| 1. |
|
|
| 2. |
- Deans, Andrew R, et al.
(författare)
-
Finding Our Way through Phenotypes.
- 2015
-
Ingår i: PLoS Biology. - : Public Library of Science (PLoS). - 1545-7885. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Despite a large and multifaceted effort to understand the vast landscape of phenotypic data, their current form inhibits productive data analysis. The lack of a community-wide, consensus-based, human- and machine-interpretable language for describing phenotypes and their genomic and environmental contexts is perhaps the most pressing scientific bottleneck to integration across many key fields in biology, including genomics, systems biology, development, medicine, evolution, ecology, and systematics. Here we survey the current phenomics landscape, including data resources and handling, and the progress that has been made to accurately capture relevant data descriptions for phenotypes. We present an example of the kind of integration across domains that computable phenotypes would enable, and we call upon the broader biology community, publishers, and relevant funding agencies to support efforts to surmount today's data barriers and facilitate analytical reproducibility.
|
|
| 3. |
- Ehlers, Ina, 1984-, et al.
(författare)
-
Limited suppression of photorespiration by 20th century atmospheric CO2 increase in trees worldwide
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Forests are a key component of the global carbon and hydrological cycle and forest responses to environmental drivers create important feedbacks to these cycles. Photosynthetic efficiency of most forest tree species is strongly limited by photorespiration, a side reaction using O2 instead of CO2 as substrate, leading to a carbon loss for the plant. Photorespiration occurs in all trees and is reduced under elevated CO2 concentrations and increased under elevated temperature. Because the CO2 concentration of the atmosphere has increased in past decades, long-lived trees may have benefited from reduced photorespiration, but the temperature increase would have been a compensating detriment; but direct quantification of long-term changes in metabolic fluxes is lacking. Realistic forecasting of responses of trees and forests to future CO2 and temperature demands quantifying the reduction of photorespiration. In twelve tree species from five continents, we observe that photorespiration has been reduced by the CO2 increase during the past century, but for most the reduction is smaller than predicted from plant responses in CO2 alone. Comparison with data from a combined CO2 and temperature manipulation experiment shows that the reduced response can be explained by increases in leaf temperatures, which might result directly from increased air temperatures or indirectly from reduced transpirative cooling. These data suggest that global warming has already inhibited plant fertilization by increasing CO2, and that biomass increases may have been smaller than deduced from measurements of the heavy carbon isotope 13C. Observation of this centennial metabolic shift in tree physiology worldwide provides new insights into forest-climate feedbacks and can be used to improve coupled climate-vegetation models.
|
|
| 4. |
- Köhler, Elof, 1980, et al.
(författare)
-
Impact of designed asymmetries on the effective bandwidth of a backfolded piezoelectric energy harvester
- 2019
-
Ingår i: Sensors and Actuators, A: Physical. - : Elsevier BV. - 0924-4247. ; 292, s. 77-89
-
Tidskriftsartikel (refereegranskat)abstract
- For the successful realization of autonomous wireless sensors, they will have to be able to harvest energy from their surroundings. Vibrational energy harvesting is one possible power source for wireless sensors, since vibrations are abundant in many environments. In order to make vibrational energy harvesters more useful, a broad bandwidth is desirable since many vibrations are stochastic in nature. In this paper we implement asymmetry to a backfolded piezoelectric energy harvester to achieve broader effective bandwidth with maintained power output. The optimized harvester achieves a minimum of 2.75 V in the frequency range 92–162 Hz with peak power output of 1.80 mW. Asymmetry based on different lengths of the conjoined cantilevers is experimentally and numerically shown to have the largest impact on the bandwidth, compared to the impact of modified mass loadings.
|
|
| 5. |
- Staaf, Henrik, 1976, et al.
(författare)
-
Achieving increased bandwidth for 4 degree of freedom self-tuning energy harvester
- 2018
-
Ingår i: Journal of Sound and Vibration. - : Elsevier BV. - 1095-8568 .- 0022-460X. ; 420, s. 165-173
-
Tidskriftsartikel (refereegranskat)abstract
- The frequency response of a self-tuning energy harvester composed of two piezoelectric cantilevers connected by a middle beam with a sliding mass is investigated. Measurements show that incorporation of a free-sliding mass increases the bandwidth. Using an analytical model, the system is explained through close investigation of the resonance modes. Resonance mode behavior further suggests that, by breaking the symmetry of the system, even broader bandwidths are achievable.
|
|
| 6. |
- Staaf, Henrik, 1976, et al.
(författare)
-
Selftuning energy harvester by sliding weight
- 2017
-
Ingår i: Svenska Mekanikdagarna 2017, 12-13 juni, Uppsala, Sverige.
-
Konferensbidrag (refereegranskat)abstract
- This presentation reports design and measurements of a piezoelectric harvester with self-tuning for wider bandwidth and coupled piezoelectric cantilevers to maintain a high power output by extended strain distribution. The harvester is intended for powering sensors on gas turbines and has certain conditions on size, temperature and frequency
|
|
| 7. |
- Staaf, Henrik, 1976, et al.
(författare)
-
Smart design piezoelectric energy harvester with self-Tuning
- 2017
-
Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 922:1
-
Konferensbidrag (refereegranskat)abstract
- Piezoelectric energy harvesting on a gas turbine implies constraints like high temperature tolerance, size limitation and a particular range of vibrations to utilise. In order to be able to operate under these conditions a harvester needs to be space effective and efficient and to respond to the appropriate range of frequencies. We present the design, simulation and measurements for a clamped-clamped coupled piezoelectric harvester with a free-sliding weight, which adds self-Tuning for improved response within the range of vibrations from the gas turbine. We show a peak open circuit voltage of 11.7 V and a 3 dB bandwidth of 12 Hz.
|
|
| 8. |
- Staaf, Henrik, 1976, et al.
(författare)
-
Verification of Self-Tuning 4DOF Piezoelectric Energy Harvester with Enhanced Bandwidth
- 2018
-
Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 1052:To be published in Journal of Physics Conference S
-
Konferensbidrag (refereegranskat)abstract
- In this paper, we present an analytical model to predict enhanced bandwidth for a piezoelectric energy harvester with self-tuning, accomplished by a sliding mass. The model predicts that by implementing asymmetry of different piezoelectric cantilever lengths , the bandwidth can theoretically approach 60 Hz. Validation measurements demonstrate an increased 3dB bandwidth up to 21 Hz with 150 mW, by configuration 23/17 mm in open length – providing sufficient power for a ZigBee to continually transmit.
|
|
| 9. |
- Abelev, B, et al.
(författare)
-
Directed Flow of Charged Particles at Midrapidity Relative to the Spectator Plane in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV.
- 2013
-
Ingår i: Physical Review Letters. - 1079-7114. ; 111:23
-
Tidskriftsartikel (refereegranskat)abstract
- The directed flow of charged particles at midrapidity is measured in Pb-Pb collisions at sqrt[s_{NN}]=2.76 TeV relative to the collision symmetry plane defined by the spectator nucleons. A negative slope of the rapidity-odd directed flow component with approximately 3 times smaller magnitude than found at the highest RHIC energy is observed. This suggests a smaller longitudinal tilt of the initial system and disfavors the strong fireball rotation predicted for the LHC energies. The rapidity-even directed flow component is measured for the first time with spectators and found to be independent of pseudorapidity with a sign change at transverse momenta p_{T} between 1.2 and 1.7 GeV/c. Combined with the observation of a vanishing rapidity-even p_{T} shift along the spectator deflection this is strong evidence for dipolelike initial density fluctuations in the overlap zone of the nuclei. Similar trends in the rapidity-even directed flow and the estimate from two-particle correlations at midrapidity, which is larger by about a factor of 40, indicate a weak correlation between fluctuating participant and spectator symmetry planes. These observations open new possibilities for investigation of the initial conditions in heavy-ion collisions with spectator nucleons.
|
|
| 10. |
|
|
| 11. |
- Abelev, B, et al.
(författare)
-
K_{S}^{0} and Λ Production in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV.
- 2013
-
Ingår i: Physical Review Letters. - 1079-7114. ; 111:22
-
Tidskriftsartikel (refereegranskat)abstract
- The ALICE measurement of K_{S}^{0} and Λ production at midrapidity in Pb-Pb collisions at sqrt[s_{NN}]=2.76 TeV is presented. The transverse momentum (p_{T}) spectra are shown for several collision centrality intervals and in the p_{T} range from 0.4 GeV/c (0.6 GeV/c for Λ) to 12 GeV/c. The p_{T} dependence of the Λ/K_{S}^{0} ratios exhibits maxima in the vicinity of 3 GeV/c, and the positions of the maxima shift towards higher p_{T} with increasing collision centrality. The magnitude of these maxima increases by almost a factor of three between most peripheral and most central Pb-Pb collisions. This baryon excess at intermediate p_{T} is not observed in pp interactions at sqrt[s]=0.9 TeV and at sqrt[s]=7 TeV. Qualitatively, the baryon enhancement in heavy-ion collisions is expected from radial flow. However, the measured p_{T} spectra above 2 GeV/c progressively decouple from hydrodynamical-model calculations. For higher values of p_{T}, models that incorporate the influence of the medium on the fragmentation and hadronization processes describe qualitatively the p_{T} dependence of the Λ/K_{S}^{0} ratio.
|
|
| 12. |
|
|
| 13. |
- Adam, J, et al.
(författare)
-
Measurement of pion, kaon and proton production in proton-proton collisions at [Formula: see text] TeV.
- 2015
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 75:5
-
Tidskriftsartikel (refereegranskat)abstract
- The measurement of primary [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] production at mid-rapidity ([Formula: see text] 0.5) in proton-proton collisions at [Formula: see text][Formula: see text] 7 TeV performed with a large ion collider experiment at the large hadron collider (LHC) is reported. Particle identification is performed using the specific ionisation energy-loss and time-of-flight information, the ring-imaging Cherenkov technique and the kink-topology identification of weak decays of charged kaons. Transverse momentum spectra are measured from 0.1 up to 3 GeV/[Formula: see text] for pions, from 0.2 up to 6 GeV/[Formula: see text] for kaons and from 0.3 up to 6 GeV/[Formula: see text] for protons. The measured spectra and particle ratios are compared with quantum chromodynamics-inspired models, tuned to reproduce also the earlier measurements performed at the LHC. Furthermore, the integrated particle yields and ratios as well as the average transverse momenta are compared with results at lower collision energies.
|
|
| 14. |
|
|
| 15. |
- Bejhed, Johan, et al.
(författare)
-
Numerical modeling and verification of gas flow through a network of crossed narrow v-grooves
- 2006
-
Ingår i: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 0960-1317 .- 1361-6439. ; 16:10, s. 2006-2013
-
Tidskriftsartikel (refereegranskat)abstract
- The gas flow through a network of crossing thin micro-machined channels has been successfully modeled and simulated. The crossings are formed by two sets of v-grooves that intersect as two silicon wafers are bonded together. The gas is distributed from inlets via a manifold of channels to the narrow v-grooves. The narrow v-grooves could work as a particle filter. The fluidic model is derived from the Navier–Stokes equation and assumes laminar isothermal flow and incorporates small Knudsen number corrections and Poiseuille number calculations. The simulations use the finite element method. Several elements of the full crossing network model are treated separately before lumping them together: the straight v-grooves, a single crossing in an infinite set and a set of exactly four crossings along the flow path. The introduction of a crossing effectively corresponds to a virtual reduction of the length of the flow path, thereby defining a new effective length. The first and last crossings of each flow path together contribute to a pressure drop equal to that from three ordinary crossings. The derived full network model has been compared to previous experimental results on several differently shaped crossed v-groove networks. Within the experimental errors, the model corresponds to the mass flow and pressure drop measurements. The main error source is the uncertainty in v-groove width which has a profound impact on the fluidic behavior.
|
|
| 16. |
- Brothers, Soren, et al.
(författare)
-
A feedback loop links brownification and anoxia in a temperate, shallow lake
- 2014
-
Ingår i: Limnology and Oceanography. - : Wiley. - 0024-3590 .- 1939-5590. ; 59:4, s. 1388-1398
-
Tidskriftsartikel (refereegranskat)abstract
- This study examines a natural, rapid, fivefold increase in dissolved organic carbon (DOC) concentrations in a temperate shallow lake, describing the processes by which increased DOC resulted in anoxic conditions and altered existing carbon cycling pathways. High precipitation for two consecutive years led to rising water levels and the flooding of adjacent degraded peatlands. Leaching from the flooded soils provided an initial increase in DOC concentrations (from a 2010 mean of 12 ± 1 mg L−1 to a maximum concentration of 53 mg L−1 by June 2012). Increasing water levels, DOC, and phytoplankton concentrations reduced light reaching the sediment surface, eliminating most benthic primary production and promoting anoxia in the hypolimnion. From January to June 2012 there was a sudden increase in total phosphorus (from 57 µg L−1 to 216 µg L−1), DOC (from 24.6 mg L−1 to 53 mg L−1), and iron (from 0.12 mg L−1 to 1.07 mg L−1) concentrations, without any further large fluxes in water levels. We suggest that anoxic conditions at the sediment surface and flooded soils produced a dramatic release of these chemicals that exacerbated brownification and eutrophication, creating anoxic conditions that persisted roughly 6 months below a water depth of 1 m and extended periodically to the water surface. This brownification-anoxia feedback loop resulted in a near-complete loss of macroinvertebrate and fish populations, and increased surface carbon dioxide (CO2) emissions by an order of magnitude relative to previous years.
|
|
| 17. |
- Brothers, Soren M, et al.
(författare)
-
A regime shift from macrophyte to phytoplankton dominance enhances carbon burial in a shallow, eutrophic lake
- 2013
-
Ingår i: Ecosphere. - 2150-8925 .- 2150-8925. ; 4:11
-
Tidskriftsartikel (refereegranskat)abstract
- Ecological regime shifts and carbon cycling in aquatic systems have both been subject to increasing attention in recent years, yet the direct connection between these topics has remained poorly understood. A four-fold increase in sedimentation rates was observed within the past 50 years in a shallow eutrophic lake with no surface in- or outflows. This change coincided with an ecological regime shift involving the complete loss of submerged macrophytes, leading to a more turbid, phytoplankton-dominated state. To determine whether the increase in carbon (C) burial resulted from a comprehensive transformation of C cycling pathways in parallel to this regime shift, we compared the annual C balances (mass balance and ecosystem budget) of this turbid lake to a similar nearby lake with submerged macrophytes, a higher transparency, and similar nutrient concentrations. C balances indicated that roughly 80% of the C input was permanently buried in the turbid lake sediments, compared to 40% in the clearer macrophyte-dominated lake. This was due to a higher measured C burial efficiency in the turbid lake, which could be explained by lower benthic C mineralization rates. These lower mineralization rates were associated with a decrease in benthic oxygen availability coinciding with the loss of submerged macrophytes. In contrast to previous assumptions that a regime shift to phytoplankton dominance decreases lake heterotrophy by boosting whole-lake primary production, our results suggest that an equivalent net metabolic shift may also result from lower C mineralization rates in a shallow, turbid lake. The widespread occurrence of such shifts may thus fundamentally alter the role of shallow lakes in the global C cycle, away from channeling terrestrial C to the atmosphere and towards burying an increasing amount of C.
|
|
| 18. |
|
|
| 19. |
- Büttner, Barbara E, et al.
(författare)
-
Quantification of isotope-labeled and unlabeled folates and folate catabolites in urine samples by stable isotope dilution assay.
- 2013
-
Ingår i: International Journal for Vitamin and Nutrition Research. - : Hogrefe Publishing Group. - 0300-9831 .- 1664-2821. ; 83:2, s. 112-121
-
Tidskriftsartikel (refereegranskat)abstract
- Dual-label stable isotope dilution assays for the simultaneous quantification of isotopologic folates in clinical samples offer the perspective for differentiating between unlabeled folates from endogenous body pools and administered [13C5]-labeled folates from a test dose when performing bioavailability trials. In contrast to intact folates, this methodology could hitherto not be applied to the quantification of the folate catabolites, p-aminobenzoyl glutamate and p-acetamidobenzoyl glutamate. In this study, [2H4]-p-aminobenzoyl glutamate, [2H4]-p-acetamidobenzoyl glutamate, and unlabeled p-acetamidobenzoyl glutamate were synthesized. The synthesis of the [2H4]-labeled compounds started at unlabeled p-aminobenzoic acid. For the formation of p-acetamidobenzoyl glutamate, p-aminobenzoyl glutamate was acetylated. The new substances were applied successfully in stable isotope dilution assays for the simultaneous quantification of the [13C5]-labeled and unlabeled folate catabolites, p-aminobenzoyl glutamate and p-acetamidobenzoyl glutamate, along with the predominant folate vitamers in urine. The assays were based on clean-up by strong anion exchange followed by liquid chromatography-tandem mass spectrometry detection. Assay sensitivity was sufficient to detect the folate catabolites in physiologic concentrations. The limit of detection was below 0.4 and 0.3 nmol/100 g for p-aminobenzoyl glutamate isotopologues and p-acetamidobenzoyl glutamate isotopologues in urine, respectively. The successful synthesis of [2H4]-p-aminobenzoyl glutamate, [2H4]-p-acetamidobenzoyl glutamate, and unlabeled p-acetamidobenzoyl glutamate and the implementation of these substances in stable isotope dilution assays allows dual-label designs that provide a more detailed insight into human folate metabolism.
|
|
| 20. |
- Eriksson-Liebon, Magda, et al.
(författare)
-
Living with non-cardiac chest pain - An inductive qualitative interview study of spouses' perspectives
- 2024
-
Ingår i: Nursing Open. - : WILEY. - 2054-1058. ; 11:5
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: To explore spouses' experiences of living with a partner suffering from non-cardiac chest pain (NCPP). Design: An inductive qualitative study. Methods: Individual interviews (n = 10) were performed with spouses of partners having NCCP and cardiac anxiety. The analysis was performed according to Patton's guide for content analysis of qualitative data. Results: Three categories and seven subcategories were identified. First, 'a feeling of being neglected', where spouses felt ignored by healthcare professionals and excluded by their partners. Secondly, 'a tension between hope and despair' encompassed feelings of faith, support, unpreparedness for chest pain and situational frustration. Lastly, in 'a threat to ordinary life', spouses noted chest pain-induced changes impacting daily life, finances, leisure and relationships. To conclude, NCCP in partners significantly affects their spouses emotionally and practically. Spouses felt neglected and isolated, oscillating between hope and despair and experiencing faith, powerlessness and frustration. They also faced challenges in daily life and relationships.
|
|
| 21. |
- Flachskampf, Frank A, et al.
(författare)
-
Overestimation of flow velocity through leaks in mechanical valve prostheses and through small orifices by continuous-wave Doppler.
- 1997
-
Ingår i: Journal of the American Society of Echocardiography. - 0894-7317 .- 1097-6795. ; 10:9, s. 904-914
-
Tidskriftsartikel (refereegranskat)abstract
- The reliability of continuous-wave Doppler flow velocity measurements through small regurgitant lesions, such as in prosthetic leakage, has not been systematically analyzed. To evaluate the accuracy of continuous-wave Doppler in prosthetic valve leakage and small orifices in an in vitro, steady-flow model-flow velocities through the leaks of twelve intact mechanical prostheses and through six circular nozzles (area 0.5 to 20 mm2) were measured at pressure drops between 30 and 105 mm Hg. These results were compared with those predicted by the modified Bernoulli equation. Laser Doppler anemometry of flow velocities through the nozzles was also performed. Despite high correlation, there was substantial overestimation of Bernoulli predicted velocities by echo Doppler in the prosthetic leaks (mean +12.3% +/- 9.4%; range 90.3% to 143.4%). In the nozzles < or = 10 mm2, but not in the largest (20 mm2) nozzle, there was also overestimation of the Bernoulli predicted velocities (mean +6.2% +/- 2%). Laser Doppler anemometry of flow velocities through the nozzles showed slightly lower values than predicted by the Bernoulli equation. Thus, continuous-wave echo Doppler overestimates flow velocities through small orifices. This apparently is, at least in part, due to transit time effects and should be taken into account when using echo Doppler in small (< 10 mm2) orifices, such as in mild to moderate regurgitant lesions and prosthetic valve leakage.
|
|
| 22. |
- Haque, Mohammad Mazharul, 1984, et al.
(författare)
-
Thermal influence on the electrochemical behavior of a supercapacitor containing an ionic liquid electrolyte
- 2018
-
Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686. ; 263, s. 249-260
-
Tidskriftsartikel (refereegranskat)abstract
- Emerging demands on heat-durable electronics have accelerated the need for high temperature supercapacitors as well as for understanding the influence of elevated temperatures on the capacitive behavior. In this work, we present a comprehensive study of the thermal influence on a supercapacitor containing 1-ethyl-3-methylimidazolium acetate (EMIM Ac) electrolyte and activated carbon (AC) electrodes. The performance variation as a function of temperature in a range from 21 °C to 150 °C reveals that a high specific capacitance of 142 F g−1 can be achieved at 150 °C at a current density of 2 A g−1 with a rate capability of 87% at 15 A g−1 (relative to 2 A g−1). At 150 °C, equivalent series resistance (ESR) is only 0.37 Ω cm2, which is a result of improved ionic conductivity of the electrolyte at elevated temperature. The ESR value of 2.5 Ω cm2 at room temperature reflects a good compatibility between EMIM Ac and AC. In addition, a capacitance retention of more than 95% (in the end of 1000 cycles) is maintained up to120 °C followed by 85% at 150 °C. These results confirm EMIM Ac as a suitable candidate for carbon-based high temperature supercapacitors, and the observations regarding the thermal influence on performance metrics e.g. usable operation voltage could be applicable to other energy storage devices.
|
|
| 23. |
- Jansen, Willemijn J, et al.
(författare)
-
Association of Cerebral Amyloid-β Aggregation With Cognitive Functioning in Persons Without Dementia.
- 2018
-
Ingår i: JAMA psychiatry. - : American Medical Association (AMA). - 2168-6238 .- 2168-622X. ; 75:1, s. 84-95
-
Tidskriftsartikel (refereegranskat)abstract
- Cerebral amyloid-β aggregation is an early event in Alzheimer disease (AD). Understanding the association between amyloid aggregation and cognitive manifestation in persons without dementia is important for a better understanding of the course of AD and for the design of prevention trials.To investigate whether amyloid-β aggregation is associated with cognitive functioning in persons without dementia.This cross-sectional study included 2908 participants with normal cognition and 4133 with mild cognitive impairment (MCI) from 53 studies in the multicenter Amyloid Biomarker Study. Normal cognition was defined as having no cognitive concerns for which medical help was sought and scores within the normal range on cognitive tests. Mild cognitive impairment was diagnosed according to published criteria. Study inclusion began in 2013 and is ongoing. Data analysis was performed in January 2017.Global cognitive performance as assessed by the Mini-Mental State Examination (MMSE) and episodic memory performance as assessed by a verbal word learning test. Amyloid aggregation was measured with positron emission tomography or cerebrospinal fluid biomarkers and dichotomized as negative (normal) or positive (abnormal) according to study-specific cutoffs. Generalized estimating equations were used to examine the association between amyloid aggregation and low cognitive scores (MMSE score ≤27 or memory z score≤-1.28) and to assess whether this association was moderated by age, sex, educational level, or apolipoprotein E genotype.Among 2908 persons with normal cognition (mean [SD] age, 67.4 [12.8] years), amyloid positivity was associated with low memory scores after age 70 years (mean difference in amyloid positive vs negative, 4% [95% CI, 0%-7%] at 72 years and 21% [95% CI, 10%-33%] at 90 years) but was not associated with low MMSE scores (mean difference, 3% [95% CI, -1% to 6%], P=.16). Among 4133 patients with MCI (mean [SD] age, 70.2 [8.5] years), amyloid positivity was associated with low memory (mean difference, 16% [95% CI, 12%-20%], P<.001) and low MMSE (mean difference, 14% [95% CI, 12%-17%], P<.001) scores, and this association decreased with age. Low cognitive scores had limited utility for screening of amyloid positivity in persons with normal cognition and those with MCI. In persons with normal cognition, the age-related increase in low memory score paralleled the age-related increase in amyloid positivity with an intervening period of 10 to 15 years.Although low memory scores are an early marker of amyloid positivity, their value as a screening measure for early AD among persons without dementia is limited.
|
|
| 24. |
- Jansen, Willemijn J, et al.
(författare)
-
Prevalence of cerebral amyloid pathology in persons without dementia: a meta-analysis.
- 2015
-
Ingår i: JAMA. - : American Medical Association (AMA). - 1538-3598 .- 0098-7484. ; 313:19, s. 1924-38
-
Tidskriftsartikel (refereegranskat)abstract
- Cerebral amyloid-β aggregation is an early pathological event in Alzheimer disease (AD), starting decades before dementia onset. Estimates of the prevalence of amyloid pathology in persons without dementia are needed to understand the development of AD and to design prevention studies.
|
|
| 25. |
- Joshi, N., et al.
(författare)
-
MEMS Based Micro Aerial Vehicles
- 2016
-
Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 757:1
-
Konferensbidrag (refereegranskat)abstract
- Designing a flapping wing insect robot requires understanding of insect flight mechanisms, wing kinematics and aerodynamic forces. These subsystems are interconnected and their dependence on one another affects the overall performance. Additionally it requires an artificial muscle like actuator and transmission to power the wings. Several kinds of actuators and mechanisms are candidates for this application with their own strengths and weaknesses. This article provides an overview of the insect scaled flight mechanism along with discussion of various methods to achieve the Micro Aerial Vehicle (MAV) flight. Ongoing projects in Chalmers is aimed at developing a low cost and low manufacturing time MAV. The MAV design considerations and design specifications are mentioned. The wings are manufactured using 3D printed carbon fiber and are under experimental study. © Published under licence by IOP Publishing Ltd.
|
|
| 26. |
- Krishna, Akshay A. K., et al.
(författare)
-
CCS : A software framework to generate two-body potentials using Curvature Constrained Splines
- 2021
-
Ingår i: Computer Physics Communications. - : Elsevier BV. - 0010-4655 .- 1879-2944. ; 258
-
Tidskriftsartikel (refereegranskat)abstract
- We have developed an automated and efficient scheme for the fitting of data using Curvature Constrained Splines (CCS), to construct accurate two-body potentials. The approach enabled the construction of an oscillation-free, yet flexible, potential. We show that the optimization problem is convex and that it can be reduced to a standard Quadratic Programming (QP) problem. The improvements are demonstrated by the development of a two-body potential for Ne from ab initio data. We also outline possible extensions to the method.Program summaryProgram Title: CCSCPC Library link to program files: http://dx.doi.org/10.17632/7dt5nzxgbs.1Developer’s repository link: http://github.com/aksam432/CCSLicensing provisions: GPLv3Programming language: PythonExternal routines/libraries: NumPy, matplotlib, ASE, CVXOPTNature of problem: Ab initio quantum chemistry methods are often computationally very expensive. To alleviate this problem, the development of efficient empirical and semi-empirical methods is necessary. Two-body potentials are ubiquitous in empirical and semi-empirical methods.Solution method: The CCS package provides a new strategy to obtain accurate two body potentials. The potentials are described as cubic splines with curvature constraints.
|
|
| 27. |
- Köhler, Aleksandra, et al.
(författare)
-
Genome-wide association study on differentiated thyroid cancer.
- 2013
-
Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 98:10, s. 1674-1681
-
Tidskriftsartikel (refereegranskat)abstract
- Context:Genome-wide association studies (GWASs) of differentiated thyroid cancer (DTC) have identified associations with polymorphisms at 2q35 (DIRC3), 8p12 (NRG1), 9q22.33 (FOXE1) and 14q13.2 (NKX2-1). However, most of the inherited genetic risk factors of DTC remain to be discovered.Objective:Our objective was to identify additional common DTC susceptibility loci.Design:We conducted a GWAS in a high-incidence Italian population of 690 cases and 497 controls and followed up the most significant polymorphisms in two additional Italian series and in three low-incidence populations totaling 2,958 cases and 3,727 controls.Results:After excluding the most robust previously identified locus (9q22.33), the strongest association was shown by rs6759952 confirming the recently published association in DIRC3 (OR = 1.21, P = 6.4 × 10(-10), GWAS and all replications combined). Additionally, in the combined analysis of the Italian series, suggestive associations were attained with rs10238549 and rs7800391 in IMMP2L (OR = 1.27, P = 4.1 × 10(-6) and OR = 1.25, P = 5.7 × 10(-6)), rs7617304 in RARRES1 (OR =1.25, P = 4.6 × 10(-5)) and rs10781500 in SNAPC4/CARD9 (OR = 1.23, P = 3.5 × 10(-5)).Conclusions:Our findings provide further insights into the genetic and biological basis of inherited genetic susceptibility to DTC. Further studies are needed to determine the role of the identified polymorphisms in the development of DTC and their possible use in the clinical practice.
|
|
| 28. |
- Köhler, Elof, 1980, et al.
(författare)
-
Analytic modeling of a high temperature thermoelectric module for wireless sensors
- 2014
-
Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 557:1
-
Konferensbidrag (refereegranskat)abstract
- A novel high temperature thermoelectric module with thermoelectric materials never before combined in a module is currently researched. The module placement in the cooling channels of a jet engine where the cold side will be cooled by high flow cooling air (550 degrees C) and the hot side will be at the wall (800 degrees C). The aim of the project is to drastically reduce the length of the wires by replacing wired sensors with wireless sensors and power these (3-10mW) with thermoelectric harvesters. To optimize the design for the temperature range and the environment an analytic model was constructed. Using known models for this purpose was not possible for this project, as many of the models have too many assumptions, e.g. that the temperature gradient is relatively low, that thick electrodes with very low resistance can be used, that the heat transfer through the base plates are perfect or that the aim of the design is to maximize the efficiency. The analytical model in this paper is a combination of several known models with the aim to examine what materials to use in this specific environment to achieve the highest possible specific power (mW/g).
|
|
| 29. |
- Köhler, Elof, 1980, et al.
(författare)
-
Evaluation of 3D printed materials used to print WR10 horn antennas
- 2016
-
Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 757:1
-
Konferensbidrag (refereegranskat)abstract
- A WR10 waveguide horn antenna is 3D printed with three different materials. The antennas are printed on a fusion deposition modeling delta 3D printer built in house at Chalmers University of Technology. The different plastic materials used are an electrically conductive Acrylonitrile butadiene styrene (ABS), a thermally conductive polylactic acid containing 35% copper, and a tough Amphora polymer containing at least 20% carbon fiber. The antennas are all printed with a 0.25 mm nozzle and 100 μm layer thickness and the software settings are tuned to give maximum quality for each material. The three 3D printed horn antennas are compared when it comes to cost, time and material properties.
|
|
| 30. |
- Köhler, Elof, 1980, et al.
(författare)
-
Fabrication of High Temperature Thermoelectric Energy Harvesters for Wireless Sensors
- 2013
-
Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 476:1, s. Art. no. 012036-
-
Konferensbidrag (refereegranskat)abstract
- Implementing energy harvesters and wireless sensors in jet engines could simplify development and decrease costs. A thermoelectric energy harvester could be placed in the cooling channels where the temperature is between 500–900°C. This paper covers the synthesis of suitable materials and the design and fabrication of a thermoelectric module. The material choices and other design variables were done from an analytic model by numerical analysis. The module was optimized for 600–800°C with the materials Ba8Ga16Ge30 and La-doped Yb14MnSb11, both having the highest measured zT value in this region. The design goal was to be able to maintain a temperature gradient of at least 200°C with high power output. The La-doped Yb14MnSb11 was synthesized and its structure confirmed by x-ray diffraction. Measurement of properties of this material was not possible due to insufficient size of the crystals. Ba8Ga16Ge30 was synthesized and resulted in an approximated zT value of 0.83 at 700°C. Calculations based on a module with 17 couples gave a power output of 1100mW/g or 600mW/cm2 with a temperature gradient of 200K.
|
|
| 31. |
- Köhler, Elof, 1980, et al.
(författare)
-
High temperature energy harvester for wireless sensors
- 2014
-
Ingår i: Smart Materials and Structures. - : IOP Publishing. - 0964-1726 .- 1361-665X. ; 23:9, s. Art. no. 095042-
-
Tidskriftsartikel (refereegranskat)abstract
- Implementing energy harvesters and wireless sensors in jet engines will simplify development and decrease costs by reducing the need for cables. Such a device could include a small thermoelectric generator placed in the cooling channels of the jet engine where the temperature is between 500-900 degrees C. This paper covers the synthesis of suitable thermoelectric materials, design of module and proof of concept tests of a thermoelectric module. The materials and other design variables were chosen based on an analytic model and numerical analysis. The module was optimized for 600-800 degrees C with the thermoelectric materials n-type Ba8Ga16Ge30 and p-type La-doped Yb14MnSb11, both with among the highest reported figure-of-merit values, zT, for bulk materials in this region. The materials were synthesized and their structures confirmed by x-ray diffraction. Proof of concept modules containing only two thermoelectric legs were built and tested at high temperatures and under high temperature gradients. The modules were designed to survive an ambient temperature gradient of up to 200 degrees C. The first measurements at low temperature showed that the thermoelectric legs could withstand a temperature gradient of 123 degrees C and still be functional. The high temperature measurement with 800 degrees C on the hot side showed that the module remained functional at this temperature.
|
|
| 32. |
- Köhler, Elof, 1980, et al.
(författare)
-
MEMS meander harvester with tungsten proof-mass
- 2019
-
Ingår i: Journal of Physics. - : Institute of Physics Publishing.
-
Konferensbidrag (refereegranskat)abstract
- Using current battery technology the life-time of a leadless pacemaker is approximately 6-10 years, with a large portion of the pacemaker occupied by the battery. This paper investigates the possibility to use a MEMS piezoelectric harvester as a complementary energy source in leadless pacemakers. The challenge is to combine the low resonance frequency required to harvest energy from a heartbeat with the small volume of 20×4×3 mm3 available, with the corresponding harvester displacement restricted to 2 mm. Due to the displacement restriction the selected structure was a double clamped bridge in order to reduce the mass displacement, with various meander-type designs simulated to reduce resonance frequency. To further reduce resonance frequency large proof-masses of tungsten were attached by gluing. Two types of tungsten proof-masses were added to four different harvesters, 16.4 mg and 16.6 mg on sample 1 and 2 and 502 mg and 492 mg proof-mass on sample 3 and 4. The structures have 2 μm patterned PZT (deposited by sol-gel technique) and Pt metal electrodes for d31 mode harvesting. The power output measured from one of the two PZT/electrodes was 0.13 nW with 50 μm deflection at 100 k Ω optimal load resistance and 9.1 mVpp at 232 Hz.
|
|
| 33. |
- Köhler, Elof, 1980, et al.
(författare)
-
Metal-Metal Thermoelectric Harvester
- 2019
-
Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 1407:1
-
Konferensbidrag (refereegranskat)abstract
- A 3-couples proof-of-concept harvester (55×6 mm2) was assembled by spot welding 0.1 mm thick molybdenum foil and 0.15 mm thick nickel foil together. To insulate the foils from each other at the hot side a 0.1 mm thick glass fiber sheet was placed between the foils. At the cold side the harvester was insulated with 0.1 mm polyimide tape for easier handling and fabrication of the harvester. The load resistance measurement gave impedance match of approximately 0.24 Ω at 28°C, which slowly decreased to approximately 0.1 Ω as the temperature increased to 172°C. With a temperature gradient of 172°C (0-172°C) and 0.125 (±0.025) Ω load resistance, a power output was measured to 450 (±85) μW at 7.2 mV.
|
|
| 34. |
- Köhler, Elof, 1980, et al.
(författare)
-
Metal thermoelectric harvester for wireless sensors
- 2020
-
Ingår i: Smart Materials and Structures. - 0964-1726 .- 1361-665X. ; 29:8
-
Tidskriftsartikel (refereegranskat)abstract
- A metal thermoelectric energy harvester design with long metal couples was investigated for use with wireless sensors in environments where conventional thermoelectric harvesters are difficult to implement. Two thermoelectric harvesters with different designs was assembled by spot welding 110 mu m thick molybdenum foil and 150 mu m thick nickel foil together in a zigzag-pattern, one 3-couples design (55 mm length and 6 mm width) insulated with glass fiber at the hot side and polyimide tape at the cold side, and one 10-couples design (300 mm length and 3 mm width) insulated with polyimide tape across the entire length. The voltage- and power output were measured at different temperatures and load resistance with maximum power output of 588 mu W at 269 degrees C for the 3-couples harvester and 868 mu W at 241 degrees C for the 10-couples harvester. The power output after power management electronics for the 10-couples harvester measured 290 mu W at 51 mV. The harvesters were compared to a conventional semiconductor thermoelectric device coupled with a 300 mm long copper heat bridge giving a power output after power management electronics of 170 mu W at 41 mV with 226 degrees C temperature gradient of the environment.
|
|
| 35. |
- Köhler, Elof, 1980, et al.
(författare)
-
Proof of concept thermoelectric energy harvester powering wireless sensor on gas turbine
- 2016
-
Ingår i: EVI-GTI and PIWG Joint Conference on Gas Turbine Instrumentation, Berlin, Germany, 27-29 September 2016. - : Institution of Engineering and Technology. ; 2016:CP693
-
Konferensbidrag (refereegranskat)abstract
- The thermoelectric energy harvester went from simulations to synthesis of materials and fabrication of test prototypes. We also made measurements on a 1-couple module which did show that the technology is feasible, however very demanding and difficult to build at current state. We also showed with commercial modules that the high temperature energy harvester could power a Wi-Fi at current size of 1 cm2 and 0.4 g if a durable prototype with 7 couples could be manufactured successfully.
|
|
| 36. |
- Köhler, Elof, 1980, et al.
(författare)
-
Supercapacitor with increased capacitance at 200°C
- 2016
-
Ingår i: IET Conference Publications. EVI-GTI and PIWG Joint Conference on Gas Turbine Instrumentation; Berlin; Germany; 27-29 September 2016. - : Institution of Engineering and Technology. - 9781785612992 ; 2016:CP693
-
Konferensbidrag (refereegranskat)abstract
- Presents a collection a collection of slides covering the following topics: high temperature energy storage; electrode material; electrolyte; and glass fiber.
|
|
| 37. |
- Köhler, Peter, et al.
(författare)
-
Toward Reconciling Radiocarbon Production Rates With Carbon Cycle Changes of the Last 55,000 Years
- 2022
-
Ingår i: Paleoceanography and Paleoclimatology. - 2572-4517. ; 37:2
-
Tidskriftsartikel (refereegranskat)abstract
- Since it is currently not understood how changes in 14C production rate (Q), and in the carbon cycle, can be combined to explain the reconstructed atmospheric Δ14C record, we discuss possible reasons for this knowledge gap. Reviewing the literature, we exclude that changes in the content of atoms in the atmosphere, which produce cosmogenic 14C after being hit by galactic cosmic rays, might be responsible for parts of the observed differences. When combining Q with carbon cycle changes, one needs to understand the changes in the atmospheric 14C inventory, which are partially counterintuitive. For example, during the Last Glacial Maximum, Δ14C was ∼400‰ higher compared with preindustrial times, but the 14C inventory was 10% smaller. Some pronounced changes in atmospheric Δ14C do not correspond to any significant changes in the atmospheric 14C inventory, since CO2 was changing simultaneously. Using two conceptually different models (BICYCLE-SE and LSG-OGCM), we derive hypothetical Qs by forcing the models with identical atmospheric CO2 and Δ14C data. Results are compared with the most recent data-based estimates of Q derived from cosmogenic isotopes. Millennial-scale climate change connected to the bipolar seesaw is missing in the applied models, which might explain some, but probably not all, of the apparent model-data disagreement in Q. Furthermore, Q based on either data from marine sediments or ice cores contains offsets, suggesting an interpretation deficit in the current data-based approaches.
|
|
| 38. |
|
|
| 39. |
- Li, Qi, 1990, et al.
(författare)
-
Nanocomposite materials for miniaturized supercapacitors
- 2017
-
Ingår i: International Conference and Exhibition on Integration Issues of Miniaturized Systems 2017, SSI 2017, Cork, Ireland, 8-9 March 2017. ; , s. 199-205
-
Konferensbidrag (refereegranskat)
|
|
| 40. |
- Lischke, Betty, et al.
(författare)
-
Benthic carbon is inefficiently transferred in the food webs of two eutrophic shallow lakes
- 2017
-
Ingår i: Freshwater Biology. - : Wiley. - 0046-5070 .- 1365-2427. ; 62:10, s. 1693-1706
-
Tidskriftsartikel (refereegranskat)abstract
- 1. The sum of benthic autotrophic and bacterial production often exceeds the sum of pelagic autotrophic and bacterial production, and hence may contribute sub- stantially to whole-lake carbon fluxes, especially in shallow lakes. Furthermore, both benthic and pelagic autotrophic and bacterial production are highly edible and of sufficient nutritional quality for animal consumers. We thus hypothesised that pelagic and benthic transfer efficiencies (ratios of production at adjacent trophic levels) in shallow lakes should be similar. 2. We performed whole ecosystem studies in two shallow lakes (3.5 ha, mean depth 2 m), one with and one without submerged macrophytes, and quantified pelagic and benthic biomass, production and transfer efficiencies for bacteria, phytoplank- ton, epipelon, epiphyton, macrophytes, zooplankton, macrozoobenthos and fish. We expected higher transfer efficiencies in the lake with macrophytes, because these provide shelter and food for macrozoobenthos and may thus enable a more efficient conversion of basal production to consumer production. 3. In both lakes, the majority of the whole-lake autotrophic and bacterial produc- tion was provided by benthic organisms, but whole-lake primary consumer pro- duction mostly relied on pelagic autotrophic and bacterial production. Consequently, transfer efficiency of benthic autotrophic and bacterial production to macrozoobenthos production was an order of magnitude lower than the transfer efficiency of pelagic autotrophic and bacterial production to rotifer and crustacean production. Between-lake differences in transfer efficiencies were minor. 4. We discuss several aspects potentially causing the unexpectedly low benthic transfer efficiencies, such as the food quality of producers, pelagic–benthic links, oxygen concentrations in the deeper lake areas and additional unaccounted con- sumer production by pelagic and benthic protozoa and meiobenthos at interme- diate or top trophic levels. None of these processes convincingly explain the large differences between benthic and pelagic transfer efficiencies. 5. Our data indicate that shallow eutrophic lakes, even with a major share of auto- trophic and bacterial production in the benthic zone, can function as pelagic sys- tems with respect to primary consumer production. We suggest that the benthic autotrophic production was mostly transferred to benthic bacterial production, which remained in the sediments, potentially cycling internally in a similar way to what has previously been described for the microbial loop in pelagic habitats. Understanding the energetics of whole-lake food webs, including the fate of the substantial benthic bacterial production, which is either mineralised at the sedi- ment surface or permanently buried, has important implications for regional and global carbon cycling
|
|
| 41. |
- Lundgren, Johan, 1977-
(författare)
-
Behind the Screen : -Internet-Based Cognitive Behavioural Therapy to Treat Depressive Symptoms in Persons with Heart Failure
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- IntroductionThe prevalence of depressive symptoms in persons with heart failure is higher than in age- and gender-matched populations not suffering from heart failure. Heart failure in itself is associated with an unpredictable trajectory of symptoms, a poor prognosis, high mortality and morbidity, and low health-related quality of life (HrQoL). With the addition of depressive symptoms to heart failure the negative health effects increase further. Though the negative consequences of depressive symptoms in heart failure are well known, there is a knowledge gap about the course of depressive symptoms in heart failure and about how to effectively manage these symptoms. Pharmacological treatment with serotonin reuptake inhibitors has not been able to demonstrate efficacy in persons with heart failure. In a few studies, cognitive behavioural therapy (CBT) delivered face-to-face, has demonstrated effects on depressive symptoms in persons with heart failure. However, currently there are barriers in delivering face-to-face CBT as there is a lack of therapists with the required training. As a solution to this, the use of Internet-based CBT (ICBT) has been proposed. ICBT has been shown to be effective in treatment of mild and moderate depression but has not been evaluated in persons with heart failure.AimThe overall aim of this thesis was to describe depressive symptoms over time and to develop and evaluate an ICBT intervention to treat depressive symptoms in persons with heart failure.Design and MethodsThe studies in this thesis employ both quantitative (Studies I, II and III) and qualitative (Studies II and IV) research methods. The sample in Study I (n=611) were recruited in the Netherlands. The participants (n=7) in Study II were recruited via advertisements in Swedish newspapers. Studies III and IV used the same cohort of participants (Study III n=50, Study IV n=13). These participants were recruited via an invitation letter sent to all persons who had made contact with healthcare services in relation to heart failure during the previous year, at the clinics of cardiology or medicine in four hospitals in southeast Sweden.Study I had a quantitative longitudinal design. Data on depressive symptoms was collected at baseline (discharge from hospital) and after 18 months. Data on mortality and hospitalisation was collected at 18 and 36 months after discharge from hospital. Study II employed three differentBehind the Screen2patterns of design, as follows: I) The development and context adaptation of the ICBT program was based on research, literature and clinical experience and performed within a multi-professional team. II) The feasibility of the program from the perspective of limited efficacy and function was investigated with a quantitative pre-post design. III) Participants’ experience of the ICBT program was investigated with a qualitative content analysis. Data on depressive symptoms was collected pre and post intervention. The time used for support and feedback was logged during the intervention, and qualitative interviews were performed with the participants after the end of the intervention. Study III was designed as a randomised controlled trial. A nine-week ICBT program adapted to persons with heart failure and depressive symptoms was tested against an online moderated discussion forum. Data on depressive symptoms, HrQoL and cardiac anxiety was collected at baseline (before the intervention started) and after the end of the intervention (approximately 10 weeks after the start of the intervention). Study IV had a qualitative design to explore and describe participants’ experiences of ICBT. The participants were recruited from within the sample in Study III and all had experience of ICBT. Data collection occurred after the ICBT program ended and was carried out using qualitative interviews by telephone.ResultsThe mean age of the samples used in this thesis varied between 62 and 69 years of age. Concerning the symptom severity of heart failure, most persons reported New York Heart Association (NYHA) class II (40-57%) followed by NYHA class III (36-41%). Ischaemic heart disease was the most common comorbidity (36-43%). The vast majority had pharmacological treatment for their heart failure. Six percent of the persons in Study I used pharmacological antidepressants. In Studies II and III, the corresponding numbers were 43% and 18% respectively.Among persons hospitalised due to heart failure symptoms, 38% reported depressive symptoms. After 18 months, 26% reported depressive symptoms. Four different courses of depressive symptoms were identified: 1) Non-depressed 2) Remitted depressive symptoms. 3) Ongoing depressive symptoms. 4) New depressive symptoms. The highest risk for readmission to hospital and mortality was found among persons in the groups with ongoing and new depressive symptoms.A nine-week ICBT program consisting of seven modules including homework assignments on depressive symptoms for persons with heart failure was developed and tested. The RCT study (Study III) showed no significant difference in depressive symptoms between ICBT and a moderated discussion forum. Within-group analysis of depressive symptoms demonstrated a significant decrease of depressive symptoms in the ICBT group but not in the discussion forum group.The participants’ experience of ICBT was described in one theme: ICBT- an effective, but also challenging tool for self-management of health problems. This theme was constructed based on six categories: Something other than usual healthcare; Relevance and recognition; Flexible, understandable and safe; Technical problems; Improvements by live contact; Managing my life better.ConclusionAfter discharge from hospital, depressive symptoms decrease spontaneously among a large proportion of persons with heart failure, though depressive symptoms are still common in persons with heart failure that are community dwelling. Depressive symptoms in persons with heart failure are associated with increased risk of death and hospitalisation. The highest risks are found among persons with long-term ongoing depressive symptoms and those developing depressive symptoms while not hospitalised.ICBT for depressive symptoms in heart failure is feasible. An intervention with a nine-week guided self-help program with emphasis on behavioural activation and problem-solving skills appears to contribute to a decrease in depressive symptoms and improvement of HrQoL.When ICBT is delivered to persons with heart failure and depressive symptoms the participants requests that the ICBT is contextually adapted to health problems related to both heart failure and depressive symptoms. ICBT is experienced as a useful tool for self-care and something other than usual healthcare. ICBT also requires active participation by the persons receiving the intervention, something that was sometimes experienced as challenging.
|
|
| 42. |
- Lundgren, Johan Gustav, 1977-, et al.
(författare)
-
The Effect of Guided Web-Based Cognitive Behavioral Therapy on Patients With Depressive Symptoms and Heart Failure : A Pilot Randomized Controlled Trial.
- 2016
-
Ingår i: Journal of Medical Internet Research. - : JMIR Publications. - 1438-8871. ; 18:8, s. 1-13
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Depressive symptoms, and the associated coexistence of symptoms of anxiety and decreased quality of life (QoL), are common in patients with heart failure (HF). However, treatment strategies for depressive symptoms in patients with HF still remain to be established. Internet-based cognitive behavioral therapy (ICBT), as guided self-help CBT programs, has shown good effects in the treatment of depression. Until now, ICBT has not been evaluated in patients with HF with depressive symptoms.OBJECTIVE: The aims of this study were to (1) evaluate the effect of a 9-week guided ICBT program on depressive symptoms in patients with HF; (2) investigate the effect of the ICBT program on cardiac anxiety and QoL; and (3) assess factors associated with the change in depressive symptoms.METHODS: Fifty participants were randomized into 2 treatment arms: ICBT or a Web-based moderated discussion forum (DF). The Patient Health Questionnaire-9 was used to measure depressive symptoms, the Cardiac Anxiety Questionnaire (CAQ) was used to measure cardiac-related anxiety, and the Minnesota Living with Heart Failure questionnaire was used to measure QoL. Data were collected at baseline and at follow-up at the end of the 9-week intervention. Intention-to-treat analysis was used, and missing data were imputed by the Expectation-Maximization method. Between-group differences were determined by analysis of covariance with control for baseline score and regression to the mean.RESULTS: No significant difference in depressive symptoms between the ICBT and the DF group at the follow-up was found, [F(1,47)=1.63, P=.21] and Cohen´s d=0.26. Secondary within-group analysis of depressive symptoms showed that such symptoms decreased significantly in the ICBT group from baseline to the follow-up (baseline M=10.8, standard deviation [SD]=5.7 vs follow-up M=8.6, SD=4.6, t(24)=2.6, P=.02, Cohen´s d=0.43), whereas in the DF group, there was no significant change (baseline M=10.6, SD=5.0, vs follow-up M=9.8, SD=4.3, t(24)=0.93, P=.36. Cohen´s d=0.18). With regard to CAQ and QoL no significant differences were found between the groups (CAQ [d(1,47)=0.5, P=.48] and QoL [F(1,47)=2.87, P=.09]). In the ICBT group in the CAQ subscale of fear, a significant within-group decrease was shown (baseline M=1.55 vs follow-up M=1.35, P=.04). In the ICBT group, the number of logins to the Web portal correlated significantly with improvement in depressive symptoms (P=.02), whereas higher age (P=.01) and male sex (P=.048) were associated with less change in depressive symptoms. This study is underpowered because of difficulties in the recruitment of patients.CONCLUSIONS: Guided ICBT adapted for persons with HF and depressive symptoms was not statistically superior to participation in a Web-based DF. However, within the ICBT group, a statically significant improvement of depressive symptoms was detected.CLINICALTRIAL: Clinicaltrials.gov NCT01681771; https://clinicaltrials.gov/ct2/show/NCT01681771 (Archived by WebCite at http://www.webcitation.org/6ikzbcuLN).
|
|
| 43. |
- Lundgren, Johan, et al.
(författare)
-
Internet-based cognitive behavior therapy for patients with heart failure and depressive symptoms: A proof of concept study
- 2015
-
Ingår i: Patient Education and Counseling. - : Elsevier. - 0738-3991 .- 1873-5134. ; 98:8, s. 935-942
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim was (1) to describe the development of a guided internet-based CBT (ICBT) program adapted to patients with heart failure (HF) and (2) to evaluate the feasibility of the ICBT program in regard to depressive symptoms, the time used by health care providers to give feedback, and participants perceptions of the ICBT program. Method: A multi-professional team developed the program and seven HF patients with depressive symptoms were recruited to the study. The Patient Health Questionnaire-9 (PHQ-9) and the Montgomery Asberg Depression Rating-Self-rating scale (MADRS-S) were used to measure depression, and patients were interviewed about their perceptions of the program. Results: Based on research in HF and CBT, a nine-week program was developed. The median depression score decreased from baseline to the end of the study (PHQ-9: 11-8.5; MADRS-S: 25.5-16.5) and none of the depression scores worsened. Feedback from health care providers required approximately 3 h per patient. Facilitating perceptions.(e.g. freedom of time) and demanding perceptions (e.g. part of the program demanded a lot of work) were described by the patients. Conclusion: The program appears feasible and time-efficient. However, the program needs to be evaluated in a larger randomized study.
|
|
| 44. |
- Lundgren, Johan, et al.
(författare)
-
Patient Experiences of Web-Based Cognitive Behavioral Therapy for Heart Failure and Depression: Qualitative Study
- 2018
-
Ingår i: Journal of Medical Internet Research. - : JMIR PUBLICATIONS, INC. - 1438-8871. ; 20:9
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Web-based cognitive behavioral therapy (wCBT) has been proposed as a possible treatment for patients with heart failure and depressive symptoms. Depressive symptoms are common in patients with heart failure and such symptoms are known to significantly worsen their health. Although there are promising results on the effect of wCBT, there is a knowledge gap regarding how persons with chronic heart failure and depressive symptoms experience wCBT. Objective: The aim of this study was to explore and describe the experiences of participating and receiving health care through a wCBT intervention among persons with heart failure and depressive symptoms. Methods: In this qualitative, inductive, exploratory, and descriptive study, participants with experiences of a wCBT program were interviewed. The participants were included through purposeful sampling among participants previously included in a quantitative study on wCBT. Overall, 13 participants consented to take part in this study and were interviewed via telephone using an interview guide. Verbatim transcripts from the interviews were qualitatively analyzed following the recommendations discussed by Patton in Qualitative Research amp; Evaluation Methods: Integrating Theory and Practice. After coding each interview, codes were formed into categories. Results: Overall, six categories were identified during the analysis process. They were as follows: "Something other than usual health care," "Relevance and recognition," "Flexible, understandable, and safe," "Technical problems," "Improvements by real-time contact," and "Managing my life better." One central and common pattern in the findings was that participants experienced the wCBT program as something they did themselves and many participants described the program as a form of self-care. Conclusions: Persons with heart failure and depressive symptoms described wCBT as challenging. This was due to participants balancing the urge for real-time contact with perceived anonymity and not postponing the work with the program. wCBT appears to be a valuable tool for managing depressive symptoms.
|
|
| 45. |
- Lundgren, Johan, 1977-, et al.
(författare)
-
The effect of guided web-based cognitive behavioral therapy on patients with depressive symptoms and heart failure- : A randomized controlled trial.
- 2016
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Background: The aims of this study were to: (I) evaluate the effect of a nine-week guided Internet-based Cognitive Behavioral Therapy (ICBT) program on depressive symptoms (DS) in patients with HF; (II) to assess factors associated with the change in DS; and (III) to investigate the effect of the ICBT program on cardiac anxiety and QoL.Methods: Fifty participants were included and randomized into two treatment arms: ICBT or an online moderated discussion forum (DF). Data were collected at baseline and at the nine-week follow-up; the Patient Health Questionnaire- nine, (DS); the Cardiac Anxiety Questionnaire, (cardiac-related anxiety); the Minnesota Living with Heart Failure questionnaire, (QoL). Intention to treat analysis was used. Between group differences were determined by analysis of covariance.Results: In the ICBT-group (n=25), DS improved significantly (P=.02). Also cardiac anxiety in the subscale of fear decreased significantly (P=.04) between baseline and the follow up in the ICBT-group. QoL improved in the ICBT-group by 6 points in the total score and 2.4 points in the physical factor, but this was not significant (P=.09 and P=.12). In the DF-group (n=25) no significant change in the level of DS was found (P=.36). There were no significant differences in the change in DS between the DF- and the ICBT-group (P=.21), nor in cardiac related anxiety (P=.22) or in QoL (total score P=.09, physical factor P=.07). In the ICBT-group, the number of logins to the web-portal correlated significantly with improvement in DS (P=.02), whereas higher age (P=.01) and male sex (P=.048) were associated with less change in DS.Conclusions: Guided ICBT adapted for persons with HF and DS can potentially reduce DS, cardiac anxiety and increase QoL, but is not statistically superior to participation in an online DF.
|
|
| 46. |
- Mehner, Thomas, et al.
(författare)
-
Weak response of animal allochthony and production to enhanced supply of terrestrial leaf litter in nutrient-rich lakes
- 2016
-
Ingår i: Ecosystems (New York. Print). - : Springer Science and Business Media LLC. - 1432-9840 .- 1435-0629. ; 19:2, s. 311-325
-
Tidskriftsartikel (refereegranskat)abstract
- Ecosystems are generally linked via fluxes of nutrients and energy across their boundaries. For example, freshwater ecosystems in temperate regions may receive significant inputs of terrestrially derived carbon via autumnal leaf litter. This terrestrial particulate organic carbon (POC) is hypothesized to subsidize animal production in lakes, but direct evidence is still lacking. We divided two small eutrophic lakes each into two sections and added isotopically distinct maize litter to the treatment sections to simulate increased terrestrial POC inputs via leaf litter in autumn. We quantified the reliance of aquatic consumers on terrestrial resources (allochthony) in the year subsequent to POC additions by applying mixing models of stable isotopes. We also estimated lake-wide carbon (C) balances to calculate the C flow to the production of the major aquatic consumer groups: benthic macroinvertebrates, crustacean zooplankton, and fish. The sum of secondary production of crustaceans and benthic macroinvertebrates supported by terrestrial POC was higher in the treatment sections of both lakes. In contrast, total secondary and tertiary production (supported by both autochthonous and allochthonous C) was higher in the reference than in the treatment sections of both lakes. Average aquatic consumer allochthony per lake section was 27–40%, although terrestrial POC contributed less than about 10% to total organic C supply to the lakes. The production of aquatic consumers incorporated less than 5% of the total organic C supply in both lakes, indicating a low ecological efficiency. We suggest that the consumption of terrestrial POC by aquatic consumers facilitates a strong coupling with the terrestrial environment. However, the high autochthonous production and the large pool of autochthonous detritus in these nutrient-rich lakes make terrestrial POC quantitatively unimportant for the C flows within food webs.
|
|
| 47. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
-
Direct 3D printed shadow mask on Silicon
- 2016
-
Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 757:1
-
Konferensbidrag (refereegranskat)abstract
- A 3D printed shadow mask method is presented. The 3D printer prints ABS plastic directly on the wafer, thus avoiding gaps between the wafer and the shadow mask, and deformation during the process. The wafer together with the 3D printed shadow mask was sputtered with Ti and Au. The shadow mask was released by immersion in acetone. The sputtered patches through the shadow mask were compared to the opening of the 3D printed shadow mask and the design dimensions. The patterned Au patches were larger than the printed apertures, however they were smaller than the design widths. The mask was printed in 4 min, the cost is less than one euro cent, and the process is a low temperature process suitable for temperature sensitive components.
|
|
| 48. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
-
Rapid manufacturing of OSTE polymer RF-MEMS components
- 2017
-
Ingår i: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS). - : IEEE. - 1084-6999. - 9781509050789 ; , s. 901-904
-
Konferensbidrag (refereegranskat)abstract
- This paper reports the first RF-MEMS component in OSTE polymer. Three OSTE-based ridge gap resonators were fabricated by direct, high aspect ratio, photostructuring. The OSTE polymer's good adhesion to gold makes it suitable for RF-MEMS applications. The OSTE ridge gap resonators differ in how they were coated with gold. The OSTE-based devices are compared to each other as well as to Si-based, SU8-based, and CNT-based devices of equal design. The OSTE-based process was performed outside the cleanroom, and with a fast fabrication process (∼1 h). The OSTE-based device performance is on par with that of the other alternatives in terms of frequency, attenuation, and Q-factor.
|
|
| 49. |
- Reimer, Paula J., et al.
(författare)
-
The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0-55 cal kBP)
- 2020
-
Ingår i: Radiocarbon. - 0033-8222. ; 62:4, s. 725-757
-
Tidskriftsartikel (refereegranskat)abstract
- Radiocarbon (C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals.
|
|
| 50. |
- Rosolymou, E., et al.
(författare)
-
Electrodeposition of photocatalytic sn-ni matrix composite coatings embedded with doped TiO2 particles
- 2020
-
Ingår i: Coatings. - : MDPI. - 2079-6412. ; 10:8
-
Tidskriftsartikel (refereegranskat)abstract
- Direct current electrodeposited Sn-Ni/TiO2 nanostructured coatings were produced by embedding two different doped types of TiO2 particles within the alloy matrix, a commercially available doped carbon-based and doped N, S-TiO2 particles. The structural characteristics of the composite coatings have been correlated with the effect of loading, type of particles in the electrolytic bath, and the applied current density. Regardless of the type of doped particles TiO2, increasing values of applied current density resulted in a reduction of the co-deposition percentage of TiO2 particles and an increase of Tin content into the alloy matrix. The application of low current density values accompanied by a high load of particles in the bath led to the highest codeposition percentage (~3.25 wt. %) achieved in the case of embedding N, S-TiO2 particles. X-ray diffraction data demonstrated that in composite coatings the incorporation of the different types of TiO2 particles in the alloy metal matrix modified significantly the nano-crystalline structure in comparison with the pure coatings. The best photocatalytic behavior under visible irradiation was revealed for the composite coatings with the highest co-deposition percentage of doped N, S-TiO2 particles, that also exhibited enhanced wear resistance and slightly reduced microhardness compared to pure ones.
|
|
