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  • Frontiers Media SA  (3)
  • 1
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    Online Resource
    Table3.XLS
    Frontiers Media SA ; 2023
    In:  Frontiers in Earth Science Vol. 11 ( 2023-8-10)
    Details
    In: Frontiers in Earth Science, Frontiers Media SA, Vol. 11 ( 2023-8-10)
    Abstract: The Jiaodong Peninsula is China’s largest gold province and the third largest in the world. Although gold mineralization is associated with Mesozoic granites temporally and spatially, the specific genetic association remains unclear, leading to ambiguity regarding the genetic type of gold deposits. To address this issue, we conducted whole-rock major and trace elements, LA–ICP–MS zircon U–Pb geochronology and trace elements geochemical analyses on the Linglong (Linglong suite), Yashan, and Nansu (Weideshan suite) plutons, and compiled contemporaneous magmatic rock data. Our results show that the granites were emplaced at 161 ± 2, 118 ± 1, and 121 ± 2 Ma, respectively. Geochemically, these rocks exhibit high Al 2 O 3 (12.73–14.10 wt%) content and Sr/Y (35.54–136.50) ratio, and low Y (3.26–11.20 ppm) and Yb (0.33–0.97 ppm) contents, indicating the adakitic rock properties. They were formed through partial melting of the thickened lower crust associated with subduction of the paleo-Pacific Plate. The Early Cretaceous granites contain a large amount of mafic microgranular enclaves, indicating the presence of mantle material mixing in the source area. Zircon trace elements show that the pre-mineralization magma (Linglong) had relatively low oxygen fugacity and temperature (ΔFMQ = −2.5 to +1.9, T-Ti in zircon (mean) = 740°C) compared to the mineralization magma (ΔFMQ = +0.5 to +3.9, T-Ti in zircon (mean) = 755°C). The physicochemical conditions in the pre-mineralization magma source area may be favorable for sulfide accumulation (may including gold). During the Early Cretaceous, North China Craton decratonization reached its climax, and a large number of adakitic crust-mantle mixed oxidized magma upwells, allowing for the migration and mineralization of a large amount of sulfides and gold. This model helps explain the transient, explosive, and genetic categories in Jiaodong gold deposits.
    Type of Medium: Online Resource
    ISSN: 2296-6463
    URL: Article
    URL: Article
    URL: Article
    URL: Article
    URL: Article
    DOI: 10.3389/feart.2023.1243844
    DOI: 10.3389/feart.2023.1243844.s001
    DOI: 10.3389/feart.2023.1243844.s002
    DOI: 10.3389/feart.2023.1243844.s003
    DOI: 10.3389/feart.2023.1243844.s004
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2023
    detail.hit.zdb_id: 2741235-0
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  • 2
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    Online Resource
    Dynamic recognition of naloxone, morphine and endomorphin1 in the same pocket of µ-opioid receptors
    Frontiers Media SA ; 2022
    In:  Frontiers in Molecular Biosciences Vol. 9 ( 2022-8-16)
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    In: Frontiers in Molecular Biosciences, Frontiers Media SA, Vol. 9 ( 2022-8-16)
    Abstract: Morphine, the most widely used analgesic, relieves severe pain by activating the μ-opioid receptor (MOR), whereas naloxone, with only slight structural changes compared to morphine, exhibits inhibitory effect, and is used to treat opioid abuse. The mechanism by which the MOR distinguishes between the two is unclear. Molecular dynamics (MD) simulations on a 1-μs time scale and metadynamics-enhanced conformational sampling are used here to determine the different interactions of these two ligands with MOR: morphine adjusted its pose by continuously flipping deeper into the pocket, whereas naloxone failed to penetrate deeper because its allyl group conflicts with several residues of MOR. The endogenous peptide ligand endomorphin-1 (EM-1) underwent almost no significant conformational changes during the MD simulations. To validate these processes, we employed GIRK4 S143T , a MOR-activated G βγ -protein effector, in combination with mutagenesis and electrophysiological recordings. We verified the role of some key residues in the dynamic recognition of naloxone and morphine and identified the key residue I322, which leads to differential recognition of morphine and naloxone while assisting EM-1 in activating MOR. Reducing the side chain size of I322 (MOR I322A ) transformed naloxone from an inhibitor directly into an agonist of MOR, and I322A also significantly attenuated the potency of MOR on EM-1, confirming that binding deep in the pocket is critical for the agonistic effect of MOR. This finding reveals a dynamic mechanism for the response of MOR to different ligands and provides a basis for the discovery of new ligands for MOR at the atomic level.
    Type of Medium: Online Resource
    ISSN: 2296-889X
    URL: Article
    DOI: 10.3389/fmolb.2022.925404
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2022
    detail.hit.zdb_id: 2814330-9
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  • 3
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    Thymopentin-Mediated Inhibition of Cancer Stem Cell Stemness Enhances the Cytotoxic Effect of Oxaliplatin on Colon Cancer Cells
    Frontiers Media SA ; 2022
    In:  Frontiers in Pharmacology Vol. 13 ( 2022-2-15)
    Details
    In: Frontiers in Pharmacology, Frontiers Media SA, Vol. 13 ( 2022-2-15)
    Abstract: Thymopentin (TP5) is an immunomodulatory pentapeptide that has been widely used in malignancy patients with immunodeficiency due to radiotherapy and chemotherapy. Here, we propose that TP5 directly inhibits the stemness of colon cancer cells HCT116 and therefore enhances the cytotoxicity of oxaliplatin (OXA) in HCT116 cells. In the absence of serum, TP5 was able to induce cancer stemness reduction in cultured HCT116 cells and significantly reduced stemness-related signals, such as the expression of surface molecular markers (CD133, CD44 and CD24) and stemness-related genes (ALDH1, SOX2, Oct-4 and Nanog), and resulted in altered Wnt/β-catenin signaling. Acetylcholine receptors (AchRs) are implicated in this process. OXA is a common chemotherapeutic agent with therapeutic effects in various cancers. Although TP5 had no direct effect on the proliferation of HCT116, this pentapeptide significantly increased the sensitivity of HCT116 to OXA, where the effect of TP5 on the stemness of colon cancer cells through stimulation of AchRs may contribute to this process. Our results provide a promising strategy for increasing the sensitivity of colon cancer cells to chemotherapeutic agents by incorporating immunomodulatory peptides.
    Type of Medium: Online Resource
    ISSN: 1663-9812
    URL: Article
    DOI: 10.3389/fphar.2022.779715
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2022
    detail.hit.zdb_id: 2587355-6
    SSG: 15,3
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