One‐Dimensional Cuprous Selenide Nanostructures with Switchable Plasmonic and Super‐ionic Phase Attributes

Cuprous selenide nanocrystals have hallmark attributes, especially tunable localized surface plasmon resonances (LSPRs) and super‐ionic behavior. These attributes of cuprous selenide are now integrated with a one‐dimensional morphology. Essentially, Cu₂Se nanowires (NWs) of micrometer‐scale lengths and about 10 nm diameter are prepared. The NWs exhibit a super‐ionic phase that is stable at temperatures lower than in the bulk, owing to compressive lattice strain along the radial dimension of the NWs. The NWs can be switched between oxidized and reduced forms, which have contrasting phase transition and LSPR characteristics. This work thus makes available switchable, one‐dimensional waveguides and ion‐conducting channels.     

The Protective Effect of Violaxanthin from Nannochloropsis oceanica against Ultraviolet B‐Induced Damage in Normal Human Dermal Fibroblasts

Skin photoaging, which is mainly induced by ultraviolet B (UVB) radiation, is prevented by the application of UV‐protective agents. The microalga Nannochloropsis oceanica (N. oceanica) has been primarily reported as a potential biofuel; however, in this study, we investigated whether N. oceanica extracts exerted photoprotective effects against UVB‐irradiated human dermal fibroblasts (HDFs) and which single component was responsible for the protective effect of the extracts. Two extracts—pigment and nonpigment—were prepared from N. oceanica biomass. WST‐1 assay and expression analysis of interleukin genes showed that the pigment extracts were not significantly cytotoxic to HDFs. Further experiments revealed that treatment with the pigment extract upregulated the expression of collagen genes and significantly blocked UVB‐induced damage such as decreased cell viability and increased ROS production. Next, to investigate the pigment composition of the extracts, HPLC analysis was conducted and violaxanthin was identified as the major pigment. The UVB photoprotective effect of the pigment extracts was confirmed in violaxanthin‐treated HDFs. In addition, violaxanthin significantly attenuated UVB‐induced G1 phase arrest, senescence‐associated β‐galactosidase activation, p16 and p21 upregulation, ERK phosphorylation and the downregulation of ECM molecules in HDFs. Therefore, we concluded that violaxanthin was a potential antiphotoaging agent.     

A highly regioselective synthesis of 2-aryl-6-chlorobenzothiazoles employing microwave-promoted Suzuki-Miyaura coupling reaction

Suzuki-Miyaura coupling reactions of 2,6-dichlorobenzothiazole with arylboronic acids, promoted by microwave heating, efficiently produce 2-aryl-6-chlorobenzothiazoles in a highly regioselective manner. This process serves as the foundation for a simple method to rapidly construct 2-aryl-6-chlorobenzothiazole libraries.     

In-duct identification of fluid-borne source with high spatial resolution

Source identification of acoustic characteristics of in-duct fluid machinery is required for coping with the fluid-borne noise. By knowing the acoustic pressure and particle velocity field at the source plane in detail, the sound generation mechanism of a fluid machine can be understood. The identified spatial distribution of the strength of major radiators would be useful for the low noise design. Conventional methods for measuring the source in a wide duct have not been very helpful in investigating the source properties in detail because their spatial resolution is improper for the design purpose. In this work, an inverse method to estimate the source parameters with a high spatial resolution is studied. The theoretical formulation including the evanescent modes and near-field measurement data is given for a wide duct. After validating the proposed method to a duct excited by an acoustic driver, an experiment on a duct system driven by an air blower is conducted in the presence of flow. A convergence test for the evanescent modes is performed to find the necessary number of modes to regenerate the measured pressure field precisely. By using the converged modal amplitudes, very-close near-field pressure to the source is regenerated and compared with the measured pressure, and the maximum error was −16.3 dB. The source parameters are restored from the converged modal amplitudes. Then, the distribution of source parameters on the driver and the blower is clearly revealed with a high spatial resolution for kR<1.84 in which range only plane waves can propagate to far field in a duct. Measurement using a flush mounted sensor array is discussed, and the removal of pure radial modes in the modeling is suggested.     

Glass formation and third-order optical nonlinear properties within TeO2–Bi2O3–BaO pseudo-ternary system

Tellurite glasses from TeO₂–Bi₂O₃–BaO pseudo-ternary system were prepared using a conventional melt-quenching method and its glass-forming region was determined. A series of glasses were selected and their third-order optical nonlinearities (TONL) were measured by employing the Z-scan method at a wavelength of 800 nm with femtosecond laser pulses. The results showed that glass former Te⁴⁺ ions exhibited positive influences on the TONL and glass modifiers Ba²⁺ ions behaved similarly; low concentrated Bi³⁺ ions as glass modifiers weakened the nonlinearities, but an excess amount of Bi³⁺ behaved oppositely. FTIR measurements demonstrated that chemical bonds especially Te–O_eq vibrated at a high energy level remarkably promoted the TONL susceptibility χ⁽³⁾, and the glass sample with the highest Bi₂O₃ content exhibited the largest χ⁽³⁾ value which was due to the presence of BiO₃ polyhedra.     

Exploring uses of persistent homology for statistical analysis of landmark-based shape data

A method for the use of persistent homology in the statistical analysis of landmark-based shape data is given. Three-dimensional landmark configurations are used as input for separate filtrations, persistent homology is performed, and persistence diagrams are obtained. Groups of configurations are compared using distances between persistence diagrams combined with dimensionality reduction methods. A three-dimensional landmark-based data set is used from a longitudinal orthodontic study, and the persistent homology method is able to distinguish clinically relevant treatment effects. Comparisons are made with the traditional landmark-based statistical shape analysis methods of Dryden and Mardia, and Euclidean Distance Matrix Analysis.     

Targeted Degradation of Transcription Coactivator SRC-1 through the N-Degron Pathway

Aberrantly elevated steroid receptor coactivator-1 (SRC-1) expression and activity are strongly correlated with cancer progression and metastasis. Here we report, for the first time, the development of a proteolysis targeting chimera (PROTAC) that is composed of a selective SRC-1 binder linked to a specific ligand for UBR box, a unique class of E3 ligases recognizing N-degrons. We showed that the bifunctional molecule efficiently and selectively induced the degradation of SRC-1 in cells through the N-degron pathway. Importantly, given the ubiquitous expression of the UBR protein in most cells, PROTACs targeting the UBR box could degrade a protein of interest regardless of cell types. We also showed that the SRC-1 degrader significantly suppressed cancer cell invasion and migration in vitro and in vivo. Together, these results demonstrate that the SRC-1 degrader can be an invaluable chemical tool in the studies of SRC-1 functions. Moreover, our findings suggest PROTACs based on the N-degron pathway as a widely useful strategy to degrade disease-relevant proteins.     

Absorption and photoluminescence of PbS QDs in glasses

Optical properties of PbS quantum dots (QDs) precipitated inside the oxide glass matrix were investigated. Photoluminescence (PL) from the PbS QDs showed peak wavelengths located at 1170–1680 nm with widths of 150–550 nm. Radii of QDs in glasses were 2.3–4.7 nm depending upon the thermal treatment. Peak wavelengths of PL bands shifted as much as 70 nm as the temperatures and excitation irradiances increased. Calculated effective local temperatures indicated that these shifts of PL spectra were associated with local heating induced by the temperatures and laser beam.     

Preparation of cholesteric liquid crystal microcapsules for application in colour image storage media

Cholesteric liquid crystal (CLC) microcapsules for application in image storage media can be obtained via a diffusion-controlled polymerization method (DPM). To improve the swelling of the CLC seed particle, in poly(methylmethacrylate) (PMMA), a polymerizable acrylate based on a cholesterol moiety was synthesized and copolymerized with MMA to prepare the seed particle. As a result, monodispersed and CLC core/shell-structured microcapsules may be obtained. The resulting CLC microcapsules selectively, absorbed visible light at around 660 nm, and so appeared blue in the mesophase. Polymer dispersed cholesteric liquid crystal (PDCLC) cells were prepared using the CLC microcapsules, and were used as an image storage medium in reversible writing/erasing experiments.     

Mitochondrial pyruvate dehydrogenase phosphatase 1 regulates the early differentiation of cardiomyocytes from mouse embryonic stem cells

Mitochondria are crucial for maintaining the properties of embryonic stem cells (ESCs) and for regulating their subsequent differentiation into diverse cell lineages, including cardiomyocytes. However, mitochondrial regulators that manage the rate of differentiation or cell fate have been rarely identified. This study aimed to determine the potential mitochondrial factor that controls the differentiation of ESCs into cardiac myocytes. We induced cardiomyocyte differentiation from mouse ESCs (mESCs) and performed microarray assays to assess messenger RNA (mRNA) expression changes at differentiation day 8 (D8) compared with undifferentiated mESCs (D0). Among the differentially expressed genes, Pdp1 expression was significantly decreased (27-fold) on D8 compared to D0, which was accompanied by suppressed mitochondrial indices, including ATP levels, membrane potential, ROS and mitochondrial Ca²⁺. Notably, Pdp1 overexpression significantly enhanced the mitochondrial indices and pyruvate dehydrogenase activity and reduced the expression of cardiac differentiation marker mRNA and the cardiac differentiation rate compared to a mock control. In confirmation of this, a knockdown of the Pdp1 gene promoted the expression of cardiac differentiation marker mRNA and the cardiac differentiation rate. In conclusion, our results suggest that mitochondrial PDP1 is a potential regulator that controls cardiac differentiation at an early differentiation stage in ESCs.