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Enantioselective analysis of mirtazapine, demethylmirtazapine and 8-hydroxy mirtazapine in human urine after solid-phase microextraction

SANTANA, Fernando Jose Malagueno de; JABOR, Valquiria Aparecida Polisel; CESARINO, Evandro Jose; LANCHOTE, Vera Lucia; BONATO, Pierina Sueli
Fonte: WILEY-V C H VERLAG GMBH Publicador: WILEY-V C H VERLAG GMBH
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
466.66555%
A selective and reproducible off-line solid-phase microextraction procedure was developed for the simultaneous enantioselective determination of mirtazapine (MRT), demethylmirtazapine and 8-hydroxymirtazapine in human urine. CE was used for optimization of the extraction procedure whereas LC-MS was used for method validation and application. The influence of important factors in the solid-phase microextraction efficiency is discussed, such as the fiber coatings, extraction time, pH, ionic strength, temperature and desorption time. Before extraction, human urine samples were submitted to enzymatic hydrolysis at 37 degrees C for 16 h. Then, the enzyme was precipitated with trichloroacetic acid and the pH was adjusted to 8 with 1 mol/L pH 11 phosphate buffer solution. In the extraction, the analytes were transferred from the aqueous solution to the polydimethylsiloxane-divinylbenzene fiber coating and then desorbed in methanol. The mean recoveries were 5.4, 1.7 and 1.0% for MRT, demethylmirtazapine and 8-hydroxymirtazapine enantiomers, respectively. The method was linear over the concentration range of 62-1250 ng/mL. The within-day and between-day assay precision and accuracy were lower than 15%. The method was successfully employed in a preliminary cumulative urinary excretion study after administration of racemic MRT to a healthy volunteer.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); CNPq (Conselho Nacional de Desenvolvimento Cienifico...

Peat as a natural solid-phase for copper preconcentration and determination in a multicommuted flow system coupled to flame atomic absorption spectrometry

GONZALES, A. P. S.; FIRMINO, M. A.; NOMURA, C. S.; ROCHA, F. R. P.; OLIVEIRA, P. V.; GAUBEUR, I.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
447.5947%
The physical and chemical characteristics of peat were assessed through measurement of pH, percentage of organic matter, cationic exchange capacity (CEC), elemental analysis, infrared spectroscopy and quantitative analysis of metals by ICP OES. Despite the material showed to be very acid in view of the percentage of organic matter, its CEC was significant, showing potential for retention of metal ions. This characteristic was exploited by coupling a peat mini-column to a flow system based on the multicommutation approach for the in-line copper concentration prior to flame atomic absorption spectrometric determination. Cu(II) ions were adsorbed at pH 4.5 and eluted with 0.50 mol L(-1) HNO(3). The influence of chemical and hydrodynamic parameters, such as sample pH, buffer concentration, eluent type and concentration, sample flow-rate and preconcentration time were investigated. Under the optimized conditions, a linear response was observed between 16 and 100 mu g L(-1), with a detection limit estimated as 3 mu g L(-1) at the 99.7% confidence level and an enrichment factor of 16. The relative standard deviation was estimated as 3.3% (n = 20). The mini-column was used for at least 100 sampling cycles without significant variation in the analytical response. Recoveries from copper spiked to lake water or groundwater as well as concentrates used in hemodialysis were in the 97.3-111 % range. The results obtained for copper determination in these samples agreed with those achieved by graphite furnace atomic absorption spectrometry (GFAAS) at the 95% confidence level. (C) 2009 Elsevier B.V. All rights reserved.; Brazilian agencies Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Fundo Mackenzie de Pesquisa and Universidade Federal do ABC (UFABC); Fundo Mackenzie de Pesquisa and Universidade Federal do ABC (UFABC)

Metodologias para determinação de fármacos, metabólitos e disruptores endócrinos em água de abastecimento público utilizando técnicas de separação em meio líquido (CE/UV, CE-MS, LC-MS/MS); Methods for determination of pharmaceuticals, their metabolites and endocrine disruptors in surface water using separation techniques in liquid media (CE/UV, CE-MS, HPLC-MS/MS)

Costa, Ana Carolina de Oliveira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 03/12/2009 PT
Relevância na Pesquisa
385.77117%
Este trabalho apresenta o desenvolvimento e validação de métodos analíticos para investigar a presença de fármacos e seus metabólitos, assim como disruptores endócrinos, em amostras de águas superficiais, utilizando estratégias de "clean up" e enriquecimento de amostra no modo "on line" ("stacking") e "off line" (extração em fase sólida, SPE), em junção com técnicas de separação avançadas em meio líquido (eletroforese capilar, CE, e cromatografia a líquido, LC, com detecção UV, e seus acoplamentos com espectrometria de massas). No primeiro Capítulo são discutidos aspectos gerais sobre os produtos farmacêuticos, produtos de higiene pessoal e disruptores endócrinos, bem como a origem e ocorrência destas substâncias no meio ambiente. O segundo Capítulo aborda o desenvolvimento de um método de separação capaz de determinar oito substâncias entre fármacos de caráter ácido e metabólitos (diclofenaco, bezafibrato, fenoprofeno, ibuprofeno, cetoprofeno, naproxeno e ácidos gentísico e salicílico) numa única corrida, utilizando eletroforese capilar com enriquecimento em linha da amostra (stacking do analito baseado em grande volume de injeção da amostra) utilizando eletrólito de corrida constituído por 30 mmol L-1 de tetraborato de sódio e 5 mmol L-1 de Brij 35...

Desenvolvimento e caracterização de materiais baseados em sílica com aplicabilidade em extração em fase sólida e cromatografia líquida de ultra alta eficiência; Development and characterization of silica based materials with applicability in solid phase extraction and ultra high performance liquid chromatography

Nazário, Carlos Eduardo Domingues
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 21/01/2013 PT
Relevância na Pesquisa
379.0293%
Atualmente, a demanda e a necessidade de metodologias analíticas e bioanalíticas que promovam análise rápida e seletiva tem impulsionado o constante desenvolvimento de sorventes para preparo de amostra e fases estacionárias para cromatografia líquida de alta eficiência (HPLC). Desta maneira, esta tese tem por objetivo desenvolver materiais utilizando precursores de sílica com aplicação em preparo de amostra e suportes cromatográficos para cromatografia líquida de ultra alta eficiência (UHPLC). Foram sintetizadas e caracterizadas duas fases extratoras as quais tiveram sua aplicabilidade demonstrada na extração de fármacos em fluidos biológicos empregando a técnica de extração em fase sólida (SPE). A primeira metodologia desenvolvida foi a síntese de partículas de sílica empregando precursores de baixo custo (silicato de sódio) pelo método sil-gel. Após a funcionalização com grupamento C18, e caracterização da fase extratora, o material sintetizado foi aplicado em SPE off-line para a determinação de fluoxetina e seu metabólito, norfluoxetina, em plasma humano por HPLC-UV. O método desenvolvido foi validado e aplicado em amostra de plasma de pacientes sob tratamento de fluoxetina. Além disso, o sorvente desenvolvido apresentou resultados similares quando comparado com fases extratoras comerciais. O segundo método desenvolvido utilizou a técnica de impressão molecular (MIP) a qual tem se tornado uma fase extratora atrativa devido a sua maior seletividade em relação as fases típicas empregadas em SPE. Ao mesmo tempo...

On-line extraction and determination of carbofuran in raw milk by direct HPLC injection on an ISRP column

Menezes, M. L.; Felix, G.; Demarchi, ACCO
Fonte: Vieweg Publicador: Vieweg
Tipo: Artigo de Revista Científica Formato: 81-83
ENG
Relevância na Pesquisa
462.4697%
A method has been developed for extraction and determination of carbofuran in milk. The method involved direct injection of raw milk on to a human serum albumin dimethyloctyl-silica gel (HSA-Cs) column and the use of 80:20 (v/v) 0.01 M phosphate buffer pH 5.5 - acetonitrile as mobile phase. UV spectrophotometric detection was performed at 220 nm. Identification was based on retention time. Quantification was performed by automatic peak-area determination and was calibrated by use of an external standard.

Estudo comparativo entre os custos de manufaturas e as propriedades funcionais de oleos volateis obtidos por extração supercritica e destilação por arraste a vapor.; Comparative study of cost of manufacturing and functional properties of volatile oils obtained by supercritical fluid extraction and steam distillation.

Patricia Franco Leal
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 29/02/2005 PT
Relevância na Pesquisa
382.09453%
Este estudo teve por objetivo comparar o custo de manufatura (COM) de extratos vegetais e óleos voláteis de plantas aromáticas, condimentares e medicinais nativas ou adaptáveis ao cultivo brasileiro obtidos por processos de extração considerados limpos e que não agridem o meio ambiente. Foi realizado o estudo técnico-econômico do processo de extração com fluido supercrítico (SFE) e destilação por arraste a vapor (SD) para obtenção de extratos vegetais e óleos voláteis. A metodologia de estimativa de custo de manufatura utilizada neste estudo resulta em COM classe 4 ou 5, sendo uma estimativa preliminar para a decisão de prosseguimento ou a interrupção do projeto. As estimativas dos custos de manufatura dos extratos foram realizadas através das curvas globais de extração (OEC) dos sistemas determinadas experimentalmente neste trabalho (alecrim + vapor, camomila + vapor, erva-doce + vapor, erva-baleeira + vapor, erva-baleeira + CO2, canelinha + CO2) e também através das OECs da literatura (alecrim + vapor, alecrim + CO2, erva-doce + vapor, erva-doce + CO2,, gengibre + CO2, camomila + CO2, pimenta-do-reino + vapor, pimenta-do-reino + CO2, funcho + CO2,). As curvas globais de extração foram ajustadas a um spline contendo duas ou 3 retas: a primeira reta descreve a taxa de transferência de massa no período de taxa de extração constante (CER)...

Breast skin-line detection using dynamic programming

Silva, C. A.; Lima, C. S.; Correia, J. H.
Fonte: IEEE Publicador: IEEE
Tipo: Artigo de Revista Científica
Publicado em /09/2011 ENG
Relevância na Pesquisa
460.0808%
In this paper, we present a novel method to extract the breast skin-line based on dynamic programming. Skin-line extraction is an important preprocessing step in CAD systems; however, it is a challenging problem due to the presence of noise, underexposed regions, which results in a low contrast area near the skin-air interface, and artifacts such as labels. Our proposal utilizes the stroma edge to constrain searching for the border. In order to cope with noise, we consider several candidate points for the border interface which are obtained by the Laplace operator applied in pre-defined directions in the mammogram. The breast contour is obtained from the candidate points using a dynamic programming algorithm. This utilizes a criterion of optimality to obtain the optimum contour by minimization of a cost function. The method was evaluated using 82 mammograms whose contour were manually extracted by a radiologist from the mini- MIAS database. The Polyline Distance Measure was evaluated for each contour selected with the proposed method, obtaining a mean error of 2.05 pixels and a standard deviation of 0.80.; Fundação para a Ciência e a Tecnologia (FCT)

Potentiometric multi-syringe flow injection system for determination of exchangeable potassium in soils with in-line extraction

Almeida, M. Inês G.S.; Segundo, Marcela A.; Lima, José L.F.C.; Rangel, António O.S.S.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2006 ENG
Relevância na Pesquisa
880.0645%
A multi-syringe flow injection system for the potentiometric determination of exchangeable potassium in soil samples is proposed. Firstly, a manifold was devised to allow determination in soil extracts prepared off-line. It was possible to analyze samples prepared in extractants with different composition (Mehlich or Morgan) without physical or chemical modification of the manifold. A linear dynamic concentration range of 6–391 mg L−1 was obtained, allowing the direct introduction of soil extract without dilution. A determination frequency of 50 h−1 was achieved, with good repeatability for 10 consecutive injections of soil extracts (RSDb3.0%). The in-line preparation of soil extract was implemented by automatic addition of extractant solution to a previously weighed portion of soil, followed by in-line filtration. Good repeatability was attained as the variance of the extraction procedure was not significantly different from the variance obtained in consecutive measurements of the same extract. Furthermore, results comparable to those obtained by off-line extraction and determination by flame emission spectrometry were attained for the two soil samples tested. Using this procedure, a determination frequency of 13 h−1 and a sampling rate of 4 h−1 were achieved.

Sistema limpo em linha para extração em fase sólida de contaminantes emergentes em águas naturais

Sodré,Fernando F.; Locatelli,Marco Antonio F.; Jardim,Wilson F.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 PT
Relevância na Pesquisa
459.58992%
A solid-phase in-line extraction system for water samples containing low levels of emerging contaminants is described. The system was specially developed for large volume samples (up to 4 L) using commercial solid-phase extraction (SPE) cartridges. Four sets containing PTFE-made connectors, brass adapters and ball valves were used to fit SPE cartridges and sample bottles to a 4-port manifold attached to a 20 L carboy. A lab-made vacuum device was connected to the manifold cap. The apparatus is robust and less expensive than the typical available system. Its also provides less experimental handling, avoiding cross contamination and sample losses.

CAUDLES-EF: Carotid Automated Ultrasound Double Line Extraction System Using Edge Flow

Molinari, Filippo; Meiburger, Kristen M.; Zeng, Guang; Nicolaides, Andrew; Suri, Jasjit S.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
468.8094%
The evaluation of the carotid artery wall is essential for the diagnosis of cardiovascular pathologies or for the assessment of a patient’s cardiovascular risk. This paper presents a completely user-independent algorithm, which automatically extracts the far double line (lumen–intima and media–adventitia) in the carotid artery using an Edge Flow technique based on directional probability maps using the attributes of intensity and texture. Specifically, the algorithm traces the boundaries between the lumen and intima layer (line one) and between the media and adventitia layer (line two). The Carotid Automated Ultrasound Double Line Extraction System based on Edge-Flow (CAUDLES-EF) is characterized and validated by comparing the output of the algorithm with the manual tracing boundaries carried out by three experts. We also benchmark our new technique with the two other completely automatic techniques (CALEXia and CULEXsa) we previously published. Our multi-institutional database consisted of 300 longitudinal B-mode carotid images with normal and pathologic arteries. We compared our current new method with previous methods, and showed the mean and standard deviation for the three methods: CALEXia, CULEXsa, and CAUDLES-EF as 0.134 ± 0.088...

Correction Method for Line Extraction in Vision Measurement

Shao, Mingwei; Wei, Zhenzhong; Hu, Mengjie; Zhang, Guangjun
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 18/05/2015 EN
Relevância na Pesquisa
480.46688%
Over-exposure and perspective distortion are two of the main factors underlying inaccurate feature extraction. First, based on Steger’s method, we propose a method for correcting curvilinear structures (lines) extracted from over-exposed images. A new line model based on the Gaussian line profile is developed, and its description in the scale space is provided. The line position is analytically determined by the zero crossing of its first-order derivative, and the bias due to convolution with the normal Gaussian kernel function is eliminated on the basis of the related description. The model considers over-exposure features and is capable of detecting the line position in an over-exposed image. Simulations and experiments show that the proposed method is not significantly affected by the exposure level and is suitable for correcting lines extracted from an over-exposed image. In our experiments, the corrected result is found to be more precise than the uncorrected result by around 45.5%. Second, we analyze perspective distortion, which is inevitable during line extraction owing to the projective camera model. The perspective distortion can be rectified on the basis of the bias introduced as a function of related parameters. The properties of the proposed model and its application to vision measurement are discussed. In practice...

Profile changes in premolar extraction; Alterações no perfil em extrações de pré-molares

Allgayer, Susiane; de Lima, Eduardo Martinelli Santayana; Rizzatto, Susana Maria Deon; Tavares, Carlos Alberto Estevanell; Menezes, Luciane Macedo de; Mezzomo, Mauricio Barbieri
Fonte: EDIPUCRS Publicador: EDIPUCRS
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
464.28953%
Purpose: This retrospective study assessed patients treated with extraction of premolars by analysis of lateral cephalograms, comparing the effect of different tooth extraction protocols on the profile. Methods: Eighty-seven patients were selected from the private practices of three orthodontists certified by the Brazilian Board of Orthodontics and Facial Orthopedics. These patients were treated with fixed edgewise appliances and divided into three groups according to the sequence in which premolars were extracted: “Group 40”, maxillary first premolars (22 patients); “Group 44”, both maxillary and mandibular first premolars (43 patients); and “Group 45”, maxillary first and mandibular second premolars (22 patients). The Z angle and the Burstone line were used to quantify and compare the profiles before and after treatment. Results: Student’s t-test showed profile improvement in all groups, as the Z angle value was higher at treatment completion and the lip measurements were in agreement with the values recommended by Burstone. Analysis of treatment changes by the ANOVA did not reveal significant differences between groups. Conclusion: The protocols produced similar facial appearance at treatment completion.; Objetivo: Este estudo retrospectivo avaliou pacientes tratados com exodontias de pré-molares através da análise de telerradiografias...

Herstellung, In-line-Einschluss und Charakterisierung lipophiler und hydrophiler Kamillenextrakte unter Einsatz von verdichtetem Kohlendioxid; Production, In-line-Inclusion and Characterisation of lipophilic and hydrophilic chamomile extracts using dense carbon dioxide

Kaiser, Claudia Susanne
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
Relevância na Pesquisa
587.41375%
In dieser Arbeit werden die Möglichkeiten der Anwendung von überkritischem CO2 im Bereich der Naturstoffextraktion anhand der Kamille als Modellpflanze untersucht. Kamillenblüten enthalten eine Vielzahl von pharmakologisch wirksamen Inhaltsstoffen mit unterschiedlichsten Eigenschaften im Hinblick auf Polarität und Stabilität und stellen damit eine ideale Matrix dar, um ein breites Spektrum an Einflussgrößen zu untersuchen. Die Optimierung der Extraktionsparameter ergibt hohe Selektivität für die Bestandteile des ätherischen Kamillenöls bei guter Gesamtausbeute und kurzer Prozesszeit, wenn die Extraktion bei 40 °C, 90 bar und 8 kg CO2/h über 3 h durchgeführt wird. Der Einsatz zerkleinerten Drogenmaterials verbessert die Gesamtausbeute ohne einen negativen Einfluss auf die Stabilität der Inhaltsstoffe zu haben. Aufgrund der Hydrolyseempfindlichkeit des Matricins in Gegenwart des co-extrahierten Wassers ist eine Gefriertrocknung der Extrakte obligatorisch. Damit kann die Extraktion mit überkritischem CO2 als schnelle, schonende, gut reproduzierbare Methode eine Alternative zu herkömmlichen Extraktionsverfahren darstellen. Sie führt zu Extrakten hoher Qualität und ohne toxikologisch bedenkliche Rückstände an Lösungsmitteln. Matricin kann mittels überkritischem CO2 angereichert und bei kühler Lagerung (-30 °C bis +5 °C) über 6 Monate stabilisiert werden. Bei Raumtemperatur oder +30 °C erfolgt eine kontinuierliche Abnahme des Matricingehaltes über 3-4 Monate...

Anreicherung und In-line-Einschluss von Hyperforin aus Hypericum perforatum L. mittels überkritischer CO2-Extraktion; Enrichment and in-line-inclusion of hyperforin from Hypericum perforatum L. by supercritical CO2-extraction

Römpp, Harald
Fonte: Universität Tübingen Publicador: Universität Tübingen
Tipo: Dissertation; info:eu-repo/semantics/doctoralThesis
DE_DE
Relevância na Pesquisa
590.59902%
Zubereitungen aus Johanniskraut (Hypericum perforatum L.) auf ethanolisch-wässriger Basis spielen eine große Rolle in der Behandlung leichter bis mittelschwerer depressiver Erkrankungen. Das Phloroglucinderivat Hyperforin konnte in zahlreichen Arbeiten als ein wichtiger wirksamkeitsmitbestimmender Inhaltsstoff nachgewiesen werden, es unterliegt jedoch bei herkömmlichen Extraktionsverfahren einem raschen lichtinduzierten, thermischen und oxidativen Abbau. Ziel der vorliegenden Arbeit ist die selektive Anreicherung von Hyperforin aus Johanniskraut mittels überkritischer CO2-Extraktion und dessen Stabilitätsverbesserung durch In-line-Einschluss in beta-Cyclodextrine. Sämtliche Extraktionsversuche werden auf einer Anlage im Pilotmaßstab mit einem 1,2 l-Extraktionsbehälter durchgeführt. Zunächst wird der Einfluss des Extraktionsdruckes (90, 120 und 150 bar), der Extraktionstemperatur (40 und 50 °C, des CO2-Massenflusses (4, 8 und 12 kg CO2/h), der Extraktionsdauer (1, 3 und 5 h) und des Zerkleinerungsgrades der Droge auf das Extraktionsergebnis untersucht und das Extraktionsverfahren hinsichtlich Extraktausbeute, Hyperforingehalt der Extrakte, Restgehalt in der extrahierten Droge und Zersetzungstendenz von Hyperforin während der Extraktion optimiert. Die Erhöhung des Extraktionsdruckes von 90 auf 120 bar führt in Folge einer erhöhten Dichte und damit verbunden einer gesteigerten Lösungskapazität zu einer Erhöhung der Extraktausbeute von 1...

Profile changes in premolar extraction

Allgayer,Susiane; Lima,Eduardo M. Santayana de; Rizzatto,Susana Deon; Tavares,Carlos Alberto Estevanell; Menezes,Luciane Macedo de; Mezzomo,Mauricio Barbieri
Fonte: Pontifícia Universidade Católica do Rio Grande do Sul Publicador: Pontifícia Universidade Católica do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2011 EN
Relevância na Pesquisa
464.28953%
PURPOSE: This retrospective study assessed patients treated with extraction of premolars by analysis of lateral cephalograms, comparing the effect of different tooth extraction protocols on the profile. METHODS: Eighty-seven patients were selected from the private practices of three orthodontists certified by the Brazilian Board of Orthodontics and Facial Orthopedics. These patients were treated with fixed edgewise appliances and divided into three groups according to the sequence in which premolars were extracted: "Group 40", maxillary first premolars (22 patients); "Group 44", both maxillary and mandibular first premolars (43 patients); and "Group 45", maxillary first and mandibular second premolars (22 patients). The Z angle and the Burstone line were used to quantify and compare the profiles before and after treatment. RESULTS: Student's t-test showed profile improvement in all groups, as the Z angle value was higher at treatment completion and the lip measurements were in agreement with the values recommended by Burstone. Analysis of treatment changes by the ANOVA did not reveal significant differences between groups. CONCLUSION: The protocols produced similar facial appearance at treatment completion.

Estimativas de m+a' e d como indicadores do potencial de híbridos de milho para extração de linhagens; Estimation of m+a´and d and the potential single cross of maize hybrids for line extraction

Viana, Laryssa Ferreira
Fonte: UNIVERSIDADE FEDERAL DE LAVRAS; DBI - Departamento de Biologia; UFLA; BRASIL Publicador: UNIVERSIDADE FEDERAL DE LAVRAS; DBI - Departamento de Biologia; UFLA; BRASIL
Tipo: Dissertação
Publicado em 07/10/2014 PT_BR
Relevância na Pesquisa
474.50375%
O presente trabalho foi conduzido com o objetivo de estimar a contribuição dos locos em heterozigose (d) e a contribuição dos locos em homozigose (m+a´) de caracteres morfofisiológicos para verificar o potencial de híbridos comerciais na utilização em programas de melhoramento. Foram utilizadas as gerações F1 e F2 de dez híbridos simples comerciais (DKB 199, 30F90, A2555, DKB 333B, DOW 657, AG 8060, 30F87, DOW 8420, 30K75, AG 7000). De posse da geração F1 desses híbridos, adquirida no comércio local, foram obtidas as gerações F2=S0 de cada híbrido, por meio de autofecundações controladas. Os experimentos foram conduzidos em Lavras, na Fazenda Experimental Vitorinha e em Ijaci, no ano agrícola de 2005/06. Os tratos culturais foram os normalmente utilizados pelos agricultores para a cultura do milho na região. Os tratamentos foram avaliados utilizando-se o delineamento em blocos casualizados, com três repetições, sendo os dados tomados em cinco plantas/repetição. Os caracteres avaliados foram: altura de plantas, altura de espiga, número de folhas acima da espiga, diâmetro do colmo, comprimento da espiga, diâmetro da espiga, diâmetro do sabugo, peso da espiga e peso de grãos. Foi realizada uma análise de variância por local e...

In-line extraction of an ultra-stable frequency signal over an optical fiber link

Bercy, Anthony; Guellati-Khélifa, Saïda; Stefani, Fabio; Santarelli, Giorgio; Chardonnet, Christian; Pottie, Paul-Eric; Lopez, Olivier; Amy-Klein, Anne
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 06/02/2014
Relevância na Pesquisa
676.9168%
We demonstrate in-line extraction of an ultra-stable frequency signal over an optical link of 92-km of installed telecommunication fibers, following the proposition of G. Grosche in 2010. We show that the residual frequency noise at the extraction end is noticeably below that at the main link output when the extraction is near the input end, as expected from a simple model of the noise compensation. We obtain relative frequency instabilities, expressed as overlapping Allan deviation, of 8x10-16 at 1 s averaging time and a few 10-19 at 1 day. These results are at the state-of-the-art for a link using urban telecommunication fibers. We also propose an improved scheme which delivers an ultra-stable signal of higher power, in order to feed a secondary link. In-line extraction opens the way to a broad distribution of an ultra-stable frequency reference, enabling a wide range of applications beyond metrology.

Simultaneous determination of selected endocrine disrupters (pesticides, phenols and phthalates) in water by in-field solid-phase extraction (SPE) using the prototype PROFEXS followed by on-line SPE (PROSPEKT) and analysis by liquid chromatography-atmospheric pressure chemical ionisation-mass spectrometry

López-Roldán, P.; López de Alda, Miren; Barceló, Damià
Fonte: Springer Publicador: Springer
Tipo: Artículo Formato: 22195 bytes; application/pdf
ENG
Relevância na Pesquisa
381.0576%
11 pages, 4 figures, 6 tables.-- PMID: 13680063 [PubMed].-- Available online Sep 16, 2003.; In this study, a new procedure, based on on-line solid-phase extraction (SPE) and analysis by liquid-chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS), has been developed for the simultaneous, multianalyte determination of 21 selected pesticides, phenols and phthalates in water. SPE was carried out on polymeric PLRP-s cartridges by percolating 20 mL-samples. For sample preconcentration, the performance of a prototype programmable field extraction system (PROFEXS) was evaluated against the commercial laboratory bench Prospekt system used for method development. The Profexs is designed for the automated on-site sampling, SPE preconcentration, and storage of up to 16 samples in SPE cartridges. These cartridges are further eluted and on-line analyzed with the Prospekt coupled to the chromatographic system. In the optimized method, where completely on-line SPE-LC-MS analysis of the samples is carried out with the Prospekt in the laboratory, detection limits lower than 100 ng/L, and satisfactory precision (relative standard deviations <25%) and accuracies (recovery percentages >75%) were obtained for most investigated compounds from the analysis of spiked Milli-Q water. The extraction efficiency achieved with the Profexs was comparable to that of the Prospekt for most compounds and somewhat lower for the most apolar analytes...

Advantages and limitations of on-line solid phase extraction coupled to liquid chromatography–mass spectrometry technologies versus biosensors for monitoring of emerging contaminants in water

Rodríguez-Mozaz, Sara; López de Alda, Miren; Barceló, Damià
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 19968 bytes; application/msword
ENG
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19 pages, 5 tables, 1 figure.-- PMID: 17275010 [PubMed].-- Printed version published on Jun 8, 2007.; On-line solid phase extraction (SPE) coupled to liquid chromatography–mass spectrometry (LC–MS) and biosensors are advanced technologies that have found increasing application in the analysis of environmental contaminants although their application to the determination of emerging contaminants (previously unknown or unrecognized pollutants) has been still limited. This review covers the most recent advances occurred in the areas of on-line SPE–LC–MS and biosensors, discusses and compares the main strengths and limitations of the two approaches, and examines their most relevant applications to the analysis of emerging contaminants in environmental waters. So far, the on-line configuration most frequently used has been SPE coupled to liquid chromatography–(tandem) mass spectrometry. Sorbents used for on-line SPE have included both traditional (alkyl-bonded silicas and polymers) and novel (restricted access materials (RAMs), molecularly imprinted synthetic polymers (MIPs), and immobilized receptors or antibodies (immunosorbents) materials. The biosensor technologies most frequently applied have been based on the use of antibodies and...

Extraction of straight lines with subpixel precision: comparative study among three methods; EXTRAÇÃO DE FEIÇÕES RETAS COM PRECISÃO SUBPIXEL: Estudo Comparativo Entre Três Métodos

Bazan, Wimerson Sanches; Universidade Federal do Paraná; Tommaselli, Antonio Maria Garcia; Galo, Mauricio; Telles, Sandra Stephan de Souza
Fonte: Universidade Federal do Paraná-UFPR Publicador: Universidade Federal do Paraná-UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Artigo Avaliado pelos Pares Formato: application/pdf
Publicado em 12/05/2008 POR
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Nas áreas de Visão de Máquina e Fotogrametria as feições lineares extraídasde uma imagem podem ser utilizadas tanto como primitivas de umarepresentação vetorial em meio digital, quanto como controle para permitir adeterminação de elementos de orientação interior e exterior de uma câmara.Nas aplicações relacionadas à orientação de imagens, é necessário que aslinhas sejam extraídas com precisão subpixel, para garantir a confiabilidadedos parâmetros estimados. Este trabalho apresenta três abordagens paraextração de feições lineares com precisão subpixel. A primeira abordagembaseia-se no cálculo da média de posições subpixel calculadas ao longo de umperfil transversal à feição segmentada. Na segunda abordagem, ajusta-se umafunção parabólica aos tons de cinza interpolados ao longo da seçãotransversal, seguida de uma interpolação deste modelo para a determinaçãodas coordenadas subpixel do eixo da linha. Na terceira abordagem orefinamento subpixel é realizado ajustando-se uma superfície cilíndricaparabólica aos tons de cinza na vizinhança do eixo médio extraído numa etapade pré-processamento. A intersecção desta superfície com um plano normal àlinha resulta em uma parábola que permite obter o ponto crítico procurado porinterpolação. Foram realizados testes com imagens reais para comparar os métodos...