Resolution-enhanced X-ray fluorescence microscopy via deep residual networks

Multimodal hard X-ray scanning probe microscopy has been extensively used to study functional materials providing multiple contrast mechanisms. For instance, combining ptychography with X-ray fluorescence (XRF) microscopy reveals structural and chemical properties simultaneously. While ptychography can achieve diffraction-limited spatial resolution, the resolution of XRF is limited by the X-ray probe size. Here, we develop a machine learning (ML) model to overcome this problem by decoupling the impact of the X-ray probe from the XRF signal. The enhanced spatial resolution was observed for both simulated and experimental XRF data, showing superior performance over the state-of-the-art scanning XRF method with different nano-sized X-ray probes. Enhanced spatial resolutions were also observed for the accompanying XRF tomography reconstructions. Using this probe profile deconvolution with the proposed ML solution to enhance the spatial resolution of XRF microscopy will be broadly applicable across both functional materials and biological imaging with XRF and other related application areas

Three-dimensional coherent X-ray diffraction imaging via deep convolutional neural networks

As a critical component of coherent X-ray diffraction imaging (CDI), phase retrieval has been extensively applied in X-ray structural science to recover the 3D morphological information inside measured particles. Despite meeting all the oversampling requirements of Sayre and Shannon, current phase retrieval approaches still have trouble achieving a unique inversion of experimental data in the presence of noise. Here, we propose to overcome this limitation by incorporating a 3D Machine Learning (ML) model combining (optional) supervised learning with transfer learning. The trained ML model can rapidly provide an immediate result with high accuracy which could benefit real-time experiments, and the predicted result can be further refined with transfer learning. More significantly, the proposed ML model can be used without any prior training to learn the missing phases of an image based on minimization of an appropriate ‘loss function’ alone. We demonstrate significantly improved performance with experimental Bragg CDI data over traditional iterative phase retrieval algorithms

FLUIDIZATION TECHNOLOGY FOR STABLE STARTUP OF COMMERCIAL FCC UNIT

Conditions for maintaining good fluidization in the start-up of FCC have been determined. Catalyst defluidization and consequent catalyst losses from reactor cyclone are mainly affected by catalyst properties and stripper operating condition based on previous commercial startup experiences. Effect of fine catalyst contents on bed fluidity was determined. Bed fluidity in stripper was analyzed with slip velocity. Finally new startup guide was proposed and it was successfully applied to commercial FCC process of SK energy, Korea

Transparent organic light-emitting diodes with different bi-directional emission colors using color-conversion capping layers

We report a study on transparent organic light-emitting diodes (OLEDs) with different bidirectional emission colors, enabled by color-conversion organic capping layers. Starting from a transparent blue OLED with an uncapped Ag top electrode exhibiting an average transmittance of 33.9%, a 4-(Dicyanomethylene)-2-methyl- 6-(4-dimethylaminostyryl)-4Hpyran (DCM)-doped tris-(8-hydroxy-quinolinato)-aluminium (Alq3) capping layer is applied to achieve color-conversion from blue to orange-red on the top side while maintaining almost unchanged device transmittance. This color-conversion capping layer does not only change the color of the top side emission, but also enhances the overall device efficiency due to the optical interaction of the capping layer with the primary blue transparent OLED. Top white emission from the transparent bi-directional OLED exhibits a correlated color temperature around 6,000K-7,000K, with excellent color stability as evidenced by an extremely small variation in color coordinate of ∆(x,y) = (0.002, 0.002) in the forward luminance range of 100-1000 cd m-2. At the same time, the blue emission color of bottom side is not influenced by the color conversion capping layer, which finally results in different emission colors of the two opposite sides of our transparent OLEDsPostprintPeer reviewe

Cordycepin promotes apoptosis by modulating the ERK-JNK signaling pathway via DUSP5 in renal cancer cells

Constitutive activation of extracellular signal regulated kinase (ERK)-Jun NH2-terminal kinase (JNK) signaling commonly occurs in tumors. The activation of ERK promotes cell proliferation, whereas that of JNK induces cell apoptosis. However, the apoptotic mechanism of ERK-JNK signaling in cancer is not well understood. Recently, we identified that apoptosis and activation of the JNK signaling pathway were induced after cordycepin treatment in human renal cancer, suggesting that JNK signaling might contribute to TK-10 cell apoptosis. We investigated the apoptotic effects of cordycepin by evaluating the activation of the ERK-JNK signaling pathway in renal cancer TK-10 cells. We found that cordycepin downregulated ERK and DUSP5, upregulated phosphorylated-JNK (p-JNK), and induced apoptosis. Moreover, we showed that siRNA-mediated inhibition of ERK downregulated DUSP5, whereas ERK overexpression upregulated DUSP5, and that DUSP5 knockdown by siRNA upregulated p-JNK. The JNK-specific inhibitor SP600125 upregulated nuclear translocation of β-catenin, and downregulated Dickkopf-1 (Dkk1), which has been shown to be a potent inhibitor of Wnt signaling. Dkk1 knockdown by siRNA upregulated nuclear β-catenin, suggesting the involvement of the Wnt/β-catenin signaling pathway. DUSP5 overexpression in TK-10 cells decreased p-JNK and increased nuclear β-catenin. The decreased Bax activation markedly protected against cordycepin-induced apoptosis. Bax subfamily proteins induced apoptosis through caspase-3. Taken together, we show that JNK signaling activation by cordycepin mediated ERK inhibition, which might have induced Bax translocation and caspase-3 activation via regulation of DUSP5 in TK-10 cells, thereby promoting the apoptosis of TK-10 cells. Targeting ERK-JNK signaling via the apoptotic effects of cordycepin could be a potential therapeutic strategy to treat renal cancer

Structurally tuned lead magnesium titanate perovskite as a photoelectrode material for enhanced photoelectrochemical water splitting

This is the first demonstration of four distinct types of Lead Magnesium Titanate (PMT) perovskites including spheres, flakes, hierarchical flower and thin microbelt shapes that were finely tuned via facile solution method to develop cost effective and high performance photoanode materials for water splitting. The influence of solvent effects during structural tuning, purity, morphology, optical absorption, structural phase transition and stoichiometric formation of the prepared Lead Magnesium Titanate perovskites has been discussed in detail. A remarkable observation is that the thin microbelts structured PMT perovskite (PMTT) exhibited an excellent water splitting performance and it is more sensitive to the illuminated visible light. Owing to the unique structural features, the photoconversion efficiency value of PMTT perovskite is ∼3.9, 3.54, 2.85 and 1.52 times higher than those of other prepared PMT perovskites including pristine PbTiO3. The excellent water splitting performance of PMTT (thin microbelts) may be ascribed to the remarkable structural features that include a large surface area, high optical absorbance, more active sites and high interface area of the microbelts, which provide large contact areas between the electrolyte and highly active materials for electrolyte diffusion and a rapid route for charge transfer with minimal diffusion resistance. In addition, each thin microbelt is directly in contact with the Ni foam substrate, which can also shorten the diffusion path for the electrons. The demonstrated approach paves the way for low-cost and high-throughput production of next generation, high performance and highly active water splitting perovskite photocatalysts.</p

Cordycepin inhibits human ovarian cancer by inducing autophagy and apoptosis through Dickkopf-related protein 1/β-catenin signaling

Cordycepin, the major active component from Cordyceps militaris, has been reported to significantly inhibit some types of cancer; however, its effects on ovarian cancer are still not well understood. In this study, we treated human ovarian cancer cells with different doses of cordycepin and found that it dose-dependently reduced ovarian cancer cell viability, based on Cell counting kit-8 reagent. Immunoblotting showed that cordycepin increased Dickkopf-related protein 1 (Dkk1) levels and inhibited β-catenin signaling. Atg7 knockdown in ovarian cancer cells significantly inhibited cordycepin-induced apoptosis, whereas β-catenin overexpression abolished the effects of cordycepin on cell death and proliferation. Furthermore, we found that Dkk1 overexpression by transfection downregulated the expression of c-Myc and cyclin D1. siRNA-mediated Dkk1 silencing downregulated the expression of Atg8, beclin, and LC3 and promoted β-catenin translocation from the cytoplasm into the nucleus. These results suggest that cordycepin inhibits ovarian cancer cell growth, possibly through coordinated autophagy and Dkk1/β-catenin signaling. Taken together, our findings provide new insights into the treatment of ovarian cancer using cordycepin