bluuebunny/crossref_metadata_2025 huggingface dataset:
Iatrogenic aortopulmonary communications after transcatheter interventions on the right ventricular outflow tract or pulmonary artery: Pathophysiologic, diagnostic, and management considerations
Authors: Torres Alejandro , Sanders Stephen P. , Vincent Julie A. , El‐Said Howaida G. , Leahy Ryan A. , Padera Robert F. , McElhinney Doff B.
Published: February 2015

Objectives

To investigate the spectrum, etiology, and management of traumatic aortopulmonary (AP) communications after transcatheter interventions on the pulmonary circulation.

Background

An iatrogenic AP communication is an unusual complication after balloon pulmonary artery (PA) angioplasty or stenting, or transcatheter pulmonary valve replacement (TPVR). However, with the increasing application of transcatheter therapies for postoperative PA stenosis and right ventricular outflow tract (RVOT) dysfunction, including percutaneous pulmonary valve replacement, consideration of the etiology, diagnosis, and management of this problem is important for interventional cardiologists performing such procedures.

Methods and Results

We present three new cases, as well as gross anatomy and histopathology data, related to AP communications after PA interventions. We also review the literature relevant to this topic. Including these new cases, there have been 18 reported cases of iatrogenic AP communication after transcatheter interventions on the PAs or RVOT, primarily patients with transposition of the great arteries who underwent PA angioplasty after an arterial switch operation, or after TPVR in patients who had undergone a Ross procedure. The likely cause of such defects is PA trauma plus distortion of the neo‐aortic anastomosis resulting from angioplasty or stenting of the RVOT or central PAs, with subsequent dissection through the extravascular connective tissue and into the closely adjacent vessel through the devitalized tissue at the anastomosis.

Conclusions

Cardiologists performing PA or RVOT interventions should be aware of the possibility of a traumatic AP communication and consider this diagnosis when confronted with suggestive signs and symptoms. © 2015 Wiley Periodicals, Inc.
Second‐degree atrioventricular block type II and third‐degree atrioventricular block requiring cardiac pacing after tooth extraction
Authors: Kishimoto Naotaka , Toyonaga Tatsunori , Gotoh Motohiro , Kotani Junichiro
Published: February 2015

Key Clinical Message

Because atrioventricular block can cause cardiovascular collapse, the rapid management of this condition is necessary. An 82‐year‐old man complained of discomfort after tooth extraction, and electrocardiography showed second‐ and third‐degree atrioventricular blocks. Dentists should monitor patients who report discomfort using electrocardiography because of the possibility of life‐threatening arrhythmia.
Chiral Chlorohydrins from the Biocatalyzed Reduction of Chloroketones: Chiral Building Blocks for Antiretroviral Drugs
Authors: de Miranda Amanda S. , Simon Robert C. , Grischek Barbara , de Paula Gabriel C. , Horta Bruno A. C. , de Miranda Leandro S. M. , Kroutil Wolfgang , Kappe C. Oliver , de Souza Rodrigo O. M. A.
Published: February 2015

E. coli cells that contain overexpressed alcohol dehydrogenases (ADHs) were screened as biocatalysts for the stereoselective reduction of chloroketones 5 a–d, the corresponding halohydrins 6 a–d of which are building blocks in the synthesis of antiretroviral drugs. Among them, ADH from Sphingobium yanoikuyae was found to reduce chloroketone 5 c with a high stereoselectivity (90 % de) and conversion (85 %) to furnish threo halohydrin (R,S)‐6 c. ADH from Ralstonia sp. (RasADH) was able to reduce 5 a and 5 b with complementary diastereoselectivity to provide access to both threo and erythro halohydrins through “substrate‐based” stereocontrol. The RasADH‐catalyzed reductions were optimized to provide (R,S)‐6 a with 98 % conversion and 84 % diastereomeric excess (de) and (S,S)‐6 b with 95 % conversion and 86 % de. Molecular modeling studies showed that 5 b, which features a carboxybenzyl protecting group, is able to bind to the enzyme catalytic site in an “inverted” mode in comparison to tert‐butyloxycarbonyl‐ and methyloxycarbonyl‐protected substrates 5 a and 5 c, which sheds light on the observed switching of the stereopreference. RasADH‐catalyzed reductions were optimized to provide (R,S)‐6 a with 98 % conversion and 84 % de and (S,S)‐6 b with 95 % conversion and 86 % de.
Facile Synthesis of Zn0.5Cd0.5S Ultrathin Nanorods on Reduced Graphene Oxide for Enhanced Photocatalytic Hydrogen Evolution under Visible Light
Authors: Shen Shuling , Ma Anping , Tang Zhihong , Han Zhuo , Wang Mingjie , Wang Zhao , Zhi Linjie , Yang Junhe
Published: February 2015

The front cover artwork for Issue 4/2015 is a collaboration between the University of Shanghai for Science and Technology (P.R. China) and the National Center for Nanoscience and Technology (P.R. China). The image shows the fast collection and transportation of photogenerated electrons from Zn0.5Cd0.5S nanorods to graphene through a line‐to‐line interface under visible light irradiation. See the Full Paper itself at http://dx.doi.org/10.1002/cctc.201402872.
Dendrimer‐Encapsulated Palladium Nanoparticles for Continuous‐Flow Suzuki–Miyaura Cross‐Coupling Reactions
Authors: Ricciardi Roberto , Huskens Jurriaan , Holtkamp Michael , Karst Uwe , Verboom Willem
Published: February 2015

Generation three, four, and five (G3, G4, and G5) poly(amidoamine) dendrimers were used for the encapsulation of palladium nanoparticles (Pd NPs) and their covalent anchoring within glass microreactors. G3‐encapsulated Pd NPs showed the highest activity for a model Suzuki–Miyaura cross‐coupling (SMC) reaction of the three different encapsulated Pd NPs tested, as compared to G4 and G5. A kinetic study indicated a role of the nanoparticle as a procatalyst, from which molecular species are formed with an induction time of approximately 1 min. The dendrimer–nanoparticle catalytic platform exhibited excellent reactivity (high turnover frequencies and numbers) compared to other Pd NP flow reactors and dendrimer‐encapsulated Pd NPs at batch scale. Moreover, the Pd microreactor exhibited good stability, as witnessed by running the SMC reaction for more than 7 days with a low Pd leaching of 1.2 ppm. The covalently attached dendrimers may play a crucial role in stabilizing the Pd NPs, a critical feature in flow SMC reactions.
Controllable Electrochemical Synthesis of Silver Nanoparticles on Indium‐Tin‐Oxide‐Coated Glass
Authors: Yan Ziren , Peng Yang , Wu Ying , Di Junwei
Published: February 2015

A simple electrochemical approach, which integrates nanoseed nucleation and a square‐wave cyclic voltammetry (SWCV) growth strategy, was developed to construct silver nanoparticles (AgNPs) on indium tin oxide (ITO)‐coated glass surfaces. Ag nanoseeds were first deposited on the ITO surface by using pulse chronoamperometry and the particles were then grown during the SWCV process. Factors that have great effects on the characterization of AgNPs during the electrochemical process were systematically investigated. It is demonstrated that the growth process can be controlled separately. AgNPs and clusters were deposited and grown onto the ITO substrate. Moreover, the nanoparticles grew monotonically with increasing number of cycles, which provides a powerful tool to control the nanoparticle size by simply changing the number of SWCV cycles.
Visualization of Oxygen Partial Pressure and Numerical Simulation of a Running Polymer Electrolyte Fuel Cell with Straight Flow Channels to Elucidate Reaction Distributions
Authors: Nagase Katsuya , Motegi Haruki , Yoneda Masakazu , Nagumo Yuzo , Suga Takeo , Uchida Makoto , Inukai Junji , Nishide Hiroyuki , Watanabe Masahiro
Published: February 2015

Visualization of the oxygen partial pressure (pO(2)) was performed at the surface of a gas diffusion layer (GDL) and the upper part of the gas‐flow channel of the cathode of an operating polymer electrolyte fuel cell (PEFC) with straight flow channels by using an oxygen‐sensitive luminescent dye film. The gradient of pO(2) inside a channel was clearly observed, even on the GDL surface across the channel. A numerical simulation was performed to understand the reaction distributions inside the PEFC. By visualization and numerical simulation, the distributions of pO(2), the current density, water concentration, and temperature in the operating PEFC were obtained, and the relationships between the parameters were studied. Supersaturated water inside the cell was found both experimentally and computationally. pO(2) and the water concentration were concluded to be the two most important factors in determining the distribution of power generation.
Assistance Current Effect for Prevention of Voltage Reversal in Stacked Microbial Fuel Cell Systems
Authors: Kim Bongkyu , Lee Byung‐Geun , Kim Byung Hong , Chang In Seop
Published: February 2015

Herein, an assistance current is suggested as a new approach to prevent voltage reversal in series‐connected microbial fuel cells (MFCs). This approach can be used to revive reversed MFCs, as a supporting assistance current is applied through an assistance anode when voltage reversal occurs. However, when the assistance current is applied without control over the assistance current, voltage reversal is regenerated. Therefore, to control the assistance current, the suggested approach is complemented by the application of variable resistors between the anode and assistance electrode. As a result, the regenerated voltage reversal is restored and all voltages of MFC units in the stacked MFC remain positive. Thus, it is expected that this approach could resolve voltage reversal that occurs in series‐connected MFCs, and thus increase the applicability of MFC technology to the production of practically usable electricity, with potential for extension to large‐scale MFCs.
Direct Reduction of Alkyl Monohalides at Silver in Dimethylformamide: Effects of Position and Identity of the Halogen
Authors: Strawsine Lauren M. , Sengupta Arkajyoti , Raghavachari Krishnan , Peters Dennis G.
Published: February 2015

Electrochemical reduction of primary (1‐halodecane), secondary (2‐halohexane and cyclohexyl halide), and tertiary halides (tert‐butyl halide) at a silver cathode in dimethylformamide (DMF) containing 0.050 M tetramethylammonium perchlorate (TMAP) was investigated with the aid of cyclic voltammetry and controlled‐potential (bulk) electrolysis for iodides, bromides, and chlorides. Selected reductions were probed in dried DMF–TMAP and DMF containing tetra‐n‐hexylammonium perchlorate (THAP). Cyclic voltammograms reveal that the number of cathodic peaks and their potentials are highly dependent on the identity and position of the halogen as well as the composition of the solvent–electrolyte. Intermediates arising from bulk electrolysis of these halides at silver undergo both radical and carbanion reactions. Electrolysis products depend on the identity and position of the halogen, amount of residual water, and size of the electrolyte cation in the solvent–electrolyte. Theoretical calculations of molecular dipole moments and polarizabilities were performed and compared to experimental observations.
Combined Secondary Ion Mass Spectrometry Depth Profiling and Focused Ion Beam Analysis of Cu Films Electrodeposited under Oscillatory Conditions
Authors: Hai Nguyen T. M. , Lechner David , Stricker Florian , Furrer Julien , Broekmann Peter
Published: February 2015

The recrystallization behavior of Cu films electrodeposited under oscillatory conditions in the presence of plating additives was studied by means of secondary ion mass spectrometry (SIMS) and focused ion beam analysis. When combined with bis‐(sodium‐sulfopropyl)‐disulfide (SPS), Imep levelers (polymerizates of imidazole and epichlorohydrin) show characteristic oscillations in the galvanostatic potential/time transient measurements. These are related to the periodic degradation and restoration of the active leveler ensemble at the interface. The leveler action relies on adduct formation between the Imep and MPS (mercaptopropane sulfonic acid)‐stabilized CuI complexes that appear as intermediates of the copper deposition when SPS is present in the electrolyte. SIMS depth profiling proves that additives are incorporated into the growing film preferentially under transient conditions during the structural breakdown of the leveler ensemble and its subsequent restoration. In contrast, Cu films electrodeposited in the presence of a structurally intact Imep–CuI–MPS ensemble remain largely contamination free.
Ligand Effects and Their Impact on Electrocatalytic Processes Exemplified with the Oxygen Evolution Reaction (OER) on RuO2(110)
Authors: Exner Kai S. , Anton Josef , Jacob Timo , Over Herbert
Published: February 2015

By using the ab initio atomistic thermodynamics approach guided by a DFT‐derived volcano curve, we demonstrate that the thermodynamic part of the reaction barrier to the oxygen evolution reaction (OER) over RuO2(110) can be significantly reduced when moderately lowering the free adsorption energy of oxygen to the catalytically active Ru center (Rucus). With the selective replacement of metal sites in the second coordination shell of Rucus, the free oxygen adsorption energy is reduced by about 0.8 and 1.0 eV for Cr and Ir, respectively. The weakening of Rucus and oxygen‐on‐top (RucusOot) bonding results in a substantial decrease in the thermodynamic part of the reaction barrier (Gibbs free‐energy loss) by 180 meV for Cr and 150 meV for Ir. The presented strategy is motivated by homogeneous metal catalysis where dedicated modifications of the ligands are able to tune the catalytic performance of the active metal center.
Half‐Sandwich Ruthenium(II) Biotin Conjugates as Biological Vectors to Cancer Cells
Authors: Babak Maria V. , Plażuk Damian , Meier Samuel M. , Arabshahi Homayon John , Reynisson Jóhannes , Rychlik Błażej , Błauż Andrzej , Szulc Katarzyna , Hanif Muhammad , Strobl Sebastian , Roller Alexander , Keppler Bernhard K. , Hartinger Christian G.
Published: February 2015

Ruthenium(II)–arene complexes with biotin‐containing ligands were prepared so that a novel drug delivery system based on tumor‐specific vitamin‐receptor mediated endocytosis could be developed. The complexes were characterized by spectroscopic methods and their in vitro anticancer activity in cancer cell lines with various levels of major biotin receptor (COLO205, HCT116 and SW620 cells) was tested in comparison with the ligands. In all cases, coordination of ruthenium resulted in significantly enhanced cytotoxicity. The affinity of RuII–biotin complexes to avidin was investigated and was lower than that of unmodified biotin. Hill coefficients in the range 2.012–2.851 suggest strong positive cooperation between the complexes and avidin. To estimate the likelihood of binding to the biotin receptor/transporter, docking studies with avidin and streptavidin were conducted. These explain, to some extent, the in vitro anticancer activity results and support the conclusion that these novel half‐sandwich ruthenium(II)–biotin conjugates may act as biological vectors to cancer cells, although no clear relationship between the cellular Ru content, the cytotoxicity, and the presence of the biotin moiety was observed.
“Invisible” Conformers of an Antifungal Disulfide Protein Revealed by Constrained Cold and Heat Unfolding, CEST‐NMR Experiments, and Molecular Dynamics Calculations
Authors: Fizil Ádám , Gáspári Zoltán , Barna Terézia , Marx Florentine , Batta Gyula
Published: February 2015

Transition between conformational states in proteins is being recognized as a possible key factor of function. In support of this, hidden dynamic NMR structures were detected in several cases up to populations of a few percent. Here, we show by two‐ and three‐state analysis of thermal unfolding, that the population of hidden states may weight 20–40 % at 298 K in a disulfide‐rich protein. In addition, sensitive 15N‐CEST NMR experiments identified a low populated (0.15 %) state that was in slow exchange with the folded PAF protein. Remarkably, other techniques failed to identify the rest of the NMR “dark matter”. Comparison of the temperature dependence of chemical shifts from experiments and molecular dynamics calculations suggests that hidden conformers of PAF differ in the loop and terminal regions and are most similar in the evolutionary conserved core. Our observations point to the existence of a complex conformational landscape with multiple conformational states in dynamic equilibrium, with diverse exchange rates presumably responsible for the completely hidden nature of a considerable fraction.
Amorphous Silicon: New Insights into an Old Material
Authors: Spomer Natalie , Holl Sven , Zherlitsyna Larissa , Maysamy Fariba , Frost Andreas , Auner Norbert
Published: February 2015

Amorphous silicon is synthesized by treating the tetrahalosilanes SiX4 (X=Cl, F) with molten sodium in high boiling polar and non‐polar solvents such as diglyme or nonane to give a brown or a black solid showing different reactivities towards suitable reagents. With regards to their technical relevance, their stability towards oxygen, air, moisture, chlorine‐containing reaction partners RCl (R=H, Cl, Me) and alcohols is investigated. In particular, reactions with methanol are a versatile tool to deliver important products. Besides tetramethoxysilane formation, methanolysis of silicon releases hydrogen gas under ambient conditions and is thus suitable for a decentralized hydrogen production; competitive insertion into the MeOH versus the MeOH bond either yields H‐ and/or methyl‐substituted methoxy functional silanes. Moreover, compounds, such as MenSi(OMe)4−n (n=0–3) are simply accessible in more than 75 % yield from thermolysis of, for example, tetramethoxysilane over molten sodium. Based on our systematic investigations we identified reaction conditions to produce the methoxysilanes MenSi(OMe)4−n in excellent (n=0:100 %) to acceptable yields (n=1:51 %; n=2:27 %); the yield of HSi(OMe)3 is about 85 %. Thus, the methoxysilanes formed might possibly open the door for future routes to silicon‐based products.
Layer‐by‐Layer Assemblies of Catechol‐Functionalized TiO2 Nanoparticles and Porphyrins through Electrostatic Interactions
Authors: Burger Alexandra , Costa Rubén D. , Lobaz Volodymyr , Peukert Wolfgang , Guldi Dirk M. , Hirsch Andreas
Published: February 2015

In the current work, we present the successful functionalization and stabilization of P‐25 TiO2 nanoparticles by means of N1,N7‐bis(3‐(4‐tert‐butyl‐pyridium‐methyl)phenyl)‐4‐(3‐(3‐(4‐tert‐butyl‐pyridinium‐methyl)phenylamino)‐3‐oxopropyl)‐4‐(3,4‐dihydroxybenzamido)heptanediamide tribromide (1). The design of the latter is aimed at nanoparticle functionalization and stabilization with organic building blocks. On one hand, 1 features a catechol anchor to enable its covalent grafting onto the TiO2 surface, and on the other hand, positively charged pyridine groups at its periphery to prevent TiO2 agglomeration through electrostatic repulsion. The success of functionalization and stabilization was corroborated by thermogravimetric analysis, dynamic light‐scattering, and zeta potential measurements. As a complement to this, the formation of layer‐by‐layer assemblies, which are governed by electrostatic interactions, by alternate deposition of functionalized TiO2 nanoparticles and two negatively charged porphyrin derivatives, that is, 5,10,15,20‐(phenoxyacetic acid)‐porphyrin (2) and 5,10,15,20‐(4‐(2‐ethoxycarbonyl)‐4‐(2‐phenoxyacetamido)heptanedioic acid)‐porphyrin (3), is documented. To this end, the layer‐by‐layer deposition is monitored by UV/Vis spectroscopy, scanning electron microscopy, ellipsometry, and profilometry techniques. The resulting assemblies are utilized for the construction and testing of novel solar cells. From stable and repeatable photocurrents generated during several “on‐off” cycles of illumination, we derive monochromatic incident photo‐to‐current conversion efficiencies of around 3 %.
Nanocomposite Made of an Oligo(p‐phenylenevinylene)‐Based Trihybrid Thixotropic Metallo(organo)gel Comprising Nanoscale Metal–Organic Particles, Carbon Nanohorns, and Silver Nanoparticles
Authors: Bhattacharjee Subham , Samanta Suman K. , Moitra Parikshit , Pramoda K. , Kumar Ram , Bhattacharya Santanu , Rao C. N. R.
Published: February 2015

A silver ion (Ag+)‐triggered thixotropic metallo(organo)gel of p‐pyridyl‐appended oligo(p‐phenylenevinylene) derivatives (OPVs) is reported for the first time. Solubilization of single‐walled carbon nanohorns (SWCNHs) in solutions of the pure OPVs as well as in the metallogels mediated by π–π interactions has also been achieved. In situ fabrication of silver nanoparticles (AgNPs) in the SWCNH‐doped dihybrid gel leads to the formation of a trihybrid metallogel. The mechanical strength of the metallogels could be increased stepwise in the order: freshly prepared gel<dihybrid gel<trihybrid gel. Microscopic studies of the trihybrid gel indicate the formation of three distinct morphologies, that is, nanoscale metal–organic particles (NMOPs), flowerlike aggregates of SWCNHs and AgNPs, and also their integration with each other. Detailed studies suggest lamellar organizations of the linear metal–ligand complexes in the NMOPs, which upon association create a three‐dimensional network that eventually immobilizes the solvent molecules.
Induced Folding of Protein‐Sized Foldameric β‐Sandwich Models with Core β‐Amino Acid Residues
Authors: Olajos Gábor , Hetényi Anasztázia , Wéber Edit , Németh Lukács J. , Szakonyi Zsolt , Fülöp Ferenc , Martinek Tamás A.
Published: February 2015

The mimicry of protein‐sized β‐sheet structures with unnatural peptidic sequences (foldamers) is a considerable challenge. In this work, the de novo designed betabellin‐14 β‐sheet has been used as a template, and α→β residue mutations were carried out in the hydrophobic core (positions 12 and 19). β‐Residues with diverse structural properties were utilized: Homologous β3‐amino acids, (1R,2S)‐2‐aminocyclopentanecarboxylic acid (ACPC), (1R,2S)‐2‐aminocyclohexanecarboxylic acid (ACHC), (1R,2S)‐2‐aminocyclohex‐3‐enecarboxylic acid (ACEC), and (1S,2S,3R,5S)‐2‐amino‐6,6‐dimethylbicyclo[3.1.1]heptane‐3‐carboxylic acid (ABHC). Six α/β‐peptidic chains were constructed in both monomeric and disulfide‐linked dimeric forms. Structural studies based on circular dichroism spectroscopy, the analysis of NMR chemical shifts, and molecular dynamics simulations revealed that dimerization induced β‐sheet formation in the 64‐residue foldameric systems. Core replacement with (1R,2S)‐ACHC was found to be unique among the β‐amino acid building blocks studied because it was simultaneously able to maintain the interstrand hydrogen‐bonding network and to fit sterically into the hydrophobic interior of the β‐sandwich. The novel β‐sandwich model containing 25 % unnatural building blocks afforded protein‐like thermal denaturation behavior.
Tris‐Functionalized Hybrid Anderson Polyoxometalates: Synthesis, Characterization, Hydrolytic Stability and Inversion of Protein Surface Charge
Authors: Blazevic Amir , Al‐Sayed Emir , Roller Alexander , Giester Gerald , Rompel Annette
Published: February 2015

Single‐ and double‐sided functionalized hybrid organic–inorganic Anderson polyoxomolybdates with GaIII and FeIII positioned as central heteroatoms have been synthesized in a mild, two‐step synthesis in an aqueous medium. Compounds 1–4 were isolated as hydrated salts, [TBA]3[GaMo6O18(OH)3{(OCH2)3CCH2OH}]×12 H2O (1) (TBA=tetrabutylammonium), Na3[FeMo6O18{(OCH2)3CCH2OH}2]×11 H2O (2), [TMA]2[GaMo6O18(OH)3{(OCH2)3CNH3}]×7 H2O (3) (TMA=tetramethylammonium), and Na[TMA]2[FeMo6O18(OH)3{(OCH2)3CNH3}](OH)×6 H2O (4). All the compounds were characterized based on single‐crystal X‐ray diffraction (SXRD), FTIR, UV/Vis, thermogravimetric, ESI‐MS, NMR, and elemental analyses. Compound 1 was also crystallized with two smaller organic cations, giving [TMA]3[GaMo6O18(OH)3{(OCH2)3CCH2OH}]×n H2O (5) and [GDM]3[GaMo6O18(OH)3{(OCH2)3CCH2OH}]×n H2O (6) (GDM=guanidinium) and were characterized based on UV/Vis, NMR, FTIR, and elemental analyses. The use of these compounds as additives in macromolecular crystallography was investigated by examining their hydrolytic stability by using ESI‐MS in a pH range of 4 to 9. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) analysis showed that BSA remains intact in a solution containing up to 100 equivalents of 1 or 4 over more than four days at 20 °C. Zeta potential measurements demonstrate that 1–4 induce charge inversions on the positively charged surface of BSA (1 mg mL−1) with concentrations starting as low as 1.29 mM for compounds 1 and 2, which have the highest negative surface charge.
Towards the Discrimination of Carboxylates by Hydrogen‐Bond Donor Anion Receptors
Authors: Kadam Sandip A. , Martin Kerli , Haav Kristjan , Toom Lauri , Mayeux Charly , Pung Astrid , Gale Philip A. , Hiscock Jennifer R. , Brooks Simon J. , Kirby Isabelle L. , Busschaert Nathalie , Leito Ivo
Published: February 2015

The binding constants (log Kass) of small synthetic receptor molecules based on indolocarbazole, carbazole, indole, urea and some others, as well as their combinations were measured for small carboxylate anions of different basicity, hydrophilicity and steric demands, that is, trimethylacetate, acetate, benzoate and lactate, in 0.5 % H2O/[D6]DMSO by using the relative NMR‐based measurement method. As a result, four separate binding affinity scales (ladders) including thirty‐eight receptors were obtained with the scales anchored to indolocarbazole. The results indicate that the binding strength is largely, but not fully, determined by the strength of the primary hydrogen‐bonding interaction. The latter in turn is largely determined by the basicity of the anion. The higher is the basicity of the anion the stronger in general is the binding, leading to the approximate order of increasing binding strength, lactate<benzoate<acetate≤trimethylacetate, which holds with all investigated receptors. Nevertheless, there are a number of occasions when the binding order changes with changing of the carboxylate anion, sometimes quite substantially. Principal component analysis (PCA) reveals that this is primarily connected to preferential binding of trimethylacetate, supposedly caused by an additional hydrophobic/solvophobic interaction. These findings enable making better predictions, which receptor framework or cavity is best suited for carboxylate anions in receptor design.
A Ferrocenyl Kaleidoscope: Slow Interconversion of Six Diastereo‐atropisomers of 2,6‐Di‐tert‐butyl‐9,10‐diferrocenyltriptycene
Authors: Nikitin Kirill , Muldoon Jimmy , Müller‐Bunz Helge , McGlinchey Michael J.
Published: February 2015

The title triptycene, 6, has been isolated as the product of 9,10‐cycloaddition of benzyne to 9,10‐diferrocenyl‐2,6‐di‐tert‐butylanthracene, 5, whose X‐ray crystal structure is reported. Each ferrocenyl unit in 6 has access to the same three non‐equivalent molecular environments, and their rotations relative to the molecular paddlewheel give rise to six slowly interconverting atropisomers. Their dynamic behaviour in solution is a challenging NMR puzzle that can be successfully solved by taking advantage of the recently described very large diamagnetic anisotropy of the ferrocenyl moiety, together with the C2 symmetry of particular atropisomers. Application of one‐ and two‐dimensional NMR techniques over a range of temperatures together, with a detailed analysis of the homo‐ and heteronuclear correlations in 6, resulted in unequivocal mapping of the 99 1H and 162 13C positions in the six interconverting systems. Variable‐temperature 2D‐EXSY measurements revealed that, while the stability of the atropisomers is almost identical, they are separated by energy barriers which the ferrocenyls must overcome in the course of their interconversions. The heights of two different rotational barriers have been identified and these experimental findings are in good agreement with DFT calculations.
A Single‐Ion Magnet Based on a Heterometallic CoIII2DyIII Complex
Authors: Goura Joydeb , Brambleby Jamie , Goddard Paul , Chandrasekhar Vadapalli
Published: February 2015

We report a CoIII2DyIII complex, which shows single‐ion‐magnet behaviour. AC susceptibility data of this compound reveals the presence of slow relaxation of the magnetization in zero‐field below 15 K. The relaxation barrier is 88 K.
One‐Pot Synthesis of O‐Allylhydroxylamines through the Organocatalytic Oxidation of Tertiary Allylic Amines Followed by a [2,3]‐Meisenheimer Rearrangement
Authors: Theodorou Alexis , Limnios Dimitris , Kokotos Christoforos G.
Published: February 2015

A cheap, green, and highly efficient one‐pot method for the synthesis of O‐protected allylic alcohols is described. By utilizing 2,2,2‐trifluoroacetophenone as the organocatalyst and H2O2 as the oxidant, a variety of allylic amine N‐oxides were synthesized, which upon heating are converted to the final products through a [2,3]‐Meisenheimer rearrangement.
Generation of Pseudocontact Shifts in Proteins with Lanthanides Using Small “Clickable” Nitrilotriacetic Acid and Iminodiacetic Acid Tags
Authors: Loh Choy‐Theng , Graham Bim , Abdelkader Elwy H. , Tuck Kellie L. , Otting Gottfried
Published: February 2015

Pseudocontact shifts (PCS) induced by paramagnetic lanthanide ions provide unique long‐range structural information in nuclear magnetic resonance (NMR) spectra, but the site‐specific attachment of lanthanide tags to proteins remains a challenge. Here we incorporated p‐azido‐phenylalanine (AzF) site‐specifically into the proteins ubiquitin and GB1, and ligated the AzF residue with alkyne derivatives of small nitrilotriacetic acid and iminodiacetic acid tags using the CuI‐catalysed “click” reaction. These tags form lanthanide complexes with no or only a small net charge and produced sizeable PCSs with paramagnetic lanthanide ions in all mutants tested. The PCSs were readily fitted by single magnetic susceptibility anisotropy tensors. Protein precipitation during the click reaction was greatly alleviated by the presence of 150 mM NaCl.
Synthetic Studies on Actinorhodin and γ‐Actinorhodin: Synthesis of Deoxyactinorhodin and Deoxy‐γ‐actinorhodin/Crisamicin A Isomer
Authors: Mulay Sandip V. , Fernandes Rodney A.
Published: February 2015

A strategy based on bidirectional Dötz benzannulation and the oxa‐Pictet–Spengler reaction toward the synthesis of actinorhodin and γ‐actinorhodin has been explored. This work has resulted in the synthesis of deoxyactinorhodin and deoxy‐γ‐actinorhodin. The latter is a regioisomer of crisamicin A (which has 10,10′‐dihydroxy groups).
Iridium‐Catalyzed Intermolecular Dehydrogenative Silylation of Polycyclic Aromatic Compounds without Directing Groups
Authors: Murai Masahito , Takami Keishi , Takai Kazuhiko
Published: February 2015

This study describes the iridium‐catalyzed intermolecular dehydrogenative silylation of C(sp2)H bonds of polycyclic aromatic compounds without directing groups. The reaction produced various arylsilanes through both SiH and CH bond activation, with hydrogen as the sole byproduct. Reactivity was affected by the electronic nature of the aromatic compounds, and silylation of electron‐deficient and polycyclic aromatic compounds proceeded efficiently. Site‐selectivity was controlled predominantly by steric factors. Therefore, the current functionalization proceeded with opposite chemo‐ and site‐selectivity compared to that observed for general electrophilic functionalization of aromatic compounds.
Ultrasensitive Biosensing Platform Based on the Luminescence Quenching Ability of Plasmonic Palladium Nanoparticles
Authors: Li Hui , Sun De‐en , Liu Zhihong
Published: February 2015

An ultrasensitive biosensing platform for DNA and protein detection is constructed based on the luminescence quenching ability of plasmonic palladium nanoparticles (PdNPs). By growing the particles into large sizes (ca. 30 nm), the plasmonic light absorption of PdNPs is broadened and extended to the visible range with extinction coefficients as high as 109 L mol−1 cm−1, enabling complete quenching of fluorescent dyes that emit at diverse ranges and that are tagged to bioprobes. Meanwhile the nonspecific quenching of the dyes (not bound to probes) is negligible, leading to extremely low background signal. Utilizing the affinity of PdNPs towards bioprobes, such as single‐stranded (ss) DNA and polypeptide molecules, which is mainly assigned to the coordination interaction, nucleic acid assays with a quantification limit of 3 pM target DNA and protein assay are achieved with a simple mix‐and‐detect strategy based on the luminescence quenching‐and‐recovery protocol. This is the first demonstration of biosensing employing plasmonic absorption of nanopalladium, which offers pronounced sensing performances and can be reasonably expected for wide applications.
Einsatz eines Ultraschall‐Durchflussmessgerätes zur Regelung des Volumenstroms in der Hochgradienten‐Magnetseparation
Authors: Shaikh Yonas S. , Schussmann Stefan , Lieblang Michael , Kampeis Percy
Published: February 2015

Bei der Verwendung der Hochgradienten‐Magnetseparation (HGMS) in der Bioverfahrenstechnik werden meist Schlauchpumpen zur Förderung eingesetzt. Bei konstanter Drehzahl der Pumpe fällt allerdings der Volumenstrom durch den HGMS‐Filter mit der Zeit ab, weil mit zunehmender Filterbeladung der freie Strömungsquerschnitt immer weiter eingeengt wird. Daraus resultiert, dass die Beladung des HGMS‐Filters zeitlich nicht konstant erfolgt. In der vorliegenden Untersuchung wurde der Einsatz eines Ultraschall‐Durchflussmessgeräts für die dynamische Anpassung der Pumpendrehzahl zur Konstanthaltung des Volumenstroms während der Magnetseparation erprobt.
Oil extraction kinetics of hydrothermally pretreated canola seeds
Authors: Zárate Valeria , Perez Ethel E. , Crapiste Guillermo H. , Nolasco Susana M. , Fernández María B.
Published: February 2015

In this work the kinetics of oil extraction from spring canola seeds subjected to a hydrothermal pretreatment with direct steam (393 K, 5 min) was studied. The differences between the seed internal structure generated by the application of this pretreatment and that of the untreated sample (ground sample) were observed by scanning electron microscopy. Oil from both samples was extracted with hexane at different times and temperatures using a stirred batch system. Oil yield increased up to 46 % due to the hydrothermal treatment. A model was proposed to explain the oil extraction process from hydrothermally pretreated and untreated canola seeds, taking into account two main mechanisms: a washing process of the surface oil from the seed, and a diffusion process. Parameters of the model were fitted, and values of the oil fraction extracted during the washing step (0.27 and 0.50 for untreated and hydrothermally treated canola seeds, respectively) and the effective diffusion coefficient (3.1–9.4.10‐12 m2s−1) were obtained. The latter value showed an Arrhenius‐type temperature dependence in the untreated sample, but the diffusion coefficient did not vary with temperature when oil diffusion was analyzed using hydrothermally pretreated seeds.
Numerical Simulation of the Role of Dayside Magnetic Reconnection in Polar Cap Patch Formation
Authors: Sheng‐Gao YANG , Bei‐Chen ZHANG , Qing‐He ZHANG , Han‐Xian FANG , Jun‐Ming LIU , Xiao‐Lin ZHOU , Jian‐Bin ZHANG
Published: February 2015

As a significant polar space weather phenomenon, the polar cap patch formation is one of the important research subjects. Observations suggest that the strong convection flow due to the dayside magnetic reconnection has a “breaking off” effect on the TOI (Tongue of ionization), as a result the polar cap patch is formed. However, the auroral particles precipitation increases the F region electron density, which will block the “breaking off” effect. Based on a self‐consistent model of polar ionosphere, this paper simulated the F region plasma density evolution under the combined effect of soft precipitation and electric field. The results show that when local electric field is more than 80 mV·m−1, the “breaking off” occurs effectively. Also, we analyzed the evolution of various plasma parameters in the process of the “breaking off”, and discussed its internal physical mechanism.
The Improved Anisotropy Normalized Variance for Detecting Non‐Vertical Magnetization Anomalies
Authors: Heng‐Lei ZHANG , Marangoni Y. R. , Ren‐Guang ZUO , Xiang‐Yun HU
Published: February 2015

For the magnetic field with unknown magnetization direction, it is necessary to study the edge detection for the magnetic source of oblique magnetization directly. In this study, we propose a new edge detection called anisotropy normalized variance based on magnetic gradient tensor (ANV_MGT). First we use an anisotropy scale to improve the core function of ANV to show the effect of the anisotropy Gaussian function. Then the magnetic gradient tensor mode is used in the ANV method to process the anomalies with oblique magnetization. We construct a numerical model of complex magnetic anomalies with an oblique magnetization, which is used to test the edge detection method. The model test shows that the proposed method, ANV_MGT, can detect the edge of the magnetic source with non‐vertical magnetization direction. It also shows that the proposed method is better than application of ANV on the 3D analytic signal amplitude. In the application to real data from western China, a perfect magnetite ore location is determined by performing ANV_MGT for the non‐reduction to the pole data.
Computer‐Guided Design, Synthesis, and Biological Evaluation of Quinoxalinebisarylureas as FLT3 Inhibitors
Authors: Göring Stefan , Bensinger Dennis , Naumann Eva C. , Schmidt Boris
Published: February 2015

Activating mutations of FMS‐like tyrosine kinase 3 (FLT3) are present in ∼30 % of patients with acute myeloid leukemia (AML) and are associated with poor prognosis. Point mutations in the tyrosine kinase domain (TKD) are observed as primary mutations or are acquired as secondary mutations in FLT3 with internal tandem duplications (ITDs) after treatment with tyrosine kinase inhibitors (TKIs). Although dozens of potent inhibitors against FLT3 ITD have been reported, activating TKD point mutations, especially at residues F691 and D835, remain the leading cause for therapy resistance, highlighting the consistent need for new potent inhibitors. Herein we report the identification and characterization of novel quinoxaline‐based FLT3 inhibitors. We used the pharmacophore features of diverse known inhibitors as a starting point for a new optimization algorithm for type II TKIs, starting from an in silico library pharmacophore search and induced‐fit docking in the known FLT3 structure. This led to the design of a set of diverse quinoxalinebisarylureas, which were profiled in an FLT3 kinase activity assay. The most promising compounds were further evaluated in a zebrafish embryo phenotype assay.
When do we need to care about the caregiver? Supportive care needs, anxiety, and depression among informal caregivers of patients with cancer and cancer survivors
Authors: Sklenarova Halina , Krümpelmann Arne , Haun Markus W. , Friederich Hans‐Christoph , Huber Johannes , Thomas Michael , Winkler Eva C. , Herzog Wolfgang , Hartmann Mechthild
Published: February 2015

BACKGROUND

Cancer not only affects patients but also their caregivers. The objective of the current study was to assess the unmet needs of cancer caregivers and to identify possible predictors of their supportive care needs.

METHODS

In a cross‐sectional survey, 188 dyads of patients diagnosed with lung, urological, or gastrointestinal cancer and their primary caregivers were recruited. Caregivers were asked to complete the Supportive Care Needs Survey self‐report questionnaire (for partners and caregivers); patients completed the corresponding questionnaire. Both groups provided information regarding their distress (National Comprehensive Cancer Network Distress Thermometer), anxiety, and depression (Patient Health Questionnaire‐4). Clinical characteristics were obtained from medical records.

RESULTS

The mean age of the caregivers was 57.8 years. Approximately 72.3% were female. Patients had an average age of 62.5 years, with 33.0% being male. Caregivers were more distressed (P<.01) and exhibited higher anxiety scores (P<.01) compared with patients. Approximately 14.4% of caregivers reported no unmet need and 43.6% had at least 10 needs that were unmet. Main caregiver concerns were regarding health care service and information needs followed by emotional and psychological needs. To some degree, unmet needs in patients and caregivers' anxiety predicted unmet caregiver needs. Sociodemographic and clinical variables were not found to be significant predictors.

CONCLUSIONS

A substantial percentage of caregivers have unmet needs for support, mainly with regard to fears concerning the patient's condition, receiving disease‐related information, and emotional support for themselves. Prediction of unmet needs in caregivers from other clinical and psychological variables was rather poor. Therefore, by means of the frequency and disparity of caregivers unmet needs, they should be systematically assessed to direct specific offers. Cancer 2015;121:1513–1519. © 2015 American Cancer Society.
Improving access to novel agents for childhood leukemia
Authors: Sun Weili , Gaynon Paul S. , Sposto Richard , Wayne Alan S.
Published: February 2015

Leukemia is the most common pediatric cancer. Despite great progress in the development of curative therapy, leukemia remains a leading cause of death from disease in childhood, and survivors are at life‐long risk of complications of treatment. New agents are needed to further increase cure rates and decrease treatment‐associated toxicities. The complex biology and aggressive nature of childhood leukemia, coupled with the relatively small patient population available for study, pose specific challenges to the development of new therapies. In this review, the authors discuss strategies and initiatives designed to improve access to new agents in the treatment of pediatric leukemia. Cancer 2015;121:1927–1936. © 2015 American Cancer Society.
Disease characteristics, patterns of care, and survival in very elderly patients with diffuse large B‐cell lymphoma
Authors: Williams Jessica N. , Rai Ashish , Lipscomb Joseph , Koff Jean L. , Nastoupil Loretta J. , Flowers Christopher R.
Published: February 2015

BACKGROUND

Although the combination of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R‐CHOP) is considered standard therapy for diffuse large B‐cell lymphoma (DLBCL), patterns of use and the impact of R‐CHOP on survival in patients aged >80 years are less clear.

METHODS

The Surveillance, Epidemiology, and End Results (SEER)‐Medicare database was used to characterize presentation, treatment, and survival patterns in patients with DLBCL who were diagnosed between 2002 and 2009. Chi‐square tests compared characteristics and initial treatments among patients with DLBCL who were aged >80 years and ≤80 years. Multivariable logistic regression models examined factors associated with treatment selection in patients aged >80 years; standard and propensity score‐adjusted multivariable Cox proportional hazards models examined relationships between treatment regimen, treatment duration, and survival.

RESULTS

Among 4635 patients with DLBCL, 1156 (25%) were aged >80 years. Patients aged >80 years were less likely to receive R‐CHOP and more likely to be observed or receive the combination of rituximab, cyclophosphamide, vincristine, and prednisone (P<.0001 for both). Marital status, stage of disease, disease site, performance status, radiotherapy, and growth factor support were associated with initial R‐CHOP in patients aged >80 years. In propensity score‐matched multivariable Cox proportional hazards models examining relationships between treatment regimen and survival, R‐CHOP was the only regimen found to be associated with improved overall survival (hazard ratio, 0.45; 95% confidence interval, 0.33‐0.62) and lymphoma‐related survival (hazard ratio, 0.58; 95% confidence interval, 0.38‐0.88).

CONCLUSIONS

Although patients with DLBCL who were aged >80 years were less likely to receive R‐CHOP, this regimen conferred the longest survival and should be considered for this population. Further studies are needed to characterize the impact of treatment of DLBCL on quality of life among patients in this age group. Cancer 2015;121:1800–1808. © 2015 American Cancer Society.
Nonequilibrium Density Profiles in Lorentz Tubes with Thermostated Boundaries
Authors: Dolgopyat Dmitry , Nándori Péter
Published: February 2015

We consider a long Lorentz tube with absorbing boundaries. Particles are injected into the tube from the left end. We compute the equilibrium density profiles in two cases: the semi‐infinite tube (in which case the density is constant) and a long finite tube (in which case the density is linear). In the latter case, we also show that convergence to equilibrium is well described by the heat equation. In order to prove these results, we obtain new results for the Lorentz particle that are of independent interest. First, we show that a particle conditioned not to hit the boundary for a long time converges to the Brownian meander. Second, we prove several local limit theorems for particles having a prescribed behavior in the past. © 2016 Wiley Periodicals, Inc.
Pharmacokinetics and adhesion of a transdermal patch containing ethinyl estradiol and gestodene under conditions of heat, humidity, and exercise: A single‐center, open‐label, randomized, crossover study
Authors: Zurth Christian , Schuett Barbara , Casjens Manuela , Ludwig Matthias , Waellnitz Katrin
Published: February 2015

In this open‐label, randomized study, 36 women (18−45 years) applied an ethinyl estradiol/gestodene contraceptive patch once‐weekly for 3 weeks followed by a 1‐week, patch‐free interval, in 3 treatment periods. The primary objective was to evaluate the pharmacokinetics of ethinyl estradiol and gestodene under conditions of heat, humidity, and exercise. The secondary objective was to evaluate patch adhesion under the same conditions. Weeks 1 and 2 of each period comprised “standardized normal activity” (SNA); in week 3, SNA continued or women used a sauna, whirlpool, swimming pool, or performed an exercise combination. Thirty‐one women completed the study; 23 yielded evaluable pharmacokinetic data. Analyses were exploratory and conducted using an analysis of variance. Area under the concentration–time curve from 0 to 168 hours (AUC0−168) for gestodene and ethinyl estradiol during sauna, swimming, and whirlpool was equivalent to previous SNA recordings. For exercise combination, the gestodene AUC0−168 was 12% lower compared with SNA, albeit not considered clinically relevant. Two women lost a total of 3 patches during sporting activities; other detachments during this week were not correlated with sporting activity.

Overall, hormone delivery using the ethinyl estradiol/gestodene patch under conditions of heat, humidity, and exercise corresponded to delivery under normal conditions.
Interplay between Cation–π and Coinage‐Metal–Oxygen Interactions: An Ab Initio Study and Cambridge Structural Database Survey
Authors: Gao Meng , Li Qingzhong , Li Wenzuo , Cheng Jianbo
Published: February 2015

The interplay between cation–π and coinage‐metal–oxygen interactions are investigated in the ternary systems N⋅⋅⋅PhCCM⋅⋅⋅O (N=Li+, Na+, Mg2+; M=Ag, Au; O=water, methanol, ethanol). A synergetic effect is observed when cation–π and coinage‐metal–oxygen interactions coexist in the same complex. The cation–π interaction in most triads has a greater enhancing effect on the coinage‐metal–oxygen interaction. This effect is analyzed in terms of the binding distance, interaction energy, and electrostatic potential in the complexes. Furthermore, the formation, strength, and nature of both the cation–π and coinage‐metal–oxygen interactions can be understood in terms of electrostatic potential and energy decomposition. In addition, experimental evidence for the coexistence of both interactions is obtained from the Cambridge Structural Database (CSD).