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1.
Prep Biochem Biotechnol ; 46(8): 850-855, 2016 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-26930128

RESUMO

A new strategy for the construction of a polyphenol oxidase carbon paste biosensor for paracetamol detection is reported. The eggplant (Solanum melongena) was processed to collect the polyphenol oxidase as an enzyme that was incorporated in the carbon paste sensor construction. The constructed sensor displayed high sensitivity and good selection for paracetamol detection and recognition. Optimized conditions included pH 6.0 (highest activity), pH 7.0 (highest stability), pulse amplitude of 50 mV, and 15% of vegetable extract per carbon paste. The sensor displayed a linear range from 20 to 200 µM, with a detection limit of 5 µM. Application of the sensor to paracetamol determination in tablet and oral solutions have shown satisfactory results. The efficiency of the method showed very good repeatability ranging between 1.26 and 1.72% relative standard deviation for interday analysis, while recoveries for paracetamol varied between 97.5 and 99.8% for the voltammetric determination. The strategy for a simple, low cost, and efficient eggplant polyphenol oxidase sensor showcased in this work provides an opportunity for the detection of other phenolic compounds in various matrices.


Assuntos
Acetaminofen/análise , Analgésicos não Narcóticos/análise , Técnicas Biossensoriais/métodos , Catecol Oxidase/metabolismo , Solanum melongena/enzimologia , Acetaminofen/metabolismo , Analgésicos não Narcóticos/metabolismo , Catecol Oxidase/isolamento & purificação , Enzimas Imobilizadas/isolamento & purificação , Enzimas Imobilizadas/metabolismo , Limite de Detecção , Solanum melongena/metabolismo , Comprimidos
2.
Phys Life Rev ; 48: 132-161, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38219370

RESUMO

This survey provides a comprehensive insight into the world of non-invasive brain stimulation and focuses on the evolving landscape of deep brain stimulation through microwave research. Non-invasive brain stimulation techniques provide new prospects for comprehending and treating neurological disorders. We investigate the methods shaping the future of deep brain stimulation, emphasizing the role of microwave technology in this transformative journey. Specifically, we explore antenna structures and optimization strategies to enhance the efficiency of high-frequency microwave stimulation. These advancements can potentially revolutionize the field by providing a safer and more precise means of modulating neural activity. Furthermore, we address the challenges that researchers currently face in the realm of microwave brain stimulation. From safety concerns to methodological intricacies, this survey outlines the barriers that must be overcome to fully unlock the potential of this technology. This survey serves as a roadmap for advancing research in microwave brain stimulation, pointing out potential directions and innovations that promise to reshape the field.


Assuntos
Micro-Ondas , Doenças do Sistema Nervoso , Humanos , Técnicas Estereotáxicas , Tecnologia , Encéfalo/fisiologia
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 316: 124289, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38692101

RESUMO

Biphasic calcium phosphate (BCP), consisting of bioceramics such as HAp + ß-TCP and Ca10(PO4)6(OH)2 + Ca3(PO4)2, is a popular choice for optimizing performance due to its superior biological reabsorption and osseointegration. In this study, BCP was produced by calcining the bones of tilapia fish (Oreochromis niloticus) reared in net cages and slaughtered at an age ranging from 15 to 420 days. The bones were cleaned and dried, calcined at 900 °C for 8 h, and then subjected to high-energy grinding for 3 h to produce BCP powders. After the calcination process, the crystalline phase's hydroxyapatite (HAp) and/or beta-tricalcium phosphate (ß-TCP) were present in the composition of the bioceramic. The age-dependent variation in phase composition was confirmed by complementary vibrational spectroscopy techniques, revealing characteristic peaks and bands of the bioceramic. This variation was marked by an increase in HAp phase and a decrease in ß-TCP phase. Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) from 25 to 1400 °C showed the characteristic mass losses of the material, with a greater loss observed for younger fish, indicating the complete removal of organic components at temperatures above 600 °C. Comparison of the results obtained by X-Ray Diffraction (XRD) and Rietveld refinement with Raman spectroscopy showed excellent agreement. These results showed that with temperature and environment control and adequate fish feeding, it is possible to achieve the desired amounts of each phase by choosing the ideal age of the fish. This bioceramic enables precise measurement of HAp and ß-TCP concentrations and Ca/P molar ratio, suitable for medical orthopedics and dentistry.


Assuntos
Osso e Ossos , Cerâmica , Análise Espectral Raman , Animais , Cerâmica/química , Osso e Ossos/química , Tilápia/metabolismo , Difração de Raios X , Hidroxiapatitas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Fosfatos de Cálcio/química , Termogravimetria
4.
Biosensors (Basel) ; 13(7)2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37504088

RESUMO

The utilization of electrochemical detection techniques in paper-based analytical devices (PADs) has revolutionized point-of-care (POC) testing, enabling the precise and discerning measurement of a diverse array of (bio)chemical analytes. The application of electrochemical sensing and paper as a suitable substrate for point-of-care testing platforms has led to the emergence of electrochemical paper-based analytical devices (ePADs). The inherent advantages of these modified paper-based analytical devices have gained significant recognition in the POC field. In response, electrochemical biosensors assembled from paper-based materials have shown great promise for enhancing sensitivity and improving their range of use. In addition, paper-based platforms have numerous advantageous characteristics, including the self-sufficient conveyance of liquids, reduced resistance, minimal fabrication cost, and environmental friendliness. This study seeks to provide a concise summary of the present state and uses of ePADs with insightful commentary on their practicality in the field. Future developments in ePADs biosensors include developing novel paper-based systems, improving system performance with a novel biocatalyst, and combining the biosensor system with other cutting-edge tools such as machine learning and 3D printing.


Assuntos
Técnicas Biossensoriais , Papel , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos
5.
Toxicol Rep ; 6: 1182-1187, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31763182

RESUMO

Byrsonima sericea DC. (Malpighiaceae) leaves are popularly folk medicine in Brazil used to treat gastro-intestinal disorders including diarrhea and gastric diseases. Ethanol extract (BSEE), ethyl acetate extract (BSEAE) and hexane extract (BSHE) of the leaf part of Byrsonima sericea DC were characterized for their total phenolics, proanthocyanidins and flavonoids content. The total antioxidant capacity of extracts was determined. The ethnopharmacological use of B. sericea leaves was evaluated by assaying BSEE for gastroprotective activity in stomach ulcer induced by indomethacin, intestinal motility and toxicity. Abundance of phenols mainly tannins was found in BSEE. Total phenolics, flavonoids and proanthocyanidins content in BSEE were found to be 0.371, 0.172 and 1.3 × 10-4 (mg/g) respectively. BSEE showed concentration dependent significant scavenging of DPPH values 90.0 (%) respectively. Moreover, oral doses of 500 and 1000 mg/kg did not cause mortality, and there was no difference in animals weight, organs relative weight and alanine transaminase (ALT) and aspartate transaminase (AST), as compared to the control group. Doses of 250, 500 and 1000 mg/kg inhibited the gastric lesions induced by indomethacin in 52, 60 and 62 % respectively. The dose of 1000 mg/kg decreased intestinal motility in animals. The presence of phenolic compounds, including tannins could be associated with the anti-diarrheal action and the antioxidant properties could collaborate to the gastroprotective and anti- diarrheal activities, confirming its popular use of the plant.

6.
Food Chem ; 291: 38-48, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31006469

RESUMO

Carnauba wax is widely used in food, due to its physico-chemical characteristics with a predominance of esters and inert and stable components. Even with so many possibilities for the use of carnauba wax in food, there are still a large number of researchers around the world searching for new applications and a demand for new products with new technologies to improve existing ones. Recently, many parts of research which focus on the use of this wax in conservation and food processing have been carried out, some of which highlight the role of this wax in the microencapsulation of flavours, in preparing edible films and super hydrophobic and biodegradable packaging. This paper discusses the use of carnauba wax in food, including the extraction process of the wax, its chemical and physical characteristics, safety aspects, national and international law and permitted uses, along with the presentation of the main scientific research conducted.


Assuntos
Ceras/análise , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/uso terapêutico , Antioxidantes/química , Edema/tratamento farmacológico , Aditivos Alimentares/química , Manipulação de Alimentos , Humanos , Phoeniceae/química , Phoeniceae/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Ceras/farmacologia
7.
Biomed Pharmacother ; 109: 1670-1679, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30551421

RESUMO

The application of medicinal plants are the most important biotechnological alternative in the treatment of numerous diseases, especially in developing countries, such as Brazil. Among them, we specified some specimens of the genus Cnidoscolus used as phytotherapies, with healing properties, analgesic, anti-inflammatory, antibiotic and diuretic, anticancer, among others. Such effects are possibly associated with the presence of terpenoids, alkaloids, coumarins, flavonoids phenolic compounds, among others. Thus, the objective of this work was to evaluate in the literature the studies on the phytochemical, ethnopharmacological and biotechnological applications of this genus, from 1998 to 2017. Among the sixty-one studies reported in this review, ten species are popularly utilized to pharmacological and/or biotechnological applications. Cnidoscolus aconitifolius and Cnidoscolus chayamansa are the most cited species, which were also supported by either animal or cellular investigations indicating some beneficial pharmacological actions like antioxidant, anti-inflammatory and potential cytotoxic activity. The plant parts of this genus under study are important as sources for the isolation and identification of bioactive molecules with biotechnological applications, among the many diseases treated with this phytotherapy. Given these verdicts, ethnopharmacological approaches are significant systematic tools in the determination of plant species that exhibit medicinal and nutritional purposes. The results presented here should further stimulate the development of validation studies to ensure the safe and effective use of these plant species.


Assuntos
Etnobotânica/métodos , Etnofarmacologia/métodos , Euphorbiaceae , Compostos Fitoquímicos/química , Plantas Medicinais , Animais , Bases de Dados Factuais/tendências , Etnobotânica/tendências , Etnofarmacologia/tendências , Euphorbiaceae/genética , Humanos , Compostos Fitoquímicos/genética , Compostos Fitoquímicos/isolamento & purificação , Fitoterapia/métodos , Fitoterapia/tendências , Extratos Vegetais/química , Extratos Vegetais/genética , Extratos Vegetais/isolamento & purificação , Plantas Medicinais/genética , Especificidade da Espécie
9.
Artigo em Inglês | MEDLINE | ID: mdl-29081820

RESUMO

The present objective of the investigation is to evaluate the antihypercholesterolemic activity of the aqueous fruit pulp extract (APE) of Copernicia prunifera (Miller) H. E. Moore (Arecaceae family). Various chemical characterization methods like thin layer chromatography, Fourier transform infrared spectroscopy, 1H and 13C NMR, and molecular weight by gel permeation chromatography have been employed to characterize the extracted pectin. The present study demonstrated that hypercholesterolemic diet (HD) created hypercholesterolemia, caused significant increases in body weight, total cholesterol, and low-density lipoprotein, and caused decreases in high-density lipoprotein in serum compared with SD group. Two doses (APE 150 and 300 mg/Kg b.w./day) were administered to hyperlipidemic mice for 90 days. APE reversed body weight changes, changed serum lipids to normal values, and significantly inhibited the changes of lipid peroxidation and inflammation in the liver tissues. The renal parameters analyzed (urea and creatinine) altered by diet were reverted to normal values. Our results revealed that aqueous fruit pulp extracts of carnauba reduced hypercholesterolemia showing a potential preventive effect against cardiovascular diseases without side effects cause.

10.
Food Chem ; 190: 506-512, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26213003

RESUMO

The redox behavior of commercial roasted coffee products were evaluated by electroanalysis, whereas high performance liquid chromatography (HPLC) was used for determination of cinnamic acid markers, the total phenolic content (TPC) was achieved by Folin-Ciocalteu assay, and the traditional DPPH (1-diphenyl-2-picrylhydrazyl) method for antioxidant power determination. In turn, an optimized electrochemical index was proposed to estimate the antioxidant power of different samples and it was found a great correlation between all methods. The voltammetric profile of all coffee samples was quite similar, presenting the same number of peaks at the same potential values. Minor differences on current levels were in agreement with the total phenolic and major markers content, as well as, to the antioxidant power. Therefore, the electrochemical methods showed to be practical, low cost and very useful to evaluate the antioxidant properties of coffee samples, which is a relevant quality parameter of this widely consumed beverage.


Assuntos
Antioxidantes/química , Ácidos Cafeicos/química , Café/química , Eletroquímica/métodos , Fenóis/análise , Ácidos Cafeicos/análise , Cromatografia Líquida de Alta Pressão , Oxirredução
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