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Multi-input, multi-output system identification from frequency response samples with applications to the modeling of large space structuresMedina B., Enrique Antonio January 1991 (has links)
No description available.
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The Effect of High-Intensity Interval Training on Skeletal Muscle Oxidative Capacity in Middle-Aged Sedentary AdultsGardner, Mélanie 02 1900 (has links)
There is growing appreciation of the potential for high intensity interval training (HIT) to rapidly stimulate metabolic adaptations that resemble traditional endurance training, despite a low total exercise volume. However, much of the work has been conducted on young active individuals and the results may not be applicable to older, less active populations. In addition, many studies have employed "all out", variable-load exercise interventions (e.g., repeated Wingate Tests) that may not be safe, practical or well tolerated by certain individuals. We determined the effect of a short program of low-volume, submaximal, constant-load HIT on skeletal muscle oxidative capacity and insulin sensitivity in sedentary middle-aged individuals who may be at higher risk for inactivity-related chronic diseases. Sedentary but otherwise healthy men (n=3) and women (n=4) with a mean (±SE) age, body mass index and peak oxygen uptake (VO_2peak) of 45±2 yr, 27±2 kg-m^2 and 30±1 ml·kg^-1·min^-1 were recruited. Subjects performed 6 training sessions over 2 wk, each consisting of 10 x 1 min cycling at 60% of peak power elicited during a ramp VO_2peak test (<90% of heart rate reserve) with 1 min recovery between intervals. Needle biopsy samples (v. lateralis) were obtained before training and <72 h after the final training session. Muscle oxidative capacity, as reflected by the maximal activity and protein content of citrate synthase, increased by ~20% after training, which is similar to changes previously reported after 2 wk of Wingate-based HIT in young active subjects. Insulin sensitivity, based on fasting glucose and insulin, improved by ~35% after training. These data support the notion that low-volume HIT may be a practical, time- efficient strategy to induce metabolic adaptations that reduce the risk for inactivity-related disorders in previously sedentary adults. / Thesis / Master of Science (MSc)
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Comparing diene derivatisation methods of dry blood spot samples for vitamin D metabolites quantification by liquid chromatography-tandem mass spectrometryRapholo, Akanyang Annah Faithful January 2017 (has links)
This dissertation describes the elucidation and implementation of derivatisation
in the quantification of biologically active vitamin D metabolites in limited volume
serum and dry blood spot samples (DBS) using the liquid chromatography
tandem-mass spectrometry (LC-MS/MS) analytical technique. This manuscript
describes in detail the development and validation of an analytical methodology,
highlighting the role derivatisation and mass spectrometry plays in the structural
characterisation and quantification of vitamin D metabolites.
The first chapter reviews comprehensively, the history of vitamin D biosynthesis
discovery as an anti-rickets agent, the biochemistry of vitamin D, its metabolic
pathway, functions in the different biological systems and the consequences of
its deficiency in the body. The second chapter reviews the current methods and
techniques utilised for the detection and characterization of vitamin D
metabolites, with specific emphasis based on the contribution made by
derivatisation and mass spectrometry. A brief introduction to derivatisation is
provided, with specific focus on PTAD and Amplifex diene reagents (Cooksontype
reagents) used in this study. The importance of sensitivity and selectivity of
targeted analytes is described first in detail for underivatised analytes, followed
by PTAD and Amplifex derivatised samples. Chapter 2 also describes the importance of vitamin D quantification using liquid
chromatography, the strengths and limitations of LC-MS/MS when used in
isolation and after derivatisation. Also discussed, is how combining these
techniques can overcome inherent limitations in LCMS/MS and enhance
analytical performance. In Chapter 3 the materials and methods used and the
study design is laid out, describing a brief introduction of the routinely used clinical
diagnostics assay enzyme-linked immunosorbent assay (ELISA) as a reference
method and is compared to an LC-MS/MS assay, to ascertain discrepancies and
agreement between both methodologies from the same volunteer samples. Chapters 3 and 4 describes the comprehensive development, optimisation and
validation of the highly sensitive PTAD derivatives LC-MS/MS assay for the
quantification of active vitamin D metabolites, as well as the development of
method using Amplifex diene derivatisation. Also discussed, is sample preparation optimisation of DBS and Mitra micro-samples. A holistic approach
was taken to the development of the methodologies to provide data from which
the required analytical information can be obtained for method evaluation and
statistical analysis. The validated PTAD derivatives method is applied to the
quantification of vitamin D metabolites in limited volume (100 μL) clinical human
serum samples from 30 volunteers compared to results obtained using the clinical
diagnostics ELISA technique.
In Chapter 4 data analysis is described and the results are further discussed and
a conclusion made based on the findings from the study. This study envisaged
that combination of limited sample volume and DBS, derivatisation and LCMS/
MS is a powerful tool in vitamin D metabolite analysis and provided evidence
of a positive increase in sensitivity and selectivity between derivatised compared
to underivatised samples. A 10-fold increase in signal-to-noise-ratio (S/N) was
observed when comparing PTAD derivatised, and Amplifex diene derivatised
versus underivatised samples.
Chapter 5 presents suggested future directions and considerations in the areas
of vitamin D metabolite derivatisation and DBS sampling technique analysis using
LC-MS/MS research based on the results presented in this dissertation. / Dissertation (MSc)--University of Pretoria, 2017. / Pharmacology / MSc / Unrestricted
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Konsten att spela dator : Datorn som musikaliskt instrument ur ett sociokulturellt perspektiv / The art of playing the computer : Computer as a musical instrument from a social-cultural perspectiveMarcus, Rosengren January 2020 (has links)
Syftet med detta arbete är att fördjupa min kunskap om hur datorn kan användas som musikaliskt instrument. Datorer kan reproducera och simulera akustiska instrument men likväl kan den även skapa elektroakustiska ljud genom synthesizer och samplers. Inom det moderna musikskapandet är datorn ett ytterst viktigt instrument där den bland annat fungerar som dokumentationsmaskin, det vill säga vår tids bandspelare. Andra användningsområden av datorn i dagens musiklandskap är i ”live-framträdanden”. Med detta arbete vill jag praktisera och fördjupa mina kunskaper om hur datorn kan användas som instrument i mitt eget musicerande. Genom dokumentation i form av loggbok, video och ljudinspelningar kommer jag att analysera min process med avstamp inom det sociokulturella perspektivet. / The purpose of this work is to deepen my knowledge of how the computer can be used as a musical instrument. Computers can reproduce and simulate acoustic instruments but still they can also create electroacoustic sounds through synthesizers and samplers. In modern music creation, the computer is an extremely important instrument where, among other things, it serves as a tape-machine, the tape recorder of our time. Other uses of the computer in today's music landscape are in "live performances". With this work I want to practice and deepen my knowledge of how the computer can be used as an instrument in my own music making. Through documentation in the form of logbook, video and audio recordings, I will analyze my process with an starting point in the socio-cultural perspective.
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Characterization of proteins found in serum and sputum samples from ventilator associated pneumonia patientsYenuga, Hima Priya 29 May 2020 (has links)
No description available.
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Automated sputum screening using the BD FocalPointTM Slide Profiler : correlation with transbronchial and transthoracic needle aspirates in a high risk populationNeethling, Greta Sophie 04 1900 (has links)
Thesis (MMed)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Background:
Sputum is a non-invasive, economic investigation whereby bronchogenic carcinoma
can be identified. Manual cytological screening is labour intensive, time-consuming
and requires a continuous high level of alertness. Automation has recently been
successfully introduced in gynaecological cytology. Since sputum samples are similar
to cervical smears, the question arises as to whether they are also suitable for
automated screening.
Objective:
This study presented with various objectives: 1) To test automated sputum screening
using the BD FocalPoint™ Slide Profiler (FP) and compare with manual sputum
screening. 2) To determine the sensitivity and specificity of sputum in identification of
bronchogenic carcinoma. 3) To ascertain if any clinical, radiological or bronchoscopy
findings would be predictors for bronchogenic carcinoma. 4) To determine the
significance of adequacy.
Method: Sputum samples were collected prospectively from patients attending the Division of
Pulmonology at Tygerberg hospital for a transbronchial fine needle aspiration biopsy
(TBNA) or a transthoracic fine needle aspiration biopsy (TTNA) for the period from
2010 to 2012. A pre-bronchoscopy sputum was collected and submitted for
processing. Stained slides were put through the FP for automated screening. After
slides were qualified, sputum slides were put back in the routine screening pool.
Correlation was done using the TBNA/TTNA result as the standard to evaluate the
sputum results. Results:
108 sputum samples were included in this study. Of the 84.3% malignant (n=91) and
15.7% benign (n=17) cases confirmed with a diagnostic procedure, sputum cytology
had a sensitivity of 38.5% (35/91 malignant cases), and a specificity of 100% (17/17
benign cases). Automated screening had a better sensitivity of 94.3% (33/35 positive
sputum cases), while manual screening showed a sensitivity of 74.3% (26/35 positive
sputum cases) when compared to the final sputum result.
Individual parameters with a significant association with positive sputum included the
presence of an endobronchial tumour, partial airway obstruction / stenosis, round
mass, spiculated mass (negative association), loss of weight (negative association)
and squamous cell carcinoma as the histological subtype. Adequacy was not as
significant as hypothesised since 85.3% of true positive sputum, but also 65.5% of
false negative sputum, had large numbers of alveolar macrophages present.
Conclusion:
Sputum cytology remains an important part of the screening programme for
bronchogenic carcinoma in the public health sector of South Africa. Results confirm
that sputum cytology is very specific, and automated screening improves sensitivity.
Automated screening proved to be more time efficient, resulting in 83.1% reduction
(p<0.0001) in the screening time spent per case by a cytotechnologist.
Results confirm that the quantity of alveolar macrophages is not directly proprtional to
pathology representation. Positive sputum results did however improve with sputum
adequacy, but had no significant association.
Recommendations from this study include adopting automated sputum screening. / AFRIKAANSE OPSOMMING: Agtergrond:
Die verkryging van ‘n sputummonster is ‘n nie-indringende, ekonomiese ondersoek
waardeur bronguskarsinoom identifiseer kan word. Nie-geoutomatiseerde sitologiese
ondersoek is arbeidsintensief, tydrowend en vereis ‘n deurlopende hoë vlak van
konsentrasie en fokus. Outomatisering is onlangs suksesvol geïmplementeer in
ginekologiese sitologie-ondersoeke. Aangesien sputummonsters soortgelyk aan
servikale monsters is, het die vraag ontstaan of sputummonsters ook geskik sou
wees vir geoutomatiseerde sifting.
Doelwit:
Hierdie studie het verskeie doelwitte gehad: 1) Om geoutomatiseerde sifting van
sputummonsters te toets deur gebruik te maak van BD Focal Point ™ Slide Profiler
(FP), en te vergelyk met nie-geoutomatiseerde sputum sifting. 2) Om die sensitiwiteit
en spesifisiteit van sputum in die identifikasie van bronguskarsinoom te bepaal. 3)
Om vas te stel of enige kliniese, radiologiese of brongoskopiese bevindings
bronguskarsinoom sou kon voorspel. 4) Om die belang van ‘n verteenwoordigende
monster te bepaal.
Metode:
‘n Prospektiewe studie van die pasiënte wat die Divisie van Pulmonologie by
Tygerberg Hospitaal vir transbrongiale nodale aspirasie (TBNA) of ‘n transtorakale
aspirasie (TTNA) vanaf Julie 2010 tot Mei 2012 bygewoon het, is gedoen. ‘n Prebrongoskopiese
sputum is geneem en gestuur vir prosessering. Die gekleurde
skuifies is deur die FP gestuur vir geoutomatiseerde ondersoek. Indien die
sputumskuifies gekwalifiseer het vir geoutomatiseerde sifting, is hulle in die groep vir
ondersoek ingesluit. ‘n Korrelasiestudie, om die sputumresultate te evalueer, is
uitgevoer deur die TBNA/TTNA bevindings as standaard te gebruik. Resultate:
Vir hierdie studie is 108 sputummonsters ingesluit. Vanuit die 84.3% maligne (n=91)
en 15.7% benigne (n=17) gevalle, bevestig deur ‘n diagnostiese prosedure, het
sputumsitologie ‘n sensitiwiteit van 38.5% (35/91 maligne gevalle) en ‘n spesifisiteit
van 100.0% (17/17 benigne gevalle), getoon. Geoutomatiseerde sifting het ‘n beter
sensitiwiteit met 94.3% (33/35 maligne gevalle), terwyl nie-geoutomatiseerde
(ondersoek) ‘n sensitiwiteit van 74.3% (26/35 maligne gevalle) wanneer met die finale
resultaat vergelyk, gevind.
Individuele parameters met ‘n betekenisvolle assosiasie het die teenwoordigheid van
‘n endobrongiale tumor, gedeeltelike lugwegobstruksie / stenose, ronde massa, ‘n
spekuleerde massa (negatiewe assosiasie), gewigsverlies (negatiewe assosiasie) en
plaveiselkarsinoom as die histologiese subtipe, ingesluit. Geskiktheid van die
monster was nie so betekenisvol as wat in die hipotese gestel is nie: aangesien
85.3% van ware positief gediagnoseerde sputummonsters, maar ook 65.5% van die
vals negatiewe sputummonsters, groot hoeveelhede alveolêre makrofae ingesluit het.
Gevolgtrekking:
Sputumsitologie bly steeds ‘n belangrike deel van die siftingsprogram vir
bronguskarsinoom in die openbare gesondheidssektor in Suid-Afrika. Resultate van
hierdie studie bevestig dat sputumsitologie baie spesifiek is en dat geoutomatiseerde
sifting die sensitiwiteit verbeter. Ge-outomatiseerde sifting het bewys dat dit meer
tydsbesparend is, met ‘n 83.1% vermindering (p<0.0001) in die siftingstyd wat deur
een sitotegnoloog per geval bestee word.
Resultate het bevestig dat die hoeveelheid alveolêre makrofae nie direk
proporsioneel verwant is tot die patologie nie. Hoe meer verteenwoordigend die
sputummonster was, hoe groter was die kanse om ‘n akkurate positiewe diagnose te
maak. Die assosiasie van die geskiktheid van die sputummonster en die positiewe
resultate het egter nie ‘n statisties betekenisvolle resultaat getoon nie.
Aanbevelings vir hierdie studie sluit in die aanwending van geoutomatiseerde
sputumondersoeke.
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Application of Mitochondrial DNA Analysis in Contemporary and Historical SamplesLembring, Maria January 2013 (has links)
The mitochondrion is a tiny organelle that is the power supplier of the cell and vital to the functioning of the body organs. Additionally it contains a small circular genome of about 16 kb, present in many copies which makes the mitochondrial DNA more viable than nuclear DNA. Mitochondrial DNA is also maternally inherited and thus provides a direct link to maternal relatives. These two properties are of particular use for forensic samples, which only contain limited or degraded amounts of DNA, and for historical samples (ancient DNA). This thesis presents work on the mitochondrial DNA in the hypervariable regions (HV) I and II, in both contemporary and historical samples. Forensic genetics makes use of mitochondrial DNA analysis in court as circumstantial evidence, and population databases are used for the calculation of evidence value. Population samples (299) across Sweden have been analysed in order to enrich the EDNAP mtDNA database (EMPOP) (paper I). The application of mitochondrial DNA analysis allowed for analysis of historical skeletal remains: Copernicus, 1473-1543 (paper II), Karin Göring, 1888-1931 (paper III) and Medieval bones, 880-1000 AD, from a mass grave found in Sigtuna, Sweden (paper IV). The thesis also includes analyses of bones and teeth from the shipwrecked crew of the Vasa warship, 1628, samples from the Vasa museum, Stockholm, Sweden (paper V). Overall, the varying age of the samples and the different conservation environments (soil and water) accounted for variations in quality, but still allowed for successful DNA analysis.
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[en] DEVELOPMENT OF ANALYTICAL METHODS FOR TRACE ELEMENTS DETERMINATIONS IN OILY AND VISCOUS SAMPLES BY ICP OES E ICP-MS / [pt] DESENVOLVIMENTO DE MÉTODOS ANALÍTICOS PARA DETERMINAÇÃO DE ELEMENTOS-TRAÇO EM AMOSTRAS OLEOSAS E PASTOSAS POR ICP OES E ICP- MSROSELI MARTINS DE SOUZA 25 September 2007 (has links)
[pt] Métodos de análise para determinação de elementos-traço em
amostras oleosas
e pastosas são necessários, por exemplo, no caso do
petróleo e em suas frações mais
pesadas, para os quais os elementos-traço indicam
características do tipo do petróleo,
correlacionando-o com a localização geográfica da jazida.
Além disso, a
quantificação destes elementos tem utilidade nas
interpretações geoquímicas
relacionadas com maturidade térmica, correlação óleo-óleo
e migração primária e
secundária do óleo e na obtenção de informações que
permitem a criação de
estratégias para realizar o refino do óleo, prevenindo
contaminação dos catalisadores,
corrosão de equipamento e potencial dano ambiental. No
caso de óleos e gorduras
vegetais, a presença destes elementos, mesmo em baixas
concentrações ((mi)g g-1), pode
acelerar processos oxidativos que geram peróxidos,
aldeídos, cetonas, ácidos e
epóxidos, que além de causarem a rancidez prematura dos
óleos produzem efeitos
patológicos no sistema digestivo e potencializam a ação de
alguns carcinogênicos. As
técnicas espectrométricas baseadas no uso do plasma (ICP
OES e ICP-MS) estão
entre as mais utilizadas na determinação de elementos-
traço nesses tipos de amostra.
Porém, os procedimentos de preparação de amostra mais
tradicionalmente usados são
os que destroem a matriz das amostras, solubilizando-as em
ácidos inorgânicos fortes.
Neste trabalho, novas estratégias de preparação de
amostras de petróleo, óleo diesel,
asfaltenos, óleos comestíveis, manteiga e margarina foram
desenvolvidas visando à
utilização do tradicional procedimento de nebulização de
solução para introdução de
amostra no plasma. No caso do óleo diesel, a estratégia
avaliada foi a de preparação
de amostras na forma de emulsão com n-propanol. Nesse
caso, um planejamento
fatorial indicou que fatores importantes para a
determinação de elementos refratários
foram tanto a massa de amostra na composição da emulsão
(até 25% em massa)
quanto a acidificação da emulsão. As amostras de óleo cru,
óleos vegetais e gorduras
vegetais foram preparadas como microemulsão em n-propanol.
Alternativamente, um procedimento de extração assistida
por ultra-som foi desenvolvido. A emulsão de
óleo cru com n-propanol mostrou ser um bom meio de
estabilização dos analitos em
solução. No caso da extração ácida assistida por ultra-som
para óleo cru, um
planejamento fatorial mostrou que os fatores importantes
para a determinação de
elementos-traço foram, o tempo de aquecimento da amostra,
a concentração do ácido
nítrico e a exposição ao ultra-som. Para as amostras de
óleos e gorduras vegetais, a
otimização das proporções de componentes na emulsão com n-
propanol proporcionou
boa estabilidade e homogeneidade das amostras de óleo de
oliva e óleo de soja (6 %
em massa de óleo) e para margarina e manteiga (5 % m/m de
óleo). Para o método da
extração ácida assistida por ultra-som, as condições
otimizadas para a preparação da
amostra permitiram também a análise por ICP-MS, cujos
resultados são discutidos e
comparados com os resultados obtidos por ICP OES. Para as
amostras de asfaltenos,
o procedimento proposto foi o de extração em HNO3
concentrado assistida por ultrasom.
Nesse caso, os mesmos parâmetros otimizados para o óleo
cru foram usados. Os
parâmetros operacionais foram otimizados para obtenção dos
parâmetros de mérito,
sendo a aplicação dos métodos propostos confirmada por
testes de recuperação além
de comparação com resultados obtidos com procedimentos
tradicionais para esse tipo
de amostra. Assim, nessa tese, foram desenvolvidos métodos
para a determinação de
Cr, Mo, V e Ti em óleo diesel e em óleo combustível, Cd,
Co, Cr, Fe, Mn, Mo, Ni,
Ti, V e Zn em óleo cru, Fe, Ni e V em asfaltenos. Cd, Co,
Cr, Cu, Mn e Ni foram
determinados em óleos e gorduras comestíveis utilizando
preparação de amostra
como microemulsão em n-propanol. Já Al, Ca, Cd, Cu, Fe,
Mg, Mn, Ni, V e Zn foram
determinados após extração ácida assistida por / [en] Analytical methods for the determination of trace elements
in oily and viscous
samples are necessary, for example, in the case of crude
oil and its heavy fractions,
where trace elements indicate specific oil characteristics
and the geographic location
of the natural deposit. Moreover, the quantification of
these elements is relevant for
geochemical interpretations concerning thermal maturity,
oil-oil correlations and
primary and secondary oil migration. Knowledge on trace
element characteristics of
crude oil is also important in oil refining strategies to
prevent contamination of
catalysts as well as equipment corrosion, and to minimize
environmental pollution. In
the case of vegetal oils and fats, the presence of certain
elements, even in low
concentrations ((mi)g g-1); can speed up oxidative
processes and premature rancidity of
oils, which may cause pathological effects in the
digestive system, including cancer.
Spectrometric techniques based on inductively coupled
plasma (ICP OES and ICPMS)
are extensively used for determination of trace elements
in such type of samples
due to their sensitivities and multielemental features. In
the case of oils and fats, the
samples have to be generally decomposed by wet-ashing
procedures with mineral
acids, prior to the elemental determinations. In this
work, new strategies for sample
preparation of crude oil, diesel, asphaltenes, edible
oils, butter and margarine have
been developed, which allow the use of the traditional
procedure for sample
introduction into the ICP by solution nebulization. In the
case of diesel oil, the
proposed strategy was the preparation of samples as
emulsions with n-propanol.
Factorial design studies showed that the important factors
for the quantitative
determination of refractory metals were the sample amount
in the emulsion (up to
25% in weight) and the acidification of the emulsion.
Crude oil samples, vegetable
oils and fats have been prepared as n-propanol
microemulsions. Alternatively, an
ultrasound-assisted trace metal extraction procedure was
developed. The crude oil
emulsions with n-propanol were found to be a good
environment to keep the analytes
in solution. In the case of the ultrasound-assisted acid
extraction for crude oil, a factorial design indicated
that the important factors for the determination of trace
elements have been the sample heating time, the nitric
acid concentration and the
ultrasound exposure time. For vegetable oils and fats, the
optimization of the npropanol
emulsion components provided good stability and
homogeneity olive and
soy oils (6 % of oil in weight) and for margarine and
butter (5 % of oil in weight). For
the ultrasound-assisted acid extraction, the optimized
conditions for sample
preparation also allowed the analysis of the extracts by
ICP-MS, which results were
compared with the ones obtained by ICP OES. For asphaltene
samples, the proposed
procedure was the ultrasound- assisted acid extraction in
concentrated HNO3 using
similar conditions employed for crude oil. The figures of
merit for the proposed
methods were achieved under optimized experimental and
instrumental conditions
and validations were performed by analysis of certified
reference materials (when
available), recovery tests, and by comparison of results
obtained using traditional
sample preparation procedures for this type of sample.
Methods for the determination
of Cr, Mo, V and Ti in fuel and diesel oils, for Cd, Co,
Cr, Fe, Mn, Mg, Ni, Ti, V and
Zn in crude oil and for Fe, Ni and V in asphaltenes have
been developed. Cd, Co, Cr,
Cu, Mn and Ni in edible oils and fats have been determined
using the microemulsification
in n-propanol, while Al, Ca, Cd, Cu, Fe, Mg, Mn, Ni, V and
Zn have
been determined after acid extraction in HNO3. The
analyses were carried out by
using the external calibration method with internal
standardization by Sc (in the case
of ICP OES). The ultrasound-assisted acid extraction
method for t
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DESENVOLVIMENTO DE UM SIMPLES E NOVO SENSOR PARA FLUTAMIDA À BASE DE NANOTUBOS DE CARBONO OXIDADO E ÓXIDO DE GRAFENO: APLICAÇÃO EM AMOSTRAS DE URINA ARTIFICIAL E FORMULAÇÕES FARMACÊUTICAS / DEVELOPMENT OF A NEW AND SIMPLE SENSOR FOR FLUTAMIDE TO BASE OXIDIZED CARBON NANOTUBES AND GRAPHENE OXIDE: APPLICATION IN ARTIFICIAL URINE SAMPLES AND PHARMACEUTICAL FORMULATIONSFARIAS, Julianna Santos 06 March 2017 (has links)
Submitted by Maria Aparecida (cidazen@gmail.com) on 2017-04-12T15:30:06Z
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Juliana Santos Farias.pdf: 1234303 bytes, checksum: 420e49b91acb05fb1346e95075411509 (MD5) / Made available in DSpace on 2017-04-12T15:30:06Z (GMT). No. of bitstreams: 1
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Previous issue date: 2017-03-06 / CAPES, FAPEMA,CNPQ / This paper describes the development of a simple and new sensor
electrochemical determination of flutamide in voltamétrica formulations
pharmaceutical and artificial urine specimens using a carbon electrode
vitreous (ECV) modified with oxidized carbon nanotubes and graphene oxide
(NCO-OG), which was named ECV/NCO-OG. Electronic microscopy techniques
scanning (SEM) and Raman Spectroscopy were used for the
characterization of carbon based materials. The electrochemical response of the analyte
front of the ECV/NCO-OG was investigated by cyclic voltammetry techniques
(VC) and square wave voltammetry (VOQ). The sensor exhibited a high activity
eletrocatalítica for the reduction of flutamide in 0.05 V vs. Ag/AgCl. The parameters
experimental influence the response of the electrode was investigated and the
optimum conditions were found for the electrode modified with NCO-OG, in
Britton-Robinson buffer solution-BR on concentration of 0.1 mol L-1 (pH 5). The
proposed sensor presented a wide range of linear response of concentration
for the flutamide of 0.1 to 1000 µmol L-1 (or µ g L-1 27.6 to 0.27 g L-1) for n = 15
(R2 = 0.997), limit of detection (LOD), limit of quantification (LOQ), and
sensitivity of 0.03 µmol L-1, 0.1 µmol L-1, and 0.30 µmol µA -1 L, respectively. The
ECV/NCO-OG was successfully applied to the determination of flutamide in
pharmaceutical formulations used in the treatment of prostate cancer and
artificial urine samples. The results obtained with the proposed sensor were
compared with the method described in the literature and showed a level of
95% confidence, demonstrating that there is no statistical difference between the method of
reference and the method proposed. The addition and recovery studies show that the
proposed method presents a satisfactory accuracy with average value of
101% recovery ( 1)%. for the fortified samples. / Este trabalho descreve o desenvolvimento de um simples e novo sensor
eletroquímico para determinação voltamétrica de flutamida em formulações
farmacêuticas e amostras de urina artificial empregando um eletrodo de carbono
vítreo (ECV) modificado com nanotubos de carbono oxidado e óxido de grafeno
(NCO-OG), o qual foi denominado ECV/NCO-OG. As técnicas microscopia eletrônica
de varredura (MEV) e a Espectroscopia Raman foram utilizadas para a
caracterização dos materiais à base de carbono. A resposta eletroquímica do analito
frente ao ECV/NCO-OG foi investigada através das técnicas de voltametria cíclica
(VC) e voltametria de onda quadrada (VOQ). O sensor exibiu uma alta atividade
eletrocatalítica para a redução da flutamida em 0,05 V vs Ag/AgCl. Os parâmetros
experimentais que influenciam a resposta do eletrodo foram investigados e as
condições ótimas foram encontradas para o eletrodo modificado com NCO-OG, em
solução tampão Britton-Robinson-BR na concentração de 0,1 mol L-1 (pH 5). O
sensor proposto apresentou uma ampla faixa de resposta linear de concentração
para a flutamida de 0,1 a 1000 µmol L-1 (ou 27,6 µg L-1 a 0,27 g L-1) para n=15
(R2=0,997), com limite de detecção (LOD), limite de quantificação (LOQ), e
sensibilidade de 0,03 µmol L-1, 0,1 µmol L-1, e 0,30 µA µmol-1 L, respectivamente. O
ECV/NCO-OG foi aplicado com sucesso para a determinação de flutamida em
formulações farmacêuticas utilizadas no tratamento de câncer de próstata e
amostras de urina artificial. Os resultados obtidos com o sensor proposto foram
comparados com o método descrito na literatura e observou-se um nível de
confiança de 95%, demonstrando que não há diferença estatística entre o método de
referência e o método proposto. Os estudos de adição e recuperação mostram que o
método proposto apresenta uma exatidão satisfatória com valor médio de
recuperação de 101% ( 1) %. para as amostras fortificadas.
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Vergleich verschiedener Methoden zur Identifizierung Paratuberkulose–positiver RinderherdenKube, Julia 03 June 2014 (has links) (PDF)
Ziel der vorliegenden Arbeit war es, Screening–Methoden zu prüfen, um auf einfache, kostensparende Weise und mit ausreichender statistischer Sicherheit festzustellen, ob der Erreger der Paratuberkulose (Mycobacterium avium ssp. paratuberculosis) in einer Herde vorhanden ist oder nicht. Dazu wurden zwei auf dem kulturellen Erregernachweis beruhende Verfahren, die Untersuchung individueller Kotproben auf der Basis von Stichproben und die Untersuchung von Umgebungskotproben, einem serologischen Untersuchungsansatz, dem Nachweis von MAP–Antikörpern nach Aufkonzentrierung in gepoolten Einzelmilchproben, gegenübergestellt. Als Referenzmethode diente die kulturelle Einzeltieruntersuchung aller über 24 Monate alten Tiere des jeweiligen Bestandes.
In 20 Thüringer Milchviehherden mit bekannter Einzeltierprävalenz wurden 5063 Einzeltierkotproben, 200 Umgebungskotproben und 262 aufkonzentrierte Milchpools aus 4337 laktierenden Rindern untersucht. Zusätzlich wurde eine systematische retrospektive Stichprobenkalkulation (nStichprobe = 1458 Einzeltierkotproben) vorgenommen. Die Kultivierung der Einzeltierkotproben und der Umgebungskotproben erfolgte über 12 Wochen auf HEYM–Nährmedium mit anschließender Speziesidentifizierung durch PCR und Ziehl–Neelsen–Färbung. Die Umgebungskotproben wurden zu zwei Untersuchungszeitpunkten (Frühjahr und Sommer) an jeweils fünf Lokalisationen eines Betriebes entnommen: Abkalbebereich, Melkbereich einschließlich Vorwartehof, Laufbereich, Haupttriebweg, Übergang zum Kälberbereich. Die Untersuchung der Milchpools erfolgte nach vorheriger Aufkonzentrierung mittels zweier verschiedener ELISAs.
Im Frühjahr entnommene Umgebungskotproben aus 16 MAP–positiven Betrieben detektierten das Vorhandensein des Erregers in neun Betrieben (56,3 %). Betriebe mit einer Einzeltierprävalenz von über 4,5 % wurden in neun von zehn Fällen (90 %) sicher erkannt. Im Sommer entnommene Umgebungskotproben fielen durch eine sehr starke Kontamination auf. Von den 16 MAP–positiven Beständen wurden 15 Herden (93,7 %) mittels Stichprobenuntersuchung als Bestand mit Paratuberkulosevorkommen identifiziert, wobei lediglich ein Bestand mit einer Einzeltierprävalenz von 0,49 % nicht detektiert wurde. Die serologische Untersuchung der Milchpools lieferte keine verwendbaren Ergebnisse.
Mit Hilfe der Untersuchung von Umgebungskotproben lassen sich Herden mit einer durch kulturelle Untersuchung ermittelten Einzeltierprävalenz von 4,5 % und darüber mit hinreichender Sicherheit auffinden. Bei der Bewertung dieses Schwellenwertes ist zu beachten, dass bei Verwendung von nur einem Kulturröhrchen je Kotprobe von einer Sensitivität der Methode von 60 % im Vergleich zur Verwendung von drei Kulturröhrchen auszugehen ist. Für eine Überwachung unverdächtiger Herden ist die Sensitivität dieses Untersuchungsansatzes jedoch zu gering. Die individuelle kulturelle Untersuchung einer Stichprobe zeigte eine ausreichend hohe Sensitivität, um bei der Überwachung größerer unverdächtiger Herden eingesetzt werden zu können.
Ein Einsatz serologischer Milchuntersuchung ist zur Bewertung von Beständen zur Ermittlung des MAP–Infektionsstatus gegenwärtig nicht zu empfehlen. Für die Überwachung größerer, als Paratuberkulose–unverdächtig anerkannter Bestände ist somit ein wechselnder Einsatz von Einzeltierkotproben aller Rinder über 24 Monaten und einer aussagekräftigen systematischer Stichprobenuntersuchung möglich und trägt damit zur Erleichterung der derzeit noch zeit– und kostenintensiven Paratuberkulose–Diagnostik bei.
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