| 1. |
- Dou, Jin-Hu, et al.
(författare)
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Atomically precise single-crystal structures of electrically conducting 2D metal-organic frameworks
- 2021
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Ingår i: Nature Materials. - : Springer Science and Business Media LLC. - 1476-1122 .- 1476-4660. ; 20, s. 222-228
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Tidskriftsartikel (refereegranskat)abstract
- Electrically conducting 2D metal-organic frameworks (MOFs) have attracted considerable interest, as their hexagonal 2D lattices mimic graphite and other 2D van der Waals stacked materials. However, understanding their intrinsic properties remains a challenge because their crystals are too small or of too poor quality for crystal structure determination. Here, we report atomically precise structures of a family of 2D pi-conjugated MOFs derived from large single crystals of sizes up to 200 mu m, allowing atomic-resolution analysis by a battery of high-resolution diffraction techniques. A designed ligand core rebalances the in-plane and out-of-plane interactions that define anisotropic crystal growth. We report two crystal structure types exhibiting analogous 2D honeycomb-like sheets but distinct packing modes and pore contents. Single-crystal electrical transport measurements distinctively demonstrate anisotropic transport normal and parallel to the pi-conjugated sheets, revealing a clear correlation between absolute conductivity and the nature of the metal cation and 2D sheet packing motif. Two-dimensional MOFs can possess porosity and electrical conductivity but are difficult to grow as single crystals. Here, by balancing in-plane and out-of-plane interactions, single crystals of sizes up to 200 mu m are grown, allowing in-plane transport measurements and atomic-resolution analysis.
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| 2. |
- Li, Hui, et al.
(författare)
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Enabling the transition to ductile MAX phases and the exfoliation to MXenes via tuning the A element
- 2023
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Ingår i: Journal of The American Ceramic Society. - : Wiley-Blackwell. - 0002-7820 .- 1551-2916. ; 106:6, s. 3765-3776
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Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional MXenes, exfoliated from their parental precursors-MAX phases, exhibit several outstanding properties and have achieved several accomplishments in a vast range of fields. Developing novel and high-performance MXenes has become a vital task in materials science, so estimating the possibilities for exfoliation is a topic positioned at the research frontier. Here, the likelihood of exfoliating 36 M(2)AC MAX phases was explored by using density functional theory. For MAX phases, the composition-dependent mechanical performances were investigated, highlighting evident trends, and, more essentially, improving MAX phases toughness, which can be achieved via modulating the A site. Two novel criteria were then introduced to assess the probability of exfoliating MXenes from MAX phases, having less complexity and lower computational cost than the prior studies. The excellent agreement provided by the new criteria with the reported results demonstrates that they are feasible, reliable as well as easily accessible. Furthermore, some key features that were previously suggested to be related to exfoliation are instead determined to be weakly correlated with it. We thus performed a detailed numerical analysis to locate representative and correlated features that are fundamental for the exfoliation. Our findings provide deep insight into the synthesis process and accelerate the discovery of new MXenes.
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| 3. |
- Zhang, Jing, et al.
(författare)
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Unraveling the role of the BCC-B2 transition and V occupancies in the contradictory magnetism-ductility relationship of FeCoV alloys
- 2024
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Ingår i: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388 .- 1873-4669. ; 997
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Tidskriftsartikel (refereegranskat)abstract
- The contradictory relationship between magnetism and ductility restricts further applications of FeCoV alloys in high-performance electrical machines. The role of the BCC-B2 transition, accompanied by vanadium (V) site occupancies, in magnetic moments and ductility has been explored using first-principles calculations. The variations in magnetism and ductility of FeCoV alloys are attributed to the coupling of the BCC-B2 transition and V occupancies. When V replaces Fe atoms in the equiatomic B2-FeCo alloy, the superior magnetism observed in B2-Fe50-cCo50Vc alloys is a consequence of the enhanced local magnetic moment of Fe and the ferrimagnetic-ferromagnetic transition in the magnetic state. Moreover, due to the preferential V occupancy in the B2 phase, the B2-Fe46Co50V4 alloy exhibits comparable ductility to the BCC-Fe50Co46V4 alloy. The results indicate that the increased brittleness in the B2 phase arises from the raised Peierls stress and the enhanced covalent component in interatomic bonding, which is caused by the strong hybridization between Fe and Co atoms. Pearson correlation analysis illustrates that valence electron concentration (VEC) and V content are significant factors in the contradictory relationship between magnetization and ductility. The theoretical results demonstrate that tuning the V content and atomic occupancies is helpful to achieve a trade-off between magnetization and ductility in B2-FeCoV alloys.
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| 4. |
- Chen, Jie, et al.
(författare)
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Bidirectional Mendelian Randomisation Analysis Provides Evidence for the Causal Involvement of Dysregulation of CXCL9, CCL11 and CASP8 in the Pathogenesis of Ulcerative Colitis
- 2023
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Ingår i: Journal of Crohn's & Colitis. - : Oxford University Press. - 1873-9946 .- 1876-4479. ; 17:5, s. 777-785
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims Systemic inflammation is well recognised to be associated with ulcerative colitis [UC], but whether these effects are causal or consequential remains unclear. We aimed to define potential causal relationship of cytokine dysregulation with different tiers of evidence. Methods We first synthesised serum proteomic profiling data from two multicentred observational studies, in which a panel of systemic inflammatory proteins was analysed to examine their associations with UC risk. To further dissect observed associations, we then performed a bidirectional two-sample Mendelian randomisation [TSMR] analysis from both forward and reverse directions using five genome-wide association study [GWAS] summary level data for serum proteomic profiles and the largest GWAS of 28 738 European-ancestry individuals for UC risk. Results Pooled analysis of serum proteomic data identified 14 proteins to be associated with the risk of UC. Forward MR analysis using only cis-acting protein quantitative trait loci [cis-pQTLs] or trans-pQTLs further validated causal associations of two chemokines and the increased risk of UC: C-X-C motif chemokine ligand 9 [CXCL9] [OR 1.45, 95% CI 1.08, 1.95, p = 0.012] and C-C motif chemokine ligand 11 [CCL11] [OR 1.14, 95% CI 1.09, 1.18, p = 3.89 x 10(-10)]. Using both cis- and trans-acting pQTLs, an association of caspase-8 [CASP8] [OR 1.04, 95% CI 1.03, 1.05, p = 7.63 x 10(-19)] was additionally identified. Reverse MR did not find any influence of genetic predisposition to UC on any of these three inflammation proteins. Conclusion Pre-existing elevated levels of CXCL9, CCL11 and CASP8 may play a role in the pathogenesis of UC.
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| 5. |
- Kanoni, Stavroula, et al.
(författare)
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Implicating genes, pleiotropy, and sexual dimorphism at blood lipid loci through multi-ancestry meta-analysis.
- 2022
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Ingår i: Genome biology. - : Springer Science and Business Media LLC. - 1474-760X .- 1465-6906 .- 1474-7596. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- Genetic variants within nearly 1000 loci are known to contribute to modulation of blood lipid levels. However, the biological pathways underlying these associations are frequently unknown, limiting understanding of these findings and hindering downstream translational efforts such as drug target discovery.To expand our understanding of the underlying biological pathways and mechanisms controlling blood lipid levels, we leverage a large multi-ancestry meta-analysis (N=1,654,960) of blood lipids to prioritize putative causal genes for 2286 lipid associations using six gene prediction approaches. Using phenome-wide association (PheWAS) scans, we identify relationships of genetically predicted lipid levels to other diseases and conditions. We confirm known pleiotropic associations with cardiovascular phenotypes and determine novel associations, notably with cholelithiasis risk. We perform sex-stratified GWAS meta-analysis of lipid levels and show that 3-5% of autosomal lipid-associated loci demonstrate sex-biased effects. Finally, we report 21 novel lipid loci identified on the X chromosome. Many of the sex-biased autosomal and X chromosome lipid loci show pleiotropic associations with sex hormones, emphasizing the role of hormone regulation in lipid metabolism.Taken together, our findings provide insights into the biological mechanisms through which associated variants lead to altered lipid levels and potentially cardiovascular disease risk.
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| 6. |
- Lee, Chunsik, et al.
(författare)
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VEGF-B prevents excessive angiogenesis by inhibiting FGF2/FGFR1 pathway
- 2023
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Ingår i: SIGNAL TRANSDUCTION AND TARGETED THERAPY. - : SPRINGERNATURE. - 2095-9907 .- 2059-3635. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Although VEGF-B was discovered as a VEGF-A homolog a long time ago, the angiogenic effect of VEGF-B remains poorly understood with limited and diverse findings from different groups. Notwithstanding, drugs that inhibit VEGF-B together with other VEGF family members are being used to treat patients with various neovascular diseases. It is therefore critical to have a better understanding of the angiogenic effect of VEGF-B and the underlying mechanisms. Using comprehensive in vitro and in vivo methods and models, we reveal here for the first time an unexpected and surprising function of VEGF-B as an endogenous inhibitor of angiogenesis by inhibiting the FGF2/FGFR1 pathway when the latter is abundantly expressed. Mechanistically, we unveil that VEGF-B binds to FGFR1, induces FGFR1/VEGFR1 complex formation, and suppresses FGF2-induced Erk activation, and inhibits FGF2-driven angiogenesis and tumor growth. Our work uncovers a previously unrecognized novel function of VEGF-B in tethering the FGF2/FGFR1 pathway. Given the anti-angiogenic nature of VEGF-B under conditions of high FGF2/FGFR1 levels, caution is warranted when modulating VEGF-B activity to treat neovascular diseases.
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| 7. |
- Liang, Lin, et al.
(författare)
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Non-Interpenetrated Single-Crystal Covalent Organic Frameworks
- 2020
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 59:41, s. 17991-17995
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Tidskriftsartikel (refereegranskat)abstract
- Growth of covalent organic frameworks (COFs) as single crystals is extremely challenging. Inaccessibility of open-structured single-crystal COFs prevents the exploration of structure-oriented applications. Herein we report for the first time a non-interpenetrated single-crystal COF, LZU-306, which possesses the open structure constructed exclusively via covalent assembly. With a high void volume of 80 %, LZU-306 was applied to investigate the intrinsic dynamics of reticulated tetraphenylethylene (TPE) as the individual aggregation-induced-emission moiety. Solid-state(2)H NMR investigation has determined that the rotation of benzene rings in TPE, being the freest among the reported cases, is as fast as 1.0x10(4) Hz at 203 K to 1.5x10(7) Hz at 293 K. This research not only explores a new paradigm for single-crystal growth of open frameworks, but also provides a unique matrix-isolation platform to reticulate functional moieties into a well-defined and isolated state.
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| 8. |
- Lin, Shangrong, et al.
(författare)
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Underestimated Interannual Variability of Terrestrial Vegetation Production by Terrestrial Ecosystem Models
- 2023
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Ingår i: Global Biogeochemical Cycles. - 0886-6236. ; 37:4
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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.
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| 9. |
- Lu, Yingchang, et al.
(författare)
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Identification of Novel Loci and New Risk Variant in Known Loci for Colorectal Cancer Risk in East Asians
- 2020
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - : American Association for Cancer Research. - 1055-9965 .- 1538-7755. ; 29:2, s. 477-486
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Tidskriftsartikel (refereegranskat)abstract
- Background: Risk variants identified so far for colorectal cancer explain only a small proportion of milial risk of this cancer, particularly in Asians.Methods: We performed a genome-wide association study (GWAS) of colorectal cancer in East Asians, cluding 23,572 colorectal cancer cases and 48,700 controls. To identify novel risk loci, we selected 60 omising risk variants for replication using data from 58,131 colorectal cancer cases and 67,347 controls European descent. To identify additional risk variants in known colorectal cancer loci, we performed nditional analyses in East Asians.Results: An indel variant, rs67052019 at 1p13.3, was found to be associated with colorectal cancer risk P = 3.9 x 10(-8) in Asians (OR per allele deletion = 1.13, 95% confidence interval = 1.08-1.18). This sociation was replicated in European descendants using a variant (rs2938616) in complete linkage sequilibrium with rs67052019 (P = 7.7 x 10(-3)). Of the remaining 59 variants, 12 showed an association P < 0.05 in the European-ancestry study, including rs11108175 and rs9634162 at P < 5 x 10(-8) and o variants with an association near the genome-wide significance level (rs60911071, P = 5.8 x 10(-8); 62558833, P = 7.5 x 10(-8)) in the combined analyses of Asian- and European-ancestry data. In addition, ing data from East Asians, we identified 13 new risk variants at 11 loci reported from previous GWAS.Conclusions: In this large GWAS, we identified three novel risk loci and two highly suggestive loci for lorectal cancer risk and provided evidence for potential roles of multiple genes and pathways in the iology of colorectal cancer. In addition, we showed that additional risk variants exist in many colorectal ncer risk loci identified previously.Impact: Our study provides novel data to improve the understanding of the genetic basis for colorectal ncer risk.
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| 10. |
- Sun, Yuhao, et al.
(författare)
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The Contribution of Genetic Risk and Lifestyle Factors in the Development of Adult-Onset Inflammatory Bowel Disease : A Prospective Cohort Study
- 2023
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Ingår i: American Journal of Gastroenterology. - : Lippincott Williams & Wilkins. - 0002-9270 .- 1572-0241. ; 118:3, s. 511-522
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: The joint associations across genetic risk, modifiable lifestyle factors, and inflammatory bowel disease (IBD) remains unclear.METHODS: Genetic susceptibility to Crohn's disease (CD) and ulcerative colitis (UC) was estimated by polygenic risk scores and further categorized into high, intermediate, and low genetic risk categories. Weighted healthy lifestyle scores were constructed based on 5 common lifestyle factors and categorized into favorable (4 or 5 healthy lifestyle factors), intermediate (3 healthy lifestyle factors), and unfavorable (0-2 healthy lifestyle factors) groups. Cox proportional hazards regression model was used to estimate the hazard ratios (HR) and 95% confidence interval (CI) for their associations.RESULTS: During the 12-year follow-up, 707 cases with CD and 1576 cases with UC were diagnosed in the UK Biobank cohort. Genetic risk and unhealthy lifestyle categories were monotonically associated with CD and UC risk with no multiplicative interaction between them. The HR of CD and UC were 2.24 (95% CI 1.75-2.86) and 2.15 (95% CI 1.82-2.53) for those with a high genetic risk, respectively. The HR of CD and UC for individuals with an unfavorable lifestyle were 1.94 (95% CI 1.61-2.33) and 1.98 (95% CI 1.73-2.27), respectively. The HR of individuals with a high genetic risk but a favorable lifestyle (2.33, 95% CI 1.58-3.44 for CD, and 2.05, 95% CI 1.58-2.66 for UC) were reduced nearly by half, compared with those with a high genetic risk but an unfavorable lifestyle (4.40, 95% CI 2.91-6.66 for CD and 4.44, 95% CI 3.34-5.91 for UC).DISCUSSION: Genetic and lifestyle factors were independently associated with susceptibility to incident CD and UC. Adherence to a favorable lifestyle was associated with a nearly 50% lower risk of CD and UC among participants at a high genetic risk.
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