379 research outputs found
Role of Kupffer cells in liver injury induced by CpG oligodeoxynucleotide and flucloxacillin in mice
CpG oligodeoxynucleotide (CpG-ODN) is a Toll-like receptor 9 (TLR9) agonist that can induce innate immune responses. In a previous study, flucloxacillin (FLUX; 100 mg/kg, gavage)-induced liver injury in mice was enhanced by co-administration of CpG-ODN (40 μg/mouse, intraperitoneally). In this study, the mechanism of CpG-ODN sensitization to FLUX-induced liver injury was further investigated in mice inhibited of Kupffer cells (KCs) function by gadolinium chloride (GdCl3; 10 mg/kg, intravenously). GdCl3-treated mice administrated with CpG-ODN and FLUX showed lower liver injury than wild-type (WT) mice treated with CpG-ODN and FLUX. Upregulation of Fas and FasL by CpG-ODN was also inhibited in GdCl3-treated mice and mitochondrial swelling in response to FLUX failed to occur regardless of pre-treatment with CpG-ODN. When FasL-mutant gld/gld mice were treated with CpG-ODN, mitochondrial swelling in response to FLUX was also inhibited. These results suggest that KCs play an essential role in liver injury induced by CpG-ODN and FLUX. CpG-ODN may activate KCs, resulting in induction of Fas/FasL-mediated apoptosis of hepatocytes. The Fas/FasL pathway may also be an upstream regulator of CpG-ODN- and FLUX-induced changes in mitochondrial permeability transition. These results enhance our understanding of the mechanism of the adjuvant effect of CpG-ODN in this mouse model of liver injury
Effectiveness of an image generation method that expresses the visual impression of space for two-point perspective landscapes
Photographs and CG images are generally rendered using a perspective projection. However, because a perspective projection image does not always represent the visual impression of a real space, we occasionally feel a sense of incompatibility when viewing such images. We believe that clarifying the human visual characteristics will enable the creation of more realistic images. A previous study investigated the human perception of size in a real space and proposed a magnification-rate function that shows the relationship between the subjective visual size of an object to be drawn and the observation distance. Images applying the magnification-rate function provide an impression closer to that in a real space than do perspective projection images. However, these results have only been verified for single-point landscapes. In this study, to investigate the impression of an image, we applied the magnification-rate function to images portraying landscapes with a two-point perspective. The results show that the magnification-transformed images were evaluated as being closer to the impressions in a real space than those of perspective projected images. This is similar to the evaluation of transformed images for one-point perspective landscapes, suggesting that an image transformation using the magnification-rate function is effective for two-point perspective landscapes
Testing Higgs portal dark matter via fusion at a linear collider
We investigate the possibility of detecting dark matter at TeV scale linear
colliders in the scenario where the dark matter is a massive particle weakly
interacting only with the Higgs boson in the low energy effective theory
(the Higgs portal dark matter scenario). The dark matter in this scenario would
be difficult to be tested at the CERN Large Hadron Collider when the decay of
the Higgs boson into a dark matter pair is not kinematically allowed. We study
whether even in such a case the dark matter can be explored or not via the
boson fusion process at the International Linear Collider and also at a
multi TeV lepton collider. It is found that for the collision energy
TeV with the integrated luminosity 1 ab, the signal
() can be seen after
appropriate kinematic cuts. In particular, when the dark matter is a fermion or
a vector, which is supposed to be singlet under the standard gauge symmetry,
the signal with the mass up to 100 GeV can be tested for the Higgs boson mass
to be 120 GeV.Comment: 13 pages, 11 figures and 1 tabl
Relationships between vegetation change and geomorphic conditions in suburban forests of Japan: Analysis by means of digital aerial photogrammetry and geographical information systems
金沢大学人間社会研究域人間科学系The relationships between successional vegetation change and geomorphic conditions were analyzed by using a high-resolution digital terrain model (DTM) and a time series of converted digital vegetation maps combined within a geographical information system (GIS). The results of the analysis confirmed that the pattern of vegetation change is a function of geomorphic conditions (measured in terms of spatio-statistical values of various parameters and time series of those values). Current geoecological studies are usually carried out by means of detailed field observations with high spatial resolution, and the results of our study suggest that a GIS can easily deal with such data over a large area and long time period. In the study area, unforested s ites were reforested using Japanese red pine (Pinus densiflora) as part of the forest rehabilitation work that occurred in the early 1950s. After that, two main patterns of vegetation change from pine forest to deciduous broadleaved forest occurred. In one type, the deciduous broadleaved forest reappeared quickly. In the other, the pine forests remained for a long time. Stands that underwent relatively rapid succession were found on north-facing gentle slopes close to large bodies of water. Stands that did not undergo rapid succession were found on steeper, warmer, and drier slopes (often south-facing slopes farther from bodies of water). The rate of forest succession towards deciduous broadleaved forest is a function of these geomorphic conditions. This suggests that forest succession is influenced by intermediate factors controlling by geomorphic conditions of site, such as soil moisture and soil thickness
Effects of Yellow-Tinted Lenses on Visual Attributes Related to Sports Activities and Daily Life in Late Middle-aged Adults
The purpose of this study was to clarify the effects of colored lenses on the visual performance of middle-aged people. The subjects were 19 middle-aged people with a mean age of 57.4 ±6.0 years. Five different functional lenses were used in the experiments: colorless lenses and four colored lenses (Light-yellow, Dark-yellow, Light-gray, and Dark-gray). Using each lens type, contrast sensitivity, depth perception, hand–eye coordination, dynamic visual acuity, and visual acuity/low-contrast visual acuity were measured. Visual acuity/low-contrast visual acuity was measured under the four conditions of Evening, Evening + Glare, Day, and Day + Glare. Results showed that dynamic visual acuity and depth perception did not differ among the lens types, but hand–eye coordination measurements had a significantly shorter time with the Light-yellow and Dark-yellow lenses than the Dark-gray lenses. Low-contrast visual acuity under Evening and Evening + Glare conditions tended to be lower with the Dark lenses than the Colorless and Light-yellow lenses. The subjects rated the Yellow lenses as bright in a subjective questionnaire evaluation
Identifying Suspicious Regions of Covid-19 by Abnormality-Sensitive Activation Mapping
This paper presents a fully-automated method for the identification of
suspicious regions of a coronavirus disease (COVID-19) on chest CT volumes. One
major role of chest CT scanning in COVID-19 diagnoses is identification of an
inflammation particular to the disease. This task is generally performed by
radiologists through an interpretation of the CT volumes, however, because of
the heavy workload, an automatic analysis method using a computer is desired.
Most computer-aided diagnosis studies have addressed only a portion of the
elements necessary for the identification. In this work, we realize the
identification method through a classification task by using a 2.5-dimensional
CNN with three-dimensional attention mechanisms. We visualize the suspicious
regions by applying a backpropagation based on positive gradients to
attention-weighted features. We perform experiments on an in-house dataset and
two public datasets to reveal the generalization ability of the proposed
method. The proposed architecture achieved AUCs of over 0.900 for all the
datasets, and mean sensitivity and specificity . The method can also identify notable lesions pointed out in the
radiology report as suspicious regions.Comment: 10 pages, 3 figure
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