| 11. |
- Wiedorn, Max O., et al.
(författare)
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Megahertz serial crystallography
- 2018
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Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- The new European X-ray Free-Electron Laser is the first X-ray free-electron laser capable of delivering X-ray pulses with a megahertz inter-pulse spacing, more than four orders of magnitude higher than previously possible. However, to date, it has been unclear whether it would indeed be possible to measure high-quality diffraction data at megahertz pulse repetition rates. Here, we show that high-quality structures can indeed be obtained using currently available operating conditions at the European XFEL. We present two complete data sets, one from the well-known model system lysozyme and the other from a so far unknown complex of a beta-lactamase from K. pneumoniae involved in antibiotic resistance. This result opens up megahertz serial femtosecond crystallography (SFX) as a tool for reliable structure determination, substrate screening and the efficient measurement of the evolution and dynamics of molecular structures using megahertz repetition rate pulses available at this new class of X-ray laser source.
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| 12. |
- Halme, P., et al.
(författare)
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Challenges of ecological restoration : Lessons from forests in northern Europe
- 2013
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Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 167, s. 248-256
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Forskningsöversikt (refereegranskat)abstract
- The alarming rate of ecosystem degradation has raised the need for ecological restoration throughout different biomes and continents. North European forests may appear as one of the least vulnerable ecosystems from a global perspective, since forest cover is not rapidly decreasing and many ecosystem services remain at high level. However, extensive areas of northern forests are heavily exploited and have lost a major part of their biodiversity value. There is a strong requirement to restore these areas towards a more natural condition in order to meet the targets of the Convention on Biological Diversity. Several northern countries are now taking up this challenge by restoring forest biodiversity with increasing intensity. The ecology and biodiversity of boreal forests are relatively well understood making them a good model for restoration activities in many other forest ecosystems. Here we introduce northern forests as an ecosystem, discuss the historical and recent human impact and provide a brief status report on the ecological restoration projects and research already conducted there. Based on this discussion, we argue that before any restoration actions commence, the ecology of the target ecosystem should be established with the need for restoration carefully assessed and the outcome properly monitored. Finally, we identify the most important challenges that need to be solved in order to carry out efficient restoration with powerful and long-term positive impacts on biodiversity: coping with unpredictability, maintaining connectivity in time and space, assessment of functionality, management of conflicting interests and social restrictions and ensuring adequate funding. © 2013 Elsevier Ltd.
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| 13. |
- Douglas, Timothy E. L., et al.
(författare)
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Pectin coatings on titanium alloy scaffolds produced by additive manufacturing : Promotion of human bone marrow stromal cell proliferation
- 2018
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Ingår i: Materials letters (General ed.). - : Elsevier BV. - 0167-577X .- 1873-4979. ; 227, s. 225-228
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Tidskriftsartikel (refereegranskat)abstract
- Ti6Al4V is a popular biomaterial for load-bearing implants for bone contact, which can be fabricated by additive manufacturing technologies. Their long-term success depends on their stable anchoring in surrounding bone, which in turn depends on formation of new bone tissue on the implant surface, for which adhesion and proliferation of bone-forming cells is a pre-requisite. Hence, surface coatings which promote cell adhesion and proliferation are desirable. Here, Ti6Al4V discs prepared by additive manufacturing (EBM) were coated with layers of pectins, calcium-binding polysaccharides derived from citrus (C) and apple (A), which also contained alkaline phosphatase (ALP), the enzyme responsible for mineralization of bone tissue. Adhesion and proliferation of human bone marrow stromal cells (hBMSC) were assessed. Proliferation after 7 days was increased by A-ALP coatings and, in particular, by C-ALP coatings. Cell morphology was similar on coated and uncoated samples. In conclusion, ALP-loaded pectin coatings promote hBMSC adhesion and proliferation.
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| 14. |
- Heikkila, K., et al.
(författare)
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Job strain and the risk of severe asthma exacerbations : a meta-analysis of individual-participant data from 100 000 European men and women
- 2014
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Ingår i: Allergy. European Journal of Allergy and Clinical Immunology. - : Wiley. - 0105-4538 .- 1398-9995. ; 69:6, s. 775-783
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundMany patients and healthcare professionals believe that work-related psychosocial stress, such as job strain, can make asthma worse, but this is not corroborated by empirical evidence. We investigated the associations between job strain and the incidence of severe asthma exacerbations in working-age European men and women. MethodsWe analysed individual-level data, collected between 1985 and 2010, from 102 175 working-age men and women in 11 prospective European studies. Job strain (a combination of high demands and low control at work) was self-reported at baseline. Incident severe asthma exacerbations were ascertained from national hospitalization and death registries. Associations between job strain and asthma exacerbations were modelled using Cox regression and the study-specific findings combined using random-effects meta-analyses. ResultsDuring a median follow-up of 10years, 1 109 individuals experienced a severe asthma exacerbation (430 with asthma as the primary diagnostic code). In the age- and sex-adjusted analyses, job strain was associated with an increased risk of severe asthma exacerbations defined using the primary diagnostic code (hazard ratio, HR: 1.27, 95% confidence interval, CI: 1.00, 1.61). This association attenuated towards the null after adjustment for potential confounders (HR: 1.22, 95% CI: 0.96, 1.55). No association was observed in the analyses with asthma defined using any diagnostic code (HR: 1.01, 95% CI: 0.86, 1.19). ConclusionsOur findings suggest that job strain is probably not an important risk factor for severe asthma exacerbations leading to hospitalization or death.
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| 15. |
- Theorell, Töres, et al.
(författare)
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Job strain in relation to body mass index : pooled analysis of 160 000 adults from 13 cohort studies
- 2012
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 272:1, s. 65-73
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Tidskriftsartikel (refereegranskat)abstract
- Job strain in relation to body mass index: pooled analysis of 160 000 adults from 13 cohort studies. J Intern Med 2012; 272: 6573. Background. Evidence of an association between job strain and obesity is inconsistent, mostly limited to small-scale studies, and does not distinguish between categories of underweight or obesity subclasses. Objectives. To examine the association between job strain and body mass index (BMI) in a large adult population. Methods. We performed a pooled cross-sectional analysis based on individual-level data from 13 European studies resulting in a total of 161 746 participants (49% men, mean age, 43.7 years). Longitudinal analysis with a median follow-up of 4 years was possible for four cohort studies (n = 42 222). Results. A total of 86 429 participants were of normal weight (BMI 18.524.9 kg m-2), 2149 were underweight (BMI < 18.5 kg m-2), 56 572 overweight (BMI 25.029.9 kg m-2) and 13 523 class I (BMI 3034.9 kg m-2) and 3073 classes II/III (BMI = 35 kg m-2) obese. In addition, 27 010 (17%) participants reported job strain. In cross-sectional analyses, we found increased odds of job strain amongst underweight [odds ratio 1.12, 95% confidence interval (CI) 1.001.25], obese class I (odds ratio 1.07, 95% CI 1.021.12) and obese classes II/III participants (odds ratio 1.14, 95% CI 1.011.28) as compared with participants of normal weight. In longitudinal analysis, both weight gain and weight loss were related to the onset of job strain during follow-up. Conclusions. In an analysis of European data, we found both weight gain and weight loss to be associated with the onset of job strain, consistent with a U-shaped cross-sectional association between job strain and BMI. These associations were relatively modest; therefore, it is unlikely that intervention to reduce job strain would be effective in combating obesity at a population level.
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| 16. |
- Chudinova, Ekaterina A., et al.
(författare)
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Adhesion, proliferation, and osteogenic differentiation of human mesenchymal stem cells on additively manufactured Ti6Al4V alloy scaffolds modified with calcium phosphate nanoparticles
- 2019
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Ingår i: Colloids and Surfaces B. - : Elsevier BV. - 0927-7765 .- 1873-4367. ; 176, s. 130-139
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, biocomposites based on 3D porous additively manufactured Ti6Al4V (Ti64) scaffolds modified with biocompatible calcium phosphate nanoparticles (CaPNPs) were investigated. Ti64 scaffolds were manufactured via electron beam melting technology using an Arcam machine. Electrophoretic deposition was used to modify the scaffolds with CaPNPs, which were synthesized by precipitation in the presence of polyethyleneimine (PEI). Dynamic light scattering revealed that the CaP/PEI nanoparticles had an average size of 46 ± 18 nm and a zeta potential of +22 ± 9 mV. Scanning electron microscopy (SEM) revealed that the obtained spherical CaPNPs had an average diameter of approximately 90 nm. The titanium-based scaffolds coated with CaPNPs exhibited improved hydrophilic surface properties, with a water contact angle below 5°. Cultivation of human mesenchymal stem cells (hMSCs) on the CaPNPs-coated Ti64 scaffolds indicated that the improved hydrophilicity was beneficial for the attachment and growth of cells in vitro. The Ti6Al4V/CaPNPs scaffold supported an increase in the alkaline phosphatase (ALP) activity of cells. In addition to the favourable cell proliferation and differentiation, Ti6Al4V/CaPNPs scaffolds displayed increased mineralization compared to non-coated Ti6Al4V scaffolds. Thus, the developed composite 3D scaffolds of Ti6Al4V functionalized with CaPNPs are promising materials for different applications related to bone repair.
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| 17. |
- Gylle, A. Maria, et al.
(författare)
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Photosynthesis in relation to D1, PsaA and Rubisco in marine and brackish water ecotypes of Fucus vesiculosus and Fucus radicans (Phaeophyceae)
- 2013
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Ingår i: Hydrobiologia. - : Springer Science and Business Media LLC. - 0018-8158 .- 1573-5117. ; 700:1, s. 109-119
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate photosynthetic differences between the marine, Norwegian Sea ecotype and the brackish, Bothnian Sea ecotype of F. vesiculosus and F. radicans and to see whether photosynthetic differences could be connected with the relative amounts of D1 protein (PSII), PsaA (PSI) protein and/or Rubisco. For this purpose, we tested if a higher photosynthetic maximum (P (max)) in the Atlantic Ocean ecotype of F. vesiculosus relative to the Baltic Sea ecotype, and an increase of the P (max) in Baltic Sea ecotype of F. vesiculosus at higher salinity, could be due to an increase in the relative amounts of Rubisco. The proteins have been evaluated on a relative basis. Immunoblot signals showed that the amount of Rubisco was higher in both ecotypes of F. vesiculosus than in F. radicans, but no differences could be detected between the two ecotypes of F. vesiculosus. The results suggest an uneven photosystem protein stoichiometry in Fucus, with more of the PSI protein PsaA relative to the PSII protein D1. The difference in P (max) between the two ecotypes of F. vesiculosus might be related to the difficulties for the algae to adapt to the environment in Bothnian Sea.
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| 18. |
- Gylle, A. Maria, et al.
(författare)
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Salinity effect on oxygen evolution and the relative amount of RuBisCO in the brackish Fucus vesiculosus L. (Phaeophyceae)
- 2007
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Ingår i: Pysiological responses of marine and brackish Fucuc vesiculosus L with respect to salinity. - Sundsvall : Mittuniversitetet. - 9789185317417 ; , s. 1-8
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The sublittoral Fucus vesiculosus from the brackish Bothnian Sea is adapted to a salinity of 4-5 practical salinity units (psu). This study investigated the effect of different salinities (5, 10, 20 and 35 psu) on maximum photosynthetic capacity (Pmax) and the relative amount of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco). The results revealed a higher Pmax at higher salinities with the maximum at 10 psu. Higher salinities also resulted in increased relative amounts of Rubisco but this was not well correlated with the increased Pmax. Therefore, the amount of Rubisco doesn�t appear to be the main reason for the increased Pmax in higher salinities.
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| 19. |
- Heikkilä, K., et al.
(författare)
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Job strain and health-related lifestyle : Findings from an individual-participant meta-analysis of 118 000 working adults
- 2013
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Ingår i: American Journal of Public Health. - 0090-0036 .- 1541-0048. ; 103:11, s. 2090-2097
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. We examined the associations of job strain, an indicator of work-related stress, with overall unhealthy and healthy lifestyles. Methods. We conducted a meta-analysis of individual-level data from 11 European studies (cross-sectional data: n = 118 701; longitudinal data: n = 43 971). We analyzed job strain as a set of binary (job strain vs no job strain) and categorical (high job strain, active job, passive job, and low job strain) variables. Factors used to define healthy and unhealthy lifestyles were body mass index, smoking, alcohol intake, and leisure-time physical activity. Results. Individuals with job strain were more likely than those with no job strain to have 4 unhealthy lifestyle factors (odds ratio [OR] = 1.25; 95% confidence interval [CI] = 1.12, 1.39) and less likely to have 4 healthy lifestyle factors (OR = 0.89; 95% CI = 0.80, 0.99). The odds of adopting a healthy lifestyle during study follow-up were lower among individuals with high job strain than among those with low job strain (OR = 0.88; 95% CI = 0.81, 0.96). Conclusions. Work-related stress is associated with unhealthy lifestyles and the absence of stress is associated with healthy lifestyles, but longitudinal analyses suggest no straightforward cause-effect relationship between workrelated stress and lifestyle. Copyright © 2013 by the American Public Health Association®.
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| 20. |
- Madsen, I. E. H., et al.
(författare)
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Job strain as a risk factor for clinical depression : systematic review and meta-analysis with additional individual participant data
- 2017
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Ingår i: Psychological Medicine. - : Cambridge University Press. - 0033-2917 .- 1469-8978. ; 47:8, s. 1342-1356
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Forskningsöversikt (refereegranskat)abstract
- Background. Adverse psychosocial working environments characterized by job strain (the combination of high demands and low control at work) are associated with an increased risk of depressive symptoms among employees, but evidence on clinically diagnosed depression is scarce. We examined job strain as a risk factor for clinical depression. Method. We identified published cohort studies from a systematic literature search in PubMed and PsycNET and obtained 14 cohort studies with unpublished individual-level data from the Individual-Participant-Data Meta-analysis in Working Populations (IPD-Work) Consortium. Summary estimates of the association were obtained using random-effects models. Individual-level data analyses were based on a pre-published study protocol. Results. We included six published studies with a total of 27 461 individuals and 914 incident cases of clinical depression. From unpublished datasets we included 120 221 individuals and 982 first episodes of hospital-treated clinical depression. Job strain was associated with an increased risk of clinical depression in both published [relative risk (RR) = 1.77, 95% confidence interval (CI) 1.47-2.13] and unpublished datasets (RR = 1.27, 95% CI 1.04-1.55). Further individual participant analyses showed a similar association across sociodemographic subgroups and after excluding individuals with baseline somatic disease. The association was unchanged when excluding individuals with baseline depressive symptoms (RR = 1.25, 95% CI 0.94-1.65), but attenuated on adjustment for a continuous depressive symptoms score (RR = 1.03, 95% CI 0.81-1.32). Conclusions. Job strain may precipitate clinical depression among employees. Future intervention studies should test whether job strain is a modifiable risk factor for depression.
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