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1.
Small ; : e2311193, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38739093

RESUMEN

LiB alloy is promising lithium (Li) metal anode material because the continuous internal LiB fiber skeleton can effectively suppress Li dendrites and structural pulverization. However, the unvalued surface states limit the practical application of LiB alloy anodes. Herein, the study examined the influence of the different exposure manners of the internal LiB fiber skeleton owing to the various surface states of the LiB alloy anode on electrochemical performance and targetedly proposed a scalable friction coating strategy to construct a lithiated fumed silica (LFS) functional layer with abundant electrochemically active sites on the surface of the LiB alloy anode. The LFS significantly suppresses the inhomogeneous interfacial electrochemical behavior of the LiB alloy anode and enables the exposure of the internal LiB fiber skeleton in a homogeneously planar manner (LFS-LiB). Thus, a 0.5 Ah LFS-LiB||LiCoO2 (LCO) pouch cell exhibits a discharge capacity retention rate of 80% after 388 cycles. Moreover, a 6.15 Ah LFS-LiB||S pouch cell with 409.3 Wh kg-1 exhibits a discharge capacity retention rate of 80% after 30 cycles. In conclusion, the study findings provide a new research perspective for Li alloy anodes.

2.
Molecules ; 27(18)2022 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-36144868

RESUMEN

Proteins are the fundamental biological macromolecules which underline practically all biological activities. Protein-protein interactions (PPIs), as they are known, are how proteins interact with other proteins in their environment to perform biological functions. Understanding PPIs reveals how cells behave and operate, such as the antigen recognition and signal transduction in the immune system. In the past decades, many computational methods have been developed to predict PPIs automatically, requiring less time and resources than experimental techniques. In this paper, we present a comparative study of various graph neural networks for protein-protein interaction prediction. Five network models are analyzed and compared, including neural networks (NN), graph convolutional neural networks (GCN), graph attention networks (GAT), hyperbolic neural networks (HNN), and hyperbolic graph convolutions (HGCN). By utilizing the protein sequence information, all of these models can predict the interaction between proteins. Fourteen PPI datasets are extracted and utilized to compare the prediction performance of all these methods. The experimental results show that hyperbolic graph neural networks tend to have a better performance than the other methods on the protein-related datasets.


Asunto(s)
Redes Neurales de la Computación , Proteínas , Secuencia de Aminoácidos , Proteínas/metabolismo
3.
Carcinogenesis ; 42(8): 1079-1088, 2021 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-34223877

RESUMEN

Peanut agglutinin (PNA) is a carbohydrate-binding protein in peanuts that accounts for ~0.15% peanut weight. PNA is highly resistant to cooking and digestion and is rapidly detectable in the blood after peanut consumption. Our previous studies have shown that circulating PNA mimics the actions of endogenous galactoside-binding protein galectin-3 by interaction with tumour cell-associated MUC1 and promotes circulating tumour cell metastatic spreading. The present study shows that circulating PNA interacts with micro- as well as macro-vascular endothelial cells and induces endothelial secretion of cytokines MCP-1 (CCL2) and IL-6 in vitro and in vivo. The increased secretion of these cytokines autocrinely/paracrinely enhances the expression of endothelial cell surface adhesion molecules including integrins, VCAM and selectin, leading to increased tumour cell-endothelial adhesion and endothelial tubule formation. Binding of PNA to endothelial surface MCAM (CD146), via N-linked glycans, and subsequent activation of PI3K-AKT-PREAS40 signalling is here shown responsible for PNA-induced secretion of MCP-1 and IL-6 by vascular endothelium. Thus, in addition to its influence on promoting tumour cell spreading by interaction with tumour cell-associated MUC1, circulating PNA might also influence metastasis by enhancing the secretion of metastasis-promoting MCP-1 and IL-6 from the vascular endothelium.


Asunto(s)
Arachis , Citocinas/metabolismo , Metástasis de la Neoplasia/patología , Aglutinina de Mani/sangre , Animales , Moléculas de Adhesión Celular/metabolismo , Células Cultivadas , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Femenino , Humanos , Mediadores de Inflamación/metabolismo , Ratones , Ratones Endogámicos BALB C , Mucina-1/metabolismo , Aglutinina de Mani/farmacología , Transducción de Señal
4.
Bioconjug Chem ; 32(5): 1001-1007, 2021 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-33914520

RESUMEN

DNA encoded library (DEL) technology allows for rapid identification of novel small-molecule ligands and thus enables early-stage drug discovery. DEL technology is well-established, numerous cases of discovered hit molecules have been published, and the technology is widely employed throughout the pharmaceutical industry. Nonetheless, DEL selection results can be difficult to interpret, as library member enrichment may derive from not only desired products, but also DNA-conjugated byproducts and starting materials. Note that DELs are generally produced using split-and-pool combinatorial chemistry, and DNA-conjugated byproducts and starting materials cannot be removed from the library mixture. Herein, we describe a method for high-throughput parallel resynthesis of DNA-conjugated molecules such that byproducts, starting materials, and desired products are produced in a single pot, using the same chemical reactions and reagents as during library production. The low-complexity mixtures of DNA-conjugate are then assessed for protein binding by affinity selection mass spectrometry and the molecular weights of the binding ligands ascertained. This workflow is demonstrated to be a practical tool to triage and validate potential hits from DEL selection data.


Asunto(s)
ADN/química , Biblioteca de Genes , Espectrometría de Masas , Técnicas Químicas Combinatorias
5.
Chemistry ; 25(5): 1242-1248, 2019 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-30466183

RESUMEN

Inspired by polyvalency and its prevalence in nature, we developed an efficient synthetic route for accessing a large variety of multivalent and dual-cavity baskets from inexpensive and abundant starting materials. First, the cycloaddition of vinyl acetate to anthracene was optimized to, upon hydrolysis, give dibenzobarrelene derivative 6, which after five functional group transformations and then cyclotrimerization gave heptiptycene dodecaester 4 in an overall 17 % yield. Following that, compound 4 was converted into D3h symmetric 1, composed of two fused cavitands each holding three terminal alkynes at the rim for conjugation to functional molecules using the highly efficient CuAAC reaction. To survey the reactivity of hexavalent 1, we "clicked" 2-acetamido-2-deoxy-ß-d-glucopyranosyl azide 3,4,6-triacetate (carbohydrate), methoxypolyethylene glycol azide (PEG, Mn =2000; polymer) and benzyl azide (aromatic) to obtain hexavalent conjugates 12-14 in 50-79 % yields. In summary, dual-cavity 1 is an accessible, structurally-unique and hexavalent host that can be "clicked" to a variety of functional molecules for (a) combinatorial lead identification of drugs, (b) preparation of hierarchical soft materials and (c) design of selective chemosensors, scavengers, or supramolecular catalysts.


Asunto(s)
Química Clic , Preparaciones Farmacéuticas/química , Alquinos/química , Azidas/química , Catálisis , Cobre/química , Reacción de Cicloadición , Diseño de Fármacos , Conformación Molecular , Preparaciones Farmacéuticas/síntesis química
6.
J Biol Chem ; 292(20): 8381-8389, 2017 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-28364041

RESUMEN

The galactoside-binding protein galectin-3 is increasingly recognized as an important player in cancer development, progression, and metastasis via its interactions with various galactoside-terminated glycans. We have shown previously that circulating galectin-3, which is increased up to 30-fold in cancer patients, promotes blood-borne metastasis in an animal cancer model. This effect is partly attributable to the interaction of galectin-3 with unknown receptor(s) on vascular endothelial cells and causes endothelial secretion of several metastasis-promoting cytokines. Here we sought to identify the galectin-3-binding molecule(s) on the endothelial cell surface responsible for the galectin-3-mediated cytokine secretion. Using two different galectin-3 affinity purification processes, we extracted four cell membrane glycoproteins, CD146/melanoma cell adhesion molecule (MCAM)/MUC18, CD31/platelet endothelial cell adhesion molecule-1 (PECAM-1), CD144/VE-cadherin, and CD106/Endoglin, from vascular endothelial cells. CD146 was the major galectin-3-binding ligand and strongly co-localized with galectin-3 on endothelial cell surfaces treated with exogenous galectin-3. Moreover, galectin-3 bound to N-linked glycans on CD146 and induced CD146 dimerization and subsequent activation of AKT signaling. siRNA-mediated suppression of CD146 expression completely abolished the galectin-3-induced secretion of IL-6 and G-CSF cytokines from the endothelial cells. Thus, CD146/MCAM is the functional galectin-3-binding ligand on endothelial cell surfaces responsible for galectin-3-induced secretion of metastasis-promoting cytokines. We conclude that CD146/MCAM interactions with circulating galectin-3 may have an important influence on cancer progression and metastasis.


Asunto(s)
Galectina 3/metabolismo , Factor Estimulante de Colonias de Granulocitos/metabolismo , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Interleucina-6/metabolismo , Multimerización de Proteína , Antígenos CD/genética , Antígenos CD/metabolismo , Proteínas Sanguíneas , Antígeno CD146/genética , Antígeno CD146/metabolismo , Cadherinas/genética , Cadherinas/metabolismo , Galectina 3/genética , Galectinas , Factor Estimulante de Colonias de Granulocitos/genética , Células Endoteliales de la Vena Umbilical Humana/patología , Humanos , Interleucina-6/genética , Metástasis de la Neoplasia , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patología , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/genética , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/metabolismo
7.
Chem Rec ; 15(1): 233-51, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25351894

RESUMEN

This Personal Account summarizes the development of the design of hydrogen-bonding-driven aromatic foldamers and their applications in supramolecular chemistry. This account begins with a short, non-exhaustive description of the background in the study of hydrogen-bonded aromatic foldamers. The construction of foldamers from discrete aromatic residues, including amide, urea, hydrazide and 1,2,3-triazole units, is then described. In the following parts, the applications of such compact aromatic oligomers in supramolecular chemistry, including the development of acyclic receptors, the construction of hybrid helical sequences through intramolecular stacking, the promotion of the formation of covalently and noncovalently bonded macrocycles, the tuning of the mechanical properties of copolymers, and the regulation of the shuttling behavior of [2]rotaxanes and the controlled release of dye from reverse vesicles formed from them, are described. In the final part, the binding-induced folding of conformationally flexible aromatic amide oligomers and their self-binding are described.

8.
Carcinogenesis ; 35(12): 2815-21, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25326505

RESUMEN

Peanut agglutinin (PNA), which accounts for ~0.15% of the weight of the common peanut, is a carbohydrate-binding protein that binds the oncofoetal Thomsen-Friedenreich (TF) disaccharide (galactoseß1,3N-acetylgalactosamineα-) that is overexpressed by ~90% of human cancers. Previous studies have shown that PNA is highly resistant to cooking and digestion and rapidly enters the human blood circulation after peanut ingestion. This study investigates the hypothesis that PNA appearance in the circulation after peanut ingestion may mimic the actions of endogenous TF-binding human galectin-3 in metastasis promotion. It shows that PNA at concentrations similar to those found in blood circulation after peanut ingestion increases cancer cell heterotypic adhesion to the blood vascular endothelium and enhances the formation of tumour cell homotypic aggregates, two important steps in the metastasis cascade, and enhances metastasis in a mouse metastasis model. These effects of PNA are shown to result from its interaction with the cancer-associated TF disaccharide on the transmembrane mucin protein MUC1, causing MUC1 cell surface polarization that reveals underlying cell surface adhesion molecules. Thus, PNA appearance in the blood circulation after peanut ingestion mimics the actions of endogenous galectin-3 and promotes cancer cell metastatic spread by interaction with cancer-associated TF/MUC1. As metastasis accounts for the majority of cancer-associated fatality, regular consumption of peanuts by cancer patients would therefore be expected to have an adverse effect on cancer survival.


Asunto(s)
Neoplasias del Colon/metabolismo , Neoplasias del Colon/secundario , Endotelio Vascular/efectos de los fármacos , Galectina 3/metabolismo , Mucina-1/metabolismo , Aglutinina de Mani/farmacología , Animales , Anoicis/efectos de los fármacos , Apoptosis , Western Blotting , Adhesión Celular , Movimiento Celular , Proliferación Celular , Neoplasias del Colon/tratamiento farmacológico , Endotelio Vascular/metabolismo , Endotelio Vascular/patología , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Mucina-1/química , Mucina-1/genética , Metástasis de la Neoplasia , Aglutinina de Mani/sangre , ARN Interferente Pequeño/genética , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto
9.
ScientificWorldJournal ; 2014: 107918, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24587704

RESUMEN

We report the formation of carbyne polysulfide by coheating carbon containing carbyne moieties and elemental sulfur. The product is proved to have a sp2 hybrid carbon skeleton with polysulfide attached on it. The electrochemical performance of carbyne polysulfide as a novel cathode material for rechargeable magnesium batteries is firstly investigated. The material exhibits a high discharge capacity of 327.7 mAh g(-1) at 3.9 mA g(-1). These studies show that carbyne polysulfide is a promising candidate as cathode material for rechargeable Mg batteries if the capacity retention can be significantly improved.


Asunto(s)
Carbamatos/química , Suministros de Energía Eléctrica , Magnesio/química , Sulfuros/química , Electroquímica , Electrodos , Resonancia Magnética Nuclear Biomolecular , Espectrometría Raman , Temperatura , Difracción de Rayos X
10.
ACS Appl Mater Interfaces ; 16(1): 1578-1586, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38118050

RESUMEN

A lithium-sulfur (Li-S) battery is a promising candidate for an electrochemical energy-storage system. However, for a long time, it suffered from the "shuttle effect" of the intermediate products of soluble polysulfides and safety issues concerning the combustible liquid electrolyte and lithium anode. In this work, sulfide polyacrylonitrile (SPAN) is employed as a solid cycled cathode to resolve the "shuttle effect" fundamentally, a gel polymer electrolyte (GPE) based on poly(ethylene glycol) diacrylate (PEGDA) is matched to the SPAN cathode to minimize the safety concerns, and finally, a quasi-solid-state Li-SPAN battery is combined by an in situ thermal polymerization strategy to improve its adaptability to the existing battery assembly processes. The PEGDA-based GPE achieved at 60 °C for 40 min ensures little damage to the in situ battery, a good electrode-electrolyte interface, a high ionic conductivity of 6.87 × 10-3 S cm-1 at 30 °C, and a wide electrochemical window of 4.53 V. Ultimately, the as-prepared SPAN composite exerts a specific capacity of 1217.3 mAh g-1 after 250 cycles at 0.2 C with a high capacity retention rate of 89.9%. The combination of the SPAN cathode and in situ thermally polymerized PEGDA-based GPE provides a new inspiration for the design of Li-SPAN batteries with both high specific energy and high safety.

11.
Materials (Basel) ; 16(5)2023 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-36902999

RESUMEN

The analytical results of normal contact stiffness for mechanical joint surfaces are quite different from the experimental data. So, this paper proposes an analytical model based on parabolic cylindrical asperity that considers the micro-topography of machined surfaces and how they were made. First, the topography of a machined surface was considered. Then, the parabolic cylindrical asperity and Gaussian distribution were used to create a hypothetical surface that better matches the real topography. Second, based on the hypothetical surface, the relationship between indentation depth and contact force in the elastic, elastoplastic, and plastic deformation intervals of the asperity was recalculated, and the theoretical analytical model of normal contact stiffness was obtained. Finally, an experimental test platform was then constructed, and the numerical simulation results were compared with the experimental results. At the same time, the numerical simulation results of the proposed model, the J. A. Greenwood and J. B. P. Williamson (GW) model, the W. R. Chang, I. Etsion, and D. B. Bogy (CEB) model, and the L. Kogut and I. Etsion (KE) model were compared with the experimental results. The results show that when roughness is Sa 1.6 µm, the maximum relative errors are 2.56%, 157.9%, 134%, and 90.3%, respectively. When roughness is Sa 3.2 µm, the maximum relative errors are 2.92%, 152.4%, 108.4%, and 75.1%, respectively. When roughness is Sa 4.5 µm, the maximum relative errors are 2.89%, 158.07%, 68.4%, and 46.13%, respectively. When roughness is Sa 5.8 µm, the maximum relative errors are 2.89%, 201.57%, 110.26%, and 73.18%, respectively. The comparison results demonstrate that the suggested model is accurate. This new method for examining the contact characteristics of mechanical joint surfaces uses the proposed model in conjunction with a micro-topography examination of an actual machined surface.

12.
Artículo en Inglés | MEDLINE | ID: mdl-37889609

RESUMEN

Lithium-sulfur (Li-S) batteries hold great promise as next-generation high-energy storage devices owing to the high theoretical specific capacity of sulfur, but polysulfide shuttling and lithium dendrite growth remain key challenges limiting cycling life. In this work, we propose a polyacrylonitrile-derived asymmetric (PDA) separator to enhance Li-S battery performance by accelerating sulfur redox kinetics and guiding lithium plating and stripping. A PDA separator was constructed from two layers: the cathode-facing side consists of polyacrylonitrile nanofibers carbonized at 800 °C and doped with titanium nitride, which can achieve rapid polysulfide conversion via electrocatalysis to suppress their shuttling; the anode-facing side consists of polyacrylonitrile oxidized at 280 °C, on which the abundant electronegative groups guide uniform lithium ion plating and stripping. Li-S batteries assembled with the PDA separator exhibited enhanced rate performance, cycling stability, and sulfur utilization, retaining 426 mA h g-1 capacity at 1 C over 1000 cycles and 632 mA h g-1 at 4 C over 200 cycles. Attractively, the PDA separator showed high thermal stability, which could mitigate the risk of internal short circuits and thermal runaway. This work demonstrates an original path to addressing the most critical issues with Li-S batteries.

13.
Nanomaterials (Basel) ; 12(20)2022 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-36296742

RESUMEN

The shuttling effect of soluble lithium polysulfides (LiPSs) and the sluggish conversion kinetics of polysulfides into insoluble Li2S2/Li2S severely hinders the practical application of Li-S batteries. Advanced catalysts can capture and accelerate the liquid-solid conversion of polysulfides. Herein, we try to make use of bismuth tantalum oxide with oxygen vacancies as an electrocatalyst to catalyze the conversion of LiPSs by reducing the sulfur reduction reaction (SRR) nucleation energy barrier. Oxygen vacancies in Bi4TaO7 nanoparticles alter the electron band structure to improve instinct electronic conductivity and catalytic activity. In addition, the defective surface could provide unsaturated bonds around the vacancies to enhance the chemisorption capability with LiPSs. Hence, a multidimensional carbon (super P/CNT/Graphene) standing sulfur cathode is prepared by coating oxygen vacancies Bi4TaO7-x nanoparticles, in which the multidimensional carbon (MC) with micropores structure can host sulfur and provide a fast electron/ion pathway, while the outer-coated oxygen vacancies with Bi4TaO7-x with improved electronic conductivity and strong affinities for polysulfides can work as an adsorptive and conductive protective layer to achieve the physical restriction and chemical immobilization of lithium polysulfides as well as speed up their catalytic conversion. Benefiting from the synergistic effects of different components, the S/C@Bi3TaO7-x coin cell cathode shows superior cycling and rate performance. Even under a high level of sulfur loading of 9.6 mg cm-2, a relatively high initial areal capacity of 10.20 mAh cm-2 and a specific energy density of 300 Wh kg-1 are achieved with a low electrolyte/sulfur ratio of 3.3 µL mg-1. Combined with experimental results and theoretical calculations, the mechanism by which the Bi4TaO7 with oxygen vacancies promotes the kinetics of polysulfide conversion reactions has been revealed. The design of the multiple confined cathode structure provides physical and chemical adsorption, fast charge transfer, and catalytic conversion for polysulfides.

14.
Nanomaterials (Basel) ; 11(11)2021 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-34835649

RESUMEN

Lithium-sulfur (Li-S) batteries are deemed to be one of the most optimal solutions for the next generation of high-energy-density and low-cost energy storage systems. However, the low volumetric energy density and short cycle life are a bottleneck for their commercial application. To achieve high energy density for lithium-sulfur batteries, the concept of synergistic adsorptive-catalytic sites is proposed. Base on this concept, the TiN@C/S/Ta2O5 sulfur electrode with about 90 wt% sulfur content is prepared. TiN contributes its high intrinsic electron conductivity to improve the redox reaction of polysulfides, while Ta2O5 provides strong adsorption capability toward lithium polysulfides (LiPSs). Moreover, the multidimensional carbon structure facilitates the infiltration of electrolytes and the motion of ions and electrons throughout the framework. As a result, the coin Li-S cells with TiN@C/S/Ta2O5 cathode exhibit superior cycle stability with a decent capacity retention of 56.1% over 300 cycles and low capacity fading rate of 0.192% per cycle at 0.5 C. Furthermore, the pouch cells at sulfur loading of 5.3 mg cm-2 deliver a high areal capacity of 5.8 mAh cm-2 at low electrolyte/sulfur ratio (E/S, 3.3 µL mg-1), implying a high sulfur utilization even under high sulfur loading and lean electrolyte operation.

15.
ACS Appl Mater Interfaces ; 13(49): 58789-58798, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34865464

RESUMEN

The shuttle effects of polysulfide intermediates (LiPSs) and sluggish kinetics during sulfur reduction reaction (SRR) process severely exacerbate the electrochemical performances of Li-S batteries. Herein, a unique nanocatalyst comprising ß-NiOOH nanosheets uniformly implanted on the surface of carbon nanotubes (CNT@NiOOH) was designed and synthesized for sulfur cathodes. The ß-NiOOH nanosheets have great capability of adsorbing LiPSs as well as superior catalytic activity for accelerating LiPS conversion, providing a more efficient method to restrain shuttle effects and improve the kinetics of SRR. Moreover, the nanometer-scale epitaxial growth and uniform distribution of ß-NiOOH on CNTs provide a multidimensional catalytic skeleton with sufficient accessible active surfaces, unimpeded LiPS diffusion pathways, and resultant high utilization of active sites. Simultaneously, stable electron transportation pathways are also obtained by being synthesized on CNTs to avoid the faultiness of poor electron conductivity of ß-NiOOH. These conspicuous advantages contribute to fully exert the catalytic and LiPS anchoring potential of CNT@NiOOH, bringing about the ultralong cycle performance and excellent capacity reversibility at a high discharge rate. Reticular CNT@NiOOH frameworks are assembled with the sulfur composite materials (SCMs) by a self-assembly method, and a super-high capacity of 813.3 mA h g-1 after 400 cycles at 0.5 C with a small capacity degradation of 0.07% per cycle is achieved. Furthermore, the 3 A h pouch-type cell with the SCM/CNT@NiOOH cathode attains a super-high energy density of about 320 W h kg-1 and shows a superior capacity retention as high as 75.9% after 50 cycles at 0.2 C. This work provides a promising method to accelerate the SRR process and restrain the shuttle effects for practical long-life and high-capacity Li-sulfur batteries.

16.
Nanoscale ; 13(41): 17592-17602, 2021 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-34661594

RESUMEN

Li-S batteries are considered as one of the most promising battery systems because of their large theoretical capacity and high energy density. However, the "shuttle effect" of soluble polysulfides and sluggish electrochemical redox kinetics of Li-S batteries could cause a broken electrode structure and poor electrochemical performance. Herein, a high-performance and stable Li-S battery has been demonstrated by employing organo-polysulfide chain modified acetylene black (ABPS) as the coating layer on the separator. In addition to the traditional advantages of fast electron transport and polysulfide-interception ability of the carbon coating layer, the grafted organo-polysulfide chain endows the ABPS coating layer with permselectivity for lithium ion against polysulfides, electrocatalytic ability for the sluggish redox kinetics and self-repairing ability for the broken electrode. Hence, the battery prepared using an ABPS-coated separator delivers the best cycling performance (970 mA h g-1 at 0.2 C after 100 cycles) and rate performance (805 mA h g-1 at 2 C) as compared to the cells using acetylene black (AB)-coated or Celgard separators. Moreover, the Li-S battery prepared using an ABPS-coated separator exhibits a stable cycling performance at 1 C over 500 cycles with a low degradation of 0.04% per cycle, and a high coulombic efficiency (near 100%). Furthermore, as the sulfur loading was increased to 6.8 mg cm-2, the Li-S battery using the ABPS-coated separator still could deliver a high areal capacity of 6.03 mA h cm-2 with a low electrolyte/sulfur ratio (E/S = 4, µLelectrolyte mgS-1) after 170 cycles. Significantly, ABPS is an effective coating layer material for improving and stabilizing Li-S batteries.

17.
Chem Commun (Camb) ; 56(8): 1271-1274, 2020 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-31903456

RESUMEN

A dual-cavity basket 16-, holding six γ-aminobutyric acids at its termini, encapsulates variously sized aromatics 2-7+, including four anthracyclines (8+-11+), driven by the hydrophobic effect and hydrogen bonding (HB). In particular, the formation of stable (K = 1012 M-2) anthracycline complexes [(8+-11+)2⊂16-], assembled into nanoparticles, occurred with positive homotropic cooperativity (α = 4K2/K1 = 1.1 ± 0.3 × 102-1.3 ± 0.7 × 103) in PBS medium. Importantly, weakening the first binding event (K1, i.e. by removing HBs) turned the second one (K2) more favorable. The finding is of interest for developing cooperative nano-antidotes acting as biodetoxifying agents.


Asunto(s)
Antraciclinas/farmacología , Antídotos/farmacología , Antineoplásicos/farmacología , Nanoestructuras/química , Regulación Alostérica/efectos de los fármacos , Antraciclinas/síntesis química , Antraciclinas/química , Antídotos/síntesis química , Antídotos/química , Antineoplásicos/química , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Estructura Molecular
18.
Ying Yong Sheng Tai Xue Bao ; 30(10): 3572-3578, 2019 Oct.
Artículo en Zh | MEDLINE | ID: mdl-31621245

RESUMEN

To evaluate the effects of enhancement release of Chum salmon (Oncorhynchus keta) in Suifen River, the homing Chum salmon was monitored in Dongning section of Suifen River from 2012 to 2017. A total of 462 samples were collected, 41 samples out of which were tagged indivi-duals which were cut off adipose fin before they were released. The recapture rate and the effects of Chum salmon enhancement release were analyzed and evaluated based on the releasing information. The results showed that the entire recapture rate of Chum salmon from 2010 to 2012 was 0.295%, and the input-output ratio of enhancement release was 1:2.87. Both the tagged and non-tagged groups were composed of 1+ to 5+ age individuals, with the average age being 3.93 and 3.63 years, respectively. The fork length at 50% individuals reached sexual maturity (L50) was estimated using a logistic moderating function, which was 53.13 cm and 49.89 cm for tagged and non-tagged groups, respectively. Results from ARSS analysis showed that there was no significant difference in fork length growth between tagged and non-tagged groups, but a significant difference in sexual maturity ratio. Our results confirmed the positive effects of enhancement release on recovery of Chum salmon resource and provided suggestions for the enhancement release efforts.


Asunto(s)
Oncorhynchus keta , Animales , China , Ríos
19.
Chem Sci ; 10(22): 5678-5685, 2019 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-31293752

RESUMEN

In this study, we report the remarkable recognition and assembly characteristics of D 3h symmetric basket 1 6- containing two adjoining and nonpolar cavities with six biocompatible GABA residues at their northern and southern termini. From the results of experimental (1H NMR, fluorescence and UV-Vis spectroscopies) and computational (MM-MC/OPLS3e) investigations, we deduced that hexaanionic 1 6- captured two molecules of anticancer drug doxorubicin 2 + in water and accommodated them in its two deep cavities. The formation of stable 1 6-⊂2 2 2+ (K a = 3 × 1012 M-2) was accompanied by the exceptional homotopic cooperativity (α = 4K 2/K 1 = 112) in which K 1 = 3.2 ± 0.8 × 105 M-1 and K 2 = 9 ± 1 × 106 M-1. Furthermore, bolaamphiphilic 1 6-⊂2 2 2+ assembled into spherical nanoparticles (DLS, cryo-TEM and TEM) possessing 41% drug loading. The preorganization of abiotic receptor 1 6- and its complementarity to 2 + have been proposed to play a part in the positive cooperativity in which ten favorable noncovalent contacts (i.e. hydrogen bonds, salt bridges, C-H···π and π-π contacts) are formed between doxorubicin and the dual-cavity host. In the case of topotecan 3 +, however, the absence of multiple and favorable basket⊂drug interactions resulted in the predominant formation of a binary 1 6- ⊂ 3 + complex (K 1 = 2.12 ± 0.01 × 104 M-1) and the negative homotopic allostery (α ≪ 1). To summarize, our study lays out a roadmap for creating a family of novel, accessible and multivalent hosts capable of complexing anticancer agents in a cooperative manner. As basket⊂drug complexes organize into highly loaded nanoparticles, the reported soft material is amenable to the bottom-up construction of stimuli-responsive nanomedicine capable of effective scavenging and/or delivery of drugs.

20.
Waste Manag ; 100: 122-127, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31536922

RESUMEN

In the leather industry, considerable amounts of non-recyclable solid leather wastes (SLWs) are produced and accumulated in factories. In this work, the non-isothermal thermochemical analysis (TGA) test was used to analyse the thermal degradation behaviour of chromium-tanned leather shaving, which is one of the main SLWs. The pyrolysis experiments were carried out under nitrogen atmosphere from 30 to 800 °C at different heating rates of 5, 10, 15 and 20 °C/min. Three different kinetic models, including the Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS) and Kissinger methods, were used to calculate the kinetic parameters. The activation energy values calculated by FWO and KAS methods were 391.79 and 348.77 kJ/mol, respectively. In consideration of the high HHV (14.15 MJ/kg) and carbon productivity (10.15%), SLWs could represent a potential candidate material for bioenergy production and carbon preparation. These results could be used for the design of thermochemical conversion processes utilizing SLWs as feedstock.


Asunto(s)
Pirólisis , Residuos Sólidos , Calefacción , Cinética , Termogravimetría
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