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61.
Long H Shi T Borm PJ Määttä J Husgafvel-Pursiainen K Savolainen K Krombach F 《Particle and fibre toxicology》2004,1(1):3
BACKGROUND: Respiratory symptoms, impaired lung function, and asthma have been reported in workers exposed to wood dust in a number of epidemiological studies. The underlying pathomechanisms, however, are not well understood. Here, we studied the effects of dust from pine (PD) and heat-treated pine (HPD) on the release of reactive oxygen species (ROS) and inflammatory mediators in rat alveolar macrophages. METHODS: Tumour necrosis factor-alpha (TNF-alpha) and macrophage inflammatory protein-2 (MIP-2) protein release, TNF-alpha and MIP-2 mRNA expression, and generation of ROS were studied as end points after treatment of rat alveolar macrophages with PD or HPD. In a separate series of experiments, the antioxidants glutathione and N-acetyl-L-cysteine were included in combination with wood dust. To determine the endogenous oxidative and antioxidant capacity of wood dusts, electron spin resonance (ESR) spectroscopy was used. RESULTS: After 4 h incubation, both PD and HPD elicited a significantly (p < 0.05) increased mRNA expression of TNF-alpha and MIP-2 as well as a concentration-dependent release of TNF-alpha and MIP-2 protein. Interestingly, PD induced a significantly higher TNF-alpha and MIP-2 production than HPD. Moreover, a significantly increased ROS production was observed in alveolar macrophages exposed to both PD and HPD. In the presence of the antioxidants glutathione and N-acetyl-L-cysteine, the PD- and HPD-induced release of ROS, TNF-alpha, and MIP-2 was significantly reduced. Finally, electron spin resonance analyses demonstrated a higher endogenous antioxidant capacity of HPD compared to PD. Endotoxin was not present in either dust sample. CONCLUSION: These results indicate that pine dust is able to induce expression of TNF-alpha and MIP-2 in rat alveolar macrophages by a mechanism that is, at least in part, mediated by ROS. 相似文献
62.
Auterinen I Serén T Uusi-Simola J Kosunen A Savolainen S 《Radiation protection dosimetry》2004,110(1-4):587-593
Methods for dosimetry of epithermal neutron beams used in boron neutron capture therapy (BNCT) have been developed and utilised within the Finnish BNCT project as well as within a European project for a code of practise for the dosimetry of BNCT. One outcome has been a travelling toolkit for BNCT dosimetry. It consists of activation detectors and ionisation chambers. The free-beam neutron spectrum is measured with a set of activation foils of different isotopes irradiated both in a Cd-capsule and without it. Neutron flux (thermal and epithermal) distribution in phantoms is measured using activation of Mn and Au foils, and Cu wire. Ionisation chamber (IC) measurements are performed both in-free-beam and in-phantom for determination of the neutron and gamma dose components. This toolkit has also been used at other BNCT facilities in Europe, the USA, Argentina and Japan. 相似文献
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64.
1. A new specific protein kinase C (PKC) inhibitor, Ro 31-7549, was used to explore the mechanisms by which particulate stimuli, quartz and chrysotile, stimulate human polymorphonuclear leukocytes (PMNL) to produce reactive oxygen metabolites (ROM). Also soluble stimuli, formyl-Methionyl-Leucyl-Phenylalanine (fMLP) and phorbol myristate acetate (PMA) were used. 2. Ro 31-7549 inhibited chrysotile-induced free intracellular calcium ([Ca2+]i) elevations but did not have an effect on quartz-induced elevations of [Ca2+]i. Both quartz and chrysotile induced production of ROM were partially inhibited by Ro 31-7549. fMLP-induced elevation of [Ca2+]i was inhibited by Ro 31-7549 whereas PMA did not affect [Ca2+]i. Ro 31-7549 strongly inhibited fMLP-induced ROM production, and completely abolished that induced by PMA. 3. These result suggest that PKC may have an important role in the activation of PMNL to produce ROM by particulate and soluble stimuli. However, the inhibition of chrysotile-, but not of quartz-induced [Ca2+]i elevations by Ro 31-7549 provides evidence that both PKC-dependent and -independent mechanisms may play a role in the activation of human leukocytes to produce ROM. 相似文献
65.
Mari C. W. Myhrstad Vanessa D. de Mello Ingrid Dahlman Marjukka Kolehmainen Jussi Paananen Amanda Rundblad Carsten Carlberg Ole Kristoffer Olstad Jussi Pihlajamki Kirsten B. Holven Kjeld Hermansen Lars O. Dragsted Ingibjrg Gunnarsdottir Lieselotte Cloetens Matilda Ulmius Storm Bjrn kesson Fredrik Rosqvist Janne Hukkanen Karl‐Heinz Herzig Ulf Risrus Inga Thorsdottir Kaisa S. Poutanen Markku J Savolainen Ursula Schwab Peter Arner Matti Uusitupa Stine M. Ulven 《Molecular nutrition & food research》2019,63(13)
66.
In this paper, we consider software development project success and failure from the supplier's perspective. First we clarified concepts in order to be able to exclude review articles on in-house projects, continuous services, the customer's perspective, and software product development, with the aim of providing valid results for supplier firms. We divided success criteria into project success and project management (PM) success, and, in seven articles, identified three success criteria from the supplier's perspective: customer satisfaction, short-term business benefits, and long-term business benefits. In contrast, no definition of software development project failure was found. Articles were found in seven different journals, showing that knowledge on software development project success from the supplier's perspective is fragmented. This impedes the growth of knowledge on this topic. 相似文献
67.
J. J. Toppari J. M. Kivioja J. P. Pekola M. T. Savolainen 《Journal of Low Temperature Physics》2004,136(1-2):57-91
We have experimentally studied the behaviour of the so-called Cooper pair pump (CPP) with three Josephson junctions, in the limit of small Josephson coupling E J < E C . These experiments show that the CPP can be operated as a traditional turnstile device yielding a gate-induced current 2ef in the direction of the bias voltage, by applying an RF signal with frequency f to the two gates in phase, while residing at the degeneracy node of the gate plane. Accuracy of the CPP during this kind of operation was about 3% and the fundamental Landau-Zener (LZ) limit was observed to lie above 20 MHz. We have also measured the current pumped through the array by rotating around the degeneracy node in the gate plane. We show that this reproduces the turnstile-kind of behavior. To overcome the contradiction between the obtained e-periodic DC modulation and a pure 2e-behaviour in the RF measurements, we base our observations on a general principle that the system always minimises its energy. It suggests that if the excess quasiparticles in the system have a freedom to tunnel, they will organize themselves to the configuration yielding the highest current. 相似文献
68.
69.
RP Joensuu RE Sepponen AE Lamminen SE Savolainen CG Standertskj?ld-Nordenstam 《Canadian Metallurgical Quarterly》1998,40(6):914-921
A new technique for visualization of interventional devices in magnetic resonance imaging is presented. Determination of the position of an invasive device is made possible by incorporating into the device a small marker that emits the NMR signal. This signal is enhanced by the use of the Overhauser phenomenon. This technique differs from the earlier reported techniques for marking interventional instruments in the sense that the contrast between the marker and tissue is not based on different relaxation rates, but on NMR signal enhancement. A prototype marker was constructed and inserted into an inductively fed loop-gap resonator that couples saturation energy with the marker. Circuit analogies are presented that model the Overhauser phenomenon and the coupling circuit. In vitro experiments demonstrated that the marker is visible in MR images up to a slice thickness of 50 mm when inserted in excised animal liver and fat tissues. 相似文献
70.
BACKGROUND: Environmental variation, such as an increase of mean temperature due to the greenhouse effect, as well as the genetic factors may affect the allergenicity of pollen and thus, the prevalence of allergies. The connection between these factors and the allergen content of pollen is poorly understood. OBJECTIVES: To evaluate the role of environmental and genetic factors on the allergenicity of birch pollen. METHODS: Mountain birch (Betula pubescens ssp. czerepanovii (Orl.) H?met-Ahti) pollen was studied using SDS-PAGE and IgE-immunoblotting. Pollen samples were collected from the trees of 10 half-sib families. The study trees from each family were reared in two tree line gardens where the daily mean temperatures were different during the growing season. RESULTS: The quantitative analysis of band intensities suggested that the responses of the major birch pollen allergen, Bet v 1, were stronger in the samples collected from the garden with higher daily mean temperature. Half-sib families and individual trees differed in their Bet v 1 content. CONCLUSIONS: Our results show that both genetic and environmental factors have an effect on the amount of Bet v 1. This suggests that breeding for trees low in allergen content may be possible. 相似文献