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MRI-based biophysical models are typically validated by comparison to ex-vivo histology of fixed tissue. The fixation process itself and the accompanied autolysis processes strongly modify tissue composition, and lead to MR signal changes, making the validation of biophysical models for in vivo MRI particularly challenging. To better understand the temporal evolution of the fixation process within
3D multi-gradient echo MRI can be used to estimate T1, T2*, PD and the magnetization transfer (MT), which is increasingly used for multi-parametricmapping (MPM) of human brain. The increased polarization at 7T compared to lower B0 allows for increased spatial resolution or reduced scantimes. However, SAR restrictions imposed on the MT pulse and B1 inhomogeneity pose challenges. In this work, we pr
DREAM is an ultra-fast multi-slice B1+-mapping technique based on the single-shot STEAM sequence. To study noise and bias related to slice-profiles, DREAM B1+-maps at 3.75 mm resolution were acquired at 7T in phantoms and in human brain with nominal flip angles (FA) between 20° and 90° of the two STEAM preparation pulses. B1+ was decreasing at actual FAs above 50°; noise became apparent at actual
The ability to determine the myelin water fraction (MWF) in vivo is essential to assessments of neurodevelopmental myelination and myelin damage in neurodegenerative diseases. The analysis of multi-exponential T2 decay data relies on the non-negative-least-squares (NNLS) fitting, which may be sensitive to the chosen fitting parameters. We performed simulations to explore the outcomes of NNLS under
Wind is a complex phenomenon and a critical fac-tor in assessing climatic conditions and pedestrian comfortwithin cities. To obtain spatial information on near-groundwind speed, 3D computational fluid dynamics (CFD) model-ling is often used. This is a computationally intensive methodwhich requires extensive computer resources and is time con-suming. By using a simpler 2D method, larger areas can b
We used satellite remote sensing data; fractionof photosynthetically active radiation absorbed by vegetation(fPAR) from the Moderate Resolution Imaging Spectrora-diometer (MODIS) in combination with tower eddy covari-ance and meteorological measurements to characterise theLight Use Efficiency parameter (ε)variability and the maxi-mumε(εmax)for two contrasting Canadian peatlands. Eight-
I språkutbildning vid svenska lärosäten finns det vanligtvis ett antal studenter i varje grupp som har det studerade språket som modersmål (L1), även om majoriteten utgörs av studerande som läser språket som främmande språk (L2). I vår studie undersöker vi erfarenheter av att undervisa denna typ av grupp genom semistrukturerade intervjuer med sex universitetslärare i franska, spanska och tyska. Un
Intravesical inoculation of gram negative bacteria or isolated bacterial products into mice induces an IL-6 response which can be measured within miutes of the infection.1,2 In such infections, IL-6 is initially detected in the urine and subsequently in the serum. Similar IL-6 responses were found in human patients deliberately colonized in the urinary tract with E. coli Hu7343. IL-6 was secreted
T-helper 2 (Th2) cell responses defend against parasites. Although dendritic cells (DCs) are vital for the induction of T-cell responses, the DC subpopulations that induce Th2 cells in the intestine are unidentified. Here we show that intestinal Th2 responses against Trichuris muris worms and Schistosoma mansoni eggs do not develop in mice with IRF-4-deficient DCs (IRF-4f/f CD11c-cre). Adoptive tr
Lymphocytes are the key cells of the adaptive immune system that provide antigen-specific responses tailored to the context of antigen exposure. Through cytokine release and antibody production, lymphocytes orchestrate and amplify the recruitment and function of other immune cells and contribute to host defense against invading pathogens and the pathogenesis of many inflammatory diseases. Lymphocy
Chemokines constitute a large family of low-molecular-weight proteins (∼10 kDa in size), recognized primarily for their role in directing leukocyte migration under both homeostatic and inflammatory settings. The chemokine CCL25 displays a unique and highly restricted expression pattern compared with other chemokine family members. In the steady state, CCL25 is expressed at high levels primarily in
The mucosal lymphocyte integrin α(E)(CD103)β7 is thought to be important for intraepithelial lymphocyte (IEL) localization or function. We cloned the murine integrin gene encoding α(E), localized it to chromosome 11, and generated integrin α(E)-deficient mice. In α(E)(-/-) mice, intestinal and vaginal IEL numbers were reduced, consistent with the known binding of α(E)β7, to E-cadherin expressed on
Microbial attachment to mucosal surfaces is a first step in mucosal infection. Specific interactions between microbial surface ligands and host receptors influence the distribution of microbes in their sites of infection. Adhesion has often been regarded as a sufficient end point, explaining tissue tropism and bacterial persistence at mucosal sites. Adherence, however, is also a virulence factor t
Urine and serum interleukin (IL)-6 and IL-8 responses were higher in children with febrile urinary tract infection (n = 61) than in those with asymptomatic bacteriuria (n = 39). By univariate analysis, cytokine levels were related to age, sex, reflux, renal scarring, urine leukocytes, C- reactive protein (CRP), erythrocyte sedimentation rate (ESR), and bacterial properties (P fimbriae but not hemo
This study analysed the effects of immunoregulatory cytokines on uroepithelial cell cytokine responses. The A-498 human kidney cell line was treated with the interleukins IL-2, IL-4, IL-5, IL-10, IL-12, IL-13, interferon gamma (IFN-α) and transforming growth factor beta (TGF-β1). Secreted IL-6 and IL-8 were quantitated by enzyme-linked immunoabsorbent assay (ELISA) and bioassay; IL-6 and IL-8 mRNA
Type 1 fimbriae are adhesion organelles expressed by many Gram-negative bacteria. They facilitate adherence to mucosal surfaces and inflammatory cells in vitro, but their contribution to virulence has not been defined. This study presents evidence that type 1 fimbriae increase the virulence of Escherichia coli for the urinary tract by promoting bacterial persistence and enhancing the inflammatory
Neutrophil influx to mucosal surfaces represents one of the earliest inflammatory responses to mucosal infection. We have been studying external interactions with urinary tract epithelial cells in an attempt to understand the molecular mechanisms behind this process. Uropathogenic Escherichia coli induced urinary tract epithelial cells to secrete the neutrophil chemoattractant interleukin-8 (IL-8)
During bacterial infections at mucosal sites, neutrophils migrate to the mucosa and cross the epithelial barrier. We have examined neutrophil migration across Escherichia coli-stimulated uroepithelial cell layers in an attempt to more fully understand this process. Stimulation of uroepithelial cells with E. coli or interleukin-1α (IL-1α) induced transepithelial neutrophil migration in a time- and
Localized at the border between the external environment and the internal tissue, epithelial cells are exposed to stimulants from two directions. Microorganisms in the lumen can activate the transcription of cytokine mRNA and cytokine secretion, and cytokines in the mucosal environment can modify endogenous and microbially induced epithelial cytokine responses. Epithelial cells thus actively parti
