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Cardiac mononuclear phagocytic cells (Cardiac MPCs) participate in maintaining homeostasis and orchestrating cardiac responses upon injury. However, the function of specific MPC subtypes and the related cell fate commitment mechanisms remain elusive in regenerative and nonregenerative hearts due to their cellular heterogeneities. Using spatiotemporal single-cell epigenomic analysis of cardiac MPCs in regenerative (P1) and nonregenerative (P10) mouse hearts after injury, we found that P1 hearts accumulate reparative Arg1+ macrophages, while proinflammatory S100a9+Ly6c+ monocytes are uniquely abundant during nonregenerative remodeling. Moreover, blocking chemokine CXCR2 to inhibit the specification of the S100a9+Ly6c+-biased inflammatory fate in P10 hearts resulted in elevated wound repair responses and marked improvements in cardiac function after injury. Single-cell RNA-Seq further confirmed an increased Arg1+ macrophage subpopulation after CXCR2 blockade, which was accomplished by increased expression of wound repair-related genes and reduced expression of proinflammatory genes. Collectively, our findings provide instructive insights into the molecular mechanisms underlying the function and fate specification of heterogeneous MPCs during cardiac repair and identify potential therapeutic targets for myocardial infarction.

The macroalgal blooms of floating brown algae Sargassum horneri are increasing in the Yellow Sea and East China Sea during the past few years. However, the annual pattern of Sargassum bloom is not well characterized. To study the developing pattern and explore the impacts from hydro-meteorologic environment, high resolution satellite imageries were used to monitor the distribution, coverage and drifting of the pelagic Sargassum rafts in the Yellow Sea and East China Sea from September 2019 to August 2020. Sargassum blooms were detected from October 2019 to June 2020 and presented two successive drifting paths that both initiated from around 37°N. The first path spanned smaller spatial scale and shorter period, starting with a bloom of 3 km 2 distribution area near the eastern tip of Shandong Peninsula in late October 2019 and drifted southwards, hit the Pyropia aquaculture area in early January 2020, then vanished in the northwest of East China Sea (ca. 32°N) around end of January. The second path began with a large distribution area of 23 000 km 2 east of 123°E in late January 2020, firstly moved southwards in the central Yellow Sea and northern East China Sea (north of 29°N) till late April, then turned northwards with monsoon wind and vanished from late June to August. The mean sea surface temperature of 8°C to 20°C in the Sargassum bloom areas corresponded to in situ observed temperature range for vegetative growth and floating of S. horneri . There was no observed floating Sargassum blooms during July through September in the Yellow Sea and East China Sea. The results indicate that floating S. horneri is unable to complete life cycle in the Yellow Sea and East China Sea, and provide insights to the future management of Sargassum blooms. Further studies are needed to validate the pattern and source of annual Sargassum bloom in the Yellow Sea and East China Sea.

Gastrulation represents a crucial stage in embryonic development and is tightly controlled by a complex network involving epigenetic reprogramming. However, the molecular coordination among distinct epigenetic layers entailing the progressive restriction of lineage potency remains unclear. Here, we present a multi-omics map of H3K27ac and H3K4me1 single-cell ChIP-seq profiles of mouse embryos collected at six sequential time points. Significant epigenetic priming, as reflected by H3K27ac signals, is evident, yet asynchronous cell fate commitment of each germ layer at distinct histone modification levels are observed. Integrated scRNA-seq and single-cell ChIP-seq analysis unveil a “time lag” transition pattern between enhancer activation and gene expression during germ-layer specification. Notably, by utilizing the H3K27ac and H3K4me1 co-marked active enhancers, we construct a gene regulatory network centered on pivotal transcription factors, highlighting the potential critical role of Cdkn1c in mesoderm lineage specification. Together, our study broadens the current understanding of intricate epigenetic regulatory networks governing mouse gastrulation and sheds light on their relevance to congenital diseases.

Greenhouse pesticide application often suffers from low droplet deposition uniformity and health risks to operators. A self-propelled overhead rail air-assisted sprayer has been designed. The mathematical model based on droplet movement and the DPM are used to analyze the equipment’s working principle. Deposition surfaces at 0.4, 0.5, 0.6, and 0.7 m were used to examine the effects of travel speed, external airflow, and spray angle on droplet deposition uniformity. Through one-way analysis of variance, all variables reached a significant level (p < 0.001). Simulation results identified the optimal operating parameters: travel speed of 0.3 m/s, external air-flow velocity of 0.3 m/s, and spray angle of 5°, resulting in droplet deposition densities of 719, 586, 700, and 839 droplets/cm2, with a coefficient of variation of 14.57%. The sediment variation coefficients of both the on-site test results and the simulation results were within 10%, which proved the reliability of the numerical simulation. In conclusion, the device proposed in this study effectively enables targeted fog spraying for multi-layer crops in greenhouses, significantly improving pesticide utilization, reducing application costs, and minimizing environmental pollution. It offers reliable technical support for greenhouse pest control operations.

Since 2015, green tides with Ulva prolifera as the dominant species in the Qinhuangdao coastal waters have continued to occur. In this study, the relationship between green tides in Qinhuangdao and the Yellow Sea (setting sites in Rudong and Qingdao) was evaluated by genetic analyses of U. prolifera . Single nucleotide polymorphism (SNP) markers were used to analyze genetic diversity and genetic relationships among groups. Genetic differentiation was lower among floating U. prolifera populations in Rudong and Qingdao than in Qinhuangdao. The floating U. prolifera population had higher genetic diversity and polymorphism levels in Qingdao and Rudong than in Qinhuangdao. Physiological experiments showed that the growth rate and net buoyancy of floating U. prolifera were highest in Qinhuangdao and Qingdao, respectively, under the same environmental conditions (temperature and light). Overall, these findings showed that U. prolifera populations in the Qinhuangdao and Yellow Sea green tides (Rudong and Qingdao) differ significantly at the molecular and physiological levels. Therefore, the Qinhuangdao green tide is not correlated with the Yellow Sea green tide and has a different origin and development mode. This study provides insight into the mechanism underlying green tide blooms in coastal waters of China.

The data of field surveys during 2009 to 2018 was analyzed to understand the seasonality and inter-annual variability of the floating Ulva and Sargassum in the Subei Shoal, the southwestern Yellow Sea of China on decadal scale. The floating Ulva biomass was consistently originated from the central region of the Subei Shoal in middle to late April, increased rapidly, drifted and extended into the offshore water in May and June. The average floating Ulva biomass in the shoal generally increased over the years with evident inter-annual fluctuations. In contrast, pelagic Sargassum was accumulated in the Subei Shoal and formed the spring bloom only in 2013, 2017 and 2018, and the biomass was higher than the co-occurring Ulva during the survey in these three years. Compared to the raft-origin floating Ulva , genesis and development of the pelagic Sargassum was distinct. Based on the current research, the Sargassum biomass was exotic and often initiated in the offshore water in March, and intruded into the shoal in April and May. The analysis on the environmental parameters was inconclusive since multiple anthropogenic and non-indigenous factors could influence the green tides in this region. Further research covering both the East China Sea and the Yellow Sea is needed to trace the origin of the floating Sargassum and to understand the interactions between these two co-occurring seaweeds.

Investigating the spatiotemporal variability of biogeochemical processes and ecological responses under multiple physical controls in shelf seas is of great importance for obtaining an in-depth understanding of marine ecosystem. Based on a compiled data set of historical observations and remote sensing data, the spatiotemporal variability and heterogeneity of physical-biogeochemical processes in the semi-enclosed South Yellow Sea (SYS) are investigated, and the intrinsic connectivity among different subregions and the associated mechanisms are examined. The results show that the seasonal alternation between southward transport in cold seasons and upwelling-induced vertical delivery in warm seasons is the primary physical control of the biogeochemical processes and primary production off Shidao and in the area adjacent to the Haizhou Bay. The northeastward expansion of coastal waters in the Subei Shoal constitutes an important physical driver for the offshore transport of Ulva prolifera in summer. Stratification significantly affects the biogeochemical processes in the Yellow Sea Cold Water Mass (YSCWM)-dominated area during warm seasons, and nutrients can accumulate in bottom waters from spring to autumn, making the Yellow Sea Cold Water Mass (YSCWM) be an important nutrient pool. Upwelling around the YSCWM boundary in the stratified season leads to consistency among the high chlorophyll a (Chl a ) area, high primary productivity region and low-temperature upwelling zone. During cold seasons, the interactions of the southward cold waters in the western nearshore area and the northward warm waters in the central region lead to an “S”-shaped front in the SYS. In summer, upwelling can extract nutrients from the YSCWM; thus, the biogeochemical-ecological processes inside the cold-water mass and in the frontal zone are well connected via upwelling, and three typical physical-biogeochemical coupling regions are generated, namely, the Shidao coast, the area beyond the Haizhou Bay and the area off the Subei Shoal. This work refines and integrates studies on regional oceanography in the SYS and provides a comprehensive and systematic framework of physical-biogeochemical-ecological processes.

The hot tensile deformation and fracture mechanisms of a Ti-5Al-5Mo-5V-1Cr-1Fe alloy with bimodal and lamellar microstructures were investigated by in situ tensile tests under scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The results show that the main slip deformation modes are prismatic slip (11¯00<112¯0>) and pyramidal slip (11¯01<112¯0>) under tension at 350 °C. In the bimodal microstructure, several parallel slip bands (SBs) first form within the primary α (αP) phase. As the strain increases, the number of SBs in the αP phase increases significantly and multislip systems are activated to help further coordinate the increasing deformation. Consequently, the microcracks nucleate and generally propagate along the SBs in the αP phase. The direction of propagation of the cracks deflects significantly when it crosses the αP/β interface, resulting in a tortuous crack path. In the lamellar microstructure, many dislocations pile up at the coarse-lath α (αL) phase near the grain boundaries (GBs) due to the strong fencing effect thereof. As a result, SBs develop first; then, microcracks nucleate at the αL phase boundary. During propagation, the cracks tend to propagate along the GB and thus lead to the intergranular fracture of the lamellar microstructure.

Background: Aneurysm wall enhancement (AWE) in high-resolution magnetic resonance imaging (HR-MRI) has emerged as a new imaging biomarker of intracranial aneurysm instability. Objective: To determine a standard method of AWE quantification for predicting fusiform intracranial aneurysms (FIAs) stability by comparing the sensitivity of each parameter in identifying symptomatic FIAs. The predictors of AWE and FIA types were also identified. Methods: We retrospectively analyzed consecutive fusiform aneurysm patients who underwent HR-MRI from two centers. The aneurysm-to-pituitary stalk contrast ratio (CRstalk), aneurysm enhancement ratio, and aneurysm enhancement index were extracted, and their sensitivities in discriminating aneurysm symptoms were compared using the receiver-operating characteristic curve. Morphological parameters of fusiform aneurysm were extracted based on 3D vessel model. Uni- and multivariate analyses of related predictors for AWE, CRstalk, and FIA types were performed, respectively. Results: Overall, 117 patients (mean age, 53.3 ± 11.7 years; male, 75.2%) with 117 FIAs underwent HR-MRI were included. CRstalk with the maximum signal intensity (CRstalk-max) had the highest sensitivity in identifying symptomatic FIAs with an area under the curve value (0.697) and a cut-off value of 0.90. The independent predictors of AWE were aneurysm symptoms [(odds ratio) OR = 3.754, p = 0.003], aspirin use (OR = 0.248, p = 0.037), and the maximum diameter of the cross-section (OR = 1.171, p = 0.043). The independent predictors of CRstalk-max were aneurysm symptoms (OR = 1.289, p = 0.003) and posterior circulation aneurysm (OR = 1.314, p = 0.001). Transitional-type showed higher rates of hypertension and mural thrombus over both dolichoectatic- and fusiform-type FIAs. Conclusion: CRstalk-max may be the most reliable parameter to quantify AWE to distinguish symptomatic FIAs. It also has the potential to identify unstable FIAs. Several factors contribute to the complex pathophysiology of FIAs and need further validation in a larger cohort.

The waters near the Antarctic Peninsula have always been a study hot spot because of their variable and unique oceanographic conditions. To determine the distribution and possible influencing factors on phytoplankton size and abundance near the Antarctic Peninsula, a large-scale survey was conducted during the austral summer of 2018. Samples were collected in 27 stations located in the Drake Passage (DP), South Shetland Islands (SSI), and South Orkney Islands (SOI). Phytoplankton communities were described using chlorophyll a (Chl a ), flow cytometry and light microscopy to cover a size range from pico- to microphytoplankton. Nanophytoplankton, especially small nanophytoplankton (2–6 µm) with abundance ranging from 0.66 × 10 3 cells/mL to 8.46 × 10 3 cells/mL, was predominant throughout the study area. Among different regions, there was an obvious size shift. The proportion of picophytoplankton near the Elephant Island (EI) and DP was higher than other regions, and larger cells were found mainly in east of SOI. The distribution of phytoplankton abundance detected by flow cytometry was not completely consistent with Chl a concentrations due to the contribution of larger cells to Chl a . Possible influencing factors on the phytoplankton size distribution were discussed. The properties of water masses such as temperature and salinity can influence the phytoplankton size distribution. Correlation analysis revealed that only picophytoplankton is significantly correlated with salinity. Light and Fe availability might affect phytoplankton abundance and size distribution especially near the waters of SSI and EI in this study. It was also speculated that the abundance of cryptophytes is possibly related to ice melting.