Flexible and transparent metadevices for terahertz, microwave, and infrared multispectral stealth based on modularization design.

Multispectral stealth technology including terahertz (THz) band will play an increasingly important role in modern military and civil applications. Here, based on the concept of modularization design, two kinds of flexible and transparent metadevices were fabricated for multispectral stealth, covering the visible, infrared (IR), THz, and microwave bands. First, three basic functional blocks for IR, THz, and microwave stealth are designed and fabricated by using flexible and transparent films. And then, via modular assembling, that is, by adding or removing some stealth functional blocks or constituent layers, two multispectral stealth metadevices are readily achieved. Metadevice 1 exhibits THz-microwave dual-band broadband absorption, with average measured absorptivity of 85% in 0.3-1.2 THz and higher than 90% in 9.1-25.1 GHz, suitable for THz-microwave bi-stealth. Metadevice 2 is for IR and microwave bi-stealth, with measured absorptivity higher than 90% in 9.7-27.3 GHz and low emissivity around 0.31 in 8-14 µm. Both metadevices are optically transparent and able to maintain good stealth ability under curved and conformal conditions. Our work offers an alternative approach for designing and fabricating flexible transparent metadevices for multispectral stealth, especially for applications in nonplanar surfaces.

Effect of bionic hexagonal texture on squeezing films inside soft contacts with high adhesion and high friction.

To understand the mechanisms of high friction and high adhesion in bioinspired textured surfaces under wet conditions, the evolution behavior of squeezing films across lubricated interfaces is experimentally investigated using optical interferometry. The results show that the splitting of the continuous large-scaled liquid film into numerous isolated micro zones is an important function of the hexagonal texture. Both the orientation and the size of the hexagonal texture have noticeable effects on the drainage rate: either downscaling the hexagonal texture or orienting the texture with two sides of each micro-hexagon parallel to the inclining direction could accelerate the draining process. While the draining process is completed, residual micro-droplets turn out to be entrapped within the contact regions of single hexagonal micro-pillars. The entrapped micro-droplets gradually shrink as the hexagonal texture downsizes. Moreover, a novel geometrical shape for the micro-pillared texture is proposed to improve the drainage efficiency.

Diflovidazin damages the hematopoietic stem cells to zebrafish embryos via the TLR4/ NF-κB/ p53 pathway.

Exposure to environmental contaminants frequently induces the occurrence of blood diseases, but the underlying molecular mechanisms are scarcely known. The toxicity of Diflovidazin (DFD), a widely used mite-remover, to the blood system of non-target organisms requires urgent elucidation. To investigate the deleterious effects of DFD (2, 2.5, and 3 mg/L) on the development and survive of hematopoietic stem cells (HSCs), the zebrafish model was used in this study. DFD exposure reduced the number of HSCs and their subtypes, including macrophages, neutrophils, thymus T-cells, erythrocytes, and platelets. The significant changes in the abnormal apoptosis and differentiation of HSCs were the major reasons for the reduction in blood cells. Using small-molecule antagonists and p53 morpholino revealed that the NF-κB/p53 pathway was responsible for the apoptosis of HSCs upon DFD exposure. The restoration results attributed to the TLR4 inhibitor and molecular docking showed that the TLR4 protein, which was upstream of NF-κB signaling, played a vital role in DFD toxicology. This study elucidates the role and molecular mechanism of DFD in damaging zebrafish HSCs. It provides a theoretical basis for the occurrence of various blood diseases in zebrafish and other organisms.

Factors associated with negative conversion of viral RNA in hospitalized children infected with SARS-CoV-2 Omicron variant in Shanghai, China: a retrospective analysis.

OBJECTIVES: This study aimed to identify the related risk factors and potential predictors of SARS-CoV-2 RNA negative conversion by describing the dynamics of viral shedding in infected children admitted to two hospitals from Shanghai during the Omicron variant outbreak. METHODS: This retrospective cohort included laboratory-confirmed cases of SARS-CoV-2 infection from Shanghai between March 28 and May 31, 2022. Clinical characteristics, personal vaccination, and household vaccination rates were collected through electronic health records and telephone interviews. RESULTS: A total of 603 paediatric patients confirmed to have COVID-19 were included in this study. Both univariate and multivariate analyses were performed to filter independent factors for the duration to viral RNA negative conversion. Data on the redetection of SARS-CoV-2 in the patients after they showed negative results on the RT‒PCR test (intermittent negative status) were also analysed. The median duration of virus shedding was 12 (interquartile range, IQR: 10-14) days. The severity of clinical outcome, personal vaccination-2doses, household vaccination rates, and abnormal defecation were factors indecently affecting negative conversion of SARS-CoV-2 RNA, suggesting that patients who had abnormal defecation or with more severe conditions would have delayed virological clearance, while patients who previously had 2 doses of vaccination or had higher household vaccination rates would have accelerated virological clearance. Loss of appetite (odds ratio (OR): 5.343; 95% CI: 3.307-8.632) and abnormal defecation (OR: 2.840; 95% CI: 1.736-4.645) were significantly associated with intermittent negative status. CONCLUSION: These findings could provide clues for the early identification of paediatric patients with prolonged viral shedding and could enrich the evidence for the development of prevention and control strategies, especially vaccination policies for children and adolescents.

Flexible and transparent broadband microwave metasurface absorber based on multipolar interference engineering.

Electromagnetic multipoles enable rich electromagnetic interactions in a metasurface and offer another degree of freedom to control electromagnetic responses. In this work, we design and experimentally demonstrate an optically transparent, flexible and broadband microwave metasurface absorber based on multipolar interference engineering. Different from previous works, the designed metasurface simultaneously supports fundamental electric dipole and high-order electric quadrupole mode, whose interference satisfies the back-scattering suppression condition based on the generalized Kerker effect and thus high absorption. The measurement results indicate that the fabricated metasurface exhibits a high average absorption of 89% in the microwave band from 4 GHz to 18 GHz, together with a good optical transparency. Our study offers an alternative approach for designing broadband microwave metasurface absorber, which is potentially applicable in electromagnetic shielding, radar stealth and energy harvesting.

Wide-waveguide high-power low-RIN single-mode distributed feedback laser diodes for optical communication.

We present an 8-µm-wide 800-µm-long high-power, single-mode and low RIN DFB laser using a dual-waveguide structure. The introduced passive lower waveguide has weakenes the lateral optical confinement for the ridge waveguide, and thus reduces losses caused by the p-doped layers and maintains single mode stability of the laser. The fabricated laser exhibited an output power higher than 170 mW and a relative intensity noise (RIN) below -157 dB/Hz along with a side-mode suppression-ratio (SMSR) over 55 dB. The temperature tuning from -10°C to 60°C allows an 8.6 nm wavelength tunability with a variation coefficient of 0.12 nm/K. The relaxation oscillation frequency is around 8 GHz, and the linewidth is about 250 kHz at 100 mW output power for the fabricated laser. The characteristics of the proposed high-power laser, including high slope efficiency, single mode stability and low noise, make it a suitable candidate for optical communication.

Bifocal focusing and polarization demultiplexing by a guided wave-driven metasurface.

Metasurfaces have shown extraordinary light-manipulation abilities, however, most of them deal with free-space waves. It is highly desirable to develop a guided wave-driven metasurface which can extract the in-plane guided modes in the waveguide and mold it into the desired out-of-plane free-space modes. In this paper, an all-dielectric guided wave-driven metasurface, composed of an array of silicon meta-atoms on top of a silicon nitride waveguide, is proposed and simulatively demonstrated. When directly driven by fundamental transverse electric (TE00) and fundamental transverse magnetic (TM00) guided modes at operation wavelength 1.55 µm, the guided wave-driven metasurface converts them into y-polarized and x-polarized free-space light, respectively, and focuses them at different focal points, with polarization extinction ratio over 27 dB, thus simultaneously realizing triple functions of coupling guided modes to free-space waves, bifocal metalens and polarization demultiplexing. Our work offers an alternate way to control light across photonic integrated devices and free-space platforms.

Simultaneous realization of electromagnetically induced transparency and electromagnetically induced reflectance in a metasurface.

The analogue of electromagnetically induced transparency (EIT-like) and electromagnetically induced reflectance (EIR-like) effects have been intensively studied and achieved by using metasurfaces. Nevertheless, previous designs could realize only one of them and were unable to support both effects in a metasurface. Here we numerically and experimentally demonstrate a metasurface simultaneously exhibiting EIT-like and EIR-like effects. Qualitative analyses and quantitative calculations based on the electromagnetic multipole decomposition method are performed to reveal their formation mechanisms. Our work offers a simple avenue for simultaneously realizing EIT-like and EIR-like effects in a metasurface, which may find potential applications in sensing, filtering, and slow wave devices.

Mechanism and performance analyses of optical beam splitters using all-dielectric oligomer-based metasurfaces.

Compact and planar optical beam splitters are highly desirable in various optical and photonic applications. Here, we investigate two kinds of optical beam splitters by using oligomer-based metasurfaces, one is trimer-based metasurface for 3-dB beam splitting, and the other is pentamer-based metasurface for 1:4 beam splitting. Through electromagnetic multipole decomposition and in-depth mechanism analyses, we reveal that the electromagnetic multipolar interactions and the strong near-field coupling between neighboring nanoparticles play critical roles in beam-splitting performance. Our work offers a deeper understanding of electromagnetic coupling effect in oligomer-based metasurfaces, and provides an alternative approach to planar beam splitters.

Optical rotation and electromagnetically induced transparency in a chiral metamaterial with C4 symmetry.

We design and fabricate a double-layered chiral metamaterial with 4-fold rotational symmetry, which simultaneously exhibits optical rotation and electromagnetically induced transparency (EIT) effects. Using analytical equivalent circuit model and Lorentz's coupled oscillator model, we interpret the physical mechanisms and derive material equations. Importantly, we find that magnetic dipole and electric quadrupole play important roles in optical rotation and keeping the symmetry of the material equations. Our work offers a better understanding of optical rotation in chiral metamaterials, and provides a new and simple approach to combine optical rotation and EIT effects into a single metamaterial.

Dexmedetomidine suppresses the progression of esophageal cancer via miR-143-3p/epidermal growth factor receptor pathway substrate 8 axis.

Esophageal cancer is one of the fatal cancers around the world. Dexmedetomidine (DEX) is widely used during anesthesia of esophageal cancer surgery. Nevertheless, the role of DEX in the progression of esophageal cancer remains barely known. The proliferation, apoptosis and metastasis of esophageal cancer cells were detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, transwell migration and invasion assays and Western blot assay. The expression of miR-143-3p was measured by quantitative real-time PCR in esophageal cancer tissues and cells. The binding sites between miR-143-3p and epidermal growth factor receptor pathway substrate 8 (EPS8) were predicted by Starbase online software, and the combination was verified by dual-luciferase reporter assay. The murine xenograft model was established using KYSE150 cells to verify the function of DEX in vivo. DEX inhibited the proliferation and metastasis while accelerated the apoptosis of esophageal cancer cells. The abundance of miR-143-3p was lower in esophageal cancer tissues and cells than that in paring normal tissues and normal esophageal mucosal cells Het-1A. MiR-143-3p could be induced by DEX treatment in esophageal cancer cells, and miR-143-3p also suppressed the development of esophageal cancer. EPS8 was a functional target of miR-143-3p, and it played an oncogenic role in esophageal cancer. DEX inhibited the growth of tumor via miR-143-3p/EPS8 in vivo. DEX suppressed the growth and metastasis while facilitated the apoptosis of esophageal cancer cells through upregulating the abundance of miR-143-3p and reducing the level of EPS8 in vivo and in vitro, providing promising target for the treatment of esophageal cancer.

Fli-1 Activation through Targeted Promoter Activity Regulation Using a Novel 3', 5'-diprenylated Chalcone Inhibits Growth and Metastasis of Prostate Cancer Cells.

The friend leukemia integration 1 (Fli-1) gene is involved in the expression control of key genes in multiple pathogenic/physiological processes, including cell growth, differentiation, and apoptosis; this implies that Fli-1 is a strong candidate for drug development. In our previous study, a 3',5'-diprenylated chalcone, (E)-1-(2-hydroxy-4-methoxy-3,5-diprenyl) phenyl-3-(3-pyridinyl)-propene-1-one (C10), was identified as a novel anti-prostate cancer (PCa) agent. Here, we investigated the molecular mechanisms underlying the anti-cancer effects of C10 on the growth, metastasis, and invasion of PC3 cells in vitro. Our results show that C10 exhibited a strong inhibitory effect on proliferation and metastasis of PC3 cells via several cellular and flow cytometric analyses. Further mechanism studies revealed that C10 likely serves as an Fli-1 agonist for regulating the expression of Fli-1 target genes including phosphatidylinositol 3-kinase (P110), murine double minute2 (MDM2), B-cell lymphoma-2 (Bcl-2), Src homology-2 domain-containing inositol 5-phosphatase 1 (SHIP-1), and globin transcription factor-1 (Gata-1) as well as the phosphorylation of extracellular-regulated protein kinases 1 (ERK1). Further, we confirmed that C10 can regulate the expressions of vascular endothelial growth factor 1 (VEGF-1), transforming growth factor-ß2 (TGF-ß2), intercellular cell adhesion molecule-1 (ICAM-1), p53, and matrix metalloproteinase 1 (MMP-1) genes associated with tumor apoptosis, migration, and invasion. Thus, C10 exhibits stronger anticancer activity with novel molecular targets and regulatory molecular mechanisms, indicating its great potency for development as a novel targeted anticancer drug.

Narrow-band and high-contrast asymmetric transmission based on metal-metal-metal asymmetric gratings.

A narrow-band and high-contrast asymmetric transmission (AT) device based on metal-metal-metal (M-M-M) asymmetric grating structure is proposed and investigated. Significantly distinct from previous reports, the upper and lower metallic silver (Ag) gratings are connected by a very thin metallic Ag film, without any dielectric spacer layer or subwavelength slit. Under forward incidence, the M-M-M structure supports efficient surface plasmon polaritons (SPPs) excitation and tunneling, more importantly, it promotes direct and thus high-efficiency SPPs decoupling, enabling high forward transmittance. While under backward incidence, the M-M-M structure offers not only high reflection by the Ag film but also a strong near-field coupling effect between the upper and lower gratings, which further suppresses backward transmittance, leading to near-zero backward transmittance. In addition, the M-M-M structure is optimized for narrow-band operation by employing grating groove depth effect and multiple interference effect. Numerical simulation results demonstrate that high-performance AT with high-quality factor (Q≈91), narrow-bandwidth (6.7 nm) and high contrast ratio is achieved, with forward transmittance of 0.72 and backward transmittance of 0.0015 at visible light (610 nm). Our work provides an alternative and simple way to high-performance AT devices.

Dual-band asymmetric optical transmission of both linearly and circularly polarized waves using bilayer coupled complementary chiral metasurface.

It is highly desirable to develop asymmetric transmission (AT) devices for both linearly and circularly polarized light. However, currently existing metamaterial-based AT devices require multi-step micro-nano fabrication processes and usually realize AT responses only for linearly or circularly polarized waves, not simultaneously for both. We here propose a dual-band AT device for both linearly and circularly polarized waves in the near-infrared region by using a bilayer coupled complementary chiral metasurface, which includes a half-gammadion-shape gold (Au) structural layer and its Babinet's complimentary copy. Unlike other multilayer AT devices working at optical frequencies, it takes less micro-nano fabrication steps. Besides, with the help of chirality and the inherent near-field coupling effect between the two complementary Au layers, the maximal AT parameters for linearly and circularly polarized waves can reach up to 0.45 and 0.56, respectively. The underlying mechanisms of dual-band AT responses are also investigated in depth from the perspectives of chirality and coupling effect. Our work offers a new and simple approach to high-performance AT devices, helps to better understand near-filed coupling effect in coupled complementary metasurfaces, and also expands their application fields.

USP10 inhibits lung cancer cell growth and invasion by upregulating PTEN.

To determine the potential tumor suppressor functions of ubiquitin-specific protease 10 (USP10) in lung cancer and elucidate underlying molecular mechanism. The relative expression of USP10 was determined by real-time PCR and immunoblotting. The inhibitory effect of USP10 on tumor growth was demonstrated on allograft mice with Lewis carcinoma cell inoculation. The relative cell proliferation was measured with Cell Counting Kit-8 (CCK-8). The invasive capacity was evaluated by transwell assay. The interaction between USP10 and Phosphatase And Tensin Homolog (PTEN) was examined by co-immunoprecipitation. Ubiquitination/deubiquitination was analyzed by immunoprecipitation followed by immunoblotting. USP10 was down-regulated in lung cancer. Knockdown of USP10 promotes tumor growth and invasion both in vitro and in vivo. We further demonstrated that USP10 directly interacted with and stabilized PTEN via deubiquitination. The pro-cancerous effect of USP10 deficiency was abolished by re-introduction of PTEN. We suggested a tumor suppressor function of USP10 in lung cancer via deubiquitinating and stabilizing PTEN.

Asymmetric optical transmission based on unidirectional excitation of surface plasmon polaritons in gradient metasurface.

Asymmetric optical transmission is fundamental and highly desirable in information processing and full manipulation of lightwave. We here propose an asymmetric optical transmission device consisting of a gradient metasurface and a one-dimensional subwavelength grating. Owing to the unidirectional excitation of surface plasmon polaritons (SPPs) by the gradient metasurface, and SPP-assisted extraordinary optical transmission, forward incident light has much higher transmission than the backward one. We combine temporal coupled mode theory and finite-difference time-domain simulations to verify its operation principle and study the performance. The results indicate that asymmetric transmission with high-contrast and large forward transmittance can be obtained around the 1.3 µm optical communication band.

Coupling-based Huygens' meta-atom utilizing bilayer complementary plasmonic structure for light manipulation.

Huygens' meta-atom is the basic building unit of Huygens' metasurfaces allowing for almost arbitrary wavefront shaping across a surface. We here present a kind of Huygens' meta-atom by coupling a nanodisk to its Babinet-complementary structure (nanohole), and develop an optical lumped nanocircuit model to analyze vertical and lateral coupling effects and resonance frequencies. Simulation results show that the tuned coupling via lateral misalignment between the two nanostructures is sufficient to shape the wavefront without changing the dimensions or orientations of antennas. By tuning the coupling via lateral misalignment, we design a reflective gradient metasurface based on one coupled mode and a high-efficiency transmissive gradient metasurface working in the spectral overlap of electric and magnetic resonances to realize beam deflection. The proposed coupling-based Huygens' meta-atom is a new building block for plasmonic metasurfaces with enhanced light-matter interactions, high-efficiency and almost arbitrary wavefront shaping over the full electromagnetic spectrum.

Polarization-switchable and wavelength-controllable multi-functional metasurface for focusing and surface-plasmon-polariton wave excitation.

Realizing versatile functionalities in a single photonic device is crucial for photonic integration. We here propose a polarization-switchable and wavelength-controllable multi-functional metasurface. By changing the polarization state of incident light, its functionality can be switched between the flat focusing lens and exciting surface-plasmon-polariton (SPP) wave. Interestingly, by tuning the wavelength of incident light, the generated SPP waves can also be controlled at desired interfaces, traveling along the upper or lower interface of the metasurface, or along both of them, depending on whether the incident light satisfies the first or second Kerker condition. This polarization-switchable and wavelength-controllable multifunctional metasurface may provide flexibility in designing tunable or multifunctional metasurfaces and may find potential applications in highly integrated photonic systems.

Potent Inhibition of miR-34b on Migration and Invasion in Metastatic Prostate Cancer Cells by Regulating the TGF-ß Pathway.

The importance of miRNAs in the progression of prostate cancer (PCa) has further been supported by the finding that miRNAs have been identified as potential oncogenes or tumor suppressors in PCa. Indeed, in eukaryotes, miRNAs have been found to regulate and control gene expression by degrading mRNA at the post-transcriptional level. In this study, we investigated the expression of miR-34 family members, miR-34b and miR-34c, in different PCa cell lines, and discussed the molecular mechanism of miR-34b in the invasion and migration of PCa cells in vitro. The difference analyses of the transcriptome between the DU145 and PC3 cell lines demonstrated that both miR-34b and -34c target critical pathways that are involved in metabolism, such as proliferation, and migration, and invasion. The molecular expression of miR-34b/c were lower in PC3 cells. Moreover, over-expression of miR-34b/c in PC3 cells caused profound phenotypic changes, including decreased cell proliferation, migration and invasion. Moreover, the players that regulate expression levels of transforming growth factor-ß (TGF-ß), TGF-ß receptor 1 (TGF-ßR1), and p53 or phosphorylation levels of mothers against decapentaplegic 3 (SMAD3) in the TGF-ß/Smad3 signaling pathway have yet to be elucidated, and will provide novel tools for diagnosis and treatment of metastatic PCa.

Manipulating the wavefront of light by plasmonic metasurfaces operating in high order modes.

In this work, plasmonic metasurfaces with abrupt phase discontinuities operating in high order modes are investigated for manipulating the wavefront of light. We first design two types of meta-super-cells consisting of V-shaped antennas with the phase shift coverage larger than 2π. And then, we create two linear gradient phased metasurfaces using the designed cells, which exhibit exceptional abilities for light-steering functioned as meta-echelette gratings operating in high order diffraction modes, may be valuable for using in high resolution spectrographs and advantage to achieve high numerical aperture plasmonic lenses. Based on the new designed super cells we further build another two azimuthal gradient phased metasurfaces that are able to generate high order optical vortex beams. Our results could lead to wide applications in photonic research.