Hypoxia-Inducible Factor-2 Alpha Regulates the Migration of Fibroblast-like Synoviocytes via Oxidative Stress-Induced CD70 Expression in Patients with Rheumatoid Arthritis

This study aimed to examine the role of CD70, which is highly expressed on fibroblast-like synoviocytes (FLS), in rheumatoid arthritis (RA) patients. FLS isolated from RA (n = 14) and osteoarthritis (OA, n = 4) patients were stimulated with recombinant interleukin-17 (IL-17; 5 ng/mL) and tumor necrosis factor alpha (TNF-α; 5 ng/mL) for 24 h. Expression of CD70, CD27/soluble CD27 (sCD27), and hypoxia-inducible factor-2 alpha (HIF-2α) was analyzed by RT-qPCR, flow cytometry, and ELISA assays, respectively. Reactive oxygen species (ROS) expression and cell migration were also examined. The HIF-2α inhibitor PT-2385 and CD70 inhibitor BU69 were used to specifically suppress these pathways. Stimulation with IL-17 and TNF-α significantly induced CD70 expression in RA FLS. Although the synovial fluids from patients with RA contained high levels of sCD27, surface expression of CD27, a ligand of CD70, was rarely detected in RA FLS. Cytokine-induced CD70 expression was significantly decreased following antioxidant treatment. Following HIF-2α inhibition, RA FLS had decreased expression of CD70 and ROS levels. Migration of RA FLS was also inhibited by inhibition of CD70 or HIF-2α. The surface expression of CD70 is regulated by HIF-2α and ROS levels and is a key contributor to cytokine-enhanced migration in RA FLS.     

Origins of High Performance and Degradation in the Mixed Perovskite Solar Cells

The origins of the high device performance and degradation in the air are the greatest issues for commercialization of perovskite solar cells. Here this study investigates the possible origins of the mixed perovskite cells by monitoring defect states and compositional changes of the perovskite layer over the time. The results of deep‐level transient spectroscopy analysis reveal that a newly identified defect formed by Br atoms exists at deep levels of the mixed perovskite film, and its defect state shifts when the film is aged in the air. The change of the defect state is originated from loss of the methylammonium molecules of the perovskite layer, which results in decreased J_SC, deterioration of the power conversion efficiency and long‐term stability of perovskite solar cells. The results provide a powerful strategy to diagnose and manage the efficiency and stability of perovskite solar cells.     

A Room‐Temperature Ferroelectric Ferromagnet in a 1D Tetrahedral Chain Network

Ferroelectricity occurs in crystals with broken spatial inversion symmetry. In conventional perovskite oxides, concerted ionic displacements within a 3D network of transition‐metal–oxygen polyhedra (MO_x) manifest spontaneous polarization. Meanwhile, some 2D networks of MO_x foster geometric ferroelectricity with magnetism, owing to the distortion of the polyhedra. Because of the fundamentally different mechanism of ferroelectricity in a 2D network, one can further challenge an uncharted mechanism of ferroelectricity in a 1D channel of MO_x and estimate its feasibility. Here, ferroelectricity and coupled ferromagnetism in a 1D FeO₄ tetrahedral chain network of a brownmillerite SrFeO_2.5 epitaxial thin film are presented. The result provides a new paradigm for designing low‐dimensional MO_x networks, which is expected to benefit the realization of macroscopic ferro‐ordering materials including ferroelectric ferromagnets.     

Parallel anisotropic 3D mesh adaptation by mesh modification

Improvements to a local modification-based anisotropic mesh adaptation procedure are presented. The first improvement focuses on control of the local operations that modify the mesh to satisfy the given anisotropic mesh metric field. The second is the parallelization of the mesh modification procedures to support effective parallel adaptive analysis. The resulting procedures are demonstrated on general curved 3D domains where the anisotropic mesh size field is defined by either an analytic expression or by an adaptive correction indicator as part of a flow solution process.

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Relay-based single carrier transmission with SFBC in uplink fast fading channels

This letter proposes a relay-based single carrier frequency-domain equalization (SC-FDE) with space-frequency block code (SFBC) in a distributed fashion. The proposed scheme achieves spatial diversity in uplink fast fading channels without the complexity of multiple antennas at source (mobile equipment). The source of the proposed system has a very simple transmitter structure without any increase of peak-to-average power ratio (PAPR). In order to obtain spatial diversity, the transmit sequence of relay is efficiently generated in the time domain, which realizes the SFBC. The corresponding destination structure and frequency domain equalization are also presented. Simulation result shows that the proposed system considerably outperforms the distributed space-time block code (D-STBC) SC-FDE over fast fading channels.     

Fully automated interoperability test suite derivation for communication protocols

We propose an automatic test derivation method for testing interoperability of communication protocols. It first derives a skeleton test suite for control part through a sort of reachability analysis. Next, it parameterizes each test case. Finally, it completes the test suite by actualizing test cases by assigning values to their parameters. By constructing test case space based on stable states and by basing test case actualization step on orthogonal arrays used in experimental design techniques, state space explosion is avoided. In order to demonstrate the feasibility and effectiveness, out method is applied to the ATM/B-ISDN signaling protocol and TCP. The application results show that our method surpasses the conventional methods in terms of both test size and coverage.     

Age-hardening characteristics of a dental low-carat gold alloy with dual hardener system of In and Cu

The age-hardening characteristics of a dental low carat gold alloy with a dual hardener system of indium (In) and Cu (33.9 Au–26.2 Ag–20.28 Cu–9.8 Pd–7.8 In–2 Zn (at%)) were examined by observing the age hardenability and related phase transformation, microstructural changes and elemental distribution during the aging process at 400°C. The dual hardener system by the use of both In and Cu provided more powerful hardening effect compared to a single-hardener system of In or Cu, without the formation of a AuCu type ordered phase. The alloy showed apparent initial hardening, which was attributed to the pre-precipitation or zone formation by the help of quenched in excess vacancies. During the constant increase in hardness, the single parent phase separated into three phases, Au–Ag-based phase, Au–Cu-based phase containing Pd and In, and InPd-based phase, through a metastable state. Indium which was added as one of the hardeners induced initial grain boundary precipitation, followed by an expansion of the lamellar structure, which was responsible for softening. The alternative lamellar structure was composed of a Cu-rich layer (Au–Cu-based phase containing Pd and In) and an Ag-rich layer (Au–Ag-based phase) replaced partly by the InPd-based phase. Separation of the Ag-rich layer from the Cu-rich layer is based on the miscibility limit of Ag and Cu due to their eutectic property.     

Hybridized surface-plasmon resonances of platinum colloid-adsorbed gold nanospheres

The surface-plasmon resonances of gold nanospheres dispersed in water split into two bands and shift to the red with the adsorption of colloidal platinum. These spectral changes are quite different from both the calculated and the experimental spectral variations of gold nanospheres with the thickness of coating platinum. Thus, these spectral changes have been attributed to the elementary plasmon interactions of the core gold and the adsorbed colloidal platinum as well as to the modification of the medium refraction index of the gold nanospheres. A simple and intuitive picture has been drawn to describe the hybridization plasmon interactions of a platinum colloid-adsorbed gold nanosphere.     

Optimization of organic bi-layer solar cell through systematic study of anode treatment and material thickness

The performance of bi-layer organic solar cells with the structure ITO/PEDOT:PSS/CuPc/C₆₀/BCP/Al was optimized. Prior to cell deposition, an optimal indium tin oxide (ITO) surface treatment technique was determined, with N₂ plasma treatment providing the highest solar cell efficiency. Parametric studies were performed to identify optimal fabrication conditions and deposition thicknesses for each layer by using solar cell efficiency as the primary performance measure.     

Structural and chemical characterization of fluorinated amorphous carbon films (a-C:F) as a liquid crystal alignment layer

a-C:F thin films with varying fluorine content were prepared by plasma CVD and the sputtering method as inorganic alignment layers for overcoming the disadvantages of conventional liquid crystal (LC) alignment layers. The material and structural properties were investigated by X-ray photoelectron spectroscopy, Fourier transform infrared absorption, and contact angle measurement. For elucidation of the liquid crystal alignment layers, LC cells with a-C:F films were fabricated, followed by examination of the textures of the LC and electro-optical characteristics. The fluorine concentrations of a-C:F films were controlled by changing the mixture gas ratio (R_G) in CVD and applied power ratio (R_P) in the sputter system. An increase in R_G and R_P led to increase fluorine incorporation, and the film microstructure changed from a diamond-like to a polymer-like structure. In addition, the sputtered a-C:F films showed a higher fluorination than the CVD sample since the PTFE target was only composed of CF₂ functional groups. Surface composition influenced the surface energy of thin films and an extremely hydrophobic property was obtained in the case of fluorine-rich a-C:F films. LC orientations were observed in various compositions of a-C:F films, and the vertically self-aligned LC textures confirmed that a sputtered a-C:F film is a good candidate for an alignment layer without any post-treatment.