Sökresultat

Filtyp

Din sökning på "*" gav 534767 sökträffar

Resonant photoemission of oxidized Yb : Experiment and theory

The oxidation-induced valence change of Yb leads to a single 4f hole in the ground state. The creation of the 4f13 configuration which does not exist for any pure rare-earth metal makes it possible to analyze the 4d4f Fano resonance for a simple system experimentally as well as theoretically. Calculated Fano profiles for the 4f12 final-state multiplets are in good agreement with photoemission meas

Importance of the stomach in maintaining calcium homeostatis in the rat

The stomach helps to maintain calcium homoeostasis by making dietary calcium accessible for uptake in the intestines, although the effect of the stomach on calcium homoeostasis is poorly understood. We examined the effect on blood calcium of gastric surgery in the rat. Within three weeks gastrectomy and fundectomy (excision of the acid producing part of the stomach) induced a slight lowering of th

The effect of high or low dietary calcium on bone and calcium homeostasis in young male rats.

Young male rats (100 g body weight) were fed diets containing varying amounts of calcium. Body weight and bone development were studied together with various endocrine parameters, including blood levels of Ca2+, calcitonin, parathyroid hormone, vitamin D, and gastrin, and the enterochromaffin-like (ECL) cell-related parameters gastric mucosal histidine decarboxylase activity and histamine concentr

Rat stomach ECL-cell histidine decarboxylase activity is suppressed by ergocalciferol but unaffected by parathyroid hormone and calcitonin.

The ECL cells are peptide hormone-producing cells, rich in histamine and chromogranin A (CGA)-derived peptides, that operate under the control of gastrin. Gastrin and the ECL cells form a functional unit, the gastrin-ECL-cell axis. The aims of the present study were to examine (1) if calcitonin (CT), parathyroid hormone (PTH) and vitamin D affect the gastrin-ECL-cell axis (by measuring the activit

Inshore Commercial Fisheries in the Service Economy : Session 1 Small-Scale Fisheries Research - towards sustainable fisheries using a multi-entry perspective

The study frames a traditional industry in transition with the aim to understand the ways in which a work-identity is formed in the service economy along the west coast of Sweden. More specifically, we want to understand how diversified inshore commercial fisheries are discursively established and negotiated as a service enterprising subject in three everyday relationships; authorities, customers

Quantitative Modeling of Gain in Quantum Cascade Lasers under Operational Intensities

Ljus består av elektromagnetiska vågor som pulserar genom universum med olika frekvenser. Vanligt ljus, som det som kommer från solen och från våra lampor, innehåller ett spektrum av många olika frekvenser. De olika vågornas toppar och dalar svänger inte heller i takt, utan är förskjutna i förhållande till varandra. I laserljus däremot, svänger alla vågor samtidigt upp och ner och med samma frekveThis thesis adresses modeling of quantum cascade lasers using non-equilibrium Green’s functions. Focus lies on the quantitative modeling of the gain when the systems are exposed to strong laser fields, as under realistic opertional conditions. In the first part, an introduction to the general concepts is provided, together with a discussion on approximate analytic expressions. The second part cons

Haemophilia A and B--two years experience of genetic counselling and prenatal diagnosis

Haemophilia A. Thirty-one pregnant women, obligate or probable carriers of haemophilia A, requested prenatal diagnosis if sex determination showed the foetus to be a male. In 11 of the 31 cases the foetuses were females; in two, the genetic variant of the disease rendered prenatal diagnosis impossible; and in two, the mother aborted spontaneously. From the remaining 16 male foetuses, blood samples

Formation and Early Evolution of Planetary Systems

Planeter är mycket vanliga i vår galax. De senaste 20 åren har man upptäckt att de flesta solliknande stjärnor har planeter kretsande omkring sig. Man vet också att det finns en stor variation av exoplaneter. Runt 50\% av alla solliknande stjärnor har superjordar (planeter med en massa eller radie mellan jordens och Neptunus) kretsande tätt intill sig vilket gör solsystemet otypiskt. Man har hittaOver the past 20 years we have discovered that exoplanets are common in the Galaxy, and are far more diverse than anyone expected. Half of all Sun-like stars are accompanied by at least one super-Earth (a planet with a size between Earth and Neptune), many planets have very high eccentricities indicative of a dynamical origin, and a small fraction of stars are accompanied by hot Jupiters, whose or

Localisation of neuronal nitric oxide synthase-immunoreactivity in rat and rabbit retinas

The distribution of neuronal nitric oxide synthase (NOS) immunoreactivity was examined in rat and rabbit retinas and was compared with the distribution of nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase reactivity and vasoactive intestinal peptide (VIP) immunoreactivity. An antibody raised against a C-terminal fragment of a cloned rat cerebellar NOS was used to localise NOS immunore

Distribution of GABA immunoreactivity in kainic acid-treated rabbit retina

Ischaemic retinal cell degeneration seems to involve both NMDA and non-NMDA receptor over-stimulation. However, different retinal cell types differ largely in their susceptibility to excitatory amino acid-induced neurotoxicity. We have investigated the vulnerability of GABAergic cells in the rabbit retina to the non-NMDA receptor agonist kainic acid (KA). The distribution of GABA immunoreactivity

Release of endogenous and radioactive purines from the rabbit retina

The adenine nucleotide pool of rabbit retina was labeled by an intravitreal injection in vivo of [3H]adenosine. Practically all the radioactivity was retained in the form of adenine nucleotides. The relative proportion of [3H]adenine nucleotides was the same as that of endogenous nucleotides. Potassium depolarization (43.6 mM) in vitro caused a rapid increase in the rate of release of radioactive

Autoradiography of nucleoside uptake into the retina

A selective uptake mechanism for some nucleosides and related substances was found in retinae of light adapted rabbits and fish. After the intravitreal injection in vivo of [(3)H]adenosine, [(3)H]inosine, [(3)H]guanosine and certain related compounds, the distribution of radioactivity was studied by autoradiography. Retinae were also incubated in [(3)H]adenosine and [(3)H]inosine and then were sim

Assembly of tapasin-associated MHC class I in the absence of the transporter associated with antigen processing (TAP)

The assembly of MHC class I molecules is regulated by a multi-protein complex in the endoplasmic reticules (ER) termed the loading complex. Tapasin is suggested to be one of the molecules forming this complex on the basis of its interaction with both the transporter associated with antigen processing (TAP) and MHC class I molecules. To address whether TAP is indispensable for the processing of the

Inhibition of the transcription factors AP-1 and NF-kappaB in CD4 T cells by peroxisome proliferator-activated receptor gamma ligands

The peroxisome proliferator-activated receptor gamma (PPARgamma), a member of the nuclear hormone receptor superfamily, is essential for adipocyte differentiation and glucose homeostasis. PPARgamma has been found recently to regulate macrophage activation in response to mitogens and inflammation. Our study shows PPARgamma to be preferentially expressed in the nuclei of resting T cells and to incre

Variability in mechanical exposure within and between individuals performing a highly constrained industrial work task

Data on exposure variability is an important remedy for designing and interpreting studies of occupational ergonomics. The present study aimed at retrieving the within- and between-subjects variance of several mechanical exposure parameters in a repeated, short-cycle task. Seven experienced operators repeatedly secured joints using two types of hand-held nutrunners. The joints were placed in three