bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of the Addition of Calcium Hydroxide Powder on Some Physical and Chemical Properties of the Sealer MTA Fillapex
Authors: de Andrade Marcelo Ferrarezi , de Toledo Leonardo Renato , de Campos Edson Alves , Kuga Milton Carlos , Duarte Marco Antonio Hungaro , Keine Katia Cristina , Guiotti Flávia Angélica
Published: June 2012

Objective

This study evaluated the flow, pH and calcium release of MTA Fillapex (G1) or Fillapex plus 10% in weight of calcium hydroxide powder (G2), compared to AH Plus (G3) and Sealapex (G4).

Materials and methods

The flow test was performed according to ISO 6876:2001 requirements. The sealers were placed into plastic tubes and immersed in deionized water. After 24 hours, 7, 14 and 28 days, the water of each tube was removed and tested to evaluate the pH values and the level of released calcium. Calcium release values were analyzed statistically by Kruskal Wallis and Dunn tests and pH values analyzed by ANOVA and Tukey tests (α = 5%).

Results

G1 presented higher flow among all sealers. The addition of 10% calcium hydroxide into MTA Fillapex reduced the flow (p < 0.05) but, in a level, that is lower than the one recommended for ISO norms. G2 and G4 presented pH values and calcium release higher than G3 (p < 0.05) in all periods. G1 presented pH value higher than G3 (p < 0.05), except in 7 days period (p > 0.05). G4 presented higher pH values than G1 and G2, but the calcium release was similar for all periods (p > 0.05). G3 presented lower calcium release among all groups (p < 0.05).

Conclusion

The addition of 10% calcium hydroxide in MTA Fillapex caused reduction in flow and no negative interference in pH and/or calcium release. However, the obtained flow is different from ISO requirements.

Clinical relevance

MTA Fillapex presents levels of flow above the ISO norms. The addition of calcium hydroxide is a suggestion for solving this problem, but the impact of these procedures should be carefully evaluated.

How to cite this article

Keine KC, Guiotti FA, Leonardo RT, Kuga MC, Duarte MAH, de Campos EA, de Andrade MF. Influence of the Addition of Calcium Hydroxide Powder on Some Physical and Chemical Properties of the Sealer MTA Fillapex. World J Dent 2012;3(2):180-183.
Toothbrush Abrasion of Resin Composites with Different Filler Concepts
Authors: Kyoizumi Hideaki , Kanehira Masafumi , Finger Werner J , Araki Yasuyuki , Suzuki Toshimitsu
Published: June 2012

Purpose

To investigate the effect of tooth brushing wear with and without calcium carbonate slurry on four commercial resin composites based on different filler concepts.

Materials and methods

One nanofiller composite MI FIL (MFI, GC), one conventional hybrid type Venus (VEN) and two nanohybrid composites Venus Diamond (VED) and Venus Pearl (VEP) all from Heraeus Kulzer were examined. Forty beam-shaped specimens (12 × 3 × 3 mm) from each product were prepared and subdivided in two equal groups for pregrinding on SiC paper #600 and #4000 respectively. Ten specimens of each pre-ground group were subjected to toothbrush abrasion with calcium carbonate slurry, and 10 to toothbrushing with water only. The samples were submitted to five subsequent runs of 10,000 brushing strokes. Depth of wear and surface roughness (Ra) were measured with a profilometer after each 10 k strokes. Specimens after 50 k strokes were assessed by SEM. Additionally, the KHN (0.25 N/15 s) and the degree of conversion (DC) were determined. Data analysis was done by linear regression and ANOVA followed by Tukey's post-hoc test (p ≤ 0.05).

Results

Toothbrushing with abrasive slurry produced significantly different wear depths: VEN > MIF > VEP > VED. Linear relationships between depth of wear and number of cycles (r2 ≥ 0.94) were established for each material. Pregrinding with SiC #4000 resulted in less wear than pregrinding with #600. Ra figures were much higher for VED than for the other materials tested. MIF and VEN were uniformly abraded, whereas the largest glass fillers in VED protruded from the surroundings and the prepolymer particles in VEP were deeper abraded than the bulk of the material. Toothbrushing with water only revealed not measurable wear. Roughness Ra was practically unchanged when compared with the preground samples before challenging with toothbrushes. Ranking by KHN was: MIF < VEN, VEP < VED, by DC: MIF < VEN < VEP < VED.

Conclusion

Filler concepts and monomer compositions affect wear and roughness of resin composites when tooth brushed with abrasive slurry. Toothbrushing without abrasive medium produced neither wear nor roughness. Careful polishing of resin composite restorations is an important determinant of wear and surface roughness.

How to cite this article

Suzuki T, Kyoizumi H, Araki Y, Finger WJ, Kanehira M. Toothbrush Abrasion of Resin Composites with Different Filler Concepts. World J Dent 2012;3(2):184-193.
Smile Designing with Ceramic Veneers and Crowns
Authors: Abhilash PR , Divyashree R
Published: June 2012

Ceramic veneers and all-ceramic crowns can be offered as the treatment option in a wide variety of cases, such as correcting tooth defects, abrasion, malalignment, diastema, tooth discoloration, coronal fracture or to adjust occlusion. Minor changes of shape, shade and position of teeth with ceramic veneers can dramatically alter the appearance of our patients. This paper describes the esthetic rehabilitation and smile designing of three patients presenting with different problems with ceramic veneers and crowns.

How to cite this article

Divyashree R, Abhilash PR. Smile Designing with Ceramic Veneers and Crowns. World J Dent 2012;3(2):194-198.
Immunofluorescence in Oral Pathology—Part III: Pathology and Immunofluorescent Patterns in Intraepithelial Immunobullous Disorders
Authors: Premalatha BR , Juneja Saurabh , Rao Roopa S , Mysorekar Vijaya
Published: June 2012

Dermatologic disorders frequently parallel with oral involvement which dental practitioners should be familiar with. In continuation with part II, the immunofluorescence patterns in the intraepidermal pemphigus group and its variants: Pemphigus vulgaris (PV) and paraneoplastic pemphigus (PNP) are dealt in this section. Also, a brief note is added on other mucocutaneous disorders showing similar immunofluorescence patterns. The above listed immunobullous disorders are reviewed in detail with a summary of pathogenesis and characteristic histopathological findings. This review is to facilitate the clinicopathologist in the early diagnosis and subsequent treatment of these debilitating conditions.

How to cite this article

Rao RS, Premalatha BR, Mysorekar V, Juneja S. Immunofluorescence in Oral Pathology-Part III: Pathology and Immunofluorescent Patterns in Intraepithelial Immunobullous Disorders. World J Dent 2012;3(2):202-206.
Tooth-implant Connection: A Literature Review
Authors: Ghodsi Safoura , Rasaeipour Sasan
Published: June 2012

Aim

The aim of this review is to summarize and discuss the available information concerning the connection between the tooth and implant in a fixed partial denture.

Background

Although implant-supported prosthesis (ISP) has substantial biological and biomechanical advantages, due to the extensive use of implant in partially edentulous patients, encounter to cases of obligatory connection between the tooth and implant is not rare. However, because of their differences, especially in support mechanism, long-term prognosis of this treatment method is a special debate in dental literature.

Materials and methods

The literature published over the past 25 years was searched through PubMed, Medline, Google and indexed journals (search terms: tooth implant connection, tooth implant-supported fixed partial denture, tooth implant splinting, implant and tooth). The most valuable and relevant articles were selected and analyzed.

Results and discussion

The existing studies reveal that there are certain conditions in which this method is applicable. The main advantage of the method based on literature reviewed is reducing the need to the removable prosthesis in patients that otherwise require it. The disadvantages of this connection, mainly due to different movement range of components under loading, reportedly will be minimized if some guidelines are followed.

Clinical significance

According to available studies, this literature review supports tooth-implant connection technique where indicated, with complete attention to prudent guidelines. Further researches preferably concentrating on new methods and also long-term longitudinal studies are certainly needed before this approach can be widely used.

How to cite this article

Ghodsi S, Rasaeipour S. Tooth-implant Connection: A Literature Review. World J Dent 2012;3(2):213-219.
Localized Corrosion of Stainless Steel in a Nuclear Waste Cooling Water System—Part 4: Artificial Pit Investigation of Nitrate Inhibition
Authors: Whillock G.O.H. , Binks T.J. , Donohoe C.J.
Published: June 2012

A nuclear waste cooling water system, constructed from an austenitic stainless steel, is known to be susceptible to localized corrosion because of the combined presence of low concentrations of chloride (Cl−) ions in the water (<10 mg/L) and oxidants produced by water radiolysis. Corrosion propagates in the system as pitting corrosion, and inspections of accessible components indicated that large pit cavities could form. To investigate possible inhibition options, an artificial pit, termed the wire-electrode artificial pit, was developed and shown to be capable of sustaining corrosion under representative conditions. Tests carried out using this artificial pit to investigate the effect of sodium nitrate (NaNO3) added to the bulk water are reported here. The results showed that nitrate (NO3−) was capable of affecting inhibition at 60°C, although large concentrations and long times were required, e.g., inhibition took up to 20 days at 60,000 mg/L NO3−. Complimentary polarization tests were also carried out in a range of artificial pit solutions as a function of nitrate concentration to aid interpretation of the wire-electrode tests. The existence of a threshold molar NO3−/Cl− ratio for passivation to occur was identified but not clearly defined.
Role of Hydrogen in Stress Corrosion Cracking of X-60 Pipeline Steel in Soil Containing Water
Authors: Pan B.W. , Li J.X. , Su Y.J. , Chu W.Y. , Qiao L.J.
Published: June 2012

The role of hydrogen and anodic dissolution in stress corrosion cracking (SCC) of API X-60 pipeline steel in soil containing water has been studied. The results show that the relative elongation reduction induced by hydrogen, IHE, increases linearly with increases in the logarithm of hydrogen concentration, CH, i.e., IHE(%) = 27.9 + 11.5 lnCH(wppm). Hydrogen can enter the sample during SCC in soil containing water at open circuit and cathodic polarization. Therefore, the relative elongation reduction during SCC, ISCC, is the sum of ISCC(H), ISCC(AD), and ISCC(HAD), i.e., ISCC = ISCC(H) + ISCC(AD) + ISCC(HAD), where ISCC(H) is the relative elongation reduction induced by the hydrogen that entered the sample during SCC, ISCC(AD) is that induced by the anodic process during SCC, and ISCC(HAD) is that caused by the coupling of hydrogen and the anodic process in a hydrogen-enhanced anodic process. For SCC at open circuit, there is no hydrogen-enhanced anodic dissolution, and ISCC = ISCC(H) + ISCC(AD). Experiments showed that ISCC(H) ≈ ISCC(AD), indicating that hydrogen and anodic dissolution play almost equally important roles during SCC of pipeline steel in soil containing water at open circuit.
Use of Friction Stir Processing to Eliminate Sensitization in an Al-Mg Alloy
Authors: Reynolds A.P. , Chrisfield J.
Published: June 2012

Friction stir processing (FSP) was performed on 12.7 mm thick AA5083-H321 (UNS A95083) plates that had received a 14 day sensitization treatment at 100°C. Two FSP parameters were studied: 240 RPM, 2.5 mm·s−1 with a forge-force of 17.8 kN and 2,000 RPM, 38.1 mm·s−1 with a forge-force of 44.5 kN. Salt bath heat treatments of sensitized (14 days at 100°C) non-FSP specimens were performed to determine the temperature necessary for elimination of sensitization. For all cases, the level of sensitization was assessed by nitric acid mass-loss tests (NAMLT). NAMLT results showed that processing of sensitized plates reduced mass loss to levels consistent with resistance to intergranular (IG) corrosion. The improved NAMLT response occurred not only in the stirred region, but also extended through regions of the heat-affected zone, experiencing temperatures of greater than approximately 250°C. A minimum temperature of 250°C for improved NAMLT response was corroborated by temperature measurement in the plates made during FSP as well as salt bath heat treatments. These data were also consistent with the Al-Mg phase diagram.
Obtaining the kinetic function of depolymerization from evolving molecular weight distribution data–an inverse problem
Authors: Yeow Y. Leong , Guan Bifei , Wu Liang , Yap Tze‐Ming , Liow Jong‐Leng , Leong Yee‐Kwong
Published: June 2012

Depolymerization of macromolecules is generally regarded as a first order process with a kinetic function that depends on the molecular weights of the fragmenting molecule and fragmentation products. This article describes a computation scheme for obtaining the kinetic function from observed molecular weight distribution (MWD) data. The integro‐differential equation used by most investigators to compute MWD with some assumed kinetic function is reformulated as an inverse problem in which the kinetic function is treated as the unknown to be extracted from evolving MWD data. A numerical procedure based on two consecutive applications of Tikhonov regularization is developed to solve this inverse problem. It gives the kinetic function as the solution of a set of linear algebraic equations. Implementation of this procedure is described in full and its performance is assessed by applying it to simulated MWD data. A number of issues associated with discretization and regularization are discussed. © 2012 American Institute of Chemical Engineers AIChE J, 59: 912–922, 2013
Improving the mechanical properties of clay/polymer aerogels by a simple dip‐coating procedure
Authors: Johnson J. R. , Schiraldi D. A.
Published: June 2012

Clay aerogels have many advantages as one of the lowest density family of materials current technology can provide; they possess very low thermal conductivities, high porosities, and high surface areas. Although the mechanical properties of native clay aerogels are rather low, incorporating water‐dispersible polymers into the clay gel before they are processed into aerogel forms can easily produce more robust, low‐density composites. Various processing modifications and additives can be employed to strengthen the aerogel material, but currently, the materials have some notable weaknesses in abrasion resistance, water absorption, and flexural properties. In this study, we employed a low‐cost rubber coating material to quickly and efficiently address all three of these problems. After coating, the aerogels gained significant mechanical reinforcement, a 20‐fold increase in flexural modulus and a 15‐fold increase in yield stress, while exhibiting an increase of only 8% in the thermal conductivity. Improvements such as these can improve the commercial applicability of clay/polymer aerogels as thermal insulation materials. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Active learning: A small group histology laboratory exercise in a whole class setting utilizing virtual slides and peer education
Authors: Bloodgood Robert A.
Published: June 2012

Histology laboratory instruction is moving away from the sole use of the traditional combination of light microscopes and glass slides in favor of virtual microscopy and virtual slides. At the same time, medical curricula are changing so as to reduce scheduled time for basic science instruction as well as focusing on student‐centered learning approaches such as small group active learning and peer‐instruction. It is important that medical schools resist the temptation to respond to this conjunction of events by turning histology into a self‐study activity. This article describes a lymphoid histology laboratory exercise, occurring in a specially equipped Learning Studio housing an entire medical class that utilizes virtual slides in the context of small group active learning and peer instruction. Anat Sci Educ © 2012 American Association of Anatomists.
Biomarkers of the one‐carbon pathway in association with congenital diaphragmatic hernia
Authors: Beurskens Leonardus W.J.E. , de Jonge Robert , Schoonderwaldt Ernst M. , Tibboel Dick , Steegers‐Theunissen Régine P.M.
Published: June 2012

Homocysteine is an intermediate of the one‐carbon (1‐C) pathway and increased concentrations have been related to neural crest‐related congenital anomalies. The neural crest and the 1‐C pathway might be involved also in the etiology of Congenital Diaphragmatic Hernia (CDH). In 22 CDH and 28 control newborns and their mothers, general characteristics were obtained by standardized questionnaires. The 1‐C pathway intermediates total homocysteine (tHcy), S‐adenosylmethionine (SAM), and S‐adenosylhomocysteine (SAH) were determined in cord blood. Correlations between maternal and newborn factors and risk estimates were investigated by univariate and multivariable logistic regression analyses. Birth weight (2962 vs. 3418 gram; p < 0.001) was lower and gestational age (270 vs. 277 days; p = 0.006) was shorter in case children. Control mothers were slightly older (32 vs. 35 year; p = 0.05). Other characteristics were comparable between case and control children and mothers. The concentrations of homocysteine, SAM and SAH, and the SAM/SAH ratio were comparable (tHcy: 8.57 vs. 8.56 μmol/l, p = 0.99; SAM: 152.7 vs. 157.3 nmol/l, p = 0.76; SAH: 43.5 vs. 48.9, p = 0.26; ratio: 3.8 vs. 3.5, p = 0.50). Maternal and newborn characteristics were not correlated to the biomarker concentrations. In conclusion, the biomarkers of methylation determined in cord blood are not associated with CDH risk. Maternal and child characteristics could not predict newborn biomarker concentrations of the 1‐C pathway. Birth Defects Research (Part A) 2012. © 2012 Wiley Periodicals, Inc.
Sweet entanglements—protein: Glycan interactions in two HIV‐inactivating lectin families
Authors: Koharudin Leonardus M. I. , Gronenborn Angela M.
Published: June 2012

Structures and sugar binding by members of two lectin families, Cyanovirin‐N homolog (CVNH) and Oscillatoria Agardhii agglutinin homolog (OAAH), were determined to elucidate the basis for recognition of high‐mannose glycans on the HIV envelope glycoprotein gp120. We solved NMR solution and/or crystal structures for several lectins and delineated their carbohydrate specificity by array screening and direct NMR titrations. Both families recognize different epitopes on high‐mannose glycans, namely, Manα(1‐2)Man units at the end of the D1 and D3 arms and α3,α6‐mannopentaose at the central branch point of Man‐8 or Man‐9 for CVNH and OAAH lectins, respectively. © 2012 Wiley Periodicals, Inc. Biopolymers 99: 196–202, 2013.
Glycine betaine: A widely reported osmolyte induces differential and selective conformational stability and enhances aggregation in some proteins in the presence of surfactants
Authors: Misra Pinaki P. , Kishore Nand
Published: June 2012

In this study, we extensively report the effect of glycine betaine during the refolding of partially folded bovine α‐lactalbumin (α‐LA) in presence of hexadecyl trimethyl ammonium bromide (HTAB), and Ribonuclease A (RNAse A) in presence of sodium dodecyl sulfate (SDS) by different complementary biophysical, light scattering, and microscopic techniques. Though a substantial refolding/compaction was observed in both the studied proteins, the fluorescence studies contradicted the finding obtained from circular dichroism spectroscopy (CD) in case of α‐LA. CD stopped flow showed extensive presence of intermediates during the refolding of proteins which could potentially lead to aggregation. The aggregates as observed in dynamic light scattering (DLS), in α‐LA were massive as compared to RNAse A and was directly proportional to betaine concentration. The zeta potential confirmed that the aggregates are a direct manifestation of strong aggregating and/or immense preferential excluding tendency of GB and not because of charge neutralization; however a possible role of conformational change as observed in FTIR spectroscopy cannot be completely ruled out. In contrary though RNAse A showed a substantial refolding, the final state of the folded protein was significantly different from the native state. These findings for α‐LA and RNAse A were further supported by electron microscopic and thermodynamic studies. We thus propose that betaine has a strong macromolecular excluding tendency, primarily directed to shield the hydrophobic exposure either by refolding or aggregation, and depending on the hydrophobicity of the proteins, the functional restoration of the protein is manifested. © 2012 Wiley Periodicals, Inc. Biopolymers 97:933–949, 2012.
Unexpected high pressure effects on the structural properties of condensed whey protein systems
Authors: Dissanayake Muditha , Kasapis Stefan , Chaudhary Vinita , Adhikari Benu , Palmer Martin , Meurer Barbara
Published: June 2012

We show that application of high hydrostatic pressure (600 MPa for 15 min) on condensed whey protein (WP) systems (e.g., 80% w/w solids content) results in unexpected structure–function behavior when compared with conventional thermal treatment. Unraveling the relaxation properties in first‐order thermodynamic transitions, the manifestation of glass transition phenomena and the preservation of native conformation in condensed preparations were recorded using small‐deformation dynamic oscillation in shear, modulated differential scanning calorimetry, and infrared spectroscopy. Informed temperature application results in the formation of continuous networks at the denaturation temperature, which undergo vitrification at subzero temperatures. In contrast, high‐pressure‐treated WPs resist physicochemical denaturation, hence preserving the native conformation of secondary and tertiary structures. This was rationalized on the basis of a critical concentration threshold where transfer of water molecules to nonpolar residues in the protein interior is minimized because of low moisture content and restricted molecular mobility. The physical state and morphology of these high‐solid preparations were further examined by the combined framework of reduced variables and Williams, Landel, and Ferry equation/free volume theory. Theoretical treatment of experimental observations unveils the dynamic range of the mechanical manifestation of the glass transition region in samples subjected to heat or pressure. In addition to preserving native conformation, WPs subjected to high pressure form glassy systems at parity with the structural functionality of the thermally treated counterparts. © 2012 Wiley Periodicals, Inc. Biopolymers 97:963–973, 2012.
Influence of cartilage and menisci on the sagittal slope of the tibial plateaus
Authors: Cinotti Gianluca , Sessa Pasquale , Ragusa Giovanni , Ripani Francesca Romana , Postacchini Roberto , Masciangelo Raffaele , Giannicola Giuseppe
Published: June 2012

We analyzed the magnetic resonance studies of the knee in 80 subjects, 45 men and 35 women with a mean age of 38.9 years, who showed no pathological condition of the joint. Using an imaging visualization software, the sagittal longitudinal axis of the tibia was identified. The angle between this axis and a line tangent to the bone profile of the tibial plateau (bone slope) and to the superior border of the menisci (meniscal slope) were calculated. Thickness of anterior and posterior portion of menisci and underlying cartilage were also measured. The bone slope averaged 8° and 7.7° on the medial and lateral sides, respectively. The mean meniscal slope was 4.1° and 3.3° on the medial and lateral sides, respectively, with a significant difference compared with the bone slope. Menisci and underlying cartilage were significantly thicker in their posterior than their anterior portion (7.6 and 5.2 mm, respectively, in the medial compartment; 8.6 and 5.2 mm, respectively, in the lateral compartment). The presence of cartilage and menisci implies a significant decrease in the posterior tibial slope. In the lateral compartment, the greater the bone slope, the larger the difference between bone and meniscal slope, which means that a marked posterior tilt of the lateral tibial plateau is decreased by the cartilage and meniscus. These findings should be taken into account in planning surgical procedures which affect the slope of the articular tibial surface. Clin. Anat. 26:883–892, 2013. © 2012 Wiley Periodicals, Inc.
Prevalence of accessory pudendal artery
Authors: Allan R. , García N.A. , Montenegro J.M. , Álvarez‐Alberó J.N.M.
Published: June 2012

This study investigated the frequency of an accessory pudendal artery in 15 adult cadavers fixed with formaldehyde solution. The prevalence of accessory pudendal artery varies between 7 and 75% according to the method of identification (imaging studies, microstereoscopic cadaveric dissection, and open and laparoscopic surgeries). Currently, under discussion is the role of this artery in postprostatectomy erectile dysfunction. Accordingly, it is important to know the true prevalence to appreciate its clinical significance. The internal pudendal system was examined through direct dissection, and findings were compared with the different methods of identification published. Clin. Anat. 25:983–985, 2012. © 2012 Wiley Periodicals, Inc.
How to Control the Selectivity of Palladium‐based Catalysts in Hydrogenation Reactions: The Role of Subsurface Chemistry
Authors: Armbrüster Marc , Behrens Malte , Cinquini Fabrizio , Föttinger Karin , Grin Yuri , Haghofer Andreas , Klötzer Bernhard , Knop‐Gericke Axel , Lorenz Harald , Ota Antje , Penner Simon , Prinz Jan , Rameshan Christoph , Révay Zsolt , Rosenthal Dirk , Rupprechter Günther , Sautet Philippe , Schlögl Robert , Shao Lidong , Szentmiklósi László , Teschner Detre , Torres Daniel , Wagner Ronald , Widmer Roland , Wowsnick Gregor
Published: June 2012

Discussed are the recent experimental and theoretical results on palladium‐based catalysts for selective hydrogenation of alkynes obtained by a number of collaborating groups in a joint multi‐method and multi‐material approach. The critical modification of catalytically active Pd surfaces by incorporation of foreign species X into the sub‐surface of Pd metal was observed by in situ spectroscopy for X=H, C under hydrogenation conditions. Under certain conditions (low H2 partial pressure) alkyne fragmentation leads to formation of a PdC surface phase in the reactant gas feed. The insertion of C as a modifier species in the sub‐surface increases considerably the selectivity of alkyne semi‐hydrogenation over Pd‐based catalysts through the decoupling of bulk hydrogen from the outmost active surface layer. DFT calculations confirm that PdC hinders the diffusion of hydridic hydrogen. Its formation is dependent on the chemical potential of carbon (reactant partial pressure) and is suppressed when the hydrogen/alkyne pressure ratio is high, which leads to rather unselective hydrogenation over in situ formed bulk PdH. The beneficial effect of the modifier species X on the selectivity, however, is also present in intermetallic compounds with X=Ga. As a great advantage, such PdxGay catalysts show extended stability under in situ conditions. Metallurgical, clean samples were used to determine the intrinsic catalytic properties of PdGa and Pd3Ga7. For high performance catalysts, supported nanostructured intermetallic compounds are more preferable and partial reduction of Ga2O3, upon heating of Pd/Ga2O3 in hydrogen, was shown to lead to formation of PdGa intermetallic compounds at moderate temperatures. In this way, Pd5Ga2 and Pd2Ga are accessible in the form of supported nanoparticles, in thin film models, and realistic powder samples, respectively.
Label‐Free, Non‐Derivatization CRET Detection Platform for 6‐Mercaptopurine Based on the Distance‐Dependent Optical Properties of Gold Nanoparticles
Authors: Du Jianxiu , Wang Yadi , Zhang Weimin
Published: June 2012

A label‐free, non‐derivatization chemiluminescence resonance energy transfer (CRET) detection platform has been developed for the detection of the non‐fluorescent small molecule 6‐mercaptopurine. This CRET process arose from a chemiluminescent (CL) donor–acceptor system in which the reaction of bis(2,4,6‐trichlorophenyl)oxalate (TCPO)–H2O2–fluorescein (maximum emission at 521.6 nm) served as the donor and gold nanoparticles (AuNPs, maximum absorption at 520.0 nm) served as the acceptor. This process caused a significant decrease in the CL signal of the TCPO–H2O2–fluorescein reaction. The presence of 6‐mercaptopurine induced an aggregation of AuNPs with the assistance of Cu2+ ions through cooperative metal–ligand interactions that was accompanied by a distinct change in color and optical properties. The maximum absorption band of the AuNPs was red‐shifted to 721.0 nm and no longer overlapped with the CL spectrum of the reaction; as a result, the CL signal was restored. This CRET system exhibited a wide linear range, from 9.0 nmol L−1 to 18.0 μmol L−1, and a low detection limit (0.62 nmol L−1) for 6‐mercaptopurine. The applicability of the proposed CRET system was evaluated by analysis of 6‐mercaptopurine in spiked human plasma samples.
sp2‐Iminosugar O‐, S‐, and N‐Glycosides as Conformational Mimics of α‐Linked Disaccharides; Implications for Glycosidase Inhibition
Authors: Sánchez‐Fernández Elena M. , Rísquez‐Cuadro Rocío , Ortiz Mellet Carmen , García Fernández José M. , Nieto Pedro M. , Angulo Jesús
Published: June 2012

The synthesis of mimics of the α(1→6)‐ and α(1→4)‐linked disaccharides isomaltose and maltose featuring a bicyclic sp2‐iminosugar nonreducing moiety O‐, S‐, or N‐linked to a glucopyranoside residue is reported. The strong generalized anomeric effect operating in sp2‐iminosugars determines the α‐stereochemical outcome of the glycosylation reactions, independent of the presence or not of participating protecting groups and of the nature of the heteroatom. It also imparts chemical stability to the resulting aminoacetal, aminothioacetal, or gem‐diamine functionalities. All the three isomaltose mimics behave as potent and very selective inhibitors of isomaltase and maltase, two α‐glucosidases that bind the parent disaccharides either as substrate or inhibitor. In contrast, large differences in the inhibitory properties were observed among the maltose mimics, with the O‐linked derivative being a more potent inhibitor than the N‐linked analogue; the S‐linked pseudodisaccharide did not inhibit either of the two target enzymes. A comparative conformational analysis based on NMR and molecular modelling revealed remarkable differences in the flexibility about the glycosidic linkage as a function of the nature of the linking atom in this series. Thus, the N‐pseudodisaccharide is more rigid than the O‐linked derivative, which exhibits conformational properties very similar to those of the natural maltose. The analogous pseudothiomaltoside is much more flexible than the N‐ or O‐linked derivatives, and can access a broader area of the conformational space, which probably implies a strong entropic penalty upon binding to the enzymes. Together, the present results illustrate the importance of taking conformational aspects into consideration in the design of functional oligosaccharide mimetics.
A Journey inside the U28 Nanocapsule
Authors: Gil Adrià , Karhánek David , Miró Pere , Antonio Mark R. , Nyman May , Bo Carles
Published: June 2012

Anionic uranyl–peroxide U28 nanocapsules trap cations and other anions inside, whose structures cannot be resolved by X‐ray diffraction, owing to crystallographic disorder. DFT calculations enabled the complete characterization of the geometry of these complex systems and also explained the origin of the disorder. The stability of the capsules was strongly influenced by the entrapped cations. Excellent agreement between experiment and theory was also obtained for the electronic character and redox properties.
ChemInform Abstract: Magnetic Interactions in A‐Site‐Ordered Perovskites LnCu3(Ge3/4Ga1/4)4O12 (Ln: La, Dy).
Authors: Saito Takashi , Yamada Ryuta , Shimakawa Yuichi
Published: June 2012

The title compounds are prepared from stoichiometric mixtures of Dy2O3, CuO, GeO2, Ga2O3, and La2O3 (Pt capsules, 9 GPa, 1200 °C, 30 min).
ChemInform Abstract: Chrysanthemum‐Like Co3O4 Architectures: Hydrothermal Synthesis and Lithium Storage Performances.
Authors: Ren Manman , Yuan Shuming , Su Liwei , Zhou Zhen
Published: June 2012

Chrysanthemum‐like Co3O4 with nanorod assemblies is hydrothermally obtained from aqueous solutions of CoCl2 and urea (autoclave, 120 °C, 20 h, followed by calcination in air, 300 °C, 2 h).
ChemInform Abstract: Assembly of Molecular “Layered” Heteropolyoxometalate Architectures.
Authors: Gao Jing , Yan Jun , Beeg Sebastian , Long De‐Liang , Cronin Leroy
Published: June 2012

A new family of TeIV‐containing heteropolyoxometalate building blocks which consist of a {W3} top unit and one, two, and three layers of {TeW6} base units in [TeW9O33]8‐, [Te2W15O54]10‐, and [Te3W21O75]12‐, respectively, is synthesized.
ChemInform Abstract: Highly Enantioselective Copper‐Catalyzed Alkylation of β‐Ketoesters and Subsequent Cyclization to Spirolactones/Bi‐spirolactones.
Authors: Deng Qing‐Hai , Wadepohl Hubert , Gade Lutz H.
Published: June 2012

The copper(II)‐complex derived from the chiral bisoxazoline ligand BOI efficiently catalyzes the alkylation reaction.
ChemInform Abstract: Asymmetric Oxidation of Hetaryl Neomenthyl Sulfides.
Authors: Demakova M. Ya. , Sudarikov D. V. , Rubtsova S. A. , Slepukhin P. A. , Kutchin A. V.
Published: June 2012

Sulfides (I) are subjected to various oxidation systems to afford the corresponding stereoisomeric sulfoxides (II) and (III).
ChemInform Abstract: Highly Efficient Direct a Larger‐Scale Aldol Reactions Catalyzed by a Flexible Prolinamide Based‐Metal Lewis Acid Bifunctional Catalyst in the Presence of Water.
Authors: Chen Guodong , Fu Xiangkai , Li Chao , Wu Chuanlong , Miao Qiang
Published: June 2012

Direct aldol reaction of cyclic and acyclic ketones with aromatic aldehydes is efficiently catalyzed by a novel Zn—prolinamide‐based diamine complex in aqueous solution.
ChemInform Abstract: Luminescent Organogold(III) Complexes with Long‐Lived Triplet Excited States for Light‐Induced Oxidative C—H Bond Functionalization and Hydrogen Production.
Authors: To Wai‐Pong , Tong Glenna So‐Ming , Lu Wei , Ma Chensheng , Liu Jia , Chow Andy Lok‐Fung , Che Chi‐Ming
Published: June 2012

A novel gold complex is found to efficiently catalyze the oxidation of secondary amines (II) to imines and the oxidative cyanation of tertiary amines (III) under conditions A).
ChemInform Abstract: General Palladium‐Catalyzed Aerobic Dehydrogenation to Generate Double Bonds.
Authors: Gao Weiming , He Zhiqi , Qian Yong , Zhao Jing , Huang Yong
Published: June 2012

α,β‐Unsaturated aldehydes, ketones, esters, and azobenzenes are prepared from the corresponding saturated precursors under mild conditions using air or O2 as oxidant.
ChemInform Abstract: Air‐Stable, Nitrile‐Ligated (Cyclopentadienone)iron Dicarbonyl Compounds as Transfer Reduction and Oxidation Catalysts.
Authors: Plank Taylor N. , Drake Jessica L. , Kim Daniel K. , Funk Timothy W.
Published: June 2012

Five iron complexes of type (I) differing in the nitrile ligand are prepared and found to be active catalysts in the transfer reduction of acetophenone.
ChemInform Abstract: Chemoselective Ruthenium‐Catalyzed Reduction of Acid Chlorides to Aldehydes with Dimethylphenylsilane.
Authors: Gutsulyak Dmitry V. , Nikonov Georgii I.
Published: June 2012

The method works well for aromatic, heteroaromatic, and aliphatic acid chlorides.
ChemInform Abstract: NHC‐Catalyzed, Chemoselective Crossed‐Acyloin Reactions.
Authors: Rose Christopher A. , Gundala Sivaji , Fagan Claire‐Louise , Franz Johannes F. , Connon Stephen J. , Zeitler Kirsten
Published: June 2012

Triazolium salt TRB in combination with K2CO3 is an efficient catalyst for the coupling reaction of aliphatic or aromatic/heteroaromatic aldehydes with α‐ketoesters.
ChemInform Abstract: Monoallylation of 1,2‐Diols by Pd/Sn Bimetallic Catalysis.
Authors: Kuriyama Masami , Takeichi Tsubasa , Ito Masaaki , Yamasaki Noritsugu , Yamamura Ryota , Demizu Yosuke , Onomura Osamu
Published: June 2012

The selective monoallylation of 1,2‐diols occurs in the presence of a new bimetallic Pd/Sn catalyst system containing 1,4‐bis(diphenylphosphino)butane as ligand.
ChemInform Abstract: Amberlyst‐15 Catalyzed Cbz Protection of Amines under Solvent‐Free Conditions.
Authors: Bora Pranja P. , Vanlaldinpuia Khiangte , Rokhum Lalthazuala , Bez Ghanashyam
Published: June 2012

Amberlyst‐15 can effectively catalyze Cbz protection of aliphatic and aromatic amines at ambient temperature under solvent‐free conditions.
ChemInform Abstract: Indium‐Catalyzed Henry‐Type Reaction of Aldehydes with Bromonitroalkanes.
Authors: Soengas Raquel G. , Silva Artur M. S.
Published: June 2012

The economical method using zinc avoids the use of stoichiometric amounts of the expensive indium powder and can be easily scaled up.
ChemInform Abstract: Palladium‐Catalyzed Oxidative Arylating Carbocyclization of Allenynes.
Authors: Deng Youqian , Bartholomeyzik Teresa , Persson Andreas K. Aa. , Sun Junliang , Baeckvall Jan‐E.
Published: June 2012

An unprecedented Pd(II)‐catalyzed oxidative arylating and borylating carbocyclization of allenynes provides access to cyclic trienes and vinylallenes which are not accessible by other methods.
ChemInform Abstract: Preparation of (2,2‐Difluoroethenylidene)bis(tributylstannane) and Arylation Reaction: Efficient Approach to 1,1‐Diaryl‐2,2‐difluoroethenes.
Authors: Han Seung Yeon , Lee Hyo Young , Jeon Jong Hee , Jeong In Howa
Published: June 2012

The conditions for the synthesis of title reagent (III) are optimized.
ChemInform Abstract: Copper‐Catalyzed ipso‐Nitration of Iodoarenes, Bromoarenes and Heterocyclic Haloarenes under Ligand‐Free Conditions.
Authors: Joseph P. J. Amal , Priyadarshini S. , Kantam M. Lakshmi , Maheswaran H.
Published: June 2012

An excellent functional group tolerance and an extended substrate scope allow the synthesis of a broad spectrum of important nitroarene constituents under conditions A) or B) with complete regioselectivity.
ChemInform Abstract: Tandem Deuteration/Hydrosilylation Reactions Catalyzed by a Rhodium Carbene Complex under Solvent‐Free Conditions.
Authors: Egbert Jonathan D. , Nolan Steven P.
Published: June 2012

A Rh‐NHC‐complex is found to be effective for hydrosilylation of a series of ketones (Ia‐f), aldehydes (Ig,h) and imine (IV).
ChemInform Abstract: Aza‐Morita—Baylis—Hillman Reaction with Ion‐Supported Ph3P.
Authors: Imura Yumi , Shimojuh Naoya , Moriyama Katsuhiko , Togo Hideo
Published: June 2012

A recoverable and reusable catalyst can be used for the synthesis of the compounds (III) to give the yields in high purity (80‐97%) by simple Et2O extraction of the reaction mixture.
ChemInform Abstract: Synthesis of Pentafluoro‐λ6‐sulfanyl Substituted Acetylenes for Novel Liquid Crystals.
Authors: Ponomarenko Maxim V. , Kalinovich Nataliya , Serguchev Yurii A. , Bremer Matthias , Roeschenthaler Gerd‐Volker
Published: June 2012

Triethylborane‐mediated interaction of SF5Cl with alkynes (I) and subsequent dehydrochlorination of adducts (II) leads to the SF5‐substituted alkynes (III).
ChemInform Abstract: Multicomponent Reactions of β‐Ketosulfones and Formaldehyde in a Bio‐Based Binary Mixture Solvent System Composed of Meglumine and Gluconic Acid Aqueous Solution.
Authors: Yang Jie , Li Haoquan , Li Minghao , Peng Jiajian , Gu Yanlong
Published: June 2012

In the title solvent mixture, one‐pot, stepwise, multicomponent reactions of the ketosulfones with formaldehyde and a variety of nucleophiles such as thiols, arenes/heteroarenes, and styrenes are performed.
ChemInform Abstract: Bio‐Supported Palladium Nanoparticles as a Phosphine‐Free Catalyst for the Suzuki Reaction in Water.
Authors: Zhou Peipei , Wang Huanhuan , Yang Jiazhi , Tang Jian , Sun Dongping , Tang Weihua
Published: June 2012

Palladium nanoparticles, immobilized on bacterial cellulose, are successfully applied in the cross‐coupling of aryl iodides and chlorides with arylboronic acids [cf.
ChemInform Abstract: Practical Synthesis of Unsymmetric Diarylacetylenes from Propiolic Acid and Two Different Aryl Bromides.
Authors: Tartaggia Stefano , De Lucchi Ottorino , Goossen Lukas J.
Published: June 2012

The one‐pot sequential Sonogashira—decarboxylative coupling of propiolic acid (I) with two different aryl bromides is efficiently catalyzed by a Pd—SPhos catalytic system.
ChemInform Abstract: Aryl Ether as a Negishi Coupling Partner: An Approach for Constructing C—C Bonds under Mild Conditions.
Authors: Wang Chao , Ozaki Takashi , Takita Ryo , Uchiyama Masanobu
Published: June 2012

The nickel‐catalyzed cross‐coupling of naphthyl methyl ethers with freshly prepared dianion‐type aryl zincates can be performed at room temperature to give the corresponding biaryl compounds.
ChemInform Abstract: Polynuclear Copper(I) Complexes with Chelating Bis‐ and Tris‐N‐heterocyclic Carbene Ligands: Catalytic Activity in Nitrene and Carbene Transfer Reactions.
Authors: Tubaro Cristina , Biffis Andrea , Gava Riccardo , Scattolin Elena , Volpe Andrea , Basato Marino , Diaz‐Requejo M. Mar , Perez Pedro J.
Published: June 2012

The nitrene transfer reaction from N‐tosylimino(phenyl)iodinane (II) towards olefins (I), (IV) and from chloramine‐T (VII) towards cyclic ethers (VI) is catalyzed by dinuclear Cu—NHC complexes.
ChemInform Abstract: Cationic Rhodium(I)‐Catalyzed Regioselective Tandem Heterocyclization/[3 + 2] Cycloaddition of 2‐(1‐Alkynyl)‐2‐alken‐1‐ones with Alkynes.
Authors: Gao Hongyin , Zhang Junliang
Published: June 2012

The present new method to synthesize highly substituted cyclopenta[c]furans is applicable to different alkenylalkenones and a wide range of alkynes (III).
ChemInform Abstract: AgOTf as an Alternative Catalyst for the Regioselective Cyclization of 2‐(Alkynyl)benzyl Alcohols: Synthesis and Biological Evaluation of Phthalans.
Authors: Praveen Chandrasekaran , Iyyappan Chandran , Perumal Paramasivan T. , Girija K.
Published: June 2012

A variety of functionalized phthalans (II) (15 examples) is synthesized via AgOTf‐catalyzed regioselective cycloisomerization of 2‐(alkynyl)benzyl alcohols.
ChemInform Abstract: Copper(I) Iodide Catalyzed 3‐Sulfenylation of Indoles with Unsymmetric Benzothiazolyl‐Containing Disulfides at Room Temperature.
Authors: Ge Wenlei , Wei Yunyang
Published: June 2012

The simple method allows an efficient access to sulfurated indole derivatives of medicinal interest.
ChemInform Abstract: Intramolecular Fischer Indole Synthesis and Its Combination with an Aromatic [3,3]‐Sigmatropic Rearrangement for the Preparation of Tricyclic Benzo[cd]indoles.
Authors: Park In‐Keol , Park Jun , Cho Cheon‐Gyu
Published: June 2012

Aryl hydrazides containing a latent carbonyl group tethered to the para position of the aromatic ring undergo intramolecular Fischer indole formation.
ChemInform Abstract: Efficient Cyclic Carbonate Synthesis Catalyzed by Zinc Cluster Systems under Mild Conditions.
Authors: Yang Yi , Hayashi Yukiko , Fujii Yuka , Nagano Takuto , Kita Yusuke , Ohshima Takashi , Okuda Jun , Mashima Kazushi
Published: June 2012

The reaction of epoxides (I) with carbon dioxide is smoothly catalyzed by a tetranuclear zinc cluster—tetrabutylammonium iodide system to afford cyclic carbonates (III) in excellent yields.
ChemInform Abstract: Highly (Z)‐Selective Asymmetric Conjugate Addition of Alkynones with Pyrazol‐5‐ones Promoted by N,N′‐Dioxide—Metal Complexes.
Authors: Wang Zhen , Chen Zhenling , Bai Sha , Li Wei , Liu Xiaohua , Lin Lili , Feng Xiaoming
Published: June 2012

Optimized conditions allow the preparation of a broad spectrum of optically active adducts with (Z)‐configuration in high yields and with excellent e.e.
ChemInform Abstract: Catalyst‐Free Synthesis of Coumarin‐, Quinolone‐ and Pyridine‐Annulated Oxazole Derivatives.
Authors: Majumdar K. C. , Ganai Sintu , Nandi Raj Kumar , Ray Krishanu
Published: June 2012

A simple procedure is developed for the base‐mediated intramolecular cyclization of o‐bromoamide precursors to produce the title compounds.
ChemInform Abstract: Microwave‐Mediated Synthesis and Manipulation of a 2‐Substituted‐5‐aminooxazole‐4‐carbonitrile Library.
Authors: Spencer John , et al. et al.
Published: June 2012

Starting with the cyclocondensation of carboxylic acid chlorides with malononitrile derivative (II), the oxazole skeleton (III) is prepared which bears 2 functionalities for further derivatization.
ChemInform Abstract: Synthesis of Olefin‐Oxazoline Ligands (OlefOx) by Rhodium(III)‐Catalyzed Oxidative Olefination.
Authors: Schroeder Nils , Besset Tatiana , Glorius Frank
Published: June 2012

The highly modular synthesis of the ligands from 2‐aryloxazolines and a variety of vinyl derivatives can be performed under an atmosphere of air as terminal oxidant and a substoichiometric amount of Cu(OAc)2.
ChemInform Abstract: Copper‐Catalyzed Alkylation of Benzoxazoles with Secondary Alkyl Halides.
Authors: Ren Peng , Salihu Isuf , Scopelliti Rosario , Hu Xile
Published: June 2012

The copper complex (CUP) in combination with the diamine (DAE) efficiently promotes the reaction to produce 2‐substituted products.
ChemInform Abstract: Synthesis and Study of Oxadisilole‐Fused Benzisoxazoles or Naphthisoxazoles.
Authors: Ma Xuyan , Chen Yali , Zhang Yajuan , Xu Di , Cao Weiguo , Chen Jie
Published: June 2012

Reaction of oxadisilole‐fused arenes (I) and (VII) with phenyliodosoacetate and triflic acid followed by fluoride‐induced desilylation generates a benzyne intermediate which can be trapped by in situ generated nitrile oxides to give title benzisoxazoles (III) or naphthisoxazoles (VIII).
ChemInform Abstract: L‐Proline‐Catalyzed Synthesis of Novel 5‐(1H‐Indol‐3‐yl‐methylene)‐thiazolidine‐2,4‐dione Derivatives as Potential Antihyperglycemic Agents.
Authors: Riyaz S. , Naidu A. , Dubey P. K.
Published: June 2012

Symmetrically and unsymmetrically substituted title compounds are prepared under PTC conditions.
ChemInform Abstract: Convenient Synthesis of 2‐Arylbenzothiazoles and 2‐Arylnaphthothiazoles.
Authors: Zhang Li Fang , Ni Zhong Hai , Li Dong Ying , Qin Zhi Hong , Wei Xian Yong
Published: June 2012

Oxidation of methylarenes with elemental sulfur in the presence of aromatic amines gives the title compounds in moderate yields.
ChemInform Abstract: Synthesis of 2‐Aryl‐5‐(benzofuran‐2‐yl)thiazolo[3,2‐b][1,2,4]triazoles Using Green Procedures and Their Antibacterial Activity.
Authors: Jakhar Komal , Makrandi J. K.
Published: June 2012

The title compounds (IV) show strong activity against Gram‐negative bacteria.
ChemInform Abstract: Synthesis of 5‐Oxo‐1‐substituted Tetrazoles Derived from Amino Acids.
Authors: Nagendra G. , Narendra N. , Sureshbabu Vommina V.
Published: June 2012

A simple and efficient protocol for the synthesis of tetrazolone derivatives of N‐protected β‐amino acids includes [3 + 2] cycloaddition reactions of amino acid derived isocyanates with Tms—N3.
ChemInform Abstract: Efficient One‐Pot Synthesis of 4‐Aroyl‐2‐pyrones: Nucleophilic Addition of Active Methylene Groups to 1,2‐Diaroylacetylenes.
Authors: Shankar Ravi , Shukla Harsha , Singh Uma Sharan , Thakur Vinay , Hajela K.
Published: June 2012

An efficient one‐pot synthesis of 3,6‐disubstituted‐4‐aroyl‐2‐pyrones of type (III) proceeds through Michael reaction of active methylene compounds with 1,2‐diaroylacetylenes in the presence of NaH in DMSO at room temperature.
ChemInform Abstract: Enantioselective [4 + 2] Cycloadditions of 2‐Vinyl‐1H‐indoles with 3‐Nitro‐2H‐chromenes Catalyzed by a Zn(OTf)2/Bis(oxazoline) Complex: An Efficient Approach to Fused Heterocycles with a Quaternary Stereocenter.
Authors: Tan Fen , Xiao Cong , Cheng Hong‐Gang , Wu Wei , Ding Ke‐Rong , Xiao Wen‐Jing
Published: June 2012

A variety of fused heterocycles is synthesized with high yields, excellent diastereoselectivities and mostly high enantioselectivities except for nitropyran (VI).