[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

2.3. Evaluation of Photocatalytic Water Splitting 6507 2.3.1. Photocatalytic Activity 6507 2.3.2. Photocatalytic Stability 6507 3. UV-Active Photocatalysts for Water Splitting 6507 3.1. d0 Metal Oxide Photocatalyts 6507 3.1.1. Ti-, Zr-Based Oxides 6507 3.1.2. Nb-, Ta-Based Oxides 6514 3.1.3. W-, Mo-Based Oxides 6517 3.1.4. Other d0 Metal Oxides 6518 3.2. d10 Metal Oxide Photocatalyts 6518 3.3. f0 Metal Oxide Photocatalysts 6518 3.4. Nonoxide Photocatalysts 6518 4. Approaches to Modifying the Electronic Band Structure for Visible-Light Harvesting 6519

Semiconductor-based Photocatalytic Hydrogen Generation

Chemokines, small proinflammatory chemoattractant cytokines that bind to specific G-protein-coupled seven-span transmembrane receptors, are major regulators of cell trafficking and adhesion. The chemokine CXCL12 [stromal cell-derived factor-1 (SDF-1)] binds primarily to CXC receptor 4 (CXCR4; CD184). The binding of CXCL12 to CXCR4 induces intracellular signaling through several divergent pathways initiating signals related to chemotaxis, cell survival and/or proliferation, increase in intracellular calcium, and gene transcription. CXCR4 is expressed on multiple cell types including lymphocytes, hematopoietic stem cells, endothelial and epithelial cells, and cancer cells. The CXCL12/CXCR4 axis is involved in tumor progression, angiogenesis, metastasis, and survival. This pathway is a target for therapeutics that can block the CXCL12/CXCR4 interaction or inhibit downstream intracellular signaling.

https://clincancerres.aacrjournals.org/content/clincanres/16/11/2927.full.pdf

CXCL12 (SDF-1)/CXCR4 Pathway in Cancer

Visible light photocatalytic H2 production through water splitting is of great importance for its potential application in converting solar energy into chemical energy. In this study, a novel visible-light-driven photocatalyst was designed based on photoinduced interfacial charge transfer (IFCT) through surface modification of ZnS porous nanosheets by CuS. CuS/ZnS porous nanosheet photocatalysts were prepared by a simple hydrothermal and cation exchange reaction between preformed ZnS(en)0.5 nanosheets and Cu(NO3)2. Even without a Pt cocatalyst, the as-prepared CuS/ZnS porous nanosheets reach a high H2-production rate of 4147 μmol h–1 g–1 at CuS loading content of 2 mol % and an apparent quantum efficiency of 20% at 420 nm. This high visible light photocatalytic H2-production activity is due to the IFCT from the valence band of ZnS to CuS, which causes the reduction of partial CuS to Cu2S and thus enhances H2-production activity. This work not only shows a possibility for substituting low-cost CuS for nobl...

Visible Light Photocatalytic H2-Production Activity of CuS/ZnS Porous Nanosheets Based on Photoinduced Interfacial Charge Transfer

Design and preparation of efficient artificial photosynthetic systems for harvesting solar energy by production of hydrogen from water splitting is of great importance from both theoretical and practical viewpoints. ZnS-based solid solutions have been fully proved to be an efficient visible-light driven photocatalysts, however, the H2-production rate observed for these solid solutions is far from exciting and sometimes an expensive Pt cocatalyst is still needed in order to achieve higher quantum efficiency. Here, for the first time we report the high solar photocatalytic H2-production activity over the noble metal-free reduced graphene oxide (RGO)-ZnxCd1–xS nanocomposite prepared by a facile coprecipitation-hydrothermal reduction strategy. The optimized RGO-Zn0.8Cd0.2S photocatalyst has a high H2-production rate of 1824 μmol h–1 g–1 at the RGO content of 0.25 wt % and the apparent quantum efficiency of 23.4% at 420 nm (the energy conversion efficiency is ca. 0.36% at simulated one-sun (AM 1.5G) illuminati...

/pdf/noble-metal-free-reduced-graphene-oxide-znxcd1-xs-15xgkusmxu.pdf

Noble Metal-Free Reduced Graphene Oxide-ZnxCd1–xS Nanocomposite with Enhanced Solar Photocatalytic H2-Production Performance

A series of Cu-doped ZnIn2S4 photocatalysts has been synthesized by a facile hydrothermal method, with the copper concentration varying from 0 wt% to 2.0 wt%. The physical and photophysical properties of these Cu-doped ZnIn2S4 photocatalysts were characterized by X-ray diffraction (XRD), photoluminescence spectroscopy (PL), scanning electron microscopy (SEM), and UV−visible diffuse reflectance spectroscopy (UV−vis). The diffuse reflectance and photoluminescence spectra of Cu-doped ZnIn2S4 shifted monotonically to longer wavelengths as the copper concentration increased from 0 wt% to 2.0 wt%, indicating that the optical properties of these photocatalysts greatly depended on the amount of Cu doped. Meanwhile, the layered structure of ZnIn2S4 would be destructed gradually by Cu doping. The photoactivity of ZnIn2S4 was enhanced when Cu2+ was doped into the crystal structure. The highest photocatalytic activity was observed on Cu (0.5 wt%)–doped ZnIn2S4, with the rate of hydrogen evolution to be 151.5 μmol/h u...

Enhanced Photocatalytic Hydrogen Evolution over Cu-Doped ZnIn2S4 under Visible Light Irradiation

Cetyltrimethylammoniumbromide (CTAB)-assisted hydrothermal synthesis of ZnIn2S4 as an efficient visible-light-driven photocatalyst for hydrogen production

Simulation and experimental study on the thermally induced deformations of high-speed spindle system

Detection of small metallic wear debris is critical to identify abnormal wear conditions for prognosis of pending machinery failure. In this paper we applied an inductance–capacitance (LC) resonance method to an inductive pulse debris sensor to increase the sensitivity. By adding an external capacitor to the sensing coil of the sensor, a parallel LC resonance circuit is formed that has a unique resonant frequency. At an excitation frequency close to the resonant frequency, impedance change (and thus change in voltage output) of the LC circuit caused by the passage of a debris particle is amplified due to sharp change in impedance at the resonant peak; thus signal-to-noise ratio and sensitivity are significantly improved. Using an optimized measurement circuit, iron particles ranging from 32 to 96 µm and copper particles ranging from 75 to 172 µm were tested. Results showed that the parallel LC resonance method is capable of detecting a 20 µm iron particle and a 55 µm copper particle while detection limits for the non-resonance method are 45 and 125 µm, respectively. In contrast to the non-resonant method, the sensitivity of the resonance method has been significantly improved.

https://iopscience.iop.org/article/10.1088/0957-0233/24/7/075106/pdf

Improving Sensitivity of an Inductive Pulse Sensor for Detection of Metallic Wear Debris in Lubricants Using Parallel LC Resonance Method

Extra-pancreatic metastasis is a difficult problem for surgical intervention in pancreatic cancer. CXC chemokine receptor 4 (CXCR4) was considered to have an important role in this process. We hypothesized it may contribute to the pancreatic cancer progression through influencing canonical Wnt pathway. The purpose of this study was to examine the functional role of CXCR4 in the progression of pancreatic cancers and explore the possible mechanism. To this end, the relation between CXCR4 and clinical characteristics was analysed. shRNA against CXCR4 was applied to disrupt the SDF-1/CXCR4 signal transduction pathways in pancreatic cancer cell lines. Our results showed that overall survival in the case of patients positive for CXCR4 expression was significantly lower than that in the case of patients negative for CXCR4 expression. Notably, in vitro studies we observed that the abrogation of CXCR4 could obviously influence the pancreatic cancer cell phenotype including cell proliferation, colony formation, cell invasion and also inhibit the TOPflash activity. In addition, Wnt target genes and mesenchymal markers such as Vimentin and Slug were also inhibited in CXCR4 knockdown cells. Collectively, these data reported here demonstrate CXCR4 could modulate the canonical Wnt pathway and perhaps be a promising therapeutic target for pancreatic cancer progression.

/pdf/blockade-of-sdf-1-cxcr4-signalling-inhibits-pancreatic-2pfnhb74gy.pdf

Liang Zhao

Papers

Enhanced Photocatalytic Hydrogen Evolution over Cu-Doped ZnIn2S4 under Visible Light Irradiation

Cetyltrimethylammoniumbromide (CTAB)-assisted hydrothermal synthesis of ZnIn2S4 as an efficient visible-light-driven photocatalyst for hydrogen production

Simulation and experimental study on the thermally induced deformations of high-speed spindle system

Improving Sensitivity of an Inductive Pulse Sensor for Detection of Metallic Wear Debris in Lubricants Using Parallel LC Resonance Method

Blockade of SDF-1/CXCR4 signalling inhibits pancreatic cancer progression in vitro via inactivation of canonical Wnt pathway