| 1. |
- Ahlström, Stina, et al.
(författare)
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Characteristics of post-mortem beta-hydroxybutyrate-positivet cases : A retrospective study on age, sex and BMI in 1407 forensic autopsies
- 2021
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Ingår i: Forensic Science International. - : Elsevier BV. - 0379-0738 .- 1872-6283. ; 325
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundPost-mortem biochemistry, including the analysis of beta-hydroxybutyrate (BHB), is increasingly employed in forensic medicine, especially in conditions such as diabetes and chronic alcoholism. However, not much is known about the associations between age, body mass index (BMI), and sex and BHB concentrations in ketoacidotic conditions.AimTo retrospectively study the association between age, BMI and sex in several conditions, such as diabetic ketoacidosis (DKA), alcoholic ketoacidosis (AKA), and elevated post-mortem BHB concentrations.Methods1407 forensic autopsy cases analysed for BHB were grouped by diagnosis: DKA, AKA, HHS [hyperosmolar hyperglycaemic state], acidosis NOS [not otherwise specified], or hypothermia. Age, sex, BMI and the concentrations of blood alcohol, vitreous glucose and blood BHB were recorded.ResultsCases of AKA and DKA were most numerous (184 and 156, respectively). In DKA and in its male subgroup, cases with severe ketosis (BHB>1000 µg/g) were younger and had a lower BMI than those with moderate ketosis (BHB 250–1000 µg/g) and controls (P<0.001). In DKA and in its female subgroup, cases with moderate ketosis cases were older (P = 0.0218 and P = 0.0083) than controls. In AKA and in its male subgroup, cases with severe ketosis had a lower BMI than those with moderate ketosis (P = 0.0391 and P = 0.0469) and controls (P<0.001). Cases with moderate ketosis had a lower BMI than controls (P<0.001).ConclusionsBHB concentration is associated with BMI in DKA and AKA, and with both BMI and age in DKA. Constitutional factors should, therefore, be considered in potential AKA and DKA cases.
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| 2. |
- Ahlström, Stina, et al.
(författare)
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The Importance of BHB Testing on the Post-Mortem Diagnosis of Ketoacidosis
- 2022
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Ingår i: Biomolecules. - : MDPI. - 2218-273X. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Although beta-hydroxybutyrate (BHB) analysis has proved its importance in forensic pathology, its effects on cause-of-death diagnostics are unaddressed. Therefore, this study aims at evaluating the effects of BHB analysis on the number of deaths by DKA (diabetes ketoacidosis), AKA (alcoholic ketoacidosis), HHS (hyperosmolar hyperglycaemic state), hypothermia, diabetes, alcoholism, and acidosis NOS (not otherwise specified). All 2900 deaths from 2013 through 2019 in which BHB was analysed at the National Board of Forensic Medicine, and 1069 DKA, AKA, HHS, hypothermia, diabetes, alcoholism, and acidosis cases without BHB analysis were included. The prevalence of BHB-positive cases for each cause of death, and trends and proportions of different BHB concentrations, were investigated. The number of BHB analyses/year increased from 13 to 1417. AKA increased from three to 66 and acidosis from one to 20. The deaths from alcoholism, DKA, and hypothermia remained stable. It is unclear why death from alcoholism remained stable while AKA increased. The increase in unspecific acidosis deaths raises the question why a more specific diagnosis had not been used. In conclusion, BHB analysis is instrumental in detecting AKA and acidosis. The scientific basis for the diagnosis of DKA and hypothermia improved, but the number of cases did not change.
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| 3. |
- Benulic, Kajsa-Stina
(författare)
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A Beef with Meat : Media and Audience Framings of Environmentally Unsustainable Production and Consumption
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this thesis is to identify potential routes of participation in environmentally sustainable changes of the Swedish meat production and consumption. Changes are needed as meat production and consumption have been linked to serious environmental problems, such as climate change, biodiversity loss, and land use change. Scientists, international organizations, and Swedish government authorities have identified individual consumer responsibility as key in making that change happen. The public is to be informed and educated to make more environmentally sustainable choices as meat consumers, and become more supportive of policy instruments. This strategy, which mirrors the dominant approach to solving environmental problems, is suggested by government authorities despite their suspicion that media should have made most Swedes aware of the environmental impacts of meat.In this thesis potential participatory routes are identified through the analysis of Swedish news media and audience framings of meat production and consumption. Media framing is studied as an important source of information, and perhaps motivation, crucial in the individualized consumer responsibility approach. The media framing is studied through content analysis of mainstream and alternative radical newspapers. The audiences’ framing of meat may be influenced by media, but also by their everyday experiences, beliefs, values, and opinions. Focus group discussions with reception elements are the methods used for studying how audiences frame meat and use media in the process. The concept of participation is broadened to include passive and active forms to capture in which roles individuals consider to contribute to changing meat production and consumption. It is not self-evident that routes to change must include individual participation, since responsibility may be attributed to other actors, both by media and their audiences.The results imply only participatory route supported by media and audience framing. It is the one that mirrors the individualized consumer responsibility approach to solving environmental problems. The major barrier to the route is the audiences’ perceived inability to act. In an alternative route supported by both media and audience framing, state centered actors are made responsible for enforcing change. Here, the major barrier is the perceived unlikeliness of powerful actors assuming responsibility. Audiences construct no citizen roles for themselves to participate in. Neither does media, who only address audiences as consumers. Based on these findings it is suggested that the outlook for the individualized responsibility approach to making meat production and consumption environmentally sustainable is gloomy. At least if it the approach is to continuously rely on the information and motivation offered by media.
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| 4. |
- Betsholtz, Alexander, et al.
(författare)
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Sewage sludge-based activated carbon – Production and potential in wastewater and stormwater treatment
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- SummarySustainable sewage sludge management has been a heavily debated topic in Europe for more than a decade. Due to its content of pollutants such as heavy metals, pharmaceuticals and other organic micropollutants, the use of sewage sludge for farmland application is currently banned or restricted in most European countries. Therefore, alternative methods for sludge management are discussed. The production of sludge-based activated carbon (SBAC) from digested sewage sludge is an alternative that would make use of problematic waste—sewage sludge—to produce a potentially valuable adsorbent. In this study, SBAC has been reviewed based on its potential use as an adsorbent for pollutants in wastewater and stormwater. The study consists of a literature review targeting (i) different methods for SBAC production, (ii) the influence of the production methods on the physical and chemical properties of the activated carbons and (iii) the importance of physical and chemical carbon properties on the adsorption of various types of pollutants in aquatic solutions. In connection to the literature study, SBAC was produced in the laboratory using a one-step steam activation method in order to study how various production parameters, such as pyrolysis temperature and steam oxidation, affect the porosity development of SBAC. The porosity of the carbon was assessed using N2adsorption and desorption isotherms at 77 K. Several combinations of the decisive parameters at various levels were tested and consequently the steam activated SBAC with highest volume of micropores (and highest specific surface area) was selected and tested for the adsorption of chemical oxygen demand (COD) and inorganic nutrients (NH4+, NO3-and PO43-) in wastewater from Källby WWTP in Lund, Sweden. As a reference, the SBAC was compared with a commercial activated carbon (CAC), Norit Sae Super (from Cabot), with a BET surface area of 975 m2/g. The results from existing literature show that SBAC, due to their high inorganic content, in general exhibit low micropore volumes compared to CAC, and therefore also tend to have a lower adsorption potential for small organic substances. However, the larger pores of the SBAC might be advantageous for adsorption of large organic pollutants such as dyes. In addition, the inorganic content of SBAC may contribute to the adsorption of charged and/or hydrophilic substances that are adsorbed through chemical interactions with surface functional groups of the carbon, rather than by physical adsorption to the core carbon structure. With respect to SBAC production, both feedstock type (e.g. biological sludge vs. chemical sludge) and production method (chemical vs. physical activation) have large influence on the properties of the carbon. In general, chemical activation using strong acids or based tend to generate SBAC with higher micropore volumes and abundance of surface functional groups compared to physical activation methods (such as steam activation), although its applicability can be questioned due to the large required input of chemicals. The result from the laboratory studies show that steam activated SBAC with BET surface areas of up to 162 m2/g could be generated using one-step steam activation at 800 °C for 30 minutes, although activation parameters were not optimized with respect to maximum surface area generation. The adsorption experiments showed that CAC was much better at adsorbing COD in effluent wastewater compared to the steam activated SBAC produced in lab, especially at low carbon concentrations. The experiments further showed that neither CAC nor SBAC was successful in adsorbing large quantities of inorganic nutrients (NH4+, NO3-and PO43-), probably due to lack of charged surface functional groups. Much work remains in order to demonstrate large scale production of SBAC in order to evaluate the economic feasibility of the process. In connection, more work is needed to understand how to maximize the potential of SBAC for the uptake of specific substances such as heavy metals or hydrophilic micropollutants.
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| 5. |
- Chen, Miaoxiang, 1962-, et al.
(författare)
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1 micron wavelength photo- and electroluminescence from a conjugated polymer
- 2004
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 84:18, s. 3570-3572
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Tidskriftsartikel (refereegranskat)abstract
- We report photo- and electroluminescence from an alternating conjugated polymer consisting of fluorene units and low-band gap donor-acceptor-donor (D-A-D) units. The D-A-D segment includes two electron-donating thiophene rings combined with a thiadiazolo-quinoxaline unit, which is electron withdrawing to its nature. The resulting polymer is conjugated and has a band gap of 1.27 eV. The corresponding electro- and photoluminescence spectra both peak at approximately 1 mum. Light-emitting diodes, based on a single layer of the polymer, demonstrated external quantum efficiencies from 0.03% to 0.05%.
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| 6. |
- Chen, Miaoxiang, et al.
(författare)
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Low band gap donor–acceptor–donor polymers for infra-red electroluminescence and transistors
- 2004
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Ingår i: Synthetic metals. - : Elsevier BV. - 0379-6779 .- 1879-3290. ; 146:3, s. 233-236
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Tidskriftsartikel (refereegranskat)abstract
- We report on transistors and light-emitting diodes using a conjugated polymer consisting of alternated segments of fluorene units and low-band gap donor–acceptor–donor (D–A–D) units. The D–A–D segment includes two electron-donating thiophene rings combined with a thiadiazolo-quinoxaline unit, which is electron withdrawing to its nature. The resulting polymer is conjugated and has a band gap of around 1.27 eV. Here we present the corresponding electro- and photoluminescence spectra, which both peak at approximately 1 μm. Single layer light-emitting diodes demonstrated external quantum efficiencies from 0.03% to 0.05%. The polymer was employed as active material in thin film transistors, a field-effect mobility of 3 × 10−3 cm2/V s and current on/off ratio of 104 were achieved at ambient atmosphere.
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| 7. |
- Cornell Kärnekull, Stina, et al.
(författare)
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Affected by Smells? : Environmental Chemical Responsivity Predicts Odor Perception
- 2011
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Ingår i: Chemical Senses. - Oxford : Oxford University Press. - 0379-864X .- 1464-3553. ; 36:7, s. 641-648
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Tidskriftsartikel (refereegranskat)abstract
- Strong negative reactions, physical symptoms, and behavioral disruptions due to environmental odors are common in the adult population. We investigated relationships among such environmental chemosensory responsivity (CR), personality traits, affective states, and odor perception. Study 1 showed that CR and neuroticism were positively correlated in a sample of young adults (n = 101), suggesting that persons high in neuroticism respond more negatively to environmental odors. Study 2 explored the relationships among CR, noise responsivity (NR), neuroticism, and odor perception (i.e., pleasantness and intensity) in a subset of participants (n = 40). High CR was associated with high NR. Regression analyses indicated that high CR predicted higher odor intensity ratings and low olfactory threshold (high sensitivity) predicted lower pleasantness ratings. However, neuroticism was not directly associated with odor ratings or thresholds. Overall, the results suggest that CR and odor thresholds predict perceptual ratings of odors and that high CR is associated with nonchemosensory affective traits.
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| 8. |
- Cornell Kärnekull, Stina, 1985-
(författare)
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Auditory and Olfactory Abilities in Blind and Sighted Individuals : More Similarities than Differences
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Blind individuals face various challenges in everyday life because of the lack of visual input. However, since they need to rely on the non-visual senses for everyday tasks, for instance, when navigating the environment, the question has been raised as to whether perceptual and cognitive abilities in these senses may be enhanced. This question has mainly been addressed for auditory and tactile abilities, whereas there is considerably less research into the chemical senses, such as olfaction. However, to determine whether blindness has general effects, different senses and types of tasks should be studied, preferably in one and the same study. Therefore, throughout this thesis, analogous auditory and olfactory tasks that varied in cognitive complexity were studied. In Study I, absolute thresholds, discrimination, identification, episodic recognition (i.e., after a short retention interval), metacognition, and self-reported imagery ability were assessed in early blind, late blind, and sighted participants. The only objective measure on which the blind and sighted clearly differed was the auditory episodic recognition task. The fact that early blind but not late blind participants displayed better memory than the sighted suggested that the onset age of blindness may be important for whether this ability becomes enhanced following blindness. Furthermore, the early blind participants rated their auditory imagery ability higher than the sighted, whereas both early and late blind participants rated their olfactory imagery ability higher than the sighted. In Study II, the participants from Study I were followed up after more than a year and retested on auditory and olfactory episodic recognition and identification. This time, the early blind displayed no advantage over the sighted, suggesting that the influence of blindness on auditory memory may be modulated by the length of the retention interval. Moreover, in line with Study I, identification of sounds and odors was similar in the three groups. In Study III, early blind and sighted participants were examined for potential differences in autobiographical memory as evoked by sounds and odors, respectively. Blindness did not influence the reminiscence bumps (i.e., memory peaks in certain age intervals) or have any clear impact on the number of retrieved sound- or odor-evoked memories. Taken together, the present findings indicate that blindness has no general influence across tasks or sensory modalities. Rather, specific auditory abilities, such as episodic memory, may be enhanced in blind individuals, although such effects may depend on both the onset age of blindness and the length of the retention interval. In conclusion, for most perceptual and cognitive abilities examined, performance seemed unaffected by blindness.
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| 9. |
- Cornell Kärnekull, Stina, et al.
(författare)
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Long-Term Memory for Odors : Influences of Familiarity and Identification Across 64 Days
- 2015
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Ingår i: Chemical Senses. - : Oxford University Press (OUP). - 0379-864X .- 1464-3553. ; 40:4, s. 259-267
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Tidskriftsartikel (refereegranskat)abstract
- Few studies have investigated long-term odor recognition memory, although some early observations suggested that the forgetting rate of olfactory representations is slower than for other sensory modalities. This study investigated recognition memory across 64 days for high and low familiar odors and faces. Memory was assessed in 83 young participants at 4 occasions; immediate, 4, 16, and 64 days after encoding. The results indicated significant forgetting for odors and faces across the 64 days. The forgetting functions for the 2 modalities were not fundamentally different. Moreover, high familiar odors and faces were better remembered than low familiar ones, indicating an important role of semantic knowledge on recognition proficiency for both modalities. Although odor recognition was significantly better than chance at the 64 days testing, memory for the low familiar odors was relatively poor. Also, the results indicated that odor identification consistency across sessions, irrespective of accuracy, was positively related to successful recognition.
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| 10. |
- Cornell Kärnekull, Stina, 1985-, et al.
(författare)
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The reminiscence bump is blind to blindness : Evidence from sound- and odor-evoked autobiographical memory
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Autobiographical memories (AMs) evoked by sensory cues, such as words, pictures, and sounds, typically form reminiscence bumps in adolescence and young adulthood. However, odors constitute an exception by shifting the bump to early childhood. Olfaction may be a “sense of first impressions”, as indicated by a unique hippocampal representation in the brain for first odor-to-object associations. However, the influence of the individual’s sensory function on AMs has never been examined. We examined the reminiscence bumps of sound- and odor-evoked memories of early-blind and sighted individuals, since blindness implies considerable changes in sensory experience. Despite such changes, the groups displayed similar age distributions of both sound- and odor-evoked memories. The auditory bump seemed to span the first two decades of life, whereas the olfactory bump was once again found in early childhood. Hence, the reminiscence bumps were robust to differences in sensory function and experience.
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| 11. |
- Cornell Kärnekull, Stina, et al.
(författare)
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The reminiscence bump is blind to blindness : Evidence from sound- and odor-evoked autobiographical memory
- 2020
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Ingår i: Consciousness and Cognition. - : Elsevier BV. - 1053-8100 .- 1090-2376. ; 78
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Tidskriftsartikel (refereegranskat)abstract
- The reminiscence bump is the disproportionally high reporting of autobiographical memories from adolescence and early adulthood and is typically observed when memories are evoked by cues, such as words, pictures, and sounds. However, when odors are used the bump shifts to early childhood. Although these findings indicate that sensory modality affects the bump, the influence of the individual's sensory function on the reminiscence bumps is unknown. We examined the reminiscence bumps of sound- and odor-evoked autobiographical memories of early blind and sighted individuals, since early blindness implies considerable effects on sensory experience. Despite differences in sensory experience between blind and sighted individuals, the groups displayed similar age distributions of both sound- and odor-evoked memories. The auditory bump spanned the first two decades of life, whereas the olfactory bump was once again found in early childhood. These results demonstrate that the reminiscence bumps are robust to fundamental differences in sensory experience.
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| 12. |
- de Jong, Michel P, 1970-, et al.
(författare)
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Orbital-specific dynamic charge transfer from Fe(II)-tetraphenylporphyrin molecules to molybdenum disulfide substrates
- 2005
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 72:3, s. 35448-
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Tidskriftsartikel (refereegranskat)abstract
- Orbital-specific femtosecond charge transfer dynamics between Fe(II)-tetraphenylporphyrin molecules and semimetallic molybdenum disulfide substrates is investigated using core-level resonant photoemission spectroscopy. The electronic coupling to the substrate and the efficiency of charge transport across the interface is found to be different for the individual molecular electronic subsystems. In particular, electrons excited at the phenyl substituents are transferred within 3–6 fs, while hopping from the porphyrin ring is slower than 30 fs.
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| 13. |
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| 14. |
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| 15. |
- Friedlein, Rainer, et al.
(författare)
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Electronic structure of highly ordered films of self-assembled graphitic nanocolumns
- 2003
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 68:19, s. 195414-
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Tidskriftsartikel (refereegranskat)abstract
- Highly ordered, several nanometers thick films of alkylated large planar, polycyclic aromatic hydrocarbon (PAH) molecules have been grown on semi-metallic molybdenum disulfide substrates. The films are characterized by a two-dimensional lateral arrangement of columns standing at the surface on a macroscopic scale. The self-assembly of such insulated columns of face-to-face disks with surface-induced vertical alignment has been achieved directly from solution processing. Angle-resolved photoelectron spectra revealed a highly anisotropic quasi-one-dimensional electronic structure with an extended π-electronic wave function. An intermolecular dispersion of the highest occupied band of at least 0.15 eV along the stacking direction has been measured. A partial breakdown of the concept of quasimomentum due to the finite size of the nano-objects perpendicular to the stacks is observed.
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| 16. |
- Friling, Stina, et al.
(författare)
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Efficient production of mesencephalic dopamine neurons by Lmx1a expression in embryonic stem cells
- 2009
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Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 106:18, s. 7613-7618
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Tidskriftsartikel (refereegranskat)abstract
- Signaling factors involved in CNS development have been used to control the differentiation of embryonic stem cells (ESCs) into mesencephalic dopamine (mesDA) neurons, but tend to generate a limited yield of desired cell type. Here we show that forced expression of Lmx1a, a transcription factor functioning as a determinant of mesDA neurons during embryogenesis, effectively can promote the generation of mesDA neurons from mouse and human ESCs. Under permissive culture conditions, 75%-95% of mouse ESC-derived neurons express molecular and physiological properties characteristic of bona fide mesDA neurons. Similar to primary mesDA neurons, these cells integrate and innervate the striatum of 6-hydroxy dopamine lesioned neonatal rats. Thus, the enriched generation of functional mesDA neurons by forced expression of Lmx1a may be of future importance in cell replacement therapy of Parkinson disease.
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| 17. |
- Holst, Martina, et al.
(författare)
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Molecular mechanisms underlying N1, N11-diethylnorspermine-induced apoptosis in a human breast cancer cell line.
- 2008
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Ingår i: Anti-Cancer Drugs. - 0959-4973. ; 19:9, s. 871-883
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Tidskriftsartikel (refereegranskat)abstract
- Polyamine analogue treatment results in growth inhibition and sometimes in cell death. Therefore, polyamine analogues are considered in the treatment of cancer; however, the cellular properties that govern sensitivity are not known. The objective of this study was to elucidate molecular mechanisms behind apoptosis induced by the polyamine analogue N, N-diethylnorspermine (DENSPM). Four different breast cancer cell lines were treated with DENSPM. Cell death was evaluated with flow cytometry and a caspase 3 assay. The levels of a number of proapoptotic and antiapoptotic proteins in subcellular compartments were evaluated with western blot. In the most sensitive cell line, DENSPM treatment induced the release of cytochrome c from mitochondria, resulting in activation of caspase 3 but without decreasing the mitochondrial transmembrane potential. However, in the three other cell lines DENSPM treatment did not induce extensive cell death. This is partly explained by the high levels of antiapoptotic proteins Bcl-2 and Bad and low levels of proapoptotic proteins Bax and procaspase 3 in these three cell lines. The results are also partly explained by the degree of activation of the catabolic enzyme spermidine/spermine-N-acetyltransferase and polyamine pool reduction achieved by DENSPM treatment. Our results show that the protein profile of proapoptotic and antiapoptotic proteins may contribute to the outcome to treatment with the polyamine analogue DENSPM. The results also indicate that it should be possible to find molecular markers for sensitivity to DENSPM that could be used in the clinic to predict sensitivity to a polyamine analogue.
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| 18. |
- Johansson, Erik M .J., et al.
(författare)
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Interfacial properties of photovoltaic TiO2/dye/PEDOT-PSS heterojunctions
- 2005
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Ingår i: Synthetic metals. - : Elsevier BV. - 0379-6779 .- 1879-3290. ; 149:03-feb, s. 157-167
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Tidskriftsartikel (refereegranskat)abstract
- Systems comprising a dense TiO2 film electrode, a ruthenium polypyridine dye and a PEDOT-PSS (poly(3,4-ethylenedioxythiophene)-poly(4-styrenesulphonate)) film were prepared. The heterojunctions were shown to have photovoltaic properties, with the dye absorbing the light, the TiO2 acting as an electron conducting material and PEDOT-PSS acting as a hole transport material. A series of dyes was used to investigate their influence on the photocurrent and the photovoltage characteristics of the heterojunction. These results were compared to a photoelectrochemical system in which the PEDOT-PSS was replaced by a liquid electrolyte containing triiodide/iodide redox-couple. Photoelectron spectroscopy (PES) was used to monitor the interfacial properties of the heterojunction and the investigation points out effects of importance when assembling the materials together to a functional unit. Specifically, it was concluded that the interaction with the dye clearly affects the structure of PEDOT-PSS, both with respect to the surface composition of PSS relative to PEDOT and with respect to the chemical state of the sulphur in the polymers. Moreover, a comparison of the Ru3d and the valence band spectra of the two different interfaces (dye/TiO2 and dye/PEDOT-PSS) indicates that the energy level structure of the dyes compared to the substrate is different for the two surfaces. Thus, in the combined energy level picture under dark conditions, the energy levels in TiO2 relative to the energy levels in PEDOT-PSS depend on the dye.
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| 19. |
- Johansson, Veronica, et al.
(författare)
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Effect of polyamine deficiency on proteins involved in Okazaki fragment maturation.
- 2008
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Ingår i: Cell Biology International. - : Wiley. - 1095-8355 .- 1065-6995. ; 32, s. 1467-1477
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Tidskriftsartikel (refereegranskat)abstract
- Polyamine depletion causes S phase prolongation, and earlier studies indicate that the elongation step of DNA replication is affected. This led us to investigate the effects of polyamine depletion on enzymes crucial for Okazaki fragment maturation in the two breast cancer cell lines MCF-7 and L56Br-C1. In MCF-7 cells, treatment with N(1),N(11)-diethylnorspermine (DENSPM) causes S phase prolongation. In L56Br-C1 cells the prolongation is followed by massive apoptosis. In the present study we show that L56Br-C1 cells have substantially lower basal expressions of two Okazaki fragment maturation key proteins, DNA ligase I and FEN1, than MCF-7 cells. Thus, these two proteins might be promising markers for prediction of polyamine depletion sensitivity, something that can be useful for cancer treatment with polyamine analogues. DENSPM treatment affects the cellular distribution of FEN1 in L56Br-C1 cells, but not in MCF-7 cells, implying that FEN1 is affected by or involved in DENSPM-induced apoptosis.
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| 20. |
- Jönsson, Christina, et al.
(författare)
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Asymmetric Catalysis in a Micro Reactor : Ce, Yb and Lu Catalysed Enantioselective Addition of Trimethylsilyl Cyanide to Benzaldehyde
- 2004
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Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020 .- 1464-5416. ; 60:46, s. 10515-10520
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Tidskriftsartikel (refereegranskat)abstract
- A T-shaped micro reactor was used for the optimisation of reaction conditions for the enantioselective silyleyanation of benzaldehyde catalysed by lanthanide-pybox complexes. Compared to a conventional batch procedure, higher conversion was observed within shorter reaction time. The micro reactor process involving Lu(III) afforded essentially the same enantioselectivity as the batch process (73 vs 76% ee), whereas the enantioselectivity was lower in the micro reactor for catalysts containing Yb(III) (53 compared to 72%). Ce(III) provided very low selectivity in both types of processes (1 and 11 % ee, respectively). A study of the effect of additives showed that the enantioselectivity in the Yb catalysed reaction performed in the micro reactor could be increased to 66%, whereas only a minor improvement, to 78% ee, was observed in the reaction with Lu.
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| 21. |
- Jönsson, Göran B, et al.
(författare)
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High-resolution genomic profiles of breast cancer cell lines assessed by tiling BAC array comparative genomic hybridization.
- 2007
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Ingår i: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 46:6, s. 543-558
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Tidskriftsartikel (refereegranskat)abstract
- A BAC-array platform for comparative genomic hybridization was constructed from a library of 32,433 clones providing complete genome coverage, and evaluated by screening for DNA copy number changes in 10 breast cancer cell lines (BT474, MCF7, HCC1937, SK-BR-3, L56Br-C1, ZR-75-1, JIMTI, MDA-MB-231, MDA-MB-361, and HCC2218) and one cell line derived from fibrocystic disease of the breast (MCF10A). These were also characterized by gene expression analysis and found to represent all five recently described breast cancer subtypes using the '' intrinsic gene set '' and centroid correlation. Three cell lines, HCC 1937 and L56BrC1 derived from BRCA I mutation carriers and MDA-MB-23 1, were of basal-like subtype and characterized by a high frequency of low-level gains and losses of typical pattern, including limited deletions on Sq. Four estrogen receptor positive cell lines were of luminal A subtype and characterized by a different pattern of aberrations and high-level amplifications, including ERBB2 and other 17q amplicons in BT474 and MDA-MB-361. SK-BR-3 cells, characterized by a complex genome including ERBB2 amplification, massive high-level amplifications on 8q and a homozygous deletion of CDH1 at 16q22, had an expression signature closest to luminal B subtype. The effects of gene amplifications were verified by gene expression analysis to distinguish targeted genes from silent amplicon passengers. JIMT1, derived from an ERBB2 amplified trastuzumab resistant tumor, was of the ERBB2 subtype. Homozygous deletions included other known targets such as PTEN (HCC1937) and CDKN2A (MDA-MB-231, MCF10A), but also new candidate suppressor genes such as FUSSEL18 (HCC1937) and WDR11 (L56Br-C1) as well as regions without known genes. The tiling BAC-arrays constitute a powerful tool for high-resolution genomic profiling suitable for cancer research and clinical diagnostics.
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| 22. |
- Jönsson, Stina, et al.
(författare)
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Electronic structure of novel low band gap conjugated polymers
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The electronic structures of two novel low band gap conjugated polymers have been studied. Both materials are conjugated alternating copolymers based on fluorene units and low band gap donor-acceptor-donor units. The emphasis in this study has been to study the valence and the conduction bands. In particular the degree of localization or delocalization along the polymers and the symmetry of these states have been studied, since these features can be related to their transport properties. The main experimental part of this work is photoelectron spectroscopy, near-edge X-ray photon absorption and resonant photoemission. These techniques have been used to probe the frontier electronic structure of these systems. The experimental results are interpreted with the help of density functional theory calculations. The valence bands are dispersed originating from orbitals delocalized along the polymer chain shile the conduction bands are more flat, as they are derived from orbitals localized on the acceptor units. This band structure would predict good hole transporting properties but poor electron transport.
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| 23. |
- Jönsson, Stina Karin Maria, 1975-
(författare)
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XPS studies of an organic anode and hole-conductor system : PEDOT-PSS
- 2002
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis deals with photoelectron spectroscopy of conducting polymer systems. A particular system, poly(3,4-ethylenedioxythiophene) polystyrenesulfonic acid (PEDOT-PSS), has been the main focus of this work. It is an aqueous colloidal dispersion consisting of doped conjugated polymer PEDOT with counter ions provided by the PSS chains. PEDOT PSS films have previously proven to have a grain-like structure in which the grains have a ~30 Å thick insulating PSS outermost layer. The conductivity of thin PEDOT-PSS films has been improved through adding some high-boiling-point solvents to the PEDOT-PSS blend. With the help of atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and electron spectroscopy for chemical analysis based photon energy depth profiling (ESCAPEDEPF) measurements the reason for this increase has been explained. The major reason is a rearrangement of the morphology, in terms of an increase in the PEDOT to-PSS ratio in the surface region (i.e. the insulating PPS layer is decreased for each grain). The interface of PEDOT-PSS with aluminum (for contacting purposes) has also been studied with XPS and ultraviolet photoelectron spectroscopy (UPS). Due to the many components in the PEDOT-PSS film its reactions with aluminum was difficult to deduce. Therefore the aluminum interfaces with model molecules of each of the components of PEDOT-PSS were investigated to discern this. Phenyl capped EDOT-trimer was used as a model oligomer for neutral PEDOT. It has been shown that aluminum preferentially internets and forms covalent bonds with C-S carbons that causes a rearrangement of the charge density within the oligomer and breaks the n-conjugation. In PEDOT-PSS blends the PEDOT part is left intact and aluminum preferentially reacts with the SO-3 H+ and/or so-3 species of the PSS part. In order to deduce this the model systems PSSH, benzenesulfonic acid and sodium benzenesulfonate were studied. Sodium benzenesulfonate was used to model the PSS-Na+ contamination present in the polymer blend. The fact that aluminum does not internet with PEDOT avoids any break in the conjugation in the system, but it can however lead to dedoping of the PEDOT chains, therefore negatively affecting the mobility in the material and the charge transport across the PEDOT PSS/aluminum interface.
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| 24. |
- Jönsson, Stina, et al.
(författare)
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Phenyl-capped EDOT trimer : its chemical and electronic structure and its interface with aluminum
- 2003
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 107:39, s. 10793-10800
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Tidskriftsartikel (refereegranskat)abstract
- The chemical and electronic properties of a phenyl-capped 3,4-(ethylenedioxy)thiophene trimer (EDOT trimer) and its interface formation with aluminum have been studied. Thin EDOT trimer films were prepared on clean gold substrates through in-situ vapor deposition. Aluminum was deposited stepwise on top of the EDOT trimer, and the initial stages of interface formation were investigated by photoelectron spectroscopy. The organic/metal interface formed was not completely abrupt; some degree of diffusion of aluminum into the EDOT trimer film occurred. The aluminum atoms preferentially react with the α-position of the trimer (C−S carbon atoms) forming covalent bonds. The formation of these covalent bonds causes a break in the π-conjugation of the system due to the introduction of sp3 defects. The charge density also is somewhat redistributed within the oligomer as a whole, mainly affecting the neighboring atoms: sulfur and β-position of the trimer (C=C−O carbon atoms). Once the C−S carbon sites are saturated, the aluminum instead reacts with the less favorable carbon atom of the ethylene bridge (C−O−C carbons). Worth noting is the decrease in work function from 5.2 eV for sputter cleaned gold to 4.1 eV upon deposition of the EDOT trimer. Our results have several implications for organic electronics. The sp3 defects introduced by the aluminum−EDOT contacting will influence the charge injection into the material across the EDOT trimer/aluminum interface negatively. The change in work function could potentially be used to modify gold contacts for electron injection into molecules with low electron affinity.
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| 25. |
- Jönsson, Stina, et al.
(författare)
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Photoelectron spectroscopy of the contact between the cathode and the active layers in plastic solar cells : the role of LiF
- 2005
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Ingår i: Japanese Journal of Applied Physics. - 0021-4922 .- 1347-4065. ; 44:6A, s. 3695-3701
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Tidskriftsartikel (refereegranskat)abstract
- The surfaces and electrode interfaces of a polymer blend used in prototype solar cells have been characterized with photoelectron spectroscopy. The polymer blend in question is a 1:4 mixture of APFO-3:PCBM. Based on surface analysis of the pristine film we can conclude that the surface of the blend is a 1:1 mixture of APFO-3 and PCBM. The electrode systems studied are the widely used Al and Al/LiF contacts. LiF prevents formation at the Al/organic interface of Al-organic complexes that destroy the π-conjugation. In addition to this, there are two other beneficial, thickness dependent, effects. Decomposition of LiF occurs for thin enough layers in which the LiF species are in contact with both the organic film and the Al atoms, which creates a low workfunction contact. For thicker (multi)layers, the dipole formed at the LiF/organic interface is retained as no decomposition of the LiF occurs upon Al deposition.
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