Development and validation of a radiopathomic model for predicting pathologic complete response to neoadjuvant chemotherapy in breast cancer patients.

BACKGROUND: Neoadjuvant chemotherapy (NAC) has become the standard therapeutic option for early high-risk and locally advanced breast cancer. However, response rates to NAC vary between patients, causing delays in treatment and affecting the prognosis for patients who do not sensitive to NAC. MATERIALS AND METHODS: In total, 211 breast cancer patients who completed NAC (training set: 155, validation set: 56) were retrospectively enrolled. we developed a deep learning radiopathomics model(DLRPM) by Support Vector Machine (SVM) method based on clinicopathological features, radiomics features, and pathomics features. Furthermore, we comprehensively validated the DLRPM and compared it with three single-scale signatures. RESULTS: DLRPM had favourable performance for the prediction of pathological complete response (pCR) in the training set (AUC 0.933[95% CI 0.895-0.971]), and in the validation set (AUC 0.927 [95% CI 0.858-0.996]). In the validation set, DLRPM also significantly outperformed the radiomics signature (AUC 0.821[0.700-0.942]), pathomics signature (AUC 0.766[0.629-0.903]), and deep learning pathomics signature (AUC 0.804[0.683-0.925]) (all p < 0.05). The calibration curves and decision curve analysis also indicated the clinical effectiveness of the DLRPM. CONCLUSIONS: DLRPM can help clinicians accurately predict the efficacy of NAC before treatment, highlighting the potential of artificial intelligence to improve the personalized treatment of breast cancer patients.

Ultra-wideband RCS reduction based on coupling effects between beam diffuse and absorptive structures.

A hybrid design method for broadband radar cross section (RCS) reduction is proposed and successfully demonstrated based on the coupling effects between diffuse and absorptive structures. The reflection energy is distributed into more directions away from the source direction by the one-bit diffuse coding metasurface (CM). The two-layer resistive frequency selective surface (RFSS) is employed in the one-bit CM structure, reducing the amplitude of the co- and cross-polarized reflected waves under circularly polarized wave incidence by converting it into ohmic loss. In addition, the bandwidth of RCS reduction is further broadened through the coupling effects between the metallic patterns and the two-layer RFSS. The coupling effect shows that the absorption rate of the composite structure is significantly improved compared to the only RFSS structure. A lightweight CM loaded with RFSS (the area density is 597 g/m2) was fabricated, analyzed, simulated, and measured. The results show that the proposed mechanism can effectively break the bandwidth constraints of traditional diffusion and absorption methods. Furthermore, the proposed mechanism significantly expands the bandwidth of RCS reduction. The proposed metasurface can achieve a 10 dB RCS reduction in an ultra-wideband from 7.3 to 44.2 GHz with about 143.3% fractional bandwidth. Moreover, the metasurface also has good performances under wide-angle oblique incidences. Under the condition of maintaining lightweight, the design provides an idea for broadening the frequency band.

Absorptive frequency selective surface with two alternately switchable transmission/reflection bands.

The traditional frequency selective surface (FSS) needs further improvement with the development of stealth technology, and the design of multifunctional FSSs is essential. In this letter, an active absorptive FSS (AFSS) has been designed based on the absorption structure of the spoof surface plasmon polariton (SSPP) and the switching activity of the active FSS. The active FSS embedded with PIN diodes realizes the shift of two transmission/reflection frequency bands by controlling the bias voltage of the feed network, which switches from one band-pass response (at around 3.06 GHz) to the other (at around 4.34 GHz). And when one of the transmission windows switches to the other, the original transmission window closes. The upper plasmonic structure achieves a continuous and efficient absorption band from 6.31 to 8.34 GHz. A sample was also fabricated and carried out to verify the numerical simulation, and the experimental and simulation results are consistent. This work provides new ideas for the design of active AFSS and promotes its application in common aperture radome, antenna isolation, and electromagnetic shielding.

Circular dichroism assisted metadevice for efficient transmission and broadband absorption.

Owing to the intriguing capability of manipulating electromagnetic (EM) properties, the metasurface has aroused great attention of researchers and promoted its applications in EM invisibility. However, there are strong demands to provide an efficient transparent window for signals transmitting in EM invisibility devices. Here, we propose a scheme of a circular dichroism assisted metadevice to provide efficient transmission and broadband absorption in microwave frequencies. By employing chiral meta-atoms to introduce a strong asymmetric response for circularly polarized waves, a chiral metadevice for spin-selective absorption with an efficient transmission is presented. Then, we couple four chiral atoms into a polarization-insensitive atom pair, thus the achiral metadevice presents an identical high-efficiency absorption for both the x- and y-polarized wave. Here, both the chiral and achiral metadevices are realized by loading the metasurface-based absorber on a bandpass frequency selective surface. A proof-of-prototype is fabricated to verify the achiral design. The simulated and experimental results have demonstrated wideband, high-efficiency, polarization-insensitive absorption and high in-band transmission. Interestingly, the proposed paradigm can not only provide the potential for chirality-enhanced absorber design but also may trigger applications in spin-dependent systems, stealth antenna systems, and EM camouflage devices.

Full-space-manipulated multifunctional coding metasurface based on "Fabry-Pérot-like" cavity.

Multifunctional coding metasurfaces (CMs) have attracted extensive attention due to their ability to realize the multifunctional integration in optical devices. However, the researches on multifunctional CM mainly focus on dual functionality in reflected or transmitted space. Here, based on "Fabry-Pérot-like" cavity, we propose a novel multifunctional CM to simultaneously control different polarized light in full-space. It is revealed that the designed CM possesses asymmetric transmission characteristic, which can simultaneously achieve three different functionalities by changing the polarization state and the propagation direction of incident light. As a proof of concept, a single CM is designed to simultaneously realize the functionalities of beam splitting, diffusion scattering for co-polarized reflection and beam focusing for cross-polarized transmission. The simulated results are consistent with the experimental results, which demonstrates the feasibility of the design. This finding provides an effective approach to design multifunctional devices with miniaturization and high integration, which can also be used to achieve desired functionalities in other frequency domains.

Transparent broadband metamaterial absorber enhanced by water-substrate incorporation.

In this paper, a transparent metamaterial absorber (MA) loaded with water substrate is presented, which can simultaneously achieve enhanced broadband microwave absorption and tunable infrared radiation. As a proof, the indium tin oxide (ITO) films are first introduced here as a frequency selective surface (FSS) on the top layer and reflective backplane on the ground layer. Next the distilled water combined with the polymethyl methacrylate (PMMA) substrate is employed as a hybrid substrate in the middle. Simulation and experimental measurements show that the transparent water-substrate MA can achieve broadband microwave absorption with efficiency over 90% in the frequency band of 6.4-23.7GHz, and the proposed hybrid substrate has almost no influence on its original transmittance. Moreover, owing to the available water circulation system, the infrared radiation of the proposed MA is also demonstrated to be controlled by the temperature of the injected water. Based on its multifunction and high performance, it is expected that the proposed design may find potential applications, such as glass window of stealth equipment, electromagnetic compatible buildings/facilities, etc.

Transparent and broadband absorption-diffusion-integrated low-scattering metamaterial by standing-up lattice.

In this paper, a transparent absorption-diffusion-integrated metamaterial (ADMM) based on standing-up lattice structure is proposed which takes full advantage of electromagnetic absorption and destructive interference simultaneously for the suppression of broadband backward scattering within a wide angular domain, especially for the lower-frequency scattering. The proposed ADMM is constituted by two kinds of rhombic and squared ITO lattices arranged in a pseudorandom distribution and then backed with ITO film. Calculation, simulation, and experimental measurement show that the proposed ADMM can achieve low scattering with normalized reflection less than 0.1 in the frequency band of 6.1-21.0GHz. In addition, owing to the standing-up lattice structure, the averaged optical transmittance of our ADMM reaches the optimal value of around 82.1% in the visible wavelength range of 380-780nm, promising an excellent optical transparency. The proposed comprehensive scheme provides an effective way to achieve broadband scattering suppression and high compatibility with optical transparency, enabling a wide range of applications in the window glass of stealth armament, electromagnetic compatibility facility and photovoltaic solar device.

Fast optimization method of designing a wideband metasurface without using the Pancharatnam-Berry phase.

Arbitrary control of electromagnetic waves remains a significant challenge although it promises many important applications. Here, we proposed a fast optimization method of designing a wideband metasurface without using the Pancharatnam-Berry (PB) phase, of which the elements are non-absorptive and capable of predicting the wideband and smooth phase-shift. In our design method, the metasurface is composed of low-Q-factor resonant elements without using the PB phase, and is optimized by the genetic algorithm and nonlinear fitting method, having the advantages that the far field scattering patterns can be quickly synthesized by the hybrid array patterns. To validate the design method, a wideband low radar cross section metasurface is demonstrated, showing good feasibility and performance of wideband RCS reduction. This work reveals an opportunity arising from a metasurface in effective manipulation of microwave and flexible fast optimal design method.

High-efficiency polarization conversion based on spatial dispersion modulation of spoof surface plasmon polaritons.

In this paper, we propose to achieve high-efficiency polarization conversion based on spatial dispersion modulation of spoof surface plasmon polaritons (SSPP). Different k is firstly designed in the two transverse directions by aligning an SSPP-supporting fishbone structure in y direction while maintaining free space in x direction. The orthogonal phase difference is introduced by larger k of SSPP waves for y-polarized component of incident waves. Meanwhile, to achieve high efficiency, gradient k in z-direction is designed so that the y-polarized component of incident waves can be coupled perfectly as SSPP waves. By rotating the fishbone structure with respect to the polarization direction of incident waves, different polarization states for transmitted waves can be realized. As an example, a polarization converter prototype with the central working frequency f = 8GHz was designed, fabricated, and measured. Both the simulation and experiment demonstrate the high-efficiency linear-to-circular (LTC) polarization conversion in 6.9-9.6GHz.

k-dispersion engineering of spoof surface plasmon polaritons for beam steering.

In this paper, we propose to achieve beam steering by k-dispersion engineering of spoof surface plasmon polaritons (spoof SPP) at microwave frequencies. The planar plasmonic metamaterials (PPMs) are employed to couple and guide spoof SPP. High-efficiency transmission based on spoof SPP coupling is realized via matching the wave-vectors of the spoof SPP and the space wave. The transmission phase can be modulated by k-dispersion engineering of the spoof SPP with great freedom. Due to the independent phase shift produced by the spoof SPP on the PPMs, the phase gradient achieved by using the PPMs as the sub-unit cells can be altered by changing the repetition period of the sub-unit cells. Two phase gradient materials (PGMs) are achieved by using nine different PPMs as the sub-unit cells with the repetition period q = 4mm and 4.5mm. Both the simulated and measured results demonstrated the excellent performances of the PGMs on high efficiency, wideband, tunable beam steering.

Deep Learning Radiomics Nomogram Based on Multiphase Computed Tomography for Predicting Axillary Lymph Node Metastasis in Breast Cancer.

PURPOSE: This study aims to develop and validate a deep learning radiomics nomogram (DLRN) for prediction of axillary lymph node metastasis (ALNM) in breast cancer patients. MATERIALS AND METHODS: We retrospectively enrolled 196 patients with non-specific invasive breast cancer confirmed by pathology, radiomics and deep learning features were extracted from unenhanced and biphasic (arterial and venous phase) contrast-enhanced CT, and the non-linear support vector machine was used to construct the radiomics signature and the deep learning signature, respectively. Next, a DLRN was developed with independent predictors and evaluated the performance of models in terms of discrimination and clinical utility. RESULTS: Multivariate logistic regression analysis showed that the radiomics signature, deep learning signature, and clinical n stage were independent predictors. The DLRN accurately predicted ALNM and yielded an area under the receiver operator characteristic curve of 0.893 (95% confidence interval, 0.814-0.972) in the validation set, with good calibration. Decision curve analysis confirmed that the DLRN had higher clinical utility than other predictors. CONCLUSIONS: The DLRN had good predictive value for ALNM in breast cancer patients and provide valuable information for individual treatment.

Risk factors and prevention of liver cancer: A bibliometric and visual analysis.

Liver cancer has become an important public health problem. In this study, bibliometrics and visual analysis were performed on the literature related to the risk factors and prevention of liver cancer, in order to understand the latest research progress of the risk factors and prevention of liver cancer. The Web of Science database was used as a retrieval platform to retrieve the published research results from 2012 to 2023. CiteSpace and VOSviewer were utilized for bibliometrics and visual analysis. A total of 2388 articles were screened according to exclusion criteria. Between 2012 and 2018, the number of articles published fluctuated. From 2018 to 2023, the number of published documents showed a steady upward trend. The 3 journals with the most publications are World Journal of Gastroenterology, PLOS ONE, and Hepatology. The United States and China are the countries with the most publications, while Harvard University, the National Institutes of Health and the University of Texas System are the 3 institutions with the most publications. Keywords such as hepatitis B virus, hepatitis C virus, alcohol, obesity, recrudescence rate, global burden are hot words in the field of liver cancer risk factors and prevention. The current research mainly focuses on the influence of environmental factors, behavioral lifestyle and biological factors on liver cancer, as well as the primary and secondary prevention of liver cancer, but there are still many undetermined factors to be explored.

Development and validation of radiomics machine learning model based on contrast-enhanced computed tomography to predict axillary lymph node metastasis in breast cancer.

Preoperative identification of axillary lymph node metastasis can play an important role in treatment selection strategy and prognosis evaluation. This study aimed to establish a clinical nomogram based on lymph node images to predict lymph node metastasis in breast cancer patients. A total of 193 patients with non-specific invasive breast cancer were divided into training (n = 135) and validation set (n = 58). Radiomics features were extracted from lymph node images instead of tumor region, and the least absolute shrinkage and selection operator logistic algorithm was used to select the extracted features and generate radiomics score. Then, the important clinical factors and radiomics score were integrated into a nomogram. A receiver operating characteristic curve was used to evaluate the nomogram, and the clinical benefit of using the nomogram was evaluated by decision curve analysis. We found that clinical N stage and radiomics score were independent clinical predictors. Besides, the nomogram accurately predicted axillary lymph node metastasis, yielding an area under the receiver operating characteristic curve of 0.95 (95% confidence interval 0.93-0.98) in the validation set, indicating satisfactory calibration. Decision curve analysis confirmed that the nomogram had higher clinical utility than clinical N stage or radiomics score alone. Overall, the nomogram based on radiomics features and clinical factors can help radiologists to predict axillary lymph node metastasis preoperatively and provide valuable information for individual treatment.

Tailoring the Excited and Cutoff States of Spoof Surface Plasmon Polaritons for Full-Space Quadruple Functionalities.

Integrating diversified functionalities within a single aperture is crucial for microwave and optics-integrated devices. To date, research on this issue suffers from restricted bifunctionality, inadequate efficiency, and the limitation of extending to manipulate full-space wave. Here, we propose a general paradigm to achieve full-space multifunctional integration via tailoring the excited and cutoff states of spoof surface plasmon polaritons (SSPPs). A plasmonic meta-atom consisting of judiciously arranged metallic strips is used to excite and cut off the SSPP mode with uniaxially anisotropic characteristics. By shaping the topological structure of the meta-atom, the transmission and reflection phases are arbitrarily controlled at each pixel. Accordingly, the cross-placed meta-atom arrays can be designed to achieve independent phase profiles for x-/y-polarized transmission/reflection waves through dispersion engineering. A metamaterial with quadruple functionalities of backward beams scattering/anomalous reflection and electromagnetic transmission focusing/vortex is designed and fabricated as a proof-of-principle to reveal flexible manipulation. Both simulation and experimental verification are carried out in microwave frequency to demonstrate the feasibility.

Achieving circular-to-linear polarization conversion and beam deflection simultaneously using anisotropic coding metasurfaces.

An anisotropic coding metasurface (CM) is proposed for achieving circular-to-linear polarization conversion and beam deflection. Different phase coding consequences were independently achieved for two orthogonal linear polarized (LP) waves. Thus by elaborately designing coding sequences of the metasurfaces, different functions can be achieved, respectively for waves polarized along two orthogonal directions. More importantly, for circularly polarized (CP) wave, anisotropic CM can achieve circular-to-linear polarization conversion and beam deflection simultaneously. As a proof, a 1-bit anisotropic CM with 0101…/0101… and 0000…/1111… coding sequences respectively for two orthogonal LP waves was designed. The simulation results indicated that the incident CP wave is deflected into two x-polarized waves in x-o-z plane and two y-polarized waves in y-o-z plane. Both the simulation and experimental results verify the circular-to-linear polarization conversion performance of the anisotropic coding metasurfaces. The proposed anisotropic coding metasurfaces have the potential for the applications of multifunctional devices.

Thermally Tunable Ultra-wideband Metamaterial Absorbers based on Three-dimensional Water-substrate construction.

Distilled water has frequency dispersive characteristic and high value of imaginary part in permittivity, which can be seen as a good candidate of broadband metamaterial absorbers(MAs) in microwave. Here, an interesting idea based on the combination of water-substrate and metallic metamaterial in the three-dimensional construction is proposed, which can achieve outstanding broadband absorption. As a proof, the distilled water is filled into the dielectric reservoir as ultra-thin water-substrate, and then the water-substrates are arranged on the metal backplane periodically as three-dimensional water-substrate array(TWA). Simulation shows that the TWA achieves broadband absorption with the efficiency more than 90% from 8.3 to 21.0 GHz. Then, the trigonal metallic fishbone structure is introduced here between the water-substrate and the dielectric reservoir periodically as three-dimensional water-substrate metamaterial absorber(TWMA). The proposed TWMA could achieve ultra-broadband absorption from 2.6 to 16.8 GHz, which has increase by 64.8% in relative absorption bandwidth. Meanwhile, due to the participation of distilled water, the thermally tunable property also deserves to be discussed here. In view of the outstanding performance, it is worth to expect a wide range of applications to emerge inspired from the proposed construction.

High-efficiency tri-band quasi-continuous phase gradient metamaterials based on spoof surface plasmon polaritons.

A high-efficiency tri-band quasi-continuous phase gradient metamaterial is designed and demonstrated based on spoof surface plasmon polaritons (SSPPs). High-efficiency polarizaiton conversion transmission is firstly achieved via tailoring phase differece between the transmisive SSPP and the space wave in orthogonal directions. As an example, a tri-band circular-to-circular (CTC) polarization conversion metamateiral (PCM) was designed by a nonlinearly dispersive phase difference. Using such PCM unit cell, a tri-band quasi-continuous phase gradient metamaterial (PGM) was then realized by virtue of the Pancharatnam-Berry phase. The distribution of the cross-polarization transmission phase along the x-direction is continuous except for two infinitely small intervals near the phases 0° and 360°, and thus the phase gradient has definition at any point along the x-direction. The simulated normalized polarization conversion transmission spectrums together with the electric field distributions for circularly polarized wave and linearly polarized wave demonstrated the high-efficiency anomalous refraction of the quasi-continuous PGM. The experimental verification for the linearly polarized incidence was also provided.

Reconfigurable all-dielectric metamaterial frequency selective surface based on high-permittivity ceramics.

Based on effective medium theory and dielectric resonator theory, we propose the design of reconfigurable all-dielectric metamaterial frequency selective surfaces (FSSs) using high-permittivity ceramics. The FSS is composed of ceramic resonators with different band stop responses under front and side incidences. By mechanically tuning the orientation of the ceramic resonators, reconfigurable electromagnetic (EM) responses between two adjacent stopbands can be achieved. The two broad stopbands originate from the first two resonant modes of the ceramic resonators. As an example, a reconfigurable FSS composed of cross-shaped ceramic resonators is demonstrated. Both numerical and experimental results show that the FSS can switch between two consecutive stopbands in 3.55-4.60 GHz and 4.54-4.94 GHz. The design method can be readily extended to the design of FSSs in other frequencies for high-power applications.

Microwave birefringent metamaterials for polarization conversion based on spoof surface plasmon polariton modes.

We propose the design of wideband birefringent metamaterials based on spoof surface plasmon polaritons (SSPPs). Spatial k-dispersion design of SSPP modes in metamaterials is adopted to achieve high-efficiency transmission of electromagnetic waves through the metamaterial layer. By anisotropic design, the transmission phase accumulation in metamaterials can be independently modulated for x- and y-polarized components of incident waves. Since the dispersion curve of SSPPs is nonlinear, frequency-dependent phase differences can be obtained between the two orthogonal components of transmitted waves. As an example, we demonstrate a microwave birefringent metamaterials composed of fishbone structures. The full-polarization-state conversions on the zero-longitude line of Poincaré sphere can be fulfilled twice in 6-20 GHz for both linearly polarized (LP) and circularly polarized (CP) waves incidence. Besides, at a given frequency, the full-polarization-state conversion can be achieved by changing the polarization angle of the incident LP waves. Both the simulation and experiment results verify the high-efficiency polarization conversion functions of the birefringent metamaterial, including circular-to-circular, circular-to-linear(linear-to-circular), linear-to-linear polarization conversions.