| 1. |
- Chen, Song, et al.
(författare)
-
Novel Fast-Setting Mineral Trioxide Aggregate : Its Formulation, Chemical-Physical Properties, and Cytocompatibility
- 2018
-
Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 10:24, s. 20334-20341
-
Tidskriftsartikel (refereegranskat)abstract
- One of the main drawbacks that limits the application of mineral trioxide aggregate (MTA) in dental field is its long setting time. Mineral trioxide aggregate with accelerated setting properties and excellent chemical-physical and biological properties is still required. In this study, an innovative mineral trioxide aggregate, which consists of calcium silicates, calcium aluminates, and zirconium oxide, was designed to obtain fast-setting property. The optimized formulation can achieve initial setting in 10 min and final setting in 15 min, which are much faster than commercial mineral trioxide aggregate. In addition, the optimized fast-setting MTA showed adequate radiopacity and good biocompatibility. The ion concentrations after storage in water for 1 day were 52.3 mg/L Ca, 67.7 mg/L Al, 48.8 mg/L Si, and 11.7 mg/L Mg. The hydration products of hardened cements were investigated by X-ray diffraction, scanning electron microscopy, and Fourier transform infrared, showing the accelerated setting time was due to the formation of honeycomb-like calcium silicate hydrate gel. The novel MTA could be a promising material for dental applications.
|
|
| 2. |
- Lin, Shangrong, et al.
(författare)
-
Underestimated Interannual Variability of Terrestrial Vegetation Production by Terrestrial Ecosystem Models
- 2023
-
Ingår i: Global Biogeochemical Cycles. - 0886-6236. ; 37:4
-
Tidskriftsartikel (refereegranskat)abstract
- Vegetation gross primary production (GPP) is the largest terrestrial carbon flux and plays an important role in regulating the carbon sink. Current terrestrial ecosystem models (TEMs) are indispensable tools for evaluating and predicting GPP. However, to which degree the TEMs can capture the interannual variability (IAV) of GPP remains unclear. With large data sets of remote sensing, in situ observations, and predictions of TEMs at a global scale, this study found that the current TEMs substantially underestimate the GPP IAV in comparison to observations at global flux towers. Our results also showed the larger underestimations of IAV in GPP at nonforest ecosystem types than forest types, especially in arid and semiarid grassland and shrubland. One cause of the underestimation is that the IAV in GPP predicted by models is strongly dependent on canopy structure, that is, leaf area index (LAI), and the models underestimate the changes of canopy physiology responding to climate change. On the other hand, the simulated interannual variations of LAI are much less than the observed. Our results highlight the importance of improving TEMs by precisely characterizing the contribution of canopy physiological changes on the IAV in GPP and of clarifying the reason for the underestimated IAV in LAI. With these efforts, it may be possible to accurately predict the IAV in GPP and the stability of the global carbon sink in the context of global climate change.
|
|
| 3. |
- Liu, Liyang, 1990-, et al.
(författare)
-
Solventless Amination of Lignin and Natural Phenolics using 2-Oxazolidinone
- 2023
-
Ingår i: ChemSusChem. - : Wiley. - 1864-5631 .- 1864-564X. ; 16:15
-
Tidskriftsartikel (refereegranskat)abstract
- Reactive amine compounds are critical for a vast array of useful chemicals in society, yet a limited number of them are derived from renewable resources. This study developed an efficient route to obtain aminated building blocks from phenolic resources derived from nature, such as lignin and tannic acid, for enhancing their utility in applications such as epoxy resins, nylons, polyurethanes, and other polymeric materials. The reaction utilized a carbon storage compound, 2-oxazolidinone as a solvent and as a reagent circumventing the need of hazardous chemistry of conventional amination routes such as those involving formaldehyde. Both free acids and hindered phenolics were readily converted into aminoethyl derivatives resulting in aromatics with primary amine functionality. The aminated compounds, with the potential for enhanced reactivity, can pave the way toward more advanced renewable building blocks.
|
|
| 4. |
- Luo, Jing, et al.
(författare)
-
Strong and Multifunctional Lignin/Liquid Metal Hydrogel Composite as Flexible Strain Sensors
- 2024
-
Ingår i: ACS Sustainable Chemistry & Engineering. - 2168-0485. ; 12:18, s. 7105-7114
-
Tidskriftsartikel (refereegranskat)abstract
- Conductive hydrogel is a promising material for flexible sensors due to its good electrical conductivity, adhesion, and high sensitivity. However, the challenge of integrating conductive fillers like liquid metals lies in their poor interface compatibility, which adversely affects their mechanical strength and lifespan. Addressing the challenge of achieving both mechanical strength and conductivity, this study harnessed 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO)-oxidized lignin to form a stable interface between the liquid metal (LM) and the hydrogel system. Furthermore, this innovation (lignin-LM) facilitates the free radical polymerization of acrylic acid (PAA) at room temperature, resulting in conductive hydrogels. These hydrogels demonstrated excellent self-healing, adhesive, tensile, and antibacterial properties, alongside high strain sensing accuracy and stable electrical output in flexible sensor applications. In conclusion, the PAA-Lignin-LM hydrogel holds excellent promise for wearable, flexible electronic products, introducing a novel approach for the high-value utilization of lignin.
|
|
| 5. |
- Paleti, Sri Harish Kumar, et al.
(författare)
-
Hexanary blends : a strategy towards thermally stable organic photovoltaics
- 2023
-
Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 14:1
-
Tidskriftsartikel (refereegranskat)abstract
- Non-fullerene based organic solar cells display a high initial power conversion efficiency but continue to suffer from poor thermal stability, especially in case of devices with thick active layers. Mixing of five structurally similar acceptors with similar electron affinities, and blending with a donor polymer is explored, yielding devices with a power conversion efficiency of up to 17.6%. The hexanary device performance is unaffected by thermal annealing of the bulk-heterojunction active layer for at least 23 days at 130 °C in the dark and an inert atmosphere. Moreover, hexanary blends offer a high degree of thermal stability for an active layer thickness of up to 390 nm, which is advantageous for high-throughput processing of organic solar cells. Here, a generic strategy based on multi-component acceptor mixtures is presented that permits to considerably improve the thermal stability of non-fullerene based devices and thus paves the way for large-area organic solar cells.
|
|
| 6. |
- Shi, Tingting, et al.
(författare)
-
The super-pangenome of Populus unveils genomic facets for its adaptation and diversification in widespread forest trees
- 2024
-
Ingår i: Molecular Plant. - : Elsevier. - 1674-2052 .- 1752-9867. ; 17:5, s. 725-746
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding the underlying mechanisms and links between genome evolution and adaptive innovations stands as a key goal in evolutionary studies. Poplars, among the world's most widely distributed and cultivated trees, exhibit extensive phenotypic diversity and environmental adaptability. In this study, we present a genus-level super-pangenome comprising 19 Populus genomes, revealing the likely pivotal role of private genes in facilitating local environmental and climate adaptation. Through the integration of pangenomes with transcriptomes, methylomes, and chromatin accessibility mapping, we unveil that the evolutionary trajectories of pangenes and duplicated genes are closely linked to local genomic landscapes of regulatory and epigenetic architectures, notably CG methylation in gene-body regions. Further comparative genomic analyses have enabled the identification of 142 202 structural variants across species that intersect with a significant number of genes and contribute substantially to both phenotypic and adaptive divergence. We have experimentally validated a ∼180-bp presence/absence variant affecting the expression of the CUC2 gene, crucial for leaf serration formation. Finally, we developed a user-friendly web-based tool encompassing the multi-omics resources associated with the Populus super-pangenome (http://www.populus-superpangenome.com). Together, the present pioneering super-pangenome resource in forest trees not only aids in the advancement of breeding efforts of this globally important tree genus but also offers valuable insights into potential avenues for comprehending tree biology.
|
|
| 7. |
- Wan, Liyang, et al.
(författare)
-
A Mild CO2 Etching Method To Tailor the Pore Structure of Platinum-Free Oxygen Reduction Catalysts in Proton Exchange Membrane Fuel Cells
- 2021
-
Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 13:38, s. 45661-45669
-
Tidskriftsartikel (refereegranskat)abstract
- The structural tailoring of pores is essential to high-performance Fe/N/C electrocatalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells. Current strategies for pore structure engineering are usually accompanied with a drastic change of the intrinsic activity-related surface, which may mask the real effects of the porous structure on ORR activity. Herein, a mild carbon dioxide (CO2) etching method was used to flexibly tailor the pore structure of Fe/N/C electrocatalysts without drastic changes in their surface structure and property. In this way, via employing the Fe/N/C electrocatalysts as a model, the intrinsic impact of the pore structure on ORR activity was revealed. In addition, the CO2 etching method developed a high-quality electrocatalyst (sample Fe/N/C–5% CO2) with polarization performance exceeding that of the commercial Pt/C catalyst in the fuel cell working voltage region (>0.65 V). This work will promote the ongoing intensive studies on the rational design of the pore structures in the Fe/N/C electrocatalysts.
|
|
