| 1. |
- Mörck, Catarina, 1972, et al.
(author)
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Statins inhibit protein lipidation and induce the unfolded protein response in the non-sterol producing nematode Caenorhabditis elegans
- 2009
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In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 106:43, s. 18285-90
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Journal article (peer-reviewed)abstract
- Statins are compounds prescribed to lower blood cholesterol in millions of patients worldwide. They act by inhibiting HMG-CoA reductase, the rate-limiting enzyme in the mevalonate pathway that leads to the synthesis of farnesyl pyrophosphate, a precursor for cholesterol synthesis and the source of lipid moieties for protein prenylation. The nematode Caenorhabditis elegans possesses a mevalonate pathway that lacks the branch leading to cholesterol synthesis, and thus represents an ideal organism to specifically study the noncholesterol roles of the pathway. Inhibiting HMG-CoA reductase in C. elegans using statins or RNAi leads to developmental arrest and loss of membrane association of a GFP-based prenylation reporter. The unfolded protein response (UPR) is also strongly activated, suggesting that impaired prenylation of small GTPases leads to the accumulation of unfolded proteins and ER stress. UPR induction was also observed upon pharmacological inhibition of farnesyl transferases or RNAi inhibition of a specific isoprenoid transferase (M57.2) and found to be dependent on both ire-1 and xbp-1 but not on pek-1 or atf-6, which are all known regulators of the UPR. The lipid stores and fatty acid composition were unaffected in statin-treated worms, even though they showed reduced staining with Nile red. We conclude that inhibitors of HMG-CoA reductase or of farnesyl transferases induce the UPR by inhibiting the prenylation of M57.2 substrates, resulting in developmental arrest in C. elegans. These results provide a mechanism for the pleiotropic effects of statins and suggest that statins could be used clinically where UPR activation may be of therapeutic benefit.
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| 2. |
- Almqvist, Andreas, et al.
(author)
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Interfacial separation between elastic solids with randomly rough surfaces : Comparison between theory and numerical techniques
- 2011
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In: Journal of the mechanics and physics of solids. - : Elsevier BV. - 0022-5096 .- 1873-4782. ; 59:11, s. 2355-2369
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Journal article (peer-reviewed)abstract
- We study the distribution of interfacial separations at the contact region between two elastic solids with randomly rough surfaces. An analytical expression is derived for the distribution of interfacial separations using Persson's theory of contact mechanics, and is compared to numerical solutions obtained using (a) a half-space method based on the Boussinesq equation, (b) a Green's function molecular dynamics technique and (c) smart-block classical molecular dynamics. Overall, we find good agreement between all the different approaches.
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| 5. |
- Flook, N. W., et al.
(author)
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Acid-Suppressive Therapy With Esomeprazole for Relief of Unexplained Chest Pain in Primary Care: A Randomized, Double-Blind, Placebo-Controlled Trial
- 2013
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In: American Journal of Gastroenterology. - : Ovid Technologies (Wolters Kluwer Health). - 0002-9270. ; 108:1, s. 56-64
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Journal article (peer-reviewed)abstract
- OBJECTIVES: High-quality data regarding the efficacy of acid-suppressive treatment for unexplained chest pain are lacking. The aim of this study was to evaluate the efficacy of esomeprazole in primary-care treatment of patients with unexplained chest pain stratified for frequency of reflux/regurgitation symptoms. METHODS: Patients with a ≥2-week history of unexplained chest pain (unrelated to gastroesophageal reflux) who had at least moderate pain on ≥2 of the last 7 days were stratified by heartburn/regurgitation frequency (≤1 day/week (stratum 1) vs. ≥2 days/week (stratum 2)) and randomized to 4 weeks of double-blind treatment with twice-daily esomeprazole 40mg or placebo. Chest pain relief during the last 7 days of treatment (≤1 day with minimal symptoms assessed daily using a 7-point scale) was analyzed by stratum in keeping with the predetermined analysis plan. RESULTS: Overall, 599 patients (esomeprazole: 297, placebo: 302) were randomized. In stratum 1, more esomeprazole than placebo recipients achieved chest pain relief (38.7% vs. 25.5%; P=0.018); no between-treatment difference was observed in stratum 2 (27.2% vs. 24.2%; P=0.54). However, esomeprazole was superior to placebo in a post-hoc analysis of the whole study population (combined strata; 33.1% vs. 24.9%; P=0.035). CONCLUSIONS: A 4-week course of high-dose esomeprazole provided statistically significant relief of unexplained chest pain in primary-care patients who experienced infrequent or no heartburn/regurgitation, but there was no such significant reduction in patients with more frequent reflux symptoms.
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| 6. |
- Georgieva, Iskra, 1987, et al.
(author)
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Hot planets around cool stars - two short-period mini-Neptunes transiting the late K-dwarf TOI-1260
- 2021
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In: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 505:4, s. 4684-4701
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Journal article (peer-reviewed)abstract
- We present the discovery and characterization of two sub-Neptunes in close orbits, as well as a tentative outer planet of a similar size, orbiting TOI-1260 - a low metallicity K6V dwarf star. Photometry from Transiting Exoplanet Survey Satellite(TESS) yields radii of R-b = 2.33 +/- 0.10 and R-c = 2.82 +/- 0.15 R-circle plus, and periods of 3.13 and 7.49 d for TOI-1260b and TOI-1260c, respectively. We combined the TESS data with a series of ground-based follow-up observations to characterize the planetary system. From HARPS-N high-precision radial velocities we obtain M-b = and M-c = M-circle plus. The star is moderately active with a complex activity pattern, which necessitated the use of Gaussian process regression for both the light-curve detrending and the radial velocity modelling, in the latter case guided by suitable activity indicators. We successfully disentangle the stellar-induced signal from the planetary signals, underlining the importance and usefulness of the Gaussian process approach. We test the system's stability against atmospheric photoevaporation and find that the TOI-1260 planets are classic examples of the structure and composition ambiguity typical for the 2-3 R-circle plus range.
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| 7. |
- Hayashi, M., et al.
(author)
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Lateral hopping of CO molecules on Pt(111) surface by femtosecond laser pulses
- 2009
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In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 80:Article number: 245409
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Journal article (peer-reviewed)abstract
- Theory of heat transfer between adsorbate vibrational degrees of freedom and ultrafast laser heated hot electrons including vibrational intermode coupling is applied to calculate two-pulse correlation, laser fluence dependence and time dependence of lateral hopping of CO molecules from a step to terrace site on a stepped Pt (111) surface. The intermode coupling is a key ingredient to describe vibrational heating of the frustrated translation mode responsible for the CO hopping. The calculated results are in good agreement with the experimental results, especially if we scale down the experimentally determined absorbed fluence. It is found that CO hopping is induced by indirect heating of the FT mode by the FR mode with a strong frictional coupling to hot electrons.
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| 8. |
- Hoyer, S., et al.
(author)
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TOI-220b: a warm sub-Neptune discovered by TESS
- 2021
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In: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 505:3, s. 3361-3379
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Journal article (peer-reviewed)abstract
- In this paper, we report the discovery of TOI-220b, a new sub-Neptune detected by the Transiting Exoplanet Survey Satellite (TESS) and confirmed by radial velocity follow-up observations with the HARPS spectrograph. Based on the combined analysis of TESS transit photometry and high precision radial velocity measurements, we estimate a planetary mass of 13.8 +/- 1.0M(circle plus) and radius of 3.03 +/- 0.15R(circle plus), implying a bulk density of 2.73 +/- 0.47. TOI-220b orbits a relative bright (V=10.4) and old (10.1 +/- 1.4Gyr) K dwarf star with a period of similar to 10.69d. Thus, TOI-220b is a new warm sub-Neptune with very precise mass and radius determinations. A Bayesian analysis of the TOI-220b internal structure indicates that due to the strong irradiation it receives, the low density of this planet could be explained with a steam atmosphere in radiative-convective equilibrium and a supercritical water layer on top of a differentiated interior made of a silicate mantle and a small iron core.
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| 9. |
- Ishaq, R., et al.
(author)
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PCNs, PCDD/Fs, and Non-orthoPCBs, in Water and Bottom Sediments from the Industrialized Norwegian Grenlandsfjords
- 2009
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In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 43:10, s. 3442-3447
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Journal article (peer-reviewed)abstract
- Chlorinated toxic planar aromatic compounds were analyzed in the heavily industrialized Grenlandsfjords, which is a system of silled fjords in southern Norway. Surface water samples contained 7.4-160 ng/m(3) polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), 14-410 ng/m(3) polychlorinated naphthalenes (PCNs), and 0.31-2.4 ng/m(3) non-orthochlorinated biphenyls (non-orthoPCBs). The concentrations of PCDD/Fs were about 300 times higher than in the Baltic Sea. Highest level of the compounds was found near a magnesium production plant. Hepta-CDFs and penta-CNs dominated in the inner-fiord waters, and tetra-CB77 was the major non-orthoPCB congener. Sediment samples had PCDD/F concentration of 25-730 ng/g dw. Highest concentration was detected close to the magnesium plant. Octa-CDF dominated in the fjord sediments, especially near the magnesium plant, indicating a discharge-specific contamination with this congener. The isomer composition of PCDD/Fs and of PCNs, was unchanged when comparing samples from different layers of a sediment core from the deep anoxic water. This concludes that essentially zero degradation had occurred during similar to 50 years in this environment
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| 10. |
- Kalliorinne, Kalle, et al.
(author)
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Characterisation of the Contact between Cross-Country Skis and Snow: A Micro-Scale Study Considering the Ski-Base Texture
- 2023
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In: Lubricants. - : MDPI. - 2075-4442. ; 11:5
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Journal article (peer-reviewed)abstract
- In winter sports, the equipment often comes into contact with snow or ice, and this contact generates a force that resists motion. In some sports, such as cross-country skiing, this resistive force can significantly affect the outcome of a race, as a small reduction in this force can give an athlete an advantage. Researchers have examined the contact between skis and snow in detail, and to fully understand this friction, the entire ski must be studied at various scales. At the macro scale, the entire geometry of the ski is considered and the apparent contact between the ski and the snow is considered and at the micro-scale the contact between the snow and the ski-base textures. In the present work, a method for characterising the contact between the ski-base texture and virtual snow will be presented. Six different ski-base textures will be considered. Five of them are stone-ground ski bases, and three of them have longitudinal linear textures with a varying number of lines and peak-to-valley heights, and the other two are factory-ground “universal” ski bases. The sixth ski base has been fabricated by a steel-scraping procedure. In general, the results show that a ski base texture with a higher ??? value has less real contact area, and that the mutual differences can be large for surfaces with similar ?? values. The average interfacial separation is, in general, correlated with the ?? value, where a “rougher” surface exhibits a larger average interfacial separation. The results for the reciprocal average interfacial separation, which is related to the Couette type of viscous friction, were in line with the general consensus that a “rougher” texture performs better at high speed than a “smoother” one, and it was found that a texture with high ?? and ??? values resulted in a low reciprocal average interfacial separation and consequently low viscous friction. The reciprocal average interfacial separation was found to increase with increasing real contact area, indicating a correlation between the real area of contact and the Couette part of the viscous friction.
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