Oligoene and cyanine features of tetracyano quinoidal oligothiophenes

This paper interprets a palette of spectroscopic data on tetracyano thienoquinoidal molecules of different sizes oriented towards the elucidation of their electronic behavior and other aspects of interest in materials chemistry. It also provides a contextualization of these properties between those of even oligoenes (carotene-like) and those of odd cyanines as a function of the reduction state. A complete UV-Vis-NIR electronic absorption, fluorescence emission and infrared spectroscopic study in part helped by quantum chemical calculations in the framework of the DFT theory has been carried out. The study encompasses the neutral and charged states. The optical properties of these compounds in the neutral state are controlled by the competition of bright (electric dipole–dipole allowed) and dark (electric dipole–dipole forbidden) singlet excited states. In the anionic state, the trimeric compounds disclose behaviors compatible with being either charge localized or delocalized mixed valence systems. Interestingly, we show the π-dimerization of a radical anion of a thienoquinoidal compound forming a π-dimer dianion as a manifestation of the delocalization of the charge in the charged monomer. The hexamer compound in the neutral state discloses incipient diradical character which permits the detection of a NIR emission band from the dark state at energies well below 1 eV. As thiophene benzo-annulation minimizes the diradical character, it forces the confinement of the charge in the vicinity of the terminal dicyanomethylene groups in the dianion. The oxidized species of the compounds have been also analyzed as models of charge localization states. The competition between doublet and quartet high spin states in the radical cations has been explored with the objective of visualizing potential molecules able to produce SOMO–HOMO energy inversion. (...)The authors thank the Spanish Ministry of Science, Innovation and Universities MCIU (PGC2018-098533-B-100 and RED2018-102815-T), and the Junta de Andalucı´a, Spain (UMA18FEDERJA057). We also thank the Research Central Services (SCAI) of the University of Málaga

Association between contrast extravasation on computed tomography scans and pseudoaneurysm formation in pediatric blunt splenic and hepatic injury: A multi-institutional observational study

PURPOSE: We aimed to examine the association between contrast extravasation (CE) on initial computed tomography (CT) scan and pseudoaneurysm (PSA) development in pediatric blunt splenic and/or liver injury. METHODS: We conducted a multi-institutional retrospective study in cases of blunt splenic and/or hepatic injury who underwent an initial attempt of nonoperative management. A logistic regression model was used to compare PSA formation and CE on initial CT scan, and the area under the receiver operating characteristic curve (AUC) with and without CE was used to assess the predictive performance of CE for PSA formation. RESULTS: Of 236 cases enrolled from 10 institutions, PSA formation was observed in 17 (7.2%). Multivariate analysis showed a significant association between CE on initial CT scan and increased incidence of PSA formation (odds ratio, 4.96; 95% confidence interval, 1.37-18.0). There was no statistically significant association between the grade of injury and PSA formation. The AUC improved from 0.75 (0.64-0.87) to 0.80 (0.70-0.91) with CE. CONCLUSION: Active CE on initial CT scan was an independent predictor of PSA formation. Selective use of follow-up CT in children who showed CE on initial CT may provide early identification of PSA formation, regardless of injury grade. LEVEL OF EVIDENCE: Prognostic and epidemiological, level III

GATA2 Mediates Thyrotropin-Releasing Hormone-Induced Transcriptional Activation of the Thyrotropin β Gene

Thyrotropin-releasing hormone (TRH) activates not only the secretion of thyrotropin (TSH) but also the transcription of TSHβ and α-glycoprotein (αGSU) subunit genes. TSHβ expression is maintained by two transcription factors, Pit1 and GATA2, and is negatively regulated by thyroid hormone (T3). Our prior studies suggest that the main activator of the TSHβ gene is GATA2, not Pit1 or unliganded T3 receptor (TR). In previous studies on the mechanism of TRH-induced activation of the TSHβ gene, the involvements of Pit1 and TR have been investigated, but the role of GATA2 has not been clarified. Using kidney-derived CV1 cells and pituitary-derived GH3 and TαT1 cells, we demonstrate here that TRH signaling enhances GATA2-dependent activation of the TSHβ promoter and that TRH-induced activity is abolished by amino acid substitution in the GATA2-Zn finger domain or mutation of GATA-responsive element in the TSHβ gene. In CV1 cells transfected with TRH receptor expression plasmid, GATA2-dependent transactivation of αGSU and endothelin-1 promoters was enhanced by TRH. In the gel shift assay, TRH signal potentiated the DNA-binding capacity of GATA2. While inhibition by T3 is dominant over TRH-induced activation, unliganded TR or the putative negative T3-responsive element are not required for TRH-induced stimulation. Studies using GH3 cells showed that TRH-induced activity of the TSHβ promoter depends on protein kinase C but not the mitogen-activated protein kinase, suggesting that the signaling pathway is different from that in the prolactin gene. These results indicate that GATA2 is the principal mediator of the TRH signaling pathway in TSHβ expression

Naphtho[1,2‑<i>c</i>:5,6‑<i>c</i>′]bis[1,2,5]thiadiazole-Based Nonfullerene Acceptors: Effect of Substituents on the Thiophene Unit on Properties and Photovoltaic Characteristics

The development of new electron-accepting π-conjugated systems for application as nonfullerene acceptors in organic solar cells (OSCs) is urgently needed. Although π-conjugated systems based on naphtho­[1,2-<i>c</i>:5,6-<i>c</i>′]­bis­[1,2,5]­thiadiazole (<b>NTz</b>) and naphthalimide (<b>Np</b>) as central and terminal units, respectively, represent possible candidates for nonfullerene acceptors, our knowledge of the structure–property–device performance relationship of these compounds remains limited. We report herein on an investigation of the effect of the substituents on the thiophene (<b>T</b>) linker between <b>NTz</b> and <b>Np</b> on the properties and photovoltaic performance. The photophysical and physicochemical measurements showed that the absorption behavior as well as frontier-orbital energy levels can be fine-tuned by the choice of the substituent on the thiophene rings. Bulk-heterojunction-type OSCs based on these acceptors under blending with poly­(3-hexylthiophene) as a donor showed various power conversion efficiencies, ranging from 0.26 to 2.14%. The substituents on the thiophene rings also have a significant influence on the blend film properties, which explain the differences in the short-circuit current densities and fill factors in the OSCs. These results indicate the importance of molecular design in preparing nonfullerene acceptors with <b>NTz</b> and <b>Np</b> units in terms of tuning both the molecular properties of the materials and donor–acceptor interface engineering in the blended films