The conformational distribution and mutual interconversion of thermally activated delayed fluorescence (TADF) emitters significantly affect the exciton utilization. However, their influence on the ...photophysics in amorphous film states is still not known due to the lack of a suitable quantitative analysis method. Herein, we used temperature‐dependent time‐resolved photoluminescence spectroscopy to quantitatively measure the relative populations of the conformations of a TADF emitter for the first time. We further propose a new concept of “self‐doping” for realizing high‐efficiency nondoped OLEDs. Interestingly, this “compositionally” pure film actually behaves as a film with a dopant (quasi‐equatorial form) in a matrix (quasi‐axial form). The concentration‐induced quenching that may occur at high concentrations is thus expected to be effectively relieved. The “self‐doping” OLED prepared with the newly developed TADF emitter TP2P‐PXZ as a neat emitting layer realizes a high maximum external quantum efficiency of 25.4 % and neglectable efficiency roll‐off.
Until now, the influence of the conformational distribution on the photophysics and device performance of thermally activated delayed fluorescence (TADF) emitters has not been clear. Herein, conformational populations in disordered solid states are quantitatively measured for the first time. A high‐performance “self‐doping” OLED with a maximum external quantum efficiency of 25.4 % is achieved.
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Thermally activated delayed fluorescence (TADF) emitters with aggregation-induced emission (AIE) features are hot candidates for non-doped organic light-emitting diodes (OLEDs), as they are highly ...emissive in solid states upon photoexcitation. Nevertheless, not every AIE-TADF emitter in the past had guaranteed decent efficiencies in non-doped devices, indicating that the AIE character alone does not necessarily afford ideal non-doped TADF emitters. As intermolecular electron-exchange interaction that involves long-lived triplet excitons plays a dominant role in the whole quenching process of TADF, we anticipate that it is the main reason for the different electroluminescence performances of AIE-TADF emitters. Therefore, in this work, we designed two TADF emitters SPBP-DPAC and SPBP-SPAC by modifying a reported less successful emitter BP-DPAC with extra fluorenes to increase intermolecular distances and attenuate this electron-exchange interaction. With the fluorene lock as steric hindrance, SPBP-DPAC and SPBP-SPAC exhibit significantly higher exciton utilization in non-doped films due to the suppressed concentration quenching. The non-doped OLEDs based on SPBP-DPAC and SPBP-SPAC show an excellent maximum external quantum efficiency (EQE) of 22.8% and 21.3% respectively, and what's even more promising is that ignorable roll-offs at practical brightness (
e.g.
, 1000 and 5000 cd m
−2
) were realized. These results reveal that locking the phenyl rings as steric hindrance can not only enhance the molecular rigidity, but also cause immediate relief of concentration quenching, and result in significant performance improvement under non-doped conditions. Our approach proposes a feasible molecular modification strategy for AIE-TADF emitters, potentially increasing their applicability in OLEDs.
Two TADF emitters were developed by modifying a reported less successful emitter BP-DPAC with fluorene to suppress concentration quenching. Their non-doped OLEDs displayed excellent EQEs of 22.8% and 21.3% with well-suppressed roll-off.
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A sulfur (S) atom generally undergoes sp
3
hybridization when linking two moieties, not only for the sulfane status but also its fully oxidized form, sulfone. In the research reported here an S atom ...was used as a bridge to construct two thermally activated delayed fluorescence (TADF) emitters,
Trz-S-DMAc
and
Trz-SO
2
-DMAc
. The only difference between these two emitters is the valence of the S atoms in the bridges; however, their electron distributions are greatly affected and the charge-transfer (CT) transitions can be well-modulated between intermolecular and intramolecular modes. In a
Trz-S-DMAc
molecule, the S atom breaks the conjugation between donor (D) and acceptor (A) moieties, and their CT transition can only then occur with other
Trz-S-DMAc
molecules. The OLEDs based on
Trz-S-DMAc
achieve the best external quantum efficiency (EQE) of 18.1% at a high concentration of 55 wt% and maintain a satisfactory EQE of 13.0% for a non-doped device. Whereas for
Trz-SO
2
-DMAc
, the sulfone group acts as a second A moiety rather than a simple bridge. The
Trz-SO
2
-DMAc
is thus a typical TADF emitter with an effective intramolecular CT transition. The optimized OLED based on
Trz-SO
2
-DMAc
achieves a maximum EQE of 18.3%, whereas a significant efficiency drop can be observed with increasing doping concentrations. It is expected that these results will help to increase the understanding of how to link donor and acceptor moieties
via
sp
3
atoms to construct TADF emitters and the roles of the different CT transitions.
Changing the valence of a sulfur atom to form two novel thermally activated delayed fluorescence emitters with different charge transfer transitions.
In order to obtain the flame retardant silk fabric, silica sols and phytic
acid were prepared and applied to the silk fabrics. Vertical combustion
experiment, thermogravimetric analysis, Fourier ...transform infrared spectra
and smoke density test were used to investigate the combustion behavior,
thermal property, and kinetics model of silk fabrics before and after flame
retardant finish. The results showed that the sol coating on silk fabrics
could increase the carbon residue and hinder the spread of flame when
burning, and the tensile strength of treated silk was slightly damaged.
Furthermore, the kinetics model of silk thermal decomposition conformed to
Avrami-Erofeev model.
nema
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Effects of overdischarge on characteristics of lithium ion cells were deeply studied, and experiments have been made to reveal its mechanisms. The results suggest that overdischarge may result in ...large swelling of cells and degradation of recharge capabilities. The mechanism can be explained as that: a copper foil used as an anode collector will be oxidized to copper ion when deep overdischarge occurs and reduce at the anode in recharging progress, which greatly deteriorates the cell efficiency; solid electrolyte interface (SEI) film is to decompose and reform because of excessive de‐intercalation of lithium ions, and the released gas such as carbon dioxide makes the cell bulge. The experimental results prove that when 20% Li(Ni1/3Co1/3Mn1/3)O2 was added to LiCoO2 cathode materials, the cell swelling rate could be greatly reduced, and the recharge capability would be enhanced much.
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Cadmium, a highly toxic environmental pollutant, is reported to induce toxicity and apoptosis in multiple organs and cells, all possibly contributing to apoptosis in certain pathophysiologic ...situations. Previous studies have described that cadmium toxicity induces biochemical and physiological changes in the heart and finally leads to cardiac dysfunctions, such as decreasing contractile tension, rate of tension development, heart rate, coronary flow rate and atrioventricular node conductivity. Although many progresses have been made, the mechanism responsible for cadmium-induced cellular alternations and cardiac toxicity is still not fully understood. In the present study, we demonstrated that cadmium toxicity induced dramatic endoplasmic reticulum (ER) stress and impaired energy homoeostasis in cultured cardiomyocytes. Moreover, cadmium toxicity may inhibit protein kinase B (AKT)/mTOR (mammalian target of rapamycin) pathway to reduce energy productions, by either disrupting the glucose metabolism or inhibiting mitochondrial respiratory gene expressions. Our work will help to reveal a novel mechanism to clarify the role of cadmium toxicity to cardiomyocytes and provide new possibilities for the treatment of cardiovascular diseases related to cadmium toxicity.
Viral myocarditis (VM), a severe clinical condition characterized by cardiac inflammation, is most frequently induced as a result of coxsackievirus infection. Evidence suggests that microRNAs may ...have significant roles in the progression of cardiac injury during coxsackievirus infection. Concurrently, microRNA (miR)-214 was found to be upregulated in the plasma and myocardial cells during this process. In the present study, eight candidate miRNAs, the functions of which are associated with myocarditis, were selected and their expression levels were evaluated by reverse transcription-quantitative polymerase chain reaction. miR-146b and miR-214 were found to have significantly upregulated expression levels in the heart tissues of patients with VM compared with those of the control subjects. Predictions via the use of online bioin-formatics tools and confirmed by dual-luciferase assay and western blot analysis, revealed that ITCH, an NF-κB signaling suppressor, was a target gene of miR-214. To investigate the biological function of miR-214, tumor necrosis factor-α and interleukin-6 expression levels were evaluated in HeLa cell culture supernatant. The results revealed that miR-214 over-expression enhanced the expression of the two cytokines. In addition, the function of miR-214 was partially rescued by ITCH overexpression. Subsequently, concurrent results were obtained following experiments in murine cardiac myocytes. In conclusion, the results of the present study demonstrated that miR-214 contributed to the adverse inflammatory response to viral infection of the heart during coxsackievirus infection and is therefore a potential therapeutic target for the treatment of viral myocarditis.
The conformational distribution and mutual interconversion of thermally activated delayed fluorescence (TADF) emitters significantly affect the exciton utilization. However, their influence on the ...photophysics in amorphous film states is still not known due to the lack of a suitable quantitative analysis method. Herein, we used temperature‐dependent time‐resolved photoluminescence spectroscopy to quantitatively measure the relative populations of the conformations of a TADF emitter for the first time. We further propose a new concept of “self‐doping” for realizing high‐efficiency nondoped OLEDs. Interestingly, this “compositionally” pure film actually behaves as a film with a dopant (quasi‐equatorial form) in a matrix (quasi‐axial form). The concentration‐induced quenching that may occur at high concentrations is thus expected to be effectively relieved. The “self‐doping” OLED prepared with the newly developed TADF emitter TP2P‐PXZ as a neat emitting layer realizes a high maximum external quantum efficiency of 25.4 % and neglectable efficiency roll‐off.
Until now, the influence of the conformational distribution on the photophysics and device performance of thermally activated delayed fluorescence (TADF) emitters has not been clear. Herein, conformational populations in disordered solid states are quantitatively measured for the first time. A high‐performance „self‐doping“ OLED with a maximum external quantum efficiency of 25.4 % is achieved.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
To sequence the whole-genome of enterovirus 71 (EV71) srtain isolated from patient with hand, foot and mouth in Henan province in 2008.
Eight overlapping clones covering the whole viral genome were ...obtained by RT-PCR and the sequences were determined by Sanger dideoxg-mediated chain termination method.
Data it showed that the full length of enterovirus 71 (EV71) HENAN08 genome (not including Poly A tail) is 7405 bp. No deletion or insertion was detected in the coding region. There were several deletions and insertions in 5'UTR and 3'UTR regions. In P1 region, HENAN08 strain shared high homology with AnhuiFY08 strain, Zhejiang08 strain and SHZH strains (SHZH98, SHZH03) but low homology with Cox. A16. In P2 and P3 regions, HENAN08 strain shared higher nucleotide homology with Cox. A16 (81.7% and 83.7%) than that with BrCr and TW2086 strains. The phylogenetic analysis based on P1 region demonstrates that HENAN08 strain had the nearest genetic relationship with AnhuiFY and Zhejiang strains (isolated in 2008).
The
Aim： Nuciferine is an aporphine alkaloid extracted from lotus leaves, which is a raw material in Chinese medicinal herb for weight loss. In this study we used a network pharmacology approach to ...identify the anti-tumor activity of nuciferine and the underlying mechanisms. Methods： The pharmacological activities and mechanisms of nuciferine were identified through target profile prediction, clustering analysis and functional enrichment analysis using our traditional Chinese medicine （TCM） network pharmacology platform. The anti- tumor activity of nuciferine was validated by in vitro and in vivo experiments. The anti-tumor mechanisms of nuciferine were predicted through network target analysis and verified by in vitro experiments. Results： The nuciferine target profile was enriched with signaling pathways and biological functions, including ＂regulation of lipase activity＂, ＂response to nicotine＂ and ＂regulation of cell proliferation＂. Target profile clustering results suggested that nuciferine to exert anti-tumor effect. In experimental validation, nuciferine （0.8 mg/mL） markedly inhibited the viability of human neuroblastoma SY5Y cells and mouse colorectal cancer CT26 cells in vitro, and nuciferine （0.05 mg/mL） significantly suppressed the invasion of 6 cancer cell lines in vitro. Intraperitoneal injection of nuciferine （9.5 mg/mL, ip, 3 times a week for 3 weeks） significantly decreased the weight of SYSY and CT26 tumor xenografts in nude mice. Network target analysis and experimental validation in SY5Y and CT26 cells showed that the anti-tumor effect of nuciferine was mediated through inhibiting the PI3K-AKT signaling pathway and IL-1 levels in SY5Y and CT26 cells. Conclusion： By using a TCM network pharmacology method, nuciferine is neuroblastoma and mouse colorectal cancer in vitro and in vivo, through dentified as an anti-tumor agent against human nhibiting the PI3K-AKT signaling pathways and IL-1 levels
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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