| 1. |
- Allard, Christina, et al.
(författare)
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Rasbiologiskt språkbruk i statens rättsprocess mot sameby
- 2015
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Ingår i: Dagens Nyheter. - 1101-2447.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Statens hantering av forskningsresultat i rättsprocessen med Girjas sameby utgör ett hot mot Sverige som rättsstat och kunskapsnation. Åratal av svensk och internationell forskning underkänns och man använder ett språkbruk som skulle kunna vara hämtat från rasbiologins tid. Nu måste staten ta sitt ansvar och börja agera som en demokratisk rättsstat, skriver 59 forskare.
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| 2. |
- Pattaro, Cristian, et al.
(författare)
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Genetic associations at 53 loci highlight cell types and biological pathways relevant for kidney function
- 2016
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Reduced glomerular filtration rate defines chronic kidney disease and is associated with cardiovascular and all-cause mortality. We conducted a meta-analysis of genome-wide association studies for estimated glomerular filtration rate (eGFR), combining data across 133,413 individuals with replication in up to 42,166 individuals. We identify 24 new and confirm 29 previously identified loci. Of these 53 loci, 19 associate with eGFR among individuals with diabetes. Using bioinformatics, we show that identified genes at eGFR loci are enriched for expression in kidney tissues and in pathways relevant for kidney development and transmembrane transporter activity, kidney structure, and regulation of glucose metabolism. Chromatin state mapping and DNase I hypersensitivity analyses across adult tissues demonstrate preferential mapping of associated variants to regulatory regions in kidney but not extra-renal tissues. These findings suggest that genetic determinants of eGFR are mediated largely through direct effects within the kidney and highlight important cell types and biological pathways.
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| 3. |
- Callaghan, Terry V., et al.
(författare)
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Changing snow cover and its impacts
- 2011
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Ingår i: Snow, Water, Ice and Permafrost in the Arctic (SWIPA). - Oslo : Arctic Monitoring and Assessment Programme. - 9788279710714 ; , s. 4:1-4:58
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Bokkapitel (refereegranskat)
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| 4. |
- de Peppo, Giuseppe Maria, 1981, et al.
(författare)
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Osteogenic response of human mesenchymal stem cells to well-defined nanoscale topography in vitro
- 2014
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Ingår i: International journal of nanomedicine. - : Informa UK Limited. - 1176-9114 .- 1178-2013. ; 9:1, s. 2499-2515
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Tidskriftsartikel (refereegranskat)abstract
- Background: Patterning medical devices at the nanoscale level enables the manipulation of cell behavior and tissue regeneration, with topographic features recognized as playing a significant role in the osseointegration of implantable devices. Methods: In this study, we assessed the ability of titanium-coated hemisphere-like topographic nanostructures of different sizes (approximately 50, 100, and 200 nm) to influence the morphology, proliferation, and osteogenic differentiation of human mesenchymal stem cells (hMSCs). Results: We found that the proliferation and osteogenic differentiation of hMSCs was influenced by the size of the underlying structures, suggesting that size variations in topographic features at the nanoscale level, independently of chemistry, can be exploited to control hMSC behavior in a size-dependent fashion. Conclusion: Our studies demonstrate that colloidal lithography, in combination with coating technologies, can be exploited to investigate the cell response to well defined nanoscale topography and to develop next-generation surfaces that guide tissue regeneration and promote implant integration.
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| 5. |
- Johansson, Peter, et al.
(författare)
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Increased Risk of Hip Fracture in Patients with Lymphoma, a Swedish Population Study of 37,236 Lymphoma Patients.
- 2020
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Ingår i: Calcified tissue international. - : Springer Science and Business Media LLC. - 1432-0827 .- 0171-967X. ; 106, s. 591-598
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Tidskriftsartikel (refereegranskat)abstract
- Increased bone loss has been noted in lymphoma patients; however, the incidence of hip fracture is not known. The aim of our study was to explore the risk for hip fracture in patients with lymphoma compared with the entire Swedish population. The risk of hip fracture was determined in a retrospective population cohort study of adult Swedish lymphoma patients (n=37,236), diagnosed 1995-2015 and compared with the entire Swedish population during the same period. The incidence of hip fracture in lymphoma patients was higher in women than in men, increased by age, and decreased by calendar year as also demonstrated in the total population. 2.2% of the men and 4.7% of women with lymphoma sustained a hip fracture. For the total group of females, the hazard ratio (HR) was 1.19 (95% CI 1.11-1.28) and for men, the hazard ratio was 1.06 (95% CI 0.97-1.17) compared with the Swedish population. The HR for hip fracture (2016) was 2.80 (95% CI 1.20-6.53), 2.04 (95% CI 1.30-3.20), 1.56 (95% CI 1.21-2.01), 1.08 (95% CI 0.89-1.30), and 1.07 (95% CI 0.92-1.25) in females aged 40, 50, 60, 70, and 80years, respectively. Corresponding figures for men were not significant in 2016. Unmarried men with lymphoma had a two times higher risk for hip fracture (HR 2.02 95% CI 1.63-2.50) compared with married men. Patients with lymphoma had an increased risk of hip fracture, especially younger women and unmarried men. The incidence of hip fracture is decreased by calendar year in the lymphoma patients and the entire Swedish population.
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| 6. |
- Kristjansdottir, Hallgerdur Lind, et al.
(författare)
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High Plasma Erythropoietin Predicts Incident Fractures in Elderly Men with Normal Renal Function : The MrOS Sweden Cohort
- 2020
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Ingår i: Journal of Bone and Mineral Research. - : WILEY. - 0884-0431 .- 1523-4681. ; 35:2, s. 298-305
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Tidskriftsartikel (refereegranskat)abstract
- Preclinical studies on the role of erythropoietin (EPO) in bone metabolism are contradictory. Regeneration models indicate an anabolic effect on bone healing, whereas models on physiologic bone remodeling indicate a catabolic effect on bone mass. No human studies on EPO and fracture risk are available. It is known that fibroblast growth factor 23 (FGF23) affects bone mineralization and that serum concentration of FGF23 is higher in men with decreased estimated glomerular filtration rate (eGFR). Recently, a direct association between EPO and FGF23 has been shown. We have explored the potential association between EPO and bone mineral density (BMD), fracture risk, and FGF23 in humans. Plasma levels of EPO were analyzed in 999 men (aged 69 to 81 years), participating in the Gothenburg part of the population-based Osteoporotic Fractures in Men (MrOS) study, MrOS Sweden. The mean +/- SD EPO was 11.5 +/- 9.0 IU/L. Results were stratified by eGFR 60 mL/min. For men with eGFR >= 60 mL/min (n = 728), EPO was associated with age (r = 0.13, p < 0.001), total hip BMD (r = 0.14, p < 0.001), intact (i)FGF23 (r = 0.11, p = 0.004), and osteocalcin (r = -0.09, p = 0.022). The association between total hip BMD and EPO was independent of age, body mass index (BMI), iFGF23, and hemoglobin (beta = 0.019, p < 0.001). During the 10-year follow-up, 164 men had an X-ray-verified fracture, including 117 major osteoporotic fractures (MOF), 39 hip fractures, and 64 vertebral fractures. High EPO was associated with higher risk for incident fractures (hazard ratio [HR] = 1.43 per tertile EPO, 95% confidence interval [CI] 1.35-1.63), MOF (HR = 1.40 per tertile EPO, 95% CI 1.08-1.82), and vertebral fractures (HR = 1.42 per tertile EPO, 95% CI 1.00-2.01) in a fully adjusted Cox regression model. In men with eGFR<60 mL/min, no association was found between EPO and BMD or fracture risk. We here demonstrate that high levels of EPO are associated with increased fracture risk and increased BMD in elderly men with normal renal function.
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| 7. |
- Lehmuskero, Anni, et al.
(författare)
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Plasmonic particles set into fast orbital motion by an optical vortex beam
- 2014
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Ingår i: Optics express. - : The Optical Society. - 1094-4087. ; 22:4, s. 4349-4356
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Tidskriftsartikel (refereegranskat)abstract
- We optically trap plasmonic gold particles in two dimensions and set them into circular motion around the optical axis using a helically phased vortex laser beam. The orbiting frequency of the particles reaches 86 Hz, which corresponds to a particle velocity of the order 1 mm per second, for an incident laser power of a few tens of milliwatts. The experimentally determined orbiting frequencies are found to be well in line with the notion that the beam carries an orbital angular momentum of ħl per photon.
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| 8. |
- Zengin, Gülis, 1982, et al.
(författare)
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Approaching the strong coupling limit in single plasmonic nanorods interacting with J-aggregates
- 2013
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- We studied scattering and extinction of individual silver nanorods coupled to the J-aggregate form of the cyanine dye TDBC as a function of plasmon - exciton detuning. The measured single particle spectra exhibited a strongly suppressed scattering and extinction rate at wavelengths corresponding to the J-aggregate absorption band, signaling strong interaction between the localized surface plasmon of the metal core and the exciton of the surrounding molecular shell. In the context of strong coupling theory, the observed "transparency dips" correspond to an average vacuum Rabi splitting of the order of 100 meV, which approaches the plasmon dephasing rate and, thereby, the strong coupling limit for the smallest investigated particles. These findings could pave the way towards ultra-strong light-matter interaction on the nanoscale and active plasmonic devices operating at room temperature.
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| 9. |
- Aissaoui, Nesrine, 1983, et al.
(författare)
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FRET enhancement close to gold nanoparticles positioned in DNA origami constructs
- 2017
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Ingår i: Nanoscale. - Cambridge, United Kingdom : Royal Society of Chemistry (RSC). - 2040-3372 .- 2040-3364. ; 9:2, s. 673-683
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Tidskriftsartikel (refereegranskat)abstract
- Here we investigate the energy transfer rates of a Förster resonance energy transfer (FRET) pair positioned in close proximity to a 5 nm gold nanoparticle (AuNP) on a DNA origami construct. We study the distance dependence of the FRET rate by varying the location of the donor molecule, D, relative to the AuNP while maintaining a fixed location of the acceptor molecule, A. The presence of the AuNP induces an alteration in the spontaneous emission of the donor (including radiative and non-radiative rates) which is strongly dependent on the distance between the donor and AuNP surface. Simultaneously, the energy transfer rates are enhanced at shorter D-A (and D-AuNP) distances. Overall, in addition to the direct influence of the acceptor and AuNP on the donor decay there is also a significant increase in decay rate not explained by the sum of the two interactions. This leads to enhanced energy transfer between donor and acceptor in the presence of a 5 nm AuNP. We also demonstrate that the transfer rate in the three "particle" geometry (D + A + AuNP) depends approximately linearly on the transfer rate in the donor-AuNP system, suggesting the possibility to control FRET process with electric field induced by 5 nm AuNPs close to the donor fluorophore. It is concluded that DNA origami is a very versatile platform for studying interactions between molecules and plasmonic nanoparticles in general and FRET enhancement in particular.
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| 10. |
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| 11. |
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| 12. |
- Andersson, Marcus, 1975, et al.
(författare)
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Effect of molecular mobility of polymeric implants on soft tissue reactions: An in vivo study in rats
- 2008
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Ingår i: Journal of Biomedical Materials Research Part A. - : Wiley. - 1552-4965 .- 1549-3296. ; 84A:3, s. 652-660
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Tidskriftsartikel (refereegranskat)abstract
- Although numerous different polymers are used as implants or otherwise studied for many other biotechnical applications, there is a lack of basic models that correlate polymer characteristics with foreign body reactions. This study aims at developing one such model by systematically studying surface molecular mobility of polymeric implants in soft tissues in vivo. Changing the length of the alkyl side chain of poly(alkyl methacrylates) (PAMAs), provides an interesting opportunity to study the surface molecular mobility with minimal changes of the hydrophobicity of the surface. Thus, in this study three different PAMAs, with increasingly surface mobility; poly (isobutyl methacrylate) (PIBMA), poly(butyl methacrylate) (PBMA), and poly(lauryl methacralate) (PLMA) along with pure titanium (Ti) substrates were implanted in the dorsum of Sprague-Dawley rats. Inflammatory cell recruitment, cell adhesion, and cytokine release were studied after 1, 3, and 28 days of implantation. Total number of inflammatory cells in the exudate was measured but no correlation between surface mobility and cell recruitment where found. However, the number of surface associated cells where significantly lower on the surfaces with high molecular mobility (PLMA and PBMA). The histological evaluation performed after 28 days revealed thicker fibrous capsule and a higher number of blood vessels on the low molecular mobility surface (PIBMA). After 28 days the cell activity was higher on the high molecular mobility surfaces (PLMA and PBMA) compared with PIBMA, based on the cytokine release. None of the surfaces induced any significant cell-death. On the basis of the results of this study we conclude that there is a significant difference in biological response to surfaces with different in molecular mobility. This might affect the wound healing process and the biocompatibility of biomaterials. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007 -------------------------------------------------------------------------------- Received: 13 March 2006; Revised: 15 December 2006; Accepted: 29 January 2007 Digital Object Identifier (DOI) 10.1002/jbm.a.31389 About DOI
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| 13. |
- Andrén, Daniel, 1991, et al.
(författare)
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Probing Photothermal Effects on Optically Trapped Gold Nanorods by Simultaneous Plasmon Spectroscopy and Brownian Dynamics Analysis
- 2017
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 11:10, s. 10053-10061
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Tidskriftsartikel (refereegranskat)abstract
- Plasmonic gold nanorods are prime candidates for a variety of biomedical, spectroscopy, data storage, and sensing applications. It was recently shown that gold nanorods optically trapped by a focused circularly polarized laser beam can function as extremely efficient nanoscopic rotary motors. The system holds promise for-applications ranging from nanofluidic flow control and nanorobotics to biomolecular actuation and analysis. However, to fully exploit this potential, one needs to be able to control and understand heating effects associated with laser trapping. We investigated photothermal heating of individual rotating gold nanorods by simultaneously probing their localized surface plasmon resonance spectrum and rotational Brownian dynamics over extended periods of time. The data reveal an extremely slow nanoparticle reshaping process, involving migration of the order of a few hundred atoms per minute, for moderate laser powers and a trapping wavelength close to plasmon resonance. The plasmon spectroscopy and Brownian analysis allows for separate temperature estimates based on the refractive index and the viscosity of the water surrounding a trapped nanorod. We show that both measurements yield similar effective temperatures, which correspond to the actual temperature at a distance of the order 10-15 nm from the particle surface. Our results shed light on photothermal processes on the nanoscale and will be useful in evaluating the applicability and performance of nanorod motors and optically heated nanoparticles for a variety of applications.
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| 14. |
- Andrén, Daniel, 1991, et al.
(författare)
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Surface Interactions of Gold Nanoparticles Optically Trapped against an Interface
- 2019
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Ingår i: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 123:26, s. 16406-16414
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Tidskriftsartikel (refereegranskat)abstract
- Particles that diffuse in close proximity to a surface are expected to behave differently than in free solution because the surface interaction will influence a number of physical properties, including the hydrodynamic, optical, and thermal characteristics of the particle. Understanding the influence of such effects is particularly important in view of the increasing interest in laser tweezing of colloidal resonant nanoparticles for applications such as nanomotors and optical printing and for investigations of unconventional optical forces. Therefore, we used total internal reflection microscopy to probe the interaction between a glass surface and individual ∼100 nm gold nanoparticles trapped by laser tweezers. The results show that particles can be optically confined at controllable distances ranging between ∼30 and ∼90 nm from the surface, depending on the radiation pressure of the trapping laser and the ionic screening of the surrounding liquid. Moreover, the full particle-surface distance probability distribution can be obtained for single nanoparticles by analyzing temporal signal fluctuations. The experimental results are in excellent agreement with Brownian dynamics simulations that take the full force field and photothermal heating into account. At the observed particle-surface distances, translational friction coefficients increase by up to 60% compared to freely diffusing particles, whereas the rotational friction and thermal dissipation are much less affected. The methodology used here is general and can be adapted to a range of single nanoparticle-surface interaction investigations.
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| 15. |
- Ben Amara, Heithem, 1984, et al.
(författare)
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Immunomodulation by biodegradable Mg-implants promotes soft and hard tissues responses in vivo
- 2023
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Ingår i: Scandinavian Society of Biomaterials conference, 21–24 March 2023, Røros, Norway.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- INTRODUCTION: Magnesium (Mg)-based degradable implants are an attractive treatment solution for musculoskeletal injuries, avoiding second-stage surgical removal. In multiple clinical applications, the implant is in contact with both the bone and the overlying soft tissue. Although Mg implants are often presented to hold anti-inflammatory properties, less attention has been paid to the sequential response to these implants including initial immune response and subsequent tissue repair. The present study investigated the molecular, cellular, and structural events taking place at the Mg implant interface to soft tissue and bone after in vivo implantation in dedicated experimental rat models. METHODS: Male Sprague Dawley rats received disc-shaped implants in the dorsum subcutis or screw-shaped implants in the proximal tibial metaphysis. Implants were manufactured from pure magnesium (99.99% - high purity; Mg) or from pure titanium (grade 4; Ti) as control. Animals were euthanized after 1, 3, 6, 14, and 28 day of soft tissue implantation, and after 3 and 28 days of bone implantation. Two types of samples were collected: 1-Implants with the adherent cells (n=7-8/group/time-point). These were allocated for cell counting and /or gene expression analyses of implant-adherent cells. 2-Peri-implant tissue with implants (n = 8/group/time-point). These enabled histological and histomorphometric analyses of the fibrous capsule organization around implants inserted in soft tissues and of osseointegration parameters at the bone-implant interface. Statistical comparisons between experimental groups were run using Kruskal-Wallis, and Mann-Whitney tests (p<0.05). RESULTS: Cells adherent to the surface of the implants featured different gene regulation patterns between Mg and Ti groups (Fig. 1). Consistently in soft tissue and in bone, macrophage polarization markers indicated higher expression of proinflammatory macrophage gene inducible nitric oxide synthase (iNos) initially at Mg versus Ti (3 d in bone and 1-6 d in soft tissue). Afterward, gene expression of both macrophage subtypes markers (proinflammatory – iNos and prohealing – Mannose receptor c1; Mrc1) was comparable between implants, irrespective of their insertion site. Histomorphometry evidenced superior bone-implant contact (at 28 d in bone) and thinner fibrous capsule (at 6-28 d in soft tissue) for Mg versus Ti. CONCLUSIONS: In comparison to non-degradable Ti, both soft tissue and bone responses to biodegradable Mg featured an initial yet transient gene activation of the macrophage proinflammatory subtype. Such immunomodulation by Mg resulted in the reduction of fibrous encapsulation in soft tissue and in the promotion of bone formation at the bone-implant interface. ACKNOWLEDGEMENTS: Mg implants were generously provided by Helmholtz-Zentrum Hereon, Geesthacht, Germany. This project is part of the European Training Network within the framework of Horizon 2020 Marie Skłodowska-Curie Action No 811226.
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| 16. |
- Ben Amara, Heithem, 1984, et al.
(författare)
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In vivo interaction between biodegradable magnesium implants and soft tissue Part II: Kinetics of the cellular response at the host-implant interface
- 2021
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Ingår i: 13th Biometal Conference, 23-26 August 2021, Virtual Conference..
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- INTRODUCTION: Regenerative therapies often engage multiple tissues. Soft tissue complications (e.g. dehiscences and infection) may violate successful bone regeneration. Magnesium (Mg)-based degradable implants is a promising treatment alternative for musculoskeletal injuries, avoiding second-stage surgical removal. In several clinical applications, the implant is in contact with both the bone and the overlying soft tissue. Whereas the bone response to Mg implants has been a major research focus, less attention has been paid to the soft tissue response. The present study investigated the spatial and temporal molecular, cellular and structural events taking place at the soft tissue-Mg implant interface after in vivo implantation in an experimental rat model. METHODS: Following approval by the Local Ethical Committee at the University of Gothenburg (Dnr 02437/2018), female Sprague-Dawley rats (n=90) were implanted with discs manufactured from pure magnesium (99.99% - high purity; Mg) or from pure titanium (grade 4; Ti) (herein, employed as a control, possessing biocompatibility properties). Subcutaneous pockets were surgically created in the animal dorsum and were implanted with: 1- Ti; or 2- Mg discs; or 3- left without implants (Sham Ti or Sham Mg). After 1, 3, 6, 14 and 28 days, animals were euthanized, and three types of samples were retrieved: 1-Implants with the adherent cells (n=8/group/time-point): for cell counting and molecular gene expression of the implant-adherent cells. 2-Peri-implant exudate (n=8/group/time-point): for analyses of the number, type, viability, and gene expression of cells in the peri-implant space. 3-Peri-implant tissue with implants (n=8/group/time-point): enabling histological and histomorphometric analyses of soft tissue and fibrous capsule organization around the implant. Statistical comparisons were made between experimental groups at each time point and between time-points for each experimental group. (Kruskal-Wallis, Mann-Whitney and Wilcoxon signed-rank tests; p<0.05). RESULTS: Cells recruited to the exudates and adherent to the surface of the implants featured different kinetics between Mg and Ti groups. At the surface of Mg implant, the number of adherent cells sharply increased from 1 day to reach a peak at 6 days, thereafter decreasing toward 28 days. The ratio of implant-adherent/exudate cells was significantly higher at Mg vs Ti after 6 days, whereas the reverse was detected after 28 days. RNA extracted from cells from the different compartments revealed good quality, allowing detailed molecular analysis. After 28d, the fibrous capsule around Mg implants was significantly thinner than around Ti. CONCLUSIONS: In comparison to non-degradable Ti controls, soft tissue healing around biodegradable Mg implants is characterized by an early, intense, but yet transient, cellular influx in the immediate vicinity of the implant surface, and, at later stage, with a reduced fibrotic encapsulation. ACKNOWLEDGEMENTS: Mg implants were generously provided by the Helmholtz-Zentrum Hereon, Geesthacht, Germany. This project is part of the European Training Network within the framework of Horizon 2020 Marie Skodowska-Curie Action No 811226.
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| 17. |
- Ben Amara, Heithem, 1984, et al.
(författare)
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Magnesium implant degradation provides immunomodulatory and proangiogenic effects and attenuates peri-implant fibrosis in soft tissues
- 2023
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Ingår i: Bioactive Materials. - : Elsevier BV. - 2452-199X. ; 26, s. 353-369
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Tidskriftsartikel (refereegranskat)abstract
- Implants made of magnesium (Mg) are increasingly employed in patients to achieve osteosynthesis while degrading in situ. Since Mg implants and Mg2+ have been suggested to possess anti-inflammatory properties, the clinically observed soft tissue inflammation around Mg implants is enigmatic. Here, using a rat soft tissue model and a 1-28 d observation period, we determined the temporo-spatial cell distribution and behavior in relation to sequential changes of pure Mg implant surface properties and Mg2+ release. Compared to nondegradable titanium (Ti) implants, Mg degradation exacerbated initial inflammation. Release of Mg degradation products at the tissue-implant interface, culminating at 3 d, actively initiated chemotaxis and upregulated mRNA and protein immunomodulatory markers, particularly inducible nitric oxide synthase and toll-like receptor-4 up to 6 d, yet without a cytotoxic effect. Increased vascularization was demonstrated morphologically, preceded by high expression of vascular endothelial growth factor. The transition to appropriate tissue repair coincided with implant surface enrichment of Ca and P and reduced peri-implant Mg2+ concentration. Mg implants revealed a thinner fibrous encapsulation compared with Ti. The detailed understanding of the relationship between Mg material properties and the spatial and time-resolved cellular processes provides a basis for the interpretation of clinical observations and future tailoring of Mg implants.
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| 18. |
- Ben Amara, Heithem, 1984, et al.
(författare)
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Promoting soft and hard tissue repair via immunomodulation by the surface degradation of magnesium implants in vivo
- 2023
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Ingår i: Materials for Tomorrow conference by Chalmers University of Technology, 8-10 November 2023, Gothenburg, Sweden.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- INTRODUCTION: Magnesium (Mg) is a reactive metallic biomaterial that degrades via surface corrosion upon contact with body fluids. By virtue of its degradation and mechanical properties, Mg implants are currently employed with success to treat musculoskeletal injuries and avoid second-stage surgical removal 1. While these implants are claimed to possess anti-inflammatory properties, this notion contrasts with the initial signs of inflammation observed in the soft tissue of patients treated with Mg implants. This study investigated how the surface degradation of Mg implants in vivo influences the molecular, cellular, and structural events during initial inflammation and subsequent healing of the interfacing soft tissue and bone in comparison to nondegradable titanium (Ti) implants using experimental rat models. METHODS: Rats received disc-shaped implants in their dorsum subcutis or screw-shaped implants in the proximal metaphysis of their tibiae. Implants were manufactured from pure Mg (>99.995% - high purity) or from pure Ti (grade 4). Animals were euthanized after 1, 3, 6, 14, and 28 days of soft tissue implantation, and after 3 and 28 days of bone implantation. Two types of samples were collected: i) Implants only (n = 7-8/group/time-point): for counting and/or gene expression analyses of implant-adherent cells. ii) Implants with peri-implant tissues (n = 5-8/group/time-point): for compositional analysis of the Mg degradation layer in conjunction with the histomorphometry of the fibrous capsule around implants in soft tissues and of osseointegration at the bone–implant interface. Statistical comparisons were run using Kruskal-Wallis and Mann-Whitney tests (p<0.05). RESULTS: Cells adherent to the implant surfaces featured different gene regulation patterns between Mg and Ti groups (Fig. 1). Initially in soft tissue (1–6 d) and bone (3 d), a higher expression of proinflammatory macrophage polarization markers, e.g. inducible nitric oxide synthase (iNos), was shown in Mg versus Ti groups. Afterward, by 28 d, gene expression of both macrophage subtype markers (proinflammatory – iNos, and prohealing – Mannose receptor c1; Mrc1) was comparable between implants, irrespective of their insertion site. Histomorphometry revealed superior bone–implant contact (at 28 d in bone) and thinner fibrous capsule (at 6–28 d in soft tissue) for Mg versus Ti (Fig. 1). The 28 d-degradation layer at the Mg surface was enriched in Ca and P in both soft tissue and bone. CONCLUSIONS: In comparison to Ti implants, both soft tissue and bone responses to Mg implants featured an initial, amplified, yet transient, inflammation marked by the gene activation of the macrophage proinflammatory subtype. Such immunomodulation by the surface degradation of Mg implant promoted more bone deposition, at the bone–implant interface, and less fibrous encapsulation, at the soft tissue–implant interface. REFERENCES: 1. Han et al. Mater Today 2019, 23: 57-71. ACKNOWLEDGEMENTS: Horizon 2020 Marie Skłodowska-Curie Action (No 811226) and Area of Advance Materials/Chalmers and GU Biomaterials. Mg implants were generously provided by Hereon, Geesthacht, Germany.
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| 19. |
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| 20. |
- Callaghan, Terry V., et al.
(författare)
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Multiple Effects of Changes in Arctic Snow Cover
- 2011
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Ingår i: Ambio: a Journal of Human Environment. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 40, s. 32-45
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Tidskriftsartikel (refereegranskat)abstract
- Snow cover plays a major role in the climate, hydrological and ecological systems of the Arctic and other regions through its influence on the surface energy balance (e.g. reflectivity), water balance (e.g. water storage and release), thermal regimes (e.g. insulation), vegetation and trace gas fluxes. Feedbacks to the climate system have global consequences. The livelihoods and well-being of Arctic residents and many services for the wider population depend on snow conditions so changes have important consequences. Already, changing snow conditions, particularly reduced summer soil moisture, winter thaw events and rain-on-snow conditions have negatively affected commercial forestry, reindeer herding, some wild animal populations and vegetation. Reductions in snow cover are also adversely impacting indigenous peoples' access to traditional foods with negative impacts on human health and well-being. However, there are likely to be some benefits from a changing Arctic snow regime such as more even run-off from melting snow that favours hydropower operations.
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| 21. |
- Carlred, Louise M, 1985, et al.
(författare)
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Imaging of Amyloid-β in Alzheimer’s disease transgenic mouse brains with Time-of-Flight Secondary Ion Mass Spectrometry using Immunoliposomes
- 2016
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Ingår i: Biointerphases. - : American Vacuum Society. - 1559-4106 .- 1934-8630. ; 11:2, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been proven to successfully image different kinds of molecules, especially a variety of lipids, in biological samples. Proteins, however, are difficult to detect as specific entities with this method due to extensive fragmentation. To circumvent this issue, the authors present in this work a method developed for detection of proteins using antibody-conjugated liposomes, so called immunoliposomes, which are able to bind to the specific protein of interest. In combination with the capability of ToF-SIMS to detect native lipids in tissue samples, this method opens up the opportunity to analyze many different biomolecules, both lipids and proteins, at the same time, with high spatial resolution. The method has been applied to detect and image the distribution of amyloid-β (Aβ), a biologically relevant peptide in Alzheimer's disease (AD), in transgenic mouse braintissue. To ensure specific binding, the immunoliposome binding was verified on a model surface using quartz crystal microbalance with dissipation monitoring. The immunoliposome binding was also investigated on tissue sections with fluorescence microscopy, and compared with conventional immunohistochemistry using primary and secondary antibodies, demonstrating specific binding to Aβ. Using ToF-SIMS imaging, several endogenous lipids, such as cholesterol and sulfatides, were also detected in parallel with the immunoliposome-labeled Aβ deposits, which is an advantage compared to fluorescence microscopy. This method can thus potentially provide further information about lipid–protein interactions, which is important to understand the mechanisms of neurodegeneration in AD.
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| 22. |
- Carlred, Louise M, 1985, et al.
(författare)
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Simultaneous imaging of amyloid-β and lipids in brain tissue using antibody-coupled liposomes and time-of-flight secondary ion mass spectrometry
- 2014
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 136:28, s. 9973-9981
-
Tidskriftsartikel (refereegranskat)abstract
- The spatial localization of amyloid-β peptide deposits, the major component of senile plaques in Alzheimer's disease (AD), was mapped in transgenic AD mouse brains using time-of-flight secondary ion mass spectrometry (ToF-SIMS), simultaneously with several endogenous molecules that cannot be mapped using conventional immunohistochemistry imaging, including phospholipids, cholesterol and sulfatides. Whereas the endogenous lipids were detected directly, the amyloid-β deposits, which cannot be detected as intact entities with ToF-SIMS because of extensive ion-induced fragmentation, were identified by specific binding of deuterated liposomes to antibodies directed against amyloid-β. Comparative investigation of the amyloid-β deposits using conventional immunohistochemistry and fluorescence microscopy suggests similar sensitivity but a more surface-confined identification due to the shallow penetration depth of the ToF-SIMS signal. The recorded ToF-SIMS images thus display the localization of lipids and amyloid-β in a narrow (∼10 nm) two-dimensional plane at the tissue surface. As compared to a frozen nontreated tissue sample, the liposome preparation protocol generally increased the signal intensity of endogenous lipids, likely caused by matrix effects associated with the removal of salts, but no severe effects on the tissue integrity and the spatial distribution of lipids were observed with ToF-SIMS or scanning electron microscopy (SEM). This method may provide an important extension to conventional tissue imaging techniques to investigate the complex interplay of different kinds of molecules in neurodegenerative diseases, in the same specimen. However, limitations in target accessibility of the liposomes as well as unspecific binding need further consideration. © 2014 American Chemical Society.
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| 23. |
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| 24. |
- Cui, Ximin, 1991, et al.
(författare)
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Synchronization of optically self-assembled nanorotors
- 2024
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 10:10
-
Tidskriftsartikel (refereegranskat)abstract
- Self-assembly of nanoparticles by means of interparticle optical forces provides a compelling approach toward contact-free organization and manipulation of nanoscale entities. However, exploration of the rotational degrees of freedom in this process has remained limited, primarily because of the predominant focus on spherical nanoparticles, for which individual particle orientation cannot be determined. Here, we show that gold nanorods, which self-assemble in water under the influence of circularly polarized light, exhibit synchronized rotational motion at kilohertz frequencies. The synchronization is caused by strong optical interactions and occurs despite the presence of thermal diffusion. Our findings elucidate the intricate dynamics arising from the transfer of photon spin angular momentum to optically bound matter and hold promise for advancing the emerging field of light-driven nanomachinery.
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| 25. |
- Finnveden, Maja, 1986-, et al.
(författare)
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Lipase-Catalyzed Synthesis of Renewable Plant Oil-Based Polyamides.
- 2019
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Ingår i: Polymers. - : MDPI. - 2073-4360. ; 11:11
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Tidskriftsartikel (refereegranskat)abstract
- Enzyme catalyzed synthesis of renewable polyamides was investigated using Candida antarctica lipase B. A fatty acid-derived AB-type functional monomer, having one amine and one methyl ester functionality, was homopolymerized at 80 and 140 °C. Additionally, the organobase 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) was used as a catalyst. The results from the two catalysts were comparable. However, the amount of lipase added was 1.2 × 103 times lower, showing that the lipase was a more efficient catalyst for this system as compared to TBD. Moreover, the AB-type monomer was copolymerized with 1,12-diaminododecane to synthesize oligoamides of two different lengths.
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| 26. |
- Finnveden, Maja, 1986-, et al.
(författare)
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Lipase Catalyzed Synthesis of renewable plant oil-based polyamides
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Enzyme catalyzed synthesis towards renewable polyamides was investigated using Candida antarctica lipase B. A fatty acid-derived AB-type functional monomer, having one amine and one methyl ester functionality was homopolymerized at 80 and 140°C. Additionally, the organobase 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) was used as catalyst. The results from the two catalysts were comparable. However, the amount of lipase added was 1200 times lower showing that the lipase was a more efficient catalyst for this system as compared to TBD. Moreover, the AB type monomer was copolymerized with 1,12-diaminododecan to synthesize oligoamides of two different lengths.
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| 27. |
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| 28. |
- Hagberg, Peter, et al.
(författare)
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Styrkor och färdigheter som möjligheter i utbildning och arbete för unga omsorgsgivare med minoritets- och utländsk bakgrund
- 2017. - 1
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Ingår i: Tearing down barriers to employment & education. - London : IARS Publications. - 9781907641428 ; , s. 105-124
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Nationellt kompetenscentrum anhöriga (Nka), som är en del av Linnéuniversitetet, är en av aktörerna i det nationella utvecklingsuppdraget kring barn som anhöriga, som Socialstyrelsen är huvudman för (www.anhoriga.se). Nka arbetar som ett expertstöd för praktiker, beslutsfattare och andra aktörer inom området barn som anhöriga. Nka har ingått som ett av partnerländerna inom det Erasmus+ (KA2 Youth) finansierade projektet Care2Work tillsammans med the IARS International Institute (Storbritannien, projektkoordinator), the Family and ChildrenCare Centre (KMOP, Grekland) och Anziani e Non Solo (Italien). Projektet Care2Work handlar om unga omsorgsgivare med minoritets- och utländsk bakgrund inom Europa, och de hinder och möjligheter de kan uppleva inför framtida utbildning, träning och arbete (www.care2work.org). Under projekttiden har vi undersökt hur ett utbildningsstöd för unga omsorgsgivare (15-29 år) med minoritets- och utländsk bakgrund skulle kunna utformas. Utöver det har en kartläggning av befintliga verksamheter och utbildnings- eller stödfunktioner som direkt eller indirekt riktar sig till målgruppen genomförts.Den här rapporten är en sammanställning av de lärdomar och reflektioner som vuxit fram under projekttiden. Vi har inte funnit någon forskning i Sverige som direkt belyser den här gruppen utan har istället använt oss av forskning där målgruppen indirekt är berörd tillsammans med de studier vi själva genomfört. Det här gör det än viktigare att lärdomar från projektet används som material i utformandet av stöd till unga omsorgsgivare samt vägledning i de kunskapsluckor som finns inom området. Under projekttiden har de deltagande länderna bidragit i skapandet av en interaktiv webbplattform som innehåller utbildningsverktyg, hjälpmedel, bloggar, projektuppdateringar, events och nyheter. Webbplatsen (www.care2work.org) är speciellt designad för en bred målgrupp som inkluderar unga omsorgsgivare, ungdomsledare, forskare, akademiker, beslutsfattare och arbetsgivare. Den nya webbplattformen syftar till att öka medvetenheten om behoven hos unga omsorgsgivare och skapar en mötesplats för kreativa debatter bland olika berörda parter. Webbsidan erbjuder även en rad innovativa utbildningsverktyg, som riktar sig till både unga omsorgsgivare och professionella, och kan användas för att höja och framhäva unga omsorgsgivares kompetens och kunskap som de förvärvat genom anhörigomsorg och därmed ökat deras utbildningsmöjlighet och anställningsbarhet.
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| 29. |
- Hajizadeh Chavari, Faegheh, 1982, et al.
(författare)
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Brownian fluctuations of an optically rotated nanorod
- 2017
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Ingår i: Optica. - : The Optical Society. - 2334-2536. ; 4:7, s. 746-751
-
Tidskriftsartikel (refereegranskat)abstract
- Gold nanorods can be optically trapped in aqueous solution and forced to rotate at kilohertz rates by circularly polarized laser light. This enables detailed investigations of local environmental parameters and processes, such as medium viscosity and nanoparticle-molecule reactions. Future applications may include nanoactuation and single-cell analysis. However, the influence of photothermal heating on the nanoparticle dynamics needs to be better understood in order to realize widespread and quantitative use. Here we analyze the hot Brownian motion of a rotating gold nanorod trapped in two dimensions by an optical tweezers using experiments and stochastic simulations. We show that, for typical settings, the effective rotational and translational Brownian temperatures are drastically different, being closer to the nanorod surface temperature and ambient temperature, respectively. Further, we show that translational dynamics can have a non-negligible influence on the rotational fluctuations due to the small size of a nanorod in comparison to the focal spot. These results are crucial for the development of gold nanorods into generic and quantitative optomechanical sensor and actuator elements.
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| 30. |
- Hajizadeh, Faegheh, et al.
(författare)
-
Brownian fluctuations of an optically rotated nanorod
- 2017
-
Ingår i: Optica. - : Optics Info Base, Optical Society of America. - 2334-2536. ; 4:7, s. 746-751
-
Tidskriftsartikel (refereegranskat)abstract
- Gold nanorods can be optically trapped in aqueous solution and forced to rotate at kilohertz rates by circularly polarized laser light. This enables detailed investigations of local environmental parameters and processes, such as medium viscosity and nanoparticle-molecule reactions. Future applications may include nanoactuation and single-cell analysis. However, the influence of photothermal heating on the nanoparticle dynamics needs to be better understood in order to realize widespread and quantitative use. Here we analyze the hot Brownian motion of a rotating gold nanorod trapped in two dimensions by an optical tweezers using experiments and stochastic simulations. We show that, for typical settings, the effective rotational and translational Brownian temperatures are drastically different, being closer to the nanorod surface temperature and ambient temperature, respectively. Further, we show that translational dynamics can have a non-negligible influence on the rotational fluctuations due to the small size of a nanorod in comparison to the focal spot. These results are crucial for the development of gold nanorods into generic and quantitative optomechanical sensor and actuator elements. (C) 2017 Optical Society of America
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| 31. |
- Jacobson, Sofie, 1961-, et al.
(författare)
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Levels of mannose-binding lectin (MBL) associates with sepsis-related in-hospital mortality in women
- 2020
-
Ingår i: Journal of Inflammation. - : BioMed Central (BMC). - 1476-9255. ; 17
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Mannose-binding lectin (MBL) mediates the innate immune response either through direct opsonisation of microorganisms or through activation of the complement system. There are conflicting data whether MBL deficiency leads to increased susceptibility to infections or not. The aim of this study was to determine if low levels of mannose-binding lectin (MBL) predict sepsis development, sepsis severity and outcome from severe sepsis or septic shock.Method: Patients aged 18 years or more with documented sepsis within 24 h after admission to the intensive care unit were included if they had participated in a health survey and donated blood samples prior to the sepsis event. A subset of these patients had stored plasma also from the acute phase. Two matched referents free of known sepsis were selected for each case. Plasma levels MBL were determined in stored samples from health surveys (baseline) and from ICU admission (acute phase). The association between MBL and sepsis, sepsis severity and in-hospital mortality were determined with 1300 ng/mL as cut-off for low levels.Results: We identified 148 patients (61.5% women) with a first-time sepsis event 6.5 years (median with IQR 7.7) after participation in a health survey, of which 122 also had samples from the acute septic phase. Both high MBL levels in the acute phase (odds ratio [95% confidence interval]) (2.84 [1.20-6.26]), and an increase in MBL levels from baseline to the acute phase (3.76 [1.21-11.72]) were associated with increased risk for in-hospital death in women, but not in men (0.47 [0.11-2.06]). Baseline MBL levels did not predict future sepsis, sepsis severity or in-hospital mortality.Conclusions: An increase from baseline to the acute phase as well as high levels in the acute phase associated with an unfavourable outcome in women.
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| 32. |
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| 33. |
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| 34. |
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| 35. |
- Johansson, Magnus C, 1954, et al.
(författare)
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The influence of patent foramen ovale on oxygen desaturation in obstructive sleep apnoea
- 2007
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Ingår i: The European respiratory journal. - : European Respiratory Society (ERS). - 0903-1936 .- 0903-1936 .- 1399-3003. ; 29:1, s. 149-55
-
Tidskriftsartikel (refereegranskat)abstract
- Obstructive sleep apnoea (OSA) is associated with oxygen desaturation to a varying degree. A patent foramen ovale (PFO) may allow interatrial right-to-left shunting. The hypothesis of the current study was that oxygen desaturation will occur more often, in proportion to the frequency of respiratory disturbances, in OSA subjects with PFO than in those without. In a group of 209 subjects diagnosed with OSA, the proportion of desaturation to respiratory events was calculated as the ratio of oxygen desaturation index (ODI)/apnoea-hypopnoea index (AHI). A total of 15 cases with high proportional desaturation (ODI/AHI >or=0.66) were individually matched with 15 controls with low proportional desaturation (ODI/AHI or=20 bubbles passed over from the right to the left atrium after a single injection. The prevalence of large PFO was nine out of 15 (60%) in the high proportional desaturation group versus two out of 15 (13%) in the low proportional desaturation group. The median number of passing bubbles was positively correlated to minimum oxygen saturation among those with PFO. In conclusion, oxygen desaturation occurs more often, in proportion to the frequency of respiratory disturbances, in obstructive sleep apnoea subjects with a patent foramen ovale than in those without.
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| 36. |
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| 37. |
- Johansson, Peter, 1961
(författare)
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Electromagnetic Green's function for layered systems: Applications to nanohole interactions in thin metal films
- 2011
-
Ingår i: Physical Review B - Condensed Matter and Materials Physics. - 2469-9950 .- 2469-9969 .- 1098-0121 .- 1550-235X. ; 83:19
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Tidskriftsartikel (refereegranskat)abstract
- We derive expressions for the electromagnetic Green's function for a layered system using a transfer matrix technique. The expressions we arrive at make it possible to study symmetry properties of the Green's function, such as reciprocity symmetry, and the long-range properties of the Green's function which involves plasmon waves as well as boundary waves, also known as Norton waves. We apply the method by calculating the light-scattering cross section off a chain of nanoholes in a thin Au film. The results highlight the importance of nanohole interactions mediated by surface plasmon propagating along the chain of holes.
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| 38. |
- Johansson, Peter, 1961, et al.
(författare)
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Surface-enhanced Raman scattering and fluorescence near metal nanoparticles
- 2005
-
Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 72, s. 035427-
-
Tidskriftsartikel (refereegranskat)abstract
- We present a general model study of surface-enhanced resonant Raman scattering and fluorescence, focusing on the interplay between electromagnetic (EM) effects and the molecular dynamics as treated by a density matrix calculation. The model molecule has two electronic levels, is affected by radiative and nonradiative damping mechanisms, and a Franck-Condon mechanism yields electron-vibration coupling. The coupling between the molecule and the electromagnetic field is enhanced by placing it between two Ag nanoparticles. The results show that the Raman scattering cross section can, for realistic parameter values, increase by some 10 orders of magnitude (to similar to 10(-14) cm(2)) compared with the free-space case. Also the fluorescence cross section grows with increasing EM enhancement, however, at a slower rate, and this increase eventually stalls when nonradiative decay processes become important. Finally, we find that anti-Stokes Raman scattering is possible with strong incident laser intensities similar to 1 mW/mu m(2).
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| 39. |
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| 40. |
- Karazisis, Dimitrios, 1977, et al.
(författare)
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The effects of controlled nanotopography, machined topography and their combination on molecular activities, bone formation and biomechanical stability during osseointegration
- 2021
-
Ingår i: Acta Biomaterialia. - : Elsevier BV. - 1742-7061 .- 1878-7568. ; 136, s. 279-290
-
Tidskriftsartikel (refereegranskat)abstract
- The initial cellular and molecular activities at the bone interface of implants with controlled nanoscale topography and microscale roughness have previously been reported. However, the effects of such surface modifications on the development of osseointegration have not yet been determined. This study investigated the molecular events and the histological and biomechanical development of the bone interface in implants with nanoscale topography, microscale roughness or a combination of both. Polished and machined titanium implants with and without controlled nanopatterning (75 nm protrusions) were produced using colloidal lithography and coated with a thin titanium layer to unify the chemistry. The implants were inserted in rat tibiae and subjected to removal torque (RTQ) measurements, molecular analyses and histological analyses after 6, 21 and 28 days. The results showed that nanotopography superimposed on microrough, machined, surfaces promoted an early increase in RTQ and hence produced greater implant stability at 6 and 21 days. Two-way MANOVA revealed that the increased RTQ was influenced by microscale roughness and the combination of nanoscale and microscale topographies. Furthermore, increased bone-implant contact (BIC) was observed with the combined nanopatterned machined surface, although MANOVA results implied that the increased BIC was mainly dependent on microscale roughness. At the molecular level, the nanotopography, per se, and in synergy with microscale roughness, downregulated the expression of the proinflammatory cytokine tumor necrosis factor alpha (TNF-α). In conclusion, controlled nanotopography superimposed on microrough machined implants promoted implant stability during osseointegration. Nanoscale-driven mechanisms may involve attenuation of the inflammatory response at the titanium implant site. Statement of Significance: The role of combined implant microscale and nanotopography features for osseointegration is incompletely understood. Using colloidal lithography technique, we created an ordered nanotopography pattern superimposed on screwshaped implants with microscale topography. The midterm and late molecular, bone-implant contact and removal torque responses were analysed in vivo. Nanotopography superimposed on microrough, machined, surfaces promoted the implant stability, influenced by microscale topography and the combination of nanoscale and microscale topographies. Increased bone-implant contact was mainly dependent on microscale roughness whereas the nanotopography, per se, and in synergy with microscale roughness, attenuated the proinflammatory tumor necrosis factor alpha (TNF-α) expression. It is concluded that microscale and nanopatterns provide individual as well as synergistic effects on molecular, morphological and biomechanical implant-tissue processes in vivo.
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| 41. |
- Karazisis, Dimitrios, 1977, et al.
(författare)
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The influence of controlled surface nanotopography on the early biological events of osseointegration
- 2017
-
Ingår i: Acta Biomaterialia. - : Elsevier BV. - 1742-7061 .- 1878-7568. ; 53, s. 559-571
-
Tidskriftsartikel (refereegranskat)abstract
- The early cell and tissue interactions with nanopatterned titanium implants are insufficiently described in vivo. A limitation has been to transfer a pre-determined, well-controlled nanotopography to 3D titanium implants, without affecting other surface parameters, including surface microtopography and chemistry. This in vivo study aimed to investigate the early cellular and molecular events at the bone interface with screw-shaped titanium implants superimposed with controlled nanotopography. Polished and machined titanium implants were firstly patterned with 75-nm semispherical protrusions. Polished and machined implants without nano-patterns were designated as controls. Thereafter, all nanopatterned and control implants were sputter-coated with a 30 nm titanium layer to unify the surface chemistry. The implants were inserted in rat tibiae and samples were harvested after 12 h,1 d and 3 d. In one group, the implants were unscrewed and the implant-adherent cells were analyzed using quantitative polymerase chain reaction. In another group, implants with surrounding bone were harvested en bloc for histology and immunohistochemistry. The results showed that nanotopography downregulated the expression of monocyte chemoattractant protein-1 (MCP-1), at 1 d, and triggered the expression of osteocalcin (DC) at 3 d. This was in parallel with a relatively lower number of recruited CD68-positive macrophages in the tissue surrounding the nanopatterned implants. Moreover, a higher proportion of newly formed osteoid and woven bone was found at the nanopatterned implants at 3 d. It is concluded that nanotopography, per se, attenuates the inflammatory process and enhances the osteogenic response during the early phase of osseointegration. This nanotopography-induced effect appeared to be independent of the underlying microscale topography. This study provides a first line of evidence that pre-determined nanopatterns on clinically relevant, screw-shaped, titanium implants can be recognized by cells in the complex in vivo environment. Until now, most of the knowledge relating to cell interactions with nanopatterned surfaces has been acquired from in vitro studies involving mostly two-dimensional nanopatterned surfaces of varying chemical composition. We have managed to superimpose pre-determined nanoscale topography on polished and micro-rough, screw-shaped, implants, without changes in the microscale topography or chemistry. This was achieved by colloidal lithography in combination with a thin titanium film coating on top of both nanopatterned and control implants. The early events of osseointegration were evaluated at the bone interface to these implants. The results revealed that nanotopography, as such, elicits downregulatory effects on the early recruitment and activity of inflammatory cells while enhancing osteogenic activity and woven bone formation. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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| 42. |
- Kristjansdottir, Hallgerdur Lind, et al.
(författare)
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Anemia is associated with increased risk of non-vertebral osteoporotic fractures in elderly men: the MrOS Sweden cohort
- 2022
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Ingår i: Archives of Osteoporosis. - : Springer Science and Business Media LLC. - 1862-3522 .- 1862-3514. ; 17:1
-
Tidskriftsartikel (refereegranskat)abstract
- This study includes 1005 men from the Gothenburg part of the Osteoporotic Fracture in Men Study (MrOS). Included are 66 men with anemia (hemoglobin < 130 g/L). The follow-up time was up to 16 years, and the main results are that anemia is associated with all fractures and non-vertebral osteoporotic fractures. Introduction Anemia and osteoporotic fractures are conditions that are associated with increased morbidity and mortality. Clinical studies have suggested that anemia can be used as a predictor of future osteoporotic fractures. Method Men from the Osteoporotic Fractures in Men Study (MrOS) Sweden, Gothenburg, with available hemoglobin (Hb) values (n = 1005, median age 75.3 years (SD 3.2)), were included in the current analyses. Of these, 66 suffered from anemia, defined as Hb < 130 g/L. Median follow-up time for fracture was 10.1 years and the longest follow-up time was 16.1 years. Results Men with anemia had, at baseline, experienced more falls and had a higher prevalence of diabetes, cancer, prostate cancer, hypertension, and stroke. Anemia was not statistically significantly associated with bone mineral density (BMD). Men with anemia had higher serum levels of fibroblast growth factor 23 (iFGF23) (p < 0.001) and phosphate (p = 0.001) and lower serum levels of testosterone (p < 0.001) and estradiol (p < 0.001). Moreover, men with anemia had an increased risk of any fracture (hazard ratio (HR) 1.97, 95% CI 1.28-3.02) and non-vertebral osteoporotic fracture (HR 2.15, 95% CI 1.18-3.93), after adjustment for age and total hip BMD, in 10 years. The risk for any fracture was increased in 10 and 16 years independently of falls, comorbidities, inflammation, and sex hormones. The age-adjusted risk of hip fracture was increased in men with anemia (HR 2.32, 95% CI 1.06-5.12), in 10 years, although this was no longer statistically significant after further adjustment for total hip BMD. Conclusions Anemia is associated with an increased risk for any fracture and non-vertebral osteoporotic fracture in elderly men with a long follow-up time. The cause is probably multifactorial and our results support that anemia can be used as a predictor for future fracture.
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| 43. |
- Käll, Mikael, 1963, et al.
(författare)
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Field enhancement and molecular response in surface-enhanced Raman scattering and fluorescence spectroscopy
- 2005
-
Ingår i: Journal of Raman Spectroscopy. - : Wiley. - 1097-4555 .- 0377-0486. ; 36, s. 510-514
-
Tidskriftsartikel (refereegranskat)abstract
- We present a theoretical analysis of surface-enhanced Raman scattering and fluorescence emission from chromophoric molecules located at electromagnetic 'hot spots' in nanoparticle aggregates. The model combines classical electrodynamic enhancement effects with molecular quantum dynamics and allows us to quantify various molecular cross-sections and spectral properties. For a model molecule that simulates rhodamine 6G, we find that an electromagnetic Raman enhancement of the order of loll results in an effective Raman cross-section of the order of 10(-14) cm(2), in agreement with single-molecule Raman measurements.
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| 44. |
- Lehmuskero, Anni, 1982, et al.
(författare)
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Laser Trapping of Colloidal Metal Nanoparticles
- 2015
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-086X .- 1936-0851. ; 9:4, s. 3453-3469
-
Tidskriftsartikel (refereegranskat)abstract
- Optical trapping using focused laser beams (laser tweezers) has been proven to be extremely useful for contactless manipulation of a variety of small objects, including biological cells, organelles within cells, and a wide range of other dielectric micro- and nano-objects. Colloidal metal nanoparticles have drawn increasing attention in the field of optical trapping because of their unique interactions with electromagnetic radiation, caused by surface plasmon resonance effects, enabling a large number of nano-optical applications of high current interest. Here we try to give a comprehensive overview of the field of laser trapping and manipulation of metal nanoparticles based on results reported in the recent literature. We also discuss and describe the fundamentals of optical forces in the context of plasmonic nanoparticles, including effects of polarization, optical angular momentum, and laser heating effects, as well as the various techniques that have been used to trap and manipulate metal nanoparticles. We conclude by suggesting possible directions for future research.
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| 45. |
- Lehmuskero, Anni, 1982, et al.
(författare)
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Plasmonic particles set into fast orbital motion by an optical vortex beam WARI SC, 1992, JOURNAL OF MODERN OPTICS, V39, P1097
- 2014
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Ingår i: Optics Express. - : The Optical Society. - 1094-4087 .- 1094-4087. ; 22:4, s. 4349-4356
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Tidskriftsartikel (refereegranskat)abstract
- We optically trap plasmonic gold particles in two dimensions and set them into circular motion around the optical axis using a helically phased vortex laser beam. The orbiting frequency of the particles reaches 86 Hz, which corresponds to a particle velocity of the order 1 mm per second, for an incident laser power of a few tens of milliwatts. The experimentally determined orbiting frequencies are found to be well in line with the notion that the beam carries an orbital angular momentum of hl per photon. (C) 2014 Optical Society of America
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| 46. |
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| 47. |
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| 48. |
- Lundgren, Johan, 1977-
(författare)
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Behind the Screen : -Internet-Based Cognitive Behavioural Therapy to Treat Depressive Symptoms in Persons with Heart Failure
- 2018
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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.
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| 49. |
- Miljkovic, Vladimir, 1982, et al.
(författare)
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Optical Forces in Plasmonic Nanoparticle Dimers
- 2010
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Ingår i: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 114:16, s. 7472-7479
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Tidskriftsartikel (refereegranskat)abstract
- We present calculations of the optical forces between two metal nanospheres forming a hybridized plasmonic chiller. We consider homo- and heterodimers and investigate different plane wave illumination configurations. The forces between the particles are calculated using kill Mie theory combined with the Maxwell stress tensor (MST) formalism, as well as by approximate methods, such as the Lorentz force (LF) approach taken in the dipole limit and calculations based on an optical potential. We show that the simplified calculation schemes can lead to serious errors in the case of strongly interacting particles and low damping. In particular, we find that equilibrium configurations, corresponding to vanishing optical forces, only are possible for homodimers illuminated in the end-fire configuration and for heterodimers, although multipolar effects and clamping radically reduce the repulsive interactions in the latter case.
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| 50. |
- Miljkovic, Vladimir, 1982, et al.
(författare)
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Simulating light scattering from supported plasmonic nanowires
- 2012
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Ingår i: Optics Express. - : Optical Society of America. - 1094-4087 .- 1094-4087. ; 20:10, s. 10816-10826
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Tidskriftsartikel (refereegranskat)abstract
- We present a method for calculating the differential scattering cross sections from nanostructures close to an interface separating two semi-infinitive dielectric media. The method combines a fast finite element software (Comsol multiphysics), used for calculations of the fields around and inside the structure, and the Green's functions method, which is used to find the far field distribution from the calculated total fields inside the nanostructure. We apply the method to calculations of scattering spectra from silver nanowires supported by an air-glass interface, a system that is of high current interest in relation to various nanophotonics applications. The results are analyzed in relation to analytical models and compared to experimentally measured spectra, to which we find a good agreement.
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