bluuebunny/crossref_metadata_2025 huggingface dataset:
Blocking Effect on Adsorption‐Controlled Electrochemiluminescence of CdSe Nanoparticles for Detection of the Neurotransmitter Serotonin
Authors: Jiang Hui , Wang Xuemei
Published: April 2011

Herein, we have designed a special strategy for detection of the important neurotransmitter serotonin by coupling the electrodeposition of serotonin oxidative products with the adsorption‐controlled anodic electrochemiluminescent dynamics of the CdSe–triethylamine system. The stable electrochemiluminescent emission is found to decline in the presence of serotonin. This uncommon inhibition is attributed to the gradual accumulation of the electropolymerized serotonin products, which decrease the adsorbance of CdSe nanoparticles on the glass carbon electrode, as demonstrated by the scanning electron microscopic images (SEM) and the stripping voltammetric identification. Based on the inhibition effect, a facile strategy has been developed to sensitively detect the serotonin ranging from 0.2–10 μM, with a detection limit of 0.1 μM. The interference from the common species including ascorbic acid and uric acid has been investigated. The recovery rates in the spiked serum samples range from 94–112 %, thereby implicating its potential applications in the complex bioassays.
Regioselective, Unconventional Pictet–Spengler Cyclization Strategy Toward the Synthesis of Benzimidazole‐Linked Imidazoquinoxalines on a Soluble Polymer Support
Authors: Chen Chih‐Hau , Kuo Jaren , Yellol Gorakh S. , Sun Chung‐Ming
Published: April 2011

A novel strategy for an unconventional Pictet–Spengler reaction has been developed for the regioselective cyclization of the imidazole ring system at the C2 position. The developed strategy was utilized to develop a diversity‐oriented parallel synthesis for bis(heterocyclic) skeletal novel analogs of benzimidazole‐linked imidazoquinoxalines on a soluble polymer support under microwave conditions. Condensation of polymer‐immobilized o‐phenylenediamines with 4‐fluoro‐3‐nitrobenzoic acid followed by nucleophilic aromatic substitution with an imidazole motif affords bis(heterocyclic) skeletal precursors for the Pictet–Spengler reaction. The unconventional Pictet–Spengler cyclization with various aldehydes was achieved regioselectively at the C2 position of the imidazole ring to furnish rare imidazole‐fused quinoxaline skeletons. During the Pictet–Spengler cyclization, aldehydes bearing electron‐donating groups afford 4,5‐dihydro‐imidazoquinoxalines, which then auto‐aromatize into benzimidazole‐linked imidazo[1,2‐a]quinoxalines. However, interestingly, aldehydes bearing electron‐withdrawing groups directly provide aromatized imidazo[1,2‐a]quinoxalines, which unexpectedly afford novel benzimidazole‐linked 4‐methoxy‐4,5‐dihydro‐imidazo[1,2‐a]quinoxalines after polymer cleavage.
The HP1a Disordered C Terminus and Chromo Shadow Domain Cooperate to Select Target Peptide Partners
Authors: Mendez Deanna L. , Kim Daesung , Chruszcz Maksymilian , Stephens Gena E. , Minor Wladek , Khorasanizadeh Sepideh , Elgin Sarah C. R.
Published: April 2011

Drosophila melanogasterheterochromatin protein 1a (HP1a) is essential for compacted heterochromatin structure and the associated gene silencing. Its chromo shadow domain (CSD) is well known for binding to peptides that contain a PXVXL motif. Heterochromatin protein 2 (HP2) is a non‐histone chromosomal protein that associates with HP1a in the pericentric heterochromatin, telomeres, and the fourth chromosome. Using NMR spectroscopy, fluorescence polarization, and site‐directed mutagenesis, we identified an LCVKI motif in HP2 that binds to the HP1a CSD. The binding affinity of the HP2 fragment is approximately two orders of magnitude higher than that of peptides from PIWI (with a PRVKV motif), AF10 (with a PLVVL motif), or CG15356 (with LYPLL and LSIVA motifs). To delineate differential interactions of the HP1a CSD, we characterized its structure, backbone dynamics, and dimerization constant. We found that the dimerization constant is bracketed by the affinities of HP2 and PIWI, which dock to the same HP1a homodimer surface. This suggests that HP2, but not PIWI, interaction can drive the homodimerization of HP1a. Interestingly, the integrity of the disordered C‐terminal extension (CTE) of HP1a is essential for discriminatory binding, whereas swapping the PXVXL motifs does not confer specificity. Serine phosphorylation at the peptide binding surface of the CSD is thought to regulate heterochromatin assembly. Glutamic acid substitution at these sites destabilizes HP1a dimers, but improves the interaction with both binding partners. Our studies underscore the importance of CSD dimerization and cooperation with the CTE in forming distinct complexes of HP1a.
Lanthanum Oxide Supported on Carbon Nanofibers as Solid Base Catalysts
Authors: Frey Anne Mette , Bitter Johannes Hendrik , de Jong Krijn Pieter
Published: April 2011

Bulk lanthanum oxide and lanthanum oxide supported on carbon nanofibers were studied as solid base catalysts. The impact of synthesis parameters on the supported catalysts, deposition method, aging, washing, and heat treatment temperature were investigated and evaluated by studying the catalytic activities in the self‐condensation reaction of acetone to diacetone alcohol. The initial activity of the carbon nanofiber (CNF) supported lanthanum oxide catalysts (48 mmolDAA h−1 gcatalyst−1, DAA=diacetone alcohol) was up by one order of magnitude compared to the activity of the bulk lanthanum oxide (4.4 mmolDAA h−1 gcatalyst−1). The most active catalyst reported here was 12 wt % La2O3/CNF, prepared from a lanthanum nitrate precursor by precipitation with ammonia, followed by washing, drying, and heating at temperatures between 600–700 °C in nitrogen to activate the catalyst. Initial enthalpies for CO2 adsorption, determined by using micro calorimetry, are approximately 155 kJ mol−1 (CO2 uptake 0–5 μmol g−1) for supported samples with 12 wt % La2O3. TEM revealed well‐distributed and small (≈4 nm) lanthanum oxide particles on the support.
Mechanism of Cytotoxicity and Cellular Uptake of Lipophilic Inert Dinuclear Polypyridylruthenium(II) Complexes
Authors: Pisani Michelle J. , Fromm Phillip D. , Mulyana Yanyan , Clarke Ronald J. , Körner Heinrich , Heimann Kirsten , Collins J. Grant , Keene F. Richard
Published: April 2011

The accumulation, uptake mechanism, cytotoxicity, cellular localisation of—and mode of cell death induced by—dinuclear ruthenium(II) complexes ΔΔ/ΛΛ‐[{Ru(phen)2}2{μ‐bbn}]4+ (Rubbn), where phen is 1,10‐phenanthroline, bbn is bis[4(4′‐methyl‐2,2′‐bipyridyl)]‐1,n‐alkane (n=2, 5, 7, 10, 12 or 16), and the corresponding mononuclear complexes containing the bbn ligands, were studied in L1210 murine leukaemia cells. Cytotoxicity increased with linker chain length, and the ΔΔ‐Rubb16 complex displayed the highest cytotoxicity of the series, with an IC50 value of 5 μM, similar to that of carboplatin in the L1210 murine leukaemia cell line. Confocal microscopy and flow cytometry studies indicated that the complexes accumulate in the mitochondria of L1210 cells, with the magnitude of cellular uptake and accumulation increasing with linking chain length in the bbn bridge of the metal complex. ΔΔ‐Rubb16 entered the L1210 cells by passive diffusion (with a minor contribution from protein‐mediated active transport), inducing cell death via apoptosis. Additionally, metal‐complex uptake in leukaemia cells was approximately 16‐times that observed in healthy B cells highlighting that the bbn series of complexes may have potential as selective anticancer drugs.
Mechanistic Photodissociation of Glycolaldehyde: Insights from Ab Initio and RRKM Calculations
Authors: Cui Ganglong , Fang Weihai
Published: April 2011

Herein we report a theoretical study on mechanistic photodissociation of glycolaldehyde, HOCH2CHO. Equilibrium structures, transition states, and intersection structures for the α‐CC and ‐CH bond fissions and the β‐CO bond fission in the excited states are determined by the complete active space self‐consistent field (CASSCF) method. Based on the CASSCF optimized structures, the potential energy profiles for the dissociations are refined by performing single‐point calculations using the multi‐state multi‐reference CASSCF second order perturbation (MS‐MR‐CASPT2) method. With a low excitation energy of 280–340 nm, the T1 α‐CC and β‐CO bond fissions following intersystem crossing from the S1 state are the predominant and comparable channels, whereas the α‐CH bond fissions both in the S1 and in the T1 states are nearly prohibited due to the relevant high barriers. The rate constants for the T1 α‐CC and β‐CO bond fissions are also calculated by RRKM theory. Furthermore, the S0 reactions can occur as a consequence of intersystem crossing via T1/S0 intersection points resulting from the T1 CC and CO bond cleavages. This photodissociation mechanism is consistent with recent experimental studies.
Diastereoselective Three‐Step Route to o‐(6‐Nitrocyclohex‐3‐en‐1‐yl)phenol and Tetrahydro‐6H‐benzo[c]chromen‐6‐ol Derivatives from Salicylaldehydes
Authors: Lanari Daniela , Ballini Roberto , Palmieri Alessandro , Pizzo Ferdinando , Vaccaro Luigi
Published: April 2011

This work was aimed at preparing o‐(6′‐nitrocyclohex‐3′‐en‐1′‐yl)phenol and tetrahydro‐6H‐benzo[c]chromen‐6‐ol derivatives in three steps starting from salicylaldehydes. Initially 3‐acetylcoumarins were prepared in the absence of solvent using a solid base catalyst such as PS‐TBD. In the second step, the Diels–Alder reactions of 3‐nitrocoumarins and 3‐acetylcoumarins under thermal conditions or in the presence of hafnium chloride yielded the corresponding tetrahydrobenzo[c]chromenones. The final part of the work was dedicated to the transformation of nitro‐tetrahydrobenzo[c]chromenones into o‐(6′‐nitrocyclohex‐3′‐en‐1′‐yl)phenol derivatives in aqueous medium and to the conversion of acetyl tetrahydrobenzo[c]chromenones into the corresponding tetrahydro‐6H‐benzo[c]chromen‐6‐ol derivatives in tetrahydrofuran (THF), in the presence of tetrabutylammonium fluoride (TBAF) on silica. In every case the diastereoselectivity was complete and the reaction yields were high.
U‐Pb zircon geochronology of granites and charnockite from southern India: implications for magmatic pulses associated with plate tectonic cycles within a Precambrian suture zone
Authors: Sato Kei , Santosh M. , Chetty T. R. K. , Hirata Takafumi
Published: April 2011

The Palghat–Cauvery Suture Zone (PCSZ) in southern India marks the trace along which continental blocks were sutured during the Precambrian. We report here U‐Pb geochronological data based on laser ablation ICP mass spectrometry for zircons in two granite plutons and an associated charnockite from within the PCSZ. The weighted mean of 206Pb/238U ages for a rapakivi granite from the southern part of the PCSZ yields 819 ± 26 Ma (error: 2σ; N = 13). On the other hand, a metamorphosed A‐type granite and a charnockite from the central part of the PCSZ yield a markedly older upper intercept age of 2468 ± 36 Ma (error: 2σ) and a lower intercept age of 588 ± 36 Ma (error: 2σ). Our results provide important constraints on the Precambrian crustal evolution in the PCSZ and demonstrate: (1) Neoarchaean to early Palaeoproterozoic magmatism, generating A‐type granites which we correlate with a major global crustal formation event; (2) mid Neoproterozoic magmatism, and generation of the rapakivi granite, probably associated with the subduction of the Mozambique Ocean floor; and (3) latest Neoproterozoic high‐grade metamorphism (generating the charnockite) associated with the collisional amalgamation of the Gondwana supercontinent. Together with the previous geochronological data from the PCSZ and adjacent crustal blocks, our results provide information on magmatic pulses associated with the Archaean cratonization event, as well as the Neoproterozoic Wilson Cycle of the Mozambique Ocean culminating in continent‐continent collision. Copyright © 2011 John Wiley & Sons, Ltd.
Early Precambrian mafic dyke swarms from the Central Archaean Bastar Craton, India: geochemistry, petrogenesis and tectonic implications
Authors: Srivastava Rajesh K. , Gautam Gulab C.
Published: April 2011

The Archaean Bastar craton is known for the presence of different generations of mafic dykes. Less studied many NW‐SE trending mafic dykes (intruded into the Archaean supracrustal rocks), encountered from the central part of the Bastar craton, are studied for their petrological and geochemical characteristics. There are many geological evidences which suggest emplacement of these mafic dykes in an intracratonic setting. Two distinct types of mafic dykes are recognized. Petrographically it is difficult to discriminate these two types. Many samples show metamorphic textures and amphibolites facies mineral assemblage but a few samples preserved original igneous texture and mineralogy. Major oxides show sub‐alkaline thoeliitic basalt/basaltic andesite nature. High‐Fe and high‐Mg contents classify them as high‐iron and high‐magnesium tholeiites. They fall in the gabbronorite field on R1‐R2 plot. Geochemical characteristics, particularly high‐field strength and rare‐earth elements, clearly distinguished them into two types: Group 1 and Group 2 mafic dykes. When compared with well‐studied mafic dyke swarms of the Southern Bastar craton, the Group 1 is recognized as Meso‐Neoarchaean sub‐alkaline mafic dykes (BD1‐CBC) and the Group 2 as Neoarchaean‐Palaeoproterozoic boninite–norite mafic dykes (BN‐CBC). The boninite–norite nature of the second group is also corroborated through immobile trace element ratios. BD1‐CBC dykes are characterized by a relatively higher concentration of HFSE and REE in comparison to BN‐CBC dykes. Some extent of crustal contamination is observed in BN‐CBC dykes but BD1‐CBC dykes do not show any indication of crustal contamination. Trace element modelling suggest that BD1‐CBC mafic dykes are derived from a melt originated through ∼20% melting of a depleted mantle source, whereas BN‐CBC mafic dykes are probably derived from a high‐Mg magma generated through ∼25% melting of a refractory mantle source. Both melts have undergone 30–40% olivine fractionation before the emplacement. Geochemistry also points out involvement of a plume in the genesis of these mafic dykes. Copyright © 2011 John Wiley & Sons, Ltd.
Laryngeal neuromonitoring and neurostimulation versus neurostimulation alone in thyroid surgery: A randomized clinical trial
Authors: Cavicchi Ottavio , Caliceti Umberto , Fernandez Ignacio Javier , Ceroni Alberto Rinaldi , Marcantoni Alessandra , Sciascia Silvia , Sottili Sandra , Piccin Ottavio
Published: April 2011

Background

The aim of this study was to assess a prospective, randomized clinical trial (RCT) comparing neurostimulation with laryngeal palpation (NSLP) of recurrent laringeal nerve (RLN) alone with NSLP associated with laryngeal neuromonitoring (LNM) to evaluate the ability of LNM in reducing the rates of RLN palsy.

Methods

In all, 250 consecutive patients scheduled to have thyroidectomy were randomized to NSLP alone (NSLP group) or NSLP with LNM (LNM group). The primary endpoint was to assess the rate of RLN palsy.

Results

The incidence of palsy was 2.7% in the LMN group and 2.6% in the NSLP group. No significant statistical difference between the groups was observed either for permanent or for transient paralysis (respectively, Fisher's Exact test: p = 1.0 and p = 1.0).

Conclusions

This RCT shows that the use of LNM during thyroidectomy does not reduce the rates of recurrent laryngeal injuries compared with NSLP alone. [Registration number: NCT01163045 (http://www.clinicaltrials.gov).] © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Extreme variability of water table dynamics in temperate calcareous fens: Implications for biodiversity
Authors: Duval Tim P. , Waddington J. M.
Published: April 2011

Calcareous fens are minerotrophic peatlands with very high species diversity, and maintenance of the water table is assumed to be a key contributor to this diversity. However, this assumption is based on limited study of fen water table dynamics. Here we monitor water table fluctuation in distributed locations across three calcareous fens differing in hydrogeomorphic setting for three growing seasons. Water table position was extremely variable with absolute ranges of 89, > 100, and > 118 cm in the Riparian, Trough and Basin Fens, respectively, and was controlled by landscape position and weather variability. Areas adjacent to a second‐order stream experienced the least water table fluctuation, while the Basin Fen, at > 75 m from a surface water connection, was very prone to year‐to‐year precipitation differences. Mean and median water table values were found to be poor indicators of biologically relevant hydroperiods. We introduce the term ‘duration of initial growing season saturation’ as a potentially more useful statistic to relate to plant species distribution. Across the studied fens, this duration ranged from 1 to 14 weeks from the start of the growing season. The water table resided below the ground surface for between 0 and 22 weeks of the growing season across the calcareous fens and study period. These findings impart great differences in the development of oxidized rooting depths. Our results demonstrate that there is much more variation in calcareous fen hydrology than previously reported, and this variability has important implications for fen vegetation patterning and management. Copyright © 2011 John Wiley & Sons, Ltd.
Comparison of assay methods for detection of circulating tumor cells in metastatic breast cancer: AdnaGen AdnaTest BreastCancer Select/Detect™ versus Veridex CellSearch™ system
Authors: Andreopoulou E. , Yang L.‐Y. , Rangel K. M. , Reuben J. M. , Hsu L. , Krishnamurthy S. , Valero V. , Fritsche H. A. , Cristofanilli M.
Published: April 2011

The detection of CTCs prior to and during therapy is an independent and strong prognostic marker, and it is predictive of poor treatment outcome. A major challenge is that different technologies are available for isolation and characterization of CTCs in peripheral blood (PB). We compare the CellSearch system and AdnaTest BreastCancer Select/Detect, to evaluate the extent that these assays differ in their ability to detect CTCs in the PB of MBC patients. CTCs in 7.5 ml of PB were isolated and enumerated using the CellSearch, before new treatment. Two cutoff values of ≥2 and ≥5 CTCs/7.5 ml were used. AdnaTest requires 5 ml of PB to detect gene transcripts of tumor markers (GA733‐2, MUC‐1, and HER2) by RT‐PCR. AdnaTest was scored positive if ≥1 of the transcript PCR products for the 3 markers were detected at a concentration ≥0.15 ng/μl. A total of 55 MBC patients were enrolled. 26 (47%) patients were positive for CTCs by the CellSearch (≥2 cutoff), while 20 (36%) were positive (≥5 cutoff). AdnaTest was positive in 29 (53%) with the individual markers being positive in 18% (GA733‐2), 44% (MUC‐1), and 35% (HER2). Overall positive agreement was 73% for CTC≥2 and 69% for CTC≥5. These preliminary data suggest that the AdnaTest has equivalent sensitivity to that of the CellSearch system in detecting 2 or more CTCs. While there is concordance between these 2 methods, the AdnaTest complements the CellSearch system by improving the overall CTC detection rate and permitting the assessment of genomic markers in CTCs.
Studies on the Biosynthesis of the Stephacidin and Notoamide Natural Products: A Stereochemical and Genetic Conundrum
Authors: Sunderhaus James D. , Sherman David H. , Williams Robert M.
Published: April 2011

The stephacidin and notoamide natural products belong to a group of prenylated indole alkaloids containing a bicyclo[2.2.2]diazaoctane core. Biosynthetically, this bicyclic core is believed to be the product of an intermolecular Diels–Alder (IMDA) cycloaddition of an achiral azadiene. Since all of the natural products in this family have been isolated in enantiomerically pure form to date, it is believed that an elusive Diels–Alderase enzyme mediates the IMDA reaction. Adding further intrigue to this biosynthetic puzzle is the fact that several related Aspergillus fungi produce a number of metabolites with the opposite absolute configuration, implying that these fungi have evolved enantiomerically distinct Diels–Alderases. We have undertaken a program to identify every step in the biogenesis of the stephacidins and notoamides, and by combining the techniques of chemical synthesis and biochemical analysis we have been able to identify the two prenyltransferases involved in the early stages of the stephacidin and notoamide biosyntheses. This has allowed us to propose a modified biosynthesis for stephacidin A, and has brought us closer to our goal of finding evidence for, or against, the presence of a Diels–Alderase in this biosynthetic pathway.
Comment on “intrauterine diagnosis and management of fetal goiter: A case report”
Authors: Bliddal Sofie , Rasmussen Åse Krogh , Sundberg Karin , Brocks Vibeke , Feldt ‐Rasmussen Ulla
Published: April 2011

No absract.
Lessons from 35,000 feet: How ALTOUR used an open mind and an open door policy to energize the travel industry
Authors: Chemla Alexandre
Published: April 2011

When a former Club Med executive decided to leave his comfortable corporate berth of ten years and dive into the waters of entrepreneurship, he chose to stay in the turbulent travel agency business, even though it was reeling from the airline industry's game‐changing deregulation. Rather than sticking with business as usual, he chose to follow an innovative business model and, subsequently, expand on it by creating ALTOUR. Sound strategy, combined with an ability to adapt to meet the needs of his customers, has led to 20 percent annual growth since the company's founding in 1991. This article explains the discipline behind this accomplishment and offers lessons that can apply across all industries. © 2011 Wiley Periodicals, Inc.
Restructuring leads to renewed competitive advantage in global financial services
Authors: Recardo Ronald J.
Published: April 2011

What should an organization's leaders do when they sense that the competition is gaining on them? The answer for one strategic business unit within a global financial services company was “Restructure—and make it fast.” Within three months, the organization set up a project team that analyzed its current situation, identified and evaluated alternative designs, and designed and implemented a new structure. The results were significant improvements in revenues and customer satisfaction and a reduction in overall operating costs and key process‐cycle times. © 2011 Wiley Periodicals, Inc.
Immune-mediated hemolytic anemia in children after liver and small bowel transplantation
Authors: Czubkowski Piotr , Williams Mike , Bagia Seema , Kelly Deirdre , Gupte Girish
Published: April 2011

Four children who underwent ABO-compatible combined liver and small bowel transplantation developed severe immune-mediated hemolytic anemia. The main management strategies were early and aggressive treatment with steroids, the introduction of rituximab (an anti-CD20 monoclonal antibody), and the use of plasma exchange together with compatible but minimal blood transfusions. Three of the 4 children developed thrombi in the major vessels. In small bowel transplant patients, the early recognition of hemolytic anemia and intensified management with anticoagulation are necessary for the prevention of this complication. Liver Transpl 17:921–924, 2011. © 2011 AASLD.
Lysozyme Coated DNA and DNA/SWNT Fibers by Solution Spinning
Authors: Nepal Dhriti , Minus Marilyn L. , Kumar Satish
Published: April 2011

DNA fibers were prepared by solution spinning of DNA in a lysozyme (LSZ) coagulation/gelation bath. Strong positive charges carried by LSZ protein condensed the DNA (strong negative charged) molecules resulting in self‐assembly and the formation of fibrillar structures in a gel‐like network. DNA/LSZ fibril formation was found to be dependent on the ratio of DNA to LSZ. A minimum 0.1 wt.‐% of LSZ was necessary to condense 0.1 wt.‐% of DNA into micro‐fibrils. Macroscopic fiber spinning was possible by introducing a 0.1 wt.‐% DNA aqueous solution into a 0.2 wt.‐% LSZ coagulation bath which resulted in fibers with ≈20 µm diameter. Single‐walled carbon nanotubes (SWNT) were also incorporated into these fibers to explore the possibility for creating hybrid materials. All DNA‐based fibers exhibit strong birefringence confirming molecular orientation along the fiber axis. Due to the presence of LSZ, the fibers exhibit antimicrobial activity against bacteria like Micrococcus lysodeikticus.

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Externally Induced Thermal Actuation of Polymer Nanocomposites
Authors: Hu Ying , Chen Wei
Published: April 2011

Among the stimuli responsive polymers, thermally active polymers have attracted great attention because of the accessible and effective characteristics of thermal stimulation. Nanomaterials with their unique properties could serve as “nanoantennas” and “nanoheaters” for harvesting external energy such as electrical, optical, and magnetic, and then convert them into useful thermal energy. With a uniform mixture of the nanomaterials, an external stimulus which has no impact on the thermally responsive polymers could effectively induce the mechanical actuation of polymer nanocomposites. Hence, the trend article aims to present a brief overview of recent progress on the externally induced thermal actuation of polymer nanocomposites as well as provide a summary of the thermal actuation mechanisms. Examples are introduced to highlight the influence of embedded nanomaterials during the actuation progress.

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Synthesis and Gas Permeation Properties of Spirobischromane‐Based Polymers of Intrinsic Microporosity
Authors: Fritsch Detlev , Bengtson Gisela , Carta Mariolino , McKeown Neil B.
Published: April 2011

Polymers of intrinsic microporosity (PIMs) possess molecular structures composed of fused rings with linear units linked together by a site of contortion so that the macromolecular structure is both rigid and highly non‐linear. For PIM‐1, which has previously demonstrated encouraging gas permeability data, the site of contortion is provided by the monomer 5,5′,6,6′‐tetrahydroxy‐3,3,3′,3′‐tetramethyl‐1,1′‐spirobisindane. Here we describe the synthesis and properties of a PIM derived from the structurally related 6,6′,7,7′‐tetrahydroxy‐4,4,4′,4′‐tetramethyl‐2,2′‐spirobischromane and copolymers prepared from combination of this monomer with other PIM‐forming biscatechol monomers, including the highly rigid monomer 9,10‐dimethyl‐9,10‐ethano‐9,10‐dihydro‐2,3,6,7‐tetrahydroxyanthracene. Generally, the polymers display good solubility in organic solvents and have high average molecular masses ($\overline {M} _{{\rm w}} $) in the range 80 000–200 000 g · mol−1 and, therefore, are able to form robust, solvent‐cast films. Gas permeability and selectivity for He, H2, N2, O2, CO2, and CH4 were measured for the polymers and compared to the values previously obtained for PIM‐1. The spirobischromane‐based polymers demonstrate enhanced selectivity for a number of gas pairs but with significantly lower values for permeability. The solubility coefficient for CO2 of two of the copolymers exceed even that of PIM‐1, which previously demonstrated the highest value for a membrane‐forming polymer. Therefore, these polymers might be useful for gas or vapor separations relying on solubility selectivity.

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HPMA Based Amphiphilic Copolymers Mediate Central Nervous Effects of Domperidone
Authors: Hemmelmann Mirjam , Knoth Christiane , Schmitt Ulrich , Allmeroth Mareli , Moderegger Dorothea , Barz Matthias , Koynov Kaloian , Hiemke Christoph , Rösch Frank , Zentel Rudolf
Published: April 2011

In this study we give evidence that domperidone encapsulated into amphiphilic p(HPMA)‐co‐p(laurylmethacrylate) (LMA) copolymer aggregates is able to cross the blood–brain barrier, since it affected motor behaviour in animals, which is a sensitive measure for CNS actions. Carefully designed copolymers based on the clinically approved p(HPMA) were selected and synthesized by a combination of controlled radical polymerization and post‐polymerization modification. The hydrodynamic radii (Rh) of amphiphilic p(HPMA)‐co‐p(LMA) alone and loaded with domperidone were determined by fluorescence correlation spectroscopy.

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Volume localized shift selective 13C spectroscopy using pulsed rotating frame transfer sequences with windows (PRAWN)
Authors: Banerjee Abhishek , Chandrakumar N.
Published: April 2011

Some novel techniques for volume localized, chemical shift selective 13C spectroscopy are described in this work. These techniques are based on rotating frame J cross polarization and are reported for both direct and indirect modes of 13C detection. The performance of two selective mixing sequences, viz., pulsed rotating frame transfer sequences with windows (PRAWN) and PRAWN‐π has been studied systematically with different liquid and gel phantoms. Two different front‐end modules are used for volume localization, viz., point resolved spectroscopy (PRESS) and localized distortionless enhancement by polarization transfer (LODEPT). It is shown experimentally that both the selective J cross polarization sequences can operate efficiently with very low radiofrequency duty cycle; further, they have considerable tolerance to Hartmann‐Hahn mismatch. A simple theoretical analysis is also presented to understand J cross‐polarization dynamics at low RF field amplitudes. Finally, the performance of LODEPT‐PRAWN‐π is demonstrated for the selective detection of saturated fat in pigeon egg in indirect detection mode. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Rat strain‐dependent variations in brain metabolites detected by in vivo1H NMR spectroscopy at 16.4T
Authors: Hong Sung‐Tak , Balla David Z. , Choi Changho , Pohmann Rolf
Published: April 2011

Localized in vivo 1H NMR spectroscopy is playing an increasing role in preclinical studies, because of its ability to quantify the concentrations of up to 20 metabolites in rat brain. To assess the differences between often‐used rat strains, the neurochemical profiles of Sprague‐Dawley, Wistar and Fischer rats were determined at ultrashort TE at 16.4 T. To ascertain high‐qualitative quantification, a first experiment examined the dependence of the measuring time on the quantification results and precision by precisely the number of averages between 16 and 320. It was shown that most metabolites can be quantified accurately within a short scan time, yielding Cramér–Rao lower bounds below 20% and stable concentrations for 16 metabolites with as few as 32 or 64 averages in the thalamus and hippocampus, respectively. Interstrain differences in metabolite concentrations were shown to be moderate, with taurine varying significantly between Sprague‐Dawley and Wistar rats, and slightly more distinct differences from Fischer rats, including variations in glutamate and myo‐inositol. The high spectral quality and quantification precision of all data again demonstrated the potential of in vivo 1H NMR spectroscopy at ultrahigh field. Copyright © 2011 John Wiley & Sons, Ltd.
Net reactivity index (Δω)
Authors: Chakraborty Arindam , Das Ranjita , Giri Santanab , Chattaraj Pratim Kumar
Published: April 2011

A Hammett‐type relationship has been obtained for a set of substituted benzoic acids, in terms of the net electrophilicity index. A new multiphilic descriptor, the net reactivity index (NRI) has been proposed. It can properly describe whether a Diels–Alder type reaction would follow a polar‐stepwise pathway or a non‐polar‐concerted mechanism. It can also clearly delineate whether a reaction is of normal or inverse electron demand type, in case the minimum ionization potential and the maximum electron affinity values do not belong to the same molecule in a diene–dienophile pair. Copyright © 2011 John Wiley & Sons, Ltd.
Elimination of Arcing in Reactive Sputtering of Al2O3 Thin Films Prepared by DC Pulse Single Magnetron
Authors: Meissner Michal , Tolg Tomas , Baroch Pavel , Musil Jindrich
Published: April 2011

The article reports on the elimination of arcing in the DC pulse reactive sputtering of Al2O3 thin films using a single unbalanced magnetron operating at relatively high target power density Wta ranging from ∼10 to ∼50 W/cm2; Wta is the target power density averaged over the pulse length. Correlations between pulse length τ, pulse‐off time toff, repetition frequency fr and arcing at the target surface were investigated in detail. Undesirable damage of sputtered alumina film due to arcing is demonstrated. It is shown that the length of pulse‐off time toff is of key importance for elimination of arcing in pulse reactive sputtering of electrically insulating compounds using a single magnetron.

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Internal organization of large protein families: Relationship between the sequence, structure, and function‐based clustering
Authors: Cai Xiao‐Hui , Jaroszewski Lukasz , Wooley John , Godzik Adam
Published: April 2011

The protein universe can be organized in families that group proteins sharing common ancestry. Such families display variable levels of structural and functional divergence, from homogenous families, where all members have the same function and very similar structure, to very divergent families, where large variations in function and structure are observed. For practical purposes of structure and function prediction, it would be beneficial to identify sub‐groups of proteins with highly similar structures (iso‐structural) and/or functions (iso‐functional) within divergent protein families. We compared three algorithms in their ability to cluster large protein families and discuss whether any of these methods could reliably identify such iso‐structural or iso‐functional groups. We show that clustering using profile‐sequence and profile–profile comparison methods closely reproduces clusters based on similarities between 3D structures or clusters of proteins with similar biological functions. In contrast, the still commonly used sequence‐based methods with fixed thresholds result in vast overestimates of structural and functional diversity in protein families. As a result, these methods also overestimate the number of protein structures that have to be determined to fully characterize structural space of such families. The fact that one can build reliable models based on apparently distantly related templates is crucial for extracting maximal amount of information from new sequencing projects. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Preparation and tribological properties of self‐assembled poly(amide amine)‐Cu nanofilm on silicon
Authors: Cui Baofeng , Zhang Ling , Zhou Huidi , Zhang Junyan , Chen Jianmin
Published: April 2011

Self‐assembled poly(amide amine)‐copper (PAMAM/Cu) film on silicon was prepared and investigated by means of contact angle measurement, XPS and atomic force microscopy (AFM). The tribological properties were evaluated using a reciprocal ball‐on‐disc test rig and a lateral force microscope. Results of XPS show the existence of Cu(0) and PAMAM molecule on the surface of the film. Compared with the self‐assembled monolayer of the poly(amide amine) generation 4.0 dendrimer, the friction force of PAMAM/Cu film is lower and the friction coefficient is smaller which can be attributed to the existence of Cu nanoparticles. The PAMAM/Cu film shows a good lubrication effect. The stability of friction and wear resistance of film is improved. Copyright © 2011 John Wiley & Sons, Ltd.
Homing‐pigeon‐based messaging: multiple pigeon‐assisted delivery in delay‐tolerant networks
Authors: Guo Hui , Li Jiang , Hu Rose Qingyang , Qian Yi
Published: April 2011

In this paper, we consider the applications of delay‐tolerant networks (DTNs), where the nodes in a network are located in separated areas, and in each separated area, there exists (at least) an anchor node that provides regional network coverage for the nearby nodes. The anchor nodes are responsible for collecting and distributing messages for the nodes in the vicinity. This work proposes to use a set of messengers (named pigeons) that move around the network to deliver messages among multiple anchor nodes. Each source node (anchor node or Internet access point) owns multiple dedicated pigeons, and each pigeon takes a round trip starting from its home (i.e., the source) through the destination anchor nodes and then returns home, disseminating the messages on its way. We named this as a homing‐pigeon‐based messaging (HoPM) scheme. The HoPM scheme is different from the prior schemes in that each messenger is completely dedicated to its home node for providing messaging service. We obtained the average message delay of HoPM scheme in DTN through theoretical analysis with three different pigeon scheduling schemes. The analytical model was validated by simulations. We also studied the effects of several key parameters on the system performance and compared the results with previous solutions. The results allowed us to better understand the impacts of different scheduling schemes on the system performance of HoPM and demonstrated that our proposed scheme outperforms the previous ones. Copyright © 2011 John Wiley & Sons, Ltd.
Influence of Polydimethylsiloxane on the Degradation of Soybean Oil at Frying Temperature
Authors: Gerde Jose A. , Hammond Earl G. , White Pamela J.
Published: April 2011

Soybean oils treated with 5, 10, 25, 50, and 100 ppb polydimethylsiloxane (PDMS) and a control soybean oil (no PDMS) were heated at 180 °C for 48 h. The decomposition of linoleate (18:2) and tocopherols was monitored. The degradation of 18:2 and both γ‐ and δ‐tocopherols followed pseudo first‐order kinetics. For 25 ppb PDMS (the concentration necessary to form a PDMS monolayer on the air‐oil interface) and greater concentrations, 18:2 degradation decreased at a rate comparable to the control. However, for the samples with 25 ppb or more PDMS, there was a subsequent increase in the rate of 18:2 degradation during the 48 h of heating period. The same trend seen for 18:2 degradation also was observed for the rates of degradation of both γ‐ and δ‐tocopherols; but, for the tocopherols the treatment with 10 ppb PDMS also decreased the rate of degradation. For those PDMS treatments in which a subsequent increase in degradation rates were observed, the rates of degradation after the change were similar to the rate of degradation in the control oil. In general, the time that the changes in rates occurred increased with the PDMS concentrations. The occurrence of these changes was attributed to decreases in the concentrations of tocopherols or PDMS such that the protective effects were lost.
Module structure on Lie powers and natural coalgebra-split sub-Hopf algebras of tensor algebras
Authors: Li J. Y. , Lei F. C. , Wu J.
Published: April 2011

We investigate the functors from modules to modules that occur as the summands of tensor powers and the functors from modules to Hopf algebras that occur as natural coalgebra summands of tensor algebras. The main results provide some explicit natural coalgebra summands of tensor algebras. As a consequence, we obtain some decompositions of Lie powers over the general linear groups.
“Something More Than a Drummer's Interest”: Commercial Realism inThe Rise of Silas Lapham
Authors: Spears Timothy
Published: April 2011

Amid rising interest in the history of consumer culture and the literary marketplace,The Rise of Silas Lapham(1885) gained new significance in the 1980s when scholars placed William Dean Howells, his novel, and realism as a whole in a complicated relation to 19th-century economic culture. In general, these critics found Howells retreating from an overbearing market system within which he had tried to establish realism as a truer, less sensationalized form of writing. By showing that Howells's writing was itself a market practice, their historicist readings significantly revised our understanding of American realism. At the same time, though, their interpretations tended to rely on abstract understandings of Gilded Age business culture. This essay seeks a new view ofThe Rise of Silas Laphamby focusing more concretely on the marketing techniques whose emergence after the Civil War benefited Howells's writing career but troubled his conscience. Howells's awareness of his contradictory relation to the market is most obviously manifest in the economic and moral quandary faced by Silas Lapham. But as I argue below, Howells imagined a solution to this dilemma in the form of Lapham's son-in-law, Tom Corey — a figure critics have mainly ignored. Not only does the genteel Bostonian represent the future of the paint business, but his anticipated role in international markets suggests both the expansionist and idealistic nature of Howells's realism.
Acquiring Minds: Commodified Knowledge and the Positioning of the Reader inMcClure's Magazine,1893–1903
Authors: Ryan Susan M.
Published: April 2011

In a 1900Atlantic Monthlyarticle, Samuel McChord Crothers mourns the decline of the leisured or, as he puts it, “gentle” reader who enjoys narrative digressions, does not mind occasional dullness, and prefers the personal tone of old-style narrators to the objectivity of the modern “expert.” This reader has given way, Crothers argues, to one obsessed with practicality and impatient with charming irrelevancies, one who parcels out his reading time carefully, going to short stories (rather than lengthier offerings) for “a literary ‘quick lunch.’” Though he acknowledges that “the habit of resorting to the printed page for information is an excellent one,” Crothers admits that it nevertheless violates his ideal terms of readerly engagement. The new-style reader, he laments, “wants something and knows where to get it. Knowledge is a commodity done up in a neat parcel” (655). Crothers's remarks suggest a troubling opposition – the pure realm of literature-as-enjoyment that supposedly used to exist outside of, or above, the marketplace versus the newly ascendant and tainted world of goods, advertisements, and department stores in which knowledge is packaged and sold to a hurried, grasping public. While other highbrow commentators of the era expressed a general concern regarding the decline of intellectualism among American readers, Crothers betrays more specific anxieties about what constitutes an appropriate means of absorbing (and disseminating) knowledge; he fears the intrusion of market values and forms – particularly the value of practicality and the form of the commodity – into the world of ideas.
“Departments of human feeling”:Roderick Hudson,Love, and Friendship in the Gilded Age
Authors: Nissen Axel
Published: April 2011

The extent to which American men, during most of the 19th century, could feel and openly express an unashamed, unself-conscious, all-consuming love for members of their own sex is a phenomenon that has not yet been adequately studied or explained. Although extensive work has been done on the “female world of love and ritual,” we know comparatively little of the correspondingmaleworld of love and ritual. We are only beginning to rediscover the extent, the significance, and the varieties of love between men in the 19th-century United States.
Paint for the Many? Rereading William Sidney Mount's The Painter's Triumph
Authors: Roark Elisabeth L.
Published: April 2011

The Painter's Triumph, created by William Sidney Mount in 1838, has long been interpreted as an icon of the democratization of American art (Figure 1). Nearly every scholarly analysis of the painting frames it in the context of Mount's well-known charge to himself, “Paint pictures that will take with the public, in other words, never paint for the few, but for the many.” The farmer's enthusiastic involvement in the artist's work is viewed as emblematic of Mount's commitment to promoting the visual arts among ordinary folk. The painter's “triumph,” most assert, is his ability to reach the common man. This is certainly an appealing message and consistent with the desire to see mid-19th-century American artists as resolute democrats in tune with Jacksonian cultural reforms. Yet, Mount never called it The Painter's Triumph, referring to it only as “artist showing his work,” and there is no evidence that viewers in the late 1830s and early 1840s recognized a particularly democratic message. The current title first appeared in a catalogue in 1847, long after Mount sold the painting and two years after the death of Edward L. Carey, the man who commissioned it. Despite the 1847 title change, in his later autobiographical sketch Mount referred to the painting as “Artist showing his own work.”
Collecting: The Work of Learning, Following Botanists
Authors: Knobloch Frieda
Published: April 2011

Aven Nelson (1859–1952) was a botanist at the University of Wyoming in Laramie. His second wife, Ruth Elizabeth Ashton (1896–1987), much his junior, was his partner in the field and companion in the last twenty years of his life. Separately and in each other's company, these naturalists brought work, play, learning, and companionship together fairly seamlessly in their lives. This is an enviable accomplishment in a world where most of us compartmentalize all things — work separate from play, indoors from outdoors, emotional experience from professional effort — and few people ask seriously how any of these aspects of a life in progress might inform one another over time. But, like many different kinds of professionals, neither of the Nelsons wrote about the specific conditions of their work — in their case, what it was like to work outdoors, what the plants they collected made them think about, or what it was like to work together, though it is clear enough they enjoyed themselves, and both of them sustained long productive lives in close communication with colleagues and the natural world.
Charles Mathews and His “A Trip to America”
Authors: Blair Walter
Published: April 2011

Charles Mathews (1776–1835), the outstanding British comedian of his day, toured America between September, 1822, and the following May. In addition to appearing onstage in the northeast, he collected materials for a one-man dramatic entertainment, “A Trip to America.” Nine months after he returned to England, he opened a three-and-a-half-hour performance of this dramatization, using a script that he and playwright James Smith wrote. Mathews performed this piece many times in London and the provinces, and in 1834 took it to the United States.
Majority Images-Minority Realities: A Perspective on Anti-Orientalism in the United States
Authors: Daniels Roger
Published: April 2011

The final American withdrawal from Vietnam and the collapse of our client regime in Saigon marked a nodal point in American relations with East Asia. For years prior to our terminal disengagement, hawkish politicians and publicists had waxed eloquent about the bloodbath that was sure to occur when the northerners and their allies of the People's Revolutionary Government had achieved their victory. Although that sanguinary catastrophe did not occur, the presumption that it could have caused the American government to implement and execute a refugee program that brought over 125,000 Vietnamese to the United States. While it is far too early to draw up any detailed balance sheet on that refugee program, the reactions that it triggered in the United States provide a useful and convenient point of departure for a retrospective analysis of changing American attitudes toward all immigrants from Asia.
Landmarks of “The Terrible Town”: The New York Scene in Henry James' Last Stories
Authors: Tintner Adeline R.
Published: April 2011

A tremendous amount of material has been written about the overpowering effect that America had on Henry James when he returned to this country in 1904 after twenty-years absence, which he discussed in The American Scene (1907). In particular, the effects of the New York scene, what James called the “terrible town,” are recorded in his New York Stories—“The Jolly Corner,” “Julia Bride,” “Crapy Cornelia,” and “A Round of Visits”—written between 1906 and 1909, and “The Married Son,” Chapter Seven from the composite novel, The Whole Family (1908).