1. |
- Annacker, O, et al.
(författare)
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Essential role for CD103 in the T cell-mediated regulation of experimental colitis
- 2005
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Ingår i: Journal of Experimental Medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 202:8, s. 1051-1061
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Tidskriftsartikel (refereegranskat)abstract
- The integrin CD103 is highly expressed at mucosal sites, but its role in mucosal immune regulation remains poorly understood. We have analyzed the functional role of CD103 in intestinal immune regulation using the T cell transfer model of colitis. Our results show no mandatory role for CD103 expression on T cells for either the development or CD4(+)CD25(+) regulatory T (T reg) cell-mediated control of colitis. However, wild-type CD4(+)CD25(+) T cells were unable to prevent colitis in immune-deficient recipients lacking CD103, demonstrating a nonredundant functional role for CD103 on host cells in T reg cell-mediated intestinal immune regulation. Non-T cell expression of CD103 is restricted primarily to CD11c(high) MHC class IIhigh dendritic cells (DCs). This DC population is present at a high frequency in the gut-associated lymphoid tissue and appears to mediate a distinct functional role. Thus, CD103(+) DCs, but not their CD103(-) counterparts, promoted expression of the gut-homing receptor CCR9 on T cells. Conversely, CD103(-) DCs promoted the differentiation of IFN-gamma-producing T cells. Collectively, these data suggest that CD103(+) and CD103(+) DCs represent functionally distinct subsets and that CD103 expression on DCs influences the balance between effector and regulatory T cell activity in the intestine.
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2. |
- Ask, Anders, et al.
(författare)
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The potential of proton beam radiation therapy in gastrointestinal cancer
- 2005
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 44:8, s. 896-903
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Tidskriftsartikel (refereegranskat)abstract
- A group of Swedish oncologists and hospital physicists have estimated the number of patients in Sweden suitable for proton beam therapy. The estimations have been based on current statistics of tumour incidence, number of patients potentially eligible for radiation treatment, scientific support from clinical trials and model dose planning studies and knowledge of the dose-response relations of different tumours and normal tissues. In gastrointestinal cancers, it is assessed that at least 345 patients, mainly non-resectable rectal cancers, oesophageal and liver cancers, are eligible. Great uncertainties do however exist both in the number of patients with gastrointestinal cancers suitable for radiation therapy, and in the proportion of those where proton beams may give sufficiently better results.
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3. |
- Hasegawa, Ryo, et al.
(författare)
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Influence of homogeneity on HCCI combustion
- 2005
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Ingår i: AutoTechnology. - 1616-8216. ; 5:3, s. 48-51
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)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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4. |
- Hildingsson, Leif, et al.
(författare)
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Optical Diagnostics of HCCI and UNIBUS Using 2-D PLIF of OH and Formaldehyde
- 2005
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Ingår i: SAE technical paper series.
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Tidskriftsartikel (refereegranskat)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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5. |
- Johansson, Bengt, et al.
(författare)
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The potential of proton beam radiation therapy in prostate cancer, other urological cancers and gynaecological cancers
- 2005
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 44:8, s. 890-5
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Tidskriftsartikel (refereegranskat)abstract
- A group of Swedish oncologists and hospital physicists have estimated the number of patients in Sweden suitable for proton beam therapy. The estimations have been based on current statistics of tumour incidence, number of patients potentially eligible for radiation treatment, scientific support from clinical trials and model dose planning studies and knowledge of the dose-response relations of different tumours and normal tissues. In prostate cancer it is estimated that annually about 300 patients and in gynaecological cancer about 50 patients, are candidates for proton beam therapy. Owing to major uncertainties, it has not been possible to give an estimate of the number of potential patients with urinary bladder cancer.
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6. |
- Johansson Lindbom, Bengt, et al.
(författare)
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Functional specialization of gut CD103+ dendritic cells in the regulation of tissue-selective T cell homing.
- 2005
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Ingår i: Journal of Experimental Medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 202:8, s. 1063-1073
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Tidskriftsartikel (refereegranskat)abstract
- Gut-associated lymphoid tissue (GALT) dendritic cells (DCs) display a unique ability to generate CCR9+α4β7+ gut-tropic CD8+ effector T cells. We demonstrate efficient induction of CCR9 and α4β7 on CD8+ T cells in mesenteric lymph nodes (MLNs) after oral but not intraperitoneal (i.p.) antigen administration indicating differential targeting of DCs via the oral route. In vitro, lamina propria (LP)–derived DCs were more potent than MLN or Peyer's patch DCs in their ability to generate CCR9+α4β7+ CD8+ T cells. The integrin α chain CD103 (αE) was expressed on almost all LP DCs, a subset of MLN DCs, but on few splenic DCs. CD103+ MLN DCs were reduced in number in CCR7−/− mice and, although CD8+ T cells proliferated in the MLNs of CCR7−/− mice after i.p. but not oral antigen administration, they failed to express CCR9 and had reduced levels of α4β7. Strikingly, although CD103+ and CD103− MLN DCs were equally potent at inducing CD8+ T cell proliferation and IFN-γ production, only CD103+ DCs were capable of generating gut-tropic CD8+ effector T cells in vitro. Collectively, these results demonstrate a unique function for LP-derived CD103+ MLN DCs in the generation of gut-tropic effector T cells.
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7. |
- Lemel, Mikael, et al.
(författare)
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Quantification of the Formaldehyde Emissions from Different HCCI Engines Running on a Range of Fuels
- 2005
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Ingår i: SAE Transactions, Journal of Fuels and Lubricants. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0096-736X. ; 114:4, s. 1347-1357
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, the formaldehyde emissions from three different types of homogenous charge compression ignition (HCCI) engines are quantified for a range of fuels by means of Fourier Transform Infra Red (FTIR) spectroscopic analysis. The engines types are differentiated in the way the charge is prepared. The characterized engines are; the conventional port fuel injected one, a type that traps residuals by means of a Negative Valve Overlap (NVO) and finally a Direct Injected (DI) one. Fuels ranging from pure n-heptane to iso-octane via diesel, gasoline, PRF80, methanol and ethanol were characterized. Generally, the amount of formaldehyde found in the exhaust was decreasing with decreasing air/fuel ratio, advanced timing and increasing cycle temperature. It was found that increasing the source of formaldehyde i.e. the ratio of heat released in the cool-flame, brought on higher exhaust contents of formaldehyde. The application of a standard three-way catalyst completely removed formaldehyde from the exhaust stream.
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8. |
- Richter, Mattias, et al.
(författare)
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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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Ingår i: 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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Tidskriftsartikel (refereegranskat)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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9. |
- Särner, Gustaf, et al.
(författare)
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Cycle Resolved Wall Temperature Measurements Using Laser-Induced Phosphorescence in an HCCI Engine
- 2005
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Ingår i: SAE technical paper series.
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Tidskriftsartikel (refereegranskat)abstract
- Cycle-resolved wall temperature measurements have been performed in a one-cylinder, port-injected optical Scania D12 truck engine run in HCCI mode. Point measurements at various locations were made using Laser-Induced Phosphorescence (LIP). Single point measurements with thermographic phosphors utilize the temperature dependency of the phosphorescence decay time. The phosphorescence peak at 538 nm from the thermographic phosphor La2O2S:Eu was used to determine temperature. A frequency tripled 10 Hz pulsed Nd:YAG laser delivering ultraviolet (UV) radiation at 355 nm was used for excitation of the phosphor. Detection in the spectral region 535 - 545 nm was performed every cycle with a photo multiplier tube connected to a 3 GHz oscilloscope. Measurements were made at four points on the cylinder head surface and two points on the outlet and inlet valves respectively. For each location measurements were made at different loads and at different crank angle degrees (CAD). The aim of the presented work was to study the feasibility of using LIP for single-shot, cycle-resolved wall temperature measurements.
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10. |
- Särner, Gustaf, et al.
(författare)
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Simultaneous PLIF Measurements for Visualization of Formaldehyde- and Fuel- Distributions in a DI HCCI Engine
- 2005
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Ingår i: SAE technical paper series. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International.
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Tidskriftsartikel (refereegranskat)abstract
- Simultaneous laser-induced fluorescence (LIF) imaging of formaldehyde and a fuel-tracer have been performed in a direct-injection HCCI engine. A mix of N-heptane and iso-octane was used as fuel and Toluene as fluorescent tracer. The experimental setup involves two pulsed Nd:YAG lasers and two ICCD cameras. Frequency-quadrupled laser radiation at 266 nm from one of the Nd:YAG lasers was used for excitation of the fuel tracer. The resulting fluorescence was detected with one of the ICCD cameras in the spectral region 270-320 nm. The second laser system provided frequency-tripled radiation at 355 nm for excitation of formaldehyde. Detection in the range 395-500 nm was achieved with the second ICCD. The aim of the presented work is to investigate the applicability of utilizing formaldehyde as a naturally occurring fuel marker. Formaldehyde is formed in the low-temperature reactions (LTR) prior to the main combustion and should thus be present were fuel is located until it is consumed. Measurements were performed when injecting fuel early and late in the compression stroke. Early injection timing results in a homogeneous charge at the time of auto-ignition, while late timing gives a more stratified charge. The crank angle position at which measurements were performed was altered to cover the entire combustion cycle. The measurement images show instantaneous distributions of toluene and formaldehyde respectively. Images from both early and late injection and at all crank angle degrees show good spatial resemblance between toluene signal area and formaldehyde signal area. The work presented in this paper shows that formaldehyde is a feasible alternative to traditional fuel tracers for visualizing fuels featuring low-temperature reactions in HCCI combustion
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