164 research outputs found
直接接合によって異なる機能層を埋め込んだセンサー・パワーデバイス用シリコンウェーハ
Tohoku University田中秀治課
Dust coagulation and fragmentation in a collapsing cloud core and their influence on non-ideal magnetohydrodynamic effects
We determine the time evolution of the dust particle size distribution during
the collapse of a cloud core, accounting for both dust coagulation and dust
fragmentation, to investigate the influence of dust growth on non-ideal
magnetohydrodynamic effects.The density evolution of the collapsing core is
given by a one-zone model. We assume two types of dust model: dust composed
only of silicate (silicate dust) and dust with a surface covered by
ice ( ice dust). When only considering
collisional coagulation, the non-ideal magnetohydrodynamic effects are not
effective in the high-density region for both the silicate and
ice dust cases. This is because dust coagulation reduces the
abundance of small dust particles, resulting in less efficient adsorption of
charged particles on the dust surface. For the silicate dust case, when
collisional fragmentation is included, the non-ideal magnetohydrodynamic
effects do apply at a high density of $n_{\mathrm{H}}>10^{12} \
\mathrm{cm^{-3}}\mathrm{H_{2}O}\mathrm{H_{2}O}n_{\mathrm{H}}\gtrsim 10^{14} \ \mathrm{cm^{-3}}$, even when
collisional fragmentation is considered. Our results suggest that it is
necessary to consider both dust collisional coagulation and fragmentation to
activate non-ideal magnetohydrodynamic effects, which should play a significant
role in the star and disk formation processes.Comment: Accepted for publication in MNRAS. 17 pages, 11 figure
A Notion of Adjoint Spectrum in the Application to Air-pollution Monitoring
This report deals with a notion of adjoint spectrum which is applicable to air-pollution monitoring by using pulsed lasers. Both Raman and absorption spectra of multiple gas complex are linear combinations of the spectra, each of which is specific to a gas species and its magnitude is proportional to the density. An extended formulation of the method of least squares is made in terms of a new notion, adjoint spectra, which visualizes the structure of the numerical filter. Applications of the derived numerical filters to the two methods are shown and features are described about the synthesized filters
A Performance Analysis For An Air-Pollution Monitoring Using A Pulsed Dye Laser
The maximally attainable accuracy of an airpollution monitoring system is investigated. The system is composed of a tunable pulsed dye laser as the light source, photodiodes as the opto-electric converter and a low noise electronic signal processor specifically designed by the authors. The extreme value of the accuracy is given in terms of the standard deviation of the attenuation. The value is 3.4×10(-4)[Nep√(pulse number)] for an averaged value for multiple laser shots. Also the wavelength reproduceability of a dye laser was examined, which resulted in that a computer should take a part in the wavelength control in order that this method should be feasible
Improved Recovery of Exfoliated Colonocytes from Feces Using Newly Developed Immunomagnetic Beads
We demonstrated the feasibility of a new methodology for isolating colonocytes from feces. To reduce costs and improve the recovery rate of colonocytes from feces, we attempted to develop new immunomagnetic beads. Several sizes of magnetic beads were prepared and tagged with a monoclonal antibody against EpCAM. We made several new monoclonal antibodies against EpCAM, and each monoclonal antibody was tagged to the magnetic beads. In the simulation, the most efficient recovery of HT-29 cells was obtained using the smallest size of beads. Also, beads tagged with a monoclonal antibody with a higher affinity against EpCAM had a higher recovery rate. Similar results were obtained when the smallest size of beads with the highest-affinity monoclonal antibody was applied to clinical samples. The newly developed immunomagnetic beads may be useful for isolating colorectal cancer cells from feces, enabling the cytological or molecular biological diagnosis of CRC
Learning-dependent structural plasticity of intracortical and sensory connections to functional domains of the olfactory tubercle
The olfactory tubercle (OT), which is a component of the olfactory cortex and ventral striatum, has functional domains that play a role in odor-guided motivated behaviors. Learning odor-guided attractive and aversive behavior activates the anteromedial (am) and lateral (l) domains of the OT, respectively. However, the mechanism driving learning-dependent activation of specific OT domains remains unknown. We hypothesized that the neuronal connectivity of OT domains is plastically altered through olfactory experience. To examine the plastic potential of synaptic connections to OT domains, we optogenetically stimulated intracortical inputs from the piriform cortex or sensory inputs from the olfactory bulb to the OT in mice in association with a food reward for attractive learning and electrical foot shock for aversive learning. For both intracortical and sensory connections, axon boutons that terminated in the OT domains were larger in the amOT than in the lOT for mice exhibiting attractive learning and larger in the lOT than in the amOT for mice exhibiting aversive learning. These results indicate that both intracortical and sensory connections to the OT domains have learning-dependent plastic potential, suggesting that this plasticity underlies learning-dependent activation of specific OT domains and the acquisition of appropriate motivated behaviors
Role of the VEGF-Flt-1-FAK pathway in the pathogenesis of osteoclastic bone destruction of giant cell tumors of bone
BACKGROUND: Giant cell tumors (GCTs) of bone are primary benign bone tumors that are characterized by a high number of osteoclast-like multinuclear giant cells (MNCs). Recent studies suggest that the spindle-shaped stromal cells in GCTs are tumor cells, while monocyte-like cells and MNCs are reactive osteoclast precursor cells (OPCs) and osteoclasts (OCs), respectively. In this study, we investigated the pathogenesis of osteoclastic bone destruction in GCTs by focusing on the role of the vascular endothelial growth factor (VEGF)-Flt-1 (type-1 VEGF receptor)-focal adhesion kinase (FAK) pathway. METHODS: The motility of OPCs cells was assessed by a chemotaxis assay and the growth of OPCs was examined using a cell proliferation assay. The expression of VEGF and activation of Flt-1 and FAK in clinical GCT samples and in OPCs were detected by immunohistochemistry and immunoblotting. The correlation between the expression levels of activated Flt-1 and FAK and clinical stages of GCTs was investigated by immunohistochemistry. RESULTS: In GCT samples, CD68, a marker of OPCs and OCs, co-localized with Flt-1. Conditioned media from GCT tissue (GCT-CM) enhanced the chemotaxis and proliferation of OPCs. GCT-CM also stimulated FAK activation in OPCs in vitro. Moreover, there was a correlation between the clinical stage of GCTs and the expression of tyrosine-phosphorylated Flt-1 and FAK. CONCLUSIONS: Our results suggest that the VEGF-Flt-1-FAK pathway is involved in the pathogenesis of bone destruction of GCTs
Serum amyloid A-induced IL-6 production by rheumatoid synoviocytes
AbstractIn this study, we investigated the role of serum amyloid A protein (SAA) in the production of interleukin-6 (IL-6) using rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS). Recombinant SAA stimulation induced the production of pro-inflammatory cytokine, IL-6, from RA-FLS. The signaling events induced by SAA included the activation of the mitogen-activated protein kineases, p38 and JNK1/2 and the activation of nuclear factor-kappa B (NF-κB). Inhibitor studies have shown SAA-induced IL-6 production to be down-regulated by NF-κB inhibition and partially inhibited by p38 or JNK inhibitors. Our findings demonstrate that SAA is a significant inducer of IL-6, which is critically involved in RA pathogenesis
Occurrence of silk stitch abscess after surgery in patients with oral squamous cell carcinoma
Objectives: To elucidate the predisposing factors and clinical characteristics related to the occurrence of stitch
abscess after surgery in patients with oral squamous cell carcinoma (SCC).
Patients
and
Methods: The subjects were 232 patients who underwent excision and/or reconstruction and/or neck
dissection for oral SCC using silk sutures for high ligation of the blood vessels. Detection rates and characteristics of patients with stitch abscess were retrospectively evaluated by comparing patients with and without stitch
abscesses after surgery diagnosed by ultrasonography and findings of various modalities in 232 patients. Several
echogenic dots with subtle acoustic shadows in a hypoechoic mass were identified as the characteristic findings of
stitch abscess on US. The patient groups with and without stitch abscess were compared with respect to various
factors to identify those that predispose to the occurrence of stitch abscess. The factors analyzed included patients'
sex and age, chemotherapy treatment, radiotherapy treatment, the presence of a history of allergy, and blood test
results.
Results: A significant correlation was found between the occurrence of stitch abscess and age, liver function
abnormalities on blood tests, and the presence of a history of allergy. Multiple stitch abscesses clearly tended to
occur more often than single ones in patients with stitch abscess.
Conclusions: The occurrence of stitch abscesses was related to age, liver dysfunction, and/or the presence of allergies. When diagnosing stitch abscess, the occurrence of multiple stitch abscesses is important
Correlation analysis between gut microbiota alterations and the cytokine response in patients with coronavirus disease during hospitalization
The role of the intestinal microbiota in coronavirus disease 2019 (COVID-19) is being elucidated. Here, we analyzed the temporal changes in microbiota composition and the correlation between inflammation biomarkers/cytokines and microbiota in hospitalized COVID-19 patients. We obtained stool specimens, blood samples, and patient records from 22 hospitalized COVID-19 patients and performed 16S rRNA metagenomic analysis of stool samples over the course of disease onset compared to 40 healthy individual stool samples. We analyzed the correlation between the changes in the gut microbiota and plasma proinflammatory cytokine levels. Immediately after admission, differences in the gut microbiota were observed between COVID-19 patients and healthy subjects, mainly including enrichment of the classes Bacilli and Coriobacteriia and decrease in abundance of the class Clostridia. The bacterial profile continued to change throughout the hospitalization, with a decrease in short-chain fatty acid-producing bacteria including Faecalibacterium and an increase in the facultatively anaerobic bacteria Escherichia-Shigella. A consistent increase in Eggerthella belonging to the class Coriobacteriia was observed. The abundance of the class Clostridia was inversely correlated with interferon-γ level and that of the phylum Actinobacteria, which was enriched in COVID-19, and was positively correlated with gp130/sIL-6Rb levels. Dysbiosis was continued even after 21 days from onset. The intestines tended to be an aerobic environment in hospitalized COVID-19 patients. Because the composition of the gut microbiota correlates with the levels of proinflammatory cytokines, this finding emphasizes the need to understand how pathology is related to the temporal changes in the specific gut microbiota observed in COVID-19 patients.
IMPORTANCE There is growing evidence that the commensal microbiota of the gastrointestinal and respiratory tracts regulates local and systemic inflammation (gut-lung axis). COVID-19 is primarily a respiratory disease, but the involvement of microbiota changes in the pathogenesis of this disease remains unclear. The composition of the gut microbiota of patients with COVID-19 changed over time during hospitalization, and the intestines tended to be an aerobic environment in hospitalized COVID-19 patients. These changes in gut microbiota may induce increased intestinal permeability, called leaky gut, allowing bacteria and toxins to enter the circulatory system and further aggravate the systemic inflammatory response. Since gut microbiota composition correlates with levels of proinflammatory cytokines, this finding highlights the need to understand how pathology relates to the gut environment, including the temporal changes in specific gut microbiota observed in COVID-19 patients
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