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1.
J Environ Manage ; 301: 113854, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34607141

RESUMO

Insights into thermal degradation behaviour, kinetics, reaction mechanism, possible synergism, and thermodynamic analysis of co-pyrolysis of carbonaceous materials are crucial for efficient design of co-pyrolysis reactor systems. Present study deals with comprehensive kinetics and thermodynamic investigation of co-pyrolysis of petroleum coke (PC) and banana leaves biomass (BLB) for realizing the co-pyrolysis potential. Thermogravimetric non-isothermal studies have been performed at 10, 20, and 30 °C/min heating rates. Synergistic effect between PC and BLB was determined by Devolatilization index (Di) and mass loss method. Kinetic parameters were estimated using seven model-free methods. Standard activation energy for PC + BLB blend from FWO, KAS, Starink, and Vyazovkin methods was ≈165 kJ/mol and that from Friedman and Vyazovkin advanced isoconversional methods was ≈171 kJ/mol. The frequency factor calculated for the blend from Kissinger method was found to be in the range of 106-1016s-1. Devolatilization index (Di) showed synergistic effect of blending. The data pertaining to co-pyrolysis was found to fit well with R2 (second order) and D3 (three dimensional) from Z(α) master plot. Thermodynamic parameters, viz. ΔH ≈ 163 kJ/mol and ΔG ≈ 151 kJ/mol were calculated to determine the feasibility and reactivity of the co-pyrolysis process. The results are expected to be useful in the design of petcoke and banana leaves biomass co-pyrolysis systems.


Assuntos
Coque , Musa , Petróleo , Biomassa , Cinética , Folhas de Planta , Pirólise , Termodinâmica , Termogravimetria
2.
Chemosphere ; 286(Pt 3): 131901, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34449323

RESUMO

Mustard waste briquettes are commercially used as a fuel for power production in boilers, whereas the thermal kinetics of the biomass plays a vital role in deciding the process parameters. The pyrolysis process converts biomass to value-added products such as biochar, bio-oil, and hydrocarbon gases based on the heating rates and temperature. To enhance the pyrolytic activity of mustard biomass, magnetically separable and reusable FeNi alloy catalyst is investigated. The thermo-conversion properties are studied under variable heating rates with 2 and 10% FeNi particles prepared through a facile chemical reduction technique. Thermal kinetics is computed using Flynn-Wall-Ozawa (FOW) and Kissinger-Akahira-Sunose (KAS) methods. The activation energies calculated using FOW and KAS methods increase with FeNi addition in mustard while the calorific value decreases. The FeNi alloy particles with the spike-like morphology provide better metal-biomass binding resulting in higher activation energy and facilitates the easy decomposition of lignin. The 10% FeNi -mustard shows uniform conversion independent of heating rates, suitable for magnetically recoverable catalytic pyrolysis. Response surface methodology analysis predicts optimum conversion for 10% FeNi added mustard and less significance for the heating rates in concurrence with the experiments. Artificial neural network utilized to predict and validate mass loss for mustard biomass exhibits best fit for the three neural hidden layer and one output layered topology.


Assuntos
Mostardeira , Níquel , Biomassa , Ferro , Cinética , Termogravimetria
3.
Sci Total Environ ; 804: 150217, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34520910

RESUMO

Co-pyrolysis technology of urban solid waste and biomass has broad application prospects in alleviating energy crisis and environmental pollution. In this study, thermogravimetric-Fourier transform infrared spectroscopy (TG-FTIR) was used to study the co-pyrolysis characteristics of coal gangue (CG) and coffee industry residue (CIR). CG and CIR were uniformly mixed according to the mass ratios of 1: 0, 7:3, 5:5, 3:7, and 0:1. Then the samples were heated and pyrolyzed in an atmosphere with a nitrogen flow rate of 60 mL/min. As the proportion of CG increased, the comprehensive pyrolysis index (CPI) showed an exponential decrease. FTIR detected that the gas produced by pyrolysis of CG-CIR contained hydroxyl compounds, hydrocarbons, CO2, CO, Phenols, and NH3. CG-CIR co-pyrolysis had obvious interaction. By using Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods, the relationship between activation energy (Eα) and kinetic parameters and conversion degree was studied. Principal component analysis (PCA) was used to determine the principal reaction of CG-CIR pyrolysis. ANN 21 was the best model for predicting the pyrolysis of CG-CIR.


Assuntos
Carvão Mineral , Pirólise , Biomassa , Carvão Mineral/análise , Café , Cinética , Idioma , Termodinâmica , Termogravimetria
4.
Molecules ; 26(19)2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34641270

RESUMO

The conjugation of biomolecules to magnetic nanoparticles has emerged as promising approach in biomedicine as the treatment of several diseases, such as cancer. In this study, conjugation of bioactive peptide fractions from germinated soybeans to magnetite nanoparticles was achieved. Different fractions of germinated soybean peptides (>10 kDa and 5-10 kDa) were for the first time conjugated to previously coated magnetite nanoparticles (with 3-aminopropyltriethoxysilane (APTES) and sodium citrate) by the Ugi four-component reaction. The crystallinity of the nanoparticles was corroborated by X-ray diffraction, while the particle size was determined by scanning transmission electron microscopy. The analyses were carried out using infrared and ultraviolet-visible spectroscopy, dynamic light scattering, and thermogravimetry, which confirmed the coating and functionalization of the magnetite nanoparticles and conjugation of different peptide fractions on their surfaces. The antioxidant activity of the conjugates was determined by the reducing power and hydroxyl radical scavenging activity. The nanoparticles synthesized represent promising materials, as they have found applications in bionanotechnology for enhanced treatment of diseases, such as cancer, due to a higher antioxidant capacity than that of fractions without conjugation. The highest antioxidant capacity was observed for a >10 kDa peptide fraction conjugated to the magnetite nanoparticles coated with APTES.


Assuntos
Antioxidantes/farmacologia , Nanopartículas de Magnetita/química , Peptídeos/farmacologia , Soja/química , Antioxidantes/química , Sequestradores de Radicais Livres/química , Germinação , Tamanho da Partícula , Peptídeos/química , Propilaminas/química , Silanos/química , Citrato de Sódio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Difração de Raios X
5.
Sci Rep ; 11(1): 20877, 2021 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-34686689

RESUMO

Adenovirus vectors offer a platform technology for vaccine development. The value of the platform has been proven during the COVID-19 pandemic. Although good stability at 2-8 °C is an advantage of the platform, non-cold-chain distribution would have substantial advantages, in particular in low-income countries. We have previously reported a novel, potentially less expensive thermostabilisation approach using a combination of simple sugars and glass micro-fibrous matrix, achieving excellent recovery of adenovirus-vectored vaccines after storage at temperatures as high as 45 °C. This matrix is, however, prone to fragmentation and so not suitable for clinical translation. Here, we report an investigation of alternative fibrous matrices which might be suitable for clinical use. A number of commercially-available matrices permitted good protein recovery, quality of sugar glass and moisture content of the dried product but did not achieve the thermostabilisation performance of the original glass fibre matrix. We therefore further investigated physical and chemical characteristics of the glass fibre matrix and its components, finding that the polyvinyl alcohol present in the glass fibre matrix assists vaccine stability. This finding enabled us to identify a potentially biocompatible matrix with encouraging performance. We discuss remaining challenges for transfer of the technology into clinical use, including reliability of process performance.


Assuntos
Adenoviridae/genética , Vacinas contra Adenovirus/química , Vacinas contra COVID-19/uso terapêutico , COVID-19/prevenção & controle , Potência de Vacina , Adenovirus dos Símios , Materiais Biocompatíveis , Varredura Diferencial de Calorimetria , Vidro , Células HEK293 , Humanos , Luz , Espectroscopia de Ressonância Magnética , Teste de Materiais , Microscopia Confocal , Microscopia Eletrônica de Varredura , Álcool de Polivinil , Vacinas Antirrábicas , Espalhamento de Radiação , Espectroscopia de Infravermelho com Transformada de Fourier , Açúcares/química , Temperatura , Termogravimetria , Trealose/química
6.
Bioresour Technol ; 341: 125891, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34523576

RESUMO

In the present study, pyrolysis of mangifera indica L., Artocarpus heterophyllus L. and jambolana seeds have been performed using thermogravimetric analysis. These biomasses have enriched lignocellulosic composition of hemicellulose (5-10%) and lignin (1-3%) which are unexplored. The TGA analysis was performed at various heating rates of 10, 15, 20, 25 and 30 °C/min from 25 to 600 °C. Kinetic investigation of the pyrolysis method using TGA statistics has been done using iso-conversional models of Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, Vyazovkin and Vyazovkin AIC. The apparent activation energies value ranged from 179.86 to 226.31 kJ/mol in the fractional conversion range of 0.1 to 0.7.


Assuntos
Artocarpus , Lignina/análise , Mangifera , Sementes/química , Syzygium , Biomassa , Cinética , Termogravimetria
7.
Acta Crystallogr C Struct Chem ; 77(Pt 9): 566-576, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34482301

RESUMO

Quinine (an antimalarial) and aspirin (a nonsteroidal anti-inflammatory drug) were combined into a new drug-drug salt, quininium aspirinate, C20H25N2O2+·C9H7O4-, by liquid-assisted grinding using stoichiometric amounts of the reactants in a 1:1 molar ratio, and water, EtOH, toluene, or heptane as additives. A tetrahydrofuran (THF) solution of the mechanochemical product prepared using EtOH as additive led to a single crystal of the same material obtained by mechanochemistry, which was used for crystal structure determination at 100 K. Powder X-ray diffraction ruled out crystallographic phase transitions in the 100-295 K interval. Neat mechanical treatment (in a mortar and pestle, or in a ball mill at 20 or 30 Hz milling frequencies) gave rise to an amorphous phase, as shown by powder X-ray diffraction; however, FT-IR spectroscopy unambiguously indicates that a mechanochemical reaction has occurred. Neat milling the reactants at 10 and 15 Hz led to incomplete reactions. Thermogravimetry and differential scanning calorimetry indicate that the amorphous and crystalline mechanochemical products form glasses/supercooled liquids before melting, and do not recrystallize upon cooling. However, the amorphous material obtained by neat grinding crystallizes upon storage into the salt reported. The mechanochemical synthesis, crystal structure analysis, Hirshfeld surfaces, powder X-ray diffraction, thermogravimetry, differential scanning calorimetry, FT-IR spectroscopy, and aqueous solubility of quininium aspirinate are herein reported.


Assuntos
Anti-Inflamatórios não Esteroides/síntese química , Aspirina/síntese química , Quinina/síntese química , Anti-Inflamatórios não Esteroides/química , Aspirina/química , Varredura Diferencial de Calorimetria , Cristalografia por Raios X , Ligação de Hidrogênio , Preparações Farmacêuticas , Transição de Fase , Quinina/química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Difração de Raios X
8.
Int J Mol Sci ; 22(17)2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34502540

RESUMO

The functionalization of microcrystalline cellulose (MCC) is an important strategy for broadening its application fields. In the present work, MCC was functionalized by phosphorylation reaction with phytic acid (PA) for enhanced flame retardancy. The conditions of phosphorylation reaction including PA concentration, MCC/PA weight ratio and temperature were discussed, and the thermal degradation, heat release and char-forming properties of the resulting PA modified MCC were studied by thermogravimetric analysis and pyrolysis combustion flow calorimetry. The PA modified MCC, which was prepared at 90 °C, 50%PA and 1:3 weight ratio of MCC to PA, exhibited early thermal dehydration with rapid char formation as well as low heat release capability. This work suggests a novel strategy for the phosphorylation of cellulose using PA and reveals that the PA phosphorylated MCC can act as a promising flame retardant material.


Assuntos
Celulose/química , Ácido Fítico/química , Celulose/metabolismo , Retardadores de Chama , Temperatura Alta , Estrutura Molecular , Fosforilação , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Temperatura , Têxteis/análise , Termogravimetria/métodos
9.
Molecules ; 26(18)2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34576926

RESUMO

Novel UV-curable polyurethane acrylate (PUA) resins were developed from rubber seed oil (RSO). Firstly, hydroxylated rubber seed oil (HRSO) was prepared via an alcoholysis reaction of RSO with glycerol, and then HRSO was reacted with isophorone diisocyanate (IPDI) and hydroxyethyl acrylate (HEA) to produce the RSO-based PUA (RSO-PUA) oligomer. FT-IR and 1H NMR spectra collectively revealed that the obtained RSO-PUA was successfully synthesized, and the calculated C=C functionality of oligomer was 2.27 per fatty acid. Subsequently, a series of UV-curable resins were prepared and their ultimate properties, as well as UV-curing kinetics, were investigated. Notably, the UV-cured materials with 40% trimethylolpropane triacrylate (TMPTA) displayed a tensile strength of 11.7 MPa, an adhesion of 2 grade, a pencil hardness of 3H, a flexibility of 2 mm, and a glass transition temperature up to 109.4 °C. Finally, the optimal resin was used for digital light processing (DLP) 3D printing. The critical exposure energy of RSO-PUA (15.20 mJ/cm2) was lower than a commercial resin. In general, this work offered a simple method to prepare woody plant oil-based high-performance PUA resins that could be applied in the 3D printing industry.


Assuntos
Acrilatos/química , Gorduras Insaturadas/química , Poliuretanos/química , Impressão Tridimensional , Géis/química , Dureza , Hidroxilação , Espectroscopia de Ressonância Magnética , Resinas Sintéticas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração , Termogravimetria , Raios Ultravioleta
10.
Molecules ; 26(18)2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34576935

RESUMO

The drying of fruit juices has advantages such as easy handling of powders, reduction in volume, and preservation of the characteristics of the fruit. Thus, in this work, the effect of the spray drying conditions of strawberry juice (SJ) with maltodextrin (MX) as a carrying agent on the microencapsulation of bioactive compounds and physicochemical properties was studied. The content of phenolic compounds and antioxidant activity showed higher values at low concentrations of MX, while the effect of drying temperature was negligible. The thermal characterization showed that the low molecular weight sugars in the juice decreased the glass transition temperature (Tg). The morphological analysis by scanning electron microscopy (SEM) indicated that at low concentrations of MX, the particles agglomerated, while at intermediate and high concentrations, the particles were observed as well separated. Through microstructural analysis by X-ray diffraction (XRD), the presence of amorphous state was confirmed in all the samples, which is beneficial for preventing chemical and biochemical reactions, and promoting the conservation of the microencapsulated bioactive compounds.


Assuntos
Composição de Medicamentos/métodos , Fragaria/química , Pós/química , Antioxidantes/química , Sucos de Frutas e Vegetais , Microscopia Eletrônica de Varredura , Fenóis/análise , Polissacarídeos/química , Secagem por Atomização , Temperatura , Termogravimetria , Difração de Raios X
11.
J Environ Sci (China) ; 107: 124-137, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34412775

RESUMO

An unavoidable but reusable waste so as to enhance a more circular waste utilization has been spent potlining (SPL) generated by the aluminum industry. The combustion mechanisms, evolved gasses, and ash properties of SPL were characterized dynamically in response to the elevated temperature and heating rates. Differential scanning calorimetric (DSC) results indicated an exothermic reaction behavior probably able to meet the energy needs of various industrial applications. The reaction mechanisms for the SPL combustion were best described using the 1.5-, 3- and 2.5-order reaction models. Fluoride volatilization rate of the flue gas was estimated at 2.24%. The SPL combustion emitted CO2, HNCO, NO, and NO2 but SOx. The joint optimization of remaining mass, derivative thermogravimetry, and derivative DSC was achieved with the optimal temperature and heating rate combination of 783.5 °C, and 5 °C/min, respectively. Interaction between temperature and heating rate exerted the strongest and weakest impact on DSC and remaining mass, respectively. The fluorine mainly as the formation of substantial NaF and CaF2 in the residual ash. Besides, the composition and effect of environment of residual solid were evaluated. The ash slagging tendency and its mineral deposition mechanisms were elucidated in terms of turning SPL waste into a benign input to a circular waste utilization.


Assuntos
Resíduos Perigosos , Gerenciamento de Resíduos , Alumínio , Gases , Termogravimetria
12.
Artigo em Inglês | MEDLINE | ID: mdl-34347579

RESUMO

Combustion of High-sulfur oil sludge (OS) blended with CaO can significantly reduce the emission of sulfur gas pollutants, but its combustion and kinetic characteristics need to be further studied. TGA experiments showed the combustion characteristics of OS were significantly changed after adding CaO. As reflected by comprehensive combustion index (S), the combustion performance of OS decreased after adding CaO, and significantly improved with the increase of heating rate. The kinetic parameters of the main combustion process of OS with CaO were calculated by the iso-conversion methods of Friedman, FWO, and Starink, respectively. Kinetic analysis results indicated the energy required for OS combustion with CaO first increased and then decreased with deepening of reaction degree. The thermodynamic parameters of ΔH, ΔG and ΔS were determined on the basis of kinetics. The negative ΔH, positive ΔG, and negative ΔS validated the combustion of OS with CaO was an exothermic and nonspontaneous process.


Assuntos
Calefação , Esgotos , Cinética , Termodinâmica , Termogravimetria
13.
Carbohydr Polym ; 270: 118317, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34364590

RESUMO

Arabinoxylan (AX) and cellulose were extracted from wheat straw, whereas starch was extracted from potato peel. Thereafter, cellulose and starch were esterified with lauric, myristic, palmitic and stearic acids to prepare corresponding cellulose (CFAs) and starch fatty acid esters (SFAs) with DS 2.1-2.8. XRD study revealed remarkable loss of crystallinity in cellulose and starch due to fatty acid esterification. The addition of palmitate and stearate esters of cellulose and starch to AX formed laminar film microstructures which limited water vapor permeability whereas films prepared by blending AX with laurate and myristate esters of starch and cellulose were less effective as water vapor barrier due to their non-layer microstructures. The laminar structures also resulted significant reduction in mechanical strength of the composite films. Furthermore, all AX-CFAs and AX-SFAs films were thermally more stable than native composite films. These films might be used to produce industrially useful coating material for food products.


Assuntos
Celulose/química , Ácidos Graxos/química , Amido/química , Xilanos/química , Esterificação , Ésteres/química , Embalagem de Alimentos/métodos , Humanos , Fenômenos Mecânicos , Microscopia Eletrônica de Varredura/métodos , Permeabilidade , Fenômenos Físicos , Solanum tuberosum/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Vapor , Ácidos Esteáricos/química , Termogravimetria/métodos , Triticum/química , Água/química
14.
Carbohydr Polym ; 270: 118330, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34364592

RESUMO

Based on the gradient distribution of structure and composition in biological cartilage tissue, we designed a gradient hydrogel scaffold by the moving photomask, using chondroitin sulfate and poly (γ-glutamic acid) as crude materials. The hydrogel scaffold had a gradient distribution of cross-linking density, which can be verified from the results of SEM and swelling behavior. Besides, the hydrogel exhibited great viscoelastic, toughness (70% strain), and strength properties (600 kPa). Additionally, the gradient hydrogel's superior cell compatibility was proved through the MTT, live/dead staining assays, and 3D cell culture experiments. Remarkably, the results of in vitro stem cell differentiation experiments showed that the duration of light directly affected the differentiation extent of stem cells, demonstrating that the gradient hydrogel scaffold can better simulate the function of natural cartilage than the homogeneous one. Due to these outstanding characteristics, this gradient hydrogel is a potential scaffold for cartilage tissue engineering.


Assuntos
Cartilagem/citologia , Sulfatos de Condroitina/química , Hidrogéis/química , Ácido Poliglutâmico/análogos & derivados , Células-Tronco/metabolismo , Engenharia Tecidual/métodos , Animais , Cartilagem/metabolismo , Diferenciação Celular , Linhagem Celular , Condrócitos/metabolismo , Camundongos , Microscopia Eletrônica de Varredura/métodos , Ácido Poliglutâmico/química , Reologia/métodos , Termogravimetria/métodos , Tecidos Suporte/química
15.
Sci Total Environ ; 798: 149290, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34340093

RESUMO

The pyrolysis experiment of biomass added to coal gangue was studied by thermogravimetric-Fourier transform infrared spectroscopy-mass spectrometry (TG-FTIR-MS) method. The multi-component reaction model was used to simulate the pyrolysis reaction of coal gangue and biomass. The most suitable model was obtained, and the pyrolysis mechanism was analyzed. According to the two-component reaction model of CG pyrolysis, the decomposition temperature range of components in CG is 340-800 °C and 400-620 °C. The five-component reaction model can well simulate the pyrolysis process of coal gangue and biomass. Meanwhile, the effects of different proportions of biomass in the mixture on the gas products of coal gangue pyrolysis were analyzed. It was found that the addition of biomass to coal gangue could promote the release of gaseous organic matter during pyrolysis. CG75PS25 only has a synergistic effect in the high temperature zone greater than 600 °C. CG25PS75 only has a synergistic effect in a small range of 230-300 °C, and there is an inhibitory effect in other temperature ranges. In general, there is an inhibitory effect between coal gangue and biomass on CO2 formation, which is of positive significance for greenhouse gas emission reduction.


Assuntos
Carvão Mineral , Pirólise , Biomassa , Carvão Mineral/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
16.
Molecules ; 26(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34443314

RESUMO

Despite the common use of salens and hydroxyquinolines as therapeutic and bioactive agents, their metal complexes are still under development. Here, we report the synthesis of novel mixed-ligand metal complexes (MSQ) comprising salen (S), derived from (2,2'-{1,2-ethanediylbis[nitrilo(E) methylylidene]}diphenol, and 8-hydroxyquinoline (Q) with Co(II), Ni(II), Cd(II), Al(III), and La(III). The structures and properties of these MSQ metal complexes were investigated using molar conductivity, melting point, FTIR, 1H NMR, 13C NMR, UV-VIS, mass spectra, and thermal analysis. Quantum calculation, analytical, and experimental measurements seem to suggest the proposed structure of the compounds and its uncommon monobasic tridentate binding mode of salen via phenolic oxygen, azomethine group, and the NH group. The general molecular formula of MSQ metal complexes is [M(S)(Q)(H2O)] for M (II) = Co, Ni, and Cd or [M(S)(Q)(Cl)] and [M(S)(Q)(H2O)]Cl for M(III) = La and Al, respectively. Importantly, all prepared metal complexes were evaluated for their antimicrobial and anticancer activities. The metal complexes exhibited high cytotoxic potency against human breast cancer (MDA-MB231) and liver cancer (Hep-G2) cell lines. Among all MSQ metal complexes, CoSQ and LaSQ produced IC50 values (1.49 and 1.95 µM, respectively) that were comparable to that of cisplatin (1.55 µM) against Hep-G2 cells, whereas CdSQ and LaSQ had best potency against MDA-MB231 with IC50 values of 1.95 and 1.43 µM, respectively. Furthermore, the metal complexes exhibited significant antimicrobial activities against a wide spectrum of both Gram-positive and -negative bacterial and fungal strains. The antibacterial and antifungal efficacies for the MSQ metal complexes, the free S and Q ligands, and the standard drugs gentamycin and ketoconazole decreased in the order AlSQ > LaSQ > CdSQ > gentamycin > NiSQ > CoSQ > Q > S for antibacterial activity, and for antifungal activity followed the trend of LaSQ > AlSQ > CdSQ > ketoconazole > NiSQ > CoSQ > Q > S. Molecular docking studies were performed to investigate the binding of the synthesized compounds with breast cancer oxidoreductase (PDB ID: 3HB5). According to the data obtained, the most probable coordination geometry is octahedral for all the metal complexes. The molecular and electronic structures of the metal complexes were optimized theoretically, and their quantum chemical parameters were calculated. PXRD results for the Cd(II) and La(III) metal complexes indicated that they were crystalline in nature.


Assuntos
Antibacterianos/farmacologia , Complexos de Coordenação/síntese química , Complexos de Coordenação/farmacologia , Teoria da Densidade Funcional , Etilenodiaminas/síntese química , Simulação de Acoplamento Molecular , Oxiquinolina/síntese química , Oxiquinolina/farmacologia , Antibacterianos/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/química , Etilenodiaminas/química , Etilenodiaminas/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Ligantes , Testes de Sensibilidade Microbiana , Conformação Molecular , Oxiquinolina/química , Difração de Pó , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
17.
Molecules ; 26(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34443315

RESUMO

Nanocellulose was extracted from short bast fibers, from hemp (Cannabis sativa L.) plants harvested at seed maturity, non-retted, and mechanically decorticated in a defibering apparatus, giving non-aligned fibers. A chemical pretreatment with NaOH and HCl allowed the removal of most of the non-cellulosic components of the fibers. No bleaching was performed. The chemically pretreated fibers were then refined in a beater and treated with a cellulase enzyme, followed by mechanical defibrillation in an ultrafine friction grinder. The fibers were characterized by microscopy, infrared spectroscopy, thermogravimetric analysis and X-ray diffraction after each step of the process to understand the evolution of their morphology and composition. The obtained nanocellulose suspension was composed of short nanofibrils with widths of 5-12 nm, stacks of nanofibrils with widths of 20-200 nm, and some larger fibers. The crystallinity index was found to increase from 74% for the raw fibers to 80% for the nanocellulose. The nanocellulose retained a yellowish color, indicating the presence of some residual lignin. The properties of the nanopaper prepared with the hemp nanocellulose were similar to those of nanopapers prepared with wood pulp-derived rod-like nanofibrils.


Assuntos
Cannabis/química , Celulose/química , Produtos Agrícolas/química , Nanopartículas/química , Celulose/ultraestrutura , Nanopartículas/ultraestrutura , Tamanho da Partícula , Solventes/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termogravimetria , Difração de Raios X
18.
Bioresour Technol ; 340: 125722, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34385127

RESUMO

The aim of this work was to evaluate the pyrolysis of mustard straw (MS) in a thermogravimetric analyser and in a tubular reactor to recognize its bioenergy capability. The model free methods of Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS) and Vyazovkin were employed for kinetic analysis and Coats-Redfern (CR) method for elucidating the reaction mechanism. Response surface methodology (RSM) with central composite design technique was employed to optimize the pyrolysis process parameters to gain maximum amount of bio-oil. The highest bio-oil yield (44.69%) was obtained at the heating rate of 25 °C/min and at 500 °C under inert condition (N2 gas flow rate = 100 ml/min). Further, FTIR and GCMS analysis of bio-oil revealed the presence of different functional groups and valuable chemicals, whereas physicochemical characterization revealed its fuel characteristic. The results confirmed the suitability of mustard straw as a feed-stock for obtaining a cleaner fuel and value added products.


Assuntos
Mostardeira , Pirólise , Cinética , Termodinâmica , Termogravimetria
19.
Molecules ; 26(16)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34443457

RESUMO

Curcumin extracted from the rhizome of Curcuma Longa has been used in therapeutic preparations for centuries in different parts of the world. However, its bioactivity is limited by chemical instability, water insolubility, low bioavailability, and extensive metabolism. In this study, the coaxial electrospinning technique was used to produce both poly (ε-caprolactone) (PCL)-curcumin and core-shell nanofibers composed of PCL and curcumin in the core and poly (lactic acid) (PLA) in the shell. Morphology and physical properties, as well as the release of curcumin were studied and compared with neat PCL, showing the formation of randomly oriented, defect-free cylindrical fibers with a narrow distribution of the dimensions. The antibacterial and antibiofilm potential, including the capacity to interfere with the quorum-sensing mechanism, was evaluated on Pseudomonas aeruginosa PAO1, and Streptococcus mutans, two opportunistic pathogenic bacteria frequently associated with infections. The reported results demonstrated the ability of the Curcumin-loading membranes to inhibit both PAO1 and S. mutans biofilm growth and activity, thus representing a promising solution for the prevention of biofilm-associated infections. Moreover, the high biocompatibility and the ability to control the oxidative stress of damaged tissue, make the synthesized membranes useful as scaffolds in tissue engineering regeneration, helping to accelerate the healing process.


Assuntos
Anti-Infecciosos/farmacologia , Biofilmes , Curcumina/farmacologia , Infecções/microbiologia , Nanofibras/química , Engenharia Tecidual , Biofilmes/efeitos dos fármacos , Compostos de Bifenilo/química , Morte Celular/efeitos dos fármacos , Linhagem Celular , Liberação Controlada de Fármacos , Sequestradores de Radicais Livres/farmacologia , Humanos , Cinética , Testes de Sensibilidade Microbiana , Picratos/química , Poliésteres/química , Percepção de Quorum/efeitos dos fármacos , Termogravimetria
20.
Int J Mol Sci ; 22(16)2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34445122

RESUMO

Seven inorganic salts containing N-phenylbiguanide as a prospective organic molecular carrier of nonlinear optical properties were prepared and studied within our research of novel hydrogen-bonded materials for nonlinear optics (NLO). All seven salts, namely N-phenylbiguanidium(1+) nitrate (C2/c), N-phenylbiguanidium(1+) perchlorate (P-1), N-phenylbiguanidium(1+) hydrogen carbonate (P21/c), bis(N-phenylbiguanidium(1+)) sulfate (C2), bis(N-phenylbiguanidium(1+)) hydrogen phosphate sesquihydrate (P-1), bis(N-phenylbiguanidium(1+)) phosphite (P21), and bis(N-phenylbiguanidium(1+)) phosphite dihydrate (P21/n), were characterised by X-ray diffraction (powder and single-crystal X-ray diffraction) and by vibrational spectroscopy (FTIR and Raman). Two salts with non-centrosymmetric crystal structures-bis(N-phenylbiguanidium(1+)) sulfate and bis(N-phenylbiguanidium(1+)) phosphite-were further studied to examine their linear and nonlinear optical properties using experimental and computational methods. As a highly SHG-efficient and phase-matchable material transparent down to 320 nm and thermally stable to 483 K, bis(N-phenylbiguanidium(1+)) sulfate is a promising novel candidate for NLO.


Assuntos
Sais/química , Cristalização/métodos , Cristalografia por Raios X/métodos , Óptica e Fotônica/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Análise Espectral Raman/métodos , Termogravimetria/métodos , Difração de Raios X/métodos
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