| 1. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Fu, Yifeng, 1984, et al.
(författare)
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Templated Growth of Covalently Bonded Three-Dimensional Carbon Nanotube Networks Originated from Graphene
- 2012
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 24:12, s. 1576-1581
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Tidskriftsartikel (refereegranskat)abstract
- A template-assisted method that enables the growth of covalently bonded three-dimensional carbon nanotubes (CNTs) originating from graphene at a large scale is demonstrated. Atomic force microscopy-based mechanical tests show that the covalently bonded CNT structure can effectively distribute external loading throughout the network to improve the mechanical strength of the material.
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| 3. |
- Huang, Liping, et al.
(författare)
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Interim effects of salt substitution on urinary electrolytes and blood pressure in the China Salt Substitute and Stroke Study (SSaSS).
- 2020
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Ingår i: American Heart Journal. - : Elsevier BV. - 0002-8703 .- 1097-6744. ; 221, s. 136-145
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Tidskriftsartikel (refereegranskat)abstract
- The Salt Substitute and Stroke Study is an ongoing 5-year large-scale cluster randomized trial investigating the effects of potassium-enriched salt substitute compared to usual salt on the risk of stroke. The study involves 600 villages and 20,996 individuals in rural China. Intermediate risk markers were measured in a random subsample of villages every 12 months over 3 years to track progress against key assumptions underlying study design. Measures of 24-hour urinary sodium, 24-hour urinary potassium, blood pressure and participants' use of salt substitute were recorded, with differences between intervention and control groups estimated using generalized linear mixed models. The primary outcome of annual event rate in the two groups combined was determined by dividing confirmed fatal and non-fatal strokes by total follow-up time in the first 2 years. The mean differences (95% CI) were -0.32 g (-0.68 to 0.05) for 24-hour urinary sodium, +0.77 g (+0.60 to +0.93) for 24-hour urinary potassium, -2.65 mmHg (-4.32 to -0.97) for systolic blood pressure and +0.30 mmHg (-0.72 to +1.32) for diastolic blood pressure. Use of salt substitute was reported by 97.5% in the intervention group versus 4.2% in the control group (P<.0001). The overall estimated annual event rate for fatal and non-fatal stroke was 3.2%. The systolic blood pressure difference and the annual stroke rate were both in line with the statistical assumptions underlying study design. The trial should be well placed to address the primary hypothesis at completion of follow-up.
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| 4. |
- Canelas, A.B., et al.
(författare)
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Integrated multilaboratory systems biology reveals differences in protein metabolism between two reference yeast strains
- 2010
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 1:9
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Tidskriftsartikel (refereegranskat)abstract
- The field of systems biology is often held back by difficulties in obtaining comprehensive, high-quality, quantitative data sets. In this paper, we undertook an interlaboratory effort to generate such a data set for a very large number of cellular components in the yeast Saccharomyces cerevisiae, a widely used model organism that is also used in the production of fuels, chemicals, food ingredients and pharmaceuticals. With the current focus on biofuels and sustainability, there is much interest in harnessing this species as a general cell factory. In this study, we characterized two yeast strains, under two standard growth conditions. We ensured the high quality of the experimental data by evaluating a wide range of sampling and analytical techniques. Here we show significant differences in the maximum specific growth rate and biomass yield between the two strains. On the basis of the integrated analysis of the high-throughput data, we hypothesize that differences in phenotype are due to differences in protein metabolism.
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| 5. |
- Cao, Yuan, et al.
(författare)
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Hybrid Trusted/Untrusted Relay Based Quantum Key Distribution over Optical Backbone Networks
- 2021
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Ingår i: IEEE Journal on Selected Areas in Communications. - 0733-8716 .- 1558-0008. ; 39:9, s. 2701-2718
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Tidskriftsartikel (refereegranskat)abstract
- Quantum key distribution (QKD) has demonstrated a great potential to provide future-proofed security, especially for 5G and beyond communications. As the critical infrastructure for 5G and beyond communications, optical networks can offer a cost-effective solution to QKD deployment utilizing the existing fiber resources. In particular, measurement-device-independent QKD shows its ability to extend the secure distance with the aid of an untrusted relay. Compared to the trusted relay, the untrusted relay has obviously better security, since it does not rely on any assumption on measurement and even allows to be accessed by an eavesdropper. However, it cannot extend QKD to an arbitrary distance like the trusted relay, such that it is expected to be combined with the trusted relay for large-scale QKD deployment. In this work, we study the hybrid trusted/untrusted relay based QKD deployment over optical backbone networks and focus on cost optimization during the deployment phase. A new network architecture of hybrid trusted/untrusted relay based QKD over optical backbone networks is described, where the node structures of the trusted relay and untrusted relay are elaborated. The corresponding network, cost, and security models are formulated. To optimize the deployment cost, an integer linear programming model and a heuristic algorithm are designed. Numerical simulations verify that the cost-optimized design can significantly outperform the benchmark algorithm in terms of deployment cost and security level. Up to 25% cost saving can be achieved by deploying QKD with the hybrid trusted/untrusted relay scheme while keeping much higher security level relative to the conventional point-to-point QKD protocols that are only with the trusted relays.
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| 6. |
- Chen, Lei, 1981-, et al.
(författare)
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Mathematical Modeling for Optimal Deployment of In-Building Distributed Antenna Systems
- 2012
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Ingår i: Communications in China (ICCC), 2012. - : IEEE. - 9781467328142 ; , s. 786-791
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Konferensbidrag (refereegranskat)abstract
- In-building Distributed Antenna System (IB-DAS) has been proved to be one of the most efficient methods to provide sufficient coverage and capacity for indoor users. The target of a successful IB-DAS deployment is to guarantee the coverage as well as the capacity of the in-building areas with minimum deployment cost. We consider the optimaldeployment of the IB-DAS based on passive DAS in this paper. Mixed Integer Programming model has been developed forthe topology design of IB-DAS through the optimal installation of power splitters in order to connect all the antennas with minimum cable cost, meanwhile, the transmit power at each antenna are kept within the satisfied level for the service guarantee. The model can deliver optimal solutions to systems with a practical size where passive DAS is commonly deployed. To improve the time efficiency, preprocessing has been done to integrate the building layout data into themodeling. Application of the model over realistic IB-DAS deployment has been conducted, which demonstrates the effectiveness of the model.
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| 7. |
- Chumnanpuen, Pramote, 1983, et al.
(författare)
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Integrated analysis of transcriptome and lipid profiling reveals the co-influences of inositol-choline and Snf1 in controlling lipid biosynthesis in yeast
- 2012
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Ingår i: Molecular Genetics and Genomics. - : Springer Science and Business Media LLC. - 1617-4615 .- 1617-4623. ; 287:7, s. 541-554
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Tidskriftsartikel (refereegranskat)abstract
- In the yeast Saccharomyces cerevisiae many genes involved in lipid biosynthesis are transcriptionally controlled by inositol-choline and the protein kinase Snf1. Here we undertook a global study on how inositol-choline and Snf1 interact in controlling lipid metabolism in yeast. Using both a reference strain (CEN.PK113-7D) and a snf1 Delta strain cultured at different nutrient limitations (carbon and nitrogen), at a fixed specific growth rate of 0.1 h(-1), and at different inositol choline concentrations, we quantified the expression of genes involved in lipid biosynthesis and the fluxes towards the different lipid components. Through integrated analysis of the transcriptome, the lipid profiling and the fluxome, it was possible to obtain a high quality, large-scale dataset that could be used to identify correlations and associations between the different components. At the transcription level, Snf1 and inositol-choline interact either directly through the main phospholipid-involving transcription factors (i.e. Ino2, Ino4, and Opi1) or through other transcription factors e.g. Gis1, Mga2, and Hac1. However, there seems to be flux regulation at the enzyme levels of several lipid involving enzymes. The analysis showed the strength of using both transcriptome and lipid profiling analysis for mapping the co-influence of inositol-choline and Snf1 on phospholipid metabolism.
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| 8. |
- Fan, Qunping, et al.
(författare)
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Unidirectional Sidechain Engineering to Construct Dual-Asymmetric Acceptors for 19.23 % Efficiency Organic Solar Cells with Low Energy Loss and Efficient Charge Transfer
- 2023
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Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 62:36
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Tidskriftsartikel (refereegranskat)abstract
- Achieving both high open-circuit voltage (V-oc) and short-circuit current density (J(sc)) to boost power-conversion efficiency (PCE) is a major challenge for organic solar cells (OSCs), wherein high energy loss (E-loss) and inefficient charge transfer usually take place. Here, three new Y-series acceptors of mono-asymmetric asy-YC11 and dual-asymmetric bi-asy-YC9 and bi-asy-YC12 are developed. They share the same asymmetric D(1)AD(2) (D-1=thieno[3,2-b]thiophene and D-2=selenopheno[3,2-b]thiophene) fused-core but have different unidirectional sidechain on D-1 side, allowing fine-tuned molecular properties, such as intermolecular interaction, packing pattern, and crystallinity. Among the binary blends, the PM6 : bi-asy-YC12 one has better morphology with appropriate phase separation and higher order packing than the PM6 : asy-YC9 and PM6 : bi-asy-YC11 ones. Therefore, the PM6 : bi-asy-YC12-based OSCs offer a higher PCE of 17.16 % with both high V-oc and J(sc), due to the reduced E-loss and efficient charge transfer properties. Inspired by the high V-oc and strong NIR-absorption, bi-asy-YC12 is introduced into efficient binary PM6 : L8-BO to construct ternary OSCs. Thanks to the broadened absorption, optimized morphology, and furtherly minimized E-loss, the PM6 : L8-BO : bi-asy-YC12-based OSCs achieve a champion PCE of 19.23 %, which is one of the highest efficiencies among these annealing-free devices. Our developed unidirectional sidechain engineering for constructing bi-asymmetric Y-series acceptors provides an approach to boost PCE of OSCs.
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| 9. |
- Liu, Linpeng, et al.
(författare)
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Ni and Fe catalyzed cascade radical reactions of oxime esters with diselenides
- 2022
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Ingår i: Organic Chemistry Frontiers. - : Royal Society of Chemistry (RSC). - 2052-4129. ; 9:13, s. 3480-3485
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Tidskriftsartikel (refereegranskat)abstract
- A radical cyclization and ring-opening of oxime esters with diselenides was developed. Both Ni(0) and Fe(II) catalysts could be employed for the selenylation of olefin-containing and cyclic oxime ester derivatives. With this method, a variety of functionalized pyrrolines and alkyl nitriles were synthesized in good yields. Moreover, a mechanism involving iminyl radical and carbon-centered radical intermediates was proposed.
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| 10. |
- Lu, Yiping, et al.
(författare)
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Directly cast bulk eutectic and near-eutectic high entropy alloys with balanced strength and ductility in a wide temperature range
- 2017
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Ingår i: Acta Materialia. - : Elsevier BV. - 1359-6454. ; 124, s. 143-150
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Tidskriftsartikel (refereegranskat)abstract
- High entropy alloys (HEAs) usually possess weak liquidity and castability, and considerable compositional inhomogeneity, mainly because they contain multiple elements with high concentrations. As a result, large-scale production of HEAs by casting is limited. To address the issue, the concept of eutectic high entropy alloys (EHEAs) was proposed, which has led to some promise in achieving good quality industrial scale HEAs ingots, and more importantly also good mechanical properties. In the practical large-scale casting, the actual composition of designed EHEAs could potentially deviate from the eutectic composition. The influence of such deviation on mechanical properties of EHEAs is important for industrial production, which constitutes the topic of the current work. Here we prepared industrial-scale HEAs ingots near the eutectic composition: hypoeutectic alloy, eutectic alloy and hypereutectic alloy. Our results showed that the deviation from eutectic composition does not significantly affect the mechanical properties, castability and the good mechanical properties of EHEAs can be achieved in a wide compositional range, and at both room and cryogenic temperatures. Our results suggested that EHEAs with simultaneous high strength and high ductility, and good liquidity and castability can be readily adapted to large-scale industrial production. The deformation behavior and microstructure evolution of the eutectic and near-eutectic HEAs were thoroughly studied using a combination of techniques, including strain measurement by digital image correlation, in-situ synchrotron X-ray diffraction, and transmission electron microscopy. The wavy strain distribution and the therefore resulted delay of necking in EHEAs were reported for the first time.
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| 11. |
- Zhang, Feng, 1981-, et al.
(författare)
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Nonradiative decay of the lowest excited singlet state of 2-aminopyridine is considerably faster than the radiative decay
- 2009
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Ingår i: Journal of Chemical Physics. - America : American -institute of Physics. - 0021-9606 .- 1089-7690. ; 130:14, s. 144315-
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Tidskriftsartikel (refereegranskat)abstract
- Ab initio calculations reveal that radiative lifetime of the lowest excited singlet state of 2-aminopyridine (2AP) molecule should be around 20 ns, consistent with the molecules of the same type, but is about one order of magnitude larger than the claimed experimental fluorescent lifetime in recent years. A S1/S0 conical intersection close to the S1 state has been located which could be the possible nonradiative channel that is responsible for the fast decay observed in the experiment.
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| 12. |
- Zhang, H., et al.
(författare)
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Ageing hardening and corrosion resistance of Fe 60 Cr 18 Cu 3 (MnCoNiMoAlTi) 19 medium-entropy alloy
- 2023
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Ingår i: Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals. - 1004-0609. ; 33:8, s. 2622-2634
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Tidskriftsartikel (refereegranskat)abstract
- Fe60Cr18Cu3(CoMnMoNiAlTi)19 medium-entropy stainless alloy (MEA) was prepared by vacuum arc furnace melting. The ageing hardening mechanism and corrosion resistance of alloy were studied. The results show that the MEA has simple BCC solid solution phase after solidification, due to the influence of medium-entropy effect. HRTEM results show that the high level of lattice distortion in the supersaturated BCC solid solution matrix leads to a high amount of nanometer-sized ordered B2 coherent precipitates after ageing treatment, and the maximum hardness of MESS after ageing reaches 621HV0.5. The resistance to corrosion in hot sulfuric acid and to pitting in the NaCl solution are both greatly improved compared with the conventional 17-4PH steel, as evidenced by more stable anodic passivation zone and significantly reduced corrosion dissolution rate in the MEA. XPS analyses results show that the multi-component passive film, which composes of high contents of anti-corrosion elements including Crhy3 +, Crox3 +, Cu+ox, Ti4ox+, Al3ox+ and Mo6ox+, is the main reason for the excellent pitting resistance and the reduced growth of pitting pit in the NaCl solution.
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| 13. |
- Zhang, Jie, 1981
(författare)
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Global Regulation of Snf1 in Saccharomyces cerevisiae: A case study of experimental systems biology
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cells commonly face environmental changes and have evolved various regulatory mechanisms to adjust their metabolism accordingly. One such key regulator in S. cerevisiae is the Snf1 kinase, which belongs to the conserved AMP-activated protein kinase (AMPK) family in all eukaryotes. The main function of Snf1 is to sense the energetic status in the cell and switch the cell metabolism from anabolism to catabolism through a complex regulatory network. In this study, we applied an experimental systems biology approach to study the regulation of Snf1 in S. cerevisiae at the global level. First, we show that the three β-subunits of Snf1 (Sip1, Sip2 and Gal83) are not redundant and found that Sip2, but not Sip1, can take over in the utilization of ethanol and glycerol when Gal83 is deleted, although both Sip1 and Sip2 isoforms can utilize acetate as the carbon source. To map the possible protein interactions of Snf1 with TORC1, a key regulator in the nitrogen catabolite repression (NCR), we assessed the global effect of deleting Snf1 and/or Tor1 under nutrient limited conditions. We show that Snf1 may regulate amino acid biosynthesis by inducing the GDH3 encoded glutamate dehydrogenase, and therefore may represent a convergence to the TORC1 pathway. The data also suggest that Snf1 plays a larger role in the regulation of translation under the nutrient-limited conditions tested, compared to TORC1. Finally, we examined the effects of replacing the kinase domain of Snf1 with its analog from AMPK. The chimeric α1-Snf1 kinase restored the functions of Snf1, although to a lesser extent. However, this chimera fails to repress sterol biosynthesis as the native Snf1 does, and we attribute this to different phosphorylation motifs between Snf1 and AMPK. We also propose that Snf1 might repress the sterol biosynthetic genes by phosphorylating Ser272 of the transcription factor Ecm22, and therefore exerts transcriptional regulation on this process. Through these examples, we demonstrate that experimental systems biology is useful for investigating complex regulatory networks and powerful for identifying molecular targets for validation.
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| 14. |
- Zhang, Jie, 1981, et al.
(författare)
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Mapping the interaction of Snf1 with TORC1 in Saccharomyces cerevisiae
- 2011
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Ingår i: Molecular Systems Biology. - : EMBO. - 1744-4292. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Nutrient sensing and coordination of metabolic pathways are crucial functions for all living cells, but details of the coordination under different environmental conditions remain elusive. We therefore undertook a systems biology approach to investigate the interactions between the Snf1 and the target of rapamycin complex 1 (TORC1) in Saccharomyces cerevisiae. We show that Snf1 regulates a much broader range of biological processes compared with TORC1 under both glucose-and ammonium-limited conditions. We also find that Snf1 has a role in upregulating the NADP(+)-dependent glutamate dehydrogenase (encoded by GDH3) under derepressing condition, and therefore may also have a role in ammonium assimilation and amino-acid biosynthesis, which can be considered as a convergence of Snf1 and TORC1 pathways. In addition to the accepted role of Snf1 in regulating fatty acid (FA) metabolism, we show that TORC1 also regulates FA metabolism, likely through modulating the peroxisome and beta-oxidation. Finally, we conclude that direct interactions between Snf1 and TORC1 pathways are unlikely under nutrient-limited conditions and propose that TORC1 is repressed in a manner that is independent of Snf1.
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| 15. |
- Zhang, Jie, 1981, et al.
(författare)
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Systems biology of energy homeostasis in yeast
- 2010
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Ingår i: Current Opinion in Microbiology. - : Elsevier BV. - 1369-5274 .- 1879-0364. ; 13:3, s. 382-388
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Tidskriftsartikel (refereegranskat)abstract
- The yeast Saccharomyces cerevisiae attains energy homeostasis through complex regulatory events that are predominantly controlled by the Snf1 kinase. This master regulator senses the stress and energy starvation and activates the metabolic processes to produce ATP and inhibits biosynthesis. In doing so, Snf1 controls the switch between catabolism and anabolism accordingly, and regulates the cellular growth and development in coordination with other signaling pathways. Since its mammalian ortholog AMPK, a drug target for obesity and type II diabetes, also exerts analogous control of metabolism, there has been extensive interest recently to understand the chemical and biological aspects of Snf1 activation and regulation in yeast to expedite human disease studies as well as fundamental understanding of yeast. This review will focus on how Snf1 regulates lipid metabolism based on the cellular energy status in yeast and drawing parallels with the mammalian system.
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| 16. |
- Zhang, Jie, 1981, et al.
(författare)
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The b-subunits of the Snf1 kinase in Saccharomyces cerevisae, Gal83 and Sip2, but not Sip1 are redundant in glucose derepression and regulation of sterol biosynthesis
- 2010
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Ingår i: Molecular Microbiology. - : Wiley. - 1365-2958 .- 0950-382X. ; 77:2, s. 371-383
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Tidskriftsartikel (refereegranskat)abstract
- The conserved Snf1/AMP-activated protein kinase family is one of the central components in the nutrient sensing and regulation of the carbon metabolism in eukaryotes. It is also involved in several other processes such as stress resistance, invasive growth and ageing. Snf1 kinase is composed of a catalytic β-subunit Snf1, a regulatory γ-subunit Snf4 and one of three possible β-subunits, Sip1, Sip2 or Gal83. We used a systematic approach to study the role of the three β-subunits by analysing all seven possible combinations of β-subunit deletions together with the reference strain. Previous studies showed that the three β-subunits are redundant for growth on alternative carbon sources. Here we report that the mutant strain with only SIP1 expressed (sip2Δ gal83Δ) could utilize acetate, but neither ethanol nor glycerol, as alternative carbon source. We also showed that Gal83 is the most important isoform not only for the growth on non-fermentable carbon sources, but also for regulation of ergosterol biosynthetic genes, under glucose-limited condition. Furthermore, we found that Sip2, but not Sip1, can take over when Gal83 is deleted, but to a lesser extent. However, Sip1 may be sufficient for some other processes such as regulation of the nitrogen metabolism and meiosis. © 2010 Blackwell Publishing Ltd.
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