Activity and distribution of learning-related neurons in monkey (Macaca fuscata) prefrontal cortex.

The involvement of monkey (Macaca fuscata) prefrontal cortex (PFC) neurons in motor output decisions was studied by recording single neuron activity during 3 tasks: (a) go-left, go-right, or no-go decisions, (b) operant bar press feeding based on discrimination of food and nonfood, and (c) either delayed matching-to-sample (DMS) or DMS with response delay. Combinations of single neuron responses during the 3 tasks suggested 7 types of PFC neurons that were related to attention, choice, task-unique memory, reward anticipation, laterality, initiation of movement, and suppression of movement. The authors suggest that responses of PFC neurons do not depend on physical properties of the stimuli, but on their behavioral significance. PFC neurons might be important for appropriate behavior in response to external stimuli and internal or motivational factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of macrophage colony-stimulating factor on mouse NK 1.1+ cell activity in vivo

The effect of recombinant human macrophage colony-stimulating factor (rhM-CSF) on NK 1.1+ cell activity in vivo and in vitro was studied. An intravenous injection of rhM-CSF increased the numbers of NK 1.1+ cells in mouse spleen and blood and augmented the clearance of Yac-1 cells in vivo. Using a magnetic cell sorter (MACS), we purified NK 1.1+ cells from vehicle-injected and rhM-CSF-injected mouse spleen cells. More than 95% of the collected cells were NK 1.1 antigen-positive. NK 1.1+ cells purified from rhM-CSF-injected mouse spleen cells exhibited (a) higher cytotoxic activity against Yac-1 cells, (b) higher proliferative responsiveness to interleukin (IL)-2 and (c) a greater production of interferon (IFN)-gamma in response to IL-2 and IL-12 compared to cells purified from vehicle-injected mouse spleen cells in vitro. These results suggest that the administration of rhM-CSF increases NK 1.1+ cell numbers and activates the cells in vivo.     

Position-dependent charge-exchange and energy-loss processes for MeV He ions near a crystal surface

Inelastic interaction of fast ions at glancing angles of incidence on a low index crystal surface is described by the probabilities, which depend on the distance of the ion from the surface; the charge state and energy distributions of the scattered ions are found to result from position-dependent interactions along their trajectories in vacuum. A stochastic equation to describe the charge exchange and energy loss of specularly reflected ions is proposed. Taking account of ion scattering at surface steps, the theory is applied to derive the position-dependent probabilities of electron loss and electron capture of MeV ions from the observed charge state and energy distributions of the scattered ions at glancing angle incidence on the (100) surface of SnTe.     

Raman scattering study of the immiscible region in InGaAsP grown by LPE on (100) and (111) GaAs

We have studied the asymmetric broadening of the Raman spectra of In_xGa_1-xAs_yP_1-y grown on GaAs substrates by means of the spatial correlation model. The broadening phenomena was found to be enhanced in the region of immiscibility, in agreement with PL observations. In Raman measurements, the broadening is more enhanced in the samples grown on (100) substrates than in the samples grown on (111) substrates. The enhancement is attributed to the immiscibility included in the samples grown on (100) substrate.     

Kinetics of non-isothermal crystallization process and activation energy for crystal growth in amorphous materials

An equation expressing the volume fraction,x, of crystals precipitating in a glass heated at a constant rate, α, was derived. When crystal particles grow m-dimensionally,x is expressed as In [- ln(1 -x)] = -n (nα - 1.052mE/RT + Constant whereE is the activation energy for crystal growth andn is a numerical factor depending on the nucleation process. When the nuclei formed during the heating at the constant rate,α, are dominant,n is equal tom + 1, and when the nuclei formed in the previous heat-treatment before thermal analysis run are dominant,n is equal tom. The validity and usefulness of this equation was ascertained by applying it to a Li₂O·2SiO₂ glass. A method for determining the values ofn andm from DSC curves was proposed and it was concluded that the modified Ozawa-type plot is very useful and convenient to obtain the activation energy for crystal growth.     

Effects of catalytic graphitization on Vickers microhardness of a phenolic resin carbon and cokes

The effects of catalytic graphitization on Vickers microhardness have been investigated using a typical non-graphitizing phenolic resin carbon and two coking coals. The hardness of the phenolic resin carbon is reduced considerably by the formation of a turbostratic carbon because of catalytic graphitization. However, the hardness of the coking coals was not lowered by catalytic graphitization. The causes of these phenomena are discussed.     

Bilayer polymer coating containing a polyaniline for corrosion protection of iron

A poly(2-N-phenylamino-4,6-dimercapto-S-triazine) (PPDT) layer was first prepared electrochemically on an iron surface. The PPDT layer strongly adsorbed on the surface because of the polar triazine rings of the PPDT molecules. No electrochemical response of the PPDT layer-covered electrode to dissolved Fe(CN)₆³⁻ was observed. This fact indicated that the PPDT layer is an insulating layer with low permeability to dissolved species, and thus acting as a diffusion barrier against agents causing corrosion such as H₂O and O₂. A polymer polyaniline (PANI) layer was electrodeposited on the PPDT layer. This system was conductive because electron transfer through the PPDT layer occurred by electrons hopping utilizing the localized electron density of the triazine ring. The obtained PANI/PPDT bilayer coating greatly lowered the anodic current peak ascribed to the anodic dissolution of iron and the corrosion current. The high anti-corrosion ability was due to a hybrid effect of the PANI layer as an in-situ oxidant and the PPDT layer as a diffusion barrier.     

Ion channeling study of epitaxy of iron based Heusler alloy films on Ge(111)

We have investigated perfection of atomic rows on iron-based Heusler alloy films on Ge(111) planes by using ion channeling technique in order to find the dominant factors for the perfection. Fe₃Si/Ge(111) and Fe₂CoSi/Ge(111) have a high quality of atomic rows at the heterointerface like that of perfect crystals. Fe_3−xMn_xSi/Ge(111) (x = 0.84, 0.72 and 0.36) interfaces have imperfection of atomic rows which may be controlled by both the lattice mismatch with the Ge substrate and the Mn-Si pairs due to the site disorder in the film with the Mn content x > 0.75. Analysis of axial channeling parameters employed in this study is very useful for quantitative evaluation of perfection of atomic rows at the heterointerface.