A new series of molecules, T1–T4, possessing thermally activated delayed fluorescence (TADF) have been strategically designed and synthesized. Molecules T1–T4 contain the dimethyl acridine as the ...electron donor, which is linked to either symmetrical or unsymmetrical diphenyl pyrimidine as an acceptor. In comparison to the ubiquitous triazine acceptor, the selection of pyrimidine as an acceptor has advantages of facile functionalization and less stabilized unoccupied π orbitals, so that the energy gap toward the blue region can be accessed. Together with acridine donors, the resulting donor–acceptor functional materials reveal remarkable TADF properties. In the solid state, molecules T1–T4 all exhibit intriguing mechanochromism. The crystal structures, together with spectroscopy and dynamics acquired upon application of stressing, lead us to propose two types of structural arrangement that give distinct emission properties, one with and the other without TADF. Upon fabricating organic light‐emitting diodes, the T1–T4 films prepared from sublimation all exhibit dominant TADF behavior; this accounts for their high performance: an electroluminescent emission at λ=490 nm, with an external quantum efficiency of 14.2 %, can be attained when T2 is used as an emitter.
Functional pyrimidine acceptors: A new series of molecules, T1–T4, possessing thermally activated delayed fluorescence (TADF) have been strategically designed and synthesized. Together with acridine donors, the resulting donor– acceptor functional materials reveal remarkable TADF properties. In the solid state, molecules T1–T4 also exhibit intriguing mechanochromism (see figure).
In an aim to study the potential application toward organic light-emitting diodes, a series of boron compounds NBN-1 to NBN-5 bearing 1-isoquinolinyl pyrazolate, phenyl, substituted aryl, or fused ...biphenyl appendages were designed and synthesized. Dual emissions specified as F1 and F2 bands were observed for NBN-1 and NBN-2 in various solvents. The F1 emission features solvent independence and is assigned to the intraligand ππ* transition (i.e., LE state) over the isoquinolinyl pyrazolate moiety, whereas the F2 band shows significant solvatochromism, which originates from the interligand charge transfer (i.e., CT state) from isoquinolinyl to aryl appendages. In comparison, NBN-3 bearing ortho-methyl on the phenyl appendages (cf. para-methyl for NBN-2) shows only F1 (LE) emission. In contrast, NBN-4 and NBN-5 with a fused biphenyl-like appendage reveal solely the F2 (CT) emission. Comprehensive time-resolved fluorescence measurements, in combination with the computational approach, let us propose the occurrence of a through-space, photoinduced electron transfer (PET) from the LE to CT states. Depending on the characteristic of aryl appendages, the energetics between LE and CT states play a key role for the locally excited LE versus interligand CT emission. A pre-equilibrium-type PET for NBN-1 and NBN-2 and hence dual emissions are observed, whereas the energetically unfavorable PET for NBN-3 leads to the LE emission only. The highly exergonic PET for NBN-4 and NBN-5 renders solely the CT emission. This work thus demonstrates a strategy of facile appendage tuning of boron compounds that can afford both the LE and interligand CT emissions spanning over the entire visible spectral region.
An approach to the total synthesis of the azo prostaglandins has been developed. The synthesis starts with the 5, 5-dimethyl-4-oxacyclopentenone photoadduct 21, which was made by using Baldwin's ...modification of the DeMayo reaction. Elaboration of the prostaglandin side chains from the photoadduct 21 is described. Bayer Villiger oxidation of the photoadduct 21 with MCPBA afforded the oxalactone 46, which on hydrolysis with aqueous methanol yielded the cyclobutane hydroxy ester 47. A one pot retroaldol followed by a Wittig reaction of 47 gave enone 48 with cis side chains. Attempts made to cause epimerization in order to yield the unnatural and natural trans side chain stereochemistry are described. The steps that need to be done in order to complete the total synthesis are outlined. Finally the synthesis of the azo compound 94 from the aldehyde 91, followed by the synthesis of the epimeric endoperoxides 95 and 96 by the biradical trapping technique('8) is described.
The objective of this study was to evaluate the effects of 25% and 35% arginine supplementation in partially alleviating the effects of necrotic enteritis (NE) challenge on the production ...performance, intestinal integrity, and relative gene expression of tight junction proteins and inflammatory cytokines in broilers. Four hundred and eighty 1-day-old chicks were randomly allocated to the 4 treatments- Uninfected + Basal, NE + Basal, NE + Arg 125%, and NE + Arg 135%. NE was induced by inoculating 1 × 104Eimeria maxima sporulated oocysts on d 14 and 1 × 108 CFU/bird C. perfringens on d 19, 20, and 21 of age by oral gavage. The NE challenge significantly decreased body weight gain (BWG) (p < 0.05) and increased the feed conversion ratio (FCR) (p < 0.05). On d 21, the NE challenge also increased the jejunal lesion score (p < 0.05) and relative gene expression of IL-10 and decreased the expression of the tight junction proteins occludin (p < 0.05) and claudin-4 (p < 0.05). The 125% arginine diet significantly increased intestinal permeability (p < 0.05) and the relative gene expression of iNOS (p < 0.05) and IFN-γ (p < 0.05) on d 21 and the bile anti-C. perfringens IgA concentration by 39.74% (p < 0.05) on d 28. The 135% arginine diet significantly increased the feed intake during d 0 – 28 (p < 0.05) and 0 to 35 (p < 0.05) and increased the FCR on d 0 to 35 (p < 0.05). The 135% and 125% arginine diet increased the spleen CD8+: CD4+ T-cell ratio on d 28 (p < 0.05) and 35 (p < 0.05), respectively. The 135% arginine diet increased the CT CD8+:CD4+ T-cell ratio on d 35 (p < 0.05). In conclusion, the 125% and 135% arginine diets did not reverse the effect of the NE challenge on the growth performance. However, the 125% arginine diet significantly increased the cellular and humoral immune response to the challenge. Hence, the 125% arginine diet could be used with other feed additives to improve the immune response of the broilers during the NE challenge.
Context: A step-by-step approach to harvesting stem cells from the pulp of permanent and deciduous teeth, the problems faced during culture, and the differences in the growth properties and ...morphology of cells obtained from both the sources has been discussed as a precursor to the use of these cells in therapy.
Aims: To isolate, culture, and study the morphology and growth characteristics of mesenchymal stem cells from the dental pulp of permanent teeth (dental pulp stem cells; DPSC) and exfoliated deciduous teeth (stem cells from human exfoliated deciduous; SHED).
Settings and Design : Cell culture study carried out at the Department of Oral and Maxillofacial Pathology, Ragas Dental College and Hospital, Chennai.
Materials and Methods: Fifteen permanent teeth and thirteen deciduous teeth from ten subjects were used. The growth characteristics and phenotype of cultured DPSCs and SHED were studied from the fourth passage on 24-well plates.
Statistical analysis used : Data analysis was done using SPSS ® version 10.05. Linear regression analysis was performed to derive the slope from growth curves and Mann-Whitney U test was performed to compare the fibroblastoid: epithelioid cell ratio between permanent and deciduous tooth pulp groups.
Results: Protocol for the culture of DPSC and SHED was standardized. DPSC and SHED populations were morphologically distinct. The cells from permanent tooth pulp showed a higher proportion of spindle-shaped fibroblastoid cells, whereas deciduous pulp culture showed a higher proportion of epithelioid cells. The seeding efficiency of DPSC - 88.9% (14 th permanent tooth pulp) and 91.7% (15 th permanent tooth pulp) was higher as compared to SHED - 84.25% (10 th deciduous tooth pulp).
Conclusions: Permanent and deciduous teeth are both viable sources of stem cells. The permanent teeth were easier to culture because of a lower chance of contamination with oral microflora. The growth characteristics of the cells obtained from both these sources were similar. However, there was a difference in the ratio of fibroblastoid cells to epithelioid cells between the cultures obtained from the permanent and deciduous teeth.
A step-by-step approach to harvesting stem cells from the pulp of permanent and deciduous teeth, the problems faced during culture, and the differences in the growth properties and morphology of ...cells obtained from both the sources has been discussed as a precursor to the use of these cells in therapy.
To isolate, culture, and study the morphology and growth characteristics of mesenchymal stem cells from the dental pulp of permanent teeth (dental pulp stem cells; DPSC) and exfoliated deciduous teeth (stem cells from human exfoliated deciduous; SHED).
Cell culture study carried out at the Department of Oral and Maxillofacial Pathology, Ragas Dental College and Hospital, Chennai.
Fifteen permanent teeth and thirteen deciduous teeth from ten subjects were used. The growth characteristics and phenotype of cultured DPSCs and SHED were studied from the fourth passage on 24-well plates.
Data analysis was done using SPSS ® version 10.05. Linear regression analysis was performed to derive the slope from growth curves and Mann-Whitney U test was performed to compare the fibroblastoid: epithelioid cell ratio between permanent and deciduous tooth pulp groups.
Protocol for the culture of DPSC and SHED was standardized. DPSC and SHED populations were morphologically distinct. The cells from permanent tooth pulp showed a higher proportion of spindle-shaped fibroblastoid cells, whereas deciduous pulp culture showed a higher proportion of epithelioid cells. The seeding efficiency of DPSC - 88.9% (14 th permanent tooth pulp) and 91.7% (15 th permanent tooth pulp) was higher as compared to SHED - 84.25% (10 th deciduous tooth pulp).
Permanent and deciduous teeth are both viable sources of stem cells. The permanent teeth were easier to culture because of a lower chance of contamination with oral microflora. The growth characteristics of the cells obtained from both these sources were similar. However, there was a difference in the ratio of fibroblastoid cells to epithelioid cells between the cultures obtained from the permanent and deciduous teeth.
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