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1.
Biochem Biophys Res Commun ; 732: 150406, 2024 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-39032412

RESUMO

Lignocellulose, the most abundant organic waste on Earth, is of economic value because it can be converted into biofuels like ethanol by enzymes such as ß-glucosidase. This study involved cloning a ß-glucosidase gene named JBG from the rumen fungus Neocallimastix patriciarum J11. When expressed recombinantly in Escherichia coli, the rJBG enzyme exhibited significant activity, hydrolyzing 4-nitrophenyl-ß-d-glucopyranoside and cellobiose to release glucose. Surprisingly, the rJBG enzyme also showed hydrolytic activity against ß-glucan, breaking it down into glucose, indicating that the rJBG enzyme possesses both ß-glucosidase and ß-glucanase activities, a characteristic rarely found in ß-glucosidases. When the JBG gene was expressed in Saccharomyces cerevisiae and the transformants were inoculated into a medium containing ß-glucan as the sole carbon source, the ethanol concentration in the culture medium increased from 0.17 g/L on the first day to 0.77 g/L on the third day, reaching 1.3 g/L on the fifth day, whereas no ethanol was detected in the yeast transformants containing the recombinant plasmid pYES-Sur under the same conditions. These results demonstrate that yeast transformants carrying the JBG gene can directly saccharify ß-glucan and ferment it to produce ethanol. This gene, with its dual ß-glucosidase and ß-glucanase activities, simplifies and reduces the cost of the typical process of converting lignocellulose into bioethanol using enzymes and yeast.


Assuntos
Neocallimastix , Proteínas Recombinantes , beta-Glucosidase , beta-Glucosidase/genética , beta-Glucosidase/metabolismo , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , Animais , Neocallimastix/genética , Neocallimastix/metabolismo , Neocallimastix/enzimologia , Rúmen/microbiologia , Clonagem Molecular , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , beta-Glucanas/metabolismo , Etanol/metabolismo , Lignina/metabolismo
2.
J Environ Sci (China) ; 126: 565-574, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36503782

RESUMO

Excessive consumption of energy and resources is a major challenge in wastewater treatment. Here, a novel heterogeneous Fenton-like catalyst consisting of Cu-doped graphene-like catalysts (Cu-GCD NSs) was first synthesized by an enhanced carbothermal reduction of ß-cyclodextrin (ß-CD). The catalyst exhibits excellent Fenton-like catalytic activity for the degradation of various pollutants under neutral conditions, accompanied by low H2O2 consumption. The results of structural characterization and theoretical calculations confirmed that the dual reaction centers (DRCs) were constructed on Cu-GCD NSs surface through C-O-Cu bonds supported on zero-valent copper species, which play a significant role in the high-performance Fenton-like reaction. The pollutants that served as electron donors were decomposed in the electron-poor carbon centers, whereas H2O2 and dissolved oxygen obtained these electrons in the electron-rich Cu centers through C-O-Cu bonds, thereby producing more active species. This study demonstrates that the electrons of pollutants can be efficiently utilized in Fenton-like reactions by DRCs on the catalyst surface, which provides an effective strategy to improve Fenton-like reactivity and reduce H2O2 consumption.


Assuntos
Poluentes Ambientais , Purificação da Água , beta-Ciclodextrinas , Polímeros , Elétrons , Peróxido de Hidrogênio
3.
Int J Mol Sci ; 23(10)2022 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-35628265

RESUMO

As a conventional medical dressing, medical gauze does not adequately protect complex and hard-to-heal diabetic wounds and is likely to permit bacterial entry and infections. Therefore, it is necessary to develop novel dressings to promote wound healing in diabetic patients. Komagataeibacter intermedius was used to produce unmodified bacterial cellulose, which is rarely applied directly to diabetic wounds. The produced cellulose was evaluated for wound recovery rate, level of inflammation, epidermal histopathology, and antimicrobial activities in treated wounds. Diabetic mices' wounds treated with bacterial cellulose healed 1.63 times faster than those treated with gauze; the values for the skin indicators in bacterial cellulose treated wounds were more significant than those treated with gauze. Bacterial cellulose was more effective than gauze in promoting tissue proliferation with more complete epidermal layers and the formation of compact collagen in the histological examination. Moreover, wounds treated with bacterial cellulose alone had less water and glucose content than those treated with gauze; this led to an increase of 6.82 times in antimicrobial protection, lower levels of TNF-α and IL-6 (39.6% and 83.2%), and higher levels of IL-10 (2.07 times) than in mice wounds treated with gauze. The results show that bacterial cellulose produced using K. intermedius beneficially affects diabetic wound healing and creates a hygienic microenvironment by preventing inflammation. We suggest that bacterial cellulose can replace medical gauze as a wound dressing for diabetic patients.


Assuntos
Celulose , Diabetes Mellitus Experimental , Acetobacteraceae , Animais , Celulose/farmacologia , Humanos , Inflamação , Camundongos , Cicatrização
4.
Environ Sci Technol ; 52(6): 3608-3614, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29431432

RESUMO

Efficient cycling of Fe3+/Fe2+ is a key step for the Fenton reaction. In this exploration, from microalgae, we have prepared a novel Fe-N-graphene wrapped Al2O3/pentlandite composite which showed high Fenton catalytic ability through accelerating of Fe3+ reduction. The catalyst exhibits high activity, good reusability along with stability, and wide adaptation for the organics degradation under neutral pH. High TON and H2O2 utilization efficiency have also reached by this catalyst. Characterization results disclose a unique structure that the layered Fe-N-graphene structure tightly covers on Al2O3/pentlandite particles. Mechanistic evidence suggests that the accelerated Fe3+/Fe2+ redox cycle originates from the enhanced electron transfer by the synergistic effect of Fe, Ni and Al in the catalyst, and it causes the low H2O2 consumption and high •OH generation rate. Moreover, organic radicals formed in the Fenton process also participate in the Fe3+ reduction, and this process may be accelerated by the N doped graphene through a quick electron transfer. These findings stimulate an approach with great potential to further extend the synthetic power and versatility of Fenton catalysis through N doped graphene in catalysts.


Assuntos
Grafite , Microalgas , Ligas , Catálise , Peróxido de Hidrogênio , Ferro
5.
Environ Sci Pollut Res Int ; 31(20): 29434-29448, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38575820

RESUMO

Microplastics (MPs) migrate by adsorbing heavy metals in aquatic environments and act as their carriers. However, the aging mechanisms of MPs in the environment and the interactions between MPs and heavy metals in aquatic environments require further study. In this study, two kinds of materials, polyamide (PA) and polylactic acid (PLA) were used as target MPs, and the effects of UV irradiation on the physical and chemical properties of the MPs and the adsorption behavior of Cu(II) were investigated. The results showed that after UV irradiation, pits, folds and pores appeared on the surface of aged MPs, the specific surface area (SSA) increased, the content of oxygen-containing functional groups increased, and the crystallinity decreased. These changes enhanced the adsorption capacity of aged MPs for Cu(II) pollutants. The adsorption behavior of the PA and PLA MPs for Cu(II) conformed to the pseudo-second-order model and Langmuir isotherm model, indicating that the monolayer chemical adsorption was dominant. The maximum amounts of aged PA and PLA reached 1.415 and 1.398 mg/g, respectively, which were 1.59 and 1.76 times of virgin MPs, respectively. The effects of pH and salinity on the adsorption of Cu(II) by the MPs were significant. Moreover, factors such as pH, salinity and dosage had significant effects on the adsorption of Cu(II) by MPs. Oxidative complexation between the oxygen-containing groups of the MPs and Cu(II) is an important adsorption mechanism. These findings reveal that the UV irradiation aging of MPs can enhance the adsorption of Cu(II) and increase their role as pollutant carriers, which is crucial for assessing the ecological risk of MPs and heavy metals coexisting in aquatic environments.


Assuntos
Cobre , Microplásticos , Poluentes Químicos da Água , Adsorção , Cobre/química , Poluentes Químicos da Água/química , Microplásticos/química , Poliésteres/química
6.
Huan Jing Ke Xue ; 44(5): 2551-2561, 2023 May 08.
Artigo em Zh | MEDLINE | ID: mdl-37177929

RESUMO

Urban rivers have been regarded as the "hotspots" for microplastic (MPs) and metal contamination as they play important roles in pollution migration. However, as important sinks and sources of resistance genes, there has been little to no research investigating the associations between MPs, metal contaminations, and metal resistance genes (MRGs). Ten water samples were collected from the Huangpu River in situ; along with metal elements, MPs characteristics analyzed. Metal resistance genes and mobile genetic elements (MGEs) in waters and MPs were detected using metagenomic technology. As a result, the highest metal concentration was that of Sb in surface water (3.16±0.419) µg·L-1. The average abundance of MPs was (1.78±0.84) n·L-1, and the peak levels located in industrial and densely populated areas, which was significantly higher than those in agricultural and low population density areas. Fibrous, small-size (<0.5 mm), and transparent polyethylene terephthalate (PET) were the largest contributors of MPs. Eighteen MRGs were detected in all the samples. The relative abundance of MRGs in water was 1.68±0.21. The most dominant MRGs subtypes were merR and ruvB, which are subtypes resistant to mercury and Multi_metals. Correlation analysis showed that chromium and nickel in waters were significantly positively associated with MRG-Cr, MRG-Ni, and Multi_metals resistance genes. For MPs particles, the relative abundance of MRGs was 1.63±0.53. The most dominant MRGs subtypes were merT-P and copB, which also belong to mercury-resistant and Multi_metals. The Multi_metals resistance gene, ctpC, cueA, czrA, kmtR, etc., had significant positive associations with Ni, Cr, and Sb in waters. Compared with water samples, MPs selectively enriched merT-P, copB, ziaA, sodA, and dmeF. Additionally, the co-occurrence patterns of MRGs and MGEs were explored based on network analysis. In water samples, the transposases (tnpA_1 and tnpA_2), integrase (qacEdelta), and insertion sequence (IS91) were the major contributors of the horizontal gene transfer (HGT) of specific MRGs. Multiple subtypes resistant to copper and Multi_metals resistance genes on MPs were positively associated with IncFIC(FII), Rep7, rep7, and rep13, which were subtypes of plasmids. The presence of MPs exerted a significant impact on HGT of specific MRGs mediated by plasmids.


Assuntos
Mercúrio , Microplásticos , Genes Bacterianos , Plásticos , Rios , Água , Metais , Antibacterianos
7.
Water Res ; 229: 119460, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36493700

RESUMO

Bifunctional photocatalytic nanofiltration (PNF) membrane is increasingly concerned in practical micro-polluted water purification, but there are still several bottlenecks that inhibit its practicality. In this context, the feasibility of a novel metal-free and visible light-responsive surface-anchored PNF membrane for simultaneously removing target antibiotics in real sewage effluent in a continuous dynamic process was explored. The results showed that the optimal PNF-4 membrane was expectedly consisted of an inside tight sub-nanopore structured separation layer and an outside thinner, smoother, super hydrophilic mesoporous degradation layer, respectively. Consequently, the activated PNF-4 membrane could synergistically reduce trimethoprim and sulfamethoxazole concentrations to below two orders of magnitude, accompanying with almost constant high water permeability, suggesting that the hydrophilic modification of the mesoporous degradation layer basically offsets its inherent hydraulic resistance. Also, after repeating the fouling-physical rinsing process three times lasted for 78 h, only sporadic adherent contaminants remained onto the top surface, together with the minimal total and irreversible fouling ratios (as low as 7.2% and 1.2%, respectively), strongly demonstrated that PNF-4 membrane displayed good self-cleaning performance. Undoubtedly, this will significantly reduce its potential cleaning frequency and maintenance cost in long-term operation. Meanwhile, the acute and chronic biotoxicities of its permeate to Virbrio qinghaiensis sp. -67 were also reduced sharply to 2.22% and 0.45%, respectively. All of these evidences suggest that the dual functions of PNF-4 membrane are synergetic in an uninterrupted permeating process. It will provide useful insights for continuously enhancing the practicality and effectiveness of PNF membrane in actual micro-polluted water purification scenarios.


Assuntos
Antibacterianos , Purificação da Água , Esgotos , Luz , Sulfametoxazol , Trimetoprima , Membranas Artificiais , Purificação da Água/métodos
8.
Ann Plast Surg ; 69(3): 316-25, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21629102

RESUMO

Distraction osteogenesis requires a long consolidation period and has a low but real failure rate. Bone morphogenetic proteins (BMPs) accelerate bone deposition in fractures and critical-sized bone defects. Vascular endothelial growth factor (VEGF) is a promising reagent for inducing angiogenesis, and is an essential coordinator of extracellular matrix remodeling, angiogenesis, and bone formation in the growth plate. However, their effects on mandibular distraction osteogenesis are unknown. We investigated the effect of local delivery of plasmid pIRES-hBMP-2-hVEGF165 into a distraction area by electroporation-mediated approach.A New Zealand rabbit model were used. Activation of the device was commenced after 3 days of latency period and proceeded at the rate of 0.8 mm per day for 7 days. After the completion of activation, the rabbits were randomly divided into 5 groups: group A: recombinant plasmid 2 µg (0.1 µg/µL) pIRES-hVEGF165-hBMP2 was injected into the distraction area after the completion of activation; group B: recombinant plasmid pIRES-hBMP2 was injected into the distraction area; group C: recombinant plasmid pIRES-hVEGF165 was injected into the distraction area; group D: pIRES was injected into the distraction area, and group E: normal saline was injected into the distraction area. After injection every group used electroporation. Subsequently, the rabbits were examined by quantitative computed tomography, mechanical testing, and histomorphometric analysis.BMD of newly formed bone of the distraction area in groups A, B, and C were remarkably higher than those of groups D and E at different times (P < 0.001). At 4 and 8 weeks of consolidation, the crushing strength of 3 points of the newly formed bone in group A was remarkably higher than those of groups B, C, D, and E (P < 0.01). The results demonstrated statistically remarkable increase in regenerated bone in the gene-transfected groups.Electroporation-mediated transfecting recombinant plasmid pIRES-hVEGF165-hBMP2 could produce a satisfactory proceeding of osteogenesis and calcification, which surpassed that of the control group. This finding indicates that a combination of VEGF and BMP may make osteogenesis and angiogenesis appear at the same time. Furthermore, it may magnify the effect of single growth factor, and promote growth and reparative process of bone.


Assuntos
Proteína Morfogenética Óssea 2/administração & dosagem , Eletroporação , Mandíbula/cirurgia , Osteogênese por Distração/métodos , Plasmídeos , Proteínas Recombinantes/administração & dosagem , Transfecção/métodos , Fator A de Crescimento do Endotélio Vascular/administração & dosagem , Animais , Coelhos
9.
Carbohydr Polym ; 296: 119929, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36087981

RESUMO

Due to the serious threat of methanol to human health, the convenient, quick and specific detection of methanol is of great importance. Therefore, in this study, a biomass-derived chiral nematic composite film is fabricated by the co-evaporation of cellulose nanocrystals (CNC) and water-soluble polymer of ß-cyclodextrin (PCD). The freestanding iridescent CNC-PCD film shows distinguishing structural colors of red and yellow green for methanol and ethanol respectively, realizing the identification of the two homologous alcohols by naked eyes. Besides, the quick, reversible and quantitative colorimetric sensing of the CNC-PCD film to methanol is verified. As its structural color and maximum reflection wavelength redshift to the greatest extent for methanol than other alcohols, the CNC-PCD film exhibits the specificity and selectivity for methanol detection in both single and mixed solvents. Such less-consumed and easy-to-handle CNC-PCD film may be useful as a colorimetric sensor to detect or discriminate methanol in some industrial products.


Assuntos
Nanopartículas , beta-Ciclodextrinas , Celulose/química , Humanos , Metanol , Nanopartículas/química , Polímeros
10.
ACS Appl Mater Interfaces ; 12(9): 10993-11004, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32031778

RESUMO

Sodium hypochlorite (NaClO) solution is a typical cleaning agent for membrane fouling. However, it can damage membrane chemical structures and produce toxic disinfection byproducts, which in turn reduces the membrane performance. This study focuses on the fabrication of active membranes thereby overcoming the limitations of chemical cleaning. A hierarchical active poly(vinylidene fluoride) membrane with polydopamine/polyethyleneimine (PEI) co-supported iron nanoparticle (Fe NP) catalysts was successfully constructed and denoted as a Fe-HP-membrane. The Fe-HP-membrane exhibited excellent advanced oxidation activity with maximum flux recoveries (∼85% with bovine serum albumin [BSA] and ∼95% with humic acid [HA] solutions). After the static experiment of ∼30 days, the BSA proteins and HA successfully desorbed from the membrane surface. Especially, with a trace amount of hydrogen peroxide (H2O2) flowing over the surface of the Fe-HP-membrane, highly exposed active sites were observed. Membrane cleaning showed that the "outside-to-in" active surfaces generated considerable amounts of •OH radicals at the interface of BSA or HA and the fouled membrane. As a result, the unwanted foulants were successfully removed from the membrane interface, enabling multiple use of the Fe-HP-membrane. Therefore, backwashing with a small amount of H2O2 (0.33 wt %) covered ∼20% of the flux. In contrary, backwashing with NaClO (1 wt %) can only achieve a flux recovery of ∼10% after six consecutive BSA filtration cycles. The Fe-HP-membrane exhibited better HA foulant removal (a flux recovery of ∼51%) after backwashing with H2O2 than using NaClO (a flux recovery of ∼43%). Our findings demonstrate a new platform for water treatment and regeneration of fouled membranes.


Assuntos
Filtração/instrumentação , Ferro/química , Polivinil/química , Purificação da Água/instrumentação , Adsorção , Animais , Bovinos , Filtração/métodos , Substâncias Húmicas/análise , Peróxido de Hidrogênio/química , Membranas Artificiais , Soroalbumina Bovina/química , Purificação da Água/métodos
11.
J Vet Med Sci ; 70(9): 1001-4, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18840980

RESUMO

Maxillary bone epithelial cyst is rare in dogs. A 5-year-old, spayed female miniature schnauzer developed a swelling below the nasal canthus of left eye. Plain radiograph demonstrated a 1.5 cm diameter of radiolucent lesion on the maxillary bone anteroventral to the eye, and contrast dacryocystorhinography confirmed an obstructed nasolarcrimal duct. The swelling showed poor response to antibiotic treatment but responded well to oral prednisolone. Exploratory surgery revealed a cyst-like structure filled with brown serous fluid. Histopathological examination of the removed cyst revealed a double cuboidal epithelial cyst. The dog recovered rapidly after surgery, and the swelling had not recurred for a 36-month follow-up. It is the first case of periorbital bone epithelial cyst reported in an adult miniature schnauzer.


Assuntos
Cistos Ósseos/veterinária , Doenças do Cão/patologia , Doenças do Cão/cirurgia , Maxila/diagnóstico por imagem , Animais , Cistos Ósseos/tratamento farmacológico , Cistos Ósseos/patologia , Cistos Ósseos/cirurgia , Doenças do Cão/tratamento farmacológico , Cães , Feminino , Prednisolona/uso terapêutico , Radiografia
12.
Environ Pollut ; 234: 71-78, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29161575

RESUMO

Effects of sulfadiazine and ciprofloxacin on the occurrence of free-living and particle-associated opportunistic pathogens in bulk water of simulated drinking water distribution systems (DWDSs) were investigated. It was found that sulfadiazine and ciprofloxacin greatly promoted the occurrence of opportunistic pathogens including Pseudomonas aeruginosa, Legionella pneumophila, Mycobacterium avium and its broader genus Mycobacterium spp., as well as the amoebae Acanthamoeba spp. and Hartmanella vermiformis, in bulk water of DWDSs. Moreover, sulfadiazine and ciprofloxacin exhibited much stronger combined effects on the increase of these opportunistic pathogens. Based on the analysis of the antibiotic resistance genes (ARGs) and extracellular polymeric substances (EPS), it was verified that EPS production was increased by the antibiotic resistant bacteria arising from the effects of sulfadiazine/ciprofloxacin. The combined effects of sulfadiazine and ciprofloxacin induced the greatest increase of EPS production in DWDSs. Furthermore, the increased EPS with higher contents of proteins and secondary structure ß-sheet led to greater bacterial aggregation and adsorption. Meanwhile, large numbers of suspended particles were formed, increasing the chlorine-resistance capability, which was responsible for the enhancement of the particle-associated opportunistic pathogens in bulk water of DWDSs with sulfadiazine/ciprofloxacin. Therefore, sulfadiazine and ciprofloxacin promoted the occurrence of particle-associated opportunistic pathogens in bulk water of DWDSs due to the role of EPS produced by the bacteria with ARGs.


Assuntos
Antibacterianos , Bactérias/isolamento & purificação , Ciprofloxacina , Água Potável/microbiologia , Sulfadiazina , Poluentes da Água/isolamento & purificação , Amoeba/isolamento & purificação , Bactérias/metabolismo , Biopolímeros/metabolismo , Cloro , Desinfetantes , Farmacorresistência Bacteriana , Microbiologia da Água , Abastecimento de Água
13.
Int J Biol Macromol ; 114: 1186-1193, 2018 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-29625220

RESUMO

Enhancing the performance of wood adhesive is important for its industrial applications. Accordingly, we designed and demonstrated the use of two co-monomers vinyl acetate (VAc) and butyl acrylate (BA) for promoting the graft copolymerization while improving the bonding performance of wood adhesive. The results showed that the addition of co-monomers in the ratio of VAc/BA 6:4 (v/v, volume basis of VAc) could improve the shear strength to 6.68MPa and 3.32MPa in dry and wet states, respectively. 1H-nuclear magnetic resonance (1H NMR) and fourier transform infrared spectroscopy (FT-IR) analysis revealed successful graft copolymerization reaction while the morphologies were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Furthermore, the grafting reaction and thermal stabilities of wood adhesive were analyzed by X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). The results showed that the properties of wood adhesive could improve dramatically by using two co-monomers VAc and BA during the graft copolymerization reaction.


Assuntos
Acrilatos/química , Adesivos , Polivinil/química , Amido/química , Madeira/química , Adesivos/síntese química , Adesivos/química
14.
Sci Rep ; 8(1): 14253, 2018 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-30250121

RESUMO

We developed an osseocompatible ß-type Ti-28Nb-11Ta-8Zr (TNTZ) alloy that displays the excellent elastic modulus, cellular response, corrosion resistance and antibacterial capability demanded for bone-mimetic materials. The TNTZ alloy exhibited an elastic modulus of 49 GPa, which approximates that of human bones and prevent stress shielding effects. A further anodic oxidation and subsequent post-annealing modification formed a crystalline nanoporous TNTZ oxide layer (NPTNTZO(c)) on the alloy surface, potentially promoting interlocking with the extracellular matrix of bone cells and cell proliferation. Osteoblast viability tests also verified that NPTNTZO(c) enhanced cell growth more significantly than that of flat TNTZ. In addition, potentiodynamic polarization tests in Hanks' balanced salt solution (HBSS) revealed that both TNTZ and NPTNTZO(c) exhibited better corrosion resistance than commercial pure titanium. Finally, NPTNTZO(c) reinforced with silver nanoparticles (NPTNTZO


Assuntos
Nióbio/química , Osteoblastos/efeitos dos fármacos , Tantálio/química , Titânio/química , Zircônio/química , Antibacterianos/química , Antibacterianos/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/uso terapêutico , Corrosão , Humanos , Teste de Materiais , Nanopartículas Metálicas/química , Nanopartículas Metálicas/uso terapêutico , Nióbio/uso terapêutico , Osteoblastos/citologia , Oxirredução/efeitos dos fármacos , Prata/química , Tantálio/uso terapêutico , Titânio/uso terapêutico , Zircônio/uso terapêutico
15.
Chemosphere ; 212: 262-271, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30145418

RESUMO

Academics researchers and "citizen scientists" from 22 countries confirmed that yellow mealworms, the larvae of Tenebrio molitor Linnaeus, can survive by eating polystyrene (PS) foam. More detailed assessments of this capability for mealworms were carried out by12 sources: five from the USA, six from China, and one from Northern Ireland. All of these mealworms digested PS foam. PS mass decreased and depolymerization was observed, with appearance of lower molecular weight residuals and functional groups indicative of oxidative transformations in extracts from the frass (insect excrement). An addition of gentamycin (30 mg g-1), a bactericidal antibiotic, inhibited depolymerization, implicating the gut microbiome in the biodegradation process. Microbial community analyses demonstrated significant taxonomic shifts for mealworms fed diets of PS plus bran and PS alone. The results indicate that mealworms from diverse locations eat and metabolize PS and support the hypothesis that this capacity is independent of the geographic origin of the mealworms, and is likely ubiquitous to members of this species.


Assuntos
Bactérias/metabolismo , Biodegradação Ambiental , Besouros/metabolismo , Microbioma Gastrointestinal/fisiologia , Larva/metabolismo , Poliestirenos/metabolismo , Animais , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , China , Besouros/crescimento & desenvolvimento , Microbioma Gastrointestinal/efeitos dos fármacos , Gentamicinas/farmacologia , Larva/crescimento & desenvolvimento
16.
J Biomed Mater Res A ; 81(3): 634-43, 2007 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-17187390

RESUMO

This article discusses the unique material manufacturing process of self-propagating high temperature synthesis (SHS) as applied to the making of porous biomaterials. Porous materials have long been considered as the first step toward in-vivo bone tissue engineering and the creation of patient life-time implants. The authors have approached this challenge by utilizing combustion synthesis, to create novel materials such as NiTi + TiC as well as porous forms of materials that are commonly accepted for biomedical applications such as tricalcium phosphate and hydroxyapatite. In the SHS product, physico-chemical properties are controlled by, but not limited to, reactant stoichiometry; green density; particle size of the reactant mix; use or presence of a gasifying agent; heating rate of the reactants and gravity. By balancing these parameters, the energy of the reaction is controlled to create the desired product stoichiometry, porosity, and mechanical properties. SHS provides a means to rapidly manufacture materials, saving time and production costs as well as enabling the synthesis of custom devices through the use of individual molds. Mold materials can range from graphite to paper or paper machete. Combustion synthesis offers a method for the rapid manufacture of affordable, individual biomedical devices that will reduce patient recovery time.


Assuntos
Materiais Biocompatíveis/síntese química , Temperatura , Fenômenos Biomecânicos , Fosfatos de Cálcio , Gases , Gravitação , Porosidade , Titânio
17.
Food Chem Toxicol ; 45(11): 2219-27, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17624649

RESUMO

The flaxseed lignan secoisolariciresinol diglucoside (SDG) and mammalian lignans enterodiol (ED) and enterolactone (EL) were previously shown to be effective antioxidants against DNA damage and lipid peroxidation. Others reported inhibition of activated cell chemiluminescence by supra-physiological concentrations of secoisolariciresinol (SECO), ED and EL. Thus, we evaluated the antioxidant efficacy of potential physiological concentrations of SDG, SECO, ED and EL against 1,1-diphenyl-2-picrylhydrazyl (DPPH()), and 2,2'-azo-bis(2-amidinopropane) dihydrochloride (AAPH)-initiated peroxyl radical plasmid DNA damage and phosphatidylcholine liposome lipid peroxidation. SDG and SECO were effective (p<0.01) antioxidants against DPPH() at 25-200muM; whereas, ED and EL were inactive. Efficacy of lignans and controls against AAPH peroxyl radical-induced DNA damage was: SDG>SECO=17alpha-estradiol>ED=EL>genistein>daidzein. Lignan efficacy against AAPH-induced liposome lipid peroxidation was: SDG>SECO=ED=EL. Plant lignan antioxidant activity was attributed to the 3-methoxy-4-hydroxyl substituents of SDG and SECO, versus the meta mono-phenol structures of ED and EL. Benzylic hydrogen abstraction and potential resonance stabilization of phenoxyl radicals in an aqueous environment likely contributed to the antioxidant activity of the mammalian lignans. These represent likely extra- and intracellular antioxidant activities of flax-derived lignans at concentrations potentially achievable in vivo.


Assuntos
4-Butirolactona/análogos & derivados , Butileno Glicóis/química , Linho/química , Glucosídeos/química , Lignanas/química , 4-Butirolactona/química , Animais , Compostos de Bifenilo/química , Sequestradores de Radicais Livres/química , Hidrazinas/química , Lipossomos/química , Mamíferos , Estrutura Molecular , Picratos , Sementes
18.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 25(11): 1024-6, 2005 Nov.
Artigo em Zh | MEDLINE | ID: mdl-16355623

RESUMO

OBJECTIVE: To observe the clinical efficacy of drug toothpaste containing 2% Zanthoxylum Nitidum extract in reducing accumulation of dental plaque and occurrence of gingivitis in adults. METHODS: Adopting double-blind, stratified and parallel design, the status of dental plaque and gingivitis in 200 healthy adults enrolled in the trial (100 in the treated group took the drug toothpaste to clean teeth, and 100 in the control group use common toothpaste instead) were assessed at before experiment, 3 months and 6 months after experiment. RESULTS: At the end of the 3rd month and the 6th month, as compared with the control group, the L e-Silness Gingival Index (GI) in the treated group was decreased by 9.1% (P > 0.05) and 13.9 % (P< 0.5), in the same period, the Quigley-Hein(Turesky Modification) Plaque Index (PlI) decreased by 18.7% and 22.6% (P<0.05), respectively. CONCLUSION: Toothpaste containing Zanthoxylum Nitidum extract can obviously decrease the incidence of dental plaque and enhance gingival health.


Assuntos
Placa Dentária/tratamento farmacológico , Gengivite/tratamento farmacológico , Fitoterapia , Cremes Dentais/química , Zanthoxylum/química , Adolescente , Adulto , Idoso , Método Duplo-Cego , Medicamentos de Ervas Chinesas/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Bioresour Technol ; 192: 611-7, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26093255

RESUMO

Sewage sludge and bagasse were used as raw materials to produce cheap and efficient adsorbent with great adsorption capacity of Pb(2+). By pyrolysis at 800 °C for 0.5 h, the largest surface area (806.57 m(2)/g) of the adsorbent was obtained, enriched with organic functional groups. The optimal conditions for production of the adsorbent and adsorption of Pb(2+) were investigated. The results of adsorb-ability fitted the Langmuir isotherm and pseudo-second-order model well. The highest Pb(2+) (at pH = 4.0) adsorption capacity was achieved by treating with 60% (v/v) HNO3. This is a promising approach for metal removal from wastewater, as well as recycling sewage sludge and bagasse to ease their disposal pressure.


Assuntos
Celulose/química , Carvão Vegetal/química , Chumbo/isolamento & purificação , Saccharum/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Adsorção , Resíduos Industriais/prevenção & controle , Íons/isolamento & purificação , Chumbo/química , Esgotos/química , Ultrafiltração/métodos , Águas Residuárias , Poluentes Químicos da Água/química
20.
J Agric Food Chem ; 51(1): 301-10, 2003 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-12502425

RESUMO

This study was conducted to investigate the chemical antioxidant and bioactive properties of the water (WF) and ethyl acetate fractions (EAF) derived from dandelion (Taraxacum officinale) flower extract (DFE). HPLC analysis showed the presence of both luteolin and luteolin 7-glucoside in the DFE, which contributed to noted in vitro antioxidant and Caco-2 cell cytotoxic activities. Both WF and EAF of DFE exhibited free radical scavenging activities in a stable 2,2-diphenyl-1-picrylhydrazyl radical model and reduced the breakage of supercoiled DNA strand induced by both non-site-specific and site-specific hydroxyl radical. Oxidation of structured phosphatidylcholine liposome induced by peroxyl radical was reduced in the presence of both EAF and WF. EAF had greater (p < 0.05) affinity to scavenge peroxyl radical than WF, as measured by the formation of conjugated diene. At low concentration, prooxidant activity of both fractions was observed in Cu(2+)-induced structured liposome and hLDL oxidation models, thus indicating that the reducing power of the DFE had resulted in generation of reactive cuprous ion. However, at high concentrations the EAF did not promote oxidation in the presence of Cu(2+), suggesting that the free radical scavenging activity of this fraction was sufficient to minimize the potential oxidative mechanism attributed to the metal ion reducing activity associated with prooxidant activity.


Assuntos
Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Flores/química , Oxidantes/farmacologia , Extratos Vegetais/farmacologia , Taraxacum/química , Compostos de Bifenilo , Células CACO-2/patologia , Morte Celular/efeitos dos fármacos , Fracionamento Químico , Cromatografia Líquida de Alta Pressão , Cobre/farmacologia , Dano ao DNA , Flavonoides/análise , Sequestradores de Radicais Livres/farmacologia , Radicais Livres/farmacologia , Glucosídeos/análise , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Lipoproteínas LDL/química , Lipossomos/química , Luteolina , Fosfatidilcolinas/química , Picratos/química , Solventes
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