Search Results (11,014)

Effective ablative thermal protection systems are essential for ensuring the structural integrity of hypersonic vehicles subjected to extreme aerothermal loads. However, the microscopic reaction mechanisms at the gas–solid interface, particularly under non-equilibrium high-enthalpy conditions, remain poorly understood. This study employs reactive molecular dynamics (RMD) simulations with the ReaxFF-C/H/O force field to investigate the atomic-scale ablation behavior of a graphene-based knitted graphene structure impacted by atomic oxygen (AO). By systematically varying the AO incident kinetic energy (from 0.1 to 8.0 eV) and incidence angle (from 15° to 90°), we reveal the competing interplay between catalytic recombination and ablation processes. The results show that the catalytic recombination coefficient of oxygen molecules reaches a maximum at 5.0 eV, where surface-mediated O₂ formation is most favorable. At higher energies, the reaction pathway shifts toward enhanced CO and CO₂ production due to increased carbon atom ejection and surface degradation. Furthermore, as the AO incidence angle increases, the recombination efficiency decreases linearly, while C-C bond breakage intensifies due to stronger vertical energy components. These findings offer new insights into the anisotropic surface response of knitted graphene structures under hyperthermal oxygen exposure and provide valuable guidance for the design and optimization of next-generation thermal protection materials for hypersonic flight. Full article

Adipose tissue functions not only as a lipid storage depot but also as an active endocrine organ that regulates key physiological processes. In obesity, oxidative stress disrupts the molecular pathways for adipose tissue homeostasis, triggering chronic inflammation, tissue dysfunction, and metabolic disorders. This review explores the mechanisms by which lipid storage drives adipose tissue expansion, highlighting the detrimental effects of hypertrophy in promoting oxidative stress, inflammation, and insulin resistance. These processes can ultimately contribute to metabolic pathologies such as cardiovascular diseases and type 2 diabetes. We also discuss how lipid composition influences these pathways, acting as signaling molecules that activate inflammatory and oxidative stress-related signaling cascades. Additionally, we compile evidence from studies on individuals with obesity, identifying lipids, oxidative stress markers, and inflammatory mediators as potential biomarkers of metabolic dysfunction. Finally, we assess the therapeutic potential of antioxidants in mitigating the metabolic effects of obesity, focusing on their mechanisms of actions. By integrating these insights, this review aims to clarify the complex relationship between oxidative stress, lipid metabolism, and inflammation, and highlight the role of antioxidant molecules in addressing adipose tissue dysfunction in obesity. Full article

Although conventional medicine has seen substantial progress in recent years, there is a growing interest in nutraceuticals, bioactive compounds derived from natural sources such as plants, fruits, and cereals, due to their potential therapeutic applications. These substances have garnered increasing attention for their capacity to support ocular health and to aid in the prevention and management of age-related eye disorders, including age-related macular degeneration (AMD), cataracts, and glaucoma. This review provides a comprehensive and detailed analysis of selected nutraceuticals related to ocular health and diseases. It aims to define their pharmacodynamic properties, to elucidate the molecular and cellular mechanisms underlying their effects and to critically evaluate the current evidence regarding their potential clinical applications. By integrating findings from both preclinical and clinical studies, this review seeks to offer insights into the role of these nutraceuticals in the prevention, management, and adjunctive treatment of various ocular disorders, thereby suggesting future research directions and clinical practice. Notable attention is given to their antioxidant, anti-inflammatory, and neuroprotective properties, which are believed to contribute to the preservation of visual function and the deceleration of disease progression. Elucidating the medicinal benefits of these compounds may open new pathways for complementary or alternative strategies in the prevention and treatment of ocular diseases. Full article

Salinity is a major limiting factor for all food crops, mainly Chinese cabbage. This study aimed to investigate the effects of biochar (BC) on physiological, biochemical, and molecular responses of Chinese cabbage grown under salinity stress in an open field. We supplied three concentrations of BC (5, 10, and 15 t/ha) to the 200 mM NaCl salinity-stress-induced field, which enhanced physical and chemical properties of the soil. Under salinity stress, BC increased photosynthetic pigments and reduced proline and H₂O₂ contents. Notably, 5 t/ha BC boosted plant growth, biomass, and yield by >40% and inhibited ROS accumulation under salinity stress. BC also promoted the concentrations of various key micronutrients, particularly Fe and Zn, in Chinese cabbage under salinity stress, which may contribute to improving the nutrient content. BC under salinity stress significantly induced the expression of NHX family genes (BoNHX1 and BoNHX2). Among these, the BoNHX1 gene was found to be highly expressed in shoot and root tissues of Chinese cabbage grown under salinity stress with BC. Identification of this key candidate gene will lay the groundwork for further functional characterization studies to elucidate its role under salinity stress with BC. This study comprehensively analyzes the physiological, biochemical, and molecular impacts of BC application in Chinese cabbage under salinity stress. This study found that the application of 5 t/ha significantly improved various physiological and biochemical traits of Chinese cabbage under salinity stress compared to the other treatments. The outcome of this study provides novel insights into the bioprotective role of BC, offering a valuable foundation of organic supplements for farmers while also highlighting potential research directions for enhancing crop resilience and productivity in economically important crops. Full article

The symbiotic microbiome constitutes a consortium that has been persistently domesticated by a specific algal species, fostering a close and enduring association with the host. The majority of microbial taxa remain uncharacterized. These unknown microbes, often referred to as “microbial dark matter (MDM)”, have important ecological contributions. Given the challenges in discerning symbiotic microbes in natural environments, herein, ecological characteristics of MDM and known taxa within symbiotic communities were investigated in a simulated bloom process using Alexandrium pacificum without antibiotic treatment. Specifically, increased diversification was observed in MDM along the bloom process. Higher trophic interaction and less vulnerability of the molecular network were found in MDM taxa. The “bridge” role of MDM species was better than that of known taxa, as shown by higher betweenness centralization. Deterministic processes dominated in MDM taxa, which promote phylogenic diversity of such groups to some extent. The findings highlight that MDM taxa play an important role in sustaining community stability and functioning. This study broadens our understanding of the ecological contribution of MDM under disturbances from dinoflagellate blooms, providing essential theoretical insights and empirical data to inform the management of coastal toxic blooms. Full article

The increasing challenge posed by climate change necessitates a deeper understanding of the plant metabolic pathways that influence productivity under varying environmental conditions. In this context, investigating the impact of L-phenylalanine ammonia-lyase (PAL) inhibition on flag leaf physiology in winter triticale provides valuable insights into mechanisms that may affect crop productivity. This study investigated the physiological and molecular responses of the flag leaf following the application of 4-hydroxybenzoic acid hydrazide (HBH), a PAL inhibitor. It was hypothesized that PAL inhibition would redirect carbon flow towards carbohydrate synthesis at the expense of phenolic production, accompanied by alterations in photosynthetic performance and antioxidant responses. HBH was detected in flag leaf tissues and caused a significant reduction in phenolic content, along with a marked increase in soluble carbohydrate levels. HBH treatment strongly activated the antioxidant system, as evidenced by elevated levels of non-enzymatic antioxidants and the increased activity of antioxidant enzymes. Changes were also observed in chlorophyll fluorescence parameters and in the accumulation of proteins associated with CO₂ fixation and the photosynthetic apparatus function. These findings demonstrate that PAL inhibition can substantially affect the redox balance and photosynthetic activity of the flag leaf during a critical period of plant development and yield formation. Full article

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental condition marked by persistent inattention, hyperactivity, and impulsivity. Despite its considerable global prevalence, key gaps remain in our understanding of the structural and molecular changes underlying ADHD which complicate adult diagnosis, as symptoms present differently from those observed during childhood ADHD. On the other hand, while psychostimulants effectively mitigate some symptoms, significant controversy surrounds their long-term effects on cognition, learning, and memory, and day-to-day living. Moreover, our understanding of how various medications given to alleviate ADHD symptoms during pregnancy impact the developing fetal brain also remains largely unexplored. Here, we discuss the subtle differences between ADHD in children and adults and how these symptoms alter brain development and maturation. We further examine changes in monoamine signaling in ADHD and how psychostimulant and non-pharmacological treatments modulate these neural networks. We evaluate and discuss findings as they pertain to the long-term use of ADHD medications, including in utero exposure, on cognitive outcomes, and contextualize these findings with mechanistic insights from animal models. Full article

We theoretically investigate high-order harmonic generation from ethylbenzene (C₈H₁₀), toluene (C₇H₈), and benzene (C₆H₆) molecules driven by a circularly polarized laser field using time-dependent density functional theory. By comparing the harmonic spectra of these structurally related molecules, we find that ethylbenzene, which features a larger molecular size due to the ethyl group, exhibits a higher harmonic cutoff and stronger harmonic intensity than toluene and benzene. Time-resolved electron density distributions, together with the probability current density analysis, indicate that under long-wavelength conditions (e.g., 1200 nm), the ethyl group in ethylbenzene and the methyl group in toluene significantly enhance the probability of ionized electrons from neighboring nuclei colliding with nearby nuclei, thereby leading to stronger harmonic emission, with ethylbenzene > toluene > benzene. In contrast, under short-wavelength conditions (e.g., 200 nm), the harmonic intensities of the three molecules show little difference, and the effects of the ethyl and methyl groups on the harmonic yield can be neglected. The influence of laser intensity and wavelength on high-order harmonic generation is further analyzed, confirming the robustness of the structural enhancement effect. Additionally, we study the harmonic ellipticity of ethylbenzene under different carrier-envelope phases, and find that while circularly polarized harmonics can be obtained, their spectral continuity is insufficient for synthesizing isolated circularly polarized attosecond pulses. This limitation is attributed to the broken ring symmetry caused by the ethyl substitution. Our findings offer insight into the relationship between molecular structure and harmonic response in strong-field physics, and provide a pathway for designing efficient circularly polarized attosecond pulse sources. Full article

Sex determination is a fundamental biological process governing animal reproduction. Although substantial progress has been made in elucidating its genetic basis, the genetic architecture underlying complex sex determination systems remains poorly understood. In this study, we identify sex-associated insertion–deletion (indel) variants, screen candidate genes, and compare sex-associated variation across populations with different genetic backgrounds in the Fujian oyster (Magallana angulata). Based on whole-genome resequencing data of a culture strain (designated FL), a total of 299,774 high-quality indels were identified. By integrating genome-wide association analysis (GWAS), fixation index (F_ST) analysis, and sex-biased genotype frequency comparisons, 77 overlapping sex-associated indels were identified, predominantly clustered within a 1.8 Mb (8.3–10.1 Mb) region on chromosome 9. Principal component analysis (PCA) based on the sex-associated markers and their subsets consistently separated male and female individuals in the FL strain. For two representative sex-associated indels, PCR-based genotyping methods were developed and validated. Functional annotation identified putative candidate genes for sex determination, including PKD1L1, 5-HTRL, SCP, and CCKRa. Comparative analysis of variants within PKD1L1 across wild, farmed, and selectively bred populations revealed a progressive enrichment of male-linked alleles in domesticated and selectively bred groups, particularly in male individuals. This study provides direct evidence that sex in the Fujian oyster is genetically determined and reveals that domestication and artificial selection may drive the emergence of major sex-determining loci, offering important insights into the genetic basis of sex determination in the Fujian oyster, and establishing a theoretical and practical foundation for molecular marker-assisted breeding of monosex lines for this species. Full article

Background: Theophylline, which is biologically important and found in tea, coffee, and cocoa beans, can be synthesized chemically or by direct extraction and concentration from natural sources. Theophylline derivatives have garnered attention in recent years for their potential therapeutic effects on Mycobacterium tuberculosis, antihistaminic, anti-inflammatory, and anticancer. Also, trifluoromethyl (CF₃) group has also been widely used in drug and agrochemical design. Methods: In this study, a series of new theophylline derivatives containing substituted trifluoromethyl and trifluoromethoxy groups were synthesized. The structures of these new compounds were confirmed by NMR, FT-IR, and elemental analyses. Additionally, the anticancer activities of the molecules were analyzed against VEGFR-2, CYP P450, and estrogen receptor by molecular docking method. Furthermore, in vitro biological effects of the compounds were comprehensively evaluated in cancer (A549 and HeLa) and normal (BEAS-2B) cells. Cell viability was assessed by MTT assay, and selectivity index (SI) values were calculated to determine tumor-specific toxicity. Results: N(7)-substituted theophyllines were prepared by the reaction of 1,3-dimethyl-3,7-dihydro-1H-purine-2,6-dione (theophylline) and trifluoromethyl substituted benzyl halide compounds. The synthesized N(7)-substituted theophyllines were obtained as white powder in high yield. The structure of synthesized compounds was confirmed by various spectroscopic techniques such as ¹H, ¹³C, ¹⁹F NMR, and FT-IR spectroscopy, and elemental analysis. The highest interaction was recorded as −5.69 kcal/mol for 3-CF₃ substituted against VEGFR-2 structure while the best binding affinity was determined for 4-OCF₃ substituted with −6.69 kcal/mol against Human Cytochrome P450 with in silico analysis. The in vitro anticancer activities of the molecules were also evaluated against A549 and HeLa cells, and displayed considerably higher cytotoxicity with 2-CF₃, 3-CF_3, and 4-CF₃ substituted molecules in Hela and A549 cell line. To elucidate the molecular mechanism, apoptosis-related gene expression changes were analyzed by RT-qPCR in A549 and HeLa cells treated with compound 2-CF₃. Significant upregulation of pro-apoptotic markers and downregulation of anti-apoptotic genes were observed. Consistently, ELISA-based quantification confirmed increased protein levels of Caspase-3, BAX, and Cytochrome C, and decreased BCL-2, validating the apoptotic mechanism at the protein level. Also, the antibacterial and antibiofilm activity details of the molecules were evaluated against DNA Gyrase, and SarA crystal structures by molecular docking method. The highest interaction was recorded as −5.56 kcal/mol for 2-CF₃ substituted with H-bonds with Asn46, Val71, Asp73, and Thr165 against DNA Gyrase crystal structure while 3-CF₃ substituted has the best binding affinity against SarA. The in vitro antimicrobial effects of the molecules were also evaluated. Conclusions: The synthesized molecules may provide insight into the development of potential therapeutic agents to the increasing antimicrobial resistance and biofilm-forming capacity of microorganisms. Additionally, compound 2-CF₃ substituted exhibited promising and selective anticancer activity through apoptosis induction, supported by gene and protein level evidence. Full article

Childhood obesity has emerged as one of the most pressing public health challenges of the 21st century. Early-onset obesity is associated with an increased risk of developing numerous comorbidities later in life. Despite extensive research into its multifactorial etiology—including genetic, behavioral, environmental, and socioeconomic factors—the precise molecular mechanisms underlying the development and persistence of obesity in the pediatric population remain incompletely understood. Proteomics offers promising insights into these mechanisms. The application of proteomics in pediatric obesity research has grown, enabling the identification of proteins that reflect dynamic changes in metabolic and inflammatory pathways. This advancement allows clinicians to move beyond traditional anthropometric measurements toward personalized approaches with notification of early complications of obesity. A systematic search was conducted across PubMed, Scopus, and Web of Science for studies published between 2010 and 2025. Inclusion criteria: human studies, participants aged 0–18, proteomic analysis of obesity, and biomarkers. Data extraction and quality assessment followed standardized protocols. From 239 articles, 20 were included. Key dysregulated proteins include APOA1, CLU, and HP. LC-MS/MS was the predominant technique used. Some biomarkers were predictive for obesity complications in children. Proteomics holds clinical potential for early detection and personalized treatment of pediatric obesity. Standardized methodologies and longitudinal studies are needed for translation into clinical practice. Full article

Avian poxvirus was diagnosed in eight wild Stone-curlews (Burhinus oedicnemus) from the Canary Islands, based on a combination of pathological and molecular analysis. Affected birds exhibited lesions consistent with poxvirus infection; three of four with mild lesions (≤2 on pelvic limbs, excluding phalanges) were successfully rehabilitated and released, while four with moderate (≤2 on phalanges) to severe lesions (≥3 on phalanges) potentially faced impaired mobility, increased predation risk, and reduced foraging efficiency. Histopathology of six individuals revealed Bollinger bodies, characteristic of Avipoxvirus infection, and molecular analysis confirmed the presence of viral DNA in six cases. Three genetically distinct viral variants were identified, each associated with different phylogenetic clades and subclades, suggesting substantial viral diversity within this host species. Co-infection with Aspergillus fumigatus was also detected in six of the eight birds, confirmed by molecular analysis in either skin lesions or lung tissue. To our knowledge, this represents the first report of A. fumigatus co-infection in Stone-curlews with Avipoxvirus. Additionally, one individual presented a tumor-like lesion, expanding the known pathological manifestations of the disease. These findings provide new insights into avian pox and highlight the importance of considering fungal co-infections in the differential diagnosis, given their potential to exacerbate disease severity. Full article

Monkeypox (Mpox), a re-emerging zoonotic disease, has garnered global attention due to its evolving epidemiology, diverse clinical manifestations, and significant public health impact. The rapid international spread of the Mpox prompted the World Health Organization to designate the outbreak as a Public Health Emergency of International Concern. Accurate and timely diagnosis is hindered by its critical resemblance to other orthopoxviruses and viral exanthems, underscoring the need for improved diagnostic tools. Point-of-care diagnostic innovations, including CRISPR-based and smartphone-integrated technologies, have revolutionized outbreak management, offering rapid and accurate detection critical for containment and treatment. The effective control of Mpox outbreak underscores the necessity of strengthened global surveillance, equitable healthcare access, rapid diagnostics, the prompt isolation of infected individuals, and the implantation of ring vaccination strategies. The integration of a “One Health” framework that links human, animal, and environmental health is vital for sustained preparedness. Advances in vaccine development, including novel bionic self-adjuvating vaccines and platforms utilizing DNA, mRNA, and viral vectors, highlight promising prevention efforts. However, issues such as vaccine hesitancy, limited immunization coverage and accessibility in resource-constrained regions remain significant barriers. Therapeutic interventions like tecovirimat and the JYNNEOS vaccine demonstrate efficacy but face challenges in scalability and deployment. To address these multifaceted challenges, this review delves into the molecular insights, clinical features, epidemiological trends, and diagnostic challenges posed by Mpox. This review further highlights the critical need for robust scientific evidence and sustained research to inform effective, evidence-based responses, and long-term management strategies for Mpox outbreaks. Full article

Plants are capable of responding to various environmental stresses by initiating the expression of genes that encode proteins involved in plant growth, fruit ripening, maintaining protein homeostasis, and combating heat stress (HS) by activating heat tolerance systems. The mechanism of resisting against HS is very intricate, and the molecular basis and involvement of the related gene network in Capsicum annuum L. are not fully understood. There are five different heat shock proteins (HSPs) reported in the literature, namely, small HSPs (sHSPs), CaHSP60s, CaHSP70s, CaHSP90s, and CaHSP100s, which play a pivotal role in heat stress response (HSR) in C. annuum. Heat shock factors (HSFs) and heat stress elements (HSEs) govern the transcriptional modifications and control the relative expression of heat shock proteins (HSPs). The heat stress response is the reprogramming of the molecular cascades involving the cell stress responses against the HSR, which is characterized by the increased production of molecular chaperones, which help the plants to counter the negative physiological impacts on proteins, induced by heat and other abiotic stresses. Therefore, understanding the detailed molecular mechanisms of C. annuum in response to extreme temperatures is critical for exploring how they will be affected by climate change and how they behave to cope with these varied climate extremes. This study is focused on providing a complete understanding of the molecular cascades in C. annuum L.’s response to HS, which starts with the sensation of HS signals and activation of the relative molecular cascades that are responsible for the activation of HSFs and initiate their primary targets, e.g., HSPs. Overall, this review provides deep insights into all the cellular responses during HS with a special focus on categorization and physiological aspects of HSPs and HSFs. Full article

Water temperature stands as a crucial environmental element, exerting an impact on the survival and growth of organisms in aquaculture. Heat stress poses a significant threat to the survival and aquaculture of the Hong Kong oyster Magallana hongkongensis (also known as Crassostrea hongkongensis), yet the underlying physiological and molecular mechanisms remain poorly understood. This study investigated the effects of elevated temperatures (35 °C and 37 °C) on survival, DNA damage, antioxidant enzyme activities, and gene expression related to apoptosis, inflammation, and heat shock proteins (HSPs) in M. hongkongensis. The median lethal temperature (LT50) of M. hongkongensis was determined to be 37.09 °C, with significant mortality observed at 35 °C compared with the control (29 °C). Antioxidant enzyme activities (SOD, CAT, and GPx) and T-AOC were up-regulated initially but exhibited divergent patterns under prolonged stress, indicating a temperature-dependent threshold for oxidative defense. Comet assay results also showed that heat stress induced severe DNA damage in hemocytes. Moreover, heat stress significantly up-regulated mRNA expression of apoptosis-related genes (Caspase-2, Caspase-8, Bax, and P53), inflammatory genes (TNF, p38-MAPK, and AP-1), and HSP family members (Hsp70, Hsp90, Hsp27, and Hsp68). The expression peaks of these genes were generally earlier and more pronounced at 37 °C, reflecting intensified cellular damage and protective responses. Collectively, this study demonstrates that M. hongkongensis employs integrated antioxidant, apoptotic, inflammatory, and HSP-mediated mechanisms to counteract heat stress, but temperatures exceeding 35 °C disrupt these defenses, leading to survival impairment. These findings provide critical insights into the heat adaptation strategies of M. hongkongensis and serve as a scientific foundation for developing sustainable aquaculture practices to mitigate summer heat stress. Full article