Quasi-bound states in the continuum empowering a transmissive terahertz narrowband filter with high Q and a broad sideband free of interferential distortion.

Most currently available terahertz (THz) narrowband filters contain a metal and a substrate, which introduce absorption loss and spectral fluctuations caused by a Fabry-Perot interference in substrates. To address these issues, we employ quasi-bound states in the continuum (BICs) for the design and realization of a substrate-free all-dielectric THz transmissive narrowband filter. Under oblique incidence, the symmetry-protected BICs break and collapse into high-Q transmissive quasi-BIC modes, thereby achieving narrowband filtering. The filter not only minimizes energy loss but also demonstrates a smooth filtering response without an interferential spectral fluctuation associated with the substrate. An experimental high Q value of ∼127 at 4.1 THz with a broad sideband of ∼1.5 THz with transmittance below 10% is achieved.

Polarization- and angle-insensitive broadband long wavelength infrared absorber based on coplanar four-sized resonators.

In many potential applications, there is a high demand for long wavelength infrared (LWIR) absorbers characterized by a compact configuration, broad operational bandwidth, high absorption efficiency, and polarization- and angle-insensitive characteristics. In this study, we design and demonstrate a high-performance broadband LWIR absorber based on coplanar four-sized resonators, consisting of arrays of titanium (Ti) disks with different diameters supported by a continuous zinc selenide (ZnSe) layer and by a Ti film acting as a back-reflector. Particle swarm optimization (PSO) is employed to optimize the complicated geometry parameters, and the final optimized device exhibits near-unity absorption (∼96.7%) across the entire operational bandwidth (8 µm∼14 µm) under unpolarized normal incidence, benefiting from the impedance-matching condition and the multiple surface plasmon resonances of this configuration. Furthermore, the proposed absorber is insensitive to the angle of incidence due to the localized surface plasmon resonances supported by these four-sized resonators, and is insensitive to the state of polarization thanks to the highly symmetric feature of the circular pattern. The measured absorption of the fabricated sample exhibits a relatively high coincidence with the simulation, with an average absorption of 88.9% ranging from 8 µm to 14 µm. The proposed absorber, which can be easily integrated into a standardized micro/nano manufacture process for cost-effective large-scale production, provides a feasible solution for improving optical performance in thermal emitter, infrared detection, and imaging applications. Furthermore, the generalized design principle employing the optimized method opens up new avenues for realizing target absorption, reflection, and transmission based on more complicated structure configurations.

THz transmissive all-dielectric guided-mode resonance filter with high Q and tunability using suspended gratings.

Most currently available THz narrowband filters employ metal that introduces loss, or work in reflection mode, which limits their scope of application. Here, a transmissive all-dielectric guided-mode resonance filter in the THz region is presented. It contains a suspended grating layer and a waveguide layer, separated by an air layer. A fabrication process of the filter is proposed. Simulation results show that the designed filter exhibits excellent transmittance of ∼97.5% with a high Q value of ∼1500 at 1.64 THz. Furthermore, this transmission peak is surrounded by a wide and flat sideband with width of ∼0.75T H z and transmission below 10%. Moreover, tunability of the filter is realized by geometric scaling and by varying the thickness of the air layer. Using geometric scaling, the filtering frequency can be widely tuned from 0.54 to 1.64 THz, covering the 625-725 and 780-910 GHz wireless communication windows. Additionally, fine tuning achieved by varying the air layer thickness could be used to compensate for a tiny shift of the designed filtering frequency caused by errors introduced in the fabrication process. The Q value can be further boosted to ∼11,500 by adding another layer of waveguide. Due to its transmissive nature and high-Q resonant mode with a wide sideband and tunability, the presented filter exhibits great potential in THz applications such as spectroscopy, imaging, and communication.

Interleukin-1 receptor antagonist inhibits matastatic potential by down-regulating CXCL12/CXCR4 signaling axis in colorectal cancer.

BACKGROUND: The aim of this study was to investigate the co-operative role of CXCR4/CXCL12 axis and IL-1Ra in metastatic processes mechanism by interactions between colorectal cancer cells and stromal cells in their microenvironment. METHODS: Expression of IL-1α, interleukin-1 receptor type I (IL-1 RI), CXCL12 and CXCR4 mRNA and proteins were determined by RT-PCR and Western blot. The effect of secreted level of CXCL12 by IL-1Ra on fibroblasts was measured by ELISA. CXCL12 regulate metastatic potential of colorectal cancer was evaluated by proliferation, invasion and angiogenesis assays, respectively, in which invasion and angiogenesis assays used an in vitro system consisting of co-cultured colorectal cells and stromal cells. RESULTS: IL-1α was expressed in high liver metastatic colorectal cancer cell lines (HT-29 and WiDr). The colorectal cancer cell-derived IL-1α and rIL-1α significantly promoted CXCL12 expression by fibroblasts, and this enhancing effect can be significantly inhibited by IL-1Ra (P < 0.01). CXCL12 not only enhanced the migration and proliferation of human umbilical vein endothelial cells, but also significantly enhanced angiogenesis (P < 0.01). Furthermore, the high liver-metastatic colorectal cancer cell line (HT-29), which secretes IL-1α, significantly enhanced angiogenesis compared to the low liver-metastatic cell line (CaCo-2), which does not produce IL-1α (P < 0.01). On the contrary, IL-1Ra can significantly inhibit migration, proliferation and angiogenesis (P < 0.01). CONCLUSION: Autocrine IL-1α and paracrine CXCL12 co-enhances the metastatic potential of colorectal cancer cells; IL-1Ra can inhibit the metastatic potential of colorectal cancer cells via decrease IL-1α/CXCR4/CXCL12 signaling pathways. Video Abstract.

Genome-wide association and differential expression analysis of salt tolerance in Gossypium hirsutum L at the germination stage.

BACKGROUND: Salinity is a major abiotic stress seriously hindering crop yield. Development and utilization of tolerant varieties is the most economical way to address soil salinity. Upland cotton is a major fiber crop and pioneer plant on saline soil and thus its genetic architecture underlying salt tolerance should be extensively explored. RESULTS: In this study, genome-wide association analysis and RNA sequencing were employed to detect salt-tolerant qualitative-trait loci (QTLs) and candidate genes in 196 upland cotton genotypes at the germination stage. Using comprehensive evaluation values of salt tolerance in four environments, we identified 33 significant single-nucleotide polymorphisms (SNPs), including 17 and 7 SNPs under at least two and four environments, respectively. The 17 stable SNPs were located within or near 98 candidate genes in 13 QTLs, including 35 genes that were functionally annotated to be involved in salt stress responses. RNA-seq analysis indicated that among the 98 candidate genes, 13 were stably differentially expressed. Furthermore, 12 of the 13 candidate genes were verified by qRT-PCR. RNA-seq analysis detected 6640, 3878, and 6462 differentially expressed genes at three sampling time points, of which 869 were shared. CONCLUSIONS: These results, including the elite cotton accessions with accurate salt tolerance evaluation, the significant SNP markers, the candidate genes, and the salt-tolerant pathways, could improve our understanding of the molecular regulatory mechanisms under salt stress tolerance and genetic manipulation for cotton improvement.

Spectral characteristics of a guided mode resonant filter with planes of incidence.

Spectral responses of the guided mode resonant filter under different planes of incidence are comprehensively investigated in this paper. Commercially available software based on the rigorous coupled wave analysis method is used to perform the reflectance spectra. For normal incidence, there exists a pair of resonance bands, whose diffraction efficiencies can be tuned from 3.5% to 100% and 3.2% to 100% without shifting the resonant location as the plane of incidence (POI) angle ranges from 0° to 90°, whereas the resonances split into two branches as the POI angle decreases from 90° to 0° for oblique incidence. There exists a crossing point between the split bands that is proved to be polarization independent. Moreover, the physical mechanism of the above spectral characteristics is analyzed in detail by means of the wave vectors. The intensity-tunable feature under normal incidence can be used in the field of bioactive fluorescent protein dyes, displays, and signal processing. And the split characteristic under oblique incidence is applied to seek the polarization-independent wavelength, which has potential applications in the field of dense wavelength division multiplexing and laser devices.

Structural and optical characteristics of the hexagonal ZnO films grown on cubic MgO (001) substrates.

In this Letter, we report on the structural and optical characteristics of ZnO films with a wurtzite structure grown on MgO (001) substrates with cubic structures. The ZnO films were prepared through the molecular beam epitaxy method, and growth orientation transformation from [0001] to [10-10] direction was observed with the change of growth temperature and thickness. The x-ray diffraction pole figures and in situ RHEED patterns demonstrated that the rotational relationship among grains within the ZnO films appeared in a typical two-fold rotation of about 30° for the [0001] growth orientation and four-fold rotation of about 30° or 60° for the [10-10] growth orientation, respectively. Last, we investigated their optical properties through measuring the transmission and photoluminescence spectra of the ZnO films, which showed the bulk-like bandgap feature of the ZnO films in spite of the existing growth orientation transformation.

Improvement in efficiency of micromorph tandem silicon solar cells by designing proper interfaces.

Efficient light management for micromorph tandem solar cells is achieved in this Letter by the combined application of TiO(2) and SiO(x) interlayers. Here, TiO(2) is incorporated into a ZnO/a-Si interface as an antireflection layer and SiO(x) is incorporated into an a-Si/µc-Si interface as an intermediate reflecting layer. Solar cells with such architecture not only increase the light absorption but also reduce the mismatch losses of current between the top and bottom cells. The key results, as evidenced by the spectral response measurements, are that the total photocurrent increases from 22.62 to 24.35 mA/cm(2), as well as the short circuit current density of the two component cells is reached to a delicate balance. The influences of the interlayer thickness and morphology on the improvement have been investigated using an electromagnetic simulation in order to take full advantage of this design.

Performance enhancement in a-Si:H/µc-Si:H tandem solar cells with periodic microstructured surfaces.

Here we report on an efficient light-coupling scheme with a periodic microstructured surface to enhance the performance of thin film silicon solar cells. The centerpiece of the surface structure is the hemispherical pit arrays (HPAs), which are fabricated using an inexpensive and scalable process. The integration of HPAs into micromorph tandem thin film silicon solar cells leads to superior broadband reflection suppression properties. With this design, the reflection losses of the tandem cell are reduced to only 1.5%. We demonstrate an efficiency increase from 11.67% to 12.23% compared to a conventional cell with a flat surface, with a 4.6% increase in short circuit current density. The surface microstructures reported here can be applied to a variety of photovoltaic devices to further improve their performance.

Concave Version Printing of High-Performance Polymer THz Filters.

The development of high Q and tunable narrowband filters that can efficiently manipulate THz beams is critical for various THz applications, such as imaging and sensing. However, for filters made of metals and dielectrics, issues such as high losses, limited tunability, and lengthy process flows exist. Here, a scalable concave version reprinting technique to mass produce high-performance microstructured polymer filters is presented. The technique is extremely simple, eliminating the demand for the use of any large equipment including injection molding and thermal press printing machines, and is reliable; in the reprinted structures, there are no defects including gaps and air bubbles. The produced narrowband filters exhibit a high Q factor of 57 with wide tunability over the THz band from ∼80 to 160 µm in wavelength. The presented technique can be adopted to realize other devices as well using polymer materials with simplicity and high precision.

Ultrahigh-Q Polarization-Independent Terahertz Metamaterial Absorber Using Pattern-Free Graphene for Sensing Applications.

In contrast to noble metals, graphene exhibits significantly lower loss, especially useful for optical sensing applications that require ultrahigh Q factors, and offer wide range tunability via an adjustable Fermi level. However, precise graphene patterning is difficult, especially for large areas, severely limiting its applications. Here, a tunable terahertz metamaterial absorber (TMMA) with ultrahigh Q factors consisting of a continuous, pattern-free graphene is demonstrated. A graphene sheet is overlaid on an Al metal array, forming a structure that supports strong localized surface plasmon polaritons (LSPPs) with fields tightly confined in the graphene, minimizing loss. Theoretical results show that this TMMA exhibits an ultrahigh Q factor of 1730, a frequency sensitivity of 2.84 THz/RIU, and an excellent figure of merit (FoM) of 365.85 RIU-1, independent of polarization. A tunability from ~2.25 to ~3.25 THz is also achieved by tuning Ef of graphene from 0.3 to 0.7 eV. The proposed graphene-based TMMA holds many potential applications, particularly in the field of sensing.

Analysis of the effect of Ivor-Lewis esophagectomy and McKeown esophagectomy on perioperative anxiety and depression in patients with esophageal cancer.

To compare the effects of Ivor-Lewis esophagectomy and McKeown esophagectomy on perioperative anxiety and depression in patients with esophageal cancer. Sixty-three patients with stage I-III middle and lower esophageal carcinoma from June 2021 to December 2022 were randomly divided into observation group (n = 32) treated with laparoscopic Ivor-Lewis esophagectomy and control group (n = 31) treated with laparoscopic McKeown esophagectomy. Self-Rating Depression Scale (SDS) and Self-Rating Anxiety Scale (SAS) were measured on the second day of admission and the fifth day after surgery to assess the presence of depression and anxiety. The preoperative and postoperative clinical data of both groups were compared, and multivariate analysis was used to identify risk factors associated with depression and anxiety in patients with esophageal cancer. There was no significant difference in SDS and SAS standard scores between the observation group and the control group ( P  > 0.05). The postoperative SDS and SAS scores in the control group were significantly higher than those before and after operation in the observation group ( P  < 0.01). According to univariate analysis, patients with TNM stage III, tumor diameter greater than 3 cm, postoperative complications, radical McKeown esophagectomy, and C-reactive protein levels above 10 mg/L had a higher incidence of depression and anxiety ( P  < 0.05). Multivariate logistic analysis showed that TNM stage III (depression: OR 1.683, 95 CI 1.429-1.861; Anxiety: OR 1.739, 95 CI 1.516-1.902), postoperative complications (depression: OR 2.345, 95 CI 1.435-3.891; Anxiety: OR 1.872, 95 CI 1.372-3.471), surgical approach (depression: OR 1.609, 95 CI 1.502-3.193; Anxiety: OR 1.658, 95 CI 1.469-2.059), and C-reactive protein (depression: OR 2.260, 95 CI 1.157-4.059; Anxiety: OR 0.373, 95 CI 0.253-0.976) were all independent factors for depression and anxiety in patients after esophageal cancer surgery ( P  < 0.05). The Ivor-Lewis esophagectomy has the advantages of fewer complications and low inflammatory response, which can help alleviate anxiety and depression and improve patients' quality of life and prognosis.

Method for fabricating micro/nanostructures via scanning probe microscope and anisotropic wet etching.

The direct modification of silicon, other semiconductors and metal surfaces by the process of local anodic oxidation via electric field from scanning probe microscope (SPM) in conjunction with the absorbed water in atmosphere as the electrolyte is a promising method for fabricating micro/nanostructures. We demonstrated that the process of SPM oxidation and anisotropic wet chemical etching is a low cost and reliable method to produce smooth and uniform etched structures on silicon substrates. Using silicon oxide nanopatterns produced on H-passivated (110) Si surfaces as etching masks, and due to the large (110)/(111) anisotropic ratio of etching rate and the large Si/SiO2 etching selectivity at a relatively low etching temperature and an optimal concentration of aqueous KOH etchant, high-aspect-ratio grating structures have been fabricated by anisotropic wet etching. The approach of combining scanning probe lithography (SPL) with etching technique provides an alternative lithography route to fabricate functional nanophotonic or nanoelectronic devices.

Identification of ZmBK2 Gene Variation Involved in Regulating Maize Brittleness.

Maize stalk strength is a crucial agronomic trait that affects lodging resistance. We used map-based cloning and allelic tests to identify a maize mutant associated with decreased stalk strength and confirmed that the mutated gene, ZmBK2, is a homolog of Arabidopsis AtCOBL4, which encodes a COBRA-like glycosylphosphatidylinositol (GPI)-anchored protein. The bk2 mutant exhibited lower cellulose content and whole-plant brittleness. Microscopic observations showed that sclerenchymatous cells were reduced in number and had thinner cell walls, suggesting that ZmBK2 affects the development of cell walls. Transcriptome sequencing of differentially expressed genes in the leaves and stalks revealed substantial changes in the genes associated with cell wall development. We constructed a cell wall regulatory network using these differentially expressed genes, which revealed that abnormal cellulose synthesis may be a reason for brittleness. These results reinforce our understanding of cell wall development and provide a foundation for studying the mechanisms underlying maize lodging resistance.

Near-field observation of anomalous optical propagation in photonic crystal coupled-cavity waveguides.

An air-bridged silicon-based photonic crystal coupled-cavity waveguide (PCCCW) connected with an input and output W1 PC waveguide (PCW) was designed and fabricated. We mapped its intensity distributions with a near-field scanning optical microscope (NSOM) at near-infrared wavelengths around 1550 nm. Surprisingly, the intensity distributions demonstrate that the second odd eigenmode dominates in such a PCCCW, even though it possesses a much slower group velocity of light than that of the first even one. Further considering the measured transmission spectrum, we find that the modal profile and impedance matching between the eigenmodes in the PCW and PCCCW plays an important role in the optical propagation efficiency. Mode conversion between the first even and the second odd eigenmode was also detected at the interfaces between the W1 PCW and PCCCW.

Nanolithography in the quasi-far field based on the destructive interference effect of surface plasmon polaritons.

On the principle of phase-shift mask, the metal segment of a sub-wavelength Ag grating on a quartz substrate is used as a phase-shifting layer in this photolithography method. When the radiation modes of the surface plasmon polaritons (SPPs) excited on the Ag surface have optical phase opposite to that of the waves emitting from the slits, destructive interference occurs and the diffraction limit can be broken through. The SPPs excited on the surface between Ag and water can be transformed into propagation modes in the photoresist. Therefore, nanolithography can be achieved in the quasi-far field with this method.

The Long Non-Coding RNA NEAT1 Promotes Gastric Cancer Cell Proliferation and Invasion by Regulating miR-103a/ STAMBPL1 Axis.

BACKGROUND: Gastric cancer (GC) is a common malignancy with high morbidity. Long non-coding RNAs (LncRNAs) have been demonstrated to be critical post-transcriptional regulators in tumorigenesis. This study aimed to investigate the effect of LncRNA NEAT1 on the proliferation and metastasis of GC. MATERIAL AND METHODS: The expression of LncRNA NEAT1 was examined in clinical samples and GC cell lines. GC cell lines (SGC-7901 and BGC-823) and human normal gastric epithelial cell line (GES-1) were employed. The correlation between NEAT1, miR-103a and STAMBPL1 was determined by luciferase reporter assay. Cell viability was determined by CCK8 assay. Cell invasion capacity was examined by Transwell assay. The protein level of STAMBPL1 was analyzed by western blotting. RESULTS: LncRNA NEAT1 was found to be up-regulated in GC cell lines. Further studies identified LncRNA NEAT1 as a direct target of miR-103a. Moreover, NEAT1 knockdown and miR-103a overexpression inhibited cell proliferation and cell invasion. NEAT1 knockdown and miR-103a overexpression also decreased STAMBPL1 levels. CONCLUSION: Our study indicated that LncRNA NEAT1 was up-regulated in GC cells and tissues. NEAT1 was targeted and inhibited by miR-103a and acted as an oncogene, which promoted the malignant behavior of GC cells. This regulatory effect of NEAT1 may be associated with STAMBPL1. Therefore, NEAT1 could be used as a biomarker for predicting the progression of GC.

The role of DOT1L in the proliferation and prognosis of gastric cancer.

BACKGROUND: Disruptor of telomeric silencing-1-like (DOT1L), a methyltransferase of H3K79, was observed to be amplified and overexpressed in certain malignancies. This work was aimed at investigating the differences in DOT1L expression and its regulatory mechanism in gastric cancer (GC) and healthy samples. METHODS: Immunohistochemistry was used to detect DOT1L levels in 101 cases of GC and marching adjacent normal tissues. DOT1L was inhibited by small interfering RNA (siRNA) and EPZ5676; a targeting drug. The ability of cells to proliferate were checked by cell counting kit-8 (CCK-8) and clone formation assays, with flow cytometry for observing the cell cycle. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot revealed the gene and protein profiles. Finally, the outcome of EPZ5676 administration was checked on a murine model. RESULTS: The expression of DOT1L is significantly increased in gastric malignant tumors that is related to the degree of differentiation, lymph node metastasis and TNM staging. DOT1L serves as an independent marker for the prognosis of overall survival (OS) with high levels implying worse prognosis. In addition, DOT1L regulates cyclin-dependent kinase (CDK) 4 (CDK4) and CDK6 through H3K79me2, which leads to a change in the cell cycle at G1, thereby affecting the proliferation of tumors in vitro and in vivo. CONCLUSIONS: This is a first clinical demonstration of the applicability of DOT1L overexpression in gastric tumors. The work is suggestive of altered proliferation of cells by DOT1L via regulating cyclins and H3K79 methylation. This indicates the role of DOT1L in the prognosis and possible medical intervention of GC.

Near-infrared light harvesting of upconverting NaYF4:Yb3+/Er3+-based amorphous silicon solar cells investigated by an optical filter.

The wastage of near-infrared light seriously restricts the photoelectric conversion efficiency of hydrogenated amorphous silicon (a-Si:H) thin film solar cells. Spectral upconversion is of great significance in reducing the wastage. Herein, the upconverting compound NaYF4:Yb3+/Er3+ was synthesized via a hydrothermal method. SEM and XRD results revealed the morphology and a phase transition from cubic to hexagonal NaYF4. Photoluminescence spectra indicated that the hexagonal NaYF4:Yb3+/Er3+ nanorods convert near-infrared light of 980 nm to the visible light with wavelength peaks at 654, 541 and 522 nm. Hence, the upconverting rods were incorporated in a polymethylmethacrylate (PMMA) layer on the rear side of a-Si:H solar cell. Under AM1.5 solar irradiation, a facile optical filter was used to scrutinize the effect of upconversion on the cell performance. Compared with a bare cell, the NaYF4:Yb3+/Er3+-based a-Si:H cell exhibited an 25% improved short-circuit current and an appreciable improvement of the near-infrared response of the external quantum efficiency. Moreover, because the size of the nanorods is comparable to the wavelength of visible light, the rods effectively scattered light, thus enhancing the visible light harvesting.

Genome-Wide Association Study Identifies Candidate Genes Related to Seed Oil Composition and Protein Content in Gossypium hirsutum L.

Cotton (Gossypium spp.) is a leading natural fiber crop and an important source of vegetable protein and oil for humans and livestock. To investigate the genetic architecture of seed nutrients in upland cotton, a genome-wide association study (GWAS) was conducted in a panel of 196 germplasm resources under three environments using a CottonSNP80K chip of 77,774 loci. Relatively high genetic diversity (average gene diversity being 0.331) and phenotypic variation (coefficient of variation, CV, exceeding 3.9%) were detected in this panel. Correlation analysis revealed that the well-documented negative association between seed protein (PR) and oil may be to some extent attributable to the negative correlation between oleic acid (OA) and PR. Linkage disequilibrium (LD) was unevenly distributed among chromosomes and subgenomes. It ranged from 0.10-0.20 Mb (Chr19) to 5.65-5.75 Mb (Chr25) among the chromosomes and the range of Dt-subgenomes LD decay distances was smaller than At-subgenomes. This panel was divided into two subpopulations based on the information of 41,815 polymorphic single-nucleotide polymorphism (SNP) markers. The mixed linear model considering both Q-matrix and K-matrix [MLM(Q+K)] was employed to estimate the association between the SNP markers and the seed nutrients, considering the false positives caused by population structure and the kinship. A total of 47 SNP markers and 28 candidate quantitative trait loci (QTLs) regions were found to be significantly associated with seven cottonseed nutrients, including protein, total fatty acid, and five main fatty acid compositions. In addition, the candidate genes in these regions were analyzed, which included three genes, Gh_D12G1161, Gh_D12G1162, and Gh_D12G1165 that were most likely involved in the control of cottonseed protein concentration. These results improved our understanding of the genetic control of cottonseed nutrients and provided potential molecular tools to develop cultivars with high protein and improved fatty acid compositions in cotton breeding programs through marker-assisted selection.