Acceleration of singlet‐triplet intersystem crossings (ISC) is instrumental in bolstering triplet exciton harvesting of multi‐resonance thermally activated delayed fluorescent (MR‐TADF) emitters. ...This work describes a simple gold(I) coordination strategy to enhance the spin‐orbit coupling of green and blue BN(O)‐based MR‐TADF emitters, which results in a notable increase in rate constants of the spectroscopically observed ISC process to 3×109 s−1 with nearly unitary ISC quantum yields. Accordingly, the resultant thermally‐stable AuI emitters attained large values of delayed fluorescence radiative rate constant up to 1.3×105/1.7×105 s−1 in THF/PMMA film while preserving narrowband emissions (FWHM=30–37 nm) and high emission quantum yields (ca. 0.9). The vapor‐deposited ultrapure‐green OLEDs fabricated with these AuI emitters delivered high luminance of up to 2.53×105 cd m−2 as well as external quantum efficiencies of up to 30.3 % with roll‐offs as low as 0.8 % and long device lifetimes (LT60) of 1210 h at 1000 cd m−2.
A simple gold(I) coordination strategy affords highly efficient narrowband green and blue multi‐resonance thermally activated delayed fluorescence with emission quantum yields of ca. 0.9 and considerably shortened lifetimes down to 5.5 μs. The resultant AuI emitters deliver ultrapure‐green OLEDs with external quantum efficiencies of up to 30.3 %, alongside diminished roll‐offs as low as 0.8 % and device lifetimes (LT60) of 1210 h at 1000 cd m−2.
Metal‐TADF (thermally activated delayed fluorescence) emitters hold promise in the development of next generation light‐emitting materials for display and lighting applications, examples of which ...are, however, largely confined to CuI and recently AuI, AgI, and AuIII emitters. Herein is described the design strategy for an unprecedented type of metal‐TADF emitter based on inexpensive tungsten metal chelated with Schiff base ligand that exhibit high emission quantum yields of up to 56 % in solutions and 84 % in thin‐film (5 wt % in 1,3‐bis(N‐carbazolyl)benzene, mCP) at room temperature. Femtosecond time‐resolved emission (fs‐TRE) spectroscopy and DFT calculations were undertaken to decipher the TADF properties. Solution‐processed OLEDs fabricated with the W‐TADF emitter demonstrated external quantum efficiency (EQE) and luminance of up to 15.6 % and 16890 cd m−2, respectively.
A lightbulb moment for WVI complexes: Incorporation of arylamino substituents into the ligand scaffold leads to the realization of the first WVI Schiff base complex with TADF properties, which shows Φem of 56 % in solution and 84 % in thin film at room temperature. High‐efficiency solution‐processed W‐OLEDs were fabricated, exhibiting a maximum EQE and luminance of up to 15.6 % and 16890 cd m−2, respectively.
Photoinduced hydroarylation of alkenes is an appealing synthetic strategy for arene functionalization. Herein, we demonstrated that aryl radicals generated from electron‐deficient aryl ...chlorides/bromides could be trapped by an array of terminal/internal aryl alkenes in the presence of Pt(O^N^C^N) under visible‐light (410 nm) irradiation, affording anti‐Markovnikov hydroarylated compounds in up to 95 % yield. Besides, a protocol for Pt(O^N^C^N)‐catalyzed intramolecular photocyclization of acrylanilides to give structurally diverse 3,4‐dihydroquinolinones has been developed.
In the presence of luminescent Pt(O^N^C^N) complexes under visible light (410 nm) irradiation, aryl radicals derived from reductive aryl‐chloride/bromide bond cleavage were trapped by aryl alkenes and afforded a series of anti‐Markovnikov hydroarylated compounds. Pt(O^N^C^N)‐catalyzed intramolecular photocyclization of acrylanilides gives structurally diverse 3,4‐dihydroquinolinones.
Voltage‐dependent, color‐tunable organic light‐emitting diodes (OLEDs) are appealing tools that can be used for the visualization of electronic output signal of sensors. Nonetheless, the ...literature‐reported color‐tunable OLEDs that have a simple single‐cell device structure suffer from relatively low efficiency, pronounced efficiency roll‐off, color‐aging, and short operation lifetime, all of which limit their practical applications. Here, a novel co‐host‐in‐double‐emissive‐layer (CHIDEL) device, designed to enhance the performance of color‐tunable OLEDs with the use of a single tetradentate PtO^N^C^N emitter, is described. When Pt‐X‐2 is used as a single emitter in an optimized CHIDEL device, a white OLED with tunable Commission International de I'Eclairage (CIE) coordinates from (0.47, 0.44) at 3 V to (0.36, 0.48) at 11 V, a high color rendering index of 82, and high external quantum efficiency (EQE) of up to 20.75% can be achieved. By using Pt‐X‐4 as a single emitter, the voltage‐dependent color‐tunable CHIDEL device, with CIE coordinates shifted from (0.56, 0.43) at 3 V to (0.42, 0.55) at 11 V, demonstrates a high luminance of beyond 90 000 cd m−2 and a high EQE of 23.23% at a luminance of 1300 cd m−2. A long‐lifetime time to 90% of the initial luminance (LT90) of almost 20 000 h is demonstrated for the color‐tunable OLED with Pt‐X‐4 emitting dopant.
High‐performance voltage‐dependent color‐tunable organic light‐emitting diodes (OLEDs) with a single PtO^N^C^N emitter are fabricated. The emission color can be tuned from warm white to natural white or from orange to yellowish green, depending upon the emitter used. High external quantum efficiency (23.23%), low efficiency roll‐off, long‐term stability (LT90 = 19 105 h) and continuously variable color enable these color‐tunable OLEDs to find applications in smart wearable devices.
•Fast assembly of large and complex metagenomic datasets up to hundreds of Gb.•Integration of advanced assembly practices gives better assembly quality.•CPU-based algorithms eliminate GPU-dependency, ...yet more memory-efficient and faster.
The study of metagenomics has been much benefited from low-cost and high-throughput sequencing technologies, yet the tremendous amount of data generated make analysis like de novo assembly to consume too much computational resources. In late 2014 we released MEGAHIT v0.1 (together with a brief note of Li et al. (2015) 1), which is the first NGS metagenome assembler that can assemble genome sequences from metagenomic datasets of hundreds of Giga base-pairs (bp) in a time- and memory-efficient manner on a single server. The core of MEGAHIT is an efficient parallel algorithm for constructing succinct de Bruijn Graphs (SdBG), implemented on a graphical processing unit (GPU). The software has been well received by the assembly community, and there is interest in how to adapt the algorithms to integrate popular assembly practices so as to improve the assembly quality, as well as how to speed up the software using better CPU-based algorithms (instead of GPU).
In this paper we first describe the details of the core algorithms in MEGAHIT v0.1, and then we show the new modules to upgrade MEGAHIT to version v1.0, which gives better assembly quality, runs faster and uses less memory. For the Iowa Prairie Soil dataset (252Gbp after quality trimming), the assembly quality of MEGAHIT v1.0, when compared with v0.1, has a significant improvement, namely, 36% increase in assembly size and 23% in N50. More interestingly, MEGAHIT v1.0 is no slower than before (even running with the extra modules). This is primarily due to a new CPU-based algorithm for SdBG construction that is faster and requires less memory. Using CPU only, MEGAHIT v1.0 can assemble the Iowa Prairie Soil sample in about 43h, reducing the running time of v0.1 by at least 25% and memory usage by up to 50%. MEGAHIT v1.0, exhibiting a smaller memory footprint, can process even larger datasets. The Kansas Prairie Soil sample (484Gbp), the largest publicly available dataset, can now be assembled using no more than 500GB of memory in 7.5days. The assemblies of these datasets (and other large metgenomic datasets), as well as the software, are available at the website https://hku-bal.github.io/megabox.
A panel of iridium(iii) porphyrin complexes containing axial N-heterocyclic carbene (NHC) ligand(s) were synthesized and characterized. X-ray crystal structures of the bis-NHC complexes Ir
(ttp)(IMe)
...
(
), Ir
(oep)(BIMe)
(
), Ir
(oep)(I
Pr)
(
) and Ir
(F
tpp)(IMe)
(
) display ruffled porphyrin rings with mesocarbon displacements of 0.483-0.594 Å and long Ir-C
bonds of 2.100-2.152 Å. Variable-temperature
H NMR analysis of
reveals that the macrocycle porphyrin ring inversion takes place in solution with an activation barrier of 40 ± 1 kJ mol
. The UV-vis absorption spectra of Ir
(por)-NHC complexes display split Soret bands. TD-DFT calculations and resonance Raman experiments show that the higher-energy Soret band is derived from the
MLCT dπ(Ir) → π*(por) transition. The near-infrared phosphorescence of Ir
(por)-NHC complexes from the porphyrin-based
(π, π*) state features broad emission bands at 701-754 nm with low emission quantum yields and short lifetimes (
< 0.01;
< 4 μs). Ir
(por)(IMe)
complexes (por = ttp and oep) are efficient photosensitizers for
O
generation (
= 0.64 and 0.88) and are catalytically active in the light-induced aerobic oxidation of secondary amines and arylboronic acid. The bis-NHC complexes exhibit potent dark cytotoxicity towards a panel of cancer cells with IC
values at submicromolar levels. The cytotoxicity of these complexes could be further enhanced upon light irradiation with IC
values as low as nanomolar levels in association with the light-induced generation of reactive oxygen species (ROS). Bioimaging of Ir
(oep)(IMe)
(
) treated cells indicates that this Ir complex mainly targets the endoplasmic reticulum. Ir
(oep)(IMe)
catalyzes the photoinduced generation of singlet oxygen and triggers protein oxidation, cell cycle arrest, apoptosis and the inhibition of angiogenesis. It also causes pronounced photoinduced inhibition of tumor growth in a mouse model of human cancer.
Dialogic teaching has been demonstrated to be conducive to the development of important competencies and skills such as creativity, communication skills and critical thinking skills. Yet, the ...literature confirms that teacher-student interactions in the classroom are predominantly monologic rather than dialogic across subjects, grades and countries. This article reports the results of a study that evaluates the effectiveness of a Philosophy for Children (P4C) programme in facilitating the development of dialogic and inquiry teaching in teachers in Hong Kong. In the study, training and support were provided for teachers to enable them to teach P4C to their students during Integrated Humanities and English lessons. P4C was found to help enhance the teachers' effectiveness in the classroom in terms of their ability to engage in dialogic and inquiry teaching. The findings of this study suggest that P4C plays a significant role in promoting the professional development of teachers.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Dialogic teaching has been demonstrated to be conducive to the development of such important competencies and skills as creativity, communication skills, and critical thinking skills. However, the ...literature confirms that teacher-student interactions in the classroom are predominantly monologic rather than dialogic across subjects, grades, and countries. This article reports the results of a study that assesses the effectiveness of a Philosophy for Children (P4C) programme in facilitating the development of dialogic and inquiry teaching in teachers in Hong Kong. In the study, training and support were provided for teachers to enable them to teach P4C to their students during Integrated Humanities and English lessons. P4C was found to help increase the teachers' effectiveness in the classroom in terms of their ability to engage in dialogic and inquiry teaching, to develop relevant curricular materials for such teaching, to reflect on their own teaching, to recognise their students' capacity for constructing knowledge through dialogic inquiry, to transfer the teaching strategies learned in P4C to other non-P4C lessons, and to identify and analyse philosophical concepts in the school curriculum. The findings of this study suggest that P4C plays a significant role in promoting the professional development of teachers.
This randomized, controlled trial assessed the efficacy of transarterial Lipiodol (Lipiodol Ultrafluide, Laboratoire Guerbet, Aulnay-Sous-Bois, France) chemoembolization in patients with unresectable ...hepatocellular carcinoma. From March 1996 to October 1997, 80 out of 279 Asian patients with newly diagnosed unresectable hepatocellular carcinoma fulfilled the entry criteria and randomly were assigned to treatment with chemoembolization using a variable dose of an emulsion of cisplatin in Lipiodol and gelatin-sponge particles injected through the hepatic artery (chemoembolization group, 40 patients) or symptomatic treatment (control group, 40 patients). One patient assigned to the control group secondarily was excluded because of unrecognized systemic metastasis. Chemoembolization was repeated every 2 to 3 months unless there was evidence of contraindications or progressive disease. Survival was the main end point. The chemoembolization group received a total of 192 courses of chemoembolization with a median of 4.5 (range, 1-15) courses per patient. Chemoembolization resulted in a marked tumor response, and the actuarial survival was significantly better in the chemoembolization group (1 year, 57%; 2 years, 31%; 3 years, 26%) than in the control group (1 year, 32%; 2 years, 11%; 3 years, 3%;
P = .002). When adjustments for baseline variables that were prognostic on univariate analysis were made with a multivariate Cox model, the survival benefit of chemoembolization remained significant (relative risk of death, 0.49; 95% CI, 0.29-0.81;
P = .006). Although death from liver failure was more frequent in patients who received chemoembolization, the liver functions of the survivors were not significantly different. In conclusion, in Asian patients with unresectable hepatocellular carcinoma, transarterial Lipiodol chemoembolization significantly improves survival and is an effective form of treatment. (H
EPATOLOGY 2002;35:1164-1171.)
Described here are sterically hindered tetradentate Pt(O^N^C^N) emitters (Pt‐1, Pt‐2, and Pt‐3) developed for stable and high‐performance green phosphorescent organic light‐emitting diodes (OLEDs). ...These Pt(II) emitters exhibit strong saturated green phosphorescence (λmax = 517–531 nm) in toluene and mCP thin films with emission quantum yields as high as 0.97, radiative rate constants (kr) as high as 4.4–5.3 × 105 s−1 and reduced excimer emission, and with a preferential horizontally oriented transition dipole ratio of up to 84%. Theoretical calculations show that p‐(hetero)arene substituents at the periphery of the ligand scaffolds in Pt‐1, Pt‐2, and Pt‐3 can i) enhance the spin‐orbit coupling (SOC) between the lower singlet excited states and the T1 state, and S0→Sn (n = 1 or 2) transition dipole moment, and ii) introducing additional SOC activity and the bright 1ILCTπ(carbazole)→π*(N^C^N) excited state (Pt‐2 and Pt‐3), which are the main contributors to the increased kr values. Utilizing these tetradentate Pt(II) emitters, green phosphorescent OLEDs are fabricated with narrow‐band electroluminescence (FWHM down to 36 nm), high external quantum efficiency, current efficiency up to 27.6% and 98.7 cd A−1, and an unprecedented device lifetime (LT95) of up to 9270 h at 1000 cd m−2 under laboratory conditions.
Operationally stable and high‐performance vapor‐deposited saturated green phosphorescent organic light‐emitting diodes are realized with robust and sterically hindered tetradentate Pt(O^N^C^N) emitters. The corresponding Pt‐based devices display EL spectra with full width at half maximum down to 36 nm, high external quantum efficiency and current efficiency of up to 27.6% and 98.7 cd A−1, respectively, alongside practical device lifetimes (LT95) of up to 9270 h at an initial luminance of 1000 cd m−2.
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