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High strength and ductility in partially recrystallized Fe40Mn20Cr20Ni20 high-entropy alloys at cryogenic temperature
No full textThe effects of cold rolling and subsequent annealing on the microstructures and mechanical properties of Fe40Mn20Cr20Ni20 high-entropy alloys (HEAs) are investigated. The Cr-rich secondary phases with a tetragonal structure (σ phases) in the Fe40Mn20Cr20Ni20 HEAs are precipitated upon annealing at 600 °C-900 °C for 2 h. The prepared Fe40Mn20Cr20Ni20 HEA annealed at 800 °C for 2 h after cold rolling has a good combination of strength and elongation, with a high yield strength of 438 MPa, a high ultimate tensile strength of 676 MPa, and an excellent elongation to fracture of 32%. The mechanical properties at cryogenic temperature are better than those at room temperature. Typically, for the incompletely recrystallized alloy annealed at 700 °C, the yield strength, tensile strength, and elongation after fracture are increased by 26%, 22%, and 100%, respectively. This trend mainly depends on dislocation and twinning strengthening. The σ phases also improve the cryogenic tensile properties. Furthermore, the recrystallization kinetics of the Fe40Mn20Cr20Ni20 HEAs are explored to correlate with the deformation behavior
Challenges and prospects of Mg-air batteries: a review
No full textMg-air batteries, with their intrinsic advantages such as high theoretical volumetric energy density, low cost, and environmental friendliness, have attracted tremendous attention for electrical energy storage systems. However, they are still in an early stage of development and suffer from large voltage polarization and poor cycling performance. At present, Mg-air batteries with high rechargeability remain difficult to achieve, mainly because the discharge products [Mg(OH)2, MgO and MgO2] are thermodynamically and kinetically difficult to decompose at moderate voltage ranges. Therefore, it is crucial to optimize the reaction paths and kinetics from the electrodes to the batteries via the combination of materials design and first-principles calculations. In this review, remarkable progress is highlighted regarding the currently used materials for Mg-air batteries, including anodes, electrolytes, and cathodes. In addition, the corresponding reaction mechanisms are comprehensively surveyed. Finally, future perspectives for rechargeable Mg-air batteries with decreased voltage polarization and improved cycling performance are also described for further practical applications
STEMIN and YAP5SA synthetic modified mRNAs regenerate and repair infarcted mouse hearts
No full textIntroduction: The adult heart lacks the regenerative capacity to self-repair. Serum response factor (SRF) is essential for heart organogenesis, sarcomerogenesis, and contractility. SRF interacts with co-factors, such as NKX2.5 and GATA4, required for cardiac specified gene activity. ETS factors such as ELK1 interact with SRF and drive cell replication. To weaken SRF interactions with NKX2.5 and GATA4, one mutant, SRF153(A3) named STEMIN, did not bind CArG boxes, yet induced stem cell factors such as NANOG and OCT4, cardiomyocyte dedifferentiation, and cell cycle reentry. The mutant YAP5SA of the Hippo pathway also promotes cardiomyocyte proliferation and growth.Aim: Infarcted adult mouse hearts were injected with translatable STEMIN and YAP5SA mmRNA to evaluate their clinical potential,Methods and Results: Mice were pulsed one day later with alpha-EDU and then heart sections were DAPI stained. Replicating cells were identified by immuno-staining against members of the DNA replisome pathway that mark entry to S phase of the cell cycle. Echocardiography was used to determine cardiac function following infarcts and mRNA treatment. To monitor cardiac wall repair, microscopic analysis was performed, and the extent of myocardial fibrosis was analyzed for immune cell infiltration. Injections of STEMIN and YAP5SA mmRNA into the left ventricles of infarcted adult mice promoted a greater than 17-fold increase in the DAPI stained and alpha-EDU marked cardiomyocyte nuclei, within a day. We observed de novo expression of phospho-histone H3, ORC2, MCM2, and CLASPIN. Cardiac function was significantly improved by four weeks post-infarct, and fibrosis and immune cell infiltration were diminished in hearts treated with STEMIN and YAP5SA mmRNA than each alone.Conclusion: STEMIN and YAP5SA mmRNA improved cardiac function and myocardial fibrosis in left ventricles of infarcted adult mice. The combinatorial use of mmRNA encoding STEMIN and YAP5SA has the potential to become a powerful clinical strategy to treat human heart disease
A comparative study of energy management systems under connected driving: cooperative car-following case
No full textIn this work, we propose connected energy management systems for a cooperative hybrid electric vehicle (HEV) platoon. To this end, cooperative driving scenarios are established under different car-following behavior models using connected and automated vehicles technology, leading to a cooperative cruise control system (CACC) that explores the energy-saving potentials of HEVs. As a real-time energy management control, an equivalent consumption minimization strategy (ECMS) is utilized, wherein global energy-saving is achieved to promote environment-friendly mobility. The HEVs cooperatively communicate and exchange state information and control decisions with each other by sixth-generation vehicle-to-everything (6G-V2X) communications. In this study, three different car-following behavior models are used: intelligent driver model (IDM), Gazis–Herman–Rothery (GHR) model, and optimal velocity model (OVM). Adopting cooperative driving of six Toyota Prius HEV platoon scenarios, simulations under New European Driving Cycle (NEDC), Worldwide Harmonized Light Vehicle Test Procedure (WLTP), and Highway Fuel Economy Test (HWFET), as well as human-in-the-loop (HIL) experiments, are carried out via MATLAB/Simulink/dSPACE for cooperative HEV platooning control via different car-following-linked-vehicle scenarios. The CACC-ECMS scheme is assessed for HEV energy management via 6G-V2X broadcasting, and it is found that the proposed strategy exhibits improvements in vehicular driving performance. The IDM-based CACC-ECMS is an energy-efficient strategy for the platoon that saves: (i) 8.29% fuel compared to the GHR-based CACC-ECMS and 10.47% fuel compared to the OVM-based CACC-ECMS under NEDC; (ii) 7.47% fuel compared to the GHR-based CACC-ECMS and 11% fuel compared to the OVM-based CACC-ECMS under WLTP; (iii) 3.62% fuel compared to the GHR-based CACC-ECMS and 4.22% fuel compared to the OVM-based CACC-ECMS under HWFET; and (iv) 11.05% fuel compared to the GHR-based CACC-ECMS and 18.26% fuel compared to the OVM-based CACC-ECMS under HIL
Designs, motion mechanism, motion coordination, and communication of bionic robot fishes: a survey
No full textIn the last few years, there have been many new developments and significant accomplishments in the research of bionic robot fishes. However, in terms of swimming performance, existing bionic robot fishes lag far behind fish, prompting researchers to constantly develop innovative designs of various bionic robot fishes. In this paper, the latest designs of robot fishes are presented in detail, distinguished by the propulsion mode. New robot fishes mainly include soft robot fishes and rigid-soft coupled robot fishes. The latest progress in the study of the swimming mechanism is analyzed on the basis of summarizing the main swimming theories of fish. The current state-of-the-art research in the new field of motion coordination and communication of multiple robot fishes is summarized. The general research trend in robot fishes is to utilize more efficient and robust methods to best mimic real fish while exhibiting superior swimming performance. The current challenges and potential future research directions are discussed. Various methods are needed to narrow the gap in swimming performance between robot fishes and fish. This paper is a first step to bring together roboticists and marine biologists interested in learning state-of-the-art research on bionic robot fishes
Impact of intrapartum antibiotics on the developing microbiota: a review
No full textThe perinatal period sets the basis for the later physiological and immune homeostasis of the individual, with the intestinal microbiota being an important contributor to driving this homeostasis development. Therefore, the initial establishment and later development of the microbiota during early life may play a key role in later health. This early establishment of the intestinal microbiota is known to be affected by several factors, with gestational age, delivery mode, and feeding habits being extensively studied ones. Other factors are not so well understood, although knowledge has been accumulating in the last years. Among them, a factor of great relevance is the effect of perinatal exposure to antibiotics. Administration of intrapartum antimicrobial prophylaxis (IAP) to women during the delivery process represents the most common form of exposure to antibiotics during the perinatal period, present in around 30% of deliveries. During the last decade, evidence has accumulated demonstrating that IAP alters intestinal microbiota development in neonates. Moreover, recent evidence indicates that this practice may also be altering the infant intestinal resistome by increasing the levels of some antibiotic resistance genes. This evidence, as reviewed in this manuscript, suggests the interest in promoting the rational use of IAP. This practice has significantly reduced the risk of neonatal infections, but now the accumulating knowledge suggests the need for strategies to minimize its impact on the neonatal microbiota establishment
Preparation and application of 0D, 2D and 3D molybdenite: a review
No full textMolybdenite (MoS2) has been widely used in the fields of catalysis, desalination, energy storage and conversion and optoelectronics as a result of its unique crystal structures and unusual properties. In the last decade, the modification of the surface, structural and semiconducting properties of zero-, two- and three-dimensional (0D, 2D and 3D) MoS2 for enhanced applications has attracted considerable attention. In this review, we summarize the synthesis, modification methods and application of 0D, 2D and 3D MoS2. The unique structures and properties of 0D, 2D and 3D MoS2 are first introduced. Next, the preparation methods of 0D, 2D and 3D MoS2 are summarized. The modification methods, including surface, structural and composite engineering, for enhancing the physical and chemical properties of 0D, 2D and 3D are also discussed. Finally, inspired by natural and modified MoS2, future suggestions for the design of novel 0D, 2D and 3D MoS2 for various applications are also suggested. This review offers new insights into the design and construction of novel and efficient 0D, 2D and 3D MoS2 for practical applications
Magnetic-assisted surgery: the road from laparoscopy to robotics
No full textThe incorporation of magnetic fields into surgery to reduce the invasiveness of minimally invasive surgery led to the creation of magnetic-assisted surgery. External magnets coupled with their internal counterparts assist during surgical procedures, avoiding the need for additional trocars. Multiple advances have been made in this field in the past 15 years, with new promising technologies being developed. This review centers on the history of magnetic-assisted surgery and the available evidence of its safety, benefits and discusses the very promising combination of this new paradigm-shift technology with robotics
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