Ultralow-Permittivity and Temperature-Stable Ba1-xCaxMg2Al6Si9O30 Dielectric Ceramics for C-Band Patch Antenna Applications.

Ca-substituted Ba1-xCaxMg2Al6Si9O30 ceramics were prepared to explore the relationships among their crystal structural parameters, phase compositions, dielectric properties, and coefficients of thermal expansion and applications in C-band antenna. The maximum solubility of Ba1-xCaxMg2Al6Si9O30 was located at x = 0.25, and Ba1-xCaxMg2Al6Si9O30 ceramics (0 ≤ x ≤ 0.25) crystallized in the space group P6/mcc. In Ba1-xCaxMg2Al6Si9O30 single-phase ceramics, εr was dominated by ionic polarizability and "rattling effects" of Ba2+ and Al(2)3+; Q × f was controlled by the roundness of [Si4Al2O18] inner rings and total lattice energy; and τf was affected by the bond valence of Si/Al(1)-O(1). Notably, the low average coefficients of thermal expansion (2.668 ppm/°C) at -150 °C ≤ T ≤ 850 °C and near-zero coefficients of thermal expansion (1.254 ppm/°C) at -150 °C ≤ T ≤ 260 °C were achieved for the Ba1-xCaxMg2Al6Si9O30 (x = 0.1) ceramic. Optimum microwave and terahertz dielectric properties were obtained for the Ba1-xCaxMg2Al6Si9O30 (x = 0.1) ceramic with εr = 5.80, Q × f = 31,174 at 13.99 GHz, τf = -7.10 ppm/°C, and εr = 5.71-5.85 at 0.2 THz ≤ f ≤ 1.0 THz. Also, the Ba1-xCaxMg2Al6Si9O30 (x = 0.1) ceramic substrate had been designed as a C-band patch antenna with a high simulated radiation efficiency (87.76%) and gain (6.30 dBi) at 7.70 GHz (|S11| = -38.41 dB).

Methylation and transcriptomic expression profiles of HUVEC in the oxygen and glucose deprivation model and its clinical implications in AMI patients.

The obstructed coronary artery undergoes a series of pathological changes due to ischemic-hypoxic shocks during acute myocardial infarction (AMI). However, the altered DNA methylation levels in endothelial cells under these conditions and their implication for the etiopathology of AMI have not been investigated in detail. This study aimed to explore the relationship between DNA methylation and pathologically altered gene expression profile in human umbilical vein endothelial cells (HUVECs) subjected to oxygen-glucose deprivation (OGD), and its clinical implications in AMI patients. The Illumina Infinium MethylationEPIC BeadChip assay was used to explore the genome-wide DNA methylation profile using the Novaseq6000 platform for mRNA sequencing in 3 pairs of HUVEC-OGD and control samples. GO and KEGG pathway enrichment analyses, as well as correlation, causal inference test (CIT), and protein-protein interaction (PPI) analyses identified 22 hub genes that were validated by MethylTarget sequencing as well as qRT-PCR. ELISA was used to detect four target molecules associated with the progression of AMI. A total of 2,524 differentially expressed genes (DEGs) and 22,148 differentially methylated positions (DMPs) corresponding to 6,642 differentially methylated genes (DMGs) were screened (|Δß|>0.1 and detection p < 0.05). After GO, KEGG, correlation, CIT, and PPI analyses, 441 genes were filtered. qRT-PCR confirmed the overexpression of VEGFA, CCL2, TSP-1, SQSTM1, BCL2L11, and TIMP3 genes, and downregulation of MYC, CD44, BDNF, GNAQ, RUNX1, ETS1, NGFR, MME, SEMA6A, GNAI1, IFIT1, and MEIS1. DNA fragments BDNF_1_ (r = 0.931, p < 0.0001) and SQSTM1_2_NEW (r = 0.758, p = 0.0043) were positively correlated with the expressions of corresponding genes, and MYC_1_ (r = -0.8245, p = 0.001) was negatively correlated. Furthermore, ELISA confirmed TNFSF10 and BDNF were elevated in the peripheral blood of AMI patients (p = 0.0284 and p = 0.0142, respectively). Combined sequencing from in vitro cellular assays with clinical samples, aiming to establish the potential causal chain of the causal factor (DNA methylation) - mediator (mRNA)-cell outcome (endothelial cell ischemic-hypoxic injury)-clinical outcome (AMI), our study identified promising OGD-specific genes, which provided a solid basis for screening fundamental diagnostic and prognostic biomarkers of coronary endothelial cell injury of AMI. Moreover, it furnished the first evidence that during ischemia and hypoxia, the expression of BNDF was regulated by DNA methylation in endothelial cells and elevated in peripheral blood.

Virtual differential phase-contrast and dark-field imaging of x-ray absorption images via deep learning.

Weak absorption contrast in biological tissues has hindered x-ray computed tomography from accessing biological structures. Recently, grating-based imaging has emerged as a promising solution to biological low-contrast imaging, providing complementary and previously unavailable structural information of the specimen. Although it has been successfully applied to work with conventional x-ray sources, grating-based imaging is time-consuming and requires a sophisticated experimental setup. In this work, we demonstrate that a deep convolutional neural network trained with a generative adversarial network can directly convert x-ray absorption images into differential phase-contrast and dark-field images that are comparable to those obtained at both a synchrotron beamline and a laboratory facility. By smearing back all of the virtual projections, high-quality tomographic images of biological test specimens deliver the differential phase-contrast- and dark-field-like contrast and quantitative information, broadening the horizon of x-ray image contrast generation.

Hybrid dual-mode tunable polarization conversion metasurface based on graphene and vanadium dioxide.

We present and numerically verify a functionally hybrid dual-mode tunable polarization conversion metasurface based on graphene and vanadium dioxide (VO2). The tunable polarization converter consists of two patterned graphene layers separated by grating which is composed of gold and VO2. Due to the existence of phase change material VO2, the polarization conversion mode can be switched flexibly between the transmission and reflection modes. Theoretical calculations show the proposed polarization conversion metasurface can obtain giant asymmetric transmission (AT) at 0.42 and 0.77 THz when VO2 is in the insulating state. Conversely, when VO2 is in the metallic state, the converter switches to the reflection mode, demonstrating broadband polarization conversion for both forward and backward incidences. Furthermore, the conductivity of graphene can be modulated by changing the gate voltage, which allows dynamic control polarization conversion bandwidth of the reflection mode as well as the AT of the transmission mode. The robustness of the metasurface has also been verified, the high polarization conversion efficiency and AT can be maintained over wide incidence angles up to 65° for both the xoz plane and yoz plane. These advantages make the proposed hybrid tunable polarization conversion metasurface a promising candidate for THz radiation switching and modulation.

Anti-High-Power Microwave RFID Tag Based on Highly Thermal Conductive Graphene Films.

In this paper, a radio frequency identification (RFID) tag is designed and fabricated based on highly electrical and thermal conductive graphene films. The tag operates in the ultrahigh-frequency (UHF) band, which is suitable for high-power microwave environments of at least 800 W. We designed the protection structure to avoid charge accumulation at the antenna's critical positions. In the initial state, the read range of the anti-high-power microwave graphene film tag (AMGFT) is 10.43 m at 915 MHz. During the microwave heating experiment, the aluminum tag causes a visible electric spark phenomenon, which ablates the aluminum tag and its attachment, resulting in tag failure and serious safety issues. In contrast, the AMGFT is intact, with its entire read range curve growing and returning to its initial position as its temperature steadily decreases back to room temperature. In addition, the proposed dual-frequency tag further confirms the anti-high-power microwave performance of graphene film tags and provides a multi-scenario interactive application.

Synthesis of morphology-controlled N-doped porous carbon for simultaneous electrochemical sensing of dihydroxybenzene isomers.

Different morphology of N-doped carbon materials, including three-dimensional interconnected N-doped hierarchically porous carbon networks (3D-NC), two-dimensional ultrathin porous carbon nanosheets (2D-NC), and bulk N-doped carbon with micron size (bulk-NC), was easily prepared by using NaCl crystal templates-assisted strategy. Compared with bare glassy carbon, bulk-NC, and 2D-NC, the as-synthesized 3D-NC exhibits excellent electrochemical activity toward the oxidation and sensing of three kinds of common environmental pollutants dihydroxybenzene isomers (hydroquinone (HQ), catechol (CC), and resorcinol (RS)). The impressive electrochemical activity of 3D-NC can be interpreted by its large specific surface area, continuous network-like morphology, superior electro-catalytic ability, and strong accumulation efficiency. Differential pulse voltammetry (DPV) test showed the 3D-NC-modified electrode exhibited three well-separated oxidation peaks at 0.05 V, 0.14 V, and 0.45 V vs. saturated calomel electrode (SCE) for HQ, CC, and RS, and their detection limits were evaluated to be as low as 0.0044, 0.012, and 0.016 mg L-1, respectively. Finally, a novel electrochemical analytical platform is successfully fabricated for the simultaneous monitoring of hydroquinone, catechol, and resorcinol with high sensitivity. When used for real wastewater samples analysis, recovery ratio ranging from 94 to 108% with lower than 5% of relative standard deviation (RSD) values was achieved. This work proves a facile strategy to prepare morphology-controlled N-doped carbon-based material and demonstrates its high application potential for environmental monitoring and electrochemical analysis.

Boundary configured chiral edge states in valley topological photonic crystal.

Chiral edge states (CESs) have been demonstrated at the external boundary of a valley photonic crystal (VPC), with flexibly tunable group velocity and frequency range by adjusting the boundary structure. In this work, we show parallel and antiparallel CESs located at two opposite VPC-air boundaries, which contain wave components belonging to opposite valleys or the same valley. In addition, we design a meta-structure with four types of air-contacted boundary that support CESs in different frequency ranges. The structure also has an internal interface channel supporting the valley edge state that bridges the top and bottom boundaries. We show that the CESs, while excited at a given port, can be exclusively guided to the other three ports, depending on the operating frequency. Our work provides an alternative way to design compact topological devices for optical waveguides and wave splitters.

Endotoxins Induced ECM-Receptor Interaction Pathway Signal Effect on the Function of MUC2 in Caco2/HT29 Co-Culture Cells.

Endotoxins are toxic substances that widely exist in the environment and can enter the intestine with food and other substances. Intestinal epithelial cells are protected by a mucus layer that contains MUC2 as its main structural component. However, a detailed understanding of the mechanisms involved in the function of the mucus barrier in endotoxin penetration is lacking. Here, we established the most suitable proportion of Caco-2/HT-29 co-culture cells as a powerful tool to evaluate the intestinal mucus layer. Our findings significantly advance current knowledge as focal adhesion and ECM-receptor interaction were identified as the two most significantly implicated pathways in MUC2 small interfering RNA (siRNA)-transfected Caco-2/HT-29 co-culture cells after 24 h of LPS stimulation. When the mucus layer was not intact, LPS was found to damage the tight junctions of Caco-2/HT29 co-cultured cells. Furthermore, LPS was demonstrated to inhibit the integrin-mediated focal adhesion structure and damage the matrix network structure of the extracellular and actin microfilament skeletons. Ultimately, LPS inhibited the interactive communication between the extracellular matrix and the cytoskeleton for 24 h in the siMUC2 group compared with the LPS(+) and LPS(-) groups. Overall, we recognized the potential of MUC2 as a tool for barrier function in several intestinal bacterial diseases.

The XPO1 Inhibitor KPT-8602 Ameliorates Parkinson's Disease by Inhibiting the NF-κB/NLRP3 Pathway.

Exportin 1 (XPO1) is an important transport receptor that mediates the nuclear export of various proteins and RNA. KPT-8602 is a second-generation inhibitor of XPO1, demonstrating the lowest level of side effects, and is currently in clinical trials for the treatment of cancers. Previous studies suggest that several first-generation inhibitors of XPO1 demonstrate anti-inflammation activities, indicating the application of this drug in inflammation-related diseases. In this study, our results suggested the potent anti-inflammatory effect of KPT-8602 in vitro and in vivo. KPT-8602 inhibited the activation of the NF-κB pathway by blocking the phosphorylation and degradation of IκBα, and the priming of NLRP3. Importantly, the administration of KPT-8602 attenuated both lipopolysaccharide (LPS)-induced peripheral inflammation and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neuroinflammation in vivo. In addition, the tissue damage was also ameliorated by KPT-8602, indicating that KPT-8602 could be used as a novel potential therapeutic agent for the treatment of inflammasome-related diseases such as Parkinson's disease, through the regulation of the NF-κB signaling pathway and the NLRP3 inflammasome.

Terahertz Chiral Metamaterials Enabled by Textile Manufacturing.

Easy-to-fabricate, large-area, and inexpensive microstructures that realize control of the polarization of terahertz (THz) radiation are of fundamental importance to the development of the field of THz wave photonics. However, due to the lack of natural materials that can facilitate strong THz radiation-matter interactions, THz polarization components remain an undeveloped technology. Strong resonance-based responses offered by THz metamaterials have led to the recent development of THz metadevices, whereas, for polarization control devices, micrometer-scale fabrication techniques including aligned photolithography are generally required to create multilayer microstructures. In this work, leveraging a two-step textile manufacturing approach, a chiral metamaterial capable of exhibiting strong chiroptical responses at THz frequencies is demonstrated. Chiral-selective transmission and pronounced optical activity are experimentally observed. In sharp contrast to smart-clothing-related devices (e.g., textile antennas), the investigated chiral metamaterials gain their THz properties directly from the yarn-twisting enabled microhelical strings. It is envisioned that the interplay between meta-atom designs and textile manufacturing technology will lead to a new family of metadevices for complete control over the phase, amplitude, and polarization of THz radiation.

Generalized reverse projection method for grating-based phase tomography.

The reverse projection protocol results in fast phase-contrast imaging thanks to its compatibility with conventional computed-tomography scanning. Many researchers have proposed variants. However, all these reverse projection methods in grating-based phase-contrast imaging are built on the hypothesis of the synchronous phase of reference shifting curves in the whole field of view. The hypothesis imposes uniformity and alignment requirements on the gratings, thus the field of view is generally limited. In this paper, a generalized reverse projection method is presented analytically for the case of non-uniform reference in grating-based phase tomography. The method is demonstrated by theoretical derivation, numerical simulations and synchrotron radiation experiments. The influence of imaging position to sensitivity, and the phase-wrapping phenomenon are also discussed. The proposed method combines the advantages of the high efficiency of the reverse projection method and the universal applicability of the phase-stepping method. The authors believe that the method would be used widely in fast and dose-constrained imaging.

Magnon-tuning non-volatile magnetic dynamics in a CoZr/PMN-PT structure.

Magnon-tuning non-volatile magnetic dynamics is investigated in a CoZr/PMN-PT structure by measuring ferromagnetic resonance at room temperature. The electric-field control of ferromagnetic resonance shows loop-like behavior, which indicates non-volatile electric-field control of the magnetism. Further, fitting the curves of in-plane rotating angle versus ferromagnetic resonance field under different electric fields shows that the effective magnetic field changes in loop-like manner with the electric field. The resulting change in non-volatile saturation magnetization with electric field is consistent with that of a polarization electric field curve. A 1.04% change of saturation magnetization is obtained, which can be attributed to a magnon-driven magnetoelectric coupling at the CoZr/PMN-PT interface. This magnon-driven magnetoelectric coupling and its dynamic magnetic properties are significant for developing future magnetoelectric devices.

Limited angle tomography for transmission X-ray microscopy using deep learning.

In transmission X-ray microscopy (TXM) systems, the rotation of a scanned sample might be restricted to a limited angular range to avoid collision with other system parts or high attenuation at certain tilting angles. Image reconstruction from such limited angle data suffers from artifacts because of missing data. In this work, deep learning is applied to limited angle reconstruction in TXMs for the first time. With the challenge to obtain sufficient real data for training, training a deep neural network from synthetic data is investigated. In particular, U-Net, the state-of-the-art neural network in biomedical imaging, is trained from synthetic ellipsoid data and multi-category data to reduce artifacts in filtered back-projection (FBP) reconstruction images. The proposed method is evaluated on synthetic data and real scanned chlorella data in 100° limited angle tomography. For synthetic test data, U-Net significantly reduces the root-mean-square error (RMSE) from 2.55 × 10-3 µm-1 in the FBP reconstruction to 1.21 × 10-3 µm-1 in the U-Net reconstruction and also improves the structural similarity (SSIM) index from 0.625 to 0.920. With penalized weighted least-square denoising of measured projections, the RMSE and SSIM are further improved to 1.16 × 10-3 µm-1 and 0.932, respectively. For real test data, the proposed method remarkably improves the 3D visualization of the subcellular structures in the chlorella cell, which indicates its important value for nanoscale imaging in biology, nanoscience and materials science.

Solvent Engineering of a Dopant-Free Spiro-OMeTAD Hole-Transport Layer for Centimeter-Scale Perovskite Solar Cells with High Efficiency and Thermal Stability.

High efficiency and environmental stability are mandatory performance requirements for commercialization of perovskite solar cells (PSCs). Herein, efficient centimeter-scale PSCs with improved stability were achieved by incorporating an additive-free 2,2',7,7'-tetrakis[N,N-di(p-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-OMeTAD) hole-transporting material (HTM) through simply substituting the usual chlorobenzene solvent with pentachloroethane (PC). A stabilized power conversion efficiency (PCE) of 16.1% under simulated AM 1.5G 1 sun illumination with an aperture of 1.00 cm2 was achieved for PSCs using an additive-free spiro-OMeTAD layer cast from PC. X-ray analysis suggested that chlorine radicals from PC transfer partially to spiro-OMeTAD and are retained in the HTM layer, resulting in conductivity improvement. Moreover, unencapsulated PSCs with a centimeter-scale active area cast from PC retained >70% of their initial PCE after ageing at 80 °C for 500 h, in contrast with less than 20% retention for control devices. Morphological and X-ray analyses of the aged cells revealed that the perovskite and HTM layers remain almost unchanged in the cells with a spiro-OMeTAD layer cast from PC whereas serious degradation occurred in the control cells. This study not only reveals the decomposition mechanism of PSCs in the presence of HTM additives but also opens up a broad range of organic semiconductors for radical doping.

Magnon-driven interfacial magnetoelectric coupling in Co/PMN-PT multiferroic heterostructures.

Magnon-driven interfacial magnetoelectric coupling in Co/PMN-PT multiferroic heterostructures is investigated at room temperature. The electric field controlled ferromagnetic resonance field possesses a loop-like curve, with a large resonance field shift between positive and negative remanent polarizations, which confirms a non-volatile strong magnetoelectric coupling. However, with a non-magnetic Ta layer inserted at the Co/PMN-PT interface, a piezostrain-induced butterfly-like curve of the resonance field versus applied electric field of the Co/Ta/PMN-PT multiferroic heterostructure is observed. Further, the non-volatile behavior of the resonance field changing with the applied electric field can be obtained, consistent with the result of polarization versus applied electric field curve, which can be attributed to the magnon-driven interfacial magnetoelectric coupling, showing a strong correlation of magnetization of Co thin film and the polarization of PMN-PT. The result is promising for the design of future multiferroic devices.

Vanadium dioxide based broadband THz metamaterial absorbers with high tunability: simulation study.

With their unprecedented flexibility in manipulating electromagnetic waves, metamaterials provide a pathway to structural materials that can fill the so-called "THz gap". It has been reported that vanadium dioxide (VO2) experiences a three orders of magnitude increase in THz electrical conductivity when it undergoes an insulator-to-metal transition. Here, we propose a VO2 based THz metamaterial absorber exhibiting broadband absorptivity that arises from the multiple resonances supported by a delicately balanced doubly periodic array of VO2 structures and numerically demonstrate that the corresponding absorption behavior is highly dependent on the VO2's THz electrical properties. Considering the phase transition induced dramatic change in VO2's material property, the proposed metamaterial absorbers have the potential for strong modulation and switching of broadband THz radiation.

Jitter correction for transmission X-ray microscopy via measurement of geometric moments.

Transmission X-ray microscopes (TXMs) have become one of the most powerful tools for imaging 3D structures of nano-scale samples using the computed tomography (CT) principle. As a major error source, sample jitter caused by mechanical instability of the rotation stage produces shifted 2D projections, from which reconstructed images contain severe motion artifacts. In this paper, a jitter correction algorithm is proposed, that has high accuracy and computational efficiency for TXM experiments with or without nano-particle markers. Geometric moments (GMs) are measured on segmented projections for each angle and fitted to sinusoidal curves in the angular direction. Sample jitter is estimated from the difference between the measured and the fitted GMs for image correction. On a digital phantom, the proposed method removes jitter errors at different noise levels. Physical experiments on chlorella cells show that the proposed GM method achieves better spatial resolution and higher computational efficiency than the re-projection method, a state-of-the-art algorithm using iterative correction. It even outperforms the approach of manual alignment, the current gold standard, on faithfully maintaining fine structures on the CT images. Our method is practically attractive in that it is computationally efficient and lowers experimental costs in current TXM studies without using expensive nano-particles markers.

Retraction Note to: SOX2 oncogenes amplified and operate to activate AKT signalling in gastric cancer and predict immunotherapy responsiveness.

The Editor-in-Chief is retracting this article (Tian et al 2014) due to concerns regarding peer review, authorship and originality of the article.

Highly Efficient Isolation of Circulating Tumor Cells Using a Simple Wedge-Shaped Microfluidic Device.

OBJECTIVE: We have developed a novel simple wedge-shaped microfluidic device for highly efficient isolation of circulating tumor cells (CTCs) from cancer patient blood samples. METHODS: We used wet chemical etching and thermal bonding technologies to fabricate the wedge-shaped microdevice and performed optimization assays to obtain optimal capture parameters. Cancer cells spiked samples were used to evaluate the capture performance. Clinical assays were performed to isolate and identify CTCs from whole blood samples of patients with liver, breast, lung, and gastric cancer. RESULTS: Outlet height of 5.5 µm and flow rate of 200 µL/min were chosen as the optimal CTC-capture conditions. This method exhibited excellent isolation performance (more than 85% capture efficiency) for four cancer cell lines (HepG2, SKBR3, A549, and BGC823). In clinical assay, the platform identified CTCs 5 in 6 liver (83.3%), 8 in 10 breast (80%), 5 in 8 lung (62.5%), 5 in 9 gastric (55.6%) cancer patients, and only 1 in 25 healthy blood samples (4%). CONCLUSION: Our wedge-shaped microfluidic device had several advantages, including relatively simple fabrication, high capture efficiency, simple sample processing steps, and easy observation. SIGNIFICANCE: This method had successfully demonstrated the clinical feasibility of CTC isolation and shown a great potential of clinical usefulness in monitoring tumor prognosis and guiding individualized treatment in the future.

A simple pyramid-shaped microchamber towards highly efficient isolation of circulating tumor cells from breast cancer patients.

Isolation and detection of circulating tumor cells (CTCs) has showed a great clinical impact for tumor diagnosis and treatment monitoring. Despite significant progresses of the existing technologies, feasible and cost-effective CTC isolation techniques are more desirable. In this study, a novel method was developed for highly efficient isolation of CTCs from breast cancer patients based on biophysical properties using a pyramid-shaped microchamber. Through optimization tests, the outlet height of 6 µm and the flow rate of 200 µL/min were chosen as the optimal conditions. The capture efficiencies of more than 85% were achieved for cancer cell lines (SKBR3, BGC823, PC3, and H1975) spiked in DMEM and healthy blood samples without clogging issue. In clinic assay, the platform identified CTCs in 13 of 20 breast cancer patients (65%) with an average of 4.25 ± 4.96 CTCs/2 mL, whereas only one cell was recognized as CTC in 1 of 15 healthy blood samples. The statistical analyses results demonstrated that both CTC positive rate and CTC counts were positive correlated with TNM stage (p < 0.001; p = 0.02, respectively). This microfluidic platform successfully demonstrated the clinical feasibility of CTC isolation and would hold great potential of clinical application in predicting and monitoring the prognosis of cancer patients.