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1.
ACS Appl Mater Interfaces ; 16(36): 46947-46963, 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39225271

RESUMO

Biomedical-device-associated infection (BAI) is undoubtedly a major concern and a serious challenge in modern medicine. Therefore, the development of biomedical materials that are capable of resisting or killing bacteria is of great importance. In this work, a croconaine-functionalized polymer with antifouling and near-infrared (NIR) photothermal bactericidal properties was prepared and facilely modified on polypropylene (PP) to combat medical device infections. Croconaine dye is elaborately modified as a "living" initiator, termed CR-4EBiB, for preparing amphiphilic block polymers by atom transfer radical polymerization (ATRP). In the formed polymer coating, the hydrophobic block can strongly adhere to the surface of the PP substrate, whereas the hydrophilic block is located on the outer layer by solvent-induced resistance to bacterial adhesion. Under the irradiation of an NIR laser (808 nm), the croconaine dye in the coating achieved maximum conversion of light to heat to effectively kill E. coli, S. aureus, and methicillin-resistant Staphylococcus aureus (MRSA). This work provides a facile and promising strategy for the development of implantable antibacterial biomedical materials.


Assuntos
Antibacterianos , Escherichia coli , Raios Infravermelhos , Staphylococcus aureus Resistente à Meticilina , Polipropilenos , Polipropilenos/química , Polipropilenos/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Antibacterianos/síntese química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Propriedades de Superfície , Polímeros/química , Polímeros/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Incrustação Biológica/prevenção & controle
2.
Sci Rep ; 14(1): 19284, 2024 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-39164338

RESUMO

Microplastics have the capacity to accumulate in soil due to their high resistance to degradation, consequently altering soil properties and influencing plant growth. This study focused on assessing the impact of various types and doses of microplastics on beech seedling growth. In our experiment, we used polypropylene and styrene granules with diameter of 4.0 mm in quantities of 2.5% and 7%. The hypothesis was that microplastics significantly affect seedlings' nutritional status and growth characteristics. The research analysed seedlings' nutrition, root morphological features, above-ground growth, and enzymatic activity in the substrate. Results confirmed the importance of microplastics in shaping the nutritional status of young beech trees. Microplastic type significantly impacted N/P and Ca/Mg stoichiometry, while microplastic quantity influenced Ca/Al and Ca+K+Mg/Al stoichiometry. Notably, only in the case of root diameter were significantly thicker roots noted in the control variant, whereas microplastics played a role in shaping the leaves' characteristics of the species studied. The leaf area was significantly larger in the control variant compared to the variant with polypropylene in the amount of 2.5% and styrene in the amount of 7%. Additionally, the study indicates a significant impact of microplastics on enzyme activity. In the case of CB and SP, the activity was twice as high in the control variant compared to the variants with microplastics. In the case of BG, the activity in the control variant was higher in relation to the variants used in the experiment. Research on the impact of microplastics on the growth of beech seedlings is crucial for enhancing our understanding of the effects of environmental pollution on forest ecosystems. Such studies are integral in shaping forestry management practices and fostering a broader public understanding of the ecological implications of plastic pollution.


Assuntos
Fagus , Microplásticos , Plântula , Fagus/efeitos dos fármacos , Fagus/crescimento & desenvolvimento , Fagus/metabolismo , Plântula/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/metabolismo , Microplásticos/toxicidade , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Poluentes do Solo/toxicidade , Solo/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Polipropilenos , Estireno/metabolismo
3.
Environ Pollut ; 359: 124751, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39151783

RESUMO

The impacts of microplastics on soil ecological functions such as carbon recycling and soil structure maintenance have been extensively focused. However, the mechanisms underlying the impacts of microplastics on soil carbon transformation and soil microbial community at soil aggregate scale have not been clarified yet. In this work, the effects and action mechanisms of traditional microplastic polypropylene (PP) and degradable microplastic polylactic acid (PLA) on carbon transformation in three sizes of soil aggregates were investigated. The results showed that both PP and PLA promoted CO2 emission, and the effect depended on the type and content of microplastics, and the size of soil aggregates. Changes in soil carbon stocks were mainly driven by changes in organic carbon associated with macroaggregates. For macroaggregates, PP microplastics decreased soil organic carbon (SOC) as well as dissolved organic carbon (DOC). These changes were reversed in microaggregates and silt and clay. Interestingly, PLA increased the SOC, DOC and CO2 emissions in bulk soil and all three aggregates with a dose-effect response. These changes were associated with soil microbes, functional genes and enzymes associated with the degradation of labile and recalcitrant carbon fractions. Furthermore, PP and PLA reduced bacterial community diversities and shifted bacterial community structures in both the three aggregates and in bulk soil. Alterations of functional genes induced by microplastics were the key driving factors of their impacts on carbon transformation in soil aggregates. This research opened up a new insight into the mechanisms underlying the impacts of microplastics on soil carbon transformation, and helped us make rational assessments of the risks and the disturbances of microplastics on soil carbon cycling.


Assuntos
Carbono , Microplásticos , Microbiologia do Solo , Poluentes do Solo , Solo , Solo/química , Biodegradação Ambiental , Poliésteres/química , Polipropilenos/química
5.
Water Res ; 263: 122177, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39111211

RESUMO

For the resource recovery of biomass waste, it is a challenge to simultaneously remove micro-/nano-plastics pollution but preserve organic resources. Wet oxidation is a promising technology for valorization of organic wastes through thermal hydrolysis and oxidation. This might in turn result in the degradation of microplastics in the presence of oxygen and high temperatures. Based on this hypothesis, this study quantified both microplastics and nanoplastics in an industrial-scale wet oxidation reactor from a full-size coverage perspective. Wet oxidation significantly reduced the size and mass of individual microplastics, and decreased total mass concentration of microplastics and nanoplastics by 94.8 % to 98.6 %. This technology also reduced the micro- and nanoplastic shapes and polymer types, resulting in a complete removal of fibers, clusters, polypropylene (PP) and poly(methyl methacrylate) (PMMA). The present study confirms that wet oxidation technology is effective in removing microplastics and nanoplastics while recovering organic waste.


Assuntos
Microplásticos , Oxirredução , Poluentes Químicos da Água/química , Polipropilenos/química , Plásticos/química , Polimetil Metacrilato/química
6.
Environ Sci Technol ; 58(35): 15711-15721, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39172764

RESUMO

Recent research has shown that microplastics are widespread in the atmosphere. However, we know little about their ability to nucleate ice and their impact on ice formation in clouds. Ice nucleation by microplastics could also limit their long-range transport and global distribution. The present study explores the heterogeneous ice-nucleating ability of seven microplastic samples in immersion freezing mode. Two polypropylene samples and one polyethylene terephthalate sample froze heterogeneously with median freezing temperatures of -20.9, -23.2, and -21.9 °C, respectively. The number of ice nucleation sites per surface area, ns(T), ranged from 10-1 to 104 cm-2 in a temperature interval of -15 to -25 °C, which is comparable to that of volcanic ash and fungal spores. After exposure to ozone or a combination of UV light and ozone, simulating atmospheric aging, the ice nucleation activity decreased in some cases and remained unchanged in others. Our freezing data suggest that microplastics may promote ice formation in cloud droplets. In addition, based on a comparison of our freezing results and previous simulations using a global transport model, ice nucleation by microplastics will impact their long-range transport to faraway locations and global distribution.


Assuntos
Atmosfera , Gelo , Microplásticos , Atmosfera/química , Ozônio/química , Congelamento , Raios Ultravioleta , Poluentes Atmosféricos/química , Polietilenotereftalatos/química , Polipropilenos/química
7.
Environ Sci Pollut Res Int ; 31(39): 52181-52197, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39141264

RESUMO

Industrial solid waste (mine tailings) management has emerged as the key universal ecological challenge as a result of the unceasing creation of rising waste by-products. Employing tailings makes mine fill production economical and assists resolve disposal problems. Foamed cement-based tailings backfill (FCTB) is a mine fill consisting of tailing, cement, water, and foaming agents. It provides certain advantages such as lightweight, good fluidity, and thermal insulation yet is relatively weak in strength. Additionally, FCTB's strength properties can be intensely improved by adding fibers. A total of three diverse fibers: polypropylene (PP), glass (G), and basalt (B) as well as dodecyltrimethylammonium bromide (DTAB) as a foaming agent were used to prepare fiber-reinforced foamed cementitious tailings backfill (FR-FCTB). The mechanical properties, energy evolution, ductility, and microstructure of FR-FCTB were elaborately investigated by uniaxial compression tests (UCS) and SEM. Laboratory findings demonstrate the reinforcing effect of three fibers on FCTB specimens: glass > polypropylene > basalt. FR-FCTB showed the best strength features as a fiber content of 0.3% was adopted in FCTB. At this time, the UCS performance of glass fiber-reinforced FCTBs was 0.85 MPa increased by 18.1%. The addition of fibers can increase the fill's energy storage limit, slow down the discharge of elastic strain energy within the backfill, and enhance the fill's ductility and toughness. The ductility factor evaluates the degree of deterioration of filling in terms of post-peak drop, with all FR-FCTB values being greater than CTB. FR-FCTB's chief hydration product is the C-S-H gel. Fiber's bridging effect significantly rallies crack extension and thus fill's strength features. Lastly, the study's main results are instructive for the industrial application of FR-FCTB used in metallic mines.


Assuntos
Materiais de Construção , Polipropilenos/química , Mineração
8.
Int J Biol Macromol ; 277(Pt 3): 134316, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39094859

RESUMO

Due to dwindling petroleum resources and the need for environmental protection, the development of bio-based flame retardants has received much attention. In order to explore the feasibility of fully biomass polyelectrolyte complexes (PEC) for polyolefin flame retardant applications, chitosan (CS), sodium alginate (SA), and sodium phytate (SP) were used to prepare CS-based fully biomass PEC intercalated montmorillonite (MMT) hybrid biomaterials (SA-CS@MMT and SP-CS@MMT). The effects of two hybrid biomaterials on the fire safety and mechanical properties of intumescent flame-retardant polypropylene (PP) composites were compared. The SP-CS@MMT showed the best flame retardancy and toughening effect at the same addition amount. After adding 5 wt% SP-CS@MMT, the limiting oxygen index (LOI) value of PP5 reached 30.9 %, and the peak heat release rate (pHRR) decreased from 1348 kW/m2 to 163 kW/m2. In addition, the hydrogen bonding between polyelectrolyte complexes significantly improved the mechanical properties of PP composites. Compared with PP2, the tensile strength of PP5 increased by 59 %. This study provided an efficient and eco-friendly strategy for the large-scale production of renewable biomaterials with good thermal stability and expanded the application of macromolecular biomaterials in the field of fire safety.


Assuntos
Bentonita , Quitosana , Retardadores de Chama , Polieletrólitos , Polipropilenos , Quitosana/química , Bentonita/química , Polipropilenos/química , Polieletrólitos/química , Resistência à Tração , Química Verde/métodos , Materiais Biocompatíveis/química , Fenômenos Mecânicos
9.
Sci Total Environ ; 951: 175690, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-39173748

RESUMO

Microplastics and antibiotics are receiving increasing attention as two emerging pollutants in the aquatic ecosystem. The absorption of antibiotics by microplastics can potentially intensify their impact on marine organisms and human health. However, the detailed mechanisms underlying this interaction remain to be elucidated. Through molecular dynamics (MD) simulations and density functional theory (DFT) calculations, this study investigated the adsorption of cefradine (CED) onto three typical microplastics (MPs)-polyethylene (PE), polypropylene (PP), and polyamide (PA). The results of the molecular dynamics simulations showed that the interaction energy between CED and microplastics followed the order of PA-CED > PP-CED > PE-CED, indicating that PA microplastics had the highest adsorption capacity for CED antibiotics. The total energy contribution of the microplastics-cefradine (MPs-CED) systems suggested that the van der Waals and electrostatic interactions were the two primary mechanisms for the adsorption of CED by these three microplastics. In DFT calculations, the adsorption of CED on PA was found to be significantly influenced by both electrostatic and van der Waals effects, while the main driving force in the adsorption of PE and PP is van der Waals effect. In addition, IGMH analysis and AIM topological analysis confirmed that the adsorption of CED on PA relied heavily on the synergistic effect of hydrogen bonding and the van der Waals effect. The findings of this study validate the results obtained from molecular dynamics simulations, laying a foundation for a comprehensive exploration of the interaction mechanisms between microplastics and organic pollutants by integrating MD simulations and DFT calculations.


Assuntos
Cefradina , Teoria da Densidade Funcional , Microplásticos , Simulação de Dinâmica Molecular , Poluentes Químicos da Água , Adsorção , Poluentes Químicos da Água/química , Cefradina/química , Modelos Químicos , Antibacterianos/química , Polipropilenos/química , Polietileno/química
10.
Bioresour Technol ; 411: 131358, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39191296

RESUMO

As an emerging pollutant, microplastics (MPs) have attracted increasing attention worldwide. The effects of polypropylene (PP) MPs on digestion performance, behaviors of dominant microbial communities, antibiotic resistance genes (ARGs) and mobile genetic elements in microbial anaerobic digesters were investigated. The results showed that the addition of PP-MPs to digesters led to an increase in methane production of 10.8% when 300 particles/g TSS of PP-MPs was introduced compared with that in digester not treated with PP-MPs. This increase was attributed to the enrichment of acetogens such as Syntrophobacter (42.0%), Syntrophorhabdus (27.0%), and Syntrophomonas (10.6%), and methanogens including Methanobacterium and Methanosaeta. tetX was highly enriched due to PP-MP exposure, whereas parC exhibited the greatest increase (35.5% - 222.7%). Horizontal gene transfer via ISCR1 and intI1 genes might play an important role in the spread of ARGs. Overall, these findings provide comprehensive insight into the ecological dynamics of PP-MPs during microbial anaerobic digestion.


Assuntos
Resistência Microbiana a Medicamentos , Microplásticos , Polipropilenos , Anaerobiose , Resistência Microbiana a Medicamentos/genética , Reatores Biológicos , Metano/metabolismo , Biodegradação Ambiental , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/metabolismo
11.
J Plast Reconstr Aesthet Surg ; 97: 89-114, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39151289

RESUMO

BACKGROUND: The use of lower-pole sling products has made immediate breast reconstruction a feasible option in women undergoing skin-nipple sparing and skin-reducing mastectomies. To date, available data on the comparative efficacy of biological and synthetic meshes regarding postoperative complications are scattered and limited. METHODS: A systematic literature search was performed to screen three different databases (PubMed, Web of Sciences, and Embase) using the following keywords: "breast reconstruction" AND "TiLOOP®" OR "Titanium-Coated Polypropylene Mesh" OR "TCPM". The perioperative and demographic characteristics of patients, complications profiles, and patient-reported outcomes were considered. RESULTS: We initially identified 234 articles, of which only 41, including 3923 patients and 5042 reconstructed breasts, fully satisfied the inclusion criteria. CONCLUSION: TiLOOP® Bra could be considered a safe and aesthetically valid alternative to Acellular Dermal Matrices (ADMs) in non-smokers patients undergoing skin-nipple sparing and skin-reducing mastectomies and immediate reconstruction. In such populations, complications are more likely to develop in patients with extreme body mass index values. The incidence of seroma with TiLOOP® Bra is comparable to that of ADMs as it is the beneficial effect in radiated patients, where TiLOOP® Bra seems superior to implant alone reconstruction. It has a good bio-integration with host tissues and resistance to infections in patients with a weakened immune system as a consequence of oncologic perioperative treatments.


Assuntos
Mamoplastia , Complicações Pós-Operatórias , Telas Cirúrgicas , Humanos , Feminino , Mamoplastia/métodos , Complicações Pós-Operatórias/prevenção & controle , Neoplasias da Mama/cirurgia , Polipropilenos , Titânio , Mastectomia/métodos
12.
Acta Biomater ; 186: 185-200, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39103136

RESUMO

Thrombosis and plasma leakage are two of the most frequent dysfunctions of polypropylene (PP) hollow fiber membrane (PPM) used in extracorporeal membrane oxygenation (ECMO) therapy. In this study, a superhydrophilic endothelial membrane mimetic coating (SEMMC) was constructed on polydopamine-polyethyleneimine pre-coated surfaces of the PPM oxygenator and its ECMO circuit to explore safer and more sustainable ECMO strategy. The SEMMC is fabricated by multi-point anchoring of a phosphorylcholine and carboxyl side chained copolymer (PMPCC) and grafting of heparin (Hep) to form PMPCC-Hep interface, which endows the membrane superior hemocompatibility and anticoagulation performances. Furthermore, the modified PPM reduces protein adsorption amount to less than 30 ng/cm2. More significantly, the PMPCC-Hep coated ECMO system extends the anti-leakage and non-clotting oxygenation period to more than 15 h in anticoagulant-free animal extracorporeal circulation, much better than the bare and conventional Hep coated ECMO systems with severe clots and plasma leakage in 4 h and 8 h, respectively. This SEMMC strategy of grafting bioactive heparin onto bioinert zwitterionic copolymer interface has great potential in developing safer and longer anticoagulant-free ECMO systems. STATEMENT OF SIGNIFICANCE: A superhydrophilic endothelial membrane mimetic coating was constructed on surfaces of polypropylene hollow fiber membrane (PPM) oxygenator and its ECMO circuit by multi-point anchoring of a phosphorylcholine and carboxyl side chain copolymer (PMPCC) and grafting of heparin (Hep). The strong antifouling nature of the PMPCC-Hep coating resists the adsorption of plasma bio-molecules, resulting in enhanced hemocompatibility and anti-leakage ability. The grafted heparin on the zwitterionic PMPCC interface exhibits superior anticoagulation property. More significantly, the PMPCC-Hep coating achieves an extracorporeal circulation in a pig model for at least 15 h without any systemic anticoagulant. This endothelial membrane mimetic anticoagulation strategy shows great potential for the development of safer and longer anticoagulant-free ECMO systems.


Assuntos
Materiais Revestidos Biocompatíveis , Oxigenação por Membrana Extracorpórea , Animais , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Heparina/química , Heparina/farmacologia , Humanos , Polipropilenos/química , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Fibrinolíticos/farmacologia , Fibrinolíticos/química , Membranas Artificiais , Adsorção , Trombose/prevenção & controle , Fosforilcolina/química , Fosforilcolina/análogos & derivados , Polímeros/química
13.
J Hazard Mater ; 478: 135443, 2024 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-39128156

RESUMO

Microplastics (MPs) are widespread in agroecosystems and profoundly impact soil microbiome and nutrient cycling. However, the effects of MPs on soil autotrophic ammonium oxidization processes, including nitrification, complete ammonium oxidation (comammox), anaerobic ammonium oxidation (anammox), and anaerobic ammonium oxidation coupled to iron reduction (Feammox), remain unclear. These processes are the rate-limiting steps of nitrogen cycling in agroecosystems. Here, our work unveiled that exposures of polyethylene (PE), polypropylene (PP), polylactic acid (PLA), and polybutylene adipate terephthalate (PBAT) MPs significantly modulated ammonium oxidization pathways with distinct type- and dose-dependent effects. Nitrification remained the main contributor (56.4-70.7 %) to soil ammonium removal, followed by comammox (11.7-25.6 %), anammox (5.0-20.2 %) and Feammox (3.3-11.6 %). Compared with conventional nonbiodegradable MPs (i.e., PE and PP), biodegradable MPs (i.e., PLA and PBAT) exhibited more pronounced impacts on soil nutrient conditions and functional microbes, which collectively induced alterations in soil ammonium oxidation. Interestingly, low-dose PLA and PBAT remarkably enhanced the roles of anammox and Feammox in soil ammonium removal, contributing to the mitigation of soil acidification in agroecosystems. This study highlights the diverse responses of ammonium oxidization pathways to MPs, further deepening our understanding of how MPs affect biogeochemical cycling and enriching strategies for agricultural managements amid increasing MPs pollution.


Assuntos
Compostos de Amônio , Microplásticos , Nitrificação , Oxirredução , Poluentes do Solo , Poluentes do Solo/metabolismo , Compostos de Amônio/metabolismo , Microplásticos/metabolismo , Microbiologia do Solo , Poliésteres/metabolismo , Solo/química , Processos Autotróficos , Ferro/metabolismo , Ferro/química , Polipropilenos/metabolismo , Anaerobiose
14.
J Hazard Mater ; 478: 135475, 2024 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-39146588

RESUMO

This study aims to deepen knowledge of the biodegradation of plastics, focusing on polypropylene (PP) fabric from surgical masks and polystyrene (PS) by larvae of Zophobas atratus as well as of specialized bacterial consortia from their gut, which were obtained in different enrichment conditions (aerobic, anaerobic, presence or absence of combined nitrogen). Plastics ingested by larvae obtained in Spain did not show any signs of oxidation but only limited depolymerization, preferably from the lowest molecular weight chains. Gut microbiota composition changed as an effect of plastic feeding. Such differences were more evident in bacterial enrichment cultures, where the polymer type influenced the composition more than by culture conditions, with an increase in the presence of nitrogen-fixers in anaerobic conditions. PS and PP degradation by different enrichment cultures was confirmed under aerobic and anaerobic conditions by respirometry tests, with anaerobic conditions favouring a more active plastic degradation. In addition, exposure to selected bacterial consortia in aerobiosis induced limited surface oxidation of PS. This possibly indicates that different biochemical routes are being utilized in the anaerobic gut and in aerobic conditions to degrade the polymer.


Assuntos
Biodegradação Ambiental , Larva , Polipropilenos , Poliestirenos , Poliestirenos/química , Poliestirenos/metabolismo , Animais , Polipropilenos/química , Polipropilenos/metabolismo , Larva/metabolismo , Anaerobiose , Microbioma Gastrointestinal , Bactérias/metabolismo , Consórcios Microbianos , Aerobiose
15.
J Hazard Mater ; 478: 135469, 2024 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-39173375

RESUMO

Increasing evidence highlights the negative effects of microplastics (MPs) on crops and bio-based plastics offer an alternative to conventional plastics. However, there is limited knowledge on the impacts and mechanisms of bio-based MPs on crop physiology. In this study, bio-based polylactic acid (PLA) and petroleum-based MPs [polyamide (PA) and polypropylene (PP)] were added to hydroponic cultures planted with rice (Oryza sativa L.) seedlings to assess their toxicity. Compared to PA and PP MPs, PLA MPs experienced greater aging after 28 days of exposure, and their surfaces were loaded with more rod-shaped microorganisms with potential plastic degradation ability, such as Proteobacteria and Bacteroidota, which competed with rice seedlings for carbon and nitrogen sources for self-multiplication, thus altering the carbon fixation and nitrogen cycling processes during rice seedling growth. Down-regulation of amino acid and lipid metabolisms in the PLA treatment inhibited the normal synthesis of chlorophyll in rice seedling leaves. Consequently, decreases in the biomass and height of rice seedling roots and shoots were observed in the PLA MP treatment. This study provides evidence that bio-based MPs may have a more severe impact on crop growth than petroleum-based MPs.


Assuntos
Biofilmes , Microplásticos , Oryza , Petróleo , Poliésteres , Plântula , Oryza/crescimento & desenvolvimento , Oryza/efeitos dos fármacos , Oryza/metabolismo , Poliésteres/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Microplásticos/toxicidade , Petróleo/toxicidade , Clorofila/metabolismo , Polipropilenos , Aminoácidos/metabolismo
16.
Part Fibre Toxicol ; 21(1): 29, 2024 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-39107780

RESUMO

BACKGROUND: Microplastics have been detected in the atmosphere as well as in the ocean, and there is concern about their biological effects in the lungs. We conducted a short-term inhalation exposure and intratracheal instillation using rats to evaluate lung disorders related to microplastics. We conducted an inhalation exposure of polypropylene fine powder at a low concentration of 2 mg/m3 and a high concentration of 10 mg/m3 on 8-week-old male Fischer 344 rats for 6 h a day, 5 days a week for 4 weeks. We also conducted an intratracheal instillation of polypropylene at a low dose of 0.2 mg/rat and a high dose of 1.0 mg/rat on 12-week-old male Fischer 344 rats. Rats were dissected from 3 days to 6 months after both exposures, and bronchoalveolar lavage fluid (BALF) and lung tissue were collected to analyze lung inflammation and lung injury. RESULTS: Both exposures to polypropylene induced a persistent influx of inflammatory cells and expression of CINC-1, CINC-2, and MPO in BALF from 1 month after exposure. Genetic analysis showed a significant increase in inflammation-related factors for up to 6 months. The low concentration in the inhalation exposure of polypropylene also induced mild lung inflammation. CONCLUSION: These findings suggest that inhaled polypropylene, which is a microplastic, induces persistent lung inflammation and has the potential for lung disorder. Exposure to 2 mg/m3 induced inflammatory changes and was thought to be the Lowest Observed Adverse Effect Level (LOAEL) for acute effects of polypropylene. However, considering the concentration of microplastics in a real general environment, the risk of environmental hazards to humans may be low.


Assuntos
Líquido da Lavagem Broncoalveolar , Exposição por Inalação , Pulmão , Microplásticos , Pneumonia , Polipropilenos , Ratos Endogâmicos F344 , Animais , Masculino , Polipropilenos/toxicidade , Microplásticos/toxicidade , Exposição por Inalação/efeitos adversos , Líquido da Lavagem Broncoalveolar/citologia , Líquido da Lavagem Broncoalveolar/imunologia , Líquido da Lavagem Broncoalveolar/química , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/patologia , Pneumonia/induzido quimicamente , Ratos
17.
Ecotoxicol Environ Saf ; 283: 116844, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39128455

RESUMO

Microplastics, as emerging contaminants, pose a serious threat to terrestrial ecosystems, yet their impact on plant communities remains largely unexplored. This study utilized the soil seed bank to establish naturally germinated plant communities and investigated the effects of polyethylene (PE) and polypropylene (PP) on community characteristics. Additionally, the study aimed to elucidate the mechanisms by which variations in soil properties influenced plant community. The results indicated that microplastics led to a significant increase in soil available potassium (AK), likely due to alterations in soil microorganism proliferation. Furthermore, microplastics caused a decrease in soil salinity, total phosphorus (TP), and ammonium nitrogen (AN). Additionally, plant community composition shifted, resulting in reduced stability and niche breadth of dominant species. Microplastics also impacted niche overlap and interspecific associations among dominant species, possibly due to the reduced accessibility of resources for dominant species. Salinity, AK, and TP were identified as major drivers of changes in niche breadth, niche overlap, and community stability, with TP exerting the strongest impact on plant community composition. These findings provide valuable insights for the restoration of plant communities in coastal saline-alkali wetland contaminated by microplastics.


Assuntos
Microplásticos , Fósforo , Plantas , Microbiologia do Solo , Poluentes do Solo , Solo , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Microplásticos/toxicidade , Microplásticos/análise , Plantas/efeitos dos fármacos , Fósforo/análise , Salinidade , Nitrogênio/análise , Polipropilenos , Polietileno , Potássio/análise , Ecossistema , Áreas Alagadas
18.
Waste Manag ; 187: 306-316, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39089146

RESUMO

Plastic waste poses a critical environmental challenge for the world. The proliferation of waste plastic coffee pods exacerbates this issue. Traditional disposal methods such as incineration and landfills are environmentally unfriendly, necessitating the exploration of alternative management strategies. One promising avenue is the pyrolysis in-line reforming process, which converts plastic waste into hydrogen. However, traditional pyrolysis methods are costly due to inefficiencies and heat losses. To address this, for the first time, our study investigates the use of microwave to enhance the pyrolysis process. We explored microwave pyrolysis for polypropylene (PP), high-density polypropylene (HDPE), and waste coffee pods, with the latter primarily comprising polypropylene. Additionally, catalytic ex-situ pyrolysis of coffee pod pyrolysis over a nickel-based catalyst was investigated to convert the evolved gas into hydrogen. The single-stage microwave pyrolysis results revealed the highest gas yield at 500 °C for HDPE, and 41 % and 58 % (by mass) for waste coffee pods and polypropylene at 700 °C, respectively. Polypropylene exhibited the highest gaseous yield, suggesting its readiness for pyrolytic degradation. Waste coffee pods uniquely produced carbon dioxide and carbon monoxide gases because of the oxygen present in their structure. Catalytic reforming of evolved gas from waste coffee pods using a 5 % nickel loaded activated carbon catalyst, yielded 76 % (by volume) hydrogen at 900 °C. These observed results were supported by elemental balance analysis. These findings highlight that two-stage microwave and catalysis assisted pyrolysis could be a promising method for the efficient management of waste coffee pods, particularly for producing clean energy.


Assuntos
Café , Hidrogênio , Micro-Ondas , Polietileno , Polipropilenos , Pirólise , Polipropilenos/química , Hidrogênio/química , Café/química , Catálise , Polietileno/química , Eliminação de Resíduos/métodos
19.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 55(4): 853-860, 2024 Jul 20.
Artigo em Chinês | MEDLINE | ID: mdl-39170003

RESUMO

Objective: This study aims to develop a medical patch surface material featuring a microporous polyurethane (PU) membrane and to assess the material's properties and biological performance. The goal is to enhance the clinical applicability of pelvic floor repair patch materials. Methods: PU films with a microporous surface were prepared using PU prepolymer foaming technology. The films were produced by optimizing the PU prepolymer isocyanate index (R value) and the relative humidity (RH) of the foaming environment. The surface morphology of the PU microporous films was observed by scanning electron microscopy, and the chemical properties of the PU microporous films, including hydrophilicity, were analyzed using infrared spectroscopy, Raman spectroscopy, and water contact angle measurements. In vitro evaluations included testing the effects of PU microporous film extracts on the proliferation of L929 mouse fibroblasts and observing the adhesion and morphology of these fibroblasts. Additionally, the effect of the PU microporous films on RAW264.7 mouse macrophages was studied. Immune response and tissue regeneration were assessed in vivo using Sprague Dawley (SD) rats. Results: The PU films exhibited a well-defined and uniform microporous structure when the R value of PU prepolymer=1.5 and the foaming environment RH=70%. The chemical structure of the PU microporous films was not significantly altered compared to the PU films, with a significantly lower water contact angle ([55.7±1.5]° ) compared to PU films ([69.5±1.7]° ) and polypropylene (PP) ([ 104.3±2.5]°), indicating superior hydrophilicity. The extracts from PU microporous films demonstrated good in vitro biocompatibility, promoting the proliferation of L929 mouse fibroblasts. The surface morphology of the PU microporous films facilitated fibroblast adhesion and spreading. The films also inhibited the secretion of tumor necrosis factor-α (TNF-α) and interleukin (IL)-1ß by RAW264.7 macrophages while enhancing IL-10 and IL-4 secretion. Compared to 24 hours, after 72 hours of culture, the expression levels of TNF-α and IL-1ß were reduced in both the PU film and PU microporous film groups and were significantly lower than those in the PP film group (P<0.05), with the most notable decreases observed in the PU microporous film group. IL-10 and IL-4 levels increased significantly in the PU microporous film group, surpassing those in the PP film group (P<0.01), with the most pronounced increase in IL-4. The PU microporous film induced mild inflammation with no significant fibrous capsule formation in vivo. After 60 days of implantation, the film partially degraded, showing extensive collagen fiber growth and muscle formation in its central region. Conclusion: The PU microporous film exhibits good hydrophilicity and biocompatibility. Its surface morphology enhances cell adhesion, regulates the function of RAW264.7 macrophages, and promotes tissue repair, offering new insights for the design of pelvic floor repair and reconstruction patch materials.


Assuntos
Fibroblastos , Polipropilenos , Poliuretanos , Ratos Sprague-Dawley , Poliuretanos/química , Animais , Camundongos , Ratos , Polipropilenos/química , Fibroblastos/citologia , Materiais Biocompatíveis/química , Telas Cirúrgicas , Células RAW 264.7 , Propriedades de Superfície , Linhagem Celular , Porosidade , Teste de Materiais , Proliferação de Células/efeitos dos fármacos , Macrófagos/citologia
20.
J Glaucoma ; 33(9): 645-651, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39207444

RESUMO

PRCIS: Long-term success was achievable after GATT. GATT performed at early stage of glaucoma had better surgery outcomes. Trabeculoplasty may compromise surgery success. PURPOSE: To evaluate the long-term effectiveness of prolene suture gonioscopy-assisted transluminal trabeculotomy (GATT) and identify factors that may affect surgical outcomes. PATIENTS AND METHODS: This is a retrospective cohort study of adult patients with prolene suture GATT performed by a single surgeon at 1 medical center. RESULTS: Of the 145 eyes from 124 patients studied, intraocular pressure was reduced from 22.1±7.8 to 15.1±3.2 and 15.1±3.5 mm Hg, and the number of glaucoma medications was reduced from 3.2±1.1 to 1.3±1.4 and 1.4±1.5 at postoperative years 3 and 4, respectively. Ninety-three and 71 eyes completed a 3- and 4-year follow-up, with 44% of the eyes at year 4 remaining medication free. Compared with eyes with combined GATT/cataract extraction (CE), eyes with GATT alone had significantly more preoperative medications and a higher reoperation rate (31% vs. 16.5%). Eyes with prior trabeculoplasty had a higher reoperation rate (28.8%) than those without (16.1%). Kaplan-Meier survival analysis revealed that GATT/CE eyes without trabeculoplasty had a longer median time to failure (48 mo) than GATT/CE eyes with trabeculoplasty (18 mo), and GATT eyes with or without trabeculoplasty (9 and 12 mo, respectively). CONCLUSION: Prolene suture GATT successfully reduced IOP. Eyes with more preoperative medications responded less well to GATT. Prior laser trabeculoplasty was associated with poorer outcomes. Further study is needed to verify these findings.


Assuntos
Gonioscopia , Pressão Intraocular , Polipropilenos , Técnicas de Sutura , Suturas , Trabeculectomia , Humanos , Trabeculectomia/métodos , Pressão Intraocular/fisiologia , Estudos Retrospectivos , Feminino , Masculino , Seguimentos , Pessoa de Meia-Idade , Idoso , Resultado do Tratamento , Prognóstico , Tonometria Ocular , Glaucoma de Ângulo Aberto/cirurgia , Glaucoma de Ângulo Aberto/fisiopatologia , Adulto , Idoso de 80 Anos ou mais , Acuidade Visual/fisiologia
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