Herein we describe a photochemical approach towards oxindoles by the radical cascade reaction of α,β-unsaturated N-arylacryl amides with alkyl bromides or iodides upon visible light irradiation. This ...transition metal- and photosensitizer-free protocol afforded diverse oxindoles with C3 quaternary centers in high product yields under mild reaction conditions. Importantly, the method was applicable to prepare the core skeletons of (±)-physovenine, (±)-esermethole and (±)-physostigmine.
The realization of high-efficiency solution-processed organic light-emitting diodes (OLEDs) using phosphorescent tetradentate Pt(II) emitters and bipolar organic hosts is demonstrated in this work. ...To investigate the effect of organic host on the platinum dopant, the performances of solution-processed Pt-OLEDs with various combinations between four tetradentate Pt(II) emitters, including two newly developed tetra-Pt-S2 and tetra-Pt-S3 and three bipolar organic hosts m-TPAPy, o-TPAPy, and o-CzPy, have been analyzed and compared. Among the tetradentate Pt(II) complexes studied in this work, tetra-Pt-S3 exhibited the best electroluminescent performance attributable to its bulky molecular scaffold structure, high emission quantum yield, and good solubility in common organic solvents. High external quantum efficiencies (EQEs) of up to 22.4% were achieved in the solution-processed OLED with tetra-Pt-S3 emitter and m-TPAPy host at the dopant concentration of 4 wt %. At a high luminance of 1000 cd m–2, the EQE of this device decreased slightly to 21.0%.
Organic Light‐Emitting Diodes
In article number 2307393, Gang Cheng, Lei Dai, Chi‐Ming Che, and co‐workers realized operationally stable and high‐performance vapor‐deposited green phosphorescent ...organic light‐emitting diodes with 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 CE of up to 27.6% and 98.7 cd A−1, respectively, alongside practical device lifetimes (LT95) of up to 9270 hours at an initial luminance of 1000 cd m−2.
Next-generation sequencing (NGS) enables unbiased detection of pathogens by mapping the sequencing reads of a patient sample to the known reference sequence of bacteria and viruses. However, for a ...new pathogen without a reference sequence of a close relative, or with a high load of mutations compared to its predecessors, read mapping fails due to a low similarity between the pathogen and reference sequence, which in turn leads to insensitive and inaccurate pathogen detection outcomes.
We developed MegaPath, which runs fast and provides high sensitivity in detecting new pathogens. In MegaPath, we have implemented and tested a combination of polishing techniques to remove non-informative human reads and spurious alignments. MegaPath applies a global optimization to the read alignments and reassigns the reads incorrectly aligned to multiple species to a unique species. The reassignment not only significantly increased the number of reads aligned to distant pathogens, but also significantly reduced incorrect alignments. MegaPath implements an enhanced maximum-exact-match prefix seeding strategy and a SIMD-accelerated Smith-Waterman algorithm to run fast.
In our benchmarks, MegaPath demonstrated superior sensitivity by detecting eight times more reads from a low-similarity pathogen than other tools. Meanwhile, MegaPath ran much faster than the other state-of-the-art alignment-based pathogen detection tools (and compariable with the less sensitivity profile-based pathogen detection tools). The running time of MegaPath is about 20 min on a typical 1 Gb dataset.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The recent release of the gene-targeted metagenomics assembler Xander has demonstrated that using the trained Hidden Markov Model (HMM) to guide the traversal of de Bruijn graph gives obvious ...advantage over other assembly methods. Xander, as a pilot study, indeed has a lot of room for improvement. Apart from its slow speed, Xander uses only 1 k-mer size for graph construction and whatever choice of k will compromise either sensitivity or accuracy. Xander uses a Bloom-filter representation of de Bruijn graph to achieve a lower memory footprint. Bloom filters bring in false positives, and it is not clear how this would impact the quality of assembly. Xander does not keep track of the multiplicity of k-mers, which would have been an effective way to differentiate between erroneous k-mers and correct k-mers.
In this paper, we present a new gene-targeted assembler MegaGTA, which attempts to improve Xander in different aspects. Quality-wise, it utilizes iterative de Bruijn graphs to take full advantage of multiple k-mer sizes to make the best of both sensitivity and accuracy. Computation-wise, it employs succinct de Bruijn graphs (SdBG) to achieve low memory footprint and high speed (the latter is benefited from a highly efficient parallel algorithm for constructing SdBG). Unlike Bloom filters, an SdBG is an exact representation of a de Bruijn graph. It enables MegaGTA to avoid false-positive contigs and to easily incorporate the multiplicity of k-mers for building better HMM model. We have compared MegaGTA and Xander on an HMP-defined mock metagenomic dataset, and showed that MegaGTA excelled in both sensitivity and accuracy. On a large rhizosphere soil metagenomic sample (327Gbp), MegaGTA produced 9.7-19.3% more contigs than Xander, and these contigs were assigned to 10-25% more gene references. In our experiments, MegaGTA, depending on the number of k-mers used, is two to ten times faster than Xander.
MegaGTA improves on the algorithm of Xander and achieves higher sensitivity, accuracy and speed. Moreover, it is capable of assembling gene sequences from ultra-large metagenomic datasets. Its source code is freely available at https://github.com/HKU-BAL/megagta .
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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 (λ
= 517-531 nm) in toluene and mCP thin films with emission quantum yields as high as 0.97, radiative rate constants (k
) as high as 4.4-5.3 × 10
s
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 T
state, and S
→S
(n = 1 or 2) transition dipole moment, and ii) introducing additional SOC activity and the bright
ILCTπ(carbazole)→π*(N^C^N) excited state (Pt-2 and Pt-3), which are the main contributors to the increased k
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
, and an unprecedented device lifetime (LT
) of up to 9270 h at 1000 cd m
under laboratory conditions.
This study examined the prevalence and correlates of mental illness in homeless people in Hong Kong and explored the barriers preventing their access to health care. Ninety-seven Cantonese-speaking ...Chinese who were homeless during the study period were selected at random from the records of the three organisations serving the homeless population. The response rate was 69%. Seventeen subjects could not give valid consent due to their poor mental state, so their responses were excluded from the data analysis. A psychiatrist administered the Structured Clinical Interview for DSM-IV Axis-I disorders (SCID-I) and the Mini -Mental State Examination. Consensus diagnoses for subjects who could not complete the SCID-I were established by three independent psychiatrists.
The point prevalence of mental illness was 56%. Seventy-one percent of the subjects had a lifetime history of mental illness, 30% had a mood disorder, 25% had an alcohol use disorder, 25% had a substance use disorder, 10% had a psychotic disorder, 10% had an anxiety disorder and 6% had dementia. Forty-one percent of the subjects with mental illness had undergone a previous psychiatric assessment. Only 13% of the subjects with mental illness were receiving psychiatric care at the time of interview. The prevalence of psychotic disorders, dementia and the rate of under treatment are hugely underestimated, as a significant proportion (18%) of the subjects initially selected were too ill to give consent to join the study.
The low treatment rate and the presence of this severely ill and unreached group of homeless people reflect the fact that the current mode of service delivery is failing to support the most severely ill homeless individuals.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
High-performance organic light-emitting diodes (OLEDs) were realized by utilizing three robust platinum(
ii
) complexes bearing tetradentate O^N^C^N ligands with a bridging tertiary amine (
...tetra-Pt-N
), a biphenyl group with a spiro linkage (
tetra-Pt-S
) or a sterically encumbered 2,6-dimethyl-4-
tert
-butylphenyl moiety (
tetra-Pt-M
). By using a double-host emissive layer (EML) structure and a 10 nm-thick interlayer between the EML and the electron-transport layer (ETL), a maximum power efficiency of over 100 lm W
−1
, a low turn-on voltage of less than 2.5 V and low efficiency roll-off were achieved. A high external quantum efficiency (EQE) of 19.4% and 20.3% was maintained at 10 000 cd m
−2
in OLEDs with
tetra-Pt-N
and
tetra-Pt-M
, respectively. Such high efficiency at high luminance could be attributed to the effective suppression of triplet-triplet annihilation (TTA) in our optimized device structure.
Double-host OLEDs with three bulky tetradentate Pt(O^N^C^N) emitters achieve a high EQE
max
of >20%, a PE
max
of >100 lm W
−1
, and low efficiency roll-off within 10 000 cd m
−2
.
A silica‐supported gold nanoparticle catalyst AuNPs/SiO2 (A) has been prepared by deposition of in situ synthesized gold nanoparticles (AuNPs) onto the surface of silica. A simple method that uses A ...as the catalyst and oxygen as the oxidant is effective for oxidative cyclization of anilines with aldehydes to form quinolines in a one‐pot reaction (20 examples; product yields up to 95 %). The “AuNPs/SiO2+O2” protocol is applicable to the synthesis of nitrogen‐containing polyheterocyclic compounds in good to excellent product yields by using bulky polycyclic anilines as the starting materials (10 examples; product yields up to 96 %). The A catalyst can be easily recovered by centrifugation and reused for seven consecutive runs without significant loss of catalytic activity.
Silica supported gold catalyst: Nitrogen‐containing polyheterocyclic compounds can be synthesized in good to excellent product yields (up to 96 % yield, 30 examples) by means of a one‐pot aerobic oxidative cyclization reaction by using narrowly dispersed gold nanoparticles on SiO2 (AuNPs/SiO2, A) as an efficient catalyst (see figure). The catalyst A could be easily recovered by centrifugation and recycled without significant loss of catalytic activity.
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