Sample records for method precision rsd
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Yu, Binbing; Yang, Harry
2017-01-01
Biological assays ( bioassays ) are procedures to estimate the potency of a substance by studying its effects on living organisms, tissues, and cells. Bioassays are essential tools for gaining insight into biologic systems and processes including, for example, the development of new drugs and monitoring environmental pollutants. Two of the most important parameters of bioassay performance are relative accuracy (bias) and precision. Although general strategies and formulas are provided in USP, a comprehensive understanding of the definitions of bias and precision remain elusive. Additionally, whether there is a beneficial use of data transformation in estimating intermediate precision remains unclear. Finally, there are various statistical estimation methods available that often pose a dilemma for the analyst who must choose the most appropriate method. To address these issues, we provide both a rigorous definition of bias and precision as well as three alternative methods for calculating relative standard deviation (RSD). All methods perform similarly when the RSD ≤10%. However, the USP estimates result in larger bias and root-mean-square error (RMSE) compared to the three proposed methods when the actual variation was large. Therefore, the USP method should not be used for routine analysis. For data with moderate skewness and deviation from normality, the estimates based on the original scale perform well. The original scale method is preferred, and the method based on log-transformation may be used for noticeably skewed data. LAY ABSTRACT: Biological assays, or bioassays, are essential in the development and manufacture of biopharmaceutical products for potency testing and quality monitoring. Two important parameters of assay performance are relative accuracy (bias) and precision. The definitions of bias and precision in USP 〈1033〉 are elusive and confusing. Another complicating issue is whether log-transformation should be used for calculating the
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Improvement in precision and trueness of quantitative XRF analysis with glass-bead method. 1
International Nuclear Information System (INIS)
Yamamoto, Yasuyuki; Ogasawara, Noriko; Yuhara, Yoshitaroh; Yokoyama, Yuichi
1995-01-01
The factors which lower the precisions of simultaneous X-ray Fluorescence (XRF) spectrometer were investigated. Especially in quantitative analyses of oxide powders with glass-bead method, X-ray optical characteristics of the equipment affects the precision of the X-ray intensities. In focused (curved) crystal spectrometers, the precision depends on the deviation of the actual size and position of the crystals from those of theoretical designs, thus the precision differs for each crystal for each element. When the deviation is large, a dispersion of the measured X-ray intensities is larger than the statistical dispersion, even though the intensity itself keeps unchanged. Moreover, a waviness of the surface of glass-beads makes the difference of the height of an analyzed surface from that of the designed one. This difference makes the change of the amount of the X-ray incident on the analyzing crystal and makes the dispersion of the X-ray intensity larger. Considering these factors, a level of the waviness must be regulated to improve the precision under exsisting XRF equipments. In this study, measurement precisions of 4 simultaneous XRF spectrometers were evaluated, and the element lead (Pb-Lβ1) was found to have the lowest precision. Relative standard deviation (RSD) of the measurements of 10 glass-beads for the same powder sample was 0.3% without the regulation of the waviness of analytical surface. With mechanical flattening of the glass-bead surface, the level of waviness, which is the maximum difference of the heights in a glass-bead, was regulated as under 30 μm, RSD was 0.038%, which is almost comparable to the statistical RSD 0.033%. (author)
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Telltale Signs and Symptoms of CRPS/RSD
... Living With CRPS/RSD Symptoms of CRPS/RSD Definition of CRPS Diagnosed: Now What? Coping Strategies Caregivers CRPS Comfortable Clothing For Youth Stories of Hope Research/Medical Clinical Guidelines Treatments Educational Presentations RSDSA Videos Accredited Course ...
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Evaluating the precision of passive sampling methods using ...
To assess these models, four different thicknesses of low-density polyethylene (LDPE) passive samplers were co-deployed for 28 days in the water column at three sites in New Bedford Harbor, MA, USA. Each sampler was pre-loaded with six PCB performance reference compounds (PRCs) to assess equilibrium status, such that the percent of PRC lost would range depending on PRC and LDPE thickness. These data allow subsequent Cfree comparisons to be made in two ways: (1) comparing Cfree derived from one thickness using different models and (2) comparing Cfree derived from the same model using different thicknesses of LDPE. Following the deployments, the percent of PRC lost ranged from 0-100%. As expected, fractional equilibrium decreased with increasing PRC molecular weight as well as sampler thickness. Overall, a total of 27 PCBs (log KOW ranging from 5.07 – 8.09) were measured at Cfree concentrations varying from 0.05 pg/L (PCB 206) to about 200 ng/L (PCB 28) on a single LDPE sampler. Relative standard deviations (RSDs) for total PCB measurements using the same thickness and varying model types range from 0.04-12% and increased with sampler thickness. Total PCB RSD for measurements using the same model and varying thickness ranged from: 6 – 30%. No RSD trends between models were observed but RSD did increase as Cfree decreased. These findings indicate that existing models yield precise and reproducible results when using LDPE and PRCs to measure Cfree. This work in
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Comparison of methods for the determination of boron in heavy water moderator
Energy Technology Data Exchange (ETDEWEB)
Green, L.W.; Davey, E.C.; Gulens, J.; Longhurst, T.H.; Mislan, J.P. (Atomic Energy of Canada Ltd., Chalk River, Ontario. Chalk River Nuclear Labs.)
1984-08-01
Five analysis methods were compared for the determination of boron in heavy water moderator: isotope dilution mass spectrometry, spectrophotometry, neutron activation, inductively coupled plasma -atomic emission spectrometry, and ion selective electrode potentiometry. Ten samples were analysed by each method; the results showed close agreement between all of the methods. Only mass spectrometry achieved the required precision (<1 percent rsd) for samples taken during initial reactor operation, but all of the methods achieved sufficient precision (<10 percent rsd) for samples taken during normal operation. For samples for which the /sup 10/B concentration must be determined, only mass spectrometry and neutron activation are applicable.
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Improving precision in gel electrophoresis by stepwisely decreasing variance components.
Schröder, Simone; Brandmüller, Asita; Deng, Xi; Ahmed, Aftab; Wätzig, Hermann
2009-10-15
Many methods have been developed in order to increase selectivity and sensitivity in proteome research. However, gel electrophoresis (GE) which is one of the major techniques in this area, is still known for its often unsatisfactory precision. Percental relative standard deviations (RSD%) up to 60% have been reported. In this case the improvement of precision and sensitivity is absolutely essential, particularly for the quality control of biopharmaceuticals. Our work reflects the remarkable and completely irregular changes of the background signal from gel to gel. This irregularity was identified as one of the governing error sources. These background changes can be strongly reduced by using a signal detection in the near-infrared (NIR) range. This particular detection method provides the most sensitive approach for conventional CCB (Colloidal Coomassie Blue) stained gels, which is reflected in a total error of just 5% (RSD%). In order to further investigate variance components in GE, an experimental Plackett-Burman screening design was performed. The influence of seven potential factors on the precision was investigated using 10 proteins with different properties analyzed by NIR detection. The results emphasized the individuality of the proteins. Completely different factors were identified to be significant for each protein. However, out of seven investigated parameters, just four showed a significant effect on some proteins, namely the parameters of: destaining time, staining temperature, changes of detergent additives (SDS and LDS) in the sample buffer, and the age of the gels. As a result, precision can only be improved individually for each protein or protein classes. Further understanding of the unique properties of proteins should enable us to improve the precision in gel electrophoresis.
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Precise and accurate isotope ratio measurements by ICP-MS.
Becker, J S; Dietze, H J
2000-09-01
The precise and accurate determination of isotope ratios by inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation ICP-MS (LA-ICP-MS) is important for quite different application fields (e.g. for isotope ratio measurements of stable isotopes in nature, especially for the investigation of isotope variation in nature or age dating, for determining isotope ratios of radiogenic elements in the nuclear industry, quality assurance of fuel material, for reprocessing plants, nuclear material accounting and radioactive waste control, for tracer experiments using stable isotopes or long-lived radionuclides in biological or medical studies). Thermal ionization mass spectrometry (TIMS), which used to be the dominant analytical technique for precise isotope ratio measurements, is being increasingly replaced for isotope ratio measurements by ICP-MS due to its excellent sensitivity, precision and good accuracy. Instrumental progress in ICP-MS was achieved by the introduction of the collision cell interface in order to dissociate many disturbing argon-based molecular ions, thermalize the ions and neutralize the disturbing argon ions of plasma gas (Ar+). The application of the collision cell in ICP-QMS results in a higher ion transmission, improved sensitivity and better precision of isotope ratio measurements compared to quadrupole ICP-MS without the collision cell [e.g., for 235U/238U approximately 1 (10 microg x L(-1) uranium) 0.07% relative standard deviation (RSD) vs. 0.2% RSD in short-term measurements (n = 5)]. A significant instrumental improvement for ICP-MS is the multicollector device (MC-ICP-MS) in order to obtain a better precision of isotope ratio measurements (with a precision of up to 0.002%, RSD). CE- and HPLC-ICP-MS are used for the separation of isobaric interferences of long-lived radionuclides and stable isotopes by determination of spallation nuclide abundances in an irradiated tantalum target.
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High-power semiconductor RSD-based switch
Energy Technology Data Exchange (ETDEWEB)
Bezuglov, V G; Galakhov, I V; Grusin, I A [All-Russian Scientific Research Inst. of Experimental Physics, Sarov (Russian Federation); and others
1997-12-31
The operating principle and test results of a high-power semiconductor RSD-based switch with the following operating parameters is described: operating voltage 25 kV, peak operating current 200 kA, maximum transferred charge 70 C. The switch is intended for use by high-power capacitor banks of state-of-the-art research facilities. The switch was evaluated for applicability in commercial pulsed systems. The possibility of increasing the peak operating current to 500 kA is demonstrated. (author). 4 figs., 2 refs.
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[Comparative data regarding two HPLC methods for determination of isoniazid].
Gârbuleţ, Daniela; Spac, A F; Dorneanu, V
2009-01-01
For the determination of isoniazide (isonicotinic acid hydrazide - HIN) two different HPLC methods were developed and validated. Both experiments were performed using a Waters 2695 liquid chromatograph and a UV - Waters 2489 detector. The first method (I) used a Nucleosil 100-10 C18 column (250 x 4.6 mm), a mobile phase formed by a mixture of acetonitrile/10(-2) M oxalic acid (80/20) and a flow of 1.5 mL/ min; detection was done at 230 nm. The second method (II) used a Luna 100-5 C18 column (250 x 4.6 mm), a mobile phase formed by a mixture of methanol/acetate buffer, pH = 5.0 (20/ 80), a flow of 1 mL/min; detection was done at 270 nm. Both methods were validated, the correlation coefficients were 0.9998 (I) and 0.9999 (II), the detection limits were 0.6 microg/mL (I) and 0.055 microg/mL (II), the quantitation limits were 1.9 microg/mL (I) and 0.2 microg/ mL (II). There were also studied: the system precision (RSD = 0.1692% (I) and 0.2000% (II)), the method precision (RSD = 1.1844% (I) and 0.6170% (II)) and the intermediate precision (RSD = 1.8058% (I) and 0.5970% (II)). The accuracy was good, the calculated recoveries were 102.66% (I) and 101.36 (II). Both validated methods were applied for HIN determination from tablets with good and comparable results.
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Discipline for Students with Disabilities in the Recovery School District (RSD) of New Orleans
Jeffers, Elizabeth K.
2014-01-01
This article focuses on special education in New Orleans post Hurricane Katrina. After Hurricane Katrina, Louisiana's Recovery School District (RSD) took over 102 of the city's 128 schools with the stated goal of creating a "choice district" for parents. This "choice distric"' is made up of RSD direct-run schools, Orleans…
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Ring-Sheared Drop (RSD): Microgravity Module for Containerless Flow Studies
Gulati, Shreyash; Raghunandan, Aditya; Rasheed, Fayaz; McBride, Samantha A.; Hirsa, Amir H.
2017-02-01
Microgravity is potentially a powerful tool for investigating processes that are sensitive to the presence of solid walls, since fluid containment can be achieved by surface tension. One such process is the transformation of protein in solution into amyloid fibrils; these are protein aggregates associated with neurodegenerative diseases such as Alzheimer's and Parkinson's. In addition to solid walls, experiments with gravity are also subject to influences from sedimentation of aggregates and buoyancy-driven convection. The ring-sheared drop (RSD) module is a flow apparatus currently under development to study formation of amyloid fibrils aboard the International Space Station (ISS). A 25 mm diameter drop of protein solution will be contained by surface tension and constrained by a pair of sharp-edged tubes, forming two contact rings. Shear can be imparted by rotating one ring with the other ring kept stationary. Here we report on parabolic flights conducted to test the growth and pinning of 10 mm diameter drops of water in under 10 s of microgravity. Finite element method (FEM) based fluid dynamics computations using a commercial package (COMSOL) assisted in the design of the parabolic flight experiments. Prior to the parabolic flights, the code was validated against experiments in the lab (1 g), on the growth of sessile and pendant droplets. The simulations show good agreement with the experiments. This modeling capability will enable the development of the RSD at the 25 mm scale for the ISS.
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Comparation studies of uranium analysis method using spectrophotometer and voltammeter
International Nuclear Information System (INIS)
Sugeng Pomomo
2013-01-01
Comparation studies of uranium analysis method by spectrophotometer and voltammeter had been done. The objective of experiment is to examine the reliability of analysis method and instrument performance by evaluate parameters; linearity, accuracy, precision and detection limit. Uranyl nitrate hexahydrate is used as standard, and the sample is solvent mixture of tributyl phosphate and kerosene containing uranium (from phosphoric acid purification unit Petrokimia Gresik). Uranium (U) stripping in the sample use HN0 3 0,5 N and then was analyzed by using of both instrument. Analysis of standard show that both methods give a good linearity by correlation coefficient > 0,999. Spectrophotometry give accuration 99,34 - 101,05 % with ratio standard deviation (RSD) 1,03 %; detection limit (DL) 0,05 ppm. Voltammetry give accuration 95,63 -101,49 % with RSD 3,91 %; detection limit (DL) 0,509 ppm. On the analysis of sludge samples were given the significantly different in result; spectrophotometry give U concentration 4,445 ppm by RSD 6,74 % and voltammetry give U concentration 7,693 by RSD 19,53%. (author)
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Introduction to precise numerical methods
Aberth, Oliver
2007-01-01
Precise numerical analysis may be defined as the study of computer methods for solving mathematical problems either exactly or to prescribed accuracy. This book explains how precise numerical analysis is constructed. The book also provides exercises which illustrate points from the text and references for the methods presented. All disc-based content for this title is now available on the Web. · Clearer, simpler descriptions and explanations ofthe various numerical methods· Two new types of numerical problems; accurately solving partial differential equations with the included software and computing line integrals in the complex plane.
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de Andrade, Jucimara Kulek; de Andrade, Camila Kulek; Komatsu, Emy; Perreault, Hélène; Torres, Yohandra Reyes; da Rosa, Marcos Roberto; Felsner, Maria Lurdes
2017-08-01
Corn syrups, important ingredients used in food and beverage industries, often contain high levels of 5-hydroxymethyl-2-furfural (HMF), a toxic contaminant. In this work, an in house validation of a difference spectrophotometric method for HMF analysis in corn syrups was developed using sophisticated statistical tools by the first time. The methodology showed excellent analytical performance with good selectivity, linearity (R 2 =99.9%, r>0.99), accuracy and low limits (LOD=0.10mgL -1 and LOQ=0.34mgL -1 ). An excellent precision was confirmed by repeatability (RSD (%)=0.30) and intermediate precision (RSD (%)=0.36) estimates and by Horrat value (0.07). A detailed study of method precision using a nested design demonstrated that variation sources such as instruments, operators and time did not interfere in the variability of results within laboratory and consequently in its intermediate precision. The developed method is environmentally friendly, fast, cheap and easy to implement resulting in an attractive alternative for corn syrups quality control in industries and official laboratories. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Subdomain Precise Integration Method for Periodic Structures
Directory of Open Access Journals (Sweden)
F. Wu
2014-01-01
Full Text Available A subdomain precise integration method is developed for the dynamical responses of periodic structures comprising many identical structural cells. The proposed method is based on the precise integration method, the subdomain scheme, and the repeatability of the periodic structures. In the proposed method, each structural cell is seen as a super element that is solved using the precise integration method, considering the repeatability of the structural cells. The computational efforts and the memory size of the proposed method are reduced, while high computational accuracy is achieved. Therefore, the proposed method is particularly suitable to solve the dynamical responses of periodic structures. Two numerical examples are presented to demonstrate the accuracy and efficiency of the proposed method through comparison with the Newmark and Runge-Kutta methods.
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Shurbaji, Maher; Abu Al Rub, Mohamad H; Saket, Munib M; Qaisi, Ali M; Salim, Maher L; Abu-Nameh, Eyad S M
2010-01-01
A rapid, simple, and sensitive RP-HPLC analytical method was developed for the simultaneous determination of triclabendazole and ivermectin in combination using a C18 RP column. The mobile phase was acetonitrile-methanol-water-acetic acid (56 + 36 + 7.5 + 0.5, v/v/v/v) at a pH of 4.35 and flow rate of 1.0 mL/min. A 245 nm UV detection wavelength was used. Complete validation, including linearity, accuracy, recovery, LOD, LOQ, precision, robustness, stability, and peak purity, was performed. The calibration curve was linear over the range 50.09-150.26 microg/mL for triclabendazole with r = 0.9999 and 27.01-81.02 microg/mL for ivermectin with r = 0.9999. Calculated LOD and LOQ for triclabendazole were 0.03 and 0.08 microg/mL, respectively, and for ivermectin 0.07 and 0.20 microg/mL, respectively. The intraday precision obtained was 98.71% with RSD of 0.87% for triclabendazole and 100.79% with RSD 0.73% for ivermectin. The interday precision obtained was 99.51% with RSD of 0.35% for triclabendazole and 100.55% with RSD of 0.59% for ivermectin. Robustness was also studied, and there was no significant variation of the system suitability of the analytical method with small changes in experimental parameters.
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Pascale, Raffaella; Caivano, Marianna; Buchicchio, Alessandro; Mancini, Ignazio M; Bianco, Giuliana; Caniani, Donatella
2017-01-13
Wastewater treatment plants (WWTPs) emit CO 2 and N 2 O, which may lead to climate change and global warming. Over the last few years, awareness of greenhouse gas (GHG) emissions from WWTPs has increased. Moreover, the development of valid, reliable, and high-throughput analytical methods for simultaneous gas analysis is an essential requirement for environmental applications. In the present study, an analytical method based on a gas chromatograph (GC) equipped with a barrier ionization discharge (BID) detector was developed for the first time. This new method simultaneously analyses CO 2 and N 2 O and has a precision, measured in terms of relative standard of variation RSD%, equal to or less than 6.6% and 5.1%, respectively. The method's detection limits are 5.3ppm v for CO 2 and 62.0ppb v for N 2 O. The method's selectivity, linearity, accuracy, repeatability, intermediate precision, limit of detection and limit of quantification were good at trace concentration levels. After validation, the method was applied to a real case of N 2 O and CO 2 emissions from a WWTP, confirming its suitability as a standard procedure for simultaneous GHG analysis in environmental samples containing CO 2 levels less than 12,000mg/L. Copyright © 2016 Elsevier B.V. All rights reserved.
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Development and validation of an LC-UV method for the determination of sulfonamides in animal feeds.
Kumar, P; Companyó, R
2012-05-01
A simple LC-UV method was developed for the determination of residues of eight sulfonamides (sulfachloropyridazine, sulfadiazine, sulfadimidine, sulfadoxine, sulfamethoxypyridazine, sulfaquinoxaline, sulfamethoxazole, and sulfadimethoxine) in six types of animal feed. C18, Oasis HLB, Plexa and Plexa PCX stationary phases were assessed for the clean-up step and the latter was chosen as it showed greater efficiency in the clean-up of interferences. Feed samples spiked with sulfonamides at 2 mg/kg were used to assess the trueness (recovery %) and precision of the method. Mean recovery values ranged from 47% to 66%, intra-day precision (RSD %) from 4% to 15% and inter-day precision (RSD %) from 7% to 18% in pig feed. Recoveries and intra-day precisions were also evaluated in rabbit, hen, cow, chicken and piglet feed matrices. Calibration curves with standards prepared in mobile phase and matrix-matched calibration curves were compared and the matrix effects were ascertained. The limits of detection and quantification in the feeds ranged from 74 to 265 µg/kg and from 265 to 868 µg/kg, respectively. Copyright © 2011 John Wiley & Sons, Ltd.
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Ducher, J-L; Daléry, J
2004-01-01
The prevention of suicide is a top priority in mental health. The determination of high risk suicidal groups is not sufficient. The expressing suicidal ideas is not a protective factor, but in contrary a risk factor to take into account, or even to search and to quantify: 80% of the subjects who attempt to commit suicide or commit suicide express such ideas months before. Several evaluation instruments try to help the practitioners or the research workers in this reasoning. The suicidal risk assessment scale RSD can be cited in particular. It is composed of eleven sections. The 0 level corresponds to the absence of particular ideas of death or suicide. Levels 1 and 2, the presence of ideas of death. Levels 3-4-5, the presence of suicidal ideas. The difference compared to the majority of the other scales consecrated to the same subject, the passif desire of death, occupies a place totally particular in the RSD (level 6). From the level 7, the risk of acting out seems to become more important. It stops being a simple idea of suicide, but becomes a real will of dying, firstly retained by something or someone (level 7), the fear of causing suffering to dear ones or a religious belief., then determined (level 8). Finally, the patient has elaborated a concrete plan (level 9) or he has already started the preparation of acting out (level 10). It is just necessary to evaluate and to note the highest level of the scale. The inclusion of the suicidal risk assessment scale RSD and of the Suicidal Ideation Scale by Beck in an international multicenters, phase IV, double-blind study, according to two parallel groups, with a fixed dose of fluoxétine or fluvoxamine for six weeks, allowed to search correlations which could exist between the two scales. The ana-lysis before the beginning of the treatment was done on 108 outpatients depressive, male and female, aged 18 or over. It finds a satisfactory concurrent validity between the suicidal risk assessment scale RSD and the
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Method validation for uranium content analysis using a potentiometer T-90
International Nuclear Information System (INIS)
Torowati; Ngatijo; Rahmiati
2016-01-01
An experimental method validation has been conducted for uranium content analysis using Potentiometer T-90. The method validation experiment was performed in the quality control laboratory of Experiment Fuel Element Installation, PTBBN - BATAN. The objective is to determine the level of precision and accuracy of analytical results for uranium analysis referring to the latest American Standard Test Method (ASTM) of ASTM C1267-11, which is a modified reference method by reducing of reagent consumption by 10% of the amount used by the original method. The ASTM C 1267-11 reference is a new ASTM as a substitute for the older ASTM namely ASTM C799, Vol.12.01, 2003. It is, therefore, necessary to validate the renewed method. The tool used for the analysis of uranium was potentiometer T-90 and the material used was standard uranium oxide powder CRM (Certificate Reference Material). Validation of the method was done by analyzing standard uranium powder by 7 times weighing and 7 times analysis. Analysis results were used to determine the level of accuracy, precision, Relative Standard Deviation (RSD) and Horwitz coefficient Variation and limit detection and quantitation. The average uranium obtained for this method validation is 84.36% with Standard Deviation (SD) of 0.12%, Relative Standard Deviation (RSD) 0.14% and 2/3 Horwitz coefficient Variation (CV Horwitz) 2.05%. The results show that RSD value is smaller than the value of (2/3) CV Horwitz, which means that this method has a high precision. The accuracy value obtained is 0.48%, and since the acceptance limit of high level of accuracy is when the accuracy value is <2.00%, this method is regarded as having a high degree of accuracy [1]. The limit of detection (LOD) and and the limit of quantitation (LOQ) are 0.0145 g/L and 0.0446 g/L respectively. It is concluded that the ASTM C 1267-11 reference method is valid for use. (author)
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Naveen, P; Lingaraju, H B; Deepak, M; Medhini, B; Prasad, K Shyam
2018-01-01
The present study was investigated to develop and validate a reversed phase high performance liquid chromatography method for the determination of caffeine from bean material of Coffee arabica. The separation was achieved on a reversed-phase C18 column using a mobile phase composed of water: methanol (50:50) at a flow rate of 1.0 mlmin-1. The detection was carried out on a UV detector at 272 nm. The developed method was validated according to the requirements for International Conference on Harmonisation (ICH) guidelines, which includes specificity, linearity, precision, accuracy, limit of detection and limit of quantitation. The developed method validates good linearity with excellent correlation coefficient (R2 > 0.999). In repeatability and intermediate precision, the percentage relative standard deviation (% RSD) of peak area was less than 1% shows high precision of the method. The recovery rate for caffeine was within 98.78% - 101.28% indicates high accuracy of the method. The low limit of detection and limit of quantitation of caffeine enable the detection and quantitation of caffeine from C. arabica at low concentrations. The developed HPLC method is a simple, rapid, precisely, accurately and widely accepted and it is recommended for efficient assays in routine work. A simple, accurate, and sensitive high-performance liquid chromatography (HPLC) method for caffeine from Coffea arabica has been developed and validated. The developed HPLC method was validated for linearity, specificity, precision, recovery, limits of detection, and limits of quantification by the International Conference on Harmonization guidelines. The results revealed that the proposed method is highly reliable. This method could be successfully applied for routine quality work analysis. Abbreviation Used: C. arabica : Coffee arabica, ICH: International Conference on Harmonisation, % RSD: Percentage Relative Standard Deviation, R2: Correlation Coefficient, ppm: Parts per million, LOD: Limits
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Analysis of Precision of Activation Analysis Method
DEFF Research Database (Denmark)
Heydorn, Kaj; Nørgaard, K.
1973-01-01
The precision of an activation-analysis method prescribes the estimation of the precision of a single analytical result. The adequacy of these estimates to account for the observed variation between duplicate results from the analysis of different samples and materials, is tested by the statistic T...
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Hopkins, D L; Safari, E; Thompson, J M; Smith, C R
2004-06-01
A wide selection of lamb types of mixed sex (ewes and wethers) were slaughtered at a commercial abattoir and during this process images of 360 carcasses were obtained online using the VIAScan® system developed by Meat and Livestock Australia. Soft tissue depth at the GR site (thickness of tissue over the 12th rib 110 mm from the midline) was measured by an abattoir employee using the AUS-MEAT sheep probe (PGR). Another measure of this thickness was taken in the chiller using a GR knife (NGR). Each carcass was subsequently broken down to a range of trimmed boneless retail cuts and the lean meat yield determined. The current industry model for predicting meat yield uses hot carcass weight (HCW) and tissue depth at the GR site. A low level of accuracy and precision was found when HCW and PGR were used to predict lean meat yield (R(2)=0.19, r.s.d.=2.80%), which could be improved markedly when PGR was replaced by NGR (R(2)=0.41, r.s.d.=2.39%). If the GR measures were replaced by 8 VIAScan® measures then greater prediction accuracy could be achieved (R(2)=0.52, r.s.d.=2.17%). A similar result was achieved when the model was based on principal components (PCs) computed from the 8 VIAScan® measures (R(2)=0.52, r.s.d.=2.17%). The use of PCs also improved the stability of the model compared to a regression model based on HCW and NGR. The transportability of the models was tested by randomly dividing the data set and comparing coefficients and the level of accuracy and precision. Those models based on PCs were superior to those based on regression. It is demonstrated that with the appropriate modeling the VIAScan® system offers a workable method for predicting lean meat yield automatically.
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Energy Technology Data Exchange (ETDEWEB)
Araujo, Henrique Peres; Felix, Juliana Silva [Department of Food and Nutrition, School of Pharmaceutical Science, Sao Paulo State University, PO Box 502, 14801-902 Araraquara, SP (Brazil); Manzoli, Jose Eduardo [Nuclear and Energetic Research Institute (IPEN), Sao Paulo, SP (Brazil); Padula, Marisa [Packaging Technology Center/Food Technology Institute (CETEA/ITAL), Campinas, SP (Brazil); Monteiro, Magali [Department of Food and Nutrition, School of Pharmaceutical Science, Sao Paulo State University, PO Box 502, 14801-902 Araraquara, SP (Brazil)], E-mail: monteiro@fcfar.unesp.br
2008-07-15
A gas chromatographic method to determine caprolactam in multilayer PA-6 films used for meat foodstuffs and cheese was developed and validated. A wide linear range (0.8-400 {mu}g/ml), RSD{<=}4.1% and recovery higher than 90.0% were obtained for the chromatographic system, while precision and accuracy of the method showed RSD{<=}3.8%, recovery from 95.5-100.0% and LOQ of 32 {mu}g/g. Irradiated (3, 7 and 12 kGy) and non-irradiated commercial films were analyzed. Most of them increased caprolactam levels with the increase of irradiation doses.
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Gravimetric method for the determination of diclofenac in pharmaceutical preparations.
Tubino, Matthieu; De Souza, Rafael L
2005-01-01
A gravimetric method for the determination of diclofenac in pharmaceutical preparations was developed. Diclofenac is precipitated from aqueous solution with copper(II) acetate in pH 5.3 (acetic acid/acetate buffer). Sample aliquots had approximately the same quantity of the drug content in tablets (50 mg) or in ampules (75 mg). The observed standard deviation was about +/- 2 mg; therefore, the relative standard deviation (RSD) was approximately 4% for tablet and 3% for ampule preparations. The results were compared with those obtained with the liquid chromatography method recommended in the United States Pharmacopoeia using the statistical Student's t-test. Complete agreement was observed. It is possible to obtain more precise results using higher aliquots, for example 200 mg, in which case the RSD falls to 1%. This gravimetric method, contrary to what is expected for this kind of procedure, is relatively fast and simple to perform. The main advantage is the absolute character of the gravimetric analysis.
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Reference satellite selection method for GNSS high-precision relative positioning
Directory of Open Access Journals (Sweden)
Xiao Gao
2017-03-01
Full Text Available Selecting the optimal reference satellite is an important component of high-precision relative positioning because the reference satellite directly influences the strength of the normal equation. The reference satellite selection methods based on elevation and positional dilution of precision (PDOP value were compared. Results show that all the above methods cannot select the optimal reference satellite. We introduce condition number of the design matrix in the reference satellite selection method to improve structure of the normal equation, because condition number can indicate the ill condition of the normal equation. The experimental results show that the new method can improve positioning accuracy and reliability in precise relative positioning.
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Integrative methods for analyzing big data in precision medicine.
Gligorijević, Vladimir; Malod-Dognin, Noël; Pržulj, Nataša
2016-03-01
We provide an overview of recent developments in big data analyses in the context of precision medicine and health informatics. With the advance in technologies capturing molecular and medical data, we entered the area of "Big Data" in biology and medicine. These data offer many opportunities to advance precision medicine. We outline key challenges in precision medicine and present recent advances in data integration-based methods to uncover personalized information from big data produced by various omics studies. We survey recent integrative methods for disease subtyping, biomarkers discovery, and drug repurposing, and list the tools that are available to domain scientists. Given the ever-growing nature of these big data, we highlight key issues that big data integration methods will face. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Precision die design by the die expansion method
Ibhadode, A O Akii
2009-01-01
This book presents a new method for the design of the precision dies used in cold-forging, extrusion and drawing processes. The method is based upon die expansion, and attempts to provide a clear-cut theoretical basis for the selection of critical die dimensions for this group of precision dies when the tolerance on product diameter (or thickness) is specified. It also presents a procedure for selecting the minimum-production-cost die from among a set of design alternatives. The mathematical content of the book is relatively simple and will present no difficulty to those who have taken basic c
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Directory of Open Access Journals (Sweden)
LIU Weiping
2016-02-01
Full Text Available To resolve the high relativity between the transverse element of GEO orbit and double-difference ambiguity, the classical double-difference dynamic method is improved and the method, which is to determine precise BeiDou satellite orbit using carrier phase and pseudo-range smoothed by phase, is proposed. The feasibility of the method is discussed and the influence of the method about ambiguity fixing is analyzed. Considering the characteristic of BeiDou, the method, which is to fix double-difference ambiguity of BeiDou satellites by QIF, is derived. The real data analysis shows that the new method, which can reduce the relativity and assure the precision, is better than the classical double-difference dynamic method. The result of ambiguity fixing is well by QIF, but the ambiguity fixing success rate is not high on the whole. So the precision of BeiDou orbit can't be improved clearly after ambiguity fixing.
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Method of high precision interval measurement in pulse laser ranging system
Wang, Zhen; Lv, Xin-yuan; Mao, Jin-jin; Liu, Wei; Yang, Dong
2013-09-01
Laser ranging is suitable for laser system, for it has the advantage of high measuring precision, fast measuring speed,no cooperative targets and strong resistance to electromagnetic interference,the measuremen of laser ranging is the key paremeters affecting the performance of the whole system.The precision of the pulsed laser ranging system was decided by the precision of the time interval measurement, the principle structure of laser ranging system was introduced, and a method of high precision time interval measurement in pulse laser ranging system was established in this paper.Based on the analysis of the factors which affected the precision of range measure,the pulse rising edges discriminator was adopted to produce timing mark for the start-stop time discrimination,and the TDC-GP2 high precision interval measurement system based on TMS320F2812 DSP was designed to improve the measurement precision.Experimental results indicate that the time interval measurement method in this paper can obtain higher range accuracy. Compared with the traditional time interval measurement system,the method simplifies the system design and reduce the influence of bad weather conditions,furthermore,it satisfies the requirements of low costs and miniaturization.
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Directory of Open Access Journals (Sweden)
Layzon Antonio Lemos da Silva
Full Text Available AbstractVernonanthura tweedieana (Baker H. Rob., Asteraceae, is used in the Brazilian folk medicine for the treatment of respiratory diseases. In this work the phytochemical investigation of its ethanol extracts as well as the development and validation of an UPLC-PDA method for the quantification of the eriodictyol from the leaves were performed. The phytochemical study for this species lead to the identification of ethyl caffeate, naringenin and chrysoeriol in mixture, eriodictyol from leaves, and the mixture of 3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl-propan-1-one and evofolin B, apigenin, the mixture of caffeic and protocatechuic acid and luteolin from stems with roots, being reported for the first time for V. tweedieana, except for eriodictyol. The structural elucidation of all isolated compounds was achieved by 1H and 2D NMR spectroscopy, and in comparison with published data. An UPLC-PDA method for quantification of the eriodictyol in leaves of V. tweedieana was developed and validated for specificity, linearity, precision (repeatability and intermediate precision, limit of detection (LOD and limit of quantification (LOQ, accuracy and robustness. In this study, an excellent linearity was obtained (r2 = 0.9999, good precision (repeatability RSD = 2% and intermediate precision RSD = 8% and accuracy (average recovery from 98.6% to 99.7%. The content of eriodictyol in the extract of leaves of V. tweedieana was 41.40 ± 0.13 mg/g. Thus, this study allowed the optimization of a simple, fast and validated UPLC-PDA method which can be used to support the quality assessment of this herbal material.
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Directory of Open Access Journals (Sweden)
Srinivas Vishnumulaka
2008-01-01
Full Text Available A rapid and sensitive RP-HPLC method with UV detection (242 nm for routine analysis of famciclovir in pharmaceutical formulations was developed. Chromatography was performed with mobile phase containing a mixture of methanol and phosphate buffer (50:50, v/v with flow rate 1.0 mL min−1. Quantitation was accomplished with internal standard method. The procedure was validated for linearity (correlation coefficient =0.9999, accuracy, robustness and intermediate precision. Experimental design was used for validation of robustness and intermediate precision. To test robustness, three factors were considered; percentage v/v of methanol in mobile phase, flow rate and pH; flow rate, the percentage of organic modifier and pH have considerable important effect on the response. For intermediate precision measure the variables considered were: analyst, equipment and number of days. The RSD value (0.86%, n=24 indicated an acceptable precision of the analytical method. The proposed method was simple, sensitive, precise, accurate and quick and useful for routine quality control.
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Validated method for the analysis of goji berry, a rich source of zeaxanthin dipalmitate.
Karioti, Anastasia; Bergonzi, Maria Camilla; Vincieri, Franco F; Bilia, Anna Rita
2014-12-31
In the present study an HPLC-DAD method was developed for the determination of the main carotenoid, zeaxanthin dipalmitate, in the fruits of Lycium barbarum. The aim was to develop and optimize an extraction protocol to allow fast, exhaustive, and repeatable extraction, suitable for labile carotenoid content. Use of liquid N2 allowed the grinding of the fruit. A step of ultrasonication with water removed efficiently the polysaccharides and enabled the exhaustive extraction of carotenoids by hexane/acetone 50:50. The assay was fast and simple and permitted the quality control of a large number of commercial samples including fruits, juices, and a jam. The HPLC method was validated according to ICH guidelines and satisfied the requirements. Finally, the overall method was validated for precision (% RSD ranging between 3.81 and 4.13) and accuracy at three concentration levels. The recovery was between 94 and 107% with RSD values <2%, within the acceptable limits, especially if the difficulty of the matrix is taken into consideration.
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Directory of Open Access Journals (Sweden)
Andrea Pacheco Pacífico
2013-01-01
Full Text Available This article recommends a new way to improve Refugee Status Determination (RSD procedures by proposing a network society communicative model based on active involvement and dialogue among all implementing partners. This model, named after proposals from Castells, Habermas, Apel, Chimni, and Betts, would be mediated by the United Nations High Commissioner for Refugees (UNHCR, whose role would be modeled after that of the International Committee of the Red Cross (ICRC practice.
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HPLC method validation for modernization of the tetracycline hydrochloride capsule USP monograph
Directory of Open Access Journals (Sweden)
Emad M. Hussien
2014-12-01
Full Text Available This paper is a continuation to our previous work aiming at development and validation of a reversed-phase HPLC for modernization of tetracycline-related USP monographs and the USP general chapter . Previous results showed that the method is accurate and precise for the assay of tetracycline hydrochloride and the limit of 4-epianhydrotetracycline impurity in the drug substance and oral suspension monographs. The aim of the current paper is to examine the feasibility of the method for modernization of USP tetracycline hydrochloride capsule monograph. Specificity, linearity, accuracy and precision were examined for tetracycline hydrochloride assay and 4-epianhydrotetracycline limit. The method was linear in the concentration range from 80% to 160% (r>0.9998 of the assay concentration (0.1 mg/mL for tetracycline hydrochloride and from 50% to 150% (r>0.997 of the acceptance criteria specified in tetracycline hydrochloride capsule monograph for 4-epianhydrotetracycline (NMT 3.0%. The recovery at three concentration levels for tetracycline hydrochloride assay was between 99% and 101% and the RSD from six preparations at the concentration 0.1 mg/mL is less than 0.6%. The recovery for 4-epianhydrotetracycline limit procedure over the concentration range from 50% to 150% is between 96% and 102% with RSD less than 5%. The results met the specified acceptance criteria.
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Precision profiles and analytic reliability of radioimmunologic methods
International Nuclear Information System (INIS)
Yaneva, Z.; Popova, Yu.
1991-01-01
The aim of the present study is to investigate and compare some methods for creation of 'precision profiles' (PP) and to clarify their possibilities for determining the analytical reliability of RIA. Only methods without complicated mathematical calculations has been used. The reproducibility in serums with a concentration of the determinable hormone in the whole range of the calibration curve has been studied. The radioimmunoassay has been performed with TSH-RIA set (ex East Germany), and comparative evaluations - with commercial sets of HOECHST (Germany) and AMERSHAM (GB). Three methods for obtaining the relationship concentration (IU/l) -reproducibility (C.V.,%) are used and a comparison is made of their corresponding profiles: preliminary rough profile, Rodbard-PP and Ekins-PP. It is concluded that the creation of a precision profile is obligatory and the method of its construction does not influence the relationship's course. PP allows to determine concentration range giving stable results which improves the efficiency of the analitical work. 16 refs., 4 figs
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Directory of Open Access Journals (Sweden)
Gurinder Singh
2012-01-01
Full Text Available A simple, accurate, precise, sensitive, and reproducible high-performance liquid chromatography method was developed for the determination of Resveratrol (trans-3, 4΄,5-trihydroxystilbene in human plasma using liquid-liquid extraction. Caffeine was employed as an internal standard (IS. However, little information is known about its distribution in the organism generally because of the lack of accurate and precise detection methods. The chromatographic separation was achieved on a Phenomenex C18 column (250 mm × 4.6 mm, 5 μm at room temperature in isocratic mode, and the column effluent was monitored by UV detector at 306 nm. The mobile phase used was methanol: phosphate buffer (pH 6.8 adjusted with 0.5% (v/v orthophosphoric acid solution in Milli-Q water (63:37%, v/v at a flow rate of 1.0 ml/min. Nominal retention times of trans-resveratrol and IS were 3.94 and 7.86 minutes, respectively. Limits of detection and Limits of quantification of trans-resveratrol were 0.006 μg/ml and 0.008 μg/ml, respectively. This method was linear over the range of 0.010 to 6.4 μg/ml with regression coefficient greater than 0.9998. The inter- and intra-day precisions in the samples, 0.010, 3.2 and 6.4 μg/ml of trans-resveratrol was in the range 0.63 to 2.12% relative standard deviation (RSD and 0.46 to 1.02% RSD, respectively. Resveratrol was found to be stable for a period of 15 days on storage at -20°C. The method was found to be precise, accurate, and specific during the study.
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International Nuclear Information System (INIS)
Pereira, Elaine
2016-01-01
This work presents a low cost, simple and new methodology for direct quantification of uranium in compounds of the nuclear fuel cycle, based on Fourier Transform Infrared (FTIR) spectroscopy using KBr pressed discs technique. Uranium in different matrices were used to development and validation: UO 2 (NO 3 )2.2TBP complex (TBP uranyl nitrate complex) in organic phase and uranyl nitrate (UO 2 (NO 3 ) 2 ) in aqueous phase. The parameters used in the validation process were: linearity, selectivity, accuracy, limits of detection (LD) and quantitation (LQ), precision (repeatability and intermediate precision) and robustness. The method for uranium in organic phase (UO 2 (NO 3 )2.2TBP complex in hexane/embedded in KBr) was linear (r = 0.9980) over the range of 0.20% 2.85% U/ KBr disc, LD 0.02% and LQ 0.03%, accurate (recoveries were over 101.0%), robust and precise (RSD < 1.6%). The method for uranium aqueous phase (UO 2 (NO 3 ) 2 /embedded in KBr) was linear (r = 0.9900) over the range of 0.14% 1.29% U/KBr disc, LD 0.01% and LQ 0.02%, accurate (recoveries were over 99.4%), robust and precise (RSD < 1.6%). Some process samples were analyzed in FTIR and compared with gravimetric and X-ray fluorescence (XRF) analyses showing similar results in all three methods. The statistical tests (t-Student and Fischer) showed that the techniques are equivalent. The validated method can be successfully employed for routine quality control analysis for nuclear compounds. (author)
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DEFF Research Database (Denmark)
Weeke, Peter; Andersson, Charlotte; Brendorp, Bente
2008-01-01
Vernakalant (RSD1235) is a novel antiarrhythmic agent for conversion of rapid onset atrial fibrillation (AF). It is an atria-selective multichannel ion blocker (blocks I(Kur), I(Na), I(Ca, L), I(to) and I(Kr)), with a small effect on ventricular repolarization. In clinical Phase II and III studie...... effect, with no reported cases of torsades de pointes in direct relation to vernakalant administration in Phase II and III studies. Overall, there are few reported serious adverse events.......Vernakalant (RSD1235) is a novel antiarrhythmic agent for conversion of rapid onset atrial fibrillation (AF). It is an atria-selective multichannel ion blocker (blocks I(Kur), I(Na), I(Ca, L), I(to) and I(Kr)), with a small effect on ventricular repolarization. In clinical Phase II and III studies...
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Alonso-Salces, Rosa M; Barranco, Alejandro; Corta, Edurne; Berrueta, Luis A; Gallo, Blanca; Vicente, Francisca
2005-02-15
A solid-liquid extraction procedure followed by reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with a photodiode array detector (DAD) for the determination of polyphenols in freeze-dried apple peel and pulp is reported. The extraction step consists in sonicating 0.5g of freeze-dried apple tissue with 30mL of methanol-water-acetic acid (30:69:1, v/v/v) containing 2g of ascorbic acid/L, for 10min in an ultrasonic bath. The whole method was validated, concluding that it is a robust method that presents high extraction efficiencies (peel: >91%, pulp: >95%) and appropriate precisions (within day: R.S.D. (n = 5) <5%, and between days: R.S.D. (n = 5) <7%) at the different concentration levels of polyphenols that can be found in apple samples. The method was compared with one previously published, consisting in a pressurized liquid extraction (PLE) followed by RP-HPLC-DAD determination. The advantages and disadvantages of both methods are discussed.
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Suzuki, Ippei; Kubota, Hiroki; Ohtsuki, Takashi; Tatebe, Chiye; Tada, Atsuko; Yano, Takeo; Akiyama, Hiroshi; Sato, Kyoko
2016-01-01
A rapid, sensitive, and specific analytical method for the determination of 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) on uncooked foods after treatment with a peracetic acid-based sanitizer (PAS) was developed. The method involves simple sample preparation steps and analysis using ion chromatography (IC) coupled with tandem mass spectrometry (MS/MS). The quantification limits of HEDP on uncooked foods are 0.007 mg/kg for vegetables and fruits and 0.2 mg/kg for meats. The recovery and relative standard deviation (RSD) of HEDP analyses of uncooked foods ranged from 73.9 to 103.8% and 1.9 to 12.6%, respectively. The method's accuracy and precision were evaluated by inter-day recovery tests. The recovery for all samples ranged from 93.6 to 101.2%, and the within-laboratory repeatability and reproducibility were evaluated based on RSD values, which were less than 6.9 and 11.5%, respectively. Analyses of PAS-treated fruits and vegetables using the developed method indicated levels of HEDP ranging from 0.008 to 0.351 mg/kg. Therefore, the results of the present study suggest that the proposed method is an accurate, precise, and reliable way to determine residual HEDP levels on PAS-treated uncooked foods.
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Hariri, Nadjla; Ravandi, Somayyeh Nadi
2014-01-01
Medline is one of the most important databases in the biomedical field. One of the most important hosts for Medline is Elton B. Stephens CO. (EBSCO), which has presented different search methods that can be used based on the needs of the users. Visual search and MeSH-controlled search methods are among the most common methods. The goal of this research was to compare the precision of the retrieved sources in the EBSCO Medline base using MeSH-controlled and visual search methods. This research was a semi-empirical study. By holding training workshops, 70 students of higher education in different educational departments of Kashan University of Medical Sciences were taught MeSH-Controlled and visual search methods in 2012. Then, the precision of 300 searches made by these students was calculated based on Best Precision, Useful Precision, and Objective Precision formulas and analyzed in SPSS software using the independent sample T Test, and three precisions obtained with the three precision formulas were studied for the two search methods. The mean precision of the visual method was greater than that of the MeSH-Controlled search for all three types of precision, i.e. Best Precision, Useful Precision, and Objective Precision, and their mean precisions were significantly different (P searches. Fifty-three percent of the participants in the research also mentioned that the use of the combination of the two methods produced better results. For users, it is more appropriate to use a natural, language-based method, such as the visual method, in the EBSCO Medline host than to use the controlled method, which requires users to use special keywords. The potential reason for their preference was that the visual method allowed them more freedom of action.
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Modi, Ketan Pravinbhai; Patel, Natvarlal Manilal; Goyal, Ramesh Kishorilal
2008-03-01
A selective, precise, and accurate high-performance thin-layer chromatographic (HPTLC) method has been developed for the analysis of L-dopa in Mucuna pruriens seed extract and its formulations. The method involves densitometric evaluation of L-dopa after resolving it by HPTLC on silica gel plates with n-butanol-acetic acid-water (4.0+1.0+1.0, v/v) as the mobile phase. Densitometric analysis of L-dopa was carried out in the absorbance mode at 280 nm. The relationship between the concentration of L-dopa and corresponding peak areas was found to be linear in the range of 100 to 1200 ng/spot. The method was validated for precision (inter and intraday), repeatability, and accuracy. Mean recovery was 100.30%. The relative standard deviation (RSD) values of the precision were found to be in the range 0.64-1.52%. In conclusion, the proposed TLC method was found to be precise, specific and accurate and can be used for identification and quantitative determination of L-dopa in herbal extract and its formulations.
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Verification of spectrophotometric method for nitrate analysis in water samples
Kurniawati, Puji; Gusrianti, Reny; Dwisiwi, Bledug Bernanti; Purbaningtias, Tri Esti; Wiyantoko, Bayu
2017-12-01
The aim of this research was to verify the spectrophotometric method to analyze nitrate in water samples using APHA 2012 Section 4500 NO3-B method. The verification parameters used were: linearity, method detection limit, level of quantitation, level of linearity, accuracy and precision. Linearity was obtained by using 0 to 50 mg/L nitrate standard solution and the correlation coefficient of standard calibration linear regression equation was 0.9981. The method detection limit (MDL) was defined as 0,1294 mg/L and limit of quantitation (LOQ) was 0,4117 mg/L. The result of a level of linearity (LOL) was 50 mg/L and nitrate concentration 10 to 50 mg/L was linear with a level of confidence was 99%. The accuracy was determined through recovery value was 109.1907%. The precision value was observed using % relative standard deviation (%RSD) from repeatability and its result was 1.0886%. The tested performance criteria showed that the methodology was verified under the laboratory conditions.
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Validation of an HPLC method for the simultaneous determination of eletriptan and UK 120.413
Directory of Open Access Journals (Sweden)
LJILJANA ZIVANOVIC
2006-11-01
Full Text Available Arapid and sensitive RPHPLCmethod was developed for the routine control analysis of eletriptan hydrobromide and its organic impurity UK 120.413 in Relpax® tablets. The chromatography was performed at 20 °Cusing a C18 XTerraTM (5 m, 150 × 4,6 mm column at a flow rate 1.0 ml/min. The drug and its impurity were detected at 225 nm. The mobile phase consisted of TEA (1 % – methanol (67.2:32.8 v/v, the pH of which was adjusted to 6.8 with 85 % orthophosphoric acid. Quantification was accomplished by the internal standard method. The developed RP HPLC method was validated by testing: accuracy, precision, repeatibility, specificity, detection limit, quantification limit, linearity, robustness and sensitivity. High linearity of the analytical procedure was confirmed over the concentration range of 0.05 – 1.00 mg/ml for eletriptan hydrobromide and from 0.10 – 1.50 µg/ml for UK 120.413, with correlation coefficients greater than r = 0.995. The low value of the RSD expressed the good repeatability and precision of the method. Experimental design and a response surface method were used to test robustness of the analytical procedure and to evaluate the effect of variation of the method parameters, namely the mobile phase composition, pH and temperature. They showed small deviations from the method setting. The good recovery and low RSD confirm the suitability of the proposed RP HPLC method for the routine determination of eletriptan hydrobromide and its impurity UK 120.413 in Relpax® tables.
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Determination of cordycepin content of Cordyceps militaris ...
African Journals Online (AJOL)
Determination of cordycepin content of Cordyceps militaris recombinant rice by high performance liquid chromatography. ... Relative standard deviation (RSD), precision and repeatability RSD was 2.38, 0.76 and 1.46 %, respectively. Conclusion: The HPLC method is simple, fast, accurate and reproducible. It is suitable for ...
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Mezouari, S; Liu, W Yun; Pace, G; Hartman, T G
2015-01-01
The objective of this study was to develop an improved analytical method for the determination of 3-chloro-1,2-propanediol (3-MCPD) and 1,3-dichloropropanol (1,3-DCP) in paper-type food packaging. The established method includes aqueous extraction, matrix spiking of a deuterated surrogate internal standard (3-MCPD-d₅), clean-up using Extrelut solid-phase extraction, derivatisation using a silylation reagent, and GC-MS analysis of the chloropropanols as their corresponding trimethyl silyl ethers. The new method is applicable to food-grade packaging samples using European Commission standard aqueous extraction and aqueous food stimulant migration tests. In this improved method, the derivatisation procedure was optimised; the cost and time of the analysis were reduced by using 10 times less sample, solvents and reagents than in previously described methods. Overall the validation data demonstrate that the method is precise and reliable. The limit of detection (LOD) of the aqueous extract was 0.010 mg kg(-1) (w/w) for both 3-MCPD and 1,3-DCP. Analytical precision had a relative standard deviation (RSD) of 3.36% for 3-MCPD and an RSD of 7.65% for 1,3-DCP. The new method was satisfactorily applied to the analysis of over 100 commercial paperboard packaging samples. The data are being used to guide the product development of a next generation of wet-strength resins with reduced chloropropanol content, and also for risk assessments to calculate the virtual safe dose (VSD).
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Cliché fabrication method using precise roll printing process with 5 um pattern width
Shin, Yejin; Kim, Inyoung; Oh, Dong-Ho; Lee, Taik-Min
2016-09-01
Among the printing processes for printed electronic devices, gravure offset and reverse offset method have drawn attention for its fine pattern printing possibility. These printing methods use cliché, which has critical effect on the final product precision and quality. In this research, a novel precise cliché replica method is proposed. It consists of copper sputtering, precise mask pattern printing with 5 um width using reverse offset printing, Ni electroplating, lift-off, etching, and DLC coating. We finally compare the fabricated replica cliché with the original one and print out precise patterns using the replica cliché.
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Directory of Open Access Journals (Sweden)
Taízia Dutra Silva
2017-04-01
Full Text Available Sildenafil citrate (SILC is a potent phosphodiesterase-5 inhibitor used for erectile dysfunction and pulmonary hypertension. This study shows two simple, fast and alternative analytical methods for SILC determination by non-aqueous titration and by derivative ultraviolet spectrophotometry (DUS in active pharmaceutical ingredient and/or dosage forms. The quantitation method of SILC active pharmaceutical ingredient by non-aqueous acid-base titration was developed using methanol as solvent and 0.1 mol/L of perchloric acid in acetic acid as titrant. The endpoint was potentiometrically detected. The non-aqueous titration method shows satisfactory repeatability and intermediate precision (RSD 0.70-1.09%. The neutralization reaction occurred in the stoichiometric ratio 1:1 in methanol. The determination of SILC active pharmaceutical ingredient or dosage forms by DUS was developed in the linear range from 10 to 40 µg/mL, in 0.01 mol/L HCl, using the first order zero-peak method at λ 256 nm. The DUS method shows selectivity toward tablets excipients, appropriate linearity (R2 0.9996, trueness (recovery range 98.86-99.30%, repeatability and intermediate precision in three concentration levels (RSD 1.17-1.28%; 1.29-1.71%, respectively. Therefore, the methods developed are excellent alternatives to sophisticated instrumental methods and can be easily applied in any pharmaceutical laboratory routine due to simple and fast executions.
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International Nuclear Information System (INIS)
Pereira, Elaine; Silva, Ieda de S.; Gomide, Ricardo G.; Pires, Maria Aparecida F.
2015-01-01
This work presents a low cost, simple and new methodology for direct determination uranium in different matrices uranium: organic phase (UO 2 (NO 3 ) 2 .2TBP - uranyl nitrate complex) and aqueous phase (UO 2 (NO 3 ) 2 - NTU - uranyl nitrate), based on Fourier Transform Infrared spectroscopy (FTIR) using KBr pellets technique. The analytical validation is essential to define if a developed methodology is completely adjusted to the objectives that it is destined and is considered one of the main instruments of quality control. The parameters used in the validation process were: selectivity, linearity, limits of detection (LD) and quantitation (LQ), precision (repeatability and intermediate precision), accuracy and robustness. The method for uranium in organic phase (UO 2 (NO 3 ) 2 .2TBP in hexane/embedded in KBr) was linear (r=0.9989) over the range of 1.0 g L -1 a 14.3 g L -1 , LD were 92.1 mg L -1 and LQ 113.1 mg L -1 , precision (RSD < 1.6% and p-value < 0.05), accurate (recovery of 100.1% - 102.9%). The method for uranium aqueous phase (UO 2 (NO 3 )2/embedded in KBr) was linear (r=0.9964) over the range of 5.4 g L -1 a 51.2 g L -1 , LD were 835 mg L -1 and LQ 958 mg L -1 , precision (RSD < 1.0% and p-value < 0.05), accurate (recovery of 99.1% - 102.0%). The FTIR method is robust regarding most of the variables analyzed, as the difference between results obtained under nominal and modified conditions were lower than the critical value for all analytical parameters studied. Some process samples were analyzed in FTIR and compared with gravimetric and x ray fluorescence (XRF) analyses showing similar results in all three methods. The statistical tests (Student-t and Fischer) showed that the techniques are equivalent. (author)
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Takabatake, Reona; Koiwa, Tomohiro; Kasahara, Masaki; Takashima, Kaori; Futo, Satoshi; Minegishi, Yasutaka; Akiyama, Hiroshi; Teshima, Reiko; Oguchi, Taichi; Mano, Junichi; Furui, Satoshi; Kitta, Kazumi
2011-01-01
To reduce the cost and time required to routinely perform the genetically modified organism (GMO) test, we developed a duplex quantitative real-time PCR method for a screening analysis simultaneously targeting an event-specific segment for GA21 and Cauliflower Mosaic Virus 35S promoter (P35S) segment [Oguchi et al., J. Food Hyg. Soc. Japan, 50, 117-125 (2009)]. To confirm the validity of the method, an interlaboratory collaborative study was conducted. In the collaborative study, conversion factors (Cfs), which are required to calculate the GMO amount (%), were first determined for two real-time PCR instruments, the ABI PRISM 7900HT and the ABI PRISM 7500. A blind test was then conducted. The limit of quantitation for both GA21 and P35S was estimated to be 0.5% or less. The trueness and precision were evaluated as the bias and reproducibility of the relative standard deviation (RSD(R)). The determined bias and RSD(R) were each less than 25%. We believe the developed method would be useful for the practical screening analysis of GM maize.
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New methods for precision Moeller polarimetry*
International Nuclear Information System (INIS)
Gaskell, D.; Meekins, D.G.; Yan, C.
2007-01-01
Precision electron beam polarimetry is becoming increasingly important as parity violation experiments attempt to probe the frontiers of the standard model. In the few GeV regime, Moeller polarimetry is well suited to high-precision measurements, however is generally limited to use at relatively low beam currents (<10 μA). We present a novel technique that will enable precision Moeller polarimetry at very large currents, up to 100 μA. (orig.)
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Fast and precise method of contingency ranking in modern power system
DEFF Research Database (Denmark)
Rather, Zakir Hussain; Chen, Zhe; Thøgersen, Paul
2011-01-01
Contingency Analysis is one of the most important aspect of Power System Security Analysis. This paper presents a fast and precise method of contingency ranking for effective power system security analysis. The method proposed in this research work takes due consideration of both apparent power o...... is based on realistic approach taking practical situations into account. Besides taking real situations into consideration the proposed method is fast enough to be considered for on-line security analysis.......Contingency Analysis is one of the most important aspect of Power System Security Analysis. This paper presents a fast and precise method of contingency ranking for effective power system security analysis. The method proposed in this research work takes due consideration of both apparent power...
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Chen, Xiaoshuang; Li, Gaofeng; Ma, Shangfang; Hu, Xujia
2015-07-01
A simple, sensitive and rapid centrifugation-assisted solid-phase extraction (SPE) with high-performance liquid chromatography (SPE-HPLC) method was developed for simultaneous determination of the metabolites loureirin A and loureirin B from Dragon's blood in rat plasma and urine. The development of the extraction procedure included optimization of some important extraction phases. After evaluation, the metabolites of Dragon's blood were extracted by centrifugation-assisted SPE and separated by using HPLC. This method showed good linearity (r(2) > 0.99), and in the rat plasma and urine, the recoveries were 93.1 and 95.7% for loureirin A and were 90.1 and 94.2% for loureirin B. The relative standard deviation (RSD) values of intraday and interday precision in rat plasma and urine for loureirin A were <3.84 and 2.01%, respectively. The RSD values of the intraday and interday precision in rat plasma and urine for loureirin B were below 4.25 and 5.83%, respectively. Thus, the established method is suitable for metabolism studies of loureirin A and loureirin B in rat plasma and urine. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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Batch and flow-injection methods for the spectrophotometric determination of olanzapine
Energy Technology Data Exchange (ETDEWEB)
Jasinska, A.; Nalewajko, E
2004-04-22
An indirect batch spectrophotometric and direct flow-injection (FI) visible spectrophotometric methods have been developed for the determination of the novel anti-psychotic drug olanzapine (OLA). The batch method is based on the oxidation of olanzapine by a known excess of potassium hexacyanoferrate(III) in the presence of the mixture of sulphuric and phosphoric acids (1:1 (v/v)). The absorbance of unreacted oxidant is measured at 425 nm. The absorbance decreases linearly with increasing concentration of the assayed drug. The FI method with detection at 540 nm is based on the direct oxidation of olanzapine one of two oxidants, cerium(IV) sulphate or potassium hexacyanoferrate(III) in acidic medium. The calibration graph were linear over the range of 2.5-40 {mu}g ml{sup -1} in the batch method and 0.05-300 and 0.5-250 {mu}g ml{sup -1} in the FI methods, used cerium (IV) sulphate and potassium hexacyanoferrate (III) respectively. Both FI methods gave similar results in terms of precision and accuracy. The relative standard deviation (R.S.D.), was <1%. The accuracy, obtained from recovery experiments, was 97.9-99.4%. The batch method gave slightly higher R.S.D. values (up to 2.3%) and lower values of accuracy (the recovery was between 96.5 and 96.6%). The methods developed were applied to the determination of olanzapine in a pharmaceutical product.
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Precise charge density studies by maximum entropy method
Takata, M
2003-01-01
For the production research and development of nanomaterials, their structural information is indispensable. Recently, a sophisticated analytical method, which is based on information theory, the Maximum Entropy Method (MEM) using synchrotron radiation powder data, has been successfully applied to determine precise charge densities of metallofullerenes and nanochannel microporous compounds. The results revealed various endohedral natures of metallofullerenes and one-dimensional array formation of adsorbed gas molecules in nanochannel microporous compounds. The concept of MEM analysis was also described briefly. (author)
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High precision isotopic ratio analysis of volatile metal chelates
International Nuclear Information System (INIS)
Hachey, D.L.; Blais, J.C.; Klein, P.D.
1980-01-01
High precision isotope ratio measurements have been made for a series of volatile alkaline earth and transition metal chelates using conventional GC/MS instrumentation. Electron ionization was used for alkaline earth chelates, whereas isobutane chemical ionization was used for transition metal studies. Natural isotopic abundances were determined for a series of Mg, Ca, Cr, Fe, Ni, Cu, Cd, and Zn chelates. Absolute accuracy ranged between 0.01 and 1.19 at. %. Absolute precision ranged between +-0.01-0.27 at. % (RSD +- 0.07-10.26%) for elements that contained as many as eight natural isotopes. Calibration curves were prepared using natural abundance metals and their enriched 50 Cr, 60 Ni, and 65 Cu isotopes covering the range 0.1-1010.7 at. % excess. A separate multiple isotope calibration curve was similarly prepared using enriched 60 Ni (0.02-2.15 at. % excess) and 62 Ni (0.23-18.5 at. % excess). The samples were analyzed by GC/CI/MS. Human plasma, containing enriched 26 Mg and 44 Ca, was analyzed by EI/MS. 1 figure, 5 tables
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Chang, Yuwei; Zhao, Chunxia; Wu, Zeming; Zhou, Jia; Zhao, Sumin; Lu, Xin; Xu, Guowang
2012-08-01
In this work a chip-based nano HPLC coupled MS (HPLC-chip/MS) method with a simple sample preparation procedure was developed for the flavonoid profiling of soybean. The analytical properties of the method including the linearity (R(2) , 0.992-0.995), reproducibility (RSD, 1.50-7.66%), intraday precision (RSD, 1.41-5.14%) and interday precision (RSD, 2.76-16.90%) were satisfactory. Compared with the conventional HPLC/MS method, a fast extraction and analysis procedure was applied and more flavonoids were detected in a single run. Additionally, 13 flavonoids in soybean seed were identified for the first time. The method was then applied to the profiling of six varieties of soybean sowed at the same place. A clear discrimination was observed among different cultivars, three isoflavones, accounting for nearly 80% of total flavonoid contents, were found increased in the spring soybeans compared with the summer cultivars. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Directory of Open Access Journals (Sweden)
Shahinaz Mohammed
2017-10-01
Full Text Available In this study a simple, accurate and precise UV- spectrophotometric method was developed for the estimation of bisoprolol fumarate (BF in bulk and tablet dosage form. The method was based on measurement of absorbance of BF aqueous solution at 225 nm. Validation was conducted in accordance to ICH guidelines. The calibration curve was linear in the concentration range 5.0-30.0 µg/mL with correlation coefficient not less than 0.996. The limit of detection and limit of quantification were 0.22 μg/ml and 0.66 μg/ml, respectively. Intraday and intermediate precision of the developed method were reflected by the low RSD% values (1.19 and 0.854, respectively. The recovery percentage was 100.6 ± 0.6%, n=3. The proposed method was applied for the assay of BF in three different brands.
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International Nuclear Information System (INIS)
Malinsky, Michelle Duval; Jacoby, Cliffton B.; Reagen, William K.
2011-01-01
We report herein a simple protein precipitation extraction-liquid chromatography tandem mass spectrometry (LC/MS/MS) method, validation, and application for the analysis of perfluorinated carboxylic acids (C7-C12), perfluorinated sulfonic acids (C4, C6, and C8), and perfluorooctane sulfonamide (FOSA) in fish fillet tissue. The method combines a rapid homogenization and protein precipitation tissue extraction procedure using stable-isotope internal standard (IS) calibration. Method validation in bluegill (Lepomis macrochirus) fillet tissue evaluated the following: (1) method accuracy and precision in both extracted matrix-matched calibration and solvent (unextracted) calibration, (2) quantitation of mixed branched and linear isomers of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) with linear isomer calibration, (3) quantitation of low level (ppb) perfluorinated compounds (PFCs) in the presence of high level (ppm) PFOS, and (4) specificity from matrix interferences. Both calibration techniques produced method accuracy of at least 100 ± 13% with a precision (%RSD) ≤18% for all target analytes. Method accuracy and precision results for fillet samples from nine different fish species taken from the Mississippi River in 2008 and 2009 are also presented.
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Energy Technology Data Exchange (ETDEWEB)
Malinsky, Michelle Duval, E-mail: mmalinsky@mmm.com [3M Environmental Laboratory, 3M Center, Building 0260-05-N-17, St. Paul, MN 55144-1000 (United States); Jacoby, Cliffton B.; Reagen, William K. [3M Environmental Laboratory, 3M Center, Building 0260-05-N-17, St. Paul, MN 55144-1000 (United States)
2011-01-10
We report herein a simple protein precipitation extraction-liquid chromatography tandem mass spectrometry (LC/MS/MS) method, validation, and application for the analysis of perfluorinated carboxylic acids (C7-C12), perfluorinated sulfonic acids (C4, C6, and C8), and perfluorooctane sulfonamide (FOSA) in fish fillet tissue. The method combines a rapid homogenization and protein precipitation tissue extraction procedure using stable-isotope internal standard (IS) calibration. Method validation in bluegill (Lepomis macrochirus) fillet tissue evaluated the following: (1) method accuracy and precision in both extracted matrix-matched calibration and solvent (unextracted) calibration, (2) quantitation of mixed branched and linear isomers of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) with linear isomer calibration, (3) quantitation of low level (ppb) perfluorinated compounds (PFCs) in the presence of high level (ppm) PFOS, and (4) specificity from matrix interferences. Both calibration techniques produced method accuracy of at least 100 {+-} 13% with a precision (%RSD) {<=}18% for all target analytes. Method accuracy and precision results for fillet samples from nine different fish species taken from the Mississippi River in 2008 and 2009 are also presented.
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Precise positioning method for multi-process connecting based on binocular vision
Liu, Wei; Ding, Lichao; Zhao, Kai; Li, Xiao; Wang, Ling; Jia, Zhenyuan
2016-01-01
With the rapid development of aviation and aerospace, the demand for metal coating parts such as antenna reflector, eddy-current sensor and signal transmitter, etc. is more and more urgent. Such parts with varied feature dimensions, complex three-dimensional structures, and high geometric accuracy are generally fabricated by the combination of different manufacturing technology. However, it is difficult to ensure the machining precision because of the connection error between different processing methods. Therefore, a precise positioning method is proposed based on binocular micro stereo vision in this paper. Firstly, a novel and efficient camera calibration method for stereoscopic microscope is presented to solve the problems of narrow view field, small depth of focus and too many nonlinear distortions. Secondly, the extraction algorithms for law curve and free curve are given, and the spatial position relationship between the micro vision system and the machining system is determined accurately. Thirdly, a precise positioning system based on micro stereovision is set up and then embedded in a CNC machining experiment platform. Finally, the verification experiment of the positioning accuracy is conducted and the experimental results indicated that the average errors of the proposed method in the X and Y directions are 2.250 μm and 1.777 μm, respectively.
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Method for obtaining more precise measures of excreted organic carbon
International Nuclear Information System (INIS)
Anon.
1977-01-01
A new method for concentrating and measuring excreted organic carbon by lyophilization and scintillation counting is efficient, improves measurable radioactivity, and increases precision for estimates of organic carbon excreted by phytoplankton and macrophytes
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QuEChERS-HPLC-DAD method for sulphonamides in chicken breast
Directory of Open Access Journals (Sweden)
Simone Caetani Machado
2013-03-01
Full Text Available The development of a QuEChERS-HPLC-DAD method using a Lichrospher 60 RP-Select B column (250 x 4.6 mm x 5 µm at 40ºC, mobile phase constituted by phosphate buffer:acetonitrile (75:25, v/v at a initial flow rate of 0.5 mL min-1, increased by 1.2 mL min-1 and at 265 nm is presented for simultaneous determination of sulphadiazine, sulphametoxipiridazine and sulphamethoxazole in chicken breast samples. QuEchERS is inexpensive, fast and easy, and the extraction of the analytes of the matrix was successfully employed. In addition, the method presented linearity, in the range of 25, 50, 100, 150, 175, and 200 µg kg-1, precision, selectivity and sensitivity. The intraday precision (RSD % for QuEChERS method was between 3.6-10.8 (SDZ, 6.9-14.1 (SPZ and 1.9-10.9 (SMX and interday precision (RSD% was between 1.5-9.7, 1.7-4.1 and 2.1-10.2, respectively. Results of accuracy (bias were in the range of -8.6 to +11.9 %. Therefore, the validated method is clearly useful for the practical residue monitoring of the drugs evaluated in chicken samples, as all the values were within the acceptable criteria used for food safety. Of 6 samples analyzed, none of them showed contamination of the sulphonamides studied at detectable levels.O desenvolvimento de um método QuEChERS-HPLC-DAD usando uma coluna Lichrospher RP-60 Select B (250 x 4,6 mm x 5 µm a 40 ºC, fase móvel constituída por tampão de fosfato: acetonitrila (75:25, v/v a uma vazão inicial de 0,5 mL min-1, aumentando 1,2 mL min-1 e a 265 nm é apresentado para a determinação simultânea de sulfadiazina, sulfametoxipiridazina e sulfametoxazol em amostras de peito de frango. O QuEChERS é barato, rápido e fácil, e a extração dos analitos da matriz foi empregada com sucesso. Além disso, o método apresentou linearidade, na faixa de 25, 50, 100, 150, 175 e 200 µg kg-1, precisão, seletividade e sensibilidade. A precisão intradia (RSD % para o método QuEChERS foi entre 3,6-10,8 (SDZ, 6,9-14,1 (SPZ
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Directory of Open Access Journals (Sweden)
Krunoslav Margić
2001-11-01
Full Text Available Background. CRPS/RSD still offers more questionsthen answers. The initial events and pathophysiology are unknown,the treatment is unsuccessful and the results are poor.The authors have transmitted their experiences with continuoussensory analgesia of brachial plexus in the treatment ofheavy injured hands to the treatment of CRPS. Efficient analgesia,control of vegetative nerve system and painless exercisesare of outmost importance in the treatment of CRPS.Patients and methods. From 1996 to 1998 we have used continuoussensory analgesia in the treatment of 8 patients withCRPS of the upper extremity. All of them were treated fewmonths after injury.Results. Two to four years after treatment six of eight havebeen ranged as good result (only temporary pain judged onsubjective pain scale as 2; ROM of wrist higher than 50%of normal, lack of 30° of ROM of fingers; hand and key gripgreater than 50% of normal hand.
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The various correction methods to the high precision aeromagnetic data
International Nuclear Information System (INIS)
Xu Guocang; Zhu Lin; Ning Yuanli; Meng Xiangbao; Zhang Hongjian
2014-01-01
In the airborne geophysical survey, an outstanding achievement first depends on the measurement precision of the instrument, and the choice of measurement conditions, the reliability of data collection, followed by the correct method of measurement data processing, the rationality of the data interpretation. Obviously, geophysical data processing is an important task for the comprehensive interpretation of the measurement results, processing method is correct or not directly related to the quality of the final results. we have developed a set of personal computer software to aeromagnetic and radiometric survey data processing in the process of actual production and scientific research in recent years, and successfully applied to the production. The processing methods and flowcharts to the high precision aromagnetic data were simply introduced in this paper. However, the mathematical techniques of the various correction programes to IGRF and flying height and magnetic diurnal variation were stressily discussed in the paper. Their processing effectness were illustrated by taking an example as well. (authors)
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Directory of Open Access Journals (Sweden)
Somayyeh Nadi Ravandi
2016-10-01
Full Text Available MEDLINE is one of the valuable sources of medical information on the Internet. Among the different open access sites of MEDLINE, PubMed is the best-known site. In 2010, iPubMed was established with an interaction-fuzzy search method for MEDLINE access. In the present work, we aimed to compare the precision of the retrieved sources (Best, Useful and Objective precision in the PubMed and iPubMed using two search methods (simple and MeSH search in PubMed and interaction-fuzzy method in iPubmed. During our semi-empirical study period, we held training workshops for 61 students of higher education to teach them Simple Search, MeSH Search, and Fuzzy-Interaction Search methods. Then, the precision of 305 searches for each method prepared by the students was calculated on the basis of Best precision, Useful precision, and Objective precision formulas. Analyses were done in SPSS version 11.5 using the Friedman and Wilcoxon Test, and three precisions obtained with the three precision formulas were studied for the three search methods. The mean precision of the interaction-fuzzy Search method was higher than that of the simple search and MeSH search for all three types of precision, i.e., Best precision, Useful precision, and Objective precision, and the Simple search method was in the next rank, and their mean precisions were significantly different (P < 0.001. The precision of the interaction-fuzzy search method in iPubmed was investigated for the first time. Also for the first time, three types of precision were evaluated in PubMed and iPubmed. The results showed that the Interaction-Fuzzy search method is more precise than using the natural language search (simple search and MeSH search, and users of this method found papers that were more related to their queries; even though search in Pubmed is useful, it is important that users apply new search methods to obtain the best results.
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Gollapudi, Deepika; Wycuff, Diane L; Schwartz, Richard M; Cooper, Jonathan W; Cheng, K C
2017-10-01
In this paper, we describe development of a high-throughput, highly sensitive method based on Lab Chip CGE-SDS platform for purity determination and characterization of virus-like particle (VLP) vaccines. A capillary gel electrophoresis approach requiring about 41 s per sample for analysis and demonstrating sensitivity to protein initial concentrations as low as 20 μg/mL, this method has been used previously to evaluate monoclonal antibodies, but this application for lot release assay of VLPs using this platform is unique. The method was qualified and shown to be accurate for the quantitation of VLP purity. Assay repeatability was confirmed to be less than 2% relative standard deviation of the mean (% RSD) with interday precision less than 2% RSD. The assay can evaluate purified VLPs in a concentration range of 20-249 μg/mL for VEE and 20-250 μg/mL for EEE and WEE VLPs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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[Precision nutrition in the era of precision medicine].
Chen, P Z; Wang, H
2016-12-06
Precision medicine has been increasingly incorporated into clinical practice and is enabling a new era for disease prevention and treatment. As an important constituent of precision medicine, precision nutrition has also been drawing more attention during physical examinations. The main aim of precision nutrition is to provide safe and efficient intervention methods for disease treatment and management, through fully considering the genetics, lifestyle (dietary, exercise and lifestyle choices), metabolic status, gut microbiota and physiological status (nutrient level and disease status) of individuals. Three major components should be considered in precision nutrition, including individual criteria for sufficient nutritional status, biomarker monitoring or techniques for nutrient detection and the applicable therapeutic or intervention methods. It was suggested that, in clinical practice, many inherited and chronic metabolic diseases might be prevented or managed through precision nutritional intervention. For generally healthy populations, because lifestyles, dietary factors, genetic factors and environmental exposures vary among individuals, precision nutrition is warranted to improve their physical activity and reduce disease risks. In summary, research and practice is leading toward precision nutrition becoming an integral constituent of clinical nutrition and disease prevention in the era of precision medicine.
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A High-precision Motion Compensation Method for SAR Based on Image Intensity Optimization
Directory of Open Access Journals (Sweden)
Hu Ke-bin
2015-02-01
Full Text Available Owing to the platform instability and precision limitations of motion sensors, motion errors negatively affect the quality of synthetic aperture radar (SAR images. The autofocus Back Projection (BP algorithm based on the optimization of image sharpness compensates for motion errors through phase error estimation. This method can attain relatively good performance, while assuming the same phase error for all pixels, i.e., it ignores the spatial variance of motion errors. To overcome this drawback, a high-precision motion error compensation method is presented in this study. In the proposed method, the Antenna Phase Centers (APC are estimated via optimization using the criterion of maximum image intensity. Then, the estimated APCs are applied for BP imaging. Because the APC estimation equals the range history estimation for each pixel, high-precision phase compensation for every pixel can be achieved. Point-target simulations and processing of experimental data validate the effectiveness of the proposed method.
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A New High-Precision Correction Method of Temperature Distribution in Model Stellar Atmospheres
Directory of Open Access Journals (Sweden)
Sapar A.
2013-06-01
Full Text Available The main features of the temperature correction methods, suggested and used in modeling of plane-parallel stellar atmospheres, are discussed. The main features of the new method are described. Derivation of the formulae for a version of the Unsöld-Lucy method, used by us in the SMART (Stellar Model Atmospheres and Radiative Transport software for modeling stellar atmospheres, is presented. The method is based on a correction of the model temperature distribution based on minimizing differences of flux from its accepted constant value and on the requirement of the lack of its gradient, meaning that local source and sink terms of radiation must be equal. The final relative flux constancy obtainable by the method with the SMART code turned out to have the precision of the order of 0.5 %. Some of the rapidly converging iteration steps can be useful before starting the high-precision model correction. The corrections of both the flux value and of its gradient, like in Unsöld-Lucy method, are unavoidably needed to obtain high-precision flux constancy. A new temperature correction method to obtain high-precision flux constancy for plane-parallel LTE model stellar atmospheres is proposed and studied. The non-linear optimization is carried out by the least squares, in which the Levenberg-Marquardt correction method and thereafter additional correction by the Broyden iteration loop were applied. Small finite differences of temperature (δT/T = 10−3 are used in the computations. A single Jacobian step appears to be mostly sufficient to get flux constancy of the order 10−2 %. The dual numbers and their generalization – the dual complex numbers (the duplex numbers – enable automatically to get the derivatives in the nilpotent part of the dual numbers. A version of the SMART software is in the stage of refactorization to dual and duplex numbers, what enables to get rid of the finite differences, as an additional source of lowering precision of the
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A Dynamic Precision Evaluation Method for the Star Sensor in the Stellar-Inertial Navigation System.
Lu, Jiazhen; Lei, Chaohua; Yang, Yanqiang
2017-06-28
Integrating the advantages of INS (inertial navigation system) and the star sensor, the stellar-inertial navigation system has been used for a wide variety of applications. The star sensor is a high-precision attitude measurement instrument; therefore, determining how to validate its accuracy is critical in guaranteeing its practical precision. The dynamic precision evaluation of the star sensor is more difficult than a static precision evaluation because of dynamic reference values and other impacts. This paper proposes a dynamic precision verification method of star sensor with the aid of inertial navigation device to realize real-time attitude accuracy measurement. Based on the gold-standard reference generated by the star simulator, the altitude and azimuth angle errors of the star sensor are calculated for evaluation criteria. With the goal of diminishing the impacts of factors such as the sensors' drift and devices, the innovative aspect of this method is to employ static accuracy for comparison. If the dynamic results are as good as the static results, which have accuracy comparable to the single star sensor's precision, the practical precision of the star sensor is sufficiently high to meet the requirements of the system specification. The experiments demonstrate the feasibility and effectiveness of the proposed method.
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Meade, Rhiana D; Murray, Anna L; Mittelman, Anjuliee M; Rayner, Justine; Lantagne, Daniele S
2017-02-01
Locally manufactured ceramic water filters are one effective household drinking water treatment technology. During manufacturing, silver nanoparticles or silver nitrate are applied to prevent microbiological growth within the filter and increase bacterial removal efficacy. Currently, there is no recommendation for manufacturers to test silver concentrations of application solutions or filtered water. We identified six commercially available silver test strips, kits, and meters, and evaluated them by: (1) measuring in quintuplicate six samples from 100 to 1,000 mg/L (application range) and six samples from 0.0 to 1.0 mg/L (effluent range) of silver nanoparticles and silver nitrate to determine accuracy and precision; (2) conducting volunteer testing to assess ease-of-use; and (3) comparing costs. We found no method accurately detected silver nanoparticles, and accuracy ranged from 4 to 91% measurement error for silver nitrate samples. Most methods were precise, but only one method could test both application and effluent concentration ranges of silver nitrate. Volunteers considered test strip methods easiest. The cost for 100 tests ranged from 36 to 1,600 USD. We found no currently available method accurately and precisely measured both silver types at reasonable cost and ease-of-use, thus these methods are not recommended to manufacturers. We recommend development of field-appropriate methods that accurately and precisely measure silver nanoparticle and silver nitrate concentrations.
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Gray, Dean E; Porter, Andrew; O'Neill, Terry; Harris, Roger K; Rottinghaus, George E
2004-01-01
Preparations from comfrey (Symphytum officinale and S. x uplandicum) root and leaf contain varying levels of the hepatotoxic pyrrolizidine alkaloids (PAs). Reference compounds for comfrey are not commercially available, and there is currently no rapid extraction or analytical method capable of determining low levels in raw materials or as adulterants in commercially available extracts. A solid-phase extraction (SPE) method was developed using an Ergosil cleanup column that specifically binds the PAs. With this method, powdered comfrey root was extracted by sonication and shaking with basic chloroform. The extract was applied to the cleanup column under vacuum, washed with 2 mL acetone-chloroform (8 + 2, v/v) followed by 2 mL petroleum ether to remove excess chloroform. The column was dried under vacuum, and the PAs were eluted with 2 successive 1 mL aliquots methanol. Percent recoveries of the PAs following Ergosil SPE had an overall average of 96.8%, with RSD of 3.8% over a range of 1.0 to 25.0 g extracted in 100 mL. Average precision of the method (n = 3 over 4 extraction concentrations) gave an overall RSD of 6.0% for the 5 alkaloids, with a range of 0.8% (5 g in 100 mL) to 11.2% (25 g in 100 mL). Recovery optimization testing showed that 1.0 g comfrey root extracted in 100 mL yielded the greatest recovery (% dry weight) of the PAs, with an extraction efficiency and accuracy of 94.2%, and RSD of 1.7% (n = 9). The unique properties of the Ergosil cleanup column provide rapid sample cleanup, volume reduction, and concentration of PAs from comfrey extracts, and allow the eluant to be analyzed directly by traditional chromatographic methods.
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Method validation and stability study of quercetin in topical emulsions
Directory of Open Access Journals (Sweden)
Rúbia Casagrande
2009-01-01
Full Text Available This study validated a high performance liquid chromatography (HPLC method for the quantitative evaluation of quercetin in topical emulsions. The method was linear within 0.05 - 200 μg/mL range with a correlation coefficient of 0.9997, and without interference in the quercetin peak. The detection and quantitation limits were 18 and 29 ng/mL, respectively. The intra- and inter-assay precisions presented R.S.D. values lower than 2%. An average of 93% and 94% of quercetin was recovered for non-ionic and anionic emulsions, respectively. The raw material and anionic emulsion, but not non-ionic emulsion, were stable in all storage conditions for one year. The method reported is a fast and reliable HPLC technique useful for quercetin determination in topical emulsions.
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A Sensitive Validated Spectrophotometric Method for the Determination of Flucloxacillin Sodium
Directory of Open Access Journals (Sweden)
R. Singh Gujral
2009-01-01
Full Text Available A simple and sensitive spectrophotometric method has been proposed for the determination of flucloxacillin sodium. The determination method is based on charge transfer complexation reaction of the drug with iodine in methanol-dichloromethane medium. The absorbance was measured at 362 nm against the reagent blank. Under optimized experimental conditions, Beer's law is obeyed in the concentration ranges 1-9 μg/mL for flucloxacillin. The method was validated for specificity, linearity, precision, accuracy. The degree of linearity of the calibration curves, the percent recoveries, limit of detection and quantitation for the spectrophotometric method were determined. No interferences could be observed from the additives commonly present in the pharmaceutical formulations. The method was successfully applied for in vitro determination of human urine samples with low RSD value. This is simple, specific, accurate and sensitive spectrophotometric method.
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Sutherland, Andrew M; Parrella, Michael P
2011-08-01
Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is a major horticultural pest and an important vector of plant viruses in many parts of the world. Methods for assessing thrips population density for pest management decision support are often inaccurate or imprecise due to thrips' positive thigmotaxis, small size, and naturally aggregated populations. Two established methods, flower tapping and an alcohol wash, were compared with a novel method, plant desiccation coupled with passive trapping, using accuracy, precision and economic efficiency as comparative variables. Observed accuracy was statistically similar and low (37.8-53.6%) for all three methods. Flower tapping was the least expensive method, in terms of person-hours, whereas the alcohol wash method was the most expensive. Precision, expressed by relative variation, depended on location within the greenhouse, location on greenhouse benches, and the sampling week, but it was generally highest for the flower tapping and desiccation methods. Economic efficiency, expressed by relative net precision, was highest for the flower tapping method and lowest for the alcohol wash method. Advantages and disadvantages are discussed for all three methods used. If relative density assessment methods such as these can all be assumed to accurately estimate a constant proportion of absolute density, then high precision becomes the methodological goal in terms of measuring insect population density, decision making for pest management, and pesticide efficacy assessments.
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Energy Technology Data Exchange (ETDEWEB)
Gomes, Marcos S. [Departamento de Química, Universidade Federal de São Carlos, Rod. Washington Luís, km 235, 13565-905 São Carlos, SP (Brazil); Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000 Piracicaba, SP (Brazil); Schenk, Emily R. [Department of Chemistry and Biochemistry, Florida International University, Miami, FL (United States); International Forensic Research Institute, Florida International University, Miami, FL (United States); Santos, Dário [Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, Rua Professor Arthur Riedel 275, Diadema, SP (Brazil); Krug, Francisco José [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000 Piracicaba, SP (Brazil); Almirall, José R., E-mail: almirall@fiu.edu [Department of Chemistry and Biochemistry, Florida International University, Miami, FL (United States); International Forensic Research Institute, Florida International University, Miami, FL (United States)
2014-04-01
An evaluation of laser ablation inductively coupled plasma optical emission spectroscopy (LAICP OES) for the direct analysis of pelleted plant material is reported. Ground leaves of orange citrus, soy and sugarcane were comminuted using a high-speed ball mill, pressed into pellets and sampled directly with laser ablation and analyzed by ICP OES. The limits of detection (LODs) for the method ranged from as low as 0.1 mg kg{sup −1} for Zn to as high as 94 mg kg{sup −1} for K but were generally below 6 mg kg{sup −1} for most of the elements of interest. A certified reference material consisting of a similar matrix (NIST SRM 1547 peach leaves) was used to check the accuracy of the calibration and the reported method resulted in an average bias of ∼ 5% for all the elements of interest. The precision for the reported method ranged from as low as 4% relative standard deviation (RSD) for Mn to as high as 17% RSD for Zn but averaged ∼ 6.5% RSD for all the elements (n = 10). The proposed method was tested for the determination of Ca, Mg, P, K, Fe, Mn, Zn and B, and the results were in good agreement with those obtained for the corresponding acid digests by ICP-OES, no differences being observed by applying a paired t-test at the 95% confidence level. The reported direct solid sampling method provides a fast alternative to acid digestion that results in similar and appropriate analytical figures of merit with regard to sensitivity, accuracy and precision for plant material analysis. - Highlights: • An evaluation of LA-ICP-OES for the direct analysis of pelleted plant material is reported. • Orange citrus, soy and sugarcane plants were pressed into pellets and sampled directly. • The element menu consisted of Ca, Mg, P, K, Fe, Mn, Zn and B. • LODs for the method ranged from 0.1 mg kg{sup −1} for Zn to 94 mg kg{sup −1} for K. • The precision ranged from 4% RSD for Mn to 17% RSD for Zn (∼ 6.5% RSD average)
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Vernakalant: RSD 1235, RSD-1235, RSD1235.
2007-01-01
Vernakalant is an atrial-selective antiarrhythmic drug discovered by Cardiome Pharma (formerly Nortran Pharmaceuticals). Vernakalant may have potential in the treatment of atrial arrhythmias, including acute atrial fibrillation and atrial flutter. Vernakalant is a mixed sodium/potassium channel blocker and selectively blocks ion channels in the heart that are known to be active during episodes of atrial fibrillation. An IV formulation of vernakalant is awaiting registration in the US for the acute conversion of atrial fibrillation. Also, an oral formulation of the compound is in phase II clinical development as a chronic-use product for the maintenance of normal heart rhythm following termination of atrial fibrillation. Cardiome is seeking co-development partners for intravenous vernakalant in the treatment of atrial arrhythmia, atrial fibrillation and atrial flutter in Europe and Japan. In October 2003, Cardiome Pharma and Fujisawa Healthcare, the US subsidiary of Fujisawa Pharmaceutical Co., Ltd (now Astellas Pharma), executed a $US68 million strategic partnership agreement for the co-development of vernakalant. On 1 April 2005, Fujisawa merged with Yamanouchi to form Astellas Pharma. The partnership grants Astellas Pharma exclusive commercialisation rights for vernakalant. Under the terms of the agreement, Cardiome and Astellas Pharma will co-develop vernakalant as an intravenous formulation for the treatment of atrial fibrillation and atrial flutter for North American markets. Astellas Pharma will be financially responsible for 75% of all future clinical development costs, with Cardiome responsible for the remaining 25% of costs. Astellas Pharma will be responsible for the development plan, NDA application (and NDA re-submission costs) and registration, along with the commercial manufacturing, marketing and sale of vernakalant. Cardiome will manage the phase III trials ACT 1 and ACT 2 and will also be responsible for the continued manufacturing of clinical supplies of vernakalant. Cardiome will receive royalties on end-user sales of vernakalant reflective of Cardiome's 25% share of development costs and other financial considerations. Product rights to the IV formulation of vernakalant for markets outside of North America and world rights to the oral formulation of vernakalant for chronic atrial fibrillation are not included within the scope of this partnership. Cardiome intends to form future additional alliances for these product opportunities or maintain such opportunities for commercialisation on its own. Cardiome and Astellas amended their agreement for vernakalant in relation to the re-submission of the NDA with the US FDA. Under the terms of the new agreement, Astellas agreed to fund 100% of the costs associated with re-submission, including engagement and external consultants. Astellas also agreed to modify the timing of the $US10 million NDA milestone to the date of resubmission. In February 2005, Cardiome Pharma received a $US6 million milestone payment from its co-development partner, Fujisawa Healthcare Inc. This milestone payment was triggered by the successful completion of ACT 1.A pivotal phase II trial demonstrated in September 2002 that vernakalant rapidly and effectively terminated recent onset atrial fibrillation and the study met both primary and secondary study endpoints. Following discussions with the FDA, Cardiome initiated three separate phase III clinical trials in order to enable Cardiome to apply for marketing approval for vernakalant. In August 2003, Cardiome Pharma commenced patient dosing in its first phase III efficacy study of vernakalant for the acute treatment of atrial fibrillation. This initial study, called ACT 1 (Atrial fibrillation Conversion Trial 1), measured the safety and efficacy of vernakalant in 416 patients with atrial arrhythmias. The placebo-controlled study was carried out in 45 centers in the US, Canada and Scandinavia. The ACT 1 study included two substudies of 60 patients with atrial flutter and 119 patients with longer term atrial fibrillation. The primary efficacy endpoint was acute conversion of atrial arrhythmia to normal heart rhythm. Cardiome commenced its second phase III efficacy study in March 2004, known as ACT 2. The ACT 2 study in post-cardiac surgery (coronary artery bypass graft) patients with atrial fibrillation, evaluated the safety and efficacy of vernakalant (IV) in the termination of atrial arrhythmias in patients after cardiac surgery. Around 210 patients from 25 centres in the US, Canada and Europe were enrolled in this study. The primary efficacy endpoint was acute conversion of atrial arrhythmias to normal heart rhythm. The ACT 2 study is ongoing. The third phase III study, known as ACT 3 (Atrial arrhythmia Conversion Trial 3), was initiated by Cardiome Pharma in July 2004. In September 2005, Cardiome and Astellas reported that ACT 3 had been completed, achieving its primary endpoint, with over half of the 170 patients with recent-onset atrial fibrillation (AF) who received vernakalant intravenously converting to normal heart rhythm, compared with only 4% in the placebo group. The study was being conducted by co-development partner Astellas Pharma and measured the safety and efficacy of intravenous vernakalant in recent onset atrial arrhythmia patients. The placebo-controlled study was being carried out in 276 patients in more than 50 centres throughout the world.ACT 4, a phase III safety study evaluating safety of IV vernakalant in approximately 120 AF patients from 30 centres in the US, Canada and Europe, was initiated in October 2005. Results from this trial are expected to supplement trial results from the pivotal ACT 1 and 3 trials. This study is ongoing. Cardiome Pharma successfully completed phase I studies for its controlled-release oral formulation of vernakalant in 2005. The oral, controlled-release formulation of vernakalant is expected to help prevent or slow the recurrence of atrial fibrillation, and will be used as a follow-on therapy to intravenous vernakalant.
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Real-driving emissions of circulating Spanish car fleet in 2015 using RSD Technology.
Pujadas, M; Domínguez-Sáez, A; De la Fuente, J
2017-01-15
In this paper we present the results corresponding to on-road traffic emissions measurements obtained during two field campaigns developed in the Madrid region (Spain) during 2014 and 2015 in the framework of the CORETRA project. The experimental strategy was based on the use of a RSD 4600 remote sensor in interurban roads. These measurements have produced a global database of >190,000 vehicles with their associated emission data (NO/CO 2 , HC/CO 2 and CO/CO 2 ), which can be considered representative of the current Spanish circulating fleet. The results of M1 vehicles were analysed according to their distribution by Euro Standard and engine model. One of the relevant findings is that, despite the progressive introduction of increasingly stringent standards, no NO emission reduction is observed for diesel vehicles with time, although this behavior shows significative differences among brands and engine models. We have also investigated the presence of "high emitter" (HE) vehicles in the Spanish M1 circulating fleet and most of the HE detected corresponded to diesel vehicles with very high NO/CO 2 values. With these results at hand, we strongly propose the future incorporation of the "high emitter vehicle" definition into the European environmental legislation, as well as the establishment of specific strategies in each country/region in order to identify these anomalous vehicles. Identification and repair of HE vehicles within the European circulating fleets, although are not easy tasks, should be considered very important for the improvement of air quality in the EU. The use of non-intrusive optical technologies (i.e. RSD) is an excellent option to provide instantaneous real emission data of each individual vehicle without disturbing traffic and for on-road fleet monitoring. In summary, it is a good strategy to obtain valuable information about the long term surveillance of real vehicle emission trends, specially after the introduction of new standard. Copyright
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Precision Distances with the Tip of the Red Giant Branch Method
Beaton, Rachael Lynn; Carnegie-Chicago Hubble Program Team
2018-01-01
The Carnegie-Chicago Hubble Program aims to construct a distance ladder that utilizes old stellar populations in the outskirts of galaxies to produce a high precision measurement of the Hubble Constant that is independent of Cepheids. The CCHP uses the tip of the red giant branch (TRGB) method, which is a statistical measurement technique that utilizes the termination of the red giant branch. Two innovations combine to make the TRGB a competitive route to the Hubble Constant (i) the large-scale measurement of trigonometric parallax by the Gaia mission and (ii) the development of both precise and accurate means of determining the TRGB in both nearby (~1 Mpc) and distant (~20 Mpc) galaxies. Here I will summarize our progress in developing these standardized techniques, focusing on both our edge-detection algorithm and our field selection strategy. Using these methods, the CCHP has determined equally precise (~2%) distances to galaxies in the Local Group (< 1 Mpc) and across the Local Volume (< 20 Mpc). The TRGB is, thus, an incredibly powerful and straightforward means to determine distances to galaxies of any Hubble Type and, thus, has enormous potential for putting any number of astrophyiscal phenomena on absolute units.
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Malinsky, Michelle Duval; Jacoby, Cliffton B; Reagen, William K
2011-01-10
We report herein a simple protein precipitation extraction-liquid chromatography tandem mass spectrometry (LC/MS/MS) method, validation, and application for the analysis of perfluorinated carboxylic acids (C7-C12), perfluorinated sulfonic acids (C4, C6, and C8), and perfluorooctane sulfonamide (FOSA) in fish fillet tissue. The method combines a rapid homogenization and protein precipitation tissue extraction procedure using stable-isotope internal standard (IS) calibration. Method validation in bluegill (Lepomis macrochirus) fillet tissue evaluated the following: (1) method accuracy and precision in both extracted matrix-matched calibration and solvent (unextracted) calibration, (2) quantitation of mixed branched and linear isomers of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) with linear isomer calibration, (3) quantitation of low level (ppb) perfluorinated compounds (PFCs) in the presence of high level (ppm) PFOS, and (4) specificity from matrix interferences. Both calibration techniques produced method accuracy of at least 100±13% with a precision (%RSD) ≤18% for all target analytes. Method accuracy and precision results for fillet samples from nine different fish species taken from the Mississippi River in 2008 and 2009 are also presented. Copyright © 2010 Elsevier B.V. All rights reserved.
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In vivo precision of conventional and digital methods for obtaining quadrant dental impressions.
Ender, Andreas; Zimmermann, Moritz; Attin, Thomas; Mehl, Albert
2016-09-01
Quadrant impressions are commonly used as alternative to full-arch impressions. Digital impression systems provide the ability to take these impressions very quickly; however, few studies have investigated the accuracy of the technique in vivo. The aim of this study is to assess the precision of digital quadrant impressions in vivo in comparison to conventional impression techniques. Impressions were obtained via two conventional (metal full-arch tray, CI, and triple tray, T-Tray) and seven digital impression systems (Lava True Definition Scanner, T-Def; Lava Chairside Oral Scanner, COS; Cadent iTero, ITE; 3Shape Trios, TRI; 3Shape Trios Color, TRC; CEREC Bluecam, Software 4.0, BC4.0; CEREC Bluecam, Software 4.2, BC4.2; and CEREC Omnicam, OC). Impressions were taken three times for each of five subjects (n = 15). The impressions were then superimposed within the test groups. Differences from model surfaces were measured using a normal surface distance method. Precision was calculated using the Perc90_10 value. The values for all test groups were statistically compared. The precision ranged from 18.8 (CI) to 58.5 μm (T-Tray), with the highest precision in the CI, T-Def, BC4.0, TRC, and TRI groups. The deviation pattern varied distinctly depending on the impression method. Impression systems with single-shot capture exhibited greater deviations at the tooth surface whereas high-frame rate impression systems differed more in gingival areas. Triple tray impressions displayed higher local deviation at the occlusal contact areas of upper and lower jaw. Digital quadrant impression methods achieve a level of precision, comparable to conventional impression techniques. However, there are significant differences in terms of absolute values and deviation pattern. With all tested digital impression systems, time efficient capturing of quadrant impressions is possible. The clinical precision of digital quadrant impression models is sufficient to cover a broad variety of
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Binocular optical axis parallelism detection precision analysis based on Monte Carlo method
Ying, Jiaju; Liu, Bingqi
2018-02-01
According to the working principle of the binocular photoelectric instrument optical axis parallelism digital calibration instrument, and in view of all components of the instrument, the various factors affect the system precision is analyzed, and then precision analysis model is established. Based on the error distribution, Monte Carlo method is used to analyze the relationship between the comprehensive error and the change of the center coordinate of the circle target image. The method can further guide the error distribution, optimize control the factors which have greater influence on the comprehensive error, and improve the measurement accuracy of the optical axis parallelism digital calibration instrument.
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Advanced methods and algorithm for high precision astronomical imaging
International Nuclear Information System (INIS)
Ngole-Mboula, Fred-Maurice
2016-01-01
One of the biggest challenges of modern cosmology is to gain a more precise knowledge of the dark energy and the dark matter nature. Fortunately, the dark matter can be traced directly through its gravitational effect on galaxies shapes. The European Spatial Agency Euclid mission will precisely provide data for such a purpose. A critical step is analyzing these data will be to accurately model the instrument Point Spread Function (PSF), which the focus of this thesis.We developed non parametric methods to reliably estimate the PSFs across an instrument field-of-view, based on unresolved stars images and accounting for noise, under sampling and PSFs spatial variability. At the core of these contributions, modern mathematical tools and concepts such as sparsity. An important extension of this work will be to account for the PSFs wavelength dependency. (author) [fr
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Directory of Open Access Journals (Sweden)
Jain P.S.
2012-01-01
Full Text Available A Dissolution method with high performance liquid chromatography (HPLC analysis was validated for perindopril erbumine and indapamide in combination tablet formulation. The method was validated to meet requirements for a global regulatory filing and this validation included specificity, linearity, accuracy, precision, range, robustness and solution stability studies. The dissolution method, which uses USP apparatus 1 with basket rotating at 100 rpm, 1000 ml of phosphate buffer pH 6.8 as the dissolution medium, and reversed-phased HPLC was carried out at 50⁰C on a 4.6mm×250mm 5μm cyano column that contained USP packing L1 with acetonitrile: buffer pH 2.8::40:60 (v/v, as mobile phase. UV detector was set at 225 nm. A method was found to be selective, linear, accurate and precise in the specified ranges. Intra-day and inter-day variability for method was <2% RSD. This method was successfully used for quantification of perindopril erbumine and indapamide combination tablet formulations.
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Directory of Open Access Journals (Sweden)
Bhavil Narola
2010-01-01
Full Text Available This present paper deals with the development and validation of a stability indicating high performance liquid chromatographic method for the quantitative determination of Memantine hydrochloride. Memantine hydrochloride was derivatized with 0.015 M 9-fluorenylmethyl chloroformate (FMOC and 0.5 M borate buffer solution by keeping it at room temperature for about 20 minutes and the chromatographic separation achieved by injecting 10 μL of the derivatized mixture into a Waters HPLC system with photodiode array detector using a kromasil C18 column (150 × 4.6 mm, 5 μ, The mobile phase consisting of 80% acetonitrile and 20% phosphate buffer solution and a flow rate of 2 milliliter/minute. The Memantine was eluted at approximately 7.5 minutes. The volume of FMOC used in derivatization, concentration of FMOC and derivatization time was optimized and used. Forced degradation studies were performed on bulk sample of Memantine hydrochloride using acid (5.0 Normal (N hydrochloric acid, base (1.0 N sodium hydroxide, oxidation (30% hydrogen peroxide, thermal (105 ° C, photolytic and humidity conditions. The developed LC method was validated with respect to specificity, precision (% RSD about 0.70%, linearity (linearity of range about 70-130 μg/mL, ruggedness (Overall % RSD about 0.35%, stability in analytical solution (Cumulative % RSD about 0.11% after 1450 min. and robustness.
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Directory of Open Access Journals (Sweden)
Bhavil Narola
2010-07-01
Full Text Available This present paper deals with the development and validation of a stability indicating high performance liquid chromatographic method for the quantitative determination of Memantine hydrochloride. Memantine hydrochloride was derivatized with 0.015 M 9-fluorenylmethyl chloroformate (FMOC and 0.5 M borate buffer solution by keeping it at room temperature for about 20 minutes and the chromatographic separation achieved by injecting 10 µL of the derivatized mixture into a Waters HPLC system with photodiode array detector using a kromasil C18 column (150 × 4.6 mm, 5 µ. The mobile phase consisting of 80% acetonitrile and 20% phosphate buffer solution and a flow rate of 2 milliliter/minute. The Memantine was eluted at approximately 7.5 minutes. The volume of FMOC used in derivatization, concentration of FMOC and derivatization time was optimized and used. Forced degradation studies were performed on bulk sample of Memantine hydrochloride using acid (5.0 Normal (N hydrochloric acid, base (1.0 N sodium hydroxide, oxidation (30% hydrogen peroxide, thermal (105°C, photolytic and humidity conditions. The developed LC method was validated with respect to specificity, precision (% RSD about 0.70%, linearity (linearity of range about 70–130 µg/mL, ruggedness (Overall % RSD about 0.35%, stability in analytical solution (Cumulative % RSD about 0.11% after 1450 min. and robustness.
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In vivo precision of conventional and digital methods of obtaining complete-arch dental impressions.
Ender, Andreas; Attin, Thomas; Mehl, Albert
2016-03-01
Digital impression systems have undergone significant development in recent years, but few studies have investigated the accuracy of the technique in vivo, particularly compared with conventional impression techniques. The purpose of this in vivo study was to investigate the precision of conventional and digital methods for complete-arch impressions. Complete-arch impressions were obtained using 5 conventional (polyether, POE; vinylsiloxanether, VSE; direct scannable vinylsiloxanether, VSES; digitized scannable vinylsiloxanether, VSES-D; and irreversible hydrocolloid, ALG) and 7 digital (CEREC Bluecam, CER; CEREC Omnicam, OC; Cadent iTero, ITE; Lava COS, LAV; Lava True Definition Scanner, T-Def; 3Shape Trios, TRI; and 3Shape Trios Color, TRC) techniques. Impressions were made 3 times each in 5 participants (N=15). The impressions were then compared within and between the test groups. The cast surfaces were measured point-to-point using the signed nearest neighbor method. Precision was calculated from the (90%-10%)/2 percentile value. The precision ranged from 12.3 μm (VSE) to 167.2 μm (ALG), with the highest precision in the VSE and VSES groups. The deviation pattern varied distinctly according to the impression method. Conventional impressions showed the highest accuracy across the complete dental arch in all groups, except for the ALG group. Conventional and digital impression methods differ significantly in the complete-arch accuracy. Digital impression systems had higher local deviations within the complete arch cast; however, they achieve equal and higher precision than some conventional impression materials. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.
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Fujimori, Kiyoshi; Lee, Hans; Phillips, Joseph; Nashed-Samuel, Yasser
The European Pharmacopeia surface test to analyze the hydrolytic resistance is a common industrial method to understand and ensure the quality of produced glass vials. Hydrolytic resistance is evaluated by calculating the alkalinity of water extract from autoclaved vials by titration. As an alternative to this titration technique, a conductivity technique was assessed, which directly measures the ions in the water extract. A conductivity meter with a 12 mm diameter electrode was calibrated with a 100 μS/cm conductivity standard and carryover minimized by rinsing the probe in a water beaker per analysis. The limit of quantification at 1 μS/cm was determined as having a signal-to-noise ratio of 3 compared with the water blank. The conductivity method was selective for glass-composing elements (boron, sodium, aluminum, silicon, potassium, and calcium) within the vial extract. Accuracies of spiked conductivity standard within the range of 1 to 100 μS/cm were ±7% and had linearity with coefficient of determination (R 2 ) of ≥0.9999. Intraday precision had a relative standard deviation (RSD) (n = 5) of ≤6% for spiked conductivity standard within the range of 1 to 100 μS/cm. Interday precision had a RSD (n = 4) of ≤6% for 10 vials from three glass vial lots. Conductivity of water extracts from nine sets of seven lots of glass vials had a precise linear relationship [R 2 = 0.9876, RSD = 1% (n = 9)] with titration volumes of the same lots. Conductivity results in μS/cm could be converted to titration volumes in milliliters by a conversion factor of 0.0275. The simplicity, sample stability, and individual vial analysis of the conductivity technique were more advantageous than the current titration technique. The quality of glass vials used as primary containers in the pharmaceutical industry is of concern due to recent observations of glass flake-like delamination, or lamellae, under specific storage conditions. The current European Pharmacopoeia method to assess
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Determination of Arctiin and Arctigenin Contents in Arctium Tomentosum Mill. by HPLC Method
Directory of Open Access Journals (Sweden)
Xiaoying Zhou
2011-01-01
Full Text Available A simple, precise, rapid and accurate, binary-phase high performance liquid chromatographic method has been developed for the determination of arctiin and arctigenin contents in the Arctium tomentosumMill. with short run time. Chromatographic separation was achieved by using HPLC system, consisting of a Shimadzu LC-6AD and Kromasil C18 column (250×4.6 mm, 5 μm, with pre-column, the mobile phase consists of methanol and water (55: 45. Detection wavelength was 280 nm. The speed of flow was 1.0 mL/min. The specimen handing quantity was 10 μL. The arctiin’s linearity range was 1.575∼4.725 μg (r=0.9995. The arctigenin’s linearity range was 0.613, 3.063 μg (r = 0.9998 and the linear relationship was accurate. The average recovery (n=5 of arctiin and arctigenin were 101.55% (RSD=2.23% 101.63% (RSD =1.49 % respectively. The contents of arctiin and arctigenin in Arctium tomentosum Mill. were 10.69 mg/g and 0.15 mg/g, respectively. Therefore， the developed HPLC method can be applied to both in vitro studies of arctiin and arctigenin formulations as well as drug estimation in biological samples.
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Su, Gui-yang; Li, Jian-hua; Ma, Ying-hua; Li, Sheng-hong
2004-09-01
With the flooding of pornographic information on the Internet, how to keep people away from that offensive information is becoming one of the most important research areas in network information security. Some applications which can block or filter such information are used. Approaches in those systems can be roughly classified into two kinds: metadata based and content based. With the development of distributed technologies, content based filtering technologies will play a more and more important role in filtering systems. Keyword matching is a content based method used widely in harmful text filtering. Experiments to evaluate the recall and precision of the method showed that the precision of the method is not satisfactory, though the recall of the method is rather high. According to the results, a new pornographic text filtering model based on reconfirming is put forward. Experiments showed that the model is practical, has less loss of recall than the single keyword matching method, and has higher precision.
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Research on a high-precision calibration method for tunable lasers
Xiang, Na; Li, Zhengying; Gui, Xin; Wang, Fan; Hou, Yarong; Wang, Honghai
2018-03-01
Tunable lasers are widely used in the field of optical fiber sensing, but nonlinear tuning exists even for zero external disturbance and limits the accuracy of the demodulation. In this paper, a high-precision calibration method for tunable lasers is proposed. A comb filter is introduced and the real-time output wavelength and scanning rate of the laser are calibrated by linear fitting several time-frequency reference points obtained from it, while the beat signal generated by the auxiliary interferometer is interpolated and frequency multiplied to find more accurate zero crossing points, with these points being used as wavelength counters to resample the comb signal to correct the nonlinear effect, which ensures that the time-frequency reference points of the comb filter are linear. A stability experiment and a strain sensing experiment verify the calibration precision of this method. The experimental result shows that the stability and wavelength resolution of the FBG demodulation can reach 0.088 pm and 0.030 pm, respectively, using a tunable laser calibrated by the proposed method. We have also compared the demodulation accuracy in the presence or absence of the comb filter, with the result showing that the introduction of the comb filter results to a 15-fold wavelength resolution enhancement.
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Directory of Open Access Journals (Sweden)
Tabitha A Graves
Full Text Available Using multiple detection methods can increase the number, kind, and distribution of individuals sampled, which may increase accuracy and precision and reduce cost of population abundance estimates. However, when variables influencing abundance are of interest, if individuals detected via different methods are influenced by the landscape differently, separate analysis of multiple detection methods may be more appropriate. We evaluated the effects of combining two detection methods on the identification of variables important to local abundance using detections of grizzly bears with hair traps (systematic and bear rubs (opportunistic. We used hierarchical abundance models (N-mixture models with separate model components for each detection method. If both methods sample the same population, the use of either data set alone should (1 lead to the selection of the same variables as important and (2 provide similar estimates of relative local abundance. We hypothesized that the inclusion of 2 detection methods versus either method alone should (3 yield more support for variables identified in single method analyses (i.e. fewer variables and models with greater weight, and (4 improve precision of covariate estimates for variables selected in both separate and combined analyses because sample size is larger. As expected, joint analysis of both methods increased precision as well as certainty in variable and model selection. However, the single-method analyses identified different variables and the resulting predicted abundances had different spatial distributions. We recommend comparing single-method and jointly modeled results to identify the presence of individual heterogeneity between detection methods in N-mixture models, along with consideration of detection probabilities, correlations among variables, and tolerance to risk of failing to identify variables important to a subset of the population. The benefits of increased precision should be weighed
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DEFF Research Database (Denmark)
Weeke, Peter; Andersson, Charlotte; Brendorp, Bente
2008-01-01
Vernakalant (RSD1235) is a novel antiarrhythmic agent for conversion of rapid onset atrial fibrillation (AF). It is an atria-selective multichannel ion blocker (blocks I(Kur), I(Na), I(Ca, L), I(to) and I(Kr)), with a small effect on ventricular repolarization. In clinical Phase II and III studie...... effect, with no reported cases of torsades de pointes in direct relation to vernakalant administration in Phase II and III studies. Overall, there are few reported serious adverse events....
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A method of undifferenced ambiguity resolution for GPS+GLONASS precise point positioning.
Yi, Wenting; Song, Weiwei; Lou, Yidong; Shi, Chuang; Yao, Yibin
2016-05-25
Integer ambiguity resolution is critical for achieving positions of high precision and for shortening the convergence time of precise point positioning (PPP). However, GLONASS adopts the signal processing technology of frequency division multiple access and results in inter-frequency code biases (IFCBs), which are currently difficult to correct. This bias makes the methods proposed for GPS ambiguity fixing unsuitable for GLONASS. To realize undifferenced GLONASS ambiguity fixing, we propose an undifferenced ambiguity resolution method for GPS+GLONASS PPP, which considers the IFCBs estimation. The experimental result demonstrates that the success rate of GLONASS ambiguity fixing can reach 75% through the proposed method. Compared with the ambiguity float solutions, the positioning accuracies of ambiguity-fixed solutions of GLONASS-only PPP are increased by 12.2%, 20.9%, and 10.3%, and that of the GPS+GLONASS PPP by 13.0%, 35.2%, and 14.1% in the North, East and Up directions, respectively.
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Effective extraction method through alkaline hydrolysis for the detection of starch maleate in foods
Directory of Open Access Journals (Sweden)
Chia-Fen Tsai
2015-09-01
Full Text Available A high-performance liquid chromatography (HPLC method was developed for the determination of maleic acid which was released from starch maleate (SM through the alkaline hydrolysis reaction. The proper alkaline hydrolysis conditions and LC separation are reported in this study. The starch samples were treated with 50% methanol for 30 minutes, and then hydrolyzed by 0.5N KOH for 2 hours to release maleic acid. A C18 column and gradient mobile phase consisting of 0.1% phosphoric acid and methanol at a flow rate of 1.0 mL/minute were used for separation. The method showed a good linearity in the range of 0.01–1.0 ìg/mL, with a limit of quantification (LOQ at 10 mg/kg in starch. The recoveries in corn starch, noodle, and fish balls were between 93.9% and 108.4%. The relative standard deviation (RSD of precision was <4.9% (n = 3. This valid method was rapid, sensitive, precise, and suitable for routine monitoring of the illegal adulteration of SM in foods.
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Directory of Open Access Journals (Sweden)
Nishant A. Dafale
2015-02-01
Full Text Available The aim of this study was to develop and validate a simple, sensitive, precise and cost-effective one-level agar diffusion (5+1 bioassay for estimation of potency and bioactivity of Levofloxacin in pharmaceutical preparation which has not yet been reported in any pharmacopoeia. Among 16 microbial strains, Bacillus pumilus ATCC-14884 was selected as the most significant strain against Levofloxacin. Bioassay was optimized by investigating several factors such as buffer pH, inoculums concentration and reference standard concentration. Identification of Levofloxacin in commercial sample Levoflox tablet was done by FTIR spectroscopy. Mean potency recovery value for Levofloxacin in Levoflox tablet was estimated as 100.90%. A validated bioassay method showed linearity (r2=0.988, precision (Interday RSD=1.05%, between analyst RSD=1.02% and accuracy (101.23%, RSD=0.72%. Bioassay was correlated with HPLC using same sample and estimated potencies were 100.90% and 99.37%, respectively. Results show that bioassay is a suitable method for estimation of potency and bioactivity of Levofloxacin pharmaceutical preparations. Keywords: Levofloxacin, Antibiotic resistance, Microbiological bioassay, HPLC, Pharmacopoeia
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Increased efficacy for in-house validation of real-time PCR GMO detection methods.
Scholtens, I M J; Kok, E J; Hougs, L; Molenaar, B; Thissen, J T N M; van der Voet, H
2010-03-01
To improve the efficacy of the in-house validation of GMO detection methods (DNA isolation and real-time PCR, polymerase chain reaction), a study was performed to gain insight in the contribution of the different steps of the GMO detection method to the repeatability and in-house reproducibility. In the present study, 19 methods for (GM) soy, maize canola and potato were validated in-house of which 14 on the basis of an 8-day validation scheme using eight different samples and five on the basis of a more concise validation protocol. In this way, data was obtained with respect to the detection limit, accuracy and precision. Also, decision limits were calculated for declaring non-conformance (>0.9%) with 95% reliability. In order to estimate the contribution of the different steps in the GMO analysis to the total variation variance components were estimated using REML (residual maximum likelihood method). From these components, relative standard deviations for repeatability and reproducibility (RSD(r) and RSD(R)) were calculated. The results showed that not only the PCR reaction but also the factors 'DNA isolation' and 'PCR day' are important factors for the total variance and should therefore be included in the in-house validation. It is proposed to use a statistical model to estimate these factors from a large dataset of initial validations so that for similar GMO methods in the future, only the PCR step needs to be validated. The resulting data are discussed in the light of agreed European criteria for qualified GMO detection methods.
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Validated Spectrophotometric Methods for Simultaneous Determination of Food Colorants and Sweeteners
Directory of Open Access Journals (Sweden)
Fatma Turak
2013-01-01
Full Text Available Two simple spectrophotometric methods have been proposed for simultaneous determination of two colorants (Indigotin and Brilliant Blue and two sweeteners (Acesulfame-K and Aspartame in synthetic mixtures and chewing gums without any prior separation or purification. The first method, derivative spectrophotometry (ZCDS, is based on recording the first derivative curves (for Indigotin, Brillant Blue, and Acesulfame-K and third-derivative curve (for Aspartame and determining each component using the zero-crossing technique. The other method, ratio derivative spectrophotometry (RDS, depends on application ratio spectra of first- and third-derivative spectrophotometry to resolve the interference due to spectral overlapping. Both colorants and sweeteners showed good linearity, with regression coefficients of 0.9992–0.9999. The LOD and LOQ values ranged from 0.05 to 0.33 μgmL−1 and from 0.06 to 0.47 μgmL−1, respectively. The intraday and interday precision tests produced good RSD% values (<0.81%; recoveries ranged from 99.78% to 100.67% for all two methods. The accuracy and precision of the methods have been determined, and the methods have been validated by analyzing synthetic mixtures containing colorants and sweeteners. Two methods were applied for the above combination, and satisfactory results were obtained. The results obtained by applying the ZCDS method were statistically compared with those obtained by the RDS method.
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QUALITATIVE ANALYSIS METHOD OF DETECTION OF WAX CONTENT IN GORENGAN USING SMARTPHONE
Directory of Open Access Journals (Sweden)
Yulia Yulia
2018-05-01
Full Text Available Wax is one of the compounds that can be misused to be added to Gorengan, Indonesian fritter, to keep them crispy. Gorengan containing wax is difficult to identify visually, so a quick and easy method of detecting wax content is required. The purpose of this research is to develop and evaluate the analytical performance of detecting wax content in gorengan using smartphone. Gorengan sample was dissolved with hexane and then added reagent that will give discoloration followed by analysis using smartphone. Some analysis performance parameters were evaluated in terms of linearity and detection limit, qualitative analysis capability, precision, and selectivity test. The developed method was also applied in some gorengan samples. The result shows that the detection of wax content in gorengan can be conducted by using reagent consisting of NaOH, Schift, and curcumin (1 : 2 : 2. Performance analysis shows that the linearity measurement at concentration between 10% and 25% has correlation coefficient (r of 0.9537 with detection limit at concentration of 2% and precision (%RSD less than 3%. The developed method can be applied for the detection of wax content in gorengan in the market.
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International Nuclear Information System (INIS)
Halicz, Ludwik; Lam, J.W.H.; McLaren, J.W.
1994-01-01
A previously reported on-line ICP-MS method for the determination of lead and other trace elements in seawater has been re-examined to determine its suitability for the determination of lead isotope ratios ( 206 Pb/ 207 Pb and 207 Pb/ 208 Pb) in fresh and saline natural waters. A detection limit of 0.9 ng/1 for total lead (for a 5 ml sample) was achieved. Precision of isotope ratio data was 0.2-0.3% RSD at a Pb concentration of 1 μg/l, and was still better than 2% at concentrations of only 10-40 ng/1 in seawater certified reference materials (CRMs). For all three natural water CRMs examined, measured precision was very close to the limit predicted by counting statistics. (Author)
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Comparison of dietary fiber methods for foods.
Heckman, M M; Lane, S A
1981-11-01
In order to evaluate several proposed dietary fiber methods, 12 food samples, representing different food classes, were analyzed by (1) neutral and acid detergent fiber methods (NDF, ADF); (2) NDF with enzyme modification (ENDF); (3) a 2-fraction enzyme method for soluble, insoluble, and total dietary fiber, proposed by Furda (SDF, IDF, TDF); (+) a 1-fraction enzyme method for total dietary fiber proposed by Hellendoorn (TDF). Foods included cereals, fruits, vegetables, pectin, locust bean gum, and soybean polysaccharides. Results show that TDF by Furda and Hellendoorn methods agree reasonably well with literature values by the Southgate method, but ENDF is consistently lower; that ENDF and IDF (Furda method) agree reasonably well; that except for corn corn bran fiber (insoluble) and pectin and locus bean fiber (soluble), all materials have significant fractions of both soluble and insoluble fiber. The Furda method was used on numerous food and ingredient samples and was found to be practical and informative and to have acceptable precision (RSD values of 2.65-7.05%). It is suggested that the Furda (or similar) method be given consideration for the analysis of foods for dietary fiber.
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Simultaneous Quantification of Antidiabetic Agents in Human Plasma by a UPLC-QToF-MS Method.
Directory of Open Access Journals (Sweden)
Mariana Millan Fachi
Full Text Available An ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry method for the simultaneous quantification of chlorpropamide, glibenclamide, gliclazide, glimepiride, metformin, nateglinide, pioglitazone, rosiglitazone, and vildagliptin in human plasma was developed and validated, using isoniazid and sulfaquinoxaline as internal standards. Following plasma protein precipitation using acetonitrile with 1% formic acid, chromatographic separation was performed on a cyano column using gradient elution with water and acetonitrile, both containing 0.1% formic acid. Detection was performed in a quadrupole time-of-flight analyzer, using electrospray ionization operated in the positive mode. Data from validation studies demonstrated that the new method is highly sensitive, selective, precise (RSD 0.99, free of matrix and has no residual effects. The developed method was successfully applied to volunteers' plasma samples. Hence, this method was demonstrated to be appropriate for clinical monitoring of antidiabetic agents.
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Asadian, Simin; Khatony, Alireza; Moradi, Gholamreza; Abdi, Alireza; Rezaei, Mansour
2016-01-01
An accurate determination of body temperature in critically ill patients is a fundamental requirement for initiating the proper process of diagnosis, and also therapeutic actions; therefore, the aim of the study was to assess the accuracy and precision of four noninvasive peripheral methods of temperature measurement compared to the central nasopharyngeal measurement. In this observational prospective study, 237 patients were recruited from the intensive care unit of Imam Ali Hospital of Kermanshah. The patients' body temperatures were measured by four peripheral methods; oral, axillary, tympanic, and forehead along with a standard central nasopharyngeal measurement. After data collection, the results were analyzed by paired t-test, kappa coefficient, receiver operating characteristic curve, and using Statistical Package for the Social Sciences, version 19, software. There was a significant meaningful correlation between all the peripheral methods when compared with the central measurement (Ptemperatures of right and left tympanic membranes and the standard central nasopharyngeal measurement (88%). Paired t-test demonstrated an acceptable precision with forehead (P=0.132), left (P=0.18) and right (P=0.318) tympanic membranes, oral (P=1.00), and axillary (P=1.00) methods. Sensitivity and specificity of both the left and right tympanic membranes were more than for other methods. The tympanic and forehead methods had the highest and lowest accuracy for measuring body temperature, respectively. It is recommended to use the tympanic method (right and left) for assessing a patient's body temperature in the intensive care units because of high accuracy and acceptable precision.
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DEFF Research Database (Denmark)
Johansen, Sys Stybe; Jornil, Jakob
2009-01-01
), methamphetamine (MA), methylenedioxyamphetamine (MDA) and methylenedioxymethamphetamine (MDMA or ecstasy). An intra-day precision of 3-6% RSD and an inter-day precision of 3-17% RSD were observed. Trueness was between 96 % and 106% for the target compounds. The limit of detection ranged from 0.07 to 0.14 ng...
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Directory of Open Access Journals (Sweden)
S. K. Patro
2010-01-01
Full Text Available A simple, rapid and accurate and stability indicating RP-HPLC method was developed for the determination of valsartan in pure and tablet forms. The method showed a linear response for concentrations in the range of 50-175 µg/mL using 0.01 M NH4H2PO4 (pH 3.5 buffer: methanol [50:50] as the mobile phase with detection at 210 nm and a flow rate of 1 mL/min and retention time 11.041 min. The method was statistically validated for accuracy, precision, linearity, ruggedness, robustness, forced degradation, solution stability and selectivity. Quantitative and recovery studies of the dosage form were also carried out and analyzed; the % RSD from recovery studies was found to be less than 1. Due to simplicity, rapidity and accuracy of the method, we believe that the method will be useful for routine quality control analysis.
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Directory of Open Access Journals (Sweden)
Sofia Ahmed
2017-01-01
Full Text Available Introduction: Sulfacetamide sodium is a widely used sulfonamide for ophthalmic infections. Objective: A number of analytical methods have been reported for the analysis of sulfacetamide but they lack the ability to determine both the active drug and its major degradation product, sulfanilamide, simultaneously in a sample. Materials and Methods: In the present study a simple, rapid and economical stability-indicating UV spectrometric method has been validated for the simultaneous assay of sulfacetamide sodium and sulfanilamide in pure form and in ophthalmic preparations. Results: The method has been found to be accurate (recovery 100.03 ±0.589% and precise (RSD 0.587% with detectable and quantifiable limits of 1.67×10–6 M (0.04 mg% and 5.07×10–6 M (0.13 mg%, respectively for the assay of pure sulfacetamide sodium. The method is also found to be accurate and precise to small changes in wavelength, pH and buffer concentration as well as to forced degradation. The study further includes the validation of the method for the assay of pure sulfanilamide in solution, which has been found to be accurate, precise and robust. Conclusion: The results indicate that the proposed two-component spectrometric method is stability-indicating and can be used for the simultaneous assay of both sulfacetamide sodium and sulfanilamide in synthetic mixtures and degraded solutions.
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How precisely can the difference method determine the $\\pi$NN coupling constant?
Loiseau, B
2000-01-01
The Coulomb-like backward peak of the neutron-proton scattering differentialcross section is due to one-pion exchange. Extrapolation to the pion pole ofprecise data should allow to obtain the value of the charged pion-nucleoncoupling constant. This was classically attempted by the use of a smoothphysical function, the Chew function, built from the cross section. To improveaccuracy of such an extrapolation one has introduced a difference method. Itconsists of extrapolating the difference between the Chew function based onexperimental data and that built from a model where the pion-nucleon couplingis exactly known. Here we cross-check to which precision can work this novelextrapolation method by applying it to differences between models and betweendata and models. With good reference models and for the 162 MeV neutron-protonUppsala single energy precise data with a normalisation error of 2.3 , thevalue of the charged pion-nucleon coupling constant is obtained with anaccuracy close to 1.8
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Determination of prilocaine HCl in bulk drug and pharmaceutical formulation by GC-NPD method
Directory of Open Access Journals (Sweden)
Atila Alptug
2013-01-01
Full Text Available The novel analytical method was developed and validated for determination of prilocaine HCl in bulk drug and pharmaceutical formulation by gas chromatography-nitrogen phosphorus detection (GC-NPD. The chromatographic separation was performed using a HP-5MS column. The calibration curve was linear over the concentration range of 40-1000 ng ml-1 with a correlation coefficient of 0.9998. The limits of detection (LOD and quantification (LOQ of method were 10 ng ml-1 and 35 ng ml-1, respectively. The within-day and between-day precision, expressed as the percent relative standard deviation (RSD% was less than 5.0%, and accuracy (percent relative error was better than 4.0%. The developed method can be directly and easily applied for determination of prilocaine HCl in bulk drug and pharmaceutical formulation using internal standard methodology.
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Raghu, M. S.; Basavaiah, K.; Ramesh, P. J.; Abdulrahman, Sameer A. M.; Vinay, K. B.
2012-03-01
A sensitive, precise, and cost-effective UV-spectrophotometric method is described for the determination of pheniramine maleate (PAM) in bulk drug and tablets. The method is based on the measurement of absorbance of a PAM solution in 0.1 N HCl at 264 nm. As per the International Conference on Harmonization (ICH) guidelines, the method was validated for linearity, accuracy, precision, limits of detection (LOD) and quantification (LOQ), and robustness and ruggedness. A linear relationship between absorbance and concentration of PAM in the range of 2-40 μg/ml with a correlation coefficient (r) of 0.9998 was obtained. The LOD and LOQ values were found to be 0.18 and 0.39 μg/ml PAM, respectively. The precision of the method was satisfactory: the value of relative standard deviation (RSD) did not exceed 3.47%. The proposed method was applied successfully to the determination of PAM in tablets with good accuracy and precision. Percentages of the label claims ranged from 101.8 to 102.01% with the standard deviation (SD) from 0.64 to 0.72%. The accuracy of the method was further ascertained by recovery studies via a standard addition procedure. In addition, the forced degradation of PAM was conducted in accordance with the ICH guidelines. Acidic and basic hydrolysis, thermal stress, peroxide, and photolytic degradation were used to assess the stability-indicating power of the method. A substantial degradation was observed during oxidative and alkaline degradations. No degradation was observed under other stress conditions.
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A method for consistent precision radiation therapy
International Nuclear Information System (INIS)
Leong, J.
1985-01-01
Using a meticulous setup procedure in which repeated portal films were taken before each treatment until satisfactory portal verifications were obtained, a high degree of precision in patient positioning was achieved. A fluctuation from treatment to treatment, over 11 treatments, of less than +-0.10 cm (S.D.) for anatomical points inside the treatment field was obtained. This, however, only applies to specific anatomical points selected for this positioning procedure and does not apply to all points within the portal. We have generalized this procedure and have suggested a means by which any target volume can be consistently positioned which may approach this degree of precision. (orig.)
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Biotechnological Methods for Precise Diagnosis of Methicillin Resistance in Staphylococci
Directory of Open Access Journals (Sweden)
Aija Zilevica
2005-04-01
Full Text Available Antimicrobial resistance is one of the most urgent problems in medicine nowadays. The purpose of the study was to investigate the microorganisms resistant to first-line antimicrobials, including gram-positive cocci, particularly the methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococci, the major agents of nosocomial infections. Owing to the multi-resistance of these agents, precise diagnosis of the methicillin resistance of Staphylococci is of greatest clinical importance. It is not enough to use only conventional microbiological diagnostic methods. Biotechnological methods should be also involved. In our studies, the following methicillin resistance identification methods were used: the disk diffusion method, detection of the mecA gene by PCR, E-test and Slidex MRSA test. For molecular typing, PFGL, RAPD tests and detection of the coa gene were used. All the MRS strains were multiresistant to antibacterials. No vancomycine resistance was registered.
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Gunawan, Hendra; Micheldiament, Micheldiament; Mikhailov, Valentin
2008-01-01
http://dx.doi.org/10.17014/ijog.vol3no3.20084The precision of topographic density (Bouguer density) estimation by the Nettleton approach is based on a minimum correlation of Bouguer gravity anomaly and topography. The other method, the Parasnis approach, is based on a minimum correlation of Bouguer gravity anomaly and Bouguer correction. The precision of Bouguer density estimates was investigated by both methods on simple 2D syntetic models and under an assumption free-air anomaly consisting ...
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A High Precision Laser-Based Autofocus Method Using Biased Image Plane for Microscopy
Directory of Open Access Journals (Sweden)
Chao-Chen Gu
2018-01-01
Full Text Available This study designs and accomplishes a high precision and robust laser-based autofocusing system, in which a biased image plane is applied. In accordance to the designed optics, a cluster-based circle fitting algorithm is proposed to calculate the radius of the detecting spot from the reflected laser beam as an essential factor to obtain the defocus value. The experiment conduct on the experiment device achieved novel performance of high precision and robustness. Furthermore, the low demand of assembly accuracy makes the proposed method a low-cost and realizable solution for autofocusing technique.
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International Nuclear Information System (INIS)
Lima, Raquel Franco de Souza; Melo Junior, Germano; Sa, Jaziel Martins
1997-01-01
This work relates the comparison between the results obtained with the two different methods of preparing pressed pastilles from the crushed sample. In this study, the reproductivity is evaluated, aiming to define the method that furnishes a better analytic precision. These analyses were realized with a X-ray fluorescence spectrometer at the Geology Department of the Federal University of Rio Grande do Norte
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Codevilla, Cristiane Franco; Lemos, Alice Machado; Delgado, Leila Schreiner; Rolim, Clarice Madalena Bueno; Adams, Andréa Inês Horn; Bergold, Ana Maria
2011-08-01
A stability-indicating liquid chromatographic method has been developed for the quantitative determination of lodenafil carbonate in tablets. The method employs a Synergi Fusion C18 column (250 × 4.6 mm, i.d., 4 μm particle size), with mobile phase consisting of a mixture of methanol-acetic acid 0.1% pH 4.0 (65:35, v/v) and UV detection at 290 nm, using a photodiode array detector. A linear response (r = 0.9999) was observed in the range of 10-80 μg/mL. The method showed good recoveries (average 100.3%) and also intra and inter-day precision (RSD lodenafil carbonate peak. The method was found to be stability-indicating and due to its simplicity and accuracy can be applied for routine quality control analysis of lodenafil carbonate in tablets.
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A high precision extrapolation method in multiphase-field model for simulating dendrite growth
Yang, Cong; Xu, Qingyan; Liu, Baicheng
2018-05-01
The phase-field method coupling with thermodynamic data has become a trend for predicting the microstructure formation in technical alloys. Nevertheless, the frequent access to thermodynamic database and calculation of local equilibrium conditions can be time intensive. The extrapolation methods, which are derived based on Taylor expansion, can provide approximation results with a high computational efficiency, and have been proven successful in applications. This paper presents a high precision second order extrapolation method for calculating the driving force in phase transformation. To obtain the phase compositions, different methods in solving the quasi-equilibrium condition are tested, and the M-slope approach is chosen for its best accuracy. The developed second order extrapolation method along with the M-slope approach and the first order extrapolation method are applied to simulate dendrite growth in a Ni-Al-Cr ternary alloy. The results of the extrapolation methods are compared with the exact solution with respect to the composition profile and dendrite tip position, which demonstrate the high precision and efficiency of the newly developed algorithm. To accelerate the phase-field and extrapolation computation, the graphic processing unit (GPU) based parallel computing scheme is developed. The application to large-scale simulation of multi-dendrite growth in an isothermal cross-section has demonstrated the ability of the developed GPU-accelerated second order extrapolation approach for multiphase-field model.
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An optimized gossypol high-performance liquid chromatography
Indian Academy of Sciences (India)
The method was shown to be highly reproducible, with precision [as relative standard deviation (RSD)] and accuracy [as relative mean error (RME)] 94%. The results revealed major differences among the different gland varieties or species of cotton, including ...
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International Nuclear Information System (INIS)
Yan Ying; Zhang Chuanbao; Zhao Haijian; Chen Wenxiang; Shen Ziyu; Wang Xiaoru; Chen Dengyun
2007-01-01
A new precise and accurate method for the determination of sodium in serum by inductively coupled plasma mass spectrometry (ICP-MS) was developed. Since 23 Na is the single isotope element, 27 Al is selected as simulated isotope of Na. Al is spiked into serum samples and Na standard solution. 23 Na/ 27 Al ratio in the Na standard solution is determined to assume the natural Na isotope ratio. The serums samples are digested by purified HNO 3 /H 2 O 2 and diluted to get about 0.6 μg·g -1 Al solutions, and the 23 Na/ 27 Al ratios of the serum samples are obtained to calculate the accurate Na concentrations basing on the isotope dilution method. When the simulated isotope dilution method of ICP-MS is applied and Al is selected as the simulated isotope of Na, the precise and accurate Na concentrations in the serums are determined. The inter-day precision of CV<0.13% for one same serum sample is obtained during 3 days 4 measurements. The spike recoveries are between 99.69% and 100.60% for 4 different serum samples and 3 days multi-measurements. The results of measuring standard reference materials of serum sodium are agree with the certified value. The relative difference between 3 days is 0.22%-0.65%, and the relative difference in one bottle is 0.15%-0.44%. The ICP-MS and Al simulated isotope dilution method is proved to be not only precise and accurate, but also quick and convenient for measuring Na in serum. It is promising to be a reference method for precise determination of Na in serum. Since Al is a low cost isotope dilution reagent, the method is possible to be widely applied for serum Na determination. (authors)
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A high precision method for normalization of cross sections
International Nuclear Information System (INIS)
Aguilera R, E.F.; Vega C, J.J.; Martinez Q, E.; Kolata, J.J.
1988-08-01
It was developed a system of 4 monitors and a program to eliminate, in the process of normalization of cross sections, the dependence of the alignment of the equipment and those condition of having centered of the beam. It was carried out a series of experiments with the systems 27 Al + 70, 72, 74, 76 Ge, 35 Cl + 58 Ni, 37 Cl + 58, 60, 62, 64 Ni and ( 81 Br, 109 Rh) + 60 Ni. For these experiments the typical precision of 1% was obtained in the normalization. It is demonstrated theoretical and experimentally the advantage of this method on those that use 1 or 2 monitors. (Author)
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Takabatake, Reona; Akiyama, Hiroshi; Sakata, Kozue; Onishi, Mari; Koiwa, Tomohiro; Futo, Satoshi; Minegishi, Yasutaka; Teshima, Reiko; Mano, Junichi; Furui, Satoshi; Kitta, Kazumi
2011-01-01
A novel real-time PCR-based analytical method was developed for the event-specific quantification of a genetically modified (GM) soybean event; A2704-12. During the plant transformation, DNA fragments derived from pUC19 plasmid were integrated in A2704-12, and the region was found to be A2704-12 specific. The pUC19-derived DNA sequences were used as primers for the specific detection of A2704-12. We first tried to construct a standard plasmid for A2704-12 quantification using pUC19. However, non-specific signals appeared with both qualitative and quantitative PCR analyses using the specific primers with pUC19 as a template, and we then constructed a plasmid using pBR322. The conversion factor (C(f)), which is required to calculate the amount of the genetically modified organism (GMO), was experimentally determined with two real-time PCR instruments, the Applied Biosystems 7900HT and the Applied Biosystems 7500. The determined C(f) values were both 0.98. The quantitative method was evaluated by means of blind tests in multi-laboratory trials using the two real-time PCR instruments. The limit of quantitation for the method was estimated to be 0.1%. The trueness and precision were evaluated as the bias and reproducibility of relative standard deviation (RSD(R)), and the determined bias and RSD(R) values for the method were each less than 20%. These results suggest that the developed method would be suitable for practical analyses for the detection and quantification of A2704-12.
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Tendency for interlaboratory precision in the GMO analysis method based on real-time PCR.
Kodama, Takashi; Kurosawa, Yasunori; Kitta, Kazumi; Naito, Shigehiro
2010-01-01
The Horwitz curve estimates interlaboratory precision as a function only of concentration, and is frequently used as a method performance criterion in food analysis with chemical methods. The quantitative biochemical methods based on real-time PCR require an analogous criterion to progressively promote method validation. We analyzed the tendency of precision using a simplex real-time PCR technique in 53 collaborative studies of seven genetically modified (GM) crops. Reproducibility standard deviation (SR) and repeatability standard deviation (Sr) of the genetically modified organism (GMO) amount (%) was more or less independent of GM crops (i.e., maize, soybean, cotton, oilseed rape, potato, sugar beet, and rice) and evaluation procedure steps. Some studies evaluated whole steps consisting of DNA extraction and PCR quantitation, whereas others focused only on the PCR quantitation step by using DNA extraction solutions. Therefore, SR and Sr for GMO amount (%) are functions only of concentration similar to the Horwitz curve. We proposed S(R) = 0.1971C 0.8685 and S(r) = 0.1478C 0.8424, where C is the GMO amount (%). We also proposed a method performance index in GMO quantitative methods that is analogous to the Horwitz Ratio.
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Determination of d-limonene in adipose tissue by gas chromatography-mass spectrometry
Miller, Jessica A.; Hakim, Iman A.; Thomson, Cynthia; Thompson, Patricia; Chow, H-H. Sherry
2008-01-01
We developed a novel method for analyzing d-limonene levels in adipose tissue. Fat samples were subjected to saponification followed by solvent extraction. d-Limonene in the sample extract was analyzed using gas chromatography-mass spectrometry (GC-MS) with selected ion monitoring. Linear calibration curves were established over the mass range of 79.0-2,529 ng d-limonene per 0.1 grams of adipose tissue. Satisfactory within day precision (RSD 6.7 to 9.6%) and accuracy (% difference of −2.7 to 3.8%) and between day precision (RSD 6.0 to 10.7%) and accuracy (% difference of 1.8 to 2.6%) were achieved. The assay was successfully applied to human fat biopsy samples from a d-limonene feeding trial. PMID:18571481
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Ring, P R; Bostick, J M
2000-04-01
A sensitive and selective high-performance liquid chromatography (HPLC) method was developed for the determination of zolpidem in human plasma. Zolpidem and the internal standard (trazodone) were extracted from human plasma that had been made basic. The basic sample was loaded onto a conditioned Bond Elut C18 cartridge, rinsed with water and eluted with methanol. Forty microliters were then injected onto the LC system. Separation was achieved on a C18 column (150 x 4.6 mm, 5 microm) with a mobile phase composed of acetonitrile:50 mM potassium phosphate monobasic at pH 6.0 (4:6, v/v). Detection was by fluorescence, with excitation at 254 nm and emission at 400 nm. The retention times of zolpidem and internal standard were approximately 4.7 and 5.3 min, respectively. The LC run time was 8 min. The assay was linear in concentration range 1-400 ng/ml for zolpidem in human plasma. The analysis of quality control samples for zolpidem (3, 30, and 300 ng/ml) demonstrated excellent precision with relative standard deviations (RSD) of 3.7, 4.6, and 3.0%, respectively (n = 18). The method was accurate with all intraday (n = 6) and overall (n = 18) mean concentrations within 5.8% from nominal at all quality control sample concentrations. This method was also performed using a Gilson Aspec XL automated sample processor and autoinjector. The samples were manually fortified with internal standard and made basic. The aspec then performed the solid phase extraction and made injections of the samples onto the LC system. Using the automated procedure for analysis, quality control samples for zolpidem (3, 30, and 300 ng/ml) demonstrated acceptable precision with RSD values of 9.0, 4.9, and 5.1%, respectively (n = 12). The method was accurate with all intracurve (n = 4) and overall (n = 12) mean values being less than 10.8% from nominal at all quality control sample concentrations.
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A method of precise profile analysis of diffuse scattering for the KENS pulsed neutrons
International Nuclear Information System (INIS)
Todate, Y.; Fukumura, T.; Fukazawa, H.
2001-01-01
An outline of our profile analysis method, which is now of practical use for the asymmetric KENS pulsed thermal neutrons, are presented. The analysis of the diffuse scattering from a single crystal of D 2 O is shown as an example. The pulse shape function is based on the Ikeda-Carpenter function adjusted for the KENS neutron pulses. The convoluted intensity is calculated by a Monte-Carlo method and the precision of the calculation is controlled. Fitting parameters in the model cross section can be determined by the built-in nonlinear least square fitting procedure. Because this method is the natural extension of the procedure conventionally used for the triple-axis data, it is easy to apply with generality and versatility. Most importantly, furthermore, this method has capability of precise correction of the time shift of the observed peak position which is inevitably caused in the case of highly asymmetric pulses and broad scattering function. It will be pointed out that the accurate determination of true time-of-flight is important especially in the single crystal inelastic experiments. (author)
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D'Ambrosio, Michele
2013-06-15
γ-Oryzanol is an important phytochemical used in pharmaceutical, alimentary and cosmetic preparations. The present article, for the first time, discloses the performances of NP-HPLC in separating γ-oryzanol components and develops a validated method for its routine quantification. The analysis is performed on a cyanopropyl bonded column using the hexane/MTBE gradient elution and UV detection at 325 nm. The method allows: the separation of steryl ferulate, p-coumarate and caffeate esters, the separation of cis- from trans-ferulate isomers, the splitting of steroid moieties into saturated and unsaturated at the side chain. The optimised method provides excellent linear response (R(2)=0.99997), high precision (RSD<1.0%) and satisfactory accuracy (R(∗)=70-86%). In conclusion, the established method presents the details of the procedure and the experimental conditions in order to achieve the required precision and instrumental accuracy. The method is fast and sensitive and it could be a suitable tool for quality assurance and determination of origin. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Janeš Damjan
2014-12-01
Full Text Available Due to severe toxicity of pyrrolizidine alkaloids, their quantification in medicinal products is very important. The idea of this research was to use retrorsine as a surrogate reference compound instead of lycopsamine reference or lycopsamine isolated from comfrey. A method for the analysis of lycopsamine in extracts of comfrey roots was developed and validated, employing thin layer chromatography, derivatisation with Dann-Mattocks reagent followed by densitometric analysis. The new method showed linearity within 0.70 to 7.0 μg of lycopsamine per application of 10 μL of a solution. It has also been proven to be specific and precise (repeatability RSD 2-4 % within the plate. The method was successfully employed for quantification of lycopsamine in comfrey root and comfrey root medicinal products such as ointments.
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Janeš, Damjan; Kreft, Samo
2014-12-01
Due to severe toxicity of pyrrolizidine alkaloids, their quantification in medicinal products is very important. The idea of this research was to use retrorsine as a surrogate reference compound instead of lycopsamine reference or lycopsamine isolated from comfrey. A method for the analysis of lycopsamine in extracts of comfrey roots was developed and validated, employing thin layer chromatography, derivatisation with Dann-Mattocks reagent followed by densitometric analysis. The new method showed linearity within 0.70 to 7.0 μg of lycopsamine per application of 10 μL of a solution. It has also been proven to be specific and precise (repeatability RSD 2-4 % within the plate). The method was successfully employed for quantification of lycopsamine in comfrey root and comfrey root medicinal products such as ointments.
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An LCMS method for the assay of melittin in cosmetic formulations containing bee venom.
Tusiimire, Jonans; Wallace, Jennifer; Dufton, Mark; Parkinson, John; Clements, Carol J; Young, Louise; Park, Jin Kyu; Jeon, Jong Woon; Watson, David G
2015-05-01
There is a growing interest in the potential of bee venom in cosmetics as a rejuvenating agent. Products currently on the market do not specify exactly their content of bee venom (BV). Therefore, we developed a method for the detection and quantification of melittin, as a marker of bee venom content, in selected commercial creams which contained BV according to their marketing claims, in order to gauge the relative quality of such formulations. A quantitative method was achieved following a rigorous extraction procedure involving sonication, liquid-liquid extraction and solid phase extraction since carryover of excipients was found to cause a rapid deterioration in the chromatographic performance. The method employed a standard additions approach using, as spiking standard, purified melittin isolated from bee venom and standardised by quantitative NMR. The aqueous extracts of the spiked creams were analysed by reversed phase LCMS on an LTQ Orbitrap mass spectrometer. The purity of the melittin spiking standard was determined to be 96.0%. The lowest measured mean melittin content in the creams was 3.19 ppm (±1.58 ppm 95% CI) while the highest was 37.21 ppm (±2.01 ppm 95% CI). The method showed adequate linearity (R (2) ≥ 0.98) and a recovery of 87.7-102.2% from a spiked blank cream. An assay precision of <20% RSD was achieved for all but one sample where the RSD value was 27.5%. The method was sensitive enough for use in routine assay of BV-containing cosmetic creams. Differences in the melittin content of the commercial products assayed were nearly tenfold.
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Directory of Open Access Journals (Sweden)
Asadian S
2016-09-01
Full Text Available Simin Asadian,1 Alireza Khatony,1 Gholamreza Moradi,2 Alireza Abdi,1 Mansour Rezaei,3 1Nursing and Midwifery School, Kermanshah University of Medical Sciences, 2Department of Anesthesiology, 3Biostatistics & Epidemiology Department, Kermanshah University of Medical Sciences, Kermanshah, Iran Introduction: An accurate determination of body temperature in critically ill patients is a fundamental requirement for initiating the proper process of diagnosis, and also therapeutic actions; therefore, the aim of the study was to assess the accuracy and precision of four noninvasive peripheral methods of temperature measurement compared to the central nasopharyngeal measurement. Methods: In this observational prospective study, 237 patients were recruited from the intensive care unit of Imam Ali Hospital of Kermanshah. The patients’ body temperatures were measured by four peripheral methods; oral, axillary, tympanic, and forehead along with a standard central nasopharyngeal measurement. After data collection, the results were analyzed by paired t-test, kappa coefficient, receiver operating characteristic curve, and using Statistical Package for the Social Sciences, version 19, software. Results: There was a significant meaningful correlation between all the peripheral methods when compared with the central measurement (P<0.001. Kappa coefficients showed good agreement between the temperatures of right and left tympanic membranes and the standard central nasopharyngeal measurement (88%. Paired t-test demonstrated an acceptable precision with forehead (P=0.132, left (P=0.18 and right (P=0.318 tympanic membranes, oral (P=1.00, and axillary (P=1.00 methods. Sensitivity and specificity of both the left and right tympanic membranes were more than for other methods. Conclusion: The tympanic and forehead methods had the highest and lowest accuracy for measuring body temperature, respectively. It is recommended to use the tympanic method (right and left for
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An Analytical Method to Measure Free-Water Tritium in Foods using Azeotropic Distillation.
Soga, Keisuke; Kamei, Toshiyuki; Hachisuka, Akiko; Nishimaki-Mogami, Tomoko
2016-01-01
A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant has raised concerns about the discharge of contaminated water containing tritium ((3)H) from the nuclear power plant into the environment and into foods. In this study, we explored convenient analytical methods to measure free-water (3)H in foods using a liquid scintillation counting and azeotropic distillation method. The detection limit was 10 Bq/L, corresponding to about 0.01% of 1 mSv/year. The (3)H recoveries were 85-90% in fruits, vegetables, meats and fishes, 75-85% in rice and cereal crops, and less than 50% in sweets containing little water. We found that, in the case of sweets, adding water to the sample before the azeotropic distillation increased the recovery and precision. Then, the recoveries reached more than 75% and RSD was less than 10% in all food categories (13 kinds). Considering its sensitivity, precision and simplicity, this method is practical and useful for (3)H analysis in various foods, and should be suitable for the safety assessment of foods. In addition, we examined the level of (3)H in foods on the Japanese market. No (3)H radioactivity was detected in any of 42 analyzed foods.
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Precision of a new bedside method for estimation of the circulating blood volume
DEFF Research Database (Denmark)
Christensen, P; Eriksen, B; Henneberg, S W
1993-01-01
The present study is a theoretical and experimental evaluation of a modification of the carbon monoxide method for estimation of the circulating blood volume (CBV) with respect to the precision of the method. The CBV was determined from measurements of the CO-saturation of hemoglobin before and a......, determination of CBV can be performed with an amount of CO that gives rise to a harmless increase in the carboxyhemoglobin concentration.(ABSTRACT TRUNCATED AT 250 WORDS)...
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Abdel-Aziz, Omar; Hussien, Emad M; El Kosasy, Amira M; Ahmed, Neven
2016-07-01
Six simple, accurate, reproducible, and selective derivative spectrophotometric and chemometric methods have been developed and validated for the determination of levamisole HCl (Lev) either alone or in combination with closantel sodium (Clo) in the pharmaceutical dosage form. Lev was determined by first-derivative, first-derivative ratio, and mean-centering methods by measuring the peak amplitude at 220.8, 243.8, and 210.4 nm, respectively. The methods were linear over the concentration range 2.0-10.0 μg/mL Lev. The methods exhibited a high accuracy, with recovery data within ±1.9% and RSD <1.3% (n = 9) for the determination of Lev in the presence of Clo. Fortunately, Lev showed no significant UV absorbance at 370.6 nm, which allowed the determination of Clo over the concentration range 16.0-80.0 μg/mL using zero-order spectra, with a high precision (RSD <1.5%, n = 9). Furthermore, principal component regression and partial least-squares with optimized parameters were used for the determination of Lev in the presence of Clo. The recovery was within ±1%, with RSD <1.0% (n = 9) and root mean square error of prediction ≤1.0. The proposed methods were validated according to the International Conference on Harmonization guidelines. The proposed methods were used in the determination of Lev and Clo in a binary mixture and a pharmaceutical formulation, with high accuracy and precision.
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A high precision method for quantitative measurements of reactive oxygen species in frozen biopsies.
Directory of Open Access Journals (Sweden)
Kirsti Berg
Full Text Available OBJECTIVE: An electron paramagnetic resonance (EPR technique using the spin probe cyclic hydroxylamine 1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine (CMH was introduced as a versatile method for high precision quantification of reactive oxygen species, including the superoxide radical in frozen biological samples such as cell suspensions, blood or biopsies. MATERIALS AND METHODS: Loss of measurement precision and accuracy due to variations in sample size and shape were minimized by assembling the sample in a well-defined volume. Measurement was carried out at low temperature (150 K using a nitrogen flow Dewar. The signal intensity was measured from the EPR 1st derivative amplitude, and related to a sample, 3-carboxy-proxyl (CP• with known spin concentration. RESULTS: The absolute spin concentration could be quantified with a precision and accuracy better than ±10 µM (k = 1. The spin concentration of samples stored at -80°C could be reproduced after 6 months of storage well within the same error estimate. CONCLUSION: The absolute spin concentration in wet biological samples such as biopsies, water solutions and cell cultures could be quantified with higher precision and accuracy than normally achievable using common techniques such as flat cells, tissue cells and various capillary tubes. In addition; biological samples could be collected and stored for future incubation with spin probe, and also further stored up to at least six months before EPR analysis, without loss of signal intensity. This opens for the possibility to store and transport incubated biological samples with known accuracy of the spin concentration over time.
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International Nuclear Information System (INIS)
Cristiano, Barbara Fernandes G.; Dias, Fabio C.; Barros, Pedro D. de; Araujo, Radier Mario S. de; Delgado, Jose Ubiratan; Silva, Jose Wanderley S. da; Lopes, Ricardo T.
2011-01-01
The method of high precision potentiometric titration is widely used in the certification and characterization of uranium compounds. In order to reduce the analysis and diminish the influence if the annalist, a semi-automatic version of the method was developed at the safeguards laboratory of the CNEN-RJ, Brazil. The method was applied with traceability guaranteed by use of primary standard of potassium dichromate. The standard uncertainty combined in the determination of concentration of total uranium was of the order of 0.01%, which is better related to traditionally methods used by the nuclear installations which is of the order of 0.1%
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Bassanese, Danielle N; Conlan, Xavier A; Barnett, Neil W; Stevenson, Paul G
2015-05-01
This paper explores the analytical figures of merit of two-dimensional high-performance liquid chromatography for the separation of antioxidant standards. The cumulative two-dimensional high-performance liquid chromatography peak area was calculated for 11 antioxidants by two different methods--the areas reported by the control software and by fitting the data with a Gaussian model; these methods were evaluated for precision and sensitivity. Both methods demonstrated excellent precision in regards to retention time in the second dimension (%RSD below 1.16%) and cumulative second dimension peak area (%RSD below 3.73% from the instrument software and 5.87% for the Gaussian method). Combining areas reported by the high-performance liquid chromatographic control software displayed superior limits of detection, in the order of 1 × 10(-6) M, almost an order of magnitude lower than the Gaussian method for some analytes. The introduction of the countergradient eliminated the strong solvent mismatch between dimensions, leading to a much improved peak shape and better detection limits for quantification. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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A novel and rapid microbiological assay for ciprofloxacin hydrochloride
Directory of Open Access Journals (Sweden)
Edith Cristina Laignier Cazedey
2013-10-01
Full Text Available The present work reports a simple, fast and sensitive microbiological assay applying the turbidimetric method for the determination of ciprofloxacin hydrochloride (CIPRO HCl in ophthalmic solutions. The validation method yielded good results and included excellent linearity, precision, accuracy and specificity. The bioassay is based on the inhibitory effect of CIPRO HCl upon the strain of Staphylococcus epidermidis ATCC 12228 used as the test microorganism. The results were treated statistically by analysis of variance (ANOVA and were found to be linear (r=0.9994, in the range of 14.0â56.0 µg/mL, precise (intraday RSD%=2.06; interday RSD%=2.30 and accurate (recovery=99.71%. The turbidimetric assay was compared to the UV spectrophotometric and HPLC methods for the same drug. The turbidimetric bioassay described on this paper for determination of ciprofloxacin hydrochloride in ophthalmic solution is an alternative to the physicochemical methods disclosed in the literature and can be used in quality control routine. Keywords: Antibiotics, Fluoroquinolones, Ciprofloxacin hydrochloride, Quality control, Microbiological assay, Turbidimetric method
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Using cold deformation methods in flow-production of steel high precision shaped sections
International Nuclear Information System (INIS)
Zajtsev, M.L.; Makhnev, I.F.; Shkurko, I.I.
1975-01-01
A final size with a preset tolerance and a required surface finish of steel high-precision sections could be achieved by a cold deformation of hot-rolled ingots-by drawing through dismountable, monolith or roller-type drawing tools or by cold rolling in roller dies. The particularities of the both techniques are compared as regards a number of complicated shaped sections and the advantages of cold rolling are showna more uniform distribution of deformations (strain hardening) across the section, that is a greater margin of plasticity with the same reductions, the less number of the operations required. Rolling is recommended in all the cases when possible as regards the section shape and the bulk volume. The rolling-mill for the calibration of high-precision sections should have no less than two shafts (so that the size could be controlled in both directions) and arrangements to withstand high axial stresses on the rollers (the stresses appearing during rolling in skew dies). When manufacturing precise shaped sections by the cold rolling method the operations are less plentiful than in the cold drawing manufacturing
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Bannerman, J A; Costamagna, A C; McCornack, B P; Ragsdale, D W
2015-06-01
Generalist natural enemies play an important role in controlling soybean aphid, Aphis glycines (Hemiptera: Aphididae), in North America. Several sampling methods are used to monitor natural enemy populations in soybean, but there has been little work investigating their relative bias, precision, and efficiency. We compare five sampling methods: quadrats, whole-plant counts, sweep-netting, walking transects, and yellow sticky cards to determine the most practical methods for sampling the three most prominent species, which included Harmonia axyridis (Pallas), Coccinella septempunctata L. (Coleoptera: Coccinellidae), and Orius insidiosus (Say) (Hemiptera: Anthocoridae). We show an important time by sampling method interaction indicated by diverging community similarities within and between sampling methods as the growing season progressed. Similarly, correlations between sampling methods for the three most abundant species over multiple time periods indicated differences in relative bias between sampling methods and suggests that bias is not consistent throughout the growing season, particularly for sticky cards and whole-plant samples. Furthermore, we show that sticky cards produce strongly biased capture rates relative to the other four sampling methods. Precision and efficiency differed between sampling methods and sticky cards produced the most precise (but highly biased) results for adult natural enemies, while walking transects and whole-plant counts were the most efficient methods for detecting coccinellids and O. insidiosus, respectively. Based on bias, precision, and efficiency considerations, the most practical sampling methods for monitoring in soybean include walking transects for coccinellid detection and whole-plant counts for detection of small predators like O. insidiosus. Sweep-netting and quadrat samples are also useful for some applications, when efficiency is not paramount. © The Authors 2015. Published by Oxford University Press on behalf of
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Zhao, Yinzhi; Zhang, Peng; Guo, Jiming; Li, Xin; Wang, Jinling; Yang, Fei; Wang, Xinzhe
2018-06-20
Due to the great influence of multipath effect, noise, clock and error on pseudorange, the carrier phase double difference equation is widely used in high-precision indoor pseudolite positioning. The initial position is determined mostly by the known point initialization (KPI) method, and then the ambiguities can be fixed with the LAMBDA method. In this paper, a new method without using the KPI to achieve high-precision indoor pseudolite positioning is proposed. The initial coordinates can be quickly obtained to meet the accuracy requirement of the indoor LAMBDA method. The detailed processes of the method follows: Aiming at the low-cost single-frequency pseudolite system, the static differential pseudolite system (DPL) method is used to obtain the low-accuracy positioning coordinates of the rover station quickly. Then, the ambiguity function method (AFM) is used to search for the coordinates in the corresponding epoch. The real coordinates obtained by AFM can meet the initial accuracy requirement of the LAMBDA method, so that the double difference carrier phase ambiguities can be correctly fixed. Following the above steps, high-precision indoor pseudolite positioning can be realized. Several experiments, including static and dynamic tests, are conducted to verify the feasibility of the new method. According to the results of the experiments, the initial coordinates with the accuracy of decimeter level through the DPL can be obtained. For the AFM part, both a one-meter search scope and two-centimeter or four-centimeter search steps are used to ensure the precision at the centimeter level and high search efficiency. After dealing with the problem of multiple peaks caused by the ambiguity cosine function, the coordinate information of the maximum ambiguity function value (AFV) is taken as the initial value of the LAMBDA, and the ambiguities can be fixed quickly. The new method provides accuracies at the centimeter level for dynamic experiments and at the millimeter
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Niopas, Ioannis; Daftsios, Athanasios C
2002-05-15
Glibenclamide is a potent second generation oral sulfonylurea antidiabetic agent widely used for the treatment of type II diabetes melitus. A rapid, sensitive, precise, accurate and specific HPLC assay for the determination of glibenclamide in human plasma was developed and validated. After addition of flufenamic acid as internal standard, the analytes were isolated from human plasma by liquid-liquid extraction. The method was linear in the 10-400 ng/ml concentration range (r > 0.999). Recovery for glibenclamide was greater than 91.5% and for internal standard was 93.5%. Within-day and between-day precision, expressed as the relative standard deviation (RSD%), ranged from 1.4 to 5.9% and 5.8 to 6.6%, respectively. Assay accuracy was better than 93.4%. The assay was used to estimate the pharmacokinetics of glibenclamide after oral administration of a 5 mg tablet of glibenclamide to 18 healthy volunteers.
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Accuracy, Precision, Ease-Of-Use, and Cost of Methods to Test Ebola-Relevant Chlorine Solutions.
Directory of Open Access Journals (Sweden)
Emma Wells
Full Text Available To prevent transmission in Ebola Virus Disease (EVD outbreaks, it is recommended to disinfect living things (hands and people with 0.05% chlorine solution and non-living things (surfaces, personal protective equipment, dead bodies with 0.5% chlorine solution. In the current West African EVD outbreak, these solutions (manufactured from calcium hypochlorite (HTH, sodium dichloroisocyanurate (NaDCC, and sodium hypochlorite (NaOCl have been widely used in both Ebola Treatment Unit and community settings. To ensure solution quality, testing is necessary, however test method appropriateness for these Ebola-relevant concentrations has not previously been evaluated. We identified fourteen commercially-available methods to test Ebola-relevant chlorine solution concentrations, including two titration methods, four DPD dilution methods, and six test strips. We assessed these methods by: 1 determining accuracy and precision by measuring in quintuplicate five different 0.05% and 0.5% chlorine solutions manufactured from NaDCC, HTH, and NaOCl; 2 conducting volunteer testing to assess ease-of-use; and, 3 determining costs. Accuracy was greatest in titration methods (reference-12.4% error compared to reference method, then DPD dilution methods (2.4-19% error, then test strips (5.2-48% error; precision followed this same trend. Two methods had an accuracy of <10% error across all five chlorine solutions with good precision: Hach digital titration for 0.05% and 0.5% solutions (recommended for contexts with trained personnel and financial resources, and Serim test strips for 0.05% solutions (recommended for contexts where rapid, inexpensive, and low-training burden testing is needed. Measurement error from test methods not including pH adjustment varied significantly across the five chlorine solutions, which had pH values 5-11. Volunteers found test strip easiest and titration hardest; costs per 100 tests were $14-37 for test strips and $33-609 for titration
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Directory of Open Access Journals (Sweden)
Marina Venzon Antunes
2011-01-01
Full Text Available A method for quantifying urinary 2,5-hexanedione was optimized and validated. Urine samples were hydrolyzed and derivatized with 2,4-dinitrophenylhydrazine. The analyte was separated in a high performance liquid chromatography system with a diode array detector, using a C18 column (150 x 4.6 mm, p.d. 5 µm and a mobile phase composed of phosphate buffer pH 2.3:acetonitrile (40:60, v/v, at a flow rate of 1 mL/min. The chromatograms were monitored at 334 nm. Retention time was 7.3 minutes. Main validation parameters were: coefficient of determination: 0.9994, accuracy: 96 to 107%; intra-assay precision (RSD: 3.08 to 6.72%; inter-assay precision (RSD: 2.54 to 8.17% and limit of quantitation of 0.19 µg/mL.
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Ma, Lin
2017-11-01
This paper develops a method for precisely determining the tension of an inclined cable with unknown boundary conditions. First, the nonlinear motion equation of an inclined cable is derived, and a numerical model of the motion of the cable is proposed using the finite difference method. The proposed numerical model includes the sag-extensibility, flexural stiffness, inclination angle and rotational stiffness at two ends of the cable. Second, the influence of the dynamic parameters of the cable on its frequencies is discussed in detail, and a method for precisely determining the tension of an inclined cable is proposed based on the derivatives of the eigenvalues of the matrices. Finally, a multiparameter identification method is developed that can simultaneously identify multiple parameters, including the rotational stiffness at two ends. This scheme is applicable to inclined cables with varying sag, varying flexural stiffness and unknown boundary conditions. Numerical examples indicate that the method provides good precision. Because the parameters of cables other than tension (e.g., the flexural stiffness and rotational stiffness at the ends) are not accurately known in practical engineering, the multiparameter identification method could further improve the accuracy of cable tension measurements.
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Scanu, Roberta; Spano, Nadia; Panzanelli, Angelo; Pilo, Maria I; Piu, Paola C; Sanna, Gavino; Tapparo, Andrea
2005-10-07
Two rapid and direct chromatographic methods based on reverse phase-high performance liquid chromatography (RP-HPLC) and ion chromatography (IC) were developed for the determination of homogentisic acid (HA) in honey. This is the marker of the botanic origin of strawberry tree honey. The methods were validated and tested using 22 samples from Sardinia, Italy. The IC method is faster than the RP-HPLC one (6 min versus 13 min of total run), but it is slightly less sensitive (the limit of detection (LOD), is 26 mg kg(-1) versus 15 mg kg(-1)) and reproducible (relative standard deviation, RSD, of 10.4 and 4.4%, respectively). The whole dataset of validation parameters allows both the proposed methods to be considered as bias-free (by recovery tests, comparison of analytical results of the two independent methods and analysis of a synthetic sample) and precise (both the techniques show a repeatability better than 2% repeatability in the range between 70 and 600 mg kg(-1)).
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Soil chemical sensor and precision agricultural chemical delivery system and method
Colburn, Jr., John W.
1991-01-01
A real time soil chemical sensor and precision agricultural chemical delivery system includes a plurality of ground-engaging tools in association with individual soil sensors which measure soil chemical levels. The system includes the addition of a solvent which rapidly saturates the soil/tool interface to form a conductive solution of chemicals leached from the soil. A multivalent electrode, positioned within a multivalent frame of the ground-engaging tool, applies a voltage or impresses a current between the electrode and the tool frame. A real-time soil chemical sensor and controller senses the electrochemical reaction resulting from the application of the voltage or current to the leachate, measures it by resistivity methods, and compares it against pre-set resistivity levels for substances leached by the solvent. Still greater precision is obtained by calibrating for the secondary current impressed through solvent-less soil. The appropriate concentration is then found and the servo-controlled delivery system applies the appropriate amount of fertilizer or agricultural chemicals substantially in the location from which the soil measurement was taken.
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Brooks, Larry M; Kuhlman, Benjamin J; McKesson, Doug W; McCloskey, Leo
2013-01-01
The poor interoperability of anthocyanin glycosides measurements by two pH differential methods is documented. Adams-Harbertson, which was proposed for commercial winemaking, was compared to AOAC Official Method 2005.02 for wine. California bottled wines (Pinot Noir, Merlot, and Cabernet Sauvignon) were assayed in a collaborative study (n=105), which found mean precision of Adams-Harbertson winery versus reference measurements to be 77 +/- 20%. Maximum error is expected to be 48% for Pinot Noir, 42% for Merlot, and 34% for Cabernet Sauvignon from reproducibility RSD. Range of measurements was actually 30 to 91% for Pinot Noir. An interoperability study (n=30) found Adams-Harbertson produces measurements that are nominally 150% of the AOAC pH differential method. Large analytical chemistry differences are: AOAC method uses Beer-Lambert equation and measures absorbance at pH 1.0 and 4.5, proposed a priori by Flueki and Francis; whereas Adams-Harbertson uses "universal" standard curve and measures absorbance ad hoc at pH 1.8 and 4.9 to reduce the effects of so-called co-pigmentation. Errors relative to AOAC are produced by Adams-Harbertson standard curve over Beer-Lambert and pH 1.8 over pH 1.0. The study recommends using AOAC Official Method 2005.02 for analysis of wine anthocyanin glycosides.
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Wang, Guiqin; Zeng, Yuling; Xu, Jifeng; Liu, Wengui
2018-03-09
We report a new method for calibrating the current gain of 10 13 Ω amplifiers in both positive and negative mode used in thermal ionisation mass spectrometry (TIMS). This method uses any isotopic standard or sample to calibrate the gain factor as long as it can produce a stable current signal. It is simpler and more flexible than that recommended by Thermo-Fisher (the manufacture of the TIMS). In these analyses, the gains of five 10 13 Ω amplifiers were assessed. The precision of gain factors was better than 100 ppm (2 RSD) in a day, and the long term reproducibility was better than 300 ppm (2 RSD) within 2 - 8 months. After a gain was calibrated, the ratio accuracy and precision in the positive mode for 87 Sr/ 88 Sr of NIST 987 Sr and 143 Nd/ 144 Nd of La Jolla Nd were 0.710242 ± 60 (2 SD, n = 14) and 0.511842 ± 10 (2 SD, n = 22), respectively, at intensities of 88 Sr 0.3 V and 142 Nd 0.4 V, while in the negative mode for 187 Os/ 188 Os of Merck Os was 0.120229± 34 (2 SD, n = 23) at an intensity of 187 OsO 3 0.01 mV. In addition, a difference in the gain factors between the negative mode TIMS (NTIMS) and positive mode TIMS (PTIMS) has been recognized. The values of the gain factor for NTIMS and PTIMS show a deviation of 0.54% on the Triton and 0.31% on the Triton Plus TIMS in this study; therefore, gain calibration should be carried out on both NTIMS and PTIMS. Moreover, a bias of ~ 1.5×10 -5 between H and L Faraday cups for the same 10 13 Ω amplifier has been detected, hinting that the efficiency of different Faraday cups may affect the gain factors, which can be eliminated through the new method of "cross-calibration" discribed in this study. This article is protected by copyright. All rights reserved.
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Hollands, Wendy J; Voorspoels, Stefan; Jacobs, Griet; Aaby, Kjersti; Meisland, Ane; Garcia-Villalba, Rocio; Tomas-Barberan, Francisco; Piskula, Mariusz K; Mawson, Deborah; Vovk, Irena; Needs, Paul W; Kroon, Paul A
2017-04-28
There is a lack of data for individual oligomeric procyanidins in apples and apple extracts. Our aim was to develop, validate and evaluate an analytical method for the separation, identification and quantification of monomeric and oligomeric flavanols in apple extracts. To achieve this, we prepared two types of flavanol extracts from freeze-dried apples; one was an epicatechin-rich extract containing ∼30% (w/w) monomeric (-)-epicatechin which also contained oligomeric procyanidins (Extract A), the second was an oligomeric procyanidin-rich extract depleted of epicatechin (Extract B). The parameters considered for method optimisation were HPLC columns and conditions, sample heating, mass of extract and dilution volumes. The performance characteristics considered for method validation included standard linearity, method sensitivity, precision and trueness. Eight laboratories participated in the method evaluation. Chromatographic separation of the analytes was best achieved utilizing a Hilic column with a binary mobile phase consisting of acidic acetonitrile and acidic aqueous methanol. The final method showed linearity for epicatechin in the range 5-100μg/mL with a correlation co-efficient >0.999. Intra-day and inter-day precision of the analytes ranged from 2 to 6% and 2 to 13% respectively. Up to dp3, trueness of the method was >95% but decreased with increasing dp. Within laboratory precision showed RSD values <5 and 10% for monomers and oligomers, respectively. Between laboratory precision was 4 and 15% (Extract A) and 7 and 30% (Extract B) for monomers and oligomers, respectively. An analytical method for the separation, identification and quantification of procyanidins in an apple extract was developed, validated and assessed. The results of the inter-laboratory evaluation indicate that the method is reliable and reproducible. Copyright © 2017. Published by Elsevier B.V.
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Vestergaard, Rikke Falsig; Søballe, Kjeld; Hasenkam, John Michael; Stilling, Maiken
2018-05-18
A small, but unstable, saw-gap may hinder bone-bridging and induce development of painful sternal dehiscence. We propose the use of Radiostereometric Analysis (RSA) for evaluation of sternal instability and present a method validation. Four bone analogs (phantoms) were sternotomized and tantalum beads were inserted in each half. The models were reunited with wire cerclage and placed in a radiolucent separation device. Stereoradiographs (n = 48) of the phantoms in 3 positions were recorded at 4 imposed separation points. The accuracy and precision was compared statistically and presented as translations along the 3 orthogonal axes. 7 sternotomized patients were evaluated for clinical RSA precision by double-examination stereoradiographs (n = 28). In the phantom study, we found no systematic error (p > 0.3) between the three phantom positions, and precision for evaluation of sternal separation was 0.02 mm. Phantom accuracy was mean 0.13 mm (SD 0.25). In the clinical study, we found a detection limit of 0.42 mm for sternal separation and of 2 mm for anterior-posterior dislocation of the sternal halves for the individual patient. RSA is a precise and low-dose image modality feasible for clinical evaluation of sternal stability in research. ClinicalTrials.gov Identifier: NCT02738437 , retrospectively registered.
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Precision and Accuracy of k0-NAA Method for Analysis of Multi Elements in Reference Samples
International Nuclear Information System (INIS)
Sri-Wardani
2004-01-01
Accuracy and precision of k 0 -NAA method could determine in the analysis of multi elements contained in reference samples. The analyzed results of multi elements in SRM 1633b sample were obtained with optimum results in bias of 20% but it is in a good accuracy and precision. The analyzed results of As, Cd and Zn in CCQM-P29 rice flour sample were obtained with very good result in bias of 0.5 - 5.6%. (author)
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New method for evaluating astringency in red wine.
Llaudy, María C; Canals, Roser; Canals, Joan-Miquel; Rozés, Nicolas; Arola, Lluís; Zamora, Fernando
2004-02-25
Astringency is an important sensory attribute of red wine. It is usually estimated by tasting and is subject to a certain subjectivity. It can also be estimated by using the gelatin index. This procedure is not very reproducible because there are many gelatins on the market with a heterogeneous composition. Furthermore, the gelatin index determines procyanidin concentration by acid hydrolysis that gives only an approximate result. This paper proposes a new and reproducible method that determines astringency by using ovalbumin as the precipitation agent and tannic acid solutions as standards. Statistical analysis of the results indicates that this method is more reproducible (RSD = 5%) than the gelatin index (RSD = 12%) and correlates better with sensorial analysis.
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Accuracy of complete-arch dental impressions: a new method of measuring trueness and precision.
Ender, Andreas; Mehl, Albert
2013-02-01
A new approach to both 3-dimensional (3D) trueness and precision is necessary to assess the accuracy of intraoral digital impressions and compare them to conventionally acquired impressions. The purpose of this in vitro study was to evaluate whether a new reference scanner is capable of measuring conventional and digital intraoral complete-arch impressions for 3D accuracy. A steel reference dentate model was fabricated and measured with a reference scanner (digital reference model). Conventional impressions were made from the reference model, poured with Type IV dental stone, scanned with the reference scanner, and exported as digital models. Additionally, digital impressions of the reference model were made and the digital models were exported. Precision was measured by superimposing the digital models within each group. Superimposing the digital models on the digital reference model assessed the trueness of each impression method. Statistical significance was assessed with an independent sample t test (α=.05). The reference scanner delivered high accuracy over the entire dental arch with a precision of 1.6 ±0.6 µm and a trueness of 5.3 ±1.1 µm. Conventional impressions showed significantly higher precision (12.5 ±2.5 µm) and trueness values (20.4 ±2.2 µm) with small deviations in the second molar region (PDigital impressions were significantly less accurate with a precision of 32.4 ±9.6 µm and a trueness of 58.6 ±15.8µm (Pdigital models were visible across the entire dental arch. The new reference scanner is capable of measuring the precision and trueness of both digital and conventional complete-arch impressions. The digital impression is less accurate and shows a different pattern of deviation than the conventional impression. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.
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Dantan, N; Frenzel, W; Küppers, S
2000-05-31
Flow injection methods utilising the Karl Fischer (KF) reaction with spectrophotometric and potentiometric detection are described for the determination of the trace water content in various organic solvents. Optimisation of the methods resulted in an accessible (linear) working range of 0.01-0.2% water for many solvents studied with a typical precision of 1-2% R.S.D. Only 50 mul of organic solvent was injected and the sampling frequency was about 120 samples per h. Since the slopes of the calibration curves were different for different solvents appropriate calibration was required. Problems associated with spectrophotometric detection and caused by refractive index changes were pointed out and a nested-loop configuration was proposed to overcome this kind of interference. The potentiometric method with a novel flow-through detector cell was shown to surpass the performance of spectrophotometric detection in any respect. The characteristics of the procedures developed made them well applicable for on-line monitoring of technical solvent distillations in an industrial plant.
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Karami-Osboo, Rouhollah; Miri, Ramin; Javidnia, Katayoun; Kobarfard, Farzad
2016-01-01
The antibiotic residues in milk are a well-known serious problem and pose several health hazards to consumers. We have described a simple, rapid, and inexpensive DLLME-HPLC/UV technique for the extraction of chloramphenicol and florfenicol residues in milk samples. Under the optimum conditions, linearity of the method was observed over the range 0.02-0.85 µg/L with correlation coefficients > 0.999. The proposed method has been found to have a good limit of detection (signal to noise ratio = 3) for chloramphenicol (12.5 µg/Kg) and florfenicol (12.2 µg/Kg), and precision with relative standard deviation values under 15% (RSD, n = 3). Good recoveries (69.1-79.4%) were obtained for the extraction of the target analytes in milk samples. This simple and economic method has been applied for analyses of 15 real milk samples. Among all samples only one of them was contaminated to florfenicol; 62.4 µg/Kg and contamination to chloramphenicol was not detected.
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Zhou, Yu; Wang, Tianyi; Dai, Bing; Li, Wenjun; Wang, Wei; You, Chengwu; Wang, Kejia; Liu, Jinsong; Wang, Shenglie; Yang, Zhengang
2018-02-01
Inspired by the extensive application of terahertz (THz) imaging technologies in the field of aerospace, we exploit a THz frequency modulated continuous-wave imaging method with continuous wavelet transform (CWT) algorithm to detect a multilayer heat shield made of special materials. This method uses the frequency modulation continuous-wave system to catch the reflected THz signal and then process the image data by the CWT with different basis functions. By calculating the sizes of the defects area in the final images and then comparing the results with real samples, a practical high-precision THz imaging method is demonstrated. Our method can be an effective tool for the THz nondestructive testing of composites, drugs, and some cultural heritages.
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Directory of Open Access Journals (Sweden)
Kedar Kalyani Abhimanyu
2017-06-01
Full Text Available In present study HPTLC method was developed and validated for the determination of friedelin in Putranjiva roxburghii Wall (family: Euphorbiaceae leaf, bark extract and in polyherbal formulations. Analysis of samples were performed on TLC aluminium precoated plate (60 F254 by using mobile phase toluene: chloroform (9:1 v/v. Plate was derivatized with vanillin sulphuric acid and scanned at 580 nm. Developed method found to give compact spot for friedelin at Rf value 0.43 ± 0.01. The method was validated using International Council for Harmonization (ICH guidelines including linearity, precision, accuracy, and robustness. Friedelin was found to be present in leaf extract of Putranjiva roxburghii Wall (0.003% w/w, in bark (0.04% w/w, formulation 1 (0.002% w/w and formulation 2 (0.035% w/w. A good linearity relationship was found to be (100–500 ng spot−1 with correlation coefficient (r2 value of 0.9892 for friedelin. Limit of detection and limit of quantitation was found to be 32.15, 97.44 ng/band respectively for friedelin. The developed method was found to be accurate and precise with 0.78%, 0.9% (%RSD for interday and intraday precision. Accuracy of the method was performed by recovery studies at three different concentration levels and the average percentage recovery was found to be 98.55% for friedelin. The proposed method for the quantitation of friedelin was found to be simple, specific, accurate and robust in Putranjiva roxburghii Wall and polyherbal formulations.
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Precision digital control systems
Vyskub, V. G.; Rozov, B. S.; Savelev, V. I.
This book is concerned with the characteristics of digital control systems of great accuracy. A classification of such systems is considered along with aspects of stabilization, programmable control applications, digital tracking systems and servomechanisms, and precision systems for the control of a scanning laser beam. Other topics explored are related to systems of proportional control, linear devices and methods for increasing precision, approaches for further decreasing the response time in the case of high-speed operation, possibilities for the implementation of a logical control law, and methods for the study of precision digital control systems. A description is presented of precision automatic control systems which make use of electronic computers, taking into account the existing possibilities for an employment of computers in automatic control systems, approaches and studies required for including a computer in such control systems, and an analysis of the structure of automatic control systems with computers. Attention is also given to functional blocks in the considered systems.
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Directory of Open Access Journals (Sweden)
Vera L. Ferracini
2005-06-01
Full Text Available This work presents an alternative method for determination of the herbicides tebuthiuron and hexazinone in ground water. The extraction was made with dichloromethane and the analyses by high performance liquid chromatography (HPLC, using reversed-phase column, C-18, mobile phase methanol/water 50:50, v/v, detection and quantification at 247 nm. The following validation parameters were obtained: limit of detection of method 0.02 and 0.03 µg L-1, limit of quantification of method 0.07 and 0.09 µg L-1; linear range limit of quantification of instrument - 300 µg L-1 (r² > 0.998; recoveries from 90.3 to 108.2% and 90.3 to 101.6%; intermediary precision (%RSD < 8 and < 6%, for hexazinone and tebuthiuron, respectively. The method showed to be efficient and reliable for determination of the herbicides in ground water.
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International Nuclear Information System (INIS)
Ohno, Takeshi; Takaku, Yuichi; Hisamatsu, Shun'ichi
2007-01-01
We have developed precise analytical methods for strontium and lanthanide isotopic ratios using multiple collector-ICP-mass spectrometry (MC-ICP-MS) for experimental and environmental studies of their behavior. In order to obtain precise isotopic data using MC-ICP-MS, the mass discrimination effect was corrected by an exponential law correction method. The resulting isotopic data demonstrated that highly precise isotopic analyses (better than 0.1 per mille as 2SD) could be achieved. We also adopted a de-solvating nebulizer system to improve the sensitivity. This system could minimize the water load into the plasma and provided about five times larger intensity of analyte than a conventional nebulizer system did. (author)
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Raub, Kristin B; Vlahos, Penny; Whitney, Michael
2015-08-01
Laboratory and field trials evaluated the efficacy of three methods of detecting aquatic pesticide concentrations. Currently used pesticides: atrazine, metolachlor, and diazinon and legacy pesticide dieldrin were targeted. Pesticides were extracted using solid-phase extraction (SPE) of water samples, titanium plate passive samplers coated in ethylene vinyl acetate (EVA) and eastern oysters (Crassostrea viginica) as biosamplers. A laboratory study assessed the extraction efficiencies and precision of each method. Passive samplers yielded the highest precision of the three methods (RSD: 3-14% EVA plates; 19-60% oysters; and 25-56% water samples). Equilibrium partition coefficients were derived. A significant relationship was found between the concentration in oyster tissue and the ambient aquatic concentration. In the field (Housatonic River, CT (U.S.)) water sampling (n = 5) detected atrazine at 1.61-7.31 μg L(-1), oyster sampling (n = 2×15) detected dieldrin at n.d.-0.096 μg L(-1) SW and the passive samplers (n = 5×3) detected atrazine at 0.97-3.78 μg L(-1) SW and dieldrin at n.d.-0.68 μg L(-1) SW. Copyright © 2015 Elsevier Ltd. All rights reserved.
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International Nuclear Information System (INIS)
Batusov, V.; Budagov, Yu.; Gayde, J.C.
2002-01-01
The high-precision assembly of large experimental set-ups is of a principal necessity for the successful execution of the forthcoming LHC research programme in the TeV-beams. The creation of an adequate survey and control metrology method is an essential part of the detector construction scenario. This work contains the dimension measurement data for ATLAS hadron calorimeter MODULE No. 8 (6 m, 22 tons) which were obtained by laser and by photogrammetry methods. The comparative data analysis demonstrates the measurements agreement within ± 70 μm. It means, these two clearly independent methods can be combined and lead to the rise of a new-generation engineering culture: high-precision metrology when precision assembling of large scale massive objects
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Batusov, V; Gayde, J C; Khubua, J I; Lasseur, C; Lyablin, M V; Miralles-Verge, L; Nessi, Marzio; Rusakovitch, N A; Sissakian, A N; Topilin, N D
2002-01-01
The high-precision assembly of large experimental set-ups is of a principal necessity for the successful execution of the forthcoming LHC research programme in the TeV-beams. The creation of an adequate survey and control metrology method is an essential part of the detector construction scenario. This work contains the dimension measurement data for ATLAS hadron calorimeter MODULE No. 8 (6 m, 22 tons) which were obtained by laser and by photogrammetry methods. The comparative data analysis demonstrates the measurements agreement within +or-70 mu m. It means, these two clearly independent methods can be combined and lead to the rise of a new-generation engineering culture: high-precision metrology when precision assembling of large scale massive objects. (3 refs).
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Oakden-Rayner, Luke; Carneiro, Gustavo; Bessen, Taryn; Nascimento, Jacinto C; Bradley, Andrew P; Palmer, Lyle J
2017-05-10
Precision medicine approaches rely on obtaining precise knowledge of the true state of health of an individual patient, which results from a combination of their genetic risks and environmental exposures. This approach is currently limited by the lack of effective and efficient non-invasive medical tests to define the full range of phenotypic variation associated with individual health. Such knowledge is critical for improved early intervention, for better treatment decisions, and for ameliorating the steadily worsening epidemic of chronic disease. We present proof-of-concept experiments to demonstrate how routinely acquired cross-sectional CT imaging may be used to predict patient longevity as a proxy for overall individual health and disease status using computer image analysis techniques. Despite the limitations of a modest dataset and the use of off-the-shelf machine learning methods, our results are comparable to previous 'manual' clinical methods for longevity prediction. This work demonstrates that radiomics techniques can be used to extract biomarkers relevant to one of the most widely used outcomes in epidemiological and clinical research - mortality, and that deep learning with convolutional neural networks can be usefully applied to radiomics research. Computer image analysis applied to routinely collected medical images offers substantial potential to enhance precision medicine initiatives.
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Fietzke, J.; Liebetrau, V.; Guenther, D.; Frische, M.; Zumholz, K.; Hansteen, T. H.; Eisenhauer, A.
2008-12-01
An alternative approach for the evaluation of isotope ratio data using LA-MC-ICP-MS will be presented. In contrast to previously applied methods it is based on the simultaneous responses of all analyte isotopes of interest and the relevant interferences without performing a conventional background correction. Significant improvements in precision and accuracy can be achieved when applying this new method and will be discussed based on the results of two first methodical applications: a) radiogenic and stable Sr isotopes in carbonates b) stable chlorine isotopes of pyrohydrolytic extracts. In carbonates an external reproducibility of the 87Sr/86Sr ratios of about 19 ppm (RSD) was achieved, an improvement of about a factor of 5. For recent and sub-recent marine carbonates a mean radiogenic strontium isotope ratio 87Sr/86Sr of 0.709170±0.000007 (2SE) was determined, which agrees well with the value of 0.7091741±0.0000024 (2SE) reported for modern sea water [1,2]. Stable chlorine isotope ratios were determined ablating pyrohydrolytic extracts with a reproducibility of about 0.05‰ (RSD). For basaltic reference material JB1a and JB2 chlorine isotope ratios were determined relative to SMOC (standard mean ocean chlorinity) δ37ClJB-1a = (-0.99±0.06) ‰ and δ37ClJB-1a = (-0.60±0.03) ‰ (SD), respectively, in accordance with published data [3]. The described strategies for data reduction are considered to be generally applicable for all isotope ratio measurements using LA-MC-ICP-MS. [1] J.M. McArthur, D. Rio, F. Massari, D. Castradori, T.R. Bailey, M. Thirlwall, S. Houghton, Palaeogeo. Palaeoclim. Palaeoeco., 2006, 242 (126), doi: 10.1016/j.palaeo.2006.06.004 [2] J. Fietzke, V. Liebetrau, D. Guenther, K. Guers, K. Hametner, K. Zumholz, T.H. Hansteen and A. Eisenhauer, J. Anal. At. Spectrom., 2008, 23, 955-961, doi:10.1039/B717706B [3] J. Fietzke, M. Frische, T.H. Hansteen and A. Eisenhauer, J. Anal. At. Spectrom., 2008, 23, 769-772, doi:10.1039/B718597A
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Kawalilak, C E; Johnston, J D; Cooper, D M L; Olszynski, W P; Kontulainen, S A
2016-02-01
Precision errors of cortical bone micro-architecture from high-resolution peripheral quantitative computed tomography (pQCT) ranged from 1 to 16 % and did not differ between automatic or manually modified endocortical contour methods in postmenopausal women or young adults. In postmenopausal women, manually modified contours led to generally higher cortical bone properties when compared to the automated method. First, the objective of the study was to define in vivo precision errors (coefficient of variation root mean square (CV%RMS)) and least significant change (LSC) for cortical bone micro-architecture using two endocortical contouring methods: automatic (AUTO) and manually modified (MOD) in two groups (postmenopausal women and young adults) from high-resolution pQCT (HR-pQCT) scans. Second, it was to compare precision errors and bone outcomes obtained with both methods within and between groups. Using HR-pQCT, we scanned twice the distal radius and tibia of 34 postmenopausal women (mean age ± SD 74 ± 7 years) and 30 young adults (27 ± 9 years). Cortical micro-architecture was determined using AUTO and MOD contour methods. CV%RMS and LSC were calculated. Repeated measures and multivariate ANOVA were used to compare mean CV% and bone outcomes between the methods within and between the groups. Significance was accepted at P young adults, postmenopausal women had better precision for radial cortical porosity (precision difference 9.3 %) and pore volume (7.5 %) with MOD. Young adults had better precision for cortical thickness (0.8 %, MOD) and tibial cortical density (0.2 %, AUTO). In postmenopausal women, MOD resulted in 0.2-54 % higher values for most cortical outcomes, as well as 6-8 % lower radial and tibial cortical BMD and 2 % lower tibial cortical thickness. Results suggest that AUTO and MOD endocortical contour methods provide comparable repeatability. In postmenopausal women, manual modification of endocortical contours led to
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Directory of Open Access Journals (Sweden)
Pedro Henrique Reis da Silva
2017-06-01
Full Text Available ABSTRACT Prednisone is an anti-inflammatory steroid drug widely used in clinical practice. However, no high-performance liquid chromatographic (HPLC method has been described in the literature for the determination of prednisone in capsules until now. Thus, an HPLC method was developed using a C18 (250x4.0, 5 µm column, with methanol:water (70:30 as mobile phase at a flow rate of 1 mL/min and detection at 240 nm. The developed method was validated following current Brazilian legislation. Additionally, linearity was assessed by evaluating the assumptions of normality, homoscedasticity, and independency of residuals, and the fit to the linear model. The method showed linearity (r2>0.99 over the range of 14.0-26.0 µg/mL, selectivity, precision (RSD<2.0%, robustness, and accuracy (average recovery of 100.05%. The chromatographic procedure was applied for assay and uniformity content determination of three different batches of prednisone capsules, showing to be suitable for their quality control.
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International Nuclear Information System (INIS)
Stepanov, A.V.; Stepanov, D.A.; Nikitina, S.A.; Gogoleva, T.D.; Grigor'eva, M.G.; Bulyanitsa, L.S.; Panteleev, Yu.A.; Pevtsova, E.V.; Domkin, V.D.; Pen'kin, M.V.
2006-01-01
Precision method of spectrophotometry with inner standardization is used for analysis of pure Pu solutions. Improvement of the spectrophotometer and spectrophotometric method of analysis is done to decrease accidental constituent of relative error of the method. Influence of U, Np impurities and corrosion products on systematic constituent of error of the method, and effect of fluoride-ion on completeness of Pu oxidation in sample preparation are studied [ru
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Directory of Open Access Journals (Sweden)
Laís Engroff Scheeren
2015-06-01
Full Text Available Saxagliptin is a potent and selective inhibitor of the enzyme dipeptidyl peptidase 4. It is effective in the treatment of type 2 diabetes mellitus because it stimulates the pancreas to produce insulin. In the present study, a liquid chromatography method was developed and validated to quantify the drug in tablets. This method was based on the isocratic elution of saxagliptin, using a mobile phase consisting of 0.1% phosphoric acid at pH 3.0 - methanol (70: 30, v/v at a flow rate of 1 mL.min-1 with UV detection at 225 nm. The chromatographic separation was achieved in 8 minutes on a Waters XBridge C18 column (250 mm x 4.6 mm, 5µm maintained at ambient temperature. The proposed method proved to be specific and robust for the quality control of saxagliptin in pharmaceutical dosage forms, showing good linearity in the range of 15.0 - 100.0 µg.mL-1 (r>0.999, precision (RSD
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Directory of Open Access Journals (Sweden)
Ali S. Abdelhameed
2014-01-01
Full Text Available A simple, sensitive, and accurate HPLC-DAD method has been developed and validated for the simultaneous determination of pantoprazole and etodolac in rat plasma as a tool for therapeutic drug monitoring. Optimal chromatographic separation of the analytes was achieved on a Waters Symmetry C18 column using a mobile phase that consisted of phosphate buffer pH~4.0 as eluent A and acetonitrile as eluent B in a ratio of A : B, 55 : 45 v/v for 6 min, pumped isocratically at a flow rate of 0.8 mL min−1. The eluted analytes were monitored using photodiode array detector set to quantify samples at 254 nm. The method was linear with r2=0.9999 for PTZ and r2=0.9995 for ETD at a concentration range of 0.1–15 and 5–50 μgmL−1 for PTZ and ETD, respectively. The limits of detection were found to be 0.033 and 0.918 μgmL−1 for PTZ and ETD, respectively. The method was statistically validated for linearity, accuracy, precision, and selectivity following the International Conference for Harmonization (ICH guidelines. The reproducibility of the method was reliable with the intra- and interday precision (% RSD <7.76% for PTZ and <7.58 % for ETD.
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Li, Wei; Herrman, Timothy J; Dai, Susie Y
2010-01-01
A simple, fast, and robust method was developed for the determination of fumonisin B1 (FB1), fumonisin B2 (FB2), and fumonisin B3 (FB3) in corn-based human food and animal feed (cornmeal). The method involves a single extraction step followed by centrifugation and filtration before analysis by ultra-performance liquid chromatographylelectrospray ionization (UPLC/ESI)-MS/MS. The LC/MS/MS method developed here represents the fastest and simplest procedure (<30 min) among both conventional HPLC methods and other LC/MS methods using SPE cleanup. The potential for high throughput analysis makes the method particularly beneficial for regulatory agencies and analytical laboratories with a high sample volume. A single-laboratory validation was conducted by testing three different spiking levels (200, 500, and 1000 ng/g for FB1 and FB2; 100, 250, and 500 ng/g for FB3) for accuracy and precision. Recoveries of FB1 ranged from 93 to 98% with RSD values of 3-8%. Recoveries of FB2 ranged from 104 to 108%, with RSD values of 2-6%. Recoveries of FB3 ranged from 94 to 108%, with RSD values of 2-5%.
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Mixed-Precision Spectral Deferred Correction: Preprint
Energy Technology Data Exchange (ETDEWEB)
Grout, Ray W. S.
2015-09-02
Convergence of spectral deferred correction (SDC), where low-order time integration methods are used to construct higher-order methods through iterative refinement, can be accelerated in terms of computational effort by using mixed-precision methods. Using ideas from multi-level SDC (in turn based on FAS multigrid ideas), some of the SDC correction sweeps can use function values computed in reduced precision without adversely impacting the accuracy of the final solution. This is particularly beneficial for the performance of combustion solvers such as S3D [6] which require double precision accuracy but are performance limited by the cost of data motion.
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Precise method for correcting count-rate losses in scintillation cameras
International Nuclear Information System (INIS)
Madsen, M.T.; Nickles, R.J.
1986-01-01
Quantitative studies performed with scintillation detectors often require corrections for lost data because of the finite resolving time of the detector. Methods that monitor losses by means of a reference source or pulser have unacceptably large statistical fluctuations associated with their correction factors. Analytic methods that model the detector as a paralyzable system require an accurate estimate of the system resolving time. Because the apparent resolving time depends on many variables, including the window setting, source distribution, and the amount of scattering material, significant errors can be introduced by relying on a resolving time obtained from phantom measurements. These problems can be overcome by curve-fitting the data from a reference source to a paralyzable model in which the true total count rate in the selected window is estimated from the observed total rate. The resolving time becomes a free parameter in this method which is optimized to provide the best fit to the observed reference data. The fitted curve has the inherent accuracy of the reference source method with the precision associated with the observed total image count rate. Correction factors can be simply calculated from the ratio of the true reference source rate and the fitted curve. As a result, the statistical uncertainty of the data corrected by this method is not significantly increased
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In vivo precision of conventional and digital methods of obtaining complete-arch dental impressions
Ender, Andreas; Attin, Thomas; Mehl, Albert
2016-01-01
STATEMENT OF PROBLEM: Digital impression systems have undergone significant development in recent years, but few studies have investigated the accuracy of the technique in vivo, particularly compared with conventional impression techniques. PURPOSE: The purpose of this in vivo study was to investigate the precision of conventional and digital methods for complete-arch impressions. MATERIAL AND METHODS: Complete-arch impressions were obtained using 5 conventional (polyether, POE; vinylsilox...
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International Nuclear Information System (INIS)
Nascimento, Natalia C.E.S.; Oliveira, Mércia L.; Lima, Fernando R.A.; Silveira, Marina B.; Ferreira, Soraya Z.; Silva, Juliana B.
2017-01-01
[ 18 F]Fluoromisonidazole ([ 18 F]FMISO) is a nitroimidazole derivative labelled with fluorine-18 that selectively binds to hypoxic cells. It has been shown to be a suitable PET tracer for imaging hypoxia in tumors as well as in noncancerous tissues. [ 18 F]FMISO was prepared using a TRACERlabMX FDG ® module (GE) with cassettes, software sequence and reagents kits from ABX. In this work, we aimed to develop and to validate a new high performance liquid chromatography (HPLC) method for determination of chemical purity of [ 18 F]FMISO. Analyses were performed with an Agilent chromatograph equipped with radioactivity and UV detectors. [ 18 F]FMISO and impurities were separated on a C18 column by gradient elution with water and acetonitrile. Selectivity, linearity, detection limit (DL), quantification limit (LQ), precision, accuracy and robustness were assessed to demonstrate that the HPLC method is adequate for its intended purpose. The HPLC method showed a good precision, as all RSD values were lower than 5%. Robustness was evaluated considering a variation on parameters such mobile phase gradient and flow rate. Results evidenced that the HPLC method is validated and is suitable for radiochemical purity evaluation of [ 18 F]FMISO, considering operational conditions of our laboratory. As an extension of this work, other analytical methods used for [ 18 F]FMISO quality control should be evaluated, in compliance with good manufacture practice. (author)
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Mano, Junichi; Masubuchi, Tomoko; Hatano, Shuko; Futo, Satoshi; Koiwa, Tomohiro; Minegishi, Yasutaka; Noguchi, Akio; Kondo, Kazunari; Akiyama, Hiroshi; Teshima, Reiko; Kurashima, Takeyo; Takabatake, Reona; Kitta, Kazumi
2013-01-01
In this article, we report a novel real-time PCR-based analytical method for quantitation of the GM maize event LY038. We designed LY038-specific and maize endogenous reference DNA-specific PCR amplifications. After confirming the specificity and linearity of the LY038-specific PCR amplification, we determined the conversion factor required to calculate the weight-based content of GM organism (GMO) in a multilaboratory evaluation. Finally, in order to validate the developed method, an interlaboratory collaborative trial according to the internationally harmonized guidelines was performed with blind DNA samples containing LY038 at the mixing levels of 0, 0.5, 1.0, 5.0 and 10.0%. The precision of the method was evaluated as the RSD of reproducibility (RSDR), and the values obtained were all less than 25%. The limit of quantitation of the method was judged to be 0.5% based on the definition of ISO 24276 guideline. The results from the collaborative trial suggested that the developed quantitative method would be suitable for practical testing of LY038 maize.
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Ding, Chun-guang; Zhu, Chun; Liu, De-ye; Dong, Ming; Zhang, Ai-hua; Pan, Ya-juan; Yan, Hui-fang
2012-08-01
To establish an inductively coupled plasma mass spectrometry(ICP-MS) method for determination of 30 trace elements including As, Ba, Be, Bi, Ni, Cd, Co, Cr, Cs, Cu, Ga, Mn, Pb, Sr, Tl, V, Ge, Mo, Nb, Ti, W, Te, Se, Zr, In, Sb, Hg, Ce, La, and Sm in human blood. The blood samples were analyzed by ICP-MS after diluted 1/10 with 0.01% Triton-X-100 and 0.5% nitric acid solution. Y, Rh and Lu were selected as internal standard in order to correct the matrix interference of Cr, As, Se, and Hg by a hex pole-based collision-reaction cell. Other elements were determined with standard method. The limits of detection, precision and accuracy of the method were evaluated. The accuracy was validated by the determination of the whole blood reference material. All the 30 trace elements have good linearity in their determination range, with the correlation coefficient > 0.9999. The limits of detection of the 30 trace elements were in the range of 1.19 - 2.15 µg/L and the intra-precision and inter-precision (relative standard deviation, RSD) were less than 14.3% (except Hg RSD < 21.2%, and Ni RSD < 15.4%). The spiked recovery for all elements fell within 59.3% - 119.2%. Among the 13 whole blood reference materials, V, Cr, Mn, Co, Ni, Cu, As, Se, Cd, Te, and Pb (1.45, 1.19, 18.40, 0.18, 1.57, 591.00, 2.97, 61.00, 0.35, 1.86, and 9.70 µg/L respectively) fell within the acceptable range and the detection results of Hg (0.59 µg/L) and Mo (1.59 µg/L) were slightly beyond the range. This method was simple, fast and effective. It can be used to monitor the multi-elementary concentration in human blood.
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International Nuclear Information System (INIS)
Hassenstein, A.; Richard, G.; Inhoffen, W.; Scholz, F.
2007-01-01
The new integration method (DIM) provides for the first time the anatomically precise integration of the OCT-scan position into the angiogram (fluorescein angiography, FLA), using reference marker at corresponding vessel crossings. Therefore an exact correlation of angiographic and morphological pathological findings is possible und leads to a better understanding of OCT and FLA. Occult findings in FLA were the patient group which profited most. Occult leakages could gain additional information using DIM such as serous detachment of the retinal pigment epithelium (RPE) in a topography. So far it was unclear whether the same localization in the lesion was examined by FLA and OCT especially when different staff were performing and interpreting the examination. Using DIM this problem could be solved using objective markers. This technique is the requirement for follow-up examinations by OCT. Using DIM for an objective, reliable and precise correlation of OCT and FLA-findings it is now possible to provide the identical scan-position in follow-up. Therefore for follow-up in clinical studies it is mandatory to use DIM to improve the evidence-based statement of OCT and the quality of the study. (author) [de
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Development of Ultraviolet Spectrophotometric Method for Analysis ...
African Journals Online (AJOL)
HP
Method for Analysis of Lornoxicam in Solid Dosage. Forms. Sunit Kumar Sahoo ... testing. Mean recovery was 100.82 % for tablets. Low values of % RSD indicate .... Saharty E, Refaat YS, Khateeb ME. Stability-. Indicating. Spectrophotometric.
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Directory of Open Access Journals (Sweden)
Monika L. Jadhav
2014-01-01
Full Text Available Two UV-spectrophotometric methods have been developed and validated for simultaneous estimation of valsartan and hydrochlorothiazide in a tablet dosage form. The first method employed solving of simultaneous equations based on the measurement of absorbance at two wavelengths, 249.4 nm and 272.6 nm, λmax for valsartan and hydrochlorothiazide, respectively. The second method was absorbance ratio method, which involves formation of Q-absorbance equation at 258.4 nm (isoabsorptive point and also at 272.6 nm (λmax of hydrochlorothiazide. The methods were found to be linear between the range of 5–30 µg/mL for valsartan and 4–24 μg/mL for hydrochlorothiazide using 0.1 N NaOH as solvent. The mean percentage recovery was found to be 100.20% and 100.19% for the simultaneous equation method and 98.56% and 97.96% for the absorbance ratio method, for valsartan and hydrochlorothiazide, respectively, at three different levels of standard additions. The precision (intraday, interday of methods was found within limits (RSD<2%. It could be concluded from the results obtained in the present investigation that the two methods for simultaneous estimation of valsartan and hydrochlorothiazide in tablet dosage form are simple, rapid, accurate, precise and economical and can be used, successfully, in the quality control of pharmaceutical formulations and other routine laboratory analysis.
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International Nuclear Information System (INIS)
Vinodh, M.; Vinayak, M.; Rahul, K.; Pankaj, P.
2012-01-01
A simple and reliable high-performance liquid chromatography (HPLC) method was developed and validated for Lacidipine in pure form and pharmaceutical dosage form. The method was developed on X bridge C-18 column (150 mm x 4.6 mm, 5 μm) with a mobile phase gradient system of ammonium acetate and acetonitrile. The effluent was monitored by PDA detector at 240 nm. Calibration curve was linear over the concentration range of 50-250 μg/ml. For Intra-day and inter-day precision % RSD values were found to be 0.83 % and 0.41 % respectively. Recovery of Lacidipine was found to be in the range of 99.78-101.76 %. The limits of detection (LOD) and quantification (LOQ) were 1.0 and 7.3 μg/ml respectively. The developed RP-HPLC method was successfully applied for the quantitative determination of lacidipine in pharmaceutical dosage. (author)
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International Nuclear Information System (INIS)
Yue, Cong; Ren, Xingmin; Yang, Yongfeng; Deng, Wangqun
2016-01-01
This paper provides a precise and efficacious methodology for manifesting forced vibration response with respect to the time-variant linear rotational structure subjected to unbalanced excitation. A modified algorithm based on time step precise integration method and Magnus expansion is developed for instantaneous dynamic problems. The iterative solution is achieved by the ideology of transition and dimensional increment matrix. Numerical examples on a typical accelerating rotation system considering gyroscopic moment and mass unbalance force comparatively demonstrate the validity, effectiveness and accuracy with Newmark-β method. It is shown that the proposed algorithm has high accuracy without loss efficiency.
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Novel Methods to Enhance Precision and Reliability in Muscle Synergy Identification during Walking
Kim, Yushin; Bulea, Thomas C.; Damiano, Diane L.
2016-01-01
Muscle synergies are hypothesized to reflect modular control of muscle groups via descending commands sent through multiple neural pathways. Recently, the number of synergies has been reported as a functionally relevant indicator of motor control complexity in individuals with neurological movement disorders. Yet the number of synergies extracted during a given activity, e.g., gait, varies within and across studies, even for unimpaired individuals. With no standardized methods for precise determination, this variability remains unexplained making comparisons across studies and cohorts difficult. Here, we utilize k-means clustering and intra-class and between-level correlation coefficients to precisely discriminate reliable from unreliable synergies. Electromyography (EMG) was recorded bilaterally from eight leg muscles during treadmill walking at self-selected speed. Muscle synergies were extracted from 20 consecutive gait cycles using non-negative matrix factorization. We demonstrate that the number of synergies is highly dependent on the threshold when using the variance accounted for by reconstructed EMG. Beyond use of threshold, our method utilized a quantitative metric to reliably identify four or five synergies underpinning walking in unimpaired adults and revealed synergies having poor reproducibility that should not be considered as true synergies. We show that robust and unreliable synergies emerge similarly, emphasizing the need for careful analysis in those with pathology. PMID:27695403
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FROM PERSONALIZED TO PRECISION MEDICINE
Directory of Open Access Journals (Sweden)
K. V. Raskina
2017-01-01
Full Text Available The need to maintain a high quality of life against a backdrop of its inevitably increasing duration is one of the main problems of modern health care. The concept of "right drug to the right patient at the right time", which at first was bearing the name "personalized", is currently unanimously approved by international scientific community as "precision medicine". Precision medicine takes all the individual characteristics into account: genes diversity, environment, lifestyles, and even bacterial microflora and also involves the use of the latest technological developments, which serves to ensure that each patient gets assistance fitting his state best. In the United States, Canada and France national precision medicine programs have already been submitted and implemented. The aim of this review is to describe the dynamic integration of precision medicine methods into routine medical practice and life of modern society. The new paradigm prospects description are complemented by figures, proving the already achieved success in the application of precise methods for example, the targeted therapy of cancer. All in all, the presence of real-life examples, proving the regularity of transition to a new paradigm, and a wide range of technical and diagnostic capabilities available and constantly evolving make the all-round transition to precision medicine almost inevitable.
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System and method for high precision isotope ratio destructive analysis
Bushaw, Bruce A; Anheier, Norman C; Phillips, Jon R
2013-07-02
A system and process are disclosed that provide high accuracy and high precision destructive analysis measurements for isotope ratio determination of relative isotope abundance distributions in liquids, solids, and particulate samples. The invention utilizes a collinear probe beam to interrogate a laser ablated plume. This invention provides enhanced single-shot detection sensitivity approaching the femtogram range, and isotope ratios that can be determined at approximately 1% or better precision and accuracy (relative standard deviation).
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In vivo precision of conventional and digital methods for obtaining quadrant dental impressions
Ender, Andreas; Zimmermann, Moritz; Attin, Thomas; Mehl, Albert
2016-01-01
OBJECTIVES Quadrant impressions are commonly used as alternative to full-arch impressions. Digital impression systems provide the ability to take these impressions very quickly; however, few studies have investigated the accuracy of the technique in vivo. The aim of this study is to assess the precision of digital quadrant impressions in vivo in comparison to conventional impression techniques. MATERIALS AND METHODS Impressions were obtained via two conventional (metal full-arch tray, CI, ...
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Chen, Yibin; Chen, Jiaxi; Chen, Xuan; Wang, Min; Wang, Wei
2015-01-01
A new method of uniform sampling is evaluated in this paper. The items and indexes were adopted to evaluate the rationality of the uniform sampling. The evaluation items included convenience of operation, uniformity of sampling site distribution, and accuracy and precision of measured results. The evaluation indexes included operational complexity, occupation rate of sampling site in a row and column, relative accuracy of pill weight, and relative deviation of pill weight. They were obtained from three kinds of drugs with different shape and size by four kinds of sampling methods. Gray correlation analysis was adopted to make the comprehensive evaluation by comparing it with the standard method. The experimental results showed that the convenience of uniform sampling method was 1 (100%), odds ratio of occupation rate in a row and column was infinity, relative accuracy was 99.50-99.89%, reproducibility RSD was 0.45-0.89%, and weighted incidence degree exceeded the standard method. Hence, the uniform sampling method was easy to operate, and the selected samples were distributed uniformly. The experimental results demonstrated that the uniform sampling method has good accuracy and reproducibility, which can be put into use in drugs analysis.
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International Nuclear Information System (INIS)
Ren, M J; Cheung, C F; Kong, L B
2012-01-01
In the measurement of ultra-precision freeform surfaces, least-squares-based form characterization methods are widely used to evaluate the form error of the measured surfaces. Although many methodologies have been proposed in recent years to improve the efficiency of the characterization process, relatively little research has been conducted on the analysis of associated uncertainty in the characterization results which may result from those characterization methods being used. As a result, this paper presents a task specific uncertainty analysis method with application in the least-squares-based form characterization of ultra-precision freeform surfaces. That is, the associated uncertainty in the form characterization results is estimated when the measured data are extracted from a specific surface with specific sampling strategy. Three factors are considered in this study which include measurement error, surface form error and sample size. The task specific uncertainty analysis method has been evaluated through a series of experiments. The results show that the task specific uncertainty analysis method can effectively estimate the uncertainty of the form characterization results for a specific freeform surface measurement
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Microbiological assay for the determination of meropenem in pharmaceutical dosage form.
Mendez, Andreas S L; Weisheimer, Vanessa; Oppe, Tércio P; Steppe, Martin; Schapoval, Elfrides E S
2005-04-01
Meropenem is a highly active carbapenem antibiotic used in the treatment of a wide range of serious infections. The present work reports a microbiological assay, applying the cylinder-plate method, for the determination of meropenem in powder for injection. The validation method yielded good results and included linearity, precision, accuracy and specificity. The assay is based on the inhibitory effect of meropenem upon the strain of Micrococcus luteus ATCC 9341 used as the test microorganism. The results of assay were treated statistically by analysis of variance (ANOVA) and were found to be linear (r=0.9999) in the range of 1.5-6.0 microg ml(-1), precise (intra-assay: R.S.D.=0.29; inter-assay: R.S.D.=0.94) and accurate. A preliminary stability study of meropenem was performed to show that the microbiological assay is specific for the determination of meropenem in the presence of its degradation products. The degraded samples were also analysed by the HPLC method. The proposed method allows the quantitation of meropenem in pharmaceutical dosage form and can be used for the drug analysis in routine quality control.
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Simultaneous HPTLC determination of strychnine and brucine in strychnos nux-vomica seed
Directory of Open Access Journals (Sweden)
Abid Kamal
2012-01-01
Full Text Available Objective: A simple, sensitive, and specific thin layer chromatography (TLC densitometry method has been developed for the simultaneous quantification of strychnine and brucine in the seeds of Strychnos nux-vomica. Materials and Methods: The method involved simultaneous estimation of strychnine and brucine after resolving it by high performance TLC (HPTLC on silica gel plate with chloroform-methanol-formic acid (8.5:1.5:0.4 v/v/v as the mobile phase. Results: The method was validated as per the ICH guidelines for precision (interday, intraday, intersystem, robustness, accuracy, limit of detection, and limit of quantitation. The relationship between the concentration of standard solutions and the peak response was linear within the concentration range of 50-1000 ng/spot for strychnine and 100-1000 ng/spot for brucine. The method precision was found to be 0.58-2.47 (% relative standard deviation [RSD] and 0.36-2.22 (% RSD for strychnine and brucine, respectively. Accuracy of the method was checked by recovery studies conducted at three different concentration levels and the average percentage recovery was found to be 100.75% for strychnine and 100.52% for brucine, respectively. Conclusions: The HPTLC method for the simultaneous quantification of strychnine and brucine was found to be simple, precise, specific, sensitive, and accurate and can be used for routine analysis and quality control of raw material of S. nux-vomica and several unani and ayurvedic formulations containing this as an ingredient.
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Directory of Open Access Journals (Sweden)
Amir Mehdizadeh
2005-04-01
Full Text Available A simple, sensitive and specific HPLC method and also a simple and fast extraction procedure were developed for quantitative analysis of fentanyl transdermal patches. Chloroform, methanol and ethanol were used as extracting solvents with recovery percent of 92.1, 94.3 and 99.4% respectively. Fentanyl was extracted with ethanol and the eluted fentanyl through the C18 column was monitored by UV detection at 230 nm. The linearity was at the range of 0.5-10 µg/mL with correlation coefficient (r2 of 0.9992. Both intra and inter-day accuracy and precision were within acceptable limits. The detection limit (DL and quantitation limit (QL were 0.15 and 0.5 µg/mL, respectively. Other validation characteristics such as selectivity, robustness and ruggedness were evaluated. Following method validation, a system suitability test (SST including capacity factor (k´, plate number (N, tailing factor (T, and RSD was defined for routine test.
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Brčić Karačonji, Irena; Jurica, Karlo
2017-07-01
To confirm the botanical origin of strawberry tree (Arbutus unedo L.) honey, a liquid-liquid extraction followed by GC-MS method was developed for the quantitative determination of homogentisic acid (HGA), the main phenolic compound in this honey. Different parameters affecting extraction, such as the type and volume of extraction solvents, pH of the solution, and amount of salt, were optimized. The method showed good linearity (r2 = 0.9990) over the tested concentration range (50-500 mg/kg) and a low LOD (0.3 mg/kg). Precision expressed as RSD was <7%. The average accuracy was 95%. The optimized method was applied for determining the HGA content in strawberry tree honey samples from Croatia. The HGA content in analyzed samples (n = 7) ranged from 245.1 to 485.9 mg/kg. The proposed method provided reliable performance and can be easily implemented for the routine monitoring of HGA in strawberry tree honey in order to assure honey QC.
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Bernardy, Jeffry A; Hubert, Terrance D; Ogorek, Jacob M; Schmidt, Larry J
2013-01-01
An LC/MS method was developed and validated for the quantitative determination and confirmation of antimycin-A (ANT-A) in water from lakes or streams. Three different water sample volumes (25, 50, and 250 mL) were evaluated. ANT-A was stabilized in the field by immediately extracting it from water into anhydrous acetone using SPE. The stabilized concentrated samples were then transported to a laboratory and analyzed by LC/MS using negative electrospray ionization. The method was determined to have adequate accuracy (78 to 113% recovery), precision (0.77 to 7.5% RSD with samples > or = 500 ng/L and 4.8 to 17% RSD with samples < or = 100 ng/L), linearity, and robustness over an LOQ range from 8 to 51 600 ng/L.
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Pano-Farias, Norma S; Ceballos-Magaña, Silvia G; Muñiz-Valencia, Roberto; Jurado, Jose M; Alcázar, Ángela; Aguayo-Villarreal, Ismael A
2017-12-15
Due the negative effects of pesticides on environment and human health, more efficient and environmentally friendly methods are needed. In this sense, a simple, fast, free from memory effects and economical direct-immersion single drop micro-extraction (SDME) method and GC-MS for multi-class pesticides determination in mango samples was developed. Sample pre-treatment using ultrasound-assisted solvent extraction and factors affecting the SDME procedure (extractant solvent, drop volume, stirring rate, ionic strength, time, pH and temperature) were optimized using factorial experimental design. This method presented high sensitive (LOD: 0.14-169.20μgkg -1 ), acceptable precision (RSD: 0.7-19.1%), satisfactory recovery (69-119%) and high enrichment factors (20-722). Several obtained LOQs are below the MRLs established by the European Commission; therefore, the method could be applied for pesticides determination in routing analysis and custom laboratories. Moreover, this method has shown to be suitable for determination of some of the studied pesticides in lime, melon, papaya, banana, tomato, and lettuce. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Md. Saddam Nawaz
2013-01-01
Full Text Available The purpose of this study was to develop and validate a new reversed phase high performance liquid chromatographic (RP-HPLC method to quantify in vitro dissolution assay of rabeprazole sodium in pharmaceutical tablet dosage form. Method development was performed on C 18, 100×4.6 mm ID, and 10 μm particle size column, and injection volume was 20 μL using a diode array detector (DAD to monitor the detection at 280 nm. The mobile phase consisted of buffer: acetonitrile at a ratio of 60 : 40 (v/v, and the flow rate was maintained at 1.0 mL/min. The method was validated in terms of suitability, linearity, specificity, accuracy, precision, stability, and sensitivity. Linearity was observed over the range of concentration 0.05–12.0 μg/mL, and the correlation coefficient was found excellent >0.999. The method was specific with respect to rabeprazole sodium, and the peak purity was found 99.99%. The method was precise and had relative standard deviations (RSD less than 2%. Accuracy was found in the range of 99.9 to 101.9%. The method was robust in different variable conditions and reproducible. This proposed fast, reliable, cost-effective method can be used as quality control tool for the estimation of rabeprazole sodium in routine dissolution test analysis.
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Chandra, Preeti; Kannujia, Rekha; Saxena, Ankita; Srivastava, Mukesh; Bahadur, Lal; Pal, Mahesh; Singh, Bhim Pratap; Kumar Ojha, Sanjeev; Kumar, Brijesh
2016-09-10
An ultra-high performance liquid chromatography electrospray ionization tandem mass spectrometry method has been developed and validated for simultaneous quantification of six major bioactive compounds in five varieties of Withania somnifera in various plant parts (leaf, stem and root). The analysis was accomplished on Waters ACQUITY UPLC BEH C18 column with linear gradient elution of water/formic acid (0.1%) and acetonitrile at a flow rate of 0.3mLmin(-1). The proposed method was validated with acceptable linearity (r(2), 0.9989-0.9998), precision (RSD, 0.16-2.01%), stability (RSD, 1.04-1.62%) and recovery (RSD ≤2.45%), under optimum conditions. The method was also successfully applied for the simultaneous determination of six marker compounds in twenty-six marketed formulations. Hierarchical cluster analysis and principal component analysis were applied to discriminate these twenty-six batches based on characteristics of the bioactive compounds. The results indicated that this method is advance, rapid, sensitive and suitable to reveal the quality of Withania somnifera and also capable of performing quality evaluation of polyherbal formulations having similar markers/raw herbs. Copyright © 2016 Elsevier B.V. All rights reserved.
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Energy Technology Data Exchange (ETDEWEB)
Rosas-Castor, J.M. [Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Químicas, Cd. Universitaria, San Nicolás de los Garza, Nuevo León, C.P. 66451 Nuevo León (Mexico); Group of Analytical Chemistry, Automation and Environment, University of Balearic Islands, Cra. Valldemossa km 7.5, 07122 Palma de Mallorca (Spain); Portugal, L.; Ferrer, L. [Group of Analytical Chemistry, Automation and Environment, University of Balearic Islands, Cra. Valldemossa km 7.5, 07122 Palma de Mallorca (Spain); Guzmán-Mar, J.L.; Hernández-Ramírez, A. [Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Químicas, Cd. Universitaria, San Nicolás de los Garza, Nuevo León, C.P. 66451 Nuevo León (Mexico); Cerdà, V. [Group of Analytical Chemistry, Automation and Environment, University of Balearic Islands, Cra. Valldemossa km 7.5, 07122 Palma de Mallorca (Spain); Hinojosa-Reyes, L., E-mail: laura.hinojosary@uanl.edu.mx [Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Químicas, Cd. Universitaria, San Nicolás de los Garza, Nuevo León, C.P. 66451 Nuevo León (Mexico)
2015-05-18
Highlights: • A fully automated flow-based modified-BCR extraction method was developed to evaluate the extractable As of soil. • The MSFIA–HG-AFS system included an UV photo-oxidation step for organic species degradation. • The accuracy and precision of the proposed method were found satisfactory. • The time analysis can be reduced up to eight times by using the proposed flow-based BCR method. • The labile As (F1 + F2) was <50% of total As in soil samples from As-contaminated-mining zones. - Abstract: A fully automated modified three-step BCR flow-through sequential extraction method was developed for the fractionation of the arsenic (As) content from agricultural soil based on a multi-syringe flow injection analysis (MSFIA) system coupled to hydride generation-atomic fluorescence spectrometry (HG-AFS). Critical parameters that affect the performance of the automated system were optimized by exploiting a multivariate approach using a Doehlert design. The validation of the flow-based modified-BCR method was carried out by comparison with the conventional BCR method. Thus, the total As content was determined in the following three fractions: fraction 1 (F1), the acid-soluble or interchangeable fraction; fraction 2 (F2), the reducible fraction; and fraction 3 (F3), the oxidizable fraction. The limits of detection (LOD) were 4.0, 3.4, and 23.6 μg L{sup −1} for F1, F2, and F3, respectively. A wide working concentration range was obtained for the analysis of each fraction, i.e., 0.013–0.800, 0.011–0.900 and 0.079–1.400 mg L{sup −1} for F1, F2, and F3, respectively. The precision of the automated MSFIA–HG-AFS system, expressed as the relative standard deviation (RSD), was evaluated for a 200 μg L{sup −1} As standard solution, and RSD values between 5 and 8% were achieved for the three BCR fractions. The new modified three-step BCR flow-based sequential extraction method was satisfactorily applied for arsenic fractionation in real agricultural
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Non-precision approach in manual mode
Directory of Open Access Journals (Sweden)
М. В. Коршунов
2013-07-01
Full Text Available Considered is the method of non-precision approach of an aircraft in the manual mode with a constant angle of path. Advantage of this method consists in the fact that the construction of approach with a constant angle of path provides the stable path of flight. It is also considered a detailed analysis of the possibility of the approach by the above-mentioned method. Conclusions contain recommendations regarding the use of the described method of non-precision approach during training flights.
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DEFF Research Database (Denmark)
Steentoft, Catharina; Bennett, Eric P; Schjoldager, Katrine Ter-Borch Gram
2014-01-01
Precise and stable gene editing in mammalian cell lines has until recently been hampered by the lack of efficient targeting methods. While different gene silencing strategies have had tremendous impact on many biological fields, they have generally not been applied with wide success in the field...... of glycobiology, primarily due to their low efficiencies, with resultant failure to impose substantial phenotypic consequences upon the final glycosylation products. Here, we review novel nuclease-based precision genome editing techniques enabling efficient and stable gene editing, including gene disruption...... by introducing single or double-stranded breaks at a defined genomic sequence. We here compare and contrast the different techniques and summarize their current applications, highlighting cases from the field of glycobiology as well as pointing to future opportunities. The emerging potential of precision gene...
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International Nuclear Information System (INIS)
Yan, Q.
2013-01-01
A reversed-phase high performance liquid chromatographic method for the successful separation and determination of 6 synthetic food additives (aspartame, acesulfame potassium, benzoic acid, sodium saccharin, tartrazine and sunset yellow) was developed. A EclipseXDB-C18 column (250x4.6 mm I.D.; 5 micro m) was used and the mobile phase contained methanol and 0.02 mol/L ammonium acetate (pH 6.0) (30:70, v/v) was pumped at a flow rate of 0.7 mL/min at room temperature. Successful separation conditions were obtained for all the compounds using an optimized gradient elution within 10 min. The diode array detector was used to monitor the food additives at 230 nm. The method was thoroughly validated, detection limits for all substances varied between 0.03 and 1.35 micro g/mg, the intra-day precision (as RSD) ranged from 1.57% to 4.72 %, the inter-day precision (as RSD) was between 2.05 % and 4.18 %. Satisfactory recoveries, ranging from 90.00 % to 109.87 %, were obtained. The proposed system was applied to drink samples. (author)
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Methods for semi-automated indexing for high precision information retrieval
Berrios, Daniel C.; Cucina, Russell J.; Fagan, Lawrence M.
2002-01-01
OBJECTIVE: To evaluate a new system, ISAID (Internet-based Semi-automated Indexing of Documents), and to generate textbook indexes that are more detailed and more useful to readers. DESIGN: Pilot evaluation: simple, nonrandomized trial comparing ISAID with manual indexing methods. Methods evaluation: randomized, cross-over trial comparing three versions of ISAID and usability survey. PARTICIPANTS: Pilot evaluation: two physicians. Methods evaluation: twelve physicians, each of whom used three different versions of the system for a total of 36 indexing sessions. MEASUREMENTS: Total index term tuples generated per document per minute (TPM), with and without adjustment for concordance with other subjects; inter-indexer consistency; ratings of the usability of the ISAID indexing system. RESULTS: Compared with manual methods, ISAID decreased indexing times greatly. Using three versions of ISAID, inter-indexer consistency ranged from 15% to 65% with a mean of 41%, 31%, and 40% for each of three documents. Subjects using the full version of ISAID were faster (average TPM: 5.6) and had higher rates of concordant index generation. There were substantial learning effects, despite our use of a training/run-in phase. Subjects using the full version of ISAID were much faster by the third indexing session (average TPM: 9.1). There was a statistically significant increase in three-subject concordant indexing rate using the full version of ISAID during the second indexing session (p < 0.05). SUMMARY: Users of the ISAID indexing system create complex, precise, and accurate indexing for full-text documents much faster than users of manual methods. Furthermore, the natural language processing methods that ISAID uses to suggest indexes contributes substantially to increased indexing speed and accuracy.
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Khan, Mohammad F; Rita, Shamima A; Kayser, Md Shahidulla; Islam, Md Shariful; Asad, Sharmeen; Bin Rashid, Ridwan; Bari, Md Abdul; Rahman, Muhammed M; Al Aman, D A Anwar; Setu, Nurul I; Banoo, Rebecca; Rashid, Mohammad A
2017-01-01
A simple, rapid, economic, accurate, and precise method for the estimation of rifampicin in a mixture of isoniazid and pyrazinamide by UV spectrophotometeric technique (guided by the theoretical investigation of physicochemical properties) was developed and validated. Theoretical investigations revealed that isoniazid and pyrazinamide both were freely soluble in water and slightly soluble in ethyl acetate whereas rifampicin was practically insoluble in water but freely soluble in ethyl acetate. This indicates that ethyl acetate is an effective solvent for the extraction of rifampicin from a water mixture of isoniazid and pyrazinamide. Computational study indicated that pH range of 6.0-8.0 would favor the extraction of rifampicin. Rifampicin is separated from isoniazid and pyrazinamide at pH 7.4 ± 0.1 by extracting with ethyl acetate. The ethyl acetate was then analyzed at λ max of 344.0 nm. The developed method was validated for linearity, accuracy and precision according to ICH guidelines. The proposed method exhibited good linearity over the concentration range of 2.5-35.0 μg/mL. The intraday and inter-day precision in terms of % RSD ranged from 1.09 to 1.70% and 1.63 to 2.99%, respectively. The accuracy (in terms of recovery) of the method varied from of 96.7 ± 0.9 to 101.1 ± 0.4%. The LOD and LOQ were found to be 0.83 and 2.52 μg/mL, respectively. In addition, the developed method was successfully applied to determine rifampicin combination (isoniazid and pyrazinamide) brands available in Bangladesh.
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Bertolini, Tiziana; Vicentini, Lorenza; Boschetti, Silvia; Andreatta, Paolo; Gatti, Rita
2016-09-10
A simple and fast chromatographic method using ultraviolet diode-array detector (UV-DAD) was developed for the automatic high performance liquid chromatography (HPLC) determination of the title of oleuropein in a new dietary supplements in form of effervescent granules. The chromatographic separations were performed on a C18 core-shell column with detection at λ=232nm. The mobile phase consisted of deionized water with 0.1% TFA and acetonitrile under gradient conditions at a flow-rate of 0.8mL/min. Oleuropein and oleuroside present in the raw material were characterized by high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). The validation of the analytical procedure has been performed determining the following parameters: specificity, linearity, repeatability, reproducibility, accuracy, limit of quantification (LOQ), stability of the standard and sample solutions. Linear response was observed in fortified placebo solutions (determination coefficient: 0.9998). Intra-day precision (relative standard deviation, RSD) was ≤5.0% for peak area and for retention times (tR) without significant differences between intra- and inter-day data. The limits of quantitation (LOQ) was about 5μg/mL and 9pmol/inject. Oleuropein recovery studies gave good results (99.9%) with a R.S.D. of 0.5%. The speed of analysis and the stability of the solutions with a fluctuation Δ (%) ≤2.0 at room temperature means an undoubted advantage of the method allowing the simultaneous preparation of many samples and consecutive chromatographic analyses by using an autosampler. The developed method is suitable for the quality control of oleuropein in raw material and industrial products. The method can be applied in any analytical laboratory not requiring a sophisticated instrumentation. Copyright © 2016 Elsevier B.V. All rights reserved.
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Precision of a new bedside method for estimation of the circulating blood volume
DEFF Research Database (Denmark)
Christensen, P; Eriksen, B; Henneberg, S W
1993-01-01
The present study is a theoretical and experimental evaluation of a modification of the carbon monoxide method for estimation of the circulating blood volume (CBV) with respect to the precision of the method. The CBV was determined from measurements of the CO-saturation of hemoglobin before...... ventilation with the CO gas mixture. The amount of CO administered during each determination of CBV resulted in an increase in the CO saturation of hemoglobin of 2.1%-3.9%. A theoretical noise propagation analysis was performed by means of the Monte Carlo method. The analysis showed that a CO dose...... patients. The coefficients of variation were 6.2% and 4.7% in healthy and diseased subjects, respectively. Furthermore, the day-to-day variation of the method with respect to the total amount of circulating hemoglobin (nHb) and CBV was determined from duplicate estimates separated by 24-48 h. In conclusion...
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Determination of (187)Os in molybdenite by ICP-MS with neutron-induced (186)Os and (188)Os spikes.
Qu, W; Du, A; Zhao, D
2001-10-31
The article describes a method for the determination of (187)Os in molybdenite by isotope dilution inductively coupled plasma-mass spectrometry (ID-ICP-MS) with neutron-induced (186)Os and (188)Os spike. The spike used in the present work was prepared in line with the principle by which artificial nuclides are produced in a nuclear reaction. The concentration and isotopic composition of osmium in the prepared spike were evaluated accurately with the isotope dilution method, using negative thermal ion mass spectrometry (N-TIMS). The advantage of this method is that using (186)Os and (188)Os double spikes can effectively compensate for the mass discrimination effects of ICP-MS. Thus, the common correction practice for mass bias in the isotope dilution method with a single spike is unnecessary. In addition, the method enables one to reduce the determined error arising from instrumental instability. The precision for the (187)Os/((186)Os+(188)Os) ratio was approximately 2% (2sigma, RSD), but in the case of (187)Os/(186)Os, (187)Os/(188)Os and (186)Os/(188)Os, precision ranged from 2.0 to 8% (2sigma, RSD). The results for (187)Os concentration in a molybdenite sample determined with this method showed good agreement with reference values.
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Directory of Open Access Journals (Sweden)
Osmar D. Prestes
2007-02-01
Full Text Available A rapid and efficient method for the analysis of histamine in wines using HPLC with fluorescence detection after derivatization was developed and validated. The method LOD and LOQ values were 0.25 and 0.50 mg L-1 respectively. The repeatability and intermediary precision for the instrument and for the method presented RSD values of 3.7 and 2.9%, and 6.0 and 5.6%, respectively. The recoveries were 95.5 and 89.9% for the fortification levels of 2 and 10 mg L-1. The method was applied to determine the histamine content in Cabernet Sauvignon wines, which presented values between 1.2 and 5.7 mg L-1.
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Jeong, In-Seek; Kwak, Byung-Man; Ahn, Jang-Hyuk; Leem, Donggil; Yoon, Taehyung; Yoon, Changyong; Jeong, Jayoung; Park, Jung-Min; Kim, Jin-Man
2012-10-01
In this study, nonheated saponification was employed as a novel, rapid, and easy sample preparation method for the determination of cholesterol in emulsified foods. Cholesterol content was analyzed using gas chromatography with a flame ionization detector (GC-FID). The cholesterol extraction method was optimized for maximum recovery from baby food and infant formula. Under these conditions, the optimum extraction solvent was 10 mL ethyl ether per 1 to 2 g sample, and the saponification solution was 0.2 mL KOH in methanol. The cholesterol content in the products was determined to be within the certified range of certified reference materials (CRMs), NIST SRM 1544 and SRM 1849. The results of the recovery test performed using spiked materials were in the range of 98.24% to 99.45% with an relative standard devitation (RSD) between 0.83% and 1.61%. This method could be used to reduce sample pretreatment time and is expected to provide an accurate determination of cholesterol in emulsified food matrices such as infant formula and baby food. A novel, rapid, and easy sample preparation method using nonheated saponification was developed for cholesterol detection in emulsified foods. Recovery tests of CRMs were satisfactory, and the recoveries of spiked materials were accurate and precise. This method was effective and decreased the time required for analysis by 5-fold compared to the official method. © 2012 Institute of Food Technologists®
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Directory of Open Access Journals (Sweden)
Md. Sarowar Jahan
2014-01-01
Full Text Available A rapid and stability-indicating reversed phase high-performance liquid chromatography (RP-HPLC method was developed for simultaneous quantification of paracetamol and ibuprofen in their combined dosage form especially to get some more advantages over other methods already developed for this combination. The method was validated according to United States Pharmacopeia (USP guideline with respect to accuracy, precision, specificity, linearity, solution stability, robustness, sensitivity, and system suitability. Forced degradation study was validated according to International Conference on Harmonisation (ICH. For this, an isocratic condition of mobile phase comprising phosphate buffer (pH 6.8 and acetonitrile in a ratio of 65:35, v/v at a flow rate of 0.7 mL/minute over RP C18 (octadecylsilane (ODS, 150 × 4.6 mm, 5 μm, Phenomenex Inc. column at ambient temperature was maintained. The method showed excellent linear response with correlation coefficient ( R 2 values of 0.999 and 1.0 for paracetamol and ibuprofen respectively, which were within the limit of correlation coefficient ( R 2 > 0.995. The percent recoveries for two drugs were found within the acceptance limit of (97.0-103.0%. Intra-and inter-day precision studies of the new method were less than the maximum allowable limit percentage of relative standard deviation (%RSD ≤ 2.0. Forced degradation of the drug product was carried out as per the ICH guidelines with a view to establishing the stability-indicating property of this method and providing useful information about the degradation pathways, degradation products, and how the quality of a drug substance and drug product changes with time under the influence of various stressing conditions. The degradation of ibuprofen was within the limit (5-20%, according to the guideline of ICH, while paracetamol showed <20% degradation in oxidation and basic condition.
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Jahan, Md Sarowar; Islam, Md Jahirul; Begum, Rehana; Kayesh, Ruhul; Rahman, Asma
2014-01-01
A rapid and stability-indicating reversed phase high-performance liquid chromatography (RP-HPLC) method was developed for simultaneous quantification of paracetamol and ibuprofen in their combined dosage form especially to get some more advantages over other methods already developed for this combination. The method was validated according to United States Pharmacopeia (USP) guideline with respect to accuracy, precision, specificity, linearity, solution stability, robustness, sensitivity, and system suitability. Forced degradation study was validated according to International Conference on Harmonisation (ICH). For this, an isocratic condition of mobile phase comprising phosphate buffer (pH 6.8) and acetonitrile in a ratio of 65:35, v/v at a flow rate of 0.7 mL/minute over RP C18 (octadecylsilane (ODS), 150 × 4.6 mm, 5 μm, Phenomenex Inc.) column at ambient temperature was maintained. The method showed excellent linear response with correlation coefficient (R (2)) values of 0.999 and 1.0 for paracetamol and ibuprofen respectively, which were within the limit of correlation coefficient (R (2) > 0.995). The percent recoveries for two drugs were found within the acceptance limit of (97.0-103.0%). Intra-and inter-day precision studies of the new method were less than the maximum allowable limit percentage of relative standard deviation (%RSD) ≤ 2.0. Forced degradation of the drug product was carried out as per the ICH guidelines with a view to establishing the stability-indicating property of this method and providing useful information about the degradation pathways, degradation products, and how the quality of a drug substance and drug product changes with time under the influence of various stressing conditions. The degradation of ibuprofen was within the limit (5-20%, according to the guideline of ICH), while paracetamol showed degradation in oxidation and basic condition.
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DEFF Research Database (Denmark)
Wielandt, Daniel Kim Peel; Bizzarro, Martin
2011-01-01
A novel thermal ionization mass spectrometry (TIMS) method for the three-isotope analysis of K has been developed, and ion chromatographic methods for the separation of K have been adapted for the processing of small samples. The precise measurement of K-isotopes is challenged by the presence of ...
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Zegbeh, H; Pirot, F; Quessada, T; Durand, T; Vételé, F; Rose, A; Bréant, V; Aulagner, G
2011-01-01
The parenteral nutrition admixture (PNA) manufacturing in hospital pharmacy is realized by aseptic transfer (AT) or sterilizing filtration (SF). The development of filling systems for PNA manufacturing requires, without standard, an evaluation comparing to traditional methods of SF. The filling accuracy of automated AT and SF was evaluated by mass and physical-chemistry tests in repeatability conditions (identical composition of PNA; n=five bags) and reproducibility conditions (different composition of PNA; n=57 bags). For each manufacturing method, the filling precision and the average time for PNA bags manufacturing were evaluated starting from an identical composition and volume PNA (n=five trials). Both manufacturing methods did not show significant difference of accuracy. Precision of both methods was lower than limits generally admitted for acceptability of mass and physical-chemistry tests. However, the manufacturing time for SF was superior (five different binary admixtures in five bags) or inferior (one identical binary admixture in five bags) to time recorded for automated AT. We show that serial manufacturing of PNA bags by SF with identical composition is faster than automated AT. Nevertheless, automated AT is faster than SF in variable composition of PNA. The manufacturing method choice will be motivate by the nature (i. e., variable composition or not) of the manufactured bags. Copyright © 2010 Elsevier Masson SAS. All rights reserved.
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International Nuclear Information System (INIS)
Arzumanov, S.S; Bondarenko, L.N.; Gel'tenbort, P.; Morozov, V.I.; Nesvizhevskij, V.V.; Panin, Yu.N.; Strepetov, A.N.
2007-01-01
The experimental setup and the method of measuring the neutron lifetime with a precision less then 1 s is described. The measurements will be carried out by storage of ultracold neutrons (UCN) into vessels with inner walls coated with fluorine polymer oil with simultaneous registration of inelastically scattered UCN leaving storage vessels. The analysis of statistical and methodical errors is carried out. The calculated estimation of the measurement accuracy is presented [ru
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Youssof, Abdullah M E; Salem-Bekhit, Mounir M; Shakeel, Faiyaz; Alanazi, Fars K; Haq, Nazrul
2016-07-01
The objective of the present investigation was to develop and validate a 'green' reversed phase high-performance liquid chromatography (RP-HPLC) method for rapid analysis of a cytotoxic drug 5-fluorouracil (5-FU) in bulk drug, marketed injection, water-in-oil (w/o) nanoemulsion, double water-in-oil-in-water (w/o/w) nanoemulsion and bacterial ghost (BG) matrix. The chromatography study was carried out at room temperature (25±1°C) using an HPLC system with the help of ultraviolet (UV)-visible detector. The chromatographic performance was achieved with a Nucleodur 150mm×4.6mm RP C8 column filled with 5µm filler as a static phase. The mobile phase consisted of ethyl acetate: methanol (7:3% v/v) which was delivered at a flow rate of 1.0mLmin(-1) and the drug was detected in UV mode at 254nm. The developed method was validated in terms of linearity (r(2)=0.998), accuracy (98.19-102.09%), precision (% RSD=0.58-1.17), robustness (% RSD=0.12-0.53) and sensitivity with satisfactory results. The efficiency of the method was demonstrated by the assay of the drug in marketed injection, w/o nanoemulsion, w/o/w nanoemulsion and BG with satisfactory results. The successful resolution of the drug along with its degradation products clearly established the stability-indicating nature of the proposed method. Overall, these results suggested that the proposed analytical method could be effectively applied to the routine analysis of 5-FU in bulk drug, various pharmaceutical dosage forms and BG. Copyright © 2016 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Dyah Styarini
2014-03-01
Full Text Available The development of analytical method for the determination of α-endosulfan and bifenthrin residues in tea has been done. The complex matrices and also the pigment were the challenge in doing quantification of the pesticide residues in tea matrices. In order to get appropriate analysis method for the determination of pesticide residues in tea, the modification was done in the analytical method for the determination of organochlorine multiresidue in non fat matrices: seasoning and spicy that is published by Directorate General of Food Crops, Directorate of Food Plant Protection. The modification was done particularly in clean-up step to remove the interferences from the extract of tea matrices such as the pigment that usually interfere the measurement with Gas Chromatography (GC. The result showed that the MDL value for both analytes were 0.5 ng/g that were much lower than MRLs. The percent recovery obtained from the method was 78.58 and 90.19% for α-endosulfan and bifenthrin, respectively. The precision of the analysis method for both analytes were good since the % RSD values were below than the Horwitz’s value that was 19.18% at spiking level concentration of 300 ng/g.
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Directory of Open Access Journals (Sweden)
Akhilesh Mishra
2014-01-01
Full Text Available This article describes a simple and rapid method for determination of curcumin (diferuloylmethane in aqueous humor of rabbit using high-performance liquid chromatography (HPLC. Analysis was performed using a C-18 column (250 × 4.6 mm, 5 μ luna by isocratic elution with a mobile phase containing 25 mM potassium dihydrogen orthophosphate (pH 3.5: Acetonitrile (40:60 and detection at 424 nm using a photodiode array (PDA detector for curcumin. The regression data for curcumin showed a good linear relationship with r 2 > 0.998 over the concentration range of 0.1-10 μg ml−1 . Relative standard deviations (RSD for the intraday and interday coefficient of variations for the assay were less than 5.0 and 8.5, respectively. The recovery of the method was between 79.8-83.6%. The quantification limit of the method for curcumin was 0.01 μg ml−1 . This method has good accuracy, precision, and quantitation limit. It is also concluded that the method is useful for measuring very low curcumin concentrations in aqueous humor.
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P.B., Mohite; R.B., Pandhare; S.G., Khanage
2012-01-01
Purpose: Lamivudine is cytosine and zidovudine is cytidine and is used as an antiretroviral agents. Both drugs are available in tablet dosage forms with a dose of 150 mg for LAM and 300 mg ZID respectively. Method: The method employed is based on first order derivative spectroscopy. Wavelengths 279 nm and 300 nm were selected for the estimation of the Lamovudine and Zidovudine respectively by taking the first order derivative spectra. The conc. of both drugs was determined by proposed method. The results of analysis have been validated statistically and by recovery studies as per ICH guidelines. Result: Both the drugs obey Beer’s law in the concentration range 10-50 μg mL-1,for LAM and ZID; with regression 0.9998 and 0.9999, intercept – 0.0677 and – 0.0043 and slope 0.0457 and 0.0391 for LAM and ZID, respectively.The accuracy and reproducibility results are close to 100% with 2% RSD. Conclusion: A simple, accurate, precise, sensitive and economical procedures for simultaneous estimation of Lamovudine and Zidovudine in tablet dosage form have been developed. PMID:24312779
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Dornfeld, David
2008-01-01
Today there is a high demand for high-precision products. The manufacturing processes are now highly sophisticated and derive from a specialized genre called precision engineering. Precision Manufacturing provides an introduction to precision engineering and manufacturing with an emphasis on the design and performance of precision machines and machine tools, metrology, tooling elements, machine structures, sources of error, precision machining processes and precision process planning. As well as discussing the critical role precision machine design for manufacturing has had in technological developments over the last few hundred years. In addition, the influence of sustainable manufacturing requirements in precision processes is introduced. Drawing upon years of practical experience and using numerous examples and illustrative applications, David Dornfeld and Dae-Eun Lee cover precision manufacturing as it applies to: The importance of measurement and metrology in the context of Precision Manufacturing. Th...
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Directory of Open Access Journals (Sweden)
A. Patnaik
2012-01-01
Full Text Available A simple, precise, accurate, economical and reproducible HPLC method for estimation of montelukast in tablet dosage form has been developed. Quantitative HPLC was performed with Shimadzu LC2010c HT with Winchrom Software with UV-Visible detector (SPD-IOA, PUMP (LC-IOAT and (LC-IOATvp. Phenomenex C8, 5 μm, 25 cm × 4.6 mm i.d. column was used in the study. The mobile phase of ACN: Acetate buffer= 6.5:3.5 of pH 3 were used in this study. The conditions optimized were: flow rate (1 mL/minute, wavelength (222 nm and run time was 20 min. Retention time was found to be 3.08 min. The linearity was found to be in the concentration range of 10-100 μg/mL. The developed method was evaluated in the assay of commercially available tablet moni containing 10 mg of montelukast. The amount of drug in tablet was found to be 10.34 mg/tab for the brand. Results of analysis were validated statistically and by recovery studies. The recovery studies 99.67% was indicative of the accuracy of proposed method. The precision was calculated as repeatability, inter and intraday variation (%RSD for the drug. By using the method, stability of the drug has been studied.
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Du, Q.; Xie, D.; Sun, Y.
2015-06-01
The integration of digital aerial photogrammetry and Light Detetion And Ranging (LiDAR) is an inevitable trend in Surveying and Mapping field. We calculate the external orientation elements of images which identical with LiDAR coordinate to realize automatic high precision registration between aerial images and LiDAR data. There are two ways to calculate orientation elements. One is single image spatial resection using image matching 3D points that registered to LiDAR. The other one is Position and Orientation System (POS) data supported aerotriangulation. The high precision registration points are selected as Ground Control Points (GCPs) instead of measuring GCPs manually during aerotriangulation. The registration experiments indicate that the method which registering aerial images and LiDAR points has a great advantage in higher automation and precision compare with manual registration.
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International Nuclear Information System (INIS)
2007-01-01
The present report introduces main results of investigations on precise tsunami evaluation methods, which were carried out from the viewpoint of safety evaluation for nuclear power facilities and deliberated by the Tsunami Evaluation Subcommittee. A framework for the probabilistic tsunami hazard analysis (PTHA) based on logic tree is proposed and calculation on the Pacific side of northeastern Japan is performed as a case study. Tsunami motions with dispersion and wave breaking were investigated both experimentally and numerically. The numerical simulation method is verified for its practicability by applying to a historical tsunami. Tsunami force is also investigated and formulae of tsunami pressure acting on breakwaters and on building due to inundating tsunami are proposed. (author)
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Ramiole, Cindy; D'Hayer, Benoit; Boudy, Vincent; Legagneux, Josette; Fonsart, Julien; Houzé, Pascal
2017-11-30
A rapid, sensitive and specific liquid chromatography coupled to tandem mass spectrometry method was developed for the simultaneous quantification pig plasma of ketamine and its two principal metabolites, norketamine and dehydronorketamine. Three extraction procoles were assessed including acetonitrile precipitation, Oase™ microplate extraction, and liquid-liquid extraction. Oase™ microplate extraction induced no significant matrix effect, important signal/noise ratio and good recoveries, ranging from 82 to 87% for the considered compounds. Using this extraction procedure, the assay was linear in the dynamic range 10-3000ng/mL (R 2 >0.99) regardless of the analytes. Intra- and inter-day accuracies were less than 12% for all compounds and intra- and inter-day precisions expressed as RSD were within ketamine, norketamine and dehydronorketamine concentrations up to 15,000ng/mL can be determined with good precision using appropriate sample dilution. The assay was successfully applied to pig plasma samples to determine the pharmacokinetics of ketamine and the consecutive metabolites after buccal administration of a 4mg/kg ketamine base solutions. Copyright © 2017 Elsevier B.V. All rights reserved.
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Liyanaarachchi, G V V; Mahanama, K R R; Somasiri, H P P S; Punyasiri, P A N
2018-02-01
The study presents the validation results of the method carried out for analysis of free amino acids (FAAs) in rice using l-theanine as the internal standard (IS) with o-phthalaldehyde (OPA) reagent using high-performance liquid chromatography-fluorescence detection. The detection and quantification limits of the method were in the range 2-16μmol/kg and 3-19μmol/kg respectively. The method had a wide working range from 25 to 600μmol/kg for each individual amino acid, and good linearity with regression coefficients greater than 0.999. Precision measured in terms of repeatability and reproducibility, expressed as percentage relative standard deviation (% RSD) was below 9% for all the amino acids analyzed. The recoveries obtained after fortification at three concentration levels were in the range 75-105%. In comparison to l-norvaline, findings revealed that l-theanine is suitable as an IS and the validated method can be used for FAA determination in rice. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Accuracy of complete-arch dental impressions: a new method of measuring trueness and precision
Ender, Andreas; Mehl, Albert
2013-01-01
STATEMENT OF PROBLEM: A new approach to both 3-dimensional (3D) trueness and precision is necessary to assess the accuracy of intraoral digital impressions and compare them to conventionally acquired impressions. PURPOSE: The purpose of this in vitro study was to evaluate whether a new reference scanner is capable of measuring conventional and digital intraoral complete-arch impressions for 3D accuracy. MATERIAL AND METHODS: A steel reference dentate model was fabricated and measured with a...
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Energy Technology Data Exchange (ETDEWEB)
Nascimento, Natalia C.E.S.; Oliveira, Mércia L.; Lima, Fernando R.A., E-mail: nataliafleming@hotmail.com, E-mail: mercial@cnen.gov.br, E-mail: falima@cnen.gov.br [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Silveira, Marina B.; Ferreira, Soraya Z.; Silva, Juliana B., E-mail: mbs@cdtn.br, E-mail: zandims@cdtn.br, E-mail: silvajb@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)
2017-07-01
[{sup 18}F]Fluoromisonidazole ([{sup 18}F]FMISO) is a nitroimidazole derivative labelled with fluorine-18 that selectively binds to hypoxic cells. It has been shown to be a suitable PET tracer for imaging hypoxia in tumors as well as in noncancerous tissues. [{sup 18}F]FMISO was prepared using a TRACERlabMX{sub FDG}® module (GE) with cassettes, software sequence and reagents kits from ABX. In this work, we aimed to develop and to validate a new high performance liquid chromatography (HPLC) method for determination of chemical purity of [{sup 18}F]FMISO. Analyses were performed with an Agilent chromatograph equipped with radioactivity and UV detectors. [{sup 18}F]FMISO and impurities were separated on a C18 column by gradient elution with water and acetonitrile. Selectivity, linearity, detection limit (DL), quantification limit (LQ), precision, accuracy and robustness were assessed to demonstrate that the HPLC method is adequate for its intended purpose. The HPLC method showed a good precision, as all RSD values were lower than 5%. Robustness was evaluated considering a variation on parameters such mobile phase gradient and flow rate. Results evidenced that the HPLC method is validated and is suitable for radiochemical purity evaluation of [{sup 18}F]FMISO, considering operational conditions of our laboratory. As an extension of this work, other analytical methods used for [{sup 18}F]FMISO quality control should be evaluated, in compliance with good manufacture practice. (author)
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Rus, David L.; Patton, Charles J.; Mueller, David K.; Crawford, Charles G.
2013-01-01
The characterization of total-nitrogen (TN) concentrations is an important component of many surface-water-quality programs. However, three widely used methods for the determination of total nitrogen—(1) derived from the alkaline-persulfate digestion of whole-water samples (TN-A); (2) calculated as the sum of total Kjeldahl nitrogen and dissolved nitrate plus nitrite (TN-K); and (3) calculated as the sum of dissolved nitrogen and particulate nitrogen (TN-C)—all include inherent limitations. A digestion process is intended to convert multiple species of nitrogen that are present in the sample into one measureable species, but this process may introduce bias. TN-A results can be negatively biased in the presence of suspended sediment, and TN-K data can be positively biased in the presence of elevated nitrate because some nitrate is reduced to ammonia and is therefore counted twice in the computation of total nitrogen. Furthermore, TN-C may not be subject to bias but is comparatively imprecise. In this study, the effects of suspended-sediment and nitrate concentrations on the performance of these TN methods were assessed using synthetic samples developed in a laboratory as well as a series of stream samples. A 2007 laboratory experiment measured TN-A and TN-K in nutrient-fortified solutions that had been mixed with varying amounts of sediment-reference materials. This experiment identified a connection between suspended sediment and negative bias in TN-A and detected positive bias in TN-K in the presence of elevated nitrate. A 2009–10 synoptic-field study used samples from 77 stream-sampling sites to confirm that these biases were present in the field samples and evaluated the precision and bias of TN methods. The precision of TN-C and TN-K depended on the precision and relative amounts of the TN-component species used in their respective TN computations. Particulate nitrogen had an average variability (as determined by the relative standard deviation) of 13
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Combining within and between instrument information to estimate precision
International Nuclear Information System (INIS)
Jost, J.W.; Devary, J.L.; Ward, J.E.
1980-01-01
When two instruments, both having replicated measurements, are used to measure the same set of items, between instrument information may be used to augment the within instrument precision estimate. A method is presented which combines the within and between instrument information to obtain an unbiased and minimum variance estimate of instrument precision. The method does not assume the instruments have equal precision
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Sampling plans in attribute mode with multiple levels of precision
International Nuclear Information System (INIS)
Franklin, M.
1986-01-01
This paper describes a method for deriving sampling plans for nuclear material inventory verification. The method presented is different from the classical approach which envisages two levels of measurement precision corresponding to NDA and DA. In the classical approach the precisions of the two measurement methods are taken as fixed parameters. The new approach is based on multiple levels of measurement precision. The design of the sampling plan consists of choosing the number of measurement levels, the measurement precision to be used at each level and the sample size to be used at each level
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Directory of Open Access Journals (Sweden)
Lílian Irene Dias da Silva
2006-02-01
Full Text Available Several extraction procedures are described for the determination of exchangeable and fixed ammonium, nitrate + nitrite, total exchangeable nitrogen and total nitrogen in certified reference soils and petroleum reservoir rock samples by steam distillation and indophenol method. After improvement of the original distillation system, an increase in worker safety, a reduction in time consumption, a decrease of 73% in blank value and an analysis without ammonia loss, which could possibly occur, were achieved. The precision (RSD < 8%, n = 3 and the detection limit (9 mg kg-1 NH4+-N are better than those of published procedures.
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American Society for Testing and Materials. Philadelphia
1992-01-01
1.1 This guide covers terminology useful for the preparation and interpretation of precision and bias statements. 1.2 In formulating precision and bias statements, it is important to understand the statistical concepts involved and to identify the major sources of variation that affect results. Appendix X1 provides a brief summary of these concepts. 1.3 To illustrate the statistical concepts and to demonstrate some sources of variation, a hypothetical data set has been analyzed in Appendix X2. Reference to this example is made throughout this guide. 1.4 It is difficult and at times impossible to ship nuclear materials for interlaboratory testing. Thus, precision statements for test methods relating to nuclear materials will ordinarily reflect only within-laboratory variation.
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Cancho, B; Ventur, F; Galceran, M
2000-11-03
A headspace solid-phase microextraction (HS-SPME) procedure has been developed and applied for the determination of cyanogen halides in treated water samples at microg/L concentrations. Several SPME coatings were tested, the divinylbenzene-Carboxen-polydimethylsiloxane fiber being the most appropriate coating. GC-electron-capture detection was used for separation and quantitation. Experimental parameters such as sample volume, addition of a salt, extraction time and desorption conditions were studied. The optimized method has an acceptable linearity, good precision, with RSD values activated carbon filtered water samples. There was good agreement between the results from both methods. Finally, the optimized procedure was applied to determine both compounds at the Barcelona water treatment plant (N.E. Spain). Cyanogen chloride in treated water was <1.0 microg/L and cyanogen bromide ranged from 3.2 to 6.4 microg/L.
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Directory of Open Access Journals (Sweden)
Xin Chen
2015-09-01
Full Text Available High-speed and precision positioning are fundamental requirements for high-acceleration low-load mechanisms in integrated circuit (IC packaging equipment. In this paper, we derive the transient nonlinear dynamicresponse equations of high-acceleration mechanisms, which reveal that stiffness, frequency, damping, and driving frequency are the primary factors. Therefore, we propose a new structural optimization and velocity-planning method for the precision positioning of a high-acceleration mechanism based on optimal spatial and temporal distribution of inertial energy. For structural optimization, we first reviewed the commonly flexible multibody dynamic optimization using equivalent static loads method (ESLM, and then we selected the modified ESLM for optimal spatial distribution of inertial energy; hence, not only the stiffness but also the inertia and frequency of the real modal shapes are considered. For velocity planning, we developed a new velocity-planning method based on nonlinear dynamic-response optimization with varying motion conditions. Our method was verified on a high-acceleration die bonder. The amplitude of residual vibration could be decreased by more than 20% via structural optimization and the positioning time could be reduced by more than 40% via asymmetric variable velocity planning. This method provides an effective theoretical support for the precision positioning of high-acceleration low-load mechanisms.
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Methods used by Elsam for monitoring precision and accuracy of analytical results
Energy Technology Data Exchange (ETDEWEB)
Hinnerskov Jensen, J [Soenderjyllands Hoejspaendingsvaerk, Faelleskemikerne, Aabenraa (Denmark)
1996-12-01
Performing round robins at regular intervals is the primary method used by ELsam for monitoring precision and accuracy of analytical results. The firs round robin was started in 1974, and today 5 round robins are running. These are focused on: boiler water and steam, lubricating oils, coal, ion chromatography and dissolved gases in transformer oils. Besides the power plant laboratories in Elsam, the participants are power plant laboratories from the rest of Denmark, industrial and commercial laboratories in Denmark, and finally foreign laboratories. The calculated standard deviations or reproducibilities are compared with acceptable values. These values originate from ISO, ASTM and the like, or from own experiences. Besides providing the laboratories with a tool to check their momentary performance, the round robins are vary suitable for evaluating systematic developments on a long term basis. By splitting up the uncertainty according to methods, sample preparation/analysis, etc., knowledge can be extracted from the round robins for use in many other situations. (au)
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International Nuclear Information System (INIS)
He, Bin; Frey, Eric C
2006-01-01
Accurate quantification of organ radionuclide uptake is important for patient-specific dosimetry. The quantitative accuracy from conventional conjugate view methods is limited by overlap of projections from different organs and background activity, and attenuation and scatter. In this work, we propose and validate a quantitative planar (QPlanar) processing method based on maximum likelihood (ML) estimation of organ activities using 3D organ VOIs and a projector that models the image degrading effects. Both a physical phantom experiment and Monte Carlo simulation (MCS) studies were used to evaluate the new method. In these studies, the accuracies and precisions of organ activity estimates for the QPlanar method were compared with those from conventional planar (CPlanar) processing methods with various corrections for scatter, attenuation and organ overlap, and a quantitative SPECT (QSPECT) processing method. Experimental planar and SPECT projections and registered CT data from an RSD Torso phantom were obtained using a GE Millenium VH/Hawkeye system. The MCS data were obtained from the 3D NCAT phantom with organ activity distributions that modelled the uptake of 111 In ibritumomab tiuxetan. The simulations were performed using parameters appropriate for the same system used in the RSD torso phantom experiment. The organ activity estimates obtained from the CPlanar, QPlanar and QSPECT methods from both experiments were compared. From the results of the MCS experiment, even with ideal organ overlap correction and background subtraction, CPlanar methods provided limited quantitative accuracy. The QPlanar method with accurate modelling of the physical factors increased the quantitative accuracy at the cost of requiring estimates of the organ VOIs in 3D. The accuracy of QPlanar approached that of QSPECT, but required much less acquisition and computation time. Similar results were obtained from the physical phantom experiment. We conclude that the QPlanar method, based
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Poitevin, Eric; Nicolas, Marine; Graveleau, Laetitia; Richoz, Janique; Andrey, Daniel; Monard, Florence
2009-01-01
A single-laboratory validation (SLV) and a ring trial (RT) were undertaken to determine nine nutritional elements in food products by inductively coupled plasma-atomic emission spectroscopy in order to improve and update AOAC Official Method 984.27. The improvements involved optimized microwave digestion, selected analytical lines, internal standardization, and ion buffering. Simultaneous determination of nine elements (calcium, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, and zinc) was made in food products. Sample digestion was performed through wet digestion of food samples by microwave technology with either closed or open vessel systems. Validation was performed to characterize the method for selectivity, sensitivity, linearity, accuracy, precision, recovery, ruggedness, and uncertainty. The robustness and efficiency of this method was proved through a successful internal RT using experienced food industry laboratories. Performance characteristics are reported for 13 certified and in-house reference materials, populating the AOAC triangle food sectors, which fulfilled AOAC criteria and recommendations for accuracy (trueness, recovery, and z-scores) and precision (repeatability and reproducibility RSD and HorRat values) regarding SLV and RT. This multielemental method is cost-efficient, time-saving, accurate, and fit-for-purpose according to ISO 17025 Norm and AOAC acceptability criteria, and is proposed as an improved version of AOAC Official Method 984.27 for fortified food products, including infant formula.
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International Nuclear Information System (INIS)
Mastiholimath, V.S.; Gupte, P.P.; Mannur, V.S.
2012-01-01
A simple and reliable UV spectrophotometric and high-performance liquid chromatography (HPLC) methods were developed and validated for Moexipril hydrochloride in pure form and pharmaceutical dosage form. The RP-HPLC method was developed on agilant eclipse C 18 , (150 mm x 4.6 mm, 5 μm) with a mobile phase gradient system of 60 % (methanol:acetonitrile (70:30 % v/v)) : 40 % 20 mM ammonium acetate buffer pH 4.5 (v/v) and UV spectrophotometric method was developed in phosphate buffer pH 6.8. The effluent was monitored by SPD-M20A, prominence PDA detector at 210 nm. Calibration curve was linear over the concentration range of 10-35 μg/ml and 1-9 μg/ml for RP-HPLC and UV with a regression coefficient of 0.999. For RP-HPLC method Inter-day and intra-day precision % RSD values were found to be 1.00078 % and 1.49408 % respectively. For UV method 0.73386 % to 1.44111 % for inter day 0.453864 to 1.15542 intra-day precision. Recovery of Moexipril hydrochloride was found to be in the range of 99.8538 % to 101.5614 % and 100.5297586 % to 100.6431587 % for UV and RP-HPLC respectively. The limits of detection (LOD) and quantification (LOQ) for HPLC were 0.98969 and 2.99907 μg/ml, respectively. The developed RP-HPLC and UV spectrophotometric method was successfully applied for the quantitative determination of Moexipril hydrochloride in pharmaceutical dosage. (author)
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2010-07-01
... criteria for approval of test methods for determining the sulfur content of motor vehicle diesel fuel, NRLM....584 What are the precision and accuracy criteria for approval of test methods for determining the... available gravimetric sulfur standard in the range of 1-10 ppm sulfur shall not differ from the accepted...
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a High Precision dem Extraction Method Based on Insar Data
Wang, Xinshuang; Liu, Lingling; Shi, Xiaoliang; Huang, Xitao; Geng, Wei
2018-04-01
In the 13th Five-Year Plan for Geoinformatics Business, it is proposed that the new InSAR technology should be applied to surveying and mapping production, which will become the innovation driving force of geoinformatics industry. This paper will study closely around the new outline of surveying and mapping and then achieve the TerraSAR/TanDEM data of Bin County in Shaanxi Province in X band. The studying steps are as follows; Firstly, the baseline is estimated from the orbital data; Secondly, the interferometric pairs of SAR image are accurately registered; Thirdly, the interferogram is generated; Fourth, the interferometric correlation information is estimated and the flat-earth phase is removed. In order to solve the phase noise and the discontinuity phase existing in the interferometric image of phase, a GAMMA adaptive filtering method is adopted. Aiming at the "hole" problem of missing data in low coherent area, the interpolation method of low coherent area mask is used to assist the phase unwrapping. Then, the accuracy of the interferometric baseline is estimated from the ground control points. Finally, 1 : 50000 DEM is generated, and the existing DEM data is used to verify the accuracy through statistical analysis. The research results show that the improved InSAR data processing method in this paper can obtain the high-precision DEM of the study area, exactly the same with the topography of reference DEM. The R2 can reach to 0.9648, showing a strong positive correlation.
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Accuracy and precision in thermoluminescence dosimetry
International Nuclear Information System (INIS)
Marshall, T.O.
1984-01-01
The question of accuracy and precision in thermoluminescent dosimetry, particularly in relation to lithium fluoride phosphor, is discussed. The more important sources of error, including those due to the detectors, the reader, annealing and dosemeter design, are identified and methods of reducing their effects on accuracy and precision to a minimum are given. Finally, the accuracy and precision achievable for three quite different applications are discussed, namely, for personal dosimetry, environmental monitoring and for the measurement of photon dose distributions in phantoms. (U.K.)
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Environment-assisted precision measurement
DEFF Research Database (Denmark)
Goldstein, G.; Cappellaro, P.; Maze, J. R.
2011-01-01
We describe a method to enhance the sensitivity of precision measurements that takes advantage of the environment of a quantum sensor to amplify the response of the sensor to weak external perturbations. An individual qubit is used to sense the dynamics of surrounding ancillary qubits, which...... are in turn affected by the external field to be measured. The resulting sensitivity enhancement is determined by the number of ancillas that are coupled strongly to the sensor qubit; it does not depend on the exact values of the coupling strengths and is resilient to many forms of decoherence. The method...... achieves nearly Heisenberg-limited precision measurement, using a novel class of entangled states. We discuss specific applications to improve clock sensitivity using trapped ions and magnetic sensing based on electronic spins in diamond...
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The Spatial and Temporal Analysis of Steppe Fires in Lake Elton’s Area Based on RSD
Directory of Open Access Journals (Sweden)
Shinkarenko Stanislav Sergeevich
2015-04-01
Full Text Available The study analyzed the satellite imagery for the period of 1985-2014 in order to identify the causes of wildfires in Lake Elton’s surroundings. It was found that in the early 21st century fires have the greatest impact on the landscape, which is caused by the decrease in the number of livestock grazing and reduced steppe loads in the late 1990s. The map of the fire frequency in the researched area, and t he map of areas recovering from fires in different years were developed on the basis of remote sensing data (RSD. The investigation of Landsat space imagery found that 54 % of the territory since 2004 has been subject to a prairie fire at least once. The maximum frequency of occurrence is marked for the southern area of Buluhta-Lake where eight fires were registered for the last decad. Most fires are caused by human factors: deliberate or spontaneous arson, military trials. The factors limiting the fires are: degraded pastures, roads, landforms and the elements of the hydrological network. The resulting materials allow to effectively organize further ground survey of these areas for a complete description and assessment of revegetation and their relation to the duration of pyrogenic successions.
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Rocío-Bautista, Priscilla; Martínez-Benito, Carla; Pino, Verónica; Pasán, Jorge; Ayala, Juan H; Ruiz-Pérez, Catalina; Afonso, Ana M
2015-07-01
Three metal-organic frameworks (MOFs), specifically HKUST-1, MOF-5, and MIL-53(Al), have been synthetized, characterized, studied and compared in a vortex-assisted dispersive micro-solid-phase extraction (VA-D-µ-SPE) procedure in combination with high-performance liquid chromatography (HPLC) with diode-array detection (DAD) for determining seven parabens in environmental waters (tap water, swimming pool water, and water coming from a spa pool), human urine (from two volunteers), and cosmetic creams (two commercial brands). Experimental parameters, such as nature and amount of MOF, sample volume, nature of elution solvent and its amount, vortex and centrifugation time, among others, were properly optimized. HKUST-1 was the most adequate MOF to work with. Detection limits for the overall method down to 0.1 μgL(-1) for butylparaben (BPB) and benzylparaben (BzPB) were obtained, with determination coefficients (R(2)) higher than 0.9966 for a range of 0.5-147 μgL(-1) (depending on the paraben), average relative recoveries (RR, in %) of 80.3% at the low spiked level (7 μgL(-1)), and relative standard deviation (RSD) values below 10% also at the low spiked level. The strength of the affinity between HKUST-1 and parabens was evaluated, and it ranged from 33.5% for isopropylparaben (iPPB) to 77.0% for isobutylparaben (iBPB). When analyzing complex environmental waters, RR values of 78%, inter-day precision values (as RSD) lower than 15%, and intra-day precision values lower than 7.8% were obtained, despite the observed matrix effect. When analyzing cosmetic creams, parabens were detected, with contents ranging from 0.14 ± 0.01 μgg(-1) for EPB in the healing cream analyzed to 1.12 ± 0.07 mgg(-1) for MPB in the mask cream analyzed, with precision values (RSD) lower than 12% and RR values from 63.7% for propylparaben (PPB) to 121% for iPPB. When analyzing human urine, no parabens were detected but the method could be performed with RSD values lower than 19%. These
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Hoogerheide, J G; Scott, R A
2005-01-30
A rapid and sensitive method for the determination of alkylating agents in complex reaction mixtures was developed and characterized. Analyses are based on the alkylation of 2-mercaptopyridine by the analyte; the derivative is separated by RP-HPLC and measured by fluorescence detection. When applied to the determination of dimethyl sulfate, the method is linear over four orders of magnitude: 0.01-10mugmL(-1). By using recrystallized 2-mercaptopyridine, quantitation limits of 10ngmL(-1) can be achieved. Precision of the assay is 2% R.S.D. in the 1-10mugmL(-1) range and about 15% R.S.D. at 10ngmL(-1). Studies on the pH dependence of the derivatization reaction were key to minimizing interference from the dimethyl sulfate degradation product, monomethyl sulfate, in quenched reaction samples.
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Li, Xingxing
2014-05-01
Earthquake monitoring and early warning system for hazard assessment and mitigation has traditional been based on seismic instruments. However, for large seismic events, it is difficult for traditional seismic instruments to produce accurate and reliable displacements because of the saturation of broadband seismometers and problematic integration of strong-motion data. Compared with the traditional seismic instruments, GPS can measure arbitrarily large dynamic displacements without saturation, making them particularly valuable in case of large earthquakes and tsunamis. GPS relative positioning approach is usually adopted to estimate seismic displacements since centimeter-level accuracy can be achieved in real-time by processing double-differenced carrier-phase observables. However, relative positioning method requires a local reference station, which might itself be displaced during a large seismic event, resulting in misleading GPS analysis results. Meanwhile, the relative/network approach is time-consuming, particularly difficult for the simultaneous and real-time analysis of GPS data from hundreds or thousands of ground stations. In recent years, several single-receiver approaches for real-time GPS seismology, which can overcome the reference station problem of the relative positioning approach, have been successfully developed and applied to GPS seismology. One available method is real-time precise point positioning (PPP) relied on precise satellite orbit and clock products. However, real-time PPP needs a long (re)convergence period, of about thirty minutes, to resolve integer phase ambiguities and achieve centimeter-level accuracy. In comparison with PPP, Colosimo et al. (2011) proposed a variometric approach to determine the change of position between two adjacent epochs, and then displacements are obtained by a single integration of the delta positions. This approach does not suffer from convergence process, but the single integration from delta positions to
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Directory of Open Access Journals (Sweden)
Ali Abdollahi, Ahad Bavili-Tabrizi
2016-03-01
Full Text Available Background: Cephalosporins are among the safest and the most effective broad-spectrum bactericidal antimicrobial agents which have been prescribed by the clinician as antibiotics. Thus, the developing of simple, sensitive and rapid analytical methods for their determination can be attractive and desirable. Methods: A simple, rapid and sensitive spectrofluorimetric method was developed for the determination of cefixime, cefalexin and ceftriaxone in pharmaceutical formulations. Proposed method is based on the oxidation of these cephalosporins with cerium (IV to produce cerium (III, and its fluorescence was monitored at 356 ± 3 nm after excitation at 254 ± 3 nm. Results: The variables effecting oxidation of each cephalosporin with cerum (IV were studied and optimized. Under the experimental conditions used, the calibration graphs were linear over the range 0.1-4 µg/mL. The limit of detection and limit of quantification were in the range 0.031-0.054 and 0.102-0.172 µg/mL, respectively. Intra- and inter-day assay precisions, expressed as the relative standard deviation (RSD, were lower than 5.6 and 6.8%, respectively. Conclusion: The proposed method was applied to the determination of studied cephalosporins in pharmaceutical formulations by good recoveries in the range 91-110%.
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Stolarczyk, Mariusz; Apola, Anna; Maślanka, Anna; Kwiecień, Anna; Opoka, Włodzimierz
2017-12-20
Applicability of derivative spectrophotometry for the determination of valsartan in the presence of a substance from the group of statins was checked. The obtained results indicate that the proposed method may be effective by using appropriate derivatives: for valsartan and fluvastatin - D1, D2 and D3, for valsartan and pravastatin - D1 and D3, for valsartan and atorvastatin - D2 and D3. The method was characterized by high sensitivity and accuracy. Linearity was maintained in the following ranges: 9.28-32.48 mg mL-1 for valsartan, 8.16-28.56 mg mL-1 f or fluvastatin, 14.40-39.90 mg mL-1 for atorvastatin and 9.60-48.00 mg mL-1 for pravastatin. Determination coefficients were in the range of 0.989-0.999 depending on the analyte and the order of derivative. The precision of the method was high with RSD from 0.1 to 2.5 % and recovery of individual components was within the range of 100 ± 5 %. The developed method was successfully applied to the determination of valsartan combined with fluvastatin, atorvastatin and pravastatin in laboratory prepared mixtures and in pharmaceutical preparations.
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Factors affecting the precision of bone mineral measurements
International Nuclear Information System (INIS)
Cormack, J.; Evil, C.A.
1990-01-01
This paper discusses some statistical aspects of absorptiometric bone mineral measurements. In particular, the contribution of photon counting statistics to overall precision is estimated, and methods available for carrying out statistical comparisons of bone loss and determining their precision are reviewed. The use of replicate measurements as a means of improving measurement precision is also discussed. 11 refs
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Directory of Open Access Journals (Sweden)
Oman Zuas
2016-09-01
Full Text Available An accurate gas chromatography coupled to a flame ionization detector (GC-FID method was validated for the simultaneous analysis of light hydrocarbons (C2-C4 in their gas mixture. The validation parameters were evaluated based on the ISO/IEC 17025 definition including method selectivity, repeatability, accuracy, linearity, limit of detection (LOD, limit of quantitation (LOQ, and ruggedness. Under the optimum analytical conditions, the analysis of gas mixture revealed that each target component was well-separated with high selectivity property. The method was also found to be precise and accurate. The method linearity was found to be high with good correlation coefficient values (R2 ≥ 0.999 for all target components. It can be concluded that the GC-FID developed method is reliable and suitable for determination of light C2-C4 hydrocarbons (including ethylene, propane, propylene, isobutane, and n-butane in their gas mixture. The validated method has successfully been applied to the estimation of hydrocarbons light C2-C4 hydrocarbons in natural gas samples, showing high performance repeatability with relative standard deviation (RSD less than 1.0% and good selectivity with no interference from other possible components could be observed.
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International Nuclear Information System (INIS)
Chitnis, R.T.; Dubey, S.C.
1976-01-01
A simple and rapid method for the determination of plutonium in plutonium nitrate solution and its application to the purex process solutions is discussed. The method involves the oxidation of plutonium to Pu(VI) with the help of argentic oxide followed by the destruction of the excess argentic oxide by means of sulphamic acid. The determination of plutonium is completed by adding ferrous ammonium sulphate solution which reduces Pu(VI) to Pu(IV) and titrating the excess ferrous with standard potassium dichromate solution using sodium diphenylamine sulphonate as the internal indicator. The effect of the various reagents add during the oxidation and reduction of plutonium, on the final titration has been investigated. The method works satisfactorily for the analysis of plutonium in the range of 0.5 to 5 mg. The precision of the method is found to be within 0.1%. (author)
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Bekiroglu, Somer; Myrberg, Olle; Ostman, Kristina; Ek, Marianne; Arvidsson, Torbjörn; Rundlöf, Torgny; Hakkarainen, Birgit
2008-08-05
A 1H-nuclear magnetic resonance (NMR) spectroscopy method for quantitative determination of benzethonium chloride (BTC) as a constituent of grapefruit seed extract was developed. The method was validated, assessing its specificity, linearity, range, and precision, as well as accuracy, limit of quantification and robustness. The method includes quantification using an internal reference standard, 1,3,5-trimethoxybenzene, and regarded as simple, rapid, and easy to implement. A commercial grapefruit seed extract was studied and the experiments were performed on spectrometers operating at two different fields, 300 and 600 MHz for proton frequencies, the former with a broad band (BB) probe and the latter equipped with both a BB probe and a CryoProbe. The concentration average for the product sample was 78.0, 77.8 and 78.4 mg/ml using the 300 BB probe, the 600MHz BB probe and CryoProbe, respectively. The standard deviation and relative standard deviation (R.S.D., in parenthesis) for the average concentrations was 0.2 (0.3%), 0.3 (0.4%) and 0.3mg/ml (0.4%), respectively.
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International Nuclear Information System (INIS)
Michalicek, Gregor
2015-01-01
Density functional theory (DFT) is the most widely-used first-principles theory for analyzing, describing and predicting the properties of solids based on the fundamental laws of quantum mechanics. The success of the theory is a consequence of powerful approximations to the unknown exchange and correlation energy of the interacting electrons and of sophisticated electronic structure methods that enable the computation of the density functional equations on a computer. A widely used electronic structure method is the full-potential linearized augmented plane-wave (FLAPW) method, that is considered to be one of the most precise methods of its kind and often referred to as a standard. Challenged by the demand of treating chemically and structurally increasingly more complex solids, in this thesis this method is revisited and extended along two different directions: (i) precision and (ii) efficiency. In the full-potential linearized augmented plane-wave method the space of a solid is partitioned into nearly touching spheres, centered at each atom, and the remaining interstitial region between the spheres. The Kohn-Sham orbitals, which are used to construct the electron density, the essential quantity in DFT, are expanded into a linearized augmented plane-wave basis, which consists of plane waves in the interstitial region and angular momentum dependent radial functions in the spheres. In this thesis it is shown that for certain types of materials, e.g., materials with very broad electron bands or large band gaps, or materials that allow the usage of large space-filling spheres, the variational freedom of the basis in the spheres has to be extended in order to represent the Kohn-Sham orbitals with high precision over a large energy spread. Two kinds of additional radial functions confined to the spheres, so-called local orbitals, are evaluated and found to successfully eliminate this error. A new efficient basis set is developed, named linearized augmented lattice
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High precision 3D coordinates location technology for pellet
International Nuclear Information System (INIS)
Fan Yong; Zhang Jiacheng; Zhou Jingbin; Tang Jun; Xiao Decheng; Wang Chuanke; Dong Jianjun
2010-01-01
In inertial confinement fusion (ICF) system, manual way has been used to collimate the pellet traditionally, which is time-consuming and low-level automated. A new method based on Binocular Vision is proposed, which can place the prospecting apparatus on the public diagnosis platform to reach relevant engineering target and uses the high precision two dimension calibration board. Iterative method is adopted to satisfy 0.1 pixel for corner extraction precision. Furthermore, SVD decomposition is used to remove the singularity corners and advanced Zhang's calibration method is applied to promote camera calibration precision. Experiments indicate that the RMS of three dimension coordinate measurement precision is 25 μm, and the max system RMS of distance measurement is better than 100 μm, satisfying the system index requirement. (authors)
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International Nuclear Information System (INIS)
Fernandes, E.A.N.
1981-01-01
The direct determinacao of calcium, copper, chomium, iron, magnesium, manganese, potassium, sodium and zinc in ethanol by atomic absorption spectrometry with, air-acetylene flame is proposed. Effects of fuel/oxidant ratio, burner height and water content in the samples were investigated in detail. The method allows the determition of the elements with good precision (r.s.d. -1 for the elements tested. (author) [pt
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Validating precision--how many measurements do we need?
ÅSberg, Arne; Solem, Kristine Bodal; Mikkelsen, Gustav
2015-10-01
A quantitative analytical method should be sufficiently precise, i.e. the imprecision measured as a standard deviation should be less than the numerical definition of the acceptable standard deviation. We propose that the entire 90% confidence interval for the true standard deviation shall lie below the numerical definition of the acceptable standard deviation in order to assure that the analytical method is sufficiently precise. We also present power function curves to ease the decision on the number of measurements to make. Computer simulation was used to calculate the probability that the upper limit of the 90% confidence interval for the true standard deviation was equal to or exceeded the acceptable standard deviation. Power function curves were constructed for different scenarios. The probability of failure to assure that the method is sufficiently precise increases with decreasing number of measurements and with increasing standard deviation when the true standard deviation is well below the acceptable standard deviation. For instance, the probability of failure is 42% for a precision experiment of 40 repeated measurements in one analytical run and 7% for 100 repeated measurements, when the true standard deviation is 80% of the acceptable standard deviation. Compared to the CLSI guidelines, validating precision according to the proposed principle is more reliable, but demands considerably more measurements. Using power function curves may help when planning studies to validate precision.
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Garrido Frenich, Antonia; Martín Fernández, María del Mar; Díaz Moreno, Laura; Martínez Vidal, Jose Lúis; López-Gutiérrez, Noelia
2012-01-01
A simple, rapid, and reliable multiresidue method to determine 84 pesticides in potato and carrot samples by ultra-performance liquid chromatography coupled to MS/MS has been developed and fully validated for routine analysis according to ISO/IEC 17025:2005. The method makes use of a buffered Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) sample preparation procedure based on a single extraction with acidified acetonitrile, followed by partitioning with salts. Chromatographic conditions were optimized in order to achieve a rapid separation in the multiple reaction monitoring mode. Performance characteristics of the method, including an estimation of measurement uncertainty using validation data, are reported for both matrixes. Calibration curves were linear from 0.010 to 0.150 mg/kg for most compounds. The LOD and LOQ were 0.006 and 0.010 mg/kg, respectively, except for fluorocloridone, fluquinconazol, and hexitiazox, which were 0.030 and 0.050 mg/kg, respectively. Recoveries obtained were in the range 70-116%, with intraday precision values < or = 20% RSD and interday precision values < or = 25% RSD at two different concentration levels. The overall uncertainty of the method was estimated at two concentrations as being lower than 34% in all cases. The method has been applied to the analysis of 70 vegetable samples, and imidacloprid and linuron were the pesticides most frequently found in potato and carrot commodities, respectively.
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Xie, Yunfei; Luo, Tian; Yang, Jing; Dong, Yuming
2018-01-01
Amino acids (AAs) in beer, red wine, and donkey-hide gelatin were rapidly determined by gradient LC elution from micellar LC to high submicellar LC. Mobile phase A was a 0.075 M sodium dodecyl sulfate solution containing 20 mM ammonium acetate with a pH value adjusted to 3.5 with acetic acid solution, and mobile phase B was acetonitrile. Optimized chromatographic conditions were as follows: mobile phase B increased from 25 to 60% (v/v) in 30 min and the use of a Venusil XBP C18 column (5 µm, 250 × 4.6 mm) as the stationary phase, with a column temperature of 35°C, flow rate of 1.2 mL/min, and detection wavelength of 266 nm. The results indicated good linearity (r2 ≥ 0.9924). The intraday precision of the retention time was RSD ≤ 1.1%, whereas interday was RSD ≤ 3.2%; intraday precision of the peak area was RSD ≤ 3.3%, whereas interday was RSD ≤ 4.9%. The range of recovery was 94.6-102.4%. The RSDs of the retention time for the AAs for the different samples were 0.04-0.31%.
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Raees Ahmad, Sufiyan Ahmad; Patil, Lalit; Mohammed Usman, Mohammed Rageeb; Imran, Mohammad; Akhtar, Rashid
2018-01-01
A simple rapid, accurate, precise, and reproducible validated reverse phase high performance liquid chromatography (HPLC) method was developed for the determination of Abacavir (ABAC) and Lamivudine (LAMI) in bulk and tablet dosage forms. The quantification was carried out using Symmetry Premsil C18 (250 mm × 4.6 mm, 5 μm) column run in isocratic way using mobile phase comprising methanol: water (0.05% orthophosphoric acid with pH 3) 83:17 v/v and a detection wavelength of 245 nm and injection volume of 20 μl, with a flow rate of 1 ml/min. In the developed method, the retention times of ABAC and LAMI were found to be 3.5 min and 7.4 min, respectively. The method was validated in terms of linearity, precision, accuracy, limits of detection, limits of quantitation, and robustness in accordance with the International Conference on Harmonization guidelines. The assay of the proposed method was found to be 99% - 101%. The recovery studies were also carried out and mean % recovery was found to be 99% - 101%. The % relative standard deviation from reproducibility was found to be performance liquid chromatography, UV: Ultraviolet, ICH: International Conference on Harmonization, ABAC: Abacavir, LAMI: Lamivudine, HIV: Human immunodeficiency virus, AIDS: Acquired immunodeficiency syndrome, NRTI: Nucleoside reverse transcriptase inhibitors, ARV: Antiretroviral, RSD: Relative standard deviation, RT: Retention time, SD: Standard deviation.
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Precision measurement of the e+e- → π+π-(γ) cross-section with ISR method
International Nuclear Information System (INIS)
Wang, L.L.
2009-05-01
Vacuum polarization integral involves the vector spectral functions which can be experimentally determined. As the dominant uncertainty source to the integral, the precision measurement of the cross section of e + e - → π + π - (γ) as a function of energy from 2π threshold to 3 GeV is performed by taking the ratio of e + e - → π + π - (γ) cross section to e + e - → μ + μ - (γ) cross section which are both measured with BABAR data using ISR method in one analysis. Besides that taking the ratio of the cross sections of the two processes can cancel several systematic uncertainties, the acceptance differences between data and Monte Carlo results are measured using the same data, and the corresponding corrections are applied on the efficiencies predicted by Monte Carlo method which can control the uncertainties. The achieved final uncertainty of the born cross section of e + e - → π + π - (γ) in ρ mass region (0.6 ∼ 0.9 GeV) is 0.54%. As a consequence of the new vacuum polarization calculation using the new precision result of the e + e - π + π - (γ) cross section, the impact on the standard model prediction of muon anomalous magnetic moment g - 2 is presented, which is also compared with other data based predictions and direct measurement. (author)
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Jaccoulet, E; Schweitzer-Chaput, A; Toussaint, B; Prognon, P; Caudron, E
2018-09-01
Compounding of monoclonal antibody (mAbs) constantly increases in hospital. Quality control (QC) of the compounded mAbs based on quantification and identification is required to prevent potential errors and fast method is needed to manage outpatient chemotherapy administration. A simple and ultra-fast (less than 30 s) method using flow injection analysis associated to least square matching method issued from the analyzer software was performed and evaluated for the routine hospital QC of three compounded mAbs: bevacizumab, infliximab and rituximab. The method was evaluated through qualitative and quantitative parameters. Preliminary analysis of the UV absorption and second derivative spectra of the mAbs allowed us to adapt analytical conditions according to the therapeutic range of the mAbs. In terms of quantitative QC, linearity, accuracy and precision were assessed as specified in ICH guidelines. Very satisfactory recovery was achieved and the RSD (%) of the intermediate precision were less than 1.1%. Qualitative analytical parameters were also evaluated in terms of specificity, sensitivity and global precision through a matrix of confusion. Results showed to be concentration and mAbs dependant and excellent (100%) specificity and sensitivity were reached within specific concentration range. Finally, routine application on "real life" samples (n = 209) from different batch of the three mAbs complied with the specifications of the quality control i.e. excellent identification (100%) and ± 15% of targeting concentration belonging to the calibration range. The successful use of the combination of second derivative spectroscopy and partial least square matching method demonstrated the interest of FIA for the ultra-fast QC of mAbs after compounding using matching method. Copyright © 2018 Elsevier B.V. All rights reserved.
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International Nuclear Information System (INIS)
Niki, Noboru; Fukuda, Hiroshi
1987-01-01
Our aim is to display the precise 3-D appearance of the brain based on data provided by CT images. For this purpose, we have developed a method of precisely forming surfaces from brain contours. The method expresses the brain surface as the sum of several partial surfaces. Each partial surface is individually constructed from respective parts of brain contours. The brain surface is finally made up of a superposition of partial surfaces. Two surface formation algorithms based on this principle are presented. One expresses the brain surface as the sum of a brain outline surface and sulcus surfaces. The other expresses the brain surface as the sum of surfaces in the same part of the brain. The effectiveness of these algorithms is shown by evaluation of contours obtained from dog and human brain samples and CT images. The latter algorithm is shown to be superior for high-resolution CT images. Optional cut-away views of the brain constructed by these algorithms are also shown. (author)
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Roberts, B. M.; Blewitt, G.; Dailey, C.; Derevianko, A.
2018-04-01
We analyze the prospects of employing a distributed global network of precision measurement devices as a dark matter and exotic physics observatory. In particular, we consider the atomic clocks of the global positioning system (GPS), consisting of a constellation of 32 medium-Earth orbit satellites equipped with either Cs or Rb microwave clocks and a number of Earth-based receiver stations, some of which employ highly-stable H-maser atomic clocks. High-accuracy timing data is available for almost two decades. By analyzing the satellite and terrestrial atomic clock data, it is possible to search for transient signatures of exotic physics, such as "clumpy" dark matter and dark energy, effectively transforming the GPS constellation into a 50 000 km aperture sensor array. Here we characterize the noise of the GPS satellite atomic clocks, describe the search method based on Bayesian statistics, and test the method using simulated clock data. We present the projected discovery reach using our method, and demonstrate that it can surpass the existing constrains by several order of magnitude for certain models. Our method is not limited in scope to GPS or atomic clock networks, and can also be applied to other networks of precision measurement devices.
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Development and validation of Ketorolac Tromethamine in eye drop formulation by RP-HPLC method
Directory of Open Access Journals (Sweden)
G. Sunil
2017-02-01
Full Text Available A simple, precise and accurate method was developed and validated for analysis of Ketorolac Tromethamine in eye drop formulation. An isocratic HPLC analysis was performed on Kromosil C18 column (150 cm × 4.6 mm × 5 μm. The compound was separated with the mixture of methanol and ammonium dihydrogen phosphate buffer in the ratio of 55:45 V/V, pH 3.0 was adjusted with O-phosphoric acid as the mobile phase at flow of 1.5 mL min−1. UV detection was performed at 314 nm using photo diode array detection. The retention time was found to be 6.01 min. The system suitability parameters such as theoretical plate count, tailing and percentage RSD between six standard injections were within the limit. The method was validated according to ICH guidelines. Calibrations were linear over the concentration range of 50–150 μg mL−1 as indicated by correlation coefficient (r of 0.999. The robustness of the method was evaluated by deliberately altering the chromatographic conditions. The developed method can be applicable for routine quantitative analysis.
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Directory of Open Access Journals (Sweden)
Nidal Batrawi
2017-02-01
Full Text Available Medroxyprogesterone acetate is widely used in veterinary medicine as intravaginal dosage for the synchronization of breeding cycle in ewes and goats. The main goal of this study was to develop reverse-phase high-performance liquid chromatography method for the quantification of medroxyprogesterone acetate in veterinary vaginal sponges. A single high-performance liquid chromatography/UV isocratic run was used for the analytical assay of the active ingredient medroxyprogesterone. The chromatographic system consisted of a reverse-phase C18 column as the stationary phase and a mixture of 60% acetonitrile and 40% potassium dihydrogen phosphate buffer as the mobile phase; the pH was adjusted to 5.6. The method was validated according to the International Council for Harmonisation (ICH guidelines. Forced degradation studies were also performed to evaluate the stability-indicating properties and specificity of the method. Medroxyprogesterone was eluted at 5.9 minutes. The linearity of the method was confirmed in the range of 0.0576 to 0.1134 mg/mL ( R 2 > 0.999. The limit of quantification was shown to be 3.9 µg/mL. Precision and accuracy ranges were found to be %RSD <0.2 and 98% to 102%, respectively. Medroxyprogesterone capacity factor value of 2.1, tailing factor value of 1.03, and resolution value of 3.9 were obtained in accordance with ICH guidelines. Based on the obtained results, a rapid, precise, accurate, sensitive, and cost-effective analysis procedure was proposed for quantitative determination of medroxyprogesterone in vaginal sponges. This analytical method is the only available method to analyse medroxyprogesterone in veterinary intravaginal dosage form.
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Agley, Chibeza C.; Velloso, Cristiana P.; Lazarus, Norman R.
2012-01-01
The accurate measurement of the morphological characteristics of cells with nonuniform conformations presents difficulties. We report here a straightforward method using immunofluorescent staining and the commercially available imaging program Adobe Photoshop, which allows objective and precise information to be gathered on irregularly shaped cells. We have applied this measurement technique to the analysis of human muscle cells and their immunologically marked intracellular constituents, as these cells are prone to adopting a highly branched phenotype in culture. Use of this method can be used to overcome many of the long-standing limitations of conventional approaches for quantifying muscle cell size in vitro. In addition, wider applications of Photoshop as a quantitative and semiquantitative tool in immunocytochemistry are explored. PMID:22511600
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Directory of Open Access Journals (Sweden)
Hérida R. N. Salgado
2011-08-01
Full Text Available Orbifloxacin is a fluoroquinolone with broad-spectrum antimicrobial activity, and belongs to the third generation of quinolones. Regarding the quality control of medicines, a validated microbiological assay for determination of orbifloxacin in pharmaceutical formulations has not as yet been reported. For this purpose, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method to quantify orbifloxacin in tablet formulations. The assay is based on the inhibitory effect of orbifloxacin upon the strain of Staphylococcus aureus ATCC 25923 used as test microorganism. The results were treated statistically by analysis of variance and were found to be linear (r = 0.9992 in the selected range of 16.0–64.0 μg/mL, precise with relative standard deviation (RSD of repeatability intraday = 2.88%, intermediate precision RSD = 3.33%, and accurate (100.31%. The results demonstrated the validity of the proposed bioassay, which allows reliable orbifloxacin quantitation in pharmaceutical samples and therefore can be used as a useful alternative methodology for the routine quality control of this medicine.
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Precision medicine for psychopharmacology: a general introduction.
Shin, Cheolmin; Han, Changsu; Pae, Chi-Un; Patkar, Ashwin A
2016-07-01
Precision medicine is an emerging medical model that can provide accurate diagnoses and tailored therapeutic strategies for patients based on data pertaining to genes, microbiomes, environment, family history and lifestyle. Here, we provide basic information about precision medicine and newly introduced concepts, such as the precision medicine ecosystem and big data processing, and omics technologies including pharmacogenomics, pharamacometabolomics, pharmacoproteomics, pharmacoepigenomics, connectomics and exposomics. The authors review the current state of omics in psychiatry and the future direction of psychopharmacology as it moves towards precision medicine. Expert commentary: Advances in precision medicine have been facilitated by achievements in multiple fields, including large-scale biological databases, powerful methods for characterizing patients (such as genomics, proteomics, metabolomics, diverse cellular assays, and even social networks and mobile health technologies), and computer-based tools for analyzing large amounts of data.
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Moein, Elham; Hajimehdipoor, Homa; Toliyat, Tayebeh; Choopani, Rasool; Hamzeloo-Moghadam, Maryam
2017-08-29
Currently, people are more interested to traditional medicine. The traditional formulations should be converted to modern drug delivery systems to be more acceptable for the patients. In the present investigation, a poly herbal medicine "Ayarij-e-Faiqra" (AF) based on Iranian traditional medicine (ITM) has been formulated and its quality control parameters have been developed. The main ingredients of AF including barks of Cinnamomum zeylanicum Blume and Cinnamomum cassia J. Presl, the rhizomes of Nardostachys jatamansi DC., the fruits of Piper cubeba L.f., the flowers of Rosa damascena Herrm., the oleo gum resin of Pistacia terebinthus L. and Aloe spp. dried juice were powdered and used for preparing seven tablet formulations of the herbal mixture. Flowability of the different formulated powders was examined and the best formulations were selected (F6&F7). The tablets were prepared from the selected formulations compared according to the physical characteristics and finally, F7 was selected and coated. Physicochemical characters of core and coated AF tablets were determined and the HPLC method for quantitation of aloin as a marker of tablets was selected and verified according to selectivity, linearity, precision, recovery, LOD and LOQ. The results showed that core and coated AF tablets were in agreement with USP requirements for herbal drugs. They had acceptable appearance, disintegration time, friability, hardness, dissolution behavior, weight variation and content uniformity. The amount of aloin in tablets was found 123.1 mg/tab. The HPLC method for aloin determination in AF tablets was verified according to selectivity, linearity (5-500 μg/ml, r 2 :0.9999), precision (RSD: 1.62%), recovery (108.0%), LOD & LOQ (0.0053 & 0.0161 μg/ml). The formulated tablets could be a good substitute for powder and capsules of AF in ITM clinics with a feasible and precise method for its quality control. Ayarij-e-Faiqra formulation.
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A Method for Precision Closed-Loop Irrigation Using a Modified PID Control Algorithm
Goodchild, Martin; Kühn, Karl; Jenkins, Malcolm; Burek, Kazimierz; Dutton, Andrew
2016-04-01
The benefits of closed-loop irrigation control have been demonstrated in grower trials which show the potential for improved crop yields and resource usage. Managing water use by controlling irrigation in response to soil moisture changes to meet crop water demands is a popular approach but requires knowledge of closed-loop control practice. In theory, to obtain precise closed-loop control of a system it is necessary to characterise every component in the control loop to derive the appropriate controller parameters, i.e. proportional, integral & derivative (PID) parameters in a classic PID controller. In practice this is often difficult to achieve. Empirical methods are employed to estimate the PID parameters by observing how the system performs under open-loop conditions. In this paper we present a modified PID controller, with a constrained integral function, that delivers excellent regulation of soil moisture by supplying the appropriate amount of water to meet the needs of the plant during the diurnal cycle. Furthermore, the modified PID controller responds quickly to changes in environmental conditions, including rainfall events which can result in: controller windup, under-watering and plant stress conditions. The experimental work successfully demonstrates the functionality of a constrained integral PID controller that delivers robust and precise irrigation control. Coir substrate strawberry growing trial data is also presented illustrating soil moisture control and the ability to match water deliver to solar radiation.
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Directory of Open Access Journals (Sweden)
Rafaela Zielinski Cavalheiro de Meira
2017-01-01
Full Text Available Dapagliflozin was the first of its class (inhibitors of sodium-glucose cotransporter to be approved in Europe, USA, and Brazil. As the drug was recently approved, there is the need for research on analytical methods, including dissolution studies for the quality evaluation and assurance of tablets. The dissolution methodology was developed with apparatus II (paddle in 900 mL of medium (simulated gastric fluid, pH 1.2, temperature set at 37±0.5°C, and stirring speed of 50 rpm. For the quantification, a spectrophotometric (λ=224 nm method was developed and validated. In validation studies, the method proved to be specific and linear in the range from 0.5 to 15 μg·mL−1 (r2=0.998. The precision showed results with RSD values lower than 2%. The recovery of 80.72, 98.47, and 119.41% proved the accuracy of the method. Through a systematic approach by applying Factorial 23, the robustness of the method was confirmed (p>0.05. The studies of commercial tablets containing 5 or 10 mg demonstrated that they could be considered similar through f1, f2, and dissolution efficiency analyses. Also, the developed method can be used for the quality evaluation of dapagliflozin tablets and can be considered as a scientific basis for future official pharmacopoeial methods.
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The Ramsey method in high-precision mass spectrometry with Penning traps Experimental results
George, S; Herfurth, F; Herlert, A; Kretzschmar, M; Nagy, S; Schwarz, S; Schweikhard, L; Yazidjian, C
2007-01-01
The highest precision in direct mass measurements is obtained with Penning trap mass spectrometry. Most experiments use the interconversion of the magnetron and cyclotron motional modes of the stored ion due to excitation by external radiofrequency-quadrupole fields. In this work a new excitation scheme, Ramsey's method of time-separated oscillatory fields, has been successfully tested. It has been shown to reduce significantly the uncertainty in the determination of the cyclotron frequency and thus of the ion mass of interest. The theoretical description of the ion motion excited with Ramsey's method in a Penning trap and subsequently the calculation of the resonance line shapes for different excitation times, pulse structures, and detunings of the quadrupole field has been carried out in a quantum mechanical framework and is discussed in detail in the preceding article in this journal by M. Kretzschmar. Here, the new excitation technique has been applied with the ISOLTRAP mass spectrometer at ISOLDE/CERN fo...
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Directory of Open Access Journals (Sweden)
Xiaofei Liu
2018-04-01
Full Text Available The high acidity and complex components of Hibiscus sabdariffa have provided major challenges for sensitive determination of trace aflatoxins. In this study, sample pretreatment of H. sabdariffa was systematically developed for sensitive high performance liquid chromatography-fluorescence detection (HPLC-FLD after ultrasonication-assisted extraction, immunoaffinity column (IAC clean-up and on-line post-column photochemical derivatization (PCD. Aflatoxins B1, B2, G1, G2 were extracted from samples by using methanol/water (70:30, v/v with the addition of NaCl. The solutions were diluted 1:8 with 0.1 M phosphate buffer (pH 8.0 to negate the issues of high acidity and matrix interferences. The established method was validated with satisfactory linearity (R > 0.999, sensitivity (limits of detection (LODs and limits of quantitation (LOQs of 0.15–0.65 and 0.53–2.18 μg/kg, respectively, precision (RSD <11%, stability (RSD of 0.2–3.6%, and accuracy (recovery rates of 86.0–102.3%, which all met the stipulated analytical requirements. Analysis of 28 H. sabdariffa samples indicated that one sample incubated with Aspergillus flavus was positive with aflatoxin B1 (AFB1 at 3.11 μg/kg. The strategy developed in this study also has the potential to reliably extract and sensitively detect more mycotoxins in other complex acidic matrices, such as traditional Chinese medicines, foodstuffs, etc.
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Gautam, Raju; Srivastava, Amit; Jachak, Sanjay M
2011-01-01
Rumex nepalensis contains mainly anthraquinone and naphthalene derivatives. Although HPLC methods have been reported for the analysis of anthraquinones, neither a phytochemical analysis of Rumex species nor the simultaneous determination of anthraquinone and naphthalene derivatives in other samples has been reported so far. To develop and validate a HPLC method for the simultaneous determination of anthraquinone and naphthalene derivatives in R. nepalensis roots. Anthraquinones and naphthalenes were extracted from R. nepalensis roots by three methods (reflux, ultrasonication and pressurized liquid extraction) using methanol. Separation was achieved on an RP C₁₈ column with a gradient mobile phase consisting of 0.05% orthophosphoric acid in water (solvent A) and methanol (solvent B) using a UV detector (254 nm). Small differences were observed in the contents of anthraquinone and naphthalene derivatives extracted by the three methods. Chrysophanol-8-O-β-D-glucopyranoside and nepodin were detected as major constituents. The method showed a good linearity (r² > 0.9992), high precision (RSD anthraquinones and naphthalenes in R. nepalensis and other Rumex species for both quality control as well as routine analytical purposes. Copyright © 2010 John Wiley & Sons, Ltd.
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Directory of Open Access Journals (Sweden)
Fei Liu
2017-01-01
Full Text Available With the availability of the third civil signal in the Global Positioning System, triple-frequency Precise Point Positioning ambiguity resolution methods have drawn increasing attention due to significantly reduced convergence time. However, the corresponding triple-frequency based precise clock products are not widely available and adopted by applications. Currently, most precise products are generated based on ionosphere-free combination of dual-frequency L1/L2 signals, which however are not consistent with the triple-frequency ionosphere-free carrier-phase measurements, resulting in inaccurate positioning and unstable float ambiguities. In this study, a GPS triple-frequency PPP ambiguity resolution method is developed using the widely used dual-frequency based clock products. In this method, the interfrequency clock biases between the triple-frequency and dual-frequency ionosphere-free carrier-phase measurements are first estimated and then applied to triple-frequency ionosphere-free carrier-phase measurements to obtain stable float ambiguities. After this, the wide-lane L2/L5 and wide-lane L1/L2 integer property of ambiguities are recovered by estimating the satellite fractional cycle biases. A test using a sparse network is conducted to verify the effectiveness of the method. The results show that the ambiguity resolution can be achieved in minutes even tens of seconds and the positioning accuracy is in decimeter level.
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Microhartree precision in density functional theory calculations
Gulans, Andris; Kozhevnikov, Anton; Draxl, Claudia
2018-04-01
To address ultimate precision in density functional theory calculations we employ the full-potential linearized augmented plane-wave + local-orbital (LAPW + lo) method and justify its usage as a benchmark method. LAPW + lo and two completely unrelated numerical approaches, the multiresolution analysis (MRA) and the linear combination of atomic orbitals, yield total energies of atoms with mean deviations of 0.9 and 0.2 μ Ha , respectively. Spectacular agreement with the MRA is reached also for total and atomization energies of the G2-1 set consisting of 55 molecules. With the example of α iron we demonstrate the capability of LAPW + lo to reach μ Ha /atom precision also for periodic systems, which allows also for the distinction between the numerical precision and the accuracy of a given functional.
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Directory of Open Access Journals (Sweden)
Mingmei Yuan
Full Text Available An LC-MS/MS assay based on a signature peptide was developed and fully validated for the quantitation of bovine lactoferrin in infant formulas. Three unreported signature peptides were derived and identified from the tryptic peptides of bovine lactoferrin. The peptide ETTVFENLPEK was used for quantification based on assay performance. The blank matrix camel milk powder and bovine lactoferrin protein standards were mixed and spiked with stable isotope-labeled internal standard to establish a calibration curve. The established method was extensively validated by determining the linearity (R2 > 0.999, sensitivity (limit of quantitation, 0.16 mg/100 g, recovery (83.1-91.6%, precision (RSD < 5.4% and repeatability (RSD < 7.7%. To validate the applicability of the method, four different brands of infant formulas in China were analysed. The acquired contents of bovine lactoferrin were 52.60-150.56 mg/100 g.
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International Nuclear Information System (INIS)
Liu Quanwei; Luo Zhongyan; Zhu Haiqiao; Wu Jizong
2007-01-01
For high radioactivity level of dissolved solution of spent fuel and the solution of uranium product, radioactive hazard must be considered and reduced as low as possible during accurate determination of uranium. In this work automatic potentiometric titration was applied and the sample only 10 mg of uranium contained was taken in order to reduce the harm of analyzer suffered from the radioactivity. RSD<0.06%, at the same time the result can be corrected for more reliable and accurate measurement. The determination method can effectively reduce the harm of analyzer suffered from the radioactivity, and meets the requirement of reliable accurate measurement of uranium. (authors)
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High Precision GNSS Guidance for Field Mobile Robots
Directory of Open Access Journals (Sweden)
Ladislav Jurišica
2012-11-01
Full Text Available In this paper, we discuss GNSS (Global Navigation Satellite System guidance for field mobile robots. Several GNSS systems and receivers, as well as multiple measurement methods and principles of GNSS systems are examined. We focus mainly on sources of errors and investigate diverse approaches for precise measuring and effective use of GNSS systems for real-time robot localization. The main body of the article compares two GNSS receivers and their measurement methods. We design, implement and evaluate several mathematical methods for precise robot localization.
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Precise Truss Assembly Using Commodity Parts and Low Precision Welding
Komendera, Erik; Reishus, Dustin; Dorsey, John T.; Doggett, W. R.; Correll, Nikolaus
2014-01-01
Hardware and software design and system integration for an intelligent precision jigging robot (IPJR), which allows high precision assembly using commodity parts and low-precision bonding, is described. Preliminary 2D experiments that are motivated by the problem of assembling space telescope optical benches and very large manipulators on orbit using inexpensive, stock hardware and low-precision welding are also described. An IPJR is a robot that acts as the precise "jigging", holding parts of a local structure assembly site in place, while an external low precision assembly agent cuts and welds members. The prototype presented in this paper allows an assembly agent (for this prototype, a human using only low precision tools), to assemble a 2D truss made of wooden dowels to a precision on the order of millimeters over a span on the order of meters. The analysis of the assembly error and the results of building a square structure and a ring structure are discussed. Options for future work, to extend the IPJR paradigm to building in 3D structures at micron precision are also summarized.
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Czech Academy of Sciences Publication Activity Database
Strakoš, Zdeněk; Tichý, Petr
2002-01-01
Roč. 13, - (2002), s. 56-80 ISSN 1068-9613 R&D Projects: GA ČR GA201/02/0595 Institutional research plan: AV0Z1030915 Keywords : conjugate gradient method * Gauss kvadrature * evaluation of convergence * error bounds * finite precision arithmetic * rounding errors * loss of orthogonality Subject RIV: BA - General Mathematics Impact factor: 0.565, year: 2002 http://etna.mcs.kent.edu/volumes/2001-2010/vol13/abstract.php?vol=13&pages=56-80
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Krüger, S; Hüsken, L; Fornasari, R; Scainelli, I; Morlock, G E
2017-12-22
Quantitative effect-directed profiles of 77 industrially and freshly extracted botanicals like herbs, spices, vegetables and fruits, widely used as food ingredients, dietary supplements or traditional medicine, gave relevant information on their quality. It allows the assessment of food, dietary supplements and phytomedicines with regard to potential health-promoting activities. In contrary to sum parameter assays and targeted analysis, chromatography combined with effect-directed analysis allows fast assignment of single active compounds and evaluation of their contribution to the overall activity, originating from a food or botanical sample. High-performance thin-layer chromatography was hyphenated with UV/Vis/FLD detection and effect-directed analysis, using the 2,2-diphenyl-1-picrylhydrazyl radical, Gram-negative Aliivibrio fischeri, Gram-positive Bacillus subtilis, acetylcholinesterase and tyrosinase assays. Bioactive compounds of interest were eluted using an elution head-based interface and further characterized by electrospray ionization (high-resolution) mass spectrometry. This highly streamlined workflow resulted in a hyphenated HPTLC-UV/Vis/FLD-EDA-ESI + /ESI - -(HR)MS method. The excellent quantification power of the method was shown on three compounds. For rosmarinic acid, contents ranged from 4.5mg/g (rooibos) to 32.6mg/g (rosemary), for kaempferol-3-glucoside from 0.6mg/g (caraway) to 4.4mg/g (wine leaves), and for quercetin-3-glucoside from 1.1mg/g (hawthorn leaves) to 17.7mg/g (thyme). Three mean repeatabilities (%RSD) over 18 quantifications for the three compounds were ≤2.2% and the mean intermediate precision over three different days (%RSD, n=3) was 5.2%. Copyright © 2017 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Mariel Colmán-Martínez
2016-01-01
Full Text Available A simple and accurate reversed phase high-performance liquid chromatography coupled with diode array detector (HPLC-DAD method for simultaneously determining and quantifying the antioxidants carotenes, xanthophylls, and retinol in human plasma is presented in this paper. Compounds were extracted with hexane, a C30 column, and a mobile phase of methanol, methyl tert-butyl ether, and water were used for the separation of the compounds. A total of 8 carotenoids, 3 Z-β-carotene isomers, and 1 fat-soluble vitamin (retinol were resolved within 72 min at a flow rate of 0.6 mL/min. Detection was achieved at 450 nm for carotenoids and 330 nm for retinol. To evaluate the effectiveness of themethod, it has been applied to an intervention study conducted on eight volunteers. Results. Limits of detection were between 0.1 μg/mL for lycopene and astaxanthin and 1.3 μg/mL for 15-Z-β-carotene. Recoveries were ranged between 89% and 113% for α-carotene and astaxanthin, respectively. Accuracy was between 90.7% and 112.2% and precision was between 1% and 15% RSD. In human plasma samples compounds studied were identified besides three lycopene isomers, demonstrated to be suitable for application in dietary intervention studies. Conclusions. Due to its accuracy, precision, selectivity, and reproducibility, this method is suitable to dietary habits and/or antioxidants status studies.
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Colmán-Martínez, Mariel; Martínez-Huélamo, Miriam; Miralles, Esther; Estruch, Ramón; Lamuela-Raventós, Rosa M
2015-01-01
A simple and accurate reversed phase high-performance liquid chromatography coupled with diode array detector (HPLC-DAD) method for simultaneously determining and quantifying the antioxidants carotenes, xanthophylls, and retinol in human plasma is presented in this paper. Compounds were extracted with hexane, a C30 column, and a mobile phase of methanol, methyl tert-butyl ether, and water were used for the separation of the compounds. A total of 8 carotenoids, 3 Z-β-carotene isomers, and 1 fat-soluble vitamin (retinol) were resolved within 72 min at a flow rate of 0.6 mL/min. Detection was achieved at 450 nm for carotenoids and 330 nm for retinol. To evaluate the effectiveness of themethod, it has been applied to an intervention study conducted on eight volunteers. Results. Limits of detection were between 0.1 μg/mL for lycopene and astaxanthin and 1.3 μg/mL for 15-Z-β-carotene. Recoveries were ranged between 89% and 113% for α-carotene and astaxanthin, respectively. Accuracy was between 90.7% and 112.2% and precision was between 1% and 15% RSD. In human plasma samples compounds studied were identified besides three lycopene isomers, demonstrated to be suitable for application in dietary intervention studies. Conclusions. Due to its accuracy, precision, selectivity, and reproducibility, this method is suitable to dietary habits and/or antioxidants status studies.
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Accuracy and Precision of a Plane Wave Vector Flow Imaging Method in the Healthy Carotid Artery
DEFF Research Database (Denmark)
Jensen, Jonas; Villagómez Hoyos, Carlos Armando; Traberg, Marie Sand
2018-01-01
The objective of the study described here was to investigate the accuracy and precision of a plane wave 2-D vector flow imaging (VFI) method in laminar and complex blood flow conditions in the healthy carotid artery. The approach was to study (i) the accuracy for complex flow by comparing...... of laminar flow in vivo. The precision in vivo was calculated as the mean standard deviation (SD) of estimates aligned to the heart cycle and was highest in the center of the common carotid artery (SD = 3.6% for velocity magnitudes and 4.5° for angles) and lowest in the external branch and for vortices (SD...... the velocity field from a computational fluid dynamics (CFD) simulation to VFI estimates obtained from the scan of an anthropomorphic flow phantom and from an in vivo scan; (ii) the accuracy for laminar unidirectional flow in vivo by comparing peak systolic velocities from VFI with magnetic resonance...
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Paziewski, Jacek; Sieradzki, Rafal; Baryla, Radoslaw
2018-03-01
This paper provides the methodology and performance assessment of multi-GNSS signal processing for the detection of small-scale high-rate dynamic displacements. For this purpose, we used methods of relative (RTK) and absolute positioning (PPP), and a novel direct signal processing approach. The first two methods are recognized as providing accurate information on position in many navigation and surveying applications. The latter is an innovative method for dynamic displacement determination with the use of GNSS phase signal processing. This method is based on the developed functional model with parametrized epoch-wise topocentric relative coordinates derived from filtered GNSS observations. Current regular kinematic PPP positioning, as well as medium/long range RTK, may not offer coordinate estimates with subcentimeter precision. Thus, extended processing strategies of absolute and relative GNSS positioning have been developed and applied for displacement detection. The study also aimed to comparatively analyze the developed methods as well as to analyze the impact of combined GPS and BDS processing and the dependence of the results of the relative methods on the baseline length. All the methods were implemented with in-house developed software allowing for high-rate precise GNSS positioning and signal processing. The phase and pseudorange observations collected with a rate of 50 Hz during the field test served as the experiment’s data set. The displacements at the rover station were triggered in the horizontal plane using a device which was designed and constructed to ensure a periodic motion of GNSS antenna with an amplitude of ~3 cm and a frequency of ~4.5 Hz. Finally, a medium range RTK, PPP, and direct phase observation processing method demonstrated the capability of providing reliable and consistent results with the precision of the determined dynamic displacements at the millimeter level. Specifically, the research shows that the standard deviation of
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Xuan, Tong; Zhang, J Allen; Ahmad, Imran
2006-05-03
A simple HPLC method was developed for quantification of SN-38, 7-ethyl-10-hydroxycamptothecin, in a novel liposome-based formulation (LE-SN38). The chromatographic separation was achieved on an Agilent Zorbax SB-C18 (4.6 mmx250 mm, 5 microm) analytical column using a mobile phase consisting of a mixture of NaH2PO4 (pH 3.1, 25 mM) and acetonitrile (50:50, v/v). SN-38 was detected at UV wavelength of 265 nm and quantitatively determined using an external calibration method. The limit of detection (LOD) and limit of quantitation (LOQ) were found to be 0.05 and 0.25 microg/mL, respectively. The individual spike recovery of SN-38 ranged from 100 to 101%. The percent of relative standard deviation (%R.S.D.) of intra-day and inter-day analyses were less than 1.6%. The method validation results confirmed that the method is specific, linear, accurate, precise, robust and sensitive for its intended use. The current method was successfully applied to the determination of SN-38 content and drug entrapment efficiency in liposome-based formulation, LE-SN38 during early stage formulation development.
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Toro Matamoros, Raúl Mario del; Schmittdiel, Michael Charles; Haber Guerra, Rodolfo E.
2008-01-01
[EN] The invention relates to a method for detecting, in real time, an imbalance of the head in a high-precision rotary mechanism, and to the system for carrying out said method. The method comprises the following steps: a) the signal X(t) corresponding to the acceleration of the vibrations of the head is acquired by means of an acquisition means at a sampling rate FS; and b) it is determined, from the signal X(t) obtained, whether the head is imbalanced.
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Automating methods to improve precision in Monte-Carlo event generation for particle colliders
International Nuclear Information System (INIS)
Gleisberg, Tanju
2008-01-01
The subject of this thesis was the development of tools for the automated calculation of exact matrix elements, which are a key for the systematic improvement of precision and confidence for theoretical predictions. Part I of this thesis concentrates on the calculations of cross sections at tree level. A number of extensions have been implemented in the matrix element generator AMEGIC++, namely new interaction models such as effective loop-induced couplings of the Higgs boson with massless gauge bosons, required for a number of channels for the Higgs boson search at LHC and anomalous gauge couplings, parameterizing a number of models beyond th SM. Further a special treatment to deal with complicated decay chains of heavy particles has been constructed. A significant effort went into the implementation of methods to push the limits on particle multiplicities. Two recursive methods have been implemented, the Cachazo-Svrcek-Witten recursion and the colour dressed Berends-Giele recursion. For the latter the new module COMIX has been added to the SHERPA framework. The Monte-Carlo phase space integration techniques have been completely revised, which led to significantly reduced statistical error estimates when calculating cross sections and a greatly improved unweighting efficiency for the event generation. Special integration methods have been developed to cope with the newly accessible final states. The event generation framework SHERPA directly benefits from those new developments, improving the precision and the efficiency. Part II was addressed to the automation of QCD calculations at next-to-leading order. A code has been developed, that, for the first time fully automates the real correction part of a NLO calculation. To calculate the correction for a m-parton process obeying the Catani-Seymour dipole subtraction method the following components are provided: 1. the corresponding m+1-parton tree level matrix elements, 2. a number dipole subtraction terms to remove
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Automating methods to improve precision in Monte-Carlo event generation for particle colliders
Energy Technology Data Exchange (ETDEWEB)
Gleisberg, Tanju
2008-07-01
The subject of this thesis was the development of tools for the automated calculation of exact matrix elements, which are a key for the systematic improvement of precision and confidence for theoretical predictions. Part I of this thesis concentrates on the calculations of cross sections at tree level. A number of extensions have been implemented in the matrix element generator AMEGIC++, namely new interaction models such as effective loop-induced couplings of the Higgs boson with massless gauge bosons, required for a number of channels for the Higgs boson search at LHC and anomalous gauge couplings, parameterizing a number of models beyond th SM. Further a special treatment to deal with complicated decay chains of heavy particles has been constructed. A significant effort went into the implementation of methods to push the limits on particle multiplicities. Two recursive methods have been implemented, the Cachazo-Svrcek-Witten recursion and the colour dressed Berends-Giele recursion. For the latter the new module COMIX has been added to the SHERPA framework. The Monte-Carlo phase space integration techniques have been completely revised, which led to significantly reduced statistical error estimates when calculating cross sections and a greatly improved unweighting efficiency for the event generation. Special integration methods have been developed to cope with the newly accessible final states. The event generation framework SHERPA directly benefits from those new developments, improving the precision and the efficiency. Part II was addressed to the automation of QCD calculations at next-to-leading order. A code has been developed, that, for the first time fully automates the real correction part of a NLO calculation. To calculate the correction for a m-parton process obeying the Catani-Seymour dipole subtraction method the following components are provided: 1. the corresponding m+1-parton tree level matrix elements, 2. a number dipole subtraction terms to remove
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High-Precision Registration of Point Clouds Based on Sphere Feature Constraints
Directory of Open Access Journals (Sweden)
Junhui Huang
2016-12-01
Full Text Available Point cloud registration is a key process in multi-view 3D measurements. Its precision affects the measurement precision directly. However, in the case of the point clouds with non-overlapping areas or curvature invariant surface, it is difficult to achieve a high precision. A high precision registration method based on sphere feature constraint is presented to overcome the difficulty in the paper. Some known sphere features with constraints are used to construct virtual overlapping areas. The virtual overlapping areas provide more accurate corresponding point pairs and reduce the influence of noise. Then the transformation parameters between the registered point clouds are solved by an optimization method with weight function. In that case, the impact of large noise in point clouds can be reduced and a high precision registration is achieved. Simulation and experiments validate the proposed method.
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Filip, Miuţa; Vlassa, Mihaela; Coman, Virginia; Halmagyi, Adela
2016-05-15
A high performance liquid chromatography method with refractive index detection (HPLC-RI), for simultaneous determination of glucose, fructose, sucrose and sorbitol in leaf and/or apple peel samples from nine apple (Malus domestica Borkh.) cultivars and rootstocks, originating from a germplasm collection, has been developed and validated. Box-Behnken design of response surface methodology was applied for the method optimization. The Carbosep Coregel 87H3 column was used under the optimum conditions predicted: mobile phase of H2SO4 0.005 mol L(-1) solution, flow rate of 0.3 mL min(-1) and column temperature of 35°C. The method was validated for linearity (R(2)>0.99), limits of detection (2.67-4.83 μg mL(-1)) and quantification (8.9-16.1 μg mL(-1)), precision (%RSD<5.05) and recovery (93.94-103.06%) and satisfactory results obtained. The sugars content varied across micropropagated plants in vitro, plants regenerated after cryostorage, growing trees in vivo, and fruit peel. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Estimating maneuvers for precise relative orbit determination using GPS
Allende-Alba, Gerardo; Montenbruck, Oliver; Ardaens, Jean-Sébastien; Wermuth, Martin; Hugentobler, Urs
2017-01-01
Precise relative orbit determination is an essential element for the generation of science products from distributed instrumentation of formation flying satellites in low Earth orbit. According to the mission profile, the required formation is typically maintained and/or controlled by executing maneuvers. In order to generate consistent and precise orbit products, a strategy for maneuver handling is mandatory in order to avoid discontinuities or precision degradation before, after and during maneuver execution. Precise orbit determination offers the possibility of maneuver estimation in an adjustment of single-satellite trajectories using GPS measurements. However, a consistent formulation of a precise relative orbit determination scheme requires the implementation of a maneuver estimation strategy which can be used, in addition, to improve the precision of maneuver estimates by drawing upon the use of differential GPS measurements. The present study introduces a method for precise relative orbit determination based on a reduced-dynamic batch processing of differential GPS pseudorange and carrier phase measurements, which includes maneuver estimation as part of the relative orbit adjustment. The proposed method has been validated using flight data from space missions with different rates of maneuvering activity, including the GRACE, TanDEM-X and PRISMA missions. The results show the feasibility of obtaining precise relative orbits without degradation in the vicinity of maneuvers as well as improved maneuver estimates that can be used for better maneuver planning in flight dynamics operations.
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Kim, Jae-Hong; Kim, Ki-Baek; Kim, Woong-Chul; Kim, Ji-Hwan; Kim, Hae-Young
2014-03-01
This study aimed to evaluate the accuracy and precision of polyurethane (PUT) dental arch models fabricated using a three-dimensional (3D) subtractive rapid prototyping (RP) method with an intraoral scanning technique by comparing linear measurements obtained from PUT models and conventional plaster models. Ten plaster models were duplicated using a selected standard master model and conventional impression, and 10 PUT models were duplicated using the 3D subtractive RP technique with an oral scanner. Six linear measurements were evaluated in terms of x, y, and z-axes using a non-contact white light scanner. Accuracy was assessed using mean differences between two measurements, and precision was examined using four quantitative methods and the Bland-Altman graphical method. Repeatability was evaluated in terms of intra-examiner variability, and reproducibility was assessed in terms of inter-examiner and inter-method variability. The mean difference between plaster models and PUT models ranged from 0.07 mm to 0.33 mm. Relative measurement errors ranged from 2.2% to 7.6% and intraclass correlation coefficients ranged from 0.93 to 0.96, when comparing plaster models and PUT models. The Bland-Altman plot showed good agreement. The accuracy and precision of PUT dental models for evaluating the performance of oral scanner and subtractive RP technology was acceptable. Because of the recent improvements in block material and computerized numeric control milling machines, the subtractive RP method may be a good choice for dental arch models.
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The economic case for precision medicine.
Gavan, Sean P; Thompson, Alexander J; Payne, Katherine
2018-01-01
Introduction : The advancement of precision medicine into routine clinical practice has been highlighted as an agenda for national and international health care policy. A principle barrier to this advancement is in meeting requirements of the payer or reimbursement agency for health care. This special report aims to explain the economic case for precision medicine, by accounting for the explicit objectives defined by decision-makers responsible for the allocation of limited health care resources. Areas covered : The framework of cost-effectiveness analysis, a method of economic evaluation, is used to describe how precision medicine can, in theory, exploit identifiable patient-level heterogeneity to improve population health outcomes and the relative cost-effectiveness of health care. Four case studies are used to illustrate potential challenges when demonstrating the economic case for a precision medicine in practice. Expert commentary : The economic case for a precision medicine should be considered at an early stage during its research and development phase. Clinical and economic evidence can be generated iteratively and should be in alignment with the objectives and requirements of decision-makers. Programmes of further research, to demonstrate the economic case of a precision medicine, can be prioritized by the extent that they reduce the uncertainty expressed by decision-makers.
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Non-coding RNA detection methods combined to improve usability, reproducibility and precision
Directory of Open Access Journals (Sweden)
Kreikemeyer Bernd
2010-09-01
Full Text Available Abstract Background Non-coding RNAs gain more attention as their diverse roles in many cellular processes are discovered. At the same time, the need for efficient computational prediction of ncRNAs increases with the pace of sequencing technology. Existing tools are based on various approaches and techniques, but none of them provides a reliable ncRNA detector yet. Consequently, a natural approach is to combine existing tools. Due to a lack of standard input and output formats combination and comparison of existing tools is difficult. Also, for genomic scans they often need to be incorporated in detection workflows using custom scripts, which decreases transparency and reproducibility. Results We developed a Java-based framework to integrate existing tools and methods for ncRNA detection. This framework enables users to construct transparent detection workflows and to combine and compare different methods efficiently. We demonstrate the effectiveness of combining detection methods in case studies with the small genomes of Escherichia coli, Listeria monocytogenes and Streptococcus pyogenes. With the combined method, we gained 10% to 20% precision for sensitivities from 30% to 80%. Further, we investigated Streptococcus pyogenes for novel ncRNAs. Using multiple methods--integrated by our framework--we determined four highly probable candidates. We verified all four candidates experimentally using RT-PCR. Conclusions We have created an extensible framework for practical, transparent and reproducible combination and comparison of ncRNA detection methods. We have proven the effectiveness of this approach in tests and by guiding experiments to find new ncRNAs. The software is freely available under the GNU General Public License (GPL, version 3 at http://www.sbi.uni-rostock.de/moses along with source code, screen shots, examples and tutorial material.
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International Nuclear Information System (INIS)
Susanna TS; Samin
2007-01-01
Method performance (validation) of total mercury (Hg) testing in the biological samples by using cold vapour atomic absorption spectrophotometer (CV-AAS) has been done. The objective of this research is to know the method performance of CV-AAS as one of points for the accreditation testing of laboratory according IS0/IEC 17025-2005. The method performance covering limit of detection (LOD), accuracy, precision and bias. As a standard material used SRM Oyster Tissue 15660 from Winopal Forshung Germany, whereas the biological samples were human hair. In principle of mercury testing for solid samples using CV-AAS is dissolving this sample and standard with 10 mL HNO 3 supra pure into a closed quartz tube and heating at 150 °C for 4 hours. The concentration of mercury in each samples was determined at the condition of operation were stirring time (T 1 ) 70 seconds, delay time (T 2 ) 15 seconds, heating time (T 3 ) 13 seconds and cooling time (T 4 ) of 25 seconds. Mercury ion in samples are reduced with SnCl 2 10 % in H 2 SO 4 20 %, and then the vapour of mercury from reduction is passed in NaOH 20 % solution and aquatridest. The result of method performance were: limit of detection (LOD) = 0.085 ng, accuracy 99.70 %, precision (RSD) = 1.64 % and bias = 0.30 %. From the validation result showed that the content of mercury total was in the range of certified values. The total mercury content (Hg) in human hair were varied from 406.93 - 699.07 ppb. (author)
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Precision Oncology: Between Vaguely Right and Precisely Wrong.
Brock, Amy; Huang, Sui
2017-12-01
Precision Oncology seeks to identify and target the mutation that drives a tumor. Despite its straightforward rationale, concerns about its effectiveness are mounting. What is the biological explanation for the "imprecision?" First, Precision Oncology relies on indiscriminate sequencing of genomes in biopsies that barely represent the heterogeneous mix of tumor cells. Second, findings that defy the orthodoxy of oncogenic "driver mutations" are now accumulating: the ubiquitous presence of oncogenic mutations in silent premalignancies or the dynamic switching without mutations between various cell phenotypes that promote progression. Most troublesome is the observation that cancer cells that survive treatment still will have suffered cytotoxic stress and thereby enter a stem cell-like state, the seeds for recurrence. The benefit of "precision targeting" of mutations is inherently limited by this counterproductive effect. These findings confirm that there is no precise linear causal relationship between tumor genotype and phenotype, a reminder of logician Carveth Read's caution that being vaguely right may be preferable to being precisely wrong. An open-minded embrace of the latest inconvenient findings indicating nongenetic and "imprecise" phenotype dynamics of tumors as summarized in this review will be paramount if Precision Oncology is ultimately to lead to clinical benefits. Cancer Res; 77(23); 6473-9. ©2017 AACR . ©2017 American Association for Cancer Research.
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Precision siting of a particle accelerator
International Nuclear Information System (INIS)
Cintra, Jorge Pimentel
1996-01-01
Precise location is a specific survey job that involves a high skilled work to avoid unrecoverable results at the project installation. As a function of the different process stages, different specifications can be applied, invoking different instruments: theodolite, measurement tape, distanciometer, invar wire. This paper, based on experience obtained at the installation of particle accelerator equipment, deals with general principles of precise location: tolerance definitions, increasing accuracy techniques, schedule of locations, sensitivity analysis, quality control methods. (author)
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Ozbek, Nil; Akman, Suleyman
2012-05-30
Fluorine was determined via the rotational molecular absorption line of aluminum mono fluoride (AlF) generated in C(2)H(2)/N(2)O flame at 227.4613 nm using a high-resolution continuum source flame atomic absorption spectrophotometer (HR-CS-FAAS). The effects of AlF wavelength, burner height, fuel rate (C(2)H(2)/N(2)O) and amount of Al on the accuracy, precision and sensitivity were investigated and optimized. The Al-F absorption band at 227.4613 nm was found to be the most suitable analytical line with respect to sensitivity and spectral interferences. Maximum sensitivity and a good linearity were obtained in acetylene-nitrous oxide flame at a flow rate of 210 L h(-1) and a burner height of 8mm using 3000 mg L(-1) of Al for 10-1000 mg L(-1)of F. The accuracy and precision of the method were tested by analyzing spiked samples and waste water certified reference material. The results were in good agreement with the certified and spiked amounts as well as the precision of several days during this study was satisfactory (RSD<10%). The limit of detection and characteristic concentration of the method were 5.5 mg L(-1) and 72.8 mg L(-1), respectively. Finally, the fluorine concentrations in several toothpaste samples were determined. The results found and given by the producers were not significantly different. The method was simple, fast, accurate and sensitive. Copyright © 2012 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Hendra Gunawan
2014-06-01
Full Text Available http://dx.doi.org/10.17014/ijog.vol3no3.20084The precision of topographic density (Bouguer density estimation by the Nettleton approach is based on a minimum correlation of Bouguer gravity anomaly and topography. The other method, the Parasnis approach, is based on a minimum correlation of Bouguer gravity anomaly and Bouguer correction. The precision of Bouguer density estimates was investigated by both methods on simple 2D syntetic models and under an assumption free-air anomaly consisting of an effect of topography, an effect of intracrustal, and an isostatic compensation. Based on simulation results, Bouguer density estimates were then investigated for a gravity survey of 2005 on La Soufriere Volcano-Guadeloupe area (Antilles Islands. The Bouguer density based on the Parasnis approach is 2.71 g/cm3 for the whole area, except the edifice area where average topography density estimates are 2.21 g/cm3 where Bouguer density estimates from previous gravity survey of 1975 are 2.67 g/cm3. The Bouguer density in La Soufriere Volcano was uncertainly estimated to be 0.1 g/cm3. For the studied area, the density deduced from refraction seismic data is coherent with the recent Bouguer density estimates. New Bouguer anomaly map based on these Bouguer density values allows to a better geological intepretation.
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In-use stability of enrofloxacin solution for injection in multi-dose containers
Directory of Open Access Journals (Sweden)
Šandor Ksenija
2012-01-01
Full Text Available The in-use stability study in this paper was designed as far as possible to simulate the practical usage of multi-dose containers products in veterinary practice and to establish the influence of storage conditions on drug's quality. According to literature data, shelf-live of enrofloxacin solutions for injection tested in this study is 28 days after opening. In-use (open container stability testing of enrofloxacin injection solutions was studied during a period of 112 days, and the physical-chemical parameters and microbiological contamination were assessed. A spectrophotometric method was validated for the quantification of enrofloxacin. The validation method yielded good results and included the selectivity, linearity, intra-assay precision (1.26% RSD, inter-assay precision (1.52% RSD, limit of detection (0.18 μg/mL, limit of quantification (0.54 μg/mL and accuracy. The results of spectrophotometric analyses were presented as the mean drug concentration of enrofloxacin vs. time of sampling. The findings of physical, chemical and microbiological parameters were in accordance with the producers' specifications and no extreme changes during prescribed storage occurred. The study was extended from the drug's proposed shelf-life after opening for the next 84 days and in that period no significant changes were recorded.
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[Precision Nursing: Individual-Based Knowledge Translation].
Chiang, Li-Chi; Yeh, Mei-Ling; Su, Sui-Lung
2016-12-01
U.S. President Obama announced a new era of precision medicine in the Precision Medicine Initiative (PMI). This initiative aims to accelerate the progress of personalized medicine in light of individual requirements for prevention and treatment in order to improve the state of individual and public health. The recent and dramatic development of large-scale biologic databases (such as the human genome sequence), powerful methods for characterizing patients (such as genomics, microbiome, diverse biomarkers, and even pharmacogenomics), and computational tools for analyzing big data are maximizing the potential benefits of precision medicine. Nursing science should follow and keep pace with this trend in order to develop empirical knowledge and expertise in the area of personalized nursing care. Nursing scientists must encourage, examine, and put into practice innovative research on precision nursing in order to provide evidence-based guidance to clinical practice. The applications in personalized precision nursing care include: explanations of personalized information such as the results of genetic testing; patient advocacy and support; anticipation of results and treatment; ongoing chronic monitoring; and support for shared decision-making throughout the disease trajectory. Further, attention must focus on the family and the ethical implications of taking a personalized approach to care. Nurses will need to embrace the paradigm shift to precision nursing and work collaboratively across disciplines to provide the optimal personalized care to patients. If realized, the full potential of precision nursing will provide the best chance for good health for all.
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Directory of Open Access Journals (Sweden)
Marcos Vinícius de Moura Ribeiro
Full Text Available ABSTRACT Folic acid is a B complex water-soluble vitamin that is essential to humans, and its deficiency can cause problems including congenital malformations in the fetus as well as heart disease. Most countries affected by diseases associated with a lack of folic acid now supplement foods with the vitamin. There is therefore a need for the development of new analytical procedures able to determine folic acid present in different matrices. This work describes the development of zero order and first order derivative spectrophotometric methods for the determination of folic acid in different pharmaceutical formulations, using 0.1 mol L-1 NaOH as solvent. The methods are shown to be simple, selective, and robust. Good linearity was achieved, with correction coefficients ≥0.9996 and limits of detection and quantification ranging from 0.64 to 0.75 and from 1.80 to 2.85 mg L-1, respectively. Recoveries of 98-104% were obtained in accuracy tests, and precision (as RSD was between 0.2 and 4.8%. The methods can be used in routine analyses for quality control purposes, offering an alternative to the procedures already reported in the literature.
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Directory of Open Access Journals (Sweden)
Shipra Singh
2012-01-01
Full Text Available The present study was undertaken to develop a validated, rapid, simple, and low-cost ultraviolet (UV spectrophotometric method for estimating Etoricoxib (ETX in pharmaceutical formulations. The analysis was performed on λ max 233 nm using 0.1 M HCl as blank/diluent. The proposed method was validated on International Conference on Harmonization (ICH guidelines including parameters as linearity, accuracy, precision, reproducibility, and specificity. The proposed method was also used to access the content of the ETX in two commercial brands of Indian market. Beer′s law was obeyed in concentration range of 0.1-0.5 μg/ml, and the regression equation was Y = 0.418x + 0.018. The mean accuracy values for 0.1 μg/ml and 0.2 μg/ml concentration of ETX were found to be 99.76 ± 0.52% and 99.12 ± 0.84, respectively, and relative standard deviation (RSD of interday and intraday was less than 2%. The developed method was suitable and specific to the analysis of ETX even in the presence of common excipients. The method was applied on two different marketed brands and ETX contents were 98.5 ± 0.56 and 99.33 ± 0.44, respectively, of labeled claim. The proposed method was validated as per ICH guidelines and statistically good results were obtained. This method can be employed for routine analysis of ETX in bulk and commercial formulations.
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Directory of Open Access Journals (Sweden)
S Singh
2012-01-01
Full Text Available The present study was undertaken to develop a validated, rapid, simple, and low-cost ultraviolet (UV spectrophotometric method for estimating Etoricoxib (ETX in pharmaceutical formulations. The analysis was performed on Î max 233 nm using 0.1 M HCl as blank/diluent. The proposed method was validated on International Conference on Harmonization (ICH guidelines including parameters as linearity, accuracy, precision, reproducibility, and specificity. The proposed method was also used to access the content of the ETX in two commercial brands of Indian market. Beer′s law was obeyed in concentration range of 0.1-0.5 μg/ml, and the regression equation was Y = 0.418x + 0.018. The mean accuracy values for 0.1 μg/ml and 0.2 μg/ml concentration of ETX were found to be 99.76 ± 0.52% and 99.12 ± 0.84, respectively, and relative standard deviation (RSD of interday and intraday was less than 2%. The developed method was suitable and specific to the analysis of ETX even in the presence of common excipients. The method was applied on two different marketed brands and ETX contents were 98.5 ± 0.56 and 99.33 ± 0.44, respectively, of labeled claim. The proposed method was validated as per ICH guidelines and statistically good results were obtained. This method can be employed for routine analysis of ETX in bulk and commercial formulations.
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Li, Kai; Zhou, Xuhua; Guo, Nannan; Zhao, Gang; Xu, Kexin; Lei, Weiwei
2017-09-01
Zero-difference kinematic, dynamic and reduced-dynamic precise orbit determination (POD) are three methods to obtain the precise orbits of Low Earth Orbit satellites (LEOs) by using the on-board GPS observations. Comparing the differences between those methods have great significance to establish the mathematical model and is usefull for us to select a suitable method to determine the orbit of the satellite. Based on the zero-difference GPS carrier-phase measurements, Shanghai Astronomical Observatory (SHAO) has improved the early version of SHORDE and then developed it as an integrated software system, which can perform the POD of LEOs by using the above three methods. In order to introduce the function of the software, we take the Gravity Recovery And Climate Experiment (GRACE) on-board GPS observations in January 2008 as example, then we compute the corresponding orbits of GRACE by using the SHORDE software. In order to evaluate the accuracy, we compare the orbits with the precise orbits provided by Jet Propulsion Laboratory (JPL). The results show that: (1) If we use the dynamic POD method, and the force models are used to represent the non-conservative forces, the average accuracy of the GRACE orbit is 2.40cm, 3.91cm, 2.34cm and 5.17cm in radial (R), along-track (T), cross-track (N) and 3D directions respectively; If we use the accelerometer observation instead of non-conservative perturbation model, the average accuracy of the orbit is 1.82cm, 2.51cm, 3.48cm and 4.68cm in R, T, N and 3D directions respectively. The result shows that if we use accelerometer observation instead of the non-conservative perturbation model, the accuracy of orbit is better. (2) When we use the reduced-dynamic POD method to get the orbits, the average accuracy of the orbit is 0.80cm, 1.36cm, 2.38cm and 2.87cm in R, T, N and 3D directions respectively. This method is carried out by setting up the pseudo-stochastic pulses to absorb the errors of atmospheric drag and other
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International Nuclear Information System (INIS)
Kimoto, Natsumi; Hayashi, Hiroaki; Asahara, Takashi; Mihara, Yoshiki; Kanazawa, Yuki; Yamakawa, Tsutomu; Yamamoto, Shuichiro; Yamasaki, Masashi; Okada, Masahiro
2017-01-01
The aim of our study is to develop a novel material identification method based on a photon counting technique, in which the incident and penetrating X-ray spectra are analyzed. Dividing a 40 kV X-ray spectra into two energy regions, the corresponding linear attenuation coefficients are derived. We can identify the materials precisely using the relationship between atomic number and linear attenuation coefficient through the correction of the beam hardening effect of the X-ray spectra. - Highlights: • We propose a precise material identification method to be used as a photon counting system. • Beam hardening correction is important, even when the analysis is applied to the short energy regions in the X-ray spectrum. • Experiments using a single probe-type CdTe detector were performed, and Monte Carlo simulation was also carried out. • We described the applicability of our method for clinical diagnostic X-ray imaging in the near future.
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Directory of Open Access Journals (Sweden)
Stolarczyk Mariusz
2017-12-01
Full Text Available Applicability of derivative spectrophotometry for the determination of valsartan in the presence of a substance from the group of statins was checked. The obtained results indicate that the proposed method may be effective by using appropriate derivatives: for valsartan and fluvastatin - D1, D2 and D3, for valsartan and pravastatin - D1 and D3, for valsartan and atorvastatin - D2 and D3. The method was characterized by high sensitivity and accuracy. Linearity was maintained in the following ranges: 9.28-32.48 mg mL-1 for valsartan, 8.16-28.56 mg mL-1 f or fluvastatin, 14.40-39.90 mg mL-1 for atorvastatin and 9.60-48.00 mg mL-1 for pravastatin. Determination coefficients were in the range of 0.989-0.999 depending on the analyte and the order of derivative. The precision of the method was high with RSD from 0.1 to 2.5 % and recovery of individual components was within the range of 100 ± 5 %. The developed method was successfully applied to the determination of valsartan combined with fluvastatin, atorvastatin and pravastatin in laboratory prepared mixtures and in pharmaceutical preparations.
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Directory of Open Access Journals (Sweden)
Nieves Carro
2017-03-01
Full Text Available This paper reports the development and optimization of micro-matrix solid-phase dispersion (micro-MSPD of nine polychlorinated biphenyls (PCBs in mussel samples (Mytilus galloprovincialis by using a two-level factorial design. Four variables (amount of sample, anhydrous sodium sulphate, Florisil and solvent volume were considered as factors in the optimization process. The results suggested that only the interaction between the amount of anhydrous sodium sulphate and the solvent volume was statistically significant for the overall recovery of a trichlorinated compound, CB 28. Generally most of the considered species exhibited a similar behaviour, the sample and Florisil amounts had a positive effect on PCBs extractions and solvent volume and sulphate amount had a negative effect. The analytical determination and confirmation of PCBs were carried out by using GC-ECD and GC-MS/MS, respectively. The method was validated having satisfactory precision and accuracy with RSD values below 6% and recoveries between 81 and 116% for all congeners. The optimized method was applied to the extraction of real mussel samples from two Galician Rías.
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Directory of Open Access Journals (Sweden)
Fernando Henrique Andrade Nogueira
2013-12-01
Full Text Available The present study developed and validated an HPLC method for the simultaneous determination of artesunate (AS and mefloquine hydrochloride (MQ in fixed-dose combination tablets, according to ICH guidelines. The chromatographic separation was carried out on an XBridge C18 (250 x 4.6 mm i.d., 5 µm particle size, Waters analytical column. The mobile phase included a 0.05 M monobasic potassium phosphate buffer (pH adjusted to 3.0 with phosphoric acid and acetonitrile (50 + 50, v/v. The flow rate was 1.0 mL/min, and the run time was 13 minutes. A dual-wavelength approach was employed: AS detection was performed at 210 nm and MQ was detected at 283 nm, using a diode array detector. Stability of sample solutions was evaluated for 8 hours after preparation, during which time the solutions remained stable. Youden's test was employed to evaluate robustness. The method proved to be linear (r²>0.99, precise (RSD<2.0%, accurate, selective, and robust, proving to be appropriate for routine drug quality control analysis.
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Directory of Open Access Journals (Sweden)
Alexie M. F. Heimburger
2017-06-01
Full Text Available To effectively address climate change, aggressive mitigation policies need to be implemented to reduce greenhouse gas emissions. Anthropogenic carbon emissions are mostly generated from urban environments, where human activities are spatially concentrated. Improvements in uncertainty determinations and precision of measurement techniques are critical to permit accurate and precise tracking of emissions changes relative to the reduction targets. As part of the INFLUX project, we quantified carbon dioxide (CO2, carbon monoxide (CO and methane (CH4 emission rates for the city of Indianapolis by averaging results from nine aircraft-based mass balance experiments performed in November-December 2014. Our goal was to assess the achievable precision of the aircraft-based mass balance method through averaging, assuming constant CO2, CH4 and CO emissions during a three-week field campaign in late fall. The averaging method leads to an emission rate of 14,600 mol/s for CO2, assumed to be largely fossil-derived for this period of the year, and 108 mol/s for CO. The relative standard error of the mean is 17% and 16%, for CO2 and CO, respectively, at the 95% confidence level (CL, i.e. a more than 2-fold improvement from the previous estimate of ~40% for single-flight measurements for Indianapolis. For CH4, the averaged emission rate is 67 mol/s, while the standard error of the mean at 95% CL is large, i.e. ±60%. Given the results for CO2 and CO for the same flight data, we conclude that this much larger scatter in the observed CH4 emission rate is most likely due to variability of CH4 emissions, suggesting that the assumption of constant daily emissions is not correct for CH4 sources. This work shows that repeated measurements using aircraft-based mass balance methods can yield sufficient precision of the mean to inform emissions reduction efforts by detecting changes over time in urban emissions.
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Omar, Mei Musa Ali; Elbashir, Abdalla Ahmed; Schmitz, Oliver J
2017-01-01
Simple and inexpensive capillary electrophoresis with UV-detection method (CE-UV) was optimized and validated for determination of six amino acids namely (alanine, asparagine, glutamine, proline, serine and valine) for Sudanese food. Amino acids in the samples were derivatized with 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) prior to CE-UV analysis. Labeling reaction conditions (100mM borate buffer at pH 8.5, labeling reaction time 60min, temperature 70°C and NBD-Cl concentration 40mM) were systematically investigated. The optimal conditions for the separation were 100mM borate buffer at pH 9.7 and detected at 475nm. The method was validated in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), precision (repeatability) (RSD%) and accuracy (recovery). Good linearity was achieved for all amino acids (r(2)>0.9981) in the concentration range of 2.5-40mg/L. The LODs in the range of 0.32-0.56mg/L were obtained. Recoveries of amino acids ranging from 85% to 108%, (n=3) were obtained. The validated method was successfully applied for the determination of amino acids for Sudanese food samples. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Xusheng Ge
2016-07-01
Full Text Available An effective sample preparation procedure using an accelerated solvent extraction (ASE procedure, followed by cleaning with melamine molecularly imprinted polymers solid-phase extraction (MISPE was developed. A novel and highly sensitive ASE–MISPE–ultra-performance liquid chromatography (UPLC method was developed for effective separation and simultaneous determination of dicyandiamide (DCD, cyromazine (CYR, and melamine (MEL in complex animal tissue foods. Under optimized conditions, good linearity was achieved with a correlation coefficient (r of 0.9999 in the range of at least two orders of magnitude. The limit of quantification of the method was 1.7 μg/kg, 5.0 μg/kg, and 3.2 μg/kg for DCD, MEL, and CYR, which was three orders of magnitude smaller than the maximum residue limits (MRLs. The intra- and inter-day precisions (in terms of the relative standard deviation, RSD of the three analytes were in the range of 1.7–3.1% and 3.1–6.3%, respectively. The average recoveries of analytes from blank chicken, beef, mutton, pork, and pig liver samples spiked with the three levels varied from 91.2% to 107% with RSD of 1.7–8.3% for DCD, 89.0–104% with RSD of 2.1–6.1% for CYR, and 94.8–105% with RSD of 1.1–6.6% for MEL. The proposed method has the characteristics of speed, sensitivity, and accuracy, and can be used for the routine determination of DCD, CYR, and MEL at the μg/kg level in complex animal tissue foods.
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Directory of Open Access Journals (Sweden)
J. Mehta
2010-01-01
Full Text Available A simple and precise reversed phase high performance liquid chromatographic method has been developed and validated for the quantification of benzalkonium chloride (BKC preservative in pharmaceutical formulation of latanoprost eye drops. The analyte was chromatographed on a Waters Spherisorb CN, (4.6×250 mm column packed with particles of 5 μm. The mobile phase, optimized through an experimental design, was a 40:60 (v/v mixture of potassium dihydrogen orthophosphate buffer (pH 5.5 and acetonitrile, pumped at a flow rate of 1.0 mL/min at maintaining column temperature at 30 °C. Maximum UV detection was achieved at 210 nm. The method was validated in terms of linearity, repeatability, intermediate precision and method accuracy. The method was shown to be robust, resisting to small deliberate changes in pH, flow rate and composition (organic ratio of the mobile phase. The method was successfully applied for the determination of BKC in a pharmaceutical formulation of latanoprost ophthalmic solution without any interference from common excipients and drug substance. All the validation parameters were within the acceptance range, concordant to ICH guidelines.
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Directory of Open Access Journals (Sweden)
S. G. Tian
2013-01-01
Full Text Available A high-performance thin-layer chromatographic (HPTLC method has been established for simultaneous analysis of rosmarinic acid and rutin in Abnormal Savda Munziq (ASMq. A methanol extract of ASMq was used for quantification. The compounds were separated on silica gel H thin layer plate with ethyl acetate-formic acid-acetic acid-water 15 : 1 : 1 : 1.5 (v/v as a developer, trichloroethanol as the color reagent. The plates were scanned at 365 nm. The linear calibration data of rosmarinic acid and rutin were in the range of 0.0508 to 0.2540 μg (r=0.9964, 0.2707 to 1.35354 μg (r=0.9981, respectively. The recovery rate of rosmarinic acid was 99.17% (RSD = 2.92% and rutin was 95.24% (RSD = 2.38%. The method enables rapid screening, precise, selective, and sensitive quantification for pharmaceutical analysis.
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Energy Technology Data Exchange (ETDEWEB)
Houtermans, H.; Schaerf, K.; Reichel, F. (International Atomic Energy Agency, Vienna (Austria)); Debertin, K. (Physikalisch-Technische Bundesanstalt, Braunschweig (Germany, F.R.))
1983-02-01
The International Atomic Energy Agency organized an international comparison of methods applied in high-precision ..gamma..-ray spectrometry for the correction of dead-time and pile-up losses. Results of this comparison are reported and discussed.
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High-precision solution to the moving load problem using an improved spectral element method
Wen, Shu-Rui; Wu, Zhi-Jing; Lu, Nian-Li
2018-02-01
In this paper, the spectral element method (SEM) is improved to solve the moving load problem. In this method, a structure with uniform geometry and material properties is considered as a spectral element, which means that the element number and the degree of freedom can be reduced significantly. Based on the variational method and the Laplace transform theory, the spectral stiffness matrix and the equivalent nodal force of the beam-column element are established. The static Green function is employed to deduce the improved function. The proposed method is applied to two typical engineering practices—the one-span bridge and the horizontal jib of the tower crane. The results have revealed the following. First, the new method can yield extremely high-precision results of the dynamic deflection, the bending moment and the shear force in the moving load problem. In most cases, the relative errors are smaller than 1%. Second, by comparing with the finite element method, one can obtain the highly accurate results using the improved SEM with smaller element numbers. Moreover, the method can be widely used for statically determinate as well as statically indeterminate structures. Third, the dynamic deflection of the twin-lift jib decreases with the increase in the moving load speed, whereas the curvature of the deflection increases. Finally, the dynamic deflection, the bending moment and the shear force of the jib will all increase as the magnitude of the moving load increases.
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Directory of Open Access Journals (Sweden)
Harshal K. Trivedi
2010-01-01
Full Text Available A simple, precise, shorter runtime and stability indicating reverse-phase high performance liquid chromatographic method has been developed and validated for the quantification of benzalkonium chloride (BKC preservative in pharmaceutical formulation of sparfloxacin eye drop. The method was successfully applied for determination of benzalkonium chloride in various ophthalmic formulations like latanoprost, timolol, dexametasone, gatifloxacin, norfloxacin, combination of moxifloxacin and dexamethasone, combination of nepthazoline HCl, zinc sulphate and chlorpheniramine maleate, combination of tobaramycin and dexamethasone, combination of phenylephrine HCl, naphazoline HCl, menthol and camphor. The RP-LC separation was achieved on an Purospher Star RP-18e 75 mm × 4.0 mm, 3.0 μ in the isocratic mode using buffer: acetonitrile (35: 65, v/v, as the mobile phase at a flow rate of 1.8 mL/min. The methods were performed at 215 nm; in LC method, quantification was achieved with PDA detection over the concentration range of 50 to 150 μg/mL. The method is effective to separate four homologs with good resolution in presence of excipients, sparfloxacin and degradable compound due to sparfloxacin and BKC within five minutes. The method was validated and the results were compared statistically. They were found to be simple, accurate, precise and specific. The proposed method was validated in terms of specificity, precision, recovery, solution stability, linearity and range. All the validation parameters were within the acceptance range and concordant to ICH guidelines.
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Brill, Katherine; Marmontel, Miriam; Bolen-Richardson, Meghan; Stewart, Robert EA
2016-01-01
Manatees are routinely aged by counting Growth Layer Groups (GLGs) in periotic bones (earbones). Manatee carcasses recovered in Florida between 1974 and 2010 provided age-estimation material for three readers and formed the base for a retrospective analysis of aging precision (repeatability). All readers were in good agreement (high precision) with the greatest apparent source of variation being the result of earbone remodelling with increasing manatee age. Over the same period, methods of sa...
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Liu, Jen-Pei; Lu, Li-Tien; Liao, C T
2009-09-01
Intermediate precision is one of the most important characteristics for evaluation of precision in assay validation. The current methods for evaluation of within-device precision recommended by the Clinical Laboratory Standard Institute (CLSI) guideline EP5-A2 are based on the point estimator. On the other hand, in addition to point estimators, confidence intervals can provide a range for the within-device precision with a probability statement. Therefore, we suggest a confidence interval approach for assessment of the within-device precision. Furthermore, under the two-stage nested random-effects model recommended by the approved CLSI guideline EP5-A2, in addition to the current Satterthwaite's approximation and the modified large sample (MLS) methods, we apply the technique of generalized pivotal quantities (GPQ) to derive the confidence interval for the within-device precision. The data from the approved CLSI guideline EP5-A2 illustrate the applications of the confidence interval approach and comparison of results between the three methods. Results of a simulation study on the coverage probability and expected length of the three methods are reported. The proposed method of the GPQ-based confidence intervals is also extended to consider the between-laboratories variation for precision assessment.
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Sensitive method for precise measurement of endogenous angiotensins I, II and III in human plasma
International Nuclear Information System (INIS)
Kawamura, M.; Yoshida, K.; Akabane, S.
1987-01-01
We measured endogenous angiotensins (ANGs) I, IIandIII using a system of extraction by Sep-Pak column followed by high performance liquid chromatography (HPLC) combined with radioimmunoassay (RIA). An excellent separation of ANGs was obtained by HPLC. The recovery of ANGs I, IIandIII was 80-84%, when these authentic peptides were added to 6 ml of plasma. The coefficient of variation of the ANGs was 0.04-0.09 for intra-assay and 0.08-0.13 for inter-assay, thereby indicating a good reproducibility. Plasma ANGs I, IIandIII measured by this method in 5 normal volunteers were 51,4.5 and 1.2 pg/ml. In the presence of captopril, ANGs IIandIII decreased by 84% and 77%, respectively, while ANG I increased 5.1 times. This method is therefore useful to assess the precise levels of plasma ANGs
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Scare, J A; Slusarewicz, P; Noel, M L; Wielgus, K M; Nielsen, M K
2017-11-30
Fecal egg counts are emphasized for guiding equine helminth parasite control regimens due to the rise of anthelmintic resistance. This, however, poses further challenges, since egg counting results are prone to issues such as operator dependency, method variability, equipment requirements, and time commitment. The use of image analysis software for performing fecal egg counts is promoted in recent studies to reduce the operator dependency associated with manual counts. In an attempt to remove operator dependency associated with current methods, we developed a diagnostic system that utilizes a smartphone and employs image analysis to generate automated egg counts. The aims of this study were (1) to determine precision of the first smartphone prototype, the modified McMaster and ImageJ; (2) to determine precision, accuracy, sensitivity, and specificity of the second smartphone prototype, the modified McMaster, and Mini-FLOTAC techniques. Repeated counts on fecal samples naturally infected with equine strongyle eggs were performed using each technique to evaluate precision. Triplicate counts on 36 egg count negative samples and 36 samples spiked with strongyle eggs at 5, 50, 500, and 1000 eggs per gram were performed using a second smartphone system prototype, Mini-FLOTAC, and McMaster to determine technique accuracy. Precision across the techniques was evaluated using the coefficient of variation. In regards to the first aim of the study, the McMaster technique performed with significantly less variance than the first smartphone prototype and ImageJ (psmartphone and ImageJ performed with equal variance. In regards to the second aim of the study, the second smartphone system prototype had significantly better precision than the McMaster (psmartphone system were 64.51%, 21.67%, and 32.53%, respectively. The Mini-FLOTAC was significantly more accurate than the McMaster (psmartphone system (psmartphone and McMaster counts did not have statistically different accuracies
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International Nuclear Information System (INIS)
Conway, Tim M.; Rosenberg, Angela D.; Adkins, Jess F.; John, Seth G.
2013-01-01
Graphical abstract: ‘Metal-free’ seawater doped with varying concentrations of ‘zero’ isotope standards, processed through our simultaneous method, and then analyzed by double spike MC-ICPMS for Fe, Zn and Cd isotope ratios. All values were determined within 2 σ error (error bars shown) of zero. -- Highlights: •The first simultaneous method for isotopic analysis of Fe, Zn and Cd in seawater. •Designed for 1 L samples, a 1–20 fold improvement over previous methods. •Low blanks and high precision allow measurement of low concentration samples. •Small volume and fast processing are ideal for high-resolution large-scale studies. •Will facilitate investigation of marine trace-metal isotope cycling. -- Abstract: The study of Fe, Zn and Cd stable isotopes (δ 56 Fe, δ 66 Zn and δ 114 Cd) in seawater is a new field, which promises to elucidate the marine cycling of these bioactive trace metals. However, the analytical challenges posed by the low concentration of these metals in seawater has meant that previous studies have typically required large sample volumes, highly limiting data collection in the oceans. Here, we present the first simultaneous method for the determination of these three isotope systems in seawater, using Nobias PA-1 chelating resin to extract metals from seawater, purification by anion exchange chromatography, and analysis by double spike MC-ICPMS. This method is designed for use on only a single litre of seawater and has blanks of 0.3, 0.06 and <0.03 ng for Fe, Zn and Cd respectively, representing a 1–20 fold reduction in sample size and a 4–130 decrease in blank compared to previously reported methods. The procedure yields data with high precision for all three elements (typically 0.02–0.2‰; 1σ internal precision), allowing us to distinguish natural variability in the oceans, which spans 1–3‰ for all three isotope systems. Simultaneous extraction and purification of three metals makes this method ideal for high
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Precision Learning Assessment: An Alternative to Traditional Assessment Techniques.
Caltagirone, Paul J.; Glover, Christopher E.
1985-01-01
A continuous and curriculum-based assessment method, Precision Learning Assessment (PLA), which integrates precision teaching and norm-referenced techniques, was applied to a math computation curriculum for 214 third graders. The resulting districtwide learning curves defining average annual progress through the computation curriculum provided…
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Big Data's Role in Precision Public Health.
Dolley, Shawn
2018-01-01
Precision public health is an emerging practice to more granularly predict and understand public health risks and customize treatments for more specific and homogeneous subpopulations, often using new data, technologies, and methods. Big data is one element that has consistently helped to achieve these goals, through its ability to deliver to practitioners a volume and variety of structured or unstructured data not previously possible. Big data has enabled more widespread and specific research and trials of stratifying and segmenting populations at risk for a variety of health problems. Examples of success using big data are surveyed in surveillance and signal detection, predicting future risk, targeted interventions, and understanding disease. Using novel big data or big data approaches has risks that remain to be resolved. The continued growth in volume and variety of available data, decreased costs of data capture, and emerging computational methods mean big data success will likely be a required pillar of precision public health into the future. This review article aims to identify the precision public health use cases where big data has added value, identify classes of value that big data may bring, and outline the risks inherent in using big data in precision public health efforts.
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Precision phase estimation based on weak-value amplification
Qiu, Xiaodong; Xie, Linguo; Liu, Xiong; Luo, Lan; Li, Zhaoxue; Zhang, Zhiyou; Du, Jinglei
2017-02-01
In this letter, we propose a precision method for phase estimation based on the weak-value amplification (WVA) technique using a monochromatic light source. The anomalous WVA significantly suppresses the technical noise with respect to the intensity difference signal induced by the phase delay when the post-selection procedure comes into play. The phase measured precision of this method is proportional to the weak-value of a polarization operator in the experimental range. Our results compete well with the wide spectrum light phase weak measurements and outperform the standard homodyne phase detection technique.
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Development of Precise Point Positioning Method Using Global Positioning System Measurements
Directory of Open Access Journals (Sweden)
Byung-Kyu Choi
2011-09-01
Full Text Available Precise point positioning (PPP is increasingly used in several parts such as monitoring of crustal movement and maintaining an international terrestrial reference frame using global positioning system (GPS measurements. An accuracy of PPP data processing has been increased due to the use of the more precise satellite orbit/clock products. In this study we developed PPP algorithm that utilizes data collected by a GPS receiver. The measurement error modelling including the tropospheric error and the tidal model in data processing was considered to improve the positioning accuracy. The extended Kalman filter has been also employed to estimate the state parameters such as positioning information and float ambiguities. For the verification, we compared our results to other of International GNSS Service analysis center. As a result, the mean errors of the estimated position on the East-West, North-South and Up-Down direction for the five days were 0.9 cm, 0.32 cm, and 1.14 cm in 95% confidence level.
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Institute of Scientific and Technical Information of China (English)
ZHOU Yuliang; LU Guihua; JIN Juliang; TONG Fang; ZHOU Ping
2006-01-01
Precise comprehensive evaluation of flood disaster loss is significant for the prevention and mitigation of flood disasters. Here, one of the difficulties involved is how to establish a model capable of describing the complex relation between the input and output data of the system of flood disaster loss. Genetic programming (GP) solves problems by using ideas from genetic algorithm and generates computer programs automatically. In this study a new method named the evaluation of the grade of flood disaster loss (EGFD) on the basis of improved genetic programming (IGP) is presented (IGPEGFD). The flood disaster area and the direct economic loss are taken as the evaluation indexes of flood disaster loss. Obviously that the larger the evaluation index value, the larger the corresponding value of the grade of flood disaster loss is. Consequently the IGP code is designed to make the value of the grade of flood disaster be an increasing function of the index value. The result of the application of the IGP-EGFD model to Henan Province shows that a good function expression can be obtained within a bigger searched function space; and the model is of high precision and considerable practical significance.Thus, IGP-EGFD can be widely used in automatic modeling and other evaluation systems.
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Directory of Open Access Journals (Sweden)
Dion Notario
2017-04-01
Full Text Available To conduct a bioequivalence study for a copy product of levofloxacin (LEV, a simple and validated analytical method was needed, but the previous developed methods were still too complicated. For this reason, a simple and rapid high performance liquid chromatography method was developed and validated for LEV quantification in human plasma. Chromatographic separation was performed under isocratic elution on a Luna Phenomenex® C18 (150 × 4.6 mm, 5 µm column. The mobile phase was comprised of acetonitrile, methanol, and phosphate buffer 25 mM that adjusted at pH 3.0 (13:7:80 v/v/v and pumped at a flow rate of 1.5 mL/min. Detection was performed under UV detector at wavelength of 280 nm. Samples were prepared by adding acetonitrile and followed by centrifugation to precipitate plasma protein. Then followed successively by evaporation and reconstitution step. The optimized method meets the requirements of validation parameters which included linearity (r = 0.995, sensitivity (LLOQ and LOD was 1.77 and 0.57 µg/mL respectively, accuracy (%error above LLOQ ≤ 12% and LLOQ ≤ 20%, precision (RSD ≤ 9%, and robustness in the ranges of 1.77-28.83 µg/mL. Therefore, the method can be used as a routine analysis of LEV in human plasma as well as in bioequivalence study of LEV.
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High precision detector robot arm system
Shu, Deming; Chu, Yong
2017-01-31
A method and high precision robot arm system are provided, for example, for X-ray nanodiffraction with an X-ray nanoprobe. The robot arm system includes duo-vertical-stages and a kinematic linkage system. A two-dimensional (2D) vertical plane ultra-precision robot arm supporting an X-ray detector provides positioning and manipulating of the X-ray detector. A vertical support for the 2D vertical plane robot arm includes spaced apart rails respectively engaging a first bearing structure and a second bearing structure carried by the 2D vertical plane robot arm.
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Makoś, Patrycja; Fernandes, Andre; Boczkaj, Grzegorz
2017-09-29
The paper presents a new method for the determination of 15 carboxylic acids in samples of postoxidative effluents from the production of petroleum bitumens using ion-pair dispersive liquid-liquid microextraction and gas chromatography coupled to mass spectrometry with injection port derivatization. Several parameters related to the extraction and derivatization efficiency were optimized. Under optimized experimental conditions, the obtained limit of detection and quantification ranged from 0.0069 to 1.12μg/mL and 0.014 to 2.24μg/mL, respectively. The precision (RSD ranged 1.29-6.42%) and recovery (69.43-125.79%) were satisfactory. Nine carboxylic acids at concentrations ranging from 0.10μg/mL to 15.06μg/mL were determined in the raw wastewater and in samples of effluents treated by various oxidation methods. The studies revealed a substantial increase of concentration of benzoic acids, in samples of wastewater after treatment, which confirms the need of carboxylic acids monitoring during industrial effluent treatment processes. Copyright © 2017 Elsevier B.V. All rights reserved.
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Daniele, Gaëlle; Lafay, Florent; Pelosi, Céline; Fritsch, Clémentine; Vulliet, Emmanuelle
2018-06-04
Agricultural intensification, and in particular the use of pesticides, leads over the years to a loss of biodiversity and a decline of ecosystem services in cultivated zones and agricultural landscapes. Among the animal communities involved in the functioning of agro-ecosystems, earthworms are ubiquitous and recognized as indicators of land uses and cultural practices. However, little data is available on the levels of pesticides in such organisms in natura, which would allow estimating their actual exposure and the potentially resulting impacts. Thus, the objective of this study was to develop a sensitive analytical methodology to detect and quantify 27 currently used pesticides in earthworms (Allolobophora chlorotica). A modified QuEChERS extraction was implemented on individual earthworms. This step was followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The whole analytical method was validated on spiked earthworm blank samples, with regard to linearity (from 1 to 100 method limit of quantification, r 2 > 0.95), intra-day precision (relative standard deviation (RSD) Graphical abstract.
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Measurement of HDO Products Using GC-TCD: Towards Obtaining Reliable Analytical Data
Directory of Open Access Journals (Sweden)
Zuas Oman
2018-03-01
Full Text Available This paper reported the method development and validation of a gas chromatography with thermal conductivity detector (GC-TCD method for the measurement of the gaseous products of hydrodeoxygenation (HDO. The method validation parameters include selectivity, precision (repeatability and reproducibility, accuracy, linearity, limit of detection (LoD, limit of quantitation (LoQ, and robustness. The results showed that the developed method was able to separate the target components (H2, CO2, CH4 and CO from their mixtures without any special sample treatment. The validated method was selective, precise, accurate, and robust. Application of the developed and validated GC-TCD method to the measurement of by-product components of HDO of bio-oil revealed a good performance with relative standard deviation (RSD less than 1.0% for all target components, implying that the process of method development and validation provides a trustworthy way of obtaining reliable analytical data.
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Yang, Zong-Lin; Li, Hui; Wang, Bing; Liu, Shu-Ying
2016-02-15
Neurotransmitters (NTs) and their metabolites are known to play an essential role in maintaining various physiological functions in nervous system. However, there are many difficulties in the detection of NTs together with their metabolites in biological samples. A new method for NTs and their metabolites detection by high performance liquid chromatography coupled with Q Exactive hybrid quadruple-orbitrap high-resolution accurate mass spectrometry (HPLC-HRMS) was established in this paper. This method was a great development of the applying of Q Exactive MS in the quantitative analysis. This method enabled a rapid quantification of ten compounds within 18min. Good linearity was obtained with a correlation coefficient above 0.99. The concentration range of the limit of detection (LOD) and the limit of quantitation (LOQ) level were 0.0008-0.05nmol/mL and 0.002-25.0nmol/mL respectively. Precisions (relative standard deviation, RSD) of this method were at 0.36-12.70%. Recovery ranges were between 81.83% and 118.04%. Concentrations of these compounds in mouse hypothalamus were detected by Q Exactive LC-MS technology with this method. Copyright © 2016 Elsevier B.V. All rights reserved.
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Lee, H. W.; Lim, H. W.; Jeon, D. H.; Park, C. K.; Cho, H. S.; Seo, C. W.; Lee, D. Y.; Kim, K. S.; Kim, G. A.; Park, S. Y.; Kang, S. Y.; Park, J. E.; Kim, W. S.; Woo, T. H.; Oh, J. E.
2018-06-01
This study investigated the effectiveness of a new method for measuring the actual focal spot position of a diagnostic x-ray tube using a high-precision antiscatter grid and a digital x-ray detector in which grid magnification, which is directly related to the focal spot position, was determined from the Fourier spectrum of the acquired x-ray grid’s image. A systematic experiment was performed to demonstrate the viability of the proposed measurement method. The hardware system used in the experiment consisted of an x-ray tube run at 50 kVp and 1 mA, a flat-panel detector with a pixel size of 49.5 µm, and a high-precision carbon-interspaced grid with a strip density of 200 lines/inch. The results indicated that the focal spot of the x-ray tube (Jupiter 5000, Oxford Instruments) used in the experiment was located approximately 31.10 mm inside from the exit flange, well agreed with the nominal value of 31.05 mm, which demonstrates the viability of the proposed measurement method. Thus, the proposed method can be utilized for system’s performance optimization in many x-ray imaging applications.
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Vichi, Stefania; Cortés-Francisco, Nuria; Caixach, Josep
2015-05-15
A simultaneous derivatization/extraction method followed by liquid chromatography-electrospray-high resolution mass spectrometry for the determination of volatile thiols in hydroalcoholic matrixes was optimized and used to identify and quantify volatile thiols in wine and beer samples. The method was evaluated in terms of sensitivity, precision, accuracy and selectivity. The experimental LOQs of eleven thiols tested ranged between 0.01 ng/L and 10 ng/L. Intra-day relative standard deviation (RSD) was in general lower than 10% and inter-day RSD ranged between 10% and 30%. Recovery in the model and real matrixes ranged from 45% to 129%. The method was then applied for the analysis of four white wines and six beers. Five out of the eleven reference thiols were identified and quantified in the samples analyzed. The non-target approach, carried out by monitoring the diagnostic ion at m/z 275.9922 [C13H10ONSe](+) in the fragmentation spectrum, allowed detecting, in the same samples, fourteen non-target thiols. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Katherine Brill
2016-06-01
Full Text Available Manatees are routinely aged by counting Growth Layer Groups (GLGs in periotic bones (earbones. Manatee carcasses recovered in Florida between 1974 and 2010 provided age-estimation material for three readers and formed the base for a retrospective analysis of aging precision (repeatability. All readers were in good agreement (high precision with the greatest apparent source of variation being the result of earbone remodelling with increasing manatee age. Over the same period, methods of sample preparation and of determining a final age estimate changed. We examined the effects of altering methods on ease of reading GLGs and found no statistical differences. Accurate age estimates are an important component for effective management of the species and for better models of population trends and we summarize the currently recommended methods for estimating manatee ages using earbones.
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Research on Ship Trajectory Tracking with High Precision Based on LOS
Directory of Open Access Journals (Sweden)
Hengzhi Liu
2018-01-01
Full Text Available Aiming at how precise to track by LOS, a method is proposed. The method combines the advantages of LOS simplicity and intuition, easy parameter setting and good convergence, with the features of GPC softening, multi-step prediction, rolling optimization and excellent controllability and robustness. In order to verify the effectiveness of the method, the method is simulated by Matlab. The simulation’s results show that it makes ship tracking highly precise.
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Laakso, Päivi H
2014-01-01
This collaborative study with nine participating laboratories was conducted to determine the total plant sterol and/or plant stanol contents in phytosterol fortified foods with a gas chromatographic method. Four practice and 12 test samples representing mainly commercially available foodstuffs were analyzed as known replicates. Twelve samples were enriched with phytosterols, whereas four samples contained only natural contents of phytosterols. The analytical procedure consisted of two alternative approaches: hot saponification method, and acid hydrolysis treatment prior to hot saponification. As a result, sterol/stanol compositions and contents in the samples were measured. The amounts of total plant sterols and total plant stanols varying from 0.005 to 8.04 g/100 g product were statistically evaluated after outliers were eliminated. The repeatability RSD (RSDr) varied from 1.34 to 17.13%. The reproducibility RSD (RSDR) ranged from 3.03 to 17.70%, with HorRat values ranging from 0.8 to 2.1. When only phytosterol enriched food test samples are considered, the RSDr ranged from 1.48 to 6.13%, the RSD, ranged from 3.03 to 7.74%, and HorRat values ranged from 0.8 to 2.1. Based on the results of this collaborative study, the study coordinator concludes the method is fit for its purpose.
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Mechanics and Physics of Precise Vacuum Mechanisms
Deulin, E. A; Panfilov, Yu V; Nevshupa, R. A
2010-01-01
In this book the Russian expertise in the field of the design of precise vacuum mechanics is summarized. A wide range of physical applications of mechanism design in electronic, optical-electronic, chemical, and aerospace industries is presented in a comprehensible way. Topics treated include the method of microparticles flow regulation and its determination in vacuum equipment and mechanisms of electronics; precise mechanisms of nanoscale precision based on magnetic and electric rheology; precise harmonic rotary and not-coaxial nut-screw linear motion vacuum feedthroughs with technical parameters considered the best in the world; elastically deformed vacuum motion feedthroughs without friction couples usage; the computer system of vacuum mechanisms failure predicting. This English edition incorporates a number of features which should improve its usefulness as a textbook without changing the basic organization or the general philosophy of presentation of the subject matter of the original Russian work. Exper...
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Directory of Open Access Journals (Sweden)
Urdigere Rangachar Anil Kumar
2008-04-01
Full Text Available Two simple, sensitive and rapid methods are described for the determination pantoprazole sodium sesqui hydrate (PNT in bulk drug and in formulations using N-bromosuccinimide (NBS as the oxidimetric reagent. The methods involve the addition of a known excess of NBS to PNT in HCl medium followed by estimation of the unreacted oxidant by two reaction schemes involving the use of iron(II and thiocyanate (method A or tiron (method B. In both methods, the absorbance is found to decrease linearly with PNT concentration. Beer’s law is obeyed over the ranges 0.25-3.5 and 1-15 µg mL-1 for method A and method B, respectively. The calculated molar absorptivity values are 1.4 × 105 and 2.5 × 104 L mol-1cm-1 for method A and method B, respectively. The limit of detection (LOD and quantification (LOQ are also reported for both methods. The RSD values for intra-day and inter-day precision studies were less than 2.5 and 3.0 %, respectively. Both the methods were applied to the determination of PNT in dosage forms and the results were satisfactory, and were comparable with those obtained by the reference method. The accuracy and reliability of the proposed methods were further ascertained by recoveries studies, and the recoveries of the spiked drug ranged between 98.5 and 102.5 %.
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Han, Meihua; Chen, Jing; Chen, Shilin; Wang, Xiangtao
2009-05-01
To establish a RP-HPLC method for content and entrapment efficiency of 20 (S)-protopanaxadiol in pharmacosomes. The separation was performed with a COSMOSIL 5 C18-MS-II column (4.6 mm x 250 mm, 5 mmicrom) using methanol-water (95:5) as the mobile phase and detected at 203 nm. The flow rate was 1.0 mL x min(-1) and 50 microL sample solution was injected for each time. The calibration curve was linear within the range 0.1-0.5 mg x mL(-1) (r = 0. 9999) , the intra-day RSD and inter-day RSD were less than 2% and the average recovery was between 101.44%-103.11% (n = 3). The method is simple, accurate, sensitive and applicable for determination of content and entrapment efficiency of 20 (S)-protopanaxadiol pharmacosomes.
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Tan, Zhirong; Ouyang, Dongsheng; Chen, Yao; Zhou, Gan; Cao, Shan; Wang, Yicheng; Peng, Xiujuan; Zhou, Honghao
2010-08-01
A sensitive and specific liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS/MS) method has been developed and validated for the identification and quantification of clebopride in human plasma using itopride as an internal standard. The method involves a simple liquid-liquid extraction. The analytes were separated by isocratic gradient elution on a CAPCELL MG-III C(18) (5 microm, 150 mm x 2.1 mm i.d.) column and analyzed in multiple reaction monitoring (MRM) mode with positive electrospray ionization (ESI) interface using the respective [M+H](+) ions, m/z 373.9-->m/z184.0 for clebopride, m/z 359.9-->m/z71.5 for itopride. The method was validated over the concentration range of 69.530-4450.0 pg/ml for clebopride. Within- and between-batch precision (RSD%) was all within 6.83% and accuracy ranged from -8.16 to 1.88%. The LLOQ was 69.530 pg/ml. The extraction recovery was on an average 77% for clebopride. The validated method was used to study the pharmacokinetics profile of clebopride in human plasma after oral administration of clebopride. Copyright 2010. Published by Elsevier B.V.
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International Nuclear Information System (INIS)
Qiao Yong; Shen Jingbang; Wu Yong; Wang Zexia
2014-01-01
Introduced two methods composed of AMT and high-precision ground magnetic survey were used to the exploration of granite uranium deposits in the Yin gongshan areas middle part of the Nei Monggol. Through experiment of methods and analysis of applicated results, think that AMT have good vertical resolution and could preferably survey thickness of rockmass, position of fracture and deep conditions, space distribution features of fracture zone ect, but it is not clear for rockmass, xenolith of reflection. And high-precision ground magnetic survey could delineate rockmass, xenolith of distribution range and identify the rock contact zone, fracture ect, but it generally measure position and it is not clear for occurrence, extension. That can resolve some geological structures by using the integrated methods and on the basis of sharing their complementary advantages. Effective technological measures are provided to the exploration of deep buried uranium bodies in the granite uranium deposits and outskirt extension of the deposit. (authors)
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Qi, Meiling; Wang, Peng; Sun, Ping; Liu, Xia
2006-03-07
A liquid chromatographic method is described for the simultaneous determination of cefalexin and trimethoprim in dog plasma. A simple protein precipitation procedure was adopted for the sample preparation with satisfactory extraction recoveries for both analytes. Chromatographic separation of the analytes was achieved on a C(18) column using a mixture of 2 mol/l formate buffer (pH 3.5), methanol and acetonitrile (22:7:7, v/v/v) containing a 0.002 mol/l sodium dodecyl sulfate as mobile phase and detection was performed at 240 nm. The linearity was obtained over the concentration ranges of 1.0-100.0 microg/ml for cefalexin and 0.5-50.0 microg/ml for trimethoprim. For each level of QC samples including the lower limit of quantification, both inter- and intra-day precisions (R.S.D.) were trimethoprim, and accuracy (RE) was -1.4% for cefalexin and -3.0% for trimethoprim. The present LC method was successfully applied to the pharmacokinetic studies of coformulated cefalexin dispersible tablets after oral administration to beagle dogs.
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Chen, Ying; Du, Kunze; Li, Jin; Bai, Yun; An, Mingrui; Tan, Zhijing
2018-01-01
A simple cloud point preconcentration method was developed and validated for the determination of gallic acid, bergenin, quercitrin, and embelin in Ardisia japonica by high-performance liquid chromatography (HPLC) using ultrasonic assisted micellar extraction. Nonionic surfactant Genapol X-080 was selected as the extraction solvent. The effects of various experimental conditions such as the type and concentration of surfactant and salt, temperature, and solution pH on the extraction of these components were studied to optimize the conditions of Ardisia japonica. The solution was incubated in a thermostatic water bath at 60°C for 10 min, and 35% NaH2PO4 (w/v) was added to the solution to promote the phase separation and increase the preconcentration factor. The intraday and interday precision (RSD) were both below 5.0% and the limits of detection (LOD) for the analytes were between 10 and 20 ng·mL−1. The proposed method provides a simple, efficient, and organic solvent-free method to analyze gallic acid, bergenin, quercitrin, and embelin for the quality control of Ardisia japonica. PMID:29487621
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Directory of Open Access Journals (Sweden)
Ying Chen
2018-01-01
Full Text Available A simple cloud point preconcentration method was developed and validated for the determination of gallic acid, bergenin, quercitrin, and embelin in Ardisia japonica by high-performance liquid chromatography (HPLC using ultrasonic assisted micellar extraction. Nonionic surfactant Genapol X-080 was selected as the extraction solvent. The effects of various experimental conditions such as the type and concentration of surfactant and salt, temperature, and solution pH on the extraction of these components were studied to optimize the conditions of Ardisia japonica. The solution was incubated in a thermostatic water bath at 60°C for 10 min, and 35% NaH2PO4 (w/v was added to the solution to promote the phase separation and increase the preconcentration factor. The intraday and interday precision (RSD were both below 5.0% and the limits of detection (LOD for the analytes were between 10 and 20 ng·mL−1. The proposed method provides a simple, efficient, and organic solvent-free method to analyze gallic acid, bergenin, quercitrin, and embelin for the quality control of Ardisia japonica.
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Directory of Open Access Journals (Sweden)
Junan Ren
Full Text Available Meat adulteration is a worldwide concern. In this paper, a new droplet digital PCR (ddPCR method was developed for the quantitative determination of the presence of chicken in sheep and goat meat products. Meanwhile, a constant (multiplication factor was introduced to transform the ratio of copy numbers to the proportion of meats. The presented ddPCR method was also proved to be more accurate (showing bias of less than 9% in the range from 5% to 80% than real-time PCR, which has been widely used in this determination. The method exhibited good repeatability and stability in different thermal treatments and at ultra-high pressure. The relative standard deviation (RSD values of 5% chicken content was less than 5.4% for ultra-high pressure or heat treatment. Moreover, we confirmed that different parts of meat had no effect on quantification accuracy of the ddPCR method. In contrast to real-time PCR, we examined the performance of ddPCR as a more precise, sensitive and stable analytical strategy to overcome potential problems of discrepancies in amplification efficiency discrepancy and to obtain the copy numbers directly without standard curves. The method and strategy developed in this study can be applied to quantify the presence and to confirm the absence of adulterants not only to sheep but also to other kinds of meat and meat products.
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Long-term in-vitro precision of direct digital X-ray radiogrammetry
International Nuclear Information System (INIS)
Dhainaut, Alvilde; Hoff, Mari; Kaelvesten, Johan; Lydersen, Stian; Forslind, Kristina; Haugeberg, Glenn
2011-01-01
Digital X-ray radiogrammetry (DXR) calculates peripheral bone mineral density (BMD) from hand radiographs. The short-term precision for direct DXR has been reported to be highly satisfactory. However, long-term precision for this method has not been examined. Thus, the aim of this study was to examine the long-term in-vitro precision for the new direct digital version of DXR. The in-vitro precision for direct DXR was tested with cadaver phantoms on four different X-ray systems at baseline, 3 months, 6 months, and in one machine also at 12 months. At each time point, 31 measurements were performed. The in-vitro longitudinal precision for the four radiographic systems ranged from 0.22 to 0.43% expressed as coefficient of variation (CV%). The smallest detectable difference (SDD) ranged from 0.0034 to 0.0054 g/cm 2 . The in vitro long-term precision for direct DXR was comparable to the previous reported short-term in-vitro precision for all tested X-ray systems. These data show that DXR is a stable method for detecting small changes in bone density during 6-12 months of follow-up. (orig.)
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Precise Plan in the analysis of volume precision in SynergyTM conebeam CT image
International Nuclear Information System (INIS)
Bai Sen; Xu Qingfeng; Zhong Renming; Jiang Xiaoqin; Jiang Qingfeng; Xu Feng
2007-01-01
Objective: A method of checking the volume precision in Synergy TM conebeam CT image. Methods: To scan known phantoms (big, middle, small spheres, cubes and cuniform cavum) at different positions (CBCT centre and departure centre from 5, 8, 10 cm along the accelerator G-T way)with conebeam CT, the phantom volume of reconstructed images were measure. Then to compared measured volume of Synergy TM conebeam CT with fanbeam CT results and nominal values. Results: The middle spheres had 1.5% discrepancy in nominal values and metrical average values at CBCT centre and departure from centre 5, 8 cm along accelerator G-T way. The small spheres showed 8.1%, with 0.8 % of the big cube and 2.9% of small cube, in nominal values and metrical average values at CBCT centre and departure from centre 5, 8, 10 cm along the accelerator G-T way. Conclusion: In valid scan range of Synergy TM conebeam CT, reconstructed precision is independent of the distance deviation from the center. (authors)
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Krishnaiah, Ch; Vishnu Murthy, M; Kumar, Ramesh; Mukkanti, K
2011-03-25
A simple, sensitive and reproducible ultra performance liquid chromatography (UPLC) coupled with a photodiode array detector method was developed for the quantitative determination of olanzapine (OLN) in API and pharmaceutical dosage forms. The method is applicable to the quantification of related substances and assays of drug substances. Chromatographic separation was achieved on Acquity UPLC BEH 100-mm, 2.1-mm, and 1.7-μm C-18 columns, and the gradient eluted within a short runtime, i.e., within 10.0 min. The eluted compounds were monitored at 250 nm, the flow rate was 0.3 mL/min, and the column oven temperature was maintained at 27°C. The resolution of OLN and eight (potential, bi-products and degradation) impurities was greater than 2.0 for all pairs of components. The high correlation coefficient (r(2)>0.9991) values indicated clear correlations between the investigated compound concentrations and their peak areas within the test ranges. The repeatability and intermediate precision, expressed by the RSD, were less than 2.4%. The accuracy and validity of the method were further ascertained by performing recovery studies via a spike method. The accuracy of the method expressed as relative error was satisfactory. No interference was observed from concomitant substances normally added to the tablets. The drug was subjected to the International Conference on Harmonization (ICH)-prescribed hydrolytic, oxidative, photolytic and thermal stress conditions. The performance of the method was validated according to the present ICH guidelines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision, ruggedness and robustness. Copyright © 2010 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Kapendra Sahu
2017-02-01
Full Text Available A novel comparative force degradation UPLC assay method was developed and validated for Piracetam and its degradation products. Piracetam was subjected to acid (5 M HCl, neutral (water and alkaline (0.5 M NaOH hydrolytic conditions at 80 °C, as well as to oxidative decomposition (H2O2 at room temperature. Photolytic studies were carried out by exposing this drug into sunlight (60,000–70,000 lux for 2 d. Additionally, the solid drug was subjected to 50 °C for 60 days in a hot air oven for thermal degradation. The UPLC chromatographic separation was performed on Acquity UPLC BEH C18 column (1.7 μm, 2.1 mm × 150 mm using isocratic mode (ACN:water, 25:75 v/v at a flow rate of 0.15 mL min−1 and HPLC chromatographic separation was achieved on phenomenex C18 using isocratic mode (ACN:10 mM ammonium acetate, pH 5.0, 20:80 v/v at a flow rate of 0.9 mL/min. Piracetam was found to degrade only in the base and shows stable behavior under all stress conditions. The UPLC and HPLC linearity of the proposed method was investigated in the range of 10–50 μg mL−1. The r2 value of UPLC and HPLC was found to be 0.999 and 0.999, respectively. Method detection limit (MDL and Method quantification limit (MQL were found to be 0.180 μg mL−1and 1.10 μg mL−1 for UPLC and 0.500 μg mL−1and 1.700 μg mL−1 for HPLC respectively. The %RSD values for intra-day and inter-day precision were <1.2%, confirming that the method was sufficiently precise. The validation studies were carried out fulfilling ICH requirements. The developed method was simple, fast, accurate and precise and hence could be applied for routine quality control analysis of Piracetam in solid dosage forms.
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International Nuclear Information System (INIS)
Kulkarni, P.G.; Gupta, K.K.; Pant, D.K.; Bhalerao, B.A.; Gurba, P.B.; Janardan, P.; Changrani, R.D.; Dey, P.K.; Pathak, P.N.; Mohapatra, P.K.; Manchanda, V.K.
2010-01-01
A simple radiometric method for 90 Sr determination in the dissolver solution of the PHWR spent fuel has been developed.The method involves the quantitative separation of Sr from the associated actinides and other fission products by solvent extraction with 30% trialkylphosphine oxide (TRPO) -n-dodecane followed by extraction chromatography with XAD-7-Di-butylcyclohexano-18-crown-6 resin. The separation scheme yields quantitative recovery of 90 Sr and the separated 90 Sr was found to be radiochemically pure. 90 Sr was estimated by β-radiometry and the precision of the method at 5 mCi/mL level was 2% (RSD). (author)
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PRECISE - pregabalin in addition to usual care: Statistical analysis plan
S. Mathieson (Stephanie); L. Billot (Laurent); C. Maher (Chris); A.J. McLachlan (Andrew J.); J. Latimer (Jane); B.W. Koes (Bart); M.J. Hancock (Mark J.); I. Harris (Ian); R.O. Day (Richard O.); J. Pik (Justin); S. Jan (Stephen); C.-W.C. Lin (Chung-Wei Christine)
2016-01-01
textabstractBackground: Sciatica is a severe, disabling condition that lacks high quality evidence for effective treatment strategies. This a priori statistical analysis plan describes the methodology of analysis for the PRECISE study. Methods/design: PRECISE is a prospectively registered, double
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International Nuclear Information System (INIS)
Hou, Sen; Tabaka, Marcin; Sun, Lili; Trochimczyk, Piotr; Kaminski, Tomasz S; Kalwarczyk, Tomasz; Zhang, Xuzhu; Holyst, Robert
2014-01-01
We developed a laser-based method to quantify the double labeling efficiency of double-stranded DNA (dsDNA) in a fluorescent dsDNA pool with fluorescence correlation spectroscopy (FCS). Though, for quantitative biochemistry, accurate measurement of this parameter is of critical importance, before our work it was almost impossible to quantify what percentage of DNA is doubly labeled with the same dye. The dsDNA is produced by annealing complementary single-stranded DNA (ssDNA) labeled with the same dye at 5′ end. Due to imperfect ssDNA labeling, the resulting dsDNA is a mixture of doubly labeled dsDNA, singly labeled dsDNA and unlabeled dsDNA. Our method allows the percentage of doubly labeled dsDNA in the total fluorescent dsDNA pool to be measured. In this method, we excite the imperfectly labeled dsDNA sample in a focal volume of <1 fL with a laser beam and correlate the fluctuations of the fluorescence signal to get the FCS autocorrelation curves; we express the amplitudes of the autocorrelation function as a function of the DNA labeling efficiency; we perform a comparative analysis of a dsDNA sample and a reference dsDNA sample, which is prepared by increasing the total dsDNA concentration c (c > 1) times by adding unlabeled ssDNA during the annealing process. The method is flexible in that it allows for the selection of the reference sample and the c value can be adjusted as needed for a specific study. We express the precision of the method as a function of the ssDNA labeling efficiency or the dsDNA double labeling efficiency. The measurement precision can be controlled by changing the c value. (letter)
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Naccarato, Attilio; Gionfriddo, Emanuela; Elliani, Rosangela; Sindona, Giovanni; Tagarelli, Antonio
2014-10-30
The analysis of characteristic urinary acidic markers such as glutaric, 3-hydroxyglutaric, 2-hydroxyglutaric, adipic, suberic, sebacic, ethylmalonic, 3-hydroxyisovaleric and isobutyric acid constitutes the recommended follow-up testing procedure for glutaric acidemia type 1 (GA-1) and type 2 (GA-2). The goal of the work herein presented is the development of a fast and simple method for the quantification of these biomarkers in human urine. The proposed analytical approach is based on the use of solid phase microextraction (SPME) combined with gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS) afterward a rapid derivatization of acidic moieties by propyl chloroformate, propanol and pyridine. Trueness and precision of the proposed protocol, tested at 5, 30 and 80mgl -1 , provided satisfactory values: recoveries were in the range between 72% and 116% and the relative standard deviations (RSD%) were between 0.9% and 18% (except for isobutyric acid at 5mgl -1 ). The LOD values achieved by the proposed method ranged between 1.0 and 473μgl -1 . Copyright © 2014 Elsevier B.V. All rights reserved.
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Precision medicine in myasthenia graves: begin from the data precision
Hong, Yu; Xie, Yanchen; Hao, Hong-Jun; Sun, Ren-Cheng
2016-01-01
Myasthenia gravis (MG) is a prototypic autoimmune disease with overt clinical and immunological heterogeneity. The data of MG is far from individually precise now, partially due to the rarity and heterogeneity of this disease. In this review, we provide the basic insights of MG data precision, including onset age, presenting symptoms, generalization, thymus status, pathogenic autoantibodies, muscle involvement, severity and response to treatment based on references and our previous studies. Subgroups and quantitative traits of MG are discussed in the sense of data precision. The role of disease registries and scientific bases of precise analysis are also discussed to ensure better collection and analysis of MG data. PMID:27127759
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Precious metal assay analysis of fresh reforming catalyst by x-ray fluorescence spectrometry
International Nuclear Information System (INIS)
McElroy, F.C.; Mulhall, J.M.
1991-01-01
This paper reports that precious metal analysis of fresh reforming catalysts are typically performed by both the catalyst manufacturer and buyer to arrive at a financial settlement on the quantity of metal in each lot of commercial catalyst. Traditional assay methods involve a variety of fire assay or wet chemical acid digestion schemes coupled with gravimetric, colorimetic, or titrimetric measurement for precious metals. Methods must have sufficient precision and accuracy to afford interlaboratory agreement of within one half of one percent relative between the catalyst supplier and purchaser. To meet this requirement many laboratories rely on classical methods. Unfortunately these proceeders are labor intensive and time consuming. X-ray fluorescence has the inherent instrument precision to achieve typical intralaboratory precision of 0.5% RSD on a wide variety of elements and numerous sample types. We have developed an X-ray fluorescence method for the assay quality analysis of fresh reforming catalyst containing platinum, rhenium, and iridium. This method was applied to numerous samples over the past five years
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Gorringe, T. P.; Hertzog, D. W.
2015-09-01
The muon is playing a unique role in sub-atomic physics. Studies of muon decay both determine the overall strength and establish the chiral structure of weak interactions, as well as setting extraordinary limits on charged-lepton-flavor-violating processes. Measurements of the muon's anomalous magnetic moment offer singular sensitivity to the completeness of the standard model and the predictions of many speculative theories. Spectroscopy of muonium and muonic atoms gives unmatched determinations of fundamental quantities including the magnetic moment ratio μμ /μp, lepton mass ratio mμ /me, and proton charge radius rp. Also, muon capture experiments are exploring elusive features of weak interactions involving nucleons and nuclei. We will review the experimental landscape of contemporary high-precision and high-sensitivity experiments with muons. One focus is the novel methods and ingenious techniques that achieve such precision and sensitivity in recent, present, and planned experiments. Another focus is the uncommonly broad and topical range of questions in atomic, nuclear and particle physics that such experiments explore.
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Directory of Open Access Journals (Sweden)
Jing-Chun Wang
2013-01-01
Full Text Available A stability-indicating HPLC method was developed and validated for the determination of berberine hydrochloride and trimethoprim in pharmaceutical dosage form in the presence of degradation products. The proposed RP-HPLC method utilizes an Agilent TC-C18, 4.6 mm × 250 mm, 5 μm, column using a mobile phase consisting of acetonitrile-50 mM potassium dihydrogen phosphate (30 : 70, v/v, pH adjusted to 3 with orthophosphoric acid at a flow rate of 1.0 mL/min and UV detection at 271 nm. The linearity of berberine hydrochloride and trimethoprim was in the range of 2 to 60 μg/mL (r=0.9996 and 1 to 30 μg/mL (r=0.9995, respectively. Repeatability and intermediate precisions were also determined with percentage relative standard deviation (% RSD less than 2.0%. The limits of detection were found to be 9.8 ng/mL for berberine hydrochloride and 2.5 ng/mL for trimethoprim. The mean recoveries for berberine hydrochloride and trimethoprim were 99.8 and 98.8%, respectively. The stability of the two drugs was determined under different conditions and the proposed method has shown effective separation for their degradation products. And the proposed assays method can thus be considered stability-indicating.
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Directory of Open Access Journals (Sweden)
Yingchun Zeng
2015-10-01
Full Text Available A rapid, sensitive and selective liquid chromatography-electrospray ionization-tandem mass spectrometric method was developed and validated for the quantification of scopoletin in rat plasma. After the addition of the internal standard xanthotoxin, plasma samples were pretreated by a simple one-step protein precipitation with acetonitrile-methanol (2:1, v/v. Chromatographic separation was achieved on a Diamonsil ODS chromatography column using gradient elution with the mobile phase consisting of acetonitrile and 0.1% formic acid. The determination was performed by positive ion electrospray ionization in multiple reaction monitoring mode. The calibration curve was linear over the concentration range of 5–1000 ng/mL (r = 0.9996. The intra- and inter-day precision (RSD% was less than 6.1%, and the accuracy (RE% was from −3.0%–2.5%. This method was successfully applied to the pharmacokinetic research of scopoletin in rats after intravenous (5 mg/kg or oral (5, 10 and 20 mg/kg administration. The result showed that oral bioavailability with a dose of 5 mg/kg was 6.62% ± 1.72%, 10 mg/kg, 5.59% ± 1.16%, and 20 mg/kg, 5.65% ± 0.75%.
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Cheng, Zhipeng; Dong, Fengshou; Xu, Jun; Liu, Xingang; Wu, Xiaohu; Chen, Zenglong; Pan, Xinglu; Zheng, Yongquan
2016-02-26
In this study, the application of atmospheric pressure gas chromatography quadrupole-time-of-flight mass spectrometry (APGC-QTOF-MS) has been investigated for simultaneous determination of fifteen organochlorine pesticides in soil and water. Soft ionization of atmospheric pressure gas chromatography was evaluated by comparing with traditional more energetic electron impact ionization (EI). APGC-QTOF-MS showed a sensitivity enhancement by approximately 7-305 times. The QuEChERs (Quick, Easy, Cheap, Effective, Rugged, and Safe) method was used to pretreat the soil samples and solid phase extraction (SPE) cleanup was used for water samples. Precision, accuracy and stability experiments were undertaken to evaluate the feasibility of the method. The results showed that the mean recoveries for all the pesticides from the soil samples were 70.3-118.9% with 0.4-18.3% intra-day relative standard deviations (RSD) and 1.0-15.6% inter-day RSD at 10, 50 and 500 μg/L levels, while the mean recoveries of water samples were 70.0-118.0% with 1.1-17.8% intra-day RSD and 0.5-12.2% inter-day RSD at 0.1, 0.5 and 1.0 μg/L levels. Excellent linearity (0.9931 ≦ r(2)≤ 0.9999) was obtained for each pesticides in the soil and water matrix calibration curves within the range of 0.01-1.0mg/L. The limits of detection (LOD) for each of the 15 pesticides was less than 3.00 μg/L, while the limit of quantification (LOQ) was less than 9.99 μg/L in soil and water. Furthermore, the developed method was successfully applied to monitor the targeted pesticides in real soil and water samples. Copyright © 2016 Elsevier B.V. All rights reserved.
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International Nuclear Information System (INIS)
Wiley, A.L. Jr.; Wirtanen, G.W.; Chien, I.-C.
1984-01-01
A combination of precision (selective, intra-arterial) chemotherapy and precision radiotherapy can be used for advanced pancreatic, biliary tract, and sarcomatous malignancies. There were some remarkable responses, but also a few poor responses and even some morbidity. Accordingly, methods are developed of pre-selecting those patients whose tumors are likely to respond to such therapy, as well as methods for improving the therapeutic ratio by the rational optimization of combined therapy. Specifically, clinical tumor blood flow characteristics (monitored with nuclear medicine techniques) may provide useful criteria for such selection. The authors also evaluate qualitatively the drug distribution or exposure space with specialized color-coded computerized tomography images, which demonstrate spatially dependent enhancement of intra-arterial contrast in tumor and in adjacent normal tissues. Such clinical data can improve the quality control aspects of intra-arterial chemotherapy administration, as well as the possibility of achievement of a significant therapeutic ratio by the integration of precision chemotherapy and precision radiation therapy. (Auth.)
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Directory of Open Access Journals (Sweden)
Shang Wang
2015-04-01
Full Text Available A methodology (HPLC proposed in this paper for simultaneously quantitative determination of ilaprazole and its related impurities in commercial tablets was developed and validated. The chromatographic separation was carried out by gradient elution using an Agilent C8 column (4.6 mm × 250 mm, 5 μm which was maintained at 25 °C. The mobile phase composed of solvent A (methanol and solvent B (solution consisting 0.02 mmol/l monopotassium phosphate and 0.025 mmol/l sodium hydroxide was at a flow rate of 1.0 ml/min. The samples were detected and quantified at 237 nm using an ultraviolet absorbance detector. Calibration curves of all analytes from 0.5 to 3.5 μg/ml were good linearity (r ≥ 0.9990 and recovery was greater than 99.5% for each analyte. The lower limit of detection (LLOD and quantification (LOQ of this analytical method were 10 ng/ml and 25 ng/ml for all impurities, respectively. The stress studies indicated that the degradation products could not interfere with the detection of ilaprazole and its related impurities and the assay can thus be considered stability-indicating. The method precisions were in the range of 0.41–1.21 while the instrument precisions were in the range of 0.38–0.95 in terms of peak area RSD% for all impurities, respectively. This method is considered stability-indicating and is applicable for accurate and simultaneous measuring of the ilaprazole and its related impurities in commercial enteric-coated tablets.
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Application of precise MPD & pressure balance cementing technology
Directory of Open Access Journals (Sweden)
Yong Ma
2018-03-01
Full Text Available The precise managed pressure drilling (MPD technology is mainly used to deal with the difficulties encountered when oil and gas open hole sections with multiple pressure systems and the strata with narrow safety density window are drilled through. If its liner cementing is carried out according to the conventional method, lost circulation is inevitable in the process of cementing while the displacement efficiency of small-clearance liner cementing is satisfied. If the positive and inverse injection technology is adopted, the cementing quality cannot meet the requirements of later well test engineering of ultradeep wells. In this paper, the cementing operation of Ø114.3 mm liner in Well Longgang 70 which was drilled in the Jiange structure of the Sichuan Basin was taken as an example to explore the application of the cementing technology based on the precise MPD and pressure balancing method to the cementing of long open-hole sections (as long as 859 m with both high and low pressures running through multiple reservoirs. On the one hand, the technical measures were taken specifically to ensure the annulus filling efficiency of slurry and the pressure balance in the whole process of cementing. And on the other hand, the annulus pressure balance was precisely controlled by virtue of precise MPD devices and by injecting heavy weight drilling fluids through central pipes, and thus the wellbore pressure was kept steady in the whole process of cementing in the strata with narrow safety density window. It is indicated that Ø114.3 mm liner cementing in this well is good with qualified pressure tests and no channeling emerges at a funnel during the staged density reduction. It is concluded that this method can enhance the liner cementing quality of complex ultradeep gas wells and improve the wellbore conditions for the later safe well tests of high-pressure gas wells. Keywords: Ultradeep well, Liner cementing, Narrow safety density window, Precise
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Precision machining commercialization
International Nuclear Information System (INIS)
1978-01-01
To accelerate precision machining development so as to realize more of the potential savings within the next few years of known Department of Defense (DOD) part procurement, the Air Force Materials Laboratory (AFML) is sponsoring the Precision Machining Commercialization Project (PMC). PMC is part of the Tri-Service Precision Machine Tool Program of the DOD Manufacturing Technology Five-Year Plan. The technical resources supporting PMC are provided under sponsorship of the Department of Energy (DOE). The goal of PMC is to minimize precision machining development time and cost risk for interested vendors. PMC will do this by making available the high precision machining technology as developed in two DOE contractor facilities, the Lawrence Livermore Laboratory of the University of California and the Union Carbide Corporation, Nuclear Division, Y-12 Plant, at Oak Ridge, Tennessee
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Wang, Xuemei; Wang, Huan; Huang, Pengfei; Ma, Xiaomin; Lu, Xiaoquan; Du, Xinzhen
2017-01-06
A superior solid-phase microextraction (SPME) fiber-coating material, three dimensional order mesoporous polymers with Ia-3d bicontinuous cubic structure (3D-OMPs) was in situ coated on a stainless steel wire by solvent evaporation induced self-assembly (EISA) and thermo-polymerization. Fourier-transform infrared spectrometry (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), small-angel X-ray diffraction (SAXRD), N 2 adsorption-desorption transmission, and thermogravimetry analysis (TGA) were applied to the characterization of the synthesized 3D-OMPs coating. The performance and feasibility of the homemade fiber was evaluated through direct immersion (DI) SPME followed by high-performance liquid chromatography-UV detector (HPLC-UV) for the simultaneous extraction of seven chlorophenols in water samples. Under the optimum conditions, the prepared fiber exhibited excellent extraction properties as compared to three commercial fibers, the DI-SPME-HPLC-UV method showed low limits of detection (0.32-1.85μgL -1 ), wide linear ranges (5.0-1000μgL -1 ), and acceptable reproducibility (relative standard deviation, RSD<7.6% for one fiber, RSD<8.9% for fiber to fiber). Moreover, the method was further successfully applied to the analysis of seven CPs in real samples with good recoveries (80.5-99.5%) and satisfactory precisions (RSD<9.2%). It was confirmed that the proposed method has high sensitivity, outstanding selectivity and good reproducibility to the determination of trace CPs in the environmental water. Copyright © 2016 Elsevier B.V. All rights reserved.
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Niu, Tian-Zeng; Zhang, Yu-Wei; Bao, Yong-Li; Wu, Yin; Yu, Chun-Lei; Sun, Lu-Guo; Yi, Jing-Wen; Huang, Yan-Xin; Li, Yu-Xin
2013-03-25
A reversed phase high performance liquid chromatography method coupled with a diode array detector (HPLC-DAD) was developed for the first time for the simultaneous determination of 9 flavonoids in Senecio cannabifolius, a traditional Chinese medicinal herb. Agilent Zorbax SB-C18 column was used at room temperature and the mobile phase was a mixture of acetonitrile and 0.5% formic acid (v/v) in water in the gradient elution mode at a flow-rate of 1.0mlmin(-1), detected at 360nm. Validation of this method was performed to verify the linearity, precision, limits of detection and quantification, intra- and inter-day variabilities, reproducibility and recovery. The calibration curves showed good linearities (R(2)>0.9995) within the test ranges. The relative standard deviation (RSD) of the method was less than 3.0% for intra- and inter-day assays. The samples were stable for at least 96h, and the average recoveries were between 90.6% and 102.5%. High sensitivity was demonstrated with detection limits of 0.028-0.085μg/ml for flavonoids. The newly established HPLC method represents a powerful technique for the quality assurance of S. cannabifolius. Copyright © 2012 Elsevier B.V. All rights reserved.
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Energy Technology Data Exchange (ETDEWEB)
Conway, Tim M., E-mail: conway.tm@gmail.com [Department of Earth and Ocean Sciences, University of South Carolina, Columbia, SC 29208 (United States); Rosenberg, Angela D. [Department of Earth and Ocean Sciences, University of South Carolina, Columbia, SC 29208 (United States); Adkins, Jess F. [California Institute of Technology, Division of Geological and Planetary Sciences, Pasadena, CA 91125 (United States); John, Seth G. [Department of Earth and Ocean Sciences, University of South Carolina, Columbia, SC 29208 (United States)
2013-09-02
Graphical abstract: ‘Metal-free’ seawater doped with varying concentrations of ‘zero’ isotope standards, processed through our simultaneous method, and then analyzed by double spike MC-ICPMS for Fe, Zn and Cd isotope ratios. All values were determined within 2 σ error (error bars shown) of zero. -- Highlights: •The first simultaneous method for isotopic analysis of Fe, Zn and Cd in seawater. •Designed for 1 L samples, a 1–20 fold improvement over previous methods. •Low blanks and high precision allow measurement of low concentration samples. •Small volume and fast processing are ideal for high-resolution large-scale studies. •Will facilitate investigation of marine trace-metal isotope cycling. -- Abstract: The study of Fe, Zn and Cd stable isotopes (δ{sup 56}Fe, δ{sup 66}Zn and δ{sup 114}Cd) in seawater is a new field, which promises to elucidate the marine cycling of these bioactive trace metals. However, the analytical challenges posed by the low concentration of these metals in seawater has meant that previous studies have typically required large sample volumes, highly limiting data collection in the oceans. Here, we present the first simultaneous method for the determination of these three isotope systems in seawater, using Nobias PA-1 chelating resin to extract metals from seawater, purification by anion exchange chromatography, and analysis by double spike MC-ICPMS. This method is designed for use on only a single litre of seawater and has blanks of 0.3, 0.06 and <0.03 ng for Fe, Zn and Cd respectively, representing a 1–20 fold reduction in sample size and a 4–130 decrease in blank compared to previously reported methods. The procedure yields data with high precision for all three elements (typically 0.02–0.2‰; 1σ internal precision), allowing us to distinguish natural variability in the oceans, which spans 1–3‰ for all three isotope systems. Simultaneous extraction and purification of three metals makes this method ideal
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Directory of Open Access Journals (Sweden)
Sarah J. Z. Hansen
2018-04-01
Full Text Available The current standard for enumeration of probiotics to obtain colony forming units by plate counts has several drawbacks: long time to results, high variability and the inability to discern between bacterial strains. Accurate probiotic cell counts are important to confirm the delivery of a clinically documented dose for its associated health benefits. A method is described using chip-based digital PCR (cdPCR to enumerate Bifidobacterium animalis subsp. lactis Bl-04 and Lactobacillus acidophilus NCFM both as single strains and in combination. Primers and probes were designed to differentiate the target strains against other strains of the same species using known single copy, genetic differences. The assay was optimized to include propidium monoazide pre-treatment to prevent amplification of DNA associated with dead probiotic cells as well as liberation of DNA from cells with intact membranes using bead beating. The resulting assay was able to successfully enumerate each strain whether alone or in multiplex. The cdPCR method had a 4 and 5% relative standard deviation (RSD for Bl-04 and NCFM, respectively, making it more precise than plate counts with an industry accepted RSD of 15%. cdPCR has the potential to replace traditional plate counts because of its precision, strain specificity and the ability to obtain results in a matter of hours.
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GTCBio's Precision Medicine Conference (July 7-8, 2016 - Boston, Massachusetts, USA).
Cole, P
2016-09-01
GTCBio's Precision Medicine Conference met this year to outline the many steps forward that precision medicine and individualized genomics has made and the challenges it still faces in technological, modeling, and standards development, interoperability and compatibility advancements, and methods of economic and societal adoption. The conference was split into four sections, 'Overcoming Challenges in the Commercialization of Precision Medicine', 'Implementation of Precision Medicine: Strategies & Technologies', 'Integrating & Interpreting Personal Genomics, Big Data, & Bioinformatics' and 'Incentivizing Precision Medicine: Regulation & Reimbursement', with this report focusing on the final two subjects. Copyright 2016 Prous Science, S.A.U. or its licensors. All rights reserved.
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Rigorous high-precision enclosures of fixed points and their invariant manifolds
Wittig, Alexander N.
The well established concept of Taylor Models is introduced, which offer highly accurate C0 enclosures of functional dependencies, combining high-order polynomial approximation of functions and rigorous estimates of the truncation error, performed using verified arithmetic. The focus of this work is on the application of Taylor Models in algorithms for strongly non-linear dynamical systems. A method is proposed to extend the existing implementation of Taylor Models in COSY INFINITY from double precision coefficients to arbitrary precision coefficients. Great care is taken to maintain the highest efficiency possible by adaptively adjusting the precision of higher order coefficients in the polynomial expansion. High precision operations are based on clever combinations of elementary floating point operations yielding exact values for round-off errors. An experimental high precision interval data type is developed and implemented. Algorithms for the verified computation of intrinsic functions based on the High Precision Interval datatype are developed and described in detail. The application of these operations in the implementation of High Precision Taylor Models is discussed. An application of Taylor Model methods to the verification of fixed points is presented by verifying the existence of a period 15 fixed point in a near standard Henon map. Verification is performed using different verified methods such as double precision Taylor Models, High Precision intervals and High Precision Taylor Models. Results and performance of each method are compared. An automated rigorous fixed point finder is implemented, allowing the fully automated search for all fixed points of a function within a given domain. It returns a list of verified enclosures of each fixed point, optionally verifying uniqueness within these enclosures. An application of the fixed point finder to the rigorous analysis of beam transfer maps in accelerator physics is presented. Previous work done by
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Wang, Qianren; Chen, Xing; Yin, Yuehong; Lu, Jian
2017-08-01
With the increasing complexity of mechatronic products, traditional empirical or step-by-step design methods are facing great challenges with various factors and different stages having become inevitably coupled during the design process. Management of massive information or big data, as well as the efficient operation of information flow, is deeply involved in the process of coupled design. Designers have to address increased sophisticated situations when coupled optimisation is also engaged. Aiming at overcoming these difficulties involved in conducting the design of the spindle box system of ultra-precision optical grinding machine, this paper proposed a coupled optimisation design method based on state-space analysis, with the design knowledge represented by ontologies and their semantic networks. An electromechanical coupled model integrating mechanical structure, control system and driving system of the motor is established, mainly concerning the stiffness matrix of hydrostatic bearings, ball screw nut and rolling guide sliders. The effectiveness and precision of the method are validated by the simulation results of the natural frequency and deformation of the spindle box when applying an impact force to the grinding wheel.
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Precise Calculation of Complex Radioactive Decay Chains
National Research Council Canada - National Science Library
Harr, Logan J
2007-01-01
...). An application of the exponential moments function is used with a transmutation matrix in the calculation of complex radioactive decay chains to achieve greater precision than can be attained through current methods...
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Directory of Open Access Journals (Sweden)
Bhupendrasinh K Vaghela
2013-01-01
Full Text Available Objective: The objective of current investigation was to study the degradation behavior of Ciprofloxacin and Tinidazole. The study was performed as per International Conference on Harmonization recommended stress condition. A novel stability-indicating reverse phase HPLC method was developed for the determination of Ciprofloxacin and Tinidazole purity in the presence of its impurities and forced degradation products. This method is also capable to separate placebo peaks as well in pharmaceutical dosage forms. The solid oral dosage form was subjected to the stress conditions such as oxidative, acid, base hydrolysis, heat and photolytic degradation. Materials and Methods: The method was developed using Waters symmetry shield, Reverse Phase (RP C18, 250mm x 4.6mm, 5΅ as a stationary phase. The mobile phase containing a gradient mixture of solvent A and B. 10mM phosphate buffer, adjusted pH 3.0 with phosphoric acid was used as a buffer. Buffer pH 3.0 was used as solvent A and buffer pH 3.0: Acetonitrile in the ratio of 20: 80 v/v were used as solvent B. The eluted compounds were monitored 278 nm (Ciprofloxacin, 317 nm (Tinidazole. The run time was 50 minute. Results: In the precision study the % RSD for the result of Ciprofloxacin, Tinidazole and its impurities was below 10%. The method was linear with the correlation coefficient greater than 0.997. The percentage recoveries were calculated and observed from 93.0% to 106.7%.The peak purity of Ciprofloxacin, Tinidazole peak had not shown any flag, thus proved the stability-indicating power of the method. Conclusion: The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness.
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Big Data’s Role in Precision Public Health
Dolley, Shawn
2018-01-01
Precision public health is an emerging practice to more granularly predict and understand public health risks and customize treatments for more specific and homogeneous subpopulations, often using new data, technologies, and methods. Big data is one element that has consistently helped to achieve these goals, through its ability to deliver to practitioners a volume and variety of structured or unstructured data not previously possible. Big data has enabled more widespread and specific research and trials of stratifying and segmenting populations at risk for a variety of health problems. Examples of success using big data are surveyed in surveillance and signal detection, predicting future risk, targeted interventions, and understanding disease. Using novel big data or big data approaches has risks that remain to be resolved. The continued growth in volume and variety of available data, decreased costs of data capture, and emerging computational methods mean big data success will likely be a required pillar of precision public health into the future. This review article aims to identify the precision public health use cases where big data has added value, identify classes of value that big data may bring, and outline the risks inherent in using big data in precision public health efforts. PMID:29594091
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Energy Technology Data Exchange (ETDEWEB)
Bluemlein, Johannes
2012-05-15
Precision measurements together with exact theoretical calculations have led to steady progress in fundamental physics. A brief survey is given on recent developments and current achievements in the field of perturbative precision calculations in the Standard Model of the Elementary Particles and their application in current high energy collider data analyses.
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International Nuclear Information System (INIS)
Bluemlein, Johannes
2012-05-01
Precision measurements together with exact theoretical calculations have led to steady progress in fundamental physics. A brief survey is given on recent developments and current achievements in the field of perturbative precision calculations in the Standard Model of the Elementary Particles and their application in current high energy collider data analyses.
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Development of andrographolide molecularly imprinted polymer for solid-phase extraction
Yin, Xiaoying; Liu, Qingshan; Jiang, Yifan; Luo, Yongming
2011-06-01
A method employing molecularly imprinted polymer (MIP) as selective sorbent for solid-phase extraction (SPE) to pretreat samples was developed. The polymers were prepared by precipitation polymerization with andrographolide as template molecule. The structure of MIP was characterized and its static adsorption capacity was measured by the Scatchard equation. In comparison with C 18-SPE and non-imprinted polymer (NIP) SPE column, MIP-SPE column displays high selectivity and good affinity for andrographolide and dehydroandrographolide for extract of herb Andrographis paniculata ( Burm.f.) Nees (APN). MIP-SPE column capacity was 11.9 ± 0.6 μmol/g and 12.1 ± 0.5 μmol/g for andrographolide and dehydroandrographolide, respectively and was 2-3 times higher than that of other two columns. The precision and accuracy of the method developed were satisfactory with recoveries between 96.4% and 103.8% (RSD 3.1-4.3%, n = 5) and 96.0% and 104.2% (RSD 2.9-3.7%, n = 5) for andrographolide and dehydroandrographolide, respectively. Various real samples were employed to confirm the feasibility of method. This developed method demonstrates the potential of molecularly imprinted solid phase extraction for rapid, selective, and effective sample pretreatment.
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Comparison of Spectrophotometric Methods for the Determination of Copper in Sugar Cane Spirit.
Soares, Sarah Adriana R; Costa, Silvânio Silvério L; Araujo, Rennan Geovanny O; Teixeira, Leonardo Sena Gomes; Dantas, Alailson Falcão
2018-05-01
Three spectrophotometric methods were developed for the determination of copper (Cu) in sugar cane spirit using the chromogenic reagents neocuproine, cuprizone, and bathocuproine. Experimental conditions, such as reagent concentration, reducer concentration, pH, buffer concentration, the order of addition of reagents, and the stability of the complexes, were optimized. The work range was established from 1.0 to 10.0 µg/mL, with correlation coefficients of >0.999 for all three optimized methods. The methods were evaluated regarding accuracy by addition and recovery tests at five concentration levels, and the obtained recoveries ranged from 91 to 105% (n = 3). Precision was expressed as RSD (relative standard deviation), with values ranging from 0.01 to 0.17% (n = 10). The method using the chromogenic reagent cuprizone presented the greatest molar absorptivity, followed by bathocuproine and neocuproine. The methods were applied for the determination of Cu in sugar cane spirit, and the results were compared with a reference method by flame atomic absorption spectrometry (FAAS). Calibration curve solutions for FAAS analysis were prepared in a 40% (v/v) alcohol medium in a range of concentrations from 0.5 up to 5 µg/mL. Measurements for Cu determination were carried out at a wavelength of 324.7 nm. The concentrations obtained for Cu in sugar cane spirit samples from Brazil were between 1.99 and 12.63 µg/mL, and about 75% of the samples presented Cu concentrations above the limit established by Brazilian legislation (5.0 µg/mL or 5.0 mg/L).
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Directory of Open Access Journals (Sweden)
Gautam Singhvi
2017-05-01
Full Text Available A simple, sensitive and rapid high performance thin layer chromatographic (HPTLC method has been developed and validated for quantitative determination of Milnacipran Hydrochloride (MIL in bulk and formulations. The chromatographic development was carried out on HPTLC plates precoated with silica gel 60 F254 using a mixture of acetonitrile, water and ammonia (6:0.6:1.6 (v/v/v as mobile phase. Detection was carried out densitometrically at 220 nm. The Rf value of drug was found to be 0.63 ± 0.02. The method was validated as per ICH guideline with respect to linearity, accuracy, precision, robustness etc. The calibration curve was found to be linear over a range of 100–1000 ng μL−1 with a regression coefficient of 0.999. The accuracy was found to be very high (99.12–100.87%. %RSD values for intra-day and inter-day variation were not more than 1.43. The method has demonstrated high sensitivity and specificity. The method was applied for compatibility studies also. The method is new, simple and economic for routine estimation of MIL in bulk, preformulation studies and pharmaceutical formulation to help the industries as well as researchers for their sensitive determination of MIL rapidly at low cost in routine analysis.
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Characterisation of surface roughness for ultra-precision freeform surfaces
International Nuclear Information System (INIS)
Li Huifen; Cheung, C F; Lee, W B; To, S; Jiang, X Q
2005-01-01
Ultra-precision freeform surfaces are widely used in many advanced optics applications which demand for having surface roughness down to nanometer range. Although a lot of research work has been reported on the study of surface generation, reconstruction and surface characterization such as MOTIF and fractal analysis, most of them are focused on axial symmetric surfaces such as aspheric surfaces. Relative little research work has been found in the characterization of surface roughness in ultra-precision freeform surfaces. In this paper, a novel Robust Gaussian Filtering (RGF) method is proposed for the characterisation of surface roughness for ultra-precision freeform surfaces with known mathematic model or a cloud of discrete points. A series of computer simulation and measurement experiments were conducted to verify the capability of the proposed method. The experimental results were found to agree well with the theoretical results
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Yandi Syukri; Agung Endro Nugroho; Ronny Martien; Endang Lukitaningsih
2015-01-01
The aim of study was to develop quantitative analysis of isolated andrographolide from Andrographis paniculata and different solvent for prelimenary studies to preperation Self Nano Emulsifying Drug Delivery System (SNEDDS) using HPLC. The separation was acquired on Sunfire C18 column with an isocratic mixture of methanol and water at a ratio of 6:4, v/v as a mobile phase. The method to determine the content of isolated andrographolide showed an adequate precision, with a RSD smaller than 1%....
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Simultaneous determination of arsenic, selenium and antimony species using HPLC/ICP-MS
Energy Technology Data Exchange (ETDEWEB)
Lindemann, T.; Prange, A.; Neidhart, B. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Physikalische und Chemische Analytik; Dannecker, W. [Univ. of Hamburg (Germany). Inst. for Inorganic and Applied Chemistry
1999-07-01
A new method for the simultaneous separation and determination of four arsenic species [As(III), As(V), monomethylarsonic acid and dimethylarsinic acid], three selenium species [Se(IV), Se(VI) and selenomethionine] as well as Sb(III) and Sb(V) is presented. The speciation was achieved by on-line coupling of anion exchange high-performance liquid chromatography (HPLC) with inductively coupled plasma mass spectrometry (ICP-MS). Chromatographic parameters such as the composition and pH of the mobile phase were optimised. Limits of detection are below 4.5 {mu}g L{sup -1} (as element) for Sb(III) and the selenium species and below 0.5 {mu}g L{sup -1} for the other species. Precisions of retention times were better than 2% RSD and of peak areas better than 8% RSD for all the species investigated. (orig.) With 5 figs., 3 tabs., 41 refs.
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Design and algorithm research of high precision airborne infrared touch screen
Zhang, Xiao-Bing; Wang, Shuang-Jie; Fu, Yan; Chen, Zhao-Quan
2016-10-01
There are shortcomings of low precision, touch shaking, and sharp decrease of touch precision when emitting and receiving tubes are failure in the infrared touch screen. A high precision positioning algorithm based on extended axis is proposed to solve these problems. First, the unimpeded state of the beam between emitting and receiving tubes is recorded as 0, while the impeded state is recorded as 1. Then, the method of oblique scan is used, in which the light of one emitting tube is used for five receiving tubes. The impeded information of all emitting and receiving tubes is collected as matrix. Finally, according to the method of arithmetic average, the position of the touch object is calculated. The extended axis positioning algorithm is characteristic of high precision in case of failure of individual infrared tube and affects slightly the precision. The experimental result shows that the 90% display area of the touch error is less than 0.25D, where D is the distance between adjacent emitting tubes. The conclusion is gained that the algorithm based on extended axis has advantages of high precision, little impact when individual infrared tube is failure, and using easily.
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Precision mechatronics based on high-precision measuring and positioning systems and machines
Jäger, Gerd; Manske, Eberhard; Hausotte, Tino; Mastylo, Rostyslav; Dorozhovets, Natalja; Hofmann, Norbert
2007-06-01
Precision mechatronics is defined in the paper as the science and engineering of a new generation of high precision systems and machines. Nanomeasuring and nanopositioning engineering represents important fields of precision mechatronics. The nanometrology is described as the today's limit of the precision engineering. The problem, how to design nanopositioning machines with uncertainties as small as possible will be discussed. The integration of several optical and tactile nanoprobes makes the 3D-nanopositioning machine suitable for various tasks, such as long range scanning probe microscopy, mask and wafer inspection, nanotribology, nanoindentation, free form surface measurement as well as measurement of microoptics, precision molds, microgears, ring gauges and small holes.
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International Nuclear Information System (INIS)
Zal Uyun Wan Mahmood; Norfaizal Mohamed; Nita Salina Abu Bakar
2016-01-01
Method validation (MV) for the measurement of gross alpha and gross beta activity in water (drinking, mineral and environmental) samples using Low Background Gross Alpha/ Beta Counting System was performed to characterize precision, accuracy and reliable results. The main objective of this assignment is to ensure that both the instrument and method always good performed and resulting accuracy and reliable results. Generally, almost the results of estimated RSD, z-score and U_s_c_o_r_e were reliable which are recorded as ≤30 %, less than 2 and less than 1.5, respectively. Minimum Detected Activity (MDA) was estimated based on the counting time of 100 minutes and present background counting value of gross alpha (0.01 - 0.35 cpm) and gross beta (0.50 - 2.18 cpm). Estimated Detection Limit (DL) was 0.1 Bq/ L for gross alpha and 0.2 Bq/ L for gross beta and expended uncertainty was relatively small of 9.77 % for gross alpha and 10.57 % for gross beta. Align with that, background counting for gross alpha and gross beta was ranged of 0.01 - 0.35 cpm and 0.50 - 2.18 cpm, respectively. While, sample volume was set at minimum of 500 mL and maximum of 2000 mL. These proven the accuracy and precision result that are generated from developed method/ technique is satisfactory and method is recommended to be used. Therefore, it can be concluded that the MV found no doubtful on the ability of the developed method. The test result showed the method is suitable for all types of water samples which are contained several radionuclides and elements as well as any impurities that interfere the measurement analysis of gross alpha and gross beta. (author)
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Joint Estimation of Multiple Precision Matrices with Common Structures.
Lee, Wonyul; Liu, Yufeng
Estimation of inverse covariance matrices, known as precision matrices, is important in various areas of statistical analysis. In this article, we consider estimation of multiple precision matrices sharing some common structures. In this setting, estimating each precision matrix separately can be suboptimal as it ignores potential common structures. This article proposes a new approach to parameterize each precision matrix as a sum of common and unique components and estimate multiple precision matrices in a constrained l 1 minimization framework. We establish both estimation and selection consistency of the proposed estimator in the high dimensional setting. The proposed estimator achieves a faster convergence rate for the common structure in certain cases. Our numerical examples demonstrate that our new estimator can perform better than several existing methods in terms of the entropy loss and Frobenius loss. An application to a glioblastoma cancer data set reveals some interesting gene networks across multiple cancer subtypes.
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About the problems and perspectives of making precision compressor blades
Directory of Open Access Journals (Sweden)
V. E. Galiev
2014-01-01
Full Text Available The problems of manufacturing blades with high precision profile geometry are considered in the article. The variant of the technology under development rules out the use of mechanical processing methods for blades airfoil. The article consists of an introduction and six small sections.The introduction sets out the requirements for modern aircraft engines, makes a list of problems arisen in the process of their manufacturing, and marks the relevance of the work.The first section analyzes the existing technology of precision blades. There is an illustration reflecting the stages of the process. Their advantages and disadvantages are marked.The second section provides an illustration, which shows the system-based blades used in the manufacturing process and a model of the work piece using the technology being developed. An analysis of each basing scheme is presented.In the third section we list the existing control methods of geometrical parameters of blades airfoil and present the measurement error data of devices. The special attention is paid to the impossibility to control the accuracy of geometrical parameters of precision blades.The fourth section presents the advantages of the electrochemical machining method with a consistent vibration of tool-electrode and with feeding the pulses of technology current over the traditional method. The article presents data accuracy and surface roughness of the blades airfoil reached owing to precision electrochemical machining. It illustrates machines that implement the given method of processing and components manufactured on them.The fifth section describes the steps of the developed process with justification for the use of the proposed operations.Based on the analysis, the author argues that the application of the proposed process to manufacture the precision compressor blades ensures producing the items that meet the requirements of the drawing.
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International Nuclear Information System (INIS)
Blanco Barrantes, Jeimy
2014-01-01
An analytical methodology is developed and validated to quantify lead in chamomile tisanes. Lead is quantified by utilizing the technique of flame atomic absorption spectroscopy in three brands of chamomile tisanes sold in Costa Rica to determine its safety and quality based on international standards. A method of sample preparation is established through a comparison of different forms of extraction. The acid digestion extraction method has been the procedure utilized, reaching an average recovery percentage of 97,1%, with a standard deviation of 2,3%. The optimization of the chosen analytical procedure and complete validation is performed. The results obtained in the validation of the analytical procedure have shown that the interval where is generated the best calibration curve in terms of the correlation coefficient and the value of the statistically significant intercept equal to zero, have been the comprised between (0,2-3,2) μg/mL (r 2 =0,9996), corresponding to a range between 20% to 320% of the maximum allowed limit. In addition, the procedure has been adequate in terms of accuracy (average recovery percentage 101,1%) and precision under repeatability and intermediate precision (RSD max. 9,3%) and limit of quantification (0,2551 μg/mL). The safety criterion of World Health Organization (WHO) is determined with respect to the concentration of lead in the analyzed products. The 9 analyzed samples of products to prepare chamomile tisanes have stayed without evidencing concentrations of lead above the limit value of 10 μg/g suggested for medicinal herbs by WHO [es
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O'Reilly, Joseph E; Puttick, Mark N; Parry, Luke; Tanner, Alastair R; Tarver, James E; Fleming, James; Pisani, Davide; Donoghue, Philip C J
2016-04-01
Different analytical methods can yield competing interpretations of evolutionary history and, currently, there is no definitive method for phylogenetic reconstruction using morphological data. Parsimony has been the primary method for analysing morphological data, but there has been a resurgence of interest in the likelihood-based Mk-model. Here, we test the performance of the Bayesian implementation of the Mk-model relative to both equal and implied-weight implementations of parsimony. Using simulated morphological data, we demonstrate that the Mk-model outperforms equal-weights parsimony in terms of topological accuracy, and implied-weights performs the most poorly. However, the Mk-model produces phylogenies that have less resolution than parsimony methods. This difference in the accuracy and precision of parsimony and Bayesian approaches to topology estimation needs to be considered when selecting a method for phylogeny reconstruction. © 2016 The Authors.
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High Precision Fast Projective Synchronization for Chaotic Systems with Unknown Parameters
Nian, Fuzhong; Wang, Xingyuan; Lin, Da; Niu, Yujun
2013-08-01
A high precision fast projective synchronization method for chaotic systems with unknown parameters was proposed by introducing optimal matrix. Numerical simulations indicate that the precision be improved about three orders compared with other common methods under the same condition of software and hardware. Moreover, when average error is less than 10-3, the synchronization speed is 6500 times than common methods, the iteration needs only 4 times. The unknown parameters also were identified rapidly. The theoretical analysis and proof also were given.
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The Analysis of Height System Definition and the High Precision GNSS Replacing Leveling Method
Directory of Open Access Journals (Sweden)
ZHANG Chuanyin
2017-08-01
Full Text Available Based on the definition of height system, the gravitational equipotential property of height datum surface is discussed in this paper, differences of the heights at ground points that defined in different height systems are tested and analyzed as well. A new method for replacing leveling using GNSS is proposed to ensure the consistency between GNSS replacing leveling and spirit leveling at mm accuracy level. The main conclusions include:①For determining normal height at centimeter accuracy level, the datum surface of normal height should be the geoid. The 1985 national height datum of China adopts normal height system, its datum surface is the geoid passing the Qingdao zero point.②The surface of equi-orthometric height in the near earth space is parallel to the geoid. The combination of GNSS precise positioning and geoid model can be directly used for orthometric height determination. However, the normal height system is more advantageous for describing the terrain and relief.③Based on the proposed method of GNSS replacing leveling, the errors in geodetic height affect more on normal height result than the errors of geoid model, the former is about 1.5 times of the latter.
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Longitudinal interfacility precision in single-energy quantitative CT
International Nuclear Information System (INIS)
Morin, R.L.; Gray, J.E.; Wahner, H.W.; Weekes, R.G.
1987-01-01
The authors investigated the precision of single-energy quantitative CT measurements between two facilities over 3 months. An anthropomorphic phantom with calcium hydroxyapatite inserts (60,100, and 160 mg/cc) was used with the Cann-Gennant method to measure bone mineral density. The same model CT scanner, anthropomorphic phantom, quantitative CT standard and analysis package were utilized at each facility. Acquisition and analysis techniques were identical to those used in patient studies. At one facility, 28 measurements yielded an average precision of 6.1% (5.0%-8.5%). The average precision for 39 measurements at the other facility was 4.3% (3.2%-8.1%). Successive scans with phantom repositioning between scanning yielded an average precision of about 3% (1%-4% without repositioning). Despite differences in personnel, scanners, standards, and phantoms, the variation between facilities was about 2%, which was within the intrafacility variation of about 5% at each location
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The theory precision analyse of RFM localization of satellite remote sensing imagery
Zhang, Jianqing; Xv, Biao
2009-11-01
The tradition method of detecting precision of Rational Function Model(RFM) is to make use of a great deal check points, and it calculates mean square error through comparing calculational coordinate with known coordinate. This method is from theory of probability, through a large number of samples to statistic estimate value of mean square error, we can think its estimate value approaches in its true when samples are well enough. This paper is from angle of survey adjustment, take law of propagation of error as the theory basis, and it calculates theory precision of RFM localization. Then take the SPOT5 three array imagery as experiment data, and the result of traditional method and narrated method in the paper are compared, while has confirmed tradition method feasible, and answered its theory precision question from the angle of survey adjustment.
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Precision shape modification of nanodevices with a low-energy electron beam
Zettl, Alex; Yuzvinsky, Thomas David; Fennimore, Adam
2010-03-09
Methods of shape modifying a nanodevice by contacting it with a low-energy focused electron beam are disclosed here. In one embodiment, a nanodevice may be permanently reformed to a different geometry through an application of a deforming force and a low-energy focused electron beam. With the addition of an assist gas, material may be removed from the nanodevice through application of the low-energy focused electron beam. The independent methods of shape modification and material removal may be used either individually or simultaneously. Precision cuts with accuracies as high as 10 nm may be achieved through the use of precision low-energy Scanning Electron Microscope scan beams. These methods may be used in an automated system to produce nanodevices of very precise dimensions. These methods may be used to produce nanodevices of carbon-based, silicon-based, or other compositions by varying the assist gas.
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Trace metal assay of uranium silicide fuel
International Nuclear Information System (INIS)
Kulkarni, M.J.; Argekar, A.A.; Thulasidas, S.K.; Dhawale, B.A.; Rajeswari, B.; Adya, V.C.; Purohit, P.J.; Neelam, G.; Bangia, T.R.; Page, A.G.; Sastry, M.D.; Iyer, R.H.
1994-01-01
A comprehensive trace metal assay of uranium silicide, a fuel for nuclear research reactors that employs low-enrichment uranium, is carried out by atomic spectrometry. Of the list of specification elements, 21 metallic elements are determined by a direct current (dc) arc carrier distillation technique; the rare earths yttrium and zirconium are chemically separated from the major matrix followed by a dc arc/inductively coupled argon plasma (ICP) excitation technique in atomic emission spectrometry (AES); silver is determined by electrothermal atomization-atomic absorption spectrometry (ETA-AAS) without prior chemical separation of the major matrix. Gamma radioactive tracers are used to check the recovery of rare earths during the chemical separation procedure. The detection limits for trace metallics vary in the 0.1- to 40-ppm range. The precision of the determinations as evaluated from the analysis of the synthetic sample with intermediate range analyte concentration is better than 25% relative standard deviation (RSD) for most of the elements employing dc arc-AES, while that for silver determination by ETS-AAS is 10% RSD. The precision of the determinations for four crucially important rare earths by ICP-AES is better than 3% RSD
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High Performance Liquid Chromatographic Analysis of Almotriptan Malate in Bulk and Tablets
Directory of Open Access Journals (Sweden)
Chandra Bala Sekaran
2013-02-01
Full Text Available Purpose: A simple RP-HPLC method has been developed and validated for the determination of almotriptan malate (ATM in bulk and tablets. Methods: Chromatographic separation of ATM was achieved by using a Thermo Scientific C18 column. A Mobile phase containing a mixture of methanol, water and acetic acid (4:8:0.1 v/v was pumped at the flow rate of 1 mL/min. Detection was performed at 227 nm. According to ICH guidelines, the method was validated. Results: The calibration curve was linear in the concentration range 5–60 μg/mL for the ATM with regression coefficient 0.9999. The method was precise with RSD <1.2%. Excellent recoveries of 99.60 - 100.80% proved the accuracy of the method. The limits of detection and quantification were found to be 0.025 and 0.075 μg/mL, respectively. Conclusion: The method was successfully applied for the quantification of ATM in tablets with acceptable accuracy and precision.
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Li, Zhi; Chen, Weidong; Lian, Feiyu; Ge, Hongyi; Guan, Aihong
2017-12-01
Quantitative analysis of component mixtures is an important application of terahertz time-domain spectroscopy (THz-TDS) and has attracted broad interest in recent research. Although the accuracy of quantitative analysis using THz-TDS is affected by a host of factors, wavelength selection from the sample's THz absorption spectrum is the most crucial component. The raw spectrum consists of signals from the sample and scattering and other random disturbances that can critically influence the quantitative accuracy. For precise quantitative analysis using THz-TDS, the signal from the sample needs to be retained while the scattering and other noise sources are eliminated. In this paper, a novel wavelength selection method based on differential evolution (DE) is investigated. By performing quantitative experiments on a series of binary amino acid mixtures using THz-TDS, we demonstrate the efficacy of the DE-based wavelength selection method, which yields an error rate below 5%.
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Computer-determined assay time based on preset precision
International Nuclear Information System (INIS)
Foster, L.A.; Hagan, R.; Martin, E.R.; Wachter, J.R.; Bonner, C.A.; Malcom, J.E.
1994-01-01
Most current assay systems for special nuclear materials (SNM) operate on the principle of a fixed assay time which provides acceptable measurement precision without sacrificing the required throughput of the instrument. Waste items to be assayed for SNM content can contain a wide range of nuclear material. Counting all items for the same preset assay time results in a wide range of measurement precision and wastes time at the upper end of the calibration range. A short time sample taken at the beginning of the assay could optimize the analysis time on the basis of the required measurement precision. To illustrate the technique of automatically determining the assay time, measurements were made with a segmented gamma scanner at the Plutonium Facility of Los Alamos National Laboratory with the assay time for each segment determined by counting statistics in that segment. Segments with very little SNM were quickly determined to be below the lower limit of the measurement range and the measurement was stopped. Segments with significant SNM were optimally assays to the preset precision. With this method the total assay time for each item is determined by the desired preset precision. This report describes the precision-based algorithm and presents the results of measurements made to test its validity
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High-precision reflectivity measurements: improvements in the calibration procedure
Jupe, Marco; Grossmann, Florian; Starke, Kai; Ristau, Detlev
2003-05-01
The development of high quality optical components is heavily depending on precise characterization procedures. The reflectance and transmittance of laser components are the most important parameters for advanced laser applications. In the industrial fabrication of optical coatings, quality management is generally insured by spectral photometric methods according to ISO/DIS 15386 on a medium level of accuracy. Especially for high reflecting mirrors, a severe discrepancy in the determination of the absolute reflectivity can be found for spectral photometric procedures. In the first part of the CHOCLAB project, a method for measuring reflectance and transmittance with an enhanced precision was developed, which is described in ISO/WD 13697. In the second part of the CHOCLAB project, the evaluation and optimization for the presented method is scheduled. Within this framework international Round-Robin experiment is currently in progress. During this Round-Robin experiment, distinct deviations could be observed between the results of high precision measurement facilities of different partners. Based on the extended experiments, the inhomogeneity of the sample reflectivity was identified as one important origin for the deviation. Consequently, this inhomogeneity is also influencing the calibration procedure. Therefore, a method was developed that allows the calibration of the chopper blade using always the same position on the reference mirror. During the investigations, the homogeneity of several samples was characterized by a surface mapping procedure for 1064 nm. The measurement facility was extended to the additional wavelength 532 nm and a similar set-up was assembled at 10.6 μm. The high precision reflectivity procedure at the mentioned wavelengths is demonstrated for exemplary measurements.
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Energy Technology Data Exchange (ETDEWEB)
Pagliano, Enea, E-mail: enea.pagliano@nrc-cnrc.gc.ca; Meija, Juris; Mester, Zoltán
2014-05-01
Highlights: • High-precision determination of nitrite and nitrate in seawater. • Use of quadruple isotope dilution. • Aqueous Et₃O⁺BF₄]⁻ derivatization chemistry for GCMS analysis of nitrite and nitrate. Abstract: Quadruple isotope dilution mass spectrometry (ID⁴MS) has been applied for simultaneous determination of nitrite and nitrate in seawater. ID⁴MS allows high-precision measurements and entails the use of isotopic internal standards (¹⁸O-nitrite and ¹⁵N-nitrate). We include a tutorial on ID⁴MS outlining optimal experimental design which generates results with low uncertainties and obviates the need for direct (separate) evaluation of the procedural blank. Nitrite and nitrate detection was achieved using a headspace GCMS procedure based on single-step aqueous derivatization with triethyloxonium tetrafluoroborate at room temperature. In this paper the sample preparation was revised and fundamental aspects of this chemistry are presented. The proposed method has detection limits in the low parts-per-billion for both analytes, is reliable, precise, and has been validated using a seawater certified reference material (MOOS-2). Simplicity of the experimental design, low detection limits, and the use of quadruple isotope dilution makes the present method superior to the state-of-the-art for determination of nitrite and nitrate, and an ideal candidate for reference measurements of these analytes in seawater.
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Directory of Open Access Journals (Sweden)
LIU Yun-xia
2015-12-01
Full Text Available The vanadium molybdate yellow colorimetric method(VMYC method is regarded as one of conventional methods for determining total phosphorus(P in plants, but it is time consuming procedure. Continuous flow analyzer(CFA is a fluid stream segmentation technique with air segments. It is used to measure P concentration based on the molybdate-antimony-ascorbic acid method of Murphy and Riley. Sixty nine of maize plant samples were selected and digested with H2SO4-H2O2. P concentrations in the digests were determined by CFA and VMYC method, respectively. The t test found that there was no any significant difference of the plant P contents measured by the CFA and the VMYC method. A linear equation could best describe their relationship: Y(CFA-P=0.927X(VMYC-P-0.002. The Pearson's correlation coefficient was 0.985 with a significance level(n=69, P<0.01. The CFA method for plant P measurement had a high precision with relative standard deviation(RSD less than 1.5%. It is suggested that the CFA based on Murphy and Riley colorimetric detection can be used to determinate total plant P in the digests solutions with H2SO4-H2O2. The CFA method is labor saving and can handle large numbers of samples. The human error in mixing with other operations is reduced to a great extent.
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Directory of Open Access Journals (Sweden)
Karunakaran Kulandaivelu
2014-01-01
Full Text Available A new method for the simultaneous determination of paracetamol (PR and lornoxicam (LR has been developed by reversed phase HPLC from the combination drug product. The separation achieved on C18 column using acetonitrile and 0.02 M potassium dihydrogen phosphate was in the ratio of 35:65 (v/v as mobile phase at a flow rate of 1.0 mL/min. Both the components were monitored at a single wavelength at 260 nm and the column temperature was maintained at 30°C throughout the analysis. A linear response was found in the concentration range of 125-375 μg/mL for PR and 2-6 μg/mL for LR, with the correlation coefficient of more than 0.999. Although the tablet contained a high dose of PR (500 mg and a low dose of LR (8 mg, the single HPLC method was developed and the intra as well as inter day precision was obtained at less than 2% of RSD. The accuracy results obtained were between 98% and 102%. The drug was intentionally degraded under acidic, basic, peroxide, thermal, and photolytic conditions. The major degradation observed for both PR and LR under peroxide condition indicated that the drug product is susceptible to oxidation. The degraded peaks were properly resolved from PR and LR. Hence, the method is stability indicating.
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Liu, Zhenzhen; Zhang, Bo; Liu, Zhihong; Li, Song; Li, Guofei; Geng, Lulu; Zhao, Xu; Bi, Kaishun; Tang, Xing; Chen, Xiaohui
2012-04-01
A UPLC-ESI-MS/MS method has been developed and validated for the determination of larotaxel in beagle dog plasma. After addition of the internal standard, plasma samples were extracted by liquid-liquid extraction with methyl tert-butyl ether and separated on a 50×2.1 mm ACQUITY 1.7 μm C18 column (Waters, USA), with acetonitrile and 5 mM ammonium acetate as mobile phase, within a runtime of 3.0 min. The analytes were detected without interference in Multiple Reaction Monitoring mode with positive electrospray ionization. The linear range was 2.5-5,000 ng/mL. The intra-day and inter-day precisions (relative standard deviation, RSD, %) were within 9.3% and 10.2%, respectively, and the accuracy (relative error, RE, %) was less than 11.5%. The validated method was successfully applied to a pharmacokinetic study of larotaxel in beagle dogs after intravenous administration of larotaxel-loaded lipid microsphere with different doses of 0.4, 0.8, and 1.6 mg/kg. The area under the concentration-time curve and the peak concentration of larotaxel seemed to increase with increasing dose proportionally, suggesting linear pharmacokinetics.
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Spike timing precision of neuronal circuits.
Kilinc, Deniz; Demir, Alper
2018-04-17
Spike timing is believed to be a key factor in sensory information encoding and computations performed by the neurons and neuronal circuits. However, the considerable noise and variability, arising from the inherently stochastic mechanisms that exist in the neurons and the synapses, degrade spike timing precision. Computational modeling can help decipher the mechanisms utilized by the neuronal circuits in order to regulate timing precision. In this paper, we utilize semi-analytical techniques, which were adapted from previously developed methods for electronic circuits, for the stochastic characterization of neuronal circuits. These techniques, which are orders of magnitude faster than traditional Monte Carlo type simulations, can be used to directly compute the spike timing jitter variance, power spectral densities, correlation functions, and other stochastic characterizations of neuronal circuit operation. We consider three distinct neuronal circuit motifs: Feedback inhibition, synaptic integration, and synaptic coupling. First, we show that both the spike timing precision and the energy efficiency of a spiking neuron are improved with feedback inhibition. We unveil the underlying mechanism through which this is achieved. Then, we demonstrate that a neuron can improve on the timing precision of its synaptic inputs, coming from multiple sources, via synaptic integration: The phase of the output spikes of the integrator neuron has the same variance as that of the sample average of the phases of its inputs. Finally, we reveal that weak synaptic coupling among neurons, in a fully connected network, enables them to behave like a single neuron with a larger membrane area, resulting in an improvement in the timing precision through cooperation.
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Practical precision measurement
International Nuclear Information System (INIS)
Kwak, Ho Chan; Lee, Hui Jun
1999-01-01
This book introduces basic knowledge of precision measurement, measurement of length, precision measurement of minor diameter, measurement of angles, measurement of surface roughness, three dimensional measurement, measurement of locations and shapes, measurement of screw, gear testing, cutting tools testing, rolling bearing testing, and measurement of digitalisation. It covers height gauge, how to test surface roughness, measurement of plan and straightness, external and internal thread testing, gear tooth measurement, milling cutter, tab, rotation precision measurement, and optical transducer.
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International Nuclear Information System (INIS)
Wardani, Sri; Rina M, Th.; L, Dyah
2000-01-01
Evaluation of precision and accuracy of Neutron Activation Analysis (NAA) method used by P2TRR performed by analyzed the standard reference samples from the National Institute of Environmental Study of Japan (NIES-CRM No.10 (rice flour) and the National Bureau of USA (NBS-SRM 1573a (tomato leave) by NAA method. In analyze the environmental SRM No.10 by NAA method in qualitatively could identified multi elements of contents, namely: Br, Ca, Co, CI, Cs, Gd, I, K< La, Mg, Mn, Na, Pa, Sb, Sm, Sr, Ta, Th, and Zn (19 elements) for SRM 1573a; As, Br, Cr, CI, Ce, Co, Cs, Fe, Ga, Hg, K, Mn, Mg, Mo, Na, Ni, Pb, Rb, Sr, Se, Sc, Sb, Ti, and Zn, (25 elements) for CRM No.10a; Ag, As, Br, Cr, CI, Ce, Cd, Co, Cs, Eu, Fe, Ga, Hg, K, Mg, Mn, Mo, Na, Nb, Pb, Rb, Sb, Sc, Th, TI, and Zn, (26 elements) for CRM No. 10b; As, Br, Co, CI, Ce, Cd, Ga, Hg, K, Mn, Mg, Mo, Na, Nb, Pb, Rb, Sb, Se, TI, and Zn (20 elementary) for CRM No.10c. In the quantitatively analysis could determined only some element of sample contents, namely: As, Co, Cd, Mo, Mn, and Zn. From the result compared with NIES or NBS values attained with deviation of 3% ∼ 15%. Overall, the result shown that the method and facilities have a good capability, but the irradiation facility and the software of spectrometry gamma ray necessary to developing or seriously research perform
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International Nuclear Information System (INIS)
Smolik, Marek; Polkowska-Motrenko, Halina; Hubicki, Zbigniew; Jakóbik-Kolon, Agata; Danko, Bożena
2014-01-01
Graphical abstract: -- Highlights: •We worked out ICP-MS method of Hf determination in Zr and Zr compounds. •We used NAA method as reference one. •We obtained pure zirconium matrix by ion exchange (Diphonix ® resin). •These permit to determine ≥1 × 10 −4 % Hf in Zr sample by ICP MS with good precision and accuracy. -- Abstract: Hafnium at the very low level of 1–8 ppm (in relation to zirconium) was determined in zirconium sulfate solutions (originating from investigations of the separation of ca. 44 ppm Hf from zirconium by means of the ion exchange method) by using three independent methods: inductively coupled plasma mass spectrometry (ICP MS), neutron activation analysis (NAA) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The results of NAA and ICP MS determinations were consistent with each other across the entire investigated range (the RSD of both methods did not exceed 38%). The results of ICP-AES determination were more diverse, particularly at less than 5 ppm Hf (RSD was significantly higher: 29–253%). The ion exchange method exploiting Diphonix ® resin proved sufficient efficiency in Zr–Hf separation when the initial concentration ratio of the elements ([Zr] 0 /[Hf] 0 ) ranged from 1200 to ca. 143,000
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Sensitivity Analysis of Deviation Source for Fast Assembly Precision Optimization
Directory of Open Access Journals (Sweden)
Jianjun Tang
2014-01-01
Full Text Available Assembly precision optimization of complex product has a huge benefit in improving the quality of our products. Due to the impact of a variety of deviation source coupling phenomena, the goal of assembly precision optimization is difficult to be confirmed accurately. In order to achieve optimization of assembly precision accurately and rapidly, sensitivity analysis of deviation source is proposed. First, deviation source sensitivity is defined as the ratio of assembly dimension variation and deviation source dimension variation. Second, according to assembly constraint relations, assembly sequences and locating, deviation transmission paths are established by locating the joints between the adjacent parts, and establishing each part’s datum reference frame. Third, assembly multidimensional vector loops are created using deviation transmission paths, and the corresponding scalar equations of each dimension are established. Then, assembly deviation source sensitivity is calculated by using a first-order Taylor expansion and matrix transformation method. Finally, taking assembly precision optimization of wing flap rocker as an example, the effectiveness and efficiency of the deviation source sensitivity analysis method are verified.
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Precise fabrication of X-band accelerating structure
International Nuclear Information System (INIS)
Higo, T.; Sakai, H.; Higashi, Y.; Koike, S.; Takatomi, T.
1994-01-01
An accelerating structure with a/λ=0.16 is being fabricated to study a precise fabrication method. A frequency control of each cell better than 10 -4 level is required to realize a detuned structure. The present machining level is nearly 1 MHz/11.4 GHz in relative frequency error, which just satisfies the above requirement. To keep this machining precision, the diffusion bonding technique is found preferable to join the cells. Various diffusion conditions were tried. The frequency change can be less than 1 MHz/11.4 GHz and it can be controlled well better than that. (author)
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Analytical method of uranium (IV) and uranium (VI) in uranium ores and uranium-bearing rocks
International Nuclear Information System (INIS)
Shen Zhuqin; Zheng Yongfeng; Li Qingzhen; Zhong Miaolan; Gu Dingxiang
1995-11-01
The best conditions for keeping the original valences of uranium during the dissolution and separation procedure of geological samples (especially those micro uranium-bearing rock) were studied. With the exist of high concentration protectants, the sample was decomposed with concentration HF at 40 +- 5 degree C. The U(VI) was dissolved completely and formed stable complex UO 2 F 2 , the U(IV) was precipitated rapidly and carried by carrier. Quantitative separation was carried out immediately with suction. The decomposition of sample and separation of solid/liquid phases was completed within two minutes. After separation, the U(IV) and U(VI) were determined quantitatively with laser fluorescence or voltametry respectively according to the uranium content. The limit of detection for this method is 0.7 μg/g, RSD is 10.5%, the determinate range of uranium is 2 x 10 -6 ∼10 -1 g/g. The uranium contents and their valence state ratio were measured for more than one hundred samples of sand stone and granite, the accuracy and precision of these results are satisfactory for uranium geological research. (12 tabs.; 11 refs.)
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Radiomic Machine Learning Classifiers for Prognostic Biomarkers of Head & Neck Cancer
Directory of Open Access Journals (Sweden)
Chintan eParmar
2015-12-01
Full Text Available Introduction: Radiomics extracts and mines large number of medical imaging features in a non-invasive and cost-effective way. The underlying assumption of radiomics is that these imaging features quantify phenotypic characteristics of entire tumor. In order to enhance applicability of radiomics in clinical oncology, highly accurate and reliable machine learning approaches are required. In this radiomic study, thirteen feature selection methods and eleven machine learning classification methods were evaluated in terms of their performance and stability for predicting overall survival in head and neck cancer patients. Methods: Two independent head and neck cancer cohorts were investigated. Training cohort HN1 consisted 101 HNSCC patients. Cohort HN2 (n=95 was used for validation. A total of 440 radiomic features were extracted from the segmented tumor regions in CT images. Feature selection and classification methods were compared using an unbiased evaluation framework. Results: We observed that the three feature selection methods MRMR (AUC = 0.69, Stability = 0.66, MIFS (AUC = 0.66, Stability = 0.69, and CIFE (AUC = 0.68, Stability = 0.7 had high prognostic performance and stability. The three classifiers BY (AUC = 0.67, RSD = 11.28, RF (AUC = 0.61, RSD = 7.36, and NN (AUC = 0.62, RSD = 10.52 also showed high prognostic performance and stability. Analysis investigating performance variability indicated that the choice of classification method is the major factor driving the performance variation (29.02% of total variance. Conclusions: Our study identified prognostic and reliable machine learning methods for the prediction of overall survival of head and neck cancer patients. Identification of optimal machine-learning methods for radiomics based prognostic analyses could broaden the scope of radiomics in precision oncology and cancer care.
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Liu, Miao; Yang, Shourui; Wang, Zhangying; Huang, Shujun; Liu, Yue; Niu, Zhenqi; Zhang, Xiaoxuan; Zhu, Jigui; Zhang, Zonghua
2016-05-30
Augmented reality system can be applied to provide precise guidance for various kinds of manual works. The adaptability and guiding accuracy of such systems are decided by the computational model and the corresponding calibration method. In this paper, a novel type of augmented reality guiding system and the corresponding designing scheme are proposed. Guided by external positioning equipment, the proposed system can achieve high relative indication accuracy in a large working space. Meanwhile, the proposed system is realized with a digital projector and the general back projection model is derived with geometry relationship between digitized 3D model and the projector in free space. The corresponding calibration method is also designed for the proposed system to obtain the parameters of projector. To validate the proposed back projection model, the coordinate data collected by a 3D positioning equipment is used to calculate and optimize the extrinsic parameters. The final projecting indication accuracy of the system is verified with subpixel pattern projecting technique.
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Elevation data fitting and precision analysis of Google Earth in road survey
Wei, Haibin; Luan, Xiaohan; Li, Hanchao; Jia, Jiangkun; Chen, Zhao; Han, Leilei
2018-05-01
Objective: In order to improve efficiency of road survey and save manpower and material resources, this paper intends to apply Google Earth to the feasibility study stage of road survey and design. Limited by the problem that Google Earth elevation data lacks precision, this paper is focused on finding several different fitting or difference methods to improve the data precision, in order to make every effort to meet the accuracy requirements of road survey and design specifications. Method: On the basis of elevation difference of limited public points, any elevation difference of the other points can be fitted or interpolated. Thus, the precise elevation can be obtained by subtracting elevation difference from the Google Earth data. Quadratic polynomial surface fitting method, cubic polynomial surface fitting method, V4 interpolation method in MATLAB and neural network method are used in this paper to process elevation data of Google Earth. And internal conformity, external conformity and cross correlation coefficient are used as evaluation indexes to evaluate the data processing effect. Results: There is no fitting difference at the fitting point while using V4 interpolation method. Its external conformity is the largest and the effect of accuracy improvement is the worst, so V4 interpolation method is ruled out. The internal and external conformity of the cubic polynomial surface fitting method both are better than those of the quadratic polynomial surface fitting method. The neural network method has a similar fitting effect with the cubic polynomial surface fitting method, but its fitting effect is better in the case of a higher elevation difference. Because the neural network method is an unmanageable fitting model, the cubic polynomial surface fitting method should be mainly used and the neural network method can be used as the auxiliary method in the case of higher elevation difference. Conclusions: Cubic polynomial surface fitting method can obviously
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A comprehensive method for evaluating precision of transfer alignment on a moving base
Yin, Hongliang; Xu, Bo; Liu, Dezheng
2017-09-01
In this study, we propose the use of the Degree of Alignment (DOA) in engineering applications for evaluating the precision of and identifying the transfer alignment on a moving base. First, we derive the statistical formula on the basis of estimations. Next, we design a scheme for evaluating the transfer alignment on a moving base, for which the attitude error cannot be directly measured. Then, we build a mathematic estimation model and discuss Fixed Point Smoothing (FPS), Returns to Scale (RTS), Inverted Sequence Recursive Estimation (ISRE), and Kalman filter estimation methods, which can be used when evaluating alignment accuracy. Our theoretical calculations and simulated analyses show that the DOA reflects not only the alignment time and accuracy but also differences in the maneuver schemes, and is suitable for use as an integrated evaluation index. Furthermore, all four of these algorithms can be used to identify the transfer alignment and evaluate its accuracy. We recommend RTS in particular for engineering applications. Generalized DOAs should be calculated according to the tactical requirements.
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Amanolahi, Farjad; Mohammadi, Ali; Kazemi Oskuee, Reza; Nassirli, Hooriyeh; Malaekeh-Nikouei, Bizhan
2017-01-01
Objective: This study was designed to develop and validate a new reversed-phase high-performance liquid chromatography (RP-HPLC) method based on Q2 (R1) International Conference on Harmonization (ICH) guideline for determination of curcumin in pharmaceutical samples. Materials and Methods: The HPLC instrument method was optimized with isocratic elution with acetonitrile: ammonium acetate (45:55, v/v, pH 3.5), C18 column (150 mm×4.6 mm×5 µm particle size) and a flow rate of 1 ml/min in ambient condition and total retention time of 17 min. The volume of injection was set at 20 µl and detection was recorded at 425 nm. The robustness of the method was examined by changing the mobile phase composition, mobile phase pH, and flow rate. Results: The method was validated with respect to precision, accuracy and linearity in a concentration range of 2-100 µg/ml. The limit of detection (LOD) and limit of quantification (LOQ) were 0.25 and 0.5 µg/ml, respectively. The percentage of recovery was 98.9 to 100.5 with relative standard deviation (RSD) < 0.638%. Conclusion: The method was found to be simple, sensitive and rapid for determination of curcumin in pharmaceutical samples and had enough sensitivity to detect degradation product of curcumin produced under photolysis and hydrolysis stress condition. PMID:29062806
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Precision luminosity measurement at LHCb with beam-gas imaging
Barschel, Colin
The luminosity is the physical quantity which relates the cross-section to the production rate in collider experiments. The cross-section being the particle physics observable of interest, a precise determination of the luminosity is required. This work presents the absolute luminosity calibration results performed at the Large Hadron Collider beauty (LHCb) experiment at CERN using a novel method based on beam-gas interactions with data acquired at a center of mass energy $\\sqrt{s}=8$ TeV and $\\sqrt{s}=2.76$ TeV. Reconstructed beam-gas interaction vertices in LHCb are used to measure the beam profiles, thus making it possible to determine the beams overlap integral. An important element of this work was to install and use a neon gas injection system to increase the beam-gas interaction rate. The precision reached with the beam-gas imaging method relies on the two-dimensional beam shape determination developed in this work. For such precision, the interaction vertex resolution is an important ingredient. There...
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Naveen, P; Lingaraju, H B; Prasad, K Shyam
2017-01-01
Mangiferin, a polyphenolic xanthone glycoside from Mangifera indica , is used as traditional medicine for the treatment of numerous diseases. The present study was aimed to develop and validate a reversed-phase high-performance liquid chromatography (RP-HPLC) method for the quantification of mangiferin from the bark extract of M. indica . RP-HPLC analysis was performed by isocratic elution with a low-pressure gradient using 0.1% formic acid: acetonitrile (87:13) as a mobile phase with a flow rate of 1.5 ml/min. The separation was done at 26°C using a Kinetex XB-C18 column as stationary phase and the detection wavelength at 256 nm. The proposed method was validated for linearity, precision, accuracy, limit of detection, limit of quantification, and robustness by the International Conference on Harmonisation guidelines. In linearity, the excellent correlation coefficient more than 0.999 indicated good fitting of the curve and also good linearity. The intra- and inter-day precision showed high reliability and reproducibility of the method. The recovery values at three different levels (50%, 100%, and 150%) of spiked samples were found to be 100.47, 100.89, and 100.99, respectively, and low standard deviation value high accuracy of the method. In robustness, the results remain unaffected by small variation in the analytical parameters, which shows the robustness of the method. Liquid chromatography-mass spectrometry analysis confirmed the presence of mangiferin with M/Z value of 421. The assay developed by HPLC method is a simple, rapid, and reliable for the determination of mangiferin from M. indica . The present study was intended to develop and validate an RP-HPLC method for the quantification of mangiferin from the bark extract of M. indica . The developed method was validated for linearity, precision, accuracy, limit of detection, limit of quantification and robustness by International Conference on Harmonization guidelines. This study proved that the developed
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Morales-Cid, Gabriel; Simonet, Bartolomé M; Cárdenas, Soledad; Valcárcel, Miguel
2007-05-01
On many occasions, sample treatment is a critical step in electrophoretic analysis. As an alternative to batch procedures, in this work, a new strategy is presented with a view to develop an on-capillary sample cleanup method. This strategy is based on the partial filling of the capillary with carboxylated single-walled carbon nanotube (c-SWNT). The nanoparticles retain interferences from the matrix allowing the determination and quantification of carbohydrates (viz glucose, maltose and fructose). The precision of the method for the analysis of real samples ranged from 5.3 to 6.4%. The proposed method was compared with a method based on a batch filtration of the juice sample through diatomaceous earth and further electrophoretic determination. This method was also validated in this work. The RSD for this other method ranged from 5.1 to 6%. The results obtained by both methods were statistically comparable demonstrating the accuracy of the proposed methods and their effectiveness. Electrophoretic separation of carbohydrates was achieved using 200 mM borate solution as a buffer at pH 9.5 and applying 15 kV. During separation, the capillary temperature was kept constant at 40 degrees C. For the on-capillary cleanup method, a solution containing 50 mg/L of c-SWNTs prepared in 300 mM borate solution at pH 9.5 was introduced for 60 s into the capillary just before sample introduction. For the electrophoretic analysis of samples cleaned in batch with diatomaceous earth, it is also recommended to introduce into the capillary, just before the sample, a 300 mM borate solution as it enhances the sensitivity and electrophoretic resolution.
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Precision medicine for cancer with next-generation functional diagnostics.
Friedman, Adam A; Letai, Anthony; Fisher, David E; Flaherty, Keith T
2015-12-01
Precision medicine is about matching the right drugs to the right patients. Although this approach is technology agnostic, in cancer there is a tendency to make precision medicine synonymous with genomics. However, genome-based cancer therapeutic matching is limited by incomplete biological understanding of the relationship between phenotype and cancer genotype. This limitation can be addressed by functional testing of live patient tumour cells exposed to potential therapies. Recently, several 'next-generation' functional diagnostic technologies have been reported, including novel methods for tumour manipulation, molecularly precise assays of tumour responses and device-based in situ approaches; these address the limitations of the older generation of chemosensitivity tests. The promise of these new technologies suggests a future diagnostic strategy that integrates functional testing with next-generation sequencing and immunoprofiling to precisely match combination therapies to individual cancer patients.
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French Meteor Network for High Precision Orbits of Meteoroids
Atreya, P.; Vaubaillon, J.; Colas, F.; Bouley, S.; Gaillard, B.; Sauli, I.; Kwon, M. K.
2011-01-01
There is a lack of precise meteoroids orbit from video observations as most of the meteor stations use off-the-shelf CCD cameras. Few meteoroids orbit with precise semi-major axis are available using film photographic method. Precise orbits are necessary to compute the dust flux in the Earth s vicinity, and to estimate the ejection time of the meteoroids accurately by comparing them with the theoretical evolution model. We investigate the use of large CCD sensors to observe multi-station meteors and to compute precise orbit of these meteoroids. An ideal spatial and temporal resolution to get an accuracy to those similar of photographic plates are discussed. Various problems faced due to the use of large CCD, such as increasing the spatial and the temporal resolution at the same time and computational problems in finding the meteor position are illustrated.
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Precision half-life measurement of 11C: The most precise mirror transition F t value
Valverde, A. A.; Brodeur, M.; Ahn, T.; Allen, J.; Bardayan, D. W.; Becchetti, F. D.; Blankstein, D.; Brown, G.; Burdette, D. P.; Frentz, B.; Gilardy, G.; Hall, M. R.; King, S.; Kolata, J. J.; Long, J.; Macon, K. T.; Nelson, A.; O'Malley, P. D.; Skulski, M.; Strauss, S. Y.; Vande Kolk, B.
2018-03-01
Background: The precise determination of the F t value in T =1 /2 mixed mirror decays is an important avenue for testing the standard model of the electroweak interaction through the determination of Vu d in nuclear β decays. 11C is an interesting case, as its low mass and small QE C value make it particularly sensitive to violations of the conserved vector current hypothesis. The present dominant source of uncertainty in the 11CF t value is the half-life. Purpose: A high-precision measurement of the 11C half-life was performed, and a new world average half-life was calculated. Method: 11C was created by transfer reactions and separated using the TwinSol facility at the Nuclear Science Laboratory at the University of Notre Dame. It was then implanted into a tantalum foil, and β counting was used to determine the half-life. Results: The new half-life, t1 /2=1220.27 (26 ) s, is consistent with the previous values but significantly more precise. A new world average was calculated, t1/2 world=1220.41 (32 ) s, and a new estimate for the Gamow-Teller to Fermi mixing ratio ρ is presented along with standard model correlation parameters. Conclusions: The new 11C world average half-life allows the calculation of a F tmirror value that is now the most precise value for all superallowed mixed mirror transitions. This gives a strong impetus for an experimental determination of ρ , to allow for the determination of Vu d from this decay.
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Faraji, Mohammad; Hamdamali, Mohammadrezza; Aryanasab, Fezzeh; Shabanian, Meisam
2018-07-13
In this research, an ultrasonic-assisted extraction followed by 2-naphthalenthiol derivatization and dispersive liquid-liquid microextraction of acrylamide (AA) was developed as simple and sensitive sample preparation method for AA in bread and biscuit samples using high performance liquid chromatography. Influence of derivatization and microextraction parameters were evaluated and optimized. Results showed that the derivatization of AA leads to improve its hydrophobicity and chromatographic behavior. Under optimum conditions of derivatization and microextraction, the method yielded a linear calibration curve ranging from 10 to 1000 μg L -1 with a determination coefficient (R 2 ) of 0.9987. Limit of detection (LOD) and limit of quantification (LOQ) were 3.0 and 9.0 μg L -1 , respectively. Intra-day (n = 6) and inter-day (n = 3) precisions based on relative standard deviation percent (RSD%) for extraction and determination of AA at 50 and 500 μg L -1 levels were less than 9.0%. Finally, the performance of proposed method was investigated for determination of AA in some bread and biscuit samples, and satisfactory results were obtained (relative recovery ≥ 90%). Copyright © 2018. Published by Elsevier B.V.
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Fernández-González, V; Moscoso-Pérez, C; Muniategui-Lorenzo, S; López-Mahía, P; Prada-Rodríguez, D
2017-01-01
In this work, a new reliable, simple and fast method for the determination of six PAEs in sediments, based on ultrasonic solvent extraction (USE) followed by head space solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry determination (GC-MS), is proposed. The extraction parameters were studied, and the most favourable conditions were selected. The analytical features of the method were calculated: matrix effect, accuracy (ranged from 90% to 111%), repeatability and intermediate precision (RSD <10%), detection and quantification limits of the method (ranged from 0.001µgg -1 (DOP) to 0.142µgg -1 (DEP)), and satisfactory results were obtained. Major advantages of this approach are low consumption of reagents and solvents, no clean-up or evaporation steps were required and minimum sample manipulation. In addition, cross contamination from glassware, solvents and samples is minimized, thus procedural blanks are keeping to a minimum.. The applicability of the proposed method was demonstrated analysing sediment samples from Galician coast (NW Spain). The proposed method allows the application in routine laboratory conditions and its implementation in environmental monitoring studies under the European Water Framework Directive (WFD) and Marine Strategy Framework Directive (MSFD). Copyright © 2016 Elsevier B.V. All rights reserved.
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Lusianti, E.; Wibowo, R.; Hudiyono, S.
2018-01-01
Azelaic acid is one of the substances that has anti-acne and skin lightening effects which is often added to cosmetics. In the acne treatment, the azelaic acid is generally used with a concentration of 20% in cream formulation and 15% in gel. The use at concentrations below 10% is not recommended because it does not work effectively. While the use of above 10% is categorized as a medical treatment. In Indonesia, the Head of the National Agency of Drug and Food Control (BPOM) has issued Regulation No. 18 of 2015 on the Technical Requirements of Cosmetics Ingredients Annex V stating that the azelaic acid is banned in cosmetics. However, until this research began the BPOM has not had a valid method to identify it in cosmetics. Consequently, surveillance of such ingredient in products is hard to do. In this research, the fatty acid standard analysis method of AOAC International was modified and validated to be used in the laboratory. The method of analysis involves heating the cream preparations dissolved with methanol and then added BF3-methanol catalyst, followed by extraction and analysis using GCMS. The validation of method shows that the calibration curve is linear with correlative value of 0.9997. The method is fairly sensitive with 0.02% detection limit, and fairly precision with relative standard deviation (RSD) of between 0.626-0.961% and fairly accurate which the recovery percentage is 99.85% at range 98.27-100.72%. In sum the results demonstrate that the method can be used as a routine analysis method for laboratory testing.
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Directory of Open Access Journals (Sweden)
Nagaraju Rajendraprasad
2011-03-01
Full Text Available Quetiapine fumarate (QTF is a selective monoaminergic antagonist with high affinity for the serotonin Type 2 (5HT2, and dopamine type 2 (D2 receptors. Titrimetric and spectrophotometric assay of quetiapine fumarate (QTF using perchloric acid and acetic acid as reagents are described. The first method (method A is a non-aqueous titrimetric method and is based on the titration of QTF in glacial acetic acid with 0.01 M acetous perchloric acid using crystal violet as indicator. In the second method (method B, QTF has been measured in 0.1M acetic acid spectrophotometrically at a wavelength of 222 nm. The titri¬metric method was applicable over the range of 2.0–20.0 mg of QTF. The reac¬tion stoichiometry of 1:3 is obtained which served as the basis for calculation. In spectrophotometry, Beer’s law was obeyed over the concentration range of 1.25–15.0 µg mL-1. The linear regression equation of the calibration graph was A = 0.0115 + 0.0673c with a regression coefficient (r of 0.9986 (n = 7. The apparent molar absorptivity was calculated to be 4.25104 L mol-1cm-1 and the Sandell sensitivity was 0.0145 µg cm-2. The limits of detection (LOD and quantification (LOQ calculated as per the ICH guidelines were 0.07 and 0.21 µg mL-1, respectively. Accuracy and precision of the assays were determined by computing the intra-day and inter-day variations at three different levels of QTF. The intra-day and inter-day relative standard deviation (%RSD were in the range of 0.99–2.88 and 1.65–2.32%, for method A and B, respectively, with an acceptable percentage relative error (%RE < 2%. The methods were successfully applied to the determination of QTF in two different brands of tablets with good accuracy and precision and without detectable interference by excipients. The methods have demonstrated to be simple and easy to apply in routine usage and do not need any costly instrumentation. Therefore, the proposed procedures are advantageous and can be
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Precise Point Positioning with Partial Ambiguity Fixing.
Li, Pan; Zhang, Xiaohong
2015-06-10
Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate.
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Conway, Tim M; Rosenberg, Angela D; Adkins, Jess F; John, Seth G
2013-09-02
The study of Fe, Zn and Cd stable isotopes (δ(56)Fe, δ(66)Zn and δ(114)Cd) in seawater is a new field, which promises to elucidate the marine cycling of these bioactive trace metals. However, the analytical challenges posed by the low concentration of these metals in seawater has meant that previous studies have typically required large sample volumes, highly limiting data collection in the oceans. Here, we present the first simultaneous method for the determination of these three isotope systems in seawater, using Nobias PA-1 chelating resin to extract metals from seawater, purification by anion exchange chromatography, and analysis by double spike MC-ICPMS. This method is designed for use on only a single litre of seawater and has blanks of 0.3, 0.06 and <0.03 ng for Fe, Zn and Cd respectively, representing a 1-20 fold reduction in sample size and a 4-130 decrease in blank compared to previously reported methods. The procedure yields data with high precision for all three elements (typically 0.02-0.2‰; 1σ internal precision), allowing us to distinguish natural variability in the oceans, which spans 1-3‰ for all three isotope systems. Simultaneous extraction and purification of three metals makes this method ideal for high-resolution, large-scale endeavours such as the GEOTRACES program. Copyright © 2013 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Ahmed A. Abdel Gaber
2017-05-01
Full Text Available A sensitive, simple and rapid square-wave adsorptive stripping voltammetric method was developed and validated for the determination of Ribavirin in pharmaceutical formulations. The proposed method was based on the electrochemical reduction of Ribavirin at a hanging mercury drop electrode in Britton Robinson buffer at pH 10. A well-defined peak was observed at 880 mV with 30 s of accumulation time and 50 mV of accumulation potential. Under these optimized conditions, the square-wave adsorptive stripping voltammetric peak current showed a linear correlation on drug concentration over the range of 1 × 10−10–2 × 10−7 mol L−1 with a correlation coefficient of 0.9995 for the proposed method. The detection and quantitation limits for this method were 2.02 × 10−10 and 6.80 × 10−10 mol L−1, respectively. The results obtained for intra-day and inter-day precision (as RSD % were between 0.447% and 1.024%. This method was applied successfully for the determination of Ribavirin in its pharmaceutical dosage forms with mean recoveries of 99.68 ± 0.13 with RSD % of 0.81% and 99.20 ± 0.24 with RSD % of 0.49% for two concentrations 5 × 10−9 and 5 × 10−8 mol L−1, respectively for 200 mg capsules. The results obtained from the developed square-wave adsorptive stripping voltammetric method were compared with those obtained by the analytical method reported in the literature.
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Directory of Open Access Journals (Sweden)
Pierluigi Monaco
2016-10-01
Full Text Available Precision cosmology has recently triggered new attention on the topic of approximate methods for the clustering of matter on large scales, whose foundations date back to the period from the late 1960s to early 1990s. Indeed, although the prospect of reaching sub-percent accuracy in the measurement of clustering poses a challenge even to full N-body simulations, an accurate estimation of the covariance matrix of clustering statistics, not to mention the sampling of parameter space, requires usage of a large number (hundreds in the most favourable cases of simulated (mock galaxy catalogs. Combination of few N-body simulations with a large number of realizations performed with approximate methods gives the most promising approach to solve these problems with a reasonable amount of resources. In this paper I review this topic, starting from the foundations of the methods, then going through the pioneering efforts of the 1990s, and finally presenting the latest extensions and a few codes that are now being used in present-generation surveys and thoroughly tested to assess their performance in the context of future surveys.
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Bit-Grooming: Shave Your Bits with Razor-sharp Precision
Zender, C. S.; Silver, J.
2017-12-01
Lossless compression can reduce climate data storage by 30-40%. Further reduction requires lossy compression that also reduces precision. Fortunately, geoscientific models and measurements generate false precision (scientifically meaningless data bits) that can be eliminated without sacrificing scientifically meaningful data. We introduce Bit Grooming, a lossy compression algorithm that removes the bloat due to false-precision, those bits and bytes beyond the meaningful precision of the data.Bit Grooming is statistically unbiased, applies to all floating point numbers, and is easy to use. Bit-Grooming reduces geoscience data storage requirements by 40-80%. We compared Bit Grooming to competitors Linear Packing, Layer Packing, and GRIB2/JPEG2000. The other compression methods have the edge in terms of compression, but Bit Grooming is the most accurate and certainly the most usable and portable.Bit Grooming provides flexible and well-balanced solutions to the trade-offs among compression, accuracy, and usability required by lossy compression. Geoscientists could reduce their long term storage costs, and show leadership in the elimination of false precision, by adopting Bit Grooming.
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Precision tests of CPT invariance with single trapped antiprotons
Energy Technology Data Exchange (ETDEWEB)
Ulmer, Stefan [RIKEN, Ulmer Initiative Research Unit, Wako, Saitama (Japan); Collaboration: BASE-Collaboration
2015-07-01
The reason for the striking imbalance of matter and antimatter in our Universe has yet to be understood. This is the motivation and inspiration to conduct high precision experiments comparing the fundamental properties of matter and antimatter equivalents at lowest energies and with greatest precision. According to theory, the most sensitive tests of CPT invariance are measurements of antihydrogen ground-state hyperfine splitting as well as comparisons of proton and antiproton magnetic moments. Within the BASE collaboration we target the latter. By using a double Penning trap we performed very recently the first direct high precision measurement of the proton magnetic moment. The achieved fractional precision of 3.3 ppb improves the currently accepted literature value by a factor of 2.5. Application of the method to a single trapped antiproton will improve precision of the particles magnetic moment by more than a factor of 1000, thus providing one of the most stringent tests of CPT invariance. In my talk I report on the status and future perspectives of our efforts.
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Lutka, Anna; Maruszewska, Małgorzata
2011-01-01
It were established and validated the conditions of voltammetric determination of copper in pharmaceutical preparations. The three selected preparations: Zincuprim (A), Wapń, cynk, miedź z wit. C (B), Vigor complete (V) contained different salts and different quantity of copper (II) and increasing number of accompanied ingredients. For the purpose to transfer copper into solution, the samples of powdered tablets of the first and second preparation were undergone extraction and of the third the mineralization procedures. The concentration of copper in solution was determined by differential pulse voltammetry (DP) using comparison with standard technique. In the validation process, the selectivity, accuracy, precision and linearity of DP determination of copper in three preparations were estimated. Copper was determined within the concentration range of 1-9 ppm (1-9 microg/mL): the mean recoveries approached 102% (A), 100% (B), 102% (V); the relative standard deviations of determinations (RSD) were 0.79-1.59% (A), 0.62-0.85% (B) and 1.68-2.28% (V), respectively. The mean recoveries and the RSDs of determination satisfied the requirements for the analyte concentration at the level 1-10 ppm. The statistical verification confirmed that the tested voltammetric method is suitable for determination of copper in pharmaceutical preparation.
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A modified time-of-flight method for precise determination of high speed ratios in molecular beams
Energy Technology Data Exchange (ETDEWEB)
Salvador Palau, A.; Eder, S. D., E-mail: sabrina.eder@uib.no; Kaltenbacher, T.; Samelin, B.; Holst, B. [Department of Physics and Technology, University of Bergen, Allégaten 55, 5007 Bergen (Norway); Bracco, G. [Department of Physics and Technology, University of Bergen, Allégaten 55, 5007 Bergen (Norway); CNR-IMEM, Department of Physics, University of Genova, V. Dodecaneso 33, 16146 Genova (Italy)
2016-02-15
Time-of-flight (TOF) is a standard experimental technique for determining, among others, the speed ratio S (velocity spread) of a molecular beam. The speed ratio is a measure for the monochromaticity of the beam and an accurate determination of S is crucial for various applications, for example, for characterising chromatic aberrations in focussing experiments related to helium microscopy or for precise measurements of surface phonons and surface structures in molecular beam scattering experiments. For both of these applications, it is desirable to have as high a speed ratio as possible. Molecular beam TOF measurements are typically performed by chopping the beam using a rotating chopper with one or more slit openings. The TOF spectra are evaluated using a standard deconvolution method. However, for higher speed ratios, this method is very sensitive to errors related to the determination of the slit width and the beam diameter. The exact sensitivity depends on the beam diameter, the number of slits, the chopper radius, and the chopper rotation frequency. We present a modified method suitable for the evaluation of TOF measurements of high speed ratio beams. The modified method is based on a systematic variation of the chopper convolution parameters so that a set of independent measurements that can be fitted with an appropriate function are obtained. We show that with this modified method, it is possible to reduce the error by typically one order of magnitude compared to the standard method.
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An improved gravity compensation method for high-precision free-INS based on MEC–BP–AdaBoost
International Nuclear Information System (INIS)
Zhou, Xiao; Yang, Gongliu; Wang, Jing; Li, Jing
2016-01-01
In recent years, with the rapid improvement of inertial sensors (accelerometers and gyroscopes), gravity compensation has become more important for improving navigation accuracy in inertial navigation systems (INS), especially for high-precision INS. This paper proposes a mind evolutionary computation (MEC) back propagation (BP) AdaBoost algorithm neural-network-based gravity compensation method that estimates the gravity disturbance on the track based on measured gravity data. A MEC–BP–AdaBoost network-based gravity compensation algorithm used in the training process to establish the prediction model takes the carrier position (longitude and latitude) provided by INS as the input data and the gravity disturbance as the output data, and then compensates the obtained gravity disturbance into the INS’s error equations to restrain the position error propagation. The MEC–BP–AdaBoost algorithm can not only effectively avoid BP neural networks being trapped in local extrema, but also perfectly solve the nonlinearity between the input and output data that cannot be solved by traditional interpolation methods, such as least-square collocation (LSC) interpolation. The accuracy and feasibility of the proposed interpolation method are verified through numerical tests. A comparison of several other compensation methods applied in field experiments, including LSC interpolation and traditional BP interpolation, highlights the superior performance of the proposed method. The field experiment results show that the maximum value of the position error can reduce by 28% with the proposed gravity compensation method. (paper)
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Bocato, Mariana Zuccherato; Bortoleto, Marcela Armelim; Pupo, Mônica Tallarico; de Oliveira, Anderson Rodrigo Moraes
2014-10-01
The present work describes, for the first time, the simultaneous separation of oxcarbazepine (OXC) and its active metabolite 10-hydroxy-10,11-dihydrocarbamazepine (licarbazepine, Lic) by chiral CE. The developed method was employed to monitor the enantioselective biotransformation of OXC into its active metabolite by fungi. The electrophoretic separations were performed using 10 mmol/L of a Tris-phosphate buffer solution (pH 2.5) containing 1% w/v of β-CD phosphate sodium salt (P-β-CD) as running electrolyte, -20 kV of applied voltage and a 15°C capillary temperature. The method was linear over the concentration range of 1000-30 000 ng/mL for OXC and 75-900 ng/mL for each Lic enantiomer (r ≥ 0.9952). Within-day precision and accuracy evaluated by RSD and relative errors, respectively, were lower than 15% for all analytes. The validated method was used to evaluate the enantioselective biotransformation of OXC, mediated by fungi, into its active metabolite Lic. This study showed that the fungi Glomerella cingulata (VA1) and Beuveria bassiana were able to enantioselectively metabolize the OXC into Lic after 360 h of incubation. Biotransformation by the fungus Beuveria bassiana showed 79% enantiomeric excess for (S)-(+)-Lic, while VA1 gave an enantiomeric excess of 100% for (S)-(+)-Lic. This study opens a new route to the drug (S)-(+)-licarbazepine. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Gounder, Murugesan K; Lin, Hongxia; Stein, Mark; Goodin, Susan; Bertino, Joseph R; Kong, Ah-Ng Tony; DiPaola, Robert S
2012-05-01
2-Deoxyglucose (2-DG), an analog of glucose, is widely used to interfere with glycolysis in tumor cells and studied as a therapeutic approach in clinical trials. To evaluate the pharmacokinetics of 2-DG, we describe the development and validation of a sensitive HPLC fluorescent method for the quantitation of 2-DG in plasma. Plasma samples were deproteinized with methanol and the supernatant was dried at 45°C. The residues were dissolved in methanolic sodium acetate-boric acid solution. 2-DG and other monosaccharides were derivatized to 2-aminobenzoic acid derivatives in a single step in the presence of sodium cyanoborohydride at 80°C for 45 min. The analytes were separated on a YMC ODS C₁₈ reversed-phase column using gradient elution. The excitation and emission wavelengths were set at 360 and 425 nm. The 2-DG calibration curves were linear over the range of 0.63-300 µg/mL with a limit of detection of 0.5 µg/mL. The assay provided satisfactory intra-day and inter-day precision with RSD less than 9.8%, and the accuracy ranged from 86.8 to 110.0%. The HPLC method is reproducible and suitable for the quantitation of 2-DG in plasma. The method was successfully applied to characterize the pharmacokinetics profile of 2-DG in patients with advanced solid tumors. Copyright © 2011 John Wiley & Sons, Ltd.
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An Empirical Study of Precise Interprocedural Array Analysis
Directory of Open Access Journals (Sweden)
Michael Hind
1994-01-01
Full Text Available In this article we examine the role played by the interprocedural analysis of array accesses in the automatic parallelization of Fortran programs. We use the PTRAN system to provide measurements of several benchmarks to compare different methods of representing interprocedurally accessed arrays. We examine issues concerning the effectiveness of automatic parallelization using these methods and the efficiency of a precise summarization method.
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Design and control of the precise tracking bed based on complex electromechanical design theory
Ren, Changzhi; Liu, Zhao; Wu, Liao; Chen, Ken
2010-05-01
The precise tracking technology is wide used in astronomical instruments, satellite tracking and aeronautic test bed. However, the precise ultra low speed tracking drive system is one high integrated electromechanical system, which one complexly electromechanical design method is adopted to improve the efficiency, reliability and quality of the system during the design and manufacture circle. The precise Tracking Bed is one ultra-exact, ultra-low speed, high precision and huge inertial instrument, which some kind of mechanism and environment of the ultra low speed is different from general technology. This paper explores the design process based on complex electromechanical optimizing design theory, one non-PID with a CMAC forward feedback control method is used in the servo system of the precise tracking bed and some simulation results are discussed.
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Directory of Open Access Journals (Sweden)
ZORAN B. TODOROVIĆ
2009-09-01
Full Text Available In the pharmaceutical industry, an important step consists in the removal of possible drug residues from the involved equipments and areas. The cleaning procedures must be validated and methods to determine trace amounts of drugs have, therefore, to be considered with special attention. An HPLC–UV method for the determination of digoxin residues on stainless steel surfaces was developed and validated in order to control a cleaning procedure. Cotton swabs, moistened with methanol were used to remove any residues of drugs from stainless steel surfaces, and give recoveries of 85.9, 85.2 and 78.7 % for three concentration levels. The precision of the results, reported as the relative standard deviation (RSD, were below 6.3 %. The method was validated over a concentration range of 0.05–12.5 µg mL-1. Low quantities of drug residues were determined by HPLC–UV using a Symmetry C18 column (150´4.6 mm, 5 µm at 20 °C with an acetonitrile–water (28:72, v/v mobile phase at a flow rate of 1.1 mL min-1, an injection volume of 100 µL and were detected at 220 nm. A simple, selective and sensitive HPLC–UV assay for the determination of digoxin residues on stainless steel was developed, validated and applied.
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Liang, Ru-Ze
2017-04-24
In this paper we study the problem of content-based image retrieval. In this problem, the most popular performance measure is the top precision measure, and the most important component of a retrieval system is the similarity function used to compare a query image against a database image. However, up to now, there is no existing similarity learning method proposed to optimize the top precision measure. To fill this gap, in this paper, we propose a novel similarity learning method to maximize the top precision measure. We model this problem as a minimization problem with an objective function as the combination of the losses of the relevant images ranked behind the top-ranked irrelevant image, and the squared Frobenius norm of the similarity function parameter. This minimization problem is solved as a quadratic programming problem. The experiments over two benchmark data sets show the advantages of the proposed method over other similarity learning methods when the top precision is used as the performance measure.
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Liang, Ru-Ze; Shi, Lihui; Wang, Haoxiang; Meng, Jiandong; Wang, Jim Jing-Yan; Sun, Qingquan; Gu, Yi
2017-01-01
In this paper we study the problem of content-based image retrieval. In this problem, the most popular performance measure is the top precision measure, and the most important component of a retrieval system is the similarity function used to compare a query image against a database image. However, up to now, there is no existing similarity learning method proposed to optimize the top precision measure. To fill this gap, in this paper, we propose a novel similarity learning method to maximize the top precision measure. We model this problem as a minimization problem with an objective function as the combination of the losses of the relevant images ranked behind the top-ranked irrelevant image, and the squared Frobenius norm of the similarity function parameter. This minimization problem is solved as a quadratic programming problem. The experiments over two benchmark data sets show the advantages of the proposed method over other similarity learning methods when the top precision is used as the performance measure.
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Hefnawy, Mohamed M; Sultan, Maha A; Al-Johar, Haya I; Kassem, Mohamed G; Aboul-Enein, Hassan Y
2012-01-01
Multiple response simultaneous optimization employing Derringer's desirability function was used for the development of a capillary electrophoresis method for the simultaneous determination of rosiglitazone (RSG) and glimepiride (GLM) in plasma and formulations. Twenty experiments, taking the two resolutions, the analysis time, and the capillary current as the responses with three important factors--buffer morality, volte and column temperature--were used to design mathematical models. The experimental responses were fitted into a second order polynomial and the six responses were simultaneously optimized to predict the optimum conditions for the effective separation of the studied compounds. The separation was carried out by using capillary zone electrophoresis (CZE) with a silica capillary column and diode array detector at 210 nm. The optimum assay conditions were 52 mmol l⁻¹ phosphate buffer, pH 7, and voltage of 22 kV at 29 °C. The method showed good agreement between the experimental data and predictive value throughout the studied parameter space. The assay limit of detection was 0.02 µg ml⁻¹ and the effective working range at relative standard deviation (RSD) of ≤ 5% was 0.05-16 µg ml⁻¹ (r = 0.999) for both drugs. Analytical recoveries of the studied drugs from spiked plasma were 97.2-101.9 ± 0.31-3.0%. The precision of the assay was satisfactory; RSD was 1.07 and 1.14 for intra- and inter-assay precision, respectively. The proposed method has a great value in routine analysis of RSG and GLM for its therapeutic monitoring and pharmacokinetic studies. Copyright © 2011 John Wiley & Sons, Ltd.
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Harrington, James M; Young, Daniel J; Essader, Amal S; Sumner, Susan J; Levine, Keith E
2014-07-01
Minerals are inorganic compounds that are essential to the support of a variety of biological functions. Understanding the range and variability of the content of these minerals in biological samples can provide insight into the relationships between mineral content and the health of individuals. In particular, abnormal mineral content may serve as an indicator of illness. The development of robust, reliable analytical methods for the determination of the mineral content of biological samples is essential to developing biological models for understanding the relationship between minerals and illnesses. This paper describes a method for the analysis of the mineral content of small volumes of serum and whole blood samples from healthy individuals. Interday and intraday precision for the mineral content of the blood (250 μL) and serum (250 μL) samples was measured for eight essential minerals--sodium (Na), calcium (Ca), magnesium (Mg), potassium (K), iron (Fe), zinc (Zn), copper (Cu), and selenium (Se)--by plasma spectrometric methods and ranged from 0.635 to 10.1% relative standard deviation (RSD) for serum and 0.348-5.98% for whole blood. A comparison of the determined ranges for ten serum samples and six whole blood samples provided good agreement with literature reference ranges. The results demonstrate that the digestion and analysis methods can be used to reliably measure the content of these minerals and potentially of other minerals.
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Kovac, Andrej; Somikova, Zuzana; Zilka, Norbert; Novak, Michal
2014-02-01
Alzheimer's disease (AD) is still being recognized today as an unmet medical need. Currently, there is no cure and early preclinical diagnostic assay available for AD. Therefore much attention is now being directed at the development of novel methods for quantitative determination of AD biomarkers in the cerebrospinal fluid (CSF). Here, we describe the liquid chromatography-tandem mass spectrometry method for determination of 5-hydroxytryptamine (SER), 5-hydroxyindoleacetic acid (5-HIAA), homovanilic acid (HVA), noradrenaline (NADR), adrenaline (ADR), dopamine (DA), glutamic acid (Glu), γ-aminobutyric acid (GABA), 3,4-dihydroxyphenylacetic acid (DOPAC) and histamine (HIS) in cerebrospinal fluid (CSF) from the rat model for human tauopathy. The benzoyl chloride was used as pre-column derivatization reagents. Neurotransmitters and metabolites were analysed on ultra performance liquid chromatography (UPLC) on C18 column in combination with tandem mass spectrometry. The method is simple, highly sensitive and showed excellent linearity with regression coefficients higher than 0.99. The accuracy was in a range of 93-113% for all analytes. The inter-day precision (n=5 days), expressed as %RSD, was in a range 2-10% for all analytes. Using this method we detected significant changes of CSF levels of two important neurotransmitters/metabolites, ADR and 5-HIAA, which correlates with progression of neurodegeneration in our animal model. © 2013 Published by Elsevier B.V.
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Energy Technology Data Exchange (ETDEWEB)
Hight, Susan C. [Elemental Research Branch, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, 5100 Paint Branch Parkway, College Park, MD 20740-3835 (United States)]. E-mail: susan.hight@fda.gov; Cheng, John [Elemental Research Branch, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, 5100 Paint Branch Parkway, College Park, MD 20740-3835 (United States)]. E-mail: john.cheng@fda.gov
2006-05-17
A method was developed for determination of methylmercury and estimation of total mercury in seafood. Mercury (Hg) compounds were extracted from 0.5 g edible seafood or 0.2 g lyophilized reference material by adding 50 ml aqueous 1% w/v L-cysteine.HCl.H{sub 2}O and heating 120 min at 60 deg. C in glass vials. Hg compounds in 50 {mu}l of filtered extract were separated by reversed-phase high performance liquid chromatography using a C-18 column and aqueous 0.1% w/v L-cysteine.HCl.H{sub 2}O + 0.1% w/v L-cysteine mobile phase at room temperature and were detected by inductively coupled plasma-mass spectrometry at mass-to-charge ratio 202. Total Hg was calculated as the mathematical sum of methyl and inorganic Hg determined in extracts. For seafoods containing 0.055-2.78 mg kg{sup -1} methylmercury and 0.014-0.137 mg kg{sup -1} inorganic Hg, precision of analyses was {<=}5% relative standard deviation (R.S.D.) for methylmercury and {<=}9% R.S.D. for inorganic Hg. Recovery of added analyte was 94% for methylmercury and 98% for inorganic Hg. Methyl and total Hg results for reference materials agreed with certified values. Limits of quantitation were 0.007 mg kg{sup -1} methylmercury and 0.005 mg kg{sup -1} inorganic Hg in edible seafood and 0.017 mg kg{sup -1} methylmercury and 0.012 mg kg{sup -1} inorganic Hg in lyophilized reference materials. Evaluation of analyte stability demonstrated that L-cysteine both stabilized and de-alkylated methylmercury, depending on holding time and cysteine concentration. Polypropylene adversely affected methylmercury stability. Total Hg results determined by this method were equivalent to results determined independently by cold vapour-atomic absorption spectrometry. Methylmercury was the predominant form of Hg in finfish. Ratios of methylmercury/total Hg determined by this method were 93-98% for finfish and 38-48% for mollusks.
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International Nuclear Information System (INIS)
Kazi, A.A.; Mumtaz, A.; Sabri, M.U.
2008-01-01
A simple and sensitive method is described for the determination of bus pirone hydrochloride in bulk drug and in formulations employing spectrophotometric technique. The method is based on the interaction orbuspirone hydrochloride with ammonium molybdate in acidic media and the absorbance is measured at 700 nm. Beer's Law is obeyed in the range of 5 macro g to 350 micro g/ml and RSD is 0.96% for buspirone hydrochloride. Analytical data for the determination of pure compound is presented along with the application of the proposed method for the analysis of pharmaceutical formulation. (author)
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Energy Technology Data Exchange (ETDEWEB)
Zucchini, Ricardo R.; Hinata, Patricia [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil); Gioseffi, Carla S.; Franco, Joao B.S. [Instituto Brasileiro de Petroleo, Gas e Biocombustiveis (IBP), Rio de Janeiro, RJ (Brazil); Nascimento, Cristina R.; Torres, Eduardo S. [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Rio de Janeiro, RJ (Brazil)
2008-07-01
The determination of repeatability and reproducibility standard deviations of an analytical method, s{sub r} and s{sub R}, obtained by Interlaboratory program, makes it possible to calculate many kinds of precision limits of the method, which are needed in every laboratory's routine result comparisons and also in between-laboratories comparisons. This paper presents the results of the first interlaboratory trial, accomplished in the Brazilian petroleum sector, performed to define the trueness and precision of the Brazilian standard method for the determination of fuel anhydrous ethylic alcohol content in gasoline, that was performed by 34 experienced laboratories. The r and R values were 0,7 and 2,3 and main factors that would improve and optimize the method are presented. (author)
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Directory of Open Access Journals (Sweden)
Satyanshu Kumar
2013-03-01
Full Text Available Following optimization of extraction, separation and analytical conditions, a rapid, sensitive and simple reverse-phase high performance liquid chromatography-photo diode array (HPLC-PDA method has been developed for the identification and quantification of wedelolactone in different extracts of Eclipta alba. The separation of wedelolactone was achieved on a C18 column using the solvent system consisting of a mixture of methanol: water: acetic acid (95: 5: 0.04 as a mobile phase in isocratic elution mode followed by photo diode array detection at 352 nm. The developed method was validated as per the guidelines of the International Conference on Harmonization (ICH. Calibration curve presented good linear regression (r²>0.998 within the test range and the maximum relative standard deviation (RSD, % values for intra-day assay were found to be 0.15, 1.30 and 1.1 for low (5 µg/mL, medium (20 µg/mL and high (80 µg/mL concentrations of wedelolactone. For inter-day assay the maximum RSD (% values were found to be 2.83, 1.51 and 2.06 for low, medium and high concentrations, respectively. Limit of detection (LOD and limit of quantification (LOQ were calculated to be 2 and 5 µg/mL respectively. Analytical recovery of wedelolactone was greater than 95%. Wedelolactone in different extracts of Eclipta alba was identified and quantified using the developed HPLC method. The validated HPLC method allowed precise quantitative analysis of wedelolactone in Eclipta. alba extracts.Desenvolveu-se método rápido, sensível e simples de Cromatografia Líquida de Alta Eficiência em fase reversa, utilizando-se arranjo de fotodiodo (HPLC-PDA, visando à separação, extração e às condições analíticas para a identificação e quantificação de wedelolactona em diferentes extratos de Eclipta alba. A separação de wedelolactona foi efetuada por meio de uma coluna C18, utilizando mistura de metanol:água:ácido acético (95:5:0.04 como fase móvel, em sistema de
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Artificial intelligence, physiological genomics, and precision medicine.
Williams, Anna Marie; Liu, Yong; Regner, Kevin R; Jotterand, Fabrice; Liu, Pengyuan; Liang, Mingyu
2018-04-01
Big data are a major driver in the development of precision medicine. Efficient analysis methods are needed to transform big data into clinically-actionable knowledge. To accomplish this, many researchers are turning toward machine learning (ML), an approach of artificial intelligence (AI) that utilizes modern algorithms to give computers the ability to learn. Much of the effort to advance ML for precision medicine has been focused on the development and implementation of algorithms and the generation of ever larger quantities of genomic sequence data and electronic health records. However, relevance and accuracy of the data are as important as quantity of data in the advancement of ML for precision medicine. For common diseases, physiological genomic readouts in disease-applicable tissues may be an effective surrogate to measure the effect of genetic and environmental factors and their interactions that underlie disease development and progression. Disease-applicable tissue may be difficult to obtain, but there are important exceptions such as kidney needle biopsy specimens. As AI continues to advance, new analytical approaches, including those that go beyond data correlation, need to be developed and ethical issues of AI need to be addressed. Physiological genomic readouts in disease-relevant tissues, combined with advanced AI, can be a powerful approach for precision medicine for common diseases.
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Development of High Precision Tsunami Runup Calculation Method Coupled with Structure Analysis
Arikawa, Taro; Seki, Katsumi; Chida, Yu; Takagawa, Tomohiro; Shimosako, Kenichiro
2017-04-01
The 2011 Great East Japan Earthquake (GEJE) has shown that tsunami disasters are not limited to inundation damage in a specified region, but may destroy a wide area, causing a major disaster. Evaluating standing land structures and damage to them requires highly precise evaluation of three-dimensional fluid motion - an expensive process. Our research goals were thus to develop a coupling STOC-CADMAS (Arikawa and Tomita, 2016) coupling with the structure analysis (Arikawa et. al., 2009) to efficiently calculate all stages from tsunami source to runup including the deformation of structures and to verify their applicability. We also investigated the stability of breakwaters at Kamaishi Bay. Fig. 1 shows the whole of this calculation system. The STOC-ML simulator approximates pressure by hydrostatic pressure and calculates the wave profiles based on an equation of continuity, thereby lowering calculation cost, primarily calculating from a e epi center to the shallow region. As a simulator, STOC-IC solves pressure based on a Poisson equation to account for a shallower, more complex topography, but reduces computation cost slightly to calculate the area near a port by setting the water surface based on an equation of continuity. CS3D also solves a Navier-Stokes equation and sets the water surface by VOF to deal with the runup area, with its complex surfaces of overflows and bores. STR solves the structure analysis including the geo analysis based on the Biot's formula. By coupling these, it efficiently calculates the tsunami profile from the propagation to the inundation. The numerical results compared with the physical experiments done by Arikawa et. al.,2012. It was good agreement with the experimental ones. Finally, the system applied to the local situation at Kamaishi bay. The almost breakwaters were washed away, whose situation was similar to the damage at Kamaishi bay. REFERENCES T. Arikawa and T. Tomita (2016): "Development of High Precision Tsunami Runup
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Chau, Hong Thi Cam; Kadokami, Kiwao; Ifuku, Tomomi; Yoshida, Yusuke
2017-12-01
A comprehensive screening method for 311 organic compounds with a wide range of physicochemical properties (log Pow -2.2-8.53) in water samples was developed by combining solid-phase extraction with liquid chromatography-high-resolution time-of-flight mass spectrometry. Method optimization using 128 pesticides revealed that tandem extraction with styrene-divinylbenzene polymer and activated carbon solid-phase extraction cartridges at pH 7.0 was optimal. The developed screening method was able to extract 190 model compounds with average recovery of 80.8% and average relative standard deviations (RSD) of 13.5% from spiked reagent water at 0.20 μg L -1 , and 87.1% recovery and 10.8% RSD at 0.05 μg L -1 . Spike-recovery testing (0.20 μg L -1 ) using real sewage treatment plant effluents resulted in an average recovery and average RSD of 190 model compounds of 77.4 and 13.1%, respectively. The method was applied to the influent and effluent of five sewage treatment plants in Kitakyushu, Japan, with 29 out of 311 analytes being observed at least once. The results showed that this method can screen for a large number of chemicals with a wide range of physicochemical properties quickly and at low operational cost, something that is difficult to achieve using conventional analytical methods. This method will find utility in target screening of hazardous chemicals with a high risk in environmental waters, and for confirming the safety of water after environmental incidents.
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Directory of Open Access Journals (Sweden)
Boris E. Duffau
2015-12-01
Full Text Available Context: Consumption of synthetic drugs had increased in recent years, used as a recreational drug by young people who presume that consumption of this drug is harmless for health; however clinical studies have shown that this stimulant and its metabolites are toxic. Due to these reasons, chemical analysis of this illicit drug is crucial from the points of view of occupational medicine, toxicology, and law enforcement with the aim of pursuit the traffic of illegal drug. Aims: Implement and fully validate a rapid and simple method for detection and quantitation of MDMA by High-Performance Thin Layer Chromatography in seized samples. Methods: With the implemented method was analyzed 12 positive samples seized by Chilean police, to found the concentration of MDMA in ecstasy tablets. Results: The method was fully validated, the linearity of the method was evaluated by the calibration curve between 51.0 – 510.0 µg/band (R2 0.9977; limit of detection was 12.1 µg per band, and limit of quantitation was 36.8 µg per band. The precision of the method (RSD was lower than 5.0%. Accuracy was evaluated by determination of the percentage of MDMA recovered by the assay (99.13%, and relative Uncertainty was 6.66%. With this method, it was analyzed real seized samples of MDMA, results showed that all samples contained MDMA and concentration was between 18.15 – 59.84 % w/w. Conclusions: The method is selective, sensitive, and specific, with possible application in forensic analysis. To the best of our knowledge, this is the first report about concentration of MDMA in ecstasy pills in Chile.
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Distributed Control Architectures for Precision Spacecraft Formations, Phase I
National Aeronautics and Space Administration — LaunchPoint Technologies, Inc. (LaunchPoint) proposes to develop synthesis methods and design architectures for distributed control systems in precision spacecraft...
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Precise shape reconstruction by active pattern in total-internal-reflection-based tactile sensor.
Saga, Satoshi; Taira, Ryosuke; Deguchi, Koichiro
2014-03-01
We are developing a total-internal-reflection-based tactile sensor in which the shape is reconstructed using an optical reflection. This sensor consists of silicone rubber, an image pattern, and a camera. It reconstructs the shape of the sensor surface from an image of a pattern reflected at the inner sensor surface by total internal reflection. In this study, we propose precise real-time reconstruction by employing an optimization method. Furthermore, we propose to use active patterns. Deformation of the reflection image causes reconstruction errors. By controlling the image pattern, the sensor reconstructs the surface deformation more precisely. We implement the proposed optimization and active-pattern-based reconstruction methods in a reflection-based tactile sensor, and perform reconstruction experiments using the system. A precise deformation experiment confirms the linearity and precision of the reconstruction.
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Precision grinding of microarray lens molding die with 4-axes controlled microwheel
Directory of Open Access Journals (Sweden)
Yuji Yamamoto, Hirofumi Suzuki, Takashi Onishi1, Tadashi Okino and Toshimichi Moriwaki
2007-01-01
Full Text Available This paper deals with precision grinding of microarray lens (fly eye molding die by using a resinoid bonded diamond wheel. An ultra-precision grinding system of microarray lens molding die and new truing method of resinoid bonded diamond wheel were developed. In this system, a grinding wheel was four-dimensionally controlled with 1 nm resolution by linear scale feedback system and scanned on the workpiece surface. New truing method by using a vanadium alloy tool was developed and its performance was obtained with high preciseness and low wheel wear. Finally, the microarray lens molding dies of fine grain tungsten carbide (WC was tested with the resinoid bonded diamond wheel to evaluate grinding performance.
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Fiber Scrambling for High Precision Spectrographs
Kaplan, Zachary; Spronck, J. F. P.; Fischer, D.
2011-05-01
The detection of Earth-like exoplanets with the radial velocity method requires extreme Doppler precision and long-term stability in order to measure tiny reflex velocities in the host star. Recent planet searches have led to the detection of so called "super-Earths” (up to a few Earth masses) that induce radial velocity changes of about 1 m/s. However, the detection of true Earth analogs requires a precision of 10 cm/s. One of the largest factors limiting Doppler precision is variation in the Point Spread Function (PSF) from observation to observation due to changes in the illumination of the slit and spectrograph optics. Thus, this stability has become a focus of current instrumentation work. Fiber optics have been used since the 1980's to couple telescopes to high-precision spectrographs, initially for simpler mechanical design and control. However, fiber optics are also naturally efficient scramblers. Scrambling refers to a fiber's ability to produce an output beam independent of input. Our research is focused on characterizing the scrambling properties of several types of fibers, including circular, square and octagonal fibers. By measuring the intensity distribution after the fiber as a function of input beam position, we can simulate guiding errors that occur at an observatory. Through this, we can determine which fibers produce the most uniform outputs for the severest guiding errors, improving the PSF and allowing sub-m/s precision. However, extensive testing of fibers of supposedly identical core diameter, length and shape from the same manufacturer has revealed the "personality” of individual fibers. Personality describes differing intensity patterns for supposedly duplicate fibers illuminated identically. Here, we present our results on scrambling characterization as a function of fiber type, while studying individual fiber personality.
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[Precision and personalized medicine].
Sipka, Sándor
2016-10-01
The author describes the concept of "personalized medicine" and the newly introduced "precision medicine". "Precision medicine" applies the terms of "phenotype", "endotype" and "biomarker" in order to characterize more precisely the various diseases. Using "biomarkers" the homogeneous type of a disease (a "phenotype") can be divided into subgroups called "endotypes" requiring different forms of treatment and financing. The good results of "precision medicine" have become especially apparent in relation with allergic and autoimmune diseases. The application of this new way of thinking is going to be necessary in Hungary, too, in the near future for participants, controllers and financing boards of healthcare. Orv. Hetil., 2016, 157(44), 1739-1741.
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Influence of Waveform Characteristics on LiDAR Ranging Accuracy and Precision
Yang, Bingwei; Xie, Xinhao; Li, Duan
2018-01-01
Time of flight (TOF) based light detection and ranging (LiDAR) is a technology for calculating distance between start/stop signals of time of flight. In lab-built LiDAR, two ranging systems for measuring flying time between start/stop signals include time-to-digital converter (TDC) that counts time between trigger signals and analog-to-digital converter (ADC) that processes the sampled start/stop pulses waveform for time estimation. We study the influence of waveform characteristics on range accuracy and precision of two kinds of ranging system. Comparing waveform based ranging (WR) with analog discrete return system based ranging (AR), a peak detection method (WR-PK) shows the best ranging performance because of less execution time, high ranging accuracy, and stable precision. Based on a novel statistic mathematical method maximal information coefficient (MIC), WR-PK precision has a high linear relationship with the received pulse width standard deviation. Thus keeping the received pulse width of measuring a constant distance as stable as possible can improve ranging precision. PMID:29642639
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Influence of Waveform Characteristics on LiDAR Ranging Accuracy and Precision
Directory of Open Access Journals (Sweden)
Xiaolu Li
2018-04-01
Full Text Available Time of flight (TOF based light detection and ranging (LiDAR is a technology for calculating distance between start/stop signals of time of flight. In lab-built LiDAR, two ranging systems for measuring flying time between start/stop signals include time-to-digital converter (TDC that counts time between trigger signals and analog-to-digital converter (ADC that processes the sampled start/stop pulses waveform for time estimation. We study the influence of waveform characteristics on range accuracy and precision of two kinds of ranging system. Comparing waveform based ranging (WR with analog discrete return system based ranging (AR, a peak detection method (WR-PK shows the best ranging performance because of less execution time, high ranging accuracy, and stable precision. Based on a novel statistic mathematical method maximal information coefficient (MIC, WR-PK precision has a high linear relationship with the received pulse width standard deviation. Thus keeping the received pulse width of measuring a constant distance as stable as possible can improve ranging precision.
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Towards an Open Software Platform for Field Robots in Precision Agriculture
Directory of Open Access Journals (Sweden)
Kjeld Jensen
2014-06-01
Full Text Available Robotics in precision agriculture has the potential to improve competitiveness and increase sustainability compared to current crop production methods and has become an increasingly active area of research. Tractor guidance systems for supervised navigation and implement control have reached the market, and prototypes of field robots performing precision agriculture tasks without human intervention also exist. But research in advanced cognitive perception and behaviour that is required to enable a more efficient, reliable and safe autonomy becomes increasingly demanding due to the growing software complexity. A lack of collaboration between research groups contributes to the problem. Scientific publications describe methods and results from the work, but little field robot software is released and documented for others to use. We hypothesize that a common open software platform tailored to field robots in precision agriculture will significantly decrease development time and resources required to perform experiments due to efficient reuse of existing work across projects and robot platforms. In this work we present the FroboMind software platform and evaluate the performance when applied to precision agriculture tasks.
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The Lanczos and Conjugate Gradient Algorithms in Finite Precision Arithmetic
Czech Academy of Sciences Publication Activity Database
Meurant, G.; Strakoš, Zdeněk
2006-01-01
Roč. 15, - (2006), s. 471-542 ISSN 0962-4929 R&D Projects: GA AV ČR 1ET400300415 Institutional research plan: CEZ:AV0Z10300504 Keywords : Lanczos method * conjugate gradient method * finite precision arithmetic * numerical stability * iterative methods Subject RIV: BA - General Mathematics
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Determination of amphotericin B in PLA-PEG blend nanoparticles by HPLC-PDA
Directory of Open Access Journals (Sweden)
Caroline Danziato Rodrigues
2014-12-01
Full Text Available In this work, we developed and validated an effective reversed-phase HPLC method with photodiode array (PDA detection for the quantitative analysis of amphotericin B (AmB in poly(lactide-poly(ethylene glycol (PLA-PEG blend nanoparticles. Chromatographic runs were performed on a reverse phase C18 column using a mobile phase comprising a 9% acetic acid and acetonitrile mixture (40:60, v/v under isocratic elution with a flow rate of 1 mL/min. AmB was detected at a wavelength of 408 nm. The validation process was performed considering the selectivity, linearity, precision, accuracy, robustness, limit of detection (LOD and limit of quantitation (LOQ of the method. A concentration range of 1-20 µg/mL was used to construct a linear calibration curve. The LOQ and LOD were 55 and 18 ng/mL, respectively. The mean recovery of AmB from the samples was 99.92% (relative standard deviation (RSD = 0.34%, n=9, and the method was robust for changes in the flow rate of the mobile phase (maximum RSD=4.82%. The intra- and inter-assay coefficients of variation were less than 0.59%. The method was successfully used to determine the entrapment efficiency of AmB in PLA-PEG blend nanoparticles.
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The newest precision measurement
International Nuclear Information System (INIS)
Lee, Jing Gu; Lee, Jong Dae
1974-05-01
This book introduces basic of precision measurement, measurement of length, limit gauge, measurement of angles, measurement of surface roughness, measurement of shapes and locations, measurement of outline, measurement of external and internal thread, gear testing, accuracy inspection of machine tools, three dimension coordinate measuring machine, digitalisation of precision measurement, automation of precision measurement, measurement of cutting tools, measurement using laser, and point of choosing length measuring instrument.
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Yang, X; Yang, Y; Zhou, R; Bian, L
2001-11-01
For studying the contents of dietary fiber in general foods and functional foods, a enzymatic-gravimetric method recommended by AOAC was established in our laboratory. The method for the determination of total, soluble and insoluble dietary fiber in foods and functional foods could be used for many other kind of foods. The relative standard deviations (RSD) of reproducibility between-run and within-run were 2.04%-7.85%, 3.42%-55.23% respectively. The repeatability of the methods was good, and the methods are suitable for many foods.
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Chellini, Paula R; Lages, Eduardo B; Franco, Pedro H C; Nogueira, Fernando H A; César, Isabela C; Pianetti, Gerson A
2015-01-01
Tuberculosis treatment consists of a fixed dose combination of rifampicin (RIF), isoniazid (INH), pyrazinamide (PYZ), and ethambutol hydrochloride (EMB). The combined treatment using various drugs is necessary for patient curing, without recrudescence, and for prevention of drug-resistant mutants, which may occur during treatment. An HPLC-diode array detector (DAD) method for the simultaneous determination of RIF, INH, PYZ, and EMB in fixed dose combination tablets was developed and validated. Chromatographic experiments were performed on an Agilent 1200 HPLC system, and the separation was carried out on a Purospher STAR RP18e (250×4.6 mm id, 5 μm, Merck) analytical column. Gradient elution was carried out with a mobile phase of 20 mM monobasic sodium phosphate buffer with 0.2% triethylamine (pH 7.0) and acetonitrile at a flow rate of 1.5 mL/min. The total run time was 12 min, and the re-equilibration time was 5 min. EMB detection was performed at 210 nm, and RIF, INH, and PYZ were detected at 238 nm, using a DAD. The method proved to be specific, linear (r2>0.99), precise (RSD<2%), accurate, and robust and may be applied to the QC analysis of pharmaceutical formulations.
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Enabling Precision Cardiology Through Multiscale Biology and Systems Medicine
Directory of Open Access Journals (Sweden)
Kipp W. Johnson, BS
2017-06-01
Full Text Available Summary: The traditional paradigm of cardiovascular disease research derives insight from large-scale, broadly inclusive clinical studies of well-characterized pathologies. These insights are then put into practice according to standardized clinical guidelines. However, stagnation in the development of new cardiovascular therapies and variability in therapeutic response implies that this paradigm is insufficient for reducing the cardiovascular disease burden. In this state-of-the-art review, we examine 3 interconnected ideas we put forth as key concepts for enabling a transition to precision cardiology: 1 precision characterization of cardiovascular disease with machine learning methods; 2 the application of network models of disease to embrace disease complexity; and 3 using insights from the previous 2 ideas to enable pharmacology and polypharmacology systems for more precise drug-to-patient matching and patient-disease stratification. We conclude by exploring the challenges of applying a precision approach to cardiology, which arise from a deficit of the required resources and infrastructure, and emerging evidence for the clinical effectiveness of this nascent approach. Key Words: cardiology, clinical informatics, multi-omics, precision medicine, translational bioinformatics
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Fast and sensitive detection of indels induced by precise gene targeting
DEFF Research Database (Denmark)
Yang, Zhang; Steentoft, Catharina; Hauge, Camilla
2015-01-01
The nuclease-based gene editing tools are rapidly transforming capabilities for altering the genome of cells and organisms with great precision and in high throughput studies. A major limitation in application of precise gene editing lies in lack of sensitive and fast methods to detect...... and characterize the induced DNA changes. Precise gene editing induces double-stranded DNA breaks that are repaired by error-prone non-homologous end joining leading to introduction of insertions and deletions (indels) at the target site. These indels are often small and difficult and laborious to detect...
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Kozlik, Petr; Tircova, Barbora
2016-11-01
Counterfeit steroids are available on the black market, ultimately to consumers who believe they are buying a legitimate pharmaceutical item from the labeled company. In many cases, counterfeit steroids can contain lower doses or some products can be overdosed. This can unwittingly expose users to a significant health risks. The mixture of testosterone propionate, phenylpropionate, isocaproate and decanoate in an oil-based injectable dosage form belongs to the one of the most misused illicit drugs by a variety of athletes. This study developed a new, fast, simple and reliable HPLC method combined with a simple sample preparation step to determine testosterone propionate, phenylpropionate, isocaproate and decanoate in an oil-based injectable dosage form without the use of sophisticated and expensive instrumentation. The developed analytical procedure provides high throughput of samples where LC analysis takes only 6min and sample preparation of oil matrix in one step takes approximately 10min with precision ranging from 1.03 to 3.38% (RSD), and accuracy (relative error %) within ±2.01%. This method was found to be precise, linear, accurate, sensitive, selective and robust for routine application in screening of commercial pharmaceutical products based on content of mentioned testosterone esters in their oil-based injectable dosage form for counterfeit drugs. This method was successfully applied to the analysis of nine samples of commercial testosterone mixtures purchased from various sources and will be further used as an effective screening method for determination of previously mentioned testosterone esters in samples confiscated by Institute of Forensic Science (Slovakia) during the illegal trade. Copyright © 2016 Elsevier Inc. All rights reserved.
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International Nuclear Information System (INIS)
Madrakian, Tayyebeh; Zolfigol, Mohammad Ali; Solgi, Mohammad
2008-01-01
A method was proposed for the preconcentration of some transition elements at trace levels using a column packed with silica gel modified by a synthetic ligand. Metal ions were adsorbed on 2,4,6-trimorpholino-1,3,5-triazin modified silica gel, then analytes retained on the adsorbent were eluted by 1 mol L -1 hydrochloric acid and determined by flame atomic absorption spectrometry (FAAS). The influences of some experimental parameters including pH of the sample solution, weight of adsorbent, type, concentration and volume of eluent, flow rates of the sample solution and eluent, and sample volume on the preconcentration efficiency have been investigated. The influences of some matrix elements were also examined. The method also was used for simultaneous preconcentration of these elements and the method was successfully applied to the preconcentration and determination of them. The detection limits of the method for Ni 2+ , Co 2+ , Cd 2+ and Zn 2+ were 0.29, 0.20, 0.23 and, 0.30 ng mL -1 , respectively. The application of this modified silica gel to preconcentration of investigated cation from tap water, lake water, urine and apple leaves gave high accuracy and precision (relative standard deviation (R.S.D.) <3%)
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Goloshchapov, D.; Seredin, P.; Minakov, D.; Domashevskaya, E.
2018-02-01
This paper deals with the luminescence characteristics of an analogue of the mineral component of dental enamel of the nanocrystalline B-type carbonate-substituted hydroxyapatite (CHAP) with 3D defects (i.e. nanopores of ∼2-5 nm) on the nanocrystalline surface. The laser-induced luminescence of the synthesized CHAP samples was in the range of ∼515 nm (∼2.4 eV) and is due to CO3 groups replacing the PO4 group. It was found that the intensity of the luminescence of the CHAP is caused by structurally incorporated CO3 groups in the HAP structure. Furthermore, the intensity of the luminescence also decreases as the number of the above intracentre defects (CO3) in the apatite structure declines. These results are potentially promising for developing the foundations for precise methods for the early detection of caries in human solid dental tissue.
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Dick, Lawrence W; Mehl, John T; Loughney, John W; Mach, Anna; Rustandi, Richard R; Ha, Sha; Zhang, Lan; Przysiecki, Craig T; Dieter, Lance; Hoang, Van M
2015-01-01
The development of a multivalent outer membrane vesicle (OMV) vaccine where each strain contributes multiple key protein antigens presents numerous analytical challenges. One major difficulty is the ability to accurately and specifically quantitate each antigen, especially during early development and process optimization when immunoreagents are limited or unavailable. To overcome this problem, quantitative mass spectrometry methods can be used. In place of traditional mass assays such as enzyme-linked immunosorbent assays (ELISAs), quantitative LC-MS/MS using multiple reaction monitoring (MRM) can be used during early-phase process development to measure key protein components in complex vaccines in the absence of specific immunoreagents. Multiplexed, label-free quantitative mass spectrometry methods using protein extraction by either detergent or 2-phase solvent were developed to quantitate levels of several meningococcal serogroup B protein antigens in an OMV vaccine candidate. Precision was demonstrated to be less than 15% RSD for the 2-phase extraction and less than 10% RSD for the detergent extraction method. Accuracy was 70 to 130% for the method using a 2-phase extraction and 90-110% for detergent extraction. The viability of MS-based protein quantification as a vaccine characterization method was demonstrated and advantages over traditional quantitative methods were evaluated. Implementation of these MS-based quantification methods can help to decrease the development time for complex vaccines and can provide orthogonal confirmation of results from existing antigen quantification techniques.
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Cramer, Emily
2016-01-01
Abstract Hospital performance reports often include rankings of unit pressure ulcer rates. Differentiating among units on the basis of quality requires reliable measurement. Our objectives were to describe and apply methods for assessing reliability of hospital‐acquired pressure ulcer rates and evaluate a standard signal‐noise reliability measure as an indicator of precision of differentiation among units. Quarterly pressure ulcer data from 8,199 critical care, step‐down, medical, surgical, and medical‐surgical nursing units from 1,299 US hospitals were analyzed. Using beta‐binomial models, we estimated between‐unit variability (signal) and within‐unit variability (noise) in annual unit pressure ulcer rates. Signal‐noise reliability was computed as the ratio of between‐unit variability to the total of between‐ and within‐unit variability. To assess precision of differentiation among units based on ranked pressure ulcer rates, we simulated data to estimate the probabilities of a unit's observed pressure ulcer rate rank in a given sample falling within five and ten percentiles of its true rank, and the probabilities of units with ulcer rates in the highest quartile and highest decile being identified as such. We assessed the signal‐noise measure as an indicator of differentiation precision by computing its correlations with these probabilities. Pressure ulcer rates based on a single year of quarterly or weekly prevalence surveys were too susceptible to noise to allow for precise differentiation among units, and signal‐noise reliability was a poor indicator of precision of differentiation. To ensure precise differentiation on the basis of true differences, alternative methods of assessing reliability should be applied to measures purported to differentiate among providers or units based on quality. © 2016 The Authors. Research in Nursing & Health published by Wiley Periodicals, Inc. PMID:27223598
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Mohammad Sadegh Allahyari; Masoumeh Mohammadzadeh; Stefanos A. Nastis
2016-01-01
Identifying factors that influence the attitudes of agricultural experts regarding precision agriculture plays an important role in developing, promoting and establishing precision agriculture. The aim of this study was to identify factors affecting the attitudes of agricultural experts regarding the implementation of precision agriculture. A descriptive research design was employed as the research method. A research-made questionnaire was used to examine the agricultural experts’ attitude to...
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DEFF Research Database (Denmark)
Charoenpong, C. N.; Bristow, L. A.; Altabet, M. A.
2014-01-01
ratio mass spectrometer (IRMS). A continuous flow of He carrier gas completely degasses the sample, and passes through the preparation and purification system before entering the IRMS for analysis. The use of this continuous He carrier permits short analysis times (less than 8 min per sample......) as compared with current high-precision methods. In addition to reference gases, calibration is achieved using air-equilibrated water standards of known temperature and salinity. Assessment of reference gas injections, air equilibrated standards, as well as samples collected in the field shows the accuracy...
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High Precision Edge Detection Algorithm for Mechanical Parts
Duan, Zhenyun; Wang, Ning; Fu, Jingshun; Zhao, Wenhui; Duan, Boqiang; Zhao, Jungui
2018-04-01
High precision and high efficiency measurement is becoming an imperative requirement for a lot of mechanical parts. So in this study, a subpixel-level edge detection algorithm based on the Gaussian integral model is proposed. For this purpose, the step edge normal section line Gaussian integral model of the backlight image is constructed, combined with the point spread function and the single step model. Then gray value of discrete points on the normal section line of pixel edge is calculated by surface interpolation, and the coordinate as well as gray information affected by noise is fitted in accordance with the Gaussian integral model. Therefore, a precise location of a subpixel edge was determined by searching the mean point. Finally, a gear tooth was measured by M&M3525 gear measurement center to verify the proposed algorithm. The theoretical analysis and experimental results show that the local edge fluctuation is reduced effectively by the proposed method in comparison with the existing subpixel edge detection algorithms. The subpixel edge location accuracy and computation speed are improved. And the maximum error of gear tooth profile total deviation is 1.9 μm compared with measurement result with gear measurement center. It indicates that the method has high reliability to meet the requirement of high precision measurement.
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Arayne, M Saeed; Sultana, Najma; Tabassum, Arman
2015-02-01
An efficient, selective and cost-effective liquid chromatographic assay was developed and validated for the simultaneous quantification of ciprofloxacin and rosuvastatin in Active Pharmaceutical Ingredients (API), pharmaceutical formulations and in human serum. The chromatographic system consisted of mobile phase methanol-water, 90:10 v/v at pH 3.0 adjusted with o-phosphoric acid, pumped at 1.0 mL/min through a prepacked Purospher Star C18 (5 µm, 25 × 0.46 cm) column and effluent was monitored at the isosbestic point (255 nm) as well as at the λmax of individual drugs (243 and 271 nm). The method was validated over a linear concentration range of 0.25-15 µg/mL for ciprofloxacin and 0.33-20 µg/mL for rosuvastatin (r(2) ≥ 0.999). The ranges of reliable response (limits of detection and quantitation) for ciprofloxacin were 3-15 and 9-45 ng/mL and 17-29 and 52-88 ng/mL, respectively, for rosuvastatin in all API, pharmaceutical formulations and human serum. Analytical recovery from human serum was >98% and relative standard deviation (RSD) was <2. The accuracies were 97.13-102.55 and 97.41-101.31% and precisions in RSD were 0.04-1.90 and 0.02-1.23% for ciprofloxacin and rosuvastatin, respectively. No matrix interferences, ion suppression/enhancement and carry-over were detected. The total assay run time was less than 5 min. In another study, for optimum performance the detector was programmed for multiwavelength scanning at the absorption maxima of each component. Consequently, the linearity range was improved and limit of detection and quantitation values were down to 1-4 and 4-12 ng/mL for ciprofloxacin and 3-5 and 9-15 ng/mL for rosuvastatin, respectively. The validation parameters fitted ICH guidelines through the isosbestic and individual λmax approach. The small sample volume and simplicity of preparation make this method suitable for use in human serum samples, pharmaceutical formulations, quality control, drug
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Directory of Open Access Journals (Sweden)
Lichun Huang
2017-12-01
Full Text Available This report describes the design, development, validation and long-term performance of tPA clot lysis activity assay using Advanced Chemistry Line Total Operational Performance (ACL TOP⢠Homeostasis Testing System. The results of the study demonstrated robust and stable performance of the analytical method. The accuracy of the assay, expressed by percent recovery is 98â99%. The intermediate precision and repeatability precision, expressed as Relative Standard Deviation (RSD, was 3% and less than 2% respectively. The validated range is from 70% to 130% of the target potency of 5.8 Ã 105 IU/mg. The linearity of this range, expressed in correlation coefficient, is 0.997. After the assay is transferred to a QC laboratory, the assay retained high accuracy and precision with a success rate of >99%. Keywords: Potency assay, Clot lysis, Comparability, Automation
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Precision medicine: opportunities, possibilities, and challenges for patients and providers.
Adams, Samantha A; Petersen, Carolyn
2016-07-01
Precision medicine approaches disease treatment and prevention by taking patients' individual variability in genes, environment, and lifestyle into account. Although the ideas underlying precision medicine are not new, opportunities for its more widespread use in practice have been enhanced by the development of large-scale databases, new methods for categorizing and representing patients, and computational tools for analyzing large datasets. New research methods may create uncertainty for both healthcare professionals and patients. In such situations, frameworks that address ethical, legal, and social challenges can be instrumental for facilitating trust between patients and providers, but must protect patients while not stifling progress or overburdening healthcare professionals. In this perspective, we outline several ethical, legal, and social issues related to the Precision Medicine Initiative's proposed changes to current institutions, values, and frameworks. This piece is not an exhaustive overview, but is intended to highlight areas meriting further study and action, so that precision medicine's goal of facilitating systematic learning and research at the point of care does not overshadow healthcare's goal of providing care to patients. © The Author 2016. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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Dong, Shiqi; Zeng, Yong; Wei, Guangli; Si, Duanyun; Liu, Changxiao
2018-03-01
A simple, sensitive and selective LC-MS/MS method for quantitative analysis of human insulin was developed and validated in dog plasma. Insulin glargine was used as the internal standard. After a simple step of solid-phase extraction, the chromatographic separation of human insulin was achieved by using InertSustain Bio C18 column with a mobile phase of acetonitrile containing 1% formic acid (A)-water containing 1% formic acid (B). The detection was performed by positive ion electrospray ionization in multiple-reaction monitoring (MRM) mode. Good linearity was observed in the concentration range of 1-1000 μIU/mL (r 2 > 0.99), and the lower limit of quantification was 1 μIU/mL (equal to 38.46 pg/mL). The intra- and inter-day precision (expressed as relative standard deviation, RSD) of human insulin were ≤12.1% and ≤13.0%, respectively, and the accuracy (expressed as relative error, RE) was in the range of -7.23-11.9%. The recovery and matrix effect were both within acceptable limits. This method was successfully applied for the pharmacokinetic study of human insulin in dogs after subcutaneous administration. Copyright © 2018 Elsevier B.V. All rights reserved.
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Precision Medicine in Cardiovascular Diseases
Directory of Open Access Journals (Sweden)
Yan Liu
2017-02-01
Full Text Available Since President Obama announced the Precision Medicine Initiative in the United States, more and more attention has been paid to precision medicine. However, clinicians have already used it to treat conditions such as cancer. Many cardiovascular diseases have a familial presentation, and genetic variants are associated with the prevention, diagnosis, and treatment of cardiovascular diseases, which are the basis for providing precise care to patients with cardiovascular diseases. Large-scale cohorts and multiomics are critical components of precision medicine. Here we summarize the application of precision medicine to cardiovascular diseases based on cohort and omic studies, and hope to elicit discussion about future health care.
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Budget impact and cost-effectiveness: can we afford precision medicine in oncology?
Doble, Brett
2016-01-01
Over the past decade there have been remarkable advancements in the understanding of the molecular underpinnings of malignancy. Methods of testing capable of elucidating patients' molecular profiles are now readily available and there is an increased desire to incorporate the information derived from such tests into treatment selection for cancer patients. This has led to more appropriate application of existing treatments as well as the development of a number of innovative and highly effective treatments or what is known collectively as precision medicine. The impact that precision medicine will have on health outcomes is uncertain, as are the costs it will incur. There is, therefore, a need to develop economic evidence and appropriate methods of evaluation to support its implementation to ensure the resources allocated to these approaches are affordable and offer value for money. The market for precision medicine in oncology continues to rapidly expand, placing an increased pressure on reimbursement decision-makers to consider the value and opportunity cost of funding such approaches to care. The benefits of molecular testing can be complex and difficult to evaluate given currently available economic methods, potentially causing a distorted appreciation of their value. Funding decisions of precision medicine will also have far-reaching implications, requiring the consideration of both patient and public perspectives in decision-making. Recommendations to improve the value proposition of precision medicine are, therefore, provided with the hopes of facilitating a better understanding of its impact on outcomes and the overall health budget.
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Precision production: enabling deterministic throughput for precision aspheres with MRF
Maloney, Chris; Entezarian, Navid; Dumas, Paul
2017-10-01
Aspherical lenses offer advantages over spherical optics by improving image quality or reducing the number of elements necessary in an optical system. Aspheres are no longer being used exclusively by high-end optical systems but are now replacing spherical optics in many applications. The need for a method of production-manufacturing of precision aspheres has emerged and is part of the reason that the optics industry is shifting away from artisan-based techniques towards more deterministic methods. Not only does Magnetorheological Finishing (MRF) empower deterministic figure correction for the most demanding aspheres but it also enables deterministic and efficient throughput for series production of aspheres. The Q-flex MRF platform is designed to support batch production in a simple and user friendly manner. Thorlabs routinely utilizes the advancements of this platform and has provided results from using MRF to finish a batch of aspheres as a case study. We have developed an analysis notebook to evaluate necessary specifications for implementing quality control metrics. MRF brings confidence to optical manufacturing by ensuring high throughput for batch processing of aspheres.
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Shang, Xiaohong; Zhao, Yunfeng; Zhang, Lei; Li, Xiaowei; Wu, Yongning
2011-07-01
The improvement method was developed for methylmercury determination using liquid chromatography online coupled with cold vapor atomic fluorescence spectrometry (LC-CV-AFS). Cysteine was used as complexing agent in mobile phase instead of mercaptoethanol. Under the optimized conditions, baseline separation of mercury species could be achieved within 8 min on a C18 column with a mobile phase of 5% (v/v) acetonitrile-1 g/L L-cysteine-50 mmol/L ammonium acetate aqueous solution. The linear range of calibration curve of methylmercury was 1-50 microg/L and the limit of detection (S/N = 3) for methylmercury was 0.3 microg/L. Ultrasonication assisted hydrochloric acid extraction was used to extract methylmercury from seafood samples. The sample extract was cleaned up by a C18 solid phase extraction (SPE) cartridge. For validation of the method, certified reference materials and spiked seafood samples were analyzed. The determined methylmercury contents of certified reference materials NIST1566b, BCR464 and GBW10029 agreed well with the certified values. The determined methylmercury values for Food Analysis Performance Assessment Scheme (FAPAS) sample 07115 were satisfied. The recoveries of methylmercury in seafood samples at three spiked levels (10, 50 and 500 microg/kg) ranged from 89% to 112%, including cooked seafood food. The precision of the method based on relative standard deviation (RSD) was not more than 7%. The present method of LC-CV-AFS is accurate, sensitive, simple, and can meet the demand of methylmercury determination in seafood.
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Rapid Quantification of N-Methyl-2-pyrrolidone in Polymer Matrices by Thermal Desorption-GC/MS.
Kim, Young-Min; Kim, Jae Woo; Moon, Hye Mi; Lee, Min-Jin; Hosaka, Akihiko; Watanabe, Atsushi; Teramae, Norio; Park, Young-Kwon; Myung, Seung-Woon
2017-01-01
Analysis of a residual solvent in polymeric materials has become an important issue due to the increased regulations and standards for its use. N-Methyl-2-pyrrolidone (NMP) is a solvent widely used in many industries and restricted as one of the chemicals under EU REACH regulations due to its potential harmful effects. In this study, thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) is applied for the quantitative analysis of NMP with the use of a polymer-coated sample cup. By using the polymer-coated sample cup, the vaporization of NMP was prevented during waiting time before TD-GC/MS analysis. The calibration curve for the TD method showed good linearity (correlation coefficient, r 2 = 0.9998) and precision values (below 5.3% RSD). NMP recovery rates in different polymer matrices (PS, PMMA and PVC) were in the range of 98.8 to 106.6% with RSD values below 5.0%. The quantification result (600 mg NMP/kg PVC) for the blind NMP carrying sample in a PVC matrix by TD-GC/MS was higher than that (532 mg NMP/kg PVC) by solvent extraction-GC/MS method.
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Directory of Open Access Journals (Sweden)
Liu Yang
2018-03-01
Full Text Available An accurate and reliable method using ultra-high performance liquid chromatography combined with triple quadrupole tandem mass spectrometry (UHPLC–MS/MS was established for simultaneous quantification of five major bioactive analytes in raw, wine-processed, and salt-processed Radix Achyranthis bidentatae (RAB. The results showed that this method exhibited desirable sensitivity, precision, stability, and repeatability. The overall intra-day and inter-day variations (RSD were in the range of 1.57–2.46 and 1.51–3.00%, respectively. The overall recoveries were 98.58–101.48% with a relative standard deviation (RSD of 0.01–1.86%. In addition, the developed approach was applied to 21 batches of raw, wine-processed, and salt-processed samples of RAB. Hierarchical clustering analysis (HCA, principal component analysis (PCA, heat map, and boxplot analysis were performed to evaluate the quality of raw, wine-processed, and salt-processed RAB collected from different regions. The chemometrics combined with the quantitative analysis based on UHPLC–MS/MS results indicated that the content of five analytes increased significantly in processed RAB compared to raw RAB.
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Contacting nanowires and nanotubes with atomic precision for electronic transport
Qin, Shengyong; Hellstrom, Sondra; Bao, Zhenan; Boyanov, Boyan; Li, An-Ping
2012-01-01
Making contacts to nanostructures with atomic precision is an important process in the bottom-up fabrication and characterization of electronic nanodevices. Existing contacting techniques use top-down lithography and chemical etching, but lack atomic precision and introduce the possibility of contamination. Here, we report that a field-induced emission process can be used to make local contacts onto individual nanowires and nanotubes with atomic spatial precision. The gold nano-islands are deposited onto nanostructures precisely by using a scanning tunneling microscope tip, which provides a clean and controllable method to ensure both electrically conductive and mechanically reliable contacts. To demonstrate the wide applicability of the technique, nano-contacts are fabricated on silicide atomic wires, carbon nanotubes, and copper nanowires. The electrical transport measurements are performed in situ by utilizing the nanocontacts to bridge the nanostructures to the transport probes. © 2012 American Institute of Physics.
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Precise positional measurement system in transcranial magnetic stimulation
International Nuclear Information System (INIS)
Inoue, Tomonori; Mishima, Yukuo; Hiwaki, Osamu
2006-01-01
Transcranial magnetic stimulation (TMS) is a method for noninvasive stimulation of cerebral cortex, and it has contributed to clinical and basic researches of brain function. In order to estimate the accurate stimulating points of the cortex in TMS, precise measurement of the subject's head and the stimulating coil is necessary. In this study, we have developed the positioning TMS system with a three-dimensional (3-D) digitizer and a multi-articular system. We proposed a method for the accurate measurement of a subject's head and cortex, in which the location data of the subject's face surface captured by a 3-D digitizer were superimposed on the magnetic resonance imaging (MRI) data of the subject's face surface. Using this system, the precise estimation of the stimulated sites of the cortex in TMS was achieved. The validity of the system was verified by the experiment on the TMS of the motor cortex. (author)
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Kurdi, Said El; Muaileq, Dina Abu; Alhazmi, Hassan A; Bratty, Mohammed Al; Deeb, Sami El
2017-06-27
HPLC stationary phases of monolithic and fused core type can be used to achieve fast chromatographic separation as an alternative to UPLC. In this study, monolithic and fused core stationary phases are compared for fast separation of four fat-soluble vitamins. Three new methods on the first and second generation monolithic silica RP-18e columns and a fused core pentafluoro-phenyl propyl column were developed. Application of three fused core columns offered comparable separations of retinyl palmitate, DL-α-tocopheryl acetate, cholecalciferol and menadione in terms of elution speed and separation efficiency. Separation was achieved in approx. 5 min with good resolution (Rs > 5) and precision (RSD ≤ 0.6 %). Monolithic columns showed, however, a higher number of theoretical plates, better precision and lower column backpressure than the fused core column. The three developed methods were successfully applied to separate and quantitate fat-soluble vitamins in commercial products.
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Platinum clusters with precise numbers of atoms for preparative-scale catalysis.
Imaoka, Takane; Akanuma, Yuki; Haruta, Naoki; Tsuchiya, Shogo; Ishihara, Kentaro; Okayasu, Takeshi; Chun, Wang-Jae; Takahashi, Masaki; Yamamoto, Kimihisa
2017-09-25
Subnanometer noble metal clusters have enormous potential, mainly for catalytic applications. Because a difference of only one atom may cause significant changes in their reactivity, a preparation method with atomic-level precision is essential. Although such a precision with enough scalability has been achieved by gas-phase synthesis, large-scale preparation is still at the frontier, hampering practical applications. We now show the atom-precise and fully scalable synthesis of platinum clusters on a milligram scale from tiara-like platinum complexes with various ring numbers (n = 5-13). Low-temperature calcination of the complexes on a carbon support under hydrogen stream affords monodispersed platinum clusters, whose atomicity is equivalent to that of the precursor complex. One of the clusters (Pt 10 ) exhibits high catalytic activity in the hydrogenation of styrene compared to that of the other clusters. This method opens an avenue for the application of these clusters to preparative-scale catalysis.The catalytic activity of a noble metal nanocluster is tied to its atomicity. Here, the authors report an atom-precise, fully scalable synthesis of platinum clusters from molecular ring precursors, and show that a variation of only one atom can dramatically change a cluster's reactivity.
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International Nuclear Information System (INIS)
Kozak, J.; Gutowski, J.; Kozak, M.; Wieczorek, M.; Koscielniak, P.
2010-01-01
The method exploits the possibilities of flow injection gradient titration in a system of reversed flow with spectrophotometric detection. In the developed approach a small amount of titrant (EDTA) is injected into a stream of sample containing a mixture of indicators (sulfosalicylic acid and 1,10-phenanthroline). In acid environment sulfosalicylic acid forms a complex with Fe(III), whereas 1,10-phenanthroline forms a complex with Fe(II). Measurements are performed at wavelength λ = 530 nm when radiation is absorbed by both complexes. After injection EDTA replaces sulfosalicylic acid and forms with Fe(III) more stable colourless complex. As a result, a characteristic 'cut off' peak is registered with a width corresponding to the Fe(III) concentration and with a height corresponding to the Fe(II) concentration. Calibration was performed by titration of four two-component standard solutions of the Fe(II)/Fe(III) concentrations established in accordance with 2 2 factorial plan. The method was tested with the use of synthetic samples and then it was applied to the analysis of water samples taken from artesian wells. Under optimized experimental conditions Fe(II) and Fe(III) were determined with precision less than 0.8 and 2.5% (RSD) and accuracy less than 3.2 and 5.1% (relative error) within the concentration ranges of 0.1-3.0 and 0.9-3.5 mg L -1 of both analytes, respectively.
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Guescini, Michele; Sisti, Davide; Rocchi, Marco B L; Panebianco, Renato; Tibollo, Pasquale; Stocchi, Vilberto
2013-01-01
Quantitative real-time PCR represents a highly sensitive and powerful technology for the quantification of DNA. Although real-time PCR is well accepted as the gold standard in nucleic acid quantification, there is a largely unexplored area of experimental conditions that limit the application of the Ct method. As an alternative, our research team has recently proposed the Cy0 method, which can compensate for small amplification variations among the samples being compared. However, when there is a marked decrease in amplification efficiency, the Cy0 is impaired, hence determining reaction efficiency is essential to achieve a reliable quantification. The proposed improvement in Cy0 is based on the use of the kinetic parameters calculated in the curve inflection point to compensate for efficiency variations. Three experimental models were used: inhibition of primer extension, non-optimal primer annealing and a very small biological sample. In all these models, the improved Cy0 method increased quantification accuracy up to about 500% without affecting precision. Furthermore, the stability of this procedure was enhanced integrating it with the SOD method. In short, the improved Cy0 method represents a simple yet powerful approach for reliable DNA quantification even in the presence of marked efficiency variations.
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[Extraction and content determination of polysaccharides in Viscum coloratum].
Wang, Jun; Zhu, Yi-fan
2007-11-01
To establish a method for extraction and content determination of polysaccharide in Viscum coloratum. Polysaccharide was extracted by hot water, separated by ultrafiltration and ion-exchange chromatography. The content determination was performed at wavelength 490 nm with phenol-sulfuric acid as a chtomo-genic agent. The content of polyaccharide in V. coloratum, CVPS-III, and CVPS-III-C were respectively 4.93% (RSD 1.04%, n = 3), 43.28% (RSD 1.39%, n =3), 69.55% (RSD 1.62%, n = 3), and the average recovery was 96.07% (RSD 2.54%, n = 5). The method was simple, rapid, and accurate.
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Satpathy, Gouri; Tyagi, Yogesh Kumar; Gupta, Rajinder Kumar
2011-08-01
A rapid, effective and ecofriendly method for sensitive screening and quantification of 72 pesticides residue in fruits and vegetables, by microwave-assisted extraction (MAE) followed by dispersive solid-phase extraction (d-SPE), retention time locked (RTL) capillary gas-chromatographic separation in trace ion mode mass spectrometric determination has been validated as per ISO/IEC: 17025:2005. Identification and reporting with total and extracted ion chromatograms were facilitated to a great extent by Deconvolution reporting software (DRS). For all compounds LOD were 0.002-0.02mg/kg and LOQ were 0.025-0.100mg/kg. Correlation coefficients of the calibration curves in the range of 0.025-0.50mg/kg were >0.993. To validate matrix effects repeatability, reproducibility, recovery and overall uncertainty were calculated for the 35 matrices at 0.025, 0.050 and 0.100mg/kg. Recovery ranged between 72% and 114% with RSD of <20% for repeatability and intermediate precision. The reproducibility of the method was evaluated by an inter laboratory participation and Z score obtained within ±2. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Fast and Precise Beam Energy Measurement using Compton Backscattering at e+e- Colliders
Kaminskiy, V V; Muchnoi, N Yu; Zhilich, V N
2017-01-01
The report describes a method for a fast and precise beam energy measurement in the beam energy range 0.5-2 GeV and its application at various e+e- colliders. Low-energy laser photons interact head-on with the electron or positron beam and produce Compton backscattered photons whose energy is precisely measured by HPGe detector. The method allows measuring the beam energy with relative accuracy of ∼2-5.10-5. The method was successfully applied at VEPP-4M, VEPP-3, VEPP-2000 (BINP, Russia) and BEPC-II (IHEP, China).
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Russo, Russell R; Burn, Matthew B; Ismaily, Sabir K; Gerrie, Brayden J; Han, Shuyang; Alexander, Jerry; Lenherr, Christopher; Noble, Philip C; Harris, Joshua D; McCulloch, Patrick C
2018-03-01
Accurate measurements of shoulder and elbow motion are required for the management of musculoskeletal pathology. The purpose of this investigation was to compare three techniques for measuring motion. The authors hypothesized that digital photography would be equivalent in accuracy and show higher precision compared to the other two techniques. Using infrared motion capture analysis as the reference standard, shoulder flexion/abduction/internal rotation/external rotation and elbow flexion/extension were measured using visual estimation, goniometry, and digital photography on 10 fresh frozen cadavers. These measurements were performed by three physical therapists and three orthopaedic surgeons. Accuracy was defined by the difference from the reference standard (motion capture analysis), while precision was defined by the proportion of measurements within the authors' definition of clinical significance (10° for all motions except for elbow extension where 5° was used). Analysis of variance (ANOVA), t-tests, and chi-squared tests were used. Although statistically significant differences were found in measurement accuracy between the three techniques, none of these differences met the authors' definition of clinical significance. Precision of the measurements was significantly higher for both digital photography (shoulder abduction [93% vs. 74%, p < 0.001], shoulder internal rotation [97% vs. 83%, p = 0.001], and elbow flexion [93% vs. 65%, p < 0.001]) and goniometry (shoulder abduction [92% vs. 74%, p < 0.001] and shoulder internal rotation [94% vs. 83%, p = 0.008]) than visual estimation. Digital photography was more precise than goniometry for measurements of elbow flexion only [93% vs. 76%, p < 0.001]. There was no clinically significant difference in measurement accuracy between the three techniques for shoulder and elbow motion. Digital photography showed higher measurement precision compared to visual estimation for shoulder abduction, shoulder
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Precision evaluation of dual X-ray absorptiometry (iDXA) measurements
International Nuclear Information System (INIS)
Yu Wei; Lin Qiang; Yu Xiaobo; Yao Jinpeng
2009-01-01
Objective: To evaluate the precision of the iDXA measurements for lumbar spine, proximal femur and whole body bone density as well as body composition (lean and fat). Methods: The study recruited randomly 30 volunteers. Each subject was scanned by iDXA twice in the same day. Measurement sites included lumbar spine, proximal femur and whole body. Precision errors were expressed as root mean square of CV (RMS-CV). Results: Mean precision errors of bone density measurements at lumbar spine, femoral neck, Ward's triangle, great trochanter and total femur ranged from 0.8% to 2.0%, with the lowest of 0.8% at both lumbar spine and total femur, as well as with the highest of 2.0% at ward' s triangle; Mean precision errors of bone density measurements at whole body and its individual site ranged from 0.7% to 2.0%, with the lowest of 0.7% for the whole body measurement, mean precision errors of lean measurements at whole body and its individual site ranged from 0.6% to 2.1%, with the lowest of 0.6% for the whole body lean measurement; Mean precision errors of fat measurements at whole body and its individual site ranged from 1.0% to 3.2%, with the lowest of 1.0% for the whole body fat measurement. Conclusion: Measurement precision of iDXA at lumbar spine, proximal femur and whole body bone density could meet clinical needs; Precision values of the measurements of whole body and its individual composition may be helpful for future clinical use. (authors)
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Usefulness of Models in Precision Nutrient Management
DEFF Research Database (Denmark)
Plauborg, Finn; Manevski, Kiril; Zhenjiang, Zhou
Modern agriculture increasingly applies new methods and technologies to increase production and nutrient use efficiencies and at the same time reduce leaching of nutrients and greenhouse gas emissions. GPS based ECa-measurement equipment, ER or EM instrumentations, are used to spatially character......Modern agriculture increasingly applies new methods and technologies to increase production and nutrient use efficiencies and at the same time reduce leaching of nutrients and greenhouse gas emissions. GPS based ECa-measurement equipment, ER or EM instrumentations, are used to spatially...... and mineral composition. Mapping of crop status and the spatial-temporal variability within fields with red-infrared reflection are used to support decision on split fertilisation and more precise dosing. The interpretation and use of these various data in precise nutrient management is not straightforward...... of mineralisation. However, whether the crop would benefit from this depended to a large extent on soil hydraulic conductivity within the range of natural variation when testing the model. In addition the initialisation of the distribution of soil total carbon and nitrogen into conceptual model compartments...
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Precision Airdrop (Largage de precision)
2005-12-01
NAVIGATION TO A PRECISION AIRDROP OVERVIEW RTO-AG-300-V24 2 - 9 the point from various compass headings. As the tests are conducted, the resultant...rate. This approach avoids including a magnetic compass for the heading reference, which has difficulties due to local changes in the magnetic field...Scientifica della Difesa ROYAUME-UNI Via XX Settembre 123 Dstl Knowledge Services ESPAGNE 00187 Roma Information Centre, Building 247 SDG TECEN / DGAM
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Loss-induced limits to phase measurement precision with maximally entangled states
International Nuclear Information System (INIS)
Rubin, Mark A.; Kaushik, Sumanth
2007-01-01
The presence of loss limits the precision of an approach to phase measurement using maximally entangled states, also referred to as NOON states. A calculation using a simple beam-splitter model of loss shows that, for all nonzero values L of the loss, phase measurement precision degrades with increasing number N of entangled photons for N sufficiently large. For L above a critical value of approximately 0.785, phase measurement precision degrades with increasing N for all values of N. For L near zero, phase measurement precision improves with increasing N down to a limiting precision of approximately 1.018L radians, attained at N approximately equal to 2.218/L, and degrades as N increases beyond this value. Phase measurement precision with multiple measurements and a fixed total number of photons N T is also examined. For L above a critical value of approximately 0.586, the ratio of phase measurement precision attainable with NOON states to that attainable by conventional methods using unentangled coherent states degrades with increasing N, the number of entangled photons employed in a single measurement, for all values of N. For L near zero this ratio is optimized by using approximately N=1.279/L entangled photons in each measurement, yielding a precision of approximately 1.340√(L/N T ) radians