| 1. |
- Cao, Hongwei, et al.
(författare)
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Mechanistic insights into the changes of enzyme activity in food processing under microwave irradiation
- 2023
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Ingår i: Comprehensive Reviews in Food Science and Food Safety. - : John Wiley & Sons. - 1541-4337. ; 22:3, s. 2465-2487
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Forskningsöversikt (refereegranskat)abstract
- Microwave (MW) and enzyme catalysis are two emerging processing tools in the field of food industry. Recently, MW has been widely utilized as a novel type of green and safe heating energy. However, the effect of MW irradiation on enzyme activity is not described clearly. The intrinsic mechanisms behind enzyme activation and inactivation remain obscure. To apply better MW to the field of enzyme catalysis, it is essential to gain insights into the mechanism of MW action on enzyme activity. This review summarizes the changes in various enzyme activity during food processing, especially under MW irradiation. The intrinsic mechanism of thermal and nonthermal effects of MW irradiation was analyzed from the perspective of enzyme reaction kinetics and spatial structure. MW irradiation temperature is a vital parameter affecting the catalytic activity of enzymes. Activation of the enzyme activity is achieved even at high MW power when the enzyme is operating at its optimum temperature. However, when the temperature exceeds the optimum temperature, the enzyme activity is inhibited. In addition to MW dielectric heating effect, nonthermal MW effects also alter the microenvironment of reactive system. Taken together, enzyme activity is influenced by both thermal and nonthermal MW effects.
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| 2. |
- Cao, Xuan, et al.
(författare)
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Engineering yeast for high-level production of diterpenoid sclareol
- 2023
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Ingår i: Metabolic Engineering. - : Elsevier BV. - 1096-7176 .- 1096-7184. ; 75, s. 19-28
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Tidskriftsartikel (refereegranskat)abstract
- The diterpenoid sclareol is an industrially important precursor for alternative sustainable supply of ambergris. However, its current production from plant extraction is neither economical nor environmental-friendly, since it requires laborious and cost-intensive purification procedures and plants cultivation is susceptible to environmental factors. Engineering cell factories for bio-manufacturing can enable sustainable production of natural products. However, stringent metabolic regulation poses challenges to rewire cellular metabolism for overproduction of compounds of interest. Here we used a modular approach to globally rewire the cellular metabolism for improving sclareol production to 11.4 g/L in budding yeast Saccharomyces cerevisiae, the highest reported diterpenoid titer in microbes. Metabolic flux analysis showed that modular balanced metabolism drove the metabolic flux toward the biosynthesis of targeted molecules, and transcriptomic analysis revealed that the expression of central metabolism genes was shaped for a new balanced metabolism, which laid a foundation in extensive metabolic engineering of other microbial species for sustainable bio-production.
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| 3. |
- Davies, Stuart J., et al.
(författare)
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ForestGEO: Understanding forest diversity and dynamics through a global observatory network
- 2021
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Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207. ; 253
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Tidskriftsartikel (refereegranskat)abstract
- ForestGEO is a network of scientists and long-term forest dynamics plots (FDPs) spanning the Earth's major forest types. ForestGEO's mission is to advance understanding of the diversity and dynamics of forests and to strengthen global capacity for forest science research. ForestGEO is unique among forest plot networks in its large-scale plot dimensions, censusing of all stems ≥1 cm in diameter, inclusion of tropical, temperate and boreal forests, and investigation of additional biotic (e.g., arthropods) and abiotic (e.g., soils) drivers, which together provide a holistic view of forest functioning. The 71 FDPs in 27 countries include approximately 7.33 million living trees and about 12,000 species, representing 20% of the world's known tree diversity. With >1300 published papers, ForestGEO researchers have made significant contributions in two fundamental areas: species coexistence and diversity, and ecosystem functioning. Specifically, defining the major biotic and abiotic controls on the distribution and coexistence of species and functional types and on variation in species' demography has led to improved understanding of how the multiple dimensions of forest diversity are structured across space and time and how this diversity relates to the processes controlling the role of forests in the Earth system. Nevertheless, knowledge gaps remain that impede our ability to predict how forest diversity and function will respond to climate change and other stressors. Meeting these global research challenges requires major advances in standardizing taxonomy of tropical species, resolving the main drivers of forest dynamics, and integrating plot-based ground and remote sensing observations to scale up estimates of forest diversity and function, coupled with improved predictive models. However, they cannot be met without greater financial commitment to sustain the long-term research of ForestGEO and other forest plot networks, greatly expanded scientific capacity across the world's forested nations, and increased collaboration and integration among research networks and disciplines addressing forest science.
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| 4. |
- Fan, Jin, et al.
(författare)
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Design of Novel Flat Bend Crossed Dipole for Wideband Phased Array Feed Applications
- 2019
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Ingår i: 2019 International Symposium on Antennas and Propagation, ISAP 2019 - Proceedings.
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Konferensbidrag (refereegranskat)abstract
- This paper presents a novel Phased Array Feed (PAF) element based on flat bend crossed dipole fed by 50-Ohm coaxial line. The PAF element is dual-polarized and made from all-metal to minimize Ohmic losses and simplify cryogenic integration. It is optimized for 4- 8 GHz band aiming to possible later integration in the SKA pathfinder PHAROS2. The proposed design can also be a good element candidate of PAF for the Five hundred meter Aperture Spherical Telescope (FAST) and Qi Tai Telescope (QTT) as well as other large radio telescopes.
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| 5. |
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| 6. |
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| 7. |
- Zheng, Hongwei, et al.
(författare)
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Photoconjugation of temperature- and pH-responsive polymer with silica nanoparticles for separation and enrichment of bacteria
- 2021
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Ingår i: Colloids and Surfaces B: Biointerfaces. - : Elsevier BV. - 0927-7765. ; 197
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Tidskriftsartikel (refereegranskat)abstract
- A new photoconjugation approach was developed to prepare nanoparticle-supported boronic acid polymer for effective separation and enrichment of bacteria. The photo-activated polymer immobilization was demonstrated by coupling an azide-modified copolymer of N-isopropylacrylamide and glycidyl methacrylate to a perfluorophenyl azide-modified silica surface. The thermoresponsive polymer was synthesized using reversible addition fragmentation chain transfer polymerization followed by conversion of the pendant epoxides into azide groups. The perfluorophenyl azide-modified silica nanoparticles were synthesized by an amidation reaction between amino-functionalized silica and pentafluorobenzoyl chloride, and a subsequent treatment with sodium azide. Bacteria-capturing boronic acid was conjugated to the silica-supported polymer chains via Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction. The particle size, morphology and organic content of the composite nanoparticles were characterized systematically. The capability of the nanocomposite to bind Gram-positive and Gram-negative bacteria was investigated. The nanocomposite exhibited high binding capacities for E. coli (13.4 × 107 CFU/mg) and S. epidermidis (7.66 × 107 CFU/mg) in phosphate buffered saline. The new photoconjugation strategy enables fast and straightforward grafting of functional polymers on surface, which opens many new opportunities for designing functional materials for bioseparation and biosensing.
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