| 203891. |
- Viitala, Lauri, et al.
(författare)
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Shape and Phase Transitions in a PEGylated Phospholipid System
- 2019
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 35:11, s. 3999-4010
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Tidskriftsartikel (refereegranskat)abstract
- Poly(ethylene glycol) (PEG) polymers and PEG-conjugated lipids are widely used in bioengineering and drug transport applications. A PEG layer in a drug carrier increases hydrophilic repulsion, inhibits membrane fusion and serum opsonin interactions, and prolongs the storage and circulation time. It can also change the carrier shape and have an influence on many properties related to the content release of the carrier. In this paper, we focus on the physicochemical effects of PEGylation in the lipid bilayer. We introduce laurdanC as a fluorophore for shape recognition and phase transition detection. Together with laurdanC, cryogenic transmission electron microscopy, differential scanning calorimetry, molecular dynamics simulations, and small-angle X-ray scattering/wide-angle X-ray scattering, we acquire information of the particle/bilayer morphology and phase behavior in systems containing 1,2-dipalmitoyl-sn-glycero-3-phosphocholine:1,2-distearoyl-sn-glycero-3-phosphoethanolamine-PEG(2000) with different fractions. We find that PEGylation leads to two important and potentially usable features of the system. (1) Spherical vesicles present a window of elevated chain-melting temperatures and (2) lipid packing shape-controlled liposome-to-bicelle transition. The first finding is significant for targets requiring multiple release sequences and the second enables tuning the release by composition and the PEG polymer length. Besides drug delivery systems, the findings can be used in other smart soft materials with trigger-polymers as well.
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| 203892. |
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| 203893. |
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| 203894. |
- Vijayakrishnan, Jayaram, et al.
(författare)
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A genome-wide association study identifies risk loci for childhood acute lymphoblastic leukemia at 10q26.13 and 12q23.1
- 2017
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Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 0887-6924 .- 1476-5551. ; 31:3, s. 573-579
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWASs) have shown that common genetic variation contributes to the heritable risk of childhood acute lymphoblastic leukemia (ALL). To identify new susceptibility loci for the largest subtype of ALL, B-cell precursor ALL (BCP-ALL), we conducted a meta-analysis of two GWASs with imputation using 1000 Genomes and UK10K Project data as reference (totaling 1658 cases and 7224 controls). After genotyping an additional 2525 cases and 3575 controls, we identify new susceptibility loci for BCP-ALL mapping to 10q26.13 (rs35837782, LHPP, P=1.38 × 10-11) and 12q23.1 (rs4762284, ELK3, P=8.41 × 10-9). We also provide confirmatory evidence for the existence of independent risk loci at 9p21.3, but show that the association marked by rs77728904 can be accounted for by linkage disequilibrium with the rare high-impact CDKN2A p.Ala148Thr variant rs3731249. Our data provide further insights into genetic susceptibility to ALL and its biology.
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| 203895. |
- Vijayakrishnan, Jayaram, et al.
(författare)
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Genome-wide association study identifies susceptibility loci for B-cell childhood acute lymphoblastic leukemia
- 2018
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) have advanced our understanding of susceptibility to B-cell precursor acute lymphoblastic leukemia (BCP-ALL); however, much of the heritable risk remains unidentified. Here, we perform a GWAS and conduct a meta-analysis with two existing GWAS, totaling 2442 cases and 14,609 controls. We identify risk loci for BCP-ALL at 8q24.21 (rs28665337, P = 3.86 × 10-9, odds ratio (OR) = 1.34) and for ETV6-RUNX1 fusion-positive BCP-ALL at 2q22.3 (rs17481869, P = 3.20 × 10-8, OR = 2.14). Our findings provide further insights into genetic susceptibility to ALL and its biology.
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| 203896. |
- Vijayakrishnan, Jayaram, et al.
(författare)
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The 9p21.3 risk of childhood acute lymphoblastic leukaemia is explained by a rare high-impact variant in CDKN2A.
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) have provided strong evidence for inherited predisposition to childhood acute lymphoblastic leukaemia (ALL) identifying a number of risk loci. We have previously shown common SNPs at 9p21.3 influence ALL risk. These SNP associations are generally not themselves candidates for causality, but simply act as markers for functional variants. By means of imputation of GWAS data and subsequent validation SNP genotyping totalling 2,177 ALL cases and 8,240 controls, we have shown that the 9p21.3 association can be ascribed to the rare high-impact CDKN2A p.Ala148Thr variant (rs3731249; Odds ratio = 2.42, P = 3.45 × 10(-19)). The association between rs3731249 genotype and risk was not specific to particular subtype of B-cell ALL. The rs3731249 variant is associated with predominant nuclear localisation of the CDKN2A transcript suggesting the functional effect of p.Ala148Thr on ALL risk may be through compromised ability to inhibit cyclin D within the cytoplasm.
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| 203897. |
- Vijayan, Sajesh, et al.
(författare)
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Defensive shimmering responses in Apis dorsata are triggered by dark stimuli moving against a bright background
- 2022
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Ingår i: The Journal of experimental biology. - : The Company of Biologists. - 1477-9145 .- 0022-0949. ; 225:17
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Tidskriftsartikel (refereegranskat)abstract
- Giant honeybees, including the open-nesting Asian giant honeybee Apis dorsata, display a spectacular collective defence behaviour - known as 'shimmering' - against predators, which is characterised by travelling waves generated by individual bees flipping their abdomens in a coordinated and sequential manner across the bee curtain. We examined whether shimmering is visually mediated by presenting moving stimuli of varying sizes and contrasts to the background (dark or light) in bright and dim ambient light conditions. Shimmering was strongest under bright ambient light, and its strength declined under dim light in this facultatively nocturnal bee. Apis dorsata shimmered only when presented with the darkest stimulus against a light background, but not when this condition was reversed (light stimulus against dark background). This response did not attenuate with repeated exposure to the stimuli, suggesting that shimmering behaviour does not undergo habituation. We suggest that this is an effective anti-predator strategy in open-nesting A. dorsata colonies which are exposed to high ambient light, as flying predators are more easily detected when they appear as dark moving objects against a bright sky. Moreover, the stimulus detection threshold (smallest visual angular size) is much smaller in this anti-predatory context (1.6-3.4 deg) than in the context of foraging (5.7 deg), indicating that ecological context affects the visual detection threshold.
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| 203898. |
- Vijayan, Sajesh, et al.
(författare)
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Dim-light colour vision in the facultatively nocturnal Asian giant honeybee, Apis dorsata
- 2023
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Ingår i: Proceedings of the Royal Society B: Biological Sciences. - 0962-8452. ; 290:2004
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Tidskriftsartikel (refereegranskat)abstract
- We discovered nocturnal colour vision in the Asian giant honeybee Apis dorsata - a facultatively nocturnal species - at mesopic light intensities, down to half-moon light levels (approx. 10 -2 cd m -2). The visual threshold of nocturnality aligns with their reported nocturnal activity down to the same light levels. Nocturnal colour vision in A. dorsata is interesting because, despite being primarily diurnal, its colour vision capabilities extend into dim light, while the 'model' European honeybee Apis mellifera is reported to be colour-blind at twilight. By employing behavioural experiments with naturally nesting A. dorsata colonies, we show discrimination of the trained colour from other stimuli during the day, and significantly, even at night. Nocturnal colour vision in bees has so far only been reported in the obligately nocturnal carpenter bee Xylocopa tranquebarica. The discovery of colour vision in these two bee species, despite differences in the extent of their nocturnality and the limitations of their apposition compound eye optics, opens avenues for future studies on visual adaptations for dim-light colour vision, their role in pollination of flowers at night, and the effect of light pollution on nocturnal activity in A. dorsata, a ubiquitous pollinator in natural, agricultural and urban habitats in the Asian tropics and sub-tropics.
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| 203899. |
- Vijayan, Viji, et al.
(författare)
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Exploring Goal Conflicts and How They Are Managed in a Biomedical Laboratory Using Rasmussen's Model of Boundaries
- 2021
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Ingår i: Applied Biosafety. - : Mary Ann Liebert Inc. - 1535-6760 .- 2470-1246. ; 26:S1, s. 43-55
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Occupational health and safety management systems are widely used as a systematic approach to managing occupational health and safety. However, sometimes they are restrictive and underspecified to deal with dynamic workplace demands. Rasmussen used a model of boundaries to conceptualize this dynamic model of safety, where the space of possibilities lay within 3 boundaries and workers used various means to stay within the boundaries to remain both productive and safe at work. Methods: This study applied the Rasmussen model of boundaries to understand the factors that formed the boundaries, the gradients, and countergradients in a biomedical laboratory. Results: The most central goal was to be the first to publish, and this formed the boundary to scientific output failure; the boundary to unacceptable workload and boundary to functionally acceptable performance were the other 2 boundaries in line with the Rasmussen model. The workers had developed methods (mental risk assessment, teamwork, and experience and familiarity) of working, which ensured they remained productive and safe. This can be described as resilient performance, where resilience is not something that a system has but something it does to adjust their performance when faced with expected or unexpected changes. Discussion and Conclusion: A customized portfolio of rule-based non negotiable instructions and a risk assessment-based approach would be best suited for a biomedical laboratory. The workers have learned resilient performance on their own and unknowingly are already practicing this. It is now time to formally incorporate such practices into the safety systems of biomedical laboratories.
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| 203900. |
- Vijgen, Johan, et al.
(författare)
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Consensus statement of the European Heart Rhythm Association: updated recommendations for driving by patients with implantable cardioverter defibrillators
- 2009
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Ingår i: Europace. - : Oxford University Press (OUP). - 1532-2092 .- 1099-5129. ; 11:8, s. 1097-1107
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Forskningsöversikt (refereegranskat)abstract
- Patients with an implantable cardioverter defibrillator (ICD) have an ongoing risk of sudden incapacitation that might cause harm to others while driving a car. Driving restrictions vary across different countries in Europe. The most recent recommendations for driving of ICD patients in Europe were published in 1997 and focused mainly on patients implanted for secondary prevention. In recent years there has been a vast increase in the number of patients with an ICD and in the percentage of patients implanted for primary prevention. The EHRA task force on ICD and driving was formed to reassess the risk of driving for ICD patients based on the literature available. The recommendations are summarized in the following table and are further explained in the document.
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