Search

Upon infection or brain damage, microglia are activated to play roles in immune responses, including phagocytosis and soluble factor release. However, little is known whether the event of phagocytosis could be a trigger for releasing soluble factors from microglia. In this study, we tested if microglia secrete a neurovascular mediator matrix metalloproteinase-9 (MMP-9) after phagocytosis in vitro. Primary microglial cultures were prepared from neonatal rat brains. Cultured microglia phagocytosed Escherichia coli bioparticles within 2 hr after incubation and started to secrete MMP-9 at around 12 hr after the phagocytosis. A TLR4 inhibitor TAK242 suppressed the E. coli-bioparticle-induced MMP-9 secretion. However, TAK242 did not change the engulfment of E. coli bioparticles in microglial cultures. Because lipopolysaccharides (LPS), the major component of the outer membrane of E. coli, also induced MMP-9 secretion in a dose-response manner and because the response was inhibited by TAK242 treatment, we assumed that the LPS-TLR4 pathway, which was activated by adhering to the substance, but not through the engulfing process of phagocytosis, would play a role in releasing MMP-9 from microglia after E. coli bioparticle treatment. To support the finding that the engulfing step would not be a critical trigger for MMP-9 secretion after the event of phagocytosis in microglia, we confirmed that cell debris and amyloid beta were both captured into microglia via phagocytosis, but neither of them induced MMP-9 secretion from microglia. Taken together, these data demonstrate that microglial response in MMP-9 secretion after phagocytosis differs depending on the types of particles/substances that microglia encountered.

We report 73Ge-NMR measurement on the ferromagnetic superconductor UGe2 at ambient pressure. The observed NMR spectrum supports that the electric field gradient at three inequivalent Ge sites is correctly deduced by a LDA calculation. The temperature dependences of the nuclear spin lattice relaxation rate 1 / T 1 for H 0 ⊥ a (easy axis) and H 0 ∥ a were obtained for the oriented sample. The contrasting behavior in 1 / T 1 for H 0 ⊥ a and H 0 ∥ a reveals that the magnetic fluctuation of UGe2 is highly anisotropic.

Upon infection or brain damage, microglia are activated to play roles in immune responses, including phagocytosis and soluble factor release. However, little is known whether the event of phagocytosis could be a trigger for releasing soluble factors from microglia. In this study, we tested if microglia secrete a neurovascular mediator matrix metalloproteinase-9 (MMP-9) after phagocytosis in vitro. Primary microglial cultures were prepared from neonatal rat brains. Cultured microglia phagocytosed E. coli bio-particles within 2 hours after incubation and started to secrete MMP-9 at around 12 hours after the phagocytosis. A TLR4 inhibitor TAK242 suppressed the E. coli-bio-particle-induced MMP-9 secretion. However, TAK242 did not change the engulfment of E. coli bio-particles in microglial cultures. Because lipopolysaccharides (LPS), the major component of the outer membrane of E. coli, also induced MMP-9 secretion in a dose-response manner and because the response was inhibited by TAK242 treatment, we assumed that the LPS-TLR4 pathway, which was activated by adhering to the substance, but not through the engulfing process of phagocytosis, would play a role in releasing MMP-9 from microglia after E. coli bio-particle treatment. To support the finding that the engulfing step would not be a critical trigger for MMP-9 secretion after the event of phagocytosis in microglia, we confirmed that cell debris and amyloid beta were both captured into microglia via phagocytosis, but neither of them induced MMP-9 secretion from microglia. Taken together, these data demonstrate that microglial response in MMP-9 secretion after phagocytosis differs depending on the types of particles/substances that microglia encountered.

To investigate the electronic state of CeRu2Al10, which exhibits an unusual antiferromagnetic order below TN = 27 K, we measured the electrical resistivity ρ, the transverse magnetoresistance (TMR)...

Much attention has been paid to water-soluble porphyrins and metalloporphyrins as potential sensitizers for photodynamic therapy (PDT). Thus, water-soluble tricationic phosphorus porphyrin complexe...

Much attention has been paid to water-soluble porphyrins and metalloporphyrins as potential sensitizers for photodynamic therapy (PDT). Thus, water-soluble tricationic phosphorus porphyrin complexe...

The flux density distributions in sintered Bi 2 Sr 2 CaCu 2 O x high-T c superconducting specimens were observed by means of a magnetooptic method using iron garnet films. The samples were formed into discs with thicknesses of 60 to 600 ?m and a diameter of 1.5 mm. SEM images showed that specimens consisted of grains with diameters of order 300 ?m. Flux penetrated inhomogeneously into specimens of thickness smaller than the grain diameters. However, flux penetration became homogeneous as the thickness was increased. Preferential flux penetration at grain boundaries was not observed in all specimens. The value of the critical current density, estimated from the flux penetration distance using Bean's model applied to discshaped specimens, was about 104 A/cm2 at 30K, which is nearly equal to the value estimated from the magnetization assuming that the shielding current flows uniformly through the entire specimen.

Magnetic field distributions at the surface of field-oriented polycrystalline YBa 2 Cu 3 O x disks were observed in a flux penetration process by a magneto-optical method using magnetic films, and intergrain and intragrain critical currents ( J ct and J cg ) were investigated. Three garnet films with various saturation fields were used as magnetic films. The value of J ct was investigated using the garnet film with low H s , from the applied field at which the flux penetrates to the center of a specimen. Using the garnet film with high H s , the magnetic field distribution was observed. The magnetic field has a minimum near the edge and is nearly constant ( H 0 ) at the inner region. It turned out that such a distribution is characteristic of superconductors with weak links at the grain boundary. We prove for the first time that the J cg can be estimated from the difference between the applied field and H 0 .

The goal of this research is to realize a new type of physical human-machine interface. In this research, Active Polyhedron can treat virtual three dimensional continuums having many force output points. Active 80-faced Polyhedron can treat virtual objects that are more complex than Active Icosahedron which was previously developed. Towards realizing the overall hardware parts, 120 pieces of new and compact intelligent pneumatic cylinder with length measurement and communication function are designed and constructed. Communication and control system to control input-output data between PC and 120 cylinders was confirmed. Three experiments were carried out, which are position control of the cylinder, shape input experiments and spring motion experiments. In the shape input experiments, inputting shape information of the Active 80-faced Polyhedron to PC is realized. On the other hand, the spring motion experiments establish the stiffness function by changing stiffness coefficient of each intelligent cylinder where the operator can feel its difference. Both experimental results show the effectiveness of the Active Polyhedron for a new human machine interface.

Magnetic field distributions at the surface of field-oriented polycrystalline YBa2Cu3Ox specimens were observed in a flux penetration process by a magneto-optical method, and the values of the magnetic field were estimated using image processing technique. The magnetic field distribution has a minimum near the edge and nearly constant value at the inner region. It turned out from the simulation of field distribution on superconductors with weak-links at the grain boundary that such a distribution is characteristic of superconductors in which the intergrain current is negligible small compared with the intragrain current. We showed that the intragrain critical current can be estimated from the value of the magnetic field at inner region.

The flux density distribution of field-oriented YBa2Cu3Ox polycrystals is observed at flux penetration process by magneto-optical method using iron garnet films placed on the superconductors. In the flux penetration process, flux density shows the distribution as the flux density moderately decreases with the distance from the center and has a minimum near the edge. Such a distribution is explained from the effect of the shielding field arised by each intragrain current. This is a characteristic of such superconductors as intergrain current is negligebly small for intragrain current.

We investigated magnetic flux penetration and trapping processes of Bi2Sr2CaCu2Ox sintered specimens (Tc∼90K) by observing the change of stripe domains of iron garnet films for various temperatures. SEM image showed that sintered specimens consist of the assemblage of randomly oriented frake like grains with the diameters of 50∼200 µm. The flux penetration and trapping processes were inhomogeneous. Averaged critical current Jc estimated from the flux density distribution using Bean’s model was the order of 104 A/cm2 at low temperatures, which are consistent with the results of the magnetization measurements.

Elongatin (4′,5-dihydroxy-2′,5′-dimethoxy-2″,2″-dimethylpyrano[5″,6″-g]isoflavone) was synthesized by an oxidative rearrangement of the corresponding pyronochalcone [6-(1-oxo-3-phenyl-2-propenyl)-4-chromanone] with thallium(III) nitrate and a regioselective reduction of 7-(4-benzoyloxy-2,5-dimethoxyphenyl)-2,3-dihydro-2,2-dimethyl-5-tosyloxy-4H,6H-benzo[1,2-b:5,4-b′]dipyran-4,6-dione with sodium boronydride–palladium chloride, followed by dehydration of the resultant alcohol and hydrolysis. Its angular isomer (4′,5-dihydroxy-2′,5′-dimethoxy-2″,2″-dimethylpyrano[6″,5″-h]isoflavone) was also synthesized from the corresponding pyronochalcone in a similar manner.