonic waveguides with low polarization dependence.

Plasmonic waveguides essentially support only transverse magnetic modes. A novel plasmonic waveguide consisting of hybrid plasmonic waveguides in both vertical and horizontal directions is proposed to reduce the polarization dependence. In a combined waveguide, surface plasmon polariton (SPP) modes polarized in both vertical and horizontal directions exist in the correspondingly oriented hybrid plasmonic waveguide. In an optimized structure, anticrossing mode coupling is observed between these two SPP modes with a low birefringence by finite-difference time-domain simulation. The energy flux clearly shows the polarization-selective coupling between the polarized guided modes in the feeding silicon waveguide and those in the combined waveguide. Coupling efficiency above 65% is obtained for both polarizations. The proposed plasmonic combined waveguide has a potential application in guiding and processing of light from a fiber with a random polarization state.

3D Laser Nanoprinting of Optically Functionalized Structures with Effective-Refractive-Index Tailorable TiO2 Nanoparticle-Doped Photoresin.

The advanced direct laser printing of functional devices with tunable effective index is a key research topic in numerous emerging fields, especially in micro-/nano-optics, nanophotonics, and electronics. Photosensitized nanocomposites, consisting of high-index materials (e.g., titanium dioxide, TiO2) embedded in polymer matrix, are emerging as attractive platforms for advanced additive manufacturing. Unfortunately, in the currently applied techniques, the preparation of optically functionalized structures based on these photosensitized nanocomposites is still hampered by many issues like hydrolysis reaction, high-temperature calcinations, and, especially, the complexity of experimental procedures. In this study, we demonstrate a feasible strategy for fabricating micro-/nanostructures with a flexibly manipulated effective refractive index by incorporating TiO2 nanoparticles in the matrix of acrylate resin, i.e., TiO2-based photosensitized nanocomposites. It was found that the effective refractive index of nanocomposite can be easily tuned by altering the concentration of titanium dioxide nanoparticles in the monomer matrix. For TiO2 nanoparticle concentrations up to 30 wt%, the refractive index can be increased over 11.3% (i.e., altering from 1.50 of pure monomer to 1.67 at 532 nm). Based on such a photosensitized nanocomposite, the grating structures defined by femtosecond laser nanoprinting can offer vivid colors, ranging from crimson to magenta, as observed in the dark-field images. The minimum printing width and printing resolution are estimated at around 70 nm and 225 nm, indicating that the proposed strategy may pave the way for the production of versatile, scalable, and functionalized opto-devices with controllable refractive indices.

The Role of O6-methylguanine-DNA Methyltransferase Polymorphisms in Prostate Cancer Susceptibility: a Meta-Analysis.

To assess the associations between O6-methylguanine-DNA methyltransferase(MGMT) polymorphisms and prostate cancer risk. We retrieved PubMed, Cochrane Library and Embase electronic database to search for all eligible studies published from Jan 1, 1970 to Sep 31, 2017 to conduct a Meta-analysis. we identified 11 independent studies in 5 eligible reports, including 5143 cases and 8118 controls. The data suggested that rs12917 was associated with higher PCa risk under the contrast of TT vs CC and recessive model in overall population (TT vs CC: OR = 1.599, 95%CI: 1.007-2.539, P = 0.047; TT vs CC + CT: OR = 1.627, 95%CI: 1.026-2.580, P = 0.038). In subgroup analyses stratified by ethnicity, the remarkable association with higher PCa risk was detected under allelic model, dominant model, the contrast of TC vs CC, and the contrast of TC vs CC + TT in Asian population. (T vs C: OR = 1.911, 95%CI: 1.182-3.090, P = 0.008; TC vs CC: OR = 1.948, 95%CI: 1.152-3.295, P = 0.013; TC + TT vs CC: OR = 1.994, 95%CI: 1.190-3.342, P = 0.009; TC vs CC + TT: OR = 1.926, 95%CI: 1.140-3.255, P = 0.014). However, the data suggest the rs2308327 and rs2308321 polymorphisms of the MGMT gene were nor associated with the susceptibility of prostate cancer. Based on the meta-analysis, MGMT rs12917 polymorphism increase the susceptibility to prostate cancer, which can be taken for a diagnosis and screening molecular biomarker for prostate cancer patients.

Atomistic Simulation on the Twin Boundary Migration in Mg under Shear Deformation.

In this paper, the { 10 1 ¯ 2 } twinning and detwinning was studied by molecular dynamics simulation under different shear directions and strain rates. The results showed that the twin was thickened under [ 1 ¯ 011 ] shear direction and shrunken with shearing in the opposite direction. The critical resolved shear stress of { 10 1 ¯ 2 } twin boundary migration increased with the increase of the strain rate. By analyzing the atom's displacement, it was concluded that the { 10 1 ¯ 2 } twin migration was achieved by both the shear and the atomic shuffling. Every atom would be affected by the shear, and different shear directions would cause opposite move directions, which led to twinning or detwinning. The atom shuffling was only used for adjusting the glide twin boundary and mirror-symmetric twin boundary structure evolution.

MiR-1/GOLPH3/Foxo1 Signaling Pathway Regulates Proliferation of Bladder Cancer.

OBJECTIVE: To investigate role of microRNA-1/Golgi phosphoprotein 3/Foxo1 axis in bladder cancer. METHODS: The expression of Golgi phosphoprotein 3 was determined in both bladder cancer tissues and cell lines using quantitative real-time polymerase chain reaction and Western blotting, respectively. Golgi phosphoprotein 3 was knocked down by small hairpin RNA. MicroRNA-1 was overexpressed or inhibited by microRNA-1 mimic or inhibitor. Cell viability and proliferation were determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) and colony-formation assay. Cell apoptosis and cycle was detected using flow cytometer. The expression of microRNA-1 and Golgi phosphoprotein 3 was determined using quantitative real-time polymerase chain reaction and Western blotting was used to test the expression of Golgi phosphoprotein 3, Foxo1, p-Foxo1, AKT, p-AKT, p27, and CyclinD1. Binding between microRNA-1 and Golgi phosphoprotein 3 was confirmed by Dual-Luciferase Reporter Assay. RESULTS: MicroRNA-1 was downregulated in bladder cancer tissues, while Golgi phosphoprotein 3 was overexpressed in bladder cancer cells and tissues. In both bladder cancer 5637 and T24 cell lines, the cell viability and proliferation were dramatically reduced when Golgi phosphoprotein 3 was knocked down. The inhibition of Golgi phosphoprotein 3 remarkably promoted cell apoptosis and induced cell-cycle arrest, as well as decreased the expression of p-Foxo1, p-AKT, and CyclinD1 and increased the expression of p27. The overexpression of microRNA-1 significantly inhibited cell viability and proliferation, induced G-S cell-cycle arrest, and decreased the expression of Golgi phosphoprotein 3, p-Foxo1, and CyclinD1 and upregulated p27, while inhibition of microRNA-1 led to opposite results. Golgi phosphoprotein 3 was a direct target for microRNA-1. CONCLUSION: Overexpression of microRNA-1 inhibited cell proliferation and induced cell-cycle arrest of bladder cancer cells through targeting Golgi phosphoprotein 3 and regulation of Foxo1.

Theoretical design of multi-colored semi-transparent organic solar cells with both efficient color filtering and light harvesting.

Solar cells incorporated with multi-coloring capability not only offer an aesthetic solution to bridge the gap between solar modules and building decorations but also open up the possibility for self-powered colorful display. In this paper, we proposed a multi-colored semi-transparent organic solar cells (TOSCs) design containing metallic nanostructures with the both high color purity and efficiency based on theoretical considerations. By employing guided mode resonance effect, the multi-colored TOSC behave like an efficient color filter that selectively transmits light with the desired wavelengths and generates electricity with light of other wavelengths. Broad range of coloring and luminosity adjusting for the transmission light can be achieved by simply tuning the period and the duty cycle of the metallic nanostructures. Furthermore, accompanying with the efficient color filtering characteristics, the optical absorption of TOSCs was improved due to the marked suppression of transmission loss at the off-resonance wavelengths and the increased light trapping in TOSCs. The mechanisms of the light guiding in photoactive layer and broadband backward scattering from the metallic nanostructures were identified to make an essential contribution to the improved light-harvesting. By enabling efficient color control and high efficiency simultaneously, this approach holds great promise for future versatile photovoltaic energy utilization.

Great light absorption enhancement in a graphene photodetector integrated with a metamaterial perfect absorber.

A novel graphene photodetector with graphene embedded in a metamaterial perfect absorber (MPA) is proposed and its light absorption property is numerically investigated. Absorption above 40% in graphene is obtained, which is over 17 times that of a bare monolayer graphene. Both horizontally and vertically cascaded MPAs integrated with graphene are also investigated.