A simple, yet safe and effective set of experiments to expose chemistry students to some of the effects that may be encountered when scaling up an organic reaction is described. The exothermic Diels–Alder reaction between maleic anhydride and cyclopentadiene was found to be ideal for our purposes and was performed in small, medium, and large scale for comparison. The observed differences of heat e

This thesis is an empirical and theoretical study of the emergence of five Swedish conditional subordinators: utan, om, hvar, ifall and bara. The first changes occur in the 13th century, and the last in the 18th century. After a theoretical introduction, in which grammaticalization as well as conditionality and conditional structures are critically discussed, five paths of change are identified. T

Background: The regulation of wall stress in the abdominal aorta (AA) of humans might be of specific interest, because the AA is the most common site for aneurysm formation in which wall stress seems to be an important pathophysiological factor. We studied the age-related changes in wall stress of the AA in healthy subjects, with the common carotid artery (CCA) as a comparison. Methods. A total of

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Conjugate addition of Meldrum's acid to 2-cyclohexenone followed by direct cyclization in PPA/acetic acid constitutes a shorter, more reproducible and higher yielding route to bicyclo[2.2.2]octane-2,6-dione than previous methods. The crude dione could be used as substrate for the baker's yeast reduction to (IR, 4S, 6S)-bicyclo[2.2.2]octane-6-ol-2-one.

BACKGROUND: Substance P is present in bronchial nerve fibres. The physiological actions of substance P are mediated via tachykinin NK(1) receptors. Immunochemical studies have demonstrated tachykinin NK(1) receptors in the rat airway epithelium. OBJECTIVE: To elucidate how epithelial tachykinin NK(1) receptors affect smooth muscle response to substance P. METHODS: Contractile response of isolated

The Internet Low Bit-rate Coder (iLBC) has emerged as a candidate for Voice over Internet Protocol (VoIP) applications. By avoiding the inter-frame coding dependencies endemic to many speech coders such as those based on Code Excited Linear Prediction, iLBC is able to achieve superior robustness to packet loss. In addition to robustness to packet loss, a VoIP codec should possess the agility to ad

Patients and Interventions. Tissue damage caused by brain retraction was evaluated utilizing intracerebral microdialysis in six patients operated on subfrontally for pituitary adenoma. The microdialysis probes (membrane length 10 mm, cut-off 20 kDalton) were placed in cerebral cortex beneath the brain retractor and perfused with Ringer solution at 0.3 mul/min. The microdialysis vials were changed

Goal: Assess host-race formation in certain moths by examining their genetic and ecological differentiation. Organisms: Stalk-feeding moths, Prodoxus quinquepunctellus, collected from sympatric populations of Yucca elata and Y rostrata in west Texas, USA. Results: Moths on the two yuccas differed significantly in mtDNA haplotype frequencies, emergence time, wing dot number, body size, and ovipos

Cartilage oligomeric matrix protein (COMP) and thrombospondin 1 (TSP1) were purified in a native form from normal bovine articular cartilage. The key step in the purification scheme was selective extraction with EDTA-containing buffer. Final separation of these two molecules was achieved by heparin affinity chromatography. Particles viewed by electron microscopy after rotary shadowing and negative

Popular Abstract in Swedish Bakgrunden till den här avhandlingen är att man vill utveckla en ny mammografimetod, som utnyttjar ultraljud. När en tunn stråle av kontinuerligt ultraljud träffar en partikel, till exempel en blodkropp, som rör sig, så uppstår en reflektion. Frekvensen av den reflekterade signalen är inte densamma som för den utsända. Signalen har fått ett så kallat Dopplerskift, där fThe motivation to study the kind of problems appearing in this thesis has been ultrasound measurements of flows, from which velocity spectra along lines can be determined. These velocity spectra can mathematically be described by a new non-linear transform, here called the Doppler Spectral Transform (DST). The Doppler spectral transform has a very rich theory, into which some steps are taken here

Supplementation of a chemically defined medium with amino acids or succinate to improve heterologous xylanase production by a prototrophic Saccharomyces cerevisiae transformant was investigated. The corresponding xylanase production during growth on ethanol in batch culture and in glucose-limited chemostat culture were quantified, as the native ADH2 promoter regulating xylanase expression was dere