Circular RNAs are a class of regulatory RNA transcripts, which are ubiquitously expressed in eukaryotes. In the current study, we evaluate the function of a novel circRNA derived from the β-catenin ...gene locus, circβ-catenin.
Circβ-catenin is predominantly localized in the cytoplasm and displays resistance to RNase-R treatment. We find that circβ-catenin is highly expressed in liver cancer tissues when compared to adjacent normal tissues. Silencing of circβ-catenin significantly suppresses malignant phenotypes in vitro and in vivo, and knockdown of this circRNA reduces the protein level of β-catenin without affecting its mRNA level. We show that circβ-catenin affects a wide spectrum of Wnt pathway-related genes, and furthermore, circβ-catenin produces a novel 370-amino acid β-catenin isoform that uses the start codon as the linear β-catenin mRNA transcript and translation is terminated at a new stop codon created by circularization. We find that this novel isoform can stabilize full-length β-catenin by antagonizing GSK3β-induced β-catenin phosphorylation and degradation, leading to activation of the Wnt pathway.
Our findings illustrate a non-canonical function of circRNA in modulating liver cancer cell growth through the Wnt pathway, which can provide novel mechanistic insights into the underlying mechanisms of hepatocellular carcinoma.
2D covalent organic frameworks (2D COFs) have been recognized as a novel class of photoactive materials owing to their extended π‐electron conjugation and high chemical stabilities. Herein, a new ...covalent organic framework (Tph‐BDP) is facilely synthesized by using a porphyrin derivative and an organic dye BODIPY derivative (5,5‐difluoro‐2,8‐diformyl‐1,3,7,9‐tetramethyl‐10‐phenyl‐5H‐dipyrrolo1,2‐c:2′,1′‐f1,3,2diazabori‐nin‐4‐ium‐5‐uide) as monomers for the first time, and their unique photosensitive properties endow them excellent simulated oxidase activity under 635 nm laser irradiation that can catalyze the oxidation of 3,3′,5,5′‐tetramethylbenzidine (TMB). Further findings demonstrate that the presence of uranium (UO22+) can coordinate with imines of the oxidation products of TMB, thus modulating the charge transfer process of the colored products accompanied with intensive aggregation and remarkable color fading. This research provides a preparation strategy for COFs with excellent photocatalytic properties and nanozyme activity, and broadens the applications of the simple colorimetric methods for sensitive and selective radionuclide detection.
A new covalent organic framework is facilely synthesized and its unique photosensitive property endows excellent simulated oxidase activity that can catalyze the oxidation of 3,3′,5,5′‐tetramethylbenzidine (TMB). The presence of uranium can coordinate with imines of the oxidation products of TMB, thus modulating the charge transfer process of the colored products accompanied with intensive aggregation and remarkable color fading.
In order to improve the evaluation methods of English teaching efficiency, improve the accuracy and operability of evaluation, this paper analyzes the basic characteristics of English teaching ...efficiency from the perspective of ecological classroom theory, and puts forward a formula to measure the efficiency of Ecological English teaching. On this basis, this paper discusses a new method to evaluate eco-English teaching efficiency from two levels of basic characteristics and overall structure and illustrates the intuitiveness and feasibility of this method through an example to enhance its application value and reference significance. For the evaluation of effective English learning process, this paper combines the principal component analysis method and data envelopment analysis method to establish an analysis model of the relative efficiency of effective English learning, including a constant return to scale model, variable return to scale model, and scale efficiency model, which provides a quantitative analysis basis for the evaluation of effective English learning process. In order to facilitate the analysis of the relationship between “input” and “output” in English learning, and facilitate the quantitative analysis of the relationship between strategy choice and achievement in English learning, so as to provide scientific reference for English teaching and research.
Uranium is a key resource for the development of the nuclear industry, and extracting uranium from the natural seawater is one of the most promising ways to address the shortage of uranium resources. ...Herein, a semiconducting covalent organic framework (named NDA‐TN‐AO) with excellent photocatalytic and photoelectric activities was synthesized. The excellent photocatalytic effect endowed NDA‐TN‐AO with a high anti‐biofouling activity by generating biotoxic reactive oxygen species and promoting photoelectrons to reduce the adsorbed UVI to insoluble UIV, thereby increasing the uranium extraction capacity. Owing to the photoinduced effect, the adsorption capacity of NDA‐TN‐AO to uranium in seawater reaches 6.07 mg g−1, which is 1.33 times of that in dark. The NDA‐TN‐AO with enhanced adsorption capacity is a promising material for extracting uranium from the natural seawater.
Photoelectric and photocatalytic effects endow the covalent organic framework NDA‐TN‐AO with good anti‐biofouling activity. This occurs by generating biotoxic reactive oxygen species and promoting photoelectrons to reduce the adsorbed UVI to insoluble UIV, thereby improving the uranium adsorption capacity.
Using the hourly precipitation records of meteorological stations in Shanghai, covering a period of almost a century （1916-2014）, the long-term variation of extreme heavy precipitation in Shanghai on ...multiple spatial and temporal scales is analyzed, and the effects of urbanization on hourly rainstorms studied. Results show that： （1） Over the last century, extreme hourly precipitation events enhanced significantly. During the recent urbanization period from 1981 to 2014, the frequency of heavy precipitation increased significantly, with a distinct localized and abrupt characteristic. （2） The spatial distribution of long-term trends for the occurrence frequency and total precipitation intensity of hourly heavy precipitation in Shanghai shows a distinct urban rain-island feature; namely, heavy precipitation was increasingly focused in urban and suburban areas. Attribution analysis shows that urbanization in Shanghai contributed greatly to the increase in both frequency and intensity of heavy rainfall events in the city, thus leading to an increasing total precipitation amount of heavy rainfall events. In addition, the diurnal variation of rainfall intensity also shows distinctive urban-rural differences, especially during late afternoon and early nighttime in the city area. （3） Regional warming, with subsequent enhancement of water vapor content, convergence of moisture flux and atmospheric instability, provided favorable physical backgrounds for the formation of extreme precipitation. This accounts for the consistent increase in hourly heavy precipitation over the whole Shanghai area during recent times.
Electrochemiluminescence (ECL) plays a key role in analysis and sensing because of its high sensitivity and low background. Its wide applications are however limited by a lack of highly tunable ECL ...luminophores. Here we develop a scalable method to design ECL emitters of covalent organic frameworks (COFs) in aqueous medium by simultaneously restricting the donor and acceptor to the COFs' tight electron configurations and constructing high-speed charge transport networks through olefin linkages. This design allows efficient intramolecular charge transfer for strong ECL, and no exogenous poisonous co-reactants are needed. Olefin-linked donor-acceptor conjugated COFs, systematically synthesized by combining non-ECL active monomers with C
or C
symmetry, exhibit strong ECL signals, which can be boosted by increasing the chain length and conjugation of monomers. The present concept demonstrates that the highly efficient COF-based ECL luminophores can be precisely designed, providing a promising direction toward COF-based ECL phosphors.
•A chaos-based non-linear inertia weight is used to balance capacities better.•Stochastic and mainstream learning strategies are devised to enhance diversity.•An adaptive position updating strategy ...further adjusts balance.•A terminal replacement mechanism is adopted to enhance convergence precise.
In expert systems, complex optimization problems are usually nonlinear, nonconvex, multimodal and discontinuous. As an efficient and simple optimization algorithm, particle swarm optimization(PSO) has been widely applied to solve various real optimization problems in expert systems. However, avoiding premature convergence and balancing the global exploration and local exploitation capabilities of the PSO remains an open issue. To overcome these drawbacks and strengthen the ability of PSO in solving complex optimization problems, a modified PSO using adaptive strategy called MPSO is proposed. In MPSO, in order to well balance the global exploration and local exploitation capabilities of the PSO, a chaos-based non-linear inertia weight is proposed. Meanwhile, to avoid the premature convergence, stochastic and mainstream learning strategies are adopted. Finally, an adaptive position updating strategy and terminal replacement mechanism are employed to enhance PSO’s ability to solve complex optimization problems in expert systems. 30 complex CEC2017 benchmark functions are utilized to verify the promising performance of MPSO, experimental results and statistical analysis indicate that MPSO has competitive performance compared with 16 state-of-the-art algorithms. The source code of MPSO is provided at https://github.com/lhustl/MPSO .
The planthopper superfamily Fulgoroidea (Insecta: Hemiptera) is one of the most dominant groups of phytophagous insects. It comprises about 20 families, containing a total of 9000 species worldwide. ...Despite several recent studies, the phylogeny of Fulgoroidea is not yet satisfactorily resolved and the phylogenetic positions of several key families, especially Cixiidae, Delphacidae, Tettigometridae, Nogodinidae, Acanaloniidae and Issidae, are contentious. Here, we expand upon recent phylogenetic work using additional nuclear (18S and 28S) and novel mitochondrial (16S and cytb) markers. Maximum likelihood and Bayesian analyses yielded robust phylogenetic trees. In these topologies, a group containing Cixiidae and Delphacidae is recovered as the sister group to the remaining taxa. Tettigometridae is placed in a more nested position and is grouped with Caliscelidae. Sister relationships are found between Flatidae and Ricaniidae, and between Dictyopharidae and Fulgoridae. Nogodinidae and Issidae are confirmed to be non-monophyletic families. For major nodes of interest, divergence date estimates are generally older than those from the fossil record.
In this work, a novel P/N-containing oligomer poly(piperazine phenylphosphamide) (BPOPA) was synthesized via the polymerization reaction of phenylphosphonic dichloride with piperazine. Its structure ...was characterized by Fourier transformation infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), elemental analysis (EA) and gel permeation chromatography (GPC). It was used to enhance the flame retardancy of epoxy resin/ammonium polyphosphate (APP). As expected, improvement in flame retardancy of EP/APP was observed. In detail, EP containing 10 wt% APP alone possessed a LOI value of 30.2% but UL-94 no rating. When both 7.5 wt% APP and 2.5 wt% BPOPA were added into EP, EP/7.5APP/2.5BPOPA passed a UL-94 V-0 rating with a LOI value of 33.1%. Moreover, EP/7.5APP/2.5BPOPA presented much lower values of the peak of heat release rate (PHRR) and total smoke production (TSP) compared with EP/10APP. The flame-retardant mechanism was analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis/infrared spectrometry (TG-IR). Results illustrated that EP/7.5APP/2.5BPOPA mainly functioned in condensed phase which was associated with the formation of more compact char layer.
•A novel P/N-containing oligomer (BPOPA) was synthesized and characterized successfully.•Adding BPOPA significantly improved flame retardancy of EP/APP.•Incorporation of BPOPA improved compactness degree of char for EP/APP during combustion.
As a major noncoding fragment, the control region (CR) of mtDNA is responsible for the initiation of mitogenome transcription and replication. Several structural features of CR sequences have been ...reported in many insects. However, comprehensive analyses on the structural organization and phylogenetic utility, as well as the role of tandem replications (TRs) on length variation, high A+T content, and shift of base skew of CR sequences are poorly investigated in hemipteran insects. In this study, we conducted a series of comparative analyses, using 116 samples covering all 11 infraorders of the five currently recognized monophyletic groups in the Hemiptera. Several structural elements (mononucleotide stretches containing conserved sequence blocks (CSBs), TRs, and GA-rich region) were identified in the mitochondrial control region in hemipteran insects, without showing a consistent location. The presence and absence of certain specific structural elements in CR sequences show the various structural organizations of that segment among the five monophyletic groups, which indicates the diversification of the control region's structural organization in Hemiptera. Among the many groups within Hemiptera, eight monophyletic groups and three consistent phylogenetic trees were recovered, using CSBs datasets by maximum likelihood and Bayesian methods, which suggests the possible utility of CR sequences for phylogenetic reconstruction in certain groups of Hemiptera. Statistical analyses showed that TRs may contribute to the length variation, high AT content, and the shift of base skewing of CR sequences toward high AT content in the Hemiptera. Our findings enrich the knowledge of structural organization, phylogenetic utility, and roles of tandem replication of hemipteran CR, and provide a possible framework for mitochondrial control region analyses in hemimetabolous insects.
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