Metal/intermetallic laminate composites can improve the mechanical properties of intermetallic materials using metal layers. In recent years, titanium aluminide intermetallics have received increasing attention due to...Metal/intermetallic laminate composites can improve the mechanical properties of intermetallic materials using metal layers. In recent years, titanium aluminide intermetallics have received increasing attention due to their excellent performance properties, such as high melting point, high specific strength and stiffness, and good corrosion resistance. However, the low fracture toughness of Al3Ti alloys at room temperature has greatly limited their application, and fiber or particle reinforcement has not shown a significant toughening effect. Research into the reinforcing effects of the interface and near-interface zone on the fracture behavior of Al3Ti is lacking. Ti/Al3Ti metal/intermetallic laminate composite was synthesized from titanium and aluminum foils using vacuum hot-pressed sintering technology. The microstructure of the prepared material was analyzed by scanning electron microscope and electron backscattered diffraction. Results illustrate that both Ti and Al3Ti were single-phase and there was a noticeable stress concentration on the interface. To obtain indentation and cracks, loads were applied to different locations of the composite by a microhardness tester. The growth path of the cracks was then observed under microscope, showing that crack propagation was prevented by the interface between the Ti and Al3Ti layers, and the cracks that propagated parallel to the laminate shifted to the interface. Fracture toughness of the different areas, including Al3Ti layers, interface, and near-interface zone, were measured by the indentation fracture method. The fracture toughness at and near the interface was 1.7 and 2 times that of the Al3Ti layers, respectively. Results indicate that crack blunting and crack front convolution by the laminate structure was primarily responsible for increased toughness.展开更多
Gastric cancer(GC)poses a serious threat worldwide with unfavorable prognosis mainly due to late diagnosis and limited therapies.Therefore,precise molecular classification and search for potential targets are required...Gastric cancer(GC)poses a serious threat worldwide with unfavorable prognosis mainly due to late diagnosis and limited therapies.Therefore,precise molecular classification and search for potential targets are required for diagnosis and treatment,as GC is complicated and heterogeneous in nature.Accumulating evidence indicates that epigenetics plays a vital role in gastric carcinogenesis and progression,including histone modifications,DNA methylation and non-coding RNAs.Epigenetic biomarkers and drugs are currently under intensive evaluations to ensure efficient clinical utility in GC.In this review,key epigenetic alterations and related functions and mechanisms are summarized in GC.We focus on integration of existing epigenetic findings in GC for the bench-to-bedside translation of some pivotal epigenetic alterations into clinical practice and also describe the vacant field waiting for investigation.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(No.11602230)the Program for Innovative Research Team in Science and Technology in University of Henan Province(No.18IRTSTHN015)+1 种基金the Key Scientific Projects of University in Henan Province(No.20B430021)the Young talent promotion project of Henan Province(No.2019HYTP002).
文摘Metal/intermetallic laminate composites can improve the mechanical properties of intermetallic materials using metal layers. In recent years, titanium aluminide intermetallics have received increasing attention due to their excellent performance properties, such as high melting point, high specific strength and stiffness, and good corrosion resistance. However, the low fracture toughness of Al3Ti alloys at room temperature has greatly limited their application, and fiber or particle reinforcement has not shown a significant toughening effect. Research into the reinforcing effects of the interface and near-interface zone on the fracture behavior of Al3Ti is lacking. Ti/Al3Ti metal/intermetallic laminate composite was synthesized from titanium and aluminum foils using vacuum hot-pressed sintering technology. The microstructure of the prepared material was analyzed by scanning electron microscope and electron backscattered diffraction. Results illustrate that both Ti and Al3Ti were single-phase and there was a noticeable stress concentration on the interface. To obtain indentation and cracks, loads were applied to different locations of the composite by a microhardness tester. The growth path of the cracks was then observed under microscope, showing that crack propagation was prevented by the interface between the Ti and Al3Ti layers, and the cracks that propagated parallel to the laminate shifted to the interface. Fracture toughness of the different areas, including Al3Ti layers, interface, and near-interface zone, were measured by the indentation fracture method. The fracture toughness at and near the interface was 1.7 and 2 times that of the Al3Ti layers, respectively. Results indicate that crack blunting and crack front convolution by the laminate structure was primarily responsible for increased toughness.
基金The fellowship of the China Postdoctoral Science Foundation,No.2020M682594.
文摘Gastric cancer(GC)poses a serious threat worldwide with unfavorable prognosis mainly due to late diagnosis and limited therapies.Therefore,precise molecular classification and search for potential targets are required for diagnosis and treatment,as GC is complicated and heterogeneous in nature.Accumulating evidence indicates that epigenetics plays a vital role in gastric carcinogenesis and progression,including histone modifications,DNA methylation and non-coding RNAs.Epigenetic biomarkers and drugs are currently under intensive evaluations to ensure efficient clinical utility in GC.In this review,key epigenetic alterations and related functions and mechanisms are summarized in GC.We focus on integration of existing epigenetic findings in GC for the bench-to-bedside translation of some pivotal epigenetic alterations into clinical practice and also describe the vacant field waiting for investigation.
