| 1. |
- Siebenmann, C., et al.
(författare)
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Cardiac output during exercise: A comparison of four methods
- 2015
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Ingår i: Scandinavian Journal of Medicine & Science in Sports. - : Wiley. - 0905-7188. ; 25:1
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Tidskriftsartikel (refereegranskat)abstract
- Several techniques assessing cardiac output (Q) during exercise are available. The extent to which the measurements obtained from each respective technique compares to one another, however, is unclear. We quantified Q simultaneously using four methods: the Fick method with blood obtained from the right atrium (Q(Fick-M)), Innocor (inert gas rebreathing; Q(Inn)), Physioflow (impedance cardiography; Q(Phys)), and Nexfin (pulse contour analysis; Q(Pulse)) in 12 male subjects during incremental cycling exercise to exhaustion in normoxia and hypoxia (FiO2=12%). While all four methods reported a progressive increase in Q with exercise intensity, the slopes of the Q/oxygen uptake (VO2) relationship differed by up to 50% between methods in both normoxia [4.9 +/- 0.3, 3.9 +/- 0.2, 6.0 +/- 0.4, 4.8 +/- 0.2L/min per L/min (mean +/- SE) for Q(Fick-M), Q(Inn), Q(Phys) and Q(Pulse), respectively; P=0.001] and hypoxia (7.2 +/- 0.7, 4.9 +/- 0.5, 6.4 +/- 0.8 and 5.1 +/- 0.4L/min per L/min; P=0.04). In hypoxia, the increase in the Q/VO2 slope was not detected by Nexfin. In normoxia, Q increases by 5-6L/min per L/min increase in VO2, which is within the 95% confidence interval of the Q/VO2 slopes determined by the modified Fick method, Physioflow, and Nexfin apparatus while Innocor provided a lower value, potentially reflecting recirculation of the test gas into the pulmonary circulation. Thus, determination of Q during exercise depends significantly on the applied method.
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| 2. |
- Fougelberg, Julia, et al.
(författare)
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Dermoscopic Findings in Intraepidermal Carcinoma: an Interobserver Agreement Study
- 2023
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Ingår i: Dermatology Practical & Conceptual. - : Mattioli1885. - 2160-9381. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: A wide range of descriptive terms have been used for dermoscopic findings in intraepidermal carcinoma (IEC) and the clinical diagnostic accuracy of IEC can be challenging. Furthermore, dermoscopic findings in IEC have only rarely been evaluated in fair-skinned populations.Objectives: To measure the interobserver agreement between dermatologists for dermoscopic findings in IEC. Furthermore, to describe the frequency of these findings in a predominantly fair-skinned population. Methods: One hundred dermoscopic images of histopathologically verified IECs were collected. The 11 most common dermoscopic findings described in previous studies were re-defined in a new terminology in a pre-study consensus meeting. Images were assessed by eight experienced international dermoscopists. The frequency of findings and the interobserver agreement was analyzed.Results: Scales (83%), dotted/glomerular vessels (77%), pinkish-white areas (73%) and hemorrhage (46%) were the most commonly present dermoscopic findings. Pigmented structures were found in 32% and shiny white structures (follicular or stromal) in 54% of the IEC. Vascular structures (vessels and/or hemorrhage) could be seen in 89% of the lesions. Overall, the interobserver agreement for the respective dermoscopic findings was poor to moderate, with the highest kappa values noted for scales (0.55) and hemorrhage (0.54) and the lowest for pinkish-white areas (0.015).Conclusion: Our results confirm those of previous studies on dermoscopy in IEC, including the frequency of pigmented structures despite the fair-skinned population. The interobserver agreement was relatively low. The proposed new terminology and our findings can hopefully serve as a guideline for researchers, teachers and students on how to identify IEC.
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| 3. |
- Kunz, Susanna, V, et al.
(författare)
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A simplified approach to thermally activated delayed fluorescence (TADF) bipolar host polymers
- 2022
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Ingår i: Polymer Chemistry. - : Royal Society of Chemistry. - 1759-9954 .- 1759-9962. ; 13:29, s. 4241-4248
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Tidskriftsartikel (refereegranskat)abstract
- Organic Light Emitting Diodes (OLEDs) are a critical part of current consumer electronics, from mobile device displays to solid-state lighting. Thus demand for the development of industrially compatible OLED materials continues to increase. Herein, we introduce a series of solution-processible polymers incorporating a Thermally Activated Delayed Fluorescence (TADF) emitter and a host species in the side chain to finely adjust the charge transport properties. For balanced charge transport, a bipolar host polymer based on carbazole and alpha-carboline was investigated in addition to the commonly employed unipolar host mCP and an electron transporting version thereof. We demonstrate that the combination of unipolar co-hosts on one polymer chain can generate, with less synthetic effort, the same optoelectronic properties as a polymer carrying the corresponding bipolar host molecule as a pendant.
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| 4. |
- Shiell, Martha M, et al.
(författare)
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Eye-movement patterns of hearing-impaired listeners measure comprehension of a multitalker conversation
- 2021
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Ingår i: Journal of the Acoustical Society of America. - : American Institute of Physics (AIP). - 0001-4966 .- 1520-8524. ; 149:4, s. A77-A77
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Tidskriftsartikel (refereegranskat)abstract
- The ability to understand speech in complex listening environments reflects an interaction of cognitive and sensory capacities that are difficult to capture with behavioural tests. The study of natural listening behaviours may lead to the development of new metrics that better reflect real-life communication abilities. To this end, we investigated the relationship between speech comprehension and eye-movements among hearing-impaired people in a challenging listening situation. While previous research has investigated the effect of background noise on listeners’ gaze patterns with single talkers, the effect of noise in multitalker conversations remains unknown. We tracked eye-movements of seven aided hearing-impaired adults while they viewed video recordings of two life-sized talkers engaged in an unscripted dialogue. Hearing loss ranged from moderate to severe. We used multiple-choice questions to measure participants’ comprehension of the conversation in multitalker babble noise at three different signal-to-noise ratios. All participants made saccades between the two talkers more frequently than the talkers’ conversational turns. This measure tended to correlate positively with participants’ comprehension scores, but the effect was significant in only one signal-to-noise ratio condition. Post-hoc investigation suggests that intertalker saccade rate is driven by an interaction of hearing ability and conversational turn-taking events, which will be further discussed.
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| 5. |
- Shiell, Martha M., et al.
(författare)
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Multilevel Modeling of Gaze From Listeners With Hearing Loss Following a Realistic Conversation
- 2023
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Ingår i: Journal of Speech, Language and Hearing Research. - : AMER SPEECH-LANGUAGE-HEARING ASSOC. - 1092-4388 .- 1558-9102. ; 66:11, s. 4575-4589
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: There is a need for tools to study real-world communication abilities in people with hearing loss. We outline a potential method for this that analyzes gaze and use it to answer the question of when and how much listeners with hearing loss look toward a new talker in a conversation.Method: Twenty-two older adults with hearing loss followed a prerecorded two person audiovisual conversation in the presence of babble noise. We compared their eye-gaze direction to the conversation in two multilevel logistic regression (MLR) analyses. First, we split the conversation into events classified by the number of active talkers within a turn or a transition, and we tested if these predicted the listener's gaze. Second, we mapped the odds that a listener gazed toward a new talker over time during a conversation transition.Results: We found no evidence that our conversation events predicted changes in the listener's gaze, but the listener's gaze toward the new talker during a silence-transition was predicted by time: The odds of looking at the new talker increased in an s-shaped curve from at least 0.4 s before to 1 s after the onset of the new talker's speech. A comparison of models with different random effects indicated that more variance was explained by differences between individual conversation events than by differences between individual listeners.Conclusions: MLR modeling of eye-gaze during talker transitions is a promising approach to study a listener's perception of realistic conversation. Our experience provides insight to guide future research with this method.
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| 6. |
- Siebenmann, Christoph, et al.
(författare)
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Hypoxia increases exercise heart rate despite combined inhibition of beta-adrenergic and muscarinic receptors
- 2015
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Ingår i: American Journal of Physiology. Heart and Circulatory Physiology. - : American Physiological Society. - 0363-6135 .- 1522-1539. ; 308:12, s. H1540-H1546
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Tidskriftsartikel (refereegranskat)abstract
- Hypoxia increases the heart rate response to exercise, but the mechanism(s) remains unclear. We tested the hypothesis that the tachycardic effect of hypoxia persists during separate, but not combined, inhibition of beta-adrenergic and muscarinic receptors. Nine subjects performed incremental exercise to exhaustion in normoxia and hypoxia (fraction of inspired O-2 = 12%) after intravenous administration of 1) no drugs (Cont), 2) propranolol (Prop), 3) glycopyrrolate (Glyc), or 4) Prop + Glyc. HR increased with exercise in all drug conditions (P < 0.001) but was always higher at a given workload in hypoxia than normoxia (P < 0.001). Averaged over all workloads, the difference between hypoxia and normoxia was 19.8 +/- 13.8 beats/min during Cont and similar (17.2 +/- 7.7 beats/min, P = 0.95) during Prop but smaller (P < 0.001) during Glyc and Prop + Glyc (9.8 +/- 9.6 and 8.1 +/- 7.6 beats/min, respectively). Cardiac output was enhanced by hypoxia (P < 0.002) to an extent that was similar between Cont, Glyc, and Prop + Glyc (2.3 +/- 1.9, 1.7 +/- 1.8, and 2.3 +/- 1.2 l/min, respectively, P > 0.4) but larger during Prop (3.4 +/- 1.6 l/min, P = 0.004). Our results demonstrate that the tachycardic effect of hypoxia during exercise partially relies on vagal withdrawal. Conversely, sympathoexcitation either does not contribute or increases heart rate through mechanisms other than beta-adrenergic transmission. A potential candidate is beta-adrenergic transmission, which could also explain why a tachycardic effect of hypoxia persists during combined beta-adrenergic and muscarinic receptor inhibition.
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