| 1. |
- Zhang, Weiyi, et al.
(författare)
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Poly(Ionic Liquid)-Derived Graphitic Nanoporous Carbon Membrane Enables Superior Supercapacitive Energy Storage
- 2019
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 13:9, s. 10261-10271
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Tidskriftsartikel (refereegranskat)abstract
- High energy/power density, capacitance, and long-life cycles are urgently demanded for energy storage electrodes. Porous carbons as benchmark commercial electrode materials are underscored by their (electro)chemical stability and wide accessibility, yet are often constrained by moderate performances associated with their powdery status. Here via controlled vacuum pyrolysis of a poly(ionic liquid) membrane template, advantageous features including good conductivity (132 S cm(-1) at 298 K), interconnected hierarchical pores, large specific surface area (1501 m(2) g(-1)), and heteroatom doping are realized in a single carbon membrane electrode. The structure synergy at multiple length scales enables large areal capacitances both for a basic aqueous electrolyte (3.1 F cm(-2)) and for a symmetric all-solid-state supercapacitor (1.0 F cm(-2)), together with superior energy densities (1.72 and 0.14 mW h cm(-2), respectively) without employing a current collector. In addition, theoretical calculations verify a synergistic heteroatom co-doping effect beneficial to the supercapacitive performance. This membrane electrode is scalable and compatible for device fabrication, highlighting the great promise of a poly(ionic liquid) for designing graphitic nanoporous carbon membranes in advanced energy storage.
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| 2. |
- Chang, Jian, et al.
(författare)
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Reduced Graphene Oxide-Poly (Ionic Liquid) Composite Films of High Mechanical Performance
- 2021
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Ingår i: Frontiers in materials. - : Frontiers Media SA. - 2296-8016. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Graphene and its derivatives are a classical group of two-dimensional (2D) building blocks possessing excellent mechanical and/or electrical properties in favor of preparing flexible electronic devices. Natural materials, such as nacre, provide inspiration and an exciting guideline for assembling 2D nanosheets into functional nanocomposites. In this context, despite recent advance, methods to assemble graphene-derived nanosheets into nanocomposites with the integrated enhancement of mechanical properties and electrical conductivity are eagerly pursued. Here, a rational design has been proposed and demonstrated, which utilizes synergistic supramolecular interactions between a polymeric additive and reduced graphene-oxide nanosheets to fabricate exceptional, integrated, strong, and tough nanocomposite films with high electrical conductivity. Such materials can be applied in areas such as, aerospace, artificial muscle, tissue engineering, and flexible electronics.
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| 3. |
- Chang, Jian, et al.
(författare)
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Ultratough and ultrastrong graphene oxide hybrid films via a polycationitrile approach
- 2021
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Ingår i: Nanoscale Horizons. - : Royal Society of Chemistry (RSC). - 2055-6764 .- 2055-6756. ; 6:4, s. 341-347
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Tidskriftsartikel (refereegranskat)abstract
- Graphene oxide (GO) is a classic two dimensional (2D) building block that can be used to develop high-performance materials for numerous applications, particularly in the energy and environmental fields. Currently, the precise assembly of GO nanosheets into macroscopic nanohybrids of superior strength and toughness is desirable, and faces challenges and trade-offs. Herein, we exploited the freshly established polycationitrile method as a powerful molecular crosslinking strategy to engineer ultratough and ultrastrong GO/polymer hybrid films, in which a covalent triazine-based network was constructed in a mild condition to reinforce the interface between GO nanosheets. The tensile strength and toughness reached 585 +/- 25 MPa and 14.93 +/- 1.09 MJ m(-3), respectively, which, to the best of our knowledge, are the current world records in all GO-based hybrid films. As an added merit of the tailor-made polymer crosslinker, the high mechanical performance can be maintained in large part at an extremely high relative humidity of 98%. This emerging interface-engineering approach paves a new avenue to produce integrated strong-and-tough 2D nanohybrid materials that are useful in aerospace, artificial muscle, energy harvesting, tissue engineering and more.
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| 4. |
- Dong, Zhiyue, et al.
(författare)
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A cationitrile sequence encodes mild poly(ionic liquid) crosslinking for advanced composite membranes
- 2020
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Ingår i: Materials Horizons. - : Royal Society of Chemistry (RSC). - 2051-6347 .- 2051-6355. ; 7:10, s. 2683-2689
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Tidskriftsartikel (refereegranskat)abstract
- Polymer crosslinking is crucial for the preparation and consolidation of hierarchical nano- and micro-structures, hybrid interfaces, and collective assemblies. Here, for the first time, we showed that a cation-methylene-nitrile (CMN) functionality sequence encoded within repeating units of poly(ionic liquid)s (PILs) allowed for mild cyclizations of nitriles, processes otherwise requiring high temperatures and harsh catalysts. These new reactions facilitated by the CMN sequence were readily translated into freestanding nanomembranes (similar to 19 nm in thickness) and nanocomposite membranes by treating the PILs with mild ammonia vapor (0.2 bar, 20 degrees C). These materials were observed to be stable in various solvents, at different pH levels, and even in boiling water, exhibiting exceptional mechanical strength and solar-thermal desalination performance. The sequence was easy to synthesize, transferable in copolymers, and applicable to various cations, such as imidazolium, pyridinium, and triazolium. We expect it to provide a molecular code promoting programmable polymer crosslinking and the formation of hybrid structures for sustainable energy and water applications.
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| 5. |
- Gao, Qi, et al.
(författare)
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The Association Between Branched-Chain Amino Acid Concentrations and the Risk of Autism Spectrum Disorder in Preschool-Aged Children
- 2024
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Ingår i: MOLECULAR NEUROBIOLOGY. - 0893-7648 .- 1559-1182. ; 61, s. 6031-6044
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Tidskriftsartikel (refereegranskat)abstract
- Several studies have linked branched-chain amino acid (BCAA) metabolism disorders with autism spectrum disorder (ASD), but the results have been inconsistent. The purpose of this study was to explore the association between BCAA concentrations and the risk of ASD. A total of 313 participants were recruited from two tertiary referral hospitals from May 2018 to July 2021. Concentrations of BCAAs in dried blood spots were analyzed using liquid chromatography-tandem mass spectrometry-based analysis. Multivariate analyses and restricted cubic spline models were used to identify the association between BCAAs and the risk of ASD, and a nomogram was developed by using multivariate logistic regression and the risk was determined by receiver operating characteristic curve analysis and calibration curve analysis. Concentrations of total BCAA, valine, and leucine/isoleucine were higher in the ASD group, and all of them were positively and non-linearly associated with the risk of ASD even after adjusting for potential confounding factors such as age, gender, body mass index, and concentrations of BCAAs (P < 0.05). The nomogram integrating total BCAA and valine showed a good discriminant AUC value of 0.756 (95% CI 0.676-0.835). The model could yield net benefits across a reasonable range of risk thresholds. In the stratified analysis, the diagnostic ability of the model was more pronounced in children older than 3 years. We provide evidence that increased levels of BCAAs are associated with the risk of ASD, and the nomogram model of BCAAs presented here can serve as a marker for the early diagnosis of ASD.
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| 6. |
- Tang, Qingquan, et al.
(författare)
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Templated synthesis of cyclic poly(ionic liquid)s
- 2019
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Ingår i: Reactive & functional polymers. - : Elsevier BV. - 1381-5148 .- 1873-166X. ; 138, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Charged cyclic polymers, e.g. cyclic DNAs and polypeptides, play enabling roles in organisms, but their synthesis was challenging due to the well-known polyelectrolyte effect. To tackle the challenge, we developed a templated method to synthesize a library of imidazolium and pyridinium based cyclic poly(ionic liquid)s. Cyclic templates, cyclic polyimidazole and poly(2-pyridine), were synthesized first through ring-closure method by light-induced Diels - Alder click reaction. Through quaternization of cyclic templates followed by anion metathesis, the cyclic poly(ionic liquid)s were synthesized, which paired with varied counter anions.
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| 7. |
- Yang, Zhenlin, et al.
(författare)
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Structural basis of ligand binding modes at the neuropeptide Y Y-1 receptor
- 2018
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 556:7702, s. 520-524
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Tidskriftsartikel (refereegranskat)abstract
- Neuropeptide Y (NPY) receptors belong to the G-protein-coupled receptor superfamily and have important roles in food intake, anxiety and cancer biology(1,2). The NPY-Y receptor system has emerged as one of the most complex networks with three peptide ligands (NPY, peptide YY and pancreatic polypeptide) binding to four receptors in most mammals, namely the Y-1, Y-2, Y-4 and Y-5 receptors, with different affinity and selectivity(3). NPY is the most powerful stimulant of food intake and this effect is primarily mediated by the Y-1 receptor (Y1R)(4). A number of peptides and small-molecule compounds have been characterized as Y1R antagonists and have shown clinical potential in the treatment of obesity(4), tumour(1) and bone loss(5). However, their clinical usage has been hampered by low potency and selectivity, poor brain penetration ability or lack of oral bioavailability(6). Here we report crystal structures of the human Y1R bound to the two selective antagonists UR-MK299 and BMS-193885 at 2.7 and 3.0 angstrom resolution, respectively. The structures combined with mutagenesis studies reveal the binding modes of Y1R to several structurally diverse antagonists and the determinants of ligand selectivity. The Y1R structure and molecular docking of the endogenous agonist NPY, together with nuclear magnetic resonance, photo-crosslinking and functional studies, provide insights into the binding behaviour of the agonist and for the first time, to our knowledge, determine the interaction of its N terminus with the receptor. These insights into Y1R can enable structure-based drug discovery that targets NPY receptors.
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| 8. |
- Yin, Mingjie, et al.
(författare)
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Highly sensitive and fast responsive fiber-optic modal interferometric pH sensor based on polyelectrolyte complex and polyelectrolyte self-assembled nanocoating
- 2011
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 399:10, s. 3623-3631
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Tidskriftsartikel (refereegranskat)abstract
- A new fiber-optic pH sensor is demonstrated by coating negatively charged polyelectrolyte complex (PEC-) nanoparticles, made of sodium carboxymethyl cellulose and poly(diallyldimethylammonium chloride) (PDDA), and positively charged PDDA on the surface of a thin-core fiber modal interferometer (TCFMI) with a layer-by-layer (LbL) electrostatic self-assembly method. The fabricated TCFMI pH sensor has different transmission dip wavelengths under different pH values and shows high sensitivities of 0.6 nm/pH unit and -0.85 nm/pH unit for acidic and alkaline solutions, respectively, and short response time of 30-50 s. The LbL electrostatic self-assembly process of a PEC-/PDDA multilayer is traced by quartz crystal microbalance and shows a fast thickness growth. Atomic force microscopy shows the root mean square (RMS) surface roughness of electrostatic self-assembly nanocoating of polyelectrolyte complex/polyelectrolyte is much higher than that of polyelectrolyte/polyelectrolyte due to the larger size of PEC- colloidal nanoparticles. The enhanced RMS surface roughness and thickness of the nanocoating can shorten the response time and raise the sensitivity of the TCFMI pH sensor, respectively. In addition, the TCFMI pH sensor has highly reversible performance and good durability.
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| 9. |
- Zhang, Weiyi, et al.
(författare)
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Porous Polyelectrolytes : The Interplay of Charge and Pores for New Functionalities
- 2018
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 57:23, s. 6754-6773
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Forskningsöversikt (refereegranskat)abstract
- The past decade has witnessed rapid advances in porous polyelectrolytes and there is tremendous interest in their synthesis as well as their applications in environmental, energy, biomedicine, and catalysis technologies. Research on porous polyelectrolytes is motivated by the flexible choice of functional organic groups and processing technologies as well as the synergy of the charge and pores spanning length scales from individual polyelectrolyte backbones to their nano-/micro-superstructures. This Review surveys recent progress in porous polyelectrolytes including membranes, particles, scaffolds, and high surface area powders/resins as well as their derivatives. The focus is the interplay between surface chemistry, Columbic interaction, and pore confinement that defines new chemistry and physics in such materials for applications in energy conversion, molecular separation, water purification, sensing/actuation, catalysis, tissue engineering, and nanomedicine.
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