109 research outputs found
High triplet energy host materials for blue TADF OLEDsâA tool box approach
The synthesis of stable blue TADF emitters and the corresponding matrix materials is one of the biggest challenges in the development of novel OLED materials. We present six bipolar host materials based on triazine as an acceptor and two types of donors, namely, carbazole, and acridine. Using a tool box approach, the chemical structure of the materials is changed in a systematic way. Both the carbazole and acridine donor are connected to the triazine acceptor via a para- or a meta-linked phenyl ring or are linked directly to each other. The photophysics of the materials has been investigated in detail by absorption-, fluorescence-, and phosphorescence spectroscopy in solution. In addition, a number of DFT calculations have been made which result in a deeper understanding of the photophysics. The presence of a phenyl bridge between donor and acceptor cores leads to a considerable decrease of the triplet energy due to extension of the overlap electron and hole orbitals over the triazine-phenyl core of the molecule. This decrease is more pronounced for the para-phenylene than for the meta-phenylene linker. Only direct connection of the donor group to the triazine core provides a high energy of the triplet state of 2.97 eV for the carbazole derivative CTRZ and 3.07 eV for the acridine ATRZ. This is a major requirement for the use of the materials as a host for blue TADF emitters.We acknowledge funding through the EU Marie Sklodowska-Curie ITN TADFlife grant (GA. 812872). This work was also supported by the Universidad Carlos III de Madrid, the European Union's Seventh Framework Programme for research
Different preparation of Sodium-DNA for bone tissue regeneration
Current strategies for bone tissue regeneration involve the use of a wide range of biomaterials and synthetic bone substitutes; among them, Sodium-DNA could represent a new chance considering its osteoinductive properties (Nakamura et al., 2000; Bowler et a., 2001; Guizzardi et al., 2003; Guizzardi et al., 2007). The aim of this study was to evaluate the regenerative properties of two different preparation of Sodium- DNA (paste or liquid form) in a rat calvarial defect model. The cranium of each rat was shaved and a skin incision from the naso-frontal area to the external occipital protuberance was performed. The skin and the subcutaneous tissues were reflected to expose the full extent of the calvaria. Full-thickness 5X8 mm bone skull defects were made on each parietal region using piezoelectric surgery. Bone defects were filled with Sodium-DNA (paste or liquid form, Veritas, Brescia, Italy) alone or mixed with Bio-Oss (Geistlich, Wolhusen, Switzerland). Histomorphometric evaluation of bone regeneration was performed at the end of the treatments. The data obtained showed a time-dependent active bone healing process; however, differences in the use of past or liquid form were evident. These results suggest that Sodium-DNA could be considered an active biomaterial in bone regeneration, but an adequate formulation to obtain a better regenerative efficacy is needed
Ethmoidal arteries variability: an anatomical and radiological study
Understanding the location of ethmoidal arteries (EAs) is crucial during endo- scopic sinus surgery or skull base surgery. The aim of this study was to evaluate the anatomical variability of EAs, considering their presence and position within the ethmoid bone and their position in relation to the skull base (SB) and the frontal sinus (FS). Fourteen human heads underwent a cone-beam CT scan and an endoscopic dissection was carried out to evaluate the anatomy of the EAs. Several features were assessed both radiologically and in the lab setting: presence; position according to the â5 doors theoryâ (1); position respect to the SB; distance from the SB; relation with the FS (2); dehiscence of the bony canal. Anterior EA and posterior EA were present in all cases, whereas the prevalence of the middle EA was 28.57±16.73%. Anterior EA was most frequently found (64.29%) in the basal lamella of the middle turbinate; it originated from the SB in 60.71% of cases and it was separated from the FS by a single bony lamella in 46.43%. Its canal was dehiscent in 46.43±18.47%. Posterior EA was almost equally found posterior to the basal lamella of the middle turbinate, in the basal lamella of the superior turbinate and posterior to it. It was found in the SB in 82.14% of the cases and its canal was dehiscent in the 28.57±16.73%. Middle EA was found posterior to the basal lamella of the middle turbinate in 62.50% of cas- es and it was found in the SB in 75.00% of the cases. These data demonstrate that, despite their constant presence, anterior and posterior EAs showed a variable position and relationship with the SB; in addition, the data showed a non-negligible number of cases in which the middle MEA was present. Therefore, because of these several anatomical variability in EAs, a high-spatial-resolution CT should be provided for the preoperative anatomical assessment
Genotype and residual enzyme activity in medium-chain acyl-CoA dehydrogenase (MCAD) deficiency: Are predictions possible?
AbstractMediumâchain acylâCoA dehydrogenase deficiency (MCADD) is the most common defect of mitochondrial ÎČâoxidation. Confirmation diagnostics after newborn screening (NBS) can be performed either by enzyme testing and/or by sequencing of the ACADM gene. Here, we report the results from enzyme testing in lymphocytes with gene variants from molecular analysis of the ACADM gene and with the initial acylcarnitine concentrations in the NBS sample. From April 2013 to August 2019, in 388 individuals with characteristic acylcarnitine profiles suggestive of MCADD the octanoylâCoAâoxidation was measured in lymphocytes. In those individuals with residual activities 35% excluding MCADD. In the remaining 21 individuals, MCAD residual activity ranged from 30% to 35%. The latter group comprised both heterozygous carriers and individuals carrying two gene variants on different alleles. Twenty new variants could be identified and functionally classified based on their effect on enzyme function. C6 and C8 acylcarnitine species in NBS correlated with MCAD activity and disease severity. MCADD was only confirmed in half of the cases referred suggesting a higher false positive rate than expected. Measurement of the enzyme function in lymphocytes allowed fast confirmation diagnostics and clear determination of the pathogenicity of new gene variants. There is a clear correlation between genotype and enzyme function underlining the reproducibility of the functional measurement in vitro
Morphometric analysis of Huguierâs canal by Cone Beam CT
The middle ear and the stomatognatic system are closely anatomically and functionally related. The anterior chordal canal of Huguier connects the temporomandibular joint (TMJ) and the middle ear. This canal is formed by the inferior process of tegment tympani and the sphenoid bone and it is located at the medial end of the petrotympanic fissure. To data, few studies aimed to describe Huguierâs canal morphology and its related structures (Toth et al., 2006; Sato et al., 2008; Aristeguieta et al., 2009). The aim of this study is to describe the radiological anatomy of the Huguierâs canal using cone beam CT (CBCT, Scanora 3D, Soredex). We measured 438 Huguierâs canals from 219 human skulls (Section of Anthropology and Ethnology, Museum of Natural History, Florence, Italy). The measurements were made at three levels: 1) near the TMJ (lateral-glenoidal side) that was 1.961 ± 0.472 mm; 2) the narrowest point of the middle area that was 0.494 ± 0.24 mm; 3) near the middle ear (medial, acoustic meatus side) that was 1.085 ± 0.354 mm. 21 on 439 Huguierâs canal (4.79%) were ossificated: 1 only in the medial side, 11 only in the middle area and 9 in all the three levels. Considering the high number of measurements, the values obtained were comparable, suggesting that CBCT can be useful to detect these anatomical details
Substitution effects on a new pyridylbenzimidazole acceptor for thermally activated delayed fluorescence and their use in organic light-emitting diodes
The St Andrews team would like to thank the Leverhulme Trust (RPG-2016-047) for financial support. P.R. acknowledges support from a Marie SkĆodowska-Curie Individual Fellowship (MCIF; No. 749557). S.M.S acknowledges support from the Marie SkĆodowska-Curie Individual Fellowship, grant 27 agreement no. 838885 (NarrowbandSSL). Computational resources have been provided by the Consortium des Ăquipements de Calcul Intensif (CĂCI), funded by the Fonds de la Recherche Scientifiques de Belgique (F.R.S.-FNRS) under Grant No. 2.5020.11, as well as the Tier-1 supercomputer of the FĂ©dĂ©ration Wallonie-Bruxelles, infrastructure funded by the Walloon Region under the grant agreement n1117545. We acknowledge support from the European Unionâs Horizon 2020 research and innovation programme under the ITN TADFlife (GA 812872). Y.O. acknowledges funding by the Fonds de la Recherche Scientifique-FNRS under Grant n° F.4534.21 (MIS-IMAGINE). D.B. is a FNRS Research Director.In this work a new acceptor is used for use in thermally activated delayed fluorescence (TADF) emitters, pyridylbenzimidazole, which when coupled with phenoxazine allows efficient TADF to occur. N-functionalization of the benzimidazole using methyl, phenyl, and tert-butyl groups permits color tuning and suppression of aggregation-caused quenching (ACQ) with minimal impact on the TADF efficiency. The functionalized derivatives support a higher doping of 7 wt% before a fall-off in photoluminescence quantum yields is observed, in contrast with the parent compound, which undergoes ACQ at doping concentrations greater than 1 wt%. Complex conformational dynamics, reflected in the time-resolved decay profile, is found. The singletâtriplet energy gap, ÎEST, is modulated by N-substituents of the benzimidazole and ranges of between 0.22 and 0.32 eV in doped films. Vacuum-deposited organic light-emitting diodes, prepared using three of the four analogs, show maximum external quantum efficiencies, EQEmax, of 23.9%, 22.2%, and 18.6% for BIm(Me)PyPXZ , BIm(Ph)PyPXZ , and BImPyPXZ , respectively, with a correlated and modest efficiency roll-off at 100 cd mâ2 of 19% 13%, and 24% of the EQEmax, respectively.Publisher PDFPeer reviewe
The frontoethmoidal architecture: a developmental point of view
The anatomy of frontal sinus drainage pathway (FSDP) and surrounding spaces is extremely complex and variable. Its anatomical variability can be simplified based on the knowledge of the developmental mechanism of the frontal recess. The frontal sinus develops from the 13th week of intrauterine life to the age of twenty through a number of well-known steps of progressive extension within the frontal bone. Its development results from an upward epithelial migration of the anterior ethmoidal cells that penetrate the inferior aspect of the frontal bone between its two diploic plates. Even though this developmental theory is almost universally accepted, only few Authors focused on the formation of FSDP prior to the extramural pneumatization (1-2). The results of the present study conducted on 14 human heads match with the developmental model proposed by Terracol and Ardouin (2), in fact a number of significant associations are conform to the process of growing of the frontal sinus from one out of the three primordial cells (i.e. orbital, nasal, or bullar cell). In this model, renewed in view of the observation of the present study, the hierarchical order of growing among primordial cells determines the final frontoethmoidal architecture
CFTR function is impaired in a subset of patients with pancreatitis carrying rare CFTR variants
Background: Many affected by pancreatitis harbor rare variants of the cystic fibrosis (CF) gene, CFTR, which encodes an epithelial chloride/bicarbonate channel. We investigated CFTR function and the effect of CFTR modulator drugs in pancreatitis patients carrying CFTR variants. Methods: Next-generation sequencing was performed to identify CFTR variants. Sweat tests and nasal potential difference (NPD) assays were performed to assess CFTR function in vivo. Intestinal current measurement (ICM) was performed on rectal biopsies. Patient-derived intestinal epithelial monolayers were used to evaluate chloride and bicarbonate transport and the effects of a CFTR modulator combination: elexacaftor, tezacaftor and ivacaftor (ETI). Results: Of 32 pancreatitis patients carrying CFTR variants, three had CF-causing mutations on both alleles and yielded CF-typical sweat test, NPD and ICM results. Fourteen subjects showed a more modest elevation in sweat chloride levels, including three that were provisionally diagnosed with CF. ICM indicated impaired CFTR function in nine out of 17 non-CF subjects tested. This group of nine included five carrying a wild type CFTR allele. In epithelial monolayers, a reduction in CFTR-dependent chloride transport was found in six out of 14 subjects tested, whereas bicarbonate secretion was reduced in only one individual. In epithelial monolayers of four of these six subjects, ETI improved CFTR function. Conclusions: CFTR function is impaired in a subset of pancreatitis patients carrying CFTR variants. Mutations outside the CFTR locus may contribute to the anion transport defect. Bioassays on patient-derived intestinal tissue and organoids can be used to detect such defects and to assess the effect of CFTR modulators.</p
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