ORCID Profile
0000-0002-6078-3006
Current Organisation
Linköpings universitet
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Publisher: Springer Science and Business Media LLC
Date: 26-05-2023
DOI: 10.1007/S43939-023-00046-6
Abstract: The conducting polymer poly(3,4-ethylenedioxythiophene) (known as PEDOT) is routinely fabricated into doped thin films for investigation of its inherent properties as well as for a range of applications. Fabrication of PEDOT is often achieved via oxidative polymerisation, where the conducting polymer is polymerised and doped (oxidised) to yield a conductive polymer thin film. The oxidiser and the polymerisation temperature are two parameters that may influence the properties and performance of the resultant PEDOT thin film. In this study, the role of temperature for the chemical polymerisation of PEDOT using the oxidiser iron tosylate is investigated from a computational and experimental viewpoint. While computations of the doping energetics suggest increasing doping with increasing temperature, x-ray photoelectron spectroscopy of fabricated PEDOT thin films indicate doping is much more complicated. With the aid of computations of the spatial distribution functions for tosylate in PEDOT, experiments indicate that two different populations of tosylate anions exist in the PEDOT matrix. Their relative populations change as a function of the polymerisation temperature. Therefore, polymerisation temperature plays a critical role in tailoring the properties of PEDOT in pursuit of being fit-for-purpose for the desired application.
Publisher: Springer Science and Business Media LLC
Date: 23-10-2019
DOI: 10.1038/S41598-019-51592-0
Abstract: Resistin is a key cytokine associated with metabolic and inflammatory diseases. Especially in East Asian populations, the expression levels are strongly influenced by genetic polymorphisms. Mechanisms and functional implications of this genetic control are still unknown. By employing reporter assays, EMSA, inhibition studies, bisulphite sequencing, ChIP-Seq and gene-editing we show that the p50 50 homodimer known to act as repressor for a number of pro-inflammatory genes plays a central role in the genetic regulation of resistin in monocytes along with promoter methylation. In the common RETN haplotype p50 50 constitutively d ens the expression by binding to the promoter. In an Asian haplotype variant however this interaction is disrupted by the A allele of rs3219175. The SNP is in very close linkage to rs34861192, a CpG SNP, located 280 bp upstream which provides an allele-specific C-methylation site. rs34861192 is located in a 100 bp region found to be methylated in the common but not in the Asian haplotype, resulting in the latter having a higher basal expression, which also associates with elevated histone acetylation (H3K27ac). Genotype associations within cohort data of 200 East Asian in iduals revealed significant associations between this haplotype and the plasma levels of factors such as TGF-b, S100B, sRAGE and IL-8 as well as with myeloid DC counts. Thus, the common RETN haplotype is tightly regulated by the epigenetic mechanism linked to p50 50-binding. This control is lost in the Asian haplotype, which may have evolved to balance the antagonistic RETN effects on pathogen protection vs. metabolic and inflammatory disease induction.
Publisher: Springer Science and Business Media LLC
Date: 02-09-2022
Publisher: Springer Science and Business Media LLC
Date: 21-05-2014
DOI: 10.1038/NMAT3981
Publisher: American Chemical Society (ACS)
Date: 11-12-2019
Publisher: Springer Science and Business Media LLC
Date: 31-01-2022
DOI: 10.1038/S41564-021-01049-W
Abstract: Host cell chromatin changes are thought to play an important role in the pathogenesis of infectious diseases. Here we describe a histone acetylome-wide association study (HAWAS) of an infectious disease, on the basis of genome-wide H3K27 acetylation profiling of peripheral blood granulocytes and monocytes from persons with active Mycobacterium tuberculosis ( Mtb ) infection and healthy controls. We detected ,000 differentially acetylated loci in either cell type in a Singapore Chinese discovery cohort ( n = 46), which were validated in a subsequent multi-ethnic Singapore cohort ( n = 29), as well as a longitudinal cohort from South Africa ( n = 26), thus demonstrating that HAWAS can be independently corroborated. Acetylation changes were correlated with differential gene expression. Differential acetylation was enriched near potassium channel genes, including KCNJ15 , which modulates apoptosis and promotes Mtb clearance in vitro. We performed histone acetylation quantitative trait locus (haQTL) analysis on the dataset and identified 69 candidate causal variants for immune phenotypes among granulocyte haQTLs and 83 among monocyte haQTLs. Our study provides proof-of-principle for HAWAS to infer mechanisms of host response to pathogens.
Publisher: Wiley
Date: 16-10-2017
DOI: 10.1002/POLB.24530
Publisher: Springer Science and Business Media LLC
Date: 08-12-2013
DOI: 10.1038/NMAT3824
Abstract: Polymers are lightweight, flexible, solution-processable materials that are promising for low-cost printed electronics as well as for mass-produced and large-area applications. Previous studies demonstrated that they can possess insulating, semiconducting or metallic properties here we report that polymers can also be semi-metallic. Semi-metals, exemplified by bismuth, graphite and telluride alloys, have no energy bandgap and a very low density of states at the Fermi level. Furthermore, they typically have a higher Seebeck coefficient and lower thermal conductivities compared with metals, thus being suitable for thermoelectric applications. We measure the thermoelectric properties of various poly(3,4-ethylenedioxythiophene) s les, and observe a marked increase in the Seebeck coefficient when the electrical conductivity is enhanced through molecular organization. This initiates the transition from a Fermi glass to a semi-metal. The high Seebeck value, the metallic conductivity at room temperature and the absence of unpaired electron spins makes polymer semi-metals attractive for thermoelectrics and spintronics.
No related grants have been discovered for Igor Zozoulenko.