| 1. |
|
|
| 2. |
- Ananthanarayanan, Durga, et al.
(författare)
-
Phase-field study of IMC growth in Sn-Cu/Cu solder joints including elastoplastic effects
- 2020
-
Ingår i: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 188, s. 241-258
-
Tidskriftsartikel (refereegranskat)abstract
- In this article, we aim to study the problem of the growth of intermetallic phases in solder joints undergoing mechanical deformation, using a phase-field model for multi-phase systems that can treat diffusion, elastic and plastic deformation. A suitable model is formulated and applied to Sn-Cu/Cu lead-free solder joints. The growth of the intermetallic layers during solid-state annealing is simulated for different strain states. We assess the values of stiffness tensors available in literature and perform ab initio calculations to support the selection of reasonable values from literature. We also perform a parametric study with different eigenstrain values and applied strains. We find that there is a significant effect of the considered eigenstrains and applied strains on the growth kinetics of the system and parabolic growth kinetics is followed in cases where the intermetallic layers grow. We thereby establish the importance of strain in the growth of intermetallic layers and the need for more targeted experiments on the role of strain in the reliability of the solder joint.
|
|
| 3. |
- Krebs, Finja, et al.
(författare)
-
Strategies for capillary electrophoresis : Method development and validation for pharmaceutical and biological applications-Updated and completely revised edition
- 2023
-
Ingår i: Electrophoresis. - : John Wiley & Sons. - 0173-0835 .- 1522-2683. ; 44:17-18, s. 1279-1341
-
Forskningsöversikt (refereegranskat)abstract
- This review is in support of the development of selective, precise, fast, and validated capillary electrophoresis (CE) methods. It follows up a similar article from 1998, Watzig H, Degenhardt M, Kunkel A. "Strategies for capillary electrophoresis: method development and validation for pharmaceutical and biological applications," pointing out which fundamentals are still valid and at the same time showing the enormous achievements in the last 25 years. The structures of both reviews are widely similar, in order to facilitate their simultaneous use. Focusing on pharmaceutical and biological applications, the successful use of CE is now demonstrated by more than 600 carefully selected references. Many of those are recent reviews; therefore, a significant overview about the field is provided. There are extra sections about sample pretreatment related to CE and microchip CE, and a completely revised section about method development for protein analytes and biomolecules in general. The general strategies for method development are summed up with regard to selectivity, efficiency, precision, analysis time, limit of detection, sample pretreatment requirements, and validation.
|
|
| 4. |
- Bhogal, P, et al.
(författare)
-
Treatment of cerebral vasospasm with self-expandable retrievable stents: proof of concept
- 2017
-
Ingår i: Journal of neurointerventional surgery. - : BMJ. - 1759-8486 .- 1759-8478. ; 9:1, s. 52-59
-
Tidskriftsartikel (refereegranskat)abstract
- To report our preliminary experience with the use of stent retrievers to cause vasodilation in patients with delayed cerebral vasospasm secondary to subarachnoid hemorrhage.MethodsFour patients from two different high volume neurointerventional centers developed cerebral vasospasm following subarachnoid hemorrhage. In addition to standard techniques for the treatment of cerebral vasospasm, we used commercially available stent retrievers (Solitaire and Capture stent retrievers) to treat the vasospastic segment including M2, M1, A2, and A1. We evaluated the safety of this technique, degree of vasodilation, and longevity of the effect.ResultsStent retrievers can be used to safely achieve cerebral vasodilation in the setting of delayed cerebral vasospasm. The effect is long-lasting (>24 hours) and, in our initial experience, carries a low morbidity. We have not experienced any complications using this technique although we have noted that the radial force was not sufficient to cause vasodilation in some instances. The vasospasm did not return in the vessel segments treated with stent angioplasty in any of these cases. In two of our cases stent angioplasty resulted in the reversal of focal neurological symptoms.ConclusionsStent retrievers can provide long-lasting cerebral vasodilation in patients with delayed cerebral vasospasm.
|
|
| 5. |
- Nicholas, Lisa M, et al.
(författare)
-
Exposure to maternal obesity programs sex differences in pancreatic islets of the offspring in mice
- 2020
-
Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 63:2, s. 324-337
-
Tidskriftsartikel (refereegranskat)abstract
- AIMS/HYPOTHESIS: Obesity during pregnancy increases offspring type 2 diabetes risk. Given that nearly half of women of child-bearing age in many populations are currently overweight/obese, it is key that we improve our understanding of the impact of the in utero/early life environment on offspring islet function. Whilst a number of experimental studies have examined the effect of maternal obesity on offspring islet architecture and/or function, it has not previously been delineated whether these changes are independent of other confounding risk factors such as obesity, postnatal high-fat-feeding and ageing. Thus, we aimed to study the impact of exposure to maternal obesity on offspring islets in young, glucose-tolerant male and female offspring.METHODS: Female C57BL/6J mice were fed ad libitum either chow or obesogenic diet prior to and throughout pregnancy and lactation. Offspring were weaned onto a chow diet and remained on this diet until the end of the study. An IPGTT was performed on male and female offspring at 7 weeks of age. At 8 weeks of age, pancreatic islets were isolated from offspring for measurement of insulin secretion and content, mitochondrial respiration, ATP content, reactive oxygen species levels, beta and alpha cell mass, granule and mitochondrial density (by transmission electron microscopy), and mRNA and protein expression by real-time RT-PCR and Western blotting, respectively.RESULTS: Glucose tolerance was similar irrespective of maternal diet and offspring sex. However, blood glucose was lower (p < 0.001) and plasma insulin higher (p < 0.05) in female offspring of obese dams 15 min after glucose administration. This was associated with higher glucose- (p < 0.01) and leucine/glutamine-stimulated (p < 0.05) insulin secretion in these offspring. Furthermore, there was increased mitochondrial respiration (p < 0.01) and density (p < 0.05) in female offspring of obese dams compared with same-sex controls. Expression of mitochondrial and nuclear-encoded components of the electron transport chain, L-type Ca2+ channel subtypes that play a key role in stimulus-secretion coupling [Cacna1d (p < 0.05)], and oestrogen receptor α (p < 0.05) was also increased in islets from these female offspring of obese dams. Moreover, cleaved caspase-3 expression and BAX:Bcl-2 were decreased (p < 0.05) reflecting reduced susceptibility to apoptosis. In contrast, in male offspring, glucose and leucine/glutamine-stimulated insulin secretion was comparable between treatment groups. There was, however, compromised mitochondrial respiration characterised by decreased ATP synthesis-driven respiration (p < 0.05) and increased uncoupled respiration (p < 0.01), reduced docked insulin granules (p < 0.001), decreased Cacna1c (p < 0.001) and Cacna1d (p < 0.001) and increased cleaved caspase-3 expression (p < 0.05).CONCLUSIONS/INTERPRETATION: Maternal obesity programs sex differences in offspring islet function. Islets of female but not male offspring appear to be primed to cope with a nutritionally-rich postnatal environment, which may reflect differences in future type 2 diabetes risk.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Agudelo, LZ, et al.
(författare)
-
Skeletal muscle PGC-1α1 reroutes kynurenine metabolism to increase energy efficiency and fatigue-resistance
- 2019
-
Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1, s. 2767-
-
Tidskriftsartikel (refereegranskat)abstract
- The coactivator PGC-1α1 is activated by exercise training in skeletal muscle and promotes fatigue-resistance. In exercised muscle, PGC-1α1 enhances the expression of kynurenine aminotransferases (Kats), which convert kynurenine into kynurenic acid. This reduces kynurenine-associated neurotoxicity and generates glutamate as a byproduct. Here, we show that PGC-1α1 elevates aspartate and glutamate levels and increases the expression of glycolysis and malate-aspartate shuttle (MAS) genes. These interconnected processes improve energy utilization and transfer fuel-derived electrons to mitochondrial respiration. This PGC-1α1-dependent mechanism allows trained muscle to use kynurenine metabolism to increase the bioenergetic efficiency of glucose oxidation. Kat inhibition with carbidopa impairs aspartate biosynthesis, mitochondrial respiration, and reduces exercise performance and muscle force in mice. Our findings show that PGC-1α1 activates the MAS in skeletal muscle, supported by kynurenine catabolism, as part of the adaptations to endurance exercise. This crosstalk between kynurenine metabolism and the MAS may have important physiological and clinical implications.
|
|
| 9. |
- Agudelo, Leandro Z., et al.
(författare)
-
Metabolic resilience is encoded in genome plasticity
- 2021
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Metabolism plays a central role in evolution, as resource conservation is a selective pressure for fitness and survival.Resource-driven adaptations offer a good model to study evolutionary innovation more broadly. It remains unknown howresource-driven optimization of genome function integrates chromatin architecture with transcriptional phase transitions.Here we show that tuning of genome architecture and heterotypic transcriptional condensates mediate resilience tonutrient limitation. Network genomic integration of phenotypic, structural, and functional relationships reveals that fattissue promotes organismal adaptations through metabolic acceleration chromatin domains and heterotypic PGC1Acondensates. We find evolutionary adaptations in several dimensions; low conservation of amino acid residues withinprotein disorder regions, nonrandom chromatin location of metabolic acceleration domains, condensate-chromatin stabilitythrough cis-regulatory anchoring and encoding of genome plasticity in radial chromatin organization. We show thatenvironmental tuning of these adaptations leads to fasting endurance, through efficient nuclear compartmentalization oflipid metabolic regions, and, locally, human-specific burst kinetics of lipid cycling genes. This process reduces oxidativestress, and fatty-acid mediated cellular acidification, enabling endurance of condensate chromatin conformations.Comparative genomics of genetic and diet perturbations reveal mammalian convergence of phenotype and structuralrelationships, along with loss of transcriptional control by diet-induced obesity. Further, we find that radial transcriptionalorganization is encoded in functional divergence of metabolic disease variant-hubs, heterotypic condensate composition,and protein residues sensing metabolic variation. During fuel restriction, these features license the formation of largeheterotypic condensates that buffer proton excess, and shift viscoelasticity for condensate endurance. This mechanismmaintains physiological pH, reduces pH-resilient inflammatory gene programs, and enables genome plasticity throughtranscriptionally driven cell-specific chromatin contacts. In vivo manipulation of this circuit promotes fasting-likeadaptations with heterotypic nuclear compartments, metabolic and cell-specific homeostasis. In sum, we uncover here ageneral principle by which transcription uses environmental fluctuations for genome function, and demonstrate howresource conservation optimizes transcriptional self-organization through robust feedback integrators, highlighting obesityas an inhibitor of genome plasticity relevant for many diseases.
|
|
| 10. |
- Bakker, Jimmy W.P., et al.
(författare)
-
Computer screen photo-assisted off-null ellipsometry
- 2006
-
Ingår i: Applied Optics. - 1559-128X .- 2155-3165. ; 45:30, s. 7795-7799
-
Tidskriftsartikel (refereegranskat)abstract
- The ellipsometric measurement of thickness is demonstrated using a computer screen as a light source and a webcam as a detector, adding imaging off-null ellipsometry to the range of available computer screen photoassisted techniques. The results show good qualitative agreement with a simplified theoretical model and a thickness resolution in the nanometer range is achieved. The presented model can be used to optimize the setup for sensitivity. Since the computer screen serves as a homogeneous large area illumination source, which can be tuned to different intensities for different parts of the sample, a large sensitivity range can be obtained without sacrificing thickness resolution.
|
|
