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Methods for the control of molecular deposition and orientation are critical for the development of organic electronic devices. Here, we show the fabrication of ribbons of the optical material polydiacetylene (PDA) using a controlled evaporative self-assembly method. The ability to form these ribbons is highly dependent on both the side groups on the PDA as well as the solvent used in the preparation. Arrays of ribbons of one type of PDA, poly[1,6-di(N-carbazolyl)-2,4-hexadiyne], with widths on the order of 1–2 µm and lengths of 100s of micrometers, could be successfully obtained with good orientation.
Cognitive–behavioral therapy (CBT) is thought to be useful for chronic pain, with the pathology of the latter being closely associated with cognitive–emotional components. However, there are few resting-state functional magnetic resonance imaging (R-fMRI) studies. We used the independent component analysis method to examine neural changes after CBT and to assess whether brain regions predict treatment response.
We performed R-fMRI on a group of 29 chronic pain (somatoform pain disorder) patients and 30 age-matched healthy controls (T1). Patients were enrolled in a weekly 12-session group CBT (T2). We assessed selected regions of interest that exhibited differences in intrinsic connectivity network (ICN) connectivity strength between the patients and controls at T1, and compared T1 and T2. We also examined the correlations between treatment effects and rs-fMRI data.
Abnormal ICN connectivity of the orbitofrontal cortex (OFC) and inferior parietal lobule within the dorsal attention network (DAN) and of the paracentral lobule within the sensorimotor network in patients with chronic pain normalized after CBT. Higher ICN connectivity strength in the OFC indicated greater improvements in pain intensity. Furthermore, ICN connectivity strength in the dorsal posterior cingulate cortex (PCC) within the DAN at T1 was negatively correlated with CBT-related clinical improvements.
We conclude that the OFC is crucial for CBT-related improvement of pain intensity, and that the dorsal PCC activation at pretreatment also plays an important role in improvement of clinical symptoms via CBT.
Low birth weight was associated with cardiometabolic diseases in adult age. Insulin-like growth factor-1 (IGF-1) has a crucial role in fetal growth and also associates with cardiometabolic risks in adults. Therefore, we elucidated the association between IGF-1 level and serum lipids in cord blood of preterm infants. The subjects were 41 consecutive, healthy preterm neonates (27 male, 14 female) born at <37-week gestational age, including 10 small for gestational age (SGA) infants (<10th percentile). IGF-1 levels and serum lipids were measured in cord blood, and high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC) and very low-density lipoprotein triglyceride (VLDLTG) levels were determined by HPLC method. SGA infants had lower IGF-1 (13.1 ± 5.3 ng/ml), total cholesterol (TC) (55.0 ± 14.8), LDLC (21.6 ± 8.3) and HDLC (26.3 ± 11.3) levels, and higher VLDLTG levels (19.0 ± 12.7 mg/dl) than in appropriate for gestational age (AGA) infants (53.6 ± 25.6, 83.4 ± 18.9, 36.6 ± 11.1, 38.5 ± 11.6, 8.1 ± 7.0, respectively). In simple regression analyses, log IGF-1 correlated positively with birth weight (r = 0.721, P < 0.001), TC (r = 0.636, P < 0.001), LDLC (r = 0.453, P = 0.006), and HDLC levels (r = 0.648, P < 0.001), and negatively with log TG (r = −0.484, P = 0.002) and log VLDL-TG (r = −0.393, P = 0.018). Multiple regression analyses demonstrated that IGF-1 was an independent predictor of TC, HDLC and TG levels after the gestational age and birth weight were taken into account. In preterm SGA infants, cord blood lipids profile altered with the concomitant decrease in IGF-1 level.
To increase X-ray photon number generated by laser-cluster interaction, it is important to understand the dependence of X-ray generation on cluster size. We carried out Xe K-shell X-ray generation using a conical nozzle with Xe clusters, the radius of which was controllable by adjusting the backing pressure. The experiment clarifies the result that the Xe K-shell X-ray photon number increases with increasing cluster radius from 8 to 12 nm, and saturates at the radius between 12 and 17 nm. We also investigated the Xe K-shell X-ray photon number dependence on laser intensity, and found that the threshold laser intensity of the Xe K-shell X-ray generation exists between 2 × 1017 and 5 × 1018 W/cm2.
The near-infrared (NIR) spectral range (2–5 μm) contains a number of interesting features for the study of the interstellar medium. In particular, the aromatic and aliphatic components in carbonaceous dust can be investigated most efficiently with the NIR spectroscopy. We analyze NIR spectra of the diffuse Galactic emission taken with the Infrared Camera onboard AKARI and find that the aliphatic to aromatic emission band ratio decreases toward the ionized gas, which suggests processing of the band carriers in the ionized region.
A 60 GHz tandem coupler using offset broadside coupled lines is proposed in a WLP (Wafer Level Packaging) technology. The fabricated coupler has a core chip area of 750 μm × 385 μm (0.288 mm2). The measured results show an insertion loss of 0.44 dB, an amplitude imbalance of 0.03 dB and a phase difference of 87.6° at 60 GHz. Also the measurement shows an insertion loss of less than 0.67 dB, an amplitude imbalance of less than 0.31 dB, a phase error of less than 3.7°, an isolation of more than 29.7 dB and a return loss of more than 27.9 dB at the input ant coupled ports and more than 14.3 dB at the direct and isolated ports over the frequency band of 57-66 GHz, covering 60 GHz band both in Japan and US. To the best of our knowledge the proposed coupler achieves the lowest ever reported insertion loss and amplitude imbalance for a 3-dB coupler on a silicon substrate. With its superior performance and lower cost compared to the CMOS counterparts, the proposed coupler is a suitable candidate for low-cost high-performance millimeter-wave systems.
We have succeeded in the rapid epitaxial growth of Si, Ge, and SiGe films on Si substrates below 670 ºC by reactive CVD utilizing the spontaneous exothermic reaction between SiH4, GeH4, and F2. Mono-crystalline SiGe epitaxial films with Ge composition ranging from 0.1 to 1.0 have been successfully grown by reactive CVD for the first time.
This technique has also been successfully applied to the growth of these films on silicon-on-glass substrates by a 20 - 50 ºC increase of the heating temperature. Over 10 μm thick epitaxial films at 3 nm/s growth rate are obtained. The etch pit density of the 5.2 μm-thick Si0.5Ge0.5 film is as low as 5 x 106 cm-2 on top. Mobilities of the undoped SiGe and Si films are 180 to 550 cm2/Vs, confirming the good crystallinity of the epitaxial films.
As the binary collision process requires much more computation time, a statistical electron-electron collision model based on modified Langevin equation is developed to reduce it. This collision model and a simple electron-ion scattering model are installed into one-dimensional PIC code, and collisional effects on fast electron generation and transport in fast ignition are investigated. In the collisional case, initially thermal electrons are heated up to a few hundred keV due to direct energy transfer by electron-electron collision, and they are also heated up to MeV by Joule heating induced by electron-ion scattering. Thus the number of low energy component of fast electrons increase than that in the collisionless case.
Within the Herschel key project “The Warm And Dense ISM” (WADI) we systematically observe
a number of prominent photon-dominated regions (PDRs) to measure the impact of varying UV
fields on the energy balance, the chemical and dynamical structure of heated molecular
Near-infrared (NIR; 2.5–5 μm) low-resolution
(λ/Δλ ~ 100) spectra were obtained for a
number of Galactic and extragalactic objects with the Infrared Camera (IRC) in the AKARI
warm mission. These data provide us with the first opportunity to make a systematic study
of the 3.3–3.5 μm PAH features in a galactic scale as well as within an
object. Whereas the 3.3 μm band is well resolved in most spectra, the
3.5 μm band is not clearly separated from the 3.4 μm
band in the IRC spectrum. The intensity ratio of the summation of the 3.4 and
3.5 μm bands to the 3.3 μm band shows a tendency to
increase towards the Galactic center, although a large variation in the ratio is also seen
in a local scale. A search for deuterated PAH features in the 4 μm region
is carried out in IRC NIR spectra. Emission lines originating from the ionized gas
together with the detector anomaly hamper an accurate search at certain wavelengths, but
little convincing evidence has so far been obtained for the presence of significant
features in 4.2–4.7 μm. A conservative upper limit of a few percents is
obtained for the integrated intensity ratio of the 4.4–4.7 μm possible
features to the 3.3–3.5 μm PAH features in the spectra so far
Leachabilities and solubilities of the synthesized iodide sodalite and natural (chloride) sodalite were measured by leach test. The iodide sodalite was synthesized in nitrogen gas flow at 800°C for 2 hours. The crystalline structure of the product was certified by XRD analysis. The natural sodalite containing chlorine was obtained at Bancroft, Canada. The several types of solution were used to evaluate the influence of the solubility of sodalite that included the varied pH and the chemical compositions. The solubilities of chloride sodalite were calculated by the thermodynamics data. The solubility measured for the synthesized iodide sodalite was compared with that calculated. The solubility of the synthesized iodide sodalite was approximately 2 x 10-4 mol/L, which shows a good agreement with the calculated one of the natural sodalite.
Bismuth titanate (Bi4Ti3O12; BIT) -based ferroelectric materials are proposed from the view of the “Site-engineering”, where the Bi-site ions are substituted by lanthanoid ions (La3+ and Nd3+) and Ti-site ions by other ions with higher charge valence (V5+). In the present study, influences of vanadium (V) - substitution for (Bi,M)4Ti3O12 thin films [M = lanthanoid] on the ferroelectric properties are evaluated. V-substituted (Bi,M)4Ti3O12 films have been fabricated using a chemical solution deposition (CSD) technique on the (111)Pt/Ti/SiO2/(100)Si substrate. Remnant polarization of (Bi,La)4Ti3O12 and (Bi,Nd)4Ti3O12 films has been improved by the V-substitution independent of the coercive field. The processing temperature of BLT and BNT films could also be lowered by the V-substitution.
Electrical characteristics of Spindt-type Molybdenum (Mo) field emitter triode devices with varied emitter tip-height have been studied based on device modeling and experiment. Potential and electric field distributions with varied the emitter tip-height has been simulated. It is observed that the electric field of the top of the higher emitter tip was strongly affected with the anode-gate distance and the anode voltage compared to conventional field emitter triode device. Experimental results with varied different tip-height were in good agreement with that of calculated results. We present the possibility of “depletion mode” field emitter triode device.
A novel dynamic circuit composed of amorphous-silicon Schottkybarrier diodes and field-effect transistors has been proposed. The circuit response time is as short as the discharging time of a load capacitor through the driver transistor. The circuit having 1µm-long, self-aligned transistors has been predicted theoretically to be able to be operated at multi-MHz rates. Preliminary experimental results are also presented.
Residual stress in molecular beam epitaxially (MBE) grown GaAs films on 4°-off (100)Si substrates is investigated with X-ray diffraction technique. It is experimentally confirmed that the GaAs lattice suffers tetragonal deformation with the c-axis being . The GaAs lattice tilts by approximately 0.2° towards the tilted direction of the substrate. It is found that two-dimensional compressive stress dominates in GaAs films thinner than 0.3 μm in thickness, while two-dimensional tensile stress dominates in thicker films. The variation of the stress is understood in terms of a combination of misfit stress and thermal stress. The residual tensile stress is larger than 1 × 109 dyn/cm2 in the films thicker than I pm. The effect of the stress on the reliability of semiconductor laser diodes is discussed.
Based upon the thermal-equilibration theory and the annealing of defects introduced at the growing surface of amorphous silicon, the distribution of defect-states in energy and in space is calculated for a comprehensive set of deposition and post-deposition treatment parameters. We include the growth temperature, growth rate, illumination time, illumination intensity, annealing temperature, and annealing time. We compare the theoretical results with experimental data for the dark-conductivity-activation energy and for the fill factor of a solar cell. Agreement between the modelled and the experimental results reconfirms the validity of the assumptions made, and encourages further application of the model to analyses of a wide variety of amorphous silicon devices.
The photocurrent behavior in polydiacetylene (PDA) single crystals of PTS (poly-(2, 4-hexadiyne-1, 6-diol bis(p-toluenesulfonate)) and MADF (poly-(1-(3-(methylamino)phenyl)-4-(3, 5-bis (trifluoromethyl)-phenyl) butadiyne)) have been investigated by using steady state photoconductivity measurements. These measurements were carried out as a function of sample temperature and incident light polarization. PTS and MADF show completely different behavior in these measurements. These differences between PTS and MADF suggest that the side groups of PDA strongly influence the photocurrent behavior in PDA.