Efficient Optical Modulation of Terahertz Transmission in Organic and Inorganic Semiconductor Hybrid System for Printed Terahertz Electronics and Photonics

Highly efficient optical modulation of terahertz (THz) transmission through Si substrate coated with thin layer of organic π-conjugated materials was investigated under various laser light irradiation conditions using THz time-domain spectroscopy. As in the pioneering work by Yoo et al. [Yoo et al., Applied Physics Letters. 2013;103:151116-1–151116-3.], we also used copper phthalocyanine (CuPc). It was perceived that the charge carrier transfer from Si to CuPc is crucial for the photo-induced metallization and efficient optical modulation of THz transmission. We found that the thickness of CuPc layer is a critical parameter to realize high charge carrier density for efficient THz transmission modulation. We also fabricated a split-ring resonator (SRR) array metamaterial on CuPc-coated Si utilizing superfine inkjet printer and succeeded in obtaining efficient modulation of resonant responses of SRR array metamaterials by laser light irradiation. We have further investigated THz transmission modulation through Si substrates coated with another four solution-processable π-conjugated materials. Two of them are π-conjugated low molecules such as the [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene), and another two are the π-conjugated polymer materials such as poly[5-(2-ethylhexyloxy)-2-methoxycyanoterephthalyliden] (MEH-CN-PPV) and poly(benzimidazobenzophenanthroline) (BBL). Among these four π-conjugated materials, PCBM- and TIPS-pentacene showed better modulation efficiencies even higher than CuPc. Our findings may open the way to fabricating various types of THz active devices utilizing printing technologies

Expression of kininogen, kallikrein and kinin receptor genes by rat cardiomyocytes

AbstractTo ascertain the existence of the kallikrein-kinin system in the heart, we have studied in vivo and in vitro whether rat cardiac tissue expresses kininogen, kallikrein and kinin receptor mRNAs. The reverse transcription-polymerase chain reaction demonstrated that the ventricular myocardium of adult male rats expressed mRNAs for T- and low-molecular-weight (L-) kininogens, tissue kallikreins such as true kallikrein and T-kininogenase, and bradykinin B2 receptor, but not those for high-molecular-weight kininogen and B1 receptor. Lipopolysaccharide (LPS; 0.5 mg/kg, i.v.) increased the levels of mRNA for T-kininogen at 12 h and the bradykinin B1 receptor at 24 h without affecting that for other components. All of these mRNAs for the kallikrein-kinin system were also detected in cultured cardiomyocytes derived from neonatal rat ventricles; dibutyryl cyclic AMP, LPS or inflammatory cytokines such as interleukin-1 and tumor necrosis factor, up-regulated mRNA expression of T-kininogen, T-kininogenase, or B1 receptor in these cells in vitro. These results suggest that there are two kinin-generating systems in rat myocardium comprising T-kininogen/T-kininogenase and L-kininogen/true kallikrein respectively, and that the former may be relatively important in inflammatory diseases or conditions in which cAMP levels increase in cardiomyocytes

Spatio-Temporal Updating in the Left Posterior Parietal Cortex

Adopting an unusual posture can sometimes give rise to paradoxical experiences. For example, the subjective ordering of successive unseen tactile stimuli delivered to the two arms can be affected when people cross them. A growing body of evidence now highlights the role played by the parietal cortex in spatio-temporal information processing when sensory stimuli are delivered to the body or when actions are executed; however, little is known about the neural basis of such paradoxical feelings resulting from such unusual limb positions. Here, we demonstrate increased fMRI activation in the left posterior parietal cortex when human participants adopted a crossed hands posture with their eyes closed. Furthermore, by assessing tactile temporal order judgments (TOJs) in the same individuals, we observed a positive association between activity in this area and the degree of reversal in TOJs resulting from crossing arms. The strongest positive association was observed in the left intraparietal sulcus. This result implies that the left posterior parietal cortex may be critically involved in monitoring limb position and in spatio-temporal binding when serial events are delivered to the limbs

Phytochrome-regulated EBL1 contributes to ACO1 upregulation in rice

The 1-aminocyclopropane-1-carboxylate oxidase gene (ACO1) was upregulated in rice (Oryza sativa L.) phyAphyBphyC mutants lacking any phytochrome and containing the GCC box element, a binding site for rice ethylene-responsive element binding protein 1 (OsEREBP1), in its promoter region. Since the OsEREBP1-like gene EBL1 (OsEREBP1-LIKE 1) was significantly downregulated in phyAphyBphyC mutants, EBL1 was suspected to repress ACO1 expression in wild-type plants. However, ACO1 was downregulated in EBL1 RNA interference plants, and the total length of these plants was slightly shorter than that of wild-type plants. This study shows that EBL1 is positively regulated by phytochrome B and associated with ACO1 upregulation

Ground state of an S=1/2S=1/2 distorted diamond chain - model of Cu3Cl6(H2O)2⋅2H8C4SO2\rm Cu_3 Cl_6 (H_2 O)_2 \cdot 2H_8 C_4 SO_2

We study the ground state of the model Hamiltonian of the trimerized $S=1/2$ quantum Heisenberg chain $\rm Cu_3 Cl_6 (H_2 O)_2 \cdot 2H_8 C_4 SO_2$ in which the non-magnetic ground state is observed recently. This model consists of stacked trimers and has three kinds of coupling constants between spins; the intra-trimer coupling constant $J_1$ and the inter-trimer coupling constants $J_2$ and $J_3$. All of these constants are assumed to be antiferromagnetic. By use of the analytical method and physical considerations, we show that there are three phases on the $\tilde J_2 - \tilde J_3$ plane ($\tilde J_2 \equiv J_2/J_1$, $\tilde J_3 \equiv J_3/J_1$), the dimer phase, the spin fluid phase and the ferrimagnetic phase. The dimer phase is caused by the frustration effect. In the dimer phase, there exists the excitation gap between the two-fold degenerate ground state and the first excited state, which explains the non-magnetic ground state observed in $\rm Cu_3 Cl_6 (H_2 O)_2 \cdot 2H_8 C_4 SO_2$. We also obtain the phase diagram on the $\tilde J_2 - \tilde J_3$ plane from the numerical diagonalization data for finite systems by use of the Lanczos algorithm.Comment: LaTeX2e, 15 pages, 21 eps figures, typos corrected, slightly detailed explanation adde