Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 87
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
PDA J Pharm Sci Technol ; 76(6): 461-473, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35169038

RESUMO

Product can experience a combination of cavitation and agitation stresses as a result of dropping post-manufacture. We optimized terephthalic acid (TA) dosimetry, hydroxyphenyl fluorescein fluorimetry, and p-nitrophenol calorimetry as tools to detect and quantify the levels of hydroxyl radicals generated in solution. Using TA dosimetry, we determined the level of hydroxyl radicals generated from a vial drop and found that it is a function of drop height and fill volume and that protein and excipients may serve to mitigate but not completely quench the radicals. Additionally, we optimized sonication and friability as scale-down models to simulate dropping stresses and applied them to assess the impact on the stability of biologics. Our results suggest that chemical degradation dominates when a protein is subjected to cavitation stress alone, and that physical degradation induced by air-liquid and solid-liquid interfaces is the dominant degradation mode when there is a combination of cavitation and agitation stress. Taken together, this work provides a quick and simplistic approach that can be applied during drug product process development to evaluate the impact of drop stresses on the stability of biologic drug product.


Assuntos
Produtos Biológicos , Produtos Biológicos/química , Sonicação , Proteínas/química , Desenvolvimento de Medicamentos , Estabilidade de Medicamentos
2.
Environ Pollut ; 292(Pt B): 118457, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34742818

RESUMO

A high demand exists in bisphenols (BPs) screening studies for quick, reliable and straightforward analytical methods that generate data faster and simultaneously. Herein, we describe a combination of enzymatic probe sonication (EPS) and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for quick extraction and simultaneous quantification of eight important BPs in animal-derived foods. Results obtained demonstrated that the ultrasonic probe power could not only enhance the enzymatic hydrolysis efficiency, but also accelerate the liquid-liquid extraction procedure. Under optimized EPS parameters, one sample could be exhaustively extracted within 120 s, as compared with 12 h needed for the conventional enzymatic extraction which is more suitable for high-throughput analysis. The method was successfully applied to analyze residual BPs in animal-derived foods collected from Beijing, China. Widespread occurrence of BPA, BPS, BPF, BPAF, BPP, and BPB were found, with detection frequencies of 65.2%, 42.4%, 33.7%, 29.4%, 28.3%, and 27.2%, respectively. The highest total concentration levels of BPs (sum of the eight BPs analyzed, ΣBPs) were found in chicken liver (mean 12.2 µg/kg), followed by swine liver (6.37 µg/kg), bovine muscle (3.24 µg/kg), egg (2.03 µg/kg), sheep muscle (2.03 µg/kg), chicken muscle (1.45 µg/kg), swine muscle (1.42 µg/kg), and milk (1.17 µg/kg). The estimated daily intake (EDI) of BPs, based on the mean and 95th percentile concentrations and daily food consumptions, was estimated to be 5.687 ng/kg bw/d and 22.71 ng/kg bw/d, respectively. The human health risk assessment in this work suggests that currently BPs do not pose significant risks to the consumers because the hazard index (HI) was <1.


Assuntos
Sonicação , Espectrometria de Massas em Tandem , Ração Animal , Animais , Compostos Benzidrílicos/análise , Bovinos , Cromatografia Líquida , Leite/química , Ovinos , Suínos
3.
Ultrason Sonochem ; 73: 105505, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33714088

RESUMO

The objective of this study is to assess the effects of installation and operation of a high-power ultrasound machine (HPU) for the treatment of olive paste by using ultrasound technology in order to evaluate the best way installation and the best definition of the operating conditions of the machine. The study was conducted installing in an industrial olive oil mill a continuous processing ultrasound machine, which used a frequency of 20 kHz able to work at 3200 kg h-1 as feed capacity. Checking of performance has been carried out by the assessment of the different operating and process conditions, assessing in particular the impact of the ultrasound treatment before and after the malaxation phase on performance indicators of the continuous olive oil plant (plant extractability, olive paste rheological characteristic) and on selected chemical properties of the olive oil extracted (quality parameters, antioxidant content, and volatile profiles). In the tested conditions, high-power ultrasound treatment did not produce significant effect on the legal parameters (free acidity, peroxide index and spectrophotometric indexes), while a significant increase in the content of phenolic compounds was generally observed; higher enhancements were more evident when the high-power ultrasound treatment was carried out before the malaxation phase.


Assuntos
Indústria Alimentícia , Azeite de Oliva/isolamento & purificação , Sonicação/instrumentação , Desenho de Equipamento , Reologia
4.
Curr Pharm Des ; 27(34): 3638-3655, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33618641

RESUMO

BACKGROUND: Extraction is the foremost step to isolate the natural constituents from a medicinal plant and leads the process of development of herbal formulation from bench to bed. INTRODUCTION: In the field of extraction, the optimization approach helps in achieving better yield and quality where a response of concern is determined or influenced by various variables. This review aimed at congregating the application of different statistical designs (CCD/BBD) to optimize the Ultrasound assisted extraction (UAE) parameters for the recovery of various plant actives belonging to different categories. METHODOLOGY: The literature published during the last decade in the various reputed databases (Web of Science, Pubmed, Scopus) was reviewed and compiled to reveal the role of response surface methodology in optimizing the influential parameters involved in the ultrasound assisted extraction of herbs. CONCLUSION: From the present investigations, it can be concluded that the different variables, such as sonication power, temperature, time, solute to solvent ratio are generally optimized in UAE of herbs. Moreover, it has also been evidenced from the review of published data that the flavonoids/phenolic acids (>50%) leads the race for the extraction of plants using sound waves. It can be said that the statistically designed UAE has a vast prospective in bringing about a green mutiny in the herbal drug industry and the modeling of various parameters shall be able to absolutely build up a complete drug innovation course (bench to bed).


Assuntos
Compostos Fitoquímicos/isolamento & purificação , Extratos Vegetais/química , Plantas Medicinais/química , Ondas Ultrassônicas , Fracionamento Químico/métodos , Flavonoides/isolamento & purificação , Fenóis/isolamento & purificação , Estudos Prospectivos , Sonicação
5.
Ultrason Sonochem ; 70: 105298, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32769045

RESUMO

In this study, ultrasound either as a pretreatment technique or as an integrated technique was employed to enhance fluidized bed drying of Ascophyllum nodosum, and drying kinetics and dried product quality were assessed. In order to compare technology efficiency and dried product qualities, oven drying and fluidized bed drying (FBD) were employed. The novel drying methods included airborne ultrasound-assisted fluidized bed drying (AUA), ultrasound pre-treatment followed by FBD (USP), and hot water blanching pre-treatment followed byFBD (HWB). Six drying kinetics models were used to describe the drying curves, among which the Page model was the best in fitting USP and AUA. Model by Millidi et al. was employed to describe HWB. Airborne ultrasound in AUA did not reduce energy consumption or drying time, but retained total phenolic content (TPC) as well as colour, and exhibited the highest yield among the novel drying methods. USP and HWB showed lower energy consumption and drying time considerably, but the TPC was the lowest among the studied methods. At the same time, USP dried product exhibited the lowest aw, followed by HWB and then AUA. This studyalso demonstrated that FBD could be a very practical drying method on Irish brown seaweed, and ultrasound-assisted drying methods may have potential developments in Irish brown seaweed drying process.


Assuntos
Ascophyllum/química , Dessecação/métodos , Sonicação , Contagem de Colônia Microbiana , Cinética , Microscopia Eletrônica de Varredura , Modelos Teóricos , Água
6.
Ultrason Sonochem ; 67: 105139, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32348950

RESUMO

The sonochemical degradation of trimethoprim (TMP), a widely used antibiotic, in various water matrices was investigated. The effect of several parameters, such as initial TMP concentration (0.5-3 mg/L), actual power density (20-60 W/L), initial solution pH (3-10), inorganic ions, humic acid and water matrix on degradation kinetics was examined. The pseudo-first order degradation rate of TMP was found to increase with increasing power density and decreasing pH, water complexity (ultrapure water > bottled water > secondary wastewater) and initial TMP concentration. TMP degradation is accompanied by the formation of several transformation products (TPs) as evidenced by LC-QToF-MS analysis. Nine such TPs were successfully identified and their time-trend profiles during degradation were followed. An in silico toxicity evaluation was performed showing that several TPs could potentially be more toxic than the parent compound towards Daphnia magna, Pimephales promelas and Pseudokirchneriella subcapitata.


Assuntos
Anti-Infecciosos Urinários/química , Sonicação , Trimetoprima/química , Poluentes Químicos da Água/química , Anti-Infecciosos Urinários/toxicidade , Trimetoprima/toxicidade , Poluentes Químicos da Água/toxicidade
7.
Ultrason Sonochem ; 63: 104966, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31972376

RESUMO

This study was planned to recycle calcium and the phosphorus-rich Nile tilapia fish scale biowaste into nano-hydroxyapatite (FHAP), using ultrasonic-assisted extraction of calcium and phosphorus from fish scales, which was optimized in term of extraction time, acid concentration, extraction temperature, and ultrasonic power. These two elements were determined simultaneously by inductively coupled plasma atomic emission spectrometry and the FHAP phase was formed upon addition of the extracted element solution in alkaline medium using homogenous precipitation assisted with ultrasound energy. The FHAP adsorbent was characterized by x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller. A combination of FHAP and the ultrasonic method was then used to remove Hg2+ from aqueous solution. Four significant variables affecting Hg2+ removal, namely, adsorbent dosage, pH, ultrasonic power, and adsorption time, were studied. The results exhibited that the optimal conditions for maximizing the removal of Hg2+ were 0.02 g adsorbent dosage, pH 8, 0.4 kW ultrasonic power, 20 min adsorption time, and 30 °C adsorption temperature. The sorption mechanism of Hg2+ was revealed by isotherm modeling, indicating that FHAP adsorbent has a potential for Hg2+ removal in aqueous media with the maximum adsorption capacity being 227.27 mg g-1. This adsorption behavior is in agreement with the Langmuir model as reflected by a satisfactory R2 value of 0.9967, when the kinetics data were fitted with pseudo-second-order. Therefore, the FHAP could be an alternative adsorbent for the ultrasonic-assisted removal of Hg2+ at very high efficiency and within a very short period of time.


Assuntos
Durapatita/química , Grafite/química , Mercúrio/isolamento & purificação , Nanopartículas/química , Pontos Quânticos , Sonicação , Tilápia/metabolismo , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Animais , Concentração de Íons de Hidrogênio , Cinética
8.
Ultrason Sonochem ; 63: 104934, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31945562

RESUMO

The electro-oxidation of organic molecules at the anode with simultaneous generation of hydrogen at the cathode in electrosynthesis reactors is considered as a promising and efficient process for the co-production of hydrogen and bio-sourced value-added chemicals. In this study and for the first time, we investigated the electro-oxidation of glucose and methylglucoside in 0.1 mol L-1 NaOH on polycrystalline Pt (real surface area = 14.5 ± 0.5 cm2, roughness ≈ 5) in the potential range [0; +1.20 V vs. rhe] under silent and ultrasonic (bath, 45 kHz, Pacous = 11.20 W) conditions. A series of linear sweep voltammograms, chronoamperograms and high-performance liquid chronoamperograms were generated. It was found that higher current densities were obtained under ultrasonic conditions over the potential range of +0.25 V to +1.10 V vs. rhe, indicating that higher oxidation rates were provided under ultrasonication. It was observed that the desorption of species from the Pt surface in the medium potential region was favoured, allowing free catalytic Pt sites for further adsorption and oxidation of reactants; and in the high potential region, high peak current densities in the presence of ultrasound was due to enhanced mass transport of the electroactive species from the bulk electrolyte to the Pt-polycrystalline electrode surface. HPLC studies confirmed that higher electrochemical activity was obtained in the presence of ultrasound than in the absence. In our conditions, it was also found that low frequency ultrasound did not change the selectivity of the glucose and methylglucoside electro-oxidation reactions but instead, a significant increase in the rate of conversion was observed.


Assuntos
Técnicas Eletroquímicas/métodos , Sonicação , Adsorção , Glucose/química , Metilglucosídeos/química , Oxirredução
9.
Food Chem ; 303: 125396, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31446365

RESUMO

This study describes the determination of lead at trace levels by slotted quartz tube flame atomic absorption spectrophotometry (SQT-FAAS) after preconcentration by the help of stearic acid coated magnetic nanoparticle (SAC-MNPs) based sonication assisted dispersive solid phase extraction (SA-DSPE). SAC-MNPs were used due to their easy separation advantages by the application of external magnetic field. All extraction parameters were optimized by response surface methodology based experimental design. The experimented data was evaluated by the analysis of variance. Under the optimum conditions, about 31 folds enhancement in detection power was obtained over the conventional FAAS. The recovery results obtained for samples spiked at 60 and 120 ng mL-1 were 106.6 and 102.6%, respectively, validating the method as accurate and applicable to the red pepper matrix. The percent relative standard deviations of the results were under 5.0% even at low concentrations that established high precision for replicate extractions and instrumental readings.


Assuntos
Capsicum/química , Chumbo/análise , Chumbo/isolamento & purificação , Microextração em Fase Líquida/métodos , Magnetismo/métodos , Extração em Fase Sólida/métodos , Espectrofotometria Atômica/métodos , Contaminação de Alimentos/análise , Frutas/química , Magnetismo/instrumentação , Nanopartículas de Magnetita/química , Quartzo/química , Sensibilidade e Especificidade , Sonicação , Ácidos Esteáricos/química
10.
Ultrason Sonochem ; 59: 104728, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31421619

RESUMO

Ultra-sonication (US) at varying intensities (200 W, 300 W and 400 W) and hydrodynamic cavitation (HC) at increasing pressures (6 bar, 8 bar and 10 bar) on freshly extracted peanut milk as non-thermal processing of milk for enhanced quality. The effects of US and HC was investigated on physico-chemical properties of peanut milk, microbial inactivation (total plate count and yeasts and molds), microstructure by optical microscopy and particle size, ζ-potential, sedimentation index, rheology and color measurements. The high temperature short time (HTST) treated milk samples have shown 1.53 and 2 log reduction in TPC, yeast and molds respectively with highest protein hydrolysis of 15.7%. Among the non-thermal treatments HC has shown highest log reduction of TPC at around 1.2 for sample treated at 10 bar pressure, whereas the US treatment was most effective for yeast and mold at 400 W with log reduction of 0.9. A non-Newtonian flow behaviour was observed for all peanut milk samples. Viscosity determined by Herschel-Bulkley equation decreased significantly (p > 0.05) after both cavitation treatments. The US was found to be superior to HC and HTST with improved separation index and colour attributes. Therefore, the US and HC appear to be a remarkable non-thermal processing methods for peanut milk and or any dairy or non-dairy beverages.


Assuntos
Arachis/química , Bebidas/microbiologia , Fenômenos Químicos , Hidrodinâmica , Viabilidade Microbiana , Sonicação , Arachis/microbiologia , Cor , Concentração de Íons de Hidrogênio , Hidrólise , Fenômenos Ópticos , Tamanho da Partícula , Proteínas de Plantas/química , Solubilidade , Temperatura
11.
Food Chem ; 297: 124926, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253318

RESUMO

Sand was studied as a solid support in ultrasound-assisted matrix solid-phase dispersion (UA-MSPD) for the extraction of different pesticide classes, including organophosphates, carbamates, triazoles and pyrethroids from fruits and vegetables, with determination by GC-MS and LC-MS/MS. The performance of sand was compared with that of different types of classic solid supports and alternative natural materials from renewable sources. The best results were obtained using 0.5 g sample, 1 g sand as a solid support, 20 mg activated charcoal and 5 mL ethyl acetate as elution solvent. Recoveries ranged from 55 to 140% with an RSD ≤ 20%. LOQs varied from 0.005 to 0.5 mg kg-1 for all analytes. Thiamethoxam, captan, chlorpyrifos, dimethoate and pyrimethanil were found in strawberry samples at concentrations from 0.01 to 0.06 mg kg-1. Acephate and tebuconazole were found in a tomato sample at concentrations of 0.45 and 0.30 mg kg-1, respectively. The method developed was efficient, simple, cheap, robust, and environmentally friendly.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas , Resíduos de Praguicidas/análise , Extração em Fase Sólida/métodos , Verduras/química , Cromatografia Líquida de Alta Pressão , Dimetoato/química , Frutas/química , Frutas/metabolismo , Limite de Detecção , Resíduos de Praguicidas/isolamento & purificação , Piretrinas/química , Sonicação , Espectrometria de Massas em Tandem , Triazóis/química , Verduras/metabolismo
12.
Ultrason Sonochem ; 52: 41-49, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30718177

RESUMO

A device generating low-frequency and low-intensity ultrasound waves was used for mitigating biofilm accumulation and scaling. Two systems were tested: a lab-scale plate heat exchanger operated with continuously recycled water and a continually fed flow-through drinking water pilot used for mimicking water circulation in pipes. Initial deposition of bacterial cells was not prevented by ultrasound wave treatment. However, whatever the tested system, both further calcium carbonate deposition and biofilm growth were markedly inhibited. Biofilms formed in reactors subjected to low-frequency and low-intensity ultrasound waves were weakly attached to the material. Even though the activity of bacteria was affected as shown by their lower cultivability, membrane permeability did not appear compromised. Ultrasound technology sounds very promising in both the mitigation of drinking water biofilm and carbonate accumulation.


Assuntos
Biofilmes/crescimento & desenvolvimento , Carbonatos/análise , Água Potável/química , Água Potável/microbiologia , Sonicação/instrumentação , Carbonatos/química , Temperatura Alta
13.
Prep Biochem Biotechnol ; 49(1): 21-29, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30621500

RESUMO

Psidium guajava leaves are rich in health-promoting flavonoids compounds. For better utilization of the resource, the ultrasound-assisted aqueous extraction was investigated using Box-Behnken design under response surface methodology. A high coefficient of determination (R2 = 97.8%) indicated good agreement between the experimental and predicted values of flavonoids yield. The optimal extraction parameters to obtain the highest total flavonoids yield were ultrasonic power of 407.41 W, extraction time of 35.15 min, and extraction temperature of 72.69 °C. The average extraction rate of flavonoids could reach 5.12% under the optimum conditions. Besides, HPLC analysis and field emission scanning electron microscopy indicated that the ultrasonic treatment did not change the main component of flavonoids during extraction process and the higher flavonoids content was attributed by the disruption of the cell walls of guava particles. Thus, the extraction method could be applied successfully for large-scale extraction of total flavonoids from guava leaves.


Assuntos
Flavonoides/isolamento & purificação , Extratos Vegetais/química , Folhas de Planta/química , Psidium/química , Sonicação/normas , Cromatografia Líquida de Alta Pressão , Custos e Análise de Custo , Flavonoides/análise , Temperatura Alta , Microscopia Eletrônica de Varredura , Sonicação/economia , Propriedades de Superfície , Fatores de Tempo , Água
14.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 5705-5708, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30441631

RESUMO

High Intensity Focused Ultrasound (HIFU) is a very promising technology for a non-invasive treatment of several pathologies, especially in oncology. However, optimizing the stimulation parameters for better tuning the induced lethal effects (thermal and/or mechanical) in the targeted area is not trivial and it has not been achieved yet. The aim of this study is to present the results of a combined analysis of temperature, acoustic cavitation and lesion geometry induced in ex vivo tissues during HIFU procedures by varying power, sonication time and duty cycle. Temperature rise was analyzed using a thin wire thermocouple embedded in the sonicated tissue; stable and inertial cavitation were measured using a passive cavitation detector (PCD), and lesion volume was assessed using both ultrasound imaging and optical visualization. The obtained results may represent an important guideline for clinical treatments, providing useful nformation for better tuning HIFU operational parameters to induce a desired type of ablation (i.e. thermal, mechanical or a combination of both).


Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade , Acústica , Sonicação , Temperatura , Ultrassonografia
15.
Int J Pharm ; 548(1): 375-384, 2018 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-29991454

RESUMO

The study aimed to fabricate innovative drug-phospholipid complexes termed "sonocomplexes" adopting ultrasound irradiation to increase the liposolubility and to enhance the intestinal absorption of rosuvastatin as a model drug for BCS class III active pharmaceutical ingredients (APIs). A 22 full factorial design was fashioned to investigate the influence of phosphatidylcholine content in the phospholipid (∼30 and 60%) and molar ratio of phospholipid to rosuvastatin (1:1 and 2:1) on physicochemical properties of sonocomplexes. In comparison to pure drug, sonocomplexes showed a minimum of about 2 folds and a maximum of about 15 folds increase in lipophilicity (expressed in terms of partition coefficient, P). Results of molecular docking, dynamic simulations, Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) confirmed the strong interactions between rosuvastatin and the phospholipid via hydrogen bonding interaction, van der Waals forces and hydrophobic interaction. The complexation efficiency reached around 99% and transmission electron microscopy (TEM) of the aqueous dispersion of the optimal sonocomplex showed spherical nanosized vesicles. The optimal sonocomplex showed significantly superior Caco-2 cells permeability and markedly better oral bioavailability compared to the pure drug. In summary, sonocomplexes can be considered as effective approach for enhancing the liposolubility and consequently the intestinal permeability of BCS class III drugs.


Assuntos
Sistemas de Liberação de Medicamentos , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Fosfolipídeos/administração & dosagem , Rosuvastatina Cálcica/administração & dosagem , Administração Oral , Animais , Disponibilidade Biológica , Células CACO-2 , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/química , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacocinética , Absorção Intestinal , Masculino , Simulação de Acoplamento Molecular , Permeabilidade , Fosfolipídeos/química , Fosfolipídeos/farmacocinética , Ratos Wistar , Rosuvastatina Cálcica/química , Rosuvastatina Cálcica/farmacocinética , Sonicação
16.
J Photochem Photobiol B ; 180: 56-67, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29413702

RESUMO

Proper waste disposal from household and restaurants is becoming an important and recurring waste-management concern. Herein, a method of upcycling of waste kitchen chimney oil has been adopted to prepare fluorescent multifunctional carbon quantum dots. These nanodots showed superior biocompatibility, excellent optical properties, water solubility and high yield. Preparation of C-dots from highly abundant carbon source of waste refusals is highly effective in commercial aspect as well as in reducing the immense environmental pollution. The C-dots showed quasi-spherical size obtained from high resolution transmission electron microscopy (HRTEM) having an abundance of 1-4 nm in size. The ease of water dispersibility of the nanodots is a mere reflection of their surface polarity which has been supported by Fourier transformed infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). In the field of practical acceptability, the C-dots have been experimented to sense Fe3+ ion in a wide range of concentration (1 nM to 600 µM) with a detection limit of 0.18 nM which can be termed as 'tracer metal chemosensor'. Moreover, the prepared carbon dots were also tested against inter-cellular Fe3+ ion sensing probe. Lastly, we also fabricate the biopolymer­carbon dots composite for fluorescent marker ink and light emitting polymer film.


Assuntos
Monitoramento Ambiental/métodos , Compostos Férricos/análise , Óleos de Plantas/química , Polímeros/química , Pontos Quânticos/química , Carbono/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Monitoramento Ambiental/economia , Corantes Fluorescentes/química , Humanos , Íons/química , Limite de Detecção , Microscopia de Força Atômica , Microscopia de Fluorescência , Tamanho da Partícula , Espectroscopia Fotoeletrônica , Pontos Quânticos/toxicidade , Sonicação , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
17.
Food Chem ; 244: 311-316, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29120787

RESUMO

A comparative study between microwave assisted and sonication methods was carried out to extract arsenic (As) species in shellfish samples using different extractants. Six As species including arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AsB) and arsenocholine (AsC) were simultaneously separated and determined by the HPLC-ICP-MS method. The microwave assisted method exhibited higher efficiency than sonication, especially using diluted HNO3 as extractant. By compromising extraction efficiency, pretreatment time and stability of As species, the microwave assisted method using 1% HNO3 at 100°C for 1.5h was selected to extract As from real samples. The proposed method has been applied to extract and determine As species in shellfish samples. The result of correlation analysis indicated that the proportion of AsB in the shellfish samples was decreased with total As concentration increasing due to the biotransformation threshold from inorganic As to AsB.


Assuntos
Arsenicais/análise , Contaminação de Alimentos/análise , Frutos do Mar/análise , Arseniatos/análise , Arsênio/análise , Arsenitos/análise , Fracionamento Químico/métodos , Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos/métodos , Humanos , Espectrometria de Massas/métodos , Micro-Ondas , Medição de Risco/métodos , Sonicação
18.
J Pharm Biomed Anal ; 149: 33-39, 2018 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-29100028

RESUMO

A Total Organic Carbon (TOC) based analytical method to quantitate trace residues of clean-in-place (CIP) detergents CIP100® and CIP200® on the surfaces of pharmaceutical manufacturing equipment was developed and validated. Five factors affecting the development and validation of the method were identified: diluent composition, diluent volume, extraction method, location for TOC sample preparation, and oxidant flow rate. Key experimental parameters were optimized to minimize contamination and to improve the sensitivity, recovery, and reliability of the method. The optimized concentration of the phosphoric acid in the swabbing solution was 0.05M, and the optimal volume of the sample solution was 30mL. The swab extraction method was 1min sonication. The use of a clean room, as compared to an isolated lab environment, was not required for method validation. The method was demonstrated to be linear with a correlation coefficient (R) of 0.9999. The average recoveries from stainless steel surfaces at multiple spike levels were >90%. The repeatability and intermediate precision results were ≤5% across the 2.2-6.6ppm range (50-150% of the target maximum carry over, MACO, limit). The method was also shown to be sensitive with a detection limit (DL) of 38ppb and a quantitation limit (QL) of 114ppb. The method validation demonstrated that the developed method is suitable for its intended use. The methodology developed in this study is generally applicable to the cleaning verification of any organic detergents used for the cleaning of pharmaceutical manufacturing equipment made of electropolished stainless steel material.


Assuntos
Carbono/análise , Detergentes/química , Contaminação de Medicamentos/prevenção & controle , Contaminação de Equipamentos/prevenção & controle , Tecnologia Farmacêutica/métodos , Limite de Detecção , Oxirredução , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Sonicação , Aço Inoxidável/química , Tecnologia Farmacêutica/normas
19.
Ultrasound Med Biol ; 44(2): 368-376, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29254872

RESUMO

Low-boiling-point perfluorocarbon phase-change contrast agents (PCCAs) provide an alternative to microbubble contrast agents. Although parameter ranges related to in vivo bio-effects of microbubbles are fairly well characterized, few studies have been done to evaluate the potential of bio-effects related to PCCAs. To bridge this gap, we present an assessment of biological effects (e.g., hemorrhage) related to acoustically excited PCCAs in the rodent kidney. The presence or absence of bio-effects was observed after sonication with various perfluorocarbon core PCCAs (decafluorobutane, octafluoropropane or a 1:1 mixture) and as a function of activation pulse mechanical index (MI; minimum activation threshold, which was a moderate MI of 0.81-1.35 vs. a clinical maximum of 1.9). Bio-effects on renal tissue were assessed through hematology and histology including measurement of blood creatinine levels and the quantity of red blood cell (RBC) casts present in hematoxylin and eosin-stained kidney tissue sections after sonication. Short-term (24 h) and long-term (2 and 4 wk) analyses were performed after treatment. Results indicated that bio-effects from PCCA vaporization were not observed at lower mechanical indices. At higher mechanical indices, bio-effects were observed at 24 h, although these were not observable 2 wk after treatment.


Assuntos
Meios de Contraste/química , Fluorocarbonos/química , Rim/efeitos dos fármacos , Sonicação , Animais , Feminino , Modelos Animais , Ratos , Ratos Endogâmicos F344 , Volatilização
20.
J Microbiol Methods ; 145: 28-36, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29246779

RESUMO

Continuous and reliable monitoring of water sources for human consumption is imperative for public health. For protozoa, which cannot be multiplied efficiently in laboratory settings, concentration and recovery steps are key to a successful detection procedure. Recently, the use of megasonic energy was demonstrated to recover Cryptosporidium from commonly used water industry filtration procedures, forming thereby a basis for a simplified and cost effective method of elution of pathogens. In this article, we report the benefits of incorporating megasonic sonication into the current methodologies of Giardia duodenalis elution from an internationally approved filtration and elution system used within the water industry, the Filta-Max®. Megasonic energy assisted elution has many benefits over current methods since a smaller final volume of eluent allows removal of time-consuming centrifugation steps and reduces manual involvement resulting in a potentially more consistent and more cost-effective method. We also show that megasonic sonication of G. duodenalis cysts provides the option of a less damaging elution method compared to the standard Filta-Max® operation, although the elution from filter matrices is not currently fully optimised. A notable decrease in recovery of damaged cysts was observed in megasonic processed samples, potentially increasing the abilities of further genetic identification options upon isolation of the parasite from a filter sample. This work paves the way for the development of a fully automated and more cost-effective elution method of Giardia from water samples.


Assuntos
Água Potável/parasitologia , Giardia lamblia/isolamento & purificação , Giardíase/prevenção & controle , Sonicação/instrumentação , Doenças Transmitidas pela Água/prevenção & controle , Centrifugação/instrumentação , Água Potável/normas , Monitoramento Ambiental/economia , Monitoramento Ambiental/instrumentação , Filtração/instrumentação , Giardia lamblia/patogenicidade , Humanos , Sonicação/economia , Som , Microbiologia da Água/normas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA