Publications by authors named "Meng-chen Zhang"

Asymmetric intermolecular C-H functionalization of pyridines at C3 is unprecedented. Herein, we report the first examples of such transformations: specifically, C3-allylation of pyridines via tandem borane and iridium catalysis. First, borane-catalyzed pyridine hydroboration generates nucleophilic dihydropyridines; then, the dihydropyridine undergoes enantioselective iridium-catalyzed allylation; and finally, oxidative aromatization with air as the oxidant gives the C3-allylated pyridine.

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Article Synopsis
  • The salivary glands produce saliva, which serves multiple important functions such as aiding in digestion, protecting oral mucosa, and modulating immune responses.
  • Saliva secretion is regulated by the central nervous system in response to various stimuli like taste, smell, and chewing, with different neurotransmitters influencing the process.
  • Recent studies highlight the salivary glands' roles in immunity and endocrinology, identifying potential biomarkers in saliva that could help in diagnosing oral and systemic diseases.
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Hypothalamus-pituitary-adrenal (HPA) axis plays critical roles in stress responses under challenging conditions such as hypoxia, regulating gene expression and integrating activities of hypothalamus-pituitary-targets cells. However, the transcriptional regulatory mechanisms and signaling pathways of hypoxic stress in the pituitary remain to be defined. Here, we report that hypoxia induced dynamic changes in the transcription factors, hormones, and their receptors in the adult rat pituitary.

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Based on UPLC characteristic chromatogram and quantitative analysis of multi-components by single marker(QAMS), the content of seven types of ginsenosides in Ginseng Radix et Rhizoma was simultaneously determined, and the quality of Ginseng Radix et Rhizoma was evaluated by the principal component analysis(PCA). The chromatographic separation was performed on the Acquity UPLC BEH C_(18) column(2.1 mm×100 mm, 1.

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The common understanding of p53 function is a genome guardian, which is activated by diverse stresses stimuli and mediates DNA repair, apoptosis, and cell cycle arrest. Increasing evidence has demonstrated p53 new cellular functions involved in abundant endocrine and metabolic response for maintaining homeostasis. However, is frequently mutant in human cancers, and the mutant p53 (Mut-p53) turns to an "evil" cancer-assistant.

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Objectives: Intravoxel incoherent motion (IVIM) diffusion-weighted magnetic resonance imaging (MRI) provides information on both perfusion and diffusion and has been used to evaluate Crohn's disease (CD) activity and fibrosis in children; however, there are no reports on its use in adults. We aimed to determine its value for detecting and grading intestinal fibrosis in adults with CD compared with contrast-enhanced imaging and traditional diffusion-weighted imaging using surgical histopathology as a reference standard.

Methods: Twenty-four adults with CD underwent preoperative IVIM, traditional diffusion-weighted, and contrast-enhanced imaging.

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Article Synopsis
  • - The study aimed to compare T2* mapping and contrast-enhanced imaging in assessing bowel fibrosis in Crohn's disease patients, using surgical pathology as the gold standard for validation.
  • - T2* values significantly varied among fibrosis severity levels, showing strong correlations with histological findings and yielding high accuracy in distinguishing between different fibrosis degrees (AUC of 0.951).
  • - A T2* threshold value of 18.06 ms is proposed for effectively diagnosing moderate-to-severe fibrosis in patients with Crohn's disease.
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Background: Identification of the quantitative trait locus (QTL) underlying salt tolerance is a prerequisite for marker-assisted selection in the salt-tolerant breeding process.

Methods: In this study, the recombinant inbred lines derived from the salt-tolerant elite soybean cultivar 'Jidou 12' and the salt-sensitive elite cultivar 'Ji NF 58' were used to identify the QTL associated with salt tolerance, using both salt tolerance rating (STR) and leaf chlorophyll content (SPAD) as indicators.

Results: A major salt-tolerant QTL, which was flanked by SSR markers GMABAB and Barcsoyssr_03_1421 on chromosome 3, was identified based on single-marker regression, single trait composite interval mapping, and multiple interval mapping analysis.

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Mainly due to their economic importance, genomes of 10 legumes, including soybean (), wild peanut ( and ), and barrel medic (), have been sequenced. However, a family-level comparative genomics analysis has been unavailable. With grape () and selected legume genomes as outgroups, we managed to perform a hierarchical and event-related alignment of these genomes and deconvoluted layers of homologous regions produced by ancestral polyploidizations or speciations.

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Antagonists and sonication treatment relieved the structural barriers of Agrobacterium entering into cells; hindered signal perception and transmission; alleviated defense responses and increased cell susceptibility to Agrobacterium infection. Soybean gene expression analysis was performed to elucidate the general response of soybean plant to Agrobacterium at an early stage of infection. Agrobacterium infection stimulated the PAMPs-triggered immunity (BRI1, BAK1, BZR1, FLS2 and EFR) and effector-triggered immunity (RPM1, RPS2, RPS5, RIN4, and PBS1); up-regulated the transcript factors (WRKY25, WRKY29, MEKK1P, MKK4/5P and MYC2) in MAPK pathway; strengthened the biosynthesis of flavonoid and isoflavonoid in the second metabolism; finally led to a fierce defense response of soybean to Agrobacterium infection and thereby lower transformation efficiency.

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Background: Artificial selection played an important role in the origin of modern Glycine max cultivars from the wild soybean Glycine soja. To elucidate the consequences of artificial selection accompanying the domestication and modern improvement of soybean, 25 new and 30 published whole-genome re-sequencing accessions, which represent wild, domesticated landrace, and Chinese elite soybean populations were analyzed.

Results: A total of 5,102,244 single nucleotide polymorphisms (SNPs) and 707,969 insertion/deletions were identified.

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Article Synopsis
  • The study analyzed 14 agronomic traits and 139 SSR loci in the soybean cultivar Suinong 14 to assess its genetic diversity and potential for breeding improvements.
  • Cluster analysis based on SSR markers aligned with pedigree data, revealing an average genetic similarity coefficient of 0.6380 among cultivars, with specific SSR locus combinations needed to differentiate Suinong 14 from its related varieties.
  • Random distribution of recombination within linkage groups was found, with only one SSR locus (Satt168) showing significant transmission from parent Zihua 4, indicating substantial genetic changes after five generations of breeding.
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