Chiral conjugated polymer has promoted the development of the efficient circularly polarized electroluminescence (CPEL) device, nevertheless, it remains a challenge to develop chiral polymers with ...high electroluminescence performance. Herein, by the acceptor copolymerization of axially chiral biphenyl emitting skeleton and benzophenone, a pair of axially chiral conjugated polymers namely R‐PAC and S‐PAC are synthesized. The target polymers exhibit obvious thermally activated delayed fluorescence (TADF) activities with high photoluminescence quantum yields of 81%. Moreover, the chiral polymers display significant circularly polarized luminescence features, with luminescence dissymmetry factor (|glum|) of nearly 3 × 10−3. By using the chiral polymers as emitters, the corresponding circularly polarized organic light‐emitting diodes (CP‐OLEDs) exhibit efficient CPEL signals with electroluminescence dissymmetry factor |gEL| of 3.4 × 10−3 and high maximum external quantum efficiency (EQEmax) of 17.8%. Notably, considering both EQEmax and |gEL| comprehensively, the device performance of R‐PAC and S‐PAC is the best among all the reported CP‐OLEDs with chiral conjugated polymers as emitters. This work provides a facile approach to constructing chiral conjugated TADF polymers and discloses the potential of axially chiral conjugated luminescent skeletons in architecting high‐performance CP‐OLEDs.
Axially chiral conjugated polymers with thermally activated delayed fluorescence features are synthesized by copolymerizing chiral unit and benzophenone acceptor. By using the obtained polymers as emitters, high‐performance solution‐processed circularly polarized organic light‐emitting diodes are fabricated featuring efficient circularly polarized electroluminescence properties with the maximum external quantum efficiency and dissymmetry factor of up to 17.8% and 3.4 × 10‐3, respectively.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated (Cas) systems have revolutionized biological and biomedical sciences in many ways. The last few years have ...also seen tremendous interest in deploying the CRISPR-Cas toolbox for analytical and diagnostic assay development because CRISPR-Cas is one of the most powerful classes of molecular machineries for the recognition and manipulation of nucleic acids. In the short period of development, many CRISPR-enabled assays have already established critical roles in clinical diagnostics, biosensing, and bioimaging. We describe in this review the recent advances and design principles of CRISPR mediated analytical tools with an emphasis on the functional roles of CRISPR-Cas machineries as highly efficient binders and molecular scissors. We highlight the diverse engineering approaches for molecularly modifying CRISPR-Cas machineries and for devising better readout platforms. We discuss the potential roles of these new approaches and platforms in enhancing assay sensitivity, specificity, multiplexity, and clinical outcomes. By illustrating the biochemical and analytical processes, we hope this review will help guide the best use of the CRISPR-Cas toolbox in detecting, quantifying and imaging biologically and clinically important molecules and inspire new ideas, technological advances and engineering strategies for addressing real-world challenges such as the on-going COVID-19 pandemic.
A comprehensive review that offers mechanistic insight into the CRISPR-Cas toolbox for analytical and diagnostic assay development.
An efficient aryl to vinyl 1,4‐palladium migration/Heck sequence was developed for the stereoselective synthesis of 1,3‐dienes. High stereoselectivity was observed not only for 1,3‐dienes bearing two ...similar aryl groups at terminal positions, but also for those with configurations shown to be unfavorable with previous methods.
1,4 all: An efficient aryl to vinyl 1,4‐palladium/Heck sequence has been developed for the stereoselective synthesis of 1,3‐dienes. High stereoselectivity was observed not only for 1,3‐dienes bearing two similar aryl groups at terminal positions, but also for those with configurations shown to be unfavorable with previous methods.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The first asymmetric hydrogenation of 3‐ylidenephthalides has been developed using the IrI complex of a spiro4,4‐1,6‐nonadiene‐based phosphine‐oxazoline ligand (SpinPHOX) as the catalyst, affording a ...wide variety of chiral 3‐substituted phthalides in excellent enantiomeric excesses (up to 98 % ee). The utility of the protocol has been demonstrated in the asymmetric synthesis of chiral drugs NBP and BZP precursor, as well as the natural products chuangxinol and typhaphthalide.
A shortcut to a wide variety of chiral 3‐substituted phthalides with pharmacological interests has been realized by SpinPHOX/Ir catalyzed asymmetric hydrogenation of 3‐ylidenephthalides in high enantioselectivities (up to 98 % ee).
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
A sequential cross‐coupling/annulation of ortho‐vinyl bromobenzenes with aromatic bromides was realized, providing a direct and modular approach to access polycyclic aromatic compounds. A ...vinyl‐coordinated palladacycle was proposed as the key intermediate for this sequential process. Excellent chemoselectivity and regioselectivity were observed in this transformation. The practicability of this method is highlighted by its broad substrate scope, excellent functional group tolerance, and rich transformations associated with the obtained products.
Palladium catalysis: A sequential cross‐coupling/annulation of ortho‐vinyl bromobenzenes with aromatic bromides is realized in a direct and modular approach to access polycyclic aromatic compounds. A C(vinyl), C(aryl)‐palladacycle species is proposed as the key intermediate. High chemo‐ and regioselectivity, broad substrate scope, and excellent functional group tolerance are observed for this transformation.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Many applications of CRISPR/Cas9-mediated genome editing require Cas9-induced non-homologous end joining (NHEJ), which was thought to be error prone. However, with directly ligatable ends, ...Cas9-induced DNA double strand breaks may be repaired preferentially by accurate NHEJ.
In the repair of two adjacent double strand breaks induced by paired Cas9-gRNAs at 71 genome sites, accurate NHEJ accounts for about 50% of NHEJ events. This paired Cas9-gRNA approach underestimates the level of accurate NHEJ due to frequent + 1 templated insertions, which can be avoided by the predefined Watson/Crick orientation of protospacer adjacent motifs (PAMs). The paired Cas9-gRNA strategy also provides a flexible, reporter-less approach for analyzing both accurate and mutagenic NHEJ in cells and in vivo, and it has been validated in cells deficient for XRCC4 and in mouse liver. Due to high frequencies of precise deletions of defined "3n"-, "3n + 1"-, or "3n + 2"-bp length, accurate NHEJ is used to improve the efficiency and homogeneity of gene knockouts and targeted in-frame deletions. Compared to "3n + 1"-bp, "3n + 2"-bp can overcome + 1 templated insertions to increase the frequency of out-of-frame mutations. By applying paired Cas9-gRNAs to edit MDC1 and key 53BP1 domains, we are able to generate predicted, precise deletions for functional analysis. Lastly, a Plk3 inhibitor promotes NHEJ with bias towards accurate NHEJ, providing a chemical approach to improve genome editing requiring precise deletions.
NHEJ is inherently accurate in repair of Cas9-induced DNA double strand breaks and can be harnessed to improve CRISPR/Cas9 genome editing requiring precise deletion of a defined length.
To solve the problem of trajectory tracking control for quadrotor UAV with control input saturation, a novel prescribed performance backstepping dynamic surface control scheme is proposed in the ...presence of the model uncertainties and unknown external disturbances. In this work, the hyperbolic tangent function is introduced to solve the problem of control input saturation, and construct an auxiliary equation to reduce the saturation effect. Furthermore, the method introduces prescribed performance function, and converts the original constrained system into an equivalent unconstrained system through error transformation. Subsequently, dynamic surface technology is introduced to reduce the complexity of the control algorithm. At the same time, the nonlinear extended state observer is designed to estimate the generalised disturbance of the aircraft system. Finally, the Lyapunov function is selected to prove that all signals of the closed-loop system are uniformly ultimately bounded. Taking DJI M100 aircraft as the simulation object, the results show that the designed controller can effectively solve the problem of control input constraints and enable the system to reach the prescribed transient and steady-state tracking performance indexes.
Full text
Available for:
BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
The aryl to vinyl palladium 1,4-migration was realized for the first time. The generated alkenyl palladium species was trapped by diboron reagents under Miyaura borylation conditions, providing a new ...method to synthesize β,β-disubstituted vinylboronates. The excellent regioselectivity and broad substrate scope were observed for this novel transformation.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
A Pd(II)-catalyzed C–H phosphorylation reaction has been developed using heterocycle-directed ortho-palladation. Both H-phosphonates and diaryl phosphine oxides are suitable coupling partners for ...this reaction.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
The asymmetric rhodium‐catalyzed alkenylation of enones and imines with arylboronic acids has been developed. A highly controllable aryl to vinyl 1,4‐rhodium migration is the key step. Stereodefined ...vinyl moieties were installed in excellent enantioselectivies for most examined examples. DFT calculations reveal that the driving force of this rhodium migration is a kinetically favored process.
The asymmetric rhodium‐catalyzed alkenylation of enones and imines with arylboronic acids has been developed. A highly controllable aryl to vinyl 1,4‐rhodium migration is the key step. Stereodefined vinyl moieties were installed in excellent enantioselectivies for most examined examples. DFT calculations reveal that the driving force of this rhodium migration is a kinetically favored process.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
PDF
