Search

The Mg–8Li dual phase alloy was deformed by multi-directional compression with different passes. Microstructure evolution of deformed Mg–8Li alloy was analyzed by electron backscatter diffraction. X-ray diffraction profile was used to calculate the dislocation density in α-Mg and β-Li phase to reveal the quantitively change trend under different compression passes. The mechanical properties were assessed through tensile and compressive tests. The Mg–8Li alloy exhibited optimal mechanical properties when compressed with 12 passes (sample 12MDC), with a compression yield strength of 183.1 MPa and a tensile yield strength of 124.2 MPa. The improved mechanical properties in sample 12MDC were attributed to an increase in {10 1‾ 2} twin and {101‾ 3}-{101‾ 2} double twin boundaries, along with the presence of sub-grain boundaries and a reduced grain size in the α-Mg phase. Additionally, the inconsistent results between microhardness and dislocation density calculation manifests the uneven distribution of dislocations in β-Li phase. Broken α-Mg phase brings more phase interface to relieve the strain in β-Li phase, which results to a decreased dislocation density in sample 12MDC (1.19 × 1011/m2). Results show that weaken tension-compression yield asymmetry and more even distribution of dislocation in both phases could be achieved when the compression passes increases to 12.

The orientation (including the c axis orientation and crystal direction parallel to rolling direction) evolution of grown recrystallization grains during annealing at 250 °C for 45–180 min in Mg–Zn-Gd alloy was characterized by quasi-in-situ electron backscatter diffraction method. An unusual grain orientation rotation during the process of static recrystallization grain growth, rather than common plastic deformation or recrystallization nucleation process, was observed. Due to the higher storage energy, the growth size in the early stage of annealing (1.41 μm) is larger than that in the late stage of annealing (0.73 μm) for most (∼76%) grains, and corresponding average c-axis rotation angles are 3.65° and 1.39°, respectively, indicating that the larger the increase in grain size, the greater the changing degree in grain orientation. It is speculated that the orientation rotation during grain growth process is mediated by the interaction between dislocations and grain boundaries. The results reported in the current paper can provide a new insight into the study on the relationship between preferential grain growth and non-basal texture formation in rare earth contained Mg alloys.

The study utilizes a multi-directional compression (MDC) process on a basal-textured ZK60 alloy with the aim of inducing extensive twinning, which is followed by an aging treatment on the pre-deformed sample. The mechanical response and corrosion behavior of the deformed and aged samples are systematically investigated. The MDC process effectively generates numerous {10 1‾ 2} twins with increased compression passes, resulting in the enhanced grain refinement. The interplay between twins and numerous dislocations formed during pre-deformation plays a crucial role in altering both the distribution and morphology of the second phase precipitated during aging. During the aging process, the alloy exhibits a higher concentration of dense rod-like β′ phase and disk-like β″ phase. Remarkably, the compressive yield strength and ultimate strength of aged ZK60 alloy along the rolling direction are significantly improved without obvious compromise of ductility by pre-compression. Notably, the yield strength of the sample after 12-passes compression and aging (APD-12) is approximately 45 % higher than that of the sample without pre-compression (APD-0). Furthermore, the corrosion resistance of ZK60 alloy displays notable improvement upon pre-compression treatment. Specifically, the hydrogen evolution in the APD-12 sample is halved compared to the APD-0 sample. Electrochemical assessments were conducted on both pre-compressed and non-pre-compressed samples, revealing their distinct behaviors. Furthermore, an in-depth exploration has also been undertaken into the underlying mechanisms contributing to the enhancement of mechanical properties and corrosion resistance resulting from the pre-compression.

In this work, the dynamic, quasi-static response and twinning behavior of bimodal textured Mg–3Al–1Zn alloy is comparatively investigated at room temperature. The relationship between yield stress and bimodal texture is quantified and characterized as an increase of the yield stress with the increasing of the percentage of ⊥ED (extrusion direction) component; the ultimate strength under high strain rate (103 s−1) was quite higher than that under quasi-static condition (10−3 s−1); but, the yield stress was just the reverse. The competition between twin nucleation and growth is significantly affected by a coupled effect of strain rate and texture. Twin nucleation shows positive strain rate sensitivity and is largely enhanced by dynamic deformation. However, the twin growth tendency is bimodal texture and strain rate dependent: it is favorable under quasi-static condition for samples with more soft orientations, while for samples with more hard orientations, dynamic deformation promotes twin growth. It is also found that a higher strain rate can stimulate the activation of more twin variant types in bimodal textured magnesium alloys.

Introduction: Gastric cancer (GC) is one of the most common malignant tumors worldwide. Single-cell sequencing technology can achieve an accurate and unbiased assessment of cell heterogeneity. Therefore, it is necessary to explore the molecular characteristics of GC-related malignant cells at a single-cell resolution. Methods: Single-cell RNA sequencing GC profiles were collected from the Gene Expression Omnibus database. Moreover, feature gene sets of metabolic pathways and hypoxia signals were collected from the Molecular Signatures Database. The marker genes of specific cell types were collected from the published literature and CellMarker database. The R package InferCNV was used to calculate the copy-number variations of cells and to identify real cancer cells. The weighted relative pathway activity algorithm was used to evaluate the differences in metabolic activity between cell types. Results: Our study found that cancer epithelial cells exhibited individual differences in molecular features and showed metabolic heterogeneity. Oxidative phosphorylation and glycolytic pathway activity were the major contributors to the metabolic heterogeneity of cancer epithelial cells. Furthermore, we used the hypoxia signaling pathway to indirectly evaluate the oxygen content of cells and found that hypoxia contributed to the heterogeneity of cancer epithelial cells. Finally, functional identification of genes co-expressed with HIF1A showed that the reprogramming of the oxidative stress response contributed to the tumor malignant progression. Conclusions: This study described hypoxia-induced metabolic reprogramming of GC at a single-cell level, partially addressing the lack of insight into the heterogeneity of cancer cell metabolism when using traditional sequencing technology.

Silver nanowire (AgNW) films have been widely used as flexible transparent electrodes due to the high electrical conductance and high transmittance in the visible range. The infrared (IR) properties of AgNW films, however, are seldom discussed. Here, we show that ultrathin AgNWs present high transmittance in the visible range (∼95%) and high reflectance (60–70%) in the IR range of 8–14 μm. Such a significant difference makes AgNW films invisible to naked eyes but visible under an IR camera, being an ideal selection for anti-counterfeit technologies, while no excitation is required. We have demonstrated that AgNW films can be spray-coated on either flat or microstructured surfaces with high conformability and high scratch-resistance, and thus these anti-counterfeiting materials can be applied to a variety of applications. The AgNW-based anti-counterfeiting may be helpful for combating counterfeiting crimes in the fields of medicines, artwork, banknotes, brand luxuries, industrial parts, and so on. Keywords: Silver nanowires, Anti-counterfeiting, Infrared light, Excitation-free, Conformability

Methyl-CpG binding protein 2 (MeCP2) has recently been characterized as an oncogene frequently amplified in several types of cancer. However, its precise role in gastric cancer (GC) and the molecular mechanism of MeCP2 regulation are still largely unknown. Here we report that MeCP2 is highly expressed in primary GC tissues and the expression level is correlated with the clinicopathologic features of GC. In our experiments, knockdown of MeCP2 inhibited tumor growth. Molecular mechanism of MeCP2 regulation was investigated using an integrated approach with combination of microarray analysis and chromatin immunoprecipitation sequencing (ChIP-Seq). The results suggest that MeCP2 binds to the methylated CpG islands of FOXF1 and MYOD1 promoters and inhibits their expression at the transcription level. Furthermore, we show that MeCP2 promotes GC cell proliferation via FOXF1-mediated Wnt5a/β-Catenin signaling pathway and suppresses apoptosis through MYOD1-mediated Caspase-3 signaling pathway. Due to its high expression level in GC and its critical function in driving GC progression, MeCP2 represents a promising therapeutic target for GC treatment.