Among intravital imaging instruments, the intravital two-photon fluorescence excitation microscope has the advantage of enabling real-time 3D fluorescence imaging deep into cells and tissues, with reduced photobleaching and photodamage compared with conventional intravital confocal microscopes. However, excessive motion of organs due to involuntary movement such as breathing may result in out-of-focus images and severe fluorescence intensity fluctuations, which hinder meaningful imaging and analysis. The clinically approved alpha-2 adrenergic receptor agonist dexmedetomidine was administered to mice during two-photon fluorescence intravital imaging to alleviate this problem. As dexmedetomidine blocks the release of the neurotransmitter norepinephrine, pain is suppressed, blood pressure is reduced, and a sedation effect is observed. By tracking the quality of focus and stability of detected fluorescence in two-photon fluorescence images of fluorescein isothiocyanate-sensitized liver vasculature in vivo, we demonstrated that intravascular dexmedetomidine can reduce fluorescence fluctuations caused by respiration on a timescale of minutes in mice, improving image quality and resolution. The results indicate that short-term dexmedetomidine treatment is suitable for reducing involuntary motion in preclinical intravital imaging studies. This method may be applicable to other animal models.

We demonstrate the tungsten disulfide (WS2) thin film catalysts prepared by the sulfurization of vacuum deposited WO3 thin films for efficient hydrogen production with over 90% Faradaic efficiency. The 23-nm-thick WS2 thin film catalyst heterojunction with p-type silicon photocathode could exhibit a photocurrent density of 8.3 mA/cm2 at 0 V versus a reversible hydrogen electrode (RHE), a low onset potential of 0.2 V versus RHE when photocurrent density reaches −1 mA/cm2 and long-term stability over 10 h. The enhanced catalytic activities of WS2/p-Si photocathodes compared with the bare p-Si photocathode originate from a number of edge sites in the synthesized polycrystalline thin films, which could act as hydrogen evolution catalyst.

Background: Mortality associated with depression may be influenced by severity of depression and gender. We investigated the differential impacts on all-cause mortality of late-life depression by the type of depression (major depressive disorder, MDD; minor depressive disorder, MnDD; subsyndromal depression, SSD) and gender after adjusting comorbid conditions in the randomly sampled elderly.

Methods: One thousand community-dwelling elderly individuals were enrolled. Standardized face-to-face clinical interviews, neurological examination, and physical examination were conducted to diagnose depressive disorders and comorbid cognitive disorders. Depressive disorders were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) criteria and SSD to study-specific operational criteria. Five-year survivals were compared between groups using Cox proportional hazards models.

Results: By the end of 2010, 174 subjects (17.4%) died. Depressive disorder (p = 0.001) and its interaction term with gender (p < 0.001) were significant in predicting five-year survival. MDD was an independent risk factor for mortality in men (hazard ratio = 3.65, 95% confidence interval = 1.67–7.96) whereas MnDD and SSD were not when other risk factors were adjusted.

Conclusions: MDD may directly confer the risk of mortality in elderly men whereas non-major depression may be just an indicator of increased mortality in both genders.

A 1MV AMS was installed in KIGAM (Korea Institute of Geoscience and Mineral Resources). After 4 months of installation, the AMS started normal operation from January 2008. This multi-element AMS was developed by HVEE to measure 14C, 10Be, and 26Al. The results of an acceptance test demonstrate that this machine is capable of routine 14C age dating and of measurements of other radioisotopes in terms of accuracy and precision as well as the background level. After installation, an investigation aimed at determining the stable operating conditions was conducted, and background levels were determined to be as low as 10–15 for 14C and 10–14 for 10Be and 26Al.

Novel ultrafine eutectic composites containing structural and spatial heterogeneities have been systematically developed in an Mg–Cu–Zn ternary system. Microstructural investigations of the ultrafine eutectic composites revealed that the bimodal eutectic structure consists of a mixture of cellular-type fine (α-Mg + MgZn2) and anomalous-type coarse (α-Mg + MgZn2 + MgCuZn) eutectic structures. An Mg72Cu5Zn23 alloy composed of the bimodal eutectic structure without micron-scale α-Mg dendrites presents a strong improvement of yield strength up to 455 MPa with a decent plastic strain of 5%. The rotation of the bimodal eutectic colony along the interfaces is considered to be an effective way to dissipate the stress localization thus enhancing the macroscopic plasticity.

The dielectric and magnetic properties were investigated in Ta-substituted BiFeO3 polycrystalline ceramics synthesized by a solid-state reaction. The Ta substitution decreased the grain size by two orders of magnitude compared with that of unsubstituted ceramics and increased the electrical resistivity by 6 orders of magnitude. The high resistivity and low dielectric loss allowed the dielectric constant to be determined at room temperature. The magnetic hysteresis loops were observed in the Ta-substituted BiFeO3, and the appearance of ferromagnetism was closely associated with the distortion of the oxygen octahedra by the Ta substitution. The coupling between the electric and magnetic dipoles was examined by determining the changes of the dielectric constant with the external magnetic field.

Sol-gel derived photosensitive inorganic-organic hybrid materials (Photo-HYBRIMER) containing a large quantity of photoactive molecules exhibit the large changes in both refractive index (over 10-2) and volume (over 30%) on UV exposure. The materials could be used for direct fabrication of micro-optical devices using holographic interference. With the change of the beam number for holographic interference (1-beam, 2-beam, 3-beam and 4-beam interference), various typed micro-optical devices (Fresnel-type lens, 1D- and 2D-typed diffraction gratings) could be easily fabricated. Importantly, the fabricated micro-optical devices exhibited the very homogeneous surface structures and good optical performance.

SiON thin films were deposited by plasma-enhanced chemical vapor deposition method at 350 °C using N2O/SiH4 gas mixtures as precursors. As-deposited SiON films were annealed in different gas atmospheres (air, N2, and O2) and at different annealing temperatures (800 oC ∼ 1100 oC). Effects of annealing atmosphere on the Si-O, Si-N, Si-H, and N-H bonding characteristics in SiON films and their structural and optical properties have been investigated. Cross-sectional and planar microstructures were characterized by scanning electron microscopy and atomic force microscopy, and crystallinity was investigated by X-ray diffraction. Chemical bonding characteristics and optical properties SiON films were studied using fourier transform infrared spectroscopy and prism coupler. Xray diffractions showed no evidence of any crystals in all SiON films. The deposition rate strongly depended on the processing parameters such as radio frequency (rf) power, N2O/SiH4 flow ratio, and SiH4 flow rate. Deposition rate increased as N2O/SiH4 flow ratio increased and SiH4 flow rate increased. It was possible to obtain SiON films with surface roughness of about 1 nm and a high deposition rate of about 4 μm/h when the processing parameters were optimized as rf power of 200 W, N2O/SiH4 flow ratio of 3, SiH4 flow rate of 100 sccm. It was observed that the intensity and the shift of the Si-O stretch and Si-N peaks depended on the annealing atmosphere as well as the annealing temperature. The intensity of Si-O peaks increased in the samples annealed in oxygen atmosphere, but it decreased in the samples annealed in nitrogen atmosphere. The intensity of Si-N peak decreased in the samples annealed in oxygen atmosphere, but it increased in the samples annealed in nitrogen atmosphere. The position of Si-O peaks shifted from 1030 nm to 1140 nm in the samples annealed both in oxygen and in nitrogen atmosphere. It was also observed that the intensities of Si-H (∼2250 cm−1) and N-H (∼3550 cm−1) peaks decreased apparently as the annealing temperature increased in all annealed samples.

The integrated CVD-PVD Al plug process was successfully applied to a sub-quarter micron device for the simultaneous formation of plugs and wires. The effects of the underlayer on the via filling and the microstructure of the CVD-PVD Al films were investigated. Three types of underlayers were examined in this work: the Ti film deposited by the ionized PVD (I-PVD) method, the MOCVD TiN film stacked on the I-PVD Ti film, and the PVD Al film deposited on the I-PVD Ti film. Excellent via filling was achieved by employing the MOCVD TiN/I-PVD Ti or the PVD Al/I-PVD Ti as an underlayer. When only I-PVD Ti film was used as an underlayer, complete via filling was not obtained, because the CVD Al film sealed the top of vias. The CVD-PVD Al film deposited on the PVD Al/I-PVD Ti underlayer also showed excellent crystallographic texture of Al <111> and surface morphology, which is superior to those of the CVD-PVD Al film deposited on the MOCVD TiN/I-PVD Ti underlayer.

TaCN films were deposited at low temperature (≤400 °C) by metallorganic chemical vapor deposition (MOCVD) using pentakis(diethylamido)tantalum (PDEAT) as a precursor. The activation energy of the surface reaction is about 0.79 eV and the maximum deposition rate is about 100 Å/min at 350 °C. The resistivity of the as-deposited film decreases as the deposition temperature increases and the minimum value of resistivity obtained is 6000 μΩ-cm for the sample deposited at 400 °C. Major chemical elements in the films were detected as Ta, C, and N with some amounts of O by Auger electron spectroscopy (AES). By x-ray photoelectron spectroscopy (XPS), it is identified that the most of carbon in the films was bonded to Ta. The microstructural investigation using high resolution transmission electron microscopy reveals a nanocrystalline phase with an average grain size of about 30 Å. Preliminary investigation of the diffusion barrier property for copper showed that the 300 Å of TaCN diffusion barrier was failed after annealing at 500°C for 1 hr.

In this paper, various elastic parameters of heavily boron-doped silicon layer have been extracted by eliminating the misfit dislocations in the layer. The dislocation-free silicon membranes doped with the boron concentration of 1.3 × 1020 atoms/cm3 have been fabricated and the Young’s modulus of 1.45 × 1012 dyn/cm2 and residual tensile stress of 2.7 × 109 dyn/cm2 have been extracted by blister method. From the Young’s modulus and residual stress, the residual tensile strain of 1.34 × 10−3, lattice constant of 5.424 Å, and misfit coefficient of 1.03 × 10−23 cm3/atom have been calculated. These parameters are very similar to those obtained from X-ray diffraction analysis and theory.

In this paper, feasibility of crystalline silicon (c-Si) substrate for transmissive active matrix liquid crystal displays (AM-LCDs) has been investigated. The transparent pixel areas of AM-LCD were formed by vertical etching of (110) silicon substrate using anisotropie etching property of aqueous KOH. Combining this vertical etching process with the conventional MOSFET fabrication process, the pixel switching devices, peripheral circuits and transparent apertures were successfully integrated on the same c-Si substrate. The pixel NMOS devices exhibit an electron mobility of about 600cm2/V-s, a subthreshold slope of 65mV/decade and ON/OFF current ratio of 9 decades at 5V drain voltage. And the gate delay time is 3.3ns at 10V power voltage, measured from a ring oscillator which has enhancement-load type NMOS inverters having the (W/L) iload- (W/L) driverer of 25μm/15μm - 50μm/10μm.

We have studied the growth of microcrystalline silicon (μc-Si) and amorphous silicon (a-Si:H) by layer by layer deposition technique, where the deposition and the radical exposure are done alternatively. He or hydrogen plasma exposure gives rise to the etching effect of both μc-Si and a-Si:H even though the etch rate by He plasma is much smaller. The long exposure of hydrogen radical on a-Si:H gives rise to the formation of μc-Si at low substrate temperature (Ts), whereas the hydrogen content decreases at high Ts. The growth mechanism of the crystallite is proposed on the basis of experimental results.

We have studied the depositions of amorphous silicon, silicon carbon alloy, doped microcrystalline silicon in order to apply these films as the component materials for the p-i-n and double stacked solar cells. We have obtained low band gap a-Si:H by decreasing the deposition rate under the proper preparation conditions and highly conductive, thin microcrystalline Si and SiC layers. We have developed a stable a-Si/a-Si double stacked solar cell with a conversion efficiency of ∼ % using narrow band gap a-Si:H as a i-layer of bottom cell.The performance of this cell does not degrade until 100 hrs illumination under 350 mW/cm2.

We have studied the effect of RF power on the properties of Si thin films prepared by a conventional plasma and remote plasma(RP)- CVD. The structure of the Si film changes from amorphous to crystalline with increasing RF power in RP-CVD. However, the structure of Si film deposited by P-CVD remains amorphous with increasing RF power. The relaxation of Si atoms by means of chemical annealing of He metastable atoms gives rise to the formation of macrocrystalline structure at the high RF powers.

We studied the growth of polycrystalline silicon by using remote plasma chemical vapour deposition technique. The effects of RF power and the substrate temperature on the structural properties have been investigated. With increasing the RF power, the crystalline volume fraction and the grain size increase up to 100W, but decrease for the further increase in power level. We obtained the poly-Si with the crystalline volume fraction of about 74 at.% at the substrate temperature of 330°C.