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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Towards biomedical intelligent sensors

Yalcinkaya, Fikret January 1998 (has links)
Potassium, sodium, and calcium are crucial electrolytes of human blood. Among the functions of the electrolytes are maintenance of osmotic pressure and water distribution in the various body fluid compartments, maintenance of the proper pH, regulation of the proper function of the heart and other muscles, involvement in oxidation-reduction or electron transfer reactions, and participation in catalysis as cofactors for enzymes. Therefore, abnormal levels of electrolytes may be either the cause or the consequence of a variety of disorders, and thus the determination of electrolytes in different body fluids in general and in whole human blood particularly is one of the most important functions of the clinical laboratory . Serum or plasma is the usual specimen employed for assay of potassium, sodium, and calcium but not whole human blood. This research intended to create a sensor-array capable of analysing potassium, sodium, and calcium ion-activity in whole human blood based on miniaturised ion-sensors and zero-current direct potentiometry. This research dealt with sensing-side of the sensor-array hoping for integration of these sensors with microelectronics or discrete parts based electronics in due time. Clinics use single electrodes for K+, Na+, and Ca2+ sensing in body fluids. However, single sensing is costly and in emergency cases time consuming as well. Therefore a portable, battery-operated cost- and time-effective sensor array is needed for multi-sensing of r, Na +, and Ca2 + either in emergency cases in field or for patient near bed-side measurement/monitoring. The approach of this thesis to the problem is as follows: This thesis has five phases, all equally important. The first phase, a theoretical phase, mainly deals with the determination of the technique which fits best with chemical sensors and integration with microelectronics, and the decision among many alternative chemicals, whether natural or man-made, available for multi-sensing realisation, by taking into account all the best efforts devoted to development of chemical-sensors. The second phase is the miniaturisation process of the electrochemical sensor-array, either ion-sensors or reference electrode, as much as possible. The third phase is multi-sensing application of the sensorarray for sensing K+, Na+, and ci+ with binary and mixed electrolytes and with artificial and whole human blood respectively, the fourth phase is the sensor-array response with only millilitre or microlitre volumes of whole human blood and the fifth phase is the integration of a sensor array with discrete, parts based, electronic circuitry. So, as a new application a disposable reference electrode has been realised which reasonably fits with the sensor array for the analysis of potassium, sodium, and calcium in whole human blood. Since all the single sensing of these cations have been realised by using a conventional reference electrode, either silver/silver chloride or calomel electrode, which is a bulky and expensive alternative, this research prepared, tested, and implemented a new disposable reference electrode for the sensor-array based on a poly (vinyl alcohol) matrix incorporating a proper amount of Kel. Having a successfully working miniaturised reference electrode, valinomycin, ETH 157, and ETH 1001 ionophores have been used as the selective materials for potassium, sodium, and calcium in whole human blood, respectively. Multisensing applications have only used solutions as testing medium whereas the work described in this thesis goes one step further and uses artificial and whole human blood with fairly reasonable responses.
2

An evaluation of human erythrocyte sulphydryl groups

Sommerville, W. January 1987 (has links)
No description available.
3

The kinetics of glucose transport in human red blood cells

Walmsley, A. R. January 1986 (has links)
No description available.
4

Polychlorinated biphenyls and their metabolites in human blood : Method development, identification and quantification

Hofvander, Lotta January 2006 (has links)
<p>PCBs are well known environmental pollutants. They are also precursors to metabolites, as the hydroxy-PCBs and the methylsulfonyl-PCBs. This thesis presents a validated methodology for analysis of PCB metabolites and a structural identification of 38 hydroxy-PCBs in human blood. Further methodological development resulted in an identification of a similar number of methylsulfonyl-PCBs.</p><p>The analytical method has been applied in two extensive studies of humans, consisting of maternal and cord blood from Dutch women and of blood from humans living in Slovakia. The Dutch shows that the relative transfer of hydroxy-PCBs from the mother to the foetus is higher compared to the PCBs. Even though the chemical plant in Michalovce in Slovakia had been shut down for over 20 years, the concentrations of PCB and its metabolites were among the highest detected in European human blood.</p>
5

Polychlorinated biphenyls and their metabolites in human blood : Method development, identification and quantification

Hofvander, Lotta January 2006 (has links)
PCBs are well known environmental pollutants. They are also precursors to metabolites, as the hydroxy-PCBs and the methylsulfonyl-PCBs. This thesis presents a validated methodology for analysis of PCB metabolites and a structural identification of 38 hydroxy-PCBs in human blood. Further methodological development resulted in an identification of a similar number of methylsulfonyl-PCBs. The analytical method has been applied in two extensive studies of humans, consisting of maternal and cord blood from Dutch women and of blood from humans living in Slovakia. The Dutch shows that the relative transfer of hydroxy-PCBs from the mother to the foetus is higher compared to the PCBs. Even though the chemical plant in Michalovce in Slovakia had been shut down for over 20 years, the concentrations of PCB and its metabolites were among the highest detected in European human blood.
6

Níveis de substâncias tóxicas persistentes (PTS) em sangue de parturientes de sete áreas selecionadas do Estado de São Paulo - Brasil

Rudge, Cibele Vieira Cunha [UNESP] 18 February 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-18Bitstream added on 2014-06-13T20:44:30Z : No. of bitstreams: 1 rudge_cvc_dr_botfm.pdf: 9269274 bytes, checksum: cdbb47e57819d006be95833d9159126f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / University Of Tromso / Noruega / OBJETIVO: Determinar substâncias tóxicas persistentes (PTS) no sangue de 160 parturientes em áreas do Estado de São Paulo-Brasil. SUJEITOS E MÉTODOS: Foram analisados os PCBs (99, 101, 118, 138, 153, 156, 163, 170, 180, 183, 187, 194) e pesticidas organoclorados ( -HCH, -HCH, -HCH, HCB, p,p'-DDE, p,p'-DDT, t-chlordane, cchlordane, oxy-chlordane, t-nonachlor and c-nonachlor) em sete áreas; duas rurais (Botucatu e Ribeirão Preto), uma industrial (Campinas), uma litorânea (Santos) e três urbanas em São Paulo (UNIFESP, Vila Nova Cachoeirinha e Leonor Mendes de Barros). Valores abaixo do limite de detecção (LOD) foram substituídos por 0.5XLOD. Teste de Kruskall Wallis e Dumm compararam as áreas com níveis de PTS acima do LOD. O projeto foi aprovado pelo CEP da FMB. RESULTADOS: Os valores das PTS (ng/g lipideo) foram baixos. PCBs 118, 138, 153, p-p’-DDE e pesticidas -HCH, - CH, HCB, oxy-chlordane e t-nonachlor tiveram níveis acima do LOD em mais de 70% das amostras. PCB 118 foi significativamente diferente nas áreas, com concentração maior na industrial (Campinas; 4.64). O organoclorado p-p’-DDE na zona rural de Ribeirão Preto; (123.05) foi maior que na urbana de Vila Nova Cachoeirinha. A mediana do ß-HCH para as áreas foi 6.31, significativamente maior na zona rural de Botucatu (18.20). A maior concentração de oxy-chlordane (3.59) e de t-nanochlor (1.17) foi na zona rural de Ribeirão Preto (p<0.05), diferentes também da área urbana (Leonor Mendes de Barros; p<0.05). CONCLUSAO: As concentrações das PTS foram baixas com diferenças entre as áreas; os maiores valores estavam nas parturientes da zona rural. / Persistent organic pollutants (POPs) present in the living environment are thought to have detrimental health effects on the population, with pregnant women and the developing foetus being at highest risk. We report on the levels of selected POPs in maternal blood of 160 delivering women residing in different regions within the São Paulo State, Brazil. Overall levels of measured compounds were found to be low with only PCBs 118, 138, 153 congeners, p-p’-DDE metabolite, -HCH, -HCH, HCB, oxy-chlordane and t-nonachlor pesticides having levels above LOD in more than 70% of the samples, thus comparisons between sites were performed for those compounds only. Statistical differences between sites were only observed for PCB 118 congener, with the highest concentration measured in the industrial site – Campinas (4.7 ng/g lipids). The p,p’-DDE metabolite was detected in all participants, with the median for all sites being 58.2 ng/g lipids, and large regional differences were evident. The highest levels of p,p’-DDE were measured in the rural 2 site – Ribeirão Preto with a median of 123 ng/g lipids that was significantly higher if compared with the urban 2 site (São Paulo City). The median concentration of ß-HCH for all sites was 6.31 ng/g lipids with the significantly highest concentration found in the rural 1 site – Botucatu (18.20 ng/g lipids). Oxy-chlordane was detected in all samples, with the highest concentration measured in the rural 2 site - Ribeirão Preto (3.6 ng/g lipids)¸which was found to be significantly higher than in all other sites The t-nonachlor compound was detected in 99% of samples with the highest concentration being 1.17 ng/g lipids, also in the rural 2 site- Ribeirão Preto. The level found in the rural 2 site was significantly higher than the level measured in the urban 3 site (São Paulo City)... (Complete abstract click electronic access below)
7

Advancing mechanistic understanding of glycosyltransferases

Gagnon, Susannah Melanie Lynn 24 April 2019 (has links)
Glycosyltransferase enzymes synthesize glycosidic linkages, generating carbohydrates and carbohydrate-linked entities ranging from cellulose, starch, and chitin to glycolipids, glycopeptides, and natural product antibiotics. These syntheses involve stereo- and regio-specific sugar transfer from an activated donor molecule, often a UDP-sugar, to an acceptor molecule. Functionally, glycosyltransferases are classified as either “retaining” or “inverting” enzymes depending on whether the stereochemical linkage of the donor substrate is conserved in the product. While inverting glycosyltransfer is mechanistically straightforward, the retaining mechanism remains poorly understood. For retaining glycosyltransferases, the central question is whether transfer occurs via a front-face “SNi-like” mechanism or through a ‘double displacement’ mechanism that invokes a glycosyl-enzyme covalent intermediate. GTA and GTB are retaining enzymes that catalyze the final step in human ABO(H) blood group A and B antigen synthesis through UDP-GalNAc or UDP-Gal transfer, respectively, to the H-antigen disaccharide acceptor. Although they have been intensively characterized, the processes of substrate recognition, mobile loop organization, and product release in GTA and GTB has long resisted explanation. Further, the question of the retaining enzyme mechanism persists, though the covalent intermediate of the proposed double displacement mechanism has been detected via mass spectrometry experiments with GTA/GTB mutants. Building on previous investigations, we have aimed to characterize and have uncovered details of mechanism, substrate binding, loop organization, and product release using a combined kinetic and structural approach. These investigations are essential not only for understanding GTA, GTB, and retaining glycosyltransferases as a whole, but also for the rational design of inhibitors. Such inhibitors could selectively target, for example, bacterial glycosyltransferases and thus would represent a new class of antimicrobials. / Graduate
8

Níveis de substâncias tóxicas persistentes (PTS) em sangue de parturientes de sete áreas selecionadas do Estado de São Paulo - Brasil /

Rudge, Cibele Vieira Cunha. January 2010 (has links)
Orientador: Iracema M. P. Calderon / Orientador: Jon Oyvind Odland / Banca: Rosiane Mattar / Banca: Adriano Dias / Banca: Halina Barbara Rollin / Resumo: OBJETIVO: Determinar substâncias tóxicas persistentes (PTS) no sangue de 160 parturientes em áreas do Estado de São Paulo-Brasil. SUJEITOS E MÉTODOS: Foram analisados os PCBs (99, 101, 118, 138, 153, 156, 163, 170, 180, 183, 187, 194) e pesticidas organoclorados ( -HCH, -HCH, -HCH, HCB, p,p'-DDE, p,p'-DDT, t-chlordane, cchlordane, oxy-chlordane, t-nonachlor and c-nonachlor) em sete áreas; duas rurais (Botucatu e Ribeirão Preto), uma industrial (Campinas), uma litorânea (Santos) e três urbanas em São Paulo (UNIFESP, Vila Nova Cachoeirinha e Leonor Mendes de Barros). Valores abaixo do limite de detecção (LOD) foram substituídos por 0.5XLOD. Teste de Kruskall Wallis e Dumm compararam as áreas com níveis de PTS acima do LOD. O projeto foi aprovado pelo CEP da FMB. RESULTADOS: Os valores das PTS (ng/g lipideo) foram baixos. PCBs 118, 138, 153, p-p'-DDE e pesticidas -HCH, - CH, HCB, oxy-chlordane e t-nonachlor tiveram níveis acima do LOD em mais de 70% das amostras. PCB 118 foi significativamente diferente nas áreas, com concentração maior na industrial (Campinas; 4.64). O organoclorado p-p'-DDE na zona rural de Ribeirão Preto; (123.05) foi maior que na urbana de Vila Nova Cachoeirinha. A mediana do ß-HCH para as áreas foi 6.31, significativamente maior na zona rural de Botucatu (18.20). A maior concentração de oxy-chlordane (3.59) e de t-nanochlor (1.17) foi na zona rural de Ribeirão Preto (p<0.05), diferentes também da área urbana (Leonor Mendes de Barros; p<0.05). CONCLUSAO: As concentrações das PTS foram baixas com diferenças entre as áreas; os maiores valores estavam nas parturientes da zona rural. / Abstract: Persistent organic pollutants (POPs) present in the living environment are thought to have detrimental health effects on the population, with pregnant women and the developing foetus being at highest risk. We report on the levels of selected POPs in maternal blood of 160 delivering women residing in different regions within the São Paulo State, Brazil. Overall levels of measured compounds were found to be low with only PCBs 118, 138, 153 congeners, p-p'-DDE metabolite, -HCH, -HCH, HCB, oxy-chlordane and t-nonachlor pesticides having levels above LOD in more than 70% of the samples, thus comparisons between sites were performed for those compounds only. Statistical differences between sites were only observed for PCB 118 congener, with the highest concentration measured in the industrial site - Campinas (4.7 ng/g lipids). The p,p'-DDE metabolite was detected in all participants, with the median for all sites being 58.2 ng/g lipids, and large regional differences were evident. The highest levels of p,p'-DDE were measured in the rural 2 site - Ribeirão Preto with a median of 123 ng/g lipids that was significantly higher if compared with the urban 2 site (São Paulo City). The median concentration of ß-HCH for all sites was 6.31 ng/g lipids with the significantly highest concentration found in the rural 1 site - Botucatu (18.20 ng/g lipids). Oxy-chlordane was detected in all samples, with the highest concentration measured in the rural 2 site - Ribeirão Preto (3.6 ng/g lipids)¸which was found to be significantly higher than in all other sites The t-nonachlor compound was detected in 99% of samples with the highest concentration being 1.17 ng/g lipids, also in the rural 2 site- Ribeirão Preto. The level found in the rural 2 site was significantly higher than the level measured in the urban 3 site (São Paulo City)... (Complete abstract click electronic access below) / Doutor
9

Wettability and evaporation of sessile drops of biological fluids

Bou-Zeid, Wassim 04 November 2014 (has links)
Le processus d'étalement et d'évaporation d'une goutte de suspensions de particules sur une surface solide est très intéressant permettant la formation de motifs. Une étude expérimentale à été effectuée avec du sang total humain et avec des fluides purs dans une chambre sous atmosphère contrôlée en humidité relative. Pour des angles de contact faible, le processus d'étalement/évaporation peut être divisé en deux régimes. Un premier régime rapide gouverné par un équilibre entre les forces visqueuses et les forces capillaires et un deuxième régime plus lent dominé par la cinétique d'évaporation. Nous montrons que les bio-colloïdes jouent un rôle significatif sur la dynamique de la ligne de contact. La vitesse moyenne de la ligne de contact suit la même dynamique d'étalement que le modèle de Tanner, où le temps d'étalement et les paramètres géométriques de la goutte sont fonctions de l'humidité. Dans cette étude, nous montrons que l'humidité relative influence les paramètres géométriques de la goutte et par conséquent le motif a la fin du processus d'évaporation. Un modèle purement diffusif pur a été obtenu dont le diamètre de mouillage et l'angle de contact sont fonction de l'humidité. Pour l'analyse morphologique des motifs de craquelures, une méthode de segmentation manuelle a été utilisée comme une méthode de référence pour la validation de la méthode de segmentation automatique développée dans "iBlood". Par cette méthode, nous montrons que la cinétique d'évaporation influence la distribution structurelle et morphologique des cellules de forme trapézoïdale, et par conséquent, l'espacement des fractures moyenne finale. / Spreading/evaporation process of droplets over solid surfaces is a fundamental process and a wide research field because of number of applications in printing, micro-electronics, DNA analysis and even in biomedical. This experimental work aims to investigate the effect of relative humidity on the contact line dynamics, on the evaporation dynamics and on the final pattern of a drop of whole human blood. The spreading of a pure fluid model that has the same physical properties as human blood was studied and compared to the blood. We showed that bio-colloids play significant effect on the dynamics of contact line and the pinning effect of the drop. For low contact angles, we showed that the spreading/evaporation process could be divided into two regimes. A fast first regime determined by a balance between viscous forces and capillary forces and a second slower regime dominated by the evaporation rate. Physical mechanisms that are responsible for the spreading enhancement are proposed and discussed. The average velocity of the contact line was found to follow the same behaviour as Tanner's model, where the spreading dynamics and geometrical parameters of the droplet are function of relative humidity. The experimental measurements are in a good agreement with the purely diffusive model where the equilibrium wetting radius and contact angle are function of relative humidity. For the morphological analysis of crack patterns, a manual segmentation method was used as a reference for the validation of the automatic developed segmentation method. We showed that the evaporation rate influences structural distribution of plaques in the corona region and hence, the mean crack spacing.
10

EVALUATION OF PERFLUOROALKYL ACIDS (PFAAs) IN WATER ENVIRONMENT, FOOD, AND HUMAN BODY IN KLANG VALLEY, MALAYSIA / マレーシア、クラン渓谷における水環境、食品、人体中ペルフルオロアルキル酸(PFAAs)の評価

MOHD, REDZUAN BIN RAMLI 24 September 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22058号 / 工博第4639号 / 新制||工||1723(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 米田 稔, 教授 清水 芳久, 教授 高野 裕久 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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