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Astaxanthine (AST) has important biological activities including antioxidant and anti-inflammatory effects that could alleviate neurological and heart diseases, but its role in the prevention of cisplatin-induced hearing loss (CIHL) is not yet well understood. In our study, a steady interaction between AST and the E3 ligase adapter Kelch-like ECH-associated protein 1, a predominant repressor of nuclear factor erythroid 2-related factor 2 (NRF2), was performed and tested via computer molecular docking and dynamics. AST protected against cisplatin-induced ototoxicity via NRF2 mediated pathway using quantitative PCR and Western blotting. The levels of reactive oxygen species (ROS) and mitochondrial membrane potential revealed that AST reduced ROS overexpression and mitochondrial dysfunction. Moreover, AST exerted anti-apoptosis effects in mouse cochlear explants using immunofluorescence staining and HEI-OC1 cell lines using quantitative PCR and Western blotting. Finally, AST combined with poloxamer was injected into the middle ear through the tympanum, and the protection against CIHL was evaluated using the acoustic brain stem test and immunofluorescent staining in adult mice. Our results suggest that AST reduced ROS overexpression, mitochondrial dysfunction, and apoptosis via NRF2-mediated pathway in cisplatin-exposed HEI-OC1 cell lines and mouse cochlear explants, finally promoting cell survival. Our study demonstrates that AST is a candidate therapeutic agent for CIHL. Astaxanthine protects against cisplatin-induced ototoxicity and hearing loss by NRF2 signaling activation that significantly increase the mitochondrial membrane potential and reduce reactive oxygen species. [Display omitted] [ABSTRACT FROM AUTHOR]

The microstructure and mechanical properties of flame-resistant AZX912 magnesium alloy extruded at different temperatures in the range of 250–400 °C were investigated. With decreasing extrusion temperature from 400 °C to 250 °C, the grain size of dynamically recrystallized grains significantly decreased from 13.6 to 1.8 µm, and the amount of fine Mg 17 Al 12 precipitates, with sizes of 50–200 nm, increased due to dynamic precipitation. The extrusion texture, with the basal plane and < 10 1 ¯ 0 > direction, mostly parallel to the extrusion direction, was remarkably strengthened as the extrusion temperature increased. This may be attributed to the enhanced activity of the prismatic slip. Nanoscale Mg 17 Al 12 precipitates significantly enhanced the mechanical strength, but deteriorated the ductility. The bar extruded at 250 °C exhibited the highest mechanical strength, which was due to the combined effect of the remarkably refined grain structure and the large amount of nanoscale Mg 17 Al 12 precipitates. The extrusion at 400 °C resulted in the lowest tensile elongation, which was attributed to both grain coarsening and basal texture strengthening. The bar extruded at 300 °C exhibited a good balance between mechanical strength and tensile ductility. [ABSTRACT FROM AUTHOR]

The effects of aging precipitation on microstructure, deep drawing formability and tensile properties, were investigated for Mg-6Al-1Zn (AZ61) alloy sheets. The alloy aged at 175 °C for 96 h with high strength exhibited a significant improvement in deep drawability with an increased limiting drawing ratio (LDR) from 1.5 to 1.9, when slightly increasing deformation temperature from room temperature to 100 °C. This LDR (1.9) was even larger than that (1.75) of the unaged alloy drawn at 100 °C. The improved deep drawability can be attributed to the prevention of cracking at the edge of drawn cup, which is closely related to the restrictions of growth of tensile twins and basal slip due to Mg 17 Al 12 precipitates, resulting in the delayed texture strengthening during deformation. The proposed idea of utilizing aging precipitation provides a new strategy for the development of Mg alloy sheets with superior deep drawing formability and high strength. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: A matrix Kalman filter (MKF) has been implemented for a navigation system using point-based visual and inertial sensors. The observability conditions have been proved by the observability rank criterion based on Lie derivatives. The conditions are: (a) at least one degree of rotational freedom is excited and (b) at least three observed points are not collinear where any two points are linearly independent. Experimental results have demonstrated that the proposed algorithm obtains the same accurate as the line-based algorithm. [Copyright &y& Elsevier]

Abstract: The microstructural and textural evolution during post-annealing as well as mechanical properties of a Mg–4Y–3RE magnesium alloy sheet processed by differential speed rolling at 823K were investigated. The as-rolled sheet exhibits deformation microstructure regardless of the high rolling temperature. Static recrystallization occurs around second-phase particles as a result of particle-stimulated nucleation and also at pre-existing grain boundaries due to solute effects of rare-earth elements, resulting in randomization of basal texture. Despite a large amount of second-phase particles, the weakened texture leads to a moderate stretch formability with an Erichsen value of 4.4. [Copyright &y& Elsevier]

Abstract: The recrystallization and grain growth behaviour of Mg–3Al–1Zn alloy sheets with a deformation microstructure, obtained by a combination of high-temperature rolling and subsequent warm rolling, was investigated at different stages of annealing. The basal texture was significantly weakened as a result of the formation of new grains with a largely altered c-axis orientation relative to the initial basal orientation owing to discontinuous static recrystallization during primary recrystallization. The new grains nucleated mostly at the pre-existing grain boundaries rather than at the intersections of twins or within the twins. Subsequent grain growth led to further progression of the texture weakening accompanied by an enhancement in the basal pole inclination. [Copyright &y& Elsevier]

Differential speed rolling (DSR) was carried out on commercial pure titanium at rolling temperatures from room temperature to 773K. The basal texture appears when the rolling temperature is higher than 573K and it lacks stability during annealing. Originating from texture effects, the DSRed sheet exhibits a larger Lankford value and a smaller planar anisotropy, which lead to a remarkable improvement in stretch formability regardless of a decrease in tensile elongation compared with symmetrically rolled sheet. [Copyright &y& Elsevier]

The Mg–3Al–1Zn magnesium alloy sheets with initial extrusion and casting microstructures were symmetrically rolled at a high temperature of 823K, followed by a warm rolling at 498K. The initial texture plays a vital role in texture development and results in inclination angle of split basal pole varying from ±15° to ±40°. The sheet rolled perpendicular to extrusion direction exhibits a homogeneous microstructure with an inclination angle of ±25° and the highest Erichsen value of 9.7. [Copyright &y& Elsevier]

Mg–3Al–1Zn alloy sheets were rolled at high temperatures up to 823K and subsequently rolled at 498K using differential speed rolling. The basal texture intensity dramatically weakens with a largely tilted basal pole after annealing. The Erichsen value significantly increases from 3.7 to 9.5 with an increase in the rolling temperature from 498 to 823K prior to warm rolling due to texture effects. This high Erichsen value is comparable to those of aluminum alloys. [Copyright &y& Elsevier]

The influence of reduction per pass over the range of 9–63% on the microstructure and texture of Mg–3Al–1Zn magnesium alloy sheets processed by differential speed rolling at the same total reduction of 63% have been investigated. With increasing reduction per pass, the number of unidirectional shear bands increases, resulting in a more homogeneous microstructure and a weaker basal texture at mid-layer. The inclination direction of the basal pole with respect to the rolling direction depends on the reduction per pass. [Copyright &y& Elsevier]

Mg–6Al–1Zn magnesium alloy sheets were rolled at high temperatures of 723–793K using differential speed rolling. The Erichsen value remarkably increases about 1.5 times due to the weakened basal texture regardless of the coarser grains with increasing the rolling temperature from 723 to 793K. The sheet rolled at 793K exhibits a combination of a superior stretch formability with an Erichsen value of 7.0 and a high tensile strength of 300MPa at room temperature. [Copyright &y& Elsevier]

• Mg-3Zn-0.5Ca-0.5Al-xMn alloys with different Mn contents were investigated. • Mechanical strength significantly improved with increasing Mn content. • High strength and high formability were simultaneously achieved in 1 wt% Mn alloy. • 1 wt% Mn alloy also has high thermal conductivity regardless of high Mn content. • Excellent properties are related to dense Al-Mn nanoscale spherical precipitates. [Display omitted] Tensile properties, formability and thermal conductivity of Mg-3Zn-0.5Ca-0.5Al-xMn (x: 0.1–1.5 in wt%) sheet alloys with different Mn contents were investigated. Benefitting from dense Al-Mn nanoscale spherical precipitates, yield strength was significantly enhanced by 39 MPa with increasing the Mn content from 0.1 wt% to 1 wt%. In the meanwhile, excellent formability was maintained with Erichsen values larger than 8 mm. Further increasing the Mn content to 1.5 wt% did not contribute to strengthening due to the formation of coarse β-Mn particles. In spite of larger additive amount, thermal conductivity improved for the 1 wt% Mn added alloy compared to the 0.1 wt% Mn added alloy due to the increased amount of Al-Mn nanoscale spherical precipitates, which reduced a content of Al solute atoms. High strength (average yield strength: 180 MPa), high formability (Erichsen value: 8.5 mm) and high thermal conductivity (133 W/(m K)) were simultaneously achieved in the 1 wt% Mn added alloy. [ABSTRACT FROM AUTHOR]

Poor formability at room temperature (RT) has been the main bottleneck for a wider range of applications of concentrated Mg–Al–Ca(–Zn) sheet alloys. Here, we report that RT stretch formability of concentrated Mg–Al–Zn–Ca alloy sheets can be improved substantially by increasing the final rolling temperature. A Mg–6Al–1Zn–1Ca alloy sheet subjected to 510 °C final rolling shows an index Erichsen (I.E.) value of 7.9 mm, which is significantly higher than that of the same sheet subjected to 450 °C final rolling (4.1 mm). More excitingly, 510 °C final rolled Mg–6Al–1Zn–2Ca (wt%) alloy sheet exhibits a large I.E. value of 8.0 mm which has never been achieved in 2 wt% Ca-containing Mg alloys. A systematic microstructural investigation indicates that the substantial improvement in stretch formability of Mg–6Al–1Zn–xCa (x=1, 2) alloy sheets is mainly associated with weakened basal textures. To clarify the mechanisms responsible for the weak basal textures developed in the high temperature rolled sheets, electron backscatter diffraction (EBSD) assisted slip trace analysis and quasi-in-situ EBSD method were employed. EBSD-assisted slip trace analysis on the side surface of as-rolled Mg–6Al–1Zn–1Ca alloy sheets indicates that the activity of pyramidal slip increases significantly by increasing the final rolling temperature from 450 to 510 °C. During subsequent annealing, grains deformed by pyramidal slip evolve into new recrystallized grains with a wide spectrum of orientations, which plays a key role in the development of the weaker basal texture. [Display omitted] [ABSTRACT FROM AUTHOR]

WxAg100−x alloy powders and bulk alloys consisting of metastable solid solution and nanocrystals were prepared by mechanical alloying (MA) and shock compression. The MA-treated (21 h) powder for x=90 showed the X-ray diffraction (XRD) pattern of a single phase of b.c.c. structure, and those for x≤80 showed the XRD patterns of two-phase mixtures of b.c.c. and f.c.c. structures. The lattice parameters of the b.c.c. structure phases increased with milling time and approached saturation values at about 15 h. The shock-consolidated bulk alloys for x=70 and 80 consisted of two-layer structures of a thick undecomposed layer and a thin decomposed one. The Vickers hardnesses of the undecomposed areas were much higher than those of the decomposed areas in the shock-consolidated bulk alloys. [Copyright &y& Elsevier]

Low flame resistance and inferior mechanical properties are critical issues in widening applications of wrought magnesium alloys as a structural component. To address these issues, the present authors attempted to develop a flame-resistant magnesium–silver-based sheet alloy with excellent room temperature (RT) formability. It was found that the ignition temperature of Mg–1.5 wt%Ag–x wt.%Ca alloy was significantly increased with increasing the Ca content up to 2 wt%. The 2 wt% Ca-containing alloy exhibited a non-flammability characteristic upon 1000 °C due to the formation of compact and dense CaO film on the surface. Strength and in-plane yield anisotropy were enhanced with increasing the Ca content, which were mainly associated with a finer microstructure and a denser distribution of Mg 2 Ca second phase particles. In contrast, stretch formability was decreased with increasing the Ca content due to an increased number of the Mg 2 Ca particles. A compositionally optimized Mg–1.5Ag–1Ca (wt.%) alloy showed a high ignition temperature of 912.5 °C with a large index Erichsen value of 7.8 mm at RT. • The flame-resistance of Mg–1.5Ag–xCa alloys is significantly improved with increasing the Ca content. • Strength and in-plane yield anisotropy of Mg–1.5Ag–xCa alloys are enhanced with increasing the Ca content. • Mg–1.5Ag–xCa (x = 0.1, 0.5, 1, and 2 wt%) alloys show weak and ring-like basal textures. • Mg–1.5Ag–1Ca (wt.%) alloy exhibits a high ignition temperature of 912.5 °C with a large index Erichsen value of 7.8 mm. [ABSTRACT FROM AUTHOR]

This work investigated effects of silver (Ag) content on the microstructure, texture and mechanical properties of magnesium–silver–calcium alloys by a combined experimental and numerical approach. A series of ternary magnesium–silver–calcium alloys with Ag concentrations between 0.3 and 12 wt% were prepared by hot-extrusion, hot-rolling followed by annealing. As-rolled sheets showed rolling direction split textures with double peaks irrespective of the Ag content. A new component where (0002) basal poles tilted from the normal direction toward the transverse direction (TD) appeared when the Ag content was increased to 1 wt% after annealing. The Mg–xAg–0.1Ca (x = 0.3, 1, 2 and 3) alloys showed excellent room temperature (RT) formability, which could be mainly ascribed to weak basal textures developed after annealing. When the Ag content was increased to 6 wt%, a weak TD-split texture with a homogeneous fine-grained microstructure was developed, which resulted in excellent RT formability and high strength. In contrast, the Mg–12Ag–0.1Ca alloy showed much lower RT formability and ductility in comparison with Mg–Ag–Ca alloys with lower Ag concentrations due to the presence of coarse AgMg 4 particles. Visco-plastic self-consistent simulation results revealed that the activity of prismatic slip was increased with increasing the Ag content and the enhanced activity of prismatic during rolling may partially lead to the formation of TD-split texture in the formable Mg–Ag–Ca alloys during annealing. • Mg–xAg–0.1Ca (x = 0.3, 1, 2, 3, 6 and 12 wt%) alloys showed weak basal textures. • Mg–0.1Ca alloys with Ag no more than 3 wt% showed excellent formability. • A Mg–6Ag–0.1Ca (wt.%) alloy exhibited a high strength and excellent formability. • Activity of prismatic slip increased with increasing Ag content. [ABSTRACT FROM AUTHOR]

Small amounts of transition elements: Ti, Mn, Fe, Co, and Ni, have been added to a Mg–0.1Ca (wt%) alloy to elucidate their additions on the microstructure and room temperature (RT) mechanical properties. Only Ni was effective in weakening the texture intensity and thus led to the improvement in RT formability and ductility, whereas the other elements were basically no effect. The microstructural characterization by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) in conjunction with energy-dispersive X-ray spectrometry (EDS) and numerical simulation using a grain boundary (GB) phase model indicates that the Ca and Ni co-segregated to the GB of the Ni-containing alloy, while the GB of the other alloys was enriched with Ca only. Further investigations by a correlative electron backscatter diffraction and STEM-EDS reveal that the transverse direction (TD) oriented GBs had significantly lower concentration of Ca and Ni compared to the basal-oriented GBs, which resulted in the development of the TD-split texture in the Ni-containing alloy. A compositionally optimized Mg–0.1Ca–0.1Ni (wt%) alloy showed a large index Erichsen value of 8.5 mm in the sheet form, and exhibited a high tensile yield strength of 238 MPa with a moderate fracture elongation of 14% in the form of an extruded rod. Due to the addition of small amounts of alloying elements, the newly developed Mg–0.1Ca–0.1Ni alloy had an excellent thermal conductivity of 154 W/(m·K) which is even higher than that of a commercial 5052 Al alloy. [Display omitted] [ABSTRACT FROM AUTHOR]