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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.
151

Biomarker Discovery in Diabetic Nephropathy by Targeted Metabolomics

Lundin, Ulrika January 2008 (has links)
Diabetic nephropathy is a chronic kidney disease and one of the more severe complications from diabetes mellitus type 2. The glomerular and tubular dysfunctions usually lead to end stage renal disease and the treatments of these patients (dialysis, kidney transplants) are a huge economic burden for the society. Due to an epidemiologic increase of type 2 diabetes, conventional diagnostic markers like creatinine and albumin are not sufficient, since they are only able to identify already existing kidney damage. With targeted metabolomics, the analysis of small molecules produced from metabolism, this project aimed at finding novel and more sensitive metabolic biomarkers from several different classes of metabolites. The different assays were performed with flow injection analysis, high performance liquid chromatography, gas chromatography and mass spectrometry, and with principal component analysis and discriminant analysis, up-and down-regulated metabolites could be identified and their respective biochemical pathways, if possible, explained. In diabetics significantly elevated concentrations of very long chain fatty acids (impaired peroxisomal β-oxidation), urinary sugars and acylcarnitines in plasma could be recognized. Markers indicating kidney damage included significantly increased plasma concentrations of asymmetric dimethylarginine (inhibition of nitric oxide synthase resulting in decreased endothelial functionality) and histamine (indication of uremic pruritus). Oxidative stress was also found to be a potential prognostic marker as indicated by the raised methionine-sulfoxide to methionine ratio in nephrotic patients. To summarize, this project succeeded in identifying metabolic biomarkers both for diabetes type 2 and nephropathy, which in the future might become important tools in slowing down progression or diagnosing these diseases.
152

Classical Antifolates: Synthesis of 5-Substituted, 6-Substituted and 7-Substituted Pyrrolo[2,3-d]Pyrimidines as Targeted Anticancer Therapies

Wang, Yiqiang 22 April 2015 (has links)
This dissertation comprises an introduction, background and current research progress in the area of classical antifolates as the targeted anticancer therapies.<br>In this study, twelve series of classical 5-, 6- and 7-substituted pyrrolo[2,3-d]pyrimidines were designed and synthesized. Extensive structure modifications of the pyrrolo[2,3-d] pyrimidine scaffold were investigated to determine selective transport via FR or/and PCFT and tumor targeted antifolates with GARFTase or multiple folate metabolizing enzyme inhibition.<br>The design strategies employed include: variation of the side chain substitution position (5-,6- and 7-substituted); variation of the side chain length (n=1-6); isosteric replacement of the 1,4-disubstituted phenyl ring with 1,2- and 1,3- disubstituted phenyl ring and 2,5- disubstituted thiophenyl ring; replacement the L-glutamate with variation at the á and ã carboxylic acids.<br>As a part of this study, a total of one hundred and fifty six new compounds (including new intermediates) were synthesized and separated. Of these, twelve series consisting of forty two classical antifolate final compounds were submitted for biological evaluation. In addition, bulk synthesis of some potent final compounds (2, 2.0 g; 161, 500 mg; 175, 1.0 g; 166, 500 mg; 194, 500 mg) was carried out to facilitate in vivo evaluation.<br>More importantly, a new Heck coupling of the thiophene iodide 301 and allyl alcohols to synthesize aldehydes in one step was discovered. Due to its potential use in analog synthesis of clinically used antifolates such as RTX and PMX, this mild conditioned and easy to handle Heck coupling reaction is highly attractive.<br>During this study, the SAR of folate transporters (RFC, FR and PCFT) and GARFTase inhibitors were extensively explored. The 6-substituted straight chain compound 166 (n=7) was extremely potent against KB tumor cells (IC50=1.3 nM, about 80-fold more potent than clinically used PMX) without any RFC activity. The 5- substituted phenyl compound 175 (n=4) showed AICARFTase as the primary target with potent KB tumor cell inhibition (IC50=7.9 nM, about 8-fold more potent than PMX) and also indirectly inhibited the mTOR pathway leading to tumor cell apoptosis. Due to their potent antitumor activities, these two compounds serve as leads for future structural optimization. / Mylan School of Pharmacy and the Graduate School of Pharmaceutical Sciences; / Medicinal Chemistry / PhD; / Dissertation;
153

Acute neuro-endocrine profile and prediction of outcome after severe brain injury

Olivecrona, Zandra, Dahlqvist, Per, Koskinen, Lars-Owe January 2013 (has links)
Object: The aim of the study was to evaluate the early changes in pituitary hormone levels after severe traumatic brain injury (sTBI) and compare hormone levels to basic neuro-intensive care data, a systematic scoring of the CT-findings and to evaluate whether hormone changes are related to outcome. Methods: Prospective study, including consecutive patients, 15-70 years, with sTBI, Glasgow Coma Scale (GCS) score <= 8, initial cerebral perfusion pressure > 10 mm Hg, and arrival to our level one trauma university hospital within 24 hours after head trauma (n = 48). Serum samples were collected in the morning (08-10 am) day 1 and day 4 after sTBI for analysis of cortisol, growth hormone (GH), prolactin, insulin-like growth factor 1 (IGF-1), thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), follicular stimulating hormone (FSH), luteinizing hormone (LH), testosterone and sex hormone-binding globulin (SHBG) (men). Serum for cortisol and GH was also obtained in the evening (17-19 pm) at day 1 and day 4. The first CT of the brain was classified according to Marshall. Independent staff evaluated outcome at 3 months using GOS-E. Results: Profound changes were found for most pituitary-dependent hormones in the acute phase after sTBI, i.e. low levels of thyroid hormones, strong suppression of the pituitary-gonadal axis and increased levels of prolactin. The main findings of this study were: 1) A large proportion (54% day 1 and 70% day 4) of the patients showed morning s-cortisol levels below the proposed cut-off levels for critical illness related corticosteroid insufficiency (CIRCI), i.e. < 276 nmol/L (= 10 ug/dL), 2) Low s-cortisol was not associated with higher mortality or worse outcome at 3 months, 3) There was a significant association between early (day 1) and strong suppression of the pituitary-gonadal axis and improved survival and favorable functional outcome 3 months after sTBI, 4) Significantly lower levels of fT3 and TSH at day 4 in patients with a poor outcome at 3 months. 5) A higher Marshall CT score was associated with higher day 1 LH/FSH-and lower day 4 TSH levels 6) In general no significant correlation between GCS, ICP or CPP and hormone levels were detected. Only ICPmax and LH day 1 in men was significantly correlated. Conclusion: Profound dynamic changes in hormone levels are found in the acute phase of sTBI. This is consistent with previous findings in different groups of critically ill patients, most of which are likely to be attributed to physiological adaptation to acute illness. Low cortisol levels were a common finding, and not associated with unfavorable outcome. A retained ability to a dynamic hormonal response, i.e. fast and strong suppression of the pituitary-gonadal axis (day 1) and ability to restore activity in the pituitary-thyroid axis (day 4) was associated with less severe injury according to CT-findings and favorable outcome.
154

A Ribosome-inactivating Protein Toxin as a Template for Cancer Drug Discovery

Cheung, Melissa 10 December 2012 (has links)
Cancer cells display aberrant receptors on their surface that can serve as targets for the development of directed drug therapies. As such, our group has utilized two parallel approaches to redirect the cytotoxic properties of a ribosome-inactivating protein (RIP), Shiga-Like Toxin 1 (SLT 1), by altering its receptor specificity to target and kill cancer cells. The first combinatorial protein library was constructed such that a randomized 7 AA long peptide was inserted within the cytotoxic domain (A chain) of SLT-1. A high-throughput protein-based screening campaign identified a novel A chain toxin variant (named SLT 1AIYSNKLM) capable of targeting and killing human melanoma cells. This variant harbours a peptide insert (IYSNKLM) that directs the A chain to kill human melanoma cell lines. Equilibrium binding studies using 125I-radiolabeled SLT-1AIYSNKLM were conducted to determine the equilibrium binding constant and receptor density on 518-A2 human melanoma cells. When injected into SCID mice bearing a human melanoma xenograft, nanoSPECT/CT imaging as well as the biodistribution profile showed marked tumour uptake and retention of the radiolabeled toxin variant. Furthermore, preliminary experiments have shown that the SLT-1AIYSNKLM receptor is a protein, highlighting the potential for this method to be used in the discovery of novel biomarkers. A second approach was employed to demonstrate that our toxin-based combinatorial library system can be adapted to target known cancer biomarkers. Specifically, SLT-1 A chain variants harbouring 12-residue inserts were expressed in a phage display library. The library was screened against cell lines expressing the human colon cancer marker carcinoembryonic antigen (CEA; CD66e; CEACAM-5) to identify candidates that not only targeted, but internalized into cancer cells within a 1 h period. Variant, CSTA-10, was found to kill CEA-expressing BxPC-3 cells. Overall, the directed evolution of an RIP template such as SLT-1 represents a novel and powerful strategy for the identification of tumour-targeted toxin variants.
155

Human Rights and the War Against International Terrorism: A War Without Rights?

Cho, Harry Yeon 12 January 2010 (has links)
The United States has justified targeted operations against suspected terrorists as a legitimate tool in the war against terrorism. In response to international criticism that a November 2002 targeted killing operation in Yemen violated human rights standards, the US asserted that the right to life was suspended during war. While this assertion is prima facie incorrect, many legal experts, scholars and authors agree in principle that a military response to international terrorism -- along with the concomitant dilution of the right to life -- is not only appropriate, but also complies with international law. However, the modern jus ad bellum limit the circumstances in which a state may lawfully resort to armed force. A fulsome understanding of international humanitarian law and the characteristics of groups such as Al Qaeda reveals that international law does not permit states to employ their military forces to responde to the international crime of international terrorism.
156

Human Rights and the War Against International Terrorism: A War Without Rights?

Cho, Harry Yeon 12 January 2010 (has links)
The United States has justified targeted operations against suspected terrorists as a legitimate tool in the war against terrorism. In response to international criticism that a November 2002 targeted killing operation in Yemen violated human rights standards, the US asserted that the right to life was suspended during war. While this assertion is prima facie incorrect, many legal experts, scholars and authors agree in principle that a military response to international terrorism -- along with the concomitant dilution of the right to life -- is not only appropriate, but also complies with international law. However, the modern jus ad bellum limit the circumstances in which a state may lawfully resort to armed force. A fulsome understanding of international humanitarian law and the characteristics of groups such as Al Qaeda reveals that international law does not permit states to employ their military forces to responde to the international crime of international terrorism.
157

Examining Tracking Stock Restructuring and Their Effect on Short - Run Excess Returns

Lau, Kwendy 01 January 2011 (has links)
This paper examines tracking stock issuances, a relatively uncommon method of equity restructuring. I utilize likely the entire population of tracking stock issuances on US exchanges – from the first ever in October 1984 to the most recent one in November 2009 – in order to analyze the effect that they have on the shortrun excess returns of issuing companies. I analyze the excess returns of companies that issue tracking stock that trade in the US, one year before and one year after completion of their restructuring. The results of this paper indicate that companies perform worse relative to a benchmark market index in the year following their tracking stock restructuring. However, it is important to note that the number of observations studied is relatively small, as there have been only 41 issuances of tracking stock since the first recorded case. This suggests that more data and greater research are necessary in order to more accurately measure the effects of tracking stock restructurings. With the limited data available, I find that there is a statistically significant decrease in excess stock returns following tracking stock issuances.
158

Behavioural advertising on Facebook : the users perspective regarding leisure industry

Desfougères, Jean-Marc, Bloux, Valentin January 2011 (has links)
Title: Behavioural advertising on Facebook: The user perspective regarding leisure industry. Authors: Jean-Marc Desfougères and Valentin Bloux Supervisor: Albert Thor Magnusson Level: Bachelor Thesis in Business Administration Marketing Key Words: Behavioural advertising, Facebook, privacy, online consumer behaviour, social network, leisure industry, targeting. Purpose: study how a specific age bracket of Facebook users perceives the leisure industry behavioural advertising on this social networking site. Method: This thesis follows a deductive approach. We are using secondary data from books, articles and studies but also primary data thanks to a questionnaire; which allows us to answer our purpose. Theoretical Framework: First define the online consumer behaviour and its characteristics through existing models and then define behavioural advertising, how is the leisure industry using this marketing tool and what are the drawbacks of such practices. Conclusion: The authors conclude that Facebook users are more and more aware of the use of behavioural advertising. But due to a lack of education about such marketing techniques the 18-30 years old tend to adopt mostly strict privacy settings with the intention to block those advertisements. The privacy issue is important and even if the users seems to be interested in the offers of the leisure industry there is still a long way before obtaining a full acceptance of this practice. Then are presented the contributions given and the further research possible regarding this topic.
159

How to create value through strategic product sample promotions : A L'Oréal case study

Jedenmark, Maria, Eckerbom, Mikaela January 2012 (has links)
The Swedish beauty industry face challenges with product samples as a promotion technique. The lack of a defined strategy results in a random distribution, which leads to weak ROI. However, product samples could be used proactively as a strategic marketing tool creating long-term brand value. This thesis provides a framework for L’Oréal to fulfill their objectives of using product samples – from strategy formation to tactical practice. Davies’s (1992) model “Using promotions as part of a strategic plan” is used as a sorting mechanism. We created a three-step process based on the model as a structure for this thesis: strategy preparation, strategy implementation, and strategy follow-up. Qualitative interviews and a quantitative survey proved that different product sample types require different strategies depending on the aim of the promotion. As a complement, targeted product samples via GlossyBox enabled L’Oréal to gain market insight and use product samples more strategically.
160

Synthesis Of Poly(dl-lactic-co-glycolic Acid) Coated Magnetic Nanoparticles For Anti-cancer Drug Delivery

Tansik, Gulistan 01 February 2012 (has links) (PDF)
One of the main problems of current cancer chemotherapy is the lack of selectivity of anti-cancer drugs to tumor cells which leads to systemic toxicity and adverse side effects. In order to overcome these limitations, researches on controlled drug delivery systems have gained much attention. Nanoscale based drug delivery systems provide tumor targeting. Among many types of nanocarriers, superparamagnetic nanoparticles with their biocompatible polymer coatings can be targeted to an intented site by an external magnetic field. Thus, the drug can be carried to the targeted site safely. The aim of this study is to prepare poly(dl-lactic-co-glycolic acid) (PLGA) coated magnetic nanoparticles and load anti-cancer drug, doxorubicin to them. For this purpose, magnetite (Fe3O4) iron oxide nanoparticles were synthesized as a magnetic core material (MNP) and then coated with oleic acid. Oleic acid coated MNP (OA-MNP) was encapsulated into PLGA. Effects of different OA-MNP/PLGA ratios on magnetite entrapment efficiency were investigated. Doxorubicin loaded magnetic polymeric nanoparticles (DOX-PLGA-MNP) were prepared. After the characterization of prepared nanoparticles, their cytotoxic effects on MCF-7 cell line were studied. PLGA coated magnetic nanoparticles (PLGA-MNP) had a proper size and superparamagnetic character. The highest magnetite entrapment efficiency of PLGA-MNP was estimated as 63 % at 1:8 ratio. Cytotoxicity studies of PLGA-MNP did not indicate any notable cell death between the concentration ranges of 2 and 250 &mu / g ml-1. It was observed that DOX-PLGA-MNP showed significant cytotoxicity on MCF-7 cells compared to PLGA-MNP. The results showed that prepared nanoparticles have desired size and superparamagnetic characteristics without serious toxic effects on cells. These nanoparticles may be suitable for targeted drug delivery applications. The findings obtained from drug studies may contribute to further work.

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