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Enzyme-activatable photoacoustic probes are powerful contrast agents to visualize diseases in which a specific enzyme is overexpressed. In this study, aluminum and silicon naphthalocyanines (AlNc and SiNc, respectively) conjugated with matrix metalloprotease-2 (MMP-2)-responsive PLGLAG peptide sequence and poly(ethylene glycol) (PEG) as an axial ligand were designed and synthesized. AlNc-peptide-PEG conjugates AlNc- pep -PEG formed dimeric species interacting with each other through face-to-face H-aggregation in water, while SiNc-based conjugates SiNc- pep -PEG hardly interacted with each other because of the two bulky hydrophilic axial ligands. Both conjugates formed spherical nanometer-sized self-assemblies in water, generating photoacoustic waves under near-infrared photoirradiation. The treatment of MNc-peptide-PEG conjugates (M = Al, Si) with MMP-2 smoothly induced the cleavage of the PLGLAG sequence to release the hydrophilic PEG moiety, resulting in the aggregation of MNcs. By comparing the PA signal intensity changes at 680 and 760 nm, the photoacoustic signal intensity ratios were shown to be enhanced by 3-5 times after incubation with MMP-2. We demonstrated that MNc-peptide-PEG conjugates (M = Al, Si) could work as activatable photoacoustic probes in the in vitro experiment of MMP-2-overexpressed cell line HT-1080 as well as the in vivo photoacoustic imaging of HT-1080-bearing mice.

Parkinson's disease (PD) is the second most common neurological disorder, associated with decreased dopamine levels in the brain. The goal of this study was to assess the potential of a regenerative medicine-based cell therapy approach to increase dopamine levels. In this study, we used rat adrenal pheochromocytoma (PC12) cells that can produce, store, and secrete dopamine. These cells were microencapsulated in the selectively permeable polymer membrane to protect them from immune responses. For fabrication of the microcapsules, we used a modified Buchi spray dryer B-190 that allows for fast manufacturing of microcapsules and is industrially scalable. Size optimization of the microcapsules was performed by systematically varying key parameters of the spraying device. The short- and long-term stabilities of the microcapsules were assessed. In the in vitro study, the cells were found viable for a period of 30 days. Selective permeability of the microcapsules was confirmed via dopamine release assay and micro BCA protein assay. We found that the microcapsules were permeable to the small molecules including dopamine and were impermeable to the large molecules like BSA. Thus, they can provide the protection to the encapsulated cells from the immune cells. Griess's assay confirmed the non-immunogenicity of the microcapsules. These results demonstrate the effective fabrication of microcapsules encapsulating cells using an industrially scalable device. The microcapsules were stable, and the cells were viable inside the microcapsules and were found to release dopamine. Thus, these microcapsules have the potential to serve as the alternative or complementary treatment approach for PD.

The Anderson-type hexamolybdoaluminate functionalized with lauric acid (LA), (TBA) 3 [Al(OH) 3 Mo 6 O 18 {(OCH 2 ) 3 CNHCOC 11 H 23 }]·9H 2 O (TBA-AlMo 6 -LA, where TBA = tetrabutylammonium), was prepared via two synthetic routes and characterized by thermogravimetric and elemental analyses, mass spectrometry, IR and 1 H NMR spectroscopy, and powder and single-crystal X-ray diffraction. The interaction of TBA-AlMo 6 -LA with human serum albumin (HSA) was investigated via fluorescence and circular dichroism spectroscopy. The results revealed that TBA-AlMo 6 -LA binds strongly to HSA (63% quenching at an HSA/TBA-AlMo 6 -LA ratio of 1:1), exhibiting static quenching. In contrast to TBA-AlMo 6 -LA, the nonfunctionalized polyoxometalate, Na 3 (H 2 O) 6 [Al(OH) 6 Mo 6 O 18 ]·2H 2 O (AlMo 6 ), showed weak binding toward HSA (22% quenching at a HSA/AlMo 6 ratio of 1:25). HSA binding was confirmed by X-ray structure analysis of the HSA-Myr-AlMo 6 -LA complex (Myr = myristate). These results provide a promising lead for the design of novel polyoxometalate-based hybrids that are able to exploit HSA as a delivery vehicle to improve their pharmacokinetics and bioactivity.

Hydrotalcite or Mg-Al LDHs were synthesized by co-precipitation method. The Mg-Al mixed oxide was then derived by calcination of hydrotalcite at 450°C. The metal modified catalysts (Mo/Mg-Al and V/Mg-Al) were prepared by incipient wetness impregnation method. The obtained catalysts were characterized by several useful techniques and tested the reactivity for dehydrogenation and oxidative dehydrogenation of ethanol (gas-phase) to produce acetaldehyde. The catalytic reactions were performed at temperature range from 200 to 400°C for both non-oxidative and oxidative atmospheres. The results showed that the vanadium-modified hydrotalcite (V/Mg-Al) exhibited the highest ethanol conversion (34.3%) and acetaldehyde yield (15.5%) at 400℃ in the non-oxidative atmosphere. For the oxidative dehydrogenation of ethanol, the V/Mg-Al catalyst showed the highest activity at 400°C giving the ethanol conversion and acetaldehyde yield of 73.7% and 29.5%, respectively. This result probably related to the highest base density of V/Mg-Al catalyst (6.13 µmol CO 2 /m 2 ) measured by CO 2 -TPD. The catalytic activity of Mg-Al catalyst and metal modified catalyst slightly decreased upon time-on-stream test for 10 h on oxidative dehydrogenation of ethanol due to carbon deposition.

Modulating the local environment around the emitting ions with component screening to increase the quantum yield and thermal stability is an effective and promising strategy for the design of high-performance fluorescence materials. In this work, smaller Lu 3+ was introduced into the La 3+ site in a Mn 4+ -activated LaAlO 3 phosphor with the expectation of improving the luminescence properties via lattice contraction induced by cation substitution. Finally, a La 1- x Lu x AlO 3 :Mn 4+ ( x = 0-0.04) perovskite phosphor with a high quantum yield of 86.0% and satisfactory thermal stability was achieved, and the emission peak at 729 nm well matches with the strongest absorption peak of the Phytochrome P FR . The favorable performances could be attributed to the suppressed cell volume and superior lattice rigidity after the substitution of Lu 3+ . This work not only obtains a highly efficient La 1- x Lu x AlO 3 :Mn 4+ ( x = 0.02) phosphor, which holds great potential for application in plant-cultivation light-emitting diodes, but also provides an applicable strategy for further investigation of far-red-emitting phosphors.

Objective: To synthetize calcium aluminate (C3A) and silver-containing C3A particles (C3A+Ag) testing their effects on the properties of a MTA-based endodontic sealer in comparison to an epoxy resin- and a calcium silicate-based sealer., Methods: Pure C3A and C3A+Ag particles were synthesized by a chemical method and characterized using XRD to identify crystalline phases. SEM/EDS analysis investigated morphology, particle size, and elemental composition of particles. Setting time, flow, radiopacity, water sorption and solubility of commercial and modified sealers were evaluated according to ISO 6876/2012. The pH and ions release were measured using a pHmeter and a microwave induced plasma optical emission spectrometer. The inhibition of biofilm growth was evaluated by confocal laser scanning microscopy (CLSM). Data were rank transformed and analyzed by ANOVA and Tukey test (P<0.05)., Results: The C3A particles showed an irregular grain agglomerated structure with voids and pores. In C3A+Ag particles, Ag modified the material morphology, confirming the deposition of Ag. The physicochemical properties of the modified MTA-based sealer were similar to the commercial material, except for the significant increase in Ca +2 release. However, there was no Ag release. Setting time, flow, radiopacity, water sorption and solubility were adequate for all materials. All the materials showed alkaline pH. Antibiofilm effect was improved in the presence of C3A particles, while the biofilm inhibition was lower in the presence of Ag., Significance: The modified sealer presented improved antibiofilm properties and calcium release, without dramatic effects on the other characteristics. It is expected a positive effect in its antimicrobial behavior., (Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)

Submicron Ti3AlC2 grains are grown in molten salt. Etching the grains gives rise to small-sized Ti3C2Tx MXene particulates with capacitance more than twice that of the large ones derived from conventional high-temperature synthesis. Detailed electrochemical, structural, and spectroscopic studies demonstrate that increased capacitance predominantly originates from a decrease in the lateral size of the small Ti3C2Tx MXene particulates.

Feature selection has been regarded as an effective tool to help researchers understand the generating process of data. For mining the synthesis mechanism of microporous AlPOs, this paper proposes a novel feature selection method by joint l 2,1 norm and Fisher discrimination constraints (JNFDC). In order to obtain more effective feature subset, the proposed method can be achieved in two steps. The first step is to rank the features according to sparse and discriminative constraints. The second step is to establish predictive model with the ranked features, and select the most significant features in the light of the contribution of improving the predictive accuracy. To the best of our knowledge, JNFDC is the first work which employs the sparse representation theory to explore the synthesis mechanism of six kinds of pore rings. Numerical simulations demonstrate that our proposed method can select significant features affecting the specified structural property and improve the predictive accuracy. Moreover, comparison results show that JNFDC can obtain better predictive performances than some other state-of-the-art feature selection methods., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Millions of people around the world become blind due to losing a part of the retina cells. In tissue engineering field one way to address this issue is to develop a retina tissue by scaffolds based on structure and signals received These scaffolds can play an essential role in repair and reformation of the damaged retina tissue. Here, SrAl2O4: Eu(2+), Dy(3+) nanophosphor were prepared by sol-gel method and then coated with PEG to become biocompatible. Next 10%, 30% and 50% concentration of the coated nanophosphors were dispersed in CS-PCL copolymer and electrospuned to form SrAl2O4: Eu(2+), Dy(3+)/CS-PCL scaffolds. The aforementioned photo -luminescence-scaffolds were studied for their optical, mechanical and morphological characteristics finally the effect of these scaffolds on the mice RPCs cells' proliferation and differentiation was observed. The 30% nanophosphor dispersion scaffold while providing adequate mechanical flexibility and integrity, and exhibiting superior proliferation rates and acceptable differentiation into retinal neural cells (particularly photo receptors retinal) is suggested as a promising choice in retinal tissue repair., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Honeycomb-like AlPO4-11 macrostructures built of hollow tubular arrays have been directly achieved in a eutectic mixture. A time-dependent study reveals that the formation process obeys in situ epitaxial growth and phase transformation mechanisms.

In this paper a novel and inexpensive route for the preparation of spinel magnesium aluminate nanoparticles (MgAl2O4) is proposed. Magnesium aluminate photocatalyst was synthesized via sol-gel auto combustion method using oxalic acid, urea, and citric acid fuels at 350°C. Subsequently, the burnt samples were calcined at different temperatures. The pure spinel MgAl2O4 with average crystallite size 27.7, 14.6 and 15.65nm was obtained at 800°C calcinations using the aforementioned fuels, respectively. The obtained samples were characterized by powder X-ray diffraction, Fourier transform infrared, UV-Vis spectroscopy, transmission electron microscope, scanning electron microscope. The photo catalytic activity of MgAl2O4 product was studied by performing the decomposition of Reactive Red Me 4BL dye under UV illumination or sunlight irradiation. The dye considerably photocatalytically degraded by 90.0% and 95.45% under UV and sunlight irradiation, respectively, within ca. 5h with pseudo first order rate constants of 5.85×10(-3) and 8.38×10(-3)min(-1), respectively., (Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.)

A simple and inexpensive combustion method was used to prepare Fe(3+) doped YAlO3 perovskite within few minutes at low temperature (400±10°C). This might be useful in lowering the cost of the material. The final products were well characterized by various spectroscopic techniques such as PXRD, SEM, TEM, FTIR and UV-Visible. The average crystallite size was estimated from the broadening of the PXRD peaks and found to be in the range 45-90nm, the results were in good agreement with the W-H plots and TEM. The crystallites show dumbbell shape, agglomerated particles with different size. The TL glow curves of 1-5kGy γ-irradiated YAlO3:Fe(3+) (0.1mol%) nanopowder warmed at a heating rate of 3°Cs(-1) records a single glow peak at ∼260°C. The kinetic parameters namely activation energy (E), order of kinetics (b) and frequency factor (s) were determined at different gamma doses using the Chens glow peak shape method and the results were discussed in detail. The photoluminescence spectra for Fe(3+) (0.1-0.9mol%) doped YAlO3 records the lower energy band at 720nm ((4)T1 (4G)→(6)A1 (6S)) and the intermediate band located at 620nm ((4)T2 ((4)G)→(6)A1 (6S)) with the excitation of 378nm. The higher energy band located at 514nm was associated to (4)E+(4)A1 ((4)G)→(6)A1 (6S) transition. The resonance signals at g values 7.6, 4.97, 4.10, 2.94, 2.33 and 1.98 were observed in EPR spectra of Fe(3+) (0.1-0.9mol%) doped YAlO3 recorded at room temperature. The g values indicate that the iron ions were in trivalent state and distorted octahedral site symmetry was observed., (Copyright © 2014 Elsevier B.V. All rights reserved.)

In this approach, synthesis of nickel (II) incorporated aluminophosphate (NiAlPO-5) was performed by using hydrothermal method. The diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) techniques were applied in order to characterize synthesized compounds. The NiAlPO-5 was used as a modifier in carbon paste electrode for the selective determination of thioridazine which is an antidepressant drug. This research is the first example of an aluminophosphate being employed in electroanalysis. The effective catalytic role of the modified electrode toward thioridazine oxidation can be attributed to the electrocatalytic activity of nickel (II) in the aluminaphosphate matrix. In addition, NiAlPO-5 has unique properties such as the high specific surface area which increases the electron transfer of thioridazine. The effects of varying the percentage of modifier, pH and potential sweep rate on the electrode response were investigated. Differential pulse voltammetry was used for quantitative determination as a sensitive method. A dynamic linear range was obtained in the range of 1.0×10(-7)-1.0×10(-5)mol L(-1). The determination of thioridazine in real samples such as commercial tablets and human serum was demonstrated., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The selective synthesis and in situ characterization of aqueous Al-containing clusters is a long-standing challenge. We report a newly developed integrated platform that combines (i) a selective, atom-economical, step-economical, scalable synthesis of Al-containing nanoclusters in water via precision electrolysis with strict pH control and (ii) an improved femtosecond stimulated Raman spectroscopic method covering a broad spectral range of ca. 350-1,400 cm(-1) with high sensitivity, aided by ab initio computations, to elucidate Al aqueous cluster structures and formation mechanisms in real time. Using this platform, a unique view of flat [Al13(μ3-OH)6(μ2-OH)18(H2O)24](NO3)15 nanocluster formation is observed in water, in which three distinct reaction stages are identified. The initial stage involves the formation of an [Al7(μ3-OH)6(μ2-OH)6(H2O)12](9+) cluster core as an important intermediate toward the flat Al13 aqueous cluster.

The direct synthesis of NaAlH4 has been studied, for the first time, by in situ (27)Al and (23)Na wide-line NMR spectroscopy using high pressure NMR apparatus. Na3AlH6 formation is observed within two minutes of hydrogen addition, while NaAlH4 is detected after a total of four minutes. This indicates the formation of the hexahydride does not proceed to completion before the formation of the tetrahydride ensues.

Two series of ligand precursors [2-OH-3-(CH(2)NR(2))-5-MeC(6)H(2)](2)CH(2) (1: NR(2) = NMe(2); 2: NR(2) = N(CH(2))(4); 3: NR(2) = N(CH(2))(5); 4: NR(2) = N(Me)Ph) and [2-OH-3-(CH=NR)-5-MeC(6)H(2)](2)CH(2) (10: R = 2,6-Pr(2)(i)C(6)H(3); 11: R = p-MeC(6)H(4); 12: R = p-ClC(6)H(4); 13: R = p-MeOC(6)H(4); 14: R = Bu(t)) were prepared. These compounds reacted with AlMe(3) to afford corresponding dinuclear aluminum complexes [AlMe(2){2-O-3-(CH(2)NR(2))-5-MeC(6)H(2)}](2)CH(2) (6: NR(2) = NMe(2); 7: NR(2) = N(CH(2))(4); 8: NR(2) = N(CH(2))(5); 9: NR(2) = N(Me)Ph) and [AlMe(2){2-O-3-(CH=NR)-5-MeC(6)H(2)}](2)CH(2) (15: R = 2,6-Pr(2)(i)C(6)H(3); 16: R = p-MeC(6)H(4); 17: R = p-ClC(6)H(4); 18: R = p-MeOC(6)H(4); 19: R = Bu(t)). All the compounds were characterized by (1)H and (13)C NMR spectroscopy and elemental analyses. Complexes 6 and 16 were additionally characterized by single crystal X-ray diffraction techniques. Catalysis of the aluminum complexes towards the ring-opening polymerization of rac-lactide was evaluated in the presence of benzyl alcohol. All the polymerization reactions proceed in a controlled manner.

Introduction: The aim of this study was to evaluate the effect of various mixing techniques including mechanical and manual mixing as well as the effect of ultrasonic agitation during placement on the compressive strength of mineral trioxide aggregate (MTA)., Methods: Tooth-colored ProRoot MTA (Dentsply Maillefer, Ballaigues, Switzerland) and white MTA Angelus (Angelus Soluções Odontologicas, Londrina, Brazil) were used. One gram of each powder was mixed with a 0.34-g aliquot of distilled water. Specimens were mixed either by mechanical mixing of capsules for 30 seconds at 4,500 rpm or by a saturation technique and the application of a condensation pressure of 3.22 MPa for 1 minute. Half of the specimens were placed in stainless steel molds and agitated using indirect ultrasonic activation. All specimens were subjected to compressive strength testing after 4 days., Results: The compressive strength values of ProRoot MTA were significantly greater than those of MTA Angelus (P < .05). The highest compressive strength values were recorded from ProRoot MTA samples that were mixed mechanically and placed using ultrasonic activation (mean = 101.71 MPa), whereas the lowest values were recorded for MTA Angelus samples that were mixed manually and placed without ultrasonic activation (mean = 53.47 MPa). Ultrasonically agitated groups had higher compressive strength values (P < .001). The specimens mixed mechanically had higher compressive strength values than those mixed manually (P < .05)., Conclusions: The compressive strength values of ProRoot MTA were significantly greater than those of MTA Angelus. Mechanical mixing enhanced the compressive strength of the material. Regardless of the mixing techniques applied, ultrasonic agitation improved the compressive strength of the material., (Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Long persistence phosphor CaAl4O7:Eu(2+), Dy(3+) were prepared by a combustion method. The phosphors were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), decay time measurement techniques and photoluminescence spectra (PL). The CaAl4O7:Eu(2+), Dy(3+) phosphor showed a broad blue emission, peaking at 445 nm when excited at 341 nm. Such a blue emission can be attributed to the intrinsic 4f → 5d transitions of Eu(2+) in the host lattices. The lifetime decay curve of the Dy(3+) co-doped CaAl4O7:Eu(2+) phosphor contains a fast decay component and another slow decay one. Surface morphology also has been studied by SEM. The calculated CIE colour chromaticity coordinates was (0.227, 043). We have also discussed a possible long-persistent mechanism of CaAl4O7:Eu(2+), Dy(3+) phosphor. All the results indicate that this phosphor has promising potential for practical applications in the field of long-lasting phosphors for the purposes of sign boards and defence., (Copyright © 2011 John Wiley & Sons, Ltd.)

For the first time, aluminium fluorides in liquid phase are available for optical applications. By modifying the conditions of the fluorolytic sol-gel synthesis of aluminium fluorides transparent sols with low viscosities were obtained. These sols consist mainly of small oligomeric or cluster units of aluminium fluoride which are not measurable by DLS, WAXS, SAXS and show unusual narrow signals in solid state NMR. Isolated particles with diameters up to five nanometers can be identified by TEM measurements and allow the use of their sols in optical and anti reflecting coatings. The sol particles were modified by trifluoroacetic acid to prevent agglomeration, and as a result, the obtained xerogels can be re-dispersed transparently in organic solvents.

Introduction: Mineral trioxide aggregate (MTA) satisfies most of the ideal properties of a surgical root-end filling and perforation repair material. It has been found to be nontoxic, noncarcinogenic, nongenotoxic, biocompatible, insoluble in tissue fluids, and dimensionally stable and promotes cementogenesis. The major disadvantages are its long setting time and difficult handling characteristics during placement when performing endodontic procedures. MTA is similar to Portland cement (PC) in both composition and properties. The cement industry has used many additives to decrease the setting time of PC. Proprietary formulas of PC additives include fluorosilicates, which decrease setting time. The purpose of this pilot study was to determine whether sodium fluorosilicate (SF) could be used to decrease the setting time without adversely affecting the compressive strength of PC., Methods: To determine the most appropriate amount of SF to add to PC to decrease its setting time, 1%, 2%, 3%, 4%, 5%, 10%, and 15% SF by weight were added to PC and compared with PC without SF. Setting times were measured by using a Gilmore needle, and compressive strengths were determined by using a materials testing system at 24 hours and 21 days., Results: Statistical analysis was performed by using one-way analysis of variance with post hoc Games-Howell test. None of the percentages of SF were effective in changing the setting time of PC (P > .05), and the SF additives were found to decrease the compressive strength of PC (P < .001)., Conclusions: On the basis of the conditions of this study, SF should not be used to decrease setting time and increase the compressive strength of PC and as such does not warrant further testing with MTA., (Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The main purpose of this study was to evaluate the biocompatibility and bioactivity of a new mineral trioxide aggregate (MTA)-based endodontic sealer, MTA Fillapex (MTA-F; Angelus, Londrina, Brazil), in human cell culture., Methods: Human osteoblast-like cells (Saos-2) were exposed for 1, 2, 3, and 7 days to MTA-F, Epiphany SE (EP-SE; SybronEndo, Orange, CA), and zinc oxide-eugenol sealer (ZOE). Unexposed cultures were the control group (CT). The viability of the cells was assessed by MTT assay and the morphology by scanning electron microscopy (SEM). The bioactivity of MTA-F was evaluated by alkaline phosphatase activity (ALP) and the detection of calcium deposits in the culture with alizarin red stain (ARS). Energy-dispersive X-ray spectroscopy (EDS) was used to chemically characterize the hydroxyapatite crystallites (HAP). Saos-2 cells were cultured for 21 days for ARS and SEM/EDS. ARS results were expressed as the number of stained nodules per area. Statistical analysis was performed with analysis of variance and Bonferroni tests (P < .01)., Results: MTA-F exposure for 1, 2, and 3 days resulted in increased cytotoxicity. In contrast, viability increased after 7 days of exposure to MTA-F. Exposure to EP-SE and ZOE was cytotoxic at all time points. At day 7, ALP activity increase was significant in the MTA-F group. MTA-F presented the highest percentage of ARS-stained nodules (MTA-F > CT > EP-SE > ZOE). SEM/EDS analysis showed hydroxyapatite crystals only in the MTA-F and CT groups. In the MTA-F group, crystallite morphology and chemical composition were different from CT., Conclusions: After setting, the cytotoxicity of MTA-F decreases and the sealer presents suitable bioactivity to stimulate HAP crystal nucleation., (Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Colloidal Cu@CuAlO(2)-Al(2)O(3) bimetallic nanoparticles were prepared by a gamma irradiation method in an aqueous system in the presence of polyvinyl pyrrolidone (PVP) and isopropanol respectively as a colloidal stabilizer and scavenger of hydrogen and hydroxyl radicals. The gamma irradiation was carried out in a (60)Co gamma source chamber with different doses up to 120 kGy. The formation of Cu@CuAlO(2)-Al(2)O(3) nanoparticles was observed initially by the change in color of the colloidal samples from colorless to brown. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of bonds between polymer chains and the metal surface at all radiation doses. Results of transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD) showed that Cu@CuAlO(2)-Al(2)O(3) nanoparticles are in a core-shell structure. By controlling the absorbed dose and precursor concentration, nanoclusters with different particle sizes were obtained. The average particle diameter increased with increased precursor concentration and decreased with increased dose. This is due to the competition between nucleation, growth, and aggregation processes in the formation of nanoclusters during irradiation.

A vertex-shared tetrahedral [Al(4)(OH)(6)(H(2)O)(12)](6+) (Al(4)) and a disordered [Al(H(2)O)(6)](3+) (Al(1)) that coexist in a 1:2 ratio within each unit cell were observed in the structure of [Al(4)(OH)(6)(H(2)O)(12)][Al(H(2)O)(6)](2)Br(12), which crystallized in a cubic Fd3m space group from a spontaneously hydrolyzed solution of AlBr(3). The former is composed of four AlO(6) octahedra that are connected to each other by sharing three vertexes of each octahedron and form a large regular tetrahedron with ideal T(d) symmetry. The central Al(3+) ion of the latter is coordinated by 6 disordered OH(2) molecules, that form a core-shell structure with ideal D(3d) symmetry.

The feasibility of partially substituting raw materials with municipal solid waste incineration (MSWI) fly ash in sulfoaluminate cement (SAC) clinker production was investigated by X-ray diffraction (XRD), compressive strength and free expansion ratio testing. Three different leaching tests were used to assess the environmental impact of the produced material. Experimental results show that the replacement of MSWI fly ash could be taken up to 30% in the raw mixes. The good quality SAC clinkers are obtained by controlling the compositional parameters at alkalinity modulus (C(m)) around 1.05, alumina-sulfur ratio (P) around 2.5, alumina-silica ratio (N) around 2.0~3.0 and firing the raw mixes at 1250 °C for 2h. The compressive strengths of SAC are high in early age while that develop slowly in later age. Results also show that the expansive properties of SAC are strongly depended on the gypsum content. Leaching studies of toxic elements in the hydrated SAC-based system reveal that all the investigated elements are well bounded in the clinker minerals or immobilized by the hydration products. Although some limited positive results indicate that the SAC prepared from MSWI fly ash would present no immediate thread to the environment, the long-term toxicity leaching behavior needs to be further studied., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Calcium sulfoaluminate (CSA) cements show some desirable environmentally friendly features that include the possibility of using several industrial byproducts as raw materials in their manufacturing process. Alumina powder, from the secondary aluminum manufacture, and anodization mud, from the production process of anodized aluminum, have proved to be suitable as partial or total substitutes for an expensive natural material like bauxite. CSA clinker generating raw mixtures, containing limestone, natural gypsum, bauxite, and/or one of the alumina-rich byproducts, were heated 2 h in a laboratory electric oven at temperatures ranging from 1150 to 1300 °C. Conversion of reactants into 4CaO·3Al(2)O(3)·SO(3) (the key component of CSA cements), evaluated using X-ray diffraction (XRD) analysis, increased with an increase of both burning temperature and byproduct concentration. When examined through differential thermogravimetric and XRD analyses, a synthetic CSA clinker (made from the raw mixture incorporating alumina powder as a total replacement of bauxite) mixed with 20% gypsum showed a hydration behavior almost similar to that of an industrial CSA cement containing the same amount of gypsum.

Nicotine (NCT) buccal tablets consisting of sodium alginate (SA) and nicotine-magnesium aluminum silicate (NCT-MAS) complexes acting as drug carriers were prepared using the direct compression method. The effects of the preparation pH levels of the NCT-MAS complexes and the complex/SA ratios on NCT release, permeation across mucosa, and mucoadhesive properties of the tablets were investigated. The NCT-MAS complex-loaded SA tablets had good physical properties and zero-order release kinetics of NCT, which indicate a swelling/erosion-controlled release mechanism. Measurement of unidirectional NCT release and permeation across porcine esophageal mucosa using a modified USP dissolution apparatus 2 showed that NCT delivery was controlled by the swollen gel matrix of the tablets. This matrix, which controlled drug diffusion, resulted from the molecular interactions of SA and MAS. Tablets containing the NCT-MAS complexes prepared at pH 9 showed remarkably higher NCT permeation rates than those containing the complexes prepared at acidic and neutral pH levels. Larger amounts of SA in the tablets decreased NCT release and permeation rates. Additionally, the presence of SA could enhance the mucoadhesive properties of the tablets. These findings suggest that SA plays the important role not only in controlling release and permeation of NCT but also for enhancing the mucoadhesive properties of the NCT-MAS complex-loaded SA tablets, and these tablets demonstrate a promising buccal delivery system for NCT.

The nanocage compound crystal [Ca24Al28O64]4+(e-)4 (C12A7:e-) is a room-temperature-stable electride. Although bulk C12A7:e- exhibits metallic conduction, the surface of an as-prepared sample or one prepared by mechanical fracture in ultrahigh vacuum is almost insulating and exhibits distinct non-ohmic contact. We studied whether the intrinsic surface of this electride exhibits metallic conduction or not by examining various conditions for preparing the intrinsic surface. A combination of sputtering with thermal annealing led to the emergence of metallic conductivity in a specific condition. Suitably prepared surfaces revealed ohmic contact even in an ambient atmosphere. Atomic-resolution scanning tunneling microscopy (STM) images of the surfaces were consistent with a structural model in which the cage structure in the bulk C12A7:e- electride is conserved at the surface.

The giant polyaluminum species [Al32O8(OH)60(H2O)28(SO4)2](16+) (S-Al32) and [Al13O4(OH)25(H2O)10(SO4)](4+) (S-K-Al13) [S means that sulfate ions take part in coordination of the aluminum polycation; K represents the Keggin structure] were obtained in the structures of [Al32O8(OH)60(H2O)28(SO4)2][SO4]7[Cl]2·30H2O and [Al13O4(OH)25(H2O)10(SO4)]4[SO4]8·20H2O, respectively. They are the first two aluminum polyoxocations coordinated by sulfate ions. The "core-shell" structure of S-Al32 is similar to that of Al30, but the units are linked by two [Al(OH)2(H2O)3(SO4)](-) groups with replacement of four η(1)-H2O molecules. The structure of S-K-Al13 is similar to the well-known structure of ε-K-Al13, but the units are linked by two (SO4(2-))0.5 with replacement of a H3O(+) ion. It was shown that strong interaction exists between the polyoxocations and counterions. On the basis of their structural features and preparation conditions, a formation and evolution mechanism (from ε-K-Al13 to S-K-Al13 and S-Al32) has been proposed. A local basification degree symmetrical equalization principle was extracted based on a comparison of the calculated results of the local basification degree for each central Al(3+) ion included in a polycation. They can be used to explain how the two aluminum species are formed and evolved and why the sulfate ions can coordinate to them and to predict where the OH-bridging positions will be upon further hydrolysis.

A new porous metal-organic framework (MOF)-type aluminum pyromellitate (MIL-121 or Al(OH)[H(2)btec]·(guest), (guest = H(2)O, H(4)btec = pyromellitic acid) has been isolated by using a high-throughput synthesis method under hydrothermal conditions. Its structure was determined from powder X-ray diffraction analysis using synchrotron radiation (Soleil, France) and exhibits a network closely related to that of the MIL-53 series. It is a three-dimensional (3D) framework containing one-dimensional (1D) channels delimited by infinite trans-connected aluminum-centered octahedra AlO(4)(OH)(2) linked through the pyromellitate ligand. Here the organic ligand acts as tetradendate linker via two of the carboxylate groups. The two others remain non-bonded in their protonated form, and this constitutes a rare case of the occurrence of both bonding and non-bonding organic functionalities of the MOF family. The non-coordinated -COOH groups points toward the channels to get them an open form configuration. Within the tunnels are located unreacted pyromellitic acid and water species, which are evacuated upon heating, and a porous MIL-121 phase is obtained with a Brunauer-Emmett-Teller (BET) surface area of 162 m(2) g(-1). MIL-121 has been characterized by IR, thermogravimetry (TG) analyses, and solid state NMR spectroscopy employing a couple of two-dimensional (2D) techniques such as (1)H-(1)H SQ-DQ BABA, (1)H-(1)H SQ-SQ RFDR, (27)Al{(1)H} CPHETCOR and (27)Al MQMAS.

A new synthetic protocol for the LiAlH(4)-promoted reduction of non-activated aziridines under microwave conditions was developed. Thus, ring opening of 2-(acetoxymethyl)aziridines provided the corresponding beta-amino alcohols, which were then used as eligible substrates in the synthesis of 5-methylmorpholin-2-ones via condensation with glyoxal in THF. The same procedure was applied for the preparation of novel 5(R)- and 5(S)-methylmorpholin-2-ones starting from the corresponding enantiopure 2-(hydroxymethyl)aziridines. Additionally, 2-(methoxymethyl)- and 2-(phenoxymethyl)aziridines were treated with LiAlH(4) under microwave irradiation, giving rise to either isopropylamines or 1-methoxypropan-2-amines depending on the reaction conditions.

Tripropylamine (TPA) is a template for the synthesis of porous AlPO(4)-5, whose calcination in the absence of air leads to the formation of 4 A single-walled carbon nanotubes. The thermal dissociation of TPA is the first step in this remarkable process. We examined the dissociation mechanisms of TPA by first principles calculations, under three types of conditions. In the gas phase, the unimolecular dissociation was a complex process initiated by the breaking of either the N-C(alpha) and the C(alpha)-C(beta) bonds. Within a confined space inside neutral zeolitic channels, the diffusion of H radicals enhanced a cycle of reactions to produce dipropylamine and monopropylamine, in agreement with experimental observations. In the presence of an acidic site, the dissociation of TPA was catalyzed to produce ammonia and propylene molecules, which were identified as the precursors for the eventual formation of carbon nanotubes., (Copyright 2010 Wiley Periodicals, Inc.)

Aim: To evaluate the influence of various mixing procedures including ultrasonic vibration, trituration of customized encapsulated mineral trioxide aggregate (MTA) and condensation on the Vickers surface microhardness of MTA., Methodology: ProRoot MTA Original, ProRoot MTA (white), MTA-Angelus (grey) and MTA White Angelus (white) were prepared using several mixing techniques including ultrasonic vibration, trituration of customized encapsulated MTA and conventional condensation. Twelve experimental groups (four materials: three techniques) were evaluated, each with 35 samples. All samples were incubated after preparation and subjected to Vickers surface microhardness testing after 4 and 28 days. Data was were subjected to a two-way anova., Result: At 28 days, the surface microhardness value was significantly greater for all experimental groups compared to 4 days after mixing (P < 0.00001). The application of ultrasonic energy to MTA produced significantly higher surface microhardness values compared to the other mixing techniques at both 4 and 28 days (P < 0.0001). However, no significant difference existed between condensation and trituration techniques at both time intervals. Regardless of the mixing technique employed, a significant difference (P < 0.0001) was observed in surface microhardness value between all types of MTA apart from between Angelus grey and ProRoot white at both 4 and 28 days, both of which produced the highest values., Conclusion: Compared to trituration and condensation techniques, the application of ultrasonic energy to MTA produced a significantly higher surface microhardness value at both 4 and 28 days. Irrespective of mixing technique, ProRoot white and Angelus grey had the highest surface microhardness values. Trituration of encapsulated, premeasured MTA and water provides a standardiszed method of mixing that produces MTA slurries with more controllable handling characteristics.

In situ two-dimensional NMR and fluorescence emission spectroscopy were employed to investigate the cooperative structure-direction effect of organic amine such as morpholine in the synthesis of aluminophosphate molecular sieves in ionic liquids. In situ rotating frame nuclear Overhauser effect spectra (ROESY) together with fluorescence measurements demonstrate that the aggregates between imidazolium cations and morpholines through intermolecular hydrogen bonds can be formed in the gel during the crystallization of molecular sieves. Combining with the characterizations of the solid products by solid-state NMR, it is verified that different aggregates of organic amines with imidazolium cations, which is similar to self-assembled supramolecular analogues, could act as the structure-directing agents for selective tuning of the framework topologies such as AEL, AFI and LTA in the final solid products.

The aims of this study were to demonstrate the synthesis of an experimental glass ionomer cement (GIC) by the non-hydrolytic sol-gel method and to evaluate its biocompatibility in comparison to a conventional glass ionomer cement (Vidrion R). Four polyethylene tubes containing the tested cements were implanted in the dorsal region of 15 rats, as follows: GI - experimental GIC and GII - conventional GIC. The external tube walls was considered the control group (CG). The rats were sacrificed 7, 21 and 42 days after implant placement for histopathological analysis. A four-point (I-IV) scoring system was used to graduate the inflammatory reaction. Regarding the experimental GIC sintherization, thermogravimetric and x-ray diffraction analysis demonstrated vitreous material formation at 110oC by the sol-gel method. For biocompatibility test, results showed a moderate chronic inflammatory reaction for GI (III), severe for GII (IV) and mild for CG (II) at 7 days. After 21 days, GI presented a mild reaction (II); GII, moderate (III) and CG, mild (II). At 42 days, GI showed a mild/absent inflammatory reaction (II to I), similar to GII (II to I). CG presented absence of chronic inflammatory reaction (I). It was concluded that the experimental GIC presented mild/absent tissue reaction after 42 days, being biocompatible when tested in the connective tissue of rats.

Calcium aluminate phosphor co-doped Eu(2+), Dy(3+), Nd(3+) is prepared by the combustion method. We study systemically the influences of the quantity of mixed Dy(3+) ion, the quantity of flux H(3)BO(3), the differences in dispersing methods between magnetic stirring and ultrasonic dispersing and the combustion temperature on the long-persistence phosphor. The analytical results indicate that Dy(3+) ion improves the properties of the phosphors CaAl(2)O(4):Eu(2+), Nd(3+). The appropriate quantity of flux H(3)BO(3 )to( )reduce the forming temperature of the sample was determined. The monoclinic single phase of CaAl(2)O(4) formed at 500 degrees C and remained steady. The calcium aluminate co-doped Eu(2+), Dy(3+), Nd(3+) was synthesized by dispersal of the raw material using the ultrasonic method, and it had better optical properties., (Copyright (c) 2009 John Wiley & Sons, Ltd.)

Fluorescence spectroscopy and a range of computer simulation techniques are used to study the structure directing effect of benzylpyrrolidine (BP) and (S)-(-)-N-benzylpyrrolidine-2-methanol (BPM) in the synthesis of nanoporous aluminophosphate frameworks with AFI (one-dimensional channels) and SAO (three-dimensional interconnected channels) topologies. We study the supramolecular chemistry of BP and BPM molecules in aqueous solution and compare it with the aggregation state of the molecules found when they are inside the AlPO nanopores after crystallization. The aggregation of the molecules within the structures can be explained by a combination of thermodynamic and kinetic effects. The former are given by the stability of the molecular species interacting with the oxide networks relative to their stability in solution; the latter depend on the aggregation behavior of the molecules in the synthesis gels prior to crystallization. Whereas BPM only forms one type of aggregate in solution, which has the appropriate conformation to match the empty channels of the forming nanoporous frameworks, BP forms aggregates with different molecular orientations, of which only one matches the framework interstices. This different supramolecular chemistry, together with the higher interaction of BPM with the oxide networks, makes BPM a better structure directing agent (SDA); it is also responsible for the higher incorporation of BPM as dimers in the frameworks, especially in the AFI structure, observed experimentally. The concentration of the SDA molecules in the gels, and so the density per volume of the SDAs, determines the exclusion zone from which the pores and/or cavities of the framework will arise, and so the porous network of the formed material. A clear relationship between the SDA density in solution and in the framework is observed, thus enabling an eventual control of the material density by adjusting the SDA concentration in the gels. The topological instability intrinsic to these open framework structures is compensated by a high host-guest interaction energy; the SAO topology is further stabilized by doping with Zn. Our computational results account for and rationalize all the effects observed experimentally, providing a complete picture of the mode of structure direction of these aromatic molecules in the synthesis of nanoporous aluminophosphates.

Mg-Al-ascorbic acid (ASA)-layered double hydroxides (ASA-LDHs) with Mg/Al=3 were synthesized by ion-exchange, coprecipitation and reconstruction methods. Composites with sodium oleate (SOA)/ASA-LDH were prepared by an ion-exchange method using various concentrations of SOA solutions. The (003) basal spacing of the ASA-LDHs changed from 0.76nm in the CO(3)-LDH to 0.78 and 0.86nm after intercalation of the ASA ions and these basal spacings are in good agreement with models based on the assumption as mono layers and double layers of ASA ions in the LDH interlayers, respectively. The amounts of ASA in the LDHs prepared by the reconstruction method were higher than those by the ion-exchange and coprecipitation methods. In the preparation of composites of SOA/ASA-LDH, an ion-exchange method was more suitable than a reconstruction method to cause surface sorption of the SOA molecules with maintaining intercalated ASA ions in the LDH interlayers. The acid-resistant properties of the composites of SOA/ASA-LDH were found to be much higher than for the pure ASA-LDH and mixture of CO(3)-LDH and ASA. The surfaces of the LDH particles in the composites are, thus, mostly covered with sorbed SOA molecules and they are good candidates as drug delivery materials for intestines through the stomach.

AlPO(4)-5 and its chromium-containing analogue, CrAPO-5, were prepared using aluminum dross in the presence of triethylamine as a structure directing agent; both Al dross powder and an extracted precipitate from Al dross in an alkali solution were used as an aluminum source. These materials were characterized by XRD, BET surface area measurement, SEM, EDX, XRF, ESR, and UV-vis spectroscopy. Their textural properties were found close to those of the corresponding reference samples prepared using pure Al(OH)(3). CrAPO-5 samples prepared from the aluminum dross were tested as a catalyst for liquid phase oxidation of tetralin using t-butyl hydroperoxide as an oxidizing agent, which showed virtually identical catalytic performances to that obtained by a reference CrAPO-5 catalyst.

Introduction: Mineral trioxide aggregate (MTA) fulfills many of the ideal properties of a root end filling material and repair material for furcal perforation. However, its low cohesive property often makes it difficult to handle. To improve the handling properties of MTA root canal filling materials, MTA-like cement was made, and calcium lactate gluconate (CLG) aqueous solution was used to shorten the setting time and enhance the paste viscosity., Methods: CLG solution was prepared by mixing lactic acid, glucono delta lactone, and calcium oxide by wet process. The crystalline property of the CLG powder was characterized by x-ray diffraction. The MTA-like cements were prepared by mixing Portland cement/bismuth oxide/gypsum (75/20/5); ProRoot white MTA (Dentsply Tulsa Dental, Tulsa, OK) was used as a control group. The influence of various liquid phases on initial setting time, handling properties, and pH value were investigated by a Vicat needle, questionnaire of operational hand feel, and pH meter, respectively., Results: By using 23.1 wt% CLG solutions as a liquid phase, the setting time of white MTA was significantly decreased from 155.5 +/- 5.0 to 12.3 +/- 2.5 minutes. The pH values for hydrated white MTA with deionized water and 23.1 wt% CLG solutions were 12.29 +/- 0.02 and 11.81 +/- 0.04 at 72 hours., Conclusions: The results suggest that the addition of amorphous CLG-based liquid phase provides improvement in sealing ability as well as clinical manageability of dental filling materials.

Lithium aluminates (LiAlO(2) and Li(5)AlO(4)) were synthesized, characterized, and tested as possible CO(2) captors. LiAlO(2) did not seem to have good qualities for the CO(2) absorption. On the contrary, Li(5)AlO(4) showed excellent behavior as a possible CO(2) captor. Li(5)AlO(4) was thermally analyzed under a CO(2) flux dynamically and isothermically at different temperatures. These results clearly showed that Li(5)AlO(4) is able to absorb CO(2) in a wide temperature range (200-700 degrees C). Nevertheless, an important sintering effect was observed during the thermal treatment of the samples, which produced an atypical behavior during the CO(2) absorption at low temperatures. However, at high temperatures, once the lithium diffusion is activated, the sintering effect did not interfere with the CO(2) absorption. Eyring's model was used to determine the activation enthalpies of the CO(2) absorption (15.6 kJ/mol) and lithium diffusion (52.1 kJ/mol); the last one is the limiting process.

Natural kingite-like aluminophosphate nanorolls were obtained by biomimetic synthesis using a mixed-organoamine template.

A solid waste coming from the secondary aluminium industry was successfully vitrified in the ternary CaO-Al(2)O(3)-SiO(2) system at 1500 degrees C. This waste is a complex material which is considered hazardous because of its behaviour in the presence of water or moisture. In these conditions, the dust can generate gases such as H(2), NH(3), CH(4), H(2)S, along with heat and potential aluminothermy. Only silica sand and calcium carbonate were added as external raw materials to complete the glasses formula. Different nominal compositions of glasses, with Al(2)O(3) ranging between 20% and 54%, were studied to determine the glass forming area. The glasses obtained allow the immobilisation of up to 75% of waste in a multicomponent oxide system in which all the components of the waste are incorporated. The microhardness Hv values varied between 6.05 and 6.62GPa and the linear thermal expansion coefficient, alpha, varied between (62 and 139)x10(-7)K(-1). Several glasses showed a high hydrolytic resistance in deionised water at 98 degrees C.

Five aluminoborates Al[B(5)O(10)] x H(2)dab x 2 H(2)O (1), [Al(B(4)O(9))(BO)] x H(2)en (2), [Al(B(4)O(9))(BO)] x H(2)dap (3), K(2)Al[B(5)O(10)] x 4 H(2)O (4), and (NH(4))(2)Al[B(5)O(10)] x 4 H(2)O (5) have been synthesized under hydrothermal conditions and characterized by means of elemental analysis, IR, TG analysis, MAS NMR, UV-vis and fluorescence spectroscopy, powder X-ray diffraction, single-crystal X-ray diffraction, and NLO determination. The structure 1 comprises of AlO(4) tetrahedra and B(5)O(10) clusters and contains 12-, 11-, and 8-MR 3D-intersecting channels with a CrB(4) topological net. Structures 2 and 3 are both constructed from the same AlB(5)O(13) clusters and exhibit a six-connected framework with 4(12)6(3) topology. Structures 4 and 5 are isomorphous and are composed of AlO(4) tetrahedra and B(5)O(10) clusters that possess odd 11-MR channels and 8-MR helical channels. Structures 2-5 crystallized in an acentric structure and presented good SHG properties. UV-vis spectral investigation indicates that they are wide-band-gap semiconductors. The electronic structure calculations for the compounds also have been performed.

This study evaluated the influence of addition of 10% calcium chloride (CaCl(2)) on the setting time, solubility, disintegration, and pH of white MTA (WMTA) and white Portland cement (WPC). A test of the setting time was performed following the #57 ADA specifications and a test of the final setting time according to the ASTM. For the solubility tests disintegration and pH, Teflon rings were filled with the cements and weighed after setting. After 24 h in a desiccator, they were once again weighed. Thereafter, they were immersed in MiliQ water for 24 and 72 h and 7, 14, and 28 days, with maintenance in the desiccator and weighing between periods. The pH of water in which the rings were immersed was measured immediately after contact with them and in the other periods. The addition of CaCl(2) provided a significant reduction (50%) in the initial setting time of cements. The final setting time of WMTA was reduced in 35.5% and the final setting time of WPC in 68.5%. The WMTA with CaCl(2) absorbed water and gained weight with time, except for in the 24-h period. The addition of CaCl(2) to the WPC reduced its solubility. The addition of CaCl(2) increased the pH of WMTA in the immediate period and at 24 and 72 h and for WPC in the immediate period and at 24 h. The addition of CaCl(2) to WMTA and WPC reduced the setting times and solubility of both and increased the pH of cements in the initial periods.

Covalently bound organic silicate aluminum hybrid coagulants were synthesized by employing two silane coupling agents [diethoxydimethylsilane (DEDMS), gamma-aminopropylmethyldiethoxysilane (APDES)] as silicon sources. An additional coagulant was synthesized using anothersilane-tetraethylorthosilicate (TEOS) for comparison. Both the coagulant with DEDMS and that with APDES as the silicon source were shown to be covalently bound by infrared (IR) analysis. All three hybrid coagulants were characterized by pH, zeta potential, Al species distribution, and transmission electron microscopy (TEM) analysis. The results indicated that the silicon source played a significant role in aspects of the chemical and physical structure, Al species distribution, and electrochemistry characteristics. Specifically, the coagulant with APDES as the silicon source featured the highest zeta potential value, the highest content of Al13, and reticulated aggregate. The coagulation behaviors of the three hybrid coagulants were also investigated by treating synthetic water containing humic acid (HA). The hybrid coagulant with APDES as the silicon source exhibited the best coagulation behavior in terms of HA removal and turbidity removal, due to the combination of the zeta potential, Al species distribution, and organic functional groups.

The purpose of the study was to examine the physicochemical properties of mineral trioxide aggregate (MTA)-like cements prepared from SiO(2), CaO, and Al(2)O(3) as matrices, and ZnO, MgO, and Fe(2)O(3) as additives. The MTA-like cements showed a significantly (p < 0.05) faster setting time (<14 minutes) than MTA when mixed with water, although there was a significant decrease (p < 0.05) in diametral tensile strength, ranging from 0.9 to 3.1 MPa in comparison to MTA (4.4 MPa). The addition of ZnO, MgO, and Fe(2)O(3) to the MTA-like cement led to a significantly (p < 0.05) higher strength than MTA-like cement without additives. The pH values of the MTA-like cements were changed from an initial 11 to a high of 13, similar to the results of MTA. Future characterization of the examined MTA-like cement with shortened setting time is needed before it is considered a viable candidate for dental root-end-filling applications.

The high-resolution 27Al and 31P NMR spectra of two as-synthesized forms of the microporous aluminophosphate AlPO-14 and the corresponding calcined-dehydrated form were assigned using both "first-principles" calculations of NMR parameters (GIPAW, as implemented in NMR-CASTEP) and a 27Al-31P heteronuclear correlation NMR experiment (MQ-J-HETCOR) that exploits 27Al multiple-quantum coherences and J couplings to identify Al-O-P linkages. NMR parameters calculated from published AlPO-14 crystal structures, which are derived from powder X-ray diffraction (XRD) data, are in poor agreement with experiment and it was necessary to optimize the structure geometry using energy minimization before satisfactory agreement was obtained. Comparison of simulated powder XRD patterns from the experimental and the energy-minimized structures shows that the changes in relative atomic positions in the optimized structure are relatively small and yield only minor adjustments in the Bragg peak intensities. These results indicate that a combination of NMR spectroscopy and first-principles calculation of NMR parameters may soon be considered a generally useful step in the refinement of the structures of microporous materials derived from powder diffraction data.

A convenient method for the synthesis of 2-bromo-3-aroyl-benzo[b]furans from readily accessible precursors has been developed. The 2-bromo group has been employed as a versatile synthetic handle in both palladium-mediated couplings and direct nucleophilic substitutions to give access to a wide range of 2-substituted-3-aroyl-benzo[b]furans.