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1.
ACS Omega ; 9(2): 2770-2782, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38250433

RESUMO

Herein, we report a solvent-less, straightforward, and facile mechanochemical technique to synthesize nanocomposites of Ag2O nanoparticles-doped MnO2, which is further codoped with nitrogen-doped graphene (N-DG) [i.e., (X %)N-DG/MnO2-(1% Ag2O)] using physical milling of separately prepared N-DG and Ag2O NPs-MnO2 annealed at 400 °C over an eco-friendly ball-mill process. To assess the efficiency in terms of catalytic performance of the nanocomposites, selective oxidation of benzyl alcohol (BlOH) to benzaldehyde (BlCHO) is selected as a substrate model with an eco-friendly oxidizing agent (O2 molecule) and without any requirements for the addition of any harmful additives or bases. Various nanocomposites were prepared by varying the amount of N-DG in the composite, and the results obtained highlighted the function of N-DG in the catalyst system when they are compared with the catalyst MnO2-(1% Ag2O) [i.e., undoped catalyst] and MnO2-(1% Ag2O) codoped with different graphene dopants such as GRO and H-RG for alcohol oxidation transformation. The effects of various catalytic factors are systematically evaluated to optimize reaction conditions. The N-DG/MnO2-(1% Ag2O) catalyst exhibits premium specific activity (16.0 mmol/h/g) with 100% BlOH conversion and <99.9% BlCHO selectivity within a very short interval. The mechanochemically prepared N-DG-based nanocomposite displayed higher catalytic efficacy than that of the MnO2-(1% Ag2O) catalyst without the graphene dopant, which is N-DG in this study. A wide array of aromatic, heterocyclic, allylic, primary, secondary, and aliphatic alcohols have been selectively converted to respective ketones and aldehydes with full convertibility without further oxidation to acids over N-DG/MnO2-(1% Ag2O). Interestingly, it is also found that the N-DG/MnO2-(1% Ag2O) can be efficiently reused up to six times without a noteworthy decline in its effectiveness. The prepared nanocomposites were characterized using various analytical, microscopic, and spectroscopic techniques such as X-ray diffraction, thermogravimetric analysis, Fourier-transform infrared spectroscopy, Raman, field emission scanning electron microscopy, and Brunauer-Emmett-Teller.

2.
Braz. j. biol ; 842024.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1469398

RESUMO

Abstract Liver fibrosis is initial stage of any chronic liver disease and its end stage is develops into cirrhosis. Chronic liver diseases are a crucial global health issue and the cause of approximately 2 million deaths per year worldwide. Cirrhosis is currently the 11th most common cause of death globally. Mesenchymal stem cell (MSCs) treatment is the best way to treat acute and chronic liver disease. The aim of this study is to improve the therapeutic potential of MSCs combined with melatonin (MLT) to overcome CCl4-induced liver fibrosis and also investigate the individual impact of melatonin and MSCs against CCl4-induced liver impairment in animal model. Female BALB/c mice were used as CCL4-induced liver fibrotic animal model. Five groups of animal model were made; negative control, Positive control, CCl4+MSCs treated group, CCl4+MLT treated group and CCl4+MSCs+MLT treated group. Cultured MSCs from mice bone marrow were transplanted to CCl4-induced liver injured mice model, individually as well as together with melatonin. Two weeks after MSCs and MLT administration, all groups of mice were sacrificed for examination. Morphological and Histopathological results showed that combined therapy of MSCs+MLT showed substantial beneficial impact on CCl4-induced liver injured model, compared with MSCs and MLT individually. Biochemically, considerable reduction was observed in serum bilirubin and ALT levels of MLT+MSC treated mice, compared to other groups. PCR results shown down-regulation of Bax and up-regulation of Bcl-xl and Albumin, confirm a significant therapeutic effect of MSCs+MLT on CCI4-induced liver fibrosis. From the results, it is concluded that combined therapy of MSCs and MLT show strong therapeutic effect on CCL4-induced liver fibrosis, compared with MSCs and MLT individually.


Resumo A fibrose hepática é a fase inicial de qualquer doença hepática crônica, e em sua fase final desenvolve-se para cirrose. As doenças hepáticas crônicas são uma questão de saúde global crucial e a causa de aproximadamente 2 milhões de mortes por ano em todo o mundo. A cirrose, hoje em dia, é a 11ª causa mais comum de morte globalmente. O tratamento da célula-tronco mesenquimal (MSCs) é uma maneira eletiva de tratar a doença hepática aguda e crônica. O objetivo deste estudo é melhorar o potencial terapêutico dos MSCs combinados com a melatonina (MLT) para superar a fibrose hepática induzida por CCl4 e também investigar o impacto individual da melatonina e MSCs contra o comprometimento do fígado induzido por CCl4 no modelo animal. Os ratos BALB / C fêmeas foram usados como modelo de animal fibrótico de fígado induzido por CCl4. Cinco grupos de modelo animal foram feitos: Controle Negativo, Controle Positivo, CCl4 + MSCs Tratados Grupo, Grupo Tratado CCl4 + MLT e Grupo Tratado CCl4 + MSCs + MLT. MSCs cultivados da medula óssea dos ratos foram transplantados para o modelo de camundongos de fígado induzido por CCl4, individualmente, bem como em conjunto com a melatonina. Duas semanas após a administração MSCs e MLT, todos os grupos de camundongos foram sacrificados para o exame. Os resultados morfológicos e histopatológicos mostraram que a terapia combinada do MSCs + MLT mostrou impacto benéfico substancial no modelo ferido no fígado induzido pelo CCl4, em comparação com o MSCs e o MLT individualmente. A redução bioquimicamente considerável foi observada em bilirrubina sérica e níveis ALT de ratinhos tratados com MLT + MSCs, em comparação com outros grupos. Os resultados de PCR mostraram regulação negativa do BAX e regulação positiva do BCL-XL e da albumina, confirmando um efeito terapêutico significativo do MSCs + MLT na fibrose hepática induzida por CCl4. Dos resultados, conclui-se que a terapia combinada de MSCs e MLT mostram um forte efeito terapêutico na fibrose hepática induzida por CCl4, em comparação com MSCs e MLT individualmente.

3.
Braz. j. biol ; 84: e253061, 2024. tab, graf, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1364520

RESUMO

Liver fibrosis is initial stage of any chronic liver disease and its end stage is develops into cirrhosis. Chronic liver diseases are a crucial global health issue and the cause of approximately 2 million deaths per year worldwide. Cirrhosis is currently the 11th most common cause of death globally. Mesenchymal stem cell (MSCs) treatment is the best way to treat acute and chronic liver disease. The aim of this study is to improve the therapeutic potential of MSCs combined with melatonin (MLT) to overcome CCl4-induced liver fibrosis and also investigate the individual impact of melatonin and MSCs against CCl4-induced liver impairment in animal model. Female BALB/c mice were used as CCL4-induced liver fibrotic animal model. Five groups of animal model were made; negative control, Positive control, CCl4+MSCs treated group, CCl4+MLT treated group and CCl4+MSCs+MLT treated group. Cultured MSCs from mice bone marrow were transplanted to CCl4-induced liver injured mice model, individually as well as together with melatonin. Two weeks after MSCs and MLT administration, all groups of mice were sacrificed for examination. Morphological and Histopathological results showed that combined therapy of MSCs+MLT showed substantial beneficial impact on CCl4-induced liver injured model, compared with MSCs and MLT individually. Biochemically, considerable reduction was observed in serum bilirubin and ALT levels of MLT+MSC treated mice, compared to other groups. PCR results shown down-regulation of Bax and up-regulation of Bcl-xl and Albumin, confirm a significant therapeutic effect of MSCs+MLT on CCI4-induced liver fibrosis. From the results, it is concluded that combined therapy of MSCs and MLT show strong therapeutic effect on CCL4-induced liver fibrosis, compared with MSCs and MLT individually.


A fibrose hepática é a fase inicial de qualquer doença hepática crônica, e em sua fase final desenvolve-se para cirrose. As doenças hepáticas crônicas são uma questão de saúde global crucial e a causa de aproximadamente 2 milhões de mortes por ano em todo o mundo. A cirrose, hoje em dia, é a 11ª causa mais comum de morte globalmente. O tratamento da célula-tronco mesenquimal (MSCs) é uma maneira eletiva de tratar a doença hepática aguda e crônica. O objetivo deste estudo é melhorar o potencial terapêutico dos MSCs combinados com a melatonina (MLT) para superar a fibrose hepática induzida por CCl4 e também investigar o impacto individual da melatonina e MSCs contra o comprometimento do fígado induzido por CCl4 no modelo animal. Os ratos BALB / C fêmeas foram usados ​​como modelo de animal fibrótico de fígado induzido por CCl4. Cinco grupos de modelo animal foram feitos: Controle Negativo, Controle Positivo, CCl4 + MSCs Tratados Grupo, Grupo Tratado CCl4 + MLT e Grupo Tratado CCl4 + MSCs + MLT. MSCs cultivados da medula óssea dos ratos foram transplantados para o modelo de camundongos de fígado induzido por CCl4, individualmente, bem como em conjunto com a melatonina. Duas semanas após a administração MSCs e MLT, todos os grupos de camundongos foram sacrificados para o exame. Os resultados morfológicos e histopatológicos mostraram que a terapia combinada do MSCs + MLT mostrou impacto benéfico substancial no modelo ferido no fígado induzido pelo CCl4, em comparação com o MSCs e o MLT individualmente. A redução bioquimicamente considerável foi observada em bilirrubina sérica e níveis ALT de ratinhos tratados com MLT + MSCs, em comparação com outros grupos. Os resultados de PCR mostraram regulação negativa do BAX e regulação positiva do BCL-XL e da albumina, confirmando um efeito terapêutico significativo do MSCs + MLT na fibrose hepática induzida por CCl4. Dos resultados, conclui-se que a terapia combinada de MSCs e MLT mostram um forte efeito terapêutico na fibrose hepática induzida por CCl4, em comparação com MSCs e MLT individualmente.


Assuntos
Ratos , Células-Tronco , Fibrose , Fígado , Hepatopatias , Melatonina
4.
ACS Omega ; 8(22): 20042-20055, 2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37305313

RESUMO

This work reports an environmentally friendly and economically feasible green synthesis of monometallic oxides (SnO2 and WO3) and their corresponding mixed metal oxide (SnO2/WO3-x) nanostructures from the aqueous Psidium guajava leaf extract for light-driven catalytic degradation of a major industrial contaminant, methylene blue (MB). P. guajava is a rich source of polyphenols that acts as a bio-reductant as well as a capping agent in the synthesis of nanostructures. The chemical composition and redox behavior of the green extract were investigated by liquid chromatography-mass spectrometry and cyclic voltammetry, respectively. Results acquired by X-ray diffraction and Fourier transform infrared spectroscopy confirm the successful formation of crystalline monometallic oxides (SnO2 and WO3) and bimetallic SnO2/WO3-x hetero-nanostructures capped with polyphenols. The structural and morphological aspects of the synthesized nanostructures were analyzed by transmission electron microscopy and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. Photocatalytic activity of the synthesized monometallic and hetero-nanostructures was investigated for the degradation of MB dye under UV light irradiation. Results indicate a higher photocatalytic degradation efficiency for mixed metal oxide nanostructures (93.5%) as compared to pristine monometallic oxides SnO2 (35.7%) and WO3 (74.5%). The hetero-metal oxide nanostructures prove to be better photocatalysts with reusability up to 3 cycles without any loss in degradation efficiency or stability. The enhanced photocatalytic efficiency is attributed to a synergistic effect in the hetero-nanostructures, efficient charge transportation, extended light absorption, and increased adsorption of dye due to the enlarged specific surface area.

5.
Braz. j. biol ; 83: 1-8, 2023. graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1468842

RESUMO

Poultry industry is expanding rapidly and producing million tons of feather waste annually. Massive production of keratinaceous byproducts in the form of industrial wastes throughout the world necessitates its justified utilization. Chemical treatment of keratin waste is proclaimed as an eco-destructive approach by various researchers since it generates secondary pollutants. Keratinase released by a variety of microbes (bacteria and fungi) can be used for the effective treatment of keratin waste. Microbial degradation of keratin waste is an emerging and eco-friendly approach and offers dual benefits, i.e., treatment of recalcitrant pollutant (keratin) and procurement of a commercially important enzyme (keratinase). This study involves the isolation, characterization, and potential utility of fungal species for the degradation of chicken-feather waste through submerged and solid-state fermentation. The isolated fungus was identified and characterized as Aspergillus (A.) flavus. In a trial of 30 days, it was appeared that 74 and 8% feather weight was reduced through sub-merged and solid-state fermentation, respectively by A. flavus. The pH of the growth media in submerged fermentation was changed from 4.8 to 8.35. The exploited application of keratinolytic microbes is, therefore, recommended for the treatment of keratinaceous wastes to achieve dual benefits of remediation.


A indústria avícola está se expandindo rapidamente e produzindo milhões de toneladas de resíduos de penas anualmente. A produção massiva de subprodutos queratinosos na forma de resíduos agrícolas e industriais em todo o mundo exige sua utilização justificada. O tratamento químico de resíduos de queratina é proclamado como uma abordagem ecodestrutiva por vários pesquisadores, uma vez que gera poluentes secundários. A queratinase liberada por uma variedade de micróbios (bactérias e fungos) pode ser usada para o tratamento eficaz de resíduos de queratina. A degradação microbiana de resíduos de queratina é uma abordagem emergente e ecológica e oferece benefícios duplos, ou seja, tratamento de poluente recalcitrante (queratina) e obtenção de uma enzima comercialmente importante (queratinase). Este estudo envolve o isolamento, caracterização e utilidade potencial de espécies de fungos para a degradação de resíduos de penas de frango por meio da fermentação submersa e em estado sólido. O fungo isolado foi identificado e caracterizado como Aspergillus (A.) flavus. Em um ensaio de 30 dias, constatou-se que 74% e 8% do peso das penas foram reduzidos por A. flavus, respectivamente, por meio da fermentação submersa e em estado sólido. O pH do meio de crescimento em fermentação submersa foi alterado de 4,8 para 8,35. A aplicação explorada de micróbios queratinolíticos é, portanto, recomendada para o tratamento de resíduos ceratinosos para obter benefícios duplos de remediação.


Assuntos
Aspergillus flavus/isolamento & purificação , Biotransformação , Queratinas/análise , Queratinas/toxicidade
6.
Braz. j. biol ; 832023.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1469058

RESUMO

Abstract Poultry industry is expanding rapidly and producing million tons of feather waste annually. Massive production of keratinaceous byproducts in the form of industrial wastes throughout the world necessitates its justified utilization. Chemical treatment of keratin waste is proclaimed as an eco-destructive approach by various researchers since it generates secondary pollutants. Keratinase released by a variety of microbes (bacteria and fungi) can be used for the effective treatment of keratin waste. Microbial degradation of keratin waste is an emerging and eco-friendly approach and offers dual benefits, i.e., treatment of recalcitrant pollutant (keratin) and procurement of a commercially important enzyme (keratinase). This study involves the isolation, characterization, and potential utility of fungal species for the degradation of chicken-feather waste through submerged and solid-state fermentation. The isolated fungus was identified and characterized as Aspergillus (A.) flavus. In a trial of 30 days, it was appeared that 74 and 8% feather weight was reduced through sub-merged and solid-state fermentation, respectively by A. flavus. The pH of the growth media in submerged fermentation was changed from 4.8 to 8.35. The exploited application of keratinolytic microbes is, therefore, recommended for the treatment of keratinaceous wastes to achieve dual benefits of remediation.


Resumo A indústria avícola está se expandindo rapidamente e produzindo milhões de toneladas de resíduos de penas anualmente. A produção massiva de subprodutos queratinosos na forma de resíduos agrícolas e industriais em todo o mundo exige sua utilização justificada. O tratamento químico de resíduos de queratina é proclamado como uma abordagem ecodestrutiva por vários pesquisadores, uma vez que gera poluentes secundários. A queratinase liberada por uma variedade de micróbios (bactérias e fungos) pode ser usada para o tratamento eficaz de resíduos de queratina. A degradação microbiana de resíduos de queratina é uma abordagem emergente e ecológica e oferece benefícios duplos, ou seja, tratamento de poluente recalcitrante (queratina) e obtenção de uma enzima comercialmente importante (queratinase). Este estudo envolve o isolamento, caracterização e utilidade potencial de espécies de fungos para a degradação de resíduos de penas de frango por meio da fermentação submersa e em estado sólido. O fungo isolado foi identificado e caracterizado como Aspergillus (A.) flavus. Em um ensaio de 30 dias, constatou-se que 74% e 8% do peso das penas foram reduzidos por A. flavus, respectivamente, por meio da fermentação submersa e em estado sólido. O pH do meio de crescimento em fermentação submersa foi alterado de 4,8 para 8,35. A aplicação explorada de micróbios queratinolíticos é, portanto, recomendada para o tratamento de resíduos ceratinosos para obter benefícios duplos de remediação.

7.
Braz. j. biol ; 83: e246389, 2023. graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1285638

RESUMO

Abstract Poultry industry is expanding rapidly and producing million tons of feather waste annually. Massive production of keratinaceous byproducts in the form of industrial wastes throughout the world necessitates its justified utilization. Chemical treatment of keratin waste is proclaimed as an eco-destructive approach by various researchers since it generates secondary pollutants. Keratinase released by a variety of microbes (bacteria and fungi) can be used for the effective treatment of keratin waste. Microbial degradation of keratin waste is an emerging and eco-friendly approach and offers dual benefits, i.e., treatment of recalcitrant pollutant (keratin) and procurement of a commercially important enzyme (keratinase). This study involves the isolation, characterization, and potential utility of fungal species for the degradation of chicken-feather waste through submerged and solid-state fermentation. The isolated fungus was identified and characterized as Aspergillus (A.) flavus. In a trial of 30 days, it was appeared that 74 and 8% feather weight was reduced through sub-merged and solid-state fermentation, respectively by A. flavus. The pH of the growth media in submerged fermentation was changed from 4.8 to 8.35. The exploited application of keratinolytic microbes is, therefore, recommended for the treatment of keratinaceous wastes to achieve dual benefits of remediation.


Resumo A indústria avícola está se expandindo rapidamente e produzindo milhões de toneladas de resíduos de penas anualmente. A produção massiva de subprodutos queratinosos na forma de resíduos agrícolas e industriais em todo o mundo exige sua utilização justificada. O tratamento químico de resíduos de queratina é proclamado como uma abordagem ecodestrutiva por vários pesquisadores, uma vez que gera poluentes secundários. A queratinase liberada por uma variedade de micróbios (bactérias e fungos) pode ser usada para o tratamento eficaz de resíduos de queratina. A degradação microbiana de resíduos de queratina é uma abordagem emergente e ecológica e oferece benefícios duplos, ou seja, tratamento de poluente recalcitrante (queratina) e obtenção de uma enzima comercialmente importante (queratinase). Este estudo envolve o isolamento, caracterização e utilidade potencial de espécies de fungos para a degradação de resíduos de penas de frango por meio da fermentação submersa e em estado sólido. O fungo isolado foi identificado e caracterizado como Aspergillus (A.) flavus. Em um ensaio de 30 dias, constatou-se que 74% e 8% do peso das penas foram reduzidos por A. flavus, respectivamente, por meio da fermentação submersa e em estado sólido. O pH do meio de crescimento em fermentação submersa foi alterado de 4,8 para 8,35. A aplicação explorada de micróbios queratinolíticos é, portanto, recomendada para o tratamento de resíduos ceratinosos para obter benefícios duplos de remediação.


Assuntos
Animais , Galinhas , Plumas , Fermentação , Fungos , Resíduos Industriais , Queratinas/metabolismo
8.
Front Chem ; 10: 872366, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35572099

RESUMO

The formation of a C-C bond through Mizoroki-Heck cross-coupling reactions in water with efficient heterogeneous catalysts is a challenging task. In this current study, a highly reduced graphene oxide (HRG) immobilized palladium (Pd) nanoparticle based catalyst (HRG-Py-Pd) is used to catalyze Mizoroki-Heck cross-coupling reactions in water. During the preparation of the catalyst, amino pyrene is used as a smart functionalizing ligand, which offered chemically specific binding sites for the effective and homogeneous nucleation of Pd NPs on the surface of HRG, which significantly enhanced the physical stability and dispersibility of the resulting catalyst in an aqueous medium. Microscopic analysis of the catalyst revealed a uniform distribution of ultrafine Pd NPs on a solid support. The catalytic properties of HRG-Py-Pd are tested towards the Mizoroki-Heck cross-coupling reactions of various aryl halides with acrylic acid in an aqueous medium. Furthermore, the catalytic efficacy of HRG-Py-Pd is also compared with its non-functionalized counterparts such as HRG-Pd and pristine Pd NPs (Pd-NPs). Using the HRG-Py-Pd nanocatalyst, the highest conversion of 99% is achieved in the coupling reaction of 4-bromoanisol and acrylic acid in an aqueous solution in a relatively short period of time (3 h), with less quantity of catalyst (3 mg). Comparatively, pristine Pd NPs delivered lower conversion (∼92%) for the same reaction required a long reaction time and a large amount of catalyst (5.3 mg). Indeed, the conversion of the reaction further decreased to just 40% when 3 mg of Pd-NPs was used which was sufficient to produce 99% conversion in the case of HRG-Py-Pd. On the other hand, HRG-Pd did not deliver any conversion and was ineffective even after using a high amount of catalyst and a longer reaction time. The inability of the HRG-Pd to promote coupling reactions can be attributed to the agglomeration of Pd NPs which reduced the dispersion quality of the catalyst in water. Therefore, the high aqueous stability of HRG-Py-Pd due to smart functionalization can be utilized to perform other organic transformations in water which was otherwise not possible.

9.
Braz J Biol ; 84: e253061, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35293541

RESUMO

Liver fibrosis is initial stage of any chronic liver disease and its end stage is develops into cirrhosis. Chronic liver diseases are a crucial global health issue and the cause of approximately 2 million deaths per year worldwide. Cirrhosis is currently the 11th most common cause of death globally. Mesenchymal stem cell (MSCs) treatment is the best way to treat acute and chronic liver disease. The aim of this study is to improve the therapeutic potential of MSCs combined with melatonin (MLT) to overcome CCl4-induced liver fibrosis and also investigate the individual impact of melatonin and MSCs against CCl4-induced liver impairment in animal model. Female BALB/c mice were used as CCL4-induced liver fibrotic animal model. Five groups of animal model were made; negative control, Positive control, CCl4+MSCs treated group, CCl4+MLT treated group and CCl4+MSCs+MLT treated group. Cultured MSCs from mice bone marrow were transplanted to CCl4-induced liver injured mice model, individually as well as together with melatonin. Two weeks after MSCs and MLT administration, all groups of mice were sacrificed for examination. Morphological and Histopathological results showed that combined therapy of MSCs+MLT showed substantial beneficial impact on CCl4-induced liver injured model, compared with MSCs and MLT individually. Biochemically, considerable reduction was observed in serum bilirubin and ALT levels of MLT+MSC treated mice, compared to other groups. PCR results shown down-regulation of Bax and up-regulation of Bcl-xl and Albumin, confirm a significant therapeutic effect of MSCs+MLT on CCI4-induced liver fibrosis. From the results, it is concluded that combined therapy of MSCs and MLT show strong therapeutic effect on CCL4-induced liver fibrosis, compared with MSCs and MLT individually.


Assuntos
Melatonina , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Animais , Tetracloreto de Carbono/metabolismo , Tetracloreto de Carbono/toxicidade , Feminino , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/metabolismo , Cirrose Hepática/terapia , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/patologia , Camundongos , Camundongos Endogâmicos BALB C
10.
Chem Rec ; 22(7): e202100274, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35103379

RESUMO

Graphene-based nanocomposites with inorganic (metal and metal oxide) nanoparticles leads to materials with high catalytic activity for a variety of chemical transformations. Graphene and its derivatives such as graphene oxide, highly reduced graphene oxide, or nitrogen-doped graphene are excellent support materials due to their high surface area, their extended π-system, and variable functionalities for effective chemical interactions to fabricate nanocomposites. The ability to fine-tune the surface composition for desired functionalities enhances the versatility of graphene-based nanocomposites in catalysis. This review summarizes the preparation of graphene/inorganic NPs based nanocomposites and their use in catalytic applications. We discuss the large-scale synthesis of graphene-based nanomaterials. We have also highlighted the interfacial electronic communication between graphene/inorganic nanoparticles and other factors resulting in increased catalytic efficiencies.

11.
ACS Omega ; 7(6): 4812-4820, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-35187301

RESUMO

Eco-friendly approaches for the preparation of nanomaterials have recently attracted considerable attention of scientific community due to rising environmental distresses. The aim of the current study is to prepare titanium dioxide (TiO2) nanoparticles (NPs) using an eco-friendly approach and investigate their performance for the photocatalytic degradation of hazardous organic dyes. For this, TiO2 NPs were prepared by using the aqueous extract of the Pulicaria undulata (L.) plant in a single step at room temperature. Energy-dispersive X-ray spectroscopy established the presence of both titanium and oxygen in the sample. X-ray diffraction revealed the formation of crystalline, anatase-phase TiO2 NPs. On the other hand, transmission election microscopy confirmed the formation of spherical shaped NPs. The presence of residual phytomolecules as capping/stabilization agents is confirmed by UV-vis analysis and Fourier-transform Infrared spectroscopy. Indeed, in the presence of P. undulata, the anatase phase of TiO2 is stabilized at a significantly lower temperature (100 °C) without using any external stabilizing agent. The green synthesized TiO2 NPs were used to investigate their potential for the photocatalytic degradation of hazardous organic dyes including methylene blue and methyl orange under UV-visible light irradiation. Due to the small size and high dispersion of NPs, almost complete degradation (∼95%) was achieved in a short period of time (between 1 and 2 h). No significant difference in the photocatalytic activity of the TiO2 NPs was observed even after repeated use (three times) of the photocatalyst. Overall, the green synthesized TiO2 NPs exhibited considerable potential for fast and eco-friendly removal of harmful organic dyes.

12.
Materials (Basel) ; 14(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34206999

RESUMO

The conventional physical and chemical synthetic methods for the preparation of metal nanoparticles have disadvantages as they use expensive equipment and hazardous chemicals which limit their applications for biomedical purposes, and are not environment friendly. However, for the synthesis of biocompatible nanomaterials, plant-based techniques are eco-friendly and easy to handle. Herein a simple, single-step biosynthesis of gold nanoparticles using aqueous extracts of Nigella sativa (NSE) and Zingiber officinale (GE) as a reducing and capping agent has been demonstrated. The formation of gold nanoparticles (Au NPs) was confirmed by X-ray diffraction, UV-Vis, and EDS spectroscopies. Spectroscopic and chromatographic analysis of GE and NSE revealed the presence of bioactive phytochemical constituents, such as gingerol, thymoquinone, etc., which successfully conjugated the surface of resulting Au NPs. TEM analysis indicated the formation of smaller-sized, less-aggregated, spherical-shaped Au NPs both in the case of GE (~9 nm) and NSE (~11 nm). To study the effect of the concentration of the extracts on the quality of resulting NPs and their anticancer properties, three different samples of Au NPs were prepared from each extract by varying the concentration of extracts while keeping the amount of precursor constant. In both cases, high-quality, spherical-shaped NPs were obtained, only at a high concentration of the extract, whereas at lower concentrations, larger-sized, irregular-shaped NPs were formed. Furthermore, the as-prepared Au NPs were evaluated for the anticancer properties against two different cell lines including MDA-MB-231 (breast cancer) and HCT 116 (colorectal cancer) cell lines. GE-conjugated Au NPs obtained by using a high concentration of the extract demonstrated superior anticancer properties when compared to NSE-conjugated counterparts.

13.
Braz J Biol ; 83: e246389, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34320050

RESUMO

Poultry industry is expanding rapidly and producing million tons of feather waste annually. Massive production of keratinaceous byproducts in the form of industrial wastes throughout the world necessitates its justified utilization. Chemical treatment of keratin waste is proclaimed as an eco-destructive approach by various researchers since it generates secondary pollutants. Keratinase released by a variety of microbes (bacteria and fungi) can be used for the effective treatment of keratin waste. Microbial degradation of keratin waste is an emerging and eco-friendly approach and offers dual benefits, i.e., treatment of recalcitrant pollutant (keratin) and procurement of a commercially important enzyme (keratinase). This study involves the isolation, characterization, and potential utility of fungal species for the degradation of chicken-feather waste through submerged and solid-state fermentation. The isolated fungus was identified and characterized as Aspergillus (A.) flavus. In a trial of 30 days, it was appeared that 74 and 8% feather weight was reduced through sub-merged and solid-state fermentation, respectively by A. flavus. The pH of the growth media in submerged fermentation was changed from 4.8 to 8.35. The exploited application of keratinolytic microbes is, therefore, recommended for the treatment of keratinaceous wastes to achieve dual benefits of remediation.


Assuntos
Galinhas , Plumas , Animais , Fermentação , Fungos , Resíduos Industriais , Queratinas/metabolismo
14.
ACS Omega ; 6(23): 15147-15155, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34151094

RESUMO

Graphene nanocomposites have gained significant interest in a variety of biological applications due to their unique properties. Herein, we have studied the apoptosis-inducing ability and anticancer properties of functionalized highly reduced graphene oxide (HRG) and gold nanoparticles (Au NPs)-based nanocomposites (AP-HRG-Au). Samples were prepared under facile conditions via simple stirring and ultrasonication. All the samples were tested for their anticancer properties against different human cancer cell lines including lung (A549), liver (HepG2), and breast (MCF-7) cancer cells using doxorubicin as a positive control. In order to enhance the solubility and bioavailability of the sample, HRG was functionalized with 1-aminopyrene (1-AP) as a stabilizing ligand. The ligand also facilitated the homogeneous growth of Au NPs on the surface of HRG by offering chemically specific binding sites. The synthesis of nanocomposites and the surface functionalization of HRG were confirmed by UV-Vis, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The structure and morphology of the as-prepared nanocomposites were established by high-resolution transmission electron microscopy. Because of the functionalization, the AP-HRG-Au nanocomposite exhibited enhanced physical stability and high dispersibility. A comparative anticancer study of pristine HRG, nonfunctionalized HRG-Au, and 1-AP-functionalized AP-HRG-Au nanocomposites revealed the enhanced apoptosis ability of functionalized nanocomposites compared to the nonfunctionalized sample, whereas the pristine HRG did not show any anticancer ability against all tested cell lines. Both HRG-Au and AP-HRG-Au have induced a concentration-dependent reduction in cell viability in all tested cell lines after 48 h of exposure, with a significantly higher response in MCF-7 cells compared to the remaining cells. Therefore, MCF-7 cells were selected to perform detailed investigations using apoptosis assay, cell cycle analysis, and reactive oxygen species measurements. These results suggest that AP-HRG-Au induces enhanced apoptosis in human breast cancer cells.

15.
Saudi J Biol Sci ; 28(2): 1196-1202, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33613047

RESUMO

Due to their inexpensive and eco-friendly nature, and existence of manganese in various oxidation states and their natural abundance have attained significant attention for the formation of Mn3O4 nanoparticles (Mn3O4 NPs). Herein, we report the preparation of Mn3O4 nanoparticles using manganese nitrate as a precursor material by utilization of a precipitation technique. The as-prepared Mn3O4 nanoparticles (Mn3O4 NPs) were characterized by using X-ray powder diffraction (XRD), UV-Visible spectroscopy (UV-Vis), High-Resolution Transmission electron microscopy (HRTEM), Field emission scanning electron microscopy (FESEM), Thermal gravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FT-IR). The antimicrobial properties of the as-synthesized Mn3O4 nanoparticles were investigated against numerous bacterial and fungal strains including S. aureus, E. coli, B. subtilis, P. aeruginosa, A. flavus and C. albicans. The Mn3O4 NPs inhibited the growth of S. aureus with a minimum inhibitory concentration (MIC) of 40 µg/ml and C. albicans with a MIC of 15 µg/ml. Furthermore, the Mn3O4 NPs anti-cancer activity was examined using MTT essay against A549 lung and MCF-7 breast cancer cell lines. The Mn3O4 NPs revealed significant activity against the examined cancer cell lines A549 and MCF-7. The IC50 values of Mn3O4 NPs with A549 cell line was found at concentration of 98 µg/mL and MCF-7 cell line was found at concentration of 25 µg/mL.

16.
Molecules ; 25(21)2020 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-33138289

RESUMO

Catalysts of 10% Ni, supported on promoted alumina, were used to accomplish the partial oxidation of methane. The alumina support was doped with oxides of Mo, Mg, Ti and Y. An incipient wetness impregnation technique was used to synthesize the catalysts. The physicochemical properties of the catalysts were described by XRD, H2-TPR (temperature programmed reduction), BET, TGA, CO2-TPD (temperature-programmed desorption) and Raman. The characterization results denoted that Ni has a strong interaction with the support. The TGA investigation of spent catalysts displayed the anticoking enhancement of the promoters. The impact of the support promoters on the catalyst stability, methane conversion and H2 yield was inspected. Stability tests were done for 460 min. The H2 yields were 76 and 60% and the CH4 conversions were 67 and 92%, respectively, over Ni/Al2O3+Mg, when the reaction temperatures were 550 and 650 °C, respectively. The performance of the present work was compared to relevant findings in the literature.


Assuntos
Compostos de Alumínio/química , Manganês/química , Metano/química , Molibdênio/química , Níquel/química , Titânio/química , Ítrio/química , Catálise , Oxirredução
17.
Nanomaterials (Basel) ; 10(9)2020 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-32962292

RESUMO

Plant extract of Pulicaria undulata (L.) was used as both reducing agent and stabilizing ligand for the rapid and green synthesis of gold (Au), silver (Ag), and gold-silver (Au-Ag) bimetallic (phase segregated/alloy) nanoparticles (NPs). These nanoparticles with different morphologies were prepared in two hours by stirring corresponding metal precursors in the aqueous solution of the plant extracts at ambient temperature. To infer the role of concentration of plant extract on the composition and morphology of NPs, we designed two different sets of experiments, namely (i) low concentration (LC) and (ii) high concentration (HC) of plant extract. In the case of using low concentration of the plant extract, irregular shaped Au, Ag, or phase segregated Au-Ag bimetallic NPs were obtained, whereas the use of higher concentrations of the plant extract resulted in the formation of spherical Au, Ag, and Au-Ag alloy NPs. The as-prepared Au, Ag, and Au-Ag bimetallic NPs showed morphology and composition dependent catalytic activity for the reduction of 4-nitrophenol (4-NPh) to 4-aminophenol (4-APh) in the presence of NaBH4. The bimetallic Au-Ag alloy NPs showed the highest catalytic activity compared to all other NPs.

18.
Sci Rep ; 10(1): 11728, 2020 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678111

RESUMO

A facile and chemical specific method to synthesize highly reduced graphene oxide (HRG) and Pd (HRG@Pd) nanocomposite is presented. The HRG surfaces are tailored with amine groups using 1-aminopyrene (1-AP) as functionalizing molecules. The aromatic rings of 1-AP sit on the basal planes of HRG through π-π interactions, leaving amino groups outwards (similar like self-assembled monolayer on 2D substrates). The amino groups provide the chemically specific binding sites to the Pd nucleation which subsequently grow into nanoparticles. HRG@Pd nanocomposite demonstrated both uniform distribution of Pd nanoparticles on HRG surface as well as excellent physical stability and dispersibility. The surface functionalization was confirmed using, ultraviolet-visible (UV-Vis), Fourier transform infra-red and Raman spectroscopy. The size and distribution of Pd nanoparticles on the HRG and crystallinity were confirmed using high-resolution transmission electron microscopy and powder X-ray diffraction and X-ray photoelectron spectroscopy. The catalytic efficiency of highly reduced graphene oxide-pyrene-palladium nanocomposite (HRG-Py-Pd) is tested towards the Suzuki coupling reactions of various aryl halides. The kinetics of the catalytic reaction (Suzuki coupling) using HRG-Py-Pd nanocomposite was monitored using gas chromatography (GC).

19.
Molecules ; 25(8)2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32295143

RESUMO

A facile, one-pot, and proficient method was developed for the production of various 2-arylaminobenzimidazoles. This methodology is based for the first time on a copper catalyst promoted domino C-N cross-coupling reaction for the generation of 2-arylaminobenzimidazoles. Mechanistic investigations revealed that the synthetic pathway involves a copper-based desulphurization/nucleophilic substitution and a subsequent domino intra and intermolecular C-N cross-coupling reactions. Some of the issues typically encountered during the synthesis of 2-arylaminobezimidazoles, including the use of expensive catalytic systems and the low reactivity of bromo precursors, were addressed using this newly developed copper-catalyzed method. The reaction procedure is simple, generally with excellent substrate tolerance, and provides good to high yields of the desired products.


Assuntos
Benzimidazóis/síntese química , Técnicas de Química Sintética , Cobre/química , Benzimidazóis/química , Benzimidazóis/farmacologia , Catálise , Estrutura Molecular
20.
ACS Omega ; 5(4): 1987-1996, 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32039336

RESUMO

The effective interactions of nanomaterials with biological constituents play a significant role in enhancing their biomedicinal properties. These interactions can be efficiently enhanced by altering the surface properties of nanomaterials. In this study, we demonstrate the method of altering the surface properties of ZrO2 nanoparticles (NPs) to enhance their antimicrobial properties. To do this, the surfaces of the ZrO2 NPs prepared using a solvothermal method is functionalized with glutamic acid, which is an α-amino acid containing both COO- and NH4 + ions. The binding of glutamic acid (GA) on the surface of ZrO2 was confirmed by UV-visible and Fourier transform infrared spectroscopies, whereas the phase and morphology of resulting GA-functionalized ZrO2 (GA-ZrO2) was identified by X-ray diffraction and transmission electron microscopy. GA stabilization has altered the surface charges of the ZrO2, which enhanced the dispersion qualities of NPs in aqueous media. The as-prepared GA-ZrO2 NPs were evaluated for their antibacterial properties toward four strains of oral bacteria, namely, Rothia mucilaginosa, Rothia dentocariosa, Streptococcus mitis, and Streptococcus mutans. GA-ZrO2 exhibited increased antimicrobial activities compared with pristine ZrO2. This improved activity can be attributed to the alteration of surface charges of ZrO2 with GA. Consequently, the dispersion properties of GA-ZrO2 in the aqueous solution have increased considerably, which may have enhanced the interactions between the nanomaterial and bacteria.

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