| 1. |
- Thati, Jyothi
(author)
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Spherical Crystallization of Benzoic Acid
- 2007
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Licentiate thesis (other academic/artistic)abstract
- Spherical agglomerates of benzoic acid crystals have been successfully prepared by drowning-out crystallization in three solvent partial miscible mixtures. Benzoic acid is dissolved in ethanol, bridging liquid is added and this mixture is fed to the agitated crystallizer containing water. Fine crystals are produced by crystallization of the substance, and the crystals are agglomerated by introduction of an immiscible liquid called the bridging liquid. The concentration of solute, agitation rate, feeding rate, amount of bridging liquid and temperature are found to have a significant influence on the physico-mechanical properties of the product. The product particle characterization includes the particle size distribution, morphology and mechanical strength. Many of the solvents such as chloroform, toluene, pentane, heptane, cyclo hexane, diethyl ether and ethyl acetate were used as bridging liquids. Among the selected solvents ethyl acetate and di ethyl ether could not form the spherical agglomerates. Characteristics of the particles are changing with the bridging liquid used. Range of the operation for spherical agglomeration is very narrow and was shown that only at certain conditions the spherical agglomerates are produced. Increased amount of bridging liquid, decrease in feeding rate and temperature causes the particle size to increase. Particle morphology depends on the bridging liquid used, amount of bridging liquid and the temperature. Particles look completely spherical from the experiments where toluene is used as bridging liquid. The mechanical strength of single agglomerates has been determined by compression in a materials testing machine, using a 10N load cell. For single particle compression an approximate estimation of the true stress is presented. Compression characteristics for single agglomerates are compared with data on particle bed compression. Low elastic recovery and high compressibility of the single particles and of bed of particles reveals that the spherical agglomerates prepared in this work have a plastic behavior which is expected to be favorable for direct tabletting. Some of the stress–strain curves are J-shaped with no clear fracturing of the particles, and are well correlated by an exponential–polynomial equation.
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| 2. |
- Ekström, Magnus, et al.
(author)
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Exertional breathlessness related to medical conditions in middle-aged people: the population-based SCAPIS study of more than 25,000 men and women.
- 2024
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In: Respiratory research. - : BioMed Central (BMC). - 1465-993X .- 1465-9921. ; 25:1
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Journal article (peer-reviewed)abstract
- Breathlessness is common in the population and can be related to a range of medical conditions. We aimed to evaluate the burden of breathlessness related to different medical conditions in a middle-aged population.Cross-sectional analysis of the population-based Swedish CArdioPulmonary bioImage Study of adults aged 50-64years. Breathlessness (modified Medical Research Council [mMRC]≥2) was evaluated in relation to self-reported symptoms, stress, depression; physician-diagnosed conditions; measured body mass index (BMI), spirometry, venous haemoglobin concentration, coronary artery calcification and stenosis [computer tomography (CT) angiography], and pulmonary emphysema (high-resolution CT). For each condition, the prevalence and breathlessness population attributable fraction (PAF) were calculated, overall and by sex, smoking history, and presence/absence of self-reported cardiorespiratory disease.We included 25,948 people aged 57.5±[SD] 4.4; 51% women; 37% former and 12% current smokers; 43% overweight (BMI 25.0-29.9), 21% obese (BMI≥30); 25% with respiratory disease, 14% depression, 9% cardiac disease, and 3% anemia. Breathlessness was present in 3.7%. Medical conditions most strongly related to the breathlessness prevalence were (PAF 95%CI): overweight and obesity (59.6-66.0%), stress (31.6-76.8%), respiratory disease (20.1-37.1%), depression (17.1-26.6%), cardiac disease (6.3-12.7%), anemia (0.8-3.3%), and peripheral arterial disease (0.3-0.8%). Stress was the main factor in women and current smokers.Breathlessness mainly relates to overweight/obesity and stress and to a lesser extent to comorbidities like respiratory, depressive, and cardiac disorders among middle-aged people in a high-income setting-supporting the importance of lifestyle interventions to reduce the burden of breathlessness in the population.
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| 3. |
- Feldötö, Zsombor, 1979-
(author)
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Structures of Polyelectrolyte Multilayers and Preasorbed Mucin : The Influence of Counterions
- 2010
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Doctoral thesis (other academic/artistic)abstract
- The focus in this thesis has been to gain a fundamental understanding of how different type of salts affect preadsorbed polyelectrolytes, both natural and synthetic. The knowledge from the fundamental work is then applied on a commercial system to investigate if the efficiency can be enhanced. We built thin films using the synthetic polyelctrolytes by using layer-by layer (LbL) deposition. The formed film is commonly known as a polyelectrolyte multilayer. The LbL method allows the incorporation of proteins, polymers, polyelectrolytes with different functions and so on within the film, thus achieving multilayers with different functions. The major measuring technique used within this thesis is the quartz crystal microbalance with dissipation (QCM-D), which measures mass adsorbed on a surface including the trapped solvent and the viscoelastic properties of an adsorbed film. The QCM-D measurements were complemented with an optical technique, dual polarization interferometry (DPI), which measures the change in refractive index and thickness. From these parameters the dry mass and relative water content of the film can be calculated. The Atomic Force Microscopy (AFM) further gave information about forces acting between preadsorbed films. We investigated the effect of salt on synthetic polyelectrolyte poly(allylamine hydrochloride)/poly(sodium 4-styrenesulfonate) built with the LbL technique, thus forming polyelectrolyte multilayers. We concluded that the multilayer build-up was linear and that the internal structure of the multilayer is of a compact and rigid nature. However, the type of rinsing protocol (termination of adsorption by: salt, water and salt first followed by water) has a significant effect on the outer layer of the formed multilayer. Interestingly, the structural changes only applied when poly(allylamine hydrochloride) was at the outermost layer and the most significant when water was used. We suggest that it is only the top layer that swells due to the removal of counterions resulting in increased intrachain repulsion. We further performed two-layer model calculations with the Voight model to confirm the QCM-D results as well as a novel two layer model simulation for the DPI data in order to resolve the thickness. The model calculations were in good agreement with each other thus we concluded that only the outer layer swells for this particular multilayer system. In a related experiment we studied the adsorption of bovine submaxillary mucin (BSM), which has an important mucousal function, to different thiol modified gold surfaces as well as the effect of electrolytes (NaCl, CaCl2, LaCl3) on preadsorbed mucin to a hydrophobic thiol-modified Au surface. The salt induced an expansion at low concentrations; higher concentrations resulted in a compaction. Increasing the valence of the counter ion resultedin a compaction at low concentrations. The structural change of preadsorbed BSM was reversible for NaCl, partially reversible for CaCl2 and irreversible for LaCl3. Interestingly, the swelling of BSM could not be fully understood by using the QCM-D and thus AFM force curves of the same system were taken and the results showed that NaCl does decrease the tail length due to the effective screening of charged sites within the BSM molecule. Increasing the valence resulted in a notable compaction already at very low concentrations suggesting that the ions bind to the anionic sites on BSM. In the last work we attempted to combine the gained knowledge from the previous studies by using the LbL-buildup on an actual commercial health care application. The above-mentioned mutlilayer were used to coat polystyrene wells in order to increase the binding of immunoglobulin (IgG). The main goal was to increase the sensitivity of the conventional enzymelinked immunosorbent spot assay (ELISpot) and subsequently the modified polystyrene wells were used with the ELISpot test with human peripheral blood mononuclear cells (PBMC) to measure the cytokine response. We suggested that the main driving force for adsorption for IgG on a PAH terminated multilayer is electrostatic attraction, whereas on PSS terminated multilayer the driving force is hydrophobic. Further, we suggested that IgG does not overcharge the surface and the linearity of the multilayer build-up is not altered when IgG is incorporated within the multilayer structure. We concluded that the cytokine response (spots) on the built multilayers regardless thickness or adsorbed IgG is significantly less than the regular polyvinyldiene fluoride (PVDF) backed ELISpot wells. We suggested that due to the compact and rigid nature of the PAH/PSS multilayer structure it is unable to form the kind of three-dimensional antibody-binding support found in the PVDF membrane. PSS terminated PAH/PSS multilayer did not induce any cytokine response whereas PAH terminated did, which suggests that PSS totally covers the surface from the cells point of view.
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| 4. |
- Kåring Wagman, Anna, 1970-
(author)
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Stadens melodi : Information och reklam i Stockholms kommun 1930-1980
- 2006
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Doctoral thesis (other academic/artistic)abstract
- The Song of Stockholm investigates the information and promotion produced by the municipality of Stockholm from 1930 to 1980. It focuses on three target groups: inhabitants, companies and tourists. Important questions are: Why did the City create a self-image? What images were presented? How did the activities change over time?The information and promotion are seen as two sides of the same phenomenon: the construction of a self-image. The theoretical perspective stresses the municipality’s dependence on other actors and the way the activities were means to handle the dependency and to gain political and economic resources. They are related to the changing nature of the tasks of the municipalities (to produce service, democracy and economic efficiency), to different instructions expressed by the State, and to economical and political problems within and outside Stockholm.The images presented to tourists and companies show that it was important to achieve balance: Stockholm was described as neither too big, modern or self-confident, nor too small, old or modest. The images intended for the inhabitants changed over time: sometimes the municipality presented itself as a harsh parent, sometimes it became more humble and wanted to communicate with the citizens.The activities point at different dilemmas. The information to the inhabitants shows that it was a way to accomplish legitimacy, but that it sometimes was simplified and accused of resembling political propaganda. The promotion addressed to companies questioned the solidarity between municipalities and affected the sensitive relation to the State. The study of the tourist promotion highlights problems in the cooperation between public and private actors.So, why did Stockholm engage in the activities? Economical problems were important, especially unemployment, but also uninterested citizens, the central regional policies and a widely spread scepticism against the capital.
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| 5. |
- Lundin, Maria, 1978-
(author)
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Adsorption of biopolymers and their layer-by-layer assemblies on hydrophilic surfaces
- 2009
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Doctoral thesis (other academic/artistic)abstract
- It is widely known that surfaces play an important role in numerous biological processes and technological applications. Thus, being able to modify surface properties provides an opportunity to control many phenomena occurring at interfaces. One way of controlling surface properties is to adsorb a polymer film onto the surface, for example through layer-by-layer (LbL) deposition of polyelectrolytes. This simple but versatile technique enables various polymers, proteins, colloidal particles etc. to be incorporated into the film, resulting in a multifunctional coating. Due to recent legislations and a consumer demand for more environmentally friendly products, we have chosen to use natural polymers (biopolymers) from renewable resources. The focus of this thesis has been on the adsorption of biopolymers and their layer-by-layer formation at solid-liquid interfaces; these processes have been studied by a wide range of techniques. The main method was the quartz crystal microbalance with dissipation monitoring (QCM-D), which measures the adsorbed mass, including trapped solvent and the viscoelastic properties of an adsorbed film. This technique was often complemented with an optical method, such as ellipsometry or dual polarization interferometry (DPI), which provided information about the “dry” polymer or protein adsorbed mass. From this combination, the solvent content and density of the layers was evaluated. In addition, the surface force apparatus (SFA), X-ray photoelectron spectroscopy (XPS), total internal reflection fluorescence (TIRF), and fluorescence resonance energy transfer (FRET) were utilized, providing further information about the film structure, chemical composition, and polymer inter-layer diffusion. Adsorption studies of the glycoprotein mucin, which has a key role in the mucousal function, showed that despite the net negative charge of mucin, it adsorbed on negatively charged substrates. The adsorbed layer was highly hydrated and the segment density on the substrate was low. We showed the importance of characterizing the mucin used, since differences in purity, such as the presence of albumin, gave rise to different adsorption behaviours in terms of both adsorbed amount and structure. The adsorbed mucin layer was to a large extent desorbed upon exposure to the anionic surfactant sodium dodecyl sulfate (SDS). In order to prevent desorption, we demonstrated that a protective layer of the cationic polysaccharide chitosan could be adsorbed onto the mucin layer and that the mucin-chitosan complexes resisted the desorption normally induced by association with SDS. Moreover, the association between chitosan and SDS was examined at the solid-liquid interface, in the bulk, and at the air-water interface. In all these environments chitosan-SDS complexes were formed and a net charge reversal of the complexes from positive to negative was observed when the concentration of SDS was increased. Furthermore, the LbL deposition method could be used to form a multilayer-like film by alternate adsorption of mucin and chitosan on silica substrates. The LbL technique was also applied to two proteins, lysozyme and β-casein with the aim of building a multilayer film consisting entirely of proteins. These proteins formed complexes at the solid-liquid interface, resulting in a proteinaceous layer, but the build-up was highly irregular with an increase in adsorbed amount per protein deposition cycle that was far less than a monolayer.Continuing with chitosan, known to have antibacterial properties we assembled multilayers with an anti-adhesive biopolymer, heparin, to evaluate the potential of this system as a coating for medical implants. Multilayers were assembled under various solution deposition conditions and the film structure and dynamics were studied in detail. The chitosan-heparin film was highly hydrated, in the range 60-80 wt-% depending on the deposition conditions. The adsorbed amount and thickness of the film increased exponential-like with the number of deposition steps, which was explained by inter-diffusion of chitosan molecules in the film during the build-up. In a novel approach, we used the distant dependent FRET technique to prove the inter-layer diffusion of fluorescent-labelled chitosan molecules within the film. The diffusion coefficient was insignificantly dependent on the deposition pH and ionic strength, and hence on the film structure. With the use of a pH sensitive dye buried under seven chitosan-heparin bilayers, we showed that the dye remained highly sensitive to the charge of the outermost layer. From complementary QCM-D data, we suggested that an increase in the energy dissipation does not necessarily indicate that the layer structure becomes less rigid.
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| 6. |
- Molin, Ylva, 1981-
(author)
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Arsenic Influences Virus Replication in Experimental Coxsackievirus B3 Infection
- 2010
-
Doctoral thesis (other academic/artistic)abstract
- Trace elements are essential for the host defence against infections, and during common infections, the balance of trace elements is changed in serum and tissues. Supplementation with selenium (Se), an essential trace element, is known to decrease the severity of coxsackievirus B3 (CVB3) infection in mice. Even the non-essential trace element arsenic (As) seems to influence the replication of some viruses. During the course of an acute CVB3 infection in mice, Se concentrations decreased in most tissues and were negatively correlated to viral load in our study. However, As concomitantly decreased in most tissues. As has previously been shown to interfere with the balance of essential trace elements. However, in the present study As supplementation in healthy mice resulted in minor effects on seven studied trace elements in serum and tissues. The effects of As supplementation were more pronounced in CVB3-infected mice, with an increase in As, but a decrease in Se in most tissues when compared with non-infected mice. As supplementation during CVB3 infection in mice decreased viral RNA concentrations in the brain (97%) and pancreas (75%), two of the target organs of this infection. In vitro experiments indicate that As caused an impaired virion assembly or release. In vivo, infection-induced expression of the host defence-associated genes nuclear factor κB (NFκB) and interferon γ (IFN-γ) were unaffected by As supplementation, except for an earlier increase in IFN-γ in the brain. In conclusion, a clinically relevant dose of As decreased the replication of CVB3 in vitro and in vivo. This antiviral effect in vivo was not related to changes in specific trace elements or in the host’s immune-mediated defence. Although the mechanism underlying the observed effect on viral replication remains to be further elucidated, As seems to be an intriguing trace element to study in the pursuit of new antiviral drugs.
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| 7. |
- Petrusenko, Nadezda, 1977-
(author)
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Creating the Revolutionary Heroines : The Case of Female Terrorists of the PSR (Russia, Beginning of the 20th Century)
- 2017
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Doctoral thesis (other academic/artistic)abstract
- Representing revolutionary terrorists as heroes and martyrs was a typical feature of the mythology of the Russian revolutionary underground at the beginning of the 20th century. This mythology described Underground Russia, the world of the revolutionaries, as an ideal country inhabited by ideal people. The purpose of that epos was to represent the revolutionary struggle, and individual revolutionaries in such a way that they would gain sympathy from the wider public and become role models for other revolutionary fighters. Sympathetic representations of women who committed political violence seem to be especially shocking in the context of Russia at the beginning of the twentieth century, since female violent behavior contradicted the existing gender order.Employing theoretical perspectives of Critical Discourse Analysis, gender history and intersectionality, the dissertation analyzes the way narratives about the individual life paths of female terrorists of the Party of Socialist Revolutionaries (the PSR), the biggest socialist party in Russia at the beginning of the 20th century, were constructed in their revolutionary auto/biographies. It analyzes how the lives of women from different social and ethnic origins, of different ages, with different life paths, who happened to be united only by their participation in the political terrorism of the PSR, were recounted with the help of narratives used in the Russian revolutionary underground.The research findings demonstrate that the accounts of the lives of female PSR terrorists were constructed with the help of the dominant narrative that was formed as a conversion story. Within the framework of that narrative, the lives of individual women were adapted to the dominant discourse of heroism and martyrdom, and at the same time were contextualized within the dominant discourse on “good” femininity that existed in the Russian society, and even within the discourse on Jews as perpetual “Others” in the Russian empire in case of Jewish women. Social and ethnic backgrounds as well as individual circumstances of the terrorist women, however, transformed the dominant narrative, and thus created diversity of representations. The discursive practice of writing a revolutionary life accepted by Bolsheviks influenced the discursive practice employed in revolutionary auto/biographies of female terrorists written during the early Soviet period.
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| 8. |
- Pihl Skoog, Emma, 1984-
(author)
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Kraftkarlar och knockouts : Kraftsporter, kropp och klass i Sverige 1920–1960
- 2017
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Doctoral thesis (other academic/artistic)abstract
- The thesis analyses representations of body and class, and their wider ideological meaning, in Swedish power sports from 1920 to 1960. Boxing and weightlifting – sports dominated by manual workers – are chosen as study objects. The sources used are magazines connected to the power sports, and autobiographies by four prominent athletes. The thesis relates to different areas of previous research. One concerns the body as such, from a social and cultural history perspective, another revolves around medial and autobiographical representations in relation to sports, and a third is about the relationships between body, class and sport.In the analysis, the Bourdieusian concepts capital and hexis are added to a discussion on the ways that value is attached to the body, linked to the notions of use value and exchange value. The content analysis of the source material makes ground for an analysis of more implicit ideological aspects, e.g. using Barthes’s theory on mythology.Manual labour and working life appear as central organising themes in the source material. Boxing and weightlifting were largely regarded and designated as professions, challenging ideals of amateurism. A physically demanding manual work was depicted as natural breeding grounds where sports practitioners became skilled. This masculine ideal united people from various manual working groups (not only from the working class in its socio-economic sense) where the emphasis was put on the physical strength and ability of the athlete to work hard.The body was used in a form of class polemics, preferably against middle and upper class people. Certain aspects of strength and style of athletic performance were related to particular levels of intelligence and education. Power athletes from the manual working groups were depicted as “natural”, with associations to rural areas, not least working in the forest. The ideas of naturalness in its most derogatory sense of being close to animals and lacking civilisation, was however mostly used in connections with black athletes.Success stories were common narratives about power sports as arenas of success. They included a powerful norm that success must be cultivated, where the responsibility was put upon the athlete himself. Successful athletes from manual working groups could transform their physical capital into economic capital, which was often depicted as short-lived because of aging and individual shortcomings.A commercial consumer culture became more explicit in the 1950s, when bodybuilding had its Swedish breakthrough within weightlifting. Sports training was rationalised and largely decoupled from its associations with manual work. This led to an increased reification of the body as pure surface, which was attributed a value itself. The body became an area of consumption, a commodity with an exchange value, when decoupled from its use value as labour or tool for sporting success.As to the ideological aspects of the development, it is shown that there was a widespread individualist norm. Only the individual himself had the possibility to rise up and achieve success. The ideal of manual work was more of a moral and cultural nature, than political. Although there were some collectivist features in that rhetoric, the manual worker idealisation fundamentally carried an individualistic tendency. It is argued that this idealisation, or workerism, is a fruitful object for further analyses.
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| 9. |
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| 10. |
- Wätterbjörk, Inger, 1955-
(author)
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Couples' experiences of an extended information visit about prenatal screening : decision making and satisfaction
- 2014
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Doctoral thesis (other academic/artistic)abstract
- The overall aim of this thesis was to describe pregnant women's and partners' views and experiences on early prenatal screening with the combined test, with special focus on the two-step information model.Interviews were performed with 15 couples who had taken part in the extended information visit about prenatal screening, describing their perceptions of the information model (I) and ten couples or women of those, for a follow-up interview exploring their decision-making process (II). Seven couples, who had not taken part in the extended information visit, were interviewed describing their views and experiences about prenatal screening (III). A questionnaire was answered by 295 women and by 223 partners about their satisfaction about the decision whether or not to participate in the combined test, and their assessment of whether or not this choice had been difficult (IV).The results showed that different opinions were expressed about the offer of the extended information visit. The separate visit was welcomed by most couples (I). The decision-making process regarding whether to take part in the test or not was described by most couples as a fairly straightforward decision, while for others it was a more complex process that required a great deal of consideration (II). An apprehension of the test, by some of those who had refrained the extended information visit, was that it was an expression of society's involvement in decisions that belong to the expectant parents (III). Ninety-three percent of both women and partners considered the decision about participating in the combined tests as uncomplicated, and well over 90%, of both women and partners were satisfied with their decision (IV).The conclusions in this thesis, are that the decision whether or not to participate in the combined test is multidimensional and influenced by different views. The two-step information model helped the pregnant woman and the partner to make a decision in a fairly straightforward process or a more complex process with mixed feelings.
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