Publications by authors named "Yong-Feng Cheng"

Objectives: To investigate the mechanism by which mycobacterial antigen 85B (Ag85B) inhibits autophagy and promotes apoptosis in Hodgkin lymphoma (HL) cells.

Methods: The clinical data and pathological tissue slides were retrospectively collected from 80 HL children and 30 children with reactive lymphadenopathy (control group) treated at the First Affiliated Hospital of Xinjiang Medical University. Immunohistochemical analysis was performed to assess the expression of microtubule-associated protein 1 light chain 3 (LC3), sequestosome 1 (P62/SQSTM1), and Beclin-1 in the pathological tissues of HL and control groups.

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Article Synopsis
  • * Researchers found that injecting PD-L1 at the neck helped reduce chronic itch caused by imiquimod treatment and that spontaneous scratching behavior lessened after 21 days.
  • * Despite reduced scratching, using PD-1/PD-L1 inhibitors led to prolonged itching, showing that itch sensitivity persisted, with changes observed in PD-1 receptor levels and spinal microglia activity, indicating these pathways may play a role in chronic itch regulation.
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Transition-metal-catalyzed enantioselective functionalization of acyl radicals has so far not been realized, probably due to their relatively high reactivity, which renders the chemo- and stereocontrol challenging. Herein, we describe Cu(I)-catalyzed enantioselective desymmetrizing C-O bond coupling of acyl radicals. This reaction is compatible with (hetero)aryl and alkyl aldehydes and, more importantly, displays a very broad scope of challenging alcohol substrates, such as 2,2-disubstituted 1,3-diols, 2-substituted-2-chloro-1,3-diols, 2-substituted 1,2,3-triols, 2-substituted serinols, and meso primary 1,4-diols, providing enantioenriched esters characterized by challenging acyclic tetrasubstituted carbon stereocenters.

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  • * This study introduces a new method using single-electron reductive elimination for enantioselective sulfur-oxygen coupling with copper catalysts, supported by experimental and theoretical data.
  • * The method shows promise in producing challenging chiral alcohols from biomass-derived glycerol and effectively desymmetrizing inositol, highlighting its potential for general use in creating chiral heteroatom-heteroatom bonds.
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Objective: The thickened coracohumeral ligament (CHL) is an important part of the typical manifestations and magnetic resonance imaging of frozen shoulder. However, only a few clinical studies with limited cases on arthroscopic extra-articular entire CHL release exist in the literature. This study was to evaluate the effect of arthroscopic extra-articular entire CHL release for patients with recalcitrant frozen shoulder.

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Background: Colorectal cancer (CRC) is one of the most common malignancies and the patient survival rate remains unacceptably low. The anti-programmed cell death-1 (PD-1)/programmed cell death ligand 1 (PD-L1) antibody-based immune checkpoint inhibitors have been added to CRC treatment regimens, however, only a fraction of patients benefits. As an important co-stimulatory molecule, 4-1BB/CD137 is mainly expressed on the surface of immune cells including T and natural killer (NK) cells.

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A copper-catalyzed highly -selective radical 1,2-alkylarylation of terminal alkynes with aryl boronic acids and alkyl bromides has been established. The reaction exhibits high compatibility with a wide range of terminal alkynes and diverse aryl boronic acids, thus providing facile access to various stereodefined trisubstituted alkenes in high yield under mild reaction conditions. Preliminary mechanistic investigations support the formation of alkyl radicals and their subsequent addition to alkynes in the reaction.

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Although great success has been achieved in catalytic asymmetric hydroamination of unactivated alkenes using transition metal catalysis and organocatalysis, the development of catalytic desymmetrising hydroamination of such alkenes remains a tough challenge in terms of attaining a high level of stereocontrol over both remote sites and reaction centers at the same time. To address this problem, here we report a highly efficient and practical desymmetrising hydroamination of unactivated alkenes catalysed by chiral Brønsted acids with both high diastereoselectivity and enantioselectivity. This method features a remarkably broad alkene scope, ranging from mono-substituted and -/1,2-disubstituted to the challenging tri- and tetra-substituted alkenes, to provide access to a variety of diversely functionalized chiral pyrrolidines bearing two congested tertiary or quaternary stereocenters with excellent efficiency under mild and user-friendly synthetic conditions.

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Since the pioneering independent reports of Akiyama and Terada, the use of chiral phosphoric acids (CPAs) and derivatives as a versatile tool for asymmetric synthesis with good reactivity, regioselectivity, diastereoselectivity and enantioselectivity has emerged, forming an important part of the implementation of asymmetric counteranion-directed catalysis reported to date. In these achievements, the combination of metals with CPAs has enabled various catalytic modes beyond the scope of typical acid catalysis, such as relay catalysis, ion-pairing catalysis, and binary acid catalysis. The first-row transition metals (Sc-Zn) are considered to be sustainable transition metals and have received a great deal of attention.

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Objective: To study the expression of the Fra-1 gene in the peripheral blood of children with Wilms tumor and its clinical significance.

Methods: Fifty children pathologically diagnosed with Wilms tumor between December 2012 and January 2018 were enrolled as the case group, and 40 healthy children for physical examination were selected as the control group. Among the 45 children with Wilms tumor who were followed up, the children with continuous remission were included in the ideal efficacy group (n=33), and those with recurrence, metastasis or death were included in the poor efficacy group (n=12).

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A redox-neutral α-C-H oxygenation of commercially available pyrrolidin-3-ol with a monoprotected p-quinone generated an N-aryliminium ion intermediate, which reacted in situ with boronic acid nucleophiles to produce a series of cis-2-substituted pyrrolidin-3-ols. With this strategy, 8-epi-(-)-lentiginosine was synthesized from (3R,4R)-pyrrolidine-3,4-diol in three steps.

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Article Synopsis
  • A new strategy using achiral pyridine as a ligand has been developed to stabilize high-valent copper species for asymmetric radical oxytrifluoromethylation of alkenes.
  • The process operates under mild conditions and accommodates a wide variety of substrates, resulting in trifluoromethyl-substituted tetrahydrofurans with high enantioselectivity.
  • Mechanistic studies indicate that the achiral pyridine plays a crucial role in stabilizing key reactive species during the reaction.
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Medium-sized and medium-bridged rings are attractive structural motifs in natural products and therapeutic agents. Due to the unfavourable entropic and/or enthalpic factors with these ring systems, their efficient construction remains a formidable challenge. To address this problem, we herein disclose a radical-based approach for diversity-oriented synthesis of various benzannulated carbon- and heteroatom-containing 8-11(14)-membered ketone libraries.

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The late-stage oxidation of substituted pyrrolidines offers good flexibility for the construction of γ-lactam libraries, and especially in recent years the methods for functionalization of pyrrolidine have been available. We reported a new strategy for oxidation of pyrrolidines to γ-lactams: reaction of pyrrolidine with an o-benzoquinone gives an N,O-acetal by direct oxidation of the α-C-H bond of the pyrrolidine ring, and then the N,O-acetal is further oxidized by the o-benzoquinone to the γ-lactam. Because the first oxidation occurs selectively at the α-C-H of the pyrrolidine ring, oxidation-sensitive functional groups (allyl-, vinyl-, hydroxyl-, and amino groups) on pyrrolidine ring are unaffected.

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By using o-benzoquinone as an internal oxidant, the regio- and diastereoselective functionalization of the secondary over the tertiary α-C-H bond of 2-substituted pyrrolidines is first realized. Subsequent intermolecular addition of a nucleophile to the generated N,O-acetal and cleavage of the aromatic substituent leads to 2,5-disubstituted pyrrolidines.

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