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Din sökning på "swedish" gav 65513 sökträffar

Studies on the function of CD4CD25 regulatory T cells: An in vitro approach

Immunological self-tolerance is a state of the whole organism where deleterious responses are either avoided or regulated. Breaking of immunological tolerance will lead to autoimmune disease or chronic inflammatory conditions. T cell maturation in the thymus generates a peripheral T cell pool with an enormous TCR repertoire, from which specific T cells are selected and activated upon encounters wi

Multiple threat responses in zooplankton - from communities to individuals

Most organisms on Earth live a life where they are exposed to multiple and variable threats. In order to maximise survival they need to be able to perceive and respond to these threats. Two common threats that crustacean zooplankton are faced with are predation and ultraviolet radiation (UVR). To cope with these threats zooplankton use different strategies such as diel vertical migration and the a

Digital and Computed Musculoskeletal Radiography. A study on spatial resolution, diagnostic accuracy, image quality and radiation dose.

The aims of the study were to investigate the applications of digital radiography to musculoskeletal radiology. In the first part of the research, the diagnostic accuracy of digital images as compared to film-screen radiographs was studied and the spatial resolution requirements evaluated. Using computed radiography (CR), the pathological changes included were erosions, soft tissue swelling, peri

Expression and function of vascular estrogen receptors alpha and beta

Estrogen receptors (ER) are expressed not only in classical target organs for estrogen like breast and uterus, but also in male reproductive system as well as in non-reproductive organs such as brain, liver and bone. The functions of ER are quite well known in reproductive organs but less information is available regarding their function in vascular tissue. The objective of this thesis was to inve

Endothelial-leukocyte interactions

This thesis describes early inflammatory responses involving interactions between leukocytes and the endothelial lining of the blood vessel wall. An adhesion molecule, E-selectin, which is upregulated on interleukin-1 activated endothelium, was found to mediate rolling between leukocytes and endothelial cells in vivo. Immunohistochemistry revealed that E-selectin was preferentially expressed in ve

Echocardiographic assessment of atrioventricular plane displacement, Clinical application in patients with coronary artery disease, atrial fibrillation and aortic stenosis

Left atrioventricular plane displacement (AVPD) has been shown to correlate well with left ventricular (LV) systolic function measured as ejection fraction (EF). AVPD has also been shown to be related to diastolic performance. Other factors related to AVPD include age, heart rate, LV and atrial dimensions, myocardial thickness, bodysurface, and afterload. In this thesis the left AVPD was studied i

Ultrafast Dynamics in Ground and Excited States of Porphyrin Molecules

This thesis describes inter and intramolecular dynamics in porphyrin molecules. To create a basis for understanding the energy and electron transfer processes in photosynthesis, the ultrafast dynamics of monomeric chlorophyll a, chlorophyll b and bacteriochlorophyll a were studied with ultrashort laser pulses. The transient absorption spectra of all three molecules were found to have pronounced co

Reactivity of human omental blood vessels. Effects of 5-hydroxytryptamine, substance P and the intravenous anaesthetic propofol

Regulation of blood flow involves several endogenous substances and mechanisms, and exogenous substances may also affect the blood flow. In the present thesis, human omental blood vessels were investigated in vitro concerning (i) characteristics of 5-hydroxytryptamine (5-HT) receptors; (ii) mediators of substance P (SP)-induced relaxation; (iii) direct and indirect (via effects on sympathetic neur

Laboratory and stellar spectroscopy of the complex ions Fe+, Mo+, Th+ and U+

The new generation of high resolution astronomical instruments such as the Hubble Space Telescope (HST) or the Very Large Telescope (VLT) has renewed the demand for accurate atomic parameters like wavelengths, oscillator strengths and line profiles accompanied by reliable uncertainty estimates. Fourier transform spectroscopy has proven to be a powerful tool when measuring these parameters. In this

On the two forms of amylose-lipid complexes

This thesis is about the formation of amylose-lipid complexes, and their properties. Two forms of superstructures can be identified. Complex form I has more randomly distributed helices, while the structure of form II is crystalline and therefore exhibits the typical V-pattern in X-ray diffraction analyses. Form II has higher heat stability, and is produced by heating at a temperature at least suf

Plant Phosphoinositide Kinases. A Study of PtdIns 4-kinases and a PtdIns 4-phosphate 5-kinase.

Phosphoinositides are of particular interest in signal transduction processes as they can be sequentially phosphorylated and used as precursors for the intracellular messengers inositol trisphosphate (InsP3) and diacylglycerol (DAG) that in turn affects calcium levels and protein kinase cascades, eventually leading to a physiological response. The activity and regulation of PtdIns 4-kinases and Pt

An Investigation of Peroxidase Activity in Biomimetic and Biological Systems

In order to create a heme environment which permits biomimicry of heme-containing plant peroxidases and investigate the role played by the vinyl side chains of the porphyrin ring on the stability and, possibly, catalytic activity of model compounds, a number of new synthetic microperoxidases -– hemin-6(7)-gly-his methyl ester (HGH) and hemin-6(7)-gly-gly-his methyl ester (HGGH) and hemin-6,7-bis(g

Theoretical Studies of Simple Polar Fluids

Fluids composed of dipolar molecules are ubiquitous in nature, with water being the most prominent example. Due to their great importance and large complexity, a basic scientific understanding of the structure and thermodynamics of polar fluids is essential. In this thesis, simple polar model fluids are investigated with the aim of adding a bit to this understanding. In particular, the topics addr

Antidepressant drug effects in vivo: Focus on pharmacokinetic and pharmacodynamic responses in different experimental paradigms

Pharmacokinetic and pharmacodynamic activities of the antidepressants venlafaxine (VEN) and citalopram (CIT) were investigated in the portacaval shunted (PCS) rat, a model of chronic hepatic encephalopathy (HE), and normal/control rats. The levels of VEN in serum and brain were higher in PCS rats than in controls after a single injection and chronic treatment with VEN (10 mg/kg). After reducing th

Making 21st Century Maps Legible - Methods for Measuring and Improving the Legibility and Usability of Real-Time Maps

The research presented in this thesis has focused on methods for improving the legibility and usability of maps in real-time map services. The aim has been threefold: to create methods to increase the cartographic quality of maps in map services, to develop methods to measure the legibility, as perceived by the user, and to evaluate the quality of maps. Map services are becoming increasingly commo

Testing palaeomagnetic and 14C based geochronological methods in the Baltic Sea

The Baltic Sea is a continental shelf sea that is influenced by both river runoff and marine water. The two water masses are vertically stratified in the Baltic Sea, resulting in a positive, estuarine circulation system, which has undergone changes in the past due to isostatic uplift of the Baltic basin. For researchers to understand past changes in the marine environment of the Baltic Sea, a soun

Epidemiological aspects of tuberculosis in Guinea-Bissau, West Africa

Tuberculosis (TB) has plagued the humanity for several thousands of years. The bacteria causing TB is mainly spread from person to person as an aerosol transmission. It is estimated that one third of the world’s population is infected with the disease; about 10% of these will develop active TB during their lifetime. In year 2000, 8 million TB-cases were detected, of which 2 million died. Except fo

MRI evaluation and image processing in gel dosimetry. A study of selected MRI properties and image processing in 3D gel dosimetry.

Gel dosimetry is a new dosimetry method applied in radiation therapy. Gel dosimeters consist of a radiation sensitive gel, which can integrate absorbed doses from several radiation sources or beams. The dose to the gel can be evaluated by magnetic resonance imaging (MRI), a procedure that is the focus of the present thesis. A robust tool for the evaluation of the nonuniformity in MRI has been dev

Photosynthetic Oxygen Evolution - EPR studies of the manganese cluster of photosystem II

In this thesis, a new electron paramagnetic resonance (EPR) signal from photosystem II is presented. The signal is shown to originate from the S0 oxidation state of the oxygen-evolving complex (OEC). It is a Mn-derived signal displaying clear hyperfine structure, centered at g=2, and is significantly broader than the well-known multiline signal from the S2 state, indicating the presence of MnII in

Escherichia coli Fimbriae, Bacterial Persistence and Host Response Induction in the Human Urinary Tract

Urinary tract infections (UTI) are among the most common bacterial infections in humans. Symptomatic UTIs may be acute, recurrent or chronic but the most frequent form of UTI is asymptomatic bacteruria (ABU). In ABU, the mucosa remains inert, despite the presence of large bacterial numbers in urine. The difference in disease severity reflects the virulence of the infecting strain and the propensit