RESUMO
Abstract In the present study, the metabolite profiling of methanolic extract from aerial parts of Satureja khuzistanica Jamzad, as an endemic medicinal plant from Iran, was evaluated using HPLC-PDA-ESI. Then, the main compound from the extract was isolated and purified by using extensive chromatographic techniques. In addition, the structure of the isolated compounds was elucidated using 1D, 2D NMR, and MS spectrometry, upon which 22 compounds were identified. The antibacterial activity of diosmetin 7-rutinoside (6) and linarin (13) in combination with carvacrol as a major compound of the essential oil was tested against Pseudomonas aeruginosa and Staphylococcus aureus through disc diffusion and minimum inhibitory concentration methods. The results indicated that the linarin, when mixed with carvacrol as the main compounds in the essential oil of the plant, has a satisfactory activity against both Pseudomonas aeruginosa and Staphylococcus aureus with MIC values of 0.16 and 0.18 µg/mL, respectively. Further, the fractional inhibitory concentration (FIC) index indicated that this compound had synergism with carvacrol.
Assuntos
Plantas Medicinais/anatomia & histologia , Óleos Voláteis/análise , Lamiaceae/química , Satureja/classificação , Pseudomonas aeruginosa/isolamento & purificação , Análise Espectral/instrumentação , Testes de Sensibilidade Microbiana/instrumentação , Cromatografia Líquida de Alta Pressão/métodosRESUMO
Abstract The study is aimed to assess the compatibility of bilberry leaf powder extract (BLPE) with six excipients selected for sustained-release (SR) tablet formulation. The BLPE was obtained with the addition of L-arginine and Myo-inositol as the carriers. Thermogravimetric (TG-DTG) analysis and Fourier-transform infrared spectroscopy (FTIR), supported by Pearson correlation analysis, were applied to detect possible interactions in the binary mixtures (1:1) of the BLPE with each excipient. The TG-DTG showed some deviations in the thermal behavior of the BLPE / excipient mixtures. However, only the thermal behavior of magnesium stearate in the mixture significantly differed from individual samples, which suggested chemical interaction for this excipient. The FTIR analysis confirmed that the BLPE is compatible with Eudragit L100, Methocel K4M, Methocel K100LV, Avicel PH-101, and Plasdone S-630. Whereas it undergoes solid-state chemical interaction in the binary mixture with magnesium stearate. According to the FTIR-spectra, it is suggested that this interaction results in the formation of stearic acid and alkalization of the medium. These findings evidence for the possibility of using TG-DTG analysis as an independent thermal technique for compatibility studies and also confirm the earlier reported interaction of basic lubricants, e.g., stearic salts, with active ingredients containing amino groups.
Assuntos
Comportamento , Extratos Vegetais/análise , Folhas de Planta/classificação , Vaccinium myrtillus/efeitos adversos , Vaccinium myrtillus/metabolismo , Preparações de Ação Retardada/análise , Análise Espectral/instrumentação , Termogravimetria/instrumentação , Espectroscopia de Infravermelho com Transformada de Fourier/métodosRESUMO
At the morphological and anatomical levels, the ionome, or the elemental composition of an organism, is an understudied area of plant biology. In particular, the ionomic responses of plant-pathogen interactions are scarcely described, and there are no studies on immune reactions. In this study we explored two X-ray fluorescence (XRF)-based ionome visualisation methods (benchtop- and synchrotron-based micro-XRF [µXRF]), as well as the quantitative inductively coupled plasma optical emission spectroscopy (ICP-OES) method, to investigate the changes that occur in the ionome of compatible and incompatible plant-pathogen interactions. We utilised the agronomically important and comprehensively studied interaction between potato (Solanum tuberosum) and the late blight oomycete pathogen Phytophthora infestans as an example. We used one late blight-susceptible potato cultivar and two resistant transgenic plant lines (only differing from the susceptible cultivar in one or three resistance genes) both in control and P. infestans-inoculated conditions. In the lesions from the compatible interaction, we observed rearrangements of several elements, including a decrease of the mobile macronutrient potassium (K) and an increase in iron (Fe) and manganese (Mn), compared with the tissue outside the lesion. Interestingly, we observed distinctly different distribution patterns of accumulation at the site of inoculation in the resistant lines for calcium (Ca), magnesium (Mg), Mn and silicon (Si) compared to the susceptible cultivar. The results reveal different ionomes in diseased plants compared to resistant plants. Our results demonstrate a technical advance and pave the way for deeper studies of the plant-pathogen ionome in the future.
Assuntos
Interações Hospedeiro-Patógeno/fisiologia , Íons/análise , Phytophthora infestans/patogenicidade , Solanum tuberosum/microbiologia , Análise Espectral/métodos , Suscetibilidade a Doenças , Íons/metabolismo , Metais/metabolismo , Fósforo/metabolismo , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas , Espectrometria por Raios X/instrumentação , Espectrometria por Raios X/métodos , Análise Espectral/instrumentação , SíncrotronsRESUMO
BACKGROUND: In a world constantly challenged by climate change, corn and sorghum are two important grains because of their high productivity and adaptability, and their multifunctional use for different purposes such as human food, animal feed, and feedstock for many industrial products and biofuels. Corn and sorghum can be utilized interchangeably in certain applications; one grain may be preferred over the other for several reasons. The determination of the composition corn and sorghum flour mixtures may be necessary for economic, regulatory, environmental, functional, or nutritional reasons. RESULTS: Laser-induced breakdown spectroscopy (LIBS) in combination with chemometrics, was used for the classification of flour samples based on the LIBS spectra of flour types and mixtures using partial least squares discriminant analysis (PLS-DA) and the determination of the sorghum ratio in sorghum / corn flour mixture based on their elemental composition using partial least squares (PLS) regression. Laser-induced breakdown spectroscopy with PLS-DA successfully identified the samples as either pure corn, pure sorghum, or corn-sorghum mixtures. Moreover, the addition of various levels of sorghum flour to mixtures of corn-sorghum flour were used for PLS analysis. The coefficient of determination values of calibration and validation PLS models are 0.979 and 0.965, respectively. The limit of detection of the PLS models is 4.36%. CONCLUSION: This study offers a rapid method for the determination of the sorghum level in corn-sorghum flour mixtures and the classification of flour samples with high accuracy, a short analysis time, and no requirement for time-consuming sample preparation procedures. © 2020 Society of Chemical Industry.
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Farinha/análise , Análise de Alimentos/métodos , Preparações de Plantas/química , Sorghum/química , Análise Espectral/métodos , Zea mays/química , Análise Discriminante , Contaminação de Alimentos/análise , Análise Espectral/instrumentaçãoRESUMO
In this study, a SPAD value detection system was developed based on a 25-wavelength spectral sensor to give a real-time indication of the nutrition distribution of potato plants in the field. Two major advantages of the detection system include the automatic segmentation of spectral images and the real-time detection of SPAD value, a recommended indicating parameter of chlorophyll content. The modified difference vegetation index (MDVI) linking the Otsu algorithm (OTSU) and the connected domain-labeling (CDL) method (MDVI-OTSU-CDL) is proposed to accurately extract the potato plant. Additionally, the segmentation accuracy under different modified coefficients of MDVI was analyzed. Then, the reflectance of potato plants was extracted by the segmented mask images. The partial least squares (PLS) regression was employed to establish the SPAD value detection model based on sensitive variables selected using the uninformative variable elimination (UVE) algorithm. Based on the segmented spectral image and the UVE-PLS model, the visualization distribution map of SPAD value was drawn by pseudo-color processing technology. Finally, the testing dataset was employed to measure the stability and practicality of the developed detection system. This study provides a powerful support for the real-time detection of SPAD value and the distribution of crops in the field.
Assuntos
Clorofila/análise , Solanum tuberosum , Análise Espectral/instrumentação , Algoritmos , Análise dos Mínimos Quadrados , Folhas de Planta/químicaRESUMO
Tacinga inamoena (K. Schum.) N.P. Taylor & Stuppy, also known as quipá, is a native cactus of the Caatinga used in traditional medicine to treat urethral infections and inflammation. This study aimed to determine the physicochemical characteristics of vegetal drug obtained from the roots of T. inamoena. Analytical techniques and phytochemical tests were used, such as thermal analysis, qualitative and semiquantitative determination of secondary metabolites and spectroscopy at the infrared region. The powder of the vegetal drug met the parameters established by the Brazilian Pharmacopoeia, except for compressibility, which was low. On the thermogravimetric curve, three events related to the mass loss were verified, which correlate with the vegetal drug quality control and play a part in their standardization. The qualitative screening suggested the presence of alkaloids, flavonoids and terpenes. The infrared spectrum reinforced the presence of hydroxyl, carbonyl, and ether groups. In the semiquantitative screening, a concentration for total polyphenols of 65 mg equivalent to gallic acid g-1 to the crude ethanol extract (CEE) was obtained. On the correlation of flavonoid content to seasonality, a concentration was obtained of 3.3 mg equivalent to quercetin g-1 to the CEE obtained during the drought period and of 10.6 mg equivalent to quercetin g-1 to the CCE obtained during the rainy season. In T. inamoena, the presence of important classes of secondary metabolites, which are associated with the pharmacognostic characterization, aids the authentication and quality control of vegetal drugs of importance in traditional Brazilian medicine.
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Preparações Farmacêuticas/administração & dosagem , Raízes de Plantas/efeitos adversos , Cactaceae/classificação , Controle de Qualidade , Análise Espectral/instrumentação , Métodos de Análise Laboratorial e de Campo/métodos , Compostos Fitoquímicos , Infecções/classificação , Fitoterapia/instrumentaçãoRESUMO
OBJECTIVE: Careful screening of bilirubin level in newborns is mandatory as per American Academy of Pediatrics (2004), to reduce incidents of kernicterus and acute bilirubin encephalopathy. Although, invasive capillary collection of blood and subsequent biochemical test is considered a gold standard for jaundice detection in neonates, transcutaneous bilirubin measurement using various non-invasive instruments is also used sporadically across the globe. The major aim of this study was to develop a non-invasive spectrometry-based technique for measurement of neonatal bilirubin level as an alternative of total serum bilirubin (TSB) test without limitations of other available bilirubinometers. METHODS: The instrument comprises of a light source and a spectroscopic detector. A light beam from source incident on the neonatal nail plate through optical fibers. The retro reflected light is acquired using the detector. An indigenously developed software is used to acquire and analyze the optical signal and to calculate the bilirubin value. The instrument was calibrated and validated in reference to TSB on 1033 subjects. MAJOR RESULTS: The result (r = 0.95 and P < 0.001) indicates a strong correlation between the bilirubin value obtained from our method and TSB. Time variant analysis of the subjects undergoing phototherapy provided a good correlation (r = 0.98). The repeatability test result shows the mean coefficient of variation is less than 5.0%. CONCLUSIONS: The indigenously developed non-invasive technique successfully detects the bilirubin level in newborns under various physiological conditions with high accuracy and precision.
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Bilirrubina/sangue , Hiperbilirrubinemia Neonatal/diagnóstico , Processamento de Sinais Assistido por Computador/instrumentação , Análise Espectral/métodos , Desenho de Equipamento , Humanos , Recém-Nascido , Unhas/irrigação sanguínea , Análise Espectral/instrumentaçãoRESUMO
OBJECTIVES: A method was developed to analyze St John's wort (Hypericum perforatum L.) herb and preparations using inductively coupled plasma-optical emission spectroscopy (ICP-OES) to determine the quantity of 11 elements (Al, B, Ba, Ca, Cu, Fe, Mg, Mn, Ni, Sr and Zn). METHODS: This study includes the evaluation of digestion acids and calibration methods, as well as instrumental parameters such as choice of nebulizer and emission wavelength. KEY FINDINGS: Two nebulizers (Conikal and SeaSpray) performed similarly for most elements, and two optimum wavelengths were determined for each element. Five acids were evaluated for the digestion of the Polish Certified Reference Material Tea Leaves (INCT-TL-1), while three were taken forward to use for the different St John's wort formulations (i.e. herb, capsule and tablet). A simple protocol using 5 ml HNO3 was sufficient in most cases; however, variability was observed for elements often bound in silicates (e.g. Al, Fe and Zn). An external weighted calibration was also found to be preferential over unweighted, and the use of standard addition affected some concentration values up to 20%. CONCLUSIONS: Therefore, this paper presents the development and optimized method parameters to be used with ICP-OES that will allow the analysis of 11 key elements present in St John's wort herb and preparations.
Assuntos
Hypericum/química , Preparações de Plantas/análise , Análise Espectral/métodos , Calibragem , Cápsulas , Desenho de Equipamento , Micro-Ondas , Nebulizadores e Vaporizadores , Preparações de Plantas/química , Análise Espectral/instrumentação , ComprimidosRESUMO
In this work, we analysed human fingernails of people who suffer from vitamin D deficiency using the laser-induced breakdown spectroscopy(LIBS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES)techniques. The measurements have been conducted on 71 nail samples collected randomly from volunteers of different genders and ages ranged between 20 and 50 years. The main aim of this study is to find the correlation between vitamin D deficiency and the intensity of some dominated lines in the LIBS spectra. A LIBS spectrum consists of dominant lines of fifteen elements including calcium, magnesium, sodium, potassium, titanium, iron, chloride, sulphur, copper, chromium, zinc, nitrogen, phosphor, and oxygen. By recording the spectrum in specific ranges and focusing on calcium, magnesium, sodium, and potassium, we found a correlation between the intensity of the potassium (K) lines at (766.5 and 769.9â¯nm)and vitamin D level in both age groups (20 and 25 years old), with weak correlation for the calcium (Ca), magnesium (Mg), and sodium (Na) lines. To verify the validity of the LIBS results, we analysed the nail samples with ICP, a standard analytical technique. The elements detected with our LIBS technique are in a good agreement with those identified by ICP-AES. From the health and physiological perspectives, the LIBS system, which is used for spectral analysis in this work, is appropriate for diagnostic purposes such as to find the correlation between vitamin D deficiency and potassium content, especially for hypertensive patients who simultaneously take potassium-based medication and vitamin D supplement.
Assuntos
Alimentos , Lasers , Unhas/química , Deficiência de Vitamina D/diagnóstico , Vitamina D/análise , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Espectral/instrumentação , Termodinâmica , Adulto JovemRESUMO
BACKGROUND: Nitrogen (N) fertilizer plays an important role in tea plantation management, with significant impacts on the photosynthetic capacity, productivity and nutrition status of tea plants. The present study aimed to establish a method for the discrimination of N fertilizer levels using hyperspectral imaging technique. RESULTS: Spectral data were extracted from the region of interest, followed by the first derivative to reduce background noise. Five optimal wavelengths were selected by principal component analysis. Texture features were extracted from the images at optimal wavelengths by gray-level gradient co-occurrence matrix. Support vector machine (SVM) and extreme learning machine were used to build classification models based on spectral data, optimal wavelengths, texture features and data fusion, respectively. The SVM model using fused data gave the best performance with highest correct classification rate of 100% for prediction set. CONCLUSION: The overall results indicated that visible and near-infrared hyperspectral imaging combined with SVM were effective in discriminating N fertilizer levels of tea plants. © 2018 Society of Chemical Industry.
Assuntos
Camellia sinensis/química , Fertilizantes/análise , Nitrogênio/análise , Análise Espectral/métodos , Camellia sinensis/metabolismo , Nitrogênio/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Análise de Componente Principal , Controle de Qualidade , Análise Espectral/instrumentação , Máquina de Vetores de SuporteRESUMO
The search for biomarkers of present or past life is one of the major challenges for in situ planetary exploration. Multiple constraints limit the performance and sensitivity of remote in situ instrumentation. In addition, the structure, chemical, and mineralogical composition of the sample may complicate the analysis and interpretation of the results. The aim of this work is to highlight the main constraints, performance, and complementarity of several techniques that have already been implemented or are planned to be implemented on Mars for detection of organic and molecular biomarkers on a best-case sample scenario. We analyzed a 1000-year-old desiccated and mummified microbial mat from Antarctica by Raman and IR (infrared) spectroscopies (near- and mid-IR), thermogravimetry (TG), differential thermal analysis, mass spectrometry (MS), and immunological detection with a life detector chip. In spite of the high organic content (ca. 20% wt/wt) of the sample, the Raman spectra only showed the characteristic spectral peaks of the remaining beta-carotene biomarker and faint peaks of phyllosilicates over a strong fluorescence background. IR spectra complemented the mineralogical information from Raman spectra and showed the main molecular vibrations of the humic acid functional groups. The TG-MS system showed the release of several volatile compounds attributed to biopolymers. An antibody microarray for detecting cyanobacteria (CYANOCHIP) detected biomarkers from Chroococcales, Nostocales, and Oscillatoriales orders. The results highlight limitations of each technique and suggest the necessity of complementary approaches in the search for biomarkers because some analytical techniques might be impaired by sample composition, presentation, or processing. Key Words: Planetary exploration-Life detection-Microbial mat-Life detector chip-Thermogravimetry-Raman spectroscopy-NIR-DRIFTS. Astrobiology 17, 984-996.
Assuntos
Exobiologia/métodos , Meio Ambiente Extraterreno , Vida , Marte , Métodos Analíticos de Preparação de Amostras/instrumentação , Métodos Analíticos de Preparação de Amostras/métodos , Regiões Antárticas , Biomarcadores/análise , Cianobactérias/química , Cianobactérias/isolamento & purificação , Análise Espectral/instrumentação , Análise Espectral/métodosRESUMO
BACKGROUND AND OBJECTIVE: Real-time monitoring of tissue status during thermal ablation of tumors is critical to ensure complete destruction of tumor mass, while avoiding tissue charring and excessive damage to normal tissues. Currently, magnetic resonance thermometry (MRT), along with magnetic resonance imaging (MRI), is the most commonly used technique for monitoring and assessing thermal ablation process in soft tissues. MRT/MRI is very expensive, bulky, and often subject to motion artifacts. On the other hand, light propagation within tissue is sensitive to changes in tissue microstructure and physiology which could be used to directly quantify the extent of tissue damage. Furthermore, optical monitoring can be a portable, and cost-effective alternative for monitoring a thermal ablation process. The main objective of this study, is to establish a correlation between changes in tissue optical properties and the status of tissue coagulation/damage during heating of ex vivo tissues. MATERIALS AND METHODS: A portable diffuse reflectance spectroscopy system and a side-firing fiber-optic probe were developed to study the absorption (µa (λ)), and reduced scattering coefficients (µ's (λ)) of native and coagulated ex vivo porcine, and chicken breast tissues. In the first experiment, both porcine and chicken breast tissues were heated at discrete temperature points between 24 and 140°C for 2 minutes. Diffuse reflectance spectra (430-630 nm) of native and coagulated tissues were recorded prior to, and post heating. In a second experiment, porcine tissue samples were heated at 70°C and diffuse reflectance spectra were recorded continuously during heating. The µa (λ) and µ's (λ) of the tissues were extracted from the measured diffuse reflectance spectra using an inverse Monte-Carlo model of diffuse reflectance. Tissue heating was stopped when the wavelength-averaged scattering plateaued. RESULTS: The wavelength-averaged optical properties, <µ's (λ)> and <µa (λ)>, for native porcine tissues (n = 66) at room temperature, were 5.4 ± 0.3 cm(-1) and 0.780 ± 0.008 cm(-1) (SD), respectively. The <µ's (λ)> and <µa (λ)> for native chicken breast tissues (n = 66) at room temperature, were 2.69 ± 0.08 cm(-1) and 0.29 ± 0.01 cm(-1) (SD), respectively. In the first experiment, the <µ's (λ)> of coagulated porcine and chicken breast tissue rose to 56.4 ± 3.6 cm(-1) at 68.7 ± 1.7°C (SD), and 52.8 ± 1 cm(-1) at 57.1 ± 1.5°C (SD), respectively. Correspondingly, the <µa (λ)> of coagulated porcine (140.6°C), and chicken breast tissues (130°C) were 0.75 ± 0.05 cm(-1) and 0.263 ± 0.004 cm(-1) (SD). For both tissues, charring was observed at temperatures above 80°C. During continuous monitoring of porcine tissue (with connective tissues) heating, the <µ's (λ)> started to rise rapidly from 13.7 ± 1.5 minutes and plateaued at 19 ± 2.5 (SD) minutes. The <µ's (λ)> plateaued at 11.7 ± 3 (SD) minutes for porcine tissue devoid of connective tissue between probe and tissue surface. No charring was observed during continuous monitoring of thermal ablation process. CONCLUSION: The changes in optical absorption and scattering properties can be continuously quantified, which could be used as a diagnostic biomarker for assessing tissue coagulation/damage during thermal ablation. Lasers Surg. Med. 48:686-694, 2016. © 2016 Wiley Periodicals, Inc.
Assuntos
Hipertermia Induzida , Músculo Esquelético/química , Fenômenos Ópticos , Análise Espectral/métodos , Animais , Galinhas , Sistemas Computacionais , Tecnologia de Fibra Óptica , Técnicas In Vitro , Método de Monte Carlo , Distribuição Aleatória , Espalhamento de Radiação , Análise Espectral/instrumentação , SuínosRESUMO
For the first time, the capability of corona discharge ionization ion mobility spectrometry (CD-IMS) in the determination of metal complex was evaluated. The extreme simplicity of dispersive liquid-liquid microextraction (DLLME) coupled to the high sensitivity of CD-IMS measurement could make this combination really useful for simple, rapid, and sensitive determination of metals in different samples. In this regard, mercury, as a model metal, was complexed with diethyldithiocarbamate (DEDTC), and then extracted into the carbon tetrachloride using DLLME. Some parameters affecting the extraction efficiency, including the type and volume of the extraction solvent, the type and volume of the disperser solvent, the concentration of the chelating agent, salt addition and, pH were exhaustively investigated. Under the optimized condition, the enrichment factor was obtained to be 142. The linear range of 0.035-10.0 µg mL(-1) with r(2) = 0.997 and the detection limit of 0.010 µg mL(-1) were obtained. The relative standard deviation values were calculated to be lower than 4% and 8% for intra-day and inter-day, respectively. Finally, the developed method was successfully applied for the extraction and determination of mercury in various real samples. The satisfactory results revealed the capability of the proposed method in trace analysis without tedious derivatization or hydride generation.
Assuntos
Metais/análise , Metais/química , Análise Espectral/métodos , Animais , Antimônio/análise , Arsênio/análise , Bismuto/análise , Peixes , Concentração de Íons de Hidrogênio , Chumbo/análise , Microextração em Fase Líquida , Mercúrio/análise , Sais/química , Selênio/análise , Análise Espectral/instrumentação , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/químicaAssuntos
Monitoramento de Radiação/métodos , Raios Ultravioleta , Terapia Ultravioleta/normas , Calibragem , Governança Clínica , Desenho de Equipamento , Falha de Equipamento , Previsões , Humanos , Segurança do Paciente , Doses de Radiação , Exposição à Radiação/análise , Monitoramento de Radiação/instrumentação , Reprodutibilidade dos Testes , Pele/efeitos da radiação , Análise Espectral/instrumentação , Terapia Ultravioleta/instrumentação , Terapia Ultravioleta/tendênciasRESUMO
Surface high-harmonic generation in the relativistic regime is demonstrated as a source of extreme ultra-violet (XUV) pulses with extended operation time. Relativistic high-harmonic generation is driven by a frequency-doubled high-power Ti:Sapphire laser focused to a peak intensity of 3·10(19) W/cm2 onto spooling tapes. We demonstrate continuous operation over up to one hour runtime at a repetition rate of 1 Hz. Harmonic spectra ranging from 20 eV to 70 eV (62 nm to 18 nm) were consecutively recorded by an XUV spectrometer. An average XUV pulse energy in the µJ range is measured. With the presented setup, relativistic surface high-harmonic generation becomes a powerful source of coherent XUV pulses that might enable applications in, e.g. attosecond laser physics and the seeding of free-electron lasers, when the laser issues causing 80-% pulse energy fluctuations are overcome.
Assuntos
Óxido de Alumínio/química , Lasers , Teste de Materiais/métodos , Análise Espectral/instrumentação , Titânio/química , Desenho de Equipamento , HumanosRESUMO
Label-free measurements of the reaction kinetics of a small sample volume are essential for efficient drug discovery, requiring methods and systems that are rapid, accurate, and cost-effective. Herein, we present an integrated optofluidic system for label-free characterization of reactions in a nanoliter reagent volume. This system contains a droplet-based microfluidic sampling section and an optical fiber-based spectroscopy detection section. By manipulating droplets containing reagents at certain concentrations at different times, quantifiable measurements via absorption spectroscopy can be made in a simple, sensitive, and high-throughput manner. We have demonstrated our system's capability by performing potency (IC50) assays of an inhibitor in a TEM-1 ß-lactamase (enzyme) and nitrocefin (substrate) system. This integrated platform can potentially provide an automated, label-free, and low-cost method for many other assays of reaction kinetics.
Assuntos
Descoberta de Drogas/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Microfluídica/instrumentação , Microfluídica/métodos , Análise Espectral/instrumentação , Análise Espectral/métodos , Inibidores Enzimáticos/metabolismo , Ensaios de Triagem em Larga Escala/instrumentação , Ensaios de Triagem em Larga Escala/métodos , Concentração Inibidora 50 , Cinética , beta-Lactamases/metabolismoRESUMO
The advancement of angular domain imaging in mesoscopic reflectance multispectral imaging is reported. The key component is an angular filter array that performs the angular filtration of the back-scattered photons and generates image contrast due to the variances in tissue optical properties. The proposed modality enables multispectral imaging of subsurface features for samples too thick for transillumination angular domain spectroscopic imaging (ADSI) approaches. The validation was carried out with tissue-mimicking phantoms with multiple absorptive features embedded below the surface. Multispectral images in the range of 666 to 888 nm clearly revealed the location of the features with the background scattering levels up to 20 cm⻹. The shape of the features was recoverable at depths of up to three to four times the transport mean free path. The spatial resolution was <1 mm and the field-of-view was larger than 2.5 cm x 30. cm. Furthermore, the attenuation spectra of measured absorptive features were successfully extracted. Target detectability and imaging quality with different background scattering levels, target depths, and illumination focal depths were discussed, as well as the capability of ADSI in reflectance optical mesoscopic imaging and its potential applications.
Assuntos
Diagnóstico por Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Análise Espectral/métodos , Diagnóstico por Imagem/instrumentação , Emulsões/química , Humanos , Modelos Biológicos , Imagens de Fantasmas , Fosfolipídeos/química , Pele/química , Óleo de Soja/química , Análise Espectral/instrumentaçãoRESUMO
Spectrochemical analyses of organic liquid media such as vegetable oils and sweetened water were performed with the use of LIBS. The aim of this work is to study, on the basis of spectral analyses by LIBS technique of "Swan band" of C2 emitted by different vegetable oils in liquid phase, the characteristics of each organic media. Furthermore this paper proposes, as a classification, a single parameter that could be used to determine the concentration of saturated fatty acids of vegetable oils. A Nd:YAG operating at λ=532 nm and an energies per pulse of 30 mJ was focused onto the surface of the liquid in ambient air. Following ablation of vegetable oils and sweetened water, we find that vibrational bonds of C2 were released from the molecule containing carbon-carbon bonds linear. In the case of vegetable oils, we find a clear relationship between C2 emission from the plasma and the concentration of saturated fatty acids in the oil.
Assuntos
Ácidos Graxos/análise , Óleos de Plantas/química , Análise Espectral/métodos , Óleos de Plantas/classificação , Análise Espectral/instrumentaçãoRESUMO
The traditional tongue inspection method should be urgently improved due to the relative large diagnosis error probability caused by the excessive dependence on the Chinese physician's experience and judgment. But the application of tongue diagnosis based on image processing is limited by some factors including the performance of light source, image acquisition device and the low recognition rate of similar color for different diseases. In order to overcome these drawbacks, the spectroscopy method was employed to analyze the tongue by using the unique fingerprint effect of tongue spectrum. A spectrometer for tongue diagnosis (STD) was developed to achieve this goal in this paper. Meanwhile, to overcome the shortcomings of traditional light-splitting devices, a plane holographic concave grating was used as the diffractive grating, which not only can improve the luminous flux efficiency and miniaturize system, but also improve the spectral imaging quality and resolution. Experimental results demonstrated that the spectral range of STD reached 340-850 nm, and its spectral resolution is better than 2 nm. And the result of simulation experiment validated the feasibility of spectrometer's system.
Assuntos
Holografia , Medicina Tradicional Chinesa/métodos , Análise Espectral/instrumentação , Língua , Cor , Humanos , Processamento de Imagem Assistida por Computador , LuzRESUMO
Ion mobility spectrometry (IMS) served as a rapid, qualitative screening tool for the analysis of adulterated weight-loss products. We have previously shown that sibutramine extracted into methanol from dietary supplements can be detected at low levels (2ng) using a portable IMS spectrometer, and have adapted a similar method for the analysis of additional weight-loss product adulterants. An FDA collaborative study helped to define the limits for fluoxetine with a limit of detection of 2ng. We also evaluated more readily available, less toxic extraction solvents and found isopropanol and water were comparable to methanol. Isopropanol was favored over water for two reasons: (1) water increases the analysis time and (2) aqueous solutions were more susceptible to pH change, which affected the detection of sibutramine. In addition to sibutamine and fluoxetine, we surveyed 11 weight-loss adulterants; bumetanide, fenfluramine, furosemide, orlistat, phenolphthalein, phentermine, phenytoin, rimonabant, sertraline and two sibutramine analogs, desmethylsibutramine and didesmethylsibutramine, using portable and benchtop ion mobility spectrometers. Out of these 13 active pharmaceutical ingredients (APIs), portable and benchtop ion mobility spectrometers were capable of screening products for 10 of these APIs. The developed procedure was applied to two weight-loss dietary supplements using both portable and benchtop instruments. One product contained didesmethylsibutramine while the other contained didesmethylsibutramine and phenolphthalein.