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A new method, called the “thermal-shock method”, was introduced for the production of high-quality BaMgAl10O17:Eu (BAM) phosphor powder. A conventional solid-state process assisted by a thermal shock at 950 °C results in a pure BAM phase with no impurities such as BaAl2O4, MgAl2O4, or EuAlO3. When both AlF3 and H3BO3 are simultaneously used as the flux, this simple thermal-shock reaction yields the phosphor particles with highly improved morphology. Excellent emission intensity higher than that of commercial phosphor can be obtained after reduction at 1000 °C. Compared with other alternative liquid solution techniques, no use of any liquid medium that is harmful to the environment is one of advantages of the thermal-shock method for practical purposes. This synthetic process would be of great interest to the low-cost industrial production of high-performance BAM phosphor.

Li-doped Y2O3:Eu3+ luminescent thin films have been grown on Si (100) and Al2O3 (0001) substrates using a pulsed laser deposition technique. The thin film phosphors were deposited by changing the substrates and the processing conditions (substrate temperature and oxygen pressure). The films grown under different deposition conditions have been characterized using microstructural and luminescent measurements. The PL intensity of the Li-doped Y2O3:Eu3+ films are highly dependent on the crystallinity and surface roughness of the films. The films are uniaxially textured in both Si (100) and Al2O3 (0001) cases and the films grown on Al2O3 (0001) substrate exhibit the superior crystallization and photoluminescent properties. The brightness of the films grown on Al2O3 (0001) substrate was increased by a factor of 2.1 in comparison with that of the films grown on Si (100) substrate. The photoluminescence intensity and surface roughness have similar behavior as a function of not only oxygen pressure but also substrate temperature. This phosphor may promise for application to the flat panel displays.

Tetragonal K 2 NiF 4 -type La 2 - 2 x Sr 2 x Cu 1 - x Fe x O 4 - y solid-solution have been synthesized by citrate based sol-gel method. The valence state of iron was determined by Mossbauer spectroscopy and subsequent iodometric titration clearly showed that the copper ions in this solid-solution are in the mixed valence state Cu(II/III). When x ≤ 0.3, Fe(III) is competing with the mixture of Cu(II) and Cu(III) and La 2 - 2 x Sr 2 x Cu 1 - x Fe x O 4 - y exhibits a metallic character. No evidence for Cu(II)-O-Fe(IV) ↔ Cu(III)-O-Fe(III) valence degeneracy was observed. In contrast, a small amount of Fe(IV) is observed with increasing x (x=0.4 and 0.5), revealing a semiconducting behavior. These results suggest that the electronic interaction of Cu(III)-O-Fe(III) contributes greatly to the metallic character, while the electronic interaction of Cu(II)-O-Fe(IV) deteriorates the metallic character of La 2 - 2 x Sr 2 x Cu 1 - x Fe x O 4 - y .

We have deposited Fe 3− x Co x O 4 films on glass substrates from aqueous solutions of CoCl 2 , FeCl 2 and NaNO 2 using the thin-liquid film method. X-ray diffraction patterns of the films show that the relative intensity of (1 1 1) to (3 1 1) reflection increases by the addition of Co 2+ from less than 10% for Fe 3 O 4 ( x =0) to 145% for Fe 2.59 Co 0.41 O 4 . The maximum coercive force ( H c =2110 Oe), which was measured by a vibrating sample magnetometer, is also obtained for the Fe 2.59 Co 0.41 O 4 film. Mossbauer analysis shows that the Co 2+ is located at the octahedral (O h ) site of the inverse spinel and the presence of Co 2+ enhances the perpendicular magnetic anisotropy. The electrical resistivity of the films was changed from about 1 to 10 6 Ω cm by the addition of Co 2+ at room temperature. We suggest that the formation of Co 2+ ion pairs and the excess octahedral stabilization energy of Co 2+ ions in the Fe 3− x Co x O 4 are partly the reasons of the anisotropy.

Carbon nanotubes (CNTs) could be formed on Si substrate using nickel catalyst under microwave plasma-enhanced chemical vapor deposition system. Under the high, negative-bias voltage (−400 V) condition, we found the formation of the carbon nanotube islands and the bamboo-like carbon nanotube interconnection lines. Most of the bamboo-like carbon nanotubes connected with the carbon nanotubes themselves, which indicates the self-assembled characteristics of the carbon nanotube interconnection lines. The self-assembled characteristics of the bamboo-like carbon nanotube interconnection lines were evaluated using computer-aided image analysis.

compounds were prepared using a conventional solid state reaction. Based on the Rietveld refinements of X-ray diffraction results, it is revealed that compounds are the single phases with K2NiF4 type tetragonal system in the range of 0=x=0.3, while the mixed phases of and in the range of . By means of X-ray photoelectron spectroscopy, the valence states of Ru and Cu in , have been confirmed to 4+ and 2+, respectively. The bond length difference between octahedron is gradually decreased with increasing Cu content in , which results in the lower c/a ratio. So, it might be assured that the variation of local symmetry of octahedron is very closely related to the transporting property of compounds. The behavior of resistivity discloses that the metallic property in changes into the semiconducting one in proportion to the Cu content in .

The SrRu 1− x Fe x O 3 films ( x =0.0, 0.1, 0.3, 0.5) were successfully fabricated using the powders coated with SiO 2 nano-particles (≈30 nm). The SrRu 1− x Fe x O 3 powders (≈500 nm) were synthesized by a conventional solid-state reaction. Thanks to the fused SiO 2 nano-particles in the vicinity of the glass softening temperature at approximately 700 °C, the SrRu 1− x Fe x O 3 powders are strongly attached onto the surface of the glass substrate. The various techniques were performed to characterize the films, such as X-ray photoelectron spectroscopy, field emission-scanning electron microscopy, Mossbauer spectroscopy and resistivity measurements. This simple and low-cost method to get the SrRu 1− x Fe x O 3 films ( x =0.0, 0.1, 0.3, 0.5) may promise for applications to microelectronics field, such as dynamic random access memory or ferro-electric random access memory.

Cathodoluminescent (CL) spectra of Li-doped Gd 2− x Y x O 3 :Eu 3+ solid-solution (0.0⩽ x ⩽0.8) were investigated at low voltages (300 V–1 kV). The CL intensity is maximum for the composition of x =0.2 and gradually reduces with increasing the amount of substituted Y content. In particular, small (∼100 nm) particles of Li-doped Gd 1.8 Y 0.2 O 3 :Eu 3+ are obtained by firing the citrate precursors at only 650°C for 18 h. Relative red-emission intensity at 300 V of this phosphor is close to 180% in comparison with that of commercial red phosphor Y 2 O 3 :Eu 3+ . An increase of firing temperature to 900°C results in 400–600 nm sized spherical particles. At low voltages (300–800 V), the CL emission of 100 nm sized particles is much stronger than that of 400–600 nm sized ones. In contrast, the larger particles exhibit the higher CL emission intensity at high voltages (1–10 kV). Taking into consideration small spherical morphology and effective CL emission, Li-doped Gd 1.8 Y 0.2 O 3 :Eu 3+ appears to be an efficient phosphor material for low voltage field emission display.

The enhancement of structural anisotropy and magnetic anisotropy in ferrite films, Fe3−xMxO4 (M = Fe, Co, Mn), which were deposited on glass substrates from aqueous solutions by thin liquid film (TLF) method at a low temperature (358 K), was compared in x-ray diffraction, conversion electron Mossbauer spectroscopy, and vibrating sample magnetometer measurements. The experimental results showed that the highly coercive Fe3−xCoxO4 films, maximum coercivity of 0.21 T at room temperature, have a preferential growing direction along the magnetic easy axis of the magnetite, 111. While anisotropy was enhanced by the addition of Co2+ ions in the reaction solution, no enhancement was observed in the TLF-films of Fe3O4 and Fe3−xMnxO4. The enhanced anisotropy is probably caused by the extra stabilization energy of the Co2+ ions in the octahedral sites of the spinel and the interactions between the Co2+ ions in the spinel. The alternating deposition of metal ions and oxide ions in TLF process, which is a simulation of the atomic layer deposition, may help the alignment. The most anisotropic TLF film was Fe2.59Co0.41O4.

Y2O3:Eu3+ and Li-doped Y2O3:Eu3+ luminescent thin films have been grown on sapphire substrates using a pulsed laser deposition technique. The thin-film phosphors were deposited at a substrate temperature of 600°C under the oxygen pressures of 100, 200, and 300 mTorr. The films grown under different deposition conditions have been characterized using microstructural and luminescence measurements. The crystallinity and photoluminescence (PL) of the films are highly dependent on the oxygen pressure. The PL brightness data obtained from Y2O3:Eu3+ films grown under optimized conditions have indicated that sapphire is a promising substrate for the growth of high-quality Y2O3:Eu3+ thin-film red phosphor. In particular, the incorporation of Li+ ions into Y2O3 lattice could induce a remarkable increase of PL. The highest emission intensity was observed with LiF-doped Y1.84Li0.08Eu0.08O3 (Y2O3LiEu), whose brightness was increased by a factor of 2.7 in comparison with that of Y2O3:Eu3+ films. This phosphor may hold promise for application in flat-panel displays.

New layered oxides MII0.5LaTiO4 (M = Co, Cu, and Zn) were synthesized via the ion-exchange reaction of parent NaLaTiO4 in molten salts at 300−450 °C. Eutectic-like mixtures of MCl2 (M = Co and Cu) and KCl were required for the 1:2 exchange reaction of divalent cobalt and copper ions for monovalent sodium ion at low temperature. The structures of these phases were determined by Rietveld refinement of the powder X-ray and neutron diffraction data. The bright violet (M = Co), bright brown (M = Cu), and white (M = Zn) compounds crystallize in the tetragonal structure (space group P4/nmm) with cell constants a = 3.71379(6), 3.73606(9), and 3.7234(1) A and c = 12.7016(2), 12.0736(3), and 12.7488(6) A, respectively. Similarly to the structure of parent NaLaTiO4, a strongly distorted coordination environment for the Ti atom is revealed. In contrast, the transition metal atoms statistically occupy one-half of the distorted tetrahedral sites rather than the nine-coordinated sites in the interlayer spaces. Successfu...

The influence of Li doping on the crystallization behavior, morphology, and enhancement in photoemission intensity of Gd 2-x Y x O 3 :Eu 3+ solid-solution was investigated. To maximize an effect of the Li component which is volatile at elevated temperature, the citrate route was adopted for the synthesis at low temperature (650-850 °C). Firing the metal citrate precursor at 650 °C for 5 h was sufficient for the formation of 100 nm sized, nonaggregated, and spherical Li-doped Gd 2-x Y x O 3 :Eu 3+ particles, whose photoluminescence (PL) emission intensity is comparable with that of commercial red phosphor Y 2 O 3 :Eu 3+ . Such a temperature is much lower than the typical solid-state reaction or spray pyrolysis temperature (>1400 °C). Additional heat treatment up to 850 °C resulted in well-developed 500 nm sized pseudospherical particles whose PL brightness is close to ∼150% in comparison with that of commercial red phosphor. Li-doped Gd 2-x Y x O 3 :Eu 3+ appears to be a very promising red phosphor because the particle size and shape can be controlled at low temperature (650-850 °C) by the change of Y or Li contents without significant loss of brightness.

Purpose Following tooth extraction, alveolar ridge preservation (ARP) can maintain the dimensions of ridge height and width. Although previous studies have demonstrated the effects of ARP, few if any studies have investigated the compressive force applied during grafting. The aim of this study was to determine the effects of different compressive forces on the graft materials during ARP. Methods After tooth extraction, sockets were filled with deproteinized bovine bone mineral with 10% porcine collagen and covered by a resorbable collagen membrane in a double-layered fashion. The graft materials were compressed using a force of 5 N in the test group (n=12) and a force of 30 N in the control group (n=12). A hidden X suture was performed to secure the graft without primary closure. Cone-beam computed tomography (CBCT) was performed immediately after grafting and 4 months later, just before implant surgery. Tissue samples were retrieved using a trephine bur from the grafted sites during implant surgery for histologic and histomorphometric evaluations. Periotest values (PTVs) were measured to assess the initial stability of the dental implants. Results Four patients dropped out from the control group and 20 patients finished the study. Both groups healed without any complications. The CBCT measurements showed that the ridge volume was comparably preserved vertically and horizontally in both groups (P>0.05). Histomorphometric analysis demonstrated that the ratio of new bone formation was significantly greater in the test group (P0.05). Conclusions The application of a greater compressive force on biomaterials during ARP significantly enhanced new bone formation while preserving the horizontal and vertical dimensions of the alveolar ridge. Further studies are required to identity the optimal compressive force for ARP., Graphical Abstract

E-mail: parkjc@silla.ac.krReceived June 13, 2011, Accepted August 19, 2011Key Words : Recovery, Indium, ITO-scrap, Hydrothermal reaction, Alkaline solutionIndium element is very rare one and tend to occur at lowconcentrations in sulfide minerals rather than as oxides.Indium (0.21 ppm) is similar in abundance to Sb and Cd,whereas Tl (0.7 ppm) is close to Tm and somewhat lessabundant than Mo, W, and Tb (1.2 ppm). Indium, like Ga, isnormally recovered by electrolysis after prior concentrationin processes leading primarily to other elements (Pb/Zn).Indium metal is soft, silvery one with a brilliant lustre, andused to protect bearings against wear and corrosion. Indiummetal frequently uses in low-melting alloys and in electronicdevices as its low melting-point ( ≈ 156

Novel blue-emitting LaOBr:Eu(2+) and LaOI:Eu(2+) phosphors have been successfully synthesized and compared to LaOCl:Eu(2+). The emission spectra of LaOX:Eu(2+) (X = Cl, Br, and I) show that the peak maxima change somewhat to the red-shift region; 425 nm for LaOCl:Eu(2+), 427 nm for LaOBr:Eu(2+), and 431 nm for LaOI:Eu(2+), which is quite opposite to one based on spectrochemical series (I(-)Br(-)Cl(-)). From diffuse reflectance spectra, the band gap energies for LaOCl, LaOBr, and LaOI host lattice are estimated as 5.53 eV (44,594 cm(-1)), 5.35 eV (43,142 cm(-1)), and 4.82 eV (38,868 cm(-1)), respectively, using the Kubelka-Munk function. For LaOX host lattices, the band gap energies are gradually decreased going from Cl to I as the order of energy levels of np orbitals is Cl 3pBr 4pI 5p. A quantum wave function calculation from crystal field theory (CFT) indicates the same tendency with experimental data in the LaOX:Eu(2+) (X = Cl, Br, and I) phosphor materials. With considerations of the radial wave function shape, crystral structure differences and electronegativities among phosphor materials, the splitting energies of 5d orbitals are calculaed; ΔECl = 14,597 cm(-1), ΔEBr = 14,864 cm(-1), ΔEI = 15,001 cm(-1) for LaOX:Eu(2+) (X = Cl, Br, and I). It is noteworthy that the crystal field strength decreases when the interatomic distance decreases, which is probably dependent on the ionic radius of halide ions in the series of LaOX:Eu(2+) phosphor materials.

The aim of this study was to evaluate HA coated with different ratios of TCP as a carrier for hABMSCs obtained during implant osteotomy in comparison to slowly-resorbing biomaterial, Bio-Oss, as a negative control, using in vitro and in vivo experiments.Human ABMSCs (hABMSCs) harvested during implant osteotomy were transplanted using HA/TCP or Bio-Oss as carriers in a murine ectopic transplantation model (n = 12). Pore size and cell affinity were evaluated in vitro. The area of newly formed bone was analyzed histometrically, the number of osteocytes was counted, and immunohistochemical staining was conducted against several markers of osteogenesis, including alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX-2), osteocalcin (OCN), and osteopontin (OPN). Osteoclast formation was evaluated by tartrate-resistant acid phosphatase staining.The carrier materials had comparable pore sizes. The cell affinity assay resulted in a high proportion of cell adhesion (90%) in all experimental groups. Substantial new bone and osteocyte formation was observed on both HA/TCP carriers, whereas it was minimal with Bio-Oss. Positive immunostaining for ALP, RUNX-2, OCN, and OPN was observed with HA/TCP, but only limited expression of osteogenic markers with Bio-Oss. Conversely, there was a minimal osteoclast presence with Bio-Oss, but a significant presence of osteoclasts with both HA/TCP carriers.Both types of scaffolds, BCP and Bio-Oss, showed high stem cell-carrying potential, but the in vivo healing patterns of their complexes with hABMSC could be affected by the microenvironment on the surfaces of the scaffolds.

Purpose The preferred material for bone augmentation beyond the envelope of skeletal bone is the bone block graft, due to its dimensional stability. We evaluated the necessity of rigid fixation for the bone block graft, and compared the bone regeneration and volume maintenance associated with grafting using a synthetic hydroxyapatite block (HAB) and an autogenous bone block (ABB) without rigid fixation on rabbit calvaria over two different periods. Methods Cylinder-shaped synthetic HAB and ABB were positioned without fixation on the rabbit calvarium (n=16). The animals were sacrificed at 4 or 8 weeks postoperatively, and the grafted materials were analyzed at each healing period using microcomputed tomography and histologic evaluation. Results Integration of the graft and the recipient bed was observed in all specimens, although minor dislocation of the graft materials from the original position was evident in some specimens (six ABB and ten HAB samples). A tendency toward progressive bone resorption was observed in the grafted ABB but not in the grafted HAB, which maintained an intact appearance. In the HAB group, the area of new bone increased between 4 and 8 weeks postoperatively, but the difference was not statistically significant. Conclusions The nonfixed HAB was successfully integrated into the recipient bed after both healing periods in the rabbit calvaria. In spite of limited bone formation activity in comparison to ABB, HAB may be a favorable substitute osteoconductive bone material. Graphical Abstract

Human bone marrow stem cells (hBMSCs) represent a promising regenerative material because of their mutipotency, including their ability to regenerate collagenous soft tissues. We previously found that water-soluble chitin (WSC) enhances the ability of human periodontal ligament stem cells (hPDLSCs) to synthesize collagen tissue. The aim of this study was to determine the effects of WSC on hBMSCs and hPDLSCs for the collagen synthesis both in vitro and in vivo. hBMSCs and hPDLSCs were isolated and expanded with or without 0.3 mg/mL WSC. A series of in vitro and in vivo analyses were performed to evaluate their characteristics as stem cell populations. Then, collagen and hydroxyproline assays were conducted using both in vitro and in vivo assay models, and the real-time polymerase chain reaction was performed to analyze the expression of collagen-related markers. WSC-treated and nontreated hBMSCs and hPDLSCs were transplanted into immunocompromised mice, and histology and immunohistochemistry analyses were conducted after 8 weeks. The in vitro results showed that those cells possessed the characteristics of mesenchymal stem cells. The amount of soluble collagen synthesized was significantly greater in WSC-treated hBMSCs than in the nontreated group; conversely, treatment of hPDLSCs with WSC decreased the formation of soluble collagen. The amount of insoluble collagen synthesized was greater in the WSC-treated groups than in the nontreated groups for both hBMSCs and hPDLSCs. The hydroxyproline contents of the regenerated soluble and insoluble collagens were similar. The expressions of mRNA for collagen types I-V, hyaluronic acid synthase 1 (HAS1), HAS2, and HAS3, and the LOX family were higher in WSC-treated hPDLSCs than in the nontreated group, whereas WSC increased the expression of collagen type III and decreased that of collagen type I in hBMSCs. The histology and immunohistochemistry results revealed that WSC significantly increased the amount of collagen formed in vivo by both types of stem cells. Collectively, treatment with WSC significantly enhanced the collagen-forming potentials of hBMSCs and hPDLSCs, but the collagen they produced exhibited distinctively different characteristics. These findings suggest that the appropriate stem-cell source should be chosen based on the purpose of the required regenerated tissue.

The aims of this study are to determine whether the antigen-inexperienced (naive, CD45RB high-density) T-cell (CD4(+)CD45RB(High) T-cell) transfer model is associated with alveolar bone resorption, to elucidate the local osteogenic/adipogenic potential of alveolar bone marrow stromal cells (ABCs) from T-cell-transferred animals, and to investigate the systemic osteogenic potential by transplanting human periodontal ligament stem cells (hPDLSCs) into these animals.CD4(+)CD45RB(High) and CD4(+)CD45RB(Low) (antigen-experienced [memory, CD45RB low-density]) T cells were sorted and transferred into severe combined immunodeficiency (SCID) mice to induce inflammatory bowel disease-like syndrome (n = 8). hPDLSCs were transplanted into T-cell-transferred SCID mice to examine ectopic cementum formation 8 weeks after T-cell transfer. The mandibles and tibias of these mice were retrieved for microcomputed tomography (micro-CT), histomorphometric analysis, and isolation of ABCs 16 weeks after T-cell transfer. The in vitro osteogenic and adipogenic potentials of the ABCs were evaluated.Histologic and micro-CT analysis revealed that the transfer of CD4(+)CD45RB(High) T-cell subset was sufficient for alveolar bone resorption and affected the osteogenic/adipogenic potential of ABCs. Furthermore, it was found that CD4(+)CD45RB(High) T-cell-transferred animals have decreased systemic osteogenic potential, as evidenced using the in vivo ectopic hPDLSC transplantation model.CD4(+)CD45RB(High) T-cell transfer induced both alveolar bone resorption and reduced systemic osteogenic potential, with a concomitant downregulation of the osteogenic potential of ABCs.

The inductance of superconducting microstrip lines is measured both as a function of current and temperature. The measurements are performed at 10 MHz for both meander and straight lines by using a multi-frequency LCR meter. The normal state resistance is observed to follow a linear temperature dependence with a slope of 3.59/spl times/10/sup -3//K for the straight line and with a slope of 2.96/spl times/10/sup -3//K for the meander line. The change in inductance is well described by a quadratic dependence on temperature. This result is consistent with an unconventional pairing state. As for the dependence on the bias current, the inductance shows a squared dependence on the bias current. The results for the current- and temperature-controlled inductance are in good agreement with an equation derived using the Ginzburg-Landau theory for the case of thin films.

In sol-gel method using the citric acid, the citric acid molecule loses 3 protons from the three carboxyl groups, which results in the citrate anion. This citrate anions can chelate metal cations like as the interaction between citric acid and colloidal silica. This is the reason why we use colloidal silica solution instead of TEOS for the preparation of Zn

Li-doped Gd2O3:Eu3+ phosphor was developed by the conventional solid state and sol-gel methods. The effect of lithium concentration on the emission behavior of Gd2−x−yLixEuyO3−δ was investigated by photoluminescence and cathodoluminescence measurements. At 500 V, a cathodoluminescent efficiency of ∼180 % compared to that of commercial red-phosphor Y2O3:Eu3+, was observed with the nominal composition of (Gd1.84Li0.08Eu0.08)O3−δ. Such a brightness is the highest among the previously reported red-emission in the electron voltage range of 0.5 − 1 kV. This material would be a potential candidate for application in field emission display.

The catalysts manufacturing industry is the second largest consumer of PGMs after the jewelry industry. Automotive catalysts comprise refractory oxides support on which two or more precious metals (platinum, palladium, rhodium etc.) are dispersed in very low concentration (0.1-0.3 wt.% of the monolith). The honeycomb type monolith is typically made of a cordierite (2Al2O3·2MgO·5SiO2). 2 Several researchers have dealt with the recovery of these metals as the recovery of precious metals from spent automotive catalysts is of economical importance. 3-7 Spent autocatalysts are usually smelted in the presence of larger amounts of collector metals (Cu, Fe, Pb, Ni etc.) After leaching the precious metals enriched in the collector metals with acid, the precious metals can be selectively recovered. Among PGMs, rhodium (Rh) is an exceedingly rare element, comprising only 0.0001 PPM of the earth’s crust. 8 Moreover, rhodium is especially notable for its extreme inertness to acids, even aqua regia. Because of scarcity and high price, the recovery of rhodium from scrap is an important issue. Rhodium has a special catalytic activity to reduce nitrogen oxides (NOx) to N2, and is a main element as an autocatalyst. 9 Rhodium plated electrodes are used in the soda industry for electrolysis of salt water, and for electrodes for domestic water treatment. Rhodium plating is used widely in the jewelry industry. In the electronics industry, rhodium plating is used for electric contacts, e.g., ferreed switches. 10 The purification and recovery of rhodium from the other precious metals has always been difficult because of its complex aqueous chemistry in chloride solution as well as extreme inertness to acids, even aqua regia. It should be pointed out that the key factor for success in the separation of rhodium from the other precious metals is the developing an effective dissolution process for rhodium. It is well known that the disulfate melt technique on rhodium metal is utilized for quantitative dissolution of rhodium and its separation from iridium and platinum. 11 Another method has been developed for recovering PGMs from scrap with the propose of improving Rh dissolution in acid. Reactive metal vapours such as magnesium (Mg) and calcium (Ca) were reacted with powdered Rh in a closed stainless steel reaction vessel at a constant temperature ranging from 873 to 1173 K. 9 Iron(II) oxide with NaCl structure was successfully synthesized in a quartz tube sealed under vacuum. Hematite in an evacuated silica tube progressively loses oxide ions at 1373 K depending on the heating time. Finally, α-Fe2O3 is completely transformed into the well crystallized Fe0.935O after heat treatment at 1373 K for 84 h. 12 Silica tube is very suitable one for the chemical vapour transport reactions in an inert atmosphere because of hightemperature resistance, no-contaminants including foreign metals, and the ease of sealing under vacuum. In this work, the chemical vapour transport reactions between magnesium and rhodium are attempted using silica ampules sealed under vacuum. And also, the verifications, such as the formation and dissolution of intermetallic compounds (MgxRhy), purification and recovery of rhodium, are performed.

Three copper complex ions, [Cu(en) 2 ] 2+ , [Cu(cyclam)] 2+ , and [Cu(H 2 O) 4 ] 2+ are intercalated into a layered silicate, Hectorite (Hec), by ion exchange reaction According to the powder XRD analysis, the basal increments of 3.21 A for [Cu(en) 2 ] 2+ -Hec, 3.81 A for [Cu(cyclam)] 2+ -Hec, and 2.43 A for [Cu(H 2 O) 4 ] 2+ Hec indicate that the local geometry around copper (II) is square planar for all the intercalates. XANES results show the characteristic peak of square planar structure due to the ligand to metal charge transfer (LMCT) effect, which is shifted to lower energy side with an order of 0.5∼1.6eV but the main edges due to Is → 4p x and 1s → 4p σ transitions are shifted to higher energy side for about 0.5∼1.5eV compared to precursor depending on the ligands. From Cu K-edge EXAFS analysis, it is found that four nitrogen atoms at ∼2.0A and two oxygen atoms at ∼2.4A are coordinated with copper(II) in precursor salts, but only four nearest neighbors are coordinated to copper (II) at ∼2.0A in the intercalated complexes.

X-ray absorption spectroscopic studies at the Cu K-edge have been performed for [Cu(en)2]2+, [Cu(cyclam)]2+, and their intercalated forms of two-dimensional layer silicate to examine how the structural and electronic modifications influence the stabilization of copper complexes in the charged interlayer space. According to the EXAFS analysis, copper complex ions in the layer silicate are stabilized at the center of the siloxane ring, and negatively charged layers are likely to act as axial counteranions. It is spectroscopically confirmed that the covalent bonding character between copper and ligand is enhanced by the intercalation into the silicate layers, depending upon the kind of ligands. There is a good linear relationship between the shoulder peak position of Cu K-edge XANES spectra and d−d transition band position of UV−visible spectra, which means that the former reflects the ligand-to-metal charge transfer effect.

This paper investigates the relationship between US MNCs' valuations and anti-Americanism in countries where MNCs' foreign subsidiaries are located. We find that MNCs suffer value-destruction when they enter markets where people express severe anti-Americanism. However, we uncover that geographic diversification into these high anti-Americanism countries significantly increases firm value if the MNC has high levels of intangibles such as technological know-how and marketing expertise. Our findings are consistent with the notion that the advantages from internalizing the cross-border transfer of intangibles are greater when barriers to competition are higher.

Endoscopic submucosal desection (ESD) is an effective treatment for selected patients with early gastric cancer (EGC). The purpose of this study was to examine the short-term and long-term outcomes of ESD of undifferentiated early gastric cancer. Data for 1,241 patients who underwent ESD for treatment of EGC between February 2003 and May 2010 were collected. We performed a retrospective analysis of the medical records of 74 patients diagnosed with undifferentiated EGC. We divided the enrolled cases into two groups: the expanded-criteria group (EC group) versus the non-EC group, according to lesion size, presence of ulceration, and pathologic review. Of a total of 74 lesions with undifferentiated EGC, as a result of pathologic examination the EC group included 29 cases and the non-EC group included 45 cases. The mean diameter of lesions was 19.86 ± 12.5 mm. The overall rates of en bloc resection and complete resection were 90.5 % (67/74) and 73 % (54/74), respectively. The curative resection rate was low at 31.1 %. If limited to the pathologically diagnosed EC group, the curative resection rate was 79.3 % (23/29). During median follow-up periods of 34 months (range 7–81), local recurrences were observed in 5.5 % (4/74) of patients. All of these were in the non-EC group and all underwent noncurative resection. There was no mortality related to ESD for treatment of EGC during follow-up. ESD may be a feasible treatment for selected patients with undifferentiated EGC; this should be validated by development of new criteria for ESD for treatment of EGC.

Purpose Endoscopic submucosal dissection has recently been practiced on a differentiated type of early gastric cancer. However, there is no clear evidence for endoscopic treatments of signet ring cell carcinoma. The aim of this study is to identify the predictive clinicopathological factors for lymph node metastasis in signet ring cell carcinoma for assisting endoscopic submucosal dissection trials. Materials and Methods A total of 186 patients with early signet ring cell carcinoma who underwent radical curative gastrectomy between January 2001 and September 2009 were enrolled in this study. Retrospective reviews of their medical records are being conducted. Several clinicopathologic factors were being investigated in order to identify predictive factors for lymph nodes metastasis: age, gender, tumor size, type of operation, tumor location, gross type, ulceration, Lauren's classification, depth of invasion, and lymphatic invasion. Results The lymph node metastasis rate for signet ring cell carcinoma was 4.3% (n=8). Of the 186 lesions with early signet ring cell carcinoma, 91 (48.9%) tumors were larger than 15 mm in size and 40 (21.5%) showed submucosal invasions in the resection specimens. In multivariate analysis, only the lymphatic invasion (P

Gd2O3:Eu3+ and Li-doped Gd2O3:Eu3+ luminescent thin films have been grown on Al2O3 (0001) substrates using pulsed-laser deposition. The films grown under different deposition conditions show different microstructural and luminescent characteristics. Both cubic and monoclinic crystalline structures were observed in Gd2O3:Eu3+ films, but only the cubic crystalline structure was observed for Li-doped Gd2O3:Eu3+ films grown under certain condition. The photoluminescence (PL) brightness data obtained from Li-doped Gd2O3:Eu3+ films indicate that sapphire is a promising substrate for growth of high-quality Li-doped Gd2O3:Eu3+ thin-film red phosphor. In particular, incorporation of Li+ ions into the Gd2O3 lattice can induce a remarkable increase of PL. The highest emission intensity was observed with LiF-doped Gd1.84Li0.08Eu0.08O3, whose brightness was a factor of 2.3 larger than that from Gd2O3:Eu3+ films. This phosphor is promising for applications in flat-panel displays.

Gd-substituted Y2−xGdxO3:Eu3+ luminescent thin films have been grown on Al2O3 (0001) substrates using pulsed-laser deposition. The films grown under different deposition conditions have been characterized using microstructural and luminescent measurements. The crystallinity, surface morphology, and photoluminescence (PL) of the films are highly dependent on the amount of Gd. The PL brightness data obtained from Y2−xGdxO3:Eu3+ films grown under optimized conditions have indicated that the PL brightness is more dependent on the surface roughness than on the crystallinity of the films. In particular, the incorporation of Gd into Y2O3 lattice could induce a remarkable increase of PL. The highest emission intensity was observed with Y1.35Gd0.60Eu0.05O3, thin film whose brightness was increased by a factor of 3.1 in comparison with that of Y2O3:Eu3+ films. This phosphor has promise for application to the flat panel displays.

Objective The purpose of this study was to determine the effectiveness of adjunctive application of locally delivered minocycline ointment associated with flap surgery for the treatment of patients with chronic severe periodontitis. Material and Methods Twenty patients with chronic severe periodontitis were treated in a split-mouth study to either adjunctive application of locally delivered minocycline ointment in association with flap surgery (FM) or flap surgery only (FO); additional minocycline application was performed at 3 months post operation. Clinical evaluation of the plaque index, probing depth (PD), bleeding on probing (BOP), gingival recession, and clinical attachment level (CAL) was conducted at baseline and at 3 and 6 months after treatment. Results Clinical evaluations revealed that although both sites exhibited clinical improvement, there was a statistically significant reduction in PD (3.34 ± 0.03 mm) and BOP (78.01 ± 11.42%), and a significant gain of CAL (1.88 ± 0.21 mm) at the FM site compared with the FO site (reduction of PD and BOP: 2.62 ± 0.06 mm, 50.33 ± 15.01%, and gain of CAL: 1.55 ± 0.13 mm) at 6 months post operation (p

Purpose The osseointegration around titanium mini-implants installed in macroporous biphasic calcium phosphate (MBCP) blocks was evaluated after incubation with recombinant human bone morphogenetic protein-2 (rhBMP-2) in an ectopic subcutaneous rat model. Methods Mini-implants (φ1.8×12 mm) were installed in MBCP blocks (bMBCPs, 4×5×15 mm) loaded with rhBMP-2 at 0.1 mg/mL, and then implanted for 8 weeks into subcutaneous pockets of male Sprague-Dawley rats (n=10). A histomorphometric analysis was performed, and the bone-to-implant contact (BIC) and bone density were evaluated. Results Significant osteoinductive activity was induced in the rhBMP-2/bMBCP group. The percentage of BIC was 41.23±4.13% (mean±standard deviation), while bone density was 33.47±5.73%. In contrast, no bone formation was observed in the bMBCP only group. Conclusions This model represents a more standardized tool for analyzing osseointegration and bone healing along the implant surface and in bMBCPs that excludes various healing factors derived from selected animals and defect models.

The aim of this study was to evaluate long-term (24 weeks) alveolar bone maturation following surgical application of recombinant human growth/differentiation factor-5 (rhGDF-5) in an injectable poly-lactide-co-glycolide-acid (PLGA) composite carrier using an established periodontal defect model.Routine, bilateral, 4 × 5 mm (width × depth), 1-wall, critical-size, intra-bony periodontal defects were surgically created at the 2nd and 4th mandibular premolar teeth in 10 Beagle dogs. The animals were randomized to receive (split-mouth design; defect sites in the same jaw quadrant getting the same treatment) rhGDF-5/PLGA high dose (188 μg/defect) versus sham-surgery control (5 animals), and rhGDF-5/PLGA low dose (37 μg/defect) versus carrier control (5 animals). The animals were euthanized for histometric analysis following a 24-week healing interval.Clinical healing was uneventful. The rhGDF-5 high dose significantly increased bone formation compared with controls in terms of bone area (p0.05), and a high degree of bone maturation was observed in the rhGDF-5/PLGA high dose group. Root resorption/ankylosis or other aberrant healing events were not observed.The rhGDF-5/PLGA appears to support alveolar bone healing/regeneration and the rhGDF-5/PLGA high dose uniquely increased maturation of the regenerated bone.

Purpose: The use of appropriate instruments to clean surfaces with minimal change, is critical for the successful maintenance of a dental implant. However, there is no consensus about the type and methodology for such instruments. The aim of this study was to characterize changes in the roughness of titanium surfaces treated by various scaling instruments. Methods: Thirty-seven identical disks (5 mm in diameter) were investigated in this study. The specimens were divided into eight groups according to the types of instrumentation and the angle of application. Ultrasonic scaling systems were applied on a titanium disk to simulate standard clinical conditions. The equipment included a piezoelectric ultrasonic scaler with a newly developed metallic tip (NS group), a piezoelectric ultrasonic scaler with a conventional tip (CS group), a piezoelectric root planer ultrasonic scaler with a conventional tip (PR group), and a plastic hand curette (PH group). In addition, the sites treated using piezoelectric ultrasonic scaler systems were divided two sub-groups: 15 and 45 degrees. The treated titanium surfaces were observed by scanning electron microscopy (SEM), and the average surface roughness (Ra) and mean roughness profile depth (Rz) were measured with a profilometer. Results: SEM no significant changes in the titanium surfaces in the NS group, regardless of the angle of application. The PH group also showed no marked changes to the titanium surface, although some smoothening was observed. All CS and PR sites lost their original texture and showed irregular surfaces in SEM analysis. The profilometer analysis demonstrated that the roughness values (Ra and Rz) of the titanium surfaces increased in all, except the PH and NS groups, which showed roughness decreases relative to the untreated control group. The Ra value differed significantly between the NS and PR groups (P < 0.05). Conclusions: The results of this study indicated that changes in or damage to titanium surfaces might be more affected by the hardness of the scaler tip than by the application method. Within the limitations of this study, the newly developed metallic scaler tip might be especially suitable for peri-implant surface decontamination, due to its limited effects on the titanium surface.

We investigate whether diversity in points of view within corporate boards, as captured by the diversity in political ideology of board members, can affect a firm's performance. We employ personal political contributions' data to measure political ideology distance among groups of inside, outside directors and the CEO. Our empirical evidence strongly supports the notion that outside directors' monitoring effectiveness is more likely to be enhanced when their viewpoints are distinct from those of management. We find that ideologically diverse boards are associated with better firm performance, lower agency costs and less insiders' discretionary power over the firm's Political Action Committee (PAC) spending. Taken together, our results lead us to conclude that multiplicity of standpoints in corporate boardrooms is imperative for board effectiveness.

Carbon coils could be synthesized using C2H2/H2 as source gases and SF6 as an incorporated additive gas under thermal chemical vapor deposition system. Nickel catalyst layer deposition and then hydrogen plasma pretreatment were performed prior to the carbon coils deposition reaction. To obtain the geometrically controlled carbon coils, the cycling on/off modulation process for C2H2/SF6 flows was introduced during the initial reaction. According to the different reaction processes, the different cycling on/off ratio and the different cycling numbers for C2H2/SF6 flows were carried out. The characteristics (formation density, morphology, and geometry) of the deposited carbon coils on the substrate were investigated. Microsized coils as well as nanosized coils could be existed under the higher growing/etching time ratio (180/30 s) condition. On the other hand, the formation of nanosized coils could be mainly observed under the lower growing/etching time ratio (30/180 s) condition. With increasing the numbers of cycles, the diameters of carbon nanofilaments composed the coils decreased. The enhanced etching ability by the fluorine species was considered the main cause to control the geometry of carbon coils according to the growing/etching time ratio of the cycling on/off modulation process for C2H2/SF6 flows.

Y2O3:Eu3+ and Li-doped Y2O3:Eu3+ luminescent thin films have been grown on sapphire substrates using pulsed-laser deposition. The films grown under different deposition conditions have been characterized using microstructural and luminescent measurements. The photoluminescence (PL) brightness data obtained from Li-doped Y2O3:Eu3+ films grown under optimized conditions have indicated that sapphire is a promising substrate for the growth of high-quality Li-doped Y2O3:Eu3+ thin-film red phosphor. In particular, the incorporation of Li+ ions into Y2O3 lattice could induce a remarkable increase of PL. The highest emission intensity was observed with LiF-doped Y1.84Li0.08Eu0.08O3, whose brightness was increased by a factor of 2.7 in comparison with that of Y2O3:Eu3+ films. This phosphor may promise for application to the flat panel displays.

Human periodontal ligament stem cells (hPDLSCs) have been proposed as an alternative to conventional cosmetic fillers because they display an innate ability to synthesize collagen. The aims of this study were to determine the effects of water-soluble chitin (WSC) on the proliferation and migration of hPDLSCs, and to quantify collagen synthesis in vitro and in vivo compared with human adipose-derived stem cell (hADSC)s. hPDLSCs were isolated from healthy extracted teeth, and the cell proliferation and cell migration capacities of untreated hPDLSCs (control group) and WSC-treated hPDLSCs (test group) were compared. Insoluble/soluble collagen synthesis were also assessed, and collagen related markers were evaluated including lysyl oxidase (LOX), lysyl oxidase like (LOXL)1, LOXL2, and hydroxyproline. In vivo collagen formation was examined by transplanting hyaluronic acid as a cell carrier into the subcutaneous pockets of immunocompromised mice in the control and test groups; histology and immunohistochemistry analyses were performed 4 (n=4) and 8 (n=4) weeks later. There was a dose-dependent enhancement of hPDLSCs proliferation in the test group, and a concomitant reduction in cell migration. The amount of insoluble collagen formed was greater in the test group than in the control group (p

Purpose: The marginal bone levels around implants following restoration are used as a reference for evaluating implant success and survival. Two design concepts that can reduce crestal bone resorption are the microthread and platform-switching concepts. The aims of this study were to analyze the placement of microthreaded and platform-switched implants and their short-term survival rate, as well as the level of bone around the implants. Methods: The subjects of this study were 27 patients (79 implants) undergoing treatment with microthreaded and platformswitched implants between October 2008 and July 2009 in the Dental Hospital of Yonsei University Department of Periodontology. The patients received follow-up care more than 6 months after the final setting of the prosthesis, at which time periapical radiographs were taken. The marginal bone level was measured from the reference point to the lowest observed point of contact between the marginal bone and the fixture. Comparisons were made between radiographs taken at the time of fixture installation and those taken at the follow-up visit. Results: During the study period (average of 11.8 months after fixture installation and 7.4 months after the prosthesis delivery), the short-term survival rate of microthreaded and platform-switched implants was 100% and the marginal bone loss around implants was 0.16 ± 0.08 mm, the latter of which is lower than the previously reported values. Conclusions: This short-term clinical study has demonstrated the successful survival rates of a microthread and platformswitched implant system, and that this system is associated with reduced marginal bone loss.

To evaluate the effect of vertical and periosteal-releasing incisions (PRI) on the extension of the buccal flap in a trapezoidal flap design.Thirty patients scheduled for implant surgery accompanied by bone augmentation were recruited. The amount of flap extension pulled with a minimal tension of 5 g using a dynamometer was measured before and after the first and the second vertical incisions (VI) and PRI. The results were compared based on gender, surgical site and operator's experience.The first VI extended flap length by 1.1 ± 0.6 mm, 113.4% more compared with the original flap length. The second VI increased flap length by 1.9 ± 1 mm (124.2%), and the PRI significantly extended flap length by 5.5 ± 1.5 mm (171.3%) (P0.001). The length of the first and the second VI and the amount of flap extension by each incision were compared, and there were no statistically significant differences between gender, surgical site (maxilla vs. mandible) and operator's experience (faculty vs. residents).Vertical and PRI in a trapezoidal flap design can be successfully utilized to attain tension-free primary closure during implant or periodontal surgeries. However, the PRI appears to be the only determinant key factor that can significantly extend the length of the flaps, while host- and operator-related factors might not have any significant effect on such flap extension.

Mesenchymal stem cells (MSC) could be isolated from healthy periodontal ligaments (PDL). The aims of this study were to isolate and characterize human PDL stem cells (hPDLSCs) from inflamed PDL tissue, and to evaluate their regenerative potential.Inflamed hPDLSCs (ihPDLSCs) were isolated from the inflamed PDL tissue obtained from intra-bony defects during flap surgery, and characterized by immunohistochemical staining, colony-forming unit assay, fluorescence-activated cell sorting, and mRNA expression in comparison with healthy hPDLSCs obtained from extracted teeth for orthodontic purpose. The proliferative potential and migratory potential was evaluated, and compared with healthy hPDLSCs. Regenerative potential was assessed by an in vivo ectopic transplantation model.ihPDLSCs were successfully isolated and characterized as MSCs. Both ihPDLSCs and hPDLSCs were successfully differentiated under osteogenic/cementogenic and adipogenic microenvironment. The proliferative potential did not differ between healthy hPDLSCs and ihPDLSCs, while the migratory capacity was significantly increased in ihPDLSCs (p0.05). Both groups exhibited new cementum-like tissue and related PDL fibre regeneration in an in vivo transplantation model.ihPDLSCs could be successfully isolated from inflamed PDL tissue, and they retained the regenerative potential for cementum and related PDL tissues.

The purpose of this study was to evaluate the effect of recombinant human growth/differentiation factor-5 (rhGDF-5) on periodontal wound healing/regeneration using an injectable poly-lactide-co-glycolide-acid (PLGA) composite carrier and an established defect model.Bilateral 4 × 5 mm (width × depth) one-wall, critical-size, intra-bony periodontal defects were surgically created at the second and the fourth mandibular pre-molar teeth in 15 Beagle dogs. The animals were randomized to receive (using a split-mouth design; defect sites in the same jaw quadrant getting the same treatment) rhGDF-5 high dose (188 μg/defect) versus sham-surgery control (five animals), rhGDF-5 mid dose (37 μg/defect) versus carrier control (five animals), and rhGDF-5 low dose (1.8 μg/defect) versus treatment reported elsewhere (five animals). The animals were euthanized for histometric analysis following an 8-week healing interval.Clinical healing was uneventful. The rhGDF-5/PLGA construct was easy to assemble and apply. The rhGDF-5 high dose supported significantly increased bone formation compared with the low-dose, sham-surgery, and carrier controls (p0.05) and induced significantly increased cementum formation compared with the controls (p0.05). Root resorption/ankylosis or other aberrant healing events were not observed.rhGDF-5 appears to effectively support periodontal wound healing/regeneration in a dose-dependent order; the PLGA composite appears to be an effective ease-of-use candidate for carrier technology.

Les transitions de phase structurales du (n-G 10 H 21 NH 3 ) 2 GuGl 4 cristallin ont ete etudiees par diffraction des rayons X sur poudre, spectroscopie infrarouge et analyse calorimetrique differentielle. Ce compose presente des transitions de phase par paliers avec hysteresis, trois en montee et quatre en descente de temperature. Cinq phases sont donc definies: V... III⇄II⇄I.

Ruddlesden-Popper phase, Lan+1NinO3n+1 (n = 1, 2 and ∞) compounds were prepared by citrate sol-gel method. We revealed the origin of the variation of the electrical conductivities in Lan+1NinO3n+1 (n = 1, 2 and ∞) using resistivity measurements, Rietveld analysis, and X-ray absorption spectroscopy. According to the XANES spectra, it is found that the degree of 4pπ - 4pσ energy splitting between 8345 eV and 8350 eV is qualitatively proportional to the elongation of the out-of-plane Ni-O bond length. With the decrease of 4pπ - 4pσ splitting, the strong hybridization of the σ-bonding between Ni-3d and O-2p orbitals creates narrow antibonding σ* bands, which finally results in the lower electrical resistivity.