Insights into comparative genomics, structural features, and phylogenetic relationship of species from Eurasian Aster and its related genera (Asteraceae: Astereae) based on complete chloroplast genome.

Aster L. is an economically and phylogenetically important genus in the tribe Astereae. Here, the complete plastomes of the eight Aster species were assembled and characterized using next-generation sequencing datasets. The results indicated the complete plastomes of Aster had a quadripartite structure. These genomes were 152,045-152,729 bp in length and contained 132-133 genes, including 87 protein-coding genes, 37-38 tRNA genes, and eight rRNA genes. Expansion or contraction of inverted repeat regions and forward, palindromic, complement, and reverse repeats were detected in the eight Aster species. Additionally, our analyses showed the richest type of simple sequence repeats was A/T mononucleotides, and 14 highly variable regions were discovered by analyzing the border regions, sequence divergence, and hotspots. Phylogenetic analyses indicated that 27 species in Astereae were clustered into six clades, i.e., A to D, North American, and outgroup clades, and supported that the genera Heteropappus, Kalimeris, and Heteroplexis are nested within Aster. The results indicated the clades B to D might be considered as genera. Divergence time estimate showed the clades A, B, C, and D diverged at 23.15 Mya, 15.13 Mya, 24.29 Mya, and 21.66 Mya, respectively. These results shed light on the phylogenetic relationships of Aster and provided new information on species identification of Aster and its related genera.

Comprehensive molecular characterization of long-term glioblastoma survivors.

Fewer than 5% glioblastoma (GBM) patients survive over five years and are termed long-term survivors (LTS), yet their molecular background is unclear. The present cohort included 72 isocitrate dehydrogenase (IDH)-wildtype GBM patients, consisting of 35 LTS and 37 short-term survivors (STS), and we employed whole exome sequencing, RNA-seq and DNA methylation array to delineate this largest LTS cohort to date. Although LTS and STS demonstrated analogous clinical characters and classical GBM biomarkers, CASC5 (P = 0.002) and SPEN (P = 0.013) mutations were enriched in LTS, whereas gene-to-gene fusions were concentrated in STS (P = 0.007). Importantly, LTS exhibited higher tumor mutation burden (P < 0.001) and copy number (CN) increase (P = 0.013), but lower mutant-allele tumor heterogeneity score (P < 0.001) and CN decrease (P = 0.026). Additionally, LTS demonstrated hypermethylated genome (P < 0.001) relative to STS. Differentially expressed and methylated genes both enriched in olfactory transduction. Further, analysis of the tumor microenvironment revealed higher infiltration of M1 macrophages (P = 0.043), B cells (P = 0.016), class-switched memory B cells (P = 0.002), central memory CD4+ T cells (P = 0.031) and CD4+ Th1 cells (P = 0.005) in LTS. We also separately analyzed a subset of patients who were methylation class-defined GBM, contributing 70.8% of the entire cohort, and obtained similar results relative to prior analyses. Finally, we demonstrated that LTS and STS could be distinguished using a subset of molecular features. Taken together, the present study delineated unique molecular attributes of LTS GBM.

Optical biomarker analysis for renal cell carcinoma obtained from preoperative and postoperative patients using ATR-FTIR spectroscopy.

Renal cell carcinoma (RCC) is the most common malignant tumor in the urinary system, accounting for 80 % to 90 % for all renal malignancies. Traditional diagnostic methods like magnetic resonance imaging (MRI) and computed tomography (CT) lack the sensitivity and specificity as they lack specific biomarkers. These limitations impede effective monitoring of tumor recurrence. This study aims to employ Attenuated Total Reflection (ATR)-Fourier transform infrared (FTIR) spectroscopy, an optical technology sensitive to molecular groups, to analyze the potential optical biomarkers in urine and plasma samples from RCC patients pre- and post-surgery. The results reveal distinctive spectral information from both plasma and urine samples. Post-surgery urine spectra exhibit complexity compared to plasma, showing reduced content at 1072 cm-1, 1347 cm-1 and 1654 cm-1 bands, while increased content at 1112 cm-1, 1143 cm-1, 1447 cm-1, 3334 cm-1 and 3420 cm-1 bands. Utilizing machine learning models such as eXtreme Gradient Boosting (XGBoost), support vector machine (SVM), partial least squares (PLS), and artificial neural network (ANN), the study evaluated plasma and urine samples pre- and post-surgery. Remarkably, the XGBoost method excelled in distinguishing between tumor conditions and recovery, achieving an impressive AUC value of 0.99. These results underscore the potential of ATR-FTIR technology in identifying RCC optical biomarkers, with XGBoost showing promise as a valuable screening tool for RCC recurrence diagnosis.

In situ phytoextraction of Mn and NH4+-N from aqueous electrolytic manganese residue solution by Pistia stratiotes: Effects of Fe/Co presence and rhizospheric microbe synergistic involvement.

The electrolytic manganese industry produces a large amount of electrolytic manganese residue (EMR). Soluble Mn, NH4+-N, and other pollutants may be released from the open-air stacked EMR and transported to the environment along with rainfall or surface runoff. Aqueous EMR solution (AES) generally contains various elements required for plant growth, and phytoremediation can be applied to remove these pollutants from AES. Since the contents of Fe and Co vary greatly in AES depending on the ore sources as well as the pre-treatment processes, the presence of bioavailable Fe and Co at different levels may affect plant growth, the rhizosphere microbes, and pollutant removal. The present study investigated the in-situ removal of Mn(II) and NH4+-N from AES solution using free floating aquatic plant Pistia stratiotes, focusing especially on the effects of Fe/Co presence and rhizospheric microbe synergistic involvement on contaminant removal. The results showed that 69.08% of Mn and 94.99% of NH4+-N were removed by P. stratiotes in 24 d. Both the presence of Fe(II) and Co(II) facilitated the Mn(II) immobilization and increased Mn(II) removal by 19-31% due to the enhanced peroxidase activity and the increased Mn accumulating in roots The complete removal of Mn from AES was found in the presence of Fe(II) at 2 mg·L-1 or Co(II) at 0.5 mg·L-1 and more than 51% accumulated Mn in the roots was stored in the vacuole and cytoplasm. BioMnOx was found on the surface of the roots, revealing that rhizofiltration, rhizospheric plaque/biofilm formation, and Mn biogeochemical cycle exert synergic effects on Mn(II) immobilization. The findings of the present study demonstrate the feasibility of using P. stratiotes in the treatment of aqueous EMR solutions and the presence of an appropriate amount of bio-available Fe and Co can promote the removal of Mn(II) and NH4+-N.

Effects of different assembly strategies on gene annotation in activated sludge.

Activated sludge comprises diverse bacteria, fungi, and other microorganisms, featuring a rich repertoire of genes involved in antibiotic resistance, pollutant degradation, and elemental cycling. In this regard, hybrid assembly technology can revolutionize metagenomics by detecting greater gene diversity in environmental samples. Nonetheless, the optimal utilization and comparability of genomic information between hybrid assembly and short- or long-read technology remain unclear. To address this gap, we compared the performance of the hybrid assembly, short- and long-read technologies, abundance and diversity of annotated genes, and taxonomic diversity by analysing 46, 161, and 45 activated sludge metagenomic datasets, respectively. The results revealed that hybrid assembly technology exhibited the best performance, generating the most contiguous and longest contigs but with a lower proportion of high-quality metagenome-assembled genomes than short-read technology. Compared with short- or long-read technologies, hybrid assembly technology can detect a greater diversity of microbiota and antibiotic resistance genes, as well as a wider range of potential hosts. However, this approach may yield lower gene abundance and pathogen detection. Our study revealed the specific advantages and disadvantages of hybrid assembly and short- and long-read applications in wastewater treatment plants, and our approach could serve as a blueprint to be extended to terrestrial environments.

R3 strain and Fe-Mn modified biochar reduce Cd absorption capacity of roots and available Cd content of soil by affecting rice rhizosphere and endosphere key flora.

Microorganisms have a significant role in regulating the absorption and transportation of Cd in the soil-plant system. However, the mechanism by which key microbial taxa play a part in response to the absorption and transportation of Cd in rice under Cd stress requires further exploration. In this study, the cadmium-tolerant endophytic bacterium Herbaspirillum sp. R3 (R3) and Fe-Mn-modified biochar (Fe-Mn) were, respectively, applied to cadmium-contaminated rice paddies to investigate the effects of key bacterial taxa in the soil-rice system on the absorption and transportation of Cd in rice under different treatments. The results showed that both R3 and Fe-Mn treatments considerably decreased the content of cadmium in roots, stems and leaves of rice at the peak tillering stage by 17.24-49.28% in comparison to the control (CK). The cadmium content reduction effect of R3 treatment is better than that of Fe-Mn treatment. Further analysis revealed that the key bacterial taxa in rice roots under R3 treatment were Sideroxydans and Actinobacteria, and that their abundance showed a substantial positive correlation and a significant negative correlation with the capacity of rice roots to assimilate Cd from the surroundings, respectively. The significant increase in soil pH under Fe-Mn treatment, significant reduction in the relative abundances of Acidobacteria, Verrucomicrobia, Subdivision3 genera incertae sedis, Sideroxydans, Geobacter, Gp1, and Gp3, and the significant increase in the relative abundance of Thiobacillus among the soil bacterial taxa may be the main reasons for the decrease in available Cd content of the soil. In addition, both the R3 and Fe-Mn treatments showed some growth-promoting effects on rice, which may be related to their promotion of transformations of soil available nutrients. This paper describes the possible microbial mechanisms by which strain R3 and Fe-Mn biochar reduce Cd uptake in rice, providing a theoretical basis for the remediation of Cd contamination in rice and soil by utilizing key microbial taxa.

Effect of dental chew on reducing dental plaque, dental calculus and halitosis in beagle dogs.

Periodontosis is the most common clinical disease in adult dogs, which is mainly caused by plaque accumulation and seriously endangers the oral health of dogs and even cause kidney, myocardial, and liver problems in severe cases. The aim of this study was to determine the clinical efficacy of dental chew (Cature Brushing Treats product) with mechanical and chemical properties in beagles. The dogs in the experimental group were fed with a dental chew twice a day after meals; The control group had no treatment. Dental plaque was evaluated on the 14th day and 29th day, respectively. The concentration of volatile sulfur compounds (VSC) in the breath and dental calculus were also evaluated on the 29th day. The results showed that there was no significant difference in the indexes of dental plaque on the 14th day. While they had significantly reduced accumulation of plaque (37.63%), calculus (37.61%), and VSC concentration (81.08%) compared to when receiving no chew on the 29th day.

Burkholderia ambifaria H8 as an effective biocontrol strain against maize stalk rot via producing volatile dimethyl disulfide.

BACKGROUND: Maize stalk rot (MSR) caused by Fusarium graminearum is the primary factor contributing to the reduction in maize yield and quality. However, this soil-borne disease presents a significant challenge for sustainable control through field management and chemical agents. The screening of novel biocontrol agents can aid in developing innovative and successful strategies for MSR control. RESULTS: A total of 407 strains of bacteria were isolated from the rhizosphere soil of a resistant maize inbred line. One strain exhibited significant antagonistic activity in plate and pot experiments, and was identified as Burkholderia ambifaria H8. The strain could significantly inhibit the mycelial growth and spore germination of F. graminearum, induce resistance to stalk rot, and promote plant growth. The volatile compounds produced by strain H8 and its secondary metabolites in the sterile fermentation broth exhibited antagonistic activity. The primary volatile compound produced by strain H8 was identified as dimethyl disulfide (DMDS) using gas chromatography tandem mass spectrometry. Through in vitro antagonistic activity assays and microscopic observation, it was confirmed that DMDS was capable of inhibiting mycelial growth and disrupting the mycelial structure of F. graminearum, suggesting it may be the major active compound for strain H8. The transcriptome data of F. graminearum further indicated that strain H8 and its volatile compounds could alter pathogenic fungi metabolism, influence the related metabolic pathways, and potentially induce cell apoptosis within F. graminearum. CONCLUSION: Our results showed that B. ambifaria H8 was capable of producing the volatile substance dimethyl disulfide, which influenced the synthesis and permeability of cell membranes in pathogens. Thus, B. ambifaria H8 was found to be a promising biological control agent against MSR. © 2024 Society of Chemical Industry.

Upcycling of Cr-Containing Sulfate Waste into Efficient FeCrO3/Fe2O3 Catalysts for CO2 Hydrogenation Reaction.

Upcycling Cr-containing sulfate waste into catalysts for CO2 hydrogenation reaction benefits both pollution mitigation and economic sustainability. In this study, FeCrO3/Fe2O3 catalysts were successfully prepared by a simple hydrothermal method using Cr-containing sodium sulfate (Cr-SS) as a Cr source for efficient conversion and stable treatment of Cr. The removal rate of Cr in Cr-SS can reach 99.9% at the optimized hydrothermal conditions. When the synthesized catalysts were activated and used for the CO2 hydrogenation reaction, a 50% increase in CO2 conversion was achieved compared with the catalyst prepared by impregnation with a comparable amount of Cr. According to the extraction and risk assessment code (RAC) of the Reference Office of the European Community Bureau (BCR), the synthesized FeCrO3/Fe2O3 is risk-free. This work not only realizes the detoxification of the Cr-SS but transfers Cr into stable FeCrO3 for application in a catalytic field, which provides a strategy for the harmless disposal and resource utilization of Cr-containing hazardous waste.

Zeb1-controlled metabolic plasticity enables remodeling of chromatin accessibility in the development of neuroendocrine prostate cancer.

Cell plasticity has been found to play a critical role in tumor progression and therapy resistance. However, our understanding of the characteristics and markers of plastic cellular states during cancer cell lineage transition remains limited. In this study, multi-omics analyses show that prostate cancer cells undergo an intermediate state marked by Zeb1 expression with epithelial-mesenchymal transition (EMT), stemness, and neuroendocrine features during the development of neuroendocrine prostate cancer (NEPC). Organoid-formation assays and in vivo lineage tracing experiments demonstrate that Zeb1+ epithelioid cells are putative cells of origin for NEPC. Mechanistically, Zeb1 transcriptionally regulates the expression of several key glycolytic enzymes, thereby predisposing tumor cells to utilize glycolysis for energy metabolism. During this process, lactate accumulation-mediated histone lactylation enhances chromatin accessibility and cellular plasticity including induction of neuro-gene expression, which promotes NEPC development. Collectively, Zeb1-driven metabolic rewiring enables the epigenetic reprogramming of prostate cancer cells to license the adeno-to-neuroendocrine lineage transition.

Endogenous mutant Huntingtin alters the corticogenesis via lowering Golgi recruiting ARF1 in cortical organoid.

Pathogenic mutant huntingtin (mHTT) infiltrates the adult Huntington's disease (HD) brain and impairs fetal corticogenesis. However, most HD animal models rarely recapitulate neuroanatomical alterations in adult HD and developing brains. Thus, the human cortical organoid (hCO) is an alternative approach to decode mHTT pathogenesis precisely during human corticogenesis. Here, we replicated the altered corticogenesis in the HD fetal brain using HD patient-derived hCOs. Our HD-hCOs had pathological phenotypes, including deficient junctional complexes in the neural tubes, delayed postmitotic neuronal maturation, dysregulated fate specification of cortical neuron subtypes, and abnormalities in early HD subcortical projections during corticogenesis, revealing a causal link between impaired progenitor cells and chaotic cortical neuronal layering in the HD brain. We identified novel long, oriented, and enriched polyQ assemblies of HTTs that hold large flat Golgi stacks and scaffold clathrin+ vesicles in the neural tubes of hCOs. Flat Golgi stacks conjugated polyQ assemblies by ADP-ribosylation factor 1 (ARF1). Inhibiting ARF1 activation with Brefeldin A (BFA) disassociated polyQ assemblies from Golgi. PolyQ assembles with mHTT scaffolded fewer ARF1 and formed shorter polyQ assembles with fewer and shorter Golgi and clathrin vesicles in neural tubes of HD-hCOs compared with those in hCOs. Inhibiting the activation of ARF1 by BFA in healthy hCOs replicated impaired junctional complexes in the neural tubes. Together, endogenous polyQ assemblies with mHTT reduced the Golgi recruiting ARF1 in the neuroepithelium, impaired the Golgi structure and activities, and altered the corticogenesis in HD-hCO.

Development and Initial Characterization of the First 18F-CXCR2-Targeting Radiotracer for PET Imaging of Neutrophils.

The interleukin-8 receptor beta (CXCR2) is a highly promising target for molecular imaging of inflammation and inflammatory diseases. This is due to its almost exclusive expression on neutrophils. Modified fluorinated ligands were designed based on a squaramide template, with different modification sites and synthetic strategies explored. Promising candidates were then tested for affinity to CXCR2 in a NanoBRET competition assay, resulting in tracer candidate 16b. As direct 18F-labeling using established tosyl chemistry did not yield the expected radiotracer, an indirect labeling approach was developed. The radiotracer [18F]16b was obtained with a radiochemical yield of 15% using tert-butyl (S)-3-(tosyloxy)pyrrolidine carboxylate and a pentafluorophenol ester. The subsequent time-dependent uptake of [18F]16b in CXCR2-negative and CXCR2-overexpressing human embryonic kidney cells confirmed the radiotracer's specificity. Further studies with human neutrophils revealed its diagnostic potential for functional imaging of neutrophils.

Current understanding of the molecular mechanisms of chemotherapy-induced peripheral neuropathy.

Chemotherapy-induced peripheral neuropathy (CIPN) is the most common off-target adverse effects caused by various chemotherapeutic agents, such as cisplatin, oxaliplatin, paclitaxel, vincristine and bortezomib. CIPN is characterized by a substantial loss of primary afferent sensory axonal fibers leading to sensory disturbances in patients. An estimated of 19-85% of patients developed CIPN during the course of chemotherapy. The lack of preventive measures and limited treatment options often require a dose reduction or even early termination of life-saving chemotherapy, impacting treatment efficacy and patient survival. In this Review, we summarized the current understanding on the pathogenesis of CIPN. One prominent change induced by chemotherapeutic agents involves the disruption of neuronal cytoskeletal architecture and axonal transport dynamics largely influenced by the interference of microtubule stability in peripheral neurons. Due to an ineffective blood-nerve barrier in our peripheral nervous system, exposure to some chemotherapeutic agents causes mitochondrial swelling in peripheral nerves, which lead to the opening of mitochondrial permeability transition pore and cytochrome c release resulting in degeneration of primary afferent sensory fibers. The exacerbated nociceptive signaling and pain transmission in CIPN patients is often linked the increased neuronal excitability largely due to the elevated expression of various ion channels in the dorsal root ganglion neurons. Another important contributing factor of CIPN is the neuroinflammation caused by an increased infiltration of immune cells and production of inflammatory cytokines. In the central nervous system, chemotherapeutic agents also induce neuronal hyperexcitability in the spinal dorsal horn and anterior cingulate cortex leading to the development of central sensitization that causes CIPN. Emerging evidence suggests that the change in the composition and diversity of gut microbiota (dysbiosis) could have direct impact on the development and progression of CIPN. Collectively, all these aspects contribute to the pathogenesis of CIPN. Recent advances in RNA-sequencing offer solid platform for in silico drug screening which enable the identification of novel therapeutic agents or repurpose existing drugs to alleviate CIPN, holding immense promises for enhancing the quality of life for cancer patients who undergo chemotherapy and improve their overall treatment outcomes.

Hydroxylase-like Biomimetic Nanozyme Synthesized via a Urea-Mediated MOF Pyrolytic Reconstruction Strategy for Non-"o-Phenol hydroxyl"-Dependent Dopamine Electrochemical Sensing.

Dopamine (DA), an essential neurotransmitter, is closely associated with various neurological disorders, whose real-time dynamic monitoring is significant for evaluating the physiological activities of neurons. Electrochemical sensing methods are commonly used to determine DA, but they mostly rely on the redox reaction of its o-phenolic hydroxyl group, which makes it difficult to distinguish it from substances with this group. Here, we design a biomimetic nanozyme inspired by the coordination structure of the copper-based active site of dopamine ß-hydroxylase, which was successfully synthesized via a urea-mediated MOF pyrolysis reconstruction strategy. Experimental studies and theoretical calculations revealed that the nanozyme with Cu-N3 coordination could hydroxylate the carbon atom of the DA ß-site at a suitable potential and that the active sites of this Cu-N3 structure have the lowest binding energy for the DA ß-site. With this property, the new oxidation peak achieves the specific detection of DA rather than the traditional electrochemical signal of o-phenol hydroxyl redox, which would effectively differentiate it from neurotransmitters, such as norepinephrine and epinephrine. The sensor exhibited good monitoring capability in DA concentrations from 0.05 to 16.7 µM, and its limit of detection was 0.03 µM. Finally, the sensor enables the monitoring of DA released from living cells and can be used to quantitatively analyze the effect of polystyrene microplastics on the amount of DA released. The research provides a method for highly specific monitoring of DA and technical support for initial screening for neurocytotoxicity of pollutants.

Visualizing the crucial roles of plasma membrane and peroxynitrite during abdominal aortic aneurysm using two-photon fluorescence imaging.

Peroxynitrite (ONOO-) and cell plasma membrane (CPM) are two key factors in cell pyroptosis during the progression of abdominal aortic aneurysm (AAA). However, their combined temporal and spatial roles in initiating AAA pathogenesis remain unclear. Herein, we developed a two-photon fluorescence probe, BH-Vis, enabling real-time dynamic detection of CPM and ONOO- changes, and revealing their interplay in AAA. BH-Vis precisely targets CPM with reduced red fluorescence intensity correlating with diminished CPM tension. Concurrently, a blue shift of the fluorescence signal of BH-Vis occurs in response to ONOO- offering a reliable ratiometric detection mode with enhanced accuracy by minimizing external testing variables. More importantly, two photon confocal imaging with palmitic acid (PA) and ganglioside (GM1) manipulation, which modulating cell pyroptosis, showcases reliable fluorescence fluctuations. This groundbreaking application of BH-Vis in a mouse AAA model demonstrates its significant potential for accurately identifying cell pyroptosis levels during AAA development.

Recent Achievements for Flexible Encapsulation Films Based on Atomic/Molecular Layer Deposition.

The purpose of this paper is to review the research progress in the realization of the organic-inorganic hybrid thin-film packaging of flexible organic electroluminescent devices using the PEALD (plasma-enhanced atomic layer deposition) and MLD (molecular layer deposition) techniques. Firstly, the importance and application prospect of organic electroluminescent devices in the field of flexible electronics are introduced. Subsequently, the principles, characteristics and applications of PEALD and MLD technologies in device packaging are described in detail. Then, the methods and process optimization strategies for the preparation of organic-inorganic hybrid thin-film encapsulation layers using PEALD and MLD technologies are reviewed. Further, the research results on the encapsulation effect, stability and reliability of organic-inorganic hybrid thin-film encapsulation layers in flexible organic electroluminescent devices are discussed. Finally, the current research progress is summarized, and the future research directions and development trends are prospected.

Exploration of Polysaccharides from Phyllanthus emblica: Isolation, Identification, and Evaluation of Antioxidant and Anti-Glycolipid Metabolism Disorder Activities.

Phyllanthus emblica is a natural medicinal herb with diverse bioactivities. Certain extracts from this herb have been confirmed to possess anti-glycolipid metabolic disorder activity. To further develop its utility value and explore its potential in combating glycolipid metabolic disorders, we designed a series of experiments to investigate the structure, antioxidant activity, and anti-glycolipid metabolic disorder activity of Phyllanthus emblica polysaccharides. In this study, we extracted and purified polysaccharides from Phyllanthus emblica and thoroughly analyzed their structure using various techniques, including NMR, methylation analysis, and surface-enhanced Raman spectroscopy. We investigated the hypolipidemic and anti-glycolipid metabolism disorder activity of Phyllanthus emblica polysaccharides for the first time utilizing oleic acid (OA) and advanced glycation end products (AGEs) as inducers. Additionally, the antioxidant activity of Phyllanthus emblica polysaccharides was assessed in vitro. These findings lay the groundwork for future investigations into the potential application of Phyllanthus emblica polysaccharides as an intervention for preventing and treating diabetes.

High-Sensitivity Seawater Refraction Index Optical Measurement Sensor Based on a Position-Sensitive Detector.

The refractive index of seawater is one of the essential parameters in ocean observation, so it is necessary to achieve high-precision seawater refractive index measurements. In this paper, we propose a method for measuring the refractive index of seawater, based on a position-sensitive detector (PSD). A theoretical model was established to depict the correlation between laser spot displacement and refractive index change, utilizing a combination of a position-sensitive detector and laser beam deflection principles. Based on this optical measurement method, a seawater refractive index measurement system was established. To effectively enhance the sensitivity of refractive index detection, a focusing lens was incorporated into the optical path of the measuring system, and simulations were conducted to investigate the impact of focal length on refractive index sensitivity. The calibration experiment of the measuring system was performed based on the relationship between the refractive index of seawater and underwater pressure (depth). By measuring laser spot displacement at different depths, changes in displacement, with respect to both refractive index and depth, were determined. The experimental results demonstrate that the system exhibits a sensitivity of 9.93×10-9 RIU (refractive index unit), and the refractive index deviation due to stability is calculated as ±7.54×10-9 RIU. Therefore, the feasibility of this highly sensitive measurement of seawater refractive index is verified. Since the sensitivity of the refractive index measurement of this measurement system is higher than the refractive index change caused by the wake of underwater vehicles, it can also be used in various applications for underwater vehicle wake measurement, as well as seawater refractive index measurement, such as the motion state monitoring of underwater navigation targets such as AUVs and ROVs.

UAV and Satellite Synergies for Mapping Grassland Aboveground Biomass in Hulunbuir Meadow Steppe.

Aboveground biomass (AGB) is an important indicator of the grassland ecosystem. It can be used to evaluate the grassland productivity and carbon stock. Satellite remote sensing technology is useful for monitoring the dynamic changes in AGB across a wide range of grasslands. However, due to the scale mismatch between satellite observations and ground surveys, significant uncertainties and biases exist in mapping grassland AGB from satellite data. This is also a common problem in low- and medium-resolution satellite remote sensing modeling that has not been effectively solved. The rapid development of uncrewed aerial vehicle (UAV) technology offers a way to solve this problem. In this study, we developed a method with UAV and satellite synergies for estimating grassland AGB that filled the gap between satellite observation and ground surveys and successfully mapped the grassland AGB in the Hulunbuir meadow steppe in the northeast of Inner Mongolia, China. First, based on the UAV hyperspectral data and ground survey data, the UAV-based AGB was estimated using a combination of typical vegetation indices (VIs) and the leaf area index (LAI), a structural parameter. Then, the UAV-based AGB was aggregated as a satellite-scale sample set and used to model satellite-based AGB estimation. At the same time, spatial information was incorporated into the LAI inversion process to minimize the scale bias between UAV and satellite data. Finally, the grassland AGB of the entire experimental area was mapped and analyzed. The results show the following: (1) random forest (RF) had the best performance compared with simple regression (SR), partial least squares regression (PLSR) and back-propagation neural network (BPNN) for UAV-based AGB estimation, with an R2 of 0.80 and an RMSE of 76.03 g/m2. (2) Grassland AGB estimation through introducing LAI achieved higher accuracy. For UAV-based AGB estimation, the R2 was improved by an average of 10% and the RMSE was reduced by an average of 9%. For satellite-based AGB estimation, the R2 was increased from 0.70 to 0.75 and the RMSE was decreased from 78.24 g/m2 to 72.36 g/m2. (3) Based on sample aggregated UAV-based AGB and an LAI map, the accuracy of satellite-based AGB estimation was significantly improved. The R2 was increased from 0.57 to 0.75, and the RMSE was decreased from 99.38 g/m2 to 72.36 g/m2. This suggests that UAVs can bridge the gap between satellite observations and field measurements by providing a sufficient training dataset for model development and AGB estimation from satellite data.

Alterations of intestinal mucosal barrier, cecal microbiota diversity, composition, and metabolites of yellow-feathered broilers under chronic corticosterone-induced stress: a possible mechanism underlying the anti-growth performance and glycolipid metabolism disorder.

This study aimed to explore alterations in growth performance, glycolipid metabolism disorders, intestinal mucosal barrier, cecal microbiota community, and metabolites in a chronic corticosterone (CORT)-induced stress (CCIS) broiler model. Results showed that compared with control (CON) broilers, in CCIS broilers: (i) the final body weight (BW), BW gain, and average daily gain were significantly reduced. (ii) The glycolipid metabolism disorder and impairement of intestinal immune barrier and physical barrier function were observed. (iii) Diversity and richness of cecal microbiota were obviously increased. From phylum to genus level, the abundances of Firmicutes and Faecalibacterium were significantly decreased, while the abundances of Proteobacteria, RuminococcaceaeUCG-005, and Escherichia coli (Shigella) were significantly increased. Microbial network analysis and function pathways prediction showed that cecal microbiota was mainly concentrated in translation, metabolism, nucleotide metabolism, and endocrine system. (iv) The main differential metabolites identified include steroids and their derivatives, amino acids, fatty acids, and carbohydrates; among which 37 metabolites were significantly upregulated, while 27 metabolites were significantly downregulated. These differential metabolites were mainly enriched in pathways related to steroid hormone biosynthesis and tyrosine metabolism. (v) Correlation between cecal microbiota and glycolipid metabolism indexes showed that BW and total cholesterol (TC) were positively correlated with Christensenellaceae_R.7_group and Escherichia_Shigella, respectively. Furthermore, the downregulated Faecalibacterium and Christensenellaceae were negatively correlated with the upregulated differentially expressed metabolites. These findings suggested that CCIS altered cecal microbiota composition and metabolites, which led to glycolipid metabolism disorder and impaired the nutritional metabolism and immune homeostasis, providing a theoretical basis for efforts to eliminate the harm of chronic stress to human health and animal production. IMPORTANCE: The study aimed to determine the influence of altered intestinal mucosal barrier, cecum flora community, and metabolites on anti-growth performance, glycolipid metabolism disorders of chronic corticosterone (CORT)-induced stress (CCIS) broilers. Compared with control (CON) broilers, in CCIS broilers: (i) anti-growth performance, glycolipid metabolism disorder, and impaired intestinal immune barrier and physical barrier function were observed. (ii) From phylum to genus level, the abundances of Firmicutes and Faecalibacterium were decreased; whereas, the abundances of Proteobacteria, RuminococcaceaeUCG-005, and Escherichia coli (Shigella) were increased. (iii) Differential metabolites in cecum were mainly enriched in steroid hormone biosynthesis and tyrosine metabolism. (iv) Body weight (BW) and total cholesterol (TC) were positively correlated with Christensenellaceae_R.7_group and Escherichia_Shigella, respectively, while downregulated Faecalibacterium and Christensenellaceae were negatively correlated with upregulated metabolites. Our findings suggest that CCIS induces anti-growth performance and glycolipid metabolism disorder by altering cecum flora and metabolites, providing a theoretical basis for efforts to eliminate the effect of chronic stress on human health and animal production.