| 1. |
- Aguilar, Ximena, et al.
(författare)
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Myofibroblasts in the normal conjunctival surface.
- 2010
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Ingår i: Acta ophthalmologica. - : Wiley. - 1755-3768 .- 1755-375X. ; 88:4, s. 407-12
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To investigate the occurrence of myofibroblasts (MFBs) in the normal conjunctival surface and to evaluate any anatomical and time-related variations. METHODS: MFBs were screened among healthy individuals (35 eyes) by collecting impression cytology (IC) samples from the bulbar conjunctiva. A cohort of volunteers (12 eyes) was followed for 1 year by taking two to five imprints every month. MFBs were identified by immunohistochemical localization of the MFB marker alpha-smooth-muscle actin (alpha-SMA). RESULTS: Using a filter imprint technique, MFBs were found consistently in 94% of samples from the conjunctival surface of participating individuals. The overall MFB levels, expressed as percentage of all cells on the filter, were highest in March-May [mean 4.1%, standard deviation (SD) +/- 1.5] and lowest in December-February (mean 1.2%, SD +/- 0.5). The difference was statistically significant [p < 0.0005, Friedman test, one-way repeated measures analysis of variance (anova)]. Moreover, there was a clear divergence of MFB density between the nasal, temporal, superior and inferior bulbar conjunctiva (mean 1.7%, 1.9%, 22% and 9.7%, respectively). CONCLUSION: MFBs, known as a cellular constituent of granulation tissue in wound healing, occur in the normal conjunctival surface, which is a novel finding. Our results also show that MFB level follows a seasonal variation pattern in a temperate climate, increasing in April-September and decreasing in October-March. This variation might reflect a degree of a transient or ongoing state of tissue repair after conjunctival trauma or stress caused by exposure to environmental factors.
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| 2. |
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| 3. |
- Holding, Benjamin C., et al.
(författare)
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The effect of sleep deprivation on objective and subjective measures of facial appearance
- 2019
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Ingår i: Journal of Sleep Research. - : Wiley. - 0962-1105 .- 1365-2869. ; 28:6
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Tidskriftsartikel (refereegranskat)abstract
- The faces of people who are sleep deprived are perceived by others as looking paler, less healthy and less attractive compared to when well rested. However, there is little research using objective measures to investigate sleep-loss-related changes in facial appearance. We aimed to assess the effects of sleep deprivation on skin colour, eye openness, mouth curvature and periorbital darkness using objective measures, as well as to replicate previous findings for subjective ratings. We also investigated the extent to which these facial features predicted ratings of fatigue by others and could be used to classify the sleep condition of the person. Subjects (n = 181) were randomised to one night of total sleep deprivation or a night of normal sleep (8-9 hr in bed). The following day facial photographs were taken and, in a subset (n = 141), skin colour was measured using spectrophotometry. A separate set of participants (n = 63) later rated the photographs in terms of health, paleness and fatigue. The photographs were also digitally analysed with respect to eye openness, mouth curvature and periorbital darkness. The results showed that neither sleep deprivation nor the subjects' sleepiness was related to differences in any facial variable. Similarly, there was no difference in subjective ratings between the groups. Decreased skin yellowness, less eye openness, downward mouth curvature and periorbital darkness all predicted increased fatigue ratings by others. However, the combination of appearance variables could not be accurately used to classify sleep condition. These findings have implications for both face-to-face and computerised visual assessment of sleep loss and fatigue.
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| 4. |
- Kurien, Matthew, et al.
(författare)
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Persistent mucosal damage and the risk of epilepsy in people with celiac disease
- 2018
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Ingår i: European Journal of Neurology. - : John Wiley & Sons. - 1351-5101 .- 1468-1331. ; 25:3, s. 592-e38
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Celiac disease (CD) is associated with an increased risk of developing epilepsy, a risk that persists after CD diagnosis. A significant proportion of CD patients have persistent villous atrophy (VA) on follow-up biopsy. This study's objective was to determine whether persistent VA on follow-up biopsy affects long-term epilepsy risk and epilepsy-related hospital emergency admissions.METHODS: Nationwide Cohort Study. We identified all people in Sweden with histological evidence of CD who underwent a follow-up small intestinal biopsy (1969-2008). We compared those with persistent VA to those who showed histological improvement, assessing the development of epilepsy and related emergency hospital admissions (defined according to relevant ICD codes in the Swedish Patient Register). Cox regression analysis was used to assess outcome measures.RESULTS: Of 7590 people with CD who had a follow-up biopsy, VA was present in 43%. The presence of persistent VA was significantly associated with a reduced risk of developing newly-diagnosed epilepsy (hazard ratio [HR] 0.61; 95% confidence interval [CI] 0.38-0.98). On stratified analysis this effect was primarily amongst males (HR 0.35; 95 CI 0.15-0.80). Among the 58 CD patients with a prior diagnosis of epilepsy, those with persistent VA were less likely to visit an emergency department with epilepsy (HR 0.37; 95%CI 0.09-1.09).CONCLUSIONS: In a population-based study of CD individuals, persisting VA on follow up biopsy was associated with reduced future risk of developing epilepsy but did not influence emergency epilepsy-related hospital admissions. Mechanisms as to why persistent VA confers this benefit requires further exploration. This article is protected by copyright. All rights reserved.
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| 5. |
- Marimuthu, Aravindh N., et al.
(författare)
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Laboratory gas-phase vibrational spectra of [C3H3]+ isomers and isotopologues by IRPD spectroscopy
- 2020
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Ingår i: Journal of Molecular Spectroscopy. - : Elsevier BV. - 0022-2852 .- 1096-083X. ; 374
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Tidskriftsartikel (refereegranskat)abstract
- Gas phase vibrational spectra of [C3H3]+ isomers and their fully deuterated isotopologues measured in a cryogenic 22-pole ion trap are presented. The widely tunable free electron laser for infrared experiments, FELIX, was employed to cover the frequency range 500–2400 cm−1, complemented with an OPO/OPA system covering 2800–3400 cm−1. Spectral assignments for both the linear and cyclic isomeric form (H2C3H+ and c-C3H3+, respectively) are made based on various high-level computational studies. The effect of ion source conditions and different precursors (allene and propargyl chloride) for the preferential production of a specific isomer is discussed. The perturbation of the vibrational band position due to complexation with neon in the recorded infrared-predissociation (IRPD) spectra are also reported in this study.
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| 6. |
- Richardson, Vincent, et al.
(författare)
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Experimental and Computational Studies on the Reactivity of Methanimine Radical Cation (H2CNH+•) and its Isomer Aminomethylene (HCNH2+•) With C2H2
- 2021
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Ingår i: Frontiers in Astronomy and Space Sciences. - : Frontiers Media SA. - 2296-987X. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Experimental and theoretical studies are presented on the reactivity of the radical cation isomers H2CNH+• (methanimine) and HCNH2+• (aminomethylene) with ethyne (C2H2). Selective isomer generation is performed via dissociative photoionization of suitable neutral precursors as well as via direct photoionization of methanimine. Reactive cross sections (in absolute scales) and product branching ratios are measured as a function of photon and collision energies. Differences between isomers’ reactivity are discussed in light of ab-initio calculations of reaction mechanisms. The major channels, for both isomers, are due to H atom elimination from covalently bound adducts to give [C3NH4]+. Theoretical calculations show that while for the reaction of HCNH2+• with acetylene any of the three lowest energy [C3NH4]+ isomers can form via barrierless and exothermic pathways, for the H2CNH+• reagent the only barrierless pathway is the one leading to the production of protonated vinyl cyanide (CH2CHCNH+), a prototypical branched nitrile species that has been proposed as a likely intermediate in star forming regions and in the atmosphere of Titan. The astrochemical implications of the results are briefly addressed.
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| 7. |
- Richardson, V., et al.
(författare)
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The reactivity of methanimine radical cation (H2CNH.+) and its isomer aminomethylene (HCNH2.+) with methane
- 2021
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 775
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Tidskriftsartikel (refereegranskat)abstract
- Experimental and theoretical studies are presented on the reactions of the isomeric radical cations H2CNH+ and HCNH2+ with CH4. Ionic isomers were generated selectively by VUV dissociative photoionization of azetidine and cyclopropylamine precursors respectively. Both exclusively give H2CNH2+ plus CH3 as products, but differences are observed related to a competition between stripping and complex-mediated H-transfer. Astrochemical implications for Titan’s atmosphere are briefly discussed, where the presence of methanimine (H2CNH), a key prebiotic molecule and a potential precursor for tholins, is proposed on the basis of atmospheric models and the observation of CH2NH2+ ions in Cassini mass spectrometric data.
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| 8. |
- Richmond, Erinn K., et al.
(författare)
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A diverse suite of pharmaceuticals contaminates stream and riparian food webs
- 2018
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Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- A multitude of biologically active pharmaceuticals contaminate surface waters globally, yet their presence in aquatic food webs remain largely unknown. Here, we show that over 60 pharmaceutical compounds can be detected in aquatic invertebrates and riparian spiders in six streams near Melbourne, Australia. Similar concentrations in aquatic invertebrate larvae and riparian predators suggest direct trophic transfer via emerging adult insects to riparian predators that consume them. As representative vertebrate predators feeding on aquatic invertebrates, platypus and brown trout could consume some drug classes such as antidepressants at as much as one-half of a recommended therapeutic dose for humans based on their estimated prey consumption rates, yet the consequences for fish and wildlife of this chronic exposure are unknown. Overall, this work highlights the potential exposure of aquatic and riparian biota to a diverse array of pharmaceuticals, resulting in exposures to some drugs that are comparable to human dosages.
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| 9. |
- Sundelin, David
(författare)
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Isomers of ions in space and planetary atmospheres
- 2022
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Ion chemistry has become increasingly important in the evolution of the chemical inventory of extraterrestrial environments. Isomers of ions have also come to play an important role as, in many instances, the cold environments in the interstellar medium and high layers of planet and satellite atmospheres do not supply enough energy to overcome isomerization barriers and the isomers effectively act as separate molecules. In this licentiate thesis, several studies of the [CH3N]+ isomers are presented. Reactivity studies of the two isomers, the methanimine radical cation (H2CNH+) and aminomethylene (HCNH2+) with hydrocarbons C2H4, C2H2 and CH4, and IRPD spectroscopy of both species have been performed. Complimentary ab initio calculations aid in the determination of formation pathways of observed product channels and in the assignment of the vibrational bands seen in the IRPD spectrum.The results show that reaction pathways of the two isomers generally involve adduct formation followed by hydrogen ejection where the product or pathway is dependent on the ingoing reactant isomer. The IRPD spectrum allows identification of the different isomers via vibrational transitions. Isomer generation by electron ionization favours methanimine cation production with an abundance of 70% while with VUV photoionization it is possible to selectively produce isomers. It is concluded that isomerism must be considered when investigating the chemical environment of interstellar objects.
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| 10. |
- Sundelin, David, et al.
(författare)
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Spectroscopic characterisation of the isomeric H2NCH+ and H2CNH+ radical cations
- 2022
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Ingår i: Journal of Molecular Spectroscopy. - : Elsevier BV. - 0022-2852 .- 1096-083X. ; 387
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Tidskriftsartikel (refereegranskat)abstract
- The vibrational transitions and the relative abundances of the two isomeric ions H2CNH+ and H2NCH+ generated through electron impact ionisation have been investigated in a noble gas tagging experiment. It could be shown that both species were formed with an abundance of 70 and 30% for H2NCH+ and H2CNH+, respectively. The obtained vibrational bands of the two species have been assigned to vibrational transitions through comparison with the results of ab initio calculations. These computations also predict both species to be moderately polar. The present investigations show that both isomers should be included in chemical model calculations of dark interstellar clouds, protoplanetary disks, star-forming regions as well as planetary atmospheres.
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