Development, description and validation of a Tritium Environmental Release Model (TERM).

Science.gov (United States)

Jeffers, Rebecca S; Parker, Geoffrey T

2014-01-01

Tritium is a radioisotope of hydrogen that exists naturally in the environment and may also be released through anthropogenic activities. It bonds readily with hydrogen and oxygen atoms to form tritiated water, which then cycles through the hydrosphere. This paper seeks to model the migration of tritiated species throughout the environment - including atmospheric, river and coastal systems - more comprehensively and more consistently across release scenarios than is currently in the literature. A review of the features and underlying conceptual models of some existing tritium release models was conducted, and an underlying aggregated conceptual process model defined, which is presented. The new model, dubbed 'Tritium Environmental Release Model' (TERM), was then tested against multiple validation sets from literature, including experimental data and reference tests for tritium models. TERM has been shown to be capable of providing reasonable results which are broadly comparable with atmospheric HTO release models from the literature, spanning both continuous and discrete release conditions. TERM also performed well when compared with atmospheric data. TERM is believed to be a useful tool for examining discrete and continuous atmospheric releases or combinations thereof. TERM also includes further capabilities (e.g. river and coastal release scenarios) that may be applicable to certain scenarios that atmospheric models alone may not handle well. Copyright © 2013 Elsevier Ltd. All rights reserved.

Magnetic Decoupling Design and Experimental Validation of a Radial-Radial Flux Compound-Structure Permanent-Magnet Synchronous Machine for HEVs

Directory of Open Access Journals (Sweden)

Zhiyi Song

2012-10-01

Full Text Available The radial-radial flux compound-structure permanent-magnet synchronous machine (CS-PMSM, integrated by two concentrically arranged permanent-magnet electric machines, is an electromagnetic power-splitting device for hybrid electric vehicles (HEVs. As the two electric machines share a rotor as structural and magnetic common part, their magnetic paths are coupled, leading to possible mutual magnetic-field interference and complex control. In this paper, a design method to ensure magnetic decoupling with minimum yoke thickness of the common rotor is investigated. A prototype machine is designed based on the proposed method, and the feasibility of magnetic decoupling and independent control is validated by experimental tests of mutual influence. The CS-PMSM is tested by a designed driving cycle, and functions to act as starter motor, generator and to help the internal combustion engine (ICE operate at optimum efficiency are validated.

LES Modeling with Experimental Validation of a Compound Channel having Converging Floodplain

Science.gov (United States)

Mohanta, Abinash; Patra, K. C.

2018-04-01

Computational fluid dynamics (CFD) is often used to predict flow structures in developing areas of a flow field for the determination of velocity field, pressure, shear stresses, effect of turbulence and others. A two phase three-dimensional CFD model along with the large eddy simulation (LES) model is used to solve the turbulence equation. This study aims to validate CFD simulations of free surface flow or open channel flow by using volume of fluid method by comparing the data observed in hydraulics laboratory of the National Institute of Technology, Rourkela. The finite volume method with a dynamic sub grid scale was carried out for a constant aspect ratio and convergence condition. The results show that the secondary flow and centrifugal force influence flow pattern and show good agreement with experimental data. Within this paper over-bank flows have been numerically simulated using LES in order to predict accurate open channel flow behavior. The LES results are shown to accurately predict the flow features, specifically the distribution of secondary circulations both for in-bank channels as well as over-bank channels at varying depth and width ratios in symmetrically converging flood plain compound sections.

Tank waste source term inventory validation. Volume 1. Letter report

International Nuclear Information System (INIS)

Brevick, C.H.; Gaddis, L.A.; Johnson, E.D.

1995-01-01

The sample data for selection of 11 radionuclides and 24 chemical analytes were extracted from six separate sample data sets, were arranged in a tabular format and were plotted on scatter plots for all of the 149 single-shell tanks, the 24 double-shell tanks and the four aging waste tanks. The solid and liquid sample data was placed in separate tables and plots. The sample data and plots were compiled from the following data sets: characterization raw sample data, recent core samples, D. Braun data base, Wastren (Van Vleet) data base, TRAC and HTCE inventories. This document is Volume I of the Letter Report entitled Tank Waste Source Term Inventory Validation

MeSH key terms for validation and annotation of gene expression clusters

Energy Technology Data Exchange (ETDEWEB)

Rechtsteiner, A. (Andreas); Rocha, L. M. (Luis Mateus)

2004-01-01

Integration of different sources of information is a great challenge for the analysis of gene expression data, and for the field of Functional Genomics in general. As the availability of numerical data from high-throughput methods increases, so does the need for technologies that assist in the validation and evaluation of the biological significance of results extracted from these data. In mRNA assaying with microarrays, for example, numerical analysis often attempts to identify clusters of co-expressed genes. The important task to find the biological significance of the results and validate them has so far mostly fallen to the biological expert who had to perform this task manually. One of the most promising avenues to develop automated and integrative technology for such tasks lies in the application of modern Information Retrieval (IR) and Knowledge Management (KM) algorithms to databases with biomedical publications and data. Examples of databases available for the field are bibliographic databases c ntaining scientific publications (e.g. MEDLINE/PUBMED), databases containing sequence data (e.g. GenBank) and databases of semantic annotations (e.g. the Gene Ontology Consortium and Medical Subject Headings (MeSH)). We present here an approach that uses the MeSH terms and their concept hierarchies to validate and obtain functional information for gene expression clusters. The controlled and hierarchical MeSH vocabulary is used by the National Library of Medicine (NLM) to index all the articles cited in MEDLINE. Such indexing with a controlled vocabulary eliminates some of the ambiguity due to polysemy (terms that have multiple meanings) and synonymy (multiple terms have similar meaning) that would be encountered if terms would be extracted directly from the articles due to differing article contexts or author preferences and background. Further, the hierarchical organization of the MeSH terms can illustrate the conceptuallfunctional relationships of genes

Validation of MIMGO: a method to identify differentially expressed GO terms in a microarray dataset

Directory of Open Access Journals (Sweden)

Yamada Yoichi

2012-12-01

Full Text Available Abstract Background We previously proposed an algorithm for the identification of GO terms that commonly annotate genes whose expression is upregulated or downregulated in some microarray data compared with in other microarray data. We call these “differentially expressed GO terms” and have named the algorithm “matrix-assisted identification method of differentially expressed GO terms” (MIMGO. MIMGO can also identify microarray data in which genes annotated with a differentially expressed GO term are upregulated or downregulated. However, MIMGO has not yet been validated on a real microarray dataset using all available GO terms. Findings We combined Gene Set Enrichment Analysis (GSEA with MIMGO to identify differentially expressed GO terms in a yeast cell cycle microarray dataset. GSEA followed by MIMGO (GSEA + MIMGO correctly identified (p Conclusions MIMGO is a reliable method to identify differentially expressed GO terms comprehensively.

Tank waste source term inventory validation. Volume II. Letter report

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-04-01

This document comprises Volume II of the Letter Report entitled Tank Waste Source Term Inventory Validation. This volume contains Appendix C, Radionuclide Tables, and Appendix D, Chemical Analyte Tables. The sample data for selection of 11 radionuclides and 24 chemical analytes were extracted from six separate sample data sets, were arranged in a tabular format and were plotted on scatter plots for all of the 149 single-shell tanks, the 24 double-shell tanks and the four aging waste tanks. The solid and liquid sample data was placed in separate tables and plots. The sample data and plots were compiled from the following data sets: characterization raw sample data, recent core samples, D. Braun data base, Wastren (Van Vleet) data base, TRAC and HTCE inventories.

Tank waste source term inventory validation. Volume II. Letter report

International Nuclear Information System (INIS)

1995-04-01

This document comprises Volume II of the Letter Report entitled Tank Waste Source Term Inventory Validation. This volume contains Appendix C, Radionuclide Tables, and Appendix D, Chemical Analyte Tables. The sample data for selection of 11 radionuclides and 24 chemical analytes were extracted from six separate sample data sets, were arranged in a tabular format and were plotted on scatter plots for all of the 149 single-shell tanks, the 24 double-shell tanks and the four aging waste tanks. The solid and liquid sample data was placed in separate tables and plots. The sample data and plots were compiled from the following data sets: characterization raw sample data, recent core samples, D. Braun data base, Wastren (Van Vleet) data base, TRAC and HTCE inventories

Modeling long-term uptake and re-volatilization of semi-volatile organic compounds (SVOCs) across the soil-atmosphere interface.

Science.gov (United States)

Bao, Zhongwen; Haberer, Christina; Maier, Uli; Beckingham, Barbara; Amos, Richard T; Grathwohl, Peter

2015-12-15

Soil-atmosphere exchange is important for the environmental fate and atmospheric transport of many semi-volatile organic compounds (SVOCs). This study focuses on modeling the vapor phase exchange of semi-volatile hydrophobic organic pollutants between soil and the atmosphere using the multicomponent reactive transport code MIN3P. MIN3P is typically applied to simulate aqueous and vapor phase transport and reaction processes in the subsurface. We extended the code to also include an atmospheric boundary layer where eddy diffusion takes place. The relevant processes and parameters affecting soil-atmosphere exchange were investigated in several 1-D model scenarios and at various time scales (from years to centuries). Phenanthrene was chosen as a model compound, but results apply for other hydrophobic organic compounds as well. Gaseous phenanthrene was assumed to be constantly supplied to the system during a pollution period and a subsequent regulation period (with a 50% decline in the emission rate). Our results indicate that long-term soil-atmosphere exchange of phenanthrene is controlled by the soil compartment - re-volatilization thus depends on soil properties. A sensitivity analysis showed that accumulation and transport in soils in the short term is dominated by diffusion, whereas in the long term groundwater recharge and biodegradation become relevant. As expected, sorption causes retardation and slows down transport and biodegradation. If atmospheric concentration is reduced (e.g. after environmental regulations), re-volatilization from soil to the atmosphere occurs only for a relatively short time period. Therefore, the model results demonstrate that soils generally are sinks for atmospheric pollutants. The atmospheric boundary layer is only relevant for time scales of less than one month. The extended MIN3P code can also be applied to simulate fluctuating concentrations in the atmosphere, for instance due to temperature changes in the topsoil. Copyright �

Assessment of a recombinant androgen receptor binding assay: initial steps towards validation.

Science.gov (United States)

Freyberger, Alexius; Weimer, Marc; Tran, Hoai-Son; Ahr, Hans-Jürgen

2010-08-01

Despite more than a decade of research in the field of endocrine active compounds with affinity for the androgen receptor (AR), still no validated recombinant AR binding assay is available, although recombinant AR can be obtained from several sources. With funding from the European Union (EU)-sponsored 6th framework project, ReProTect, we developed a model protocol for such an assay based on a simple AR binding assay recently developed at our institution. Important features of the protocol were the use of a rat recombinant fusion protein to thioredoxin containing both the hinge region and ligand binding domain (LBD) of the rat AR (which is identical to the human AR-LBD) and performance in a 96-well plate format. Besides two reference compounds [dihydrotestosterone (DHT), androstenedione] ten test compounds with different affinities for the AR [levonorgestrel, progesterone, prochloraz, 17alpha-methyltestosterone, flutamide, norethynodrel, o,p'-DDT, dibutylphthalate, vinclozolin, linuron] were used to explore the performance of the assay. At least three independent experiments per compound were performed. The AR binding properties of reference and test compounds were well detected, in terms of the relative ranking of binding affinities, there was good agreement with published data obtained from experiments using recombinant AR preparations. Irrespective of the chemical nature of the compound, individual IC(50)-values for a given compound varied by not more than a factor of 2.6. Our data demonstrate that the assay reliably ranked compounds with strong, weak, and no/marginal affinity for the AR with high accuracy. It avoids the manipulation and use of animals, as a recombinant protein is used and thus contributes to the 3R concept. On the whole, this assay is a promising candidate for further validation. Copyright 2009 Elsevier Inc. All rights reserved.

Analytical method development and validation for quantification of uranium in compounds of the nuclear fuel cycle by Fourier Transform Infrared (FTIR) Spectroscopy

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)

HPLC Quantification of Cytotoxic Compounds from Aspergillus niger

Directory of Open Access Journals (Sweden)

Paula Karina S. Uchoa

2017-01-01

Full Text Available A high-performance liquid chromatography method was developed and validated for the quantification of the cytotoxic compounds produced by a marine strain of Aspergillus niger. The fungus was grown in malt peptone dextrose (MPD, potato dextrose yeast (PDY, and mannitol peptone yeast (MnPY media during 7, 14, 21, and 28 days, and the natural products were identified by standard compounds. The validation parameters obtained were selectivity, linearity (coefficient of correlation > 0.99, precision (relative standard deviation below 5%, and accuracy (recovery > 96.

Review of the status of validation of the computer codes used in the severe accident source term reassessment study (BMI-2104)

International Nuclear Information System (INIS)

Kress, T.S.

1985-04-01

The determination of severe accident source terms must, by necessity it seems, rely heavily on the use of complex computer codes. Source term acceptability, therefore, rests on the assessed validity of such codes. Consequently, one element of NRC's recent efforts to reassess LWR severe accident source terms is to provide a review of the status of validation of the computer codes used in the reassessment. The results of this review is the subject of this document. The separate review documents compiled in this report were used as a resource along with the results of the BMI-2104 study by BCL and the QUEST study by SNL to arrive at a more-or-less independent appraisal of the status of source term modeling at this time

Optimization and validation of an existing, surgical and robust dry eye rat model for the evaluation of therapeutic compounds.

Science.gov (United States)

Joossen, Cedric; Lanckacker, Ellen; Zakaria, Nadia; Koppen, Carina; Joossens, Jurgen; Cools, Nathalie; De Meester, Ingrid; Lambeir, Anne-Marie; Delputte, Peter; Maes, Louis; Cos, Paul

2016-05-01

The aim of this research was to optimize and validate an animal model for dry eye, adopting clinically relevant evaluation parameters. Dry eye was induced in female Wistar rats by surgical removal of the exorbital lacrimal gland. The clinical manifestations of dry eye were evaluated by tear volume measurements, corneal fluorescein staining, cytokine measurements in tear fluid, MMP-9 mRNA expression and CD3(+) cell infiltration in the conjunctiva. The animal model was validated by treatment with Restasis(®) (4 weeks) and commercial dexamethasone eye drops (2 weeks). Removal of the exorbital lacrimal gland resulted in 50% decrease in tear volume and a gradual increase in corneal fluorescein staining. Elevated levels of TNF-α and IL-1α have been registered in tear fluid together with an increase in CD3(+) cells in the palpebral conjunctiva when compared to control animals. Additionally, an increase in MMP-9 mRNA expression was recorded in conjunctival tissue. Reference treatment with Restasis(®) and dexamethasone eye drops had a positive effect on all evaluation parameters, except on tear volume. This rat dry eye model was validated extensively and judged appropriate for the evaluation of novel compounds and therapeutic preparations for dry eye disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

Energy gap formation mechanism through the interference phenomena of electrons in face-centered cubic elements and compounds with the emphasis on half-Heusler and Heusler compounds

Science.gov (United States)

Mizutani, U.; Sato, H.

2018-05-01

Many face-centred cubic elements and compounds with the number of atoms per unit cell N equal to 8, 12 and 16 are known to be stabilised by forming either a band gap or a pseudogap at the Fermi level. They are conveniently expressed as cF8, cF12 and cF16, respectively, in the Pearson symbol. From the cF8 family, we worked on three tetravalent elements C (diamond), Si and Ge, SZn-type AsGa compound and NaCl-type compounds like BiLu, AsSc, etc. From the cF12 family, more than 80 compounds were selected, with a particular emphasis on ABC- and half-Heusler-type ternary equiatomic compounds. Among cF16 compounds, both the Heusler compounds ABC2 and Zintl compounds were studied. We revealed that, regardless of whether or not the transition metal (TM) and/or rare-earth (RE) elements are involved as constituent elements, the energy gap formation mechanism for cF8, cF12 and cF16 compounds can be universally discussed in terms of interference phenomenon of itinerant electrons with set of reciprocal lattice planes with ? = 8, 11 and 12, where ? refers to square of the critical reciprocal of lattice vector of an fcc lattice. The number of itinerant electrons per unit cell, e/uc, for all these band gap/pseudogap-bearing compounds is found to fall on a universal line called "3/2-power law" when plotted against ? on a logarithmic scale. This proves the validity of the fulfilment of the interference condition ? in conformity with other pseudogap compounds with different crystal symmetries and different sizes of the unit cell reported in literature.

Analysis of volatile compounds in gluten-free bread crusts with an optimised and validated SPME-GC/QTOF methodology.

Science.gov (United States)

Pico, Joana; Antolín, Beatriz; Román, Laura; Gómez, Manuel; Bernal, José

2018-04-01

The aroma of bread crust, as one of the first characteristics perceived, is essential for bread acceptance. However, gluten-free bread crusts exhibit weak aroma. A SPME-GC/QTOF methodology was optimised with PCA and RSM and validated for the quantification of 44 volatile compounds in bread crust, extracting 0.75 g of crust at 60 °C for 51 min. LODs ranged between 3.60 and 1760 μg Kg -1 , all the R 2 were higher than 0.99 and %RSD for precision and %Er for accuracy were lower than 9% and 12%, respectively. A commercial wheat bread crust was quantified, and furfural was the most abundant compound. Bread crusts of wheat starch and of japonica rice, basmati rice and teff flours were also quantified. Teff flour and wheat starch crusts were very suitable for improving gluten-free bread crust aroma, due to their similar content in 2-acetyl-1-pyrroline and 4-hydroxy-2,5-dimethyl-3(2H)-furanone compared to wheat flour crust and also for their high content in pyrazines. Copyright © 2018 Elsevier Ltd. All rights reserved.

Explicating Validity

Science.gov (United States)

Kane, Michael T.

2016-01-01

How we choose to use a term depends on what we want to do with it. If "validity" is to be used to support a score interpretation, validation would require an analysis of the plausibility of that interpretation. If validity is to be used to support score uses, validation would require an analysis of the appropriateness of the proposed…

Free and glycosidically bound volatile compounds in sun-dried raisins made from different fragrance intensities grape varieties using a validated HS-SPME with GC-MS method.

Science.gov (United States)

Wang, Dong; Duan, Chang-Qing; Shi, Ying; Zhu, Bao-Qing; Javed, Hafiz Umer; Wang, Jun

2017-08-01

The conditions of sample pretreatments and HS-SPME for extracting volatile compounds from raisins were optimized, and the method was validated in the study. Free and glycosidically bound volatile compounds in three different fragrance intensities raisins were analysed using this method. There were 91 compounds identified, and 72, 26 and 8 of these compounds came from fresh grapes, the auto-oxidation of unsaturated fatty acids (UFAO) and the Maillard reaction, respectively. The aroma profiles of Thompson Seedless raisins (TSRs) and Centennial Seedless raisins (CSRs) were similar, while the floral, fruity, green and roasted aromas of CSRs were higher than those of TSRs due to the contributions of benzeneacetaldehyde, 2-pentylfuran, (E)-2-nonenal and 3-ethyl-2,5-dimethyl pyrazine. Decanal, rose oxide, geraniol, linalool and β-damascenone made the floral and fruity aromas of Zixiang Seedless raisins (ZSRs) greater than those in TSRs and CSRs, but the green and roasted aroma intensities of ZSRs were lower. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development and validation of a stability-indicating RP-HPLC method for assay of betamethasone and estimation of its related compounds.

Science.gov (United States)

Fu, Qiang; Shou, Minshan; Chien, Dwight; Markovich, Robert; Rustum, Abu M

2010-02-05

Betamethasone (9alpha-fluoro-16beta-methylprednisolone) is one of the members of the corticosteriod family of active pharmaceutical ingredient (API), which is widely used as an anti-inflammatory agent and also as a starting material to manufacture various esters of betamethasone. A stability-indicating reverse-phase high performance liquid chromatography (RP-HPLC) method has been developed and validated which can separate and accurately quantitate low levels of 26 betamethasone related compounds. The stability-indicating capability of the method was demonstrated through adequate separation of all potential betamethasone related compounds from betamethasone and also from each other that are present in aged and stress degraded betamethasone stability samples. Chromatographic separation of betamethasone and its related compounds was achieved by using a gradient elution at a flow rate of 1.0mL/min on a ACE 3 C18 column (150mmx4.6mm, 3microm particle size, 100A pore size) at 40 degrees C. Mobile phase A of the gradient was 0.1% methanesulfonic acid in aqueous solution and mobile phase B was a mixture of tert-butanol and 1,4-dioxane (7:93, v/v). UV detection at 254nm was employed to monitor the analytes. For betamethasone 21-aldehyde, the QL and DL were 0.02% and 0.01% respectively. For betamethasone and the rest of the betamethasone related compounds, the QL and DL were 0.05% and 0.02%. The precision of betamethasone assay is 0.6% and the accuracy of betamethasone assay ranged from 98.1% to 99.9%.

Determination of perfluorinated compounds in fish fillet homogenates: Method validation and application to fillet homogenates from the Mississippi River

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.

Determination of perfluorinated compounds in fish fillet homogenates: Method validation and application to fillet homogenates from the Mississippi River

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.

Validation: an overview of definitions

International Nuclear Information System (INIS)

Pescatore, C.

1995-01-01

The term validation is featured prominently in the literature on radioactive high-level waste disposal and is generally understood to be related to model testing using experiments. In a first class, validation is linked to the goal of predicting the physical world as faithfully as possible but is unattainable and unsuitable for setting goals for the safety analyses. In a second class, validation is associated to split-sampling or to blind-tests predictions. In the third class of definition, validation focuses on the quality of the decision-making process. Most prominent in the present review is the observed lack of use of the term validation in the field of low-level radioactive waste disposal. The continued informal use of the term validation in the field of high level wastes disposals can become cause for misperceptions and endless speculations. The paper proposes either abandoning the use of this term or agreeing to a definition which would be common to all. (J.S.). 29 refs

Falls in long-term care institutions for elderly people: protocol validation.

Science.gov (United States)

Baixinho, Cristina Rosa Soares Lavareda; Dixe, Maria Dos Anjos Coelho Rodrigues; Henriques, Maria Adriana Pereira

2017-01-01

To validate the content of a fall management risk protocol in long-term institutions for elderly people. Methodological, quanti-qualitative study using the Delphi technique. The tool, based on the literature, was sent electronically to obtain consensus among the 14 experts that meet the defined inclusion criteria. The 27 indicators of the protocol are organized in three dimensions: prepare for the institutionalization (IRA=.88); manage the risk of falls throughout the institutionalization (IRA=.9); and lead the communication and formation (IRA=1), with a CVI=.91. Two rounds were performed to get a consensus superior to 80% in every item. The values obtained in the reliability test (>0.8) show that the protocol can be used to meet the intended goal. The next step is the clinic validation of the protocol with residents of long-term care institutions for elderly people. Validar o conteúdo de um protocolo para a gestão do risco de queda em Instituições de Longa Permanência para Idosos. Estudo metodológico, de abordagem quantiqualitativa, utilizando a técnica de Delphi. O instrumento, construído com base na literatura, foi enviado por via electrónica, para obter consenso entre os 14 peritos que respeitam os critérios de inclusão definidos. Os 27 indicadores do protocolo estão organizados em três dimensões: Preparar a Institucionalização (IRA=,88); Gerir o Risco de Queda ao longo da Institucionalização (IRA=,9) e Liderar a comunicação e formação (IRA=1), com um CVI=,91. Foram efetuadas duas rodadas para se obter consenso superior a 80% em todos os itens. Os valores obtidos no teste de fidedignidade (>0,8) atestam que o protocolo pode ser utilizado para atingir o fim que se pretende. A próxima etapa é a validação clínica do protocolo com idosos residentes em Instituições de Longa Permanência para Idosos.

Rapid determination of the aromatic compounds methyl-anthranilate, 2'-aminoacetophenone and furaneol by GC-MS: Method validation and characterization of grape derivatives.

Science.gov (United States)

Prudêncio Dutra, Maria da Conceição; de Souza, Joyce Fagundes; Viana, Arão Cardoso; de Oliveira, Débora; Pereira, Giuliano Elias; Dos Santos Lima, Marcos

2018-05-01

A methodology for the rapid determination of the aromatic compounds methyl anthranilate (MA), 2'-aminoacetophenone (2-AAP) and furaneol by GC-MS was validated and used to characterize grape juice and wine elaborated with the new Brazilian grape varieties cultivated in northeastern Brazil, and Brazilian grape nectars. The method presented linearity (R 2  ˃ 0.9952), good accuracy (CV furaneol in the aroma of grape juice and wines elaborated with the new Brazilian grape varieties. Copyright © 2018 Elsevier Ltd. All rights reserved.

Identifying Human Phenotype Terms by Combining Machine Learning and Validation Rules

Directory of Open Access Journals (Sweden)

Manuel Lobo

2017-01-01

Full Text Available Named-Entity Recognition is commonly used to identify biological entities such as proteins, genes, and chemical compounds found in scientific articles. The Human Phenotype Ontology (HPO is an ontology that provides a standardized vocabulary for phenotypic abnormalities found in human diseases. This article presents the Identifying Human Phenotypes (IHP system, tuned to recognize HPO entities in unstructured text. IHP uses Stanford CoreNLP for text processing and applies Conditional Random Fields trained with a rich feature set, which includes linguistic, orthographic, morphologic, lexical, and context features created for the machine learning-based classifier. However, the main novelty of IHP is its validation step based on a set of carefully crafted manual rules, such as the negative connotation analysis, that combined with a dictionary can filter incorrectly identified entities, find missed entities, and combine adjacent entities. The performance of IHP was evaluated using the recently published HPO Gold Standardized Corpora (GSC, where the system Bio-LarK CR obtained the best F-measure of 0.56. IHP achieved an F-measure of 0.65 on the GSC. Due to inconsistencies found in the GSC, an extended version of the GSC was created, adding 881 entities and modifying 4 entities. IHP achieved an F-measure of 0.863 on the new GSC.

Implementing DBS methodology for the determination of Compound A in monkey blood: GLP method validation and investigation of the impact of blood spreading on performance.

Science.gov (United States)

Fan, Leimin; Lee, Jacob; Hall, Jeffrey; Tolentino, Edward J; Wu, Huaiqin; El-Shourbagy, Tawakol

2011-06-01

This article describes validation work for analysis of an Abbott investigational drug (Compound A) in monkey whole blood with dried blood spots (DBS). The impact of DBS spotting volume on analyte concentration was investigated. The quantitation range was between 30.5 and 10,200 ng/ml. Accuracy and precision of quality controls, linearity of calibration curves, matrix effect, selectivity, dilution, recovery and multiple stabilities were evaluated in the validation, and all demonstrated acceptable results. Incurred sample reanalysis was performed with 57 out of 58 samples having a percentage difference (versus the mean value) less than 20%. A linear relationship between the spotting volume and the spot area was drawn. The influence of spotting volume on concentration was discussed. All validation results met good laboratory practice acceptance requirements. Radial spreading of blood on DBS cards can be a factor in DBS concentrations at smaller spotting volumes.

Determination of perfluorinated compounds in fish fillet homogenates: method validation and application to fillet homogenates from the Mississippi River.

Science.gov (United States)

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.

Food applications of natural antimicrobial compounds

Science.gov (United States)

Lucera, Annalisa; Costa, Cristina; Conte, Amalia; Del Nobile, Matteo A.

2012-01-01

In agreement with the current trend of giving value to natural and renewable resources, the use of natural antimicrobial compounds, particularly in food and biomedical applications, becomes very frequent. The direct addition of natural compounds to food is the most common method of application, even if numerous efforts have been made to find alternative solutions to the aim of avoiding undesirable inactivation. Dipping, spraying, and coating treatment of food with active solutions are currently applied to product prior to packaging as valid options. The aim of the current work is to give an overview on the use of natural compounds in food sector. In particular, the review will gather numerous case-studies of meat, fish, dairy products, minimally processed fruit and vegetables, and cereal-based products where these compounds found application. PMID:23060862

Food applications of natural antimicrobial compounds.

Science.gov (United States)

Lucera, Annalisa; Costa, Cristina; Conte, Amalia; Del Nobile, Matteo A

2012-01-01

In agreement with the current trend of giving value to natural and renewable resources, the use of natural antimicrobial compounds, particularly in food and biomedical applications, becomes very frequent. The direct addition of natural compounds to food is the most common method of application, even if numerous efforts have been made to find alternative solutions to the aim of avoiding undesirable inactivation. Dipping, spraying, and coating treatment of food with active solutions are currently applied to product prior to packaging as valid options. The aim of the current work is to give an overview on the use of natural compounds in food sector. In particular, the review will gather numerous case-studies of meat, fish, dairy products, minimally processed fruit and vegetables, and cereal-based products where these compounds found application.

Food applications of natural antimicrobial compounds

Directory of Open Access Journals (Sweden)

Matteo Alessandro eDel Nobile

2012-08-01

Full Text Available In agreement with the current trend of giving value to natural and renewable resources, the use of natural antimicrobial compounds, particularly in food and biomedical applications, becomes very frequent. The direct addition of natural compounds to food is the most common method of application, even if numerous efforts have been made to find alternative solutions to the aim of avoiding undesirable inactivation. Dipping, spraying and coating treatment of food with active solutions are currently applied to product prior to packaging as valid options. The aim of the current work is to give an overview on the use of natural compounds in food sector. In particular, the review will gather numerous case-studies of meat, fish, dairy products, minimally processed fruit and vegetables and cereal-based products where these compounds found application.

Development and validation of a prediction model for long-term sickness absence based on occupational health survey variables

NARCIS (Netherlands)

Roelen, Corne; Thorsen, Sannie; Heymans, Martijn; Twisk, Jos; Bultmann, Ute; Bjorner, Jakob

2018-01-01

Purpose: The purpose of this study is to develop and validate a prediction model for identifying employees at increased risk of long-term sickness absence (LTSA), by using variables commonly measured in occupational health surveys. Materials and methods: Based on the literature, 15 predictor

Development and validation of RP-HPLC-UV/ Vis method for determination of phenolic compounds in several personal care products

International Nuclear Information System (INIS)

Mohammed Akkbik; Zaini Asim; Fasihuddin Ahmad

2011-01-01

A HPLC method with ultraviolet-visible spectrophotometry detection has been optimized and validated for the simultaneous determination of phenolic compounds, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) as antioxidants, and octyl methyl cinnamate (OMC) as UVB-filter in several personal care products. The dynamic range was between 1 to 250 mg/ L with relative standard deviation less than 0.25 %, (n=4). Limit of detection for BHA, BHT and OMC were 0.196, 0.170 and 0.478 mg/ L, respectively. While limit of quantification for BHA, BHT and OMC were 0.593, 0.515 and 1.448 mg/ L, respectively. The recovery for BHA, BHT and OMC ranged from 92.1-105.9 %, 83.2-108.9 % and 87.3-103.7 %, respectively. The concentration ranges of BHA, BHT and OMC in 12 commercial personal care samples were 0.13-4.85, 0.16-2.30 and 0.12-65.5 mg/ g, respectively. The concentrations of phenolic compounds in these personal care samples were below than maximum allowable concentration in personal care formulation for example 0.0004 - 10 mg/ g, 0.002 - 5 mg/ g and up to 100 mg/ g for BHA, BHT and OMC, respectively. (author)

Radioactive decay and labeled compounds

International Nuclear Information System (INIS)

Anon.

1991-01-01

This chapter on radioactive decay and labeled compounds has numerous intext equations and worked, sample problems. Topics covered include the following: terms and mathematics of radioactive decay; examples of calculations; graphs of decay equations; radioactivity or activity; activity measurements; activity decay; half-life determinations; labeled compounds. A 20 problem set is also included. 1 ref., 4 figs., 1 tab

Phenolic compounds in Ross Sea water

Science.gov (United States)

Zangrando, Roberta; Barbaro, Elena; Gambaro, Andrea; Barbante, Carlo; Corami, Fabiana; Kehrwald, Natalie; Capodaglio, Gabriele

2016-04-01

Phenolic compounds are semi-volatile organic compounds produced during biomass burning and lignin degradation in water. In atmospheric and paleoclimatic ice cores studies, these compounds are used as biomarkers of wood combustion and supply information on the type of combusted biomass. Phenolic compounds are therefore indicators of paleoclimatic interest. Recent studies of Antarctic aerosols highlighted that phenolic compounds in Antarctica are not exclusively attributable to biomass burning but also derive from marine sources. In order to study the marine contribution to aerosols we developed an analytical method to determine the concentration of vanillic acid, vanillin, p-coumaric acid, syringic acid, isovanillic acid, homovanillic acid, syringaldehyde, acetosyringone and acetovanillone present in dissolved and particle phases in Sea Ross waters using HPLC-MS/MS. The analytical method was validated and used to quantify phenolic compounds in 28 sea water samples collected during a 2012 Ross Sea R/V cruise. The observed compounds were vanillic acid, vanillin, acetovanillone and p-coumaric acid with concentrations in the ng/L range. Higher concentrations of analytes were present in the dissolved phase than in the particle phase. Sample concentrations were greatest in the coastal, surficial and less saline Ross Sea waters near Victoria Land.

Multi-view 3D echocardiography compounding based on feature consistency

Science.gov (United States)

Yao, Cheng; Simpson, John M.; Schaeffter, Tobias; Penney, Graeme P.

2011-09-01

Echocardiography (echo) is a widely available method to obtain images of the heart; however, echo can suffer due to the presence of artefacts, high noise and a restricted field of view. One method to overcome these limitations is to use multiple images, using the 'best' parts from each image to produce a higher quality 'compounded' image. This paper describes our compounding algorithm which specifically aims to reduce the effect of echo artefacts as well as improving the signal-to-noise ratio, contrast and extending the field of view. Our method weights image information based on a local feature coherence/consistency between all the overlapping images. Validation has been carried out using phantom, volunteer and patient datasets consisting of up to ten multi-view 3D images. Multiple sets of phantom images were acquired, some directly from the phantom surface, and others by imaging through hard and soft tissue mimicking material to degrade the image quality. Our compounding method is compared to the original, uncompounded echocardiography images, and to two basic statistical compounding methods (mean and maximum). Results show that our method is able to take a set of ten images, degraded by soft and hard tissue artefacts, and produce a compounded image of equivalent quality to images acquired directly from the phantom. Our method on phantom, volunteer and patient data achieves almost the same signal-to-noise improvement as the mean method, while simultaneously almost achieving the same contrast improvement as the maximum method. We show a statistically significant improvement in image quality by using an increased number of images (ten compared to five), and visual inspection studies by three clinicians showed very strong preference for our compounded volumes in terms of overall high image quality, large field of view, high endocardial border definition and low cavity noise.

Multi-view 3D echocardiography compounding based on feature consistency

International Nuclear Information System (INIS)

Yao Cheng; Schaeffter, Tobias; Penney, Graeme P; Simpson, John M

2011-01-01

Echocardiography (echo) is a widely available method to obtain images of the heart; however, echo can suffer due to the presence of artefacts, high noise and a restricted field of view. One method to overcome these limitations is to use multiple images, using the 'best' parts from each image to produce a higher quality 'compounded' image. This paper describes our compounding algorithm which specifically aims to reduce the effect of echo artefacts as well as improving the signal-to-noise ratio, contrast and extending the field of view. Our method weights image information based on a local feature coherence/consistency between all the overlapping images. Validation has been carried out using phantom, volunteer and patient datasets consisting of up to ten multi-view 3D images. Multiple sets of phantom images were acquired, some directly from the phantom surface, and others by imaging through hard and soft tissue mimicking material to degrade the image quality. Our compounding method is compared to the original, uncompounded echocardiography images, and to two basic statistical compounding methods (mean and maximum). Results show that our method is able to take a set of ten images, degraded by soft and hard tissue artefacts, and produce a compounded image of equivalent quality to images acquired directly from the phantom. Our method on phantom, volunteer and patient data achieves almost the same signal-to-noise improvement as the mean method, while simultaneously almost achieving the same contrast improvement as the maximum method. We show a statistically significant improvement in image quality by using an increased number of images (ten compared to five), and visual inspection studies by three clinicians showed very strong preference for our compounded volumes in terms of overall high image quality, large field of view, high endocardial border definition and low cavity noise.

Tracking 20 years of compound-to-target output from literature and patents.

Directory of Open Access Journals (Sweden)

Christopher Southan

Full Text Available The statistics of drug development output and declining yield of approved medicines has been the subject of many recent reviews. However, assessing research productivity that feeds development is more difficult. Here we utilise an extensive database of structure-activity relationships extracted from papers and patents. We have used this database to analyse published compounds cumulatively linked to nearly 4000 protein target identifiers from multiple species over the last 20 years. The compound output increases up to 2005 followed by a decline that parallels a fall in pharmaceutical patenting. Counts of protein targets have plateaued but not fallen. We extended these results by exploring compounds and targets for one large pharmaceutical company. In addition, we examined collective time course data for six individual protease targets, including average molecular weight of the compounds. We also tracked the PubMed profile of these targets to detect signals related to changes in compound output. Our results show that research compound output had decreased 35% by 2012. The major causative factor is likely to be a contraction in the global research base due to mergers and acquisitions across the pharmaceutical industry. However, this does not rule out an increasing stringency of compound quality filtration and/or patenting cost control. The number of proteins mapped to compounds on a yearly basis shows less decline, indicating the cumulative published target capacity of global research is being sustained in the region of 300 proteins for large companies. The tracking of six individual targets shows uniquely detailed patterns not discernible from cumulative snapshots. These are interpretable in terms of events related to validation and de-risking of targets that produce detectable follow-on surges in patenting. Further analysis of the type we present here can provide unique insights into the process of drug discovery based on the data it actually

Statistical Analysis and validation

NARCIS (Netherlands)

Hoefsloot, H.C.J.; Horvatovich, P.; Bischoff, R.

2013-01-01

In this chapter guidelines are given for the selection of a few biomarker candidates from a large number of compounds with a relative low number of samples. The main concepts concerning the statistical validation of the search for biomarkers are discussed. These complicated methods and concepts are

Assessment of A Simple Compound-Saving Method To Study Insecticidal Activity of Natural Extracts and Pure Compounds Against Mosquito Larvae.

Science.gov (United States)

Falkowski, Michaël; Jahn-Oyac, Arnaud; Ferrero, Emma; Issaly, Jean; Eparvier, Véronique; Girod, Romain; Rodrigues, Alice M S; Stien, Didier; Houël, Emeline; Dusfour, Isabelle

2016-12-01

Research on natural insecticides has intensified with the spread of resistance to chemicals among insects, particularly disease vectors. To evaluate compounds, the World Health Organization (WHO) has published standardized procedures. However, those may be excessively compound-consuming when it comes to assessing the activity of natural extracts and pure compounds isolated in limited amount. As part of our work on the discovery of new mosquito larvicides from Amazonian plants, we developed a compound-saving assay in 5-ml glass tubes instead of WHO larval 100-ml cups. Comparing activity of synthetic and natural chemicals validated the glass tube assay. Raw data, lethal doses that kill 50% (LD 50 ) and 90% (LD 90 ) at 24 and 48 h, were highly correlated (0.68 natural extracts and molecules, identifying active compounds using 10 times less material than in the WHO protocol.

A Comprehensive Plan for the Long-Term Calibration and Validation of Oceanic Biogeochemical Satellite Data

Science.gov (United States)

Hooker, Stanford B.; McClain, Charles R.; Mannino, Antonio

2007-01-01

The primary objective of this planning document is to establish a long-term capability and validating oceanic biogeochemical satellite data. It is a pragmatic solution to a practical problem based primarily o the lessons learned from prior satellite missions. All of the plan's elements are seen to be interdependent, so a horizontal organizational scheme is anticipated wherein the overall leadership comes from the NASA Ocean Biology and Biogeochemistry (OBB) Program Manager and the entire enterprise is split into two components of equal sature: calibration and validation plus satellite data processing. The detailed elements of the activity are based on the basic tasks of the two main components plus the current objectives of the Carbon Cycle and Ecosystems Roadmap. The former is distinguished by an internal core set of responsibilities and the latter is facilitated through an external connecting-core ring of competed or contracted activities. The core elements for the calibration and validation component include a) publish protocols and performance metrics; b) verify uncertainty budgets; c) manage the development and evaluation of instrumentation; and d) coordinate international partnerships. The core elements for the satellite data processing component are e) process and reprocess multisensor data; f) acquire, distribute, and archive data products; and g) implement new data products. Both components have shared responsibilities for initializing and temporally monitoring satellite calibration. Connecting-core elements include (but are not restricted to) atmospheric correction and characterization, standards and traceability, instrument and analysis round robins, field campaigns and vicarious calibration sites, in situ database, bio-optical algorithm (and product) validation, satellite characterization and vicarious calibration, and image processing software. The plan also includes an accountability process, creating a Calibration and Validation Team (to help manage

Occupational hygiene in terms of volatile organic compounds (VOCs) and bioaerosols at two solid waste management plants in Finland

International Nuclear Information System (INIS)

Lehtinen, Jenni; Tolvanen, Outi; Nivukoski, Ulla; Veijanen, Anja; Hänninen, Kari

2013-01-01

Highlights: ► Odorous VOCs: acetic acid, 2,3-butanedione, ethyl acetate, alpha-pinene and limonene. ► VOC concentrations did not exceed occupational exposure limit concentrations. ► 2,3-Butanedione as the health effecting compound is discussed. ► Endotoxin concentrations may cause health problems in waste treatment. - Abstract: Factors affecting occupational hygiene were measured at the solid waste transferring plant at Hyvinkää and at the optic separation plant in Hämeenlinna. Measurements consisted of volatile organic compounds (VOCs) and bioaerosols including microbes, dust and endotoxins. The most abundant compounds in both of the plants were aliphatic and aromatic hydrocarbons, esters of carboxylic acids, ketones and terpenes. In terms of odour generation, the most important emissions were acetic acid, 2,3-butanedione, ethyl acetate, alpha-pinene and limonene due to their low threshold odour concentrations. At the optic waste separation plant, limonene occurred at the highest concentration of all single compounds of identified VOCs. The concentration of any single volatile organic compound did not exceed the occupational exposure limit (OEL) concentration. However, 2,3-butanedione as a health risk compound is discussed based on recent scientific findings linking it to lung disease. Microbe and dust concentrations were low at the waste transferring plant. Only endotoxin concentrations may cause health problems; the average concentration inside the plant was 425 EU/m 3 which clearly exceeded the threshold value of 90 EU/m 3 . In the wheel loader cabin the endotoxin concentrations were below 1 EU/m 3 . High microbial and endotoxin concentrations were measured in the processing hall at the optic waste separation plant. The average concentration of endotoxins was found to be 10,980 EU/m 3 , a concentration which may cause health risks. Concentrations of viable fungi were quite high in few measurements in the control room. The most problematic factor was

Occupational hygiene in terms of volatile organic compounds (VOCs) and bioaerosols at two solid waste management plants in Finland

Energy Technology Data Exchange (ETDEWEB)

Lehtinen, Jenni, E-mail: jenni.k.lehtinen@jyu.fi [University of Jyväskylä, Department of Biological and Environmental Science, P.O. Box 35, 40014 Jyväskylä (Finland); Tolvanen, Outi; Nivukoski, Ulla; Veijanen, Anja; Hänninen, Kari [University of Jyväskylä, Department of Biological and Environmental Science, P.O. Box 35, 40014 Jyväskylä (Finland)

2013-04-15

Highlights: ► Odorous VOCs: acetic acid, 2,3-butanedione, ethyl acetate, alpha-pinene and limonene. ► VOC concentrations did not exceed occupational exposure limit concentrations. ► 2,3-Butanedione as the health effecting compound is discussed. ► Endotoxin concentrations may cause health problems in waste treatment. - Abstract: Factors affecting occupational hygiene were measured at the solid waste transferring plant at Hyvinkää and at the optic separation plant in Hämeenlinna. Measurements consisted of volatile organic compounds (VOCs) and bioaerosols including microbes, dust and endotoxins. The most abundant compounds in both of the plants were aliphatic and aromatic hydrocarbons, esters of carboxylic acids, ketones and terpenes. In terms of odour generation, the most important emissions were acetic acid, 2,3-butanedione, ethyl acetate, alpha-pinene and limonene due to their low threshold odour concentrations. At the optic waste separation plant, limonene occurred at the highest concentration of all single compounds of identified VOCs. The concentration of any single volatile organic compound did not exceed the occupational exposure limit (OEL) concentration. However, 2,3-butanedione as a health risk compound is discussed based on recent scientific findings linking it to lung disease. Microbe and dust concentrations were low at the waste transferring plant. Only endotoxin concentrations may cause health problems; the average concentration inside the plant was 425 EU/m{sup 3} which clearly exceeded the threshold value of 90 EU/m{sup 3}. In the wheel loader cabin the endotoxin concentrations were below 1 EU/m{sup 3}. High microbial and endotoxin concentrations were measured in the processing hall at the optic waste separation plant. The average concentration of endotoxins was found to be 10,980 EU/m{sup 3}, a concentration which may cause health risks. Concentrations of viable fungi were quite high in few measurements in the control room. The most

Identification of natural compound inhibitors for multidrug efflux pumps of Escherichia coli and Pseudomonas aeruginosa using in silico high-throughput virtual screening and in vitro validation.

Science.gov (United States)

Aparna, Vasudevan; Dineshkumar, Kesavan; Mohanalakshmi, Narasumani; Velmurugan, Devadasan; Hopper, Waheeta

2014-01-01

Pseudomonas aeruginosa and Escherichia coli are resistant to wide range of antibiotics rendering the treatment of infections very difficult. A main mechanism attributed to the resistance is the function of efflux pumps. MexAB-OprM and AcrAB-TolC are the tripartite efflux pump assemblies, responsible for multidrug resistance in P. aeruginosa and E. coli respectively. Substrates that are more susceptible for efflux are predicted to have a common pharmacophore feature map. In this study, a new criterion of excluding compounds with efflux substrate-like features was used, thereby refining the selection process and enriching the inhibitor identification process. An in-house database of phytochemicals was created and screened using high-throughput virtual screening against AcrB and MexB proteins and filtered by matching with the common pharmacophore models (AADHR, ADHNR, AAHNR, AADHN, AADNR, AAADN, AAADR, AAANR, AAAHN, AAADD and AAADH) generated using known efflux substrates. Phytochemical hits that matched with any one or more of the efflux substrate models were excluded from the study. Hits that do not have features similar to the efflux substrate models were docked using XP docking against the AcrB and MexB proteins. The best hits of the XP docking were validated by checkerboard synergy assay and ethidium bromide accumulation assay for their efflux inhibition potency. Lanatoside C and diadzein were filtered based on the synergistic potential and validated for their efflux inhibition potency using ethidium bromide accumulation study. These compounds exhibited the ability to increase the accumulation of ethidium bromide inside the bacterial cell as evidenced by these increase in fluorescence in the presence of the compounds. With this good correlation between in silico screening and positive efflux inhibitory activity in vitro, the two compounds, lanatoside C and diadzein could be promising efflux pump inhibitors and effective to use in combination therapy against drug

Identification of natural compound inhibitors for multidrug efflux pumps of Escherichia coli and Pseudomonas aeruginosa using in silico high-throughput virtual screening and in vitro validation.

Directory of Open Access Journals (Sweden)

Vasudevan Aparna

Full Text Available Pseudomonas aeruginosa and Escherichia coli are resistant to wide range of antibiotics rendering the treatment of infections very difficult. A main mechanism attributed to the resistance is the function of efflux pumps. MexAB-OprM and AcrAB-TolC are the tripartite efflux pump assemblies, responsible for multidrug resistance in P. aeruginosa and E. coli respectively. Substrates that are more susceptible for efflux are predicted to have a common pharmacophore feature map. In this study, a new criterion of excluding compounds with efflux substrate-like features was used, thereby refining the selection process and enriching the inhibitor identification process. An in-house database of phytochemicals was created and screened using high-throughput virtual screening against AcrB and MexB proteins and filtered by matching with the common pharmacophore models (AADHR, ADHNR, AAHNR, AADHN, AADNR, AAADN, AAADR, AAANR, AAAHN, AAADD and AAADH generated using known efflux substrates. Phytochemical hits that matched with any one or more of the efflux substrate models were excluded from the study. Hits that do not have features similar to the efflux substrate models were docked using XP docking against the AcrB and MexB proteins. The best hits of the XP docking were validated by checkerboard synergy assay and ethidium bromide accumulation assay for their efflux inhibition potency. Lanatoside C and diadzein were filtered based on the synergistic potential and validated for their efflux inhibition potency using ethidium bromide accumulation study. These compounds exhibited the ability to increase the accumulation of ethidium bromide inside the bacterial cell as evidenced by these increase in fluorescence in the presence of the compounds. With this good correlation between in silico screening and positive efflux inhibitory activity in vitro, the two compounds, lanatoside C and diadzein could be promising efflux pump inhibitors and effective to use in combination

Predictive validity of common mental disorders screening questionnaire as a screening instrument in long term sickness absence

DEFF Research Database (Denmark)

Søgaard, Hans Jørgen; Bech, Per

2010-01-01

AIMS: Screening instruments for detection of common mental disorders have not been validity tested in long term sickness absence (LSA), which is the aim of this study for the Common Mental Disorders Screening Questionnaire (CMD-SQ). METHODS: Of all 2,414 incident persons on continuous sick...... in Denmark there is not a legal requirement that sick-listed persons are certified as sick by a physician....

Use of natural and archaeological analogs to validate long - term behaviour of HLW glass in geological disposal conditions

International Nuclear Information System (INIS)

Gin, S.; Verney-Carron, A.; Libourel, G.

2008-01-01

Some old basaltic and Roman glasses have been studied in order to validate the predictive models developed for assessing the long-term behaviour of nuclear glass in geological repository conditions. Leaching behaviour of basaltic glass altered in both laboratory and natural environment conditions allows to validate the key mechanisms that control glass dissolution kinetics and the order of magnitude of glass packages lifetime In a stable clayey formation (French reference concept for a geological disposal of high level waste). The study of Roman glass blocks (with the same geometry as nuclear glass package) altered during 1800 years in a marine environment gives new insight on the basic mechanisms involved in confined media (fractures and small cracks). Results show the importance of the coupling between transport of reactive species and chemical reactions. This study, still in progress, would allow to validate the modelling of such a complex system. (author)

Phenolic Molding Compounds

Science.gov (United States)

Koizumi, Koji; Charles, Ted; de Keyser, Hendrik

Phenolic Molding Compounds continue to exhibit well balanced properties such as heat resistance, chemical resistance, dimensional stability, and creep resistance. They are widely applied in electrical, appliance, small engine, commutator, and automotive applications. As the focus of the automotive industry is weight reduction for greater fuel efficiency, phenolic molding compounds become appealing alternatives to metals. Current market volumes and trends, formulation components and its impact on properties, and a review of common manufacturing methods are presented. Molding processes as well as unique advanced techniques such as high temperature molding, live sprue, and injection/compression technique provide additional benefits in improving the performance characterisitics of phenolic molding compounds. Of special interest are descriptions of some of the latest innovations in automotive components, such as the phenolic intake manifold and valve block for dual clutch transmissions. The chapter also characterizes the most recent developments in new materials, including long glass phenolic molding compounds and carbon fiber reinforced phenolic molding compounds exhibiting a 10-20-fold increase in Charpy impact strength when compared to short fiber filled materials. The role of fatigue testing and fatigue fracture behavior presents some insight into long-term reliability and durability of glass-filled phenolic molding compounds. A section on new technology outlines the important factors to consider in modeling phenolic parts by finite element analysis and flow simulation.

Approach suitable for screening estimation methods for critical properties of heavy compounds

DEFF Research Database (Denmark)

Zbogar, A.; vidal da Silva Lopes, F.; Kontogeorgis, Georgios

2006-01-01

) is in agreement with their validation via the proposed equation. Similar results have been obtained for other compounds. Both group-contribution methods are of equal accuracy for heavy alkenes and acids, provided that experimental boiling point temperatures are available for the Joback method. If such data...... the very heavy and complex ones, follow the trend suggested by this equation. This equation can be used for testing existing group-contribution estimation methods. It is shown here that direct comparison of the Joback and Constantinou-Gani methods for two families of compounds (alkenes and carboxylic acids......- and diacids, alkenes, cyclo/phenylalkanes, and squalane). This and previous validations verify that this correlation has a much broader application range, up to (T-c/p(c)) ratios of 200, than the data used in its development (compounds with ratios up to 100). it seems that most organic compounds, including...

Prediction of cognitive and motor development in preterm children using exhaustive feature selection and cross-validation of near-term white matter microstructure.

Science.gov (United States)

Schadl, Kornél; Vassar, Rachel; Cahill-Rowley, Katelyn; Yeom, Kristin W; Stevenson, David K; Rose, Jessica

2018-01-01

Advanced neuroimaging and computational methods offer opportunities for more accurate prognosis. We hypothesized that near-term regional white matter (WM) microstructure, assessed on diffusion tensor imaging (DTI), using exhaustive feature selection with cross-validation would predict neurodevelopment in preterm children. Near-term MRI and DTI obtained at 36.6 ± 1.8 weeks postmenstrual age in 66 very-low-birth-weight preterm neonates were assessed. 60/66 had follow-up neurodevelopmental evaluation with Bayley Scales of Infant-Toddler Development, 3rd-edition (BSID-III) at 18-22 months. Linear models with exhaustive feature selection and leave-one-out cross-validation computed based on DTI identified sets of three brain regions most predictive of cognitive and motor function; logistic regression models were computed to classify high-risk infants scoring one standard deviation below mean. Cognitive impairment was predicted (100% sensitivity, 100% specificity; AUC = 1) by near-term right middle-temporal gyrus MD, right cingulate-cingulum MD, left caudate MD. Motor impairment was predicted (90% sensitivity, 86% specificity; AUC = 0.912) by left precuneus FA, right superior occipital gyrus MD, right hippocampus FA. Cognitive score variance was explained (29.6%, cross-validated Rˆ2 = 0.296) by left posterior-limb-of-internal-capsule MD, Genu RD, right fusiform gyrus AD. Motor score variance was explained (31.7%, cross-validated Rˆ2 = 0.317) by left posterior-limb-of-internal-capsule MD, right parahippocampal gyrus AD, right middle-temporal gyrus AD. Search in large DTI feature space more accurately identified neonatal neuroimaging correlates of neurodevelopment.

Calibrating and validating a FE model for long-term behavior of RC beams

Directory of Open Access Journals (Sweden)

Tošić Nikola D.

2014-01-01

Full Text Available This study presents the research carried out in finding an optimal finite element (FE model for calculating the long-term behavior of reinforced concrete (RC beams. A multi-purpose finite element software DIANA was used. A benchmark test in the form of a simply supported beam loaded in four point bending was selected for model calibration. The result was the choice of 3-node beam elements, a multi-directional fixed crack model with constant stress cut-off, nonlinear tension softening and constant shear retention and a creep and shrinkage model according to CEB-FIP Model Code 1990. The model was then validated on 14 simply supported beams and 6 continuous beams. Good agreement was found with experimental results (within ±15%.

Structure Modification of an Active Azo-Compound as a Route to New Antimicrobial Compounds

Directory of Open Access Journals (Sweden)

Simona Concilio

2017-05-01

Full Text Available Some novel (phenyl-diazenylphenols 3a–g were designed and synthesized to be evaluated for their antimicrobial activity. A previously synthesized molecule, active against bacteria and fungi, was used as lead for modifications and optimization of the structure, by introduction/removal or displacement of hydroxyl groups on the azobenzene rings. The aim of this work was to evaluate the consequent changes of the antimicrobial activity and to validate the hypothesis that, for these compounds, a plausible mechanism could involve an interaction with protein receptors, rather than an interaction with membrane. All newly synthesized compounds were analyzed by 1H-NMR, DSC thermal analysis and UV-Vis spectroscopy. The in vitro minimal inhibitory concentrations (MIC of each compound was determined against Gram-positive and Gram-negative bacteria and Candida albicans. Compounds 3b and 3g showed the highest activity against S. aureus and C. albicans, with remarkable MIC values of 10 µg/mL and 3 µg/mL, respectively. Structure-activity relationship studies were capable to rationalize the effect of different substitutions on the phenyl ring of the azobenzene on antimicrobial activity.

Determination of quaternary ammonium compounds by potentiometric titration with an ionic surfactant electrode: single-laboratory validation.

Science.gov (United States)

Price, Randi; Wan, Ping

2010-01-01

A potentiometric titration for determining the quaternary ammonium compounds (QAC) commonly found in antimicrobial products was validated by a single laboratory. Traditionally, QACs were determined by using a biphasic (chloroform and water) manual titration procedure. Because of safety considerations regarding chloroform, as well as the subjectivity of color indicator-based manual titration determinations, an automatic potentiometric titration procedure was tested with quaternary nitrogen product formulations. By using the Metrohm Titrando system coupled with an ionic surfactant electrode and an Ag/AgCl reference electrode, titrations were performed with various QAC-containing formulation products/matrixes; a standard sodium lauryl sulfate solution was used as the titrant. Results for the products tested are sufficiently reproducible and accurate for the purpose of regulatory product enforcement. The robustness of the method was measured by varying pH levels, as well as by comparing buffered versus unbuffered titration systems. A quantitation range of 1-1000 ppm quaternary nitrogen was established. Eight commercially available antimicrobial products covering a variety of matrixes were assayed; the results obtained were comparable to those obtained by the manual titration method. Recoveries of 94 to 104% were obtained for spiked samples.

Maximum hardness and minimum polarizability principles through lattice energies of ionic compounds

International Nuclear Information System (INIS)

Kaya, Savaş; Kaya, Cemal; Islam, Nazmul

2016-01-01

The maximum hardness (MHP) and minimum polarizability (MPP) principles have been analyzed using the relationship among the lattice energies of ionic compounds with their electronegativities, chemical hardnesses and electrophilicities. Lattice energy, electronegativity, chemical hardness and electrophilicity values of ionic compounds considered in the present study have been calculated using new equations derived by some of the authors in recent years. For 4 simple reactions, the changes of the hardness (Δη), polarizability (Δα) and electrophilicity index (Δω) were calculated. It is shown that the maximum hardness principle is obeyed by all chemical reactions but minimum polarizability principles and minimum electrophilicity principle are not valid for all reactions. We also proposed simple methods to compute the percentage of ionic characters and inter nuclear distances of ionic compounds. Comparative studies with experimental sets of data reveal that the proposed methods of computation of the percentage of ionic characters and inter nuclear distances of ionic compounds are valid.

Maximum hardness and minimum polarizability principles through lattice energies of ionic compounds

Energy Technology Data Exchange (ETDEWEB)

Kaya, Savaş, E-mail: savaskaya@cumhuriyet.edu.tr [Department of Chemistry, Faculty of Science, Cumhuriyet University, Sivas 58140 (Turkey); Kaya, Cemal, E-mail: kaya@cumhuriyet.edu.tr [Department of Chemistry, Faculty of Science, Cumhuriyet University, Sivas 58140 (Turkey); Islam, Nazmul, E-mail: nazmul.islam786@gmail.com [Theoretical and Computational Chemistry Research Laboratory, Department of Basic Science and Humanities/Chemistry Techno Global-Balurghat, Balurghat, D. Dinajpur 733103 (India)

2016-03-15

The maximum hardness (MHP) and minimum polarizability (MPP) principles have been analyzed using the relationship among the lattice energies of ionic compounds with their electronegativities, chemical hardnesses and electrophilicities. Lattice energy, electronegativity, chemical hardness and electrophilicity values of ionic compounds considered in the present study have been calculated using new equations derived by some of the authors in recent years. For 4 simple reactions, the changes of the hardness (Δη), polarizability (Δα) and electrophilicity index (Δω) were calculated. It is shown that the maximum hardness principle is obeyed by all chemical reactions but minimum polarizability principles and minimum electrophilicity principle are not valid for all reactions. We also proposed simple methods to compute the percentage of ionic characters and inter nuclear distances of ionic compounds. Comparative studies with experimental sets of data reveal that the proposed methods of computation of the percentage of ionic characters and inter nuclear distances of ionic compounds are valid.

Compound Decomposition in Dutch Large Vocabulary Speech Recognition

NARCIS (Netherlands)

Ordelman, Roeland J.F.; van Hessen, Adrianus J.; de Jong, Franciska M.G.

2003-01-01

This paper addresses compound splitting for Dutch in the context of broadcast news transcription. Language models were created using original text versions and text versions that were decomposed using a data-driven compound splitting algorithm. Language model performances were compared in terms of

Toxicity prediction of compounds from turmeric (Curcuma longa L).

Science.gov (United States)

Balaji, S; Chempakam, B

2010-10-01

Turmeric belongs to the ginger family Zingiberaceae. Currently, cheminformatics approaches are not employed in any of the spices to study the medicinal properties traditionally attributed to them. The aim of this study is to find the most efficacious molecule which does not have any toxic effects. In the present study, toxicity of 200 chemical compounds from turmeric were predicted (includes bacterial mutagenicity, rodent carcinogenicity and human hepatotoxicity). The study shows out of 200 compounds, 184 compounds were predicted as toxigenic, 136 compounds are mutagenic, 153 compounds are carcinogenic and 64 compounds are hepatotoxic. To cross validate our results, we have chosen the popular curcumin and found that curcumin and its derivatives may cause dose dependent hepatotoxicity. The results of these studies indicate that, in contrast to curcumin, few other compounds in turmeric which are non-mutagenic, non-carcinogenic, non-hepatotoxic, and do not have any side-effects. Hence, the cost-effective approach presented in this paper could be used to filter toxic compounds from the drug discovery lifecycle. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

The Lattice Compatibility Theory LCT: Physical and Chemical Arguments from the Growth Behavior of Doped Compounds in terms of Bandgap Distortion and Magnetic Effects

Directory of Open Access Journals (Sweden)

K. Boubaker

2013-01-01

Full Text Available Physical and chemical arguments for the recently discussed materials-related Lattice Compatibility Theory are presented. The discussed arguments are based on some differences of Mn ions incorporation kinetics inside some compounds. These differences have been evaluated and quantified in terms of alteration of bandgap edges, magnetic patterns, and Faraday effect.

Compound odontoma

Directory of Open Access Journals (Sweden)

Monica Yadav

2012-01-01

Full Text Available Odontomas have been extensively reported in the dental literature, and the term refers to tumors of odontogenic origin. Though the exact etiology is still unknown, the postulated causes include: local trauma, infection, inheritance and genetic mutation. The majority of the lesions are asymptomatic; however, may be accompanied with pain and swelling as secondary complaints in some cases. Here, we report a case of a compound odontome in a 14 year old patient.

Prediction of long-term absence due to sickness in employees: development and validation of a multifactorial risk score in two cohort studies.

Science.gov (United States)

Airaksinen, Jaakko; Jokela, Markus; Virtanen, Marianna; Oksanen, Tuula; Koskenvuo, Markku; Pentti, Jaana; Vahtera, Jussi; Kivimäki, Mika

2018-01-24

Objectives This study aimed to develop and validate a risk prediction model for long-term sickness absence. Methods Survey responses on work- and lifestyle-related questions from 65 775 public-sector employees were linked to sickness absence records to develop a prediction score for medically-certified sickness absence lasting >9 days and ≥90 days. The score was externally validated using data from an independent population-based cohort of 13 527 employees. For both sickness absence outcomes, a full model including 46 candidate predictors was reduced to a parsimonious model using least-absolute-shrinkage-and-selection-operator (LASSO) regression. Predictive performance of the model was evaluated using C-index and calibration plots. Results Variance explained in ≥90-day sickness absence by the full model was 12.5%. In the parsimonious model, the predictors included self-rated health (linear and quadratic term), depression, sex, age (linear and quadratic), socioeconomic position, previous sickness absences, number of chronic diseases, smoking, shift work, working night shift, and quadratic terms for body mass index and Jenkins sleep scale. The discriminative ability of the score was good (C-index 0.74 in internal and 0.73 in external validation). Calibration plots confirmed high correspondence between the predicted and observed risk. In >9-day sickness absence, the full model explained 15.2% of the variance explained, but the C-index of the parsimonious model was poor (<0.65). Conclusions Individuals' risk of a long-term sickness absence that lasts ≥90 days can be estimated using a brief risk score. The predictive performance of this score is comparable to those for established multifactorial risk algorithms for cardiovascular disease, such as the Framingham risk score.

Validity of food frequency questionnaire-based estimates of long-term long-chain n-3 polyunsaturated fatty acid intake.

Science.gov (United States)

Wallin, Alice; Di Giuseppe, Daniela; Burgaz, Ann; Håkansson, Niclas; Cederholm, Tommy; Michaëlsson, Karl; Wolk, Alicja

2014-01-01

To evaluate how long-term dietary intake of long-chain n-3 polyunsaturated fatty acids (LCn-3 PUFAs), estimated by repeated food frequency questionnaires (FFQs) over 15 years, is correlated with LCn-3 PUFAs in adipose tissue (AT). Subcutaneous adipose tissue was obtained in 2003-2004 (AT-03) from 239 randomly selected women, aged 55-75 years, after completion of a 96-item FFQ (FFQ-03). All participants had previously returned an identical FFQ in 1997 (FFQ-97) and a 67-item version in 1987-1990 (FFQ-87). Pearson product-moment correlations were used to evaluate associations between intake of total and individual LCn-3 PUFAs as estimated by the three FFQ assessments and AT-03 content (% of total fatty acids). FFQ-estimated mean relative intake of LCn-3 PUFAs (% of total fat intake) increased between all three assessments (FFQ-87, 0.55 ± 0.34; FFQ-97, 0.74 ± 0.64; FFQ-03, 0.88 ± 0.56). Validity, in terms of Pearson correlations between FFQ-03 estimates and AT-03 content, was 0.41 (95% CI 0.30-0.51) for total LCn-3 PUFA and ranged from 0.29 to 0.48 for individual fatty acids; lower correlation was observed among participants with higher percentage body fat. With regard to long-term intake estimates, past dietary intake was also correlated with AT-03 content, with correlation coefficients in the range of 0.21-0.33 and 0.21-0.34 for FFQ-97 and FFQ-87, respectively. The correlations were improved by using average estimates from two or more FFQ assessments. Exclusion of fish oil supplement users (14%) did not alter the correlations. These data indicate reasonable validity of FFQ-based estimates of long-term (up to 15 years) LCn-3 PUFA intake, justifying their use in studies of diet-disease associations.

Validation of exhaled volatile organic compounds analysis using electronic nose as index of COPD severity

Directory of Open Access Journals (Sweden)

Finamore P

2018-05-01

Full Text Available Panaiotis Finamore,1 Claudio Pedone,1 Simone Scarlata,1 Alessandra Di Paolo,1 Simone Grasso,2 Marco Santonico,2 Giorgio Pennazza,2 Raffaele Antonelli Incalzi1 1Unit of Geriatrics, Campus Bio-Medico di Roma University, Rome, Italy; 2Unit of Electronics for Sensor Systems, Campus Bio-Medico di Roma University, Rome, Italy Aim: Six-minute walking test distance (6MWD and body mass index, obstruction, dyspnea and exercise (BODE index are measures of functional status in COPD patients, but require space, time and patient’s compliance. Exhaled volatile organic compounds (VOCs analysis via electronic nose is a quick and easy method that has already been used to discriminate COPD phenotypes. The aim of this study is to evaluate whether VOCs analysis can predict functional status and its variation over time in COPD patients.Methods: A monocentric prospective study with 1 year of follow-up was carried out. All patients underwent pulmonary function tests, arterial gas analysis, bioimpedance analysis, 6-minute walking test, and VOCs collection. Exhaled breath was collected with Pneumopipe® and analyzed using BIONOTE electronic nose. Outcomes prediction was performed by k-fold cross-validated partial least square discriminant analysis: accuracy, sensitivity and specificity as well as Cohen’s kappa for agreement were calculated.Results: We enrolled 63 patients, 60.3% men, with a mean age of 71 (SD: 8 years, median BODE index of 1 (interquartile range: 0–3 and mean 6MWD normalized by squared height (n6MWD of 133.5 (SD: 42 m/m2. The BIONOTE predicted baseline BODE score (dichotomized as BODE score <3 or ≥3 with an accuracy of 86% and quartiles of n6MWD with an accuracy of 79%. n6MWD decline more than the median value after 1 year was predicted with an accuracy of 86% by BIONOTE, 52% by Global Initiative for Chronic Obstructive Lung Disease (GOLD class and 78% by combined BIONOTE and GOLD class.Conclusion: Exhaled VOCs analysis identifies classes of BODE

Development and validation of a prediction model for long-term sickness absence based on occupational health survey variables.

Science.gov (United States)

Roelen, Corné; Thorsen, Sannie; Heymans, Martijn; Twisk, Jos; Bültmann, Ute; Bjørner, Jakob

2018-01-01

The purpose of this study is to develop and validate a prediction model for identifying employees at increased risk of long-term sickness absence (LTSA), by using variables commonly measured in occupational health surveys. Based on the literature, 15 predictor variables were retrieved from the DAnish National working Environment Survey (DANES) and included in a model predicting incident LTSA (≥4 consecutive weeks) during 1-year follow-up in a sample of 4000 DANES participants. The 15-predictor model was reduced by backward stepwise statistical techniques and then validated in a sample of 2524 DANES participants, not included in the development sample. Identification of employees at increased LTSA risk was investigated by receiver operating characteristic (ROC) analysis; the area-under-the-ROC-curve (AUC) reflected discrimination between employees with and without LTSA during follow-up. The 15-predictor model was reduced to a 9-predictor model including age, gender, education, self-rated health, mental health, prior LTSA, work ability, emotional job demands, and recognition by the management. Discrimination by the 9-predictor model was significant (AUC = 0.68; 95% CI 0.61-0.76), but not practically useful. A prediction model based on occupational health survey variables identified employees with an increased LTSA risk, but should be further developed into a practically useful tool to predict the risk of LTSA in the general working population. Implications for rehabilitation Long-term sickness absence risk predictions would enable healthcare providers to refer high-risk employees to rehabilitation programs aimed at preventing or reducing work disability. A prediction model based on health survey variables discriminates between employees at high and low risk of long-term sickness absence, but discrimination was not practically useful. Health survey variables provide insufficient information to determine long-term sickness absence risk profiles. There is a need for

Ascorbic acid, β-carotene, total phenolic compound and ...

African Journals Online (AJOL)

A two year study at Alexandria University compared ascorbic acid, β-carotene, total phenolic compound, nitrite content and microbiological quality of orange and strawberry fruits grown under organic and conventional management techniques to see if producers concerns are valid. Organically grown oranges and ...

Validation of short term recall of mobile phone use for the Interphone study

DEFF Research Database (Denmark)

Vrijheid, M; Cardis, E; Armstrong, B K

2006-01-01

AIM: To validate short term recall of mobile phone use within Interphone, an international collaborative case control study of tumours of the brain, acoustic nerve, and salivary glands related to mobile telephone use. METHODS: Mobile phone use of 672 volunteers in 11 countries was recorded...... with moderate systematic error and substantial random error. This large random error can be expected to reduce the power of the Interphone study to detect an increase in risk of brain, acoustic nerve, and parotid gland tumours with increasing mobile phone use, if one exists....... by operators or through the use of software modified phones, and compared to use recalled six months later using the Interphone study questionnaire. Agreement between recalled and actual phone use was analysed using both categorical and continuous measures of number and duration of phone calls. RESULTS...

Validated method for the determination of perfluorinated compounds in placental tissue samples based on a simple extraction procedure followed by ultra-high performance liquid chromatography-tandem mass spectrometry analysis.

Science.gov (United States)

Martín, J; Rodríguez-Gómez, R; Zafra-Gómez, A; Alonso, E; Vílchez, J L; Navalón, A

2016-04-01

Xenobiotic exposure during pregnancy is inevitable. Determination of perfluorinated compounds (PFCs), chemicals described as environmental contaminants by Public Health Authorities due to their persistence, bioaccumulation and toxicity, is a challenge. In the present work, a method based on a simplified sample treatment involving freeze-drying, solvent extraction and dispersive clean-up of the extracts using C18 sorbents followed by an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis was developed and validated for the determination of five perfluorinated carboxylic acids (C4-C8) and perfluorooctane sulfonate (PFOS) in placental tissue samples. The most influential parameters affecting the extraction method and clean-up were optimized using Design of Experiments (DOE). The method was validated using matrix-matched calibration. Found limits of detection (LODs) ranged from 0.03 to 2 ng g(-1) and limits of quantification (LOQs) from 0.08 to 6 ng g(-1), while inter- and intra-day variability was under 14% in all cases. Recovery rates for spiked samples ranged from 94% to 113%. The method was satisfactorily applied for the determination of compounds in human placental tissue samples collected at delivery from 25 randomly selected women. Copyright © 2015 Elsevier B.V. All rights reserved.

Thin-film microextraction coupled to LC-ESI-MS/MS for determination of quaternary ammonium compounds in water samples.

Science.gov (United States)

Boyacı, Ezel; Sparham, Chris; Pawliszyn, Janusz

2014-01-01

The dual nature of the quaternary ammonium compounds, having permanently charged hydrophilic quaternary ammonium heads and long-chain hydrophobic tails, makes the sample preparation step and analysis of these compounds challenging. A high-throughput method based on thin-film solid-phase microextraction (SPME) and liquid chromatography mass spectrometry was developed for simultaneous quantitative analysis of nine benzylic and aliphatic quaternary ammonium compounds. Chromatographic separation and detection of analytes were obtained in reverse-phase mode in 8 min using a triple quadrupole mass spectrometer. Hydrophilic lipophilic balance particle-coated blades were found to be the most suitable among the different coatings tested in terms of recoveries and carryover on the blades. For desorption solvents, 70/30, v/v (A/B) with 0.1 % formic acid (where A is 10 mM ammonium acetate in acetonitrile/water (95/5 , v/v) and B is 0.1 %  (v/v) formic acid in isopropyl alcohol) was shown to be the most efficient solvent for the desorption of the analytes from the SPME sorbent. The SPME method was optimised in terms of extraction, pH, and preconditioning, as well as extraction and desorption times. Optimum conditions were 45 min of extraction time and 15 min of desorption time, all with agitation. The extraction was found to be optimum in a range of pH 6.0 to 8.0, which is consistent with the natural pH of water samples. Wide linear dynamic ranges with the developed method were obtained for each compound, enabling the application of the method for a wide range of concentrations. The developed method was validated according to the Food and Drug Administration criteria. The proposed method is the first SPME-based approach describing the applicability of the high-throughput thin-film SPME in a 96-well system for analysis of such challenging compounds.

Long-term performance and stability of a continuous granular airlift reactor treating a high-strength wastewater containing a mixture of aromatic compounds

Energy Technology Data Exchange (ETDEWEB)

Ramos, Carlos; Suárez-Ojeda, María Eugenia; Carrera, Julián, E-mail: julian.carrera@uab.cat

2016-02-13

Highlights: • Aerobic biodegradation of a mixture of aromatics is feasible in a granular reactor. • Applied organic loading rate is a key parameter for an optimal reactor performance. • Stable mature aerobic granules were maintained 400 days in a continuous reactor. • Sphingobium, Cytophaga and Comamonas were the main genera in the aerobic granules. - Abstract: Continuous feeding operation of an airlift reactor and its inoculation with mature aerobic granules allowed the successful treatment of a mixture of aromatic compounds (p-nitrophenol, o-cresol and phenol). Complete biodegradation of p-nitrophenol, o-cresol, phenol and their metabolic intermediates was achieved at an organic loading rate of 0.61 g COD L{sup −1} d{sup −1}. Stable granulation was obtained throughout the long-term operation (400 days) achieving an average granule size of 2.0 ± 1 mm and a sludge volumetric index of 26 ± 1 mL g{sup −1} TSS. The identified genera in the aerobic granular biomass were heterotrophic bacteria able to consume aromatic compounds. Therefore, the continuous feeding regimen and the exposure of aerobic granules to a mixture of aromatic compounds make possible to obtain good granulation and high removal efficiency.

Long-term performance and stability of a continuous granular airlift reactor treating a high-strength wastewater containing a mixture of aromatic compounds

International Nuclear Information System (INIS)

Ramos, Carlos; Suárez-Ojeda, María Eugenia; Carrera, Julián

2016-01-01

Highlights: • Aerobic biodegradation of a mixture of aromatics is feasible in a granular reactor. • Applied organic loading rate is a key parameter for an optimal reactor performance. • Stable mature aerobic granules were maintained 400 days in a continuous reactor. • Sphingobium, Cytophaga and Comamonas were the main genera in the aerobic granules. - Abstract: Continuous feeding operation of an airlift reactor and its inoculation with mature aerobic granules allowed the successful treatment of a mixture of aromatic compounds (p-nitrophenol, o-cresol and phenol). Complete biodegradation of p-nitrophenol, o-cresol, phenol and their metabolic intermediates was achieved at an organic loading rate of 0.61 g COD L"−"1 d"−"1. Stable granulation was obtained throughout the long-term operation (400 days) achieving an average granule size of 2.0 ± 1 mm and a sludge volumetric index of 26 ± 1 mL g"−"1 TSS. The identified genera in the aerobic granular biomass were heterotrophic bacteria able to consume aromatic compounds. Therefore, the continuous feeding regimen and the exposure of aerobic granules to a mixture of aromatic compounds make possible to obtain good granulation and high removal efficiency.

Single-laboratory validation of a method for the determination of select volatile organic compounds in foods by using vacuum distillation with gas chromatography/mass spectrometry.

Science.gov (United States)

Nyman, Patricia J; Limm, William; Begley, Timothy H; Chirtel, Stuart J

2014-01-01

Recent studies showed that headspace and purge and trap methods have limitations when used to determine volatile organic compounds (VOCs) in foods, including matrix effects and artifact formation from precursors present in the sample matrix or from thermal decomposition. U.S. Environmental Protection Agency Method 8261A liberates VOCs from the sample matrix by using vacuum distillation at room temperature. The method was modified and validated for the determination of furan, chloroform, benzene, trichloroethene, toluene, and sytrene in infant formula, canned tuna (in water), peanut butter, and an orange beverage (orange-flavored noncarbonated beverage). The validation studies showed that the LOQ values ranged from 0.05 ng/g toluene in infant formula to 5.10 ng/g toluene in peanut butter. Fortified recoveries were determined at the first, second, and third standard additions, and concentrations ranged from 0.07 to 6.9 ng/g. When quantified by the method of standard additions, the recoveries ranged from 56 to 218% at the first standard addition and 89 to 117% at the third. The validated method was used to conduct a survey of the targeted VOCs in 18 foods. The amounts found ranged from none detected to 73.8 ng/g furan in sweet potato baby food.

Data-Driven Derivation of an "Informer Compound Set" for Improved Selection of Active Compounds in High-Throughput Screening.

Science.gov (United States)

Paricharak, Shardul; IJzerman, Adriaan P; Jenkins, Jeremy L; Bender, Andreas; Nigsch, Florian

2016-09-26

Despite the usefulness of high-throughput screening (HTS) in drug discovery, for some systems, low assay throughput or high screening cost can prohibit the screening of large numbers of compounds. In such cases, iterative cycles of screening involving active learning (AL) are employed, creating the need for smaller "informer sets" that can be routinely screened to build predictive models for selecting compounds from the screening collection for follow-up screens. Here, we present a data-driven derivation of an informer compound set with improved predictivity of active compounds in HTS, and we validate its benefit over randomly selected training sets on 46 PubChem assays comprising at least 300,000 compounds and covering a wide range of assay biology. The informer compound set showed improvement in BEDROC(α = 100), PRAUC, and ROCAUC values averaged over all assays of 0.024, 0.014, and 0.016, respectively, compared to randomly selected training sets, all with paired t-test p-values agnostic fashion. This approach led to a consistent improvement in hit rates in follow-up screens without compromising scaffold retrieval. The informer set is adjustable in size depending on the number of compounds one intends to screen, as performance gains are realized for sets with more than 3,000 compounds, and this set is therefore applicable to a variety of situations. Finally, our results indicate that random sampling may not adequately cover descriptor space, drawing attention to the importance of the composition of the training set for predicting actives.

EPlantLIBRA: A composition and biological activity database for bioactive compounds in plant food supplements

DEFF Research Database (Denmark)

Plumb, J.; Lyons, J.; Nørby, Karin Kristiane

2015-01-01

The newly developed ePlantLIBRA database is a comprehensive and searchable database, with up-to-date coherent and validated scientific information on plant food supplement (PFS) bioactive compounds, with putative health benefits as well as adverse effects, and contaminants and residues. It is the......The newly developed ePlantLIBRA database is a comprehensive and searchable database, with up-to-date coherent and validated scientific information on plant food supplement (PFS) bioactive compounds, with putative health benefits as well as adverse effects, and contaminants and residues...

Predictive Validity of the Columbia-Suicide Severity Rating Scale for Short-Term Suicidal Behavior

DEFF Research Database (Denmark)

Conway, Paul Maurice; Erlangsen, Annette; Teasdale, Thomas William

2017-01-01

adolescents (90.6% females) who participated at follow-up (85.9%) out of the 99 (49.7%) baseline respondents. All adolescents were recruited from a specialized suicide-prevention clinic in Denmark. Through multivariate logistic regression analyses, we examined whether baseline suicidal behavior predicted......Using the Columbia-Suicide Severity Rating Scale (C-SSRS), we examined the predictive and incremental predictive validity of past-month suicidal behavior and ideation for short-term suicidal behavior among adolescents at high risk of suicide. The study was conducted in 2014 on a sample of 85...... subsequent suicidal behavior (actual attempts and suicidal behavior of any type, including preparatory acts, aborted, interrupted and actual attempts; mean follow-up of 80.8 days, SD = 52.4). Furthermore, we examined whether suicidal ideation severity and intensity incrementally predicted suicidal behavior...

Assessment and validation of the CAESAR predictive model for bioconcentration factor (BCF in fish

Directory of Open Access Journals (Sweden)

Milan Chiara

2010-07-01

Full Text Available Abstract Background Bioconcentration factor (BCF describes the behaviour of a chemical in terms of its likelihood of concentrating in organisms in the environment. It is a fundamental property in recent regulations, such as the European Community Regulation on chemicals and their safe use or the Globally Harmonized System for classification, labelling and packaging. These new regulations consider the possibility of reducing or waiving animal tests using alternative methods, such as in silico methods. This study assessed and validated the CAESAR predictive model for BCF in fish. Results To validate the model, new experimental data were collected and used to create an external set, as a second validation set (a first validation exercise had been done just after model development. The performance of the model was compared with BCFBAF v3.00. For continuous values and for classification purposes the CAESAR BCF model gave better results than BCFBAF v3.00 for the chemicals in the applicability domain of the model. R2 and Q2 were good and accuracy in classification higher than 90%. Applying an offset of 0.5 to the compounds predicted with BCF close to the thresholds, the number of false negatives (the most dangerous errors dropped considerably (less than 0.6% of chemicals. Conclusions The CAESAR model for BCF is useful for regulatory purposes because it is robust, reliable and predictive. It is also fully transparent and documented and has a well-defined applicability domain, as required by REACH. The model is freely available on the CAESAR web site and easy to use. The reliability of the model reporting the six most similar compounds found in the CAESAR dataset, and their experimental and predicted values, can be evaluated.

Development and content validation of a questionnaire to assess moral distress among social workers in long-term care facilities.

Science.gov (United States)

Lev, Sagit; Ayalon, Liat

2018-03-01

Despite the significance of ethical issues faced by social workers, research on moral distress among social workers has been extremely limited. The aim of the current study is to describe the development and content validation of a unique questionnaire to measure moral distress among social workers in long-term care facilities for older adults in Israel. The construction of the questionnaire was based on a secondary analysis of a qualitative study that addressed the moral dilemma of social workers in nursing homes in Israel. A content validation included review and evaluation by two experts, a cognitive interview with a nursing home social worker, and three focus groups of experts and the target population. The initial questionnaire consisted of 25 items. After the content validation process the questionnaire in its final version, consisted of 17 items and included two scales, measuring the frequency of morally loaded events and the intensity of distress that followed them. We believe that the questionnaire can contribute by broadening and deepening ethics discourse and research, with regard to social workers' obligation dilemmas and conflicts.

Ground-water models: Validate or invalidate

Science.gov (United States)

Bredehoeft, J.D.; Konikow, Leonard F.

1993-01-01

The word validation has a clear meaning to both the scientific community and the general public. Within the scientific community the validation of scientific theory has been the subject of philosophical debate. The philosopher of science, Karl Popper, argued that scientific theory cannot be validated, only invalidated. Popper’s view is not the only opinion in this debate; however, many scientists today agree with Popper (including the authors). To the general public, proclaiming that a ground-water model is validated carries with it an aura of correctness that we do not believe many of us who model would claim. We can place all the caveats we wish, but the public has its own understanding of what the word implies. Using the word valid with respect to models misleads the public; verification carries with it similar connotations as far as the public is concerned. Our point is this: using the terms validation and verification are misleading, at best. These terms should be abandoned by the ground-water community.

X-ray attenuation coefficient measurements for photon energies 4.508-13.375 keV in Cu, Cr and their compounds and the validity of the mixture rule

International Nuclear Information System (INIS)

Turgut, Ue.; Simsek, Oe.; Bueyuekkasap, E.; Ertugrul, M.

2004-01-01

To investigate the validity of the mixture rule which is used to compute the mass attenuation coefficients in compounds, the total mass attenuation coefficients for Cu, Cr elements and Cu 2 O, CuC 2 O 4 , CuCl 2 ·2H 2 O, Cu(C 2 H 3 O 2 ) 2 ·H 2 O, Cr 2 O 3 , Cr(NO 3 ) 3 , Cr 2 (SO 4 ) 3 ·H 2 O, Cr 3 (CH 3 CO 7 )(OH) 2 compounds were measured at photon energies between 4.508 and 13.375 keV by using the secondary excitation method. Ti, Mn, Fe, Ni, Zn, Ge, As, Rb elements were used as secondary exciters. 59.5 keV gamma rays emitted from an 241 Am annular source were used to excite the secondary exciters and Kα (K-L 3 , L 2 ) rays emitted from the secondary exciter were counted by a Si(Li) detector with a resolution of 160 eV at 5.9 keV. Our measurements indicate that the mixture rule is not a suitable method for the computation of mass attenuation coefficients of compounds especially at an energy that is near the absorption edge. Obtained values were compared with theoretical values

Few long-term effects of simulated climate change on volatile organic compound emissions and leaf chemistry of three subarctic dwarf shrubs

DEFF Research Database (Denmark)

Rinnan, Riikka; Rinnan, Åsmund; Faubert, Patrick

2011-01-01

Climate change is exposing arctic ecosystems to higher temperature, increased nutrient availability and shading due to the increasing cloud cover and the expanding forests. In this work, we assessed how these factors affect the emissions of biogenic volatile organic compounds (BVOCs) from three......-selinene from S. phylicifolia. The shading treatment obtained by dome-shaped hessian tents did not cause clear long-term changes in leaf chemistry or BVOC emissions. The only observed change was a marginally significant increase in sesquiterpene emissions from B. nana. When the treatment effects on long...

Validation of transcutaneous bilirubin nomogram for identifying neonatal hyperbilirubinemia in healthy Chinese term and late-preterm infants: a multicenter study

Directory of Open Access Journals (Sweden)

Zhangbin Yu

2014-06-01

Full Text Available OBJECTIVE: to prospectively validate a previously constructed transcutaneous bilirubin (TcB nomogram for identifying severe hyperbilirubinemia in healthy Chinese term and late-preterm infants. METHODS: this was a multicenter study that included 9,174 healthy term and late-preterm infants in eight hospitals of China. TcB measurements were performed using a JM-103 bilirubinometer. TcB values were plotted on a previously developed TcB nomogram, to identify the predictive ability for subsequent significant hyperbilirubinemia. RESULTS: in the present study, 972 neonates (10.6% developed significant hyperbilirubinemia. The 40th percentile of the nomogram could identify all neonates who were at risk of significant hyperbilirubinemia, but with a low positive predictive value (PPV (18.9%. Of the 453 neonates above the 95th percentile, 275 subsequently developed significant hyperbilirubinemia, with a high PPV (60.7%, but with low sensitivity (28.3%. The 75th percentile was highly specific (81.9% and moderately sensitive (79.8%. The area under the curve (AUC for the TcB nomogram was 0.875. CONCLUSIONS: this study validated the previously developed TcB nomogram, which could be used to predict subsequent significant hyperbilirubinemia in healthy Chinese term and late-preterm infants. However, combining TcB nomogram and clinical risk factors could improve the predictive accuracy for severe hyperbilirubinemia, which was not assessed in the study. Further studies are necessary to confirm this combination.

Validation of transcutaneous bilirubin nomogram for identifying neonatal hyperbilirubinemia in healthy Chinese term and late-preterm infants: a multicenter study.

Science.gov (United States)

Yu, Zhangbin; Han, Shuping; Wu, Jinxia; Li, Mingxia; Wang, Huaiyan; Wang, Jimei; Liu, Jiebo; Pan, Xinnian; Yang, Jie; Chen, Chao

2014-01-01

to prospectively validate a previously constructed transcutaneous bilirubin (TcB) nomogram for identifying severe hyperbilirubinemia in healthy Chinese term and late-preterm infants. this was a multicenter study that included 9,174 healthy term and late-preterm infants in eight hospitals of China. TcB measurements were performed using a JM-103 bilirubinometer. TcB values were plotted on a previously developed TcB nomogram, to identify the predictive ability for subsequent significant hyperbilirubinemia. in the present study, 972 neonates (10.6%) developed significant hyperbilirubinemia. The 40(th) percentile of the nomogram could identify all neonates who were at risk of significant hyperbilirubinemia, but with a low positive predictive value (PPV) (18.9%). Of the 453 neonates above the 95(th) percentile, 275 subsequently developed significant hyperbilirubinemia, with a high PPV (60.7%), but with low sensitivity (28.3%). The 75(th) percentile was highly specific (81.9%) and moderately sensitive (79.8%). The area under the curve (AUC) for the TcB nomogram was 0.875. this study validated the previously developed TcB nomogram, which could be used to predict subsequent significant hyperbilirubinemia in healthy Chinese term and late-preterm infants. However, combining TcB nomogram and clinical risk factors could improve the predictive accuracy for severe hyperbilirubinemia, which was not assessed in the study. Further studies are necessary to confirm this combination. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Behaviour of mercury compounds in soil

Energy Technology Data Exchange (ETDEWEB)

Booer, J R

1944-01-01

The uses of inorganic compounds of mercury for the control of plant pests is reviewed, and a summary of the relevant chemical and physical properties of the compounds concerned is given. On chemical evidence a working hypothesis is propounded showing that all compounds may be expected to decompose into metallic mercury. A pot technique is described by means of which a correlation can be obtained between the effective mercury content of a given soil sample and the rate of growth of wheat seedlings. The mathematical treatment of the results is described, and the validity of the pot technique is verified by statistical analysis of results. Using the pot technqiue it is shown that volatilization losses are insignificant but that mercury is slowly rendered ineffective by the formation of mercuric sulphide. The effect of sulphur-reducing bacteria is considered and the influence of Vibrio desulphuricans on mercury is studied in detail. Experimental evidence obtained by the pot technique is produced to show that mercurous chloride slowly decomposes in the soil giving mercury and mercuric chloride, mercuric chloride rapidly decomposes into mercury and mercurous chloride, and other inorganic compounds decompose directly into mercury. The working hypothesis is substantiated in all major aspects. The uses and properties of the organo-mercury compounds are then discussed. Type compounds selected are ethyl mercury phosphate, phenyl mercury acetate and methoxyethyl mercury acetate. Using the pot technique it is shown that the formation of organo-mercury clays takes place and that these clays decompose giving metallic mercury. A mechanism is suggested.

Long-term studies on the effects of nonvolatile organic compounds on porous media surface areas.

Science.gov (United States)

Khachikian, Crist S; Harmon, Thomas C

2002-01-01

This paper investigates the long-term behavior of porous media contaminated by nonvolatile organic compounds (NVOC) in terms of specific interfacial surface area. Specifically, a natural sand, Moffett sand (MS), was contaminated with naphthalene and the surface area was measured repeatedly over time using nitrogen adsorption-desorption techniques. A field-contaminated sand affected by lamp-black material (LB) from former manufactured gas plant operations was also studied. Lampblack is a carbonaceous skeleton containing polycyclic aromatic hydrocarbons (PAHs) and other hydrocarbons. It is hypothesized that soils contaminated by these types of chemicals will exhibit significantly less surface area than their clean counterparts. The surface areas for the contaminated MS samples increased toward their clean-MS values during the 700-h aging period, but achieved the clean values only after pentane extraction or heating at 60 degrees C. Heating at 50 degrees C failed to achieve a similar recovery of the clean-MS surface area value. Nonspecific mass loss tracked the increase in surface area as indirect evidence that naphthalene loss was the cause of the surface area increase. For the LB samples, aging at 100 degrees C produced a slight decrease in surface area and mass while aging at 250 degrees C caused the surface area to increase roughly threefold while the mass decreased by approximately 1%. These results suggest that, under moderate heating and over the time scale of this investigation, there is a redistribution of the complex contaminant mixture on the solid matrix. Greater temperatures remove mass more efficiently and therefore exhibited the surface area increase expected in this experiment.

Unusual bond paths in organolithium compounds

International Nuclear Information System (INIS)

Bachrach, S.M.; Ritchie, J.P.

1986-01-01

We have applied the topological method to a number of organolithium compounds. The wavefunctions were determined with GAUSSIAN-82 using 3-21G basis set and fully optimized geometries. Gradient paths were obtained using the RHODER package and critical points were located using EXTREME. These results indicate the unusual nature of organolithium compounds. The strange bond paths arise mainly from the ionic nature of the C-Li interaction. We suggest that the term ''bond path'' may best be suited for covalent bonds. 4 figs., 1 tab

A new term 'Jzeff' derived from measured total attenuation coefficients of photons near the absorption edges of some compounds

International Nuclear Information System (INIS)

Polat, Recep; Icelli, Orhan

2010-01-01

In order to determine the effect of XAFS (X-ray absorption fine structure) on J zeff , we have measured μ/ρ values of compounds, which are determined by the mixture rule or the independent atomic model. Also, we want to obtain both XAFS effect and non-applicability or applicability of mixture rule. The most crucial finding in this study is that measurement of the effective atomic number is not appropriate near the absorption edge and the effective atomic number is affected by near the absorption edge. The results obtained have been compared with theoretical values. Also, the objective of this study is to show that there is a term 'J zeff ' between effective atomic numbers and absorption jump factor.

THREE DIMENSIONAL CFD MODELLING OF FLOW STRUCTURE IN COMPOUND CHANNELS

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Usman Ghani

2010-10-01

Full Text Available The computational modeling of three dimensional flows in a meandering compound channel has been performed in this research work. The flow calculations are performed by solving 3D steady state continuity and Reynolds averaged Navier-Stokes equations. The turbulence closure is approximated with standard - turbulence model. The model equations are solved numerically with a general purpose software package. A comprehensive validation of the simulated results against the experimental data and a demonstration that the software used in this study has matured enough for investigating practical engineering problems are the major contributions of this paper. The model was initially validated. This was achieved by computing streamwise point velocities at different depths of various sections and depth averaged velocities at three cross sections along the main channel and comparing these results with experimental data. After the validation of the model, predictions were made for different flow parameters including velocity contours at the surface, pressure distribution, turbulence intensity etc. The results gave an overall understanding of these flow variables in meandering channels. The simulation also established the good prediction capability of the standard - turbulence model for flows in compound channels.

Effectively identifying compound-protein interactions by learning from positive and unlabeled examples.

Science.gov (United States)

Cheng, Zhanzhan; Zhou, Shuigeng; Wang, Yang; Liu, Hui; Guan, Jihong; Chen, Yi-Ping Phoebe

2016-05-18

Prediction of compound-protein interactions (CPIs) is to find new compound-protein pairs where a protein is targeted by at least a compound, which is a crucial step in new drug design. Currently, a number of machine learning based methods have been developed to predict new CPIs in the literature. However, as there is not yet any publicly available set of validated negative CPIs, most existing machine learning based approaches use the unknown interactions (not validated CPIs) selected randomly as the negative examples to train classifiers for predicting new CPIs. Obviously, this is not quite reasonable and unavoidably impacts the CPI prediction performance. In this paper, we simply take the unknown CPIs as unlabeled examples, and propose a new method called PUCPI (the abbreviation of PU learning for Compound-Protein Interaction identification) that employs biased-SVM (Support Vector Machine) to predict CPIs using only positive and unlabeled examples. PU learning is a class of learning methods that leans from positive and unlabeled (PU) samples. To the best of our knowledge, this is the first work that identifies CPIs using only positive and unlabeled examples. We first collect known CPIs as positive examples and then randomly select compound-protein pairs not in the positive set as unlabeled examples. For each CPI/compound-protein pair, we extract protein domains as protein features and compound substructures as chemical features, then take the tensor product of the corresponding compound features and protein features as the feature vector of the CPI/compound-protein pair. After that, biased-SVM is employed to train classifiers on different datasets of CPIs and compound-protein pairs. Experiments over various datasets show that our method outperforms six typical classifiers, including random forest, L1- and L2-regularized logistic regression, naive Bayes, SVM and k-nearest neighbor (kNN), and three types of existing CPI prediction models. Source code, datasets and

Verification, validation, and reliability of predictions

International Nuclear Information System (INIS)

Pigford, T.H.; Chambre, P.L.

1987-04-01

The objective of predicting long-term performance should be to make reliable determinations of whether the prediction falls within the criteria for acceptable performance. Establishing reliable predictions of long-term performance of a waste repository requires emphasis on valid theories to predict performance. The validation process must establish the validity of the theory, the parameters used in applying the theory, the arithmetic of calculations, and the interpretation of results; but validation of such performance predictions is not possible unless there are clear criteria for acceptable performance. Validation programs should emphasize identification of the substantive issues of prediction that need to be resolved. Examples relevant to waste package performance are predicting the life of waste containers and the time distribution of container failures, establishing the criteria for defining container failure, validating theories for time-dependent waste dissolution that depend on details of the repository environment, and determining the extent of congruent dissolution of radionuclides in the UO 2 matrix of spent fuel. Prediction and validation should go hand in hand and should be done and reviewed frequently, as essential tools for the programs to design and develop repositories. 29 refs

Development, validation and application of a process for the generation of long-term stable VOC gas mixtures; Entwicklung, Validierung und Anwendung eines Verfahrens zur Erzeugung langzeitstabiler VOC-Gasgemische

Energy Technology Data Exchange (ETDEWEB)

Richter, Matthias

2010-07-01

The development as well as the validation of a gas mixing system (GMS) that enables dynamic and traceable production of stable long-term VOC gas mixtures within the range between a few {mu}g/m{sup 3} and a few 100 {mu}g/m{sup 3}, is discussed. In this method pure liquid substances that are filled into stainless steel bottles are kept separately at a constant temperature, evaporated according to their vapour pressure and removed by a small inert gas flow. They are finally united in a gas mixing chamber. The carrier gas must be as small as possible so that the quasi-equilibrium between the gas space and the liquid phase in the substance bottles will not be disturbed. The carrier gas is assumed to be saturated with substance gas due to a long residence time in the bottles and a fast phase transition. Any concentration level of the gas mixture can be generated by a combination of vaporization temperature, carrier and dilution gas flows. With the GMS a mixture of 25 VOCs was prepared. For 16 compounds stable and reproducible gas concentrations were realized. Due to not completely removed leakage of some substance bottles and the tubing respectively, variation of the concentration of the remaining compounds was found. A sink effect as another reason for this variation could be expelled and the chemical stability of the vaporized substances proved with the exception of some aldehydes. The procedure was successfully applied in a round robin test and a material test. In the latter adsorption of VOCs on building products was scrutinized. In this way the applicability of the GMS could be shown. (orig.)

Vanadium Compounds as PTP Inhibitors

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Elsa Irving

2017-12-01

Full Text Available Phosphotyrosine signaling is regulated by the opposing actions of protein tyrosine kinases (PTKs and protein tyrosine phosphatases (PTPs. Here we discuss the potential of vanadium derivatives as PTP enzyme inhibitors and metallotherapeutics. We describe how vanadate in the V oxidized state is thought to inhibit PTPs, thus acting as a pan-inhibitor of this enzyme superfamily. We discuss recent developments in the biological and biochemical actions of more complex vanadium derivatives, including decavanadate and in particular the growing number of oxidovanadium compounds with organic ligands. Pre-clinical studies involving these compounds are discussed in the anti-diabetic and anti-cancer contexts. Although in many cases PTP inhibition has been implicated, it is also clear that many such compounds have further biochemical effects in cells. There also remain concerns surrounding off-target toxicities and long-term use of vanadium compounds in vivo in humans, hindering their progress through clinical trials. Despite these current misgivings, interest in these chemicals continues and many believe they could still have therapeutic potential. If so, we argue that this field would benefit from greater focus on improving the delivery and tissue targeting of vanadium compounds in order to minimize off-target toxicities. This may then harness their full therapeutic potential.

Rapid identification of herbal compounds derived metabolites using zebrafish larvae as the biotransformation system.

Science.gov (United States)

Wang, Chen; Yin, Ying-Hao; Wei, Ying-Jie; Shi, Zi-Qi; Liu, Jian-Qun; Liu, Li-Fang; Xin, Gui-Zhong

2017-09-15

Metabolites derived from herbal compounds are becoming promising sources for discovering new drugs. However, the rapid identification of metabolites from biological matrixes is limited by massive endogenous interference and low abundance of metabolites. Thus, by using zebrafish larvae as the biotransformation system, we herein proposed and validated an integrated strategy for rapid identification of metabolites derived from herbal compounds. Two pivotal steps involved in this strategy are to differentiate metabolites from herbal compounds and match metabolites with their parent compounds. The differentiation step was achieved by cross orthogonal partial least-squares discriminant analysis. Automatic matching analysis was performed on R Project based on a self-developed program, of which the number of matched ionic clusters and its corresponding percentage between metabolite and parent compound were taken into account to assess their similarity. Using this strategy, 46 metabolites screened from incubation water samples of zebrafish treated with total Epimedium flavonoids (EFs) could be matched with their corresponding parent compounds, 37 of them were identified and validated by the known metabolic pathways and fragmentation patterns. Finally, 75% of the identified EFs metabolites were successfully detected in urine samples of rats treated with EFs. These experimental results indicate that the proposed strategy using zebrafish larvae as the biotransformation system will facilitate the rapid identification of metabolites derived from herbal compounds, which shows promising perspectives in providing additional resources for pharmaceutical developments from natural products. Copyright © 2017 Elsevier B.V. All rights reserved.

Validity of single term energy expression for ground state rotational band of even-even nuclei

International Nuclear Information System (INIS)

Sharma, S.; Kumar, R.; Gupta, J.B.

2005-01-01

Full text: There are large numbers of empirical studies of gs band of even-even nuclei in various mass regions. The Bohr-Mottelson's energy expression is E(I) = AX + BX 2 +CX 3 +... where X = I(I+1). The anharmonic vibrator energy expression is: E(I) = al + bl 2 + cl 3 SF model with energy expression: E(I)= pX + qI + rXI... where the terms represents the rotational, vibrational and R-V interaction energy, respectively. The validity f the various energy expressions with two terms had been tested by Sharma for light, medium and heavy mass regions using R I s. R 4 plots (where, spin I=6, 8, 10, 12), which are parameter independent. It was also noted, that of the goodness of energy expression can be judged with the minimum input of energies (i.e. only 2 parameters) and predictability's of the model p to high spins. Recently, Gupta et. al proposed a single term energy expression (SSTE) which was applied for rare earth region. This proposed power law reflected the unity of rotation - vibration in a different way and was successful in explaining the structure of gs-band. It will be useful for test the single term energy expression for light and heavy mass region. The single term expression for energy of ground state band can be written as: E I =axI b , where the index b and the coefficient a are the constant for the band. The values of b+1 and a 1 are as follows: b 1 =log(R 1 )/log(I/2) and a 1 =E I /I b ... The following results were gained: 1) The sharp variation in the value of index b at given spin will be an indication of the change in the shape of the nucleus; 2) The value of E I /I b is fairly constant with spin below back-bending, which reflects the stability of shape with spin; 3) This proposed power law is successful in explaining the structure of gs-band of nuclei

Synergy Maps: exploring compound combinations using network-based visualization.

Science.gov (United States)

Lewis, Richard; Guha, Rajarshi; Korcsmaros, Tamás; Bender, Andreas

2015-01-01

The phenomenon of super-additivity of biological response to compounds applied jointly, termed synergy, has the potential to provide many therapeutic benefits. Therefore, high throughput screening of compound combinations has recently received a great deal of attention. Large compound libraries and the feasibility of all-pairs screening can easily generate large, information-rich datasets. Previously, these datasets have been visualized using either a heat-map or a network approach-however these visualizations only partially represent the information encoded in the dataset. A new visualization technique for pairwise combination screening data, termed "Synergy Maps", is presented. In a Synergy Map, information about the synergistic interactions of compounds is integrated with information about their properties (chemical structure, physicochemical properties, bioactivity profiles) to produce a single visualization. As a result the relationships between compound and combination properties may be investigated simultaneously, and thus may afford insight into the synergy observed in the screen. An interactive web app implementation, available at http://richlewis42.github.io/synergy-maps, has been developed for public use, which may find use in navigating and filtering larger scale combination datasets. This tool is applied to a recent all-pairs dataset of anti-malarials, tested against Plasmodium falciparum, and a preliminary analysis is given as an example, illustrating the disproportionate synergism of histone deacetylase inhibitors previously described in literature, as well as suggesting new hypotheses for future investigation. Synergy Maps improve the state of the art in compound combination visualization, by simultaneously representing individual compound properties and their interactions. The web-based tool allows straightforward exploration of combination data, and easier identification of correlations between compound properties and interactions.

The Consequences of Consequential Validity.

Science.gov (United States)

Mehrens, William A.

1997-01-01

There is no agreement at present about the importance or meaning of the term "consequential validity." It is important that the authors of revisions to the "Standards for Educational and Psychological Testing" recognize the debate and relegate discussion of consequences to a context separate from the discussion of validity.…

Characterization of Phenolic Compounds in Pinus laricio Needles and Their Responses to Prescribed Burnings

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Lila Ferrat

2007-07-01

Full Text Available Fire is a dominant ecological factor in Mediterranean-type ecosystems. Management strategies include prescribed (controlled burning, which has been used in the management of several species, such as Pinus nigra ssp laricio var. Corsicana, a pine endemic to Corsica of great ecological and economic importance. The effects of prescribed burning on Pinus laricio have been little studied. The first aim of this study was to characterize total and simple phenolic compounds in Pinus laricio. The second aim was to understand: i the short term (one to three months and medium term (three years effects of prescribed burning, and ii the effects of periodic prescribed burning on the production of phenolic compounds in Pinus laricio. The first result of this study is the presence of total and simple phenolic compounds in the needles of Pinus laricio. 3-Vanillyl propanol is the major compound. After a prescribed burning, the synthesis of total phenolic compounds increases in Pinus laricio for a period of three months. Total phenolic compounds could be used as bioindicators for the short-term response of Pinus laricio needles to prescribed burning. Simple phenolic compounds do not seem to be good indicators of the impact of prescribed burning because prescribed burnings are low in intensity.

Characterization of phenolic compounds in Pinus laricio needles and their responses to prescribed burnings.

Science.gov (United States)

Cannac, Magali; Pasqualini, Vanina; Greff, Stéphane; Fernandez, Catherine; Ferrat, Lila

2007-07-30

Fire is a dominant ecological factor in Mediterranean-type ecosystems. Management strategies include prescribed (controlled) burning, which has been used in the management of several species, such as Pinus nigra ssp laricio var. Corsicana, a pine endemic to Corsica of great ecological and economic importance. The effects of prescribed burning on Pinus laricio have been little studied. The first aim of this study was to characterize total and simple phenolic compounds in Pinus laricio. The second aim was to understand: i) the short term (one to three months) and medium term (three years) effects of prescribed burning, and ii) the effects of periodic prescribed burning on the production of phenolic compounds in Pinus laricio. The first result of this study is the presence of total and simple phenolic compounds in the needles of Pinus laricio. 3-Vanillyl propanol is the major compound. After a prescribed burning, the synthesis of total phenolic compounds increases in Pinus laricio for a period of three months. Total phenolic compounds could be used as bioindicators for the short-term response of Pinus laricio needles to prescribed burning. Simple phenolic compounds do not seem to be good indicators of the impact of prescribed burning because prescribed burnings are low in intensity.

Analysis of cell death inducing compounds

DEFF Research Database (Denmark)

Spicker, Jeppe; Pedersen, Henrik Toft; Nielsen, Henrik Bjørn

2007-01-01

Biomarkers for early detection of toxicity hold the promise of improving the failure rates in drug development. In the present study, gene expression levels were measured using full-genome RAE230 version 2 Affymetrix GeneChips on rat liver tissue 48 h after administration of six different compounds......), ornithine aminotransferase (OAT) and Cytochrome P450, subfamily IIC (mephenytoin 4-hydroxylase) (Cyp2C29). RT-PCR for these three genes was performed and four additional compounds were included for validation. The quantitative RT-PCR analysis confirmed the findings based on the microarray data and using...... the three genes a classification rate of 55 of 57 samples was achieved for the classification of not toxic versus toxic. The single most promising biomarker (OAT) alone resulted in a surprisingly 100% correctly classified samples. OAT has not previously been linked to toxicity and cell death...

Groundwater Model Validation

Energy Technology Data Exchange (ETDEWEB)

Ahmed E. Hassan

2006-01-24

Models have an inherent uncertainty. The difficulty in fully characterizing the subsurface environment makes uncertainty an integral component of groundwater flow and transport models, which dictates the need for continuous monitoring and improvement. Building and sustaining confidence in closure decisions and monitoring networks based on models of subsurface conditions require developing confidence in the models through an iterative process. The definition of model validation is postulated as a confidence building and long-term iterative process (Hassan, 2004a). Model validation should be viewed as a process not an end result. Following Hassan (2004b), an approach is proposed for the validation process of stochastic groundwater models. The approach is briefly summarized herein and detailed analyses of acceptance criteria for stochastic realizations and of using validation data to reduce input parameter uncertainty are presented and applied to two case studies. During the validation process for stochastic models, a question arises as to the sufficiency of the number of acceptable model realizations (in terms of conformity with validation data). Using a hierarchical approach to make this determination is proposed. This approach is based on computing five measures or metrics and following a decision tree to determine if a sufficient number of realizations attain satisfactory scores regarding how they represent the field data used for calibration (old) and used for validation (new). The first two of these measures are applied to hypothetical scenarios using the first case study and assuming field data consistent with the model or significantly different from the model results. In both cases it is shown how the two measures would lead to the appropriate decision about the model performance. Standard statistical tests are used to evaluate these measures with the results indicating they are appropriate measures for evaluating model realizations. The use of validation

Validation and evaluation of an HPLC methodology for the quantification of the potent antimitotic compound (+)-discodermolide in the Caribbean marine sponge Discodermia dissoluta.

Science.gov (United States)

Valderrama, Katherine; Castellanos, Leonardo; Zea, Sven

2010-08-01

The sponge Discodermia dissoluta is the source of the potent antimitotic compound (+)-discodermolide. The relatively abundant and shallow populations of this sponge in Santa Marta, Colombia, allow for studies to evaluate the natural and biotechnological supply options of (+)-discodermolide. In this work, an RP-HPLC-UV methodology for the quantification of (+)-discodermolide from sponge samples was tested and validated. Our protocol for extracting this compound from the sponge included lyophilization, exhaustive methanol extraction, partitioning using water and dichloromethane, purification of the organic fraction in RP-18 cartridges and then finally retrieving the (+)-discodermolide in the methanol-water (80:20 v/v) fraction. This fraction was injected into an HPLC system with an Xterra RP-18 column and a detection wavelength of 235 nm. The calibration curve was linear, making it possible to calculate the LODs and quantification in these experiments. The intra-day and inter-day precision showed relative standard deviations lower than 5%. The accuracy, determined as the percentage recovery, was 99.4%. Nine samples of the sponge from the Bahamas, Bonaire, Curaçao and Santa Marta had concentrations of (+)-discodermolide ranging from 5.3 to 29.3 microg/g(-1) of wet sponge. This methodology is quick and simple, allowing for the quantification in sponges from natural environments, in situ cultures or dissociated cells.

A long-term validation of the modernised DC-ARC-OES solid-sample method.

Science.gov (United States)

Flórián, K; Hassler, J; Förster, O

2001-12-01

The validation procedure based on ISO 17025 standard has been used to study and illustrate both the longterm stability of the calibration process of the DC-ARC solid sample spectrometric method and the main validation criteria of the method. In the calculation of the validation characteristics depending on the linearity(calibration), also the fulfilment of predetermining criteria such as normality and homoscedasticity was checked. In order to decide whether there are any trends in the time-variation of the analytical signal or not, also the Neumann test of trend was applied and evaluated. Finally, a comparison with similar validation data of the ETV-ICP-OES method was carried out.

Study of archaeological analogs for the validation of nuclear glass long-term behavior models

International Nuclear Information System (INIS)

Verney-Carron, A.

2008-10-01

Fractured archaeological glass blocks collected from a shipwreck discovered in the Mediterranean Sea near Embiez Island (Var) were investigated because of their morphological analogy with vitrified nuclear waste and of a known and stable environment. These glasses are fractured due to a fast cooling after they were melted (like nuclear glass) and have been altered for 1800 years in seawater. This work results in the development and the validation of a geochemical model able to simulate the alteration of a fractured archaeological glass block over 1800 years. The kinetics associated with the different mechanisms (interdiffusion and dissolution) and the thermodynamic parameters of the model were determined by leaching experiments. The model implemented in HYTEC software was used to simulate crack alteration over 1800 years. The consistency between simulated alteration thicknesses and measured data on glass blocks validate the capacity of the model to predict long-term alteration. This model is able to account for the results from the characterization of crack network and its state of alteration. The cracks in the border zone are the most altered due to a fast renewal of the leaching solution, whereas internal cracks are thin because of complex interactions between glass alteration and transport of elements in solution (influence of initial crack aperture and of the crack sealing). The lowest alteration thicknesses, as well as their variability, can be explained. The analog behavior of archaeological and nuclear glasses from leaching experiments makes possible the transposition of the model to nuclear glass in geological repository. (author)

Novel inhibitors of HIV discovered among existing classes of pharmaceutical compounds indicated for unrelated clinical indications.

Science.gov (United States)

Kucherov, I I; Rytik, P G; Podol'skaya, I A; Mistryukova, L O; Korjev, M O

2009-01-01

In vitro screening of 307 drugs with various clinical indications (cardiotropic, neurotropic, antibacterial, etc.) has revealed 6 compounds which displayed remarkable antiretroviral activity. Three of these drugs had a tendency to have undesirable side effects and were thus excluded from further consideration. Remaining three, i.e., Xantinol Nicotinate, Tardiferon, and Trental may become valid candidates for inclusion into antiviral regimens such as HAART. In vitro tests have shown that xantinol and trental display synergistic effect with azidothymidine, inhibit the replication AZT-resistant strains of HIV, and have no competing undesirable activities. These compounds should be evaluated in safety studies to determine optimal doses for patients with HIV. If these studies confirm in vitro results these compounds may become valid candidates as safe and affordable means to be added into the arsenal of antiretroviral drugs.

The Dynamics Of English Terminological Compound Lexemes And Their Serbian Equivalents

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Dimković-Telebaković Gordana

2014-03-01

Full Text Available This paper discusses the conceptual dynamicity of English compound lexemes and their Serbian equivalents as reflected in compound lexemes in traffic engineering. The morphological structure and semantics of compound lexemes are considered, as well as strategies for translating English metaphorical compound lexemes into Serbian. The analysis reveals that Serbian cannot cope with the dynamic nature of traffic engineering terminology in English, and that Anglicisms, synonyms of different polysemous terms and vague conceptual determinations are characteristic of Serbian terminological equivalents

Validation of a novel device to objectively measure adherence to long-term oxygen therapy

Directory of Open Access Journals (Sweden)

Sun-Kai V Lin

2008-10-01

Full Text Available Sun-Kai V Lin1, Daniel K Bogen1, Samuel T Kuna2,31Department of Bioengineering; 2Department of Medicine, Pulmonary, Allergy and Critical Care Division, and Center for Sleep and Respiratory Neurobiology, University of Pennsylvania, Pennsylvania, USA; 3Department of Medicine, Philadelphia Veterans Affairs Medical Center Philadelphia, Pennsylvania, USARationale: We have developed a novel oxygen adherence monitor that objectively measures patient use of long-term oxygen therapy. The monitor attaches to the oxygen source and detects whether or not the patient is wearing the nasal cannula.Objective: The study’s purpose was to validate the monitor’s performance in patients with chronic obstructive pulmonary disease during wakefulness and sleep.Methods: Ten adult males with stable chronic obstructive pulmonary disease (mean ± SD FEV1 37.7 ± 14.9% of predicted on long-term continuous oxygen therapy were tested in a sleep laboratory over a 12–13 hour period that included an overnight polysomnogram.Measurements: The monitor’s measurements were obtained at 4-minute intervals and compared to actual oxygen use determined by review of time-synchronized video recordings.Main results: The monitor made 1504/1888 (79.7% correct detections (unprocessed data across all participants: 957/1,118 (85.6% correct detections during wakefulness and 546/770 (70.9% during sleep. All errors were false negatives, ie, the monitor failed to detect that the participant was actually wearing the cannula. Application of a majority-vote filter to the raw data improved overall detection accuracy to 84.9%.Conclusions: The results demonstrate the monitor’s ability to objectively measure whether or not men with chronic obstructive pulmonary disease are receiving their oxygen treatment. The ability to objectively measure oxygen delivery, rather than oxygen expended, may help improve the management of patients on long-term oxygen therapy.Keywords: chronic obstructive pulmonary

Long Term Validation of Land Surface Temperature Retrieved from MSG/SEVIRI with Continuous in-Situ Measurements in Africa

Directory of Open Access Journals (Sweden)

Frank-M. Göttsche

2016-05-01

Full Text Available Since 2005, the Land Surface Analysis Satellite Application Facility (LSA SAF operationally retrieves Land Surface Temperature (LST for the Spinning Enhanced Visible and Infrared Imager (SEVIRI on board Meteosat Second Generation (MSG. The high temporal resolution of the Meteosat satellites and their long term availability since 1977 make their data highly valuable for climate studies. In order to ensure that the LSA SAF LST product continuously meets its target accuracy of 2 °C, it is validated with in-situ measurements from four dedicated LST validation stations. Three stations are located in highly homogenous areas in Africa (semiarid bush, desert, and Kalahari semi-desert and typically provide thousands of monthly match-ups with LSA SAF LST, which are used to perform seasonally resolved validations. An uncertainty analysis performed for desert station Gobabeb yielded an estimate of total in-situ LST uncertainty of 0.8 ± 0.12 °C. Ignoring rainy seasons, the results for the period 2009–2014 show that LSA SAF LST consistently meets its target accuracy: the highest mean root-mean-square error (RMSE for LSA SAF LST over the African stations was 1.6 °C while mean absolute bias was 0.1 °C. Nighttime and daytime biases were up to 0.7 °C but had opposite signs: when evaluated together, these partially compensated each other.

Validated RP-HPLC Method for Quantification of Phenolic ...

African Journals Online (AJOL)

Purpose: To evaluate the total phenolic content and antioxidant potential of the methanol extracts of aerial parts and roots of Thymus sipyleus Boiss and also to determine some phenolic compounds using a newly developed and validated reversed phase high performance liquid chromatography (RP-HPLC) method.

A High-Content Live-Cell Viability Assay and Its Validation on a Diverse 12K Compound Screen.

Science.gov (United States)

Chiaravalli, Jeanne; Glickman, J Fraser

2017-08-01

We have developed a new high-content cytotoxicity assay using live cells, called "ImageTOX." We used a high-throughput fluorescence microscope system, image segmentation software, and the combination of Hoechst 33342 and SYTO 17 to simultaneously score the relative size and the intensity of the nuclei, the nuclear membrane permeability, and the cell number in a 384-well microplate format. We then performed a screen of 12,668 diverse compounds and compared the results to a standard cytotoxicity assay. The ImageTOX assay identified similar sets of compounds to the standard cytotoxicity assay, while identifying more compounds having adverse effects on cell structure, earlier in treatment time. The ImageTOX assay uses inexpensive commercially available reagents and facilitates the use of live cells in toxicity screens. Furthermore, we show that we can measure the kinetic profile of compound toxicity in a high-content, high-throughput format, following the same set of cells over an extended period of time.

Spin polarization in rare earth intermetallic compounds

International Nuclear Information System (INIS)

Steenwijk, F.J. van

1976-01-01

In this thesis the results of Moessbauer experiments performed on a series of intermetallic compounds of europium and gadolinium are reported. For each of these compounds the magnetic hyperfine field, the electric field gradient at the nuclear site and the isomer shift were determined. For most of the compounds the magnetic ordering temperature was also measured. For some of the europium compounds (e.g. EuAu 5 , EuAg 5 , and EuCu 5 ) it could be derived from the measurements that the easy direction of magnetization falls along the crystallographic c-axis. In a number of compounds (e.g. EuCu 5 , EuZn 5 , EuAu 2 and GdCu 5 ), the various contributions to the magnetic hyperfine field were disentangled by the investigation of suitable pseudobinary compounds that are dilute in Eu. The neighbour contribution Hsub(N) and the paramagnetic Curie temperature thetasub(p) were compared with each other in terms of the RKKY model for EuCu 5 and GdCu 5 . Since the correspondence was found to be poor it was concluded that the magnetic behaviour in these compounds cannot be described by a simple free electron picture as is the basis for the RKKY model

Characterization and validation of an in silico toxicology model to predict the mutagenic potential of drug impurities*

Energy Technology Data Exchange (ETDEWEB)

Valerio, Luis G., E-mail: luis.valerio@fda.hhs.gov [Science and Research Staff, Office of Pharmaceutical Science, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993–0002 (United States); Cross, Kevin P. [Leadscope, Inc., 1393 Dublin Road, Columbus, OH, 43215–1084 (United States)

2012-05-01

Control and minimization of human exposure to potential genotoxic impurities found in drug substances and products is an important part of preclinical safety assessments of new drug products. The FDA's 2008 draft guidance on genotoxic and carcinogenic impurities in drug substances and products allows use of computational quantitative structure–activity relationships (QSAR) to identify structural alerts for known and expected impurities present at levels below qualified thresholds. This study provides the information necessary to establish the practical use of a new in silico toxicology model for predicting Salmonella t. mutagenicity (Ames assay outcome) of drug impurities and other chemicals. We describe the model's chemical content and toxicity fingerprint in terms of compound space, molecular and structural toxicophores, and have rigorously tested its predictive power using both cross-validation and external validation experiments, as well as case studies. Consistent with desired regulatory use, the model performs with high sensitivity (81%) and high negative predictivity (81%) based on external validation with 2368 compounds foreign to the model and having known mutagenicity. A database of drug impurities was created from proprietary FDA submissions and the public literature which found significant overlap between the structural features of drug impurities and training set chemicals in the QSAR model. Overall, the model's predictive performance was found to be acceptable for screening drug impurities for Salmonella mutagenicity. -- Highlights: ► We characterize a new in silico model to predict mutagenicity of drug impurities. ► The model predicts Salmonella mutagenicity and will be useful for safety assessment. ► We examine toxicity fingerprints and toxicophores of this Ames assay model. ► We compare these attributes to those found in drug impurities known to FDA/CDER. ► We validate the model and find it has a desired predictive

Characterization and validation of an in silico toxicology model to predict the mutagenic potential of drug impurities*

International Nuclear Information System (INIS)

Valerio, Luis G.; Cross, Kevin P.

2012-01-01

Control and minimization of human exposure to potential genotoxic impurities found in drug substances and products is an important part of preclinical safety assessments of new drug products. The FDA's 2008 draft guidance on genotoxic and carcinogenic impurities in drug substances and products allows use of computational quantitative structure–activity relationships (QSAR) to identify structural alerts for known and expected impurities present at levels below qualified thresholds. This study provides the information necessary to establish the practical use of a new in silico toxicology model for predicting Salmonella t. mutagenicity (Ames assay outcome) of drug impurities and other chemicals. We describe the model's chemical content and toxicity fingerprint in terms of compound space, molecular and structural toxicophores, and have rigorously tested its predictive power using both cross-validation and external validation experiments, as well as case studies. Consistent with desired regulatory use, the model performs with high sensitivity (81%) and high negative predictivity (81%) based on external validation with 2368 compounds foreign to the model and having known mutagenicity. A database of drug impurities was created from proprietary FDA submissions and the public literature which found significant overlap between the structural features of drug impurities and training set chemicals in the QSAR model. Overall, the model's predictive performance was found to be acceptable for screening drug impurities for Salmonella mutagenicity. -- Highlights: ► We characterize a new in silico model to predict mutagenicity of drug impurities. ► The model predicts Salmonella mutagenicity and will be useful for safety assessment. ► We examine toxicity fingerprints and toxicophores of this Ames assay model. ► We compare these attributes to those found in drug impurities known to FDA/CDER. ► We validate the model and find it has a desired predictive performance.

Efficacy of bioactive compounds from extra virgin olive oil to modulate atherosclerosis development.

Science.gov (United States)

Lou-Bonafonte, José M; Arnal, Carmen; Navarro, María A; Osada, Jesús

2012-07-01

As olive oil is the main source of calories in the Mediterranean diet, a great deal of research has been devoted to characterizing its role in atherosclerosis. Virgin olive oil is an oily matrix that contains hydrocarbons, mainly squalene; triterpenes such as uvaol, erythrodiol, oleanolic, and maslinic acid; phytosterols; and a wide range of phenolic compounds comprising simple phenols, flavonoids, secoiridoids, and lignans. In this review, we analyze the studies dealing with atherosclerosis and olive oil in several species. A protective role of virgin olive oil against atherosclerosis has been shown in ApoE-deficient mice and hamsters. In the former animal, sex, dose, and dietary cholesterol are modulators of the outcome. Contradictory findings have been reported for rabbits, a circumstance that could be due to the profusion of experimental designs, differing in terms of doses and animal strains, as well as sources of olive oils. This role has yet to be fully validated in humans. Minor components of olive oil have been shown to be involved in atherosclerosis protection. Nevertheless, evidence of the potential of isolated compounds or the right combination of them to achieve the antiatherosclerotic effect of virgin olive oil is inconclusive and will undoubtedly require further experimental support. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Validation of an in vitro contractility assay using canine ventricular myocytes

Energy Technology Data Exchange (ETDEWEB)

Harmer, A.R., E-mail: alex.harmer@astrazeneca.com; Abi-Gerges, N.; Morton, M.J.; Pullen, G.F.; Valentin, J.P.; Pollard, C.E.

2012-04-15

Measurement of cardiac contractility is a logical part of pre-clinical safety assessment in a drug discovery project, particularly if a risk has been identified or is suspected based on the primary- or non-target pharmacology. However, there are limited validated assays available that can be used to screen several compounds in order to identify and eliminate inotropic liability from a chemical series. We have therefore sought to develop an in vitro model with sufficient throughput for this purpose. Dog ventricular myocytes were isolated using a collagenase perfusion technique and placed in a perfused recording chamber on the stage of a microscope at ∼ 36 °C. Myocytes were stimulated to contract at a pacing frequency of 1 Hz and a digital, cell geometry measurement system (IonOptix™) was used to measure sarcomere shortening in single myocytes. After perfusion with vehicle (0.1% DMSO), concentration–effect curves were constructed for each compound in 4–30 myocytes taken from 1 or 2 dog hearts. The validation test-set was 22 negative and 8 positive inotropes, and 21 inactive compounds, as defined by their effect in dog, cynolomolgous monkey or humans. By comparing the outcome of the assay to the known in vivo contractility effects, the assay sensitivity was 81%, specificity was 75%, and accuracy was 78%. With a throughput of 6–8 compounds/week from 1 cell isolation, this assay may be of value to drug discovery projects to screen for direct contractility effects and, if a hazard is identified, help identify inactive compounds. -- Highlights: ► Cardiac contractility is an important physiological function of the heart. ► Assessment of contractility is a logical part of pre-clinical drug safety testing. ► There are limited validated assays that predict effects of compounds on contractility. ► Using dog myocytes, we have developed an in vitro cardiac contractility assay. ► The assay predicted the in vivo contractility with a good level of accuracy.

Development of fluorescence imaging-based assay for screening cardioprotective compounds from medicinal plants.

Science.gov (United States)

Wang, Yi; Zhao, Xiaoping; Gao, Xiumei; Nie, Xiaojing; Yang, Yingxin; Fan, Xiaohui

2011-09-19

Medicinal plants have been widely recognized as a renewable resource for the discovery of novel leads and drug. In this study, an approach for screening and identification compounds with cardioprotective activity from medicinal plant extracts by cellular-fluorescence imaging technique was developed. It is a cell-based assay for measuring mitochondrial membrane potential changes in H9c2 cardiac muscle cells exposed to H(2)O(2) by using a fluorescence automatic microscopy screening platform. Rhodamine 123 was used as the fluorescent dye to indicate the change of mitochondrial membrane potential. The sensitivity and linear range of the proposed approach were evaluated and validated using vitamin C, an antioxidative compound. The method was applied to screen active components with potent cardioprotective effects from a traditional Chinese formula. The potential cardioprotective components were identified by liquid chromatography coupled with mass spectrometry (LC/MS). Moreover, the utility of the proposed approach was further validated by three compounds (salvianolic acid B, protocatechuic aldehyde, and tanshinone II A) identified from the formula which showed cardioprotective effects in a dose-dependent manner. These applications suggested that the proposed rapid and sensitive screening approach offers an efficient way to discover active components or compounds from medicinal plants. Copyright © 2011 Elsevier B.V. All rights reserved.

Just-in-Time Compound Pooling Increases Primary Screening Capacity without Compromising Screening Quality.

Science.gov (United States)

Elkin, L L; Harden, D G; Saldanha, S; Ferguson, H; Cheney, D L; Pieniazek, S N; Maloney, D P; Zewinski, J; O'Connell, J; Banks, M

2015-06-01

Compound pooling, or multiplexing more than one compound per well during primary high-throughput screening (HTS), is a controversial approach with a long history of limited success. Many issues with this approach likely arise from long-term storage of library plates containing complex mixtures of compounds at high concentrations. Due to the historical difficulties with using multiplexed library plates, primary HTS often uses a one-compound-one-well approach. However, as compound collections grow, innovative strategies are required to increase the capacity of primary screening campaigns. Toward this goal, we have developed a novel compound pooling method that increases screening capacity without compromising data quality. This method circumvents issues related to the long-term storage of complex compound mixtures by using acoustic dispensing to enable "just-in-time" compound pooling directly in the assay well immediately prior to assay. Using this method, we can pool two compounds per well, effectively doubling the capacity of a primary screen. Here, we present data from pilot studies using just-in-time pooling, as well as data from a large >2-million-compound screen using this approach. These data suggest that, for many targets, this method can be used to vastly increase screening capacity without significant reduction in the ability to detect screening hits. © 2015 Society for Laboratory Automation and Screening.

Application of GC-MS for the detection of lipophilic compounds in diverse plant tissues

Directory of Open Access Journals (Sweden)

Hellmann Hanjo

2009-04-01

Full Text Available Abstract Background The concept of metabolite profiling has been around for decades and technical innovations are now enabling it to be carried out on a large scale with respect to the number of both metabolites measured and experiments carried out. However, studies are generally confined to polar compounds alone. Here we describe a simple method for lipophilic compounds analysis in various plant tissues. Results We choose the same preparative and instrumental platform for lipophilic profiling as that we routinely use for polar metabolites measurements. The method was validated in terms of linearity, carryover, reproducibility and recovery rates, as well as using various plant tissues. As a first case study we present metabolic profiling of Arabidopsis root and shoot tissue of wild type (C24 and mutant (rsr4-1 plants deficient on vitamin B6. We found significant alterations in lipid constituent contents, especially in the roots, which were characterised by dramatic increases in several fatty acids, thus providing further hint for the role of pyridoxine in oxidative stress and lipid peroxidation. The second example is the lipophilic profiling of red and green tomato fruit cuticles of wild type (Alisa Craig and the DFD (delayed fruit deterioration mutant, which we compared and contrasted with the more focused wax analysis of these plants reported before. Conclusion We can rapidly and reliably detect and quantify over 40 lipophilic metabolites including fatty acids, fatty alcohols, alkanes, sterols and tocopherols. The method presented here affords a simple and rapid, yet robust complement to previously validated methods of polar metabolite profiling by gas-chromatography mass-spectrometry.

Large positive magnetoresistance in intermetallic compound NdCo2Si2

Science.gov (United States)

Roy Chowdhury, R.; Dhara, S.; Das, I.; Bandyopadhyay, B.; Rawat, R.

2018-04-01

The magnetic, magneto-transport and magnetocaloric properties of antiferromagnetic intermetallic compound NdCo2Si2 (TN = 32K) have been studied. The compound yields a positive magnetoresistance (MR) of about ∼ 123 % at ∼ 5K in 8 T magnetic field. The MR value is significantly large vis - a - vis earlier reports of large MR in intermetallic compounds, and possibly associated with the changes in magnetic structure of the compound. The large MR value can be explained in terms of field induced pseudo-gaps on Fermi surface.

Developing a Validated Long-Term Satellite-Based Albedo Record in the Central Alaska Range to Improve Regional Hydroclimate Reconstructions

Science.gov (United States)

Kreutz, K. J.; Godaire, T. P.; Burakowski, E. A.; Winski, D.; Campbell, S. W.; Wang, Z.; Sun, Q.; Hamilton, G. S.; Birkel, S. D.; Wake, C. P.; Osterberg, E. C.; Schaaf, C.

2015-12-01

Mountain glaciers around the world, particularly in Alaska, are experiencing significant surface mass loss from rapid climatic shifts and constitute a large proportion of the cryosphere's contribution to sea level rise. Surface albedo acts as a primary control on a glacier's mass balance, yet it is difficult to measure and quantify spatially and temporally in steep, mountainous settings. During our 2013 field campaign in Denali National Park to recover two surface to bedrock ice cores, we used an Analytical Spectral Devices (ASD) FieldSpec4 Standard Resolution spectroradiometer to measure incoming solar radiation, outgoing surface reflectance and optical grain size on the Kahiltna Glacier and at the Kahiltna Base Camp. A Campbell Scientific automatic weather station was installed on Mount Hunter (3900m) in June 2013, complementing a longer-term (2008-present) station installed at Kahiltna Base Camp (2100m). Use of our in situ data aids in the validation of surface albedo values derived from Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat satellite imagery. Comparisons are made between ASD FieldSpec4 ground measurements and 500m MODIS imagery to assess the ability of MODIS to capture the variability of surface albedo across the glacier surface. The MODIS MCD43A3 BRDF/Albedo Product performs well at Kahiltna Base Camp (albedo (10-28% relative to ASD data) appear to occur along the Kahiltna Glacier due to the snow-free valley walls being captured in the 500m MODIS footprint. Incorporating Landsat imagery will strengthen our interpretations and has the potential to produce a long-term (1982-present) validated satellite albedo record for steep and mountainous terrain. Once validation is complete, we will compare the satellite-derived albedo record to the Denali ice core accumulation rate, aerosol records (i.e. volcanics and biomass burning), and glacier mass balance data. This research will ultimately contribute to an improved understanding of the

Validation of a motor activity system by a robotically controlled vehicle and using standard reference compounds.

Science.gov (United States)

Patterson, John P; Markgraf, Carrie G; Cirino, Maria; Bass, Alan S

2005-01-01

A series of experiments were undertaken to evaluate the accuracy, precision, specificity, and sensitivity of an automated, infrared photo beam-based open field motor activity system, the MotorMonitor v. 4.01, Hamilton-Kinder, LLC, for use in a good laboratory practices (GLP) Safety Pharmacology laboratory. This evaluation consisted of two phases: (1) system validation, employing known inputs using the EM-100 Controller Photo Beam Validation System, a robotically controlled vehicle representing a rodent and (2) biologic validation, employing groups of rats treated with the standard pharmacologic agents diazepam or D-amphetamine. The MotorMonitor's parameters that described the open-field activity of a subject were: basic movements, total distance, fine movements, x/y horizontal ambulations, rearing, and total rest time. These measurements were evaluated over a number of zones within each enclosure. System validation with the EM-100 Controller Photo Beam Validation System showed that all the parameters accurately and precisely measured what they were intended to measure, with the exception of fine movements and x/y ambulations. Biologic validation using the central nervous system depressant diazepam at 1, 2, or 5 mg/kg, i.p. produced the expected dose-dependent reduction in rat motor activity. In contrast, the central nervous system stimulant D-amphetamine produced the expected increases in rat motor activity at 0.1 and 1 mg/kg, i.p, demonstrating the specificity and sensitivity of the system. Taken together, these studies of the accuracy, precision, specificity, and sensitivity show the importance of both system and biologic validation in the evaluation of an automated open field motor activity system for use in a GLP compliant laboratory.

Atom-type-based AI topological descriptors: application in structure-boiling point correlations of oxo organic compounds.

Science.gov (United States)

Ren, Biye

2003-01-01

Structure-boiling point relationships are studied for a series of oxo organic compounds by means of multiple linear regression (MLR) analysis. Excellent MLR models based on the recently introduced Xu index and the atom-type-based AI indices are obtained for the two subsets containing respectively 77 ethers and 107 carbonyl compounds and a combined set of 184 oxo compounds. The best models are tested using the leave-one-out cross-validation and an external test set, respectively. The MLR model produces a correlation coefficient of r = 0.9977 and a standard error of s = 3.99 degrees C for the training set of 184 compounds, and r(cv) = 0.9974 and s(cv) = 4.16 degrees C for the cross-validation set, and r(pred) = 0.9949 and s(pred) = 4.38 degrees C for the prediction set of 21 compounds. For the two subsets containing respectively 77 ethers and 107 carbonyl compounds, the quality of the models is further improved. The standard errors are reduced to 3.30 and 3.02 degrees C, respectively. Furthermore, the results obtained from this study indicate that the boiling points of the studied oxo compound dominantly depend on molecular size and also depend on individual atom types, especially oxygen heteroatoms in molecules due to strong polar interactions between molecules. These excellent structure-boiling point models not only provide profound insights into the role of structural features in a molecule but also illustrate the usefulness of these indices in QSPR/QSAR modeling of complex compounds.

Validity of the RAI-MDS for ascertaining diabetes and comorbid conditions in long-term care facility residents.

Science.gov (United States)

Lix, Lisa M; Yan, Lin; Blackburn, David; Hu, Nianping; Schneider-Lindner, Verena; Teare, Gary F

2014-01-15

This study assessed the validity of the Resident Assessment Instrument Minimum Data Set (RAI-MDS) Version 2.0 for diagnoses of diabetes and comorbid conditions in residents of long-term care facilities (LTCFs). Hospital inpatient, outpatient physician billing, RAI-MDS, and population registry data for 1997 to 2011 from Saskatchewan, Canada were used to ascertain cases of diabetes and 12 comorbid conditions. Prevalence estimates were calculated for both RAI-MDS and administrative health data. Sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were calculated using population-based administrative health data as the validation data source. Cohen's κ was used to estimate agreement between the two data sources. 23,217 LTCF residents were in the diabetes case ascertainment cohort. Diabetes prevalence was 25.3% in administrative health data and 21.9% in RAI-MDS data. Overall sensitivity of a RAI-MDS diabetes diagnoses was 0.79 (95% CI: 0.79, 0.80) and the PPV was 0.92 (95% CI: 0.91, 0.92), when compared to administrative health data. Sensitivity of the RAI-MDS for ascertaining comorbid conditions ranged from 0.21 for osteoporosis to 0.92 for multiple sclerosis; specificity was high for most conditions. RAI-MDS clinical assessment data are sensitive to ascertain diabetes cases in LTCF populations when compared to administrative health data. For many comorbid conditions, RAI-MDS data have low validity when compared to administrative data. Risk-adjustment measures based on these comorbidities might not produce consistent results for RAI-MDS and administrative health data, which could affect the conclusions of studies about health outcomes and quality of care across facilities.

Use of short-term test systems for the prediction of the hazard represented by potential chemical carcinogens

Energy Technology Data Exchange (ETDEWEB)

Glass, L.R.; Jones, T.D.; Easterly, C.E.; Walsh, P.J.

1990-10-01

It has been hypothesized that results from short-term bioassays will ultimately provide information that will be useful for human health hazard assessment. Historically, the validity of the short-term tests has been assessed using the framework of the epidemiologic/medical screens. In this context, the results of the carcinogen (long-term) bioassay is generally used as the standard. However, this approach is widely recognized as being biased and, because it employs qualitative data, cannot be used to assist in isolating those compounds which may represent a more significant toxicologic hazard than others. In contrast, the goal of this research is to address the problem of evaluating the utility of the short-term tests for hazard assessment using an alternative method of investigation. Chemicals were selected mostly from the list of carcinogens published by the International Agency for Research on Carcinogens (IARC); a few other chemicals commonly recognized as hazardous were included. Tumorigenicity and mutagenicity data on 52 chemicals were obtained from the Registry of Toxic Effects of Chemical Substances (RTECS) and were analyzed using a relative potency approach. The data were evaluated in a format which allowed for a comparison of the ranking of the mutagenic relative potencies of the compounds (as estimated using short-term data) vs. the ranking of the tumorigenic relative potencies (as estimated from the chronic bioassays). Although this was a preliminary investigation, it offers evidence that the short-term tests systems may be of utility in ranking the hazards represented by chemicals which may contribute to increased carcinogenesis in humans as a result of occupational or environmental exposures. 177 refs., 8 tabs.

Use of short-term test systems for the prediction of the hazard represented by potential chemical carcinogens

International Nuclear Information System (INIS)

Glass, L.R.; Jones, T.D.; Easterly, C.E.; Walsh, P.J.

1990-10-01

It has been hypothesized that results from short-term bioassays will ultimately provide information that will be useful for human health hazard assessment. Historically, the validity of the short-term tests has been assessed using the framework of the epidemiologic/medical screens. In this context, the results of the carcinogen (long-term) bioassay is generally used as the standard. However, this approach is widely recognized as being biased and, because it employs qualitative data, cannot be used to assist in isolating those compounds which may represent a more significant toxicologic hazard than others. In contrast, the goal of this research is to address the problem of evaluating the utility of the short-term tests for hazard assessment using an alternative method of investigation. Chemicals were selected mostly from the list of carcinogens published by the International Agency for Research on Carcinogens (IARC); a few other chemicals commonly recognized as hazardous were included. Tumorigenicity and mutagenicity data on 52 chemicals were obtained from the Registry of Toxic Effects of Chemical Substances (RTECS) and were analyzed using a relative potency approach. The data were evaluated in a format which allowed for a comparison of the ranking of the mutagenic relative potencies of the compounds (as estimated using short-term data) vs. the ranking of the tumorigenic relative potencies (as estimated from the chronic bioassays). Although this was a preliminary investigation, it offers evidence that the short-term tests systems may be of utility in ranking the hazards represented by chemicals which may contribute to increased carcinogenesis in humans as a result of occupational or environmental exposures. 177 refs., 8 tabs

Two-dimensional materials from high-throughput computational exfoliation of experimentally known compounds

Science.gov (United States)

Mounet, Nicolas; Gibertini, Marco; Schwaller, Philippe; Campi, Davide; Merkys, Andrius; Marrazzo, Antimo; Sohier, Thibault; Castelli, Ivano Eligio; Cepellotti, Andrea; Pizzi, Giovanni; Marzari, Nicola

2018-02-01

Two-dimensional (2D) materials have emerged as promising candidates for next-generation electronic and optoelectronic applications. Yet, only a few dozen 2D materials have been successfully synthesized or exfoliated. Here, we search for 2D materials that can be easily exfoliated from their parent compounds. Starting from 108,423 unique, experimentally known 3D compounds, we identify a subset of 5,619 compounds that appear layered according to robust geometric and bonding criteria. High-throughput calculations using van der Waals density functional theory, validated against experimental structural data and calculated random phase approximation binding energies, further allowed the identification of 1,825 compounds that are either easily or potentially exfoliable. In particular, the subset of 1,036 easily exfoliable cases provides novel structural prototypes and simple ternary compounds as well as a large portfolio of materials to search from for optimal properties. For a subset of 258 compounds, we explore vibrational, electronic, magnetic and topological properties, identifying 56 ferromagnetic and antiferromagnetic systems, including half-metals and half-semiconductors.

Antiosteoporotic compounds from seeds of Cuscuta chinensis.

Science.gov (United States)

Yang, Lijuan; Chen, Qianfeng; Wang, Fei; Zhang, Guolin

2011-05-17

The seeds of Cuscuta chinensis (Tu-Si-Zi, TSZ) have long been used for the treatment of osteoporosis in China and some Asian countries. The compounds in TSZ responsible for the antiosteoporotic activity are still poorly understood. The present study was designed to investigate the osteogenic compounds in TSZ, and to evaluate their antiosteoporotic effects in osteoblastic cells. Osteoblast-like UMR-106 cells were used for bioactivity-guided isolation of the active compounds. The activity of alkaline phosphatase (ALP) in UMR-106 cells was measured by p-nitrophenyl sodium phosphate assay. The proliferation of UMR-106 cells was assayed by Alamar-Blue method. Estrogenic activity of the extracts and isolated compounds was evaluated by activation of estrogen response element (ERE) luciferase reporter expression in HeLa cells co-transfected with human estrogen receptor subtypes (ERα or ERβ) expression vectors and 5×ERE luciferase reporter plasmid. Antiestrogenic activity of the extracts and isolated compounds were evaluated by activation of activator protein-1 (AP-1) luciferase reporter expression in HeLa cells co-transfected with human estrogen receptor subtypes (ERα or ERβ) expression vectors and 6×AP-1 luciferase reporter plasmid. ALP-guided fractionation led to the isolation of five known flavonoids, quercetin, kaempferol, isorhamnetin, hyperoside and astragalin from the crude ethanolic extract of TSZ. Further study showed that kaempferol and hyperoside significantly increased the ALP activity in UMR-106 cells. Astragalin promoted the proliferation of UMR-106 cells whereas other compounds had no such effect. The isolated compounds showed estrogenic activity but quercetin, kaempferol and isorhamnetin showed more potent ERβ agonist activity. However, compared with their ER agonist activity, only quercetin and kaempferol showed potent ER antagonist activity by activating ERα/β-mediated AP-1 reporter expression. Our findings validated the clinical use of TSZ in

SEURAT-1 liver gold reference compounds: a mechanism-based review.

Science.gov (United States)

Jennings, Paul; Schwarz, Michael; Landesmann, Brigitte; Maggioni, Silvia; Goumenou, Marina; Bower, David; Leonard, Martin O; Wiseman, Jeffrey S

2014-12-01

There is an urgent need for the development of alternative methods to replace animal testing for the prediction of repeat dose chemical toxicity. To address this need, the European Commission and Cosmetics Europe have jointly funded a research program for 'Safety Evaluation Ultimately Replacing Animal Testing.' The goal of this program was the development of in vitro cellular systems and associated computational capabilities for the prediction of hepatic, cardiac, renal, neuronal, muscle, and skin toxicities. An essential component of this effort is the choice of appropriate reference compounds that can be used in the development and validation of assays. In this review, we focus on the selection of reference compounds for liver pathologies in the broad categories of cytotoxicity and lipid disorders. Mitochondrial impairment, oxidative stress, and apoptosis are considered under the category of cytotoxicity, while steatosis, cholestasis, and phospholipidosis are considered under the category of lipid dysregulation. We focused on four compound classes capable of initiating such events, i.e., chemically reactive compounds, compounds with specific cellular targets, compounds that modulate lipid regulatory networks, and compounds that disrupt the plasma membrane. We describe the molecular mechanisms of these compounds and the cellular response networks which they elicit. This information will be helpful to both improve our understanding of mode of action and help in the selection of appropriate mechanistic biomarkers, allowing us to progress the development of animal-free models with improved predictivity to the human situation.

Staff preparedness for providing palliative and end-of-life care in long-term care homes: Instrument development and validation.

Science.gov (United States)

Chan, Helen Yl; Chun, Gloria Km; Man, C W; Leung, Edward Mf

2018-05-01

Although much attention has been on integrating the palliative care approach into services of long-term care homes for older people living with frailty and progressive diseases, little is known about the staff preparedness for these new initiatives. The present study aimed to develop and test the psychometric properties of an instrument for measuring care home staff preparedness in providing palliative and end-of-life care. A 16-item instrument, covering perceived knowledge, skill and psychological readiness, was developed. A total of 247 staff members of different ranks from four care homes participated in the study. Exploratory factor analysis using the principal component analysis extraction method with varimax rotation was carried out for initial validation. Known group comparison was carried out to examine its discriminant validity. Reliability of the instrument was assessed based on test-retest reliability of a subsample of 20 participants and the Cronbach's alpha of the items. Exploratory factor analysis showed that the instrument yielded a three-factor solution, which cumulatively accounted for 68.5% of the total variance. Three subscales, namely, willingness, capability and resilience, showed high internal consistency and test-retest reliability. It also showed good discriminant validity between staff members of professional and non-professional groups. This is a brief, valid and reliable scale for measuring care home staff preparedness for providing palliative and end-of-life care. It can be used to identify their concerns and training needs in providing palliative and end-of-life care, and as an outcome measure to evaluate the effects of interventional studies for capacity building in this regard. Geriatr Gerontol Int 2018; 18: 745-749. © 2018 Japan Geriatrics Society.

Analysis of antioxidative phenolic compounds in artichoke (Cynara scolymus L.).

Science.gov (United States)

Wang, Mingfu; Simon, James E; Aviles, Irma Fabiola; He, Kan; Zheng, Qun-Yi; Tadmor, Yaakov

2003-01-29

Artichoke leaf is an herbal medicine known for a long time. A systematic antioxidant activity-directed fractionation procedure was used to purify antioxidative components from the aqueous methanol extractions of artichoke heads and leaves in this study. Seven active polyphenolic compounds were purified from artichoke, and structural elucidation of each was achieved using MS and NMR. Two of these compounds, apigenin-7-rutinoside and narirutin, were found to be unique to artichoke heads, this represents the first report of these compounds in the edible portion of this plant. The contents of these antioxidants and total phenols in dried artichoke samples from leaves and immature and mature heads of three varieties, Imperial Star, Green Globe, and Violet, were then analyzed and compared by colorimetric and validated HPLC methods. Significant differences by variety and plant organ were observed.

Volatile organic compounds in urban atmospheres: Long-term measurements of ambient air concentrations in differently loaded regions of Leipzig

Energy Technology Data Exchange (ETDEWEB)

Knobloch, T.; Asperger, A.; Engewald, W. [University of Leipzig, Institute of Analytical Chemistry, Leipzig (Germany)

1997-09-01

For the comprehensive characterization of ambient air concentrations of a broad spectrum of volatile organic compounds (VOCs) an analytical method is described, consisting of adsorptive enrichment, thermal desorption without cryofocusing, and capillary gas chromatographic separation. The method was applied during two-week measuring campaigns in winter and summer 1995, and in the winter of 1996. Long-term sampling was carried out at sampling points in residential areas in the suburbs and near the city center of Leipzig. About 70 VOCs - mainly hydrocarbons from propene to hexadecane - were identified both by GC-MS and chromatographic retention data and quantified after external calibration. Mean values of VOC concentrations obtained during the sampling periods are reported and discussed with regard to the topographical location of the sampling points in the Leipzig area, seasonal variations, and possible emission sources. (orig.) With 7 figs., 3 tabs., 18 refs.

Identification, isolation and characterization of active compounds from the Indian green mussels to develop drugs

Digital Repository Service at National Institute of Oceanography (India)

in potency. This compound has been termed as (NIO-5). A compound (NIO-6) has been characterized for tuberculosis. To improve upon this, we have prepared and tested several analogues of this compound. Now we have an analogue that displays between 10 to 20...

Validation of QuEChERS analytical technique for organochlorines and synthetic pyrethroids in fruits and vegetables using GC-ECD.

Science.gov (United States)

Dubey, J K; Patyal, S K; Sharma, Ajay

2018-03-19

In the present day scenario of increasing awareness and concern about the pesticides, it is very important to ensure the quality of data being generated in pesticide residue analysis. To impart confidence in the products, terms like quality assurance and quality control are used as an integral part of quality management. In order to ensure better quality of results in pesticide residue analysis, validation of analytical methods to be used is extremely important. Keeping in view the importance of validation of method, the validation of QuEChERS (quick, easy, cheap, effective, rugged, and safe) a multiresidue method for extraction of 13 organochlorines and seven synthetic pyrethroids in fruits and vegetables followed by GC ECD for quantification was done so as to use this method for analysis of samples received in the laboratory. The method has been validated as per the Guidelines issued by SANCO (French words Sante for Health and Consommateurs for Consumers) in accordance with their document SANCO/XXXX/2013. Various parameters analyzed, viz., linearity, specificity, repeatability, reproducibility, and ruggedness were found to have acceptable values with a per cent RSD of less than 10%. Limit of quantification (LOQ) for the organochlorines was established to be 0.01 and 0.05 mg kg -1 for the synthetic pyrethroids. The uncertainty of the measurement (MU) for all these compounds ranged between 1 and 10%. The matrix-match calibration was used to compensate the matrix effect on the quantification of the compounds. The overall recovery of the method ranged between 80 and 120%. These results demonstrate the applicability and acceptability of this method in routine estimation of pesticide residues of these 20 pesticides in the fruits and vegetables by the laboratory.

Joy and flustration with organofluorine compounds - a fluorous autobiography.

Science.gov (United States)

Seebach, Dieter

2014-01-01

An overview is given about our work on fluoro-organic compounds, published or described in PhD theses between 1977 and 2013. After a discussion of structural F-effects and F-tagging applications the material is ordered by the various areas of our research, in which we have used and/or prepared F-derivatives: Li- and Ti-organic compounds and reagents, polylithiated hydroxy-esters and nitroalkanes, the enantiopure trifluoro-lactic, -Roche, and -3-hydroxy-butanoic acids as toolbox for the preparation of numerous F₃C-substituted compounds, including natural products and dendrimers, and fluoro-α-, -β-, and -δ-amino acids, as well as peptides with back-bond-bound fluorine. The strong influence on β-peptide folding by fluoro-substituents in the α-position of β-amino-acid residues is discussed in terms of the α-fluoro-amide conformational effect. Finally, some cases of totally unexpected effects on reactivity and structure exerted by fluoro-substitution are presented and taken as examples for our use of the terms flustrate and flustration in connection with organo-fluorine chemistry.

Comparison of Multiple Linear Regressions and Neural Networks based QSAR models for the design of new antitubercular compounds.

Science.gov (United States)

Ventura, Cristina; Latino, Diogo A R S; Martins, Filomena

2013-01-01

The performance of two QSAR methodologies, namely Multiple Linear Regressions (MLR) and Neural Networks (NN), towards the modeling and prediction of antitubercular activity was evaluated and compared. A data set of 173 potentially active compounds belonging to the hydrazide family and represented by 96 descriptors was analyzed. Models were built with Multiple Linear Regressions (MLR), single Feed-Forward Neural Networks (FFNNs), ensembles of FFNNs and Associative Neural Networks (AsNNs) using four different data sets and different types of descriptors. The predictive ability of the different techniques used were assessed and discussed on the basis of different validation criteria and results show in general a better performance of AsNNs in terms of learning ability and prediction of antitubercular behaviors when compared with all other methods. MLR have, however, the advantage of pinpointing the most relevant molecular characteristics responsible for the behavior of these compounds against Mycobacterium tuberculosis. The best results for the larger data set (94 compounds in training set and 18 in test set) were obtained with AsNNs using seven descriptors (R(2) of 0.874 and RMSE of 0.437 against R(2) of 0.845 and RMSE of 0.472 in MLRs, for test set). Counter-Propagation Neural Networks (CPNNs) were trained with the same data sets and descriptors. From the scrutiny of the weight levels in each CPNN and the information retrieved from MLRs, a rational design of potentially active compounds was attempted. Two new compounds were synthesized and tested against M. tuberculosis showing an activity close to that predicted by the majority of the models. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Biodegradable compounds: Rheological, mechanical and thermal properties

Science.gov (United States)

Nobile, Maria Rossella; Lucia, G.; Santella, M.; Malinconico, M.; Cerruti, P.; Pantani, R.

2015-12-01

Recently great attention from industry has been focused on biodegradable polyesters derived from renewable resources. In particular, PLA has attracted great interest due to its high strength and high modulus and a good biocompatibility, however its brittleness and low heat distortion temperature (HDT) restrict its wide application. On the other hand, Poly(butylene succinate) (PBS) is a biodegradable polymer with a low tensile modulus but characterized by a high flexibility, excellent impact strength, good thermal and chemical resistance. In this work the two aliphatic biodegradable polyesters PBS and PLA were selected with the aim to obtain a biodegradable material for the industry of plastic cups and plates. PBS was also blended with a thermoplastic starch. Talc was also added to the compounds because of its low cost and its effectiveness in increasing the modulus and the HDT of polymers. The compounds were obtained by melt compounding in a single screw extruder and the rheological, mechanical and thermal properties were investigated. The properties of the two compounds were compared and it was found that the values of the tensile modulus and elongation at break measured for the PBS/PLA/Talc compound make it interesting for the production of disposable plates and cups. In terms of thermal resistance the compounds have HDTs high enough to contain hot food or beverages. The PLA/PBS/Talc compound can be, then, considered as biodegradable substitute for polystyrene for the production of disposable plates and cups for hot food and beverages.

Cyclooxygenase inhibitory compounds from Gymnosporia heterophylla aerial parts.

Science.gov (United States)

Ochieng, Charles O; Opiyo, Sylvia A; Mureka, Edward W; Ishola, Ismail O

2017-06-01

Gymnosporia heterophylla (Celastraceae) is an African medicinal plants used to treat painful and inflammatory diseases with partial scientific validation. Solvent extractions followed by repeated chromatographic purification of the G. heterophylla aerial parts led to the isolation of one new β-dihydroagarofuran sesquiterpene alkaloid (1), and two triterpenes (2-3). In addition, eight known compounds including one β-dihydroagarofuran sesquiterpene alkaloid (4), and six triterpenes (5-10) were isolated. All structures were determined through extensive analysis of the NMR an MS data as well as by comparison with literature data. These compounds were evaluated for the anti-inflammatory activities against COX-1 and -2 inhibitory potentials. Most of the compound isolated showed non selective COX inhibitions except for 3-Acetoxy-1β-hydroxyLupe-20(29)-ene (5), Lup-20(29)-ene-1β,3β-diol (6) which showed COX-2 selective inhibition at 0.54 (1.85), and 0.45 (2.22) IC 50 , in mM (Selective Index), respectively. The results confirmed the presence of anti-inflammatory compounds in G. heterophylla which are important indicators for development of complementary medicine for inflammatory reactions; however, few could be useful as selective COX-2 inhibitor. Copyright © 2017 Elsevier B.V. All rights reserved.

Gamma transitions between compound states in spherical nuclei

International Nuclear Information System (INIS)

Kadmenskij, S.G.; Markushev, V.P.; Furman, V.I.

1980-01-01

Average values of the reduced γ widths and their dispersions are investigated, basing on the Wigner statistical matrix method, for γ transitions from a compound state c into a less-energy excited state f of an arbitrary complexity in spherical nuclei. It is shown that in all the cases of practical interest the Porter-Thomas distribution is valid for the γ widths. It is found that in the γ transitions between compound states c and c' with Esub(γ) <= 2 MeV the dominating role is played by the M1 transitions due to the main multiquasiparticle states of c, and by the E1 transitions, due to small components of the state c. In framework of the existent theoretical schemes it is shown that the strength functions of the M1 and E1 transitions between the compound states with Esub(γ) <2 MeV are close. It is deduced thet the variant of the M1 transitions is preferable in view of the experimental results on the (n, γα) reactions induced by thermal and resonance neutrons

Prediction of short-term and long-term VOC emissions from SBR bitumen-backed carpet under different temperatures

NARCIS (Netherlands)

Yang, X.; Chen, Q.; Bluyssen, P.M.

1998-01-01

This paper presents two models for volatile organic compound (VOC) emissions from carpet. One is a numerical model using the computational fluid dynamics (CFD) tech-nique for short-term predictions, the other an analytical model for long-term predictions. The numerical model can (1) deal with

Determination of the n-octanol/water partition coefficients of weakly ionizable basic compounds by reversed-phase high-performance liquid chromatography with neutral model compounds.

Science.gov (United States)

Liang, Chao; Han, Shu-ying; Qiao, Jun-qin; Lian, Hong-zhen; Ge, Xin

2014-11-01

A strategy to utilize neutral model compounds for lipophilicity measurement of ionizable basic compounds by reversed-phase high-performance liquid chromatography is proposed in this paper. The applicability of the novel protocol was justified by theoretical derivation. Meanwhile, the linear relationships between logarithm of apparent n-octanol/water partition coefficients (logKow '') and logarithm of retention factors corresponding to the 100% aqueous fraction of mobile phase (logkw ) were established for a basic training set, a neutral training set and a mixed training set of these two. As proved in theory, the good linearity and external validation results indicated that the logKow ''-logkw relationships obtained from a neutral model training set were always reliable regardless of mobile phase pH. Afterwards, the above relationships were adopted to determine the logKow of harmaline, a weakly dissociable alkaloid. As far as we know, this is the first report on experimental logKow data for harmaline (logKow = 2.28 ± 0.08). Introducing neutral compounds into a basic model training set or using neutral model compounds alone is recommended to measure the lipophilicity of weakly ionizable basic compounds especially those with high hydrophobicity for the advantages of more suitable model compound choices and convenient mobile phase pH control. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Markers of anthropogenic contamination: A validated method for quantification of pharmaceuticals, illicit drug metabolites, perfluorinated compounds, and plasticisers in sewage treatment effluent and rain runoff.

Science.gov (United States)

Wilkinson, John L; Swinden, Julian; Hooda, Peter S; Barker, James; Barton, Stephen

2016-09-01

An effective, specific and accurate method is presented for the quantification of 13 markers of anthropogenic contaminants in water using solid phase extraction (SPE) followed by high performance liquid chromatography (HPLC) tandem mass spectrometry (MS/MS). Validation was conducted according to the International Conference on Harmonisation (ICH) guidelines. Method recoveries ranged from 77 to 114% and limits of quantification between 0.75 and 4.91 ng/L. A study was undertaken to quantify the concentrations and loadings of the selected contaminants in 6 sewage treatment works (STW) effluent discharges as well as concentrations in 5 rain-driven street runoffs and field drainages. Detection frequencies in STW effluent ranged from 25% (ethinylestradiol) to 100% (benzoylecgonine, bisphenol-A (BPA), bisphenol-S (BPS) and diclofenac). Average concentrations of detected compounds in STW effluents ranged from 3.62 ng/L (ethinylestradiol) to 210 ng/L (BPA). Levels of perfluorinated compounds (PFCs) perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA) as well as the plasticiser BPA were found in street runoff at maximum levels of 1160 ng/L, 647 ng/L and 2405 ng/L respectively (8.52, 3.09 and 2.7 times more concentrated than maximum levels in STW effluents respectively). Rain-driven street runoff may have an effect on levels of PFCs and plasticisers in receiving rivers and should be further investigated. Together, this method with the 13 selected contaminants enables the quantification of various markers of anthropogenic pollutants: inter alia pharmaceuticals, illicit drugs and their metabolites from humans and improper disposal of drugs, while the plasticisers and perfluorinated compounds may also indicate contamination from industrial and transport activity (street runoff). Copyright © 2016 Elsevier Ltd. All rights reserved.

HPLC-QTOF-MS method for quantitative determination of active compounds in an anti-cellulite herbal compress

Directory of Open Access Journals (Sweden)

Ngamrayu Ngamdokmai

2017-08-01

Full Text Available A herbal compress used in Thai massage has been modified for use in cellulite treatment. Its main active ingredients were ginger, black pepper, java long pepper, tea and coffee. The objective of this study was to develop and validate an HPLCQTOF-MS method for determining its active compounds, i.e., caffeine, 6-gingerol, and piperine in raw materials as well as in the formulation together with the flavouring agent, camphor. The four compounds were chromatographically separated. The analytical method was validated through selectivity, intra-, inter day precision, accuracy and matrix effect. The results showed that the herbal compress contained caffeine (2.16 mg/g, camphor (106.15 mg/g, 6-gingerol (0.76 mg/g, and piperine (4.19 mg/g. The chemical stability study revealed that herbal compresses retained >80% of their active compounds after 1 month of storage at ambient conditions. Our method can be used for quality control of the herbal compress and its raw materials.

Compound nucleus effects in spin-spin cross sections

International Nuclear Information System (INIS)

Thompson, W.J.

1976-01-01

By comparison with recent data, it is shown that spin-spin cross sections for low-energy neutrons may be dominated by a simple compound-elastic level-density effect, independent of spin-spin terms in the nucleon-nucleus optical-model potential. (Auth.)

Content validity and its estimation

Directory of Open Access Journals (Sweden)

Yaghmale F

2003-04-01

Full Text Available Background: Measuring content validity of instruments are important. This type of validity can help to ensure construct validity and give confidence to the readers and researchers about instruments. content validity refers to the degree that the instrument covers the content that it is supposed to measure. For content validity two judgments are necessary: the measurable extent of each item for defining the traits and the set of items that represents all aspects of the traits. Purpose: To develop a content valid scale for assessing experience with computer usage. Methods: First a review of 2 volumes of International Journal of Nursing Studies, was conducted with onlyI article out of 13 which documented content validity did so by a 4-point content validity index (CV! and the judgment of 3 experts. Then a scale with 38 items was developed. The experts were asked to rate each item based on relevance, clarity, simplicity and ambiguity on the four-point scale. Content Validity Index (CVI for each item was determined. Result: Of 38 items, those with CVIover 0.75 remained and the rest were discarded reSulting to 25-item scale. Conclusion: Although documenting content validity of an instrument may seem expensive in terms of time and human resources, its importance warrants greater attention when a valid assessment instrument is to be developed. Keywords: Content Validity, Measuring Content Validity

Development of multicomponent parts-per-billion-level gas standards of volatile toxic organic compounds

International Nuclear Information System (INIS)

Rhoderick, G.C.; Zielinski, W.L. Jr.

1990-01-01

This paper reports that the demand for stable, low-concentration multicomponent standards of volatile toxic organic compounds for quantifying national and state measurement of ambient air quality and hazardous waste incineration emissions has markedly increased in recent years. In response to this demand, a microgravimetric technique was developed and validated for preparing such standards; these standards ranged in concentration from several parts per million (ppm) down to one part per billion (ppb) and in complexity from one organic up to 17. Studies using the gravimetric procedure to prepare mixtures of different groups of organics. including multi-components mixtures in the 5 to 20 ppb range, revealed a very low imprecision. This procedure is based on the separate gravimetric introduction of individual organics into an evacuated gas cylinder, followed by the pressurized addition of a precalculated amount of pure nitrogen. Additional studies confirmed the long-term stability of these mixtures. The uncertainty of the concentrations of the individual organics at the 95% confidence level ranged from less than 1% relative at 1 ppm to less than 10% relative at 1 ppb. Over 100 primary gravimetric standards have been developed, validated, and used for certifying the concentrations of a variety of mixtures for monitoring studies

Simultaneous quantitative analysis of nine vitamin D compounds in human blood using LC-MS/MS.

Science.gov (United States)

Abu Kassim, Nur Sofiah; Gomes, Fabio P; Shaw, Paul Nicholas; Hewavitharana, Amitha K

2016-01-01

It has been suggested that each member of the family of vitamin D compounds may have different function(s). Therefore, selective quantification of each compound is important in clinical research. Development and validation attempts of a simultaneous determination method of 12 vitamin D compounds in human blood using precolumn derivatization followed by LC-MS/MS is described. Internal standard calibration with 12 stable isotope labeled analogs was used to correct for matrix effects in MS detector. Nine vitamin D compounds were quantifiable in blood samples with detection limits within femtomole levels. Serum (compared with plasma) was found to be a more suitable sample type, and protein precipitation (compared with saponification) a more effective extraction method for vitamin D assay.

In silico analysis and experimental validation of azelastine hydrochloride (N4) targeting sodium taurocholate co-transporting polypeptide (NTCP) in HBV therapy.

Science.gov (United States)

Fu, L-L; Liu, J; Chen, Y; Wang, F-T; Wen, X; Liu, H-Q; Wang, M-Y; Ouyang, L; Huang, J; Bao, J-K; Wei, Y-Q

2014-08-01

The aim of this study was to explore sodium taurocholate co-transporting polypeptide (NTCP) exerting its function with hepatitis B virus (HBV) and its targeted candidate compounds, in HBV therapy. Identification of NTCP as a novel HBV target for screening candidate small molecules, was used by phylogenetic analysis, network construction, molecular modelling, molecular docking and molecular dynamics (MD) simulation. In vitro virological examination, q-PCR, western blotting and cytotoxicity studies were used for validating efficacy of the candidate compound. We used the phylogenetic analysis of NTCP and constructed its protein-protein network. Also, we screened compounds from Drugbank and ZINC, among which five were validated for their authentication in HepG 2.2.15 cells. Then, we selected compound N4 (azelastine hydrochloride) as the most potent of them. This showed good inhibitory activity against HBsAg (IC50 = 7.5 μm) and HBeAg (IC50 = 3.7 μm), as well as high SI value (SI = 4.68). Further MD simulation results supported good interaction between compound N4 and NTCP. In silico analysis and experimental validation together demonstrated that compound N4 can target NTCP in HepG2.2.15 cells, which may shed light on exploring it as a potential anti-HBV drug. © 2014 John Wiley & Sons Ltd.

Long-Term Survival Prediction for Coronary Artery Bypass Grafting: Validation of the ASCERT Model Compared With The Society of Thoracic Surgeons Predicted Risk of Mortality.

Science.gov (United States)

Lancaster, Timothy S; Schill, Matthew R; Greenberg, Jason W; Ruaengsri, Chawannuch; Schuessler, Richard B; Lawton, Jennifer S; Maniar, Hersh S; Pasque, Michael K; Moon, Marc R; Damiano, Ralph J; Melby, Spencer J

2018-05-01

The recently developed American College of Cardiology Foundation-Society of Thoracic Surgeons (STS) Collaboration on the Comparative Effectiveness of Revascularization Strategy (ASCERT) Long-Term Survival Probability Calculator is a valuable addition to existing short-term risk-prediction tools for cardiac surgical procedures but has yet to be externally validated. Institutional data of 654 patients aged 65 years or older undergoing isolated coronary artery bypass grafting between 2005 and 2010 were reviewed. Predicted survival probabilities were calculated using the ASCERT model. Survival data were collected using the Social Security Death Index and institutional medical records. Model calibration and discrimination were assessed for the overall sample and for risk-stratified subgroups based on (1) ASCERT 7-year survival probability and (2) the predicted risk of mortality (PROM) from the STS Short-Term Risk Calculator. Logistic regression analysis was performed to evaluate additional perioperative variables contributing to death. Overall survival was 92.1% (569 of 597) at 1 year and 50.5% (164 of 325) at 7 years. Calibration assessment found no significant differences between predicted and actual survival curves for the overall sample or for the risk-stratified subgroups, whether stratified by predicted 7-year survival or by PROM. Discriminative performance was comparable between the ASCERT and PROM models for 7-year survival prediction (p validated for prediction of long-term survival after coronary artery bypass grafting in all risk groups. The widely used STS PROM performed comparably as a predictor of long-term survival. Both tools provide important information for preoperative decision making and patient counseling about potential outcomes after coronary artery bypass grafting. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Validation of GC-IRMS techniques for δ13C and δ2H CSIA of organophosphorus compounds and their potential for studying the mode of hydrolysis in the environment.

Science.gov (United States)

Wu, Langping; Kümmel, Steffen; Richnow, Hans H

2017-04-01

Compound-specific stable isotope analysis (CSIA) is among the most promising tools for studying the fate of organic pollutants in the environment. However, the feasibility of multidimensional CSIA was limited by the availability of a robust method for precise isotope analysis of heteroatom-bearing organic compounds. We developed a method for δ 13 C and δ 2 H analysis of eight organophosphorus compounds (OPs) with different chemical properties. In particular, we aimed to compare high-temperature conversion (HTC) and chromium-based HTC (Cr/HTC) units to explore the limitations of hydrogen isotope analysis of heteroatom-bearing compounds. Analysis of the amount dependency of the isotope values (linearity analysis) of OPs indicated that the formation of HCl was a significant isotope fractionation process leading to inaccurate δ 2 H analysis in HTC. In the case of nonchlorinated OPs, by-product formation of HCN, H 2 S, or PH 3 in HTC was observed but did not affect the dynamic range of reproducible isotope values above the limit of detection. No hydrogen-containing by-products were found in the Cr/HTC process by use of ion trap mass spectrometry analysis. The accuracy of gas chromatography - isotope ratio mass spectrometry was validated in comparison with elemental analyzer - isotope ratio mass spectrometry. Dual-isotope fractionation yielded Λ values of 0 ± 0 at pH 7, 7 ± 1 at pH 9, and 30 ± 6 at pH 12, indicating the potential of 2D CSIA to characterize the hydrolysis mechanisms of OPs. This is the first report on the combination of δ 2 H and δ 13 C isotope analysis of OPs, and this is the first study providing a systematic evaluation of HTC and Cr/HTC for hydrogen isotope analysis using OPs as target compounds. Graphical Abstract Comparison of δ 2 H measurement of non-chlorinated and chlorinated OPs via GC-Cr/HTC-IRMS and GC-HTC-IRMS system.

Development and validation of a luminescence-based, medium-throughput assay for drug screening in Schistosoma mansoni.

Directory of Open Access Journals (Sweden)

Cristiana Lalli

2015-01-01

Full Text Available Schistosomiasis, one of the world's greatest neglected tropical diseases, is responsible for over 280,000 human deaths per annum. Praziquantel, developed in the 1970s, has high efficacy, excellent tolerability, few and transient side effects, simple administration procedures and competitive cost and it is currently the only recommended drug for treatment of human schistosomiasis. The use of a single drug to treat a population of over 200 million infected people appears particularly alarming when considering the threat of drug resistance. Quantitative, objective and validated methods for the screening of compound collections are needed for the discovery of novel anti-schistosomal drugs.The present work describes the development and validation of a luminescence-based, medium-throughput assay for the detection of schistosomula viability through quantitation of ATP, a good indicator of metabolically active cells in culture. This validated method is demonstrated to be fast, highly reliable, sensitive and automation-friendly. The optimized assay was used for the screening of a small compound library on S. mansoni schistosomula, showing that the proposed method is suitable for a medium-throughput semi-automated screening. Interestingly, the pilot screening identified hits previously reported to have some anti-parasitic activity, further supporting the validity of this assay for anthelminthic drug discovery.The developed and validated schistosomula viability luminescence-based assay was shown to be successful and suitable for the identification of novel compounds potentially exploitable in future schistosomiasis therapies.

Leaf Volatile Compounds and Associated Gene Expression during Short-Term Nitrogen Deficient Treatments in Cucumis Seedlings

Directory of Open Access Journals (Sweden)

Jie Deng

2016-11-01

Full Text Available Nitrogen (N is an important macronutrient for plant growth and development, but the regulatory mechanism of volatile compounds in response to N deficiency is not well understood, especially in cucumber, which consumes excessive N during growth. In this study, the major volatile compounds from cucumber leaves subjected to N deficiency were analyzed by GC-MS. A total of 24 volatile components were identified including 15 aldehydes, two ketones, two alkenes, and five other volatile compounds in 9930 leaves. Principal component analysis using volatile compounds from cucumber leaves provided good separation between N-sufficient and N-deficient treatments. The main volatiles in cucumber leaves were found to be C6 and C9 aldehydes, especially (E-2-hexanal and (E,Z-2,6-nonadienal. (E-2-hexanal belonged to the C6 aldehyde and was the most abundant compound, whereas (E,Z-2,6-nonadienal was the chief component of C9 aldehydes. During N-deficient treatment, short-chain volatile content was significantly improved at 5 day, other volatiles displayed significant reduction or no significantly changes in all sampling points. Improvement of short-chain volatiles was confirmed in the six other inbred lines at 5 day after N-deficient treatments. The expression analysis of 12 cucumber LOX genes and two HPL genes revealed that CsLOX19, CsLOX20, and CsLOX22 had common up-regulated expression patterns in response to N-deficient stress in most inbred lines; meanwhile, most sample points of CsHPL1 also had significant up-regulated expression patterns. This research focused on the relationship between volatiles in cucumber and different nitrogen environments to provide valuable insight into the effect of cultivation and management of the quality of cucumber and contributes to further research on volatile metabolism in cucumber.

Quality of longer term mental health facilities in Europe: validation of the quality indicator for rehabilitative care against service users' views.

Science.gov (United States)

Killaspy, Helen; White, Sarah; Wright, Christine; Taylor, Tatiana L; Turton, Penny; Kallert, Thomas; Schuster, Mirjam; Cervilla, Jorge A; Brangier, Paulette; Raboch, Jiri; Kalisova, Lucie; Onchev, Georgi; Alexiev, Spiridon; Mezzina, Roberto; Ridente, Pina; Wiersma, Durk; Visser, Ellen; Kiejna, Andrzej; Piotrowski, Patryk; Ploumpidis, Dimitris; Gonidakis, Fragiskos; Caldas-de-Almeida, José Miguel; Cardoso, Graça; King, Michael

2012-01-01

The Quality Indicator for Rehabilitative Care (QuIRC) is a staff rated, international toolkit that assesses care in longer term hospital and community based mental health facilities. The QuIRC was developed from review of the international literature, an international Delphi exercise with over 400 service users, practitioners, carers and advocates from ten European countries at different stages of deinstitutionalisation, and review of the care standards in these countries. It can be completed in under an hour by the facility manager and has robust content validity, acceptability and inter-rater reliability. In this study, we investigated the internal validity of the QuIRC. Our aim was to identify the QuIRC domains of care that independently predicted better service user experiences of care. At least 20 units providing longer term care for adults with severe mental illness were recruited in each of ten European countries. Service users completed standardised measures of their experiences of care, quality of life, autonomy and the unit's therapeutic milieu. Unit managers completed the QuIRC. Multilevel modelling allowed analysis of associations between service user ratings as dependent variables with unit QuIRC domain ratings as independent variables. 1750/2495 (70%) users and the managers of 213 units from across ten European countries participated. QuIRC ratings were positively associated with service users' autonomy and experiences of care. Associations between QuIRC ratings and service users' ratings of their quality of life and the unit's therapeutic milieu were explained by service user characteristics (age, diagnosis and functioning). A hypothetical 10% increase in QuIRC rating resulted in a clinically meaningful improvement in autonomy. Ratings of the quality of longer term mental health facilities made by service managers were positively associated with service users' autonomy and experiences of care. Interventions that improve quality of care in these

Synthesis, pharmacological activity evaluation and molecular modeling of new polynuclear heterocyclic compounds containing benzimidazole derivatives.

Science.gov (United States)

Bassyouni, Fatma A; Saleh, Tamer S; ElHefnawi, Mahmoud M; Abd El-Moez, Sherein I; El-Senousy, Waled M; Abdel-Rehim, Mohamed E

2012-12-01

Novel heterocyclic compounds containing benzimidazole derivatives were synthesized from 2-(1H-benzimidazol-2-yl) acetonitrile (1) and arylhydrazononitrile derivative 2 was obtained via coupling of 1 with 4-methyl phenyldiazonium salt, which was then reacted with hydroxylamine hydrochloride to give amidooxime derivative 3. This product was cyclized into the corresponding oxadiazole derivative 4 upon reflux in acetic anhydride. Compound 4 was refluxed in DMF in the presence of triethylamine to give the corresponding 5-(1H-benzimidazol-2-yl)-2-p-tolyl-2H-1,2,3-triazol-4-amine 6. Treatment of compound 6 with ethyl chloroformate afforded 2,6-dihydro-2-(4-methylphenyl)-1,2,3-triazolo[4",5"-4',5']pyrimido[1,6-a]benzimidazole-5(4H)-one (8). 1,2-bis(2-cyanomethyl-1H-benzimidazol-1-yl)ethane-1,2-dione (10) was synthesized via the condensation reaction of 2-(1H-benzimidazol-2-yl) acetonitrile (1) and diethyloxalate. The reactivity of compound 10 towards some diamine reagents was studied. The in vitro antimicrobial activity of the synthesized compounds was investigated against several pathogenic bacterial strains such as Escherichia coli O157, Salmonella typhimurium, E. coli O119, S. paratyphi, Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes and Bacillus cereus. The results of MIC revealed that compounds 12a-c showed the most effective antimicrobial activity against tested strains. On the other hand, compounds 12a, b exhibited high activity against rotavirus Wa strain while compounds 12b, c exhibited high activity against adenovirus type 7. In silico target prediction, docking and validation of the compounds 12a-c were performed. The dialkylglycine decarboxylase bacterial enzyme was predicted as a potential bacterial target receptor using pharmacophore-based correspondence with previous leads; giving the highest normalized scores and a high correlation docking score with mean inhibition concentrations. A novel binding mechanism was predicted after docking

Relation of forms of compounds of heavy natural radionuclides in soils

International Nuclear Information System (INIS)

Arkhipov, N.P.; Fedorova, T.A.; Fevraleva, L.T.

1986-01-01

Results of studying forms of 238 U, 232 Th, 226 Ra, 210 Po, 210 Pb compounds in nonfertilized soils (under control) and in soils fertilized with ammophos containing increased amount of the mentioned radionuclides are given. The study was performed in main-year field experiment with sandy ashen gray soil and leached chernozemic soil. It is shown that a main share of radionuclides in nonfertilized soils is presened with tightly bound compounds and compounds bound with sesquioxide compounds. After 5 years labelled natural radionuclides introduced into the ammophos composition are in a more mobile state as compared with radionuclides in nonfertilized soil and they are presented with acid-soluble and bound with humus compound forms. Systematical application of fertilizers during along-term period results in the concentration increase of heavy natural radionuclides in soil

Validation of the Hwalek-Sengstock Elder Abuse Screening Test.

Science.gov (United States)

Neale, Anne Victoria; And Others

Elder abuse is recognized as an under-detected and under-reported social problem. Difficulties in detecting elder abuse are compounded by the lack of a standardized, psychometrically valid instrument for case finding. The development of the Hwalek-Sengstock Elder Abuse Screening Test (H-S/EAST) followed a larger effort to identify indicators and…

Validation of EAF-2005 data

International Nuclear Information System (INIS)

Kopecky, J.

2005-01-01

Full text: Validation procedures applied on EAF-2003 starter file, which lead to the production of EAF-2005 library, are described. The results in terms of reactions with assigned quality scores in EAF-20005 are given. Further the extensive validation against the recent integral data is discussed together with the status of the final report 'Validation of EASY-2005 using integral measurements'. Finally, the novel 'cross section trend analysis' is presented with some examples of its use. This action will lead to the release of improved library EAF-2005.1 at the end of 2005, which shall be used as the starter file for EAF-2007. (author)

Vibrio anguillarum Is Genetically and Phenotypically Unaffected by Long-Term Continuous Exposure to the Antibacterial Compound Tropodithietic Acid

DEFF Research Database (Denmark)

Rasmussen, Bastian Barker; Grotkjær, Torben; D'Alvise, Paul

2016-01-01

unaffected, supporting the application of TDA-producing roseobacters as probiotics in aquaculture. It is important to limit the use of antibiotics in our food production, to reduce the risk of bacteria developing antibiotic resistance. We showed previously that marine bacteria of the Roseobacter clade can......Minimizing the use of antibiotics in the food production chain is essential for limiting the development and spread of antibiotic-resistant bacteria. One alternative intervention strategy is the use of probiotic bacteria, and bacteria of the marine Roseobacter clade are capable of antagonizing fish...... potential side effects of long-term exposure of the pathogen to the probionts or any compounds they produce. Here we exposed the fish pathogen Vibrio anguillarum to TDA for several hundred generations in an adaptive evolution experiment. No tolerance or resistance arose during the 90 days of exposure...

Impurities in biogas - validation of analytical methods for siloxanes; Foeroreningar i biogas - validering av analysmetodik foer siloxaner

Energy Technology Data Exchange (ETDEWEB)

Arrhenius, Karine; Magnusson, Bertil; Sahlin, Eskil [SP Technical Research Institute of Sweden, Boraas (Sweden)

2011-11-15

Biogas produced from digester or landfill contains impurities which can be harmful for component that will be in contact with the biogas during its utilization. Among these, the siloxanes are often mentioned. During combustion, siloxanes are converted to silicon dioxide which accumulates on the heated surfaces in combustion equipment. Silicon dioxide is a solid compound and will remain in the engine and cause damages. Consequently, it is necessary to develop methods for the accurate determination of these compounds in biogases. In the first part of this report, a method for analysis of siloxanes in biogases was validated. The sampling was performed directly at the plant by drawing a small volume of biogas onto an adsorbent tube under a short period of time. These tubes were subsequently sent to the laboratory for analysis. The purpose of method validation is to demonstrate that the established method is fit for the purpose. This means that the method, as used by the laboratory generating the data, will provide data that meets a set of criteria concerning precision and accuracy. At the end, the uncertainty of the method was calculated. In the second part of this report, the validated method was applied to real samples collected in waste water treatment plants, co-digestion plants and plants digesting other wastes (agriculture waste). Results are presented at the end of this report. As expected, the biogases from waste water treatment plants contained largely higher concentrations of siloxanes than biogases from co-digestion plants and plants digesting agriculture wastes. The concentration of siloxanes in upgraded biogas regardless of which feedstock was digested and which upgrading technique was used was low.

Identifying natural compounds as multi-target-directed ligands against Alzheimer's disease: an in silico approach.

Science.gov (United States)

Ambure, Pravin; Bhat, Jyotsna; Puzyn, Tomasz; Roy, Kunal

2018-04-23

Alzheimer's disease (AD) is a multi-factorial disease, which can be simply outlined as an irreversible and progressive neurodegenerative disorder with an unclear root cause. It is a major cause of dementia in old aged people. In the present study, utilizing the structural and biological activity information of ligands for five important and mostly studied vital targets (i.e. cyclin-dependant kinase 5, β-secretase, monoamine oxidase B, glycogen synthase kinase 3β, acetylcholinesterase) that are believed to be effective against AD, we have developed five classification models using linear discriminant analysis (LDA) technique. Considering the importance of data curation, we have given more attention towards the chemical and biological data curation, which is a difficult task especially in case of big data-sets. Thus, to ease the curation process we have designed Konstanz Information Miner (KNIME) workflows, which are made available at http://teqip.jdvu.ac.in/QSAR_Tools/ . The developed models were appropriately validated based on the predictions for experiment derived data from test sets, as well as true external set compounds including known multi-target compounds. The domain of applicability for each classification model was checked based on a confidence estimation approach. Further, these validated models were employed for screening of natural compounds collected from the InterBioScreen natural database ( https://www.ibscreen.com/natural-compounds ). Further, the natural compounds that were categorized as 'actives' in at least two classification models out of five developed models were considered as multi-target leads, and these compounds were further screened using the drug-like filter, molecular docking technique and then thoroughly analyzed using molecular dynamics studies. Finally, the most potential multi-target natural compounds against AD are suggested.

Validation of LC–TOF-MS Screening for Drugs, Metabolites, and Collateral Compounds in Forensic Toxicology Specimens

Science.gov (United States)

Guale, Fessessework; Shahreza, Shahriar; Walterscheid, Jeffrey P.; Chen, Hsin-Hung; Arndt, Crystal; Kelly, Anna T.; Mozayani, Ashraf

2013-01-01

Liquid chromatography time-of-flight mass spectrometry (LC–TOF-MS) analysis provides an expansive technique for identifying many known and unknown analytes. This study developed a screening method that utilizes automated solid-phase extraction to purify a wide array of analytes involving stimulants, benzodiazepines, opiates, muscle relaxants, hypnotics, antihistamines, antidepressants and newer synthetic “Spice/K2” cannabinoids and cathinone “bath salt” designer drugs. The extract was applied to LC–TOF-MS analysis, implementing a 13 min chromatography gradient with mobile phases of ammonium formate and methanol using positive mode electrospray. Several common drugs and metabolites can share the same mass and chemical formula among unrelated compounds, but they are structurally different. In this method, the LC–TOF-MS was able to resolve many isobaric compounds by accurate mass correlation within 15 ppm mass units and a narrow retention time interval of less than 10 s of separation. Drug recovery yields varied among spiked compounds, but resulted in overall robust area counts to deliver an average match score of 86 when compared to the retention time and mass of authentic standards. In summary, this method represents a rapid, enhanced screen for blood and urine specimens in postmortem, driving under the influence, and drug facilitated sexual assault forensic toxicology casework. PMID:23118149

Validation of LC-TOF-MS screening for drugs, metabolites, and collateral compounds in forensic toxicology specimens.

Science.gov (United States)

Guale, Fessessework; Shahreza, Shahriar; Walterscheid, Jeffrey P; Chen, Hsin-Hung; Arndt, Crystal; Kelly, Anna T; Mozayani, Ashraf

2013-01-01

Liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) analysis provides an expansive technique for identifying many known and unknown analytes. This study developed a screening method that utilizes automated solid-phase extraction to purify a wide array of analytes involving stimulants, benzodiazepines, opiates, muscle relaxants, hypnotics, antihistamines, antidepressants and newer synthetic "Spice/K2" cannabinoids and cathinone "bath salt" designer drugs. The extract was applied to LC-TOF-MS analysis, implementing a 13 min chromatography gradient with mobile phases of ammonium formate and methanol using positive mode electrospray. Several common drugs and metabolites can share the same mass and chemical formula among unrelated compounds, but they are structurally different. In this method, the LC-TOF-MS was able to resolve many isobaric compounds by accurate mass correlation within 15 ppm mass units and a narrow retention time interval of less than 10 s of separation. Drug recovery yields varied among spiked compounds, but resulted in overall robust area counts to deliver an average match score of 86 when compared to the retention time and mass of authentic standards. In summary, this method represents a rapid, enhanced screen for blood and urine specimens in postmortem, driving under the influence, and drug facilitated sexual assault forensic toxicology casework.

Synthesis and structural characterization of actinide oxalate compounds

International Nuclear Information System (INIS)

Tamain, C.

2011-01-01

Oxalic acid is a well-known reagent to recover actinides thanks to the very low solubility of An(IV) and An(III) oxalate compounds in acidic solution. Therefore, considering mixed-oxide fuel or considering minor actinides incorporation in ceramic fuel materials for transmutation, oxalic co-conversion is convenient to synthesize mixed oxalate compounds, precursors of oxide solid solutions. As the existing oxalate single crystal syntheses are not adaptable to the actinide-oxalate chemistry or to their manipulation constrains in gloves box, several original crystal growth methods were developed. They were first validate and optimized on lanthanides and uranium before the application to transuranium elements. The advanced investigations allow to better understand the syntheses and to define optimized chemical conditions to promote crystal growth. These new crystal growth methods were then applied to a large number of mixed An1(IV)-An2(III) or An1(IV)-An2(IV) systems and lead to the formation of the first original mixed An1(IV)-An2(III) and An1(IV)-An2(IV) oxalate single crystals. Finally thanks to the first thorough structural characterizations of these compounds, single crystal X-ray diffraction, EXAFS or micro-RAMAN, the particularly weak oxalate-actinide compounds structural database is enriched, which is essential for future studied nuclear fuel cycles. (author) [fr

Steroidal Compounds in Commercial Parenteral Lipid Emulsions

Science.gov (United States)

Xu, Zhidong; Harvey, Kevin A.; Pavlina, Thomas; Dutot, Guy; Hise, Mary; Zaloga, Gary P.; Siddiqui, Rafat A.

2012-01-01

Parenteral nutrition lipid emulsions made from various plant oils contain steroidal compounds, called phytosterols. During parenteral administration of lipid emulsions, phytosterols can reach levels in the blood that are many fold higher than during enteral administration. The elevated phytosterol levels have been associated with the development of liver dysfunction and the rare development of liver failure. There is limited information available in the literature related to phytosterol concentrations in lipid emulsions. The objective of the current study was to validate an assay for steroidal compounds found in lipid emulsions and to compare their concentrations in the most commonly used parenteral nutrition lipid emulsions: Liposyn® II, Liposyn® III, Lipofundin® MCT, Lipofundin® N, Structolipid®, Intralipid®, Ivelip® and ClinOleic®. Our data demonstrates that concentrations of the various steroidal compounds varied greatly between the eight lipid emulsions, with the olive oil-based lipid emulsion containing the lowest levels of phytosterols and cholesterol, and the highest concentration of squalene. The clinical impression of greater incidences of liver dysfunction with soybean versus MCT/LCT and olive/soy lipid emulsions may be reflective of the levels of phytosterols in these emulsions. This information may help guide future studies and clinical care of patients with lipid emulsion-associated liver dysfunction. PMID:23016123

Steroidal compounds in commercial parenteral lipid emulsions.

Science.gov (United States)

Xu, Zhidong; Harvey, Kevin A; Pavlina, Thomas; Dutot, Guy; Hise, Mary; Zaloga, Gary P; Siddiqui, Rafat A

2012-08-01

Parenteral nutrition lipid emulsions made from various plant oils contain steroidal compounds, called phytosterols. During parenteral administration of lipid emulsions, phytosterols can reach levels in the blood that are many fold higher than during enteral administration. The elevated phytosterol levels have been associated with the development of liver dysfunction and the rare development of liver failure. There is limited information available in the literature related to phytosterol concentrations in lipid emulsions. The objective of the current study was to validate an assay for steroidal compounds found in lipid emulsions and to compare their concentrations in the most commonly used parenteral nutrition lipid emulsions: Liposyn(®) II, Liposyn(®) III, Lipofundin(®) MCT, Lipofundin(®) N, Structolipid(®), Intralipid(®), Ivelip(®) and ClinOleic(®). Our data demonstrates that concentrations of the various steroidal compounds varied greatly between the eight lipid emulsions, with the olive oil-based lipid emulsion containing the lowest levels of phytosterols and cholesterol, and the highest concentration of squalene. The clinical impression of greater incidences of liver dysfunction with soybean versus MCT/LCT and olive/soy lipid emulsions may be reflective of the levels of phytosterols in these emulsions. This information may help guide future studies and clinical care of patients with lipid emulsion-associated liver dysfunction.

Development of an Intracellular Screen for New Compounds Able To Inhibit Mycobacterium tuberculosis Growth in Human Macrophages.

Science.gov (United States)

Sorrentino, Flavia; Gonzalez del Rio, Ruben; Zheng, Xingji; Presa Matilla, Jesus; Torres Gomez, Pedro; Martinez Hoyos, Maria; Perez Herran, Maria Esther; Mendoza Losana, Alfonso; Av-Gay, Yossef

2016-01-01

Here we describe the development and validation of an intracellular high-throughput screening assay for finding new antituberculosis compounds active in human macrophages. The assay consists of a luciferase-based primary identification assay, followed by a green fluorescent protein-based secondary profiling assay. Standard tuberculosis drugs and 158 previously recognized active antimycobacterial compounds were used to evaluate assay robustness. Data show that the assay developed is a short and valuable tool for the discovery of new antimycobacterial compounds. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Bioactive compounds from orange epicarp to enrich fish burgers.

Science.gov (United States)

Spinelli, Sara; Lecce, Lucia; Likyova, Desislava; Del Nobile, Matteo Alessandro; Conte, Amalia

2018-05-01

The orange industry produces considerable amounts of by-products, traditionally used for animal feed or fuel production. Most of these by-products could be used as functional ingredients. To assess the potential food application of orange epicarp, different percentages of micro-encapsulated orange extract were added to fresh fish burgers. Then, an in vitro digestion was also carried out, before and after micro-encapsulation, to measure the bio-accessibility of the active compounds. A significant increase of bio-accessibility of bioactive compounds has been observed in the orange epicarp extract after micro-encapsulation by spray-drying. From the sensory point of view, the fish sample enriched with 50 g kg -1 micro-encapsulated extract was the most comparable to the control burger, even if it showed a higher phenolic, flavonoid and carotenoid bio-accessibility. Orange epicarp may be used as a food additive to enhance the health content of food products. The micro-encapsulation is a valid technique to protect the bioactive compounds and increase their bio-accessibility. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Reliability and validity in a nutshell.

Science.gov (United States)

Bannigan, Katrina; Watson, Roger

2009-12-01

To explore and explain the different concepts of reliability and validity as they are related to measurement instruments in social science and health care. There are different concepts contained in the terms reliability and validity and these are often explained poorly and there is often confusion between them. To develop some clarity about reliability and validity a conceptual framework was built based on the existing literature. The concepts of reliability, validity and utility are explored and explained. Reliability contains the concepts of internal consistency and stability and equivalence. Validity contains the concepts of content, face, criterion, concurrent, predictive, construct, convergent (and divergent), factorial and discriminant. In addition, for clinical practice and research, it is essential to establish the utility of a measurement instrument. To use measurement instruments appropriately in clinical practice, the extent to which they are reliable, valid and usable must be established.

Construction and validation of nursing diagnoses for people in palliative care

Directory of Open Access Journals (Sweden)

Rudval Souza da Silva

Full Text Available ABSTRACT Objective: to construct and validate nursing diagnoses for people in palliative care based on the Dignity-Conserving Care Model and the International Classification for Nursing Practice. Method: a two-stage methodological study: 1 construction of the database of clinically and culturally relevant terms for the nursing care for people in palliative care and 2 construction of nursing diagnoses from the database of terms, based on the guidelines of the International Council of Nurses. Results: the 262 terms validated constituted a database of terms from which 56 nursing diagnoses were developed. Of these, 33 were validated by a group of 26 experts, and classified in the three categories of the Dignity-Conserving Care Model: illness-related concerns (21; dignity-conserving repertoire (9; and social dignity inventory (3. Conclusion: of the 33 validated diagnoses, 18 of them could be included in the update of the Catalog of the International Classification for Nursing Practice - palliative care for a dignified death. The study contributes to support the clinical reasoning and decision making of the nurse.

General inattentiveness is a long-term reliable trait independently predictive of psychological health: Danish validation studies of the Mindful Attention Awareness Scale.

Science.gov (United States)

Jensen, Christian Gaden; Niclasen, Janni; Vangkilde, Signe Allerup; Petersen, Anders; Hasselbalch, Steen Gregers

2016-05-01

The Mindful Attention Awareness Scale (MAAS) measures perceived degree of inattentiveness in different contexts and is often used as a reversed indicator of mindfulness. MAAS is hypothesized to reflect a psychological trait or disposition when used outside attentional training contexts, but the long-term test-retest reliability of MAAS scores is virtually untested. It is unknown whether MAAS predicts psychological health after controlling for standardized socioeconomic status classifications. First, MAAS translated to Danish was validated psychometrically within a randomly invited healthy adult community sample (N = 490). Factor analysis confirmed that MAAS scores quantified a unifactorial construct of excellent composite reliability and consistent convergent validity. Structural equation modeling revealed that MAAS scores contributed independently to predicting psychological distress and mental health, after controlling for age, gender, income, socioeconomic occupational class, stressful life events, and social desirability (β = 0.32-.42, ps health. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Development and Characterization of Titanium Compound N anostructures

Science.gov (United States)

Zhou, Zhou

The development and characterization of titanium compound nanostructures have been achieved, for potential applications in energy industry. Oil and gas, one of the traditional industry fields, observes accumulating demands on active implementations of nanotechnology, for the numerous advantages that nanomaterials can introduce to both product performances and field operations. By using chemical vapor deposition and liquid exfoliation, various titanium compound nanostructures have been synthesized through this project. Attractively, these two material fabrication methods have been recognized to be industrial friendly in terms of cost efficiency and productivity. The development of nanostructures, aiming at oil and gas field applications, presents novel solutions for existing issues, such as low durability of drilling tools, high friction in mechanical operations and ineffective heat dissipation. Titanium compound nanostructures, including titanium borides, nitrides and sulfides are therefore investigated for such applications as protective coating, lubrication and thermal management.

Neuroleptics as therapeutic compounds stabilizing neuromuscular transmission in amyotrophic lateral sclerosis.

Science.gov (United States)

Patten, Shunmoogum A; Aggad, Dina; Martinez, Jose; Tremblay, Elsa; Petrillo, Janet; Armstrong, Gary Ab; La Fontaine, Alexandre; Maios, Claudia; Liao, Meijiang; Ciura, Sorana; Wen, Xiao-Yan; Rafuse, Victor; Ichida, Justin; Zinman, Lorne; Julien, Jean-Pierre; Kabashi, Edor; Robitaille, Richard; Korngut, Lawrence; Parker, J Alexander; Drapeau, Pierre

2017-11-16

Amyotrophic lateral sclerosis (ALS) is a rapidly progressing, fatal disorder with no effective treatment. We used simple genetic models of ALS to screen phenotypically for potential therapeutic compounds. We screened libraries of compounds in C. elegans, validated hits in zebrafish, and tested the most potent molecule in mice and in a small clinical trial. We identified a class of neuroleptics that restored motility in C. elegans and in zebrafish, and the most potent was pimozide, which blocked T-type Ca2+ channels in these simple models and stabilized neuromuscular transmission in zebrafish and enhanced it in mice. Finally, a short randomized controlled trial of sporadic ALS subjects demonstrated stabilization of motility and evidence of target engagement at the neuromuscular junction. Simple genetic models are, thus, useful in identifying promising compounds for the treatment of ALS, such as neuroleptics, which may stabilize neuromuscular transmission and prolong survival in this disease.

Quantitative prediction of solvation free energy in octanol of organic compounds.

Science.gov (United States)

Delgado, Eduardo J; Jaña, Gonzalo A

2009-03-01

The free energy of solvation, DeltaGS0, in octanol of organic compounds is quantitatively predicted from the molecular structure. The model, involving only three molecular descriptors, is obtained by multiple linear regression analysis from a data set of 147 compounds containing diverse organic functions, namely, halogenated and non-halogenated alkanes, alkenes, alkynes, aromatics, alcohols, aldehydes, ketones, amines, ethers and esters; covering a DeltaGS0 range from about -50 to 0 kJ.mol(-1). The model predicts the free energy of solvation with a squared correlation coefficient of 0.93 and a standard deviation, 2.4 kJ.mol(-1), just marginally larger than the generally accepted value of experimental uncertainty. The involved molecular descriptors have definite physical meaning corresponding to the different intermolecular interactions occurring in the bulk liquid phase. The model is validated with an external set of 36 compounds not included in the training set.

Qualitative screening of undesirable compounds from feeds to fish by liquid chromatography coupled to mass spectrometry.

Science.gov (United States)

Nácher-Mestre, Jaime; Ibáñez, María; Serrano, Roque; Pérez-Sánchez, Jaume; Hernández, Félix

2013-03-06

This paper describes the development, validation, and application of a rapid screening method for the detection and identification of undesirable organic compounds in aquaculture products. A generic sample treatment was applied without any purification or preconcentration step. After extraction of the samples with acetonitrile/water 80:20 (0.1% formic acid), the extracts were centrifuged and directly injected in the LC-HRMS system, consisting of ultra-high performance liquid chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS). A qualitative validation was carried out for over 70 representative compounds, including antibiotics, pesticides, and mycotoxins, in fish feed and fish fillets spiked at 20 and 100 μg/kg. At the highest level, the great majority of compounds were detected (using the most abundant ion, typically the protonated molecule) and unequivocally identified (on the basis of the presence of two accurate-mass measured ions). At the 20 μg/kg level, many contaminants could already be detected, although identification using two ions was not fully reached for some of them, mainly in fish feed due to the complexity of this matrix. Subsequent application of this screening methodology to aquaculture samples made it possible to find several compounds from the target list, such as the antibiotic ciprofloxacin, the insecticide pirimiphos-methyl, and the mycotoxins fumonisin B2 and zearalenone. A retrospective analysis of accurate-mass full-spectrum acquisition data provided by QTOF MS was also made, without either reprocessing or injecting the samples. This allowed the detection and tentative identification of other organic undesirables different from those included in the validated list.

HPLC method validated for the simultaneous analysis of cichoric acid and alkamides in Echinacea purpurea plants and products

DEFF Research Database (Denmark)

Mølgaard, Per; Johnsen, Søren; Christensen, Peter

2003-01-01

phenolics as well as the lipophilic alkamides are released from the samples, followed by the analytical HPLC procedure for quantitative determination of these compounds. The method is the first one validated for the determination of these two groups of compounds in the same procedure. Naringenin has been...

Drug metabolism and pharmacokinetic diversity of ranunculaceae medicinal compounds.

Science.gov (United States)

Hao, Da-Cheng; Ge, Guang-Bo; Xiao, Pei-Gen; Wang, Ping; Yang, Ling

2015-01-01

The wide-reaching distributed angiosperm family Ranunculaceae has approximately 2200 species in around 60 genera. Chemical components of this family include several representative groups: benzylisoquinoline alkaloid (BIA), ranunculin, triterpenoid saponin and diterpene alkaloid, etc. Their extensive clinical utility has been validated by traditional uses of thousands of years and current evidence-based medicine studies. Drug metabolism and pharmacokinetic (DMPK) studies of plant-based natural products are an indispensable part of comprehensive medicinal plant exploration, which could facilitate conservation and sustainable utilization of Ranunculaceae pharmaceutical resources, as well as new chemical entity development with improved DMPK parameters. However, DMPK characteristics of Ranunculaceaederived medicinal compounds have not been summarized. Black cohosh (Cimicifuga) and goldenseal (Hydrastis) raise concerns of herbdrug interaction. DMPK studies of other Ranunculaceae genera, e.g., Nigella, Delphinium, Aconitum, Trollius, and Coptis, are also rapidly increasing and becoming more and more clinically relevant. In this contribution, we highlight the up-to-date awareness, as well as the challenges around the DMPK-related issues in optimization of drug development and clinical practice of Ranunculaceae compounds. Herb-herb interaction of Ranunculaceae herb-containing traditional Chinese medicine (TCM) formula could significantly influence the in vivo pharmacokinetic behavior of compounds thereof, which may partially explain the complicated therapeutic mechanism of TCM formula. Although progress has been made on revealing the absorption, distribution, metabolism, excretion and toxicity (ADME/T) of Ranunculaceae compounds, there is a lack of DMPK studies of traditional medicinal genera Aquilegia, Thalictrum and Clematis. Fluorescent probe compounds could be promising substrate, inhibitor and/or inducer in future DMPK studies of Ranunculaceae compounds. A better

Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries

Science.gov (United States)

Doherty, J.P.; Marek, J.C.

1987-02-25

A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper(II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the original organic compounds, is subsequently blended with high level radioactive sludge land transferred to a vitrification facility for processing into borosilicate glass for long-term storage. 2 figs., 3 tabs.

The importance of short-term off-target effects in estimating the long-term renal and cardiovascular protection of angiotensin receptor blockers

DEFF Research Database (Denmark)

Smink, P A; Miao, Y; Eijkemans, M J C

2014-01-01

Angiotensin receptor blockers (ARBs) have multiple effects that may contribute to their efficacy on renal/cardiovascular outcomes. We developed and validated a risk score that incorporated short-term changes in multiple risk markers to predict the ARB effect on renal/cardiovascular outcomes.......98), in addition to being markedly more accurate than predicted RRRs based on changes in single markers. The score was validated in an independent ARB trial. Predictions of long-term renal/cardiovascular ARB effects are more accurate when considering short-term changes in multiple risk markers, challenging the use...

PREPARATION AND PROPERTIES OF COMPOUND ARNEBIAE RADIX MICROEMULSION GEL.

Science.gov (United States)

Chen, Jing; He, Yanping; Gao, Ting; Zhang, Licheng; Zhao, Yuna

2017-01-01

Compound Arnebiae radix oil has been clinically applied to treat burns and scalds for a long time. However, it is unstable and inconvenient to use. The aim of this study was to prepare a compound Arnebiae radix microemulsion gel for transdermal delivery system and evaluate its characteristics. Based on the solubility of Shikonin, the active component of Arnebiae radix and the results of phase studies, adequate ratio of each component in microemulsion was determined. The optimized microemulsion gel was prepared using Carbomer 940. The gels were characterized in terms of appearance, preliminary stability test and the content of Shikonin in the compound Arnebiae radix microemulsion gel with HPLC analysis. The optimized conditions for preparing microemulsion were Tween-80, glycerin, isopropyl myristate (IPM) with the ratio of 6:3:2. The optimal microemulsion gel was obtained with Carbomer 940 (1.0%). The prepared compound Arnebiae radix microemulsion gel showed good stability over time. It is more convenience in application than the previous used formulations.

Band structure of Heusler compounds studied by photoemission and tunneling spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Arbelo Jorge, Elena

2011-07-01

Heusler compounds are key materials for spintronic applications. They have attracted a lot of interest due to their half-metallic properties predicted by band structure calculations. The aim of this work is to evaluate experimentally the validity of the predictions of half metallicity by band structure calculations for two specific Heusler compounds, Co{sub 2}FeAl{sub 0.3}Si{sub 0.7} and Co{sub 2}MnGa. Two different spectroscopy methods for the analysis of the electronic properties were used: Angular Resolved Ultraviolet Photoemission Spectroscopy (ARUPS) and Tunneling Spectroscopy. Heusler compounds are prepared as thin films by RF-sputtering in an ultra high vacuum system. For the characterization of the samples, bulk and surface crystallographic and magnetic properties of Co{sub 2}FeAl{sub 0.3}Si{sub 0.7} and Co{sub 2}MnGa are studied. X-ray and electron diffraction reveal a bulk and surface crossover between two different types of sublattice order (from B2 to L2{sub 1}) with increasing annealing temperature. X-ray magnetic circular dichroism results show that the magnetic properties in the surface and bulk are identical, although the magnetic moments obtained are 5 % below from the theoretically predicted. By ARUPS evidence for the validity of the predicted total bulk density of states (DOS) was demonstrated for both Heusler compounds. Additional ARUPS intensity contributions close to the Fermi energy indicates the presence of a specific surface DOS. Moreover, it is demonstrated that the crystallographic order, controlled by annealing, plays an important role on broadening effects of DOS features. Improving order resulted in better defined ARUPS features. Tunneling magnetoresistance measurements of Co{sub 2}FeAl{sub 0.3}Si{sub 0.7} and Co{sub 2}MnGa based MTJ's result in a Co{sub 2}FeAl{sub 0.3}Si{sub 0.7} spin polarization of 44 %, which is the highest experimentally obtained value for this compound, although it is lower than the 100 % predicted. For Co

BitterSweetForest: A random forest based binary classifier to predict bitterness and sweetness of chemical compounds

Science.gov (United States)

Banerjee, Priyanka; Preissner, Robert

2018-04-01

Taste of a chemical compounds present in food stimulates us to take in nutrients and avoid poisons. However, the perception of taste greatly depends on the genetic as well as evolutionary perspectives. The aim of this work was the development and validation of a machine learning model based on molecular fingerprints to discriminate between sweet and bitter taste of molecules. BitterSweetForest is the first open access model based on KNIME workflow that provides platform for prediction of bitter and sweet taste of chemical compounds using molecular fingerprints and Random Forest based classifier. The constructed model yielded an accuracy of 95% and an AUC of 0.98 in cross-validation. In independent test set, BitterSweetForest achieved an accuracy of 96 % and an AUC of 0.98 for bitter and sweet taste prediction. The constructed model was further applied to predict the bitter and sweet taste of natural compounds, approved drugs as well as on an acute toxicity compound data set. BitterSweetForest suggests 70% of the natural product space, as bitter and 10 % of the natural product space as sweet with confidence score of 0.60 and above. 77 % of the approved drug set was predicted as bitter and 2% as sweet with a confidence scores of 0.75 and above. Similarly, 75% of the total compounds from acute oral toxicity class were predicted only as bitter with a minimum confidence score of 0.75, revealing toxic compounds are mostly bitter. Furthermore, we applied a Bayesian based feature analysis method to discriminate the most occurring chemical features between sweet and bitter compounds from the feature space of a circular fingerprint.

Comprehensive Analysis of Umami Compounds by Ion-Pair Liquid Chromatography Coupled to Mass Spectrometry

NARCIS (Netherlands)

Coulier, L.; Bas, R.; Hekman, M.; Werff, B.J.C. van der; Burgering, M.; Thissen, U.

2011-01-01

An ion-pair LC-ESI-MS method was developed capable of analyzing various reported umami or umami-enhancing compounds, including glutamic acid and 5'-ribonucleotides. The method was validated using tomato and potato samples and showed overall good analytical performance with respect to selectivity,

Antioxidant behavior of mearnsetin and myricetin flavonoid compounds — A DFT study

Science.gov (United States)

Sadasivam, K.; Kumaresan, R.

2011-06-01

The molecular characteristics of two naturally occurring flavonoid compounds mearnsetin and myricetin have been computed using density functional theory (DFT) approach with B3LYP/6-311G(d,p) level of theory. The computation and analysis of bond dissociation enthalpy magnitudes for all the OH sites for both the compounds clearly denotes the contribution of the B-ring for the antioxidant activity. The analysis has also indicated the higher values of BDE on the C5-OH radical species in both the compounds. The computed vibrational frequency analysis indicates the absence of imaginary frequency in the neutral as well as radical species of both the flavonoid compounds. The ionisation potential (IP) analysis was found to be within the range of the IP of synthetic food additives. In addition, various molecular descriptors such as electron affinity, hardness, softness, electronegativity, electrophilic index have also been calculated and the validity of Koopman's theorem is verified. The plot of frontier molecular orbital and spin density distribution analysis for neutral and the corresponding radical species for both the compounds have been computed and interpreted. The polar nature and their polarizing capacity are well established through the analysis of dipole moment and polarisability magnitudes.

Angelica sinensis (Oliv.) Diels: Influence of Value Chain on Quality Criteria and Marker Compounds Ferulic Acid and Z-Ligustilide.

Science.gov (United States)

Giacomelli, Nino; Yongping, Yang; Huber, Franz K; Ankli, Anita; Weckerle, Caroline S

2017-03-14

Background: Dang gui (Apiaceae; Angelica sinensis radix) is among the most often used Chinese medicinal plants. However, hardly anything is known about its value chain and its influence on the main marker compounds of the drug. The aim of this study is to investigate the value chain of dang gui in Gansu and Yunnan, and the analysis of the marker compounds ferulic acid and Z-ligustilide concentration in relation to quality criteria such as the production area and size of the roots. Methods: During six months of field research in China, semi-structured interviews with various stakeholders of the value chain were undertaken and plant material was collected. High-performance thin layer chromatography (HPTLC) was used for semi-quantitative analysis of ferulic acid and Z-ligustilide. Results: Small-scale household cultivation prevails and in Gansu-in contrast to Yunnan-the cultivation of dang gui is often the main income source of farmers. Farmers and dealers use size and odor of the root as main quality criteria. For Chinese medicine doctors, Gansu as the production area is the main criterion. Higher amounts of ferulic acid in plant material from Yunnan compared to Gansu were found. Additionally, a negative relation of root length with both ferulic acid and Z-ligustilide as well as head diameter with ferulic acid were found. Conclusions: HPTLC is a valid method for semi-quantitative analysis of the marker compounds of dang gui . However, the two main marker compounds cannot explain why size and smell of the root or production area are seen as quality criteria. This hints at the inherent difficulty to correlate quality notions of medicinal plants with specific chemical compounds. With respect to this, more attention should be paid to quality in terms of cultivation and processing techniques.

Publicly available models to predict normal boiling point of organic compounds

International Nuclear Information System (INIS)

Oprisiu, Ioana; Marcou, Gilles; Horvath, Dragos; Brunel, Damien Bernard; Rivollet, Fabien; Varnek, Alexandre

2013-01-01

Quantitative structure–property models to predict the normal boiling point (T b ) of organic compounds were developed using non-linear ASNNs (associative neural networks) as well as multiple linear regression – ISIDA-MLR and SQS (stochastic QSAR sampler). Models were built on a diverse set of 2098 organic compounds with T b varying in the range of 185–491 K. In ISIDA-MLR and ASNN calculations, fragment descriptors were used, whereas fragment, FPTs (fuzzy pharmacophore triplets), and ChemAxon descriptors were employed in SQS models. Prediction quality of the models has been assessed in 5-fold cross validation. Obtained models were implemented in the on-line ISIDA predictor at (http://infochim.u-strasbg.fr/webserv/VSEngine.html)

Isotopically modified compounds

International Nuclear Information System (INIS)

Kuruc, J.

2009-01-01

In this chapter the nomenclature of isotopically modified compounds in Slovak language is described. This chapter consists of following parts: (1) Isotopically substituted compounds; (2) Specifically isotopically labelled compounds; (3) Selectively isotopically labelled compounds; (4) Non-selectively isotopically labelled compounds; (5) Isotopically deficient compounds.

Heterogeneity between and within Strains of Lactobacillus brevis Exposed to Beer Compounds.

Science.gov (United States)

Zhao, Yu; Knøchel, Susanne; Siegumfeldt, Henrik

2017-01-01

This study attempted to investigate the physiological response of six Lactobacillus brevis strains to hop stress, with and without the addition of Mn 2+ or ethanol. Based on the use of different fluorescent probes, cell viability and intracellular pH (pHi) were assessed by fluorescence microscopy combined with flow cytometry, at the single cell level. The combined approach was faster than the traditional colony based method, but also provided additional information about population heterogeneity with regard to membrane damage and cell size reduction, when exposed to hop compounds. Different physiological subpopulations were detected under hop stress in both hop tolerant and sensitive strains. A large proportion of cells were killed in all the tested strains, but a small subpopulation from the hop tolerant strains eventually recovered as revealed by pHi measurements. Furthermore, a short term protection against hop compounds was obtained for both hop tolerant and sensitive strains, by addition of high concentration of Mn 2+ . Addition of ethanol in combination with hop compounds caused an additional short term increase in damaged subpopulation, but the subsequent growth suggested that the presence of ethanol provides a slight cross resistance toward hop compounds.

Multivariate fractional Poisson processes and compound sums

OpenAIRE

Beghin, Luisa; Macci, Claudio

2015-01-01

In this paper we present multivariate space-time fractional Poisson processes by considering common random time-changes of a (finite-dimensional) vector of independent classical (non-fractional) Poisson processes. In some cases we also consider compound processes. We obtain some equations in terms of some suitable fractional derivatives and fractional difference operators, which provides the extension of known equations for the univariate processes.

New device for time-averaged measurement of volatile organic compounds (VOCs)

Energy Technology Data Exchange (ETDEWEB)

Santiago Sánchez, Noemí; Tejada Alarcón, Sergio; Tortajada Santonja, Rafael; Llorca-Pórcel, Julio, E-mail: julio.llorca@aqualogy.net

2014-07-01

through a glass cell containing adsorbent material where the VOCs are retained. The adsorbent used, made in LABAQUA, is a mixture of alginic acid and activated carbon. Due to its high permeability it allows the passage and retention of THMs in a suitable way, thus solving many of the problems of other common adsorbents. Also, to avoid degradation of the adsorbent, it is wrapped in a low density polyethylene (LDPE) membrane. After a sampling period of between 1 and 14 days, the adsorbent is collected and analyzed in the laboratory to quantify the VOC average concentration. This device resolves some of the limitations of the classical sampling system (spot samples), since we will take into account the fluctuations in the concentration of VOCs by averaging the same over time. This study presents the results obtained by the device for quantifying the VOCs legislated in the Directive 2000/60/EC. We present the validation of linearity over time and the limits of quantification, as well as the results of sample rate (Rs) obtained for each compound. The results demonstrate the high robustness and high sensitivity of the device. In addition the system has been validated in real waste water samples, comparing the results obtained with this device with the values of classical spot sampling, obtaining excellent results. - Highlights: • Device to determine time weighted average concentrations of VOCs in water • This device is presented as an important alternative to spot sampling. • Very low LOD values of VOCs are obtained over 7 days of sampling. • Optimization, validation and application of the device in waters.

Selecting a Response in Task Switching: Testing a Model of Compound Cue Retrieval

Science.gov (United States)

Schneider, Darryl W.; Logan, Gordon D.

2009-01-01

How can a task-appropriate response be selected for an ambiguous target stimulus in task-switching situations? One answer is to use compound cue retrieval, whereby stimuli serve as joint retrieval cues to select a response from long-term memory. In the present study, the authors tested how well a model of compound cue retrieval could account for a…

Core-level XPS studies of Ce and La intermetallic compounds and their implications for the 4f levels of Ce compounds

International Nuclear Information System (INIS)

Freiburg, C.; Fuggle, J.C.; Hillebrecht, F.U.; Zolnierek, Z.; Laesser, R.

1983-01-01

The 3d core hole X-ray photoelectron spectra (XPS) of approximately 30 intermetallic compounds of La and Ce are reported. Transitions to final states with approximately f 0 , f 1 and f 2 character are observed in some Ce compounds (f 0 and f 1 for La compounds). The results are discussed in terms of the current ideas of the influence of f-counts and f-levels hybridization on core level lineshapes. We cannot find an explanatoin of the observed spectra consisted with the ''promotial model'' where the 4f-count varies and 4f electron was thought to be entirely promoted to the Ce 5d6s valence bands in some compounds. There may be some small charge transfer from the f level, however. In conjunction with ideas on screening processes in XPS the observed lineshapes suggest coupling of the 4f electrons to other states is strongest in those compounds previously thought to have f 0 character. This coupling increases despite a large increase in the Ce-Ce distance when Ce is diluted with Ni or Pd. Thus it cannot be due to direct f-f interaction and must be attributed to coupling with the other valence electrons; possibly those centred on the partner sites. (orig./EZ) [de

Four tenets of modern validity theory for medical education assessment and evaluation.

Science.gov (United States)

Royal, Kenneth D

2017-01-01

Validity is considered by many to be the most important criterion for evaluating a set of scores, yet few agree on what exactly the term means. Since the mid-1800s, scholars have been concerned with the notion of validity, but over time, the term has developed a variety of meanings across academic disciplines and contexts. Accordingly, when scholars with different academic backgrounds, many of whom hold deeply entrenched perspectives about validity conceptualizations, converge in the field of medical education assessment, it is a recipe for confusion. Thus, it is important to work toward a consensus about validity in the context of medical education assessment. Thus, the purpose of this work was to present four fundamental tenets of modern validity theory in an effort to establish a framework for scholars in the field of medical education assessment to follow when conceptualizing validity, interpreting validity evidence, and reporting research findings.

The Stability of Bioactive Compounds in Spaceflight Foods

Science.gov (United States)

Cooper, M. R.; Douglas, G. L.

2017-01-01

. Because of the limited number of foods with high concentrations of the bioactive compounds, additional menu variety, formulation optimization, and reduced temperature storage will be required to ensure delivery of several bioactive compounds in the space food system. Validation of stability to five years will enable provisioning of these functional foods within the space food system for a mission to Mars.

Some triterpenic compounds in extracts of Cecropia and Bauhinia species for different sampling years

Directory of Open Access Journals (Sweden)

Marcella Emilia Pietra Schmidt

Full Text Available ABSTRACT The aim of this paper is to provide an overview on the chemical composition of triterpenes in widespread used folk medicine species, through the development and validation of eleven compounds using HPLC-UV detection. The compounds were separated using isocratic elution, on a reverse phase column (Kinetex C18, 250 mm × 4.6 mm, 5 µm with mobile phase consisted of acetonitrile:tetrahydrofuran (90:10, v/v, flow-rate of 0.5 ml/min and detection in 210 nm. Diverse validation parameters were successfully evaluated. The samples of Bauhinia variegata L., B. variegata var. candida Voigt, Fabaceae, Cecropia palmata Willd. and C. obtusa Trécul, Urticaceae, collected in 2012, 2013 and 2014 from Amazon were treated with two different solvents (ethyl acetate and chloroform and analyzed by the proposed method. Stigmasterol, lupeol, β-sitosterol, β-amirin and α-amirin were found in all the studied plants. Highlighting the presence of oleanolic acid, maslinic acid in C. obtusa and C. palmata extracts, erythrodiol only in C. palmata, stigmasteol in B. variegata and α-amirin in B. variegata var. candida. Overall, ethyl acetate showed better performance as the extractor solvent than chloroform. Moreover, it could be used for the quality control of medicinal plants and to assess potential marker compounds.

Quality of longer term mental health facilities in Europe: validation of the quality indicator for rehabilitative care against service users' views.

Directory of Open Access Journals (Sweden)

Helen Killaspy

Full Text Available BACKGROUND: The Quality Indicator for Rehabilitative Care (QuIRC is a staff rated, international toolkit that assesses care in longer term hospital and community based mental health facilities. The QuIRC was developed from review of the international literature, an international Delphi exercise with over 400 service users, practitioners, carers and advocates from ten European countries at different stages of deinstitutionalisation, and review of the care standards in these countries. It can be completed in under an hour by the facility manager and has robust content validity, acceptability and inter-rater reliability. In this study, we investigated the internal validity of the QuIRC. Our aim was to identify the QuIRC domains of care that independently predicted better service user experiences of care. METHOD: At least 20 units providing longer term care for adults with severe mental illness were recruited in each of ten European countries. Service users completed standardised measures of their experiences of care, quality of life, autonomy and the unit's therapeutic milieu. Unit managers completed the QuIRC. Multilevel modelling allowed analysis of associations between service user ratings as dependent variables with unit QuIRC domain ratings as independent variables. RESULTS: 1750/2495 (70% users and the managers of 213 units from across ten European countries participated. QuIRC ratings were positively associated with service users' autonomy and experiences of care. Associations between QuIRC ratings and service users' ratings of their quality of life and the unit's therapeutic milieu were explained by service user characteristics (age, diagnosis and functioning. A hypothetical 10% increase in QuIRC rating resulted in a clinically meaningful improvement in autonomy. CONCLUSIONS: Ratings of the quality of longer term mental health facilities made by service managers were positively associated with service users' autonomy and experiences of care

Steroidal Compounds in Commercial Parenteral Lipid Emulsions

Directory of Open Access Journals (Sweden)

Rafat A. Siddiqui

2012-08-01

Full Text Available Parenteral nutrition lipid emulsions made from various plant oils contain steroidal compounds, called phytosterols. During parenteral administration of lipid emulsions, phytosterols can reach levels in the blood that are many fold higher than during enteral administration. The elevated phytosterol levels have been associated with the development of liver dysfunction and the rare development of liver failure. There is limited information available in the literature related to phytosterol concentrations in lipid emulsions. The objective of the current study was to validate an assay for steroidal compounds found in lipid emulsions and to compare their concentrations in the most commonly used parenteral nutrition lipid emulsions: Liposyn^® II, Liposyn^® III, Lipofundin^® MCT, Lipofundin^® N, Structolipid^®, Intralipid^®, Ivelip^® and ClinOleic^®. Our data demonstrates that concentrations of the various steroidal compounds varied greatly between the eight lipid emulsions, with the olive oil-based lipid emulsion containing the lowest levels of phytosterols and cholesterol, and the highest concentration of squalene. The clinical impression of greater incidences of liver dysfunction with soybean versus MCT/LCT and olive/soy lipid emulsions may be reflective of the levels of phytosterols in these emulsions. This information may help guide future studies and clinical care of patients with lipid emulsion-associated liver dysfunction.

Cross-cultural adaptation, reliability and validity of the Spanish version of the Quality of Life in Adult Cancer Survivors (QLACS) questionnaire: application in a sample of short-term survivors.

Science.gov (United States)

Escobar, Antonio; Trujillo-Martín, Maria del Mar; Rueda, Antonio; Pérez-Ruiz, Elisabeth; Avis, Nancy E; Bilbao, Amaia

2015-11-16

The aim of this study was to validate the Quality of Life in Adult Cancer Survivors (QLACS) in short-term Spanish cancer survivor's patients. Patients with breast, colorectal or prostate cancer that had finished their initial cancer treatment 3 years before the beginning of this study completed QLACS, WHOQOL, Short Form-36, Hospital Anxiety and Depression Scale, EORTC-QLQ-BR23 and EQ-5D. Cultural adaptation was made based on established guidelines. Reliability was evaluated using internal consistency and test-retest. Convergent validity was studied by mean of Pearson's correlation coefficient. Structural validity was determined by a second-order confirmatory factor analysis (CFA) and Rasch analysis was used to assess the unidimensionality of the Generic and Cancer-specific scales. Cronbach's alpha were above 0.7 in all domains and summary scales. Test-retest coefficients were 0.88 for Generic and 0.82 for Cancer-specific summary scales. QLACS generic summary scale was correlated with other generic criterion measures, SF-36 MCS (r = - 0.74) and EQ-VAS (r = - 0.63). QLACS cancer-specific scale had lower values with the same constructs. CFA provided satisfactory fit indices in all cases. The RMSEA value was 0.061 and CFI and TLI values were 0.929 and 0.925, respectively. All factor loadings were higher than 0.40 and statistically significant (P validity and reliability of QLACS questionnaire to be used in short-term cancer survivors.

Computational Homology for Software Validation

Science.gov (United States)

2015-03-01

involving compound data-types. 15. SUBJECT TERMS Abstract datatypes , convergence structure, topological methods, specification logics, hybrid software...composite datatype values are networks strewn through the device’s memory; think of a variable whose type is an array of balanced trees. Some means...structural in nature, is required to rigorously specify the evolution of composite states involving non-numerical, non-metric components. Composite datatypes

Design, synthesis, and validation of a β-turn mimetic library targeting protein-protein and peptide-receptor interactions.

Science.gov (United States)

Whitby, Landon R; Ando, Yoshio; Setola, Vincent; Vogt, Peter K; Roth, Bryan L; Boger, Dale L

2011-07-06

The design and synthesis of a β-turn mimetic library as a key component of a small-molecule library targeting the major recognition motifs involved in protein-protein interactions is described. Analysis of a geometric characterization of 10,245 β-turns in the protein data bank (PDB) suggested that trans-pyrrolidine-3,4-dicarboxamide could serve as an effective and synthetically accessible library template. This was confirmed by initially screening select compounds against a series of peptide-activated GPCRs that recognize a β-turn structure in their endogenous ligands. This validation study was highlighted by identification of both nonbasic and basic small molecules with high affinities (K(i) = 390 and 23 nM, respectively) for the κ-opioid receptor (KOR). Consistent with the screening capabilities of collaborators and following the design validation, the complete library was assembled as 210 mixtures of 20 compounds, providing a total of 4200 compounds designed to mimic all possible permutations of 3 of the 4 residues in a naturally occurring β-turn. Unique to the design and because of the C(2) symmetry of the template, a typical 20 × 20 × 20-mix (8000 compounds prepared as 400 mixtures of 20 compounds) needed to represent 20 variations in the side chains of three amino acid residues reduces to a 210 × 20-mix, thereby simplifying the library synthesis and subsequent screening. The library was prepared using a solution-phase synthetic protocol with liquid-liquid or liquid-solid extractions for purification and conducted on a scale that insures its long-term availability for screening campaigns. Screening the library against the human opioid receptors (KOR, MOR, and DOR) identified not only the activity of library members expected to mimic the opioid receptor peptide ligands but also additional side-chain combinations that provided enhanced receptor binding selectivities (>100-fold) and affinities (as low as K(i) = 80 nM for KOR). A key insight to emerge from

NPACT: Naturally Occurring Plant-based Anti-cancer Compound-Activity-Target database.

Science.gov (United States)

Mangal, Manu; Sagar, Parul; Singh, Harinder; Raghava, Gajendra P S; Agarwal, Subhash M

2013-01-01

Plant-derived molecules have been highly valued by biomedical researchers and pharmaceutical companies for developing drugs, as they are thought to be optimized during evolution. Therefore, we have collected and compiled a central resource Naturally Occurring Plant-based Anti-cancer Compound-Activity-Target database (NPACT, http://crdd.osdd.net/raghava/npact/) that gathers the information related to experimentally validated plant-derived natural compounds exhibiting anti-cancerous activity (in vitro and in vivo), to complement the other databases. It currently contains 1574 compound entries, and each record provides information on their structure, manually curated published data on in vitro and in vivo experiments along with reference for users referral, inhibitory values (IC(50)/ED(50)/EC(50)/GI(50)), properties (physical, elemental and topological), cancer types, cell lines, protein targets, commercial suppliers and drug likeness of compounds. NPACT can easily be browsed or queried using various options, and an online similarity tool has also been made available. Further, to facilitate retrieval of existing data, each record is hyperlinked to similar databases like SuperNatural, Herbal Ingredients' Targets, Comparative Toxicogenomics Database, PubChem and NCI-60 GI(50) data.

NPACT: Naturally Occurring Plant-based Anti-cancer Compound-Activity-Target database

Science.gov (United States)

Mangal, Manu; Sagar, Parul; Singh, Harinder; Raghava, Gajendra P. S.; Agarwal, Subhash M.

2013-01-01

Plant-derived molecules have been highly valued by biomedical researchers and pharmaceutical companies for developing drugs, as they are thought to be optimized during evolution. Therefore, we have collected and compiled a central resource Naturally Occurring Plant-based Anti-cancer Compound-Activity-Target database (NPACT, http://crdd.osdd.net/raghava/npact/) that gathers the information related to experimentally validated plant-derived natural compounds exhibiting anti-cancerous activity (in vitro and in vivo), to complement the other databases. It currently contains 1574 compound entries, and each record provides information on their structure, manually curated published data on in vitro and in vivo experiments along with reference for users referral, inhibitory values (IC50/ED50/EC50/GI50), properties (physical, elemental and topological), cancer types, cell lines, protein targets, commercial suppliers and drug likeness of compounds. NPACT can easily be browsed or queried using various options, and an online similarity tool has also been made available. Further, to facilitate retrieval of existing data, each record is hyperlinked to similar databases like SuperNatural, Herbal Ingredients’ Targets, Comparative Toxicogenomics Database, PubChem and NCI-60 GI50 data. PMID:23203877

Biophysics: for HTS hit validation, chemical lead optimization, and beyond.

Science.gov (United States)

Genick, Christine C; Wright, S Kirk

2017-09-01

There are many challenges to the drug discovery process, including the complexity of the target, its interactions, and how these factors play a role in causing the disease. Traditionally, biophysics has been used for hit validation and chemical lead optimization. With its increased throughput and sensitivity, biophysics is now being applied earlier in this process to empower target characterization and hit finding. Areas covered: In this article, the authors provide an overview of how biophysics can be utilized to assess the quality of the reagents used in screening assays, to validate potential tool compounds, to test the integrity of screening assays, and to create follow-up strategies for compound characterization. They also briefly discuss the utilization of different biophysical methods in hit validation to help avoid the resource consuming pitfalls caused by the lack of hit overlap between biophysical methods. Expert opinion: The use of biophysics early on in the drug discovery process has proven crucial to identifying and characterizing targets of complex nature. It also has enabled the identification and classification of small molecules which interact in an allosteric or covalent manner with the target. By applying biophysics in this manner and at the early stages of this process, the chances of finding chemical leads with novel mechanisms of action are increased. In the future, focused screens with biophysics as a primary readout will become increasingly common.

Validation of biomarkers for the study of environmental carcinogens: a review

DEFF Research Database (Denmark)

Gallo, Valentina; Khan, Aneire; Gonzales, Carlos

2008-01-01

There is a need for validation of biomarkers. Our aim is to review published work on the validation of selected biomarkers: bulky DNA adducts, N-nitroso compounds, 1-hydroxypyrene, and oxidative damage to DNA. A systematic literature search in PubMed was performed. Information on the variability...... and reliability of the laboratory tests used for biomarkers measurements was collected. For the evaluation of the evidence on validation we referred to the ACCE criteria. Little is known about intraindividual variation of DNA adduct measurements, but measurements have a good repeatability irrespective...... of the technique used for their identification; reproducibility improved after the correction for a laboratory factor. A high-sensitivity method is available for the measurement of 1-hydroxypyrene in urine. There is consensus on validation of biomarkers of oxidative damage DNA based on the comet assay...

Metagenomic screening for aromatic compound-responsive transcriptional regulators.

Directory of Open Access Journals (Sweden)

Taku Uchiyama

Full Text Available We applied a metagenomics approach to screen for transcriptional regulators that sense aromatic compounds. The library was constructed by cloning environmental DNA fragments into a promoter-less vector containing green fluorescence protein. Fluorescence-based screening was then performed in the presence of various aromatic compounds. A total of 12 clones were isolated that fluoresced in response to salicylate, 3-methyl catechol, 4-chlorocatechol and chlorohydroquinone. Sequence analysis revealed at least 1 putative transcriptional regulator, excluding 1 clone (CHLO8F. Deletion analysis identified compound-specific transcriptional regulators; namely, 8 LysR-types, 2 two-component-types and 1 AraC-type. Of these, 9 representative clones were selected and their reaction specificities to 18 aromatic compounds were investigated. Overall, our transcriptional regulators were functionally diverse in terms of both specificity and induction rates. LysR- and AraC- type regulators had relatively narrow specificities with high induction rates (5-50 fold, whereas two-component-types had wide specificities with low induction rates (3 fold. Numerous transcriptional regulators have been deposited in sequence databases, but their functions remain largely unknown. Thus, our results add valuable information regarding the sequence-function relationship of transcriptional regulators.

Identification of fluorescent compounds with non-specific binding property via high throughput live cell microscopy.

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Sangeeta Nath

Full Text Available INTRODUCTION: Compounds exhibiting low non-specific intracellular binding or non-stickiness are concomitant with rapid clearing and in high demand for live-cell imaging assays because they allow for intracellular receptor localization with a high signal/noise ratio. The non-stickiness property is particularly important for imaging intracellular receptors due to the equilibria involved. METHOD: Three mammalian cell lines with diverse genetic backgrounds were used to screen a combinatorial fluorescence library via high throughput live cell microscopy for potential ligands with high in- and out-flux properties. The binding properties of ligands identified from the first screen were subsequently validated on plant root hair. A correlative analysis was then performed between each ligand and its corresponding physiochemical and structural properties. RESULTS: The non-stickiness property of each ligand was quantified as a function of the temporal uptake and retention on a cell-by-cell basis. Our data shows that (i mammalian systems can serve as a pre-screening tool for complex plant species that are not amenable to high-throughput imaging; (ii retention and spatial localization of chemical compounds vary within and between each cell line; and (iii the structural similarities of compounds can infer their non-specific binding properties. CONCLUSION: We have validated a protocol for identifying chemical compounds with non-specific binding properties that is testable across diverse species. Further analysis reveals an overlap between the non-stickiness property and the structural similarity of compounds. The net result is a more robust screening assay for identifying desirable ligands that can be used to monitor intracellular localization. Several new applications of the screening protocol and results are also presented.

Analysis of phenolic compounds in different parts of pomegranate (Punica granatum) fruit by HPLC-PDA-ESI/MS and evaluation of their antioxidant activity: application to different Italian varieties.

Science.gov (United States)

Russo, Marina; Fanali, Chiara; Tripodo, Giusy; Dugo, Paola; Muleo, Rosario; Dugo, Laura; De Gara, Laura; Mondello, Luigi

2018-06-01

The analysis of pomegranate phenolic compounds belonging to different classes in different fruit parts was performed by high-performance liquid chromatography coupled with photodiode array and mass spectrometry detection. Two different separation methods were optimized for the analysis of anthocyanins and hydrolyzable tannins along with phenolic acids and flavonoids. Two C 18 columns, core-shell and fully porous particle stationary phases, were used. The parameters for separation of phenolic compounds were optimized considering chromatographic resolution and analysis time. Thirty-five phenolic compounds were found, and 28 of them were tentatively identified as belonging to four different phenolic compound classes; namely, anthocyanins, phenolic acids, hydrolyzable tannins, and flavonoids. Quantitative analysis was performed with a mixture of nine phenolic compounds belonging to phenolic compound classes representative of pomegranate. The method was then fully validated in terms of retention time precision, expressed as the relative standard deviation, limit of detection, limit of quantification, and linearity range. Phenolic compounds were analyzed directly in pomegranate juice, and after solvent extraction with a mixture of water and methanol with a small percentage of acid in peel and pulp samples. The accuracy of the extraction method was also assessed, and satisfactory values were obtained. Finally, the method was used to study identified analytes in pomegranate juice, peel, and pulp of six different Italian varieties and one international variety. Differences in phenolic compound profiles among the different pomegranate parts were observed. Pomegranate peel samples showed a high concentration of phenolic compounds, ellagitannins being the most abundant ones, with respect to pulp and juice samples for each variety. With the same samples, total phenols and antioxidant activity were evaluated through colorimetric assays, and the results were correlated among them.

Effort, symptom validity testing, performance validity testing and traumatic brain injury.

Science.gov (United States)

Bigler, Erin D

2014-01-01

To understand the neurocognitive effects of brain injury, valid neuropsychological test findings are paramount. This review examines the research on what has been referred to a symptom validity testing (SVT). Above a designated cut-score signifies a 'passing' SVT performance which is likely the best indicator of valid neuropsychological test findings. Likewise, substantially below cut-point performance that nears chance or is at chance signifies invalid test performance. Significantly below chance is the sine qua non neuropsychological indicator for malingering. However, the interpretative problems with SVT performance below the cut-point yet far above chance are substantial, as pointed out in this review. This intermediate, border-zone performance on SVT measures is where substantial interpretative challenges exist. Case studies are used to highlight the many areas where additional research is needed. Historical perspectives are reviewed along with the neurobiology of effort. Reasons why performance validity testing (PVT) may be better than the SVT term are reviewed. Advances in neuroimaging techniques may be key in better understanding the meaning of border zone SVT failure. The review demonstrates the problems with rigidity in interpretation with established cut-scores. A better understanding of how certain types of neurological, neuropsychiatric and/or even test conditions may affect SVT performance is needed.

Structure Based Virtual Screening Studies to Identify Novel Potential Compounds for GPR142 and Their Relative Dynamic Analysis for Study of Type 2 Diabetes

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Aman C. Kaushik

2018-02-01

Full Text Available GPR142 (G protein receptor 142 is a novel orphan GPCR (G protein coupled receptor belonging to “Class A” of GPCR family and expressed in β cells of pancreas. In this study, we reported the structure based virtual screening to identify the hit compounds which can be developed as leads for potential agonists. The results were validated through induced fit docking, pharmacophore modeling, and system biology approaches. Since, there is no solved crystal structure of GPR142, we attempted to predict the 3D structure followed by validation and then identification of active site using threading and ab initio methods. Also, structure based virtual screening was performed against a total of 1171519 compounds from different libraries and only top 20 best hit compounds were screened and analyzed. Moreover, the biochemical pathway of GPR142 complex with screened compound2 was also designed and compared with experimental data. Interestingly, compound2 showed an increase in insulin production via Gq mediated signaling pathway suggesting the possible role of novel GPR142 agonists in therapy against type 2 diabetes.

Structure Based Virtual Screening Studies to Identify Novel Potential Compounds for GPR142 and Their Relative Dynamic Analysis for Study of Type 2 Diabetes

Science.gov (United States)

Kaushik, Aman C.; Kumar, Sanjay; Wei, Dong Q.; Sahi, Shakti

2018-02-01

GPR142 (G protein receptor 142) is a novel orphan GPCR (G protein coupled receptor) belonging to ‘Class A’ of GPCR family and expressed in beta cells of pancreas. In this study, we reported the structure based virtual screening to identify the hit compounds which can be developed as leads for potential agonists. The results were validated through induced fit docking, pharmacophore modeling and system biology approaches. Since, there is no solved crystal structure of GPR142, we attempted to predict the 3D structure followed by validation and then identification of active site using threading and ab initio methods. Also, structure based virtual screening was performed against a total of 1171519 compounds from different libraries and only top 20 best hit compounds were screened and analyzed. Moreover, the biochemical pathway of GPR142 complex with screened compound2 was also designed and compared with experimental data. Interestingly, compound2 showed an increase in insulin production via Gq mediated signaling pathway suggesting the possible role of novel GPR142 agonists in therapy against type 2 diabetes.

Multi-step compound contribution to the pre-equilibrium cross section

International Nuclear Information System (INIS)

Mcvoy, K.W.; Hussein, M.S.

1980-03-01

We show that the fluctuation cross section for the generalized-exciton or nested-doorway model can be obtained explicitly and exactly in the limit that doorways of successive classes have very different widths, γ sub(n)>> γ sub(n+1), and that doorways of a given class are overlapping, γ sub(n) > D sub(n). The result is given in terms of experimentally observable quantities, and explicitly separates the compound and pre-compound contributions. It contains the results of previous, more specialized, models a limiting cases. (Author) [pt

FTIR Analysis of Phenolic Compound as Pancreatic Lipase Inhibitor from Inoculated Aquilaria Malaccensis

International Nuclear Information System (INIS)

Nur Fahana Jamahseri; Miradatul Najwa Mohd Rodhi; Nur Hidayah Zulkarnain; Nursyuhada Che Husain; Ahmad Fakhri Syahmi Masruddin

2014-01-01

This research aimed to discover the potential of inoculated Aquilaria malaccensis extract as a new and safe lipase inhibitor. The phenolic compounds in this plant are expected to promote inhibitory activity towards pancreatic lipase enzyme. Inoculated Aquilaria malaccensis was selected for this research, wherein the parts of this species (bark and leaves) were extracted via hydro distillation process. The extracts of this plant which are hydrosol, oil, and leaves were analyzed for phyto chemical compound via Fourier Transform Infrared Spectroscopy (FTIR). FTIR analysis of the extracts of inoculated Aquilaria malccensis revealed the presence of hydroxyl functional group in both leaves and hydrosol extracts but absence in oil. This validate the presence of phenolic compound in hydrosol and leaves extract. Therefore, the leaves and hydrosol extracts have potential as an anti-obesity agent by inhibiting pancreatic lipase. (author)

From Valeriana officinalis to cancer therapy: the success of a bio-sourced compound

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Hamaidia, M.

2016-01-01

Full Text Available Introduction. Over the centuries, bio-sourced compounds isolated from plants, insects and microorganisms have been a potent source of drugs for the treatment of human diseases. Literature. Bio-sourced extracts offer a wide diversity of compounds with a large number of potentially beneficial effects in humans. Serendipity has frequently played a key role in the discovery of new medicines. The canonical discovery of penicillin required both chance and a prepared mind to understand and exploit its potential for the treatment of human infections. Nowadays, most anti-cancer drugs currently in clinical use were at least partly discovered by a "fortunate happenstance". Conclusions. In this review, we recapitulate the story of one of these compounds, 2-propylpentanoic acid, derived from the Valeriana officinalis flowering plant and its path to validation as a cancer treatment.

Bacterial selection for biological control of plant disease: criterion determination and validation

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Monalize Salete Mota

Full Text Available Abstract This study aimed to evaluate the biocontrol potential of bacteria isolated from different plant species and soils. The production of compounds related to phytopathogen biocontrol and/or promotion of plant growth in bacterial isolates was evaluated by measuring the production of antimicrobial compounds (ammonia and antibiosis and hydrolytic enzymes (amylases, lipases, proteases, and chitinases and phosphate solubilization. Of the 1219 bacterial isolates, 92% produced one or more of the eight compounds evaluated, but only 1% of the isolates produced all the compounds. Proteolytic activity was most frequently observed among the bacterial isolates. Among the compounds which often determine the success of biocontrol, 43% produced compounds which inhibit mycelial growth of Monilinia fructicola, but only 11% hydrolyzed chitin. Bacteria from different plant species (rhizosphere or phylloplane exhibited differences in the ability to produce the compounds evaluated. Most bacterial isolates with biocontrol potential were isolated from rhizospheric soil. The most efficient bacteria (producing at least five compounds related to phytopathogen biocontrol and/or plant growth, 86 in total, were evaluated for their biocontrol potential by observing their ability to kill juvenile Mesocriconema xenoplax. Thus, we clearly observed that bacteria that produced more compounds related to phytopathogen biocontrol and/or plant growth had a higher efficacy for nematode biocontrol, which validated the selection strategy used.

Assessment of a robust model protocol with accelerated throughput for a human recombinant full length estrogen receptor-alpha binding assay: protocol optimization and intralaboratory assay performance as initial steps towards validation.

Science.gov (United States)

Freyberger, Alexius; Wilson, Vickie; Weimer, Marc; Tan, Shirlee; Tran, Hoai-Son; Ahr, Hans-Jürgen

2010-08-01

Despite about two decades of research in the field of endocrine active compounds, still no validated human recombinant (hr) estrogen receptor-alpha (ERalpha) binding assay is available, although hr-ERalpha is available from several sources. In a joint effort, US EPA and Bayer Schering Pharma with funding from the EU-sponsored 6th framework project, ReProTect, developed a model protocol for such a binding assay. Important features of this assay are the use of a full length hr-ERalpha and performance in a 96-well plate format. A full length hr-ERalpha was chosen, as it was considered to provide the most accurate and human-relevant results, whereas truncated receptors could perform differently. Besides three reference compounds [17beta-estradiol, norethynodrel, dibutylphthalate] nine test compounds with different affinities for the ERalpha [diethylstilbestrol (DES), ethynylestradiol, meso-hexestrol, equol, genistein, o,p'-DDT, nonylphenol, n-butylparaben, and corticosterone] were used to explore the performance of the assay. Three independent experiments per compound were performed on different days, and dilutions of test compounds from deep-frozen stocks, solutions of radiolabeled ligand and receptor preparation were freshly prepared for each experiment. The ERalpha binding properties of reference and test compounds were well detected. As expected dibutylphthalate and corticosterone were non-binders in this assay. In terms of the relative ranking of binding affinities, there was good agreement with published data obtained from experiments using a human recombinant ERalpha ligand binding domain. Irrespective of the chemical nature of the compound, individual IC(50)-values for a given compound varied by not more than a factor of 2.5. Our data demonstrate that the assay was robust and reliably ranked compounds with strong, weak, and no affinity for the ERalpha with high accuracy. It avoids the manipulation and use of animals, i.e., the preparation of uterine cytosol as

Organic and total mercury determination in sediments by cold vapor atomic absorption spectrometry: methodology validation and uncertainty measurements

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Robson L. Franklin

2012-01-01

Full Text Available The purpose of the present study was to validate a method for organic Hg determination in sediment. The procedure for organic Hg was adapted from literature, where the organomercurial compounds were extracted with dichloromethane in acid medium and subsequent destruction of organic compounds by bromine chloride. Total Hg was performed according to 3051A USEPA methodology. Mercury quantification for both methodologies was then performed by CVAAS. Methodology validation was verified by analyzing certified reference materials for total Hg and methylmercury. The uncertainties for both methodologies were calculated. The quantification limit of 3.3 µg kg-1 was found for organic Hg by CVAAS.

Candidacidal Action of CF66I, an Antifungal Compound Produced ...

African Journals Online (AJOL)

Erah

terms of efficacy and/or safety is needed. During the search for .... and the formation of interconnected cells. Cell surfaces were wrinkled, and ... roughening and disruption (Fig 3b, 3c and. 3d). In addition, this compound caused the clusters of ...

Validation of a Supplemental Reading Intervention for First-Grade Children

Science.gov (United States)

Case, Lisa Pericola; Speece, Deborah L.; Silverman, Rebecca; Ritchey, Kristen D.; Schatschneider, Christopher; Cooper, David H.; Montanaro, Elizabeth; Jacobs, Dawn

2010-01-01

This experimental study was designed to validate a short-term supplemental reading intervention for at-risk first-grade children. Although substantial research on long-term supplemental reading interventions exists, less is known about short-term interventions. Thirty first-grade children were randomly assigned to intervention or control…

Validity of pre and post-term birth rates based on the date of last menstrual period compared to early obstetric ultrasonography

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Maria Nilza Lima Medeiros

2015-04-01

Full Text Available The aim of this study was to assess the validity of the last menstrual period (LMP estimate in determining pre and post-term birth rates, in a prenatal cohort from two Brazilian cities, São Luís and Ribeirão Preto. Pregnant women with a single fetus and less than 20 weeks' gestation by obstetric ultrasonography who received prenatal care in 2010 and 2011 were included. The LMP was obtained on two occasions (at 22-25 weeks gestation and after birth. The sensitivity of LMP obtained prenatally to estimate the preterm birth rate was 65.6% in São Luís and 78.7% in Ribeirão Preto and the positive predictive value was 57.3% in São Luís and 73.3% in Ribeirão Preto. LMP errors in identifying preterm birth were lower in the more developed city, Ribeirão Preto. The sensitivity and positive predictive value of LMP for the estimate of the post-term birth rate was very low and tended to overestimate it. LMP can be used with some errors to identify the preterm birth rate when obstetric ultrasonography is not available, but is not suitable for predicting post-term birth.

Isolation, characterization and HPLC quantification of compounds from Aquilegia fragrans Benth: Their in vitro antibacterial activities against bovine mastitis pathogens.

Science.gov (United States)

Mushtaq, Saleem; Aga, Mushtaq A; Qazi, Parvaiz H; Ali, Md Niamat; Shah, Aabid Manzoor; Lone, Sajad Ahmad; Shah, Aiyatullah; Hussain, Aehtesham; Rasool, Faheem; Dar, Hafizullah; Shah, Zeeshan Hamid; Lone, Shabir H

2016-02-03

The underground parts of Aquilegia fragrans are traditionally used for the treatment of wounds and various inflammatory diseases like bovine mastitis. However, there are no reports on the phytochemical characterization and antibacterial studies of A. fragrans. To isolate compounds from the methanol extract of the underground parts of A. fragrans and determine their antibacterial activity against the pathogens of bovine mastitis. The study was undertaken in order to scientifically validate the traditional use of A. fragrans. Five compounds were isolated from the methanol extract of the underground parts of A. fragrans using silica gel column chromatography. Structural elucidation of the isolated compounds was done using spectral data analysis and comparison with literature. High performance liquid chromatography (HPLC) was used for the qualitative and quantitative determination of isolated compounds in the crude methanol extract. The methanol extract and isolated compounds were evaluated for antibacterial activities against mastitis pathogens using broth micro-dilution technique. The five isolated compounds were identified as (1) 2, 4-dihydroxyphenylacetic acid methyl ester (2) β-sitosterol (3) Aquilegiolide (4) Glochidionolactone-A and (5) Magnoflorine. A quick and sensitive HPLC method was developed for the first time for qualitative and quantitative determination of four isolated marker compounds from A. fragrans. The crude methanol extract and compound 5 exhibited weak antibacterial activities that varied between the bacterial species (MIC=500-3000 µg/ml). The above results show that the crude methanol extract and isolated compounds from A. fragrans exhibit weak antibacterial activities. Further phytochemical and pharmacological studies are required for proper scientific validation of the folk use of this plant species in the treatment of various inflammatory diseases like bovine mastitis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Automatic Validation of Protocol Narration

DEFF Research Database (Denmark)

Bodei, Chiara; Buchholtz, Mikael; Degano, Pierpablo

2003-01-01

We perform a systematic expansion of protocol narrations into terms of a process algebra in order to make precise some of the detailed checks that need to be made in a protocol. We then apply static analysis technology to develop an automatic validation procedure for protocols. Finally, we...

Solubility of carbon monoxide in bio-oil compounds

International Nuclear Information System (INIS)

Qureshi, Muhammad Saad; Le Nedelec, Tom; Guerrero-Amaya, Hernando; Uusi-Kyyny, Petri; Richon, Dominique; Alopaeus, Ville

2017-01-01

Highlights: • CO solubility was measured in four bio-oil compounds using static-analytic VLE equipment. • A comparison on the performance of different EoS (PC-SAFT, SRK and PR) was made. • Modelling of polar compounds with Polar PC-SAFT was tested. • Polar PC-SAFT is not needed for weakly polar compounds (μ < 1.0 D). - Abstract: The solubility of carbon monoxide is measured in four different bio-oil compounds (furan, diacetyl, 2-methylfuran, and trans-crotonaldehyde) at temperatures (273.15, 283.15, 298.15, and 323.15 K) and pressures up to 8 MPa using a static-analytical VLE measurement method. The equipment was validated by measuring the solubility of CO 2 in methanol at 298.15 K and pressures (P = 2.9–5.7 MPa). The results were compared with the abundantly available literature values. PC-SAFT, Polar PC-SAFT (PPC-SAFT), and Cubic (SRK, PR) EoS, part of commercial process simulator Aspen Plus V. 8.6, are used here for modelling purpose. The pure component parameters needed for PC-SAFT and PPC-SAFT EoS models, are regressed using the experimental liquid density and vapour pressure data of the pure components. It was observed that furan, 2-methylfuran and diacetyl, having weak dipole moments (μ < 1.0 D), could be modelled reasonably well without the addition of polar contribution using conventional PC-SAFT, while it is recommended to use PPC-SAFT for the description of a polar compound like trans-crotonaldehyde (μ ∼ 3.67 D). It was observed that SRK and PR EoS have similar predictive ability in comparison to PC-SAFT for a mixture of CO with weakly polar compounds in this study. A comparison between the performances of EoS models was made in two ways: first by setting the binary interaction parameter k ij to zero, and second by adjusting a temperature-dependent binary interaction parameter (k ij ). All the models perform with comparable accuracy with adjusted binary interaction parameters. However, due to the large differences between the chemical and

Natural Compounds as Regulators of the Cancer Cell Metabolism

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Claudia Cerella

2013-01-01

Full Text Available Even though altered metabolism is an “old” physiological mechanism, only recently its targeting became a therapeutically interesting strategy and by now it is considered an emerging hallmark of cancer. Nevertheless, a very poor number of compounds are under investigation as potential modulators of cell metabolism. Candidate agents should display selectivity of action towards cancer cells without side effects. This ideal favorable profile would perfectly overlap the requisites of new anticancer therapies and chemopreventive strategies as well. Nature represents a still largely unexplored source of bioactive molecules with a therapeutic potential. Many of these compounds have already been characterized for their multiple anticancer activities. Many of them are absorbed with the diet and therefore possess a known profile in terms of tolerability and bioavailability compared to newly synthetized chemical compounds. The discovery of important cross-talks between mediators of the most therapeutically targeted aberrancies in cancer (i.e., cell proliferation, survival, and migration and the metabolic machinery allows to predict the possibility that many anticancer activities ascribed to a number of natural compounds may be due, in part, to their ability of modulating metabolic pathways. In this review, we attempt an overview of what is currently known about the potential of natural compounds as modulators of cancer cell metabolism.

Fingerprinting and validation of a LC-DAD method for the analysis of biflavanones in Garcinia kola-based antimalarial improved traditional medicines.

Science.gov (United States)

Tshibangu, P Tshisekedi; Kapepula, P Mutwale; Kapinga, M J Kabongo; Lupona, H Kabika; Ngombe, N Kabamba; Kalenda, Dibungi T; Jansen, O; Wauters, J N; Tits, M; Angenot, L; Rozet, E; Hubert, Ph; Marini, R D; Frédérich, M

2016-09-05

African populations use traditional medicines in their initial attempt to treat a range of diseases. Nevertheless, accurate knowledge of the composition of these drugs remains a challenge in terms of ensuring the health of population and in order to advance towards improved traditional medicines (ITMs). In this paper chromatographic methods were developed for qualitative and quantitative analyses of a per os antimalarial ITM containing Garcinia kola. The identified analytical markers were used to establish TLC and HPLC fingerprints. G. kola seeds were analysed by HPLC to confirm the identity of the extract used by the Congolese manufacturer in the ITM. The main compounds (GB1, GB2, GB-1a and Kolaflavanone) were isolated by preparative TLC and identified by UPLC-MS and NMR. For the quantification of the major compound GB1, a simple and rapid experimental design was applied to develop an LC method, and then its validation was demonstrated using the total error strategy with the accuracy profile as a decision tool. The accurate results were observed within 0.14-0.45mg/mL range of GB1 expressed as naringenin. The extracts used in several batches of the analysed oral solutions contained GB1 (expressed as naringenin) within 2.04-2.43%. Both the fingerprints and the validated LC-DAD were found suitable for the quality control of G. kola-based raw material and finished products, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Estimating the physicochemical properties of polyhalogenated aromatic and aliphatic compounds using UPPER: part 1. Boiling point and melting point.

Science.gov (United States)

Admire, Brittany; Lian, Bo; Yalkowsky, Samuel H

2015-01-01

The UPPER (Unified Physicochemical Property Estimation Relationships) model uses enthalpic and entropic parameters to estimate 20 biologically relevant properties of organic compounds. The model has been validated by Lian and Yalkowsky on a data set of 700 hydrocarbons. The aim of this work is to expand the UPPER model to estimate the boiling and melting points of polyhalogenated compounds. In this work, 19 new group descriptors are defined and used to predict the transition temperatures of an additional 1288 compounds. The boiling points of 808 and the melting points of 742 polyhalogenated compounds are predicted with average absolute errors of 13.56 K and 25.85 K, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Promises of Machine Learning Approaches in Prediction of Absorption of Compounds.

Science.gov (United States)

Kumar, Rajnish; Sharma, Anju; Siddiqui, Mohammed Haris; Tiwari, Rajesh Kumar

2018-01-01

The Machine Learning (ML) is one of the fastest developing techniques in the prediction and evaluation of important pharmacokinetic properties such as absorption, distribution, metabolism and excretion. The availability of a large number of robust validation techniques for prediction models devoted to pharmacokinetics has significantly enhanced the trust and authenticity in ML approaches. There is a series of prediction models generated and used for rapid screening of compounds on the basis of absorption in last one decade. Prediction of absorption of compounds using ML models has great potential across the pharmaceutical industry as a non-animal alternative to predict absorption. However, these prediction models still have to go far ahead to develop the confidence similar to conventional experimental methods for estimation of drug absorption. Some of the general concerns are selection of appropriate ML methods and validation techniques in addition to selecting relevant descriptors and authentic data sets for the generation of prediction models. The current review explores published models of ML for the prediction of absorption using physicochemical properties as descriptors and their important conclusions. In addition, some critical challenges in acceptance of ML models for absorption are also discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Volatile Compounds and Sensory Profiles of Monovarietal Virgin Olive Oil from Buža, Črna and Rosinjola Cultivars in Istria (Croatia

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Barbara Sladonja

2012-01-01

Full Text Available The volatile compounds found in virgin olive oil, mainly C6 and C5 volatile compounds biogenerated from polyunsaturated fatty acids through the lipoxygenase pathway, are responsible for their particular aroma. The composition of volatile compounds in olive oil depends on the cultivar, the ripening degree of the fruits and processing conditions. Among many different autochthonous cultivars in Istria (Croatia, some of the most prevalent are Buža, Črna and Rosinjola. The volatiles and sensory characteristics of their monovarietal virgin olive oil are little known. Therefore, fruits from these three cultivars were handpicked at the same ripening degree and processed under the same conditions. Quantitative descriptive sensory analysis of monovarietal virgin olive oil was carried out by the panel. Volatile composition was evaluated by headspace solid phase microextraction-gas chromatography, previously optimized and validated. The main parameters affecting effectiveness, time and temperature of extraction were optimized. The extraction procedure showed detection and quantification limits, as well as linear ranges adequate for the analysis of selected volatile compounds. Good precision was obtained both in terms of intra-day repeatability (relative standard deviations generally lower than 7 % and inter-day precision. The tested types of monovarietal olive oil showed different volatile profiles, although E-2-hexenal was the main compound in all samples. Buža oil was the richest in total C6 and C5 volatile compounds. The results show that the most important contributors to the olive oil aroma (odour activity value >1.0 were 1-penten-3-one, E-2-hexenal, hexanal, hexanol, Z-3-hexen-1-ol and Z-2-penten-1-ol. These chemical findings were compared with those provided by the panel test. Buža had the highest intensity of sensory characteristic 'other ripe fruits' and Rosinjola had the highest intensity of sensory characteristic 'bitter'. All results show

Review of pulmonary toxicity of indium compounds to animals and humans

International Nuclear Information System (INIS)

Tanaka, Akiyo; Hirata, Miyuki; Kiyohara, Yutaka; Nakano, Makiko; Omae, Kazuyuki; Shiratani, Masaharu; Koga, Kazunori

2010-01-01

Due to the increased production of ITO, the potential health hazards arising from occupational exposure to this material have attracted much attention. This review consists of three parts: 1) toxic effects of indium compounds on animals, 2) toxic effects of indium compounds on humans, and 3) recommendations for preventing exposure to indium compounds in the workplace. Available data have indicated that insoluble form of indium compounds, such as ITO, indium arsenide (InAs) and indium phosphide (InP), can be toxic to animals. Furthermore, InP has demonstrated clear evidence of carcinogenic potential in long-term inhalation studies using experimental animals. As for the dangers to humans, some data are available concerning adverse health effects to workers who have been exposed to indium-containing particles. The Japan Society for Occupational Health recommended the value of 3 μg/L of indium in serum as the occupational exposure limit based on biological monitoring to preventing adverse health effects in workers resulting from occupational exposure to indium compounds. Accordingly, it is essential that much greater attention is focused on human exposure to indium compounds, and precautions against possible exposure to indium compounds are most important with regard to health management among indium-handling workers.

Validity, Reliability, and the Questionable Role of Psychometrics in Plastic Surgery

Science.gov (United States)

2014-01-01

Summary: This report examines the meaning of validity and reliability and the role of psychometrics in plastic surgery. Study titles increasingly include the word “valid” to support the authors’ claims. Studies by other investigators may be labeled “not validated.” Validity simply refers to the ability of a device to measure what it intends to measure. Validity is not an intrinsic test property. It is a relative term most credibly assigned by the independent user. Similarly, the word “reliable” is subject to interpretation. In psychometrics, its meaning is synonymous with “reproducible.” The definitions of valid and reliable are analogous to accuracy and precision. Reliability (both the reliability of the data and the consistency of measurements) is a prerequisite for validity. Outcome measures in plastic surgery are intended to be surveys, not tests. The role of psychometric modeling in plastic surgery is unclear, and this discipline introduces difficult jargon that can discourage investigators. Standard statistical tests suffice. The unambiguous term “reproducible” is preferred when discussing data consistency. Study design and methodology are essential considerations when assessing a study’s validity. PMID:25289354

Validity, Reliability, and the Questionable Role of Psychometrics in Plastic Surgery

Directory of Open Access Journals (Sweden)

Eric Swanson, MD

2014-06-01

Full Text Available Summary: This report examines the meaning of validity and reliability and the role of psychometrics in plastic surgery. Study titles increasingly include the word “valid” to support the authors’ claims. Studies by other investigators may be labeled “not validated.” Validity simply refers to the ability of a device to measure what it intends to measure. Validity is not an intrinsic test property. It is a relative term most credibly assigned by the independent user. Similarly, the word “reliable” is subject to interpretation. In psychometrics, its meaning is synonymous with “reproducible.” The definitions of valid and reliable are analogous to accuracy and precision. Reliability (both the reliability of the data and the consistency of measurements is a prerequisite for validity. Outcome measures in plastic surgery are intended to be surveys, not tests. The role of psychometric modeling in plastic surgery is unclear, and this discipline introduces difficult jargon that can discourage investigators. Standard statistical tests suffice. The unambiguous term “reproducible” is preferred when discussing data consistency. Study design and methodology are essential considerations when assessing a study’s validity.

Sanskrit Compound Processor

Science.gov (United States)

Kumar, Anil; Mittal, Vipul; Kulkarni, Amba

Sanskrit is very rich in compound formation. Typically a compound does not code the relation between its components explicitly. To understand the meaning of a compound, it is necessary to identify its components, discover the relations between them and finally generate a paraphrase of the compound. In this paper, we discuss the automatic segmentation and type identification of a compound using simple statistics that results from the manually annotated data.

Efficient Conversion of Oximes to the Corresponding Carbonyl Compounds with Tetrabutylammonium Chromate under Aprotic Conditions

International Nuclear Information System (INIS)

Pourali, Ali Reza; Goli, Arezou

2006-01-01

The solubility in several solvents, mildness, simple work-up and absence of side reactions provide advantages of using TBAC in deoximation reactions. This is an efficient and selective method for homogeneous deoximation of structurally different compounds under the moderately acidic and aprotic conditions in high yields. Regeneration of ketones and aldehydes from their oximes has assumed added importance since the discovery of the Barton reaction in which oximes are produced at non-activated hydrocarbon sites. Also, their synthesis from non-carbonyl compounds, such as by nitrosation of an active methylene group, nitrosation of an α-halo carbonyl compound and condensation of a nitro-alkene with an aldehyde provides a valid alternative pathway to carbonyl compounds. Therefore, there has been a continued interest in the effective regeneration of carbonyl compounds from the corresponding oximes especially under mild conditions. Oxidative and reductive methods have been found to show advantages over the classical hydrolytic methods. Although many oxidizing agents have been used, only a limited number of methods are efficient because of the low solubility of these metallic reagents in most organic solvents

Geographical provenance of palm oil by fatty acid and volatile compound fingerprinting techniques.

Science.gov (United States)

Tres, A; Ruiz-Samblas, C; van der Veer, G; van Ruth, S M

2013-04-15

Analytical methods are required in addition to administrative controls to verify the geographical origin of vegetable oils such as palm oil in an objective manner. In this study the application of fatty acid and volatile organic compound fingerprinting in combination with chemometrics have been applied to verify the geographical origin of crude palm oil (continental scale). For this purpose 94 crude palm oil samples were collected from South East Asia (55), South America (11) and Africa (28). Partial least squares discriminant analysis (PLS-DA) was used to develop a hierarchical classification model by combining two consecutive binary PLS-DA models. First, a PLS-DA model was built to distinguish South East Asian from non-South East Asian palm oil samples. Then a second model was developed, only for the non-Asian samples, to discriminate African from South American crude palm oil. Models were externally validated by using them to predict the identity of new authentic samples. The fatty acid fingerprinting model revealed three misclassified samples. The volatile compound fingerprinting models showed an 88%, 100% and 100% accuracy for the South East Asian, African and American class, respectively. The verification of the geographical origin of crude palm oil is feasible by fatty acid and volatile compound fingerprinting. Further research is required to further validate the approach and to increase its spatial specificity to country/province scale. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Conceptual Model of Calculating the Return Period of the Costs for Creation of the Enterprise’s Economic Security Service in the Short-Term Period

Directory of Open Access Journals (Sweden)

Melikhova Tetiana O.

2018-03-01

Full Text Available Determination of the return period of the costs, advanced for the creation of economic security service of enterprise during a year, involves consideration of interaction of the conditional money flow, accumulated for a certain number of months, and the constant costs. The main component of the constant costs are the annual depreciation deductions. The return period is considered as gross, net, valid, and specified. The gross (net, valid, and specified return period is the time, wherein the gross conditional money flow, equal to the advanced costs, will be accumulated. The gross return period, taking account of the effect of time factor, is proposed to be defined as the ratio of annual depreciation deductions increased by the annual compounding coefficient to the conditional average monthly gross money flow, increased by the average monthly inflation index. As for the short-term period, a relationship between the gross, net, valid, and specified return periods of the costs, advanced to the creation of the economic security service, has been identified. The net (valid, specified return period is equal to the gross period adjusted to the coefficient of excess of the gross conditional money flow, accumulated in the gross period, over the net (valid, specified conditional cash flow.

Development of an analytical method coupling cell membrane chromatography with gas chromatography-mass spectrometry via microextraction by packed sorbent and its application in the screening of volatile active compounds in natural products.

Science.gov (United States)

Li, Miao; Wang, Sicen; He, Langchong

2015-01-01

Natural products (NPs) are important sources of lead compounds in modern drug discovery. To facilitate the screening of volatile active compounds in NPs, we have developed a new biochromatography method that uses rat vascular smooth muscle cells (VSMC), which are rich in L-type calcium channels (LCC), to prepare the stationary phase. This integrated method, which couples cell membrane chromatography (CMC) with gas chromatography-mass spectrometry (GC-MS) via microextraction by packed sorbent (MEPS) technology, has been termed VSMC/CMC-MEPS-GC-MS. Methodological validation confirmed its specificity, reliability and convenience. Screening results for Radix Angelicae Dahuricae and Fructus Cnidii obtained using VSMC/CMC-MEPS-GC-MS were consistent with those obtained using VSMC/CMC-offline-GC-MS. MEPS connection plays as simplified solid-phase extraction and replaces the uncontrollable evaporation operation in reported offline connections, so our new method is supposed to be more efficient and reliable than the offline ones, especially for compounds that are volatile, thermally unstable or difficult to purify. In application, senkyunolide A and ligustilide were preliminary identified as the volatile active components in Rhizoma Chuanxiong. We have thus confirmed the suitability of VSMC/CMC-MEPS-GC-MS for volatile active compounds screening in NP. Copyright © 2014 Elsevier B.V. All rights reserved.

A Compound Sensor for Simultaneous Measurement of Packing Density and Moisture Content of Silage.

Science.gov (United States)

Meng, Delun; Meng, Fanjia; Sun, Wei; Deng, Shuang

2017-12-28

Packing density and moisture content are important factors in investigating the ensiling quality. Low packing density is a major cause of loss of sugar content. The moisture content also plays a determinant role in biomass degradation. To comprehensively evaluate the ensiling quality, this study focused on developing a compound sensor. In it, moisture electrodes and strain gauges were embedded into an ASABE Standard small cone for the simultaneous measurements of the penetration resistance (PR) and moisture content (MC) of silage. In order to evaluate the performance of the designed sensor and the theoretical analysis being used, relevant calibration and validation tests were conducted. The determination coefficients are 0.996 and 0.992 for PR calibration and 0.934 for MC calibration. The validation indicated that this measurement technique could determine the packing density and moisture content of the silage simultaneously and eliminate the influence of the friction between the penetration shaft and silage. In this study, we not only design a compound sensor but also provide an alternative way to investigate the ensiling quality which would be useful for further silage research.

QSPR Models for Predicting Log Pliver Values for Volatile Organic Compounds Combining Statistical Methods and Domain Knowledge

Directory of Open Access Journals (Sweden)

Mónica F. Díaz

2012-12-01

Full Text Available Volatile organic compounds (VOCs are contained in a variety of chemicals that can be found in household products and may have undesirable effects on health. Thereby, it is important to model blood-to-liver partition coefficients (log Pliver for VOCs in a fast and inexpensive way. In this paper, we present two new quantitative structure-property relationship (QSPR models for the prediction of log Pliver, where we also propose a hybrid approach for the selection of the descriptors. This hybrid methodology combines a machine learning method with a manual selection based on expert knowledge. This allows obtaining a set of descriptors that is interpretable in physicochemical terms. Our regression models were trained using decision trees and neural networks and validated using an external test set. Results show high prediction accuracy compared to previous log Pliver models, and the descriptor selection approach provides a means to get a small set of descriptors that is in agreement with theoretical understanding of the target property.

Optical spectroscopy of f-element compounds

International Nuclear Information System (INIS)

Carnall, W.T.

1978-01-01

It is noted that the energies and intensities of transitions observed in the optical spectra of lanthanide (Ln) and actinide (An) compounds can typically be measured with a high degree of accuracy. The observed transitions can then be directly represented as upper state energy levels where the structure is induced by the environment. A discussion is presented of the systematic theoretical interpretation of these transitions both in terms of energy level structure and transition probability. Particularly for the trivalent lanthanides and actinides, the detail to which the interpretation can be carried is unique in the periodic table. The electronic structure of organometallic lanthanides and actinides is emphasized in the discussion. It is made clear that this type of ligand does not present any unique interpretive problems. The basic framework of the interpretation is not dependent upon the specific ionic environment. On the other hand, organometallic compounds represent a particularly interesting group in which to study excited state relaxation

A three-stage-integrative approach for the identification of potential hepatotoxic compounds from botanical products.

Science.gov (United States)

Jin, Yecheng; Zhao, Xiaoping; Zhang, Yufeng; Li, Xiang; Nie, Xiaojing; Wang, Yi; Fan, Xiaohui

2011-05-01

With the increasing use of herbal medicines and dietary supplements, intensive concerns about their potential toxicities have been raised. Screening and identifying the toxic compounds from these botanical products composed by hundreds of components have become a critical but challenging problem. In this study, 3 methods, including fraction separation, an in-house-developed fluorescein diacetate-based automatic microscopy screening (FAMS) platform, and liquid chromatography-mass spectrometry-based compounds identification were integrated within the Three-Stage-Integrative (TSI) approach for the identification of potential hepatotoxicants from botanical products. The sensitivity and linear range of FAMS assay was validated and compared with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay by previously reported hepatotoxic compounds. The success of TSI approach was further demonstrated by its application to Fructus aristolochiae. Aristolochic acid IVa and aristolodione were tentatively identified to be potential hepatotoxicants in this plant. These applications suggested that our TSI approach provides an effective tool for identifying potential toxic compounds from botanical products.

BIOGENIC VS. ABIOGENIC ISOTOPE SIGNATURES OF REDUCED CARBON COMPOUNDS: A LESSON FROM HYDROTHERMAL SYNTHESIS EXPERIMENTS

International Nuclear Information System (INIS)

Horita, J.

2001-01-01

With growing interest in and demonstrated cases of inorganic hydrothermal synthesis of reduced or organic carbon compounds from CO and CO(sub 2), it becomes crucial to establish geochemical criteria to distinguish reduced/organic carbon compounds of abiogenic origin from those of biogenic origin with overwhelming abundances on the surface and in subsurface of the Earth. Chemical and isotopic compositions, particularly(sup 13)C/(sup 12)C ratios, of reduced/organic carbon compounds have been widely utilized for deducing the origins and formation pathways of these compounds. An example is isotopic and C(sub 1)/(C(sub 2)+C(sub 3)) ratios of natural gases, which have been used to distinguish bacterial, thermogenic, and possible abiogenic origins. Another example is that ancient graphitic carbon with(delta)(sup 13)C values c-25per thousand has been considered of biogenic origin. Although these criteria could be largely valid, growing data including those from our hydrothermal experiments suggest that a great caution must be exercised

DDML Schema Validation

Science.gov (United States)

2016-02-08

XML schema govern DDML instance documents. For information about XML, refer to RCC 125-15, XML Style Guide.2 Figure 4 provides an XML snippet of a...we have documented three main types of information .  User Stories: A user story describes a specific requirement of the schema in the terms of a...instance document is a schema -valid XML file that completely describes the information in the test case in a manner that satisfies the user story

Bond-based linear indices in QSAR: computational discovery of novel anti-trichomonal compounds

Science.gov (United States)

Marrero-Ponce, Yovani; Meneses-Marcel, Alfredo; Rivera-Borroto, Oscar M.; García-Domenech, Ramón; De Julián-Ortiz, Jesus Vicente; Montero, Alina; Escario, José Antonio; Barrio, Alicia Gómez; Pereira, David Montero; Nogal, Juan José; Grau, Ricardo; Torrens, Francisco; Vogel, Christian; Arán, Vicente J.

2008-08-01

Trichomonas vaginalis ( Tv) is the causative agent of the most common, non-viral, sexually transmitted disease in women and men worldwide. Since 1959, metronidazole (MTZ) has been the drug of choice in the systemic treatment of trichomoniasis. However, resistance to MTZ in some patients and the great cost associated with the development of new trichomonacidals make necessary the development of computational methods that shorten the drug discovery pipeline. Toward this end, bond-based linear indices, new TOMOCOMD-CARDD molecular descriptors, and linear discriminant analysis were used to discover novel trichomonacidal chemicals. The obtained models, using non-stochastic and stochastic indices, are able to classify correctly 89.01% (87.50%) and 82.42% (84.38%) of the chemicals in the training (test) sets, respectively. These results validate the models for their use in the ligand-based virtual screening. In addition, they show large Matthews' correlation coefficients ( C) of 0.78 (0.71) and 0.65 (0.65) for the training (test) sets, correspondingly. The result of predictions on the 10% full-out cross-validation test also evidences the robustness of the obtained models. Later, both models are applied to the virtual screening of 12 compounds already proved against Tv. As a result, they correctly classify 10 out of 12 (83.33%) and 9 out of 12 (75.00%) of the chemicals, respectively; which is the most important criterion for validating the models. Besides, these classification functions are applied to a library of seven chemicals in order to find novel antitrichomonal agents. These compounds are synthesized and tested for in vitro activity against Tv. As a result, experimental observations approached to theoretical predictions, since it was obtained a correct classification of 85.71% (6 out of 7) of the chemicals. Moreover, out of the seven compounds that are screened, synthesized and biologically assayed, six compounds (VA7-34, VA7-35, VA7-37, VA7-38, VA7-68, VA7-70) show

Design and Analysis of CMOS-Compatible III-V Compound Electron-Hole Bilayer Tunneling Field-Effect Transistor for Ultra-Low-Power Applications.

Science.gov (United States)

Kim, Sung Yoon; Seo, Jae Hwa; Yoon, Young Jun; Lee, Ho-Young; Lee, Seong Min; Cho, Seongjae; Kang, In Man

2015-10-01

In this work, we design and analyze complementary metal-oxide-semiconductor (CMOS)-compatible III-V compound electron-hole bilayer (EHB) tunneling field-effect transistors (TFETs) by using two-dimensional (2D) technology computer-aided design (TCAD) simulations. A recently proposed EHB TFET exploits a bias-induced band-to-band tunneling (BTBT) across the electron-hole bilayer by an electric field from the top and bottom gates. This is in contrast to conventional planar p(+)-p(-)-n TFETs, which utilize BTBT across the source-to-channel junction. We applied III-V compound semiconductor materials to the EHB TFETs in order to enhance the current drivability and switching performance. Devices based on various compound semiconductor materials have been designed and analyzed in terms of their primary DC characteristics. In addition, the operational principles were validated by close examination of the electron concentrations and energy-band diagrams under various operation conditions. The simulation results of the optimally designed In0.533Ga0.47As EHB TFET show outstanding performance, with an on-state current (Ion) of 249.5 μA/μm, subthreshold swing (S) of 11.4 mV/dec, and threshold voltage (Vth) of 50 mV at VDS = 0.5 V. Based on the DC-optimized InGaAs EHB TFET, the CMOS inverter circuit was simulated in views of static and dynamic behaviors of the p-channel device with exchanges between top and bottom gates or between source and drain electrodes maintaining the device structure.

Certification, Accreditation, and Credentialing for 503A Compounding Pharmacies.

Science.gov (United States)

Pritchett, Jon; McCrory, Gary; Kraemer, Cheri; Jensen, Brenda; Allen, Loyd V

2018-01-01

The terms certification, accreditation, and credentialing are often used interchangeably when they apply to compounding-pharmacy qualifications, but they are not synonymous. The reasons for obtaining each, the requirements for each, and the benefits of each differ. Achieving such distinctions can negatively or positively affect the status of a pharmacy among peers and prescribers as well as a pharmacy's relationships with third-party payors. Changes in the third-party payor industry evolve constantly and, we suggest, will continue to do so. Compounding pharmacists must be aware of those changes to help ensure success in a highly competitive marketplace. To our knowledge at the time of this writing, there is no certification program for compounding pharmacists, although pharmacy technicians can achieve certification and may be required to do so by the state in which they practice (a topic beyond the scope of this article). For that reason, we primarily address accreditation and credentialing for 503A compounding pharmacies. In this article, the evolution of the third-party payment system for compounds is reviewed; the definitions of certification, accreditation, and credentialing are examined; and the benefits and recognition of obtaining accredited or credentialed status are discussed. Suggestions for selecting an appropriate agency that offers accreditation or credentialing, preparing for and undergoing an onsite survey, responding to findings, and maintaining a pharmacy practice that enables a successful survey outcome are presented. The personal experience of author CK during accreditation and credentialing is discussed, as is the role of a consultant (author BJ) in helping compounders prepare for the survey process. A list of agencies that offer accreditation and credentialing for compounding pharmacies is included for easy reference. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

Development and validation of the Stirling Eating Disorder Scales.

Science.gov (United States)

Williams, G J; Power, K G; Miller, H R; Freeman, C P; Yellowlees, A; Dowds, T; Walker, M; Parry-Jones, W L

1994-07-01

The development and reliability/validity check of an 80-item, 8-scale measure for use with eating disorder patients is presented. The Stirling Eating Disorder Scales (SEDS) assess anorexic dietary behavior, anorexic dietary cognitions, bulimic dietary behavior, bulimic dietary cognitions, high perceived external control, low assertiveness, low self-esteem, and self-directed hostility. The SEDS were administered to 82 eating disorder patients and 85 controls. Results indicate that the SEDS are acceptable in terms of internal consistency, reliability, group validity, and concurrent validity.

Prediction of enthalpy of fusion of pure compounds using an Artificial Neural Network-Group Contribution method

International Nuclear Information System (INIS)

Gharagheizi, Farhad; Salehi, Gholam Reza

2011-01-01

Highlights: → An Artificial Neural Network-Group Contribution method is presented for prediction of enthalpy of fusion of pure compounds at their normal melting point. → Validity of the model is confirmed using a large evaluated data set containing 4157 pure compounds. → The average percent error of the model is equal to 2.65% in comparison with the experimental data. - Abstract: In this work, the Artificial Neural Network-Group Contribution (ANN-GC) method is applied to estimate the enthalpy of fusion of pure chemical compounds at their normal melting point. 4157 pure compounds from various chemical families are investigated to propose a comprehensive and predictive model. The obtained results show the Squared Correlation Coefficient (R 2 ) of 0.999, Root Mean Square Error of 0.82 kJ/mol, and average absolute deviation lower than 2.65% for the estimated properties from existing experimental values.

Identification of Organic Iodine Compounds and Their Transformation Products in Edible Iodized Salt Using Liquid Chromatography-High Resolution Mass Spectrometry.

Science.gov (United States)

Yun, Lifen; Peng, Yue'e; Chang, Qing; Zhu, Qingxin; Guo, Wei; Wang, Yanxin

2017-07-05

The consumption of edible iodized salt is a key strategy to control and eliminate iodine deficiency disorders worldwide. We herein report the identification of the organic iodine compounds present in different edible iodized salt products using liquid chromatography combined with high resolution mass spectrometry. A total of 38 organic iodine compounds and their transformation products (TPs) were identified in seaweed iodine salt from China. Our experiments confirmed that the TPs were generated by the replacement of I atoms from organic iodine compounds with Cl atoms. Furthermore, the organic iodine compound contents in 4 seaweed iodine salt samples obtained from different manufacturers were measured, with significant differences in content being observed. We expect that the identification of organic iodine compounds in salt will be important for estimating the validity and safety of edible iodized salt products.

TBC2health: a database of experimentally validated health-beneficial effects of tea bioactive compounds.

Science.gov (United States)

Zhang, Shihua; Xuan, Hongdong; Zhang, Liang; Fu, Sicong; Wang, Yijun; Yang, Hua; Tai, Yuling; Song, Youhong; Zhang, Jinsong; Ho, Chi-Tang; Li, Shaowen; Wan, Xiaochun

2017-09-01

Tea is one of the most consumed beverages in the world. Considerable studies show the exceptional health benefits (e.g. antioxidation, cancer prevention) of tea owing to its various bioactive components. However, data from these extensively published papers had not been made available in a central database. To lay a foundation in improving the understanding of healthy tea functions, we established a TBC2health database that currently documents 1338 relationships between 497 tea bioactive compounds and 206 diseases (or phenotypes) manually culled from over 300 published articles. Each entry in TBC2health contains comprehensive information about a bioactive relationship that can be accessed in three aspects: (i) compound information, (ii) disease (or phenotype) information and (iii) evidence and reference. Using the curated bioactive relationships, a bipartite network was reconstructed and the corresponding network (or sub-network) visualization and topological analyses are provided for users. This database has a user-friendly interface for entry browse, search and download. In addition, TBC2health provides a submission page and several useful tools (e.g. BLAST, molecular docking) to facilitate use of the database. Consequently, TBC2health can serve as a valuable bioinformatics platform for the exploration of beneficial effects of tea on human health. TBC2health is freely available at http://camellia.ahau.edu.cn/TBC2health. © The Author 2016. Published by Oxford University Press.

Analysis of lomustine drug content in FDA-approved and compounded lomustine capsules.

Science.gov (United States)

KuKanich, Butch; Warner, Matt; Hahn, Kevin

2017-02-01

OBJECTIVE To determine the lomustine content (potency) in compounded and FDA-approved lomustine capsules. DESIGN Evaluation study. SAMPLE 2 formulations of lomustine capsules (low dose [7 to 11 mg] and high dose [40 to 48 mg]; 5 capsules/dose/source) from 3 compounders and from 1 manufacturer of FDA-approved capsules. PROCEDURES Lomustine content was measured by use of a validated high-pressure liquid chromatography method. An a priori acceptable range of 90% to 110% of the stated lomustine content was selected on the basis of US Pharmacopeia guidelines. RESULTS The measured amount of lomustine in all compounded capsules was less than the stated content (range, 59% to 95%) and was frequently outside the acceptable range (failure rate, 2/5 to 5/5). Coefficients of variation for lomustine content ranged from 4.1% to 16.7% for compounded low-dose capsules and from 1.1% to 10.8% for compounded high-dose capsules. The measured amount of lomustine in all FDA-approved capsules was slightly above the stated content (range, 104% to 110%) and consistently within the acceptable range. Coefficients of variation for lomustine content were 0.5% for low-dose and 2.3% for high-dose FDA-approved capsules. CONCLUSIONS AND CLINICAL RELEVANCE Compounded lomustine frequently did not contain the stated content of active drug and had a wider range of lomustine content variability than did the FDA-approved product. The sample size was small, and larger studies are needed to confirm these findings; however, we recommend that compounded veterinary formulations of lomustine not be used when appropriate doses can be achieved with FDA-approved capsules or combinations of FDA-approved capsules.

Constraints on Stress Components at the Internal Singular Point of an Elastic Compound Structure

Science.gov (United States)

Pestrenin, V. M.; Pestrenina, I. V.

2017-03-01

The classical analytical and numerical methods for investigating the stress-strain state (SSS) in the vicinity of a singular point consider the point as a mathematical one (having no linear dimensions). The reliability of the solution obtained by such methods is valid only outside a small vicinity of the singular point, because the macroscopic equations become incorrect and microscopic ones have to be used to describe the SSS in this vicinity. Also, it is impossible to set constraint or to formulate solutions in stress-strain terms for a mathematical point. These problems do not arise if the singular point is identified with the representative volume of material of the structure studied. In authors' opinion, this approach is consistent with the postulates of continuum mechanics. In this case, the formulation of constraints at a singular point and their investigation becomes an independent problem of mechanics for bodies with singularities. This method was used to explore constraints at an internal singular point (representative volume) of a compound wedge and a compound rib. It is shown that, in addition to the constraints given in the classical approach, there are also constraints depending on the macroscopic parameters of constituent materials. These constraints turn the problems of deformable bodies with an internal singular point into nonclassical ones. Combinations of material parameters determine the number of additional constraints and the critical stress state at the singular point. Results of this research can be used in the mechanics of composite materials and fracture mechanics and in studying stress concentrations in composite structural elements.

A new wire fabrication processing using high Ga content Cu-Ga compound in V3Ga compound superconducting wire

International Nuclear Information System (INIS)

Hishinuma, Yoshimitsu; Nishimura, Arata; Kikuchi, Akihiro; Iijima, Yasuo; Takeuchi, Takao

2007-01-01

A superconducting magnet system is also one of the important components in an advanced magnetic confinement fusion reactor. Then it is required to have a higher magnetic field property to confine and maintain steady-sate burning deuterium (D)-tritium (T) fusion plasma in the large interspace during the long term operation. Burning plasma is sure to generate 14 MeV fusion neutrons during deuterium-tritium reaction, and fusion neutrons will be streamed and penetrated to superconducting magnet through large ports with damping neutron energy. Therefore, it is necessary to consider carefully not only superconducting property but also neutron irradiation property in superconducting materials for use in a future fusion reactor, and a 'low activation and high field superconducting magnet' will be required to realize the fusion power plant beyond International Thermonuclear Experimental Reactor (ITER). V-based superconducting material has a much shorter decay time of induced radioactivity compared with the Nb-based materials. We thought that the V 3 Ga compound was one of the most promising materials for the 'low activation and higher field superconductors' for an advanced fusion reactor. However, the present critical current density (J c ) property of V 3 Ga compound wire is insufficient for apply to fusion magnet applications. We investigated a new route PIT process using a high Ga content Cu-Ga compound in order to improve the superconducting property of the V 3 Ga compound wire. (author)

Validation of a Supplemental Reading Intervention for First-Grade Children

OpenAIRE

Case, Lisa Pericola; Speece, Deborah L.; Silverman, Rebecca; Ritchey, Kristen D.; Schatschneider, Christopher; Cooper, David H.; Montanaro, Elizabeth; Jacobs, Dawn

2010-01-01

This experimental study was designed to validate a short-term supplemental reading intervention for at-risk first-grade children. Although substantial research on long-term supplemental reading interventions exists, less is known about short-term interventions. Thirty first-grade children were randomly assigned to intervention or control conditions. Students in the intervention received 16 hours of instruction. Analyses of pre- and posttest data and growth measures suggest that short-term sup...

Model validation: a systemic and systematic approach

International Nuclear Information System (INIS)

Sheng, G.; Elzas, M.S.; Cronhjort, B.T.

1993-01-01

The term 'validation' is used ubiquitously in association with the modelling activities of numerous disciplines including social, political natural, physical sciences, and engineering. There is however, a wide range of definitions which give rise to very different interpretations of what activities the process involves. Analyses of results from the present large international effort in modelling radioactive waste disposal systems illustrate the urgent need to develop a common approach to model validation. Some possible explanations are offered to account for the present state of affairs. The methodology developed treats model validation and code verification in a systematic fashion. In fact, this approach may be regarded as a comprehensive framework to assess the adequacy of any simulation study. (author)

Simultaneous Determination of Florfenicol and Diclazuril in Compound Powder by RP-HPLC-UV Method

Directory of Open Access Journals (Sweden)

Leilei Guo

2014-01-01

Full Text Available A RP-HPLC-UV method was developed and validated for simultaneous determination of florfenicol and diclazuril in compound powder. The separation involved using a SinoChoom ODS-BP C18 (5 μm, 4.6 mm × 250 mm analytical column. The mobile phase was a mixture of acetonitrile-0.2% phosphoric acid (pH was adjusted to 3.0 with triethylamine. The ratio of acetonitrile and 0.2% phosphoric acid in the mobile phase was 60 : 40 (v/v from 0 minutes to 6 minutes and 70 : 30 (v/v from 6.1 minutes to 15 minutes. The flow rate was 1 mL/min. The temperature of the analytical column was maintained at 30°C. The detection was monitored at 225 nm and 277 nm for florfenicol and diclazuril, respectively. The excipients in the compound powder did not interfere with the drug peaks. The calibration curves of florfenicol and diclazuril were fairly linear over the concentration ranges between 50.0–500.0 μg/mL (r=0.9995 and 10.0–100.0 μg/mL (r=0.9992, respectively. The RSD of both the intraday and interday variations was below 2.1% for florfenicol and diclazuril. The method was successfully validated according to International Conference on Harmonisation and proved to be suitable for the simultaneous determination of florfenicol and diclazuril in compound powder.

Characterization of phenolic compounds and antinociceptive activity of Sempervivum tectorum L. leaf juice.

Science.gov (United States)

Alberti, Ágnes; Béni, Szabolcs; Lackó, Erzsébet; Riba, Pál; Al-Khrasani, Mahmoud; Kéry, Ágnes

2012-11-01

Sempervivum tectorum L. (houseleek) leaf juice has been known as a traditional herbal remedy. The aim of the present study was the chemical characterization of its phenolic compounds and to develop quantitation methods for its main flavonol glycoside, as well as to evaluate its antinociceptive activity. Lyophilized houseleek leaf juice was studied by HPLC-DAD coupled to electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) to identify flavonol glycosides, hydroxy-benzoic and hydroxy-cinnamic acids. Ten flavonol glycosides and sixteen phenolic acid compounds were identified or tentatively characterized. Structure of the main flavonol compound was identified by nuclear magnetic resonance spectroscopy. Three characteristic kaempferol glycosides were isolated and determined by LC-ESI-MS/MS with external calibration method, using the isolated compounds as standard. The main flavonol glycoside was also determined by HPLC-DAD. Validated HPLC-DAD and LC-ESI-MS/MS methods were developed to quantify kaempferol-3-O-rhamnosyl-glucoside-7-O-rhamnoside and two other kaempferol glycosides. Antinociceptive activity of houseleek leaf juice was investigated by writhing test of mice. Sempervivum extract significantly reduced pain in the mouse writhing test. Copyright © 2012 Elsevier B.V. All rights reserved.

Student nurses' perceptions of mental health care: Validation of a questionnaire

NARCIS (Netherlands)

Corine Latour; Hanneke Hoekstra; Alex van der Heijden; prof Berno van Meijel; Jaap van der Bijl

2011-01-01

This article describes the results of a study into the psychometric properties of a questionnaire about student nurses' perceptions of mental health care. The questionnaire was constructed in 2008, but has not yet been tested in terms of construct validity and reliability. A validated questionnaire

Simple Method of Preparation and Characterization of New Antifungal Active Biginelli Type Heterocyclic Compounds

Science.gov (United States)

Velan, A. Senthilkumara; Joseph, J.; Raman, N.

2008-01-01

A simple, efficient and cost effective method is described for the synthesis of Biginelli type heterocyclic compounds of dihydropyrimidinones analogous. They were prepared from a reaction mixture consisting of substituted benzaldehydes, thiourea and ethylacetoacetate using ammonium dihydrogenphosphate as catalyst. The procedure for the preparation of the compounds is environmentally benign and safe which is advantageous in terms of experimentation, catalyst reusability, yields of the products, shorter reaction times and preclusion of toxic solvents. The four new synthesised compounds were tested for their antifungal activity. They have good antifungal activity comparing to the standard (Fluconazole). PMID:23997611

Direct dating of archaeological pottery by compound-specific 14C analysis of preserved lipids.

Science.gov (United States)

Stott, Andrew W; Berstan, Robert; Evershed, Richard P; Bronk-Ramsey, Christopher; Hedges, Robert E M; Humm, Martin J

2003-10-01

A methodology is described demonstrating the utility of the compound-specific 14C technique as a direct means of dating archaeological pottery. The method uses automated preparative capillary gas chromatography employing wide-bore capillary columns to isolate individual compounds from lipid extracts of archaeological potsherds in high purity (>95%) and amounts (>200 microg) sufficient for radiocarbon dating using accelerator mass spectrometry (AMS). A protocol was developed and tested on n-alkanes and n-carboxylic acids possessing a broad range of 14C ages. Analytical blanks and controls allowed background 14C measurements to be assessed and potential sources of errors to be detected, i.e., contamination with modern or dead 14C, isotopic fraction effects, etc. A "Russian doll" method was developed to transfer isolated target compounds onto tin powder/capsules prior to combustion and AMS analyses. The major advantage of the compound-specific technique is that 14C dates obtained for individual compounds can be directly linked to the commodities processed in the vessels during their use, e.g., animal fats. The compound-specific 14C dating protocol was validated on a suite of ancient pottery whose predicted ages spanned a 5000-year date range. Initial results indicate that meaningful correlations can be obtained between the predicted date of pottery and that of the preserved lipids. These findings constitute an important step forward to the direct dating of archaeological pottery.

Normative data for Chinese compound remote associate problems.

Science.gov (United States)

Wu, Ching-Lin; Chen, Hsueh-Chih

2017-12-01

The Remote Associates Test (RAT) is a well-known measure of creativity, with each item on the RAT is composed of three unrelated stimulus words. The participant's task is to find an answer in the form of a word that could combine with each of the stimulus words, thus forming three new actual nouns. Researchers have modified the RAT to develop compound remote associate problems that emphasize combining vocabulary to form compound words. In the field of creativity research for Mandarin speakers, the Chinese RAT has been widely applied for over 10 years. The original RAT, compound remote associate problems, and Chinese RAT have various common advantages, such as being convenient to use and having objective scoring; additionally, the development of items for certain tests is easy and satisfies the requirements of psychological assessments in terms of the quantity of items. Currently, many language editions of the RAT and compound remote associate problems already exist. In particular, the English and Italian versions of these tests already have derived normative data. Because approximately 20% of the world's population are native Mandarin speakers, and because increasing numbers of people are choosing Mandarin as a second language, the need to increase Mandarin-language resources is growing; however, normative data for the Chinese RAT still do not exist. To address this issue, in the present study we developed Chinese compound remote associate problems and analyzed the passing rates by items, problem solving times, and various normative data, using the responses of 253 subjects in three experiments.

Beyond dichotomies : on the nature and classification of compound verbs in English

Directory of Open Access Journals (Sweden)

Alexandra Bagasheva

2011-12-01

Full Text Available The study of compound verbs in English poses numerous problems, among which even their recognition as compounds on grounds of their derivation. Resulting from at least three different word-formation patterns, compound verbs constitute a heterogeneous class of complex lexemes. Their status as actual compound lexemes invites the differentiation between compounding as a word-formation process and compounds as a special class of lexemes. Even within the latter, compound verbs display marked properties at least in relation to the inability of standard classifications of compounds to capture and compromise their lexical uniformity and their heterogeneous origin. The adoption of a position in which it is argued that compound verbs in English constitute a constructional idiom and the application of scalar analytical notions which combine word-formationist and lexical-semantic accounts cast in the general framework of the cognitive linguistic enterprise yield informative generalizations concerning the linguistic and conceptual properties of compound verbs in English. In view of Radden and Dirven's (2007: 41-46 claim that we do not need "more than two basic types of conceptual units things and relations" in order to establish linguistically relevant conceptual distinctions, compound verbs pose a problem for neat dichotomous treatment as they very often both conceptually and in terms of form include a "thing" (e.g. to flat-hunt, to house-sit, to fellow-feel, to case-harden, etc. and thus come closer to a "situation" than to a "relation". Exactly because of the fact that compound verbs profile/perspectivize "situations" as "relations", they function as special construal mechanisms and as such do not fit the subordinate/coordinate distinction, because they name situations. In view of the above the paper treats compound verbs as a constructional idiom whose analysis necessitates the recognition of the role of conceptual conversion mechanisms, scalar

Long-Term Prognostic Validity of Talent Selections: Comparing National and Regional Coaches, Laypersons and Novices

Science.gov (United States)

Schorer, Jörg; Rienhoff, Rebecca; Fischer, Lennart; Baker, Joseph

2017-01-01

In most sports, the development of elite athletes is a long-term process of talent identification and support. Typically, talent selection systems administer a multi-faceted strategy including national coach observations and varying physical and psychological tests when deciding who is chosen for talent development. The aim of this exploratory study was to evaluate the prognostic validity of talent selections by varying groups 10 years after they had been conducted. This study used a unique, multi-phased approach. Phase 1 involved players (n = 68) in 2001 completing a battery of general and sport-specific tests of handball ‘talent’ and performance. In Phase 2, national and regional coaches (n = 7) in 2001 who attended training camps identified the most talented players. In Phase 3, current novice and advanced handball players (n = 12 in each group) selected the most talented from short videos of matches played during the talent camp. Analyses compared predictions among all groups with a best model-fit derived from the motor tests. Results revealed little difference between regional and national coaches in the prediction of future performance and little difference in forecasting performance between novices and players. The best model-fit regression by the motor-tests outperformed all predictions. While several limitations are discussed, this study is a useful starting point for future investigations considering athlete selection decisions in talent identification in sport. PMID:28744238

Long-Term Prognostic Validity of Talent Selections: Comparing National and Regional Coaches, Laypersons and Novices

Directory of Open Access Journals (Sweden)

Jörg Schorer

2017-07-01

Full Text Available In most sports, the development of elite athletes is a long-term process of talent identification and support. Typically, talent selection systems administer a multi-faceted strategy including national coach observations and varying physical and psychological tests when deciding who is chosen for talent development. The aim of this exploratory study was to evaluate the prognostic validity of talent selections by varying groups 10 years after they had been conducted. This study used a unique, multi-phased approach. Phase 1 involved players (n = 68 in 2001 completing a battery of general and sport-specific tests of handball ‘talent’ and performance. In Phase 2, national and regional coaches (n = 7 in 2001 who attended training camps identified the most talented players. In Phase 3, current novice and advanced handball players (n = 12 in each group selected the most talented from short videos of matches played during the talent camp. Analyses compared predictions among all groups with a best model-fit derived from the motor tests. Results revealed little difference between regional and national coaches in the prediction of future performance and little difference in forecasting performance between novices and players. The best model-fit regression by the motor-tests outperformed all predictions. While several limitations are discussed, this study is a useful starting point for future investigations considering athlete selection decisions in talent identification in sport.

Long-Term Prognostic Validity of Talent Selections: Comparing National and Regional Coaches, Laypersons and Novices.

Science.gov (United States)

Schorer, Jörg; Rienhoff, Rebecca; Fischer, Lennart; Baker, Joseph

2017-01-01

In most sports, the development of elite athletes is a long-term process of talent identification and support. Typically, talent selection systems administer a multi-faceted strategy including national coach observations and varying physical and psychological tests when deciding who is chosen for talent development. The aim of this exploratory study was to evaluate the prognostic validity of talent selections by varying groups 10 years after they had been conducted. This study used a unique, multi-phased approach. Phase 1 involved players ( n = 68) in 2001 completing a battery of general and sport-specific tests of handball 'talent' and performance. In Phase 2, national and regional coaches ( n = 7) in 2001 who attended training camps identified the most talented players. In Phase 3, current novice and advanced handball players ( n = 12 in each group) selected the most talented from short videos of matches played during the talent camp. Analyses compared predictions among all groups with a best model-fit derived from the motor tests. Results revealed little difference between regional and national coaches in the prediction of future performance and little difference in forecasting performance between novices and players. The best model-fit regression by the motor-tests outperformed all predictions. While several limitations are discussed, this study is a useful starting point for future investigations considering athlete selection decisions in talent identification in sport.

Identification of Putative Precursor Genes for the Biosynthesis of Cannabinoid-Like Compound in Radula marginata

Directory of Open Access Journals (Sweden)

Tajammul Hussain

2018-05-01

Full Text Available The liverwort Radula marginata belongs to the bryophyte division of land plants and is a prospective alternate source of cannabinoid-like compounds. However, mechanistic insights into the molecular pathways directing the synthesis of these cannabinoid-like compounds have been hindered due to the lack of genetic information. This prompted us to do deep sequencing, de novo assembly and annotation of R. marginata transcriptome, which resulted in the identification and validation of the genes for cannabinoid biosynthetic pathway. In total, we have identified 11,421 putative genes encoding 1,554 enzymes from 145 biosynthetic pathways. Interestingly, we have identified all the upstream genes of the central precursor of cannabinoid biosynthesis, cannabigerolic acid (CBGA, including its two first intermediates, stilbene acid (SA and geranyl diphosphate (GPP. Expression of all these genes was validated using quantitative real-time PCR. We have characterized the protein structure of stilbene synthase (STS, which is considered as a homolog of olivetolic acid in R. marginata. Moreover, the metabolomics approach enabled us to identify CBGA-analogous compounds using electrospray ionization mass spectrometry (ESI-MS/MS and gas chromatography mass spectrometry (GC-MS. Transcriptomic analysis revealed 1085 transcription factors (TF from 39 families. Comparative analysis showed that six TF families have been uniquely predicted in R. marginata. In addition, the bioinformatics analysis predicted a large number of simple sequence repeats (SSRs and non-coding RNAs (ncRNAs. Our results collectively provide mechanistic insights into the putative precursor genes for the biosynthesis of cannabinoid-like compounds and a novel transcriptomic resource for R. marginata. The large-scale transcriptomic resource generated in this study would further serve as a reference transcriptome to explore the Radulaceae family.

Statistical emission of complex fragments from highly excited compound nucleus

International Nuclear Information System (INIS)

Matsuse, T.

1991-01-01

A full statistical analysis has been given in terms of the Extended Hauser-Feshbach method. The charge and kinetic energy distributions of 35 Cl+ 12 C reaction at E lab = 180, 200 MeV and 23 Na+ 24 Mg reaction at E lab = 89 MeV which form the 47 V compound nucleus are investigated as a prototype of the light mass system. The measured kinetic energy distributions of the complex fragments are shown to be well reproduced by the Extended Hauser-Feshbach method, so the observed complex fragment production is understood as the statistical binary decay from the compound nucleus induced by heavy-ion reaction. Next, this method is applied to the study of the complex production from the 111 In compound nucleus which is formed by the 84 Kr+ 27 Al reaction at E lab = 890 MeV. (K.A.) 18 refs., 10 figs

Prioritizing pesticide compounds for analytical methods development

Science.gov (United States)

Norman, Julia E.; Kuivila, Kathryn; Nowell, Lisa H.

2012-01-01

The U.S. Geological Survey (USGS) has a periodic need to re-evaluate pesticide compounds in terms of priorities for inclusion in monitoring and studies and, thus, must also assess the current analytical capabilities for pesticide detection. To meet this need, a strategy has been developed to prioritize pesticides and degradates for analytical methods development. Screening procedures were developed to separately prioritize pesticide compounds in water and sediment. The procedures evaluate pesticide compounds in existing USGS analytical methods for water and sediment and compounds for which recent agricultural-use information was available. Measured occurrence (detection frequency and concentrations) in water and sediment, predicted concentrations in water and predicted likelihood of occurrence in sediment, potential toxicity to aquatic life or humans, and priorities of other agencies or organizations, regulatory or otherwise, were considered. Several existing strategies for prioritizing chemicals for various purposes were reviewed, including those that identify and prioritize persistent, bioaccumulative, and toxic compounds, and those that determine candidates for future regulation of drinking-water contaminants. The systematic procedures developed and used in this study rely on concepts common to many previously established strategies. The evaluation of pesticide compounds resulted in the classification of compounds into three groups: Tier 1 for high priority compounds, Tier 2 for moderate priority compounds, and Tier 3 for low priority compounds. For water, a total of 247 pesticide compounds were classified as Tier 1 and, thus, are high priority for inclusion in analytical methods for monitoring and studies. Of these, about three-quarters are included in some USGS analytical method; however, many of these compounds are included on research methods that are expensive and for which there are few data on environmental samples. The remaining quarter of Tier 1

Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio

International Nuclear Information System (INIS)

Keck, B.D.; Ognibene, T.; Vogel, J.S.

2010-01-01

Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of 14 C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of 14 C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the 14 C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with 14 C corresponds to 30 fg equivalents. AMS

Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio.

Energy Technology Data Exchange (ETDEWEB)

Keck, B D; Ognibene, T; Vogel, J S

2010-02-05

Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of {sup 14}C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of {sup 14}C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the {sup 14}C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with {sup 14}C corresponds to 30 fg

Method validation and verification in liquid scintillation counting using the long-term uncertainty method (LTUM) on two decades of proficiency test data

International Nuclear Information System (INIS)

Verrezen, F.; Vasile, M.; Loots, H.; Bruggeman, M.

2017-01-01

Results from proficiency tests gathered over the past two decades by the laboratory for low level radioactivity measurements for liquid scintillation counting of 3 H (184 results) and 14 C (74 results) are used to verify the validated measurement methods used by the laboratory, in particular the estimated uncertainty budget of the method and its reproducibility and stability. A linear regression approach is used for the analysis of the results, described in the literature as the long term uncertainty in measurement method. The present study clearly indicates the advantages of using proficiency test results in identifying possible constant or proportional bias effects as well as the possibility to compare the laboratory performance with the performance of peer laboratories. (author)

Quantitative determination of solid-state forms of a pharmaceutical development compound in drug substance and tablets.

Science.gov (United States)

Xie, Yong; Tao, Wenle; Morrison, Henry; Chiu, Rick; Jona, Janan; Fang, Jan; Cauchon, Nina

2008-10-01

Common analytical techniques including Raman, NIR, and XRD were evaluated for quantitative determination of three solid-state forms (amorphous, Form B and Form C) of a development compound. Raman spectroscopy was selected as the primary analytical technique with sufficient sensitivity to monitor and quantify the neat drug substance alone and in the drug product. A reliable multivariate curve resolution (MCR) method based on the second derivative Raman measurements of the three pure physical forms was developed and validated with 3.5% root mean square error of prediction (RMSEP) for Form B, which was selected as the preferred form for further development. A partial least squares (PLS) algorithm was also used for the multivariate calibration of both the NIR and Raman measurements. The long-term stability of Form B as a neat active pharmaceutical ingredient (API) and in a tablet formulation was quantitatively monitored under various stress conditions of temperature and moisture. Moisture, temperature, excipients and compression were found to have significant effects on the phase transition behavior of Form B.

New device for time-averaged measurement of volatile organic compounds (VOCs).

Science.gov (United States)

Santiago Sánchez, Noemí; Tejada Alarcón, Sergio; Tortajada Santonja, Rafael; Llorca-Pórcel, Julio

2014-07-01

through a glass cell containing adsorbent material where the VOCs are retained. The adsorbent used, made in LABAQUA, is a mixture of alginic acid and activated carbon. Due to its high permeability it allows the passage and retention of THMs in a suitable way, thus solving many of the problems of other common adsorbents. Also, to avoid degradation of the adsorbent, it is wrapped in a low density polyethylene (LDPE) membrane. After a sampling period of between 1 and 14 days, the adsorbent is collected and analyzed in the laboratory to quantify the VOC average concentration. This device resolves some of the limitations of the classical sampling system (spot samples), since we will take into account the fluctuations in the concentration of VOCs by averaging the same over time. This study presents the results obtained by the device for quantifying the VOCs legislated in the Directive 2000/60/EC. We present the validation of linearity over time and the limits of quantification, as well as the results of sample rate (Rs) obtained for each compound. The results demonstrate the high robustness and high sensitivity of the device. In addition the system has been validated in real waste water samples, comparing the results obtained with this device with the values of classical spot sampling, obtaining excellent results. Copyright © 2013 Elsevier B.V. All rights reserved.

Identification and Validation of a Potent Dual Inhibitor of the P. falciparum M1 and M17 Aminopeptidases Using Virtual Screening.

Directory of Open Access Journals (Sweden)

Chiara Ruggeri

Full Text Available The Plasmodium falciparum PfA-M1 and PfA-M17 metalloaminopeptidases are validated drug targets for the discovery of antimalarial agents. In order to identify dual inhibitors of both proteins, we developed a hierarchical virtual screening approach, followed by in vitro evaluation of the highest scoring hits. Starting from the ZINC database of purchasable compounds, sequential 3D-pharmacophore and molecular docking steps were applied to filter the virtual 'hits'. At the end of virtual screening, 12 compounds were chosen and tested against the in vitro aminopeptidase activity of both PfA-M1 and PfA-M17. Two molecules showed significant inhibitory activity (low micromolar/nanomolar range against both proteins. Finally, the crystal structure of the most potent compound in complex with both PfA-M1 and PfA-M17 was solved, revealing the binding mode and validating our computational approach.

Wick calculus on spaces of generalized functions of compound poisson white noise

Science.gov (United States)

Lytvynov, Eugene W.; Rebenko, Alexei L.; Shchepan'ur, Gennadi V.

1997-04-01

We derive white noise calculus for a compound Poisson process. Namely, we consider, on the Schwartz space of tempered distributions, S', a measure of compound Poisson white noise, μcp, and construct a whole scale of standard nuclear triples ( Scp) - x ⊃ L2cp) ≡ L2( S', dμcp) ⊃( Scpx, x≥ 0, which are obtained as images under some isomorphism of the corresponding triples centred at a Fock space. It turns out that the most interesting case is x = 1, when our triple coincides with the triple that is constructed by using a system of Appell polynomials in the framework of non-Gaussian biorthogonal analysis. Our special attention is paid to the Wick calculus of the Poisson field, or the quantum compound Poisson white noise process in other terms, which is the family of operators acting from ( Scp) 1 into ( Scp) 1 as multiplication by the compound Poisson white noise ω( t).

Development and validation of a portable gas phase standard generation and calibration system for volatile organic compounds

Science.gov (United States)

P. Veres; J. B. Gilman; J. M. Roberts; W. C. Kuster; C. Warneke; I. R. Burling; J. de Gouw

2010-01-01

We report on the development of an accurate, portable, dynamic calibration system for volatile organic compounds (VOCs). The Mobile Organic Carbon Calibration System (MOCCS) combines the production of gas-phase VOC standards using permeation or diffusion sources with quantitative total organic carbon (TOC) conversion on a palladium surface to CO2 in the presence of...

Calibration, validation, and sensitivity analysis: What's what

International Nuclear Information System (INIS)

Trucano, T.G.; Swiler, L.P.; Igusa, T.; Oberkampf, W.L.; Pilch, M.

2006-01-01

One very simple interpretation of calibration is to adjust a set of parameters associated with a computational science and engineering code so that the model agreement is maximized with respect to a set of experimental data. One very simple interpretation of validation is to quantify our belief in the predictive capability of a computational code through comparison with a set of experimental data. Uncertainty in both the data and the code are important and must be mathematically understood to correctly perform both calibration and validation. Sensitivity analysis, being an important methodology in uncertainty analysis, is thus important to both calibration and validation. In this paper, we intend to clarify the language just used and express some opinions on the associated issues. We will endeavor to identify some technical challenges that must be resolved for successful validation of a predictive modeling capability. One of these challenges is a formal description of a 'model discrepancy' term. Another challenge revolves around the general adaptation of abstract learning theory as a formalism that potentially encompasses both calibration and validation in the face of model uncertainty

Quantitative and pattern recognition analysis of five marker compounds in Raphani semen using high-performance liquid chromatography

International Nuclear Information System (INIS)

Jung, Yeon Woo; Lee, Joo Sang; Zhao, Bing Tian; Woo, Mi Hee; Min, Byung Sun; Kim, Jeong Ah; Eun, Rhan Woo

2015-01-01

A rapid and simple high-performance liquid chromatography (HPLC)-photodiode array (PDA) analytical method was developed for the quantitative analysis of Raphani Semen (RS). This method was successfully used to determine the five main phenolic compounds found in RS specimens from different production regions. The compounds included sinapine thiocyanate (1), β-d-fructofuranosyl-α-d-(6-O-sinapoyl)-glucopyranoside (2), isorhamnetin 3,4′-di-O-β-d-glucoside (3), β-d-(3-O-sinapoyl)-fructofuranosyl-α-d-(6-O-sinapoyl)-glucopyranoside (4), and β-d-(3,4-O-disinapoyl)-fructofuranosyl-α-d-(6-O-sinapoyl)-glucopyranoside (5). The marker compounds were separated using an Agilent Eclipse XDB-C18 column (5.0 µm, 150 × 4.6 mm i.d.) by gradient elution with acetonitrile/water/0.1% trifluoroacetic acid (TFA) as the mobile phase (flow rate, 1.0 mL/min). This method was fully validated with respect to linearity, precision, accuracy, stability, and robustness. The HPLC analytical method was validated to conduct a pattern recognition analysis by repeatedly analyzing 56 seed samples including 55 RS (C01–C49 and K50–K55) and 1 Brassicae Semen samples. In addition, a content standard for RS was proposed. Compounds 1 and 4 were revealed as major components in the HPLC chromatogram, and their contents ranged from 0.06 to 0.20 and 0.02 to 0.35 mg/g, respectively. These results demonstrate the successful development of an analytical method suitable for evaluating the quality and distinguishing the origin of RS. In addition, we briefly describe the crucial liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical conditions for the precise simultaneous quantification of the marker compounds

Quantitative and pattern recognition analysis of five marker compounds in Raphani semen using high-performance liquid chromatography

Energy Technology Data Exchange (ETDEWEB)

Jung, Yeon Woo; Lee, Joo Sang; Zhao, Bing Tian; Woo, Mi Hee; Min, Byung Sun [College of Pharmacy, Drug Research and Development Center, Catholic University of Daegu, Gyeongsan (Korea, Republic of); Kim, Jeong Ah [College of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu (Korea, Republic of); Eun, Rhan Woo [College of Pharmacy, Chosun University, Gwangju (Korea, Republic of)

2015-09-15

A rapid and simple high-performance liquid chromatography (HPLC)-photodiode array (PDA) analytical method was developed for the quantitative analysis of Raphani Semen (RS). This method was successfully used to determine the five main phenolic compounds found in RS specimens from different production regions. The compounds included sinapine thiocyanate (1), β-d-fructofuranosyl-α-d-(6-O-sinapoyl)-glucopyranoside (2), isorhamnetin 3,4′-di-O-β-d-glucoside (3), β-d-(3-O-sinapoyl)-fructofuranosyl-α-d-(6-O-sinapoyl)-glucopyranoside (4), and β-d-(3,4-O-disinapoyl)-fructofuranosyl-α-d-(6-O-sinapoyl)-glucopyranoside (5). The marker compounds were separated using an Agilent Eclipse XDB-C18 column (5.0 µm, 150 × 4.6 mm i.d.) by gradient elution with acetonitrile/water/0.1% trifluoroacetic acid (TFA) as the mobile phase (flow rate, 1.0 mL/min). This method was fully validated with respect to linearity, precision, accuracy, stability, and robustness. The HPLC analytical method was validated to conduct a pattern recognition analysis by repeatedly analyzing 56 seed samples including 55 RS (C01–C49 and K50–K55) and 1 Brassicae Semen samples. In addition, a content standard for RS was proposed. Compounds 1 and 4 were revealed as major components in the HPLC chromatogram, and their contents ranged from 0.06 to 0.20 and 0.02 to 0.35 mg/g, respectively. These results demonstrate the successful development of an analytical method suitable for evaluating the quality and distinguishing the origin of RS. In addition, we briefly describe the crucial liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical conditions for the precise simultaneous quantification of the marker compounds.

Fabrication and electrical characterization of Al/diazo compound containing polyoxy chain/p-Si device structure

Science.gov (United States)

Birel, Ozgul; Kavasoglu, Nese; Kavasoglu, A. Sertap; Dincalp, Haluk; Metin, Bengul

2013-03-01

Diazo-compounds are important class of chemical compounds in terms of optical and electronic properties which make them potentially attractive for device applications. Diazo compound containing polyoxy chain has been deposited on p-Si. Current-voltage characteristics of Al/diazo compound containing polyoxy chain/p-Si structure present rectifying behaviour. The Schottky barrier height (SBH), diode factor (n), reverse saturation current (Io), interface state density (Nss) of Al/diazo compound containing polyoxy chain/p-Si structure have been calculated from experimental forward bias current-voltage data measured in the temperature range 100-320 K and capacitance-voltage data measured at room temperature and 1 MHz. The calculated values of SBH have ranged from 0.041 and 0.151 eV for the high and low temperature regions. Diode factor values fluctuate between the values 14 and 18 with temperature. Such a high diode factors stem from disordered interface layer in a junction structure as stated by Brötzmann et al. [M. Brötzmann, U. Vetter, H. Hofsäss, J. Appl. Phys. 106 (2009) 063704]. The calculated values of saturation current have ranged from 3×10-11 A to 2.79×10-7 A and interface state density have ranged from 5×1011 eV-1 cm-2 and 4×1013 eV-1 cm-2 as temperature increases. Results show that Al/diazo compound containing polyoxy chain/p-Si structure is a valuable candidate for device applications in terms of low reverse saturation current and low interface state density.

Placental transfer of iodine and iodine compounds

International Nuclear Information System (INIS)

Stieve, F.E.; Zemlin, G.; Griessl, I.

1985-11-01

The following topics are valid for man and mammalians with haemochorial placenta, which are examined up to now: Within several hours after injection of radioactive inorganic iodide-compounds activity can be realized in the fetus. The transfer occurs bidirectionally through the placenta. The concentration of radioactive iodide in the fetal serum exceeds that of the maternal one already a short time after application. Radioactive iodide accumulates in the fetus before its thyroid starts its function and is mainly concentrated in liver and intestine; after starting its function, the fetal thyroid, stores the radioactive iodide at a very high percent rate. During gestation the concentration of radioactive iodide in the fetal thyroid increases and at the end of gestation it can exceed by 3-10 fold that in the maternal thyroid. Single uptake of radioactive iodide leads to a higher activity than chronic uptake. No analogy can be found in the concentration of fetal and maternal radioactive thyroid hormon compounds. A placental permeability for T 4 and T 3 only exists to a very small extent. Resulting from radioactive iodide transfer examinations, good accordance can be found between the individual animal species and man, while data on the passage of radioactive thyroid hormones vary to a small extent between the animal species. (orig./MG) [de

Exposure to organic compounds during heat treatment of cooking oils

Directory of Open Access Journals (Sweden)

Marzena Zaciera

2012-09-01

Full Text Available Fumes from cooking oils were found to be genotoxic in several short-term tests. Epidemiological research among Taiwanese and Chinese women has shown high incidence of lung cancer. These women were not smoking or rarely smoking , but they cooked meals every day. A lot of organic compounds have been identified from cooking oils including PAH.

New procedure for the control of the treatment of industrial effluents to remove volatile organosulfur compounds.

Science.gov (United States)

Boczkaj, Grzegorz; Makoś, Patrycja; Fernandes, André; Przyjazny, Andrzej

2016-10-01

We present a new procedure for the determination of volatile organosulfur compounds in samples of industrial effluents using dispersive liquid-liquid microextraction and gas chromatography with flame photometric detection. Initially, the extraction parameters were optimized. These included: type and volume of extraction solvent, volume of disperser solvent, salting out effect, pH, time and speed of centrifugation as well as extraction time. The procedure was validated for 30 compounds. The developed procedure has low detection limits of 0.0071-0.49 μg/L and a good precision (relative standard deviation values of 1.2-5.0 and 0.6-4.1% at concentrations of 1 and 10 μg/L, respectively). The procedure was used to determine the content of volatile organosulfur compounds in samples of effluents from the production of bitumens before and after chemical treatment, in which six compounds were identified, including 2-mercaptoethanol, thiophenol, thioanisole, dipropyl disulfide, 1-decanethiol, and phenyl isothiocyanate at concentrations ranging from 0.47 to 8.89 μg/L. Problems in the determination of organosulfur compounds related to considerable changes in composition of the effluents, increase in concentration of individual compounds and appearance of secondary pollutants during effluent treatment processes are also discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simultaneous Determination of 14 Phenolic Compounds in Grape Canes by HPLC-DAD-UV Using Wavelength Switching Detection

Directory of Open Access Journals (Sweden)

Ang Zhang

2013-11-01

Full Text Available The paper described a novel chromatographic method for the simultaneous determination of phenolic compounds such as gallic, protocatechuic, vanillic, caffeic, syringic, p-coumaric and salicylic acid, (+-catechin, (‒-epicatechin, rutin, morin, quercetin, coumarin and trans-resveratrol at their maximum absorbance wavelengths (MAW employing reverse-phase high performance liquid chromatography combined with DAD and UV detection via detection wavelength switching. The method was based on MAW acquisition by DAD and quantification by UV. The separation process was performed on a Shim-Pack VP-ODS C18 column (250 mm × 4.6 mm, 5 μm held at 30 °C, utilizing 3.0% acetic acid and acetonitrile as mobile phase at a flow rate of 0.8 mL/min in the gradient elution mode. The method was fully validated in terms of linearity (r2 > 0.9990, 10‒350 mg/L, precision (both intra-day and inter-day RSD < 4.22%, accuracy (97.31%‒104.66%, specificity, robustness (0.59% < RSD < 2.86%, limit of detection and quantification. The switching method significantly improved the sensitivities of most phenolics studied in comparison with the standard constant wavelength detection (280 nm. The proposed method has been successfully applied to the determination of 14 phenolic compounds in 89 varieties of one-year-old Chinese grape one-year-canes. Grape canes contain many phenolics, especially trans-resveratrol, (‒-epicatechin, and (+-catechin.

Validating carbonation parameters of alkaline solid wastes via integrated thermal analyses: Principles and applications

International Nuclear Information System (INIS)

Pan, Shu-Yuan; Chang, E.-E.; Kim, Hyunook; Chen, Yi-Hung; Chiang, Pen-Chi

2016-01-01

Highlights: • Key carbonation parameters of wastes are determined by integrated thermal analyses. • A modified TG-DTG interpretation is proposed, and validated by the DSC technique. • The modified TG-DTG interpretation is further verified by DTA, TG-MS and TG-FTIR. • Kinetics and thermodynamics of CaCO 3 decomposition in solid wastes are determined. • Implication to maximum carbonation conversion of various solid wastes is described. - Abstract: Accelerated carbonation of alkaline solid wastes is an attractive method for CO 2 capture and utilization. However, the evaluation criteria of CaCO 3 content in solid wastes and the way to interpret thermal analysis profiles were found to be quite different among the literature. In this investigation, an integrated thermal analyses for determining carbonation parameters in basic oxygen furnace slag (BOFS) were proposed based on thermogravimetric (TG), derivative thermogravimetric (DTG), and differential scanning calorimetry (DSC) analyses. A modified method of TG-DTG interpretation was proposed by considering the consecutive weight loss of sample with 200–900 °C because the decomposition of various hydrated compounds caused variances in estimates by using conventional methods of TG interpretation. Different quantities of reference CaCO 3 standards, carbonated BOFS samples and synthetic CaCO 3 /BOFS mixtures were prepared for evaluating the data quality of the modified TG-DTG interpretation, in terms of precision and accuracy. The quantitative results of the modified TG-DTG method were also validated by DSC analysis. In addition, to confirm the TG-DTG results, the evolved gas analysis was performed by mass spectrometer and Fourier transform infrared spectroscopy for detection of the gaseous compounds released during heating. Furthermore, the decomposition kinetics and thermodynamics of CaCO 3 in BOFS was evaluated using Arrhenius equation and Kissinger equation. The proposed integrated thermal analyses for

Validating carbonation parameters of alkaline solid wastes via integrated thermal analyses: Principles and applications

Energy Technology Data Exchange (ETDEWEB)

Pan, Shu-Yuan [Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 10673, Taiwan (China); Chang, E.-E. [Department of Biochemistry, Taipei Medical University, Taipei 110, Taiwan (China); Kim, Hyunook [Department of Environmental Engineering, University of Seoul, Seoul 130-743 (Korea, Republic of); Chen, Yi-Hung [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 10608, Taiwan (China); Chiang, Pen-Chi, E-mail: pcchiang@ntu.edu.tw [Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 10673, Taiwan (China)

2016-04-15

Highlights: • Key carbonation parameters of wastes are determined by integrated thermal analyses. • A modified TG-DTG interpretation is proposed, and validated by the DSC technique. • The modified TG-DTG interpretation is further verified by DTA, TG-MS and TG-FTIR. • Kinetics and thermodynamics of CaCO{sub 3} decomposition in solid wastes are determined. • Implication to maximum carbonation conversion of various solid wastes is described. - Abstract: Accelerated carbonation of alkaline solid wastes is an attractive method for CO{sub 2} capture and utilization. However, the evaluation criteria of CaCO{sub 3} content in solid wastes and the way to interpret thermal analysis profiles were found to be quite different among the literature. In this investigation, an integrated thermal analyses for determining carbonation parameters in basic oxygen furnace slag (BOFS) were proposed based on thermogravimetric (TG), derivative thermogravimetric (DTG), and differential scanning calorimetry (DSC) analyses. A modified method of TG-DTG interpretation was proposed by considering the consecutive weight loss of sample with 200–900 °C because the decomposition of various hydrated compounds caused variances in estimates by using conventional methods of TG interpretation. Different quantities of reference CaCO{sub 3} standards, carbonated BOFS samples and synthetic CaCO{sub 3}/BOFS mixtures were prepared for evaluating the data quality of the modified TG-DTG interpretation, in terms of precision and accuracy. The quantitative results of the modified TG-DTG method were also validated by DSC analysis. In addition, to confirm the TG-DTG results, the evolved gas analysis was performed by mass spectrometer and Fourier transform infrared spectroscopy for detection of the gaseous compounds released during heating. Furthermore, the decomposition kinetics and thermodynamics of CaCO{sub 3} in BOFS was evaluated using Arrhenius equation and Kissinger equation. The proposed

Prediction of ozone tropospheric degradation rate constant of organic compounds by using artificial neural networks

International Nuclear Information System (INIS)

Fatemi, M.H.

2006-01-01

Ozone tropospheric degradation of organic compound is very important in environmental chemistry. The lifetime of organic chemicals in the atmosphere can be calculated from the knowledge of the rate constant of their reaction with free radicals such as OH and NO 3 or O 3 . In the present work, the rate constant for the tropospheric degradation of 137 organic compounds by reaction with ozone, the least widely and successfully modeled degradation process, are predicted by quantitative structure activity relationships modeling based on a variety of theoretical descriptors, which screened and selected by genetic algorithm variable subset selection procedure. These descriptors which can be used as inputs for generated artificial neural networks are; HOMO-LUMO gap, number of double bonds, number of single bonds, maximum net charge on C atom, minimum (>0.1) bond order of C atom and Minimum e-e repulsion of H atom. After generation, optimization and training of artificial neural network, network was used for the prediction of log KO 3 for the validation set. The root mean square error for the neural network calculated log KO 3 for training, prediction and validation set are 0.357, 0.460 and 0.481, respectively, which are smaller than those obtained by multiple linear regressions model (1.217, 0.870 and 0.968, respectively). Results obtained reveal the reliability and good predictivity of neural network model for the prediction of ozone tropospheric degradations rate constant of organic compounds

Chemical-genetic profile analysis of five inhibitory compounds in yeast.

Science.gov (United States)

Alamgir, Md; Erukova, Veronika; Jessulat, Matthew; Azizi, Ali; Golshani, Ashkan

2010-08-06

Chemical-genetic profiling of inhibitory compounds can lead to identification of their modes of action. These profiles can help elucidate the complex interactions between small bioactive compounds and the cell machinery, and explain putative gene function(s). Colony size reduction was used to investigate the chemical-genetic profile of cycloheximide, 3-amino-1,2,4-triazole, paromomycin, streptomycin and neomycin in the yeast Saccharomyces cerevisiae. These compounds target the process of protein biosynthesis. More than 70,000 strains were analyzed from the array of gene deletion mutant yeast strains. As expected, the overall profiles of the tested compounds were similar, with deletions for genes involved in protein biosynthesis being the major category followed by metabolism. This implies that novel genes involved in protein biosynthesis could be identified from these profiles. Further investigations were carried out to assess the activity of three profiled genes in the process of protein biosynthesis using relative fitness of double mutants and other genetic assays. Chemical-genetic profiles provide insight into the molecular mechanism(s) of the examined compounds by elucidating their potential primary and secondary cellular target sites. Our follow-up investigations into the activity of three profiled genes in the process of protein biosynthesis provided further evidence concerning the usefulness of chemical-genetic analyses for annotating gene functions. We termed these genes TAE2, TAE3 and TAE4 for translation associated elements 2-4.

Organolanthanoid compounds

International Nuclear Information System (INIS)

Schumann, H.

1984-01-01

Up to little more than a decade ago organolanthanoid compounds were still a curiosity. Apart from the description of an isolated number of cyclopentadienyl and indenyl derivatives, very few significant contributions had been made to this interesting sector of organometallic chemistry. However, subsequent systematic studies using modern preparative and analytical techniques, together with X-ray single crystal structure determinations, enabled the isolation and characterization of a large number of very interesting homoleptic and heteroleptic compounds in which the lanthanoid is bound to hydrogen, to substituted or unsubstituted cyclopentadienyl groups, to allyl or alkynyl groups, or even to phosphorus ylides, trimethylsilyl, and carbonylmetal groups. These compounds, which are all extremely sensitive to oxygen and water, open up new possibilities in the field of catalysis and have great potential in organic synthesis - as recent studies with pentamethylcyclopentadienyl derivatives, organolanthanoid(II) compounds, and hexamethyllanthanoid complexes have already shown. (orig.) [de

[Chemotherapeutic characterization of new nitrosourea compounds].

Science.gov (United States)

Zeller, W J; Berger, M R; Eisenbrand, G; Petru, E

1988-01-01

The development of new nitrosoureas is described using selected examples. Results obtained with water-soluble analogs and with compounds linked to biomolecules as for instance amino acids, oligopeptides and steroids, are presented. The pronounced antineoplastic effect of some water-soluble analogs is paralleled by an increased rate of DNA-interstrand cross-links and by an increased suppression of hematopoietic stem cells. The suppression of bone marrow stem cells is followed by their rapid regeneration. Water-soluble nitrosoureas induce significant less inhibition of glutathione reductase as compared with established compounds. With regard to long-term toxicity and carcinogenicity water-soluble are superior to established compounds as for instance BCNU. Linking of the nitrosourea moiety to amino acids and oligopeptides led to some analogs with outstanding therapeutic ratio. Out of a group of steroid-linked nitrosoureas, CNC-L-alanine-estradiol-17-ester (CNC-ala-17-E2) is chosen to demonstrate the possibility of reducing bone marrow toxicity despite unchanged or increased therapeutic activity by attachment of the nitrosourea moiety to a steroid. Results of a comparative interspecies in vitro evaluation of CNC-ala-17-E2 in transplanted MXT mammary carcinoma of the mouse, MNU-induced autochthonous rat mammary carcinoma and primary human mammary carcinomas are presented and the question is discussed to what extent in vitro activity of such receptor agents using the tumor stem cell assay reflects their in vivo activity.

Check specific compounds lyrics Saeb and Biddle, based on syntactic and semantic core composition

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khodabakhsh asadollahi

2016-02-01

Full Text Available Saebe Tabrizi and Bidele Dehlavi of the most famous poets in Hindi, which each in turn, the Iranian branch and Hindi Hindi style, the lyrics have been changed in this period. Most scholars who have studied the poetry Biddle to research, Specific compounds as one of the most important factors in a monopoly ambiguity Biddle poetry and in the making and meaning of these compounds have less reflection. Here are the lyrics to rely on dictionary and Biddle, the Iranian branch of specific compounds in both Hindi and Hindi poetry style is investigated. Combining both his first two exocentric and endocentric compounds is assorted, Based on Syntactic relations, various models of deep structure and composition relationships is presented. Saeb specific compounds and Biddle in deep syntactic relations as diverse as the relationship between the finite, nominative, accusative, amendment and so on.The semantic structure, certain combinations of the two poets more varied combinations are commonplace in standard language, so that some of the compounds exist in terms of meaning in language

Consumer Understanding of Nutrition Marketing Terms: A Pilot Study

Science.gov (United States)

Haroldson, Amber; Yen, Chih-Lun

2016-01-01

The purpose of this pilot study was to examine the validity of a questionnaire developed to assess adult consumer understanding of nutrition marketing terms and the resulting impact on consumer behavior. Participants (n = 40) completed an electronic questionnaire. Efforts to establish validity and reliability suggest that the questionnaire is a…

Fragrance compounds: The wolves in sheep's clothings.

Science.gov (United States)

Patel, Seema

2017-05-01

In the past few decades, synthetic fragrance compounds have become ubiquitous components of personal care and household cleaning products. Overwhelming consumerism trends have led to the excess usage of these chemicals. It has been observed that this fragrance-laden unhealthy lifestyle runs parallel with the unprecedented rates of diabetes, cancer, neural ailments, teratogenicity, and transgender instances. The link between fragrances as and the multiplicity of pathogens remained latent for decades. However, now this health hazard and its role in homeostasis breakdown is getting attention. The adverse effects of the fragrance constituents as phthalates, paraben, glutaraldehyde, hydroperoxides, oil of turpentine, metals, nitro musks, and essential oils, among others, are being identified. The endocrine-immune-neural axis perturbation pathways of these chemicals are being proven. Despite the revelations of cause-effect nexus, a majority of the vulnerable populations are unaware and unmotivated to avoid these 'slow poisons'. Hence, the researchers need to further validate the toxicity of fragrance compounds, and raise awareness towards the health risks. In this regard, a number of pathologies triggered by fragrance exposure, yet proven only scantily have been hypothesized. Analysis of the health issues from multiple facets, including the pivotal 'stressors - extracellular acidosis - aromatase upregulation - estrogen hyperproduction - inflammation' link has been proposed. Fragrance compounds share configurational similarity with carcinogenic environmental hydrocarbons and they provoke the expression of cytochrome group monooxygenase enzyme aromatase. This enzyme aromatizes androgens to form estrogen, the powerful signaling hormone, which underlies the majority of morbidities. This holistic review with a repertoire of preliminary evidences and robust hypotheses is expected to usher in deserving extent of research on this pervasive health risk. Copyright © 2017 Elsevier

Genetic toxicology of metal compounds: I. Induction of lambda prophage in E coli WP2/sub s/(lambda)

Energy Technology Data Exchange (ETDEWEB)

Rossman, T.G.; Molina, M.; Meyer, L.W.

1984-01-01

A number of metal compounds have been shown to be human carcinogens. Others, while not proven human carcinogens, are able to cause tumors in laboratory animals. Short-term bacterial assays for genotoxic effects have not been successful in predicting the carcinogenicity of metal compounds. The ability of some metal compounds to cause the induction of lambda prophage in E coli WP2/sub s/(lambda) is reported. By far the strongest inducing ability was observed with K/sub 2/CrO/sub 4/. With the exception of chromate, long-term exposures in a narrow, subtoxic dose range were required in order to demonstrate phage induction. A new microtiter assay for lambda prophage induction, which incorporates these features, is described. This system also was able to detect very small amounts of organic carcinogens.

Assessment of the quality of compounded fluconazole capsules marketed in the region of Araraquara (SP, Brazil

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Josilene Chaves Ruela Corrêa

2014-04-01

Full Text Available The quality control of drugs has an important role in public health, in ensuring the efficacy and safety of medicines. In the public health system, compounding pharmacies play a vital part. They provide medicines tailored to the individual patient, for example dermatological products and specific doses for children. Unfortunately, many cases of compounded products falling below the minimum quality standard have been reported in Brazil. In this study, the quality of compounded 150 mg fluconazole capsules was assessed and the results were compared with values stipulated in the Brazilian pharmacopoeia. The results suggest that, while it is certainly possible to prepare products meeting pharmacopoeial specifications, there are pharmacies where the quality control is deficient or nonexistent. Fluconazole is an important drug in combatting fungal infections. The use of fluconazole in dosage forms manufactured without high standards of quality control is strongly linked to treatment failure and cases of intoxication, as well as the emergence of resistant microorganisms. This highlights the urgent need for process improvement in compounding pharmacies. There are validated methods that can be successfully employed for routine quality control analysis that can be implemented by any compounding pharmacy.

48 CFR 252.227-7037 - Validation of restrictive markings on technical data.

Science.gov (United States)

2010-10-01

.... However, this clause neither creates nor implies privity of contract between the Government and... AND CONTRACT CLAUSES Text of Provisions And Clauses 252.227-7037 Validation of restrictive markings on... following clause: Validation of Restrictive Markings on Technical Data (SEP 1999) (a) Definitions. The terms...

Application of HPLC-DAD Technique for Determination of Phenolic Compounds in Bee Pollen Loads

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Waś Ewa

2017-06-01

Full Text Available A method was elaborated to determine phenolic compounds (vanillin, caffeic, p-coumaric and salicylic acids, and flavonoids: rutin, hesperetin, quercetin, pinocembrin, apigenin, kaempferol, isorhamnetin, chrysin, and acacetin in bee pollen loads using highperformance liquid chromatography with a diode array detector (HPLC-DAD. Phenolic compounds from bee pollen were isolated on Cleanert C18-SPE columns (500 mg/6 mL, Agela Technologies. Polyphenols were identified by comparing the retention times and spectra of compounds found in pollen load samples with the ones of the standard mixture. Quantitative analysis was conducted using the external standard method. In addition, basic validation parameters for the method were determined. For the identified compounds (except for the salicylic acid, satisfactory (≥0.997 linear correlations were obtained. The elaborated method showed high repeatability and inter-laboratory reproducibility. Variability coeffcients of the majority of phenolic compounds did not exceed 10% in conditions of repeatability and inter-laboratory reproducibility, and for the total polyphenolic content they were 1.7 and 5.1%, respectively. The pollen load samples (n = 15 differed in qualitative and quantitative composition of the phenolic compounds. In all the samples, we identified the p-coumaric and salicylic acids and flavonoids rutin, hesperetin, and apigenin nevertheless, these compounds’ contents significantly differed among individual samples. The total phenolic content in the tested samples of pollen loads ranged from 0.653 to 5.966 mg/100 g (on average 2.737 mg/100 g.

Benzoquinones and terphenyl compounds as phosphodiesterase-4B inhibitors from a fungus of the order Chaetothyriales (MSX 47445).

Science.gov (United States)

El-Elimat, Tamam; Figueroa, Mario; Raja, Huzefa A; Graf, Tyler N; Adcock, Audrey F; Kroll, David J; Day, Cynthia S; Wani, Mansukh C; Pearce, Cedric J; Oberlies, Nicholas H

2013-03-22

Three bioactive compounds were isolated from an organic extract of an ascomycete fungus of the order Chaetothyriales (MSX 47445) using bioactivity-directed fractionation as part of a search for anticancer leads from filamentous fungi. Of these, two were benzoquinones [betulinan A (1) and betulinan C (3)], and the third was a terphenyl compound, BTH-II0204-207:A (2). The structures were elucidated using a set of spectroscopic and spectrometric techniques; the structure of the new compound (3) was confirmed via single-crystal X-ray diffraction. Compounds 1-3 were evaluated for cytotoxicity against a human cancer cell panel, for antimicrobial activity against Staphylococcus aureus and Candida albicans, and for phosphodiesterase (PDE4B2) inhibitory activities. The putative binding mode of 1-3 with PDE4B2 was examined using a validated docking protocol, and the binding and enzyme inhibitory activities were correlated.

Instructional Support System--Occupational Education II. ISSOE Automotive Mechanics Content Validation.

Science.gov (United States)

Abramson, Theodore

A study was conducted to validate the Instructional Support System-Occupational Education (ISSOE) automotive mechanics curriculum. The following four steps were undertaken: (1) review of the ISSOE materials in terms of their "validity" as task statements; (2) a comparison of the ISSOE tasks to the tasks included in the V-TECS Automotive…

Deep Subseafloor Fungi as an Untapped Reservoir of Amphipathic Antimicrobial Compounds.

Science.gov (United States)

Navarri, Marion; Jégou, Camille; Meslet-Cladière, Laurence; Brillet, Benjamin; Barbier, Georges; Burgaud, Gaëtan; Fleury, Yannick

2016-03-10

The evolving global threat of antimicrobial resistance requires a deep renewal of the antibiotic arsenal including the isolation and characterization of new drugs. Underexplored marine ecosystems may represent an untapped reservoir of novel bioactive molecules. Deep-sea fungi isolated from a record-depth sediment core of almost 2000 m below the seafloor were investigated for antimicrobial activities. This antimicrobial screening, using 16 microbial targets, revealed 33% of filamentous fungi synthesizing bioactive compounds with activities against pathogenic bacteria and fungi. Interestingly, occurrence of antimicrobial producing isolates was well correlated with the complexity of the habitat (in term of microbial richness), as higher antimicrobial activities were obtained at specific layers of the sediment core. It clearly highlights complex deep-sea habitats as chemical battlefields where synthesis of numerous bioactive compounds appears critical for microbial competition. The six most promising deep subseafloor fungal isolates were selected for the production and extraction of bioactive compounds. Depending on the fungal isolates, antimicrobial compounds were only biosynthesized in semi-liquid or solid-state conditions as no antimicrobial activities were ever detected using liquid fermentation. An exception was made for one fungal isolate, and the extraction procedure designed to extract amphipathic compounds was successful and highlighted the amphiphilic profile of the bioactive metabolites.

Linear and nonlinear methods in modeling the aqueous solubility of organic compounds.

Science.gov (United States)

Catana, Cornel; Gao, Hua; Orrenius, Christian; Stouten, Pieter F W

2005-01-01

Solubility data for 930 diverse compounds have been analyzed using linear Partial Least Square (PLS) and nonlinear PLS methods, Continuum Regression (CR), and Neural Networks (NN). 1D and 2D descriptors from MOE package in combination with E-state or ISIS keys have been used. The best model was obtained using linear PLS for a combination between 22 MOE descriptors and 65 ISIS keys. It has a correlation coefficient (r2) of 0.935 and a root-mean-square error (RMSE) of 0.468 log molar solubility (log S(w)). The model validated on a test set of 177 compounds not included in the training set has r2 0.911 and RMSE 0.475 log S(w). The descriptors were ranked according to their importance, and at the top of the list have been found the 22 MOE descriptors. The CR model produced results as good as PLS, and because of the way in which cross-validation has been done it is expected to be a valuable tool in prediction besides PLS model. The statistics obtained using nonlinear methods did not surpass those got with linear ones. The good statistic obtained for linear PLS and CR recommends these models to be used in prediction when it is difficult or impossible to make experimental measurements, for virtual screening, combinatorial library design, and efficient leads optimization.

Traditional Small-Size Citrus from Taiwan: Essential Oils, Bioactive Compounds and Antioxidant Capacity

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Min-Hung Chen

2017-05-01

Full Text Available Background: The calamondin (Citrus microcarpa Bunge and the kumquat (Fortunella crassifolia Swingle are two small-size citrus fruits that have traditionally been consumed in Taiwan; however, there has been a lack of scientific research regarding the active compounds and functionalities of these fruits. Methods: Analysis of volatile composition of essential oil and phytosterol was carried out using Gas Chromatography–Mass Spectrometry (GC-MS. Flavonoid and limonoid were analyzed by High Performance Liquid Chromatography (HPLC. Moreover, antioxidant capacity from their essential oils and extracts were assessed in vitro. Results: The compositions of the essential oils of both fruits were identified, with the results showing that the calamondin and kumquat contain identified 43 and 44 volatile compounds, respectively. In addition, oxygenated compounds of volatiles accounted for 4.25% and 2.04%, respectively, consistent with the fact that oxygenated compounds are generally found in high content in citrus fruits. In terms of flavonoids, the calamondin exhibited higher content than the kumquat, with disomin-based flavonoids being predominant; on the other hand, phytosterol content of kumquat was higher than that of calamondin, with amyrin being the dominant phytosterol. Both of them contain high amounts of limonoids. The ethanol extracts and essential oils of small-sized citrus fruits have been shown to have antioxidant effects, with those effects being closely related to the flavonoid content of the fruit in question. Conclusions: The present study also reviewed antioxidant activity in terms of specific bioactive compounds in order to find the underlying biological activity of both fruits. The calamondin and kumquat have antioxidant effects, which are in turn very important for the prevention of chronic diseases.

Development and validation of a confirmatory method for the determination of 12 non steroidal anti-inflammatory drugs in milk using liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Dubreil-Chéneau, Estelle; Pirotais, Yvette; Bessiral, Mélaine; Roudaut, Brigitte; Verdon, Eric

2011-09-16

A rapid and reliable LC-MS/MS method for the simultaneous confirmation of twelve non steroidal anti-inflammatory drugs (NSAIDs) in bovine milk was developed and fully validated in accordance with the European Commission Decision 2002/657/EC. The validation scheme was built in accordance with the MRLs or target analytical levels (EU-CRL recommended concentrations and detection capabilities) of the analytes, except for diclofenac for which the lower level of validation achieved was 0.5 μg kg(-1) whereas its MRL is 0.1 μg kg(-1). The NSAIDs investigated were as follows: phenylbutazone (PBZ), oxyphenylbutazone (OPB), naproxen (NP), mefenamic acid (MF), vedaprofen (VDP), flunixin (FLU), 5-hydroxyflunixin (FLU-OH), tolfenamic acid (TLF), meloxicam (MLX), diclofenac (DC), carprofen (CPF) and ketoprofen (KTP). Several extraction procedures had been investigated during the development phase. Finally, the best results were obtained with a procedure using only methanol as the extraction solvent, with an evaporation step included and no further purification. Chromatographic separation was achieved on a C18 analytical column and the run was split in 2 segments. Matrix effects were also investigated. Data acquisition implemented for the confirmatory purpose was performed by monitoring 2 MRM transitions per analyte under the negative electrospray mode. Mean relative recoveries ranged from 94.7% to 110.0%, with their coefficients of variation lying between 2.9% and 14.7%. Analytical limits expressed in terms of decision limits (CCα) were evaluated between 0.69 μg kg(-1) (FLU) and 27.54 μg kg(-1) (VDP) for non-MRL compounds, and at 0.10 (DC), 15.37 (MLX), 45.08 (FLU-OH), and 62.96 μg kg(-1) (TLF) for MRL compounds. The validation results proved that the method is suitable for the screening and confirmatory steps as implemented for the French monitoring plan for NSAID residue control in bovine milk. Copyright © 2011 Elsevier B.V. All rights reserved.

The "Case of Two Compounds with Similar Configuration but Nearly Mirror Image CD Spectra" Refuted. Reassignment of the Absolute Configuration of N-Formyl-3',4'-dihydrospiro[indan-1,2'(1'H)-pyridine].

Science.gov (United States)

Padula, Daniele; Di Bari, Lorenzo; Pescitelli, Gennaro

2016-09-02

In 1997, Sandström and co-workers reported the case of two chiral spiro compounds with very similar skeletons but showing almost mirror-image electronic circular dichroism (ECD) spectra for the corresponding absolute configuration. The paper has been often cited as a proof and good educational example of the pronounced sensitivity of ECD toward molecular conformation, and a clear warning against the use of ECD spectral correlations to assign absolute configurations. Although both concepts remain valid, they are not exemplified by the quoted paper. We demonstrate that the original configurational assignment of one compound was wrong and revise it by using TDDFT calculations. The main reason for the observed failure is the use of the matrix method, a popular approach to predict ECD spectra of compounds which can be treated with an independent system approximation (ISA), including proteins. Using a modern version of the matrix method, we demonstrate that the ISA is not valid for the title compound. Even in the absence of apparent conjugation between the component chromophores, the validity of the ISA should never be taken for granted and the effective extent of orbital overlap should always be verified.

[Elimination of volatile compounds of leaf tobacco from air emissions using biofiltration].

Science.gov (United States)

Zagustina, N A; Misharina, T A; Vepritskiĭ, A A; Zhukov, V G; Ruzhitskiĭ, A O; Terenina, M B; Krikunova, N I; Kulikova, A K; Popov, V O

2012-01-01

The composition of the volatile organic compounds (VOCs) of various leaf tobacco brands and their blends has been studied. The differences in the content of nicotine, solanone, tetramethyl hexadecenol, megastigmatrienones, and other compounds, determining the specific tobacco smell, have been revealed. A microbial consortium, which is able to deodorize simulated tobacco emissions and decompose nicotine, has been formed by long-term adaptation to the VOCs of tobacco leaves in a laboratory reactor, functioning as a trickle-bed biofilter. Such a biofilter eliminates 90% of the basic toxic compound (nicotine) and odor-active compounds; the filtration efficiency does not change for tobacco brands with different VOC concentrations or in the presence of foreign substances. The main strains, isolated from the formed consortium and participating in the nicotine decomposition process, belong to the genera Pseudomonas, Bacillus, and Rhodococcus. An examination of the biofilter trickling fluid has shown full decomposition of nicotine and odor-active VOCs. The compounds, revealed in the trickling fluid, did not have any odor and were nontoxic. The obtained results make it possible to conduct scaling of the biofiltration process to eliminate odor from air emissions in the tobacco industry.

Electrohydrodynamics of a concentric compound drop in an AC electric field

Science.gov (United States)

Soni, Purushottam; Thaokar, Rochish M.; Juvekar, Vinay A.

2018-03-01

The dynamics of a compound drop suspended in another immiscible fluid in the presence of an AC electric field is investigated experimentally and using analytical theory. A closed-form analytical expression for the mean deformation and amplitude of deformation at cyclical steady state is derived in the small deformation limit. Experiments were performed with 0.1M NaCl/castor oil compound drops suspended in highly viscous silicone oil. In this case, both the core and the shell deform into prolate spheroids. The effect of two independent variables was investigated, namely, the ratio of the core radius to the shell radius and the frequency (ω) of the applied AC field. In the limit of ω → 0, the present analytical model reduces to the DC electric field model for the compound drop. It was observed that the size of the core significantly affects the dynamics of the compound drop. The mean and the amplitude of deformation of the shell increase considerably with an increase in the radius ratio. Since the present model is valid for a small deviation from a spherical shape, an excellent quantitative agreement is found between analytical and experimental results at low deformation, whereas, at large deformation, the match is only qualitative. It was also observed that the relative phase difference between the core and the shell decreases with an increase in the radius ratio and frequency of the applied electric field.

Nanomaterial-Based Sensing and Biosensing of Phenolic Compounds and Related Antioxidant Capacity in Food.

Science.gov (United States)

Della Pelle, Flavio; Compagnone, Dario

2018-02-04

Polyphenolic compounds (PCs) have received exceptional attention at the end of the past millennium and as much at the beginning of the new one. Undoubtedly, these compounds in foodstuffs provide added value for their well-known health benefits, for their technological role and also marketing. Many efforts have been made to provide simple, effective and user friendly analytical methods for the determination and antioxidant capacity (AOC) evaluation of food polyphenols. In a parallel track, over the last twenty years, nanomaterials (NMs) have made their entry in the analytical chemistry domain; NMs have, in fact, opened new paths for the development of analytical methods with the common aim to improve analytical performance and sustainability, becoming new tools in quality assurance of food and beverages. The aim of this review is to provide information on the most recent developments of new NMs-based tools and strategies for total polyphenols (TP) determination and AOC evaluation in food. In this review optical, electrochemical and bioelectrochemical approaches have been reviewed. The use of nanoparticles, quantum dots, carbon nanomaterials and hybrid materials for the detection of polyphenols is the main subject of the works reported. However, particular attention has been paid to the success of the application in real samples, in addition to the NMs. In particular, the discussion has been focused on methods/devices presenting, in the opinion of the authors, clear advancement in the fields, in terms of simplicity, rapidity and usability. This review aims to demonstrate how the NM-based approaches represent valid alternatives to classical methods for polyphenols analysis, and are mature to be integrated for the rapid quality assessment of food quality in lab or directly in the field.

Compounding approach for univariate time series with nonstationary variances

Science.gov (United States)

Schäfer, Rudi; Barkhofen, Sonja; Guhr, Thomas; Stöckmann, Hans-Jürgen; Kuhl, Ulrich

2015-12-01

A defining feature of nonstationary systems is the time dependence of their statistical parameters. Measured time series may exhibit Gaussian statistics on short time horizons, due to the central limit theorem. The sample statistics for long time horizons, however, averages over the time-dependent variances. To model the long-term statistical behavior, we compound the local distribution with the distribution of its parameters. Here, we consider two concrete, but diverse, examples of such nonstationary systems: the turbulent air flow of a fan and a time series of foreign exchange rates. Our main focus is to empirically determine the appropriate parameter distribution for the compounding approach. To this end, we extract the relevant time scales by decomposing the time signals into windows and determine the distribution function of the thus obtained local variances.

Optimization and validation of liquid chromatography and headspace-gas chromatography based methods for the quantitative determination of capsaicinoids, salicylic acid, glycol monosalicylate, methyl salicylate, ethyl salicylate, camphor and l-menthol in a topical formulation.

Science.gov (United States)

Pauwels, Jochen; D'Autry, Ward; Van den Bossche, Larissa; Dewever, Cédric; Forier, Michel; Vandenwaeyenberg, Stephanie; Wolfs, Kris; Hoogmartens, Jos; Van Schepdael, Ann; Adams, Erwin

2012-02-23

Capsaicinoids, salicylic acid, methyl and ethyl salicylate, glycol monosalicylate, camphor and l-menthol are widely used in topical formulations to relieve local pain. For each separate compound or simple mixtures, quantitative analysis methods are reported. However, for a mixture containing all above mentioned active compounds, no assay methods were found. Due to the differing physicochemical characteristics, two methods were developed and optimized simultaneously. The non-volatile capsaicinoids, salicylic acid and glycol monosalicylate were analyzed with liquid chromatography following liquid-liquid extraction, whereas the volatile compounds were analyzed with static headspace-gas chromatography. For the latter method, liquid paraffin was selected as compatible dilution solvent. The optimized methods were validated in terms of specificity, linearity, accuracy and precision in a range of 80% to 120% of the expected concentrations. For both methods, peaks were well separated without interference of other compounds. Linear relationships were demonstrated with R² values higher than 0.996 for all compounds. Accuracy was assessed by performing replicate recovery experiments with spiked blank samples. Mean recovery values were all between 98% and 102%. Precision was checked at three levels: system repeatability, method precision and intermediate precision. Both methods were found to be acceptably precise at all three levels. Finally, the method was successfully applied to the analysis of some real samples (cutaneous sticks). Copyright © 2011 Elsevier B.V. All rights reserved.

Predicting Heats of Explosion of Nitroaromatic Compounds through NBO Charges and 15N NMR Chemical Shifts of Nitro Groups

Directory of Open Access Journals (Sweden)

Ricardo Infante-Castillo

2012-01-01

Full Text Available This work presents a new quantitative model to predict the heat of explosion of nitroaromatic compounds using the natural bond orbital (NBO charge and 15N NMR chemical shifts of the nitro groups (15NNitro as structural parameters. The values of the heat of explosion predicted for 21 nitroaromatic compounds using the model described here were compared with experimental data. The prediction ability of the model was assessed by the leave-one-out cross-validation method. The cross-validation results show that the model is significant and stable and that the predicted accuracy is within 0.146 MJ kg−1, with an overall root mean squared error of prediction (RMSEP below 0.183 MJ kg−1. Strong correlations were observed between the heat of explosion and the charges (R2 = 0.9533 and 15N NMR chemical shifts (R2 = 0.9531 of the studied compounds. In addition, the dependence of the heat of explosion on the presence of activating or deactivating groups of nitroaromatic explosives was analyzed. All calculations, including optimizations, NBO charges, and 15NNitro NMR chemical shifts analyses, were performed using density functional theory (DFT and a 6-311+G(2d,p basis set. Based on these results, this practical quantitative model can be used as a tool in the design and development of highly energetic materials (HEM based on nitroaromatic compounds.

The formation of lithium diarylargentates from arylsilver compounds and the corresponding aryllithium compounds

NARCIS (Netherlands)

Blenkers, J.; Hofstee, H.K.; Boersma, J.; Kerk, G.J.M. van der

1979-01-01

Diarylsilverlithium compounds of the type Ar2AgLi are formed by treating arylsilver compounds with the corresponding aryllithium compounds. Cryoscopy in benzene shows that the Ar2AgLi compounds are associated into dimers. NMR spectroscopic data indicate that only one type of aryl group is present in

Simultaneous estimation of Ofloxacin and Cefixime in tablet form in presence of the inactive Ofloxacin USP Related compound A

Directory of Open Access Journals (Sweden)

Lobna A. Hussein

2017-06-01

The suggested method was validated in compliance with the ICH guidelines and was successfully applied for the quantification of Ofloxacin, Cefixime and Ofloxacin Related compound A in their commercial tablets. The method was also statistically compared to reference methods with no significant differences in performance.

Assessing conflict communication in couples: comparing the validity of self-report, partner-report, and observer ratings.

Science.gov (United States)

Sanford, Keith

2010-04-01

This study of married couples investigated the short-term predictive validity of the partner-report and self-report scales of the Conflict Communication Inventory and compared the validity of these scales with the validity of observer ratings. A sample of 83 married couples completed two problem-solving conversations. Self-report, partner-report, and observer ratings from Conversation 1 were used to predict behavior in Conversation 2, as rated by a separate panel of observers. The short-term predictive validity of partner-report ratings was extremely high and indistinguishable from the validity of observer ratings. Self-report ratings also demonstrated good validity, albeit slightly lower than other methods. Both partner-report and self-report scores explained a substantial amount of variance in concurrent observer ratings of communication after controlling for relationship satisfaction. 2010 APA, all rights reserved

Development and Validation of Triarchic Construct Scales from the Psychopathic Personality Inventory

Science.gov (United States)

Hall, Jason R.; Drislane, Laura E.; Patrick, Christopher J.; Morano, Mario; Lilienfeld, Scott O.; Poythress, Norman G.

2014-01-01

The Triarchic model of psychopathy describes this complex condition in terms of distinct phenotypic components of boldness, meanness, and disinhibition. Brief self-report scales designed specifically to index these psychopathy facets have thus far demonstrated promising construct validity. The present study sought to develop and validate scales for assessing facets of the Triarchic model using items from a well-validated existing measure of psychopathy—the Psychopathic Personality Inventory (PPI). A consensus rating approach was used to identify PPI items relevant to each Triarchic facet, and the convergent and discriminant validity of the resulting PPI-based Triarchic scales were evaluated in relation to multiple criterion variables (i.e., other psychopathy inventories, antisocial personality disorder features, personality traits, psychosocial functioning) in offender and non-offender samples. The PPI-based Triarchic scales showed good internal consistency and related to criterion variables in ways consistent with predictions based on the Triarchic model. Findings are discussed in terms of implications for conceptualization and assessment of psychopathy. PMID:24447280

Analyses of the activation of near term fusion reactor compound materials

International Nuclear Information System (INIS)

Lengar, I.

2007-01-01

One of the important questions that still have to be solved for the next generation fusion reactors is the choice of the material to be used for the first wall. An important criteria is low activation due to neutron bombardment from the plasma. One of the promising materials is the SiC/SiC composite. Its main elemental constituents, namely the C and Si, have very good activation characteristics. The main contribution to activity arises, however, from trace elements, which are needed in the sintering process and remain in the material afterwards. Before the preparation process of the material, the activation characteristics of individual constituents are needed. The activation properties of the whole sample could than be estimated by summing the weighted properties of individual constituents. The activity of a particular trace element is, however, not necessarily dependent only on the percentage of the element in the sample, but also on the presence of other elements in the compound due to the charge particle production and/or (n, 2n) reactions. The extension of this effect is investigated and to what extent individual calculations, performed for a single element, mimic the real situation. Further the activation characteristic for several possible sintering aid elements is theoretically investigated with the use of the FISPACT inventory code. (author)

Multiple Coulomb excitation effects in heavy ion compound and fusion cross sections

International Nuclear Information System (INIS)

Carlson, B.V.; Hussein, M.S.

1981-11-01

A simple model for the average S-matrix that describes heavy ion direct processes in the presence of absorption due to compound nucleus formation is developed. The fluctuation cross section and the fusion cross section are then calculated for deformed heavy ion systems where multiple Coulomb excitation is important. A simple expression for the fusion cross section valid for above-barrier energies is then obtained. The formula clearly displays the modification, due to Coulomb excitation, in the usual geometrical expression. (Author) [pt

Validation of an experimental setup to study atmospheric heterogeneous ozonolysis of semi-volatile organic compounds

Directory of Open Access Journals (Sweden)

M. Pflieger

2009-03-01

Full Text Available There is currently a need for reliable experimental procedures to follow the heterogeneous processing simulating the atmospheric conditions. This work offers an alternative experimental device to study the behaviour of semi-volatile organic compounds (SVOC that presumably exhibit extremely slow reactivity (e.g. pesticides towards the atmospheric oxidants such as ozone and OH. Naphthalene was chosen as a test compound since it was widely studied in the past and hence represents a good reference. Prior to ozone exposure, the gaseous naphthalene was adsorbed via gas-solid equilibrium on silica and XAD-4 particles. Then, the heterogeneous reaction of ozone with adsorbed naphthalene was investigated in specially designed flow tube reactors. After the reaction, the remaining naphthalene (adsorbed on particles surface was extracted, filtered and analyzed by Gas Chromatography-Flame Ionization Detector (GC-FID. Thus, the kinetics results were obtained following the consumption of naphthalene. Using this procedure, the rate constants of heterogeneous ozonolysis of naphthalene (k_O3 silica=2.26 (±0.09×10⁻¹⁷ cm³ molec⁻¹ s⁻¹ and k_O3 XAD-4=4.29 (±1.06×10⁻¹⁹ cm³ molec⁻¹ s⁻¹ were determined for silica and XAD-4 particles, at 25°C and relative humidity <0.7%. The results show that the nature of the particles significantly affects the kinetics and that heterogeneous ozonolysis of naphthalene is faster than its homogeneous ozonolysis in the gas phase.

Kinetic isotope effects and aliphatic diazo-compounds

International Nuclear Information System (INIS)

Albery, W.J.; Conway, C.W.; Hall, J.A.

1976-01-01

Results are reported for the variation of the rate of decomposition of ethyl diazomalonate (EDM) and diazomalonate anions with pH and for the deuterium solvent isotope effect for EDM. The shape of the pH profile is explained by successive protonations of the anions. Ethyl diazoacetate is observed as an intermediate in the decomposition of EDM. The degree of proton transfer in the EDM transition state is deduced from the solvent isotope effect and the results together with those for other aliphatic diazo-compounds are discussed in terms of the Marcus theory. (author)

Calculating the Solubilities of Drugs and Drug-Like Compounds in Octanol.

Science.gov (United States)

Alantary, Doaa; Yalkowsky, Samuel

2016-09-01

A modification of the Van't Hoff equation is used to predict the solubility of organic compounds in dry octanol. The new equation describes a linear relationship between the logarithm of the solubility of a solute in octanol to its melting temperature. More than 620 experimentally measured octanol solubilities, collected from the literature, are used to validate the equation without using any regression or fitting. The average absolute error of the prediction is 0.66 log units. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Nitrofuranyl Methyl Piperazines as New Anti-TB Agents: Identification, Validation, Medicinal Chemistry, and PK Studies

Science.gov (United States)

2015-01-01

Whole-cell screening of 20,000 drug-like small molecules led to the identification of nitrofuranyl methylpiperazines as potent anti-TB agents. In the present study, validation followed by medicinal chemistry has been used to explore the structure–activity relationship. Ten compounds demonstrated potent MIC in the range of 0.17–0.0072 μM against H37Rv Mycobacterium tuberculosis (MTB) and were further investigated against nonreplicating and resistant (RifR and MDR) strains of MTB. These compounds were also tested for cytotoxicity. Among the 10 tested compounds, five showed submicromolar to nanomolar potency against nonreplicating and resistant (RifR and MDR) strains of MTB along with a good safety index. Based on their overall in vitro profiles, the solubility and pharmacokinetic properties of five potent compounds were studied, and two analogues, 14f and 16g, were found to have comparatively better solubility than others tested and acceptable pharmacokinetic properties. This study presents the rediscovery of a nitrofuranyl class of compounds with improved aqueous solubility and acceptable oral PK properties, opening a new direction for further development. PMID:26487909

Semiconducting III-V compounds

CERN Document Server

Hilsum, C; Henisch, Heinz R

1961-01-01

Semiconducting III-V Compounds deals with the properties of III-V compounds as a family of semiconducting crystals and relates these compounds to the monatomic semiconductors silicon and germanium. Emphasis is placed on physical processes that are peculiar to III-V compounds, particularly those that combine boron, aluminum, gallium, and indium with phosphorus, arsenic, and antimony (for example, indium antimonide, indium arsenide, gallium antimonide, and gallium arsenide).Comprised of eight chapters, this book begins with an assessment of the crystal structure and binding of III-V compounds, f

Fabrication and electrical characterization of Al/diazo compound containing polyoxy chain/p-Si device structure

International Nuclear Information System (INIS)

Birel, Ozgul; Kavasoglu, Nese; Kavasoglu, A. Sertap; Dincalp, Haluk; Metin, Bengul

2013-01-01

Diazo-compounds are important class of chemical compounds in terms of optical and electronic properties which make them potentially attractive for device applications. Diazo compound containing polyoxy chain has been deposited on p-Si. Current–voltage characteristics of Al/diazo compound containing polyoxy chain/p-Si structure present rectifying behaviour. The Schottky barrier height (SBH), diode factor (n), reverse saturation current (I o ), interface state density (N ss ) of Al/diazo compound containing polyoxy chain/p-Si structure have been calculated from experimental forward bias current–voltage data measured in the temperature range 100–320 K and capacitance–voltage data measured at room temperature and 1 MHz. The calculated values of SBH have ranged from 0.041 and 0.151 eV for the high and low temperature regions. Diode factor values fluctuate between the values 14 and 18 with temperature. Such a high diode factors stem from disordered interface layer in a junction structure as stated by Brötzmann et al. [M. Brötzmann, U. Vetter, H. Hofsäss, J. Appl. Phys. 106 (2009) 063704]. The calculated values of saturation current have ranged from 3×10 −11 A to 2.79×10 −7 A and interface state density have ranged from 5×10 11 eV −1 cm −2 and 4×10 13 eV −1 cm −2 as temperature increases. Results show that Al/diazo compound containing polyoxy chain/p-Si structure is a valuable candidate for device applications in terms of low reverse saturation current and low interface state density

Fabrication and electrical characterization of Al/diazo compound containing polyoxy chain/p-Si device structure

Energy Technology Data Exchange (ETDEWEB)

Birel, Ozgul [Mugla Sitki Kocman University, Faculty of Science, Chemistry Department, 48000-Muğla (Turkey); Kavasoglu, Nese, E-mail: knesese@gmail.com [Mugla Sitki Kocman University, Faculty of Science, Physics Department, Photovoltaic Material and Device Laboratory, 48000-Muğla (Turkey); Kavasoglu, A. Sertap [Mugla Sitki Kocman University, Faculty of Science, Physics Department, Photovoltaic Material and Device Laboratory, 48000-Muğla (Turkey); Dincalp, Haluk [Celal Bayar University, Faculty of Arts and Science, Chemistry Department, 45000-Manisa (Turkey); Metin, Bengul [Mugla Sitki Kocman University, Faculty of Science, Physics Department, Photovoltaic Material and Device Laboratory, 48000-Muğla (Turkey)

2013-03-01

Diazo-compounds are important class of chemical compounds in terms of optical and electronic properties which make them potentially attractive for device applications. Diazo compound containing polyoxy chain has been deposited on p-Si. Current–voltage characteristics of Al/diazo compound containing polyoxy chain/p-Si structure present rectifying behaviour. The Schottky barrier height (SBH), diode factor (n), reverse saturation current (I{sub o}), interface state density (N{sub ss}) of Al/diazo compound containing polyoxy chain/p-Si structure have been calculated from experimental forward bias current–voltage data measured in the temperature range 100–320 K and capacitance–voltage data measured at room temperature and 1 MHz. The calculated values of SBH have ranged from 0.041 and 0.151 eV for the high and low temperature regions. Diode factor values fluctuate between the values 14 and 18 with temperature. Such a high diode factors stem from disordered interface layer in a junction structure as stated by Brötzmann et al. [M. Brötzmann, U. Vetter, H. Hofsäss, J. Appl. Phys. 106 (2009) 063704]. The calculated values of saturation current have ranged from 3×10{sup −11} A to 2.79×10{sup −7} A and interface state density have ranged from 5×10{sup 11} eV{sup −1} cm{sup −2} and 4×10{sup 13} eV{sup −1} cm{sup −2} as temperature increases. Results show that Al/diazo compound containing polyoxy chain/p-Si structure is a valuable candidate for device applications in terms of low reverse saturation current and low interface state density.

Passive Sampling in Regulatory Chemical Monitoring of Nonpolar Organic Compounds in the Aquatic Environment

DEFF Research Database (Denmark)

Booij, Kees; Robinson, Craig D; Burgess, Robert M

2016-01-01

We reviewed compliance monitoring requirements in the European Union, the United States, and the Oslo-Paris Convention for the protection of the marine environment of the North-East Atlantic, and evaluated if these are met by passive sampling methods for nonpolar compounds. The strengths...... is the best available technology for chemical monitoring of nonpolar organic compounds. Key issues to be addressed by scientists and environmental managers are outlined....... and shortcomings of passive sampling are assessed for water, sediments, and biota. Passive water sampling is a suitable technique for measuring concentrations of freely dissolved compounds. This method yields results that are incompatible with the EU's quality standard definition in terms of total concentrations...

Long Term Validity of Monetary Exchange Rate Model: Evidence from Turkey

Directory of Open Access Journals (Sweden)

Ugur Ahmet

2014-03-01

Full Text Available In this study, it was analyzed if there is a long term relationship among the nominal exchange rate and monetary fundamentals within the periods of 1998:1-2011:2 in Turkey. This relationship has been analysed by using structural VAR (SVAR model. Besides, Granger causality test and Dolado-Lütkepohl Granger causality test were used to determine if there were a causality relationship among the nominal exchange rate and monetary fundamentals. As a result of the SVAR model, the relationship among the series related to nominal exchange rate and money supply, GDP, interest rate in Turkey in long term were not determined and at the end of causality tests, causality relationship among the nominal exchange rate and monetary fundamentals were not determined.

Quantitative Prediction of Solvation Free Energy in Octanol of Organic Compounds

Directory of Open Access Journals (Sweden)

Eduardo J. Delgado

2009-03-01

Full Text Available The free energy of solvation, ΔGS0 , in octanol of organic compunds is quantitatively predicted from the molecular structure. The model, involving only three molecular descriptors, is obtained by multiple linear regression analysis from a data set of 147 compounds containing diverse organic functions, namely, halogenated and non-halogenated alkanes, alkenes, alkynes, aromatics, alcohols, aldehydes, ketones, amines, ethers and esters; covering a ΔGS0 range from about –50 to 0 kJ·mol-1. The model predicts the free energy of solvation with a squared correlation coefficient of 0.93 and a standard deviation, 2.4 kJ·mol-1, just marginally larger than the generally accepted value of experimental uncertainty. The involved molecular descriptors have definite physical meaning corresponding to the different intermolecular interactions occurring in the bulk liquid phase. The model is validated with an external set of 36 compounds not included in the training set.

Quantification of Selected Vapour-Phase Compounds using Thermal Desorption-Gas Chromatography

Directory of Open Access Journals (Sweden)

McLaughlin DWJ

2014-12-01

Full Text Available A robust method for the analysis of selected vapour phase (VP compounds in mainstream smoke (MSS is described. Cigarettes are smoked on a rotary smoking machine and the VP that passes through the Cambridge filter pad collected in a TedlarA¯ bag. On completion of smoking, the bag contents are sampled onto an adsorption tube containing a mixed carbon bed. The tube is subsequently analysed on an automated thermal desorption (TD system coupled to a gas chromatography-flame ionization detector (GC-FID using a PoraPLOT-Q column. Quantification of 14 volatile compounds including the major carbonyls is achieved. Details of the method validation data are included in this paper. This method has been used to analyse the VP of cigarette MSS over a wide range of ‘tar’ deliveries and configurations with excellent repeatability. Results for the University of Kentucky reference cigarette 1R4F are in good agreement with reported values.

Regiospecific analysis of neutral ether lipids by liquid chromatography/electrospray ionization/single quadrupole mass spectrometry: validation with synthetic compounds

DEFF Research Database (Denmark)

Hartvigsen, Karsten; Ravandi, A.; Bukhave, Klaus

2001-01-01

A reversed-phase high-performance liquid chromatography (HPLC) method with on-line electrospray ionization/collision-induced dissociation/mass spectrometry (ESI/CID/MS) is presented for the regiospecific analysis of synthetic reference compounds of neutral ether lipids. The reference compounds were...... characterized by chromatographic retention times, full mass spectra, and fragmentation patterns as an aid to clarify the regiospecificity of ether lipids from natural sources. The results clearly show that single quadrupole mass spectroscopic analysis may elucidate the regiospecific structure of neutral ether...... + H - H2O](+), whereas the reverse situation characterized the sn-3 species. Furthermore, corresponding sn-2 and sn-3 species were separated by the chromatographic system. However, loss of water was promoted as fatty acid unsaturation was raised, which may complicate interpretation of the mass spectra...

Predictive Validity of the Columbia-Suicide Severity Rating Scale for Short-Term Suicidal Behavior: A Danish Study of Adolescents at a High Risk of Suicide.

Science.gov (United States)

Conway, Paul Maurice; Erlangsen, Annette; Teasdale, Thomas William; Jakobsen, Ida Skytte; Larsen, Kim Juul

2017-07-03

Using the Columbia-Suicide Severity Rating Scale (C-SSRS), we examined the predictive and incremental predictive validity of past-month suicidal behavior and ideation for short-term suicidal behavior among adolescents at high risk of suicide. The study was conducted in 2014 on a sample of 85 adolescents (90.6% females) who participated at follow-up (85.9%) out of the 99 (49.7%) baseline respondents. All adolescents were recruited from a specialized suicide-prevention clinic in Denmark. Through multivariate logistic regression analyses, we examined whether baseline suicidal behavior predicted subsequent suicidal behavior (actual attempts and suicidal behavior of any type, including preparatory acts, aborted, interrupted and actual attempts; mean follow-up of 80.8 days, SD = 52.4). Furthermore, we examined whether suicidal ideation severity and intensity incrementally predicted suicidal behavior at follow-up over and above suicidal behavior at baseline. Actual suicide attempts at baseline strongly predicted suicide attempts at follow-up. Baseline suicidal ideation severity and intensity did not significantly predict future actual attempts over and above baseline attempts. The suicidal ideation intensity items deterrents and duration were significant predictors of subsequent actual attempts after adjustment for baseline suicide attempts and suicidal behavior of any type, respectively. Suicidal ideation severity and intensity, and the intensity items frequency, duration and deterrents, all significantly predicted any type of suicidal behavior at follow-up, also after adjusting for baseline suicidal behavior. The present study points to an incremental predictive validity of the C-SSRS suicidal ideation scales for short-term suicidal behavior of any type among high-risk adolescents.

Validation of the Long-term Difficulties Inventory (LDI) and the List of Threatening Experiences (LTE) as measures of stress in epidemiological population-based cohort studies.

Science.gov (United States)

Rosmalen, J G M; Bos, E H; de Jonge, P

2012-12-01

Stress questionnaires are included in many epidemiological cohort studies but the psychometric characteristics of these questionnaires are largely unknown. The aim of this study was to describe these characteristics for two short questionnaires measuring the lifetime and past year occurrence of stress: the List of Threatening Events (LTE) as a measure of acute stress and the Long-term Difficulties Inventory (LDI) as a measure of chronic stress. This study was performed in a general population cohort consisting of 588 females (53.7%) and 506 males (46.3%), with a mean age of 53.5 years (s.d.=11.3 years). Respondents completed the LTE and the LDI for the past year, and for the age categories of 0-12, 13-18, 19-39, 40-60, and >60 years. They also completed questionnaires on perceived stress, psychological distress (the General Health Questionnaire, GHQ-12), anxiety and depression (the Symptom Checklist, SCL-8) and neuroticism (the Eysenck Personality Questionnaire - Revised Short Scale, EPQ-RSS-N). Approximately 2 years later, 976 respondents (89%) completed these questionnaires for a second time. The stability of the retrospective reporting of long-term difficulties and life events was satisfactory: 0.7 for the lifetime LDI and 0.6 for the lifetime LTE scores. The construct validity of these lists is indicated by their positive associations with psychological distress, mental health problems and neuroticism. This study in a large population-based sample shows that the LDI and LTE have sufficient validity and stability to include them in major epidemiological cohort studies.

Use of a standardized JaCVAM in vivo rat comet assay protocol to assess the genotoxicity of three coded test compounds; ampicillin trihydrate, 1,2-dimethylhydrazine dihydrochloride, and N-nitrosodimethylamine.

Science.gov (United States)

McNamee, J P; Bellier, P V

2015-07-01

As part of the Japanese Center for the Validation of Alternative Methods (JaCVAM)-initiative international validation study of the in vivo rat alkaline comet assay (comet assay), our laboratory examined ampicillin trihydrate (AMP), 1,2-dimethylhydrazine dihydrochloride (DMH), and N-nitrosodimethylamine (NDA) using a standard comet assay validation protocol (v14.2) developed by the JaCVAM validation management team (VMT). Coded samples were received by our laboratory along with basic MSDS information. Solubility analysis and range-finding experiments of the coded test compounds were conducted for dose selection. Animal dosing schedules, the comet assay processing and analysis, and statistical analysis were conducted in accordance with the standard protocol. Based upon our blinded evaluation, AMP was not found to exhibit evidence of genotoxicity in either the rat liver or stomach. However, both NDA and DMH were observed to cause a significant increase in % tail DNA in the rat liver at all dose levels tested. While acute hepatoxicity was observed for these compounds in the high dose group, in the investigators opinion there were a sufficient number of consistently damaged/measurable cells at the medium and low dose groups to judge these compounds as genotoxic. There was no evidence of genotoxicity from either NDA or DMH in the rat stomach. In conclusion, our laboratory observed increased DNA damage from two blinded test compounds in rat liver (later identified as genotoxic carcinogens), while no evidence of genotoxicity was observed for the third blinded test compound (later identified as a non-genotoxic, non-carcinogen). This data supports the use of a standardized protocol of the in vivo comet assay as a cost-effective alternative genotoxicity assay for regulatory testing purposes. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Validation of RetroPath, a computer-aided design tool for metabolic pathway engineering.

Science.gov (United States)

Fehér, Tamás; Planson, Anne-Gaëlle; Carbonell, Pablo; Fernández-Castané, Alfred; Grigoras, Ioana; Dariy, Ekaterina; Perret, Alain; Faulon, Jean-Loup

2014-11-01

Metabolic engineering has succeeded in biosynthesis of numerous commodity or high value compounds. However, the choice of pathways and enzymes used for production was many times made ad hoc, or required expert knowledge of the specific biochemical reactions. In order to rationalize the process of engineering producer strains, we developed the computer-aided design (CAD) tool RetroPath that explores and enumerates metabolic pathways connecting the endogenous metabolites of a chassis cell to the target compound. To experimentally validate our tool, we constructed 12 top-ranked enzyme combinations producing the flavonoid pinocembrin, four of which displayed significant yields. Namely, our tool queried the enzymes found in metabolic databases based on their annotated and predicted activities. Next, it ranked pathways based on the predicted efficiency of the available enzymes, the toxicity of the intermediate metabolites and the calculated maximum product flux. To implement the top-ranking pathway, our procedure narrowed down a list of nine million possible enzyme combinations to 12, a number easily assembled and tested. One round of metabolic network optimization based on RetroPath output further increased pinocembrin titers 17-fold. In total, 12 out of the 13 enzymes tested in this work displayed a relative performance that was in accordance with its predicted score. These results validate the ranking function of our CAD tool, and open the way to its utilization in the biosynthesis of novel compounds. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of Chemistry Game Card as an Instructional Media in the Subject of Naming Chemical Compound in Grade X

Science.gov (United States)

Bayharti; Iswendi, I.; Arifin, M. N.

2018-04-01

The purpose of this research was to produce a chemistry game card as an instructional media in the subject of naming chemical compounds and determine the degree of validity and practicality of instructional media produced. Type of this research was Research and Development (R&D) that produced a product. The development model used was4-D model which comprises four stages incuding: (1) define, (2) design, (3) develop, and (4) disseminate. This research was restricted at the development stage. Chemistry game card developed was validated by seven validators and practicality was tested to class X6 students of SMAN 5 Padang. Instrument of this research is questionnair that consist of validity sheet and practicality sheet. Technique in collection data was done by distributing questionnaire to the validators, chemistry teachers, and students. The data were analyzed by using formula Cohen’s Kappa. Based on data analysis, validity of chemistry game card was0.87 with category highly valid and practicality of chemistry game card was 0.91 with category highly practice.

Neutron scattering investigation of layer-bending modes in alkali-metal--graphite intercalation compounds

International Nuclear Information System (INIS)

Zabel, H.; Kamitakahara, W.A.; Nicklow, R.M.

1982-01-01

Phonon dispersion curves for low-frequency transverse modes propagating in the basal plane have been measured in the alkali-metal--graphite intercalation compounds KC 8 , CsC 8 , KC 24 , and RbC 24 by means of neutron spectroscopy. The acoustic branches show an almost quadratic dispersion relation at small q, characteristic of strongly layered materials. The optical branches of stage-1 compounds can be classified as either graphitelike branches showing dispersion, or as almost dispersionless alkali-metal-like modes. Macroscopic shear constants C 44 and layer-bending moduli have been obtained for the intercalation compounds by analyzing the data in terms of a simple semicontinuum model. In stage-2 compounds, a dramatic softening of the shear constant by about a factor of 8 compared with pure graphite has been observed. Low-temperature results on KC 24 indicate the opening of a frequency gap near the alkali-metal Brillouin-zone boundary, possibly due to the formation of the alkali-metal superstructure

French Translation and Validation of Three Scales Evaluating Stigma in Mental Health

Directory of Open Access Journals (Sweden)

Carla Garcia

2017-12-01

Full Text Available ObjectiveThe concept of stigma refers to problems of knowledge (ignorance, attitudes (prejudice, and behavior (discrimination. Stigma may hinder access to care, housing, and work. In the context of implementation of programs such as “housing first” or “individual placement and support” in French speaking regions, validated instruments measuring stigma are necessary. “Attitudes to Mental Illness 2011” is a questionnaire that includes three scales measuring stigma through these three dimensions. This study aimed to translate, adapt, and validate these three scales in French.MethodsThe “Attitudes to Mental Illness 2011” questionnaire was translated into French and back-translated into English by an expert. Two hundred and sixty-eight nursing students completed the questionnaire. Content validity, face validity, internal validity, and convergent validity were assessed. Long-term reliability was also estimated over a three-month period.ResultsExperts and participants found that the questionnaire’s content validity and face validity were appropriate. The internal validities of the three scales were also considered adequate. Convergent validity indicated that the scales did indeed measure what they were supposed to. Long-term stability estimates were moderate; this pattern of results suggested that the construct targeted by the three scales is adequately measured but does not necessarily represent stable and enduring traits.ConclusionBecause of their good psychometric properties, these three scales can be used in French, either separately, to measure one specific dimension of stigma, or together, to assess stigma in its three dimensions. This would seem of paramount importance in evaluating campaigns against stigma since it allows measures to be adapted according to campaign goals and the target population.

Selenium-75-labelled foliate compounds

International Nuclear Information System (INIS)

1974-01-01

A saturation method to analyze a foliate is presented; it uses competitive reaction of the compound to be measured and of a radioactive-labelled version of this compound with a reagent specific to this compound present in insufficient quantity to combine with the whole of the compound and its labelled version, separation of the bound compound from its non-bound homologue and measurement of the radioactivity concentration in the bound compound, the non-bound compound or both. The radioactive isotope used in the labelled foliate is selenium 75 [fr

Chemical-genetic profile analysis of five inhibitory compounds in yeast

Directory of Open Access Journals (Sweden)

Alamgir Md

2010-08-01

Full Text Available Abstract Background Chemical-genetic profiling of inhibitory compounds can lead to identification of their modes of action. These profiles can help elucidate the complex interactions between small bioactive compounds and the cell machinery, and explain putative gene function(s. Results Colony size reduction was used to investigate the chemical-genetic profile of cycloheximide, 3-amino-1,2,4-triazole, paromomycin, streptomycin and neomycin in the yeast Saccharomyces cerevisiae. These compounds target the process of protein biosynthesis. More than 70,000 strains were analyzed from the array of gene deletion mutant yeast strains. As expected, the overall profiles of the tested compounds were similar, with deletions for genes involved in protein biosynthesis being the major category followed by metabolism. This implies that novel genes involved in protein biosynthesis could be identified from these profiles. Further investigations were carried out to assess the activity of three profiled genes in the process of protein biosynthesis using relative fitness of double mutants and other genetic assays. Conclusion Chemical-genetic profiles provide insight into the molecular mechanism(s of the examined compounds by elucidating their potential primary and secondary cellular target sites. Our follow-up investigations into the activity of three profiled genes in the process of protein biosynthesis provided further evidence concerning the usefulness of chemical-genetic analyses for annotating gene functions. We termed these genes TAE2, TAE3 and TAE4 for translation associated elements 2-4.

Development and Validation of a Precise and Stability Indicating LC Method for the Determination of Benzalkonium Chloride in Pharmaceutical Formulation Using an Experimental Design

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.

Determination of Polar Compounds in Guava Leaves Infusions and Ultrasound Aqueous Extract by HPLC-ESI-MS

Directory of Open Access Journals (Sweden)

Elixabet Díaz-de-Cerio

2015-01-01

Full Text Available Literature lacks publications about polar compounds content in infusion or guava leaves tea. Because of that, a comparison between different times of infusion and a conventional ultrasound aqueous extract was carried out. Several polar compounds have been identified by HPLC-ESI-MS and their antioxidant activity was evaluated by FRAP and ABTS assays. Four different classes of phenolic compounds (gallic and ellagic acid derivatives, flavonols, flavanones, and flavan-3-ols and some benzophenones were determined. The quantification results reported that the order, in terms of concentration of the classes of polar compounds in all samples, was flavonols > flavan-3-ols > gallic and ellagic acid derivatives > benzophenones > flavanones. As expected, the aqueous extract obtained by sonication showed the highest content in the compounds studied. Significative differences were noticed about the different times of infusion and five minutes was the optimal time to obtain the highest content in polar compounds using this culinary method. All the identified compounds, except HHDP isomers and naringenin, were positively correlated with antioxidant activity.

Volatile composition of Merlot red wine and its contribution to the aroma: optimization and validation of analytical method.

Science.gov (United States)

Arcari, Stefany Grützmann; Caliari, Vinicius; Sganzerla, Marla; Godoy, Helena Teixeira

2017-11-01

A methodology for the determination of volatile compounds in red wine using headspace solid phase microextraction (HS-SPME) combined with gas chromatography-ion trap/ mass spectrometry (GC-IT/MS) and flame ionization detector (GC -FID) was developed, validated and applied to a sample of Brazilian red wine. The optimization strategy was conducted using the Plackett-Burman design for variable selection and central composite rotational design (CCRD). The response surface methodology showed that the performance of the extraction of the volatile compounds using divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber is improved with no sample dilution, the addition of 30% NaCl, applying an extraction temperature of 56°C and extraction time of 55min. The qualitative method allowed the extraction and identification of 60 volatile compounds in the sample studied, notably the classes of esters, alcohols, and fatty acids. Furthermore, the method was successfully validated for the quantification of 55 volatile compounds of importance in wines and applied to twelve samples of Merlot red wine from South of Brazil. The calculation of the odor activity value (OAV) showed the most important components of the samples aroma. Ethyl isovalerate, ethyl hexanoate, 1-hexanol, octanoic acid and ethyl cinnamate had the greatest contribution to the aroma of the wines analyzed, which is predominantly fruity with the presence of herbal and fatty odors. Copyright © 2017 Elsevier B.V. All rights reserved.

Predicting chemically-induced skin reactions. Part I: QSAR models of skin sensitization and their application to identify potentially hazardous compounds

Science.gov (United States)

Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

2015-01-01

Repetitive exposure to a chemical agent can induce an immune reaction in inherently susceptible individuals that leads to skin sensitization. Although many chemicals have been reported as skin sensitizers, there have been very few rigorously validated QSAR models with defined applicability domains (AD) that were developed using a large group of chemically diverse compounds. In this study, we have aimed to compile, curate, and integrate the largest publicly available dataset related to chemically-induced skin sensitization, use this data to generate rigorously validated and QSAR models for skin sensitization, and employ these models as a virtual screening tool for identifying putative sensitizers among environmental chemicals. We followed best practices for model building and validation implemented with our predictive QSAR workflow using random forest modeling technique in combination with SiRMS and Dragon descriptors. The Correct Classification Rate (CCR) for QSAR models discriminating sensitizers from non-sensitizers were 71–88% when evaluated on several external validation sets, within a broad AD, with positive (for sensitizers) and negative (for non-sensitizers) predicted rates of 85% and 79% respectively. When compared to the skin sensitization module included in the OECD QSAR toolbox as well as to the skin sensitization model in publicly available VEGA software, our models showed a significantly higher prediction accuracy for the same sets of external compounds as evaluated by Positive Predicted Rate, Negative Predicted Rate, and CCR. These models were applied to identify putative chemical hazards in the ScoreCard database of possible skin or sense organ toxicants as primary candidates for experimental validation. PMID:25560674

Occurrence of cyanazine compounds in groundwater: Degradates more prevalent than the parent compound

Science.gov (United States)

Kolpin, D.W.; Thurman, E.M.; Linhart, S.M.

2001-01-01

A recently developed analytical method using liquid chromatography/mass spectrometry was used to investigate the occurrence of cyanazine and its degradates cyanazine acid (CAC), cyanazine amide (CAM), deethylcyanazine (DEC), and deethylcyanazine acid (DCAC) in groundwater. This research represents some of the earliest data on the occurrence of cyanazine degradates in groundwater. Although cyanazine was infrequently detected in the 64 wells across Iowa sampled in 1999, cyanazine degradates were commonly found during this study. The most frequently detected cyanazine compound was DCAC (32.8%) followed by CAC (29.7%), CAM (17.2%), DEC (3.1%), and cyanazine (3.1%). The frequency of detection for cyanazine or one or more of its degradates (CYTOT) was more than 12-fold over that of cyanazine alone (39.1% for CYTOT versus 3.1% for cyanazine). Of the total measured concentration of cyanazine, only 0.2% was derived from its parent compound - with DCAC (74.1%) and CAC (18.4%) comprising 92.5% of this total. Thus, although DCAC and CAC had similar frequencies of detection, DCAC was generally present in higher concentrations. No concentrations of cyanazine compounds for this study exceeded water-quality criteria for the protection of human health. Only cyanazine, however, has such a criteria established. Nevertheless, because these cyanazine degradates are still chlorinated, they may have similar toxicity as their parent compound - similar to what has been found with the chlorinated degradates of atrazine. Thus, the results of this study documented that data on the degradates for cyanazine are critical for understanding its fate and transport in the hydrologic system. Furthermore, the prevalence of the chlorinated degradates of cyanazine found in groundwater suggests that to accurately determine the overall effect on human health and the environment from cyanazine its degradates should also be considered. In addition, because CYTOT was found in 57.6% of the samples collected

Short-term and long-term earthquake occurrence models for Italy: ETES, ERS and LTST

Directory of Open Access Journals (Sweden)

Maura Murru

2010-11-01

Full Text Available This study describes three earthquake occurrence models as applied to the whole Italian territory, to assess the occurrence probabilities of future (M ≥5.0 earthquakes: two as short-term (24 hour models, and one as long-term (5 and 10 years. The first model for short-term forecasts is a purely stochastic epidemic type earthquake sequence (ETES model. The second short-term model is an epidemic rate-state (ERS forecast based on a model that is physically constrained by the application to the earthquake clustering of the Dieterich rate-state constitutive law. The third forecast is based on a long-term stress transfer (LTST model that considers the perturbations of earthquake probability for interacting faults by static Coulomb stress changes. These models have been submitted to the Collaboratory for the Study of Earthquake Predictability (CSEP for forecast testing for Italy (ETH-Zurich, and they were locked down to test their validity on real data in a future setting starting from August 1, 2009.

Elastic properties of distorted triangular lattice KNiCl3-family compounds

International Nuclear Information System (INIS)

Nishiwaki, Yoichi; Hasegawa, Takumi; Machida, Kenichi; Takeuchi, Yoshio

2006-01-01

In order to discuss the condensation of the K 4 -mode in KNiCl 3 -family compounds, the temperature dependences of the elastic compliances of KNiCl 3 , RbMnBr 3 , RbFeBr 3 , and RbCoBr 3 were measured. In each compound, the temperature dependence of the elastic compliances s 33 showed a sharp discontinuity at the point of structural phase transition from a prototype P6 3 /mmc structure. The structural phase transitions of the KNiCl 3 -family compounds are induced by the condensation of the K 4 -mode at the Brilluoin zone boundary in the P6 3 /mmc structure. When the K 4 -mode is regarded as an order parameter η, the Landau free energy includes coupling term η 2 T 3 , where T 3 is an external stress. The experimental results were interpreted satisfactorily on the basis of a phenomenological Landau theory. (author)

Influence of Al-atoms on the spin fluctuation scattering in R(Co,Al)2 compounds

International Nuclear Information System (INIS)

Duc, N.H.; Hung, D.T.; Kim-Ngan, N.H.; Sechovsky, V.

1992-01-01

The resistivity and magnetisation have been measured for the R(Co 1-x Al x ) 2 compounds with R=Nd, Gd, Tb, Dy, Ho, Er and Lu. For x=0.2 the resistivity enhancement is observed below T c , however, for the compounds with R=Lu-Tb only. The results are discussed in terms of the spin fluctuation scattering and indicate that the enhancement of the spin fluctuation scattering is strongly related to the lattice parameter. (orig.)

Volatile compounds and some physico-chemical properties of pastırma produced with different nitrate levels

Directory of Open Access Journals (Sweden)

Ahmet Akköse

2017-08-01

Full Text Available Objective The aim of the study was to evaluate the effects of different nitrate levels (150, 300, 450, and 600 ppm KNO3 on the volatile compounds and some other properties of pastırma. Methods Pastırma samples were produced under the controlled condition and analyses of volatile compounds, and thiobarbituric acid reactive substances (TBARS as an indicator of lipid oxidation, non-protein nitrogenous matter content as an indicator of proteolysis, color and residual nitrite were carried out on the final product. The profile of volatile compounds of pastırma samples was analyzed by gas chromatography/mass spectrometry using a solid phase microextraction. Results Nitrate level had a significant effect on pH value (p<0.05 and a very significant effect on TBARS value (p<0.01. No significant differences were determined in terms of aw value, non-protein nitrogenous substance content, color and residual nitrite between pastırma groups produced by using different nitrate levels. Nitrate level had a significant (p<0.05 or a very significant (p<0.01 effect on some volatile compounds. It was determined that the amounts and counts of volatile compounds were lower in the 450 and especially 600 ppm nitrate levels than 150 and 300 ppm nitrate levels (p<0.05. While the use of 600 ppm nitrate did not cause an increase in residual nitrite levels, the use of 150 ppm nitrate did not negatively affect the color of pastırma. However, the levels of volatile compounds decreased with an increasing level of nitrate. Conclusion The use of 600 ppm nitrate is not a risk in terms of residual nitrite in pastırma produced under controlled condition, however, this level is not suitable due to decrease in the amount of volatile compounds.

A validation methodology for fault-tolerant clock synchronization

Science.gov (United States)

Johnson, S. C.; Butler, R. W.

1984-01-01

A validation method for the synchronization subsystem of a fault-tolerant computer system is presented. The high reliability requirement of flight crucial systems precludes the use of most traditional validation methods. The method presented utilizes formal design proof to uncover design and coding errors and experimentation to validate the assumptions of the design proof. The experimental method is described and illustrated by validating an experimental implementation of the Software Implemented Fault Tolerance (SIFT) clock synchronization algorithm. The design proof of the algorithm defines the maximum skew between any two nonfaulty clocks in the system in terms of theoretical upper bounds on certain system parameters. The quantile to which each parameter must be estimated is determined by a combinatorial analysis of the system reliability. The parameters are measured by direct and indirect means, and upper bounds are estimated. A nonparametric method based on an asymptotic property of the tail of a distribution is used to estimate the upper bound of a critical system parameter. Although the proof process is very costly, it is extremely valuable when validating the crucial synchronization subsystem.

Valence, magnetism and conduction in the intermediate valence compounds: the case SmB6

International Nuclear Information System (INIS)

Derr, J.

2006-09-01

In some rare earth based compounds, the 4f level is situated so close to the Fermi level that the valence of the compound can become intermediate between two integer values. The so called 'intermediate valence' compound of Samarium hexaboride (SmB 6 ) is one typical example of the exciting physics which can result from this quantum equilibrium between two valence configurations. The first configuration (Sm 2+ ) corresponds to an insulating and non magnetic state whereas the second one (Sm 3+ ) would theoretically give a magnetic and metallic ground state. This dissertation deals with the influence of pressure on this equilibrium. Specific heat measurements under pressure evidenced a new long range magnetic ordering for pressures higher than p c ∼ 10 GPa. On another hand, transport measurements measured for the first time in good conditions of hydrostatics found a reliable and reproducible critical pressure for the insulator to metal transition equal to p c . The phase diagram of SmB 6 is now well known and the observation for the first time of a magnetic anomaly in the high pressure resistivity curves certifies that the onset of the magnetic phase really coincide with the closure of the gap. This change at the critical pressure p c is discussed in a general frame taking into account the Kondo lattice temperature as a key parameter for the renormalization of the wavefunction from one integer configuration to the other whereas the valence itself is still intermediate. This general idea seems to be valid also for other systems studied in this dissertation like SmS or TmSe and could even be valid for more general cases (Ytterbium, Cerium). In the same time, resistivity measurements under uniaxial stress were undertaken. The result is a strong anisotropy effect observed on the pressure dependence of the residual resistivity in the compound SmB 6 . The comparison with the transport under hydrostatic conditions enables us to consider a new idea for the nature of the gap

Short-term toxicity studies with triphenyltin compounds in rats and guinea-pigs

NARCIS (Netherlands)

Verschuuren, H.G.; Kroes, R.; Vink, H.H.; Esch, G.J. van

1966-01-01

Short-term toxicity studies have been carried out in rats and guinea-pigs fed diets containing triphenyltin acetate (TPTA), triphenyltin hydroxide (TPTH) or triethyltin hydroxide (TETH) for 90 days at levels ranging from 0 to 50 ppm. The lowest dietary levels found to retard growth in rats and

Rubber compounding and processing

CSIR Research Space (South Africa)

John, MJ

2014-06-01

Full Text Available This chapter presents an overview on the compounding and processing techniques of natural rubber compounds. The introductory portion deals with different types of rubbers and principles of rubber compounding. The primary and secondary fillers used...

Nitrogen Compounds in Radiation Chemistry

International Nuclear Information System (INIS)

Sims, H.E.; Dey, G.R.; Vaudey, C.E.; Peaucelle, C.; Boucher, J.L.; Toulhoat, N.; Bererd, N.; Koppenol, W.H.; Janata, E.; Dauvois, V.; Durand, D.; Legand, S.; Roujou, J.L.; Doizi, D.; Dannoux, A.; Lamouroux, C.

2009-01-01

Water radiolysis in presence of N 2 is probably the topic the most controversy in the field of water radiolysis. It still exists a strong discrepancy between the different reports of ammonia formation by water radiolysis in presence of N 2 and moreover in absence of oxygen there is no agreement on the formation or not of nitrogen oxide like NO 2 - and NO 3 -. These discrepancies come from multiple sources: - the complexity of the reaction mechanisms where nitrogen is involved - the experimental difficulties - and, the irradiation conditions. The aim of the workshop is to capitalize the knowledge needed to go further in simulations and understanding the problems caused (or not) by the presence of nitrogen / water in the environment of radioactive materials. Implications are evident in terms of corrosion, understanding of biological systems and atmospheric chemistry under radiation. Topics covered include experimental and theoretical approaches, application and fundamental researches: - Nitrate and Ammonia in radiation chemistry in nuclear cycle; - NOx in biological systems and atmospheric chemistry; - Formation of Nitrogen compounds in Nuclear installations; - Nitrogen in future power plant projects (Gen4, ITER...) and large particle accelerators. This document gathers the transparencies available for 7 of the presentations given at this workshop. These are: - H.E SIMS: 'Radiation Chemistry of Nitrogen Compounds in Nuclear Power Plant'; - G.R. DEY: 'Nitrogen Compounds Formation in the Radiolysis of Aqueous Solutions'; - C.E. VAUDEY et al.: 'Radiolytic corrosion of nuclear graphite studied with the dedicated gas irradiation cell of IPNL'; - J.L. BOUCHER: 'Roles and biosynthesis of NO in eukaryotes and prokaryotes'; - W.H. KOPPENOL: 'Chemistry of NOx'; - E. JANATA: 'Yield of OH in N 2 O saturated aqueous solution'; - V. DAUVOIS: 'Analytical strategy for the study of radiolysis gases'

Multi-angle compound imaging

DEFF Research Database (Denmark)

Jespersen, Søren Kragh; Wilhjelm, Jens Erik; Sillesen, Henrik

1998-01-01

This paper reports on a scanning technique, denoted multi-angle compound imaging (MACI), using spatial compounding. The MACI method also contains elements of frequency compounding, as the transmit frequency is lowered for the highest beam angles in order to reduce grating lobes. Compared to conve......This paper reports on a scanning technique, denoted multi-angle compound imaging (MACI), using spatial compounding. The MACI method also contains elements of frequency compounding, as the transmit frequency is lowered for the highest beam angles in order to reduce grating lobes. Compared...... to conventional B-mode imaging MACI offers better defined tissue boundaries and lower variance of the speckle pattern, resulting in an image with reduced random variations. Design and implementation of a compound imaging system is described, images of rubber tubes and porcine aorta are shown and effects...... on visualization are discussed. The speckle reduction is analyzed numerically and the results are found to be in excellent agreement with existing theory. An investigation of detectability of low-contrast lesions shows significant improvements compared to conventional imaging. Finally, possibilities for improving...

Validation of an immortalized human (hBMEC) in vitro blood-brain barrier model.

Science.gov (United States)

Eigenmann, Daniela Elisabeth; Jähne, Evelyn Andrea; Smieško, Martin; Hamburger, Matthias; Oufir, Mouhssin

2016-03-01

We recently established and optimized an immortalized human in vitro blood-brain barrier (BBB) model based on the hBMEC cell line. In the present work, we validated this mono-culture 24-well model with a representative series of drug substances which are known to cross or not to cross the BBB. For each individual compound, a quantitative UHPLC-MS/MS method in Ringer HEPES buffer was developed and validated according to current regulatory guidelines, with respect to selectivity, precision, and reliability. Various biological and analytical challenges were met during method validation, highlighting the importance of careful method development. The positive controls antipyrine, caffeine, diazepam, and propranolol showed mean endothelial permeability coefficients (P e) in the range of 17-70 × 10(-6) cm/s, indicating moderate to high BBB permeability when compared to the barrier integrity marker sodium fluorescein (mean P e 3-5 × 10(-6) cm/s). The negative controls atenolol, cimetidine, and vinblastine showed mean P e values < 10 × 10(-6) cm/s, suggesting low permeability. In silico calculations were in agreement with in vitro data. With the exception of quinidine (P-glycoprotein inhibitor and substrate), BBB permeability of all control compounds was correctly predicted by this new, easy, and fast to set up human in vitro BBB model. Addition of retinoic acid and puromycin did not increase transendothelial electrical resistance (TEER) values of the BBB model.

TDPAC study of complex structure semiconductor compounds

International Nuclear Information System (INIS)

Shitu, J.; Renteria, M.; Massolo, C.P.; Bibiloni, A.G.; Desimoni, J.

1992-01-01

In this paper, a new method for analyzing Time-Differential Perturbed Angular Correlation spectra is presented and applied to study the hyperfine interaction of 100 Rh in the high temperature modification of niobium pentoxide. The measured quadrupole interactions are assigned to about 80% of the radioactive probes replacing niobium atoms in the lattice and about 20% located in perturbed sites. The origin of this perturbation, producing a high frequency component in the measured spectra is discussed and temptatively assigned to remaining radiation damage in the compound. The hyperfine interaction of 111 Cd probes, introduced through thermal diffusion into niobium pentoxide, is also presented. The temperature dependence of the hyperfine parameters in this case is studied in the temperature range RT-800 degrees C. The spectral analyzing method employed allows a direct comparison of experimental data with point charge model calculations and a simultaneous evaluation of the anti-shielding factor β. The obtained values (27 for 100 Rh and 15 for 111 Cd) are discussed in terms of the compound and probe's characteristics

TDPAC study of complex structure semiconductor compounds

International Nuclear Information System (INIS)

Shitu, J.; Renteria, M.; Massolo, C.P.; Bibiloni, A.G.; Desimonni, J.

1992-01-01

In this paper, a new method for analyzing Time-Differential Perturbed Angular Correlation spectra is presented and applied to study the hyperfine interaction of 100 Rh in the high temperature modification of niobium pentoxide. The measured quadrupole interactions are assigned to about 80% of the radioactive probes replacing niobium atoms in the lattice and about 20% located in perturbed sites. The origin of this perturbation, producing a high frequency component in the measured spectra is discussed and temptatively assigned to remaining radiation damage in the compound. The hyperfine interaction of 111 Cd probes, introduced through thermal diffusion into niobium pentoxide, is also presented. The temperature dependence of the hyperfine parameters in this case is studied in the temperature range RT-800 degrees C. The spectral analyzing method employed allows a direct comparison of experimental data with point charge model calculations and a simultaneous evaluation of the antishielding factor β. The obtained values (27 for 100 Rh and 15 for 111 Cd) are discussed in terms of the compound and probe's characteristics

The concept of validation of numerical models for consequence analysis

International Nuclear Information System (INIS)

Borg, Audun; Paulsen Husted, Bjarne; Njå, Ove

2014-01-01

Numerical models such as computational fluid dynamics (CFD) models are increasingly used in life safety studies and other types of analyses to calculate the effects of fire and explosions. The validity of these models is usually established by benchmark testing. This is done to quantitatively measure the agreement between the predictions provided by the model and the real world represented by observations in experiments. This approach assumes that all variables in the real world relevant for the specific study are adequately measured in the experiments and in the predictions made by the model. In this paper the various definitions of validation for CFD models used for hazard prediction are investigated to assess their implication for consequence analysis in a design phase. In other words, how is uncertainty in the prediction of future events reflected in the validation process? The sources of uncertainty are viewed from the perspective of the safety engineer. An example of the use of a CFD model is included to illustrate the assumptions the analyst must make and how these affect the prediction made by the model. The assessments presented in this paper are based on a review of standards and best practice guides for CFD modeling and the documentation from two existing CFD programs. Our main thrust has been to assess how validation work is performed and communicated in practice. We conclude that the concept of validation adopted for numerical models is adequate in terms of model performance. However, it does not address the main sources of uncertainty from the perspective of the safety engineer. Uncertainty in the input quantities describing future events, which are determined by the model user, outweighs the inaccuracies in the model as reported in validation studies. - Highlights: • Examine the basic concept of validation applied to models for consequence analysis. • Review standards and guides for validation of numerical models. • Comparison of the validation

Total and Local Quadratic Indices of the Molecular Pseudograph's Atom Adjacency Matrix: Applications to the Prediction of Physical Properties of Organic Compounds

Directory of Open Access Journals (Sweden)

Yovani Marrero Ponce

2003-08-01

Full Text Available A novel topological approach for obtaining a family of new molecular descriptors is proposed. In this connection, a vector space E (molecular vector space, whose elements are organic molecules, is defined as a “direct sum“ of different ℜi spaces. In this way we can represent molecules having a total of i atoms as elements (vectors of the vector spaces ℜi (i=1, 2, 3,..., n; where n is number of atoms in the molecule. In these spaces the components of the vectors are atomic properties that characterize each kind of atom in particular. The total quadratic indices are based on the calculation of mathematical quadratic forms. These forms are functions of the k-th power of the molecular pseudograph's atom adjacency matrix (M. For simplicity, canonical bases are selected as the quadratic forms' bases. These indices were generalized to “higher analogues“ as number sequences. In addition, this paper also introduces a local approach (local invariant for molecular quadratic indices. This approach is based mainly on the use of a local matrix [Mk(G, FR]. This local matrix is obtained from the k-th power (Mk(G of the atom adjacency matrix M. Mk(G, FR includes the elements of the fragment of interest and those that are connected with it, through paths of length k. Finally, total (and local quadratic indices have been used in QSPR studies of four series of organic compounds. The quantitative models found are significant from a statistical point of view and permit a clear interpretation of the studied properties in terms of the structural features of molecules. External prediction series and cross-validation procedures (leave-one-out and leave-group-out assessed model predictability. The reported method has shown similar results, compared with other topological approaches. The results obtained were the following: a Seven physical properties of 74 normal and branched alkanes (boiling points

Deep inelastic scattering in formalism with wave functions of rest compound system

International Nuclear Information System (INIS)

Sisakyan, A.N.; Kvinikhidze, A.N.; Khvedelidze, A.M.

1987-01-01

One of the most simple examples of interaction of compound systems: deep inelastic scattering of the point particle on hadron is considered. By choosing the compound particle (hadron) rest system the corresponding cross section is expressed in terms of more usual from the view point of nonrelativistic quantum mechanics wave functions of the rest bound state. A new variant of structure functions expansion into a series in terms of the coupling constant is suggested. Each therm of a series due to correct account of the energy conservation law in any order of the perturbation theory possess spectral property. Analysis in QCD shows that in the bound state rest system (P-vector=0) the pulse approximation though satisfies the requirements of scale invariance is insufficient for correct description of elastic limit x Bj →1 by contrast to P Z →∞ system. It means that parton model is equivalent to pulse approximation only in P Z →∞ system. To obtain the leading in asymptotic region x Bj →1 terms account of component interaction in the finite state is necessary. The simplicity and physical evidence of the wave functions are attained due to the seeming complication of calculations according to the perturbation theory

Structural and Electronic Investigations of Complex Intermetallic Compounds

Energy Technology Data Exchange (ETDEWEB)

Ko, Hyunjin [Iowa State Univ., Ames, IA (United States)

2008-01-01

structures of these and related materials. Such calculations allow us to examine various interactions at the atomic scale, interactions which include orbital overlap, two-electron interactions, and Madelung terms. Moreover, these electronic studies also provide links between the angstrom-scale atomic interactions and the macro-scale physical properties, such as magnetism. Over the past few decades, there have been many significant developments toward understanding structure-bonding-property relationships in extended solids in terms of variables including atomic size, valence electron concentration, and electronegativity. However, many simple approaches based on electron counting, e.g., the octet rule, the 18-electron rule, or Wade's rules for boranes, cannot be applied adequately or universally to many of the more complex intermetallic compounds. For intermetallic phases that include late transition metals and post transition main group elements as their constituents, one classification scheme has been developed and effectively applied by using their valence electron count per atom (vec). These compounds are known as Hume-Rothery electron phases, and they have a variety of structure types with vec < 2.0 as shown in Table 1.

Synthesis and characterization of nanometer sized thermoelectric lead-antimony-silver-tellurium compounds and related materials

International Nuclear Information System (INIS)

Petri, Denis

2012-01-01

The present dissertation deals with different variants of synthesis and processing of nanocrystalline composites of various thermoelectric compounds based on lead telluride including LAST-m (AgPb m SbTe m+2 ), LASTT-m-x (AgPb m-x Sn x SbTe m+2 ), LABST-m-x (AgPb m Sb 1-x Bi x Te m+2 ), doped LAST-m and (PbTe) m (M 15 2 Te 3 ) and the characterization thereof. A new route of manufacturing nanocrystalline composites was developed. The so called co-ball milling-route includes the synthesis of bi- or multinary compounds by conventional solid state melting methods followed by combined milling of appropriate amounts in a planetary ball mill; a process related to the widely used mechanical alloying of elemental powders. The as produced powders were shortly annealed for one hour and a.erwards compacted either at room temperature followed by pressureless sintering or combined application of high pressure and elevated temperatures via spark-plasma-sintering or short-term-sintering. The ball milling yielded micron-sized agglomerates consisting of crystallites with diameters ranging from 10 to 50 nm. These crystallites exhibited complicated internal nanostructures severe crystal defects as a consequence of the high energy processing. During short-term annealing some grain coarsening occured and the crystal defects partly healed, which was confirmed by TEM and HRTEM investigations as well as profile analysis of XRD powder pattern. Local EDX-analysis showed different compositions at every point as a consequence of synthesis and decomposition of the compounds. Measurements of thermopower, electrical and thermal conductivity were carried out and the values of the figure of merit ZT and the powerfactor were calculated. In general the compounds exhibited larger thermopower than corresponding bulk materials, which might be attributed to energy filtering of charge carriers at partly oxidized grain boundaries. Due to enhanced phonon scattering at grain boundarys, nanoscopic

Synthesis, biological evaluation and molecular modeling of a novel series of 7-azaindole based tri-heterocyclic compounds as potent CDK2/Cyclin E inhibitors.

Science.gov (United States)

Baltus, Christine B; Jorda, Radek; Marot, Christophe; Berka, Karel; Bazgier, Václav; Kryštof, Vladimír; Prié, Gildas; Viaud-Massuard, Marie-Claude

2016-01-27

From four molecules, inspired by the structural features of fascaplysin, with an interesting potential to inhibit cyclin-dependent kinases (CDKs), we designed a new series of tri-heterocyclic derivatives based on 1H-pyrrolo[2,3-b]pyridine (7-azaindole) and triazole heterocycles. Using a Huisgen type [3 + 2] cycloaddition as the convergent key step, 24 derivatives were synthesized and their biological activities were evaluated. Comparative molecular field analysis (CoMFA), based on three-dimensional quantitative structure-activity relationship (3D-QSAR) studies, was conducted on a series of 30 compounds from the literature with high to low known inhibitory activity towards CDK2/cyclin E and was validated by a test set of 5 compounds giving satisfactory predictive r(2) value of 0.92. Remarkably, it also gave a good prediction of pIC50 for our tri-heterocyclic series which reinforce the validation of this model for the pIC50 prediction of external set compounds. The most promising compound, 43, showed a micro-molar range inhibitory activity against CDK2/cyclin E and also an antiproliferative and proapoptotic activity against a panel of cancer cell lines. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Rapid Reactivation of Deep Subsurface Microbes in the Presence of C-1 Compounds

Directory of Open Access Journals (Sweden)

Pauliina Rajala

2015-02-01

Full Text Available Microorganisms in the deep biosphere are believed to conduct little metabolic activity due to low nutrient availability in these environments. However, destructive penetration to long-isolated bedrock environments during construction of underground waste repositories can lead to increased nutrient availability and potentially affect the long-term stability of the repository systems, Here, we studied how microorganisms present in fracture fluid from a depth of 500 m in Outokumpu, Finland, respond to simple carbon compounds (C-1 compounds in the presence or absence of sulphate as an electron acceptor. C-1 compounds such as methane and methanol are important intermediates in the deep subsurface carbon cycle, and electron acceptors such as sulphate are critical components of oxidation processes. Fracture fluid samples were incubated in vitro with either methane or methanol in the presence or absence of sulphate as an electron acceptor. Metabolic response was measured by staining the microbial cells with fluorescent dyes that indicate metabolic activity and transcriptional response with RT-qPCR. Our results show that deep subsurface microbes exist in dormant states but rapidly reactivate their transcription and respiration systems in the presence of C-1 substrates, particularly methane. Microbial activity was further enhanced by the addition of sulphate as an electron acceptor. Sulphate- and nitrate-reducing microbes were particularly responsive to the addition of C-1 compounds and sulphate. These taxa are common in deep biosphere environments and may be affected by conditions disturbed by bedrock intrusion, as from drilling and excavation for long-term storage of hazardous waste.

Discovery of nonsteroidal 17beta-hydroxysteroid dehydrogenase 1 inhibitors by pharmacophore-based screening of virtual compound libraries.

Science.gov (United States)

Schuster, Daniela; Nashev, Lyubomir G; Kirchmair, Johannes; Laggner, Christian; Wolber, Gerhard; Langer, Thierry; Odermatt, Alex

2008-07-24

17Beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD1) plays a pivotal role in the local synthesis of the most potent estrogen estradiol. Its expression is a prognostic marker for the outcome of patients with breast cancer and inhibition of 17beta-HSD1 is currently under consideration for breast cancer prevention and treatment. We aimed to identify nonsteroidal 17beta-HSD1 inhibitor scaffolds by virtual screening with pharmacophore models built from crystal structures containing steroidal compounds. The most promising model was validated by comparing predicted and experimentally determined inhibitory activities of several flavonoids. Subsequently, a virtual library of nonsteroidal compounds was screened against the 3D pharmacophore. Analysis of 14 selected compounds yielded four that inhibited the activity of human 17beta-HSD1 (IC 50 below 50 microM). Specificity assessment of identified 17beta-HSD1 inhibitors emphasized the importance of including related short-chain dehydrogenase/reductase (SDR) members to analyze off-target effects. Compound 29 displayed at least 10-fold selectivity over the related SDR enzymes tested.

Nuclear Targeting Terms for Engineers and Scientists

Energy Technology Data Exchange (ETDEWEB)

St Ledger, John W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-02-01

The Department of Defense has a methodology for targeting nuclear weapons, and a jargon that is used to communicate between the analysts, planners, aircrews, and missile crews. The typical engineer or scientist in the Department of Energy may not have been exposed to the nuclear weapons targeting terms and methods. This report provides an introduction to the terms and methodologies used for nuclear targeting. Its purpose is to prepare engineers and scientists to participate in wargames, exercises, and discussions with the Department of Defense. Terms such as Circular Error Probable, probability of hit and damage, damage expectancy, and the physical vulnerability system are discussed. Methods for compounding damage from multiple weapons applied to one target are presented.

Nomenclature on an inorganic compound

International Nuclear Information System (INIS)

1998-10-01

This book contains eleven chapters : which mention nomenclature of an inorganic compound with introduction and general principle on nomenclature of compound. It gives the description of grammar for nomenclature such as brackets, diagonal line, asterisk, and affix, element, atom and groups of atom, chemical formula, naming by stoichiometry, solid, neutral molecule compound, ion, a substituent, radical and name of salt, oxo acid and anion on introduction and definition of oxo acid, coordination compound like symbol of stereochemistry , boron and hydrogen compound and related compound.

Fermi surface measurements in actinide metals and compounds

International Nuclear Information System (INIS)

Arko, A.J.; Schirber, J.E.

1978-01-01

The various techniques of measuring Fermi Surface parameters are briefly discussed in terms f application to actinide systems. Particular emphasis is given the dHvA effect. Some general results found in the dHvA studies of actinide compounds are given. The dHvA effect has been measured in α-U and is presented in detail. None of the observed frequencies corresponds to closed surfaces. Results are compared to the calculations of Freeman, Koelling and Watson-Yang where qualitative agreement is observed

Determination of volatile compounds of the first rose oil and the first ...

African Journals Online (AJOL)

Background: Rose water and rose oil are used in the perfume, cosmetic, pharmaceutical and food industries. The determination of volatile compounds in rose oil and rose water obtained from oil-bearing rose is highly important in terms of availability in the industry and in human health. Materials and Methods: Twenty four ...

Optimization of the HS-SPME-GC/MS technique for determining volatile compounds in red wines made from Isabel grapes (Vitis labrusca

Directory of Open Access Journals (Sweden)

Narciza Maria de Oliveira ARCANJO

2015-01-01

Full Text Available AbstractBrazilian wine production is characterized by Vitis labrusca grape varieties, especially the economically important Isabel cultivar, with over 80% of its production destined for table wine production. The objective of this study was to optimize and validate the conditions for extracting volatile compounds from wine with the solid-phase microextraction technique, using the response surface method. Based on the response surface analysis, it can be concluded that the central point values maximize the process of extracting volatile compounds from wine, i.e., an equilibrium time of 15 minutes, an extraction time of 35 minutes, and an extraction temperature of 30 °C. Esters were the most numerous compounds found under these extraction conditions, indicating that wines made from Isabel cultivar grapes are characterized by compounds that confer a fruity aroma; this finding corroborates the scientific literature.

Validating carbonation parameters of alkaline solid wastes via integrated thermal analyses: Principles and applications.

Science.gov (United States)

Pan, Shu-Yuan; Chang, E-E; Kim, Hyunook; Chen, Yi-Hung; Chiang, Pen-Chi

2016-04-15

Accelerated carbonation of alkaline solid wastes is an attractive method for CO2 capture and utilization. However, the evaluation criteria of CaCO3 content in solid wastes and the way to interpret thermal analysis profiles were found to be quite different among the literature. In this investigation, an integrated thermal analyses for determining carbonation parameters in basic oxygen furnace slag (BOFS) were proposed based on thermogravimetric (TG), derivative thermogravimetric (DTG), and differential scanning calorimetry (DSC) analyses. A modified method of TG-DTG interpretation was proposed by considering the consecutive weight loss of sample with 200-900°C because the decomposition of various hydrated compounds caused variances in estimates by using conventional methods of TG interpretation. Different quantities of reference CaCO3 standards, carbonated BOFS samples and synthetic CaCO3/BOFS mixtures were prepared for evaluating the data quality of the modified TG-DTG interpretation, in terms of precision and accuracy. The quantitative results of the modified TG-DTG method were also validated by DSC analysis. In addition, to confirm the TG-DTG results, the evolved gas analysis was performed by mass spectrometer and Fourier transform infrared spectroscopy for detection of the gaseous compounds released during heating. Furthermore, the decomposition kinetics and thermodynamics of CaCO3 in BOFS was evaluated using Arrhenius equation and Kissinger equation. The proposed integrated thermal analyses for determining CaCO3 content in alkaline wastes was precise and accurate, thereby enabling to effectively assess the CO2 capture capacity of alkaline wastes for mineral carbonation. Copyright © 2015 Elsevier B.V. All rights reserved.

Development of a tool dedicated to the evaluation of hydrogen term source for technological Wastes: assumptions, physical models, and validation

Energy Technology Data Exchange (ETDEWEB)

Lamouroux, C. [CEA Saclay, Nuclear Energy Division /DANS, Department of physico-chemistry, 91191 Gif sur yvette (France); Esnouf, S. [CEA Saclay, DSM/IRAMIS/SIS2M/Radiolysis Laboratory , 91191 Gif sur yvette (France); Cochin, F. [Areva NC,recycling BU, DIRP/RDP tour Areva, 92084 Paris La Defense (France)

2013-07-01

In radioactive waste packages hydrogen is generated, in one hand, from the radiolysis of wastes (mainly organic materials) and, in the other hand, from the radiolysis of water content in the cement matrix. In order to assess hydrogen generation 2 tools based on operational models have been developed. One is dedicated to the determination of the hydrogen source term issues from the radiolysis of the wastes: the STORAGE tool (Simulation Tool Of Emission Radiolysis Gas), the other deals with the hydrogen source term gas, produced by radiolysis of the cement matrices (the Damar tool). The approach used by the STORAGE tool for assessing the production rate of radiolysis gases is divided into five steps: 1) Specification of the data packages, in particular, inventories and radiological materials defined for a package medium; 2) Determination of radiochemical yields for the different constituents and the laws of behavior associated, this determination of radiochemical yields is made from the PRELOG database in which radiochemical yields in different irradiation conditions have been compiled; 3) Definition of hypothesis concerning the composition and the distribution of contamination inside the package to allow assessment of the power absorbed by the constituents; 4) Sum-up of all the contributions; And finally, 5) validation calculations by comparison with a reduced sampling of packages. Comparisons with measured values confirm the conservative character of the methodology and give confidence in the safety margins for safety analysis report.

Performance Validity Testing in Neuropsychology: Scientific Basis and Clinical Application-A Brief Review.

Science.gov (United States)

Greher, Michael R; Wodushek, Thomas R

2017-03-01

Performance validity testing refers to neuropsychologists' methodology for determining whether neuropsychological test performances completed in the course of an evaluation are valid (ie, the results of true neurocognitive function) or invalid (ie, overly impacted by the patient's effort/engagement in testing). This determination relies upon the use of either standalone tests designed for this sole purpose, or specific scores/indicators embedded within traditional neuropsychological measures that have demonstrated this utility. In response to a greater appreciation for the critical role that performance validity issues play in neuropsychological testing and the need to measure this variable to the best of our ability, the scientific base for performance validity testing has expanded greatly over the last 20 to 30 years. As such, the majority of current day neuropsychologists in the United States use a variety of measures for the purpose of performance validity testing as part of everyday forensic and clinical practice and address this issue directly in their evaluations. The following is the first article of a 2-part series that will address the evolution of performance validity testing in the field of neuropsychology, both in terms of the science as well as the clinical application of this measurement technique. The second article of this series will review performance validity tests in terms of methods for development of these measures, and maximizing of diagnostic accuracy.

Distribution and retention of inhaled selenium compounds in the rat

International Nuclear Information System (INIS)

Burkstaller, M.A.; Cuddihy, R.G.

1978-01-01

Selenium containing compounds released into the atmosphere during coal combustion are principally of the elemental form or the dioxide. These compounds differ greatly in their chemical properties. Fischer-344 rats were exposed via inhalation to both the dioxide and the red elemental form of selenium. Subsequently, measurements were made of internal absorption, organ distribution and retention, and modes of excretion. A radiotracer, 75 Se, was incorporated into the aerosol to facilitate these measurements. Retention of both aerosols in the total body showed long term components with half lives of 43 and 15 days accounting for 25 to 35% of the initially deposited selenium. Excretion occurred principally by way of urine. For both aerosols, selenium absorbed into the systemic circulation was mainly found in the liver, kidney, blood, gastrointestinal tract and bone

Analytical Procedure Development to Determine Polycyclic Aromatic Compounds in the PM2.5-PM10 Fraction of Atmospheric Aerosols

International Nuclear Information System (INIS)

Barrado, A. I.; Garcia, S.; Perez, R. M.

2013-01-01

This paper presents an optimized and validated analytical methodology for the determination of various polycyclic aromatic compounds in ambient air using liquid chromatography with fluorescence detection. This analysis method was applied to samples obtained during more than one year in an area of Madrid. Selected compounds have included thirteen polycyclic hydrocarbons considered priorities by the EPA, and hydroxylated derivatives, which have been less investigated in air samples by liquid chromatography with fluorescence detection. We have characterized and compared the concentration ranges of compounds identified and studied seasonal and monthly variations. In addition, the techniques have been applied to study multivariate correlations, factor analysis and cluster analysis to extract as much information as possible for interpretation and more complete and accurate characterization of the results and their relationship with meteorological parameters and physicochemical. (Author)

Validation of a Spanish version of the Test Your Memory.

Science.gov (United States)

Ferrero-Arias, J; Turrión-Rojo, M Á

2016-01-01

To validate a Spanish version of the TYM, a self-administered cognitive screening test designed for the detection of Alzheimer's disease and mild cognitive defect. A cross-sectional study was conducted in a neurology outpatient clinic. The TYM was administered to individuals of 50 years o more who came to the clinic for whatever the symptom. Their cognitive state was evaluated regardless of the outcome of TYM. They were categorized into 3 groups: 1) Cognitively normal (739), 2) with mild cognitive impairment (183), 3) with dementia (127). An analysis of items was made and the psychometric properties of the TYM were defined. There was a cross-validation, and the predictive validity of the TYM score, adjusted to the demographic variables, was determined by evaluating their performance in ROC curves. The internal consistency, interobserver reliability, short term and long-term test-retest reliability were adequate. The TYM correlated with the MMSE (r=0.779, Pde Neurología. Published by Elsevier España, S.L.U. All rights reserved.

Enhancing hit identification in Mycobacterium tuberculosis drug discovery using validated dual-event Bayesian models.

Directory of Open Access Journals (Sweden)

Sean Ekins

Full Text Available High-throughput screening (HTS in whole cells is widely pursued to find compounds active against Mycobacterium tuberculosis (Mtb for further development towards new tuberculosis (TB drugs. Hit rates from these screens, usually conducted at 10 to 25 µM concentrations, typically range from less than 1% to the low single digits. New approaches to increase the efficiency of hit identification are urgently needed to learn from past screening data. The pharmaceutical industry has for many years taken advantage of computational approaches to optimize compound libraries for in vitro testing, a practice not fully embraced by academic laboratories in the search for new TB drugs. Adapting these proven approaches, we have recently built and validated Bayesian machine learning models for predicting compounds with activity against Mtb based on publicly available large-scale HTS data from the Tuberculosis Antimicrobial Acquisition Coordinating Facility. We now demonstrate the largest prospective validation to date in which we computationally screened 82,403 molecules with these Bayesian models, assayed a total of 550 molecules in vitro, and identified 124 actives against Mtb. Individual hit rates for the different datasets varied from 15-28%. We have identified several FDA approved and late stage clinical candidate kinase inhibitors with activity against Mtb which may represent starting points for further optimization. The computational models developed herein and the commercially available molecules derived from them are now available to any group pursuing Mtb drug discovery.

Validation of a Dish-Based Semiquantitative Food Questionnaire in Rural Bangladesh

Directory of Open Access Journals (Sweden)

Pi-I. D. Lin

2017-01-01

Full Text Available A locally validated tool was needed to evaluate long-term dietary intake in rural Bangladesh. We assessed the validity of a 42-item dish-based semi-quantitative food frequency questionnaire (FFQ using two 3-day food diaries (FDs. We selected a random subset of 47 families (190 participants from a longitudinal arsenic biomonitoring study in Bangladesh to administer the FFQ. Two 3-day FDs were completed by the female head of the households and we used an adult male equivalent method to estimate the FD for the other participants. Food and nutrient intakes measured by FFQ and FD were compared using Pearson’s and Spearman’s correlation, paired t-test, percent difference, cross-classification, weighted Kappa, and Bland–Altman analysis. Results showed good validity for total energy intake (paired t-test, p < 0.05; percent difference <10%, with no presence of proportional bias (Bland–Altman correlation, p > 0.05. After energy-adjustment and de-attenuation for within-person variation, macronutrient intakes had excellent correlations ranging from 0.55 to 0.70. Validity for micronutrients was mixed. High intraclass correlation coefficients (ICCs were found for most nutrients between the two seasons, except vitamin A. This dish-based FFQ provided adequate validity to assess and rank long-term dietary intake in rural Bangladesh for most food groups and nutrients, and should be useful for studying dietary-disease relationships.

Nanomaterial-Based Sensing and Biosensing of Phenolic Compounds and Related Antioxidant Capacity in Food

Directory of Open Access Journals (Sweden)

Flavio Della Pelle

2018-02-01

Full Text Available Polyphenolic compounds (PCs have received exceptional attention at the end of the past millennium and as much at the beginning of the new one. Undoubtedly, these compounds in foodstuffs provide added value for their well-known health benefits, for their technological role and also marketing. Many efforts have been made to provide simple, effective and user friendly analytical methods for the determination and antioxidant capacity (AOC evaluation of food polyphenols. In a parallel track, over the last twenty years, nanomaterials (NMs have made their entry in the analytical chemistry domain; NMs have, in fact, opened new paths for the development of analytical methods with the common aim to improve analytical performance and sustainability, becoming new tools in quality assurance of food and beverages. The aim of this review is to provide information on the most recent developments of new NMs-based tools and strategies for total polyphenols (TP determination and AOC evaluation in food. In this review optical, electrochemical and bioelectrochemical approaches have been reviewed. The use of nanoparticles, quantum dots, carbon nanomaterials and hybrid materials for the detection of polyphenols is the main subject of the works reported. However, particular attention has been paid to the success of the application in real samples, in addition to the NMs. In particular, the discussion has been focused on methods/devices presenting, in the opinion of the authors, clear advancement in the fields, in terms of simplicity, rapidity and usability. This review aims to demonstrate how the NM-based approaches represent valid alternatives to classical methods for polyphenols analysis, and are mature to be integrated for the rapid quality assessment of food quality in lab or directly in the field.

Raman scattering in transition metal compounds: Titanium and compounds of titanium

Energy Technology Data Exchange (ETDEWEB)

Jimenez, J.; Ederer, D.L.; Shu, T. [Tulane Univ., New Orleans, LA (United States)] [and others

1997-04-01

The transition metal compounds form a very interesting and important set of materials. The diversity arises from the many states of ionization the transition elements may take when forming compounds. This variety provides ample opportunity for a large class of materials to have a vast range of electronic and magnetic properties. The x-ray spectroscopy of the transition elements is especially interesting because they have unfilled d bands that are at the bottom of the conduction band with atomic like structure. This group embarked on the systematic study of transition metal sulfides and oxides. As an example of the type of spectra observed in some of these compounds they have chosen to showcase the L{sub II, III} emission and Raman scattering in some titanium compounds obtained by photon excitation.

Quantitative Determination of Compounds from Akebia quinata by High-Performance Liquid Chromatography

International Nuclear Information System (INIS)

Yen, Nguyen; Thu, Nguyen; Zhao, Bing Tian; Woo, Mi Hee; Min, Byung Sun; Lee, Jae Hyun; Kim, Jeong Ah; Son, Jong Keun; Choi, Jae Sui; Woo, Eun Rhan

2014-01-01

To provide the scientific corroboration of the traditional uses of Akebia quinata (Thunb.) Decne., a detailed analytical examination of A. quinata stems was carried out using a reversed-phase high performance liquid chromatography (RP-HPLC) method coupled to photodiode array detector (PDA) for the simultaneous determination of four phenolic substances; cuneataside D, 2-(3,4-dihydroxyphenyl)ethyl-O-β-D-glucopyranoside, 3-caffeoylquinic acid and calceolarioside B. Particular attention was focused on the main compound, 3-caffeoylquinic acid, which has a range of biological functions. In addition, 2-(3,4-dihydroxyphenyl)ethyl-O-β-D-glucopyranoside was considered as a discernible marker of A. quinata from its easy confuse plants. The contents of compounds 2 and 3 ranged from 0.72 to 2.68 mg/g and from 1.66 to 5.64 mg/g, respectively. The validation data indicated that this HPLC/PDA assay was used successfully to quantify the four phenolic compounds in A. quinata from different locations using relatively simple conditions and procedures. The pattern-recognition analysis data from 53 samples classified them into two groups, allowing discrimination between A. quinata and comparable herbs. The results suggest that the established HPLC/PDA method is suitable for quantitation and pattern-recognition analyses for a quality evaluation of this medicinal herb

Quantitative Determination of Compounds from Akebia quinata by High-Performance Liquid Chromatography

Energy Technology Data Exchange (ETDEWEB)

Yen, Nguyen; Thu, Nguyen; Zhao, Bing Tian; Woo, Mi Hee; Min, Byung Sun [Catholic Univ. of Daegu, Gyeongsan (Korea, Republic of); Lee, Jae Hyun [Dongguk Univ., Yongin (Korea, Republic of); Kim, Jeong Ah [Kyungpook National Univ., Daegu (Korea, Republic of); Son, Jong Keun [Yeungnam Univ., Gyeongsan (Korea, Republic of); Choi, Jae Sui [Pukyung National Univ., Busan (Korea, Republic of); Woo, Eun Rhan [Chosun Univ., Gwangju (Korea, Republic of)

2014-07-15

To provide the scientific corroboration of the traditional uses of Akebia quinata (Thunb.) Decne., a detailed analytical examination of A. quinata stems was carried out using a reversed-phase high performance liquid chromatography (RP-HPLC) method coupled to photodiode array detector (PDA) for the simultaneous determination of four phenolic substances; cuneataside D, 2-(3,4-dihydroxyphenyl)ethyl-O-β-D-glucopyranoside, 3-caffeoylquinic acid and calceolarioside B. Particular attention was focused on the main compound, 3-caffeoylquinic acid, which has a range of biological functions. In addition, 2-(3,4-dihydroxyphenyl)ethyl-O-β-D-glucopyranoside was considered as a discernible marker of A. quinata from its easy confuse plants. The contents of compounds 2 and 3 ranged from 0.72 to 2.68 mg/g and from 1.66 to 5.64 mg/g, respectively. The validation data indicated that this HPLC/PDA assay was used successfully to quantify the four phenolic compounds in A. quinata from different locations using relatively simple conditions and procedures. The pattern-recognition analysis data from 53 samples classified them into two groups, allowing discrimination between A. quinata and comparable herbs. The results suggest that the established HPLC/PDA method is suitable for quantitation and pattern-recognition analyses for a quality evaluation of this medicinal herb.

Prevalence and diagnostic validity of motivational impairments and deficits in visuospatial short-term memory and working memory in ADHD subtypes.

Science.gov (United States)

Dovis, Sebastiaan; Van der Oord, Saskia; Huizenga, Hilde M; Wiers, Reinout W; Prins, Pier J M

2015-05-01

Deficits in working memory (WM) and reinforcement sensitivity are thought to give rise to symptoms in the combined (ADHD-C) and inattentive subtype (ADHD-I) of ADHD. Children with ADHD are especially impaired on visuospatial WM, which is composed of short-term memory (STM) and a central executive. Although deficits in visuospatial WM and reinforcement sensitivity appear characteristic of children with ADHD on a group-level, the prevalence and diagnostic validity of these impairments is still largely unknown. Moreover, studies investigating this did not control for the interaction between motivational impairments and cognitive performance in children with ADHD, and did not differentiate between ADHD subtypes. Visuospatial WM and STM tasks were administered in a standard (feedback-only) and a high-reinforcement (feedback + 10 euros) condition, to 86 children with ADHD-C, 27 children with ADHD-I (restrictive subtype), and 62 typically developing controls (aged 8-12). Reinforcement sensitivity was indexed as the difference in performance between the reinforcement conditions. WM and STM impairments were most prevalent in ADHD-C. In ADHD-I, only WM impairments, not STM impairments, were more prevalent than in controls. Motivational impairments were not common (22% impaired) and equally prevalent in both subtypes. Memory and motivation were found to represent independent neuropsychological domains. Impairment on WM, STM, and/or motivation was associated with more inattention symptoms, medication-use, and lower IQ scores. Similar results were found for analyses of diagnostic validity. The majority of children with ADHD-C is impaired on visuospatial WM. In ADHD-I, STM impairments are not more common than in controls. Within both ADHD subtypes only a minority has an abnormal sensitivity to reinforcement.

CSAHi study-2: Validation of multi-electrode array systems (MEA60/2100) for prediction of drug-induced proarrhythmia using human iPS cell-derived cardiomyocytes: Assessment of reference compounds and comparison with non-clinical studies and clinical information.

Science.gov (United States)

Nozaki, Yumiko; Honda, Yayoi; Watanabe, Hitoshi; Saiki, Shota; Koyabu, Kiyotaka; Itoh, Tetsuji; Nagasawa, Chiho; Nakamori, Chiaki; Nakayama, Chiaki; Iwasaki, Hiroshi; Suzuki, Shinobu; Tanaka, Kohji; Takahashi, Etsushi; Miyamoto, Kaori; Morimura, Kaoru; Yamanishi, Atsuhiro; Endo, Hiroko; Shinozaki, Junko; Nogawa, Hisashi; Shinozawa, Tadahiro; Saito, Fumiyo; Kunimatsu, Takeshi

2017-08-01

With the aim of reconsidering ICH S7B and E14 guidelines, a new in vitro assay system has been subjected to worldwide validation to establish a better prediction platform for potential drug-induced QT prolongation and the consequent TdP in clinical practice. In Japan, CSAHi HEART team has been working on hiPS-CMs in the MEA (hiPS-CMs/MEA) under a standardized protocol and found no inter-facility or lot-to-lot variability for proarrhythmic risk assessment of 7 reference compounds. In this study, we evaluated the responses of hiPS-CMs/MEA to another 31 reference compounds associated with cardiac toxicities, and gene expression to further clarify the electrophysiological characteristics over the course of culture period. The hiPS-CMs/MEA assay accurately predicted reference compounds potential for arrhythmogenesis, and yielded results that showed better correlation with target concentrations of QTc prolongation or TdP in clinical setting than other current in vitro and in vivo assays. Gene expression analyses revealed consistent profiles in all samples within and among the testing facilities. This report would provide CiPA with informative guidance on the use of the hiPS-CMs/MEA assay, and promote the establishment of a new paradigm, beyond conventional in vitro and in vivo assays for cardiac safety assessment of new drugs. Copyright © 2017 Elsevier Inc. All rights reserved.

Bioactive Compounds in Functional Meat Products.

Science.gov (United States)

Pogorzelska-Nowicka, Ewelina; Atanasov, Atanas G; Horbańczuk, Jarosław; Wierzbicka, Agnieszka

2018-01-31

Meat and meat products are a good source of bioactive compounds with positive effect on human health such as vitamins, minerals, peptides or fatty acids. Growing food consumer awareness and intensified global meat producers competition puts pressure on creating new healthier meat products. In order to meet these expectations, producers use supplements with functional properties for animal diet and as direct additives for meat products. In the presented work seven groups of key functional constituents were chosen: (i) fatty acids; (ii) minerals; (iii) vitamins; (iv) plant antioxidants; (v) dietary fibers; (vi) probiotics and (vii) bioactive peptides. Each of them is discussed in term of their impact on human health as well as some quality attributes of the final products.

Enantioselective column coupled electrophoresis employing large bore capillaries hyphenated with tandem mass spectrometry for ultra-trace determination of chiral compounds in complex real samples.

Science.gov (United States)

Piešťanský, Juraj; Maráková, Katarína; Kovaľ, Marián; Havránek, Emil; Mikuš, Peter

2015-12-01

A new multidimensional analytical approach for the ultra-trace determination of target chiral compounds in unpretreated complex real samples was developed in this work. The proposed analytical system provided high orthogonality due to on-line combination of three different methods (separation mechanisms), i.e. (1) isotachophoresis (ITP), (2) chiral capillary zone electrophoresis (chiral CZE), and (3) triple quadrupole mass spectrometry (QqQ MS). The ITP step, performed in a large bore capillary (800 μm), was utilized for the effective sample pretreatment (preconcentration and matrix clean-up) in a large injection volume (1-10 μL) enabling to obtain as low as ca. 80 pg/mL limits of detection for the target enantiomers in urine matrices. In the chiral CZE step, the different chiral selectors (neutral, ionizable, and permanently charged cyclodextrins) and buffer systems were tested in terms of enantioselectivity and influence on the MS detection response. The performance parameters of the optimized ITP - chiral CZE-QqQ MS method were evaluated according to the FDA guidance for bioanalytical method validation. Successful validation and application (enantioselective monitoring of renally eliminated pheniramine and its metabolite in human urine) highlighted great potential of this chiral approach in advanced enantioselective biomedical applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mining collections of compounds with Screening Assistant 2.

Science.gov (United States)

Guilloux, Vincent Le; Arrault, Alban; Colliandre, Lionel; Bourg, Stéphane; Vayer, Philippe; Morin-Allory, Luc

2012-08-31

High-throughput screening assays have become the starting point of many drug discovery programs for large pharmaceutical companies as well as academic organisations. Despite the increasing throughput of screening technologies, the almost infinite chemical space remains out of reach, calling for tools dedicated to the analysis and selection of the compound collections intended to be screened. We present Screening Assistant 2 (SA2), an open-source JAVA software dedicated to the storage and analysis of small to very large chemical libraries. SA2 stores unique molecules in a MySQL database, and encapsulates several chemoinformatics methods, among which: providers management, interactive visualisation, scaffold analysis, diverse subset creation, descriptors calculation, sub-structure / SMART search, similarity search and filtering. We illustrate the use of SA2 by analysing the composition of a database of 15 million compounds collected from 73 providers, in terms of scaffolds, frameworks, and undesired properties as defined by recently proposed HTS SMARTS filters. We also show how the software can be used to create diverse libraries based on existing ones. Screening Assistant 2 is a user-friendly, open-source software that can be used to manage collections of compounds and perform simple to advanced chemoinformatics analyses. Its modular design and growing documentation facilitate the addition of new functionalities, calling for contributions from the community. The software can be downloaded at http://sa2.sourceforge.net/.

The ALICE Software Release Validation cluster

International Nuclear Information System (INIS)

Berzano, D; Krzewicki, M

2015-01-01

One of the most important steps of software lifecycle is Quality Assurance: this process comprehends both automatic tests and manual reviews, and all of them must pass successfully before the software is approved for production. Some tests, such as source code static analysis, are executed on a single dedicated service: in High Energy Physics, a full simulation and reconstruction chain on a distributed computing environment, backed with a sample “golden” dataset, is also necessary for the quality sign off. The ALICE experiment uses dedicated and virtualized computing infrastructures for the Release Validation in order not to taint the production environment (i.e. CVMFS and the Grid) with non-validated software and validation jobs: the ALICE Release Validation cluster is a disposable virtual cluster appliance based on CernVM and the Virtual Analysis Facility, capable of deploying on demand, and with a single command, a dedicated virtual HTCondor cluster with an automatically scalable number of virtual workers on any cloud supporting the standard EC2 interface. Input and output data are externally stored on EOS, and a dedicated CVMFS service is used to provide the software to be validated. We will show how the Release Validation Cluster deployment and disposal are completely transparent for the Release Manager, who simply triggers the validation from the ALICE build system's web interface. CernVM 3, based entirely on CVMFS, permits to boot any snapshot of the operating system in time: we will show how this allows us to certify each ALICE software release for an exact CernVM snapshot, addressing the problem of Long Term Data Preservation by ensuring a consistent environment for software execution and data reprocessing in the future. (paper)

Validation in the Absence of Observed Events.

Science.gov (United States)

Lathrop, John; Ezell, Barry

2016-04-01

This article addresses the problem of validating models in the absence of observed events, in the area of weapons of mass destruction terrorism risk assessment. We address that problem with a broadened definition of "validation," based on stepping "up" a level to considering the reason why decisionmakers seek validation, and from that basis redefine validation as testing how well the model can advise decisionmakers in terrorism risk management decisions. We develop that into two conditions: validation must be based on cues available in the observable world; and it must focus on what can be done to affect that observable world, i.e., risk management. That leads to two foci: (1) the real-world risk generating process, and (2) best use of available data. Based on our experience with nine WMD terrorism risk assessment models, we then describe three best use of available data pitfalls: SME confidence bias, lack of SME cross-referencing, and problematic initiation rates. Those two foci and three pitfalls provide a basis from which we define validation in this context in terms of four tests--Does the model: … capture initiation? … capture the sequence of events by which attack scenarios unfold? … consider unanticipated scenarios? … consider alternative causal chains? Finally, we corroborate our approach against three validation tests from the DOD literature: Is the model a correct representation of the process to be simulated? To what degree are the model results comparable to the real world? Over what range of inputs are the model results useful? © 2015 Society for Risk Analysis.

Antioxidant Phenolic Compounds from Pu-erh Tea

Directory of Open Access Journals (Sweden)

Shu Shan Du

2012-11-01

Full Text Available Eight compounds were isolated from the water extract of Pu-erh tea and their structures were elucidated by NMR and MS as gallic acid (1, (+-catechin (2, (−-epicatechin (3, (−-epicatechin-3-O-gallate (4, (−-epigallocatechin-3-O-gallate (5, (−-epiafzelechin- 3-O-gallate (6, kaempferol (7, and quercetin (8. Their in vitro antioxidant activities were assessed by the DPPH and ABTS scavenging methods with microplate assays. The relative order of DPPH scavenging capacity for these compounds was compound 8 > compound 7 > compound 1 > compound 6 > compound 4 ≈ compound 5 > compound 2 > VC (reference > compound 3, and that of ABTS scavenging capacity was compound 1 > compound 2 > compound 7 ≈ compound 8 > compound 6 > compound 5 > compound 4 > VC (reference > compound 3. The results showed that these phenolic compounds contributed to the antioxidant activity of Pu-erh tea.

Genetic toxicology of metal compounds. I. Induction of lambda prophage in E coli WP2/sub s/(lambda)

Energy Technology Data Exchange (ETDEWEB)

Rossman, T.G.; Molina, M.; Meyer, L.W.

1984-01-01

A number of metal compounds have been shown to be human carcinogens. Others, while not proven human carcinogens, are able to cause tumors in laboratory animals. Short-term bacterial assays for genotoxic effects have not been successful in predicting the carcinogenicity of metal compounds. The authors report here the ability of some metal compounds to cause the induction of lambda prophage in E coli WP2/sub s/(lambda). By far the strongest inducing ability was observed with K/sub 2/CrO/sub 4/, followed by Pb(NO/sub 3/)/sub 2/ > Ni(OOCCH/sub 3/)/sub 2/ > CrCl/sub 2/ > NaWO/sub 4/ > Na/sub 2/MoO/sub 4/ > KMnO/sub 4/. With the exception of chromate, long-term exposures in a narrow, subtoxic dose range were required in order to demonstrate phage induction. A new microtiter assay for lambda prophage induction, which incorporates these features, is described. This system also was able to detect very small amounts of organic carcinogens.

Global simulation of aromatic volatile organic compounds in the atmosphere

Science.gov (United States)

Cabrera Perez, David; Taraborrelli, Domenico; Pozzer, Andrea

2015-04-01

Among the large number of chemical compounds in the atmosphere, the organic group plays a key role in the tropospheric chemistry. Specifically the subgroup called aromatics is of great interest. Aromatics are the predominant trace gases in urban areas due to high emissions, primarily by vehicle exhausts and fuel evaporation. They are also present in areas where biofuel is used (i.e residential wood burning). Emissions of aromatic compounds are a substantial fraction of the total emissions of the volatile organic compounds (VOC). Impact of aromatics on human health is very important, as they do not only contribute to the ozone formation in the urban environment, but they are also highly toxic themselves, especially in the case of benzene which is able to trigger a range of illness under long exposure, and of nitro-phenols which cause detrimental for humans and vegetation even at very low concentrations. The aim of this work is to assess the atmospheric impacts of aromatic compounds on the global scale. The main goals are: lifetime and budget estimation, mixing ratios distribution, net effect on ozone production and OH loss for the most emitted aromatic compounds (benzene, toluene, xylenes, ethylbenzene, styrene and trimethylbenzenes). For this purpose, we use the numerical chemistry and climate simulation ECHAM/MESSy Atmospheric Chemistry (EMAC) model to build the global atmospheric budget for the most emitted and predominant aromatic compounds in the atmosphere. A set of emissions was prepared in order to include biomass burning, vegetation and anthropogenic sources of aromatics into the model. A chemical mechanism based on the Master Chemical Mechanism (MCM) was developed to describe the chemical oxidation in the gas phase of these aromatic compounds. MCM have been reduced in terms of number of chemical equation and species in order to make it affordable in a 3D model. Additionally other features have been added, for instance the production of HONO via ortho

Alloy Design Data Generated for B2-Ordered Compounds

Science.gov (United States)

Noebe, Ronald D.; Bozzolo, Guillermo; Abel, Phillip B.

2003-01-01

Developing alloys based on ordered compounds is significantly more complicated than developing designs based on disordered materials. In ordered compounds, the major constituent elements reside on particular sublattices. Therefore, the addition of a ternary element to a binary-ordered compound is complicated by the manner in which the ternary addition is made (at the expense of which binary component). When ternary additions are substituted for the wrong constituent, the physical and mechanical properties usually degrade. In some cases the resulting degradation in properties can be quite severe. For example, adding alloying additions to NiAl in the wrong combination (i.e., alloying additions that prefer the Al sublattice but are added at the expense of Ni) will severely embrittle the alloy to the point that it can literally fall apart during processing on cooling from the molten state. Consequently, alloying additions that strongly prefer one sublattice over another should always be added at the expense of that component during alloy development. Elements that have a very weak preference for a sublattice can usually be safely added at the expense of either element and will accommodate any deviation from stoichiometry by filling in for the deficient component. Unfortunately, this type of information is not known beforehand for most ordered systems. Therefore, a computational survey study, using a recently developed quantum approximate method, was undertaken at the NASA Glenn Research Center to determine the preferred site occupancy of ternary alloying additions to 12 different B2-ordered compounds including NiAl, FeAl, CoAl, CoFe, CoHf, CoTi, FeTi, RuAl, RuSi, RuHf, RuTi, and RuZr. Some of these compounds are potential high temperature structural alloys; others are used in thin-film magnetic and other electronic applications. The results are summarized. The italicized elements represent the previous sum total alloying information known and verify the computational

Partial purification of endogenous digitalis-like compound(s) in cord blood

Energy Technology Data Exchange (ETDEWEB)

Balzan, S.; Ghione, S.; Biver, P.; Gazzetti, P.; Montali, U. (C.N.R. Institute of Clinical Physiology, Pisa (Italy))

1991-02-01

Increasing evidence indicates the presence of endogenous digitalis-like compound(s) in human body fluids. In this preliminary report, we describe a study of the partial purification by HPLC of these compounds in the plasma of neonates (who have particularly high concentrations of this substance) and adults. Plasma samples from neonates (cord blood) and adults, lyophilized and extracted with methanol, were applied on a 300 x 3.9 mm C18 Nova Pak column and eluted with a mobile phase of acetonitrile/methanol/water (17/17/66 or 14/14/72 by vol) and, after 30 min, with 100% methanol. We assayed eluted fractions for inhibitory activity of 86Rb uptake and for digoxin-like immunoreactivity. The elution profile revealed a first peak of inhibitory activity of 86Rb uptake at the beginning of the chromatography; another peak was eluted with the 100% methanol. The two peaks also cross-reacted with antidigoxin antibodies. Because the second peak could possibly reflect the nonspecific interference of various lipophilic compounds, we focused our attention on the first peak. For these fractions dose-response curves for 86Rb uptake and for displacement of digoxin were parallel, respectively, to those of ouabain and digoxin, suggesting similarities of digoxin-like immunoreactive substance to cardiac glycosides. Similar chromatographic profiles were also obtained for plasma from adults, suggesting that the endogenous glycoside-like compound(s) in the neonate may be the same as those in the adult.

Polarographic validation of chemical speciation models

International Nuclear Information System (INIS)

Duffield, J.R.; Jarratt, J.A.

2001-01-01

It is well established that the chemical speciation of an element in a given matrix, or system of matrices, is of fundamental importance in controlling the transport behaviour of the element. Therefore, to accurately understand and predict the transport of elements and compounds in the environment it is a requirement that both the identities and concentrations of trace element physico-chemical forms can be ascertained. These twin requirements present the analytical scientist with considerable challenges given the labile equilibria, the range of time scales (from nanoseconds to years) and the range of concentrations (ultra-trace to macro) that may be involved. As a result of this analytical variability, chemical equilibrium modelling has become recognised as an important predictive tool in chemical speciation analysis. However, this technique requires firm underpinning by the use of complementary experimental techniques for the validation of the predictions made. The work reported here has been undertaken with the primary aim of investigating possible methodologies that can be used for the validation of chemical speciation models. However, in approaching this aim, direct chemical speciation analyses have been made in their own right. Results will be reported and analysed for the iron(II)/iron(III)-citrate proton system (pH 2 to 10; total [Fe] = 3 mmol dm -3 ; total [citrate 3- ] 10 mmol dm -3 ) in which equilibrium constants have been determined using glass electrode potentiometry, speciation is predicted using the PHREEQE computer code, and validation of predictions is achieved by determination of iron complexation and redox state with associated concentrations. (authors)

Content validation of a Danish version of "The McGill Ingestive Skills Assessment" for dysphagia management.

Science.gov (United States)

Hansen, Tina; Lambert, Heather C; Faber, Jens

2011-12-01

This study addresses the first steps in the cross-cultural adaptation of a Danish version of the McGill Ingestive Skills Assessment (MISA), which quantifies eating and drinking abilities by scoring a meal observation. The original Canadian MISA was translated and adapted into Danish (MISA-DK). For content validation of the MISA-DK, a judgemental quantification process was applied using 13 experts. Thereafter, the MISA-DK was pilot tested by 16 occupational therapists. Finally, the MISA-DK was linked to the International Classification of Functioning, Disability and Health (ICF). Content validity of 43 items was found for 93% in terms of adequacy, 67% in terms of clarity of item description, 86% in terms of clarity of score descriptions, and 93% in terms of relevance. Thirteen of 14 sections of the instruction manual and score sheet were content valid. In light of these results, a revised MISA-DK was produced for the pilot test, which then found content validity for all sections and 98% of the items. The ICF linking resulted in 41 ICF-categories, which may reflect the complexity of eating and drinking as well as a multidimensional structure of the MISA-DK. In conclusion, the MISA-DK is prepared for psychometric testing using classical as well as modern test theory.

Exoproteome and Secretome Derived Broad Spectrum Novel Drug and Vaccine Candidates in Vibrio cholerae Targeted by Piper betel Derived Compounds

Science.gov (United States)

Barh, Debmalya; Barve, Neha; Gupta, Krishnakant; Chandra, Sudha; Jain, Neha; Tiwari, Sandeep; Leon-Sicairos, Nidia; Canizalez-Roman, Adrian; Rodrigues dos Santos, Anderson; Hassan, Syed Shah; Almeida, Síntia; Thiago Jucá Ramos, Rommel; Augusto Carvalho de Abreu, Vinicius; Ribeiro Carneiro, Adriana; de Castro Soares, Siomar; Luiz de Paula Castro, Thiago; Miyoshi, Anderson; Silva, Artur; Kumar, Anil; Narayan Misra, Amarendra; Blum, Kenneth; Braverman, Eric R.; Azevedo, Vasco

2013-01-01

Vibrio cholerae is the causal organism of the cholera epidemic, which is mostly prevalent in developing and underdeveloped countries. However, incidences of cholera in developed countries are also alarming. Because of the emergence of new drug-resistant strains, even though several generic drugs and vaccines have been developed over time, Vibrio infections remain a global health problem that appeals for the development of novel drugs and vaccines against the pathogen. Here, applying comparative proteomic and reverse vaccinology approaches to the exoproteome and secretome of the pathogen, we have identified three candidate targets (ompU, uppP and yajC) for most of the pathogenic Vibrio strains. Two targets (uppP and yajC) are novel to Vibrio, and two targets (uppP and ompU) can be used to develop both drugs and vaccines (dual targets) against broad spectrum Vibrio serotypes. Using our novel computational approach, we have identified three peptide vaccine candidates that have high potential to induce both B- and T-cell-mediated immune responses from our identified two dual targets. These two targets were modeled and subjected to virtual screening against natural compounds derived from Piper betel. Seven compounds were identified first time from Piper betel to be highly effective to render the function of these targets to identify them as emerging potential drugs against Vibrio. Our preliminary validation suggests that these identified peptide vaccines and betel compounds are highly effective against Vibrio cholerae. Currently we are exhaustively validating these targets, candidate peptide vaccines, and betel derived lead compounds against a number of Vibrio species. PMID:23382822

Exoproteome and secretome derived broad spectrum novel drug and vaccine candidates in Vibrio cholerae targeted by Piper betel derived compounds.

Directory of Open Access Journals (Sweden)

Debmalya Barh

Full Text Available Vibrio cholerae is the causal organism of the cholera epidemic, which is mostly prevalent in developing and underdeveloped countries. However, incidences of cholera in developed countries are also alarming. Because of the emergence of new drug-resistant strains, even though several generic drugs and vaccines have been developed over time, Vibrio infections remain a global health problem that appeals for the development of novel drugs and vaccines against the pathogen. Here, applying comparative proteomic and reverse vaccinology approaches to the exoproteome and secretome of the pathogen, we have identified three candidate targets (ompU, uppP and yajC for most of the pathogenic Vibrio strains. Two targets (uppP and yajC are novel to Vibrio, and two targets (uppP and ompU can be used to develop both drugs and vaccines (dual targets against broad spectrum Vibrio serotypes. Using our novel computational approach, we have identified three peptide vaccine candidates that have high potential to induce both B- and T-cell-mediated immune responses from our identified two dual targets. These two targets were modeled and subjected to virtual screening against natural compounds derived from Piper betel. Seven compounds were identified first time from Piper betel to be highly effective to render the function of these targets to identify them as emerging potential drugs against Vibrio. Our preliminary validation suggests that these identified peptide vaccines and betel compounds are highly effective against Vibrio cholerae. Currently we are exhaustively validating these targets, candidate peptide vaccines, and betel derived lead compounds against a number of Vibrio species.

Development and Validation of WebQuests in Teaching Epics

Directory of Open Access Journals (Sweden)

Ronald Candy Santos Lasaten

2017-05-01

Full Text Available Using the Research Development (R&D methodology, the study aimed to develop and validate WebQuests which can be used in literature subjects, particularly in the tertiary level to address the need of literature teachers for pedagogy in the teaching of epic s. The development of the Web Quests was anchored on the Theory of Constructivism. Two groups of experts validated the Web Quests – the literature experts and the ICT experts. The Content Validation Checklist, used by the literature experts, was utilized t o evaluate the content of the Web Quests. Meanwhile, the Rubric for Evaluating Web Quests, used by the ICT experts, was utilized to evaluate the design characteristics of the Web Quests. Computed weighted means using range interval of point scores were emp loyed to treat the data gathered from the evaluation conducted by both group of experts. The Web Quests developed contain five major parts which include: 1 introduction; 2 task; 3 process; 4 evaluation; and 5 conclusion. Based on the findings, the con tent of the Web Quests developed are valid in terms of objectives, activities and instructional characteristics. Likewise, the design characteristics of the Web Quests are excellent in terms of introductions, tasks, processes, resources, evaluations, concl usions and overall designs. Thus, the Web Quests developed are acceptable and can be utilized as instructional materials by literature teachers in the teaching of epics.

Use of visible and near-infrared spectroscopy for predicting antioxidant compounds in summer squash (Cucurbita pepo ssp pepo).

Science.gov (United States)

Blanco-Díaz, María Teresa; Del Río-Celestino, Mercedes; Martínez-Valdivieso, Damián; Font, Rafael

2014-12-01

The food industry and plant breeding programmes require fast, clean and low-cost screening techniques for nutritional compounds determination in food matrices. This is the first report on the study of the potential of near-infrared spectroscopy (NIRS) for the prediction of antioxidant compounds in summer squash tissues collected since 2009-2012. Modified partial least-squares (MPLS) regression was used to correlate spectral information and the different antioxidant compounds in the samples. The coefficients of determination in the external validation (r(2)ev) obtained were for ascorbic acid (0.77 and 0.86), chlorophyll a (0.79 and 0.66), chlorophyll b (0.86 and 0.79) and total phenolic compounds (0.65 and 0.68) in exocarp and mesocarp tissues, respectively, supporting that NIRS is able to predict in a rapid way these components for screening purposes. Major wavelengths influencing the calibration equations showed that chromophores as well as fibre components of the fruits highly participated in developing the NIR equations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Optimization of ultrasound-assisted extraction (UAE) of phenolic compounds from olive cake.

Science.gov (United States)

Mojerlou, Zohreh; Elhamirad, Amirhhossein

2018-03-01

The use of ultrasound in ultrasound-assisted extraction (UAE) is one of the main applications of this technology in food industry. This study aimed to optimize UAE conditions for olive cake extract (OCE) through response surface methodology (RSM). The optimal UAE conditions were obtained with extraction temperature of 56 °C, extraction time of 3 min, duty cycle of 0.6 s, and solid to solvent ratio of 3.6%. At the optimum conditions, the total phenolic compounds (TPC) content and antioxidant activity (AA) were measured 4.04 mg/g and 68.9%, respectively. The linear term of temperature had the most effect on TPC content and AA of OCE prepared by UAE. Protocatechuic acid and cinnamic acid were characterized as the highest (19.5%) and lowest (1.6%) phenolic compound measured in OCE extracted by UAE. This research revealed that UAE is an effective method to extract phenolic compounds from olive cake. RSM successfully optimized UAE conditions for OCE.

Scalar eletrodynamics in three dimensions with topological mass terms

International Nuclear Information System (INIS)

Mello, E.R.B. de.

1986-01-01

The interaction between a charged scalar field and a gauge field in a three-dimensional space-time is studied. The topological mass term (the Chern-Simons term) is added to the system and it is investigated how this term, odd by P and Τ symmetry, modifies the corrections to the propagators and vertices of this theory. These corrections are obtained to order e 2 in perturbation theory. In the correction of the linear vertex a new type term arises. Although this term, which comes from the topological one, presents and abnormal parity, the Ward's identity is still valid. (Author) [pt

Scalar electrodynamics in three dimensions with topological man terms

International Nuclear Information System (INIS)

Mello, E.R.B. de

1987-01-01

The interaction between a charged scalar field and a gauge field in a three-dimensional space-time is studied. The topological mass term (the Chern-Simons term) is added to the system and it is investigated how this term, odd by P and T symmetry, modified the corrections to the propagators and vertices of this theory. These corrections are obtained to order e 2 in pertubation theory. In the correction of the linear vertex a new type of term arises. Although this new term, which comes from the topological one, presents an abnormal parity, Ward's identity is still valid. (Author) [pt

Sizing and scaling requirements of a large-scale physical model for code validation

International Nuclear Information System (INIS)

Khaleel, R.; Legore, T.

1990-01-01

Model validation is an important consideration in application of a code for performance assessment and therefore in assessing the long-term behavior of the engineered and natural barriers of a geologic repository. Scaling considerations relevant to porous media flow are reviewed. An analysis approach is presented for determining the sizing requirements of a large-scale, hydrology physical model. The physical model will be used to validate performance assessment codes that evaluate the long-term behavior of the repository isolation system. Numerical simulation results for sizing requirements are presented for a porous medium model in which the media properties are spatially uncorrelated

Sources of endocrine-disrupting compounds in North Carolina waterways: a geographic information systems approach

Science.gov (United States)

Sackett, Dana K.; Pow, Crystal Lee; Rubino, Matthew J.; Aday, D.D.; Cope, W. Gregory; Kullman, Seth W.; Rice, J.A.; Kwak, Thomas J.; Law, L.M.

2015-01-01

The presence of endocrine-disrupting compounds (EDCs), particularly estrogenic compounds, in the environment has drawn public attention across the globe, yet a clear understanding of the extent and distribution of estrogenic EDCs in surface waters and their relationship to potential sources is lacking. The objective of the present study was to identify and examine the potential input of estrogenic EDC sources in North Carolina water bodies using a geographic information system (GIS) mapping and analysis approach. Existing data from state and federal agencies were used to create point and nonpoint source maps depicting the cumulative contribution of potential sources of estrogenic EDCs to North Carolina surface waters. Water was collected from 33 sites (12 associated with potential point sources, 12 associated with potential nonpoint sources, and 9 reference), to validate the predictive results of the GIS analysis. Estrogenicity (measured as 17β-estradiol equivalence) ranged from 0.06 ng/L to 56.9 ng/L. However, the majority of sites (88%) had water 17β-estradiol concentrations below 1 ng/L. Sites associated with point and nonpoint sources had significantly higher 17β-estradiol levels than reference sites. The results suggested that water 17β-estradiol was reflective of GIS predictions, confirming the relevance of landscape-level influences on water quality and validating the GIS approach to characterize such relationships.

Quantum criticality in He3 bi-layers and heavy fermion compounds

International Nuclear Information System (INIS)

Benlagra, A.

2009-11-01

Despite intense experimental as well as theoretical efforts the understanding of physical phenomena peculiar to heavy fermion compounds remains one of the major problems in condensed matter physics; this research thesis considers the recently proposed theoretical approaches to describe the critical regime properties. This approach is based on the following idea: critical modes which are responsible for this regime are non-magnetic and are associated to the destruction of the Kondo effect between localized magnetic impurities and travelling conduction electrons at the quantum critical point. The author derives an analytic expression for the free energy within this model by using the Luttinger-Ward functional approach within the frame of the Eliashberg theory. The obtained expressions are transparently including the effect of critical fluctuations, integrated in a self-coherent way. The behaviour of different thermodynamic quantities is then deduced from these expressions. The result is compared with recent experiments on heavy fermion compounds as well as on a Helium-3 bilayer system adsorbed on graphite substrate in order to test the validity of such a model. Strengths and drawbacks of the model are outlined

Organotypic Culture of Breast Tumor Explants as a Multicellular System for the Screening of Natural Compounds with Antineoplastic Potential

Directory of Open Access Journals (Sweden)

Irma Edith Carranza-Torres

2015-01-01

Full Text Available Breast cancer is the leading cause of death in women worldwide. The search for novel compounds with antitumor activity, with less adverse effects and higher efficacy, and the development of methods to evaluate their toxicity is an area of ​​intense research. In this study we implemented the preparation and culture of breast tumor explants, which were obtained from precision-cut breast tumor slices. In order to validate the model we are proposing to screen antineoplastic effect of natural compounds, we selected caffeic acid, ursolic acid, and rosmarinic acid. Using the Krumdieck tissue slicer, precision-cut tissue slices were prepared from breast cancer samples; from these slices, 4 mm explants were obtained and incubated with the selected compounds. Viability was assessed by Alamar Blue assay, LDH release, and histopathological criteria. Results showed that the viability of the explants cultured in the presence of paclitaxel (positive control decreased significantly (P<0.05; however, tumor samples responded differently to each compound. When the explants were coincubated with paclitaxel and compounds, a synergic effect was observed. This study shows that ex vivo culture of breast cancer explants offers a suitable alternative model for evaluating natural or synthetic compounds with antitumor properties within the complex microenvironment of the tumor.

Investigations on organogermanium compounds XII. Reactions of trialkylgermylalkalimetal compounds in hexamethylphosphoric triamide (HMPT) with some inorganic and organic compounds

NARCIS (Netherlands)

Bulten, E.J.; Noltes, J.G.

1971-01-01

Trialkylgermyl alkali metal compounds in HMPT have been found to be highly reactive nucleophiles. Reactions with some inorganic and organic compounds, such as oxygen, carbon dioxide, inorganic and orgaanic halides, aldehydes, ketones, epoxides and lactones are described. Several new

Converting a C-130 Hercules into a Compound Helicopter: A Conceptual Design Study

Science.gov (United States)

Kottapalli, Anjaney P.; Harris, Franklin D.

2010-01-01

This study presents the performance and weight changes for a Compound C-130 as compared to the Baseline C-130H Hercules, using NDARC as the primary analysis tool. First, the C-130H was modeled within NDARC, from which performance at various conditions and a parametric weight statement were generated. Then, the C-130H NDARC file was modified to represent the Compound C-130, which was then put through the same performance analysis as the C-130H. A parametric weight statement was also calculated for the Compound C-130, which allowed for comparison to the C-130H. As part of the modeling of the Compound C-130, a Rotor Design Spreadsheet was created that would allow the direct calculation of the weight of the main rotors being added. Using composite materials led to considerable weight savings for both the rotor system and the hub weights. These weight savings are reflected in the NDARC Technology Factors which were determined to be 0.71 and 0.5 for the rotor blades and the hub/hinge system, respectively. Such Technology Factors suggest that using composites for other components could drastically lighten the Operating Empty Weight of the aircraft. The weight statements show the weights for each of the components on each aircraft. It is quite evident that the Compound C-130 has a higher Operating Empty Weight due to the addition of the two main rotors and a drive system to connect each engine group on the wing tips. Upon further analysis, the main weight driver is the drive system. While the main rotor/hub/hinge weight increase is to be expected, the weight increase due to the transmission drive and gear boxes are cause for concern. Unless a method can be found of reducing the weight of the drive system, the weight penalty makes the Compound a C-130 an inefficient aircraft in terms of payload/fuel capacity. Possible solutions are either off-loading some of the power requirements through the drive system or using composite materials in the construction of the drive system

Low-temperature heat-capacity study of the U6X (XequivalentMn, Fe, Co, Ni) compounds

International Nuclear Information System (INIS)

Yang, K.N.; Maple, M.B.; DeLong, L.E.; Huber, J.G.; Junod, A.

1989-01-01

Measurements of the superconducting- and normal-state heat capacity of U 6 X (XequivalentMn, Fe, Co, Ni) compounds have been performed over a temperature range 1 Kapprox. 6 X compounds have strong renormalizations of the free-carrier effective mass m/sup */ in the range 10m/sub e/approx. 6 X heat capacities suggest the presence of high densities of low-energy excitations of undetermined nature. The results are analyzed in terms of models appropriate to heavy-fermion liquids, and anisotropic or strong-coupled superconductors. The U 6 X compounds form a link between relatively low-m/sup */, high-transition-temperature A15 compounds and the more extreme examples of heavy-fermion superconductors such as UBe/sub 13/, UPt 3 , and CeCuSi 2 for which m/sup */∼10 2 m/sub e/. .AE

Static Validation of Security Protocols

DEFF Research Database (Denmark)

Bodei, Chiara; Buchholtz, Mikael; Degano, P.

2005-01-01

We methodically expand protocol narrations into terms of a process algebra in order to specify some of the checks that need to be made in a protocol. We then apply static analysis technology to develop an automatic validation procedure for protocols. Finally, we demonstrate that these techniques ...... suffice to identify several authentication flaws in symmetric and asymmetric key protocols such as Needham-Schroeder symmetric key, Otway-Rees, Yahalom, Andrew secure RPC, Needham-Schroeder asymmetric key, and Beller-Chang-Yacobi MSR...

VALIDITY OF THE EMOTIONAL INTELLIGENCE SCALE FOR USE IN SPORT

Directory of Open Access Journals (Sweden)

Andrew M. Lane

2009-06-01

Full Text Available This study investigated the factorial validity of the 33-item self-rated Emotional Intelligence Scale (EIS: Schutte et al., 1998 for use with athletes. In stage 1, content validity of the EIS was assessed by a panel of experts (n = 9. Items were evaluated in terms of whether they assessed EI related to oneself and EI focused on others. Content validity further examined items in terms of awareness, regulation, and utilization of emotions. Content validity results indicated items describe 6-factors: appraisal of own emotions, regulation of own emotions, utilization of own emotions, optimism, social skills, and appraisal of others emotions. Results highlighted 13-items which make no direct reference to emotional experiences, and therefore, it is questionable whether such items should be retained. Stage 2 tested two competing models: a single factor model, which is the typical way researchers use the EIS and the 5-factor model (optimism was discarded as it become a single-item scale fiolliwng stage 1 identified in stage 1. Confirmatory factor analysis (CFA results on EIS data from 1,681 athletes demonstrated unacceptable fit indices for the 33-item single factor model and acceptable fit indices for the 6-factor model. Data were re-analyzed after removing the 13-items lacking emotional content, and CFA results indicate partial support for single factor model, and further support for a five-factor model (optimism was discarded as a factor during item removal. Despite encouraging results for a reduced item version of the EIS, we suggest further validation work is needed

The Management Advisory Committee of the Inspection Validation Centre - fifth report

International Nuclear Information System (INIS)

1988-07-01

The Management Advisory Committee of the Inspection Validation Centre (IVC/MAC) was set up by the Chairman of the UKAEA early in 1983 with terms of reference to review the policy, scope, procedure and operation of the Inspection Validation Centre, to supervise its operation and to advise and report to the UKAEA appropriately. The Inspection Validation Centre (IVC) has been established at the UKAEA Northern Research Laboratories, Risley for the purpose of validating the procedures, equipment and personnel proposed by the CEGB for use in the ultrasonic inspection at various stages of the fabrication, erection and operation of the CEGB's PWR reactor pressure vessel and such other components as are identified by the CEGB. This report, for 1987/8, states that the IVC has continued to make progress in the provision of the validation services as specified. (author)

Isolation and identification of bioactive compounds in Andrographis paniculata (Chuanxinlian

Directory of Open Access Journals (Sweden)

Lin Bi-Fong

2010-05-01

Full Text Available Abstract Andrographis paniculata (Burm. f. Nees (Acanthaceae is a medicinal plant used in many countries. Its major constituents are diterpenoids, flavonoids and polyphenols. Among the single compounds extracted from A. paniculata, andrographolide is the major one in terms of bioactive properties and abundance. Among the andrographolide analogues, 14-deoxy-11,12-didehydroandrographolide is immunostimulatory, anti-infective and anti-atherosclerotic; neoandrographolide is anti-inflammatory, anti-infective and anti-hepatotoxic; 14-deoxyandrographolide is immunomodulatory and anti-atherosclerotic. Among the less abundant compounds from A. paniculata, andrograpanin is both anti-inflammatory and anti-infective; 14-deoxy-14,15-dehydroandrographolide is anti-inflammatory; isoandrographolide, 3,19-isopropylideneandrographolide and 14-acetylandrographolide are tumor suppressive; arabinogalactan proteins are anti-hepatotoxic. The four flavonoids from A. paniculata, namely 7-O-methylwogonin, apigenin, onysilin and 3,4-dicaffeoylquinic acid are anti-atherosclerotic.

Effects of the EVCAM chemical validation library on differentiation using marker gene expression in lmouse embryonic stem cells

Science.gov (United States)

The adherent cell differentiation and cytotoxicity (ACDC) assay was used to profile the effects of the ECVAM EST validation chemical library (19 compounds) on J1 mouse embryonic stem cells (mESC). PCR-based TaqMan Low Density Arrays (TLDA) provided a high-content assessment of al...

NATURAL POLYACETYLENE COMPOUNDS

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A. M. Nasukhova

2014-01-01

Full Text Available In article the review of the initial stage of researches of natural polyacetylene compounds is resulted. The high reactionary ability leading to fast oxidation and degradation of these compounds, especially at influence of Uf-light, oxygen of air, pH and other factors, has caused the serious difficulties connected with an establishment of structure and studying of their physical and chemical properties. Therefore the greatest quantity of works of this stage is connected with studying of essential oils of plants from families Apiaceae, Araliaceae, Asteraceae, Campanulaceae, Olacaceae, Pittosporaceae and Santalaceae where have been found out, basically, diacetylene compounds. About development of physical and chemical methods of the analysis of possibility of similar researches have considerably extended. More than 2000 polyacetylenes are known today, from them more than 1100 are found out in plants fam. Asteraceae. Revolution in the field of molecular biology has allowed to study processes of biosynthesis of these compounds intensively.

Present and long-term composition of MSW landfill leachate: A review

DEFF Research Database (Denmark)

Kjeldsen, Peter; Barlaz, M.A.; Rooker, A.P.

2002-01-01

The major potential environmental impacts related to landfill leachate are pollution of groundwater and surface waters. Landfill leachate contains pollutants that can be categorized into four groups (dissolved organic matter, inorganic macrocomponents, heavy metals, and xenobiotic organic compounds...... are observed. In contrast, the concentration of ammonia does not decrease, and often constitutes a major long-term pollutant in leachate. A broad range of xenobiotic organic compounds is observed in landfill leachate. The long-term behavior of landfills with respect to changes in oxidation-reduction status...... is discussed based on theory and model simulations. It seems that the somewhere postulated enhanced release of accumulated heavy metals would not take place within the time frames of thousands of years. This is supported by a few laboratory investigations. The existing data and model evaluations indicate...

Validation of nine years of MOPITT V5 NIR using MOZAIC/IAGOS measurements: biases and long-term stability

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A. T. J. de Laat

2014-11-01

Full Text Available Validation results from a comparison between Measurement Of Pollution In The Troposphere (MOPITT V5 Near InfraRed (NIR carbon monoxide (CO total column measurements and Measurement of Ozone and Water Vapour on Airbus in-service Aircraft (MOZAIC/In-Service Aircraft for a Global Observing System (IAGOS aircraft measurements are presented. A good agreement is found between MOPITT and MOZAIC/IAGOS measurements, consistent with results from earlier studies using different validation data and despite large variability in MOPITT CO total columns along the spatial footprint of the MOZAIC/IAGOS measurements. Validation results improve when taking the large spatial footprint of the MOZAIC/IAGOS data into account. No statistically significant drift was detected in the validation results over the period 2002–2010 at global, continental and local (airport scales. Furthermore, for those situations where MOZAIC/IAGOS measurements differed from the MOPITT a priori, the MOPITT measurements clearly outperformed the MOPITT a priori data, indicating that MOPITT NIR retrievals add value to the MOPITT a priori. Results from a high spatial resolution simulation of the chemistry-transport model MOCAGE (MOdèle de Chimie Atmosphérique à Grande Echelle showed that the most likely explanation for the large MOPITT variability along the MOZAIC-IAGOS profile flight path is related to spatio-temporal CO variability, which should be kept in mind when using MOZAIC/IAGOS profile measurements for validating satellite nadir observations.

Mechanism of action of a pestivirus antiviral compound

Science.gov (United States)

Baginski, Scott G.; Pevear, Daniel C.; Seipel, Marty; Sun, Siu Chi Chang; Benetatos, Christopher A.; Chunduru, Srinivas K.; Rice, Charles M.; Collett, Marc S.

2000-01-01

We report here the discovery of a small molecule inhibitor of pestivirus replication. The compound, designated VP32947, inhibits the replication of bovine viral diarrhea virus (BVDV) in cell culture at a 50% inhibitory concentration of approximately 20 nM. VP32947 inhibits both cytopathic and noncytopathic pestiviruses, including isolates of BVDV-1, BVDV-2, border disease virus, and classical swine fever virus. However, the compound shows no activity against viruses from unrelated virus groups. Time of drug addition studies indicated that VP32947 acts after virus adsorption and penetration and before virus assembly and release. Analysis of viral macromolecular synthesis showed VP32947 had no effect on viral protein synthesis or polyprotein processing but did inhibit viral RNA synthesis. To identify the molecular target of VP32947, we isolated drug-resistant (DR) variants of BVDV-1 in cell culture. Sequence analysis of the complete genomic RNA of two DR variants revealed a single common amino acid change located within the coding region of the NS5B protein, the viral RNA-dependent RNA polymerase. When this single amino acid change was introduced into an infectious clone of drug-sensitive wild-type (WT) BVDV-1, replication of the resulting virus was resistant to VP32947. The RNA-dependent RNA polymerase activity of the NS5B proteins derived from WT and DR viruses expressed and purified from recombinant baculovirus-infected insect cells confirmed the drug sensitivity of the WT enzyme and the drug resistance of the DR enzyme. This work formally validates NS5B as a target for antiviral drug discovery and development. The utility of VP32947 and similar compounds for the control of pestivirus diseases, and for hepatitis C virus drug discovery efforts, is discussed. PMID:10869440

Validation of systems biology derived molecular markers of renal donor organ status associated with long term allograft function.

Science.gov (United States)

Perco, Paul; Heinzel, Andreas; Leierer, Johannes; Schneeberger, Stefan; Bösmüller, Claudia; Oberhuber, Rupert; Wagner, Silvia; Engler, Franziska; Mayer, Gert

2018-05-03

Donor organ quality affects long term outcome after renal transplantation. A variety of prognostic molecular markers is available, yet their validity often remains undetermined. A network-based molecular model reflecting donor kidney status based on transcriptomics data and molecular features reported in scientific literature to be associated with chronic allograft nephropathy was created. Significantly enriched biological processes were identified and representative markers were selected. An independent kidney pre-implantation transcriptomics dataset of 76 organs was used to predict estimated glomerular filtration rate (eGFR) values twelve months after transplantation using available clinical data and marker expression values. The best-performing regression model solely based on the clinical parameters donor age, donor gender, and recipient gender explained 17% of variance in post-transplant eGFR values. The five molecular markers EGF, CD2BP2, RALBP1, SF3B1, and DDX19B representing key molecular processes of the constructed renal donor organ status molecular model in addition to the clinical parameters significantly improved model performance (p-value = 0.0007) explaining around 33% of the variability of eGFR values twelve months after transplantation. Collectively, molecular markers reflecting donor organ status significantly add to prediction of post-transplant renal function when added to the clinical parameters donor age and gender.

Neurotoxicity in Preclinical Models of Occupational Exposure to Organophosphorus Compounds

Science.gov (United States)

Voorhees, Jaymie R.; Rohlman, Diane S.; Lein, Pamela J.; Pieper, Andrew A.

2017-01-01

Organophosphorus (OPs) compounds are widely used as insecticides, plasticizers, and fuel additives. These compounds potently inhibit acetylcholinesterase (AChE), the enzyme that inactivates acetylcholine at neuronal synapses, and acute exposure to high OP levels can cause cholinergic crisis in humans and animals. Evidence further suggests that repeated exposure to lower OP levels insufficient to cause cholinergic crisis, frequently encountered in the occupational setting, also pose serious risks to people. For example, multiple epidemiological studies have identified associations between occupational OP exposure and neurodegenerative disease, psychiatric illness, and sensorimotor deficits. Rigorous scientific investigation of the basic science mechanisms underlying these epidemiological findings requires valid preclinical models in which tightly-regulated exposure paradigms can be correlated with neurotoxicity. Here, we review the experimental models of occupational OP exposure currently used in the field. We found that animal studies simulating occupational OP exposures do indeed show evidence of neurotoxicity, and that utilization of these models is helping illuminate the mechanisms underlying OP-induced neurological sequelae. Still, further work is necessary to evaluate exposure levels, protection methods, and treatment strategies, which taken together could serve to modify guidelines for improving workplace conditions globally. PMID:28149268

Isolation and identification of antimicrobial compound from Mentha longifolia L. leaves grown wild in Iraq

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Al-Bayati Firas A

2009-06-01

Full Text Available Abstract Background Mentha longifolia L. (Lamiaceae leaves have been traditionally implemented in the treatment of minor sore throat and minor mouth or throat irritation by the indigenous people of Iraq, although the compounds responsible for the medicinal properties have not been identified. In the present study, an antimicrobial compound was isolated and characterized, and its biological activity was assessed. Methods The compound was isolated and characterized from the extracted essential oil using different spectral techniques: TLC, FTIR spectra and HPLC. Antimicrobial activity of the compound was assessed using both disc diffusion and microdilution method in 96 multi-well microtiter plates. Results A known compound was isolated from the essential oil of the plant and was identified as (- menthol. The isolated compound was investigated for its antimicrobial activity against seven selected pathogenic and non-pathogenic microorganisms: Staphylococcus aureus, Streptococcus mutans, Streptococcus faecalis, Streptococcus pyogenis, Lactobacillus acidophilus, Pseudomonas aeruginosa and the yeast Candida albicans. Menthol at different concentrations (1:1, 1:5, 1:10, 1:20 was active against all tested bacteria except for P. aeruginosa, and the highest inhibitory effect was observed against S. mutans (zone of inhibition: 25.3 mm using the disc diffusion method. Minimal inhibitory concentration MIC values ranged from 15.6–125.0 μg/ml, and the most promising results were observed against S. aureus and S. mutans (MIC 15.6 μg/ml while, S. faecalis, S. pyogenis and L. acidophilus ranked next (MIC 31.2 μg/ml. Furthermore, menthol achieved considerable antifungal activity against the yeast C. albicans (zone of inhibition range: 7.1–18.5 mm; MIC: 125.0. Conclusion The isolation of an antimicrobial compound from M. longifolia leaves validates the use of this plant in the treatment of minor sore throat and minor mouth or throat irritation.

Gram-negative and -positive bacteria differentiation in blood culture samples by headspace volatile compound analysis.

Science.gov (United States)

Dolch, Michael E; Janitza, Silke; Boulesteix, Anne-Laure; Graßmann-Lichtenauer, Carola; Praun, Siegfried; Denzer, Wolfgang; Schelling, Gustav; Schubert, Sören

2016-12-01

Identification of microorganisms in positive blood cultures still relies on standard techniques such as Gram staining followed by culturing with definite microorganism identification. Alternatively, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or the analysis of headspace volatile compound (VC) composition produced by cultures can help to differentiate between microorganisms under experimental conditions. This study assessed the efficacy of volatile compound based microorganism differentiation into Gram-negatives and -positives in unselected positive blood culture samples from patients. Headspace gas samples of positive blood culture samples were transferred to sterilized, sealed, and evacuated 20 ml glass vials and stored at -30 °C until batch analysis. Headspace gas VC content analysis was carried out via an auto sampler connected to an ion-molecule reaction mass spectrometer (IMR-MS). Measurements covered a mass range from 16 to 135 u including CO2, H2, N2, and O2. Prediction rules for microorganism identification based on VC composition were derived using a training data set and evaluated using a validation data set within a random split validation procedure. One-hundred-fifty-two aerobic samples growing 27 Gram-negatives, 106 Gram-positives, and 19 fungi and 130 anaerobic samples growing 37 Gram-negatives, 91 Gram-positives, and two fungi were analysed. In anaerobic samples, ten discriminators were identified by the random forest method allowing for bacteria differentiation into Gram-negative and -positive (error rate: 16.7 % in validation data set). For aerobic samples the error rate was not better than random. In anaerobic blood culture samples of patients IMR-MS based headspace VC composition analysis facilitates bacteria differentiation into Gram-negative and -positive.

Nonparametric estimation of the heterogeneity of a random medium using compound Poisson process modeling of wave multiple scattering.

Science.gov (United States)

Le Bihan, Nicolas; Margerin, Ludovic

2009-07-01

In this paper, we present a nonparametric method to estimate the heterogeneity of a random medium from the angular distribution of intensity of waves transmitted through a slab of random material. Our approach is based on the modeling of forward multiple scattering using compound Poisson processes on compact Lie groups. The estimation technique is validated through numerical simulations based on radiative transfer theory.

Reconstruction of organochlorine compound inputs in the Tagus Prodelta.

Science.gov (United States)

Mil-Homens, Mário; Vicente, Maria; Grimalt, Joan O; Micaelo, Cristina; Abrantes, Fátima

2016-01-01

Twenty century time-resolved variability of riverine deposits of polychlorobiphenyls (PCBs), DDTs, hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB) was studied in three (210)Pb dated sediment cores collected in a depositional shelf area adjacent to the Tagus estuary (the Tagus Prodelta). The geographic and temporal distribution patterns were consistent with discharge of these organochlorine compounds (OCs) in the area associated with the Tagus mouth. Their concentrations were not correlated with the sedimentary total organic carbon. The PCB down-core profiles were dominated by CB138 and CB153 (hexa-CBs) congeners followed by CB180 (hepta-CBs). Principal Component Analysis of the congener distributions of these compounds did not define temporal down-core trends. The ratios of DDT metabolites (p,p'-DDE/p,p'-DDT) were consistent with recent DDT inputs into the environment and/or earlier applications and long-term residence in soils/sediments until these were eroded and remobilized. Copyright © 2015 Elsevier B.V. All rights reserved.

Long-term relationships among pesticide applications, mobility, and soil erosion in a vineyard watershed.

Science.gov (United States)

Sabatier, Pierre; Poulenard, Jérôme; Fanget, Bernard; Reyss, Jean-Louis; Develle, Anne-Lise; Wilhelm, Bruno; Ployon, Estelle; Pignol, Cécile; Naffrechoux, Emmanuel; Dorioz, Jean-Marcel; Montuelle, Bernard; Arnaud, Fabien

2014-11-04

Agricultural pesticide use has increased worldwide during the last several decades, but the long-term fate, storage, and transfer dynamics of pesticides in a changing environment are poorly understood. Many pesticides have been progressively banned, but in numerous cases, these molecules are stable and may persist in soils, sediments, and ice. Many studies have addressed the question of their possible remobilization as a result of global change. In this article, we present a retro-observation approach based on lake sediment records to monitor micropollutants and to evaluate the long-term succession and diffuse transfer of herbicides, fungicides, and insecticide treatments in a vineyard catchment in France. The sediment allows for a reliable reconstruction of past pesticide use through time, validated by the historical introduction, use, and banning of these organic and inorganic pesticides in local vineyards. Our results also revealed how changes in these practices affect storage conditions and, consequently, the pesticides' transfer dynamics. For example, the use of postemergence herbicides (glyphosate), which induce an increase in soil erosion, led to a release of a banned remnant pesticide (dichlorodiphenyltrichloroethane, DDT), which had been previously stored in vineyard soil, back into the environment. Management strategies of ecotoxicological risk would be well served by recognition of the diversity of compounds stored in various environmental sinks, such as agriculture soil, and their capability to become sources when environmental conditions change.

Validation of an analytical method for the determination of polycyclic aromatic hydrocarbons by high efficiency liquid chromatography in PM10 and PM2,5 particles

International Nuclear Information System (INIS)

Herrera Murillo, Jorge; Chaves Villalobos, Maria del Carmen

2012-01-01

An analytical method was validated for polycyclic aromatic hydrocarbons in PM10 and PM2,5 particles collected from air by high performance liquid chromatography (HPLC) was validated. The PAHs analyzed in the methodology include: Naphthalene, Acenaphthylene, Fluorene, Acenaphthene, Phenanthrene, Anthracene, fluoranthene, pyrene, Benzo (a)anthracene, Chrysene, Benzo (b)fluoranthene, Benzo (k)fluoranthene, Benzo (a)pyrene, Dibenzo (a, h)anthracene, Benzo (g, h, i)perylene and Indeno (1,2,3-CD)pyrene. For these compounds, the detection limit and quantification limit have been between 0,02 and 0,1 mg/l. An equipment DIONEX, ICS 3000 model is used, that has two in series detectors: one ultraviolet model VWD-1, and fluorescence detector, model RF-2000, separating the different absorption and emission signals for proper identification of individual compounds. For all the compounds analyzed, the recovery factor has found not significantly different from each other and the repeatability and reproducibility has been to be suitable for an analytical method, especially for the lighter PAHs. (author) [es

Validation of a Semi-Quantitative Food Frequency Questionnaire for Argentinean Adults

OpenAIRE

Dehghan, Mahshid; del Cerro, Silvia; Zhang, Xiaohe; Cuneo, Jose Maini; Linetzky, Bruno; Diaz, Rafael; Merchant, Anwar T.

2012-01-01

BACKGROUND: The Food Frequency Questionnaire (FFQ) is the most commonly used method for ranking individuals based on long term food intake in large epidemiological studies. The validation of an FFQ for specific populations is essential as food consumption is culture dependent. The aim of this study was to develop a Semi-quantitative Food Frequency Questionnaire (SFFQ) and evaluate its validity and reproducibility in estimating nutrient intake in urban and rural areas of Argentina. METHODS/PRI...

Fault-tolerant clock synchronization validation methodology. [in computer systems

Science.gov (United States)

Butler, Ricky W.; Palumbo, Daniel L.; Johnson, Sally C.

1987-01-01

A validation method for the synchronization subsystem of a fault-tolerant computer system is presented. The high reliability requirement of flight-crucial systems precludes the use of most traditional validation methods. The method presented utilizes formal design proof to uncover design and coding errors and experimentation to validate the assumptions of the design proof. The experimental method is described and illustrated by validating the clock synchronization system of the Software Implemented Fault Tolerance computer. The design proof of the algorithm includes a theorem that defines the maximum skew between any two nonfaulty clocks in the system in terms of specific system parameters. Most of these parameters are deterministic. One crucial parameter is the upper bound on the clock read error, which is stochastic. The probability that this upper bound is exceeded is calculated from data obtained by the measurement of system parameters. This probability is then included in a detailed reliability analysis of the system.

Validation of the surgical fear questionnaire in adult patients waiting for elective surgery.

Directory of Open Access Journals (Sweden)

Maurice Theunissen

Full Text Available Because existing instruments for assessing surgical fear seem either too general or too limited, the Surgical Fear Questionnaire (SFQ was developed. The aim of this study is to assess the validity and reliability of the SFQ.Based on existing literature and expert consultation the ten-item SFQ was composed. Data on the SFQ were obtained from 5 prospective studies (N = 3233 in inpatient or day surgery patients. These data were used for exploratory factor analysis (EFA, confirmatory factor analysis (CFA, reliability analysis and validity analysis.EFA in Study 1 and 2 revealed a two-factor structure with one factor associated with fear of the short-term consequences of surgery (SFQ-s, item 1-4 and the other factor with fear of the long-term consequences of surgery (SFQ-l, item 5-10. However, in both studies two items of the SFQ-l had low factor loadings. Therefore in Study 3 and 4 the 2-factor structure was tested and confirmed by CFA in an eight-item version of the SFQ. Across all studies significant correlations of the SFQ with pain catastrophizing, state anxiety, and preoperative pain intensity indicated good convergent validity. Internal consistency (Cronbach's alpha was between 0.765-0.920 (SFQ-total, 0.766-0.877 (SFQ-s, and 0.628-0.899 (SFQ-l. The SFQ proved to be sensitive to detect differences based on age, sex, education level, employment status and preoperative pain intensity.The SFQ is a valid and reliable eight-item index of surgical fear consisting of two subscales: fear of the short-term consequences of surgery and fear of the long-term consequences.

Using 'big data' to validate claims made in the pharmaceutical approval process.

Science.gov (United States)

Wasser, Thomas; Haynes, Kevin; Barron, John; Cziraky, Mark

2015-01-01

Big Data in the healthcare setting refers to the storage, assimilation, and analysis of large quantities of information regarding patient care. These data can be collected and stored in a wide variety of ways including electronic medical records collected at the patient bedside, or through medical records that are coded and passed to insurance companies for reimbursement. When these data are processed it is possible to validate claims as a part of the regulatory review process regarding the anticipated performance of medications and devices. In order to analyze properly claims by manufacturers and others, there is a need to express claims in terms that are testable in a timeframe that is useful and meaningful to formulary committees. Claims for the comparative benefits and costs, including budget impact, of products and devices need to be expressed in measurable terms, ideally in the context of submission or validation protocols. Claims should be either consistent with accessible Big Data or able to support observational studies where Big Data identifies target populations. Protocols should identify, in disaggregated terms, key variables that would lead to direct or proxy validation. Once these variables are identified, Big Data can be used to query massive quantities of data in the validation process. Research can be passive or active in nature. Passive, where the data are collected retrospectively; active where the researcher is prospectively looking for indicators of co-morbid conditions, side-effects or adverse events, testing these indicators to determine if claims are within desired ranges set forth by the manufacturer. Additionally, Big Data can be used to assess the effectiveness of therapy through health insurance records. This, for example, could indicate that disease or co-morbid conditions cease to be treated. Understanding the basic strengths and weaknesses of Big Data in the claim validation process provides a glimpse of the value that this research

Method for numerical simulation of two-term exponentially correlated colored noise

International Nuclear Information System (INIS)

Yilmaz, B.; Ayik, S.; Abe, Y.; Gokalp, A.; Yilmaz, O.

2006-01-01

A method for numerical simulation of two-term exponentially correlated colored noise is proposed. The method is an extension of traditional method for one-term exponentially correlated colored noise. The validity of the algorithm is tested by comparing numerical simulations with analytical results in two physical applications

Rigor or Reliability and Validity in Qualitative Research: Perspectives, Strategies, Reconceptualization, and Recommendations.

Science.gov (United States)

Cypress, Brigitte S

Issues are still raised even now in the 21st century by the persistent concern with achieving rigor in qualitative research. There is also a continuing debate about the analogous terms reliability and validity in naturalistic inquiries as opposed to quantitative investigations. This article presents the concept of rigor in qualitative research using a phenomenological study as an exemplar to further illustrate the process. Elaborating on epistemological and theoretical conceptualizations by Lincoln and Guba, strategies congruent with qualitative perspective for ensuring validity to establish the credibility of the study are described. A synthesis of the historical development of validity criteria evident in the literature during the years is explored. Recommendations are made for use of the term rigor instead of trustworthiness and the reconceptualization and renewed use of the concept of reliability and validity in qualitative research, that strategies for ensuring rigor must be built into the qualitative research process rather than evaluated only after the inquiry, and that qualitative researchers and students alike must be proactive and take responsibility in ensuring the rigor of a research study. The insights garnered here will move novice researchers and doctoral students to a better conceptual grasp of the complexity of reliability and validity and its ramifications for qualitative inquiry.

Cultural adaptation and content validation of the Single-Question for screening alcohol abuse

Directory of Open Access Journals (Sweden)

Marjorie Ester Dias Maciel

2018-03-01

Full Text Available ABSTRACT Objective Describing the stages of translation, cultural adaptation and content validation of the Single-Question into Brazilian Portuguese, which will be named Questão Chave. Method This study is a cultural adaptation. The instrument was translated into Portuguese as two independent versions which led to a synthesis of translations (S1, and later to the synthesis S2, which was then submitted to evaluation by a Committee of Expert Judges in the area of alcohol use and instrument validation. The Content Validity Index and Kappa agreement coefficient were calculated from this evaluation. Results The judges evaluated the Questão Chave regarding the clarity of the sentence and aspects related to the quality of the translation (cultural adaptation, preservation of original meaning and correct use of technical terms. The Content Validity Index was 1 for clarity of sentence and correct use of technical terms, and 0.8 for adaptation and preservation of the original meaning. The Kappa index for concordance among the judges was 0.83. After an adjustment proposed by the judges, the S3 version was originated. Conclusion The Questão Chave had its content validity confirmed, which supports future studies that aim for its application in the target population to verify their psychometric properties.

Long-term predictions using natural analogues

International Nuclear Information System (INIS)

Ewing, R.C.

1995-01-01

One of the unique and scientifically most challenging aspects of nuclear waste isolation is the extrapolation of short-term laboratory data (hours to years) to the long time periods (10 3 -10 5 years) required by regulatory agencies for performance assessment. The direct validation of these extrapolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the lay public that there is a demonstrable and reasonable basis for accepting the long-term extrapolations. Natural systems (e.g., open-quotes natural analoguesclose quotes) provide perhaps the only means of partial open-quotes validation,close quotes as well as data that may be used directly in the models that are used in the extrapolation. Natural systems provide data on very large spatial (nm to km) and temporal (10 3 -10 8 years) scales and in highly complex terranes in which unknown synergisms may affect radionuclide migration. This paper reviews the application (and most importantly, the limitations) of data from natural analogue systems to the open-quotes validationclose quotes of performance assessments

Time-Variation of Term Premia: International Evidence

NARCIS (Netherlands)

Jongen, R.; Verschoor, W.F.C.; Wolff, C.C.P.

2006-01-01

This paper examines the validity of the expectations hypothesis of the term structure of interest rates by means of a previously unexploited dataset of market expectations that covers a broad range of EMS versus non-EMS foreign currency deposits. Although we find strong evidence in favour of

Design for validation: An approach to systems validation

Science.gov (United States)

Carter, William C.; Dunham, Janet R.; Laprie, Jean-Claude; Williams, Thomas; Howden, William; Smith, Brian; Lewis, Carl M. (Editor)

1989-01-01

Every complex system built is validated in some manner. Computer validation begins with review of the system design. As systems became too complicated for one person to review, validation began to rely on the application of adhoc methods by many individuals. As the cost of the changes mounted and the expense of failure increased, more organized procedures became essential. Attempts at devising and carrying out those procedures showed that validation is indeed a difficult technical problem. The successful transformation of the validation process into a systematic series of formally sound, integrated steps is necessary if the liability inherent in the future digita-system-based avionic and space systems is to be minimized. A suggested framework and timetable for the transformtion are presented. Basic working definitions of two pivotal ideas (validation and system life-cyle) are provided and show how the two concepts interact. Many examples are given of past and present validation activities by NASA and others. A conceptual framework is presented for the validation process. Finally, important areas are listed for ongoing development of the validation process at NASA Langley Research Center.

Stability of phenolic compounds of the propolis processed by ionizing radiation

International Nuclear Information System (INIS)

Matsuda, Andrea H.; Mastro, Nelida L. del

2002-01-01

Propolis is the generic term of a resin of different colors and consistency collected by bees, Apis mellifera, from diverse parts of plants, buds and resinous exudates. It possesses antibacterial , antifungal and antiviral properties and many other biological activities such as antiinflammatory, antiulcer, local anaesthetic, antitumor, etc. The aim of this work is to study the effect of 60 Co ionizing radiation on the stability of phenolic compounds of propolis. (author)

Predicting chemically-induced skin reactions. Part I: QSAR models of skin sensitization and their application to identify potentially hazardous compounds

Energy Technology Data Exchange (ETDEWEB)

Alves, Vinicius M. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Muratov, Eugene [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Laboratory of Theoretical Chemistry, A.V. Bogatsky Physical-Chemical Institute NAS of Ukraine, Odessa 65080 (Ukraine); Fourches, Denis [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Strickland, Judy; Kleinstreuer, Nicole [ILS/Contractor Supporting the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM), P.O. Box 13501, Research Triangle Park, NC 27709 (United States); Andrade, Carolina H. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Tropsha, Alexander, E-mail: alex_tropsha@unc.edu [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States)

2015-04-15

Repetitive exposure to a chemical agent can induce an immune reaction in inherently susceptible individuals that leads to skin sensitization. Although many chemicals have been reported as skin sensitizers, there have been very few rigorously validated QSAR models with defined applicability domains (AD) that were developed using a large group of chemically diverse compounds. In this study, we have aimed to compile, curate, and integrate the largest publicly available dataset related to chemically-induced skin sensitization, use this data to generate rigorously validated and QSAR models for skin sensitization, and employ these models as a virtual screening tool for identifying putative sensitizers among environmental chemicals. We followed best practices for model building and validation implemented with our predictive QSAR workflow using Random Forest modeling technique in combination with SiRMS and Dragon descriptors. The Correct Classification Rate (CCR) for QSAR models discriminating sensitizers from non-sensitizers was 71–88% when evaluated on several external validation sets, within a broad AD, with positive (for sensitizers) and negative (for non-sensitizers) predicted rates of 85% and 79% respectively. When compared to the skin sensitization module included in the OECD QSAR Toolbox as well as to the skin sensitization model in publicly available VEGA software, our models showed a significantly higher prediction accuracy for the same sets of external compounds as evaluated by Positive Predicted Rate, Negative Predicted Rate, and CCR. These models were applied to identify putative chemical hazards in the Scorecard database of possible skin or sense organ toxicants as primary candidates for experimental validation. - Highlights: • It was compiled the largest publicly-available skin sensitization dataset. • Predictive QSAR models were developed for skin sensitization. • Developed models have higher prediction accuracy than OECD QSAR Toolbox. • Putative

Predicting chemically-induced skin reactions. Part I: QSAR models of skin sensitization and their application to identify potentially hazardous compounds

International Nuclear Information System (INIS)

Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

2015-01-01

Repetitive exposure to a chemical agent can induce an immune reaction in inherently susceptible individuals that leads to skin sensitization. Although many chemicals have been reported as skin sensitizers, there have been very few rigorously validated QSAR models with defined applicability domains (AD) that were developed using a large group of chemically diverse compounds. In this study, we have aimed to compile, curate, and integrate the largest publicly available dataset related to chemically-induced skin sensitization, use this data to generate rigorously validated and QSAR models for skin sensitization, and employ these models as a virtual screening tool for identifying putative sensitizers among environmental chemicals. We followed best practices for model building and validation implemented with our predictive QSAR workflow using Random Forest modeling technique in combination with SiRMS and Dragon descriptors. The Correct Classification Rate (CCR) for QSAR models discriminating sensitizers from non-sensitizers was 71–88% when evaluated on several external validation sets, within a broad AD, with positive (for sensitizers) and negative (for non-sensitizers) predicted rates of 85% and 79% respectively. When compared to the skin sensitization module included in the OECD QSAR Toolbox as well as to the skin sensitization model in publicly available VEGA software, our models showed a significantly higher prediction accuracy for the same sets of external compounds as evaluated by Positive Predicted Rate, Negative Predicted Rate, and CCR. These models were applied to identify putative chemical hazards in the Scorecard database of possible skin or sense organ toxicants as primary candidates for experimental validation. - Highlights: • It was compiled the largest publicly-available skin sensitization dataset. • Predictive QSAR models were developed for skin sensitization. • Developed models have higher prediction accuracy than OECD QSAR Toolbox. • Putative

[Cognition-correlation indices of gender schema: tests of validity].

Science.gov (United States)

Ishida, E

1994-02-01

Four-hundred and seventy-seven subjects evaluated a set of traits and behaviors in terms of how masculine and feminine they were and in terms of how well they represented their real and ideal self-images. Within-individual correlation coefficients between these evaluations were proposed as measures of psychological gender schemata, because they would represent the degree of matching between the subjects' gender-image and ideal/real self-images of gender-related attributes. The present study aims at examining the construct validity of these measures, by testing them to psychological variables that are known to reflect gender identity. The individual difference variables used as criteria were (a) satisfaction with one's own sex, (b) general happiness, (c) self-esteem (d) gender-conflict, and (e) school and occupational achievement need. Correlations between the gender-schema indices and the criteria variables supported the construct validity of those measures. Advantages of the present measurement over the conventional simple trait approach, such as BSRI, or PAQ are discussed.

NMR and domain wall mobility in intermetallic compounds

International Nuclear Information System (INIS)

Guimaraes, A.P.; Sampaio, L.C.; Cunha, S.F.; Alves, K.M.B.

1991-01-01

The technique of pulsed NMR can be used to study the distribution of hyperfine fields in a magnetic matrix. The dynamics of the domain walls are relevant to the generation of NMR signals. In the present study on the (R x Y 1-x ) Fe 2 intermetallic compounds, the reduction in the signals is associated to increased propagation fields. This indicates that a smaller domain wall mobility is at the origin of these effects. NMR spectra in this system show the importance of direct and indirect (i.e., mediated by Fe atoms) terms in the transferred hyperfine field. (author)

Mining collections of compounds with Screening Assistant 2

Directory of Open Access Journals (Sweden)

Guilloux Vincent

2012-08-01

Full Text Available Abstract Background High-throughput screening assays have become the starting point of many drug discovery programs for large pharmaceutical companies as well as academic organisations. Despite the increasing throughput of screening technologies, the almost infinite chemical space remains out of reach, calling for tools dedicated to the analysis and selection of the compound collections intended to be screened. Results We present Screening Assistant 2 (SA2, an open-source JAVA software dedicated to the storage and analysis of small to very large chemical libraries. SA2 stores unique molecules in a MySQL database, and encapsulates several chemoinformatics methods, among which: providers management, interactive visualisation, scaffold analysis, diverse subset creation, descriptors calculation, sub-structure / SMART search, similarity search and filtering. We illustrate the use of SA2 by analysing the composition of a database of 15 million compounds collected from 73 providers, in terms of scaffolds, frameworks, and undesired properties as defined by recently proposed HTS SMARTS filters. We also show how the software can be used to create diverse libraries based on existing ones. Conclusions Screening Assistant 2 is a user-friendly, open-source software that can be used to manage collections of compounds and perform simple to advanced chemoinformatics analyses. Its modular design and growing documentation facilitate the addition of new functionalities, calling for contributions from the community. The software can be downloaded at http://sa2.sourceforge.net/.

Mining collections of compounds with Screening Assistant 2

Science.gov (United States)

2012-01-01

Background High-throughput screening assays have become the starting point of many drug discovery programs for large pharmaceutical companies as well as academic organisations. Despite the increasing throughput of screening technologies, the almost infinite chemical space remains out of reach, calling for tools dedicated to the analysis and selection of the compound collections intended to be screened. Results We present Screening Assistant 2 (SA2), an open-source JAVA software dedicated to the storage and analysis of small to very large chemical libraries. SA2 stores unique molecules in a MySQL database, and encapsulates several chemoinformatics methods, among which: providers management, interactive visualisation, scaffold analysis, diverse subset creation, descriptors calculation, sub-structure / SMART search, similarity search and filtering. We illustrate the use of SA2 by analysing the composition of a database of 15 million compounds collected from 73 providers, in terms of scaffolds, frameworks, and undesired properties as defined by recently proposed HTS SMARTS filters. We also show how the software can be used to create diverse libraries based on existing ones. Conclusions Screening Assistant 2 is a user-friendly, open-source software that can be used to manage collections of compounds and perform simple to advanced chemoinformatics analyses. Its modular design and growing documentation facilitate the addition of new functionalities, calling for contributions from the community. The software can be downloaded at http://sa2.sourceforge.net/. PMID:23327565

A comparative study of aroma-active compounds between dark and milk chocolate: relationship to sensory perception.

Science.gov (United States)

Liu, Jianbin; Liu, Mengya; He, Congcong; Song, Huanlu; Guo, Jia; Wang, Ye; Yang, Haiying; Su, Xiaoxia

2015-04-01

The most important aroma-active compounds of two types of chocolate and cocoa liquor used for their production were analysed by gas chromatography-olfactometry-mass spectrometry (GC-O-MS) and aroma extract dilution analysis (AEDA). Furthermore, the relationship between odorants and sensory perception of chocolate was measured by quantitative analysis, sensory evaluation and correlation analysis. In addition, some chemicals were added to the original dark or milk chocolate to validate their roles in the aroma property of chocolate. A total of 32 major aroma-active compounds were identified in the chocolate with the flavour dilution factors of 27-729 by AEDA, including seven aldehydes, six pyrazines, three pyrroles, four carboxylic acids, four lactones, two alcohols, two ketones, one ester, one pyrone, one furan and one sulfur-containing compound. Further quantitative analysis showed that dark chocolate had higher contents of pyrazine, pyrrole, carboxylic acids, alcohols and Strecker aldehydes, whereas the concentration of lactones, esters, long chain aldehydes and ketones were higher in the milk type. Differences in volatile composition and descriptive flavour attributes between the dark and milk chocolate were observed. The relationship between aroma-active compounds and sensory perception in the chocolate was verified. © 2014 Society of Chemical Industry.

Screening SIRT1 Activators from Medicinal Plants as Bioactive Compounds against Oxidative Damage in Mitochondrial Function

Directory of Open Access Journals (Sweden)

Yi Wang

2016-01-01

Full Text Available Sirtuin type 1 (SIRT1 belongs to the family of NAD+ dependent histone deacetylases and plays a critical role in cellular metabolism and response to oxidative stress. Traditional Chinese medicines (TCMs, as an important part of natural products, have been reported to exert protective effect against oxidative stress in mitochondria. In this study, we screened SIRT1 activators from TCMs and investigated their activities against mitochondrial damage. 19 activators were found in total by in vitro SIRT1 activity assay. Among those active compounds, four compounds, ginsenoside Rb2, ginsenoside F1, ginsenoside Rc, and schisandrin A, were further studied to validate the SIRT1-activation effects by liquid chromatography-mass spectrometry and confirm their activities against oxidative damage in H9c2 cardiomyocytes exposed to tert-butyl hydroperoxide (t-BHP. The results showed that those compounds enhanced the deacetylated activity of SIRT1, increased ATP content, and inhibited intracellular ROS formation as well as regulating the activity of Mn-SOD. These SIRT1 activators also showed moderate protective effects on mitochondrial function in t-BHP cells by recovering oxygen consumption and increasing mitochondrial DNA content. Our results suggested that those compounds from TCMs attenuated oxidative stress-induced mitochondrial damage in cardiomyocytes through activation of SIRT1.

Electronic, phonon and superconducting properties of LaPtBi half-Heusler compound

Science.gov (United States)

Shrivastava, Deepika; Sanyal, Sankar P.

2018-05-01

In the framework of density functional theory based on plane wave pseudopotential method and linear response technique, we have studied the electronic, phonon and superconducting properties of LaPtBi half-Heusler compound. The electronic band structure and density of states show that it is gapless semiconductor which is consistent with previous results. The positive phonon frequencies confirm the stability of this compound in cubic MgAgAs phase. Superconductivity is studied in terms of Eliashberg spectral function (α2F(ω)), electron-phonon coupling constants (λ). The value of electron-phonon coupling parameter is found to be 0.41 and the superconducting transition temperature is calculated to be 0.76 K, in excellent agreement with the experimentally reported values.

Multipurpose Compound

Science.gov (United States)

1983-01-01

Specially formulated derivatives of an unusual basic compound known as Alcide may be the answer to effective treatment and prevention of the disease bovine mastitis, a bacterial inflammation of a cow's mammary gland that results in loss of milk production and in extreme cases, death. Manufactured by Alcide Corporation the Alcide compound has killed all tested bacteria, virus and fungi, shortly after contact, with minimal toxic effects on humans or animals. Alcide Corporation credits the existence of the mastitis treatment/prevention products to assistance provided the company by NERAC, Inc.

Validation of an automated seizure detection algorithm for term neonates

Science.gov (United States)

Mathieson, Sean R.; Stevenson, Nathan J.; Low, Evonne; Marnane, William P.; Rennie, Janet M.; Temko, Andrey; Lightbody, Gordon; Boylan, Geraldine B.

2016-01-01

Objective The objective of this study was to validate the performance of a seizure detection algorithm (SDA) developed by our group, on previously unseen, prolonged, unedited EEG recordings from 70 babies from 2 centres. Methods EEGs of 70 babies (35 seizure, 35 non-seizure) were annotated for seizures by experts as the gold standard. The SDA was tested on the EEGs at a range of sensitivity settings. Annotations from the expert and SDA were compared using event and epoch based metrics. The effect of seizure duration on SDA performance was also analysed. Results Between sensitivity settings of 0.5 and 0.3, the algorithm achieved seizure detection rates of 52.6–75.0%, with false detection (FD) rates of 0.04–0.36 FD/h for event based analysis, which was deemed to be acceptable in a clinical environment. Time based comparison of expert and SDA annotations using Cohen’s Kappa Index revealed a best performing SDA threshold of 0.4 (Kappa 0.630). The SDA showed improved detection performance with longer seizures. Conclusion The SDA achieved promising performance and warrants further testing in a live clinical evaluation. Significance The SDA has the potential to improve seizure detection and provide a robust tool for comparing treatment regimens. PMID:26055336

Biological validation of a sample preparation method for ER-CALUX bioanalysis of estrogenic activity in sediments using mixtures of xeno-estrogens

NARCIS (Netherlands)

Houtman, C.J.; Houten, Y.K.; Leonards, P.E.G.; Brouwer, A.; Lamoree, M.H.; Legler, J.

2006-01-01

The combined estrogenic effects of mixtures of environmental pollutants in the in vitro ER-CALUX (chemical activated luciferase gene expression) bioassay were examined to biologically validate a sample preparation method for the analysis of estrogenic compounds in sediment. The method used

Biolonical validation of a sample preparation method for ER-CALUX bioanalysis of estrogenic activity in sediment using mixtures of xeno-estrogens

NARCIS (Netherlands)

Houtman, C.J.; Houten, Van Y.K.; Leonards, P.E.G.; Brouwer, A.; Lamoree, M.H.; Legler, J.

2006-01-01

The combined estrogenic effects of mixtures of environmental pollutants in the in vitro ER-CALUX (chemical activated luciferase gene expression) bioassay were examined to biologically validate a sample preparation method for the analysis of estrogenic compounds in sediment. The method used