The merging of photoredox catalysis and N‐heterocyclic carbene (NHC) catalysis for γ‐ and ϵ‐alkylation of enals with alkyl radicals was developed. The alkylation reaction of γ‐oxidized enals with ...alkyl halides worked well for the synthesis γ‐multisubstituted‐α,β‐unsaturated esters, including those with challenging vicinal all‐carbon quaternary centers. The synthesis of ϵ‐multisubstituted‐α,β‐γ,δ‐diunsaturated esters by an unprecedented NHC‐catalyzed ϵ‐functionalization was also established.
A merger: The merging of photoredox catalysis and N‐heterocyclic carbene (NHC) catalysis for γ‐ and ϵ‐alkylation of enals with alkyl halides was developed, giving the corresponding γ‐substituted α,β‐unsaturated esters and ϵ‐substituted α,β‐γ,δ‐diunsaturated esters exclusively in good yields.
In practical location problems on networks, the vertex demand is usually non-deterministic. This paper employs uncertainty theory to deal with this non-deterministic factor in single facility ...location problems. We first propose the concepts of satisfaction degree for both vertices and the whole network, which are used to evaluate products assignment. Based on different network satisfaction degree, two models are constructed. The solution to these models is based on Hakimi’s results, and some examples are given to illustrate these models.
Plant steroid hormones brassinosteroids (BRs) regulate plant growth and development at many different levels. Recent research has revealed that stress‐responsive NAC (petunia NAM and Arabidopsis ...ATAF1, ATAF2, and CUC2) transcription factor RD26 is regulated by BR signaling and antagonizes BES1 in the interaction between growth and drought stress signaling. However, the upstream signaling transduction components that activate RD26 during drought are still unknown. Here, we demonstrate that the function of RD26 is modulated by GSK3‐like kinase BIN2 and protein phosphatase 2C ABI1. We show that ABI1, a negative regulator in abscisic acid (ABA) signaling, dephosphorylates and destabilizes BIN2 to inhibit BIN2 kinase activity. RD26 protein is stabilized by ABA and dehydration in a BIN2‐dependent manner. BIN2 directly interacts and phosphorylates RD26 in vitro and in vivo. BIN2 phosphorylation of RD26 is required for RD26 transcriptional activation on drought‐responsive genes. RD26 overexpression suppressed the brassinazole (BRZ) insensitivity of BIN2 triple mutant bin2 bil1 bil2, and BIN2 function is required for the drought tolerance of RD26 overexpression plants. Taken together, our data suggest a drought signaling mechanism in which drought stress relieves ABI1 inhibition of BIN2, allowing BIN2 activation. Sequentially, BIN2 phosphorylates and stabilizes RD26 to promote drought stress response.
Significance Statement
RD26 is a key regulator of dehydration and drought tolerance in plants, however the post‐transcriptional regulation of RD26 is largely unknown. In this study, we found that BIN2, a GSK3‐like kinase, integrates upstream signaling of growth and drought stress to modulate RD26 through phosphorylation. Our findings provide a potential target to manipulate drought tolerance by engineering RD26 phosphorylation sites in crops and other commercially significant plants.
Axially chiral biaryl scaffolds are prevalent in natural products, chiral ligands, and organocatalysts. However, N‐heterocyclic carbene (NHC) catalyzed de novo construction of an aromatic ring with ...concomitant axial chirality induction for the synthesis of biaryl atropisomers is far less developed, and the efficient synthesis of axially chiral tetra‐ortho‐substituted biaryls remains an unsolved problem under NHC catalysis. Reported here is an NHC‐catalyzed de novo synthesis of axially chiral benzothiophene/benzofuran‐fused biaryls from enals and 2‐benzyl‐benzothiophene/benzofuran‐3‐carbaldehydes through a 2+4 annulation, decarboxylation, and oxidative aromatization cascade with central‐to‐axial chirality conversion. The developed method provides efficient and general access to novel axially chiral benzothiophene/benzofuran‐fused biaryls in high enantioselectivities and works well for the synthesis of tetra‐ortho‐substituted biaryls.
The N‐heterocyclic carbene catalyzed enantioselective de novo synthesis of axially chiral benzothiophene/benzofuran‐fused biaryls from enals and 2‐benzylbenzothiophene/benzofuran‐3‐carbaldehydes has been developed. This cascade process comprises a 2+4 annulation, decarboxylation, and oxidative aromatization with central‐to‐axial chirality conversion, allowing rapid access to atropoisomeric tri‐ and tetra‐ortho‐substituted biaryls with high enantioselectivities.
•We found a method to simplified the catalyst layer for calculate the transport properties.•We showed how to use lattice Boltzmann method to calculate flow rate and permeability.•We verified the ...lattice Boltzmann method for micro pore flow.
Gas flow in catalyst layer is important as it is the place where the electrochemical reactions take place. But it is challenging because the size of the pores is less than one micron and gas flow in the catalyst layer is no longer continuum, the Knudsen number cannot be neglected. As a result, the wall–gas collision must be re-considered, meaning that in the macroscopic models, the absolute permeability of the catalyst layer for different gases varies. To investigate this, we will simplify the pore geometry in catalyst layer into a bundle of tubes whose diameters can be derived from the pore-size distribution of the 3D (focused ion beam) FIB images. A model for gas flow in each tube is then simulated, the flow rate in the small pores have high resistance than big one, large difference start after pore size bigger than 100nm. Use the pore volume percentage with different pore size diameter and porosity, we have calculate the average cross section area of the catalyst layer and calculate the average flow rate based on them which is used for the permeability calculation later. This permeability value can reflect the permeability in the true catalyst. The results show that permeability of catalyst layer is not a constant but varies with Knudsen number, meaning that the permeability calculation in the micro/nano scale is depend on the Knudsen number. Assuming a constant permeability for all the gases, as used in the available fuel cell models in literature, could give rise to significant errors.
The way EFL students experience the process of learning has always been of utmost importance since it tremendously affects the amount of learning and received pleasure throughout this process for ...both teachers and students. From this aspect, both self-efficacious and committed teachers make a contribution to their organization's success. Even though many studies have been conducted about teachers' self-efficacy and their organizational commitment, a few of which concentrate their attention on the link between these two variables. To fill this gap, this review paper provides a glimpse at the underlying roles of teacher self-efficacy and their organizational commitment. Furthermore, it presents the definitions and applications of each construct. Finally, some implications and future recommendations are put forward to avid scholars.
N‐heterocyclic carbene (NHC)‐catalyzed enantioselective Mannich‐type reactions of the biomass‐derived platform compound 5‐(chloromethyl)furfural (CMF) with imines were developed. A series of ...high‐value‐added chiral amines were afforded in good to high yields with excellent regio‐ and enantioselectivities. The bifunctional NHC derived from ʟ‐pyroglutamic acid efficiently steered the remote addition of the trienolate intermediate to the imine in a highly stereocontrolled manner. This represents the first enantioselective reaction proceeding via an NHC‐bound trienolate intermediate.
NHC‐catalyzed enantioselective Mannich‐type reactions of 5‐(chloromethyl)furfural (CMF), an important biomass‐derived platform chemical, with aldimines afford chiral amines in good yields with excellent regio‐ and enantioselectivities. The use of a bifunctional NHC bearing a free hydroxy group enabled the remote addition of the trienolate intermediate to the imine to occur in a highly stereocontrolled manner.
Since universities' commitment to internationalisation has been increasing, instruments for measuring institutional internationalisation performance are urgently needed to monitor and evaluate the ...progress made about internationalisation. Although efforts have been made to develop various tools, an internationally applicable instrument for universities to measure and compare their internationalisation performance remains missing. This study attempted to develop an indicator framework of such kind to fill the gap. A total of 182 administrative staff and 17 policymakers from 17 flagship universities in Australia, Singapore and China were consulted in order to establish the framework. The study resulted in a set of 15 indicators that captures six key dimensions of university internationalisation. It attempts to cover internationalisation in its widest possible sense with practical number of indicators. This study also contributes to the knowledge body of developing measurement for university internationalisation by reflecting on the fundamental challenge of measuring the phenomenon. (HRK / Abstract übernommen).
Abstract
Computational detection methods have been widely used in studies on the biogenesis and the function of circular RNAs (circRNAs). However, all of the existing tools showed disadvantages on ...certain aspects of circRNA detection. Here, we propose an improved multithreading detection tool, CIRI2, which used an adapted maximum likelihood estimation based on multiple seed matching to identify back-spliced junction reads and to filter false positives derived from repetitive sequences and mapping errors. We established objective assessment criteria based on real data from RNase R-treated samples and systematically compared 10 circular detection tools, which demonstrated that CIRI2 outperformed its previous version CIRI and all other widely used tools, featured with remarkably balanced sensitivity, reliability, duration and RAM usage.
Recent studies reveal that circular RNAs (circRNAs) are a novel class of abundant, stable and ubiquitous noncoding RNA molecules in animals. Comprehensive detection of circRNAs from high-throughput ...transcriptome data is an initial and crucial step to study their biogenesis and function. Here, we present a novel chiastic clipping signal-based algorithm, CIRI, to unbiasedly and accurately detect circRNAs from transcriptome data by employing multiple filtration strategies. By applying CIRI to ENCODE RNA-seq data, we for the first time identify and experimentally validate the prevalence of intronic/intergenic circRNAs as well as fragments specific to them in the human transcriptome.
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