| 1. |
- Bai, Yang, et al.
(författare)
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Geometry design of tethered small-molecule acceptor enables highly stable and efficient polymer solar cells
- 2023
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Ingår i: Nature Communications. - : NATURE PORTFOLIO. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- With the power conversion efficiency of binary polymer solar cells dramatically improved, the thermal stability of the small-molecule acceptors raised the main concerns on the device operating stability. Here, to address this issue, thiophene-dicarboxylate spacer tethered small-molecule acceptors are designed, and their molecular geometries are further regulated via the thiophene-core isomerism engineering, affording dimeric TDY-alpha with a 2, 5-substitution and TDY-beta with 3, 4-substitution on the core. It shows that TDY-alpha processes a higher glass transition temperature, better crystallinity relative to its individual small-molecule acceptor segment and isomeric counterpart of TDY-beta, and amore stablemorphology with the polymer donor. As a result, the TDY-alpha based device delivers a higher device efficiency of 18.1%, and most important, achieves an extrapolated lifetime of about 35000 hours that retaining 80% of their initial efficiency. Our result suggests that with proper geometry design, the tethered small-molecule acceptors can achieve both high device efficiency and operating stability.
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| 2. |
- Gu, Yeqing, et al.
(författare)
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Consumption of ultraprocessed food and development of chronic kidney disease : the Tianjin Chronic Low-Grade Systemic Inflammation and Health and UK Biobank Cohort Studies
- 2023
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Ingår i: The American journal of clinical nutrition. - : Elsevier BV. - 1938-3207 .- 0002-9165. ; 117:2, s. 373-382
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundMany ultraprocessed food (UPF)-derived by-products may play a role in the development of chronic kidney disease (CKD). Although several studies have assessed the association of UPFs with kidney function decline or CKD in various countries, no evidence has been shown in China and the United Kingdom.ObjectivesThis study aims to evaluate the association between UPF consumption and risk of CKD in 2 large cohort studies from China and the United Kingdom.MethodsIn total, 23,775 and 102,332 participants without baseline CKD were enrolled in the Tianjin Chronic Low-Grade Systemic Inflammation and Health (TCLSIH) and UK Biobank cohort studies, respectively. Information on UPF consumption was obtained from a validated food frequency questionnaire in the TCLSIH and 24-h dietary recalls in the UK Biobank cohort. CKD was defined as an estimated glomerular filtration rate of ResultsAfter a median follow-up of 4.0 and 10.1 y, the incidence rates of CKD were around 1.1% and 1.7% in the TCLSIH and UK Biobank cohorts, respectively. The multivariable hazard ratio [95% confidence interval] of CKD across increasing quartiles (quartiles 1–4) of UPF consumption were 1 (reference), 1.24 (0.89, 1.72), 1.30 (0.91, 1.87), and 1.58 (1.07, 2.34) (P for trend = 0.02) in the TCLSIH cohort and 1 (reference), 1.14 (1.00, 1.31), 1.16 (1.01, 1.33), and 1.25 (1.09, 1.43) (P for trend < 0.01) in the UK Biobank cohort, respectively.ConclusionsOur finding indicated that higher UPF consumption is associated with a higher risk of CKD. Moreover, restricting UPF consumption may potentially benefit the prevention of CKD. Further clinical trials are required to clarify the causality.
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| 3. |
- Hu, Yanlei, et al.
(författare)
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Composites of Silk Nanofibrils and Metal-Organic Framework Nanosheets for Fluorescence-Based Sensing and UV Shielding
- 2023
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society. - 2574-0970. ; 6:7, s. 6046-6055
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Tidskriftsartikel (refereegranskat)abstract
- Silk fibroin, a widely used natural biopolymer, presents remarkable flexibility and biodegradability, making it of great interest as a polymer matrix for functional composite materials. Herein, composites of silk nanofibrils and metal-organic framework (MOF) nanosheets were successfully fabricated by a coincubation and coassembly process. Under heat incubation, silk fibroin self-assembled into one-dimensional nanofibrils, while MOF nanosheets simultaneously covered or wrapped on the silk nanofibrils in a water suspension. Transparent composite membranes were obtained from their water suspensions by the solution casting method. The regenerated silk nanofibrils formed a network structure, and the integrated MOF nanosheets (0.1 to 3.0 wt %) endowed the composites with aggregation-induced emission luminogen (AIEgen)-based fluorescence. The fluorescence intensity of the composites was significantly enhanced owing to the interfacial interactions between silk nanofibrils and MOF nanosheets. The composite membranes also offer excellent UV shielding while maintaining optical transparency in the visible spectrum. This work provides an efficient pathway to fabricate luminescent silk protein-based composites for functional materials such as fluorescence sensing and anticounterfeiting.
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| 4. |
- Jiang, Yuguang, et al.
(författare)
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Influences of interconnection structure on the flow and heat transfer behaviors of the hydrocarbon fuel in parallel SCRamjet regenerative cooling channels
- 2023
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Ingår i: Numerical Heat Transfer, Part A Applications. - : Informa UK Limited. - 1040-7782 .- 1521-0634. ; 84:11, s. 1273-1296
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Tidskriftsartikel (refereegranskat)abstract
- Regenerative cooling is of great significance to secure the thermal structure and promote the flight Mach number range of the SCRamjet. Interconnection structure (ICS) plays a key role in improving the coolant flow distribution and heat sink utilization. In this work, the flow and heat transfer behaviors of the hydrocarbon fuel in parallel regenerative cooling channels with ICS are numerically investigated. The ICS improves the flow distribution and alleviates the local heat transfer deterioration. The influences of ICS configuration mainly consist of two aspects: (a). inter-channel pressure communication; (b). transverse mass transfer. The maximum wall temperature falls by 117.48 K/6.96% with the ICS introduced. Different sizes and positions of ICS are also studied. ICS with too small size cannot provide enough space for pressure communication and transverse mass transfer. While ICS with too large size leads to local heat transfer deterioration. The optimal Ф value to achieve the lowest heated wall temperature is Ф = 5 in this work. Regarding the position of ICS, it affects the local heat transfer deterioration through flow distribution and thermal load distribution. Ps = 50% (ICS locates at the middle of the heated section) presents the optimal cooling effect in this work. At last, the ICS configurations are universal to different heat flux distributions. The maximum wall temperature (Case qf2) decreases by 137.72 K/8.15% compared with Case C1 (without ICS).
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| 5. |
- Koskela, Salla, et al.
(författare)
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An Oxidative Enzyme Boosting Mechanical and Optical Performance of Densified Wood Films
- 2023
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 19:17
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Tidskriftsartikel (refereegranskat)abstract
- Nature has evolved elegant ways to alter the wood cell wall structure through carbohydrate-active enzymes, offering environmentally friendly solutions to tailor the microstructure of wood for high-performance materials. In this work, the cell wall structure of delignified wood is modified under mild reaction conditions using an oxidative enzyme, lytic polysaccharide monooxygenase (LPMO). LPMO oxidation results in nanofibrillation of cellulose microfibril bundles inside the wood cell wall, allowing densification of delignified wood under ambient conditions and low pressure into transparent anisotropic films. The enzymatic nanofibrillation facilitates microfibril fusion and enhances the adhesion between the adjacent wood fiber cells during densification process, thereby significantly improving the mechanical performance of the films in both longitudinal and transverse directions. These results improve the understanding of LPMO-induced microstructural changes in wood and offer an environmentally friendly alternative for harsh chemical treatments and energy-intensive densification processes thus representing a significant advance in sustainable production of high-performance wood-derived materials.
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| 6. |
- Luo, Yifei, et al.
(författare)
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Technology Roadmap for Flexible Sensors
- 2023
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Ingår i: ACS Nano. - : American Chemical Society. - 1936-0851 .- 1936-086X. ; 17:6, s. 5211-5295
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Forskningsöversikt (refereegranskat)abstract
- Humans rely increasingly on sensors to address grand challenges and to improve quality of life in the era of digitalization and big data. For ubiquitous sensing, flexible sensors are developed to overcome the limitations of conventional rigid counterparts. Despite rapid advancement in bench-side research over the last decade, the market adoption of flexible sensors remains limited. To ease and to expedite their deployment, here, we identify bottlenecks hindering the maturation of flexible sensors and propose promising solutions. We first analyze challenges in achieving satisfactory sensing performance for real-world applications and then summarize issues in compatible sensor-biology interfaces, followed by brief discussions on powering and connecting sensor networks. Issues en route to commercialization and for sustainable growth of the sector are also analyzed, highlighting environmental concerns and emphasizing nontechnical issues such as business, regulatory, and ethical considerations. Additionally, we look at future intelligent flexible sensors. In proposing a comprehensive roadmap, we hope to steer research efforts towards common goals and to guide coordinated development strategies from disparate communities. Through such collaborative efforts, scientific breakthroughs can be made sooner and capitalized for the betterment of humanity.
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| 7. |
- Mastantuoni, Gabriella G.
(författare)
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Engineering of lignin in wood towards functional materials
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Through 270 million years of evolution, the finely tuned hierarchical structure of wood has been optimized for efficient nutrient transport and exceptional mechanical stability. Its distinctive orthotropic constitution can provide inspiration and design opportunities for the development of novel functional materials. In recent years, top-down modification approaches have adapted the wood structure for innovative applications, utilizing the hierarchical arrangement at different length scales. In doing so, preserving the structural integrity is of the essence.This thesis explores new top-down modification techniques for the functionalization and structural control of wood-based materials. With the intent of better preserving and utilizing the natural wood organization and native components, two different modification routes were explored on softwood Scots pine: complete lignin removal and in-situ lignin modification. Complete delignification was achieved through preventive crosslinking of the polysaccharide matrix, enhancing intercellular adhesion between tracheids and preventing the disintegration of the cellular arrangement after lignin removal. The second approach focused on chemical modification of lignin by sulfonation as an alternative to complete lignin removal, resulting in wood templates of high negative charge up to 375 µmol g-1 and with well-preserved residual lignin. Hot compression of the delignified wood veneers produced thin wood films with high optical transmittance of 71 % alongside exceptional tensile strength of 449 MPa and Young’s modulus of 50 GPa. Densification of lignin-retaining wood veneers yielded strong and transparent thin films with UV blocking ability. Additionally, these densified films could be easily recycled into discrete wood fibers. The integration of conductive polymers including poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and polypyrrole in in-situ sulfonated wood resulted in bio-composites with high conductivity up to 203 S m-1 and high pseudo-capacitance up to 38 mF cm-2, indicating that tailoring the wood chemistry and activating the redox activity of lignin by sulfonation are important strategies for the fabrication of composites with potential for sustainable energy applications. By tailoring both wood chemistry and morphology, a wood foam with unique microstructure, enhanced permeability, along with high ultimate strength of 9 MPa and Young’s modulus of 364 MPa was obtained. When combined with the conductive polymer PEDOT:PSS, the composite demonstrated uniform conductivity of 215 S m-1 and mechanoresponsive electrical resistance, showing promise in sensing and mechanoresponsive devices.Therefore, in-situ engineering of lignin proved to be a versatile toolkit to obtain wood templates of improved permeability and porosity, greater compliance to densification, and enhanced compatibility with conductive polymers.
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| 8. |
- Mastantuoni, Gabriella G., et al.
(författare)
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High-Strength and UV-Shielding Transparent Thin Films from Hot-Pressed Sulfonated Wood
- 2023
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Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485.
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Tidskriftsartikel (refereegranskat)abstract
- Wood is a high-strength lightweight material owing to its orthotropic cellular structure and composite-like constitution. In conventional fabrication of wood-derived functional materials, the removal of the potentially beneficial components, such as lignin and hemicellulose, often leads to the disruption of the native hierarchical wood structure. Herein, we developed a facile method of in situ wood sulfonation followed by hot pressing for pine veneers to prepare high-density transparent thin films with preserved wood components and the natural fiber alignment. An optimum lignin content of the hot-pressed films was found to be 20.6% where both mechanical and optical properties were significantly enhanced with a more dense and compact structure. The hot-pressed transparent wood films also showed UV-blocking capability and could be recycled into discrete wood fibers owing to the sulfonate groups endowed by the in situ sulfonation step. The unique combination of properties achieved for thin wood films marks an important step in engineering functional wood-based materials that utilize both the structure of aligned fibers and the complex components of natural wood.
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| 9. |
- Mastantuoni, Gabriella G., et al.
(författare)
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In Situ Lignin Sulfonation for Highly Conductive Wood/Polypyrrole Porous Composites
- 2023
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Ingår i: Advanced Materials Interfaces. - : Wiley. - 2196-7350. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- To address the rising need of sustainable solutions in electronic devices, the development of electronically conductive composites based on lightweight but mechanically strong wood structures is highly desirable. Here, a facile approach for the fabrication of highly conductive wood/polypyrrole composites through top-down modification of native lignin followed by polymerization of pyrrole in wood cell wall. By sodium sulfite treatment under neutral condition, sulfonated wood veneers with increased porosity but well-preserved cell wall structure containing native lignin and lignosulfonates are obtained. The wood structure has a content of sulfonic groups up to 343 µmol g−1 owing to in situ sulfonated lignin which facilitates subsequent oxidative polymerization of pyrrole, achieving a weight gain of polypyrrole as high as 35 wt%. The lignosulfonates in the wood structure act as dopant and stabilizer for the synthesized polypyrrole. The composite reaches a high conductivity of 186 S m−1 and a specific pseudocapacitance of 1.71 F cm−2 at the current density of 8.0 mA cm−2. These results indicate that tailoring the wood/polymer interface in the cell wall and activating the redox activity of native lignin by sulfonation are important strategies for the fabrication of porous and lightweight wood/conductive polymer composites with potential for sustainable energy applications.
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| 10. |
- Nokling-Eide, Katharina, et al.
(författare)
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Acid preservation of cultivated brown algae Saccharina latissima and Alaria esculenta and characterization of extracted alginate and cellulose
- 2023
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Ingår i: Algal Research. - : Elsevier BV. - 2211-9264. ; 71, s. 103057-
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Tidskriftsartikel (refereegranskat)abstract
- Cultivated brown algae represent an important potential source of carbohydrate polymers for packaging and other biobased materials. However, their exploitation is currently limited by a short harvest season and a lack of cost-effective and sustainable methods to preserve biopolymer quality. In the present study, cultivated Saccharina latissima (SL) and Alaria esculenta (AE) were preserved with formic acid at 4, 13 and 20 degrees C for up to 16 weeks prior to extraction and characterization of alginate and cellulose. The data show up to 40 % increased yield of alginate from preserved biomass compared with fresh and non-preserved biomass, primarily due to removal of minerals and other soluble compounds during the acid wash. Acid preservation and storage caused a reduction in alginate weight average molecular weight (Mw) that was mainly dependent on storage temperature and to a lesser extent on storage time; storage at 4 degrees C maintained the Mw of alginates at 350-500 kDa. Preservation had no effect on the guluronate block structure of the extracted alginates, but guluronic acid content and block length increased in the non-preserved samples, presumably due to enzymatic degradation of the alginate's M-rich re-gions. Preservation of the seaweed resulted in an increased cellulose yield compared with fresh and non -preserved biomass, again due to the biomass being reduced during acid wash. The molecular weight and crys-tallinity of cellulose were not altered by the process. Altogether our findings demonstrate that acid preservation at low temperatures can effectively stabilize seaweed biomass while preserving alginate and cellulose quality for biomaterials and other applications.
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