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1.
J Int Med Res ; 51(7): 3000605231187819, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37480276

RESUMO

Resin components, such as methyl methacrylate (MMA) can cause allergic contact dermatitis (ACD). Allergic reactions to resin are usually delayed. Only a few studies have reported dental resin allergy with acute symptoms. Here, a case of ACD with acute facial swelling after dental treatment using resin material is reported. A 55-year-old woman with a history of periungual inflammation when using gel nail polish had repeated episodes of facial swelling after dental treatment with resin material. The resin temporary crown was removed, and symptoms were alleviated with antihistamines and corticosteroids. With the suspicion of resin allergy, skin tests were performed. Patch testing revealed positive reactions to self-adhesive resin cement (primer and polymerized), self-curing acrylic resin (liquid and polymerized), 2-hydroxyethyl methacrylate (2-HEMA), and ethylene glycol dimethacrylate (EGDMA), whereas the prick test was negative for all allergens. Complement C4 and C1 inhibitor activity were reference values in the tests for hereditary angioedema. Based on these findings, the patient was diagnosed with ACD to 2-HEMA and EGDMA. Since diagnosis, no similar symptoms have been observed in subsequent dental treatment with non-resin materials. The use of dental resin materials may cause ACD with an acute reaction. This report alerts dentists who routinely use resin materials.


Assuntos
Hipersensibilidade , Feminino , Humanos , Pessoa de Meia-Idade , Metacrilatos/efeitos adversos , Inflamação , Resinas Acrílicas/efeitos adversos
2.
Talanta ; 264: 124752, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37276675

RESUMO

Phytocannabinoids and their synthetic analogs (natural and synthetic cannabinoids) are illicit drugs that are widely abused worldwide. Wastewater-based epidemiology (WBE) is an objective approach for the estimation of population-level exposure to a wide range of substances, especially drugs of abuse. However, the concentrations of cannabinoids in wastewater are extremely low (frequently at the levels of nanograms per liter), and the existing pretreatment procedures for wastewater have the disadvantages of time-consumption or low extraction recoveries. This study aimed to propose a novel poly (methacrylic acid-co-ethylene glycol dimethacrylate)-functionalized polydopamine-coated Fe3O4 nanoparticle (Fe3O4@PDA@poly (MAA-co-EGDMA)) as an adsorbent, and provide a highly sensitive quantitative analytical technique for the detection of five synthetic cannabinoids (SCs: 5 F-EDMB-PINACA, FUB-APINACA, MDMB-4en-PINACA, MDMB-FUBINACA, and PB-22) and one cannabis-related human metabolite (THC-COOH) in wastewater. The magnetic adsorbents were fully characterized by transmission electron microscopy (TEM), infrared spectroscopy (IR), vibrating sample magnetometry (VSM) and X-ray photoelectron spectroscopy (XPS). Subsequently, an MSPE-UHPLC-MS/MS method was developed and validated for the determination of six trace analytes in wastewater. The validation results showed that the method has limits of quantification as low as 0.1-1.0 ng/L. Additionally, the recoveries ranged from 62.81 to 124.02%, and the relative standard deviations (RSDs) of intraday and interday precision were less than 15%. This MSPE-UHPLC-MS/MS method was successfully applied to real wastewater samples, and the whole analytical process of one sample from pretreatment to the obtained quantitative results was completed in less than 30 min. Thus, the proposed method based on Fe3O4@PDA@poly (MAA-co-EGDMA) is a convenient, rapid, sensitive and reliable method for the determination of trace psychoactive drugs in wastewater.


Assuntos
Canabinoides , Espectrometria de Massas em Tandem , Humanos , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/métodos , Águas Residuárias , Extração em Fase Sólida/métodos , Fenômenos Magnéticos
3.
Polymers (Basel) ; 15(5)2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36904488

RESUMO

Water scarcity and the loss of fertilizer from agricultural soils through runoff, which also leads to contamination of other areas, are increasingly common problems in agriculture. To mitigate nitrate water pollution, the technology of controlled release formulations (CRFs) provides a promising alternative for improving the management of nutrient supply and decreasing environmental pollution while maintaining good quality and high crop yields. This study describes the influence of pH and crosslinking agent, ethylene glycol dimethacrylate (EGDMA) or N,N'-methylenebis (acrylamide) (NMBA), on the behavior of polymeric materials in swelling and nitrate release kinetics. The characterization of hydrogels and CRFs was performed by FTIR, SEM, and swelling properties. Kinetic results were adjusted to Fick, Schott, and a novel equation proposed by the authors. Fixed-bed experiments were carried out by using the NMBA systems, coconut fiber, and commercial KNO3. Results showed that on the one hand, no significant differences were observed in nitrate release kinetics for any system in the selected pH range, this fact allowing to apply these hydrogels to any type of soil. On the other hand, nitrate release from SLC-NMBA was found to be a slower and longer process versus commercial potassium nitrate. These features indicate that the NMBA polymeric system could potentially be applied as a controlled release fertilizer suitable for a wide variety of soil typologies.

4.
Polymers (Basel) ; 16(1)2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38201758

RESUMO

Traditional wood-polymer composite (WPC) based on the in situ polymerization of ethylene unsaturated monomers in the cellular cavity of wood is significant for the high-value-added utilization of low-quality wood. However, this type of WPC has the problems of volatile monomers, low conversion rates, odor residue, and poor compatibility between the polymer and wood interface, which hinder its promotion and application. In this study, a two-step process of cell wall bulking in combination with cell lumen filling was prepared to modify wood using Maleic anhydride (MAN) as the bulking agent and GMA-EGDMA (molar ratio 2:1) as the active monomer system. The results indicate that the modulus of rupture (MOR) (125.19 ± 8.41 MPa), compressive strength (116.38 ± 7.69 MPa), impact toughness (55.4 ± 2.95 KJ m-2), and hardness (6187 ± 273 N) of the bulking-filling wood composite materials were improved by 54%, 56%, 36%, and 66%, respectively, compared with those of poplar wood. These properties were superior to those of the traditional styrene (PSt)-WPC and even exceeded the performance of Xylosma congesta (Lour.) Merr, a high-quality wood from northeast China. Meanwhile, the mass loss of wood composite materials with bulking-filling treatment was only 2.35 ± 0.05%, and the internal structure remained intact, presenting excellent decay resistance. Additionally, the treatment also significantly improved the thermal and dimensional stability of the wood composites. This study provides a theoretical basis and guidance for realizing the high-value-added application of low-quality wood and the preparation of highly durable wood-based composites.

5.
Environ Technol ; 43(14): 2155-2166, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33357094

RESUMO

Post treatment is a very competent and scalable approach to develop the higher water-flux and salt-rejection membrane since it does not require any change in existing manufacturing process. The virgin Thin Film Composite Reverse Osmosis (TFC-RO) membrane was exposed to various concentrations of Poly (ethylene Glycol) diacrylate (PEGDA) and Ethylene glycol dimethacrylate (EGDMA) after activation with sodium hypochlorite for 1 h. Crosslinkers modified membranes were characterized for degree of wettability by contact angle analyses, surface morphology and surface roughness study by Scanning electron micrographs and Atomic force micrographs, chemical structural modifications by Attenuated total reflectance Fourier transform Infrared spectroscopy. These treatments resulted in improved membrane performance. 3500 mg/l PEGDA-treated membrane permeate flux increased by 48.7% and salt-rejection by 3.43%. 2000 mg/l EGDMA treated membrane demonstrated 46.13% increase in water-flux and 3.08% increase in salt-rejection as compared with virgin membrane. Organic fouling study indicated that fouling in PEGDA-treated membrane was significantly lower than virgin membrane. Heavy metal ion removal performances for Zinc and Chromium were also higher for modified membranes. Thus, the surface modification by crosslinkers led to increase in selectivity for certain metal ions and better antifouling performance as compared to virgin membrane.


Assuntos
Incrustação Biológica , Purificação da Água , Incrustação Biológica/prevenção & controle , Membranas Artificiais , Osmose , Água
6.
Heliyon ; 7(2): e06234, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33665419

RESUMO

Prosthetic eyes are currently manufactured using Poly(methyl methacrylate) (PMMA) which is not an ideal material because it is hydrophobic. While significant research has investigated the benefits of hydrophilic materials for contact lenses, no such research has been carried out on hydrophilic materials for prosthetic eyes until now. In this study, different derivatives of Poly(ethylene glycol) (PEG) monomer and methyl methacrylate (MMA) monomer were grafted to PMMA using copolymerisation. The resulting matrixes were evaluated by water contact angle measurement, 24 h water absorption testing, and colour-difference measurement when exposed to ultraviolet light. The contact angle and water absorption results indicated that ethylene glycol dimethacrylate (EGDMA) grafted PMMA matrix had a better hydrophilic performance than the other matrixes tested. EGDMA is already a minor constituent of the PMMA matrix currently used for manufacturing prosthetic eyes but when the proportion of EGDMA monomer to MMA monomer used in the manufacturing process was increased to 50/50 the hydrophilicity of the matrix was significantly improved. EGDMA-grafted PMMA is inexpensive and comes as a liquid monomer that is easily mixed with the PMMA monomer that ocular prosthetists are familiar with. The mixture requires no special handling beyond the normal safety precautions that apply when using PMMA monomers. In-vitro testing shows that EGDMA-grafted PMMA significantly improves the wettability of PMMA currently used for the manufacture of prosthetic eyes and has the potential to significantly improve wearing comfort and socket health.

7.
Materials (Basel) ; 13(7)2020 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-32283784

RESUMO

This paper deals with the synthesis and studies of new polymer microspheres properties based on ethylene glycol dimethylacrylate (EGDMA), styrene (St), and various quantities of commercial kraft lignin (L). In the first stage of the investigations, the conditions of the synthesis process were optimized by selecting a proper amount of poly (vinyl alcohol), which was a suspension stabilizer. Next, based on EGDMA + St + L, new polymers were synthesized by the suspension polymerization method. The chemical structure of the materials was confirmed by means of the Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) analysis. The evaluation of the synthesized materials includes susceptibility to swelling in solvents of different character (polar and nonpolar), porous structure of microspheres, and their thermal resistance. Morphology has been specified by the scanning electron microscope and automated particle size, as well as shape analyzer. The obtained pictures confirmed the spherical shape of the materials. The microspheres porosity was characterized using the low-temperature nitrogen adsorption. To increase the porosity (partially blocked by the large lignin molecule), the microspheres (EGDMA + St + 4L copolymer) were impregnated with the aqueous solution of the activating substance (sulphuric acid, nitric acid, phosphorous acid, and silver nitrate) and then carbonized at 400 °C. After the carbonization process, the increase in the specific surface area was observed. The microspheres were porous with a specific surface area up to 300 m2/g. The materials had a desirable feature for their potential use in chromatography, which was confirmed by the results of GC analysis with the acetylsalicylic acid. These materials are an interesting alternative in the field of more environmentally friendly, ecological, and biodegradable polymeric sorbents in comparison to the commonly applied styrene-divinylbenzene (St-DVB) copolymers.

8.
Anal Bioanal Chem ; 412(8): 1825-1833, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32002581

RESUMO

A selective cortisol sensor based on molecularly imprinted poly(glycidylmethacrylate-co ethylene glycol dimethacrylate) (poly(GMA-co-EGDMA)) has been demonstrated for detection of cortisol in human sweat. The non-enzymatic biomimetric flexible sweat sensor was fabricated inexpensively by layer by layer (LbL) assembly. The sensor layers comprised a stretchable polydimethylsiloxane (PDMS) base with carbon nanotubes-cellulose nanocrystals (CNC/CNT) conductive nanoporous nanofilms. The imprinted (MIP) poly(GMA-co-EGDMA) deposited on the CNC/CNT was the cortisol biomimetric receptor. Rapid in analyte response (3 min), the cortisol MIP sensor demonstrated excellent performance. The sensor has a limit of detection (LOD) of 2.0 ng/mL ± 0.4 ng/mL, dynamic range of 10-66 ng/mL, and a sensor reproducibility of 2.6% relative standard deviation (RSD). The MIP sensor also had high cortisol specificity and was inherently blind to selected interfering species including glucose, epinephrine, ß-estradiol, and methoxyprogestrone. The MIP was four orders of magnitude more sensitive than its non-imprinted (NIP) counterpart. The MIP sensor remains stable over time, responding proportionately to doses of cortisol in human sweat. Graphical abstract.


Assuntos
Técnicas Eletroquímicas/instrumentação , Eletrodos , Hidrocortisona/análise , Impressão Molecular , Suor/química , Humanos , Limite de Detecção , Reprodutibilidade dos Testes , Dispositivos Eletrônicos Vestíveis
9.
Jpn Dent Sci Rev ; 55(1): 126-138, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31687052

RESUMO

This review article compiles the characteristics of resin based dental composites and an effort is made to point out their future perspectives. Recent research studies along with few earlier articles were studied to compile the synthesis schemes of commonly used monomers, their characteristics in terms of their physical, mechanical and polymerization process with selectivity towards the input parameters of polymerization process. This review covers surface modification processes of various filler particles using silanes, wear behaviour, antimicrobial behaviour along with its testing procedures to develop the fundamental knowledge of various characteristics of resin based composites. In the end of this review, possible areas of further interests are pointed out on the basis of literature review on resin based dental materials.

10.
Food Chem ; 265: 159-164, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-29884367

RESUMO

Ochratoxin A (OTA) is a mycotoxin produced by filamentous-type fungi that contaminates a wide variety of foods and beverages such as wines. In these trials, we evaluated the capacity of the following polymers for the removal of OTA from acidic model solutions and red wine: polyvinylpolypyrrolidone (PVPP), resin of N-vinyl-2-pyrrolidinone with ethylene glycol dimethacrylate and triallyl isocyanurate (PVP-DEGMA-TAIC), and poly(acrylamide-co-ethylene glycol-dimethacrylate) (PA-EGDMA). In acidic model solution, PVP-DEGMA-TAIC and PA-EGDMA polymers removed up to 99.9% of OTA, but their trapping capacity was highly reduced by the presence of competing phenolic substances (i.e. gallic acid and 4-methylcathecol). In real red wine, PA-EGDMA polymer showed the most promising results, with more than 68.0% OTA removal and less than 14.0% reduction in total phenolic. Finally, computational chemistry analyses showed that the affinity between OTA and the polymers studied would be due to Van der Waals interactions.


Assuntos
Ocratoxinas/isolamento & purificação , Polímeros/química , Vinho , Resinas Acrílicas/química , Contaminação de Alimentos , Metacrilatos/química , Modelos Químicos , Fenóis/química , Povidona/análogos & derivados , Povidona/química , Vinho/análise
11.
Carbohydr Polym ; 185: 169-178, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29421054

RESUMO

The novel hydrogels were synthesized by grafting guar gum with acrylic acid and cross-linking with ethylene glycol di methacrylic acid (EGDMA). The synthesis of hydrogel was confirmed by characterization through 13C NMR, FTIR spectroscopy, SEM micrography, thermo-gravimetric analysis and water absorption studies under different solutions. Synthesized hydrogel (GG-AA-EGDMA) was confirmed to be biodegradable with half-life period of 77 days through soil burial biodegradation studies. The effects of hydrogel treatment on soil were evaluated by studying various physico-chemical properties of soil like bulk density, porosity, water absorption and retention capacity etc. The hydrogel which could absorb up to 800 ml water per gram, after addition to soil, improved its porosity, moisture absorption and retention capacity significantly. Water holding capacity of water increased up to 54% of its original and porosity also increased up to 9% of its original. The synthesized hydrogel revealed tremendous potential as soil conditioning material for agricultural applications.

12.
J Chromatogr A ; 1524: 57-65, 2017 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-29017722

RESUMO

In this work, zeolitic imidazolate framework-8 (ZIF-8)/poly (methyl methacrylate-ethyleneglycol dimethacrylate) (MMA-EGDMA) composite monolith was in situ synthesized on stir bar by one-pot polymerization. Compared with the neat monolith, ZIF-8/poly(MMA-EGDMA) composite monolith has larger surface area and pore volume. It also exhibits higher extraction efficiency for target phytohormones than poly(MMA-EGDMA) monolith and commercial polyethylene glycol (PEG) coated stir bar. Based on it, a method of ZIF-8/poly(MMA-EGDMA) monolith coated stir bar sorptive extraction (SBSE)-high performance liquid chromatography-ultraviolet detection (HPLC-UV) was established for the analysis of five phytohormones in apple and pear samples. The developed method exhibited low limits of detection (0.11-0.51µg/L), wide linear range (0.5-500µg/L) and good recoveries (82.7-111%), which demonstrated good application potential of the ZIF-8/monolith coated stir bar in trace analysis of organic compounds.


Assuntos
Análise de Alimentos/métodos , Frutas/química , Reguladores de Crescimento de Plantas/análise , Reguladores de Crescimento de Plantas/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Extração Líquido-Líquido , Malus/química , Metacrilatos/química , Pyrus/química , Reprodutibilidade dos Testes , Raios Ultravioleta , Zeolitas/química
13.
Beilstein J Nanotechnol ; 8: 933-942, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28546888

RESUMO

In this study, the thermal, chemical and structural stability of 1H,1H,2H,2H-perfluorodecyl acrylate polymers (p-PFDA) synthetized by initiated chemical vapor deposition (iCVD) were investigated. PFDA polymers are known for their interesting crystalline aggregation into a lamellar structure that induces super-hydrophobicity and oleophobicity. Nevertheless, when considering applications which involve chemical, mechanical and thermal stresses, it is important to know the limits under which the crystalline aggregation and the resulting polymer properties are stable. For this, chemical, morphological and structural properties upon multiple heating/cooling cycles were investigated both for linear PFDA polymers and for differently strong cross-linked alterations thereof. Heat treatment leaves the chemical composition of the linear PFDA polymers largely unchanged, while a more ordered crystalline structure with smoother morphology is observed. At the same time, the hydrophobicity and the integrity of the polymer deteriorate upon heating. The integrity and hydrophobicity of cross-linked p-PFDA films was preserved likely because of the lack of internal strain due to the coexistence of both crystalline and amorphous phases. The possibility to finely tune the degree of cross-linking can therefore expand the application portfolio in which PFDA polymers can be utilized.

14.
Carbohydr Polym ; 166: 183-194, 2017 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-28385222

RESUMO

A new natural and synthetic polymeric blend to form interpenetrating polymer network (IPN) hydrogels was synthesized utilizing sodium alginate and PVA as polymers by free radical polymerization employing 2-Acylamido-2-methylpropane-sulfonic acid as monomer (AMPS) and tramadol HCl as model drug through 32 level full factorial design to evaluate the impact of selected independent factors i.e. polymer (sodium alginate) and monomer (AMPS) contents on swelling index at 18th hour, percent drug release at 18th hour, time required for 80% drug release and drug entrapment efficiency as dependent variables. FTIR, SEM, sol-gel analysis, equilibrium swelling studies and in-vitro release kinetics were performedfor in-vitro characterization of formulated IPN hydrogels. In-vitro studies carried out at pH 1.2 and pH 7.4 revealed pH independent swelling and drug release from polymeric IPN, providing controlled drug release for an extended period of time with improved entrapment efficiency, thereby concluding that this polymeric blend may be a promising system for the prolonged drug delivery.


Assuntos
Alginatos/química , Preparações de Ação Retardada/química , Hidrogéis , Álcool de Polivinil/química , Ácidos Hexurônicos , Concentração de Íons de Hidrogênio , Polímeros
15.
Int J Pharm ; 525(1): 226-236, 2017 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-28412447

RESUMO

Drug nanosuspensions (NSs) show a significant potential to improve loading and release properties of the poorly water soluble drug triamcinolone acetonide (TA) from poly(hydroxyethyl methacrylate) (pHEMA) soft contact lenses. In this work, TA NSs were developed by a controlled precipitation method using a fractional factorial Plackett-Burmann design. Poloxamer 407 (PL) and polyvinyl alcohol (PVA) as stabilizing agents were selected. NSs were characterized in terms of their drug content, particle size and morphology. Results indicate that all studied factors, except homogenization speed and sonication, have significant influence on the drug incorporation yield into NSs. Drug nanoparticles showed an interesting size that may be suitable for their incorporation into topical ocular drug delivery systems, as hydrogels. pHEMA hydrogels and daily-wear Hilafilcon B commercial contact lenses (SCLs) were employed to study TA loading capacity and drug release properties using NSs as loading system. Hydrogels have been synthesised by copolymerization of 2-hydroxyethyl methacrylate (HEMA) with methacrylic acid (MA) in accordance with a previous work (García-Millán et al., 2015). Both synthesised hydrogels and SCLs were characterized in terms of their mechanical and physical properties and TA loading and release properties. Selected TA NS was further characterized by studying its physical-chemical stability during the loading process. Results show that the use of TA NSs as loading medium significantly increases drug loading capacity and release of soft contact lenses in comparison with drug saturated solution. Synthesised pHEMA hydrogels and SCLs lenses have good properties as ophthalmic drug delivery systems, but SCLs load higher quantities of drug and release TA in shorter time periods than synthesised pHEMA hydrogel.


Assuntos
Lentes de Contato Hidrofílicas , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Triancinolona Acetonida/administração & dosagem , Administração Oftálmica , Hidrogéis , Metacrilatos
16.
Food Chem ; 224: 207-211, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28159257

RESUMO

Fumonisins are a group of mycotoxins found in various foods whose consumption is known to be harmful for human health. In this study, we evaluated the ability of three polymers (Polyvinylpolypyrrolidone, PVPP; a resin of N-vinyl-2-pyrrolidinone with ethylene glycol dimethacrylate and triallyl isocyanurate, PVP-DEGMA-TAIC; and poly(acrylamide-co-ethylene glycol-dimethacrylate), PA-EGDMA) to remove fumonisin B1 (FB1) and fumonisin B2 (FB2) from model solutions and red wine. Various polymer concentrations (1, 5 and 10mgmL-1) and contact times (2, 8 and 24h) were tested, with all polymers exhibiting fumonisin removal capacities (monitored by LC-MS). The impact of all polymers on polyphenol removal was also assessed. PA-EGDMA showed to be the most promising polymer, removing 71% and 95% of FB1, and FB2, respectively, with only a 22.2% reduction in total phenolics.


Assuntos
Fumonisinas/isolamento & purificação , Vinho/análise , Cromatografia Líquida , Humanos
17.
Methods Mol Biol ; 1504: 139-147, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27770419

RESUMO

One of the most used procedures for enzyme stabilization is immobilization. Although immobilization on solid supports has been pursued since the 1950s, there are no general rules for selecting the best support for a giving application. A macroporous copolymer of ethylene glycol dimethacrylate and glycidyl methacrylate (poly (GMA-co-EGDMA)) is a carrier consisting of macroporous beads for immobilizing enzymes of industrial potential for the production of fine chemicals and pharmaceuticals.


Assuntos
Aspergillus niger/enzimologia , Reagentes de Ligações Cruzadas/química , Enzimas Imobilizadas/química , Etilenoglicóis/química , Glucana 1,4-alfa-Glucosidase/química , Glutaral/química , Metacrilatos/química , Aspergillus niger/química , Aspergillus niger/metabolismo , Estabilidade Enzimática , Enzimas Imobilizadas/metabolismo , Óxido de Etileno/química , Glucana 1,4-alfa-Glucosidase/metabolismo , Oxirredução , Porosidade
18.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-852839

RESUMO

Objective: To prepare quercetin molecularly imprinted polymers (MIPs) by molecular imprinting technique. Methods: This experiment used quercetin as template molecule, acrylamide (AM) as functional monomers, ethylene glycol dimethacrylate (EGDMA) as cross linking agent, and azodiisobutyronitrile (AIBN) as initiator. Using anhydrous ethanol and tetrahydrofuran as pore forming agent, quercetin MIPs were prepared by precipitation polymerization and mass polymerization methods; The optimal proportion between template and functional monomer was chosen by UV and IR; The microstructure of MIPs was investigated by SEM. The adsorption equilibrium time and maximum adsorption of MIPs prepared with two methods were investigated by balance and isothermal adsorption experiment, and the specific adsorption capacity was studied. Results: The experimental research showed that precipitation polymerization method of quercetin MIPs had uniform rules of globular structures. The adsorption kinetics and isothermal adsorption experiment found faster adsorption rate and larger adsorption capacity. Polymer on quercetin had high specificity recognition ability in rutin and quercetin adsorption selective process. Conclusion: Precipitation polymerization of MIPs, with strong selective adsorption, separation and enrichment of chemical components in Chinese medicine flavonoids complex, is a new method of research. At the same time, it also provides reference for chemical composition research of other Chinese materia medica.

19.
J Interdiscip Nanomed ; 1(1): 9-18, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-27512602

RESUMO

Despite concerns over toxicity, carbon nanotubes have been extensively investigated for potential applications in nanomedicine because of their small size, unique properties, and ability to carry cargo such as small molecules and nucleic acids. Herein, we show that polymer nanotubes can be synthesized quickly and easily from a homopolymer of ethylene glycol dimethacrylate (EGDMA). The nanotubes formed via photo-initiated polymerization of the highly functional prepolymer, inside an anodized aluminium oxide template, have a regular structure and large internal pore and can be loaded with a fluorescent dye within minutes representing a simple alternative to multi-walled carbon nanotubes for biomedical applications.

20.
ACS Appl Mater Interfaces ; 8(11): 7381-9, 2016 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-26938141

RESUMO

In this work, the formation of various polystyrene (PS) colloidal structures on striped PS patterns is demonstrated based on a simple and novel convective assembly method that controls the electrostatic interactions between the PS colloidal particles and sodium dodecyl sulfate (SDS). Under the optimal conditions (different withdrawal speeds, channel dimensions, suspension concentrations, etc.), highly ordered structures such as highly close-packed, zigzag, and linear colloidal aggregates are observed. In addition, these colloidal arrangements are used for development of molecularly imprinted polymer (MIP) sensors with highly improved sensing properties. Using PDMS replicas, three hemispherical poly(methacrylic acid-ethylene glycol dimethacrylate) (poly(MAA-EGDMA)) MIP films, including planar MIP and non-imprinted polymer (NIP) films, are photopolymerized for detection of trace atrazine in an aqueous solution. From gravimetric quartz crystal microbalance (QCM) measurements, a non-close-packed MIP film exhibits highest sensing response (Δf = 932 Hz) to atrazine detection among hemispherical MIP films and shows 6.5-fold higher sensing response than the planar MIP film. In addition, the sensitivity of the MIP sensor is equivalent to -119 Hz/(mol L(-1)). From the ratio of slopes of the calibration curves for the hemispherical MIP and NIP films, the imprinting factor (If) is as high as 11.0. The hemispherical MIP film also shows excellent selectivity in comparison with the sensing responses of other analogous herbicides. As a result, this molecular surface imprinting using PS colloidal arrays is highly efficient for herbicide detection.

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