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The increasing demand for concrete reduces natural resources, such as sand and gravel, and also leads to a sharp increase in the amount of waste concrete produced. Due to the fact that the physical and mechanical properties of waste concrete made of recycled aggregates (RAs) differ greatly, it is difficult to use directly as a raw material for reinforced concrete (RC) components, which greatly restricts the popularization and application of RAs in actual projects. Utilizing the alkali aggregate properties of RAs to capture CO2 from industrial waste gases is an innovative way of enhancing their properties and promoting their application in real projects. However, the extent of the influence of original concrete strength (OCS) and coarse aggregate size (CAS) on the accelerated carbonation modification of RA is not clear, and a quantitative description is still required. For this purpose, accelerated carbonation tests on recycled coarse aggregate (RCA) samples under completely dry condition were carried out, and the variation laws for the physical property indicators of RCA samples before and after accelerated carbonation versus the OCS and CAS were revealed. Moreover, the influence degrees of the two factors, OCS and CAS, on the property enhancement of RCAs after accelerated carbonation were clarified, and the results of OCS and CAS corresponding to the best accelerated carbonation effects of RCAs were determined. By analyzing the micromorphology of RCA before and after accelerated carbonation, the reasons for property enhancement of RCAs with various OCSs and CASs under the best carbonation modifications were clarified. The findings will contribute to the development of basic theoretical research on accelerated carbonation modification of RA and have important scientific value. [ABSTRACT FROM AUTHOR]

The physical and mechanical properties of recycled coarse aggregate (RCA) are worse than those of natural coarse aggregate (NCA), and the overall performance of recycled concrete prepared from RCA is worse than that of natural aggregate concrete. Treatment of RCA by CO2-accelerated carbonation effectively improves the macroscopic properties of RCA. The degree of influence of raw material factors, i.e., the original concrete strength (OCS) and initial moisture content (IMC) of RCA, on the carbonation of RCAs is very complex. Herein, an accelerated carbonation experiment for RCA with different material factors as variables was carried out to explore the influence of the abovementioned factors on the physical properties of carbonated recycled coarse aggregate (CRCA). By analyzing the microstructure of the RCA with the best modification effect before and after carbonation, the carbonation modification mechanism of the RCA was revealed. The physical performance indexes, including the apparent density, water absorption and carbonation rate, of the dried RCA with an OCS of C40 and C50 were significantly improved. The research results can provide basic data and theoretical support for promoting the popularization and application of RCA and recycled concrete in practical engineering. [ABSTRACT FROM AUTHOR]

Through the salification reaction of carboxylation, successful attachment of the long-chain alkanoic acid to the two ends of 1,3-propanediamine was realized, which enabled the doubling of the long-chain alkanoic acid carbon chain. Hydrous 1,3-propanediamine dihexadecanoate (abbreviated as 3C16) and 1,3-propanediamine diheptadecanoate (abbreviated as 3C17) were synthesized afterward, and their crystal structures were characterized by the X-ray single crystal diffraction technique. By analyzing their molecular and crystal structure, their composition, spatial structure, and coordination mode were determined. Two water molecules played important roles in stabilizing the framework of both compounds. Hirshfeld surface analysis revealed the intermolecular interactions between the two molecules. The 3D energy framework map presented the intermolecular interactions more intuitively and digitally, in which dispersion energy plays a dominant role. DFT calculations were performed to analyze the frontier molecular orbitals (HOMO–LUMO). The energy difference between the HOMO–LUMO is 0.2858 eV and 0.2855 eV for 3C16 and 3C17, respectively. DOS diagrams further confirmed the distribution of the frontier molecular orbitals of 3C16 and 3C17. The charge distributions in the compounds were visualized using a molecular electrostatic potential (ESP) surface. ESP maps indicated that the electrophilic sites are localized around the oxygen atom. The crystallographic data and parameters of quantum chemical calculation in this paper will provide data and theoretical support for the development and application of such materials. [ABSTRACT FROM AUTHOR]

TiO2 electrospun nanofibers (TiO2 ENNFs) were synthesized with titanium tetraisopropoxide as precursor by an electrospinning process and characterized by SEM, TEM, XRD, XPS, FT−IR, UV and FL. For the excellent properties of film formation, Nafion/TiO2 ENNFs modified electrode was constructed, which exhibited an excellent electrochemiluminescence (ECL) performance and stability while K2S2O8 as co‐reactant. In the presence of dopamine (DA), the ECL signal quenched, which was due to that DA easily can be oxidized by holes generated by S2O82− in electrode surface, thereby inhibiting the formation of TiO2*. Based on this, a new ECL method was proposed for DA detection with a linear range from 0.033 μM to 6.7 μM. The detection limit was 0.017 μM and it was applied in the detection of DA in dopamine hydrochloride injection with satisfactory results. [ABSTRACT FROM AUTHOR]

Two‐dimensional (2D) materials have captured a tremendous amount of attention worldwide due to their unique physical and chemical properties. Herein, a mesoscopic graphdiyne (GDY) film is prepared through a facile solution method and directly used to construct an ultra‐fast visible light detector. This GDY thin film‐based photodetector exhibits both stable and repeatable high‐performance photoelectric responses to the visible light with various wavelengths. Among the visible light range, the GDY thin film is discovered to be most sensitive to 640 nm laser, which can enable it to achieve the highest response value of up to 46300%, thus conferring GDY materials an undeniable superiority of application in photoelectric devices. Especially, such GDY‐based detectors demonstrate ultra‐fast response speeds with an ephemeral response/recovery time of only 5.15/19.83 µs, which is far better than most reported photosensitive materials, including inorganic materials, low‐dimensional composites, and heterojunctions. This study suggests that GDY thin films can be regarded as new promising candidates for application as rapid photoelectric sensors. More importantly, this paper reveals the vast potential of such sp‐hybridized carbon as novel carbon‐based semiconductors in future optoelectronic applications due to their unique structure and energy band. [ABSTRACT FROM AUTHOR]

Non-coding RNAs, including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs/miRs), have significant regulatory effects on a number of biological processes in myocardial ischemia/reperfusion (I/R) injury, including cell differentiation, proliferation and apoptosis. In the present study, the expression levels of lncRNAs, miRNAs and mRNAs were evaluated in a mouse model of myocardial I/R injury. The potential functions of these differentially expressed genes were then analyzed via Gene Ontology and pathway analyses. Additionally, the interactions between lncRNA-miRNA-mRNA were predicted by constructing a competing endogenous RNA regulatory network. It was found that 14,366 lncRNAs, 151 miRNAs and 9,377 mRNAs were differentially expressed in mice hearts after I/R compared with the Sham group (fold change >2; P<0.05). The results indicated that these differentially expressed genes were involved in multiple molecular functions, including 'guanosine diphosphate binding', 'RNA polymerase II carboxy-terminal domain kinase activity', 'TATA-binding protein-class protein binding', 'nicotinamide adenine dinucleotide binding' and 'protein phosphatase type 2A regulator activity'. The interactions between lncRNA-miRNA-mRNA, including five lncRNAs, 38 miRNAs and 196 mRNAs, were predicted, specifically Gm12040-mmu-miR-125a-5p-decapping mRNA 1B, Rpl7l1-ps1-mmu-miR-124-3p-G protein-coupled receptor 146, Gm11407-mmu-miR-190a-5p-homeobox and leucine zipper encoding (HOMEZ), 1600029O15Rik-mmu-miR-132-3p-HOMEZ and AK155692-mmu-miR-1224-3p-activating transcription factor 6β. Collectively, these findings provided novel insights for future research on lncRNAs, miRNAs and mRNAs in myocardial I/R injury. [ABSTRACT FROM AUTHOR]

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