bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of stable luminescent poly(methyl methacrylate)–europium complex nanospheres and application in the detection of hydrogen peroxide with the biocatalytic growth of gold nanoparticles
Authors: Li Zhanjun , Zhang Hongwu , Shen Jiangshan
Published: July 2012

A simple and effective solvent swelling method was developed for the preparation of poly(methyl methacrylate) (PMMA)/europium (Eu) complex hybrid nanospheres. Transmission electron microscopy and dynamic light scattering results indicate that the as‐prepared PMMA–Eu nanoparticles had a spherical morphology, with a narrow particle size distribution ranging from 100–200 nm. The PMMA–Eu nanospheres exhibited strong red emissions with a maximum peak at 612 nm under UV excitation, and the luminescence lifetime of the Eu complex was enhanced after it was swollen into PMMA nanospheres. Furthermore, the luminescence intensity of the PMMA–Eu nanospheres was very stable in various severe media, including aqueous solutions with various pHs, 1 mM Ca2+, 1 mM Fe2+, 1 mM Cu2+, 0.1M phosphate‐buffered saline solution, 1 mM citric acid solution, 1 mM lysine, and 1 mM glutamic acid. After the nanospheres were incubated at various temperatures for 1 h, the luminescence properties remained stable when the temperature was less than 40°C yet decreased slightly between 40 and 60°C and decreased rapidly at higher temperatures. These luminescent nanospheres were successfully applied in the luminescence‐sensing assay of hydrogen peroxide and exhibited a high sensitivity and broad linear concentration range. Because of their unique luminescence properties, the as‐synthesized PMMA–Eu nanospheres are expected to have great potential for use as luminescent labels or probes for long‐time imaging and analysis in which severe media situations are present. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis of triphenyl phosphine oxide‐containing polymers via atom transfer radical polymerization
Authors: Türel Betül , Karataş Sevim , Güngör Atilla , Serhatli I. Ersin
Published: July 2012

Bis[(4 ‐β‐(2‐bromopropanoate)ethoxy)phenyl]phenylphosphine oxide was used for the first time as the initiator of atom transfer radical polymerization of styrene and methyl methacrylate in the presence of CuBr/N, N,N′, N″, N″‐pentamethyldiethylenetriamine as catalyst/ligand and dimethyl sulfoxide as solvent. The presence of phosphine oxide linkages in the backbone gives the polymers special properties; low Tg, high char yield, and decreases the oxygen induction time value. A linear increase of number average molecular weight (Mn) versus monomer conversion was observed, and the molecular weight distribution was relatively narrow (Mw/Mn = 1.1–1.3). FTIR, 1HNMR, gel permeation chromatography, ultraviolet spectroscopies were used for the characterization of the related polymers. The thermal properties of these polymers were investigated by differential scanning calorimetry and thermogravimetric analysis. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
The Localization of the Supraorbital Notch or Foramen is Crucial for Headache and Supraorbital Neuralgia Avoiding and Treatment
Authors: Tomaszewska Agnieszka , Kwiatkowska Barbara , Jankauskas Rimantas
Published: July 2012

The aim of this study was to provide the morphological and morphometric data of the supraorbital foramina or notches related to sex, side, and the climatic conditions where the population lived. It was hypothesized that the distribution of the occurrence and location of these openings depends on climatic conditions in which the population lived. Orbits from 866 dried skulls obtained from three climatic regions: warm, temperate, and cold were examined. The examination concentrated on the configuration (notch/foramen) and on the distances to the reference points: nasion, frontomalare orbitale, infraorbital foramen and the superior orbital rim. In 14.3% of cases a smooth supraorbital rim was observed while different variants of the structures were observed in 85.7% of the cases. In cold climatic conditions, supraorbital foramina were found in the highest frequency (35.4%). In warm and temperate climates, the observed frequencies of supraorbital foramen were the lowest (18.8% and 19.9%, respectively). Frequency of supraorbital notches was the lowest of those skulls from a cold climate (44.0%) and the highest in those from a warm climate (59.0%). These results support the hypothesis that the occurrence of the supraorbital notches is greater in populations from warm compared with cold regions. This would provide a greater exit route for the neurovascular bundle and this may be related to the thermoregulatory processes in the supraorbital region. Furthermore, knowledge of precise locations of supraorbital structures is important when a supraorbital nerve block is given, for example, in the treatment of migraine headaches. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
A DIGESTIVE LIPASE OF Pieris brassicae L. (LEPIDOPTERA: PIERIDAE): PURIFICATION, CHARACTERIZATION, AND HOST PLANTS EFFECTS
Authors: Zibaee Arash
Published: July 2012

The properties of a digestive lipase from the larval midgut of Pieris brassicae were studied by performing biochemical purification, characterization, effect of host plants, and extracted inhibitors. The purification process revealed a lipase with a purification fold of 42, recovery of 18.12%, molecular weight mass of 72.3 kDa, optimal pH at 11, and optimal temperature at 30°C, as well as stability at the optimal temperature for 12 h. The purified enzyme was inhibited by the ions Na+, Mn+, Fe2+, and Cu2+ and the inhibitors SDS, EDTA, TTHA, and mercaptoethanol. Ca2+ and Mg2+ increased activity of the purified lipase, but urea, PMSF, EGTA, and DTC had no effect on enzymatic activity. Feeding of larvae on three host plants, Trepaeolus majus, Brassica olearcea var. alba, and B. olearcea var. rubra revealed the highest lipase activity on T. majus, but the two varieties of B. olearcea significantly decreased lipase activity. Extraction of a crude inhibitor from two varieties of B. olearcea demonstrated that the crude inhibitor inhibited the purified lipase up to 75%. The inhibitor changed the kinetic parameters of the enzyme by elevating the Km, as in competitive inhibition. The data suggest a possible role for plant lipase inhibitors in host plant resistance.
Oral apremilast in the treatment of active psoriatic arthritis: Results of a multicenter, randomized, double‐blind, placebo‐controlled study
Authors: Schett Georg , Wollenhaupt Jurgen , Papp Kim , Joos Rik , Rodrigues Jude F. , Vessey Adele R. , Hu ChiaChi , Stevens Randall , de Vlam Kurt L.
Published: July 2012

Objective

To evaluate the efficacy and safety of apremilast, a novel, orally available small molecule that specifically targets phosphodiesterase 4, in the treatment of active psoriatic arthritis (PsA).

Methods

This phase II, multicenter, randomized, double‐blind, placebo‐controlled study included the following: a 12‐week treatment phase, with patients receiving placebo, apremilast 20 mg twice per day, or apremilast 40 mg once per day; a 12‐week treatment‐extension phase, with patients in the placebo group re‐randomized to receive apremilast; and a 4‐week observational phase after treatment cessation. The primary end point was the proportion of patients achieving the American College of Rheumatology criteria for 20% improvement (ACR20) at week 12. Safety assessments included adverse events (AEs), physical examinations, vital signs, laboratory parameters, and electrocardiograms.

Results

Of the 204 patients with PsA who were randomized to a treatment group, 165 completed the treatment phase. At the end of the treatment phase (week 12), 43.5% of patients receiving apremilast 20 mg twice per day (P < 0.001) and 35.8% of those receiving 40 mg once per day (P = 0.002) achieved an ACR20 response, compared with 11.8% of those receiving placebo. At the end of the treatment‐extension phase (week 24), >40% of patients in each group (patients receiving apremilast 20 mg twice per day, patients receiving apremilast 40 mg once per day, and patients in the placebo group re‐randomized to receive apremilast) achieved the ACR20 level of improvement. Most patients in the treatment phase (84.3%) and treatment‐extension phase (68.3%) reported ≥1 AE. Diarrhea, headache, nausea, fatigue, and nasopharyngitis were reported most frequently; most events were mild or moderate. No clinically relevant laboratory or electrocardiographic abnormalities were reported.

Conclusion

Treatment with apremilast at a dosage of 20 mg twice per day or 40 mg once per day demonstrated efficacy in comparison with placebo and was generally well tolerated in patients with active PsA. The balance of efficacy, tolerability, and safety supports further study of apremilast in PsA.
Towards a Zinc‐Catalyzed Asymmetric Hydrogenation/Transfer Hydrogenation of Imines
Authors: Werkmeister Svenja , Fleischer Steffen , Junge Kathrin , Beller Matthias
Published: July 2012

The first asymmetric hydrogenation/transfer hydrogenation of imines to amines using zinc(II) triflate in combination with chiral ligands is described. The monodentate binaphthophosphepine ligand (3g) provided the highest enantioselectivities. Using different imines, the corresponding amines were obtained in moderate yields and enantioselectivities.
Total Synthesis of Ceratopicanol through Tandem Cycloaddition Reaction of a Linear Substrate
Authors: Lee Sang‐Shin , Kim Won‐Yeob , Lee Hee‐Yoon
Published: July 2012

Total synthesis of ceratopicanol (1) was achieved with a tandem cycloaddition reaction of allenyl diazo compound 6 via a trimethylenemethane (TMM) diyl intermediate. The TMM diyl mediated [2+3] cycloaddition reaction furnished the consecutive quaternary carbon centers and showed an unusual diastereoselectivity.
Novel Adaptive Control Design for Nonlinear System with Extended Partition of Unity Method
Authors: Luo Liang , Wang Yin‐He , Fan Yong‐Qing , Zhang Yun
Published: July 2012

One of the amazing abilities of fuzzy logic systems or neural networks is their ability to approximate unknown certainties. When nonlinear systems possess multiple variables, however, the process of the adaptive fuzzy or neural network online control becomes difficult. In this paper, we will introduce the extended partition of unity (EPU), composed of scalars and saturators, to address this problem. The merit of the suggested design scheme is that the construction of the partition of unity and the design of adaptive laws are separate. This means the proposed design method only adjusts the outputs of EPU and one update law, even in nonlinear systems with multiple variables. Therefore, this new method of EPU leads to easier selection of basis functions, reduces the number of adaptive laws, has greater robustness, and is suitable for different kinds of universal approximators. Finally, a numerical example is given to illustrate the effectiveness of the approach.
Validation of NARCCAP temperature data for some forest sites in the southeast United States
Authors: Shem Willis Otieno , Mote T. L. , Shepherd J. M.
Published: July 2012

Validation of North American Regional Climate Change Assessment Program (NARCCAP) climate simulations is conducted for selected US Forest Service sites in the southeastern United States. Results focus on qualitative and quantitative comparisons of seasonal and monthly temperature data from NARCCAP simulations to the surface air temperature data sets developed at the University of Delaware. The Regional Climate Model, RCM3, driven by the Geophysical Fluid Dynamics Laboratory Global Climate Model underestimates average surface temperature for some areas of the southeast United States by about 4 °C for the daily average during the winter of the selected period. Copyright © 2012 Royal Meteorological Society
Stochastic ordering properties for systems with dependent identically distributed components
Authors: Navarro Jorge , del Águila Yolanda , Sordo Miguel A. , Suárez‐Llorens Alfonso
Published: July 2012

In this paper, we obtain ordering properties for coherent systems with possibly dependent identically distributed components. These results are based on a representation of the system reliability function as a distorted function of the common component reliability function. So, the results included in this paper can also be applied to general distorted distributions. The main advantage of these results is that they are distribution‐free with respect to the common component distribution. Moreover, they can be applied to systems with component lifetimes having a non‐exchangeable joint distribution. Copyright © 2012 John Wiley & Sons, Ltd.
The heterogeneous reaction of N2O5 with HBr on Ice comparison with N2O5+HCl
Authors: Seisel Sabine , Flückiger Benoit , Rossi Michel J.
Published: July 2012

The heterogeneous reactions of N2O5 with HCl and HBr on ice have been studied in the temperature range 180 to 200 K using a Knudsen flow reactor.

The uptake of N2O5 on ice in the presence of HBr was found to be strongly dependent on the HBr concentration. For the highest HBr concentrations used a maximum uptake coefficient of N2O5 of γ=0.11 has been determined. We observed Br2 and HONO in 80% yield as products with respect to N2O5 taken up. The uptake coefficient of N2O5 on ice in the presence of HCl was found to be 3.2·10−2 and increased with increasing HCl concentration. CINO2 was detected as the sole reaction product with a maximum yield of 63% with respect to N2O5 consumed.

Hydrolysis of N2O5 resulting in HNO3 was found to be competitive with the title reaction. For the case of the HBr reaction the branching ratio between Br2 and HONO formation, on the one hand, and hydrolysis of N2O5, on the other hand, has been determined. Mechanistic aspects of the heterogeneous reaction of N2O5 with HX have been discussed.
Calculation of the first and second stoichiometric dissociation constants of glycine in aqueous sodium chloride solutions at 298.15 K
Authors: Partanen Jaakko I.
Published: July 2012

Equations for the calculation of the first and second stoichiometric dissociation constants (Km,1 and Km,2) of glycine in aqueous NaCl solutions at 298.15 K were determined by a method developed recently. In this method, a simple equation of the Hückel type is used for single‐ion activity coefficients. The thermodynamic dissociation constants of this amino acid were taken from the literature, and the parameters for the activity coefficient equation were determined from the electromotive force data measured on cells without a liquid junction. These data were taken from the literature, and they were also used to test the resulting equations. The equations predict the data usually within ±0.3 mV. The recommended activity coefficients equations were also tested with literature results measured on cells containing a liquid junction. The activity coefficient equations apply in the best case up to ionic strengths of about 3 mol kg−1. For the glycine solutions where NaCl alone determines the ionic strength, the recommended Km,1 and Km,2 are tabulated at rounded ionic strengths. Possibilities to calculate the ionic activity coefficients for glycine species by means of the Pitzer equations are also considered.
Evaluation of pharmacokinetic differences of acetaminophen in pseudo germ‐free rats
Authors: Lee Soo Hyun , An Ji Hye , Lee Hwa Jeong , Jung Byung Hwa
Published: July 2012

To evaluate the metabolic interaction between host and gut microflora on drug metabolism, pseudo germ‐free rats were prepared with an antibiotics cocktail to change their gut conditions. The usefulness of the pseudo germ‐free model was evaluated for observing the DMPK of acetaminophen (APAP). Pseudo germ‐free rats were prepared by orally administering antibiotic cocktails consisting of bacitracin, streptomycin and neomycin, and then APAP was orally administered to control and pseudo germ‐free rats. The plasma concentration of APAP and its six metabolites were quantified using a validated LC‐MS/MS method. A non‐compartment model estimated the pharmacokinetic parameters of APAP and its metabolites, and the ratios of the area under curve (AUC; AUCmetabolite/AUCAPAP) were also observed to evaluate the change of APAP metabolism. The AUCs of APAP and APAP‐Glth (glutathione) were higher and the AUCAPAP‐Sul/AUCAPAP (metabolic efficiency of sulfate conjugation) was lower in pseudo germ‐free rats than those in the control rats. The decrease in metabolic efficiency of sulphate conjugation could result from the reduction of the sulphate supply, causing an increase of the AUC of APAP and APAP‐Glth. The activities of gut microflora can affect the state of hepatic sulphate for drug conjugation, indirectly leading to characteristic APAP metabolism. These results indicate that gut microflora may play an important role in the pharmacokinetics and metabolism of APAP. Thus, the metabolic interaction between host and gut microflora should be considered upon drug administration and pseudo germ‐free rats prepared in the present study can be competent for investigating the metabolic interaction between host and gut microflora on drug metabolism. Copyright © 2012 John Wiley & Sons, Ltd.
Is there an embryopathy associated with first‐trimester exposure to angiotensin‐converting enzyme inhibitors and angiotensin receptor antagonists? A critical review of the evidence
Authors: Polifka Janine E.
Published: July 2012

Drugs that interfere with the renin‐angiotensin system, such as angiotensin‐converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), are widely used to manage hypertension and heart failure. Adequate functioning of the RAS is essential for normal fetal kidney development. The potential for ACEIs and ARBs to impair fetal and neonatal renal function if taken after the first trimester of pregnancy has been well documented. Although these drugs were not found to be teratogenic in animals, until recently little was known about the teratogenic effects of ACEIs and ARBs in humans when exposure was limited to the first trimester of pregnancy. New evidence from epidemiologic studies indicates that there may be an elevated teratogenic risk when these drugs are taken during the first trimester of pregnancy. However, this elevated risk does not appear to be specific to ACEIs and ARBs, but is instead related to maternal factors and diseases that typically coexist with hypertension in pregnancy, such as diabetes, advanced maternal age, and obesity. Women who become pregnant while being treated with an ACEI or ARB should be advised to avoid exposure to these drugs during the second and third trimesters of pregnancy by switching to a different class of antihypertensive drugs between weeks 8 and 10 after conception. Birth Defects Research (Part A) 94:576–598, 2012. © 2012 Wiley Periodicals, Inc.
A critical assessment of the h‐index
Authors: Gaster Natascha , Gaster Michael
Published: July 2012

Editor's suggested further reading in BioEssays: Can we do better than existing author citation metrics? Abstract and Counting citations in texts rather than reference lists to improve the accuracy of assessing scientific contribution Abstract
Characteristics of START Assessments Completed in Mental Health Jail Diversion Programs
Authors: Desmarais Sarah L. , Van Dorn Richard A. , Telford Robin P. , Petrila John , Coffey Tim
Published: July 2012

Many different instruments have been developed to assist in the assessment of risk for violence and other criminal behavior. However, there is limited evidence regarding how these instruments work in the ‘real world’. Even less is known about how these instruments might work for assessing risk in jail diversion populations, whether in research or practice. To address these knowledge gaps, the present study examined the characteristics of risk assessments completed by program staff (n = 10) on 96 mental health jail diversion clients (72 men and 24 women) using the Short‐Term Assessment of Risk and Treatability (START). The findings provide preliminary support for the reliability and validity of START assessments completed in jail diversion programs, the first evidence of the transportability of START outside psychiatric settings, and further evidence regarding the reliability and validity of START assessments completed in the field. They additionally support the consideration of an eighth, general offending risk domain in START assessments. Copyright © 2012 John Wiley & Sons, Ltd.
Macroscopic and microscopic features of the mandibular condyle in autopsied elderly individuals
Authors: Nakai Mitsuyoshi , Abe Masato , Miyazaki Akihiro , Fujimiya Mineko , Hiratsuka Hiroyoshi
Published: July 2012

Many studies have attempted to classify the macroscopic shapes of the mandibular condyle in humans; however, no consensus has yet been reached because the shapes vary. One problem is that classification of macroscopic morphological changes of the condylar surface has been largely based on bones from ancient people, with few bones from modern people covering many different age groups. In this study, 144 condyles from 78 cadavers (40 men, 38 women; age at death: >70 years) were investigated. The macroscopic shapes of the condyles were classified from posterior and lateral views into four types: convex, flattened, angled, and irregular. Of the 144 condyles, 25 were investigated microscopically. On macroscopic examination, in both posterior and lateral views, convex‐type condyles were most frequently observed. Most posterior convex‐type condyles were also categorized as the lateral convex type. On histological examination, we observed an increase in cartilage cells (7 condyles, 28%), a decrease in cartilage cells (3 condyles, 12%). Increases in cartilage cells were seen only in angled and irregular types (P = 0.001), whereas decreases in cartilage cells were only observed in the flattened type (P = 0.01). A convex macroscopic form appears to be standard for human mandibular condyles, even in the elderly. The histological findings suggest that mandibular condyles tend to not only undergo flattening, but also undergo progressive changes toward protrusion with age due to increased numbers of cartilage cells. In other words, this study suggests that there is potential for progressive alterations in mandibular condyles in the elderly. Clin. Anat. 27:399–407, 2014. © 2012 Wiley Periodicals, Inc.
Mushroom Tyrosinase Oxidizes Tyrosine‐Rich Sequences to Allow Selective Protein Functionalization
Authors: Long Marcus J. C. , Hedstrom Lizbeth
Published: July 2012

We show that mushroom tyrosinase catalyzes the formation of reactive o‐quinones on unstructured, tyrosine‐rich sequences such as hemagglutinin (HA) tags (YPYDVPDYA). In the absence of exogenous nucleophiles and at low protein concentrations, the o‐quinone decomposes with fragmentation of the HA tag. At higher protein concentrations (>5 mg mL−1), crosslinking is observed. Besthorn's reagent intercepts the o‐quinone to give a characteristic pink complex that can be observed directly on a denaturing SDS‐PAGE gel. Similar labeled species can be formed by using other nucleophiles such as Cy5‐hydrazide. These reactions are selective for proteins bearing HA and other unstructured poly‐tyrosine‐containing tags and can be performed in lysates to create specifically tagged proteins.
Methods in Molecular Biology 795: Kinase Inhibitors: Methods and Protocols. Edited by Bernhard Kuster.
Authors: Laufer Stephan , Bauer Silke
Published: July 2012

Humana Press, Totowa 2011, XI+256 pp., hardcover $ 119.00.—ISBN 978‐1‐61779‐336‐3
Ruthenium(IV)–Bis(methallyl) Complexes as UV‐Latent Initiators for Ring‐Opening Metathesis Polymerization
Authors: Wang Dongren , Unold Jörg , Bubrin Martina , Frey Wolfgang , Kaim Wolfgang , Buchmeiser Michael R.
Published: July 2012

The RuIV‐based transition metal catalysts [Ru(η3:η3‐C10H16)Cl2(PPh3)] (1), [Ru(η3:η3‐C10H16)Cl2(PCy3)] (2), and [Ru(η3:η3‐C10H16)(CF3COO)2(PPh3)] (3) have been synthesized and investigated for their use as initiators in the thermally and photo‐initiated ring‐opening metathesis polymerization (photo‐ROMP) of norborn‐2‐ene (NBE). Compounds 1 and 3 display significant photo‐ROMP activity with NBE whereas compound 2, although active in the ROMP of NBE, shows virtually no latency at all. The results are discussed with respect to the structural features of the novel catalysts.
Ordered Mesoporous Carbon Supported Colloidal Pd Nanoparticle Based Model Catalysts for Suzuki Coupling Reactions: Impact of Organic Capping Agents
Authors: Choi Ha Rim , Woo Hyunje , Jang Seongwan , Cheon Jae Young , Kim Chungho , Park Jongnam , Park Kang Hyun , Joo Sang Hoon
Published: July 2012

Recent advances in the field of nanoscience have enabled the preparation of high‐surface‐area supported catalysts with precise control over the individual structural components. As such, a range of factors that affect the catalytic reactivity, such as the size, shape, and composition of the nanoparticles (NPs), have been identified. Herein, high‐surface‐area model catalysts that were based on colloidal Pd NPs and a hexagonally ordered mesoporous carbon support were prepared and the impact of various organic capping agents for the Pd NPs on their catalytic activity towards Suzuki coupling reactions was investigated. Colloidal Pd NPs (diameter: 3 nm) were synthesized with different organic capping agents, oleylamine (OA) and trioctylphosphine (TOP), and they were subsequently incorporated into the mesopores of CMK‐3 mesoporous carbon to yield OA‐Pd/CMK‐3 and TOP‐Pd/CMK‐3 nanocatalysts, respectively. The OA‐Pd/CMK‐3 catalyst was treated with acetic acid to generate a supported catalyst with surfactant‐free Pd NPs (OA‐Pd/CMK‐3‐A). Structural characterization revealed that the Pd NPs were uniformly dispersed throughout the mesopores of the CMK‐3 support and the particle size and crystallinity of the Pd NPs were preserved following the incorporation. All of the Pd/CMK‐3 nanocatalysts exhibited higher activity than commercial activated carbon supported Pd catalysts in Suzuki coupling reactions. The catalytic activities of the three Pd/CMK‐3 nanocatalysts were in the following order: OA‐Pd/CMK‐3‐A>OA‐Pd/CMK‐3>TOP‐Pd/CMK‐3. This result suggested that the presence and type of surfactants had a significant effect on the catalytic activity. The OA‐Pd/CMK‐3‐A catalyst also showed high activity for various substrates and good recycling ability in Suzuki coupling reactions.
Study of the Durability of Faceted Pt3Ni Oxygen–Reduction Electrocatalysts
Authors: Wu Jianbo , Yang Hong
Published: July 2012

The durability of truncated octahedral Pt3Ni (t,o‐Pt3Ni) electrocatalysts in the oxygen–reduction reaction (ORR) was investigated by using an accelerated‐durability‐testing procedure. The Pt3Ni/C catalyst lost 21 % of its initial electrochemical surface area (ECSA) and 40 % of the mass‐current density (0.55 to 0.33 A mgPt−1) after 30 000 potential cycles under acidic conditions. In comparison, the reference commercial Pt/C catalyst lost 44 % of its initial ECSA and had a final mass‐specific activity of only 0.09 A mgPt−1 under identical testing conditions. This study shows the potentials of this class of Pt3Ni/C nanostructures as highly active and durable ORR catalysts.
Lithiated Tertiary Carbanions Display Variable Coordination Modes: Evidence from DFT and NMR Studies
Authors: Vincent Mark A. , Campbell Smith Alison , Donnard Morgan , Harford Philip J. , Haywood Joanna , Hillier Ian H. , Clayden Jonathan , Wheatley Andrew E. H.
Published: July 2012

Density functional calculations reveal that, whereas the reaction of 2‐propyl‐N,N‐diisopropylbenzamide (6) with tBuLi in the presence of potentially tridentate donor ligands may result in lateral deprotonation of 6, the behavior of the Lewis base is non‐trivial. The ability of N and O donor centers in the co‐solvent to resist Li+ coordination is found to be synonymous with interaction of lithium with the formally deprotonated carbanion center. Low‐energy structures have been identified whose predicted 1H and 13C NMR spectroscopic shifts are in excellent agreement with experiment. Reaction of 2‐isopropyl‐N,N‐diisopropylbenzamide (5) with tBuLi in the presence of bidentate Lewis base N,N,N′,N′‐tetramethylethylenediamine (TMEDA) yields material that is suggested by NMR spectroscopy to be laterally deprotonated and to have the formulation 5‐Lil⋅TMEDA. In spite of the tertiary aliphatic group at the 2‐position in 5, X‐ray crystallography reveals that the crystalline material isolated from the treatment of 5/(−)‐sparteine with tBuLi is a lateral lithiate in which amide coordination and solvation by bidentate Lewis base results in the Li+ ion interacting with the deprotonated α‐C of the 2‐iPr group (2.483(8) Å). The tertiary carbanion center remains essentially flat and the adjacent aromatic system is highly distorted. The use of a chiral co‐solvent results in two diastereomeric conformers, and their direct observation in solution suggests that interconversion is slow on the NMR timescale.
Phenalenyl‐Based Organozinc Catalysts for Intramolecular Hydroamination Reactions: A Combined Catalytic, Kinetic, and Mechanistic Investigation of the Catalytic Cycle
Authors: Mukherjee Arup , Sen Tamal K. , Ghorai Pradip Kr. , Samuel Prinson P. , Schulzke Carola , Mandal Swadhin K.
Published: July 2012

Herein, we report the synthesis and characterization of two organozinc complexes that contain symmetrical phenalenyl (PLY)‐based N,N‐ligands. The reactions of phenalenyl‐based ligands with ZnMe2 led to the formation of organozinc complexes [N(Me),N(Me)‐PLY]ZnMe (1) and [N(iPr),N(iPr)‐PLY]ZnMe (2) under the evolution of methane. Both complexes (1 and 2) were characterized by NMR spectroscopy and elemental analysis. The solid‐state structures of complexes 1 and 2 were determined by single‐crystal X‐ray crystallography. Complexes 1 and 2 were used as catalysts for the intramolecular hydroamination of unactivated primary and secondary aminoalkenes. A combined approach of NMR spectroscopy and DFT calculations was utilized to obtain better insight into the mechanistic features of the zinc‐catalyzed hydroamination reactions. The progress of the catalysis for primary and secondary aminoalkene substrates with catalyst 2 was investigated by detailed kinetic studies, including kinetic isotope effect measurements. These results suggested pseudo‐first‐order kinetics for both primary and secondary aminoalkene activation processes. Eyring and Arrhenius analyses for the cyclization of a model secondary aminoalkene substrate afforded ΔH≠=11.3 kcal mol−1, ΔS≠=−35.75 cal K−1 mol−1, and Ea=11.68 kcal mol−1. Complex 2 exhibited much‐higher catalytic activity than complex 1 under identical reaction conditions. The in situ NMR experiments supported the formation of a catalytically active zinc cation and the DFT calculations showed that more active catalyst 2 generated a more stable cation. The stability of the catalytically active zinc cation was further supported by an in situ recycling procedure, thereby confirming the retention of catalytic activity of compound 2 for successive catalytic cycles. The DFT calculations showed that the preferred pathway for the zinc‐catalyzed hydroamination reactions is alkene activation rather than the alternative amine‐activation pathway. A detailed investigation with DFT methods emphasized that the remarkably higher catalytic efficiency of catalyst 2 originated from its superior stability and the facile formation of its cation compared to that derived from catalyst 1.
Electrochemical and Theoretical Investigations of the Role of the Appended Base on the Reduction of Protons by [Fe2(CO)4(κ2‐PNPR)(μ‐S(CH2)3S] (PNPR={Ph2PCH2}2NR, R=Me, Ph)
Authors: Lounissi Sondes , Zampella Giuseppe , Capon Jean‐François , De Gioia Luca , Matoussi Fatma , Mahfoudhi Sélim , Pétillon François Y. , Schollhammer Philippe , Talarmin Jean
Published: July 2012

The behavior of [Fe2(CO)4(κ2‐PNPR)(μ‐pdt)] (PNPR=(Ph2PCH2)2NR, R=Me (1), Ph (2); pdt=S(CH2)3S) in the presence of acids is investigated experimentally and theoretically (using density functional theory) in order to determine the mechanisms of the proton reduction steps supported by these complexes, and to assess the role of the PNPR appended base in these processes for different redox states of the metal centers. The nature of the R substituent of the nitrogen base does not substantially affect the course of the protonation of the neutral complex by CF3SO3H or CH3SO3H; the cation with a bridging hydride ligand, 1 μH+ (R=Me) or 2 μH+ (R=Ph) is obtained rapidly. Only 1 μH+ can be protonated at the nitrogen atom of the PNP chelate by HBF4⋅Et2O or CF3SO3H, which results in a positive shift of the proton reduction by approximately 0.15 V. The theoretical study demonstrates that in this process, dihydrogen can be released from a η2‐H2 species in the FeIFeII state. When R=Ph, the bridging hydride cation 2 μH+ cannot be protonated at the amine function by HBF4⋅Et2O or CF3SO3H, and protonation at the N atom of the one‐electron reduced analogue is also less favored than that of a S atom of the partially de‐coordinated dithiolate bridge. In this situation, proton reduction occurs at the potential of the bridging hydride cation, 2 μH+. The rate constants of the overall proton reduction processes are small for both complexes 1 and 2 (kobs≈4–7 s−1) because of the slow intramolecular proton migration and H2 release steps identified by the theoretical study.
ChemInform Abstract: An Unprecedented AB2 Tetrahedra Network Structure Type in a High‐Pressure Phase of Phosphorus Oxonitride (PON).
Authors: Baumann Dominik , Sedlmaier Stefan J. , Schnick Wolfgang
Published: July 2012

A new high‐pressure polymorph of PON is synthesized by treating PO0.88N1.24H0.56 at around 1350 °C and 12 GPa for 120 min in a Walker‐type module.
ChemInform Abstract: CuBr2 — A New Multiferroic Material with High Critical Temperature.
Authors: Wu Maw‐Kuen , et al. et al.
Published: July 2012

Anhydrous CuBr2 exhibits multiferroicity with a high transition temperature close to liquid nitrogen temperature.
ChemInform Abstract: Magnetocaloric Effect in RAl2 (R: Nd, Sm, and Tm): Promising for Cryogenic Refrigeration Close to Liquid Helium Temperature.
Authors: Patra M. , Majumdar S. , Giri S. , Xiao Y. , Chatterji T.
Published: July 2012

Single crystals of NdAl2 and TmAl2 show substantial magnetocaloric effects at their Curie temperatures, which are close to liquid nitrogen and helium temperature, respectively.
ChemInform Abstract: Synthesis, Structure, and Electrochemical Properties of the Layered Sodium Insertion Cathode Material: NaNi1/3Mn1/3Co1/3O2.
Authors: Sathiya M. , Hemalatha K. , Ramesha K. , Tarascon J.‐M. , Prakash A. S.
Published: July 2012

The layered title phase, which is isostructural to NaCoO2, is synthesized by the sol—gel method starting with an aqueous solution of a stoichiometric mixture of Na, Co, Ni, and Mn acetates and citric acid (900 °C, 12 h).
ChemInform Abstract: Carbon—Carbon Bond Formation by Ligand‐Free Cross‐Coupling Reaction Using Palladium Catalyst Supported on Synthetic Adsorbent.
Authors: Monguchi Yasunari , Sakai Keita , Endo Koichi , Fujita Yuki , Niimura Masaru , Yoshimura Masatoshi , Mizusaki Tomoteru , Sawama Yoshinari , Sajiki Hironao
Published: July 2012

The catalyst is used three times in the Suzuki—Miyaura reaction of (Ia) and (II) with a slight loss in activity.
ChemInform Abstract: Iron‐Catalyzed Highly Enantioselective Reduction of Aromatic Ketones with Chiral P2N4‐Type Macrocycles.
Authors: Yu Shenluan , Shen Weiyi , Li Yanyun , Dong Zhenrong , Xu Yaqing , Li Qi , Zhang Juanni , Gao Jingxing
Published: July 2012

The catalytic system in situ generated from the iron carbonyl complex and chiral 22‐membered tetraazadiphospha‐macrocycle PAC exhibits high activity and excellent enantioselectivity in the transfer hydrogenation of various aromatic ketones.
ChemInform Abstract: Catalytic Asymmetric Synthesis of Chromenes and Tetrahydroquinolines via Sequential Allylic Alkylation and Intramolecular Heck Coupling.
Authors: Hornillos Valentin , van Zijl Anthoni W. , Feringa Ben L.
Published: July 2012

Highly enantioselective synthesis of title compounds (IV) is achieved by combining asymmetric Cu‐catalyzed allylic substitution with Grignard reagents (II) and intramolecular Heck reaction.
ChemInform Abstract: Silica‐Supported 5‐(Pyrrolidin‐2‐yl)tetrazole: Development of Organocatalytic Processes from Batch to Continuous‐Flow Conditions.
Authors: Bortolini Olga , Caciolli Lorenzo , Cavazzini Alberto , Costa Valentina , Greco Roberto , Massi Alessandro , Pasti Luisa
Published: July 2012

A novel immobilized proline mimetic is prepared and tested as a heterogeneous catalyst in α‐amination, Mannich, and Michael reactions under batch conditions.
ChemInform Abstract: Highly Efficient Synthesis of Ureas and Carbamates from Amides by Iodosylbenzene‐Induced Hofmann Rearrangement.
Authors: Liu Peng , Wang Zhiming , Hu Xianming
Published: July 2012

The title method is also applicable to the synthesis of imidazole and oxazole derivatives via an intramolecular rearrangement, and to the synthesis of ureidopeptides from N‐protected amino amides and amino acid esters.
ChemInform Abstract: The Iridium‐Catalyzed Synthesis of Symmetrically and Unsymmetrically Alkylated Diamines under Mild Reaction Conditions.
Authors: Michlik Stefan , Hille Toni , Kempe Rhett
Published: July 2012

Benzene‐1,4‐, 1,3,‐ and 1,2‐diamines and antibiotic diamine dapsone (Id) are transformed to the title diamines by reaction with benzylic or aliphatic alcohols.
ChemInform Abstract: Regioselective Hydrocarbamoylation of 1‐Alkenes.
Authors: Miyazaki Yosuke , Yamada Yuuya , Nakao Yoshiaki , Hiyama Tamejiro
Published: July 2012

The reaction proceeds with anti‐Markownikow selectivity.
ChemInform Abstract: Diastereo‐ and Enantioselective Iridium‐Catalyzed Carbonyl Propargylation from the Alcohol or Aldehyde Oxidation Level: 1,3‐Enynes as Allenylmetal Equivalents.
Authors: Geary Laina M. , Woo Sang Kook , Leung Joyce C. , Krische Michael J.
Published: July 2012

In the presence of SEGPHOS catalysts, the reaction proceeds generally with high anti‐selectivity regardless whether alcohols or aldehydes are used.
ChemInform Abstract: A Highly Efficient Palladium‐Catalyzed One‐Pot Synthesis of Unsymmetrical Aryl Alkyl Thioethers under Mild Conditions in Water.
Authors: Wang Liang , Zhou Wei‐You , Chen Sheng‐Chun , He Ming‐Yang , Chen Qun
Published: July 2012

The title reaction of aryl chlorides or bromides with alkyl halides and thiourea as thiol surrogate proceeds at room temperature in many cases.
ChemInform Abstract: Copper‐Catalyzed Oxidative Hydrosulfonylation of Alkynes Using Sodium Sulfinates in Air.
Authors: Taniguchi Nobukazu
Published: July 2012

The reaction proceeds with high syn‐selectivity to afford a broad spectrum of (E)‐alkenyl sulfones from terminal and internal alkynes bearing both alkyl and aryl substituents.
ChemInform Abstract: Regioselective and Stereospecific Cross‐Coupling of Primary Allylic Amines with Boronic Acids and Boronates Through Palladium‐Catalyzed C—N Bond Cleavage.
Authors: Li Man‐Bo , Wang Yong , Tian Shi‐Kai
Published: July 2012

The method is based on the exploiting of the free amino group as an effective leaving group.
ChemInform Abstract: Gold‐Catalyzed Oxidative Cyclizations of cis‐3‐En‐1‐ynes To Form Cyclopentenone Derivatives.
Authors: Bhunia Sabyasachi , Ghorpade Satish , Huple Deepak B. , Liu Rai‐Shung
Published: July 2012

Various indanone and cyclopentenone products are obtained from the corresponding benzene‐ and non‐benzene‐derived substrates.
ChemInform Abstract: A Cobalt‐Catalyzed Domino Route to the ABC Tricyclic Core of Strigolactones and Analogues.
Authors: Le Floch Camille , Laymand Kevin , Le Gall Erwan , Leonel Eric
Published: July 2012

ortho‐Bromobenzaldehydes or β‐bromo‐α,β‐unsaturated cyclic aldehydes undergo with itaconate (II) a cyclization reaction to give tricyclic cis‐fused cyclopenta[b]furanones as single diastereomers.
ChemInform Abstract: Pd‐Catalyzed Diastereo‐ and Enantioselective [3 + 2]‐Cycloaddition Reaction of Vinyl Epoxide with Nitroalkenes.
Authors: Wu Wen‐Qiong , Ding Chang‐Hua , Hou Xue‐Long
Published: July 2012

A convenient protocol employing a chiral ferrocenyl‐based oxazoline ligand is developed which affords highly substituted tetrahydrofurans.
ChemInform Abstract: A New Copper(I)‐Catalyzed Cycloetherification/Acid‐Catalyzed Allylic Nucleophilic Substitution for One‐Pot Synthesis of 2‐Substituted Benzofurans.
Authors: Li Xin , Xue Jijun , Chen Rui , Li Ying
Published: July 2012

The cycloetherification process affords alkylidene‐substituted dihydrobenzofuran structures.
ChemInform Abstract: Benzofurans from Benzophenones and Dimethylacetamide: Copper‐Promoted Cascade Formation of Furan O1—C2 and C2—C3 Bonds under Oxidative Conditions.
Authors: Moure Maria J. , SanMartin Raul , Dominguez Esther
Published: July 2012

For the title synthesis, commercially available or readily synthesized starting materials are used.
ChemInform Abstract: Ruthenium(II)‐Catalyzed Regio‐ and Stereoselective Hydroarylation of Alkynes via Directed C—H Functionalization.
Authors: Hashimoto Yuto , Hirano Koji , Satoh Tetsuya , Kakiuchi Fumitoshi , Miura Masahiro
Published: July 2012

Stereo‐ and regioselective reaction of various benzamides with internal and terminal alkynes is best achieved under conditions A).
ChemInform Abstract: Regioselective Intramolecular [3 + 2] Annulation of Allene‐Nitrones.
Authors: Inagaki Fuyuhiko , Kobayashi Harumi , Mukai Chisato
Published: July 2012

Intramolecular cycloaddition of a variety of in situ generated phenylsulfonyl‐substituted allene‐nitrones proceeds exclusively at the distal double bond to afford fused isoxazoles, irrespective of the substitution pattern at the allene.
ChemInform Abstract: Synthesis and Antimicrobial Evaluation of New Pyrano[4,3‐b]pyran and Pyrano[3,2‐c]chromene Derivatives Bearing a 2‐Thiophenoxyquinoline Nucleus.
Authors: Makawana Jigar A. , Patel Manish P. , Patel Ranjan G.
Published: July 2012

Eighteen compounds of type (IV) and nine compounds of type (VI) are prepared and evaluated for their antimicrobial activities.
ChemInform Abstract: One‐Pot Preparation of Piperazines by Regioselective Ring‐Opening of Non‐Activated Arylaziridines.
Authors: Trinchera Piera , Musio Biagia , Degennaro Leonardo , Moliterni Anna , Falcicchio Aurelia , Luisi Renzo
Published: July 2012

The method provides a new straightforward approach to cis‐ and trans‐2,5‐disubstituted piperazines.
ChemInform Abstract: Temporary Silicon‐Tethered Ring‐Closing Metathesis: Recent Advances in Methodology Development and Natural Product Synthesis
Authors: Cusak Alen
Published: July 2012

Review: ca.100 refs.
ChemInform Abstract: A New Approach Towards the Asymmetric Fluorination of Alkenes Using Anionic Phase‐Transfer Catalysts
Authors: Hennecke Ulrich
Published: July 2012

Review: 25 refs.
ChemInform Abstract: Recent Advances in Metallo/Organo‐Catalyzed Immortal Ring‐Opening Polymerization of Cyclic Carbonates.
Authors: Guillaume Sophie M. , Carpentier Jean‐Francois
Published: July 2012

Review: ca. 50 refs.
ChemInform Abstract: Heteroditopic Receptors for Ion‐Pair Recognition.
Authors: McConnell Anna J. , Beer Paul D.
Published: July 2012

Review: 46 refs.
ChemInform Abstract: Approaches to Dihydrooxazine Ring Systems and Application in the Synthesis of Bioactive Natural Products
Authors: Gu Z. , Saito T. , Zakarian A.
Published: July 2012

Review: 17 refs.
ChemInform Abstract: Synthesis of Fused Heterocycles via Pd‐Catalyzed Multiple Aromatic C—H Activation Reactions
Authors: Gulevich A. V. , Gevorgyan V.
Published: July 2012

Review: 24 refs.
ChemInform Abstract: Intramolecular Cyclizations of Functionalized Diynes
Authors: Danilkina N. A. , Kulyashova A. E. , Balova I. A.
Published: July 2012

Review: 47 refs.
ChemInform Abstract: Synthesis of Heterocycles Using Amphoteric Molecules
Authors: Yudin A. K.
Published: July 2012

Review: 17 refs.
ChemInform Abstract: Rational Design of Heterogeneous Catalysts for Biodiesel Synthesis.
Authors: Wilson Karen , Lee Adam F.
Published: July 2012

Review: 180 refs.
ChemInform Abstract: High Shear Mixers: Typical Applications and Studies on Power Draw, Flow Pattern, Energy Dissipation and Transfer Properties
Authors: Zhang Jinli , Xu Shuangqing , Li Wei
Published: July 2012

Review: 113 refs.
9‐Benzylidene‐9H‐fluorene Derivatives Linked to Monoaza‐15‐crown‐5: Synthesis and Metal Ion Sensing
Authors: Cao Jing , Li Yang , Feng Junxiang
Published: July 2012

Two kinds of novel styryl chemosensory 2‐FMNC and 3‐FMNC, were designed and synthesized by an apporiate introduction of 9‐benzylidene‐9H‐fluorene group as fluorophore with the aim at avoiding photoisomerisation. These 9‐benzylidene‐9H‐fluorene derivatives showed the similar selectivity and sensitivity upon addition of metal ions. The sensitivity of FMNC to alkaline earth metal ions was Ba2+>Sr2+>Ca2+≈Mg2+.
pH‐Dependent Metal‐Enhanced Fluorescence from CdTe@PAA Nanospheres near the Au Nanoparticles in Aqueous Solution
Authors: Li Rongqing , Wang Chunlei , Xu Shuhong , Wang Zhuyuan , Shao Haibao , Cui Yiping
Published: July 2012

Metal‐enhanced fluorescence of semiconductor nanocrystals (NCs) is the current investigation focus. In this work, we directly observed metal‐enhanced fluorescence of CdTe@PAA nanaospheres in aqueous solution. The enhanced magnitude of photoluminescence (PL) was closely related to solution pH values, and the maximal PL enhancement is about 9 times compared with the ones without Au NPs. Furthermore, based on the results of absorptions and fluorescence lifetimes of CdTe@PAA‐Au mixed solution at different pH values, we studied the mechanisms and physics processes of pH‐dependent enhanced PL induced by Au NPs. The pH‐dependent PL of CdTe@PAA‐Au mixed solutions are due to the constantly changing distances between Au NPs and CdTe@PAA nanaospheres with pH. In the CdTe@PAA‐Au mixed solutions, CdTe@PAA nanospheres in close proximity to the Au NPs are exposed to the increased electric fields in between and around the NPs, effectively resulting in significant increases in their absorption cross section. This lends itself to a subsequent increase in the excitation and eventually in the fluorescence emission from the CdTe@PAA nanospheres.
Superior Storage Performance for NO in Modified Natural Mordenite
Authors: Wang Hui , Yu Qinqin , Xiao Liping , Liu Tong , Yu Wanjin , Jiang Xiaoyuan , Zhang Xuming , Zheng Xiaoming
Published: July 2012

Natural mordenite (NMOR), modified by acid treatment and ion‐exchange, was employed for NO adsorption in the present study. The NO storage capacity of modified NMOR was greatly improved compared with its original correspondents, mainly due to the preservation of crystalline structure and the improvement of surface area of NMOR. Among all the modified NMOR, Ni‐NMOR exhibited the highest adsorption capacity for NO (1.20 mmol·g−1) in the presence of 10% O2 at 308 K. The influence of the main ingredients in flue gas on the storage capacity of NMOR for NO had also been investigated. In general, H2O, CO2 and SO2 all displayed negative impact on NO adsorption due to their competitive adsorption on the surface of NMOR with NO, while the presence of O2 greatly improved the adsorption of NO because of the formation of NO2 and N2O3. Moreover, Ni‐NMOR exhibited high efficiency for NOx removal through the NOx adsorption‐plasma discharge process.
Preparation of Hierarchical Mesoporous Silica Nanoparticles through a Single‐Templating Approach
Authors: Chen Yuanli , Xiao Min , Zhuang Wei , Li Yi , Li Baozong , Yang Yonggang
Published: July 2012

Silicas with hierarchical porous architectures attracted much attention, due to their potential applications in catalysis and separation. Generally, they were prepared through dual‐ or triple‐templating approaches. Herein, mesoporous silica nanoparticles with rod‐like pore channels inside and lamellar mesopores on the surfaces were prepared using the self‐assemblies of a chiral low‐molecular‐weight amphiphile as templates through a single‐templating approach. The formation of the lamellar mesopores was studied by taking field‐emission scanning electron microscopy and transmission electron microscopy images after different reaction times. The lamellar pores were proposed to be formed by merging rod‐like micelles during the sol‐gel process. Moreover, helical nanofibers with rod‐like pore channels inside and lamellar mesopores on the surfaces were prepared with the addition of n‐octanol as a co‐structure‐directing agent.