Understanding the breakdown mechanisms of polymer-based dielectrics is critical to achieving high-density energy storage. Here a comprehensive phase-field model is developed to investigate the ...electric, thermal, and mechanical effects in the breakdown process of polymer-based dielectrics. High-throughput simulations are performed for the P(VDF-HFP)-based nanocomposites filled with nanoparticles of different properties. Machine learning is conducted on the database from the high-throughput simulations to produce an analytical expression for the breakdown strength, which is verified by targeted experimental measurements and can be used to semiquantitatively predict the breakdown strength of the P(VDF-HFP)-based nanocomposites. The present work provides fundamental insights to the breakdown mechanisms of polymer nanocomposite dielectrics and establishes a powerful theoretical framework of materials design for optimizing their breakdown strength and thus maximizing their energy storage by screening suitable nanofillers. It can potentially be extended to optimize the performances of other types of materials such as thermoelectrics and solid electrolytes.
This article is written to provide an up-to-date review of porphyrin-based materials used in organic solar cells (OSCs). During the past two decades, OSCs have been the subject of extensive research ...and significant efforts have been devoted to developing low-cost OSCs, and they are not far from commercialization. Porphyrin and its analogues have been successfully applied to different optoelectronic devices, especially attaining remarkable fame when applied in dye sensitized solar cells. Despite the initial failures of their application in OSCs, porphyrins still attract much attention because of their structural versatility and recently realized significant improvement. In this review, we focus on summarizing the recent progress in porphyrin-based photovoltaic materials, including polymers, dyads, triads, small-molecules, and so on. We hope this paper could provide an in-depth study on the structure-property-performance relationship and provide a guideline for the further development of porphyrin-based and even other photovoltaic materials.
This article is written to provide an up-to-date review of porphyrin-based materials used in organic solar cells (OSCs).
Herein, an environmentally friendly electrochemical approach is reported that takes advantage of the captodative effect and delocalization effect to generate nitrogen‐centered radicals (NCRs). By ...changing the reaction parameters of the electrode material and feedstock solubility, dearomatization enabled a selective dehydrogenative C−N versus N−N bond formation reaction. Hence, pyrido1,2‐abenzimidazole and tetraarylhydrazine frameworks were prepared through a sustainable transition‐metal‐ and exogenous oxidant‐free strategy with broad generality. Bioactivity assays demonstrated that pyrido1,2‐abenzimidazoles displayed antimicrobial activity and cytotoxicity against human cancer cells. Compound 21 exhibited good photochemical properties with a large Stokes shift (approximately 130 nm) and was successfully applied to subcellular imaging. A preliminary mechanism investigation and density functional theory (DFT) calculations revealed the possible reaction pathway.
Tunable C−N versus N−N bond formation of nitrogen‐centered radicals was achieved by an electrochemical dehydrogenative dearomatization strategy. Control experiments, DFT calculations, and investigations of the electrode material elucidated the origin of the chemoselectivity. Bioactivity assays demonstrated that pyrido1,2‐abenzimidazoles displayed antimicrobial activity and cytotoxicity against human cancer cells.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Since bacterial infections seriously threaten human's health, considerable attention is devoted to the design of nanoscale antibacterial materials. Among them, metal nanoparticles cannot meet the ...requirements of durable antibacterial effects and are harmful to biological environments. In this study, environmentally friendly nanogels with durable antibacterial and antiadhesion properties are prepared by copolymerization of styrene, polycaprolactone‐hydroxyethyl methacrylate, and polyhexamethylene guanidine hydrochloride methacrylate. The resultant nanogels possess regular spherical morphologies with the size of about 200 nm. The nanogels exhibit a strong ability to kill bacteria and the mechanism is different from that of conventional antibacterial agent loaded nanoparticles. In addition, anti‐infection experiments explored by a wound model confirm the nanogels have the capability to prevent infection. Furthermore, the nanogels grafted on the surface of cotton fibers display good thermal stability, which is essential for finishing of fabrics. The cotton fabrics finished with nanogels can prevent the adhesion of bacteria by enhancing the hydrophobicity and the bacteriostatic rate. The antibacterial fabrics against Staphylococcus aureus and Escherichia coli are still more than 86% active after 50 times of mechanical washing. The biocompatible nanogels are unleachable from the antibacterial fabrics which demonstrate that they are ideal candidates for durable and environmental‐friendly nanoscaled antimicrobial materials.
In this study, environmentally friendly nanogels with durable antibacterial and antiadhesion properties are prepared by copolymerization of guanidine groups based monomers. The resultant inherent guanidine spherical nanogels can kill bacteria effectively and have the capability to prevent infection. Furthermore, the nanogels grafted on cotton fibers display good thermal stability. The cotton fabrics finished with nanogels can prevent the adhesion of bacteria permanently.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Polymer‐based dielectrics are attracting increasing attention due to their high‐density energy storage. However, mitigating the heat generation in real capacitors has been a challenge. Here an ...electrothermal breakdown phase‐field model is developed to fundamentally understand the thermal effects on the dielectric breakdown of polymer‐based dielectrics in real capacitor configurations including the increase in the dielectric loss and the decrease in the breakdown strength. While both enhancing the thermal conductivity and reducing the electrical conductivity of the polymer nanocomposites can reduce the thermal effects, it is found that reducing the electrical conductivity is more effective. This work is expected to not only stimulate attention to the thermal effects in polymer‐based dielectrics but also provide a fundamental guidance to mitigate the heat‐induced deterioration of breakdown strength.
An electrothermal breakdown phase‐field model is developed to fundamentally understand the thermal effects on the breakdown behavior of polymer‐based dielectrics with different microstructures. The predicted temperature‐dependent breakdown strengths agree with the available experimental measurements. It is found that reducing the electrical conductivity is more effective than enhancing the thermal conductivity of the polymer nanocomposite to reduce the thermal effects.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
What confers invasive alien plants a competitive advantage over native plants remains open to debate. Many of the world’s worst invasive alien plants are clonal and able to share resources within ...clones (clonal integration), particularly in heterogeneous environments. Here, we tested the hypothesis that clonal integration benefits invasive clonal plants more than natives and thus confers invasives a competitive advantage.
Weselected five congeneric and naturally co-occurring pairs of invasive alien and native clonal plants in China, and grew pairs of connected and disconnected ramets under heterogeneous light, soil nutrient and water conditions that are commonly encountered by alien plants during their invasion into new areas.
Clonal integration increased biomass of all plants in all three heterogeneous resource environments. However, invasive plants benefited more from clonal integration than natives. Consequently, invasive plants produced more biomass than natives.
Our results indicate that clonal integration may confer invasive alien clonal plants a competitive advantage over natives. Therefore, differences in the ability of clonal integration could potentially explain, at least partly, the invasion success of alien clonal plants in areas where resources are heterogeneously distributed.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NMLJ, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Mitochondria, as essential and interesting organelles within the eukaryotic cells, play key roles in a variety of pathologies, and its abnormalities are closely associated with Alzheimer’s disease ...(AD) and other diseases. Studies have shown that the abnormal of viscosity and concentration of hydrogen peroxide in mitochondria were all associated with AD. Accordingly, the detection of viscosity and hydrogen peroxide in mitochondria has attracted great attention. However, it remains a great challenge to explore a single probe, which can dual-detect the viscosity and H2O2 in mitochondria. Herein, in two ways to prevent the twisted internal charge transfer (TICT) process, we designed and sythesized the first dual-detection fluorescent probe Mito-VH that can visualize viscosity and H2O2 in mitochondria with different fluorescence signals in living cells.
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IJS, KILJ, NUK, PNG, UL, UM
Background: Hepatocellular carcinoma (HCC) (about 85–90% of primary liver cancer) is particularly prevalent in China because of the high prevalence of chronic hepatitis B infection. HCC is the fourth ...most common malignancy and the third leading cause of tumor-related deaths in China. It poses a significant threat to the life and health of Chinese people. Summary: This guideline presents official recommendations of the National Health and Family Planning Commission of the People’s Republic of China on the surveillance, diagnosis, staging, and treatment of HCC occurring in China. The guideline was written by more than 50 experts in the field of HCC in China (including liver surgeons, medical oncologists, hepatologists, interventional radiologists, and diagnostic radiologists) on the basis of recent evidence and expert opinions, balance of benefits and harms, cost-benefit strategies, and other clinical considerations. Key Messages: The guideline presents the Chinese staging system, and recommendations regarding patients with HCC in China to ensure optimum patient outcomes.
Background Although success was achieved in the therapy for a minority of advanced lung adenocarcinoma (LUAD) patients, anti-programmed death 1 (PD1) resistance was found in most LUAD patients. Here, ...we aimed to uncover a potential role of exosomal circular RNAs (circRNAs) in LUAD refractory to PD1 blockade. Methods circRNA sequencing and qRT-PCR were performed to determine the level of exosomal circRNAs in LUAD patients subsequently treated with anti-PD1. Then, the RNA pulldown, RNA immunoprecipitation, mass spectrometry, chromatin immunoprecipitation, luciferase reporter assays, flow cytometry, RNA sequencing, and in vitro and in vivo models were used to uncover the biological functions and underlying mechanism of circZNF451 in LUAD anti-PD1 treatment resistance. Results circRNA sequencing and qRT-PCR identified the up-regulation of exosomal circZNF451 from LUAD patients with progressive disease (PD) compared to those with partial remission (PR) after PD1 blockade therapy. Furthermore, elevated circZNF451 was revealed to be associated with poor prognosis of LUAD patients. Additionally, exosomal circZNF451 was demonstrated to induce an anti-inflammatory phenotype in macrophages and exhaustion of cytotoxic CD8.sup.+ T cells, and enhanced TRIM56-mediated degradation of FXR1 to activate the ELF4-IRF4 pathway in macrophages. By transgenic mice, knockout of ELF4 in macrophages was found to rescue immunotherapy efficacy in tumors with high level of exosomal circZNF451. Conclusion Exosomal circZNF451 reshapes the tumor immune microenvironment by inducing macrophages polarization via the FXR1- ELF4-IRF4 axis and is a novel biomarker for predicting the sensitivity of PD1 blockade in LUAD. Keywords: Lung adenocarcinoma, PD1 blockade resistance, Exosomal circRNA, Immunotherapy
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Mesenchymal stem cells (MSCs) repair infarcted heart through paracrine mechanism. We sought to compare the effectiveness of MSCs and MSC-derived exosomes (MSC-Exo) in repairing infarcted hearts and ...to identify how MSC-Exo mediated cardiac repair is regulated. In a rat myocardial infarction model, we found that MSC-Exo inhibited cardiac fibrosis, inflammation, and improved cardiac function. The beneficial effects of MSC-Exo were significantly superior compared to that of MSCs. To explore the potential mechanisms underlying MSC-Exo’s effects, we performed several in vitro experiments and miRNA-sequence analysis. MSC-Exo stimulated cardiomyocyte H9C2 cell proliferation, inhibited apoptosis induced by H2O2, and inhibited TGF-β induced transformation of fibroblast cell into myofibroblast. Importantly, novel miRNA sequencing results indicated that MSC-Exo and MSCs have similar miRNA expression profile, which could be one of the reasons that MSC-Exo can replace MSCs for cardiac repair. In addition, the expression of several miRNAs from MSC-Exo was significantly different from that of MSCs, which may explain why MSC-Exo has better therapeutic effect than MSCs. In conclusion, this study demonstrates that MSC-Exo could be used alone to promote cardiac repair and are superior to MSCs in repairing injured myocardium.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
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