Multi-criteria optimization for ultrasonic-assisted extraction of antioxidants from Pericarpium Citri Reticulatae using response surface methodology, an activity-based approach.

PubMed

Zeng, Shanshan; Wang, Lu; Zhang, Lei; Qu, Haibin; Gong, Xingchu

2013-06-01

An activity-based approach to optimize the ultrasonic-assisted extraction of antioxidants from Pericarpium Citri Reticulatae (Chenpi in Chinese) was developed. Response surface optimization based on a quantitative composition-activity relationship model showed the relationships among product chemical composition, antioxidant activity of extract, and parameters of extraction process. Three parameters of ultrasonic-assisted extraction, including the ethanol/water ratio, Chenpi amount, and alkaline amount, were investigated to give optimum extraction conditions for antioxidants of Chenpi: ethanol/water 70:30 v/v, Chenpi amount of 10 g, and alkaline amount of 28 mg. The experimental antioxidant yield under the optimum conditions was found to be 196.5 mg/g Chenpi, and the antioxidant activity was 2023.8 μmol Trolox equivalents/g of the Chenpi powder. The results agreed well with the second-order polynomial regression model. This presented approach promised great application potentials in both food and pharmaceutical industries. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Supercritical CO2 extraction and component analysis of Aesculus wilsonii seed oil].

PubMed

Chen, Guang-Yu; Shi, Zhao-Hua; Li, Hai-Chi; Ge, Fa-Huan; Zhan, Hua-Shu

2013-03-01

To research the optimal extraction process of supercritical CO2 extraction and analyze the component of the oil extracted from Aesculus wilsonii seed. Using the yield of Aesculus wilsonii seed oil as the index, optimized supercritical CO2 extraction parameter by orthogonal experiment methodology and analysed the compounds of Aesculus wilsonii seed oil by GC-MS. The optimal parameters of the supercritical CO2 extraction of the oil extracted from Aesculus wilsoniit seed were determined: the extraction pressure was 28 MPa and the temperature was 38 degrees C, the separation I pressure was 12 MPa and the temperature was 40 degrees C, the separation II pressure was 5 MPa and the temperature was 40 degrees C, the extraction time was 110 min. The average extraction rate of Aesculus wilsonii seed oil was 1.264%. 26 kinds of compounds were identified by GC-MS in Aesculus wilsonii seed oil extracted by supercritical CO2. The main components were fatty acids. Comparing with the petroleum ether extraction, the supercritical CO2 extraction has higher extraction rate, shorter extraction time, more clarity oil. The kinds of fatty acids with high amounts in Aesculus wilsonii seed oil is identical in general, the kinds of fatty acids with low amounts in Aesculus wilsonii seed oil have differences.

[Study on extraction and purification process of total ginsenosides from Radix Ginseng].

PubMed

Xie, Li-Ling; Ren, Li; Lai, Xian-Sheng; Cao, Jun-Hui; Mo, Quan-Yi; Chen, Wei-Wen

2009-10-01

To optimize the technological parameters of the extraction and purification process of total ginsenosides from Radix Ginseng. With the contents of ginsenoside Rg1, ginsenoside Re and ginsenoside Rb1, the orthogonal design was adopted to optimize the extraction process. The purification process was studied by optimizing the elutive ratio of total ginsenosides as the marker. HPLC and spectrophotometer were employed for the study. The optimum conditions were as follows:Using 8 times volume of 75% ethanol extracting for 120 minutes and 2 times, the extraction temperature was 85 degrees C. AB-8 macroporous resin was selected, and the eluant was 4 BV 70% ethanol. The optimal conditions of extracting and purifying the total ginsenosides from Radix Ginseng is feasible.

Optimization of extraction of linarin from Flos chrysanthemi indici by response surface methodology and artificial neural network.

PubMed

Pan, Hongye; Zhang, Qing; Cui, Keke; Chen, Guoquan; Liu, Xuesong; Wang, Longhu

2017-05-01

The extraction of linarin from Flos chrysanthemi indici by ethanol was investigated. Two modeling techniques, response surface methodology and artificial neural network, were adopted to optimize the process parameters, such as, ethanol concentration, extraction period, extraction frequency, and solvent to material ratio. We showed that both methods provided good predictions, but artificial neural network provided a better and more accurate result. The optimum process parameters include, ethanol concentration of 74%, extraction period of 2 h, extraction three times, solvent to material ratio of 12 mL/g. The experiment yield of linarin was 90.5% that deviated less than 1.6% from that obtained by predicted result. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Extraction Optimization for Obtaining Artemisia capillaris Extract with High Anti-Inflammatory Activity in RAW 264.7 Macrophage Cells

PubMed Central

Jang, Mi; Jeong, Seung-Weon; Kim, Bum-Keun; Kim, Jong-Chan

2015-01-01

Plant extracts have been used as herbal medicines to treat a wide variety of human diseases. We used response surface methodology (RSM) to optimize the Artemisia capillaris Thunb. extraction parameters (extraction temperature, extraction time, and ethanol concentration) for obtaining an extract with high anti-inflammatory activity at the cellular level. The optimum ranges for the extraction parameters were predicted by superimposing 4-dimensional response surface plots of the lipopolysaccharide- (LPS-) induced PGE2 and NO production and by cytotoxicity of A. capillaris Thunb. extracts. The ranges of extraction conditions used for determining the optimal conditions were extraction temperatures of 57–65°C, ethanol concentrations of 45–57%, and extraction times of 5.5–6.8 h. On the basis of the results, a model with a central composite design was considered to be accurate and reliable for predicting the anti-inflammation activity of extracts at the cellular level. These approaches can provide a logical starting point for developing novel anti-inflammatory substances from natural products and will be helpful for the full utilization of A. capillaris Thunb. The crude extract obtained can be used in some A. capillaris Thunb.-related health care products. PMID:26075271

Optimization of methylene blue removal by stable emulsified liquid membrane using Plackett–Burman and Box–Behnken designs of experiments

PubMed Central

Djenouhat, Meriem; Bendebane, Farida; Bahloul, Lynda; Samar, Mohamed E. H.

2018-01-01

The stability of an emulsified liquid membrane composed of Span80 as a surfactant, D2EHPA as an extractant and sulfuric acid as an internal phase was first studied according to different diluents and many operating parameters using the Plackett–Burman design of experiments. Then the removal of methylene blue from an aqueous solution has been carried out using this emulsified liquid membrane at its stability conditions. The effects of operating parameters were analysed from the Box–Behnken design of experiments. The optimization of the extraction has been realized applying the response surface methodology and the results showed that the dye extraction yielding 98.72% was achieved at optimized conditions. PMID:29515841

Optimization of extraction parameters of pentacyclic triterpenoids from Swertia chirata stem using response surface methodology.

PubMed

Pandey, Devendra Kumar; Kaur, Prabhjot

2018-03-01

In the present investigation, pentacyclic triterpenoids were extracted from different parts of Swertia chirata by solid-liquid reflux extraction methods. The total pentacyclic triterpenoids (UA, OA, and BA) in extracted samples were determined by HPTLC method. Preliminary studies showed that stem part contains the maximum pentacyclic triterpenoid and was chosen for further studies. Response surface methodology (RSM) has been employed successfully by solid-liquid reflux extraction methods for the optimization of different extraction variables viz., temperature ( X 1 35-70 °C), extraction time ( X 2 30-60 min), solvent composition ( X 3 20-80%), solvent-to-solid ratio ( X 4 30-60 mlg -1 ), and particle size ( X 5 3-6 mm) on maximum recovery of triterpenoid from stem parts of Swertia chirata . A Plackett-Burman design has been used initially to screen out the three extraction factors viz., particle size, temperature, and solvent composition on yield of triterpenoid. Moreover, central composite design (CCD) was implemented to optimize the significant extraction parameters for maximum triterpenoid yield. Three extraction parameters viz., mean particle size (3 mm), temperature (65 °C), and methanol-ethyl acetate solvent composition (45%) can be considered as significant for the better yield of triterpenoid A second-order polynomial model satisfactorily fitted the experimental data with the R 2 values of 0.98 for the triterpenoid yield ( p  < 0.001), implying good agreement between the experimental triterpenoid yield (3.71%) to the predicted value (3.79%).

Genetic algorithms used for the optimization of light-emitting diodes and solar thermal collectors

NASA Astrophysics Data System (ADS)

Mayer, Alexandre; Bay, Annick; Gaouyat, Lucie; Nicolay, Delphine; Carletti, Timoteo; Deparis, Olivier

2014-09-01

We present a genetic algorithm (GA) we developed for the optimization of light-emitting diodes (LED) and solar thermal collectors. The surface of a LED can be covered by periodic structures whose geometrical and material parameters must be adjusted in order to maximize the extraction of light. The optimization of these parameters by the GA enabled us to get a light-extraction efficiency η of 11.0% from a GaN LED (for comparison, the flat material has a light-extraction efficiency η of only 3.7%). The solar thermal collector we considered consists of a waffle-shaped Al substrate with NiCrOx and SnO2 conformal coatings. We must in this case maximize the solar absorption α while minimizing the thermal emissivity ɛ in the infrared. A multi-objective genetic algorithm has to be implemented in this case in order to determine optimal geometrical parameters. The parameters we obtained using the multi-objective GA enable α~97.8% and ɛ~4.8%, which improves results achieved previously when considering a flat substrate. These two applications demonstrate the interest of genetic algorithms for addressing complex problems in physics.

Extraction optimization of mucilage from Basil (Ocimum basilicum L.) seeds using response surface methodology.

PubMed

Nazir, Sadaf; Wani, Idrees Ahmed; Masoodi, Farooq Ahmad

2017-05-01

Aqueous extraction of basil seed mucilage was optimized using response surface methodology. A Central Composite Rotatable Design (CCRD) for modeling of three independent variables: temperature (40-91 °C); extraction time (1.6-3.3 h) and water/seed ratio (18:1-77:1) was used to study the response for yield. Experimental values for extraction yield ranged from 7.86 to 20.5 g/100 g. Extraction yield was significantly ( P  < 0.05) affected by all the variables. Temperature and water/seed ratio were found to have pronounced effect while the extraction time was found to have minor possible effects. Graphical optimization determined the optimal conditions for the extraction of mucilage. The optimal condition predicted an extraction yield of 20.49 g/100 g at 56.7 °C, 1.6 h, and a water/seed ratio of 66.84:1. Optimal conditions were determined to obtain highest extraction yield. Results indicated that water/seed ratio was the most significant parameter, followed by temperature and time.

Fault Detection of Bearing Systems through EEMD and Optimization Algorithm

PubMed Central

Lee, Dong-Han; Ahn, Jong-Hyo; Koh, Bong-Hwan

2017-01-01

This study proposes a fault detection and diagnosis method for bearing systems using ensemble empirical mode decomposition (EEMD) based feature extraction, in conjunction with particle swarm optimization (PSO), principal component analysis (PCA), and Isomap. First, a mathematical model is assumed to generate vibration signals from damaged bearing components, such as the inner-race, outer-race, and rolling elements. The process of decomposing vibration signals into intrinsic mode functions (IMFs) and extracting statistical features is introduced to develop a damage-sensitive parameter vector. Finally, PCA and Isomap algorithm are used to classify and visualize this parameter vector, to separate damage characteristics from healthy bearing components. Moreover, the PSO-based optimization algorithm improves the classification performance by selecting proper weightings for the parameter vector, to maximize the visualization effect of separating and grouping of parameter vectors in three-dimensional space. PMID:29143772

Aqueous enzymatic extraction of Moringa oleifera oil.

PubMed

Mat Yusoff, Masni; Gordon, Michael H; Ezeh, Onyinye; Niranjan, Keshavan

2016-11-15

This paper reports on the extraction of Moringa oleifera (MO) oil by using aqueous enzymatic extraction (AEE) method. The effect of different process parameters on the oil recovery was discovered by using statistical optimization, besides the effect of selected parameters on the formation of its oil-in-water cream emulsions. Within the pre-determined ranges, the use of pH 4.5, moisture/kernel ratio of 8:1 (w/w), and 300stroke/min shaking speed at 40°C for 1h incubation time resulted in highest oil recovery of approximately 70% (goil/g solvent-extracted oil). These optimized parameters also result in a very thin emulsion layer, indicating minute amount of emulsion formed. Zero oil recovery with thick emulsion were observed when the used aqueous phase was re-utilized for another AEE process. The findings suggest that the critical selection of AEE parameters is key to high oil recovery with minimum emulsion formation thereby lowering the load on the de-emulsification step. Copyright © 2016 Elsevier Ltd. All rights reserved.

User-customized brain computer interfaces using Bayesian optimization

NASA Astrophysics Data System (ADS)

Bashashati, Hossein; Ward, Rabab K.; Bashashati, Ali

2016-04-01

Objective. The brain characteristics of different people are not the same. Brain computer interfaces (BCIs) should thus be customized for each individual person. In motor-imagery based synchronous BCIs, a number of parameters (referred to as hyper-parameters) including the EEG frequency bands, the channels and the time intervals from which the features are extracted should be pre-determined based on each subject’s brain characteristics. Approach. To determine the hyper-parameter values, previous work has relied on manual or semi-automatic methods that are not applicable to high-dimensional search spaces. In this paper, we propose a fully automatic, scalable and computationally inexpensive algorithm that uses Bayesian optimization to tune these hyper-parameters. We then build different classifiers trained on the sets of hyper-parameter values proposed by the Bayesian optimization. A final classifier aggregates the results of the different classifiers. Main Results. We have applied our method to 21 subjects from three BCI competition datasets. We have conducted rigorous statistical tests, and have shown the positive impact of hyper-parameter optimization in improving the accuracy of BCIs. Furthermore, We have compared our results to those reported in the literature. Significance. Unlike the best reported results in the literature, which are based on more sophisticated feature extraction and classification methods, and rely on prestudies to determine the hyper-parameter values, our method has the advantage of being fully automated, uses less sophisticated feature extraction and classification methods, and yields similar or superior results compared to the best performing designs in the literature.

[Optimization of succinic acid fermentation with Actinobacillus succinogenes by response surface methodology].

PubMed

Shen, Naikun; Qin, Yan; Wang, Qingyan; Xie, Nengzhong; Mi, Huizhi; Zhu, Qixia; Liao, Siming; Huang, Ribo

2013-10-01

Succinic acid is an important C4 platform chemical in the synthesis of many commodity and special chemicals. In the present work, different compounds were evaluated for succinic acid production by Actinobacillus succinogenes GXAS 137. Important parameters were screened by the single factor experiment and Plackeet-Burman design. Subsequently, the highest production of succinic acid was approached by the path of steepest ascent. Then, the optimum values of the parameters were obtained by Box-Behnken design. The results show that the important parameters were glucose, yeast extract and MgCO3 concentrations. The optimum condition was as follows (g/L): glucose 70.00, yeast extract 9.20 and MgCO3 58.10. Succinic acid yield reached 47.64 g/L at the optimal condition. Succinic acid increased by 29.14% than that before the optimization (36.89 g/L). Response surface methodology was proven to be a powerful tool to optimize succinic acid production.

Research on Optimal Observation Scale for Damaged Buildings after Earthquake Based on Optimal Feature Space

NASA Astrophysics Data System (ADS)

Chen, J.; Chen, W.; Dou, A.; Li, W.; Sun, Y.

2018-04-01

A new information extraction method of damaged buildings rooted in optimal feature space is put forward on the basis of the traditional object-oriented method. In this new method, ESP (estimate of scale parameter) tool is used to optimize the segmentation of image. Then the distance matrix and minimum separation distance of all kinds of surface features are calculated through sample selection to find the optimal feature space, which is finally applied to extract the image of damaged buildings after earthquake. The overall extraction accuracy reaches 83.1 %, the kappa coefficient 0.813. The new information extraction method greatly improves the extraction accuracy and efficiency, compared with the traditional object-oriented method, and owns a good promotional value in the information extraction of damaged buildings. In addition, the new method can be used for the information extraction of different-resolution images of damaged buildings after earthquake, then to seek the optimal observation scale of damaged buildings through accuracy evaluation. It is supposed that the optimal observation scale of damaged buildings is between 1 m and 1.2 m, which provides a reference for future information extraction of damaged buildings.

Optimization of Reflux Conditions for Total Flavonoid and Total Phenolic Extraction and Enhanced Antioxidant Capacity in Pandan (Pandanus amaryllifolius Roxb.) Using Response Surface Methodology

PubMed Central

Ghasemzadeh, Ali; Jaafar, Hawa Z. E.

2014-01-01

Response surface methodology was applied to optimization of the conditions for reflux extraction of Pandan (Pandanus amaryllifolius Roxb.) in order to achieve a high content of total flavonoids (TF), total phenolics (TP), and high antioxidant capacity (AC) in the extracts. Central composite experimental design with three factors and three levels was employed to consider the effects of the operation parameters, including the methanol concentration (MC, 40%–80%), extraction temperature (ET, 40–70°C), and liquid-to-solid ratio (LS ratio, 20–40 mL/g) on the properties of the extracts. Response surface plots showed that increasing these operation parameters induced the responses significantly. The TF content and AC could be maximized when the extraction conditions (MC, ET, and LS ratio) were 78.8%, 69.5°C, and 32.4 mL/g, respectively, whereas the TP content was optimal when these variables were 75.1%, 70°C, and 31.8 mL/g, respectively. Under these optimum conditions, the experimental TF and TP content and AC were 1.78, 6.601 mg/g DW, and 87.38%, respectively. The optimized model was validated by a comparison of the predicted and experimental values. The experimental values were found to be in agreement with the predicted values, indicating the suitability of the model for optimizing the conditions for the reflux extraction of Pandan. PMID:25147852

Optimization of Supercritical CO2 Extraction of Fish Oil from Viscera of African Catfish (Clarias gariepinus)

PubMed Central

Sarker, Mohamed Zaidul Islam; Selamat, Jinap; Habib, Abu Sayem Md. Ahsan; Ferdosh, Sahena; Akanda, Mohamed Jahurul Haque; Jaffri, Juliana Mohamed

2012-01-01

Fish oil was extracted from the viscera of African Catfish using supercritical carbon dioxide (SC-CO2). A Central Composite Design of Response Surface methodology (RSM) was employed to optimize the SC-CO2 extraction parameters. The oil yield (Y) as response variable was executed against the four independent variables, namely pressure, temperature, flow rate and soaking time. The oil yield varied with the linear, quadratic and interaction of pressure, temperature, flow rate and soaking time. Optimum points were observed within the variables of temperature from 35 °C to 80 °C, pressure from 10 MPa to 40 MPa, flow rate from 1 mL/min to 3 mL/min and soaking time from 1 h to 4 h. However, the extraction parameters were found to be optimized at temperature 57.5 °C, pressure 40 MPa, flow rate 2.0 mL/min and soaking time 2.5 h. At this optimized condition, the highest oil yields were found to be 67.0% (g oil/100 g sample on dry basis) in the viscera of catfish which was reasonable to the yields of 78.0% extracted using the Soxhlet method. PMID:23109854

Optimization of an innovative approach involving mechanical activation and acid digestion for the extraction of lithium from lepidolite

NASA Astrophysics Data System (ADS)

Vieceli, Nathália; Nogueira, Carlos A.; Pereira, Manuel F. C.; Durão, Fernando O.; Guimarães, Carlos; Margarido, Fernanda

2018-01-01

The recovery of lithium from hard rock minerals has received increased attention given the high demand for this element. Therefore, this study optimized an innovative process, which does not require a high-temperature calcination step, for lithium extraction from lepidolite. Mechanical activation and acid digestion were suggested as crucial process parameters, and experimental design and response-surface methodology were applied to model and optimize the proposed lithium extraction process. The promoting effect of amorphization and the formation of lithium sulfate hydrate on lithium extraction yield were assessed. Several factor combinations led to extraction yields that exceeded 90%, indicating that the proposed process is an effective approach for lithium recovery.

Extracellular voltage threshold settings can be tuned for optimal encoding of movement and stimulus parameters

NASA Astrophysics Data System (ADS)

Oby, Emily R.; Perel, Sagi; Sadtler, Patrick T.; Ruff, Douglas A.; Mischel, Jessica L.; Montez, David F.; Cohen, Marlene R.; Batista, Aaron P.; Chase, Steven M.

2016-06-01

Objective. A traditional goal of neural recording with extracellular electrodes is to isolate action potential waveforms of an individual neuron. Recently, in brain-computer interfaces (BCIs), it has been recognized that threshold crossing events of the voltage waveform also convey rich information. To date, the threshold for detecting threshold crossings has been selected to preserve single-neuron isolation. However, the optimal threshold for single-neuron identification is not necessarily the optimal threshold for information extraction. Here we introduce a procedure to determine the best threshold for extracting information from extracellular recordings. We apply this procedure in two distinct contexts: the encoding of kinematic parameters from neural activity in primary motor cortex (M1), and visual stimulus parameters from neural activity in primary visual cortex (V1). Approach. We record extracellularly from multi-electrode arrays implanted in M1 or V1 in monkeys. Then, we systematically sweep the voltage detection threshold and quantify the information conveyed by the corresponding threshold crossings. Main Results. The optimal threshold depends on the desired information. In M1, velocity is optimally encoded at higher thresholds than speed; in both cases the optimal thresholds are lower than are typically used in BCI applications. In V1, information about the orientation of a visual stimulus is optimally encoded at higher thresholds than is visual contrast. A conceptual model explains these results as a consequence of cortical topography. Significance. How neural signals are processed impacts the information that can be extracted from them. Both the type and quality of information contained in threshold crossings depend on the threshold setting. There is more information available in these signals than is typically extracted. Adjusting the detection threshold to the parameter of interest in a BCI context should improve our ability to decode motor intent, and thus enhance BCI control. Further, by sweeping the detection threshold, one can gain insights into the topographic organization of the nearby neural tissue.

Extracellular voltage threshold settings can be tuned for optimal encoding of movement and stimulus parameters

PubMed Central

Oby, Emily R; Perel, Sagi; Sadtler, Patrick T; Ruff, Douglas A; Mischel, Jessica L; Montez, David F; Cohen, Marlene R; Batista, Aaron P; Chase, Steven M

2018-01-01

Objective A traditional goal of neural recording with extracellular electrodes is to isolate action potential waveforms of an individual neuron. Recently, in brain–computer interfaces (BCIs), it has been recognized that threshold crossing events of the voltage waveform also convey rich information. To date, the threshold for detecting threshold crossings has been selected to preserve single-neuron isolation. However, the optimal threshold for single-neuron identification is not necessarily the optimal threshold for information extraction. Here we introduce a procedure to determine the best threshold for extracting information from extracellular recordings. We apply this procedure in two distinct contexts: the encoding of kinematic parameters from neural activity in primary motor cortex (M1), and visual stimulus parameters from neural activity in primary visual cortex (V1). Approach We record extracellularly from multi-electrode arrays implanted in M1 or V1 in monkeys. Then, we systematically sweep the voltage detection threshold and quantify the information conveyed by the corresponding threshold crossings. Main Results The optimal threshold depends on the desired information. In M1, velocity is optimally encoded at higher thresholds than speed; in both cases the optimal thresholds are lower than are typically used in BCI applications. In V1, information about the orientation of a visual stimulus is optimally encoded at higher thresholds than is visual contrast. A conceptual model explains these results as a consequence of cortical topography. Significance How neural signals are processed impacts the information that can be extracted from them. Both the type and quality of information contained in threshold crossings depend on the threshold setting. There is more information available in these signals than is typically extracted. Adjusting the detection threshold to the parameter of interest in a BCI context should improve our ability to decode motor intent, and thus enhance BCI control. Further, by sweeping the detection threshold, one can gain insights into the topographic organization of the nearby neural tissue. PMID:27097901

Extracellular voltage threshold settings can be tuned for optimal encoding of movement and stimulus parameters.

PubMed

Oby, Emily R; Perel, Sagi; Sadtler, Patrick T; Ruff, Douglas A; Mischel, Jessica L; Montez, David F; Cohen, Marlene R; Batista, Aaron P; Chase, Steven M

2016-06-01

A traditional goal of neural recording with extracellular electrodes is to isolate action potential waveforms of an individual neuron. Recently, in brain-computer interfaces (BCIs), it has been recognized that threshold crossing events of the voltage waveform also convey rich information. To date, the threshold for detecting threshold crossings has been selected to preserve single-neuron isolation. However, the optimal threshold for single-neuron identification is not necessarily the optimal threshold for information extraction. Here we introduce a procedure to determine the best threshold for extracting information from extracellular recordings. We apply this procedure in two distinct contexts: the encoding of kinematic parameters from neural activity in primary motor cortex (M1), and visual stimulus parameters from neural activity in primary visual cortex (V1). We record extracellularly from multi-electrode arrays implanted in M1 or V1 in monkeys. Then, we systematically sweep the voltage detection threshold and quantify the information conveyed by the corresponding threshold crossings. The optimal threshold depends on the desired information. In M1, velocity is optimally encoded at higher thresholds than speed; in both cases the optimal thresholds are lower than are typically used in BCI applications. In V1, information about the orientation of a visual stimulus is optimally encoded at higher thresholds than is visual contrast. A conceptual model explains these results as a consequence of cortical topography. How neural signals are processed impacts the information that can be extracted from them. Both the type and quality of information contained in threshold crossings depend on the threshold setting. There is more information available in these signals than is typically extracted. Adjusting the detection threshold to the parameter of interest in a BCI context should improve our ability to decode motor intent, and thus enhance BCI control. Further, by sweeping the detection threshold, one can gain insights into the topographic organization of the nearby neural tissue.

[Study on new extraction technology of astragaloside IV].

PubMed

Sun, Haiyan; Guan, Su; Huang, Min

2005-08-01

To explore the possibility and the optimal extraction technology of astragaloside IV by SFE-CO2. According the content of astragaloside IV, the optimum extraction technology parameters such as extraction temperature, pressure, extraction time, velocity of fluid and co-solvent were investigated and the result was compared with that of water extraction. The optimum technical parameters were as follows: Extracting pressure 40 Mpa, temperature 45 degrees C, extracting time 2h, co-solvent was 95% ethanol and its dosage was 4ml/g, the ratio of CO2 fluid was 10 kg/kg x h. Extraction technology of astragaloside IV by SFE-CO2 is reliable, stable.

Intensification of marrubiin concentration by optimization of microwave-assisted (low CO2 yielding) extraction process for Marrubium vulgare using central composite design and antioxidant evaluation.

PubMed

Mittal, Vineet; Nanda, Arun

2017-12-01

Marrubium vulgare Linn (Lamiaceae) was generally extracted by conventional methods with low yield of marrubiin; these processes were not considered environment friendly. This study extracts the whole plant of M. vulgare by microwave assisted extraction (MAE) and optimizes the effect of various extraction parameters on the marrubiin yield by using Central Composite Design (CCD). The selected medicinal plant was extracted using ethanol: water (1:1) as solvent by MAE. The plant material was also extracted using a Soxhlet and the various extracts were analyzed by HPTLC to quantify the marrubiin concentration. The optimized conditions for the microwave-assisted extraction of selected medicinal plant was microwave power of 539 W, irradiation time of 373 s and solvent to drug ratio, 32 mL per g of the drug. The marrubiin concentration in MAE almost doubled relative to the traditional method (0.69 ± 0.08 to 1.35 ± 0.04%). The IC 50 for DPPH was reduced to 66.28 ± 0.6 μg/mL as compared to conventional extract (84.14 ± 0.7 μg/mL). The scanning electron micrographs of the treated and untreated drug samples further support the results. The CCD can be successfully applied to optimize the extraction parameters (MAE) for M. vulgare. Moreover, in terms of environmental impact, the MAE technique could be assumed as a 'Green approach' because the MAE approach for extraction of plant released only 92.3 g of CO 2 as compared to 3207.6 g CO 2 using the Soxhlet method of extraction.

Optimization study of Chromalaena odorata essential oil extracted using solventless extraction technique

NASA Astrophysics Data System (ADS)

Nasshorudin, Dalila; Ahmad, Muhammad Syarhabil; Mamat, Awang Soh; Rosli, Suraya

2015-05-01

Solventless extraction process of Chromalaena odorata using reduced pressure and temperature has been investigated. The percentage yield of essential oil produce was calculated for every experiment with different experimental condition. The effect of different parameters, such as temperature and extraction time on the yield was investigated using the Response Surface Methodology (RSM) through Central Composite Design (CCD). The temperature and extraction time were found to have significant effect on the yield of extract. A final essential oil yield was 0.095% could be extracted under the following optimized conditions; a temperature of 80 °C and a time of 8 hours.

Supercritical Fluid Extraction of Pyrrolidine Alkaloid from Leaves of Piper amalago L.

PubMed Central

Filho, L. C.; Faiões, V. S.; Cunha-Júnior, E. F.; Torres-Santos, E. C.; Cortez, D. A. G.

2017-01-01

Supercritical fluid extraction was used to extract the alkaloid N-[7-(3′,4′-methylenedioxyphenyl)-2(Z),4(Z)-heptadienoyl]pyrrolidine from leaves of Piper amalago L. A three-level orthogonal array design matrix, OAD OA9(34), was used for optimization of the parameters of supercritical extraction of the alkaloid, employing supercritical carbon dioxide: extraction time (20, 40, and 60 min), temperature (40, 50, and 60°C), pressure (150, 200, and 250 bar), and the use of cosolvents (ethanol, methanol, and propyleneglycol). All parameters had significant effect on the alkaloid yield. The alkaloid yield after 60 min of extraction without cosolvents at 9 different conditions (32) in terms of temperature (40, 50, and 60°C) and pressure (150, 200, and 250 bar) was also evaluated. The optimal yield (≈3.8 mg g−1) was obtained with supercritical CO2 + methanol (5% v : v) at 40°C and 200 bar for 60 min of extraction. PMID:28539966

Ultrasound-assisted extraction of Mangiferin from Mango (Mangifera indica L.) leaves using response surface methodology.

PubMed

Zou, Tang-Bin; Xia, En-Qin; He, Tai-Ping; Huang, Ming-Yuan; Jia, Qing; Li, Hua-Wen

2014-01-27

Mangiferin is a xanthone widely distributed in higher plants showing antioxidative, antiviral, anticancer, antidiabetic, immunomodulatory, hepatoprotective and analgesic effects. In the present study, an ultrasonic-assisted extraction method was developed for the effective extraction of mangiferin from mango leaves. Some parameters such as ethanol concentration, liquid-to-solid ratio, extraction temperature, and extraction time were optimized by single-factor experiment and response surface methodology. The optimal extraction conditions were 44% ethanol, the liquid-to-solid ratio was 38:1, and extraction for 19.2 min at 60 °C under ultrasound irradiation of 200 W. Under optimal conditions, the yield of mangiferin was 58.46 ± 1.27 mg/g. The results obtained are helpful for the full utilization of mango leaves, and also indicated that ultrasonic-assisted extraction is a very useful method for the extraction of mangiferin from plant materials.

Small-signal modeling with direct parameter extraction for impact ionization effect in high-electron-mobility transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guan, He; Lv, Hongliang; Guo, Hui, E-mail: hguan@stu.xidian.edu.cn

2015-11-21

Impact ionization affects the radio-frequency (RF) behavior of high-electron-mobility transistors (HEMTs), which have narrow-bandgap semiconductor channels, and this necessitates complex parameter extraction procedures for HEMT modeling. In this paper, an enhanced small-signal equivalent circuit model is developed to investigate the impact ionization, and an improved method is presented in detail for direct extraction of intrinsic parameters using two-step measurements in low-frequency and high-frequency regimes. The practicability of the enhanced model and the proposed direct parameter extraction method are verified by comparing the simulated S-parameters with published experimental data from an InAs/AlSb HEMT operating over a wide frequency range. The resultsmore » demonstrate that the enhanced model with optimal intrinsic parameter values that were obtained by the direct extraction approach can effectively characterize the effects of impact ionization on the RF performance of HEMTs.« less

Application of response surface methodology to optimize microwave-assisted extraction of silymarin from milk thistle seeds

USDA-ARS?s Scientific Manuscript database

Several parameters of Microwave-assisted extraction (MAE) including extraction time, extraction temperature, ethanol concentration and solid-liquid ratio were selected to describe the MAE processing. The silybin content, measured by an UV-Vis spectrophotometry, was considered as the silymarin yield....

Encapsulation of brewing yeast in alginate/chitosan matrix: lab-scale optimization of lager beer fermentation.

PubMed

Naydenova, Vessela; Badova, Mariyana; Vassilev, Stoyan; Iliev, Vasil; Kaneva, Maria; Kostov, Georgi

2014-03-04

Two mathematical models were developed for studying the effect of main fermentation temperature ( T MF ), immobilized cell mass ( M IC ) and original wort extract (OE) on beer fermentation with alginate-chitosan microcapsules with a liquid core. During the experiments, the investigated parameters were varied in order to find the optimal conditions for beer fermentation with immobilized cells. The basic beer characteristics, i.e. extract, ethanol, biomass concentration, pH and colour, as well as the concentration of aldehydes and vicinal diketones, were measured. The results suggested that the process parameters represented a powerful tool in controlling the fermentation time. Subsequently, the optimized process parameters were used to produce beer in laboratory batch fermentation. The system productivity was also investigated and the data were used for the development of another mathematical model.

Encapsulation of brewing yeast in alginate/chitosan matrix: lab-scale optimization of lager beer fermentation

PubMed Central

Naydenova, Vessela; Badova, Mariyana; Vassilev, Stoyan; Iliev, Vasil; Kaneva, Maria; Kostov, Georgi

2014-01-01

Two mathematical models were developed for studying the effect of main fermentation temperature (T MF), immobilized cell mass (M IC) and original wort extract (OE) on beer fermentation with alginate-chitosan microcapsules with a liquid core. During the experiments, the investigated parameters were varied in order to find the optimal conditions for beer fermentation with immobilized cells. The basic beer characteristics, i.e. extract, ethanol, biomass concentration, pH and colour, as well as the concentration of aldehydes and vicinal diketones, were measured. The results suggested that the process parameters represented a powerful tool in controlling the fermentation time. Subsequently, the optimized process parameters were used to produce beer in laboratory batch fermentation. The system productivity was also investigated and the data were used for the development of another mathematical model. PMID:26019512

Extracting TSK-type Neuro-Fuzzy model using the Hunting search algorithm

NASA Astrophysics Data System (ADS)

Bouzaida, Sana; Sakly, Anis; M'Sahli, Faouzi

2014-01-01

This paper proposes a Takagi-Sugeno-Kang (TSK) type Neuro-Fuzzy model tuned by a novel metaheuristic optimization algorithm called Hunting Search (HuS). The HuS algorithm is derived based on a model of group hunting of animals such as lions, wolves, and dolphins when looking for a prey. In this study, the structure and parameters of the fuzzy model are encoded into a particle. Thus, the optimal structure and parameters are achieved simultaneously. The proposed method was demonstrated through modeling and control problems, and the results have been compared with other optimization techniques. The comparisons indicate that the proposed method represents a powerful search approach and an effective optimization technique as it can extract the accurate TSK fuzzy model with an appropriate number of rules.

Study on Process Parameters of Extraction of γ-aminobutyric Acid Instant Moringa oleifera Powder

NASA Astrophysics Data System (ADS)

Tiaokun, Fu; Suhui, Zhang; Neng, Liu; Jihua, Li; Shaodan, Peng; Changqing, Guo; Wei, Zhou

2017-12-01

To preliminary optimize the extraction of γ-aminobutyric acid instant tea powder from Moringa oleifera leaves,taking γ-aminobutyric acid Moringa oleifera leaves as raw material and pure water as extraction solvent and GABA content as the main evaluation index,the effects of extraction temperature, ratio of liquid to material and extraction time on biochemical components and sensory qualities of Moringa oleifera leaves extractor was studied by using one-factor-at-a-time experiment.The results showed shat the optimal extraction conditions for γ-aminobutyric acid instant tea powder were extraction temperature of 60 °C, material-to-water ration of 1:10 and extraction time of 40 min.

[Optimization for supercritical CO2 extraction with response surface methodology and component analysis of Sapindus mukorossi oil].

PubMed

Wu, Yan; Xiao, Xin-yu; Ge, Fa-huan

2012-02-01

To study the extraction conditions of Sapindus mukorossi oil by Supercritical CO2 Extraction and identify its components. Optimized SFE-CO2 Extraction by response surface methodology and used GC-MS to analysie Sapindus mukorossi oil compounds. Established the model of an equation for the extraction rate of Sapindus mukorossi oil by Supercritical CO2 Extraction, and the optimal parameters for the Supercritical CO2 Extraction determined by the equation were: the extraction pressure was 30 MPa, temperature was 40 degrees C; The separation I pressure was 14 MPa, temperature was 45 degrees C; The separation II pressure was 6 MPa, temperature was 40 degrees C; The extraction time was 60 min and the extraction rate of Sapindus mukorossi oil of 17.58%. 22 main compounds of Sapindus mukorossi oil extracted by supercritical CO2 were identified by GC-MS, unsaturated fatty acids were 86.59%. This process is reliable, safe and with simple operation, and can be used for the extraction of Sapindus mukorossi oil.

Extraction of Antioxidant Phenolic Compounds from Brewer’s Spent Grain: Optimization and Kinetics Modeling

PubMed Central

Sologubik, Carlos A.; Fernández, María B.; Manrique, Guillermo D.

2018-01-01

The kinetics of polyphenol extraction from brewer’s spent grain (BSG), using a batch system, ultrasound assistance, and microwave assistance and the evolution of antioxidant capacity of these extracts over time, were studied. The main parameters of extraction employed in the batch system were evaluated, and, by applying response surface analysis, the following optimal conditions were obtained: Liquid/solid ratio of 30:1 mL/g at 80 °C, using 72% (v/v) ethanol:water as the solvent system. Under these optimized conditions, ultrasound assistance demonstrated the highest extraction rate and equilibrium yield, as well as shortest extraction times, followed by microwave assistance. Among the mathematical models used, Patricelli’s model proved the most suitable for describing the extraction kinetics for each method tested, and is therefore able to predict the response values and estimate the extraction rates and potential maximum yields in each case. PMID:29570683

The optimal extracting process, manufacturing technique and biological evaluation of Lithospermum erythrorhizon microcapsules.

PubMed

Lou, Ching-Wen; Chang, Chiung-Yun; Wu, Zong-Han; Lin, Jia-Horng

2015-03-01

Lithospermum erythrorhizon has been proved to be anti-inflammatory, by recent studies. This study extracts L. erythrorhizon with ethanol at various solid-liquid ratios (1:4, 1:6, 1:8, and 1:12), extraction temperatures (40°C, 50°C, and 60°C), and extraction times (4, 24 and 36h) in order to determine the optimal parameters. The optimal parameters are extracted and condensed into L. erythrorhizon extract; then the antibacterial property and cell compatibility of L. erythrorhizon extract are evaluated with various concentrations of L. erythrorhizon extract solution and different weights of L. erythrorhizon extract powder, respectively. The concentrations of solution are 0.1mg/ml, 0.5mg/ml, 1.0mg/ml, and 2.0mg/ml and ethanol is chosen as the solvent, and different weights of powder are varied as 0.1mg, 1.0mg, 2.0mg, and 10mg. The cell viability test and animal study are performed on L. erythrorhizon microcapsules. The experiment results show that sodium alginate/pectin L. erythrorhizon (SPL) microcapsules possess a 120-hour drug release. The results of cell viability and animal study show that the L. erythrorhizon microcapsules (SPL) have good cell viability (99%) and can help in the wound healing process (the wound size reduction reaches 91.3% on Day 11). Copyright © 2014 Elsevier B.V. All rights reserved.

Optimization of microwave-assisted extraction of protopine and allocryptopine from stems of Macleaya cordata (Willd) R. Br. using response surface methodology.

PubMed

Zhong, Ming; Huang, Ke-Long; Zeng, Jian-Guo; Li, Shuang; She, Jin-Ming; Li, Guiyin; Zhang, Li

2010-07-01

The purpose of the research was to investigate the multiple response optimizations for the extraction of protopine and allocryptopine from the stems of Macleaya cordata (Willd) R. Br. by using microwave-assisted extraction (MAE). A three-level, three-factor Box-Behnken design of response surface methodology was used to develop response model, and desirability function was employed to optimize the effects of main extraction parameters. Three variables, ethanol concentration (20-80%, v/v), extraction temperature (30-70 degrees C) and solvent/solid ratio (10:1 to 30:1, mL/g), were investigated in this study. The results showed that the optimum parameters of MAE were ethanol concentration of 45.2 % (v/v), extraction temperature of 54.7 degrees C and solvent/solid ratio of 20.4:1 (mL/g). Under these conditions, the extraction yields of protopine and allocryptopine were 89.4 and 102.0%, respectively, and the extracta sicca yield was 12.5%. The combination use of response surface methodology, Box-Behnken design and the appropriate desirability function could provide an insight into a lab-scale MAE process, and help to develop procedures for commercial production of active ingredients from medical plants.

Optimization of β-cyclodextrin-based flavonol extraction from apple pomace using response surface methodology.

PubMed

Parmar, Indu; Sharma, Sowmya; Rupasinghe, H P Vasantha

2015-04-01

The present study investigated five cyclodextrins (CDs) for the extraction of flavonols from apple pomace powder and optimized β-CD based extraction of total flavonols using response surface methodology. A 2(3) central composite design with β-CD concentration (0-5 g 100 mL(-1)), extraction temperature (20-72 °C), extraction time (6-48 h) and second-order quadratic model for the total flavonol yield (mg 100 g(-1) DM) was selected to generate the response surface curves. The optimal conditions obtained were: β-CD concentration, 2.8 g 100 mL(-1); extraction temperature, 45 °C and extraction time, 25.6 h that predicted the extraction of 166.6 mg total flavonols 100 g(-1) DM. The predicted amount was comparable to the experimental amount of 151.5 mg total flavonols 100 g(-1) DM obtained from optimal β-CD based parameters, thereby giving a low absolute error and adequacy of fitted model. In addition, the results from optimized extraction conditions showed values similar to those obtained through previously established solvent based sonication assisted flavonol extraction procedure. To the best of our knowledge, this is the first study to optimize aqueous β-CD based flavonol extraction which presents an environmentally safe method for value-addition to under-utilized bio resources.

Highly Selective and Considerable Subcritical Butane Extraction to Separate Abamectin in Green Tea.

PubMed

Zhang, Yating; Gu, Lingbiao; Wang, Fei; Kong, Lingjun; Pang, Huili; Qin, Guangyong

2017-06-01

We specially carried out the subcritical butane extraction to separate abamectin from tea leaves. Four parameters, such as extraction temperature, extraction time, number of extraction cycles, and solid-liquid ratio were studied and optimized through the response surface methodology with design matrix developed by Box-Behnken. Seventeen experiments with three various factors and three variable levels were employed to investigate the effect of these parameters on the extraction of abamectin. Besides, catechins, theanine, caffeine, and aroma components were determined by both high-performance liquid chromatography and gas chromatography-mass spectrometry to evaluate the tea quality before and after the extraction. The results showed that the extraction temperature was the uppermost parameter compared with others. The optimal extraction conditions selected as follows: extraction temperature, 42°C; number of extraction cycles and extraction time, 1 and 30 min, respectively; and solid-liquid ratio, 1:10. Based on the above study, the separation efficiency of abamectin was up to 93.95%. It is notable that there has a quite low loss rate, including the negligible damage of aroma components, the bits reduce of catechins within the range of 0.7%-13.1%, and a handful lessen of caffeine and theanine of 1.81% and 2.6%, respectively. The proposed method suggested subcritical butane possesses solubility for lipid-soluble pesticides, and since most of the pesticides are attached to the surfaces of tea, thus the as-applied method was successfully effective to separate abamectin because of the so practical and promising method.

Extraction of gelatin from salmon (Salmo salar) fish skin using trypsin-aided process: optimization by Plackett-Burman and response surface methodological approaches.

PubMed

Fan, HuiYin; Dumont, Marie-Josée; Simpson, Benjamin K

2017-11-01

Gelatin from salmon ( Salmo salar ) skin with high molecular weight protein chains ( α -chains) was extracted using trypsin-aided process. Response surface methodology was used to optimise the extraction parameters. Yield, hydroxyproline content and protein electrophoretic profile via sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of gelatin were used as responses in the optimization study. The optimum conditions were determined as: trypsin concentration at 1.49 U/g; extraction temperature at 45 °C; and extraction time at 6 h 16 min. This response surface optimized model was significant and produced an experimental value (202.04 ± 8.64%) in good agreement with the predicted value (204.19%). Twofold higher yields of gelatin with high molecular weight protein chains were achieved in the optimized process with trypsin treatment when compared to the process without trypsin.

Optimization of plasma parameters with magnetic filter field and pressure to maximize H{sup −} ion density in a negative hydrogen ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cho, Won-Hwi; Dang, Jeong-Jeung; Kim, June Young

2016-02-15

Transverse magnetic filter field as well as operating pressure is considered to be an important control knob to enhance negative hydrogen ion production via plasma parameter optimization in volume-produced negative hydrogen ion sources. Stronger filter field to reduce electron temperature sufficiently in the extraction region is favorable, but generally known to be limited by electron density drop near the extraction region. In this study, unexpected electron density increase instead of density drop is observed in front of the extraction region when the applied transverse filter field increases monotonically toward the extraction aperture. Measurements of plasma parameters with a movable Langmuirmore » probe indicate that the increased electron density may be caused by low energy electron accumulation in the filter region decreasing perpendicular diffusion coefficients across the increasing filter field. Negative hydrogen ion populations are estimated from the measured profiles of electron temperatures and densities and confirmed to be consistent with laser photo-detachment measurements of the H{sup −} populations for various filter field strengths and pressures. Enhanced H{sup −} population near the extraction region due to the increased low energy electrons in the filter region may be utilized to increase negative hydrogen beam currents by moving the extraction position accordingly. This new finding can be used to design efficient H{sup −} sources with an optimal filtering system by maximizing high energy electron filtering while keeping low energy electrons available in the extraction region.« less

Research on Optimization of GLCM Parameter in Cell Classification

NASA Astrophysics Data System (ADS)

Zhang, Xi-Kun; Hou, Jie; Hu, Xin-Hua

2016-05-01

Real-time classification of biological cells according to their 3D morphology is highly desired in a flow cytometer setting. Gray level co-occurrence matrix (GLCM) algorithm has been developed to extract feature parameters from measured diffraction images ,which are too complicated to coordinate with the real-time system for a large amount of calculation. An optimization of GLCM algorithm is provided based on correlation analysis of GLCM parameters. The results of GLCM analysis and subsequent classification demonstrate optimized method can lower the time complexity significantly without loss of classification accuracy.

Optimization of antimicrobial activity of flavonoid extracts from pomelo (Citrus grandis) peel as food wrap

NASA Astrophysics Data System (ADS)

Sugumaran, Kamaraj; Zakaria, Nur Zatul-'Iffah; Abdullah, Rozaini; Jalani, Nur Syazana; Zati-Hanani, Sharifah; Ibrahim, Roshita; Zakaria, Zarina

2017-09-01

This study has been carried out to optimize an antimicrobial activity of flavonoid extract from pomelo peels against Staphyloccus aureus (S. aureus). A comparative analysis of total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity were done on two parts of peel which are albedo (inner peel) and flavedo (outer peel). Based on the result obtained, flavedo showed higher TPC, TFC and antioxidant activity (304.20 mg /g, 74.30 mg /g and 46.86 % respectively) when compared to albedo (150.98 mg /g, 52.97 mg /g and 24.70 % respectively). The effects of different extract concentration and pH on inhibition zone of S. aureus were optimized using Research Surface Methodology (RSM). The optimal condition of parameters was obtained based on the maximum zone of S. aureus inhibition at extract concentration of 200 mg/mL and pH of 4.8. The antimicrobial film has been developed by using optimal conditions by incorporating the flavonoid extract into chitosan polymer.

Response Surface Methodology for Ultrasound-Assisted Extraction of Astaxanthin from Haematococcus pluvialis

PubMed Central

Zou, Tang-Bin; Jia, Qing; Li, Hua-Wen; Wang, Chang-Xiu; Wu, Hong-Fu

2013-01-01

Astaxanthin is a novel carotenoid nutraceutical occurring in many crustaceans and red yeasts. It has exhibited various biological activities including prevention or amelioration of cardiovascular disease, gastric ulcer, hypertension, and diabetic nephropathy. In this study, ultrasound-assisted extraction was developed for the effective extraction of astaxanthin from Haematococcus pluvialis. Some parameters such as extraction solvent, liquid-to-solid ratio, extraction temperature, and extraction time were optimized by single-factor experiment and response surface methodology. The optimal extraction conditions were 48.0% ethanol in ethyl acetate, the liquid-to-solid ratio was 20:1 (mL/g), and extraction for 16.0 min at 41.1 °C under ultrasound irradiation of 200 W. Under optimal conditions, the yield of astaxanthin was 27.58 ± 0.40 mg/g. The results obtained are beneficial for the full utilization of Haematococcus pluvialis, which also indicated that ultrasound-assisted extraction is a very useful method for extracting astaxanthin from marine life. PMID:23697948

Process optimization and analysis of microwave assisted extraction of pectin from dragon fruit peel.

PubMed

Thirugnanasambandham, K; Sivakumar, V; Prakash Maran, J

2014-11-04

Microwave assisted extraction (MAE) technique was employed for the extraction of pectin from dragon fruit peel. The extracting parameters were optimized by using four-variable-three-level Box-Behnken design (BBD) coupled with response surface methodology (RSM). RSM analysis indicated good correspondence between experimental and predicted values. 3D response surface plots were used to study the interactive effects of process variables on extraction of pectin. The optimum extraction conditions for the maximum yield of pectin were power of 400 W, temperature of 45 °C, extracting time of 20 min and solid-liquid ratio of 24 g/mL. Under these conditions, 7.5% of pectin was extracted. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modelling space-based integral-field spectrographs and their application to Type Ia supernova cosmology

NASA Astrophysics Data System (ADS)

Shukla, Hemant; Bonissent, Alain

2017-04-01

We present the parameterized simulation of an integral-field unit (IFU) slicer spectrograph and its applications in spectroscopic studies, namely, for probing dark energy with type Ia supernovae. The simulation suite is called the fast-slicer IFU simulator (FISim). The data flow of FISim realistically models the optics of the IFU along with the propagation effects, including cosmological, zodiacal, instrumentation and detector effects. FISim simulates the spectrum extraction by computing the error matrix on the extracted spectrum. The applications for Type Ia supernova spectroscopy are used to establish the efficacy of the simulator in exploring the wider parametric space, in order to optimize the science and mission requirements. The input spectral models utilize the observables such as the optical depth and velocity of the Si II absorption feature in the supernova spectrum as the measured parameters for various studies. Using FISim, we introduce a mechanism for preserving the complete state of a system, called the partial p/partial f matrix, which allows for compression, reconstruction and spectrum extraction, we introduce a novel and efficient method for spectrum extraction, called super-optimal spectrum extraction, and we conduct various studies such as the optimal point spread function, optimal resolution, parameter estimation, etc. We demonstrate that for space-based telescopes, the optimal resolution lies in the region near R ˜ 117 for read noise of 1 e- and 7 e- using a 400 km s-1 error threshold on the Si II velocity.

Comparison of microwave-assisted and conventional extraction of mangiferin from mango (Mangifera indica L.) leaves.

PubMed

Zou, Tangbin; Wu, Hongfu; Li, Huawen; Jia, Qing; Song, Gang

2013-10-01

Mangiferin is the main bioactive component in mango leaves, which possesses anti-inflammatory, antioxidative, antidiabetic, immunomodulatory, and antitumor activities. In the present study, a microwave-assisted extraction method was developed for the extraction of mangiferin from mango leaves. Some parameters such as ethanol concentration, liquid-to-solid ratio, microwave power, and extraction time were optimized by single-factor experiments and response surface methodology. The optimal extraction conditions were 45% ethanol, liquid-to-solid ratio of 30:1 (mL/g), and extraction time of 123 s under microwave irradiation of 474 W. Under optimal conditions, the yield of mangiferin was 36.10 ± 0.72 mg/g, significantly higher than that of conventional extraction. The results obtained are beneficial for the full utilization of mango leaves and also indicate that microwave-assisted extraction is a very useful method for extracting mangiferin from plant materials. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimization of ultrasonic circulating extraction of samara oil from Acer saccharum using combination of Plackett-Burman design and Box-Behnken design.

PubMed

Chen, Fengli; Zhang, Qiang; Fei, Shimin; Gu, Huiyan; Yang, Lei

2017-03-01

In this study, ultrasonic circulating extraction (UCE) technique was firstly and successfully applied for extraction of samara oil from Acer saccharum. The extraction kinetics were fitted and described, and the extraction mechanism was discussed. Through comparison, n-hexane was selected as the extraction solvent, the influence of solvent type on the responses was detailedly interpreted based on the influence of their properties on the occurrence and intensity of cavitation. Seven parameters potentially influencing the extraction yield of samara oil and content of nervonic acid, including ultrasound irradiation time, ultrasound irradiation power, ultrasound temperature, liquid-solid ratio, soaking time, particle size and stirring rate, were screened through Plackett-Burman design to determine the significant variables. Then, three parameters performed statistically significant, including liquid-solid ratio, ultrasound irradiation time and ultrasound irradiation power, were further optimized using Box-Behnken design to predict optimum extraction conditions. Satisfactory yield of samara oil (11.72±0.38%) and content of nervonic acid (5.28±0.18%) were achieved using the optimal conditions. 1% proportion of ethanol in extraction solvent, 120°C of drying temperature and 6.4% moisture were selected and applied for effective extraction. There were no distinct differences in the physicochemical properties of samara oil obtained by UCE and Soxhlet extraction, and the samara oil obtained by UCE exhibited better antioxidant activities. Therefore, UCE method has enormous potential for efficient extraction of edible oil with high quality from plant materials. Copyright © 2016 Elsevier B.V. All rights reserved.

Ultrasound-assisted three-phase partitioning of polyphenol oxidase from potato peel (Solanum tuberosum).

PubMed

Niphadkar, Sonali S; Rathod, Virendra K

2015-01-01

Conventional three phase partitioning (TPP) and ultrasound assisted three phase partitioning (UATPP) were optimized for achieving the maximum extraction and purification of polyphenol oxidase (PPO) from waste potato peels. Different process parameters such as ammonium sulfate (NH4)2SO4 concentration, crude extract to t-butanol ratio, time, temperature and pH were studied for conventional TPP. Except agitation speed, the similar parameters were also optimized for UATPP. Further additional parameters were also studied for UATPP viz. irradiation time at different frequencies, duty cycle and, rated power in order to obtain the maximum purification factor and recovery of PPO. The optimized conditions for conventional TPP were (NH4)2SO4 0-40% (w/v), extract to t-butanol ratio 1:1 (v/v), time 40 min and pH 7 at 30°C. These conditions provided 6.3 purification factor and 70% recovery of PPO from bottom phase. On the other hand, UATPP gives maximum purification fold of 19.7 with 98.3% recovery under optimized parameters which includes (NH4)2SO4 0-40% (w/v), crude extract to t-butanol ratio 1: 1 (v/v) pH 7, irradiation time 5 min with 25 kHz, duty cycle 40% and rated power 150W at 30°C. UATPP delivers higher purification factor and % recovery of PPO along with reduced operation time from 40 min to 5 min when compared with TPP. SDS PAGE showed partial purification of PPO enzyme with UATPP with molecular weight in the range of 26-36 kDa. Results reveal that UATPP would be an attractive option for the isolation and purification of PPO without need of multiple steps. © 2015 American Institute of Chemical Engineers.

Extraction and analysis of intact glucosinolates--a validated pressurized liquid extraction/liquid chromatography-mass spectrometry protocol for Isatis tinctoria, and qualitative analysis of other cruciferous plants.

PubMed

Mohn, Tobias; Cutting, Brian; Ernst, Beat; Hamburger, Matthias

2007-09-28

Glucosinolates have attracted significant interest due to the chemopreventive properties of some of their transformation products. Numerous protocols for the extraction and analysis of glucosinolates have been published, but limited effort has been devoted to optimize and validate crucial extraction parameters and sample preparation steps. We carried out a systematic optimization and validation of a quantitative assay for the direct analysis of intact glucosinolates in Isatis tinctoria leaves (woad, Brassicaceae). Various parameters such as solvent composition, particle size, temperature, and number of required extraction steps were optimized using pressurized liquid extraction (PLE). We observed thermal degradation of glucosinolates at temperatures above 50 degrees C, and loss of >60% within 10min at 100 degrees C, but no enzymatic degradation in the leaf samples at ambient temperature. Excellent peak shape and resolution was obtained by reversed-phase chromatography on a Phenomenex Aqua column using 10mM ammonium formate as ion-pair reagent. Detection was carried out by electrospray ionisation mass spectrometry in the negative ion mode. Analysis of cruciferous vegetables and spices such as broccoli (Brassica oleracea L. var. italica), garden cress (Lepidium sativum L.) and black mustard (Sinapis nigra L.) demonstrated the general applicability of the method.

Optimization of Alkaline Extraction and Bioactivities of Polysaccharides from Rhizome of Polygonatum odoratum

PubMed Central

Chen, Yong; Yin, Luoyi; Zhang, Xuejiao; Wang, Yan; Chen, Qiuzhi; Jin, Chenzhong; Wang, Jihua

2014-01-01

The present study is to explore the optimal extraction parameters, antioxidant activity, and antimicrobial activity of alkaline soluble polysaccharides from rhizome of Polygonatum odoratum. The optimal extraction parameters were determined as the following: NaOH concentration (A) 0.3 M, temperature (B) 80°C, ratio of NaOH to solid (C) 10-fold, and extraction time (D) 4 h, in which ratio of NaOH to solid was a key factor. The order of the factors was ratio of NaOH to solid (fold, C) > extraction temperature (°C, B) > NaOH concentration (M, A) > extraction time (h, D). The monosaccharide compositions of polysaccharides from P. odoratum were rhamnose, mannose, xylose, and arabinose with the molecular ratio of 31.78, 31.89, 11.11, and 1.00, respectively. The reducing power, the 1, 1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging rate, the hydroxyl radicals scavenging rate, and the inhibition rate to polyunsaturated fatty acid (PUFA) peroxidation of the alkaline soluble polysaccharides from P. odoratum at 1 mg/mL were 9.81%, 52.84%, 19.22%, and 19.42% of ascorbic acid at the same concentration, respectively. They also showed antimicrobial activity against pathogenic bacteria Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, and Escherichia coli. PMID:25093173

Application of Box-Behnken design for ultrasonic-assisted extraction of polysaccharides from Paeonia emodi.

PubMed

Ahmad, Ajaz; Alkharfy, Khalid M; Wani, Tanveer A; Raish, Mohammad

2015-01-01

The objective of the present work was to study the ultrasonic assisted extraction and optimization of polysaccharides from Paeonia emodi and evaluation of its anti-inflammatory response. Specifically, the optimization of polysaccharides was carried out using Box-Behnken statistical experimental design. Response surface methodology (RSM) of three factors (extraction temperature, extraction time and liquid solid ratio) was employed to optimize the percentage yield of the polysaccharides. The experimental data were fitted to quadratic response surface models using multiple regression analysis with high coefficient of determination value (R) of 0.9906. The highest polysaccharide yield (8.69%) as per the Derringer's desirability prediction tool was obtained under the optimal extraction condition (extraction temperature 47.03 °C, extraction time 15.68 min, and liquid solid ratio 1.29 ml/g) with a desirability value of 0.98. These optimized values of tested parameters were validated under similar conditions (n = 6), an average of 8.13 ± 2.08% of polysaccharide yield was obtained in an optimized extraction conditions with 93.55% validity. The anti-inflammatory effect of polysaccharides of P. emodi were studied on carrageenan induced paw edema. In vivo results showed that the P. emodi 200mg/kg of polysaccharide extract exhibited strong potential against inflammatory response induced by 1% suspension of carrageenean in normal saline. Copyright © 2014 Elsevier B.V. All rights reserved.

Meltlets(®) of soy isoflavones: process optimization and the effect of extrusion spheronization process parameters on antioxidant activity.

PubMed

Deshmukh, Ketkee; Amin, Purnima

2013-07-01

In the current research work an attempt was made to develop "Melt in mouth pellets" (Meltlets(®)) containing 40% herbal extract of soy isoflavones that served to provide antioxidants activity in menopausal women. The process of extrusion-spheronization was optimized for extruder speed, extruder screen size, spheronization speed, and time. While doing so the herbal extract incorporated in the pellet matrix was subjected to various processing conditions such as the effect of the presence of other excipients, mixing or kneading to prepare wet mass, heat generated during the process of extrusion, spheronization, and drying. Thus, the work further investigates the effect of these processing parameters on the antioxidant activity of the soy isoflavone herbal extract incorporated in the formula. Thereby, the antioxidant activity of the soya bean herbal extract, Meltlets(®) and of the placebo pellets was evaluated using DPPH free radical scavenging assay and total reduction capacity.

Optimization of ultrasound assisted extraction of bioactive components from brown seaweed Ascophyllum nodosum using response surface methodology.

PubMed

Kadam, Shekhar U; Tiwari, Brijesh K; Smyth, Thomas J; O'Donnell, Colm P

2015-03-01

The objective of this study was to investigate the effect of key extraction parameters of extraction time (5-25 min), acid concentration (0-0.06 M HCl) and ultrasound amplitude (22.8-114 μm) on yields of bioactive compounds (total phenolics, fucose and uronic acid) from Ascophyllumnodosum. Response surface methodology was employed to optimize the extraction variables for bioactive compounds' yield. A second order polynomial model was fitted well to the extraction experimental data with (R(2)>0.79). Extraction yields of 143.12 mgGAE/gdb, 87.06 mg/gdb and 128.54 mg/gdb were obtained for total phenolics, fucose and uronic acid respectively at optimized extraction conditions of extraction time (25 min), acid concentration (0.03 M HCl) and ultrasonic amplitude (114 μm). Mass spectroscopy analysis of extracts show that ultrasound enhances the extraction of high molecular weight phenolic compounds from A. nodosum. This study demonstrates that ultrasound assisted extraction (UAE) can be employed to enhance extraction of bioactive compounds from seaweed. Copyright © 2014 Elsevier B.V. All rights reserved.

Optimization and adsorption kinetic studies of aqueous manganese ion removal using chitin extracted from shells of edible Philippine crabs

NASA Astrophysics Data System (ADS)

Quimque, Mark Tristan J.; Jimenez, Marvin C.; Acas, Meg Ina S.; Indoc, Danrelle Keth L.; Gomez, Enjelyn C.; Tabuñag, Jenny Syl D.

2017-01-01

Manganese is a common contaminant in drinking water along with other metal pollutants. This paper investigates the use of chitin, extracted from crab shells obtained as restaurant throwaway, as an adsorbent in removing manganese ions from aqueous medium. In particular, this aims to optimize the adsorption parameters and look into the kinetics of the process. The adsorption experiments done in this study employed the batch equilibration method. In the optimization, the following parameters were considered: pH and concentration of Mn (II) sorbate solution, particle size and dosage of adsorbent chitin, and adsorbent-adsorbate contact time. At the optimal condition, the order of the adsorption reaction was estimated using kinetic models which describes the process best. It was found out that the adsorption of aqueous Mn (II) ions onto chitin obeys the pseudo-second order model. This model assumes that the adsorption occurred via chemisorption

Ultrasound assisted extraction of polysaccharides from Lentinus edodes and its anti-hepatitis B activity in vitro.

PubMed

Zhao, Yong-Ming; Yang, Jian-Ming; Liu, Ying-Hui; Zhao, Ming; Wang, Jin

2018-02-01

The aim of this study was to optimize the extraction process of polysaccharides from the fruiting bodies of Lentinus edodes and investigate its anti-hepatitis B virus activity. The extracting parameters including ultrasonic power (240-320W), extraction temperature (40-60°C) and extraction time (15-25min) was optimized by using three-variable-three-level Box-Behnken design based on the single-factor experiments. Data analysis results showed that the optimal conditions for extracting LEPs were an extraction temperature of 45°C, extraction time of 21min and ultrasonic power of 290W. Under these optimal conditions, the experimental yield of LEPs was 9.75%, a 1.62-fold increase compared with conventional heat water extraction (HWE). In addition, crude polysaccharides were purified to obtain two fractions (LEP-1 and LEP-2). Chemical analysis showed that these components were rich in glucose, arabinose and mannose. Furthermore, HepG2.2.15 cells were used as in vitro models to evaluate their anti-hepatitis B virus (HBV) activity. The results suggest that LEPs possesses potent anti-HBV activity in vitro. Copyright © 2017 Elsevier B.V. All rights reserved.

Optimization of microwave-assisted extraction of polyphenols from Myrtus communis L. leaves.

PubMed

Dahmoune, Farid; Nayak, Balunkeswar; Moussi, Kamal; Remini, Hocine; Madani, Khodir

2015-01-01

Phytochemicals, such as phenolic compounds, are of great interest due to their health-benefitting antioxidant properties and possible protection against inflammation, cardiovascular diseases and certain types of cancer. Maximum retention of these phytochemicals during extraction requires optimised process parameter conditions. A microwave-assisted extraction (MAE) method was investigated for extraction of total phenolics from Myrtus communis leaves. The total phenolic capacity (TPC) of leaf extracts at optimised MAE conditions was compared with ultrasound-assisted extraction (UAE) and conventional solvent extraction (CSE). The influence of extraction parameters including ethanol concentration, microwave power, irradiation time and solvent-to-solid ratio on the extraction of TPC was modeled by using a second-order regression equation. The optimal MAE conditions were 42% ethanol concentration, 500 W microwave power, 62 s irradiation time and 32 mL/g solvent to material ratio. Ethanol concentration and liquid-to-solid ratio were the significant parameters for the extraction process (p<0.01). Under the MAE optimised conditions, the recovery of TPC was 162.49 ± 16.95 mg gallic acidequivalent/gdry weight(DW), approximating the predicted content (166.13 mg GAE/g DW). When bioactive phytochemicals extracted from Myrtus leaves using MAE compared with UAE and CSE, it was also observed that tannins (32.65 ± 0.01 mg/g), total flavonoids (5.02 ± 0.05 mg QE/g) and antioxidant activities (38.20 ± 1.08 μg GAE/mL) in MAE extracts were higher than the other two extracts. These findings further illustrate that extraction of bioactive phytochemicals from plant materials using MAE method consumes less extraction solvent and saves time. Copyright © 2014 Elsevier Ltd. All rights reserved.

Micromagnetic measurement for characterization of ferromagnetic materials' microstructural properties

NASA Astrophysics Data System (ADS)

Zhang, Shuo; Shi, Xiaodong; Udpa, Lalita; Deng, Yiming

2018-05-01

Magnetic Barkhausen noise (MBN) is measured in low carbon steels and the relationship between carbon content and parameter extracted from MBN signal has been investigated. The parameter is extracted experimentally by fitting the original profiles with two Gaussian curves. The gap between two peaks (ΔG) of fitted Gaussian curves shows a better linear relationship with carbon contents of samples in the experiment. The result has been validated with simulation by Monte Carlo method. To ensure the sensitivity of measurement, advanced multi-objective optimization algorithm Non-dominant sorting genetic algorithm III (NSGA III) has been used to fulfill the optimization of the magnetic core of sensor.

Optimization of microwave-assisted extraction of analgesic and anti-inflammatory drugs from human plasma and urine using response surface experimental designs.

PubMed

Fernández, Purificación; Fernández, Ana M; Bermejo, Ana M; Lorenzo, Rosa A; Carro, Antonia M

2013-04-01

The performance of microwave-assisted extraction and HPLC with photodiode array detection method for determination of six analgesic and anti-inflammatory drugs from plasma and urine, is described, optimized, and validated. Several parameters affecting the extraction technique were optimized using experimental designs. A four-factor (temperature, phosphate buffer pH 4.0 volume, extraction solvent volume, and time) hybrid experimental design was used for extraction optimization in plasma, and three-factor (temperature, extraction solvent volume, and time) Doehlert design was chosen to extraction optimization in urine. The use of desirability functions revealed the optimal extraction conditions as follows: 67°C, 4 mL phosphate buffer pH 4.0, 12 mL of ethyl acetate and 9 min, for plasma and the same volume of buffer and ethyl acetate, 115°C and 4 min for urine. Limits of detection ranged from 4 to 45 ng/mL in plasma and from 8 to 85 ng/mL in urine. The reproducibility evaluated at two concentration levels was less than 6.5% for both specimens. The recoveries were from 89 to 99% for plasma and from 83 to 99% for urine. The proposed method was successfully applied in plasma and urine samples obtained from analgesic users. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimized Extraction, Preliminary Characterization, and In Vitro Antioxidant Activity of Polysaccharides from Glycyrrhiza Uralensis Fisch

PubMed Central

Chen, Jie; Li, Wan-chen; Gu, Xin-li

2017-01-01

Background This study performed optimized extraction, preliminary characterization, and in vitro antioxidant activities of polysaccharides from Glycyrrhiza uralensis Fisch. Material/Methods Three parameters (extraction temperature, ratio of water to raw material, and extraction time) were optimized for yields of G. uralensis polysaccharides (GUP) using response surface methodology with Box-Behnken design (BBD). The GUP was purified using DEAE cellulose 32-column chromatography. The main fraction obtained from G. uralensis Fisch was GUP-II, which was composed of rhamnose, arabinose, galactose, and glucose monosaccharide, was screened for antioxidant properties using DP Hand hydroxyl radical scavenging assays. In addition, immunological activity of GUP-II was determined by nitric oxide and lymphocyte proliferation assays. Results Optimization revealed maximum GUP yields with an extraction temperature of 99°C, water: raw material ratio of 15: 1, and extraction duration of 2 h. GUP-II purified from G. uralensis Fisch had good in vitro DPPH and hydroxyl radical scavenging abilities. Immunologically, GUP-II significantly stimulated NO production in RAW 264.7 macrophages, and significantly enhanced LPS-induced lymphocyte proliferation. Conclusions Extraction of GUP from G. uralensis Fisch can be optimized with respect to temperature, extraction period, and ratio of water to material, using response surface methodology. The purified product (GUP-II) possesses excellent antioxidant and immunological activities. PMID:28404983

Novel Approaches to Extraction Methods in Recovery of Capsaicin from Habanero Pepper (CNPH 15.192).

PubMed

Martins, Frederico S; Borges, Leonardo L; Ribeiro, Claudia S C; Reifschneider, Francisco J B; Conceição, Edemilson C

2017-07-01

The objective of this study was to compare three capsaicin extraction methods: Shoxlet, Ultrasound-assisted Extraction (UAE), and Shaker-assisted Extraction (SAE) from Habanero pepper, CNPH 15.192. The different parameters evaluated were alcohol degree, time extraction, and solid-solvent ratio using response surface methodology (RSM). The three parameters found significant ( p < 0.05) were for UAE and solvent concentration and extraction time for SAE. The optimum conditions for the capsaicin UAE and SAE were similar 95% alcohol degree, 30 minutes and solid-liquid ratio 2 mg/mL. The Soxhlet increased the extraction in 10-25%; however, long extraction times (45 minutes) degraded 2% capsaicin. The extraction of capsaicin was influenced by extraction method and by the operating conditions chosen. The optimized conditions provided savings of time, solvent, and herbal material. Prudent choice of the extraction method is essential to ensure optimal yield of extract, thereby making the study relevant and the knowledge gained useful for further exploitation and application of this resource. Habanero pepper , line CNPH 15.192, possess capsaicin in higher levels when compared with others speciesHigher levels of ethanolic strength are more suitable to obtain a higher levels of capsaicinBox-Behnken design indicates to be useful to explore the best conditions of ultrasound assisted extraction of capsaicin. Abbreviations used: Nomenclature UAE: Ultrasound-assisted Extraction; SAE: Shaker-assisted Extraction.

Optimization of an accelerated solvent extraction dispersive liquid-liquid microextraction method for the separation and determination of essential oil from Ligusticum chuanxiong Hort by gas chromatography with mass spectrometry.

PubMed

Yang, Guang; Sun, Qiushi; Hu, Zhiyan; Liu, Hua; Zhou, Tingting; Fan, Guorong

2015-10-01

In this study, an accelerated solvent extraction dispersive liquid-liquid microextraction coupled with gas chromatography and mass spectrometry was established and employed for the extraction, concentration and analysis of essential oil constituents from Ligusticum chuanxiong Hort. Response surface methodology was performed to optimize the key parameters in accelerated solvent extraction on the extraction efficiency, and key parameters in dispersive liquid-liquid microextraction were discussed as well. Two representative constituents in Ligusticum chuanxiong Hort, (Z)-ligustilide and n-butylphthalide, were quantitatively analyzed. It was shown that the qualitative result of the accelerated solvent extraction dispersive liquid-liquid microextraction approach was in good agreement with that of hydro-distillation, whereas the proposed approach took far less extraction time (30 min), consumed less plant material (usually <1 g, 0.01 g for this study) and solvent (<20 mL) than the conventional system. To sum up, the proposed method could be recommended as a new approach in the extraction and analysis of essential oil. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Studies on optimizing preparation technics of wumeitougu oral liquid by response surface methodology].

PubMed

Yu, Xiao-cui; Liu, Gao-feng; Wang, Xin

2011-02-01

To optimize the preparation technics of wumeitougu oral liquid (WTOL) by response surface methodology. Based on the single-factor tests, the times of WTOL extraction, alcohol precipitation concentration and pH value were selected as three factors for box-behnken central composite design. The response surface methodology was used to optimize the parameters of the preparation. Under the condition of extraction time 1.5 h, extraction times 2.772, the relative density 1.12, alcohol precipitation concentration 68.704%, and pH value 5.0, he theory highest content of Asperosaponin VI was up to 549.908 mg/L. Considering the actual situation, the conditions were amended to three extract times, alcohol precipitation concentration 69%, pH value 5.0, and the content of Dipsacaceae VI saponin examined was 548.63 mg/L which was closed to the theoretical value. The optimized preparation technics of WTOL by response surface methodology is reasonable and feasible.

Extraction of bioactives from Orthosiphon stamineus using microwave and ultrasound-assisted techniques: Process optimization and scale up.

PubMed

Chan, Chung-Hung; See, Tiam-You; Yusoff, Rozita; Ngoh, Gek-Cheng; Kow, Kien-Woh

2017-04-15

This work demonstrated the optimization and scale up of microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE) of bioactive compounds from Orthosiphon stamineus using energy-based parameters such as absorbed power density and absorbed energy density (APD-AED) and response surface methodology (RSM). The intensive optimum conditions of MAE obtained at 80% EtOH, 50mL/g, APD of 0.35W/mL, AED of 250J/mL can be used to determine the optimum conditions of the scale-dependent parameters i.e. microwave power and treatment time at various extraction scales (100-300mL solvent loading). The yields of the up scaled conditions were consistent with less than 8% discrepancy and they were about 91-98% of the Soxhlet extraction yield. By adapting APD-AED method in the case of UAE, the intensive optimum conditions of the extraction, i.e. 70% EtOH, 30mL/g, APD of 0.22W/mL, AED of 450J/mL are able to achieve similar scale up results. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimizing conditions for the extraction of pigments in cochineals (Dactylopius coccus Costa) using response surface methodology.

PubMed

González, Mónica; Méndez, Jesús; Carnero, Aurelio; Lobo, M Gloria; Afonso, Ana

2002-11-20

A simple method was developed for the extraction and determination of color pigments in cochineals (Dactylopius coccus Costa). The procedure was based on the solvent extraction of pigments in insect samples using methanol:water (65:35, v:v) as extractant. Two-level factorial design was used in order to optimize the solvent extraction parameters: temperature, time, methanol concentration in the extractant mixture, and the number of extractions. The results suggest that the number of extractions is statistically the most significant factor. The separation and determination of the pigments was carried out by high-performance liquid chromatography with UV-visible detection. Because the absorption spectra of different pigments are different in the visible region, it is convenient to use a diode array detector to obtain chromatographic profiles that allow for the characterization of the extracted pigments.

Microwave-Assisted Extraction of Oleanolic Acid and Ursolic Acid from Ligustrum lucidum Ait

PubMed Central

Xia, En-Qin; Wang, Bo-Wei; Xu, Xiang-Rong; Zhu, Li; Song, Yang; Li, Hua-Bin

2011-01-01

Oleanolic acid and ursolic acid are the main active components in fruit of Ligustrum lucidum Ait, and possess anticancer, antimutagenic, anti-inflammatory, antioxidative and antiprotozoal activities. In this study, microwave-assisted extraction of oleanolic acid and ursolic acid from Ligustrum lucidum was investigated with HPLC-photodiode array detection. Effects of several experimental parameters, such as type and concentration of extraction solvent, ratio of liquid to material, microwave power, extraction temperature and microwave time, on the extraction efficiencies of oleanolic acid and ursolic acid from Ligustrum lucidum were evaluated. The influence of experimental parameters on the extraction efficiency of ursolic acid was more significant than that of oleanolic acid (p < 0.05). The optimal extraction conditions were 80% ethanol aqueous solution, the ratio of material to liquid was 1:15, and extraction for 30 min at 70 °C under microwave irradiation of 500 W. Under optimal conditions, the yields of oleanolic acid and ursolic acid were 4.4 ± 0.20 mg/g and 5.8 ± 0.15 mg/g, respectively. The results obtained are helpful for the full utilization of Ligustrum lucidum, which also indicated that microwave-assisted extraction is a very useful method for extraction of oleanolic acid and ursolic acid from plant materials. PMID:21954361

Extraction of Oil from Flaxseed (Linum usitatissimum L.) Using Enzyme-Assisted Three-Phase Partitioning.

PubMed

Tan, Zhi-Jian; Yang, Zi-Zhen; Yi, Yong-Jian; Wang, Hong-Ying; Zhou, Wan-Lai; Li, Fen-Fang; Wang, Chao-Yun

2016-08-01

In this study, enzyme-assisted three-phase partitioning (EATPP) was used to extract oil from flaxseed. The whole procedure is composed of two parts: the enzymolysis procedure in which the flaxseed was hydrolyzed using an enzyme solution (the influencing parameters such as the type and concentration of enzyme, temperature, and pH were optimized) and three-phase partitioning (TPP), which was conducted by adding salt and t-butanol to the crude flaxseed slurry, resulting in the extraction of flaxseed oil into alcohol-rich upper phase. The concentration of t-butanol, concentration of salt, and the temperature were optimized to maximize the extraction yield. Under optimized conditions of a 49.29 % t-butanol concentration, 30.43 % ammonium sulfate concentration, and 35 °C extraction temperature, a maximum extraction yield of 71.68 % was obtained. This simple and effective EATPP can be used to achieve high extraction yields and oil quality, and thus, it is potential for large-scale oil production.

[Study on the extraction of the total alkaloids from Caulopyhllum robustum].

PubMed

Li, Yi-ping; Yang, Guang-de; He, Lang-chong

2007-02-01

To study the technological parameters of the extraction process of the total alkaloids from Caulopyhllum robstum. Taspine, whiVh is main component of the total alkaloids from Caulopyhllum robustum, was selected as an evaluating marker and determined by HPLC. The orthogonal test was used to optimize extracting conditions in the process of acid water extraction. Then the optimized conditions for purification using cation exchange resin were investigated. The optimized conditions in the process of acid water extraction were 1% hydrochloric acid as much as seven times of the medicine amount for 24hs and three times. Then the extraction of acid water was purified with a column of macroporous cation exchange resin LSD001 at 2 ml/min of flow rate, then eluted with 10BV of 4% aqueous ammonia ethanol. The extraction ratio of the total alkaloids was 1. 35% and the content of taspine of the total alkaloids was 6. 80%. This technology is simply, cheap effective and feasible for manufacture in great scale.

Statistical optimization of process parameters for inulinase production from Tithonia weed by Arthrobacter mysorens strain no.1.

PubMed

Kamble, Prajakta P; Kore, Maheshkumar V; Patil, Sushama A; Jadhav, Jyoti P; Attar, Yasmin C

2018-06-01

Tithonia rotundifolia is an easily available and abundant inulin rich weed reported to be competitive and allelopathic. This weed inulin is hydrolyzed by inulinase into fructose. Response surface methodology was employed to optimize culture conditions for the inulinase production from Arthrobacter mysorens strain no.1 isolated from rhizospheric area of Tithonia weed. Initially, Plackett- Burman design was used for screening 11 nutritional parameters for inulinase production including inulin containing weeds as cost effective substrate. The experiment shows that amongst the 11 parameters studied, K 2 HPO 4 , Inulin, Agave sisalana extract and Tithonia rotundifolia were the most significant variables for inulinase production. Quantitative effects of these 4 factors were further investigated using Box Behnken design. The medium having 0.27% K 2 HPO 4 , 2.54% Inulin, 6.57% Agave sisalana extract and 7.27% Tithonia rotundifolia extract were found to be optimum for maximum inulinase production. The optimization strategies used showed 2.12 fold increase in inulinase yield (1669.45 EU/ml) compared to non-optimized medium (787 EU/ml). Fructose produced by the action of inulinase was further confirmed by spectrophotometer, osazone, HPTLC and FTIR methods. Thus Tithonia rotundifolia can be used as an eco-friendly, economically feasible and promising alternative substrate for commercial inulinase production yielding fructose from Arthrobacter mysorens strain no.1. Copyright © 2018 Elsevier B.V. All rights reserved.

Optimized ultrasound-assisted extraction procedure for the analysis of opium alkaloids in papaver plants by cyclodextrin-modified capillary electrophoresis.

PubMed

Fakhari, Ali Reza; Nojavan, Saeed; Ebrahimi, Samad Nejad; Evenhuis, Christopher John

2010-07-01

This study investigated the use of ultrasound-assisted extraction to improve the extraction efficiency of morphine, codeine and thebaine from the papaver plants. Extraction conditions such as type of solvent, temperature, duration, frequency and power level of ultrasonic were optimized and the influences of different parameters on resolution of alkaloids in CE were studied. The optimized condition for CE separation includes a sodium phosphate buffer (100 mM, pH 3.0) containing 5 mM alpha-CD. The optimized extraction conditions for ultrasound-assisted extraction was an extraction time of 1 h, an ultrasonic frequency of 60 kHz with water-methanol (80:20) at 40 degrees C as the extraction solvent. The LOD for alkaloids was found to be 0.1 microg/mL at a signal-to-noise ratio of 3:1. The RSDs for peak areas were in the range of 1.4-4.4%. The amounts of opium alkaloids (mg/100 g dried sample) in four Iranian papaver plants were found to be in the range of 7.8-8.7 (morphine), 5.5-9.5 (codeine) and 1.4-10.4 (thebaine). It should be emphasized that no cleanup of the filtered extract was required; hence, direct determination after extraction drastically simplifies the analytical process.

Application of Modified Particle Swarm Optimization Method for Parameter Extraction of 2-D TEC Mapping

NASA Astrophysics Data System (ADS)

Toker, C.; Gokdag, Y. E.; Arikan, F.; Arikan, O.

2012-04-01

Ionosphere is a very important part of Space Weather. Modeling and monitoring of ionospheric variability is a major part of satellite communication, navigation and positioning systems. Total Electron Content (TEC), which is defined as the line integral of the electron density along a ray path, is one of the parameters to investigate the ionospheric variability. Dual-frequency GPS receivers, with their world wide availability and efficiency in TEC estimation, have become a major source of global and regional TEC modeling. When Global Ionospheric Maps (GIM) of International GPS Service (IGS) centers (http://iono.jpl.nasa.gov/gim.html) are investigated, it can be observed that regional ionosphere along the midlatitude regions can be modeled as a constant, linear or a quadratic surface. Globally, especially around the magnetic equator, the TEC surfaces resemble twisted and dispersed single centered or double centered Gaussian functions. Particle Swarm Optimization (PSO) proved itself as a fast converging and an effective optimization tool in various diverse fields. Yet, in order to apply this optimization technique into TEC modeling, the method has to be modified for higher efficiency and accuracy in extraction of geophysical parameters such as model parameters of TEC surfaces. In this study, a modified PSO (mPSO) method is applied to regional and global synthetic TEC surfaces. The synthetic surfaces that represent the trend and small scale variability of various ionospheric states are necessary to compare the performance of mPSO over number of iterations, accuracy in parameter estimation and overall surface reconstruction. The Cramer-Rao bounds for each surface type and model are also investigated and performance of mPSO are tested with respect to these bounds. For global models, the sample points that are used in optimization are obtained using IGS receiver network. For regional TEC models, regional networks such as Turkish National Permanent GPS Network (TNPGN-Active) receiver sites are used. The regional TEC models are grouped into constant (one parameter), linear (two parameters), and quadratic (six parameters) surfaces which are functions of latitude and longitude. Global models require seven parameters for single centered Gaussian and 13 parameters for double centered Gaussian function. The error criterion is the normalized percentage error for both the surface and the parameters. It is observed that mPSO is very successful in parameter extraction of various regional and global models. The normalized reconstruction error varies from 10-4 for constant surfaces to 10-3 for quadratic surfaces in regional models, sampled with regional networks. Even for the cases of a severe geomagnetic storm that affects measurements globally, with IGS network, the reconstruction error is on the order of 10-1 even though individual parameters have higher normalized errors. The modified PSO technique proved itself to be a useful tool for parameter extraction of more complicated TEC models. This study is supported by TUBITAK EEEAG under Grant No: 109E055.

Maca polysaccharides: Extraction optimization, structural features and anti-fatigue activities.

PubMed

Li, Yujuan; Xin, Yizhou; Xu, Fangxue; Zheng, Mengmeng; Xi, Xiaozhi; Cui, Xiaowei; Cao, Hui; Guo, Hong; Han, Chunchao

2018-08-01

The maca polysaccharides optimal extraction conditions were obtained by using response surface methodology (RSM) method and the anti-fatigue activity of maca polysaccharides (MCP) was explored. The maca polysaccharides extract yield of RSM could reach 9.97 mg/g by using the model predicts, and the total sugar and protein purity were 61.00% and 4.46% with the further isolation process, respectively. And the monosaccharide compositions obtained by gas chromatograph (GC) were composed of rhamnose (rha), glucose (glc), galactose (gal) with the ratio of 2.34:10.21:1.00. Furthermore, the anti-fatigue activity was evaluated by the swimming parameter, biochemistry parameters (liver glycogen (LG), blood urea nitrogen (BUN), and lactic acid (LD)), the result indicated that the low-dose maca polysaccharides group had the significant anti-fatigue activity. Copyright © 2018 Elsevier B.V. All rights reserved.

Supercritical Carbon Dioxide Extraction of the Oak Silkworm (Antheraea pernyi) Pupal Oil: Process Optimization and Composition Determination

PubMed Central

Pan, Wen-Juan; Liao, Ai-Mei; Zhang, Jian-Guo; Dong, Zeng; Wei, Zhao-Jun

2012-01-01

Supercritical carbon dioxide (SC-CO2) extraction of oil from oak silkworm pupae was performed in the present research. Response surface methodology (RSM) was applied to optimize the parameters of SC-CO2 extraction, including extraction pressure, temperature, time and CO2 flow rate on the yield of oak silkworm pupal oil (OSPO). The optimal extraction condition for oil yield within the experimental range of the variables researched was at 28.03 MPa, 1.83 h, 35.31 °C and 20.26 L/h as flow rate of CO2. Under this condition, the oil yield was predicted to be 26.18%. The oak silkworm pupal oil contains eight fatty acids, and is rich in unsaturated fatty acids and α-linolenic acid (ALA), accounting for 77.29% and 34.27% in the total oil respectively. PMID:22408458

Optimization of supercritical fluid extraction and HPLC identification of wedelolactone from Wedelia calendulacea by orthogonal array design.

PubMed

Patil, Ajit A; Sachin, Bhusari S; Wakte, Pravin S; Shinde, Devanand B

2014-11-01

The purpose of this work is to provide a complete study of the influence of operational parameters of the supercritical carbon dioxide assisted extraction (SC CO2E) on yield of wedelolactone from Wedelia calendulacea Less., and to find an optimal combination of factors that maximize the wedelolactone yield. In order to determine the optimal combination of the four factors viz. operating pressure, temperature, modifier concentration and extraction time, a Taguchi experimental design approach was used: four variables (three levels) in L9 orthogonal array. Wedelolactone content was determined using validated HPLC methodology. Optimum extraction conditions were found to be as follows: extraction pressure, 25 MPa; temperature, 40 °C; modifier concentration, 10% and extraction time, 90 min. Optimum extraction conditions demonstrated wedelolactone yield of 8.01 ± 0.34 mg/100 g W. calendulacea Less. Pressure, temperature and time showed significant (p < 0.05) effect on the wedelolactone yield. The supercritical carbon dioxide extraction showed higher selectivity than the conventional Soxhlet assisted extraction method.

Optimization of supercritical fluid extraction and HPLC identification of wedelolactone from Wedelia calendulacea by orthogonal array design

PubMed Central

Patil, Ajit A.; Sachin, Bhusari S.; Wakte, Pravin S.; Shinde, Devanand B.

2013-01-01

The purpose of this work is to provide a complete study of the influence of operational parameters of the supercritical carbon dioxide assisted extraction (SC CO2E) on yield of wedelolactone from Wedelia calendulacea Less., and to find an optimal combination of factors that maximize the wedelolactone yield. In order to determine the optimal combination of the four factors viz. operating pressure, temperature, modifier concentration and extraction time, a Taguchi experimental design approach was used: four variables (three levels) in L9 orthogonal array. Wedelolactone content was determined using validated HPLC methodology. Optimum extraction conditions were found to be as follows: extraction pressure, 25 MPa; temperature, 40 °C; modifier concentration, 10% and extraction time, 90 min. Optimum extraction conditions demonstrated wedelolactone yield of 8.01 ± 0.34 mg/100 g W. calendulacea Less. Pressure, temperature and time showed significant (p < 0.05) effect on the wedelolactone yield. The supercritical carbon dioxide extraction showed higher selectivity than the conventional Soxhlet assisted extraction method. PMID:25687584

Optimization of Process Parameters and Kinetic Model of Enzymatic Extraction of Polyphenols from Lonicerae Flos

PubMed Central

Kong, Fansheng; Yu, Shujuan; Bi, Yongguang; Huang, Xiaojun; Huang, Mengqian

2016-01-01

Objective: To optimize and verify the cellulase extraction of polyphenols from honeysuckle and provide a reference for enzymatic extracting polyphenols from honeysuckle. Materials and Methods: The uniform design was used According to Fick's first law and kinetic model, fitting analysis of the dynamic process of enzymatic extracting polyphenols was conducted. Results: The optimum enzymatic extraction parameters for polyphenols from honeysuckle are found to be 80% (v/v) of alcohol, 35:1 (mL/g) of liquid-solid ratio, 80°C of extraction temperature, 8.5 of pH, 6.0 mg of enzyme levels, and 130 min of extraction time. Under the optimal conditions, the extraction rate of polyphenols was 3.03%. The kinetic experiments indicated kinetic equation had a good linear relationship with t even under the conditions of different levels of enzyme and temperature, which means fitting curve tallies well with the experimental values. Conclusion: The results of quantification showed that the results provide a reference for enzymatic extracting polyphenols from honeysuckle. SUMMARY Lonicerae flos (Lonicera japonica Thunb.) is a material of traditional Chinese medicine and healthy drinks, of which active compounds mainly is polyphenols. At present, plant polyphenols are the hotspots centents of food, cosmetic and medicine, because it has strong bioactivity. Several traditional methods are available for the extraction of plant polyphenols including impregnation, solvent extraction, ultrasonic extraction, hot-water extraction, alkaline dilute alcohol or alkaline water extraction, microwave extraction and Supercritical CO2 extraction. But now, an increasing number of research on using cellulase to extract active ingredients from plants. Enzymatic method is widely used for enzyme have excellent properties of high reaction efficiency and specificity, moderate reaction conditions, shorter extraction time and easier to control, less damage to the active ingredient. At present, the enzymatic extraction of polyphenols from honeysuckle and dynamic had not been reported. In this study, using cellulase to extract polyphenols from honeysuckle is first applied. Moreover, uniform design was used to optimize process and kinetic model of extraction was established to analyze the characteristics of enzymatic extraction, in order to improve the yield of polyphenols from honeysuckle and make maximum use of Lonicerae flos, which provide references for industrial production. PMID:27018039

Synthesis and antimicrobial activity of palladium nanoparticles from Prunus × yedoensis leaf extract

USDA-ARS?s Scientific Manuscript database

The eco-friendly production of palladium nanoparticles (PdNPs) by Prunus × yedoensis tree leaf extract was studied for the first time. Initial confirmation of PdNP production was confirmed by a color change from light yellow to dark brown. The optimization parameters show that pH 7, 8% leaf extract,...

Determination of the clean-up efficiency of the solid-phase extraction of rosemary extracts: Application of full-factorial design in hyphenation with Gaussian peak fit function.

PubMed

Meischl, Florian; Kirchler, Christian Günter; Jäger, Michael Andreas; Huck, Christian Wolfgang; Rainer, Matthias

2018-02-01

We present a novel method for the quantitative determination of the clean-up efficiency to provide a calculated parameter for peak purity through iterative fitting in conjunction with design of experiments. Rosemary extracts were used and analyzed before and after solid-phase extraction using a self-fabricated mixed-mode sorbent based on poly(N-vinylimidazole/ethylene glycol dimethacrylate). Optimization was performed by variation of washing steps using a full three-level factorial design and response surface methodology. Separation efficiency of rosmarinic acid from interfering compounds was calculated using an iterative fit of Gaussian-like signals and quantifications were performed by the separate integration of the two interfering peak areas. Results and recoveries were analyzed using Design-Expert® software and revealed significant differences between the washing steps. Optimized parameters were considered and used for all further experiments. Furthermore, the solid-phase extraction procedure was tested and compared with commercial available sorbents. In contrast to generic protocols of the manufacturers, the optimized procedure showed excellent recoveries and clean-up rates for the polymer with ion exchange properties. Finally, rosemary extracts from different manufacturing areas and application types were studied to verify the developed method for its applicability. The cleaned-up extracts were analyzed by liquid chromatography with tandem mass spectrometry for detailed compound evaluation to exclude any interference from coeluting molecules. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimization of ultrasonic-assisted extraction of total saponins from Eclipta prostrasta L. using response surface methodology.

PubMed

Hu, Ting; Guo, Yan-Yun; Zhou, Qin-Fan; Zhong, Xian-Ke; Zhu, Liang; Piao, Jin-Hua; Chen, Jian; Jiang, Jian-Guo

2012-09-01

Eclipta prostrasta L. is a traditional Chinese medicine herb, which is rich in saponins and has strong antiviral and antitumor activities. An ultrasonic-assisted extraction (UAE) technique was developed for the fast extraction of saponins from E. prostrasta. The content of total saponins in E. prostrasta was determined using UV/vis spectrophotometric methods. Several influential parameters like ethanol concentration, extraction time, temperature, and liquid/solid ratio were investigated for the optimization of the extraction using single factor and Box-Behnken experimental designs. Extraction conditions were optimized for maximum yield of total saponins in E. prostrasta using response surface methodology (RSM) with 4 independent variables at 3 levels of each variable. Results showed that the optimization conditions for saponins extraction were: ethanol concentration 70%, extraction time 3 h, temperature 70 °C, and liquid/solid ratio 14:1. Corresponding saponins content was 2.096%. The mathematical model developed was found to fit well with the experimental data. Practical Application: Although there are wider applications of Eclipta prostrasta L. as a functional food or traditional medicine due to its various bioactivities, these properties are limited by its crude extracts. Total saponins are the main active ingredient of E. prostrasta. This research has optimized the extraction conditions of total saponins from E. prostrasta, which will provide useful reference information for further studies, and offer related industries with helpful guidance in practice. © 2012 Institute of Food Technologists®

Ultrasound-Assisted Extraction of Carnosic Acid and Rosmarinic Acid Using Ionic Liquid Solution from Rosmarinus officinalis

PubMed Central

Zu, Ge; Zhang, Rongrui; Yang, Lei; Ma, Chunhui; Zu, Yuangang; Wang, Wenjie; Zhao, Chunjian

2012-01-01

Ionic liquid based, ultrasound-assisted extraction was successfully applied to the extraction of phenolcarboxylic acids, carnosic acid and rosmarinic acid, from Rosmarinus officinalis. Eight ionic liquids, with different cations and anions, were investigated in this work and [C8mim]Br was selected as the optimal solvent. Ultrasound extraction parameters, including soaking time, solid–liquid ratio, ultrasound power and time, and the number of extraction cycles, were discussed by single factor experiments and the main influence factors were optimized by response surface methodology. The proposed approach was demonstrated as having higher efficiency, shorter extraction time and as a new alternative for the extraction of carnosic acid and rosmarinic acid from R. officinalis compared with traditional reference extraction methods. Ionic liquids are considered to be green solvents, in the ultrasound-assisted extraction of key chemicals from medicinal plants, and show great potential. PMID:23109836

Non-stationary component extraction in noisy multicomponent signal using polynomial chirping Fourier transform.

PubMed

Lu, Wenlong; Xie, Junwei; Wang, Heming; Sheng, Chuan

2016-01-01

Inspired by track-before-detection technology in radar, a novel time-frequency transform, namely polynomial chirping Fourier transform (PCFT), is exploited to extract components from noisy multicomponent signal. The PCFT combines advantages of Fourier transform and polynomial chirplet transform to accumulate component energy along a polynomial chirping curve in the time-frequency plane. The particle swarm optimization algorithm is employed to search optimal polynomial parameters with which the PCFT will achieve a most concentrated energy ridge in the time-frequency plane for the target component. The component can be well separated in the polynomial chirping Fourier domain with a narrow-band filter and then reconstructed by inverse PCFT. Furthermore, an iterative procedure, involving parameter estimation, PCFT, filtering and recovery, is introduced to extract components from a noisy multicomponent signal successively. The Simulations and experiments show that the proposed method has better performance in component extraction from noisy multicomponent signal as well as provides more time-frequency details about the analyzed signal than conventional methods.

[Application of ultrasound counter currentextraction in patent of traditional Chinese medicine].

PubMed

Miao, Yan-ni; Wu, Bin; Yue, Xue-lian

2015-07-01

The patent information of ultrasound countercurrent extraction used in traditional Chinese medicine was analyzed in this paper by the samples from Derwent World Patent Database (DWPI) and the Chinese Patent Abstracts Database (CNABS). The application of ultrasound countercurrent was discussed with the patent applicant,the amount of the annual distribution, and the pharmaceutical raw materials and other aspects. While the technical parameters published in the patent was deeply analyzed, such as material crushing, extraction solvent, extraction time and temperature, extraction equipment and ultrasonic frequency. Thought above research, various technical parameters of ultrasound countercurrent extraction used in traditional Chinese was summarize. The analysis conclusion of the paper can be used in discovering the technical advantages, optimizing extraction conditions, and providing a reference to extraction technological innovation of traditional Chinese medicine.

Batch and Continuous Ultrasound Assisted Extraction of Boldo Leaves (Peumus boldus Mol.).

PubMed

Petigny, Loïc; Périno-Issartier, Sandrine; Wajsman, Joël; Chemat, Farid

2013-03-12

Vegetal extracts are widely used as primary ingredients for various products from creams to perfumes in the pharmaceutical, nutraceutic and cosmetic industries. Having concentrated and active extract is essential, as the process must extract as much soluble material as possible in a minimum time, using the least possible volume of solvent. The boldo leaves extract is of great interest for the industry as it holds a great anti-oxidant activity due to high levels of flavonoids and alkaloids such as boldine. Ultrasound Assisted Extraction (UAE) has been used to improve the efficiency of the plant extraction, reducing extraction time, increasing the concentration of the extract with the same amount of solvent and plant material. After a preliminary study, a response surface method has been used to optimize the extraction of soluble material from the plant. The results provided by the statistical analysis revealed that the optimized conditions were: sonication power 23 W/cm2 for 40 min and a temperature of 36 °C. The optimized parameters of the UAE provide a better extraction compared to a conventional maceration in terms of process time (30 min instead of 120 min), higher yield, more energy saving, cleanliness, safety and product quality.

Batch and Continuous Ultrasound Assisted Extraction of Boldo Leaves (Peumus boldus Mol.)

PubMed Central

Petigny, Loïc; Périno-Issartier, Sandrine; Wajsman, Joël; Chemat, Farid

2013-01-01

Vegetal extracts are widely used as primary ingredients for various products from creams to perfumes in the pharmaceutical, nutraceutic and cosmetic industries. Having concentrated and active extract is essential, as the process must extract as much soluble material as possible in a minimum time, using the least possible volume of solvent. The boldo leaves extract is of great interest for the industry as it holds a great anti-oxidant activity due to high levels of flavonoids and alkaloids such as boldine. Ultrasound Assisted Extraction (UAE) has been used to improve the efficiency of the plant extraction, reducing extraction time, increasing the concentration of the extract with the same amount of solvent and plant material. After a preliminary study, a response surface method has been used to optimize the extraction of soluble material from the plant. The results provided by the statistical analysis revealed that the optimized conditions were: sonication power 23 W/cm2 for 40 min and a temperature of 36 °C. The optimized parameters of the UAE provide a better extraction compared to a conventional maceration in terms of process time (30 min instead of 120 min), higher yield, more energy saving, cleanliness, safety and product quality. PMID:23481637

Novel Approaches to Extraction Methods in Recovery of Capsaicin from Habanero Pepper (CNPH 15.192)

PubMed Central

Martins, Frederico S.; Borges, Leonardo L.; Ribeiro, Claudia S. C.; Reifschneider, Francisco J. B.; Conceição, Edemilson C.

2017-01-01

Introduction: The objective of this study was to compare three capsaicin extraction methods: Shoxlet, Ultrasound-assisted Extraction (UAE), and Shaker-assisted Extraction (SAE) from Habanero pepper, CNPH 15.192. Materials and Methods: The different parameters evaluated were alcohol degree, time extraction, and solid–solvent ratio using response surface methodology (RSM). Results: The three parameters found significant (p < 0.05) were for UAE and solvent concentration and extraction time for SAE. The optimum conditions for the capsaicin UAE and SAE were similar 95% alcohol degree, 30 minutes and solid–liquid ratio 2 mg/mL. The Soxhlet increased the extraction in 10–25%; however, long extraction times (45 minutes) degraded 2% capsaicin. Conclusion: The extraction of capsaicin was influenced by extraction method and by the operating conditions chosen. The optimized conditions provided savings of time, solvent, and herbal material. Prudent choice of the extraction method is essential to ensure optimal yield of extract, thereby making the study relevant and the knowledge gained useful for further exploitation and application of this resource. SUMMARY Habanero pepper, line CNPH 15.192, possess capsaicin in higher levels when compared with others speciesHigher levels of ethanolic strength are more suitable to obtain a higher levels of capsaicinBox-Behnken design indicates to be useful to explore the best conditions of ultrasound assisted extraction of capsaicin. Abbreviations used: Nomenclature UAE: Ultrasound-assisted Extraction; SAE: Shaker-assisted Extraction. PMID:28808409

Optimization of brain PET imaging for a multicentre trial: the French CATI experience.

PubMed

Habert, Marie-Odile; Marie, Sullivan; Bertin, Hugo; Reynal, Moana; Martini, Jean-Baptiste; Diallo, Mamadou; Kas, Aurélie; Trébossen, Régine

2016-12-01

CATI is a French initiative launched in 2010 to handle the neuroimaging of a large cohort of subjects recruited for an Alzheimer's research program called MEMENTO. This paper presents our test protocol and results obtained for the 22 PET centres (overall 13 different scanners) involved in the MEMENTO cohort. We determined acquisition parameters using phantom experiments prior to patient studies, with the aim of optimizing PET quantitative values to the highest possible per site, while reducing, if possible, variability across centres. Jaszczak's and 3D-Hoffman's phantom measurements were used to assess image spatial resolution (ISR), recovery coefficients (RC) in hot and cold spheres, and signal-to-noise ratio (SNR). For each centre, the optimal reconstruction parameters were chosen as those maximizing ISR and RC without a noticeable decrease in SNR. Point-spread-function (PSF) modelling reconstructions were discarded. The three figures of merit extracted from the images reconstructed with optimized parameters and routine schemes were compared, as were volumes of interest ratios extracted from Hoffman acquisitions. The net effect of the 3D-OSEM reconstruction parameter optimization was investigated on a subset of 18 scanners without PSF modelling reconstruction. Compared to the routine parameters of the 22 PET centres, average RC in the two smallest hot and cold spheres and average ISR remained stable or were improved with the optimized reconstruction, at the expense of slight SNR degradation, while the dispersion of values was reduced. For the subset of scanners without PSF modelling, the mean RC of the smallest hot sphere obtained with the optimized reconstruction was significantly higher than with routine reconstruction. The putamen and caudate-to-white matter ratios measured on 3D-Hoffman acquisitions of all centres were also significantly improved by the optimization, while the variance was reduced. This study provides guidelines for optimizing quantitative results for multicentric PET neuroimaging trials.

Kinetics of ultrasound-assisted extraction of antioxidant polyphenols from food by-products: Extraction and energy consumption optimization.

PubMed

Pradal, Delphine; Vauchel, Peggy; Decossin, Stéphane; Dhulster, Pascal; Dimitrov, Krasimir

2016-09-01

Ultrasound-assisted extraction (UAE) of antioxidant polyphenols from chicory grounds was studied in order to propose a suitable valorization of this food industry by-product. The main parameters influencing the extraction process were identified. A new mathematical model for multi-criteria optimization of UAE was proposed. This kinetic model permitted the following and the prediction of the yield of extracted polyphenols, the antioxidant activity of the obtained extracts and the energy consumption during the extraction process in wide ranges of temperature (20-60°C), ethanol content in the solvent (0-60% (vol.) in ethanol-water mixtures) and ultrasound power (0-100W). After experimental validation of the model, several simulations at different technological restrictions were performed to illustrate the potentiality of the model to find the optimal conditions for obtaining a given yield within minimal process duration or with minimal energy consumption. The advantage of ultrasound assistance was clearly demonstrated both for the reduction of extraction duration and for the reduction of energy consumption. Copyright © 2016 Elsevier B.V. All rights reserved.

Inactivation disinfection property of Moringa Oleifera seed extract: optimization and kinetic studies

NASA Astrophysics Data System (ADS)

Idris, M. A.; Jami, M. S.; Hammed, A. M.

2017-05-01

This paper presents the statistical optimization study of disinfection inactivation parameters of defatted Moringa oleifera seed extract on Pseudomonas aeruginosa bacterial cells. Three level factorial design was used to estimate the optimum range and the kinetics of the inactivation process was also carried. The inactivation process involved comparing different disinfection models of Chicks-Watson, Collins-Selleck and Homs models. The results from analysis of variance (ANOVA) of the statistical optimization process revealed that only contact time was significant. The optimum disinfection range of the seed extract was 125 mg/L, 30 minutes and 120rpm agitation. At the optimum dose, the inactivation kinetics followed the Collin-Selleck model with coefficient of determination (R2) of 0.6320. This study is the first of its kind in determining the inactivation kinetics of pseudomonas aeruginosa using the defatted seed extract.

Determination of volatile components of green, black, oolong and white tea by optimized ultrasound-assisted extraction-dispersive liquid-liquid microextraction coupled with gas chromatography.

PubMed

Sereshti, Hassan; Samadi, Soheila; Jalali-Heravi, Mehdi

2013-03-08

Ultrasound assisted extraction (UAE) followed by dispersive liquid-liquid microextraction (DLLME) was used for extraction and preconcentration of volatile constituents of six tea plants. The preconcentrated compounds were analyzed by gas chromatography-mass spectrometry (GC-MS). Totally, 42 compounds were identified and caffeine was quantitatively determined. The main parameters (factors) of the extraction process were optimized by using a central composite design (CCD). Methanol and chloroform were selected as the extraction solvent and preconcentration solvent, respectively .The optimal conditions were obtained as 21 in for sonication time; 32°C for temperature; 27 L for volume of extraction solvent and 7.4% for salt concentration (NaCl/H(2)O). The determination coefficient (R(2)) was 0.9988. The relative standard deviation (RSD %) was 4.8 (n=5), and the enhancement factors (EFs) were 4.0-42.6. Copyright © 2013 Elsevier B.V. All rights reserved.

A Study of Al-Mn Transition Edge Sensor Engineering for Stability

DOE Office of Scientific and Technical Information (OSTI.GOV)

George, E. M.; et al.

2013-11-10

The stability of Al-Mn transition edge sensor (TES) bolometers is studied as we vary the engineered TES transition, heat capacity, and/or coupling between the heat capacity and TES. We present thermal structure measurements of each of the 39 designs tested. The data is accurately fit by a two-body bolometer model, which allows us to extract the basic TES parameters that affect device stability. We conclude that parameters affecting device stability can be engineered for optimal device operation, and present the model parameters extracted for the different TES designs.

Subcritical n-hexane/isopropanol extraction of lipid from wet microalgal pastes of Scenedesmus obliquus.

PubMed

Bian, Xiaoyu; Jin, Wenbiao; Gu, Qiong; Zhou, Xu; Xi, Yuhe; Tu, Renjie; Han, Song-Fang; Xie, Guo-Jun; Gao, Shu-Hong; Wang, Qilin

2018-02-19

Subcritical co-solvents of n-hexane/isopropanol were primarily utilized to extract lipid from wet microalgal pastes of Scenedesmus obliquus. The effects of key operational parameters were investigated, and the optimal parameters were obtained: solvent ratio of n-hexane to isopropanol was 3:2 (V:V), phase ratio of co-solvents to microalgal biomass was 35:1 (mL:g), reactor stirring speed was 900 rpm, extraction time was 60 min. Additional pretreatment with acid, ultrasonic and microwave as well as enhanced subcritical pressure/heating treatments were also applied to further study their effects on lipid extraction. The results showed that the lipid recovery rate with acid pretreatment was 8.6 and 6.2% higher than ultrasonic and microwave pretreatment; the optimum enhanced subcritical condition was 55 °C with atmospheric pressure. Under optimal operating conditions, the lipid and FAME yield were 13.5 and 7.2%, which was 82.6 and 135.1% higher than the traditional method. The results indicated that the subcritical n-hexane/isopropanol extraction process had promising application potential.

Optimization of Aqueous Extraction from Kalanchoe pinnata Leaves to Obtain the Highest Content of an Anti-inflammatory Flavonoid using a Response Surface Model.

PubMed

Dos Santos Nascimento, Luana Beatriz; de Aguiar, Paula Fernandes; Leal-Costa, Marcos Vinicius; Coutinho, Marcela Araújo Soares; Borsodi, Maria Paula Gonçalves; Rossi-Bergmann, Bartira; Tavares, Eliana Schwartz; Costa, Sônia Soares

2018-05-01

The medicinal plant Kalanchoe pinnata is a phenolic-rich species used worldwide. The reports on its pharmacological uses have increased by 70% in the last 10 years. The leaves of this plant are the main source of an unusual quercetin-diglycosyl flavonoid (QAR, quercetin arabinopyranosyl rhamnopyranoside), which can be easily extracted using water. QAR possess a strong in vivo anti-inflammatory activity. To optimize the aqueous extraction of QAR from K. pinnata leaves using a three-level full factorial design. After a previous screening design, time (x 1 ) and temperature (x 2 ) were chosen as the two independent variables for optimization. Freeze-dried leaves were extracted with water (20% w/v), at 30°C, 40°C or 50°C for 5, 18 or 30 min. QAR content (determined by HPLC-DAD) and yield of extracts were analyzed. The optimized extracts were also evaluated for cytotoxicity. The optimal heating times for extract yield and QAR content were similar in two-dimensional (2D) surface responses (between 12.8 and 30 min), but their optimal extraction temperatures were ranged between 40°C and 50°C for QAR content and 30°C and 38°C for extract yield. A compromise region for both parameters was at the mean points that were 40°C for the extraction temperature and 18 min for the total time. The optimized process is faster and spends less energy than the previous one (water; 30 min at 55°C); therefore is greener and more attractive for industrial purposes. This is the first report of extraction optimization of this bioactive flavonoid. Copyright © 2018 John Wiley & Sons, Ltd. Copyright © 2018 John Wiley & Sons, Ltd.

Integrated feature extraction and selection for neuroimage classification

NASA Astrophysics Data System (ADS)

Fan, Yong; Shen, Dinggang

2009-02-01

Feature extraction and selection are of great importance in neuroimage classification for identifying informative features and reducing feature dimensionality, which are generally implemented as two separate steps. This paper presents an integrated feature extraction and selection algorithm with two iterative steps: constrained subspace learning based feature extraction and support vector machine (SVM) based feature selection. The subspace learning based feature extraction focuses on the brain regions with higher possibility of being affected by the disease under study, while the possibility of brain regions being affected by disease is estimated by the SVM based feature selection, in conjunction with SVM classification. This algorithm can not only take into account the inter-correlation among different brain regions, but also overcome the limitation of traditional subspace learning based feature extraction methods. To achieve robust performance and optimal selection of parameters involved in feature extraction, selection, and classification, a bootstrapping strategy is used to generate multiple versions of training and testing sets for parameter optimization, according to the classification performance measured by the area under the ROC (receiver operating characteristic) curve. The integrated feature extraction and selection method is applied to a structural MR image based Alzheimer's disease (AD) study with 98 non-demented and 100 demented subjects. Cross-validation results indicate that the proposed algorithm can improve performance of the traditional subspace learning based classification.

Response surface methodology as an approach to determine the optimal activities of xylose reductase and xylitol dehydrogenase enzymes from Candida Mogii.

PubMed

Mayerhoff, Zea D V L; Roberto, Inês C; Franco, Telma T

2006-05-01

A central composite experimental design leading to a set of 16 experiments with different combinations of pH and temperature was performed to attain the optimal activities of xylose reductase (XR) and xylitol dehydrogenase (XDH) enzymes from Candida mogii cell extract. Under optimized conditions (pH 6.5 and 38 degrees C), the XR and XDH activities were found to be 0.48 U/ml and 0.22 U/ml, respectively, resulting in an XR to XDH ratio of 2.2. Stability, cofactor specificity and kinetic parameters of the enzyme XR were also evaluated. XR activity remained stable for 3 h under 4 and 38 degrees C and for 4 months of storage at -18 degrees C. Studies on cofactor specificity showed that only NADPH-dependent XR was obtained under the cultivation conditions employed. The XR present in C. mogii extracts showed a superior Km value for xylose when compared with other yeast strains. Besides, this parameter was not modified after enzyme extraction by aqueous two-phase system.

Subcritical ethanol extraction of flavonoids from Moringa oleifera leaf and evaluation of antioxidant activity.

PubMed

Wang, Yongqiang; Gao, Yujie; Ding, Hui; Liu, Shejiang; Han, Xu; Gui, Jianzhou; Liu, Dan

2017-03-01

A large-scale process to extract flavonoids from Moringa oleifera leaf by subcritical ethanol was developed and HPLC-MS analysis was conducted to qualitatively identify the compounds in the extracts. To optimize the effects of process parameters on the yield of flavonoids, a Box-Behnken design combined with response surface methodology was conducted in the present work. The results indicated that the highest extraction yield of flavonoids by subcritical ethanol extraction could reach 2.60% using 70% ethanol at 126.6°C for 2.05h extraction. Under the optimized conditions, flavonoids yield was substantially improved by 26.7% compared with the traditional ethanol reflux method while the extraction time was only 2h, and obvious energy saving was observed. FRAP and DPPH assays showed that the extracts had strong antioxidant and free radical scavenging activities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimization of microwave-assisted extraction of total extract, stevioside and rebaudioside-A from Stevia rebaudiana (Bertoni) leaves, using response surface methodology (RSM) and artificial neural network (ANN) modelling.

PubMed

Ameer, Kashif; Bae, Seong-Woo; Jo, Yunhee; Lee, Hyun-Gyu; Ameer, Asif; Kwon, Joong-Ho

2017-08-15

Stevia rebaudiana (Bertoni) consists of stevioside and rebaudioside-A (Reb-A). We compared response surface methodology (RSM) and artificial neural network (ANN) modelling for their estimation and predictive capabilities in building effective models with maximum responses. A 5-level 3-factor central composite design was used to optimize microwave-assisted extraction (MAE) to obtain maximum yield of target responses as a function of extraction time (X 1 : 1-5min), ethanol concentration, (X 2 : 0-100%) and microwave power (X 3 : 40-200W). Maximum values of the three output parameters: 7.67% total extract yield, 19.58mg/g stevioside yield, and 15.3mg/g Reb-A yield, were obtained under optimum extraction conditions of 4min X 1 , 75% X 2 , and 160W X 3 . The ANN model demonstrated higher efficiency than did the RSM model. Hence, RSM can demonstrate interaction effects of inherent MAE parameters on target responses, whereas ANN can reliably model the MAE process with better predictive and estimation capabilities. Copyright © 2017. Published by Elsevier Ltd.

Ultrasound-Assisted Extraction and Identification of Natural Antioxidants from the Fruit of Melastoma sanguineum Sims.

PubMed

Zhou, Tong; Xu, Dong-Ping; Lin, Sheng-Jun; Li, Ya; Zheng, Jie; Zhou, Yue; Zhang, Jiao-Jiao; Li, Hua-Bin

2017-02-18

The fruit of Melastoma sanguineum Sims is an edible and sweet wild fruit. In our previous study, the fruit was found to have a strong antioxidant property. In this study, an ultrasound-assisted extraction (UAE) method was developed to extract natural antioxidants from the fruit of Melastoma sanguineum Sims, and a response surface methodology was used to optimize the conditions of UAE to maximize the extraction efficiency. The influence of five independent extraction parameters (ethanol concentration, solvent/material ratio, extracting time, temperature, and ultrasound power) on the extraction efficiency were investigated using a single factor experiment, and then a central composite rotatable design was used to investigate the interaction of three key parameters. The results showed that the optimal extraction conditions were 42.98% ethanol, 28.29 mL/g solvent/material ratio, 34.29 min extracting time, 60 °C temperature, and 600 W ultrasound power. Under these conditions, the Trolox equivalent antioxidant capacity (TEAC) value of the extracts was 1074.61 ± 32.56 μmol Trolox/g dry weight (DW). Compared with conventional maceration (723.27 ± 11.61 μmol Trolox/g DW) and Soxhlet extraction methods (518.37 ± 23.23 μmol Trolox/g DW), the UAE method improved the extraction efficiency, in a shorter period of time. In addition, epicatechin gallate, epicatechin, rutin, epigallocatechin, protocatechuic acid, chlorogenic acid, and quercetin, were identified and quantified in the fruit extracts of Melastoma sanguineum Sims by UPLC-MS/MS.

Technical Parameters Modeling of a Gas Probe Foaming Using an Active Experimental Type Research

NASA Astrophysics Data System (ADS)

Tîtu, A. M.; Sandu, A. V.; Pop, A. B.; Ceocea, C.; Tîtu, S.

2018-06-01

The present paper deals with a current and complex topic, namely - a technical problem solving regarding the modeling and then optimization of some technical parameters related to the natural gas extraction process. The study subject is to optimize the gas probe sputtering using experimental research methods and data processing by regular probe intervention with different sputtering agents. This procedure makes that the hydrostatic pressure to be reduced by the foam formation from the water deposit and the scrubbing agent which can be removed from the surface by the produced gas flow. The probe production data was analyzed and the so-called candidate for the research itself emerged. This is an extremely complex study and it was carried out on the field works, finding that due to the severe gas field depletion the wells flow decreases and the start of their loading with deposit water, was registered. It was required the regular wells foaming, to optimize the daily production flow and the disposal of the wellbore accumulated water. In order to analyze the process of natural gas production, the factorial experiment and other methods were used. The reason of this choice is that the method can offer very good research results with a small number of experimental data. Finally, through this study the extraction process problems were identified by analyzing and optimizing the technical parameters, which led to a quality improvement of the extraction process.

Maximum likelihood identification and optimal input design for identifying aircraft stability and control derivatives

NASA Technical Reports Server (NTRS)

Stepner, D. E.; Mehra, R. K.

1973-01-01

A new method of extracting aircraft stability and control derivatives from flight test data is developed based on the maximum likelihood cirterion. It is shown that this new method is capable of processing data from both linear and nonlinear models, both with and without process noise and includes output error and equation error methods as special cases. The first application of this method to flight test data is reported for lateral maneuvers of the HL-10 and M2/F3 lifting bodies, including the extraction of stability and control derivatives in the presence of wind gusts. All the problems encountered in this identification study are discussed. Several different methods (including a priori weighting, parameter fixing and constrained parameter values) for dealing with identifiability and uniqueness problems are introduced and the results given. The method for the design of optimal inputs for identifying the parameters of linear dynamic systems is also given. The criterion used for the optimization is the sensitivity of the system output to the unknown parameters. Several simple examples are first given and then the results of an extensive stability and control dervative identification simulation for a C-8 aircraft are detailed.

Celestial Object Imaging Model and Parameter Optimization for an Optical Navigation Sensor Based on the Well Capacity Adjusting Scheme.

PubMed

Wang, Hao; Jiang, Jie; Zhang, Guangjun

2017-04-21

The simultaneous extraction of optical navigation measurements from a target celestial body and star images is essential for autonomous optical navigation. Generally, a single optical navigation sensor cannot simultaneously image the target celestial body and stars well-exposed because their irradiance difference is generally large. Multi-sensor integration or complex image processing algorithms are commonly utilized to solve the said problem. This study analyzes and demonstrates the feasibility of simultaneously imaging the target celestial body and stars well-exposed within a single exposure through a single field of view (FOV) optical navigation sensor using the well capacity adjusting (WCA) scheme. First, the irradiance characteristics of the celestial body are analyzed. Then, the celestial body edge model and star spot imaging model are established when the WCA scheme is applied. Furthermore, the effect of exposure parameters on the accuracy of star centroiding and edge extraction is analyzed using the proposed model. Optimal exposure parameters are also derived by conducting Monte Carlo simulation to obtain the best performance of the navigation sensor. Finally, laboratorial and night sky experiments are performed to validate the correctness of the proposed model and optimal exposure parameters.

Celestial Object Imaging Model and Parameter Optimization for an Optical Navigation Sensor Based on the Well Capacity Adjusting Scheme

PubMed Central

Wang, Hao; Jiang, Jie; Zhang, Guangjun

2017-01-01

The simultaneous extraction of optical navigation measurements from a target celestial body and star images is essential for autonomous optical navigation. Generally, a single optical navigation sensor cannot simultaneously image the target celestial body and stars well-exposed because their irradiance difference is generally large. Multi-sensor integration or complex image processing algorithms are commonly utilized to solve the said problem. This study analyzes and demonstrates the feasibility of simultaneously imaging the target celestial body and stars well-exposed within a single exposure through a single field of view (FOV) optical navigation sensor using the well capacity adjusting (WCA) scheme. First, the irradiance characteristics of the celestial body are analyzed. Then, the celestial body edge model and star spot imaging model are established when the WCA scheme is applied. Furthermore, the effect of exposure parameters on the accuracy of star centroiding and edge extraction is analyzed using the proposed model. Optimal exposure parameters are also derived by conducting Monte Carlo simulation to obtain the best performance of the navigation sensor. Finally, laboratorial and night sky experiments are performed to validate the correctness of the proposed model and optimal exposure parameters. PMID:28430132

Recovery of polyhydroxyalkanoates from municipal secondary wastewater sludge.

PubMed

Kumar, Manish; Ghosh, Pooja; Khosla, Khushboo; Thakur, Indu Shekhar

2018-05-01

In the current study, the feasibility of utilizing municipal secondary wastewater sludge for Polyhydroxyalkanoate (PHA) extraction was improved by optimization of various parameters (temperature, duration and concentration of sludge solids). Optimized process parameters resulted in PHA recovery of 0.605 g, significantly higher than un-optimized conditions. The characterization of PHA was carried out by GC-MS, FT-IR and NMR ( 1 H and 13 C) spectroscopy. The PHA profile was found to be dominated by mcl PHA (58%) along with other diverse PHA. The results of the present study show rich diversity of PHA extracted from a raw material which is readily available at minimal cost. In conclusion, exploring the potential of wastes for production of bioplastics not only reduces the cost of bioplastic production, but also provides a sustainable means for waste management. Copyright © 2018 Elsevier Ltd. All rights reserved.

Method optimization for non-equilibrium solid phase microextraction sampling of HAPs for GC/MS analysis

NASA Astrophysics Data System (ADS)

Zawadowicz, M. A.; Del Negro, L. A.

2010-12-01

Hazardous air pollutants (HAPs) are usually present in the atmosphere at pptv-level, requiring measurements with high sensitivity and minimal contamination. Commonly used evacuated canister methods require an overhead in space, money and time that often is prohibitive to primarily-undergraduate institutions. This study optimized an analytical method based on solid-phase microextraction (SPME) of ambient gaseous matrix, which is a cost-effective technique of selective VOC extraction, accessible to an unskilled undergraduate. Several approaches to SPME extraction and sample analysis were characterized and several extraction parameters optimized. Extraction time, temperature and laminar air flow velocity around the fiber were optimized to give highest signal and efficiency. Direct, dynamic extraction of benzene from a moving air stream produced better precision (±10%) than sampling of stagnant air collected in a polymeric bag (±24%). Using a low-polarity chromatographic column in place of a standard (5%-Phenyl)-methylpolysiloxane phase decreased the benzene detection limit from 2 ppbv to 100 pptv. The developed method is simple and fast, requiring 15-20 minutes per extraction and analysis. It will be field-validated and used as a field laboratory component of various undergraduate Chemistry and Environmental Studies courses.

Pressure leaching of chalcopyrite concentrate

NASA Astrophysics Data System (ADS)

Aleksei, Kritskii; Kirill, Karimov; Stanislav, Naboichenko

2018-05-01

The results of chalcopyrite concentrate processing using low-temperature and high-temperature sulfuric acid pressure leaching are presented. A material of the following composition was used, 21.5 Cu, 0.1 Zn, 0.05 Pb, 0.04 Ni, 26.59 S, 24.52 Fe, 16.28 SiO2 (in wt.%). The influence of technological parameters on the degree of copper and iron extraction into the leach solution was studied in the wide range of values. The following conditions were suggested as the optimal for the high-temperature pressure leaching: t = 190 °C, PO2 = 0.5 MPa, CH2SO4 = 15 g/L, L:S = 6:1. At the mentioned parameters, it is possible to extract at least 98% Cu from concentrate into the leaching solution during 100 minutes. The following conditions were suggested as optimal for the low-temperature pressure leaching: t = 105 °C, PO2 = 1.3-1.5 MPa, CH2SO4 = 90 g/L, L:S = 10:1. At the mentioned parameters, it is possible to extract up to 83% Cu from the concentrate into the leach solution during 300-360 minutes.

Parameter extraction of coupling-of-modes equations including coupling between two surface acoustic waves on SiO2/Cu/LiNbO3 structures

NASA Astrophysics Data System (ADS)

Huang, Yulin; Bao, Jingfu; Li, Xinyi; Zhang, Benfeng; Omori, Tatsuya; Hashimoto, Ken-ya

2018-07-01

This paper describes extraction of parameters of an extended coupling-of-modes (COM) model including coupling between Rayleigh and shear-horizontal (SH) surface acoustic waves (SAW) on the SiO2-overlay/Cu-grating/LiNbO3-substrate structure. First, dispersion characteristics of two SAWs are calculated by the finite element method (FEM), and are fitted with those given by the extended COM. Then variation of COM parameters is expressed in polynomials in terms of the SiO2 and Cu thicknesses and the rotation angle Θ of LiNbO3. Then it is shown how the optimal Θ giving the SH SAW suppression changes with the thicknesses. The result agrees well with that obtained directly by FEM. It is also shown the optimal Θ changes abruptly at certain Cu thickness, and is due to decoupling between two SAW modes.

Utility of coupling nonlinear optimization methods with numerical modeling software

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murphy, M.J.

1996-08-05

Results of using GLO (Global Local Optimizer), a general purpose nonlinear optimization software package for investigating multi-parameter problems in science and engineering is discussed. The package consists of the modular optimization control system (GLO), a graphical user interface (GLO-GUI), a pre-processor (GLO-PUT), a post-processor (GLO-GET), and nonlinear optimization software modules, GLOBAL & LOCAL. GLO is designed for controlling and easy coupling to any scientific software application. GLO runs the optimization module and scientific software application in an iterative loop. At each iteration, the optimization module defines new values for the set of parameters being optimized. GLO-PUT inserts the new parametermore » values into the input file of the scientific application. GLO runs the application with the new parameter values. GLO-GET determines the value of the objective function by extracting the results of the analysis and comparing to the desired result. GLO continues to run the scientific application over and over until it finds the ``best`` set of parameters by minimizing (or maximizing) the objective function. An example problem showing the optimization of material model is presented (Taylor cylinder impact test).« less

Analysis of polycyclic aromatic hydrocarbons in water and beverages using membrane-assisted solvent extraction in combination with large volume injection-gas chromatography-mass spectrometric detection.

PubMed

Rodil, Rosario; Schellin, Manuela; Popp, Peter

2007-09-07

Membrane-assisted solvent extraction (MASE) in combination with large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS) was applied for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. The MASE conditions were optimized for achieving high enrichment of the analytes from aqueous samples, in terms of extraction conditions (shaking speed, extraction temperature and time), extraction solvent and composition (ionic strength, sample pH and presence of organic solvent). Parameters like linearity and reproducibility of the procedure were determined. The extraction efficiency was above 65% for all the analytes and the relative standard deviation (RSD) for five consecutive extractions ranged from 6 to 18%. At optimized conditions detection limits at the ng/L level were achieved. The effectiveness of the method was tested by analyzing real samples, such as river water, apple juice, red wine and milk.

Simultaneous determination of 9 heterocyclic aromatic amines in pork products by liquid chromatography coupled with triple quadrupole tandem mass spectrometry

NASA Astrophysics Data System (ADS)

Shen, X. C.; Zhang, Y. L.; Cui, Y. Q.; Xu, L. Y.; Li, X.; Qi, J. H.

2017-07-01

Heterocyclic aromatic amines (HAAs) are potent mutagens that formed at high temperature in cooked, protein-rich food. Owing to their frequent intake, an accurate method is essential to access human health risk of HAAs exposure through detecting these compounds in various heat-treated meat products. In this study, a liquid chromatography-electrospray tandem mass spectrometry (LC--ESI-MS/MS) method was developed to perform the determination of 9 mutagenic heterocyclic amines (HAAs) in meat samples with multiple reaction monitoring (MRM) mode. Ultrasound assisted extraction and diatomaceous earth was employed to extract HAAs from food samples, and the analytes were purified and enriched using tandem solid phase extraction, with propyl sulfonic acid coupled to a C18 cartridge. Two parameters, extraction time and eluent, were carefully optimized to improve the extraction and purification efficiency. The LC separation was carried out using a Zorbax SB-C18 (3.5 μm particle size, 2.1 × 150 mm i.d.) column and optimized some parameters, such as pH, concentration and volume. Under the optimal experimental conditions, recoveries ranged from 52.97% to 97.11% with good quality parameters: limit of detection values between 0.02 and 0.24 ng mL-1, linearity (R2>0.998), and run-to-run and day-to-day precisions lower than 9.81% achieved. To evaluate the performance of the method in high throughput analysis of complex meat samples, the LC-MS/MS method was applied to the analysis of HAAs in three food samples, and the results demonstrated that the method can be used for the trace determination of HAAs in pork samples.

Use of different sample temperatures in a single extraction procedure for the screening of the aroma profile of plant matrices by headspace solid-phase microextraction.

PubMed

Martendal, Edmar; de Souza Silveira, Cristine Durante; Nardini, Giuliana Stael; Carasek, Eduardo

2011-06-17

This study proposes a new approach to the optimization of the extraction of the volatile fraction of plant matrices using the headspace solid-phase microextraction (HS-SPME) technique. The optimization focused on the extraction time and temperature using a CAR/DVB/PDMS 50/30 μm SPME fiber and 100mg of a mixture of plants as the sample in a 15-mL vial. The extraction time (10-60 min) and temperature (5-60 °C) were optimized by means of a central composite design. The chromatogram was divided into four groups of peaks based on the elution temperature to provide a better understanding of the influence of the extraction parameters on the extraction efficiency considering compounds with different volatilities/polarities. In view of the different optimum extraction time and temperature conditions obtained for each group, a new approach based on the use of two extraction temperatures in the same procedure is proposed. The optimum conditions were achieved by extracting for 30 min with a sample temperature of 60 °C followed by a further 15 min at 5 °C. The proposed method was compared with the optimized conventional method based on a single extraction temperature (45 min of extraction at 50 °C) by submitting five samples to both procedures. The proposed method led to better results in all cases, considering as the response both peak area and the number of identified peaks. The newly proposed optimization approach provided an excellent alternative procedure to extract analytes with quite different volatilities in the same procedure. Copyright © 2011 Elsevier B.V. All rights reserved.

Extraction of rapamycin (sirolimus) from Streptomyces rapamycinicus using ultrasound.

PubMed

More, Amol S; Gadalkar, Sagar; Rathod, Virendra K

2017-07-03

The study was designed to investigate the use of ultrasound-assisted extraction (UAE) of rapamycin (sirolimus) from bacterial strain of Streptomyces rapamycinicus NRRL 5491. To achieve the maximum extraction yield, various parameters were optimized which include S. rapamycinicus (10 g) of biomass in toluene (50 mL), temperature (20°C), acoustic intensity (35.67 W/cm 2 ), and duty cycle (40%) for 4 min extraction time with probe tip length of 0.5 cm dipped into extraction solvent from the surface. The maximum extraction yield 60.15 ± 0.01 mg/L was attained under the mentioned optimum parameters. The use of ultrasound for the extraction of rapamycin shows about twofold increase in the yield as compared to the conventional solid-liquid extraction (29.7 ± 0.2 mg/L). The study provides the effective UAE technique to produce potential value-added products.

Optimization of microwave assisted extraction of essential oils from Iranian Rosmarinus officinalis L. using RSM.

PubMed

Akhbari, Maryam; Masoum, Saeed; Aghababaei, Fahimeh; Hamedi, Sepideh

2018-06-01

In this study, the efficiencies of conventional hydro-distillation and novel microwave hydro-distillation methods in extraction of essential oil from Rosemary officinalis leaves have been compared. In order to attain the best yield and also highest quality of the essential oil in the microwave assisted method, the optimal values of operating parameters such as extraction time, microwave irradiation power and water volume to plant mass ratio were investigated using central composite design under response surface methodology. Optimal conditions for obtaining the maximum extraction yield in the microwave assisted method were predicted as follows: extraction time of 85 min, microwave power of 888 W, and water volume to plant mass ratio of 0.5 ml/g. The extraction yield at these predicted conditions was computed as 0.7756%. The qualities of the obtained essential oils under designed experiments were optimized based on total contents of four major compounds (α-pinene, 1,8-cineole, camphor and verbenone) which determined by gas chromatography equipped with mass spectroscopy (GC-MS). The highest essential oil quality (55.87%) was obtained at extraction time of 68 min; microwave irradiation power of 700 W; and water volume to plant mass ratio of zero.

Application of the L-curve in geophysical inverse problems: methodologies for the extraction of the optimal parameter

NASA Astrophysics Data System (ADS)

Bassrei, A.; Terra, F. A.; Santos, E. T.

2007-12-01

Inverse problems in Applied Geophysics are usually ill-posed. One way to reduce such deficiency is through derivative matrices, which are a particular case of a more general family that receive the name regularization. The regularization by derivative matrices has an input parameter called regularization parameter, which choice is already a problem. It was suggested in the 1970's a heuristic approach later called L-curve, with the purpose to provide the optimum regularization parameter. The L-curve is a parametric curve, where each point is associated to a λ parameter. In the horizontal axis one represents the error between the observed data and the calculated one and in the vertical axis one represents the product between the regularization matrix and the estimated model. The ideal point is the L-curve knee, where there is a balance between the quantities represented in the Cartesian axes. The L-curve has been applied to a variety of inverse problems, also in Geophysics. However, the visualization of the knee is not always an easy task, in special when the L-curve does not the L shape. In this work three methodologies are employed for the search and obtainment of the optimal regularization parameter from the L curve. The first criterion is the utilization of Hansen's tool box which extracts λ automatically. The second criterion consists in to extract visually the optimal parameter. By third criterion one understands the construction of the first derivative of the L-curve, and the posterior automatic extraction of the inflexion point. The utilization of the L-curve with the three above criteria were applied and validated in traveltime tomography and 2-D gravity inversion. After many simulations with synthetic data, noise- free as well as data corrupted with noise, with the regularization orders 0, 1, and 2, we verified that the three criteria are valid and provide satisfactory results. The third criterion presented the best performance, specially in cases where the L-curve has an irregular shape.

Orthogonal array design in optimizing the extraction efficiency of active constituents from roots of Panax notoginseng.

PubMed

Dong, T T X; Zhao, K J; Huang, W Z; Leung, K W; Tsim, K W K

2005-08-01

The root of Panax notoginseng (Radix Notoginseng, Sanqi) is a commonly used traditional Chinese medicine, which is mainly cultivated in Wenshan of Yunnan China. The identified active constituents in Radix Notoginseng include saponin, ssavonoid and polysaccharide; however, the levels of these active constituents vary greatly with different extraction processes. This variation causes a serious problem in standardizing the herbal extract. By using HPLC and spectrophotometry, the contents of notoginsenoside R(1), ginsenoside R(g1), R(b1), R(d), and ssavonoids were determined in the extracts of Radix Notoginseng that were derived from different processes of extraction according to an orthogonal array experimental design having three variable parameters: nature of extraction solvent, extraction volume and extraction time. The nature of extraction solvent and extraction volume were two distinct factors in obtaining those active constituents, while the time of extraction was a subordinate factor. The optimized condition of extraction therefore is considered to be 20 volumes of water and extracted for 24 h. In good agreement with the amount of active constituents, the activity of anti-platelet aggregation was found to be the highest in the extract that contained a better yield of the active constituents. The current results provide an optimized extraction method for the quality control of Radix Notoginseng. Copyright (c) 2005 John Wiley & Sons, Ltd.

Enhancement of multimodality texture-based prediction models via optimization of PET and MR image acquisition protocols: a proof of concept

NASA Astrophysics Data System (ADS)

Vallières, Martin; Laberge, Sébastien; Diamant, André; El Naqa, Issam

2017-11-01

Texture-based radiomic models constructed from medical images have the potential to support cancer treatment management via personalized assessment of tumour aggressiveness. While the identification of stable texture features under varying imaging settings is crucial for the translation of radiomics analysis into routine clinical practice, we hypothesize in this work that a complementary optimization of image acquisition parameters prior to texture feature extraction could enhance the predictive performance of texture-based radiomic models. As a proof of concept, we evaluated the possibility of enhancing a model constructed for the early prediction of lung metastases in soft-tissue sarcomas by optimizing PET and MR image acquisition protocols via computerized simulations of image acquisitions with varying parameters. Simulated PET images from 30 STS patients were acquired by varying the extent of axial data combined per slice (‘span’). Simulated T 1-weighted and T 2-weighted MR images were acquired by varying the repetition time and echo time in a spin-echo pulse sequence, respectively. We analyzed the impact of the variations of PET and MR image acquisition parameters on individual textures, and we investigated how these variations could enhance the global response and the predictive properties of a texture-based model. Our results suggest that it is feasible to identify an optimal set of image acquisition parameters to improve prediction performance. The model constructed with textures extracted from simulated images acquired with a standard clinical set of acquisition parameters reached an average AUC of 0.84 +/- 0.01 in bootstrap testing experiments. In comparison, the model performance significantly increased using an optimal set of image acquisition parameters (p = 0.04 ), with an average AUC of 0.89 +/- 0.01 . Ultimately, specific acquisition protocols optimized to generate superior radiomics measurements for a given clinical problem could be developed and standardized via dedicated computer simulations and thereafter validated using clinical scanners.

SPEXTRA: Optimal extraction code for long-slit spectra in crowded fields

NASA Astrophysics Data System (ADS)

Sarkisyan, A. N.; Vinokurov, A. S.; Solovieva, Yu. N.; Sholukhova, O. N.; Kostenkov, A. E.; Fabrika, S. N.

2017-10-01

We present a code for the optimal extraction of long-slit 2D spectra in crowded stellar fields. Its main advantage and difference from the existing spectrum extraction codes is the presence of a graphical user interface (GUI) and a convenient visualization system of data and extraction parameters. On the whole, the package is designed to study stars in crowded fields of nearby galaxies and star clusters in galaxies. Apart from the spectrum extraction for several stars which are closely located or superimposed, it allows the spectra of objects to be extracted with subtraction of superimposed nebulae of different shapes and different degrees of ionization. The package can also be used to study single stars in the case of a strong background. In the current version, the optimal extraction of 2D spectra with an aperture and the Gaussian function as PSF (point spread function) is proposed. In the future, the package will be supplemented with the possibility to build a PSF based on a Moffat function. We present the details of GUI, illustrate main features of the package, and show results of extraction of the several interesting spectra of objects from different telescopes.

Optimal robust control strategy of a solid oxide fuel cell system

NASA Astrophysics Data System (ADS)

Wu, Xiaojuan; Gao, Danhui

2018-01-01

Optimal control can ensure system safe operation with a high efficiency. However, only a few papers discuss optimal control strategies for solid oxide fuel cell (SOFC) systems. Moreover, the existed methods ignore the impact of parameter uncertainty on system instantaneous performance. In real SOFC systems, several parameters may vary with the variation of operation conditions and can not be identified exactly, such as load current. Therefore, a robust optimal control strategy is proposed, which involves three parts: a SOFC model with parameter uncertainty, a robust optimizer and robust controllers. During the model building process, boundaries of the uncertain parameter are extracted based on Monte Carlo algorithm. To achieve the maximum efficiency, a two-space particle swarm optimization approach is employed to obtain optimal operating points, which are used as the set points of the controllers. To ensure the SOFC safe operation, two feed-forward controllers and a higher-order robust sliding mode controller are presented to control fuel utilization ratio, air excess ratio and stack temperature afterwards. The results show the proposed optimal robust control method can maintain the SOFC system safe operation with a maximum efficiency under load and uncertainty variations.

Extraction Optimization, Purification and Physicochemical Properties of Polysaccharides from Gynura medica.

PubMed

Li, Fengwei; Gao, Jian; Xue, Feng; Yu, Xiaohong; Shao, Tao

2016-03-23

Extraction of polysaccharides from Gynura medica (GMPs) was optimized by response surface methodology (RSM). A central composition design including three parameters, namely extraction temperature (X₁), ratio of water to raw material (X₂) and extraction time (X₃), was used. The best conditions were extraction temperature of 91.7 °C, extraction time of 4.06 h and ratio of water to raw material of 29.1 mL/g. Under the optimized conditions, the yield of GMPs was 5.56%, which was similar to the predicted polysaccharides yield of 5.66%. A fraction named GMP-1 was obtained after isolation and purification by DEAE-52 and Sephadex G-100 gel chromatography, respectively. GMP-1, with a molecular weight of 401 kDa, mainly consisted of galacturonic acid (GalA), xylose (Xyl), glucose (Glu). Infrared spectroscopy was used to characterize the major functional groups of GMP-1 and the results indicated that it was an acidic polysaccharide. The antioxidant and α-glucosidase inhibitory activities of GMPs and GMP-1 were determined in vitro. The results indicated that GMPs and GMP-1 show potential for use in functional foods or medicines.

Antiproliferative activity of Curcuma phaeocaulis Valeton extract using ultrasonic assistance and response surface methodology.

PubMed

Wang, Xiaoqin; Jiang, Ying; Hu, Daode

2017-01-02

The objective of the study was to optimize the ultrasonic-assisted extraction of curdione, furanodienone, curcumol, and germacrone from Curcuma phaeocaulis Valeton (Val.) and investigate the antiproliferative activity of the extract. Under the suitable high-performance liquid chromatography condition, the calibration curves for these four tested compounds showed high levels of linearity and the recoveries of these four compounds were between 97.9 and 104.3%. Response surface methodology (RSM) combining central composite design and desirability function (DF) was used to define optimal extraction parameters. The results of RSM and DF revealed that the optimum conditions were obtained as 8 mL g -1 for liquid-solid ratio, 70% ethanol concentration, and 20 min of ultrasonic time. It was found that the surface structures of the sonicated herbal materials were fluffy and irregular. The C. phaeocaulis Val. extract significantly inhibited the proliferation of RKO and HT-29 cells in vitro. The results reveal that the RSM can be effectively used for optimizing the ultrasonic-assisted extraction of bioactive components from C. phaeocaulis Val. for antiproliferative activity.

Microwave-assisted extraction with water for fast extraction and simultaneous RP-HPLC determination of phenolic acids in radix Salviae Miltiorrhizae.

PubMed

Fang, Xinsheng; Wang, Jianhua; Zhou, Hongying; Jiang, Xingkai; Zhu, Lixiang; Gao, Xin

2009-07-01

An optimized microwave-assisted extraction method using water (MAE-W) as the extractant and an efficient HPLC analysis method were first developed for the fast extraction and simultaneous determination of D(+)-(3,4-dihydroxyphenyl) lactic acid (Dla), salvianolic acid B (SaB), and lithospermic acid (La) in radix Salviae Miltiorrhizae. The key parameters of MAE-W were optimized. It was found that the degradation of SaB was inhibited when using the optimized MAE-W and the stable content of Dla, La, and SaB in danshen was obtained. Furthermore, compared to the conventional extraction methods, the proposed MAE-W is a more rapid method with higher yield and lower solvent consumption with a reproducibility (RSD <6%). In addition, using water as extractant is safe and helpful for environment protection, which could be referred to as green extraction. The separation and quantitative determination of the three compounds was carried out by a developed reverse-phase high-performance liquid chromatographic (RP-HPLC) method with UV detection. Highly efficient separation was obtained using gradient solvent system. The optimized HPLC analysis method was validated to have specificity, linearity, precision, and accuracy. The results indicated that MAE-W followed by HPLC-UV determination is an appropriate alternative to previously proposed method for quality control of radix Salviae Miltiorrhizae.

Determination of major aromatic constituents in vanilla using an on-line supercritical fluid extraction coupled with supercritical fluid chromatography.

PubMed

Liang, Yanshan; Liu, Jiaqi; Zhong, Qisheng; Shen, Lingling; Yao, Jinting; Huang, Taohong; Zhou, Ting

2018-04-01

An on-line supercritical fluid extraction coupled with supercritical fluid chromatography method was developed for the determination of four major aromatic constituents in vanilla. The parameters of supercritical fluid extraction were systematically investigated using single factor optimization experiments and response surface methodology by a Box-Behnken design. The modifier ratio, split ratio, and the extraction temperature and pressure were the major parameters which have significant effects on the extraction. While the static extraction time, dynamic extraction time, and recycle time had little influence on the compounds with low polarity. Under the optimized conditions, the relative extraction efficiencies of all the constituents reached 89.0-95.1%. The limits of quantification were in the range of 1.123-4.747 μg. The limits of detection were in the range of 0.3368-1.424 μg. The recoveries of the four analytes were in the range of 76.1-88.9%. The relative standard deviations of intra- and interday precision ranged from 4.2 to 7.6%. Compared with other off-line methods, the present method obtained higher extraction yields for all four aromatic constituents. Finally, this method has been applied to the analysis of vanilla from different sources. On the basis of the results, the on-line supercritical fluid extraction-supercritical fluid chromatography method shows great promise in the analysis of aromatic constituents in natural products. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High performance curcumin subcritical water extraction from turmeric (Curcuma longa L.).

PubMed

Valizadeh Kiamahalleh, Mohammad; Najafpour-Darzi, Ghasem; Rahimnejad, Mostafa; Moghadamnia, Ali Akbar; Valizadeh Kiamahalleh, Meisam

2016-06-01

Curcumin is a hydrophobic polyphenolic compound derived from turmeric rhizome, which consists about 2-5% of the total rhizome content and is a more valuable component of turmeric. For reducing the drawbacks of conventional extraction (using organic solvents) of curcumin, the water as a clean solvent was used for extracting curcumin. Subcritical water extraction (SWE) experimental setup was fabricated in a laboratory scale and the influences of some parameters (e.g. extraction temperature, particle size, retention time and pressure) on the yield of extraction were investigated. Optimum extraction conditions such as SWE pressure of 10bar, extractive temperature of 140°C, particle size of 0.71mm and retention time of 14min were defined. The maximum amount of curcumin extracted at the optimum condition was 3.8wt%. The yield of curcumin extraction was more than 76wt% with regards to the maximum possible curcumin content of turmeric, as known to be 5%. The scanning electron microscope (SEM) images from the outer surface of turmeric, before and after extraction, clearly demonstrated the effect of each parameter; changes in porosity and hardness of turmeric that is directly related to the amount of extracted curcumin in process optimization of the extraction parameters. Copyright © 2016 Elsevier B.V. All rights reserved.

First results from negative ion beam extraction in ROBIN in surface mode

NASA Astrophysics Data System (ADS)

Pandya, Kaushal; Gahlaut, Agrajit; Yadav, Ratnakar K.; Bhuyan, Manas; Bandyopadhyay, Mainak; Das, B. K.; Bharathi, P.; Vupugalla, Mahesh; Parmar, K. G.; Tyagi, Himanshu; Patel, Kartik; Bhagora, Jignesh; Mistri, Hiren; Prajapati, Bhavesh; Pandey, Ravi; Chakraborty, Arun. K.

2017-08-01

ROBIN, the first step in the Indian R&D program on negative ion beams has reached an important milestone, with the production of negative ions in the surface conversion mode through Cesium (Cs) vapor injection into the source. In the present set-up, negative hydrogen ion beam extraction is effected through an extraction area of ˜73.38 cm2 (146 apertures of 8mm diameter). The three grid electrostatic accelerator system of ROBIN is fed by high voltage DC power supplies (Extraction Power Supply System: 11kV, 35A and Acceleration Power Supply System: 35kV, 15A). Though, a considerable reduction of co-extracted electron current is usually observed during surface mode operation, in order to increase the negative ion current, various other parameters such as plasma grid temperature, plasma grid bias, extraction to acceleration voltage ratio, impurity control and Cs recycling need to be optimized. In the present experiments, to control and to understand the impurity behavior, a Cryopump (14,000 l/s for Hydrogen) is installed along with a Residual Gas Analyzer (RGA). To characterize the source plasma, two sets of Langmuir probes are inserted through the diagnostic flange ports available at the extraction plane. To characterize the beam properties, thermal differential calorimeter, Doppler Shift Spectroscopy and electrical current measurements are implemented in ROBIN. In the present set up, all the negative ion beam extraction experiments have been performed by varying different experimental parameters e.g. RF power (30-70 kW), source operational pressure (0.3 - 0.6Pa), plasma grid bias voltage, extraction & acceleration voltage combination etc. The experiments in surface mode operation is resulted a reduction of co-extracted electron current having electron to ion ratio (e/i) ˜2 whereas the extracted negative ion current density was increased. However, further increase in negative ion current density is expected to be improved after a systematic optimization of the operational parameters and Cs conditioning of the source. It was also found out that a better performance of ROBIN is achieved in the pressure range: 0.5-0.6 Pa. In this paper, the preliminary results on parametric study of ROBIN operation and beam optimization in surface mode are discussed.

Optimization of gelatine extraction from grass carp (Catenopharyngodon idella) fish skin by response surface methodology.

PubMed

Kasankala, Ladislaus M; Xue, Yan; Weilong, Yao; Hong, Sun D; He, Qian

2007-12-01

To establish the optimum gelatine extraction conditions from grass carp fish skin, response surface methodology (RSM) was adopted in this study. The effects of concentration of HCl (%, A), pre-treatment time (h, B), extraction temperature ( degrees C, C) and extraction time (h, D) were studied. The responses were yield (%) and gel strength (g). A=1.19%, B=24 h, C=52.61 degrees C and D=5.12h were determined as the optimum conditions while the predicted responses were 19.83% yield and 267 g gel strength. Gelling and melting points were 19.5 degrees C and 26.8 degrees C, respectively. Moreover, grass carp gelatine showed high contents of imino acids (proline and hydroxyproline) 19.47%. RSM provided a powerful tool to optimize the extraction parameters and the results may be adapted for industrial extraction of gelatine from grass carp fish skins.

Optimization of Supercritical Carbon Dioxide Extraction of Eucommia ulmoides Seed Oil and Quality Evaluation of the Oil.

PubMed

Zhang, Zhen-Shan; Liu, Yu-Lan; Che, Li-Ming

2018-03-01

Supercritical carbon dioxide extraction (SC-CO 2 ) technology was used to extract oil from Eucommia ulmoides seed. The optimum conditions and significant parameters in SC-CO 2 were obtained using response surface methodology (RSM). The qualities of the extracted oil were evaluated by physicochemical properties, fatty acid composition, vitamin E composition. It was found that the optimum extraction parameters were at pressure of 37 MPa, temperature of 40°C, extraction time of 125 min and CO 2 flow rate of 2.6 SL/min. Pressure, temperature and time were identified as significant parameter effecting on extraction yield. The importance of evaluated parameters decreased in the order of pressure > extraction time > temperature > CO 2 flow rate. GC analysis indicated that E. ulmoides seed oil contained about 61% of linolenic acid and its fatty acid composition was similar with that of flaxseed oil and perilla oil. The content and composition of vitamin E was determined using HPLC. The E. ulmoides seed oil was rich in vitamin E (190.72 mg/100 g), the predominant vitamin E isomers were γ- tocopherol and δ- tocopherol, which accounted for 70.87% and 24.81% of the total vitamin E, respectively. The high yield and good physicochemical properties of extracted oil support the notion that SC-CO 2 technology is an effective technique for extracting oil from E. ulmoides seed.

Soy Sauce Residue Oil Extracted by a Novel Continuous Phase Transition Extraction under Low Temperature and Its Refining Process.

PubMed

Zhao, Lichao; Zhang, Yong; He, Liping; Dai, Weijie; Lai, Yingyi; Yao, Xueyi; Cao, Yong

2014-04-09

On the basis of previous single-factor experiments, extraction parameters of soy sauce residue (SSR) oil extracted using a self-developed continuous phase transition extraction method at low temperature was optimized using the response surface methodology. The established optimal conditions for maximum oil yield were n-butane solvent, 0.5 MPa extraction pressure, 45 °C temperature, 62 min extraction time, and 45 mesh raw material granularity. Under these conditions, the actual yield was 28.43% ± 0.17%, which is relatively close to the predicted yield. Meanwhile, isoflavone was extracted from defatted SSR using the same method, but the parameters and solvent used were altered. The new solvent was 95% (v/v) ethanol, and extraction was performed under 1.0 MPa at 60 °C for 90 min. The extracted isoflavones, with 0.18% ± 0.012% yield, mainly comprised daidzein and genistein, two kinds of aglycones. The novel continuous phase transition extraction under low temperature could provide favorable conditions for the extraction of nonpolar or strongly polar substances. The oil physicochemical properties and fatty acids compositions were analyzed. Results showed that the main drawback of the crude oil was the excess of acid value (AV, 63.9 ± 0.1 mg KOH/g) and peroxide value (POV, 9.05 ± 0.3 mmol/kg), compared with that of normal soybean oil. However, through molecular distillation, AV and POV dropped to 1.78 ± 0.12 mg KOH/g and 5.9 ± 0.08 mmol/kg, respectively. This refined oil may be used as feedstuff oil.

Study of optimal extraction conditions for achieving high yield and antioxidant activity of tomato seed oil.

PubMed

Shao, Dongyan; Atungulu, Griffiths G; Pan, Zhongli; Yue, Tianli; Zhang, Ang; Li, Xuan

2012-08-01

Value of tomato seed has not been fully recognized. The objectives of this research were to establish suitable processing conditions for extracting oil from tomato seed by using solvent, determine the impact of processing conditions on yield and antioxidant activity of extracted oil, and elucidate kinetics of the oil extraction process. Four processing parameters, including time, temperature, solvent-to-solid ratio and particle size were studied. A second order model was established to describe the oil extraction process. Based on the results, increasing temperature, solvent-to-solid ratio, and extraction time increased oil yield. In contrast, larger particle size reduced the oil yield. The recommended oil extraction conditions were 8 min of extraction time at temperature of 25 °C, solvent-to-solids ratio of 5/1 (v/w) and particle size of 0.38 mm, which gave oil yield of 20.32% with recovery rate of 78.56%. The DPPH scavenging activity of extracted oil was not significantly affected by the extraction parameters. The inhibitory concentration (IC(50) ) of tomato seed oil was 8.67 mg/mL which was notably low compared to most vegetable oils. A 2nd order model successfully described the kinetics of tomato oil extraction process and parameters of extraction kinetics including initial extraction rate (h), equilibrium concentration of oil (C(s) ), and the extraction rate constant (k) could be precisely predicted with R(2) of at least 0.957. The study revealed that tomato seed which is typically treated as a low value byproduct of tomato processing has great potential in producing oil with high antioxidant capability. The impact of processing conditions including time, temperature, solvent-to-solid ratio and particle size on yield, and antioxidant activity of extracted tomato seed oil are reported. Optimal conditions and models which describe the extraction process are recommended. The information is vital for determining the extraction processing conditions for industrial production of high quality tomato seed oil. Journal of Food Science © 2012 Institute of Food Technologists® No claim to original US government works.

[Study on the extraction technology and hypoglycemic activity of lectin from Trichosanthes kirilowi].

PubMed

Li, Qiong; Ye, Xiao-Li; Zeng, Hong; Chen, Xin; Li, Xue-Gang

2012-03-01

To extract lectins from Trichosanthes kirilowi and study their hypoglycemic activity. The optimal extraction process included the following parameters were conformed by optimization analysis,lectins extracted from Trichosanthes kirilowi was achieved by ammonium sulfate precipitation; The agglutinate activity was determined by using the agglutination test with 5% human blood cells. Human hepatocarcinoma cell HepG2 and the alloxan-induced diabetic mice model were used to assess hypoglycemic activity of Lectin in Trichosanthes kirilowi. The agglutination indexes of lectins extraction buffer were 32; The cell and mice tests indicated that the lectins exhibited hypoglycemic activity in the 70% saturation. The optimum extraction technology is as follows: extraction with PBS, the material-water ratio is 1:30, the extraction time is 24 h, while the concentration of sodium chloride is 0 mol/L and pH is 7.2. Precipitate lectins by ammonium sulfate in the 70% saturation, centrifugal speed is 10 000 tracted from Trichosanthes kirilowi exposes proper hypoglycemic activity.

Water soluble polysaccharides from Spirulina platensis: extraction and in vitro anti-cancer activity.

PubMed

Kurd, Forouzan; Samavati, Vahid

2015-03-01

Polysaccharides from Spirulina platensis algae (SP) were extracted by ultrasound-assisted extraction procedure. The optimal conditions for ultrasonic extraction of SP were determined by response surface methodology. The four parameters were, extraction time (X1), extraction temperature (X2), ultrasonic power (X3) and the ratio of water to raw material (X4), respectively. The experimental data obtained were fitted to a second-order polynomial equation. The optimum conditions were extraction time of 25 min, extraction temperature 85°C, ultrasonic power 90 W and ratio of water to raw material 20 mL/g. Under these optimal conditions, the experimental yield was 13.583±0.51%, well matched with the predicted models with the coefficients of determination (R2) of 0.9971. Then, we demonstrated that SP polysaccharides had strong scavenging activities in vitro on DPPH and hydroxyl radicals. Overall, SP may have potential applications in the medical and food industries. Copyright © 2015 Elsevier B.V. All rights reserved.

Application of response surface methodology for the optimization of supercritical fluid extraction of essential oil from pomegranate (Punica granatum L.) peel.

PubMed

Ara, Katayoun Mahdavi; Raofie, Farhad

2016-07-01

Essential oils and volatile components of pomegranate ( Punica granatum L.) peel of the Malas variety from Meybod, Iran, were extracted using supercritical fluid extraction (SFE) and hydro-distillation methods. The experimental parameters of SFE that is pressure, temperature, extraction time, and modifier (methanol) volume were optimized using a central composite design after a (2 4-1 ) fractional factorial design. Detailed chemical composition of the essential oils and volatile components obtained by hydro-distillation and optimum condition of the supercritical CO 2 extraction were analyzed by GC-MS, and seventy-three and forty-six compounds were identified according to their retention indices and mass spectra, respectively. The optimum SFE conditions were 350 atm pressure, 55 °C temperature, 30 min extraction time, and 150 µL methanol. Results showed that oleic acid, palmitic acid and (-)-Borneol were major compounds in both extracts. The optimum extraction yield was 1.18 % (w/w) for SFE and 0.21 % (v/w) for hydro-distillation.

Optimization of continuous and intermittent microwave extraction of pectin from banana peels.

PubMed

Swamy, Gabriela John; Muthukumarappan, Kasiviswanathan

2017-04-01

Continuous and intermittent microwave-assisted extractions were used to extract pectin from banana peels. Extraction parameters which were employed in the continuous process were microwave power (300-900W), time (100-300s), pH (1-3) and in the intermittent process were microwave power (300-900W), pulse ratio (0.5-1), pH (1-3). The independent factors were optimized with the Box-Behnken response surface design (BBD) (three factor three level) with the desirability function methodology. Results indicate that the independent factors have substantial effect on the pectin yield. Optimized solutions for highest pectin yield (2.18%) from banana peels were obtained with microwave power of 900W, time 100s and pH 3.00 in the continuous method while the intermittent process yielded the highest pectin content (2.58%) at microwave power of 900W, pulse ratio of 0.5 and pH of 3.00. The optimized conditions were validated and close agreement was observed with the validation experiment and predicted value. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimization of microwave-assisted extraction with saponification (MAES) for the determination of polybrominated flame retardants in aquaculture samples.

PubMed

Fajar, N M; Carro, A M; Lorenzo, R A; Fernandez, F; Cela, R

2008-08-01

The efficiency of microwave-assisted extraction with saponification (MAES) for the determination of seven polybrominated flame retardants (polybrominated biphenyls, PBBs; and polybrominated diphenyl ethers, PBDEs) in aquaculture samples is described and compared with microwave-assisted extraction (MAE). Chemometric techniques based on experimental designs and desirability functions were used for simultaneous optimization of the operational parameters used in both MAES and MAE processes. Application of MAES to this group of contaminants in aquaculture samples, which had not been previously applied to this type of analytes, was shown to be superior to MAE in terms of extraction efficiency, extraction time and lipid content extracted from complex matrices (0.7% as against 18.0% for MAE extracts). PBBs and PBDEs were determined by gas chromatography with micro-electron capture detection (GC-muECD). The quantification limits for the analytes were 40-750 pg g(-1) (except for BB-15, which was 1.43 ng g(-1)). Precision for MAES-GC-muECD (%RSD < 11%) was significantly better than for MAE-GC-muECD (%RSD < 20%). The accuracy of both optimized methods was satisfactorily demonstrated by analysis of appropriate certified reference material (CRM), WMF-01.

Bifunctional ultrasound assisted extraction and determination of Elettaria cardamomum Maton essential oil.

PubMed

Sereshti, Hassan; Rohanifar, Ahmad; Bakhtiari, Sadjad; Samadi, Soheila

2012-05-18

A new hyphenated extraction method composed of ultrasound assisted extraction (UAE)-optimized ultrasound assisted emulsification microextraction (USAEME) was developed for the extraction and preconcentration of the essential oil of Elettaria cardamomum Maton. The essential oil was analyzed by gas chromatography-mass spectrometry (GC-MS) and optimization was performed using gas chromatography-flame ionization detection (GC-FID). Ultrasound played two different roles in the extraction of the essential oil. First, as a source of sufficient energy to break the oil-containing glands in order to release the oil, and second as an emulsifier to disperse the organic phase within water. The effective parameters (factors) of USAEME including volume of extraction solvent (C(2)H(4)Cl(2)), extraction temperature and ultrasonic time were optimized by using a central composite design (CCD). The optimal conditions were 120 μL for extraction solvent volume, 32.5 °C for temperature and 10.5 min for ultrasonic time. The linear dynamic ranges (LDRs) were 0.01-50 mg L(-1) with the determination coefficients in the range of 0.9990-0.9999. The limits of detection (LODs) and the relative standard deviations (RSDs) were 0.001-0.007 mg L(-1) and 3.6-6.3%, respectively. The enrichment factors were 93-98. The main components of the extracted essential oil were α-terpenyl acetate (46.0%), 1,8-cineole (27.7%), linalool (5.3%), α-terpineol (4.0%), linalyl acetate (3.5%). Copyright © 2012 Elsevier B.V. All rights reserved.

A novel strategy for isolation and determination of sugars and sugar alcohols from conifers.

PubMed

Sarvin, B A; Seregin, A P; Shpigun, O A; Rodin, I A; Stavrianidi, A N

2018-06-02

The ultrasound-assisted extraction method for isolation of 17 sugars and sugar alcohols from conifers with a subsequent hydrophilic interaction liquid chromatography-tandem mass spectrometry method for their determination is proposed. The optimization of extraction parameters was carried out using Taguchi - L 9 (3 4 ) orthogonal array experimental design for the following parameters-a methanol concentration in the extraction solution, an extraction time, a type of plant sample and an extraction temperature. The optimal ultrasound-assisted extraction conditions were-MeOH concentration - 30% (water - 70%), extraction time - 30 min, type of plant sample - II (grinded leaves 2-4 mm long), extraction temperature - 60 °C. Pure water and acetonitrile were used as eluents in gradient elution mode to separate the analytes. Direct determination of multiple sugars and sugar alcohols was carried out using a mass spectrometric detector operated in a multiple reaction monitoring mode, providing detection limits in the range between 0.1 and 20 ng/mL and good analytical characteristics of the method without derivatization. The developed approach was validated by multiple successive extraction method applied to test its performance on a series of 10 samples, i.e. 2 samples per each of 5 genera: Abies, Larix, Picea, Pinus (Pinaceae) and Juniperus (Cupressaceae), widely distributed in the boreal conifer forests of Eurasia. The novel strategy can be used for profiling of sugars and sugar alcohols in a wide range of plant species. Copyright © 2018. Published by Elsevier B.V.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crowder, Jeff; Cornish, Neil J.; Reddinger, J. Lucas

This work presents the first application of the method of genetic algorithms (GAs) to data analysis for the Laser Interferometer Space Antenna (LISA). In the low frequency regime of the LISA band there are expected to be tens of thousands of galactic binary systems that will be emitting gravitational waves detectable by LISA. The challenge of parameter extraction of such a large number of sources in the LISA data stream requires a search method that can efficiently explore the large parameter spaces involved. As signals of many of these sources will overlap, a global search method is desired. GAs representmore » such a global search method for parameter extraction of multiple overlapping sources in the LISA data stream. We find that GAs are able to correctly extract source parameters for overlapping sources. Several optimizations of a basic GA are presented with results derived from applications of the GA searches to simulated LISA data.« less

Application of solid/liquid extraction for the gravimetric determination of lipids in royal jelly.

PubMed

Antinelli, Jean-François; Davico, Renée; Rognone, Catherine; Faucon, Jean-Paul; Lizzani-Cuvelier, Louisette

2002-04-10

Gravimetric lipid determination is a major parameter for the characterization and the authentication of royal jelly quality. A solid/liquid extraction was compared to the reference method, which is based on liquid/liquid extraction. The amount of royal jelly and the time of the extraction were optimized in comparison to the reference method. Boiling/rinsing ratio and spread of royal jelly onto the extraction thimble were identified as critical parameters, resulting in good accuracy and precision for the alternative method. Comparison of reproducibility and repeatability of both methods associated with gas chromatographic analysis of the composition of the extracted lipids showed no differences between the two methods. As the intra-laboratory validation tests were comparable to the reference method, while offering rapidity and a decrease in amount of solvent used, it was concluded that the proposed method should be used with no modification of quality criteria and norms established for royal jelly characterization.

Contrast Media Administration in Coronary Computed Tomography Angiography - A Systematic Review.

PubMed

Mihl, Casper; Maas, Monique; Turek, Jakub; Seehofnerova, Anna; Leijenaar, Ralph T H; Kok, Madeleine; Lobbes, Marc B I; Wildberger, Joachim E; Das, Marco

2017-04-01

Background  Various different injection parameters influence enhancement of the coronary arteries. There is no consensus in the literature regarding the optimal contrast media (CM) injection protocol. The aim of this study is to provide an update on the effect of different CM injection parameters on the coronary attenuation in coronary computed tomographic angiography (CCTA). Method  Studies published between January 2001 and May 2014 identified by Pubmed, Embase and MEDLINE were evaluated. Using predefined inclusion criteria and a data extraction form, the content of each eligible study was assessed. Initially, 2551 potential studies were identified. After applying our criteria, 36 studies were found to be eligible. Studies were systematically assessed for quality based on the validated Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-II checklist. Results  Extracted data proved to be heterogeneous and often incomplete. The injection protocol and outcome of the included publications were very diverse and results are difficult to compare. Based on the extracted data, it remains unclear which of the injection parameters is the most important determinant for adequate attenuation. It is likely that one parameter which combines multiple parameters (e. g. IDR) will be the most suitable determinant of coronary attenuation in CCTA protocols. Conclusion  Research should be directed towards determining the influence of different injection parameters and defining individualized optimal IDRs tailored to patient-related factors (ideally in large randomized trials). Key points   · This systematic review provides insight into decisive factors on coronary attenuation.. · Different and contradicting outcomes are reported on coronary attenuation in CCTA.. · One parameter combining multiple parameters (IDR) is likely decisive in coronary attenuation.. · Research should aim at defining individualized optimal IDRs tailored to individual factors.. · Future directions should be tailored towards the influence of different injection parameters.. Citation Format · Mihl C, Maas M, Turek J et al. Contrast Media Administration in Coronary Computed Tomography Angiography - A Systematic Review. Fortschr Röntgenstr 2017; 189: 312 - 325. © Georg Thieme Verlag KG Stuttgart · New York.

Supercritical CO2 extraction of candlenut oil: process optimization using Taguchi orthogonal array and physicochemical properties of the oil.

PubMed

Subroto, Erna; Widjojokusumo, Edward; Veriansyah, Bambang; Tjandrawinata, Raymond R

2017-04-01

A series of experiments was conducted to determine optimum conditions for supercritical carbon dioxide extraction of candlenut oil. A Taguchi experimental design with L 9 orthogonal array (four factors in three levels) was employed to evaluate the effects of pressure of 25-35 MPa, temperature of 40-60 °C, CO 2 flow rate of 10-20 g/min and particle size of 0.3-0.8 mm on oil solubility. The obtained results showed that increase in particle size, pressure and temperature improved the oil solubility. The supercritical carbon dioxide extraction at optimized parameters resulted in oil yield extraction of 61.4% at solubility of 9.6 g oil/kg CO 2 . The obtained candlenut oil from supercritical carbon dioxide extraction has better oil quality than oil which was extracted by Soxhlet extraction using n-hexane. The oil contains high unsaturated oil (linoleic acid and linolenic acid), which have many beneficial effects on human health.

Ultrasound-assisted enzymatic extraction and antioxidant activity of polysaccharides from pumpkin (Cucurbita moschata).

PubMed

Wu, Hao; Zhu, Junxiang; Diao, Wenchao; Wang, Chengrong

2014-11-26

An efficient ultrasound-assisted enzymatic extraction (UAEE) of Cucurbita moschata polysaccharides (CMCP) was established and the CMCP antioxidant activities were studied. The UAEE operating parameters (extraction temperature, ultrasonic power, pH, and liquid-to-material ratio) were optimized using the central composite design (CCD) and the mass transfer kinetic study in UAEE procedure was used to select the optimal extraction time. Enzymolysis and ultrasonication that were simultaneously conducted was selected as the UAEE synergistic model and the optimum extraction conditions with a maximum polysaccharide yield of 4.33 ± 0.15% were as follows: extraction temperature, 51.5 °C; ultrasonic power, 440 W; pH, 5.0; liquid-to-material ratio, 5.70:1 mL/g; and extraction time, 20 min. Evaluation of the antioxidant activity in vitro suggested that CMCP has good potential as a natural antioxidant used in the food or medicine industry because of their high reducing power and positive radical scavenging activity for DPPH radical. Copyright © 2014 Elsevier Ltd. All rights reserved.

SIFT optimization and automation for matching images from multiple temporal sources

NASA Astrophysics Data System (ADS)

Castillo-Carrión, Sebastián; Guerrero-Ginel, José-Emilio

2017-05-01

Scale Invariant Feature Transformation (SIFT) was applied to extract tie-points from multiple source images. Although SIFT is reported to perform reliably under widely different radiometric and geometric conditions, using the default input parameters resulted in too few points being found. We found that the best solution was to focus on large features as these are more robust and not prone to scene changes over time, which constitutes a first approach to the automation of processes using mapping applications such as geometric correction, creation of orthophotos and 3D models generation. The optimization of five key SIFT parameters is proposed as a way of increasing the number of correct matches; the performance of SIFT is explored in different images and parameter values, finding optimization values which are corroborated using different validation imagery. The results show that the optimization model improves the performance of SIFT in correlating multitemporal images captured from different sources.

Ultrasound-assisted extraction and preliminary purification of proanthocyanidins and chlorogenic acid from almond (Prunus dulcis) skin.

PubMed

Ma, Xue; Zhou, Xin-Yu; Qiang, Qian-Qian; Zhang, Zhi-Qi

2014-07-01

An aqueous solution of polyethylene glycol (PEG) as a green solvent was employed for the first time to develop the ultrasound-assisted extraction of proanthocyanidins (PA) and chlorogenic acid (CA) from almond skin. The optimized extraction parameters were determined based on response surface methodology, and corresponded to an ultrasound power of 120 W, a liquid-to-solid ratio of 20:1 (mL/g), and a PEG concentration of 50% (v/v). Under these optimized conditions, the extraction yields of PAs and CA from almond skin were 32.68 ± 0.22 and 16.01 ± 0.19 mg/g, respectively. Compared with organic solvent extraction, PEG solution extraction produced higher yields. Different macroporous resins were compared for their performance in purifying PAs and CA from almond skin extract. Static adsorption/desorption experimental results demonstrated that AB-8 resin exhibits excellent purification performance at pH 4. Under the optimized dynamic adsorption/desorption conditions on the AB-8 column, the total recovery of purification for PAs and CA was 80.67%. The total content of PAs and CA in the preliminarily purified extract was 89.17% (with respective contents of 60.90 and 28.27%). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Variability aware compact model characterization for statistical circuit design optimization

NASA Astrophysics Data System (ADS)

Qiao, Ying; Qian, Kun; Spanos, Costas J.

2012-03-01

Variability modeling at the compact transistor model level can enable statistically optimized designs in view of limitations imposed by the fabrication technology. In this work we propose an efficient variabilityaware compact model characterization methodology based on the linear propagation of variance. Hierarchical spatial variability patterns of selected compact model parameters are directly calculated from transistor array test structures. This methodology has been implemented and tested using transistor I-V measurements and the EKV-EPFL compact model. Calculation results compare well to full-wafer direct model parameter extractions. Further studies are done on the proper selection of both compact model parameters and electrical measurement metrics used in the method.

Optimization of Supercritical Fluid Extraction of Total Alkaloids, Peimisine, Peimine and Peiminine from the Bulb of Fritillaria thunbergii Miq, and Evaluation of Antioxidant Activities of the Extracts

PubMed Central

Ruan, Xiao; Yang, Li; Cui, Wen-Xia; Zhang, Men-Xing; Li, Zhao-Hui; Liu, Ben; Wang, Qiang

2016-01-01

Supercritical fluid extraction (SFE) was used to extract total alkaloids, peimisine, peimine and peiminine from the bulb of Fritillaria thunbergii Miq. The antioxidant capacity of the extracts was evaluated by DPPH radical scavenging activity (DPPH-RSA), ABTS radical scavenging activity (ABTS-RSA) and ferric reducing capacity (FRAP) assay. A central composite design (CCD) with four variables and five levels was employed for optimization of process parameters, and response surface plots were constructed in accordance with a second order polynomial model. Under optimal conditions of 3.0 h, 60.4 °C, 26.5 MPa and 89.3% ethanol, the highest yields were predicted to be 3.8 mg/g for total alkaloids, 0.5 mg/g for peimisine, 1.3 mg/g for peimine and 1.3 mg/g for peiminine, and the antioxidant capacity of extracts displayed EC50, DPPH value of 5.5 mg/mL, EC50, ABTS value of 0.3 mg/mL and FRAP value of 118.2 mg ascorbic acid equivalent (AAE)/100 g. PMID:28773648

Formulation and evaluation of herbal anti-acne moisturizer.

PubMed

Rasheed, Arun; Shama, Shaik Neelufar; Joy, Jyothi Mulanjananiyil; Reddy, Bobbu Sravya; Roja, Chirra

2012-10-01

The moisture content present in human skin makes it look young and the use of moisturizer results in fastening the moisture with a surface film of oil. Acne vulgaris is one of the most commonly seen diseases among the youth. The present study is focused on the use of herbs as moisturizer for acne treatment. The anti-acne moisturizer was formulated from herbal crude extracts and investigated the physico-chemical parameters as well as antibacterial activity of the formulation. The study revealed that ethanol extract of Andrographis paniculata, Glycyrrhiza glabra, Ocimum sanctum, Azadiracta indica and Green tea possessed the potential for inhibiting acne. It was observed that the optimal formula of anti-acne moisturizer was satisfactorily effective to control acne inducing bacteria i.e., Staphylococcus epidermis and Propionibacterium. The physico-chemical parameters of the formulation were also optimal with no signs of irritation.

Extracting physicochemical features to predict protein secondary structure.

PubMed

Huang, Yin-Fu; Chen, Shu-Ying

2013-01-01

We propose a protein secondary structure prediction method based on position-specific scoring matrix (PSSM) profiles and four physicochemical features including conformation parameters, net charges, hydrophobic, and side chain mass. First, the SVM with the optimal window size and the optimal parameters of the kernel function is found. Then, we train the SVM using the PSSM profiles generated from PSI-BLAST and the physicochemical features extracted from the CB513 data set. Finally, we use the filter to refine the predicted results from the trained SVM. For all the performance measures of our method, Q 3 reaches 79.52, SOV94 reaches 86.10, and SOV99 reaches 74.60; all the measures are higher than those of the SVMpsi method and the SVMfreq method. This validates that considering these physicochemical features in predicting protein secondary structure would exhibit better performances.

Extracting Physicochemical Features to Predict Protein Secondary Structure

PubMed Central

Chen, Shu-Ying

2013-01-01

We propose a protein secondary structure prediction method based on position-specific scoring matrix (PSSM) profiles and four physicochemical features including conformation parameters, net charges, hydrophobic, and side chain mass. First, the SVM with the optimal window size and the optimal parameters of the kernel function is found. Then, we train the SVM using the PSSM profiles generated from PSI-BLAST and the physicochemical features extracted from the CB513 data set. Finally, we use the filter to refine the predicted results from the trained SVM. For all the performance measures of our method, Q 3 reaches 79.52, SOV94 reaches 86.10, and SOV99 reaches 74.60; all the measures are higher than those of the SVMpsi method and the SVMfreq method. This validates that considering these physicochemical features in predicting protein secondary structure would exhibit better performances. PMID:23766688

Data set for extraction and transesterification of bio-oil from Stoechospermum marginatum, a brown marine algae.

PubMed

Venkatesan, Hariram; Godwin, John J; Sivamani, Seralathan

2017-10-01

The article presents the experimental data on the extraction and transesterification of bio-oil derived from Stoechospermum marginatum, a brown macro marine algae. The samples were collected from Mandapam region, Gulf of Mannar, Tamil Nadu, India. The bio-oil was extracted using Soxhlet technique with a lipid extraction efficiency of 24.4%. Single stage transesterification was adopted due to lower free fatty acid content. The yield of biodiesel was optimized by varying the process parameters. The obtained data showed the optimum process parameters as reaction time 90 min, reaction temperature 65 °C, catalyst concentration 0.50 g and 8:1 M ratio. Furthermore, the data pertaining to the physio-chemical properties of the derived algal biodiesel were also presented.

ECG Based Heart Arrhythmia Detection Using Wavelet Coherence and Bat Algorithm

NASA Astrophysics Data System (ADS)

Kora, Padmavathi; Sri Rama Krishna, K.

2016-12-01

Atrial fibrillation (AF) is a type of heart abnormality, during the AF electrical discharges in the atrium are rapid, results in abnormal heart beat. The morphology of ECG changes due to the abnormalities in the heart. This paper consists of three major steps for the detection of heart diseases: signal pre-processing, feature extraction and classification. Feature extraction is the key process in detecting the heart abnormality. Most of the ECG detection systems depend on the time domain features for cardiac signal classification. In this paper we proposed a wavelet coherence (WTC) technique for ECG signal analysis. The WTC calculates the similarity between two waveforms in frequency domain. Parameters extracted from WTC function is used as the features of the ECG signal. These features are optimized using Bat algorithm. The Levenberg Marquardt neural network classifier is used to classify the optimized features. The performance of the classifier can be improved with the optimized features.

Automatic tissue characterization from ultrasound imagery

NASA Astrophysics Data System (ADS)

Kadah, Yasser M.; Farag, Aly A.; Youssef, Abou-Bakr M.; Badawi, Ahmed M.

1993-08-01

In this work, feature extraction algorithms are proposed to extract the tissue characterization parameters from liver images. Then the resulting parameter set is further processed to obtain the minimum number of parameters representing the most discriminating pattern space for classification. This preprocessing step was applied to over 120 pathology-investigated cases to obtain the learning data for designing the classifier. The extracted features are divided into independent training and test sets and are used to construct both statistical and neural classifiers. The optimal criteria for these classifiers are set to have minimum error, ease of implementation and learning, and the flexibility for future modifications. Various algorithms for implementing various classification techniques are presented and tested on the data. The best performance was obtained using a single layer tensor model functional link network. Also, the voting k-nearest neighbor classifier provided comparably good diagnostic rates.

Sensitivity analysis of coupled processes and parameters on the performance of enhanced geothermal systems.

PubMed

Pandey, S N; Vishal, Vikram

2017-12-06

3-D modeling of coupled thermo-hydro-mechanical (THM) processes in enhanced geothermal systems using the control volume finite element code was done. In a first, a comparative analysis on the effects of coupled processes, operational parameters and reservoir parameters on heat extraction was conducted. We found that significant temperature drop and fluid overpressure occurred inside the reservoirs/fracture that affected the transport behavior of the fracture. The spatio-temporal variations of fracture aperture greatly impacted the thermal drawdown and consequently the net energy output. The results showed that maximum aperture evolution occurred near the injection zone instead of the production zone. Opening of the fracture reduced the injection pressure required to circulate a fixed mass of water. The thermal breakthrough and heat extraction strongly depend on the injection mass flow rate, well distances, reservoir permeability and geothermal gradients. High permeability caused higher water loss, leading to reduced heat extraction. From the results of TH vs THM process simulations, we conclude that appropriate coupling is vital and can impact the estimates of net heat extraction. This study can help in identifying the critical operational parameters, and process optimization for enhanced energy extraction from a geothermal system.

Enhanced and green extraction polyphenols and furanocoumarins from Fig (Ficus carica L.) leaves using deep eutectic solvents.

PubMed

Wang, Tong; Jiao, Jiao; Gai, Qing-Yan; Wang, Peng; Guo, Na; Niu, Li-Li; Fu, Yu-Jie

2017-10-25

Nowadays, green extraction of bioactive compounds from medicinal plants has gained increasing attention. As green solvent, deep eutectic solvent (DES) have been highly rated to replace toxic organic solvents in extraction process. In present study, to simultaneous extraction five main bioactive compounds from fig leaves, DES was tailor-made. The tailor-made DES composed of a 3:3:3 molar ratio of glycerol, xylitol and D-(-)-Fructose showed enhanced extraction yields for five target compounds simultaneously compared with traditional methanol and non-tailor DESs. Then, the tailor-made DES based extraction methods have compared and microwave-assisted extraction was selected and optimized due to its high extraction yields with lower time consumption. The influencing parameters including extraction temperature, liquid-solid ratio, and extraction time were optimized using response surface methodology (RSM). Under optimal conditions the extraction yield of caffeoylmalic acid, psoralic acid-glucoside, rutin, psoralen and bergapten was 6.482mg/g, 16.34mg/g, 5.207mg/g, 15.22mg/g and 2.475mg/g, respectively. Macroporous resin D101 has been used to recovery target compounds with recovery yields of 79.2%, 83.4%, 85.5%, 81.2% and 75.3% for caffeoylmalic acid, psoralic acid-glucoside, rutin, psoralen and bergapten, respectively. The present study suggests that DESs are truly designer and efficient solvents and the method we developed was efficient and sustainable for extraction main compounds from Fig leaves.mg/g. Copyright © 2017 Elsevier B.V. All rights reserved.

Selective determination of caffeine in foods with 3D-graphene based ultrasound-assisted magnetic solid phase extraction.

PubMed

Rahimi, Afshin; Zanjanchi, Mohammad Ali; Bakhtiari, Sadjad; Dehsaraei, Mohammad

2018-10-01

An efficient method was applied for extraction of caffeine in food samples. Three-dimensional graphene-Fe 3 O 4 (3D-G-Fe 3 O 4 ) nanoparticles was successfully synthesized and used as adsorbent in magnetic solid phase extraction (MSPE) step. The properties of synthesized adsorbent were characterized by fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), vibrating sample magnetometer (VSM), X-ray diffraction (XRD), Raman spectroscopy, Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods. The influence of main parameters of extraction procedure such as ultrasound parameter, amount of nanoparticles, pH, salt concentration and desorption condition were investigated and optimized. Under the optimized experimental conditions, the figure of merit results showed excellent linear dynamic range (LDR) of 0.5-500 µg mL -1 , with determination coefficient (R 2 ) higher than 0.996 and limit of detection (LOD) of 0.1 µg mL -1 . Intra- and inter-day relative standard deviations (RSDs) were less than 5.9 and 7.1%, respectively. The method was successfully applied for determination of caffeine in different food samples. Copyright © 2018 Elsevier Ltd. All rights reserved.

Preconcentration and determination of ceftazidime in real samples using dispersive liquid-liquid microextraction and high-performance liquid chromatography with the aid of experimental design.

PubMed

Razmi, Rasoul; Shahpari, Behrouz; Pourbasheer, Eslam; Boustanifar, Mohammad Hasan; Azari, Zhila; Ebadi, Amin

2016-11-01

A rapid and simple method for the extraction and preconcentration of ceftazidime in aqueous samples has been developed using dispersive liquid-liquid microextraction followed by high-performance liquid chromatography analysis. The extraction parameters, such as the volume of extraction solvent and disperser solvent, salt effect, sample volume, centrifuge rate, centrifuge time, extraction time, and temperature in the dispersive liquid-liquid microextraction process, were studied and optimized with the experimental design methods. Firstly, for the preliminary screening of the parameters the taguchi design was used and then, the fractional factorial design was used for significant factors optimization. At the optimum conditions, the calibration curves for ceftazidime indicated good linearity over the range of 0.001-10 μg/mL with correlation coefficients higher than the 0.98, and the limits of detection were 0.13 and 0.17 ng/mL, for water and urine samples, respectively. The proposed method successfully employed to determine ceftazidime in water and urine samples and good agreement between the experimental data and predictive values has been achieved. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimization of dispersive liquid-phase microextraction based on solidified floating organic drop combined with high-performance liquid chromatography for the analysis of glucocorticoid residues in food.

PubMed

Huang, Yuan; Zheng, Zhiqun; Huang, Liying; Yao, Hong; Wu, Xiao Shan; Li, Shaoguang; Lin, Dandan

2017-05-10

A rapid, simple, cost-effective dispersive liquid-phase microextraction based on solidified floating organic drop (SFOD-LPME) was developed in this study. Along with high-performance liquid chromatography, we used the developed approach to determine and enrich trace amounts of four glucocorticoids, namely, prednisone, betamethasone, dexamethasone, and cortisone acetate, in animal-derived food. We also investigated and optimized several important parameters that influenced the extraction efficiency of SFOD-LPME. These parameters include the extractant species, volumes of extraction and dispersant solvents, sodium chloride addition, sample pH, extraction time and temperature, and stirring rate. Under optimum experimental conditions, the calibration graph exhibited linearity over the range of 1.2-200.0ng/ml for the four analytes, with a reasonable linearity(r 2 : 0.9990-0.9999). The enrichment factor was 142-276, and the detection limits was 0.39-0.46ng/ml (0.078-0.23μg/kg). This method was successfully applied to analyze actual food samples, and good spiked recoveries of over 81.5%-114.3% were obtained. Copyright © 2017. Published by Elsevier B.V.

A Poisson nonnegative matrix factorization method with parameter subspace clustering constraint for endmember extraction in hyperspectral imagery

NASA Astrophysics Data System (ADS)

Sun, Weiwei; Ma, Jun; Yang, Gang; Du, Bo; Zhang, Liangpei

2017-06-01

A new Bayesian method named Poisson Nonnegative Matrix Factorization with Parameter Subspace Clustering Constraint (PNMF-PSCC) has been presented to extract endmembers from Hyperspectral Imagery (HSI). First, the method integrates the liner spectral mixture model with the Bayesian framework and it formulates endmember extraction into a Bayesian inference problem. Second, the Parameter Subspace Clustering Constraint (PSCC) is incorporated into the statistical program to consider the clustering of all pixels in the parameter subspace. The PSCC could enlarge differences among ground objects and helps finding endmembers with smaller spectrum divergences. Meanwhile, the PNMF-PSCC method utilizes the Poisson distribution as the prior knowledge of spectral signals to better explain the quantum nature of light in imaging spectrometer. Third, the optimization problem of PNMF-PSCC is formulated into maximizing the joint density via the Maximum A Posterior (MAP) estimator. The program is finally solved by iteratively optimizing two sub-problems via the Alternating Direction Method of Multipliers (ADMM) framework and the FURTHESTSUM initialization scheme. Five state-of-the art methods are implemented to make comparisons with the performance of PNMF-PSCC on both the synthetic and real HSI datasets. Experimental results show that the PNMF-PSCC outperforms all the five methods in Spectral Angle Distance (SAD) and Root-Mean-Square-Error (RMSE), and especially it could identify good endmembers for ground objects with smaller spectrum divergences.

Rapid recovery of high content phytosterols from corn silk.

PubMed

Zhang, Haiyan; Cao, Xiaowan; Liu, Yong; Shang, Fude

2017-10-18

Phytosterols have important physiological and officinal function. An efficient ultrasonic assisted extraction, purification and crystallization procedure of phytosterols was established from corn silk for the first time. The orthogonal test was applied to optimize the process parameters and a maximum phytosterols recovery as high as 10.5886 mg/g was achieved by ultrasonic treatment for 55 min with liquid-solid ratio of 12:1 at 35 °C, 220 w. The ultrasonic extraction temperature (T, °C) has the most significant effect on extraction yield of phytosterols. An orthogonal crystallization test was performed and the optimal conditions [crystallization temperature of 8 °C, time of 12 h and solid-liquid ratio of 1:1 (g/ml)] afforded maximum phytosterols purity of 92.76 ± 0.43%. An efficient extraction and crystallization procedure was established.

Optimization of lipid extraction from Salvinia molesta for biodiesel production using RSM and its FAME analysis.

PubMed

Mubarak, M; Shaija, A; Suchithra, T V

2016-07-01

The higher areal productivity and lipid content of microalgae and aquatic weed makes them the best alternative feedstocks for biodiesel production. Hence, an efficient and economic method of extracting lipid or oil from aquatic weed, Salvinia molesta is an important step towards biodiesel production. Since Salvinia molesta is an unexplored feedstock, its total lipid content was first measured as 16 % using Bligh and Dyer's method which was quite sufficient for further investigation. For extracting more amount of lipid from Salvinia molesta, methanol: chloroform in the ratio 2:1 v/v was identified as the most suitable solvent system using Soxhlet apparatus. Based on the literature and the preliminary experimentations, parameters such as solvent to biomass ratio, temperature, and time were identified as significant for lipid extraction. These parameters were then optimized using response surface methodology with central composite design, where experiments were performed using twenty combinations of these extraction parameters with Minitab-17 software. A lipid yield of 92.4 % from Salvinia molesta was obtained with Soxhlet apparatus using methanol and chloroform (2:1 v/v) as solvent system, at the optimized conditions of temperature (85 °C), solvent to biomass ratio (20:1), and time (137 min), whereas a predicted lipid yield of 93.5 % with regression model. Fatty acid methyl ester (FAME) analysis of S. molesta lipid using gas chromatograph mass spectroscopy (GCMS) with flame ionization detector showed that fatty acids such as C16:0, C16:1, C18:1, and C18:2 contributed more than 9 % weight of total fatty acids. FAME consisted of 56.32, 28.08, and 15.59 % weight of monounsaturated, saturated, and polyunsaturated fatty acids, respectively. Higher cetane number and superior oxidation stability of S. molesta FAME could be attributed to its higher monounsaturated content and lower polyunsaturated content as compared to biodiesels produced from C. vulgaris, Sunflower, and Jatropha.

Fatty acid composition and antioxidant activity of tea (Camellia sinensis L.) seed oil extracted by optimized supercritical carbon dioxide.

PubMed

Wang, Yuefei; Sun, Da; Chen, Hao; Qian, Lisheng; Xu, Ping

2011-01-01

Seeds are another product in addition to leaves (raw materials for teas) of tea (Camellia sinensis L.) plant. The great increase of tea consumption in recent years raises the challenge of finding commercial applications for tea seeds. In the present study, supercritical carbon dioxide (SC-CO(2)) extraction edible oil from tea seed was carried out, response surface methodology (RSM) was used to optimize processing parameters including time (20-90 min), temperature (35-45 °C) and pressure (50-90 MPa). The fatty acid composition and antioxidant activity of the extracted oil was also investigated. The highest yield of oil (29.2 ± 0.6%) was obtained under optimal SC-CO(2) extraction conditions (45 °C, 89.7 min and 32 MPa, respectively), which was significantly higher (p < 0.05) than that (25.3 ± 1.0%) given by Soxhlet extraction. Meanwhile, tea seed oil extracted by SC-CO(2) contained approximately 80% unsaturated fatty acids and showed a much stronger scavenging ability on the DPPH radical than that extracted by Soxhlet. SC-CO(2) is a promising alternative for efficient extraction of edible oil from tea seed. Moreover, tea seed oil extracted by SC-CO(2) is highly edible and has good antioxidant activity, and therefore may play a potential role as a health-promoting food resource in human diets.

Optimization of Ionic Liquid Based Simultaneous Ultrasonic- and Microwave-Assisted Extraction of Rutin and Quercetin from Leaves of Velvetleaf (Abutilon theophrasti) by Response Surface Methodology

PubMed Central

Zhao, Chunjian; Lu, Zhicheng; He, Xin; Li, Zhao; Shi, Kunming; Yang, Lei; Fu, Yujie; Zu, Yuangang

2014-01-01

An ionic liquids based simultaneous ultrasonic and microwave assisted extraction (ILs-UMAE) method has been proposed for the extraction of rutin (RU), quercetin (QU), from velvetleaf leaves. The influential parameters of the ILs-UMAE were optimized by the single factor and the central composite design (CCD) experiments. A 2.00 M 1-butyl-3-methylimidazolium bromide ([C4mim]Br) was used as the experimental ionic liquid, extraction temperature 60°C, extraction time 12 min, liquid-solid ratio 32 mL/g, microwave power of 534 W, and a fixed ultrasonic power of 50 W. Compared to conventional heating reflux extraction (HRE), the RU and QU extraction yields obtained by ILs-UMAE were, respectively, 5.49 mg/g and 0.27 mg/g, which increased, respectively, 2.01-fold and 2.34-fold with the recoveries that were in the range of 97.62–102.36% for RU and 97.33–102.21% for QU with RSDs lower than 3.2% under the optimized UMAE conditions. In addition, the shorter extraction time was used in ILs-UMAE, compared with HRE. Therefore, ILs-UMAE was a rapid and an efficient method for the extraction of RU and QU from the leaves of velvetleaf. PMID:25243207

Fatty Acid Composition and Antioxidant Activity of Tea (Camellia sinensis L.) Seed Oil Extracted by Optimized Supercritical Carbon Dioxide

PubMed Central

Wang, Yuefei; Sun, Da; Chen, Hao; Qian, Lisheng; Xu, Ping

2011-01-01

Seeds are another product in addition to leaves (raw materials for teas) of tea (Camellia sinensis L.) plant. The great increase of tea consumption in recent years raises the challenge of finding commercial applications for tea seeds. In the present study, supercritical carbon dioxide (SC-CO2) extraction edible oil from tea seed was carried out, response surface methodology (RSM) was used to optimize processing parameters including time (20–90 min), temperature (35–45 °C) and pressure (50–90 MPa). The fatty acid composition and antioxidant activity of the extracted oil was also investigated. The highest yield of oil (29.2 ± 0.6%) was obtained under optimal SC-CO2 extraction conditions (45 °C, 89.7 min and 32 MPa, respectively), which was significantly higher (p < 0.05) than that (25.3 ± 1.0%) given by Soxhlet extraction. Meanwhile, tea seed oil extracted by SC-CO2 contained approximately 80% unsaturated fatty acids and showed a much stronger scavenging ability on the DPPH radical than that extracted by Soxhlet. SC-CO2 is a promising alternative for efficient extraction of edible oil from tea seed. Moreover, tea seed oil extracted by SC-CO2 is highly edible and has good antioxidant activity, and therefore may play a potential role as a health-promoting food resource in human diets. PMID:22174626

Electro-driven extraction of inorganic anions from water samples and water miscible organic solvents and analysis by ion chromatography.

PubMed

Nojavan, Saeed; Bidarmanesh, Tina; Memarzadeh, Farkhondeh; Chalavi, Soheila

2014-09-01

A simple electromembrane extraction (EME) procedure combined with ion chromatography (IC) was developed to quantify inorganic anions in different pure water samples and water miscible organic solvents. The parameters affecting extraction performance, such as supported liquid membrane (SLM) solvent, extraction time, pH of donor and acceptor solutions, and extraction voltage were optimized. The optimized EME conditions were as follows: 1-heptanol was used as the SLM solvent, the extraction time was 10 min, pHs of the acceptor and donor solutions were 10 and 7, respectively, and the extraction voltage was 15 V. The mobile phase used for IC was a combination of 1.8 mM sodium carbonate and 1.7 mM sodium bicarbonate. Under these optimized conditions, all anions had enrichment factors ranging from 67 to 117 with RSDs between 7.3 and 13.5% (n = 5). Good linearity values ranging from 2 to 1200 ng/mL with coefficients of determination (R(2) ) between 0.987 and 0.999 were obtained. The LODs of the EME-IC method ranged from 0.6 to 7.5 ng/mL. The developed method was applied to different samples to evaluate the feasibility of the method for real applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimized Extraction of Polysaccharides from Grateloupia livida (Harv.) Yamada and Biological Activities.

PubMed

Ye, Danyan; Jiang, Zebin; Zheng, Fuchun; Wang, Hongmei; Zhang, Yanmei; Gao, Fenfei; Chen, Peihong; Chen, Yicun; Shi, Ganggang

2015-09-16

Polysaccharides from Grateloupia livida (Harv.) Yamada (GL) were extracted by a heating circumfluence method. Single-factor experiments were performed for the three parameters: extraction time (X₁), extraction temperature (X₂) and the ratio of water to raw material (X₃) and their test range. From preliminary experimental results, one type of the response surface methodology, the Box-Behnken design was applied for the optimizing polysaccharide extraction conditions. The experimental data obtained were fitted to a second-order polynomial equation. The optimal conditions were extraction time 5 h, extraction temperature 100 °C and ratio of water to raw material 70 mL/g. Under these conditions, the experimental yield was 39.22% ± 0.09%, which well matched the predicted value (39.25%), with 0.9774 coefficient of determination (R²). GL polysaccharides had scavenging activities for DPPH and hydroxyl radicals in vitro. The scavenging rates for both radicals peaked at 20 mg/mL GL concentration. However, the positive standard, VC (ascorbic acid), possessed stronger antioxidant activities than GL polysaccharides. Furthermore, the anticancer activity of GL polysaccharides on HepG2 cell proliferation increased dose- and time-dependently, but the positive standard, 5-fluorouracil (5-fu) showed more significant anticancer activity in this study. Overall, GL polysaccharides may have potential applications in the medical and food industries.

Integration of phase separation with ultrasound-assisted salt-induced liquid-liquid microextraction for analyzing the fluoroquinones in human body fluids by liquid chromatography.

PubMed

Wang, Huili; Gao, Ming; Wang, Mei; Zhang, Rongbo; Wang, Wenwei; Dahlgren, Randy A; Wang, Xuedong

2015-03-15

Herein, we developed a novel integrated device to perform phase separation based on ultrasound-assisted salt-induced liquid-liquid microextraction for determination of five fluoroquinones (FQs) in human body fluids. The integrated device consisted of three simple HDPE components used to separate the extraction solvent from the aqueous phase prior to retrieving the extractant. A series of extraction parameters were optimized using the response surface method based on central composite design. Optimal conditions consisted of 945μL acetone extraction solvent, pH 2.1, 4.1min stir time, 5.9g Na2SO4, and 4.0min centrifugation. Under optimized conditions, the limits of detection (at S/N=3) were 0.12-0.66μgL(-1), the linear range was 0.5-500μgL(-1) and recoveries were 92.6-110.9% for the five FQs extracted from plasma and urine. The proposed method has several advantages, such as easy construction from inexpensive materials, high extraction efficiency, short extraction time, and compatibility with HPLC analysis. Thus, this method shows excellent prospects for sample pretreatment and analysis of FQs in human body fluids. Copyright © 2015 Elsevier B.V. All rights reserved.

Box-Behnken design based statistical modeling for ultrasound-assisted extraction of corn silk polysaccharide.

PubMed

Prakash Maran, J; Manikandan, S; Thirugnanasambandham, K; Vigna Nivetha, C; Dinesh, R

2013-01-30

In this study, ultrasound assisted extraction (UAE) conditions on the yield of polysaccharide from corn silk were studied using three factors, three level Box-Behnken response surface design. Process parameters, which affect the efficiency of UAE such as extraction temperature (40-60 °C), time (10-30 min) and solid-liquid ratio (1:10-1:30 g/ml) were investigated. The results showed that, the extraction conditions have significant effects on extraction yield of polysaccharide. The obtained experimental data were fitted to a second-order polynomial equation using multiple regression analysis with high coefficient of determination value (R(2)) of 0.994. An optimization study using Derringer's desired function methodology was performed and the optimal conditions based on both individual and combinations of all independent variables (extraction temperature of 56 °C, time of 17 min and solid-liquid ratio of 1:20 g/ml) were determined with maximum polysaccharide yield of 6.06%, which was confirmed through validation experiments. Copyright © 2012 Elsevier Ltd. All rights reserved.

Study on the extraction and purification of glycoprotein from the yellow seahorse, Hippocampus kuda Bleeker

PubMed Central

Su, Yuting; Xu, Yongjian

2015-01-01

The optimum parameters of extraction for glycoprotein from seahorse were examined and determined by Box-Behnken combined with ultrasonic extraction technology. Column chromatography of glycoprotein was used for further purification. The optimal extraction conditions of seahorse glycoprotein were extracting time 4.3 h, salt concentration 0.08 mol/L, extracting temperature 73°C, raw material, and water ratio 1:6. At the optimal conditions, the yield of saccharide reached to 1.123%, and the yield of protein reached to 5.898%. For purifying the crude glycoprotein, the stage renounces of DEAE-52 column chromatography were done, respectively, with 0.05, 0.1, 0.5 mol/L NaHCO3 solution, and further purification was done with Sephadex G-100 column chromatography. Finally, two pieces of seahorse glycoprotein were obtained by the column chromatography, that is, HG-11 and HG-21. The saccharide content was 56.7975% and 39.479%, the protein content was 30.5475% and 51.747%, respectively. PMID:26288722

Effect of C/N Ratio and Media Optimization through Response Surface Methodology on Simultaneous Productions of Intra- and Extracellular Inulinase and Invertase from Aspergillus niger ATCC 20611

PubMed Central

Dinarvand, Mojdeh; Rezaee, Malahat; Masomian, Malihe; Jazayeri, Seyed Davoud; Zareian, Mohsen; Abbasi, Sahar; Ariff, Arbakariya B.

2013-01-01

The study is to identify the extraction of intracellular inulinase (exo- and endoinulinase) and invertase as well as optimization medium composition for maximum productions of intra- and extracellular enzymes from Aspergillus niger ATCC 20611. From two different methods for extraction of intracellular enzymes, ultrasonic method was found more effective. Response surface methodology (RSM) with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. The effect of five main reaction parameters including sucrose, yeast extract, NaNO3, Zn+2, and Triton X-100 on the production of enzymes was analyzed. A modified quadratic model was fitted to the data with a coefficient of determination (R 2) more than 0.90 for all responses. The intra-extracellular inulinase and invertase productions increased in the range from 16 to 8.4 times in the optimized medium (10% (w/v) sucrose, 2.5% (w/v) yeast extract, 2% (w/v) NaNO3, 1.5 mM (v/v) Zn+2, and 1% (v/v) Triton X-100) by RSM and from around 1.2 to 1.3 times greater than in the medium optimized by one-factor-at-a-time, respectively. The results of bioprocesses optimization can be useful in the scale-up fermentation and food industry. PMID:24151605

Optimization of sample preparation variables for wedelolactone from Eclipta alba using Box-Behnken experimental design followed by HPLC identification.

PubMed

Patil, A A; Sachin, B S; Shinde, D B; Wakte, P S

2013-07-01

Coumestan wedelolactone is an important phytocomponent from Eclipta alba (L.) Hassk. It possesses diverse pharmacological activities, which have prompted the development of various extraction techniques and strategies for its better utilization. The aim of the present study is to develop and optimize supercritical carbon dioxide assisted sample preparation and HPLC identification of wedelolactone from E. alba (L.) Hassk. The response surface methodology was employed to study the optimization of sample preparation using supercritical carbon dioxide for wedelolactone from E. alba (L.) Hassk. The optimized sample preparation involves the investigation of quantitative effects of sample preparation parameters viz. operating pressure, temperature, modifier concentration and time on yield of wedelolactone using Box-Behnken design. The wedelolactone content was determined using validated HPLC methodology. The experimental data were fitted to second-order polynomial equation using multiple regression analysis and analyzed using the appropriate statistical method. By solving the regression equation and analyzing 3D plots, the optimum extraction conditions were found to be: extraction pressure, 25 MPa; temperature, 56 °C; modifier concentration, 9.44% and extraction time, 60 min. Optimum extraction conditions demonstrated wedelolactone yield of 15.37 ± 0.63 mg/100 g E. alba (L.) Hassk, which was in good agreement with the predicted values. Temperature and modifier concentration showed significant effect on the wedelolactone yield. The supercritical carbon dioxide extraction showed higher selectivity than the conventional Soxhlet assisted extraction method. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Development and application of computer assisted optimal method for treatment of femoral neck fracture.

PubMed

Wang, Monan; Zhang, Kai; Yang, Ning

2018-04-09

To help doctors decide their treatment from the aspect of mechanical analysis, the work built a computer assisted optimal system for treatment of femoral neck fracture oriented to clinical application. The whole system encompassed the following three parts: Preprocessing module, finite element mechanical analysis module, post processing module. Preprocessing module included parametric modeling of bone, parametric modeling of fracture face, parametric modeling of fixed screw and fixed position and input and transmission of model parameters. Finite element mechanical analysis module included grid division, element type setting, material property setting, contact setting, constraint and load setting, analysis method setting and batch processing operation. Post processing module included extraction and display of batch processing operation results, image generation of batch processing operation, optimal program operation and optimal result display. The system implemented the whole operations from input of fracture parameters to output of the optimal fixed plan according to specific patient real fracture parameter and optimal rules, which demonstrated the effectiveness of the system. Meanwhile, the system had a friendly interface, simple operation and could improve the system function quickly through modifying single module.

Supercritical Carbon Dioxide Extraction of Bioactive Compounds from Ampelopsis grossedentata Stems: Process Optimization and Antioxidant Activity

PubMed Central

Wang, Yuefei; Ying, Le; Sun, Da; Zhang, Shikang; Zhu, Yuejin; Xu, Ping

2011-01-01

Supercritical carbon dioxide (SC-CO2) extraction of bioactive compounds including flavonoids and phenolics from Ampelopsis grossedentata stems was carried out. Extraction parameters such as pressure, temperature, dynamic time and modifier, were optimized using an orthogonal array design of L9 (34), and antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and ferrous ion chelating (FIC) assay. The best conditions obtained for SC-CO2 extraction of flavonoids was 250 bar, 40 °C, 50 min, and with a modifier of methanol/ethanol (1:3, v/v), and that for phenolics extraction was 250 bar, 40 °C, 50 min, and with a modifier of methanol/ethanol (1:1, v/v). Meantime, flavonoids and phenolics were found to be mainly responsible for the DPPH scavenging activity of the extracts, but not for the chelating activity on ferrous ion according to Pearson correlation analysis. Furthermore, several unreported flavonoids such as apigenin, vitexin, luteolin, etc., have been detected in the extracts from A. grossedentata stems. PMID:22072923

Encapsulation optimization of lemon balm antioxidants in calcium alginate hydrogels.

PubMed

Najafi-Soulari, Samira; Shekarchizadeh, Hajar; Kadivar, Mahdi

2016-11-01

Calcium alginate hydrogel beads were used to encapsulate lemon balm extract. Chitosan layer was used to investigate the effect of hydrogel coating. To determine the interactions of antioxidant compounds of extract with encapsulation materials and its stability, microstructure of hydrogel beads was thoroughly monitored using scanning electron microscopy and Fourier transform infrared (FTIR). Total polyphenols content and antiradical activity of lemon balm extract were also evaluated before and after encapsulation. Three significant parameters (lemon balm extract, sodium alginate, and calcium chloride concentrations) were optimized by response surface methodology to obtain maximum encapsulation efficiency. The FTIR spectra showed no interactions between extract and polymers as there were no new band in spectra of alginate hydrogel after encapsulation of active compounds of lemon balm extract. The antioxidant activity of lemon balm extract did not change after encapsulation. Therefore, it was found that alginate is a suitable material for encapsulation of natural antioxidants. Sodium alginate solution concentration, 1.84%, lemon balm extract concentration, 0.4%, and calcium chloride concentration, 0.2% was determined to be the optimum condition to reach maximum encapsulation efficiency.

Ionic liquid-salt aqueous two-phase extraction based on salting-out coupled with high-performance liquid chromatography for the determination of sulfonamides in water and food.

PubMed

Han, Juan; Wang, Yun; Liu, Yan; Li, Yanfang; Lu, Yang; Yan, Yongsheng; Ni, Liang

2013-02-01

Ionic liquid-salt aqueous two-phase extraction coupled with high-performance liquid chromatography with ultraviolet detection was developed for the determination of sulfonamides in water and food samples. In the procedure, the analytes were extracted from the aqueous samples into the ionic liquid top phase in one step. Three sulfonamides, sulfamerazine, sulfamethoxazole, and sulfamethizole were selected here as model compounds for developing and evaluating the method. The effects of various experimental parameters in extraction step were studied using two optimization methods, one variable at a time and Box-Behnken design. The results showed that the amount of sulfonamides did not have effect on the extraction efficiency. Therefore, a three-level Box-Behnken experimental design with three factors, which combined the response surface modeling, was used to optimize sulfonamides extraction. Under the most favorable extraction parameters, the detection limits (S/N = 3) and quantification limits (S/N = 10) of the proposed method for the target compounds were achieved within the range of 0.15-0.3 ng/mL and 0.5-1.0 ng/mL from spiked samples, respectively, which are lower than or comparable with other reported approaches applied to the determination of the same compounds. Finally, the proposed method was successfully applied to the determination of sulfonamide compounds in different water and food samples and satisfactory recoveries of spiked target compounds in real samples were obtained.

Optimization of the microwave-assisted extraction of phlorotannins from Saccharina japonica Aresch and evaluation of the inhibitory effects of phlorotannin-containing extracts on HepG2 cancer cells

NASA Astrophysics Data System (ADS)

He, Zhizhou; Chen, Yongshun; Chen, Yongheng; Liu, Haohuai; Yuan, Guanfu; Fan, Yaming; Chen, Kun

2013-09-01

The use of a microwave-assisted extraction (MAE) method for the extraction of phlorotannins from Saccharina japonica Aresch ( S. japonica) has been evaluated with particular emphasis on the influential parameters, including the ethanol concentration, solid/liquid ratio, extraction time, extraction temperature, and microwave power. The MAE procedure was optimized using single-factor design and orthogonal array design (OAD). The content of total phlorotannins in S. japonica was determined using a Folin-Ciocalteu (FC) assay. A maximum total phlorotannin content of 0.644 mg of phloroglucinol equivalent per gram of dry weight plant (mg PGE/g DW) was obtained using the optimized model, which included an ethanol concentration of 55%, solid/liquid ratio of 1:8, extraction time of 25 min, irradiation power of 400 W, and temperature of 60°C. Under similar conditions, the application of a conventional extraction method led to a lower phlorotannin yield of 0.585 mg PGE/g WD. These results demonstrated that the MAE approach provided better results for the extraction of phlorotannins from S. japonica and was a promising technique for the extraction of phenolic compounds from S. japonica and other materials. In addition, screening tests for the inhibitory activity showed that the phlorotannin-containing extracts significantly inhibited the growth of human hepatocellular carcinoma cells (HepG2) by inducing their apoptosis. The morphological changes that occurred during cell apoptosis were characterized using Hoechst33258 staining.

Two-steps extraction of essential oil, polysaccharides and biphenyl cyclooctene lignans from Schisandra chinensis Baill fruits.

PubMed

Cheng, Zhenyu; Yang, Yingjie; Liu, Yan; Liu, Zhigang; Zhou, Hongli; Hu, Haobin

2014-08-05

A method for two-steps extraction of essential oil, polysaccharides and lignans from Schisandra chinensis Baill had been established. Firstly, S. chinensis was extracted by hydro-distillation, the extracted solution was separated from the water-insoluble residue and precipitated by adding dehydrated alcohol after the essential oil was collected, and then the precipitate as polysaccharide was collected. Finally, second extraction was performed to obtained lignans from the water-insoluble residue with ultrasonic-microwave assisted extraction (UMAE) method. Response surface methodology was employed to optimize the UMAE parameters, the optimal conditions were as follows: microwave power 430W, ethanol concentration 84%, particle size of sample 120-mesh sieves, ratio of water to raw material 15 and extraction time 2.1min. Under these optimized conditions, the total extraction yields of five lignans (Schisandrol A, Schisantherin A, Deoxyschisandrin, Schisandrin B and Schisandrin C) had reached 14.22±0.135mg/g. Compared with the traditional method of direct extraction of different bioactive components in respective procedure, the extraction yields of polysaccharides and the five lignans had reached 99% and 95%, respectively. The mean recoveries of the 5 lignan compounds and polysaccharides were 97.75-101.08% and their RSD value was less than 3.88%.The approach proposed in this study not only improved the extraction yield of lignans, but also elevated the utilization of Schisandra resources. Copyright © 2014 Elsevier B.V. All rights reserved.

Determination of trace amount of cadmium using dispersive liquid-liquid microextraction-slotted quartz tube-flame atomic absorption spectrometry

NASA Astrophysics Data System (ADS)

Fırat, Merve; Bakırdere, Sezgin; Fındıkoğlu, Maral Selin; Kafa, Emine Betül; Yazıcı, Elif; Yolcu, Melda; Büyükpınar, Çağdaş; Chormey, Dotse Selali; Sel, Sabriye; Turak, Fatma

2017-03-01

This study was performed to develop a sensitive analytical method for the determination of cadmium by slotted quartz tube-flame atomic absorption spectrometry (SQT-FAAS) after dispersive liquid-liquid microextraction (DLLME). The parameters affecting the cadmium complex formation and its extraction output were optimized to obtain high extraction efficiency. These included the pH and amount of the buffer solution, and the concentration of the ligand. The DLLME method was comprehensively optimized based on the type and amount of extraction solvent, dispersive solvent and salt. The type and period of mixing needed for a more effective extraction was also investigated. In order to further improve the sensitivity for the determination of cadmium, the flame atomic absorption spectrometry was fitted with a slotted quartz tube to increase the residence time of cadmium atoms in the pathway of incident light from a hollow cathode lamp. The limits of detection and quantitation (LOD and LOQ) for the FAAS were found to be 42 and 140 μg L- 1, respectively. Under the optimum conditions, LOD and LOQ of the FAAS after DLLME were calculated as 1.3 and 4.4 μg L- 1, respectively. Combining both optimized parameters of the DLLME and SQT-FAAS gave 0.5 and 1.5 μg L- 1 as LOD and LOQ, respectively. Accuracy of the method was also checked using a wastewater certified reference material (EU-L-2), and the result was in good agreement with the certified value.

Optimization of extraction parameters of PTP1β (protein tyrosine phosphatase 1β), inhibitory polyphenols, and anthocyanins from Zea mays L. using response surface methodology (RSM).

PubMed

Hwang, Seung Hwan; Kwon, Shin Hwa; Wang, Zhiqiang; Kim, Tae Hyun; Kang, Young-Hee; Lee, Jae-Yong; Lim, Soon Sung

2016-08-26

Protein tyrosine phosphatase expressed in insulin-sensitive tissues (such as liver, muscle, and adipose tissue) has a key role in the regulation of insulin signaling and pathway activation, making protein tyrosine phosphatase a promising target for the treatment of type 2 diabetes mellitus and obesity and response surface methodology (RSM) is an effective statistical technique for optimizing complex processes using a multi-variant approach. In this study, Zea mays L. (Purple corn kernel, PCK) and its constituents were investigated for protein tyrosine phosphatase 1β (PTP1β) inhibitory activity including enzyme kinetic study and to improve total yields of anthocyanins and polyphenols, four extraction parameters, including temperature, time, solid-liquid ratio, and solvent volume, were optimized by RSM. Isolation of seven polyphenols and five anthocyanins was achieved by PTP1β assay. Among them, cyanidin-3-(6"malonylglucoside) and 3'-methoxyhirsutrin showed the highest PTP1β inhibition with IC50 values of 54.06 and 64.04 μM, respectively and 4.52 mg gallic acid equivalent/g (GAE/g) of total polyphenol content (TPC) and 43.02 mg cyanidin-3-glucoside equivalent/100 g (C3GE/100g) of total anthocyanin content (TAC) were extracted at 40 °C for 8 h with a 33 % solid-liquid ratio and a 1:15 solvent volume. Yields were similar to predictions of 4.58 mg GAE/g of TPC and 42.28 mg C3GE/100 g of TAC. These results indicated that PCK and 3'-methoxyhirsutrin and cyanidin-3-(6"malonylglucoside) might be active natural compounds and could be apply by optimizing of extraction process using response surface methodology.

Paroxysmal atrial fibrillation prediction based on HRV analysis and non-dominated sorting genetic algorithm III.

PubMed

Boon, K H; Khalil-Hani, M; Malarvili, M B

2018-01-01

This paper presents a method that able to predict the paroxysmal atrial fibrillation (PAF). The method uses shorter heart rate variability (HRV) signals when compared to existing methods, and achieves good prediction accuracy. PAF is a common cardiac arrhythmia that increases the health risk of a patient, and the development of an accurate predictor of the onset of PAF is clinical important because it increases the possibility to electrically stabilize and prevent the onset of atrial arrhythmias with different pacing techniques. We propose a multi-objective optimization algorithm based on the non-dominated sorting genetic algorithm III for optimizing the baseline PAF prediction system, that consists of the stages of pre-processing, HRV feature extraction, and support vector machine (SVM) model. The pre-processing stage comprises of heart rate correction, interpolation, and signal detrending. After that, time-domain, frequency-domain, non-linear HRV features are extracted from the pre-processed data in feature extraction stage. Then, these features are used as input to the SVM for predicting the PAF event. The proposed optimization algorithm is used to optimize the parameters and settings of various HRV feature extraction algorithms, select the best feature subsets, and tune the SVM parameters simultaneously for maximum prediction performance. The proposed method achieves an accuracy rate of 87.7%, which significantly outperforms most of the previous works. This accuracy rate is achieved even with the HRV signal length being reduced from the typical 30 min to just 5 min (a reduction of 83%). Furthermore, another significant result is the sensitivity rate, which is considered more important that other performance metrics in this paper, can be improved with the trade-off of lower specificity. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultrasonic-assisted enzymatic extraction of phenolics from broccoli (Brassica oleracea L. var. italica) inflorescences and evaluation of antioxidant activity in vitro.

PubMed

Wu, Hao; Zhu, Junxiang; Yang, Long; Wang, Ran; Wang, Chengrong

2015-06-01

An efficient ultrasonic-assisted enzymatic extraction technique was applied to extracting phenolics from broccoli inflorescences without organic solvents. The synergistic model of enzymolysis and ultrasonication simultaneously was selected, and the enzyme combination was optimized by orthogonal test: cellulase 7.5 mg/g FW (fresh weight), pectinase 10 mg/g FW, and papain 1.0 mg/g FW. The operating parameters in ultrasonic-assisted enzymatic extraction were optimized with response surface methodology using Box-Behnken design. The optimal extraction conditions were as follows: ultrasonic power, 440 W; liquid to material ratio, 7.0:1 mL/g; pH value of 6.0 at 54.5 ℃ for 10 min. Under these conditions, the extraction yield of phenolics achieved 1.816 ± 0.0187 mg gallic acid equivalents/gram FW. The free radical scavenging activity of ultrasonic-assisted enzymatic extraction extracts was determined by 1,1-diphenyl-2-picrylhydrazyl·assay with EC50 values of 0.25, and total antioxidant activity was determined by ferric reducing antioxidant power assay with ferric reducing antioxidant power value of 0.998 mmol FeSO4/g compared with the referential ascorbic acid of 1.184 mmol FeSO4/g. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Analysis of trimethoprim, lincomycin, sulfadoxin and tylosin in swine manure using laser diode thermal desorption-atmospheric pressure chemical ionization-tandem mass spectrometry.

PubMed

Solliec, Morgan; Massé, Daniel; Sauvé, Sébastien

2014-10-01

A new extraction method coupled to a high throughput sample analysis technique was developed for the determination of four veterinary antibiotics. The analytes belong to different groups of antibiotics such as chemotherapeutics, sulfonamides, lincosamides and macrolides. Trimethoprim (TMP), sulfadoxin (SFX), lincomycin (LCM) and tylosin (TYL) were extracted from lyophilized manure using a sonication extraction. McIlvaine buffer and methanol (MeOH) were used as extraction buffers, followed by cation-exchange solid phase extraction (SPE) for clean-up. Analysis was performed by laser diode thermal desorption-atmospheric pressure chemical-ionization (LDTD-APCI) tandem mass spectrometry (MS/MS) with selected reaction monitoring (SRM) detection. The LDTD is a high throughput sample introduction method that reduces total analysis time to less than 15s per sample, compared to minutes when using traditional liquid chromatography (LC). Various SPE parameters were optimized after sample extraction: the stationary phase, the extraction solvent composition, the quantity of sample extracted and sample pH. LDTD parameters were also optimized: solvent deposition, carrier gas, laser power and corona discharge. The method limit of detection (MLD) ranged from 2.5 to 8.3 µg kg(-1) while the method limit of quantification (MLQ) ranged from 8.3 to 28µgkg(-1). Calibration curves in the manure matrix showed good linearity (R(2)≥ 0.996) for all analytes and the interday and intraday coefficients of variation were below 14%. Recoveries of analytes from manure ranged from 53% to 69%. The method was successfully applied to real manure samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Novel optimization strategy for tannase production through a modified solid-state fermentation system.

PubMed

Wu, Changzheng; Zhang, Feng; Li, Lijun; Jiang, Zhedong; Ni, Hui; Xiao, Anfeng

2018-01-01

High amounts of insoluble substrates exist in the traditional solid-state fermentation (SSF) system. The presence of these substrates complicates the determination of microbial biomass. Thus, enzyme activity is used as the sole index for the optimization of the traditional SSF system, and the relationship between microbial growth and enzyme synthesis is always ignored. This study was conducted to address this deficiency. All soluble nutrients from tea stalk were extracted using water. The aqueous extract was then mixed with polyurethane sponge to establish a modified SSF system, which was then used to conduct tannase production. With this system, biomass, enzyme activity, and enzyme productivity could be measured rationally and accurately. Thus, the association between biomass and enzyme activity could be easily identified, and the shortcomings of traditional SSF could be addressed. Different carbon and nitrogen sources exerted different effects on microbial growth and enzyme production. Single-factor experiments showed that glucose and yeast extract greatly improved microbial biomass accumulation and that tannin and (NH 4 ) 2 SO 4 efficiently promoted enzyme productivity. Then, these four factors were optimized through response surface methodology. Tannase activity reached 19.22 U/gds when the added amounts of tannin, glucose, (NH 4 ) 2 SO 4 , and yeast extract were 7.49, 8.11, 9.26, and 2.25%, respectively. Tannase activity under the optimized process conditions was 6.36 times higher than that under the initial process conditions. The optimized parameters were directly applied to the traditional tea stalk SSF system. Tannase activity reached 245 U/gds, which is 2.9 times higher than our previously reported value. In this study, a modified SSF system was established to address the shortcomings of the traditional SSF system. Analysis revealed that enzymatic activity and microbial biomass are closely related, and different carbon and nitrogen sources have different effects on microbial growth and enzyme production. The maximal tannase activity was obtained under the optimal combination of nutrient sources that enhances cell growth and tannase accumulation. Moreover, tannase production through the traditional tea stalk SSF was markedly improved when the optimized parameters were applied. This work provides an innovative approach to bioproduction research through SSF.

Particle swarm optimization of the sensitivity of a cryogenic gravitational wave detector

NASA Astrophysics Data System (ADS)

Michimura, Yuta; Komori, Kentaro; Nishizawa, Atsushi; Takeda, Hiroki; Nagano, Koji; Enomoto, Yutaro; Hayama, Kazuhiro; Somiya, Kentaro; Ando, Masaki

2018-06-01

Cryogenic cooling of the test masses of interferometric gravitational wave detectors is a promising way to reduce thermal noise. However, cryogenic cooling limits the incident power to the test masses, which limits the freedom of shaping the quantum noise. Cryogenic cooling also requires short and thick suspension fibers to extract heat, which could result in the worsening of thermal noise. Therefore, careful tuning of multiple parameters is necessary in designing the sensitivity of cryogenic gravitational wave detectors. Here, we propose the use of particle swarm optimization to optimize the parameters of these detectors. We apply it for designing the sensitivity of the KAGRA detector, and show that binary neutron star inspiral range can be improved by 10%, just by retuning seven parameters of existing components. We also show that the sky localization of GW170817-like binaries can be further improved by a factor of 1.6 averaged across the sky. Our results show that particle swarm optimization is useful for designing future gravitational wave detectors with higher dimensionality in the parameter space.

A new model for simulating microbial cyanide production and optimizing the medium parameters for recovering precious metals from waste printed circuit boards.

PubMed

Yuan, Zhihui; Ruan, Jujun; Li, Yaying; Qiu, Rongliang

2018-04-10

Bioleaching is a green recycling technology for recovering precious metals from waste printed circuit boards (WPCBs). However, this technology requires increasing cyanide production to obtain desirable recovery efficiency. Luria-Bertani medium (LB medium, containing tryptone 10 g/L, yeast extract 5 g/L, NaCl 10 g/L) was commonly used in bioleaching of precious metal. In this study, results showed that LB medium did not produce highest yield of cyanide. Under optimal culture conditions (25 °C, pH 7.5), the maximum cyanide yield of the optimized medium (containing tryptone 6 g/L and yeast extract 5 g/L) was 1.5 times as high as that of LB medium. In addition, kinetics and relationship of cell growth and cyanide production was studied. Data of cell growth fitted logistics model well. Allometric model was demonstrated effective in describing relationship between cell growth and cyanide production. By inserting logistics equation into allometric equation, we got a novel hybrid equation containing five parameters. Kinetic data for cyanide production were well fitted to the new model. Model parameters reflected both cell growth and cyanide production process. Copyright © 2018 Elsevier B.V. All rights reserved.

Extraction and Optimization of Potato Starch and Its Application as a Stabilizer in Yogurt Manufacturing

PubMed Central

2018-01-01

Starch is increasingly used as a functional group in many industrial applications and foods due to its ability to work as a thickener. The experimental values of extracting starch from yellow skin potato indicate the processing conditions at 3000 rpm and 15 min as optimum for the highest yield of extracted starch. The effect of adding different concentrations of extracted starch under the optimized conditions was studied to determine the acidity, pH, syneresis, microbial counts, and sensory evaluation in stored yogurt manufactured at 5 °C for 15 days. The results showed that adding sufficient concentrations of starch (0.75%, 1%) could provide better results in terms of the minimum change in the total acidity, decrease in pH, reduction in syneresis, and preferable results for all sensory parameters. The results revealed that the total bacteria count of all yogurt samples increased throughout the storage time. However, adding different concentrations of optimized extracted starch had a significant effect, decreasing the microbial content compared with the control sample (YC). In addition, the results indicated that coliform bacteria were not found during the storage time. PMID:29382115

Simulation of Helium-3 Extraction from Lunar Ilmenite

NASA Technical Reports Server (NTRS)

Kuhlman, K. R.; Kulcinski, G. L.; Schmitt, H. H.

2004-01-01

Knowledge of the trapping mechanisms and diffusion characteristics of solar-wind implanted isotopes in the minerals of the lunar regolith will enable the optimization of the processes to extract solar wind gases from regolith particles. Extraction parameters include the temperature and duration of extraction, particle size, and gas yield. Diffusion data will increase the efficiency and profitability of future mining ventures. This data will also assist in optimizing the evaluations of various potential mining sites based on remote sensing data. For instance, if magnesian ilmenite (Mg,Fel.,Ti03) is found to retain He better than stoichiometric ilmenite (FeTi03), remote sensing data for Mg could be considered in addition to Ti and maturity data. The context of the currently discussed work is the mining of helium-3 for potential use as a fuel for fusion energy generation. However, the potential resources deposited by the solar wind include hydrogen (and derived water), helium-4, nitrogen and carbon. Implantation experiments such as those performed for helium isotopes in ilmenite are important for the optimized extraction of these additional resources. These experiments can easily be reproduced for most elements or isotopes of interest.

Optimization of the trienzyme extraction for the microbiological assay of folate in vegetables.

PubMed

Chen, Liwen; Eitenmiller, Ronald R

2007-05-16

Response surface methodology was applied to optimize the trienzyme digestion for the extraction of folate from vegetables. Trienzyme extraction is a combined enzymatic digestion by protease, alpha-amylase, and conjugase (gamma-glutamyl hydrolase) to liberate the carbohydrate and protein-bound folates from food matrices for total folate analysis. It is the extraction method used in AOAC Official Method 2004.05 for assay of total folate in cereal grain products. Certified reference material (CRM) 485 mixed vegetables was used to represent the matrix of vegetables. Regression and ridge analysis were performed by statistical analysis software. The predicted second-order polynomial model was adequate (R2 = 0.947), without significant lack of fit (p > 0.1). Both protease and alpha-amylase have significant effects on the extraction. Ridge analysis gave an optimum trienzyme digestion time: Pronase, 1.5 h; alpha-amylase, 1.5 h; and conjugase, 3 h. The experimental value for CRM 485 under this optimum digestion was close to the predicted value from the model, confirming the validity and adequacy of the model. The optimized trienzyme digestion condition was applied to five vegetables and yielded higher folate levels than the trienzyme digestion parameters employed in AOAC Official Method 2004.05.

Pressurized liquid extraction of anthocyanins and biflavonoids from Schinus terebinthifolius Raddi: A multivariate optimization.

PubMed

Feuereisen, Michelle M; Gamero Barraza, Mariana; Zimmermann, Benno F; Schieber, Andreas; Schulze-Kaysers, Nadine

2017-01-01

Response surface methodology was employed to investigate the effects of pressurized liquid extraction (PLE) parameters on the recovery of phenolic compounds (anthocyanins, biflavonoids) from Brazilian pepper (Schinus terebinthifolius Raddi) fruits. The effects of temperature, static time, and ethanol as well as acid concentration on the polyphenol yield were described well by quadratic models (p<0.0001). A significant influence of the ethanol concentration (p<0.0001) and several interactions (p<0.05) were identified. Identification of the biflavonoid I3',II8-binaringenin in drupes of S. terebinthifolius was achieved by UHPLC-MS(2). Interestingly, at high extraction temperatures (>75°C), an artifact occurred and was tentatively identified as a diastereomer of I3',II8-binaringenin. Multivariate optimization led to high yields of phenolic compounds from the exocarp/drupes at 100/75°C, 10/10min, 54.5/54.2% ethanol, and 5/0.03% acetic acid. This study demonstrates that PLE is well suited for the extraction of phenolic compounds from S. terebinthifolius and can efficiently be optimized by response surface methodology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimization of the ultrasound-assisted extraction of anthocyanins and total phenolic compounds in mulberry (Morus nigra) pulp.

PubMed

Espada-Bellido, Estrella; Ferreiro-González, Marta; Carrera, Ceferino; Palma, Miguel; Barroso, Carmelo G; Barbero, Gerardo F

2017-03-15

New ultrasound-assisted extraction methods for the determination of anthocyanins and total phenolic compounds present in mulberries have been developed. Several extraction variables, including methanol composition (50-100%), temperature (10-70°C), ultrasound amplitude (30-70%), cycle (0.2-0.7s), solvent pH (3-7) and solvent-solid ratio (10:1.5-20:1.5) were optimized. A Box-Behnken design in conjunction with a response surface methodology was employed to optimize the conditions for the maximum response based on 54 different experiments. Two response variables were considered: total anthocyanins and total phenolic compounds. Extraction temperature and solvent composition were found to be the most influential parameters for anthocyanins (48°C and 76%) and phenolic compounds (64°C and 61%). The developed methods showed high reproducibility and repeatability (RSD<5%). Finally, the new methods were successfully applied to real samples in order to investigate the presence of anthocyanins and total phenolic compounds in several mulberry jams. Copyright © 2016 Elsevier Ltd. All rights reserved.

Simultaneous extraction, identification and quantification of phenolic compounds in Eclipta prostrata using microwave-assisted extraction combined with HPLC-DAD-ESI-MS/MS.

PubMed

Fang, Xinsheng; Wang, Jianhua; Hao, Jifu; Li, Xueke; Guo, Ning

2015-12-01

A simple and rapid method was developed using microwave-assisted extraction (MAE) combined with HPLC-DAD-ESI-MS/MS for the simultaneous extraction, identification, and quantification of phenolic compounds in Eclipta prostrata, a common herb and vegetable in China. The optimized parameters of MAE were: employing 50% ethanol as solvent, microwave power 400 W, temperature 70 °C, ratio of liquid/solid 30 mL/g and extraction time 2 min. Compared to conventional extraction methods, the optimized MAE can avoid the degradation of the phenolic compounds and simultaneously obtained the highest yields of all components faster with less consumption of solvent and energy. Six phenolic acids, six flavonoid glycosides and one coumarin were firstly identified. The phenolic compounds were quantified by HPLC-DAD with good linearity, precision, and accuracy. The extract obtained by MAE showed significant antioxidant activity. The proposed method provides a valuable and green analytical methodology for the investigation of phenolic components in natural plants. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microwave-assisted extraction of silkworm pupal oil and evaluation of its fatty acid composition, physicochemical properties and antioxidant activities.

PubMed

Hu, Bin; Li, Cheng; Zhang, Zhiqing; Zhao, Qing; Zhu, Yadong; Su, Zhao; Chen, Yizi

2017-09-15

Microwave-assisted extraction (MAE) of oil from silkworm pupae was firstly performed in the present research. The response surface methodology was applied to optimize the parameters for MAE. The yield of oil by MAE was 30.16% under optimal conditions of a mixed solvent consisting of ethanol and n-hexane (1:1, v/v), microwave power (360W), liquid to solid ratio (7.5/1mL/g), microwave time (29min). Moreover, oil extracted by MAE was quantitatively (yield) and qualitatively (fatty acid profile) similar to those obtained using Soxhlet extraction (SE), but oil extracted by MAE exhibited favourable physicochemical properties and oxidation stability. Additionally, oil extracted by MAE had a higher content of total phenolic, and it showed stronger antioxidant activities. Scanning electron microscopy revealed that microwave technique efficiently promoted the release of oil by breaking down the cell structure of silkworm pupae. Therefore, MAE can be an effective method for the silkworm pupal oil extraction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modelling and optimization of a wellhead gas flowmeter using concentric pipes

NASA Astrophysics Data System (ADS)

Nec, Yana; Huculak, Greg

2017-09-01

A novel configuration of a landfill wellhead was analysed to measure the flow rate of gas extracted from sanitary landfills. The device provides access points for pressure measurement integral to flow rate computation similarly to orifice and Venturi meters, and has the advantage of eliminating the problem of water condensation often impairing the accuracy thereof. It is proved that the proposed configuration entails comparable computational complexity and negligible sensitivity to geometric parameters. Calibration for the new device was attained using a custom optimization procedure, operating on a quadri-dimensional parameter surface evincing discontinuity and non-smoothness.

Air-assisted liquid-liquid microextraction using floating organic droplet solidification for simultaneous extraction and spectrophotometric determination of some drugs in biological samples through chemometrics methods

NASA Astrophysics Data System (ADS)

Farahmand, Farnaz; Ghasemzadeh, Bahar; Naseri, Abdolhossein

2018-01-01

An air assisted liquid-liquid microextraction by applying the solidification of a floating organic droplet method (AALLME-SFOD) coupled with a multivariate calibration method, namely partial least squares (PLS), was introduced for the fast and easy determination of Atenolol (ATE), Propanolol (PRO) and Carvedilol (CAR) in biological samples via a spectrophotometric approach. The analytes would be extracted from neutral aqueous solution into 1-dodecanol as an organic solvent, using AALLME. In this approach a low-density solvent with a melting point close to room temperature was applied as the extraction solvent. The emulsion was immediately formed by repeatedly pulling in and pushing out the aqueous sample solution and extraction solvent mixture via a 10-mL glass syringe for ten times. After centrifugation, the extractant droplet could be simply collected from the aqueous samples by solidifying the emulsion at a lower than the melting point temperature. In the next step, analytes were back extracted simultaneously into the acidic aqueous solution. Derringer and Suich multi-response optimization were utilized for simultaneous optimizing the parameters of three analytes. This method incorporates the benefits of AALLME and dispersive liquid-liquid microextraction considering the solidification of floating organic droplets (DLLME-SFOD). Calibration graphs under optimized conditions were linear in the range of 0.30-6.00, 0.32-2.00 and 0.30-1.40 μg mL- 1 for ATE, CAR and PRO, respectively. Other analytical parameters were obtained as follows: enrichment factors (EFs) were found to be 11.24, 16.55 and 14.90, and limits of detection (LODs) were determined to be 0.09, 0.10 and 0.08 μg mL- 1 for ATE, CAR and PRO, respectively. The proposed method will require neither a highly toxic chlorinated solvent for extraction nor an organic dispersive solvent in the application process; hence, it is more environmentally friendly.

Air-assisted liquid-liquid microextraction using floating organic droplet solidification for simultaneous extraction and spectrophotometric determination of some drugs in biological samples through chemometrics methods.

PubMed

Farahmand, Farnaz; Ghasemzadeh, Bahar; Naseri, Abdolhossein

2018-01-05

An air assisted liquid-liquid microextraction by applying the solidification of a floating organic droplet method (AALLME-SFOD) coupled with a multivariate calibration method, namely partial least squares (PLS), was introduced for the fast and easy determination of Atenolol (ATE), Propanolol (PRO) and Carvedilol (CAR) in biological samples via a spectrophotometric approach. The analytes would be extracted from neutral aqueous solution into 1-dodecanol as an organic solvent, using AALLME. In this approach a low-density solvent with a melting point close to room temperature was applied as the extraction solvent. The emulsion was immediately formed by repeatedly pulling in and pushing out the aqueous sample solution and extraction solvent mixture via a 10-mL glass syringe for ten times. After centrifugation, the extractant droplet could be simply collected from the aqueous samples by solidifying the emulsion at a lower than the melting point temperature. In the next step, analytes were back extracted simultaneously into the acidic aqueous solution. Derringer and Suich multi-response optimization were utilized for simultaneous optimizing the parameters of three analytes. This method incorporates the benefits of AALLME and dispersive liquid-liquid microextraction considering the solidification of floating organic droplets (DLLME-SFOD). Calibration graphs under optimized conditions were linear in the range of 0.30-6.00, 0.32-2.00 and 0.30-1.40μg mL -1 for ATE, CAR and PRO, respectively. Other analytical parameters were obtained as follows: enrichment factors (EFs) were found to be 11.24, 16.55 and 14.90, and limits of detection (LODs) were determined to be 0.09, 0.10 and 0.08μg mL -1 for ATE, CAR and PRO, respectively. The proposed method will require neither a highly toxic chlorinated solvent for extraction nor an organic dispersive solvent in the application process; hence, it is more environmentally friendly. Copyright © 2017 Elsevier B.V. All rights reserved.

Autopilot for frequency-modulation atomic force microscopy.

PubMed

Kuchuk, Kfir; Schlesinger, Itai; Sivan, Uri

2015-10-01

One of the most challenging aspects of operating an atomic force microscope (AFM) is finding optimal feedback parameters. This statement applies particularly to frequency-modulation AFM (FM-AFM), which utilizes three feedback loops to control the cantilever excitation amplitude, cantilever excitation frequency, and z-piezo extension. These loops are regulated by a set of feedback parameters, tuned by the user to optimize stability, sensitivity, and noise in the imaging process. Optimization of these parameters is difficult due to the coupling between the frequency and z-piezo feedback loops by the non-linear tip-sample interaction. Four proportional-integral (PI) parameters and two lock-in parameters regulating these loops require simultaneous optimization in the presence of a varying unknown tip-sample coupling. Presently, this optimization is done manually in a tedious process of trial and error. Here, we report on the development and implementation of an algorithm that computes the control parameters automatically. The algorithm reads the unperturbed cantilever resonance frequency, its quality factor, and the z-piezo driving signal power spectral density. It analyzes the poles and zeros of the total closed loop transfer function, extracts the unknown tip-sample transfer function, and finds four PI parameters and two lock-in parameters for the frequency and z-piezo control loops that optimize the bandwidth and step response of the total system. Implementation of the algorithm in a home-built AFM shows that the calculated parameters are consistently excellent and rarely require further tweaking by the user. The new algorithm saves the precious time of experienced users, facilitates utilization of FM-AFM by casual users, and removes the main hurdle on the way to fully automated FM-AFM.

Autopilot for frequency-modulation atomic force microscopy

NASA Astrophysics Data System (ADS)

Kuchuk, Kfir; Schlesinger, Itai; Sivan, Uri

2015-10-01

One of the most challenging aspects of operating an atomic force microscope (AFM) is finding optimal feedback parameters. This statement applies particularly to frequency-modulation AFM (FM-AFM), which utilizes three feedback loops to control the cantilever excitation amplitude, cantilever excitation frequency, and z-piezo extension. These loops are regulated by a set of feedback parameters, tuned by the user to optimize stability, sensitivity, and noise in the imaging process. Optimization of these parameters is difficult due to the coupling between the frequency and z-piezo feedback loops by the non-linear tip-sample interaction. Four proportional-integral (PI) parameters and two lock-in parameters regulating these loops require simultaneous optimization in the presence of a varying unknown tip-sample coupling. Presently, this optimization is done manually in a tedious process of trial and error. Here, we report on the development and implementation of an algorithm that computes the control parameters automatically. The algorithm reads the unperturbed cantilever resonance frequency, its quality factor, and the z-piezo driving signal power spectral density. It analyzes the poles and zeros of the total closed loop transfer function, extracts the unknown tip-sample transfer function, and finds four PI parameters and two lock-in parameters for the frequency and z-piezo control loops that optimize the bandwidth and step response of the total system. Implementation of the algorithm in a home-built AFM shows that the calculated parameters are consistently excellent and rarely require further tweaking by the user. The new algorithm saves the precious time of experienced users, facilitates utilization of FM-AFM by casual users, and removes the main hurdle on the way to fully automated FM-AFM.

Autopilot for frequency-modulation atomic force microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuchuk, Kfir; Schlesinger, Itai; Sivan, Uri, E-mail: phsivan@tx.technion.ac.il

2015-10-15

One of the most challenging aspects of operating an atomic force microscope (AFM) is finding optimal feedback parameters. This statement applies particularly to frequency-modulation AFM (FM-AFM), which utilizes three feedback loops to control the cantilever excitation amplitude, cantilever excitation frequency, and z-piezo extension. These loops are regulated by a set of feedback parameters, tuned by the user to optimize stability, sensitivity, and noise in the imaging process. Optimization of these parameters is difficult due to the coupling between the frequency and z-piezo feedback loops by the non-linear tip-sample interaction. Four proportional-integral (PI) parameters and two lock-in parameters regulating these loopsmore » require simultaneous optimization in the presence of a varying unknown tip-sample coupling. Presently, this optimization is done manually in a tedious process of trial and error. Here, we report on the development and implementation of an algorithm that computes the control parameters automatically. The algorithm reads the unperturbed cantilever resonance frequency, its quality factor, and the z-piezo driving signal power spectral density. It analyzes the poles and zeros of the total closed loop transfer function, extracts the unknown tip-sample transfer function, and finds four PI parameters and two lock-in parameters for the frequency and z-piezo control loops that optimize the bandwidth and step response of the total system. Implementation of the algorithm in a home-built AFM shows that the calculated parameters are consistently excellent and rarely require further tweaking by the user. The new algorithm saves the precious time of experienced users, facilitates utilization of FM-AFM by casual users, and removes the main hurdle on the way to fully automated FM-AFM.« less

Electrically assisted liquid-phase microextraction combined with capillary electrophoresis for quantification of propranolol enantiomers in human body fluids.

PubMed

Tabani, Hadi; Fakhari, Ali Reza; Shahsavani, Abolfath; Gharari Alibabaou, Hossein

2014-05-01

In this study, electromembrane extraction (EME) combined with cyclodextrin (CD)-modified capillary electrophoresis (CE) was applied for the extraction, separation, and quantification of propranolol (PRO) enantiomers from biological samples. The PRO enantiomers were extracted from aqueous donor solutions, through a supported liquid membrane (SLM) consisting of 2-nitrophenyl octyl ether (NPOE) impregnated on the wall of the hollow fiber, and into a 20-μL acidic aqueous acceptor solution into the lumen of hollow fiber. Important parameters affecting EME efficiency such as extraction voltage, extraction time, pH of the donor and acceptor solutions were optimized using a Box-Behnken design (BBD). Then, under these optimized conditions, the acceptor solution was analyzed using an optimized CD-modified CE. Several types of CD were evaluated and best results were obtained using a fused-silica capillary with ammonium acetate (80 mM, pH 2.5) containing 8 mM hydroxypropyl-β-CD as a chiral selector, applied voltage of 18 kV, and temperature of 20°C. The relative recoveries were obtained in the range of 78-95%. Finally, the performance of the present method was evaluated for the extraction and determination of PRO enantiomers in real biological samples. © 2014 Wiley Periodicals, Inc.

Quantum cryptography: Security criteria reexamined

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaszlikowski, Dagomir; Liang, Y.C.; Englert, Berthold-Georg

2004-09-01

We find that the generally accepted security criteria are flawed for a whole class of protocols for quantum cryptography. This is so because a standard assumption of the security analysis, namely that the so-called square-root measurement is optimal for eavesdropping purposes, is not true in general. There are rather large parameter regimes in which the optimal measurement extracts substantially more information than the square-root measurement.

A risk-based approach to management of leachables utilizing statistical analysis of extractables.

PubMed

Stults, Cheryl L M; Mikl, Jaromir; Whelehan, Oliver; Morrical, Bradley; Duffield, William; Nagao, Lee M

2015-04-01

To incorporate quality by design concepts into the management of leachables, an emphasis is often put on understanding the extractable profile for the materials of construction for manufacturing disposables, container-closure, or delivery systems. Component manufacturing processes may also impact the extractable profile. An approach was developed to (1) identify critical components that may be sources of leachables, (2) enable an understanding of manufacturing process factors that affect extractable profiles, (3) determine if quantitative models can be developed that predict the effect of those key factors, and (4) evaluate the practical impact of the key factors on the product. A risk evaluation for an inhalation product identified injection molding as a key process. Designed experiments were performed to evaluate the impact of molding process parameters on the extractable profile from an ABS inhaler component. Statistical analysis of the resulting GC chromatographic profiles identified processing factors that were correlated with peak levels in the extractable profiles. The combination of statistically significant molding process parameters was different for different types of extractable compounds. ANOVA models were used to obtain optimal process settings and predict extractable levels for a selected number of compounds. The proposed paradigm may be applied to evaluate the impact of material composition and processing parameters on extractable profiles and utilized to manage product leachables early in the development process and throughout the product lifecycle.

Evaluation of Planetary Boundary Layer Scheme Sensitivities for the Purpose of Parameter Estimation

EPA Science Inventory

Meteorological model errors caused by imperfect parameterizations generally cannot be overcome simply by optimizing initial and boundary conditions. However, advanced data assimilation methods are capable of extracting significant information about parameterization behavior from ...

Parameter optimization of parenchymal texture analysis for prediction of false-positive recalls from screening mammography

NASA Astrophysics Data System (ADS)

Ray, Shonket; Keller, Brad M.; Chen, Jinbo; Conant, Emily F.; Kontos, Despina

2016-03-01

This work details a methodology to obtain optimal parameter values for a locally-adaptive texture analysis algorithm that extracts mammographic texture features representative of breast parenchymal complexity for predicting falsepositive (FP) recalls from breast cancer screening with digital mammography. The algorithm has two components: (1) adaptive selection of localized regions of interest (ROIs) and (2) Haralick texture feature extraction via Gray- Level Co-Occurrence Matrices (GLCM). The following parameters were systematically varied: mammographic views used, upper limit of the ROI window size used for adaptive ROI selection, GLCM distance offsets, and gray levels (binning) used for feature extraction. Each iteration per parameter set had logistic regression with stepwise feature selection performed on a clinical screening cohort of 474 non-recalled women and 68 FP recalled women; FP recall prediction was evaluated using area under the curve (AUC) of the receiver operating characteristic (ROC) and associations between the extracted features and FP recall were assessed via odds ratios (OR). A default instance of mediolateral (MLO) view, upper ROI size limit of 143.36 mm (2048 pixels2), GLCM distance offset combination range of 0.07 to 0.84 mm (1 to 12 pixels) and 16 GLCM gray levels was set. The highest ROC performance value of AUC=0.77 [95% confidence intervals: 0.71-0.83] was obtained at three specific instances: the default instance, upper ROI window equal to 17.92 mm (256 pixels2), and gray levels set to 128. The texture feature of sum average was chosen as a statistically significant (p<0.05) predictor and associated with higher odds of FP recall for 12 out of 14 total instances.

Optimized ultrasonic assisted extraction-dispersive liquid-liquid microextraction coupled with gas chromatography for determination of essential oil of Oliveria decumbens Vent.

PubMed

Sereshti, Hassan; Izadmanesh, Yahya; Samadi, Soheila

2011-07-22

Ultrasonic assisted extraction-dispersive liquid-liquid microextraction (UAE-DLLME) coupled with gas chromatography (GC) was applied for extraction and determination of essential oil constituents of the plant Oliveria decumbens Vent. Scanning electron microscopy (SEM) was used to see the effect of ultrasonic radiation on the extraction efficiency. By comparison with hydrodistillation, UAE-DLLME is fast, low cost, simple, efficient and consuming small amount of plant materials (∼1.0 g). The effects of various parameters such as temperature, ultrasonication time, volume of disperser and extraction solvents were investigated by a full factorial design to identify significant variables and their interactions. The results demonstrated that temperature and ultrasonication time had no considerable effect on the results. In the next step, a central composite design (CCD) was performed to obtain the optimum levels of significant parameters. The obtained optimal conditions were: 0.45 mL for disperser solvent (acetonitrile) and 94.84 μL for extraction solvent (chlorobenzene). The limits of detection (LODs), linear dynamic range and determination coefficients (R(2)) were 0.2-29 ng mL(-1), 1-2100 ng mL(-1) and 0.995-0.998, respectively. The main components of the essential oil were: thymol (47.06%), carvacrol (23.31%), gamma-terpinene (18.94%), p-cymene (8.71%), limonene (0.76%) and myristicin (0.63%). Copyright © 2011 Elsevier B.V. All rights reserved.

[Optimization of vacuum belt drying process of Gardeniae Fructus in Reduning injection by Box-Behnken design-response surface methodology].

PubMed

Huang, Dao-sheng; Shi, Wei; Han, Lei; Sun, Ke; Chen, Guang-bo; Wu Jian-xiong; Xu, Gui-hong; Bi, Yu-an; Wang, Zhen-zhong; Xiao, Wei

2015-06-01

To optimize the belt drying process conditions optimization of Gardeniae Fructus extract from Reduning injection by Box-Behnken design-response surface methodology, on the basis of single factor experiment, a three-factor and three-level Box-Behnken experimental design was employed to optimize the drying technology of Gardeniae Fructus extract from Reduning injection. With drying temperature, drying time, feeding speed as independent variables and the content of geniposide as dependent variable, the experimental data were fitted to a second order polynomial equation, establishing the mathematical relationship between the content of geniposide and respective variables. With the experimental data analyzed by Design-Expert 8. 0. 6, the optimal drying parameter was as follows: the drying temperature was 98.5 degrees C , the drying time was 89 min, the feeding speed was 99.8 r x min(-1). Three verification experiments were taked under this technology and the measured average content of geniposide was 564. 108 mg x g(-1), which was close to the model prediction: 563. 307 mg x g(-1). According to the verification test, the Gardeniae Fructus belt drying process is steady and feasible. So single factor experiments combined with response surface method (RSM) could be used to optimize the drying technology of Reduning injection Gardenia extract.

Comparison of supercritical fluid extraction and ultrasound-assisted extraction of fatty acids from quince (Cydonia oblonga Miller) seed using response surface methodology and central composite design.

PubMed

Daneshvand, Behnaz; Ara, Katayoun Mahdavi; Raofie, Farhad

2012-08-24

Fatty acids of Cydonia oblonga Miller cultivated in Iran were obtained by supercritical (carbon dioxide) extraction and ultrasound-assisted extraction methods. The oils were analyzed by capillary gas chromatography using mass spectrometric detections. The compounds were identified according to their retention indices and mass spectra (EI, 70eV). The experimental parameters of SFE such as pressure, temperature, modifier volume, static and dynamic extraction time were optimized using a Central Composite Design (CCD) after a 2(5) factorial design. Pressure and dynamic extraction time had significant effect on the extraction yield, while the other factors (temperature, static extraction time and modifier volume) were not identified as significant factors under the selected conditions. The results of chemometrics analysis showed the highest yield for SFE (24.32%), which was obtained at a pressure of 353bar, temperature of 35°C, modifier (methanol) volume of 150μL, and static and dynamic extraction times of 10 and 60min, respectively. Ultrasound-assisted extraction (UAE) of Fatty acids from C. oblonga Miller was optimized, using a rotatable central composite design. The optimum conditions were as follows: solvent (n-hexane) volume, 22mL; extraction time, 30min; and extraction temperature, 55°C. This resulted in a maximum oil recovery of 19.5%. The extracts with higher yield from both methods were subjected to transesterification and GC-MS analysis. The results show that the oil obtained by SFE with the optimal operating conditions allowed a fatty acid composition similar to the oil obtained by UAE in optimum condition and no significant differences were found. The major components of oil extract were Linoleic, Palmitic, Oleic, Stearic and Eicosanoic acids. Copyright © 2012 Elsevier B.V. All rights reserved.

Statistical modeling of ecosystem respiration using eddy covariance data: Maximum likelihood parameter estimation, and Monte Carlo simulation of model and parameter uncertainty, applied to three simple models

Treesearch

Andrew D. Richardson; David Y. Hollinger; David Y. Hollinger

2005-01-01

Whether the goal is to fill gaps in the flux record, or to extract physiological parameters from eddy covariance data, researchers are frequently interested in fitting simple models of ecosystem physiology to measured data. Presently, there is no consensus on the best models to use, or the ideal optimization criteria. We demonstrate that, given our estimates of the...

Simultaneous optimization of the ultrasound-assisted extraction for phenolic compounds content and antioxidant activity of Lycium ruthenicum Murr. fruit using response surface methodology.

PubMed

Chen, Shasha; Zeng, Zhi; Hu, Na; Bai, Bo; Wang, Honglun; Suo, Yourui

2018-03-01

Lycium ruthenicum Murr. (LR) is a functional food that plays an important role in anti-oxidation due to its high level of phenolic compounds. This study aims to optimize ultrasound-assisted extraction (UAE) of phenolic compounds and antioxidant activities of obtained extracts from LR using response surface methodology (RSM). A four-factor-three-level Box-Behnken design (BBD) was employed to discuss the following extracting parameters: extraction time (X 1 ), ultrasonic power (X 2 ), solvent to sample ratio (X 3 ) and solvent concentration (X 4 ). The analysis of variance (ANOVA) results revealed that the solvent to sample ratio had a significant influence on all responses, while the extraction time had no statistically significant effect on phenolic compounds. The optimum values of the combination of phenolic compounds and antioxidant activities were obtained for X 1 =30min, X 2 =100W, X 3 =40mL/g, and X 4 =33% (v/v). Five phenolic acids, including chlorogenic acid, caffeic acid, syringic acid, p-coumaric acid and ferulic acid, were analyzed by HPLC. Our results indicated that optimization extraction is vital for the quantification of phenolic compounds and antioxidant activity in LR, which may be contributed to large-scale industrial applications and future pharmacological activities research. Copyright © 2017 Elsevier Ltd. All rights reserved.

Automatic Parametrization of Somatosensory Evoked Potentials With Chirp Modeling.

PubMed

Vayrynen, Eero; Noponen, Kai; Vipin, Ashwati; Thow, X Y; Al-Nashash, Hasan; Kortelainen, Jukka; All, Angelo

2016-09-01

In this paper, an approach using polynomial phase chirp signals to model somatosensory evoked potentials (SEPs) is proposed. SEP waveforms are assumed as impulses undergoing group velocity dispersion while propagating along a multipath neural connection. Mathematical analysis of pulse dispersion resulting in chirp signals is performed. An automatic parameterization of SEPs is proposed using chirp models. A Particle Swarm Optimization algorithm is used to optimize the model parameters. Features describing the latencies and amplitudes of SEPs are automatically derived. A rat model is then used to evaluate the automatic parameterization of SEPs in two experimental cases, i.e., anesthesia level and spinal cord injury (SCI). Experimental results show that chirp-based model parameters and the derived SEP features are significant in describing both anesthesia level and SCI changes. The proposed automatic optimization based approach for extracting chirp parameters offers potential for detailed SEP analysis in future studies. The method implementation in Matlab technical computing language is provided online.

Micro-matrix solid-phase dispersion coupled with MEEKC for quantitative analysis of lignans in Schisandrae Chinensis Fructus using molecular sieve TS-1 as a sorbent.

PubMed

Chu, Chu; Wei, Mengmeng; Wang, Shan; Zheng, Liqiong; He, Zheng; Cao, Jun; Yan, Jizhong

2017-09-15

A simple and effective method was developed for determining lignans in Schisandrae Chinensis Fructus by using a micro-matrix solid phase dispersion (MSPD) technique coupled with microemulsion electrokinetic chromatography (MEEKC). Molecular sieve, TS-1, was applied as a solid supporting material in micro MSPD extraction for the first time. Parameters that affect extraction efficiency, such as type of dispersant, mass ratio of the sample to the dispersant, grinding time, elution solvent and volume were optimized. The optimal extraction conditions involve dispersing 25mg of powdered Schisandrae samples with 50mg of TS-1 by a mortar and pestle. A grinding time of 150s was adopted. The blend was then transferred to a solid-phase extraction cartridge and the target analytes were eluted with 500μL of methanol. Moreover, several parameters affecting MEEKC separation were studied, including the type of oil, SDS concentration, type and concentration of cosurfactant, and concentration of organic modifier. A satisfactory linearity (R>0.9998) was obtained, and the calculated limits of quantitation were less than 2.77μg/mL. Finally, the micro MSPD-MEEKC method was successfully applied to the analysis of lignans in complex Schisandrae fructus samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Method for Face-Emotion Retrieval Using A Cartoon Emotional Expression Approach

NASA Astrophysics Data System (ADS)

Kostov, Vlaho; Yanagisawa, Hideyoshi; Johansson, Martin; Fukuda, Shuichi

A simple method for extracting emotion from a human face, as a form of non-verbal communication, was developed to cope with and optimize mobile communication in a globalized and diversified society. A cartoon face based model was developed and used to evaluate emotional content of real faces. After a pilot survey, basic rules were defined and student subjects were asked to express emotion using the cartoon face. Their face samples were then analyzed using principal component analysis and the Mahalanobis distance method. Feature parameters considered as having relations with emotions were extracted and new cartoon faces (based on these parameters) were generated. The subjects evaluated emotion of these cartoon faces again and we confirmed these parameters were suitable. To confirm how these parameters could be applied to real faces, we asked subjects to express the same emotions which were then captured electronically. Simple image processing techniques were also developed to extract these features from real faces and we then compared them with the cartoon face parameters. It is demonstrated via the cartoon face that we are able to express the emotions from very small amounts of information. As a result, real and cartoon faces correspond to each other. It is also shown that emotion could be extracted from still and dynamic real face images using these cartoon-based features.

Deterministic Computer-Controlled Polishing Process for High-Energy X-Ray Optics

NASA Technical Reports Server (NTRS)

Khan, Gufran S.; Gubarev, Mikhail; Speegle, Chet; Ramsey, Brian

2010-01-01

A deterministic computer-controlled polishing process for large X-ray mirror mandrels is presented. Using tool s influence function and material removal rate extracted from polishing experiments, design considerations of polishing laps and optimized operating parameters are discussed

Decomposition Techniques for Icesat/glas Full-Waveform Data

NASA Astrophysics Data System (ADS)

Liu, Z.; Gao, X.; Li, G.; Chen, J.

2018-04-01

The geoscience laser altimeter system (GLAS) on the board Ice, Cloud, and land Elevation Satellite (ICESat), is the first long-duration space borne full-waveform LiDAR for measuring the topography of the ice shelf and temporal variation, cloud and atmospheric characteristics. In order to extract the characteristic parameters of the waveform, the key step is to process the full waveform data. In this paper, the modified waveform decomposition method is proposed to extract the echo components from full-waveform. First, the initial parameter estimation is implemented through data preprocessing and waveform detection. Next, the waveform fitting is demonstrated using the Levenberg-Marquard (LM) optimization method. The results show that the modified waveform decomposition method can effectively extract the overlapped echo components and missing echo components compared with the results from GLA14 product. The echo components can also be extracted from the complex waveforms.

Electro-driven extraction of polar compounds using agarose gel as a new membrane: Determination of amino acids in fruit juice and human plasma samples.

PubMed

Sedehi, Samira; Tabani, Hadi; Nojavan, Saeed

2018-03-01

In this work, polypropylene hollow fiber was replaced by agarose gel in conventional electro membrane extraction (EME) to develop a novel approach. The proposed EME method was then employed to extract two amino acids (tyrosine and phenylalanine) as model polar analytes, followed by HPLC-UV. The method showed acceptable results under optimized conditions. This green methodology outperformed conventional EME, and required neither organic solvents nor carriers. The effective parameters such as the pH values of the acceptor and the donor solutions, the thickness and pH of the gel, the extraction voltage, the stirring rate, and the extraction time were optimized. Under the optimized conditions (acceptor solution pH: 1.5; donor solution pH: 2.5; agarose gel thickness: 7mm; agarose gel pH: 1.5; stirring rate of the sample solution: 1000rpm; extraction potential: 40V; and extraction time: 15min), the limits of detection and quantification were 7.5ngmL -1 and 25ngmL -1 , respectively. The extraction recoveries were between 56.6% and 85.0%, and the calibration curves were linear with correlation coefficients above 0.996 over a concentration range of 25.0-1000.0ngmL -1 for both amino acids. The intra- and inter-day precisions were in the range of 5.5-12.5%, and relative errors were smaller than 12.0%. Finally, the optimized method was successfully applied to preconcentrate, clean up, and quantify amino acids in watermelon and grapefruit juices as well as a plasma sample, and acceptable relative recoveries in the range of 53.9-84.0% were obtained. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultrasound assisted extraction combined with dispersive liquid-liquid microextraction (US-DLLME)-a fast new approach to measure phthalate metabolites in nails.

PubMed

Alves, Andreia; Vanermen, Guido; Covaci, Adrian; Voorspoels, Stefan

2016-09-01

A new, fast, and environmentally friendly method based on ultrasound assisted extraction combined with dispersive liquid-liquid microextraction (US-DLLME) was developed and optimized for assessing the levels of seven phthalate metabolites (including the mono(ethyl hexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (5-OH-MEHP), mono(2-ethyl-5-oxohexyl) phthalate (5-oxo-MEHP), mono-n-butyl phthalate (MnBP), mono-isobutyl phthalate (MiBP), monoethyl phthalate (MEP), and mono-benzyl phthalate (MBzP)) in human nails by UPLC-MS/MS. The optimization of the US-DLLME method was performed using a Taguchi combinatorial design (L9 array). Several parameters such as extraction solvent, solvent volume, extraction time, acid, acid concentration, and vortex time were studied. The optimal extraction conditions achieved were 180 μL of trichloroethylene (extraction solvent), 2 mL trifluoroacetic acid in methanol (2 M), 2 h extraction and 3 min vortex time. The optimized method had a good precision (6-17 %). The accuracy ranged from 79 to 108 % and the limit of method quantification (LOQm) was below 14 ng/g for all compounds. The developed US-DLLME method was applied to determine the target metabolites in 10 Belgian individuals. Levels of the analytes measured in nails ranged between <12 and 7982 ng/g. The MEHP, MBP isomers, and MEP were the major metabolites and detected in every sample. Miniaturization (low volumes of organic solvents used), low costs, speed, and simplicity are the main advantages of this US-DLLME based method. Graphical Abstract Extraction and phase separation of the US-DLLME procedure.

Investigating the feasibility of using partial least squares as a method of extracting salient information for the evaluation of digital breast tomosynthesis

NASA Astrophysics Data System (ADS)

Zhang, George Z.; Myers, Kyle J.; Park, Subok

2013-03-01

Digital breast tomosynthesis (DBT) has shown promise for improving the detection of breast cancer, but it has not yet been fully optimized due to a large space of system parameters to explore. A task-based statistical approach1 is a rigorous method for evaluating and optimizing this promising imaging technique with the use of optimal observers such as the Hotelling observer (HO). However, the high data dimensionality found in DBT has been the bottleneck for the use of a task-based approach in DBT evaluation. To reduce data dimensionality while extracting salient information for performing a given task, efficient channels have to be used for the HO. In the past few years, 2D Laguerre-Gauss (LG) channels, which are a complete basis for stationary backgrounds and rotationally symmetric signals, have been utilized for DBT evaluation2, 3 . But since background and signal statistics from DBT data are neither stationary nor rotationally symmetric, LG channels may not be efficient in providing reliable performance trends as a function of system parameters. Recently, partial least squares (PLS) has been shown to generate efficient channels for the Hotelling observer in detection tasks involving random backgrounds and signals.4 In this study, we investigate the use of PLS as a method for extracting salient information from DBT in order to better evaluate such systems.

Ultrathin-shell boron nitride hollow spheres as sorbent for dispersive solid-phase extraction of polychlorinated biphenyls from environmental water samples.

PubMed

Fu, Meizhen; Xing, Hanzhu; Chen, Xiangfeng; Chen, Fan; Wu, Chi-Man Lawrence; Zhao, Rusong; Cheng, Chuange

2014-11-21

Boron nitride hollow spheres with ultrathin-shells were synthesized and used as sorbents for dispersive solid-phase extraction of aromatic pollutants at trace levels from environmental water samples. Polychlorinated biphenyls (PCBs) were selected as target compounds. Sample quantification and detection were performed by gas chromatography-tandem mass spectrometry. Extraction parameters influencing the extraction efficiency were optimized through response surface methodology using the Box-Behnken design. The proposed method achieved good linearity within the concentration range of 0.15-250 ng L(-1) PCBs, low limits of detection (0.04-0.09 ng L(-1), S/N=3:1), good repeatability of the extractions (relative standard deviation, <12%, n=6), and satisfactory recoveries between 84.9% and 101.0% under optimal conditions. Real environmental samples collected from rivers, local lakes, rain and spring waters were analyzed using the developed method. Results demonstrated that the hexagonal boron nitride-based material has significant potential as a sorbent for organic pollutant extraction from environmental water samples. Copyright © 2014 Elsevier B.V. All rights reserved.

[Research of the essential oil of Plumeria rubra var. actifolia from Laos by supercritical carbon dioxide extraction].

PubMed

Xiao, Xin-Yu; Cui, Long-Hai; Zhou, Xin-Xin; Wu, Yan; Ge, Fa-Huan

2011-05-01

The orthogonal test and the supercritical carbon dioxide fluid extraction were used for optimizing the extraction of the essential oil from Plumeria rubra var. actifolia for the first time. Compared with the steam distillation, the optimal operation parameter of extraction was as follows: extraction pressure 25 MPa, extraction temperature 45 degrees C; separator I pressure 12 MPa, separator I temperature 55 degrees C; separator II pressure 6 MPa, separator II temperature 30 degrees C. Under this condition the yield of the essential oil was 5.8927%. The components were separated and identified by GC-MS. 53 components of Plumeria rubra var. actifolia measured by SFE method were identified and determined by normalization method. The main components were 1, 6, 10-dodecatrien-3-ol, 3, 7, 11-trimethyl, benzoic acid, 2-hydroxy-, phenylmethyl ester, 1, 2-benzenedicarboxylic acid, bis(2-methylpropyl) ester,etc.. 1, 2-Benzenedicarboxylic acid, bis (2-methylpropyl) este. took up 66.11% of the total amount, and there was much difference of the results from SD method.

Flash Extraction and Physicochemical Characterization of Oil from Elaeagnus mollis Diels Seeds.

PubMed

Kan, Lina; Wang, Lin; Ding, Qingzhen; Wu, Yanwen; Ouyang, Jie

2017-04-03

A flash extraction method was used to isolate Elaeagnus mollis oil (EMO). The optimal extraction parameters, sample/solvent ratio and extraction temperature, were determined to be 1:10 (g/mL) and 40°C, respectively. Especially, the extraction yield reached 49.30% when the extraction time was as short as 2 min. No obvious difference was observed in fatty acid composition, iodine value, saponification number, total phenolic content and tocopherol content between flash-extracted EMO and Soxhlet-extracted EMO, but their physicochemical values were lower than those of cold-pressed EMO. Cold-pressed EMO had higher oxidation stability, DPPH (1-diphenyl-2-picrylhydrazyl) and hydroxyl radical-scavenging activities than flash-extracted EMO and Soxlet extracted EMO. The flash extraction is demonstrated to be an alternative, efficient method for the vegetable oil production.

Intensification of extraction of curcumin from Curcuma amada using ultrasound assisted approach: Effect of different operating parameters.

PubMed

Shirsath, S R; Sable, S S; Gaikwad, S G; Sonawane, S H; Saini, D R; Gogate, P R

2017-09-01

Curcumin, a dietary phytochemical, has been extracted from rhizomes of Curcuma amada using ultrasound assisted extraction (UAE) and the results compared with the conventional extraction approach to establish the process intensification benefits. The effect of operating parameters such as type of solvent, extraction time, extraction temperature, solid to solvent ratio, particle size and ultrasonic power on the extraction yield have been investigated in details for the approach UAE. The maximum extraction yield as 72% was obtained in 1h under optimized conditions of 35°C temperature, solid to solvent ratio of 1:25, particle size of 0.09mm, ultrasonic power of 250W and ultrasound frequency of 22kHz with ethanol as the solvent. The obtained yield was significantly higher as compared to the batch extraction where only about 62% yield was achieved in 8h of treatment. Peleg's model was used to describe the kinetics of UAE and the model showed a good agreement with the experimental results. Overall, ultrasound has been established to be a green process for extraction of curcumin with benefits of reduction in time as compared to batch extraction and the operating temperature as compared to Soxhlet extraction. Copyright © 2017. Published by Elsevier B.V.

Extraction of Illegal Dyes from Red Chili Peppers with Cholinium-Based Deep Eutectic Solvents

PubMed Central

Zhu, Shuqiang; Zhu, Xinyue; Su, Along

2017-01-01

Deep eutectic solvents (DESs) as a new kind of green solvents have been used to extract bioactive compounds but there are few applications in extracting chrysoidine dyes. In this study, we developed an ultrasonic-assisted extraction method with choline chloride/hydrogen bond donor (ChCl/HBD) DES for the extraction of chrysoidine G (COG), astrazon orange G (AOG), and astrazon orange R (AOR) in food samples. Some experimental parameters, such as extraction time, raw material/solvent ratio, and temperature, were evaluated and optimized as follows: the ratio of ChCl/HBD, 1 : 2 (v/v); the ratio of sample/DES, 1 : 10 (g/mL); extraction time, 20 min; extraction temperature, 50°C. Under the optimized conditions, the limits of detection (μg/mL) were 0.10 for COG and 0.06 for AOG and AOR. The relative standard deviations were in the range of 1.2–2.1%. The recoveries of the three dyes were in the range of 80.2–105.0%. By comparing with other commonly used solvents for extracting chrysoidine dyes, the advantages of DESs proved them to be potential extraction solvents for chrysoidine G, astrazon orange G, and astrazon orange R in foods. PMID:28831327

A modified temporal criterion to meta-optimize the extended Kalman filter for land cover classification of remotely sensed time series

NASA Astrophysics Data System (ADS)

Salmon, B. P.; Kleynhans, W.; Olivier, J. C.; van den Bergh, F.; Wessels, K. J.

2018-05-01

Humans are transforming land cover at an ever-increasing rate. Accurate geographical maps on land cover, especially rural and urban settlements are essential to planning sustainable development. Time series extracted from MODerate resolution Imaging Spectroradiometer (MODIS) land surface reflectance products have been used to differentiate land cover classes by analyzing the seasonal patterns in reflectance values. The proper fitting of a parametric model to these time series usually requires several adjustments to the regression method. To reduce the workload, a global setting of parameters is done to the regression method for a geographical area. In this work we have modified a meta-optimization approach to setting a regression method to extract the parameters on a per time series basis. The standard deviation of the model parameters and magnitude of residuals are used as scoring function. We successfully fitted a triply modulated model to the seasonal patterns of our study area using a non-linear extended Kalman filter (EKF). The approach uses temporal information which significantly reduces the processing time and storage requirements to process each time series. It also derives reliability metrics for each time series individually. The features extracted using the proposed method are classified with a support vector machine and the performance of the method is compared to the original approach on our ground truth data.

Simulation for light extraction efficiency of OLEDs with spheroidal microlenses in hexagonal array

NASA Astrophysics Data System (ADS)

Bae, Hyungchul; Kim, Jun Soo; Hong, Chinsoo

2018-05-01

A theoretical model based on ray optics is used to simulate the optical performance of organic light-emitting diodes (OLEDs) with spheroidal microlens arrays (MLAs) in a hexagonal array configuration using the Monte Carlo method. In simulations, ray tracing was performed until 20 reflections occurred from the metal cathode, with 10 consecutive reflections permitted in a single lens pattern. The parameters describing the shape and array of the lens pattern of a MLA are its radius, height, contact angle, and fill factor (FF). Many previous results on how these parameters affect light extraction efficiency (LEE) are inconsistent. In this paper, these contradictory results are discussed and explained by introducing a new parameter. To examine light extraction from an OLED through a MLA, the LEE enhancement is studied considering the effect of absorption by indium tin oxide during multiple reflections from the metal cathode. The device size where LEE enhancement is unchanged with changing lens pattern was identified for a fixed FF; under this condition, the optimal LEE enhancement, 84%, can be obtained using an OLED with a close-packed spheroidal MLA. An ideal maximum LEE enhancement of 120% was achieved with a device with an infinite-sized MLA. The angular intensity distribution of light emitted through a MLA is considered in addition to LEE enhancement for an optimized MLA.

Front-end simulation of injector for terawatt accumulator.

PubMed

Kropachev, G N; Balabin, A I; Kolomiets, A A; Kulevoy, T V; Pershin, V I; Shumshurov, A V

2008-02-01

A terawatt accumulator (TWAC) accelerator/storage ring complex with the laser ion source is in progress at ITEP. The new injector I4 based on the radio frequency quadrupole (RFQ) and interdigital H-mode (IH) linear accelerator is under construction. The front end of the new TWAC injector consists of a laser ion source, an extraction system, and a low energy beam transport (LEBT). The KOBRA3-INP was used for the simulation and optimization of the ion source extraction system. The optimization parameter is the maximum brightness of the beam generated by the laser ion source. Also the KOBRA3-INP code was used for LEBT investigation. The LEBT based on electrostatic grid lenses is chosen for injector I4. The results of the extraction system and LEBT investigations for ion beam matching with RFQ are presented.

Integrative image segmentation optimization and machine learning approach for high quality land-use and land-cover mapping using multisource remote sensing data

NASA Astrophysics Data System (ADS)

Gibril, Mohamed Barakat A.; Idrees, Mohammed Oludare; Yao, Kouame; Shafri, Helmi Zulhaidi Mohd

2018-01-01

The growing use of optimization for geographic object-based image analysis and the possibility to derive a wide range of information about the image in textual form makes machine learning (data mining) a versatile tool for information extraction from multiple data sources. This paper presents application of data mining for land-cover classification by fusing SPOT-6, RADARSAT-2, and derived dataset. First, the images and other derived indices (normalized difference vegetation index, normalized difference water index, and soil adjusted vegetation index) were combined and subjected to segmentation process with optimal segmentation parameters obtained using combination of spatial and Taguchi statistical optimization. The image objects, which carry all the attributes of the input datasets, were extracted and related to the target land-cover classes through data mining algorithms (decision tree) for classification. To evaluate the performance, the result was compared with two nonparametric classifiers: support vector machine (SVM) and random forest (RF). Furthermore, the decision tree classification result was evaluated against six unoptimized trials segmented using arbitrary parameter combinations. The result shows that the optimized process produces better land-use land-cover classification with overall classification accuracy of 91.79%, 87.25%, and 88.69% for SVM and RF, respectively, while the results of the six unoptimized classifications yield overall accuracy between 84.44% and 88.08%. Higher accuracy of the optimized data mining classification approach compared to the unoptimized results indicates that the optimization process has significant impact on the classification quality.

Matrix effect and optimization of LC-MSn determination of trachylobane-360 in mice blood.

PubMed

Pita, João Carlos Lima Rodrigues; Gomes, Isis Fernandes; Dos Santos, Socrates Golzio; Tavares, Josean Fechine; da Silva, Marcelo Sobral; Diniz, Margareth de Fátima Formiga Melo; Sobral, Marianna Vieira

2014-11-01

Xylopia langsdorffiana A. St.-Hil. & Tul. (Annonaceae) is popularly known as "pimenteira-da-terra". Various constituents have been isolated from this species, including diterpenes, such as 8(17), 12E, 14-labdatrien-18-oic acid, ent-atisan-7α, 16α-diol (xylodiol), ent-7α-hydroxytrachyloban-18-oic acid (trachylobane-318) and ent-7α-acetoxytrachyloban-18-oic acid, a crystalline solid with a molecular weight of 360 and molecular formula of C22H32O4 (trachylobane-360). When administered intraperitoneally to mice, trachylobane-360 (T-360) significantly inhibits growth of the solid tumor sarcoma 180 transplanted in mice, without causing alterations in biochemical, hematological and histopathological parameters that are frequently associated with the clinical use of antineoplastic. Furthermore, this diterpene blocks voltage-dependent calcium channels (Cav), showing spasmolytic activity. The present study shows that variables such as extraction solvent (methanol, acetonitrile and chloroform), centrifugation force (1000, 7000 and 14,000×g), and centrifugation time (5, 15 and 25min), are important in the liquid-liquid extraction of T-360 from male Swiss mice blood in HPLC-MSn studies. The study confirms matrix influence on recovery and detection of T-360. The recovery for T-360 was 37.02% using chloroform as better extractor solvent, while centrifuged at 14,000×g for 15min demonstrated the importance of the parameters chosen for the extraction/recovery process of analyte. The effect of mice blood matrix for T-360 was -51.23%. This method was optimized by repeating the extraction procedure and acidification of samples. These conditions were essential in increasing recovery (49.47%) by decreasing the matrix effect (-37.60%). The efficiency of the process, after optimization with two extractions and acidification, increased by 14.19% when compared to the initial method, from 18.05% to 32.24%. According to Marchi et al. (2010), the matrix effect does not necessarily need to be reduced or eliminated, but it does need to be identified and quantified. Therefore, these findings are essential for the subsequent evaluation of the pharmacokinetic parameters of this promising natural product. Copyright © 2014 Elsevier B.V. All rights reserved.

Integrating fuzzy object based image analysis and ant colony optimization for road extraction from remotely sensed images

NASA Astrophysics Data System (ADS)

Maboudi, Mehdi; Amini, Jalal; Malihi, Shirin; Hahn, Michael

2018-04-01

Updated road network as a crucial part of the transportation database plays an important role in various applications. Thus, increasing the automation of the road extraction approaches from remote sensing images has been the subject of extensive research. In this paper, we propose an object based road extraction approach from very high resolution satellite images. Based on the object based image analysis, our approach incorporates various spatial, spectral, and textural objects' descriptors, the capabilities of the fuzzy logic system for handling the uncertainties in road modelling, and the effectiveness and suitability of ant colony algorithm for optimization of network related problems. Four VHR optical satellite images which are acquired by Worldview-2 and IKONOS satellites are used in order to evaluate the proposed approach. Evaluation of the extracted road networks shows that the average completeness, correctness, and quality of the results can reach 89%, 93% and 83% respectively, indicating that the proposed approach is applicable for urban road extraction. We also analyzed the sensitivity of our algorithm to different ant colony optimization parameter values. Comparison of the achieved results with the results of four state-of-the-art algorithms and quantifying the robustness of the fuzzy rule set demonstrate that the proposed approach is both efficient and transferable to other comparable images.

Trace analysis of selected hormones and sterols in river sediments by liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry.

PubMed

Matić, Ivana; Grujić, Svetlana; Jauković, Zorica; Laušević, Mila

2014-10-17

In this paper, development and optimization of new LC-MS method for determination of twenty selected hormones, human/animal and plant sterols in river sediments were described. Sediment samples were prepared using ultrasonic extraction and clean up with silica gel/anhydrous sodium sulphate cartridge. Extracts were analyzed by liquid chromatography-linear ion trap-tandem mass spectrometry, with atmospheric pressure chemical ionization. The optimized extraction parameters were extraction solvent (methanol), weight of the sediment (2 g) and time of ultrasonic extraction (3× 10 min). Successful chromatographic separation of hormones (estriol and estrone, 17α- and 17β-estradiol) and four human/animal sterols (epicoprostanol, coprostanol, α-cholestanol and β-cholestanol) that have identical fragmentation reactions was achieved. The developed and optimized method provided high recoveries (73-118%), low limits of detection (0.8-18 ng g(-1)) and quantification (2.5-60 ng g(-1)) with the RSDs generally lower than 20%. Applicability of the developed method was confirmed by analysis of six river sediment samples. A widespread occurrence of human/animal and plant sterols was found. The only detected hormone was mestranol in just one sediment sample. Copyright © 2014 Elsevier B.V. All rights reserved.

Headspace single drop microextraction coupled with microwave extraction of essential oil from plant materials.

PubMed

Zhai, Yujuan; Sun, Shuo; Wang, Ziming; Zhang, Yupu; Liu, He; Sun, Ye; Zhang, Hanqi; Yu, Aimin

2011-05-01

Headspace single drop microextraction (HS-SDME) coupled with microwave extraction (ME) was developed and applied to the extraction of the essential oil from dried Syzygium aromaticum (L.) Merr. et Perry and Cuminum cyminum L. The operational parameters, such as microdrop volume, microwave absorption medium (MAM), extraction time, and microwave power were optimized. Ten microliters of decane was used as the microextraction solvent. Ionic liquid and carbonyl iron powder were used as MAM. The extraction time was less than 7 min at the microwave power of 440 W. The proposed method was compared with hydrodistillation (HD). There were no obvious differences in the constituents of essential oils obtained by the two methods.

Stepped MS(All) Relied Transition (SMART): An approach to rapidly determine optimal multiple reaction monitoring mass spectrometry parameters for small molecules.

PubMed

Ye, Hui; Zhu, Lin; Wang, Lin; Liu, Huiying; Zhang, Jun; Wu, Mengqiu; Wang, Guangji; Hao, Haiping

2016-02-11

Multiple reaction monitoring (MRM) is a universal approach for quantitative analysis because of its high specificity and sensitivity. Nevertheless, optimization of MRM parameters remains as a time and labor-intensive task particularly in multiplexed quantitative analysis of small molecules in complex mixtures. In this study, we have developed an approach named Stepped MS(All) Relied Transition (SMART) to predict the optimal MRM parameters of small molecules. SMART requires firstly a rapid and high-throughput analysis of samples using a Stepped MS(All) technique (sMS(All)) on a Q-TOF, which consists of serial MS(All) events acquired from low CE to gradually stepped-up CE values in a cycle. The optimal CE values can then be determined by comparing the extracted ion chromatograms for the ion pairs of interest among serial scans. The SMART-predicted parameters were found to agree well with the parameters optimized on a triple quadrupole from the same vendor using a mixture of standards. The parameters optimized on a triple quadrupole from a different vendor was also employed for comparison, and found to be linearly correlated with the SMART-predicted parameters, suggesting the potential applications of the SMART approach among different instrumental platforms. This approach was further validated by applying to simultaneous quantification of 31 herbal components in the plasma of rats treated with a herbal prescription. Because the sMS(All) acquisition can be accomplished in a single run for multiple components independent of standards, the SMART approach are expected to find its wide application in the multiplexed quantitative analysis of complex mixtures. Copyright © 2015 Elsevier B.V. All rights reserved.

Spectral gap optimization of order parameters for sampling complex molecular systems

PubMed Central

Tiwary, Pratyush; Berne, B. J.

2016-01-01

In modern-day simulations of many-body systems, much of the computational complexity is shifted to the identification of slowly changing molecular order parameters called collective variables (CVs) or reaction coordinates. A vast array of enhanced-sampling methods are based on the identification and biasing of these low-dimensional order parameters, whose fluctuations are important in driving rare events of interest. Here, we describe a new algorithm for finding optimal low-dimensional CVs for use in enhanced-sampling biasing methods like umbrella sampling, metadynamics, and related methods, when limited prior static and dynamic information is known about the system, and a much larger set of candidate CVs is specified. The algorithm involves estimating the best combination of these candidate CVs, as quantified by a maximum path entropy estimate of the spectral gap for dynamics viewed as a function of that CV. The algorithm is called spectral gap optimization of order parameters (SGOOP). Through multiple practical examples, we show how this postprocessing procedure can lead to optimization of CV and several orders of magnitude improvement in the convergence of the free energy calculated through metadynamics, essentially giving the ability to extract useful information even from unsuccessful metadynamics runs. PMID:26929365

Dynamic Bayesian wavelet transform: New methodology for extraction of repetitive transients

NASA Astrophysics Data System (ADS)

Wang, Dong; Tsui, Kwok-Leung

2017-05-01

Thanks to some recent research works, dynamic Bayesian wavelet transform as new methodology for extraction of repetitive transients is proposed in this short communication to reveal fault signatures hidden in rotating machine. The main idea of the dynamic Bayesian wavelet transform is to iteratively estimate posterior parameters of wavelet transform via artificial observations and dynamic Bayesian inference. First, a prior wavelet parameter distribution can be established by one of many fast detection algorithms, such as the fast kurtogram, the improved kurtogram, the enhanced kurtogram, the sparsogram, the infogram, continuous wavelet transform, discrete wavelet transform, wavelet packets, multiwavelets, empirical wavelet transform, empirical mode decomposition, local mean decomposition, etc.. Second, artificial observations can be constructed based on one of many metrics, such as kurtosis, the sparsity measurement, entropy, approximate entropy, the smoothness index, a synthesized criterion, etc., which are able to quantify repetitive transients. Finally, given artificial observations, the prior wavelet parameter distribution can be posteriorly updated over iterations by using dynamic Bayesian inference. More importantly, the proposed new methodology can be extended to establish the optimal parameters required by many other signal processing methods for extraction of repetitive transients.

Optimized Kernel Entropy Components.

PubMed

Izquierdo-Verdiguier, Emma; Laparra, Valero; Jenssen, Robert; Gomez-Chova, Luis; Camps-Valls, Gustau

2017-06-01

This brief addresses two main issues of the standard kernel entropy component analysis (KECA) algorithm: the optimization of the kernel decomposition and the optimization of the Gaussian kernel parameter. KECA roughly reduces to a sorting of the importance of kernel eigenvectors by entropy instead of variance, as in the kernel principal components analysis. In this brief, we propose an extension of the KECA method, named optimized KECA (OKECA), that directly extracts the optimal features retaining most of the data entropy by means of compacting the information in very few features (often in just one or two). The proposed method produces features which have higher expressive power. In particular, it is based on the independent component analysis framework, and introduces an extra rotation to the eigen decomposition, which is optimized via gradient-ascent search. This maximum entropy preservation suggests that OKECA features are more efficient than KECA features for density estimation. In addition, a critical issue in both the methods is the selection of the kernel parameter, since it critically affects the resulting performance. Here, we analyze the most common kernel length-scale selection criteria. The results of both the methods are illustrated in different synthetic and real problems. Results show that OKECA returns projections with more expressive power than KECA, the most successful rule for estimating the kernel parameter is based on maximum likelihood, and OKECA is more robust to the selection of the length-scale parameter in kernel density estimation.

A comparison study on microwave-assisted extraction of Artemisia sphaerocephala polysaccharides with conventional method: Molecule structure and antioxidant activities evaluation.

PubMed

Wang, Junlong; Zhang, Ji; Wang, Xiaofang; Zhao, Baotang; Wu, Yiqian; Yao, Jian

2009-12-01

The conventional extraction methods for polysaccharides were time-consuming, laborious and energy-consuming. Microwave-assisted extraction (MAE) technique was employed for the extraction of Artemisia sphaerocephala polysaccharides (ASP), which is a traditional Chinese food. The extracting parameters were optimized by Box-Behnken design. In microwave heating process, a decrease in molecular weight (M(w)) was detected in SEC-LLS measurement. A d(f) value of 2.85 indicated ASP using MAE exhibited as a sphere conformation of branched clusters in aqueous solution. Furthermore, it showed stronger antioxidant activities compared with hot water extraction. The data obtained showed that the molecular weights played a more important role in antioxidant activities.

Microwave-assisted extraction of polysaccharides from Cyphomandra betacea and its biological activities.

PubMed

C, Senthil Kumar; M, Sivakumar; K, Ruckmani

2016-11-01

Response Surface Methodology (RSM) was used to optimize the parameters for microwave-assisted extraction of polysaccharides from Cyphomandra betacea. The results showed a good fit with a second-order polynomial equation that was statistically acceptable at P<0.05. Optimal conditions for the extraction of polysaccharides were: extraction time, 2h; microwave power, 400W; extraction temperature, 60°C; and ratio of raw material to water 1:40 (g/mL). Under the optimized conditions, the yield of polysaccharides was found to be relatively high (about 36.52%). The in vitro biological activities of antioxidant and antitumor were evaluated. The IC 50 value of polysaccharides was found to be 3mg/mL. The percentage of Cell viability was determined by MTT assay. Our results showed that polysaccharides inhibited proliferation of MCF-7 (Breast carcinoma), A549 (Human lung carcinoma) and HepG2 (Liver carcinoma) with an IC 50 of 0.23mg/mL, 0.17mg/mL and 0.62mg/mL respectively after 48h incubation. Polysaccharides were shown to promote apoptosis as seen in the nuclear morphological examination study using acridine orange (AO) and ethidium bromide (EB) staining. This is the first report on the effects of polysaccharides extracted from Cyphomandra betacea which exhibited stronger antioxidant and antitumor activities. Copyright © 2016 Elsevier B.V. All rights reserved.

Rapid extraction of Amomum tsao-ko essential oil and determination of its chemical composition, antioxidant and antimicrobial activities.

PubMed

Cui, Qi; Wang, Li-Tao; Liu, Ju-Zhao; Wang, Hui-Mei; Guo, Na; Gu, Cheng-Bo; Fu, Yu-Jie

2017-09-01

A simple, green and efficient extraction method named modified-solvent free microwave extraction (M-SFME) was employed for the extraction of essential oils (EOs) from Amomun tsao-ko. The process of M-SFME was optimized with the prominent preponderance of such higher extraction yield (1.13%) than those of solvent free microwave extraction (SFME, 0.91%) and hydrodistillation (HD, 0.84%) under the optimal parameters. Thirty-four volatile substances representing 95.4% were identified. The IC 50 values of EOs determined by DPPH radical scavenging activity and β-carotene/linoleic acid bleaching assay were 5.27 and 0.63mg/ml. Furthermore, the EOs exhibited moderate to potent broad-spectrum antimicrobial activity against all tested strains including five gram-positive and two gram-negative bacteria (MIC: 2.94-5.86mg/ml). In general, M-SFME is a potential and desirable alternative for the extraction of EOs from aromatic herbs, and the EOs obtained from A. tsao-ko can be explored as a potent natural antimicrobial and antioxidant preservative ingredient in food industry from the technological and economical points of view. Copyright © 2017 Elsevier B.V. All rights reserved.

Optimization of simultaneous microwave/ultrasonic-assisted extraction of phenolic compounds from walnut flour using response surface methodology.

PubMed

Luo, Yan; Wu, Wanxing; Chen, Dan; Lin, Yuping; Ma, Yage; Chen, Chaoyin; Zhao, Shenglan

2017-12-01

Walnut is a traditional food as well as a traditional medicine recorded in the Chinese Pharmacopoeia; however, the large amounts of walnut flour (WF) generated in walnut oil production have not been well utilized. This study maximized the total polyphenolic yield (TPY) from the walnut flour (WF) by optimizing simultaneous ultrasound/microwave-assisted hydroalcoholic extraction (SUMAE). Response surface methodology was used to optimize the processing parameters for the TPY, including microwave power (20-140 W), ultrasonic power (75-525 W), extraction temperature (25-55 °C), and time (0.5-9.5 min). The polyphenol components were analysed by LC-MS. A second-order polynomial model satisfactorily fit the experimental TPY data (R 2  = 0.9932, P < 0.0001 and R adj 2     = 0.9868). The optimized quick extraction conditions were microwave power 294.38 W, ultrasonic power 93.5 W, temperature 43.38 °C and time 4.33 min, with a maximum TPY of 34.91 mg GAE/g, which was a rapid extraction. The major phenolic components in the WF extracts were glansreginin A, ellagic acid, and gallic acid with peak areas of 22.15%, 14.99% and 10.96%, respectively, which might be used as functional components for health food, cosmetics and medicines. The results indicated that walnut flour, a waste product from the oil industry, was a rich source of polyphenolic compounds and thus could be used as a high-value functional food ingredient.

Extraction of caustic potash from spent tea for biodiesel Production

NASA Astrophysics Data System (ADS)

Sulaiman, Sarina; Faiz Che Fisol, Ahmad; Sharikh, Atikah Mohamed; Noraini Jimat, Dzun; Jamal, Parveen

2018-01-01

Biodiesel is an alternative to non-renewable fossil fuels due to its low gas emission and economical value. This study aims to extract caustic potash (KOH) from spent tea and to optimize the transesterfication process based on parameters such as amount of catalyst, reaction temperature and methanol to oil ratio. The spent tea was first dried at 60°C prior to calcination at 600°C for two hours. Caustic Potash were extracted from the calcined spent tea. The transesterification process was done based on Design of Experiments (DOE) to study the effects of amount of catalyst ranging from 0.5 wt % to 2.5 wt %, reaction temperature from 55°C to 65°C and methanol to oil ratio from 6:1 to 12:1 at a constant agitation rate of 300 rpm for three hours. The calcined spent tea produced was recorded the highest at 54.3 wt % and the extracted catalyst was 2.4 wt %. The optimized biodiesel yield recorded was 56.95% at the optimal conditions of 2.5 wt % amount of catalyst, 65°C reaction temperature and 9:1 methanol to oil ratio.

Optimization of matrix solid-phase dispersion for the rapid determination of salicylate and benzophenone-type UV absorbing substances in marketed fish.

PubMed

Tsai, Dung-Ying; Chen, Chien-Liang; Ding, Wang-Hsien

2014-07-01

A simple and effective method for the rapid determination of five salicylate and benzophenone-type UV absorbing substances in marketed fish is described. The method involves the use of matrix solid-phase dispersion (MSPD) prior to their determination by on-line silylation gas chromatography tandem mass spectrometry (GC-MS/MS). The parameters that affect the extraction efficiency were optimized using a Box-Behnken design method. The optimal extraction conditions involved dispersing 0.5g of freeze-dried powdered fish with 1.0g of Florisil using a mortar and pestle. This blend was then transferred to a solid-phase extraction (SPE) cartridge containing 1.0g of octadecyl bonded silica (C18), as the clean-up co-sorbent. The target analytes were then eluted with 7mL of acetonitrile. The extract was derivatized on-line in the GC injection-port by reaction with a trimethylsilylating (TMS) reagent. The TMS-derivatives were then identified and quantitated by GC-MS/MS. The limits of quantitation (LOQs) were less than 0.1ng/g. Copyright © 2014 Elsevier Ltd. All rights reserved.

Optimal Fermentation Conditions of Hyaluronidase Inhibition Activity on Asparagus cochinchinensis Merrill by Weissella cibaria.

PubMed

Kim, Minji; Kim, Won-Baek; Koo, Kyoung Yoon; Kim, Bo Ram; Kim, Doohyun; Lee, Seoyoun; Son, Hong Joo; Hwang, Dae Youn; Kim, Dong Seob; Lee, Chung Yeoul; Lee, Heeseob

2017-04-28

This study was conducted to evaluate the hyaluronidase (HAase) inhibition activity of Asparagus cochinchinesis (AC) extracts following fermentation by Weissella cibaria through response surface methodology. To optimize the HAase inhibition activity, a central composite design was introduced based on four variables: the concentration of AC extract ( X 1 : 1-5%), amount of starter culture ( X 2 : 1-5%), pH ( X 3 : 4-8), and fermentation time ( X 4 : 0-10 days). The experimental data were fitted to quadratic regression equations, the accuracy of the equations was analyzed by ANOVA, and the regression coefficients for the surface quadratic model of HAase inhibition activity in the fermented AC extract were estimated by the F test and the corresponding p values. The HAase inhibition activity indicated that fermentation time was most significant among the parameters within the conditions tested. To validate the model, two different conditions among those generated by the Design Expert program were selected. Under both conditions, predicted and experimental data agreed well. Moreover, the content of protodioscin (a well-known compound related to anti-inflammation activity) was elevated after fermentation of the AC extract at the optimized fermentation condition.

Ionic liquid-based ultrasonic/microwave-assisted extraction combined with UPLC-MS-MS for the determination of tannins in Galla chinensis.

PubMed

Lu, Chunxia; Wang, Hongxin; Lv, Wenping; Ma, Chaoyang; Lou, Zaixiang; Xie, Jun; Liu, Bo

2012-01-01

Ionic liquid was used as extraction solvents and applied to the extraction of tannins from Galla chinensis in the simultaneous ultrasonic- and microwave-assisted extraction (UMAE) technique. Several parameters of UMAE were optimised, and the results were compared with of the conventional extraction techniques. Under optimal conditions, the content of tannins was 630.2 ± 12.1 mg g⁻¹. Compared with the conventional heat-reflux extraction, maceration extraction, regular ultrasound- and microwave-assisted extraction, the proposed approach exhibited higher efficiency (11.7-22.0% enhanced) and shorter extraction time (from 6 h to 1 min). The tannins were then identified by ultraperformance liquid chromatography tandem mass spectrometry. This study suggests that ionic liquid-based UMAE is an efficient, rapid, simple and green sample preparation technique.

Microwave-assisted extraction of cyclotides from Viola ignobilis.

PubMed

Farhadpour, Mohsen; Hashempour, Hossein; Talebpour, Zahra; A-Bagheri, Nazanin; Shushtarian, Mozhgan Sadat; Gruber, Christian W; Ghassempour, Alireza

2016-03-15

Cyclotides are an interesting family of circular plant peptides. Their unique three-dimensional structure, comprising a head-to-tail circular backbone chain and three disulfide bonds, confers them stability against thermal, chemical, and enzymatic degradation. Their unique stability under extreme conditions creates an idea about the possibility of using harsh extraction methods such as microwave-assisted extraction (MAE) without affecting their structures. MAE has been introduced as a potent extraction method for extraction of natural compounds, but it is seldom used for peptide and protein extraction. In this work, microwave irradiation was applied to the extraction of cyclotides. The procedure was performed in various steps using a microwave instrument under different conditions. High-performance liquid chromatography (HPLC) and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) results show stability of cyclotide structures on microwave radiation. The influential parameters, including time, temperature, and the ratio of solvents that are affecting the MAE potency, were optimized. Optimal conditions were obtained at 20 min of irradiation time, 1200 W of system power in 60 °C, and methanol/water at the ratio of 90:10 (v/v) as solvent. The comparison of MAE results with maceration extraction shows that there are similarities between cyclotide sequences and extraction yields. Copyright © 2015 Elsevier Inc. All rights reserved.

Optimization of ultrasound and microwave assisted extractions of polyphenols from black rice (Oryza sativa cv. Poireton) husk.

PubMed

Jha, Pankaj; Das, Arup Jyoti; Deka, Sankar Chandra

2017-11-01

Phenolic compounds were extracted from the husk of milled black rice (cv. Poireton) by using a combination of ultrasound assisted extraction and microwave assisted extraction. Extraction parameters were optimized by response surface methodology according to a three levels, five variables Box-Behnken design. The appropriate process variables (extraction temperature and extraction time) to maximize the ethanolic extraction of total phenolic compounds, flavonoids, anthocyanins and antioxidant activity of the extracts were obtained. Extraction of functional components with varying ethanol concentration and microwave time were significantly affected by the process variables. The best possible conditions obtained by RSM for all the factors included 10.02 min sonication time, 49.46 °C sonication temperature, 1:40.79 (w/v) solute solvent ratio, 67.34% ethanol concentration, and 31.11 s microwave time. Under the given solutions, the maximum extraction of phenolics (1.65 mg/g GAE), flavonoids (3.04 mg/100 g), anthocyanins (3.39 mg/100 g) and antioxidants (100%) were predicted, while the experimental values included 1.72 mg/g GAE of total phenolics, 3.01 mg/100 g of flavonoids, 3.36 mg/100 g of anthocyanins and 100% antioxidant activity. The overall results indicated positive impact of co-application of microwave and ultrasound assisted extractions of phenolic compounds from black rice husk.

Optimization of alcohol-assisted dispersive liquid-liquid microextraction by experimental design for the rapid determination of fluoxetine in biological samples.

PubMed

Hamedi, Raheleh; Hadjmohammadi, Mohammad Reza

2016-12-01

A sensitive and rapid method based on alcohol-assisted dispersive liquid-liquid microextraction followed by high-performance liquid chromatography for the determination of fluoxetine in human plasma and urine samples was developed. The effects of six parameters on the extraction recovery were investigated and optimized utilizing Plackett-Burman design and Box-Benken design, respectively. According to the Plackett-Burman design results, the volume of disperser solvent, extraction time, and stirring speed had no effect on the recovery of fluoxetine. The optimized conditions included a mixture of 172 μL of 1-octanol as extraction solvent and 400 μL of methanol as disperser solvent, pH of 11.3 and 0% w/v of salt in the sample solution. Replicating the experiment in optimized condition for five times, gave the average extraction recoveries equal to 90.15%. The detection limit of fluoxetine in human plasma was obtained 3 ng/mL, and the linearity was in the range of 10-1200 ng/mL. The corresponding values for human urine were 4.2 ng/mL with the linearity range from 10 to 2000 ng/mL. Relative standard deviations for intra and inter day extraction of fluoxetine were less than 7% in five measurements. The developed method was successfully applied for the determination of fluoxetine in human plasma and urine samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of an electrical model for integrated magnetic inductors

NASA Astrophysics Data System (ADS)

Bechir, M. B.; Yaya, D. D.; Youssouf, M. K.; Soultan, M.; Capraro, S.; Siblini, A.; Chatelon, J. P.; Rousseau, J. J.

2014-07-01

Nowadays, the current trend consists in the development of new technologies with the aim of reducing volume, weight as well as production cost. With the aim of decreasing occupied component area, it will be interesting to use magnetic materials to confine the fields. Therefore, our works concern the modelling and the characterization of magnetic planar inductors. The proposed model is detailed for inductors fabricated with one magnetic layer. The model can take into account, the capacitance between turns and the capacitance between the last turn and the ground plane, the magnetic permeability, the skin and proximity effects of the conductors according to the frequency. The structure of optimization developed to extract the parameters of the model will be presented. Results of extracted parameters are compared with the simulation parameters. A good correlation is observed on Y11 and Y12 parameters on all the broad band frequency.

Determination of Aristolochic Acid in Botanicals and Dietary Supplements by Liquid Chromatography with Ultraviolet Detection and by Liquid Chromatography/Mass Spectrometry: Single Laboratory Validation Confirmation

PubMed Central

Trujillo, William A.; Sorenson, Wendy R.; La Luzerne, Paul; Austad, John W.; Sullivan, Darryl

2008-01-01

The presence of aristolochic acid in some dietary supplements is a concern to regulators and consumers. A method has been developed, by initially using a reference method as a guide, during single laboratory validation (SLV) for the determination of aristolochic acid I, also known as aristolochic acid A, in botanical species and dietary supplements at concentrations of approximately 2 to 32 μg/g. Higher levels were determined by dilution to fit the standard curve. Through the SLV, the method was optimized for quantification by liquid Chromatography with ultraviolet detection (LC-UV) and LC/mass Spectrometry (MS) confirmation. The test samples were extracted with organic solvent and water, then injected on a reverse phase LC column. Quantification was achieved with linear regression using a laboratory automation system. The SLV study included systematically optimizing the LC-UV method with regard to test sample size, fine grinding of solids, and solvent extraction efficiency. These parameters were varied in increments (and in separate optimization studies), in order to ensure that each parameter was individually studied; the test results include corresponding tables of parameter variations. In addition, the chromatographic conditions were optimized with respect to injection volume and detection wavelength. Precision studies produced overall relative standard deviation values from 2.44 up to 8.26% for aristolochic acid I. Mean recoveries were between 100 and 103% at the 2 μg/g level, between 102 and 103% at the 10 μg/g level, and 104% at the 30 μg/g level. PMID:16915829

Determination of aristolochic acid in botanicals and dietary supplements by liquid chromatography with ultraviolet detection and by liquid chromatography/mass spectrometry: single laboratory validation confirmation.

PubMed

Trujillo, William A; Sorenson, Wendy R; La Luzerne, Paul; Austad, John W; Sullivan, Darryl

2006-01-01

The presence of aristolochic acid in some dietary supplements is a concern to regulators and consumers. A method has been developed, by initially using a reference method as a guide, during single laboratory validation (SLV) for the determination of aristolochic acid I, also known as aristolochic acid A, in botanical species and dietary supplements at concentrations of approximately 2 to 32 microg/g. Higher levels were determined by dilution to fit the standard curve. Through the SLV, the method was optimized for quantification by liquid chromatography with ultraviolet detection (LC-UV) and LC/mass spectrometry (MS) confirmation. The test samples were extracted with organic solvent and water, then injected on a reverse phase LC column. Quantification was achieved with linear regression using a laboratory automation system. The SLV study included systematically optimizing the LC-UV method with regard to test sample size, fine grinding of solids, and solvent extraction efficiency. These parameters were varied in increments (and in separate optimization studies), in order to ensure that each parameter was individually studied; the test results include corresponding tables of parameter variations. In addition, the chromatographic conditions were optimized with respect to injection volume and detection wavelength. Precision studies produced overall relative standard deviation values from 2.44 up to 8.26% for aristolochic acid I. Mean recoveries were between 100 and 103% at the 2 microg/g level, between 102 and 103% at the 10 microg/g level, and 104% at the 30 microg/g level.

Microwave-assisted extraction of three bioactive alkaloids from Peganum harmala L. and their acaricidal activity against Psoroptes cuniculi in vitro.

PubMed

Shang, Xiaofei; Guo, Xiao; Li, Bing; Pan, Hu; Zhang, Jiyu; Zhang, Yu; Miao, Xiaolou

2016-11-04

Peganum harmala L. is a perennial herbaceous, glabrous plant that grows in semi-arid conditions, steppe areas and sandy soils. It is used to treat fever, diarrhoea, subcutaneous tumours, arthralgia, rheumatism, cough, amnesia and parasitic diseases in folk medicines. In this paper, we aimed to develop a simpler and faster method for the extraction of three alkaloids from Peganum harmala L. than other conventional methods by optimizing the parameters of a microwave-assisted extraction (MAE) method, and to investigate the acaricidal activities of three compounds against Psoroptes cuniculi. After optimizing the operating parameters with the single factor experiment and a Box-Behnken design combined with a response-surface methodology, a MAE method was developed for extracting the alkaloids from the seeds, and a high-performance liquid chromatography was used to quantify these compounds. An in vitro experiments were used to study the acaricidal activities. The optimal conditions of MAE method were as follows: liquid-to-solid ratio 31.3:1mL/g, ethanol concentration 75.5%, extraction time 10.1min, temperature 80.7°C, and microwave power 600W. Compared to the heat reflux extraction (HRE, 60min) and the ultrasonic-assisted extraction (UAE, 30min) methods, MAE method require the shortest time (10min) and obtain the highest yield of three compounds (61.9mg/g). Meanwhile, the LT 50 values for the vasicine (1.25 and 2.5mg/mL), harmaline (1.25 and 2.5mg/mL), harmine (1.25 and 2.5mg/mL) and MAE extract (100mg/mL) against Psoroptes cuniculi were 12.188h, 9.791h, 11.994h, 10.095h, 11.293h, 9.273h and 17.322h, respectively. The MAE method developed exhibited the highest extraction yield within the shortest time and thus could be used to extract the active compounds from Peganum harmala L. on an industrial basis. As the active compounds of Peganum harmala L., vasicine, harmalin and harmine presented the marked acaricidal activities against Psoroptes cuniculi, and could be widely applied for the treatments of acariasis in animals. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Antitumor activity of Annona squamosa seed oil.

PubMed

Chen, Yong; Chen, Yayun; Shi, Yeye; Ma, Chengyao; Wang, Xunan; Li, Yue; Miao, Yunjie; Chen, Jianwei; Li, Xiang

2016-12-04

Custard apple (Annona squamosa Linn.) is an edible tropical fruit, and its seeds have been used to treat "malignant sore" (cancer) and other usage as insecticide. A comparison of extraction processes, chemical composition analysis and antitumor activity of A. squamosa seed oil (ASO) were investigated. The optimal extraction parameters of ASO were established by comparing percolation, soxhlet, ultrasonic and SFE-CO 2 extraction methods. The chemical composition of fatty acid and content of total annonaceous acetogenins (ACGs) of ASO was investigated by GC-MS and colorimetric assay, and anti-tumor activity of ASO was tested using H 22 xenografts bearing mice. The optimal extraction parameters of ASO were obtained as follows: using soxhlet extraction method with extraction solvent of petroleum ether, temperature of 80°C, and extraction time of 90min. Under these conditions, the yield of ASO was 22.65%. GC-MS analysis results showed that the main chemical compositions of fatty acid of ASO were palmitic acid (9.92%), linoleic acid (20.49%), oleic acid (56.50%) and stearic acid (9.14%). The total ACGs content in ASO was 41.00mg/g. ASO inhibited the growth of H 22 tumor cells in mice with a maximum inhibitory rate of 53.54% by oral administration. Furthermore, it was found that ASO exerted an antitumor effect via decreasing interleukin-6 (IL-6), janus kinase (Jak) and phosphorylated signal transducers and activators of transcription (p-Stat3) expression. The results demonstrated that ASO suppressed the H 22 solid tumor development may due to its main chemical constituents unsaturated fatty acid and ACGs via IL-6/Jak/Stat3 pathway. ASO may be a potential candidate for the treatment of cancer. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Dispersive liquid-liquid microextraction of quinolones in porcine blood: Optimization of extraction procedure and CE separation using experimental design.

PubMed

Vera-Candioti, Luciana; Teglia, Carla M; Cámara, María S

2016-10-01

A dispersive liquid-liquid microextraction procedure was developed to extract nine fluoroquinolones in porcine blood, six of which were quantified using a univariate calibration method. Extraction parameters including type and volume of extraction and dispersive solvent and pH, were optimized using a full factorial and a central composite designs. The optimum extraction parameters were a mixture of 250 μL dichloromethane (extract solvent) and 1250 μL ACN (dispersive solvent) in 500 μL of porcine blood reached to pH 6.80. After shaking and centrifugation, the upper phase was transferred in a glass tube and evaporated under N 2 steam. The residue was resuspended into 50 μL of water-ACN (70:30, v/v) and determined by CE method with DAD, under optimum separation conditions. Consequently, a tenfold enrichment factor can potentially be reached with the pretreatment, taking into account the relationship between initial sample volume and final extract volume. Optimum separation conditions were as follows: BGE solution containing equal amounts of sodium borate (Na 2 B 4 O 7 ) and di-sodium hydrogen phosphate (Na 2 HPO 4 ) with a final concentration of 23 mmol/L containing 0.2% of poly (diallyldimethylammonium chloride) and adjusted to pH 7.80. Separation was performed applying a negative potential of 25 kV, the cartridge was maintained at 25.0°C and the electropherograms were recorded at 275 nm during 4 min. The hydrodynamic injection was performed in the cathode by applying a pressure of 50 mbar for 10 s. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An Optimized Analytical Method for the Simultaneous Detection of Iodoform, Iodoacetic Acid, and Other Trihalomethanes and Haloacetic Acids in Drinking Water

PubMed Central

Jiang, Songhui; Templeton, Michael R.; He, Gengsheng; Qu, Weidong

2013-01-01

An optimized method is presented using liquid-liquid extraction and derivatization for the extraction of iodoacetic acid (IAA) and other haloacetic acids (HAA9) and direct extraction of iodoform (IF) and other trihalomethanes (THM4) from drinking water, followed by detection by gas chromatography with electron capture detection (GC-ECD). A Doehlert experimental design was performed to determine the optimum conditions for the five most significant factors in the derivatization step: namely, the volume and concentration of acidic methanol (optimized values  = 15%, 1 mL), the volume and concentration of Na2SO4 solution (129 g/L, 8.5 mL), and the volume of saturated NaHCO3 solution (1 mL). Also, derivatization time and temperature were optimized by a two-variable Doehlert design, resulting in the following optimized parameters: an extraction time of 11 minutes for IF and THM4 and 14 minutes for IAA and HAA9; mass of anhydrous Na2SO4 of 4 g for IF and THM4 and 16 g for IAA and HAA9; derivatization time of 160 min and temperature at 40°C. Under optimal conditions, the optimized procedure achieves excellent linearity (R2 ranges 0.9990–0.9998), low detection limits (0.0008–0.2 µg/L), low quantification limits (0.008–0.4 µg/L), and good recovery (86.6%–106.3%). Intra- and inter-day precision were less than 8.9% and 8.8%, respectively. The method was validated by applying it to the analysis of raw, flocculated, settled, and finished waters collected from a water treatment plant in China. PMID:23613747

On the hydrophilicity of electrodes for capacitive energy extraction

NASA Astrophysics Data System (ADS)

Lian, Cheng; Kong, Xian; Liu, Honglai; Wu, Jianzhong

2016-11-01

The so-called Capmix technique for energy extraction is based on the cyclic expansion of electrical double layers to harvest dissipative energy arising from the salinity difference between freshwater and seawater. Its optimal performance requires a careful selection of the electrical potentials for the charging and discharging processes, which must be matched with the pore characteristics of the electrode materials. While a number of recent studies have examined the effects of the electrode pore size and geometry on the capacitive energy extraction processes, there is little knowledge on how the surface properties of the electrodes affect the thermodynamic efficiency. In this work, we investigate the Capmix processes using the classical density functional theory for a realistic model of electrolyte solutions. The theoretical predictions allow us to identify optimal operation parameters for capacitive energy extraction with porous electrodes of different surface hydrophobicity. In agreement with recent experiments, we find that the thermodynamic efficiency can be much improved by using most hydrophilic electrodes.

Ultrasound-Assisted Extraction, Antioxidant and Anticancer Activities of the Polysaccharides from Rhynchosia minima Root.

PubMed

Jia, Xuejing; Zhang, Chao; Hu, Jie; He, Muxue; Bao, Jiaolin; Wang, Kai; Li, Peng; Chen, Meiwan; Wan, Jianbo; Su, Huanxing; Zhang, Qingwen; He, Chengwei

2015-11-23

Box-Behnken design (BBD), one of the most common response surface methodology (RSM) methods, was used to optimize the experimental conditions for ultrasound-assisted extraction of polysaccharides from Rhynchosia minima root (PRM). The antioxidant abilities and anticancer activity of purified polysaccharide fractions were also measured. The results showed that optimal extraction parameters were as follows: ultrasound exposure time, 21 min; ratio of water to material, 46 mL/g; ultrasound extraction temperature, 63 °C. Under these conditions, the maximum yield of PRM was 16.95%±0.07%. Furthermore, the main monosaccharides of purified fractions were Ara and Gal. PRM3 and PRM5 exhibited remarkable DPPH radical scavenging activities and reducing power in vitro. PRM3 showed strong inhibitory activities on the growth of MCF-7 cells in vitro. The above results indicate that polysaccharides from R. minima root have the potential to be developed as natural antioxidants and anticancer ingredients for the food and pharmaceutical industries.

On the hydrophilicity of electrodes for capacitive energy extraction

DOE PAGES

Lian, Cheng; East China Univ. of Science and Technology, Shanghai; Kong, Xian; ...

2016-09-14

The so-called Capmix technique for energy extraction is based on the cyclic expansion of electrical double layers to harvest dissipative energy arising from the salinity difference between freshwater and seawater. Its optimal performance requires a careful selection of the electrical potentials for the charging and discharging processes, which must be matched with the pore characteristics of the electrode materials. While a number of recent studies have examined the effects of the electrode pore size and geometry on the capacitive energy extraction processes, there is little knowledge on how the surface properties of the electrodes affect the thermodynamic efficiency. In thismore » paper, we investigate the Capmix processes using the classical density functional theory for a realistic model of electrolyte solutions. The theoretical predictions allow us to identify optimal operation parameters for capacitive energy extraction with porous electrodes of different surface hydrophobicity. Finally, in agreement with recent experiments, we find that the thermodynamic efficiency can be much improved by using most hydrophilic electrodes.« less

Ultrasound-assisted extraction of phenolic compounds from Cratoxylum formosum ssp. formosum leaves using central composite design and evaluation of its protective ability against H2O2-induced cell death.

PubMed

Yingngam, Bancha; Monschein, Marlene; Brantner, Adelheid

2014-09-01

To optimize the processing parameters for phenolic compounds extracted from Cratoxylum formosum ssp. formosum leaves using an ultrasound-assisted extraction and to evaluate its protective ability against H2O2-induced cell death. The influence of three independent variables including ethanol concentration (%), extraction temperature (°C) and extraction time (min) on the extraction yield of phenolic compounds were optimized using a central composite design-based response surface methodology. The obtained extract was assessed for its antioxidant activity by DPPH(•) and ABTS(•)(+) methods. Cellular protective ability against H2O2-induced cell death was evaluated on HEK293 cells using the MTT assay. The optimal conditions to achieve maximal yields of phenolic compounds were ethanol concentration of 50.33% (v/v), temperature of 65 °C, and extractiontion time of 15 min. The yield of phenolic compounds was (40.00±1.00) mg gallic acid equivalent/g dry powder which matched well with the values predicted from the proposed model. These conditions resulted in a higher efficiency concerning the extraction of phenolics compared to a conventional heat reflux extraction by providing shorter extraction time and reduced energy consumption. 5-O-caffeoylquinic acid identified by high performance liquid chromatography-diode array detector-electron spin ionization-mass spectrometry was the major compound in the obtained extract [(41.66±0.07) mg/g plant extract]. The obtained extract showed a strong ability to scavenge both DPPH(•) and ABTS(•)(+) free radicals and exhibited additionally good ability to protect HEK293 cells death against oxidative stress. These results indicate the suitability of ultrasound-assisted extraction for the extraction of phenolic compounds from Cratoxylum formosum ssp. formosum leaves. This phenolic-enriched extract can be used as valuable antioxidant source for health benefits. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Application of micro-solid-phase extraction for the on-site extraction of heterocyclic aromatic amines in seawater.

PubMed

Basheer, Chanbasha

2018-04-01

An efficient on-site extraction technique to determine carcinogenic heterocyclic aromatic amines in seawater has been reported. A micro-solid-phase extraction device placed inside a portable battery-operated pump was used for the on-site extraction of seawater samples. Before on-site applications, parameters that influence the extraction efficiency (extraction time, type of sorbent materials, suitable desorption solvent, desorption time, and sample volume) were investigated and optimized in the laboratory. The developed method was then used for the on-site sampling of heterocyclic aromatic amines determination in seawater samples close to distillation plant. Once the on-site extraction completed, the small extraction device with the analytes was brought back to the laboratory for analysis using high-performance liquid chromatography with fluorescence detection. Based on the optimized conditions, the calibration curves were linear over the concentration range of 0.05-20 μg/L with correlation coefficients up to 0.996. The limits of detection were 0.004-0.026 μg/L, and the reproducibility values were between 1.3 and 7.5%. To evaluate the extraction efficiency, a comparison was made with conventional solid-phase extraction and it was applied to various fortified real seawater samples. The average relative recoveries obtained from the spiked seawater samples varied in the range 79.9-95.2%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Procedure optimization for green synthesis of silver nanoparticles by aqueous extract of Eucalyptus oleosa.

PubMed

Pourmortazavi, Seied Mahdi; Taghdiri, Mehdi; Makari, Vajihe; Rahimi-Nasrabadi, Mehdi

2015-02-05

The present study is dealing with the green synthesis of silver nanoparticles using the aqueous extract of Eucalyptus oleosa as a green synthesis procedure without any catalyst, template or surfactant. Colloidal silver nanoparticles were synthesized by reacting aqueous AgNO3 with E. oleosa leaf extract at non-photomediated conditions. The significance of some synthesis conditions such as: silver nitrate concentration, concentration of the plant extract, time of synthesis reaction and temperature of plant extraction procedure on the particle size of synthesized silver particles was investigated and optimized. The participations of the studied factors in controlling the particle size of reduced silver were quantitatively evaluated via analysis of variance (ANOVA). The results of this investigation showed that silver nanoparticles could be synthesized by tuning significant parameters, while performing the synthesis procedure at optimum conditions leads to form silver nanoparticles with 21nm as averaged size. Ultraviolet-visible spectroscopy was used to monitor the development of silver nanoparticles formation. Meanwhile, produced silver nanoparticles were characterized by scanning electron microscopy, energy-dispersive X-ray, and FT-IR techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

Ultrasound-assisted extraction of amino acids from grapes.

PubMed

Carrera, Ceferino; Ruiz-Rodríguez, Ana; Palma, Miguel; Barroso, Carmelo G

2015-01-01

Recent cultivar techniques on vineyards can have a marked influence on the final nitrogen content of grapes, specifically individual amino acid contents. Furthermore, individual amino acid contents in grapes are related to the final aromatic composition of wines. A new ultrasound-assisted method for the extraction of amino acids from grapes has been developed. Several extraction variables, including solvent (water/ethanol mixtures), solvent pH (2-7), temperature (10-70°C), ultrasonic power (20-70%) and ultrasonic frequency (0.2-1.0s(-)(1)), were optimized to guarantee full recovery of the amino acids from grapes. An experimental design was employed to optimize the extraction parameters. The surface response methodology was used to evaluate the effects of the extraction variables. The analytical properties of the new method were established, including limit of detection (average value 1.4mmolkg(-)(1)), limit of quantification (average value 2.6mmolkg(-)(1)), repeatability (average RSD=12.9%) and reproducibility (average RSD=15.7%). Finally, the new method was applied to three cultivars of white grape throughout the ripening period. Copyright © 2014 Elsevier B.V. All rights reserved.

Determination of rutin and quercetin in Chinese herbal medicine by ionic liquid-based pressurized liquid extraction-liquid chromatography-chemiluminescence detection.

PubMed

Wu, Hongwei; Chen, Meilan; Fan, Yunchang; Elsebaei, Fawzi; Zhu, Yan

2012-01-15

A novel ionic liquid-based pressurized liquid extraction (IL-PLE) procedure coupled with high performance liquid chromatography (HPLC) tandem chemiluminescence (CL) detection capable of quantifying trace amounts of rutin and quercetin in four Chinese medicine plants including Flos sophorae Immaturus, Crateagus pinnatifida Bunge, Hypericum japonicum Thunb and Folium Mori was described in this paper. To avoid environmental pollution and toxicity to the operators, ionic liquids (ILs), 1-alkyl-3-methylimidazolium chloride ([C(n)mim][Cl]) aqueous solutions were used in the PLE procedure as extractants replacing traditional organic solvents. In addition, chemiluminescence detection was utilized for its minimal interference from endogenous components of complex matrix. Parameters affecting extraction and analysis were carefully optimized. Compared with the conventional ultrasonic-assisted extraction (UAE) and heat-reflux extraction (HRE), the optimized method achieved the highest extraction efficiency in the shortest extraction time with the least solvent consumption. The applicability of the proposed method to real sample was confirmed. Under the optimized conditions, good reproducibility of extraction performance was obtained and good linearity was observed with correlation coefficients (r) between 0.9997 and 0.9999. The detection limits of rutin and quercetin (LOD, S/N=3) were 1.1×10(-2)mg/L and 3.8×10(-3)mg/L, respectively. The average recoveries of rutin and quercetin for real samples were 93.7-105% with relative standard deviation (RSD) lower than 5.7%. To the best of our knowledge, this paper is the first contribution to utilize a combination of IL-PLE with chemiluminescence detection. And the experimental results indicated that the proposed method shows a promising prospect in extraction and determination of rutin and quercetin in medicinal plants. Copyright © 2011 Elsevier B.V. All rights reserved.

Microwave-assisted extraction of oxymatrine from Sophora flavescens.

PubMed

Xia, En-Qin; Cui, Bo; Xu, Xiang-Rong; Song, Yang; Ai, Xu-Xia; Li, Hua-Bin

2011-08-30

In this paper, microwave-assisted extraction (MAE) of oxymatrine from Sophora flavescens were studied by HPLC-photodiode array detection. Effects of several experimental parameters, such as concentration of extraction solvent, ratio of liquid to material, microwave power, extraction temperature, and extraction time on the extraction efficiencies of oxymatrine were evaluated. The optimal extraction conditions were 60% ethanol, a 20:1 (v/v) ratio of liquid to material and extraction for 10 min at 50 °C under 500 W microwave irradiation. Under the optimum conditions, the yield of oxymatrine was 14.37 mg/g. The crude extract obtained could be used as either a component of some complex traditional medicines or for further isolation and purification of bioactive compounds. The results, which indicated that MAE is a very useful tool for the extraction of important phytochemicals from plant materials, should prove helpful for the full utilization of Sophora flavescens.

Development of pressurized subcritical water extraction combined with stir bar sorptive extraction for the analysis of organochlorine pesticides and chlorobenzenes in soils.

PubMed

Rodil, Rosario; Popp, Peter

2006-08-18

An analytical method for the determination of several organochlorine pesticides (OCPs) like hexachlorocyclohexanes (HCHs), cyclodiene derivates (dieldrin, aldrin, endrin, heptachlor, heptachlor epoxide, endrin aldehyde, endosulfan and ensodulfan sulphate) and DDX compounds (p,p'-DDE, p,p'-DDD and p,p'-DDT) as well as chlorobenzenes in soils has been developed. The procedure is based on pressurized subcritical water extraction (PSWE) followed by stir bar sorptive extraction (SBSE) and subsequent thermodesorption-gas chromatography/mass spectrometry analysis. Significant PSWE and SBSE parameters were optimized using spiked soil and water samples. For the PSWE of the organochlorine compounds, water modified with acetonitrile as the extraction solvent, at an extraction temperature of 120 degrees C, and three cycles of 10 min extraction proved to be optimal. Under optimized conditions, the figures of merit, such as precision, accuracy and detection limits were evaluated. The detection limits obtained for soil samples were in the range 0.002-4.7 ng/g. Recoveries between 4.1 and 85.2% were achieved from samples spiked at a concentration level of 25-155 ng/g. The main advantages of this method are the avoidance of clean-up and concentration procedures as well as the significant reduction of the required volume of organic solvents. The described method was applied to the determination of the pollutants in soil samples collected from a polluted area, the Bitterfeld region (Germany). The results obtained by PSWE-SBSE were in a good agreement with those obtained by a reference method, a conventional pressurized liquid extraction (PLE).

Carbon coated magnetic nanoparticles as a novel magnetic solid phase extraction adsorbent for simultaneous extraction of methamphetamine and ephedrine from urine samples.

PubMed

Taghvimi, Arezou; Hamishehkar, Hamed

2017-01-15

This paper develops a highly selective, specific and efficient method for simultaneous determination of ephedrine and methamphetamine by a new carbon coated magnetic nanoparticles (C/MNPs) as a magnetic solid phase extraction (MSPE) adsorbent in biological urine medium. The characterization of synthesized magnetic nano adsorbent was completely carried out by various characterization techniques like Fourier transform infrared (FT-IR) spectroscopy, powder x-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). Nine important parameters influencing extraction efficiency including amount of adsorbent, amounts of sample volume, pH, type and amount of extraction organic solvent, time of extraction and desorption, agitation rate and ionic strength of extraction medium, were studied and optimized. Under optimized extraction conditions, a good linearity was observed in the concentration range of 100-2000ng/mL for ephedrine and 100-2500ng/mL for methamphetamine. Analysis of positive urine samples was carried out by proposed method with the recovery of 98.71 and 97.87% for ephedrine and methamphetamine, respectively. The results indicated that carbon coated magnetic nanoparticles could be applied in clinical and forensic laboratories for simultaneous determination of abused drugs in urine media. Copyright © 2016 Elsevier B.V. All rights reserved.

Microwave-assisted extraction of herbacetin diglucoside from flax (Linum usitatissimum L.) seed cakes and its quantification using an RP-HPLC-UV system.

PubMed

Fliniaux, Ophélie; Corbin, Cyrielle; Ramsay, Aina; Renouard, Sullivan; Beejmohun, Vickram; Doussot, Joël; Falguières, Annie; Ferroud, Clotilde; Lamblin, Frédéric; Lainé, Eric; Roscher, Albrecht; Grand, Eric; Mesnard, François; Hano, Christophe

2014-03-10

Flax (Linum usitatissimum L.) seeds are widely used for oil extraction and the cold-pressed flaxseed (or linseed) cakes obtained during this process constitute a valuable by-product. The flavonol herbacetin diglucoside (HDG) has been previously reported as a constituent of the flaxseed lignan macromolecule linked through ester bonds to the linker molecule hydroxymethylglutaric acid. In this context, the development and validation of a new approach using microwave-assisted extraction (MAE) of HDG from flaxseed cakes followed by quantification with a reverse-phase HPLC system with UV detection was purposed. The experimental parameters affecting the HDG extraction yield, such as microwave power, extraction time and sodium hydroxide concentration, from the lignan macromolecule were optimized. A maximum HDG concentration of 5.76 mg/g DW in flaxseed cakes was measured following an irradiation time of 6 min, for a microwave power of 150 W using a direct extraction in 0.1 M NaOH in 70% (v/v) aqueous methanol. The optimized method was proven to be rapid and reliable in terms of precision, repeatability, stability and accuracy for the extraction of HDG. Comparison with a conventional extraction method demonstrated that MAE is more effective and less time-consuming.

Application of modified stir bar with nickel:zinc sulphide nanoparticles loaded on activated carbon as a sorbent for preconcentration of losartan and valsartan and their determination by high performance liquid chromatography.

PubMed

Pebdani, Arezou Amiri; Dadfarnia, Shayesteh; Shabani, Ali Mohammad Haji; Khodadoust, Saeid; Haghgoo, Soheila

2016-03-11

In this study, the stir bar was coated for the first time with the ​nicel:zins sulphide nanoparticles (Ni:ZnS NPs) loaded on activated carbon (AC) (Ni:ZnS-AC) as well as 1-ethyl-3-methylimidazolium hexafluorophosphate ionic liquid (IL) using sol gel technique and was used for stir bar sorptive extraction (SBSE) of losartan (LOS) and valsartan (VAL) as the model compounds. The extracted analytes were then quantified by high performance liquid chromatography (HPLC) equipped with an ultra violet detector. The best extraction performance for LOS and VAL was obtained through the optimization of the parameters affecting SBSE including pH of sample solution, ionic strength, extraction time, volume of desorption solvent, desorption time, and stirring speed. The fractional factorial design (FFD) was used to find the most important parameters, which were then optimized by the central composite design (CCD) and the desirability function (DF). Under the optimal experimental conditions, wide linear ranges of 0.4-50μgL(-1) and 0.5-50μgL(-1) and good RSDs (at level of 5μgL(-1) and n=6) of 4.4 and 4.9% were obtained for LOS and VAL, respectively. With the enrichment factors (EFs) of 188.6 and 184.8-fold, the limits of detection (LODs, S/N=3) of the developed method were found to be 0.12 and 0.15μgL(-1) for LOS and VAL, respectively. The developed method was successfully applied to the determination of LOS and VAL in urine and plasma matrices. Copyright © 2016 Elsevier B.V. All rights reserved.

Low Density Solvent-Based Dispersive Liquid-Liquid Microextraction for the Determination of Synthetic Antioxidants in Beverages by High-Performance Liquid Chromatography

PubMed Central

Çabuk, Hasan; Köktürk, Mustafa

2013-01-01

A simple and efficient method was established for the determination of synthetic antioxidants in beverages by using dispersive liquid-liquid microextraction combined with high-performance liquid chromatography with ultraviolet detection. Butylated hydroxy toluene, butylated hydroxy anisole, and tert-butylhydroquinone were the antioxidants evaluated. Experimental parameters including extraction solvent, dispersive solvent, pH of sample solution, salt concentration, and extraction time were optimized. Under optimal conditions, the extraction recoveries ranged from 53 to 96%. Good linearity was observed by the square of correlation coefficients ranging from 0.9975 to 0.9997. The relative standard deviations ranged from 1.0 to 5.2% for all of the analytes. Limits of detection ranged from 0.85 to 2.73 ng mL−1. The method was successfully applied for determination of synthetic antioxidants in undiluted beverage samples with satisfactory recoveries. PMID:23853535

A molecular theory for optimal blue energy extraction by electrical double layer expansion

DOE PAGES

Kong, Xian; Gallegos, Alejandro; Lu, Diannan; ...

2015-08-19

We proposed the electrical double layer expansion (CDLE) as a promising alternative to reverse electrodialysis (RED) and pressure retarded osmosis (PRO) processes for extracting osmotic power generated by the salinity difference between freshwater and seawater. The performance of the CDLE process is sensitive to the configuration of porous electrodes and operation parameters for ion extraction and release cycles. In our work, we use a classical density functional theory (CDFT) to examine how the electrode pore size and charging/discharging potentials influence the thermodynamic efficiency of the CDLE cycle. The existence of an optimal charging potential that maximizes the energy output formore » a given pore configuration is predicted, which varies substantially with the pore size, especially when it is smaller than 2 nm. Finally, the thermodynamic efficiency is maximized when the electrode has a pore size about twice the ion diameter.« less

Rapid Determination of Trace Palladium in Active Pharmaceutical Ingredients by Magnetic Solid-Phase Extraction and Flame Atomic Absorption Spectrometry

NASA Astrophysics Data System (ADS)

Yin, Q. H.; Zhu, D. M.; Yang, D. Z.; Hu, Q. F.; Yang, Y. L.

2018-01-01

Clutaraldehyde cross-linked magnetic chitosan nanoparticles were synthesized and used as an adsorbent for the dispersive solid-phase extraction of palladium in active pharmaceutical ingredients (APIs) prior to analysis by a flame atomic absorption spectrophotometer. FT-IR, X-ray diffraction, and TEM were used to characterize the adsorbent. Various parameters of experimental performance, such as adsorbent amount, pH, adsorption time, desorption solutions, coexisting ions, and adsorbent reusability, were investigated and optimized. Under the optimized conditions, good linearity was achieved in the 5.0-500 μg/L concentration range, with correlation coefficients of 0.9989. The limit of detection is 2.8 μg/L and the recoveries of spiked samples ranged from 91.7 to 97.6%. It was confirmed that the GMCNs nanocomposite was a promising adsorbing material for extraction and preconcentration of Pd in APIs.

Using evolutionary computation to optimize an SVM used in detecting buried objects in FLIR imagery

NASA Astrophysics Data System (ADS)

Paino, Alex; Popescu, Mihail; Keller, James M.; Stone, Kevin

2013-06-01

In this paper we describe an approach for optimizing the parameters of a Support Vector Machine (SVM) as part of an algorithm used to detect buried objects in forward looking infrared (FLIR) imagery captured by a camera installed on a moving vehicle. The overall algorithm consists of a spot-finding procedure (to look for potential targets) followed by the extraction of several features from the neighborhood of each spot. The features include local binary pattern (LBP) and histogram of oriented gradients (HOG) as these are good at detecting texture classes. Finally, we project and sum each hit into UTM space along with its confidence value (obtained from the SVM), producing a confidence map for ROC analysis. In this work, we use an Evolutionary Computation Algorithm (ECA) to optimize various parameters involved in the system, such as the combination of features used, parameters on the Canny edge detector, the SVM kernel, and various HOG and LBP parameters. To validate our approach, we compare results obtained from an SVM using parameters obtained through our ECA technique with those previously selected by hand through several iterations of "guess and check".

Application of Chitosan-Zinc Oxide Nanoparticles for Lead Extraction From Water Samples by Combining Ant Colony Optimization with Artificial Neural Network

NASA Astrophysics Data System (ADS)

Khajeh, M.; Pourkarami, A.; Arefnejad, E.; Bohlooli, M.; Khatibi, A.; Ghaffari-Moghaddam, M.; Zareian-Jahromi, S.

2017-09-01

Chitosan-zinc oxide nanoparticles (CZPs) were developed for solid-phase extraction. Combined artificial neural network-ant colony optimization (ANN-ACO) was used for the simultaneous preconcentration and determination of lead (Pb2+) ions in water samples prior to graphite furnace atomic absorption spectrometry (GF AAS). The solution pH, mass of adsorbent CZPs, amount of 1-(2-pyridylazo)-2-naphthol (PAN), which was used as a complexing agent, eluent volume, eluent concentration, and flow rates of sample and eluent were used as input parameters of the ANN model, and the percentage of extracted Pb2+ ions was used as the output variable of the model. A multilayer perception network with a back-propagation learning algorithm was used to fit the experimental data. The optimum conditions were obtained based on the ACO. Under the optimized conditions, the limit of detection for Pb2+ ions was found to be 0.078 μg/L. This procedure was also successfully used to determine the amounts of Pb2+ ions in various natural water samples.

Recovery of Vanadium from Magnetite Ore Using Direct Acid Leaching: Optimization of Parameters by Plackett-Burman and Response Surface Methodologies

NASA Astrophysics Data System (ADS)

Nejad, Davood Ghoddocy; Khanchi, Ali Reza; Taghizadeh, Majid

2018-06-01

Recovery of vanadium from magnetite ore by direct acid leaching is discussed. The proposed process, which employs a mixture of nitric and sulfuric acids, avoids pyrometallurgical treatments since such treatment consumes a high amount of energy. To determine the optimum conditions of vanadium recovery, the leaching process is optimized through Plackett-Burman (P-B) design and response surface methodology (RSM). In this respect, temperature (80-95°C), liquid to solid ratio (L/S) (3-10 mL g-1), sulfuric acid concentration (3-6 M), nitric acid concentration (5-10 vol.%) and time (4-8 h) are considered as the independent variables. According to the P-B approach, temperature and acid concentrations are, respectively, the most effective parameters in the leaching process. These parameters are optimized using RSM to maximize recovery of vanadium by direct acid leaching. In this way, 86.7% of vanadium can be extracted from magnetic ore.

Recovery of Vanadium from Magnetite Ore Using Direct Acid Leaching: Optimization of Parameters by Plackett-Burman and Response Surface Methodologies

NASA Astrophysics Data System (ADS)

Nejad, Davood Ghoddocy; Khanchi, Ali Reza; Taghizadeh, Majid

2018-03-01

Recovery of vanadium from magnetite ore by direct acid leaching is discussed. The proposed process, which employs a mixture of nitric and sulfuric acids, avoids pyrometallurgical treatments since such treatment consumes a high amount of energy. To determine the optimum conditions of vanadium recovery, the leaching process is optimized through Plackett-Burman (P-B) design and response surface methodology (RSM). In this respect, temperature (80-95°C), liquid to solid ratio (L/S) (3-10 mL g-1), sulfuric acid concentration (3-6 M), nitric acid concentration (5-10 vol.%) and time (4-8 h) are considered as the independent variables. According to the P-B approach, temperature and acid concentrations are, respectively, the most effective parameters in the leaching process. These parameters are optimized using RSM to maximize recovery of vanadium by direct acid leaching. In this way, 86.7% of vanadium can be extracted from magnetic ore.

Optimisation of solid-phase microextraction coupled to HPLC-UV for the determination of organochlorine pesticides and their metabolites in environmental liquid samples.

PubMed

Torres Padrón, M E; Sosa Ferrera, Z; Santana Rodríguez, J J

2006-09-01

A solid-phase microextraction (SPME) procedure using two commercial fibers coupled with high-performance liquid chromatography (HPLC) is presented for the extraction and determination of organochlorine pesticides in water samples. We have evaluated the extraction efficiency of this kind of compound using two different fibers: 60-mum polydimethylsiloxane-divinylbenzene (PDMS-DVB) and Carbowax/TPR-100 (CW/TPR). Parameters involved in the extraction and desorption procedures (e.g. extraction time, ionic strength, extraction temperature, desorption and soaking time) were studied and optimized to achieve the maximum efficiency. Results indicate that both PDMS-DVB and CW/TPR fibers are suitable for the extraction of this type of compound, and a simple calibration curve method based on simple aqueous standards can be used. All the correlation coefficients were better than 0.9950, and the RSDs ranged from 7% to 13% for 60-mum PDMS-DVB fiber and from 3% to 10% for CW/TPR fiber. Optimized procedures were applied to the determination of a mixture of six organochlorine pesticides in environmental liquid samples (sea, sewage and ground waters), employing HPLC with UV-diode array detector.

High-pressure processing as emergent technology for the extraction of bioactive ingredients from plant materials.

PubMed

Jun, Xi

2013-01-01

High-pressure processing is a food processing technique that has shown great potentials in the food industry. Recently, it was developed to extract bioactive ingredients from plant materials, known as ultrahigh pressure extraction (UPE), taking advantages of time saving, higher extraction yields, fewer impurities in the extraction solution, minimal heat and can avoid thermal degradation on the activity and structure of bioactive components, and so on. This review provides an overview of the developments in the UPE of bioactive ingredients from plant material. Apart from a brief presentation of the theories of UPE and extraction equipment systems, the principal parameters that influence the extraction efficiency to be optimized in the UPE (e.g., solvent, pressure, temperature, extraction time, and the number of cycle) were discussed in detail, and finally the more recent applications of UPE for the extraction of active compounds from plant materials were summarized.

Combination of dispersive liquid-liquid microextraction with flame atomic absorption spectrometry using microsample introduction for determination of lead in water samples.

PubMed

Naseri, Mohammad Taghi; Hemmatkhah, Payam; Hosseini, Mohammad Reza Milani; Assadi, Yaghoub

2008-03-03

The dispersive liquid-liquid microextraction (DLLME) was combined with the flame atomic absorption spectrometry (FAAS) for determination of lead in the water samples. Diethyldithiophosphoric acid (DDTP), carbon tetrachloride and methanol were used as chelating agent, extraction solvent and disperser solvent, respectively. A new FAAS sample introduction system was employed for the microvolume nebulization of the non-flammable chlorinated organic extracts. Injection of 20 microL volumes of the organic extract into an air-acetylene flame provided very sensitive spike-like and reproducible signals. Some effective parameters on the microextraction and the complex formation were selected and optimized. These parameters include extraction and disperser solvent type as well as their volume, extraction time, salt effect, pH and amount of the chelating agent. Under the optimized conditions, the enrichment factor of 450 was obtained from a sample volume of 25.0 mL. The enhancement factor, calculated as the ratio of the slopes of the calibration graphs with and without preconcentration, which was about 1000. The calibration graph was linear in the range of 1-70 microgL(-1) with a detection limit of 0.5 microgL(-1). The relative standard deviation (R.S.D.) for seven replicate measurements of 5.0 and 50 microgL(-1) of lead were 3.8 and 2.0%, respectively. The relative recoveries of lead in tap, well, river and seawater samples at the spiking level of 20 microgL(-1) ranged from 93.8 to 106.2%. The characteristics of the proposed method were compared with those of the liquid-liquid extraction (LLE), cloud point extraction (CPE), on-line and off-line solid-phase extraction (SPE) as well as co-precipitation, based on bibliographic data. Operation simplicity, rapidity, low cost, high enrichment factor, good repeatability, and low consumption of the extraction solvent at a microliter level are the main advantages of the proposed method.

Fabric phase sorptive extraction followed by UHPLC-MS/MS for the analysis of benzotriazole UV stabilizers in sewage samples.

PubMed

Montesdeoca-Esponda, Sarah; Sosa-Ferrera, Zoraida; Kabir, Abuzar; Furton, Kenneth G; Santana-Rodríguez, José Juan

2015-10-01

A fast and sensitive sample preparation strategy using fabric phase sorptive extraction followed by ultra-high-performance liquid chromatography and tandem mass spectrometry detection has been developed to analyse benzotriazole UV stabilizer compounds in aqueous samples. Benzotriazole UV stabilizer compounds are a group of compounds added to sunscreens and other personal care products which may present detrimental effects to aquatic ecosystems. Fabric phase sorptive extraction is a novel solvent minimized sample preparation approach that integrates the advantages of sol-gel derived hybrid inorganic-organic nanocomposite sorbents and the flexible, permeable and hydrophobic surface chemistry of polyester fabric. It is a highly sensitive, fast, efficient and inexpensive device that can be reused and does not suffer from coating damage, unlike SPME fibres or stir bars. In this paper, we optimized the extraction of seven benzotriazole UV filters evaluating the majority of the parameters involved in the extraction process, such as sorbent chemistry selection, extraction time, back-extraction solvent, back-extraction time and the impact of ionic strength. Under the optimized conditions, fabric phase sorptive extraction allows enrichment factors of 10 times with detection limits ranging from 6.01 to 60.7 ng L(-1) and intra- and inter-day % RSDs lower than 11 and 30 % for all compounds, respectively. The optimized sample preparation technique followed by ultra-high-performance liquid chromatography and tandem mass spectrometry detection was applied to determine the target analytes in sewage samples from wastewater treatment plants with different purification processes of Gran Canaria Island (Spain). Two UV stabilizer compounds were measured in ranges 17.0-60.5 ng mL(-1) (UV 328) and 69.3-99.2 ng mL(-1) (UV 360) in the three sewage water samples analysed.

Optimization of a multiple headspace sorptive extraction method coupled to gas chromatography-mass spectrometry for the determination of volatile compounds in macroalgae.

PubMed

Maruti, Astrid; Durán-Guerrero, Enrique; Barroso, Carmelo G; Castro, Remedios

2018-05-25

A novel extraction technique is proposed in which the Multiple Headspace Extraction (MHE) approach is used in conjunction with Headspace Sorptive Extraction (HSSE) and Gas Chromatography-Mass Spectrometry (GC-MS) detection. The extraction method was developed to determine volatile compounds in macroalgae. Optimization of the extraction parameters was carried out using design of experiments to identify factors that affect the extraction: extraction time, temperature, twister length and amount of sample. The results of the optimization led to an extraction of 2 g of sample using a 20 mm Twister ® at 66 °C for 180 min. The progression constants (β) were calculated for 43 volatile compounds, 29 of which could be quantified using the method. Linearity was attained with a determination coefficient higher than 0.99 for all studied compounds. Inter-day and inter-twister precisions ranged from 0.22% to 19.01% and from 0.69% to 14.76% respectively, and values below 10% were obtained for the majority of compounds. LOD and LOQ values ranged from the values obtained for diethyl succinate (0.012 μg/L and 0.088 μg/L, respectively) and those obtained for dimethyl sulfide (5.544 μg/L and 40.286 μg/L, respectively). However, for the majority of compounds values obtained were below 1 μg/L (LOD) and 5 μg/L (LOQ). Compounds such as ethyl acetate, hexanal, heptadecane, 2-hexenal, 6-methyl-5-hepten-2-one, dimethyl sulfide, benzyl alcohol, beta ionone, or beta cyclocitral, among others were correctly determined in three species of macroalgae: Ulva sp., Gracillaria sp. and Enteromorpha sp. Copyright © 2018 Elsevier B.V. All rights reserved.

Optimization of supercritical carbon dioxide extraction of Piper Betel Linn leaves oil and total phenolic content

NASA Astrophysics Data System (ADS)

Aziz, A. H. A.; Yunus, M. A. C.; Arsad, N. H.; Lee, N. Y.; Idham, Z.; Razak, A. Q. A.

2016-11-01

Supercritical Carbon Dioxide (SC-CO2) Extraction was applied to extract piper betel linn leaves. The piper betel leaves oil was used antioxidant, anti-diabetic, anticancer and antistroke. The aim of this study was to optimize the conditions of pressure, temperature and flowrate for oil yield and total phenolic content. The operational conditions of SC-CO2 studied were pressure (10, 20, 30 MPa), temperature (40, 60, 80 °C) and flowrate carbon dioxide (4, 6, 8 mL/min). The constant parameters were average particle size and extraction regime, 355pm and 3.5 hours respectively. First order polynomial expression was used to express the extracted oil while second order polynomial expression was used to express the total phenolic content and the both results were satisfactory. The best conditions to maximize the total extraction oil yields and total phenolic content were 30 MPa, 80 °C and 4.42 mL/min leading to 7.32% of oil and 29.72 MPa, 67.53 °C and 7.98 mL/min leading to 845.085 mg GAE/g sample. In terms of optimum condition with high extraction yield and high total phenolic content in the extracts, the best operating conditions were 30 MPa, 78 °C and 8 mL/min with 7.05% yield and 791.709 mg gallic acid equivalent (GAE)/g sample. The most dominant condition for extraction of oil yield and phenolic content were pressure and CO2 flowrate. The results show a good fit to the proposed model and the optimal conditions obtained were within the experimental range with the value of R2 was 96.13% for percentage yield and 98.52% for total phenolic content.

Parameters Identification for Photovoltaic Module Based on an Improved Artificial Fish Swarm Algorithm

PubMed Central

Wang, Hong-Hua

2014-01-01

A precise mathematical model plays a pivotal role in the simulation, evaluation, and optimization of photovoltaic (PV) power systems. Different from the traditional linear model, the model of PV module has the features of nonlinearity and multiparameters. Since conventional methods are incapable of identifying the parameters of PV module, an excellent optimization algorithm is required. Artificial fish swarm algorithm (AFSA), originally inspired by the simulation of collective behavior of real fish swarms, is proposed to fast and accurately extract the parameters of PV module. In addition to the regular operation, a mutation operator (MO) is designed to enhance the searching performance of the algorithm. The feasibility of the proposed method is demonstrated by various parameters of PV module under different environmental conditions, and the testing results are compared with other studied methods in terms of final solutions and computational time. The simulation results show that the proposed method is capable of obtaining higher parameters identification precision. PMID:25243233

Determination of well flat band condition in thin film FDSOI transistors using C-V measurement for accurate parameter extraction

NASA Astrophysics Data System (ADS)

Mohamad, B.; Leroux, C.; Reimbold, G.; Ghibaudo, G.

2018-01-01

For advanced gate stacks, effective work function (WFeff) and equivalent oxide thickness (EOT) are fundamental parameters for technology optimization. On FDSOI transistors, and contrary to the bulk technologies, while EOT can still be extracted at strong inversion from the typical gate-to-channel capacitance (Cgc), it is no longer the case for WFeff due to the disappearance of an observable flat band condition on capacitance characteristics. In this work, a new experimental method, the Cbg(VBG) characteristic, is proposed in order to extract the well flat band condition (VFB, W). This characteristic enables an accurate and direct evaluation of WFeff. Moreover, using the previous extraction of the gate oxide (tfox), and buried oxide (tbox) from typical capacitance characteristics (Cgc and Cbc), it allows the extraction of the channel thickness (tch). Furthermore, the measurement of the well flat band condition on Cbg(VBG) characteristics for two different Si and SiGe channel also proves the existence of a dipole at the SiGe/SiO2 interface.

Development of a Matrix Solid-Phase Dispersion Extraction Combined with UPLC/Q-TOF-MS for Determination of Phenolics and Terpenoids from the Euphorbia fischeriana.

PubMed

Li, Wenjing; Lin, Yu; Wang, Yuchun; Hong, Bo

2017-09-11

A method based on a simplified extraction by matrix solid phase dispersion (MSPD) followed by ultra-performance liquid chromatography coupled with the quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS) determination is validated for analysis of two phenolics and three terpenoids in Euphorbia fischeriana . The optimized experimental parameters of MSPD including dispersing sorbent (silica gel), ratio of sample to dispersing sorbent (1:2), elution solvent (water-ethanol: 30-70) and volume of the elution solvent (10 mL) were examined and set down. The highest extraction yields of chromatogram information and the five compounds were obtained under the optimized conditions. A total of 25 constituents have been identified and five components have been quantified from Euphorbia fischeriana . A linear relationship (r² ≥ 0.9964) between the concentrations and the peak areas of the mixed standard substances were revealed. The average recovery was between 92.4% and 103.2% with RSD values less than 3.45% ( n = 5). The extraction yields of two phenolics and three terpenoids obtained by the MSPD were higher than those of traditional reflux and sonication extraction with reduced requirement on sample, solvent and time. In addition, the optimized method will be applied for analyzing terpenoids in other Chinese herbal medicine samples.

Slow-injection ultrasound-assisted emulsification-microextraction for determination of phthalate esters in water.

PubMed

Li, Songqing; Li, Tong; Gao, Peng; Lu, Runhua; Zhou, Wenfeng; Gao, Haixiang

2014-10-01

A type of ultrasound-assisted emulsification-microextraction (USAEME) was applied for the extraction and determination of four phthalate esters (e.g., dimethyl phthalate, diethyl phthalate, dibutyl phthalate and benzyl butyl phthalate) in aqueous samples prior to quantification using HPLC-UV. The simultaneous injection of the extraction solvent and ultrasonication of the mixture results in an efficient extraction with the extractant well-dispersed in the sample. The parameters affecting the experimental results were analyzed and optimized through the design of the experiment. Using a central composite face-centered design, the results of 28 experimental data points were analyzed and validated. An optimal set of operating conditions was obtained using 40 μL of 1,1,2,2-tetrachloroethane and 1% NaCl subjected to 2.0 min of ultrasonication under natural pH. Under optimized conditions, the extractions resulted in analyte recoveries of 75-87% and high enrichment factors of 356-415. The calibration curves were linear, and the correlation coefficients ranged from 0.9992 to 0.9997 at concentrations of 5 to 300 μg L(-1). The RSDs (n = 5) were 5.6-7.9%. The limits of detection for the four phthalate esters ranged from 0.26 to 1.46 μg L(-1). © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Speciation of organotin compounds in urine by GC-MIP-AED and GC-MS after ethylation and liquid-liquid extraction.

PubMed

Zachariadis, G A; Rosenberg, E

2009-04-15

A method for the determination of organotin compounds in urine samples based on liquid-liquid extraction (LLE) in hexane and gas chromatographic separation was developed and optimized. Seven organotin species, namely monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), tetrabutyltin (TeBT), monophenyltin (MPhT), diphenyltin (DPhT) and triphenyltin (TPhT), were in situ derivatized by sodium tetraethylborate (NaBEt(4)) to form ethylated less polar derivatives directly in the urine matrix. The critical parameters which have a significant effect on the yield of the successive liquid-liquid extraction procedure were examined, by using standard solutions of tetrabutyltin in hexane. The method was optimized for use in direct analysis of undiluted human urine samples and ways to overcome practical problems such as foam formation during extraction, due to various constituents of urine are discussed. After thorough optimization of the extraction procedure, all examined species could be determined after 3 min of simultaneous derivatization and extraction at room temperature and 5 min phase separation by centrifugation. Gas chromatography with a microwave-induced plasma atomic emission detector (MIP-AED) as element specific detector was employed for quantitative measurements, while a quadrupole mass spectrometric detector (MS) was used as molecular specific detector. The detection limits were between 0.42 and 0.67 microg L(-1) (as Sn) for the quantitative LLE-GC-MIP-AED method and the precision between 4.2% and 11.7%, respectively.

Light-extraction enhancement for light-emitting diodes: a firefly-inspired structure refined by the genetic algorithm

NASA Astrophysics Data System (ADS)

Bay, Annick; Mayer, Alexandre

2014-09-01

The efficiency of light-emitting diodes (LED) has increased significantly over the past few years, but the overall efficiency is still limited by total internal reflections due to the high dielectric-constant contrast between the incident and emergent media. The bioluminescent organ of fireflies gave incentive for light-extraction enhance-ment studies. A specific factory-roof shaped structure was shown, by means of light-propagation simulations and measurements, to enhance light extraction significantly. In order to achieve a similar effect for light-emitting diodes, the structure needs to be adapted to the specific set-up of LEDs. In this context simulations were carried out to determine the best geometrical parameters. In the present work, the search for a geometry that maximizes the extraction of light has been conducted by using a genetic algorithm. The idealized structure considered previously was generalized to a broader variety of shapes. The genetic algorithm makes it possible to search simultaneously over a wider range of parameters. It is also significantly less time-consuming than the previous approach that was based on a systematic scan on parameters. The results of the genetic algorithm show that (1) the calculations can be performed in a smaller amount of time and (2) the light extraction can be enhanced even more significantly by using optimal parameters determined by the genetic algorithm for the generalized structure. The combination of the genetic algorithm with the Rigorous Coupled Waves Analysis method constitutes a strong simulation tool, which provides us with adapted designs for enhancing light extraction from light-emitting diodes.

Improved model reduction and tuning of fractional-order PI(λ)D(μ) controllers for analytical rule extraction with genetic programming.

PubMed

Das, Saptarshi; Pan, Indranil; Das, Shantanu; Gupta, Amitava

2012-03-01

Genetic algorithm (GA) has been used in this study for a new approach of suboptimal model reduction in the Nyquist plane and optimal time domain tuning of proportional-integral-derivative (PID) and fractional-order (FO) PI(λ)D(μ) controllers. Simulation studies show that the new Nyquist-based model reduction technique outperforms the conventional H(2)-norm-based reduced parameter modeling technique. With the tuned controller parameters and reduced-order model parameter dataset, optimum tuning rules have been developed with a test-bench of higher-order processes via genetic programming (GP). The GP performs a symbolic regression on the reduced process parameters to evolve a tuning rule which provides the best analytical expression to map the data. The tuning rules are developed for a minimum time domain integral performance index described by a weighted sum of error index and controller effort. From the reported Pareto optimal front of the GP-based optimal rule extraction technique, a trade-off can be made between the complexity of the tuning formulae and the control performance. The efficacy of the single-gene and multi-gene GP-based tuning rules has been compared with the original GA-based control performance for the PID and PI(λ)D(μ) controllers, handling four different classes of representative higher-order processes. These rules are very useful for process control engineers, as they inherit the power of the GA-based tuning methodology, but can be easily calculated without the requirement for running the computationally intensive GA every time. Three-dimensional plots of the required variation in PID/fractional-order PID (FOPID) controller parameters with reduced process parameters have been shown as a guideline for the operator. Parametric robustness of the reported GP-based tuning rules has also been shown with credible simulation examples. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

[Biooxidation of gold-bearing sulfide ore and subsequent biological treatment of cyanidation residues].

PubMed

Kanaev, A T; Bulaev, A G; Semenchenko, G V; Kanaeva, Z K; Shilmanova, A A

2016-01-01

The percolation biooxidation parameters of ore from the Bakyrchik deposit were studied. An investigation of the technological parameters (such as the concentration of leaching agents, irrigation intensity, and pauses at various stages of the leaching) revealed the optimal mode for precious metal extraction. The stages of the ore processing were biooxidation, gold extraction by cyanidation or thiosulfate leaching, and biological destruction of cyanide. The gold and silver recovery rates by cyanidation were 64.0 and 57.3%, respectively. The gold and silver recovery rates by thiosulfate leaching were 64.0 and 57.3%, respectively. Gold and silver recovery rates from unoxidized ore (control experiment) by cyanidation were 20.9 and 26.8%, respectively. Thiosulfate leaching of unoxidized ore allowed the extraction of 38.8 and 24.2% of the gold and silver, respectively. Cyanidation residues were treated with bacteria of the genus Alcaligenes in order to destruct cyanide.

Integrated microwave processing system for the extraction of organophosphorus pesticides in fresh vegetables.

PubMed

Wu, Lijie; Song, Ying; Hu, Mingzhu; Xu, Xu; Zhang, Hanqi; Yu, Aimin; Ma, Qiang; Wang, Ziming

2015-03-01

A simple and efficient integrated microwave processing system (IMPS) was firstly assembled and validated for the extraction of organophosphorus pesticides in fresh vegetables. Two processes under microwave irradiation, dynamic microwave-assisted extraction (DMAE) and microwave-accelerated solvent elution (MASE), were integrated for simplifying the pretreatment of the sample. Extraction, separation, enrichment and elution were finished in a simple step. The organophosphorus pesticides were extracted from the fresh vegetables into hexane with DMAE, and then the extract was directly introduced into the enrichment column packed with active carbon fiber (ACF). Subsequently, the organophosphorus pesticides trapped on the ACF were eluted with ethyl acetate under microwave irradiation. No further filtration or cleanup was required before analysis of the eluate by gas chromatography-mass spectrometry. Some experimental parameters affecting extraction efficiency were investigated and optimized, such as microwave output power, kind and volume of extraction solvent, extraction time, amount of sorbent, elution microwave power, kind and volume of elution solvent, elution solvent flow rate. Under the optimized conditions, the recoveries were in the range of 71.5-105.2%, and the relative standard deviations were lower than 11.6%. The experiment results prove that the present method is a simple and effective sample preparation method for the determination of pesticides in solid samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Fabrication of a novel hydrophobic/ion-exchange mixed-mode adsorbent for the dispersive solid-phase extraction of chlorophenols from environmental water samples.

PubMed

Gao, Li; Wei, Yinmao

2016-08-01

A novel mixed-mode adsorbent was prepared by functionalizing silica with tris(2-aminoethyl)amine and 3-phenoxybenzaldehyde as the main mixed-mode scaffold due to the presence of the plentiful amino groups and benzene rings in their molecules. The adsorption mechanism was probed with acidic, natural and basic compounds, and the mixed hydrophobic and ion-exchange interactions were found to be responsible for the adsorption of analytes. The suitability of dispersive solid-phase extraction was demonstrated in the determination of chlorophenols in environmental water. Several parameters, including sample pH, desorption solvent, ionic strength, adsorbent dose, and extraction time were optimized. Under the optimal extraction conditions, the proposed dispersive solid-phase extraction coupled with high-performance liquid chromatography showed good linearity range and acceptable limits of detection (0.22∽0.54 ng/mL) for five chlorophenols. Notably, the higher extraction recoveries (88.7∽109.7%) for five chlorophenols were obtained with smaller adsorbent dose (10 mg) and shorter extraction time (15 min) compared with the reported methods. The proposed method might be potentially applied in the determination of trace chlorophenols in real water samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimization of extraction parameters by using response surface methodology, purification, and identification of anthocyanin pigments in Melastoma malabathricum fruit.

PubMed

Anuar, Nordiyanah; Mohd Adnan, Ahmad Faris; Saat, Naziz; Aziz, Norkasmani; Mat Taha, Rosna

2013-01-01

Anthocyanins not just have various benefits in food industry but also have been used as natural colourants in cosmetic, coating products and as potential natural photosensitizers in solar cell. Thus, the main purpose of this study was to obtain information on the maximum yield of anthocyanin that can be recovered from Melastoma malabathricum fruit. Factors such as extraction temperature, extraction time, and solid to liquid ratio were identified to be significantly affecting anthocyanin extraction efficiency. By using three-level three-factor Box-Behnken design, the optimized conditions for anthocyanin extraction by acidified methanol (R (2) = 0.972) were temperature of 60°C, time of 86.82 min, and 0.5 : 35 (g/mL) solid to liquid ratio while the optimum extraction conditions by acidified ethanol (R (2) = 0.954) were temperature of 60°C, time of 120 min, and 0.5 : 23.06 (g/mL) solid to liquid ratio. The crude anthocyanin extract was further purified by using Amberlite XAD-7 and Sephadex LH-20 column chromatography. Identification of anthocyanins revealed the presence of cyanidin dihexoside, cyanidin hexoside, and delphinidin hexoside as the main anthocyanins in M. malabathricum fruit.

Optimization of extraction parameters on the antioxidant properties of banana waste.

PubMed

Toh, Pui Yee; Leong, Fei Shan; Chang, Sui Kiat; Khoo, Hock Eng; Yim, Hip Seng

2016-01-01

Banana is grown worldwide and consumed as ripe fruit or used for culinary purposes. Peels form about 18-33% of the whole fruit and are discarded as a waste product. With a view to exploiting banana peel as a source of valuable compounds, this study was undertaken to evaluate the effect of different extraction parameters on the antioxidant activities of the industrial by-product of banana waste (peel). Influence of different extraction parameters such as types of solvent, percentages of solvent, and extraction times on total phenolic content (TPC) and antioxidant activity of mature and green peels of Pisang Abu (PA), Pisang Berangan (PB), and Pisang Mas (PM) were investigated. The best extraction parameters were initially selected based on different percentages of ethanol (0-100% v/v), extraction time (1-5 hr), and extraction temperature (25-60°C) for extraction of antioxidants in the banana peels. Total phenolic content (TPC) was evaluated using Folin-Ciocalteu reagent assay while antioxidant activities (AA) of banana peel were accessed by DPPH, ABTS, and β-carotene bleaching (BCB) assays at optimum extraction conditions. Based on different extraction solvents and percentages of solvents used, 70% and 90% of acetone had yielded the highest TPC for the mature and green PA peels, respectively; 90% of ethanol and methanol has yielded the highest TPC for the mature and green PB peels, respectively; while 90% ethanol for the mature and green PM peels. Similar extraction conditions were found for the antioxidant activities for the banana peel assessed using DPPH assay except for green PB peel, which 70% methanol had contributed to the highest AA. Highest TPC and AA were obtained by applying 4, 1, and 2 hrs extraction for the peels of PA, PB and PM, respectively. The best extraction conditions were also used for determination of AAs using ABTS and β-carotene bleaching assays. Therefore, the best extraction conditions used have given the highest TPC and AAs. By-products of banana (peel) can be considered as a potential source of antioxidants in food and pharmaceutical industry.

Modeling and optimization of lime-based stabilization in high alkaline arsenic-bearing sludges with a central composite design.

PubMed

Lei, Jie; Peng, Bing; Min, Xiaobo; Liang, Yanjie; You, Yang; Chai, Liyuan

2017-04-16

This study focuses on the modeling and optimization of lime-based stabilization in high alkaline arsenic-bearing sludges (HAABS) and describes the relationship between the arsenic leachate concentration (ALC) and stabilization parameters to develop a prediction model for obtaining the optimal process parameters and conditions. A central composite design (CCD) along with response surface methodology (RSM) was conducted to model and investigate the stabilization process with three independent variables: the Ca/As mole ratio, reaction time and liquid/solid ratio, along with their interactions. The obvious characteristic changes of the HAABS before and after stabilization were verified by X-ray diffraction (XRD), scanning electron microscopy (SEM), particle size distribution (PSD) and the community bureau of reference (BCR) sequential extraction procedure. A prediction model Y (ALC) with a statistically significant P-value <0.01 and high correlation coefficient R 2 = 93.22% was obtained. The optimal parameters were successfully predicted by the model for the minimum ALC of 0.312 mg/L, which was validated with the experimental result (0.306 mg/L). The XRD, SEM and PSD results indicated that crystal calcium arsenate Ca 5 (AsO 4 ) 3 OH and Ca 4 (OH) 2 (AsO 4 ) 2 ·4H 2 O formation played an important role in minimizing the ALC. The BCR sequential extraction results demonstrated that the treated HAABS were stable in a weak acidic environment for a short time but posed a potential environmental risk after a long time. The results clearly confirm that the proposed three-factor CCD is an effective approach for modeling the stabilization of HAABS. However, further solidification technology is suggested for use after lime-based stabilization treatment of arsenic-bearing sludges.

Quantifying properties of hot and dense QCD matter through systematic model-to-data comparison

DOE PAGES

Bernhard, Jonah E.; Marcy, Peter W.; Coleman-Smith, Christopher E.; ...

2015-05-22

We systematically compare an event-by-event heavy-ion collision model to data from the CERN Large Hadron Collider. Using a general Bayesian method, we probe multiple model parameters including fundamental quark-gluon plasma properties such as the specific shear viscosity η/s, calibrate the model to optimally reproduce experimental data, and extract quantitative constraints for all parameters simultaneously. Furthermore, the method is universal and easily extensible to other data and collision models.

A fast and efficient method for device level layout analysis

NASA Astrophysics Data System (ADS)

Dong, YaoQi; Zou, Elaine; Pang, Jenny; Huang, Lucas; Yang, Legender; Zhang, Chunlei; Du, Chunshan; Hu, Xinyi; Wan, Qijian

2017-03-01

There is an increasing demand for device level layout analysis, especially as technology advances. The analysis is to study standard cells by extracting and classifying critical dimension parameters. There are couples of parameters to extract, like channel width, length, gate to active distance, and active to adjacent active distance, etc. for 14nm technology, there are some other parameters that are cared about. On the one hand, these parameters are very important for studying standard cell structures and spice model development with the goal of improving standard cell manufacturing yield and optimizing circuit performance; on the other hand, a full chip device statistics analysis can provide useful information to diagnose the yield issue. Device analysis is essential for standard cell customization and enhancements and manufacturability failure diagnosis. Traditional parasitic parameters extraction tool like Calibre xRC is powerful but it is not sufficient for this device level layout analysis application as engineers would like to review, classify and filter out the data more easily. This paper presents a fast and efficient method based on Calibre equation-based DRC (eqDRC). Equation-based DRC extends the traditional DRC technology to provide a flexible programmable modeling engine which allows the end user to define grouped multi-dimensional feature measurements using flexible mathematical expressions. This paper demonstrates how such an engine and its programming language can be used to implement critical device parameter extraction. The device parameters are extracted and stored in a DFM database which can be processed by Calibre YieldServer. YieldServer is data processing software that lets engineers query, manipulate, modify, and create data in a DFM database. These parameters, known as properties in eqDRC language, can be annotated back to the layout for easily review. Calibre DesignRev can create a HTML formatted report of the results displayed in Calibre RVE which makes it easy to share results among groups. This method has been proven and used in SMIC PDE team and SPICE team.

Mapping of an ultrasonic bath for ultrasound assisted extraction of mangiferin from Mangifera indica leaves.

PubMed

Kulkarni, Vrushali M; Rathod, Virendra K

2014-03-01

The present work deals with the mapping of an ultrasonic bath for the maximum extraction of mangiferin from Mangifera indica leaves. I3(-) liberation experiments (chemical transformations) and extraction (physical transformations) were carried out at different locations in an ultrasonic bath and compared. The experimental findings indicated a similar trend in variation in an ultrasonic bath by both these methods. Various parameters such as position and depth of vessel in an ultrasonic bath, diameter and shape of a vessel, frequency and input power which affect the extraction yield have been studied in detail. Maximum yield of mangiferin obtained was approximately 31 mg/g at optimized parameters: distance of 2.54 cm above the bottom of the bath, 7 cm diameter of vessel, flat bottom vessel, 6.35 cm liquid height, 122 W input power and 25 kHz frequency. The present work indicates that the position and depth of vessel in an ultrasonic bath, diameter and shape of a vessel, frequency and input power have significant effect on the extraction yield. This work can be used as a base for all ultrasonic baths to obtain maximum efficiency for ultrasound assisted extraction. Copyright © 2013 Elsevier B.V. All rights reserved.

Impact of Extraction Parameters on the Recovery of Lipolytic Activity from Fermented Babassu Cake

PubMed Central

Silva, Jaqueline N.; Godoy, Mateus G.; Gutarra, Melissa L. E.; Freire, Denise M. G.

2014-01-01

Enzyme extraction from solid matrix is as important step in solid-state fermentation to obtain soluble enzymes for further immobilization and application in biocatalysis. A method for the recovery of a pool of lipases from Penicillium simplicissimum produced by solid-state fermentation was developed. For lipase recovery different extraction solution was used and phosphate buffer containing Tween 80 and NaCl showed the best results, yielding lipase activity of 85.7 U/g and 65.7 U/g, respectively. The parameters with great impacts on enzyme extraction detected by the Plackett-Burman analysis were studied by Central Composite Rotatable experimental designs where a quadratic model was built showing maximum predicted lipase activity (160 U/g) at 25°C, Tween 80 0.5% (w/v), pH 8.0 and extraction solution 7 mL/g, maintaining constant buffer molarity of 0.1 M and 200 rpm. After the optimization process a 2.5 fold increase in lipase activity in the crude extract was obtained, comparing the intial value (64 U/g) with the experimental design (160 U/g), thus improving the overall productivity of the process. PMID:25090644

Negative-pressure cavitation extraction for the determination of flavonoids in pigeon pea leaves by liquid chromatography-tandem mass spectrometry.

PubMed

Liu, Wei; Fu, Yujie; Zu, Yuangang; Kong, Yu; Zhang, Lin; Zu, Baishi; Efferth, Thomas

2009-05-01

A new method, namely negative-pressure cavitation extraction (NPCE), followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) is presented for the extraction and quantification of flavonoids in pigeon pea leaves. This method combines the high efficiency of NPCE and the sensitivity and accuracy of MS/MS. The influential parameters of the NPCE procedure including liquid/solid ratio, extraction time, nitrogen flow and number of extraction cycles were optimized. Under optimized conditions, the efficiency of NPCE for extracting five flavonoids was compared to microwave-assisted extraction (MAE), ultrasonic extraction (USE) and heating reflux extraction (HRE). Additionally, structural disruption to pigeon pea leaves samples with different extraction methods was investigated by scanning electron microscopy. The relative recovery with NPCE was equivalent to or higher than that with USE and obviously higher than those with MAE and HRE which are usually conducted in higher temperatures. Furthermore, because NPCE was performed with nitrogen at room temperature, the degradation and oxidation of analytes were avoided. In addition, the NPCE method was validated in terms of repeatability and reproducibility, relative standard deviation for relative recovery was lower than 5.84 and 8.83%, respectively. The method was also successfully applied for the quantification of five flavonoids in pigeon pea leaves. All these results suggest that the developed NPCE-LC-MS/MS method represents an excellent alternative for the extraction and quantification of flavonoids in other plant materials.

Parametric modeling and stagger angle optimization of an axial flow fan

NASA Astrophysics Data System (ADS)

Li, M. X.; Zhang, C. H.; Liu, Y.; Y Zheng, S.

2013-12-01

Axial flow fans are widely used in every field of social production. Improving their efficiency is a sustained and urgent demand of domestic industry. The optimization of stagger angle is an important method to improve fan performance. Parametric modeling and calculation process automation are realized in this paper to improve optimization efficiency. Geometric modeling and mesh division are parameterized based on GAMBIT. Parameter setting and flow field calculation are completed in the batch mode of FLUENT. A control program is developed in Visual C++ to dominate the data exchange of mentioned software. It also extracts calculation results for optimization algorithm module (provided by Matlab) to generate directive optimization control parameters, which as feedback are transferred upwards to modeling module. The center line of the blade airfoil, based on CLARK y profile, is constructed by non-constant circulation and triangle discharge method. Stagger angles of six airfoil sections are optimized, to reduce the influence of inlet shock loss as well as gas leak in blade tip clearance and hub resistance at blade root. Finally an optimal solution is obtained, which meets the total pressure requirement under given conditions and improves total pressure efficiency by about 6%.

Homogenization-assisted cavitation hybrid rotation extraction and macroporous resin enrichment of dihydroquercetin from Larix gmelinii.

PubMed

Xia, Yu; Wang, Yinhang; Li, Wei; Ma, Chunhui; Liu, Shouxin

2017-12-01

Cavitation hybrid rotation, which was and is still looked upon as an unavoidable nuisance in the flow systems, for extraction processing intensification of active chemical compounds from natural products. In this study, a homogenization-assisted cavitation hybrid rotation extraction method was applied to extract dihydroquercetin (DHQ) from larch (Larix gmelinii) wood root. The extraction parameters were optimized in single factor experiments with the DHQ extraction yields as the response values. The optimum conditions were as follows: number of extractions, three; ethanol volume fraction for the extraction, 60%; liquid-solid ratio for homogenization, 10mL/g; homogenization time, 8min; liquid-solid ratio for cavitation extraction, 9mL/g, and cavitation extraction time, 35min. Under these conditions, the DHQ content in extract was 4.50±0.02mg/g, and the extraction efficiency was higher than those of traditional techniques. Cavitation can be effectively used to improve the extraction rate by increasing the mass transfer rates and possible rupture of cell wall due to formation of microcavities leading to higher product yields with reduced processing time and solvent consumption. After the extraction process, macroporous resin column chromatography was used to concentrate and purify the DHQ. Three resins were selected from fifteen macroporous resins for further investigation of their performance. Among these resins, AB-8 resin exhibited relatively better adsorption capacities and desorption ratios for DHQ. The ethanol volume fraction of the solutions for sample loading and desorption, and flow rates for loading and desorption were optimized for the macroporous resin column chromatography. Copyright © 2017 Elsevier B.V. All rights reserved.

Subthreshold SPICE Model Optimization

NASA Astrophysics Data System (ADS)

Lum, Gregory; Au, Henry; Neff, Joseph; Bozeman, Eric; Kamin, Nick; Shimabukuro, Randy

2011-04-01

The first step in integrated circuit design is the simulation of said design in software to verify proper functionally and design requirements. Properties of the process are provided by fabrication foundries in the form of SPICE models. These SPICE models contain the electrical data and physical properties of the basic circuit elements. A limitation of these models is that the data collected by the foundry only accurately model the saturation region. This is fine for most users, but when operating devices in the subthreshold region they are inadequate for accurate simulation results. This is why optimizing the current SPICE models to characterize the subthreshold region is so important. In order to accurately simulate this region of operation, MOSFETs of varying widths and lengths are fabricated and the electrical test data is collected. From the data collected the parameters of the model files are optimized through parameter extraction rather than curve fitting. With the completed optimized models the circuit designer is able to simulate circuit designs for the sub threshold region accurately.

Enrichment of copper and recycling of cyanide from copper-cyanide waste by solvent extraction

NASA Astrophysics Data System (ADS)

Gao, Teng-yue; Liu, Kui-ren; Han, Qing; Xu, Bin-shi

2016-11-01

The enrichment of copper from copper-cyanide wastewater by solvent extraction was investigated using a quaternary ammonium salt as an extractant. The influences of important parameters, e.g., organic-phase components, aqueous pH values, temperature, inorganic anion impurities, CN/Cu molar ratio, and stripping reagents, were examined systematically, and the optimal conditions were determined. The results indicated that copper was effectively concentrated from low-concentration solutions using Aliquat 336 and that the extraction efficiency increased linearly with increasing temperature. The aqueous pH value and concentrations of inorganic anion impurities only weakly affected the extraction process when varied in appropriate ranges. The CN/Cu molar ratio affected the extraction efficiency by changing the distribution of copper-cyanide complexes. The difference in gold leaching efficiency between using raffinate and fresh water was negligible.

Ultrasound-assisted extraction and purification of schisandrin B from Schisandra chinensis (Turcz.) Baill seeds: optimization by response surface methodology.

PubMed

Zhang, Y B; Wang, L H; Zhang, D Y; Zhou, L L; Guo, Y X

2014-03-01

The objective of this study is to develop a process consisting of ultrasonic-assisted extraction, silica-gel column chromatography and crystallization to optimize pilot scale recovery of schisandrin B (SAB) from Schisandra chinensis seeds. The effects of five independent variables including liquid-solid ratio, ethanol concentration, ultrasonic power, extraction time, and temperature on the SAB yield were evaluated with fractional factorial design (FFD). The FFD results showed that the ethanol concentration was the only significant factor for the yield of SAB. Then, with the liquid-solid ratio 5 (mL/g) and ultrasonic power 600 W, the other three parameters were further optimized by means of response surface methodology (RSM). The RSM results revealed that the optimal conditions consisted of 95% ethanol, 60 °C and 70 min. The average experimental SAB yield under the optimum conditions was found to be 5.80 mg/g, which was consistent with the predicted value of 5.83 mg/g. Subsequently, a silica gel chromatographic process was used to prepare the SAB-enriched extract with petroleum ether/acetone (95:5, v/v) as eluents. After final crystallization, 1.46 g of SAB with the purity of 99.4% and the overall recovery of 57.1% was obtained from 400 g seeds powder. This method provides an efficient and low-cost way for SAB purification for pharmaceutical industrial applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Parallel optimization of signal detection in active magnetospheric signal injection experiments

NASA Astrophysics Data System (ADS)

Gowanlock, Michael; Li, Justin D.; Rude, Cody M.; Pankratius, Victor

2018-05-01

Signal detection and extraction requires substantial manual parameter tuning at different stages in the processing pipeline. Time-series data depends on domain-specific signal properties, necessitating unique parameter selection for a given problem. The large potential search space makes this parameter selection process time-consuming and subject to variability. We introduce a technique to search and prune such parameter search spaces in parallel and select parameters for time series filters using breadth- and depth-first search strategies to increase the likelihood of detecting signals of interest in the field of magnetospheric physics. We focus on studying geomagnetic activity in the extremely and very low frequency ranges (ELF/VLF) using ELF/VLF transmissions from Siple Station, Antarctica, received at Québec, Canada. Our technique successfully detects amplified transmissions and achieves substantial speedup performance gains as compared to an exhaustive parameter search. We present examples where our algorithmic approach reduces the search from hundreds of seconds down to less than 1 s, with a ranked signal detection in the top 99th percentile, thus making it valuable for real-time monitoring. We also present empirical performance models quantifying the trade-off between the quality of signal recovered and the algorithm response time required for signal extraction. In the future, improved signal extraction in scenarios like the Siple experiment will enable better real-time diagnostics of conditions of the Earth's magnetosphere for monitoring space weather activity.

Measurement system for 3-D foot coordinates and parameters

NASA Astrophysics Data System (ADS)

Liu, Guozhong; Li, Yunhui; Wang, Boxiong; Shi, Hui; Luo, Xiuzhi

2008-12-01

The 3-D foot-shape measurement system based on laser-line-scanning principle and the model of the measurement system were presented. Errors caused by nonlinearity of CCD cameras and caused by installation can be eliminated by using the global calibration method for CCD cameras, which based on nonlinear coordinate mapping function and the optimized method. A local foot coordinate system is defined with the Pternion and the Acropodion extracted from the boundaries of foot projections. The characteristic points can thus be located and foot parameters be extracted automatically by the local foot coordinate system and the related sections. Foot measurements for about 200 participants were conducted and the measurement results for male and female participants were presented. 3-D foot coordinates and parameters measurement makes it possible to realize custom-made shoe-making and shows great prosperity in shoe design, foot orthopaedic treatment, shoe size standardization, and establishment of a feet database for consumers.

Deep sulcal landmarks: algorithmic and conceptual improvements in the definition and extraction of sulcal pits.

PubMed

Auzias, G; Brun, L; Deruelle, C; Coulon, O

2015-05-01

Recent interest has been growing concerning points of maximum depth within folds, the sulcal pits, that can be used as reliable cortical landmarks. These remarkable points on the cortical surface are defined algorithmically as the outcome of an automatic extraction procedure. The influence of several crucial parameters of the reference technique (Im et al., 2010) has not been evaluated extensively, and no optimization procedure has been proposed so far. Designing an appropriate optimization framework for these parameters is mandatory to guarantee the reproducibility of results across studies and to ensure the feasibility of sulcal pit extraction and analysis on large cohorts. In this work, we propose a framework specifically dedicated to the optimization of the parameters of the method. This optimization framework relies on new measures for better quantifying the reproducibility of the number of sulcal pits per region across individuals, in line with the assumptions of one-to-one correspondence of sulcal roots across individuals which is an explicit aspect of the sulcal roots model (Régis et al., 2005). Our procedure benefits from a combination of improvements, including the use of a convenient sulcal depth estimation and is methodologically sound. Our experiments on two different groups of individuals, with a total of 137 subjects, show an increased reliability across subjects in deeper sulcal pits, as compared to the previous approach, and cover the entire cortical surface, including shallower and more variable folds that were not considered before. The effectiveness of our method ensures the feasibility of a systematic study of sulcal pits on large cohorts. On top of these methodological advances, we quantify the relationship between the reproducibility of the number of sulcal pits per region across individuals and their respective depth and demonstrate the relatively high reproducibility of several pits corresponding to shallower folds. Finally, we report new results regarding the local pit asymmetry, providing evidence that the algorithmic and conceptual approach defended here may contribute to better understanding of the key role of sulcal pits in neuroanatomy. Copyright © 2015 Elsevier Inc. All rights reserved.

Three phases hollow fiber LPME combined with HPLC-UV for extraction, preconcentration and determination of valerenic acid in Valeriana officinalis.

PubMed

Mirzaei, Mohamad; Dinpanah, Hossein

2011-07-01

In the present work, the applicability of hollow fiber-based liquid phase microextraction (HF-LPME) was evaluated for the extraction and preconcentration of valerenic acid prior to its determination by reversed-phase HPLC/UV. The target drug was extracted from 5.0 mL of aqueous solution with pH 3.5 into an organic extracting solvent (dihexyl ether) impregnated in the pores of a hollow fiber and finally back extracted into 10 μ L of aqueous solution with pH 9.5 located inside the lumen of the hollow fiber. In order to obtain high extraction efficiency, the parameters affecting the HF-LPME, including pH of the donor and acceptor phases, type of organic phase, ionic strength, the volume ratio of donor to acceptor phase, stirring rate and extraction time were studied and optimized. Under the optimized conditions, enrichment factor up to 446 was achieved and the relative standard deviation (RSD) of the method was 4.36% (n = 9). The linear range was 7.5-850 μg L⁻¹ with correlation coefficient (r²=0.999), detection limits was 2.5 μg L⁻¹ and the LOQ was 7.5 μg L⁻¹. The proposed method was evaluated by extraction and determination of valerenic acid in some Iranian wild species of Valerianaceae. Copyright © 2011 Elsevier B.V. All rights reserved.

Development and biological evaluation of Gymnema sylvestre extract-loaded nonionic surfactant-based niosomes.

PubMed

Kamble, Bhagyashree; Talreja, Seema; Gupta, Ankur; Patil, Dada; Pathak, Deepa; Moothedath, Ismail; Duraiswamy, Basavan

2013-08-01

To develop and characterize Gymnema sylvestre extract-loaded niosomes using nonionic surfactants, and to evaluate their antihyperglycemic efficacy in comparison with the parent extract. Nonionic surfactant-based G. sylvestre extract-loaded niosomes were prepared using the thin-film hydration method. The optimized formulation was screened for entrapment efficiency of the constituents, as well as other parameters such as release kinetics, vesicle size, zeta-potential and stability studies. The parent extract and optimized niosomal formulation were evaluated for their antihyperglycemic potential in an alloxan-induced diabetic animal model. Niosomes prepared using Span™ 40 (SD Fine Chemicals Ltd, Mumbai, India) provided sterically stable vesicles 229.5 nm in size with zeta-potential and entrapment efficiency of 150.86 mV and 85.3 ± 4.5%, respectively. The surface morphology of vesicles was confirmed to be spherical by scanning electron microscopy studies. An in vitro release study demonstrated 77.4% of phytoconstituents release within 24 h. The niosome formulation demonstrated significant blood glucose level reduction in an oral glucose tolerance test, and increased antihyperglycemic activity compared with the parent extract in an alloxan-induced diabetic model. This study reveals the merits of G. sylvestre extract-loaded niosomes, and justifies the potential of niosomes for improving the efficacy of G. sylvestre extract as antidiabetic. Original submitted 30 March 2012; Revised submitted 29 August 2012; Published online 24 December 2012.

IOTA: integration optimization, triage and analysis tool for the processing of XFEL diffraction images.

PubMed

Lyubimov, Artem Y; Uervirojnangkoorn, Monarin; Zeldin, Oliver B; Brewster, Aaron S; Murray, Thomas D; Sauter, Nicholas K; Berger, James M; Weis, William I; Brunger, Axel T

2016-06-01

Serial femtosecond crystallography (SFX) uses an X-ray free-electron laser to extract diffraction data from crystals not amenable to conventional X-ray light sources owing to their small size or radiation sensitivity. However, a limitation of SFX is the high variability of the diffraction images that are obtained. As a result, it is often difficult to determine optimal indexing and integration parameters for the individual diffraction images. Presented here is a software package, called IOTA , which uses a grid-search technique to determine optimal spot-finding parameters that can in turn affect the success of indexing and the quality of integration on an image-by-image basis. Integration results can be filtered using a priori information about the Bravais lattice and unit-cell dimensions and analyzed for unit-cell isomorphism, facilitating an improvement in subsequent data-processing steps.

Extraction of Natural Antioxidants from the Thelephora ganbajun Mushroom by an Ultrasound-Assisted Extraction Technique and Evaluation of Antiproliferative Activity of the Extract against Human Cancer Cells.

PubMed

Xu, Dong-Ping; Zheng, Jie; Zhou, Yue; Li, Ya; Li, Sha; Li, Hua-Bin

2016-10-01

The Thelephora ganbajun mushroom has been found to be a potential rich source of natural antioxidants. In this study, an ultrasound-assisted extraction (UAE) technique together with GRAS (generally recognized as safe) solvents (ethanol and water) was used to maximize the extraction of antioxidants from Thelephora ganbajun . Five extraction parameters (ethanol concentration, solvent to solid ratio, extraction time, temperature and ultrasound power) were investigated by single-factor experiments, and then a central composite rotatable design was employed to study interaction of three key extraction parameters. The optimum conditions were as follows: 57.38% ethanol, 70.15 mL/g solvent to solid ratio, 10.58 min extraction time, 40 °C extraction temperature and 500 W ultrasound power. Under the optimum conditions, the antioxidant activity obtained was 346.98 ± 12.19 µmol Trolox/g DW, in accordance with the predicted value of 344.67 µmol Trolox/g DW. Comparison of UAE with conventional maceration and Soxhlet extraction, the UAE method showed stronger extract efficiency in a shorter extraction time. These results showed that UAE was an effective technique to extract antioxidants from Thelephora ganbajun . Furthermore, the extracts obtained under the optimized conditions exhibited antiproliferative activities toward human lung (A549), breast (MCF-7), liver (HepG2) and colon (HT-29) cancer cells, especially for liver and lung cancer cells. In addition, rutin, 2-hydrocinnamic acid and epicatechin were identified in the extract, which might contribute to antioxidant and antiproliferative activities.

Extraction of Natural Antioxidants from the Thelephora ganbajun Mushroom by an Ultrasound-Assisted Extraction Technique and Evaluation of Antiproliferative Activity of the Extract against Human Cancer Cells

PubMed Central

Xu, Dong-Ping; Zheng, Jie; Zhou, Yue; Li, Ya; Li, Sha; Li, Hua-Bin

2016-01-01

The Thelephora ganbajun mushroom has been found to be a potential rich source of natural antioxidants. In this study, an ultrasound-assisted extraction (UAE) technique together with GRAS (generally recognized as safe) solvents (ethanol and water) was used to maximize the extraction of antioxidants from Thelephora ganbajun. Five extraction parameters (ethanol concentration, solvent to solid ratio, extraction time, temperature and ultrasound power) were investigated by single-factor experiments, and then a central composite rotatable design was employed to study interaction of three key extraction parameters. The optimum conditions were as follows: 57.38% ethanol, 70.15 mL/g solvent to solid ratio, 10.58 min extraction time, 40 °C extraction temperature and 500 W ultrasound power. Under the optimum conditions, the antioxidant activity obtained was 346.98 ± 12.19 µmol Trolox/g DW, in accordance with the predicted value of 344.67 µmol Trolox/g DW. Comparison of UAE with conventional maceration and Soxhlet extraction, the UAE method showed stronger extract efficiency in a shorter extraction time. These results showed that UAE was an effective technique to extract antioxidants from Thelephora ganbajun. Furthermore, the extracts obtained under the optimized conditions exhibited antiproliferative activities toward human lung (A549), breast (MCF-7), liver (HepG2) and colon (HT-29) cancer cells, especially for liver and lung cancer cells. In addition, rutin, 2-hydrocinnamic acid and epicatechin were identified in the extract, which might contribute to antioxidant and antiproliferative activities. PMID:27706082

Application of Response Surface Methodology for Optimization of Extracellular Glucoamylase Production by Candida guilliermondii.

PubMed

Mohamed, Lagzouli; Kettani, Youssfi El; Ali, Aitounejjar; Mohamed, Elyachioui; Mohamed, Jadal

2017-01-01

Glucoamylase is among the most important enzymes in biotechnology. The present study aims to determine better conditions for growth and glucoamylase production by Candida guilliermondii and to reduce the overall cost of the medium using Box-Behnken design with one central point and response surface methodology. Box-Behnken factorial design based on three levels was carried out to obtain optimal medium combination of five independent variables such as initial pH, soluble starch, CH4N2O, yeast extract and MgSO4. Forty one randomized mediums were incubated in flask on a rotary shaker at 105 rpm for 72 h at 30°C. The production of biomass was found to be pH and starch dependent, maximum production when the starch concentration was 8 g L-1 and the initial pH was 6, while maximum glucoamylase production was found at 6.5 of initial pH, 4 g L-1 yeast extract and 6 g L-1 starch, whereas yeast extract and urea were highly significant, but interacted negatively. Box-Behnken factorial design used for the analysis of treatment combinations gave a second-order polynomial regression model with R2 = 0.976 for Biomass and R2 = 0.981 for glucoamylase. The final biomass and glucoamylase activity obtained was very close to the calculated parameters according to the p-values (p<0.001), the predicted optimal parameters were confirmed and provides a basis for further studies in baking additives and in the valuation of starch waste products.

Microwave alkaline roasting-water dissolving process for germanium extraction from zinc oxide dust and its analysis by response surface methodology (RSM)

NASA Astrophysics Data System (ADS)

Wang, Wankun; Wang, Fuchun; Lu, Fanghai

2017-12-01

Microwave alkaline roasting-water dissolving process was proposed to improve the germanium (Ge) extraction from zinc oxide (ZnO) dust. The effects of important parameters were investigated and the process conditions were optimized using response surface methodology (RSM). The Ge extraction is consistent with the linear polynomial model type. Alkali-material ratio, microwave heating temperature and leaching temperature are the significant factors for this process. The optimized conditions are obtained as follows, alkali-material ratio of 0.9 kg/kg, aging time of 1.12 day, microwave heating at 658 K for 10 min, liquid-solid ratio of 4.31 L/kg, leaching temperature at 330 K, leaching time of 47 min with the Ge extraction about 99.38%. It is in consistence with the predictive value of 99.31%. Compared to the existed alkaline roasting process heated by electric furnace in literature, the alkaline roasting temperature and holding time. It shows a good prospect on leaching Ge from ZnO dust with microwave alkaline roasting-water dissolving process.

A recyclable protein resource derived from cauliflower by-products: Potential biological activities of protein hydrolysates.

PubMed

Xu, Yang; Li, Yuting; Bao, Tao; Zheng, Xiaodong; Chen, Wei; Wang, Jianxu

2017-04-15

Cauliflower by-products (CBP) are rich in leaf protein. Every year tons of CBP will lead to environmental pollution. Therefore, this study was conducted to extract leaf protein from CBP and investigate its biological activities. Our results showed that the optimal extraction parameters were: a liquid to solid ratio of 4mL/g, a pH of 11, an ultrasonic extraction lasting 15min, and at an applied power of 175W. Under these optimized conditions, 12.066g of soluble leaf protein (SLP) was obtained from 1000g of CBP and its extraction yield was 53.07%. The obtained SLP was further hydrolysed by Alcalase and the SLP hydrolysate (SLPH) showed a potent angiotensin I-converting enzyme (ACE) inhibitory activity with an IC 50 value of 138.545μg/mL in vitro. In addition, SLPH promoted the glucose consumption and enhanced the glycogen content in HepG2 cells. Overall, our results suggested that CBP may be recycled for designing future functional foods. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis, characterization, and application of a Zn (II)-imprinted polymer grafted on graphene oxide/magnetic chitosan nanocomposite for selective extraction of zinc ions from different food samples.

PubMed

Kazemi, Elahe; Dadfarnia, Shayessteh; Haji Shabani, Ali Mohammad; Ranjbar, Mansoureh

2017-12-15

A novel Zn(II) imprinted polymer was synthesized via a co-precipitation method using graphene oxide/magnetic chitosan nanocomposite as supporting material. The synthesized imprinted polymer was characterized by Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy (SEM) and applied as a sorbent for selective magnetic solid phase extraction of zinc followed by its determination by flame atomic absorption spectrometry. The kinetic and isothermal adsorption experiments were carried out and all parameters affecting the extraction process was optimized. Under the optimal experimental conditions, the developed procedure exhibits a linear dynamic range of 0.5-5.0µgL -1 with a detection limit of 0.09µgL -1 and quantification limit of 0.3µgL -1 . The maximum sorption capacity of the sorbent was found to be 71.4mgg -1 . The developed procedure was successfully applied to the selective extraction and determination of zinc in various samples including well water, drinking water, black tea, rice, and milk. Copyright © 2017 Elsevier Ltd. All rights reserved.

Application of mixed cloud point extraction for the analysis of six flavonoids in Apocynum venetum leaf samples by high performance liquid chromatography.

PubMed

Zhou, Jun; Sun, Jiang Bing; Xu, Xin Yu; Cheng, Zhao Hui; Zeng, Ping; Wang, Feng Qiao; Zhang, Qiong

2015-03-25

A simple, inexpensive and efficient method based on the mixed cloud point extraction (MCPE) combined with high performance liquid chromatography was developed for the simultaneous separation and determination of six flavonoids (rutin, hyperoside, quercetin-3-O-sophoroside, isoquercitrin, astragalin and quercetin) in Apocynum venetum leaf samples. The non-ionic surfactant Genapol X-080 and cetyl-trimethyl ammonium bromide (CTAB) was chosen as the mixed extracting solvent. Parameters that affect the MCPE processes, such as the content of Genapol X-080 and CTAB, pH, salt content, extraction temperature and time were investigated and optimized. Under the optimized conditions, the calibration curve for six flavonoids were all linear with the correlation coefficients greater than 0.9994. The intra-day and inter-day precision (RSD) were below 8.1% and the limits of detection (LOD) for the six flavonoids were 1.2-5.0 ng mL(-1) (S/N=3). The proposed method was successfully used to separate and determine the six flavonoids in A. venetum leaf samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Development of Hollow-Fiber Liquid-Phase Microextraction Method for Determination of Urinary trans,trans-Muconic Acid as a Biomarker of Benzene Exposure

PubMed Central

Ghamari, Farhad; Bahrami, Abdulrahman; Yamini, Yadollah; Shahna, Farshid Ghorbani; Moghimbeigi, Abbas

2016-01-01

For the first time, hollow-fiber liquid-phase microextraction combined with high-performance liquid chromatography–ultraviolet was used to extract trans,trans-muconic acid, in urine samples of workers who had been exposed to benzene. The parameters affecting the metabolite extraction were optimized as follows: the volume of sample solution was 11 mL with pH 2, liquid membrane containing dihexyl ether as the supporter, 15% (w/v) of trioctylphosphine oxide as the carrier, the time of extraction was 120 minutes, and stirring rate was 500 rpm. Organic phase impregnated in the pores of a hollow fiber was extracted into 24 µL solution of 0.05 mol L−1 Na2CO3 located inside the lumen of the fiber. Under optimized conditions, a high enrichment factor of 153–182 folds, relative recovery of 83%–92%, and detection limit of 0.001 µg mL−1 were obtained. The method was successfully applied to the analysis of ttMA in real urine samples. PMID:27660405

Solid phase microextraction of diclofenac using molecularly imprinted polymer sorbent in hollow fiber combined with fiber optic-linear array spectrophotometry.

PubMed

Pebdani, Arezou Amiri; Shabani, Ali Mohammad Haji; Dadfarnia, Shayessteh; Khodadoust, Saeid

2015-08-05

A simple solid phase microextraction method based on molecularly imprinted polymer sorbent in the hollow fiber (MIP-HF-SPME) combined with fiber optic-linear array spectrophotometer has been applied for the extraction and determination of diclofenac in environmental and biological samples. The effects of different parameters such as pH, times of extraction, type and volume of the organic solvent, stirring rate and donor phase volume on the extraction efficiency of the diclofenac were investigated and optimized. Under the optimal conditions, the calibration graph was linear (r(2)=0.998) in the range of 3.0-85.0 μg L(-1) with a detection limit of 0.7 μg L(-1) for preconcentration of 25.0 mL of the sample and the relative standard deviation (n=6) less than 5%. This method was applied successfully for the extraction and determination of diclofenac in different matrices (water, urine and plasma) and accuracy was examined through the recovery experiments. Copyright © 2015 Elsevier B.V. All rights reserved.

Magnetic porous carbon derived from a bimetallic metal-organic framework for magnetic solid-phase extraction of organochlorine pesticides from drinking and environmental water samples.

PubMed

Liu, Yaxi; Gao, Zongjun; Wu, Ri; Wang, Zhenhua; Chen, Xiangfeng; Chan, T-W Dominic

2017-01-06

In this work, magnetic porous carbon material derived from a bimetallic metal-organic framework was explored as an adsorbent for magnetic solid-phase extraction of organochlorine pesticides (OCPs). The synthesized porous carbon possessed a high specific surface area and magnetization saturation. The OCPs in the samples were quantified using gas chromatography coupled with a triple quadrupole mass spectrometer. The experimental parameters, including the desorption solvent and conditions, amount of adsorbent, extraction time, extraction temperature, and ionic strength of the solution, were optimized. Under optimal conditions, the developed method displayed good linearity (r>0.99) within the concentration range of 2-500ngL -1 . Low limits of detection (0.39-0.70ngL -1 , signal-to-noise ratio=3:1) and limits of quantification (1.45-2.0ngL -1 , signal-to-noise ratio=10:1) as well as good precision (relative standard deviation<10%) were also obtained. The developed method was applied in the analysis of OCPs in drinking and environmental water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Rapid analysis of ultraviolet filters using dispersive liquid-liquid microextraction coupled to headspace gas chromatography and mass spectrometry.

PubMed

Pierson, Stephen A; Trujillo-Rodríguez, María J; Anderson, Jared L

2018-05-29

An ionic-liquid-based in situ dispersive liquid-liquid microextraction method coupled to headspace gas chromatography and mass spectrometry was developed for the rapid analysis of ultraviolet filters. The chemical structures of five ionic liquids were specifically designed to incorporate various functional groups for the favorable extraction of the target analytes. Extraction parameters including ionic liquid mass, molar ratio of ionic liquid to metathesis reagent, vortex time, ionic strength, pH, and total sample volume were studied and optimized. The effect of the headspace temperature and volume during the headspace sampling step was also evaluated to increase the sensitivity of the method. The optimized procedure is fast as it only required ∼7-10 min per extraction and allowed for multiple extractions to be performed simultaneously. In addition, the method exhibited high precision, good linearity, and low limits of detection for six ultraviolet filters in aqueous samples. The developed method was applied to both pool and lake water samples attaining acceptable relative recovery values. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An insight into the determination of trace levels of benzodiazepines in biometric systems: Use of crab shell powder as an environmentally friendly biosorbent.

PubMed

Samadi, Fatemeh; Sarafraz-Yazdi, Ali; Es'haghi, Zarrin

2018-05-30

A vortex assisted dispersive solid phase extraction approach (VADSPE) based on crab shell powder as biodegradable and biocompatible μ-sorbent was developed for simultaneous analysis of three benzodiazepines (BZPs): Oxazepam, Flurazepamand Diazepam, in biological matrixes included blood, nail, hair and urine samples. The effective parameters in VADSPE process, including the volume of uptake solvent, the dosage of sorbent, extraction time and back extraction time, were optimized using response surface methodology(RSM) based on central composite design(CCD). The suggested technique allows successful trapping of BZPs in a single-step extraction. Under the optimized extraction conditions, the proposed approach was exhibited low limits of detection (0.003-1.2 μg·mL -1 ), an acceptable linearity (0.04-20 μg·mL -1 ). Method performance was assessed by recovery experiments at spiking levels of 10 μg·mL -1 (n = 5) for BZPs in blood, nail, hair and urine samples. Relative recoveries were determined by HPLC, which were between 36%and 95.6%. Copyright © 2018. Published by Elsevier B.V.

Development of Extraction Methods for the Analysis of Perfluorinated Compounds in Leather with High Performance Liquid Chromatography Tandem Mass Spectrometry

NASA Astrophysics Data System (ADS)

Zhang, Yan; Wang, Youchao; Tang, Chuanjiang; Nie, Jingmei; Xu, Chengtao

2018-01-01

Perfluorinated compounds (PFCs), used to provide water, oil, grease, heat and stain repellency to a range of textile and other products, have been found to be persistent in the environment and are associated with adverse effects on humans and wildlife. This study presents the development and validation of an analytical method to determine the simultaneous presence of eleven PFCs in leather using solid-phase extraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The perfluorinated compounds were primarily extracted from the samples by a liquid extraction procedure by ultrasonic, in which the parameters were optimized. Then the solid-phase extraction (SPE) is the most important advantages of the developed methodology. The sample volume and elution conditions were optimized by means of an experimental design. The proposed method was applied to determine the PFCs in leather, where the detection limits of the eleven compounds were 0.09-0.96 ng/L, and the recoveries of all compounds spiked at 5 ng/L concentration level were in the range of 65-96%, with a better RSD lower than 19% (n = 7).

Dispersive solid-phase extraction for the determination of trace organochlorine pesticides in apple juices using reduced graphene oxide coated with ZnO nanocomposites as sorbent.

PubMed

Sun, Ting; Sun, Hefeng; Zhao, Feng

2017-09-01

In this work, reduced graphene oxide coated with ZnO nanocomposites was used as an efficient sorbent of dispersive solid-phase extraction and successfully applied for the extraction of organochlorine pesticides from apple juice followed by gas chromatography with mass spectrometry. Several experimental parameters affecting the extraction efficiencies, including the amount of adsorbent, extraction time, and the pH of the sample solution, as well as the type and volume of eluent solvent, were investigated and optimized. Under the optimal experimental conditions, good linearity existed in the range of 1.0-200.0 ng/mL for all the analytes with the correlation coefficients (R 2 ) ranging from 0.9964 to 0.9994. The limits of detection of the method for the compounds were 0.011-0.053 ng/mL. Good reproducibilities were acquired with relative standard deviations below 8.7% for both intraday and interday precision. The recoveries of the method were in the range of 78.1-105.8% with relative standard deviations of 3.3-6.9%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effervescence-assisted dispersive solid-phase extraction using ionic-liquid-modified magnetic β-cyclodextrin/attapulgite coupled with high-performance liquid chromatography for fungicide detection in honey and juice.

PubMed

Wu, Xiaoling; Yang, Miyi; Zeng, Haozhe; Xi, Xuefei; Zhang, Sanbing; Lu, Runhua; Gao, Haixiang; Zhou, Wenfeng

2016-11-01

In this study, a simple effervescence-assisted dispersive solid-phase extraction method was developed to detect fungicides in honey and juice. Most significantly, an innovative ionic-liquid-modified magnetic β-cyclodextrin/attapulgite sorbent was used because its large specific surface area enhanced the extraction capacity and also led to facile separation. A one-factor-at-a-time approach and orthogonal design were employed to optimize the experimental parameters. Under the optimized conditions, the entire extraction procedure was completed within 3 min. In addition, the calibration curves exhibited good linearity, and high enrichment factors were achieved for pure water and honey samples. For the honey samples, the extraction efficiencies for the target fungicides ranged from 77.0 to 94.3% with relative standard deviations of 2.3-5.44%. The detection and quantitation limits were in the ranges of 0.07-0.38 and 0.23-1.27 μg/L, respectively. Finally, the developed technique was successfully applied to real samples, and satisfactory results were achieved. This analytical technique is cost-effective, environmentally friendly, and time-saving. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Graphene oxide: an adsorbent for the extraction and quantification of aflatoxins in peanuts by high-performance liquid chromatography.

PubMed

Yu, Li; Li, Peiwu; Zhang, Qi; Zhang, Wen; Ding, Xiaoxia; Wang, Xiupin

2013-11-29

In this paper, graphene oxide (GO) was synthesized and specifically selected by centrifugation to extract four aflatoxins (B1, B2, G1, and G2) as an effective adsorbent. Then, the amount of aflatoxins was quantitatively measured by high-performance liquid chromatography (HPLC). The GO was characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), and ultraviolet (UV) spectrophotometer. Several parameters that could affect the extraction efficiency, including the GO amount, methanol concentration in the extraction solvent, spiked amount, extraction time, and elution cycle, were also investigated and optimized in this work. Under optimal conditions, good linear relationships were achieved with the correlation coefficient (r) ranging from 0.99217 to 0.99995. The detection limit of this method for the four aflatoxins ranged from 0.08 to 0.65ng/g. Finally, the proposed method has been successfully applied to determine aflatoxins in peanut samples. The results show that the recoveries of the four aflatoxins range from 85.1% to 100.8% with the relative standard deviations between 2.1% and 7.9%. Copyright © 2013 Elsevier B.V. All rights reserved.

Multivariate Optimization for Extraction of Pyrethroids in Milk and Validation for GC-ECD and CG-MS/MS Analysis

PubMed Central

Zanchetti Meneghini, Leonardo; Rübensam, Gabriel; Claudino Bica, Vinicius; Ceccon, Amanda; Barreto, Fabiano; Flores Ferrão, Marco; Bergold, Ana Maria

2014-01-01

A simple and inexpensive method based on solvent extraction followed by low temperature clean-up was applied for determination of seven pyrethroids residues in bovine raw milk using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) and gas chromatography with electron-capture detector (GC-ECD). Sample extraction procedure was established through the evaluation of seven different extraction protocols, evaluated in terms of analyte recovery and cleanup efficiency. Sample preparation optimization was based on Doehlert design using fifteen runs with three different variables. Response surface methodologies and polynomial analysis were used to define the best extraction conditions. Method validation was carried out based on SANCO guide parameters and assessed by multivariate analysis. Method performance was considered satisfactory since mean recoveries were between 87% and 101% for three distinct concentrations. Accuracy and precision were lower than ±20%, and led to no significant differences (p < 0.05) between results obtained by GC-ECD and GC-MS/MS techniques. The method has been applied to routine analysis for determination of pyrethroid residues in bovine raw milk in the Brazilian National Residue Control Plan since 2013, in which a total of 50 samples were analyzed. PMID:25380457

Optimization and Scale-up of Inulin Extraction from Taraxacum kok-saghyz roots.

PubMed

Hahn, Thomas; Klemm, Andrea; Ziesse, Patrick; Harms, Karsten; Wach, Wolfgang; Rupp, Steffen; Hirth, Thomas; Zibek, Susanne

2016-05-01

The optimization and scale-up of inulin extraction from Taraxacum kok-saghyz Rodin was successfully performed. Evaluating solubility investigations, the extraction temperature was fixed at 85 degrees C. The inulin stability regarding degradation or hydrolysis could be confirmed by extraction in the presence of model inulin. Confirming stability at the given conditions the isolation procedure was transferred from a 1 L- to a 1 m3-reactor. The Reynolds number was selected as the relevant dimensionless number that has to remain constant in both scales. The stirrer speed in the large scale was adjusted to 3.25 rpm regarding a 300 rpm stirrer speed in the 1 L-scale and relevant physical and process engineering parameters. Assumptions were confirmed by approximately homologous extraction kinetics in both scales. Since T. kok-saghyz is in the focus of research due to its rubber content side-product isolation from residual biomass it is of great economic interest. Inulin is one of these additional side-products that can be isolated in high quantity (- 35% of dry mass) and with a high average degree of polymerization (15.5) in large scale with a purity of 77%.

Optimal design of minimum mean-square error noise reduction algorithms using the simulated annealing technique.

PubMed

Bai, Mingsian R; Hsieh, Ping-Ju; Hur, Kur-Nan

2009-02-01

The performance of the minimum mean-square error noise reduction (MMSE-NR) algorithm in conjunction with time-recursive averaging (TRA) for noise estimation is found to be very sensitive to the choice of two recursion parameters. To address this problem in a more systematic manner, this paper proposes an optimization method to efficiently search the optimal parameters of the MMSE-TRA-NR algorithms. The objective function is based on a regression model, whereas the optimization process is carried out with the simulated annealing algorithm that is well suited for problems with many local optima. Another NR algorithm proposed in the paper employs linear prediction coding as a preprocessor for extracting the correlated portion of human speech. Objective and subjective tests were undertaken to compare the optimized MMSE-TRA-NR algorithm with several conventional NR algorithms. The results of subjective tests were processed by using analysis of variance to justify the statistic significance. A post hoc test, Tukey's Honestly Significant Difference, was conducted to further assess the pairwise difference between the NR algorithms.

Electromembrane extraction of zwitterionic compounds as acid or base: comparison of extraction behavior at acidic and basic pHs.

PubMed

Nojavan, Saeed; Pourahadi, Ahmad; Hosseiny Davarani, Saied Saeed; Morteza-Najarian, Amin; Beigzadeh Abbassi, Mojtaba

2012-10-01

This study has performed on electromembrane extraction (EME) of some zwitterionic compounds based on their acidic and basic properties. High performance liquid chromatography (HPLC) equipped with UV detection was used for determination of model compounds. Cetirizine (CTZ) and mesalazine (MS) were chosen as model compounds, and each of them was extracted from acidic (as a cation) and basic (as an anion) sample solutions, separately. 1-Octanol and 2-nitrophenyl octylether (NPOE) were used as the common supported liquid membrane (SLM) solvents. EME parameters, such as extraction time, extraction voltage and pH of donor and acceptor solutions were studied in details for cationic and anionic forms of each model compound and obtained results for two ionic forms (cationic and anionic) of each compound were compared together. Results showed that zwitterionic compounds could be extracted in both cationic and anionic forms. Moreover, it was found that the extraction of anionic form of each model compound could be done in low voltages when 1-octanol was used as the SLM solvent. Results showed that charge type was not highly effective on the extraction efficiency of model compounds whereas the position of charge within the molecule was the key parameter. In optimized conditions, enrichment factors (EF) of 27-60 that corresponded to recoveries ranging from 39 to 86% were achieved. Copyright © 2012 Elsevier B.V. All rights reserved.

Feature selection and classification of multiparametric medical images using bagging and SVM

NASA Astrophysics Data System (ADS)

Fan, Yong; Resnick, Susan M.; Davatzikos, Christos

2008-03-01

This paper presents a framework for brain classification based on multi-parametric medical images. This method takes advantage of multi-parametric imaging to provide a set of discriminative features for classifier construction by using a regional feature extraction method which takes into account joint correlations among different image parameters; in the experiments herein, MRI and PET images of the brain are used. Support vector machine classifiers are then trained based on the most discriminative features selected from the feature set. To facilitate robust classification and optimal selection of parameters involved in classification, in view of the well-known "curse of dimensionality", base classifiers are constructed in a bagging (bootstrap aggregating) framework for building an ensemble classifier and the classification parameters of these base classifiers are optimized by means of maximizing the area under the ROC (receiver operating characteristic) curve estimated from their prediction performance on left-out samples of bootstrap sampling. This classification system is tested on a sex classification problem, where it yields over 90% classification rates for unseen subjects. The proposed classification method is also compared with other commonly used classification algorithms, with favorable results. These results illustrate that the methods built upon information jointly extracted from multi-parametric images have the potential to perform individual classification with high sensitivity and specificity.

Optimisation of Ethanol-Reflux Extraction of Saponins from Steamed Panax notoginseng by Response Surface Methodology and Evaluation of Hematopoiesis Effect.

PubMed

Hu, Yupiao; Cui, Xiuming; Zhang, Zejun; Chen, Lijuan; Zhang, Yiming; Wang, Chengxiao; Yang, Xiaoyan; Qu, Yuan; Xiong, Yin

2018-05-17

The present study aims to optimize the ethanol-reflux extraction conditions for extracting saponins from steamed Panax notoginseng (SPN). Four variables including the extraction time (0.5⁻2.5 h), ethanol concentration (50⁻90%), water to solid ratio (W/S, 8⁻16), and times of extraction (1⁻5) were investigated by using the Box-Behnken design response surface methodology (BBD-RSM). For each response, a second-order polynomial model with high R² values (>0.9690) was developed using multiple linear regression analysis and the optimum conditions to maximize the yield (31.96%), content (70.49 mg/g), and antioxidant activity (EC 50 value of 0.0421 mg/mL) for saponins extracted from SPN were obtained with a extraction time of 1.51 h, ethanol concentration of 60%, extraction done 3 times, and a W/S of 10. The experimental values were in good consistency with the predicted ones. In addition, the extracted SPN saponins could significantly increase the levels of blood routine parameters compared with the model group (p < 0.01) and there was no significant difference in the hematopoiesis effect between the SPN group and the SPN saponins group, of which the dose was 15 times lower than the former one. It is suggested that the SPN saponins extracted by the optimized method had similar functions of "blood tonifying" at a much lower dose.

Optimization of Cat's Whiskers Tea (Orthosiphon stamineus) Using Supercritical Carbon Dioxide and Selective Chemotherapeutic Potential against Prostate Cancer Cells

PubMed Central

Al-Suede, Fouad Saleih R.; Khadeer Ahamed, Mohamed B.; Abdul Majid, Aman S.; Baharetha, Hussin M.; Hassan, Loiy E. A.; Kadir, Mohd Omar A.; Nassar, Zeyad D.; Abdul Majid, Amin M. S.

2014-01-01

Cat's whiskers (Orthosiphon stamineus) leaves extracts were prepared using supercritical CO2 (SC-CO2) with full factorial design to determine the optimum extraction parameters. Nine extracts were obtained by varying pressure, temperature, and time. The extracts were analysed using FTIR, UV-Vis, and GC-MS. Cytotoxicity of the extracts was evaluated on human (colorectal, breast, and prostate) cancer and normal fibroblast cells. Moderate pressure (31.1 MPa) and temperature (60°C) were recorded as optimum extraction conditions with high yield (1.74%) of the extract (B2) at 60 min extraction time. The optimized extract (B2) displayed selective cytotoxicity against prostate cancer (PC3) cells (IC50 28 µg/mL) and significant antioxidant activity (IC50 42.8 µg/mL). Elevated levels of caspases 3/7 and 9 in B2-treated PC3 cells suggest the induction of apoptosis through nuclear and mitochondrial pathways. Hoechst and rhodamine assays confirmed the nuclear condensation and disruption of mitochondrial membrane potential in the cells. B2 also demonstrated inhibitory effects on motility and colonies of PC3 cells at its subcytotoxic concentrations. It is noteworthy that B2 displayed negligible toxicity against the normal cells. Chemometric analysis revealed high content of essential oils, hydrocarbon, fatty acids, esters, and aromatic sesquiterpenes in B2. This study highlights the therapeutic potentials of SC-CO2 extract of cat's whiskers in targeting prostate carcinoma. PMID:25276215

Parameters optimization using experimental design for headspace solid phase micro-extraction analysis of short-chain chlorinated paraffins in waters under the European water framework directive.

PubMed

Gandolfi, F; Malleret, L; Sergent, M; Doumenq, P

2015-08-07

The water framework directives (WFD 2000/60/EC and 2013/39/EU) force European countries to monitor the quality of their aquatic environment. Among the priority hazardous substances targeted by the WFD, short chain chlorinated paraffins C10-C13 (SCCPs), still represent an analytical challenge, because few laboratories are nowadays able to analyze them. Moreover, an annual average quality standards as low as 0.4μgL(-1) was set for SCCPs in surface water. Therefore, to test for compliance, the implementation of sensitive and reliable analysis method of SCCPs in water are required. The aim of this work was to address this issue by evaluating automated solid phase micro-extraction (SPME) combined on line with gas chromatography-electron capture negative ionization mass spectrometry (GC/ECNI-MS). Fiber polymer, extraction mode, ionic strength, extraction temperature and time were the most significant thermodynamic and kinetic parameters studied. To determine the suitable factors working ranges, the study of the extraction conditions was first carried out by using a classical one factor-at-a-time approach. Then a mixed level factorial 3×2(3) design was performed, in order to give rise to the most influent parameters and to estimate potential interactions effects between them. The most influent factors, i.e. extraction temperature and duration, were optimized by using a second experimental design, in order to maximize the chromatographic response. At the close of the study, a method involving headspace SPME (HS-SPME) coupled to GC/ECNI-MS is proposed. The optimum extraction conditions were sample temperature 90°C, extraction time 80min, with the PDMS 100μm fiber and desorption at 250°C during 2min. Linear response from 0.2ngmL(-1) to 10ngmL(-1) with r(2)=0.99 and limits of detection and quantification, respectively of 4pgmL(-1) and 120pgmL(-1) in MilliQ water, were achieved. The method proved to be applicable in different types of waters and show key advantages, such as simplicity, automation and sensitivity, required for the monitoring programs linked to the WFD. Copyright © 2015 Elsevier B.V. All rights reserved.

Toxicology of the aqueous extract from the flowers of Butea monosperma Lam. and it's metabolomics in yeast cells.

PubMed

Khan, Washim; Gupta, Shreesh; Ahmad, Sayeed

2017-10-01

Due to lack of scientific evidence for the safety of Butea monosperma (Fabaceae), our study aimed to carry out its toxicological profile and to identify its metabolic pattern in yeast cell. The effect of aqueous extract of B. monosperma flower on glucose uptake in yeast cell was evaluated through optimizing pH, temperature, incubation time, substrate concentration and kinetic parameters. Further, the metabolic pattern of extract as such and in yeast cell were analyzed by gas chromatography-mass spectrometry. Mice were administered aqueous extract up to 6000 and 4000 mg/kg for acute oral and intraperitoneal toxicity, respectively, while up to 4500 mg/kg for sub-acute oral toxicity (30 days). Elongation in the lag and log phase was observed in yeast cells supplemented with extract as compared to control. A maximum of 184.9% glucose uptake was observed whereas kinetic parameters (K m and V max ) were 1.38 and 41.91 mol/s, respectively. Out of 75 metabolites found in the extract, 14 and 18 metabolites were utilized by yeast cell after 15 and 30 min of incubation, respectively. The LD 50 of extract administered through intraperitoneal route was estimated to be 3500 mg/kg. The extract did not elicit any significant difference (P ≥ 0.05) in weight gain, food consumption, water intake, hematological, biochemical parameters and histological changes as compared to the normal control. Results ascertained the safety of B. monosperma flower extract which can be explored as potential candidates for the development of anti-diabetic phytopharmaceuticals. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Novel Selective Deep Eutectic Solvent Extraction Method for Versatile Determination of Copper in Sediment Samples by ICP-OES.

PubMed

Bağda, Esra; Altundağ, Huseyin; Tüzen, Mustafa; Soylak, Mustafa

2017-08-01

In the present study, a simple, mono step deep eutectic solvent (DES) extraction was developed for selective extraction of copper from sediment samples. The optimization of all experimental parameters, e.g. DES type, sample/DES ratio, contact time and temperature were performed with using BCR-280 R (lake sediment certified reference material). The limit of detection (LOD) and the limit of quantification (LOQ) were found as 1.2 and 3.97 µg L -1 , respectively. The RSD of the procedure was 7.5%. The proposed extraction method was applied to river and lake sediments sampled from Serpincik, Çeltek, Kızılırmak (Fadl and Tecer region of the river), Sivas-Turkey.

Microwave assisted solid phase extraction for separation preconcentration sulfamethoxazole in wastewater using tyre based activated carbon as solid phase material prior to spectrophotometric determination

NASA Astrophysics Data System (ADS)

Mogolodi Dimpe, K.; Mpupa, Anele; Nomngongo, Philiswa N.

2018-01-01

This work was chiefly encouraged by the continuous consumption of antibiotics which eventually pose harmful effects on animals and human beings when present in water systems. In this study, the activated carbon (AC) was used as a solid phase material for the removal of sulfamethoxazole (SMX) in wastewater samples. The microwave assisted solid phase extraction (MASPE) as a sample extraction method was employed to better extract SMX in water samples and finally the analysis of SMX was done by the UV-Vis spectrophotometer. The microwave assisted solid phase extraction method was optimized using a two-level fractional factorial design by evaluating parameters such as pH, mass of adsorbent (MA), extraction time (ET), eluent ratio (ER) and microwave power (MP). Under optimized conditions, the limit of detection (LOD) and limit of quantification (LOQ) were 0.5 μg L- 1 and 1.7 μg L- 1, respectively, and intraday and interday precision expressed in terms of relative standard deviation were > 6%.The maximum adsorption capacity was 138 mg g- 1 for SMX and the adsorbent could be reused eight times. Lastly, the MASPE method was applied for the removal of SMX in wastewater samples collected from a domestic wastewater treatment plant (WWTP) and river water.

Sensitive determination of polycyclic aromatic hydrocarbons in water samples by HPLC coupled with SPE based on graphene functionalized with triethoxysilane.

PubMed

Huang, Ke-Jing; Li, Jing; Liu, Yan-Ming; Wang, Lan

2013-02-01

The graphene functionalized with (3-aminopropyl) triethoxysilane was synthesized by a simple hydrothermal reaction and applied as SPE sorbents to extract trace polycyclic aromatic hydrocarbons (PAHs) from environmental water samples. These sorbents possess high adsorption capacity and extraction efficiency due to strong adsorption ability of carbon materials and large specific surface area of nanoparticles, and only 10 mg of sorbents are required to extract PAHs from 100 mL water samples. Several condition parameters, such as eluent and its volume, adsorbent amount, sample volume, sample pH, and sample flow rate, were optimized to achieve good sensitivity and precision. Under the optimized extraction conditions, the method showed good linearity in the range of 1-100 μg/L, repeatability of the extraction (the RSDs were between 1.8 and 2.9%, n = 6), and satisfactory detection limits of 0.029-0.1 μg/L. The recoveries of PAHs spiked in environmental water samples ranged from 84.6 to 109.5%. All these results demonstrated that this new SPE technique was a viable alternative to conventional enrichment techniques for the extraction and analysis of PAHs in complex samples. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Toward a Model-Based Predictive Controller Design in Brain–Computer Interfaces

PubMed Central

Kamrunnahar, M.; Dias, N. S.; Schiff, S. J.

2013-01-01

A first step in designing a robust and optimal model-based predictive controller (MPC) for brain–computer interface (BCI) applications is presented in this article. An MPC has the potential to achieve improved BCI performance compared to the performance achieved by current ad hoc, nonmodel-based filter applications. The parameters in designing the controller were extracted as model-based features from motor imagery task-related human scalp electroencephalography. Although the parameters can be generated from any model-linear or non-linear, we here adopted a simple autoregressive model that has well-established applications in BCI task discriminations. It was shown that the parameters generated for the controller design can as well be used for motor imagery task discriminations with performance (with 8–23% task discrimination errors) comparable to the discrimination performance of the commonly used features such as frequency specific band powers and the AR model parameters directly used. An optimal MPC has significant implications for high performance BCI applications. PMID:21267657

Toward a model-based predictive controller design in brain-computer interfaces.

PubMed

Kamrunnahar, M; Dias, N S; Schiff, S J

2011-05-01

A first step in designing a robust and optimal model-based predictive controller (MPC) for brain-computer interface (BCI) applications is presented in this article. An MPC has the potential to achieve improved BCI performance compared to the performance achieved by current ad hoc, nonmodel-based filter applications. The parameters in designing the controller were extracted as model-based features from motor imagery task-related human scalp electroencephalography. Although the parameters can be generated from any model-linear or non-linear, we here adopted a simple autoregressive model that has well-established applications in BCI task discriminations. It was shown that the parameters generated for the controller design can as well be used for motor imagery task discriminations with performance (with 8-23% task discrimination errors) comparable to the discrimination performance of the commonly used features such as frequency specific band powers and the AR model parameters directly used. An optimal MPC has significant implications for high performance BCI applications.

Optimization of the Electrochemical Extraction and Recovery of Metals from Electronic Waste Using Response Surface Methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diaz, Luis A.; Clark, Gemma G.; Lister, Tedd E.

The rapid growth of the electronic waste can be viewed both as an environmental threat and as an attractive source of minerals that can reduce the mining of natural resources, and stabilize the market of critical materials, such as rare earths. Here in this article surface response methodology was used to optimize a previously developed electrochemical recovery process for base metals from electronic waste using a mild oxidant (Fe 3+). Through this process an effective extraction of base metals can be achieved enriching the concentration of precious metals and significantly reducing environmental impacts and operational costs associated with the wastemore » generation and chemical consumption. The optimization was performed using a bench-scale system specifically designed for this process. Operational parameters such as flow rate, applied current density and iron concentration were optimized to reduce the specific energy consumption of the electrochemical recovery process to 1.94 kWh per kg of metal recovered at a processing rate of 3.3 g of electronic waste per hour.« less

Optimization of the Electrochemical Extraction and Recovery of Metals from Electronic Waste Using Response Surface Methodology

DOE PAGES

Diaz, Luis A.; Clark, Gemma G.; Lister, Tedd E.

2017-06-08

The rapid growth of the electronic waste can be viewed both as an environmental threat and as an attractive source of minerals that can reduce the mining of natural resources, and stabilize the market of critical materials, such as rare earths. Here in this article surface response methodology was used to optimize a previously developed electrochemical recovery process for base metals from electronic waste using a mild oxidant (Fe 3+). Through this process an effective extraction of base metals can be achieved enriching the concentration of precious metals and significantly reducing environmental impacts and operational costs associated with the wastemore » generation and chemical consumption. The optimization was performed using a bench-scale system specifically designed for this process. Operational parameters such as flow rate, applied current density and iron concentration were optimized to reduce the specific energy consumption of the electrochemical recovery process to 1.94 kWh per kg of metal recovered at a processing rate of 3.3 g of electronic waste per hour.« less

Optimal observables for multiparameter seismic tomography

NASA Astrophysics Data System (ADS)

Bernauer, Moritz; Fichtner, Andreas; Igel, Heiner

2014-08-01

We propose a method for the design of seismic observables with maximum sensitivity to a target model parameter class, and minimum sensitivity to all remaining parameter classes. The resulting optimal observables thereby minimize interparameter trade-offs in multiparameter inverse problems. Our method is based on the linear combination of fundamental observables that can be any scalar measurement extracted from seismic waveforms. Optimal weights of the fundamental observables are determined with an efficient global search algorithm. While most optimal design methods assume variable source and/or receiver positions, our method has the flexibility to operate with a fixed source-receiver geometry, making it particularly attractive in studies where the mobility of sources and receivers is limited. In a series of examples we illustrate the construction of optimal observables, and assess the potentials and limitations of the method. The combination of Rayleigh-wave traveltimes in four frequency bands yields an observable with strongly enhanced sensitivity to 3-D density structure. Simultaneously, sensitivity to S velocity is reduced, and sensitivity to P velocity is eliminated. The original three-parameter problem thereby collapses into a simpler two-parameter problem with one dominant parameter. By defining parameter classes to equal earth model properties within specific regions, our approach mimics the Backus-Gilbert method where data are combined to focus sensitivity in a target region. This concept is illustrated using rotational ground motion measurements as fundamental observables. Forcing dominant sensitivity in the near-receiver region produces an observable that is insensitive to the Earth structure at more than a few wavelengths' distance from the receiver. This observable may be used for local tomography with teleseismic data. While our test examples use a small number of well-understood fundamental observables, few parameter classes and a radially symmetric earth model, the method itself does not impose such restrictions. It can easily be applied to large numbers of fundamental observables and parameters classes, as well as to 3-D heterogeneous earth models.

SiC-VJFETs power switching devices: an improved model and parameter optimization technique

NASA Astrophysics Data System (ADS)

Ben Salah, T.; Lahbib, Y.; Morel, H.

2009-12-01

Silicon carbide junction field effect transistor (SiC-JFETs) is a mature power switch newly applied in several industrial applications. SiC-JFETs are often simulated by Spice model in order to predict their electrical behaviour. Although such a model provides sufficient accuracy for some applications, this paper shows that it presents serious shortcomings in terms of the neglect of the body diode model, among many others in circuit model topology. Simulation correction is then mandatory and a new model should be proposed. Moreover, this paper gives an enhanced model based on experimental dc and ac data. New devices are added to the conventional circuit model giving accurate static and dynamic behaviour, an effect not accounted in the Spice model. The improved model is implemented into VHDL-AMS language and steady-state dynamic and transient responses are simulated for many SiC-VJFETs samples. Very simple and reliable optimization algorithm based on the optimization of a cost function is proposed to extract the JFET model parameters. The obtained parameters are verified by comparing errors between simulations results and experimental data.

Simultaneous spectrophotometric determination of synthetic dyes in food samples after cloud point extraction using multiple response optimizations.

PubMed

Heidarizadi, Elham; Tabaraki, Reza

2016-01-01

A sensitive cloud point extraction method for simultaneous determination of trace amounts of sunset yellow (SY), allura red (AR) and brilliant blue (BB) by spectrophotometry was developed. Experimental parameters such as Triton X-100 concentration, KCl concentration and initial pH on extraction efficiency of dyes were optimized using response surface methodology (RSM) with a Doehlert design. Experimental data were evaluated by applying RSM integrating a desirability function approach. The optimum condition for extraction efficiency of SY, AR and BB simultaneously were: Triton X-100 concentration 0.0635 mol L(-1), KCl concentration 0.11 mol L(-1) and pH 4 with maximum overall desirability D of 0.95. Correspondingly, the maximum extraction efficiency of SY, AR and BB were 100%, 92.23% and 95.69%, respectively. At optimal conditions, extraction efficiencies were 99.8%, 92.48% and 95.96% for SY, AR and BB, respectively. These values were only 0.2%, 0.25% and 0.27% different from the predicted values, suggesting that the desirability function approach with RSM was a useful technique for simultaneously dye extraction. Linear calibration curves were obtained in the range of 0.02-4 for SY, 0.025-2.5 for AR and 0.02-4 μg mL(-1) for BB under optimum condition. Detection limit based on three times the standard deviation of the blank (3Sb) was 0.009, 0.01 and 0.007 μg mL(-1) (n=10) for SY, AR and BB, respectively. The method was successfully used for the simultaneous determination of the dyes in different food samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Enzyme-assisted supercritical carbon dioxide extraction of black pepper oleoresin for enhanced yield of piperine-rich extract.

PubMed

Dutta, Sayantani; Bhattacharjee, Paramita

2015-07-01

Black pepper (Piper nigrum L.), the King of Spices is the most popular spice globally and its active ingredient, piperine, is reportedly known for its therapeutic potency. In this work, enzyme-assisted supercritical carbon dioxide (SC-CO2) extraction of black pepper oleoresin was investigated using α-amylase (from Bacillus licheniformis) for enhanced yield of piperine-rich extract possessing good combination of phytochemical properties. Optimization of the extraction parameters (without enzyme), mainly temperature and pressure, was conducted in both batch and continuous modes and the optimized conditions that provided the maximum yield of piperine was in the batch mode, with a sample size of 20 g of black pepper powder (particle diameter 0.42 ± 0.02 mm) at 60 °C and 300 bar at 2 L/min of CO2 flow. Studies on activity of α-amylase were conducted under these optimized conditions in both batch and continuous modes, with varying amounts of lyophilized enzyme (2 mg, 5 mg and 10 mg) and time of exposure of the enzyme to SC-CO2 (2.25 h and 4.25 h). The specific activity of the enzyme increased by 2.13 times when treated in the continuous mode than in the batch mode (1.25 times increase). The structural changes of the treated enzymes were studied by (1)H NMR analyses. In case of α-amylase assisted extractions of black pepper, both batch and continuous modes significantly increased the yields and phytochemical properties of piperine-rich extracts; with higher increase in batch mode than in continuous. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Microwave-Assisted Extraction of Phenolic Compounds from Almond Skin Byproducts (Prunus amygdalus): A Multivariate Analysis Approach.

PubMed

Valdés, Arantzazu; Vidal, Lorena; Beltrán, Ana; Canals, Antonio; Garrigós, María Carmen

2015-06-10

A microwave-assisted extraction (MAE) procedure to isolate phenolic compounds from almond skin byproducts was optimized. A three-level, three-factor Box-Behnken design was used to evaluate the effect of almond skin weight, microwave power, and irradiation time on total phenolic content (TPC) and antioxidant activity (DPPH). Almond skin weight was the most important parameter in the studied responses. The best extraction was achieved using 4 g, 60 s, 100 W, and 60 mL of 70% (v/v) ethanol. TPC, antioxidant activity (DPPH, FRAP), and chemical composition (HPLC-DAD-ESI-MS/MS) were determined by using the optimized method from seven different almond cultivars. Successful discrimination was obtained for all cultivars by using multivariate linear discriminant analysis (LDA), suggesting the influence of cultivar type on polyphenol content and antioxidant activity. The results show the potential of almond skin as a natural source of phenolics and the effectiveness of MAE for the reutilization of these byproducts.

Agarose-chitosan-C18 film micro-solid phase extraction combined with high performance liquid chromatography for the determination of phenanthrene and pyrene in chrysanthemum tea samples.

PubMed

Ng, Nyuk Ting; Sanagi, Mohd Marsin; Wan Ibrahim, Wan Nazihah; Wan Ibrahim, Wan Aini

2017-05-01

Agarose-chitosan-immobilized octadecylsilyl-silica (C 18 ) film micro-solid phase extraction (μSPE) was developed and applied for the determination of phenanthrene (PHE) and pyrene (PYR) in chrysanthemum tea samples using high performance liquid chromatography-ultraviolet detection (HPLC-UV). The film of blended agarose and chitosan allows good dispersion of C 18 , prevents the leaching of C 18 during application and enhances the film mechanical stability. Important μSPE parameters were optimized including amount of sorbent loading, extraction time, desorption solvent and desorption time. The matrix match calibration curves showed good linearity (r⩾0.994) over a concentration range of 1-500ppb. Under the optimized conditions, the proposed method showed good limits of detection (0.549-0.673ppb), good analyte recoveries (100.8-105.99%) and good reproducibilities (RSDs⩽13.53%, n=3) with preconcentration factors of 4 and 72 for PHE and PYR, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of matrix effects on methyl benzoate, a potential biomarker for detection of outgassed semi-volatiles from mold in indoor building materials.

PubMed

Parkinson, Don-Roger; Churchill, Tonia J; Rolls, Wyn

2008-11-01

Methyl benzoate - as a biomarker for mold growth - was used as a specific target compound to indicate outgassed MVOC products from mold. Both real and surrogate samples were analyzed from a variety of matrices including: carpet, ceiling tiles, dried paint surfaces, wallboard and wallboard paper. Sampling parameters, including: desorption, extraction time, incubation temperature, pH, salt effects and spinning rate, were optimized. Results suggest that extraction and detection of methyl benzoate amongst other MVOCs can be accomplished cleanly by SPME-GC/MS methods. With detection limits (LOD = 1.5 ppb) and linearity (0.999) over a range of 100 ppm to 2 ppb, this work demonstrates that such a green technique can be contemplated for use in quick assessment or as part of an ongoing assessment strategy to detect mold growth in common indoor buildings and materials for both qualitative and quantitative determinations. Of importance, no matrix effects are observed under optimized extraction conditions.

Optimization of Polycyclic Aromatic Hydrocarbon (PAH) Extraction Efficiency Parameters for Sub- and Supercritical Water Extraction (SCWE) Instrument

NASA Technical Reports Server (NTRS)

Okada, Asahi A.

2005-01-01

Polycyclic aromatic hydrocarbons are a class of molecules composed of multiple, bonded benzene rings. As PAHS are believed to be present on Mars, positive confirmation of their presence on Mars is highly desirable. To extract PAHS, which have low volatility, a fluid extraction method is ideal, and one that does not utilize organic solvents is especially ideal for in situ instrumental analysis. The use of water as a solvent, which at subcritical pressures and temperatures is relatively non-Polar, has significant potential. As SCWE instruments have not yet been commercialized, all instruments are individually-built research prototypes: thus, initial efforts were intended to determine if extraction efficiencies on the JPL-built laboratory-scale SCWE instrument are comparable to differing designs built elsewhere. Samples of soil with certified reference concentrations of PAHs were extracted using SCWE as well as conventional Soxhlet extraction. Continuation of the work would involve extractions on JPL'S newer, portable SCWE instrument prototype to determine its efficiency in extracting PAHs.

Selective Extraction of Flavonoids from Sophora flavescens Ait. by Mechanochemistry.

PubMed

Zhang, Qihong; Yu, Jingbo; Wang, Yingyao; Su, Weike

2016-07-29

Flavonoids from Sophora flavescens were selectively extracted by mechanochemical-promoted extraction technology (MPET) after using response surface methodology to determine the optimal extraction parameters. The highest yield of 35.17 mg/g was achieved by grinding the roots with Na₂CO₃ (15%) at 440 rpm/min for 17.0 min and water was used as the sole solvent with a ratio of solvent to solid material of 25 mL/g. Flavonoids prepared by MPET demonstrated relatively higher antioxidant activities in subsequent DPPH and hydroxyl radical scavenging assays. Main constituents in the extracts, including kurarinol, kushenol I/N and kurarinone, were characterized by HPLC-MS/MS, indicating good selective extraction by MPET. Physicochemical property changes of powder during mechanochemical milling were identified by scanning electron microscopy, X-ray powder diffraction, and UV-Vis diffuse-reflectance spectroscopy. Compared with traditional extraction methods, MPET possesses notable advantages of higher selectivity, lower extraction temperature, shorter extraction time, and organic solvent free properties.

Dual-cloud point extraction coupled to high performance liquid chromatography for simultaneous determination of trace sulfonamide antimicrobials in urine and water samples.

PubMed

Nong, Chunyan; Niu, Zongliang; Li, Pengyao; Wang, Chunping; Li, Wanyu; Wen, Yingying

2017-04-15

Dual-cloud point extraction (dCPE) was successfully developed for simultaneous extraction of trace sulfonamides (SAs) including sulfamerazine (SMZ), sulfadoxin (SDX), sulfathiazole (STZ) in urine and water samples. Several parameters affecting the extraction were optimized, such as sample pH, concentration of Triton X-114, extraction temperature and time, centrifugation rate and time, back-extraction solution pH, back-extraction temperature and time, back-extraction centrifugation rate and time. High performance liquid chromatography (HPLC) was applied for the SAs analysis. Under the optimum extraction and detection conditions, successful separation of the SAs was achieved within 9min, and excellent analytical performances were attained. Good linear relationships (R 2 ≥0.9990) between peak area and concentration for SMZ and STZ were optimized from 0.02 to 10μg/mL, for SDX from 0.01 to 10μg/mL. Detection limits of 3.0-6.2ng/mL were achieved. Satisfactory recoveries ranging from 85 to 108% were determined with urine, lake and tap water spiked at 0.2, 0.5 and 1μg/mL, respectively, with relative standard deviations (RSDs, n=6) of 1.5-7.7%. This method was demonstrated to be convenient, rapid, cost-effective and environmentally benign, and could be used as an alternative tool to existing methods for analysing trace residues of SAs in urine and water samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Determination of fluoroquinolone antibiotics via ionic-liquid-based, salt-induced, dual microextraction in swine feed.

PubMed

Wang, Huili; Gao, Ming; Gao, Jiajia; Yu, Nana; Huang, Hong; Yu, Qing; Wang, Xuedong

2016-09-01

In conventional microextraction procedures, the disperser (organic solvent or ionic liquid) is left in the aqueous phase and discarded after finishing the microextraction process. Because the disperser is water-soluble, it results in low extraction recovery for polar compounds. In this investigation, an ionic-liquid-based microextraction (ILBME) was integrated with salting-out assisted liquid-liquid microextraction (SALLME) to build an ionic-liquid-based, salt-induced, dual microextraction (ILSDME) for isolation of five fluoroquinolone antibiotics (FQs) with high polarity (log P, -1.0 to 1.0). The proposed ILSDME method incorporates a dual microextraction by converting the disperser in the ILBME to the extractor in the SALLME. Optimization of key factors was conducted by integrating single-factor experiments and central composite design. The optimized experimental parameters were 80 μL [C8MIM][PF6] as extractor, 505 μL acetone as disperser, pH = 2.0, 4.1 min extraction time, and 4.2 g of Na2SO4. Under optimized conditions, high ERs (90.6-103.2 %) and low LODs (0.07-0.61 μg kg(-1)) were determined for five FQs in swine feed. Experimental precision based on RSDs was 1.4-5.2 % for intra-day and 2.4-6.9 % for inter-day analyses. The combination of ILBME with SALLME increased FQ recoveries by 15-20 % as compared with SALLME, demonstrating that the ILSDME method can enhance extraction efficiency for polar compounds compared to single-step microextraction. Therefore, the ILSDME method developed in this study has wide application for pretreatment of moderately to highly polar pollutants in complex matrices. Graphical Abstract A dual microextraction was developed by integrating ionic-liquid-based microextraction with salting-out assisted liquid-liquid microextraction for isolation of five fluoroquinolone antibiotics (FQs) with high polarity (log P = -1.0 to 1.0). The principle of dual microextraction is based on converting the remaining disperser from the first microextraction into an extractor in the second microextraction. Single-factor experiment and central composite design were applied for optimizing operational parameters using 3D response surfaces and contour lines. Under optimized conditions, the method provided high extraction recoveries and low LODs for five FQs in swine feed. The prominent advantage of the dual microextraction is rapid and highly efficient extraction of moderately to highly polar fluoroquinolones from complex matrices.

Detecting epileptic seizure with different feature extracting strategies using robust machine learning classification techniques by applying advance parameter optimization approach.

PubMed

Hussain, Lal

2018-06-01

Epilepsy is a neurological disorder produced due to abnormal excitability of neurons in the brain. The research reveals that brain activity is monitored through electroencephalogram (EEG) of patients suffered from seizure to detect the epileptic seizure. The performance of EEG detection based epilepsy require feature extracting strategies. In this research, we have extracted varying features extracting strategies based on time and frequency domain characteristics, nonlinear, wavelet based entropy and few statistical features. A deeper study was undertaken using novel machine learning classifiers by considering multiple factors. The support vector machine kernels are evaluated based on multiclass kernel and box constraint level. Likewise, for K-nearest neighbors (KNN), we computed the different distance metrics, Neighbor weights and Neighbors. Similarly, the decision trees we tuned the paramours based on maximum splits and split criteria and ensemble classifiers are evaluated based on different ensemble methods and learning rate. For training/testing tenfold Cross validation was employed and performance was evaluated in form of TPR, NPR, PPV, accuracy and AUC. In this research, a deeper analysis approach was performed using diverse features extracting strategies using robust machine learning classifiers with more advanced optimal options. Support Vector Machine linear kernel and KNN with City block distance metric give the overall highest accuracy of 99.5% which was higher than using the default parameters for these classifiers. Moreover, highest separation (AUC = 0.9991, 0.9990) were obtained at different kernel scales using SVM. Additionally, the K-nearest neighbors with inverse squared distance weight give higher performance at different Neighbors. Moreover, to distinguish the postictal heart rate oscillations from epileptic ictal subjects, and highest performance of 100% was obtained using different machine learning classifiers.

Endmember extraction from hyperspectral image based on discrete firefly algorithm (EE-DFA)

NASA Astrophysics Data System (ADS)

Zhang, Chengye; Qin, Qiming; Zhang, Tianyuan; Sun, Yuanheng; Chen, Chao

2017-04-01

This study proposed a novel method to extract endmembers from hyperspectral image based on discrete firefly algorithm (EE-DFA). Endmembers are the input of many spectral unmixing algorithms. Hence, in this paper, endmember extraction from hyperspectral image is regarded as a combinational optimization problem to get best spectral unmixing results, which can be solved by the discrete firefly algorithm. Two series of experiments were conducted on the synthetic hyperspectral datasets with different SNR and the AVIRIS Cuprite dataset, respectively. The experimental results were compared with the endmembers extracted by four popular methods: the sequential maximum angle convex cone (SMACC), N-FINDR, Vertex Component Analysis (VCA), and Minimum Volume Constrained Nonnegative Matrix Factorization (MVC-NMF). What's more, the effect of the parameters in the proposed method was tested on both synthetic hyperspectral datasets and AVIRIS Cuprite dataset, and the recommended parameters setting was proposed. The results in this study demonstrated that the proposed EE-DFA method showed better performance than the existing popular methods. Moreover, EE-DFA is robust under different SNR conditions.

Detergentless ultrasound-assisted extraction of trace elements from edible oils using lipase as an extractant.

PubMed

Kara, Derya; Fisher, Andrew; Hill, Steve

2015-11-01

A new method for the extraction and preconcentration of trace elements (Al, Ba, Cd, Cu, Fe, Mn, Mo, Ni, Ti, V and Zn) from edible oils by producing detergentless micro-emulsions via an ultrasound-assisted extraction using a water phase containing Lipase at pH 3 as an extractant was developed. The trace elements in the water phase post-extraction were determined against matrix matched standards using ICP-MS. In the first step of the work, the parameters that affect extraction, such as pH, the volume of 1% lipase in the water phase and the ultrasonic and centrifugation times were optimized. Under the optimal conditions, the detection limits (µg kg(-1)) were 0.46, 0.03, 0.007, 0.028, 0.67, 0.038, 0.022, 0.14, 0.17, 0.05 and 0.07 for Al, Ba, Cd, Cu, Fe, Mn, Mo, Ni, Ti, V and Zn respectively for edible oils (3 Sb/m). A certified reference material (EnviroMAT HU-1 Used oil) was analysed to check the accuracy of the developed method. Results obtained were in agreement with certified values with a t-test showing that no significant differences at the 95% confidence levels were found. The proposed method was applied to different edible oils such as sunflower oil, rapeseed oil, olive oil and salmon oil. Copyright © 2015 Elsevier B.V. All rights reserved.

Accelerated solvent extraction combined with dispersive liquid-liquid microextraction before gas chromatography with mass spectrometry for the sensitive determination of phenols in soil samples.

PubMed

Xing, Han-Zhu; Wang, Xia; Chen, Xiang-Feng; Wang, Ming-Lin; Zhao, Ru-Song

2015-05-01

A method combining accelerated solvent extraction with dispersive liquid-liquid microextraction was developed for the first time as a sample pretreatment for the rapid analysis of phenols (including phenol, m-cresol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol) in soil samples. In the accelerated solvent extraction procedure, water was used as an extraction solvent, and phenols were extracted from soil samples into water. The dispersive liquid-liquid microextraction technique was then performed on the obtained aqueous solution. Important accelerated solvent extraction and dispersive liquid-liquid microextraction parameters were investigated and optimized. Under optimized conditions, the new method provided wide linearity (6.1-3080 ng/g), low limits of detection (0.06-1.83 ng/g), and excellent reproducibility (<10%) for phenols. Four real soil samples were analyzed by the proposed method to assess its applicability. Experimental results showed that the soil samples were free of our target compounds, and average recoveries were in the range of 87.9-110%. These findings indicate that accelerated solvent extraction with dispersive liquid-liquid microextraction as a sample pretreatment procedure coupled with gas chromatography and mass spectrometry is an excellent method for the rapid analysis of trace levels of phenols in environmental soil samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid Synthesis of Silver Nanoparticles from Fusarium oxysporum by Optimizing Physicocultural Conditions

PubMed Central

Birla, Sonal S.; Gaikwad, Swapnil C.; Gade, Aniket K.; Rai, Mahendra K.

2013-01-01

Synthesis of silver nanoparticles (SNPs) by fungi is emerging as an important branch of nanotechnology due to its ecofriendly, safe, and cost-effective nature. In order to increase the yield of biosynthesized SNPs of desired shape and size, it is necessary to control the cultural and physical parameters during the synthesis. We report optimum synthesis of SNPs on malt extract glucose yeast extract peptone (MGYP) medium at pH 9–11, 40–60°C, and 190.7 Lux and in sun light. The salt concentrations, volume of filtrate and biomass quantity were found to be directly proportional to the yield. The optimized conditions for the stable and rapid synthesis will help in large scale synthesis of monodispersed SNPs. The main aim of the present study was to optimize different media, temperature, pH, light intensity, salt concentration, volume of filtrate, and biomass quantity for the synthesis of SNPs by Fusarium oxysporum. PMID:24222751

Determination of volatile marker compounds in raw ham using headspace-trap gas chromatography.

PubMed

Bosse Née Danz, Ramona; Wirth, Melanie; Konstanz, Annette; Becker, Thomas; Weiss, Jochen; Gibis, Monika

2017-03-15

A simple, reliable and automated method was developed and optimized for qualification and quantification of aroma-relevant volatile marker compounds of North European raw ham using a headspace (HS)-Trap gas chromatography-mass spectrometry (GC-MS) and GC-flame ionization detector (FID) analysis. A total of 38 volatile compounds were detected with this HS-Trap GC-MS method amongst which the largest groups were ketones (12), alcohols (8), hydrocarbons (7), aldehydes (6) and esters (3). The HS-Trap GC-FID method was optimized for the parameters: thermostatting time and temperature, vial and desorption pressure, number of extraction cycles and salt addition. A validation for 13 volatile marker compounds with limits of detection in ng/g was carried out. The optimized method can serve as alternative to conventional headspace and solid phase micro extraction methods and allows users to determine volatile compounds in raw hams making it of interest to industrial and academic meat scientists. Copyright © 2016 Elsevier Ltd. All rights reserved.

Simultaneous parameter optimization of x-ray and neutron reflectivity data using genetic algorithms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Surendra, E-mail: surendra@barc.gov.in; Basu, Saibal

2016-05-23

X-ray and neutron reflectivity are two non destructive techniques which provide a wealth of information on thickness, structure and interracial properties in nanometer length scale. Combination of X-ray and neutron reflectivity is well suited for obtaining physical parameters of nanostructured thin films and superlattices. Neutrons provide a different contrast between the elements than X-rays and are also sensitive to the magnetization depth profile in thin films and superlattices. The real space information is extracted by fitting a model for the structure of the thin film sample in reflectometry experiments. We have applied a Genetic Algorithms technique to extract depth dependentmore » structure and magnetic in thin film and multilayer systems by simultaneously fitting X-ray and neutron reflectivity data.« less

A Unified Fisher's Ratio Learning Method for Spatial Filter Optimization.

PubMed

Li, Xinyang; Guan, Cuntai; Zhang, Haihong; Ang, Kai Keng

To detect the mental task of interest, spatial filtering has been widely used to enhance the spatial resolution of electroencephalography (EEG). However, the effectiveness of spatial filtering is undermined due to the significant nonstationarity of EEG. Based on regularization, most of the conventional stationary spatial filter design methods address the nonstationarity at the cost of the interclass discrimination. Moreover, spatial filter optimization is inconsistent with feature extraction when EEG covariance matrices could not be jointly diagonalized due to the regularization. In this paper, we propose a novel framework for a spatial filter design. With Fisher's ratio in feature space directly used as the objective function, the spatial filter optimization is unified with feature extraction. Given its ratio form, the selection of the regularization parameter could be avoided. We evaluate the proposed method on a binary motor imagery data set of 16 subjects, who performed the calibration and test sessions on different days. The experimental results show that the proposed method yields improvement in classification performance for both single broadband and filter bank settings compared with conventional nonunified methods. We also provide a systematic attempt to compare different objective functions in modeling data nonstationarity with simulation studies.To detect the mental task of interest, spatial filtering has been widely used to enhance the spatial resolution of electroencephalography (EEG). However, the effectiveness of spatial filtering is undermined due to the significant nonstationarity of EEG. Based on regularization, most of the conventional stationary spatial filter design methods address the nonstationarity at the cost of the interclass discrimination. Moreover, spatial filter optimization is inconsistent with feature extraction when EEG covariance matrices could not be jointly diagonalized due to the regularization. In this paper, we propose a novel framework for a spatial filter design. With Fisher's ratio in feature space directly used as the objective function, the spatial filter optimization is unified with feature extraction. Given its ratio form, the selection of the regularization parameter could be avoided. We evaluate the proposed method on a binary motor imagery data set of 16 subjects, who performed the calibration and test sessions on different days. The experimental results show that the proposed method yields improvement in classification performance for both single broadband and filter bank settings compared with conventional nonunified methods. We also provide a systematic attempt to compare different objective functions in modeling data nonstationarity with simulation studies.

Determination of T-2 and HT-2 toxins from maize by direct analysis in real time mass spectrometry

USDA-ARS?s Scientific Manuscript database

Direct analysis in real time (DART) ionization coupled to mass spectrometry (MS) was used for the rapid quantitative analysis of T-2 toxin, and the related HT-2 toxin, extracted from corn. Sample preparation procedures and instrument parameters were optimized to obtain sensitive and accurate determi...

An optimal control framework for dynamic induction control of wind farms and their interaction with the atmospheric boundary layer.

PubMed

Munters, W; Meyers, J

2017-04-13

Complex turbine wake interactions play an important role in overall energy extraction in large wind farms. Current control strategies optimize individual turbine power, and lead to significant energy losses in wind farms compared with lone-standing wind turbines. In recent work, an optimal coordinated control framework was introduced (Goit & Meyers 2015 J. Fluid Mech. 768 , 5-50 (doi:10.1017/jfm.2015.70)). Here, we further elaborate on this framework, quantify the influence of optimization parameters and introduce new simulation results for which gains in power production of up to 21% are observed.This article is part of the themed issue 'Wind energy in complex terrains'. © 2017 The Authors.

An optimal control framework for dynamic induction control of wind farms and their interaction with the atmospheric boundary layer

PubMed Central

Munters, W.

2017-01-01

Complex turbine wake interactions play an important role in overall energy extraction in large wind farms. Current control strategies optimize individual turbine power, and lead to significant energy losses in wind farms compared with lone-standing wind turbines. In recent work, an optimal coordinated control framework was introduced (Goit & Meyers 2015 J. Fluid Mech. 768, 5–50 (doi:10.1017/jfm.2015.70)). Here, we further elaborate on this framework, quantify the influence of optimization parameters and introduce new simulation results for which gains in power production of up to 21% are observed. This article is part of the themed issue ‘Wind energy in complex terrains’. PMID:28265024

A novel approach for extracting viscoelastic parameters of living cells through combination of inverse finite element simulation and Atomic Force Microscopy.

PubMed

Wei, Fanan; Yang, Haitao; Liu, Lianqing; Li, Guangyong

2017-03-01

Dynamic mechanical behaviour of living cells has been described by viscoelasticity. However, quantitation of the viscoelastic parameters for living cells is far from sophisticated. In this paper, combining inverse finite element (FE) simulation with Atomic Force Microscope characterization, we attempt to develop a new method to evaluate and acquire trustworthy viscoelastic index of living cells. First, influence of the experiment parameters on stress relaxation process is assessed using FE simulation. As suggested by the simulations, cell height has negligible impact on shape of the force-time curve, i.e. the characteristic relaxation time; and the effect originates from substrate can be totally eliminated when stiff substrate (Young's modulus larger than 3 GPa) is used. Then, so as to develop an effective optimization strategy for the inverse FE simulation, the parameters sensitivity evaluation is performed for Young's modulus, Poisson's ratio, and characteristic relaxation time. With the experiment data obtained through typical stress relaxation measurement, viscoelastic parameters are extracted through the inverse FE simulation by comparing the simulation results and experimental measurements. Finally, reliability of the acquired mechanical parameters is verified with different load experiments performed on the same cell.

Assay Development Process | Office of Cancer Clinical Proteomics Research

Cancer.gov

Typical steps involved in the development of a  mass spectrometry-based targeted assay include: (1) selection of surrogate or signature peptides corresponding to the targeted protein or modification of interest; (2) iterative optimization of instrument and method parameters for optimal detection of the selected peptide; (3) method development for protein extraction from biological matrices such as tissue, whole cell lysates, or blood plasma/serum and proteolytic digestion of proteins (usually with trypsin); (4) evaluation of the assay in the intended biological matrix to determine if e

On the use of ANN interconnection weights in optimal structural design

NASA Technical Reports Server (NTRS)

Hajela, P.; Szewczyk, Z.

1992-01-01

The present paper describes the use of interconnection weights of a multilayer, feedforward network, to extract information pertinent to the mapping space that the network is assumed to represent. In particular, these weights can be used to determine an appropriate network architecture, and an adequate number of training patterns (input-output pairs) have been used for network training. The weight analysis also provides an approach to assess the influence of each input parameter on a selected output component. The paper shows the significance of this information in decomposition driven optimal design.

Effective and sensitive determination of eleven disinfection byproducts in drinking water by DLLME and GC-MS.

PubMed

On, Jiwon; Pyo, Heesoo; Myung, Seung-Woon

2018-10-15

The aim of this study was to optimize the dispersive liquid-liquid microextraction (DLLME) parameters for simultaneous analysis through DLLME-gas chromatography-mass spectrometry (GC-MS) of six iodo-trihalomethanes, four haloacetonitriles, and one halonitromethane, which are residual disinfection products found in drinking water. Eleven disinfection by-product (DBPs) remaining in aqueous samples were extracted and concentrated using a simple, rapid, and environmentally friendly DLLME method, and then analyzed simultaneously by GC-MS. The optimized DLLME parameters were a sample volume of 5 mL, 100 μL of dichloromethane as the extraction solvent, 1 mL of methanol as the dispersion solvent, an extraction time of 60 s, and 1.5 g of sodium chloride for the salting out effect. The enrichment factor values obtained using the established DLLME-GC-MS method were 19.8-141.5, and the limit of detection and limit of quantification were 0.22-1.19 μg/L and 0.75-3.98 μg/L, respectively. The calibration curves had correlation coefficients (r 2 ) of 0.9958-0.9992 in the concentration range of 0.5-40 μg/L, and they exhibited good linearity in quantitative analysis. This new method could be useful for analyzing eleven DBPs that remain in drinking water. Copyright © 2018 Elsevier B.V. All rights reserved.

Insights on beer volatile profile: Optimization of solid-phase microextraction procedure taking advantage of the comprehensive two-dimensional gas chromatography structured separation.

PubMed

Martins, Cátia; Brandão, Tiago; Almeida, Adelaide; Rocha, Sílvia M

2015-06-01

The aroma profile of beer is crucial for its quality and consumer acceptance, which is modu-lated by a network of variables. The main goal of this study was to optimize solid-phase microextraction experimental parameters (fiber coating, extraction temperature, and time), taking advantage of the comprehensive two-dimensional gas chromatography structured separation. As far as we know, it is the first time that this approach was used to the untargeted and comprehensive study of the beer volatile profile. Decarbonation is a critical sample preparation step, and two conditions were tested: static and under ultrasonic treatment, and the static condition was selected. Considering the conditions that promoted the highest extraction efficiency, the following parameters were selected: poly(dimethylsiloxane)/divinylbenzene fiber coating, at 40ºC, using 10 min of pre-equilibrium followed by 30 min of extraction. Around 700-800 compounds per sample were detected, corresponding to the beer volatile profile. An exploratory application was performed with commercial beers, using a set of 32 compounds with reported impact on beer aroma, in which different patterns can be observed through the structured chromatogram. In summary, the obtained results emphasize the potential of this methodology to allow an in-depth study of volatile molecular composition of beer. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Extraction of chemical warfare agents from water with hydrophilic-lipophilic balance and C18 cartridges: comparative study.

PubMed

Kanaujia, Pankaj K; Pardasani, Deepak; Gupta, A K; Dubey, D K

2007-01-19

Efficient extraction of chemical warfare agents (CWAs) from water is essential before subjecting them to gas chromatographic and spectral analysis aiming towards verification of the Chemical Weapons Convention (CWC). It requires development of fast, reliable, simple and reproducible sample preparation of CWAs from water which is likely to be contaminated during deliberate or inadvertent spread of CWAs. This work describes development of a solid-phase extraction method using hydrophilic-lipophilic balance (HLB) cartridges for extraction of CWAs from water. The extraction efficiencies of HLB and C18 cartridges were compared and the results revealed that HLB sorbents performed better. Extracts were analyzed by gas chromatography-mass spectrometry. Extraction parameters, such as extraction solvent, its volume and rinsing solvent were optimized. Best recoveries of target analytes were obtained using 1mL methanol and limits of detection were achieved up to 0.05microg/mL with dichloromethane. Precision of the method was found to be less than 9.2% RSD.

Microgravimetric Analysis Method for Activation-Energy Extraction from Trace-Amount Molecule Adsorption.

PubMed

Xu, Pengcheng; Yu, Haitao; Li, Xinxin

2016-05-03

Activation-energy (Ea) value for trace-amount adsorption of gas molecules on material is rapidly and inexpensively obtained, for the first time, from a microgravimetric analysis experiment. With the material loaded, a resonant microcantilever is used to record in real time the adsorption process at two temperatures. The kinetic parameter Ea is thereby extracted by solving the Arrhenius equation. As an example, two CO2 capture nanomaterials are examined by the Ea extracting method for evaluation/optimization and, thereby, demonstrating the applicability of the microgravimetric analysis method. The achievement helps to solve the absence in rapid quantitative characterization of sorption kinetics and opens a new route to investigate molecule adsorption processes and materials.

Hierarchical Bayesian Model Averaging for Chance Constrained Remediation Designs

NASA Astrophysics Data System (ADS)

Chitsazan, N.; Tsai, F. T.

2012-12-01

Groundwater remediation designs are heavily relying on simulation models which are subjected to various sources of uncertainty in their predictions. To develop a robust remediation design, it is crucial to understand the effect of uncertainty sources. In this research, we introduce a hierarchical Bayesian model averaging (HBMA) framework to segregate and prioritize sources of uncertainty in a multi-layer frame, where each layer targets a source of uncertainty. The HBMA framework provides an insight to uncertainty priorities and propagation. In addition, HBMA allows evaluating model weights in different hierarchy levels and assessing the relative importance of models in each level. To account for uncertainty, we employ a chance constrained (CC) programming for stochastic remediation design. Chance constrained programming was implemented traditionally to account for parameter uncertainty. Recently, many studies suggested that model structure uncertainty is not negligible compared to parameter uncertainty. Using chance constrained programming along with HBMA can provide a rigorous tool for groundwater remediation designs under uncertainty. In this research, the HBMA-CC was applied to a remediation design in a synthetic aquifer. The design was to develop a scavenger well approach to mitigate saltwater intrusion toward production wells. HBMA was employed to assess uncertainties from model structure, parameter estimation and kriging interpolation. An improved harmony search optimization method was used to find the optimal location of the scavenger well. We evaluated prediction variances of chloride concentration at the production wells through the HBMA framework. The results showed that choosing the single best model may lead to a significant error in evaluating prediction variances for two reasons. First, considering the single best model, variances that stem from uncertainty in the model structure will be ignored. Second, considering the best model with non-dominant model weight may underestimate or overestimate prediction variances by ignoring other plausible propositions. Chance constraints allow developing a remediation design with a desirable reliability. However, considering the single best model, the calculated reliability will be different from the desirable reliability. We calculated the reliability of the design for the models at different levels of HBMA. The results showed that by moving toward the top layers of HBMA, the calculated reliability converges to the chosen reliability. We employed the chance constrained optimization along with the HBMA framework to find the optimal location and pumpage for the scavenger well. The results showed that using models at different levels in the HBMA framework, the optimal location of the scavenger well remained the same, but the optimal extraction rate was altered. Thus, we concluded that the optimal pumping rate was sensitive to the prediction variance. Also, the prediction variance was changed by using different extraction rate. Using very high extraction rate will cause prediction variances of chloride concentration at the production wells to approach zero regardless of which HBMA models used.

Accelerated solvent extraction combined with solid phase extraction for the determination of organophosphate esters from sewage sludge compost by UHPLC-MS/MS.

PubMed

Pang, Long; Yang, Peijie; Ge, Liming; Du, Jingjing; Zhang, Hongzhong

2017-02-01

Organophosphate esters (OPEs), widely used as flame retardants and plasticizers, are regarded as emerging pollutants. OPEs are prone to concentrate into residual activated sludge, which might cause secondary pollution if not suitably treated. Composting is an economical and effective approach to make sewage sludge stable and harmless. Therefore, it is essential to develop a novel method for analyzing OPEs in sewage sludge compost samples. However, in the composting process, large amounts of amendments are doped into the sludge to adjust the carbon-nitrogen ratio. Amendment has a strong capacity for adsorption and thus induces a decrease of extraction efficiency. This study developed a novel procedure for determining OPEs in compost samples. Accelerated solvent extraction (ASE) and solid phase extraction (SPE) were used for extracting and concentrating the OPEs from sewage sludge compost samples, and then analyzed by UHPLC-MS/MS. Some parameters were optimized in this study, mainly including the extraction solvent type, extraction temperature, static extraction time, extraction cycles, and flush volume. Under the optimal conditions, the proposed method showed good linearity between 0.50 and 100 μg kg -1 with regression coefficients in the range of 0.9984-0.9998. Detection limits were in the range of 0.02-3 μg kg -1 with standard deviations ranging from 2 to 6%. Acceptable recoveries between 56 and 119% for samples spiked at different concentration levels were achieved. In contrast, the recoveries merely ranged from 24 to 58% by using ultrasonic-assisted extraction. Graphical abstract A comparison of recoveries between ultrasonic-assisted extraction (UAS) and accelerated solvent extraction (ASE) for organophosphate esters from sewage sludge compost samples.

An optimized time varying filtering based empirical mode decomposition method with grey wolf optimizer for machinery fault diagnosis

NASA Astrophysics Data System (ADS)

Zhang, Xin; Liu, Zhiwen; Miao, Qiang; Wang, Lei

2018-03-01

A time varying filtering based empirical mode decomposition (EMD) (TVF-EMD) method was proposed recently to solve the mode mixing problem of EMD method. Compared with the classical EMD, TVF-EMD was proven to improve the frequency separation performance and be robust to noise interference. However, the decomposition parameters (i.e., bandwidth threshold and B-spline order) significantly affect the decomposition results of this method. In original TVF-EMD method, the parameter values are assigned in advance, which makes it difficult to achieve satisfactory analysis results. To solve this problem, this paper develops an optimized TVF-EMD method based on grey wolf optimizer (GWO) algorithm for fault diagnosis of rotating machinery. Firstly, a measurement index termed weighted kurtosis index is constructed by using kurtosis index and correlation coefficient. Subsequently, the optimal TVF-EMD parameters that match with the input signal can be obtained by GWO algorithm using the maximum weighted kurtosis index as objective function. Finally, fault features can be extracted by analyzing the sensitive intrinsic mode function (IMF) owning the maximum weighted kurtosis index. Simulations and comparisons highlight the performance of TVF-EMD method for signal decomposition, and meanwhile verify the fact that bandwidth threshold and B-spline order are critical to the decomposition results. Two case studies on rotating machinery fault diagnosis demonstrate the effectiveness and advantages of the proposed method.

A LiDAR data-based camera self-calibration method

NASA Astrophysics Data System (ADS)

Xu, Lijun; Feng, Jing; Li, Xiaolu; Chen, Jianjun

2018-07-01

To find the intrinsic parameters of a camera, a LiDAR data-based camera self-calibration method is presented here. Parameters have been estimated using particle swarm optimization (PSO), enhancing the optimal solution of a multivariate cost function. The main procedure of camera intrinsic parameter estimation has three parts, which include extraction and fine matching of interest points in the images, establishment of cost function, based on Kruppa equations and optimization of PSO using LiDAR data as the initialization input. To improve the precision of matching pairs, a new method of maximal information coefficient (MIC) and maximum asymmetry score (MAS) was used to remove false matching pairs based on the RANSAC algorithm. Highly precise matching pairs were used to calculate the fundamental matrix so that the new cost function (deduced from Kruppa equations in terms of the fundamental matrix) was more accurate. The cost function involving four intrinsic parameters was minimized by PSO for the optimal solution. To overcome the issue of optimization pushed to a local optimum, LiDAR data was used to determine the scope of initialization, based on the solution to the P4P problem for camera focal length. To verify the accuracy and robustness of the proposed method, simulations and experiments were implemented and compared with two typical methods. Simulation results indicated that the intrinsic parameters estimated by the proposed method had absolute errors less than 1.0 pixel and relative errors smaller than 0.01%. Based on ground truth obtained from a meter ruler, the distance inversion accuracy in the experiments was smaller than 1.0 cm. Experimental and simulated results demonstrated that the proposed method was highly accurate and robust.

Proteolytic enzymes from Bromelia antiacantha as tools for controlled tissue hydrolysis in entomology.

PubMed

Macció, Laura; Vallés, Diego; Cantera, Ana Maria

2013-12-01

A crude extract with high proteolytic activity (78.1 EU/mL), prepared from ripe fruit of Bromelia antiacantha was used to hydrolyze and remove soft tissues from the epigyne of Apopyllus iheringi. This enzymatic extract presented four actives isoforms which have a broad substrate specificity action. Enzyme action on samples was optimized after evaluation under different conditions of pH, enzyme-substrate ratio and time (parameters selected based on previous studies) of treatment (pH 4.0, 6.0 and 8.0 at 42°C with different amount of enzyme). Scanning electron microscopy was used to evaluate conditions resulting in complete digestion of epigyne soft tissues. Optimal conditions for soft tissue removal were 15.6 total enzyme units, pH 6.0 for 18 h at 42°C.

Simultaneous determination of phenolic compounds in Equisetum palustre L. by ultra high performance liquid chromatography with tandem mass spectrometry combined with matrix solid-phase dispersion extraction.

PubMed

Wei, Zuofu; Pan, Youzhi; Li, Lu; Huang, Yuyang; Qi, Xiaolin; Luo, Meng; Zu, Yuangang; Fu, Yujie

2014-11-01

A method based on matrix solid-phase dispersion extraction followed by ultra high performance liquid chromatography with tandem mass spectrometry is presented for the extraction and determination of phenolic compounds in Equisetum palustre. This method combines the high efficiency of matrix solid-phase dispersion extraction and the rapidity, sensitivity, and accuracy of ultra high performance liquid chromatography with tandem mass spectrometry. The influential parameters of the matrix solid-phase dispersion extraction were investigated and optimized. The optimized conditions were as follows: silica gel was selected as dispersing sorbent, the ratio of silica gel to sample was selected to be 2:1 (400/200 mg), and 8 mL of 80% methanol was used as elution solvent. Furthermore, a fast and sensitive ultra high performance liquid chromatography with tandem mass spectrometry method was developed for the determination of nine phenolic compounds in E. palustre. This method was carried out within <6 min, and exhibited satisfactory linearity, precision, and recovery. Compared with ultrasound-assisted extraction, the proposed matrix solid-phase dispersion procedure possessed higher extraction efficiency, and was more convenient and time saving with reduced requirements on sample and solvent amounts. All these results suggest that the developed method represents an excellent alternative for the extraction and determination of active components in plant matrices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cellulose extraction from orange peel using sulfite digestion reagents.

PubMed

Bicu, Ioan; Mustata, Fanica

2011-11-01

Orange peel (OP) was used as raw material for cellulose extraction. Two different pulping reagents were used, sodium sulfite and sodium metabisulfite. The effect of the main process parameters, sulfite agent dosage and reaction duration, on cellulose yield was investigated. A central composite rotatable design involving two variables at five levels and response surface methodology were used for the optimization of cellulose recovery. Other two invariable parameters were reaction temperature and hydromodulus. The optimum yields, referred to the weight of double extracted OP, were 40.4% and 45.2% for sodium sulfite and sodium metabisulfite digestions, respectively. The crude celluloses were bleached with hypochlorite and oxygen. The physicochemical characterization data of these cellulose materials indicate good levels of purity, low crystallinities, good whitenesses, good water retention and moderate molecular weights. According to these specific properties the recovered celluloses could be used as fillers, water absorbents, or as raw materials for cellulose derivatives. Copyright © 2011 Elsevier Ltd. All rights reserved.

Ultra-high performance liquid chromatography with fluorescence detection following salting-out assisted liquid-liquid extraction for the analysis of benzimidazole residues in farm fish samples.

PubMed

Tejada-Casado, Carmen; Lara, Francisco J; García-Campaña, Ana M; Del Olmo-Iruela, Monsalud

2018-03-30

Ultra-high performance liquid chromatography (UHPLC) coupled with fluorescence detection (FL) has been proposed for the first time to determine thirteen benzimidazoles (BZs) in farmed fish samples. In order to optimize the chromatographic separation, parameters such as mobile phase composition and flow rate were carefully studied, establishing a gradient mode with a mobile phase consisted of water (solvent A) and acetonitrile (solvent B) at a flow rate of 0.4 mL/min. The separation was performed on a Zorbax Eclipse Plus RRHD C 18 column (50 × 2.1 mm, 1.8 μm), involving a total analysis time lower than 12 min. Salting-out assisted liquid-liquid extraction (SALLE) was applied as sample treatment to different types of farmed fish (trout, sea bream and sea bass). To obtain satisfactory extraction efficiencies for the studied analytes, several parameters affecting the SALLE procedure were optimized including the amount of sample, type and volume of the extraction solvent, and the nature and amount of the salt used. Characterization of the method in terms of performance characteristics was carried out, obtaining satisfactory results for the linearity (R 2  ≥ 0.997), repeatability (RSD ≤ 6.1%), reproducibility (RSD ≤ 10.8%) and recoveries (R ≥ 79%; RSD ≤ 7.8%). Detection limits between 0.04-29.9 μg kg -1 were obtained, demonstrating the applicability of this fast, simple and environmentally friendly method. Copyright © 2018 Elsevier B.V. All rights reserved.

Extraction and preconcentration of residual solvents in pharmaceuticals using dynamic headspace-liquid phase microextraction and their determination by gas chromatography-flame ionization detection.

PubMed

Farajzadeh, Mir Ali; Dehghani, Hamideh; Yadeghari, Adeleh; Khoshmaram, Leila

2017-02-01

The present study describes a microextraction and determination method for analyzing residual solvents in pharmaceutical products using dynamic headspace-liquid phase microextraction technique followed by gas chromatography-flame ionization detection. In this method dimethyl sulfoxide (μL level) placed into a GC liner-shaped extraction vessel is used as a collection/extraction solvent. Then the liner is exposed to the headspace of a vial containing the sample solution. The effect of different parameters influencing the microextraction procedure including collection/extraction solvent type and its volume, ionic strength, extraction time, extraction temperature and concentration of NaOH solution used in dissolving the studied pharmaceuticals are investigated and optimized. Under the optimum extraction conditions, the method showed wide linear ranges between 0.5 and 5000 mg L -1 . The other analytical parameters were obtained in the following ranges: enrichment factors 240-327, extraction recoveries 72-98% and limits of detection 0.1-0.8 mg L -1 in solution and 0.6-3.2 μg g -1 in solid. Relative standard deviations for the extraction of 100 mg L -1 of each analyte were obtained in the ranges of 4-7 and 5-8% for intra-day (n = 6) and inter-day (n = 4) respectively. Finally the target analytes were determined in different samples such as erythromycin, azithromycin, cefalexin, amoxicillin and co-amoxiclav by the proposed method. Copyright © 2016 John Wiley & Sons, Ltd.

Production of Sterilizing Agents from Calendula officinalis Extracts Optimized by Response Surface Methodology

PubMed Central

Goktas, Fatih Mehmet; Sahin, Bilgesu; Yigitarslan, Sibel

2015-01-01

The aim of this study was to produce hand sterilizing liquid and wet wipes with the extracts of Calendula officinalis. Since this plant has well known antimicrobial activity due to its phytochemical constituents, the increase in the extraction yield was chosen as the principle part of the production process. To achieve the maximum yield, parameters of solid-to-liquid ratio, extraction temperature, and time were studied. The optimum conditions were determined by response surface methodology as 41°C, 7 h, and 3.3 g/200 mL for temperature, time, and solid-to-liquid ratio, respectively. The yield achieved at those conditions was found to be 90 percent. The highest amounts of flavonoids were detected at optimum, whereas the highest triterpene and saponin constituents were determined at different design points. The microbial efficiencies of extracts were determined by the inhibition of the growth of selected microorganisms. Different dilution rates and interaction times were used as parameters of inhibition. Not any of the constituent but symbiotic relation in-between reached the highest inhibition of 90 percent. The pH values of the extracts were 5.1 to 5.4. As a result, the extraction of Calendula officinalis at the optimum conditions can be used effectively in the production of wet wipes and hand sterilizing liquid. PMID:26064122

Electromembrane extraction through a virtually rotating supported liquid membrane.

PubMed

Hosseiny Davarani, Saied Saeed; Moazami, Hamid Reza; Memarian, Elham; Nojavan, Saeed

2016-01-01

Electromembrane extraction (EME) of model analytes was carried out using a virtually rotating supported liquid membrane (SLM). The virtual (nonmechanical) rotating of the SLM was achieved using a novel electrode assembly including a central electrode immersed inside the lumen of the SLM and five counter electrodes surrounding the SLM. A particular electronic circuit was designed to distribute the potential among five counter electrodes in a rotating pattern. The effect of the experimental parameters on the recovery of the extraction was investigated for verapamil (VPL), trimipramine (TRP), and clomipramine (CLP) as the model analytes and 2-ethyl hexanol as the SLM solvent. The results showed that the recovery of the extraction is a function of the angular velocity of the virtual rotation. The best results were obtained at an angular velocity of 1.83 RadS(-1) (or a rotation frequency of 0.29 Hz).The optimization of the parameters gave higher recoveries up to 50% greater than those of a conventional EME method. The rotating also allowed the extraction to be carried out at shorter time (15 min) and lower voltage (200 V) with respect to the conventional extraction. The model analytes were successfully extracted from wastewater and human urine samples with recoveries ranging from 38 to 85%. The RSD of the determinations was in the range of 12.6 to 14.8%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Response surface methodology based extraction of Tribulus terrestris leads to an upsurge of antilithiatic potential by inhibition of calcium oxalate crystallization processes.

PubMed

Kaushik, Jyoti; Tandon, Simran; Gupta, Varun; Nayyar, Jasamrit; Singla, Surinder Kumar; Tandon, Chanderdeep

2017-01-01

Tribulus terrestris has significant antilithiatic efficacy established via both in vitro as well as in vivo studies and is used in numerous anti-urolithiatic herbal formulations viz. Cystone, Uriflow, Uritone and Neeri. However, to fully utilize its antilithiatic potential, the influence of different extraction parameters on antilithiatic ability of T. terrestris aqueous extract needs elucidation. Thus, the current study was undertaken using statistically optimized extraction conditions for aqueous extract preparation. Response surface methodology was employed to observe the influence of three variables i.e. temperature (°C), time (h) and solid: liquid ratio (S: L) on the extraction yield (%) and protein content (mg/g) of T. terrestris aqueous extract. RSM results revealed that the high S:L ratio, low temperature and reduced incubation time were optimal conditions for aqueous extraction. Under such extraction conditions the protein content reached the value of 26.6±1.22 mg/g and the obtained extraction yield was 27.32±1.62%. The assessment of antilithiatic activity of 4 selected extracts (AE1-4), revealed enhanced nucleation and aggregation inhibition of calcium oxalate crystals with AE1 and AE2, which in addition significantly altered the size and morphology of calcium oxalate monohydrate (COM) crystals compared to AE3 and AE4. In vitro cell culture based studies on renal epithelial cells (MDCK, NRK-52E and PK 15) proved that the AE1 showed higher cytoprotective potency by increasing cell viability as compared to the oxalate treated group. The free radical scavenging activity of aqueous extract lowered the reactive oxygen specie's induced damage and potentially reduced the signals of programmed cell death due to oxalate injury. In addition, modulation of the COM crystal morphology was enhanced by AE1 as compared to AE2. The FTIR and GC-MS analysis of AE1, showed the presence of biomolecules which could aid in the attenuation of lithiatic process. In the light of these results the utility of the RSM approach to fully optimize the antilithiatic potential of T. terrestris cannot be undermined.

Response surface methodology based extraction of Tribulus terrestris leads to an upsurge of antilithiatic potential by inhibition of calcium oxalate crystallization processes

PubMed Central

Kaushik, Jyoti; Tandon, Simran; Gupta, Varun; Nayyar, Jasamrit; Singla, Surinder Kumar; Tandon, Chanderdeep

2017-01-01

Tribulus terrestris has significant antilithiatic efficacy established via both in vitro as well as in vivo studies and is used in numerous anti-urolithiatic herbal formulations viz. Cystone, Uriflow, Uritone and Neeri. However, to fully utilize its antilithiatic potential, the influence of different extraction parameters on antilithiatic ability of T. terrestris aqueous extract needs elucidation. Thus, the current study was undertaken using statistically optimized extraction conditions for aqueous extract preparation. Response surface methodology was employed to observe the influence of three variables i.e. temperature (°C), time (h) and solid: liquid ratio (S: L) on the extraction yield (%) and protein content (mg/g) of T. terrestris aqueous extract. RSM results revealed that the high S:L ratio, low temperature and reduced incubation time were optimal conditions for aqueous extraction. Under such extraction conditions the protein content reached the value of 26.6±1.22 mg/g and the obtained extraction yield was 27.32±1.62%. The assessment of antilithiatic activity of 4 selected extracts (AE1-4), revealed enhanced nucleation and aggregation inhibition of calcium oxalate crystals with AE1 and AE2, which in addition significantly altered the size and morphology of calcium oxalate monohydrate (COM) crystals compared to AE3 and AE4. In vitro cell culture based studies on renal epithelial cells (MDCK, NRK-52E and PK 15) proved that the AE1 showed higher cytoprotective potency by increasing cell viability as compared to the oxalate treated group. The free radical scavenging activity of aqueous extract lowered the reactive oxygen specie’s induced damage and potentially reduced the signals of programmed cell death due to oxalate injury. In addition, modulation of the COM crystal morphology was enhanced by AE1 as compared to AE2. The FTIR and GC-MS analysis of AE1, showed the presence of biomolecules which could aid in the attenuation of lithiatic process. In the light of these results the utility of the RSM approach to fully optimize the antilithiatic potential of T. terrestris cannot be undermined. PMID:28846699

The high-performance liquid chromatography/multistage electrospray mass spectrometric investigation and extraction optimization of beech (Fagus sylvatica L.) bark polyphenols.

PubMed

Hofmann, Tamás; Nebehaj, Esztella; Albert, Levente

2015-05-08

The aim of the present work was the high-performance liquid chromatographic separation and multistage mass spectrometric characterization of the polyphenolic compounds of beech bark, as well as the extraction optimization of the identified compounds. Beech is a common and widely used material in the wood industry, yet its bark is regarded as a by-product. Using appropriate extraction methods these compounds could be extracted and utilized in the future. Different extraction methods (stirring, sonication, microwave assisted extraction) using different solvents (water, methanol:water 80:20 v/v, ethanol:water 80:20 v/v) and time/temperature schedules have been compared basing on total phenol contents (Folin-Ciocâlteu) and MRM peak areas of the identified compounds to investigate optimum extraction efficiency. Altogether 37 compounds, including (+)-catechin, (-)-epicatechin, quercetin-O-hexoside, taxifolin-O-hexosides (3), taxifolin-O-pentosides (4), B-type (6) and C-type (6) procyanidins, syringic acid- and coumaric acid-di-O-glycosides, coniferyl alcohol- and sinapyl alcohol-glycosides, as well as other unknown compounds with defined [M-H](-) m/z values and MS/MS spectra have been tentatively identified. The choice of the method, solvent system and time/temperature parameters favors the extraction of different types of compounds. Pure water can extract compounds as efficiently as mixtures containing organic solvents under high-pressure and high temperature conditions. This supports the implementation of green extraction methods in the future. Extraction times that are too long and high temperatures can result in the decrease of the concentrations. Future investigations will focus on the evaluation of the antioxidant capacity and utilization possibilities of the prepared extracts. Copyright © 2015 Elsevier B.V. All rights reserved.

Hollow Fiber Supported Ionic Liquids Liquid-Phase Micro-extraction Followed by High-Performance Liquid Chromatography for the Determination of Polycyclic Aromatic Hydrocarbons in Milk Samples.

PubMed

Wang, Meng; Cheng, Chunsheng; Liu, Chunbo; Yang, Yaling

2018-01-01

A rapid, simple, reliable and efficient hollow fiber supported ionic liquids liquid-phase micro-extraction method (IL-HF-LPME) followed by high-performance liquid chromatography was successfully applied to the determination of four kinds of polycyclic aromatic hydrocarbons (PAHs) in milk samples. In the IL-HF-LPME method, a mixture of [OMIM]PF6 and lauric acid, in a ratio of 3:1, was immobilized in the pores of a polypropylene hollow fiber used as extraction solvent. A series of essential parameters influencing the extraction efficiency were investigated and optimized. Under the optimal conditions, the extraction equilibrium is achieved within 3 min, the good linearity was >0.9990, the limits of detection varied from 0.14 to 0.71 ng/mL, the limit of quantification values were between 0.4 and 1.8 ng/mL, and the relative standard deviations were in the range of 1.24-3.27% (n = 5). The proposed method was applied to analyze four PAHs in milk samples and recoveries were between 93.6 and 102.8%. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Disposable bioluminescence-based biosensor for detection of bacterial count in food.

PubMed

Luo, Jinping; Liu, Xiaohong; Tian, Qing; Yue, Weiwei; Zeng, Jing; Chen, Guangquan; Cai, Xinxia

2009-11-01

A biosensor for rapid detection of bacterial count based on adenosine 5'-triphosphate (ATP) bioluminescence has been developed. The biosensor is composed of a key sensitive element and a photomultiplier tube used as a detector element. The disposable sensitive element consists of a sampler, a cartridge where intracellular ATP is chemically extracted from bacteria, and a microtube where the extracted ATP reacts with the luciferin-luciferase reagent to produce bioluminescence. The bioluminescence signal is transformed into relevant electrical signal by the detector and further measured with a homemade luminometer. Parameters affecting the amount of the extracted ATP, including the types of ATP extractants, the concentrations of ATP extractant, and the relevant neutralizing reagent, were optimized. Under the optimal experimental conditions, the biosensor showed a linear response to standard bacteria in a concentration range from 10(3) to 10(8) colony-forming units (CFU) per milliliter with a correlation coefficient of 0.925 (n=22) within 5min. Moreover, the bacterial count of real food samples obtained by the biosensor correlated well with those by the conventional plate count method. The proposed biosensor, with characteristics of low cost, easy operation, and fast response, provides potential application to rapid evaluation of bacterial contamination in the food industry, environment monitoring, and other fields.

LC-MS metabolic profiling of Arabidopsis thaliana plant leaves and cell cultures: optimization of pre-LC-MS procedure parameters.

PubMed

t'Kindt, Ruben; De Veylder, Lieven; Storme, Michael; Deforce, Dieter; Van Bocxlaer, Jan

2008-08-01

This study treats the optimization of methods for homogenizing Arabidopsis thaliana plant leaves as well as cell cultures, and extracting their metabolites for metabolomics analysis by conventional liquid chromatography electrospray ionization mass spectrometry (LC-ESI/MS). Absolute recovery, process efficiency and procedure repeatability have been compared between different pre-LC-MS homogenization/extraction procedures through the use of samples fortified before extraction with a range of representative metabolites. Hereby, the magnitude of the matrix effect observed in the ensuing LC-MS based metabolomics analysis was evaluated. Based on relative recovery and repeatability of key metabolites, comprehensiveness of extraction (number of m/z-retention time pairs) and clean-up potential of the approach (minimum matrix effects), the most appropriate sample pre-treatment was adopted. It combines liquid nitrogen homogenization for plant leaves with thermomixer based extraction using MeOH/H(2)O 80/20. As such, an efficient and highly reproducible LC-MS plant metabolomics set-up is achieved, as illustrated by the obtained results for both LC-MS (8.88%+/-5.16 versus 7.05%+/-4.45) and technical variability (12.53%+/-11.21 versus 9.31%+/-6.65) data in a comparative investigation of A. thaliana plant leaves and cell cultures, respectively.

[Analysis of methylmercury in biological guano by the optimized atomic fluorescence spectrometry coupled with microwave assisted extraction].

PubMed

Chen, Qian-Qian; Liu, Xiao-Dong; Sun, Li-Guang; Jiang, Shan; Yan, Hong; Liu, Yi; Luo, Yu-Han; Huang, Jing

2011-01-01

The analytical method for the determination of methylmercury in seabird excrements was established using atomic fluorescence spectrometry coupled with microwave-assisted extraction In general, temperature and hydrochloric amount are the most important influencing factors on the extraction of MeHg in the samples, and the present paper optimized these two parameters. The result showed that 120 degrees C and 200 microL 6 mol x L(-1) hydrochloric acid are the best extraction conditions. Under these experimental conditions, the relative standard deviation (RSD) values of reduplicative analyses on standard reference material (human hair powder) and the same seabird excrement sample were 0.74% and 6.61% respectively, and their percent recoveries were over 90%. The combination of microwave-assisted extraction and atomic fluorescence spectrometry has many advantages such as simple operation, high sensitivity, low detection limit and low cost, therefore, it is suitable for rapid separation and analysis of trace methylmercury composition in the biological guanos. Using this method, we analyzed the methylmercury contents in the ancient and fresh seabird droppings taken from Xisha Islands of South China Sea, and the result showed that the Xisha guanos were rich in methylmercury and the large input of seabird guanos will cause serious environmental contamination in the remote island ecosystem of Xisha Islands.

Preparation of l-phenylalanine-imprinted solid-phase extraction sorbent by Pickering emulsion polymerization and the selective enrichment of l-phenylalanine from human urine.

PubMed

Li, Ji; Hu, Xiaoling; Guan, Ping; Zhang, Xiaoyan; Qian, Liwei; Zhang, Nan; Du, Chunbao; Song, Renyuan

2016-05-01

A novel l-phenylalanine molecularly imprinted solid-phase extraction sorbent was synthesized by the combination of Pickering emulsion polymerization and ion-pair dummy template imprinting. Compared to other polymerization methods, the molecularly imprinted polymers thus prepared exhibit a high specific surface, large pore diameter, and appropriate particle size. The key parameters for solid-phase extraction were optimized, and the result indicated that the molecularly imprinted polymer thus prepared exhibits a good recovery of 98.9% for l-phenylalanine. Under the optimized conditions of the procedure, an analytical method for l-phenylalanine was well established. By comparing the performance of the molecularly imprinted polymer and a commercial reverse-phase silica gel, the obtained molecularly imprinted polymer as an solid-phase extraction sorbent is more suitable, exhibiting high precision (relative standard deviation 3.2%, n = 4) and a low limit of detection (60.0 ± 1.9 nmol·L(-1) ) for the isolation of l-phenylalanine. Based on these results, the combination of the Pickering emulsion polymerization and ion-pair dummy template imprinting is effective for preparing selective solid-phase extraction sorbents for the separation of amino acids and organic acids from complex biological samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Model Parameter Extraction Method for Dielectric Barrier Discharge Ozone Chamber using Differential Evolution

NASA Astrophysics Data System (ADS)

Amjad, M.; Salam, Z.; Ishaque, K.

2014-04-01

In order to design an efficient resonant power supply for ozone gas generator, it is necessary to accurately determine the parameters of the ozone chamber. In the conventional method, the information from Lissajous plot is used to estimate the values of these parameters. However, the experimental setup for this purpose can only predict the parameters at one operating frequency and there is no guarantee that it results in the highest ozone gas yield. This paper proposes a new approach to determine the parameters using a search and optimization technique known as Differential Evolution (DE). The desired objective function of DE is set at the resonance condition and the chamber parameter values can be searched regardless of experimental constraints. The chamber parameters obtained from the DE technique are validated by experiment.

Optimization of LC-Orbitrap-HRMS acquisition and MZmine 2 data processing for nontarget screening of environmental samples using design of experiments.

PubMed

Hu, Meng; Krauss, Martin; Brack, Werner; Schulze, Tobias

2016-11-01

Liquid chromatography-high resolution mass spectrometry (LC-HRMS) is a well-established technique for nontarget screening of contaminants in complex environmental samples. Automatic peak detection is essential, but its performance has only rarely been assessed and optimized so far. With the aim to fill this gap, we used pristine water extracts spiked with 78 contaminants as a test case to evaluate and optimize chromatogram and spectral data processing. To assess whether data acquisition strategies have a significant impact on peak detection, three values of MS cycle time (CT) of an LTQ Orbitrap instrument were tested. Furthermore, the key parameter settings of the data processing software MZmine 2 were optimized to detect the maximum number of target peaks from the samples by the design of experiments (DoE) approach and compared to a manual evaluation. The results indicate that short CT significantly improves the quality of automatic peak detection, which means that full scan acquisition without additional MS 2 experiments is suggested for nontarget screening. MZmine 2 detected 75-100 % of the peaks compared to manual peak detection at an intensity level of 10 5 in a validation dataset on both spiked and real water samples under optimal parameter settings. Finally, we provide an optimization workflow of MZmine 2 for LC-HRMS data processing that is applicable for environmental samples for nontarget screening. The results also show that the DoE approach is useful and effort-saving for optimizing data processing parameters. Graphical Abstract ᅟ.

Power maximization of a point absorber wave energy converter using improved model predictive control

NASA Astrophysics Data System (ADS)

Milani, Farideh; Moghaddam, Reihaneh Kardehi

2017-08-01

This paper considers controlling and maximizing the absorbed power of wave energy converters for irregular waves. With respect to physical constraints of the system, a model predictive control is applied. Irregular waves' behavior is predicted by Kalman filter method. Owing to the great influence of controller parameters on the absorbed power, these parameters are optimized by imperialist competitive algorithm. The results illustrate the method's efficiency in maximizing the extracted power in the presence of unknown excitation force which should be predicted by Kalman filter.

Efficacy of standardized extract of Hibiscus sabdariffa L. (Malvaceae) in improving iron status of adults in malaria endemic area: A randomized controlled trial.

PubMed

Peter, Emanuel L; Rumisha, Susan F; Mashoto, Kijakazi O; Minzi, Omary Ms; Mfinanga, Sayoki

2017-09-14

Indigenous community of Mkuranga district have been using aqueous extract of H. sabdariffa L. for treating anemia. However, there have been neither safety nor efficacy studies to validate this medicinal product in anemia. The purpose of this study was to establish efficacy and safety of standardized aqueous extract of H. sabdariffa L. in anemic adults. This was a randomized controlled clinical trial in which 130 adults' men and women aged 18-50 years were involved after meeting the inclusion criteria. Initially, standardized aqueous extract of H. sabdariffa L. was prepared using optimized extraction parameters. Stratified randomization was used to randomize participants into four fixed dose groups. The first group received oral dose of 1000ml while the 2nd group was randomized to receive 1500ml orally. The last two groups were given a dose of 2000ml of extract and 200mg ferrous sulphate tablet respectively. Primary endpoint was the actual change of iron status indicators at the end of 30 days follow up period as compared to those recorded at baseline. Adverse effects were assessed at every 10th day scheduled visit. In all arms, HB and hematopoietic parameters were measured using HemoCue hemoglobinometer® (HemoCue, Ängelholm, Sweden) and hematology analyzer® respectively at the trial site. Follow up was done for 30 days. A total of 82 participants were included for analysis. A standardized aqueous extract of H. sabdariffa L. did not improve iron status in anemic adults in malaria endemic region (P>0.005). However, there was evidence to support the safety of the extract for human consumptions as herbal supplement. Iron and organic acids contents of H. sabdariffa L. extract showed the potential of improving hematopoietic parameters. Studies with bigger sample size are therefore needed to establish the efficacy of the extract when concurrently used with malaria chemoprophylaxis in malaria endemic areas. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Rapid Determination of Clenbuterol in Pork by Direct Immersion Solid-Phase Microextraction Coupled with Gas Chromatography-Mass Spectrometry.

PubMed

Ye, Diru; Wu, Susu; Xu, Jianqiao; Jiang, Ruifen; Zhu, Fang; Ouyang, Gangfeng

2016-02-01

Direct immersion solid-phase microextraction (DI-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was developed for rapid analysis of clenbuterol in pork for the first time. In this work, a low-cost homemade 44 µm polydimethylsiloxane (PDMS) SPME fiber was employed to extract clenbuterol in pork. After extraction, derivatization was performed by suspending the fiber in the headspace of the 2 mL sample vial saturated with a vapor of 100 µL hexamethyldisilazane. Lastly, the fiber was directly introduced to GC-MS for analysis. All parameters that influenced absorption (extraction time), derivatization (derivatization reagent, time and temperature) and desorption (desorption time) were optimized. Under optimized conditions, the method offered a wide linear range (10-1000 ng g(-1)) and a low detection limit (3.6 ng g(-1)). Finally, the method was successfully applied in the analysis of pork from the market, and recoveries of the method for spiked pork were 97.4-105.7%. Compared with the traditional solvent extraction method, the proposed method was much cheaper and fast. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Chemically modified cellulose paper as a thin film microextraction phase.

PubMed

Saraji, Mohammad; Farajmand, Bahman

2013-11-01

In this paper, chemically modified cellulose paper was introduced as a novel extracting phase for thin film microextraction (TFME). Different reagents (Octadecyltrichlorosilane, diphenyldichlorosilane, cyclohexyl isocyanate and phenyl isocyanate) were used to modify the cellulose papers. The modified papers were evaluated as a sorbent for the extraction of some synthetic and natural estrogenic hormones (17α-ethynylestradiol, estriol and estradiol) from aqueous samples. Liquid chromatography-fluorescence detection was used for the quantification of the extracted compounds. The cellulose paper modified with phenyl isocyanate showed the best affinity to the target compounds. TEME parameters such as desorption condition, shaking rate, sample ionic strength and extraction time were investigated and optimized. Limit of detections were between 0.05 and 0.23μgL(-1) and relative standard deviations were less than 11.1% under the optimized condition. The calibration curves were obtained in the range of 0.2-100μgL(-1) with a good linearity (r(2)>0.9935). Wastewater, human urine, pool and river water samples were studied as real samples for the evaluation of the method. Relative recoveries were found to be between 75% and 101%. Copyright © 2013 Elsevier B.V. All rights reserved.

Fast automated dual-syringe based dispersive liquid-liquid microextraction coupled with gas chromatography-mass spectrometry for the determination of polycyclic aromatic hydrocarbons in environmental water samples.

PubMed

Guo, Liang; Tan, Shufang; Li, Xiao; Lee, Hian Kee

2016-03-18

An automated procedure, combining low density solvent based solvent demulsification dispersive liquid-liquid microextraction (DLLME) with gas chromatography-mass spectrometry analysis, was developed for the determination of polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. Capitalizing on a two-rail commercial autosampler, fast solvent transfer using a large volume syringe dedicated to the DLLME process, and convenient extract collection using a small volume microsyringe for better GC performance were enabled. Extraction parameters including the type and volume of extraction solvent, the type and volume of dispersive solvent and demulsification solvent, extraction and demulsification time, and the speed of solvent injection were investigated and optimized. Under the optimized conditions, the linearity ranged from 0.1 to 50 μg/L, 0.2 to 50 μg/L, and 0.5 to 50 μg/L, depending on the analytes. Limits of detection were determined to be between 0.023 and 0.058 μg/L. The method was applied to determine PAHs in environmental water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Capacitive Energy Extraction by Few-Layer Graphene Electrodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lian, Cheng; Zhan, Cheng; Jiang, De-en

Capacitive double-layer expansion is a promising technology to harvest energy arising from the salinity difference between freshwater and seawater. Its optimal performance requires a careful selection of the operation potentials and electrode materials. While carbonaceous materials such as graphene and various forms of activated carbons are routinely used as the electrodes, there is little knowledge on how the quantum capacitance and the electric double-layer (EDL) capacitance, which are on the same order of magnitude, affect the capacitive performance. Toward understanding that from a theoretical perspective, here we study the capacitive energy extraction with graphene electrodes as a function of themore » number of graphene layers. The classical density functional theory is joined with the electronic density functional theory to obtain the EDL and the quantum capacitance, respectively. The theoretical results show that the quantum capacitance contribution plays a dominant role in extracting energy using the single-layer graphene, but its effect diminishes as the number of graphene layers increases. The overall extracted energy is dominated by the EDL contribution beyond about four graphene layers. Electrodes with more graphene layers are able to extract more energy at low charging potential. Here, because many porous carbons have nanopores with stacked graphene layers, our theoretical predictions are useful to identify optimal operation parameters for capacitive energy extraction with porous electrodes of different wall thickness.« less

Capacitive Energy Extraction by Few-Layer Graphene Electrodes

DOE PAGES

Lian, Cheng; Zhan, Cheng; Jiang, De-en; ...

2017-06-09

Capacitive double-layer expansion is a promising technology to harvest energy arising from the salinity difference between freshwater and seawater. Its optimal performance requires a careful selection of the operation potentials and electrode materials. While carbonaceous materials such as graphene and various forms of activated carbons are routinely used as the electrodes, there is little knowledge on how the quantum capacitance and the electric double-layer (EDL) capacitance, which are on the same order of magnitude, affect the capacitive performance. Toward understanding that from a theoretical perspective, here we study the capacitive energy extraction with graphene electrodes as a function of themore » number of graphene layers. The classical density functional theory is joined with the electronic density functional theory to obtain the EDL and the quantum capacitance, respectively. The theoretical results show that the quantum capacitance contribution plays a dominant role in extracting energy using the single-layer graphene, but its effect diminishes as the number of graphene layers increases. The overall extracted energy is dominated by the EDL contribution beyond about four graphene layers. Electrodes with more graphene layers are able to extract more energy at low charging potential. Here, because many porous carbons have nanopores with stacked graphene layers, our theoretical predictions are useful to identify optimal operation parameters for capacitive energy extraction with porous electrodes of different wall thickness.« less

[Studying on purification technology of Resina Draconis phenol extracts based on design space method].

PubMed

Zhang, Jian; Zhang, Xin; Bi, Yu-An; Xu, Gui-Hong; Huang, Wen-Zhe; Wang, Zhen-Zhong; Xiao, Wei

2017-09-01

The "design space" method was used to optimize the purification process of Resina Draconis phenol extracts by using the concept of "quality derived from design" (QbD). The content and transfer rate of laurin B and 7,4'-dihydroxyflavone and yield of extract were selected as the critical quality attributes (CQA). Plackett-Burman design showed that the critical process parameters (CPP) were concentration of alkali, the amount of alkali and the temperature of alkali dissolution. Then the Box-Behnken design was used to establish the mathematical model between CQA and CPP. The variance analysis results showed that the P values of the five models were less than 0.05 and the mismatch values were all greater than 0.05, indicating that the model could well describe the relationship between CQA and CPP. Finally, the control limits of the above 5 indicators (content and transfer rate of laurine B and 7,4'-dihydroxyflavone, as well as the extract yield) were set, and then the probability-based design space was calculated by Monte Carlo simulation and verified. The results of the design space validation showed that the optimized purification method can ensure the stability of the Resina Draconis phenol extracts refining process, which would help to improve the quality uniformity between batches of phenol extracts and provide data support for production automation control. Copyright© by the Chinese Pharmaceutical Association.

Development of a dispersive liquid-liquid microextraction method using a lighter-than-water ionic liquid for the analysis of polycyclic aromatic hydrocarbons in water.

PubMed

Medina, Giselle S; Reta, Mario

2016-11-01

A dispersive liquid-liquid microextraction method using a lighter-than-water phosphonium-based ionic liquid for the extraction of 16 polycyclic aromatic hydrocarbons from water samples has been developed. The extracted compounds were analyzed by liquid chromatography coupled to fluorescence/diode array detectors. The effects of several experimental parameters on the extraction efficiency, such as type and volume of ionic liquid and disperser solvent, type and concentration of salt in the aqueous phase and extraction time, were investigated and optimized. Three phosphonium-based ionic liquids were assayed, obtaining larger extraction efficiencies when trihexyl-(tetradecyl)phosphonium bromide was used. The optimized methodology requires a few microliters of a lighter-than-water phosphonium-based ionic liquid, which allows an easy separation of the extraction solvent phase. The obtained limits of detection were between 0.02 and 0.56 μg/L, enrichment factors between 109 and 228, recoveries between 60 and 108%, trueness between 0.4 and 9.9% and reproducibility values between 3 and 12% were obtained. These figures of merit combined with the simplicity, rapidity and low cost of the analytical methodology indicate that this is a viable and convenient alternative to the methods reported in the literature. The developed method was used to analyze polycyclic aromatic hydrocarbons in river water samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microwave assisted solid phase extraction for separation preconcentration sulfamethoxazole in wastewater using tyre based activated carbon as solid phase material prior to spectrophotometric determination.

PubMed

Mogolodi Dimpe, K; Mpupa, Anele; Nomngongo, Philiswa N

2018-01-05

This work was chiefly encouraged by the continuous consumption of antibiotics which eventually pose harmful effects on animals and human beings when present in water systems. In this study, the activated carbon (AC) was used as a solid phase material for the removal of sulfamethoxazole (SMX) in wastewater samples. The microwave assisted solid phase extraction (MASPE) as a sample extraction method was employed to better extract SMX in water samples and finally the analysis of SMX was done by the UV-Vis spectrophotometer. The microwave assisted solid phase extraction method was optimized using a two-level fractional factorial design by evaluating parameters such as pH, mass of adsorbent (MA), extraction time (ET), eluent ratio (ER) and microwave power (MP). Under optimized conditions, the limit of detection (LOD) and limit of quantification (LOQ) were 0.5μgL -1 and 1.7μgL -1 , respectively, and intraday and interday precision expressed in terms of relative standard deviation were >6%.The maximum adsorption capacity was 138mgg -1 for SMX and the adsorbent could be reused eight times. Lastly, the MASPE method was applied for the removal of SMX in wastewater samples collected from a domestic wastewater treatment plant (WWTP) and river water. Copyright © 2017 Elsevier B.V. All rights reserved.

Optimization of rotor shaft shrink fit method for motor using "Robust design"

NASA Astrophysics Data System (ADS)

Toma, Eiji

2018-01-01

This research is collaborative investigation with the general-purpose motor manufacturer. To review construction method in production process, we applied the parameter design method of quality engineering and tried to approach the optimization of construction method. Conventionally, press-fitting method has been adopted in process of fitting rotor core and shaft which is main component of motor, but quality defects such as core shaft deflection occurred at the time of press fitting. In this research, as a result of optimization design of "shrink fitting method by high-frequency induction heating" devised as a new construction method, its construction method was feasible, and it was possible to extract the optimum processing condition.

Ultrahigh pressure extraction of lignan compounds from Dysosma versipellis and purification by high-speed counter-current chromatography.

PubMed

Zhu, Qing; Liu, Feng; Xu, Meixia; Lin, Xiaojing; Wang, Xiao

2012-09-15

Ultrahigh pressure extraction (UPE) was employed to extract podophyllotoxin and 4'-demethylpodophyllotoxin from Dysosma versipellis. The effects of extraction parameters including extraction solvents, pressure, time and solid/liquid ratio were investigated using a High Hydrostatic Pressure Processor. The optimal condition for UPE of the target compounds was 80% methanol, 200 MPa of pressure, 1 min of extraction time and 1:12 (g/mL) of solid/liquid ratio. Podophyllotoxin and 4'-demethylpodophyllotoxin in the crude extract were purified by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water (10:10:8:12, v/v), and the fractions were analyzed by HPLC, ESI-MS and (1)H NMR. As a result, 73.7 mg podophyllotoxin and 16.5mg 4'-demethylpodophyllotoxin with purities over 96% were obtained from 260 mg crude sample in one-step separation. Copyright © 2012 Elsevier B.V. All rights reserved.

Dynamic microwave assisted extraction coupled with dispersive micro-solid-phase extraction of herbicides in soybeans.

PubMed

Li, Na; Wu, Lijie; Nian, Li; Song, Ying; Lei, Lei; Yang, Xiao; Wang, Kun; Wang, Zhibing; Zhang, Liyuan; Zhang, Hanqi; Yu, Aimin; Zhang, Ziwei

2015-09-01

Non-polar solvent dynamic microwave assisted extraction was firstly applied to the treatment of high-fat soybean samples. In the dispersive micro-solid-phase extraction (D-µ-SPE), the herbicides in the high-fat extract were directly adsorbed on metal-organic frameworks MIL-101(Cr). The effects of several experimental parameters, including extraction solvent, microwave absorption medium, microwave power, volume and flow rate of extraction solvent, amount of MIL-101(Cr), and D-µ-SPE time, were investigated. At the optimal conditions, the limits of detection for the herbicides ranged from 1.56 to 2.00 μg kg(-1). The relative recoveries of the herbicides were in the range of 91.1-106.7%, and relative standard deviations were equal to or lower than 6.7%. The present method was simple, rapid and effective. A large amount of fat was also removed. This method was demonstrated to be suitable for treatment of high-fat samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Chemical and biological evaluation of Ranunculus muricatus.

PubMed

Khan, Farhat Ali; Zahoor, Muhammad; Khan, Ezzat

2016-03-01

Ranunculus muricatus is commonly known as spiny fruit buttercup and is used in the treatment of intermittent fevers, gout and asthma. Qualitative analysis of phytochemicals of Ranunculus muricatus indicated the presence of saponins, tannins, phenols, flavonoids and alkaloids. Saponins were present in high amount as compared with other chemicals. Inorganic and heavy metals constituents were determined. Heavy metals estimation in the sample showed that iron was present in high amount followed by zinc even then the concentration of these metals is below acceptable limit. The physical parameters, antioxidant and antimicrobial activities of the extracts were determined. Acetone extract fraction showed optimal antioxidant activity as compared to ethanol and chloroform fractions of the candidate plant. The antimicrobial and antifungal activities of the crude extract and extract fractions were determined by well agar diffusion method. Highest zone of inhibitions were observed for crude extract followed by acetone extract fraction against Micrococcus luteus. Antifungal activities were high for crude extracts against Candida Albican. Findings of this study show that Ranunculus muricatus has a good medicinal impact.

A green deep eutectic solvent dispersive liquid-liquid micro-extraction (DES-DLLME) for the UHPLC-PDA determination of oxyprenylated phenylpropanoids in olive, soy, peanuts, corn, and sunflower oil.

PubMed

Ferrone, Vincenzo; Genovese, Salvatore; Carlucci, Maura; Tiecco, Matteo; Germani, Raimondo; Preziuso, Francesca; Epifano, Francesco; Carlucci, Giuseppe; Taddeo, Vito Alessandro

2018-04-15

A green dispersive liquid-liquid microextraction (DLLME) using deep eutectic solvent (DES) as the extracting solvent has been developed and applied for the simultaneous quantification of ferulic acid, umbelliferone, boropinic acid, 7-isopentenyloxycoumarin, 4'-geranyloxyferulic acid (GOFA), and auraptene in some vegetable oils using ultra high performance liquid chromatography (UHPLC) with photodiode array detection (PDA). All parameters in the extraction step, including selection and loading of both extracting and dispersing solvents, amount of both extractant and disperser solvent were investigated and optimized. PhAA/TMG DES achieved higher recovery and enrichment factor compared to other DESs. The validated method showed good linearity with correlation coefficients, r 2 >0.9990 for all the analytes. Furthermore, this is the first time that eco-friendly solvents are used for the extraction of oxyprenylated phenylpropanoids and the corresponding extract analyzed with ultra high performance liquid chromatography with photodiode array detection. Copyright © 2017 Elsevier Ltd. All rights reserved.

"Solvent-free" ultrasound-assisted extraction of lipids from fresh microalgae cells: a green, clean and scalable process.

PubMed

Adam, Fanny; Abert-Vian, Maryline; Peltier, Gilles; Chemat, Farid

2012-06-01

In order to comply with criteria of green chemistry concepts and sustainability, a new procedure has been performed for solvent-free ultrasound-assisted extraction (UAE) to extract lipids from fresh Nannochloropsis oculata biomass. Through response surface methodology (RSM) parameters affecting the oil recovery were optimized. Optimum conditions for oil extraction were estimated as follows: (i) 1000 W ultrasonic power, (ii) 30 min extraction time and (iii) biomass dry weight content at 5%. Yields were calculated by the total fatty acids methyl esters amounts analyzed by GC-FID-MS. The maximum oil recovery was around 0.21%. This value was compared with the one obtained with the conventional extraction method (Bligh and Dyer). Furthermore, effect of temperature on the yield was also investigated. The overall results show an innovative and effective extraction method adapted for microalgae oil recovery, without using solvent and with an enable scaling up. Copyright © 2012 Elsevier Ltd. All rights reserved.

Characterization of odor-active volatiles in apples: influence of cultivars and maturity stage.

PubMed

Mehinagic, Emira; Royer, Gaëlle; Symoneaux, Ronan; Jourjon, Frédérique; Prost, Carole

2006-04-05

The aroma and texture of three different apple cultivars, harvested at three maturity stages, were analyzed by sensory and instrumental analysis. The emphasis was on the identification of the most potent odorant volatiles, and the challenge was to separate the few most important flavor compounds, which may be trace chemicals, from the vast number of nonodorant compounds present in apple aroma extracts. Thirty-six odorant compounds were detected, 24 of which were common to all extracts. A significant correlation coefficient was found between the aroma intensity scores and overall quantity of the odorant volatiles, which shows that the development of sensory aroma is similar to that of odorant volatiles. This study also showed that the parameters measured by penetrometry and compression were highly correlated with sensory textural attributes. The determination of the optimal maturity stage for different apple cultivars by the usual parameters, such as color, diameter, total soluble solids, and titrable acidity, may not be sufficient to determine the optimal sensory quality for consumers. Moreover, the sensory quality of fruits changes during maturation in a different way from one cultivar to another, and this should be taken into account.

A novel approach to bar adsorptive microextraction: Cork as extractor phase for determination of benzophenone, triclocarban and parabens in aqueous samples.

PubMed

Dias, Adriana Neves; da Silva, Ana Cristine; Simão, Vanessa; Merib, Josias; Carasek, Eduardo

2015-08-12

This study describes the use of cork as a new coating for bar adsorptive microextraction (BAμE) and its application in determining benzophenone, triclocarban and parabens in aqueous samples by HPLC-DAD. In this study bars with 7.5 and 15 mm of length were used. The extraction and liquid desorption steps for BAμE were optimized employing multivariate and univariate procedures. The desorption time and solvent used for liquid desorption were optimized by univariate and multivariate studies, respectively. For the extraction step the sample pH was optimized by univariate experiments while the parameters extraction time and ionic strength were evaluated using the Doehlert design. The optimum extraction conditions were sample pH 5.5, NaCl concentration 25% and extraction time 90 min. Liquid desorption was carried out for 30 min with 250 μL (bar length of 15 mm) or 100 μL (bar length of 7.5 mm) of ACN:MeOH (50:50, v/v). The quantification limits varied between 1.6 and 20 μg L(-1) (bar length of 15 mm) and 0.64 and 8 μg L(-1) (bar length of 7.5 mm). The linear correlation coefficients were higher than 0.98 for both bars. The method with 7.5 mm bar length showed recovery values between 65 and 123%. The bar-to-bar reproducibility and the repeatability were lower than 13% (n = 2) and 14% (n = 3), respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

Optimized ultrasound-assisted emulsification microextraction for simultaneous trace multielement determination of heavy metals in real water samples by ICP-OES.

PubMed

Sereshti, Hassan; Heravi, Yeganeh Entezari; Samadi, Soheila

2012-08-15

Ultrasonic-assisted emulsification microextraction (USAEME) combined with inductively coupled plasma-optical emission spectrometry (ICP-OES) was used for preconcentration and determination of aluminum, bismuth, cadmium, cobalt, copper, iron, gallium, indium, nickel, lead, thallium and zinc in real water samples. Ammonium pyrrolidine dithiocarbamate (APDC) and carbon tetrachloride (CCl(4)) were used as the chelating agent and extraction solvent, respectively. The effective parameters (factors) of the extraction process such as volume of extraction solvent, pH, sonication time, and concentration of chelating agent were optimized by a small central composite design (CCD). The optimum conditions were found to be 98 μL for extraction solvent, 1476 mg L(-1) for chelating agent, 3.8 for pH and 9 min for sonication time. Under the optimal conditions, the limits of detection (LODs) for Al, Bi, Cd, Co, Cu, Fe, Ga, In, Ni, Pb, Tl and Zn were 0.13, 0.48, 0.19, 0.28, 0.29, 0.27, 0.27, 0.38, 0.44, 0.47, 0.52 and 0.17 μg L(-1), respectively. The linear dynamic range (LDR) was 1-1000 μ gL(-1) with determination coefficients of 0.991-0.998. Relative standard deviations (RSDs, C=200 μg L(-1), n=6) were between 1.87%-5.65%. The proposed method was successfully applied to the extraction and determination of heavy metals in real water samples and the satisfactory relative recoveries (90.3%-105.5%) were obtained. Copyright © 2012 Elsevier B.V. All rights reserved.

Optimization of the Ethanol Recycling Reflux Extraction Process for Saponins Using a Design Space Approach

PubMed Central

Gong, Xingchu; Zhang, Ying; Pan, Jianyang; Qu, Haibin

2014-01-01

A solvent recycling reflux extraction process for Panax notoginseng was optimized using a design space approach to improve the batch-to-batch consistency of the extract. Saponin yields, total saponin purity, and pigment yield were defined as the process critical quality attributes (CQAs). Ethanol content, extraction time, and the ratio of the recycling ethanol flow rate and initial solvent volume in the extraction tank (RES) were identified as the critical process parameters (CPPs) via quantitative risk assessment. Box-Behnken design experiments were performed. Quadratic models between CPPs and process CQAs were developed, with determination coefficients higher than 0.88. As the ethanol concentration decreases, saponin yields first increase and then decrease. A longer extraction time leads to higher yields of the ginsenosides Rb1 and Rd. The total saponin purity increases as the ethanol concentration increases. The pigment yield increases as the ethanol concentration decreases or extraction time increases. The design space was calculated using a Monte-Carlo simulation method with an acceptable probability of 0.90. Normal operation ranges to attain process CQA criteria with a probability of more than 0.914 are recommended as follows: ethanol content of 79–82%, extraction time of 6.1–7.1 h, and RES of 0.039–0.040 min−1. Most of the results of the verification experiments agreed well with the predictions. The verification experiment results showed that the selection of proper operating ethanol content, extraction time, and RES within the design space can ensure that the CQA criteria are met. PMID:25470598

Supercritical carbon dioxide extraction of compounds with antimicrobial activity from Origanum vulgare L.: determination of optimal extraction parameters.

PubMed

Santoyo, S; Cavero, S; Jaime, L; Ibañez, E; Señoráns, F J; Reglero, G

2006-02-01

Oregano leaves were extracted using a pilot-scale supercritical fluid extraction plant under a wide range of extraction conditions, with the goal of determining the extraction and fractionation conditions to obtain extracts with optimal antimicrobial activity. In this investigation, the essential oil-rich fractions were selectively precipitated in the second separator, and their chemical composition and antimicrobial activity were investigated. Gas chromatography-mass spectrometry analysis of the various fractions resulted in the identification of 27 compounds of the essential oil. The main components of these fractions were carvacrol, trans-sabinene hydrate, cis-piperitol, borneol, terpinen-4-ol, and linalool. Antimicrobial activity was investigated by the disk diffusion and broth dilution methods against six different microbial species, including two gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), two gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), a yeast (Candida albicans), and a fungus (Aspergillus niger). All of the supercritical fluid extraction fractions obtained showed antimicrobial activity against all of the microorganisms tested, although the most active fraction was the one obtained in experiment 5 (fraction was obtained with 7% ethanol at 150 bar and 40 degrees C). C. albicans was the most sensitive microorganism to the oregano extracts, whereas the least susceptible was A. niger. Carvacrol, sabinene hydrate, borneol, and linalool standards also showed antimicrobial activity against all of the microorganisms tested, with carvacrol being the most effective. Consequently, it was confirmed that essential oil from experiment 5, with the best antimicrobial activity, also presented the highest quantity of carvacrol.

Noninvasive extraction of fetal electrocardiogram based on Support Vector Machine

NASA Astrophysics Data System (ADS)

Fu, Yumei; Xiang, Shihan; Chen, Tianyi; Zhou, Ping; Huang, Weiyan

2015-10-01

The fetal electrocardiogram (FECG) signal has important clinical value for diagnosing the fetal heart diseases and choosing suitable therapeutics schemes to doctors. So, the noninvasive extraction of FECG from electrocardiogram (ECG) signals becomes a hot research point. A new method, the Support Vector Machine (SVM) is utilized for the extraction of FECG with limited size of data. Firstly, the theory of the SVM and the principle of the extraction based on the SVM are studied. Secondly, the transformation of maternal electrocardiogram (MECG) component in abdominal composite signal is verified to be nonlinear and fitted with the SVM. Then, the SVM is trained, and the training results are compared with the real data to ensure the effect of the training. Meanwhile, the parameters of the SVM are optimized to achieve the best performance so that the learning machine can be utilized to fit the unknown samples. Finally, the FECG is extracted by removing the optimal estimation of MECG component from the abdominal composite signal. In order to evaluate the performance of FECG extraction based on the SVM, the Signal-to-Noise Ratio (SNR) and the visual test are used. The experimental results show that the FECG with good quality can be extracted, its SNR ratio is significantly increased as high as 9.2349 dB and the time cost is significantly decreased as short as 0.802 seconds. Compared with the traditional method, the noninvasive extraction method based on the SVM has a simple realization, the shorter treatment time and the better extraction quality under the same conditions.

Parameters optimization of supercritical fluid-CO2 extracts of frankincense using response surface methodology and its pharmacodynamics effects.

PubMed

Zhou, Jing; Ma, Xing-miao; Qiu, Bi-Han; Chen, Jun-xia; Bian, Lin; Pan, Lin-mei

2013-01-01

The volatile oil parts of frankincense (Boswellia carterii Birdw.) were extracted with supercritical carbon dioxide under constant pressure (15, 20, or 25 MPa) and fixed temperature (40, 50, or 60°C), given time (60, 90, or 120 min) aiming at the acquisition of enriched fractions containing octyl acetate, compounds of pharmaceutical interest. A mathematical model was created by Box-Behnken design, a popular template for response surface methodology, for the extraction process. The response value was characterized by synthetical score, which comprised yields accounting for 20% and content of octyl acetate for 80%. The content of octyl acetate was determined by GC. The supercritical fluid extraction showed higher selectivity than conventional steam distillation. Supercritical fluid-CO(2) for extracting frankincense under optimum condition was of great validity, which was also successfully verified by the pharmacological experiments. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of Method-Specific Extraction Variability for the Measurement of Fatty Acids in a Candidate Infant/Adult Nutritional Formula Reference Material.

PubMed

Place, Benjamin J

2017-05-01

To address community needs, the National Institute of Standards and Technology has developed a candidate Standard Reference Material (SRM) for infant/adult nutritional formula based on milk and whey protein concentrates with isolated soy protein called SRM 1869 Infant/Adult Nutritional Formula. One major component of this candidate SRM is the fatty acid content. In this study, multiple extraction techniques were evaluated to quantify the fatty acids in this new material. Extraction methods that were based on lipid extraction followed by transesterification resulted in lower mass fraction values for all fatty acids than the values measured by methods utilizing in situ transesterification followed by fatty acid methyl ester extraction (ISTE). An ISTE method, based on the identified optimal parameters, was used to determine the fatty acid content of the new infant/adult nutritional formula reference material.

Uncertainties in extracted parameters of a Gaussian emission line profile with continuum background.

PubMed

Minin, Serge; Kamalabadi, Farzad

2009-12-20

We derive analytical equations for uncertainties in parameters extracted by nonlinear least-squares fitting of a Gaussian emission function with an unknown continuum background component in the presence of additive white Gaussian noise. The derivation is based on the inversion of the full curvature matrix (equivalent to Fisher information matrix) of the least-squares error, chi(2), in a four-variable fitting parameter space. The derived uncertainty formulas (equivalent to Cramer-Rao error bounds) are found to be in good agreement with the numerically computed uncertainties from a large ensemble of simulated measurements. The derived formulas can be used for estimating minimum achievable errors for a given signal-to-noise ratio and for investigating some aspects of measurement setup trade-offs and optimization. While the intended application is Fabry-Perot spectroscopy for wind and temperature measurements in the upper atmosphere, the derivation is generic and applicable to other spectroscopy problems with a Gaussian line shape.

Parameters of Transportation of Tailings of Metals Lixiviating

NASA Astrophysics Data System (ADS)

Golik, Vladimir; Dmitrak, Yury

2017-11-01

The article shows that the change in the situation in the metals market with a steady increase in production volumes is intensified against the tendency of the transition of mining production from underground mining to underground mining for a certain group of ores. The possibility of a non-waste metals extraction from not only standard, but also from substandard raw materials, is currently provided only by technology with the lixiviating of metals from developing ores. The regular dependences of the magnitude of hydraulic resistances on the hydro-mixture velocity and its density are determined. The correct values of the experimental data convergence with the calculated values of these parameters are obtained. It is shown that the optimization of the transportation parameters of lixiviating tailings allows reducing the level of chemically dangerous pollution of the environment by leachate products. The direction of obtaining the ecological and technological effect from the use of simultaneously environmental and resource-saving technology for the extraction of the disclosed metals is indicated.

Heart Sound Biometric System Based on Marginal Spectrum Analysis

PubMed Central

Zhao, Zhidong; Shen, Qinqin; Ren, Fangqin

2013-01-01

This work presents a heart sound biometric system based on marginal spectrum analysis, which is a new feature extraction technique for identification purposes. This heart sound identification system is comprised of signal acquisition, pre-processing, feature extraction, training, and identification. Experiments on the selection of the optimal values for the system parameters are conducted. The results indicate that the new spectrum coefficients result in a significant increase in the recognition rate of 94.40% compared with that of the traditional Fourier spectrum (84.32%) based on a database of 280 heart sounds from 40 participants. PMID:23429515

Application of Taguchi optimisation of electro metal - electro winning (EMEW) for nickel metal from laterite

NASA Astrophysics Data System (ADS)

Sudibyo, Hermida, L.; Junaedi, A.; Putra, F. A.

2017-11-01

Nickel and cobalt metal able to process from low grade laterite using solvent extraction and electrowinning. One of electrowinning methods which has good performance to produce pure metal is electrometal-electrowinninge(EMEW). In this work, solventextraction was used to separate nickel and cobalt which useCyanex-Versatic Acid in toluene as an organic phase. An aqueous phase of extraction was processed using EMEW in order to deposit the nickel metal in Cathode electrode. The parameters which used in this work were batch temperature, operation time, voltage, and boric acid concentration. Those parameters were studied and optimized using the design of experiment of Taguchi. The Taguchi analysis result shows that the optimum result of EMEW was at 60°C of batch temperature, 2 Voltage, 6 hours operation and 0.5 M of boric acid.

Removal of toxic metals from vanadium-contaminated soils using a washing method: Reagent selection and parameter optimization.

PubMed

Jiang, Jianguo; Yang, Meng; Gao, Yuchen; Wang, Jiaming; Li, Dean; Li, Tianran

2017-08-01

Vanadium (V) contamination in soils is an increasing worldwide concern facing human health and environmental conservation. The fractionation of a metal influences its mobility and biological toxicity. We analyzed the fractionations of V and several other metals using the BCR three-step sequential extraction procedure. Among methods for removing metal contamination, soil washing is an effective permanent treatment. We conducted experiments to select the proper reagents and to optimize extraction conditions. Citric acid, tartaric acid, oxalic acid, and Na 2 EDTA all exhibited high removal rates of the extractable state of V. With a liquid-to-solid ratio of 10, washing with 0.4 mol/L citric acid, 0.4 mol/L tartaric acid, 0.4 mol/L oxalic acid, and 0.12 mol/L Na 2 EDTA led to removal rates of 91%, 88%, 88%, and 61%, respectively. The effect of multiple washing on removal rate was also explored. According to the changes observed in metal fractionations, differences in removal rates among reagents is likely associated with their pK a value, pH in solution, and chemical structure. We concluded that treating with appropriate washing reagents under optimal conditions can greatly enhance the remediation of vanadium-contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

ParFit: A Python-Based Object-Oriented Program for Fitting Molecular Mechanics Parameters to ab Initio Data

DOE PAGES

Zahariev, Federico; De Silva, Nuwan; Gordon, Mark S.; ...

2017-02-23

Here, a newly created object-oriented program for automating the process of fitting molecular-mechanics parameters to ab initio data, termed ParFit, is presented. ParFit uses a hybrid of deterministic and stochastic genetic algorithms. ParFit can simultaneously handle several molecular-mechanics parameters in multiple molecules and can also apply symmetric and antisymmetric constraints on the optimized parameters. The simultaneous handling of several molecules enhances the transferability of the fitted parameters. ParFit is written in Python, uses a rich set of standard and nonstandard Python libraries, and can be run in parallel on multicore computer systems. As an example, a series of phosphine oxides,more » important for metal extraction chemistry, are parametrized using ParFit.« less

ParFit: A Python-Based Object-Oriented Program for Fitting Molecular Mechanics Parameters to ab Initio Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zahariev, Federico; De Silva, Nuwan; Gordon, Mark S.

Here, a newly created object-oriented program for automating the process of fitting molecular-mechanics parameters to ab initio data, termed ParFit, is presented. ParFit uses a hybrid of deterministic and stochastic genetic algorithms. ParFit can simultaneously handle several molecular-mechanics parameters in multiple molecules and can also apply symmetric and antisymmetric constraints on the optimized parameters. The simultaneous handling of several molecules enhances the transferability of the fitted parameters. ParFit is written in Python, uses a rich set of standard and nonstandard Python libraries, and can be run in parallel on multicore computer systems. As an example, a series of phosphine oxides,more » important for metal extraction chemistry, are parametrized using ParFit.« less

Optimization of PCR for quantification of simian immunodeficiency virus (SIV) genomic RNA in plasma of rhesus macaques (Macaca mulatta) using armored RNA

PubMed Central

Monjure, C. J.; Tatum, C. D.; Panganiban, A. T.; Arainga, M.; Traina-Dorge, V.; Marx, P. A.; Didier, E. S.

2014-01-01

Introduction Quantification of plasma viral load (PVL) is used to monitor disease progression in SIV-infected macaques. This study was aimed at optimizing of performance characteristics of the quantitative PCR (qPCR) PVL assay. Methods The PVL quantification procedure was optimized by inclusion of an exogenous control Hepatitis C Virus armored RNA (aRNA), a plasma concentration step, extended digestion with proteinase K, and a second RNA elution step. Efficiency of viral RNA (vRNA) extraction was compared using several commercial vRNA extraction kits. Various parameters of qPCR targeting the gag region of SIVmac239, SIVsmE660 and the LTR region of SIVagmSAB were also optimized. Results Modifications of the SIV PVL qPCR procedure increased vRNA recovery, reduced inhibition and improved analytical sensitivity. The PVL values determined by this SIV PVL qPCR correlated with quantification results of SIV-RNA in the same samples using the “industry standard” method of branched-DNA (bDNA) signal amplification. Conclusions Quantification of SIV genomic RNA in plasma of rhesus macaques using this optimized SIV PVL qPCR is equivalent to the bDNA signal amplification method, less costly and more versatile. Use of heterologous aRNA as an internal control is useful for optimizing performance characteristics of PVL qPCRs. PMID:24266615

Optimization of PCR for quantification of simian immunodeficiency virus genomic RNA in plasma of rhesus macaques (Macaca mulatta) using armored RNA.

PubMed

Monjure, C J; Tatum, C D; Panganiban, A T; Arainga, M; Traina-Dorge, V; Marx, P A; Didier, E S

2014-02-01

Quantification of plasma viral load (PVL) is used to monitor disease progression in SIV-infected macaques. This study was aimed at optimizing of performance characteristics of the quantitative PCR (qPCR) PVL assay. The PVL quantification procedure was optimized by inclusion of an exogenous control hepatitis C virus armored RNA (aRNA), a plasma concentration step, extended digestion with proteinase K, and a second RNA elution step. Efficiency of viral RNA (vRNA) extraction was compared using several commercial vRNA extraction kits. Various parameters of qPCR targeting the gag region of SIVmac239, SIVsmE660, and the LTR region of SIVagmSAB were also optimized. Modifications of the SIV PVL qPCR procedure increased vRNA recovery, reduced inhibition and improved analytical sensitivity. The PVL values determined by this SIV PVL qPCR correlated with quantification results of SIV RNA in the same samples using the 'industry standard' method of branched-DNA (bDNA) signal amplification. Quantification of SIV genomic RNA in plasma of rhesus macaques using this optimized SIV PVL qPCR is equivalent to the bDNA signal amplification method, less costly and more versatile. Use of heterologous aRNA as an internal control is useful for optimizing performance characteristics of PVL qPCRs. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Optimization of passively mode-locked quasi-continuously diode-pumped Nd:GdVO4 laser in bounce geometry

NASA Astrophysics Data System (ADS)

Frank, Milan; Jelínek, Michal; Kubeček, Václav

2015-01-01

In this paper the operation of pulsed diode-pumped Nd:GdVO4 laser oscillator in bounce geometry passively modelocked using semiconductor saturable absorber mirror (SAM), generating microjoule level picosecond pulses at wavelength of 1063 nm, is reported. Optimization of the output coupling for generation either Q-switched mode locked pulse trains or cavity dumped single pulses with maximum energy was performed, which resulted in extraction of single pulses as short as 10 ps and energy of 20 uJ. In comparison with the previous results obtained with this Nd:GdVO4 oscillator and saturable absorber in transmission mode, the achieved pulse duration is five times shorter. Using different absorbers and parameters of single pulse extraction enables generation of the pulses with duration up to 100 ps with the energy in the range from 10 to 20 μJ.

Breast Cancer Recognition Using a Novel Hybrid Intelligent Method

PubMed Central

Addeh, Jalil; Ebrahimzadeh, Ata

2012-01-01

Breast cancer is the second largest cause of cancer deaths among women. At the same time, it is also among the most curable cancer types if it can be diagnosed early. This paper presents a novel hybrid intelligent method for recognition of breast cancer tumors. The proposed method includes three main modules: the feature extraction module, the classifier module, and the optimization module. In the feature extraction module, fuzzy features are proposed as the efficient characteristic of the patterns. In the classifier module, because of the promising generalization capability of support vector machines (SVM), a SVM-based classifier is proposed. In support vector machine training, the hyperparameters have very important roles for its recognition accuracy. Therefore, in the optimization module, the bees algorithm (BA) is proposed for selecting appropriate parameters of the classifier. The proposed system is tested on Wisconsin Breast Cancer database and simulation results show that the recommended system has a high accuracy. PMID:23626945

Optimization of the production conditions of the lipase produced by Bacillus cereus from rice flour through Plackett-Burman Design (PBD) and response surface methodology (RSM).

PubMed

Vasiee, Alireza; Behbahani, Behrooz Alizadeh; Yazdi, Farideh Tabatabaei; Moradi, Samira

2016-12-01

In this study, the screening of lipase positive bacteria from rice flour was carried out by Rhodamin B agar plate method. Bacillus cereus was identified by 16S rDNA method. Screening of the appropriate variables and optimization of the lipase production was performed using Plackett-Burman design (PBD) and response surface methodology (RSM). Among the isolated bacteria, an aerobic Bacillus cereus strain was recognized as the best lipase-producing bacteria (177.3 ± 20 U/ml). Given the results, the optimal enzyme production conditions were achieved with coriander seed extract (CSE)/yeast extract ratio of 16.9 w/w, olive oil (OO) and MgCl 2 concentration of 2.37 g/L and 24.23 mM, respectively. In these conditions, the lipase activity (LA) was predicted 343 U/mL that was approximately close to the predicted value (324 U/mL), which was increased 1.83 fold LA compared with the non-optimized lipase. The kinetic parameters of V max and K m for the lipase were measured 0.367 μM/min.mL and 5.3 mM, respectively. The lipase producing Bacillus cereus was isolated and RSM was used for the optimization of enzyme production. The CSE/yeast extract ratio of 16.9 w/w, OO concentration of 2.37 g/L and MgCl 2 concentration of 24.23 mM, were found to be the optimal conditions of the enzyme production process. LA at optimal enzyme production conditions was observed 1.83 times more than the non-optimal conditions. Ultimately, it can be concluded that the isolated B. cereus from rice flour is a proper source of lipase. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development and optimization of a novel sample preparation method cored on functionalized nanofibers mat-solid-phase extraction for the simultaneous efficient extraction of illegal anionic and cationic dyes in foods.

PubMed

Qi, Feifei; Jian, Ningge; Qian, Liangliang; Cao, Weixin; Xu, Qian; Li, Jian

2017-09-01

A simple and efficient three-step sample preparation method was developed and optimized for the simultaneous analysis of illegal anionic and cationic dyes (acid orange 7, metanil yellow, auramine-O, and chrysoidine) in food samples. A novel solid-phase extraction (SPE) procedure based on nanofibers mat (NFsM) was proposed after solvent extraction and freeze-salting out purification. The preferred SPE sorbent was selected from five functionalized NFsMs by orthogonal experimental design, and the optimization of SPE parameters was achieved through response surface methodology (RSM) based on the Box-Behnken design (BBD). Under the optimal conditions, the target analytes could be completely adsorbed by polypyrrole-functionalized polyacrylonitrile NFsM (PPy/PAN NFsM), and the eluent was directly analyzed by high-performance liquid chromatography-diode array detection (HPLC-DAD). The limits of detection (LODs) were between 0.002 and 0.01 mg kg -1 , and satisfactory linearity with correlation coefficients (R > 0.99) for each dye in all samples was achieved. Compared with the Chinese standard method and the published methods, the proposed method was simplified greatly with much lower requirement of sorbent (5.0 mg) and organic solvent (2.8 mL) and higher sample preparation speed (10 min/sample), while higher recovery (83.6-116.5%) and precision (RSDs < 7.1%) were obtained. With this developed method, we have successfully detected illegal ionic dyes in three common representative foods: yellow croaker, soybean products, and chili seasonings. Graphical abstract Schematic representation of the process of the three-step sample preparation.

Bioleaching of vanadium from barren stone coal and its effect on the transition of vanadium speciation and mineral phase

NASA Astrophysics Data System (ADS)

Wang, Xin; Lin, Hai; Dong, Ying-bo; Li, Gan-yu

2018-03-01

This study determined the optimal conditions required to obtain maximum vanadium extraction and examined the transition of mineral phases and vanadium speciation during the bioleaching process. Parameters including the initial pH value, initial Fe2+ concentration, solid load, and inoculum quantity were examined. The results revealed that 48.92wt% of the vanadium was extracted through bioleaching under optimal conditions. Comparatively, the chemical leaching yield (H2SO4, pH 2.0) showed a slower and milder increase in vanadium yield. The vanadium bioleaching yield was 35.11wt% greater than the chemical leaching yield. The Community Bureau of Reference (BCR) sequential extraction results revealed that 88.62wt% of vanadium existed in the residual fraction. The bacteria substantially changed the distribution of the vanadium speciation during the leaching process, and the residual fraction decreased to 48.44wt%. The X-ray diffraction (XRD) and Fourier transform infrared (FTIR) results provided evidence that the crystal lattice structure of muscovite was destroyed by the bacteria.

Enhanced extraction of astragalosides from Radix Astragali by negative pressure cavitation-accelerated enzyme pretreatment.

PubMed

Yan, Ming-Ming; Chen, Cai-Yun; Zhao, Bao-Shan; Zu, Yuan-Gang; Fu, Yu-Jie; Liu, Wei; Efferth, Thomas

2010-10-01

The optimal conditions for extraction of astragalosides III and IV (AGs III and IV) in Radix Astragali by negative pressure cavitation-accelerated enzyme pretreatment were studied on the basis of a Box-Behnken design and response surface methodology. Experimental results showed that negative pressure, amount of enzyme and incubation temperature were the main factors governing the enzyme pretreatment of Radix Astragali. The optimum parameters were obtained as follows: negative pressure -0.08 Mpa, amount of enzyme 1.48% (w/w of materials) and incubation temperature 45 degrees C. Under the optimal conditions, the maximal extraction yields of AGs III and IV were 0.103 and 0.325 mg/g, which were 41.67% and 65.31% increased as compared to those without enzyme pretreatment, respectively. The effect of negative pressure cavitation and enzyme pretreatment on the structural changes of plant cells was observed by scanning electron microscopy. In conclusion, negative pressure cavitation-accelerated enzyme pretreatment was proved to be environment-friendly and economical, and could be used in secondary metabolites production. Copyright 2010 Elsevier Ltd. All rights reserved.

Optimizing the recovery of copper from electroplating rinse bath solution by hollow fiber membrane.

PubMed

Oskay, Kürşad Oğuz; Kul, Mehmet

2015-01-01

This study aimed to recover and remove copper from industrial model wastewater solution by non-dispersive solvent extraction (NDSX). Two mathematical models were developed to simulate the performance of an integrated extraction-stripping process, based on the use of hollow fiber contactors using the response surface method. The models allow one to predict the time dependent efficiencies of the two phases involved in individual extraction or stripping processes. The optimal recovery efficiency parameters were determined as 227 g/L of H2SO4 concentration, 1.22 feed/strip ratio, 450 mL/min flow rate (115.9 cm/min. flow velocity) and 15 volume % LIX 84-I concentration in 270 min by central composite design (CCD). At these optimum conditions, the experimental value of recovery efficiency was 95.88%, which was in close agreement with the 97.75% efficiency value predicted by the model. At the end of the process, almost all the copper in the model wastewater solution was removed and recovered as CuSO4.5H2O salt, which can be reused in the copper electroplating industry.

Preparation of free, soluble conjugate, and insoluble-bound phenolic compounds from peels of rambutan (Nephelium lappaceum) and evaluation of antioxidant activities in vitro.

PubMed

Sun, Liping; Zhang, Huilin; Zhuang, Yongliang

2012-02-01

The soluble phenolic compounds of rambutan peels (RP) were extracted by microwave-assisted extraction (MAE) and the operating parameters were optimized. The optimal conditions obtained were ethanol concentration of 80.85%, extraction time of 58.39 s, and the ratio of liquid to solid of 24.51:1. The soluble phenolic content by MAE was 213.76 mg GAE/g DW. The free, soluble conjugate, and insoluble-boaund phenolic compounds were prepared by alkaline hydrolysis, and the contents of 3 fractions were 185.12, 27.98 and 9.37 mg GAE/g DW, respectively. The contents of syringic acid and p-coumaric acid were high in the free fraction, showing 16.86 and 19.44 mg/g DW, and the soluble conjugate and insoluble-bound phenolics were mainly composed of gallic acid and caffeic acid. Furthermore, the antioxidant activities of 3 fractions were evaluated in 5 model systems. Results indicated that the free fraction had high antioxidant activities, compared with the soluble conjugate and insoluble-bound fractions. © 2012 Institute of Food Technologists®

Determination of total arsenic and arsenic(III) in phosphate fertilizers by hydride generation atomic absorption spectrometry after ultrasound-assisted extraction based on a control acid media.

PubMed

Rezende, Helen Cristine; Coelho, Nivia Maria Melo

2014-01-01

An ultrasound-assisted extraction procedure was developed for determination of inorganic arsenic (As) in phosphate fertilizer by hydride generation atomic absorption spectrometry. The variables that affect the hydride generation step were optimized, including the reducer, acid, sample flow rate, and concentrations of the acid and reducer. The determination of As(lll) was performed through the simple control of solution pH with a 0.5 M citric acid-sodium citrate buffer solution at pH 4.5, and total As was determined after a pre-reduction reaction with 1.0% (w/v) thiourea. Ultrasound-assisted acid extraction was performed, and the parameters sonication time and acid and Triton X-114 concentrations were optimized using a 23 factorial design and central composite design. LODs for As(lll) and total As were 0.029 and 0.022 microg/L, respectively. The accuracy of the method was confirmed with certified reference materials. The method was successfully applied in the determination of inorganic As in phosphate fertilizer samples.

Sensitive determination of cadmium using solidified floating organic drop microextraction-slotted quartz tube-flame atomic absorption spectroscopy.

PubMed

Akkaya, Erhan; Chormey, Dotse Selali; Bakırdere, Sezgin

2017-09-20

In this study, solidified floating organic drop microextraction (SFODME) by 1-undecanol was combined with slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) for the determination of cadmium at trace levels. Formation of a complex with 4,4'-dimethyl-2,2'-bipyridine facilitated the extraction of cadmium from aqueous solutions. Several chemical variables were optimized in order to obtain high extraction outputs. Parameters such as concentration of the ligand, pH, and amount of buffer solution were optimized to enhance the formation of cadmium complex. The SFODME method was assisted by dispersion of extractor solvent into aqueous solutions using 2-propanol. Under the optimum extraction and instrumental conditions, the limit of detection and limit of quantitation values obtained for cadmium using the combined methods (SFODME-SQT-FAAS) were found to be 0.4 and 1.3 μg L -1 , respectively. Matrix effects on the method were also examined for tap water and wastewater, and spiked recovery results were found to be very satisfactory. Graphical Abstract SFODME-SQT-FAAS system for sensitive determination of cadmium.

Electrodeposited polyaniline as a fiber coating for solid-phase microextraction of organochlorine pesticides from water.

PubMed

Li, Xiang; Zhong, Ming; Chen, Jianmin

2008-08-01

The study on the performance of polyaniline as a fiber coating for solid-phase microextraction (SPME) purposes has been reported. Polyaniline coatings were directly electrodeposited on the surface of a stainless steel wire and applied for the extraction of some organochlorine pesticides (OCPs) from water samples. Analyses were performed using GC-electron capture detection (GC-ECD). The results obtained show that polyaniline fiber coating is suitable for the successful extraction of organochlorine compounds. This behavior is most probably due to the porous surface structure of polyaniline film, which provides large surface areas and allowed for high extraction efficiency. Experimental parameters such as adsorption and desorption conditions were studied and optimized. The optimized method has an acceptable linearity, with a concentration range of 1-5000 ng/L. Single fiber repeatability and fiber-to-fiber reproducibility were less than 12 and 17%, respectively. High environmental resistance and lower cost are among the advantages of polyaniline fibers over commercially available SPME fibers. The developed method was applied to the analysis of real water samples from Yangtse River and Tianmu Lake.

Bisphenol A, 4-t-octylphenol, and 4-nonylphenol determination in serum by Hybrid Solid Phase Extraction-Precipitation Technology technique tailored to liquid chromatography-tandem mass spectrometry.

PubMed

Asimakopoulos, Alexandros G; Thomaidis, Nikolaos S

2015-04-01

A rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and optimized for the simultaneous determination of bisphenol A, 4-t-octylphenol and 4-nonylphenol in human blood serum. For the first time, the electrospray ionization (ESI) parameters of probe position, voltage potential, sheath gas flow rate, auxiliary gas flow rate, and ion transfer tube temperature were thoroughly studied and optimized for each phenol by a univariate approach. As a consequence, low instrumental limits of detection were reported, demonstrating at 0.2 ng/mL (in solvent matrix) excellent injection repeatability (RSD<14.5%) and a confirmation peak for all target phenols. Extraction and purification of serum was performed by the novel Hybrid Solid Phase Extraction-Precipitation Technology technique (Hybrid SPE-PPT). The limits of detection in human blood serum were 0.80, 1.3 and 1.4 ng/mL for BPA, 4-t-OP and 4-NP, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

Feature Vector Construction Method for IRIS Recognition

NASA Astrophysics Data System (ADS)

Odinokikh, G.; Fartukov, A.; Korobkin, M.; Yoo, J.

2017-05-01

One of the basic stages of iris recognition pipeline is iris feature vector construction procedure. The procedure represents the extraction of iris texture information relevant to its subsequent comparison. Thorough investigation of feature vectors obtained from iris showed that not all the vector elements are equally relevant. There are two characteristics which determine the vector element utility: fragility and discriminability. Conventional iris feature extraction methods consider the concept of fragility as the feature vector instability without respect to the nature of such instability appearance. This work separates sources of the instability into natural and encodinginduced which helps deeply investigate each source of instability independently. According to the separation concept, a novel approach of iris feature vector construction is proposed. The approach consists of two steps: iris feature extraction using Gabor filtering with optimal parameters and quantization with separated preliminary optimized fragility thresholds. The proposed method has been tested on two different datasets of iris images captured under changing environmental conditions. The testing results show that the proposed method surpasses all the methods considered as a prior art by recognition accuracy on both datasets.

A microextraction procedure based on a task-specific ionic liquid for the separation and preconcentration of lead ions from red lipstick and pine leaves.

PubMed

Saljooqi, Asma; Shamspur, Tayebeh; Mohamadi, Maryam; Afzali, Daryoush; Mostafavi, Ali

2015-05-01

First, the extraction and preconcentration of ultratrace amounts of lead(II) ions was performed using microliter volumes of a task-specific ionic liquid. The remarkable properties of ionic liquids were added to the advantages of microextraction procedure. The ionic liquid used was trioctylmethylammonium thiosalicylate, which formed a lead thiolate complex due to the chelating effect of the ortho-positioned carboxylate relative to thiol functionality. So, trioctylmethylammonium thiosalicylate played the roles of both chelating agent and extraction solvent simultaneously. Hence, there is no need to use a ligand. The main parameters affecting the efficiency of the method were investigated and optimized. Under optimized conditions, this approach showed a linear range of 2.0-24.0 ng/mL with a detection limit of 0.0010 ng/mL. The proposed method was applied to the extraction and preconcentration of lead from red lipstick and pine leaves samples prior to electrothermal atomic absorption spectroscopic determination. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A study on the antimicrobial efficacy of RF oxygen plasma and neem extract treated cotton fabrics

NASA Astrophysics Data System (ADS)

Vaideki, K.; Jayakumar, S.; Thilagavathi, G.; Rajendran, R.

2007-06-01

The paper deals with a thorough investigation on the antimicrobial activity of RF oxygen plasma and Azadirachtin (neem extract) treated cotton fabric. The hydrophilicity of cotton fabric was found to improve when treated with RF oxygen plasma. The process parameters such as electrode gap, time of exposure and oxygen pressure have been varied to study their effect on improving the hydrophilicity of the cotton fabric. The static immersion test has been carried out to assess the hydrophilicity of the oxygen plasma treated samples and the process parameters were optimized based on these test results. The formation of carbonyl group during surface modification in the plasma treated sample was analysed using FTIR studies. The surface morphology has been studied using SEM micrographs. The antimicrobial activity was imparted to the RF oxygen plasma treated samples using methanolic extract of neem leaves containing Azadirachtin. The antimicrobial activity of these samples has been analysed and compared with the activity of the cotton fabric treated with neem extract alone. The investigation reveals that the surface modification due to RF oxygen plasma was found to increase the hydrophilicity and hence the antimicrobial activity of the cotton fabric when treated with Azadirachtin.

Total flavonoids content in the raw material and aqueous extractives from Bauhinia monandra Kurz (Caesalpiniaceae).

PubMed

Fernandes, Ana Josane Dantas; Ferreira, Magda Rhayanny Assunção; Randau, Karina Perrelli; de Souza, Tatiane Pereira; Soares, Luiz Alberto Lira

2012-01-01

The aim of this work was to evaluate the spectrophotometric methodology for determining the total flavonoid content (TFC) in herbal drug and derived products from Bauhinia monandra Kurz. Several analytical parameters from this method grounded on the complex formed between flavonoids and AlCl₃ were evaluated such as herbal amount (0.25 to 1.25 g); solvent composition (ethanol 40 to 80%, v/v); as well as the reaction time and AlCl₃ concentration (2 to 9%, w/v). The method was adjusted to aqueous extractives and its performance studied through precision, linearity and preliminary robustness. The results showed an important dependence of the method response from reaction time, AlCl₃ concentration, sample amount, and solvent mixture. After choosing the optimized condition, the method was applied for the matrixes (herbal material and extractives), showing precision lower than 5% (for both parameters repeatability and intermediate precision), coefficient of determination higher than 0.99, and no important influence could be observed for slight variations from wavelength or AlCl₃ concentration. Thus, it could be concluded that the evaluated analytical procedure was suitable to quantify the total flavonoid content in raw material and aqueous extractives from leaves of B. monandra.

Experimental Determination of the Dynamic Hydraulic Transfer Function for the J-2X Oxidizer Turbopump. Part One; Methodology

NASA Technical Reports Server (NTRS)

Zoladz, Tom; Patel, Sandeep; Lee, Erik; Karon, Dave

2011-01-01

An advanced methodology for extracting the hydraulic dynamic pump transfer matrix (Yp) for a cavitating liquid rocket engine turbopump inducer+impeller has been developed. The transfer function is required for integrated vehicle pogo stability analysis as well as optimization of local inducer pumping stability. Laboratory pulsed subscale waterflow test of the J-2X oxygen turbo pump is introduced and our new extraction method applied to the data collected. From accurate measures of pump inlet and discharge perturbational mass flows and pressures, and one-dimensional flow models that represents complete waterflow loop physics, we are able to derive Yp and hence extract the characteristic pump parameters: compliance, pump gain, impedance, mass flow gain. Detailed modeling is necessary to accurately translate instrument plane measurements to the pump inlet and discharge and extract Yp. We present the MSFC Dynamic Lump Parameter Fluid Model Framework and describe critical dynamic component details. We report on fit minimization techniques, cost (fitness) function derivation, and resulting model fits to our experimental data are presented. Comparisons are made to alternate techniques for spatially translating measurement stations to actual pump inlet and discharge.

Tannin extracts from immature fruits of Terminalia chebula Fructus Retz. promote cutaneous wound healing in rats

PubMed Central

2011-01-01

Background Tannins extracted from immature fruits of Terminalia chebula Fructus Retz. are considered as effective components promoting the process of wound healing. The objective of this study is to explore the optimal extraction and purification technology (OEPT) of tannins, while studying the use of this drug in the treatment of a cutaneous wound of rat as well as its antibacterial effects. Methods The content of tannin extracts was measured by the casein method, and antibacterial ability was studied by the micro-dilution method in vitro. In wound healing experiment, animals in group Ⅰ, Ⅱ and Ⅲ were treated with vaseline ointment, tannin extracts (tannin content: 81%) and erythromycin ointment, respectively (5 mg of ointment were applied on each wound). To evaluate the process of wound healing, selected pharmacological and biochemical parameters were applied. Results After optimal extraction and purification, content of tannin extracts was increased to 81%. Tannin extracts showed the inhibition of Staphylococcus aureus and Klebsiella Pneumonia in vitro. After excision of wounds, on days 7 and 10, the percent of wound contraction of group Ⅱ was higher than that of group Ⅰ. After being hurt with wounds, on days 3, 7, and 10, the wound healing quality of group Ⅱ was found to be better than that of group Ⅰ in terms of granulation formation and collagen organization. After wound creation, on day 3, the vascular endothelial growth factor expression of group Ⅱ was higher than that of group Ⅰ. Conclusion The results suggest that tannin extracts from dried immature fruits of Terminalia chebula Fructus Retz. can promote cutaneous wound healing in rats, probably resulting from a powerful anti-bacterial and angiogenic activity of the extracts. PMID:21982053

An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides.

PubMed

Wang, Ziming; Zhao, Xin; Xu, Xu; Wu, Lijie; Su, Rui; Zhao, Yajing; Jiang, Chengfei; Zhang, Hanqi; Ma, Qiang; Lu, Chunmei; Dong, Deming

2013-01-14

A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (μ-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60°C for 10 min. The extracts obtained by MAE-μ-SPE were directly analyzed by GC-MS without any clean-up process. The recoveries were in the range of 93.5-104.6%, and the relative standard deviations were lower than 8.7%. Copyright © 2012 Elsevier B.V. All rights reserved.

[Mass Transfer Kinetics Model of Ultrasonic Extraction of Pomegranate Peel Polyphenols].

PubMed

Wang, Zhan-yi; Zhang, Li-hua; Wang, Yu-hai; Zhang, Yuan-hu; Ma, Li; Zheng, Dan-dan

2015-05-01

The dynamic mathematical model of ultrasonic extraction of polyphenols from pomegranate peel was constructed with the Fick's second law as the theoretical basis. The spherical model was selected, with mass concentrations of pomegranate peel polyphenols as the index, 50% ethanol as the extraction solvent and ultrasonic extraction as the extraction method. In different test conditions including the liquid ratio, extraction temperature and extraction time, a series of kinetic parameters were solved, such as the extraction process (k), relative raffinate rate, surface diffusion coefficient(D(S)), half life (t½) and the apparent activation energy (E(a)). With the extraction temperature increasing, k and D(S) were gradually increased with t½ decreasing,which indicated that the elevated temperature was favorable to the extraction of pomegranate peel polyphenols. The exponential equation of relative raffinate rate showed that the established numerical dynamics model fitted the extraction of pomegranate peel polyphenols, and the relationship between the reaction conditions and pomegranate peel polyphenols concentration was well reflected by the model. Based on the experimental results, a feasible and reliable kinetic model for ultrasonic extraction of polyphenols from pomegranate peel is established, which can be used for the optimization control of engineering magnifying production.

Multiple functional ionic liquids based dispersive liquid-liquid microextraction combined with high performance chromatography for the determination of phenolic compounds in water samples.

PubMed

Sun, Jian-Nan; Chen, Juan; Shi, Yan-Ping

2014-07-01

A new mode of ionic liquid based dispersive liquid-liquid microextraction (IL-DLLME) is developed. In this work, [C6MIm][PF6] was chosen as the extraction solvent, and two kinds of hydrophilic ionic liquids, [EMIm][BF4] and [BSO3HMIm][OTf], functioned as the dispersive solvent. So in the whole extraction procedure, no organic solvent was used. With the aid of SO3H group, the acidic compound was extracted from the sample solution without pH adjustment. Two phenolic compounds, namely, 2-naphthol and 4-nitrophenol were chosen as the target analytes. Important parameters affecting the extraction efficiency, such as the type of hydrophilic ionic liquids, the volume ratio of [EMIm][BF4] to [BSO3HMIm][OTf], type and volume of extraction solvent, pH value of sample solution, sonication time, extraction time and centrifugation time were investigated and optimized. Under the optimized extraction conditions, the method exhibited good sensitivity with the limits of detection (LODs) at 5.5 μg L(-1)and 10.0 μg L(-1) for 4-nitrophenol and 2-naphthol, respectively. Good linearity over the concentration ranges of 24-384 μg L(-1) for 4-nitrophenol and 28-336 μg L(-1) for 2-naphthol was obtained with correlation coefficients of 0.9998 and 0.9961, respectively. The proposed method can directly extract acidic compound from environmental sample or even more complex sample matrix without any pH adjustment procedure. Copyright © 2014 Elsevier B.V. All rights reserved.

Polypyrrole-magnetite dispersive micro-solid-phase extraction combined with ultraviolet-visible spectrophotometry for the determination of rhodamine 6G and crystal violet in textile wastewater.

PubMed

Kamaruddin, Amirah Farhan; Sanagi, Mohd Marsin; Wan Ibrahim, Wan Aini; Md Shukri, Dyia S; Abdul Keyon, Aemi S

2017-11-01

Polypyrrole-magnetite dispersive micro-solid-phase extraction method combined with ultraviolet-visible spectrophotometry was developed for the determination of selected cationic dyes in textile wastewater. Polypyrrole-magnetite was used as adsorbent due to its thermal stability, magnetic properties, and ability to adsorb Rhodamine 6G and crystal violet. Dispersive micro-solid-phase extraction parameters were optimized, including sample pH, adsorbent amount, extraction time, and desorption solvent. The optimum polypyrrole-magnetite dispersive micro-solid phase-extraction conditions were sample pH 8, 60 mg polypyrrole-magnetite adsorbent, 5 min of extraction time, and acetonitrile as the desorption solvent. Under the optimized conditions, the polypyrrole-magnetite dispersive micro-solid-phase extraction with ultraviolet-visible method showed good linearity in the range of 0.05-7 mg/L (R 2  > 0.9980). The method also showed a good limit of detection for the dyes (0.05 mg/L) and good analyte recoveries (97.4-111.3%) with relative standard deviations < 10%. The method was successfully applied to the analysis of dyes in textile wastewater samples where the concentration found was 1.03 mg (RSD ±7.9%) and 1.13 mg/L (RSD ± 4.6%) for Rhodamine 6G and crystal violet, respectively. It can be concluded that this method can be adopted for the rapid extraction and determination of dyes at trace concentration levels. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A modified QuEChERS method for the determination of some herbicides in yogurt and milk by high performance liquid chromatography.

PubMed

Li, Na; Lei, Lei; Nian, Li; Zhang, Rui; Wu, Shuting; Ren, Ruibing; Wang, Yeqiang; Zhang, Hanqi; Yu, Aimin

2013-02-15

A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was applied to the extraction of triazines and phenylureas from milk and yogurt. The herbicides was extracted by the mixture of ethyl acetate and n-hexane and cleaned by primary secondary amine (10mg/mL). The frozen-out centrifugation was applied to further remove fatty. The proposed method can achieve efficient extraction and cleanup. Some experimental parameters, such as extraction method, extraction solvent and adsorbent, pH of sample solution, extraction time and amount of primary secondary amine and sodium chloride were investigated and optimized. The precision and absolute recoveries of eight herbicides vary from 0.07 to 5.86% and from 78.9 to 99.9%, respectively. The detection limits for simeton, monuron, chlorotoluron, simetryne, atrazine, karmex, ametryne and propazine range from 0.15 to 0.35 ng/mL. Copyright © 2012 Elsevier B.V. All rights reserved.

CFD simulation of copper(II) extraction with TFA in non-dispersive hollow fiber membrane contactors.

PubMed

Muhammad, Amir; Younas, Mohammad; Rezakazemi, Mashallah

2018-04-01

This study presents computational fluid dynamics (CFD) simulation of dispersion-free liquid-liquid extraction of copper(II) with trifluoroacetylacetone (TFA) in hollow fiber membrane contactor (HFMC). Mass and momentum balance Navier-Stokes equations were coupled to address the transport of copper(II) solute across membrane contactor. Model equations were simulated using COMSOL Multiphysics™. The simulation was run to study the detailed concentration distribution of copper(II) and to investigate the effects of various parameters like membrane characteristics, partition coefficient, and flow configuration on extraction efficiency. Once-through extraction was found to be increased from 10 to 100% when partition coefficient was raised from 1 to 10. Similarly, the extraction efficiency was almost doubled when porosity to tortuosity ratio of membrane was increased from 0.05 to 0.81. Furthermore, the study revealed that CFD can be used as an effective optimization tool for the development of economical membrane-based dispersion-free extraction processes.

Numerical analysis of light extraction enhancement of GaN-based thin-film flip-chip light-emitting diodes with high-refractive-index buckling nanostructures

NASA Astrophysics Data System (ADS)

Yue, Qing-Yang; Yang, Yang; Cheng, Zhen-Jia; Guo, Cheng-Shan

2018-06-01

In this work, the light extraction efficiency enhancement of GaN-based thin-film flip-chip (TFFC) light-emitting diodes (LEDs) with high-refractive-index (TiO2) buckling nanostructures was studied using the three-dimensional finite difference time domain method. Compared with 2-D photonic crystals, the buckling structures have the advantages of a random directionality and a broad distribution in periodicity, which can effectively extract the guided light propagating in all azimuthal directions over a wide spectrum. Numerical studies revealed that the light extraction efficiency of buckling-structured LEDs reaches 1.1 times that of triangular lattice photonic crystals. The effects of the buckling structure feature sizes and the thickness of the N-GaN layer on the light extraction efficiency for TFFC LEDs were also investigated systematically. With optimized structural parameters, a significant light extraction enhancement of about 2.6 times was achieved for TiO2 buckling-structured TFFC LEDs compared with planar LEDs.

Modeling and verification of process parameters for the production of tannase by Aspergillus oryzae under submerged fermentation using agro-wastes.

PubMed

Varadharajan, Venkatramanan; Vadivel, Sudhan Shanmuga; Ramaswamy, Arulvel; Sundharamurthy, Venkatesaprabhu; Chandrasekar, Priyadharshini

2017-01-01

Tannase production by Aspergillus oryzae using various agro-wastes as substrates by submerged fermentation was studied in this research. The microbe was isolated from degrading corn kernel obtained from the corn fields at Tiruchengode, India. The microbial identification was done using 18S rRNA gene analysis. The agro-wastes chosen for the study were pomegranate rind, Cassia auriculata flower, black gram husk, and tea dust. The process parameters chosen for optimization study were substrate concentration, pH, temperature, and incubation period. During one variable at a time optimization, the pomegranate rind extract produced maximum tannase activity of 138.12 IU/mL and it was chosen as the best substrate for further experiments. The quadratic model was found to be the effective model for prediction of tannase production by A. oryzae. The optimized conditions predicted by response surface methodology (RSM) with genetic algorithm (GA) were 1.996% substrate concentration, pH of 4.89, temperature of 34.91 °C, and an incubation time of 70.65 H with maximum tannase activity of 138.363 IU/mL. The confirmatory experiment under optimized conditions showed tannase activity of 139.22 IU/mL. Hence, RSM-GA pair was successfully used in this study to optimize the process parameters required for the production of tannase using pomegranate rind. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

The Hull Method for Selecting the Number of Common Factors

ERIC Educational Resources Information Center

Lorenzo-Seva, Urbano; Timmerman, Marieke E.; Kiers, Henk A. L.

2011-01-01

A common problem in exploratory factor analysis is how many factors need to be extracted from a particular data set. We propose a new method for selecting the number of major common factors: the Hull method, which aims to find a model with an optimal balance between model fit and number of parameters. We examine the performance of the method in an…

Validation of a GC-MS/MS method for simultaneous determination of 86 persistent organic pollutants in marine sediments by pressurized liquid extraction followed by stir bar sorptive extraction.

PubMed

Camino-Sánchez, F J; Zafra-Gómez, Alberto; Pérez-Trujillo, J P; Conde-González, J E; Marques, J C; Vílchez, José Luis

2011-08-01

A multiresidue method for the analysis of 86 persistent pollutants in marine sediments at ultra-trace level has been developed and validated using pressurized liquid extraction (PLE) and stir-bar sorptive extraction (SBSE) coupled with thermal desorption and gas chromatography-triple quadrupole mass spectrometry (TD-GC-MS/MS QqQ). The compounds analyzed belong to various families such as polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polybrominated diphenylethers, organophosphorus and organochlorine pesticides and other pesticides such as urons, and triazines. The analytes have very different polarities and log K(ow) values, which is an important parameter in the optimization of a SBSE method. Due to PLE high efficiency and throughput rates, along with the proven ability for multiresidue analysis and excellent sensitivity of SBSE, we present an efficient method. The limits of quantification obtained ranged from 0.014 to 1.0 ng g(-1), with detection limits below pg g(-1) levels. In order to validate the proposed methodology, quality parameters such as recovery, linearity and reproducibility were studied. Recoveries ranged from 63% to 119%, reproducibility (in terms of Relative Standard Deviation for ten determinations) was lower than 35% in all cases, and determination coefficients higher than 0.990 for all analytes. The main factors that affect PLE, SBSE and GC-MS/MS procedures were optimized. The method was applied to the analysis of nine marine sediments obtained from the nine main submarine wastewater discharge points (emissaries) presents along the coast of Tenerife Island (Canary Islands, Spain). Copyright © 2011 Elsevier Ltd. All rights reserved.

Investigation of interaction between magnetic silica particles and lambda phage DNA fragment.

PubMed

Smerkova, Kristyna; Dostalova, Simona; Vaculovicova, Marketa; Kynicky, Jindrich; Trnkova, Libuse; Kralik, Miroslav; Adam, Vojtech; Hubalek, Jaromir; Provaznik, Ivo; Kizek, Rene

2013-12-01

Nucleic acids belong to the most important molecules and therefore the understanding of their properties, function and behavior is crucial. Even though a range of analytical and biochemical methods have been developed for this purpose, one common step is essential for all of them - isolation of the nucleic acid from the from complex sample matrix. The use of magnetic particles for the separation of nucleic acids has many advantages over other isolation methods. In this study, an isolation procedure for extraction of DNA was optimized. Each step of the isolation process including washing, immobilization and elution was optimized and therefore the efficiency was increased from 1.7% to 28.7% and the total time was shortened from 75 to 30min comparing to the previously described method. Quantification of the particular parameter influence was performed by square-wave voltammetry using hanging drop mercury electrode. Further, we compared the optimized method with standard chloroform extraction and applied on isolation of DNA from Staphylococcus aureus and Escherichia coli. Copyright © 2013 Elsevier B.V. All rights reserved.

Separation and purification of both tea seed polysaccharide and saponin from camellia cake extract using macroporous resin.

PubMed

Yang, Pengjie; Zhou, Mingda; Zhou, Chengyun; Wang, Qian; Zhang, Fangfang; Chen, Jian

2015-02-01

A novel method to separate and purify tea seed polysaccharide and tea seed saponin from camellia cake extract by macroporous resin was developed. Among four kinds of resins (AB-8, NKA-9, XDA-6, and D4020) tested, AB-8 macroporous resin possessed optimal separating capacity for the two substances and thus was selected for the separation, in which deionized water was used to elute tea seed polysaccharide, 0.25% NaOH solution to remove the undesired pigments, and 90% ethanol to elute tea seed saponin. Further dynamic adsorption/desorption experiments on AB-8 resin-based column chromatography were conducted to obtain the optimal parameters. Under optimal dynamic adsorption and desorption conditions, 18.7 and 11.8% yield of tea seed polysaccharide and tea seed saponin were obtained with purities of 89.2 and 96.0%, respectively. The developed method provides a potential approach for the large-scale production of tea seed polysaccharide and tea seed saponin from camellia cake. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improved conditions for the application of solid phase microextraction prior to HPLC-FLD analysis of anatoxin-a.

PubMed

Rellán, Sandra; Gago-Martínez, Ana

2007-10-01

Solid phase microextraction coupled with high performance liquid chromatography with fluorescence detection has been optimized and evaluated for a simple, rapid, and selective analysis of anatoxin-a. Four kinds of fiber (100 microm polydimethylsiloxane, 60 microm polydimethylsiloxane/divinylbenzene, 50 microm Carbowax/templated resin-100, and 85 microm polyacrylate) were evaluated for an efficient extraction of the toxin. Parameters relating to the desorption step, such as desorption mode, solvent composition, time for both static and dynamic desorption, as well as carryover, have been studied and optimized. The derivatization process was investigated using NBD-F as derivatizing reagent. Anatoxin-a derivative was formed when the anatoxin-a-loaded fiber was inserted in a vial containing 5 microL of NBD-F. Variables affecting extraction such us ionic strength, temperature, and time have been also optimized. The results obtained showed linearity in the range of 10-2000 ng and a limit of detection of 0.29 ng/mL in river water. The presented method has been applied to different environmental samples.

Optimization and validation of a method using UHPLC-fluorescence for the analysis of polycyclic aromatic hydrocarbons in cold-pressed vegetable oils.

PubMed

Silva, Simone Alves da; Sampaio, Geni Rodrigues; Torres, Elizabeth Aparecida Ferraz da Silva

2017-04-15

Among the different food categories, the oils and fats are important sources of exposure to polycyclic aromatic hydrocarbons (PAHs), a group of organic chemical contaminants. The use of a validated method is essential to obtain reliable analytical results since the legislation establishes maximum limits in different foods. The objective of this study was to optimize and validate a method for the quantification of four PAHs [benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(a)pyrene] in vegetable oils. The samples were submitted to liquid-liquid extraction, followed by solid-phase extraction, and analyzed by ultra-high performance liquid chromatography. Under the optimized conditions, the validation parameters were evaluated according to the INMETRO Guidelines: linearity (r2 >0.99), selectivity (no matrix interference), limits of detection (0.08-0.30μgkg -1 ) and quantification (0.25-1.00μgkg -1 ), recovery (80.13-100.04%), repeatability and intermediate precision (<10% RSD). The method was found to be adequate for routine analysis of PAHs in the vegetable oils evaluated. Copyright © 2016. Published by Elsevier Ltd.

Optimization of Ionic Liquid-Assisted Extraction of Biflavonoids from Selaginella doederleinii and Evaluation of Its Antioxidant and Antitumor Activity.

PubMed

Li, Dan; Qian, Yan; Tian, Yu-Jia; Yuan, Shi-Meng; Wei, Wei; Wang, Gang

2017-04-07

As new green solvents, ionic liquids (ILs) have been generally applied in the extraction and separation of natural product. In this study, microwave assisted extraction based on IL (IL-MAE) was firstly employed to extract total biflavonoids from Selaginella doederleinii . Based on single-factor experiment, microwave power (300-700 W), extract time (30-50 min) and extract temperature (40-60 °C) on total bioflavonoids and antioxidant activities of the extracts were further investigated by a Box-Behnken design of response surface methodology (RSM) selecting total bioflavonoids yields and IC 50 of radical scavenging as index. Besides antioxidant activity of the extract was evaluated by a 2,2-diphenyl-1-picrylhydarzyl (DPPH) and 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate (ABTS) radical scavenging assay, ferric reducing power assay and chelation of ferrous ions assay, and then anticaner activity was also researched against A549 cell line and 7721 cell line. The results illustrated that three factors and their interactions could be well suited for second-order polynomial models ( p < 0.05). Through process parameters, optimization of the extract (460 W, 40 min, and 45 °C) and detection of bioactivity, the yield of total bioflavonoids was 16.83 mg/g and IC 50 value was 56.24 μg/mL, respectively, indicating the extract has better anti-oxidation effect and antitumor activity. Furthermore, IL-MAE was the most efficient extracting method compared with MAE and Soxhlet extraction, which could improve extraction efficiency in a shorter time and at a lower temperature. In general, ILs-MAE was first adopted to establish a novel and green extraction process on the yields of total biflavonoids from S. doederleinii . In addition, the extract of containing biflavones showed potent antioxidant and anticancer capacity as a utilized valuable bioactive source for natural medicine.

Dynamic fabric phase sorptive extraction for a group of pharmaceuticals and personal care products from environmental waters.

PubMed

Lakade, Sameer S; Borrull, Francesc; Furton, Kenneth G; Kabir, Abuzar; Marcé, Rosa Maria; Fontanals, Núria

2016-07-22

This paper describes for the first time the use of a new extraction technique, based on fabric phase sorptive extraction (FPSE). This new mode proposes the extraction of the analytes in dynamic mode in order to reduce the extraction time. Dynamic fabric phase sorptive extraction (DFPSE) followed by liquid chromatography-tandem mass spectrometry was evaluated for the extraction of a group of pharmaceuticals and personal care products (PPCPs) from environmental water samples. Different parameters affecting the extraction were optimized and best conditions were achieved when 50mL of sample at pH 3 was passed through 3 disks and analytes retained were eluted with 10mL of ethyl acetate. The recoveries were higher than 60% for most of compounds with the exception of the most polar ones (between 8% and 38%). The analytical method was validated with environmental samples such as river water and effluent and influent wastewater, and good performance was obtained. The analysis of samples revealed the presence of some PPCPs at low ngL(-1) concentrations. Copyright © 2016 Elsevier B.V. All rights reserved.

Microwave-assisted extraction and purification of chlorogenic acid from by-products of Eucommia Ulmoides Oliver and its potential anti-tumor activity.

PubMed

Shao, P; Zhang, J F; Chen, X X; Sun, P L

2015-08-01

An efficient method for the rapid extraction, separation and purification of chlorogenic acid (CGA) from by-products of Eucommia Ulmoides Oliver (E. ulmoides) by microwave-assisted extraction (MAE) coupled with high-speed counter-current chromatography (HSCCC) was developed. The optimal MAE parameters were evaluated by response surface methodology (RSM), and they were extraction time of 12 min, microwave power of 420 W, ethanol concentration of 75 %, solvent/sample ratio of 30:1 (mL/g), yield of CGA reached 3.59 %. The crude extract was separated and purified directly by HSCCC using ethyl acetate-butyl alcohol-water (3:1:4, v/v) as the two-phase solvent system. The 14.5 mg of CGA with the purity of 98.7 % was obtained in one-step separation from 400 mg of crude extract. The chemical structure of CGA was verified with IR, ESI-MS analysis. Meanwhile, the purified CGA extract was evaluated by MTT assay and results indicate that CGA extract exhibited potential anti-tumor activity for AGS gastric cancer cell.

Nonparametric variational optimization of reaction coordinates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banushkina, Polina V.; Krivov, Sergei V., E-mail: s.krivov@leeds.ac.uk

State of the art realistic simulations of complex atomic processes commonly produce trajectories of large size, making the development of automated analysis tools very important. A popular approach aimed at extracting dynamical information consists of projecting these trajectories into optimally selected reaction coordinates or collective variables. For equilibrium dynamics between any two boundary states, the committor function also known as the folding probability in protein folding studies is often considered as the optimal coordinate. To determine it, one selects a functional form with many parameters and trains it on the trajectories using various criteria. A major problem with such anmore » approach is that a poor initial choice of the functional form may lead to sub-optimal results. Here, we describe an approach which allows one to optimize the reaction coordinate without selecting its functional form and thus avoiding this source of error.« less

Validated determination of losartan and valsartan in human plasma by stir bar sorptive extraction based on acrylate monolithic polymer, liquid chromatographic analysis and experimental design methodology.

PubMed

Babarahimi, Vida; Talebpour, Zahra; Haghighi, Farideh; Adib, Nuoshin; Vahidi, Hamed

2018-05-10

In our previous work, a new monolithic coating based on vinylpyrrolidone-ethylene glycol dimethacrylate polymer was introduced for stir bar sorptive extraction. The formulation of the prepared vinylpyrrolidone-ethylene glycol dimethacrylate monolithic polymer was optimized and the satisfactory quality of prepared coated stir bar was demonstrated. In this work, the prepared stir bar was utilized in combination with ultrasound-assisted liquid desorption, followed by high-performance liquid chromatography with ultraviolet detection for the simultaneous determination of losartan (LOS) and valsartan (VAS) in human plasma samples. In a comparison study, the extraction efficiency of the prepared stir bar was accompanied much higher extraction efficiency than the two commercial stir bars (polydimethylsiloxand and polyacrylate) for both target compounds. In order to improve the desorption efficiency of LOS and VAS, the best values for effective parameters on desorption step were selected systematically. Also, the effective parameters on extraction step were optimized using a Box-Behnken design. Under the optimum conditions, the analytical performance of the proposed method displayed excellent linear dynamic ranges for LOS (24-1000 ng mL -1 ) and VAS (91-1000 ng mL -1 ), with correlation coefficients of 0.9998 and 0.9971 and detection limits of 7 and 27 ng mL -1 , respectively. The intra- and inter-day recovery ranged from 98 to 117%, and the relative standard deviations were less than 8%. Finally, the proposed technique was successfully applied to the analysis of LOS and VAS at their therapeutic levels in volunteer patient plasma sample. The obtained results were confirmed using liquid chromatography-mass spectrometry. The proposed technique was more rapid than previously reported stir bar sorptive extraction techniques based on monolithic coatings, and exhibited lower detection limits in comparison with similar methods for the determination of LOS and VLS in biological fluids. The obtained results were demonstrated that the lower selectivity of UV in comparison with MS detection was rectified by appropriate sample preparation through proposed extraction method to eliminate as many interfering compounds as possible. Copyright © 2018 Elsevier B.V. All rights reserved.

Characterization, parameter estimation, and aircraft response statistics of atmospheric turbulence

NASA Technical Reports Server (NTRS)

Mark, W. D.

1981-01-01

A nonGaussian three component model of atmospheric turbulence is postulated that accounts for readily observable features of turbulence velocity records, their autocorrelation functions, and their spectra. Methods for computing probability density functions and mean exceedance rates of a generic aircraft response variable are developed using nonGaussian turbulence characterizations readily extracted from velocity recordings. A maximum likelihood method is developed for optimal estimation of the integral scale and intensity of records possessing von Karman transverse of longitudinal spectra. Formulas for the variances of such parameter estimates are developed. The maximum likelihood and least-square approaches are combined to yield a method for estimating the autocorrelation function parameters of a two component model for turbulence.

Codestream-Based Identification of JPEG 2000 Images with Different Coding Parameters

NASA Astrophysics Data System (ADS)

Watanabe, Osamu; Fukuhara, Takahiro; Kiya, Hitoshi

A method of identifying JPEG 2000 images with different coding parameters, such as code-block sizes, quantization-step sizes, and resolution levels, is presented. It does not produce false-negative matches regardless of different coding parameters (compression rate, code-block size, and discrete wavelet transform (DWT) resolutions levels) or quantization step sizes. This feature is not provided by conventional methods. Moreover, the proposed approach is fast because it uses the number of zero-bit-planes that can be extracted from the JPEG 2000 codestream by only parsing the header information without embedded block coding with optimized truncation (EBCOT) decoding. The experimental results revealed the effectiveness of image identification based on the new method.

Wavelet-bounded empirical mode decomposition for measured time series analysis

NASA Astrophysics Data System (ADS)

Moore, Keegan J.; Kurt, Mehmet; Eriten, Melih; McFarland, D. Michael; Bergman, Lawrence A.; Vakakis, Alexander F.

2018-01-01

Empirical mode decomposition (EMD) is a powerful technique for separating the transient responses of nonlinear and nonstationary systems into finite sets of nearly orthogonal components, called intrinsic mode functions (IMFs), which represent the dynamics on different characteristic time scales. However, a deficiency of EMD is the mixing of two or more components in a single IMF, which can drastically affect the physical meaning of the empirical decomposition results. In this paper, we present a new approached based on EMD, designated as wavelet-bounded empirical mode decomposition (WBEMD), which is a closed-loop, optimization-based solution to the problem of mode mixing. The optimization routine relies on maximizing the isolation of an IMF around a characteristic frequency. This isolation is measured by fitting a bounding function around the IMF in the frequency domain and computing the area under this function. It follows that a large (small) area corresponds to a poorly (well) separated IMF. An optimization routine is developed based on this result with the objective of minimizing the bounding-function area and with the masking signal parameters serving as free parameters, such that a well-separated IMF is extracted. As examples of application of WBEMD we apply the proposed method, first to a stationary, two-component signal, and then to the numerically simulated response of a cantilever beam with an essentially nonlinear end attachment. We find that WBEMD vastly improves upon EMD and that the extracted sets of IMFs provide insight into the underlying physics of the response of each system.

Determination of sudan dyes in red wine and fruit juice using ionic liquid-based liquid-liquid microextraction and high-performance liquid chromatography.

PubMed

Sun, Shuo; Wang, Ying; Yu, Wenzhi; Zhao, Tianqi; Gao, Shiqian; Kang, Mingqin; Zhang, Yupu; Zhang, Hanqi; Yu, Yong

2011-07-01

The liquid-liquid microextraction (LLME) was developed for extracting sudan dyes from red wine and fruit juice. Room temperature ionic liquid was used as the extraction solvent. The target analytes were determined by high-performance liquid chromatography. The extraction parameters were optimized. The optimal conditions are as follows: volume of [C(6)MIM][PF(6)] 50 μL; the extraction time 10 min; pH value of the sample solution 7.0; NaCl concentration in sample solution 5%. The extraction recoveries for the analytes in red wine and fruit samples are 86.79-108.28 and 68.54-85.66%, whereas RSDs are 1.42-5.12 and 1.43-6.19%, respectively. The limits of detection and quantification were 0.428 and 1.426 ng/mL for sudan I, 0.938 and 3.127 ng/mL for sudan II, 1.334 and 4.445 ng/mL for sudan III, 1.454 and 4.846 ng/mL for sudan IV, respectively. Compared with conventional liquid-liquid extraction (CLLE) and ultrasonic extraction (UE), when LLME was applied, the sample amount was less (LLME: 4 mL; CLLE: 10 mL; UE: 10 mL), the extraction time was shorter (LLME: 15 min; CLLE: 110 min; UE: 50 min) and the extraction solvent amount was less (LLME: 0.05 mL IL; CLLE: 15 mL hexane; UE: 20 mL hexane). The proposed method offers a simple, rapid and efficient sample preparation for determining sudan dyes in red wine and fruit juice samples. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid analysis of aflatoxins B1, B2, and ochratoxin A in rice samples using dispersive liquid-liquid microextraction combined with HPLC.

PubMed

Lai, Xian-Wen; Sun, Dai-Li; Ruan, Chun-Qiang; Zhang, He; Liu, Cheng-Lan

2014-01-01

A novel, simple, and rapid method is presented for the analysis of aflatoxin B1, aflatoxin B2, and ochratoxin A in rice samples by dispersive liquid-liquid microextraction combined with LC and fluorescence detection. After extraction of the rice samples with a mixture of acetonitrile/water/acetic acid, mycotoxins were rapidly partitioned into a small volume of organic solvent (chloroform) by dispersive liquid-liquid microextraction. The three mycotoxins were simultaneously determined by LC with fluorescence detection after precolumn derivatization for aflatoxin B1 and B2. Parameters affecting both extraction and dispersive liquid-liquid microextraction procedures, including the extraction solvent, the type and volume of extractant, the volume of dispersive solvent, the addition of salt, the pH and the extraction time, were optimized. The optimized protocol provided an enrichment factor of approximately 1.25 and with detection of limits (0.06-0.5 μg/kg) below the maximum levels imposed by current regulations for aflatoxins and ochratoxin A. The mean recovery of three mycotoxins ranged from 82.9-112%, with a RSD less than 7.9% in all cases. The method was successfully applied to measure mycotoxins in commercial rice samples collected from local supermarkets in China. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbon molecular sieve based micro-matrix-solid-phase dispersion for the extraction of polyphenols in pomegranate peel by UHPLC-Q-TOF/MS.

PubMed

Du, Li-Jing; Huang, Jian-Ping; Wang, Bin; Wang, Chen-Hui; Wang, Qiu-Yan; Hu, Yu-Han; Yi, Ling; Cao, Jun; Peng, Li-Qing; Chen, Yu-Bo; Zhang, Qi-Dong

2018-06-04

A rapid, simple and efficient sample extraction method based on micro-matrix-solid-phase dispersion (micro-MSPD) was applied to the extraction of polyphenols from pomegranate peel. Five target analytes were determined by ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry. Carbon molecular sieve (CMS) was firstly used as dispersant to improve extraction efficiency in micro-MSPD. The major micro-MSPD parameters, such as type of dispersant, amount of dispersant, grinding time and the type and the volume of elution solvents, were studied and optimized. Under optimized conditions, 26 mg of pomegranate peel was dispersed with 32.5 mg of CMS, the grinding time was selected as 90 s, the dispersed sample was eluted with 100 μL of methanol. Results showed that the proposed method was of good linearity for concentrations of analytes against their peak areas (coefficient of determination r 2 >0.990), the limit of the detection was as low as 3.2 ng/mL, and the spiking recoveries were between 88.1% and 106%. Satisfactory results were obtained for the extraction of gallic acid, punicalagin A, punicalagin B, catechin and ellagic acid from pomegranate peel sample, which demonstrated nice reliability and high sensitivity of this approach. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Determination of pyrazole and pyrrole pesticides in environmental water samples by solid-phase extraction using multi-walled carbon nanotubes as adsorbent coupled with high-performance liquid chromatography.

PubMed

Ma, Jiping; Lu, Xi; Xia, Yan; Yan, Fengli

2015-02-01

A solid-phase extraction (SPE) method using multi-walled carbon nanotubes as adsorbent coupled with high-performance liquid chromatography was developed for the determination of four pyrazole and pyrrole pesticides (fenpyroximate, chlorfenapyr, fipronil and flusilazole) in environmental water samples. Several parameters, such as extraction adsorbent, elution solvent and volume and sample loading flow rate were optimized to obtain high SPE recoveries and extraction efficiency. The calibration curves for the pesticides extracted were linear in the range of 0.05-10 μg L(-1) for chlorfenapyr and fenpyroximate and 0.05-20 μg L(-1) for fipronil and flusilazole, with the correlation coefficients (r(2)) between 0.9966 and 0.9990. The method gave good precisions (relative standard deviation %) from 2.9 to 10.1% for real spiked samples from reservoir water and seawater; method recoveries ranged 92.2-105.9 and 98.5-103.9% for real spiked samples from reservoir water and seawater, respectively. Limits of detection (S/N = 3) for the method were determined to be 8-19 ng L(-1). The optimized method was successfully applied to the determination of four pesticides of pyrazoles and pyrroles in real environmental water samples. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Automated diagnosis of coronary artery disease (CAD) patients using optimized SVM.

PubMed

Davari Dolatabadi, Azam; Khadem, Siamak Esmael Zadeh; Asl, Babak Mohammadzadeh

2017-01-01

Currently Coronary Artery Disease (CAD) is one of the most prevalent diseases, and also can lead to death, disability and economic loss in patients who suffer from cardiovascular disease. Diagnostic procedures of this disease by medical teams are typically invasive, although they do not satisfy the required accuracy. In this study, we have proposed a methodology for the automatic diagnosis of normal and Coronary Artery Disease conditions using Heart Rate Variability (HRV) signal extracted from electrocardiogram (ECG). The features are extracted from HRV signal in time, frequency and nonlinear domains. The Principal Component Analysis (PCA) is applied to reduce the dimension of the extracted features in order to reduce computational complexity and to reveal the hidden information underlaid in the data. Finally, Support Vector Machine (SVM) classifier has been utilized to classify two classes of data using the extracted distinguishing features. In this paper, parameters of the SVM have been optimized in order to improve the accuracy. Provided reports in this paper indicate that the detection of CAD class from normal class using the proposed algorithm was performed with accuracy of 99.2%, sensitivity of 98.43%, and specificity of 100%. This study has shown that methods which are based on the feature extraction of the biomedical signals are an appropriate approach to predict the health situation of the patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Determination of volatile organic compounds in pen inks by a dynamic headspace needle trap device combined with gas chromatography-mass spectrometry.

PubMed

Zang, Xiaohuan; Liang, Weiqian; Chang, Qingyun; Wu, Tong; Wang, Chun; Wang, Zhi

2017-09-01

Some harmful volatile organic compounds (VOCs), such as methylbenzene, ethylbenzene, xylene, chlorobenzene and bromobenzene, are the commonly found chemicals in pen inks. In this work, a dynamic headspace needle-trap device (D-HS-NTD) with a ZIF-8-derived nanoporous carbon (ZIF-8-NPC) as the adsorbent was developed for the extraction of some VOCs in different pen inks prior to GC-MS detection. The main important influencing experimental parameters including the flow rate of the purge gas N 2 , extraction temperature, extraction time, desorption temperature and desorption time for the extraction were optimized to obtain a high extraction efficiency. Under the optimized conditions, a good linearity was obtained in the concentration range of 0.1-400μgkg -1 with the correlation coefficients (r) ranging from 0.9911 to 0.9990 for the eleven VOCs. The LODs at a signal-to-noise ratio of 3 (S/N=3) were measured to be 10-20ngkg -1 for the VOCs. The developed method was applied to determine the VOCs from 20 pen inks. The recoveries of the VOCs for the method at the spiking levels of 0.5 and 20.0μgkg -1 fell in the range from 80.0% to 108%. Copyright © 2017. Published by Elsevier B.V.

Sensitive determination of estrogens in environmental waters treated with polymeric ionic liquid-based stir cake sorptive extraction and liquid chromatographic analysis.

PubMed

Chen, Lei; Mei, Meng; Huang, Xiaojia; Yuan, Dongxing

2016-05-15

A simple, sensitive and environmentally friendly method using polymeric ionic liquid-based stir cake sorptive extraction followed by high performance liquid chromatography with diode array detection (HPLC/DAD) has been developed for efficient quantification of six selected estrogens in environmental waters. To extract trace estrogens effectively, a poly (1-ally-3-vinylimidazolium chloride-co-ethylene dimethacrylate) monolithic cake was prepared and used as the sorbent of stir cake sorptive extraction (SCSE). The effects of preparation conditions of sorbent and extraction parameters of SCSE for estrogens were investigated and optimized. Under optimal conditions, the developed method showed satisfactory analytical performance for targeted analytes. Low limits of detection (S/N=3) and quantification limits (S/N=10) were achieved within the range of 0.024-0.057 µg/L and 0.08-0.19 µg/L, respectively. Good linearity of method was obtained for analytes with the correlation coefficients (R(2)) above 0.99. At the same time, satisfactory method repeatability and reproducibility was achieved in terms of intra- and inter-day precisions, respectively. Finally, the established SCSE-HPLC/DAD method was successfully applied for the determination of estrogens in different environmental water samples. Recoveries obtained for the determination of estrogens in spiked samples ranged from 71.2% to 108%, with RSDs below 10% in all cases. Copyright © 2016 Elsevier B.V. All rights reserved.

Highly efficient decolorization of Malachite Green by a novel Micrococcus sp. strain BD15.

PubMed

Du, Lin-Na; Zhao, Ming; Li, Gang; Zhao, Xiao-Ping; Zhao, Yu-Hua

2011-08-01

Malachite Green (MG) is used for a variety of applications but is also known to be carcinogenic and mutagenic. In this study, a novel Micrococcus sp. (strain BD15) was observed to efficiently decolorize MG. The purposes of this study were to explore the optimal conditions for decolorization and to evaluate the potential use of this strain for MG decolorization. Optical microscope and UV-visible analyses were carried out to determine whether the decolorization was due to biosorption or biodegradation. A Plackett-Burman design was employed to investigate the effect of various parameters on decolorization, and response surface methodology was then used to explore the optimal decolorization conditions. Kinetics analysis and antimicrobial activity tests were also performed. The results indicated that the decolorization by the strain was mainly due to biodegradation. Concentrations of MG, urea, and yeast extract and inoculum size had significantly positive effects on MG decolorization, while concentrations of CuCl(2) and MgCl(2), and temperature had significantly negative effects. The interaction between different parameters could significantly affect decolorization, and the optimal conditions for decolorization were 1.0 g/L urea, 0.9 g/L yeast extract, 100 mg/L MG, 0.1 g/L inoculums (dry weight), and incubation at 25.2°C. Under the optimal conditions, 96.9% of MG was removed by the strain within 1 h, which represents highly efficient microbial decolorization. Moreover, the kinetic data for decolorization fit a second-order model well, and the strain showed a good MG detoxification capability. Based on the results of this study, we propose Micrococcus sp. strain BD15 as an excellent candidate strain for MG removal from wastewater.

Ultrasound-assisted extraction of azadirachtin from dried entire fruits of Azadirachta indica A. Juss. (Meliaceae) and its determination by a validated HPLC-PDA method.

PubMed

de Paula, Joelma Abadia Marciano; Brito, Lucas Ferreira; Caetano, Karen Lorena Ferreira Neves; de Morais Rodrigues, Mariana Cristina; Borges, Leonardo Luiz; da Conceição, Edemilson Cardoso

2016-01-01

Azadirachta indica A. Juss., also known as neem, is a Meliaceae family tree from India. It is globally known for the insecticidal properties of its limonoid tetranortriterpenoid derivatives, such as azadirachtin. This work aimed to optimize the azadirachtin ultrasound-assisted extraction (UAE) and validate the HPLC-PDA analytical method for the measurement of this marker in neem dried fruit extracts. Box-Behnken design and response surface methodology (RSM) were used to investigate the effect of process variables on the UAE. Three independent variables, including ethanol concentration (%, w/w), temperature (°C), and material-to-solvent ratio (gmL(-1)), were studied. The azadirachtin content (µgmL(-1)), i.e., dependent variable, was quantified by the HPLC-PDA analytical method. Isocratic reversed-phase chromatography was performed using acetonitrile/water (40:60), a flow of 1.0mLmin(-1), detection at 214nm, and C18 column (250×4.6mm(2), 5µm). The primary validation parameters were determined according to ICH guidelines and Brazilian legislation. The results demonstrated that the optimal UAE condition was obtained with ethanol concentration range of 75-80% (w/w), temperature of 30°C, and material-to-solvent ratio of 0.55gmL(-1). The HPLC-PDA analytical method proved to be simple, selective, linear, precise, accurate and robust. The experimental values of azadirachtin content under optimal UAE conditions were in good agreement with the RSM predicted values and were superior to the azadirachtin content of percolated extract. Such findings suggest that UAE is a more efficient extractive process in addition to being simple, fast, and inexpensive. Copyright © 2015 Elsevier B.V. All rights reserved.

Efficient approach for the extraction of proanthocyanidins from Cinnamomum longepaniculatum leaves using ultrasonic irradiation and an evaluation of their inhibition activity on digestive enzymes and antioxidant activity in vitro.

PubMed

Liu, Zaizhi; Mo, Kailin; Fei, Shimin; Zu, Yuangang; Yang, Lei

2017-08-01

Proanthocyanidins were separated for the first time from Cinnamomum longepaniculatum leaves. An experiment-based extraction strategy was used to research the efficiency of an ultrasound-assisted method for proanthocyanidins extraction. The Plackett-Burman design results revealed that the ultrasonication time, ultrasonic power and liquid/solid ratio were the most significant parameters among the six variables in the extraction process. Upon further optimization of the Box-Behnken design, the optimal conditions were obtained as follows: extraction temperature, 100°C; ethanol concentration, 70%; pH 5; ultrasonication power, 660 W; ultrasonication time, 44 min; liquid/solid ratio, 20 mL/g. Under the obtained conditions, the extraction yield of the proanthocyanidins using the ultrasonic-assisted method was 7.88 ± 0.21 mg/g, which is higher than that obtained using traditional methods. The phloroglucinolysis products of the proanthocyanidins, including the terminal units and derivatives from the extension units, were tentatively identified using a liquid chromatography with tandem mass spectrometry analysis. Cinnamomum longepaniculatum proanthocyanidins have promising antioxidant and anti-nutritional properties. In summary, an ultrasound-assisted method in combination with a response surface experimental design is an efficient methodology for the sufficient isolation of proanthocyanidins from Cinnamomum longepaniculatum leaves, and this method could be used for the separation of other bioactive compounds. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mass spectrometric identification and toxicity assessment of degraded products of aflatoxin B1 and B2 by Corymbia citriodora aqueous extracts

PubMed Central

Iram, Wajiha; Anjum, Tehmina; Iqbal, Mazhar; Ghaffar, Abdul; Abbas, Mateen

2015-01-01

This study explores the detoxification potential of Corymbia citriodora plant extracts against aflatoxin B1 and B2 (AFB1; 100 μg L−1 and AFB2; 50 μg L−1) in In vitro and In vivo assays. Detoxification was qualitatively and quantitatively analyzed by TLC and HPLC, respectively. The study was carried out by using different parameters of optimal temperature, pH and incubation time period. Results indicated that C. citriodora leaf extract(s) more effectively degrade AFB1 and AFB2 i.e. 95.21% and 92.95% respectively than C. citriodora branch extract, under optimized conditions. The structural elucidation of degraded toxin products was done by LCMS/MS analysis. Ten degraded products of AFB1 and AFB2 and their fragmentation pathways were proposed based on molecular formulas and MS/MS spectra. Toxicity of these degraded products was significantly reduced as compared to that of parent compounds because of the removal of double bond in the terminal furan ring. The biological toxicity of degraded toxin was further analyzed by brine shrimps bioassay, which showed that only 17.5% mortality in larvae was recorded as compared to untreated toxin where 92.5% mortality was observed after 96hr of incubation. Therefore, our finding suggests that C. citriodora leaf extract can be used as an effective tool for the detoxification of aflatoxins. PMID:26423838

Optimization of squalene produced from crude palm oil waste

NASA Astrophysics Data System (ADS)

Wandira, Irda; Legowo, Evita H.; Widiputri, Diah I.

2017-01-01

Squalene is a hydrocarbon originally and still mostly extracted from shark liver oil. Due to environmental issues over shark hunting, there have been efforts to extract squalene from alternative sources, such as Palm Fatty Acid Distillate (PFAD), one of crude palm oil (CPO) wastes. Previous researches have shown that squalene can be extracted from PFAD using saponification process followed with liquid-liquid extraction process although the method had yet to be optimized in order to optimize the amount of squalene extracted from PFAD. The optimization was done by optimizing both processes of squalene extraction method: saponification and liquid-liquid extraction. The factors utilized in the saponification process optimization were KOH concentration and saponification duration while during the liquid-liquid extraction (LLE) process optimization, the factors used were the volumes of distilled water and dichloromethane. The optimum percentage of squalene content in the extract (24.08%) was achieved by saponifying the PFAD with 50%w/v KOH for 60 minutes and subjecting the saponified PFAD to LLE, utilizing 100 ml of distilled water along with 3 times addition of fresh dichloromethane, 75 ml each; those factors would be utilized in the optimum squalene extraction method.

Chemometrics Optimized Extraction Procedures, Phytosynergistic Blending and in vitro Screening of Natural Enzyme Inhibitors Amongst Leaves of Tulsi, Banyan and Jamun.

PubMed

De, Baishakhi; Bhandari, Koushik; Singla, Rajeev K; Katakam, Prakash; Samanta, Tanmoy; Kushwaha, Dilip Kumar; Gundamaraju, Rohit; Mitra, Analava

2015-10-01

Tulsi, Banyan, and Jamun are popular Indian medicinal plants with notable hypoglycemic potentials. Now the work reports chemo-profiling of the three species with in-vitro screening approach for natural enzyme inhibitors (NEIs) against enzymes pathogenic for type 2 diabetes. Further along with the chemometrics optimized extraction process technology, phyto-synergistic studies of the composite polyherbal blends have also been reported. Chemometrically optimized extraction procedures, ratios of polyherbal composites to achieve phyto-synergistic actions, and in-vitro screening of NEIs amongst leaves of Tulsi, Banyan, and Jamun. The extraction process parameters of the leaves of three plant species (Ficus benghalensis, Syzigium cumini and Ocimum sanctum) were optimized by rotatable central composite design of chemometrics so as to get maximal yield of bio-actives. Phyto-blends of three species were prepared so as to achieve synergistic antidiabetic and antioxidant potentials and the ratios were optimized by chemometrics. Next, for in vitro screening of natural enzyme inhibitors the individual leaf extracts as well as composite blends were subjected to assay procedures to see their inhibitory potentials against the enzymes pathogenic in type 2 diabetes. The antioxidant potentials were also estimated by DPPH radical scavenging, ABTS, FRAP and Dot Blot assay. Considering response surface methodology studies and from the solutions obtained using desirability function, it was found that hydro-ethanolic or methanolic solvent ratio of 52.46 ± 1.6 and at a temperature of 20.17 ± 0.6 gave an optimum yield of polyphenols with minimal chlorophyll leaching. The species also showed the presence of glycosides, alkaloids, and saponins. Composites in the ratios of 1:1:1 and 1:1:2 gave synergistic effects in terms of polyphenol yield and anti-oxidant potentials. All composites (1:1:1, 1:2:1, 2:1:1, 1:1:2) showed synergistic anti-oxidant actions. Inhibitory activities against the targeted enzymes expressed in terms of IC50 values have shown that hydro-ethanolic extracts in all cases whether individual species or composites in varying ratios gave higher IC50 values thus showing greater effectivity. Current research provides the state-of-the-art of search of NEIs amongst three species by in-vitro assays which can be further utilized for bioactivity-guided isolations of such enzyme inhibitors. Further, it reports the optimized phyto-blend ratios so as to achieve synergistic anti-oxidative actions. The current research work focuses on the optimization of the extraction process parameters and the ratios of phyto-synergistic blends of the leaves of three common medicinal plants viz. banyan, jamun and tulsi by chemometrics. Qualitative and quantitative chemo profiling of the extracts were done by different phytochemical tests and UV spectrophotometric methods. Enzymes like alpha amylase, alpha glucosidase, aldose reductase, dipeptidyl peptidase 4, angiotensin converting enzymes are found to be pathogenic in type 2 diabetes. In vitro screening of natural enzyme inhibitors amongst individual extracts and composite blends were carried out by different assay procedures and the potency expressed in terms of IC50 values. Antioxidant potentials were estimated by DPPH radical scavenging, ABTS, FRAP and Dot Blot assay. Hydroalcoholic solvent (50:50) gave maximal yield of bio-actives with minimal chlorophyll leaching. Hydroethanolic extract of tulsi showed maximal antioxidant effect. Though all composites showed synergism, maximal effects were shown by the composite (1:1:2) in terms of polyphenol yield, antioxidant effect and inhibitory actions against the targeted enzymes. Abbreviations used: DPP4- dipeptidyl peptidase 4; AR- aldose reductase; ACE- angiotensin converting enzyme; PPAR-γ- peroxisome proliferator activated receptor-γ; NEIs- natural enzyme inhibitors; BE- binding energy; GLP-1- Glucagon like peptide -1; ROS- Reactive oxygen species; CAT- catalase; GSH-Px- glutathione per-oxidase; SOD- superoxide dismutase; pNPG- para-nitro phenyl-α-D-gluco-pyranoside solution; DPPH- 1,1-diphenyl-2-picrylhydrazyl; RSM- Response surface methodology; CCD- central composite design; DMSO- dimethyl sulfoxide; HHL- hippuryl-L-histidyl-L-leucine; GPN-Tos- Gly-Pro p-nitroanilide toluenesulfonate salt; ESC- experimental scavenging capacity; TSC- theoretical scavenging capacity; FRAP- Ferric Reducing Assay Procedure; ABTS- 2, 2'- azinobis (3-ethylbenzothiazoline-6 - sulfonic acid.

Chemometrics Optimized Extraction Procedures, Phytosynergistic Blending and in vitro Screening of Natural Enzyme Inhibitors Amongst Leaves of Tulsi, Banyan and Jamun

PubMed Central

De, Baishakhi; Bhandari, Koushik; Singla, Rajeev K.; Katakam, Prakash; Samanta, Tanmoy; Kushwaha, Dilip Kumar; Gundamaraju, Rohit; Mitra, Analava

2015-01-01

Background: Tulsi, Banyan, and Jamun are popular Indian medicinal plants with notable hypoglycemic potentials. Now the work reports chemo-profiling of the three species with in-vitro screening approach for natural enzyme inhibitors (NEIs) against enzymes pathogenic for type 2 diabetes. Further along with the chemometrics optimized extraction process technology, phyto-synergistic studies of the composite polyherbal blends have also been reported. Objective: Chemometrically optimized extraction procedures, ratios of polyherbal composites to achieve phyto-synergistic actions, and in-vitro screening of NEIs amongst leaves of Tulsi, Banyan, and Jamun. Materials and Methods: The extraction process parameters of the leaves of three plant species (Ficus benghalensis, Syzigium cumini and Ocimum sanctum) were optimized by rotatable central composite design of chemometrics so as to get maximal yield of bio-actives. Phyto-blends of three species were prepared so as to achieve synergistic antidiabetic and antioxidant potentials and the ratios were optimized by chemometrics. Next, for in vitro screening of natural enzyme inhibitors the individual leaf extracts as well as composite blends were subjected to assay procedures to see their inhibitory potentials against the enzymes pathogenic in type 2 diabetes. The antioxidant potentials were also estimated by DPPH radical scavenging, ABTS, FRAP and Dot Blot assay. Results: Considering response surface methodology studies and from the solutions obtained using desirability function, it was found that hydro-ethanolic or methanolic solvent ratio of 52.46 ± 1.6 and at a temperature of 20.17 ± 0.6 gave an optimum yield of polyphenols with minimal chlorophyll leaching. The species also showed the presence of glycosides, alkaloids, and saponins. Composites in the ratios of 1:1:1 and 1:1:2 gave synergistic effects in terms of polyphenol yield and anti-oxidant potentials. All composites (1:1:1, 1:2:1, 2:1:1, 1:1:2) showed synergistic anti-oxidant actions. Inhibitory activities against the targeted enzymes expressed in terms of IC50 values have shown that hydro-ethanolic extracts in all cases whether individual species or composites in varying ratios gave higher IC50 values thus showing greater effectivity. Conclusion: Current research provides the state-of-the-art of search of NEIs amongst three species by in-vitro assays which can be further utilized for bioactivity-guided isolations of such enzyme inhibitors. Further, it reports the optimized phyto-blend ratios so as to achieve synergistic anti-oxidative actions. SUMMARY The current research work focuses on the optimization of the extraction process parameters and the ratios of phyto-synergistic blends of the leaves of three common medicinal plants viz. banyan, jamun and tulsi by chemometrics. Qualitative and quantitative chemo profiling of the extracts were done by different phytochemical tests and UV spectrophotometric methods. Enzymes like alpha amylase, alpha glucosidase, aldose reductase, dipeptidyl peptidase 4, angiotensin converting enzymes are found to be pathogenic in type 2 diabetes. In vitro screening of natural enzyme inhibitors amongst individual extracts and composite blends were carried out by different assay procedures and the potency expressed in terms of IC50 values. Antioxidant potentials were estimated by DPPH radical scavenging, ABTS, FRAP and Dot Blot assay. Hydroalcoholic solvent (50:50) gave maximal yield of bio-actives with minimal chlorophyll leaching. Hydroethanolic extract of tulsi showed maximal antioxidant effect. Though all composites showed synergism, maximal effects were shown by the composite (1:1:2) in terms of polyphenol yield, antioxidant effect and inhibitory actions against the targeted enzymes. Abbreviations used: DPP4- dipeptidyl peptidase 4; AR- aldose reductase; ACE- angiotensin converting enzyme; PPAR-γ- peroxisome proliferator activated receptor-γ; NEIs- natural enzyme inhibitors; BE- binding energy; GLP-1- Glucagon like peptide -1; ROS- Reactive oxygen species; CAT- catalase; GSH-Px- glutathione per-oxidase; SOD- superoxide dismutase; pNPG- para-nitro phenyl-α-D-gluco-pyranoside solution; DPPH- 1,1-diphenyl-2-picrylhydrazyl; RSM- Response surface methodology; CCD- central composite design; DMSO- dimethyl sulfoxide; HHL- hippuryl-L-histidyl-L-leucine; GPN-Tos- Gly-Pro p-nitroanilide toluenesulfonate salt; ESC- experimental scavenging capacity; TSC- theoretical scavenging capacity; FRAP- Ferric Reducing Assay Procedure; ABTS- 2, 2’- azinobis (3-ethylbenzothiazoline-6 – sulfonic acid. PMID:27013789

Sequential fuzzy diagnosis method for motor roller bearing in variable operating conditions based on vibration analysis.

PubMed

Li, Ke; Ping, Xueliang; Wang, Huaqing; Chen, Peng; Cao, Yi

2013-06-21

A novel intelligent fault diagnosis method for motor roller bearings which operate under unsteady rotating speed and load is proposed in this paper. The pseudo Wigner-Ville distribution (PWVD) and the relative crossing information (RCI) methods are used for extracting the feature spectra from the non-stationary vibration signal measured for condition diagnosis. The RCI is used to automatically extract the feature spectrum from the time-frequency distribution of the vibration signal. The extracted feature spectrum is instantaneous, and not correlated with the rotation speed and load. By using the ant colony optimization (ACO) clustering algorithm, the synthesizing symptom parameters (SSP) for condition diagnosis are obtained. The experimental results shows that the diagnostic sensitivity of the SSP is higher than original symptom parameter (SP), and the SSP can sensitively reflect the characteristics of the feature spectrum for precise condition diagnosis. Finally, a fuzzy diagnosis method based on sequential inference and possibility theory is also proposed, by which the conditions of the machine can be identified sequentially as well.

Sequential Fuzzy Diagnosis Method for Motor Roller Bearing in Variable Operating Conditions Based on Vibration Analysis

PubMed Central

Li, Ke; Ping, Xueliang; Wang, Huaqing; Chen, Peng; Cao, Yi

2013-01-01

A novel intelligent fault diagnosis method for motor roller bearings which operate under unsteady rotating speed and load is proposed in this paper. The pseudo Wigner-Ville distribution (PWVD) and the relative crossing information (RCI) methods are used for extracting the feature spectra from the non-stationary vibration signal measured for condition diagnosis. The RCI is used to automatically extract the feature spectrum from the time-frequency distribution of the vibration signal. The extracted feature spectrum is instantaneous, and not correlated with the rotation speed and load. By using the ant colony optimization (ACO) clustering algorithm, the synthesizing symptom parameters (SSP) for condition diagnosis are obtained. The experimental results shows that the diagnostic sensitivity of the SSP is higher than original symptom parameter (SP), and the SSP can sensitively reflect the characteristics of the feature spectrum for precise condition diagnosis. Finally, a fuzzy diagnosis method based on sequential inference and possibility theory is also proposed, by which the conditions of the machine can be identified sequentially as well. PMID:23793021

[Optimization of dissolution process for superfine grinding technology on total saponins of Panax ginseng fibrous root by response surface methodology].

PubMed

Zhao, Ya; Lai, Xiao-Pin; Yao, Hai-Yan; Zhao, Ran; Wu, Yi-Na; Li, Geng

2014-03-01

To investigate the effects of superfine comminution extraction technology of ginseng total saponins from Panax ginseng fibrous root, and to make sure the optimal extraction condition. Optimal condition of ginseng total saponins from Panax ginseng fibrous root was based on single factor experiment to study the effects of crushing degree, extraction time, alcohol concentration and extraction temperature on extraction rate. Response surface method was used to investigate three main factors such as superfine comminution time, extraction time and alcohol concentration. The relationship between content of ginseng total saponins in Panax ginseng fibrous root and three factors fitted second degree polynomial models. The optimal extraction condition was 9 min of superfine comminution time, 70% of alcohol, 50 degrees C of extraction temperature and 70 min of extraction time. Under the optimal condition, ginseng total saponins from Panax ginseng fibrous root was average 94. 81%, which was consistent with the predicted value. The optimization of technology is rapid, efficient, simple and stable.

Extraction of natural colorant from purple sweet potato and dyeing of fabrics with silver nanoparticles for augmented antibacterial activity against skin pathogens.

PubMed

Velmurugan, Palanivel; Kim, Jae-In; Kim, Kangmin; Park, Jung-Hee; Lee, Kui-Jae; Chang, Woo-Suk; Park, Yool-Jin; Cho, Min; Oh, Byung-Taek

2017-08-01

The main objective of this study was to extract natural colorant from purple sweet potato powder (PSPP) via a water bath and ultrasound water bath using acidified ethanol (A. EtOH) as the extraction solvent. When optimizing the colorant extraction conditions of the solvents, acidified ethanol with ultrasound yielded a high extraction capacity and color intensity at pH2, temperature of 80°C, 20mL of A. EtOH, 1.5g of PSPP, time of 45min, and ultrasonic output power of 75W. Subsequently, the colorant was extracted using the optimized conditions for dyeing of textiles (leather, silk, and cotton). This natural colorant extraction technique can avoid serious environmental pollution during the extraction and is an alternative to synthetic dyes, using less solvent and simplified abstraction procedures. The extracted purple sweet potato natural colorant (PSPC) was used to dye leather, silk, and cotton fabrics in an eco-friendly approach with augmented antibacterial activity by in situ synthesis of silver nanoparticles (AgNPs) and dyeing. The optimal dyeing conditions for higher color strength (K/S) values were pH2 and 70°C for 45min. The colorimetric parameters L ∗ , a ∗ , b ∗ , C, and H were measured to determine the depth of the color. The Fourier transform infrared spectroscopy (FTIR) spectra of undyed control, dyed with PSPC and dyed with blend of PSPC and AgNPs treated leather, silk and cotton fabric were investigated to study the interaction among fiber type, nanoparticles, and dye. The structural morphology of leather and silk and cotton fabrics and the anchoring of AgNPs with elemental compositions were investigated by scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS). The dry and wet rubbing fastness for dye alone and dye with nanoparticles were grade 4-5 and 4, respectively. Thus, the results of the present study clearly suggest that in situ synthesis of AgNPs along with dyeing should be considered in the development of antimicrobial textile finishes. Copyright © 2017. Published by Elsevier B.V.

Application of ultrasound for enhanced extraction of prebiotic oligosaccharides from selected fruits and vegetables.

PubMed

Jovanovic-Malinovska, Ruzica; Kuzmanova, Slobodanka; Winkelhausen, Eleonora

2015-01-01

Ultrasound assisted extraction (UAE) was used to extract oligosaccharides from selected fruits (blueberry, nectarine, raspberry, watermelon) and vegetables (garlic, Jerusalem artichoke, leek, scallion, spring garlic and white onion). The individual fractions of the oligosaccharides were analyzed: 1-kestose (GF2), nystose (GF3) and 1F-β-fructofuranosylnystose (GF4) from the fructo-oligosaccharides (FOS), and raffinose and stachyose from the raffinose family oligosaccharides (RFO). Extraction parameters including solvent concentration (35-85% v/v), extraction temperature (25-50°C) and sonication time (5-15min) were examined using response surface methodology (RSM). Ethanol concentration of 63% v/v, temperature of 40°C and extraction time of 10min gave maximal concentration of the extracted oligosaccharides. The experimental values under optimal conditions were consistent with the predicted values. UAE increased the concentration of extracted oligosaccharides in all fruits and vegetables from 2 to 4-fold compared to conventional extraction. The highest increase of total oligosaccharides extracted by UAE was detected in Jerusalem artichoke, 7.17±0.348g/100gFW, compared to 1.62±0.094g/100gFW with conventional method. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis and characterization of silver nanoparticles using Caesalpinia pulcherrima flower extract and assessment of their in vitro antimicrobial, antioxidant, cytotoxic, and genotoxic activities.

PubMed

Moteriya, Pooja; Chanda, Sumitra

2017-12-01

Caesalpinia pulcherrima flower extract mediated synthesis of silver nanoparticles was attempted in the present work including optimization of some procedure parameters. Characterization of synthesized silver nanoparticles was done by various spectral analyses. The size of synthesized silver nanoparticles was 12 nm and they were spherical in shape. The green synthesized silver nanoparticles were further evaluated for antimicrobial, antioxidant, cytotoxic, and genotoxic activities; they showed good antimicrobial, antioxidant, and cytotoxic effects. Genotoxic study revealed non-toxic nature at lower concentration. Overall results suggest that the synthesized silver nanoparticles have pronounced applicability in pharmaceutical and biomedical field.

Bioleaching of copper oxide ore by Pseudomonas aeruginosa

NASA Astrophysics Data System (ADS)

Shabani, M. A.; Irannajad, M.; Azadmehr, A. R.; Meshkini, M.

2013-12-01

Bioleaching is an environmentally friendly method for extraction of metal from ores. In this study, bioleaching of copper oxide ore by Pseudomonas aeruginosa was investigated. Pseudomonas aeruginosa is a heterotrophic bacterium that can produce various organic acids in an appropriate culture medium, and these acids can operate as leaching agents. The parameters, such as particle size, glucose percentage in the culture medium, bioleaching time, and solid/liquid ratio were optimized. Optimum bioleaching conditions were found as follows: particle size of 150-177 μm, glucose percentage of 6%, bioleaching time of 8 d, and solid/liquid ratio of 1:80. Under these conditions, 53% of copper was extracted.

Low-cost Scholl-coupling microporous polymer as an efficient solid-phase microextraction coating for the detection of light aromatic compounds.

PubMed

Xie, Xintong; Wang, Junhui; Zheng, Juan; Huang, Junlong; Ni, Chuyi; Cheng, Jie; Hao, Zhengping; Ouyang, Gangfeng

2018-10-31

A cost-effective microporous polymer was synthesized using cheap monomer and catalyst via one-step Scholl-coupling reaction, and its chemical, morphological characteristics and pore structure were investigated. The as-synthesized polymer with large surface area and narrow pore distribution (centered in 1.2 nm) was prepared as a fiber coating for solid-phase microextraction (SPME). Headspace SPME was used for the extraction of the light aromatic compounds, e.g. benzene, toluene, ethylbenzene, m-xylene, naphthalene and acenaphthene. The parameters influencing the extraction and desorption efficiencies, such as extraction temperature and time, salt concentration, desorption temperature and time were investigated and optimized. The results showed that the home-made fiber had superior extraction efficiencies compared with the commercial PDMS fiber. Under the optimized conditions, low detection limits (0.01-1.3 ng/L), wide linear ranges (from 50 to 20000 ng/L to 1-20000 ng/L), good repeatability (4.2-9.3%, n = 6) and reproducibility (0.30-11%, n = 3) were achieved. Moreover, the practical applicability of the coating and proposed method was evaluated by determining the target light aromatic compounds in environmental water samples with satisfied recoveries (83.2%-116%). Copyright © 2018 Elsevier B.V. All rights reserved.

Electro-assisted solid-phase microextraction based on poly(3,4-ethylenedioxythiophen) combined with GC for the quantification of tricyclic antidepressants.

PubMed

Davarani, Saied Saeed Hosseiny; Nojavan, Saeed; Asadi, Roghayeh; Banitaba, Mohammad Hossein

2013-07-01

In this study, a platinum wire coated with poly(3,4-ethylenedioxythiophen) was used as an electro-assisted solid-phase microextraction fiber for the quantification of tricyclic antidepressant drugs in biological samples by coupling to GC employing a flame ionization detector. In this study, an electric field increased the extraction rate and recovery. The fiber used as a solid phase was synthesized by the electropolymerization of 3,4-ethylenedioxythiophen monomers onto a platinum wire. The ability of this fiber to extract imipramine, desipramine, and clomipramine by using the electro-assisted solid-phase microextraction technique was evaluated. The effect of various parameters that influence the extraction efficiency, which include solution temperature, extraction time, stirring rate, ionic strength, time and temperature of desorption, and thickness of the fiber, was optimized. Under optimized conditions, the linear ranges and regression coefficients of calibration curves were in the range of 0.5-250 and 0.990-0.998 ng/mL, respectively. Detection limits were in the range of 0.15-0.45 ng/mL. Finally, this method was applied to the determination of drugs in urine and wastewater samples and recoveries were 4.8-108.9%. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zeolite-loaded poly(dimethylsiloxane) hybrid films for highly efficient thin-film microextraction of organic volatiles in water.

PubMed

Wang, Tao; Ansai, Toshihiro; Lee, Seung-Woo

2017-01-15

ZSM-5 zeolite-loaded poly(dimethylsiloxane) (PDMS) hybrid thin films were demonstrated for efficient thin-film microextraction (TFME) coupled with gas chromatography-mass spectrometry for analyzing organic volatiles in water. The extraction efficiency for a series of aliphatic alcohols and two aromatic compounds was significantly improved owing to the presence of ZSM-5 zeolites. The extraction efficiency of the hybrid films was increased in proportion to the content of ZSM-5 in the PDMS film, with 20wt% of ZSM-5 showing the best results. The 20wt% ZSM-5/PDMS hybrid film exhibited higher volatile organic content extraction compared with the single-component PDMS film or PDMS hybrid films containing other types of zeolite (e.g., SAPO-34). Limits of detection and limits of quantitation for individual analytes were in the range of 0.0034-0.049ppb and of 0.010-0.15 ppb, respectively. The effects of experimental parameters such as extraction time and temperature were optimized, and the molecular dispersion of the zeolites in/on the hybrid film matrix was confirmed with scanning electron microscopy and atomic force microscopy. Furthermore, the optimized hybrid film was preliminarily tested for the analysis of organic volatiles contained in commercially available soft drinks. Copyright © 2016 Elsevier B.V. All rights reserved.

A dispersive liquid--liquid microextraction methodology for copper (II) in environmental samples prior to determination using microsample injection flame atomic absorption spectrometry.

PubMed

Alothman, Zeid A; Habila, Mohamed; Yilmaz, Erkan; Soylak, Mustafa

2013-01-01

A simple, environmentally friendly, and efficient dispersive liquid-liquid microextraction method combined with microsample injection flame atomic absorption spectrometry was developed for the separation and preconcentration of Cu(II). 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol (5-Br-PADAP) was used to form a hydrophobic complex of Cu(II) ions in the aqueous phase before extraction. To extract the Cu(II)-5-Br-PADAP complex from the aqueous phase to the organic phase, 2.0 mL of acetone as a disperser solvent and 200 microL of chloroform as an extraction solvent were used. The influences of important analytical parameters, such as the pH, types and volumes of the extraction and disperser solvents, amount of chelating agent, sample volume, and matrix effects, on the microextraction procedure were evaluated and optimized. Using the optimal conditions, the LOD, LOQ, preconcentration factor, and RSD were determined to be 1.4 microg/L, 4.7 microg/L, 120, and 6.5%, respectively. The accuracy of the proposed method was investigated using standard addition/recovery tests. The analysis of certified reference materials produced satisfactory analytical results. The developed method was applied for the determination of Cu in real samples.

Ultra-trace determination of Persistent Organic Pollutants in Arctic ice using stir bar sorptive extraction and gas chromatography coupled to mass spectrometry.

PubMed

Lacorte, S; Quintana, J; Tauler, R; Ventura, F; Tovar-Sánchez, A; Duarte, C M

2009-12-04

This study presents the optimization and application of an analytical method based on the use of stir bar sorptive extraction (SBSE) gas chromatography coupled to mass spectrometry (GC-MS) for the ultra-trace analysis of POPs (Persistent Organic Pollutants) in Arctic ice. In a first step, the mass-spectrometry conditions were optimized to quantify 48 compounds (polycyclic aromatic hydrocarbons, brominated diphenyl ethers, chlorinated biphenyls, and organochlorinated pesticides) at the low pg/L level. In a second step, the performance of this analytical method was evaluated to determine POPs in Arctic cores collected during an oceanographic campaign. Using a calibration range from 1 to 1800 pg/L and by adjusting acquisition parameters, limits of detection at the 0.1-99 and 102-891 pg/L for organohalogenated compounds and polycyclic aromatic hydrocarbons, respectively, were obtained by extracting 200 mL of unfiltered ice water. alpha-hexachlorocyclohexane, DDTs, chlorinated biphenyl congeners 28, 101 and 118 and brominated diphenyl ethers congeners 47 and 99 were detected in ice cores at levels between 0.5 to 258 pg/L. We emphasise the advantages and disadvantages of in situ SBSE in comparison with traditional extraction techniques used to analyze POPs in ice.