RÉSUMÉ
BACKGROUND: Fiberglass has a larger aerodynamic diameter and is less likely to be inhaled into the lungs. Further, it will be cleared even if it is mechanically broken into smaller pieces and inhaled into the lungs. Fiberglass lung disease has been well documented if long term exposure but was thought reversible and would not cause severe diseases. The diagnosis of fiberglass lung disease depends on exposure history and histopathological findings. However, the exact occupational exposure history is often difficult to identify because mixed substance exposure often occurs and fiberglass disease is not as well-known as asbestosis. CASE PRESENTATION: A 66-year-old man had unexplained transudative pericardial effusion requiring pleural pericardial window operation twice at another medical center where asbestosis was told because of his self-reported long-term asbestosis exposure and the histopathological finding of a ferruginous body in his lung. Constrictive pericarditis developed two years later and resulted in congestive heart failure. Radical pericardiectomy combined with lung biopsy was performed following chest computed tomography imaging and the transudative nature of pericardial effusion not compatible with asbestosis. However, the histopathologic findings of his lung and pericardium at our hospital only showed chronic fibrosis without any asbestosis body. The patient's lung was found to be extremely fragile during a lung biopsy; histopathologic specimens were reviewed, and various fragments of fiberglass were found in the lung and pericardium. The patient's occupational exposure was carefully reevaluated, and he restated that he was only exposed to asbestosis for 1-2 years but was heavily exposed to fiberglass for more than 40 years. This misleading exposure history was mainly because he was only familiar with the dangers of asbestos. Since most fiberglass lung diseases are reversible and the symptoms of heart failure resolve soon after surgery, only observation was needed. Ten months after radical pericardiectomy, his symptoms, pleural effusion, and impaired pulmonary function eventually resolved. CONCLUSION: Fiberglass could cause inflammation of the pericardium, resulting in pericardial effusion and constrictive pericarditis, which could be severe and require radical pericardiectomy. Exact exposure history and histopathological examinations are the key to diagnosis.
Sujet(s)
Verre , Exposition professionnelle , Péricardite constrictive , Humains , Mâle , Péricardite constrictive/étiologie , Péricardite constrictive/diagnostic , Péricardite constrictive/chirurgie , Sujet âgé , Exposition professionnelle/effets indésirables , Asbestose/complications , Asbestose/diagnostic , Asbestose/anatomopathologie , Tomodensitométrie , Poumon/anatomopathologie , Poumon/imagerie diagnostique , Péricardectomie , Épanchement péricardique/étiologieRÉSUMÉ
The development of well-adherent, amorphous, and bioactive glass coatings for metallic implants remains a critical challenge in biomedical engineering. Traditional bioactive glasses are susceptible to crystallization and exhibit a thermal expansion mismatch with implant materials. This study introduces a novel approach to overcome these limitations by employing systematic Na2O substitution with CaO in borosilicate glasses. In-depth structural analysis (MD simulations, Raman spectroscopy, and NMR) reveals a denser network with smaller silicate rings, enhancing thermal stability, reducing thermal expansion, and influencing dissolution kinetics. This tailored composition exhibited optimal bioactivity (in vitro formation of bone-like apatite within 3 days) and a coefficient of thermal expansion closely matching Ti-6Al-4V, a widely used implant material. Furthermore, a consolidation process, meticulously designed with insights from crystallization kinetics and the viscosity-temperature relationship, yielded a crack-free, amorphous coating on Ti-6Al-4V substrates. This novel coating demonstrates excellent cytocompatibility and strong antibacterial action, suggesting superior clinical potential compared with existing technologies.
Sujet(s)
Matériaux revêtus, biocompatibles , Verre , Titane , Verre/composition chimique , Matériaux revêtus, biocompatibles/composition chimique , Matériaux revêtus, biocompatibles/pharmacologie , Titane/composition chimique , Prothèses et implants , Antibactériens/composition chimique , Antibactériens/pharmacologie , Test de matériaux , Propriétés de surface , Alliages/composition chimique , HumainsRÉSUMÉ
Mesoporous bioactive glass nanoparticles (MBGNs) doped with therapeutical ions present multifunctional systems that enable a synergistic outcome through the dual delivery of drugs and ions. The aim of this study was to evaluate influence of co-doping with strontium and magnesium ions (SrMg-MBGNs) on the properties of MBGNs. A modified microemulsion-assisted sol-gel synthesis was used to obtain particles, and their physicochemical properties, bioactivity, and drug-loading/release ability were evaluated. Indirect biological assays using 2D and 3D cell culture models on human bone marrow-derived mesenchymal stem cells (hBM-MSCs) and endothelial EA.hy926 cells, respectively, were used to determine biocompatibility of MBGNs, their influence on alkaline phosphatase (ALP) production, calcium deposition, and cytoskeletal organization. Results showed that Sr,Mg-doping increased pore volume and solubility, and changed the mesoporous structure from worm-like to radial-dendritic, which led to a slightly accelerated drug release compared to pristine MBGNs. Biological assays confirmed that particles are biocompatible, and have ability to slightly induce ALP production and calcium deposition of hBM-MSCs, as well as to significantly improve the proliferation of EA.hy926 compared to biochemical stimulation via vascular endothelial growth factor (VEGF) administration or regular media. Fluorescence staining revealed that SrMg-MBGNs had a similar effect on EA.hy926 cytoskeletal organization to the VEGF group. In conclusion, Sr,Mg-MBGNs might be considered promising biomaterial for biomedical applications.
Sujet(s)
Régénération osseuse , Systèmes de délivrance de médicaments , Verre , Magnésium , Cellules souches mésenchymateuses , Nanoparticules , Strontium , Humains , Régénération osseuse/effets des médicaments et des substances chimiques , Nanoparticules/composition chimique , Strontium/composition chimique , Strontium/pharmacologie , Cellules souches mésenchymateuses/effets des médicaments et des substances chimiques , Cellules souches mésenchymateuses/métabolisme , Cellules souches mésenchymateuses/cytologie , Porosité , Magnésium/composition chimique , Verre/composition chimique , Systèmes de délivrance de médicaments/méthodes , Libération de médicament , Lignée cellulaire , Matériaux biocompatibles/composition chimique , Matériaux biocompatibles/pharmacologie , Prolifération cellulaire/effets des médicaments et des substances chimiquesRÉSUMÉ
The ability of bacteria to colonize diverse environmental niches is often linked to their competence in biofilm formation. It depends on the individual characteristics of a strain, the nature of the colonized surface (abiotic or biotic), or the availability of certain nutrients. Pseudomonas donghuensis P482 efficiently colonizes the rhizosphere of various plant hosts, but a connection between plant tissue colonization and the biofilm formation ability of this strain has not yet been established. We demonstrate here that the potential of P482 to form biofilms on abiotic surfaces and the structural characteristics of the biofilm are influenced by the carbon source available to the bacterium, with glycerol promoting the process. Also, the type of substratum, polystyrene or glass, impacts the ability of P482 to attach to the surface. Moreover, P482 mutants in genes associated with motility or chemotaxis, the synthesis of polysaccharides, and encoding proteases or regulatory factors, which affect biofilm formation on glass, were fully capable of colonizing the root tissue of both tomato and maize hosts. Investigating the role of cellular factors in biofilm formation using these plant-associated bacteria shows that the ability of bacteria to form biofilm on abiotic surfaces does not necessarily mirror its ability to colonize plant tissues. Our research provides a broader perspective on the adaptation of these bacteria to various environments.
Sujet(s)
Biofilms , Carbone , Pseudomonas , Biofilms/croissance et développement , Pseudomonas/physiologie , Pseudomonas/métabolisme , Pseudomonas/génétique , Carbone/métabolisme , Racines de plante/microbiologie , Rhizosphère , Solanum lycopersicum/microbiologie , Zea mays/microbiologie , Verre , Adhérence bactérienne , Glycérol/métabolisme , PolystyrènesRÉSUMÉ
The present work investigates the structural and luminescence behaviour of Dy3+-Sm3+ co-doped glass ceramics obtained through heat treatment of precursor glasses. The growth of SiO2 polycrystalline particles and evolution of these crystallites in the glass domain are witnessed via XRD and FESEM study. The presence of network vibrational bands, hydroxyl groups and the increased quantity of bridging oxygens (BOs) in glass ceramics are analysed through FTIR spectroscopy study. The absorption study (UV-Visible-NIR) showed the possible electronic transitions of Dy3+ and Sm3+ ions. The red shift in the absorption band edges and the lower bandgap values are obtained as a result of improved heat treatment in glass ceramics. Emission studies show the enhanced luminescence intensity of glass ceramics under 350 and 402 nm excitations. Decay measurement of glass ceramics showed the improved lifetimes of Dy3+ and Sm3+ ions to have appeared in microseconds (×10-6 s). The colour characteristics of glass ceramics analysed using CIE colour chromaticity diagram and correlated colour temperature (CCT) values suggest the neutral to cool white light emissions. Therefore, prepared glass ceramics with SiO2 polycrystalline phase are considered to be suitable materials in cool white LEDs applications.
Sujet(s)
Céramiques , Cristallisation , Dysprosium , Luminescence , Samarium , Silice , Céramiques/composition chimique , Silice/composition chimique , Dysprosium/composition chimique , Samarium/composition chimique , Lumière , Verre/composition chimiqueRÉSUMÉ
An intense cathodic electrochemiluminescence (ECL) is reported from a polarized glassy carbon electrode (GCE) in peroxydisulfate solution. After the polarization in 1 M Na2SO4 at the potential of - 3.7 V for 3 s, carbon nanosheets (C-NSs) were in situ grown on the surface of the GCE. Measured in 100 mM K2S2O8 solution, the ECL intensity of the GCE/C-NSs is 112-fold that of a bare GCE. The ECL spectrum revealed that the true ECL luminophore in the GCE/C-NSs-peroxydisulfate system is O2/S2O82- which is promoted by C-NSs. When Cu2+ was electrochemically enriched and reduced to Cu(0) on the catalytic sites of C-NSs, the ECL from GCE/C-NSs/Cu in K2S2O8 solution was decreased with increasing logarithmic concentration of Cu2+ in the range from 10 pM to 1 µM, with a limit of detection (LOD) of 3 pM. An immunoanalysis method is proposed via a biometallization strategy using CuS nanoparticles as the tags and carcinoembryonic antigen (CEA) as the model analyte. After the immune recognition in the microplate, the CuS tags in the immunocomplex were dissolved and the resultant Cu2+ was electrochemically enriched and reduced on the catalytic sites of C-NSs, quenching the ECL intensity of GCE/C-NSs-O2/S2O82- system. The proposed ECL immunoanalysis method was used to quantify CEA in actual serum samples with an LOD of 1.0 fg mL-1, possessing the advantages of simple electrode modification, high sensitivity and good reproducibility.
Sujet(s)
Carbone , Antigène carcinoembryonnaire , Cuivre , Techniques électrochimiques , Électrodes , Mesures de luminescence , Carbone/composition chimique , Mesures de luminescence/méthodes , Techniques électrochimiques/méthodes , Techniques électrochimiques/instrumentation , Antigène carcinoembryonnaire/sang , Antigène carcinoembryonnaire/immunologie , Antigène carcinoembryonnaire/analyse , Cuivre/composition chimique , Limite de détection , Humains , Nanostructures/composition chimique , Dosage immunologique/méthodes , Sulfate de cuivre/composition chimique , Nanoparticules métalliques/composition chimique , Verre/composition chimique , Sulfates/composition chimiqueRÉSUMÉ
In response to global challenges in resource supply, many industries are adopting the principles of the Circular Economy (CE) to improve their resource acquisition strategies. This paper introduces an innovative approach to address the environmental impact of waste Glass Fiber Reinforced-Polymer (GFRP) pipes and panels by repurposing them to manufacture structural components for new bicycle and pedestrian bridges. The study covers the entire process, including conceptualization, analysis, design, and testing of a deck system, with a focus on the manufacturing process for a 7-m-long prototype bridge. The study shows promising results in the concept of a sandwich structure utilizing discarded GFRP pipes and panels, which has the flexibility to account for variabilities in dimensions of incoming products while still meeting mechanical requirements. The LCA analysis shows that the transportation of materials is the governing contributing factor. It was concluded that further development of this concept should be accompanied by a business model that considers the importance of the contributions from the whole value chain.
Sujet(s)
Polymères , Polymères/composition chimique , Recyclage , Piétons , Transports , Verre/composition chimiqueRÉSUMÉ
BACKGROUND: Pressure offloading is a critical component of plantar foot ulcer management, including diabetes-related foot ulcers (DFU). Conventional offloading options such as total contact casting and removable knee-high walkers may be unsuitable or unsuccessful in patients with morbid obesity, intermittent lower limb oedema, high exudative wounds or poor mobility. A mouldable fibreglass backslab device (BSD) may be a practical alternative to be considered in these situations. METHODS: Data were retrospectively collected on 28 patients (29 foot ulcers) with non-healing ulcers who received a BSD to offload their foot ulcer as an extension to standard offloading care. Baseline data included: patient demographics, type of offloading prior to BSD application, date of ulcer onset, days ulcer present prior to BSD application and ulcer size at BSD initiation. Measures of success included ulcer size reduction 12 weeks post-BSD application, time to complete ulcer healing in BSD, time to 50% reduction in ulcer size post-BSD application and total number of days ulcer present. RESULTS: The median (IQR) ulcer area and ulcer duration at baseline for 19 patients (20 ulcers) who used the BSD was 1.65 (0.4-3.8) cm2 and 531 (101-635) days. At 12 weeks, the median (IQR) ulcer area was 0.3 (0-0.55) cm2 with a median (IQR) reduction of 97 (80-100) %. Nine (45%) ulcers achieved complete wound healing (100% reduction in wound size) at 12 weeks post-BSD application, and the remaining 11 (55%) ulcers achieved at least 50% reduction in wound size. The median (IQR) time to complete wound healing and 50% reduction in wound size was 71 (35-134) days and 24 (15-44) days, respectively. Nine patients ceased use of the BSD and reverted to conventional offloading before their wounds had healed. Of these, four patients achieved a 50% reduction in wound size at the 12-week mark with conventional offloading. CONCLUSION: Our preliminary data suggests that a mouldable fibreglass BSD may be a practical offloading option in the management of DFUs, especially when conventional offloading methods are unsuccessful, unsuitable or unacceptable to patients. Higher level evidence is required to demonstrate suitability or efficacy of the BSD compared to current evidence-based recommended offloading methods.
Sujet(s)
Pied diabétique , Cicatrisation de plaie , Humains , Études rétrospectives , Mâle , Femelle , Adulte d'âge moyen , Sujet âgé , Pied diabétique/thérapie , Ulcère du pied/thérapie , Verre , Mise en charge/physiologie , Résultat thérapeutique , Maladie chronique , Orthèses de pied , Conception d'appareillageRÉSUMÉ
In a joint study carried out by Gerresheimer, Sterigenics and Früh, it could be shown that also NO2 is well suited to terminally sterilize prefilled ophthalmic syringes. In detail 5 topics were addressed: (1) Compare EtO vs. NO2 penetration into the filled syringe; (2) Analyze gas ingress though 4 different plunger stoppers including silicone oil free and standard rubber plungers; (3) Scrutinize gas ingress through 2 different cap designs based on different elastomer properties; (4) Investigate gas permeation through COP plastic barrels compared to glass; (5) Check if the Tyvek®-layer has an influence on either sterilization.Depending on the needs a suitable sterilization method, packaging and syringe type can be suggested to customers.
Sujet(s)
Emballage de médicament , Stérilisation , Seringues , Stérilisation/méthodes , Emballage de médicament/normes , Emballage de médicament/méthodes , Administration par voie ophtalmique , Conception d'appareillage , Solutions ophtalmiques/administration et posologie , VerreRÉSUMÉ
Luer systems, for example Luer-needle hub with syringe's Luer cone tip and its Luer lock Adapter, are common interface on medical devices. One of the key questions in this application is about the safety guaranty and dose accuracy. It is then crucial to study the sealing between these elements. In this study we combine the use of Finite Element Analysis (FEA) and Multiscale Contact Mechanics (MCM) to analyze the connectivity and sealing performance of a glass syringe and a plastic needle Luer hub.This methodology has been applied before to the contact between glass and rubber and this is the first time that it is used for the contact between glass and plastic materials. The use of FEA allows to calculate the contact pressures and the nominal area of contact. The surface topographies of the two surfaces were measured, over a wide wavelength range (mm to nm). Subsequently, the air and liquid interfacial flow (leakage) is calculated using Persson's MCM theory which considers the roughness and elasto-plasticity of the interfacial surfaces. The theoretical predictions are compared to experimental leak measurements by pressure decay method. Further analysis is conducted, evidencing the key features that are responsible for a good sealing.
Sujet(s)
Analyse des éléments finis , Verre , Seringues , Verre/composition chimique , Conception d'appareillage , Propriétés de surface , Aiguilles , Caoutchouc/composition chimique , Matières plastiques/composition chimique , PressionRÉSUMÉ
Surface-enhanced Raman spectroscopy (SERS) is a powerful technique for discrimination of bimolecules in complex systems. However, its practical applications face challenges such as complicated manufacturing procedures and limited scalability of SERS substrates, as well as poor reproducibility during detection which compromises the reliability of SERS-based analysis. In this study, we developed a convenient method for simultaneous fabrication of massive SERS substrates with an internal standard to eliminate the substrate-to-substrate differences. We first synthesized Au@CN@Au nanoparticles (NPs) which contain embedded internal standard molecules with a single characteristic peak in the Raman-silent region, and then deposited the NPs on 6 mm glass wafers in a 96-well plate simply by centrifugation for 3 min. The one-time obtained 96 SERS substrates have excellent intrasubstrate uniformity and intersubstrate repeatability for SERS detection by using the internal standard (relative standard deviation = 10.47%), and were able to detect both charged and neutral molecules (crystal violet and triphenylphosphine) at a concentration of 10-9 M. Importantly, cells can be directly cultured on glass wafers in the 96-well plate, enabling real time monitoring of the secretes and metabolism change in response to external stimulation. We found that the release of nucleic acids, amino acids and lipids by MDA-MB-231 cells significantly increased under hypoxic conditions. Overall, our approach enables fast and large-scale production of Au@CN@Au NPs-coated glass wafers as SERS substrates, which are homogeneous and highly sensitive for monitoring trace changes of biomolecules.
Sujet(s)
Verre , Or , Nanoparticules métalliques , Analyse spectrale Raman , Or/composition chimique , Analyse spectrale Raman/méthodes , Nanoparticules métalliques/composition chimique , Humains , Verre/composition chimique , Lignée cellulaire tumoraleRÉSUMÉ
Sodium alginate (SA) has gained widespread acclaim as a carrier medium for three-dimensional (3D) bioprinting of cells and a diverse array of bioactive substances, attributed to its remarkable biocompatibility and affordability. The conventional approach for fabricating alginate-based tissue engineering constructs entails a post-treatment phase employing a calcium ion solution. However, this method proves ineffectual in addressing the predicament of low precision during the 3D printing procedure and is unable to prevent issues such as non-uniform alginate gelation and substantial distortions. In this study, we introduced borate bioactive glass (BBG) into the SA matrix, capitalizing on the calcium ions released from the degradation of BBG to incite the cross-linking reaction within SA, resulting in the formation of BBG-SA hydrogels. Building upon this fundamental concept, it unveiled that BBG-SA hydrogels greatly enhance the precision of SA in extrusion-based 3D printing and significantly reduce volumetric contraction shrinkage post-printing, while also displaying certain adhesive properties and electrical conductivity. Furthermore, in vitro cellular experiments have unequivocally established the excellent biocompatibility of BBG-SA hydrogel and its capacity to actively stimulate osteogenic differentiation. Consequently, BBG-SA hydrogel emerges as a promising platform for 3D bioprinting, laying the foundation for the development of flexible, biocompatible electronic devices.
Sujet(s)
Alginates , Matériaux biocompatibles , Bio-impression , Borates , Calcium , Verre , Hydrogels , Impression tridimensionnelle , Alginates/composition chimique , Alginates/pharmacologie , Bio-impression/méthodes , Borates/composition chimique , Matériaux biocompatibles/composition chimique , Matériaux biocompatibles/pharmacologie , Calcium/composition chimique , Hydrogels/composition chimique , Verre/composition chimique , Ingénierie tissulaire/méthodes , Structures d'échafaudage tissulaires/composition chimique , Humains , Différenciation cellulaire/effets des médicaments et des substances chimiques , Ostéogenèse/effets des médicaments et des substances chimiquesRÉSUMÉ
Fabrication of porous tissue-engineering scaffolds from bioactive glasses (BAG) is complicated by the tendency of BAG compositions to crystallize in thermal treatments during scaffold manufacture. Here, experimental biocompatible glass S59 (SiO2 59.7 wt%, Na2O 25.5 wt%, CaO 11.0 wt%, P2O5 2.5 wt%, B2O3 1.3 wt%), known to be resistant to crystallization, was used in sintering of glass granules (300-500 µm) into porous scaffolds. The dissolution behavior of the scaffolds was then studied in vivo in rabbit femurs and under continuous flow conditions in vitro (14 days in vitro/56 days in vivo). The scaffolds were osteoconductive in vivo, as bone could grow into the scaffold structure. Still, the scaffolds could not induce sufficiently rapid bone ingrowth to replace the strength lost due to dissolution. The scaffolds lost their structure and strength as the scaffold necks dissolved. In vitro, S59 dissolved congruently throughout the 14-day experiments, resulting in only a slight reaction layer formation. Manufacturing BAG scaffolds from S59 that retain their amorphous structure was thus possible. The relatively rapid and stable dissolution of the scaffold implies that the glass S59 may have the potential to be used in composite implants providing initial strength and stable, predictable release of ions over longer exposure times.
Sujet(s)
Matériaux biocompatibles , Verre , Test de matériaux , Ingénierie tissulaire , Structures d'échafaudage tissulaires , Animaux , Lapins , Structures d'échafaudage tissulaires/composition chimique , Verre/composition chimique , Matériaux biocompatibles/composition chimique , Porosité , Ingénierie tissulaire/méthodes , Fémur , Solubilité , Substituts osseux/composition chimique , Régénération osseuseRÉSUMÉ
Bacteria are often found in environments where space is limited, and they attach themselves to surfaces. One common form of movement on these surfaces is bacterial twitching motility, which is powered by the extension and retraction of type IV pili. Although twitching motility in unrestricted conditions has been extensively studied, the effects of spatial confinement on this behaviour are not well understood. In this study, we explored the diffusive properties of individual twitching Pseudomonas aeruginosa cells in spatially confined conditions. We achieved this by placing the bacteria between layers of agarose and glass, and then tracking the long-term twitching motility of individual cells. Interestingly, we found that while confinement reduced the immediate speed of twitching, it paradoxically increased diffusion. Through a combination of mechanical and geometrical analysis, as well as numerical simulations, we showed that this increase in diffusion could be attributed to mechanical factors. The constraint imposed by the agarose altered the diffusion pattern of the bacteria from normal to superdiffusion. These findings provide valuable insights into the motile behaviour of bacteria in confined environments.
Sujet(s)
Fimbriae bactériens , Pseudomonas aeruginosa , Pseudomonas aeruginosa/physiologie , Fimbriae bactériens/métabolisme , Fimbriae bactériens/physiologie , Mouvement , Agarose , Diffusion , VerreRÉSUMÉ
45S5 Bioglass (BG) is composed of a glass network with silicate based on the component and can be doped with various therapeutic ions for the enhancement of hard tissue therapy. Nanoceria (CeO2) has been shown to indicate redox reaction and enhance the biological response. However, few studies focus on the proportion of CeO2-doped and its effect on the cellular bioactivity of CeO2-doped BG (CBG). In this study, we synthesized the CBG series with increasing amounts of doping CeO2 ranging (1 to 12) wt.%. The synthesized CBG series examined the characterization, mineralization capacity, and cellular activity against BG. Our results showed that the CBG series exhibited a glass structure and indicated the redox states between Ce3+ and Ce4+, thus they showed the antioxidant activity by characterization of Ce. The CBG series had a stable glass network structure similar to BG, which showed the preservation of bioactivity by exhibiting mineralization on the surface. In terms of biological response, although the CBG series showed the proliferative activity of pre-osteoblastic cells similar to BG, the CBG series augmented not only the alkaline phosphatase activity but also the osteogenic marker in the mRNA level. As stimulated the osteogenic activity, the CBG series improved the biomineralization. In conclusion, the CBG series might have a potential application for hard tissue therapeutic purposes.
Sujet(s)
Céramiques , Cérium , Verre , Oxydoréduction , Cérium/composition chimique , Cérium/pharmacologie , Oxydoréduction/effets des médicaments et des substances chimiques , Verre/composition chimique , Souris , Céramiques/composition chimique , Céramiques/pharmacologie , Animaux , Ostéoblastes/effets des médicaments et des substances chimiques , Ostéoblastes/métabolisme , Prolifération cellulaire/effets des médicaments et des substances chimiques , Ostéogenèse/effets des médicaments et des substances chimiques , Lignée cellulaire , Matériaux biocompatibles/composition chimique , Matériaux biocompatibles/pharmacologie , Phosphatase alcaline/métabolismeRÉSUMÉ
Rapid expansion in urban areas has engendered a superfluity of municipal solid waste (MSW) stemming from contemporary civilization, encompassing commercial sectors and human undertakings. Kerbside waste, a type of MSW, has the potential for recycling and reuse at the end of its first life cycle, but is often limited to a linear cycle. This study aimed to assess the life cycle costs of different separation and recycling methods for handling kerbside waste. A new life cycle cost model, drawing from the circular economy's value retention process (VRP) model, has been created and applied to assess the continuous recycling of kerbside glass. The study investigates two key separation techniques, kerbside recycling mixed bin recycling (KRMB) kerbside glass recycling separate bin (KGRSB) and analyses their impact on the life cycle cost of the recycling process. Additionally, the research explores two approaches of recycling and downcycling: closed-loop recycling, which pertains to the recycling of glass containers, and open-looped recycling, which involves the use of recycled glass in asphalt. The results showed when use annually collected waste as the functional unit, the KRMB model incurred lower costs compared to the KGRSB model due to its lower production output. However, when evaluated over a 1-ton production of glass container and asphalt, the KGRSB method demonstrated superior cost performance with a 40-50% reduction compared to the KRMB method. The open-loop recycling method (asphalt) incurred a higher cost compared to the closed-loop recycling method due to its larger production volume over a 21-year period.
Sujet(s)
Recyclage , Déchets solides , Gestion des déchets , Recyclage/méthodes , Recyclage/économie , Déchets solides/analyse , Gestion des déchets/méthodes , Gestion des déchets/économie , Verre , Élimination des déchets/méthodes , Élimination des déchets/économie , HydrocarburesRÉSUMÉ
Ternary alkali-activated binder was prepared by blast furnace slag (GGBS), recycled powder (RP) and waste glass powder (WGP) using simplex centroid design method. By measuring the fluidity, setting time, drying shrinkage and mechanical property of specimen, the complementary effect of GGBS, RP and WGP was discussed. The reaction mechanism and microstructure were explored by X-ray diffraction and scanning electron microscopy. The results reveal that the addition of RP could significantly reduce the fluidity and setting time of paste, while WGP can obviously improve the rheological property and play a retarding role. The workability of paste can be effectively regulated by mixing RP and WGP together. Whether added alone or in combination, RP and WGP can effectively improve the shrinkage performance. In the ternary system, GGBS can be rapidly activated and form a skeleton structure. The fine RP particles can play a good role in filling the structure, and the pozzolanic reaction of WGP gradually occurs, which makes the microstructure more compact. The incorporation of GGBS, RP and WGP can promote the growth of hydration products, improve the density of microstructure, and form a certain complementary effect.
Sujet(s)
Alcalis , Verre , Poudres , Recyclage , Verre/composition chimique , Alcalis/composition chimique , Diffraction des rayons X , Microscopie électronique à balayageRÉSUMÉ
Acrylic resins are widely used as the main components in removable orthodontic appliances. However, poor oral hygiene and maintenance of orthodontic appliances provide a suitable environment for the growth of pathogenic microorganisms. In this study, strontium-modified phosphate-based glass (Sr-PBG) was added to orthodontic acrylic resin at 0% (control), 3.75%, 7.5%, and 15% by weight to evaluate the surface and physicochemical properties of the novel material and its in vitro antifungal effect against Candida albicans (C. albicans). Surface microhardness and contact angle did not vary between the control and 3.75% Sr-PBG groups (p > 0.05), and the flexural strength was lower in the experimental groups than in the control group (p < 0.05), but no difference was found with Sr-PBG content (p > 0.05). All experimental groups showed an antifungal effect at 24 and 48 h compared to that in the control group (p < 0.05). This study demonstrated that 3.75% Sr-PBG exhibits antifungal effects against C. albicans along with suitable physicochemical properties, which may help to minimize the risk of adverse effects associated with harmful microbial living on removable orthodontic appliances and promote the use of various materials.
Sujet(s)
Résines acryliques , Antifongiques , Candida albicans , Verre , Test de matériaux , Phosphates , Strontium , Propriétés de surface , Candida albicans/effets des médicaments et des substances chimiques , Résines acryliques/composition chimique , Strontium/pharmacologie , Strontium/composition chimique , Antifongiques/pharmacologie , Verre/composition chimique , Phosphates/pharmacologie , Polymérisation , Dureté , Résistance à la flexion , Humains , Techniques in vitroRÉSUMÉ
Holmium (Ho3+)-doped boro-bismuth-germanate glasses having the chemical composition (30-x)B2O3 + 20GeO2 + 20Bi2O3 + 20Na2O + 10Y2O3 + xHo2O3, where x = 0.1, 0.5, 1.0, and 2.0 mol% were prepared by melt-quenching technique. The prepared glasses were examined for thermal, optical, vibrational, and photoluminescent properties. The prepared glasses were found to be thermally very stable. The optical bandgap and Urbach energies of 0.1 mol% Ho2O3-doped boro-bismuth-germanate glass were calculated to be 3.3 eV and 377 MeV, respectively, using the absorption spectrum. The Judd-Ofelt analysis was performed on the 0.1 mol% Ho2O3-doped glass and compared the obtained parameters with literature. The branching ratio (ß) and emission cross-section (σem) of the green band were determined to be 0.7 and 0.24 × 10-20 cm2, respectively. Under 450 nm excitation, a strong green emission around 550 nm was observed and assigned to the (5S2 + 5F4) â 5I8 (Ho3+) transition. Upon an increase of Ho2O3 content from 0.1 to 2.0 mol%, the intensities of all observed emission bands as well as decay time of the (5S2 + 5F4) â 5I8 transition have been decreased gradually. The reasons behind the decrease in emission intensity and decay time were discussed. The strong green emission suggests that these glasses may be a better option for display devices and green emission applications.
Sujet(s)
Bismuth , Germanium , Verre , Holmium , Luminescence , Holmium/composition chimique , Verre/composition chimique , Germanium/composition chimique , Bismuth/composition chimique , Vibration , Mesures de luminescence , Phénomènes optiquesRÉSUMÉ
The aim of this research is to investigate novel compositions of oxyfluoride glasses doped with Neodymium (Nd3+) rare earth ions in the visible spectrum. This area has not been extensively studied in the existing literature, so it is vital to understand the favorable photoluminescence characteristics within this part of the electromagnetic spectrum. Therefore, we synthesized and characterized SiO2-PbO-PbF2 (SPF) doped with 1% neodymium (Nd3+) ions glasses. Spectroscopic analyses, based on Judd-Ofelt theory, were conducted on absorption spectra. These analyses enabled to determine absorption cross-sections, transition probabilities, and Judd-Ofelt intensity parameters Ω2, Ω4, and Ω6 for the different transition. Additionally, we calculated various radiative properties, such as branching ratios, integrated cross-sections, radiative lifetimes, emission cross-section, optical gain, and the multicolor behavior (chromaticity coordinates, CIE diagram) under different excitation wavelengths. The results suggest promising prospects for using these oxyfluoride silicate glasses doped with Nd3+ as a fluorophore, potentially for lasing materials around 630-nm emission and in other photonic applications.