Publications by authors named "Yan-Jun Yu"

Article Synopsis
  • - The study introduces a new technique combining liquid and vapor-phase growth methods to create two-dimensional organic lateral heterostructures (2D OLHs) from perylene and its derivatives, achieving sizes of ~20 μm and thicknesses between 20 to 400 nm.
  • - The growth process involves a unique screw dislocation behavior that organizes atoms in a spiral pattern, reducing defects and maintaining structural integrity during crystal formation.
  • - The resulting 2D OLHs exhibit excellent light-transport properties and adjustable exciton conversion, making them promising for use in photonic applications, and the method may be applied to other aromatic hydrocarbon compounds.
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In terms of tunable luminescence and high quantum efficiency, colloidal quantum dots (CQDs) are promising semiconductors for constructing near-infrared light-emitting diodes (NIR-LEDs). However, currently available NIR-LEDs are susceptible to variations in the emission layer thickness (EMLT), the highest external quantum efficiency (EQE) decreases to below 50% (relative to peak EQE) when the EMLT varies out of a narrow range of (±30 nm). This is due to the thickness-dependent carrier recombination rate and current density variation, resulting in batch-to-batch EQE fluctuations that limit LED reproducibility.

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Article Synopsis
  • * Despite their potential, blue QLEDs face challenges related to efficiency and stability, which hinder their widespread use and production.
  • * The review discusses various factors affecting blue QLED performance and outlines a roadmap for improvement, focusing on advancements in different types of quantum dots and key aspects like material synthesis and device fabrication.
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Perovskite nanocrystals (PeNCs) deliver size- and composition-tunable luminescence of high efficiency and color purity in the visible range. However, attaining efficient electroluminescence (EL) in the near-infrared (NIR) region from PeNCs is challenging, limiting their potential applications. Here we demonstrate a highly efficient NIR light-emitting diode (LED) by doping ytterbium ions into a PeNCs host (Yb  : PeNCs), extending the EL wavelengths toward 1000 nm, which is achieved through a direct sensitization of Yb ions by the PeNC host.

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Article Synopsis
  • The study aimed to create a diatom database by analyzing water samples from various sections of the Beijing-Hangzhou Grand Canal to help determine possible drowning sites.
  • Water samples were collected from 22 different locations, and diatoms were examined using advanced microscopy techniques to assess their quantity and species distribution.
  • Results showed significant variation in diatom counts, with one site having 68 times more diatoms than another, and while species diversity was generally consistent, the richness of diatom species increased from north to south, influenced by environmental complexity and population density.
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Perovskite photovoltaics are strong potential candidates to drive low-power off-grid electronics for indoor applications. Compared with rigid devices, flexible perovskite devices can provide a more suitable surface for indoor small electronic devices, enabling them have a broader indoor application prospect. However, the mechanical stability of flexible perovskite photovoltaics is an urgent issue solved.

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Phosphodiesterase-5 (PDE5) inhibitors have been approved for the treatment of erectile dysfunction and pulmonary hypertension, but enthusiasm on discovery of PDE5 inhibitors continues for their potential new applications. Reported here is discovery of a series of new PDE5 inhibitors by structure-based design, molecular docking, chemical synthesis, and enzymatic characterization. The best compound, 3-(4-hydroxybenzyl)-1-(thiophen-2-yl)chromeno[2,3-c]pyrrol-9(2H)-one (57), has an IC₅₀ of 17 nM against the PDE5 catalytic domain and good selectivity over other PDE families.

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Natural oligomeric procyanidin (OPC) with high biological and pharmacological activities was successfully used to synthesize OPC-insulin (OPC-INS) nanoparticles with different aggregation sizes for sustained and controlled delivery of hydrophilic insulin. The aggregation size of OPC-INS nanoparticles was regulated by OPC concentration, pH value, and incubation time. The fabrication mechanism would be that OPC and insulin self-assembled into a mixture of insulin aggregates via intermolecular interactions.

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Series of curcumin derivatives were synthesized; the inhibitory activities on thioredoxin reductase (TrxR) of all analogues were evaluated by DTNB assay in vitro. It is found that most of the analogues can inhibit TrxR in the low micromolar range; Structure-activity relationship analysis reveals that analogues with furan moiety have excellent inhibitory effect on TrxR in an irreversible manner, indicating that the furan moiety may serve as a possible pharmacophore during the interaction of curcumin analogues with TrxR. The effect of selected curcuminoids on growth of different TrxR overexpressed cancer cell lines was also investigated and discussed.

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The author found a novel yellow-white flower color mutation in the male sterile progenies derived from a commercial Brassica.napus hybrid C022, which was produced by a male sterility line 9012A, whose sterility was controlled by interaction between two pairs recessive genes and a pair of epitatic genes. The mutant was named 991S.

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Synopsis of recent research by authors named "Yan-Jun Yu"

  • - Yan-Jun Yu's research primarily focuses on advancements in materials science, particularly in the synthesis and application of various organic and inorganic nanostructures for optoelectronic devices, including quantum dot light-emitting diodes (QLEDs) and organic heterostructures.
  • - His recent studies highlight the successful development of techniques for lateral epitaxial growth of two-dimensional organic heterostructures, addressing challenges in controlled synthesis for functional materials, and exploring strategies for efficient near-infrared electroluminescence using lanthanide-doped perovskites.
  • - Additionally, Yu investigates the performance and stability of quantum dot LEDs, striving to overcome limitations in emission layer thickness variations, and provides insights into the future of flexible perovskite photovoltaics appealing for indoor application scenarios.