| 1. |
- Luo, YQ, et al.
(författare)
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A focused microarray to assess dopaminergic and glial cell differentiation from fetal tissue or embryonic stem cells
- 2006
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Ingår i: Stem cells (Dayton, Ohio). - : Oxford University Press (OUP). - 1066-5099 .- 1549-4918. ; 24:4, s. 865-875
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Tidskriftsartikel (refereegranskat)abstract
- We designed oligonucleotide gene-specific probes to develop a focused array that can be used to discriminate between neural phenotypes, identify biomarkers, and provide an overview of the process of dopaminergic neuron and glial differentiation. We have arrayed approximately 100 genes expressed in dopaminergic neurons, oligodendrocytes, and astrocytes, an additional 200 known cytokines, chemokines, and their respective receptors, as well as markers for pluripotent and progenitor cells. The gene-specific 60-mer 3′ biased oligonucleotides for these 281 genes were arrayed in a 25 × 12 format based on function. Using human adult brain substantia nigra, human embryonic stem cells (ESCs), and the differentiated progeny of pluripotent cells, we showed that this array was capable of distinguishing dopaminergic neurons, glial cells, and pluripotent cells by their gene expression profiles in a concentration-dependent manner. Using linear correlation coefficients of input RNA with output intensity, we identified a list of genes that can serve as reporting genes for detecting dopaminergic neurons, glial cells, and contaminating ESCs and progenitors. Finally, we monitored NTera2 differentiation toward dopaminergic neurons and have shown the ability of this array to distinguish stages of differentiation and provide important clues to factors regulating differentiation, the degree of contaminating populations, and stage of cell maturity. We suggest that this focused array will serve as a useful complement to other large-scale arrays in routine assessment of cell properties prior to their therapeutic use.
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| 2. |
- Luo, Yuanze, et al.
(författare)
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A Multiwavelength View of IC 860: What Is in Action inside Quenching Galaxies * * Herschel is an ESA space observatory with science instruments provided by European-led principal investigator consortia and with important participation from NASA.
- 2022
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 938:1
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Tidskriftsartikel (refereegranskat)abstract
- We present a multiwavelength study of IC 860, a nearby post-starburst galaxy at the early stage of transitioning from blue and star forming to red and quiescent. Optical images reveal a galaxy-wide, dusty outflow originating from a compact core. We find evidence for a multiphase outflow in the molecular and neutral gas phase from the CO position-velocity diagram and NaD absorption features. We constrain the neutral mass outflow rate to be ∼0.5 M ⊙ yr−1, and the total hydrogen mass outflow rate to be ∼12 M ⊙ yr−1. Neither outflow component seems able to escape the galaxy. We also find evidence for a recent merger in the optical images, CO spatial distribution, and kinematics, and evidence for a buried active galactic nucleus in the optical emission line ratios, mid-IR properties, and radio spectral shape. The depletion time of the molecular gas reservoir under the current star formation rate is ∼7 Gyr, indicating that the galaxy could stay at the intermediate stage between the blue and red sequence for a long time. Thus the timescales for a significant decline in star formation rate (quenching) and gas depletion are not necessarily the same. Our analysis supports the quenching picture where outflows help suppress star formation by disturbing rather than expelling the gas and shed light on possible ongoing activities in similar quenching galaxies.
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| 3. |
- Hajradinovic, Yvonne, et al.
(författare)
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Family members' experiences of the end-of-life care environments in acute care settings : A photo-elicitation study
- 2018
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Ingår i: International Journal of Qualitative Studies on Health and Well-being. - : Taylor & Francis. - 1748-2623 .- 1748-2631. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: This article explores experiences of the acute-care environment as a setting for end-of-life (EoL) care from the perspective of family members of a dying person.Method: We used participant-produced photographs in conjunction with follow-up interviews with nine family members to persons at the EoL, cared for in two acute-care settings.Results: The interpretive description analysis process resulted in three constructed themes-Aesthetic and unaesthetic impressions, Space for privacy and social relationships, and Need for guidance in crucial times. Aspects of importance in the physical setting related to aesthetics, particularly in regard to sensory experience, and to a need for enough privacy to facilitate the maintenance of social relationships. Interactions between the world of family members and that of professionals were described as intrinsically related to guidance about both the material and immaterial environment at crucial times.Conclusion: The care environment, already recognized to have an impact in relation to patients, is concluded to also affect the participating family members in this study in a variety of ways.
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| 4. |
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| 5. |
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| 6. |
- Hajlane, Abdelghani
(författare)
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Hierarchical cellulosic reinforcement for composites: enhanced resistance to moisture and compatibility with polymers
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cellulosic fibres (flax, hemp, regenerated cellulose) possess decent mechanical properties and they are gaining interest as an alternative to synthetic reinforcement (e.g. glass fibres) in polymers to reduce the petroleum consumption and pollution. In particular, manmade Regenerated Cellulose Fibres (RCF) have been extensively studied as potential reinforcement in polymer composites. For high performances where stability is highly required, RCF among the cellulosic fibres are well qualified due the advantage of being continuous with regular cross section. However, the hydrophilic character and the sensitivity to moisture reduce the use of fibres based cellulose in composite applications. Indeed, the moisture absorption and the low compatibility leading to weak fibre/matrix interface are major factors behind the less interest of utilizing cellulosic fibres in composite intended for high performances. The short term objective of this thesis was to improve the resistance to moisture and the adhesion of regenerated cellulose fibres (RCF) commercialized under the trade name CORDENKA 700 super 3 to Epoxy matrix through chemical treatments by cellulose nano-crystals via silane coupling agents. In Paper I chemical treatments of cellulose nano-crystals using (CNC) esterification and amidification to attach long aliphatic chains is studied. The treatment was successfully achieved as confirmed by spectroscopic characterisations and led to a decrease of the moisture absorption. Contact angle measurement showed hydrophobic of CNC after treatment. In Paper II, CNC extracted from wastes of date palm tree were grafted on RCF fibres to create hierarchical structure. The effect of grafting CNC on RCF was evaluated by tensile tests both in static and loading-unloading. In fact, treatments were revealed to change slightly the microstructure where the orientation of both crystalline and amorphous phases where re-oriented as X-ray analysis showed. Grafted fibres based unidirectional composite were manufactured and transversally tested. Both mechanical properties and resistance to crack were significantly increased by fibre modification. Another approach for chemical modification of RCF fibres was developed in Paper III. In this paper, the process of modification of RCF by CNC is more environmentally friendly. The γ-methacryloxypropyltrimethoxysilane (MPS) was used as coupling agent to attach the CNC onto the fibres. This treatment involves a mixture of water and ethanol as solvents and was run at relatively low temperature. The impact of the treatment on fibres was scrutinised after each treatment basically by MPS and after grafting CNC. Results showed that the modification by silane decreased the stiffness and strength of fibres while the strain at failure was increased. However, after grafting CNC, stiffness and strain at failure were recovered while the strength remained at the same order of magnitude as for fibres treated only by the coupling agent. The effect of these treatments on moisture absorption and on the adhesion with epoxy matrix was the focus of the Paper IV. In this paper, it was shown that at high relative humidity (RH=64%) the treatment by CNC decreased water uptake by factor of two compare to untreated fibres. Besides, the treatments by CNC at different concentrations lessened the impact of moisture on stiffness and strength of fibres after exposure to the same humidity level (RH=64%). Moreover, the pull-out test performed on fibre bundles showed that the adhesion between fibre and matrix is less affected by moisture (samples conditioned at RH=64%) for CNC grafted fibres compare to untreated fibres. The treatment process by MPS was Scaled-up to Non-Crimp Fabric in Paper V and the interlaminar properties of composites reinforced with RCF were studied. Double cantilevered beam (DCB) test was used to characterize fracture toughness, under static and fatigue loading. Regenerated cellulose fibres exhibit highly nonlinear behaviour and strongly influence the performance of their composites. The obtained fracture toughness values were significantly high compared to those of synthetic fibre reinforced composites. However, due to the high nonlinearity, a concrete conclusion was not easy to make on the effect of fibre treatment on the materials performance. Thus, scanning electron microscopy studies were carried out on fracture surfaces which confirmed the treatment effect, qualitatively, on the improvement of interfacial adhesion.
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| 7. |
- Hajlane, Abdelghani, et al.
(författare)
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Use of micro-tomography for validation of method to identify interfacial shear strength from tensile tests of short regenerated cellulose fibre composites
- 2016
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Ingår i: IOP Conference Series. - 1757-8981 .- 1757-899X. ; 139
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Tidskriftsartikel (refereegranskat)abstract
- The interfacial shear strength of short regenerated cellulose fibre/polylactide composites was characterized by means of an industry-friendly adhesion test method. The interfacial shear strength was back-calculated from the experimental tensile stress-strain curves of composites by using a micro-mechanical model. The parameters characterizing the microstructure of the composites, e.g. fibre length and orientation distributions, used as input in the model were obtained by micro-tomography. The investigation was carried out on composites with untreated and surface treated fibres with various fibre weight contents (5wt%, 10wt%, and 15wt% for untreated fibres, and 15wt% for treated fibres). The properties of fibres were measured by an automated single fibre tensile test method. Based on these results, the efficiency of the fibre treatment to improve fibre/matrix adhesion is evaluated, and the applicability of the method to measure the interfacial shear strength is discussed. The results are compared with data from previous work, and with other results from the literature
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| 8. |
- Lundberg, Björn
(författare)
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Lång väg till jämställt OS
- 2020
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Ingår i: Historiskan : Sveriges första kvinnohistoriska tidning. - 2002-150X. ; 2020:2, s. 16-25
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 9. |
- Lundberg, Björn, 1982, et al.
(författare)
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New Methodology for Transient Engine Rig Experiments for Efficient Parameter Estimation
- 2013
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Ingår i: SAE International Journal of Engines. - : SAE International. - 1946-3944 .- 1946-3936. ; 6:4, s. 1995-2003
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Tidskriftsartikel (refereegranskat)abstract
- Introduction The diesel oxidation catalyst (DOC) is a well established technology to reduce CO and hydrocarbon (HC) emissions from diesel engines. Strengthened emission standards have made the importance of the DOC even greater in recent years since it plays an indispensible role in enhancing the performance of diesel particulate filters (DPF) and selective catalytic reduction (SCR) by utilization of NO oxidation to NO2. Therefore correct prediction of the DOC performance is very important for simulations of the entire aftertreatment system. When performing kinetic parameter estimation, laboratory scale experimental data is generally used. In laboratory scale it is possible to use essentially any combination of exhaust gas composition and temperature which makes it possible to estimate parameters over a wide range of conditions. However the applicability of these parameters in full scale models is often limited. Parameter estimation on full scale engine rig experiments on the other hand is limited by the exhaust compositions that are possible for the engine to produce. As a result, the fraction of CO is closely linked to the fraction of hydrocarbons and the fraction of NO is closely linked to the fraction of NO2. When switching between two engine operation points it generally takes several minutes before the properties of the emissions have stabilized. This does not only make the experiments time consuming, but it also complicates the transient modeling of the DOC since the changes in inlet properties are far from ideal step functions. In this study an experimental set-up is presented that makes it possible to change the inlet properties of the DOC without changing engine load point which results in much faster transients. The method also makes it possible to change the fraction of NO2 independently of the NO fraction. Method To achieve more controlled and faster changes in the inlet to the catalyst an extra DOC (DOC1) with the possibility for bypass flow and an SCR with urea injection are mounted before the catalyst. The fraction of exhaust gas flow through DOC1 allows variation in the conversion of HC and CO to CO2 and the conversion of NO to NO2. By injecting different amounts of urea the conversion of NO2 and NO to N2 is controlled. The SCR also makes it possible to obtain an inlet composition to the DOC that contains NO2 but is free of NO. Fast changes in inlet conditions are in other words possible and it is also possible to achieve compositions not achievable by only controlling the operation of the engine. Experiments have been performed at several engine conditions and using catalysts with different noble metal loading, lengths and washcoat thicknesses. To achieve high HC and CO concentrations the engine was tuned to run with late fuel injection. Significance A method to carry out engine rig experiments with a wider range of emission conditions makes it possible to more efficiently retune model parameters for a full-scale catalyst from literature data. This should result in faster model development which is of great importance in exhaust gas aftertreatment.
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| 10. |
- Lundberg, Bengt, et al.
(författare)
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Optimum transmission of elastic waves through joints
- 1979
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Ingår i: Wave motion. - : Elsevier BV. - 0165-2125 .- 1878-433X. ; 1:3, s. 193-200
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Tidskriftsartikel (refereegranskat)abstract
- An elastic wave transmitting system (e.g. a nonuniform elastic rod) consisting of an input section with constant impedance, a joint with variable impedance, and an output section with constant impedance is considered. The efficiency of energy transmission (the ratio of transmitted to incident elastic wave energy) is determined and the following optimization problem is solved for two sample cases: Given the properties of the wave transmitting system and a limited duration of the incident wave, determine the shape of this wave such that the efficiency of energy transmission is maximized. In the first case (a joint with constant impedance) the optimization problem leads to a matrix eigenvalue problem. In the second case (a joint with concentrated mass) it leads to an eigenvalue problem for an integral equation. The efficiencies obtained for the optimum incident waves are compared with those obtained for rectagular incident waves an it is found that the differences are generally small. The results, which are discussed with particular reference to the transmission of elastic wave energy through drill rod joints, can also be interpreted for e.g. shallow water waves and electromagnetic waves in a transmission line.
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