74 research outputs found

    Bufotalin-loaded biomimetic Prussian blue nanoparticles for colorectal cancer chemo-photothermal ferroptosis therapy - supplementary figures

    No full text
    Purpose: We constructed biomimetic nanoparticles with biocompatible, tumor-targeting, laser-responsive properties for ferroptosis-induced colorectal cancer chemo-photothermal therapy, with the aim to realize double-hit ferroptosis treatment for colorectal cancer. Methods: The nanoparticles were prepared by first loading the chemotherapy drug bufotalin (CS-5) with Prussian blue (PB), then combining a hybridized erythrocyte–tumor membrane (M) with PB@CS-5 to produce PB@CS-5@M. The chemo-photothermal therapy efficiency of PB@CS-5@M was tested by in vitro and in vivo experiments. Results and conclusion: The combined PB and CS-5 act as promising ferroptosis inducers to enhance ferroptosis efficacy. The hyperthermia induced by laser stimulation can trigger PB to release CS-5 and iron and ferrous ions, which further promotes ferroptosis.</p

    DataSheet1_Correlation analysis between biomechanical characteristics of taekwondo double roundhouse kick and effective scoring of electronic body protector.xlsx

    No full text
    Objective: To explore the inherent relationship between lower limb biomechanical indicators and effective scoring values of double roundhouse kick (DRK) by taekwondo athletes, and to find key biomechanical factors that trigger effective scoring.Methods: Using the DAEDO Protector and Scoring System (PSS) in conjunction with the Vicon optical motion capture system and Kistler 3D force plate, kinematic and dynamic indicators of the front kicking motion were obtained from 12 professional taekwondo athletes (18.00 ± 2.20 years, 182.15 ± 8.62 cm and 70.00 ± 14.82 kg). The correlation between kinematics, dynamics, and scoring values was initially analyzed using bivariate linear correlation. Subsequently, based on the results of the linear correlation analysis, a stepwise regression analysis was performed to establish a stepwise regression equation.Results: The results reveal that during the First Hit, there is a significant positive correlation (r > 0, p 1.023). During the Second Hit, there is a significant positive correlation (r > 0, p 1.023).Conclusion: Explosive power, body posture, adequate terminal velocity, and body rotation have an association with effective scoring of the electronic protector. The peak angular velocity of the ankle joint of the dominant leg and the peak linear velocity of the foot horizontal plane of the non-dominant leg significantly contribute to the effectiveness score of the electronic protector.</p

    LiMn<sub>0.8</sub>Fe<sub>0.2</sub>PO<sub>4</sub>/C Nanoparticles via Polystyrene Template Carburizing Enhance the Rate Capability and Capacity Reversibility of Cathode Materials

    No full text
    In order to unlock the electrochemical performance ability of manganese-based lithium ferromanganese phosphate cathode materials, CP1–LiMn0.8Fe0.2PO4/C (coprecipitation) nanocomposites were prepared by introducing polystyrene nanospheres as templates and carbon sources into the coprecipitation method combined with a multistage carburizing heat treatment. In the processes of heat treatment, polystyrene nanospheres can not only build a conductive carbon layer and optimize the electron transport path but also refine the particles and inhibit the nanoparticle aggregation. The interconnected conductive carbon coating significantly improves the diffusion coefficient of lithium ions, which assists LiMn0.8Fe0.2PO4 in lifting discharge specific capacity and cycle performance. The test results show that the as-prepared CP1–LiMn0.8Fe0.2PO4/C shows superior rate capability (130.5 mAh g–1 at 0.1C and 92.8 mAh g–1 at 5C) and capacity reversibility (95.5% after 200 cycles at 0.5C)

    Table_1_Two vacuolar invertase inhibitors PpINHa and PpINH3 display opposite effects on fruit sugar accumulation in peach.xlsx

    No full text
    Soluble sugars are an important determinant of fruit taste, but their accumulation mechanisms remain elusive. In this study, we report two vacuolar invertase inhibitor genes involved in sugar accumulation in peach, PpINHa and PpINH3. Transient overexpression of PpINH3 in peach fruits resulted in an increase in sugar content, while the opposite trend was detected for PpINHa. Unexpectedly, PpINH3 and PpINHa both had no physical interaction with vacuolar invertase (VIN). Moreover, the PpVIN genes had no or extremely low expression in fruits at the ripening stage. These results suggested that the regulatory role of PpINHa and PpINH3 in sugar accumulation is unlikely due to their interaction with PpVINs. Additionally, overexpression of PpINHa and PpINH3 had an impact on transcription of genes related to fruit sugar metabolism and transport, which is likely responsible for their regulatory role in fruit sugar accumulation. Altogether, these results indicated an important role of PpINHs in fruit accumulation in peach. Our study provides new insights into molecular mechanisms underlying sugar accumulation, which could be useful for genetic improvement of fruit taste in breeding programs of peach and other fruit crops.</p

    DataSheet_1_Two vacuolar invertase inhibitors PpINHa and PpINH3 display opposite effects on fruit sugar accumulation in peach.docx

    No full text
    Soluble sugars are an important determinant of fruit taste, but their accumulation mechanisms remain elusive. In this study, we report two vacuolar invertase inhibitor genes involved in sugar accumulation in peach, PpINHa and PpINH3. Transient overexpression of PpINH3 in peach fruits resulted in an increase in sugar content, while the opposite trend was detected for PpINHa. Unexpectedly, PpINH3 and PpINHa both had no physical interaction with vacuolar invertase (VIN). Moreover, the PpVIN genes had no or extremely low expression in fruits at the ripening stage. These results suggested that the regulatory role of PpINHa and PpINH3 in sugar accumulation is unlikely due to their interaction with PpVINs. Additionally, overexpression of PpINHa and PpINH3 had an impact on transcription of genes related to fruit sugar metabolism and transport, which is likely responsible for their regulatory role in fruit sugar accumulation. Altogether, these results indicated an important role of PpINHs in fruit accumulation in peach. Our study provides new insights into molecular mechanisms underlying sugar accumulation, which could be useful for genetic improvement of fruit taste in breeding programs of peach and other fruit crops.</p

    Unraveling the Role of a Flexible Tetradentate Ligand in the Aerobic Oxidative Carbon–Carbon Bond Formation with Palladium Complexes: A Computational Mechanistic Study

    Get PDF
    Mechanistic details of the aerobic oxidative coupling of methyl groups by a novel (<sup>Me</sup>L)­Pd<sup>II</sup>(Me)<sub>2</sub> complex with the tetradentate ligand, <sup>Me</sup>L = <i>N</i>,<i>N</i>-dimethyl-2,11-diaza­[3.3]­(2,6)­pyridinophane, has been explored by density functional theory calculations. The calculated mechanism sheds light on the role of this ligand’s flexibility in several stages of the reaction, especially as the oxidation state of the Pd changes. Ligand flexibility leads to diverse axial coordination modes, and it controls the availability of electrons by modulating the energies of high-lying molecular orbitals, particularly those with major d<sub><i>z</i></sub><sup><sub>2</sub></sup> character. Solvent molecules, particularly water, appear essential in the aerobic oxidation of Pd<sup>II</sup> by lowering the energy of the oxygen molecule’s unoccupied molecular orbital and stabilizing the Pd<sup>X</sup>–O<sub>2</sub> complex. Ligand flexibility and solvent coordination to oxygen are essential to the required spin-crossover for the transformation of high-valent Pd<sup>X</sup>–O<sub>2</sub> complexes. A methyl cation pathway has been predicted by our calculations in transmetalation between Pd<sup>II</sup> and Pd<sup>IV</sup> intermediates to be preferred over methyl radical or methyl anion pathways. Combining an axial and equatorial methyl group is preferred in the reductive elimination pathway where roles are played by the ligand’s flexibility and the fluxionality of trimethyl groups

    General Approach To Compute Phosphorescent OLED Efficiency

    No full text
    Phosphorescent organic light-emitting diodes (PhOLEDs) are widely used in the display industry. In PhOLEDs, cyclometalated Ir­(III) complexes are the most widespread triplet emitter dopants to attain red, e.g., Ir­(piq)<sub>3</sub> (piq = 1-phenylisoquinoline), and green, e.g., Ir­(ppy)<sub>3</sub> (ppy = 2-phenylpyridine), emissions, whereas obtaining operative deep-blue emitters is still one of the major challenges. When designing new emitters, two main characteristics besides colors should be targeted: high photostability and large photoluminescence efficiencies. To date, these are very often optimized experimentally in a trial-and-error manner. Instead, accurate predictive tools would be highly desirable. In this contribution, we present a general approach for computing the photoluminescence lifetimes and efficiencies of Ir­(III) complexes by considering all possible competing excited-state deactivation processes and importantly explicitly including the strongly temperature-dependent ones. This approach is based on the combination of state-of-the-art quantum chemical calculations and excited-state decay rate formalism with kinetic modeling, which is shown to be an efficient and reliable approach for a broad palette of Ir­(III) complexes, i.e., from yellow/orange to deep-blue emitters

    Enantioselective Conjugate Addition Catalyzed by a Copper Phosphoramidite Complex: Computational and Experimental Exploration of Asymmetric Induction

    No full text
    The stereochemical role of the phosphoramidite ligand in the asymmetric conjugate addition of alkylzirconium species to cyclic enones has been established through experimental and computational studies. Systematic, synthetic variation of the modular ligand established that the configuration of the binaphthol backbone is responsible for absolute stereocontrol, whereas modulation of the amido substituents leads to dramatic variations in the level of asymmetric induction. Chiral amido substituents are not required for enantioselectivity, leading to the discovery of a new family of easily synthesized phosphoramidites based on achiral amines that deliver equal levels of selectivity to Feringa’s ligand. A linear correlation between the length of the aromatic amido groups and experimentally determined enantioselectivity was uncovered for this class of ligand, which, following an optimization, led to highly selective ligands (up to 94% ee) with naphthyl rather than phenyl groups. An electronic effect of sterically similar aromatic substituents was investigated through NMR and DFT studies, showing that electron-rich aryl groups allow better Cu coordination. An interaction between the metal center and an aromatic group is responsible for this enhanced affinity and leads to a more tightly coordinated transition structure, leading to the major enantiomer. These studies illustrate the use of parametric quantitative structure–selectivity relationships to generate mechanistic models for asymmetric induction and catalyst structures that may be further probed by experiment and computation. This integrated approach leads to the rational modification of chiral ligands to achieve enhanced levels of selectivity

    Tropomyosin-1 acts as a potential tumor suppressor in human oral squamous cell carcinoma

    No full text
    <div><p>It is widely accepted that oral squamous cell carcinoma (OSCC) is a major contributor to the incidence and mortality of neck and head cancer. Tropomyosin-1 (TPM1), which is expressed at a low level, has been considered a prominent tumor-suppressing gene in a variety of solid tumors, although the precise mechanism of the TPM1 gene in OSCC progression remains unknown. We found that TPM1 expression levels decreased in OSCC patients and OSCC cell lines. The overall and cancer-specific survival of patients who exhibited low TPM1 levels were inferior to those of patients who had high TPM1 levels. It was also found that OSCC patients who suffered from disease stageⅠ-Ⅱ were more likely to have an up-regulated TPM1 expression level, and OSCC patients with lymph node metastasis had a higher probability of exhibiting reduced TPM1 expression. We show that overexpression of TPM1 can promote cell apoptosis and inhibit migration. Our results suggest that TPM1 can suppress tumors in OSCC, and the TPM1 expression level is related to OSCC patient prognosis.</p></div

    Detailed Mechanistic Studies on Palladium-Catalyzed Selective C–H Olefination with Aliphatic Alkenes: A Significant Influence of Proton Shuttling

    No full text
    Directing group-assisted regioselective C–H olefination with electronically biased olefins is well studied. However, the incorporation of unactivated olefins has remained largely unsuccessful. A proper mechanistic understanding of olefination involving unactivated alkenes is therefore essential for enhancing their usage in future. In this Article, detailed experimental and computational mechanistic studies on palladium catalyzed C–H olefination with unactivated, aliphatic alkenes are described. The isolation of Pd­(II) intermediates is shown to be effective for elucidating the elementary steps involved in catalytic olefination. Reaction rate and order determination, control experiments, isotopic labeling studies, and Hammett analysis have been used to understand the reaction mechanism. The results from these experimental studies implicate β-hydride elimination as the rate-determining step and that a mechanistic switch occurs between cationic and neutral pathway. Computational studies support this interpretation of the experimental evidence and are used to uncover the origins of selectivity
    corecore