Abstract
A photoredox/copper co‐catalyzed ring‐opening cross‐coupling of aryl azides with cyclopropanols has been developed with
fac
‐Ir(ppy)
3
as the photocatalyst. The reaction involves ...intermediacy of the anilino radical generated through reduction of the azido group by
fac
‐Ir(ppy)
3
* and Cu
II
‐enabled oxidative ring‐opening of the cyclopropanol. An array of β‐aminoketone compounds were synthesized under redox‐neutral conditions by using this method.
In recent years, long noncoding RNAs (lncRNAs) have been shown to have critical regulatory roles in cancer biology. However, the contributions of lncRNAs to hepatitis B virus (HBV)‐related ...hepatocellular carcinoma (HCC) remain largely unknown. Differentially expressed lncRNAs between HBV‐related HCC and paired peritumoral tissues were identified by microarray and validated using quantitative real‐time polymerase chain reaction. Liver samples from patients with HBV‐related HCC were analyzed for levels of a specific differentially expressed lncRNA High Expression In HCC (termed lncRNA‐HEIH); data were compared with survival data using the Kaplan‐Meier method and compared between groups by the log‐rank test. The effects of lncRNA‐HEIH were assessed by silencing and overexpressing the lncRNA in vitro and in vivo. The expression level of lncRNA‐HEIH in HBV‐related HCC is significantly associated with recurrence and is an independent prognostic factor for survival. We also found that lncRNA‐HEIH plays a key role in G0/G1 arrest, and further demonstrated that lncRNA‐HEIH was associated with enhancer of zeste homolog 2 (EZH2) and that this association was required for the repression of EZH2 target genes. Conclusions: Together, these results indicate that lncRNA‐HEIH is an oncogenic lncRNA that promotes tumor progression and leads us to propose that lncRNAs may serve as key regulatory hubs in HCC progression. (HEPATOLOGY 2011
The aryl‐to‐vinyl nickel 1,4‐migration (1,4‐Ni migration) reaction has been reported for the first time. The generated alkenyl Ni species undergo a reductive coupling reaction with unactivated ...brominated alkanes affording a series of trisubstituted olefins. This tandem reaction exhibits mild conditions, a broad substrate scope, high regioselectivity, and excellent Z/E stereoselectivity. A series of controlled experiments have shown that the critical 1,4‐Ni migration process is reversible. In addition, the alkenyl nickel intermediates obtained after migration are highly Z/E stereoselective and do not undergo Z/E isomerization. The obtained trace isomerization products are caused by the instability of the product.
The 1,4‐nickel migration process from aryl to alkenyl groups is now reported for the first time. The alkenyl nickel intermediates generated by this highly stereoselective migration process can be coupled with brominated alkanes to form multisubstituted olefins. The current method provides a new and efficient approach for the synthesis of Z/E olefins with high stereoselectivity.
The cascade amination/cyclization of N‐arylacrylamides with alkyl amines under visible‐light photoredox catalysis is realized via intermediacy of aminium radicals. The aminium radicals are generated ...by a two‐step sequence which involves N‐chlorination of alkyl amines and subsequent reductive N−Cl cleavage. This method provides a convenient access to aminated oxindoles.
In this paper, we study gradient estimates for a parabolic p-Laplace equation with logarithmic nonlinearity, which is related to the L^p-log-Sobolev constant on Riemannian manifolds. We prove a ...global Li-Yau type gradient estimate and a Hamilton type gradient estimate for positive solutions to a parabolic p-Laplace equation with logarithmic nonlinearity on compact Riemannian manifolds with nonnegative Ricci curvature. As applications, the corresponding Harnack inequalities are derived.
Electrochemical CO
2
transformation to fuels and chemicals is an effective strategy for conversion of renewable electric energy into storable chemical energy in combination with reducing green-house ...gas emission. Metal-nitrogen-carbon (M-N-C) single atom catalysts (SAC) have shown great potential in the electrochemical CO
2
reduction reaction (CO
2
RR). However, exploring advanced SACs with simultaneously high catalytic activity and high product selectivity remains a great challenge. In this study, density functional theory (DFT) calculations are combined with machine learning (ML) for rapid and high-throughput screening of high performance CO reduction catalysts. Firstly, the electrochemical properties of 99 M-N-C SACs were calculated by DFT and used as a database. By using different machine learning models with simple features, the investigated SACs were expanded from 99 to 297. Through several effective indicators of catalyst stability, inhibition of the hydrogen evolution reaction, and CO adsorption strength, 33 SACs were finally selected. The catalytic activity and selectivity of the remaining 33 SACs were explored by micro-kinetic simulation based on Marcus theory. Among all the studied SACs, Mn-NC
2
, Pt-NC
2
, and Au-NC
2
deliver the best catalytic performance and can be used as potential catalysts for CO
2
/CO conversion to hydrocarbons with high energy density. This effective screening method using a machine learning algorithm can promote the exploration of CO
2
RR catalysts and significantly reduce the simulation cost.
Density functional theory calculations are combined with machine learning for rapid and high-throughput screening of high performance single-atom catalysts for the CO reduction reaction.
A metal‐free oxidative radical cyclization/selenylation of propargylic aryl ethers with diaryl diselenides was developed. This protocol provided an alternative method to synthesize ...3‐organoselenyl‐2H‐coumarins via the formation of C−Se bond, C−C bond, and C=O bond in one step. Moreover, a broad range of functional groups (such as halogen, aldehyde, ketone, cyano, and nitro group) were tolerated.
We here report that miR‐17‐92 cluster is a novel target for p53‐mediated transcriptional repression under hypoxia. We found the expression levels of miR‐17‐92 cluster were reduced in hypoxia‐treated ...cells containing wild‐type p53, but were unchanged in hypoxia‐treated p53‐deficient cells. The repression of miR‐17‐92 cluster under hypoxia is independent of c‐Myc. Luciferase reporter assays mapped the region responding to p53‐mediated repression to a p53‐binding site in the proximal region of the miR‐17‐92 promoter. Chromatin immunoprecipitation (ChIP), Re‐ChIP and gel retardation assays revealed that the binding sites for p53‐ and the TATA‐binding protein (TBP) overlap within the miR‐17‐92 promoter; these proteins were found to compete for binding. Finally, we show that pri‐miR‐17‐92 expression correlated well with p53 status in colorectal carcinomas. Over‐express miR‐17‐92 cluster markedly inhibits hypoxia‐induced apoptosis, whereas blocked miR‐17‐5p and miR‐20a sensitize the cells to hypoxia‐induced apoptosis. These data indicated that p53‐mediated repression of miR‐17‐92 expression likely has an important function in hypoxia‐induced apoptosis, and thus further our understanding of the tumour suppressive function of p53.
An approach for the preparation of boronated γ‐lactams via palladium‐catalyzed boryldifluoroalkylation of alkenes with α‐bromodifluoroacetamides was developed. This method exhibits good functional ...group tolerance. Various boronated products were obtained in moderate to good yields for 1 h. Mechanistic studies indicated that this reaction may involve an intramolecular radical cascade cyclization process.
In this paper, we prove the generalized displacement convexity for nonlinear mobility continuity equation with
p
-Laplacian on Wasserstein space over Riemannian manifolds under the generalized McCann ...condition GMC(
m
,
n
). Moreover, we obtain some variational formulae along the Langevin deformation of flows on the generalized Wasserstein space, which is the interpolation between the gradient flow and the geodesic flow. We also establish the connection between the displacement convexity of entropy functionals and the concavity of
p
-Rényi entropy powers. As an application, we derive the NIW formula which indicates the relationship between the
p
-Rényi entropy powers
N
b
, the Fisher information
I
b
and the
W
-entropy.
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