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1.
ACS Omega ; 9(13): 14874-14886, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38585138

RESUMO

PtSe2 has asserted its key role among the emerging 2D transition metal dichalcogenides, however, its simplified growth process with controlled number of layers, high crystalline quality, and on inexpensive substrates is still challenging. Here, we report the synthesis details of PtSe2 layers on soda lime glass substrates by selenization of predeposited Pt layers using the thermally assisted conversion method at atmospheric pressure. PtSe2 syntheses are confirmed by X-ray photoelectron spectroscopy and Raman analysis. The layers were further investigated with transmission electron microscopy and optical ellipsometry, revealing the thickness and its dependence on the metal precursor sputtering time. Finally, the integration of PtSe2 as transparent conductive layers in polymer-dispersed liquid crystal structures operating as near-infrared light shutters is demonstrated and device performance is discussed. The proposed simple and inexpensive synthesis approach opens up new directions toward PtSe2 potential technological applications, including ITO-free optoelectronics.

2.
Int J Mol Sci ; 24(15)2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37569503

RESUMO

Formation of compact dinucleosomes (CODIs) occurs after collision between adjacent nucleosomes at active regulatory DNA regions. Although CODIs are likely dynamic structures, their structural heterogeneity and dynamics were not systematically addressed. Here, single-particle Förster resonance energy transfer (spFRET) and electron microscopy were employed to study the structure and dynamics of CODIs. spFRET microscopy in solution and in gel revealed considerable uncoiling of nucleosomal DNA from the histone octamer in a fraction of CODIs, suggesting that at least one of the nucleosomes is destabilized in the presence of the adjacent closely positioned nucleosome. Accordingly, electron microscopy analysis suggests that up to 30 bp of nucleosomal DNA are involved in transient uncoiling/recoiling on the octamer. The more open and dynamic nucleosome structure in CODIs cannot be stabilized by histone chaperone Spt6. The data suggest that proper internucleosomal spacing is an important determinant of chromatin stability and support the possibility that CODIs could be intermediates of chromatin disruption.


Assuntos
Transferência Ressonante de Energia de Fluorescência , Nucleossomos , Cromatina , DNA/química , Microscopia Eletrônica
3.
Cells ; 12(15)2023 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-37566080

RESUMO

In this study, we delve into the impact of genotoxic anticancer drug treatment on the chromatin structure of human cells, with a particular focus on the effects of doxorubicin. Using Hi-C, ChIP-seq, and RNA-seq, we explore the changes in chromatin architecture brought about by doxorubicin and ICRF193. Our results indicate that physiologically relevant doses of doxorubicin lead to a local reduction in Hi-C interactions in certain genomic regions that contain active promoters, with changes in chromatin architecture occurring independently of Top2 inhibition, cell cycle arrest, and differential gene expression. Inside the regions with decreased interactions, we detected redistribution of RAD21 around the peaks of H3K27 acetylation. Our study also revealed a common structural pattern in the regions with altered architecture, characterized by two large domains separated from each other. Additionally, doxorubicin was found to increase CTCF binding in H3K27 acetylated regions. Furthermore, we discovered that Top2-dependent chemotherapy causes changes in the distance decay of Hi-C contacts, which are driven by direct and indirect inhibitors. Our proposed model suggests that doxorubicin-induced DSBs cause cohesin redistribution, which leads to increased insulation on actively transcribed TAD boundaries. Our findings underscore the significant impact of genotoxic anticancer treatment on the chromatin structure of the human genome.


Assuntos
Cromatina , Cromossomos , Humanos , Fator de Ligação a CCCTC/genética , Sítios de Ligação , Cromossomos/metabolismo , Doxorrubicina/farmacologia
4.
Nat Genet ; 55(5): 880-890, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37142849

RESUMO

Extrachromosomal DNAs (ecDNAs) are common in cancer, but many questions about their origin, structural dynamics and impact on intratumor heterogeneity are still unresolved. Here we describe single-cell extrachromosomal circular DNA and transcriptome sequencing (scEC&T-seq), a method for parallel sequencing of circular DNAs and full-length mRNA from single cells. By applying scEC&T-seq to cancer cells, we describe intercellular differences in ecDNA content while investigating their structural heterogeneity and transcriptional impact. Oncogene-containing ecDNAs were clonally present in cancer cells and drove intercellular oncogene expression differences. In contrast, other small circular DNAs were exclusive to individual cells, indicating differences in their selection and propagation. Intercellular differences in ecDNA structure pointed to circular recombination as a mechanism of ecDNA evolution. These results demonstrate scEC&T-seq as an approach to systematically characterize both small and large circular DNA in cancer cells, which will facilitate the analysis of these DNA elements in cancer and beyond.


Assuntos
Neoplasias , Transcriptoma , Humanos , Transcriptoma/genética , DNA , Neoplasias/genética , Oncogenes , DNA Circular/genética
5.
Psychiatry Res ; 295: 113605, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33285347

RESUMO

A major barrier to clinicians referring service users with psychosis for psychological therapies is the belief that they will not engage. We investigated therapy receipt after discharge, in a sample of service users who had already demonstrated willingness to engage in psychological therapy during an inpatient admission. Only one-third of service users (33%; 16/48) received at least 1 session of evidence-based therapy at 6-month follow-up after discharge. Therapy receipt was more common for service users with (i) lower delusional distress at discharge, (ii) Black and Minority Ethnic (BME) background, and (iii) discharged to an Early Intervention (EI) service.


Assuntos
Medicina Baseada em Evidências/tendências , Hospitais Psiquiátricos/tendências , Pacientes Internados/psicologia , Admissão do Paciente/tendências , Transtornos Psicóticos/psicologia , Transtornos Psicóticos/terapia , Adulto , Terapia Cognitivo-Comportamental/tendências , Feminino , Seguimentos , Hospitalização/tendências , Humanos , Masculino , Alta do Paciente/tendências , Transtornos Psicóticos/diagnóstico
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