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Tillgängligt mode för alla? : Hur kvinnor upplever och hanterar storleksexkludering / Available fashion for everyone? : How women experience and handle size exclusionOrvo, Jennifer, Sjöberg, Fanny, Linnéa Koch, Emelie January 2022 (has links)
Idag pågår en diskussion om huruvida en typ av konsumenter exkluderas i modeindustrin och möjligheterna kring att få en bredare inkludering av större storlekar och varierande kroppstyper i modebranschen. Tidigare studier som har utförts på kvinnor med större storlek visar att det finns stora svårigheter att kunna visa upp och vara sitt sanna jag när det normativa modet och samhället inte tillåter det. Syftet med denna studie är att undersöka vilka praktiker som upplevs vara exkluderande och hur dessa hanteras. Forskningsfrågorna är: Vilka praktiker uppfattas som exkluderande av konsumenter?, och Hur hanterar konsumenten de identifierade exkluderingspraktikerna? Studiens teoretiska ramverk är baserat på begreppen exkludering, rutin och shopping som praktik från praktikteorin. Denna studie grundar sig i en kvalitativ forskningsmetod med en insamling av semistruktuerade intervjuer vilka är centrala för att fylla studiens syfte. Urvalet består av 10 kvinnor med storlekarna 44-54 i åldrarna 21-55, som ger en övergripande bild av olika upplevelser. Resultatet utgår från en matris som identifierar exkluderingspraktiker inom 4 olika teman som upplevs av konsumenten: (1) fysisk butik, (2) utbud & sortiment, (3) kategorisering och (4) marknadsföring. Resultatet visar att samtliga respondenter har upplevt storleksexkludering och hanterar det främst genom att bojkotta företag som exkluderar och handlar online. De likheter diskussionen fastställer mellan tidigare forskning och denna studie är att större storlekar har ett begränsat utbud och att designen skiljer sig från ordinarie sortiment. En exkluderingspraktik som tidigare studier inte har uppmärksammat är att konsumenterna med större storlekar har begränsade möjligheter till att vara hållbara konsumenter. Avslutningsvis bidrar studien med en sammanställning av tidigare forskning samt tillämpning av nya infallsvinklar. Den bidrar med förståelse till vilka praktiker konsumenten upplever som exkluderande och hur företagen påverkas av det. Samt vetskap om att det finns en köpstark och outnyttjad konsumentgrupp. De begränsningar som studien innefattar är att den yngre och äldre målgruppen inte undersöks, samt att studien enbart utgår från den kvinnliga marknaden. Eftersom denna studie undersöker den kvinnliga modemarknaden i åldrarna 20-55 år, är förslag för vidare forskning att studera den manliga modemarknaden för att bidra till en förändrad och mer inkluderande modeindustri för fler människor. / Today, there is a discussion about whether one type of consumer is excluded in the fashion industry and the possibilities of getting a broader inclusion of larger sizes and varying body types in the fashion industry. Previous studies that have been conducted on women of larger sizes show that there are great difficulties in being able to be their true selves when normative fashion and society do not allow it. The purpose of this study is to investigate which practices are perceived to be exclusive and how these are handled. The research questions are: Which practices are perceived as excluding consumers?, and How does the consumer handle the identified exclusion practices? The study's theoretical framework is based on the concepts of exclusion, routine and shopping as practice from the practice theory. This study is based on a qualitative research method with a collection of semi-structured interviews which are central to fulfilling the purpose of the study. The selection consists of 10 women with sizes 44-54 aged 21-55, which gives an overview of different experiences. The result is based on a matrix that identifies exclusionary practices within 4 different themes experienced by the consumer: (1) physical store, (2) supply & assortment, (3) categorization and (4) marketing. The results show that all respondents have experienced size exclusion and deal with it mainly by boycotting companies that exclude and shop online. The similarities the discussion establishes between previous research and this study are that larger sizes have a limited range and that the design differs from the regular assortment. An exclusionary practice that previous studies have not noticed is that consumers with larger sizes have limited opportunities to be sustainable consumers. Finally, the study contributes with a compilation of previous research and the application of new approaches. It contributes to an understanding of which practices the consumer perceives as exclusive and how companies are affected by it. As well as knowledge that there is a strong and unreached consumer group. The limitations which the study includes are that the younger and older target group is not examined, and that the study is only based on the female market. As this study examines the female fashion market between the ages of 20-55, the proposal for further research is to study the male fashion market to contribute to a changing and more inclusive fashion industry for more people.
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How much can the cross-linking of chromatographic media affect the porosity? / Hur mycket påverkar tvärbindningen porositeten i den kromatografiska stationära fasen?Östling, Carl January 2022 (has links)
Vätskekromatografi är vanligt förekommande metod för separationer av molekyler inom bioteknik. Det finns inom begreppet vätskekromatografi många olika tekniker och vilken specifik teknik som är mest lämplig för en given separation beror på egenskaperna hos den avsedda målmolekylen. Egenskaper för vilka målmolekyler kan separeras är bland annat storlek, laddning och affinitetsintreaktioner. Porositeten är i den stationära fasen en avgörande egenskap, eftersom porernas tillgänglighet påverkar den stationära fasens tillgängliga yta. Således är förmågan att bestämma porositeten en avgörande aspekt vid tillverkningen av den stationära fasen. Agaros utgör ofta den stationära fasen, på grund av modifieringsmöjligheterna hos polysackaridkedjorna. Bio-Works Workbeads 40/1000 SEC är agarbaserade pärlor för den stationär fas i storleksutslutningskromatografi. Pärlorna är tvärbundna två gånger för att få tillräcklig styvhet och för att uppnå en önskad fördelningskoefficient. Det första tvärbindningssteget bestämmer strukturen på pärlorna och därmed porositeten, medan det andra tvärbindningssteget försäkrar att pärlorna får tillräcklig styvhet. För produkten Workbeads 40/1000 är de önskade fördelningskoefficienterna mellan 0,2-0,35 för thyroglobulin, 0,62-0,75 för albumin (från äggvita) och 0,85-0,95 för ribonukleas A. För att bestämma förhållandet mellan koncentrationerna av reaktanterna NaOH och allylbromid i den första tvärbindningen och de resulterande egenskaperna hos den stationära fasen (fördelningskoefficienter, styvhet och porstorlek) ändrades koncentrationerna av reaktanterna i den första tvärbindningen. Samtliga resulterande pärlorna med de ändrade koncentrationerna analyserades med hjälp av en ÄKTAexplorer. Pärlornas styvhet bestämdes genom att analysera kraschflödet i den packade bädden. Det fanns inga tecken på några skillnader mellan de tillverkade pärlproverna. De icke-specifika interaktionerna analyserades genom att jämföra fördelningskoefficienterna i en standard PBS-buffert med en hög saltkoncentrationsbuffert. Polaritetsförändringen i den mobila fasen kan påverka de icke-specifika interaktionerna eftersom hydrofobiska interaktioner då främjas. Fördelningskoefficienternas kurvor jämfördes också för att analysera likheter och skillnader för olika proteiner. Skillnader i formen på fördelningskoefficientkurvorna kan innebära att porstorleken inte är den enda bidragsfaktorn till skillnaderna i fördelningskoefficienterna. Därför kan skillnaden innebära effekter av icke-specifika interaktioner och det fanns det indikationer på att vissa icke-specifika interaktioner uppstod mellan proteinerna och agarpärlorna. Det finns dock ingen skillnad mellan de pärlor med många tvärbindningar och de med få tvärbindningar. Porstorleken och porstorleksdistribution bestämdes genom att använda en uppsättning dextran med inverterad storleksutslutningskromatografi. Efter varje tvärbindningsreaktioner bestämdes antalet bildade tvärbindningar genom titrering med silvernitrat. Det visade sig att koncentrationen av allylbromid hade en större inverkan på de resulterande egenskaperna jämfört med koncentrationen av NaOH. En ökad koncentration av allylbromid visade på ett ökat antal bildade tvärbindningar. Experiment med många bildade tvärbindningar visade sig ha en större porstorlek och högre fördelningskoefficienten jämfört med experiment med lägre mängd bildade tvärbindningar. / Liquid chromatography is a method that is extensively used for separations in biotechnology at present. There are many different techniques within the concept of liquid chromatography and which specific technique that is most suitable depends on the properties of the intended target molecule. Properties for which target molecules can be separated are among others, size, charge, and affinity interactions. The porosity is a crucial property of the chromatographic resin, as the accessibility of pores determines the accessible surface area of the resin. Thus, the ability to determine the porosity is a crucial aspect in the manufacturing of the resin. Agarose often constitutes the chromatographic resin, due to the modification possibilities of the polysaccharide chains. Bio-Works Workbeads 40/1000 SEC are agar-based size exclusion chromatography beads. The beads are cross-linked twice in order to obtain sufficient rigidity and to achieve a desired distribution coefficient. The first cross-linking step determines the structure of the beads thereby stets the porosity and the second cross-linking step ensures a sufficinet rigidity. For the product Workbeads 40/1000 the desired distribution coefficients is between 0.2-0.35 for thyroglobulin, 0.62-0.75 for albumin (from egg white) and 0.85-0.95 for ribonuclease A. To determine the relation between the concentrations of two reactants NaOH and allyl bromide in the first cross-linking step and the resulting properties of the resin (distribution coefficients, rigidity, and pore size), the concentrations in the first cross-linking were changed. All resulting beads with the altered reactant concentrations were analyzed using an ÄKTAexplorer. The rigidity of the beads was determined by analyzing the crash flow rate of the packed bed. There were no indications of any differences between the manufactured resin samples. The non-specific interaction was analyzed by comparing the distribution coefficients in a standard PBS buffer to a high salt concentration buffer. The polarity change in the mobile phase might affect the non-specific interactions since hydrophobic interactions would be promoted. The distribution coefficient curves were also compared for similarities and differences between different proteins. Differences in the shape of the distribution coefficient curves might imply that the pore size is not the only contribution factor to the distribution coefficient differences. Hence, the difference might imply the effect of non-specific interactions. It was indicated that some non-specific interactions occurred between the proteins and the agar beads. However, there was no difference between beads of varying cross-linking degree. The porosity and pore size distribution were determined by utilizing a set of dextran’s with Inverse Size Exclusion Chromatography (ISEC). After each cross-linking step the number of cross-links was determined by titration with silver nitrate (AgNO3). It was shown that the concentration of allyl bromide had a greater impact on the resulting properties compared to the concentration of NaOH. An increased concentration of allyl bromide showed increased number of formed cross-links. Experiments with many formed cross-links was shown to have a larger pore size and higher distribution coefficient Kd compared to experiments with lower amount of formed cross-links.
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Synthesis and Characterization of Poly(2-Ethyl-2-Oxazoline) Functional Prepolymers and Block CopolymersCelebi, Oguzhan 19 January 2014 (has links)
This dissertation focuses on the synthesis and characterization of functional poly(2-ethyl-2-oxazoline) (PEtOx) containing homo- and block copolymers that are potential materials for membrane-based water purification and gas separation, drug delivery, magnetic resonance imaging and tissue engineering applications.
The polymerization of 2-ethyl-2-oxazoline (EtOx) was investigated with regard to the effects of initiator structures and reaction parameters such as polymerization time and temperature on molecular weight control and molecular weight distribution, endgroup functionality, living characteristics, and mechanism and kinetics. The structure of initiators was shown to significantly affect the molecular weight control and molecular weight distribution of PEtOx oligomers. Methyl triflate initiated polymerizations were found to result in oligomers with low polydispersity (PDI) values around 1.10-1.15 and symmetrical chromatograms were obtained via size exclusion chromatography (SEC) studies with the use of refractive index, light scattering and viscosity detectors. However, EtOx polymerizations initiated by halide containing initiators such as benzyl chloride, dibromo- and diiodo-p-xylene, and vinylsilylpropyl iodides yielded PEtOx oligomers with higher PDI values ~ 1.30-1.40. Higher molecular weight distributions can be attributed to the presence of covalent species during polymerization and slower initiation rate as evidenced by kinetic studies when compared to PEtOx prepared from methyl triflate initiators. In all cases, termination reactions with aliphatic cyclic amines were quantitative. Mono- and diamine functional PEtOx oligomers with controlled molecular weight and excellent end-group functionality may be used as prepolymers for incorporation into multiblock and graft copolymer and crosslinked structures for a variety of applications such as membranes and hydrogels for tissue engineering matrices.
Poly(2-ethyl-2-oxazoline) containing block copolymers were prepared using the macroinitiator method. First, amphiphilic triblock copolymers with hydrophobic poly(arylene ether sulfone) (PSF) central block and hydrophilic PEtOx side blocks were synthesized via polymerization of EtOx sequences from tosylate functional telechelic PSF macroinitiators. PSFs are well-known engineering thermoplastics with excellent resistance to hydrolysis and oxidation, as well as displaying good mechanical properties, thermal stability and toughness. Phenol functional PSFs were prepared via step-growth polymerization of dichlorodiphenylsulfone and bisphenol-A (slight excess) monomers. Phenolic chain ends were then converted to aliphatic hydroxyethyl endgroups by reaction with ethylene carbonate. Upon treatment with p-toluenesulfonyl chloride, tosylate functional PSF macroinitiators were prepared. PEtOx-b-PSF-b-PEtOx triblock copolymers (pendent acyl groups of PEtOx side blocks) were partially hydrolyzed in an acidic medium to introduce random charged poly(ethylene imine) units to prepare ionomer structures that may show good salt rejection, water flux and antibacterial properties for membrane-based water purification applications.
Phosphonic acid modified poly(ethylene oxide)-b-poly(2-ethyl-2-oxazoline) (PEO-b-PEtOx) diblock copolymers were prepared via cationic ring opening polymerization of EtOx monomers from tosylate functional PEO macroinitiators and subsequent functionalization reactions on the polyoxazoline block. Post-modification reactions included controlled partial pendent acyl group hydrolysis under an acidic medium to form the random block copolymers of PEtOx and poly(ethyleneimine) (PEI), Michael addition of diethylvinyl phosphonate groups to PEI units and hydrolysis of the ethyl groups on the phosphonates to yield pendent phosphonic acid groups on the polyoxazoline block. After each step of functionalization reactions, structures and compositions were confirmed utilizing 1H NMR and the degree of phosphorylation was found to be > 95%. Both PEO and PEtOx are biocompatible polymers and the anionic quality of the phosphonic acid has the potential to be pH controllable and provide an environment where cationic drugs and contrast agents can be attached. Thus, these polymers have potential as drug carriers and contrast enhancement agents for magnetic resonance imaging applications. / Ph. D.
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Acidification assessment on blood plasma during purification of extracellular vesicles for downstream application of biomarker analysisLidell, Viktoria January 2024 (has links)
Extracellular vesicles (EV) originate from various cell types and reflect the contents of the originating cells. EVs are ubiquitous in nearly all body fluids, including blood plasma, and exhibit significant potential as biomarkers in disease diagnostics. However, isolating EVs from blood plasma remains challenging due to the lack of a standardised method. This study aimed to compare and optimize a density gradient ultracentrifugation workflow (DUC) against size exclusion chromatography-cation exchange chromatography (SEC-CEC) and evaluate SEC versus SEC-CEC. Common contaminants during isolation include lipoproteins (LP); previous studies have shown that lowering the pH of blood plasma can precipitate LP, enhancing isolation efficiency. Acidified blood plasma was compared with neutral plasma for EV isolation using all above mentioned methods. To assess the ability of the isolation methods to purify contaminants while retaining maximal EV yield, samples were analysed using multiple techniques, including particle quantity, free proteins, LP-associated apolipoprotein B, purity index (μg protein/particle), and EV-associated surface markers. The results indicate potential for DUC, but further optimization is necessary to improve the method and its isolation of EV. SEC-CEC emerged as an effective method, reducing contaminants by 71% (SEC) to 99% (SEC-CEC), increasing purity by 80%, and yielding positive signals from EV markers (SEC-CEC). The effect of acidification was ambiguous, it reduced apolipoprotein-B levels in plasma pre-isolation. However, post- isolation, neutral plasma exhibited significantly lower contaminations, albeit at the expense of total particle content and risking EV loss. The study underscored several advantages of SEC-CEC but indicated that acidification did not optimise isolation efficiency.
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Enhanced gel electrophoresis (GE) and inductively coupled plasma-mass spectrometry (ICP-MS) based methods for the identification and separation of proteins and peptidesHaider, Syed January 2012 (has links)
The main focus of the PhD study was to develop new gel electrophoresis and ICP-MS based methods to analyze a wide variety of the bio-molecules such as proteins, phosphoproteins and metalloproteins etc. The tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (tricine-SDS-PAGE) method is commonly used to resolve low molecular mass proteins, however, it requires a high percentage gel and a very complicated procedure to achieve this separation. This study describes a modification to tricine-SDS-PAGE to make it more effective for the separation of smaller proteins and for coupling to ICP-MS. The modified method employs low percentage PAGE gels and low reagent concentrations that provide efficient separations, good quantitation and low matrix levels that are compatible with ICP-MS. This modified method was applied to analyze phosphopeptides. Phosphopeptides are very small in size and difficult to separate using the other techniques such as Laemmli SDS-PAGE, original tricine-SDS-PAGE, immobilized metal affinity chromatography (IMAC), size exclusion chromatography (SEC) etc. In this study a simplified procedure is described based on modifying the original tricine-SDS-PAGE method. A comparative study showed that this modified method successfully resolved a digest mixture of very low to high molecular mass phosphopeptides/peptides. In off-line coupling of this method with ICP-MS, much better recoveries of the peptides from the gel were obtained as compared to traditional methods which indicate the compatibility of this modified method for quantitative studies. An on-line coupling of the modified system with ICP-MS was also demonstrated and it was applied for the separation, detection and quantification of phosphopeptides. Another application of this modified system was the separation of serum proteins. Blood serum contains five major protein groups i.e., albumin, alpha-1 globulin, alpha-2 globulin, beta globulin and gamma globulin. The separation of these five major proteins in a single gel is difficult to achieve using traditional methods. The modified system was shown to be superior for the separation of these serum proteins in a 7% (m/v) native-PAGE gel and a cellulose acetate membrane. A further study was carried out into controlling the factors that cause metal loss and protein fragmentation in SDS-PAGE. Using a reducing sample buffer, and heating to high temperatures (90-100ºC) in alkaline or acidic conditions may cause protein fragmentation and decrease the metal binding affinity. 70ºC was found suitable to prepare the sample at neutral, alkaline or acidic pH as no fragmentation observed. To prevent metal loss, the binding constant (log K) values of metal-amino acids, play the major role. Those metals which have high binding affinities with the amino acids in proteins can also be affected by the variation of the pH so prior information about pH to maintain the binding constant values is essential to minimize metal loss. This was observed in the loss of zinc, and to a lesser extent copper from human serum albumin (HSA) as measured by inductively coupled plasma mass spectrometry (ICP-MS). The method described above was applied for the separation and quantification of the serum proteins obtained from age-related macular degeneration (AMD) patients (where the AMD patients were from Moorfields Eye Hospital, London). Zn and Cu were quantified employing external calibration. Zn concentration showed variation whilst Cu did not show any significant variations in samples from AMD patients. A brief study of the interaction of cisplatin and oxaliplatin with HSA and transferrin was also performed. Cisplatin bound much faster than oxaliplatin with HSA. After 24 hours incubation, cisplatin showed a decrease in signal intensity which indicates that cisplatin binding decreases with time. Cisplatin binding with transferrin as compared to HSA was not significant, which could be the result of unstable Pt-transferrin complex formation. Oxaliplatin did not show high binding to either protein, perhaps due to the presence of the bulky, non polar DACH ligand.
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Caractérisation de polyacrylamide de hautes masses molaires par fractionnement couplage flux force couplée à la diffusion de la lumière / Caracterization of ultra high molar mass of polyacrylamides by Flow Field Flow Fractionation coupled to Multi Angle Light ScatteringSchmitt, Charlène Eva 16 December 2015 (has links)
: L’une des méthodes qui consiste à optimiser la production d’hydrocarbure est basée sur l’injection d’eau, viscosifiée par addition de polymères de type polyacrylamides, afin d’améliorer l’extraction de pétrole (RAH). Or, les propriétés viscosifiantes des polymères dépendent de leurs masses molaires. L’enjeu de ce travail de thèse a donc été de mettre en place de nouvelles méthodes pour la détermination de larges distributions en masses molaires et de grande dispersité, caractéristiques propres aux échantillons d’intérêt industriel dans le domaine pétrolier. La stratégie d’analyse retenue repose sur la chromatographie d’exclusion stérique (CES) et le fractionnement par couplage flux force (A4F) couplés à la diffusion de lumière et à la réfractométrie. Des polymères modèles ont été synthétisés par un procédé de polymérisation par transfert de chaîne réversible par addition fragmentation (RAFT/MADIX). Cela a permis d’obtenir des polymères dans une gamme de masses molaires comprises entre 103 et 107 g/mol et avec une dispersité inférieure à 1,4. Via l’utilisation de ces polymères, les performances et limites des deux méthodes séparatives investies ont été évaluées. Les conditions opératoires en A4F ont été déterminées et cette méthode s’est avérée être adaptée à l’analyse de polymères industriels distribués sur 3 décades de masses molaires. Au delà de l’analyse dimensionnelle, le couplage avec l’A4F a également permis une analyse conformationnelle. / One method for optimizing the production of hydrocarbon is based on the injection of water, viscosified by the addition of polymers such as polyacrylamides, in order to enhance the oil extraction (EOR). The viscosifying properties of polymers depend on their molecular masses. The aim of this thesis was therefore to develop new methods for determining wide molecular mass distributions and high dispersity, which are specific characteristics of samples of industrial interest in the oil sector. The analytical strategy used is based on size exclusion chromatography (SEC) and flow field flow fractionation (A4F), coupled to light scattering and refractometer. Model polymers were synthesized by a polymerization process by reversible addition fragmentation chain transfer (RAFT/MADIX). This allowed to obtain polymers in a range of molar masses between 103 and 107 g / mol and with a dispersity lower than 1.4. Through the use of these polymers, the capabilities and limitations of the two separation methods invested were evaluated. The A4F operating conditions were determined and this method has proved to be adapted to the analysis of industrial polymers distributed over 3 decades of molecular masses. Beyond the dimensional analysis, A4F-based coupling also allowed conformational analysis.
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Molecular Weight Limit Identified for the Synthesis of Externally Initiated Poly(3-hexylthiophenes) and Further Macrocyclic ConstructionsWong, Michael 19 March 2013 (has links)
Externally initiated o-tolyl initiated poly(3-hexylthiophene) (P3HT) was synthesized according to Grignard metathesis polymerization at varying chain length to compare number average molecular weights (Mn) obtained by gel permeation chromatography (GPC) and 1H NMR end group analysis. The extent of overestimation by GPC (1.3) was determined to be lower than previously reported for low Mn polymers. However, an apparent GPC quantification limit was observed as NMR Mn correlated well to predicted results. Static light scattering studies on high Mn polymers provided evidence that the true molecular weight was more similar to GPC-derived Mn. Despite nearly 100% external initiation efficiency, at a certain Mn limit new uninitiated chains may be synthesized. It is suggested that the synthesis of externally initiated P3HT should be limited to Mn below 40 kDa to ensure fully externally initiated chains. A proposal for the synthesis of externally initiated macrocyclic P3HT will also be discussed.
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Molecular Weight Limit Identified for the Synthesis of Externally Initiated Poly(3-hexylthiophenes) and Further Macrocyclic ConstructionsWong, Michael 19 March 2013 (has links)
Externally initiated o-tolyl initiated poly(3-hexylthiophene) (P3HT) was synthesized according to Grignard metathesis polymerization at varying chain length to compare number average molecular weights (Mn) obtained by gel permeation chromatography (GPC) and 1H NMR end group analysis. The extent of overestimation by GPC (1.3) was determined to be lower than previously reported for low Mn polymers. However, an apparent GPC quantification limit was observed as NMR Mn correlated well to predicted results. Static light scattering studies on high Mn polymers provided evidence that the true molecular weight was more similar to GPC-derived Mn. Despite nearly 100% external initiation efficiency, at a certain Mn limit new uninitiated chains may be synthesized. It is suggested that the synthesis of externally initiated P3HT should be limited to Mn below 40 kDa to ensure fully externally initiated chains. A proposal for the synthesis of externally initiated macrocyclic P3HT will also be discussed.
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DESENVOLVIMENTO E VALIDAÇÃO DE MÉTODOS CROMATOGRÁFICOS PARA AVALIAÇÃO DE INTERFERON-ALFA 2a EM FORMULAÇÕES FARMACÊUTICAS / DEVELOPMENT AND VALIDATION OF CHROMATOGRAPHIC METHODS FOR THE EVALUATION OF INTERFERON-ALFA 2a IN PHARMACEUTICAL FORMULATIONSSilva, Lucélia Magalhães da 17 March 2009 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The interferon is a cytokine with antiviral, antiproliferative, and immunomodulatory
properties. It is a protein synthesized by cells in response to viral infection, producing successive
biochemistry alterations. The chromatographic methods for evaluation of recombinant interferon-alfa
2a (rhIFN-α2a) in pharmaceutical products were validated in the present work. The reversed-phase
liquid chromatography method (RP-LC) was developed and validated using a Jupiter C4 column (250
mm x 4.6 mm), maintained at ambient temperature (25°C). The mobile phase A consisted of 0.1%
trifluoroacetic acid (TFA) and mobile phase B consisted of 0.1% TFA in acetonitrile, run in gradient:
0.01 1 min, 38% of B; 1 5 min, 38 43% of B; 5.01 20 min, 43 45% of B; 20.01 30 min, 45
48% of B; 30.01 40 min linear back to 38% of B and 40 42 min, 38% of B. The flow rate used
was 1 mL/min with detection at 214 nm. The chromatographic separation was obtained within 42 min
and it was linear in the concentration range of 0.5 50 MIU/mL (r2=0.9999). The size exclusion
method was developed and validated using a BioSep-SEC-S 2000 (300 mm x 7.8 mm), maintained at
ambient temperature (25°C). The mobile phase consisted of 1mM potassium phosphate monobasic,
8mM sodium phosphate dibasic and 200mM sodium chloride buffer, pH 7.4, run at a gradient flow
rate: 0.01 20 min, 0.5 mL/min; 20 25 min, 0.5 1.7 mL/min; 25 35 min, 1.7 mL/min; 35 38
min, 1.7 0.5 mL/min; 38 40 min, 0.5 mL/min. The method was linear in the concentration range of
0.5 - 50 MIU/mL (r2=0.9996). The procedures were validated by the parameters of specificity,
linearity, precision, accuracy, robustness, limit of quantitation and limit of detection. The methods
were applied for the evaluation of the rhIFN-α2a in pharmaceutical products, contributing for the
establishment of alternatives which improve the quality control, assuring the safety and therapeutic
efficacy of the biological product. / O interferon é uma citocina que possui ação antiviral, imunomoduladora e antiproliferativa. É uma proteína sintetizada pelas células em resposta a infecção viral, gerando sucessivas alterações bioquímicas. No presente trabalho foram validados métodos cromatográficos para a avaliação de interferon-alfa 2a (rhIFN-α2a) em produtos farmacêuticos. O método por cromatografia líquida em fase reversa (CL-FR) foi desenvolvido e validado empregando coluna Júpiter C4 (250 mm x 4,6 mm),
mantida a temperatura ambiente (25°C). A fase móvel A foi composta de ácido trifluoracético 0,1% e a fase móvel B de ácido trifluoracético 0,1% em acetonitrila, eluídas no gradiente: 0,01 1 min, 38% de B; 1 5 min, 38 43% de B; 5,01 20 min, 43 45% de B; 20,01 30 min, 45 48% de B; 30,01
40 min, 48 38% de B, mantendo-se nesta proporção até 42 min. Utilizou-se vazão de 1 mL/min e
detecção no ultravioleta a 214 nm. A separação cromatográfica foi obtida no tempo de 42 min, sendo
linear na faixa de concentração de 0,5 - 50 MUI/mL (r2=0,9999). Paralelamente, desenvolveu-se e
validou-se método cromatográfico por exclusão molecular (CL-EM) empregando coluna BioSep-SECS
2000 (300 mm x 7,8 mm), mantida a temperatura ambiente (25°C). A fase móvel foi composta de
tampão fosfato de potássio monobásico 1mM, fosfato de sódio dibásico 8mM e cloreto de sódio
200mM, pH 7,4, eluída no gradiente de fluxo: 0,01 20 min, 0,5 mL/min; 20 25 min, 0,5 1,7
mL/min; 25 35 min, 1,7 mL/min; 35 38 min, 1,7 0,5 mL/min; 38 40 min, 0,5 mL/min. O
método foi linear na faixa de concentração de 0,5 - 50 MUI/mL (r2=0,9996). Ambos os procedimentos
foram validados com base nos parâmetros de especificidade, linearidade, precisão, exatidão, robustez,
limite de quantificação e detecção. Os métodos foram aplicados para avaliação de rhIFN-α2a em
produtos farmacêuticos, contribuindo para o estabelecimento de alternativas que aprimoram o controle
da qualidade, garantindo a segurança e eficácia terapêutica do produto biológico.
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Síntese e caracterização de géis para cromatografia de exclusão por tamanho via reticulação de Acetato de Celulose com 4,4' - Difenilmetano Diisocianato (MDI) / Synthesis and characterization of gels for size exclusion chromotography by crosslinking cellulose acetate with 4,4' -diphenylmethane diisocyanate (MDI)Rosa, Wesley de Oliveira 28 March 2016 (has links)
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Previous issue date: 2016-03-28 / Não recebi financiamento / The need to obtain biomaterials in order to reduce environmental impacts has been the focus of research groups in recent years, and cellulose, a dominant component at most forms of plants is a promising resource because of its abundance. In order to improve the ability processing, the chemical modification of cellulose has been widely studied. Among the most important reactions of cellulose are: etherification, esterification, acetylation and oxidation; being cellulose acetate, viscose, nitrocellulose and cellulose ethers, the main cellulose derivatives. The chemical modification with isocyanates presents some unique properties, such as absence of by-products and chemical stability of the urethane group. In this work we were synthesized gels obtained by modified cellulose acetate (CA) with a degree of substitution (DS) 2,5 by crosslinking, with 4,4' - Diphenylmethane diisocyanate (MDI) in stoichiometry of 1:1, in homogeneous by varying the humidity and the homogenization time. For characterization were used the following techniques and tests: vibrational infrared absorption spectroscopy (Fourier Transform Spectrometer - FTIR), size exclusion Chromatography (SEC), molecular absorption spectrophotometry UV-VIS, density determining of the gels by pycnometry, determination of the coefficient swelling, determination of cross-links by Flory-Rehner theory, thermogravimetry (TG) and scanning electron microscopy (SEM). Crosslink density results showed that the gel synthesized in the absence of moisture suffered greater crosslinking with an average number of repeat units between the crosslinking points of about 1000 times lower. The potential applications of these gels were tested, by using than as stationary phase in size exclusion chromatography, having been assessed its efficiency in the fractionation and separation of natural and synthetic polymers. Results showed the effectiveness of the gel as stationary phase on separation of polymers, opening up a range of opportunities, taking into consideration the simplicity of the process and lower costs attributed to it. / A necessidade de se obter biomateriais na tentativa de reduzir impactos ambientais tem sido o foco de grupos de pesquisa nos últimos anos e, a celulose, um componente dominante na maioria das formas de plantas, é um recurso promissor devido à sua abundância. A fim de melhorar a capacidade de processamento, a modificação química da celulose tem sido amplamente estudada. Dentre as reações mais importantes da celulose estão: eterificação, esterificação, acetilação e oxidação; sendo o acetato de celulose, viscose, nitrocelulose e éteres de celulose, os principais derivados da celulose. A modificação química com isocianatos apresenta algumas propriedades únicas, como ausência de produtos secundários e estabilidade química do grupo uretano. Nesse trabalho foram sintetizados géis obtidos por meio da modificação de Acetato de Celulose (AC) com grau de substituição (GS) 2,5 através da reticulação com 4,4' - Difenilmetano Diisocianato (MDI), na estequiometria 1:1, em meio homogêneo, variando a umidade e o tempo de homogenização. Para caracterização foram utilizadas as seguintes técnicas e ensaios: espectroscopia vibracional de absorção no infravermelho por Transformada de Fourier (FTIR), cromatografia de exclusão por tamanho (SEC), espectrofotometria de absorção molecular UV-VIS, determinação de densidade dos géis por picnometria, determinação do coeficiente de intumescimento, determinação de ligações cruzadas pela teoria de Flory-Rehner, termogravimetria (TG) e microscopia eletrônica de varredura (MEV). Resultados da densidade de ligações cruzadas mostraram que o gel sintetizado na ausência de umidade sofreu uma maior reticulação, com um número médio de unidades de repetição entre os pontos de reticulação cerca de 1000 vezes menor. As aplicações potenciais desses géis foram testadas como fase estacionária em cromatografia de exclusão por tamanho, tendo sido avaliada sua eficiência no fracionamento e separação de polímeros naturais e sintéticos. Resultados mostraram a eficácia do gel como fase estacionária na separação de polímeros, abrindo uma gama de oportunidades, levando-se em consideração a simplicidade do processo e os baixos custos a ele atribuídos.
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