Inorganic–Organic Hybrid Molecular Clusters with Cu2I2 Rhomboid Dimer Core as Light-Emitting Coating Materials

Journal of Cluster Science - In this paper, a series of light-emitting copper(I) iodide inorganic–organic hybrid clusters has been synthesized, and they are 0D-Cu2I2(fmp)4 (1,...     

Microstructure performance and formation mechanism of laser alloying rare earth oxides modified nanocrystalline layer on TA7

Nanoscale particles (NP) were observed in a Ni60–Ag–Si₃N₄–Y₂O₃ laser alloying (LA) layer on a TA7 titanium alloy, NP usually locate on the grain boundaries, which are able to block the motion of dislocation in a certain extent. Such layer mainly consisted of γ-Ni, TiN, γ-(Fe, Ni), TiAg and lots of amorphous phases. The wear resistance of such layer with laser scanning speed 3 mm/s was better than that of a LA layer with 6 mm/s, which was mainly ascribed to an uniform microstructure and less defect of layer. The high laser scanning speed made the existing time of laser molten pool be shorter than before, favoring the formation of a fine microstructure. However, the defects, such as pores were produced in LA layer (higher scanning speed), decreasing the wear resistance.     

Characterization of Laves phase in Crofer 22 H stainless steel

This study investigated the effect of annealing temperature on the precipitation behavior of Crofer^® 22 H at 600 °C, 700 °C, and 800 °C. The grain size distribution, precipitate phase identification, and microstructure were analyzed using electron backscatter diffraction (EBSD) and energy dispersive X-ray spectroscopy (EDS). The morphology of Laves phase (Fe,Cr,Si)₂(Nb,W) precipitates having the Cr₂Nb structure changed from strip-like to needle-shaped as the annealing temperature was increased. The precipitates of the Laves phase also shifted from the grain boundaries to the grain interiors when the temperature was increased. However, the average grain size (150 μm) of the ferritic matrix did not significantly change at 600 °C, 700 °C, and 800 °C for 10 h.     

Performance improvement of amorphous indium–gallium–zinc oxide ReRAM with SiO2 inserting layer

In this study, the resistive switching performance of amorphous indium–gallium–zinc oxide (a-IGZO) resistive switching random-access memory (ReRAM) was improved by inserting a thin silicon oxide layer between silver (Ag) top electrode and a-IGZO resistive switching layer. Compared with the single a-IGZO layer structure, the SiO₂/a-IGZO bi-layer structure exhibits the higher On/Off resistance ratio larger than 10³, and the lower operation power using a smaller SET compliance current. In addition, good endurance and excellent retention characteristics were achieved. Furthermore, multilevel resistance states are obtained through adjusting SET compliance current and RESET stop voltage, which shows a promise for high-performance nonvolatile multilevel memory application.     

Ultrasensitive,Rapid, and Selective Detection of Mercury Using Graphene Assisted Laser Desorption/Ionization Mass Spectrometry

We report an extremely sensitive and specific detection of mercuric ions (Hg²⁺) based on graphene assisted laser desorption/ionization mass spectrometry (GALDI-MS). Combining the highly selective coordination interactions between thymine (T) and Hg²⁺, we present a simple, effective, and novel approach, based on π–π interactions of the T-Hg²⁺-T complex and G that can serve as a platform and matrix for GALDI-MS. The present sensor not only exhibits high selectivity and sensitivity (picomolar) to Hg²⁺ in aqueous solution, but also can elucidate the chemical structures of the metal complexes. The significant advantage in the current approach is that there is no need for a sophisticated instrument, and no sample pretreatment is required to detect the Hg²⁺ ions.

黄油中8种类固醇激素的液相色谱/串联质谱检测

建立了黄油中雌酮、α-雌二醇、β-雌二醇、雌三醇、睾酮、表睾酮、孕酮和丙酸睾酮8种类固醇激素的凝胶渗透色谱(GPC)-液相色谱/串联质谱(LC-MS/MS)检测方法。样品用乙酸乙酯-环己烷(1∶1,V/V)提取,提取液经GPC柱净化除脂,GPC浓缩液采用C18色谱柱(100 mm×2.0 mm i.d.,3.0μm)分离,以乙腈和水为流动相进行梯度洗脱,电喷雾电离多反应监测模式进行定性和定量分析。8种类固醇激素以基质匹配外标法定量,药物在1.0~20.0μg/kg线性范围内相关系数(r)均大于0.999;方法检出限(S/N=3)为0.04~0.30μg/kg,定量限LOQs(S/N=10)为1.0μg/kg;添加水平为1.0,2.0,4.0μg/kg时,回收率范围在64.1%~110%之间;相对标准偏差(RSD)小于11%。结果表明,本方法准确、可靠,满足黄油中8种类固醇激素的检测分析要求。     

Nephrotoxicity assessments of benzo(a)pyrene during zebrafish embryogenesis

Benzo(a)pyrene is a chemical produced during the process of making fried, roasted, and smoked foods. It remains unclear whether benzo(a)pyrene affects the early development of human organs. In this study, we used the transgenic zebrafish line Tg(wt1b:GFP) as a model to assess benzo(a)pyrene-induced kidney malformation. By soaking zebrafish embryos in benzo(a)pyrene at various doses (2, 20, and 200 ppb), only a minor effect on the survival rate was detected (0 ppb: 97.8 ± 1.9 %; 2–200 ppb: 89.1 ± 5.8–91.5 ± 8.3 %). However, benzo(a)pyrene significantly affected the development of the kidney (malformation rates ranges from 50.0 ± 3.5 to 77.4 ± 5.3 %). Various abnormalities, such as unusual curving of pronephric tubes, swollen glomerulus, and incomplete development of pronephric ducts, were observed. This study provides a rapid and effective protocol for the evaluation of the notable effects of benzo(a)pyrene on embryonic kidney development.     

Rational Design of Cyclometalated Iridium(III) Complexes for Three-Photon Phosphorescence Bioimaging

Compared to 2PE (two-photon excitation) microscopy, 3PE microscopy has superior spatial resolution, deeper tissue penetration, and less defocused interference. The design of suitable agents with a large Stokes shift, good three-photon absorption (3PA), subcellular targeting, and fluorescence lifetime imaging (FLIM) properties, is challenging. Now, two Ir^III complexes (3PAIr1 and 3PAIr2) were developed as efficient three-photon phosphorescence (3PP) agents. Calculations reveal that the introduction of a new group to the molecular scaffold confers a quadruple promotion in three-photon transition probability. Confocal and lifetime imaging of mitochondria using Ir^III complexes as 3PP agents is shown. The complexes exhibit low working concentration (50 nm ), fast uptake (5 min), and low threshold for three-photon excitation power (0.5 mW at 980 nm). The impressive tissue penetration depth (ca. 450 μm) allowed the 3D imaging and reconstruction of brain vasculature from a living specimen.     

Ruthenium(II)-Catalyzed Asymmetric Inert C−H Bond Activation Assisted by a Chiral Transient Directing Group

A ruthenium(II)-catalyzed asymmetric intramolecular hydroarylation assisted by a chiral transient directing group has been developed. A series of 2,3-dihydrobenzofurans bearing chiral all-carbon quaternary stereocenters have been prepared in remarkably high yields (up to 98 %) and enantioselectivities (up to >99 % ee). By this methodology, a novel asymmetric total synthesis of CB2 receptor agonist MDA7 has been successfully developed.