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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.
61

Expressão e localização de receptores Toll-like -1, -2, -4 e -6 em membranas corioamnióticas de gestações complicadas por corioamnionite histológica /

Moço, Natália Prearo. January 2011 (has links)
Resumo: Não disponível / Abstract: Acute chorioamnionitis is a response to microbial infection of the amniotic fluid. The innate immune system constitutes the host's first line of defense against pathogens and, in this regard, Toll-like receptors (TLRs) are important regulators of such nonspecific response. However, the expression of these receptors in chorioamniotic membranes in pregnancies complicated by chorioamnionitis has not been well established. Objective:The purpose of this study was to examine the localization of TLR-1, TLR-2, TLR-4 and TLR-6 in fetal membranes and determine whether histologic chorioamnionitis is associated with changes in gene expression of these receptors. One hundred and fifteen chorioamniotic membranes were included in the study. They were collected at the Obstetrics Service of the Botucatu Medical School, São Paulo State University, UNESP, from pregnant women with preterm delivery or term delivery with or without labor. Both groups were stratified on the basis of the presence of histologic chorioamnionitis. Fragments of the chorioamniotic membranes were sent for histopathologic analysis in order to confirm histologic chorioamnionitis. Other membranes fragments measuring 1cm2 were placed into RNA later and submitted to total RNA extraction. After RNA extraction, the samples with concentration between 0.02 and 0.2 g/L of RNA were submitted to cDNA collection for later use in quantifying the expression of TLR-1, TLR-2, TLR-4 and TLR-6 by the real-time PCR technique using the TaqMan® Gene Expression Assays System. All membranes analyzed expressed TLR-1 and TLR-4, whereas 99.1% expressed TLR-2 and 77.4% expressed TLR-6. TLR-1 and TLR-2 expression were statistically higher in the membranes of preterm pregnancies in the presence of chorioamnionitis as compared with preterm membranes in the absence of the inflammatory infiltrate. Among the membranes of term pregnancies, there was... (Complete abstract click electronic access below) / Orientador: Márcia Guimarães da Silva / Coorientador: José Carlos Peraçoli / Banca: Angela Maria Victoriano de Campos Soares / Banca: Rosiane Mattar / Mestre
62

Mechanisms through which nuclear estrogen receptors remain transcriptionally active in the mouse hippocampus in absence of ovarian estrogens.

January 2017 (has links)
acase@tulane.edu / The goal of the following experiments was to determine the cellular mechanisms through which estrogen receptor activity is maintained in hippocampal cells following termination of ovarian function. Aim 1 determined that kinase signaling contributes to the maintenance of estrogen receptor activity in the hippocampus of ovariectomized mice in addition to local synthesis of brain derived “neuroestrogens”. Inhibition of both the mitogen activated protein kinase (MAPK) and phosphoinositide-3 kinase (PI3K) cascades with intracerebroventricular infusion of specific kinase inhibitors reduced estrogen response element (ERE)-dependent gene expression in the hippocampus of ovariectomized mice. Aim 2 determined that neuroestrogen synthesis, MAPK signaling, and PI3K signaling interact to regulate the transcriptional output of estrogen receptors in response to insulin like growth factor-1 receptor (IGF-1R) activation in the Neuro-2A cell culture model. Rapid IGF-1R-dependent MAPK signaling promotes, while PI3K signaling inhibits, IGF-1R-dependent activation of endogenous estrogen receptors in Neuro-2A cells. Long-term IGF-1R stimulation reduces ERE-dependent gene expression in part through phosphorylation of estrogen receptor alpha (ERα). Rapid IGF-1R-dependent activation but not long-term repression of estrogen receptor activity in Neuro-2A cells requires neuroestrogen synthesis. Aim 3 determined that exposure to 40 days of continuous unopposed estradiol at the time of ovariectomy results in lasting enhancement of estrogen receptor activity in the hippocampus and lasting enhancement of hippocampus dependent memory in female mice beyond the period of short-term estradiol exposure. Together these three aims determine that neuroestrogen synthesis and kinase signaling interact to actively maintain estrogen receptor signaling in neuronal cells and these autonomous neuronal mechanisms of estrogen receptor activation have functional consequences on cognition long after cessation of ovarian function. / 1 / Kevin J Pollard
63

Therapeutic systems for Insulin-like growth factor-1 / Therapeutische Systeme für Insulin-like growth factor-1

Schultz, Isabel January 2015 (has links) (PDF)
SUMMARY Insulin-like growth factor I (IGF-I) is a polypeptide with a molecular weight of 7.649 kDa and an anabolic potential. Thereby, IGF-I has a promising therapeutic value e.g. in muscle wasting diseases such as sarcopenia. IGF-I is mainly secreted by the liver in response to growth hormone (GH) stimulation and is rather ubiquitously found within all tissues. The effects of IGF-I are mediated by its respective IGF-I transmembrane tyrosine kinase receptor triggering the stimulation of protein synthesis, glucose uptake and the regulation of cell growth. The actions of IGF-I are modulated by six IGF binding proteins binding and transporting IGF-I in a binary or ternary complex to tissues and receptors and modulating the binding of IGF-I to its receptor. The nature of the formed complexes impacts IGF-I`s half-life, modulating the half-life between 10 minutes (free IGF-I) to 12 - 15 hours when presented in a ternary complex with IGF binding protein 3 and an acid labile subunit (ALS). Therefore, sustained drug delivery systems of free IGF-I are superficially seen as interesting for the development of controlled release profiles, as the rate of absorption is apparently and easily set slower by simple formulation as compared to the rapid rate of elimination. Thereby, one would conclude, the formulation scientist can rapidly develop systems for which the pharmacokinetics of IGF-I are dominated by the formulation release kinetics. However, the in vivo situation is more complex and as mentioned (vide supra), the half-life may easily be prolonged up to hours providing proper IGF-I complexation takes place upon systemic uptake. These and other aspects are reviewed in Chapter I, within which we introduce IGF-I as a promising therapeutic agent detailing its structure and involved receptors along with the resulting signaling pathways. We summarize the control of IGF-I pharmacokinetics in nature within the context of its complex system of 6 binding proteins to control half-life and tissue distribution. Furthermore, we describe IGF-I variants with modulated properties in vivo and originated from alternative splicing. These insights were translated into sophisticated IGF-I delivery systems for therapeutic use. Aside from safety aspects, the challenges and requirements of an effective IGF-I therapy are discussed. Localized and systemic IGF-I delivery strategies, different routes of administration as well as liquid and solid IGF-I formulations are reviewed. Effective targeting of IGF-I by protein decoration is outlined and consequently this chapter provides an interesting guidance for successful IGF-I-delivery. In Chapter II, we firstly outline the stability of IGF-I in liquid formulations with the intention to deliver the biologic through the lung and the impact of buffer type, sodium chloride concentration and pH value on IGF-I stability is presented. IGF-I integrity was preserved in histidine buffer over 4 months at room temperature, but methionine 59 oxidation (Met(o)) along with reducible dimer and trimer formation was observed in an acidic environment (pH 4.5) and using acetate buffer. Strong aggregation resulted in a complete loss of IGF-I bioactivity, whereas the potency was partly maintained in samples showing a slight aggregation and complete IGF-I oxidation. Atomization by air-jet or vibrating-mesh nebulizers yielded in limited Met(o) formation and no aggregation. The results of IGF-I nebulization experiments regarding aerosol output rate, mass median aerodynamic diameter and fine particle fraction were comparable with 0.9% sodium chloride reference, approving the applicability of liquid IGF-I formulations for pulmonary delivery. In Chapter III we escalated the development to solid delivery systems designed for alveolar landing upon inhalation and by deploying trehalose and the newly introduced for pulmonary application silk-fibroin as carriers. Microparticles were produced using nano spray drying following analyses including IGF-I integrity, IGF-I release profiles and aerodynamic properties. In vitro transport kinetics of IGF-I across pulmonary Calu-3 epithelia were suggesting similar permeability as compared to IGF-I’s cognate protein, insulin that has already been successfully administered pulmonary in clinical settings. These in vivo results were translated to an ex vivo human lung lobe model. This work showed the feasibility of pulmonary IGF-I delivery and the advantageous diversification of excipients for pulmonary formulations using silk-fibroin. Chapter IV focuses on an innovative strategy for safe and controllable IGF-I delivery. In that chapter we escalated the development to novel IGF-I analogues. The intention was to provide a versatile biologic into which galenical properties can be engineered through chemical synthesis, e.g. by site directed coupling of polymers to IGF-I. For this purpose we genetically engineered two IGF-I variants containing an unnatural amino acid at two positions, respectively, thereby integrating alkyne functions into the primary sequence of the protein. These allowed linking IGF-I with other molecules in a site specific manner, i.e. via a copper catalyzed azide-alkyne Huisgen cycloaddition (click reaction). In this chapter we mainly introduce the two IGF-I variants, detail the delivery concept and describe the optimization of the expression conditions of the IGF-I variants. In conclusion, we span from simple liquid formulations for aerolization through solid systems for tailored for maximal alveolar landing to novel engineered IGF-I analogues. Thereby, three strategies for advanced IGF-I delivery were addressed and opportunities and limitations of each were outlined. Evidence was provided that sufficiently stable and easy to manufacture formulations can be developed as typically required for first in man studies. Interestingly, solid systems – typically introduced in later stages of pharmaceutical development – were quite promising. By use of silk-fibroin as a new IGF-I carrier for pulmonary administration, a new application was established for this excipient. The demonstrated success using the ex vivo human lung lobe model provided substantial confidence that pulmonary IGF-I delivery is possible in man. Finally, this work describes the expression of two IGF-I variants containing two unnatural amino acids to implement an innovative strategy for IGF-I delivery. This genetic engineering approach was providing the fundament for novel IGF-I analogues. Ideally, the biologic is structurally modified by covalently linked moieties for the control of pharmacokinetics or for targeted delivery, e.g. into sarcopenic muscles. One future scenario is dicussed in the ‘conclusion and outlook’ section for which IGF-I is tagged to a protease sensitive linker peptide and this linker peptide in return is coupled to a polyethylenglykole (PEG) polymer (required to prolong the half-life). Some proteases may serve as proxy for sarcopenia such that protease upregulation in compromised muscle tissues drives cleavage of IGF-I from the PEG. Thereby, IGF-I is released at the seat of the disease while systemic side effects are minimized. / ZUSAMMEMFASSUNG Insulin-like growth factor I (IGF-I) ist ein 7.6 kDa großes Polypeptid, das eine anabole Wirkung besitzt und dadurch ein vielversprechendes Therapeutikum in Muskelerkrankungen wie z.B. Sarkopenie darstellt. IGF-I wird hauptsächlich von der Leber gebildet und infolge der Stimulation des Wachstumshormons Somatropin sezerniert. In fast jedem Gewebe des Körpers kommt IGF-I vor. Die Wirkungen von IGF-I werden über eigene Rezeptoren, die an die Zellmembran gebunden sind, die Rezeptor-Tyrosinkinasen, ausgeführt. Zu den Wirkungen gehören unter anderem die Stimulation der Proteinsynthese, die Aufnahme von Glucose in die Zellen und die Regulierung des Zellwachstums. Die Effekte von IGF-I werden von 6 IGF- Bindungsproteinen (IGFBP 1-6) gesteuert, indem IGF-I in einem binären oder ternären Komplex zu den Geweben transportiert oder auch die Bindung von IGF-I an den Rezeptor verhindert werden kann. Die sich bildenden Komplexe haben auch einen Einfluss auf die Halbwertszeit (HWZ) von IGF-I, da für ungebundenes IGF-I eine HWZ von ca. 10 Minuten festgestellt werden konnte, aber IGF-I, gebunden in einem ternären Komplex mit dem Bindungsprotein 3 und der säurelabilen Untereinheit (ALS) eine erhöhte HWZ von 12 – 15 Stunden aufweist. Deswegen sind „sustained drug delivery“ Systeme von ungebundenem IGF-I auf den ersten Blick interessant für die Entwicklung von kontrollierten Freisetungsprofilen, da die Absorptionsgeschwindigkeit offensichtlich und problemlos durch triviale Formulierung verlangsamt werden kann im Vergleich zu der schnellen Eliminationsgeschwindigkeit. Deshalb könnte man daraus schließen, dass ein Formulierungsexperte recht schnell Systeme entwickeln kann, in denen die Freisetzungskinetik der Formulierung über die pharmakokinetischen Eigenschaften von IGF-I dominiert. Jedoch ist die in vivo Situation wesentlich komplexer und wie oben bereits erwähnt, könnte die Halbwertszeit problemlos bis zu mehreren Stunden verlängert werden, sofern geeignete Komplexbildung von IGF-I nach systemischer Aufnahme erfolgt. Diese und weitere Aspekte werden in Kapitel I beschrieben. Außerdem stellen wir IGF-I als wertvolles Therapeutikum vor, beschreiben dessen Struktur, die beteiligten Rezeptoren und die daraus resultierenden Signalwege. Wir fassen die Kontrolle der Pharmakokinetik von IGF-I in der Natur zusammen, im Rahmen von einem komplexen System aus 6 Bindungsproteinen, die die Halbwertszeit und die Gewebeverteilung steuern. Außerdem beschreiben wir IGF-I Varianten, die veränderte Eigenschaften in vivo aufweisen und durch alternatives Spleißen entstanden sind. Diese Erkenntnisse werden in hochentwickelte „IGF-I delivery“ Systeme für den therapeutischen Gebrauch umgesetzt. Neben Sicherheitsaspekten werden die Herausforderungen und Anforderungen einer effektiven IGF-I Therapie diskutiert. Darüber hinaus wird über lokale und systemische „IGF-I delivery“ Strategien, verschiedene Verabreichungswege sowie flüssige und feste IGF-I Formulierungen berichtet. Ebenso wird die wirkungsvolle IGF-I Freisetzung am Zielort durch Ausschmückung des Proteins beschrieben und dementsprechend liefert dieses Kapitel eine interessante Orientierungshilfe für eine erfolgreiche IGF-I Therapie. Im Kapitel II untersuchen wir die Stabilität von IGF-I in flüssigen Formulierungen zur pulmonalen Anwendung bezüglich Puffersystem, Natriumchlorid Konzentration und pH Wert. Die IGF-I Integrität wurde im Histidin Puffer über 4 Monate bei Raumtemperatur aufrechterhalten. Allerdings wurde bei Verwendung eines Acetat Puffers pH 4.5, Oxidation am Methionin 59 (Met(o)) sowie die Entstehung von reduzierbaren Dimeren und Trimeren beobachtet. Starke Aggregation führte zum vollständigen Verlust der IGF-I Bioaktivität, während die Wirkung in Proben aufrechterhalten werden konnte, in denen eine geringe Aggregation, aber deutliche Oxidation festgestellt wurde. Nach der Verneblung der flüssigen IGF-I Formulierung im Histidin-Puffer pH 6.5 mit einem Druckluftvernebler und einem Schwingmembranvernebler wurde jeweils eine leichte Bildung von Met(o), aber keine Aggregatbildung ermittelt. Die Ergebnisse der IGF-I Verneblungsexperimente waren vergleichbar mit den Referenzwerten einer isotonischen Kochsalzlösung bezüglich der Abgabeleistung, dem massenbezogenen medianen aerodynamischen Durchmesser und dem Feinpartikel Anteil. Hierdurch wurde gezeigt, dass sich flüssige IGF-I Formulierungen zur pulmonalen Anwendung eignen. Im Kapitel III berichten wir von einer Weiterentwicklung zu festen IGF-I Formulierungen für die pulmonale Route unter Verwendung von Trehalose und Seidenfibroin als neues Trägermaterial für die pulmonale Applikation. Mikropartikel wurden durch Nanosprühtrocknung hergestellt und anschließend auf IGF-I Integrität, IGF-I Freisetzung und dem aerodynamischen Durchmesser untersucht. Die Kinetik des in vitro Transportes von IGF-I durch Calu-3 Lungenepithelzellen war vergleichbar zur Durchgängigkeit von Insulin, das bereits erfolgreich pulmonal verabreicht wurde. Dieser Erfolg wurden auch ex vivo in einem menschlichen Lungenlappen Model bestätigt. In der Arbeit wird somit gezeigt, dass IGF-I zur pulmonalen Anwendung geeignet ist und die Verwendung von Seidenfibroin eine nützliche Erweiterung zu den bisher eingesetzten Trägermaterialien darstellt. Das Kapitel IV konzentriert sich auf eine innovative Strategie, um IGF-I sicher und kontrollierbar zu verabreichen. In diesem Kapitel erweitern wir die Entwicklung zu neuartigen IGF-I Varianten. Wir streben damit an ein vielseitiges Biologikum zu entwickeln, dessen Eigenschaften durch chemische Reaktionen verändert werden können wie zum Beispiel die spezifische Verknüpfung mit Polymeren. Zu diesem Zweck erzeugten wir gentechnisch zwei IGF-I Varianten, die jeweils an zwei Positionen eine unnatürliche Aminosäure aufweisen und führten dadurch Alkine Gruppen in die Primärstruktur der Proteine ein. Diese Vorgehensweise ermöglicht es nun IGF-I mit anderen Molekülen positionsspezifisch zu verbinden wie zum Beispiel durch die kupferkatalysierte Azid-Alkin-Cycloaddition (Click – Reaktion). In diesem Kapitel stellen wir hauptsächlich die zwei IGF-I Varianten vor, beschreiben ausführlich das Konzept der IGF-I Zustellung und erklären die Vorgehensweise zur Optimierung der Expressionsbedingungen der IGF-I Varianten. Abschließend lässt sich sagen, dass sich diese Arbeit über einfach flüssige Formulierungen zur Verneblung, feste Formulierung mit guten aerodynamischen Eigenschaften zur Erreichung der Alveolen und neuartig entwickelte IGF-I Varianten erstreckt. Hierzu werden drei Strategien zur modernen IGF-I Gabe thematisiert und sowohl die Möglichkeiten als auch die Grenzen der jeweiligen Therapie erörtert. Wir haben den Nachweis erbracht, dass ausreichend stabile und leicht herzustellende Formulierungen entwickelt werden können, die üblicherweise für „First-In-Man“ Studien benötigt werden. Interessanterweise stellten sich die festen Formulierungen, die eigentlich in den späteren Phasen der pharmazeutischen Entwicklung eingeführt werden, als sehr vielversprechend heraus. Durch den Einsatz von Seidenfibroin als neuen Träger zur pulmonalen Anwendung haben wir einen neuen Verwendungszweck für Seidenfibroin etabliert. Der erfolgreiche Versuch ex vivo am menschlichen Lungenlappen Model liefert die feste Überzeugung, dass es möglich ist, IGF-I im Menschen pulmonal anzuwenden. Letztendlich, beschreibt die Arbeit die Expression von zwei IGF-I Varianten, die zwei unnatürliche Aminosäuren aufweisen, um eine neuartige Strategie zur IGF-I Verabreichung umzusetzen. Dieser gentechnische Ansatz liefert die Grundlage für neue IGF-I Varianten. Idealerweise, wird das Biopharmazeutikum strukturell durch kovalent gebundene Reste verändert, um die pharmakokinetischen Eigenschaften zu steuern oder um zielgenaue Wirkstoffabgabe zu erreichen zum Beispiel in den sarkopenischen Muskeln. Ein Zukunftsszenarium wird im Abschnitt „Conclusion and Outlook“ diskutiert, in dem IGF-I mit einem Protease empfindlichen Linker versehen wird, der wiederum mit einem Polyethylenglykol (PEG) Polymer verknüpft ist. Der PEG Rest wird benötigt, um die Hablbwertszeit von IGF-I zu erhöhen. Einige Proteasen könnten als Stellvertreter für Sarkopenie dienen, so dass die Hochregulierung der Proteasen in gefährdeten Muskelgeweben zur Spaltung von IGF-I und dem PEG Rest führt. Dadurch wird IGF-I am Ursprung der Erkrankungen freigesetzt, während die systemischen Nebenwirkungen weitgehend vermindert sind.
64

Characterization of bovine insulin like growth factor binding protein-2 : structure and function

Carrick, Francine Ellen. January 2001 (has links) (PDF)
Includes bibliographical references (leaves 291-311)
65

Characterization of bovine insulin like growth factor binding protein-2 : structure and function / by Francine Ellen Carrick. / Characterization of bovine insulin like growth factor binding protein two

Carrick, Francine Ellen January 2001 (has links)
Includes bibliographical references (leaves 291-311) / xxiii, 313 leaves : ill. (chiefy col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Molecular Biosciences, 2002
66

Regulation und Signaltransduktion der Toll-like-Rezeptoren in humanen Plazentazellen /

Klaffenbach, Daniela. Unknown Date (has links)
Erlangen, Nürnberg, Universiẗat, Diss., 2007. / Enth. 1 Sonderabdr. aus: American journal of reproductive immunology ; Vol. 53. 2005. - Beitr. teilw. dt., teilw. engl.
67

Studies of complexes formed in blood in vivo between an insulin-like growth factor analog and binding proteins

Gajanandana, Oraprapai. January 1997 (has links) (PDF)
Includes bibliographical references (43 leaves) This study shows that when LR3IGF-I is administered to animals in pharmacologically active doses, it may be present in either the free form or bound to IGF-binding protein(s) in the circulation. Age and nutrition which are factors that regulate synthesis of endogenous IGF-I and IGF-binding proteins, affect the in vivo formation of complexes between the analog and IGFBP(s). This study also suggests that IGFBP-1 inhibits the pharmacological activity of circulating LR3IGF-I on thymus whereas it appears to stimulate the pharmacological activity of LR3IGF-I in kidneys.
68

Microdisk fabrication by emulsion evaporation

Wong, Susanna Wing Man 17 September 2007 (has links)
Colloidal suspensions of disk-like particles have been of interest in both colloidal and liquid crystal studies because they exhibit unique liquid crystalline phases different from those of rod-like molecules. Disk-like particles, such as asphaltenes in heavy oil industry, clay particles in agriculture, and red blood cells in biology, are of great interest in a variety of industries and scientific areas. However, to fabricate monodisperse microdisks, uniform in structure or composition with precise control of particle size and shape has not yet succeeded. In this thesis, we show an experimental strategy of using microfluidic technique to fabricate homogeneous α-eicosene microemulsions with chloroform in an aqueous solution of sodium dedecyl sulfate (SDS). The monodisperse chloroform emulsions, generated by the glass-based microfluidic devices, ensure the precise control on microdisk particle size and shape. A systematic investigation was performed to study the relation between the resulted microdisk size and the initial concentration of α-eicosene in chloroform before evaporation. The smectic liquid crystalline phase inside the wax particles controls the coin-like disk shape below the melting temperature of wax’s rotator phase. The kinetics of the disk formation is observed using a polarized light microscope. Dynamic light scattering is used to characterize the Brownian motion of the microdisks, and the rotational diffusion is estimated from the image sequences taken by the charge-coupled device (CCD) camera. Effort has been put into collecting a large quantity of microdisks to investigate the discotic liquid crystalline phases, which can be readily probed by light scattering and microscope. In comparison, X-ray and neutron have to be used for the atomic liquid crystalline phase investigation.
69

Production of fuels and chemicals from biomass-derived oil and lard

Adebanjo, Adenike Omowunmi 25 February 2005
<p>Biomass derived oil (BDO) reforming with CO2 was carried out at 800oC under atmospheric pressure in a tubular fixed bed vertical reactor packed with quartz particles. The feed gas was a mixture of CO2 and N2 at various compositions with a flow rate of 30 to 60 cm3/min. The BDO flow rate was 5 g/h. The product gas consisted mostly of H2, CO, CO2, CH4 and C2H4.</p><p>The maximum production of synthesis gas (~76 mol%) was observed at a total carrier gas flow rate of 60 cm3/min and a mole fraction of CO2 in carrier gas of 0.1. Maximum hydrogen (42 mol%) and H2 to CO molar ratio (1.44) were obtained while using only N2 as the carrier gas at a flow rate of 50 cm3/min. In the range of residence time considered, CO2 was not consumed in BDO gasification at 800oC but helped to increase gas production at the expense of the char.</p><p>Pyrolysis of lard was performed to produce a diesel-like liquid and a high heating value gaseous fuel. Lard was fed into the reactor at 5 g/h using N2 (10-70 cm3/min) as carrier gas. Two particle size ranges of quartz particles (0.7-1.4 and 1.7-2.4 mm) were used as reactor packing material. The liquid product essentially consisted of linear and cyclic alkanes and alkenes, aromatics, ketones, aldehydes and carboxylic acids. The maximum yield for diesel-like liquid product (37g/100g lard) was obtained at 600oC, residence time of 1.5 s and packing particle size of 1.7- 2.4 mm. The liquid product obtained at 600oC, carrier gas flow rate of 50 cm3/min and quartz packing particle size of 0.7-1.4 mm has a cetane index of 46, specific gravity of 0.86, a heating value of 40 MJ/kg and cloud and pour points of 10 and -18 respectively. The heating value of the product gas ranged between 68 and 165 MJ/m3. This study shows that there is a potential for producing diesel-like liquid from pyrolysis of lard. It also identifies the pyrolysis of animal fats as a source of high heating value gaseous fuel.</p><p>Steam reforming of lard was performed at 500, 550, 600 and 800oC and at steam to lard mass ratios of 0.5 to 2.0. The maximum diesel-like liquid yield from the steam reforming process (39 g/100g of lard) was obtained at a steam to lard ratio of 1.5 and a temperature of 600oC. Higher cetane index (52) and lower viscosity (4.0 mPa.s at 40oC) were obtained by addition of steam. The net energy recovered from pyrolysis and steam reforming processes were 21.7and 21.9 kJ/g of lard respectively. Thus, the processes are energy efficient.</p><p>In comparison, lard is a better feedstock for the production of hydrogen, char, high heating value gas and high H2/CO ratio than BDO. On the other hand, BDO is the preferred feedstock for the production of synthesis gas with H2/CO in the vicinity of 1.</p>
70

Investigating the Effects of an MMP-inhibitory Biomaterial on the Host Inflammatory Response using an Air Pouch Mouse Model

Patel, Ritesh 13 January 2011 (has links)
An earlier approach to restore homeostatic levels of ECM degrading matrix metalloproteases (MMPs) by the Sefton Lab utilized hydroxamate-based MMP inhibitory (MI) beads. While the MI beads delayed ECM degradation in the context of skin wound healing, they caused elevated cell infiltration in a subcutaneous implant model. The primary goal of this project was to further investigate this finding using an air pouch implant model in mice and a different control group – methacrylic acid-based (MAA) beads. Exudate analysis indicated that the MI beads, implanted subcutaneously with gelatin discs, elicited a similar biological response as the MAA beads. Exudates corresponding to both biomaterials had similar cell counts and chemokine levels, which were greater than those corresponding to the control used earlier, poly-methyl methacrylate-based (PMMA) beads. Further, both MI and MAA beads activated infiltrating macrophages in the classical manner, and influenced the activity of an MMP8 catalytic domain in a similar manner.

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