Serotonin-containing nerve fibers in the rat spinal cord: electron microscopic immunohistochemistry.

The ultrastructure of the serotonin (5HT) system in the spinal cord of rats was studied by an immunohistochemical peroxidase-antiperoxidase (PAP) method. Under the light microscope, 5HT immunoreactive staining was observed as brown-colored dots in the anterior horn, lateral horn, posterior horn and pericentral canal region. These positively staining dots were probably indicative of 5HT immunoreactive varicosities and nerve terminals. At the ultrastructural level, 5HT immunoreactive nerve fibers appeared as darkly stained varicosities with PAP positive large electron dense vesicles (80-100 nm), as well as small clear vesicles (30-40 nm) finely coated with PAP immunoreactive products. In the anterior horn, some of the 5HT immunoreactive structures were clearly nerve terminals forming asymmetric synaptic contact with soma or dendrites of the anterior horn cells. In the lateral horn, posterior horn and pericentral canal region, however, only 5HT positive varicosities were detected.</p

<Preliminary>An Enzymatic Study of an Oxalate Producing System in Relation to the Glyoxylate Cycle in White-rot Fungus Phanerochaete chrysosporium

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Simulation study on cascaded terahertz pulse generation in electro-optic crystals

We studied cascaded optical rectification processes for intenseterahertz (THz) pulse generation in electro-optic crystals using simulationsbased on one-dimensional coupled propagation equations of THz and opticalfields. We found that under ideal conditions of perfect phase matching andno absorption, cascaded optical rectification processes produce intense THzpulses with efficiencies exceeding the Manley-Rowe limit. Large red shiftingof the pump light spectrum was observed. Effects of finite optical andTHz absorption, phase mismatches, and pulse width were examined usingparameters of a ZnTe crystal pumped by 800 nm pulses. THz field enhancementby multiple pulse pumping was also studied

Improving a Terahertz Time-Domain Spectroscopy Apparatus Using Neodymium Magnets

Abstract. The signal-to-noise ratio obtained from terahertz time-domain spectroscopy is significantly affected by the low available power of terahertz waves. We constructed a terahertz-wave source with emission power enhanced by a magnetic field. The emitter is composed of an InAs wafer and two neodymium magnets. The emitter was irradiated by femtosecond laser pulses. The data quality of terahertz spectroscopic measurements was evaluated, and reduction of error in the data obtained due to the terahertz power enhancement was observed

Observation of salt effects on hydration water of lysozyme in aqueous solution using terahertz time-domain spectroscopy

Terahertz time-domain spectroscopy was used to investigate the salt effect of ammonium sulfate on the dynamics of hydration water of lysozyme in aqueous solution. The absorption coefficient of lysozyme aqueous solutions containing salt was subtracted by that of the water and ammonium sulfate contained in the lysozyme solution. The results revealed that ammonium sulfate increases the absorption coefficient of the hydration water, which indicates that the dynamics of the hydration water becomes faster and/or the number of hydration water molecules decreases with increasing ammonium sulfate concentration

Investigation of spectral properties and lateral confinement of THz waves on a metal-rod-array-based photonic crystal waveguide

Terahertz (THz) waves laterally confined in a 1 mm-thick microstructured planar waveguide are demonstrated on a free-standing metal rod array (MRA), and one apparent rejection band of a transmission spectrum, resembling the bandgap of a photonic crystal, is found in 0.1–0.6 THz. The visibility of the photonic bandgap in the spectral width and power distinction can be manipulated by changing the MRA geometry parameters, including the rod diameter, the interspace between adjacent rods, and the propagation length based on the interactive MRA-layer number. THz transmission ratio enhanced by a large interactive length is verified in 30 MRA layers due to the longitudinally resonant guidance of transverse-magnetic-polarized waveguide modes along the MRA length, which is critical to the interspace width of adjacent rods and the metal coating of the rod surface. For an MRA with respective rod diameter and interspace dimensions of about 0.16 and 0.26 mm, the highest transmission of the guided resonant THz waves are performed at 0.505–0.512 THz frequency with strong confinement on the metal rod tips and a low scattering loss of 0.003 cm−1