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Presence or absence of counterion specificity in the interaction of alkylammonium surfactants with alkylacrylamide gels

Patterns in the interaction of cationic surfactants with nonionic polymer gels, which were inferred from a recent study from our laboratory, are confirmed by measurements of a series of alkylammonium surfactants with different counterions with a series of alkyl acrylamide gels of increasing hydrophobicity. Two swelling patterns were observed: Either the swelling continued above the surfactant crit

Airway effects of salmeterol in healthy individuals

The long-acting beta 2-agonist salmeterol has been shown in several in vitro studies to produce non-beta-mediated relaxant effects. The aim of the present study was to investigate whether these effects have any relevance in humans in vivo. Thirteen healthy individuals were studied in a randomized, double-blind, cross-over study on five separate days. The subjects were pre-treated orally with eithe

Circadian variation in human cerebrospinal fluid production measured by magnetic resonance imaging

Recent advances in magnetic resonance imaging have made it possible to visualize and quantify flow of cerebrospinal fluid (CSF) in the brain. The net flow of CSF through the cerebral aqueduct was used to measure CSF production in six normal volunteers at different times during a 24-h period. CSF production varied greatly both intra- and interindividually. The average CSF production in each time in

Condition-Based Maintenance: Selection and Improvement of a Cost-Effective Vibration-Based Maintenance Policy for Rolling element Bearings

Popular Abstract in Swedish Moderna tillverkningsmaskiner är dyra och därför måste dess tillgänglighet och effektivitet ständigt hållas högt. Sådana resultat kan man inte åstadkomma utan tillämpning av en effektiv underhållsstrategi. Förutsättningar för att minska eller arrestera förslitnings hastighet på maskins delar och öka maskinlivslängden är stora vid användning av tillståndsövervakning, (TÖModern machinery is expensive and therefore must run at high availability and effectiveness which cannot be achieved without an effective maintenance policy. Condition monitoring, (CM), techniques can be utilised to reduce or arrest the rate of deterioration of a component so increasing operating life. The main result reported in this thesis is that the rolling element bearing’s mean effective li

Accuracy of duplex sonography before carotid endarterectomy--a comparison with angiography

OBJECTIVES: The aim of this prospective study was to contribute to the evaluation of the reliability of Duplex sonography (DS) before carotid endarterectomy (CEA). DESIGN: The study was performed prospectively in a university hospital setting. METHODS: Eighty-one consecutive patients aged 49-83 years were examined with DS and carotid angiography (CAG) before CEA. The results of the DS were judged

Efficient one-day sampling of mechanical job exposure data - A study based on upper trapezius activity in cleaners and office workers

This ergonomics exposure assessment study compared the efficiency of eight 1-day-only strategies, that is, the relationship between the number of data collected per subject and the precision of the resulting mean exposure estimate. Whole-day electromyographic recordings from the right upper trapezius muscle in 24 cleaners and 23 office workers were processed to give minute-by-minute values of gap

Phase behavior of an ionic surfactant with mixed monovalent/polymeric counterions

A "complex salt" of cetyltrimethylammonium (CTA(+)) with short (30 repeating units) polyacrylate (PA(-)) counterions has been synthesized. The phase diagrams of its aqueous mixtures with either the surfactant cetyltrimethylammonium acetate (CTAAc), or the polyelectrolyte NaPA, have been studied by visual inspection through crossed polarizers and by small-angle X-ray scattering. Both of the ternary

Relative contribution of preload and afterload to the reduction in cardiac output caused by nitric oxide synthase inhibition with L-N(G)-methylarginine hydrochloride 546C88

OBJECTIVE: The nitric oxide synthase inhibitor L-N(G)-methylarginine hydrochloride (L-NMMA HC1 546C88) causes reductions in cardiac output (CO), a potential limitation to clinical application. This drop in CO exceeds that from phenylephrine at matched systemic arterial pressure. We tested the hypothesis that the greater fall in CO attributable to L-NMMA primarily reflects a difference in venoconst

Middle and Upper Ordovician graptolites, trilobites, and biostratigraphy of Scania and Jämtland, Sweden

Graptolites and some trilobites from Middle–Upper Ordovician siliciclastic and calcareous rocks in Scania (Skåne), southern Sweden, and Jämtland, central Sweden, are described and discussed. Their stratigraphic distribution is discussed on the basis of new and old collections from outcrops and drill cores. The uppermost Middle–Upper Ordovician of Scania consists predominantly of mudstones and dark

International growth through cooperation: Brand-driven strategies, leadership, and career development in Sweden

Corporate growth is often viewed as being either internally generated or externally achieved through mergers and acquisitions (M&As). During the last decade, strategic alliances have become an increasingly popular third alternative to either internal or acquired growth. Alliances can be cheaper, more flexible, and faster than internal or M&A growth. However, they suffer from a major drawba

Ponderomotive shearing for spectral interferometry of extreme-ultraviolet pulses

We propose a novel method for completely characterizing ultrashort pulses at extreme-ultraviolet (XUV) wavelengths by adapting the technique of spectral phase interferometry for direct electric-field reconstruction to this spectral region. Two-electron wave packets are coherently produced by photoionizing atoms with two time-delayed replicas of the XUV pulse. For one of the XUV pulses, photoioniza

New technologies to replace current blood typing reagents.

Purpose of review This review summarizes recent developments in blood grouping and compatibility testing in transfusion medicine. Recent findings Identification of the molecular characteristics of the major human blood groups has provided an opportunity to develop methods for blood group phenotyping using DNA-based technology. Various studies have demonstrated the feasibility of such an approach a

Effects of inclination angle of ribs on the flow behavior in rectangular ducts

The flow behavior in rib-roughened ducts is influenced by the inclination of ribs and the effect is investigated in the present study by Particle Image Velocimetry (PIV). The local flow structures between two adjacent ribs were measured. The Reynolds number was fixed at 5800. The flow field description was based on the PIV results in planes both parallel and perpendicular to the ribbed walls at va

Reactors - Circuit Theory and Silicon Integrated Applications

This dissertation deals with reactive components in electric circuits, both as targets for a theoretical circuit analysis, and as devices implemented in silicon processes like CMOS. The frequency behavior of a general electric network is determined by the reactances (i.e., inductances and capacitances) present in the network, either as intentional parts of the design, or as process and implementa

Simulation of Phosphorus, Zinc and Cadmium Mass Flow in Dairy Farming Systems

Popular Abstract in Swedish En simuleringsmodell, FARMFLOW, utvecklades för att beräkna förråd, flöden och balanser av fosfor (P), zink (Zn) och kadmium (Cd) på mjölkgårdar. De simulerade kontinuerliga förändringarna av ämnesförråden gör det möjligt att utvärdera de långsiktiga effekterna av olika skötselstrategier. Fältdata från en svensk försöksgård, Öjebyn, användes för att parameterisera FARMFA simulation model, FARMFLOW, was developed for the calculation of phosphorus (P), zinc (Zn) and cadmium (Cd) stocks, flows and balances in different parts of a dairy farming system. The simulated continuous change in element stocks within the farming system enables evaluation of the long-term effects of management practices. The FARMFLOW model reproduces feedback mechanisms of the internal cyclin