Multidimensional (MD) analysis contributes to a comprehensive linguistic description of second language (L2) writing texts. However, cross-linguistic studies based on MD analysis are still ...insufficient and need to be increased. In particular, the unavailability of comparable corpora prevents current MD-based L2 writing research from making reliable comparisons of linguistic differences between native writers and L2 learners. Considering these, this study adopts corpora of maximum similarity for the cross-linguistic comparative analysis. Using Biber’s MD analysis, this study compares linguistic differences between native English writers and Chinese English learners in argumentative essays with similar communicative purposes. The analysis reveals that the two groups of texts show significant differences in slightly over half of the individual linguistic features but share more similarities than differences in textual dimensions. It also shows that the two groups are, in fact, different varieties of English language use, even though they share a similar text type of “involved persuasion.” The results confirm the importance of comparable corpora for cross-linguistic comparisons and the necessity of MD analysis for understanding L2 writing.
A versatile manganese(I) catalyst was employed in CH aminocarbonylation reactions of heteroarenes with aryl as well as with alkyl isocyanates using a removable directing group approach. Detailed ...experimental mechanistic studies were suggestive of an organometallic CH manganesation step, followed by a rate‐determining migratory insertion.
Heteroaromatic amides were obtained by a step‐economical, manganese(I)‐catalyzed CH aminocarbonylation reaction between heteroarenes and aryl and alkyl isocyanates. The catalytic cycle was initiated by a facile organometallic CH manganesation step, followed by a rate‐determining migratory insertion. DG = directing group.
Calcium oxide is one of the most promising heterogeneous catalysts for biodiesel production. However, an inherent drawback of CaO is the leaching of active species into the reaction solution with the ...degraded reusability. To strengthen the stability, different supports are composited with the SrO–CaO oxide through the hydrothermal method and mass ratio of SrO to CaO are optimized to get the best outcome of the catalyst. Meanwhile, various characterization methods, including TG, XRD, SEM-EDX, CO2-TPD, XPS, ATR-FTIR and ICP-AES, are used to explore the physicochemical properties of catalysts. The 0.4-SrO-CaO-Al2O3 catalyst shows the best catalytic capability in transesterification of palm oil with methanol to produce biodiesel, where the FAME yield of 98.16% is achieved with the molar ratio of methanol to oil of 18:1 and catalyst concentration of 7.5 wt% at 65 °C for 3 h. Besides, ascribed to the greatly reduced leaching out of the active species, this catalyst presents the satisfying reusability and the FAME yield is slightly decreased to 92.61% for the fifth reused cycle. Therefore, this modification method for SrO–CaO–Al2O3 is feasible for enhancing the catalytic stability in transesterification.
•SrO–CaO–Al2O3 trimetallic oxide catalyst is reported for the first time.•0.4-SrO-CaO/Al2O3 shows excellent catalytic activity in transesterification.•Calcium leaching is greatly reduced and catalyst shows strong catalytic stability.•Main physicochemical properties of produced biodiesel meet the limit of ASTM D6751.
BACKGROUND As all we know, gastric cancer (GC) is a highly aggressive disease. Recently, circular RNA (circRNA) was found to play a vital role in regulation of GC. Some circRNAs could regulate ...messenger RNA (mRNA) expression by functioning as a microRNA (miRNA) sponge. Nevertheless, the circRNA-miRNA-mRNA regulatory network involved GC rarely has been explored and researched. MATERIAL AND METHODS All the differentially expressed circRNAs, miRNAs, and mRNA were derived from Gene Expression Omnibus (GEO) microarray data (GSE78092, GSE89143, GSE93415, and GSE54129). GC level 3 miRNA-sequencing data and clinical information were downloaded from The Cancer Genome Atlas (TCGA) database. Furthermore, a circRNA-miRNA-mRNA regulatory network was constructed by Cytoscape (version 3.6.1). Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway revealed the functions and signaling pathways associated with these target genes. Hub genes of protein-protein interaction (PPI) network were identified by STRING database and cytoHubba. RESULTS The regulatory network consists of 3 circRNAs, 22 miRNAs, and 128 mRNAs. Only 3 miRNAs of the network were consistent with the expression of TCGA and were associated with some clinical features. The results of the functional analysis of 128 mRNAs showed that GO analysis and KEGG pathways of inclusion criteria were 49 and 24, respectively. PPI network and Cytoscape showed that the top 10 hub genes were MYC, CTGF, TGFBR2, TGFBR1, SERPINE1, KRAS, ZEB1, THBS1, CDK6, and TNS1; 4 of which were verified by GEPIA based on TCGA. Highly expressed SERPINE1 had a poor OS (over survival) and DFS (disease-free survival), and TGFBR1 expression increased along with the increase of clinical stages. CONCLUSIONS This study looked at a circRNA-miRNA-mRNA regulatory network associated with GC and explored the potential functions of mRNA in the network, then identified a new molecular marker for prediction, prognosis, and therapeutic targets for clinical patients.
Nanozymes are artificial enzymes, which can substitute traditional biological enzymes for multifield applications. However, to date, it remains challenging to search novel mimic enzymes or ...multienzyme mimics. Herein, a facile and green method for preparing monodisperse, homogeneous copper nanoclusters (Cu NCs) with smaller size was developed, which used cysteamine as a template and hydrazine hydrate as a reductant to reduce Cu2+. The as-prepared Cu NCs exhibited excellent tetraenzyme-like activities, including peroxidase (POD)-, catalase (CAT)-, superoxide dismutase (SOD)-, and ascorbic acid oxidase (AAO)-mimic activities. The mechanisms, kinetics, and catalytic performances of Cu NCs were systematically studied. Moreover, based on the POD-like activity of Cu NCs, sensitive and simple colorimetric sensing glutathione (GSH) was explored, with the low limit of detection of 0.89 μM GSH (S/N = 3). Additionally, a novel fluorimetric ascorbic acid (AA) sensor was developed with the linear range of 0.5–30 μM and limit of detection (LOD) of 0.144 μM, on the basis of the principle that AA is oxidized to dehydroascorbic acid (DHAA) specifically catalyzed by the AAO-like activity of Cu NCs, while DHAA can further react with o-phenylenediamine (OPDA) to generate a highly fluorescent quinoxaline (DFQ) derivative. The as-proposed colorimetric GSH sensor and the fluorimetric AA sensor were capable of detecting GSH and AA, respectively, in real samples accurately and reproducibly. Thus, the Cu NCs-based multienzyme mimic is a promising candidate for biocatalysis and biosensing.
Mobile-assisted language learning (MALL) creates more opportunities for learners to access learning resources more easily and selfdirectly without time and place limitation. Thus, this study aimed at ...developing MALL materials to support the English oral communicative learning of Thai airport immigration police officers based on needs analysis and exploring the quality of MALL materials to support English oral communicative learning of Thai Airport Immigration police officers.The instruments of this study were the semi-structured interviews with the officers in order to conduct needs analysis, and the IOC (Item-Objective Congruence) form for experts to validate the materials developed, and the questionnaire to assess the officers’ opinions after using the materials to explore the quality. ADDIE model was applied to guide the overall process of developing the materials. The findings indicated that the self-instructional MALL materials laded in WeChat public platform that consisted of two units, Arrival and Departure, and ten lessons that were under each unit, both of which were accordance with the airport immigration officers’ needs. Moreover, the evaluation based on the officers’ opinions revealed that the MALL materials had high quality of content, rational organization, pleasant presentation and convenient functions of the platform.
The first manganese(I)‐catalyzed C−H allylations with ample scope were achieved by carboxylate assistance. The highly selective C−H/C−O functionalizations proved viable with densely substituted allyl ...carbonates, and the organometallic C−H allylation strategy set the stage for expedient late‐stage diversification with excellent levels of positional selectivity.
Manganese(I) carboxylate catalysts allow step‐economical C−H allylations with broad substrate scope. The reaction proceeds through redox‐neutral organometallic C(sp2)−H activation, which has the advantage of enabling the transformative late‐stage diversification of functionalized molecules.
Mounting evidence has demonstrated that a lot of miRNAs are overexpressed or downregulated in colorectal cancer (CRC) tissues and play a crucial role in tumorigenesis, invasion, and migration. The ...aim of our study was to screen new biomarkers related to CRC prognosis by bioinformatics analysis. By using the R language edgeR package for the differential analysis and standardization of miRNA expression profiles from The Cancer Genome Atlas (TCGA), 502 differentially expressed miRNAs (343 up-regulated, 159 down-regulated) were screened based on the cut-off criteria of
< 0.05 and |log2FC|>1, then all the patients (421) with differentially expressed miRNAs and complete survival time, status were then randomly divided into train group (212) and the test group (209). Eight miRNAs with
< 0.005 were revealed in univariate cox regression analysis of train group, then stepwise multivariate cox regression was applied for constituting a five-miRNA (hsa-miR-5091, hsa-miR-10b-3p, hsa-miR-9-5p, hsa-miR-187-3p, hsa-miR-32-5p) signature prognostic biomarkers with obviously different overall survival. Test group and entire group shown the same results utilizing the same prescient miRNA signature. The area under curve (AUC) of receiver operating characteristic (ROC) curve for predicting 5 years survival in train group, test group, and whole cohort were 0.79, 0.679, and 0.744, respectively, which demonstrated better predictive power of prognostic model. Furthermore, Univariate cox regression and multivariate cox regression considering other clinical factors displayed that the five-miRNA signature could serve as an independent prognostic factor. In order to predict the potential biological functions of five-miRNA signature, target genes of these five miRNAs were analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway and Gene Ontology (GO) enrichment analysis. The top 10 hub genes (ESR1, ADCY9, MEF2C, NRXN1, ADCY5, FGF2, KITLG, GATA1, GRIA1, KAT2B) of target genes in protein protein interaction (PPI) network were screened by string database and Cytoscape 3.6.1 (plug-in cytoHubba). In addition, 19 of target genes were associated with survival prognosis. Taken together, the current study showed the model of five-miRNA signature could efficiently function as a novel and independent prognosis biomarker and therapeutic target for CRC patients.
Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread around the world at an unprecedented rate. In the present study, 4 marine ...sulfated polysaccharides were screened for their inhibitory activity against SARS-CoV-2, including sea cucumber sulfated polysaccharide (SCSP), fucoidan from brown algae, iota-carrageenan from red algae, and chondroitin sulfate C from sharks (CS). Of them, SCSP, fucoidan, and carrageenan showed significant antiviral activities at concentrations of 3.90-500 μg mL
−1
. SCSP exhibited the strongest inhibitory activity with IC
50
of 9.10 μg mL
−1
. Furthermore, a test using pseudotype virus with S glycoprotein confirmed that SCSP could bind to the S glycoprotein to prevent SARS-CoV-2 host cell entry. The three antiviral polysaccharides could be employed to treat and prevent COVID-19.
Sulfated polysaccharide from sea cucumber (SCSP), fucoidan from brown algae, and iota-carrageenan from red algae show inhibitory activities against SARS-CoV-2.
Zeolite 4A was successfully prepared by hydrothermal synthesis using low-grade kaolin as a raw material. The properties of the synthesized zeolite 4A were characterized by means of X-ray diffraction ...(XRD), Fourier transform infrared (FTIR),
Si magic-angle spinning (MAS)-nuclear magnetic resonance (NMR) and
Al MAS-NMR, X-ray fluorescence (XRF), scanning electron microscopy (SEM)-energy-dispersive spectrometry (EDS), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), thermogravimetry (TG)-differential thermal analysis (DTA), and carbon dioxide adsorption analysis. The textural properties of the synthesized zeolite 4A was further studied by BET analysis technique. The thermal stability analysis showed that the heat resistance of the synthesized zeolite 4A is up to 940 °C. In addition, it is found that the Langmuir model has the best agreement with the adsorption equilibrium data for carbon dioxide by synthesized zeolite 4A and commercial zeolite 4A. Meanwhile, the carbon dioxide adsorption analysis confirmed that the maximum equilibrium adsorption amount of carbon dioxide on synthesized zeolite 4A is 59.3820 mL/g, which is higher than the 55.4303 mL/g of the commercial zeolite 4A.
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