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1.
Sensors (Basel) ; 21(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207088

RESUMO

The effect of a self-pulsing non-equilibrium plasma discharge on piezoelectric PVDF nanofiber membrane was investigated. The plasma discharge was generated in air with a DC power source, with a discharge current of 0.012 mA, a nominal interelectrode separation of 1 mm, and discharge voltage of ~970 V. In a continuous fabrication process, the electrospinning method was used to generate thin nanofiber membrane with a flow rate of 0.7-1 mL h-1 and 25-27 kV voltage to obtain the nanofiber with high sensitivity and a higher degree of alignment and uniformity over a larger area. Plasma treatment was applied on both single layer and multi-layer (three layers) nanomembranes. In addition, simultaneously, the nanofiber membranes were heat-treated at a glass transition temperature (80-120 °C) and then underwent plasma treatment. Fourier-transform infrared (FTIR) spectroscopy showed that the area under the curve at 840 and 1272 cm-1 (ß phase) increased due to the application of plasma and differential scanning calorimeter (DSC) indicated an increase in the degree of crystallinity. Finally, PVDF sensors were fabricated from the nanofibers and their piezoelectric properties were characterized. The results suggested that compared to the pristine samples the piezoelectric properties in the plasma and plasma-heat-treated sensors were enhanced by 70% and 85% respectively.


Assuntos
Nanofibras , Polivinil , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
2.
Huan Jing Ke Xue ; 42(7): 3304-3315, 2021 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-34212656

RESUMO

Urban surface runoff is an important non-point pollution source, and research on contamination characteristics of runoff is urgent for improving urban aquatic environment quality. Typical cities along the downstream Yangtze River, Wuxi and Nanjing, were selected in this study, and runoff samples from various underlying surfaces were collected to investigate contamination characteristics of heavy metals and dissolved organic matter (DOM). The results indicated that the concentration of heavy metals have exceed water quality standards in underlying surfaces partly, the decreasing order of metal contaminations was Zn > Cu > Pb > Sb > Cd. Contamination characteristics of surface runoff were found to exhibit significant differences, and arterial traffic exhibited the severe contamination of both heavy metals and DOM. Spectral characteristics indicated that the structure of DOM exhibited significant differences in various underlying surfaces, and DOM humification levels in Wuxi showed the following decreasing order:roof covering > sidewalk > parking area > grassy area > arterial traffic, aromaticity indexes exhibited order as:arterial traffic > grassy area > sidewalk > roof covering > parking area. Differential absorption spectroscopy (DAS) and FT-IR analyses indicated that DOM exhibited strong combination effects with cationic metal pollutants (Cu), which mainly occur with C=C structure and carboxylic and phenolic groups; DOM presented weak combination with anion metal pollutant (Sb), indicating that Sb likely exists as a free anion in runoff. The annual total loadings of metal contaminations in the study area were as follows:Zn > Cu > Pb > Sb > Cd. The loadings of Zn were 4.83 kg·a-1 and 3.21 kg·a-1 in Wuxi and Nanjing, respectively. Annual loadings of DOM reached 0.93 g·(m2·a)-1 and 8.72 g·(m2·a)-1. The results indicated that corresponding pollution reduction measures should be implemented for different underlying surfaces to reduce contaminant concentrations; our findings may provide essential information for improving the aquatic environment quality in downstream Yangtze River.


Assuntos
Metais Pesados , Poluentes Químicos da Água , China , Cidades , Monitoramento Ambiental , Metais Pesados/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise
3.
Talanta ; 233: 122526, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215029

RESUMO

Herein, a novel magnetic porous carbon nanocomposite derived from a cobalt based-metal-organic framework was synthesized and evaluated for simultaneous preconcentration of homo and hetero-polycyclic aromatic hydrocarbons. Briefly, magnetite nanoparticles (MNPs) were synthesized and then were coated with a metal-organic framework layer. Finally, the magnetic nanocomposite was carbonized under an inert atmosphere to obtain the magnetic porous carbon (MPC). Various characterization techniques such as FT-IR spectroscopy, transmission and scanning electron microcopies, vibrating sample magnetometry, and X-ray diffraction were employed. Applicability of the MPC was explored using benzothiophene, dibenzothiophene, 9,10-dimethylanthracene, and benz[α]anthracene as the model analytes. Limits of detection and linearities were achieved in the range of 0.06-0.18 µg L-1 and 0.25-500 µg L-1, respectively. Precision of the method as RSDs was evaluated which was in the range of 4.2-7.0% (within-day, n = 5) and 8.2-11.3% (between-day, n = 3). Ultimately, the method was applied to analyze two seawater samples and satisfactory results (RSDs%, 5.0-9.0%; relative recoveries, 89-104%) were obtained.


Assuntos
Estruturas Metalorgânicas , Nanocompostos , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Carbono , Cobalto , Limite de Detecção , Fenômenos Magnéticos , Hidrocarbonetos Policíclicos Aromáticos/análise , Porosidade , Extração em Fase Sólida , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise
4.
Talanta ; 233: 122583, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215075

RESUMO

Carbon nanospheres (CNSs) were derived hydrothermally from biomass (orange peels) and decorated by manganese dioxide (MnO2) nanosheets. The MnO2/CNSs nanocomposite was intercalated into polypyrrole (PPy) during flow-through in-situ electropolymerization of pyrrole on the surface of the inner wall of a stainless-steel needle to prepare an inside-needle capillary adsorption trap (INCAT) device. The surface morphology, thermogravimetric behavior, sorption characteristics, and structure of the MnO2/CNSs@PPy nanocomposite were characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), energy dispersive X-ray analysis (EDX), nitrogen physisorption by the Brunauer-Emmett-Teller (BET) method, dynamic light scattering (DLS) size distribution, and Fourier-transform infrared spectrometry (FT-IR). The INCAT device was coupled with GC-FID and applied for dynamic headspace analysis of linear alkyl benzenes (LABs) in wastewater samples. The effective experimental variables on the extraction efficiency was optimized using a central composite design (CCD) based on response surface methodology (RSM). Under the optimal conditions, the limits of detection (LODs) were in the range of 0.5-1.0 ng mL-1. The calibration plots were linear over the range of 0.01-10 µg mL-1. The relative standard deviations (RSDs%) for intra-day, inter-day, and inter-INCAT precision were calculated 5.3-8.3%, 9.4-13.5%, and 13.6-16.9%, respectively. The developed technique was employed successfully for the analysis of LABs in water and wastewater samples with average recovery values ranging from 92 to 109%. A single INCAT device was used more than 90 times without significant change in its extraction capability.


Assuntos
Nanosferas , Polímeros , Adsorção , Biomassa , Carbono , Cromatografia Gasosa-Espectrometria de Massas , Compostos de Manganês , Óxidos , Pirróis , Espectroscopia de Infravermelho com Transformada de Fourier
5.
Talanta ; 233: 122488, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215110

RESUMO

Candida antarctica lipase B (CALB) is a natural biocatalyst with an intrinsically strong chiral environment and a high degree of enantio-selectivity, which is widely used in the separation of racemates. Here, a facile and efficient covalent immobilization approach was utilized to immobilize CALB onto the capillary inner wall as a novel chiral stationary phase to explore and broaden its application in the direct chiral separation by electrochromatography. The obtained CALB immobilized capillary column was characterized by scanning electron microscopy (SEM), fluorescence imaging and Fourier transform infrared spectroscopy (FT-IR). The enantioseparation property of the CALB immobilized capillary column was confirmed by direct chiral separation of several pairs of monoamine neurotransmitter enantiomers in OT-CEC mode. Outstanding enantioseparation performance for three types of monoamine neurotransmitter enantiomers including epinephrine, norepinephrine and phenylephrine was obtained by the CALB immobilized column. Thanks to the effectiveness of covalent bonding method and the intrinsic stability of CALB, the prepared CALB immobilized capillary columns were quite steady and reproducible. The relative standard deviations for retention times of the enantiomers were as follows: for intra-day (n = 5) runs (≤0.25%), inter-day (n = 3) runs (≤0.72%) and between-columns (n = 3) (≤2.42%). After 90 consecutive runs in CEC mode, the CALB immobilized column still exhibited desirable enantionseparation performance.


Assuntos
Eletrocromatografia Capilar , Basidiomycota , Lipase , Espectroscopia de Infravermelho com Transformada de Fourier , Estereoisomerismo
6.
Int J Mol Sci ; 22(12)2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34198522

RESUMO

We synthesized phenylboronic acid pinacol ester (PBPE)-conjugated hyaluronic acid (HA) via thiobis(ethylamine) (TbEA) linkage (abbreviated as HAsPBPE conjugates) to fabricate the radiosensitive delivery of caffeic acid phenetyl ester (CAPE) and for application in radioprotection. PBPE was primarily conjugated with TbEA and then PBPE-TbEA conjugates were conjugated again with hyaluronic acid using carbodiimide chemistry. CAPE-incorporated nanoparticles of HAsPBPE were fabricated by the nanoprecipitation method and then the organic solvent was removed by dialysis. CAPE-incorporated HAsPBPE nanoparticles have a small particle size of about 80 or 100 nm and they have a spherical shape. When CAPE-incorporated HAsPBPE nanoparticles were irradiated, nanoparticles became swelled or disintegrated and their morphologies were changed. Furthermore, the CAPE release rate from HAsPBPE nanoparticles were increased according to the radiation dose, indicating that CAPE-incorporated HAsPBPE nanoparticles have radio-sensitivity. CAPE and CAPE-incorporated HAsPBPE nanoparticles appropriately prevented radiation-induced cell death and suppressed intracellular accumulation of reactive oxygen species (ROS). CAPE and CAPE-incorporated HAsPBPE nanoparticles efficiently improved survivability of mice from radiation-induced death and reduced apoptotic cell death. We suggest that HAsPBPE nanoparticles are promising candidates for the radio-sensitive delivery of CAPE.


Assuntos
Ácidos Borônicos/química , Ácidos Cafeicos/farmacologia , Glicóis/química , Ácido Hialurônico/química , Nanopartículas/química , Álcool Feniletílico/análogos & derivados , Proteção Radiológica , Animais , Ácidos Borônicos/síntese química , Ácidos Cafeicos/síntese química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Peróxido de Hidrogênio/toxicidade , Fígado/metabolismo , Camundongos Endogâmicos BALB C , Nanopartículas/ultraestrutura , Tamanho da Partícula , Álcool Feniletílico/síntese química , Álcool Feniletílico/farmacologia , Espectroscopia de Prótons por Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Molecules ; 26(12)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201182

RESUMO

Most biosurfactants are obtained using costly culture media and purification processes, which limits their wider industrial use. Sustainability of their production processes can be achieved, in part, by using cheap substrates found among agricultural and food wastes or byproducts. In the present study, crude glycerol, a raw material obtained from several industrial processes, was evaluated as a potential low-cost carbon source to reduce the costs of surfactin production by Bacillus subtilis #309. The culture medium containing soap-derived waste glycerol led to the best surfactin production, reaching about 2.8 g/L. To the best of our knowledge, this is the first report describing surfactin production by B. subtilis using stearin and soap wastes as carbon sources. A complete chemical characterization of surfactin analogs produced from the different waste glycerol samples was performed by liquid chromatography-mass spectrometry (LC-MS) and Fourier transform infrared spectroscopy (FTIR). Furthermore, the surfactin produced in the study exhibited good stability in a wide range of pH, salinity and temperatures, suggesting its potential for several applications in biotechnology.


Assuntos
Bacillus subtilis/química , Glicerol/química , Tensoativos/química , Biotecnologia/métodos , Carbono/química , Cromatografia Líquida/métodos , Meios de Cultura/química , Concentração de Íons de Hidrogênio , Espectrometria de Massas/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Temperatura
8.
Molecules ; 26(12)2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-34204669

RESUMO

Abelmoschus esculentus (Okra) is an important vegetable crop, widely cultivated around the world due to its high nutritional significance along with several health benefits. Different parts of okra including its mucilage have been currently studied for its role in various therapeutic applications. Therefore, we aimed to develop and characterize the okra mucilage biopolymer (OMB) for its physicochemical properties as well as to evaluate its in vitro antidiabetic activity. The characterization of OMB using Fourier-transform infrared spectroscopy (FT-IR) revealed that okra mucilage containing polysaccharides lies in the bandwidth of 3279 and 1030 cm-1, which constitutes the fingerprint region of the spectrum. In addition, physicochemical parameters such as percentage yield, percentage solubility, and swelling index were found to be 2.66%, 96.9%, and 5, respectively. A mineral analysis of newly developed biopolymers showed a substantial amount of calcium (412 mg/100 g), potassium (418 mg/100 g), phosphorus (60 mg/100 g), iron (47 mg/100 g), zinc (16 mg/100 g), and sodium (9 mg/100 g). The significant antidiabetic potential of OMB was demonstrated using α-amylase and α-glucosidase enzyme inhibitory assay. Further investigations are required to explore the newly developed biopolymer for its toxicity, efficacy, and its possible utilization in food, nutraceutical, as well as pharmaceutical industries.


Assuntos
Abelmoschus/química , Mucilagem Vegetal/química , Mucilagem Vegetal/isolamento & purificação , Abelmoschus/metabolismo , Antioxidantes/química , Biopolímeros/análise , Biopolímeros/química , Suplementos Nutricionais , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/metabolismo , Extratos Vegetais/farmacologia , Polissacarídeos/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , alfa-Amilases/química , alfa-Glucosidases/química
9.
Molecules ; 26(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207072

RESUMO

The aim of the research was to prepare low-cost adsorbents, including raw date pits and chemically treated date pits, and to apply these materials to investigate the adsorption behavior of Cr(III) and Cd(II) ions from wastewater. The prepared materials were characterized using SEM, FT-IR and BET surface analysis techniques for investigating the surface morphology, particle size, pore size and surface functionalities of the materials. A series of adsorption processes was conducted in a batch system and optimized by investigating various parameters such as solution pH, contact time, initial metal concentrations and adsorbent dosage. The optimum pH for achieving maximum adsorption capacity was found to be approximately 7.8. The determination of metal ions was conducted using atomic adsorption spectrometry. The experimental results were fitted using isotherm Langmuir and Freundlich equations, and maximum monolayer adsorption capacities for Cr(III) and Cd(II) at 323 K were 1428.5 and 1302.0 mg/g (treated majdool date pits adsorbent) and 1228.5 and 1182.0 mg/g (treated sagai date pits adsorbent), respectively. It was found that the adsorption capacity of H2O2-treated date pits was higher than that of untreated DP. Recovery studies showed maximal metal elution with 0.1 M HCl for all the adsorbents. An 83.3-88.2% and 81.8-86.8% drop in Cr(III) and Cd(II) adsorption, respectively, were found after the five regeneration cycles. The results showed that the Langmuir model gave slightly better results than the Freundlich model for the untreated and treated date pits. Hence, the results demonstrated that the prepared materials could be a low-cost and eco-friendly choice for the remediation of Cr(III) and Cd(II) contaminants from an aqueous solution.


Assuntos
Cádmio/química , Cromo/química , Metais Pesados/química , Phoeniceae/química , Sementes/química , Água/química , Adsorção , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Íons/química , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Águas Residuárias/química , Poluentes Químicos da Água/química , Purificação da Água/métodos
10.
Molecules ; 26(11)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34206027

RESUMO

The utilization of biorefinery lignins as a renewable resource for the production of bio-based chemicals and materials remain a challenge because of the high polysaccharide content of this variety of lignins. This study provides two simple methods; (i) the alkaline hydrolysis-acid precipitation method and (ii) the acid hydrolysis method for the removal of polysaccharides from polymeric biorefinery lignin samples. Both purification strategies are optimized for two different hardwood hydrolysis lignins, HL1 and HL2, containing 15.1% and 10.1% of polysaccharides, respectively. The treated lignins are characterized by polysaccharide content, molecular weight, hydroxyl content, and Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR). Preliminary techno-economic calculations are also carried out for both purification processes to assess the economic potential of these technologies. The results indicate that both protocols could be used for the purification of HL1 and HL2 hydrolysis lignins because of the minimal polysaccharide content obtained in the treated lignins. Nevertheless, from an industrial and economic perspective the acid hydrolysis technology using low acid concentrations and high temperatures is favored over the alkaline hydrolysis-acid precipitation strategy.


Assuntos
Lignina/química , Polissacarídeos/análise , Madeira/química , Biotecnologia , Precipitação Química , Hidrólise , Peso Molecular , Espectroscopia de Infravermelho com Transformada de Fourier
11.
Molecules ; 26(11)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199337

RESUMO

This study aimed to understand the adsorption process of cephalexin (CPX) from aqueous solution by a biochar produced from the fiber residue of palm oil. Scanning electron microscopy, Fourier transform infrared spectroscopy, Boehm titration, and the point of zero charge were used to characterize the morphology and surface functional groups of the adsorbent. Batch tests were carried out to evaluate the effects of the solution pH, temperature, and antibiotic structure. The adsorption behavior followed the Langmuir model and pseudo-second-order model with a maximum CPX adsorption capacity of 57.47 mg g-1. Tests on the thermodynamic behavior suggested that chemisorption occurs with an activation energy of 91.6 kJ mol-1 through a spontaneous endothermic process. Electrostatic interactions and hydrogen bonding represent the most likely adsorption mechanisms, although π-π interactions also appear to contribute. Finally, the CPX removal efficiency of the adsorbent was evaluated for synthetic matrices of municipal wastewater and urine. Promising results were obtained, indicating that this adsorbent can potentially be applied to purifying wastewater that contains trace antibiotics.


Assuntos
Cefalexina/análise , Óleo de Palmeira/química , Poluentes Químicos da Água/análise , Adsorção , Carvão Vegetal/química , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Purificação da Água
12.
Sensors (Basel) ; 21(13)2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34202332

RESUMO

Nickel manganite nanocrystalline fibers were obtained by electrospinning and subsequent calcination at 400 °C. As-spun fibers were characterized by TG/DTA, Scanning Electron Microscopy and FT-IR spectroscopy analysis. X-ray diffraction and FT-IR spectroscopy analysis confirmed the formation of nickel manganite with a cubic spinel structure, while N2 physisorption at 77 K enabled determination of the BET specific surface area as 25.3 m2/g and (BJH) mesopore volume as 21.5 m2/g. The material constant (B) of the nanocrystalline nickel manganite fibers applied by drop-casting on test interdigitated electrodes on alumina substrate, dried at room temperature, was determined as 4379 K in the 20-50 °C temperature range and a temperature sensitivity of -4.95%/K at room temperature (25 °C). The change of impedance with relative humidity was monitored at 25 and 50 °C for a relative humidity (RH) change of 40 to 90% in the 42 Hzπ1 MHz frequency range. At 100 Hz and 25 °C, the sensitivity of 327.36 ± 80.12 kΩ/%RH was determined, showing that nickel manganite obtained by electrospinning has potential as a multifunctional material for combined humidity and temperature sensing.


Assuntos
Níquel , Umidade , Compostos de Manganês , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
13.
Environ Pollut ; 284: 117507, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34261218

RESUMO

Wastewater containg proteinaceous ossein effluents are problematic to be treated. We studied the possibility to treat ossein effluents with the marine cyanobacterium strain Cylindrospermum stagnale. After optimizing the culture conditions of the bacterium, three different types of ossein effluents were tested: dicalcium phosphate (DCP), high total dissolved solids (HTDS) and low total dissolved (LTDS). The effluents were diluted with sea water at the following ratios 1:1, 2:1 and 3:2. The optimum operating conditions were at 3000 lux light intensity and 37 °C temperature. The highest degradation of ossein effluens by C. stagnale was attained for a dilution ratio of 1:1. However, less diluted ossein effluents reduced the growth of C. stagnale drastically. The degradation was shown by measuring the chlorophyll a content and the dry weight of bacterial cells during a seven-day incubation period degradation. Fourier Transform Infrared Spectroscopy (FT-IR) analysis verified the degradation showing the presence of the degradation products of ossein (i.e. calcium carbonate and calcite) in the culture medium. Lipid composition in fatty acids appeared to be suitable for biofuel production. The results showed that the marine cyanobacterium C. stagnale can be used to treat ossein effluents, and at the same time, to produce biofuel in a sustainable way.


Assuntos
Cianobactérias , Biodegradação Ambiental , Clorofila A , Espectroscopia de Infravermelho com Transformada de Fourier
14.
Int J Mol Sci ; 22(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204524

RESUMO

The aim of this work is to develop a biomimetic interface between the natural tooth tissue and the restorative composite and to study it on the basis of synchrotron micro-FTIR mapping and multidimensional processing of the spectral data array. Using hierarchical cluster analysis of 3D FTIR data revealed marked improvements in the formation of the dentine/adhesive/dental hybrid interface using a biomimetic approach. The use of a biomimetic strategy (application of an amino acid-modified primer, alkaline calcium and a nano-c-HAp-modified adhesive) allowed the formation of a matrix that can be structurally integrated with natural dentine and dental composite. The biomimetic hybrid layer was characterised by homogeneous chemical composition and a higher degree of conversion of the adhesive during polymerisation, which should provide optimal integration of the dental composite with the dentine.


Assuntos
Biomimética , Odontologia , Espectroscopia de Infravermelho com Transformada de Fourier , Síncrotrons , Engenharia Tecidual , Dente , Biomimética/métodos , Odontologia/métodos , Humanos , Teste de Materiais , Nanotecnologia , Imagem Óptica/métodos
15.
Bone Joint J ; 103-B(7): 1238-1246, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34192940

RESUMO

AIMS: Dual mobility implants in total hip arthroplasty are designed to increase the functional head size, thus decreasing the potential for dislocation. Modular dual mobility (MDM) implants incorporate a metal liner (e.g. cobalt-chromium alloy) in a metal shell (e.g. titanium alloy), raising concern for mechanically assisted crevice corrosion at the modular liner-shell connection. We sought to examine fretting and corrosion on MDM liners, to analyze the corrosion products, and to examine histologically the periprosthetic tissues. METHODS: A total of 60 retrieved liners were subjectively scored for fretting and corrosion. The corrosion products from the three most severely corroded implants were removed from the implant surface, imaged using scanning electron microscopy, and analyzed using Fourier-transform infrared spectroscopy. RESULTS: Fretting was present on 88% (53/60) of the retrieved liners, and corrosion was present on 97% (58/60). Fretting was most often found on the lip of the taper at the transition between the lip and the dome regions. Macrophages and particles reflecting an innate inflammatory reaction to corrosion debris were noted in six of the 48 cases for which periprosthetic tissues were examined, and all were associated with retrieved components that had high corrosion scores. CONCLUSION: Our results show that corrosion occurs at the interface between MDM liners and shells and that it can be associated with reactions in the local tissues, suggesting continued concern that this problem may become clinically important with longer-term use of these implants. Cite this article: Bone Joint J 2021;103-B(7):1238-1246.


Assuntos
Ligas de Cromo/química , Prótese de Quadril , Desenho de Prótese , Titânio/química , Adulto , Idoso , Idoso de 80 Anos ou mais , Artroplastia de Quadril , Corrosão , Remoção de Dispositivo , Feminino , Humanos , Masculino , Microscopia Eletrônica de Varredura , Pessoa de Meia-Idade , Polietileno/química , Falha de Prótese , Reoperação , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície
16.
Molecules ; 26(12)2021 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-34205446

RESUMO

A combination of Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR) and 2D correlation analysis (2D-COS) was applied here for the first time in order to investigate the temperature-dependent dynamical evolution occurring in a particular type of inclusion complex, based on sulfobutylether-ß-cyclodextrin (SBE-ß-CD) as hosting agent and Coumestrol (7,12-dihydorxcoumestane, Coum), a poorly-soluble active compound known for its anti-viral and anti-oxidant activity. For this purpose, synchronous and asynchronous 2D spectra were calculated in three different wavenumber regions (960-1320 cm-1, 1580-1760 cm-1 and 2780-3750 cm-1) and over a temperature range between 250 K and 340 K. The resolution enhancement provided by the 2D-COS offers the possibility to extract the sequential order of events tracked by specific functional groups of the system, and allows, at the same time, the overcoming of some of the limits associated with conventional 1D FTIR-ATR analysis. Acquired information could be used, in principle, for the definition of an optimized procedure capable to provide high-performance T-sensitive drug carrier systems for different applications.


Assuntos
Cumestrol/química , beta-Ciclodextrinas/química , Antioxidantes/química , Antivirais/química , Portadores de Fármacos/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Temperatura
17.
Molecules ; 26(11)2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34205185

RESUMO

Attention deficit and hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders of childhood. It affects ~10% of the world's population of children, and about 30-50% of those diagnosed in childhood continue to show ADHD symptoms later, with 2-5% of adults having the condition. Current diagnosis of ADHD is based on the clinical evaluation of the patient, and on interviews performed by clinicians with parents and teachers of the children, which, together with the fact that it shares common symptoms and frequent comorbidities with other neurodevelopmental disorders, makes the accurate and timely diagnosis of the disorder a difficult task. Despite the large effort to identify reliable biomarkers that can be used in a clinical environment to support clinical diagnosis, this goal has never been achieved hitherto. In the present study, infrared spectroscopy was used together with multivariate statistical methods (hierarchical clustering and partial least-squares discriminant analysis) to develop a model based on the spectra of blood serum samples that is able to distinguish ADHD patients from healthy individuals. The developed model used an approach where the whole infrared spectrum (in the 3700-900 cm-1 range) was taken as a holistic imprint of the biochemical blood serum environment (spectroscopic biomarker), overcoming the need for the search of any particular chemical substance associated with the disorder (molecular biomarker). The developed model is based on a sensitive and reliable technique, which is cheap and fast, thus appearing promising to use as a complementary diagnostic tool in the clinical environment.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Adolescente , Transtorno do Deficit de Atenção com Hiperatividade/sangue , Estudos de Casos e Controles , Criança , Análise Discriminante , Diagnóstico Precoce , Feminino , Humanos , Masculino , Análise Multivariada
18.
Molecules ; 26(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200814

RESUMO

Multi-drug resistant pathogens are a rising danger for the future of mankind. Iodine (I2) is a centuries-old microbicide, but leads to skin discoloration, irritation, and uncontrolled iodine release. Plants rich in phytochemicals have a long history in basic health care. Aloe Vera Barbadensis Miller (AV) and Salvia officinalis L. (Sage) are effectively utilized against different ailments. Previously, we investigated the antimicrobial activities of smart triiodides and iodinated AV hybrids. In this work, we combined iodine with Sage extracts and pure AV gel with polyvinylpyrrolidone (PVP) as an encapsulating and stabilizing agent. Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible spectroscopy (UV-Vis), Surface-Enhanced Raman Spectroscopy (SERS), microstructural analysis by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-Ray-Diffraction (XRD) analysis verified the composition of AV-PVP-Sage-I2. Antimicrobial properties were investigated by disc diffusion method against 10 reference microbial strains in comparison to gentamicin and nystatin. We impregnated surgical sutures with our biohybrid and tested their inhibitory effects. AV-PVP-Sage-I2 showed excellent to intermediate antimicrobial activity in discs and sutures. The iodine within the polymeric biomaterial AV-PVP-Sage-I2 and the synergistic action of the two plant extracts enhanced the microbial inhibition. Our compound has potential for use as an antifungal agent, disinfectant and coating material on sutures to prevent surgical site infections.


Assuntos
Antibacterianos/química , Antibacterianos/síntese química , Aloe/química , Antifúngicos/química , Gentamicinas/química , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura/métodos , Nistatina/química , Extratos Vegetais/química , Povidona/química , Salvia/química , Salvia officinalis/química , Espectrometria por Raios X/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Difração de Raios X/métodos
19.
Int J Mol Sci ; 22(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207149

RESUMO

In this study, four different coal fly ashes (CFAs) were used as raw materials of silica and alumina for the preparation of the alumina-containing Mobil Composition of Matter No. 41 (Al-MCM-41) and the exploration of an activation strategy that is efficient and universal for various CFAs. Alkaline hydrothermal and alkaline fusion activations proceeded at different temperatures to determine the best treatment parameters. We controlled the pore structure and surface hydroxyl density of the CFA-derived Al-MCM-41 by changing the crystallization temperature and aging time. The products were characterized by small-angle X-ray diffraction, nitrogen isotherms, Fourier-transform infrared spectroscopy, 29Si silica magic-angle spinning nuclear magnetic resonance, and transmission electron microscopy, and they were then grafted with thiol groups to remove Pb(II) from aqueous solutions. This paper innovatively evaluates the CFA activation strategies using energy consumption analysis and determines the optimal activation methodology and parameters. This paper also unveils the effect of the crystallization condition of Al-MCM-41 on its subsequent Pb(II) removal capacity. The results show that the appropriate selection of crystallization parameters can considerably increase the removal capacity over Pb(II), providing a new path to tackle the ever-increasing concern of aquic heavy-metal pollution.


Assuntos
Óxido de Alumínio/química , Cinza de Carvão/química , Carvão Mineral/análise , Chumbo/química , Dióxido de Silício/química , Algoritmos , Cristalização , Modelos Teóricos , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
20.
Int J Mol Sci ; 22(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208782

RESUMO

This paper concerns the physicochemical properties of chitosan/phenolic acid thin films irradiated by ultraviolet radiation with wavelengths between 200 and 290 nm (UVC) light. We investigated the preparation and characterization of thin films based on chitosan (CTS) with tannic (TA), caffeic (CA) and ferulic acid (FA) addition as potential food-packaging materials. Such materials were then exposed to the UVC light (254 nm) for 1 and 2 h to perform the sterilization process. Different properties of thin films before and after irradiation were determined by various methods such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), differential scanning calorimeter (DSC), mechanical properties and by the surface free energy determination. Moreover, the antimicrobial activity of the films and their potential to reduce the risk of contamination was assessed. The results showed that the phenolic acid improving properties of chitosan-based films, short UVC radiation may be used as sterilization method for those films, and also that the addition of ferulic acid obtains effective antimicrobial activity, which have great benefit for food packing applications.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Quitosana/química , Hidroxibenzoatos/química , Raios Ultravioleta , Aderência Bacteriana/efeitos dos fármacos , Varredura Diferencial de Calorimetria , Fenômenos Químicos , Fenômenos Mecânicos , Testes de Sensibilidade Microbiana , Microscopia de Força Atômica , Espectroscopia de Infravermelho com Transformada de Fourier
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