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Millimeter-sized K2Ti2O5 single crystals were grown from a KCl–KOH mixed flux using a flux-evaporation assisted method. H2O was found to be the best solvent for the liquid exfoliation of K2Ti2O5 crystals.

Nanocrystalline powders of alkali metal titanates were prepared using titanium tetraisopropoxide and alkali metal salts by a sol–gel method. The influences of the kinds of alkali metal salts and heating temperature on the reaction of the titanium precursor compounds with the alkali metal salts, its phase transition, and crystal growth were investigated by thermal analyses, XRD measurement, and SEM observation in order to prepare lithium, sodium, and potassium titanates at relatively low temperatures. The amorphous titania gel or its product, very small titania crystals, as an intermediate phase reacted with the alkali metal salts at around 500–600 °C while it was still highly active and formed alkali metal titanate nanoparticles before forming the stable titania crystals. It is important that the active amorphous titania gels react with the dispersed alkali metal salts at a temperature as low as possible in order to form the alkali metal titanate nanocrystals.

In order to tailor the morphology of the layered double hydroxide (LDHs) particles, we focused on a synthesis method that involves the use of Al2O3 as a precursor, employing Al2O3 with different crystal structures (e.g., α-Al2O3, θ-Al2O3, and γ-Al2O3) as well as amorphous Al2O3. A three-dimensional network of plate-shaped LDH particles was formed when θ-Al2O3 and γ-Al2O3 were used, even though α-Al2O3 barely reacts to form the LDH phase. Finally, adsorption tests involving HPO42− ions confirmed that the fabricated LDH particles exhibited high ion-removal rates. The LDH particles prepared with θ-Al2O3 and γ-Al2O3 could remove the hydrogen phosphate ions (HPO42−) in a concentration of 0.40 mmol g−1 completely within 10 min; this is approximately 20 times shorter than the time taken by the LDH particles prepared from amorphous Al2O3.

Lithium–titanium oxide (β-Li2TiO3, LTO) crystals are a requisite precursor for hydrated titanium oxide [TiO(OH)2 or H2TiO3, HTO], which is a promising lithium-ion (Li+) sieve because of its high theoretical Li+-exchange capacity (LiEC) and unique crystal structure. Herein, we report the flux growth of LTO nanocrystals from LiCl and LiOH as a function of the holding temperature. The use of LiCl as a flux resulted in the growth of single-phase, monodispersed LTO nanocrystals at ≥600 °C. On the other hand, using a LiOH flux led to the growth of single-phase LTO crystals at ≥550 °C. The surface areas of the LTO samples grown from the LiCl and LiOH fluxes, LTOLiCl and LTOLiOH, respectively, reached their respective maxima of 17 and 29 m2 g–1, which are 2–4 times the value (7 m2 g–1) obtained for the LTO synthesized via a solid-state reaction at 700 °C. The resulting LTO samples were then immersed in an acid to prepare the HTO samples as adsorbents for Li+. Isotherms of Li+ adsorption on the HTO samples showed ...

Atmospheric-pressure-plasma is an effective energy source for fabricating inorganic nanocrystal–carbon composite materials in an extremely short time. In this study, nanosized fluorapatite [Ca5F(PO4)3, FAp] crystals, which are a useful adsorbent for removing metal ion contaminants from water, were directly fabricated on the surface of activated carbon (AC) using an atmospheric-pressure-plasma-jet with a high energetic density by coupling with the flux method. First, carbonyl and carboxyl groups, nucleation site, were introduced onto the surface of AC by heat treatment with KNO3 powder. Next, FAp crystals were grown on the treated AC using N2 gas-based atmospheric-pressure-plasma-jet with KNO3–LiNO3 flux whose eutectic point is 125 °C. Within 10 s, nanoscale FAp crystals with rod-like shapes were obtained, although the crystals obtained without flux were of indefinite shape. Here, we demonstrated the synergetic effect of plasma and flux, which provide high-density thermal energy and which can exist as a so...

The controlled growth of needle-shaped and planar bar-shaped NaFeTiO4 crystals, a CaFe2O4-type structure, was carried out by a flux method using a NaCl–Na2SO4 binary flux. NaCl fluxes have been empirically investigated for growing unique anisotropic crystal shapes. However, strategies for controlling the crystal morphology based on NaCl fluxes have not been established. In this study, Na2SO4 was added to a NaCl flux to supply O2− ions, which is essential for the dissolving ability of a metal oxide into ions, and the growth manner was systematically investigated as a function of flux composition. As a result, needle-shaped crystals were obtained from the pure NaCl flux with exposed {100} facets. Meanwhile, with the binary flux, the morphology of the crystals changed from a needle shape to a planar bar shape depending on the Na2SO4 content, where the aspect ratio of the {100} facets was increased by about ten times. It was found out that the aspect ratio of the {100} planes of NaFeTiO4 crystals can be controlled kinetically by the cooperative effect of Na+ ions and anionic species in the flux; Na+ ions stabilize the {100} facets and a high O2−/Cl− ratio increases the concentration of ions as a precursor for crystal growth to promote the growth in the direction, resulting in planar bar-shaped crystals. We believe that the morphological control regime demonstrated here in the growth of NaFeTiO4 crystals in a NaCl–Na2SO4 binary flux could be a useful idea in high temperature chemistry and for their desirable applications.

Understanding and controlling confined nanospace to accommodate substrates and promote high ion conduction are essential to various fields. Layered double hydroxides (LDHs) have emerged as promising candidates for anion exchangers using the interlayer nanospace in their crystal structures. Miyata reported in 1983 that the affinity of anions for intercalation with most major Mg-Al LDHs increased in the following order: NO3- < Br- < F- < SO42- < HPO32-. Attempts to alter the affinity with different metal cations (M2+ and M3+) have been unsuccessful. Analyses of the crystalline structures of LDHs, positively charged host layers, interlayer anions, and interlayer water molecules indicate that they inevitably interact through hydrogen bonding. In other words, the affinity of LDHs for anions is controlled by tuning the hydrogen bonding. In this study, we prepared fluorine-substituted LDHs (F-LDHs) with different Mg/Al ratios by partially replacing the OH structural groups, which originated from the host layer, with fluorine atoms; the resulting change in affinity was investigated. The distribution coefficient, which is a useful indicator of the affinity of an LDH for a particular anion, was examined. The results showed that only F-LDHs with Mg/Al ratios of 3.5 exhibited high affinity, especially for NO3- ions, and the affinity increased in the following order: HPO42- < SO42- < F- < Br- < NO3-. The separation factors of these specific F-LDHs with respect to both NO3-/F- and NO3-/SO42- were higher than that of LDHs with other compositions by 1 order of magnitude. Raman spectroscopy above 3000 cm-1 revealed that the fluorine substitution of LDHs significantly changed the hydrogen bonding nature in the interlayer space. Highly electronegative fluorine atoms significantly decrease the extent of hydrogen bonding interactions between OH structural groups and both interlayer water molecules and anions, wherein steric effects are induced by the shrunken interlayer space, and van der Waals forces are revealed to be the predominant interaction with anions. Therefore, the highest affinity was observed for NO3- ions in F-LDHs.

Layered double hydroxide (LDH) has emerged as promising candidates for removing harmful oxoanions (i.e., SO42–, HPO42–, and NO3– ions) from wastewater because of their intrinsic ability to accommod...

The β-Li2TiO3 crystal is an important material in several energy-related applications, and the control of its morphology and exposed facets is an important issue. Herein, we comprehensively studied the flux growth of β-Li2TiO3 crystals under different conditions and demonstrated the efficient anisotropic growth of {001}-faceted β-Li2TiO3 single crystals from the Na2SO4 flux. By examining the effects of the cation and anion in the alkali metal salt-based flux, we found that Na2SO4 flux is best for growing large, faceted β-Li2TiO3 crystals. In this flux at 1000 °C, the optimal solute concentration is 20 mol % for growing large (∼15.0 μm in lateral size), platy, and faceted β-Li2TiO3 crystals. Observations from varying the holding time and cooling rate indicated that these crystals were anisotropically grown. Transmission electron microscopy images with clear electron diffraction spots revealed that the flux-grown platy β-Li2TiO3 crystals are single crystalline solids with the {001} plane being the dominant ...

Selective lithium uptake from seawater and lake brine is an important challenge in energy and environmental science. H1.6Mn1.6O4 with pseudospinel-type structure is a highly selective adsorbent for Li ions, but it is difficult to prepare large, highly crystalline H1.6Mn1.6O4 crystals with porous structure due to its thermodynamic metastability. Herein we demonstrate simple chemical processes that transform flux-grown, idiomorphic orthorhombic LiMnO2 (o-LiMnO2) cuboids of micrometer size into hierarchically structured H1.6Mn1.6O4 rods. We have optimized the flux growth conditions such as the Mn source, holding temperature, and solute concentration in order to yield large, single-phase o-LiMnO2 particles. The use of MnO under very low solute concentration (1 mol %) and high temperature (1000 °C) is critical to obtaining the single-phase, idiomorphic o-LiMnO2 cuboids. The metastability of o-LiMnO2 is confirmed by ab initio density functional theory calculation in comparison with other lithium manganates such...

Recognition and sensing of metal ions at the atomic level is a critical issue in many fields of sciences. In particular, selective adsorption of radioactive 90Sr2+ ions from nuclear waste has been of interest since the Fukushima Daiichi nuclear disaster. Here we present a combined experimental and computational study of KTiNbO5 (KTN) as a selective and durable adsorbent for Sr2+ ions. KTN grown from nitrate flux at 500–600 °C (KTNflux) has a zigzag layered gallery space. Structural analysis indicates that KTNflux crystals are platy with surface areas of 48–86 m2 g–1. These areas are ∼50 times larger than those of KTN prepared by solid-state reaction at 1100 °C (KTNSSR) as a result of efficient, anisotropic crystal growth. Sr2+ adsorption experiments indicate that the Sr2+ ion-exchange capacity of KTNflux is ∼1.04 mmol g–1, and most of the ion-exchange sites are homogeneous. Kinetic analysis shows that the Sr2+ ion-exchange rate on KTNflux is 1 order of magnitude higher than that on KTNSSR. The [Na+] conce...

Copper–indium–gallium–sulfide–selenide (CIGSSe) is used in photovoltaic cells and photocathodes, because of its tunable optoelectronic properties, but the fabrication of CIGSSe samples usually requires a multistage process under vacuum. Herein we used a flux growth technique for the sulfide system and achieved efficient flux growth of idiomorphic copper–indium–sulfide CuInS2 crystals of size ∼5 μm from a NaCl–InCl3 flux under mild conditions at ambient pressures. We first examined the flux growth conditions such as holding temperature, solute concentration, and holding time for growing highly crystalline CuInS2 crystals. A moderate holding temperature (∼550 °C) and high solute concentration (∼70 mol %) yielded idiomorphic pure CuInS2 crystals. High-resolution transmission electron microscopy showed clear electron diffraction spots, indicating that the resultant CuInS2 crystals had a highly crystalline, intrinsic tetragonal crystal structure. Thermogravimetry-differential thermal analysis showed that the C...

Cu–In–Ga–S–Se (CIGSSe) is a promising light-absorber in thin-film photovoltaic cells, as well as a photocathode for solar H2 production, but the fabrication of layers of CIGSSe crystals on substrates is both time- and cost-intensive. Here, we report the fabrication of CuInS2 crystal layers on various precursor-loaded Mo/soda-lime glass (SLG) substrates using a flux coating method. X-ray diffraction analysis indicated that the main phase was CuInS2, while MoS2 which formed through the sulfurization of the Mo substrate was present as a minor phase. Top-surface field-emission scanning electron microscopy (FE-SEM) images indicated that the CuInS2 crystals were sparsely formed on the bare Mo/SLG, In/Mo/SLG, and Cu/Mo/SLG substrates. In contrast, closely packed CuInS2 crystals were formed on Cu2S/Mo/SLG. Smaller CuInS2 crystals 0.5–1 μm in size were grown on Cu2S/Mo/SLG compared to those on other substrates. This sharp difference in crystal population and size could be attributed to the pre-loading effect of the precursors. Cross-sectional FE-SEM analysis with energy-dispersive X-ray spectroscopy mapping revealed the homogenous fabrication of idiomorphic CuInS2 crystals on the partially sulfurized Mo substrate, yielding a CuInS2/MoS2/Mo heterostructure amenable to photovoltaic applications. The formation mechanism of this unique heterostructure was discussed based on the experimental results.

Garnet-type Li5+xLn3MIV2–yMVyO12+z (x, y = 0–2, z = 0–1; Ln = La, Pr, Nd; M = Ta, Zr, Nb) compounds are promising Li-ion conducting solid electrolytes, but their growth manner is still unclear. Herein, the analysis of the low-temperature growth of idiomorphic Li5La3Ta2O12 single crystals as a function of holding temperature and time, cooling rate, flux type, and solute concentration revealed a unique growth manner. Li5La3Ta2O12 crystals were grown at 500 °C from LiOH flux and transformed into Li7La3Ta2O13 at 700 °C. The pseudo-perovskite-type LiLa2TaO6 phase, initially formed during the holding at 500 °C, was efficiently transformed into the Li5La3Ta2O12 phase with increasing holding time. The growth of Li5La3Ta2O12 single crystals was independent of the cooling rate but was affected by the kind of flux and solute concentration. A low solute concentration (1 or 5 mol %) was the key to obtain well-dispersed and idiomorphic single crystals. The optimum growth conditions involved a holding temperature of 500...

Layered double hydroxide (LDH) is an environmentally benign anion exchanger that can adsorb various toxic anions. In this work, we demonstrate the fabrication of plate-like Mg–Al-type LDH crystals on in situ formed alumina particles using a flux method at a relatively low temperature (∼350 °C). At or below 300 °C, the melted Al source crystallized to form AlOOH or γ-alumina particles in KNO3–NaNO3 flux. However, LDH crystals did not form due to the inferior crystallization properties of the Mg precursor. Increasing the holding temperature up to 350 °C and above facilitated crystallization of the dissolved Mg and Al species in flux to yield plate-like LDH crystals on the preformed alumina particles. Top-surface and cross-sectional FE-SEM and EPMA analyses revealed the vertical alignment of the crystalline LDH plates on the surface of the alumina particles. On the other hand, solid-state reactions did not yield these well-grown, plate-like LDH crystals. The TG-DTA profile of the LDH precursors with flux dep...

FeSe-based intercalates are regarded as promising candidates for high-critical temperature (Tc) superconductors. Here we present new Na- and Sr-intercalated FeSe superconductors with embedded linear diamines (H2N)CnH2n(NH2) (abbreviated as DA; n = 0, 2, 3, or 6) prepared using a low-temperature ammonothermal method to investigate the effect of interlayer spacing on the superconductivity of electron-doped FeSes. The embedded DA formed a monolayer or bilayer in the interlayer of FeSe. The interlayer spacing between nearest FeSe layers could be tuned from 0.87 to 1.14 nm without significant change in the Na/Sr content or the ratio of Fe to Se. Importantly, bilayer phases Na/ethylenediamine- and Sr/hydrazine-FeSe show improved structural stability compared to that of Na/NH3-FeSe. The series of Na- and Sr-intercalated FeSe samples exhibited nearly the same high Tc values of 41-46 and 34-38 K, respectively, irrespective of rather different interlayer spacing d. The peculiar insensitivity for both series can be ascribed to the negligible dispersions of bands along the c axis; i.e., Fermi surfaces are nearly two-dimensional when d is larger than a certain threshold value (dsat) of ∼0.9 nm. The Fermi surface shape is already optimal for Tc, and a larger d will not enhance Tc further. On the other hand, the difference in Tc between two series may be explained by the higher carrier doping level in Na/DA-FeSes compared to that in Sr/DA-FeSes, resulting in the increased density of states at the Fermi level and superconducting pairing strength.

The additive effect of 31 metals on activity of ceria catalysts was studied for the conversion of ethanol to propene. Yttrium gave the best results and the propene yield showed a volcano-shaped dependence on the Y amount, being maximized at 20 atom% Y to that of Ce. The catalyst was stable due to very small carbon deposition rate which was approximately 1/100 of that on the parent CeO 2 catalyst. The water addition increased the propene yield to 30%, decreased the ethene yield to 37%, and did not change the durability. The physicochemical characterization of the Y/CeO 2 catalysts indicated that the surface of active catalysts was covered with a solid solution of CeO 2 and Y 2 O 3 . Pulse experiments of various candidate compounds suggested that the reaction pathways were ethanol → acetaldehyde → ethyl acetate → acetic acid → acetone → 2-propanol → propene through Tishchenko reaction, ketonization, and Meerwein–Ponndorf–Verley reduction.

Among 31 CeO2-based catalysts modified with various additives, those doped with yttrium showed the most stable activity for the conversion of ethanol to propene and ethene. The yields of propene and ethene were 25 and 50%, respectively, at 693–703 K in the absence of water and did not change after continuous catalysis over 80 h. The carbon deposition rate on the catalyst was ∼1/100 of that reported for zeolite catalysts. The addition of water into the reaction system increased the propene yield to 30% and decreased the ethene yield to 37%.

Mesoporous silicon (oxy)nitride (MS(O)N) and mesoporous silica MCM-41 (M41) were examined as supports of catalyst for ammonia synthesis from N 2 and H 2 . Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Rh, Ta, W, Ir, or Pt-loaded MS(O)N and MS(O)N itself were catalytically inert for the synthesis reaction at 673–773 K, while Re, Mo, and Ru-loaded MS(O)N were active. Among the latter metals Re showed the highest activity and thus catalytic activity of Re supported was studied as a function of support, amount of Re supported, Re precursor used in the preparation, and additive. M41 was a good support. The role of Re precursor upon activity was limited. The activity of Re/M41 increased linearly with increasing Re content in the range 0–30 wt.% and was approximately constant between 30–60 wt.% Re. The most active Re/M41 with 30 wt.% Re showed equivalent activity to those of Ru/MgO and doubly-promoted iron catalysts at an atmospheric pressure. Several additives such as Cs, Ba, La, and Ce did not increase the activity of Re/M41. Finally the activation energy and the reaction orders on the respective components on Re/M41 were determined to be 63.0 kJ mol −1 and P N 2 0.95 P H 2 0.52 P NH 3 - 1.22 at 623–693 K and an atmospheric pressure. The order on hydrogen was positive in sharp contrast to those reported on other Re catalysts and would be very important for the practical application.

Introduction: There have been increasing attention to anion-intercalation behavior and materials. In lithium ion battery field, intercalation property of PF6 − into graphitic carbon was studied for a hybrid capacitor. In ion-exchange field, selective removal of toxic anionic species by anion-exchangeable layered compounds has been focused. Layered double hydroxides (LDHs) was representative of anion-exchangeable layered compounds, represented by a general formula of [M2+ 1−x M3+ x (OH)2] x +[A nx /n ] x − mH2O consisting of octahedral brucite-like host-layers (M2+/M3+: divalent and trivalent metal cations), charge-balancing anions (A n −) and interlayer water molecules. Their ion-exchange properties, selectivity and capacity, have been widely studied. Miyata previously reported the order of affinity of various anions to Mg-Al LDHs; OH− > F− > Cl− > Br− > NO3 − > I−. Although other researchers have tried to control the affinity by changing composition of metal cations (M2+/M3+) to control charge density of host layers, significant change in the order was hardly achieved. Looking back to intrinsic crystalline structure of LDHs, host-layers, optimal positions of interlayer anions, and water molecules is supposed to be determined with hydrogen-bonding interaction among them. In other words, the affinity of anion to LDHs should be controlled by tuning strength of hydrogen-bonding in addition to charge density of host layers. In this presentation, we tried to prepare F-substituted Mg-Al LDHs (F-LDHs), OH groups belonging to host layer of LDHs was substituted by F atoms, and anion-exchange selectivity was investigated. Experiment: Based on traditional co-precipitation method with solution pH = 10, F-LDHs was prepared by using AlCl3, NaAlF6, and MgCl2·6H2O as a precursor. Mg/Al ratio was controlled as 2.5，3.0，3.5，and 4.0 by changing ([AlCl3]+[NaAlF6])/[MgCl2] ratio and F-substitution ratio was controlled by changing [AlCl3]/[NaAlF6] ratio. Crystal structure, morphology, chemical composition, local structure of Al and F atoms of obtained samples were analyzed by XRD, FE-SEM (EDS), XPS, solid-state NMR. Next, anion-exchanging properties of obtained F-LDHs was tested. Firstly, as a pre-treatment, LDHs samples was immersed in acidic NaCl aqueous solution for 24 hours at room temperature and interlayer “contaminated” carbonate was exchanged by chloride ions as much as possible. Seconds, by using chloride-exchanged samples, anion-exchange test was carried out with 1.2~1.5 mM NaNO3, Na2SO4, Na2HPO4, NaF, and NaI aqueous solutions for 24 h, where solid to liquid ratio was fixed to 1.0 gL-1. After 24 h, exchanged amount was analyzed by ion-chromatography. Results and discussion: XRD patterns of all samples exhibit successful formation of LDHs without byproducts even after chloride-exchange treatment. Successful inclusion of F atoms into host-layer of LDHs was confirmed by solid-state NMR and, in all samples, 80% of interlayer anions was exchanged by chloride ions, which is confirmed by compositional analysis with EDS and XPS. XRD patterns also revealed that the basal spacing, d 003, of F-LDHs tend to decrease comparing to original LDHs, which implies that host-layers strongly interacts with interlayer anions and water molecules. In addition, F-substitution amount was found out to be limited by about 10%, LDHs can be obtained without byproducts. Next, distribution coefficient, useful indicator of the affinity of respective anions to LDHs, was calculated from the result of ion-exchange test. It clarified that the order of affinity was NO3 − > HPO4 2− > Br− > F− > SO4 2− > I−, which is totally different from previous reports. Furthermore, the affinity of NO3 − ions comparing to SO4 2− ion and F− ions was increased depending on F-substitution amount. In conference, detailed formation mechanism of F-LDHs and anion-exchanging mechanism was presented.

Various mesoporous silicas [MCM-41(M41), SBA-15(SBA15), MCM-48(M48)] and silica gel were nitrided with ammonia in a plug-flow reactor at 1273 K. The nitrogen contents of various (oxy)nitrides obtained were increased with the amount of ammonia supplied per sample weight. The nitridation rates of silica samples were not changed with the pore sizes of the samples but with the pore structures. They were dependent on the surface areas of the parent silicas. The maximum contents of nitrogen in nitrided M41s, SBA15, M48, and silica gel were ca. 38, 35, 39, and 21 wt.-%, respectively, which indicates the great difference between the reactivity of the mesoporous silicas and silica gel. 29Si NMR and X-ray photoelectron spectroscopy also supported the progress in almost complete nitridation of the former samples. The XRD and the FE-SEM measurements revealed that the mesoporous (oxy)nitrides maintained the original 2D hexagonal or 3D cubic mesopore structures and particle morphology. Nitrogen sorption analysis showed that the pore diameters, the surface areas, and the primary mesopore volumes were varied with the nitridation degrees and the types of pore structures but there occurred no destruction of pore structures. Finally, the stabilities of the silicon (oxy)nitrides prepared were studied. The pore structures and nitrogen contents remained essentially unchanged upon storage under a nitrogen atmosphere, immersion in 1-buthanol or toluene, or by heating under H2 flow at 1073 K. Heating samples under O2 flow at 1073 K resulted in the collapse of the pore structures and a decrease in nitrogen content.

The title reaction proceeded well to yield silicon (oxy)nitride at 973–1323 K using a plug-flow reactor. The degree of nitridation was studied as a function of temperature and time of nitridation, the sample weight, and the flow rate of ammonia. It was dependent on the reaction temperature and the amount of ammonia supplied per sample weight. The nitridation at 1273 K for 10–25 h yielded the oxynitride with 36–39 wt% nitrogen, which was very close to 40 wt% of Si3N4. Characterization with X-ray diffraction, field-emission scanning electron microscopy and transmission electron microscopy measurements, and nitrogen adsorption revealed the conversion of MCM-41 to the corresponding oxynitride without essential loss of the mesoporous structure, the decrements of the lattice constant and the pore diameter by 20–35%, and the increments of the wall thickness by ca. 45%. Solid-state 29Si nuclear magnetic resonance spectra during the nitridation clearly showed fast decrease in SiO4 species and slow in SiO3(OH). Various intermediate species, SiOxNy(NH2 or NH)z, were observed to be formed and finally, ca. 70% SiN4 species, ca. 20% SiN3(NH2 or NH), and ca. 10% SiON2(NH2 or NH) were produced, being consistent with the results of the above mentioned elemental analysis.

Inflammatory bowel disease (IBD) is an idiopathic inflammatory disease of the intestine. CD4+ T lymphocytes play an important role in both initiating and regulating intestinal inflammatory immune responses. CD4+CD25+CD45RBlow regulatory T (T reg) cells are capable of preventing the development of colitis in a mouse model of IBD. The precise mechanism of T reg cell–mediated prevention of colitis in this model is unclear, and the role of chemokine receptors in the trafficking and function of T reg cells in this model has not been determined. We examined the role of the chemokine receptor CCR4 in in vivo trafficking and suppressive function of T reg cells in a mouse adoptive transfer model of IBD. CCR4-deficient T reg cells failed to accumulate in the mesenteric lymph nodes (MLNs) at early time points (2–5 d) after adoptive transfer, resulting in a failure to suppress the generation of pathogenic T cells and the development of colitis. Moreover, although CCR4-deficent T cells had equivalent in vitro suppressive activity and accumulated in MLNs at later time points (42–56 d), they were unable to suppress colitis. Our study demonstrates that CCR4 plays an important role in T reg cell trafficking in LNs and that this is critical for T reg cell suppressive function in vivo.

Na/DA and Sr/DA intercalates of FeSe (DA: (H2N)CnH2n(NH2) with n = 0, 2, 3, or 6 as electron sources and molecular spacers) are prepared by a low-temperature ammonothermal method using Na, Sr, FeSe, and condensed NH3 (high-pressure glass vessel, 273-298 K, 2-3 h) followed by the removal of intercalated NH3 (evacuation at 303-373 K).

Background Suicide attempts (SA) after psychiatric hospitalization continue to be a major cause of morbidity. Implicit measures may enhance our ability to assess suicide risk. In this context, we describe the first use of the Suicide Opinion Questionnaire (SOQ) to identify post-discharge suicide attempters. Methods Adult psychiatric inpatients admitted for suicidality (N = 91) were administered a battery of measures including the SOQ, and forty were reached and reassessed for SA at two months post-discharge. Exploratory factor analysis (EFA) on items associated with suicidality was performed to identify latent constructs. Linear discriminant analysis (LDA) was used to optimize factor combination for suicide identification. Results were compared with explicit measures of suicidality, and logistic regression was used to control for other risk factors. Finally, a simplified 9-item scale was derived from the results and its performance compared to that of the linear discriminant function. Results Twenty items differed between patients with and without SA at intake or follow-up. EFA on these identified two factors: suicide attempters indicated greater acceptability and less moral condemnation of suicide. The LDA-derived discriminant function and 9-item scale was significantly sensitive and specific for post-discharge SA. Conclusions Attitudes of acceptability and lack of condemnation toward suicide may constitute an implicit measure of suicidality that could contribute to risk assessment in a high-risk population.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by pathogenic autoantibodies against nucleoproteins and DNA. Here we show that DNA-containing immune complexes (ICs) within lupus serum (SLE-ICs), but not protein-containing ICs from other autoimmune rheumatic diseases, stimulates plasmacytoid DCs (PDCs) to produce cytokines and chemokines via a cooperative interaction between Toll-like receptor 9 (TLR9) and FcgammaRIIa (CD32). SLE-ICs transiently colocalized to a subcellular compartment containing CD32 and TLR9, and CD32+, but not CD32-, PDCs internalized and responded to SLE-ICs. Our findings demonstrate a novel functional interaction between Fc receptors and TLRs, defining a pathway in which CD32 delivers SLE-ICs to intracellular lysosomes containing TLR9, inducing a signaling cascade leading to PDC activation. These data demonstrate that endogenous DNA-containing autoantibody complexes found in the serum of patients with SLE activate the innate immune system and suggest a novel mechanism whereby these ICs contribute to the pathogenesis of this autoimmune disease.

Toll-like receptor 5 (TLR5) recognizes bacterial flagellin and activates host inflammatory responses. In this study, we examine the nature of the TLR5-flagellin interaction. With deletional, insertional and alanine-scanning mutagenesis, we precisely mapped the TLR5 recognition site on flagellin to a cluster of 13 amino acid residues that participate in intermolecular interactions within flagellar protofilaments and that are required for bacterial motility. The recognition site is buried in the flagellar filament, and monomeric flagellin, but not the filamentous molecule, stimulated TLR5. Finally, flagellin coprecipitated with TLR5, indicating close physical interaction between the molecules. These studies demonstrate the exquisite ability of the innate immune system to precisely target a conserved site on flagellin that is essential for bacterial motility.

The discovery of superconductivity in alkali-ammonia cointercalated FeSe has generated intensive interest because of their highest ${T}_{\mathrm{c}}$ (\ensuremath{\sim}45 K) among iron-chalcogenide superconductors with bulk form. Here, we report the phase diagrams of two series of Li/Na-ammonia cointercalated $\mathrm{FeS}{\mathrm{e}}_{1\ensuremath{-}z}\mathrm{T}{\mathrm{e}}_{z}$. When superconductivity is suppressed by Te doping, the magnetic ordering states are emergent. Moreover, a novel phase $\mathrm{L}{\mathrm{i}}_{x}{(\mathrm{N}{\mathrm{H}}_{3})}_{y}\mathrm{F}{\mathrm{e}}_{2\ensuremath{-}\ensuremath{\delta}}\mathrm{T}{\mathrm{e}}_{2}$ with possible antiferromagnetism is discovered. This strongly indicates the intimate relation between superconductivity and magnetism in these materials, like in other iron-based superconductors. On the other hand, comparative structure analysis with $\mathrm{FeS}{\mathrm{e}}_{1\ensuremath{-}z}\mathrm{T}{\mathrm{e}}_{z}$ suggests that although there is remarkable similarity in phase diagrams for both iron-chalcogenide and iron-pnictide superconductors, the different types of anions with different charges lead to the dissimilar controlling factors in superconductivity for both classes of materials. This opens up an opportunity to tune the superconductivity in iron-chalcogenide superconductors in more ways than just one.

[Ca24Al28O64] 4+(e-)4 electride powder with moderate surface area of 9—19 m2/g is synthesized from an 11:14 stoichiometric mixture of Ca(OH)2 and Al(OH)3, which is hydrothermally treated at 150 °C for 5 h.

Inorganic imides are useful for hydrogen storage and base-catalyzed reactions but are extremely unstable under ambient conditions, which hinders their practical use as functional materials. Here, we demonstrate that NH2(-) and H(-), as well as NH(2-), can be incorporated into the nanocages of the mayenite crystals, [Ca24Al28O64](4+)(e(-))4 and [Ca24Al28O64](4+)(O(2-))2, by ammonothermal treatment. We evaluated the reaction conditions and found that the anion exchange reaction proceeded at higher than 500 °C. Raman spectroscopy showed that the N-H band position of encaged NH(2-) was close to that of CaNH and MgNH crystals. We also studied the reaction pathways that yield NH2(-) and NH(2-) anions and their dynamic motions by (1)H NMR spectroscopy. Successive reactions of encaged e(-) and O(2-) ions with NH3 yielded NH2(-), NH(2-), and H(-) or OH(-), in which the O(2-) ion reacted more efficiently with NH3. The maximum NH(2-) concentration and content were ∼2.7 × 10(20) cm(-3) and ∼0.25 (wt %)NH, respectively. The short spin-lattice relaxation time found in (1)H NMR suggests that the incorporated NH2(-) and NH(2-) rotate or librate in the cage near room temperature. Stability tests showed that the encaged NH(2-) ions are chemically stable under ambient conditions and in organic solvents. These results are attributed to the encapsulation of active anions within subnanometer-sized cages composed of Ca-O-Al oxide frameworks. The encaged NH(2-) desorbed as NH3 at higher than 500 °C under vacuum (Ea = 172 kJ mol(-1)). It is thus expected that C12A7:NH(2-) will function as a reactive nitrogen source for nitrogen transfer reactions by in situ cage degradation.

The inorganic electride [Ca24Al28O64]4+(e−)4 (C12A7:e−) has unique properties, that is, chemical stability and a low work function comparable to that of metal K. However, its surface area is low (≈1 m2 g−1) because sintering occurs during high-temperature annealing, which is needed to remove CaO layers formed by reaction with metal Ca that works as a reductant. We report a simple synthesis method for moderate-surface-area C12A7:e− (9–19 m2 g−1) by using a rapid thermal annealing (RTA) technique. The synthesis consists of 1) high-temperature evacuation, 2) reaction with Ca metal, and 3) RTA. The influence of these synthesis conditions was first studied to achieve both high surface area and high electron concentration. Next, C12A7:e− samples were examined as Ru catalyst supports for NH3 synthesis. The activity of Ru-loaded as-prepared C12A7:e− was moderate but was increased fivefold by RTA processing prior to Ru loading as a result of surface structure reconstruction. The improvement in the Ru dispersion degree that results from the increased surface area trebled the overall activity (3550 μmol NH 3 gcat−1 h−1 at 340 °C) compared with that of conventional Ru/C12A7:e−.

The lck gene encodes a protein-tyrosine kinase that plays a key role in signaling mediated through T cell receptor (TCR) and pre-TCR complexes. Transcription of the lck gene is regulated by two independent promoter elements: the proximal and distal promoters. Previous studies employing transgenic mice demonstrated that the sequence between -584 and -240 from the transcription start site in the mouse lck proximal promoter is required for its tissue-specific expression in the thymus. In this study, we demonstrate that a Krüppel-like zinc finger protein, mtbeta (BFCOL1, BERF-1, ZBP-89, ZNF148), previously cloned as a protein that binds to the CD3delta gene enhancer, binds to the -365 to -328 region of the lck proximal promoter. mtbeta is ubiquitously expressed in various cell lines and mouse tissues. Overexpressed mtbeta is more active in T-lineage cells than B-lineage cells for transactivating an artificial promoter consisting of the mtbeta binding site and a TATA box. Activity of the lck proximal promoter was significantly impaired by mutating the mtbeta binding site or by reducing mtbeta protein expression level by using antisense mRNA. Our results indicate that mtbeta activity is regulated in a tissue-specific manner and that mtbeta is a critical transactivator for the lck proximal promoter.

The innate immune system recognizes pathogen-associated molecular patterns (PAMPs) that are expressed on infectious agents, but not on the host. Toll-like receptors (TLRs) recognize PAMPs and mediate the production of cytokines necessary for the development of effective immunity. Flagellin, a principal component of bacterial flagella, is a virulence factor that is recognized by the innate immune system in organisms as diverse as flies, plants and mammals. Here we report that mammalian TLR5 recognizes bacterial flagellin from both Gram-positive and Gram-negative bacteria, and that activation of the receptor mobilizes the nuclear factor NF-kappaB and stimulates tumour necrosis factor-alpha production. TLR5-stimulating activity was purified from Listeria monocytogenes culture supernatants and identified as flagellin by tandem mass spectrometry. Expression of L. monocytogenes flagellin in non-flagellated Escherichia coli conferred on the bacterium the ability to activate TLR5, whereas deletion of the flagellin genes from Salmonella typhimurium abrogated TLR5-stimulating activity. All known TLRs signal through the adaptor protein MyD88. Mice challenged with bacterial flagellin rapidly produced systemic interleukin-6, whereas MyD88-null mice did not respond to flagellin. Our data suggest that TLR5, a member of the evolutionarily conserved Toll-like receptor family, has evolved to permit mammals specifically to detect flagellated bacterial pathogens.

CTL can utilize three separate mechanisms for killing foreign or virally infected cells. The perforin and Fas lytic mechanisms cause rapid (4–6h) lysis of target cells; surface-bound TNF-α causes slow (18–24h) destruction of target cells. In order to assess the relative contributions of the various lytic pathways in immune reactions thought to be based on CMC, several laboratories have generated perforin-less (P0) mice. Although such mice have intact vigorous Fas and TNF-α lytic pathways, they are unable to clear infection by LCMV. On the other hand, they are able to reject allografts. The implications of this for CTL function in vivo are discussed.