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Abstract Kiwifruit is an economically and nutritionally important horticultural fruit crop worldwide. The genomic data of several kiwifruit species have been released, providing an unprecedented opportunity for pan-genome analysis to comprehensively investigate the inter- and intra-species genetic diversity and facilitate utilization for kiwifruit breeding. Here, we generated a kiwifruit super pan-genome using 15 high-quality assemblies of eight Actinidia species. For gene-based pan-genome, a total of 61,465 gene families were identified, and the softcore and dispensable genes were enriched in biological processes like response to endogenous stimulus, response to hormone and cell wall organization or biogenesis. Then, structural variations (SVs) against A. chinensis ‘Donghong’ were identified and then used to construct a graph-based genome. Further population-scale SVs based on resequencing data from 112 individuals of 20 species revealed extensive SVs which probably contributed to the phenotypic diversity among the Actinidia species. SV hotspot regions were found contributed to environmental adaptation. Furthermore, we systematically identified resistance gene analogs (RGAs) in the 15 assemblies and generated a pan-RGA dataset to reveal the diversity of genes potentially involved in disease resistance in Actinidia. The pan-genomic data obtained here is useful for evolutionary and functional genomic studies in Actinidia, and facilitates breeding design.

Surface nano-modification has emerged as an effective strategy to enhance osseointegration of titanium (Ti) implants. Despite its promise, rational optimization of surface nanomorphology for ameliorated osseointegration remains a significant challenge. Our research pioneering developed a one-step alkali etching technique to produce a gradient nanowire coating with continuously varied dimensions on Ti surfaces, which was subsequently served as a versatile platform for high-throughput screening of optimal dimensions to enhance osseointegration. The results showed that macrophages (MФs) that mainly governed the initial inflammatory reaction exhibited a polarization tendency towards pro-healing M2 phenotype with decreased nanowire dimension due to nanomorphology-mediated focal adhesion formation and activation of its downstream signaling pathways (typically PI3K-Akt). Simultaneously, small-sized nanowires with diameter of 5.63–14.25 nm and inter-spacing of 29.42–57.97 nm were conductive to angiogenesis of endothelial cells (ECs) and osteogenesis of bone marrow mesenchymal stem cells (BMSCs), which may share similar mechanisms of MФs. The in vivo results well corroborated these in vitro observations. The knowledge gained from the present work not only advance our understanding of the interaction between surface morphology and cells, but also potentially pave the way for efficient and cost-effective design of advanced biomaterial surfaces for better osseointegration.

Antibiotic resistance genes (ARGs) may have significant impacts on human health and ecosystems. Airborne ARGs are reportedly widely distributed across inland cities, but little is known about their abundance in marine atmospheres. Here, we report observations of ambient ARGs during a cruise over the marginal seas of the Bohai Sea and Yellow Sea and compare them with ARGs in the coastal atmosphere. We characterized the ARGs in terms of their abundance, occurrence, degradation, and risk in the marine and coastal atmospheres. Using Na+ and Ca2+ as indicators of marine and continental aerosol sources, respectively, we quantified the mutual transport of airborne ARGs. Our results revealed that the airborne ARG abundances and the number of ARG types increased concomitantly with the mass concentrations of particulate matter because of the accumulation effect, but the ratios of ARG abundance/particulate matter concentration gradually decreased. The inconsistent trend suggested that the reduction in airborne ARGs was greater than their increase with bacterial reproduction during their accumulation and transport in the atmosphere. In addition, the number of ARG types in marine aerosols was greater than that in coastal aerosols. However, the airborne ARG abundance in marine aerosols was greater than that in clean coastal aerosols but not in polluted coastal aerosols. Some ARG types detected in marine aerosols were significantly and positively correlated with wind speed and relative humidity, implying that they may be derived from marine emissions, whereas the other ARGs are likely derived from long-range continental transport. Sea-derived airborne ARGs serve as important sources in coastal aerosols, but their contributions decrease with increasing air pollution levels. Our findings highlight the complex role of marine aerosols as both potential sources and reservoirs of airborne ARGs and highlight the critical importance of investigating the transport dynamics and variation mechanism during the long-range transport of ARGs.

Abstract The physical killing of bacteria based on surface topography has attracted much attention due to the sustainable and safe prevention of biofilm formation. However, the antibacterial efficiency of biomedical implants derived solely from nanostructures or microstructures is insufficient to combat bacteria against common infections, such as methicillin‐resistant Staphylococcus aureus with thick cell walls. Herein, photothermal therapy is carried out in the presence of nanorod arrays to mitigate infection of biomedical implants. Different from traditional photothermal therapy relying on a photosensitizer, the photothermal effect is mediated by light traps rendered by the nanorod arrays, and consequently, the photosensitizer is not needed. Finite element simulations and experiments are performed to elucidate the light‐to‐thermal conversion mechanism. This photothermal platform, in conjunction with thermosensitive nitric oxide therapy, is applied to treat titanium implant infection. The nanostructure‐mediated photothermal effect destroys bacterial cell walls by inhibiting peptidoglycan synthesis and increasing the membrane permeability by affecting fatty acid synthesis. Furthermore, the nanorods synergistically puncture the bacterial membrane easily as demonstrated by experiments and transcriptome analysis. The results provide insights into the development of efficient antibacterial treatment of implants by combining nanostructures and photothermal therapy.

Abstract Diabetes, a metabolic disorder characterized by hyperglycemia, underscores the importance of normal pancreatic β‐cell development and function in maintaining glucose homeostasis. Poly(A)‐specific ribonuclease (PARN) serves as the principal regulator of messenger RNA (mRNA) stability, yet its specific role in pancreatic β cells remains unclear. This study utilizes mice with targeted PARN deficiency in β cells to elucidate this role. Notably, Parn conditional knockout mice present unaltered β‐cell development and insulin sensitivity but reduced glucose‐stimulated insulin secretion (GSIS). The observed outcomes are corroborated in NIT‐1 cells. Furthermore, transcriptomic analyses reveal aberrant mRNA expression of genes crucial for insulin secretion in PARN‐deficient β cells. Insights from linear amplification of complementary DNA ends and sequencing and coimmunoprecipitation experiments reveal an interaction between PARN and polypyrimidine tract‐binding protein 1 (PTBP1), regulating the RNA stability of solute carrier family 30, member 8 (Slc30a8) and carbohydrate sulfotransferase 3 (Chst3). Interference with either PARN or PTBP1 disrupts this stability. These data indicate that PARN deficiency hampers GSIS and insulin maturation by destabilizing Slc30a8 and Chst3 RNAs. These findings provide compelling evidence indicating that PARN is a potential therapeutic target for enhancing insulin maturation and secretion.

Abstract Background Müllerian adenosarcoma, a rare malignancy, presents diagnostic and therapeutic challenges. In this study, we conducted an analysis of the clinicopathological characteristics of 22 adenosarcomas, with a particular focus on screening for DICER1 hot mutations. Methods The cohort consisted of patients with adenosarcoma who were registered at the West China Second Hospital between the years 2020 and June 2022. Sanger sequencing was employed to screen for somatic Hotspot mutations in the RNase IIIb domain of DICER1 in the 22 adenosarcomas. Results Only one patient exhibited a DICER1 mutation that was not a DICER1 Hotspot mutation. Among the 22 patients, all underwent total hysterectomy with bilateral salpingo-oophorectomy, and 14 out of these 22 patients received adjuvant treatment. Conclusion In summary, our study of 22 Müllerian adenosarcomas focused on the clinicopathological features and the presence of DICER1 Hotspot mutations. Although our findings did not reveal any DICER1 mutations in the studied samples, this negative result provides valuable information for the field by narrowing down the genetic landscape of adenosarcomas and highlighting the need for further research into alternative molecular pathways driving this malignancy.

Oxalic acid is the most abundant low-molecular-weight dicarboxylic acid in the atmosphere, and it plays a crucial role in the formation of new particles and cloud condensation nuclei. However, most observational studies have focused on particulate oxalate, leaving a significant knowledge gap on oxalic acid vapor. This study investigated the concentrations and formation of oxalic acid vapor and oxalate in PM2.5 at a rural tropical coastal island site in south China across different seasons, based on semi-continuous measurements using an Ambient Ion Monitor-Ion Chromatograph (AIM-IC) system. We replaced the default 25 μL sampling loop on the AIM-IC with a 250 μL loop, improving the ability to distinguish the signal of oxalic acid vapor from noise. The data revealed clear seasonal patterns in the dependent daytime and nighttime formation of oxalic acid vapor, benefiting from high signal-to-noise ratios. Specifically, concentrations were 0.059 ± 0.15 μg m−3 in February and April 2023, exhibiting consistent diurnal variations similar to those of O3, likely driven by photochemical reactions. These values decreased to 0.021 ± 0.07 μg m−3 in November and December 2023, with higher nighttime concentrations likely related to dark chemistry processes, amplified by accumulation due to low mixing layer height. The concentrations of oxalate in PM2.5 were comparable to those of oxalic acid vapor, but exhibited (3–7)-day variations, superimposed on diurnal fluctuations to varying degrees. Additionally, thermodynamic equilibrium calculations were performed on the coastal data, and independent size distributions of particulate oxalate in the upwind marine atmosphere were analyzed to support the findings.

Abstract In coastal seas, the role of atmospheric deposition and river runoff in dissolved organic phosphorus (DOP) utilization is not well understood. Here, we address this knowledge gap by combining microcosm experiments with a global approach considering the relationship between the activity of alkaline phosphatases and changes in phytoplankton biomass in relation to the concentration of dissolved inorganic phosphorus (DIP). Our results suggest that the addition of aerosols and riverine water stimulate the biological utilization of DOP in coastal seas primarily by depleting DIP due to increasing nitrogen concentrations, which enhances phytoplankton growth. This “Anthropogenic Nitrogen Pump” was therefore identified to make DOP an important source of phosphorus for phytoplankton in coastal seas but only when the ratio of chlorophyll a to DIP [Log10 (Chl a / DIP)] is larger than 1.20. Our study therefore suggests that anthropogenic nitrogen input might contribute to the phosphorus cycle in coastal seas.

Local adaptation has been proven to be common in plants and extensively studied, from increasing plant yields to predicting species responses to the future changing climate. Compared to main crops and forest trees, however, investigations into the local adaptation of fruit trees across current and future climatic landscapes are still lacking. With the explosion of large-scale genomic data, landscape genomics has emerged as a new approach to identify candidate loci that are related to environmental variations (i.e., genotype-environment associations or GEA), while allowing for downstream analyses such as the calculation of adaptive indices and genetic offsets, which can be used to predict spatial-temporal shifts of populations in response to future environmental change. Here, by summarizing the cutting-edge methods for investigating species' local adaptation as well as evaluating the genetic offsets based on the current genotype-environment association, we call for more efforts on elucidating genomic and molecular underpinnings of local adaptation of fruit trees and forecasting the possible maladaptation under rapid climate change. In summary, the study of local adaptation in fruit trees is important for ensuring long-term sustainability and productivity. The emergence of landscape genomics has great potential to advance our understanding of the genomic and molecular mechanisms underlying local adaptation and to predict responses to environmental change.

Here, we compared the concentrations of cloud condensation nuclei (CCN) and particle number size distributions (PNSDs) measured during the transient period from the winter to the summer East Asian monsoon in 2021 with those in 2014 to explore possible responses to how CCN responds to upwind continental air pollutant mitigation and marine traffic fuel sulfur content (FSC) regulation over the northwest Pacific Ocean (NWPO). We also employed the Positive Matrix Factorization (PMF) analysis to apportion concentrations of CCN (Nccn) to different sources in order to quantify its source-specified responses to mitigation of air pollution during the transient period. Our results showed that (1) upwind continental mitigation likely reduced Nccn by approximately 200 cm−3 and 400 cm−3 at 0.2% and 0.4% supersaturation (SS), respectively, in the marine background atmosphere over the NWPO; (2) FSC regulation resulted in a decrease in Nccn at 0.4% SS by about 50 cm−3 and was nearly negligible at 0.2% SS over the NWPO. Additionally, a PMF-resolved factor, characterized by a dominant nucleation mode, was present only in 2014 and disappeared in 2021, likely due to the reduction. This estimation, however, suffered from uncertainties since seasonal changes were hard to be deducted accurately. PMF-resolved factors accurately represented Nccn in 80–90% of cases, but this accuracy was not observed in the remaining cases. Finally, an integrated analysis of satellite-derived cloud parameters and ship-based measurements indicated that the reduced Nccn over the NWPO might be co-limited with meteorological factors in forming cloud droplets during the transient period.

(1) Background: SMARCA4-deficient undifferentiated uterine sarcoma (SDUS) is a rare and aggressive cancer that urgently requires novel therapeutic strategies. Despite the proven efficacy of immunotherapy in various cancer types, its application in SDUS remains largely unexplored. This study aims to investigate the immune microenvironment of SDUS to evaluate the feasibility of utilizing immunotherapy. (2) Methods: Multiplex immunofluorescence (mIF) was employed to examine the immune microenvironment in two cases of SDUS in comparison to other subtypes of endometrial stromal sarcomas (ESSs). This research involved a comprehensive evaluation of immune cell infiltration, cellular interactions, and spatial organization within the tumor immune microenvironment (TiME). Statistical analysis was performed to assess differences in immune cell densities and interactions between SDUS and other ESSs. (3) Results: SDUS exhibited a significantly higher density of cytotoxic T lymphocytes (CTLs), T helper (Th) cells, B cells, and macrophages compared to other ESSs. Notable cellular interactions included Th–CTL and Th–B cell interactions, which were more prominent in SDUS. The spatial analysis revealed distinct immune niches characterized by lymphocyte aggregation and a vascular-rich environment, suggesting an active and engaged immune microenvironment in SDUS. (4) Conclusions: The results suggest that SDUS exhibits a highly immunogenic TiME, characterized by substantial lymphocyte infiltration and dynamic cellular interactions. These findings highlight the potential of immunotherapy as an effective treatment approach for SDUS. However, given the small number of samples evaluated, these conclusions should be drawn with caution. This study underscores the importance of additional investigation into immune-targeted therapies for this challenging cancer subtype, with a larger sample size to validate and expand upon these preliminary findings.

The study determined the impacts of dietary fermented residues’ (FBR) inclusion on growth, nutrient utilization, carcass characteristics, and meat properties in fattening pigs. Seventy-two robust pigs were randomly assigned to two experimental groups (Duroc × Landrace × Yorkshire, thirty-six pigs each). Each group was subjected to a 52-day trial, during which they received either a corn–soybean meal-based diet or diet enhanced with a 10% addition of FBR. Consequently, adding 10% FBR caused a significant decrease in the digestive utilization of crude dietary components in fattening pigs (p < 0.05) but showed no significant impact on the growth performance. Additionally, FBR inclusion increased the marbling scores (p < 0.05) and total antioxidant functions (p < 0.05) of muscle tissues, indicating improved meat quality. Gender affected backfat depth, with barrows showing thicker backfat depth. In conclusion, dietary supplementation with 10% FBR in finishing pigs influenced the meat quality by improving the marbling score and antioxidant performance while reducing digestibility without compromising growth performance.

Spermatogonial stem cells (SSCs) are essential for continuous spermatogenesis and male fertility. The underlying mechanisms of alternative splicing (AS) in mouse SSCs are still largely unclear. We demonstrated that SRSF1 is essential for gene expression and splicing in mouse SSCs. Crosslinking immunoprecipitation and sequencing data revealed that spermatogonia-related genes (e.g. Plzf, Id4, Setdb1, Stra8, Tial1/Tiar, Bcas2, Ddx5, Srsf10, Uhrf1, and Bud31) were bound by SRSF1 in the mouse testes. Specific deletion of Srsf1 in mouse germ cells impairs homing of precursor SSCs leading to male infertility. Whole-mount staining data showed the absence of germ cells in the testes of adult conditional knockout (cKO) mice, which indicates Sertoli cell-only syndrome in cKO mice. The expression of spermatogonia-related genes (e.g. Gfra1, Pou5f1, Plzf, Dnd1, Stra8, and Taf4b) was significantly reduced in the testes of cKO mice. Moreover, multiomics analysis suggests that SRSF1 may affect survival of spermatogonia by directly binding and regulating Tial1/Tiar expression through AS. In addition, immunoprecipitation mass spectrometry and co-immunoprecipitation data showed that SRSF1 interacts with RNA splicing-related proteins (e.g. SART1, RBM15, and SRSF10). Collectively, our data reveal the critical role of SRSF1 in spermatogonia survival, which may provide a framework to elucidate the molecular mechanisms of the posttranscriptional network underlying homing of precursor SSCs.

Abstract Background Granulosa cell proliferation and differentiation are essential for follicle development. Breast cancer amplified sequence 2 (BCAS2) is necessary for spermatogenesis, oocyte development, and maintaining the genome integrity of early embryos in mice. However, the function of BCAS2 in granulosa cells is still unknown. Results We show that conditional disruption of Bcas2 in granulosa cells caused follicle development failure; the ratio of the positive cells of the cell proliferation markers PCNA and Ki67 were unchanged in granulosa cells. Specific deletion of Bcas2 caused a decrease in the BrdU-positive cell ratio, cell cycle arrest, DNA damage, and an increase in apoptosis in granulosa cells, and RPA1 was abnormally stained in granulosa cells. RNA-seq results revealed that knockout of Bcas2 results in unusual expression of cellular senescence genes. BCAS2 participated in the PRP19 complex to mediate alternative splicing (AS) of E2f3 and Flt3l mRNA to inhibit the cell cycle. Knockout of Bcas2 resulted in a significant decrease in the ratio of BrdU-positive cells in the human granulosa-like tumour (KGN) cell line. Conclusions Our results suggest that BCAS2 may influence the proliferation and survival of granulosa cells through regulating pre-mRNA splicing of E2f3 and Flt3l by forming the splicing complex with CDC5L and PRP19.

Abstract How does SARS-CoV-2 cause lung microenvironment disturbance and inflammatory storm is still obscure. We here performed the single-cell transcriptome sequencing from lung, blood, and bone marrow of two dead COVID-19 patients and detected the cellular communication among them. Our results demonstrated that SARS-CoV-2 infection increase the frequency of cellular communication between alveolar type I cells (AT1) or alveolar type II cells (AT2) and myeloid cells triggering immune activation and inflammation microenvironment and then induce the disorder of fibroblasts, club, and ciliated cells, which may cause increased pulmonary fibrosis and mucus accumulation. Further study showed that the increase of T cells in the lungs may be mainly recruited by myeloid cells through ligands/receptors (e.g., ANXA1/FPR1, C5AR1/RPS19, and CCL5/CCR1). Interestingly, we also found that certain ligands/receptors (e.g., ANXA1/FPR1, CD74/COPA, CXCLs/CXCRs, ALOX5/ALOX5AP, CCL5/CCR1) are significantly activated and shared among lungs, blood and bone marrow of COVID-19 patients, implying that the dysregulation of ligands/receptors may lead to immune cell’s activation, migration, and the inflammatory storm in different tissues of COVID-19 patients. Collectively, our study revealed a possible mechanism by which the disorder of cell communication caused by SARS-CoV-2 infection results in the lung inflammatory microenvironment and systemic immune responses across tissues in COVID-19 patients.

Abstract Background Ovarian folliculogenesis is a tightly regulated process leading to the formation of functional oocytes and involving successive quality control mechanisms that monitor chromosomal DNA integrity and meiotic recombination. A number of factors and mechanisms have been suggested to be involved in folliculogenesis and associated with premature ovarian insufficiency, including abnormal alternative splicing (AS) of pre-mRNAs. Serine/arginine-rich splicing factor 1 (SRSF1; previously SF2/ASF) is a pivotal posttranscriptional regulator of gene expression in various biological processes. However, the physiological roles and mechanism of SRSF1 action in mouse early-stage oocytes remain elusive. Here, we show that SRSF1 is essential for primordial follicle formation and number determination during meiotic prophase I. Results The conditional knockout (cKO) of Srsf1 in mouse oocytes impairs primordial follicle formation and leads to primary ovarian insufficiency (POI). Oocyte-specific genes that regulate primordial follicle formation (e.g., Lhx8, Nobox, Sohlh1, Sohlh2, Figla, Kit, Jag1, and Rac1) are suppressed in newborn Stra8-GFPCre Srsf1 Fl/Fl mouse ovaries. However, meiotic defects are the leading cause of abnormal primordial follicle formation. Immunofluorescence analyses suggest that failed synapsis and an inability to undergo recombination result in fewer homologous DNA crossovers (COs) in the Srsf1 cKO mouse ovaries. Moreover, SRSF1 directly binds and regulates the expression of the POI-related genes Six6os1 and Msh5 via AS to implement the meiotic prophase I program. Conclusions Altogether, our data reveal the critical role of an SRSF1-mediated posttranscriptional regulatory mechanism in the mouse oocyte meiotic prophase I program, providing a framework to elucidate the molecular mechanisms of the posttranscriptional network underlying primordial follicle formation.

The generation and transport process of bombardment ions and the sputtering process of ions on target are important parts to realize double glow plasma metallization. In this paper, on the basis of the glow discharge theory and COMSOL Multiphysics software, a typical double glow plasma metalizing device was modeled, and the energy range of bombardment ions was analyzed. Combined with the classical scattering theory and Monte Carlo method, SRIM software was used to simulate the sputtering process of Ar+ on multiple metal targets. The results show that the position of sputtering atom is concentrated near the incident position of metal target, forming a circular sputtering crater. The energy of sputtered atoms is within 20 eV. With the increase of incident ion energy, some sputtered atoms with high energy and large angle appear. The sputtering yield increases with the increase of the electron filling degree of the d shell layer of target atom, and the sputtering yield mainly comes from the low-energy recoil atoms. The larger sputtering yield means that the more low energy recoil atoms, the more dispersed energy transfer and the lower sputtering atom energy.

Abstract Heatwaves are strongly associated with temperature distributions, but the mechanisms by which distributions are influenced by climate change remains unclear. Comparing simulations from a high‐spatial resolution Community Earth System Model (CESM‐HR) with those from low‐resolution models, we identify substantial improvements by CESM‐HR in reproducing observed Northern Hemisphere summer temperature skewness, as well as the frequency, intensity, persistence, and total heatwave days. Temperature skewness is strongly linked to land‐atmosphere interactions and atmospheric circulation. Under global warming projections, some regions exhibit enhanced temperature skewness, along with more frequent and persistent heatwaves of greater intensity. We find that in energy‐limited regimes, such as India, negative skewness in latent heat flux facilitates large positive skewness in sensible heat flux, which modulates near‐surface air temperatures. Skewness differences of latent and sensible heat fluxes are amplified under global warming, increasing the temperature skewness. We find that this contrasting flux mechanism is active in several heatwave‐prone regions.

Abstract Background As one of the largest transcription factor families in plants, AP2/ERF gene superfamily plays important roles in plant growth, development, fruit ripening and biotic and abiotic stress responses. Despite the great progress has been made in kiwifruit genomic studies, little research has been conducted on the AP2/ERF genes of kiwifruit. The increasing kiwifruit genome resources allowed us to reveal the tissue expression profiles of AP2/ERF genes in kiwifruit on a genome-wide basis. Results In present study, a total of 158 AP2/ERF genes in A. eriantha were identified. All genes can be mapped on the 29 chromosomes. Phylogenetic analysis divided them into four main subfamilies based on the complete protein sequences. Additionally, our results revealed that the same subfamilies contained similar gene structures and conserved motifs. Ka/Ks calculation indicated that AP2/ERF gene family was undergoing a strong purifying selection and the evolutionary rates were slow. RNA-seq showed that the AP2/ERF genes were expressed differently in different flower development stages and 56 genes were considered as DEGs among three contrasts. Moreover, qRT-PCR suggested partial genes showed significant expressions as well, suggesting they could be key regulators in flower development in A. eriantha. In addition, two genes (AeAP2/ERF061, AeAP2/ERF067) had abundant transcription level based on transcriptomes, implying that they may play a crucial role in plant flower development regulation and flower tissue forming. Conclusions We identified AP2/ERF genes and demonstrated their gene structures, conserved motifs, and phylogeny relationships of AP2/ERF genes in two related species of kiwifruit, A. eriantha and A. chinensis, and their potential roles in flower development in A. eriantha. Such information would lay the foundation for further functional identification of AP2/ERF genes involved in kiwifruit flower development.

Zn-xNb (x=0, 0.5, 1, 3, 5, 10%) composites were prepared by vacuum heating-press sintering process with Zn and Nb powders as raw materials. The surface morphology and phases of the composites were characterized. The effects of Nb addition on the mechanical properties, corrosion degradation behavior, and cytocompatibility of the composites were investigated. The results show that the Nb particles are distributed in the Zn matrix in a lamellar shape. With the increase of Nb content, the compressive yield strength of the composite increases first and then decreases, and Zn-0.5Nb shows the best performance. The increase of Nb content accelerates the degradation of the composites. Compared with pure Zn, the samples with high Nb content show better cytocompatibility, probably owing to the addition of Nb reducing the release of Zn2+.

In this article, we mainly investigated the effects of different simvastatin concentrations on the biological behavior of senescent macrophages and the immune microenvironment mediated by them on osteogenic and angiogenic functions. The feasibility of loading simvastatin on titanium surfaces to mediate the function of senescent macrophages was also explored. The results show that when the concentration of the drug was 0.1 μmol/L, it promoted the proliferation of macrophages and polarized them to pro-healing M2 phenotype, which is beneficial for macrophages to create an immune microenvironment promoting osteogenesis and angiogenesis. The chitosan/gelatin coating constructed on titanium surface could load and release simvastatin, promoting the viability and proliferation of senescent macrophages.

Abstract The current kiwifruit industry is mainly based on the cultivars derived from the species Actinidia chinensis (Ac) which may bring risks such as canker disease. Introgression of desired traits from wild relatives is an important method for improving kiwifruit cultivars. Actinidia eriantha (Ae) is a particularly important taxon used for hybridization or introgressive breeding of new kiwifruit cultivars because of its valued species-specific traits. Here, we assembled a chromosome-scale high-quality genome of a Ae sample which was directly collected from its wild populations. Our analysis revealed that 41.3% of the genome consists of repetitive elements, comparable to the percentage in Ac and Ae cultivar “White” genomes. The genomic structural variation, including the presence/absence-variation (PAV) of genes, is distinct between Ae and Ac, despite both sharing the same two kiwifruit-specific whole genome duplication (WGD) events. This suggests that a post-WGD divergence mechanism occurred during their evolution. We further investigated genes involved in ascorbic acid biosynthesis and disease-resistance of Ae, and we found introgressive genome could contribute to the complex relationship between Ae and other representative kiwifruit taxa. Collectively, the Ae genome offers valuable genetic resource to accelerate kiwifruit breeding applications.

Abstract Medulloblastoma (MB) is one of the most common childhood malignant brain tumors (WHO grade IV), traditionally divided into WNT, SHH, Group 3, and Group 4 subgroups based on the transcription profiles, somatic DNA alterations, and clinical outcomes. Unlike WNT and SHH subgroup MBs, Group 3 and Group 4 MBs have similar transcriptomes and lack clearly specific drivers and targeted therapeutic options. The recently revised WHO Classification of CNS Tumors has assigned Group 3 and 4 to a provisional non-WNT/SHH entity. In the present study, we demonstrate that Kir2.1, an inwardly-rectifying potassium channel, is highly expressed in non-WNT/SHH MBs, which promotes tumor cell invasion and metastasis by recruiting Adam10 to enhance S2 cleavage of Notch2 thereby activating the Notch2 signaling pathway. Disruption of the Notch2 pathway markedly inhibited the growth and metastasis of Kir2.1-overexpressing MB cell-derived xenograft tumors in mice. Moreover, Kir2.1high/nuclear N2ICDhigh MBs are associated with the significantly shorter lifespan of the patients. Thus, Kir2.1high/nuclear N2ICDhigh can be used as a biomarker to define a novel subtype of non-WNT/SHH MBs. Our findings are important for the modification of treatment regimens and the development of novel-targeted therapies for non-WNT/SHH MBs.

Repair of bone defects remains a major challenge in the field of orthopedics. Biodegradable zinc (Zn) has been considered as a revolutionary material for bone repair. However, it exhibits relatively poor mechanical strength and cytocompatibility as well as slow degradation rate, hindering its potential application as bone repair material. In the present work, biodegradable Zn-1 wt%Mg-nvol%β-TCP (n = 0, 1, 3, 5, 10) composites are fabricated via vacuum heating-press sintering to address the above concerns. The results show that the addition of magnesium (Mg) and beta-tricalcium phosphate (β-TCP) positively regulate the mechanical properties, degradation properties, and osteogenic activity of the composites. Zn-1 wt%Mg-3 vol%β-TCP possess the highest compressive yield strength of approximately 243.9 MPa compared with about 137.6 MPa of pure Zn. The in vitro corrosion rates of the Zn-1Mg-β-TCP composites are tunable between 0.428 and 0.546 mm/y. The 24-week in vivo experiments prove that the Zn-1Mg-β-TCP composites possess better osteogenic activity than that of pure Zn. In general, the Zn-1Mg-β-TCP composites exhibit suitable mechanical strength and degradation rate, coupled with their great biological activity, which are expected to provide reliable performance for clinical bone repair.

AimsTo investigate cardiac pathology in critically ill patients with coronavirus disease 2019 (COVID-19) and identify associations between pathological changes and clinical characteristics.MethodsThe present autopsy cohort study included hearts from 26 deceased patients hospitalized in intensive care units due to COVID-19, and was conducted at four sites in Wuhan, China. Cases were divided into a neutrophil infiltration group and a no-neutrophil group based on the presence or absence of histopathologically identified neutrophilic infiltrates.ResultsAmong the 26 patients, histopathological examination identified active myocarditis in four patients. All patients with myocarditis exhibited extensive accompanying neutrophil infiltration, and all patients without myocarditis did not. The neutrophil infiltration group exhibited significantly higher rates of detection of interleukin-6 (100 vs. 4.6%) and tumor necrosis factor-alpha (100 vs. 31.8%) than the no-neutrophil group (both p < 0.05). On admission, four patients with neutrophil infiltration in myocardium had significantly higher baseline levels of aspartate aminotransferase, D dimer, and high-sensitivity C reactive protein than the other 22 patients (all p < 0.05). During hospitalization, patients with neutrophil infiltration had significantly higher maximum creatine kinase-MB (median 280.0 IU/L vs. 38.7 IU/L, p = 0.04) and higher troponin I (median 1.112 ng/ml vs. 0.220 ng/ml, p = 0.56) than patients without neutrophil infiltration.ConclusionActive myocarditis was frequently associated with neutrophil infiltration in the hearts of deceased patients with severe COVID-19. Patients with neutrophil-infiltrated myocarditis had a series of severely abnormal laboratory test results on admission, and high maximum creatine kinase-MB during hospitalization. The role of neutrophils in severe heart injury and systemic conditions in patients with COVID-19 should be emphasized.

Abstract Background Plant phylogeographic studies of species in subtropical China have mainly focused on rare and endangered species, whereas few studies have been conducted on taxa with relatively wide distribution, especially polyploid species. We investigated the cytotype and haplotype distribution pattern of the Actinidia chinensis complex, a widespread geographically woody liana with variable ploidy in subtropical China comprising two varieties, with three chloroplast fragments DNA (ndhF-rpl132, rps16-trnQ and trnE-trnT). Macroevolutionary, microevolutionary and niche modeling tools were also combined to disentangle the origin and the demographic history of the species or cytotypes. Results The ploidy levels of 3338 individuals from 128 populations sampled throughout the species distribution range were estimated with flow cytometry. The widespread cytotypes were diploids followed by tetraploids and hexaploids, whereas triploids and octoploids occurred in a few populations. Thirty-one chloroplast haplotypes were detected. The genetic diversity and genetic structure were found to be high between varieties (or ploidy races) chinensis and deliciosa. Our results revealed that these two varieties inhabit significantly different climatic niche spaces. Ecological niche models (ENMs) indicate that all varieties’ ranges contracted during the Last Inter Glacial (LIG), and expanded eastward or northward during the Last Glacial Maximum (LGM). Conclusions Pliocene and Plio-Pleistocene climatic fluctuations and vicariance appear to have played key roles in shaping current population structure and historical demography in the A. chinensis complex. The polyploidization process also appears to have played an important role in the historical demography of the complex through improving their adaptability to environmental changes.

Vasculogenic mimicry (VM) contributes to the development of triple-negative breast cancer. In this study, the authors show that TEM8 is expressed in VM-forming breast cancer stem cells and it promotes stemness and VM differentiation capacity through a RhoC/ROCK1/SMAD5 axis

A multi-functional composite coating was fabricated on magnesium (Mg) AZ31 alloy through micro-arc oxidation (MAO) combined with self-assembly technology. Polyethyleneimine (PEI) as a medium was assembled on MAO coating based on the chemical bonding and electrostatic interactions. Adhered PEI successfully mediates the self-assembly of functional silver nanoparticles (Ag NPs) with a formation of Ag NPs/PEI/MAO (APM) composite coating. The morphology and microstructure of as-prepared APM coating were characterized by using of different technologies (e.g. scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy). Its corrosion behavior in simulated body fluid and the corresponding antibacterial performance against Staphylococcus aureus (S. aureus) were also investigated. The potentiodynamic polarization results showed that the corrosion current density of APM coated AZ31 decreased more than three orders of magnitude in comparison with that of uncoated AZ31, indicating an enhanced anticorrosive ability. Electrochemical impedance spectroscopy results further revealed that the improvement of corrosion resistance was attributed to a synergistic effect of Ag NPs/PEI and MAO. The hydrogen evolution tests confirmed that APM coating provided AZ31 an excellent corrosion protection during a relatively long term. And the antibacterial research showed that APM coated AZ31 had a great antibacterial activity. This study presents a promising approach to fabricate a multi-functional composite coating on Mg alloy, which improves the anticorrosive performance of the substrate and endows it an antibacterial activity to meet a better demand in the applications.

Bone marrow mesenchymal stem cells (BMSCs) have self-renewal, multi-directional differentiation potential, and immune regulation function and are widely used for de novo bone formation. However, the wide variation in individual amplification, the potential risk of cancer cell contamination, and the need for culture time significantly limit their widespread use clinically. Alternatively, numerous studies have shown that exosomes secreted by BMSCs in the nanoscale can also affect the functionality of endothelial cells (angiogenesis), macrophages (immunomodulation), and osteoblasts/osteoclasts (osteogenesis), which is a highly promising therapy for osseointegration with pronounced advantages (e.g., safety, high efficiency, and no ethical restrictions). The review aims to summarize the multifaceted effect of BMSCs-derived exosomes on osseointegration and provide reference and basis for rapid and qualified osseointegration.

Atmospheric deposition can supply nutrients to induce varying responses of phytoplankton of different sizes in the upper ocean. Here, we collected surface and subsurface chlorophyll a maximum (SCM) seawaters from the Yellow Sea and East China Sea to conduct a series of onboard incubation experiments, aiming to explore the impact of anthropogenic aerosol (AR, sampled in Qingdao, a coastal city in Northern China) addition on phytoplankton growth using schemes with (unfiltered seawater, UFS) and without (filtered seawater, FS) microsized (20–200 μm) cells. We found that AR addition stimulated phytoplankton growth obviously, as indicated by chlorophyll a (Chl a) in surface incubations, and had stimulatory or no effects in SCM incubations, which was related to nutrient statuses in seawater. The high ratio of nitrogen (N) to phosphorus (P) in the AR treatments demonstrated that P became the primary limiting nutrient. The alkaline phosphatase activity (APA), which can reflect the rate at which dissolved organic P (DOP) is converted into dissolved inorganic P, was 1.3–75.5 times higher in the AR treatments than in the control, suggesting that AR addition increased P bioavailability in the incubated seawater. Dinoflagellates with the capacity to utilize DOP showed the dominant growth in the AR treatments, corresponding to the shift in phytoplankton size structure toward larger cells. Surprisingly, we found that nanosized (2–20 μm) and picosized (0.2–2 μm) Chl a concentrations in UFS were generally higher than those in FS. The APA in UFS was at least 1.6 times higher than in FS and was proportional to the contribution of microsized cells to the total Chl a, suggesting that microsized cells play an important role in the increase in APA, which contributes to the growth of nanosized and picosized phytoplankton. Current work provides new insight into the increase of P bioavailability induced by atmospheric deposition and resultant ecological effect in coastal waters.

Stratospheric ozone intrusion plays an important role in affecting the tropospheric ozone concentrations in the troposphere through stratosphere to troposphere transport (STT). Nevertheless, there are very limited studies on the quantification of the effect. Focusing on a typical event on 9–12 May 2015, when STT occurs over the northeastern Qinghai–Tibet Plateau of China, the observations and reanalysis data indicate that STT is accompanied by high potential vorticity and low specific humidity. In order to quantify the extent to which the STT may elevate the ozone concentrations, an inert tracer is added to the boundary conditions of the Community Multiscale Air Quality (CMAQ), which is driven by the Weather Research and Forecasting (WRF) model. The meteorological conditions simulated by WRF nicely reproduce the distributions of potential vorticity (PV) and water vapor in the upper troposphere. Through the physical processes of diffusion, advection, and dry and wet deposition, the ozone tracer concentrations simulated from CMAQ well capture the spatial propagation and evolution of stratospheric ozone intrusion over Qinghai–Tibet Plateau, warranting the confidence in interpreting the simulated results in quantifying the STT. The STT event indicates the near-surface ozone enhancement of approximately 10–20 ppbv covering half of Qinghai province, even spreading to a broader area of eastern China. For the typical remote mountain such as Waliguan, clear ozone enhancement is obtained over the lower level of the troposphere. The method used in this study is applicable to other regions as well, which can be applied in the future to detect the STT at a wider spatiotemporal scale and help the policymakers identify the ozone sources and make efficient strategies for the ozone pollution control.

Treatment of implant-associated infection is becoming more challenging, especially when bacterial biofilms form on the surface of the implants. Developing multi-mechanism antibacterial methods to combat bacterial biofilm infections by the synergistic effects are superior to those based on single modality due to avoiding the adverse effects arising from the latter. In this work, TiO2 nanorod arrays in combination with irradiation with 808 near-infrared (NIR) light are proven to eradicate single specie biofilms by combining photothermal therapy, photodynamic therapy, and physical killing of bacteria. The TiO2 nanorod arrays possess efficient photothermal conversion ability and produce a small amount of reactive oxygen species (ROS). Physiologically, the combined actions of hyperthermia, ROS, and puncturing by nanorods give rise to excellent antibacterial properties on titanium requiring irradiation for only 15 min as demonstrated by our experiments conducted in vitro and in vivo. More importantly, bone biofilm infection is successfully treated efficiently by the synergistic antibacterial effects and at the same time, the TiO2 nanorod arrays improve the new bone formation around implants. In this protocol, besides the biocompatible TiO2 nanorod arrays, an extra photosensitizer is not needed and no other ions would be released. Our findings reveal a rapid bacteria-killing method based on the multiple synergetic antibacterial modalities with high biosafety that can be implemented in vivo and obviate the need for a second operation. The concept and antibacterial system described here have large clinical potential in orthopedic and dental applications.

Objective: To evaluate the technical success rate and reproducibility of sound touch elastography (STE) and sound touch quantification (STQ) in liver and spleen stiffness measurement and the reference ranges of normal liver and spleen stiffness. We also compared with a previous validated acoustic radiation force impulse (ARFI) technique.Methods: Two hundred and fifty-three healthy adults and 40 chronic hepatitis B patients were recruited. All patients underwent liver and spleen stiffness measurements using STE, STQ, and ARFI. A hundred and five patients (36 patients with chronic hepatitis and 69 healthy adults) were examined twice, by two trained sonographers who are familiar with STE and STQ techniques independently. Another 36 healthy adults were examined twice by ARFI imaging. The technical success rates and reproducibility were evaluated.Results: The success rates of STE, STQ, and ARFI were 96.5%, 95.1%, and 94.8% in liver, and 87.5%, 84.0%, and 78.0% in spleen, respectively. The inter-observer reproducibility of STE, STQ and ARFI were 0.914, 0.896, and 0.845 in liver, and 0.629, 0.601, and 0.543 in spleen, respectively. When the thickness of spleen was greater than 30mm, the reproducibility was 0.704 in STE and 0.668 in STQ. The normal ranges of liver stiffness were 5.80-6.04 kPa measured by STE and 5.87-6.13 kPa measured by STQ, and normal spleen stiffness ranged from 14.83-15.54 kPa measured by STE and 15.85-16.62 kPa measured by STQ.Conclusion: Our study showed STE and STQ in liver and spleen stiffness measurement had a high success rate with good reproducibility, which were comparable to ARFI. The inter-observer reproducibility of spleen was barely satisfactory, but was good when the thickness of spleen was greater than 30mm.

The cytokine like protein FAM3D (Fam3D in mice) is highly expressed in the digestive tract with unknown role in colon pathophysiology. Here, by using gene deficient mice, the authors show that Fam3D is critically involved in colon homeostasis, host defense against colitis-associated carcinogenesis, and the balance of microbiota.

Although increases in air pollutants are changing chemical compositions of atmosphere, the resultant impacts on marine biogeochemistry remains elusive. We performed a collective analysis of 12 microcosm experimental data concerning treatments of dust particles (DPs, typically mineral aerosols), haze particles (HPs, typically anthropogenic aerosols), and various nutrients in varying trophic seawaters of the Northwest Pacific Ocean. The addition of DPs and HPs generally stimulated phytoplankton growth, as indicated by total chlorophyll a (Chl a), and shifted the phytoplankton size structure towards larger cells (> 2 µm in cell size), as indicated by size-fractionated Chl a. We further found that DP/HP-derived Chl a increase relative to the control (RCChl a) was proportional to the proportion of nitrogen (N) supplied by DPs/HPs relative to the baseline N concentration in seawater (PSN) and was higher than that in the N alone treatment when the PSN exceeded ~480%. The enhanced utilization of dissolved organic P potentially contributed to the stimulation of DPs/HPs. The slope of fitted line based on RCChl a and PSN in the DP treatments (0.14) was higher than that in the HP treatments (0.11). When the particle loading was extremely high (2 mg L−1), the addition of HPs exhibited an obvious inhibition impact on phytoplankton and was adverse to the shift of the size structure towards larger cells. These results suggest that the impact of HPs on phytoplankton is a composite result of stimulation by nutrients and inhibition by toxic matter, which may affect carbon sequestration efficiency in the ocean by regulating phytoplankton biomass and size structure.

Chemically resolved data for fine particulate matter (PM2.5) have been collected across Canada since 2003 through the National Air Pollution Surveillance (NAPS) network. Seven urban sites that have 10–17 years (2003–2019) of PM2.5 organic carbon (OC) and elemental carbon (EC) data were selected for analysis of decadal trends of OC, EC, and OC/EC ratio using the Ensemble Empirical Mode Decomposition method. Results showed that OC and EC decreased by 0.009–0.072 μg m−3 yr−1 and 0.028–0.049 μg m−3 yr−1, or 0.77–3.1 % yr−1 and 3.2–6.7 % yr−1, respectively, depending on the location. The more rapid decrease in EC than OC resulted in an increasing trend in the OC/EC ratio of 0.03–0.19 yr−1 across the sites. Macro-tracer approach was used to estimate source attributions of OC and EC from wood burning, fossil fuel combustion, and secondary aerosol formation. Using this approach, it was identified that the significant decrease in EC during the past decade was predominately caused by reduced on-road emissions. The decreased emissions from wood burning and transportation dominated the decline of OC, but such a decline was largely offset by the enhanced secondary organic aerosol (SOA) formation, resulting in much weaker decline of OC than EC. The enhanced SOA formation was due to the increased biogenic emissions fully offsetting the decreased anthropogenic emissions for volatile organic compounds. These findings highlight the need for quantifying biogenic sources of VOCs and other oxidants that are involved in OC formation at the national scale.

Objective Glioblastoma (GBM) is the most common primary malignant brain tumor regulated by numerous genes, with poor survival outcomes and unsatisfactory response to therapy. Therefore, a robust, multi-gene signature-derived model is required to predict the prognosis and treatment response in GBM.Methods Gene expression data of GBM from TCGA and GEO datasets were used to identify differentially expressed genes (DEGs) through DESeq2 or LIMMA methods. The DEGs were then overlapped and used for survival analysis by univariate and multivariate COX regression. Based on the gene signature of multiple survival-associated DEGs, a risk score model was established, and its prognostic and predictive role was estimated through Kaplan–Meier analysis and log-rank test. Gene set enrichment analysis (GSEA) was conducted to explore high-risk score-associated pathways. Western blot was used for protein detection.Results Four survival-associated DEGs of GBM were identified: OSMR, HOXC10, SCARA3, and SLC39A10. The four-gene signature-derived risk score was higher in GBM than in normal brain tissues. GBM patients with a high-risk score had poor survival outcomes. The high-risk group treated with temozolomide chemotherapy or radiotherapy survived for a shorter duration than the low-risk group. GSEA showed that the high-risk score was enriched with pathways such as vasculature development and cell adhesion. Western blot confirmed that the proteins of these four genes were differentially expressed in GBM cells.Conclusions The four-gene signature-derived risk score functions well in predicting the prognosis and treatment response in GBM and will be useful for guiding therapeutic strategies for GBM patients.

Both subventricular zone (SVZ) contact and isocitrate dehydrogenase 1 (IDH1) mutation have been reported to be related to the outcome of glioma, respectively. However, far too little attention has been paid to the role of tumor edge-SVZ distance in the outcome of glioma. We aim to assess the value of tumor-SVZ distance, as well as combined tumor-SVZ distance and IDH status, in predicting the outcome of gliomas (WHO grade II–IV). Here, the MR images and clinical data from 146 patients were included in the current study. The relationship between survival and the tumor-SVZ distance as well as survival and combination of tumor-SVZ distance and IDH status were determined via univariate and multivariate analyses. In univariate analysis of tumor-SVZ distance, the patients were divided into three types (SVZ involvement, tumor-SVZ distance from 0 to 10 mm, and tumor-SVZ distance >10 mm). The results showed that the OS (p = 0.02) and PFS (p = 0.002) for the patients had a positive correlation with the tumor-SVZ distance. In addition, simple linear correlation found a significant relationship between the two parameters (OS and PFS) and tumor-SVZ distance in patients with non-SVZ-contacting glioma. Combination analysis of the tumor-SVZ distance and IDH status showed that IDH1 mutation and SVZ non-involvement enable favorable outcomes, whereas IDH1 wild type with SVZ involvement indicates a significantly worse prognosis in all patients. Moreover, in patients with non-SVZ-contacting glioma, IDH1 mutation concurrent with tumor-SVZ distance >10 mm has better OS and PFS. IDH1 wild type and tumor-SVZ distance from 0 to 10 mm suggest poorer OS and PFS. Multivariate analysis showed WHO grade IV, SVZ involvement, tumor-SVZ distance from 0 to 10 mm, IDH1 mutation, gross total resection, and chemotherapy serve as independent predictors of OS. WHO grade IV, SVZ involvement, tumor-SVZ distance from 0 to 10 mm, IDH1 mutation, and chemotherapy serve as independent predictors of PFS of patients with glioma. In conclusion, tumor-SVZ distance and IDH1 mutation status are the determinants affecting patient outcome.

Environmental pollution due to resistance genes from livestock manure has become a serious issue that needs to be resolved. However, little studies focused on the removal of resistance genes in simultaneous processing of livestock feces and urine. This study investigated the fate of antibiotic resistance genes (ARGs), metal resistance genes (MRGs), and class 1 integron-integrase gene (intI1) during thermophilic fermentation of swine manure in an ectopic fermentation system (EFS), which has been regarded as a novel system for efficiently treating both feces and urine. The abundances of MRGs and tetracycline resistance genes were 34.44–97.71% lower in the EFS. The supplementation of heavy metals significantly increased the abundance of intI1, with the enhancement effect of copper being more prominent than that of zinc. The highest abundances of resistance genes and intI1 were observed at high Cu levels (A2), indicating that Cu can increase the spreading of resistance genes through integrons. Network analysis revealed the co-occurrence of ARGs, MRGs, and intI1, and these genes potentially shared the same host bacteria. Redundancy analysis showed that the bacterial community explained most of the variations in ARGs, and environmental factors had influences on ARGs abundances by modulating the bacterial community composition. The decreased Sphingomonas, Comamonas, Acinetobacter, Lactobacillus, Bartonella, Rhizobium, and Bacteroides were mainly responsible for the reduced resistance genes. These results demonstrate that EFS can reduce resistance genes in simultaneous processing of livestock feces and urine.

Wild peach is an important resource for improving existing peach varieties. However, the extant populations of wild peach show fragmented distribution due to human disturbance and geographic isolation. In this study, we used natural populations (or wild populations) of Prunus persica (Rosaceae) to assess the genetic effects of habitat fragmentation. A total of 368 individuals sampled from 16 natural populations were analyzed using 23 polymorphic simple sequence repeat (SSR) markers. Prunus persica maintained low within-population genetic variation and high level of genetic differentiation. Two genetic clusters were revealed based on three different methods (UPGMA, PCoA, and STRUCTURE). All populations showed a significant heterozygosity deficiency and most extant populations experienced recent reduction in population size. A significant isolation by distance (IBD) was observed with Mantel’s test. Compared to historical gene flow, contemporary gene flow was restricted among the studied populations, suggesting a decrease in gene flow due to habitat fragmentation. Habitat fragmentation has impacted population genetic variation and genetic structure of P. persica. For breeding and conservation purpose, collecting as many individuals as possible from multiple populations to maximize genetic diversity was recommended during the process of germplasm collection. In addition, populations from central China had higher genetic diversity, suggesting these populations should be given priority for conservation and germplasm collection.

Understanding genetic diversity and structure in natural populations and their suitable habitat response to environmental changes is critical for the protection and utilization of germplasm resources. We evaluated the genetic diversity and structure of 24 A. chinensis populations using simple sequence repeat (SSR) molecular markers. The potential suitable distribution of tetraploid A. chinensis estimated under the current climate and predicted for the future climate was generated with ecological niche modeling (ENM). The results indicated that the polyploid populations of A.chinensis have high levels of genetic diversity and that there are distinct eastern and western genetic clusters. The population structure of A. chinensis can be explained by an isolation-by-distance model. The results also revealed that potentially suitable areas of tetraploids will likely be gradually lost and the habitat will likely be increasingly fragmented in the future. This study provides an extensive overview of tetraploid A. chinensis across its distribution range, contributing to a better understanding of its germplasm resources. These results can also provide the scientific basis for the protection and sustainable utilization of kiwifruit wild resources.

The ambient formation of secondary particulate matter (ambient FSPM) is commonly recognized as the major cause of severe PM2.5 air pollution in China. We present observational evidence showing that the ambient FSPM was too weak to yield a detectable contribution to extreme PM2.5 pollution events that swept northern China between 11 and 14 January 2019. Although the Community Multiscale Air Quality (CMAQ) model (v5.2) reasonably reproduced the observations in January 2019, it largely underestimated the concentrations of the PM2.5 during the episode. We propose a novel mechanism, called the “in-fresh-stack-plume non-precipitation-cloud processing of aerosols” followed by the evaporation of semi-volatile components from the aerosols, to generate PM2.5 at extremely high concentrations because of highly concentrated gaseous precursors and large amounts of water droplets in fresh cooling combustion plumes under poor dispersion conditions, low ambient temperature, and high relative humidity. The recorded non-precipitation-cloud processing of the aerosols in fresh stack combustion plumes normally lasts 20–30 s, but it prolongs as long as 2–5 min under cold, humid, and stagnant meteorological conditions and expectedly causes severe PM2.5 pollution events. Regardless of the presence of the natural cloud in the planetary boundary layer during the extreme events, the fast conversion of air pollutants in water droplets and the generation of the PM2.5 through the non-precipitation-cloud processing of aerosols always occur in fresh combustion plumes. The processing of aerosols is detectable using a nano-scan particle sizer assembled on an unmanned aerial vehicle to monitor the particle formation in stack plumes. In-fresh-stack-plume processed aerosols under varying meteorological conditions need to be studied urgently.