Univ., Diss--Stuttgart, 2006. / Quellen- und Literaturverz. S. 476 - 536.

Stuttgart, Univ., Diss., 2006

Magisterarbeit--Universität München.

Zugl.: München, Univ., Magisterarbeit, 2005/2006

Universiẗat, Diss., 2004--Leipzig.

Tierärztliche Hochsch., Diss., 2005--Hannover.

Heidelberg, Pädagogische Hochschule, Diss., 1992.

Nanopartículas de prata (AgNPs) vêm ganhando grande importância na prevenção contra infecções, principalmente pela sua incorporação em dispositivos médicos, tecidos entre outros produtos relacionados. Estudos prévios indicaram que partículas de menores tamanhos têm ação biocida mais efetiva. Nesse contexto, a separação granulométrica pode ser explorada para se obter partículas com as dimensões desejadas. A centrifugação foi escolhida, entre outros métodos de separação granulométrica, por sua possibilidade de ressuspensão das AgNPs após a separação, pela facilidade do aumento de escala e baixa complexidade. Um modelo do perfil de concentração (em uma cela centrífuga) de AgNPs em função do tempo e intensidade de centrifugação foi proposto a partir da Equação de Lamm, considerando a difusividade Browniana e o coeficiente de Svedberg calculado a partir do balanço de forças. A equação foi resolvida com a solução semi-analítica proposta inicialmente por Fujita (1962) e melhorada pelos alemães Joachim Behlke e Otto Ristau (2001). O desempenho da centrifugação de AgNPs sintetizadas pelo Método Turkevich foi avaliado analisando-se as partículas sobrenadantes por DLS, UV-Vis e microscopia eletrônica e comparando com o modelo proposto. O modelo previu razoavelmente a concentração total de partículas e a sua distribuição de tamanhos em diferentes tempos de centrifugação para forças de campo baixas (força centrífuga relativa até 1480). Para maiores forças de campo, houve uma sedimentação mais acelerada que a prevista pelo modelo. / Silver nanoparticles (AgNPs) have gained great importance in preventing infections, especially by their incorporation into medical devices, tissues and related products. Previous studies indicated that particles of smaller sizes have more effective biocidal action. In this context, granulometric separation may be explored to deliver nanoparticles of desired size. Centrifugation was chosen, among other particle size separation methods, for their ability to resuspend the AgNPs after separation, for the ease of scale-up and low complexity. A profile concentration model (in the centrifuge cell) of AgNPs as a function of time and intensity of centrifugation has been proposed from the Lamm equation, considering the Svedberg and Brownian diffusivity coefficients calculated from a force balance. The equation was solved with the semi-analytical solution proposed initially by Fujita (1962) and improved by the Germans Joachim Behlke and Otto Ristau (2001). The centrifugation performance of AgNPs synthesized by the Turkevich method was evaluated by analyzing the supernatant particles by DLS, UV-Vis and electron microscopy and comparing to the proposed model. The model reasonably predicted the total concentration of particles and their size distribution at different centrifugation times at low field strengths (1480 RCF). For higher field strengths, the sedimentation was faster than expected by the model.

Nanopartículas de prata (AgNPs) vêm ganhando grande importância na prevenção contra infecções, principalmente pela sua incorporação em dispositivos médicos, tecidos entre outros produtos relacionados. Estudos prévios indicaram que partículas de menores tamanhos têm ação biocida mais efetiva. Nesse contexto, a separação granulométrica pode ser explorada para se obter partículas com as dimensões desejadas. A centrifugação foi escolhida, entre outros métodos de separação granulométrica, por sua possibilidade de ressuspensão das AgNPs após a separação, pela facilidade do aumento de escala e baixa complexidade. Um modelo do perfil de concentração (em uma cela centrífuga) de AgNPs em função do tempo e intensidade de centrifugação foi proposto a partir da Equação de Lamm, considerando a difusividade Browniana e o coeficiente de Svedberg calculado a partir do balanço de forças. A equação foi resolvida com a solução semi-analítica proposta inicialmente por Fujita (1962) e melhorada pelos alemães Joachim Behlke e Otto Ristau (2001). O desempenho da centrifugação de AgNPs sintetizadas pelo Método Turkevich foi avaliado analisando-se as partículas sobrenadantes por DLS, UV-Vis e microscopia eletrônica e comparando com o modelo proposto. O modelo previu razoavelmente a concentração total de partículas e a sua distribuição de tamanhos em diferentes tempos de centrifugação para forças de campo baixas (força centrífuga relativa até 1480). Para maiores forças de campo, houve uma sedimentação mais acelerada que a prevista pelo modelo. / Silver nanoparticles (AgNPs) have gained great importance in preventing infections, especially by their incorporation into medical devices, tissues and related products. Previous studies indicated that particles of smaller sizes have more effective biocidal action. In this context, granulometric separation may be explored to deliver nanoparticles of desired size. Centrifugation was chosen, among other particle size separation methods, for their ability to resuspend the AgNPs after separation, for the ease of scale-up and low complexity. A profile concentration model (in the centrifuge cell) of AgNPs as a function of time and intensity of centrifugation has been proposed from the Lamm equation, considering the Svedberg and Brownian diffusivity coefficients calculated from a force balance. The equation was solved with the semi-analytical solution proposed initially by Fujita (1962) and improved by the Germans Joachim Behlke and Otto Ristau (2001). The centrifugation performance of AgNPs synthesized by the Turkevich method was evaluated by analyzing the supernatant particles by DLS, UV-Vis and electron microscopy and comparing to the proposed model. The model reasonably predicted the total concentration of particles and their size distribution at different centrifugation times at low field strengths (1480 RCF). For higher field strengths, the sedimentation was faster than expected by the model.

Stoffwechsel und antioxidativer Status bei Merinofleischschafen im peripartalen Zeitraum Medizinische Tierklinik, Veterinärmedizinische Fakultät, Universität Leipzig Eingereicht im Juni 2010 (99 Seiten, 28 Abbildungen, 38 Tabellen, 357 Literaturangaben) Problem- und Zielstellung: Dem antioxidativen System wird im Rahmen von Stoffwech-seluntersuchungen bei Schafen nur wenig Bedeutung geschenkt, jedoch gewinnt es als Schutz- und Regulationssystem zunehmend an Bedeutung. Besonders die Trächtigkeit und die Frühlaktation bei Mutterschafen sowie die postnatale Entwicklung der Lämmer stellen enorme Anforderungen an die Energieversorgung und an das antioxidative System. Das Ziel dieser Arbeit ist, die Bewältigung dieser Anforderungen darzustellen und zu zei-gen, ob und wie stark Zwillingsträchtigkeiten ein Belastung für Mutterschafe darstellen, und ob Lämmer aus einer Zwillingsträchtigkeit möglicherweise benachteiligt sind. Tiere, Material und Methoden: Untersucht wurden insgesamt 23 trächtige Merinofleisch-schafe und zwölf Merinofleischschaflämmer. Bei 13 Muttertieren wurde sonografisch eine Einlingsträchtigkeit (M1) und bei zehn eine Zwillingsträchtigkeit (M2) festgestellt. Bei den Lämmern stammten sechs Tiere aus einer Einlingsgeburt (L1) und sechs aus Zwillingsge-burten (L2). Den Muttertieren wurden von der 5. Woche a.p. bis 1 Woche a.p. wöchentlich sowie 2 Wochen p.p., den Lämmern eine, vier und zwölf Wochen post natum Blutproben entnommen. Im Serum wurden die Konzentrationen von Betahydroxybutyrat (BHB), Glu-cose, Bilirubin, freien Fettsäuren (FFS), Gesamtprotein und Albumin, die Aktivitäten der Glutamatdehydrogenase (GLDH), sowie im Vollblut die Aktivitäten der Superoxiddismutase (SOD) und der Glutathionperoxidase (GPX) gemessen. Ergebnisse: Die SOD- und GPX-Aktivitäten stiegen gleichermaßen bei einlingsträchtigen und zwillingsträchtigen Muttertieren signifikant an. Die SOD-Aktivitäten stiegen bei M1 von 488,2 ± 28 vier Wochen a.p. auf 524,8 ± 96,1 U/g Hb eine Woche a.p. und bei M2 von 447,4 ± 65,1 fünf Wochen a.p. auf 619,4 ± 141,1 U/g Hb zwei Wochen p.p. an. Die GPX-Aktivitäten bei M1 stiegen von 782,1 ± 220,5 eine Woche a.p. auf 1037,62 ± 382,9 U/ml Hk zwei Wochen p.p.. M2 zeigten eine tendenziell niedrigere Aktivität, welche von 641,8 ± 118,4 auf 911,8 ± 168,5 U/ml Hk anstieg. Es bestanden signifikante Zusammenhänge der SOD mit FFS, BHB und Gesamtprotein sowie der GPX mit Bilirubin, FFS und GLDH. Für die SOD-Aktivität wurde ein Referenzbereich von 328,10 bis 837,25 U/g Hb und für die GPX-Aktivität von 473,38 bis 1259,05 U/ml Hk bei Muttertieren ermittelt. Ausgenommen die Glucosekonzentration eine Woche a.p. bestanden keine signifikanten Differenzen zwi-schen M1 und M2. Die BHB-Konzentrationen zeigten bis zur Lammung einen konstanten Verlauf und stiegen bei M1 eine Woche a.p. auf 0,59 ± 0,27 mmol/l sowie bei M1 und M2 zwei Wochen p.p. auf 0,76 ± 0,29 mmol/l (M1) bzw. 0,77 ± 0,25 mmol/l (M2) signifikant an. Gesicherte Korrelationen bestanden zu FFS, Gesamtprotein und Glucose. Die Gesamtprotein- und Albuminkonzentrationen verliefen über den gesamten Untersuchungszeitraum nahezu konstant. Die Albuminkonzentration sank bei M1 nach einem kontinuierlichen An-stieg von einer Woche a.p. (37,2 ± 2,9 g/l) zu zwei Wochen p.p. (35,3 ± 3,6 g/l) signifikant ab. Gesicherte Korrelationen bestanden zu Glucose, SOD, BHB, Bilirubin und FFS. Die Glucose- Konzentrationen stiegen bei M1 bis eine Woche a.p. auf 4,84 ± 1,17 mmol/l sig-nifikant an, korrelierten neben den Proteinen mit Bilirubin und fallen 2 Wochen p.p. wieder auf ihren Ausgangswert ab, der bei M2 konstant blieb. Die Bilirubinkonzentrationen verlie-fen konstant, die der FFS fielen nach einem Anstieg eine Woche a.p. (M1) signifikant ab. Die GLDH-Aktivitäten zeigten a.p. einen konstanten Verlauf und p.p. einen signifikanten Anstieg auf 20,61 ± 14,11 U/l bei M2. Zwischen L1 und L2 bestanden zu keinem Zeitpunkt signifikante Unterschiede. Die SOD zeigte abnehmende Aktivitäten mit zunehmendem Lebensalter, - bei L1 von 757,7 ± 94,4 eine Woche p.p. auf 597,8 ± 255,0 U/g Hb 4 Wochen p.p. und bei L2 von 487,17 ± 353,3 auf 464,0 ± 330,9 U/g Hb. Sie korrelierte gesichert mit Albumin und Glucose in der ersten Lebenswoche. Die GPX-Aktivitäten stiegen mit zunehmendem Lebensalter bei statistisch gesicherter Korrelation mit Glucose von 724,3 ± 199,8 auf 1011,5 ± 132,9 U/ml Hk bei L1 und von 693,3 ± 120,8 auf 1052,0 ± 146,9 U/ml Hk bei L2. Für Lämmer wurden als Refe-renzwerte 43,00 bis 932 U/g Hb für die SOD bzw. 406,00 bis 1321,00 U/ml Hk für die GPX berechnet. Die Albumin- und BHB-Konzentrationen stiegen zur vierten bzw. zwölften Le-benswoche an, die Glucose-, Bilirubin- und FFS-Konzentrationen im Serum sanken zur 12. Lebenswoche ab. Die Gesamtproteinkonzentration und die Aktivität der GLDH verlie-fen konstant. Es bestanden signifikante Korrelationen zwischen BHB und Gesamtprotein, FFS, GLDH sowie zwischen Gesamtprotein und Glucose, Albumin sowie FFS. Des Weite-ren bestanden gesicherte Korrelationen zwischen Bilirubin und FFS sowie FFS und GLDH. Fazit: Die Aktivitäten der antioxidativen Enzyme SOD und GPX sowie die Konzentrationen der klinisch-chemischen Parameter zeigen mit dem Anstieg der SOD-Aktivität von 447 auf 619 U/g Hb bei M2 einerseits die peripartalen Belastungen und andererseits mit dem An-stieg der GPX-Aktivität von 782 auf 1038 U/g Hk bei M1 die Kompensations- und Regel-mechanismen bei dieser Belastungssituation auf. Die Untersuchungen entsprechen dem Zustand einer ausgeglichen Energiebilanz und gesundheitlich stabilen Bedingungen. Ein Einfluss der Lämmerzahl auf das antioxidative System bzw. den Stoffwechsel kann weder bei Mutterschafen noch bei Lämmern statistisch signifikant belegt werden. / Metabolism and antioxidative status of merino sheep for meat production in the peripartum time period Large Animal Clinic for Internal Medicine, Faculty of Veterinary Medicine, University of Leipzig Submitted in June 2010 (100 pages, 28 figures, 38 tables, 357 references) Definition of the problem and objective: Until now, the research regarding the metabol-ism of sheep focussed very little on the importance of the antioxidative system, but the significance of its function as a protective and regulative system is increasing. Especially the pregnancy and the early lactation of the ewes as well as the postnatal development of the lambs places enormous demands upon the energy supply and the antioxidative sys-tem. The objective of this study is to show how these demands are met and to determine whether a twin-pregnancy represents an additional stress for the ewes, and whether lambs from a twin-pregnancy are possibly disadvantaged. Animals, materials and methods: 23 pregnant merino ewes and twelve merino lambs were analyzed. Sonographic tests showed that 13 ewes were pregnant with one lamb (M1), and ten showed a twin-pregnancy (M2). Six of the lambs were born as single lambs (L1), six as twins (L2). Blood samples were taken from the ewes every week from the fifth until the week before the birth, as well as two weeks after birth, the blood samples from the lambs were taken one, four and twelve weeks postpartum. The concentration in the serum of the following components was measured: betahydroxybutyrate (BHB), glucose, biliru-bine, free fatty acids (FFS), total protein and albumine, the activity of the glutamatedehy-drogenasis (GLDH), as well as the activity in whole- blood of superoxidedismutasis (SOD) and glutathionperoxidasis (GPX). Results: The SOD- and GPX-activities rose significantly at the same rate for mother sheep pregnant with one lamb or with twins. The SOD-activity rose for M1 from 488,2 +/- 28 four weeks prepartum to 524 +/- 96,1 U/g Hb one week prepartum, and for M2 from 447,4 +/- 65,1 five weeks prepartum to 619,4 +/- 141,1 U/g Hb two weeks prepartum. The GPX-activity for M1 rose from 782,1 +/- 220,5 one week prepartum to 1037,62 +/- 382,9 U/ml two weeks postpartum, while M2 showed a tendency towards lower activity, which rose from 641,8 +/- 118,4 to 911,8 +/- 168,5 U/ml Hk. There were significant correlations between the SOD and the FFS, the BHB and the total protein as well as the GPX with bili-rubine, FFS and GLDH. For the ewes, an SOD-activity reference range between 328,10 and 837,25 U/g Hb was determined, and a GPX-activity reference range between 473,38 and 1259,05 U/ml Hk. There were no significant differences between M1 and M2 except for the concentration of glucose. The BHB-concentration stayed constant up to birth and then rose significantly to 0,59 +/- 0,27 mmol/l for M1 one week postpartum and for both M1 and M2 to 0,76 +/- 0,29 mmol/l (M1) and 0,77 +/- 0,25 mmol/l (M2) two weeks postpartum. A reliable correlation could be determined with FFS, total protein and glucose. The total protein and the albu-mine concentration stayed almost constant during the whole analyzed time period. After a continuous increase between one week prepartum (37,2 +/- 2,9 g/l) and two weeks post-partum (35,3 +/- 3,6 g/l), the albumine concentration dropped considerably. Here, reliable correlations could be determined with glucose, SOD, BHB, bilirubine and FFS. For the group M1, the glucose concentrations rose significantly until one week prepartum to 4,84 +/- 1,17 mmol/l, correlated with both the proteins and bilirubine, then fell back to their initial level two weeks postpartum, while they did not change for M2. The concentrations of bili-rubine stayed constant, the FFS-concentrations fell significantly after an increase one week prepartum (M1). The GLDH-activities showed a constant trend prepartum, then rose significantly postpartum to 20,61 +/14,11 U/l for M2. There were no significant differences between L1 and L2 at any time. The SOD showed decreasing activity with increasing age, from 757,7 +/- 94,4 one week prepartum to 597,8 +/- 255,0 U/g Hb four weeks postpartum for L1 and from 487,17 +/- 353,3 to 464,0 +/- 330,9 U/g Hb for L2. A reliable correlation was determined with albumine and glucose in the first week after birth. The GPX-activities rose with increasing age with a statistically reliable correlation with glucose from 724,3 +/- 199,8 to 1011,5 +/- 132,9 U/ml Hk for L1 and from 693,3 +/- 120,0 to 1052,0 +/- 146,9 U/ml Hk for L2. The calculated reference val-ues for lambs were 43,00 to 932 U/g Hb for SOD and 406,00 to 1321,00 U/ml Hk for GPX. The concentrations of albumine and BHB rose towards the fourth and respectively the twelvth week of life, the levels of glucose, bilirubine and FFS dropped towards the 12th week. The total protein concentration and the GLDH-activities stayed constant. There were significant correlations between BHB and total protein, FFS, GLDH as well as between total protein and glucose, albumine and FFS. In addition, there were reliable correlations between bilirubine and FFS and FFS and GLDH. Conclusion: The activities of the antioxidative enzymes SOD and GPX as well as the concentrations of the clinical-chemical parameters show the prepartum stress on one side with the rise of the SOD-activity from 447 to 619 U/g for the group M2, and the compensa-tion and regulation mechanisms during this stress period on the other side with the in-crease of the GPX-activity from 782 to 1038 U/g Hk for the group M1. The results of the tests correspond to the status of a well-regulated energy balance and stable health condi-tions. An influence of the number of lambs on the antioxidative system or the metabolism for both lambs and ewes can not be shown with statistical significance.