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Abstract Profound progress has been made in bio-rejuvenators to enhance aged asphalt's low temperature performance and reduce its high temperature viscosity. However, limitation still exists in the knowledge how long service life of rejuvenated asphalt is and whether regeneration is effective since aging behavior of rejuvenated asphalt is neglected. Furthermore, aging evaluation is based on different tests dependent on temperature, which may lead to various results. This study aims to evaluate the aging behavior of bio-rejuvenated Pen70 and SBS modified asphalts using internal aging indexes that characterize the physical property. Original Pen70 and SBS asphalts under identical aging conditions were set as the control group. Fourier transform infrared spectroscopy test (FTIR) was conducted to quantify aging extent through oxidation aging functional groups. Activation energy was achieved through rotational viscometer (RV). Dynamic shear modulus was acquired through dynamic shear rheological test (DSR) and characterized by two springs, two parabolic elements, and one dashpot (2S2P1D) model. For both Pen70 and SBS, the two potential aging indexes related with activation energy and viscosity of dashpot separately were found linearly correlated with related chemical aging functional groups. Through comparison, it indicates that bio-rejuvenation was a process of physical blending. It couldn't restore the crosslinking structures of SBS polymers. Besides, the physical property of bio-rejuvenated Pen70 degenerated faster, while that of bio-rejuvenated SBS stayed stable. A benefit period was proposed for the rejuvenation of Pen70 while the rejuvenation of SBS was not bound by time. Further work is needed to validate findings in the present study. Graphical abstract Image 10385 [ABSTRACT FROM AUTHOR]

A heterogeneous medium-Mn steel with ultra-high ductility and good strength was designed, which displayed yield strength of 752 MPa, ultimate tensile strength of 1068 MPa, total elongation of 72.4%, and strength-elongation product of 77.3 GPa·%. A unique pre-existing austenite + martensite lamella structure was introduced by warm rolling followed by cold rolling. During annealing, it transformed into a heterogeneous duplex-phase (ferrite and austenite) microstructure with multiple morphologies (lath-like, granular, and block) and a dispersed grain size distribution. The relationships between the microstructural evolution and Mn segregation, deformation mechanisms, and mechanical behavior were characterized. The heterogeneous austenite structure yielded different austenite-stability gradients, which triggered multi-stage transformation-induced plasticity (TRIP) effects during the tensile test, accompanied by the twinning-induced plasticity (TWIP) and microband-induced plasticity (MBIP) effects. Therefore, the synergy of multiple strengthening mechanisms significantly improved the steel ductility without affecting its strength, resulting in better mechanical properties than other medium-Mn steels. • The formation and deformation mechanism of heterogeneous microstructure were investigated in Medium Mn steel. • Mn-lean martensite bands transformed to small granular/lath-like austenite grains and Mn-rich austenite bands transformed to large block austenite grains. • The multiple deformation mechanisms including TRIP effect, TWIP effect and MBIP effect were triggered during deformation. • The product of tensile strength and total elongation of hetero-structured medium Mn steel was up to 77.3 GPa%. [ABSTRACT FROM AUTHOR]

A novel concept of microstructure design involving warm rolling and low-temperature annealing has been proposed to greatly improve the strength-ductility combination of medium Mn steel. The unique transformation induced plasticity has been triggered by firstly microbands and secondly deformation twins, enhancing the ductility significantly and the reasonable dislocation density in non-recrystallized austenite grains increases the yield strength greatly. The individual contribution of solid solution strengthening, grain boundary strengthening, V-precipitates strengthening and dislocation strengthening to yield strength is discussed by constitutive models, in which the tangled dislocation plays a dominant role. Best strength-ductility combination with yield strength (1239MPa), ultimate tensile strength (1341MPa), total elongation (41.8%) and product of strength and elongation (56.1GPa·%) has been obtained, which are comparable and superior to the reported medium-Mn steels. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: LaMnO3+δ and La0.7Ca0.3MnO3 were synthesized from La2O3(La(OH)3), CaCO3 and MnO2 powder mixture with solid-state reaction technique. X-ray diffraction and thermal analysis were employed in the present study on the process of synthesizing of the two compound powders. The kinetic study on solid-state reaction between La2O3 and MnO2 in the powder mixture was isothermally carried out for LaMnO3+δ formation. The result showed that the reaction process was controlled by three-dimensional solid-ionic diffusion. Both Jander and Ginstling-Brounstein model can be used to describe the reaction kinetics satisfactorily. The relevant apparent activation energy values obtained were as great as 205±11 and 189±8kJ/mol. The reaction process of La0.7Ca0.3MnO3 preparation from La2O3, SrCO3 and MnO2 powder mixture was also studied using X-ray diffraction and thermal analysis. The result indicated that the following steps composed the overall reaction: the decomposition of the reactant; the formation of La1−x Ca x MnO3+δ ; La2O3 and Mn3O4 reacted with La1−x Ca x MnO3 to form final La0.7Ca0.3MnO3 phase. The latest step was the most time-consuming one among others in the overall reaction. [Copyright &y& Elsevier]

Abstract: The high-temperature behavior of O-orthorhombic LaMn0.95O3.02 in air was studied by using high-temperature XRD combined with TG/DSC analysis. A phase transition from O-orthorhombic to rhombohedral was found between 573 and 773K. TG/DSC curves showed a weight gain and no DSC peaks within the temperature range of the phase transition. The phase transition is attributed to the change of oxygen content in LaMn0.95O3.02. The lattice thermal expansion coefficients of rhombohedral LaMn0.95O3.02 were calculated using lattice parameters. [Copyright &y& Elsevier]

Abstract: La1−x Sr x Co1−y Ga y O3−δ (x =0.3 and 0.5, y =0.1) were synthesized using solid-state reaction technique, and the phases formed during synthesis processes were investigated by powder XRD measurements. LaSrGa3O7 and the rhombohedral phase coexisted at 1473 K for the system with a molar ratio of La/Sr/Co/Ga equal to 0.7/0.3/0.9/0.1. For the system with molar ratio of La/Sr/Co/Ga equal to 0.7/0.3/0.7/0.3, LaSrGa3O7 and the rhombohedral phase coexisted at 1673 K, while LaSrGaO4 and the rhombohedral phase coexisted at 1873 K. Crystal structural parameters of La0.7Sr0.3Co0.9Ga0.1O3−δ and La0.5Sr0.5Co0.9Ga0.1O3−δ were obtained through a route of Rietveld refinement performed using X-ray powder diffraction data, the results showed that they are rhombohedral distorted perovskite with R3¯c symmetry. [Copyright &y& Elsevier]

• Four different layers were found in the asphalt phase of SFP through microscale tests. • A micromechanical model considering interlocking and stiffening effect was proposed for SFP. • The equivalent modulus of asphalt phase considering interlocking effect was cross-checked with NI test. Semi-flexible pavement (SFP) has been promoted to apply in pavement engineering mainly for its excellent performance in rutting resistance. However, due to the material characteristics of three-phase heterogeneous phase and the structural characteristics of dense skeleton interlocking structure, the microstructure of semi-flexible pavement material is complicated, greatly influencing the mechanical properties of the material. This research aims to identify the two characteristics of SFP employing micromechanical models as well as nano-techniques, including nanoindentation (NI), Scanning Electron Microscope (SEM) and energy dispersive spectrum analysis (EDS). Two interlocking factors were introduced in the three-phase micromechanical model to characterize the interlocking effect. Identification of the asphalt mastic phase in SFP was implemented as the basis of stiffening correction in the micromechanical model. Because four different layers were found in the asphalt phase of SFP that was difficult to simulate, a general stiffening correction was used in the improved micromechanical model. The final model considering the interlocking and asphalt stiffening effects can characterize the property of SFP well. It was found that grouting cement has an enhancement function on the viscoelastic interlocking effect while does little on the elastic interlocking effect. Meanwhile, more grouting cement will lead to more asphalt-cement stiffening effect. An equivalent dynamic modulus of the asphalt phase-phase from the micromechanical model was proposed in the end, which has been proven corresponding to the experimental results of NI test. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The 2S2P1D model is suitable for SFP. • A larger porosity in PA means a greater effect of skeleton interlock on loss modulus. • Grouting cement had a negative effect on the loss modulus at low temperatures. • Physiochemical stiffening effect and imperfect interface exist between PA and cement skeletons. • A larger porosity leads to a more stable interlock effect with the frequency increasing. Abstract Semi-flexible pavement (SFP) has been promoted to apply in pavement engineering mainly for its excellent performance in rutting resistance. Since the reinforcing mechanism of its stiffness and strength is still ambiguous, this paper aims to investigate the reinforcing mechanisms of SFP at meso-scale. SFP was regarded as a double skeleton structure (open graded asphalt skeleton and grouting cement skeleton) and three main reinforcing mechanisms were characterized on the basis of the Mori-Tanaka model (M-T), including matrix modulus, cement filling effect and double structure interlock. During the process, the matrix of SFP was redefined as asphalt mixture without effect of cement-filling air voids. The behavior of the imaginary matrix was obtained through back-calculation in M-T model. The two springs, two parabolic elements, and one dashpot (2S2P1D) model was utilized to characterize viscoelastic behavior and two interlock factors were established to amend interlock effect. The results may demonstrate the existence of physiochemical stiffening effect of grouting cement and imperfect interphase between the two skeletons. SFP with matrix of three different original porosities were compared during the prediction process. It was found that the reinforcing rate was positively related with original porosity. While the dynamic modulus value of SFP, meaning specially storage modulus value, depended more on the matrix gradation than porosity. And grouting cement had a negative effect on the holistic loss modulus at high frequencies. [ABSTRACT FROM AUTHOR]

Abstract: The effect of oxygen partial pressure () on the electrical conductivity of La2Mo2− x W x O9−δ (x = 0.0, 0.5, 0.7) was investigated from 873 to 1073 K using AC impedance spectroscopy in oxygen, air, argon, and CO–CO2 mixtures with CO volume percentages, 0.5%, 9%, 33% and 50% used for producing lower oxygen partial pressures. The results have shown that the electrical conductivity increases slowly with the decreasing when the CO content is not greater than 0.5 vol.%. has more significant influence on the electrical conductivity of W-doped La2Mo2O9 than on that of undoped La2Mo2O9. For La2Mo1.3W0.7O9, the logσ attained in all atmospheres except oxygen and CO–CO2 mixture with 50 vol.% CO, exhibits a good linear relationship with log . The corresponding slopes attained are as large as 0.019–0.021, much lower than 1/4, suggesting that the enhancement of total electrical conductivity could be mainly due to the increase of ionic conductivity when decreases. XRD and XPS analyses for La2Mo2−x W x O9−δ have confirmed that a small amount of Mo6+ has been reduced to Mo4+ during the electrical conductivity measurements in CO–CO2 mixture with 9 vol.% CO, and further decreasing causes the formation of La7Mo7O30. This may lead to the remarkable changes in their electrical conductivities. A critical value for each compound at a specified temperature between 873 and 1073 K has been found, and below this value the compound would become unstable. The critical values attained at 973 K are as follows: 10−12, 10−15 and 10−17 Pa for La2Mo2O9, La2Mo1.5W0.5O9 and La2Mo1.3W0.7O9 respectively. [Copyright &y& Elsevier]

Abstract: La2−x Ba x Mo2O9−x/2 (x ≤0.18) have been prepared by solid state reaction method. The lattice parameter of La2−x Ba x Mo2O9−x/2 (x ≤0.18) determined by XRD data refinement shows a linear dependence on the dopant Ba content x. For the specimen with a La/Ba molar ratio of 0.18–0.2, additional reflection of secondary phase exists in the XRD pattern, so the value of solubility limit for Ba in La2Mo2O9 is defined in range of 0.18< x <0.2. As the replacement degree of La3+ by Ba2+ increases, the bulk conductivity of La2−x Ba x Mo2O9−x/2 (x ≤0.18) decreases initially and then increases, a minimum value at La1.9Ba0.1Mo2O8.95 exists. Hebb–Wagner studies in argon atmosphere, which use an oxide-ion blocking electrode, show that La2−x Ba x Mo2O9−x/2 (x ≤0.18) are predominantly oxide-ion conducting in the temperature ranging from 773 to 1173K. The average thermal expansion coefficient of La1.84Ba0.16Mo2O8.92 determined by high-temperature XRD was deduced as great as 17.5×10−6 K−1 between 298 and 1173K. [Copyright &y& Elsevier]

Hexagonal CePO4 nanowires with a high aspect ratio were controllably synthesized through an oxalate-induced hydrothermal route. The hexagonal CePO4 and CePO4:Tb nanowires exhibited highly enhanced photoluminescence. The organic ligand oxalate was found to play a role for the oriented growth of the nanowires, as well as the structure evolution. The synthesis of nanostructured CePO4 with hexagonal and monoclinic structures was controlled by varying the molar ratios. A formation mechanism of the morphology and crystal structure was proposed. [Copyright &y& Elsevier]

• The heterogeneity and interlocking effect were evaluated in SFP's stiffness and strength. • Strain related strength theory should be used for SFP in engineering. • The addition of fiber can restrain the trend of accelerated shear failure along interface. Semi-flexible pavement (SFP) material has been promoted to apply in pavement engineering mainly for its excellent performance in rutting resistance. But its mechanical behavior is complicated due to its heterogeneity and interlocking structure. According to the present study, the damage process of SFP (with and without fiber), as well as its porous asphalt (PA) matrix, under uniaxial compression test was detected employing acoustic emission (AE) technique. The heterogeneity and the interlocking effect were varied by changing the matrix porosity and the gradation, respectively. The stress-strain curves reveal that cement grouting could decrease the material's failure strain distinctly, while the addition of fiber made no effect on the results. Nevertheless, both the cement grouting and the addition of fiber caused medium and high amplitude (50–65 dB) AE signals during the AE detection. Besides, the Rise Angle (RA) value and energy distribution both illustrate that there was increasing trend in the amounts of shear cracking in SFP during compression, which was different from asphalt mixtures. And the addition of fiber could restrain the shear cracking to improve the crack resistance. Quantificationally, heterogeneity was characterized by standard deviation of compositions' modulus and an interlocking index was extracted from a modulus micromechanical model to characterize the interlocking effect. The Weibull distribution was adopted to characterize the damage evolution, where the cumulative AE energy was chosen as the damage variable. The result shows the two Weibull parameters m , n had obviously positive correlation with the matrix porosity and the interlocking index, respectively. [ABSTRACT FROM AUTHOR]

Abstract MicroRNA-520d-3p (miR-520d-3p) is a novel cancer-related miRNA and functions as a tumor suppressor in human cancers. However, the expression patterns and mechanisms of miR-520d-3p involved in hepatocellular carcinoma (HCC) remain rarely known. Here, we found that the expression levels of miR-520d-3p in HCC tissues and cells were significantly lower than in tumor-adjacent tissues and L02 cells. Decreased level of miR-520d-3p was relevant to poor overall survival, whereas miR-520d-3p up-regulation resulted in a marked inhibition of cell growth, migration and invasion. In addition, the long non-coding RNA, myocardial infarction associated transcript (MIAT) was up-regulated in both HCC tissues and cell lines. MIAT suppressed the expression and function of miR-520d-3p. Moreover, erythropoietin-producing hepatocellular A2 (EPHA2) was speculated and confirmed as a direct target of miR-520d-3p. We also demonstrated that MIAT may function as a sponge competitive endogenous RNA for miR-520d-3p, and thus regulate the molecular expression of EPHA2. In summary, our study has identified a novel signaling pathway through which miR-520d-3p exerts its anticarcinogenic roles and suggested that the MIAT/miR-520d-3p/EPHA2 may be a new target for HCC therapy. [ABSTRACT FROM AUTHOR]

The gas-phase selective oxidation of ethanol to acetaldehyde is a promising alternative to current Wacker process in which ethylene is catalyzed to acetaldehyde by palladium and copper chlorides in strong acidic solutions. The supported gold catalyst has been reported and showed excellent catalytic performance in gas-phase oxidation of ethanol. But its high price stimulates the studies to focus on non-noble-metal catalysts, or non-metal catalysts. Here, we report that nitrogen-doped carbon nanotubes as a bifunctional catalyst exhibits robust performance in the selective oxidation of ethanol to acetaldehyde. A stable catalytic performance with ethanol conversion of 72% and acetaldehyde selectivity of 90% at 270 °C was obtained. The substantial enhancement of acetaldehyde yield was ascribed to the synergistic effect of synchronously promoting the dissociative adsorption of O 2 and ethanol adsorption when incorporating graphite-like and pyridine-like nitrogen species. The kinetic analysis indicates that the introduction of nitrogen species can significantly decrease the activation energy of the reaction. The study of this bifunctional carbocatalyst may also provide guidance for the design of new carbon-based catalytic systems for the selective oxidation of alcohols via regulating the adsorption and activation ability of catalyst to reactants. [ABSTRACT FROM AUTHOR]

• The impact of mucoid phenotype for A. baumannii was evaluated. • The mucoid A. baumannii isolates were more hypervirulent than nonmucoid strains. • The prevalence of multi-resistant A. baumannii strains in Anhui may be ST2 clone. • No biofilm formation ability was observed for mucoid A. baumannii. • Several genes were associated with virulence regulation of mucoid A. baumannii. Mucoid phenotype is an important adaptive defense response for Acinetobacter baumannii (A. baumannii). The aim of this study was to analyze the impact of mucoid phenotype for the molecular characteristics and virulence of A. baumannii. We observed that the colonies of mucoid A. baumannii were moist, with an elevated surface, and the wire drawing result was positive. Transmission electron microscopy data showed that the outer wall of the mucoid colonies was not smooth, had protruding pseudopodia, and was surrounded by a layer of unknown material. Antibiotic susceptibility testing showed that the mucoid strains were multidrug resistant. Notably, the mucoid phenotype and antibiotic resistance were not correlated with the amount of biofilm produced by A. baumannii. MLST data demonstrated that the mucoid A. baumannii strains belonged to type ST2. Most (82.6 %, 38/46) of the multidrug-resistant nonmucoid strains also belonged to the molecular type ST2 and to other types, including ST129, ST158, ST195, ST80 and ST3. Moreover, mucoid A. baumannii strains were more virulent than nonmucoid isolates in a mouse model. The comparative transcriptomic data indicated that 15 genes, especially IX87_RS16955 (acnA), IX87_RS10800 (XanP), IX87_RS12875 (GlmM), IX87_RS00885 and IX87_RS12395 (bfr), were possibly associated with the phenotype and virulence of mucoid A. baumannii. In conclusions, the study comprehensively describes the molecular characteristics and virulence regulatory mechanism of mucoid A. baumannii, and provides novel insights for the prevention and treatment of infections associated with these strains. [ABSTRACT FROM AUTHOR]

The widespread nature of several viruses is greatly credited to their rapidly altering RNA genomes that enable the infection to persist despite challenges presented by host cells. Within the RNA genome of infections is RNA-dependent RNA polymerase (RdRp), which is an essential enzyme that helps in RNA synthesis by catalysing the RNA template-dependent development of phosphodiester bonds. Therefore, RdRp is an important therapeutic target in RNA virus-caused diseases, including SARS-CoV-2. In this review, we describe the promising RdRp inhibitors that have been launched or are currently in clinical studies for the treatment of RNA virus infections. Structurally, nucleoside inhibitors (NIs) bind to the RdRp protein at the enzyme active site, and nonnucleoside inhibitors (NNIs) bind to the RdRp protein at allosteric sites. By reviewing these inhibitors, more precise guidelines for the development of more promising anti-RNA virus drugs should be set, and due to the current health emergency, they will eventually be used for COVID-19 treatment. Image 1 • This article provides an overview of RdRp inhibitors that have been launched or are in clinical studies for the treatment of RNA virus infections, including COVID-19. • Nucleoside inhibitors (NIs) exhibit broad-spectrum antiviral activity but pose a more serious toxicity risk than non-nucleoside inhibitors (NNIs) because high dosages of NIs result in accumulation in plasma. • Structurally diverse NNIs are endowed with high potential activities but tend to induce drug resistance due to the RdRp allosteric site. [ABSTRACT FROM AUTHOR]

• Effective coarse aggregate-grouting cement contacts were distinguished from non-effective ones. • A fast contact calculation method was proposed. • A good linear relationship was found between the mechanical and morphological interlocking indexes. Semi-flexible pavement (SFP) material has been proven to have more interlocking effect than its Porous Asphalt (PA) matrix because of the secondary skeleton consisting of interconnected grouting cement. However, because of the irregular, elongated and concave shapes conflicting with the requirement of aggregates, together with a stiffness much higher than that of asphalt binder (which can bear and transfer most of the load), it is hard to define whether cement grouted into air voids works mainly as a role of another aggregate or binder. Based on the X-ray computed tomography and digital image process method, this study aims to distinguish effective coarse aggregate-grouting cement contacts (cement working as aggregates) from noneffective ones (cement working only as binder). A contact classification method, as well as a fast contact calculation method, was proposed. The characteristics of different types of contacts were analyzed and two morphological interlocking indexes were established based on the concept of contact points and contact lines, respectively. A mechanical interlocking index was also back-calculated from a micromechanical model as a reference. The result reveals that there exists a good linear relationship between the mechanical and morphological interlocking indexes, verifying the validity of the contact classification method. Additionally, with a larger quantity than that of contacts between coarse aggregates, only one-sixth of aggregate-cement contacts are effective ones, the number of which is half of the coarse aggregates' contacts. As for contact lines, while the average length of effective aggregate-cement contacts is the same as that of aggregate contacts, the length of the noneffective ones is only the half. [ABSTRACT FROM AUTHOR]