bluuebunny/crossref_metadata_2025 huggingface dataset:
Report of two patients and further characterization of interstitial 9p13 deletion—A rare but recurrent microdeletion syndrome?
Authors: Niemi Anna‐Kaisa , Kwan Andrea , Hudgins Louanne , Cherry Athena M. , Manning Melanie A.
Published: August 2012

To date, an interstitial deletion of 9p13 has been described only two times in the medical literature. These reports were based on routine chromosomal analysis. We report on two additional patients with an interstitial deletion of 9p13 further defined on array CGH who share clinical features with the other two patients previously described. Our first patient is a 16‐year‐old girl with a 5.9 Mb deletion at 9p13.3–9p13.1, initially detected on routine karyotype analysis and further characterized on array CGH. Our second patient is a 7½‐year‐old boy with a 4.8 Mb deletion also at 9p13.3–9p13.1. Patients with 9p13 deletion appear to have mild to moderate developmental delay, social and interactive personality, behavior issues such as attention deficit‐hyperactivity disorder, short stature, prominent antihelices, hypoplastic nails, and precocious/early puberty. Our 16‐year‐old patient is the oldest patient described thus far. This report further characterizes this condition and helps to delineate the long‐term prognosis in these patients. © 2012 Wiley Periodicals, Inc.
Phenotype in novel Xp duplication
Authors: Salaria Manju , Burgess Trent , Setyapranata Stella , Winship Ingrid
Published: August 2012

A novel duplication of Xp is described. A 20‐year‐old man had minor anomalies ichthyosis, congenital heart defect, varicose veins, and hypogonadotropic hypogonadism. He had an interstitial duplication of approximately 2.8 Mb from chromosome region Xp22.31p22.2. His similarly affected brother and asymptomatic mother were shown to carry the same duplication. Knowledge about this duplication and its resultant phenotype will add to our understanding of the role of X chromosome duplications. © 2012 Wiley Periodicals, Inc.
CD44+ cells have cancer stem cell–like properties in nasopharyngeal carcinoma
Authors: Janisiewicz Agnieszka M. , Shin June Ho , Murillo‐Sauca Oihana , Kwok Shirley , Le Quynh‐Thu , Kong Christina , Kaplan Michael J. , Sunwoo John B.
Published: August 2012

Background:

A subpopulation of cells within a tumor appears to have the exclusive ability to initiate tumors, self‐renew, and differentiate. These “cancer stem cells” (CSCs) are CD44+ in several epithelial malignancies. We examined the potential of CD44 to identify the CSC population in nasopharyngeal carcinoma (NPC).

Methods:

C666, an Epstein‐Barr virus–positive (EBV+) human NPC cell line, was stained for CD44 and sorted by fluorescence‐activated cell sorting (FACS). CD44+ and CD44− subpopulations were evaluated for (1) proliferative potential, (2) ability to differentiate, (3) expression of markers of epithelial‐to‐mesenchymal transition (EMT) and EBV genes, and (4) the ability to initiate tumors in vivo. Immunocompromised mice were injected with CD44+ and CD44− populations to assess the tumor‐initiating capacity. Immunohistochemistry for CD44 was performed on an 87‐patient tissue microarray (TMA), and clinical correlations were examined.

Results:

Heterogeneous expression of CD44 was seen among C666 cells. CD44+ cells differentiated into CD44− cells, indicating a hierarchical relationship. Further, CD44+ cells exhibited a more robust tumor‐initiating capacity in the xenograft model. However, no differences were seen in proliferation rates in vitro, EBV gene expression, or expression of EMT markers between CD44+ and CD44− subsets. Patient tumors were heterogeneous for CD44 staining, and a trend toward an association between CD44 expression and clinical outcome was observed.

Conclusion:

NPC contains a CD44+ subpopulation with features consistent with CSCs. There was a trend toward an association between CD44 expression within NPC tumors and decreased time to local failure/relapse in patients. © 2012 ARS–AAOA, LLC.
Neuropathy‐associated NaV1.7 variant I228M impairs integrity of dorsal root ganglion neuron axons
Authors: Persson Anna‐Karin , Liu Shujun , Faber Catharina G. , Merkies Ingemar S. J. , Black Joel A. , Waxman Stephen G.
Published: August 2012

Small‐fiber neuropathy (SFN) is characterized by injury to small‐diameter peripheral nerve axons and intraepidermal nerve fibers (IENF). Although mechanisms underlying loss of IENF in SFN are poorly understood, available data suggest that it results from axonal degeneration and reduced regenerative capacity. Gain‐of‐function variants in sodium channel NaV1.7 that increase firing frequency and spontaneous firing of dorsal root ganglion (DRG) neurons have recently been identified in ∼30% of patients with idiopathic SFN. In the present study, to determine whether these channel variants can impair axonal integrity, we developed an in vitro assay of DRG neurite length, and examined the effect of 3 SFN‐associated variant NaV1.7 channels, I228M, M932L/V991L (ML/VL), and I720K, on DRG neurites in vitro. At 3 days after culturing, DRG neurons transfected with I228M channels exhibited ∼20% reduced neurite length compared to wild‐type channels; DRG neurons transfected with ML/VL and I720K variants displayed a trend toward reduced neurite length. I228M‐induced reduction in neurite length was ameliorated by the use‐dependent sodium channel blocker carbamazepine and by a blocker of reverse Na‐Ca exchange. These in vitro observations provide evidence supporting a contribution of the I228M variant NaV1.7 channel to impaired regeneration and/or degeneration of sensory axons in idiopathic SFN, and suggest that enhanced sodium channel activity and reverse Na‐Ca exchange can contribute to a decrease in length of peripheral sensory axons. Ann Neurol 2012
Funktionalisierung von C‐H‐Bindungen: neue Synthesemethoden für Naturstoffe und Pharmazeutika
Authors: Yamaguchi Junichiro , Yamaguchi Atsushi D. , Itami Kenichiro
Published: August 2012

Die direkte Funktionalisierung von C‐H‐Bindungen in organischen Molekülen hat sich in jüngster Zeit zu einer wirksamen und idealen Methode entwickelt, mit der Kohlenstoff‐Kohlenstoff‐ und Kohlenstoff‐Heteroatom‐Bindungen geknüpft werden können. Der Aufsatz gibt einen Überblick über die Strategien, die durch Funktionalisierung von C‐H‐Bindungen eine rasche Synthese von biologisch aktiven Verbindungen wie Naturstoffen und pharmazeutischen Zielsubstanzen ermöglichen.
Die phantastische Reise: Nanoroboter mit Eigenantrieb
Authors: Sengupta Samudra , Ibele Michael E. , Sen Ayusman
Published: August 2012

Nanoroboter, die scheinbar wundersame Aufgaben ausführen, kennen wir aus dem Reich der Science‐Fiction.1 Obwohl natürlich Vieles davon immer Fiktion bleiben wird, haben Wissenschaftler einige der physikalischen Herausforderungen, die mit dem Betrieb von Funktionseinheiten auf kleinster Skala einhergehen, überwunden und die erste Generation von autonomen energieautarken Nanomotoren und Nanopumpen entwickelt. Diese Motoren können durch chemische und Lichtgradienten gelenkt werden, Fracht aufnehmen und transportieren und kollektives Verhalten zeigen.
The Development of Better Photocatalysts through Composition‐ and Structure‐Engineering
Authors: Zhang Dieqing , Li Guisheng , Li Hexing , Lu Yunfeng
Published: August 2012

Semiconductor photocatalysts that can effectively utilize solar irradiation hold great potential for harnessing renewable‐energy sources, as well as for environmental protection and ‐remediation. Exploring advanced photocatalysts that have improved performance has been a central theme in photocatalysis research. Herein, we review the recent developments in the design‐ and fabrication of photocatalysts with an emphasis on composition‐ and structural control over multiple length scales. This Focus Review will be of value for researchers in the area of photocatalysis, in particular, in the aspects of material design that lead to the synthesis of better photocatalysts.
Model‐based high‐throughput process development for chromatographic whey proteins separation
Authors: Nfor Beckley K. , Ripić Jovana , van der Padt Albert , Jacobs Marc , Ottens Marcel
Published: August 2012

In this study, an integrated approach involving the combined use of high‐throughput screening (HTS) and column modeling during process development was applied to an industrial case involving the evaluation of four anion‐exchange chromatography (AEX) resins and four hydrophobic interaction chromatography (HIC) resins for the separation of whey proteins having close pIs. From the HTS data, one resin of each type was selected (Capto Q and Octyl Sepharose 4 FF). Next, batch uptake experiments were performed to determine the adsorption isotherms of the major whey proteins on the selected resins, followed by isotherm parameters regression. Using the obtained isotherm parameters, the candidate chromatographic operations were modeled and experimentally validated. Finally, these were model‐optimized and evaluated based on their optimized performances. In this example, Capto Q performed much better than Octyl Sepharose 4 FF in terms of column capacity, loading, throughput and productivity; hence, Capto Q was selected as the resin of choice for whey proteins separation. This operation was further scaled up from the lab scale (1 mL) to a preparative scale (35 L), with reproducible column elution profile. By this approach, a much wider space of operating variables could be investigated, thereby increasing the chances of finding the ideal operating conditions while keeping experimentation to the minimum.
Glutamine (Q)‐peptide screening for transglutaminase reaction using mRNA display
Authors: Lee Jae‐Hun , Song Changhyeon , Kim Do‐Hyun , Park Il‐Hyang , Lee Sun‐Gu , Lee Yoon‐Sik , Kim Byung‐Gee
Published: August 2012

Information on subsite specificity of the transglutaminase (TG) is important to design any specific peptides for TG's applications and inhibitor studies. Here, mRNA display was introduced for identifying the subsite specificity of TG from Streptomyces mobaraensis (STG). Functionally active peptides expressed from mRNA display library were differentially conjugated to hexa lysine (K6)—beads according to their relative activities for STG. The active peptide substrates for STG were enriched through six rounds of screening, and its corresponding cDNA/mRNA sequences were identified by DNA sequencing. The results showed that tripeptides such as LQQ and TQP do not show any activity for STG, but the minimum size of the peptide displaying STG activity is pentapeptide. One such predicted peptide sequence, that is, RLQQP (TQ1), showed higher reactivity (ca. 182% conjugation yield) to STG than that of the highly active sequence, that is, control‐Q (PQPQLPYPQPQLPY), well‐known previously for mammalian TG2. Furthermore, when recombinant DsRed was tagged with TQ1 sequence at its C‐terminal, DsRed‐TQ1 underwent efficient covalent‐immobilization onto alginate–gelatin bead by STG reaction, showing a Q‐peptide application as a useful tagging molecule. Biotechnol. Bioeng. 2013; 110: 353–362. © 2012 Wiley Periodicals, Inc.
Engineered catalytic biofilms for continuous large scale production of n‐octanol and (S)‐styrene oxide
Authors: Gross Rainer , Buehler Katja , Schmid Andreas
Published: August 2012

This study evaluates the technical feasibility of biofilm‐based biotransformations at an industrial scale by theoretically designing a process employing membrane fiber modules as being used in the chemical industry and compares the respective process parameters to classical stirred‐tank studies. To our knowledge, catalytic biofilm processes for fine chemicals production have so far not been reported on a technical scale. As model reactions, we applied the previously studied asymmetric styrene epoxidation employing Pseudomonas sp. strain VLB120ΔC biofilms and the here‐described selective alkane hydroxylation. Using the non‐heme iron containing alkane hydroxylase system (AlkBGT) from P. putida Gpo1 in the recombinant P. putida PpS81 pBT10 biofilm, we were able to continuously produce 1‐octanol from octane with a maximal productivity of 1.3 g L day−1 in a single tube micro reactor. For a possible industrial application, a cylindrical membrane fiber module packed with 84,000 polypropylene fibers is proposed. Based on the here presented calculations, 59 membrane fiber modules (of 0.9 m diameter and 2 m length) would be feasible to realize a production process of 1,000 tons/year for styrene oxide. Moreover, the product yield on carbon can at least be doubled and over 400‐fold less biomass waste would be generated compared to classical stirred‐tank reactor processes. For the octanol process, instead, further intensification in biological activity and/or surface membrane enlargement is required to reach production scale. By taking into consideration challenges such as biomass growth control and maintaining a constant biological activity, this study shows that a biofilm process at an industrial scale for the production of fine chemicals is a sustainable alternative in terms of product yield and biomass waste production. Biotechnol. Bioeng. 2013; 110: 424–436. © 2012 Wiley Periodicals, Inc.
Combined treatment of Pseudomonas aeruginosa biofilms with bacteriophages and chlorine
Authors: Zhang Yanyan , Hu Zhiqiang
Published: August 2012

Bacterial biofilms are a growing concern in a broad range of areas. In this study, a mixture of RNA bacteriophages isolated from municipal wastewater was used to control and remove biofilms. At the concentrations of 400 and 4 × 107 PFU/mL, the phages inhibited Pseudomonas aeruginosa biofilm formation by 45 ± 15% and 73 ± 8%, respectively. At the concentrations of 6,000 and 6 × 107 PFU/mL, the phages removed 45 ± 9% and 75 ± 5% of pre‐existing P. aeruginosa biofilms, respectively. Chlorine reduced biofilm growth by 86 ± 3% at the concentration of 210 mg/L, but it did not remove pre‐existing biofilms. However, a combination of phages (3 × 107 PFU/mL) and chlorine at this concentration reduced biofilm growth by 94 ± 2% and removed 88 ± 6% of existing biofilms. In a continuous flow system with continued biofilm growth, a combination of phages (a one‐time treatment at the concentration of 1.9 × 108 PFU/mL for 1 h first) with chlorine removed 97 ± 1% of biofilms after Day 5 while phage and chlorine treatment alone removed 89 ± 1% and 40 ± 5%, respectively. For existing biofilms, a combined use of a lower phage concentration (3.8 × 105 PFU/mL) and chlorination with a shorter time duration (12 h) followed by continuous water flushing removed 96 ± 1% of biofilms in less than 2 days. Laser scanning confocal microscopy supplemented with electron microscopy indicated that the combination treatment resulted in biofilms with lowest cell density and viability. These results suggest that the combination treatment of phages and chlorine is a promising method to control and remove bacterial biofilms from various surfaces. Biotechnol. Bioeng. 2013; 110: 286–295. © 2012 Wiley Periodicals, Inc.
Improvement of Photorhabdus temperata bioinsecticides production in low‐cost media through adequate fermentation technology
Authors: Jallouli Wafa , Jaoua Samir , Zouari Nabil
Published: August 2012

To develop a cost effective process for bioinsecticides production by Photorhabdus temperata, dissolved oxygen (DO) requirements were investigated in both the complex and the optimized media using diluted seawater as a source of micronutrients. By varying DO concentrations, tolerance to hydrogen peroxide was shown to be medium dependant. Indeed, P. temperata cells grown in the complex medium, exhibited higher tolerance than cells grown in the optimized medium (OM). Tolerance to H2O2 was shown to be related to intracellular reactive oxygen species (ROS) accumulation during soya bean meal or glucose assimilation, as shown by flow cytometry analysis. To avoid oxidative stress damages in P. temperata cells cultured in the OM, DO concentration should be constant 50% saturation throughout the fermentation. However, a DO‐shift control strategy was demonstrated to be beneficial for P. temperata bioinsecticide production in the complex medium. By using such a strategy biomass, culturability, and oral toxicity reached 16.5 × 108, 1.15 × 108 cells/mL and 64.2%, respectively, thus was 16.19, 26.37, and 12.2% more than in the cultures carried out at a constant 50% saturation. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Recycling CO2? Computational Considerations of the Activation of CO2 with Homogeneous Transition Metal Catalysts
Authors: Drees Markus , Cokoja Mirza , Kühn Fritz E.
Published: August 2012

Faced with depleting fossil carbon sources, the search for alternative energy carriers and energy storage possibilities has become an important issue. Nature utilizes carbon dioxide as starting material for storing sun energy in plant hydrocarbons. A similar approach, storing energy from renewable sources in chemical bonds with CO2 as starting material, may lead to partial recycling of CO2 created by human industrial activities. Unfortunately, currently available routes for the transformation of CO2 involve high temperatures and are often not selective. With the development of more sophisticated methods and better software, theoretical studies have become both increasingly widespread and useful. This concept article summarizes theoretical investigations of the current state of the feasibility of CO2 activation with molecular transition metal catalysts, highlighting the most promising reactions of CO2 with olefins to industrially relevant acrylic acid/acrylates, and the insertion of CO2 into metal–element bonds, particularly for the synthesis of cyclic carbonates and polymers. Rapidly improving computational power and methods help to increase the importance and accuracy of calculations continuously and make computational chemistry a useful tool helping to solve some of the most important questions for the future.
Electrode‐driven Regioselective Oxidation of Cinnamyl Alcohol by use of Thin Biologically Active Chloroperoxidase Composite Films
Authors: Tian Haitao , Mu Shilei , Li Hexing , Wu Xiaqin , Lu Zhongqing
Published: August 2012

We report an electrochemical system consisting of a modified glassy carbon (GC) electrode made from chitosan (Chi), chloroperoxidase (CPO), didodecyldimethylammonium bromide (DDAB) and Nafion for the bio‐electrocatalytic oxidation of cinnamyl alcohol. The CPO‐containing composite films were characterized and qualified by SEM, AFM, and cyclic voltammetry prior to synthesis applications. The thin Chi‐DDAB‐CPO composite film modified electrode gave a pair of well‐defined, quasi‐reversible redox peaks for CPO with an electron transfer rate of 2.3 s−1. The SEM and atomic force microscopy results obtained suggest that CPO in the thin film aggregated to form island‐like structures with sizes from 300 to 1000 nm and the average film thickness was 30 nm. Unlike conventional biological systems requiring external addition of excess H2O2, a controllable amount of H2O2 was continuously generated in the electrochemical system containing the CPO modified electrode. Almost all H2O2 generated in situ was used for catalytic oxidation of cinnamyl alcohol by CPO in the composite films. In addition, the stability and the lifetime of CPO composite films were improved significantly by coating a chitosan layer on the CPO layer. The preliminary results obtained for oxidation of cinnamyl alcohol using our electrochemical system gave a total yield of 51.8 % in contrast to 7.6 % for the conventional biological system with consumption of the same amount of enzyme. The Chi‐DDAB‐CPO‐Nafion films showed a total turnover number [molproduct molenzyme catalyst−1 (TTN)] of 80 500, 5‐fold more than those reported for oxidation of primary alcohols.
Architecture of PtCo Bimetallic Catalysts for Catalytic CO Oxidation
Authors: Xu Hong , Fu Qiang , Guo Xiaoguang , Bao Xinhe
Published: August 2012

PtCo nanocatalysts have been synthesized and tested for both preferential oxidation of CO in excess H2 (PROX) and CO oxidation in the absence of H2 (COOX). Structural characterization and reaction results suggest that a PtCo catalyst architecture consisting of Pt nanoparticles decorated with highly dispersed CoO nanostructures is the active structure for both reactions. The highly active “CoO‐on‐Pt” catalysts can be prepared by reduction of as‐prepared PtCo catalysts at an intermediate temperature or by reactivation of an acid‐leached PtCo catalyst at a similar temperature. A comparative study of PtFe, PtCo, and PtNi catalysts reveals that interface confinement effects are dominant in all “TMOx‐on‐Pt” systems (TM=Fe, Co, and Ni). However, the activity and stability in both PROX and COOX reactions for each of these catalyst systems is variable.
Novel Single Stage Wash Sedimentator for Purification and Separation of Small Particles
Authors: Anlauf H. , Jeras J. , Feist M. , Scheffler J. , Nussbaumer M.
Published: August 2012

The starting point for the development of a novel process for simultaneous washing and separation of fine particles was the task of removing accompanying impurities from a crystallized plant extract and separating the crystals in a purified form. For this purpose, an innovative technical concept was developed, fundamental aspects were investigated on a laboratory scale, and the process was successfully carried out on a pilot scale in a joint project. In principle, the new method is based on a static sedimentation apparatus with integrated countercurrent washing, which operates continuously and produces a purified solid concentrate.
Development of 1‐Hydroxy‐2(1H)‐quinolone‐Based Photoacid Generators and Photoresponsive Polymer Surfaces
Authors: Ikbal Mohammed , Banerjee Rakesh , Atta Sanghamitra , Jana Avijit , Dhara Dibakar , Anoop Anakuthil , Singh N. D. Pradeep
Published: August 2012

A new class of carboxylate and sulfonate esters of 1‐hydroxy‐2(1H)‐quinolone has been demonstrated as nonionic photoacid generators (PAGs). Irradiation of carboxylates and sulfonates of 1‐hydroxy‐2(1H)‐quinolone by UV light (λ≥310 nm) resulted in homolysis of weak NO bond leading to efficient generation of carboxylic and sulfonic acids, respectively. The mechanism for the homolytic NO bond cleavage was supported by time‐dependent DFT calculations. Photoresponsive 1‐(p‐styrenesulfonyloxy)‐2‐quinolone–methyl methacrylate (SSQL‐MMA) and 1‐(p‐styrenesulfonyloxy)‐2‐quinolone–lauryl acrylate (SSQL‐LA) copolymers were synthesized from PAG monomer 1‐(p‐styrenesulfonyloxy)‐2‐quinolone, and subsequently controlled surface wettability was demonstrated for the above‐mentioned photoresponsive polymers.
Large‐Scale and Facile Preparation of Pure Ammonia Borane through Displacement Reactions
Authors: Chen Xuenian , Bao Xiaoguang , Billet Beau , Shore Sheldon G. , Zhao Ji‐Cheng
Published: August 2012

Ammonia borane (AB) is the most widely studied hydride for hydrogen storage in addition to being a useful reducing agent. Attempts to synthesize pure AB through simple displacement reactions date back to the 1960s; but have been thwarted by the formation of the diammoniate of diborane (DADB), an ionic byproduct. Based on our recent characterization of the formation mechanism of DADB, we have developed a large‐scale synthesis of pure AB by both increasing the basicity of the Lewis base of the borane carrier and using a nonpolar solvent to limit the formation of an intermediate, the ammonia diborane (AaDB). Conditions were optimized for the preparation of pure AB by two displacement reactions, either ammonia with dimethylsulfide borane or ammonia with dimethylaniline borane in toluene at room temperature. These procedures are also suitable for preparation of other amine boranes which had the same problem of forming ionic byproducts during displacement reactions.
Further Examples of the P‐O‐P Connection in Borophosphates: Synthesis and Characterization of Li2Cs2B2P4O15, LiK2BP2O8, and Li3M2BP4O14 (M=K, Rb)
Authors: Wang Ying , Pan Shilie , Shi Yunjing
Published: August 2012

A new series of anhydrous mixed alkali‐metal borophosphates—Li2Cs2B2P4O15 (1), LiK2BP2O8 (2), Li3K2BP4O14 (3), and Li3Rb2BP4O14 (4)—have been successfully synthesized by using the conventional solid‐state reaction method. Compound 1 contains a novel fundamental building unit (FBU), [B4P8O30], with B/P=1:2. Compound 2 contains an FBU of [B2P4O16] with B/P=1:2. Compounds 3 and 4 are isotypic, and they have a [B(P2O7)2] unit as their FBU. In all four compounds, their FBUs are connected through corner sharing to generate layered anionic partial structures, and then further linked with metallic polyhedra to form three‐dimensional (3D) frameworks. Most interestingly, three of the four compounds contain direct P‐O‐P connections in their structures, which is extremely rare among borophosphates. Thermal analyses, IR spectroscopy, and UV/Vis/near‐IR diffuse reflectance spectroscopy have also been performed on the four title compounds.
Polyin eingefädelt
Authors: Groß Michael
Published: August 2012

Erstmals ist es gelungen, längere Polyine durch einen molekularen Ring zu fädeln. Dies ist ein erster Schritt zur Untersuchung einer neuen Kohlenstoffmodifikation und auch zur Herstellung von isolierten molekularen Drähten.
Heat transfer and flow pattern in co‐current downward steam condensation in vertical pipes‐I: CFD simulation and experimental measurements
Authors: Dahikar Sachin K. , Ganguli Arijit A. , Gandhi Mayurkumar S. , Joshi Jyeshtharaj B. , Vijayan Pallippattu K.
Published: August 2012

The condensation of pure steam flowing inside a vertical tube has been extensively studied during the last nine decades. Considerable amount of experimental and analytical efforts can be found due to the significance of this subject in practice. In the present work (Part I), experimental investigations have been performed over a range of pressure (0.1 < P < 0.35 MPa) and internal tube diameter (Di = 10, 20 and 43 mm). A two‐dimensional computational fluid dynamic (CFD) simulations have been carried out commercial software Fluent 6.2 [Fluent 6.2, “User's Manual to FLUENT 6.2,” Fluent Inc., Lebanon, USA, 2005]. CFD results were used to predict the temperature profiles, pressure drop and the heat transfer coefficient, which was in close agreement with the experimental values. The film characteristics predicted by the CFD simulations have been compared qualitatively with the photographic images. Further, the CFD model developed in Part I extended for the analysis of all the experimental data reported in the published literature. © 2012 Canadian Society for Chemical Engineering
Use of vinasse to produce slow‐release coated urea in spouted bed
Authors: da Rosa Gabriela Silveira , dos Santos Rocha Sandra Cristina
Published: August 2012

The aim of this work was to evaluate the influence of the operating conditions on the coating efficiency for urea coated in a spouted bed and to analyse the decrease of nitrogen volatilisation for the coated urea. Coating efficiencies in the range (from 44.24% to 73.7%) were obtained for the different process conditions applied. Volatilisation analyses showed that the polymer film coating provided a decrease of the nitrogen loss in the range from 3% to 57%. The use of vinasse in substitution to the water in the coating suspension was tested for the optimum process conditions. © 2012 Canadian Society for Chemical Engineering
Targeting tyrosine kinases in cancer
Authors: Dumur Catherine I. , Idowu Michael O. , Powers Celeste N.
Published: August 2012

Because of knowledge gained in the field of cancer biology, clinicians are currently witnessing an explosion of molecular tests as companion diagnostics to targeted therapies against growth factor receptors and their signaling pathways. Such tests are being applied increasingly to cytology specimens as essential components of genomic medicine, because less invasive diagnostic procedures are becoming the norm. The objective of this review was to present an overview of the current and future role of cytopathology in molecular diagnostics, including the adequacy of cytology specimens for such studies. The authors also discuss the critical methodologic aspects of the molecular assays used for the selection of tyrosine kinase treatment for oncology patients. Cancer (Cancer Cytopathol) 2013. © 2012 American Cancer Society.
Intricate paths of cells and networks becoming “Cholinergic” in the embryonic chicken retina
Authors: Thangaraj Gopenath , Greif Alexander , Bachmann Gesine , Layer Paul G.
Published: August 2012

Choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) are the decisive enzymatic activities regulating the availability of acetylcholine (ACh) at a given synaptic or nonsynaptic locus. The only cholinergic cells of the mature inner retina are the so‐called starburst amacrine cells (SACs). A type‐I SAC, found at the outer border of the inner plexiform layer (IPL), forms a synaptic subband “a” within the IPL, while a type‐II SAC located at the inner IPL border projects into subband “d.” Applying immunohistochemistry for ChAT and AChE on sections of the chicken retina, we here have revealed intricate relationships of how retinal networks became dominated by AChE or by ChAT reactivities. AChE+ cells were first detectable in an embryonic day (E)4 retina, while ChAT appeared 1 day later in the very same cells; at this stage all are Brn3a+, a marker for ganglion cells (GCs). On either side of a faint AChE+ band, indicating the future IPL, pairs of ChAT+/AChE−/Brn3a− cells appeared between E7/8. Type‐I cells had increased ChAT and lost AChE; type‐II cells presented less ChAT, but some AChE on their surfaces. Direct neighbors of SACs tended to express much AChE. Along with maturation, subband “a” presented more ChAT but less AChE; in subband “d” this pattern was reversed. In conclusion, the two retinal cholinergic networks segregate out from one cell pool, become locally opposed to each other, and become dominated by either synthesis or degradation of ACh. These “cholinergic developmental divergences” may also have significant physiologic consequences. J. Comp. Neurol., 520:3181–3193, 2012. © 2012 Wiley Periodicals, Inc.
A comparison of the Cray XMT and XMT‐2
Authors: Bokhari Shahid H. , Bokhari Saniyah S.
Published: August 2012

We explore the comparative performance of the Cray XMT and XMT‐2 massively multithreaded supercomputers. We use benchmarks to evaluate memory accesses for various types of loops. We also compare the performance of these machines on matrix multiply and on three previously implemented dynamic programming algorithms. It is shown that the relative performance of these machines is dependent on the size (number of processors) of the configuration, as well as the size of the problem being evaluated. In particular, small configurations of the original XMT can sometimes show slightly better performance than larger configurations of the XMT‐2, for the same problem size. We note that, under heavy memory load, performance of loops can saturate well before the maximum number of processors available. This suggests that it may not always be useful to use the maximum number of processors for a specific run. We also show that manual restructuring of nested loops, including decreasing the parallelism, can result in major improvements in performance. The results in this paper indicate that careful exploration of the space of problem sizes, number of processors used, and choices of loop parallelization can yield substantial improvements in performance. These improvements can be very significant for production codes that run for extended periods of time. Copyright © 2012 John Wiley & Sons, Ltd.
Hyperfine Coupling Constants of β‐Phosphorylated Nitroxides: A Tool to Probe the Cybotactic Effect by Electron Paramagnetic Resonance
Authors: Audran Gérard , Brémond Paul , Marque Sylvain R. A. , Obame Germain
Published: August 2012

Nitrogen hyperfine coupling constants (hcc) aN of nitroxides measured by electron paramagnetic resonance are used to probe the cybotactic effect of solvents. A few articles (Janzen et al., Can. J. Chem. in 1982 for aHβ and Deng et al., J. Fluorine Chem. in 2002, both for aHβ and aFβ) dealt with the cybotactic effect on the hcc of atoms (hydrogen H, fluorine F, and phosphorus P) in β positions of nitroxides. They show either no significant change or an increase in aβ with aN. However, an early report by Il′Yasov et al. (Theor. Exp. Chem. 1976, 656) described a dramatic change in aPβ with the solvent and an anti‐correlation of aPβ with aN. We decided to reinvestigate that work using the N‐(2‐methylpropyl)‐N‐(1‐diethylphosphono‐2,2‐dimethylpropyl)‐N‐oxyl radical that carries both hydrogen and phosphorus atoms on the same carbon attached to the nitroxy moiety and that is highly persistent, in contrast to the nitroxide used by Il′Yasov. We observe the same trends as those observed by Il′Yasov, except that the solvent cybotactic effect on aN and aPβ is dramatically weaker in our case. We showed that aPβ is correlated to both the cohesive pressure c and the normalized Reichardt polar constant ETN, and that hydrogen‐bonding donor solvents exhibit a specific behavior.
The Adsorption of Oxygen and Coadsorption of CO and Oxygen on Structurally Well‐Defined PdAg Surface Alloys
Authors: Farkas Arnold P. , Diemant Thomas , Bansmann Joachim , Behm R. Jürgen
Published: August 2012

The dissociative interaction of oxygen with structurally well‐defined monolayer PdxAg1−x/Pd(111) surface alloys of different compositions, with well‐known distributions of the respective surface atoms (A. K. Engstfeld et al., Phys. Chem. Chem. Phys. 2012, 14, 10754–10761), and the coadsorption of/reaction with CO on oxygen pre‐covered surfaces were studied by high‐resolution electron energy loss spectroscopy (HREELS) and temperature‐programmed desorption/reaction spectroscopy (TPD/TPR). The impact of geometric ensemble effects as well as electronic ligand and strain effects on the adsorption and reaction behaviour of the respective species on the bimetallic surfaces is elucidated and compared with related systems such as CO adsorption on similar surfaces and oxygen adsorption on a Pd67Ag33(111) bulk alloy surface. The data show a clear dominance of ensemble effects on the oxygen adsorption and CO coadsorption behaviour, with oxygen adsorption limited to threefold‐hollow sites on Pd3 sites, while the combined electronic effects, as evident from modifications in the adsorption and reaction characteristics on the Pd sites, are small.
Lowering Energy Barriers in Surface Reactions through Concerted Reaction Mechanisms
Authors: Sakong Sung , Mosch Christian , Lozano Ariel , Busnengo H. Fabio , Groß Axel
Published: August 2012

Any technologically important chemical reaction typically involves a number of different elementary reaction steps consisting of bond‐breaking and bond‐making processes. Usually, one assumes that such complex chemical reactions occur in a step‐wise fashion where one single bond is made or broken at a time. Using first‐principles calculations based on density functional theory we show that the barriers of rate‐limiting steps for technologically relevant surface reactions are significantly reduced if concerted reaction mechanisms are taken into account.
Quasi‐Homogeneous Oxidation of Glycerol by Unsupported Gold Nanoparticles in the Liquid Phase
Authors: Skrzyńska Elżbieta , Ftouni Jamal , Girardon Jean‐Sébastien , Capron Mickaël , Jalowiecki‐Duhamel Louise , Paul Jean‐François , Dumeignil Franck
Published: August 2012

A quasi‐homogeneous solution of gold nanoparticles prepared by the Turkevich method was used as an unconventional catalyst in the oxidation of glycerol (GLY) in the liquid phase. The highest obtained conversion was 100 % after 3 h of reaction at 100 °C under an oxygen atmosphere (5 bar). The main products were glyceric, glycolic, formic, tartronic, and oxalic acid with selectivities of 28, 36, 25, 9, and 2 %, respectively. Traces of hydroxypyruvic and acetic acid were also detected (combined selectivities below 1 %). To elucidate the reaction mechanism and specify the role of gold nanoparticles in the oxidation process, a series of experiments under various reaction conditions were carried out. The effect of reaction temperature, oxygen pressure, gold concentration, and GLY/base molar ratio was investigated. All catalytic results were systematically compared to the corresponding noncatalytic base‐induced transformations (blank tests). Such an approach allowed us to separate and clarify the respective driving parameters for the transformation of GLY (presence of a base and activity of the gold catalyst). The reaction mechanism comprised a series of oxidation and CC cleavage reactions, whereas additional oxidation–reduction reactions (of the Cannizzaro type) could also occur in the presence of the base.
Electron‐Rich Anthracene Semiconductors Containing Triarylamine for Solution‐Processed Small‐Molecule Organic Solar Cells
Authors: Choi Hyeju , Ko Haye Min , Cho Nara , Song Kihyung , Lee Jae Kwan , Ko Jaejung
Published: August 2012

New electron‐rich anthracene derivatives containing triarylamine hole stabilizers, 2,6‐bis[5,5′‐bis(N,N′‐diphenylaniline)‐2,2′‐bithiophen‐5‐yl]‐9,10‐bis‐[(triisopropylsilyl)ethynyl]anthracene (TIPSAntBT–TPA) and 2,6‐bis(5,5′‐bis{4‐[bis(9,9‐dimethyl‐9H‐fluoren‐2‐yl)amino]phenyl}‐2,2′‐bithiophen‐5‐yl)‐9,10‐bis‐[(triisopropylsilyl)ethynyl]anthracene (TIPSAntBT–bisDMFA), linked with π‐conjugated bithiophene bridges, were synthesized and their photovoltaic characteristics were investigated in solution‐processed small‐molecule organic solar cells (SMOSCs). These new materials exhibited superior intramolecular charge transfer from triarylamine to anthracene, leading to a more electron‐rich anthracene core that facilitated electron transfer into phenyl‐C61‐butyric acid methyl ester. Compared with TIPSAntBT and triarylamine, these materials show a threefold improvement in hole‐transporting properties and better photovoltaic performance in solution‐processed SMOSCs, with the best power conversion efficiency being 2.96 % at a high open‐circuit voltage of 0.85 V.
Inbreeding and outbreeding depression in Stylidium hispidum: implications for mixing seed sources for ecological restoration
Authors: Hufford Kristina M. , Krauss Siegfried L. , Veneklaas Erik J.
Published: August 2012

The benefits of composite rather than local seed provenances for ecological restoration have recently been argued, largely on the basis of maximizing evolutionary potential. However, these arguments have downplayed the potentially negative consequences of outbreeding depression once mixed provenances interbreed. In this study, we compared intraspecific F1 hybrid performance and molecular marker differentiation among four populations of Stylidium hispidum, a species endemic to Southwestern Australia. Multivariate ordination of 134 AFLP markers analyzed genetic structure and detected two clusters of paired sites that diverged significantly for marker variation along a latitudinal boundary. To test for outbreeding depression and to determine the consequences of molecular population divergence for hybrid fitness, we conducted controlled pollinations and studied germination and survival for three cross categories (within‐population crosses, short‐ and long‐distance F1 hybrids) for paired sites distributed within and between the two genetically differentiated regions. We found evidence of outbreeding depression in long‐distance hybrids (111–124 km), and inbreeding depression among progeny of within‐population crosses, relative to short‐distance (3–10 km) hybrids, suggesting an intermediate optimal outcrossing distance in this species. These results are discussed in light of the evolutionary consequences of mixing seed sources for biodiversity restoration.
Enhancement of plasmid DNA immunogenicity with linear polyethylenimine
Authors: Grant Evita V. , Thomas Mini , Fortune Jennifer , Klibanov Alexander M. , Letvin Norman L.
Published: August 2012

The utility of plasmid DNA as an immunogen has been limited by its weak immunogenicity. In the present study, we evaluated the ability of a family of linear polyethylenimine (PEI) polymers, complexed to plasmid DNA, to augment DNA expression in vivo and to enhance antigen‐specific adaptive immune responses. We showed that four of five structurally different PEIs that we evaluated increased in vivo DNA expression 20‐ to 400‐fold, and enhanced DNA‐induced epitope‐specific CD8+ T‐cell responses 10‐ to 25‐fold in BALB/c and C57BL/6J mice respectively, when delivered intravenously. Functional studies of the PEI‐DNA‐induced CD8+ T‐cell responses demonstrated that formulation of DNA with PEI was associated with increased numbers of cells secreting type I cytokines. In addition, PEI‐DNA complexes improved antigen‐specific TH1‐helper cell and humoral responses. Most importantly, the PEI‐DNA complexes elicited memory cellular responses, capable of rapid expansion and accelerated clearance of a lethal dose of recombinant Listeria monocytogenes. Lastly, we identified physical properties of PEI‐DNA complexes that are associated with enhanced DNA‐elicited immunogenicity. These findings demonstrate that PEI polymers can play an important role in the development of DNA‐based vaccines in the setting of infectious disease prevention and cancer therapy.
Differentiation of Oxygen Atom Chirality in Copper(II) Complexes with Dipicolylamine‐Derived Ligands
Authors: Mikata Yuji , Fujimoto Tomomi , Imai Noko , Kondo Shin‐ichi
Published: August 2012

The ether coordination of the oxygen atom to the copper(II) center supported by dipicolylamine (DPA)‐derived ligands,N‐[2‐(2‐pyridylmethyloxy)ethyl]‐N,N‐bis(2‐pyridylmethyl)amine (LPy), N‐[2‐(2‐quinolylmethyloxy)ethyl]‐N,N‐bis(2‐pyridylmethyl)amine (LQ), N‐[3‐(2‐pyridylmethyloxy)‐1‐propyl]‐N,N‐bis(2‐pyridylmethyl)amine (L′Py), N‐{2‐[1‐(2‐pyridyl)ethyloxy]ethyl}‐N,N‐bis(2‐pyridylmethyl)amine (LPy*1), N‐[2‐(2‐pyridylmethyloxy)‐1‐propyl]‐N,N‐bis(2‐pyridylmethyl)amine (LPy*2), and N‐[2‐(carboxymethyloxy)ethyl]‐N,N‐bis(2‐pyridylmethyl)amine (HLCOO), have been examined. The factors that facilitate the coordination of the ether oxygen atom of these ligands to the copper center and the control of chirality around the copper‐coordinated oxygen atom are discussed. The copper center exhibits a pentacoordinate geometry with these ligands, as evidenced by X‐ray crystallography. The steric effect of the quinoline ring in the LQ complex prevents the coordination of a perchlorate anion to the copper center, which affords the pentacoordinate divalent complex with a shorter copper–oxygen bond than that for the corresponding pyridine ligand (LPy). The six‐membered chelate in the L′Py complex also exhibits a shorter Cu–O distance. The conformation of the oxygen atom of the LPy complex is unstable because of fast lone pair inversion, but this inversion is prevented for the complexes with chiral ligands, LPy*1 and LPy*2. Upon chelation to the metal center, the HLCOO ligand forms a pentacoodinate monomer complex that further affords a 1‐D polymer structure. With respect to the oxygen chirality, the water content of the solvent governs the formation of either a homochiral polymer (R‐R‐R‐R‐ or S‐S‐S‐S‐) or an alternative chirality polymer (R‐S‐R‐S‐). In this case, the isomers with respect to the oxygen chirality were separated and characterized.
Several New Phases in RE–Mg–Ge Systems (RE = Rare Earth Metal) – Syntheses, Structures, and Chemical Bonding
Authors: Suen Nian‐Tzu , Bobev Svilen
Published: August 2012

Reported are the synthesis and structural characterization of Ce5Mg8Ge8 (its own structure type), CeMg2–xGe2+x (BaAl4‐type structure), RE4Mg7Ge6 (RE = Ce–Nd, Sm; La4Mg7Ge6‐type structure), and RE4Mg5Ge6 (RE = Ce, Pr; Tm4Zn5Ge6‐type structure). The structures of these compounds have been established by single‐crystal and powder X‐ray diffraction. These compounds are closely related to each other not only in their chemical compositions but also in their structures. A common structural feature of all are MgGe4 tetrahedra, which are connected by corner‐ and/or edge‐sharing into complex polyanionic frameworks with the rare‐earth metal atoms filling the “empty” space. The structures are compared to known types of structures, and we have investigated the chemical bonding in Ce5Mg8Ge8 with electronic structure calculations, which were carried out by the tight‐bonding linear muffin‐tin orbital (TB–LMTO) method.
Layer by Layer Electrode Surface Functionalisation Using Carbon Nanotubes, Electrochemical Grafting of Azide‐Alkyne Functions and Click Chemistry
Authors: Coates Megan , Griveau Sophie , Bedioui Fethi , Nyokong Tebello
Published: August 2012

Ferrocene was covalently bonded to a layer of adsorbed single‐walled carbon nanotubes on a glassy carbon electrode surface using electrochemical grafting and click chemistry. Grafting of the 4‐azidobenzenediazonium salt onto the surface was accomplished by electrochemical reduction. The surface‐bound azide groups, with the use of a copper(I) catalyst, were reacted with ethynylferrocene to form covalent 1,2,3‐triazole bonds by click chemistry. This layer by layer construction of the electrode surface results in stable electrodes by combining good electrical conductivity and increased surface area of the nanotubes with the versatility of the Sharpless click reaction.
A Simple Strategy to Improve the Accuracy of the Injection Step in Batch Injection Analysis Systems with Amperometric Detection
Authors: Gimenes Denise Tofanello , Pereira Polyana Fernandes , Cunha Rafael Rodrigues , Bezerra da Silva Rodrigo Amorim , Munoz Rodrigo Alejandro Abarza , Richter Eduardo Mathias
Published: August 2012

In this study, we describe for the first time the application of an internal standard method to compensate for random errors associated with the injection procedure in batch injection analysis (BIA) systems with multiple pulse amperometric detection. A sequence of potential pulses was selected in such a way that the internal standard (IS) compound was detected individually at one potential pulse and both the IS and analyte, were detected at another potential pulse. The current ratio (IIS+analyte/IIS) was used in the construction of the calibration curve and then to compensate for random errors. The use of disposable syringes or manual pipettes in BIA systems increases the robustness of the method and dispenses with skilled operators.
Improved nonaqueous capillary electrophoresis for tetracyclines at subparts per billion level
Authors: Ma Tzu‐Yi , Vickroy Thomas W. , Shien Jui‐Hung , Chou Chi‐Chung
Published: August 2012

A NACE method with laser‐induced fluorescence detection was modified for sensitive detection of 4 tetracyclines (TCs) in biological samples and feeds. The changes in injection mode, injection times, id of capillary, excitation wavelength, and the use of surfactant and sample stacking technique all contributed to improved LODs of TCs to sub‐ng/mL level. With the optimized conditions, the instrumental LODs could reach 1.33 ng/mL for chlorotetracycline (CTC) and 13.3 ng/mL for TC, oxytetracycline (OTC), and doxycycline (DC), an improvement of 10–100‐fold over past studies. A simple SPE procedure was further developed for the extraction and concentration of TCs in plasma, urine, feed, and milk. Taken together, the instrumental LOD and feasible SPE concentration factors the overall LODs for CTC could reach 65 pg/mL in feed and milk and 260 pg/mL in plasma and urine. Detection limits for TC, OTC, and DC at sub‐ng/mL level were also achieved. The modified CE‐LIF method was found to be less complicated and more sensitive than the best current methods using UV or LIF detection, and has been applied successfully to assess oral absorption of DC in swine and chickens and to confirm suspected TC‐positive bovine serum samples.