Search Results (545)

The present study evaluates the electrochemical behaviour of reinforcing steel embedded in an alkali-activated eco-cellular geopolymer concrete designed for applications in environments with high chloride exposure. The material was formulated using a ternary precursor composed of fluid catalytic cracking residue (FCC), Class F fly ash, and ground granulated blast furnace slag (BFS), activated with an alkaline solution and combined with preformed foam to generate a microstructure characterised by predominantly closed porosity and low capillary connectivity. The electrochemical response of the system was assessed through open circuit potential (OCP) measurements, Tafel polarisation curves, electrochemical impedance spectroscopy (EIS), and potentiodynamic tests under accelerated exposure to NaCl solutions. The results demonstrate a markedly improved electrochemical performance, evidenced by shifts in OCP towards more noble values, reductions of 45–65% in corrosion current density (Icorr), and increases of up to fourfold in charge transfer resistance (Rct), together with the development of broader and more stable passive regions. This behaviour is attributed to the synergistic interaction between the formation of dense N-(C)-A-S-H (sodium/calcium–aluminosilicate hydrate) and C-(A)-S-H (calcium–aluminosilicate hydrate) gels, the eco-cellular architecture with low capillary connectivity, and the stable high alkalinity of the activated matrix, which collectively restrict ionic transport and promote the passive stability of the reinforcing steel—defined here by noble OCP values, low Icorr, high Rct, and sustained passive domains in polarisation curves. Overall, the findings position the developed eco-cellular geopolymer concrete as a sustainable, high-performance alternative for infrastructure exposed to chloride-rich environments. Full article

Background: Autologous bone graft is widely used for lumbar interbody fusion but may increase operative time and donor-site morbidity. Gene-activated grafts combining an osteoconductive scaffold with pro-angiogenic signaling may provide comparable fusion without graft harvesting. The aim of this paper is to compare radiographic fusion and health-related quality of life after single-level transforaminal lumbar interbody fusion (TLIF) using a gene-activated octacalcium phosphate graft containing plasmid DNA encoding vascular endothelial growth factor (OCP/VEGF) versus an autologous bone graft. Methods: 200 adults undergoing first-time single-level TLIF for degenerative lumbar stenosis were allocated 1:1 to OCP/VEGF (n = 100) or autograft (n = 100), prospectively. CT-based fusion assessment and SF-36 outcomes were evaluated at 6 and 12 months follow-up. Results: At 12 months after surgery, mean fusion-zone density was 617.6 ± 180.9 HU in the OCP/VEGF group versus 599.8 ± 181.9 HU in the autograft group (mean difference 17.8 HU; p = 0.484). Complete fusion on qualitative CT grading occurred in 77% versus 73%, respectively (risk difference 4%; p = 0.583). SF-36 Physical Component Summary (PCS) and Mental Component Summary (MCS) improved significantly from baseline in both groups (p < 0.001), without clinically meaningful between-group differences at follow-up. Revision surgery occurred in 3% versus 5%. Conclusions: In single-level TLIF for degenerative lumbar stenosis, OCP/VEGF produced radiographic fusion and patient-reported outcomes comparable to autograft at 12 months, supporting its use as an autograft-sparing alternative. Full article

The corrosion behavior and passive-film stability of a β-TiZrNbTa (β-TZNT) alloy were investigated in artificial seawater (ASW), focusing on the effects of pH, temperature, immersion time, fluoride ion concentration, and potential scan rate. In addition to electrochemical methods such as open-circuit potential (OCP), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed for surface characterization. The establishment of a stable and efficient passive layer enriched in Zr-, Nb-, and Ta-oxides was responsible for the β-TZNT alloy’s superior corrosion resistance in fluoride-free ASW when compared to commercially pure titanium. Reduced passive-film resistance resulted from corrosion kinetics being greatly accelerated by decreasing the pH and increasing the temperature. The presence of fluoride ions strongly affected the passivity of the alloy due to the chemical dissolution of TiO₂ through the formation of soluble fluoride complexes, resulting in an increase in the corrosion current densities by more than one order of magnitude. A bilayer passive structure with a compact inner barrier layer and a porous outer layer was identified by EIS analysis. The stability of this structure gradually decreased with increasing fluoride concentration and acidity. Over time, passive-film degradation was dominant in fluoride-free seawater, whereas prolonged exposure in fluoride-containing media promoted partial re-passivation. Overall, these results highlight the potential and limitations of the β-TZNT alloy for marine and offshore applications by offering new mechanistic insights into the synergistic effects of fluoride ions and environmental factors on corrosion performance. Full article

Urban parks are essential to sustainable cities, providing climate regulation, supporting biodiversity, and offering vital spaces for recreation and overall well-being. At the same time, their soils can act as long-term reservoirs for persistent organic pollutants (POPs), reflecting decades of atmospheric deposition, diffuse urban emissions, and historical land-use practices. This review synthesises current knowledge on the occurrence, sources, and environmental behaviour of priority POPs, including OCPs, PCBs, PCDD/Fs, PBDEs, PFAS, and PAHs, in the soils of urban parks and gardens worldwide. Evidence from multiple regions reveals consistent patterns: urban parks accumulate complex mixtures of legacy and emerging contaminants, reflecting both historical inputs and ongoing urban activities. These contaminants primarily contribute to scenarios of chronic, low-level exposure through the ingestion of soil and dust, inhalation of resuspended particles, dermal contact, and, in some cases, dietary intake when food is cultivated in contaminated park soils. While such exposure pathways have been associated with a range of adverse health outcomes in toxicological and epidemiological studies, the presence of POPs in park soils does not imply that urban parks represent hazardous environments. Instead, it emphasises the importance of proportionate, evidence-based assessments within spaces that yield substantial net benefits to public health. Despite growing research interest, significant gaps remain, including limited understanding of mixture toxicity, insufficient data on temporal trends, a lack of harmonised monitoring strategies, and the absence of exposure scenarios specifically tailored to recreational soils. This review also examines major international and European regulatory frameworks and soil-quality guideline approaches relevant to urban and recreational soils, identifying mismatches between scientific evidence and regulatory practice. By integrating perspectives from environmental chemistry, toxicology, urban ecology, and policy, this review highlights the importance of targeted monitoring and context-specific management strategies to ensure that urban parks remain safe, healthy, and equitable components of increasingly complex urban landscapes. Full article

The long-term durability and structural integrity of modern buildings, which are inherently reliant on reinforced concrete, are governed by the rate of corrosion of embedded steel reinforcement. Corrosion kinetics, therefore, is not merely an academic exercise, but rather a critical foundation for predicting and extending a structure’s life span, mitigating safety risks, and ensuring the sustainability of the built environment against a host of environmental and chemical degradation factors. The present study conducts a comparative analysis of the short-term corrosion initiation behavior of steel reinforcement embedded in three distinct types of geopolymer binders, a cementitious paste, and a cementitious composite with natural aggregates. Electrochemical techniques, such as Open Circuit Potential (OCP) and linear polarization tests were used to characterize the behavior of the steel reinforcement embedded in the 4 types of samples. Additionally, these samples containing the reinforcement were further characterized using advanced microstructural techniques, specifically porosimetry, Nuclear Magnetic Resonance (NMR), and Scanning Electron Microscopy (SEM). Full article

Antimicrobial resistance is a major global health concern, intensified by the misuse of antibiotics and the lack of new effective treatments. Bacteria capable of forming biofilms exhibit increased resistance, making infections more difficult to treat. This study evaluated the essential oil from Croton pluriglandulosus leaves (OCp) for its antibacterial and antibiofilm properties. The essential oil, obtained by hydrodistillation and analyzed by GC-MS, contained eucalyptol (24.11%), spathulenol (16.90%), α-pinene (11.76%), and caryophyllene oxide (10.07%) as main constituents. Antibacterial activity was determined by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC), with inhibition observed only for Staphylococcus aureus (MIC 10 mg/mL; MBC 5 mg/mL). OCp reduced biofilm biomass and CFUs in most strains, particularly in S. aureus and Escherichia coli. Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM) showed membrane damage in treated cells. Overall, OCp displayed promising antibacterial and antibiofilm potential, representing the first report of such activity for this essential oil. Full article

This paper proposes a novel method, the Convergent Radiation Algorithm (CRA), aimed at multi-attribute group decision-making (MAGDM) in circular intuitionistic fuzzy settings. The approach is aimed at reaching geometric consensus among experts, with uncertainties and hesitancies expressed via circular intuitionistic fuzzy numbers (CIFNs). First, the qualitative judgment in professionals is converted into a geometric space where experts’ assessments are represented as spatial points that reflect the differences between the opinions. All these points are gradually combined with the help of a radiation–reflection–convergence mechanism, which iteratively finds the Optimal Consensus Point (OCP) to minimize the overall weighted divergence over the evaluations. After that, a projection-based scoring method is used to locate good and bad optimal solutions, and the alternatives are ranked based on a comparison of their projection distance. It presents a numerical example with data supplied by the Hubei agro-ecological zone to demonstrate that the offered method helps to capture collective agreement and convergence behavior that is consistent, and makes the decision results readable and reliable. Full article

This study systematically analyzed the pollution levels, distribution characteristics, and associated health risks of 17 organochlorine pesticides (OCPs) and 9 polychlorinated biphenyls (PCBs) in Oviductus Ranae (Rana dybowskii) from major production areas in Heilongjiang Province, China. OCPs and PCBs were detected in all samples. The total concentration of OCPs ranged from 11.7 to 67.9 ng/g (dry weight), while that of total PCBs ranged from 4.43 to 8.06 ng/g. Endosulfans constituted the predominant OCP group, accounting for 54.5% of ∑OCPs, with an α/β-endosulfan ratio (~2:1) indicative of recent agricultural input. Among DDTs, the dominance of p,p′-DDE and the absence of parent DDT suggested aerobic degradation of historical residues. For HCHs, the isomer profile (β-HCH predominance, α/γ-HCH = 0.27) pointed to weathered lindane sources. The PCB profile was uniquely dominated by lower-chlorinated congeners (PCB1 and PCB29), implying influences from atmospheric transport and/or in situ microbial dechlorination of legacy PCBs. The persistent organic pollutants (POPs) contamination profile in Oviductus Ranae reflects a combined influence of recent pesticide application, weathered historical residues, and long-range transport. Although the concentrations are below current regulatory limits, the cumulative and persistent nature of these POPs, coupled with the product’s medicinal use, justifies a precautionary stance regarding long-term consumption. The distinct congener patterns underscore the necessity for future research to prioritize the environmental behavior and toxicology of dominant transformation products within such specific agro-ecosystems. Full article

Coastal zones, as critical ocean–land–atmosphere ecotones, face significant ecological threats from persistent organic pollutants like organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). However, there are still obvious deficiencies in the understanding of the pollution characteristics and ecological risks of OCPs and PCBs in the coastal environment of South China, especially in western Guangdong. Due to the absence of prior research on these pollutants in the Maoming area, we measured the grain sizes from 157 sediment samples and the concentrations of PCBs and OCPs from 11 key locations to assess their environmental occurrence and risks. As analyzed by the GC-MS system, OCP levels range from 0.39 to 50.20 ng/g (mean 10.25 ng/g), while PCB concentrations range from 1.6 to 92.59 ng/g. Through the analysis of pollutant data and analysis of similar areas, we found that OCPs and PCBs in the Maoming coastal zone primarily originate from fishing port operations, ship antifouling paints, and historical legacy pollutants. In addition, the distribution of pollution is significantly controlled by hydrodynamic conditions and the semi-enclosed geomorphological characteristics of the bay. As grain size increases, the correlation with pollutant concentrations shifts from positive to negative. This trend reveals that finer-grained sediments in low-energy environments accumulate significantly higher levels of pollution compared to their coarser counterparts in more dynamic settings. Compared to other coastal regions globally, the study area demonstrates relatively lower pollution intensity. Dual assessments using Sediment Quality Guidelines (SQGs) and Sediment Quality Standards (SQSs) indicate a generally low probability of adverse biological effects, with elevated risk localized to sites near port activities. This study provides a scientific basis for the prevention and control of OCP and PCB pollution in the Maoming coastal zone and also provides a reference for pollution assessment in similar areas. Full article

The clinical success of calcium phosphate bone grafts (CPs) largely depends on the body’s immune response. However, traditional biocompatibility tests use healthy organisms and cannot predict effectiveness in patients with common chronic inflammatory diseases. This study examines how inflammation modulates the immune response, in vitro and in vivo, to low-temperature biomimetic CPs: dicalcium phosphate dihydrate (DCPD), octacalcium phosphate (OCP), and hydroxyapatite (HAp). In vitro studies involved human monocytes, macrophages, lymphocytes, and mesenchymal stromal cells (MSCs), with or without pro-inflammatory activation. In vivo biocompatibility was assessed via subcutaneous implantation in rats, with or without Complete Freund’s Adjuvant (CFA)-induced inflammation. Under normal conditions, all CP caused minimal immune reactivity. Inflammation-activated macrophages, however, triggered an acute reaction with significantly increased TNF-α and IL-1β secretion. Healthy and inflamed animals showed sharp contrasts. Although all materials exhibited thickened fibrous capsules during inflammation, biocompatibility varied markedly: DCPD performed best by promoting angiogenesis with minimal inflammation; HAp provoked the most severes response, including tissue necrosis and signs of rejection; OCP showed intermediate effects, with angiogenesis but notable fibrosis. Inflammatory processes critically influence CP biocompatibility; materials biocompatible in healthy organisms can induce fibrosis or rejection under inflammation. Disease-relevant, immune-challenged models are essential to predict clinical efficacy and safety. Full article

Recent studies support that hematopoietic stem cell (HSC)-derived myeloid dendritic cells, monocytes/macrophages (Mo/Mϕ), and osteoclast precursors (OCps) share common progenitor(s) during development. This occurs mainly through receptor activator of NF-κB ligand (RANKL) signaling via its cytoplasmic adaptor protein complex (TRAF6) to subsequent osteoclastogenesis for bone loss and/or remodeling. Presently, mounting new evidence suggests that erythro-myeloid progenitor (EMP)-derived macrophages (Mϕ) and HSC-derived monocytes (Mo) produce embryonic, fetal, and postnatal OCp pools (i.e., primitive OCp), pinpointing a complex network of multiple OCp developmental origins. However, their ontogenic developments, lineage interactions, and contributions to the alternative osteoclastogenesis—in contrast to overall bone remodeling or loss—remain elusive. Interestingly, studies have also elucidated the contributions of immature CD11c⁺ myeloid DC-like OCps to osteoclastogenesis, with or without the classical so-called Mo/Mϕ-derived OCp subsets, and described that CD11c⁺ myeloid DCs (mDCs) develop into functionally active OCs; meanwhile, the cytokine TGF-β mediates a stepwise regulation of de novo immature mDCs/OCps through distinct crosstalk(s) with IL-17, an unrecognized interaction featuring TRAF6^(−/−)CD11c⁺ mDDOCps that coexist and proficiently colocalize in the local environment to drive a bona fide route for alternative osteoclastogenesis in vivo. Collectively, new findings—critically hinged on progenitor osteoclastogenic pathways (primitive OCps, mDCs/OCps, osteomorphs, etc.) and involving classical and/or alternative routes to inflammation-induced bone loss—are discussed via the illustrated schemes. This review highlights plausible ontogenic vs. principal or alternative developmental paths and their consequential downstream effects. Full article

This study explores the relationships among companionate love (a collective, non-romantic emotional culture expressed through care, compassion, and tenderness at work), organizational culture practices (OCPs), work engagement, and burnout among 649 Brazilian workers. Using a quantitative, exploratory, and correlational design, data were analyzed through descriptive statistics, group comparisons, and network modeling. Results indicated strong positive associations among companionate love, OCP, and work engagement, as well as negative associations with burnout. Companionate love was most strongly associated with OCP, suggesting that emotionally expressive work environments are linked to the perception of supportive organizational practices. Work engagement emerged as a central relational node in the network, connecting emotional culture and burnout. Group comparisons showed higher engagement among postgraduate professionals and managers, and higher OCP perceptions among remote workers and employees in the private sector, although effect sizes were small. Network centrality analyses identified OCP and engagement as key relational influencers within the system. Overall, the findings highlight the relevance of emotional culture and organizational practices for workplace well-being and suggest relational pathways through which engagement may be linked to lower burnout in organizational contexts. Full article

As a key freshwater wetland in the Beijing–Tianjin–Hebei core area, Baiyangdian Lake’s ecological health is strategically significant for regional ecological security, prompting this study to explore how sediment phosphorus forms drive its phytoplankton communities. The research adopted sequential extraction technology, morphological identification, and multivariate statistics in Baiyangdian Lake. Results showed sediment phosphorus was dominated by highly active exchangeable phosphorus (Ex-P, ~60%, with higher levels around villages of lake center and western areas), with occluded phosphorus (Oc-P, ~23%) as the second most abundant form. Ex-P was the core factor shaping phytoplankton communities, directly increasing biomass density (r = 0.38, p < 0.05) and explaining 17.92% of community variation. Bacillariophyta was the dominant group (43.3%), while calcium-bound phosphorus (Ca-P) maintained diversity and aluminum-bound phosphorus (Al-P) inhibited evenness (r = −0.35, p < 0.05). Active phosphorus directly affected, and inactive phosphorus indirectly regulated, phytoplankton patterns, clarifying the unique phosphorus structure of northern carbonate-type lakes and filling research gaps. It is suggested to include Ex-P and Ca-P in aquatic ecological monitoring and prioritize sediment passivation and riparian restoration in high-Ex-P areas to mitigate algal bloom risks. Full article

Ti-6Al-4Zr-3Nb-1.1Mo-1Sn-1V (Ti90) alloy is widely used in marine engineering and oil and gas extraction due to its excellent strength, impact toughness, and corrosion resistance. The corrosion behavior of Ti90 alloy after solution treatment at 750 °C, 900 °C, 940 °C, and 960 °C in 5 M hydrochloric acid (HCl) solution was investigated using open-circuit potential (OCP), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), static immersion tests, and surface characterization. The results of electrochemical tests indicate that the corrosion resistance of Ti90 alloy increases with rising solid solution temperature. The static immersion tests show that the variation trend of the annual corrosion rate at different solid solution temperatures in 5 M HCl solution is consistent with the electrochemical test results. The corrosion morphology of Ti90 alloy reveals that the α phase is more prone to decomposition than the β phase. The corrosion behavior of Ti90 alloy in 5 M HCl solution is mainly influenced by the volume fraction of the β phase and the size of the α phase. Full article

This study aims to evaluate the corrosion inhibition performance of different types of inhibitors for steel reinforcement in cement paste under accelerated carbonation conditions. Electrochemical methods, including electrochemical impedance spectroscopy EIS, linear polarization resistance LPR, and open-circuit potential OCP measurements, were utilized on specimens with various inhibitor formulations during exposure to a high-CO₂ environment. The results indicate that composite inhibitors provide the greatest protection, significantly outperforming single-component anodic or cathodic inhibitors. Among anodic inhibitors, sodium molybdate showed more effective corrosion inhibition than sodium chromate, and among cathodic inhibitors, BTA was more effective than DMEA, as evidenced by higher polarization resistance and more stable passivation. After 120 days of carbonation, the specimen with the optimal composite inhibitor remained passive with a low corrosion rate and a relatively noble steel potential, whereas the uninhibited specimen exhibited active corrosion. Full article