Shandong Normal University

About: Shandong Normal University is a education organization based out in Jinan, Shandong, China. It is known for research contribution in the topics: Laser & Catalysis. The organization has 12378 authors who have published 12576 publications receiving 174572 citations.

Homochiral Covalent Organic Framework for Catalytic Asymmetric Synthesis of a Drug Intermediate.

Abstract: (S)-2-(2-Chlorophenyl)-2-(6,7-dihydrothieno[3,2-c]pyridin-5(4H)-yl)acetonitrile ((S)-CIK) is a key intermediate in the synthesis of (S)-clopidogrel, which is one of the most saleable worldwide antiplatelet and antithrombotic drugs. We show herein a facile method for the direct synthesis of (S)-CIK via Strecker reaction using a homochiral covalent framework catalyst in a heterogeneous way. The asymmetric synthesis involves a photothermal-conversion-triggered, thermally driven reaction which affords (S)-CIK in 98% yield with 94% enantiomeric excess under visible-light irradiation. Furthermore, the above approach is readily extended to a gram-scale level on a fixed-bed continuous-flow model reactor. The potential utility of this strategy is highlighted by the preparation of many more other types of chiral drugs and drug intermediates in a green and facile way.

Induced expression of AtLEC1 and AtLEC2 differentially promotes somatic embryogenesis in transgenic tobacco plants.

Abstract: Arabidopsis LEAFY COTYLEDON (LEC) genes, AtLEC1 and AtLEC2, are important embryonic regulators that play key roles in morphogenesis and maturation phases during embryo development. Ectopic expression of AtLEC1 and AtLEC2 in tobacco caused abnormality in transgenic seedling. When transgenic seeds germinated on medium containing 30 µM DEX, LEC1 transgenic seedlings were ivory and fleshy, with unexpanded cotyledons, stubby hypocotyls, short roots and no obvious callus formation at the shoot meristem position. While LEC2 transgenic seedlings formed embryonic callus on the shoot apical meristem and somatic embryo-like structures emerged from the surface of the callus. When callus were transferred to hormone free MS0 medium more shoots were regenerated from each callus. However, shoot formation was not observed in LEC1 overexpressors. To investigate the mechanisms of LEC2 in somatic embryogenesis, we studied global gene expression by digital gene expression profiling analysis. The results indicated that ectopic expression of LEC2 genes induced accumulation of embryo-specific proteins such as seed storage proteins, late embryogenesis abundant (LEA) proteins, fatty acid biosynthetic enzymes, products of steroid biosynthesis related genes and key regulatory genes of the embryo development. Genes of plant-specific transcription factors such as NAC domain protein, AP2 and GRAS family, resistance-related as well as salicylic acid signaling related genes were up-regulated in LEC2 transgenic seedlings. Ectopi c expression of LEC2 induced large number of somatic embryo formation and shoot regeneration but 20 d DEX induction of LEC1 is not sufficient to induce somatic embryogenesis and shoot formation. Our data provide new information to understand the mechanisms on LEC2 gene’s induction of somatic embryogenesis.

Sensing telomerase: From in vitro detection to in vivo imaging

Abstract: Telomerase is a ribonucleoprotein reverse transcriptase that is responsible for maintaining the telomere length in cells. Telomerase overexpresses in almost all malignant tumor cells, and it has become a promising biomarker and a potential therapy target for cancers. Consequently, accurate and efficient quantification of the telomerase is highly essential to medical diagnostics and therapeutics. Recently, a series of novel telomerase detection methods with excellent performance have been developed, but a overview of in vivo telomerase detection methods is lacking. In this Minireview, we summarize the emerging strategies for telomerase assays in the last five years, including both in vitro assays and in vivo imaging methods, and discuss their future directions as well.

A Biomass-Derived Carbon-Based Electrocatalyst for Efficient N2 Fixation to NH3 under Ambient Conditions

Abstract: Currently, NH3 production primarily depends on the Haber-Bosch process, which operates at elevated temperatures and pressures and leads to serious CO2 emissions. Electrocatalytic N2 reduction offers an environmentally benign approach for the sustainable synthesis of NH3 under ambient conditions. This work reports the development of biomass-derived amorphous oxygen-doped carbon nanosheet (O-CN) using tannin as the precursor. As a metal-free electrocatalyst for N2 -to-NH3 conversion, such O-CN shows high catalytic performances, achieving a large NH3 yield of 20.15 μg h-1 mg-1 cat. and a high Faradic efficiency of 4.97 % at -0.6 V vs. reversible hydrogen electrode (RHE) in 0.1 m HCl at ambient conditions. Remarkably, it also exhibits high electrochemical selectivity and durability.

Formation of Enhanced Uniform Chiral Fields in Symmetric Dimer Nanostructures.

Abstract: Chiral fields with large optical chirality are very important in chiral molecules analysis, sensing and other measurements. Plasmonic nanostructures have been proposed to realize such super chiral fields for enhancing weak chiral signals. However, most of them cannot provide uniform chiral near-fields close to the structures, which makes these nanostructures not so efficient for applications. Plasmonic helical nanostructures and blocked squares have been proved to provide uniform chiral near-fields, but structure fabrication is a challenge. In this paper, we show that very simple plasmonic dimer structures can provide uniform chiral fields in the gaps with large enhancement of both near electric fields and chiral fields under linearly polarized light illumination with polarization off the dimer axis at dipole resonance. An analytical dipole model is utilized to explain this behavior theoretically. 30 times of volume averaged chiral field enhancement is gotten in the whole gap. Chiral fields with opposite handedness can be obtained simply by changing the polarization to the other side of the dimer axis. It is especially useful in Raman optical activity measurement and chiral sensing of small quantity of chiral molecule.