A simple T-shaped plasmonic nanostructure composed of two perpendicular coupled nanorods is proposed to produce strong Fano resonances. By the near-field coupling between the “bright” dipole and ...“dark” quadrupole plasmons of the nanorods, a deep Fano dip is formed in the extinction spectrum, which can be well fitted by the Fano interference model. The effects of the geometry parameters including nanorod length, coupling gap size, and coupling location to the Fano resonances are analyzed in detail, and a very high refractive index sensitivity is achieved by the Fano resonance. Also by adjusting the incident polarization direction, double Fano resonances can be formed by the interferences of the dipole, quadrupole, and hexapole plasmons. The proposed nanorod dimer structure is agile, and a trimer which supports double Fano resonances can be easily formed by introducing a third perpendicular coupled nanorod. The proposed T-shaped nanorod dimer structure may have applications in the fields of biological sensing and plasmon-induced transparency.
A tunable microwave photonic notch filter with ultrahigh radio frequency (RF) rejection ratio is achieved by using a dual-drive Mach-Zender modulator and a microring resonator. In addition, we ...dedicated to clarify the mechanisms of the microwave photonic notch filters based on a microring resonator under both overcoupled and undercoupled states and the performance differences between these two situations are investigated in detail. Furthermore, the experimental results show that the cancellation microwave photonic notch filter with ultrahigh RF rejection ratio can be achieved with both undercoupled and overcoupled microring resonators. Besides, an RF rejection ratio exceeding 50 dB was achieved for a microring resonator with an optical extinction ratio of only 4 dB, where a 46-dB enhancement from optical to RF response is obtained. Also, the bandwidth of the microwave photonic filter can tuned from 0.65 to 2.2 GHz by adjusting the coupling ratio of the ring resonator. Meanwhile, by tuning the wavelength of the optical carrier, the filtering frequency can be tuned and a tuning range of about 25 GHz was achieved. The implementation is much simpler and more economical compared with previous reports and has great potential in monolithic integration of microwave photonic filters on chip.
Questionnaires have been used in the past 2 decades to predict the diagnosis of vertigo and assist clinical decision-making. A questionnaire-based machine learning model is expected to improve the ...efficiency of diagnosis of vestibular disorders. This study aims to develop and validate a questionnaire-based machine learning model that predicts the diagnosis of vertigo. In this multicenter prospective study, patients presenting with vertigo entered a consecutive cohort at their first visit to the ENT and vertigo clinics of 7 tertiary referral centers from August 2019 to March 2021, with a follow-up period of 2 months. All participants completed a diagnostic questionnaire after eligibility screening. Patients who received only 1 final diagnosis by their treating specialists for their primary complaint were included in model development and validation. The data of patients enrolled before February 1, 2021 were used for modeling and cross-validation, while patients enrolled afterward entered external validation. A total of 1693 patients were enrolled, with a response rate of 96.2% (1693/1760). The median age was 51 (IQR 38-61) years, with 991 (58.5%) females; 1041 (61.5%) patients received the final diagnosis during the study period. Among them, 928 (54.8%) patients were included in model development and validation, and 113 (6.7%) patients who enrolled later were used as a test set for external validation. They were classified into 5 diagnostic categories. We compared 9 candidate machine learning methods, and the recalibrated model of light gradient boosting machine achieved the best performance, with an area under the curve of 0.937 (95% CI 0.917-0.962) in cross-validation and 0.954 (95% CI 0.944-0.967) in external validation. The questionnaire-based light gradient boosting machine was able to predict common vestibular disorders and assist decision-making in ENT and vertigo clinics. Further studies with a larger sample size and the participation of neurologists will help assess the generalization and robustness of this machine learning method.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Head and neck squamous cell carcinoma (HNSCC) is highly aggressive with a significant tropism of lymph nodes, which restricts treatment options and negatively impacts patient outcomes. Although ...progress has been made in understanding the molecular mechanisms underlying lymphatic metastasis (LM), these mechanisms remain elusive. ANXA6 is a scaffold protein that participates in tumor pathogenesis and autophagy regulation; however, how ANXA6 affects autophagy and LM in HNSCC cells remains unknown.
RNA sequencing was performed on HNSCC clinical specimens with or without metastasis as well as on The Cancer Genome Atlas dataset to investigate ANXA6 expression and survival. Both in vitro and in vivo studies were performed to investigate the role of ANXA6 in the regulation of LM in HNSCC. The molecular mechanism by which ANXA6 interacts with TRPV2 was examined at the molecular level.
ANXA6 expression was significantly upregulated in HNSCC patients with LM and higher expression was associated with poor prognosis. ANXA6 overexpression promoted the proliferation and mobility of FaDu and SCC15 cells in vitro; however, ANXA6 knockdown retarded LM in HNSCC in vivo. ANXA6 induced autophagy by inhibiting the AKT/mTOR signaling pathway in HNSCC, thereby regulating the metastatic capability of the disease. Furthermore, ANXA6 expression positively correlated with TRPV2 expression both in vitro and in vivo. Lastly, TRPV2 inhibition reversed ANXA6-induced autophagy and LM.
These results indicate that the ANXA6/TRPV2 axis facilitates LM in HNSCC by stimulating autophagy. This study provides a theoretical basis for investigating the ANXA6/TRPV2 axis as a potential target for the treatment of HNSCC, as well as a biomarker for predicting LM.
A stopband and passband switchable microwave photonic filter based on the integrated tunable dual ring coupled Mach-Zehnder interferometer has been demonstrated. By using the optical single sideband ...modulation, the switchable stopband and passband optical responses of the optical filter are one-to-one mapping to the RF spectra. The center frequency and bandwidth of the switchable microwave photonic filter are both reconfigurable. A frequency tuning range of 4-25 GHz is obtained, and the bandwidth tuning ranges of the passband and stopband MPFs are 4.54-9.72 GHz and 3.65-6.35 GHz, respectively. In addition, a RF rejection ratio about 20 dB is achieved. Compared with the switchable MPFs implemented by nonintegrated devices, the proposed switchable MPF provides a simple and low cost method to process radiofrequency signals.
A symmetric dielectric loaded surface plasmon polariton waveguide is proposed and numerically analyzed. The characteristics of the symmetric and asymmetric bound modes, including the effective mode ...indices, propagation lengths, mode sizes and mode shapes at telecom wavelength 1.55 microm are investigated in detail. The simulation results show that the sub-wavelength confinement (about1.45 microm ) and a long propagation (about 820 microm ) can be realized. Although the mode sizes are a bit larger than that of the dielectric loaded surface plasmon polariton waveguide, an order longer propagation length can be achieved. The proposed symmetric dielectric loaded surface plasmon polariton waveguide provides a potential for low loss and high density photonic integration.
Objective To observe the impact of leptin on the activation of group 2 innate lymphocytes (ILC2) in obese adult patients with allergic rhinitis (AR), and investigate its role and significance in the ...pathogenesis of AR. Methods A total of 70 patients with AR were enrolled in the study and divided into obese AR group and non-obese AR group according to body mass index (BMI), and matched with 30 cases in the healthy control group with no difference in age and gender during the same period. Flow cytometry was used to detect the ratio of ILC2 in peripheral blood mononuclear cells (PBMCs) of each group, real-time quantitative PCR to detect the expression of leptin mRNA, and ELISA to detect the serum leptin. The correlation between leptin and ILC2 was analyzed, and the changes in the ratio of ILC2 and relevant immune indexes in PBMCs of the AR group before and after the intervention of recombinant leptin were observed. Results Compared with healthy control group, the expressions of leptin and ILC2 of the AR group in
Understanding of the fundamental photoresponse of carbon nanotubes has broad implications for various photonic and optoelectronic devices. Here, Z-scan and pump-probe spectroscopy performed across ...600-2400 nm were combined to give a broadband 'degenerate' mapping of the nonlinear absorption properties of single-wall carbon nanotubes (SWNTs). In contrast to the views obtained from non-degenerate techniques, sizable saturable absorption is observed from the visible to the near-infrared range, including the spectral regions between semiconducting excitonic peaks and metallic tube transitions. In addition, the broadband mapping unambiguously reveals a photobleaching to photoinduced absorption transition feature within the first semiconducting excitonic band ∼2100 nm, quantitatively marking the long-wavelength cut-off for saturable absorption of the SWNTs investigated. Our findings present a much clearer physical picture of SWNTs' nonlinear absorption characteristics, and help provide updated design guidelines for SWNT based nonlinear optical devices.
A narrow band waveguide Fabry-Perot filter at 1550 nm, which is composed of two polymer waveguide Bragg gratings as reflectors, is presented. By using conventional lithography, a low-loss polymer ...channel waveguide was fabricated, and the submicron Bragg grating structure was transferred onto the waveguide surface using a nanoimprinting technique. The transmission spectrum of the device was measured, and the results show that there is a very narrow transmission peak, with a 3 dB bandwidth of 0.011 nm in the 0.38 nm rejection band of the waveguide Bragg grating. A quality factor of Q ≈ 1.41 × 105 is achieved. The insertion loss and the extinction ratio of the Fabry-Perot filter are about −12.5 dB and 17 dB, respectively. In addition, the measured transmission spectrum is in excellent accordance with the numerical simulation.
A TM-mode-pass polarization rotator and power divider with an arbitrary beam-splitting ratio constructed by an adiabatic taper, a spatial mode order convertor and a multi-mode interferometer (MMI) is ...proposed on the silicon-on insulator (SOI) platform. Both arbitrary power splitting and polarization selection-rotation can be realized in this single device. The measurements show that a continuously adjustable beam-splitting ratio from 1:99 to 99:1 within a 33.2 mW power consumption from 1520-1580 nm has been realized for the proposed device.
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