| 1. |
- Chi, Chaodan, et al.
(författare)
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Si-based InGaAs photodetectors on heterogeneous integrated substrate
- 2021
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Ingår i: Science China: Physics, Mechanics and Astronomy. - : Springer Science and Business Media LLC. - 1674-7348 .- 1869-1927. ; 64:6
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, InGaAs p-i-n photodetectors (PDs) on an InP/SiO2/Si (InPOI) substrate fabricated by ion-slicing technology are demonstrated and compared with the identical device on a commercial InP substrate. The quality of epitaxial layers on the InPOI substrate is similar to that on the InP substrate. The photo responsivities of both devices measured at 1.55 µm are comparable, which are about 0.808–0.828 A W−1. Although the dark current of PD on the InPOI substrate is twice as high as that of PD on the InP substrate at 300 K, the peak detectivities of both PDs are comparable. In general, the overall performance of the InPOI-based PD is comparable to the InP-based PD, demonstrating that the ion-slicing technology is a promising route to enable the high-quality Si-based InP platform for the full photonic integration on a Si substrate.
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| 2. |
- Zhang, Jiao, et al.
(författare)
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Wnt inhibitory factor-1 functions as a tumor suppressor through modulating Wnt/β-catenin signaling in neuroblastoma
- 2014
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Ingår i: Cancer Letters. - : Elsevier. - 0304-3835 .- 1872-7980. ; 348:1–2, s. 12-19
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Tidskriftsartikel (refereegranskat)abstract
- Neuroblastoma is the most common extracranial solid tumor in childhood and is associated with serious morbidity and mortality. The effective treatment of neuroblastoma remains one of the major challenges in pediatric oncology. The Wnt signaling pathway has been shown to play a significant role in the pathogenesis of adult and pediatric tumors. WIF-1 has been identified as an important Wnt antagonist which inhibits Wnt/β-catenin signaling by directly binding to Wnt proteins. However, the expression and function of WIF-1 in neuroblastoma remains unknown. The present study showed that WIF-1 was downregulated with high level promoter methylation in neuroblastoma cells, and was significantly upregulated after exposure to demethylating agent. This finding suggests that downregulation of WIF-1 was associated with its promoter methylation in neuroblastoma. To further study the potential function of WIF-1 in neuroblastoma, we constructed a plasmid that over-expressed WIF-1 and transfected the plasmid into one neuroblastoma cell line SK-N-SH. We found that restoration of WIF-1 inhibited the growth and proliferation of neuroblastoma cells in vitro. Morever, Wnt/β-catenin signaling activity and target genes expression were reduced by WIF-1 restoration. These results provide support that WIF-1 is downregulated and functions as a tumor suppressor by antagonizing Wnt/β-catenin signaling in neuroblastoma, suggesting a potential role as a therapeutic target in neuroblastoma.
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| 3. |
- Huang, Wei, et al.
(författare)
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Substrate Promiscuity, Crystal Structure, and Application of a Plant UDP-Glycosyltransferase UGT74AN3
- 2024
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Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 14:1, s. 475-488
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Tidskriftsartikel (refereegranskat)abstract
- Glycosyltransferases are effective enzymes for glycosylating natural products (NPs), and some of them have the unusual property of being exceedingly promiscuous catalytically toward a range of substrates. UGT74AN3 is a plant glycosyltransferase identified from Catharanthus roseus in our previous work. In this study, we found that UGT74AN3 exhibits high substrate promiscuity toward 78 acceptors and 6 sugar donors and also exhibits N-/S-glycosylation activity toward simple aromatic compounds. The crystal structures of UGT74AN3 in the complex with various NPs were solved. Sugar donor recognition of UGT74AN3 was altered by structure-based mutagenesis, and the T145V mutant shifted its sugar donor preference from UDP-Glc to UDP-Xyl. Structural analysis reveals that a spacious U-shaped hydrophobic binding pocket accounts for the high substrate promiscuity of UGT74AN3. The residues E85 and F193 might serve as gatekeepers of UGT74AN3 to control substrate binding. In addition, a rare substrate binding mode was discovered in the structure of UGT74AN3, and the process of substrate flipping in the pocket was charted by molecular dynamics simulations. Moreover, a cost-effective one-pot system by coupling UGT74AN3 with AtSuSy, a sucrose synthase, was established for in situ generating and recycling UDP-Glc from sucrose and UDP to glycosylate NPs. Our study reveals the structural basis underlying the substrate promiscuity of UGT74AN3 and provides an efficient and economical enzymatic synthesis strategy for producing valuable glycosides for drug discovery.
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| 4. |
- Lin, Jiajie, et al.
(författare)
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Wafer-scale heterogeneous integration InP on trenched Si with a bubble-free interface
- 2020
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Ingår i: APL Materials. - : AIP Publishing. - 2166-532X. ; 8:5
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Tidskriftsartikel (refereegranskat)abstract
- Heterogeneous integration of compound semiconductors on a Si platform leads to advanced device applications in the field of Si photonics and high frequency electronics. However, the unavoidable bubbles formed at the bonding interface are detrimental for achieving a high yield of dissimilar semiconductor integration by the direct wafer bonding technology. In this work, lateral outgassing surface trenches (LOTs) are introduced to efficiently inhibit the bubbles. It is found that the chemical reactions in InP-Si bonding are similar to those in Si-Si bonding, and the generated gas can escape via the LOTs. The outgassing efficiency is dominated by LOTs' spacing, and moreover, the relationship between bubble formation and the LOT's structure is well described by a thermodynamic model. With the method explored in this work, a 2-in. bubble-free crystalline InP thin film integrated on the Si substrate with LOTs is obtained by the ion-slicing and wafer bonding technology. The quantum well active region grown on this Si-based InP film shows a superior photoemission efficiency, and it is found to be 65% as compared to its bulk counterpart.
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| 5. |
- Zhang, Qiong, et al.
(författare)
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NIR-region two-photon fluorescent probes for Fe3+/Cu2+ ions based on pyrimidine derivatives with different flexible chain
- 2016
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Ingår i: Sensors and actuators. B, Chemical. - : ELSEVIER SCIENCE SA. - 0925-4005 .- 1873-3077. ; 222, s. 574-578
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Tidskriftsartikel (refereegranskat)abstract
- Two novel NIR-region two-photon fluorescent probes CCP and COP, show strong fluorescence quenching and good ratiometric responses toward Fe3+ and Cu2+, respectively; and their two-photon fluorescence are reversible by the subsequent addition of EDTA. CCP and COP are valuable candidates for two-photon imaging in the biological transparency window. (C) 2015 Elsevier B.V. All rights reserved.
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