| 1. |
- Papakokkinou, Eleni, et al.
(författare)
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Excess Morbidity Persists in Patients With Cushing’s Disease During Long-term Remission : A Swedish Nationwide Study
- 2020
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - Washington : Oxford University Press. - 0021-972X .- 1945-7197. ; 105:8, s. 2616-2624
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Tidskriftsartikel (refereegranskat)abstract
- Context: Whether multisystem morbidity in Cushing's disease (CD) remains elevated during long-term remission is still undetermined.Objective: To investigate comorbidities in patients with CD.Design, setting, and patients: A retrospective, nationwide study of patients with CD identified in the Swedish National Patient Register between 1987 and 2013. Individual medical records were reviewed to verify diagnosis and remission status.Main outcomes: Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated by using the Swedish general population as reference. Comorbidities were investigated during three different time periods: (i) during the 3 years before diagnosis, (ii) from diagnosis to 1 year after remission, and (iii) during long-term remission.Results: We included 502 patients with confirmed CD, of whom 419 were in remission for a median of 10 (interquartile range 4 to 21) years. SIRs (95% CI) for myocardial infarction (4.4; 1.2 to 11.4), fractures (4.9; 2.7 to 8.3), and deep vein thrombosis (13.8; 3.8 to 35.3) were increased during the 3-year period before diagnosis. From diagnosis until 1 year after remission, SIRs (95% CI were increased for thromboembolism (18.3; 7.9 to 36.0), stroke (4.9; 1.3 to 12.5), and sepsis (13.6; 3.7 to 34.8). SIRs for thromboembolism (4.9; 2.6 to 8.4), stroke (3.1; 1.8 to 4.9), and sepsis (6.0; 3.1 to 10.6) remained increased during long-term remission.Conclusion: Patients with CD have an increased incidence of stroke, thromboembolism, and sepsis even after remission, emphasizing the importance of early identification and management of risk factors for these comorbidities during long-term follow-up.
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| 2. |
- Friesen, Christopher, et al.
(författare)
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Of telomeres and temperature: measuring thermal effects on telomeres in ectothermic animals
- 2021
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Ingår i: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 31:23, s. 6069-86
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Tidskriftsartikel (refereegranskat)abstract
- Ectotherms are classic models for understanding life-history tradeoffs, including the reproduction–somatic maintenance tradeoffs that may be reflected in telomere length and their dynamics. Importantly, life-history traits of ectotherms are tightly linked to their thermal environment, with diverse or synergistic mechanistic explanations underpinning the variation. Telomere dynamics potentially provide a mechanistic link that can be used to monitor thermal effects on individuals in response to climatic perturbations. Growth rate, age and developmental stage are all affected by temperature, which interacts with telomere dynamics in complex and intriguing ways. The physiological processes underpinning telomere dynamics can be visualized and understood using thermal performance curves (TPCs). TPCs reflect the evolutionary history and the thermal environment during an individual's ontogeny. Telomere maintenance should be enhanced at or near the thermal performance optimum of a species, population and individual. The thermal sensitivity of telomere dynamics should reflect the interacting TPCs of the processes underlying them. The key processes directly underpinning telomere dynamics are mitochondrial function (reactive oxygen production), antioxidant activity, telomerase activity and telomere endcap protein status. We argue that identifying TPCs for these processes will significantly help design robust, repeatable experiments and field studies of telomere dynamics in ectotherms. Conceptually, TPCs are a valuable framework to predict and interpret taxon- and population-specific telomere dynamics across thermal regimes. The literature of thermal effects on telomeres in ectotherms is sparse and mostly limited to vertebrates, but our conclusions and recommendations are relevant across ectothermic animals.
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| 3. |
- Gschneidtner, Tina, 1985, et al.
(författare)
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Constructing a library of metal and metal-oxide nanoparticle heterodimers through colloidal assembly
- 2020
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3372 .- 2040-3364. ; 12:20, s. 11297-11305
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Tidskriftsartikel (refereegranskat)abstract
- Nanoparticle dimers composed of different metals or metal oxides, as well as different shapes and sizes, are of wide interest for applications ranging from nanoplasmonic sensing to nanooptics to biomedical engineering. Shaped nanoparticles, like triangles and nanorods, can be particularly useful in applications due to the strong localized plasmonic hot-spot that forms at the tips or corners. By placing catalytic, but traditionally weakly- or non-plasmonic nanoparticles, such as metal oxides and metals like palladium, in these hot-spots, an enhanced function for sensing, photocatalysis or optical use is predicted. Here, we present an electrostatic colloidal assembly strategy for nanoparticles, incorporating different sizes, shapes and metal or metal oxide compositions into heterodimers with smaller gaps than are achievable using nanofabrication techniques. This versatile method is demonstrated on 14 combinations, including a variety of shaped gold nanoparticles as well as palladium, iron oxide, and titanium oxide nanoparticles. These colloidal nanoparticles are stabilized with traditional surfactants, such as citrate, CTAB, PVP and oleic acid/oleylamines, indicating the wide applicability of our approach. Heterodimers of gold and palladium are further analyzed using cathodoluminescence to demonstrate the tunability of these "plasmonic molecules". Since systematically altering the absorption and emission of the plasmonic nanoparticles dimers is crucial to extending their functionality, and small gap sizes produce the strongest hot-spots, this method indicates that the electrostatic approach to heterodimer assembly can be useful in creating new nanoparticle dimers for many applications.
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| 4. |
- Hansson, Alexander, et al.
(författare)
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Sex and early-life conditions shape telomere dynamics in an ectotherm
- 2024
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Ingår i: JOURNAL OF EXPERIMENTAL BIOLOGY. - 0022-0949 .- 1477-9145. ; 227:3
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Tidskriftsartikel (refereegranskat)abstract
- Telomeres, the repetitive DNA regions that protect the ends of chromosomes, and their shortening have been linked to key life history trade-offs among growth, reproduction and lifespan. In contrast to most endotherms, many ectotherms can compensate for telomere shortening throughout life by upregulation of telomerase in somatic tissues. However, during development, marked by rapid growth and an increased sensitivity to extrinsic factors, the upregulation of telomerase may be overwhelmed, resulting in longterm impacts on telomere dynamics. In ectotherms, one extrinsic factor that may play a particularly important role in development is temperature. Here, we investigated the influence of developmental temperature and sex on early -life telomere dynamics in an oviparous ectotherm, Lacerta agilis. While there was no effect of developmental temperature on telomere length at hatching, there were subsequent effects on telomere maintenance capacity, with individuals incubated at warm temperatures exhibiting less telomere maintenance compared with cool -incubated individuals. Telomere dynamics were also sexually dimorphic, with females having longer telomeres and greater telomere maintenance compared with males. We suggest that selection drives this sexual dimorphism in telomere maintenance, in which females maximise their lifetime reproductive success by investing in traits promoting longevity such as maintenance, while males invest in short-term reproductive gains through a polygynous mating behaviour. These early -life effects, therefore, have the potential to mediate life-long changes to life histories.
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| 5. |
- Hantelius, Victor, et al.
(författare)
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Headache in patients with non-functioning pituitary adenoma before and after transsphenoidal surgery - a prospective study.
- 2024
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Ingår i: Pituitary. - 1573-7403.
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Tidskriftsartikel (refereegranskat)abstract
- To study the long-term effect of transsphenoidal surgery (TSS) on headache in patients with non-functioning pituitary adenoma (NFPA) and identify factors predicting headache relief following TSS.We evaluated headache in 101 consecutive patients with NFPA who underwent TSS from September 2015 to December 2021, preoperatively and 12-months post-surgery, by using the Migraine Disability Assessment (MIDAS) questionnaire. Health-related quality of life (QoL) was assessed using the EQ-5D visual analogue scale (EQ-VAS).Of 101 patients, 27 (27%) experienced disabling preoperative headache. Among these, the median total MIDAS score improved from 60 (interquartile range (IQR): 19-140) to 10 (IQR: 0-49) (P=0.004). Additionally, headache frequency over a 90-day period decreased from 45 (IQR: 25-83) to 6 (IQR: 3-36) days (P=0.002), and headache intensity decreased from 5 (IQR: 4-7) to 4 (IQR: 2-7) (P=0.016) at 12-months post-surgery. At 12 months post-surgery, 18 (67%) of 27 patients with preoperatively disabling headache showed clinically relevant improvement of their headache, 4 (15%) showed deterioration, and 5 (19%) remained unchanged. In patients with clinically relevant improvement of their headache, the EQ-VAS score improved from 50 (IQR: 30-7) to 80 (IQR: 65-86) (P<0.001). Of the 74 patients with no preoperative headache, 11 (15%) developed postoperative headache. We identified no clinical factors predicting postoperative headache relief.The study supports that clinically significant and long-lasting improvements of disabling headache and QoL can be achieved with TSS in a substantial number of patients with NFPA.
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| 6. |
- Kanne, Thomas, et al.
(författare)
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Epitaxial Pb on InAs nanowires for quantum devices
- 2021
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Ingår i: Nature Nanotechnology. - : Springer Science and Business Media LLC. - 1748-3387 .- 1748-3395. ; 16:7, s. 776-781
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Tidskriftsartikel (refereegranskat)abstract
- Semiconductor-superconductor hybrids are used for realizing complex quantum phenomena but are limited in the accessible magnetic field and temperature range. Now, hybrid devices made from InAs nanowires and epitaxially matched, single-crystal, atomically flat Pb films present superior characteristics, doubling the available parameter space. Semiconductor-superconductor hybrids are widely used to realize complex quantum phenomena, such as topological superconductivity and spins coupled to Cooper pairs. Accessing new, exotic regimes at high magnetic fields and increasing operating temperatures beyond the state-of-the-art requires new, epitaxially matched semiconductor-superconductor materials. One challenge is the generation of favourable conditions for heterostructural formation between materials with the desired properties. Here we harness an increased knowledge of metal-on-semiconductor growth to develop InAs nanowires with epitaxially matched, single-crystal, atomically flat Pb films with no axial grain boundaries. These highly ordered heterostructures have a critical temperature of 7 K and a superconducting gap of 1.25 meV, which remains hard at 8.5 T, and therefore they offer a parameter space more than twice as large as those of alternative semiconductor-superconductor hybrids. Additionally, InAs/Pb island devices exhibit magnetic field-driven transitions from a Cooper pair to single-electron charging, a prerequisite for use in topological quantum computation. Semiconductor-Pb hybrids potentially enable access to entirely new regimes for a number of different quantum systems.
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| 7. |
- Larsson, Ragnar, 1960, et al.
(författare)
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A micromechanically based model for dynamic damage evolution in unidirectional composites
- 2022
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Ingår i: International Journal of Solids and Structures. - : Elsevier Ltd. - 0020-7683 .- 1879-2146. ; 238
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Tidskriftsartikel (refereegranskat)abstract
- This article addresses the micromechanically motivated, quasistatic to dynamic, failure response of fibre reinforced unidirectional composites at finite deformation. The model draws from computational homogenization, with a subscale represented by matrix and fibre constituents. Undamaged matrix response assumes isotropic viscoelasticity–viscoplasticity, whereas the fibre is transversely isotropic hyperelastic. Major novelties involve damage degradation of the matrix response, due to shear in compression based on a rate dependent damage evolution model, and the large deformation homogenization approach. The homogenized quasi-brittle damage induced failure is described by elastically stored isochoric energy and plastic work of the undamaged polymer, driving the evolution of damage. The developed model is implemented in ABAQUS/Explicit. Finite element validation is carried out for a set of off-axis experimental compression tests in the literature. Considering the unidirectional carbon–epoxy (IM7/8552) composite at different strain rates, it appears that the homogenized damage degraded response can represent the expected ductile failure of the composite at compressive loading with different off-axes. Favourable comparisons are made for the strain and fibre rotation distribution involving localized shear and fibre kinking. © 2021 The Authors
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| 8. |
- Larsson, Ragnar, 1960, et al.
(författare)
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A micromechanically based model for strain rate effects in unidirectional composites
- 2020
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Ingår i: Mechanics of materials. - : Elsevier B.V.. - 0167-6636 .- 1872-7743. ; 148
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Tidskriftsartikel (refereegranskat)abstract
- This article addresses dynamic behaviour of fibre reinforced polymer composites in terms of a transversely isotropic viscoelastic-viscoplastic constitutive model established at the unidirectional ply level. The model captures the prelocalized response of the ply in terms of rate dependent elasticity and strength without damage. A major novelty is that the model draws from computational homogenization, with matrix and fibre materials as subscale constituents for a representative volume element of the ply. The micromechanics of the strain rate dependent polymer matrix is represented by an isotropic pressure sensitive viscoelastic-viscoplastic prototype model. For the fibre material, transverse elasticity is assumed. The constituents are homogenized via the fluctuating strain of the subscale, where a simple ansatz is applied to allow for constant stress in the plane transverse to the fibre orientation. Despite the relatively simple modelling assumptions for the constituents, the homogenized model compares favourably to experimental data for an epoxy/carbon fibre based composite, subjected to a variety of challenging uniaxial off-axis tests. The model response clearly reflects observed strain rate dependencies under both tensile and compressive loadings.
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| 9. |
- Singh, Vivekendra, et al.
(författare)
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A micromechanics based model for rate dependent compression loaded unidirectional composites
- 2023
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Ingår i: Composites Science And Technology. - : Elsevier Ltd. - 0266-3538 .- 1879-1050. ; 232
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Tidskriftsartikel (refereegranskat)abstract
- Strain-rate effects in a unidirectional non-crimp fabric carbon/epoxy composite are addressed. To allow for kink-band formation including strain-rate effects and damage in such composites, the paper advances a recent model focused on compression loading at small off-axis angles. The model is based on computational homogenization with a subscale represented by matrix and fibre constituents at finite deformation. The fibre constituent is assumed to be elastic transversely isotropic and the matrix is viscoelastic–viscoplastic with damage degradation. Novel model improvements of special importance to small off-axis loading relate to the isostress formulation of the homogenized response in transverse shear. In this context, an enhanced homogenized elastic response is proposed based on Halpin–Tsai corrections to account for the nonuniform stress distribution on the microscale. The model captures the strongly rate sensitive kink-band formation due to localized matrix shearing and fibre rotation, confirming the experimentally observed increase in compressive strength for high strain rates. © 2022 The Author(s)
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| 10. |
- Singh, Vivekendra, 1987, et al.
(författare)
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Application of a Rate Dependent Model on a UD NCF Carbon/Epoxy Composite
- 2021
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Ingår i: PROCEEDINGS - 8th ECCOMAS THEMATIC CONFERENCE ON THE MECHANICAL RESPONSE OF COMPOSITES. - : CIMNE.
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Konferensbidrag (refereegranskat)abstract
- To support the modelling of composites under rapid transient loading, e.g. impact, crash, and vibrations, a computational multiscale constitutive model has been developed for the progressive failure of unidirectional carbon fibre composites. The model is computationally efficient and captures anticipated failure modes to an acceptable accuracy. Computational homogenization and micromechanics are utilized in the modelling at the ply scale. A major focus is to predict the strain rate dependent nonlinear constitutive behaviour of unidirectional composite plies. The fibres are assumed transversely isotropic, whereas the polymer is viscoelastic–viscoplastic, including a pressure-dependent strength. Degradation of the polymer matrix is described by a recently developed continuum damage mechanics approach. The model has been successfully implemented as a VUMAT subroutine in Abaqus/Explicit. Figure 1 shows FE simulation of strain localization as compared to experimental results of IM7/8552 in dynamic off-axis compression. Reasonable correlation was found between the measured and numerically predicted results. In the present paper the model is applied to simulate quasi-static and dynamic off-axis tension and compression experiments on composite coupons studied in two of our collaborative projects. The composite is a unidirectional (UD) carbon fibre non-crimp fabric (NCF) uniweave impregnated with LY556 epoxy, manufactured by Resin Transfer Moulding (RTM). The tests have been performed using a high-speed hydraulic test machine and a Split Hopkinson Bar (SHB) setup, involving strain rates of up to about 140 /s in tension and 1100 /s in compression.
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