| 1. |
- Chehrenegar, Pirooz, 1964, et al.
(författare)
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Design and characterization of a highly linear 3 GHz GaN HEMT amplifier
- 2011
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Ingår i: 2011 Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits, INMMiC 2011. Vienna, 18-19 April 2011. - 9781457706493
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Konferensbidrag (refereegranskat)abstract
- In this paper a highly linear amplifier using an in-house gallium nitride (GaN) high electron mobility transistor (HEMT) technology is presented. A 3 dB bandwidth of 2.7-3.6 GHz with a maximum gain of 18 dB was measured. The output third-order intercept point (OIP3) was measured to 39 dBm with a maximum power consumption of 2.1 W. With a reduction of power consumption to 1 W the noise figure was improved by 0.6 dB while the OIP3 was degraded 3 dB.
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| 2. |
- Svensson, Johan, 1964, et al.
(författare)
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Liver-derived IGF1 enhances the androgenic response in prostate.
- 2008
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Ingår i: The Journal of endocrinology. - 1479-6805. ; 199:3, s. 489-97
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Tidskriftsartikel (refereegranskat)abstract
- Both IGF1 and androgens are major enhancers of prostate growth and are implicated in the development of prostate hyperplasia and cancer. The aim of the present study was to investigate whether liver-derived endocrine IGF1 modulates the androgenic response in prostate. Mice with adult, liver-specific inactivation of IGF1 (LI-IGF1(-/-) mice) displayed an approximately 80% reduction in serum IGF1 levels associated with decreased prostate weight compared with control mice (anterior prostate lobe -19%, P<0.05; dorsolateral prostate (DLP) lobe -35%, P<0.01; ventral prostate (VP) lobe -47%, P<0.01). Reduced androgen receptor (Ar) mRNA and protein levels were observed in the VP lobe (-34% and -30% respectively, both P<0.05 versus control mice). Analysis of prostate morphology showed reductions in both the glandular and fibromuscular compartments of the VP and DLP lobes that were proportional to the reductions in the weights of these lobes. Immunohistochemistry revealed reduced intracellular AR immunoreactivity in the VP and DLP lobes. The non-aromatizable androgen dihydrotestosterone increased VP weight to a lesser extent in orchidectomized (ORX) LI-IGF1(-/-) mice than in ORX controls (-40%, P<0.05 versus control mice). In conclusion, deficiency of liver-derived IGF1 reduces both the glandular and fibromuscular compartments of the prostate, decreases AR expression in prostate, and reduces the stimulatory effect of androgens on VP weight. These findings may explain, at least in part, the well-known clinical association between serum IGF1 levels and conditions with abnormal prostate growth.
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| 3. |
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| 4. |
- Andersson, Jenny, 1976, et al.
(författare)
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The Volume Fraction of a Non-overlapping Germ-grain Model
- 2006
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Ingår i: Electronic Communications in Probability. - 1083-589X. ; 11, s. 78-88
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Tidskriftsartikel (refereegranskat)abstract
- We discuss the volume fraction of a model of non--overlapping convex grains. It is obtained from thinning a Poisson process where each point has a weight and is the centre of a grain, by removing any grain that is overlapped by one of larger or equal weight. In the limit as the intensity of the Poisson process tends to infinity, the model can be identified with the intact grains in the dead leaves model if the weights are independent of the grain sizes. In this case we can show that the volume fraction is at most $1/2^d$ for $d=1$ or $2$ if the shape is fixed, but the size and the orientation are random. The upper bound is achieved for centrally symmetric sets of the same size and orientation. For general $d$ we can show the upper bound, $1/2^d$, for spherical grains with two--point radius distribution. If dependence between weight and size is allowed, it is possible to achieve a volume fraction arbitrarily close to one.
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| 5. |
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| 6. |
- Andersson, Olle, 1964, et al.
(författare)
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Development and validation of a laryngopharyngeal reflux questionnaire, the Pharyngeal reflux Symptom Questionnaire
- 2010
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Ingår i: Scandinavian Journal of Gastroenterology. - 0036-5521. ; 45:2, s. 147-159
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To develop and validate the Pharyngeal Reflux Symptom Questionnaire (PRSQ), a comprehensive, disease-specific, self-administered questionnaire for laryngopharyngeal reflux (LPR) disease. MATERIAL AND METHODS: The PRSQ was developed based on empirical evidence from a literature review and expert input from physicians and patients and tested in a pilot study. In this validation study, a total of 228 patients were included and classified according to the Reflux Symptom Index (RSI) cut-off score. Patients with an RSI score > 13 were defined as abnormal, i.e. having LPR disease (n = 102), and those with a score between 0 and 13 were defined as normal controls (n = 126). Psychometric properties of the PRSQ were evaluated by exploring the factor structure and by evaluating internal consistency and item convergent and discriminant validity. Convergent and discriminant validity were determined by using the Laryngopharyngeal Reflux-Health Related Quality of Life questionnaire (LPR-HRQL), the RSI and the Short Form-36. RESULTS: The PRSQ was well accepted by the patients. Compliance was satisfactory and missing item rates were low. After item reduction, due to items not being conceptually relevant or scaling errors and/or low factor loadings, a construct was achieved with no scaling errors and high internal consistency (Cronbach's alpha 0.79-0.93). The correlations between the PRSQ and similar dimensions in the RSI and LPR-HRQL were generally strong. Discriminant validity was satisfactory as the questionnaire discriminated between patients with and without LPR disease. CONCLUSION: The PRSQ showed good psychometric properties and may become a valuable instrument for assessing LPR disease.
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| 7. |
- Andersson, Olle, 1964
(författare)
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Laryngopharyngeal reflux - development and refinement of diagnostic tools
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Laryngopharyngeal reflux (LPR), characterized by symptoms of chronic cough, hoarseness, throat clearing, globus, laryngospasm, throat pain and excessive mucus has in recent years been recognized as an extra-esophageal manifestation of gastroesophageal reflux disease (GERD). There are still many questions to be answered regarding how to diagnose the LPR disease and how to effectively select patients that may benefit from treatment. The aim of this thesis was to develop and refine diagnostics of LPR. In study I, an upper limit of normality (ULN) for hypopharyngeal acid exposure with a cut-off level of pH5 instead of the traditional pH 4 was established. Re-evaluation of ambulatory two-level 24-hour pH-registrations of 35 healthy volunteers showed an ULN of 1.5% of the pH registration. In study II we investigated the natural history of LPR and if asymptomatic pharyngeal reflux is a risk factor for the development of LPR disease. Twenty-four healthy volunteers were re-evaluated after 13 years with pH-monitoring, symptom registration and a larynx examination. Upper airway symptoms had developed in 10 of 24 (42%) subjects and pathological laryngeal findings in 9 (39%) subjects. However, the portion of subjects with pathological acid exposure at pH 4 in the hypopharynx had decreased from 42 to 13%. Study III describes the Swedish translation and adaption of the questionnaire Laryngo Pharyngeal Reflux – Health Related Quality of Life Questionnaire (LPR-HRQL). LPR-HRQL was psychometrically evaluated in a population of 228 patients with upper airway symptoms. The Swedish translated version of LPR-HRQL proved to be a statistically valid instrument to assess HRQL in patients with LPR disease. Study IV described the development and psychometric evaluation of the Pharyngeal Reflux Symptom Questionnaire (PRSQ) in the same cohort. After analysis and item-reduction it was found to be a valid and reliable instrument. The present thesis reports that the presence of asymptomatic hypopharyngeal reflux do not constitute a risk factor for future development of LPR. Although upper airway symptoms and pathological laryngeal findings seem to develop over time in a sample of healthy volunteers, there was only a weak correlation between symptoms, laryngeal findings and pH-monitoring results. The thesis also reports on normal values for hypopharyngeal reflux with a pH 5 which may potentially improve upon diagnosis since weakly acidic reflux has been implicated in mucosal damage and symptom generation. The thesis also presents validated questionnaires in Swedish for health related quality of life (LPR-HRQL) and diagnosis (PRSQ) of the LPR disease. Correctly developed and validated patient reported outcome (PRO) questionnaires have the potential to sharpen the diagnosis and to capture a treatment effect, both in research and in the clinic.
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| 8. |
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| 9. |
- Andersson, Olle, 1964, et al.
(författare)
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Validation of the Swedish translation of LPR-HRQL.
- 2010
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Ingår i: Medical science monitor. - 1234-1010. ; 16:10, s. CR480-CR487
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim of this study was to adapt the Laryngopharyngeal Reflux Health- Related Quality of Life questionnaire (LPR-HRQL) to Swedish and evaluate its psychometric properties in patients with suspected laryngopharyngeal reflux (LPR). MATERIAL/METHODS: The psychometric validation included 228 patients with suspected LPR who had previously undergone a 2-level 24-hour pH examination and who answered a mail-distributed set of questionnaires. The patients were divided into 2 comparable groups according to the Reflux Symptom Index (RSI) cut-off score: 126 patients with RSI score between 0-13 (defined as normal) and 102 patients with RSI score >13 (defined as abnormal, i.e. having LPR disease). RESULTS: LPR-HRQL was adapted to Swedish using a formal forward-backward translation method with input from expert groups (patients and physicians). Psychometric properties of the Swedish version of LPR-HRQL were evaluated by using factor analysis to explore the factor structure. Convergent and discriminant validity was determined by using the questionnaires RSI and Short Form-36 (SF-36). The psychometric tests performed fulfilled the criteria for structural integrity, validity and reliability, mostly confirming the results obtained in the original LPR-HRQL version. CONCLUSIONS: The Swedish translated version of LPR-HRQL proved to be a statistically valid instrument with which to assess HRQL in patients with LPR disease, and will be further tested in prospective studies.
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| 10. |
- Andersson, Peter, 1974, et al.
(författare)
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Inledning
- 2014
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Ingår i: Mångfaldens möjligheter. Litteratur- och språkdidaktik i Norden, red. Andersson, Holmberg, Lyngfelt, Nordenstam, Widhe. - Göteborg : Nätverket för svenska med didaktisk inriktning (SMDI).
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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