Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
1.
Int J Mol Sci ; 25(5)2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38474082

RESUMO

The removal of Cr(VI), a highly-toxic heavy metal, from industrial wastewater is a critical issue in water treatment research. Photocatalysis, a promising technology to solve the Cr(VI) pollution problem, requires urgent and continuous improvement to enhance its performance. To address this need, an electric field-assisted photocatalytic system (PCS) was proposed to meet the growing demand for industrial wastewater treatment. Firstly, we selected PAF-54, a nitrogen-rich porous organic polymer, as the PCS's catalytic material. PAF-54 exhibits a large adsorption capacity (189 mg/g) for Cr(VI) oxyanions through hydrogen bonding and electrostatic interaction. It was then coated on carbon paper (CP) and used as the photocatalytic electrode. The synergy between capacitive deionization (CDI) and photocatalysis significantly promotes the photoreduction of Cr(VI). The photocatalytic performance was enhanced due to the electric field's influence on the mass transfer process, which could strengthen the enrichment of Cr(VI) oxyanions and the repulsion of Cr(III) cations on the surface of PAF-54/CP electrode. In addition, the PCS system demonstrates excellent recyclability and stability, making it a promising candidate for chromium wastewater treatment.


Assuntos
Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Águas Residuárias , Cromo/análise , Adsorção , Cinética , Concentração de Íons de Hidrogênio
2.
Molecules ; 28(18)2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37764240

RESUMO

A composite film that features bismuth-antimony alloy nanoparticles uniformly embedded in a 3D hierarchical porous carbon skeleton is synthesized by the polyacrylonitrile-spreading method. The dissolved polystyrene is used as a soft template. The average diameter of the bismuth-antimony alloy nanoparticles is ~34.5 nm. The content of the Bi-Sb alloy has an impact on the electrochemical performance of the composite film. When the content of the bismuth-antimony alloy is 45.27%, the reversible capacity and cycling stability of the composite film are the best. Importantly, the composite film outperforms the bismuth-antimony alloy nanoparticles embedded in dense carbon film and the cube carbon nanobox in terms of specific capacity, cycling stability, and rate capability. The composite film can provide a discharge capacity of 322 mAh g-1 after 500 cycles at 0.5 A g-1, 292 mAh g-1 after 500 cycles at 1 A g-1, and 185 mAh g-1 after 2000 cycles at 10 A g-1. The carbon film prepared by the spreading method presents a unique integrated composite structure that significantly improves the structural stability and electronic conductivity of Bi-Sb alloy nanoparticles. The 3D hierarchical porous carbon skeleton structure further enhances electrolyte accessibility, promotes Na+ transport, increases reaction kinetics, and buffers internal stress.

3.
Phys Rev Lett ; 128(5): 052002, 2022 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-35179940

RESUMO

We present a combined analysis of the electromagnetic form factors of the nucleon in the space- and timelike regions using dispersion theory. Our framework provides a consistent description of the experimental data over the full range of momentum transfer, in line with the strictures from analyticity and unitarity. The statistical uncertainties of the extracted form factors are estimated using the bootstrap method, while systematic errors are determined from variations of the spectral functions. We also perform a high-precision extraction of the nucleon radii and find good agreement with previous analyses of spacelike data alone. For the proton charge radius, we find r_{E}^{p}=0.840_{-0.002}^{+0.003} _{-0.002}^{+0.002} fm, where the first error is statistical and the second one is systematic. The Zemach radius and third moment are in agreement with Lamb shift measurements and hyperfine splittings. The combined dataset of space- and timelike data disfavors a zero crossing of µ_{p}G_{E}^{p}/G_{M}^{p} in the spacelike region. Finally, we discuss the status and perspectives of modulus and phase of the form factors in the timelike region in the context of future experiments, as well as the onset of perturbative QCD.

4.
Bull Environ Contam Toxicol ; 101(5): 684-690, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30353306

RESUMO

Wheat (Triticum aestivum L.) has relatively high tolerance to cadmium (Cd), but the underlying mechanisms are poorly understood. Growth and physiological parameters of wheat exposed to different Cd concentrations (0, 0.5, 5 and 50 µM) were characterized. The fresh weight, leaf chlorophyll and carotenoid concentrations and photosynthesis parameters did not differ among Cd treatments, suggesting relatively high Cd tolerance in wheat. However, the soluble sugar concentrations increased with the increasing Cd concentration and the soluble protein concentrations decreased in both shoots and roots, suggesting that the Cd application promoted nitrogen metabolism over carbon metabolism. In addition, the higher concentrations of MDA, GSH and AsA and activities of antioxidant enzymes (SOD, POD, and CAT) were observed in leaves and roots in the Cd50 treatment. Our results reveal that wheat can tolerate Cd by enhancing the antioxidant enzymes activities and increasing the concentration of ascorbate and glutathione.


Assuntos
Antioxidantes/metabolismo , Cádmio/metabolismo , Glutationa/metabolismo , Triticum/metabolismo , Ácido Ascórbico/metabolismo , Catalase/metabolismo , Clorofila/metabolismo , Fotossíntese , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Superóxido Dismutase/metabolismo
5.
J Sep Sci ; 38(10): 1784-93, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25781863

RESUMO

An ultra high performance liquid chromatography with tandem mass spectrometry method was established for the rapid and simultaneous analysis of seven antiviral drugs, amantadine, rimantadine, memantine, moroxydine, imiquimod, oseltamivir, and acyclovir, in chicken liver, muscle, and egg. Homogenized samples were extracted with trichloroacetic acid and acetonitrile solutions and then purified by cation-exchange solid-phase extraction. The target drugs were analyzed by liquid chromatography with a UPLC BEH Amide column (2.1 mm × 100 mm, 1.7 µm) coupled with a tandem mass spectrometer operating in the positive multiple-reaction mode. A perfectly linear relationship was obtained within the concentration ranges of 0.5-20 µg/L for acyclovir and 0.1-10 µg/L for the other six antiviral drugs. The average recoveries of the seven antiviral drugs using four addition levels in chicken liver, muscle, and eggs were 82.67-90.10, 82.30-92.27, and 81.98-93.77%, respectively, and the acceptable coefficients of variation were 5.18-9.88, 4.84-11.2, and 42.8-9.95%, respectively. The detection limits and detection capabilities of the analysis method for the seven antiviral drugs were in the ranges of 0.04-0.64 and 0.11-0.78 µg/kg, respectively. Additionally, an inter-laboratory study among five laboratories further validated the method.


Assuntos
Antivirais/análise , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Animais , Galinhas , Reprodutibilidade dos Testes
6.
Sci Rep ; 14(1): 15082, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956184

RESUMO

Malaysia's excessive energy consumption has led to the depletion of traditional energy reserves such as oil and natural gas. Although Malaysia has implemented multiple policies to achieve sustainable national energy development, the current results are unsatisfactory. As of 2022, only 2% of the country's electricity supply comes from renewable energy, which accounts for less than 30% of the energy structure. Malaysia must ensure energy security and diversified energy supply while ensuring sustainable energy development. This article uses the fuzzy multi-criteria decision-making(MCDM) method based on cumulative prospect theory to help decision-makers choose the most suitable renewable energy for sustainable development in Malaysia from four dimensions of technology, economy, society, and environment. The results show that solar power is the most suitable renewable energy for sustainable development, followed by biomass, wind, and hydropower, but the optimal alternative is sensitive to the prospect parameters. Finally, it was analyzed that efficiency, payback period, employment creation, and carbon dioxide (CO2) emissions are the most critical factors affecting the development of renewable energy in Malaysia under the four dimensions. Reasonable suggestions are proposed from policy review, green finance, public awareness, engineering education, and future energy. This research provides insightful information that can help Malaysian decision-makers scientifically formulate Sustainable development paths for renewable energy, analyze the problems encountered in the current stage of renewable energy development, and provide recommendations for Malaysia's future renewable energy transition and sustainable development.

7.
Environ Pollut ; 350: 124011, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38641034

RESUMO

The clean and efficient utilization of municipal solid waste (MSW) has attracted increasing concerns in recent years. Pyrolysis of MSW is one of the promising options due to the production of high-value intermediates and the inhibition of pollutants at reducing atmosphere. Herein, the formation behavior of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) during MSW pyrolysis and incineration was experimentally investigated and compared. The influence of reaction temperature, CaO addition, and redox atmosphere on PCDD/Fs formation were compared and discussed. The results showed as the pyrolysis temperature increased, the mass concentration and international toxicity equivalence quantity of PCDD/Fs initially peaked at ∼750 °C before declining. Most of the generated PCDD/Fs were concentrated in the liquid and gaseous products, accounting for ∼90% of the total. Among liquid products, octachlorodibenzo-p-dioxin (O8CDD), 2,3,4,7,8-pentachlorodibenzofuran and 1,2,3,4,6,7,8-heptachlorodibenzofuran (H7CDF) were the most crucial mass concentration contributors, while in gas products, high-chlorinated PCDD/Fs, such as O8CDD, octachlorodibenzofuran (O8CDF) and 1,2,3,4,6,7,8-H7CDF were predominant. Compared to incineration, the formation of PCDD/Fs was 7-20 times greater than that from pyrolysis. This discrepancy can be attributed to the hydrogen-rich and oxygen-deficient atmosphere during pyrolysis, which effectively inhibited the Deacon reaction and the formation of C-Cl bonds, thereby reducing the active chlorine in the system. The addition of in-situ CaO additives also decreased the active chlorine content in the system, bolstering the inhibiting of PCDD/Fs formation during MSW pyrolysis.


Assuntos
Compostos de Cálcio , Incineração , Oxirredução , Óxidos , Dibenzodioxinas Policloradas , Pirólise , Dibenzodioxinas Policloradas/química , Dibenzodioxinas Policloradas/análise , Compostos de Cálcio/química , Óxidos/química , Dibenzofuranos Policlorados/química , Temperatura , Resíduos Sólidos , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/química , Benzofuranos/química
8.
Materials (Basel) ; 15(10)2022 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-35629605

RESUMO

Soda residue (SR), a solid waste generated in the production of Na2CO3 during the ammonia soda process, with a high pH value of 12, can be used as an activator of alkali-activated ground granulated blast furnace slag (GGBFS) cementitious materials. Three groups of experiments on SR-activated GGBFS mortars were designed in this paper to assess the role of the dominant parameters on fluidity and compressive strength of mortars. The results indicate that for fluidity and mechanical properties, the optimal scheme of SR-activated GGBFS mortars is 16:84-24:76 S/G, 0.01 NaOH/b, 0.05 CaO/b, and 0.50 w/b, with fluidity and compressive strength (28 d) of the mortars being 181-195 mm and 32.3-35.4 MPa, respectively. Between 2.5-10% CaCl2 addition to CaO (5%)-SR (24%)-activated GGBFS mortar is beneficial to the improvement of the compressive strength of C2, whereas the addition of CaSO4 is harmful. The main hydration products of mortars are ettringite, Friedel's slat, and CSH gels. The results provide a theoretical basis and data support for the utilization of SR.

9.
Stress Biol ; 2(1): 7, 2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-37676376

RESUMO

Conserved effectors produced by phytopathogens play critical roles in plant-microbe interactions. NIS1-like proteins represent a newly identified family of effectors distributed in multiple fungal species. However, their biological functions in a majority of pathogenic fungi remain largely elusive and require further investigation. In this study, we characterized two NIS1-like proteins VmNIS1 and VmNIS2 from Valsa mali, the causal agent of apple Valsa canker. Both of these two proteins were predicted to be secreted. Using agroinfiltration, we found that VmNIS1 induced intense cell death, whereas VmNIS2 suppressed INF1 elicitin-triggered cell death in Nicotiana benthamiana. Treatment of N. benthamiana with VmNIS1 recombinant protein produced by Escherichia coli activated a series of immune responses and enhanced plant disease resistance against Phytophthora capsici. In contrast, VmNIS2 suppressed plant immune responses and promoted P. capsici infection when transiently expressed in N. benthamiana. Both VmNIS1 and VmNIS2 were shown to be highly induced at late stage of V. mali infection. By individually knocking out of these two genes in V. mali, however, only VmNIS2 was shown to be required for pathogen virulence as well as tolerance to oxidative stress. Notably, we further showed that C-terminal extension of VmNIS1 was essential for plant recognition and VmNIS2 may escape plant detection via sequence truncation. Our data collectively indicate that VmNIS1 and VmNIS2 play distinct roles in plant recognition and pathogen virulence, which provided new insights into the function of NIS1-like proteins in plant-microbe interactions.

10.
Environ Sci Pollut Res Int ; 29(12): 17919-17931, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34677766

RESUMO

Algae play an important role in ecological processes of aquatic ecosystems. Understanding the interactive effects of algae with invertebrates in litter decomposition is important for predicting the effects of global change on aquatic ecosystems. We manipulated Typha angustifolia litter to control exposure to shrimp fecal pellets and/or grazing, and the green alga Chlorella vulgaris were added to test their interactive effects on T. angustifolia litter decomposition. Our results showed that algae largely shortened microbial conditioning time and improved litter palatability (increasing litter quality), resulting in greater decomposition and higher fecal pellet production. Fecal pellets enhanced grazing effects on decomposition by increasing litter ash content. The effects of algae and especially fecal pellets on decomposition were dependent on or mediated by grazing. Without grazing, algae slightly promoted decomposition and marginally offset the negative effect of fecal pellets on litter decomposition. Shrimp grazing dramatically decreased microbial activity (extracellular enzyme activity and microbial respiration) at microbial conditioning stage while enhanced microbial activity after 84 days especially with both algae and fecal pellets present. Algae significantly upregulated N- and P-acquiring and slightly downregulated C-acquiring enzyme activity. Fecal pellets significantly depressed recalcitrant C-decomposition enzyme activity. Nevertheless, the three factors synergistically and significantly increased C loss and most enzyme activities, microbial respiration, and N immobilization, resulting in the decrease of litter C:N. Our results reveal the synergistic action of different trophic levels (autotrophs, heterotrophs, and primary consumers) in the complicated nutrient pathways of litter decomposition and provide support for predicting the effects of global changes (e.g., N deposition and CO2 enrichment), which have dramatically effects on alga dynamics and on ecological processes in aquatic ecosystems.


Assuntos
Chlorella vulgaris , Typhaceae , Chlorella vulgaris/metabolismo , Ecossistema , Nitrogênio/metabolismo , Folhas de Planta/metabolismo , Plantas/metabolismo , Typhaceae/metabolismo
11.
Electrophoresis ; 32(6-7): 659-64, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21328395

RESUMO

A method for the determination of methylene blue (MB) and its metabolites (azure A, azure B and azure C) in rat blood by CE-electrospray ionization mass spectrometry (CE-ESI-MS) was developed in this paper. Different analytical parameters were investigated in detail such as pH and concentration of separation buffer, and ESI-MS instrumental parameters. Under the optimum conditions, MB and its metabolites were separated and detected in 27.3 min. LODs (defined as S/N=3) of this method were 0.22, 0.25, 0.10 and 0.30 µg/mL for MB, azure A, azure B and azure C, respectively. To get a satisfactory extraction efficiency of MB and its metabolites in rat blood, different extraction solutions were studied. By using this method, MB and its metabolites (azure A, azure B and azure C) were successfully analyzed in rat blood samples.


Assuntos
Análise Química do Sangue , Eletroforese Capilar/métodos , Azul de Metileno/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Animais , Concentração de Íons de Hidrogênio , Azul de Metileno/metabolismo , Camundongos , Ratos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
J Environ Sci (China) ; 23(12): 2055-62, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22432338

RESUMO

A biosorbent prepared from powdered mycelial biomass of Ceriporia lacerata (CLB), a basidiomycetous fungus, was applied for the uptake of Crystal Violet from aqueous solution. A batch adsorption experiment was used for the biosorption process, involving effect of experimental factors and biosorption kinetics and equilibrium. Biosorption process showed that the removal of Crystal Violet by CLB was effective over wide pH range, and meanwhile was independent on ionic strength. Biosorption capacities of CLB increased with the initial dye concentration increasing, due to an increase in the driving force of the concentration gradient. The adsorbed Crystal Violet amount per unit biomass weight decreased with increasing biosorbent dosage, due to the splitting effect of flux (concentration gradient) between sorbate and biosorbent. A maximum sorption capacity of 239.25 mg/g was observed. Biosorption kinetics was found to be best represented by the pseudo second-order kinetic model. The equilibrium adsorption data was well described by the Koble-Corrigan model. FT-IR (Fourier Transform Infrared Spetroscopy) spectrum showed the presence of O-H, COOH, C=O, C-N, C-H, -NH2 and P-OH in the surface of CLB as functional groups. This study showed CLB can effectively remove CV from dye wastewater.


Assuntos
Basidiomycota/química , Violeta Genciana/química , Poluentes Químicos da Água/química , Adsorção , Biomassa , Corantes/química , Concentração de Íons de Hidrogênio , Cinética , Concentração Osmolar , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Materials (Basel) ; 14(11)2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34072143

RESUMO

Soda residue (SR), an industrial solid waste, pollutes the environment due to its high alkalinity and chloride ion content. SR can be used as an alkali activator of ground granulated blast furnace slag (GGBFS). This study investigated the effects of four types of SR-activated GGBFS cementitious materials (pastes) with different mass ratios of SR to GGBFS (8:92, 16:84, 24:76, 34:68) on the physical properties, mechanical strength, and chloride binding capacity. The hydration mechanism of the pastes was also studied. Results showed that with the increasing addition of SR, the density of the pastes decreased, and more white aggregates of SR appeared causing the increase of water absorption and porosity of the pastes. The pastes with 16% SR addition had the maximum compressive strength (34.1 MPa, 28 d), so the optimum proportion of SR addition in the pastes was 16%. With the increases of SR addition, the amount of chloride element in the initial pastes increases. When the proportion of SR addition is 8%, the mass percentage of free chloride ion in the pastes at 28 d is 0.13%. The main hydration products of the pastes were C-S-H gels, ettringite, and Friedel's salt, and the amount of ettringite varied with the amount of SR addition and curing time.

14.
Materials (Basel) ; 14(4)2021 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-33562326

RESUMO

The early mechanical performances of low-calcium fly ash (FFA)-based geopolymer (FFA-GEO) mortar can be enhanced by soda residue (SR). However, the resistance of SR-FFA-GEO mortar to acid or sulfate environments is unclear, owing to the various inorganic calcium salts in SR. The aim of this study was to investigate the long-term mechanical strengths of up to 360 d and evaluate the resistance of SR-FFA-GEO mortar to 5% HCl and 5% Na2SO4 environments through the losses in compressive strength and mass. Scanning Electron Microscopy (SEM), Energy-Dispersive Spectroscopy (EDS) and Fourier Transform Infrared Spectrometer (FTIR) experiments were conducted for the SR-FFA-GEO mortars, both before and after chemical attack, to clarify the attack mechanism. The results show that the resistances of the SR-FFA-GEO mortar with 20% SR (namely M10) to 5% HCl and 5% Na2SO4 environments are superior to those of cement mortar. The environmental HCl reacts with the calcites in SR to produce CaCl2, CO2 and H2O to form more pores under HCl attack, and the environmental Na+ cations from Na2SO4 go into Si-O-Al network structure, to further enhance the strength of mortar under Na2SO4 attack. These results provide the experimental basis for the durability optimization of SR-FFA-GEO mortars.

15.
Materials (Basel) ; 13(7)2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-32290192

RESUMO

Soda residue (SR), the solid waste of Na2CO3 produced by ammonia soda process, pollutes water and soil, increasing environmental pressure. SR has high alkalinity, and its main components are Ca(OH)2, NaCl, CaCl2, CaSO4, and CaCO3, which accords with the requirements of being an alkali activator. The aim of this research is to investigate the best proportion of SR addition and the contribution of individual chemical components in SR to SR- activated ground granulated blast furnace slag (GGBS) cementitious materials. In this paper, GGBS pastes activated by SR, Ca(OH)2, Ca(OH)2 + NaCl, Ca(OH)2 + CaCl2, Ca(OH)2 + CaSO4, and Ca(OH)2 + CaCO3 were studied regarding setting time, compressive strength (1 d, 3 d, 7 d, 14 d, 28 d), hydration products, and microstructure. The results demonstrate that SR (24%)-activated GGBS pastes possess acceptable setting time and compressive strength (29.6 MPa, 28 d), and its hydration products are calcium silicate hydrate (CSH) gel, calcium aluminum silicate hydrates (CASH) gel and Friedel's salt. CaCl2 in SR plays a main role in hydration products generation and high compressive strength of SR- activated GGBS pastes.

16.
AMB Express ; 10(1): 178, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33006679

RESUMO

Laccases are a class of multi-copper oxidases with important industrial values. A thermotolerant laccase produced by a basidiomycete fungal strain Cerrena unicolor CGMCC 5.1011 was studied. With glycerin and peptone as the carbon and nitrogen sources, respectively, a maximal laccase activity of 121.7 U/mL was attained after cultivation in the shaking flask for 15 days. Transcriptomics analysis revealed an expressed laccase gene family of 12 members in C. unicolor strain CGMCC 5.1011, and the gene and cDNA sequences were cloned. A glycosylated laccase was purified from the fermentation broth of Cerrena unicolor CGMCC 5.1011 and corresponded to Lac2 based on MALDI-TOF MS/MS identification. Lac2 was stable at pH 5.0 and above, and was resistant to organic solvents. Lac2 displayed remarkable thermostability, with half-life time of 1.67 h at 70 ºC. Consistently, Lac2 was able to completely decolorize malachite green (MG) at high temperatures, whereas Lac7 from Cerrena sp. HYB07 resulted in accumulation of colored MG transformation intermediates. Molecular dynamics simulation of Lac2 was conducted, and possible mechanisms underlying Lac2 thermostability were discussed. The robustness of C. unicolor CGMCC 5.1011 laccase would not only be useful for industrial applications, but also provide a template for future work to develop thermostable laccases.

17.
Materials (Basel) ; 13(24)2020 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-33302554

RESUMO

Solid waste soda residue (SR), as an industrial pollutant of water, air and soil environment, can be utilized to prepare the low-calcium fly ash (FFA)-based geopolymer paste activated by sodium silicate (NS) solution for goaf backfill. However, the high addition of NS produces the high cost and high strength of synthesized backfill material in the previous study. The objective of this research is to investigate the cost optimization method and performance evaluation of SR-FFA-based geopolymer backfill paste. The alkaline beta-hemihydrate gypsum (BHG) alternative to partial NS was proposed. Scanning electron microscopy (SEM), X-ray diffraction (XRD) as well as Fourier transform infrared spectrometer (FTIR) tests were performed to clarify the role of BHG and evaluate the microstructures and products of backfill pastes. The results show that 10% BHG alternative ratios effectively improve fluidity, setting time and compressive strength to satisfy the performance requirement of goaf backfill material. The gel products in the optimal backfill paste C4 with 10% BHG alternative ratios are determined as the coexistence of C-S-H gel, (N,C)-A-S-H gel and CaSO4·2H2O at 28 d. The research results can make extensive utilization of SR and FFA in cemented paste backfill to synthesize cleaner material at a larger scale.

18.
J Biomater Sci Polym Ed ; 31(6): 695-711, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31914358

RESUMO

Developing the hybrid nanosystems for controlled drug release is still a challenging task. In this work, pH-responsive core-shell nanocomposites have been prepared by the growth of zeolitic imidazolate framework-8 (ZIF-8) on the surface of polymeric aggregates self-assembled from poly(ε-caprolactone)-block-poly (quaternized vinylbenzyl chloride/bipyridine) (PCL-b-q(PVBC/BPy), BCP for short) in water. The core of the micelles or the inner cavity of vesicles serves as the drug storage reservoir for the doxorubicin hydrochloride (DOX) and the ZIF-8 shells act as the gatekeepers to prevent drug premature release at physiological environment. Upon pH stimulus, the core-shell nanocomposites (BCP@ZIF-8) show a retarded drug release behavior compared with DOX-loaded polymeric aggregates counterparts (without the shell of ZIF-8). Moreover, the as-prepared nanocomposites perform good biocompatibility towards MCF-7 cell. Meanwhile, the DOX-loaded BCP@ZIF-8 nanocomposites present lower cytotoxicity compared with DOX-loaded BCP and free DOX. The confocal microscopy study shows the core-shell nanocomposites could be efficiently internalized by cancer cells, and the loaded DOX could be successfully released under acidic intracellular environment. The above result shows that the core-shell nanocomposite could be a promising candidate for pH-responsive drug delivery system in the cancer therapy.


Assuntos
Portadores de Fármacos/química , Imidazóis/química , Estruturas Metalorgânicas/química , Nanocompostos/química , Polímeros/química , Preparações de Ação Retardada , Doxorrubicina/química , Portadores de Fármacos/toxicidade , Humanos , Concentração de Íons de Hidrogênio , Células MCF-7 , Micelas , Nanocompostos/toxicidade , Água/química
19.
ACS Appl Bio Mater ; 3(9): 6376-6383, 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-35021768

RESUMO

Smart insulin delivery platforms having the ability of mimicking pancreatic cells are highly expected for diabetes treatment. Herein, a smart glucose-sensitive insulin delivery platform on the basis of transcutaneous microneedles has been designed. The as-prepared microneedles are composed of glucose- and pH-responsive supramolecular polymer vesicles (PVs) as the drug storage and water soluble polymers as the matrix. The well-defined PVs are constructed from the host-guest inclusion complex between water-soluble pillar[5]arene (WP5) with pH-responsiveness and paraquat-ended poly(phenylboronic acid) (PPBA-G) with glucose-sensitivity. The drug-loaded PVs, including insulin and glucose oxidase (GOx) can quickly respond to elevated glucose level, accompanied by the disassociation of PVs and fast release of encapsulated insulin. Moreover, the insulin release rate is further accelerated by GOx, which generates gluconic acid at high glucose levels, thus decreasing the local pH. Therefore, the host-guest interaction between WP5 and PPBA-G is destroyed and a total structure disassociation of PVs takes place, contributing to a fast release of encapsulated insulin. The in vivo insulin delivery to diabetic rats displays a quick response to hyperglycemic levels and then can fast regulate the blood glucose concentrations to normal levels, which demonstrates that the obtained smart insulin device has a highly potential application in the treatment of diabetes.

20.
Sci Bull (Beijing) ; 69(4): 419-421, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38171963
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA