| 1. |
- Alenius Dahlqvist, Jenny, 1972-, et al.
(author)
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Pacemaker treatment after Fontan surgery-A Swedish national study
- 2019
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In: Congenital Heart Disease. - : Computers, Materials and Continua (Tech Science Press). - 1747-079X .- 1747-0803. ; 14:4, s. 582-589
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Journal article (peer-reviewed)abstract
- ObjectiveFontan surgery is performed in children with univentricular heart defects. Previous data regarding permanent pacemaker implantation frequency and indications in Fontan patients are limited and conflicting. We examined the prevalence of and risk factors for pacemaker treatment in a consecutive national cohort of patients after Fontan surgery in Sweden. MethodsWe retrospectively reviewed all Swedish patients who underwent Fontan surgery from 1982 to 2017 (n=599). ResultsAfter a mean follow-up of 12.2years, 13% (78/599) of the patients with Fontan circulation had received pacemakers. Patients operated with the extracardiac conduit (EC) type of total cavopulmonary connection had a significantly lower prevalence of pacemaker implantation (6%) than patients with lateral tunnel (LT; 17%). Mortality did not differ between patients with (8%) and without pacemaker (5%). The most common pacemaker indication was sinus node dysfunction (SND) (64%). Pacemaker implantation due to SND was less common among patients with EC. Pacemaker implantation was significantly more common in patients with mitral atresia (MA; 44%), double outlet right ventricle (DORV; 24%) and double inlet left ventricle (DILV; 20%). In contrast, patients with pulmonary atresia with intact ventricular septum and hypoplastic left heart syndrome were significantly less likely to receive a pacemaker (3% and 6%, respectively). ConclusionsThirteen percent of Fontan patients received a permanent pacemaker, most frequently due to SND. EC was associated with a significantly lower prevalence of pacemaker than LT. Permanent pacemaker was more common in patients with MA, DORV, and DILV.
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| 2. |
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| 3. |
- Alenius Dahlqvist, Jenny, 1972-, et al.
(author)
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Sinus node dysfunction in patients with Fontan circulation: could heart rate variability be a predictor for pacemaker implantation?
- 2019
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In: Pediatric Cardiology. - : Springer Science and Business Media LLC. - 0172-0643 .- 1432-1971. ; 40:4, s. 685-693
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Journal article (peer-reviewed)abstract
- Sinus node dysfunction (SND) causes significant morbidity in patients after Fontan surgery. Heart rate variability (HRV) reflects the autonomic regulation of the heart, and changes in HRV have been associated with SND in adults. We aimed to study whether changes in HRV could be detected in 24-h electrocardiographic (ECG) recordings in Fontan patients with SND. We compared HRV results from two patient groups; patients with Fontan circulation who later required a pacemaker due to severe SND (n = 12) and patients with Fontan circulation and SND, without indication for pacemaker treatment (n = 11), with two control groups; patients with Fontan circulation without SND (n = 90) and healthy controls (n = 66). The Poincare plot index SD2 (representing changes in heart rate over 24-h) and the very low-frequency (VLF) HRV component were significantly higher in both SND groups, both compared with healthy controls and patients with Fontan circulation without SND. In SND patients with pacemakers, SD2 and VLF were slightly reduced compared to SND patients without pacemaker (p = 0.06). In conclusion, in Fontan patients with SND the HRV is significantly higher compared to healthy controls and Fontan patients without SND. However, in patients with severe SND requiring pacemaker, SD2 and VLF tended to be lower than in patients with SND without pacemaker, which could indicate a reduced diurnal HRV in addition to the severe bradycardia. This is a small study, but our results indicate that HRV analysis might be a useful method in the follow-up of Fontan patients regarding development of SND.
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| 4. |
- Andersson, Claes, et al.
(author)
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Mebendazole is unique among tubulin-active drugs in activating the MEK-ERK pathway
- 2020
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
-
Journal article (peer-reviewed)abstract
- We recently showed that the anti-helminthic compound mebendazole (MBZ) has immunomodulating activity in monocyte/macrophage models and induces ERK signalling. In the present study we investigated whether MBZ induced ERK activation is shared by other tubulin binding agents (TBAs) and if it is observable also in other human cell types. Curated gene signatures for a panel of TBAs in the LINCS Connectivity Map (CMap) database showed a unique strong negative correlation of MBZ with MEK/ERK inhibitors indicating ERK activation also in non-haematological cell lines. L1000 gene expression signatures for MBZ treated THP-1 monocytes also connected negatively to MEK inhibitors. MEK/ERK phosphoprotein activity testing of a number of TBAs showed that only MBZ increased the activity in both THP-1 monocytes and PMA differentiated macrophages. Distal effects on ERK phosphorylation of the substrate P90RSK and release of IL1B followed the same pattern. The effect of MBZ on MEK/ERK phosphorylation was inhibited by RAF/MEK/ERK inhibitors in THP-1 models, CD3/IL2 stimulated PBMCs and a MAPK reporter HEK-293 cell line. MBZ was also shown to increase ERK activity in CD4+ T-cells from lupus patients with known defective ERK signalling. Given these mechanistic features MBZ is suggested suitable for treatment of diseases characterized by defective ERK signalling, notably difficult to treat autoimmune diseases.
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| 5. |
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| 6. |
- Blom, Kristin, et al.
(author)
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Mebendazole-induced M1 polarisation of THP-1 macrophages may involve DYRK1B inhibition
- 2019
-
In: BMC Research Notes. - : Springer Nature. - 1756-0500. ; 12:1
-
Journal article (peer-reviewed)abstract
- Objective: We recently showed that the anti-helminthic compound mebendazole (MBZ) has immunomodulating activity by inducing a M2 to M1 phenotype switch in monocyte/macrophage models. In the present study we investigated the potential role of protein kinases in mediating this effect.Results: MBZ potently binds and inhibits Dual specificity tyrosine-phosphorylation-regulated kinase 1B (DYRK1B) with a Kd and an IC50 of 7 and 360 nM, respectively. The specific DYRK1B inhibitor AZ191 did not mimic the cytokine release profile of MBZ in untreated THP-1 monocytes. However, in THP-1 cells differentiated into macrophages, AZ191 strongly induced a pro-inflammatory cytokine release pattern similar to MBZ and LPS/IFNγ. Furthermore, like MBZ, AZ191 increased the expression of the M1 marker CD80 and decreased the M2 marker CD163 in THP-1 macrophages. In this model, AZ191 also increased phospho-ERK activity although to a lesser extent compared to MBZ. Taken together, the results demonstrate that DYRK1B inhibition could, at least partly, recapitulate immune responses induced by MBZ. Hence, DYRK1B inhibition induced by MBZ may be part of the mechanism of action to switch M2 to M1 macrophages.
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| 7. |
- Blom, Kristin, et al.
(author)
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The anticancer effect of mebendazole may be due to M1 monocyte/macrophage activation via ERK1/2 and TLR8-dependent inflammasome activation
- 2017
-
In: Immunopharmacology and immunotoxicology. - : Informa UK Limited. - 0892-3973 .- 1532-2513. ; 39:4, s. 199-210
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Journal article (peer-reviewed)abstract
- Mebendazole (MBZ), a drug commonly used for helminitic infections, has recently gained substantial attention as a repositioning candidate for cancer treatment. However, the mechanism of action behind its anticancer activity remains unclear. To address this problem, we took advantage of the curated MBZ-induced gene expression signatures in the LINCS Connectivity Map (CMap) database. The analysis revealed strong negative correlation with MEK/ERK1/2 inhibitors. Moreover, several of the most upregulated genes in response to MBZ exposure were related to monocyte/macrophage activation. The MBZ-induced gene expression signature in the promyeloblastic HL-60 cell line was strongly enriched in genes involved in monocyte/macrophage pro-inflammatory (M1) activation. This was subsequently validated using MBZ-treated THP-1 monocytoid cells that demonstrated gene expression, surface markers and cytokine release characteristic of the M1 phenotype. At high concentrations MBZ substantially induced the release of IL-1 beta and this was further potentiated by lipopolysaccharide (LPS). At low MBZ concentrations, cotreatment with LPS was required for MBZ-stimulated IL-1 beta secretion to occur. Furthermore, we show that the activation of protein kinase C, ERK1/2 and NF-kappaB were required for MBZ-induced IL-1 release. MBZ-induced IL-1 release was found to be dependent on NLRP3 inflammasome activation and to involve TLR8 stimulation. Finally, MBZ induced tumor-suppressive effects in a coculture model with differentiated THP-1 macrophages and HT29 colon cancer cells. In summary, we report that MBZ induced a pro-inflammatory (M1) phenotype of monocytoid cells, which may, at least partly, explain MBZ's anticancer activity observed in animal tumor models and in the clinic.
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| 8. |
- Brackmann, Christian, et al.
(author)
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Laser-induced fluorescence of formaldehyde in combustion using third harmonic Nd : YAG laser excitation
- 2003
-
In: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. - 1386-1425. ; 59:14, s. 3347-3356
-
Journal article (peer-reviewed)abstract
- Formaldehyde (CH2O) is an important intermediate species in combustion processes and it can through laser-induced fluorescence measurements be used for instantaneous flame front detection. The present study has focussed on the use of the third harmonic of a Nd:YAG laser at 355 nm as excitation wavelength for formaldehyde, and different dimethyl ether (C2H6O) flames were used as sources of formaldehyde in the experiments. The investigations included studies of the overlap between the laser profile and the absorption lines of formaldehyde, saturation effects and the potential occurrence of laser-induced photochemistry. The technique was applied for detection of formaldehyde in an internal combustion engine operated both as a spark ignition engine and as a homogenous charge compression ignition engine. (C) 2003 Elsevier B.V. All rights reserved.
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| 9. |
- Chambi, Diego, et al.
(author)
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Production of Exopolysaccharides by Cultivation of Halotolerant Bacillus atrophaeus BU4 in Glucose- and Xylose-Based Synthetic Media and in Hydrolysates of Quinoa Stalks
- 2022
-
In: Fermentation. - : MDPI AG. - 2311-5637. ; 8:2
-
Journal article (peer-reviewed)abstract
- A halotolerant, exopolysaccharide-producing bacterium isolated from the Salar de Uyuni salt flat in Bolivia was identified as Bacillus atrophaeus using next-generation sequencing. Comparisons indicate that the genome most likely (p-value: 0.0024) belongs to a subspecies previously not represented in the database. The growth of the bacterial strain and its ability to produce exopolysaccharides (EPS) in synthetic media with glucose or xylose as carbon sources, and in hydrolysates of quinoa stalks, was investigated. The strain grew well in all synthetic media, but the growth in glucose was better than that in xylose. Sugar consumption was better when initial concentrations were low. The growth was good in enzymatically produced cellulosic hydrolysates but was inhibited in hemicellulosic hydrolysates produced using hydrothermal pretreatment. The EPS yields were up to 0.064 g/g on initial glucose and 0.047 g/g on initial xylose, and was higher in media with relatively low sugar concentrations. The EPS was isolated and purified by a sequential procedure including centrifugation, cold ethanol precipitation, trichloroacetic acid treatment, dialysis, and freeze-drying. Glucose and mannose were the main sugars identified in hydrolyzed EPS. The EPS was characterized by size-exclusion chromatography, Fourier-transform infrared (FTIR) spectroscopy, heteronuclear single-quantum coherence nuclear magnetic resonance (HSQC NMR) spectroscopy, scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis. No major differences were elucidated between EPS resulting from cultivations in glucose- or-xylose-based synthetic media, while some divergences with regard to molecular-weight averages and FTIR and HSQC NMR spectra were detected for EPS from hydrolysate-based media.
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| 10. |
- Collin, Robert, et al.
(author)
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Simultaneous OH- and Formaldehyde-LIF Measurements in an HCCI Engine
- 2003
-
In: SAE Transactions, Journal of Fuels and Lubricants. - 0096-736X. ; 112:4, s. 2479-2486
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Journal article (peer-reviewed)abstract
- Simultaneous OH- and formaldehyde LIF measurements have been performed in an HCCI engine using two laser sources working on 283 and 355 nm, respectively. Two ICCD camera systems, equipped with long-pass filters, were used to collect the LIF signals. The simultaneous images of OH and formaldehyde were compared with heat-release calculated from the pressure-trace matching the cycle for the LIF measurements. The measurements were performed on a 0.5-l, single-cylinder optical engine equipped with port-fuel injection system. A blend of iso-octane and n-heptane was used as fuel and the compression ratio was set to 12:1. The width of the laser sheet was 40 mm and hence covered approximately half of the cylinder bore. At some 20 CAD BTDC low temperature reactions are present and formaldehyde is formed. The formaldehyde signal is then rather constant until the main heat-release starts just before TDC, where the signal decreases rapidly to low values. From some 15 CAD to 5 CAD BTDC the formaldehyde is uniformly distributed in the imaged area. As formaldehyde decreases, OH increases and follows the main rate of heat release curve, though with a slight lag in phase. Thereafter OH is formed in the areas from which the formaldehyde has disappeared and the OH signal is present to some 20 CAD ATDC.
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| 11. |
- Collin, Robert, et al.
(author)
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Studies of the Combustion Process with Simultaneous OH- and Formaldehyde-PLIF in a Direct-Injected HCCI engine
- 2004
-
In: [Host publication title missing]. ; , s. 311-317
-
Conference paper (peer-reviewed)abstract
- To run a Diesel engine in Homogeneous Charge Compression Ignition (HCCI) mode has proved to be a highly promising approach towards reduced engine-out emissions of NOx and particulate matter. A crucial issue when utilizing HCCI is the degree of charge homogeneity that is required to achieve the desired low temperature combustion. A very well mixed charge can be created through the use of traditional port injection. This approach would most often result in low emissions of NOx and soot. However, this strategy might also see a penalty in the form of high levels of unburned hydrocarbons due to incomplete combustion, especially under low load conditions. A proposed solution to this is to utilize stratified charge in the lower load range. The creation of a stratified charge imposes no major problems in modern DI engines. The important parameter is the degree of stratification that can be tolerated. If the charge gets too highly stratified, the combustion will become more diesel-like with dramatically increased levels of NOx and soot as a result. This paper presents simultaneous laser based measurements of formaldehyde and OH-radical distributions in an HCCI engine. Formaldehyde is formed as an intermediate species when combusting hydrocarbons. The formation occurs through low temperature reactions in an early phase of the combustion process. Later in the process formaldehyde is being consumed. Formaldehyde is, therefore, used as indicator of the first stage of combustion and a marker of zones with low-temperature reactions. The OH radical is formed as an intermediate during the high temperature reactions, and is used as a marker of zones where the combustion is ongoing. The purpose of the investigation was to study how the combustion process is affected by the change in homogeneity that arises from early and late injection, respectively. A 0.5 liter single-cylinder optical engine equipped with a DI common rail fuel system was operated with a number of different injection timings, resulting in various levels of charge stratification. A blend of iso-octane and n-heptane was used as fuel. The measurement technique used was planar laser-induced fluorescence where formaldehyde was excited at 355nm and OH at 283nm. Two separate ICCD units were used to detect the resulting fluorescence from formaldehyde and OH. Measurement series covering the process from the start of injection until late in the expansion stroke is presented for different injection timings as well as pressure traces and emission analysis. A homogeneity index is calculated and used to compare the level of homogeneity resulting from injection timings. From early injection until about 50CAD BTDC the time, between onset of low temperature reactions and start of the high temperature reactions, is long enough for the formaldehyde to form an almost homogeneous distribution before it is being consumed. For later injection timings the high temperature reactions starts before this mixing is completed and therefore the formaldehyde distribution is not longer homogeneous and the combustion is more diesel like.
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| 12. |
- Collin, Robert, et al.
(author)
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The Effect of Fuel Volatility on Hcci Using Simultaneous Formaldehyde and Oh Plif
- 2004
-
In: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191. ; :2004-01-2948
-
Journal article (peer-reviewed)abstract
- Simultaneous formaldehyde and OH PLIF have been applied in a direct-injected HCCI engine. The engine is a 0.5 l single-cylinder optical engine equipped with EGR system. PLIF measurements were performed with the engine run with two different fuels of low and high volatility, respectively. Different ratios of EGR were also examined. The aim of the study was to investigate how fuels with different volatility and EGR affect the HCCI combustion and measurements were performed for early and late injection timings. Measurements are presented for different injection timings showing formaldehyde and OH from start of injection until late in the expansion stroke. Also, formaldehyde distributions obtained from after the low temperature regime and before the high temperature regime are studied for different tuning of the start of injection from 300 CAD to 20 CAD before top dead center. In this investigation the spatial homogeneity of the formaldehyde distributions and the surface fraction of LIF signal covering the image are compared for the different fuels and EGR ratios.
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| 13. |
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| 14. |
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| 15. |
- Giritli Nygren, Katarina, 1971-, et al.
(author)
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Replik : Vi måste stå upp när regimer tystar sina forskare
- 2018
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In: Tidningen Curie. - Stockholm : Vetenskapsrådet. - 2001-3426.
-
Journal article (pop. science, debate, etc.)abstract
- I Turkiet har tusentals akademiker tystats av regimen. För att kunna bemöta det globala hotet mot fri forskning, måste regeringens agenda för internationalisering kompletteras. Vi föreslår tre konkreta strategier för solidarisk internationalisering, skriver forskare vid Mittuniversitetet och Södertörns högskola.
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| 16. |
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| 17. |
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| 18. |
- Hasegawa, Ryo, et al.
(author)
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Influence of homogeneity on HCCI combustion
- 2005
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In: AutoTechnology. - 1616-8216. ; 5:3, s. 48-51
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Journal article (other academic/artistic)abstract
- A new laser technique for detecting the air/fuel mixture in the combustion process is presented as a method for improving cycle-by-cycle variations in an HCCI engine.
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| 19. |
- Hassan, Saadia, et al.
(author)
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Novel activity of acriflavine against colorectal cancer tumor cells
- 2011
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In: Cancer Science. - : Wiley. - 1347-9032 .- 1349-7006. ; 102:12, s. 2206-2213
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Journal article (peer-reviewed)abstract
- A high-throughput screen of the cytotoxic activity of 2000 molecules from a commercial library in three human colon cancer cell lines and two normal cell types identified the acridine acriflavin to be a colorectal cancer (CRC) active drug. Acriflavine was active in cell spheroids, indicating good drug penetration and activity against hypoxic cells. In a validation step based on primary cultures of patient tumor cells, acriflavine was found to be more active against CRC than ovarian cancer and chronic lymphocytic leukemia. This contrasted to the activity pattern of the CRC active standard drugs 5-fluorouracil, irinotecan and oxaliplatin. Mechanistic studies indicated acriflavine to be a dual topoisomerase I and II inhibitor. In conclusion, the strategy used seems promising for identification of new diagnosis-specific cancer drugs.
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| 20. |
- Hildingsson, Leif, et al.
(author)
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Optical Diagnostics of Hcci and Low-Temperature Diesel Using Simultaneous 2-D Plif of Oh and Formaldehyde
- 2004
-
In: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191. ; :2004-01-2949
-
Journal article (peer-reviewed)abstract
- Simultaneous OH- and formaldehyde planar-LIF measurements have been performed in an optical engine using two laser sources working on 283 and 355 nm, respectively. The engine used for the measurements was a car diesel engine converted to single-cylinder operation and modified for optical access. The fuel, n-heptane, was injected by a direct injection common-rail system and the engine was also fitted with an EGR system. The engine was operated in both HCCI mode and diesel mode. Due to the low load, the diesel mode resulted in low-temperature diesel combustion and because of limitations in maximum pressure and maximum rate of pressure increase of the optical engine, the diesel mode was run at a higher EGR percentage than the HCCI mode to slow down the combustion. A third mode, pilot combustion, was also investigated. This pilot combustion is created by an injection at 30 CAD before TDC followed by a second injection just before TDC. The OH and formaldehyde LIF images were compared with the heat-release calculated from the pressure traces. Analyses of the emissions, of for example NOx and HC, were also performed for the different operating modes.
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| 21. |
- Hildingsson, Leif, et al.
(author)
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Optical Diagnostics of HCCI and UNIBUS Using 2-D PLIF of OH and Formaldehyde
- 2005
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In: SAE technical paper series.
-
Journal article (peer-reviewed)abstract
- Simultaneous OH- and formaldehyde planar-LIF measurements have been performed in an optical engine using two laser sources working on 283 and 355 nm, respectively. The measurements were performed in a light- duty diesel engine, using n-heptane as fuel, converted to single- cylinder operation and modified for optical access. It was also equipped with a direct-injection, common-rail system as well as an EGR system. The engine was operated in both HCCI mode, using a single fuel injection, and UNIBUS (Uniform Bulky Combustion System) mode, using two injections of fuel with one of the injections at 50 CAD before TDC and the other one just before TDC. The OH and formaldehyde LIF images were compared with the heat- release calculated from the pressure-traces. Analyses of the emissions, for example NOx and HC, were also performed for the different operating conditions.
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| 22. |
- Hult, Johan, et al.
(author)
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Application of a high-repetition-rate laser diagnostic system for single-cycle-resolved imaging in internal combustion engines
- 2002
-
In: Applied Optics. - 2155-3165. ; 41:24, s. 5002-5014
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Journal article (peer-reviewed)abstract
- High-repetition-rate laser-induced fluorescence measurements of fuel and OH concentrations in internal combustion engines are demonstrated. Series of as many as eight fluorescence images, with a temporal resolution ranging from 10 mus to 1 ms, are acquired within one engine cycle. A multiple-laser system in combination with a multiple-CCD camera is used for cycle-resolved imaging in spark-ignition, direct-injection stratified-charge, and homogeneous-charge compression-ignition engines. The recorded data reveal unique information on cycle-to-cycle variations in fuel transport and combustion. Moreover, the imaging system in combination with a scanning mirror is used to perform instantaneous three-dimensional fuel-concentration measurements.
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| 23. |
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| 24. |
- Hult, Johan, et al.
(author)
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Quantitative three-dimensional imaging of soot volume fraction in turbulent non-premixed flames
- 2002
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In: Experiments in Fluids. - : Springer Science and Business Media LLC. - 1432-1114 .- 0723-4864. ; 33:2, s. 265-269
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Journal article (peer-reviewed)abstract
- A three-dimensional (3-D) imaging system for studies of reactive and non-reactive flows is described. It can be used to reveal the topology of turbulent structures and to extract 3-D quantities, such as concentration gradients. Measurements are performed using a high repetition rate laser and detector system in combination with a scanning mirror. In this study, the system is used for laser-induced incandescence measurements to obtain quantitative 3-D soot volume fraction distributions in both laminar and turbulent non-premixed flames. From the acquired data, iso-concentration surfaces are visualised and concentration gradients calculated.
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| 25. |
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| 26. |
- Hultqvist, Anders, et al.
(author)
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The Hcci Combustion Process in a Single Cycle-High-Speed Fuel Tracer Lif and Chemiluminescence Imaging
- 2002
-
In: SAE Technical Papers.
-
Journal article (peer-reviewed)abstract
- The Homogeneous Charge Compression Ignition (HCCI) combustion progress has been characterized by means of high- speed fuel tracer Planar Laser-Induced Fluorescence (PLIF) combined with simultaneous chemiluminescence imaging. Imaging has been conducted using a high-speed laser and detector system. The system can acquire a sequence of eight images within less than one crank angle. The engine was run at 1200 rpm on iso-octane or ethanol and a slight amount of acetone was added as a fuel tracer, providing a marker for the unburned areas. The PLIF sequences showed that, during the first stage of combustion, a well distributed decay of fuel concentration occurs. During the later parts of the combustion process the fuel concentration images present much more structure, with distinct edges between islands of unburned fuel and products. The transition between the evenly distributed fuel oxidation in the beginning and the large structures at the end, is most likely the result of a gradual amplification of small temperature inhomogeneities and an expansion of burned gas compressing the unburned.
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| 27. |
- Kaminski, Clemens, et al.
(author)
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Development of high speed spectroscopic imaging techniques for the time resolved study of spark ignition phenomena
- 2000
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In: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191.
-
Journal article (peer-reviewed)abstract
- This paper reports on the development of novel time resolved spectroscopic imaging techniques for the study of spark ignition phenomena in combustion cells and an SI-engine. The techniques are based on planar laser induced fluorescence imaging (PLIF) of OH radicals, on fuel tracer PLIF, and on chemiluminescence. The techniques could be achieved at repetition rates reaching several hundreds of kilo-Hz and were cycle resolved. These techniques offer a new path along which engine related diagnostics can be undertaken, providing a wealth of information on turbulent spark ignition.
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| 28. |
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| 29. |
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| 30. |
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| 31. |
- Nygren, Arne, 1971, et al.
(author)
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Cryptic species of Notophyllum (Polychaeta: Phyllodocidae) in Scandinavian waters
- 2010
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In: Organisms Diversity & Evolution. - : Springer Science and Business Media LLC. - 1439-6092 .- 1618-1077. ; 10:3, s. 193-204
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Journal article (peer-reviewed)abstract
- The phyllodocid polychaete Notophyllum foliosum occurs in two colour morphs in Swedish and Norwegian waters, one palish yellow to grey form with black patches that is restricted to deeper waters and often associated with reefs of the deep-water coral Lophelia pertusa, and one usually yellow-orange form with black patches and white spots that is usually encountered on more shallow bottoms. We have sampled the two forms from sympatric occurrences in Norway, and the shallow form from the Swedish west coast. Phylogenetic and haplotype analyses based on the mitochondrial cytochrome c oxidase subunit I (COI) gene and the nuclear internal transcribed spacer region (ITS1-5.8SrDNA-ITS2) unequivocally indicate that the two forms represent different species. We apply the name N. foliosum (Sars, 1835) to the 'shallow form', and propose N. crypticum n. sp. for the 'deep form'. A lectotype is fixed for N. foliosum.
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| 32. |
- Nygren, Erik, et al.
(author)
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Potential sources of contamination on textiles and hard surfaces identified as high-touch sites near the patient environment
- 2023
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In: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 18
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Journal article (peer-reviewed)abstract
- The hospital environment represents an important mediator for the transmission of healthcare-associated infections through direct and indirect hand contact with hard surfaces and textiles. In this study, bacteria on high-touch sites, including textiles and hard surfaces in two care wards in Sweden, were identified using microbiological culture methods and 16S rDNA sequencing. During a cross-sectional study, 176 high-touch hard surfaces and textiles were identified and further analysed using microbiological culture for quantification of total aerobic bacteria, Staphylococcus aureus, Clostridium difficile and Enterobacteriacae. The bacterial population structures were further analysed in 26 samples using 16S rDNA sequencing. The study showed a higher frequency of unique direct hand-textile contacts (36 per hour), compared to hard surfaces (2.2 per hour). Hard surfaces met the recommended standard of ≤ 5 CFU/cm2 for aerobic bacteria and ≤ 1 CFU/cm2 for S. aureus (53% and 35%, respectively) to a higher extent compared to textiles (19% and 30%, respectively) (P = 0.0488). The number of bacterial genera was higher on textiles than on the hard surfaces. Staphylococcus (30.4%) and Corynebacterium (10.9%) were the most representative genera for textiles and Streptococcus (13.3%) for hard surfaces. The fact that a big percentage of the textiles did not fulfil the criteria for cleanliness, combined with the higher bacterial diversity, compared to hard surfaces, are indicators that textiles were bacterial reservoirs and potential risk vectors for bacterial transmission. However, since most of the bacteria found in the study belonged to the normal flora, it was not possible to draw conclusions of textiles and hard surfaces as sources of healthcare associated infections. 2023 Nygren et al.
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| 33. |
- Nygren, Jenny
(author)
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Development of Multi-Dimensional Laser Techniques for In-situ Combustion Diagnostics
- 2003
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Doctoral thesis (other academic/artistic)abstract
- Multi-dimensional, laser-based measurements of quantities important for obtaining a better understanding of combustion processes, particularly of temperature and of species distributions, were performed using laser-induced fluorescence (LIF). The main purpose of the temperature experiments was to investigate the potential of employing a two-line atomic fluorescence technique (TLAF), using indium as the tracer species, in sooting environments such as in diesel engines. The initial studies were performed in a laboratory flame in which the amount of soot was varied for investigating whether the technique suffers from strong background radiation due to heated soot particles, absorption of laser wavelengths or interference caused by poly-aromatic hydrocarbons (PAH). The results indicate In-TLAF thermometry to perform well over a large range of -values. Indium is an attractive tracer candidate since both its excitation and detection wavelengths are in the visible range (410 nm and 451 nm), where absorption by hydrocarbons and other native combustion species was found to be negligible. Because of the oscillator strength of indium being high, the laser energy required is very low. This is an advantage since lasers of high power give rise either to laser-induced incandescence (LII) from soot particles or to strong LIF from PAH. The broad temperature sensitivity range, some 700–3000 K, of the technique when indium atoms are employed allows measurements to be performed in most practical combustion environments. In fuel-rich flames the seeding efficiency also increases, since the loss of active species due to oxidation there plays only a subordinate role. This is an advantage, since it permits sufficient signal-to-noise ratios to be achieved with use of a lower seeding concentration minimising the effects of the seeded species on the combustion chemistry. This makes In-TLAF highly attractive for thermometry applications in fuel-rich and turbulent combustion processes. In-TLAF may well prove to be a good candidate for future measurements in diesel engines, where temperature information is of crucial importance for further development of engine design. Engine measurements were performed using a high-speed laser and camera system. The laser cluster and the framing camera employed are able to capture eight images within 50 , making studies of time and spatially resolved combustion events possible. Concentration measurements were performed in engines of three types; a spark-ignition (SI) engine, a gasoline-direct-injection (GDI) engine and a homogeneous-charge- compression-ignition (HCCI) engine. The high-speed system was used so as to be able to perform true single-cycle-resolved measurements in the engines, all the data being recorded in a single engine cycle without any averaging effects caused by cycle-to-cycle variations. Studies of the sort are impossible to perform using a system that captures only single-shot images from subsequent cycles. The detection of single-cycle-resolved images of fuel and OH distributions was performed initially in a lab-top SI-engine with the aim of investigating the applicability of the technique. The same technique was then applied to a GDI engine at the Volvo Car Corporation. In that engine, fuel transport from the start of injection to the time of ignition was studied, along with flame propagation using both OH and fuel-tracer PLIF. The onset and development of combustion was also studied in the HCCI engine located at the Division of Combustion Engines in Lund, using fuel-tracer PLIF. The main goal there being to capture the appearance and growth of auto-ignition kernels for investigating whether any flame propagation occurs in a combustion process of this type. Cycle-to-cycle variations were also studied by comparing different cycles. To investigate whether a fuel island in a two-dimensional image is isolated or simply looks like an island due to wrinkling effects in and out the laser sheet, an experiment was performed in which 3D data was recorded. The topology of the fuel distribution can also be studied by obtaining measurements in three dimensions. From such experimental data, spatial gradients in all three directions can be calculated, providing information of interesting to modellers.
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| 34. |
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| 35. |
- Nygren, Jenny, et al.
(author)
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Three-dimensional laser induced fluorescence of fuel distributions in an HCCI engine
- 2002
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In: Proceedings of the Combustion Institute. - 0082-0784 .- 1878-027X. ; 29, s. 679-685
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Conference paper (peer-reviewed)abstract
- Three-dimensional imaging of fuel tracer planar laser-induced fluorescence in a homogeneous charge compression ignition (HCCI) engine is presented. A high-speed multiple Nd:YAG laser and detection system, in combination, with a scanning mirror, are used to collect eight images, with an equidistant separation of 0.5 mm. Three-dimensional isoconcentration surfaces calculated from the data are visualized. Three-dimensional imaging offers new opportunities to study different combustion events, specifically the topology of flame structures. For example, it is possible to distinguish if separate islands in a fluorescence image really are separate or if it is an effect from wrinkling in and out of the laser sheet. The PLIF images were also analyzed by identifying five intensity ranges corresponding to increasing degrees of reaction progress. The gradual fuel consumption and thus combustion was then analyzed by calculating the volumetric fraction of these intensity ranges for different crank angle positions. The occurrence of multiple isolated ignition spots and the observed gradual decrease in fuel concentration indicates that HCCI combustion relies on distributed reactions and not flame propagation.
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| 36. |
- Nygren, Thomas, 1972-, et al.
(author)
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Hur motiverar gymnasieelever sina bedömningar av trovärdiga och vilseledande digitala nyheter?
- 2020
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In: Nordidactica. - Karlstad : CSD Karlstad. - 2000-9879. ; :2, s. 153-178
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Journal article (peer-reviewed)abstract
- In this study, we investigate how ca. 400 students, age 16-19, determine the trustworthiness of false, biased and credible news. We examine their justifications of their assessments of the credibility with regard to the source (who?), the content (what?), the design (how?) and the underlying purposes (why?). We find that students’ patterns of justifications can be linked to different assessments. For example, students finding junk news credible may have special problems separating different kinds of sources. Students who fail to debunk a manipulated image often rely on what they see in the image in contrast to students who determine credibility upon what is not in the image. We also find that test-items used in previous research can be linked to aspects of civic online reasoning not identified in previous research. We identify complex potentials and pitfalls among students important for education and further research.
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| 37. |
- Nygren, Thomas, 1972-, et al.
(author)
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Students Assessing Digital News and Misinformation
- 2020
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In: Disinformation in Open Online Media. - Cham : Springer International Publishing. - 9783030618407 - 9783030618414 ; , s. 63-79
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Conference paper (peer-reviewed)abstract
- Previous research has highlighted how young people struggle to distinguishnews from misinformation. In this study, we investigate how ca. 400 students determine the trustworthiness of false, biased and credible news.We find that students use different strategies depending on what they evaluate. For example, students who fail to debunk a manipulated image often rely on what they see in the image in contrast to students who determine credibility upon what is not in the image. Students finding junk news credible may have special problems separating different kinds of sources. We identify potentials and pitfalls among students important for further investigation, research and a focus on in education.
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| 38. |
- Richter, Mattias, et al.
(author)
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Studies of the combustion process with simultaneous formaldehyde and OHPLIF in a direct-injected HCCI engine
- 2005
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In: JSME International Journal. Series B: Fluids and Thermal Engineering. - : Japan Society of Mechanical Engineers. - 1340-8054. ; 48:4, s. 701-707
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Journal article (peer-reviewed)abstract
- This paper presents simultaneous laser based measurements of formaldehyde and OH-radical distributions in a 0.5 liter optical HCCI engine with direct injection. Formaldehyde is formed as an intermediate species when combusting hydrocarbons. The formation occurs through low temperature reactions in an early phase of the combustion process. Later in the process formaldehyde is being consumed. Formaldehyde is, therefore, used as indicator of the first stage of combustion and a marker of zones with low-lemperature reactions. The OH radical is formed as an intermediate during the high temperature reactions, and is used as a marker of zones where the combustion is ongoing. The purpose of the investigation was to study how the combustion process is affected by the change in homogeneity that arises from early and late injection, respectively. The measurement technique used was planar laser-induced fluorescence where formaldehyde was excited at 355 nm and OH at 283 nm.
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| 39. |
- Senkowski, Wojciech, et al.
(author)
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Large-Scale Gene Expression Profiling Platform for Identification of Context-Dependent Drug Responses in Multicellular Tumor Spheroids
- 2016
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In: CELL CHEMICAL BIOLOGY. - : Elsevier BV. - 2451-9448 .- 2451-9456. ; 23:11, s. 1428-1438
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Journal article (peer-reviewed)abstract
- Cancer cell lines grown as two-dimensional (2D) cultures have been an essential model for studying cancer biology and anticancer drug discovery. However, 2D cancer cell cultures have major limitations, as they do not closely mimic the heterogeneity and tissue context of in vivo tumors. Developing three-dimensional (3D) cell cultures, such as multicellular tumor spheroids, has the potential to address some of these limitations. Here, we combined a high-throughput gene expression profiling method with a tumor spheroid-based drug-screening assay to identify context-dependent treatment responses. As a proof of concept, we examined drug responses of quiescent cancer cells to oxidative phosphorylation (OXPHOS) inhibitors. Use of multicellular tumor spheroids led to discovery that the mevalonate pathway is upregulated in quiescent cells during OXPHOS inhibition, and that OXPHOS inhibitors and mevalonate pathway inhibitors were synergistically toxic to quiescent spheroids. This work illustrates how 3D cellular models yield functional and mechanistic insights not accessible via 2D cultures.
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| 40. |
- Tunér, Martin, et al.
(author)
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Formaldehyde and Hydroxyl Radicals in an HCCI Engine - Calculations and LIF-Measurements
- 2007
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In: SAE technical paper series.
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Journal article (peer-reviewed)abstract
- Concentrations of hydroxyl radicals and formaldehyde were calculated using homogeneous (HRM) and stochastic reactor models (SRM), and the result was compared to LIF measurements from an optically accessed iso-octane/n-heptane-fuelled homogeneous charge compression ignition (HCCI) engine. The comparison was at first conducted from averaged total concentrations/signal strengths over the entire combustion volume, which showed a good qualitative agreement between experiments and calculations. Time- and the calculation-inlet-temperature-resolved concentrations of formaldehyde and hydroxyl radicals obtained through HRM are presented. Probability density plots (PDPs) through SRM calculations and LIF measurements are presented and compared, showing a very good agreement considering their delicate and sensitive nature. Thus it is concluded that SRM is a valid model for these purposes, justifying the use of SRM in order to extend the evaluated concentration ranges of the analyzed species beyond the detection/separation level. It is shown that formaldehyde concentration increases slowly, contrary to hydroxyl which is fast developed. Formaldehyde is locally fast consumed once high temperature chemistry has started, and the highest maximum concentrations of formaldehyde are found in cases where low-temperature chemistry was never transitioned to high-temperature ignition. The PDP's from SRM calculations give increased insight of the occurrence and development of autoignition. During the onset of ignition, the regions with the highest formaldehyde concentrations also have the highest concentrations of hydroxyl radicals. The low-temperature heat release (LTHR) maximum occurs before maximum of formaldehyde, and the regions of (for the LTHR regime relatively) high hydroxyl concentrations gradually becomes fewer until they cease to exist; this occurs after the LTHR peak but before formaldehyde maximum. During the transition state all regions have similar formaldehyde concentrations but varying concentrations of hydroxyl.
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| 41. |
- Wiik, Jenny, 1975, et al.
(author)
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Den journalistiska professionen i nätverkssamhället
- 2016
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In: SOU 2016:30 Människorna, Medierna, Marknaden. Medieutredningens forskningsantologi om en demokrati i förändring. - : Wolters Kluwer. - 9789138244333 ; , s. 261-282
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Book chapter (other academic/artistic)
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| 42. |
- Wiik, Jenny, et al.
(author)
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Den journalistiska professionen i nätverkssamhället
- 2016
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In: Människorna, medierna och makrnaden. - Stockholm : Wolters Kluwer. - 9789138244333 ; , s. 262-282
-
Book chapter (other academic/artistic)abstract
- I medieutvecklingen är den journalistiska professionen central. Större delen av det medieutbud som möter oss varje dag är producerat av journalister. Men den journalistiska professionen är i gungning och utsatt för stora utmaningar: Färre journalister på redaktionerna ska producera mer innehåll för fler kanaler och plattformar. Det ska gå snabbare, samtidigt som kraven på att hantera alla olika uttrycksformer växer. Samtidigt får yrket konkurrens av alltifrån ideella gräsrotsjournalister och bloggare till växande kader av PR-konsulter och informatörer. Medieföretagen – särskilt dagspressen – kämpar med bristande finansiering (se en fördjupning i kapitlet av Ohlsson i denna bok), vilket har lett till kraftiga minskningar av personal; under tio års tid har antalet journalister på dagstidningar minskat med cirka 25 procent (Nygren och Althén, 2014). Jakten på nya inkomster ställer också journalisterna inför frågor om yrkets gränser när nya former av textreklam och ”uppdragsjournalistik” växer. Detta kapitel syftar till att i korthet summera den utveckling som journalistyrket genomgått och de möjligheter och hinder som möter journalistiken i dag. En särskilt viktig fråga är vem som är journalist i dagens nätverkssamhälle – i ett samhälle där ”medieborgarna” blir alltmer aktiva ställs nya krav på journalister att definiera sin roll. Detta är inte bara frågor som berör journalister – det handlar också om journalistikens demokratiska funktioner.
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| 43. |
- Worsaae, K., et al.
(author)
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Phylogenetic position of Nerillidae and Aberranta (Polychaeta, Annelida), analysed by direct optimization of combined molecular and morphological data
- 2005
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In: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 34:3, s. 313-328
-
Journal article (peer-reviewed)abstract
- The phylogenetic position of the most speciose meiofaunal polychaete family, Nerillidae, has remained contentious. Recent hypotheses have generally focused on the fact that Nerillidae shares with Aciculata (a major polychaete subgroup) features such as compound chaetae, ventral buccal organ and short ventrolateral palps. Here we present the first phylogenetic analysis of Aciculata, together with Nerillidae, combining morphological and molecular data. We also include Aberrantidae, previously referred to or placed near to spiomorph polychaetes, but recently referred to Aciculata, possibly close to Nerillidae. The data sets of 24 terminals contain 53 morphological characters and nearly complete sequences of 18S rRNA. The sequences were analysed simultaneously with the morphological data by direct optimization in the program POY with a variety of parameter settings (costs of gaps: transversions: transitions). The various settings resulted in markedly different phylogenetic hypotheses, but on the basis of congruence (ILD) the results of two parameter settings were chosen. In all analyses, the three included nerillid species constituted a monophyletic group. Only two analyses provided fully resolved cladograms. The morphological analysis gave poor resolution and the position of the nerillids was equivocal. The two molecular-based cladograms (minimizing ILD) were also poorly resolved, but one provided a position for nerillids next to Eunice pennata and Nothria conchilega, from the subgroup Eunicida within Aciculata. The two cladograms of the combined analyses (minimizing ILD) were fully resolved and placed nerillids in a terminal position next to Aberranta sp., within a clade of eunicidan species. The study showed that the analytical conditions for the homology assignment of 18S rRNA strongly influenced the phylogenetic results. The various previous proposals on the phylogenetic position of the Nerillidae are reviewed, some of which are in accordance with the results of the present study.
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