Highly Transparent and Polarization-Maintained Terahertz Plasmonic Metamaterials Based on Metal-Wire-Woven Hole Arrays: Fundamentals and Characterization of Transmission Spectral Peaks

Metal-hole-supported terahertz (THz) waves through the structure of a metal-wire-woven hole array (MWW-HA) present high-frequency-passed transmittance spectra of one plasmonic metamaterial with artificial plasmonic frequencies, which are inversely proportional to metal-hole widths. For the transmitted THz waves of MWW-HA, transverse-electric (TE) and transverse-magnetic (TM) waveguide modes mix within a symmetric metal-hole boundary. THz resonance waves transversely crossing the holes of MWW-HA are experimentally characterized with spectral peaks in the frequency range of 0.1–2 THz that are correlated with aperture sizes, unit-cell-hole widths, metal-wire thicknesses, and wire-bending angles. The metal-hole-transported resonance waves of MWW-HA are dominated by TE waveguide modes instead of TM ones because a hole width of MWW-HA is approximate to the half wavelength of a resonance wave. The round metal edges of the woven metal wires can minimize the effective optical length of a thick metal hole to transmit THz resonance waves, thereby resulting the smallest rotation angle of linear polarization and high transmittance up to 0.94. An MWW-HA structure is therefore reliable for supporting metal-hole resonance waves with low resistance, whereas a metal-slab-perforated hole array cannot achieve the same result

Risk of nonpsychotic mental disorders development in antiviral-treated mentally healthy chronic hepatitis C patients: A population-based study

Interferon (IFN) is able to induce significant psychiatric side effects in chronic hepatitis C (CHC) patients, whereas the risk of nonpsychotic mental disorder (NPMD) development in antiviral-treated mentally healthy CHC patients remains obscure. We used a population-based study to assess the risk of NPMD development in patients who had undergone antiviral treatment compared with untreated chronic hepatitis C virus (HCV)-infected and nonalcoholic fatty liver disease (NAFLD) patients. Methods: Data were retrieved from Taiwan's National Health Insurance Research Database cohort consisting of 1 million individuals for a longitudinal analysis. A total of 313 mentally healthy CHC patients who received IFN-based antiviral therapy were recruited and compared with those without antiviral therapy and NAFLD patients. The Chi-square test was used to obtain the hazard ratio and 95% confidence interval. Results: Among the 313 CHC patients receiving pegylated interferon/ribavirin therapy, 62 patients (19.8%) were associated with NPMD. In the comparison cohort, composed of 313 age- and sex-matched CHC patients not receiving antiviral therapy, 70 patients (22.4%) were associated with NPMD. The Chi-square analysis revealed that antiviral therapy was not significantly associated with NPMD. The diagnosis of HCV-infected hepatitis was independently associated with NPMD when compared with NAFLD. The hazard ratio was 1.67 (95% confidence interval, 1.11–2.52; p = 0.018). Furthermore, generalized anxiety disorder was specifically higher in HCV-infected patients than those with NAFLD. Conclusion: Patients with HCV infection are at high risk of developing NPMD with or without IFN-based therapy

Volatile Gas Sensing through Terahertz Pipe Waveguide

Gas sensing to recognize volatile liquids is successfully conducted through pipe-guided terahertz (THz) radiation in a reflective and label-free manner. The hollow core of a pipe waveguide can efficiently deliver the sensing probe of the THz confined waveguide fields to any place where dangerous vapors exist. Target vapors that naturally diffuse from a sample site into the pipe core can be detected based on strong interaction between the probe and analyte. The power variation of the THz reflectance spectrum in response to various types and densities of vapors are characterized experimentally using a glass pipe. The most sensitive THz frequency of the pipe waveguide can recognize vapors with a resolution at a low part-per-million level. The investigation found that the sensitivity of the pipe-waveguide sensing scheme is dependent on the vapor absorption strength, which is strongly related to the molecular amount and properties including the dipole moment and mass of a gas molecule

P2-14: Noise Effect to Cross-Modality Stop Signal Task in Patients with Attention-Deficit / Hyperactivity Disorder

Background: Response inhibition has been proposed as a core element of attention-deficit / hyperactivity disorder (ADHD). ADHD has two subtypes: the hyperactivity and combined subtype (ADHDcom) was considered to have more inhibition deficit, while the inattentive subtype (ADHDin) was not (Barkley, 1997). The stochastic resonance model proposed that noise exerts a positive effect on cognitive performance for ADHD (Söderlund et al., 2007). The current study addressed the issue of the facilitation / interference effect of noise on patients with ADHD by adopting a cross-modality stop-signal task. Method: The cross-modality stop signal task contained a visual discrimination task and an auditory stop signal. Participants were asked to respond to the visual stimuli, and they were asked to withhold their response when the stop signal was presented (25% of trials). The stop signal was a pure tone embedded background noise with various sound levels (no noise, 35 dB, 55 dB). The stop signal reaction time (SSRT) was estimated following Logan et al. (1984) as an index for inhibition function. Result: The result revealed that the SSRTs for ADHDcom were significantly longer than those of ADHDin. The noise did not improve inhibition performance; rather, an interference effect was evident for both subtypes of ADHD. Our result failed to support the finding of Söderlund et al. (2007)

Specularly-Reflected Wave Guidance of Terahertz Plasmonic Metamaterial Based on the Metal-Wire-Woven Hole Arrays: Functional Design and Application of Transmission Spectral Dips

Terahertz (THz) plasmonic metamaterial, based on a metal-wire-woven hole array (MWW-HA), is investigated for the distinct power depletion in the transmittance spectrum of 0.1–2 THz, including the reflected waves from metal holes and woven metal wires. Woven metal wires have four orders of power depletion, which perform sharp dips in a transmittance spectrum. However, only the first-order dip at the metal–hole–reflection band dominates specular reflection with a phase retardation of approximately π. The optical path length and metal surface conductivity are modified to study MWW-HA specular reflection. This experimental modification shows that the first order of MWW-HA power depletion is sustainable and sensitively correlated with a bending angle of the woven metal wire. Specularly reflected THz waves are successfully presented in hollow-core pipe wave guidance specified from MWW-HA pipe wall reflectivity