Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 19.747
Filtrar
1.
J Med Vasc ; 45(4): 177-183, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32571557

RESUMO

OBJECTIVE: To evaluate the short and long-term results of in situ prosthetic graft treatment using rifampicin-soaked silver polyester graft in patients with aortic infection. MATERIAL AND METHOD: All the patients surgically managed in our center for an aortic infection were retrospectively analyzed. The primary endpoint was the intra-hospital mortality, secondary outcomes were limb salvage, persistent or recurrent infection, prosthetic graft patency, and long-term survival. RESULTS: From January 2004 to December 2015, 18 consecutive patients (12 men and 6 women) were operated on for aortic infection. Six mycotic aneurysms and 12 prosthetic infections, including 8 para-entero-prosthetic fistulas, were treated. In 5 cases, surgery was performed in emergency. During the early postoperative period, we performed one major amputation and two aortic infections were persistent. Intra-hospital mortality was 27.7%. The median follow-up among the 13 surviving patients was 26 months. During follow-up, none of the 13 patients presented reinfection or bypass thrombosis. CONCLUSION: This series shows that in situ revascularization with rifampicin-soaked silver polyester graft for aortic infection have results in agreement with the literature in terms of intra-hospital mortality with a low reinfection rate.


Assuntos
Aneurisma Infectado/cirurgia , Antibacterianos/administração & dosagem , Aneurisma Aórtico/cirurgia , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Poliésteres , Infecções Relacionadas à Prótese/cirurgia , Rifampina/administração & dosagem , Prata , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Aneurisma Infectado/diagnóstico por imagem , Aneurisma Infectado/microbiologia , Aneurisma Infectado/mortalidade , Antibacterianos/efeitos adversos , Aneurisma Aórtico/diagnóstico por imagem , Aneurisma Aórtico/microbiologia , Aneurisma Aórtico/mortalidade , Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/mortalidade , Feminino , França , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Poliésteres/efeitos adversos , Desenho de Prótese , Infecções Relacionadas à Prótese/diagnóstico por imagem , Infecções Relacionadas à Prótese/microbiologia , Infecções Relacionadas à Prótese/mortalidade , Estudos Retrospectivos , Rifampina/efeitos adversos , Fatores de Risco , Prata/efeitos adversos , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
2.
Int J Nanomedicine ; 15: 3729-3740, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32547025

RESUMO

Background: Duraplasty is one of the most critical issues in neurosurgical procedures because the defect of dura matter will cause many complications. Electrospinning can mimic the 3D structure of the natural extracellular matrix whose structure is similar to that of dura matter. Poly(L-lactic acid) (PLLA) has been used to fabricate dura matter substitutes and showed compatibility to dural tissue. However, the mechanical properties of the PLLA substitute cannot match the mechanical properties of the human dura mater. Methods and Results: We prepared stereocomplex nanofiber membranes based on enantiomeric poly(lactic acid) and poly(D-lactic acid)-grafted tetracalcium phosphate via electrospinning. X-ray diffraction results showed the formation of stereocomplex crystallites (SC) in the composite nanofiber membranes. Scanning electron microscope observation images showed that composites nanofibers with higher SC formation can keep its original morphologies after heat treatment, suggesting the heat resistance of composite nanofiber membranes. Differential scanning calorimeter tests confirmed that the melting temperature of composite nanofiber membranes was approximately 222°C, higher than that of PLLA. Tensile testing indicated that the ultimate tensile strength and the elongation break of the stereocomplex nanofiber membranes were close to human dura matter. In vitro cytotoxicity studies proved that the stereocomplex nanofiber membranes were non-toxic. The neuron-like differentiation of marrow stem cells on the stereocomplex nanofiber membranes indicated its neuron compatibility. Conclusion: The stereocomplex nanofiber membranes have the potential to serve as a dura mater substitute.


Assuntos
Materiais Biomiméticos/química , Dura-Máter/fisiologia , Nanofibras/química , Poliésteres/química , Animais , Fosfatos de Cálcio/química , Varredura Diferencial de Calorimetria , Diferenciação Celular , Linhagem Celular , Cristalização , Humanos , Masculino , Células-Tronco Mesenquimais/citologia , Camundongos , Nanofibras/ultraestrutura , Neurônios/citologia , Ratos Sprague-Dawley , Estereoisomerismo , Temperatura , Difração de Raios X
3.
Bioresour Technol ; 311: 123536, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32448640

RESUMO

Polyhydroxybutyrates (PHBs) are a class of biopolymers produced by different microbial species and are biodegradable and biocompatible in nature as opposed to petrochemically derived plastics. PHBs have advanced applications in medical sector, packaging industries, nanotechnology and agriculture, among others. PHB is produced using various feedstocks such as glycerol, dairy wastes, agro-industrial wastes, food industry waste and sugars. Current focus on PHB research has been primarily on reducing the cost of production and, on downstream processing to isolate PHB from cells. Recent advancements to improve the productivity and quality of PHB include genetic modification of producer strain and modification of PHB by blending to develop desirable properties suited to diversified applications. Selection of feedstock plays a critical role in determining the economic feasibility and sustainability of the process. This review provides a bird's eye view of the suitability of different waste resources for producing polyhydroxybutyrate; providing state-of the art information and analysis.


Assuntos
Hidroxibutiratos , Plásticos , Biomassa , Biopolímeros , Resíduos Industriais , Poliésteres
4.
Environ Sci Pollut Res Int ; 27(23): 28949-28961, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32418110

RESUMO

This study is anchored on the use of an eco-friendly effective plasma technique and cationization treatment to improve the hydrophobic nature of polyester (PET) fabric by incorporating hydrophilic functional groups onto the PET surface. The PET surface was initially treated with three different plasma gases prior to cationization treatment with quaternary ammonium salt (Quat 188). Madder roots were used, to produce natural dyes for the green coloration of PET fabrics in both dyeing and printing processes. The color strength (K/S) was measured to study the influence of both plasma gases and the cationization treatment on the coloration of PET fabric. Exposure to nitrogen plasma gases prior to the cationization treatment showed promising results for efficient PET coloration, resulting in the selection of nitrogen as a working gas at a flow rate of 3 l/min. The results also demonstrated that by combining the nitrogen plasma technique and cationization treatment, PET fabric with a highly effective surface was obtained, resulting in improved coloration, wettability, tensile strength, and roughness properties.


Assuntos
Poliésteres , Têxteis , Cor , Corantes , Molhabilidade
5.
Chemosphere ; 256: 126985, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32445994

RESUMO

Biodegradable mulch films are an alternative to polyethylene films used in agriculture for weed control, improving crop productivity. This change could minimize the residue production and costs related to the final disposal. Nevertheless, the environmental safety of these biodegradable products is scarcely investigated. In this work, samples of poly(butylene adipate-co-terephthalate)-PBAT mulch films, with and without UV stabilizer additives, were prepared. Aqueous extracts of soil samples, where mulch films were disposed, were investigated using bioassays with Lactuca sativa, Allium cepa, and cell culture HepG2/C3A. As PBAT is expected to suffer photodegradation and biodegradation, soil samples mixed with films before and after these processes were evaluated. Soil aqueous extracts promoted root grown (mainly hypocotyl) of L. sativa, probably due to presence of nutrients. So, to evaluate toxicity potential, in this case it was necessary to use aqueous extract prepared with soil instead of ultrapure water as the control. After doing this analysis it was observed that no adverse impacts due to PBAT films occurred. No chromosomal abnormalities were observed in A. cepa bioassay for any of tested samples. The absence of genotoxic potential was confirmed by comet assay and micronucleus test using human hepatocarcinoma cell line HepG2/C3A. These results showed that the soil did not induce damage to the tested organisms, before and after degradation of PBAT films.


Assuntos
Biodegradação Ambiental , Alface/efeitos dos fármacos , Cebolas/efeitos dos fármacos , Adipatos , Agricultura , Alcenos , Ecotoxicologia , Humanos , Alface/fisiologia , Cebolas/fisiologia , Ácidos Ftálicos , Poliésteres/química , Poluentes do Solo
6.
Bioresour Technol ; 310: 123515, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32417073

RESUMO

The present investigation gives an insight on the potential of food and kitchen waste as a suitable feed stock for the production of biopolymer, biofuels, enzymes and chemicals. Media engineering improved poly-3-hydroxybutyrate (PHB) production from 0.91 g/L to 5.132 g/L. There is a five-fold increase in PHB production. The food and kitchen waste was also evaluated for the production of bioethanol, 2, 3 - butanediol, and pectinase. Saccharomyces cerevisiae produced 0.316 g of bioethanol, Bacillus sonorensis MPTD1 produced 2.47 (µM/mL)/min of pectinase and Enterobacter cloacae SG1 produced 3 g/L of 2, 3-butanediol with a productivity of 0.03 g/L/h using food and kitchen waste as carbon source. Targeting on multiple value added products will improve the overall process economics.


Assuntos
Hidroxibutiratos , Poligalacturonase , Butileno Glicóis , Fermentação , Poliésteres
7.
Acta Cir Bras ; 35(3): e202000302, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32401908

RESUMO

PURPOSE: To evaluate the healing potential of the electrospinning membranes of Poly (Lactic Acid) (PLA) associated with Sedum dendroideum extract in burn injuries in rats. METHODS: Seventy-five rats were submitted to burn injury on their back skin: (C) untreated; (F) with daily topical application of S. dendroideum extract; (M) with electrospinning membranes of PLA; (MF10) with electrospinning membranes of PLA with 10% S. dendroideum extract; (MF25) with electrospinning membranes of PLA with 25% S. dendroideum extract. Tissue samples were taken after 2, 6 and 14 days of the burn injury and were subjected to histomorfometric analysis of quantification of fibroblasts, collagen fibers, blood vessels, and inflammatory infiltrate Results: The histomorphometric analysis showed an increase in the number of fibroblasts, collagen fibers and blood vessels in the burns treated with membranes of PLA, associated or not with the 10% and 25% extract. The extract of S. dendroideum promoted the increase of collagen fibers. CONCLUSION: The electrospinning PLA membrane, isolated or associated with the S. dendrodeum extract, favored the healing of burn injuries in this experimental model, with an increase of fibroblasts, collagen fibers, and blood vessels. S. dendroideum isolated only stimulated the collagenesis.


Assuntos
Queimaduras/terapia , Membranas Artificiais , Extratos Vegetais/uso terapêutico , Poliésteres/administração & dosagem , Sedum/química , Cicatrização/efeitos dos fármacos , Animais , Terapia Combinada , Modelos Animais de Doenças , Masculino , Ratos , Ratos Wistar
8.
Int J Nanomedicine ; 15: 2633-2646, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32368045

RESUMO

Objective: The aim of this study is to fabricate functional scaffolds to gene delivery bone morphogenetic protein-2 (BMP-2) plasmid for bone formation in bone tissue engineering. Methods: Dendriplexes (DPs) of generation 4 polyamidoamin (G4-PAMAM)/BMP-2 plasmid were prepared through microfluidic (MF) platform. The physiochemical properties and toxicity of DPs were evaluated by DLS, AFM, FESEM and MTT assay. In order to create a suitable environment for stem cell growth and differentiation, poly-l-lactic acid (PLLA) and poly-l-lactic acid/poly (ethylene oxide) (PLLA/PEO) scaffolds containing hydroxyapatite nanoparticles (HA) and DPs were fabricated by the electrospinning method. The osteogenic potency of the scaffolds on human adipose tissue-derived mesenchymal stem cells (hASCs) was investigated. Results: The results revealed that tuning the physical properties of DPs by adjusting flow parameters in microfluidic platform can easily improve the cell viability compared to conventional bulk mixing method. Also, the result showed that the presence of HA and DPs in PLLA/PEO scaffold enhanced alkaline phosphatase (ALP) activity and increased the amount of deposited Ca, as well as, related to osteogenesis gen markers. Conclusion: This study indicated that on using the MF platform in preparation of DPs and loading them along with HA in PLLA/PEO scaffold, the osteogenic differentiation of hASCs could be tuned.


Assuntos
Proteína Morfogenética Óssea 2/metabolismo , Osso e Ossos/fisiologia , Durapatita/química , Microfluídica , Nanofibras/química , Poliaminas/química , Engenharia Tecidual/métodos , Tecidos Suporte/química , Fosfatase Alcalina/metabolismo , Cálcio/metabolismo , Adesão Celular , Morte Celular , Diferenciação Celular , Proliferação de Células , Forma Celular , DNA/metabolismo , Dendrímeros/química , Humanos , Células-Tronco Mesenquimais/metabolismo , Nanopartículas/química , Tamanho da Partícula , Plasmídeos/metabolismo , Poliésteres/química , Resistência à Tração
9.
Chemosphere ; 255: 126901, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32387904

RESUMO

Enhanced nitrate removal from the secondary effluent in municipal wastewater treatment plants (WWTPs) is essential for avoiding water eutrophication. To this end, a vertical baffled solid-phase denitrification reactor (VBSDR) was developed using a starch and polycaprolactone (PCL) blend plate (S-PCL) as a carbon source and biofilm carrier. In this study, we evaluated the denitrification performance and microbial diversity of the VBSDR. The results of the Fourier transform infrared spectroscopy (FTIR), carbon leaching experiment, and scanning electron microscopy (SEM) demonstrated that the S-PCL structure can be attached and degraded more rapidly. Furthermore, the denitrification performance under varied operational conditions, i.e., influent nitrate loading rate (NLR) and operating temperature, was also investigated. Herein, when treating low C/N ratio and low-strength wastewater, a high denitrification rate (DR) [0.33 gN/(L·d)] was achieved. The effect of temperature on DR can be described by the Arrhenius-type equation, which shows that low temperature has a negative influence on DR and nitrate removal efficiency. Furthermore, DR was simultaneously affected by the NLR and temperature. The microbial diversity and community structure were determined by Illumina high-throughput sequencing. The special carbon source led to Acidovorax (denitrifying bacteria) and Flavobacterium (hydrolysis acidifying bacteria) being the VBSDR biofilm's most predominant functional bacteria at the genus level.


Assuntos
Poliésteres/química , Eliminação de Resíduos Líquidos/métodos , Biofilmes , Reatores Biológicos/microbiologia , Carbono/química , Comamonadaceae , Desnitrificação , Nitratos/química , Nitrogênio/química , Amido/química , Temperatura , Águas Residuárias/química
10.
Environ Sci Pollut Res Int ; 27(21): 26276-26304, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32358757

RESUMO

In this study, a diversified waste recycling system and a green processing technology are proposed. This research not only finds feasible solutions to alleviate environmental problems of plastic pollution and straw burning but also provides new reuse methods for oyster shell waste and hogwash oil. The developed noval biocomposite material is conducive to the green development of express industry. This paper evaluates the performance of materials from many aspects: X-ray computed tomography characterization, fundamental physical properties, mechanical properties, microscopic morphology, SEM morphology, and comprehensive performance of products. Two kinds of products with economic value are found. One is sample 4, which is suitable for making granular products due to its low cost (0.328$/500 g). Another is sample 13, which is suitable for manufacturing green packaging materials due to its excellent mechanical properties (tensile strength 14.15 MPa; elongation at break 12.68%; Young's modulus 8189.89 MPa). Based on the experimental results, the process of the composite is simulated to study the different strengthening mechanisms of arabic gum and poly(methyl vinyl ether-alt-maleic anhydride). Arabic gum uses chemical reaction and principle of similarity and intermiscibility to fuse with biomass to form homogeneous hybrid in the form of liquid gel. Poly(methyl vinyl ether-alt-maleic anhydride) indirectly adheres filler to the matrix through ring-opening reaction and structural similarity. The new emulsification system caused by arabic gum promotes the arabic gum and nano-fluid coupling cross-linking system to produce a decentralized cross-linked network and inhibit the pernicious molecular chain entanglement.


Assuntos
Ostreidae , Reciclagem , Animais , Biomassa , Poliésteres
11.
Environ Pollut ; 264: 113960, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32375087

RESUMO

Synthetic fibers account for approximately 60% of the total global fiber production, and polyester (PET) and polyamide (PA) dominate. Synthetic fabrics are now widely used in clothing, upholstery, carpets and other such materials. Textiles based on these materials have the potential to release microplastics (<5 mm in size) into the environment during production and cleaning actions. These particles are released in sewage effluents, as washing machine filters and wastewater treatment plants are not specifically designed to retain them and represent an environmental pollution that continuously increases the scientific and societal concern about their effects on marine biota and ecosystems. This study was focused on the determination of the amount of microfibers release from 100% polyester fabrics, in different washing conditions (programs and temperatures), comparing the use of detergent alone vs detergent with a stain remover. Microplastics released were characterized and quantified with gravimetric analysis, different microscopic, spectroscopic and thermal techniques. Tests were carried out in replicates to assess the data reproducibility and to show statistical differences between washing conditions.


Assuntos
Lavanderia , Plásticos , Ecossistema , Microplásticos , Poliésteres , Reprodutibilidade dos Testes , Têxteis
12.
Environ Sci Technol ; 54(8): 4847-4855, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32250104

RESUMO

Microplastic fibers (MPFs) have been found to be a major form of microplastics in freshwaters, and washing of synthetic textiles has been identified as one of their main sources. The aim of this work was to use a panel of 12 different textiles of representative fibers and textile types to investigate the source(s) of the MPF during washing. Using standardized washing tests, textile swatches tailored using five different cutting/sewing methods were washed up to 10 times. The MPF quantity and fiber length were determined using image analysis. The 12 textiles demonstrated great variability in MPF release, ranging from 210 to 72,000 MPF/g textile per wash. The median MPF length ranged from 165 to 841 µm. The number of released MPF was influenced by the cutting method, where scissor-cut samples released 3-21 times higher numbers of MPF than the laser-cut samples. The textiles with mechanically processed surfaces (i.e., fleece) released significantly more (p-value < 0.001) than the textiles with unprocessed surfaces. For all textiles, the MPF release decreased with repeated wash cycles, and a small continuous fiber release was observed after 5-6 washings, accompanied by a slight increase in the fiber length. The decrease in the number of MPF released is likely caused by depletion of the production-inherited MPFs trapped within the threads or the textile structure. The comparison of MPF release from laser-cut samples, which had sealed edges, and the other cutting methods allowed us to separate the contributions of the edge- and surface-sourced fibers from the textiles to the total release. On an average, 84% (range 49-95%) of the MPF release originated from the edges, highlighting the importance of the edge-to-surface ratio when comparing different release studies. The large contribution of the edges to the total release offers options for technical solutions which have the possibility to control MPF formation throughout the textile manufacturing chain by using cutting methods which minimize MPF formation.


Assuntos
Plásticos , Poliésteres , Microplásticos , Têxteis
13.
J Environ Manage ; 266: 110493, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32310114

RESUMO

Composites containing bio-based materials, like banana fiber and poly(lactic acid) (PLA), are potential food-packaging materials. We carried out an environmental life cycle assessment (LCA) of coffee jar lids made from high density polyethylene (HDPE), PLA, and banana fiber to assess their environmental performance. We considered differences in the type of blend (content of PLA and banana fiber in the composite), origin of the banana fiber feedstock (considered as either biowaste or as a co-product from banana production) and banana fiber pretreatment conditions (either no pretreatment or pretreatment using chemicals). Irrespective of the scenario, a lid made from 40% banana fiber and equal amounts of HDPE and PLA performed significantly better in all 18 impact categories when compared to a lid made from 100% PLA. By contrast, the same lid performed significantly better in 3 impact categories only (climate change, photochemical oxidant formation and fossil depletion) when compared to a lid made from 100% HDPE. Thus, environmental performance of the biocomposite strongly depends on which polymer base is replaced by the banana fiber in the composite. Replacing PLA with banana fiber is generally expected to bring environmental benefits.


Assuntos
Musa , Café , Poliésteres , Polímeros
14.
Khirurgiia (Mosk) ; (3): 29-34, 2020.
Artigo em Russo | MEDLINE | ID: mdl-32271734

RESUMO

OBJECTIVE: Experimental assessment of the effect of modified and unmodified surgical suture material on abdominal adhesive process. MATERIAL AND METHODS: The study was performed on male rats of the Wistar subpopulation. There were 5 animals in each group. In all animals, midline abdominal incision was followed by suturing the parietal peritoneum with modified and unmodified suture material. All animals were euthanized with carbon dioxide vapors in 14 days after surgery. Macro- and microscopic assessment of severity of abdominal adhesive process was carried out. Two types of preparation of excised complexes 'peritoneum-suture material-adhesion' were applied for histological examination: paraffin sections and embedding in epoxy resin. Specimens were stained by Van Gieson and with methylene blue solution. Histological specimens were examined using Axio Imager A1 light microscope (Zeiss, Germany). RESULTS: Polypropylene filaments result extensive adhesions occupying about 75% of the area. Adhesions have a dense structure with signs of vascularization. Modification of suture material with solution of polyhydroxybutyrate/hydroxyvalerate and heparin reduce severity of adhesions. The use of modified suture material was followed by adhesions with more loose structure, no signs of vascularization. Adhesions occupied less than 25% of the area. Histological examination of excised complexes 'peritoneum-suture material-adhesion' revealed accumulation of inflammatory cells around the unmodified suture material, while there were no signs of tissue inflammatory process around the modified sutures. CONCLUSION: Application of polyhydroxybutyrate/hydroxyvalerate and heparin on the surface of surgical sutures is an effective method for prevention of abdominal adhesions.


Assuntos
Materiais Biocompatíveis/efeitos adversos , Heparina/administração & dosagem , Poliésteres/administração & dosagem , Polipropilenos/efeitos adversos , Suturas/efeitos adversos , Aderências Teciduais/prevenção & controle , Animais , Materiais Biocompatíveis/administração & dosagem , Materiais Revestidos Biocompatíveis/administração & dosagem , Materiais Revestidos Biocompatíveis/efeitos adversos , Modelos Animais de Doenças , Heparina/efeitos adversos , Masculino , Neovascularização Patológica/etiologia , Neovascularização Patológica/prevenção & controle , Peritônio/irrigação sanguínea , Peritônio/patologia , Peritônio/cirurgia , Poliésteres/efeitos adversos , Polipropilenos/administração & dosagem , Ratos , Ratos Wistar , Aderências Teciduais/etiologia , Aderências Teciduais/patologia
15.
Waste Manag ; 107: 82-90, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32278219

RESUMO

The thermal degradation behaviors and evolved products analysis of polyester paint and waste enameled wires during pyrolysis were studied. Thermogravimetric (TG) and differential thermogravimetric (DTG) analyses were performed to investigate the mass loss characteristics. The pyrolysis solid residues generated during the process under optimal condition were detailedly analyzed by Fourier-transform infrared spectroscopy (FTIR). Meanwhile, the pyrolysis gas and oil generated were analyzed by gas chromatography-mass spectrometry (GC-MS). Kinetic analysis adopted the Ozawa-Flynn-Wall (OFW) model to confirm the reaction series by the variation pattern of activation energy. The results indicated that the pyrolysis of polyester paint and waste polyester enameled wires can be divided into three stages. The average activation energy of polyester paint and waste polyester enameled wires pyrolysis was 323.34 kJ/mol and 215.95 kJ/mol, respectively. The optimized pyrolysis temperature for polyester paint and waste polyester enameled wires was 500 °C and 900 °C, respectively. The chemical compositions of the pyrolysis residues of polyester paint and waste polyester enameled wires were basically same, mainly containing the compounds with CH, CO, aromatic ring, methyl, and aromatics bonds. The pyrolysis gas of polyester paint was mainly composed of C2H6, while that of waste polyester enameled wires mainly consisted of C2H6 and C4H8O. The main components of the pyrolysis oil polyester paint and waste polyester enameled wires were basically same, mainly containing long chain hydrocarbons, long chain alkenes, alcohols, phenol, ketone, aldehyde, and aromatic.


Assuntos
Poliésteres , Pirólise , Cinética , Pintura , Termogravimetria
16.
Waste Manag ; 107: 227-234, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32311640

RESUMO

With the focus of industries shifting towards sustainable processing methods and the use of sustainable raw materials, reuse and recycling of polyester have gained a lot of momentum. In spite of considerable efforts, the utilization of polyester fiber waste has not yet found a strong foundation in textile processing. In this paper, waste polyester fibers obtained during the melt spinning process has been utilized by first dissolving it in an m-cresol solvent and later by chemical route polyester is regenerated on cotton leading to the preparation of cotton based composite fabric. The presence of polyester was confirmed using XRD, FTIR, and percent add on and SEM. Percent add on of 9.7% along with the doubling of tensile strength and enhanced thermal stability was observed. The results can make a way as one of the possibilities of utilizing polyester fiber waste.


Assuntos
Poliésteres , Têxteis , Reciclagem , Resistência à Tração
17.
Int J Nanomedicine ; 15: 2259-2268, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32280218

RESUMO

Purpose: This study was designed to determine the potential effect of nanoencapsulated bioactive compounds from different natural sources on human pancreatic cancer. Background: Pancreatic cancer carries the highest fatality rate among all human cancers because of its high metastatic potential and late presentation at the time of diagnosis. Hence there is a need for improved methods to prevent and treat it. Natural products, such as 3, 3'-diindolylmethane (DIM) and ellagic acid (EA) demonstrated anticancer efficacy against various cancer types. However, DIM is insoluble. Hence, using nanotechnology to encapsulate these compounds in combination with EA might improve their physical and chemical properties and their delivery to the cancer cells. Methods: Human pancreatic cancer cells, namely SUIT2-luciferase transfected, were used to examine the effects of DIM or EA and their nanoformulation in poly(lactic-co-glycolic acid) (PLGA) and poly(ethylene glycol) (PEG) [PLGA-PEG] nanoparticles (NPs) on SUIT2-luciferase cell viability/proliferation over 24 hrs. Additionally, effects on tumor weight and angiogenesis were determined using the chick chorioallantoic membrane (CAM) tumor implant model. Results: Both DIM and EA PLGA-PEG NPs resulted in rapid suppression of pancreatic cancer cell viability/proliferation within 24 hrs (P < 0.01), while the non-encapsulated DIM and EA did not show any significant effect on SUIT2 cancer cell viability or cell proliferation (MTT assay). In the CAM pancreatic cancer cell (SUIT2) implant model, results showed a greater suppression of tumor weight (P < 0.01), tumor cell viability, and tumor angiogenesis (P < 0.01) for DIM NPs and EA NPs and their combinations versus DIM or EA alone. Conclusion: Nanoformulation of DIM and EA resulted in a more effective suppression of pancreatic cancer cell viability, pancreatic tumor weight, implanted cancer cell viability, and tumor angiogenesis as compared with these bioactive compounds alone.


Assuntos
Antineoplásicos/farmacologia , Produtos Biológicos/química , Ácido Elágico/farmacologia , Indóis/farmacologia , Nanopartículas/química , Neoplasias Pancreáticas/tratamento farmacológico , Animais , Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Produtos Biológicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Embrião de Galinha , Membrana Corioalantoide/efeitos dos fármacos , Ácido Elágico/administração & dosagem , Humanos , Indóis/administração & dosagem , Nanopartículas/uso terapêutico , Neoplasias Pancreáticas/patologia , Poliésteres/química , Polietilenoglicóis/química
18.
Environ Sci Pollut Res Int ; 27(17): 21560-21569, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32279252

RESUMO

To explore an effective approach of simultaneous nitrification and denitrification in wastewater with low C/N ratios, integrated packed bed bioreactors based on poly(3-hydroxybutyrate-hydroxyvalerate) (PHBV) with different dosing methods were designed. The removal efficiency of NH4+-N in bioreactor with aeration was 88.62%, and higher NO3--N removal efficiency was observed in bioreactor filled with grainy PHBV (95.21%) than bioreactor filled with strip PHBV (93.34%). Microbial study indicated that microbes harboring amoA and nirS genes preferred to attach on the surface of ceramsite, and significant differences in microbial community compositions at phylum and genus levels were observed. To summarize, it is feasible to utilize grainy PHBV for simultaneous and efficient removal of NH4+-N and NO3--N from wastewater with low C/N ratios.


Assuntos
Desnitrificação , Nitrificação , Reatores Biológicos , Carbono , Nitrogênio , Poliésteres , Eliminação de Resíduos Líquidos , Águas Residuárias
19.
Bioresour Technol ; 307: 123247, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32234592

RESUMO

A novel closed-loop biorefinery model using carob pods as the feed material was developed for PHB production. The carob pods were delignified, and as the second step, sugars present in the delignified carob pods were extracted using water. Ralstonia eutropha and Bacillus megaterium were cultivated on the carob pod extract and its performance was evaluated using Taguchi experimental design. R. eutropha outperformed the B. megaterium in terms of its capability to grow at a maximum initial sugar concentration of 40 g L-1 with a maximum PHB production of 12.2 g L-1. Finally, the concentrated lignin from the first step was diluted with different proportion of chloroform to extract PHB from the bacterial biomass. The PHB yield and purity obtained were more than 90% respectively using either R. eutropha or B. megaterium. Properties of the PHB produced in this study were examined to establish its application potential.


Assuntos
Cupriavidus necator , Lignina , Galactanos , Hidroxibutiratos , Mananas , Gomas Vegetais , Poliésteres , Açúcares
20.
Medicine (Baltimore) ; 99(17): e19861, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32332646

RESUMO

The best treatment for medial humeral epicondyle fractures in children has been debated. In case of incarceration of the epicondylar fragment, particularly after elbow dislocation, several materials are used for fixation, including Kirschner wires (K-wires), metallic compression screws, tension band wire, and suture anchors. Herein, we introduce a new fixation material: the absorbable self-reinforced polylactide (SR-PLA) pin.The aim of the study was to prove the feasibility of a new fixation material (absorbable SR-PLA pins) for the treatment of medial epicondyle fracture in children.Thirty-two patients who underwent surgery in our hospital from August 2007 to January 2012 were retrospectively analyzed. The patients were divided into group A (K-wires) and group B (absorbable SR-PLA pin). Group A comprised 11 males and 4 females, aged 8 to 14 years (average, 12.6 years), with 12 patients with elbow dislocation. Group B comprised 13 males and 4 females, aged 7 to 15 years (average, 11.8 years), with 13 patients with elbow dislocation. The same approach was used for all patients by the same team of surgeons, and all the patients were followed up for over 12 months. In all patients, rehabilitation training was started after 3 weeks. The Broberg and Morrey elbow scale was used to evaluate elbow function at follow-up.Four patients from group A developed pin-track infections that gradually resolved after removal of the K-wires, whereas no infections occurred in group B. One patient refractured her humerus after K-wire removal. Using the Broberg and Morrey elbow scale, outcomes in group A were classified as excellent in 5 patients (33.33%), good in 7 patients (46.67%), fair in 2 patients (13.33%), and poor in 1 (0.07%). Group B outcomes were scored as excellent in 12 patients (70.58%), good in 4 (23.53%), and fair in 1 (0.06%) and no patient (0.00%) had a poor outcome. The average Broberg and Morrey score for group A was significantly lower than that for group B (83.27 ±â€Š7.02 vs 95.21 ±â€Š5.04; P = .0238).Absorbable SR-PLA pins can be safely used for medial epicondyle fractures in children. Our results indicate that SR-PLA pins are associated with better short-term functional outcome than K-wires.Level of evidence: III.


Assuntos
Implantes Absorvíveis , Pinos Ortopédicos , Fixação Interna de Fraturas/instrumentação , Fraturas do Úmero/cirurgia , Poliésteres , Adolescente , Criança , Estudos de Viabilidade , Feminino , Seguimentos , Fratura-Luxação/cirurgia , Fixação Interna de Fraturas/métodos , Humanos , Masculino , Recuperação de Função Fisiológica , Estudos Retrospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA