| 1. |
- Sahlin, Carin, 1953-
(författare)
-
Sleep apnea and sleep : diagnostic aspects
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Patients with sleep apnea have frequent apneas and hypopneas during sleep. Apneas can be either central or obstructive. The apnea-hypopnea index (AHI) is the mean number of apneas and hypopneas per hour of sleep. Aims: 1) To evaluate the effect of a mandibular advancement device on obstructive apneas and sleep; 2) to evaluate the influence of body position on central apnea frequency; 3) to investigate whether obstructive or central apnea is related to mortality in patients with stroke; and 4) to investigate sleep and sleeping positions in women. Methods: Subjects were investigated during whole-night sleep respiratory recordings, either polysomnography including continuous recordings of EEG, EOG, EMG, airflow, respiratory effort, ECG, pulse oximetry and body position, or simplified sleep apnea recordings without EEG, EOG and EMG. Results: The frequency of obstructive apneas, hypopneas and arousals decreased and rapid eye movement (REM) sleep increased in patients with mild, moderate and severe sleep apnea during treatment with a mandibular advancement device. Central apneas were more prevalent in the supine position compared with the non-supine position in patients with Cheyne-Stokes respiration. The mean ± SD central AHI was 41 ± 13 in the supine position and 26 ± 12 in the non-supine position, p<0.001. Stroke patients with obstructive sleep apnea ran an increased risk of death during 10 ± 0.6 years of follow-up with an adjusted hazard ratio of 1.76 (95% CI 1.05-2.95) compared with controls, independent of hypertension, age, body mass index, gender, smoking, diabetes mellitus, atrial fibrillation, Mini-Mental State Examination and Barthel-ADL. Central apnea was not related to early death. Total sleep time, sleep efficiency, rapid eye movement sleep, slow wave and time in the supine position decreased with age in women. Sleep quality in women was reduced with age, body mass index, obstructive sleep apnea, smoking, alcohol and hypertension. Conclusions: Obstructive sleep apneas and arousals are reduced and REM sleep is increased using a mandibular advancement device in patients with mild, moderate and severe sleep apnea. The frequency of central apneas and hypopneas is increased in the supine position in patients with Cheyne-Stokes respiration. Stroke patients with obstructive sleep apnea run an increased risk of early death. Central sleep apnea was not related to early death among the present patients. Normal values for sleep stages and sleeping positions are presented in a population-based sample of women. Age, body mass index, obstructive sleep apnea, smoking, alcohol and hypertension reduce sleep quality in women.
|
|
| 2. |
- Kjellander, Eva, 1965-
(författare)
-
Jag och mitt fanskap : vad musik kan betyda för människor
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation aims to find further understanding of how people with special interest in a certain artist utilise music and the fact that they are fans in their everyday lives. I have opted to study two fans included in each group selected for this study: Kiss, Status Quo and Lasse Stefanz, one male and one female fan belonging to each respective group. I have worked according to grounded theory as a method, and through an analysis of their musical life stories, I have attempted to identify why they became fans and how them being fans has affected them in their lives.Four categories, fandom as: a marker of identity, socialisation, a form of self therapy and a pseudo religion and the core category authenticity usage show the results of the study. The categories show that to a large extent it all comes down to the musical identity of these people, i.e. the identity of being a fan, and their experiences of being fans. They have been socialised into a specific genre, which has meant increased interest in a specific artist. Family, media and friends have all played a part in this socialisation. The informants have developed cultural competence as concerns their idols, although they have also gained the subcultural capital resources required in order to come across as credible fans. Various kinds of experiences offer meaning and nourish the fans. Security and stability in everyday lives are also contributing factors to them being fans and the music offers them something that they are unable to acquire from elsewhere. They have established different strategies in order to be able to be fans, one of these being legitimacy. A vital part of this legitimacy consists in them viewing the bands as authentic, i.e. important.
|
|
| 3. |
- Stenberg, Jenny, 1976-
(författare)
-
Fluid Management in Haemodialysis : Studies on current practices and new methods
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chronic fluid overload has been identified as an independent predictor of mortality in haemodialysis patients, and 30% remain fluid overloaded at dry weight. The use of bioimpedance spectroscopy (BIS) in fluid management may improve blood pressure control and cardiovascular status. However, the importance of regular and careful clinical assessment of fluid balance is repeatedly emphasised.This thesis is based on five papers and the overall aim was to investigate current practices and new methods for fluid management in haemodialysis, and to develop a management tool for dry weight determination, based on multiple complementary methods. The purpose was to contribute to reduced prevalence of fluid overload and intradialytic symptoms in haemodialysis patients, by providing the healthcare team and the patient with a tool, that facilitates communication and enables informed decision-making in dry weight determination.In the initial, cross-sectional study, clinical praxis for dry weight assessment in Sweden and Denmark was investigated. A wide variation in routines was found. Despite high access, BIS was sparsely used. Instead, nurses’ authorisation to adjust haemodialysis patients’ dry weight was associated with improved fluid status. The second study had a qualitative approach. Focus group interviews, with healthcare professionals, were carried out to achieve a deeper understanding of the factors preventing or facilitating the use of BIS. In the third study, the usefulness of a biomarker, brain natriuretic peptide (BNP), for assessing fluid status in haemodialysis patients, was investigated. An association between BNP and fluid overload was established. The between-individual variation in BNP levels was greater than the within-individual variation over time. Therefore, if BNP is to be used as a marker for fluid overload, repeated measurements are required. In the fourth study, we developed and validated a multifactorial decision aid, Recova®, that incorporates BIS in dry weight determination. Recova® is based on physiological parameters routinely measured in haemodialysis and provides guidance on when and how to respond to recognised fluid alterations. In the fifth study, the decision aid’s effect on volume status was tested in a cohort of haemodialysis patients. Implementation of Recova® had effect on fluid status symptoms, BIS-measured hydration status and NT-proBNP levels.
|
|
| 4. |
- Lindberg, Aleksandra
(författare)
-
Efficiency and Selectivity in the Chlorate Process
- 2021
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This licentiate thesis presents experimental studies concerning two parts of the electrochemical cell in the chlorate process: a cathode and an anode.Newly synthesized MnOx electrodes were investigated for the cathodic reaction, hydrogen evolution reaction (HER) in the chlorate process. In industry addition of toxic and carcinogenic chromium (VI) as sodium dichromate provides high efficiency. Here undesirable addition of sodium dichromate was avoided while high cathodic efficiency was achieved. Cathodic efficiency and selectivity towards HER, achieved by the MnOx electrodes annealed at different temperatures, were measured by means of mass spectrometry (MS). The second study investigated oxygen evolution in the chlorate process, which is an anodic side reaction. The evolution of oxygen decreases anodic efficiency and also presents a safety risk due to occurrence of HER in the undivided cell. We followed the amount of produced oxygen by two types of the electrode TiRu, similar to that industrially used, and synthesized TiRuSnSb, by means of MS. The produced oxygen amount was compared to the amount produced by Pt. To our best knowledge, this was the first study that successfully disentangles three different sources of oxygen with good time resolution. Oxygen is produced by homogenous hypochlorite decomposition, heterogeneously by different catalysts present in the electrolyte solution and anodically during the electrolysis i.e. electrochemically. Different electrode materials catalyzed hypochlorite decomposition differently and led to a different volume of oxygen produced.
|
|
