The synthesis, reactions and medicinal applications of the 1,3,4-thiadiazole ring in solution and the solid phase were investigated. The physical and chemical properties of biosostere and the ...reactions of aromatic and heterocyclic hydrazides with triethyl orthoformate were also explored.
Competitive interactions drive critical ecological processes in plant communities. Yet, how competitive interactions are influenced by polyploidy that has a widespread incidence in plants remains ...largely unknown.
To evaluate the hypothesis of competitive asymmetry between polyploids and diploids, we competed tetraploid and diploid plants of perennial herbaceous Chrysanthemum indicum L. (Asteraceae) at different relative frequencies under contrasting soil water contents. We quantified the interaction intensity between competing plants of the same (intraploidy) and different ploidy levels (interploidy), and measured functional traits related to gas exchange and plant water use to understand the underlying mechanisms.
The stronger competitive effect of tetraploids on diploids than that of diploids on tetraploids provided evidence for the competitive asymmetry. As a stronger competitor, tetraploids were limited more by individuals of their own than by diploids. Such competitive asymmetry was not only maintained under reduced soil water content, but also translated into higher above‐ground biomass of tetraploids. Tetraploids showed more resource‐acquisitive traits than diploids under high soil water content and more resource‐conservative traits under reduced soil water content. As such, the higher trait plasticity in tetraploids than diploids likely explained the competitive asymmetry.
Synthesis. These results elucidate the nature and magnitude of species interactions between polyploid and diploid plants under changing environments and the underlying mechanisms, and provide important insights into the prevalence and persistence of polyploid plants under a changing climate.
These results elucidate the nature and magnitude of species interactions between polyploid and diploid plants under changing environments and the underlying mechanisms, and provide important insights into the prevalence and persistence of polyploid plants under a changing climate.
Designing well‐defined nanointerfaces is of prime importance to enhance the activity of nanoelectrocatalysts for different catalytic reactions. However, studies on non‐noble‐metal‐interface ...electrocatalysts with extremely high activity and superior stability at high current density still remains a great challenge. Herein, a class of Co3O4/Fe0.33Co0.66P interface nanowires is rationally designed for boosting oxygen evolution reaction (OER) catalysis at high current density by partial chemical etching of Co(CO3)0.5(OH)·0.11H2O (Co‐CHH) nanowires with Fe(CN)63−, followed by low‐temperature phosphorization treatment. The resulting Co3O4/Fe0.33Co0.66P interface nanowires exhibit very high OER catalytic performance with an overpotential of only 215 mV at a current density of 50 mA cm−2 and a Tafel slope of 59.8 mV dec−1 in 1.0 m KOH. In particular, Co3O4/Fe0.33Co0.66P exhibits an obvious advantage in enhancing oxygen evolution at high current density by showing an overpotential of merely 291 mV at 800 mA cm−2, much lower than that of RuO2 (446 mV). Co3O4/Fe0.33Co0.66P is remarkably stable for the OER with negligible current loss under overpotentials of 200 and 240 mV for 150 h. Theoretical calculations reveal that Co3O4/Fe0.33Co0.66P is more favorable for the OER since the electrochemical catalytic oxygen evolution barrier is optimally lowered by the active Co‐ and O‐sites from the Co3O4/Fe0.33Co0.66P interface.
Co3O4/Fe0.33Co0.66P interface nanowires are rationally designed and synthesized by a universal strategy of partial chemical etching of Co(CO3)0.5(OH)·0.11H2O nanowires with Fe(CN)63−, followed by low‐temperature phosphorization with NaH2PO2·H2O for boosting oxygen evolution.
All‐solid‐state lithium batteries (ASSLBs) are considered to be the next‐generation energy storage system, because of their overwhelming advantages in energy density and safety compared to ...conventional lithium ion batteries. Among various systems, garnet‐based ASSLBs are one of the most promising candidates. The advantages arise from the intrinsic properties of garnet electrolytes, especially the high shear modulus and wider electrochemical window compared to that of polymer and sulfide electrolytes, guaranteeing the application of Li metal and high voltage cathodes. However, the interfacial issues between garnets and electrodes (Li metal and cathodes) are challenging and hinder the further development of garnet‐based ASSLBs. Herein, the origin of interfacial resistance and recent development of interfacial construction in garnet‐based ASSLBs are reviewed, as well as the subsequent interfacial degradation and cell failure during cycling process, including inhomogeneous plating and stripping, Li dendrites, and strain induced microcracks in stiff electrodes. Finally, the future challenges and opportunities in this important and exciting field are also presented.
Garnet‐based all‐solid‐state lithium batteries will be promising next generation energy storage system once the interfacial issues are solved. The interfacial issues include the large interfacial resistance at the initial state and the mechanical degradation of both anodic and cathodic interfaces during the subsequent cycling process. Ingenious architecture design and advanced engineering technique can help to build a better all‐solid‐state lithium battery.
During HIV-1 infection, antibodies are generated against the region of the viral gp120 envelope glycoprotein that binds CD4, the primary receptor for HIV-1. Among these antibodies, VRC01 achieves ...broad neutralization of diverse viral strains. We determined the crystal structure of VRC01 in complex with a human immunodeficiency virus HIV-1 gp120 core. VRC01 partially mimics CD4 interaction with gp120. A shift from the CD4-defined orientation, however, focuses VRC01 onto the vulnerable site of initial CD4 attachment, allowing it to overcome the glycan and conformational masking that diminishes the neutralization potency of most CD4-binding-site antibodies. To achieve this recognition, VRC01 contacts gp120 mainly through immunoglobulin V-gene regions substantially altered from their genomic precursors. Partial receptor mimicry and extensive affinity maturation thus facilitate neutralization of HIV-1 by natural human antibodies.
Glycyrrhizic acid (GA), a triterpene isolated from the roots and rhizomes of licorice, named Glycyrrhiza glabra, is the principal bioactive ingredient of anti-viral, anti-inflammatory and ...hepatoprotective effects. GA has been used in the clinical treatment of hepatitis, bronchitis, gastric ulcer, AIDS (acquired immunodeficiency syndrome), certain cancers and skin diseases. It has a direct effect on anti-HBV (hepatitis B virus) via affecting the HBsAg (hepatitis B surface antigen) to extracellular secretion, improving liver dysfunction in patients with chronic hepatitis B, and ultimately improving the immune status of HBV. GA can significantly inhibit the proliferation of HIV, showing an immune activation. The clinical application of GA on the prevention and treatments of various diseases may derive from its numerous pharmacological properties. This review provides the summary of the antiviral effects of GA on research progress and mechanism in recent years.
Naturally occurring naphthoquinones, usually in forms of botanical extracts, have been implicated with human life since ancient time, far earlier than their isolation and identification in modern ...era. The long use history of naphthoquinones has witnessed their functional shift from the original purposes as dyes and ornaments toward medicinal benefits. Hitherto, numerous studies have been carried out to elucidate the pharmacological profile of both natural and artificial naphthoquinones. A number of entities have been identified with promising therapeutic potential. Apart from the traditional effects of wound healing, anti‐inflammatory, hemostatic, antifertility, insecticidal and antimicrobial, etc., the anticancer potential of naphthoquinones either in combination with other treatment approaches or on their own is being more and more realized. The molecular mechanisms of naphthoquinones in cells mainly fall into two categories as inducing oxidant stress by ROS (reactive oxygen species) generation and directly interacting with traditional therapeutic targets in a non‐oxidant mechanism. Based on this knowledge, optimized agents with naphthoquinones scaffold have been acquired and further tested. Hereby, we summarize the explored biological mechanisms of naphthoquinones in cells and review the application perspective of promising naphthoquinones in cancer therapies.
The explored biological mechanisms of naphthoquinones in cellular and the application perspective of promising naphthoquinones in cancer therapies were reviewed.
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Zinc (Zn) has recently emerged as a promising biodegradable metal thanks to its critical physiological roles and promising degradation behavior. However, cytocompatibility and ...antibacterial property of Zn is still suboptimal, in part, due to the excessive Zn ions released during degradation. Inspired by the calcium phosphate-based minerals in natural bone tissue, zinc phosphate (ZnP) coatings were prepared on pure Zn using a chemical conversion method in this study. The coating morphology was then optimized through controlling the pH of coating solution, resulting in a homogeneous micro-/nano-ZnP coating structure. The ZnP coating significantly increased the cell viability, adhesion, and differentiation of pre-osteoblasts and vascular endothelial cells, while significantly reduced the adhesion of the platelets and E. coli. Additionally, ZnP coating significantly reduced the Zn ion release from the bulk material during degradation process, resulting in a much lower Zn2+ concentration and pH change in the surrounding environment. The improved hemocompatibility, cytocompatibility and antibacterial performance of ZnP coated Zn biomaterials could be mainly attributed to the controlled Zn ion release and micro-/nano-scaled coating structure. Taken together, ZnP coating on Zn-based biomaterial appears to be a viable approach to enhance its biocompatibility and antibacterial property as well as to control its degradation rate.
Statement of Significance
Zn and its alloys are promising biodegradable implant materials for orthopedic and cardiovascular applications. However, notable cytotoxicity has been reported due to degradation products accumulated in the local environment, largely overdosed Zn2+. Thus, controlling burst Zn2+ release is the key to minimize the toxicity of Zn implants. To achieve this goal, we prepared a homogenous ZnP coating on Zn metals thanks to its easy synthesis, stable chemical property, and good biocompatibility. Results showed that ZnP not only improved the cell viability, adhesion and proliferation, but also significantly reduced the attachment of platelet and bacterial. Therefore, ZnP could be a promising approach to improve the functional performance of Zn-based implants, and potentially be applied to many other medical implants.
Landslides represent a part of the cascade of geological hazards in a wide range of geo-environments. In this study, we aim to investigate and compare the performance of two state-of-the-art machine ...learning models, i.e., decision tree (DT) and random forest (RF) approaches to model the massive rainfall-triggered landslide occurrences in the Izu-Oshima Volcanic Island, Japan at a regional scale. At first, a landslide inventory map is prepared consisting of 44 landslide polygons (10,444 pixels) from aerial photo-interpretation and field surveys. To estimate the robustness of the models, we randomly adapted two different samples (S1 and S2), comprising of both positive and negative cells (70% of total landslides - 7293 pixels) for training and remaining (30%–3151 pixels) for validation. Twelve causative factors including altitude, slope angle, slope aspect, plan curvature, total curvature, compound topographic index, stream power index, distance to drainage network, drainage density, distance to geological boundaries, lithology and cumulative rainfall were selected as predictors to implement the landslide susceptibility model. The area under the receiver operating characteristics (ROC) curves (AUC) and other statistical signifiers were used to verify the model accuracies. The result shows that the DT and RF models achieved remarkable predictive performance (AUC > 0.9), producing near accurate susceptibility maps. The overall efficiency of RF (AUC = 0.956) is found significantly higher than the DT (AUC = 0.928) results. Additionally, we noticed that the performance of RF for modeling landslide susceptibility is very robust even though the training and validation samples are altered. Considering the performances, we suggest that both RF and DT models can be used in other similar non-eruption-related landslide studies in the tephra-deposited rich volcanoes, as they are capable of rapidly generating accurate and stable LSM maps for risk mitigation, management practices, and decision-making. Moreover, the RF-based model is promising and enough to be recommended as a method to map regional landslide susceptibility.
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•Decision tree and random forest models applied to map landslide-prone areas in a volcanic Island.•Two sample set (S1, and S2) for computing the robustness of the model•LSM maps were compared using different assessment principles.•Random forest performs better on both samples with AUC > 0.9.
A series of bio-based plasticizers based on isosorbide, a renewable monomer derived from glucose, were successfully synthesized. The chemical structures of the synthesized isosorbide diesters with ...different alkyl chain length were confirmed by FTIR and 1H NMR. The influence of varying alkyl chain length on thermal and mechanical properties of isosorbide diesters in poly(vinyl chloride) (PVC) was investigated in detail. It was found that the plasticizing efficiency of isosorbide diester decreased as the alkyl chain length increased, reflecting on the gradually increased Tg and the decreased elongation at break of PVC blend. However, the longer alkyl chain length of isosorbide diester improved the thermal stability of PVC blend and simultaneously depressed its volatility from PVC. Besides, the bio-based isosorbide diesters rivaled those petro-based phthalates, and they could be potential candidates to replace phthalates in the future industry.
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•Isosorbide diesters with varying alkyl chain length were evaluated as bio-based alternatives to petro-based phthalates.•The plasticizing efficiency of isosorbide diesters were in the order of dibutyrate > dihexanoate > dioctanoate > didecanoate.•The thermostability of isosorbide diesters followed the order of dibutyrate < dihexanoate < dioctanoate < didecanoate.•The isosorbide diester with longer alkyl chain length is more difficult to volatilize.
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