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1.
IET Nanobiotechnol ; 15(4): 391-401, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34694712

RESUMO

Biogenic silica synthesised from rice husk was used as a controlled release system of an eco-friendly biocide consisting of a Justicia adhatoda extract. Fourier-transform infrared spectroscopy (FTIR) indicated the presence of ester bonds between the silica support and the conjugated Justicia adhatoda extract. Surface area analysis and microscopy confirmed a high level of Justicia adhatoda extract loading in the silica support. The phytochemical investigation of Justicia adhatoda was done by Gas chromatography-mass spectrometry (GC-MS) spectroscopy. Moreover, compared with the naked biogenic silica nanoparticles, a better thermal stability was determined for the conjugated system of the extracted compounds. Trial of kinetic release of silica: Justicia adhatoda ∼29% of loaded Justicia adhatoda was released within 1 h and then the rate of release became slow. Net release of Justicia adhatoda was observed up to 50% within 7 h. The Justicia adhatoda compounds released from silica also showed the improved mortality rate against stored product pest rice weevil (Sitophilus oryzae).


Assuntos
Desinfetantes , Justicia , Nanopartículas , Extratos Vegetais , Folhas de Planta , Dióxido de Silício
2.
Cardiovasc Drugs Ther ; 31(5-6): 511-524, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28965151

RESUMO

PURPOSE: Sodium thiosulfate (STS) has of late been proven efficacious in models of urolithiasis and vascular calcification. However, its cardiovascular effects on ischemia reperfusion injury (IR) have not been revealed. Being an antioxidant and calcium chelator, it is assumed to play a vital role in IR as ROS production and calcium overload are major perpetrators of IR injury. METHODS: The cardioprotective effect of STS was evaluated in vitro using H9C2 cardiomyocytes and in vivo using both isolated rat heart and intact left anterior descending artery (LAD) occlusion models of ischemia reperfusion injury. Finally, in silico tools were utilized to establish its possible mode of action. Myocardial injury markers and expression of apoptotic proteins were studied along with myocardial histopathology. RESULTS: STS of 1 mM recovered H9C2 cells from glucose oxidase/catalase-induced apoptosis. The isolated rat heart treated with STS prior to IR injury improved its hemodynamics and reduced the infarct size to 9%. This was supported by the absence of derangement of cardiac fibers from H&E stained section of LAD-occluded rats. Plasma troponin levels decreased by 15% compared to IR and the myocardium showed diminished apoptotic proteins. An in silico docking analysis revealed higher binding affinity of STS for caspase-3 with a binding energy of - 60.523 kcal/mol for the complex. CONCLUSION: The effectiveness of STS as a cardioprotective agent is attributed to the reduction of apoptosis by binding to the active site of caspase-3 in silico, which was substantiated by the reduced expression of caspase-3 and poly ADP ribose polymerase levels.


Assuntos
Apoptose/efeitos dos fármacos , Cardiotônicos/uso terapêutico , Precondicionamento Isquêmico Miocárdico , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Estresse Oxidativo/efeitos dos fármacos , Tiossulfatos/uso terapêutico , Animais , Cardiotônicos/administração & dosagem , Caspase 3/metabolismo , Linhagem Celular , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Simulação de Acoplamento Molecular , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Ligação Proteica , Ratos , Tiossulfatos/administração & dosagem
3.
J Acoust Soc Am ; 142(2): EL170, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28863564

RESUMO

In this paper a simple iterative algorithm that is guaranteed to produce a stable all-pole filter when minimizing the 1-norm of the linear prediction error signal is proposed. The approach works for both the autocorrelation and covariance frameworks, involves only a one-dimensional search at each step, and obviates the need for linear programming based methods. Based on simulation studies, it was observed that the performance of the algorithm is nearly optimal, i.e., very close to the estimates obtained using interior point methods. Moreover, this method also has the ability to constrain the bandwidth of any peak. The proposed method has been applied for vocal tract estimation and, using spectral distortion as the metric, results are presented using synthetic as well as natural speech.


Assuntos
Acústica , Modelos Teóricos , Processamento de Sinais Assistido por Computador , Acústica da Fala , Medida da Produção da Fala/métodos , Algoritmos , Simulação por Computador , Humanos , Modelos Lineares , Qualidade da Voz
4.
Artigo em Inglês | MEDLINE | ID: mdl-25062057

RESUMO

The potential effect of Catharanthus roseus leaf extract for the formation of palladium nanoparticles and its application on dye degradation was discussed. The efficiency of C.roseus leaves are used as a bio-material for the first time as reducing agent. Synthesized palladium nanoparticles were supported by UV-vis spectrometry, XRD, FT-IR and TEM analysis. The secondary metabolites which are responsible for the formation of nanoparticles were identified by GC-MS. The results showed that effect of time was directly related to synthesized nanoparticles and functional groups has a critical role in reducing the metal ions and stabilizing the palladium nanoparticles in an eco-friendly process.


Assuntos
Catharanthus/química , Luz , Nanopartículas Metálicas/química , Paládio/química , Fotólise/efeitos da radiação , Extratos Vegetais/química , Folhas de Planta/química , Catálise/efeitos da radiação , Cromatografia Gasosa-Espectrometria de Massas , Nanopartículas Metálicas/ultraestrutura , Tamanho da Partícula , Metabolismo Secundário , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo , Difração de Raios X
5.
Ecotoxicology ; 22(4): 707-17, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23512438

RESUMO

In this study, an attempt was made to identify an effective phosphate solubilizing bacteria from pesticide polluted field soil. Based on the formation of solubilization halo on Pikovskaya's agar, six isolates were selected and screened for pesticide tolerance and phosphate (P) solubilization ability through liquid assay. The results showed that only one strain (SGRAJ09) obtained from Achillea clavennae was found to tolerate maximum level of the pesticides tested and it was phylogenetically identified as Pseudomonas sp. It possessed a wide range of pesticide tolerance, ranging from 117 µg mL(-1) for alphamethrin to 2,600 µg mL(-1) for endosulfan. The available P concentrations increased with the maximum and double the maximum dose of monocrotophos and imidacloprid, respectively. On subjected to FT-IR and HPLC analysis, the presence of organic acids functional group in the culture broth and the production of gluconic acid as dominant acid aiding the P solubilization were identified. On comparison with control broth, monocrotophos and imidacloprid added culture broth showed quantitatively high organic acids production. In addition to gluconic acid production, citric and acetic acids were also observed in the pesticide amended broth. Furthermore, the Pseudomonas sp. strain SGRAJ09 possessed all the plant growth promoting traits tested. In presence of monocrotophos and imidacloprid, its plant growth promoting activities were lower than that of the pesticides unamended treatment.


Assuntos
Achillea/microbiologia , Praguicidas/metabolismo , Fósforo/metabolismo , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo , Microbiologia do Solo , Amônia/metabolismo , Carbono-Carbono Liases/metabolismo , Cromatografia Líquida de Alta Pressão , Cianeto de Hidrogênio/metabolismo , Imidazóis/metabolismo , Ácidos Indolacéticos/metabolismo , Monocrotofós/metabolismo , Neonicotinoides , Nitrocompostos/metabolismo , Fosfatos/metabolismo , Filogenia , Pseudomonas/classificação , Pseudomonas/crescimento & desenvolvimento , Rizosfera , Sideróforos/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier
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