Search Results (10,874)

A new approach to 5,5-fused heterocyclic derivatives of cyclopentadienylmanganese tricarbonyl and pentamethylruthenocene is presented. 1,2-Dicarbophenoxycyclopentadienyl complexes of manganese and ruthenium were hydrolyzed to 1,2-dicarboxylic acids. Oxalyl chloride converted the acids to chlorocarbonyls, which reacted with bis(trimethylsilyl)sulfide to give the cyclopentadienyl-fused thioanhydrides. Alternatively, dehydration of the diacids with trifluoroacetic anhydride closed the diacids to cyclopentadienyl-fused anhydrides. Treatment of the anhydrides with p-toluidine followed by oxalyl chloride led to cyclopentadienyl-fused carboxylic imides. This approach enables direct comparison of electron-deficient Mn(CO)₃ and electron-rich Ru(Cp*) coordination environments on the 5,5-fused heterocycles. Spectroscopic data reveal systematic downfield NMR shifts and higher infrared carbonyl stretching frequencies for the manganese complexes, consistent with lower electron density in the Mn(CO)₃ compared to Ru(Cp*). Crystallographic analyses confirm that heterocycle fusion occurs without significant perturbation of the metal–cyclopentadienyl geometry. Comparative analysis across the series demonstrates that metal-dependent effects are primarily electronic rather than structural, with the Mn(CO)₃ and Ru(Cp*) fragments modulating electron distribution within the fused ligand framework. Full article

Most airline passengers and crew assume that the air in the cabin is free from harmful or hazardous substances, as is mandated by airworthiness regulations. While fresh air entering the cabin is sterile (and if recirculated is usually efficiently filtered to remove microorganisms), if the fresh air is bled off the turbine compressors (as is the case in about 95% of airliners currently in service), it may be contaminated with traces of engine oil and ultrafine particles abraded from the turbine blades, and possibly traces of hydraulic fluid leaking from servo systems. Engine oil contains tricresyl phosphate (TCP) as an essential antiwear agent, but it is also a well-known neurotoxin, and it has been suggested that there may be no safe lower limit of exposure, not least because of considerable variation among individuals in sensitivity to tri-ortho-cresyl phosphate (ToCP) and other isomers with at least one ortho constituent. This paper reviews current knowledge about these hazards and discusses the medical and economic motivations for diminishing them. A calculation based on maintaining the life quality index shows that eliminating xenobiotic hazards in aircraft cabin air is likely to be affordable. Full article

Phosphorus (P) is a vital non-renewable macronutrient that is frequently immobilized by chemical fixation in acidic and calcareous soils. However, the specific transformation processes of different P sources across these different soil types remain poorly understood. A 120-day incubation experiment was conducted in a completely randomized design with three replicates using acidic and calcareous soils from Myanmar to evaluate six treatments: single superphosphate (SSP), diammonium phosphate (DAP), triple superphosphate (TSP), ammonium polyphosphate (APP), calcium phytate (CP), and an unfertilized control (CK). The modified Hedley fractionation method was employed to investigate the dynamic transformation of soil P fractions, the rate of available P transformation, and the relationship between soil transformation and soil P availability under different P-fertilizer sources. In both soils, SSP, DAP, and TSP provided high initial P release (249.7%, 239.9%, and 234.1%) in acidic soil and (159.5%, 170.8%, and 161.4%) calcareous soil, which peaked on day 10 compared to CK (p < 0.001) before rapidly declining. P transformation in calcareous soil declined more sharply than in acidic soil from the 10th day to the 15th day (especially in SSP and TSP, −11.3 and −16.9 mg kg⁻¹), indicating a higher rate of P immobilization in calcareous soil. Conversely, the delayed peak of APP (day 60) and the stability of CP indicate resistance to immediate soil fixation. Notably, overall effectiveness depended on soil type: SSP performed best in acidic soil and DAP in calcareous soil. Full article

Nutrient stoichiometry, particularly the balance of carbon (C), nitrogen (N), and phosphorus (P), plays a fundamental role in regulating freshwater ecosystem dynamics, primary production, and biogeochemical cycling. This study presents one of the first dedicated reviews to combine bibliometric mapping with ecological synthesis of C:N:P ratios in inland waters, drawing on 1004 publications indexed in the Web of Science Core Collection (2000–2025), comprising peer-reviewed articles and review articles refined by document type, language, and research area. Bibliometric mapping using VOSviewer (version 1.6.20) identified exponential growth in publications after 2010, with phosphorus dynamics and eutrophication emerging as the most-cited themes, while recent years have shown increasing attention to C:P ratios as reliable ecological indicators. Four dominant thematic clusters were identified: Nutrient Cycling and Biogeochemistry; Phytoplankton and Food Web Dynamics; Eutrophication and Water Quality; and Climate Change and Ecosystem Responses. Ecological synthesis demonstrated substantial deviations from the canonical Redfield ratio (106C:16N:1P), with pronounced stoichiometric variability across trophic states, latitudes, and ecosystem types. Case comparisons revealed high C:P ratios in Arctic and alpine lakes linked to dissolved organic carbon inputs, low N:P ratios in tropical waters that promote cyanobacterial dominance, and stable, low phosphorus concentrations in deep African lakes. These findings emphasize the significance of flexible stoichiometry in predicting ecosystem tipping points, managing harmful algal blooms (HABs), and guiding nutrient restoration strategies. By integrating bibliometric and ecological evidence, this study identifies C:P ratios as a promising candidate indicator that merits further field validation for freshwater management, while underscoring persistent research gaps in microbial stoichiometry, cross-scalar modeling, and policy uptake in the Global South. Full article

Background/Objectives: Severe brain injury (SBI) in very preterm infants includes heterogeneous lesions with distinct timing, burden and outcomes. We used cranial ultrasound (CUS) to describe SBI entity, documented timing, three-domain burden, deaths following documented withdrawal, withholding or non-escalation of life-sustaining treatment for poor neurological prognosis (neuro-WWLST), and survivor outcomes. Methods: Retrospective single-center cohort (1991–2020) of 2841 very preterm infants (<32 weeks’ gestation and/or birth weight ≤ 1500 g) with complete CUS within 48 h after birth. CUS was summarized by four windows, three domains—parenchymal lesion, intraventricular hemorrhage (IVH) and ventriculomegaly—and three mutually exclusive entities: periventricular hemorrhagic infarction (PVHI), cystic periventricular leukomalacia (cPVL and grade 3 IVH without PVHI/cPVL (IVH3 entity). Cross-outcome analyses used common maximal-burden CUS. Results: SBI occurred in 286/2841 infants (10.1%) and neuro-WWLST death in 45/2841 infants (1.6%); 43/45 occurred within SBI, and 43/89 SBI deaths (48.3%) followed documented neuro-WWLST. Using common maximal-burden CUS, severe three-domain involvement was more frequent among neuro-WWLST deaths than survivors (37.2% vs. 8.6%). Among SBI survivors with follow-up, cerebral palsy (CP) occurred in 87/176 (49.4%) and clinically classified school-age cognitive sequelae in 50/155 (32.3%). Outcomes varied by entity, with mainly ambulatory unilateral CP after PVHI, more frequent non-ambulatory bilateral CP after cPVL, and a heterogeneous IVH3 profile. Severe three-domain involvement identified a small subgroup with higher outcome burden, but outcomes were not deterministic. Conclusions: A structured, descriptive CUS approach separating lesion entity, documented timing and multidomain burden may support transparent cohort-level description of SBI trajectories, documented neuro-WWLST deaths and survivor outcomes. Full article

Osteoarthritis (OA) and osteoporosis (OP) are prevalent conditions with a complex relationship, yet their shared epigenetic mechanisms remain poorly understood. While genes like DKK1, RHOJ, and SOX6 have been implicated in both diseases, the specific role of individual CpG sites has not been fully characterized. We investigated CpG methylation in these genes using bisulfite pyrosequencing of peripheral blood DNA from n = 96 postmenopausal women: n = 24 with comorbid OA and OP, n = 34 with OA, and n = 38 healthy controls. Methylation differences were analyzed using statistical tests and logistic regression. Comorbid patients showed significant hypermethylation at two DKK1 CpG sites compared to the OA-only group (p_adj = 0.0007 and p_adj = 0.042). Conversely, one DKK1 site was hypomethylated in the OA-only group relative to controls (p_adj = 0.03). A regression model combining three DKK1 sites and one SOX6 site demonstrated predictive value for comorbid disease, with an AUC of 0.696. These findings identify site-specific methylation of DKK1 and SOX6 as a molecular signature associated with comorbid OA and OP, offering new insights into their shared etiology. Full article

The topito pepper (Capsicum chinense) is a tropical fruit of economic and gastronomic importance in the Caribbean region, valued for its nutritional content. However, this fruit is susceptible to postharvest fungal diseases, including those caused by the phytopathogenic fungus Penicillium expansum, which can degrade fruit quality and pose a health risk due to the potential presence of mycotoxins such as patulin. In this context, we evaluated the protective effects of coatings with chitosan (CS), clove essential oil (CEO), and their combination (CS+CEO) on sweet peppers stored at 12 °C for 12 days after harvest. The results indicate that the film-forming solution exhibited an acidic pH (5.33–5.44), a density of ~1.0 g/cm³, and viscosities ranging from 2.75 to 32.9 cP. Furthermore, the results indicate that coatings with CS and CS+CEO significantly reduced weight loss, preserved firmness (19.12–30.40 N), and delayed ripening. At the same time, the coatings exhibited inhibitory effects on P. expansum and aerobic mesophiles. The CS+CEO combination demonstrated the greatest inhibitory effect, indicating that it is a sustainable and effective strategy for the postharvest preservation of sweet peppers, thereby enhancing their value, preservation, and food security in the Caribbean region. Full article

Strigolactones (SLs), as a class of novel plant hormones, play important roles in the regulation of plant branching. However, their function in branch development of wintersweet remains unclear. In this study, a gene involved in SLs biosynthesis, CpD27, was identified and isolated from wintersweet. The sequence characteristics, expression patterns, subcellular localization, and functional analysis through heterologous expression in Arabidopsis thaliana were investigated. Multiple sequence alignment showed that CpD27 contains the conserved D27 protein domain DUF4033. Quantitative real-time PCR analysis revealed that CpD27 is expressed in various vegetative organs of wintersweet, with the highest expression in leaves, followed by axillary buds. It is also expressed in all floral organs, with the highest expression level in the outer petals. CpD27 expression is induced by hormones (ABA and ACC) and low temperature (4 °C). Subcellular localization analysis indicated that CpD27 is localized in the chloroplasts of Arabidopsis. Heterologous expression of CpD27 in Arabidopsis delayed bolting. The number of both rosette branches and cauline branches in transgenic plants was reduced compared with wild-type plants. In addition, the expression of AtBRC1 was significantly upregulated in transgenic lines, suggesting that CpD27 has a function similar to that of its homolog in Arabidopsis. Overall, these results indicate that CpD27 plays a conserved role in the SLs-mediated branching pathway, which regulates branch development in wintersweet. This study provides a molecular and theoretical basis for further understanding branch development in wintersweet. Full article

Background/Objectives: Persons living with dementia (PLwD) receive informal care services from loved ones, commonly referred to as care partners (CPs). While the symptoms (e.g., depressive affect, cognitive impairment) experienced by PLwD are recognized to influence CP wellbeing, longitudinal investigations into the association of CP QoL and PLwD symptoms have yet to be fully explored. The present study sought to address this gap and highlight how CP QoL and PLwD symptoms systematically covary over time. Methods: Participants were composed of 33 dyads (PLwD and their CP) who partook in the Voices in Motion project, a social-cognitive intervention for dementia. CP QoL (WHOQOL-BREF), PLwD depressive symptomology (Patient Health Questionnaire-9) and PLwD global cognitive functioning (Mini-Mental State Examination) were assessed every three to four weeks in an intensive repeated-measures design. Time-varying covariation models using multilevel modeling examined systematic covariation between CP QoL and PLwD symptoms between and within dyads. Results: Increased CP psychological and social QoL were both associated with increased PLwD global cognitive functioning between dyads and vice versa (p < 0.05). Within dyads, increased CP social QoL was associated with improved PLwD depressive symptoms (p < 0.05), while increased CP environmental QoL was associated with increased depressive symptoms (p < 0.05). Conclusions: Significant coupling associations were observed both between and within dyads. Such results highlight the association between CP QoL and the symptoms experienced by their care recipient and provide important, novel longitudinal contributions to the literature. Full article

Diamane, a fully sp³-hybridized two-dimensional carbon allotrope, has attracted attention due to its exceptional mechanical strength, tunable electronic properties, and potential for nanoelectronic and nanomechanical applications. While most studies focus on semi-functionalized (50% surface functionalization) C₄X₂ diamane, the stability and properties of configurations with lower functional group coverage remain unexplored. Here, we propose a novel diamane structure with 25% surface functionalization, denoted as C₄X (X = H, F, OH, NH₂), crystallizing in the P6/mmm space group. Using first-principles calculations, we systematically investigate the effects of different functional groups on the electronic and mechanical properties. Our results show that the bandgap can be effectively tuned from 2.97 to 3.42 eV, with C₄F and C₄OH exhibiting wider gaps due to strong C-p and O(F)-p orbital hybridization. C₄H and C₄NH₂ possess high electron mobilities on the magnitude order of of ${10}^3$ cm² V⁻¹ s⁻¹. Mechanically, C₄H demonstrates a Young’s modulus up to 614 GPa and a shear modulus of 274 GPa, underscoring its exceptional mechanical robustness. This work uncovers a previously unexplored low-coverage diamane configuration, highlighting the crucial role of surface chemistry in modulating electronic and mechanical behavior, and provides a promising design strategy for high-performance carbon-based nanoelectronic and nanomechanical devices. Full article

Aim: The aim of this study was to correlate single-nucleotide polymorphisms (SNPs) in the FTO and MC4R genes with body composition (BC) in populations with various levels of physical activity, and to investigate associations of SREBF1 methylation with the level of physical activity (PA) and BC. Methods: Fifty-six participants aged 18–65 years old with no underlying medical conditions were included in the study and were classified into sedentary/light PA (SLPA), moderate PA (MPA) and vigorous PA (VPA) groups using the International PA questionnaire (IPAQ). Anthropometric measures such as age, gender, body mass index (BMI) and body fat percentage (BFP) were recorded at the time of recruitment. Venous blood samples were collected during participant recruitment and DNA was extracted. Genotyping assays were performed for SNPs in FTO (rs9939609) and MC4R (rs17782313) using Taqman^® RT qPCR and TaqMan Genotyper software 1.7.1. Methylation analysis assay for CpG sites in the SREBF1 gene was performed on 56 samples using PyroMark^® Q48 Autoprep (Qiagen, Venlo, The Netherlands). The results were statistically analysed to identify any associations between FTO/MC4R genotypes and the level of PA, and between SREBF1 methylation status and the level of PA. This is the first study to investigate links between PA and quantitative methylation of SREBF1. Results: According to IPAQ guidance, the 56 participants were classified into SLPA n = 14, MPA n = 11 and VPA n = 31. The correlation analysis revealed that the FTO rs9939609 ‘A’ risk allele had a significant negative association with BFP in the VPA group (p = 0.0387); the MC4R rs17782313 ‘C’ risk allele had a significant positive association with BMI in the VPA group (p = 0.0256). In the SREBF1 pyrosequencing analysis, higher levels of methylation were observed in the VPA group (p = 0.07). Conclusions: We concluded that SNPs associated with obesity identified in FTO rs9939609 and MC4R rs17782313 could help to predict the molecular effects of PA. A high frequency of FTO risk variants in the cohort was observed and the VPA group could help maintain a healthy BFP. Full article

Calcium leaching increases the hydraulic concrete material’s porosity and the diffusion coefficient, thereby jeopardizing engineering safety. Fly ash and silica fume are commonly used mineral admixtures in hydraulic concrete, and their effects on the material’s leaching characteristics, especially its microstructural and transport properties, require further investigation. In this study, calcium leaching tests were conducted on cement paste (CP), silica fume–cement paste (SF), and fly ash–cement paste (FA) using a 6 mol/L ammonium chloride solution to accelerate the leaching process. Subsequently, a series of quantitative and qualitative analyses was performed on the deteriorated specimens, including phenolphthalein indicator spraying, X-ray diffraction (XRD), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM). Additionally, the diffusion coefficients of the material at different locations were calculated and analyzed. The results show that partially replacing cement with silica fume or fly ash increases the initial porosity, gel pore content, and initial diffusion coefficients. After 28 days of leaching, compared to the initial values, the porosity increases in the 0–4 mm layer from the leached surface were 83.6% for CP, 11.0% for SF, and 39.0% for FA. The diffusion coefficients increased by factors of 14.3 (CP), 6.1 (SF), and 13.6 (FA), indicating enhanced resistance to leaching. The primary reason for this is that the reactive silica in the admixtures undergoes a pozzolanic reaction with the calcium hydroxide generated by cement hydration, producing additional calcium silicate hydrate (C-S-H) gel, which reduces the capillary pores that would otherwise result from calcium hydroxide decomposition. Full article

This study aimed to identify areas at risk of deforestation in the Cerrado biome of the Brazilian Midwest (states of Mato Grosso, Mato Grosso do Sul, and Goiás) and to estimate potential soil losses due to water erosion under land-use change scenarios. The methodology integrated the Universal Soil Loss Equation (USLE), spatializing rainfall erosivity (R), soil erodibility (K), topographic factor (LS), and cover-management factor (CP), with the ACEU (Accessibility, Cultivability, Extractability and Unprotected/protection status) model to assess deforestation risk based on accessibility, agricultural suitability, extractive activities, and legal protection status. Results indicated an average soil loss of 0.11 t ha⁻¹ year⁻¹ under natural vegetation cover, with 90% of the area presenting losses below 0.25 t ha⁻¹ year⁻¹. However, 27.5% of the remaining natural cover is located in areas classified as high or very high deforestation risk, indicating significant environmental vulnerability. Simulated scenarios of land-use conversion to pasture and annual crops revealed substantial increases in soil loss, particularly under annual cropping systems, potentially exceeding soil loss tolerance thresholds across millions of hectares. The findings demonstrate that integrating deforestation risk assessment with erosion modeling is a strategic tool for environmental planning, reinforcing the importance of preserving native vegetation to maintain ecosystem services and ensure long-term environmental sustainability. Full article

High-viscosity sodium alginate solutions (4.5% by mass, apparent viscosity 1 × 10⁴–2 × 10⁴ cP) are widely used in the preparation of hydrogels, wet spinning, and biomedical materials. Residual bubbles can cause internal voids in hydrogels, mechanical heterogeneity, fiber breakage during spinning, and reduced strength, and can severely affect the cell compatibility and clinical safety of biomaterials. Due to the difficulty of bubble migration, coalescence, and rupture in high-viscosity systems, traditional vacuum-standing degassing takes up to 24 h and is extremely inefficient, severely limiting the quality of subsequent processing. To address this issue, this study proposes a novel vacuum-assisted centrifugal recirculating degassing method for highly viscous sodium alginate solutions and aims to establish a kinetic framework for describing its overall degassing behavior. Using the number density of bubbles larger than 0.5 mm in diameter as an evaluation metric, we conducted vacuum-standing control experiments and univariate experiments with different screen mesh apertures (5, 1.5, 0.3, and 0.07 mm). We experimentally verified a continuous kinetic model of bubble number decay based on vacuum bubble expansion, centrifugally enhanced migration, and removal probability during the cycle. The results indicate that the bubble removal effect of 40 min of vacuum–centrifugal cyclic degassing is equivalent to that of 4 h of vacuum static settling, representing a 450% increase in degassing efficiency. There is an optimal range for a screen aperture, with the best degassing effect observed at 0.3 mm, achieving a bubble removal rate of 83.69%. The established kinetic model exhibits good fitting accuracy (RMSE = 0.17, MAPE = 5.9%) and can accurately predict degassing efficiency under different process conditions. This study provides a quantifiable, modelable, and optimizable process scheme for rapid degassing of high-viscosity sodium alginate solutions, and offers a theoretical reference for the development of degassing technologies for high-viscosity polysaccharide fluids. Full article

This study investigated the effects of dietary standardized ileal digestible (SID) lysine levels and amylose to amylopectin ratios on the intestinal health of broilers fed an 18.5% crude protein diet from 22 to 42 days of age. A total of 540 healthy male Ross 308 broilers were randomly assigned to nine treatments in a 3 × 3 factorial design consisting of three SID lysine levels (1.00%, 1.20%, and 1.40%) and three AM/AP ratios (0.19, 0.29, and 0.41), with six replicates of 10 birds each. Ileal morphology, intestinal barrier function and inflammation-related gene expression, and the composition of cecal microbiota were evaluated. Significant interactions between lysine level and AM/AP ratio were observed for Occludin, ZO-1, Claudin-1, and TNF-α expression, with the highest expression in the 1.40% lysine + 0.41 AM/AP group and the lowest in the 1.00% lysine + 0.19 AM/AP group. The VH/CD ratio showed a significant interaction, with the highest value in the 1.20% lysine + 0.19 AM/AP group and the lowest in the 1.40% lysine + 0.41 AM/AP group. IL-18 and IL-10 were primarily affected by the main effects of lysine and AM/AP ratio. The expression levels of both IL-10 and IL-18 increased with increasing lysine level and increasing starch AM/AP ratio. Dietary SID lysine level and AM/AP ratio interactively regulate the expression of barrier-related genes, inflammatory status, intestinal morphology, and cecal microbiota, potentially contributing to enhanced intestinal health in broilers. However, because microbial metabolites were not measured, the functional significance of the observed microbiota alterations remains speculative. In broilers fed an 18.5% CP diet, a combination of 1.20% SID lysine with an AM/AP ratio of 0.19 was identified as the optimal strategy for maintaining intestinal morphology from 22 to 42 days of age. Full article