Fabrication of 3-D photonic band gap material of TiO2 by microtransfer molding and sol-gel processing

Photonic band gap (PBG) crystals are artificially engineered periodic dielectric structures which exhibit frequency regions in which electromagnetic (EM) waves cannot propagate in certain directions. By using the master mold with desired features, an elastomeric mold of poly (dimethylsiloxane) (PDMS) with a relief structure on its surface was shaped. From these elastromeric molds, one-, two-, and multi-layer PBG samples were formed using microtransfer molding. The sol-gel solutions with the precursor of titanium diisopropoxide bis (2, 4-pentadionate)(TDBP), tetraethyl orthotitanate (TEOT) and titanium isopropoxide (TIPP) were infiltrated into the samples, respectively by spin coating. The infiltrated samples were sintered at 5500C. The sintered samples were characterized by optical microscopy, SEM and FTIR. Results show that the sintered samples experience large shrinkage (up to 40%) during heat treatment and therefore the structures had a low filling ration. The filling ratio can be enhanced by increasing the concentration of the precursor in the sol-gel. FTIR data showed that there were strong absorption peaks around 1500 cm−1 with a transmittance of 92.5% due to the existence of the first band gap of PBG structures. A sintered 4-layer sample was successfully obtained by infiltrating the sol of TDBP (26wt%) six times into the pattern through spin coating. It is likely that this approach can yield high quality three-dimensional PBG structures of Ti02

Physiological Signals based Day-Dependence Analysis with Metric Multidimensional Scaling for Sentiment Classification in Wearable Sensors

The interaction of the affective has emerged in implicit human-computer interaction. Given the physiological signals in the recognition process of the affective, the different positions by which the physiological signal sensors are installed in the body, along with the daily habits and moods of human beings, influence the affective physiological signals. The scalar product matrix was calculated in this study based on metric multidimensional scaling with dissimilarity matrix. Subsequently, the matrix of individual attribute reconstructs was obtained using the principal component factor. The method proposed in this study eliminates day dependence, reduces the effect of time in the physiological signals of the affective, and improves the accuracy of affection classification

Plasma transferred arc surface alloying of Cr-Ni-Mo powders on compacted graphite iron

A Cr-Ni-Mo overlayer was deposited on the surface of compacted graphite iron (CGI) by the plasma transferred arc (PTA) alloying technique. The microstructure of Cr-Ni-Mo overlayer was characterized by optical microscopy (OM), scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), and X-ray diffractometer (XRD). Results show that the cross-section consists of four regions: alloying zone (AZ), molten zone (MZ), heat affected zone (HAZ), and the substrate (SUB). The microstructure of AZ mainly consists of cellular γ-(Fe, Ni) solid solution, residual austenite and a network of eutectic Cr7C3 carbide while the MZ area has a typical feature of white cast iron (M3C-type cementite). The martensite/ledeburite double shells are observed in the HAZ. With decreasing the concentration of Cr-Ni-Mo alloys, the fracture mode changes from ductile in the AZ to brittle in the MZ. The maximum hardness of the AZ (450 HV0.2) is lower than that of the MZ (800 HV0.2). The eutectic M3C and M7C3 carbides increase the microhardness, while the austenite decreases that of the AZ

Universal enhancement of vacancy diffusion by Mn inducing anomalous Friedel oscillation in concentrated solid-solution alloys

We present a proof-of-principle demonstration of a universal law for the element Mn, which greatly enhances vacancy diffusion through an anomalous Friedel Oscillation effect in a series of Ni-based concentrated solid-solution alloys, regardless of the type of atom involved. The antiferromagnetic element Mn possesses a unique half-filled 3d electron structure, creating split virtual bound states near the Fermi energy level and producing a large local magnetic moment after vacancy formation. The resultant electron spin oscillations reduce the number of electrons involved in charge density oscillations, destroying charge screening and lowering potential interaction at the saddle point between the vacancy and diffusing atom. This ultimately facilitates vacancy diffusion by reducing energy level variations of conduction band electrons during the diffusion process. These findings offer valuable insights into atom diffusion mechanisms and open up new avenues for manipulating defect properties through unique element design, thereby enabling the creation of high-performance alloys in a broad range of fields

Activated IL-23/IL-17 pathway closely correlates with increased Foxp3 expression in livers of chronic hepatitis B patients

<p>Abstract</p> <p>Background</p> <p>Foxp3 protein plays a critical role in mediating the inflammatory response and can inhibit the proinflammatory IL-23/IL-17 pathway. However, the molecular interplay of Foxp3 and the IL-23/IL-17 pathway in patients with chronic hepatitis B (CHB) remains unclear. To this end, we analyzed the expression patterns of Foxp3- and IL-23/IL-17 pathway-related proinflammatory cytokines in 39 patients with acute-on-chronic liver failure, 71 patients with CHB and 32 healthy controls.</p> <p>Results</p> <p>Foxp3 expression was found to be elevated in and mainly expressed by the CD4⁺T cell sub-population of peripheral blood mononuclear cells and liver tissues of patients with hepatitis B. The intrahepatic expression of Foxp3 strongly correlated with the copies of HBV DNA and the concentration of surface antigen, HBsAg. IL-23/IL-17 pathway-related proinflammatory cytokines were also found to be significantly increased in patients' liver tissues, as compared to healthy controls. Moreover, Foxp3 expression was strikingly correlated with the production of these cytokines in liver tissues of CHB patients.</p> <p>Conclusions</p> <p>The closely-correlated increase of Foxp3 and IL-23/IL-17 pathway activity in HBV-infected livers suggests that the proinflammatory IL-23/IL-17 pathway had not been effectively suppressed by the host immune machinery, such as Treg (Foxp3) cells. Constitutive activation of the IL-23/17 pathway, thus, may support the chronic hepatitis B state.</p

High-yield wafer-scale fabrication of ultralow-loss, dispersion-engineered silicon nitride photonic circuits

Low-loss photonic integrated circuits (PIC) and microresonators have enabled novel applications ranging from narrow-linewidth lasers, microwave photonics, to chip-scale optical frequency combs and quantum frequency conversion. To translate these results into a widespread technology, attaining ultralow optical losses with established foundry manufacturing is critical. Recent advances in fabrication of integrated Si3N4 photonics have shown that ultralow-loss, dispersion-engineered microresonators can be attained at die-level throughput. For emerging nonlinear applications such as integrated travelling-wave parametric amplifiers and mode-locked lasers, PICs of length scales of up to a meter are required, placing stringent demands on yield and performance that have not been met with current fabrication techniques. Here we overcome these challenges and demonstrate a fabrication technology which meets all these requirements on wafer-level yield, performance and length scale. Photonic microresonators with a mean Q factor exceeding 30 million, corresponding to a linear propagation loss of 1.0 dB/m, are obtained over full 4-inch wafers, as determined from a statistical analysis of tens of thousands of optical resonances and cavity ringdown with 19 ns photon storage time. The process operates over large areas with high yield, enabling 1-meter-long spiral waveguides with 2.4 dB/m loss in dies of only 5x5 mm size. Using a modulation response measurement self-calibrated via the Kerr nonlinearity, we reveal that, strikingly, the intrinsic absorption-limited Q factor of our Si3N4 microresonators exceeds a billion. Transferring the present Si3N4 photonics technology to standard commercial foundries, and merging it with silicon photonics using heterogeneous integration technology, will significantly expand the scope of today's integrated photonics and seed new applications

Fluctuation of primary motor cortex excitability during cataplexy in narcolepsy

Objective Cataplexy is a complicated and dynamic process in narcolepsy type 1 (NT1) patients. This study aimed to clarify the distinct stages during a cataplectic attack and identify the changes of the primary motor cortex (PMC) excitability during these stages. Methods Thirty-five patients with NT1 and 29 healthy controls were recruited to this study. Cataplectic stages were distinguished from a cataplectic attack by video-polysomnogram monitoring. Transcranial magnetic stimulation motor-evoked potential (TMS-MEP) was performed to measure the excitability of PMC during quiet wakefulness, laughter without cataplexy, and each cataplectic stage. Results Based on the video and electromyogram observations, a typical cataplectic attack (CA) process is divided into four stages: triggering (CA1), resisting (CA2), atonic (CA3), and recovering stages (CA4). Compared with healthy controls, NT1 patients showed significantly decreased intracortical facilitation during quiet wakefulness. During the laughter stage, both patients and controls showed increased MEP amplitude compared with quiet wakefulness. The MEP amplitude significantly increased even higher in CA1 and 2, and then dramatically decreased in CA3 accompanied with prolonged MEP latency compared with the laughter stage and quiet wakefulness. The MEP amplitude and latency gradually recovered during CA4. Interpretation This study identifies four stages during cataplectic attack and reveals the existence of a resisting stage that might change the process of cataplexy. The fluctuation of MEP amplitude and MEP latency shows a potential participation of PMC and motor control pathway during cataplexy, and the increased MEP amplitude during CA1 and 2 strongly implies a compensatory mechanism in motor control that may resist or avoid cataplectic attack