Catalytic enantioselective synthesis of α-chiral azides

Ding, Pei-Gang,Hu, Xiao-Si,Zhou, Feng,Zhou, Jian The Royal Society of Chemistry 2018 ORGANIC CHEMISTRY FRONTIERS Vol.5 No.9

<P>α-Chiral azides represent a special subclass of chiral amines, which not only widely exist in bioactive compounds but also play a significant role as a building block in a variety of value-added chiral products. The catalytic asymmetric synthesis of α-chiral azides is of current interest and three synthetic strategies have been developed. This review summarizes the recent progress in this research area, discusses the advantages and limitations of each strategy, and outlines synthetic opportunities for future research.</P>

ppGalNAc T1 as a Potential Novel Marker for Human Bladder Cancer

Ding, Ming-Xia,Wang, Hai-Feng,Wang, Jian-Song,Zhan, Hui,Zuo, Yi-Gang,Yang, De-Lin,Liu, Jing-Yu,Wang, Wei,Ke, Chang-Xing,Yan, Ru-Ping Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

Objectives: To investigate the effect of glycopeptide-preferring polypeptide GalNAc transferase 1 (ppGalNAc T1 ) targeted RNA interference (RNAi) on the growth and migration of human bladder carcinoma EJ cells in vitro and in vivo. Methods: DNA microarray assays were performed to determine ppGalNAc Ts(ppGalNAc T1-9) expression in human bladder cancer and normal bladder tissues. We transfected the EJ bladder cancer cell line with well-designed ppGalNAc T1 siRNA. Boyden chamber and Wound healing assays were used to investigate changes of shppGalNAc T1-EJ cell migration. Proliferation of shppGalNAc T1-EJ cells in vitro was assessed using [3H]-thymidine incorporation assay and soft agar colony formation assays. Subcutaneous bladder tumors in BALB/c nude mice were induced by inoculation of shppGalNAc T1-EJ cells and after inoculation diameters of tumors were measured every 5 days to determine gross tumor volumes. Results: ppGalNAc T1 mRNA in bladder cancer tissues was 11.2-fold higher than in normal bladder tissues. When ppGalNAc T1 expression in EJ cells was knocked down through transfection by pSUPER-shppGalNAc T1 vector, markedly reduced incorporation of [3H]-thymidine into DNA of EJ cells was observed at all time points compared with the empty vector transfected control cells. However, ppGalNAc T1 knockdown did not significantly inhibited cell migration (only 12.3%). Silenced ppGalNAc T1 expression significantly inhibited subcutaneous tumor growth compared with the control groups injected with empty vector transfected control cells. At the end of observation course (40 days), the inhibitory rate of cancerous growth for ppGalNAc T1 knockdown was 52.5%. Conclusion: ppGalNAc T1 might be a potential novel marker for human bladder cancer. Although ppGalNAc T1 knockdown caused no remarkable change in cell migration, silenced expression significantly inhibited proliferation and tumor growth of the bladder cancer EJ cell line.

Helicobacter pylori Chaperone-Like Protein CagT Plays an Essential Role in the Translocation of CagA into Host Cells

( Ding Hong Lei ),( Hao Zeng ),( Lin Ping Huang ),( Yan Dong Dong ),( Yi Jun Duan ),( Xu Hu Mao ),( Gang Guo ),( Quan Ming Zou ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.10

Most of the Helicobacter pylori strains containing the cag pathogenicity island (PAI) have been associated with more severe gastric disease in infected humans. The cag PAI is composed of 27 proteins, and some of the components are required for CagA translocation into host cells as well as induction of proinflammatory cytokines, such as interleukin-8 (IL-8); however, the exact function of most of the components remains unknown or poorly characterized. In this study, we demonstrated that CagT (HP0532), which is an essential structural component of the cag PAI apparatus, plays an important role in the translocation of CagA into host epithelial cells. In addition to being located on the bacterial surface, CagT is also partially localized in the inner membrane, where it acts as a chaperone-like protein and promotes CagA translocation. However, CagT secretion was not detected by immunoprecipitation analysis of cell culture supernatants. Meanwhile, CagT was related to the introduction of IL-8 of the host cell. These results suggest that CagT is expressed on both the inner and outer bacterial membranes, where it serves as a unique type IV secretion system component that is involved in CagA secretion and cag PAI apparatus assembly.

Prediction methods on tunnel-excavation induced surface settlement around adjacent building

Ding, Zhi,Wei, Xin-jiang,Wei, Gang Techno-Press 2017 Geomechanics & engineering Vol.12 No.2

With the rapid development of urban underground traffic, the study of soil deformation induced by subway tunnel construction and its settlement prediction are gradually of general concern in engineering circles. The law of soil displacement caused by shield tunnel construction of adjacent buildings is analyzed in this paper. The author holds that ground surface settlement based on the Gauss curve or Peck formula induced by tunnel excavation of adjacent buildings is not reasonable. Integrating existing research accomplishments, the paper proposed that surface settlement presents cork distribution curve characters, skewed distribution curve characteristics and normal distribution curve characteristics when the tunnel is respectively under buildings, within the scope of the disturbance and outside the scope of the disturbance. Calculation formulas and parameters on cork distribution curve and skewed distribution curve were put forward. The numerical simulation, experimental comparison and model test analysis show that it is reasonable for surface settlement to present cork distribution curve characters, skewed distribution curve characteristics and normal distribution curve characteristics within a certain range. The research findings can be used to make effective prediction of ground surface settlement caused by tunnel construction of adjacent buildings, and to provide theoretical guidance for the design and shield tunnelling.

Pressure-Induced Confined Metal from the Mott InsulatorSr3Ir2O7

Ding, Yang,Yang, Liuxiang,Chen, Cheng-Chien,Kim, Heung-Sik,Han, Myung Joon,Luo, Wei,Feng, Zhenxing,Upton, Mary,Casa, Diego,Kim, Jungho,Gog, Thomas,Zeng, Zhidan,Cao, Gang,Mao, Ho-kwang,van Veenendaal, American Physical Society 2016 Physical Review Letters Vol.116 No.21

<P>The spin-orbit Mott insulator Sr3Ir2O7 provides a fascinating playground to explore insulator-metal transition driven by intertwined charge, spin, and lattice degrees of freedom. Here, we report high-pressure electric resistance and resonant inelastic x-ray scattering measurements on single-crystal Sr3Ir2O7 up to 63-65 GPa at 300 K. The material becomes a confined metal at 59.5 GPa, showing metallicity in the ab plane but an insulating behavior along the c axis. Such an unusual phenomenon resembles the strange metal phase in cuprate superconductors. Since there is no sign of the collapse of spin-orbit or Coulomb interactions in x-ray measurements, this novel insulator-metal transition is potentially driven by a first-order structural change at nearby pressures. Our discovery points to a new approach for synthesizing functional materials.</P>

Study on sloshing simulation in the independent tank for an ice-breaking LNG carrier

Ding, Shifeng,Wang, Gang,Luo, Qiuming The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.-

As the LNG carrier operates in ice covered waters, it is key to ensure the overall safety, which is related to the coupling effect of ice-breaking process and internal liquid sloshing. This paper focuses on the sloshing simulation of the ice-breaking LNG carrier, and the numerical method is proposed using Circumferential Crack Method (CCM) and Volume of Vluid (VOF) with two main key factors (velocity νx and force Fx). The ship motion analysis is carried out by CCM when the ship navigates in the ice-covered waters with a constant propulsion power. The velocity νx is gained, which is the initial excitation condition for the calculation of internal sloshing force Fx. Then, the ship motion is modified based on iterative computations under the union action of ice-breaking force and liquid sloshing load. The sloshing simulation under the LNG tank is studied with the modified ship motion. Moreover, an ice-breaking LNG ship with three-leaf type tank is used for case study. The internal LNG sloshing is simulated with three different liquid heights, including free surface shape and sloshing pressure distribution at a given moment, pressure curves at monitoring points on the bulkhead. This present method is effective to solve the sloshing simulation during ice-breaking process, which could be a good reference for the design of the polar ice-breaking LNG carrier.

The pore-forming subunit Kir6.1 of the K-ATP channel negatively regulates the NLRP3 inflammasome to control insulin resistance by interacting with NLRP3

Gang Hu,Ren-Hong Du,Ming Lu,Cong Wang,Jian-Hua Ding,Guangyu Wu 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Excessive activation of the NLRP3 inflammasome is a key component contributing to the pathogenesis of various inflammatory diseases. However, the molecular mechanisms underlying its activation and regulation remain poorly defined. The objective of this study was to explore the possible function of the K+ channel pore-forming subunit Kir6.1 in regulating NLRP3 inflammasome activation and insulin resistance. Here, we demonstrate that Kir6.1 depletion markedly activates the NLRP3 inflammasome, whereas enhanced Kir6.1 expression produces opposing effects both in mice in vivo and in primary cells in vitro. We also demonstrate that Kir6.1 controls insulin resistance by inhibiting NLRP3 inflammasome activation in mice. We further show that Kir6.1 physically associates with NLRP3 and thus inhibits the interactions between the NLRP3 inflammasome subunits. Our results reveal a previously unrecognized function of Kir6.1 as a negative regulator of the NLRP3 inflammasome and insulin resistance, which is mediated by virtue of its ability to inhibit NLRP3 inflammasome assembly. These data provide novel insights into the regulatory mechanism of NLRP3 inflammasome activation and suggest that Kir6.1 is a promising therapeutic target for inflammasome-mediated inflammatory diseases.

Microstructure evolution and effect on deuterium retention in oxide dispersion strengthened tungsten during He⁺ irradiation

Ding, Xiao-Yu,Xu, Qiu,Zhu, Xiao-yong,Luo, Lai-Ma,Huang, Jian-Jun,Yu, Bin,Gao, Xiang,Li, Jian-Gang,Wu, Yu-Cheng Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.12

Oxide dispersion-strengthened materials W-1wt%Pr₂O₃ and W-1wt%La₂O₃ were synthesized by wet chemical method and spark plasma sintering. The field emission scanning electron microscopy (FE-SEM) analysis, XRD and Vickers microhardness measurements were conducted to characterize the samples. The irradiations were carried out with a 5 keV helium ion beam to fluences up to 5.0 × 10²¹ ions/m² under 600 ℃ using the low-energy ion irradiation system. Transmission electron microscopy (TEM) study was performed to investigate the microstructural evolution in W-1wt%Pr₂O₃ and W-1wt%La₂O₃. At 1.0 × 10²⁰ He⁺/m², the average loops size of the W-1wt%Pr₂O₃ was 4.3 nm, much lower than W-1wt% La₂O₃ of 8.5 nm. However, helium bubbles were not observed throughout in both doped W materials. The effects of pre-irradiation with 1.0 × 10²¹ He⁺/m² on trapping of injected deuterium in doped W was studied by thermal desorption spectrometry (TDS) technique using quadrupole mass spectrometer. Compared with the samples without He⁺ pre-irradiation, deuterium (D) retention of doped W materials increased after He⁺ irradiation, whose retention was unsaturated at the damage level of 1.0 × 10²²D₂⁺/m². The present results implied that irradiation effect of He⁺ ions must be taken into account to evaluate the deuterium retention in fusion material applications.

Study on sloshing simulation in the independent tank for an ice-breaking LNG carrier

Ding, Shifeng,Wang, Gang,Luo, Qiuming The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.1

As the LNG carrier operates in ice covered waters, it is key to ensure the overall safety, which is related to the coupling effect of ice-breaking process and internal liquid sloshing. This paper focuses on the sloshing simulation of the ice-breaking LNG carrier, and the numerical method is proposed using Circumferential Crack Method (CCM) and Volume of Vluid (VOF) with two main key factors (velocity νx and force Fx). The ship motion analysis is carried out by CCM when the ship navigates in the ice-covered waters with a constant propulsion power. The velocity νx is gained, which is the initial excitation condition for the calculation of internal sloshing force Fx. Then, the ship motion is modified based on iterative computations under the union action of ice-breaking force and liquid sloshing load. The sloshing simulation under the LNG tank is studied with the modified ship motion. Moreover, an ice-breaking LNG ship with three-leaf type tank is used for case study. The internal LNG sloshing is simulated with three different liquid heights, including free surface shape and sloshing pressure distribution at a given moment, pressure curves at monitoring points on the bulkhead. This present method is effective to solve the sloshing simulation during ice-breaking process, which could be a good reference for the design of the polar ice-breaking LNG carrier.

Serum lipocalin-2 is a potential biomarker for the clinical diagnosis of nonalcoholic steatohepatitis

( Gang Xu ),( Yu-min Wang ),( Miao-miao Ying ),( Sui-dan Chen ),( Zong-rui Li ),( Hong-lei Ma ),( Ming-hua Zheng ),( Jian Wu ),( Chunming Ding ) 대한간학회 2021 Clinical and Molecular Hepatology(대한간학회지) Vol.27 No.2

Background/Aims: Nonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease (NAFLD) characterized by hepatic steatosis, inflammation, hepatocellular injury, and fibrosis. We aimed to investigate the usefulness of a key biomarker, lipocalin-2 (LCN2), for the detection of NASH progression. Methods: A mouse NASH model was established using a high-fat diet and a high-sugar drinking water. Gene expression profile of the NASH model was analyzed using RNA sequencing. Moreover, 360 NAFLD patients (steatosis, 83; NASH, 277), 40 healthy individuals, and 87 patients with alcoholic fatty liver disease were recruited. Results: Inflammatory infiltration, focal necrosis in the leaflets, steatosis, and fibrosis were documented in the mouse liver. In total, 504 genes were differentially expressed in the livers of NASH mice, and showed significant functional enrichment in the inflammation-related category. Upregulated liver LCN2 was found to be significantly interactive with various interleukins and toll-like receptors. Serum LCN2 levels were significantly increased in NAFLD patients. Serum LCN2 levels were correlated with steatosis, intralobular inflammation, semiquantitative fibrosis score, and nonalcoholic fatty liver disease activity score. The area under the curve of serum LCN2 was 0.987 with a specificity of 100% and a sensitivity of 93.5% for NASH diagnosis, and 0.977 with almost the same specificity and sensitivity for steatosis. Conclusions: LCN2 might be involved in the transition from NAFL to NASH by mediating inflammation. Serum LCN2 levels might be a novel biomarker for the diagnosis of NASH. (Clin Mol Hepatol 2021;27:329-345)