Search Results (345)

The incidental discovery of focal liver lesions (FLLs) has reached unprecedented levels due to the widespread use of high-resolution imaging, yet unenhanced ultrasound often lacks the specificity required for definitive characterization. This review identifies Contrast-Enhanced Ultrasound (CEUS) as a transformative diagnostic pillar for common benign focal liver lesions (BFLLs). By utilizing strictly intravascular second-generation microbubble agents, CEUS enables continuous, real-time visualization of microvascular hemodynamics. This high temporal resolution allows clinicians to identify pathognomonic vascular signatures, such as the “iris-diaphragm” centripetal fill-in of hemangiomas and the rapid centrifugal “spoke-wheel” hyperperfusion characteristic of focal nodular hyperplasia (FNH). Critically, this review highlights the unparalleled safety profile of CEUS. Because microbubbles are not excreted by the kidneys and carry no risk of nephrotoxicity, CEUS is an essential diagnostic option for patients with renal failure. Furthermore, the lack of ionizing radiation and the ability to perform examinations bedside provide a safe and versatile solution for pregnant patients and those with contraindications to traditional cross-sectional imaging. This review serves as a comprehensive informational framework, equipping clinicians with detailed pathological, clinical, and radiological insights into common entities like hemangiomas, FNH, and hepatocellular adenomas (HCA). It correlates fundamental histological features—such as the “map-like” glutamine synthetase staining in FNH—with essential clinical management strategies. While multiparametric MRI remains the premier tool for complex subtyping and molecular mapping—particularly for differentiating hepatocellular adenoma variants—CEUS is established as a cost-effective and radiation-free initial diagnostic solution. This review equips clinicians with a comprehensive framework of pathological, clinical, and radiological insights to optimize the management of common benign hepatic incidentalomas. Full article

Excessive nitrogen (N) input and repeated shallow tillage constrain sustainable winter wheat production in the North China Plain. A two-year field experiment was conducted to compare rotary tillage, subsoiling, and no-tillage under N application rates of 120, 180, and 240 kg ha⁻¹. Subsoiling generally increased grain yield, with yields under subsoiling at 180 kg N ha⁻¹ (SN180) reaching 8129.64 and 7700.89 kg ha⁻¹ in the two growing seasons, respectively, without significant differences from SN240, while reducing N input by 60 kg ha⁻¹. SN180 favored post-anthesis dry matter accumulation and post-anthesis N uptake. Accordingly, it achieved partial factor productivity of applied N of 45.16 and 42.78 kg kg⁻¹, and N uptake efficiencies ranging from 1.29 to 1.46 kg kg⁻¹, which were higher than those under SN240 and other tillage practices at the same N rate. In 2023–2024, SN180 increased root length density at 20–40 cm by 41.8% and 59.7% and root dry weight density by 22.0% and 20.5% compared with rotary tillage and no-tillage, respectively. SN180 also maintained relatively high nitrate reductase and glutamine synthetase activities during the same growing season, although the responses varied among plant organs and growth stages. Under the conditions of this two-year field experiment, subsoiling combined with 180 kg N ha⁻¹ achieved the most favorable balance between grain yield and N use performance among the treatments tested, indicating its potential as a management option for irrigated winter wheat production in the North China Plain. Full article

Saline irrigation is a major constraint on vegetation establishment in arid coal-mining landscapes. Nitraria tangutorum Bobrov is a xerohalophytic shrub established in the Dananhu mine-restoration area of Hami, Xinjiang, but its physiological responses to long-term saline irrigation remain insufficiently characterized. In this field study, approximately two-year-old plants were maintained for approximately two growing seasons under freshwater drip irrigation or irrigation water containing 8 or 12 g L⁻¹ total dissolved solids. Unlike short-term controlled salinity assays that evaluate individual response pathways, the present field study integrates root and shoot responses across osmolyte accumulation, oxidative injury, redox regulation, nitrogen metabolism, phytohormone signaling, and lipid remodeling under long-term mixed-salt irrigation. Increasing salinity significantly reduced shoot total chlorophyll content, whereas shoot carotenoid content showed a nonsignificant numerical increase. Soluble sugars, proline, and soluble proteins increased, while total free amino acids declined. Superoxide anion (O₂⁻), hydrogen peroxide (H₂O₂), and malondialdehyde (MDA) increased progressively, demonstrating oxidative injury. The protein concentrations of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) increased, whereas glutathione peroxidase (GSH-PX) and glutathione reductase (GR) declined. Concurrent decreases in ascorbic acid/ascorbate (AsA) and reduced glutathione (GSH), together with increases in dehydroascorbic acid (DHA) and oxidized glutathione (GSSG), indicated progressive oxidation of the cellular redox environment. Nitrate reductase (NR) declined under salinity, while glutamine synthetase (GS) and glutamate synthase (GOGAT) increased at 8 g L⁻¹ but decreased at 12 g L⁻¹. Growth-associated hormones declined, whereas stress-associated hormones increased. Together, these responses reveal a dose-dependent transition from co-occurring biochemical adjustment and oxidative injury at 8 g L⁻¹ to broader redox and metabolic disruption at 12 g L⁻¹ under long-term field irrigation. These variables provide candidate indicators of downstream salinity response, but ion homeostasis, plant water status, growth, survival, and long-term performance must be evaluated before salt tolerance or irrigation thresholds can be established. Full article

Liriomyza trifolii is a global pest of vegetables and ornamental plants and a major invasive species in China. Long-term irrational use of chemical insecticides has reduced control efficacy, driving interest in plant-derived alternatives. Bitter gourd, Momordica charantia, extracts show potential against various pests, but their effects on L. trifolii are unknown. To address this, host suitability tests were first conducted and revealed that L. trifolii exhibited significantly higher adaptability to kidney bean than to bitter gourd in terms of both oviposition and feeding, and failed to complete its life cycle on bitter gourd. Further treatment with ethanol extracts of bitter gourd leaves demonstrated dose-dependent adulticidal activity; at the LC₅₀ concentration, the extract not only reduced feeding punctures and oviposition, but also significantly decreased egg hatching and larval survival, while showing no significant impact on pupation or emergence. To elucidate the underlying molecular mechanisms, integrative transcriptomic and metabolomic analyses were subsequently performed. Transcriptomics identified 254 differentially expressed genes (DEGs) enriched in ribosome, oxidative phosphorylation, and peroxisome pathways, and upregulated DEGs included a vitellin-degrading protease and cytochrome P450. Meanwhile, metabolomics detected 272 differential metabolites (DEMs): upregulated metabolites were linked to purine metabolism, while downregulated ones were associated with cysteine/methionine and arginine/proline metabolism. Integrated analysis revealed “Biosynthesis of amino acids” as the sole common pathway, with S-adenosyl-L-homocysteine, N-succinyl-LL-2,6-diaminoheptanedioate, and glutamine synthetase (Ltr05G008090) showing significant correlations. These findings suggest that reprogramming of amino acid and nitrogen metabolism may participate in the response and could serve as a candidate response pathway. Accordingly, this study may offer a theoretical basis for the future development of botanical insecticides based on bitter gourd leaf extract against L. trifolii. Full article

Sorghum (Sorghum bicolor (L.) Moench) is an important crop with remarkable tolerance to adverse environments, including nitrogen deficiency. To investigate the mechanisms underlying sorghum tolerance to low-nitrogen (LN) stress, we integrated phenotypic evaluation, transcriptome profiling, weighted gene co-expression network analysis (WGCNA), and haplotype analysis. Two accessions, the LN-tolerant ‘Liaonian B-1’ and the LN-sensitive ‘Yikeerli’, were examined under hydroponic and field conditions. Under LN conditions, Liaonian B-1 showed increases of 32% in root length, 4.3-fold in root fresh weight, and 91% in root dry weight, whereas the LN-sensitive accession showed severe reductions in shoot biomass and a decrease in root fresh weight, with root dry weight remaining relatively stable. Transcriptomic analysis revealed more shared differentially expressed genes and stronger enrichment of N metabolism pathways in shoots, whereas roots showed enrichment of ATP-binding cassette (ABC) transporter and fatty acid elongation pathways. WGCNA identified 500 hub genes in roots and shoots. Five genes in the glutamine synthetase/glutamate synthase (GS-GOGAT) pathway were significantly associated with nitrogen-related traits. SORBI_3001G116400, which encodes glutamate synthase, showed the strongest haplotype effect in 232 sorghum accessions. The A allele (Hap1) was significantly associated with increased plant height, SPAD value, grain number, nitrogen accumulation, and biomass under LN stress, suggesting that SORBI_3001G116400 as a candidate gene requiring functional validation and testing in additional genetic backgrounds. Full article

Water and nitrogen application rates directly affect crop yield formation and protein accumulation. Nitrogen metabolism, as a key physiological process linking water and nitrogen supply with crop growth, plays a critical role in regulating nitrogen uptake, transformation, and accumulation. However, the functional relationships among different nitrogen metabolism indicators in mediating the formation of high-quality and high-yield alfalfa under water–nitrogen regulation remain unclear. In this study, alfalfa (Medicago sativa L.) was subjected to four nitrogen application levels [N0 (0 kg·hm⁻²), N1 (80 kg·hm⁻²), N2 (160 kg·hm⁻²), N3 (240 kg·hm⁻²)] and four irrigation gradients [severe deficit (W0, 45–60% θ_f), moderate deficit (W1, 55–70% θ_f), mild deficit (W2, 65–80% θ_f), and full irrigation (W3, 75–90% θ_f), where θ_f represents field capacity]. The relationships between water–nitrogen regulation and alfalfa nitrogen metabolism and productive performance were analyzed. The results showed that (1) both irrigation amount and nitrogen application rate significantly affected the activities of leaf nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase (GOGAT), and soluble protein (SP) content (p < 0.05). Aboveground nitrogen content (TN) initially increased and then decreased with increasing irrigation and nitrogen application, reaching its maximum under W2N2, with leaves being the primary site of aboveground nitrogen accumulation. (2) Under W2N2, alfalfa yield and crude protein accumulation (CP-a) both reached their maximum values, averaging 10.22 t·ha⁻¹ and 1187.10 kg·ha⁻¹, respectively. (3) Structural equation modeling (SEM) indicated that water–nitrogen regulation primarily influenced yield and CP-a formation through its effects on GS activity and TN. Based on these findings, a comprehensive evaluation model (GS–TN–Yield–CP-a) was constructed, and the preliminary suitable water–nitrogen regulation ranges for high-quality and high-yield alfalfa were identified as an irrigation amount of 69.4–85.9% θ_f and a nitrogen application rate of 102.6–222.3 kg·hm⁻². These results can provide a theoretical basis for high-quality and high-yield alfalfa management in arid and semi-arid regions, but further verification through field experiments is still required. Full article

Balancing high grain yield with improved nitrogen use efficiency is a critical challenge in intensive rice production systems. Although both nitrogen application rate and planting density are recognized as major determinants of yield, their synergistic physiological mechanisms, particularly in large-panicle Indica–Japonica hybrid rice, remain insufficiently understood. A two-year (2023–2024) split-plot field experiment was conducted using the high-yield cultivar Yongyou 7860. Treatments included five nitrogen application rates (N0: 0; N12: 180; N14: 224; N16: 240; N20: 300 kg ha⁻¹) and three planting densities (D1: 220,000; D2: 190,000; D3: 160,000 plants ha⁻¹). Grain yield, yield components, canopy chlorophyll status (SPAD value), dry matter accumulation, partial factor productivity of nitrogen, and activities of glutamine synthetase (GS) and glutamate synthase (GOGAT) at critical growth stages were determined. Nitrogen rate and planting density exhibited significant interactive effects on grain yield and nitrogen use efficiency. Grain yield increased with nitrogen application rate but showed a quadratic response to planting density, with an optimum at the medium density. The N16D2 treatment consistently achieved 11.3–11.8 t/ha over two years, exceeding conventional practices by 1.7–9.7%, primarily attributed to a 6.3–11.5% increase in the number of effective panicles. Physiologically, N16D2 sustained higher SPAD values and dry matter accumulation comparable to excessive nitrogen input, while enhancing the partial factor productivity of nitrogen by 33.0% relative to N20D3. Enhanced activities of GS and GOGAT under N16D2 indicated improved nitrogen assimilation capacity. In summary, reduced nitrogen application coordinated with increased planting density optimizes canopy structure, promotes efficient nitrogen metabolism, and sustains high grain yield in Indica–Japonica hybrid rice. This study provides a scientifically grounded and practically applicable strategy for achieving high productivity with improved nitrogen use efficiency in intensive rice systems. Full article

To address water scarcity, environmental pollution from excessive fertilization, and the need for stable grain yields in the North China Plain (NCP), a 3-year field experiment (2021–2024) was conducted to explore the effects of water and nitrogen (N) management under subsurface drip irrigation on winter wheat–summer maize rotation system. This study included three irrigation treatments (irrigated to 80% (D1), 75% (D2), and 70% (D3) of field water-holding capacity (WHC) when soil water content dropped below 65%, 60%, and 55% of WHC, respectively) under N210 and four N application rates (0 (N0), 150 (N150), 210 (N210), and 270 (N270) kg N ha⁻¹ for each season) under D1. The results showed that D1 and N210 all significantly improved leaf area index (LAI) and aboveground biomass by reducing chlorophyllase and pheophytinase activities (delaying leaf senescence) and enhancing nitrate reductase (NR), glutamine synthetase (GS), and glutamate synthase (GOGAT) activities (promoting N assimilation). Furthermore, compared with D3, D1 increased winter wheat and summer maize yields by 12.7% and 24.3%, respectively, and improved partial factor productivity (PFP) by 14.0–46.0%. Redundancy analysis (RDA) and structural equation modeling confirmed that LAI, biomass, and N-transforming enzyme activities were the key drivers of yield. This study demonstrated that the combination of D1 and N210 treatments were the optimal water and N fertilizer management strategies for achieving water conservation, N reduction, and stable high yields in drip-irrigated rotation systems of the NCP. Full article

To induce embryogenic callus from Pinus thunbergii vegetative organs, and deeply understand the internal mechanism of the process, an orthogonal experimental design of three factors and four levels and proteome analysis were adopted. The results showed that the optimal medium was douglas-fir cotyledon medium (DCR), containing 2.5 mg L⁻¹ 2-4-dichlorophenoxyacetic acid (2,4-D) and 1.0 mg L⁻¹ 6-benzylaminopurine (6-BA), 0.3 g L⁻¹ polyvinylpyrrolidone (PVP), 0.5 g L⁻¹ acid casein hydrolysate (CH), 0.5 g L⁻¹ L-glutamine, 1.0 g L⁻¹ inositol, 6.0 g L⁻¹ agar and 20.0 g L⁻¹ sucrose. Microscopic examinations revealed a distinct embryogenic-like callus (EC) structure, and these ECs finally achieved redifferentiation. Analysis of the interactions between factors detected that although the 6-BA concentration alone was not significant, it became a significant effect factor when interacted with 2,4-D (p < 0.05). Peroxidase (POD), superoxide dismutase (SOD) and soluble sugar (SS) of EC were significantly higher than those of non-embryogenic callus (NEC), and label-free quantitative proteomics analysis showed that different types of PODs including peroxidase 4, phospholipid hydroperoxide glutathione peroxidase, and cationic peroxidase 1 in EC were significantly up-regulated, and they were involved in antioxidant biological processes, located in the intercellular region, and performed molecular functions such as heme binding, so POD was a suitable and stable physiological marker for EC. Four up-regulated proteins in EC included glutathione S-transferase, chalcone flavanone isomerase, phosphoenolpyruvate carboxykinase and endoglucanase. Five EC-specific proteins included indole-3-acetic acid-amido synthetase GH3.1, indole-3-acetate O-methyltransferase 1-like, cytokinin dehydrogenase, MLP-like protein 423 and 2-methoxy-6-polyprenyl-1,4-benzoquinol methylase. These proteins are also potential EC molecular markers. Among these proteins, glutathione S-transferase is beneficial to prevent cell death in EC, while indole-3-acetate O-methyltransferase 1-like and cytokinin dehydrogenase are beneficial to promote EC redifferentiation. Full article

Water-soluble blue microbial pigments with antioxidant activity remain rare, and their host-level protective mechanisms are poorly understood. Here, we identified the genetic basis of blue pigment biosynthesis in the glacier-derived strain Arthrobacter antioxidans QL17. Heavy-ion mutagenesis yielded a hyperpigmented mutant (M157) and a pigment-deficient mutant (M186), and pigment yield was positively associated with hydrogen peroxide (H₂O₂) tolerance. Genome mining identified MWM45_RS16760 as the sole core biosynthetic gene in a candidate nonribosomal peptide synthetase (NRPS)-like cluster. The encoded protein displayed an adenylation–peptidyl carrier protein–thioesterase (A-PCP-TE) architecture with a predicted L-glutamine-specific A domain, and its transcript abundance paralleled pigment production across the three strains. Phylogenetic analysis placed MWM45_RS16760 in a distinct actinomycete-associated indigoidine-like lineage separated from the characterized BpsA and IndC branches. Heterologous expression in Escherichia coli reconstructed a blue-pigment-producing phenotype, increased H₂O₂ tolerance, and was accompanied by enhanced extracellular DPPH and ABTS radical-scavenging activities in the culture supernatant. Comparative transcriptomics further revealed coordinated activation of oxidative-stress and proteostasis responses alongside repression of tryptophan biosynthesis and flagellar assembly. These findings identify MWM45_RS16760 as a candidate indigoidine-like NRPS associated with blue pigment biosynthesis and oxidative-stress resistance, with heterologous expression linked to enhanced radical scavenging and coordinated transcriptional reprogramming, expanding the phylogenetic and functional diversity of indigoidine-like systems. Full article

Microbial protein production from acetate represents a promising route for sustainable protein supply, yet its efficiency is constrained by limited understanding of carbon–nitrogen metabolic coordination. In this study, nitrogen availability was systematically varied to investigate its role in regulating biomass composition and protein biosynthesis in Yarrowia lipolytica. Nitrogen limitation markedly reduced cell growth and protein accumulation (19.56% of dry cell weight) while increasing lipid content (up to 34.16%), indicating a altered protein and lipid accumulation under different nitrogen conditions. Transcriptomic analysis revealed a global downregulation of anabolic pathways under nitrogen limitation, accompanied by a shift in nitrogen assimilation from the glutamate dehydrogenase (GDH) pathway to the glutamine synthetase/glutamate synthase (GS–GOGAT) pathway, as well as significant upregulation of genes related to ammonium and amino acid transport. Guided by these findings, metabolic engineering of key nitrogen assimilation pathways was performed. Strains harboring additional copies of GDH and GS expression cassettes showed increased protein content from 48.52% to 55.77% and improved amino acid composition, whereas strains with an additional copy of the GOGAT gene exhibited reduced growth and protein accumulation. These results demonstrate that nitrogen availability regulates biomass composition through coordinated control of nitrogen transport and assimilation, and that balanced upregulation of GDH and GS genes is an effective strategy to improve microbial protein production from acetate, supporting the development of efficient fermentation processes using low-cost carbon sources. Full article

The present study aimed to evaluate the role of ascorbic acid in alleviating ammonia-induced muscle quality deterioration and to clarify its regulatory effects on apoptosis, texture, and flavor-related metabolites in rainbow trout (Oncorhynchus mykiss). The results demonstrated that ascorbic acid alleviated ammonia stress-induced inflammatory and apoptotic damage by regulating toll like receptor 5 (TLR5), myeloid differentiation primary response 88 (MyD88), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) expression, thereby contributing to the restoration of myofibrillar integrity, reduced extracellular gaps, and increased shear force from 14.18 N to 18.26 N (p < 0.05). Ascorbic acid modulated ammonia handling and ion-exchange responses by upregulating glutamine synthetase (GS) expression from approximately 2.3-fold to 6.7-fold and increasing ornithine and citrulline accumulation. Alterations in tricarboxylic acid cycle-related metabolites further suggested that energy metabolism may be involved in the physiological adaptation to ammonia stress. Meanwhile, the ascorbic acid reduced the accumulation of key off-flavor compounds (1-octene-3-alcohol and (E)-2-nonenal), attenuating the earthy–moldy and fishy flavor. This research proposes a potential strategy to improve muscle quality in live transportation. Full article

Agaricus bisporus (A. bisporus) is susceptible to rapid postharvest deterioration. Although elevated CO₂ (6%) delays senescence, the metabolic mechanisms remain unclear. In this study, untargeted and targeted metabolomic analyses were employed to explore these pathways in A. bisporus. The results revealed that elevated CO₂ treatment promoted glycolysis by upregulating Hexokinase (HK), Phosphofructokinase (PFK), and Pyruvate Kinase (PK), accumulating Glucose-6-phosphate (G-6-P) and Fructose-6-phosphate (F-6-P). Concurrently, elevated CO₂ treatment upregulated the expression of genes associated with the tricarboxylic acid (TCA) cycle and increased the enzymatic activities of Malate Dehydrogenase (MDH) and Fumarate hydratase (FUM). These changes led to the rapid consumption of key intermediate metabolites (Fumarate (Fum), Malate (Mal), and α-Ketoglutarate (α-KG)), collectively enhancing the efficiency of the TCA cycle. Furthermore, elevated CO₂ treatment significantly suppressed the activities of Glutamine Synthetase (GS) and Xanthine Oxidase (XOD), inhibiting the synthesis of Glutamine (Gln) and Pyroglutamate (pGlu) while promoting the accumulation of Hypoxanthine (Hx). This coordinated reprogramming of amino acid metabolism and purine metabolism contributed to improved energy efficiency and enhanced cellular integrity in postharvest A. bisporus. This study elucidates the specific mechanism by which elevated CO₂ levels regulate the postharvest energy metabolism of A. bisporus from a metabolomics perspective, providing a theoretical basis for developing strategies to control its postharvest quality. Full article

Choline-based ionic liquids (ILs) have emerged as promising candidates for application in multifaceted avenues, including electrochemistry, biomaterials, and environmental remediation technologies. However, their regulatory effects on the growth of agricultural plants have rarely been discussed. In this study, 14 choline–fatty acid ILs ([Chl][FA] ILs) containing different FA anions were synthesized, and their effects on the maize growth were investigated. Hydroponic experiments revealed that low concentrations (20 mg/L) of dicarboxylic acid-based [Chl][FA] ILs (e.g., choline pentane diacid [Chl][Pent]) significantly promoted maize root and shoot biomass, whereas higher concentrations inhibited it. Specifically, [Chl][Pent] enhanced chlorophyll content without altering Fv/F₀, upregulated nitrate reductase (NR) and glutamine synthetase (GS) activities, and stimulated the expression of key nitrogen metabolism (NR and GS) and photosynthetic (Rubisco) genes. Pathway analyses of differentially expressed genes indicated that [Chl][Pent] was associated with the upregulation of nitrogen and glycerophospholipid metabolism. [Chl][Pent] increased the average grain yield by 6.88% over two years compared to CK. Field application of [Chl][Pent] increased grain yield and protein accumulation relative to both control and choline chloride treatments. Overall, these findings demonstrate the potential of dicarboxylic acid-based [Chl][FA] ionic liquids as eco-friendly biostimulants for enhancing crop growth, yield, and quality. Full article

Background/Objectives: tRNAs, tRNAomes, aminoacyl-tRNA synthetases (AARSs), the first proteins, ribosomes and the genetic code coevolved. We utilize sequence data to reconstruct key steps in establishing the first code on Earth. Methods: Networks were constructed to describe initial tRNAome and AARSome evolution. Results: tRNA-34 wobble and tRNA-37 modifications were necessary to evolve the code, as were additional tRNA modifications, so diverse tRNA modification enzymes (i.e., histidyl-tRNA -1 GTP synthase) are among the first proteins. tRNA-linked chemistry brought asparagine, glutamine, cysteine and possibly additional amino acids into the code. tRNA, tRNA modifications and tRNA-linked chemistry were core founding innovations for code evolution. Coevolution of AARSomes was also essential. Class II and class I AARSs have distinct folds but are nonetheless homologs by sequence. Early AARS enzymes folded around Zn motifs. Networks were generated for tRNAomes and AARSomes in ancient Archaea, because Archaea are the closest living organisms to the last universal common ancestor. Conclusions: The first code on Earth was surprisingly ordered, and the few apparent deviations from the regular order can yet be explained. Early in the evolution of the code, innovation was more strongly selected than accuracy. The code froze, however, because of evolving fidelity mechanisms. A historical record was documented in tRNA and in the genetic code structure and has been preserved in living organism sequences. AARSome structure describes the first code evolution more adequately than tRNAomes. Full article