Optimized Nomogram for Nasopharyngeal Carcinoma Prognosis Prediction in Younger Patients (Aged 18-59): Development and Validation.

PURPOSE: To develop a nomogram model for the predicted overall survival (OS) in patients aged 18 to 59 years with nasopharyngeal carcinoma (NPC) and assess the value of the clinical application. METHODS: In total, 1334 registers of NPC patients from 2010 to 2015 were retrieved from the Surveillance, Epidemiology, and End Results database. Univariate and multivariate Cox analysis were used to screen out independent risk factors affecting patients. Cox analysis predicted OS for patients with NPC at 3, 5, and 8 years. Nomogram performance was validated using the concordance index (C-index), receiver operating characteristic, calibration curve, and decision curve analysis (DCA). RESULTS: Age, sex, race, marital, histological type, tumor size, AJCC stage, and radiotherapy were independent risk factors. The C-index of the nomogram was 0.69 [95% confidence interval (CI): 0.68-0.71] for the training set, and the C-index of the AJCC stage was 0.63 (95% CI: 0.62-0.65), both statistically significant (P < .01). The area under the curve for the nomogram at these intervals (0.755, 0.729, and 0.729, respectively) was higher than that of the AJCC stage (0.667, 0.646, and 0.646, respectively), indicating better predictive accuracy. The calibration curves revealed a high degree of agreement between the observation and the prediction. Compared to the American Joint Committee on Cancer (AJCC) stage, DCA showed better clinical utility. CONCLUSION: The nomogram as novel predictor for nasopharyngeal carcinoma patients' survival.

Development and Validation of a Nomogram to Predict the Risk of Tinnitus Severity in Patients With Unilateral Subjective Tinnitus.

Purpose: To develop and validate a nomogram for predicting the risk of tinnitus severity in patients with unilateral subjective tinnitus. Methods: The objective of this study was to establish and validate a nomogram specifically designed for patients with unilateral subjective tinnitus. We collected data on unilateral subjective tinnitus from the Air Force Medical Center, including 146 participants between January 2021 and June 2022. Risk factors for unilateral subjective tinnitus severity were evaluated by least absolute shrinkage and selection operator (LASSO) and binary logistic regression analysis. Internal verification was used to evaluate the performance of the nomogram. The discriminative ability was measured by the consistency index (C-indices) and the area under the curve (AUC) of the receiver operating characteristic (ROC) curves. Results: All included patients were randomized according to a 7:3 ratio into the training cohort (104 patients) and the validation cohort (42 patients). The LASSO regression model identified sex, tinnitus loudness, and hearing loss as candidate variables. Binary logistic regression analysis showed that gender (OR: 0.76; 95% CI: 0.6-0.95; P = 0.021) and tinnitus loudness (OR: 1.37; 95% CI: 1.09-1.72; P = 0.009) were significant predictors of unilateral subjective tinnitus severity, while age, tinnitus matching frequency, and tinnitus duration were not. The significant predictors were included in the nomogram. Hearing loss was included in the nomogram based on prior clinical experience and previous studies. The training and validation cohorts C-indexes were 0.707 (95% CI: 0.607-0.806) and 0.706 (95% CI: 0.548-0.863), respectively. The training and validation cohort's AUC of the ROC curves were 0.692 and 0.705, respectively. Conclusion: We have developed and validated a nomogram based on gender, hearing loss, and tinnitus loudness, which can effectively predict the risk of tinnitus severity in patients with unilateral subjective tinnitus. The nomogram provides personalized prediction results for patients with unilateral subjective tinnitus, which is beneficial for clinical decision-making and treatment plan development.

Two-photon fluorescence imaging of subsurface tissue structures with volume holographic microscopy.

SIGNIFICANCE: Two-photon (2P) fluorescence imaging can provide background-free high-contrast images from the scattering tissues. However, obtaining a multiplane image is not straightforward. We present a two-photon volume holographic imaging (2P-VHI) system for multiplane imaging. AIM: Our goal was to design and implement a 2P-VHI system that can provide the high-contrast optically sectioned images at multiple planes. APPROACH: A 2P-VHI system is presented that incorporates angularly multiplexed volume holographic gratings and a femtosecond laser source for fluorescence excitation for multiplane imaging. A volume hologram with multiplexed gratings provides multifocal observation, whereas nonlinear excitation using a femtosecond laser helps in significantly enhancing both depth resolution and contrast of images. RESULTS: Standard fluorescent beads are used to demonstrate the imaging performance of the 2P-VHI system. Two-depth resolved optical-sectioning images of fluorescently labeled thick mice intestine samples were obtained. In addition, the optical sectioning capability of our system is measured and compared with that of a conventional VHI system. CONCLUSIONS: Results demonstrated that 2P excitation in VHI systems provided the optical sectioning ability that helps in reducing background noise in the images. Integration of nonlinear fluorescence excitation in the VHI provides some unique advantages to the system and has potential to design multidepth optical sectioned spatial-spectral imaging systems.

Metasurface-enhanced optical lever sensitivity for atomic force microscopy.

We proposed the integration of metasurfaces on atomic force microscopy (AFM) cantilevers to improve the optical lever sensitivity. The metasurface positioned at the back of an AFM cantilever enables anomalous reflection of the laser beam and provides a nonlinear relationship between the incidence and reflection angles following the generalized Snell's law. Therefore, the displacement of the reflected laser spot at the photodetector can be amplified. The metasurface was composed of 30 nm thick Au nano-discs with different diameters in an array of 1500 nm × 300 nm super cells. Using the fabricated metasurface mounted on a precise angle dial and a macroscale cantilever as prototypes, the concept of a metasurface-enhanced cantilever was experimentally ascertained. Results proved that the optical lever sensitivity can be easily increased. Finite element analysis showed that integration of the thin metasurface does not have a significant impact on the cantilever's mechanical properties including stiffness and eigenfrequencies. The proposed metasurface-enhanced optical lever sensitivity may have potential applications in improving functional performances of AFM instruments and cantilever-based sensors, such as allowing much smaller imaging forces and boosting the signal-to-noise ratio.

Optical volumetric projection for fast 3D imaging through circularly symmetric pupil engineering.

Monitoring and manipulating neuronal activities with optical microscopy desires a method where light can be focused or projected over a long axial range so that large brain tissues (>100 [Formula: see text] thick) can be simultaneously imaged, and specific brain regions can be optogenetically stimulated without the need for slow optical refocusing. However, the micron-scale resolution required in neuronal imaging yields a depth of field of less than 10 [Formula: see text] in conventional imaging systems. We propose to use a circularly symmetric phase mask to extend the depth of field. A numerical study shows that our method maintains both the peak and the shape of the point spread function vs the axial position better than current methods. Imaging of a 3D bead suspension and sparsely labelled thick brain tissue confirms the feasibility of the system for fast volumetric imaging.

In-line digital holographic imaging in volume holographic microscopy.

A dual-plane in-line digital holographic imaging method incorporating volume holographic microscopy (VHM) is presented to reconstruct objects in a single shot while eliminating zero-order and twin-image diffracted waves. The proposed imaging method is configured such that information from different axial planes is acquired simultaneously using multiplexed volume holographic imaging gratings, as used in VHM, and recorded as in-line holograms where the corresponding reference beams are generated in the fashion of Gabor's in-line holography. Unlike conventional VHM, which can take axial intensity information only at focal depths, the proposed method digitally reconstructs objects at any axial position. Further, we demonstrate the proposed imaging technique's ability to effectively eliminate zero-order and twin images for single-shot three-dimensional object reconstruction.

Wigner analysis of three dimensional pupil with finite lateral aperture.

A three dimensional (3D) pupil is an optical element, most commonly implemented on a volume hologram, that processes the incident optical field on a 3D fashion. Here we analyze the diffraction properties of a 3D pupil with finite lateral aperture in the 4-f imaging system configuration, using the Wigner Distribution Function (WDF) formulation. Since 3D imaging pupil is finite in both lateral and longitudinal directions, the WDF of the volume holographic 4-f imager theoretically predicts distinct Bragg diffraction patterns in phase space. These result in asymmetric profiles of diffracted coherent point spread function between degenerate diffraction and Bragg diffraction, elucidating the fundamental performance of volume holographic imaging. Experimental measurements are also presented, confirming the theoretical predictions.

Enhanced asymmetric transmission due to Fabry-Perot-like cavity.

In this paper, a three layered metamaterial composed of a ring-chain structure sandwiched between two layers of twisted sub-wavelength cut-wire arrays is proposed and investigated. The designed structure is optimized such that asymmetric transmission with an extremely broad bandwidth, sharp rejection stop-band and high transmittance is achieved. The physical mechanism is accounted for that the metallic layers form the Fabry-Perot-like resonance cavity, enhancing the polarization conversion efficiency between two orthogonal linearly polarized waves. To some extent, this approach offers a way to strengthen asymmetric transmission effect.

[Analysis of carbon balance and study on mechanism in anoxic-oxic-settling-anaerobic sludge reduction process].

In order to deeply explore the mechanism of sludge reduction in OSA system, carbon balance was performed in an anoxic-oxic-settling-anaerobic (A + OSA) system and a reference AO system to investigate effects of inserting a sludge holding tank in sludge cycle line on the sludge reduction process. Meanwhile, carbon mass change in each reaction unit was identified in terms of solid, liquid and gas phases. The causes of excess sludge reduction in A + OSA system were deduced. The carbon balance results show that when the hydraulic retention time in the sludge holding tank is 7.14 h, carbon percent in solid phase of the sludge reduction system is nearly 50% higher than that of the reference system, supporting the consequence that sludge reduction rate of 49.98% had been achieved. The insertion of a sludge holding tank in the sludge return circuit can be effective in sludge reduction. Carbon changes in each unit reveal that the amount of carbon consumed for biosynthesis in the anoxic and oxic tanks (main reaction zone) of the sludge reduction system is higher than in that of the reference system. Sludge decay is observed in the sludge holding tank. Furthermore, CH4 released from the sludge holding tank is significantly higher than that from the main reaction zone. The DGGE profiles show that there are hydrolytic-fermentative bacteria in the sludge holding tank related to sludge decay. The excess sludge reduction in the A + OSA system could be a result of the combination of sludge decay in the sludge holding tank and sludge compensatory growth in the main reaction cell.

Resolution enhancement of random adsorbed single-molecule localization based on surface plasmon resonance illumination.

Single-molecule localization (SML) is a powerful tool to overcome the diffraction limit in optical imaging, because the fluorescence emitted by single molecules can be observed with nanometer accuracy when the optical background and associated noise are made sufficiently small. Random adsorbed SML has been successfully demonstrated for superresolution imaging on metal surfaces. To optimize the random adsorbed SML, we developed a new illumination method based on surface plasmon resonance (SPR). The enhancement of the fluorescence signal and the reduction of background noise were achieved simultaneously. A high localization resolution of 15 nm was demonstrated with this new SPR illumination system.

Micro lens fabrication by means of femtosecond two photon photopolymerization.

We report the fabrication of micro lens using an alternative annular scanning mode with continuous variable layer thickness by two-photon polymerization after multi-parameter optimization. Laser scanning mode and scanning pace parameter are optimized to achieve good appearance. As examples of the results, a 2 x 2 micro spherical lens array with diameter of 15 microm and a micro Fresnel lens with diameter of 17 microm are fabricated. Their optical performances are also tested. Compared to the conventional femtosecond two-photon fabrication, this work provides an alternative, effective and cheap processing method for the fabrication of micro optic device that requires arbitrary shape with high surface quality and small scale.