| 1. |
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| 2. |
- Berg, S, et al.
(author)
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Incidence and prognosis of meningitis due to Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis in Sweden.
- 1996
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In: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 28:3, s. 247-52
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Journal article (peer-reviewed)abstract
- The incidence, concomitant conditions and case fatality rate of Haemophilus influenzae (Hi) and pneumococcal meningitis and of invasive meningococcal infections were studied retrospectively in Sweden (population 8.4 million) for the years 1987-89, the period before vaccination against Hi type b started. A total of 1,019 cases with culture-verified infection were found. The incidence rates per 100,000 per year were 1.8 for Hi meningitis, 1.2 for pneumococcal meningitis and 1.0 for invasive meningococcal infections. The age-specific incidence was highest in the 3-23 months age group for the 3 bacterial species. Pneumococcal meningitis was common in individuals > or = 60 years and meningococcal infections in the age-group 10-24 years. A serious concomitant condition was known in 57% of all patients with pneumococcal meningitis while this was uncommon for the other organisms. The case fatality rate was 2% for Hi meningitis, 24% for pneumococcal meningitis and 10% for meningococcal infections. All 81 pneumococcal isolates which had been serotyped belonged to serotypes in the 23-valent pneumococcal vaccine. Of the meningococcal isolates, 65% belonged to serogroup B. In conclusion, the high incidence of Hib meningitis justifies general Hib vaccination. Development of a vaccine against N. meningitidis group B should have high priority. Furthermore, improved pneumococcal vaccines are needed for patients with predisposing conditions. The currently available pneumococcal polysaccharide vaccine seems to be underused.
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| 4. |
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| 5. |
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| 6. |
- Bond, C. A., et al.
(author)
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International pharmacy
- 1995
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In: Pharmacotherapy. - 0277-0008 .- 1875-9114. ; 15:5, s. 586-591
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Journal article (peer-reviewed)
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| 7. |
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| 8. |
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| 9. |
- Claesson, PM, et al.
(author)
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Interactions between a 30% charged polyelectrolyte and an anionic surfactant in bulk and at a solid-liquid interface
- 1998
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In: Journal of Physical Chemistry B. - 1520-6106 .- 1520-5207. ; 102, s. 1270-1278
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Journal article (peer-reviewed)abstract
- The association between a 30% charged cationic polyelectrolyte and an anionic surfactant, sodium dodecyl sulfate (SDS), in 10 mM 1:1 electrolyte was investigated using surface force measurements and dynamic light scattering. The polyelectrolyte employed was a random copolymer of the neutral acrylamide and cationic [3-(2-methylpropionamide)propyl]trimethylammonium chloride (AM-MAPTAC-31). Light scattering measurements show that upon progressive addition of SDS to an AM-MAPTAC-31 solution the single coil size decreases until precipitation occurs at an SDS/MAPTAC ratio of just above 0.4. At SDS/MAPTAC ratios at or above 2, redispersion of the aggregates takes place. The interfacial behavior of AM-MAPTAC-31/SDS complexes was investigated in two ways. In one set of experiments a droplet containing a mixture of SDS and AM-MAPTAC-31 was placed between the surfaces and adsorption was allowed to occur from the aqueous mixture. It was found that the range of the steric force decreased when the SDS/MAPTAC ratio was increased from 0 to 0.4, indicating adsorption in a less extended conformation due to a decreased repulsion between the polyelectrolyte segments. At a ratio of 0.6 a compact interfacial complex was formed and the measured force was attractive over a small distance regime. A further increase in SDS/MAPTAC ratio resulted in precipitation of large aggregates at the surface, and reproducible force data could not be obtained. At an even higher SDS/AM-MAPTAC ratio of 4, individual aggregates were once again adsorbed at the surface. Hence, we find a good correspondence between association in bulk and at the solid surface. In another set of experiments the polyelectrolyte was first preadsorbed to mica surfaces and then SDS was added to the polyelectrolyte-free solution surrounding the surfaces. In this way precipitation of large SDS-polyelectrolyte aggregates onto the surfaces was avoided. Addition of SDS up to a concentration of 0.1 mM hardly affected the long-range interaction but gave an increased compressed layer thickness. A further increase in SDS concentrations to 1 mM results in a dramatic increase in the range of the force, suggesting formation of strongly negatively charged polyelectrolyte-surfactant complexes.
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| 10. |
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| 11. |
- Claesson, PM, et al.
(author)
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Interactions between hydrophilic mica surfaces in triolein: Triolein surface orientation, solvation forces, and capillary condensation
- 1997
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In: Langmuir. - 0743-7463 .- 1520-5827. ; 13, s. 1682-1688
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Journal article (peer-reviewed)abstract
- Results obtained from surface force measurements using hydrophilic mica surfaces in triolein are presented. The forces were determined for different water activities in the triglyceride sample. With anhydrous triolein two oscillations in the force curve are observed. They appear at a separation of 60-50 Å and 30-20 Å. An interfacial ordering of triolein, allowing two molecular layers between the surfaces at the position of the outer oscillation and one molecular layer at the inner one is proposed. This structure at the interface is different from the triglyceride conformation suggested for the bulk system. A dramatic effect of water content on the structural forces is observed. The number and amplitude of the oscillations are dependent on the water content. The oscillations completely disappear when the triolein sample is satured with water, and the force becomes purely attractive. These data are interpreted in terms of preferential adsorption of water molecules onto the hydrophilic mica surface and in terms of a changing water adsorption with surface separation. The adhesion force between the surfaces is strongly increased when the water content is close to its saturation value. The strong adhesion is attributes to the presence of a water capillary around the contact position.
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| 12. |
- Claesson, PM, et al.
(author)
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Polyelectrolyte-surfactant association at solid surfaces
- 1996
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In: Berichte Der Bunsen-Gesellschaft. - 0005-9021. ; 100, s. 1008-1013
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Journal article (peer-reviewed)abstract
- The interferometric surface force technique has been utilized for studying the inreraction between negatively charged surfaces coated with a cationic polyelectrolyte across solutions of anionic surfactant, sodium dodecyl sulphate (SDS). The polyelectrolyte used was poly ([2-(propionyloxy)ethyl]trimethylammonium chloride), PCMA, which has one positive charge per segment. At low ionic strength the polyelectrolyte adsorbs in a flat conformation and neutralizes the negative mica surface charge. The interaction forces between the polyelectrolytecoared surfaces are dominated by a strongly attractive force at distances shorter than about 150 Å. Addition of SDS into the measuring chamber to a concentration of about 0.1 cmc changes the interaction forces dramatically. The long-range forces are now repulsive due to a recharging of the surfaces. The polyelectrolyte layer also sweüs considerably and, more surprisingly, the force versus distance profile displays clear oscillations. We interpret these oscillations as being caused by the spatial arrangement of SDS micelles stabilized by the polyelectrolyte. The oscillations in the force curve remain as the SDS concentration is increased to cmc. The interaction forces and the layer structure for the PCMA/SDS system are very different compared to those observed for weakly charged polyelectrolyte/SDS and Iysozyme/SDS systems. The differences can be rationalized by considering that los charge density polyelectrolytes and Iysozyme, a compact cationic globular protein, cannot equally efficiently stabilize SDS micelles as a flexible high charge density cationic polyelectrolyte such as PCMA .
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| 13. |
- Claesson, PM, et al.
(author)
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Polyelectrolyte-surfactant interactions at interfaces
- 1997
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In: Progress in Colloid and Polymer Science. - 0340-255X .- 1437-8027. ; 106, s. 24-33
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Journal article (peer-reviewed)abstract
- Interactions between negatively charged surfaces coated with cationic polyelectrolytes across solutions containing an anionic surfactant, sodium dodecyl sulphate (SDS) have been studied. Polyelectrolytes with charge densities between 100% and 10%, counted per monomer unit, were used. At low ionic strength the polyelectrolytes adsorb in a flat conformation to neutralize the negative mica surface charge. The higher the linear charge density of the polyelectrolyte, the thinner adsorbed layers are obtained. In no case could any desorption be detected when the polyelectrolyte containing solution was replaced with an aqueous polyelectrolyte-free solution. The presence of SDS at concentrations considerably below the critical micellar concentration, cmc, does in all cases result in a recharging and a considerable swelling of the adsorbed layer. This is due to a cooperative association of surfactants in the preadsorbed polyelectrolyte layer. In case of the 100% charged PCMA, the force versus distance profile displays clear oscillations. We interpret these oscillations as being caused by the spatial arrangement of SDS micelles stabilised by the polyelectrolyte. The oscillations in the force curve remain as the SDS concentration is increased to twice the cmc. No similar oscillations in the force distance curve are observed when the surfaces are precoated with less charged polyelectrolytes. In these cases a strong swelling of the polyelectrolyte layer is observed once the surfactant concentration reaches a critical value (well below the cmc).
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| 14. |
- Dedinaite, A, et al.
(author)
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Interactions between hydrophilic surfaces in triglyceride media - information obtained from surface force measurements
- 1997
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In: Food Hydrocolloids. - 0268-005X .- 1873-7137. ; 11, s. 7-12
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Journal article (peer-reviewed)abstract
- The application of surface force measurements for modelling the behaviour of food colloid system, in particular dispersions of hydrophilic particles in oil continuous media, is discussed. Interactions between two mica surfaces across a triglyceride, triolein, in anhydrous state and containing different amounts of dissolved water, have been investigated. The water content influences the layering of triolein molecules at the surfaces and whereby their interactions. The relation between surface force data (e.g. the magnitude of the force barrier and the adhesion force) to the properties of colloidal systems is discussed. Further, the importance of capillary condensation for particle interactions in triolein saturated with water is demonstrated.
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| 15. |
- Dedinaite, A, et al.
(author)
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Interactions between modified mica surfaces in triglyceride media
- 1998
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In: Langmuir. - 0743-7463 .- 1520-5827. ; 14, s. 5546-5554
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Journal article (peer-reviewed)abstract
- Results obtained from surface force measurements using modified nonpolar mica surfaces immersed in triolein are presented. The force vs distance curves were determined for different water activities in the interaction medium. Two oscillations with a periodicity of 20 Å were observed in the force curve measured across anhydrous triolein. The force barriers appear at separations of 45-40 and 20-30 Å. It is suggested that triolein has no clear preferential orientation of the oleic acid chains outside a nonpolar surface. This is different from outside a polar mica surface where triolein adopts conformations with the three oleic acid residues directed toward the bulk. At high water contents the triolein molecules outside nonpolar surfaces suddenly change their orientation when a high compressive force is applied. The forces acting between mica surfaces were measured in triolein solutions containing phospholipids at different water activities. It was shown that the phospholipid self-assembled onto the mica surfaces and rendered them nonpolar. The forces between such surfaces in anhydrous triolein are similar to those observed between mica hydrophobized using the Langmuir-Blodgett technique. In addition, at high water activities a weak long range repulsive force was observed. This force was interpreted as being due to weakly adsorbed phospholipid aggregates. We discuss the implications of the results for the stability and physical properties of colloidal particle dispersions in nonpolar media. Adsorption isotherms for the phospholipid from refined vegetable oil at low water activity on mica and sucrose crystals are presented. They show that the phospholipid adsorbs in a monolayer on mica. On sucrose more than monolayer coverage is observed, which we interpret in terms of a phase separation of phospholipid into crevices and cracks.
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| 16. |
- Dedinaite, A, et al.
(author)
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Interactions between modified mica surfaces in triglyceride media
- 1998
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In: LANGMUIR. - : AMER CHEMICAL SOC. - 0743-7463. ; 14:19, s. 5546-5554
-
Journal article (other academic/artistic)abstract
- Results obtained from surface force measurements using modified nonpolar mica surfaces immersed in triolein are presented. The force vs distance curves were determined for different water activities in the interaction medium. Two oscillations with a perio
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| 17. |
- Ekvall, I, et al.
(author)
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Preparation and characterization of electrochemically etched W tips for STM
- 1999
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In: MEASUREMENT SCIENCE & TECHNOLOGY. - : IOP PUBLISHING LTD. - 0957-0233. ; 10:1, s. 11-18
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Journal article (other academic/artistic)abstract
- We have investigated methods for cleaning de-etched polycrystalline tungsten tips for scanning tunnelling microscopy (STM). The cleaning methods include Ar-ion sputtering, heating, chemical treatments and Ne-ion self-sputtering. We correlate transmission
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| 18. |
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| 19. |
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| 20. |
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| 21. |
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| 22. |
- Lagerkvist, CI, et al.
(author)
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Spin rates of asteroids
- 1996
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In: EARTH MOON AND PLANETS. - : KLUWER ACADEMIC PUBL. - 0167-9295. ; 72:1-3, s. 219-223
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Journal article (peer-reviewed)abstract
- The Asteroid Photometric Catalogue was used to redetermine the rotation periods of all asteroids with data in the catalogue. The quality of the period determinations was divided into five groups. The total number of asteroids studied were 710 and 225 of t
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| 23. |
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| 24. |
- Mays, H, et al.
(author)
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Spontaneous formation of reverse vesicles with soybean phosphatidyl ethanolamine in mixture with triglyceride and some water
- 1999
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In: Langmuir. - 0743-7463 .- 1520-5827. ; 15, s. 8072-8079
-
Journal article (peer-reviewed)abstract
- Mixing the phospholipid soybean phosphatidyl ethanolamine (PE) with the triglyceride triolein and a trace amount of water leads to a spontaneous formation of isotropic aggregates. Evidence for the existence of such aggregates in pseudo-three-component systems is presented here for the first time. Dynamic light scattering and cryogenic temperature transmission electron microscopy reveal polydisperse spherical particles with radii in the range of 250-840 nm and a mean radius of the order 600 nm. From the results of both depolarized light scattering and time-resolved electro-optical birefringence (Kerr effect) the presence of aggregates with an optical anisotropy (rodlike or wormlike reverse micelles as well as particles with lamellar structure) can be excluded. The remaining possibilities are reverse vesicles and a dispersed cubic bicontinuous phase, where our results favor reverse vesicles. A necessary condition for the formation of reverse vesicles is a saturation of the PE-triolein mixture with water; at lower water content the particles are significantly smaller.
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| 25. |
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| 26. |
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| 27. |
- Svarstad, Bonnie L, et al.
(author)
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The brief medication questionnaire: A tool for screening patient adherence and barriers to adherence
- 1999
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In: Patient Education and Counseling. - 0738-3991 .- 1873-5134. ; 37:2, s. 113-124
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Journal article (peer-reviewed)abstract
- Self-report tools for monitoring adherence can be useful in identifying patients who need assistance with their medications, assessing patient concerns, and evaluating new programs. The aim of this study is to test the validity of the Brief Medication Questionnaire (BMQ), a new self-report tool for screening adherence and barriers to adherence. The tool includes a 5-item Regimen Screen that asks patients how they took each medication in the past week, a 2-item Belief Screen that asks about drug effects and bothersome features, and a 2-item Recall Screen about potential difficulties remembering. Validity was assessed in 20 patients using the Medication Events Monitoring System (MEMS). Results varied by type of non-adherence, with the Regimen and Belief Screens having 80–100% sensitivity for “repeat” non-adherence and the Recall Screen having 90% sensitivity for “sporadic” non-adherence. The BMQ appears more sensitive than existing tools and may be useful in identifying and diagnosing adherence problems.
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| 28. |
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| 29. |
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