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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.
101

Evaluation of Novel Materials for Wound Healing

Jacobsson, Lena January 2009 (has links)
<p>Rapid wound healing is important to regain the skins protective function after injury. Studies have shown that enamel matrix proteins (EMP) have many desirable effects which may accelerate wound healing [Bosshardt <em>et al.</em> 2008].</p><p> </p><p>Polymers (Polymer A, B and C) were formed into a mat form, with or without incorporated enamel matrix derivative (EMD) (Collaboration partner). The materials may be suitable for wound care and drug delivery systems.</p><p> </p><p>Protein release tests were performed on samples incubated in physiological-like solution using pyrogallol red staining, ultraviolet (UV) spectrophotometer and high-performance liquid chromatography (HPLC). Protein was detected in Polymer A material samples, compared to a reference material sample, using pyrogallol red staining. An in vitro experiment showed that normal human dermal fibroblasts (NHDF) cultivated with Polymer A material (with EMD) had significantly higher viability than NHDF cultivated with reference material (Polymer A without EMD) and comparable viability to fibroblasts grown with either 0.1 mg EMD in solution or with 10% fetal calf serum. Images taken of Polymer A material, with incorporated Fluorescein isothiocyanate- (FITC) labeled EMD, indicate a homogenous distribution of EMD peptides and/or EMD aggregates throughout the material. A dressing which contains an active substance may have clinical promise for wound care applications.</p>
102

Regulation of HIV-1 mRNA Processing by Cellular Splicing Factors

Tranell, Anna January 2012 (has links)
According to UNAIDS there were 34 million people living with human immunodeficiency virus (HIV) infection at the end of 2010. HIV is the causative agent of acquired immunodeficiency syndrome (AIDS) and the number of people dying of AIDS-related causes at the end of 2010 was 1.8 million. Due to the high mutability of the virus, there is a constant need for new approaches to attack the virus. Splicing of HIV-1 pre-mRNA is a highly regulated process. In order to produce all mRNAs needed to be infectious HIV-1 utilizes alternative splicing ­- from one single transcript more than 35 differently spliced mRNAs can be produced. A new approach to fight HIV-1 could be to interfere with the essential splicing. In this thesis, I describe the regulation of HIV-1 pre-mRNA splicing. SR proteins are involved in the regulation of splicing, both in an early and a late stage. We find that the intracellular concentration of SR proteins is of great importance for HIV-1 to be able to produce the correct amounts of mRNAs. Variations in concentrations of SR proteins lead to big changes in the HIV-1 pre-mRNA splicing pattern. The functions of HIV-1 protein Vpr are diverse and it is essential in vivo. HIV-1 vpr mRNA 13a7 is partially spliced, containing an intron, and the regulation of it is not fully understood. We find that SRp55 and SRp75 induce the production of HIV-1 vpr mRNA 13a7 by inhibiting splice donor 3. We also conclude that this inhibition at least for SRp55 is due to an interaction with the viral RNA element GAR. In the presence of SRp55 we also see an increase in cytoplasmic amounts of intron containing vpr mRNA due to increased nuclear export. Our results show that SRp55 can have several functions in the regulation of HIV-1 splicing: by inhibiting splice donors and by facilitating the export of incompletely spliced mRNAs to the cytoplasm. In conclusion, this thesis describes SRp55 as a regulator of HIV-1 vpr mRNA, both in splicing as well as in nuclear export. These discoveries provide an insight into the regulation of HIV-1 mRNA processing.
103

Progress Towards the Synthesis of a Pentasaccharide Derivative Found in Spergularia ramosa

Anthonipillai, Stefi 20 November 2012 (has links)
There has been increasing interest in the syntheses of carbohydrates due to their profound role in various biological processes and thus their potential in drug development. Various methods have been developed for the preparation of these oligosaccharides from simpler carbohydrate derivatives both chemically and enzymatically but they must be carefully applied to obtain the desired linkages. The main method that has been used to control the regioselectivity of glycosylations is protecting group chemistry. Unfortunately this requires additional steps lengthening the synthesis sequence. Extensive literature has shown the ability for carbohydrate recognition via organoboron methods through selective binding and their ability to undergo regioselective glycosylation through sugar-derived boronate esters. Exploiting these factors and in extension of previous work done in our laboratory on borinic acid- and boronic acid-catalyzed regioselective glycosylations of carbohydrate derivatives, we proposed a target oriented synthesis of a pentassacharide moiety found in four saponins isolated from Spergularia ramosa.
104

Progress Towards the Synthesis of a Pentasaccharide Derivative Found in Spergularia ramosa

Anthonipillai, Stefi 20 November 2012 (has links)
There has been increasing interest in the syntheses of carbohydrates due to their profound role in various biological processes and thus their potential in drug development. Various methods have been developed for the preparation of these oligosaccharides from simpler carbohydrate derivatives both chemically and enzymatically but they must be carefully applied to obtain the desired linkages. The main method that has been used to control the regioselectivity of glycosylations is protecting group chemistry. Unfortunately this requires additional steps lengthening the synthesis sequence. Extensive literature has shown the ability for carbohydrate recognition via organoboron methods through selective binding and their ability to undergo regioselective glycosylation through sugar-derived boronate esters. Exploiting these factors and in extension of previous work done in our laboratory on borinic acid- and boronic acid-catalyzed regioselective glycosylations of carbohydrate derivatives, we proposed a target oriented synthesis of a pentassacharide moiety found in four saponins isolated from Spergularia ramosa.
105

Electrochemical detection of chemical warfare agent simulants

Marenco, Armando J 04 December 2009
This work attempted to detect chemical warfare agent (CWA) simulants via electrochemistry utilizing two approaches. The first approach consisted of a ferrocene (Fc) amino acid derivative film on Au surfaces. The molecule [(BocHN)Fc(CO)CSA]2 was electrodeposited onto Au microelectrodes through a SAu bond. Once immobilized, the Fc amino acid derivative was Boc deprotected allowing for the amino group to react with the target molecule. Detection of the target simulant was monitored by cyclic voltammetry (CV) while following the formal potential of the Fc molecule, which is influenced by its immediate electronic microenvironment. Reaction with either 1 mM diethyl cyanophosphonate (DECP) or 2 chloroethyl ethyl sulfide (2 CEES), both effectively simulants for the CWAs Tabun nerve agent and blistering sulfur mustard respectively, was not observed. However, detection of 1 mM acetyl chloride was achieved by observing a potential anodic shift from 217 ± 6 mV, for the Boc deprotected form, to 388 ± 7 mV for the reacted state of the molecule. The lack of reactivity with the Fc amino acid system was hypothesized as a kinetic issue.<p> In the second approach, the electrochemistry of gas generated naked Ag nanoparticles (NPs) deposited on indium tin oxide covered glass plates is compared to bulk polycrystalline Ag. The nano specific electrochemistry of Ag NPs has been identified and includes the preferential formation of â oxides. In 100 mM KOH supporting electrolyte, disruption of â oxide formation is exploited to test for the presence of 1 mM DECP resulting in the dissolution of Ag via cyanide complexes leading to a CV signal decrease. While in 8.0 M KOH, â oxide formation is enhanced leading to testing capabilities for 1 mM 2 CEES resulting in the disappearance of the â oxide peak and the appearance of surface oxide peak during CV. Analogous electrochemistry is not observed on polycrystalline bulk Ag.
106

Evaluation of Novel Materials for Wound Healing

Jacobsson, Lena January 2009 (has links)
Rapid wound healing is important to regain the skins protective function after injury. Studies have shown that enamel matrix proteins (EMP) have many desirable effects which may accelerate wound healing [Bosshardt et al. 2008]. Polymers (Polymer A, B and C) were formed into a mat form, with or without incorporated enamel matrix derivative (EMD) (Collaboration partner). The materials may be suitable for wound care and drug delivery systems. Protein release tests were performed on samples incubated in physiological-like solution using pyrogallol red staining, ultraviolet (UV) spectrophotometer and high-performance liquid chromatography (HPLC). Protein was detected in Polymer A material samples, compared to a reference material sample, using pyrogallol red staining. An in vitro experiment showed that normal human dermal fibroblasts (NHDF) cultivated with Polymer A material (with EMD) had significantly higher viability than NHDF cultivated with reference material (Polymer A without EMD) and comparable viability to fibroblasts grown with either 0.1 mg EMD in solution or with 10% fetal calf serum. Images taken of Polymer A material, with incorporated Fluorescein isothiocyanate- (FITC) labeled EMD, indicate a homogenous distribution of EMD peptides and/or EMD aggregates throughout the material. A dressing which contains an active substance may have clinical promise for wound care applications.
107

Inflation derivatives pricing with a forward CPI model

Ruest, Eric January 2010 (has links)
The Zero-Coupon Inflation Indexed Swap (ZCIIS) is a derivative contract through which inflation expectations on the Consumer Price Index (CPI) are actively traded in the US. In this thesis we consider different ways to use the information from the ZCIIS market for modeling forward inflation in a risk-neutral framework. We choose to implement a model using a Monte Carlo methodology that simulates the evolution of the forward CPI ratio. We prefer this approach for its flexibility, ease of implementation, instant calibration to the ZCIIS market and intrinsic convexity adjustment on the inflation-linked payoff. Subsequently, we present a series of results we obtain when modeling a chain of consecutive CPI ratios for simulating the evolution of spot inflation. Furthermore, we use this for pricing inflation caplets and floorlets. Finally, we use the intuition gained from this exercise to analyse our results for pricing inflation caps.
108

Electrochemical detection of chemical warfare agent simulants

Marenco, Armando J 04 December 2009 (has links)
This work attempted to detect chemical warfare agent (CWA) simulants via electrochemistry utilizing two approaches. The first approach consisted of a ferrocene (Fc) amino acid derivative film on Au surfaces. The molecule [(BocHN)Fc(CO)CSA]2 was electrodeposited onto Au microelectrodes through a SAu bond. Once immobilized, the Fc amino acid derivative was Boc deprotected allowing for the amino group to react with the target molecule. Detection of the target simulant was monitored by cyclic voltammetry (CV) while following the formal potential of the Fc molecule, which is influenced by its immediate electronic microenvironment. Reaction with either 1 mM diethyl cyanophosphonate (DECP) or 2 chloroethyl ethyl sulfide (2 CEES), both effectively simulants for the CWAs Tabun nerve agent and blistering sulfur mustard respectively, was not observed. However, detection of 1 mM acetyl chloride was achieved by observing a potential anodic shift from 217 ± 6 mV, for the Boc deprotected form, to 388 ± 7 mV for the reacted state of the molecule. The lack of reactivity with the Fc amino acid system was hypothesized as a kinetic issue.<p> In the second approach, the electrochemistry of gas generated naked Ag nanoparticles (NPs) deposited on indium tin oxide covered glass plates is compared to bulk polycrystalline Ag. The nano specific electrochemistry of Ag NPs has been identified and includes the preferential formation of â oxides. In 100 mM KOH supporting electrolyte, disruption of â oxide formation is exploited to test for the presence of 1 mM DECP resulting in the dissolution of Ag via cyanide complexes leading to a CV signal decrease. While in 8.0 M KOH, â oxide formation is enhanced leading to testing capabilities for 1 mM 2 CEES resulting in the disappearance of the â oxide peak and the appearance of surface oxide peak during CV. Analogous electrochemistry is not observed on polycrystalline bulk Ag.
109

Problem-Solving Strategies in Calculus

Cheng, Chien-Min 18 July 2012 (has links)
This paper investigates methods of solving calculus problems in Putnam Mathematical Competition.Chapter 2 presents the methods of finding limits, and the most important theorems of continuity---Intermediate Value Theorem and Extreme Value Theorem. Chapter 3 introduces to the properties of derivatives, and the application problems change from the basic problems of derivative. It contains the tangent line and the rate and the meaning of derivative on the geometry.In this chapter also includes the most important theorem---Mean Value Theorem---in derivatives. Chapter 4 introduces to the properties of integral, and the application problems change from the basic problems of integral. There are the Fundamental Theorem of Calculus, Arc length, area, volume and the mass moment and centroid of physical. Chapter 5 investigates the integral techniques of the various forms of possible form for the integral function, to take the integral becomes relatively easy to calculate. In addition to the common variable transformation, also describes how to use the Leibniz Rule for solving integrating. In Chapter 6, it presents that how to determine terms of sequence and its limit, and introduces the infinite summation and to determine convergence or divergence of series.
110

A Study on the ¡§Play¡¨ of Experienced Amateur and the Carnival of Youtube Videos

Chuang, Yu-Ju 31 July 2012 (has links)
As a new communication technology, Internet makes users play the role both as audiences and producers of messages. After Youtube published, the trend of amateurs¡¦ works quickly sprung up. Amateurs produce original creations and derivative works, and sharing their ideas by Youtube to hold a carnival in the cyber world. Some experienced amateurs become the favorite of news media, and even get the chance to communicate with professional movie makers. The purpose of this research is to provide Youtube video creators some success examples and key elements to follow. Based on the amateurs¡¦ point of views, this research studied on the ¡§play¡¨ experiences and the communication pleasure of experiences amateurs. By observing Youtube website, this research also found out the carnival of amateur videos. This research takes two qualitative approaches. First, by conducting five interviews, the ¡§play¡¨ experiences and the communication pleasure of experienced amateurs are discussed. To develop an understanding of the carnival of Youtube videos, researcher observed the contents, click rates, and discussions of users. The findings of this research are that the experienced amateurs have long-term accumulations of video making which combine entertaining and learning. Their communication pleasures come from the behavior of creation, and the interaction with online fans and offline friends. As the main strategy of Bakhtin¡¦ carnival theory, parody also becomes a welcomed idea of Youtube videos. But the experienced amateurs emphasized that there lays more serious core ideas in the videos, and those are the main issues should be known.

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