| 1. |
- Akiba, K., et al.
(author)
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The LHCb VELO Upgrade module construction
- 2024
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In: Journal of Instrumentation. - : Institute of Physics Publishing (IOPP). - 1748-0221. ; 19:6
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Journal article (peer-reviewed)abstract
- The LHCb detector has undergone a major upgrade for LHC Run 3. This Upgrade I detector facilitates operation at higher luminosity and utilises full-detector information at the LHC collision rate, critically including the use of vertex information. A new vertex locator system, the VELO Upgrade, has been constructed. The core element of the new VELO are the double-sided pixelated hybrid silicon detector modules which operate in vacuum close to the LHC beam in a high radiation environment. The construction and quality assurance tests of these modules are described in this paper. The modules incorporate 200 mu m thick, n -on -p silicon sensors bump-bonded to 130 nm technology ASICs. These are attached with high precision to a silicon microchannel substrate that uses evaporative CO 2 cooling. The ASICs are controlled and read out with flexible printed circuits that are glued to the substrate and wire -bonded to the chips. The mechanical support of the module is given by a carbon fibre plate, two carbon fibre rods and an aluminium plate. The sensor attachment was achieved with an average precision of 21 mu m, more than 99.5% of all pixels are fully functional, and a thermal figure of merit of 3 Kcm 2 W - 1 was achieved. The production of the modules was successfully completed in 2021, with the final assembly and installation completed in time for data taking in 2022.
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| 2. |
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| 3. |
- Jans, A., et al.
(author)
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Impact of dietary fat quantity and quality on skeletal muscle fatty acid metabolism in subjects with the metabolic syndrome
- 2012
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In: Metabolism. - : Elsevier BV. - 0026-0495 .- 1532-8600. ; 61:11, s. 1554-1565
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Journal article (peer-reviewed)abstract
- Insulin resistance is characterized by disturbances in lipid metabolism in skeletal muscle. Our aim was to investigate whether gene expression and fatty acid (FA) profile of skeletal muscle lipids are affected by diets differing in fat quantity and quality in subjects with the metabolic syndrome (MetS) and varying degrees of insulin sensitivity. 84 subjects (age 57.3 ± 0.9 y, BMI 30.9 ± 0.4 kg/m 2, 42 M/42 F) were randomly assigned to one of four iso-energetic diets: high-SFA (HSFA); high-MUFA (HMUFA) or two low-fat, high-complex carbohydrate diets, supplemented with 1.24 g/day of long-chain n-3 PUFA (LFHCCn-3) or control oil (LFHCC) for 12 weeks. In a subgroup of men (n = 26), muscle TAG, DAG, FFA and phospholipid contents were determined including their fractional synthetic rate (FSR) and FA composition at fasting and 4 h after consumption of a high-fat mixed-meal, both pre- and post-intervention. Genes involved in lipogenesis were downregulated after HMUFA (mean fold change - 1.3) and after LFHCCn-3 (fold change - 1.7) in insulin resistant subjects (< median of (S I)), whereas in insulin sensitive subjects (> median of insulin sensitivity) the opposite effect was shown (fold change + 1.6 for both diets). HMUFA diet tended to decrease FSR in TAG (P =.055) and DAG (P =.066), whereas the LFHCCn-3 diet reduced TAG content (P =.032). In conclusion, HMUFA and LFHCCn-3 diets reduced the expression of the lipogenic genes in skeletal muscle of insulin resistant subjects, whilst HMUFA reduced the fractional synthesis rate of DAG and TAG and LFHCC n-3 the TAG content. Our data indicate that these diets may reduce muscle fat accumulation by affecting the balance between FA synthesis, storage and oxidation.
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| 4. |
- Sarneel, Judith M., et al.
(author)
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Reading tea leaves worldwide : decoupled drivers of initial litter decomposition mass-loss rate and stabilization
- 2024
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In: Ecology Letters. - : John Wiley & Sons. - 1461-023X .- 1461-0248. ; 27:5
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Journal article (peer-reviewed)abstract
- The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.
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| 5. |
- Akiba, K., et al.
(author)
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Measurement of thermal properties of the LHCb VELO detector using track-based software alignment
- 2023
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In: Journal of Instrumentation. - : Institute of Physics (IOP). - 1748-0221. ; 18:10
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Journal article (peer-reviewed)abstract
- The thermal properties of the LHCb Vertex Locator (VELO) are studied using the real-time detector alignment procedure. The variation of the position and orientation of the detector elements as a function of the operating temperature of the VELO is presented. This study uses a dataset collected by the LHCb experiment during a VELO temperature scan performed at the end of LHC Run 2 (October 2018). Significant shrinkage of the VELO modules is observed at the operating temperature of -30(degrees)C compared to the laboratory measurements on a single module taken at a range of temperatures from +45(degrees)C to -25(degrees)C. The thermal shrinkage expected from the extrapolation of laboratory measurements to lower temperatures, and the results of this alignment study are in good agreement.
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| 6. |
- Gjelstad, I. M. F., et al.
(author)
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Expression of perilipins in human skeletal muscle in vitro and in vivo in relation to diet, exercise and energy balance
- 2012
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In: Archives of Physiology and Biochemistry. - : Informa UK Limited. - 1381-3455 .- 1744-4160. ; 118:1, s. 22-30
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Journal article (peer-reviewed)abstract
- The perilipin proteins enclose intracellular lipid droplets. We describe the mRNA expression of the five perilipins in human skeletal muscle in relation to fatty acid supply, exercise and energy balance. We observed that all perilipins were expressed in skeletal muscle biopsies with the highest mRNA levels of perilipin 2, 4 and 5. Cultured myotubes predominantly expressed perilipin 2 and 3. In vitro, incubation of myotubes with fatty acids enhanced mRNA expression of perilipin 1, 2 and 4. In vivo, low fat diet increased mRNA levels of perilipin 3 and 4. Endurance training, but not strength training, enhanced the expression of perilipin 2 and 3. Perilipin 1 mRNA correlated positively with body fat mass, whereas none of the perilipins were associated with insulin sensitivity. In conclusion, all perilipins mRNAs were expressed in human skeletal muscle. Diet as well as endurance exercise modulated the expression of perilipins.
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| 7. |
- Pekkinen, M., et al.
(author)
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Osteoporosis and skeletal dysplasia caused by pathogenic variants in SGMS2
- 2019
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In: Jci Insight. - : American Society for Clinical Investigation. - 2379-3708. ; 4:7
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Journal article (peer-reviewed)abstract
- Mechanisms leading to osteoporosis are incompletely understood. Genetic disorders with skeletal fragility provide insight into metabolic pathways contributing to bone strength. We evaluated 6 families with rare skeletal phenotypes and osteoporosis by next-generation sequencing. In all the families, we identified a heterozygous variant in SGMS2, a gene prominently expressed in cortical bone and encoding the plasma membrane-resident sphingomyelin synthase SMS2. Four unrelated families shared the same nonsense variant, c.148C>T (p.Arg50*), whereas the other families had a missense variant, c.185T>G (p.IIe62Ser) or c.191T>G (p.Met64Arg). Subjects with p.Arg50* presented with childhood-onset osteoporosis with or without cranial sclerosis. Patients with p.IIe62Ser or p.Met64Arg had a more severe presentation, with neonatal fractures, severe short stature, and spondylometaphyseal dysplasial Several subjects had experienced peripheral facial nerve palsy or other neurological manifestations. Bone biopsies showed markedly altered bone material characteristics, including defective bone mineralization. Osteoclast formation and function in vitro was normal. While the p.Arg50* mutation yielded a catalytically inactive enzyme, p.IIe62Ser and p.Met64Arg each enhanced the rate of de novo sphingomyelin production by blocking export of a functional enzyme from the endoplasmic reticulum. SGMS2 pathogenic variants underlie a spectrum of skeletal conditions, ranging from isolated osteoporosis to complex skeletal dysplasia, suggesting a critical role for plasma membrane-bound sphingomyelin metabolism in skeletal homeostasis.
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| 8. |
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| 9. |
- Abrahamsson, S., et al.
(author)
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Multifocus structured illumination microscopy for fast volumetric super-resolution imaging
- 2017
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In: Biomedical Optics Express. - : OSA - The Optical Society. - 2156-7085. ; 8:9, s. 4135-4140
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Journal article (peer-reviewed)abstract
- We here report for the first time the synergistic implementation of structured illumination microscopy (SIM) and multifocus microscopy (MFM). This imaging modality is designed to alleviate the problem of insufficient volumetric acquisition speed in superresolution biological imaging. SIM is a wide-field super-resolution technique that allows imaging with visible light beyond the classical diffraction limit. Employing multifocus diffractive optics we obtain simultaneous wide-field 3D imaging capability in the SIM acquisition sequence, improving volumetric acquisition speed by an order of magnitude. Imaging performance is demonstrated on biological specimens.
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| 10. |
- Johansson, Magnus, et al.
(author)
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A small region of the dengue virus-encoded RNA-dependent RNA polymerase, NS5, confers interaction with both the nuclear transport receptor importin-beta and the viral helicase, NS3
- 2001
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In: Journal of General Virology. - : Microbiology Society. - 0022-1317 .- 1465-2099. ; 82:Pt 4, s. 735-745
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Journal article (peer-reviewed)abstract
- The dengue virus RNA-dependent RNA polymerase, NS5, and the protease/helicase, NS3, are multidomain proteins that have been shown to interact both in vivo and in vitro. A hyperphosphorylated form of NS5 that does not interact with NS3 has been detected in the nuclei of virus-infected cells, presumably as the result of the action of a functional nuclear localization sequence within the interdomain region of NS5 (residues 369-405). In this study, it is shown by using the yeast two-hybrid system that the C-terminal region of NS3 (residues 303-618) interacts with the N-terminal region of NS5 (residues 320-368). Further, it is shown that this same region of NS5 is also recognized by the cellular nuclear import receptor importin-beta. The interaction between NS5 and importin-beta and competition by NS3 with the latter for the same binding site on NS5 were confirmed by pull-down assays. The direct interaction of importin-beta with NS5 has implications for the mechanism by which this normally cytoplasmic protein may be targetted to the nucleus.
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