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The ejector is a crucial component of the hydrogen circulation system of proton exchange membrane fuel cell (PEMFC), which is widely used because of its simple structure, reliable operation, and no additional power consumption. However, the current research on pulsed ejectors is still lacking and in-depth. In this study, CFD modeling is conducted on the ejector, and the pulsed gas flow is simulated by user define function (UDF), and the influence of the pulsed gas flow on the entrainment performance of the ejector is analyzed. The results show that, compared with the steady-state condition, the entrainment performance of the ejector using pulsed gas flow under different primary flow pressures is improved, and the maximum entrainment ratio is 3.195 under steady-state conditions and 3.507 under transient conditions, which is increased by 9.8%. The effect is especially pronounced at low pressure, where the entrainment ratio increases by 16.6%. And by comparing the gas flow of different pulse frequencies, it is found that when the pulse frequency is 1Hz, the ejector has the best entrainment performance. • The ejector with pulsed gas flow has significantly better entrainment performance. • At the low primary inlet pressure, the pulsed gas flow has a good effect on the entrain ment performance. • Pulsed gas flow can form a lower low-pressure area at the nozzle exit. • When the frequency of the pulsed gas flow is 1Hz, the entrainment ratio is maximum. [ABSTRACT FROM AUTHOR]

The microporous layer (MPL) as a part of diffusion medium has an important impact on mass transfer of proton exchange membrane fuel cell (PEMFC). In this study, MPLs of gas diffusion layers (GDLs) are prepared with different carbon blacks, and the properties of carbon blacks and their effects as MPLs on cell performance are systematically investigated. The results show that the GDL prepared by Acetylene Black (ACET) exhibits the best performance with a maximum power density up to 2.05 W cm−2. Moreover, it still maintains extremely high performance with increasing current density even at humidity condition of 100% relative humidity, which means its excellent water/gas transportation capacity. This study contributes to deeply understanding the correlations between the properties of MPL material itself and their corresponding performance exhibited in cell. It also provides an important reference for enhancing cell performance and further advancing the practical applications of MPLs in PEMFC field. [Display omitted] • This paper focus on the selection and optimization of MPL materials. • The physical characteristics of different GDLs are systematically compared. • Pore size distribution and surface wettability of GDLs are two key characteristics. • Properties of carbon blacks and their effects on cell performance are studied. [ABSTRACT FROM AUTHOR]

Remote Sensing Archaeology (RSA) is an innovative sub-discipline within archaeology that utilizes general Remote Sensing (RS) techniques to analyze data from ancient human-made structures. This analysis significantly contributes to understanding various facets of human history, such as cultures, practices, diversity, and evolution. Our study anticipates the forthcoming changes in the roles of RS archaeologists and the research framework of RSA. Emphasizing the necessity for archaeologists to comprehend remote, proximal, in-situ, and instrumental sensing technologies, as well as rapidly evolving digital advancements, such as Artificial Intelligence/Machine Learning (AI/ML), Big Data (BD), Cloud or Cyber Infrastructure (CI), and Digitalization Technology (DT). Drawing upon successful techniques and practices, we argue the efficacy of RSA in addressing historical, contemporary, and future challenges. This effectiveness becomes particularly pronounced as RSA transitions from archaeological prospecting to knowledge discovery using space technologies, represented by RS. Space Archaeology (SA), which we propose as an evolved stage of RSA for archaeological prospecting, builds upon the experiences and lessons gleaned from RSA's century-long journey. It not only extends the legacy of RSA but also signifies a shift in both the implication and methodology of sensing-based archaeological prospecting. SA, while advancing RSA, also aligns with the current trend of spatial thinking in archaeology amidst substantial transformations in RSA research. The perspectives outlined in this review aspire to positively shape the ongoing shift in archaeological spatial thinking. • The recent advance in remote sensing archaeology is reviewed. • The new paradigm of space archaeology is first described. • Specific focus is given to the understanding of past human–environment interactions. • Emerging trends and future perspectives are highlighted in four key areas. [ABSTRACT FROM AUTHOR]

This paper focuses on the nonlinear behaviors of offset-halves journal bearings (OHJBs), particularly under dynamic loading and journal misalignment. A new tribo-dynamic model is given to perform transient thermoelastohydrodynamic analysis in the crucial yet understudied domain of this novel structure. Bearing characteristics are compared among bi-directional misalignment, single-direction misalignment as well as alignment. The results demonstrate that the influence of bi-directional misalignment exerts dominance. Moreover, the evolution mechanisms of bi-directional misalignment and step loading on the time-varying stiffness and damping are evaluated. In addition, parametric analyses are done to emphasize key factors in the bearing design, including the horizontal offset and radial clearance, for better transient lubrication performance. This study enriches the structural optimum for dynamically loaded journal bearings. [Display omitted] [ABSTRACT FROM AUTHOR]

There is no doubt that the primary reason that firms encourage knowledge sharing is to drive innovation. As nutrients for innovation, what role do the different elements of intellectual capital play in this relationship? When we consider the ambidexterity of enterprise innovation—exploratory and exploitative—how do the different elements of intellectual capital affect the relationship between them? This study adopts a triadic perspective to divide intellectual capital into human, structural and relational capital. We analyzed 349 questionnaires from high-tech enterprises and found that knowledge sharing had a significantly positive effect on all three elements of intellectual capital, and human capital and structural capital had a positive effect on ambidextrous innovation. Relational capital had a positive effect on exploitative innovation but no significant effect on exploratory innovation. Unexpectedly, there was no direct effect of knowledge sharing on ambidextrous innovation, and the elements of intellectual capital play full mediations among them. This may suggest that firms should pay more attention to the role of relational capital when they adopt exploitative innovation. At the same time, we remind managers that innovation may be promoted only when knowledge sharing increases intellectual capital. Therefore, the misuse of management tools should be avoided, and ineffective management practices should be reduced. In addition, we explored the relationship between knowledge sharing and the open innovation paradigm and made some suggestions for future research. [ABSTRACT FROM AUTHOR]

Polycrystalline transparent In 2 O 3 semiconductive ceramics are successfully fabricated by oxygen atmosphere sintering for the first time. The starting rounded In 2 O 3 particles are obtained via pyrolyzing the nanoplate-like hydrated basic sulfate precursor prepared by a chemical precipitation route using hexamethylenetetramine as the precipitant. The silica additive dissolves into the In 2 O 3 lattice to form an interstitial solid solution, which promotes the diffusion rate during high-temperature densification process and thus helps to achieve good optical quality for In 2 O 3 ceramics. The created interstitial oxygen further compensates the oxygen vacancy in the ceramic body to result in a higher resistivity and lower carrier concentration / carrier mobility. The optical qualities of In 2 O 3 ceramics are also found to have slight effects on the resistivity, carrier mobility, carrier concentration, and Hall coefficient. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Polycrystalline transparent Tm 2 O 3 ceramics are successfully fabricated by means of chemical precipitation route plus vacuum sintering technique. Hexamethylenetetramine as the precipitant is dripped into thulium sulphate system to directly result in a hydrated basic sulphate precursor with an approximate chemical composition of Tm(OH) 1.7 (SO 4) 0.65 ∙2.1H 2 O, followed by pyrolysis to yield a sphere-like Tm 2 O 3 powder with an average particle size of ∼165 nm. During high-temperature sintering, the silica additive induces lattice distortion via the formation of interstitial solid solution and helps to achieve a uniform microstructure together with good optical quality. The best Tm 2 O 3 ceramic sample has in-line transmittances of ∼71 % at 880 nm and ∼76 % in partial middle infrared spectral region with maximal infrared cut-off at ∼11 μm. The thermal diffusion and thermal conductivity of the bulk both decrease as the temperature increases. [ABSTRACT FROM AUTHOR]

The increase in population, the development of industry and agriculture, and the exploitation and utilization of natural resources have inevitably caused a series of ecological and environmental problems, including trace metal pollution. Quantifying the influence of human activities on the metal concentrations of an aqueous environment is helpful for understanding the process and the relationship between socioeconomic development and ecological environmental quality at the macro level. We investigated how human activities and natural variabilities influence the concentrations and distributions of trace metals in the aquatic environment of the heavily sediment-laden Yellow River (> 5000 km). The results showed that the relevant indicators of human activities, such as the population density, average GDP, the number of industrial enterprises above a designated size, percent cropland, percent impervious surface, and the proportion of total crops sown area, had significant positive effect on the concentrations and distributions of some metals in the water environment with a weight of 33∼64%. Moreover, percent grassland and percent wetland exhibited a significant negative correlation with metals. Rapid population growth and socioeconomic development have accelerated the production of metals and other pollutants, that eventually enter the aquatic environment via runoff or other methods through a series of migrations and transformations; thus, the scope of pollution has gradually increased. Some artificially constructed prevention, control and repair measures have played a role in mitigating the effects of environmental pollutants, including metals. This study contributes to the development of effective strategies for controlling metal pollution in the Yellow River basin. [Display omitted] • Distributions of trace metals were investigated in the sediment-laden Yellow River. • Concentration of most metals in water environment showed a significant difference. • Human activities positively affect metal concentrations with a weight of 33∼64%. • Grassland and wetland mitigated metal pollution load into the sediment-laden river. [ABSTRACT FROM AUTHOR]

[Display omitted] • The main source of wine aroma and the formation mechanism are discussed. • The main influencing factors of aroma formation are analyzed. • The production and control of aroma in the winemaking process are concluded. As an important sensory indicator, aroma affects the quality of wine and consumer preference. In this review, the following aspects are comprehensively analyzed: (1) Varietal aroma, fermentation aroma and aging aroma formation mechanism include metabolic pathways etc. (2) The main factors affecting the aroma formation include environment, raw and auxiliary materials and brewing process. (3) In the process of winemaking, environmental factors can be controlled by regulating deficit irrigation, leaf removal and reflective mulch; the quality of raw and auxiliary materials can also be controlled through the varieties breeding of grape and yeast; flash evaporation, ultrasonic aging and other advanced brewing technologies can be used to synergistically control aroma formation. In the future, the wine brewing process can be controlled from the following aspects to ensure the precise regulation of aroma. This research will provide a theoretical basis for the improvement of wine production technology and quality. [ABSTRACT FROM AUTHOR]

Pyocyanin (PCN, 1-hydroxy-5-methyl-phenazine) is one of the most essential virulence factors of Pseudomonas aeruginosa (PA) to cause various cytotoxic effects in long-term lung infectious diseases, however the early effect of this bacterial toxin during PA infection and subsequent autonomous immune response in host cells have not been fully understood yet. Our results display that early onset of PCN stimulates Pseudomonas aeruginosa PAO1 adhesion and invasion in A549 cells via ROS production. Non-histone nuclear protein HMGN2 is found to be involved in the regulation of PCN-induced oxidative stress by promoting intracellular ROS clearance. Mechanistically, HMGN2 facilitates nuclear translocation of transcription factor Nrf2 upon PCN stimulation and in turn elevates antioxidant gene expression. We also found that actin cytoskeleton dynamics is targeted by ROS, which is to be exploited by PAO1 for host cell internalization. HMGN2 regulates actin skeleton rearrangement in both PCN-dependent and independent manners and specifically attenuates PCN-mediated PAO1 infection via ROS elimination. These results uncover a novel link between nuclear protein HMGN2 and Nrf2-mediated cellular redox circumstance and suggest roles of HMGN2 in autonomous immune response to PA infection. [ABSTRACT FROM AUTHOR]

The tuntian system was a state-promoted system of military–agriculture, which originated in the Western Han dynasty (206 BC–9 AD). All the imperial dynasties in Chinese history adopted the practice of tuntian to cultivate and guard frontier areas as an important state policy for developing border areas and consolidating frontier defense. This paper describes the use of satellite remote sensing data to uncover an ancient canal-based tuntian system located in an oasis agricultural landscape adjacent to the ancient Kingdom of Loulan at the southern margin of the Tarim Basin. The remote sensing data examined include Chinese Gaofen-1 (GF-1) VHR imagery, Landsat-8 (LS-8) OLI data and ASTER Global Digital Elevation Model Version 2 (ASTER GDEMV2) products. The effective irrigated tuntian area was estimated to be 2800 ha and the maximum irrigated tuntian area was found to be more than 8000 ha during the area's most prosperous period. The overall spatial structure of Milan's tuntian agricultural landscape was explored using the patch–corridor–matrix model. By detailed analysis of satellite remote sensing data, this study reconstructed a 3D view of Milan's tuntian agricultural landscape in a GIS. [ABSTRACT FROM AUTHOR]

Acetyl ligation to the amino acids in a protein is an important posttranslational modification. However, in contrast to lysine acetylation, N-terminal acetylation is elusive in terms of its cellular functions. Here, we identify Nat3 as an N-terminal acetyltransferase essential for autophagy, a catabolic pathway for bulk transport and degradation of cytoplasmic components. We identify the actin cytoskeleton constituent Act1 and dynamin-like GTPase Vps1 (vacuolar protein sorting 1) as substrates for Nat3-mediated N-terminal acetylation of the first methionine. Acetylated Act1 forms actin filaments and therefore promotes the transport of Atg9 vesicles for autophagosome formation; acetylated Vps1 recruits and facilitates bundling of the SNARE (soluble N-ethylmaleimide-sensitive factor activating protein receptor) complex for autophagosome fusion with vacuoles. Abolishment of the N-terminal acetylation of Act1 and Vps1 is associated with blockage of upstream and downstream steps of the autophagy process. Therefore, our work shows that protein N-terminal acetylation plays a critical role in controlling autophagy by fine-tuning multiple steps in the process. [Display omitted] • Identification of Nat3 as an essential factor for autophagy • Nat3 is critical for autophagy through its N-terminal acetyltransferase activity • Nat3 catalyzes the N-terminal acetylation of Act1 and Vps1 • The modification of Act1 and Vps1 regulates autophagy Shen et al. report N-terminal acetylation in yeast is involved in autophagy regulation. The N-terminal acetyltransferase Nat3 plays an essential role in autophagy by modifying actin cytoskeleton constituent Act1 and dynamin-like GTPase Vps1, which regulate the upstream transport of Atg9 vesicles and downstream fusion of autophagosomes with vacuoles. [ABSTRACT FROM AUTHOR]

Abstract: The culture decline of Chaohu Lake Basin after the Han Dynasty is a remarkable archaeological phenomenon in the Jianghuai region, Anhui Province, East China. Analysis of the relevant historic records, combined with the new progress in environmental archaeological research and remote sensing data, demonstrates how the ancient culture of Chaohu Lake Basin declined after the Han Dynasty from a geoarchaeological perspective. The results show that the culture decline after the Han Dynasty may be caused by the environmental changes. The deterioration of climate conditions combined with floods, earthquakes and other natural disasters, as well as the climate background of Chinese economic and cultural center transfer, together with the north-south division of political geographic factors that led to war, all caused the ancient “Chao-Fei Channel” to decline gradually and destroyed the agricultural economic foundation of cultural development in the Chaohu Lake Basin. These also brought the decline of the development of settlements and substantial decreases in archaeological sites and burial numbers. Subsequently, the cultural development of the Chaohu Lake Basin declined. [Copyright &y& Elsevier]

The proteasome is the main proteolytic system for targeted protein degradation in the cell and is fine-tuned according to cellular needs. Here, we demonstrate that mitochondrial dysfunction and concomitant metabolic reprogramming of the tricarboxylic acid (TCA) cycle reduce the assembly and activity of the 26S proteasome. Both mitochondrial mutations in respiratory complex I and treatment with the anti-diabetic drug metformin impair 26S proteasome activity. Defective 26S assembly is reversible and can be overcome by supplementation of aspartate or pyruvate. This metabolic regulation of 26S activity involves specific regulation of proteasome assembly factors via the mTORC1 pathway. Of note, reducing 26S activity by metformin confers increased resistance toward the proteasome inhibitor bortezomib, which is reversible upon pyruvate supplementation. Our study uncovers unexpected consequences of defective mitochondrial metabolism for proteasomal protein degradation in the cell, which has important pathophysiological and therapeutic implications. • Respiratory dysfunction impairs 26S proteasome assembly and activity • Aspartate deficiency inhibits protein synthesis and 26S proteasome activity via mTORC1 • Aspartate restores 26S activity via upregulation of proteasome assembly factors • Addition of pyruvate overcomes resistance to bortezomib in respiration-deficient cells Meul et al. demonstrate reversible regulation of 26S proteasome assembly and activity by metabolic reprogramming of the TCA cycle upon impaired respiratory function. Supplementation with aspartate or pyruvate restores 26S proteasome activity via mTORC1-mediated transcriptional activation of defined proteasome assembly factors. [ABSTRACT FROM AUTHOR]

The interactions between non-starch polysaccharides alter the physicochemical properties of the mucin, therefore can affect encapsulated nutrients penetrating through the mucus layer in the gastrointestinal tract. This study explored the interactions between mucin and galactomannans (GMs) with different mannose-to-galactose ratios going through contact, diffusion, and binding stages. During contact stage, the contact angle was used to characterize the interactions between mucin and GMs, and results showed that locust bean gum (4:1) with lower molecular weight had more contact area to form more hydrogen bonds with water. At diffusion and binding stage, based on the analysis of ATR-FTIR, rheology, and fluorescence spectroscopy, more galactose side chains in guar gum (2:1) had more hydrogen donors and acceptors and more space between polysaccharides to form intermolecular hydrogen bonds with mucin, which enhanced the interactions with mucin. Molecular docking results suggested that more hydrogen bonds in the main chain and less in the side chain resulted in more availability to form intramolecular hydrogen bonds and therefore reduced the strength of the interactions with mucin. Moreover, the Transwell assay revealed that enhancing the interactions of GMs with mucin, especially hydrogen bonds, slowed down the migration of the riboflavin. The current discovery laid the groundwork for designing GMs-based delivery systems that are capable to control the duration of nutrient action on the mucus by changing the molecular properties of the polysaccharide. [Display omitted] • Three-stage interaction mechanism between mucin and GMs was discussed. • Mannose-to-galactose ratios of GMs regulate the interactions with mucin. • Interaction mechanism can control the migration behavior of riboflavin. [ABSTRACT FROM AUTHOR]

Magnesium and Mg-based alloys are promising biomaterials for orthopedic implants because of their degradability, osteogenic effects, and biocompatibility. However, the drawbacks of these materials include high hydrogen gas production, unexpected corrosion resistance, and insufficient mechanical strength duration. Surface modification can protect these biomaterials and induce osteogenesis. In this work, a SrHPO 4 coating was developed for our patented biodegradable Mg–Nd–Zn–Zr alloy (abbr. JDBM) through a chemical deposition method. The coating was characterized by in vitro immersion, ion release, and cytotoxicity tests, which showed a slower corrosion behavior and excellent cell viability. RNA sequencing of MC3T3E1 cells treated with SrHPO 4 -coated JDBM ion release test extract showed increased Tlr4 , followed by the activation of the downstream PI3K/Akt signaling pathway, causing proliferation and growth of pre-osteoblasts. An intramedullary nail (IMN) was implanted in a femoral fracture rat model. Mechanical test, radiological and histological analysis suggested that SrHPO 4 -coated JDBM has superior mechanical properties, induces more bone formation, and decreases the degradation rate compared with uncoated JDBM and the administration of TLR4 inhibitor attenuated the new bone formation for fracture healing. SrHPO 4 is a promising coating for JDBM implants, particularly for long-bone fractures. • SrHPO 4 reduces the in vivo corrosion rate of Mg–Nd–Zn–Zr implants. • Release of Sr2+ and Mg2+ ions induces a biochemical response in rat femur fracture model. • Osteogenic response is stimulated by the TLR4/PI3K/Akt signaling pathway. • Improved mechanical stability and osteogenic induction enhances fracture healing. [ABSTRACT FROM AUTHOR]