The ion conductivities and phase transitions of lanthanum molybdate (La
2Mo
2O
9) substituted with lanthanide rare-earths are investigated using impedance spectroscopy, dilatometry, and X-ray powder ...diffraction. Among the substituted La
2Mo
2O
9 of 10
mol% Ce, Nd, Sm, Gd, Dy, Er, Yb, the specimens containing Er, and Dy exhibit depressed α–β phase transformation and high conductivities. Their 700
°C conductivities are approximately five to seven times that of La
2Mo
2O
9, around 0.26
S
cm
−1, comparable with those of (LaSr)(GaMg)O
3 and Gd-substituted CeO
2. Among the three compositions of 10
mol% Gd, Dy, Er showing depressed phase transition, Er- and Dy-substituted La
2Mo
2O
9 possess relatively low thermal expansion coefficient 11×10
−6
K
−1, compared with that of the Gd-substituted La
2Mo
2O
9, 18×10
−6
K
−1, which is near that of La
2Mo
2O
9. Hence, Dy and Er are valuable dopants in improving the La
2Mo
2O
9 properties. Across the lanthanide series, 10
mol%-substituted La
2Mo
2O
9 demonstrates systematic variations in the conductivity–temperature relation. Hysteresis phenomena in both of conductivity and thermal expansion are also observed in those compositions which display phase transition.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
X-ray reflectivity and grazing incidence X-ray diffraction (XRD) measurements were performed to characterize the microstructure of homoepitaxial SrTiO
3 (STO) films grown by radio-frequency (RF) ...magnetron sputtering technique. Interference fringes in two sets of disparate period were observed from the reflectivity curves; the fitted result indicates that, in addition to the normal STO layer, there exists a transition layer, which has a smaller mass density than that of STO. X-ray scattering results reveal that an STO film deposited at low temperature (
T≦300 °C) has a density about 10–12% less than that of bulk STO and shows a poor epitaxial relation with the substrate. The presence of oscillation fringes in the diffuse scattering indicates that a conformal relationship exists between the layer and the substrate from deposition at high temperature. The appearance of interference fringes of the crystal truncation rod observed for a film grown at high temperature clearly demonstrates a well epitaxial relationship between the film and the substrate.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
High-quality heteroepitaxial LaNiO
3 (LNO) thin films were successfully grown on SrTiO
3 (STO) substrates with RF-magnetron sputtering deposition at substrate temperatures in a range 150–650
°C. ...Azimuthal scans around the surface Bragg peak of the film and lattice images from a high-resolution transmission electron microscope (HRTEM) show that a well epitaxial relationship between film and substrate is achievable through RF sputtering growth. BaTiO
3/SrTiO
3 (BTO/STO) artificial superlattices subsequently deposited on LNO-coated STO substrates with RF sputtering were found also to have a large dielectric constant and a small dissipation factor.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Peroxisome proliferator-activated receptor gamma (PPARgamma) is well-known as the receptor of thiazolidinedione antidiabetic drugs. In this paper, we present a successful example of employing ...structure-based virtual screening, a method that combines shape-based database search with a docking study and analogue search, to discover a novel family of PPARgamma agonists based upon pyrazol-5-ylbenzenesulfonamide. Two analogues in the family show high affinity for, and specificity to, PPARgamma and act as partial agonists. They also demonstrate glucose-lowering efficacy in vivo. A structural biology study reveals that they both adopt a distinct binding mode and have no H-bonding interactions with PPARgamma. The absence of H-bonding interaction with the protein provides an explanation why both function as partial agonists since most full agonists form conserved H-bonds with the activation function helix (AF-2 helix) which, in turn, enhances the recruitment of coactivators. Moreover, the structural biology and computer docking studies reveal the specificity of the compounds for PPARgamma could be due to the restricted access to the binding pocket of other PPAR subtypes, i.e., PPARalpha and PPARdelta, and steric hindrance upon the ligand binding.
Therapeutic angiogenesis is essential for rescuing necrotic tissues in cases of ischemic disease. The exogenous hydrogen sulfide (H
S) donor, diallyl trisulfide (DATS), has been investigated as a ...therapeutic agent that promotes angiogenesis. However, the short half-life of generated H
S limits its therapeutic efficacy. In an attempt to overcome this difficulty, a poly(D,L-lactic-co-glycolic acid) microparticle system that contains DATS (DATS@MPs) is prepared as an in situ depot for the controlled release of H
S, providing slow release and long-term effectiveness. The results of in vitro investigations indicate that the slow-released DATS from the DATS@MPs depot yields a longer intracellular production of H
S than that from a free DATS depot. The intracellular generation of H
S favors the translocation of the transcription factor, Nrf2, from the cytosol to nuclei, potentially upregulating the gene expressions of antioxidant enzymes, ultimately increasing cellular resistance to oxidative stress. Intramuscular injection of the slow-releasing H
S donor depot DATS@MPs in an ischemic limb that is experimentally generated in a mouse model promotes therapeutic angiogenesis and protects cells from apoptosis and tissues from necrosis, ultimately salvaging the limb. These analytical results reveal that DATS@MPs is potentially useful in H
S-based therapy for treating ischemic diseases.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The crossbar structure of resistive random access memory (RRAM) is the most promising technology for the development of ultra-high-density devices for future nonvolatile memory. However, only a few ...studies have focused on the switching phenomenon of crossbar RRAM in detail. The main purpose of this study is to understand the formation and disruption of the conductive filament occurring at the crossbar center by real-time transmission electron microscope (TEM) observation. Core-shell Ni/NiO nanowires were utilized to form a cross structure, which restricted the position of the conductive filament to the cross-center. A significant morphological change could be observed near the crossbar center, which resulted from the out-diffusion and backfill of oxygen ions. Energy dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS) demonstrated that the movement of the oxygen ions led to the evolution of the conductive filament, followed by redox reactions. Moreover, the distinct reliability of the crossbar device was measured via ex situ experiments. In this work, the switching mechanism of the crossbar core-shell nanowire structure is beneficial to overcome the problem of nanoscale minimization. The experimental method shows high potential to fabricate high-density RRAM devices, which could be applied to 3D stacked package technology and neuromorphic computing systems.
Figure 1
There are no complete records on the prevalence of childhood skin diseases in Taiwan. We conducted a survey of infectious skin diseases and skin infestations among primary school children in Taitung ...County, which is located in southeastern Taiwan.
From March 1998 through October 1998, a total of 3,029 students from four rural districts (Changbin, Yanping, Lanyu, and Dawu) and one urban area (Taitung City of Taitung County) were examined by dermatologists. Treatment and instructions for disease care were given immediately after the diagnosis of dermatoses, when appropriate.
The most common infectious skin diseases and infestations were pediculosis capitis (12.9%), verruca vulgaris (5.1%), tinea versicolor (4.4%), tinea pedis (4.1%), verruca plantaris (1.8%), and scabies (1.4%). Most skin diseases, including pediculosis capitis, scabies, verruca vulgaris, verruca plantaris, folliculitis, pyoderma, tinea pedis, and tinea versicolor, were significantly more common in rural areas than in the urban area (p < 0.05 for all). Pediculosis capitis was more common among girls (p < 0.001), but tinea pedis and tinea versicolor were more common among boys (p < 0.05).
The prevalence of most skin infections and infestations are much higher in rural Taitung County than in Taitung City. Prevention and treatment of these skin diseases should be reemphasized in the education of teachers, as well as students and their families. Adequate dermatologic training of nurses and physicians and the development of teleconsultation and teledermatology in rural areas might decrease the prevalence of these skin diseases in school children.
