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BACKGROUND: The long non-coding RNA (lncRNA) LINC00969 is involved in human disease progression, and n6-methyladenosine (m6A) modification of lncRNAs in cancer has been proven to be a key regulatory mechanism. However, our understanding of its effects and mechanisms of action in papillary thyroid carcinoma (PTC) remains limited. OBJECTIVES: This study aimed to elucidate the role of methyltransferase-like 3 (METTL3)-induced m6A modification of LINC00969 in PTC tumorigenesis. MATERIAL AND METHODS: Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to analyze LINC00969 and METTL3 mRNA levels in PTC. The regulation of LINC00969 by METTL3 was confirmed using cell function experiments, molecular biology assays and bioinformatics analysis. LINC00969 stabilization analysis was performed to verify the regulatory roles of METTL3 and LINC00969. RESULTS: LINC00969 expression was downregulated in PTC tissues. Increased LINC00969 expression inhibited the invasion, growth and migration of PTC cells. METTL3 downregulation in PTC mediated the m6A modification of LINC00969, increasing its stability. Furthermore, METTL3 levels were downregulated in PTC, and its silencing partially reversed the inhibitory effect of LINC00969 overexpression on PTC cell malignancy. CONCLUSIONS: LINC00969 overexpression inhibits PTC cell malignancy via METTL3-mediated m6A modification. These findings suggest that METTL3-m6A-LINC00969 is a promising therapeutic target for PTC.

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BACKGROUND: Long non-coding RNA (lncRNA) LINC01125 is an anti-tumor factor in a variety of tumors, and regulates cancer cell function. However, its function and mechanism of N6-methyladenosine (m6A) modification in papillary thyroid cancer (PTC) tumorigenesis remain unclear. AIMS: This study aimed to reveal the function and m6A modification of LINC01125 in PTC tumorigenesis. METHODS: The LINC01125 and methyltransferase-like 3 (METTL3) levels in PTC cells and tissues was assessed by qRT-PCR. The binding relationship among LINC01125 and METTL3 was determined by MeRIP, Pearson, bioinformatics, and RNA stabilization analysis. Transwell assays were performed to confirm the changes of PTC cell migration and invasion. Cell proliferation was revealed by CCK-8 as well as colony formation assays. RESULTS: Low expression of LINC01125 and METTL3 was identified in PTC. LINC01125 was a downstream target of METTL3-mediated m6A modification and was stably upregulated via METTL3. Cell invasion, migration, viability, and colony formation levels were decreased when LINC01125 or METTL3 was upregulated. Inhibition of LINC01125 had the opposite impact, promoting cell proliferation and metastasis, and reversing METTL3 overexpression-resulted cell malignancy suppression. CONCLUSIONS: Overall, this study proved that the m6A modification of LINC01125 was mediated by METTL3 and LINC01125 inhibited cell invasion, migration and proliferation, thereby suppressing the development of PTC. This points to the LINC01125-m6A-METTL3 axis as a possible prospective target for future treatment of PTC.

Asunto(s)

ARN Largo no Codificante , Neoplasias de la Tiroides , Humanos , ARN Largo no Codificante/genética , Cáncer Papilar Tiroideo/genética , Metiltransferasas/genética , Metiltransferasas/metabolismo , Línea Celular Tumoral , Neoplasias de la Tiroides/genética , Carcinogénesis

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We report a thin-film circular polarizer consisting of three metal-grid layers to be used with a photoconductive antenna (PCA) to generate terahertz (THz) circularly polarized (CP) radiation. The polarizer has a high transmission with a measured 3 dB axial-ratio bandwidth of 54.7% from 0.57 to 1 THz. We further developed a generalized scattering matrix approach to provide insight into the underlying physical mechanism of the polarizer. We revealed that the Fabry-Pérot-like multi-reflection among gratings enables the high-efficiency polarization conversion. The successful realization of the CP PCA can find widespread application, such as THz circular dichroism spectroscopy, THz Mueller imaging, and ultrahigh-speed THz wireless communications.

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A Fourier lens can perform the Fourier transform of an incident wavefront at the focal plane. This paper reports a metasurface-based Fourier lens fed by compact plasmonic optical antennas for wide-angle beam steering. The metasurface, composed of six elements with different configurations covering the 2π phase range, features a large field-of-view (FOV) of ±50°. A novel plasmonic optical antenna for broadside radiation is then designed as the feed source of the metasurface. The proposed antenna has ultra-compact size of 0.77λ × 1.4λ, and achieves a high directivity of 9.6 dB and radiation efficiency of over 80% at the wavelength of 1550 nm. Full-wave simulations are carried out to evaluate the performances of the designed metasurface-assisted beam steering device. The results show that this device can achieve a maximum directivity of 21.5 dB at broadside radiation. Compared to conventional Yagi-Uda antenna feed, a directivity enhancement of about 2.7 dB can be obtained, exhibiting a great superiority of the proposed feed antenna. In addition, a large beam steering range of ±50° can be achieved with an acceptable gain drop of 2.83 dB. With the advantages of wide beam steering range, good radiation characteristics, small footprint, and ease of integration, the proposed metasurface-assisted beam steering device would be a promising candidate for integrated photonic applications, including wireless optical communications, light detection and ranging, and augmented reality.

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Mueller matrix polarimetry (MMP) has been demonstrated and recognized as an effective approach to attaining imaging enhancement as well as revealing polarization properties of an imaged sample. Generally, a minimum of 16 combinations of intensity-only measurements involving both linear and circular polarizations are required to completely and accurately determine the 4 × 4 Mueller matrix (MM) and comprehensively describe the polarization properties of the sample. However, broadband circular polarizations (CP) are rather difficult to obtain for design and fabrication limitations in the terahertz region, which poses a challenge to the acquisition of the 4 × 4 MM. In this circumstance, the 3 × 3 MM degradation using only linear polarizations (LP) is preferred and sufficient for characterization of non-depolarizing samples. In this paper, a multi-spectral 3 × 3 MMP system based on the THz time-domain spectroscopy (THz-TDS) is established from 0.1 to 1 THz. The system demonstrated is capable of fulfilling the accurate determination of the 3 × 3 MM. The Mueller matrix polar decomposition (MMPD), modified to be compatible with the MM degradation, is employed to explore the fine details and properties of the sample. By signal post-processing techniques, the MM elements in the time domain are retrieved, and the time dimension reflecting the depth information facilitates the 3D reconstruction of the sample. This work provides a prototype for 3D imaging of biological samples at higher frequencies in the future.

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BACKGROUND: Parathyroidectomy (PTX) has been demonstrated as an effective treatment for patients with secondary hyperparathyroidism (SHPT) of renal origin. However, severe hypocalcemia, called hungry bone syndrome (HBS), is a common complication following PTX in these patients and can lead to poor clinical outcomes, even death. Therefore, exploring risk factors for HBS and establishing a prediction nomogram allow intensive monitoring and prompt treating this postoperative complication, which is the main purpose of this study. METHODS: From October 2016 to October 2018, PTX with autotransplantation (PTX + AT) procedures were performed in 131 patients with SHPT of renal origin by a surgeon and his team in the Thyroid and Parathyroid Surgery Center, West China Hospital, Sichuan University, China. After applying the inclusion and exclusion criteria, a total of 114 patients were enrolled for analyses in this study. Comprehensive data including preoperative, intraoperative, and postoperative variables were prospectively collected and retrospectively analyzed. The univariate and multivariate logistic regression analyses with internal validation by bootstrapping were used to confirm independent risk factors for postoperative HBS. The nomogram was developed based on the statistical analysis results. Receiver operator characteristic (ROC) curves were drawn to compare the prediction performance among different predictors. RESULTS: The occurrence of postoperative HBS was 76.3% (87 out of 114 patients) in this study. Univariate analysis showed that preoperative intact parathyroid hormone (iPTH), serum alkaline phosphatase, bone-specific alkaline phosphatase (bone-ALP) were significantly higher in HBS group than those in non-HBS group, while preoperative corrected serum calcium and albumin were significantly lower in HBS group than those in non-HBS group. Total weight of resected parathyroid glands was significantly heavier in HBS group versus non-HBS group. Multivariate logistic regression analysis with internal validation by bootstrapping demonstrated preoperative iPTH, bone-ALP, preoperative corrected serum calcium, and total weight of resected parathyroid glands were independently associated with postoperative HBS. The nomogram including the abovementioned four independent predictors was constructed and showed better prediction performance than the other four predictors in terms of postoperative HBS. CONCLUSIONS: On the basis of this study, we found higher preoperative iPTH level, higher bone-ALP level, heavier total weight of resected parathyroid glands, and lower preoperative corrected serum calcium level were independent predictors of postoperative HBS in patients with SHPT of renal origin. The nomogram can expediently, accurately, and objectively predict the risk of postoperative HBS in individual patient with SHPT of renal origin.

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Hiperparatiroidismo Secundario/cirugía , Hipocalcemia/epidemiología , Nomogramas , Paratiroidectomía/efectos adversos , Complicaciones Posoperatorias/epidemiología , Trasplante Autólogo/efectos adversos , Adulto , Calcio/sangre , Femenino , Humanos , Hiperparatiroidismo Secundario/etiología , Hipocalcemia/sangre , Hipocalcemia/diagnóstico , Hipocalcemia/etiología , Masculino , Persona de Mediana Edad , Glándulas Paratiroides/trasplante , Hormona Paratiroidea/sangre , Paratiroidectomía/métodos , Complicaciones Posoperatorias/sangre , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/etiología , Periodo Preoperatorio , Curva ROC , Insuficiencia Renal Crónica/complicaciones , Estudios Retrospectivos , Factores de Riesgo , Trasplante Autólogo/métodos , Resultado del Tratamiento

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An in-line fiber optic Fabry-Perot (FP) sensor for high-temperature vibration measurement is proposed and experimentally demonstrated in this paper. We constructed an FP cavity and a mass on single-mode fibers (SMFs) by fusion, and together they were inserted into a hollow silica glass tube (HST) to form a vibration sensor. The radial dimension of the sensor was less than 500 µm. With its all-silica structure, the sensor has the prospect of measuring vibration in high-temperature environments. In our test, the sensor had a resonance frequency of 165 Hz. The voltage sensitivity of the sensor system was about 11.57 mV/g and the nonlinearity was about 2.06%. The sensor could work normally when the temperature was below 500 °C, and the drift of the phase offset point with temperature was 0.84 pm/°C.

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Optical phased arrays have been demonstrated to enable a variety of applications ranging from high-speed on-chip communications to vertical surface emitting lasers. Despite the prosperities of the researches on optical phased arrays, presently, the reported designs of optical phased arrays are based on silicon photonics while plasmonic-based optical phased arrays have not been demonstrated yet. In this paper, a passive plasmonic optical phased array is proposed and experimentally demonstrated. The beam of the proposed plasmonic optical phased array is steerable in the far-field area and a high directivity can be achieved. In addition, radio frequency phased array theory is demonstrated to be applicable to the description of the coupling conditions of the delocalized surface plasmons in optical phased arrays and thus the gap between the phased arrays at two distinctly different wavelengths can be bridged. The potential applications of the proposed plasmonic phased arrays include on-chip optical wireless nanolinks, optical interconnections and integrated plasmonic lasers.

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The ability to manipulate the propagation properties of electromagnetic waves, e.g., divergence, focusing, holography or deflection, is very significant in terahertz applications. Metasurfaces with flat structures are attractive for achieving such manipulations in terahertz band, as they feature low profile, lightweight, and ease of design and installation. Several types of terahertz reflective or transmitting metasurfaces with focusing function have been implemented recently, but none of them can provide scanning ability with controllable focus. Here, a flat reflective metasurface featuring controllable focal shift is proposed and experimentally demonstrated. Furthermore, the principle of designing a focus scanning reflective metasurface is presented and the focusing characteristics are discussed, including focus scanning along a line parallel or orthogonal to the metasurface with a large bandwidth. These interesting properties indicate that this flat reflective metasurface could play a key role in many terahertz imaging and detection systems.

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There is no known simple rule that assures the existence of interface states in photonic crystals (PCs). We show here that one can control the existence or absence of interface states in 1D PCs through engineering the bulk geometrical phase such that interface states can be guaranteed in some or all photonic bandgaps. We verify experimentally the interface state design paradigm in 1D multilayered PCs fabricated by electron beam vapor deposition. We obtain the geometrical phases by measuring the reflection phases at the bandgaps of the PCs and achieve good agreement with the theory. Our approach could provide a platform for generating a PC interface state for various applications.

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Terahertz (THz) metasurfaces have been explored recently due to their properties such as low material loss and ease of fabrication compared to three-dimensional (3D) metamaterials. Although the dispersion properties of the reflection/transmission-type THz metasurface were observed in some published literature, the method to control them at will has been scarcely reported to the best of our knowledge. In this context, flexible dispersion control of the THz metasurface will lead to great opportunities toward unprecedented THz devices. As an example, a THz metasurface with controllable dispersion characteristics has been successfully demonstrated in this article, and the incident waves at different frequencies from a source in front of the metasurface can be projected into different desired anomalous angular positions. Furthermore, this work provides a potential approach to other kinds of novel THz devices that need controllable metasurface dispersion properties.

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Superbroadband emission from 1.0 to 1.7 µm wavelength was observed in thulium-bismuth (Tm-Bi) codoped sodium-germanium-gallate (NGG) glasses under 793 nm excitation. Efficient energy transfer process from Bi to Tm ions, with value as high as 67.7%, was achieved which is beneficial in achieving flat broadband lineshape. The large stimulated emission cross-section and measured lifetime confirm the potentials of Tm-Bi codopants as luminescence sources for superbroadband near-infrared (NIR) optical amplifiers and tunable lasers. Planar optical waveguides were fabricated successfully in the codoped NGG glasses using K(+)-Na(+) ion-exchange process.

Asunto(s)

Vidrio/química , Rayos Láser , Iluminación/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo , Rayos Infrarrojos

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We have fabricated and characterized optically Nd3+-doped phosphate [Li2O-CaO-BaO-Al2O3-La2O3-P2O5 (LCBALP)] glasses for drawing single-mode glass fiber. The 4F3/2→4I13/2 transition emission from the Nd3+ is at the 1.327 µm wavelength with a full width at half-maximum of 43 nm, and the spontaneous transition probability and quantum efficiency are calculated to be 1836 s-1 and 52%, respectively. The maximum stimulated emission cross sections for 4F3/2→4I11/2 and 4F3/2→4I13/2 transitions are derived to be 1.82×10(-20) cm2 and 6.97×10(-21) cm2, respectively, and the theoretical gain coefficient at the 1.327 µm wavelength is evaluated to be 0.182 dB/cm when the fractional factor of the excited neodymium ions equals 0.6, which indicates that Nd3+-doped LCBALP phosphate glasses are potential candidates in developing O-band optical fiber amplifiers.