47 research outputs found

    Directly mapping whispering gallery modes in a microsphere through modal coupling and directional emission

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    We fabricate slightly deformed fused-silica microspheres in which whispering gallery modes possess remarkably directional escape emission from the microsphere boundary. With efficient free-space excitation and collection, the lateral spatial distribution of whispering gallery modes with different azimuthal mode numbers, m, is directly observed through modal coupling and directional emission. Excellent agreement with theory is obtained

    Artificial Proteins Designed from G3LEA Contribute to Enhancement of Oxidation Tolerance in <i>E. coli</i> in a Chaperone-like Manner

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    G3LEA is a family of proteins that exhibit chaperone-like activity when under distinct stress. In previous research, DosH was identified as a G3LEA protein from model extremophile—Deinococcus radiodurans R1 with a crucial core HD domain consisting of eight 11-mer motifs. However, the roles of motifs participating in the process of resistance to stress and their underlying mechanisms remain unclear. Here, eight different proteins with tandem repeats of the same motif were synthesized, named Motif1–8, respectively, whose function and structure were discussed. In this way, the role of each motif in the HD domain can be comprehensively analyzed, which can help in finding possibly crucial amino acid sites. Circular dichroism results showed that all proteins were intrinsically ordered in phosphate buffer, and changed into more α-helical ordered structures with the addition of trifluoroethanol and glycerol. Transformants expressing artificial proteins had significantly higher stress resistance to oxidation, desiccation, salinity and freezing compared with the control group; E. coli with Motif1 and Motif8 had more outstanding performance in particular. Moreover, enzymes and membrane protein protection viability suggested that Motif1 and Motif8 had more positive influences on various molecules, demonstrating a protective role in a chaperone-like manner. Based on these results, the artificial proteins synthesized according to the rule of 11-mer motifs have a similar function to wildtype protein. Regarding the sequence in all motifs, there are more amino acids to produce H bonds and α-helices, and more amino acids to promote interaction between proteins in Motif1 and Motif8; in addition, considering linkers, there are possibly more amino acids forming α-helix and binding substrates in these two proteins, which potentially provides some ideas for us to design potential ideal stress-response elements for synthetic biology. Therefore, the amino acid composition of the 11-mer motif and linker is likely responsible for its biological function

    The clinical application and advancement of robot-assisted McKeown minimally invasive esophagectomy for esophageal cancer

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    Robotic surgery systems, as emerging minimally invasive approaches, have been increasingly applied for the treatment of esophageal cancer because they provide a high-definition three-dimensional surgical view and mechanical rotating arms that surpass the limitations of human hands, greatly enhancing the accuracy and flexibility of surgical methods. Robot-assisted McKeown esophagectomy (RAME), a common type of robotic esophagectomy, has been gradually implemented with the aim of reducing postoperative complications, improving postoperative recovery and achieving better long-term survival. Multiple centers worldwide have reported and summarized their experiences with the RAME, and some have also discussed and analyzed its perioperative effects and survival prognosis compared with those of video-assisted minimally invasive esophagectomy. Compared to traditional surgery, the RAME has significant advantages in terms of lymph node dissection although there seems to be no difference in overall survival or disease-free survival. With the continuous advancement of technology and the development of robotic technology, further development and innovation are expected in the RAME field. This review elaborates on the prospects of the application and advancement of the RAME to provide a useful reference for clinical practice

    AZGP1 inhibits soft tissue sarcoma cells invasion and migration

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    Abstract Background One of the major challenges in soft tissue sarcomas is to identify factors that predict metastasis. AZGP1 is a potential biomarker of cancer progression, but its value in soft tissue sarcomas remains unknown. The aim of this study is to determine the expression level of AZGP1 in soft tissue sarcomas, and to analyze its influence on tumor progression. Methods AZGP1 immunohistochemistry (IHC) and RT-PCR were performed in 86 patients with soft tissue sarcomas. The relationships between AZGP1 levels and clinicopathologic features were analyzed. In vitro experiments were performed using fibrosarcoma (HT1080), rhabdomyosarcoma (RD) and synovial sarcoma (SW982) cell lines to corroborate our findings. We used lentiviral over-expression and knockdown assays to examine how changes of AZGP1 expressions might affect cellular migration and invasion. Results The quantitative RT-PCR results showed that AZGP1 expression was negatively correlated with metastasis and overall survival in soft tissue sarcomas (p < 0.05). Immunohistochemical staining showed lower expression of AZGP1 in patients with metastasis than in those without. Kaplan-Meier survival analysis showed that patients with low expression of AZGP1 had shorter overall (p = 0.056) and metastasis-free survivals (p = 0.038). These findings were corroborated by our in vitro experiments. Over-expression of AZGP1 significantly decreased RD cellular migration and invasion by 64% and 78%, respectively. HT1080 cells migration was inhibited by 2-fold, whereas their invasion was repressed by 7-fold after AZGP1 knockdown. Conclusions Our study reveals that reduced AZGP1 expression correlates with in vitro cellular migration and invasion. In vivo, it is associated with higher metastatic risk and shorter survival in patients with soft tissue sarcomas

    Copper phosphide decorated g-C₃N₄ catalysts for highly efficient photocatalytic H₂ evolution

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    Designing functional heterojunctions to enhance photocatalytic hydrogen evolution is still a key challenge in the field of efficient solar energy utilization. Copper phosphides become an ideal material to serve as the cocatalysts during photocatalytic hydrogen evolution by virtue of the lower prices. In this study, we synthesized graphitic carbon nitride (g-C3N4) based catalysts loaded with copper phosphide (Cu3P, Cu97P3), which exhibit superior performance in photocatalytic H2 evolution. Ultraviolet (UV)-visible spectroscopy illustrated that the absorption of light strengthened after the loading of copper phosphide, and the time-resolved transient photoluminescence (PL) spectra showed that the separation and transfer of the photoexcited carriers greatly improved. Moreover, both copper phosphide/g-C3N4 photocatalysts exhibited a relatively high H2 evolution rate: Cu3P/g-C3N4 (maximum 343 μmol h-1 g-1), Cu97P3/g-C3N4 (162.9 μmol h-1 g-1) while copper phosphide themself exhibit no photocatalytic activity. Thus, the copper phosphides (Cu3P, Cu97P3) work as a cocatalyst during photocatalytic H2 evolution. The cycling experiments illustrated that both copper phosphide/g-C3N4 photocatalysts perform excellent stability in the photocatalytic H2 evolution. It is worth noting that while the NaH2PO2 was heated in the tube furnace for phosphorization to obtain Cu3P, the excessive PH3 could pass through the solution of CuSO4 to obtain Cu97P3 at the same time, which significantly improved the utilization of PH3 and reduced the risk of toxicity. This work could provide new strategies to design photocatalysts decorated with copper phosphide for highly efficient visible-light-driven hydrogen evolution.This work was financially supported by the National Natural Science Foundation of China (Grant No. 52103339), Natural Science Foundation of Hubei Province (Grant No. 2018CFB282) and Science Foundation of Hubei University of Technology (Grant No. BSQD2017065)
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