45 research outputs found

    Cytotoxic coumaronochromones from the inflorescences of <i>Celosia cristata</i>

    No full text
    <p>Investigation on the MeOH extracts of the inflorescences of <i>Celosia cristata</i> led to the isolation of two new coumaronochromones, cristatone I (<b>1</b>) and cristatone II (<b>2</b>), along with three known flavones (<b>3</b>–<b>5</b>). Their structures were elucidated on the basis of spectroscopic analyses. Compounds <b>1</b>–<b>5</b> were tested for their cytotoxic activity against HeLa and BGC-823 cancer cell lines, of which cristatone II (<b>2</b>) showed interesting activity with the IC<sub>50</sub> value of 23.82 μM.</p

    Reduced Graphene Oxide-Based Solid-Phase Extraction for the Enrichment and Detection of microRNA

    No full text
    MicroRNAs (miRNAs) are endogenous molecules with regulatory functions. The purification and enrichment of miRNA are essential for its precise and sensitive detection. miRNA isolated using commercial kits contains abundant interfering RNAs, and the concentration of miRNA may not be adequate for detection. Herein, we prepared a reduced graphene oxide (rGO)-based magnetic solid-phase extraction material for the enrichment and ultrasensitive detection of miRNA from intricate nucleic acid solutions. <i>In situ</i> reverse transcription (RT) was developed as the most efficient approach to desorb miRNA from rGO among the methods that are compatible for the subsequent amplification reported thus far. Additionally, rolling circle amplification and qPCR were used to detect let-7a with a decrease of the limit of detection by 24.7- and 31.3-fold, respectively. This material was also successfully used to extract and detect miRNA from total RNA isolated from human plasma. Our results show that the material prepared in this study has the potential for cancer biopsy in clinics and the discovery of new miRNAs in scientific research

    sj-rar-1-jim-10.1177_1045389X221131806 – Supplemental material for A novel laparoscopic surgical robot (LSR) based on double-leg ultrasonic motor (DUM)

    No full text
    Supplemental material, sj-rar-1-jim-10.1177_1045389X221131806 for A novel laparoscopic surgical robot (LSR) based on double-leg ultrasonic motor (DUM) by Qing Lu, Zhijun Sun, He Yan, Jiacheng Zhang, Jialiang Zhang and Jianlin Yang in Journal of Intelligent Material Systems and Structures</p

    sj-rar-2-jim-10.1177_1045389X221131806 – Supplemental material for A novel laparoscopic surgical robot (LSR) based on double-leg ultrasonic motor (DUM)

    No full text
    Supplemental material, sj-rar-2-jim-10.1177_1045389X221131806 for A novel laparoscopic surgical robot (LSR) based on double-leg ultrasonic motor (DUM) by Qing Lu, Zhijun Sun, He Yan, Jiacheng Zhang, Jialiang Zhang and Jianlin Yang in Journal of Intelligent Material Systems and Structures</p

    Selenophene-Incorporated Quaterchalcogenophene-Based Donor–Acceptor Copolymers To Achieve Efficient Solar Cells with <i>J</i><sub>sc</sub> Exceeding 20 mA/cm<sup>2</sup>

    No full text
    Three selenophene-incorporated quaterchalcogenophene-based donor–acceptor copolymers PFBT2Th2Se, PFBT2Se2Th, and PFBT4Se are designed and synthesized. To systematically fine-tune the molecular properties and investigate the chalcogen effect, PFBT2Th2Se and PFBT2Se2Th hybridize two thiophenes and two selenophenes as the donor with different isomeric main-chain placement while thiophene-free PFBT4Se uses quaterselenophene as the donor. On account of the selenophene’s advantageous features such as higher quinoidal population and higher molecular polarizability, the three polymers show good light-harvesting ability, strong intermolecular interactions, high crystallinity, and high charge mobilities. Bulk-heterojunction solar cells incorporating these selenophene-containing polymers have exhibited promising photovoltaic performance with impressive current densities over 20 mA/cm<sup>2</sup>. The device with the PFBT2Se2Th:PC<sub>71</sub>BM blend showed a PCE of 9.02% with a <i>J</i><sub>sc</sub> of 21.02 mA/cm<sup>2</sup>. In addition, the device using quaterselenophene-based PFBT4Se:PC<sub>71</sub>BM blend exhibited a PCE of 8.92% with a superior <i>J</i><sub>sc</sub> of 22.63 mA/cm<sup>2</sup> which represents one of the highest current densities from polymer:fullerene-based solar cells reported in the literature

    Surface Decoration on Polymeric Gate Dielectrics for Flexible Organic Field-Effect Transistors via Hydroxylation and Subsequent Monolayer Self-Assembly

    No full text
    A simple photochemical reaction based on confined photocatalytic oxidation (CPO) treatment and hydrolysis was employed to efficiently convert C–H bonds into C–OH groups on polymeric material surfaces, followed by investigation of monolayer self-assembly decoration on polymeric dielectrics via chemical bonding for the organic field-effect transistors (OFETs) applications. This method is a low temperature process and has negligible etching effect on polymeric dielectric layers. Various types of self-assembled monolayers have been tested and successfully attached onto the hydroxylated polymeric dielectric surfaces through chemical bonding, ensuring the stability of decorated functional films during the subsequent device fabrication consisting of solution processing of the polymer active layer. With the surface decoration of functional groups, both n-type and p-type polymers exhibit enhanced carrier mobilities in the unipolar OFETs. In addition, enhanced and balanced mobilities are obtained in the ambipolar OFETs with the blend of polymer semiconductors. The anchored self-assembled monolayers on the dielectric surfaces dramatically preclude the solvent effect, thus enabling an improvement of carrier mobility up to 2 orders of magnitude. Our study opens a way of targeted modifications of polymeric surfaces and related applications in organic electronics

    Put Your Backbone into It: Excited-State Structural Relaxation of PffBT4T-2DT Conducting Polymer in Solution

    No full text
    Conformational and energetic disorder in organic semiconductors reduces charge and exciton transport because of the structural defects, thus reducing the efficiency in devices such as organic photovoltaics and organic light-emitting diodes. The main structural heterogeneity is because of the twisting of the polymer backbone that occurs even in polymers that are mostly crystalline. Here, we explore the relationship between polymer backbone twisting and exciton delocalization by means of transient absorption spectroscopy and density functional theory calculations. We study the PffBT4T-2DT polymer which has exhibited even higher device efficiency with nonfullerene acceptors than the current record breaking PCE11 polymer. We determine the driving force for planarization of a polymer chain caused by excitation. The methodology is generally applicable and demonstrates a higher penalty for nonplanar structures in the excited state than in the ground state. This study highlights the morphological and electronic changes in conjugated polymers that are brought about by excitation

    Study on the Antifungal Activity and Potential Mechanism of Natamycin against Colletotrichum fructicola

    No full text
    In this investigation, the antifungal activity, its influence on the quality of apples, and the molecular mechanism of natamycin against Colletotrichum fructicola were systematically explored. Our findings indicated that natamycin showed significant inhibition against C. fructicola. Moreover, it efficaciously maintained the apple quality by modulating the physicochemical index. Research on the antifungal mechanism showed that natamycin altered the mycelial microstructure, disrupted the plasma membrane integrality, and decreased the ergosterol content of C. fructicola. Interestingly, the exogenous addition of ergosterol weakened the antifungal activity of natamycin. Importantly, natamycin markedly inhibited the expression of Cyp51A and Cyp51B genes in C. fructicola, which was contrary to the results obtained after treatment with triazole fungicide flusilazole. All these results exhibited sufficient proof that natamycin had enormous potential to be conducive as a promising biopreservative against C. fructicola on apples, and these findings will advance our knowledge on the mechanism of natamycin against pathogenic fungi
    corecore