Search Results (2,558)

Artificial intelligence (AI)-based structure prediction tools have emerged as powerful methods for understanding previously unsolved structures. AI-predicted models are widely used for protein function identification, drug development, and protein engineering. Although AI-predicted structures offer significant opportunities to advance research, their inaccuracies can lead to misinterpretations of molecular mechanisms. Thus, evaluating the structural differences between AI-predicted and experimental structures is crucial for accurately understanding molecular mechanisms and guiding the design of subsequent experiments. In this study, the previously unreported crystal structure of xylanase from Hypocrea virens (HviGH11) was compared with the structures predicted by ESMFold, AlphaFold2, AlphaFold3, and RoseTTAFold. The overall fold of HviGH11 was highly similar between the experimental and AI-predicted models; however, the conformation of the thumb domain of the protein varied across the models. The substrate-binding cleft of experimental HviGH11 was similar to that in the model structures generated by ESMFold, AlphaFold2, and AlphaFold3, but significantly different from those in the model structures generated by RoseTTAFold. The substrate docking study illustrated that the binding mode of xylohexaose in the substrate-binding cleft differed between the experimental and AI-predicted HviGH11 structures. These findings provide insights into the applications of AI-predicted models and offer guidance for appropriate application in structural and functional studies and biotechnology. Full article

Urbanization in mountainous regions alters hydrologic systems, yet the spatial patterning of residential (RA) and non-residential (NRA) areas in response to hydrologic constraints remains poorly quantified. In this study, we analyzed how such constraints shaped the distinct locational logic of RA and NRA expansion in the mountainous Kunming Core Region (KCR), Southwest China, from 1975 to 2020. Using the Global Human Settlement Layer (GHS-BUILT-S) built-up fraction data and its functionally classified RA and NRA layers at 100 m resolution, we quantified multi-decadal urban land changes via regression and centroid migration analyses. Six hydrologic factors, namely altitude, slope, surface roughness, distance to river (DTR), depth to water table (DTWT) and vegetation root depth (VRD), were derived from global terrain, groundwater, and rooting depth datasets, and harmonized to a common grid. Results show a two-phase urbanization pattern: moderate, compact growth before 1995 followed by rapid, near-exponential expansion, dominated by RA. RA consistently clustered in hydrologically favorable zones (low–moderate roughness, mid-altitudes, lower slopes, proximal rivers, shallow–moderate DTWT, moderate VRD), whereas NRA expanded into more hydrologically variable terrain (higher roughness, intermediate DTR, deeper DTWT, higher altitudes, deeper VRD). Contribution-weighting analysis revealed a temporal shift in dominant drivers: for RA, from river proximity and slope in 1975 to terrain roughness in 2020; for NRA, from vegetation root depth and moderate topography to root depth plus altitude. Geographic centroids of both RA and NRA migrated northeastward, indicating coordinated yet functionally distinct peri-urban and corridor-oriented growth. These findings provide a hierarchical, factor-based framework for integrating hydrologic constraints into risk-informed land-use planning in topographically complex basins. Full article

Cotton is an important cash crop globally. Cotton fiber is the main economic product of cotton plants. Phosphorus, as one of the essential nutrients, plays an important role in plant growth and development. However, few studies focus on phosphorus regulating fiber elongation. In this study, we used the cotton ovule culture system in vitro to explore the effects of various phosphorus levels on fiber and ovule growth, and screened for phosphorus-responsive factor, as well as revealed its action mechanism. The results indicated that fiber elongation was more sensitive than ovule growth to phosphorus deficiency. GhPHR1, a homolog of phosphate starvation response 1 (PHR1) in upland cotton, was significantly upregulated in fibers and ovules under phosphorus-deficient conditions. GhPHR1 directly binds to the promoter of the glucosylceramide synthase gene in cotton (GhGCS1) and positively regulates its expression. Overexpressing GhGCS1 enhanced phosphorus uptake and transport in cotton, increased phosphorus content in fiber cells, and promoted fiber cell elongation. Conversely, downregulating GhGCS1 reduced phosphorus content in fiber cells and suppressed fiber elongation. These findings demonstrate the importance of the GhPHR1-GhGCS1 molecular module in regulating fiber cell elongation and elucidate the molecular mechanism by which phosphorus influences fiber elongation. Full article

Myosin XI-K plays an important role in cell expansion and polarized growth, acting as a motor protein that drives organelle trafficking and cytoplasmic streaming. To elucidate the molecular mechanisms of myosin XI-K’s role in the polarized growth of cotton fiber, we investigated the interactions between GhXI-K and Rab GTPases in cotton (Gossypium hirsutum). Protein docking analyses based on AlphaFold3 predicted that GhXI-K interacted with eight Rab GTPases. A total of 37 interaction residues were identified in GhXI-K, of which 5 crucial contact residues were located in the globular tail domain (GTD) and 2 were located in the motor domain. Key interaction residues in the Rab GTPases were also found to be located in conserved regions: switch-I and switch-II. Yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays confirmed the predictions and showed that these interactions occur primarily in the GTD and the motor domain. Our findings reveal that GhXI-K interacts with Rab GTPases through both the motor and tail domains, suggesting a synergistic mechanism that facilitates polarized vesicle trafficking in cotton fiber cells. Full article

Targeted synthesis of Ni/C-containing composite materials was carried out using the matrix isolation method. The Ni content was varied (5–20 wt.% from chitosan). The morphology and physicochemical properties of the obtained materials were characterized using a number of methods: elemental analysis, SEM, TEM, XRD, FTIR, Raman spectroscopy, TPR–H₂, and SSA. FTIR showed that nickel ions are immobilized on the chitosan molecule, and heat treatment of the polymer molecule results in the formation of polyconjugation centers. It was also revealed that heat treatment of the salt–polymer films results in the formation of a graphite-like structure (Raman spectroscopy) with the inclusion of nickel in metallic form (XRD, TPR–H₂), with a particle size from 2 to 10 nm (TEM). The composites were shown to have a SSA of up to 269 m²/g. The resulting composite materials were used as catalysts for the decomposition of methane to produce hydrogen. High activity was observed in the catalytic methane decomposition at 700 °C (methane conversion up to 25.8%; hydrogen yield up to 1.98 g_H2/g_Ni/h). Full article

Heavy metal exposure is increasingly linked to impaired childhood growth, but the biological mechanisms are poorly understood. Here, we assessed associations between heavy metal exposure and growth impairment (idiopathic short stature [ISS] and growth hormone deficiency [GHD]) in 36 children (24 cases, 12 controls, males 41.7%), identifying related alterations in circulating exosomal miRNAs. Blood/urine concentrations of nine metals, including Pb, As, and Hg were measured, and serum exosomal miRNAs were profiled via sequencing. Elevated heavy metal exposure was associated with significantly increased proportions of ISS and GHD. Specifically, high blood Pb was associated with ISS (p = 0.01) and high urinary As with overall short stature (p = 0.03). Elevated urinary Hg showed a marginal association with GHD (p = 0.07). Differentially expressed miRNAs were identified: hsa-miR-4488 was downregulated in high-Pb and ISS groups, whereas hsa-miR-133a-3p and hsa-miR-4516 were upregulated in high urinary Hg/As and GHD groups. Predicted targets of these miRNAs involved growth hormone (GH)–insulin-like growth factor-1 (IGF-1) signaling and endochondral ossification. In conclusion, Pb, As, and Hg exposures were associated with impaired growth in children. The dysregulation of related miRNAs suggests biological mechanisms involving both local growth-plate dysfunction and GH-IGF1 signaling disruption. Full article

Sexual size dimorphism (SSD) refers to the phenomenon where males and females of the same species exhibit differences in overall or partial body size, and it is widespread among mammals, birds, reptiles, and fish. Notably, this dimorphism is significantly influenced by the sexually dimorphic secretion of growth hormone (gh), a key pituitary-derived growth regulator. Commonly, the secretion of gh is positively regulated by glucagon family members such as growth hormone-releasing hormone (ghrh) and adenylate cyclase-activating polypeptide 1 (adcyap1). To explore the stimulators for pituitary hormones (especially gh) in the teleost, we performed genome-wide identification and functional characterization of the glucagon family on Chinese tongue sole (Cynoglossus semilaevis) that exhibits typical female-biased sexual size dimorphism. Four members of adcyap1/vasoactive intestinal polypeptide(vip)/ghrh family and ten members of their receptor family were identified. Expression pattern analysis revealed high expression of adenylate cyclase-activating polypeptide 1b (adcyap1b) and its receptors in the brain. Moreover, two alternative splice variants for the adcyap1b gene were discovered, resulting from the skipping of exon 4. Following the acquisition of the two eukaryotic recombinant protein splice variants (ADCYAP1b_tv1 and ADCYAP_tv2) from HEK 293T cells, incubation experiments were conducted using C. semilaevis pituitary cell line. The results demonstrated that both variants promoted the expression of gh, pro-opiomelanocortin (pomc), and corticoliberin (crh), but ADCYAP1b_tv1 had a significantly stronger effect and uniquely stimulated prolactin (prl) and somatolactin (sl). This study demonstrates a functional divergence between the two ADCYAP1b splice variants in teleosts, with ADCYAP1b_tv1 acting as a more potent and versatile pituitary hormone stimulator. Further research on their receptor-binding affinity and downstream signaling pathways would be valuable for exploring the mechanism underlying sexual size dimorphism. Full article

Introduction: Gestational hypoxia (GH) increases the risk of cardiovascular diseases by inducing oxidative stress and vascular dysfunction. This study investigates whether prenatal melatonin can mitigate these effects in guinea pigs. Methods: Pregnant guinea pigs were exposed to normoxia or hypoxia and treated with melatonin (1 mg/kg/day). Echocardiography, vascular reactivity, and molecular assays were used to assess cardiovascular structure, function, and redox balance in neonates. Results: GH reduced neonatal birth weight and altered left ventricular (LV) development, resulting in increased LV systolic function and aortic blood flow velocity. Melatonin treatment reversed these effects, restoring endothelial-dependent vasodilation and decreasing oxidative stress in the LV and thoracic aorta. Catalase antioxidant enzyme activity was elevated in melatonin-treated hypoxic neonates. Unexpectedly, melatonin treatment altered cardiac structure in normoxic pregnancies, increasing LV length and decreasing LV myocardial nuclei density. Conclusions: Prenatal melatonin partially modulates GH-induced endothelial dysfunction and oxidative stress, offering potential therapeutic value. However, its effects under normoxic conditions deserve caution, emphasizing the need for targeted use only in pregnancies with evident hypoxic and oxidative stress conditions. Full article

This study systematically investigates the microstructural evolution and mechanical properties of GH2787 superalloy following solution treatment at 1140 °C and subsequent aging within the temperature range of 770 °C to 920 °C. The results indicate that aging at 770 °C and 820 °C promotes the precipitation of a high density of finely dispersed γ′ precipitates with minimal interparticle spacing. In contrast, a significant coarsening of the γ′ particles, accompanied by a sparse distribution and a notable increase in interparticle spacing, was observed at the higher aging temperatures of 870 °C and 920 °C. Mechanical characterization reveals that the ultimate tensile strength (UTS) and yield strength (YS) experienced a moderate decrease as the aging temperature increased from 770 °C to 820 °C, followed by a pronounced drop at 870 °C and 920 °C. Conversely, the impact toughness exhibited a non-monotonic trend: it gradually decreased, reaching a minimum at 820 °C, before rapidly increasing with further rises in aging temperature. Quantitative analysis of the strengthening contributions demonstrates that solid-solution and precipitation strengthening are the dominant mechanisms. The marked decline in yield strength at elevated aging temperatures is primarily attributed to the diminished precipitation strengthening effect due to γ′ coarsening. Furthermore, the variation in impact toughness can be linked to the proportion and size of dimples observed on the fracture surfaces, indicating a transition in the fracture mechanism driven by microstructural evolution. Full article

Background/Objectives: Perineoplasty can be performed as an adjunct to native tissue pelvic organ prolapse (POP) surgery; the optimal indication for perineoplasty is unknown due to limited evidence regarding its benefits and the absence of clear clinical guidelines. This study aims to describe patient-related factors associated with surgeons’ decisions to add perineoplasty to POP surgery and to quantify the frequency of intraoperative changes from preoperative surgical plans. Methods: In this multicenter observational cohort study, women ≥ 18 years scheduled for primary native tissue POP surgery between April 2023 and November 2024 were included. Baseline characteristics, pelvic floor anatomy (POP-Q), genital hiatus (GH), perineal body (PB) measurements, and surgeon-reported considerations regarding perineoplasty were collected. Surgical plans (“with”, “without”, or “undecided”) were documented and compared with the actual performed procedure. Logistic and linear regression analyses were used to identify factors associated with perineoplasty. Results: Among the 305 enrolled women, 285 underwent surgery, of whom 135 (47%) received perineoplasty. Patients who underwent perineoplasty had a larger GH size (5.2 cm) compared to patients without perineoplasty (4.5 cm). Obesity was associated with an increased rate of perineoplasty compared to normal weight (OR 2.3 95%CI 1.2–4.6). There was a strong exponential association between childbirth and perineoplasty, with a fivefold increase for two children (95%CI 1.3–17.1) and thirtyfold increase for four or more children (95%CI 6.3–142) compared to one child. Nearly all procedures (92%) followed the preoperative plan; surgeons were more likely to omit than add perineoplasty intraoperatively. Surgeons frequently reported GH/PB size and age as key considerations to perform perineoplasty and lack of evidence and fear of dyspareunia as reasons to not perform perineoplasty. Conclusions: Surgeons more often perform perineoplasty in patients with factors that have been associated with a higher risk of recurrent prolapse. Prospective comparative studies are required to determine whether perineoplasty reduces recurrent POP after primary surgical repair. Full article

Acromegaly is a rare endocrine disease characterized by multiple metabolic abnormalities and high cardiovascular risk. This cross-sectional study evaluated the lipidomic serum profile of 109 participants (59 acromegaly patients versus 50 healthy controls) via high-performance liquid chromatography combined with mass spectrometry (HPLC-MS). The lipidomic profile that differentiated acromegaly from controls included sphingomyelins (SMs), glycerophospholipids, glycerolipids, ceramides, fatty acids, wax esters (WEs), carnitines, and sterol (ST) lipids. SM 34:0;O2 and phosphorylcholine best distinguished acromegaly patients from controls (VIP > 2.49). SM 34:0;O2 levels were significantly elevated in treatment-naïve versus uncontrolled patients (p < 0.0001). Furthermore, SM 34:0;O2 positively correlated with random GH and IGF-1. Lack of therapy predicted SM 34:0;O2 serum titers in acromegaly. Profound alterations of glycerophospholipids and sphingolipids were detected in acromegaly patients with cardiovascular complications. ST 24:1;O3, ceramide (Cer) 38:0;O4, and WE 34:1 were significantly increased in both hypertensive acromegaly patients and those with heart failure in comparison to patients without cardiovascular impairment. In conclusion, SM 34:0;O2 and phosphorylcholine emerged as potential lipidomic biomarkers in acromegaly. Moreover, SM 34:0;O2 potentially reflects disease severity. Identifying lipidomic profile alterations in acromegaly patients with cardiac involvement may provide a basis for further insights into the cardiovascular pathogenesis of the disease. Full article

Background and Objectives: The effect of growth hormone (GH) on body composition is well recognized, and recombinant human GH (rGH) therapy may improve lean mass and related parameters. The aim of this study was to analyze changes in body composition parameters and lipid profile under rGH treatment in children diagnosed with short stature and to explore potential influencing factors. Materials and Methods: A secondary data analysis was conducted in the Endocrinology Department of the Mures County Hospital, Romania, approved by the local Ethics Committee. All children diagnosed with short stature and receiving rGH treatment were eligible for inclusion if they had four body composition analyses at least 6 months apart. Analyzed variables included age, gender, environment, mean rGH dose, height and body mass index (BMI) SDS, body composition parameters assessed by bioimpedance, and family-related variables. Statistical analysis was performed using SPSS v.25 with a level of significance α = 0.05. Results: There was no statistically significant trend in body composition parameters taken during serial measurements, except for the sarcopenic index and height (p < 0.001). Environment, pubertal development, and family-related variables other than maternal BMI had no significant influence on body composition or lipid profile. Gender differences in body composition revealed that the change in muscle mass (p = 0.009) and skeletal muscle mass (p = 0.013) was statistically significantly higher for boys, and body fat (p = 0.013) for girls. In linear regression analysis, mother’s BMI emerged as a significant predictor for changes in high-density lipoprotein cholesterol (HDL-C) levels (p = 0.032, β = −0.691) during rGH therapy. Body composition changes did not differ by treatment indication. Conclusions: Gender may be associated with treatment-related changes in body composition during pediatric rGH therapy, while maternal BMI may predict HDL-C variation. rGH treatment appears to improve the sarcopenic index and has minimal and variable effects on the lipid profile. Full article

Chitinases are crucial in the molting process of insects and represent potential targets for the development of RNA interference (RNAi)-based insecticidal strategies. In this study, we identified and characterized 11 chitinase genes (TaChts) in T. absoluta, each harboring at least one GH18 catalytic domain. Phylogenetic analysis placed these proteins into 11 established groups (I-X and h), revealing conserved lineage-specific patterns. Spatiotemporal expression profiling showed that most TaChts peak during key developmental transitions. TaCht1, TaCht2, TaCht3, TaCht5, TaCht6, TaCht7, TaCht10, TaCht-h, and TaIDGF were predominantly expressed in the integument, whereas TaCht8 and TaCht11 showed gut-enriched expression, indicating functional specialization. Stage-tailored RNAi assays demonstrated that silencing TaCht5, TaCht7, TaCht10, and TaIDGF caused pronounced mortality in both larvae and pupae. In larvae, delivery of dsRNA using carbon quantum dots (CQDs) disrupted molting: knockdown of TaCht7, TaCht10, and TaIDGF prevented shedding of the old cuticle, whereas TaCht5 silencing produced severe cuticular shrinkage and blackening. Hematoxylin and eosin staining revealed detachment of epidermal cells from the cuticle, providing cytological evidence of disrupted cuticle–epidermis remodeling. In pupae, microinjection of dsRNA induced cuticular collapse, melanization, and eclosion failure due to persistent adhesion of the pupal case, accompanied by marked reductions in chitinase activity. Together, our findings highlight the critical roles of four key chitinases in endocuticular turnover and metamorphic progression in T. absoluta, offering mechanistic insight into chitin-mediated developmental processes. The identified genes represent strong candidates for RNAi-based, species-specific pest management strategies against this globally significant insect. Full article

Micronutrients, particularly boron (B), iron (Fe), manganese (Mn), and zinc (Zn), are pivotal for cotton (Gossypium spp.) growth, reproductive success, and fiber quality. However, their critical roles are often overlooked in fertility programs focused primarily on macronutrients. This review synthesizes recent advances in the physiological, molecular, and agronomic understanding of B, Fe, Mn, and Zn in cotton production. The overarching goal is to elucidate their impact on cotton nutrient use efficiency (NUE). Drawing from the peer-reviewed literature, we highlight how these micronutrients regulate essential processes, including photosynthesis, cell wall integrity, hormone signaling, and stress remediation. These processes directly influence root development, boll retention, and fiber quality. As a result, deficiencies in these micronutrients contribute to significant yield gaps even when macronutrients are sufficiently supplied. Key genes, including Boron Transporter 1 (BOR1), Iron-Regulated Transporter 1 (IRT1), Natural Resistance-Associated Macrophage Protein 1 (NRAMP1), Zinc-Regulated Transporter/Iron-Regulated Transporter-like Protein (ZIP), and Gossypium hirsutum Zinc/Iron-regulated transporter-like Protein 3 (GhZIP3), are crucial for mediating micronutrient uptake and homeostasis. These genes can be leveraged in breeding for high-yielding, nutrient-efficient cotton varieties. In addition to molecular hacks, advanced phenotyping technologies, such as unmanned aerial vehicles (UAVs) and single-cell RNA sequencing (scRNA-seq; a technology that measures gene expression at single-cell level, enabling the high-resolution analysis of cellular diversity and the identification of rare cell types), provide novel avenues for identifying nutrient-efficient genotypes and elucidating regulatory networks. Future research directions should include leveraging microRNAs, CRISPR-based gene editing, and precision nutrient management to enhance the use efficiency of B, Fe, Mn, and Zn. These approaches are essential for addressing environmental challenges and closing persistent yield gaps within sustainable cotton production systems. Full article

The increasing accumulation of plastic debris in aquatic environments has raised concerns about the ecotoxicological effects of polystyrene nanoplastics (PSNPs). This study examined PSNPs toxicity during a critical developmental stage by exposing 15 days post-fertilization (dpf) larvae of blotched snakehead (Channa maculata), an economically important freshwater fish, to PSNPs concentrations of 0.05–20 mg/L for 15 days. Histopathological analysis showed concentration-dependent damage, including hepatocellular vacuolization (5–10 mg/L) and hepatic sinusoidal dilation (20 mg/L) in the liver, alongside intestinal injuries ranging from villus erosion to rupture (5–20 mg/L). Biochemically, PSNPs triggered a biphasic oxidative response, where superoxide dismutase (SOD) and catalase (CAT) activities peaked at 5 mg/L before declining, while malondialdehyde (MDA) levels exhibited an opposite trend. Transcriptomic analysis and Quantitative real-time PCR (qRT-PCR) indicated that PSNPs disrupted growth, energy metabolism, and immune regulation in C. maculata larvae, evidenced by the dysregulation of growth hormone/insulin-like growth factor (GH/IGF) axis genes and up-regulation of immune-related genes. Furthermore, Weighted Gene Co-expression Network Analysis (WGCNA) identified the heterogeneous nuclear ribonucleoproteins (HNRNP) gene family as hub genes from the key turquoise module, suggesting that PSNPs interfere with RNA processing and post-transcriptional control. In summary, PSNPs caused multi-level toxicity in C. maculata larvae, providing new insights into their ecotoxicological hazards in freshwater ecosystems. Full article