Asymmetric Decoration of a -Linked Bitriazine-Based Host for Highly Efficient and Stable Blue Phosphorescent Organic Light-Emitting Diodes.

High triplet energy hosts for blue phosphorescent organic light-emitting diodes were developed by decorating a -linked bitriazine core with carbazole and tetraphenylsilyl functional groups. A symmetric host with two carbazole units as the two triazine units of the core and an asymmetric host with one carbazole unit and one tetraphenylsilyl unit as the two triazine units were prepared. The triplet energy of these two hosts was 2.

Purely Spin-Vibronic Coupling Assisted Triplet to Singlet Up-Conversion for Real Deep Blue Organic Light-Emitting Diodes with Over 20% Efficiency and y Color Coordinate of 0.05.

Finding narrow-band, ultrapure blue thermally activated delayed fluorescence (TADF) materials is extremely important for developing highly efficient organic light-emitting diodes (OLEDs). Here, spin-vibronic coupling (SVC)-assisted ultrapure blue emitters obtained by joining two carbazole-derived moieties at a para position of a phenyl unit and performing substitutions using several blocking groups are presented. Despite a relatively large singlet-triplet gap (∆E ) of >0.

Effects of Substitution Position of Carbazole-Dibenzofuran Based High Triplet Energy Hosts to Device Stability of Blue Phosphorescent Organic Light-Emitting Diodes.

High triplet energy hosts were developed through the modification of the substitution position of carbazole units. Two carbazole-dibenzofuran-derived compounds, 9,9'-(dibenzo[b,d]furan-2,6-diyl)bis(9-carbazole) (26CzDBF) and 4,6-di(9-carbazol-9-yl)dibenzo[b,d]furan (46CzDBF), were synthesized for achieving high triplet energy hosts. In comparison with the reported hole transport type host, 2,8-di(9-carbazol-9-yl)dibenzo[b,d]furan (28CzDBF), 26CzDBF and 46CzDBF maintained high triplet energy over 2.

Rational Molecular Design of Azaacene-Based Narrowband Green-Emitting Fluorophores: Modulation of Spectral Bandwidth and Vibronic Transitions.

A series of green-emitting fluorophores based on a tetra-azaacene core is synthesized by introducing nitrile substituents at different positions. Their molecular structure-optical property relationship [i.e.

Design Approach of Lifetime Extending Thermally Activated Delayed Fluorescence Sensitizers for Highly Efficient Fluorescence Devices.

In this work, a design approach of three thermally activated delayed fluorescence (TADF) emitters to extend the device lifetime of the TADF sensitized fluorescent devices was studied. Three TADF materials, 5-{4,6-bis[4-(tert-butyl)phenyl]-1,3,5-triazin-2-yl}-2-(10,15-diphenyl-10,15-dihydro-5H-diindolo[3,2-a:3',2'-c]carbazol-5-yl)benzonitrile (tTCNTruX), 4-[3-cyano-4-(10,15-diphenyl-10,15-dihydro-5H-diindolo[3,2-a:3',2'-c]carbazol-5-yl)phenyl]-2,6-diphenylpyrimidine-5-carbonitrile (PCNTruX) and 4-(4-{10,15-bis[4-(tert-butyl)phenyl]-10,15-dihydro-5H-diindolo[3,2-a:3',2'-c]carbazol-5-yl}-3-cyanophenyl)-2,6-diphenylpyrimidine-5-carbonitrile (PCNtTruX), were synthesized as sensitizers for TADF-sensitized fluorescent organic light-emitting diodes. The two tTCNTruX and PCNtTruX TADF emitters were designed to have Dexter energy transfer with blocking groups either in the donor or acceptor unit of the donor-acceptor-type TADF sensitizer.

Rational Molecular Design of Highly Efficient Yellow-Red Thermally Activated Delayed Fluorescent Emitters: A Combined Effect of Auxiliary Fluorine and Rigidified Acceptor Unit.

Molecular design strategies are crucial to develop highly efficient and long-wavelength thermally activated delayed fluorescent (TADF) emitters because the inherent limitation of the energy gap law degrades the efficiency of the red or orange TADF emitters. To resolve the low efficiency issue, we designed and synthesized two TADF emitters, 4,4'-(6-(9,9-dimethylacridin-10(9)-yl)-7-fluoroquinoxaline-2,3-diyl)dibenzonitrile (FDQCNAc) and 11-(9,9-dimethylacridin-10(9)-yl)-12-fluorodibenzo[,]phenazine-3,6-dicarbonitrile (FBPCNAc), by utilizing fluorine and peripheral cyano-substituted quinoxaline and phenazine acceptors of 4,4'-(6-fluoroquinoxaline-2,3-diyl)dibenzonitrile (FDQCN) and 11-fluorodibenzo[,]phenazine-3,6-dicarbonitrile (FBPCN), respectively. A fluorine atom at the ortho position of the acridine donor acts as an auxiliary acceptor to minimize the singlet-triplet energy gap (Δ) below 0.

C1-, C2-, and C3-Modified Carbazole Derivatives as Promising Host Materials for Phosphorescent Organic Light-Emitting Diodes.

Herein we unveiled the synthetic approach to C1-, C2-, and C3-modified carbazoles for the first time and designed high-triplet-energy bipolar host materials for green phosphorescent organic light-emitting devices. The compounds revealed excellent performance with a maximum external quantum efficiency as high as 23.6% and extremely low-efficiency roll-off of 2.

Narrowband and Pure Violet Organic Emitter with a Full Width at Half Maximum of 14 nm and y Color Coordinate of Below 0.02.

Violet organic light-emitting diodes (OLEDs) with a very narrow emission spectrum with a full width at half maximum of 14 nm and y color coordinate of 0.02 are developed using a indolo[3,2,1-jk]carbazole-derived pure violet emitter. The violet emitter, 2,5,13,16-tetra-tert-butylindolo[3,2,1-jk]-indolo[1',2',3':1,7]indolo[2,3-b]carbazole (tDIDCz), is designed to have a very rigid molecular structure driven by the multiresonance-type core structure through the alternating carbon and nitrogen atoms.

Unexpected stent thrombus after minimally invasive direct coronary artery bypass in hybrid re-vascularisation.

The progress in anti-platelet therapy and percutaneous coronary intervention led to reconfigure indications of hybrid re-vascularisation. However, there are still some controversies over indication, timing and patient management during the procedure. The case discussed here is a patient who was diagnosed with myocardial infarction and treated with hybrid re-vascularisation.

Needlescopic lung biopsy for interstitial lung disease and indeterminate pulmonary nodules: a report on 65 cases.

Background: We evaluated the feasibility and accuracy of a needlescopic procedure for lung biopsies in patients with interstitial lung disease or indeterminate pulmonary nodules.

Methods: Sixty-five patients (36 women; mean age, 51.3 +/- 15.

Effects of additional pleurodesis with dextrose and talc-dextrose solution after video assisted thoracoscopic procedures for primary spontaneous pneumothorax.

Recurrence after thoracoscopic surgery for primary spontaneous pneumothorax is a lingering problem, and many intraoperative methods to induce pleural symphysis have been introduced. We analyzed the effects of chemical pleurodesis during thoracoscopic procedures. Between August 2003 and July 2005, 141 patients among indicated surgical treatment for primary spontaneous pneumothorax in two hospitals of our institution allowed this prospective study.

Mechanism of bar displacement and corresponding bar fixation techniques in minimally invasive repair of pectus excavatum.

Purpose: Bar displacement is a major complication in repair of pectus excavatum with the Nuss technique. Mechanisms of bar displacement have been elucidated by case-by-case analysis, and specific bar fixation techniques have been developed to deal with each mechanism. The efficacy of our bar fixation techniques is appraised.

PROSPECT-PSPP: an automatic computational pipeline for protein structure prediction.

Knowledge of the detailed structure of a protein is crucial to our understanding of the biological functions of that protein. The gap between the number of solved protein structures and the number of protein sequences continues to widen rapidly in the post-genomics era due to long and expensive processes for solving structures experimentally. Computational prediction of structures from amino acid sequence has come to play a key role in narrowing the gap and has been successful in providing useful information for the biological research community.