Autophagy regulates the maturation of hematopoietic precursors in the embryo

An understanding of the mechanisms regulating embryonic hematopoietic stem cell (HSC) development would facilitate their regeneration. The aorta-gonad-mesonephros region is the site for HSC production from hemogenic endothelial cells (HEC). While several distinct regulators are involved in this process, it is not yet known whether macroautophagy (autophagy) plays a role in hematopoiesis in the pre-liver stage. Here, we show that different states of autophagy exist in hematopoietic precursors and correlate with hematopoietic potential based on the LC3-RFP-EGFP mouse model. Deficiency of autophagy-related gene 5 (Atg5) specifically in endothelial cells disrupts endothelial to hematopoietic transition (EHT), by blocking the autophagic process. Using combined approaches, including single-cell RNA-sequencing (scRNA-seq), we have confirmed that Atg5 deletion interrupts developmental temporal order of EHT to further affect the pre-HSC I maturation, and that autophagy influences hemogenic potential of HEC and the formation of pre-HSC I likely via the nucleolin pathway. These findings demonstrate a role for autophagy in the formation/maturation of hematopoietic precursors.</p

Effect of steam reinjection mass flow rate on the SOFC–GT system with steam reinjection

A solid oxide fuel cell (SOFC) is regarded as the first choice of high-efficiency and clean power generation technology in the 21st century due to its characteristics of high power generation efficiency and low pollutant emission. In this paper, hydrogen is used as a fuel for SOFCs using the EBSILON platform. A sensitivity analysis of the solid oxide fuel cell–gas turbine (SOFC–GT) system with steam reinjection is carried out to investigate the effect of the steam reinjection mass flow rate on the improvement of the electrical efficiency of the system and on the values of the other parameters. The results show that the variation in the steam reinjection mass flow rate has an effect on other parameters. Changes in several parameters affect the electrical efficiency of the system, which reaches 74.11% at a pressure ratio of 10, SOFC inlet temperature of 783.15 K, turbine back pressure of 70 kPa, and steam reinjection mass flow rate of 6.16 kg/s. Future research can optimize the overall parameter selection of the system in terms of economy and other aspects

Single cell atlas for 11 non-model mammals, reptiles and birds.

The availability of viral entry factors is a prerequisite for the cross-species transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Large-scale single-cell screening of animal cells could reveal the expression patterns of viral entry genes in different hosts. However, such exploration for SARS-CoV-2 remains limited. Here, we perform single-nucleus RNA sequencing for 11 non-model species, including pets (cat, dog, hamster, and lizard), livestock (goat and rabbit), poultry (duck and pigeon), and wildlife (pangolin, tiger, and deer), and investigated the co-expression of ACE2 and TMPRSS2. Furthermore, cross-species analysis of the lung cell atlas of the studied mammals, reptiles, and birds reveals core developmental programs, critical connectomes, and conserved regulatory circuits among these evolutionarily distant species. Overall, our work provides a compendium of gene expression profiles for non-model animals, which could be employed to identify potential SARS-CoV-2 target cells and putative zoonotic reservoirs

ZrO2-Al2O3 LAMINATED CERAMICS AND THEIR TRIBOLOGICAL BEHAVIORS

ZrO2-Al2O3 laminated ceramics of 3 layers were prepared by dry-pressing and pressureless sintering, and their mechanical properties and toughening mechanisms were studied. Furthermore, their tribological behaviors and wear mechanisms under dry friction and water lubrication conditions were also investigated, and compared with those of monolayer ZrO2-Al2O3 ceramics under the same conditions. The results show that the bending strength, fracture toughness and hardness of the laminated ceramics are all better than those of the monolayer ceramics, moreover the friction factor and wear rate of the laminated ceramics are clearly lower than those of the monolayer ceramics. The excellent mechanical properties of the laminated ceramics, especially toughness, result mainly from effects of residual stress in the specially-designed layer, interface structure and phase transformation together. Good tribological properties of the laminated ceramics are supposed due to the high toughness and low shearing stress in the wear surface. The friction and wear of the composites are effectively decreased by water lubrication because of the transformation of the main wear mechanisms from abrasive and adhesive wear under dry friction to tribo-chemical and fatigue wear under water lubrication.3-layer structure ceramics, residual stress, wear mechanism, dry friction, water lubrication

Eutrophication Control of Lake/Reservoir Water Sources and Assurance of Drinking Water Safety in China Considering Global Climate Change

Lake and reservoir ecosystems face varying degrees of eutrophication and cyanobacterial bloom against the background of global climate change, which threatens the safety of drinking water supply. In this study, we reviewed the current status of eutrophication  and water quality of lake and reservoir water sources in China, and explored the challenges from the aspects of water source protection, purification process, pipe network distribution, and guarantee mechanism. Four targeted suggestions were recommended for guaranteeing drinking water safety: (1) strengthening environmental protection and ecological restoration of lake and reservoir drinking water sources, (2) promoting the construction of a scientific and technological support system for guaranteeing drinking water safety in the entire process, (3) building an intelligent supervision platform based on big data fusion, and (4) accelerating the system and mechanism innovation for guaranteeing lake and reservoir drinking water safety

Effect of Sr surface segregation of La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 − δ electrode on its electrochemical performance in SOC

The degradation mechanism of La0.6Sr0.4Co0.2Fe0.8O3 − δ (LSCF) electrode is investigated by examining its electrochemical behavior under equilibrium potential at elevated temperature and corresponding surface compositional changes. Diluted nitric acid etching treatment is conducted to confirm the correlation between the surface changes and the variation of electrochemical performance. It has been shown that the increase of polarization resistance of LSCF electrode has a linear dependence on the square root of time and arises from degradation of mass transfer process taking place at the gas-solid interface of electrode, such as oxygen adsorption/desorption and surface diffusion. Comparison of the behavior of the electrode before and after nitric acid treatment shows that the presence of surface inhibited species can account for the above observations. This inhibited species is confirmed by X-ray photoelectron spectroscopy to be a surface segregated Sr-based material, which supports the claim that surface Sr segregation is detrimental. A further lifespan study of LSCF electrode up to 158 h under 1 A/cm2 electrolysis current demonstrates that the current can improve and stabilize the performance, which could be ascribed to the removal of surface Sr species due to the incorporation of surface Sr back into the lattice of LSCF.NRF (Natl Research Foundation, S’pore)Published versio

High-temperature electrolysis of simulated flue gas in solid oxide electrolysis cells

The feasibility of the solid oxide electrolysis cell (SOEC) electrolysis of flue gas based on an electrolyte-supported LSCM-GDC/SSZ/LSCF-GDC (LSCM: La0.75Sr0.25Cr0.5Mn0.5O3-δ) single cell is comprehensively evaluated. Current density-voltage curves (I-V) and electrochemical impedance spectroscopy data (EIS) are recorded to characterize the electrochemical performance of SOEC. The results confirmed that the LSCM-GDC fuel electrode is chemically stable in the flue gas atmosphere. The results also showed that simulated SO2 with concentration of 15 ppm in the flue gas has a negligible influence on the cell at an electrolysis current density of ∼0.2 A cm−2. The O2 in the flue gas increases the electrolysis activity in the fuel electrode, thereby improving the efficiency of the SOEC electrolysis of flue gas. The co-existence of SO2 and O2 in flue gas can increase the electrolysis activity of SOEC electrolysis. The total resistance of the SOEC single cell at 800 °C under OCV is 2.21 Ω cm2, indicating that the SSZ-electrolyte-supported SOEC can be practically used for the effective SOEC electrolysis of flue gas containing SO2 and O2. The cell showed a stable voltage of 1.201 V for more than 100 h for the electrolysis of flue gas with SO2 and O2 at a current density of 0.5 A cm−2 and at a temperature of 800 °C. The post-mortem analysis showed that the microstructures of all cell components are stable after the SOEC long-term durability test