bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrodynamics, mass transfer, and photocatalytic phenol selective oxidation reaction kinetics in a fixed TiO2 microreactor
Authors: Krivec Matic , Pohar Andrej , Likozar Blaž , Dražić Goran
Published: October 2014

Photocatalytic phenol dissociation was studied in a microreactor, with a TiO2 layer immobilized on the reactor inner walls. Experiments were conducted for various residence times, initial concentrations, pH values, and UV light irradiation intensities. The intermediates and products (catechol, hydroquinone, and resorcinol) were quantitatively investigated to determine the predominant reaction pathways for the investigated anatase catalyst. A three‐dimensional mathematical model was used to simulate the heterogeneous photocatalysis reaction conditions with Langmuir–Hinshelwood mechanism, considering the adsorption/desorption thermodynamic equilibria, and for kinetic parameter estimation via regression analysis. The effectiveness factor, Thiele modulus, and the correction function were calculated to determine the pore diffusion effects. The value of pH had the dramatic effect of lowering the reaction rate due to the competitive adsorption of hydroxide ions and protons on the catalyst surface. A phenol conversion of 79.5% was achieved at the residence time of 7.22 min, but without total mineralization. © 2014 American Institute of Chemical Engineers AIChE J, 61: 572–581, 2015
Maßgeschneiderte Nanopartikel für den Wirkstofftransport in der Krebstherapie
Authors: Sun Tianmeng , Zhang Yu Shrike , Pang Bo , Hyun Dong Choon , Yang Miaoxin , Xia Younan
Published: October 2014

Das Interesse der Medizin an der Nanotechnologie hat in kurzer Zeit stark zugenommen. Die Nanotechnologie könnte Lösungen für viele Probleme bieten, die mit herkömmlichen Therapeutika einhergehen, wie etwa eine schlechte Wasserlöslichkeit (zumindest was die meisten Antitumormittel angeht), fehlende Tumorspezifität, nichtspezifische Verteilung, systemische Toxizität und ein geringer therapeutischer Index. In den letzten Jahrzehnten wurden beachtliche Fortschritte bei der Entwicklung und Anwendung von technischen Nanopartikeln gemacht, um Krebs wirksamer zu behandeln. Zum Beispiel gelang der Einbau von Therapeutika in Nanopartikel, die hinsichtlich Größe, Form und Oberflächeneigenschaften optimiert wurden, um deren Löslichkeit zu verbessern, die Halbwertszeit im Blutkreislauf zu verlängern, ihre Bioverteilung zu verbessern und ihre Immunogenität zu verringern. Außerdem wurden auch die pathophysiologischen Bedingungen, wie etwa die bessere Permeabilität und der Retentionseffekt sowie die räumlichen Schwankungen des pH‐Werts genutzt, um einen Transport von Nanopartikeln und ihrer Beladung zu Tumoren zu fördern. Ferner wurden tumordirigierende Liganden (z. B. kleine organische Moleküle, Peptide, Antikörper und Nucleinsäuren) an die Oberfläche von Nanopartikeln addiert, um Krebszellen spezifisch durch selektive Bindung an oberflächenexprimierten Rezeptoren anzusteuern. Es wurde gezeigt, dass viele Arten von therapeutischen und/oder diagnostischen Substanzen (z. B. Kontrastmittel) mithilfe der gleichen Träger transportiert werden können, was Kombinationstherapien und ein Auslesen der Behandlungseffizienz in Echtzeit ermöglicht. Es ist davon auszugehen, dass sich passgenau hergestellte Nanopartikel als nächste Generation von Mitteln zur Krebstherapie und vielen anderen biomedizinischen Anwendungen entwickeln werden.
Disciformycine A und B: zwölfgliedrige Macrolid‐Glycosid‐Antibiotika aus dem Myxobakterium Pyxidicoccus fallax mit Aktivität gegen multiresistente Staphylokokken
Authors: Surup Frank , Viehrig Konrad , Mohr Kathrin I. , Herrmann Jennifer , Jansen Rolf , Müller Rolf
Published: October 2014

Zwei Macrolid‐Glycoside mit einer einzigartigen Grundstruktur wurden aus Kulturen des Myxobakteriums Pyxidicoccus fallax isoliert. Die chemische Struktur mit der absoluten Konfiguration wurde anhand einer Kombination von NMR‐Spektroskopie, MS, chemischem Abbau und Molecular Modeling aufgeklärt. Eine Analyse des mutmaßlichen Biosynthesegenclusters vermittelte Einblicke in die Biosynthese des Polyketids und bestätigte die Strukturanalyse. Die aktivere Komponente, Disciformycin B, wirkt sehr gut gegen methicillin‐ und vancomycinresistente Staphylococcus‐aureus‐Stämme.
Discovery of Selective Small‐Molecule Activators of a Bacterial Glycoside Hydrolase
Authors: Darby John F. , Landström Jens , Roth Christian , He Yuan , Davies Gideon J. , Hubbard Roderick E.
Published: October 2014

Fragment‐based approaches are used routinely to discover enzyme inhibitors as cellular tools and potential therapeutic agents. There have been few reports, however, of the discovery of small‐molecule enzyme activators. Herein, we describe the discovery and characterization of small‐molecule activators of a glycoside hydrolase (a bacterial O‐GlcNAc hydrolase). A ligand‐observed NMR screen of a library of commercially available fragments identified an enzyme activator which yielded an approximate 90 % increase in kcat/KM values (kcat=catalytic rate constant; KM=Michaelis constant). This compound binds to the enzyme in close proximity to the catalytic center. Evolution of the initial hits led to improved compounds that behave as nonessential activators effecting both KM and Vmax values (Vmax=maximum rate of reaction). The compounds appear to stabilize an active “closed” form of the enzyme. Such activators could offer an orthogonal alternative to enzyme inhibitors for perturbation of enzyme activity in vivo, and could also be used for glycoside hydrolase activation in many industrial processes.
Paramagnetische Effekte mittels eines markierten Reporterproteins
Authors: Camacho‐Zarco Aldo R. , Munari Francesca , Wegstroth Melanie , Liu Wei‐Min , Ubbink Marcellus , Becker Stefan , Zweckstetter Markus
Published: October 2014

Paramagnetische Effekte ermöglichen einzigartige Einblicke in die Struktur und Dynamik von Biomolekülen. Um diese nutzbar zu machen, wurde eine Methode entwickelt, in welcher ein Lanthanoid‐Tag an ein Reporterprotein angebracht wird, das anschließend an das Zielprotein bindet und dadurch paramagnetische Effekte im Zielprotein hervorruft. Dieser Ansatz bietet einen Zugang zu einer großen Zahl paramagnetischer Effekte auf der Basis unabhängiger Molekülausrichtungen in hochmolekularen Proteinen unbekannter 3D‐Struktur.
An M12(L1)12(L2)12 Cantellated Tetrahedron: A Case Study on Mixed‐Ligand Self‐Assembly
Authors: Sun Qing‐Fu , Sato Sota , Fujita Makoto
Published: October 2014

In the self‐assembly of PdII ions and two different, but similarly shaped, ligands (1 and 2), neither random mixing nor self‐sorting of the two ligands into two unmixed structures was observed. Instead a mixed, yet sorted, Pd12(1)12(2)12 cantellated tetrahedron (and its pseudoisomer) was selectively formed, thus revealing a fine example of intramolecular self‐sorting. A case study showed that a homothetic ratio of >2 is necessary to observe cantellated tetrahedra.
Engineered Nanoparticles for Drug Delivery in Cancer Therapy
Authors: Sun Tianmeng , Zhang Yu Shrike , Pang Bo , Hyun Dong Choon , Yang Miaoxin , Xia Younan
Published: October 2014

In medicine, nanotechnology has sparked a rapidly growing interest as it promises to solve a number of issues associated with conventional therapeutic agents, including their poor water solubility (at least, for most anticancer drugs), lack of targeting capability, nonspecific distribution, systemic toxicity, and low therapeutic index. Over the past several decades, remarkable progress has been made in the development and application of engineered nanoparticles to treat cancer more effectively. For example, therapeutic agents have been integrated with nanoparticles engineered with optimal sizes, shapes, and surface properties to increase their solubility, prolong their circulation half‐life, improve their biodistribution, and reduce their immunogenicity. Nanoparticles and their payloads have also been favorably delivered into tumors by taking advantage of the pathophysiological conditions, such as the enhanced permeability and retention effect, and the spatial variations in the pH value. Additionally, targeting ligands (e.g., small organic molecules, peptides, antibodies, and nucleic acids) have been added to the surface of nanoparticles to specifically target cancerous cells through selective binding to the receptors overexpressed on their surface. Furthermore, it has been demonstrated that multiple types of therapeutic drugs and/or diagnostic agents (e.g., contrast agents) could be delivered through the same carrier to enable combination therapy with a potential to overcome multidrug resistance, and real‐time readout on the treatment efficacy. It is anticipated that precisely engineered nanoparticles will emerge as the next‐generation platform for cancer therapy and many other biomedical applications.
Coexistence of 3d‐Ferromagnetism and Superconductivity in [(Li1−xFex)OH](Fe1−yLiy)Se
Authors: Pachmayr Ursula , Nitsche Fabian , Luetkens Hubertus , Kamusella Sirko , Brückner Felix , Sarkar Rajib , Klauss Hans‐Henning , Johrendt Dirk
Published: October 2014

Superconducting [(Li1−xFex)OH](Fe1−yLiy)Se (x≈0.2, y≈0.08) was synthesized by hydrothermal methods and characterized by single‐crystal and powder X‐ray diffraction. The structure contains alternating layers of anti‐PbO type (Fe1−yLiy)Se and (Li1−xFex)OH. Electrical resistivity and magnetic susceptibility measurements reveal superconductivity at 43 K. An anomaly in the diamagnetic shielding indicates ferromagnetic ordering near 10 K while superconductivity is retained. The ferromagnetism is from the iron atoms in the (Li1−xFex)OH layer. Isothermal magnetization measurements confirm the superposition of ferromagnetic and superconducting hysteresis. The internal ferromagnetic field is larger than the lower, but smaller than the upper critical field of the superconductor. The formation of a spontaneous vortex phase where both orders coexist is supported by 57Fe‐Mössbauer spectra, 7Li‐NMR spectra, and μSR experiments.
Sunlight‐Driven Hydrogen Peroxide Production from Water and Molecular Oxygen by Metal‐Free Photocatalysts
Authors: Shiraishi Yasuhiro , Kanazawa Shunsuke , Kofuji Yusuke , Sakamoto Hirokatsu , Ichikawa Satoshi , Tanaka Shunsuke , Hirai Takayuki
Published: October 2014

Design of green, safe, and sustainable process for the synthesis of hydrogen peroxide (H2O2) is a very important subject. Early reported processes, however, require hydrogen (H2) and palladium‐based catalysts. Herein we propose a photocatalytic process for H2O2 synthesis driven by metal‐free catalysts with earth‐abundant water and molecular oxygen (O2) as resources under sunlight irradiation (λ>400 nm). We use graphitic carbon nitride (g‐C3N4) containing electron‐deficient aromatic diimide units as catalysts. Incorporating the diimide units positively shifts the valence‐band potential of the catalysts, while maintaining sufficient conduction‐band potential for O2 reduction. Visible light irradiation of the catalysts in pure water with O2 successfully produces H2O2 by oxidation of water by the photoformed valence‐band holes and selective two‐electron reduction of O2 by the conduction band electrons.
Bis(nitroamino‐1,2,4‐triazolates): N‐Bridging Strategy Toward Insensitive Energetic Materials
Authors: Yin Ping , Parrish Damon A. , Shreeve Jean'ne M.
Published: October 2014

Modern energetic motifs for military and civilian applications are most often evaluated using various criteria, for example, energetic properties, production costs, and safety issues. Given this background, the design of energetic materials requires a deep understanding of both detonation performance and molecular stability. Here a new family of energetic bis(nitroamino‐1,2,4‐triazolates), which exhibit good thermal stabilities, excellent detonation properties, and low sensitivities, has been designed. Furthermore, two hydroxylammonium bis(azolates) with pyrazole and tetrazole backbones were synthesized, and they exhibit energetic properties analogous to the triazoles. This work highlights the application potential of N‐bridged bis(azolates) as promising energetic materials.
Application of a C6‐OH of chitosan immobilized cyclodextrin derivates on an electrochemical H2O2 biosensor
Authors: Yu Chen , Weiping Li , Yanchun Ye , JianQiang Geng , Yanwen Guo , Tianwei Wang , Liye Wang , Huimin Tan
Published: October 2014

Biosensor detecting techniques have attracted much attention in the content determination of H2O2, which has been used illegally as a food additive. An electrochemical biosensing membrane for the detection of H2O2 was developed with C6‐OH of chitosan immobilized cyclodextrin derivates (6‐CD–CTS), which possessed a high cyclodextrin loading capacity (2.12 × 10−4 mol/g), as the carrier. The biosensor was prepared through the inclusion of ferrocene as the electron mediator in a hydrophobic cavity of cyclodextrin and crosslinking catalase (CAT) to 2‐NH2 of 6‐CD–CTS. The ferrocene‐included complex was evaluated by ultraviolet–visible spectrophotometry and thermogravimetric analysis. Its electrochemical behavior was also studied. The impact of the reaction conditions on the CAT immobilization capacity was evaluated. When previous membrane was used to detect the concentration of H2O2 (CH2O2), we found that the catalysis of CAT and the signal amplification of ferrocene had a major impact on the cyclic voltammograms. The optimal working pH of the modified electrode was 7.0. The peak current (I) had a linear relationship with the H2O2 concentration (CH2O2) in the range 1.0 × 10−4 to 1.0 × 10−3 mol/L. The linear regression equation was I = 0.00475CH2O2 − 0.03025. The detection limit was 10−6 mol/L. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41499.
Development and characterization of gelatin‐based hydrogels, emulsion hydrogels, and bigels: A comparative study
Authors: Satapathy Sitipragyan , Singh Vinay K. , Sagiri Sai Sateesh , Agarwal Tarun , Banerjee Indranil , Bhattacharya Mrinal K. , Kumar Naresh , Pal Kunal
Published: October 2014

This study was designed to examine the physicochemical and electrical properties of gelatin‐based hydrogels, emulgels, and bigels. The chemical studies suggested an increase in hydrogen bonding in the emulgel and bigel when sesame oil (SO; representative vegetable oil) and SO organogel (OG; representative OG) were incorporated within the gelatin matrix. The emulgel and bigel showed better mechanical properties and higher electrical impedances compared to the hydrogel. The hydrogel showed similar swelling at pH 1.2 and 7.2. The swelling of the emulgel and bigel was higher at pH 7.2. The formulations were found to be highly hemocompatible; this indicated their biocompatible nature. Ciprofloxacin, a model antimicrobial drug, was incorporated within the formulations. The release of the drug was found to be diffusion‐mediated. The antimicrobial efficiency of all of the drug‐loaded formulations was found to be equivalent. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41502.
Supramolecular thermoplastic elastomer with thermally scratch repairable effect from 3‐amino‐1,2,4‐triazole crosslinked maleated polyethylene‐octene elastomer/nylon 12 blends
Authors: Kashif Muhammad , Chang Young‐Wook
Published: October 2014

In this study, nylon 12 (5–25 wt %) was melt blended with a supramolecular thermally repairable thermoplastic elastomer (ATA‐POE), which was generated by crosslinking of maleated polyethylene‐octene elastomer (mPOE) with 3‐amino‐1,2,4‐triazole (ATA), in an internal mixer. The effect of nylon 12 content on the phase morphology, thermomechanical properties, and thermally triggered scratch repairing effects of the ATA‐POE/nylon 12 blends was investigated. Scanning electron microscopy results showed that nylon 12 formed a dispersed phase with submicron scale in a continuous ATA‐POE phase. Fourier transform infrared spectroscopy and differential scanning calorimetry analysis revealed that there are extensive hydrogen bonding interactions between the ATA‐POE and nylon 12 in the blends, which was manifested by a decrease in the melting temperature of each polymer component. Tensile and dynamic mechanical test showed that tensile modulus increased with increasing nylon 12 contents in the blend with maintaining fairly high elastic recoverability. Furthermore, the blends containing up to 20 wt % of nylon 12 showed good scratch repairing effects when they are heated above melting temperature of the ATA‐POE phase in the blend. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41511.
On the Importance of Thermal Effects and Crystalline Disorder in the Magnetism of Benzotriazinyl‐Derived Organic Radicals
Authors: Fumanal Maria , Vela Sergi , Ribas‐Ariño Jordi , Novoa Juan J.
Published: October 2014

Recent experiments suggest that benzotriazinyl‐derived radicals are promising building blocks for the design of new functional materials. Herein, a detailed computational study of the main structural and magnetic features of two prototypes of this family of radicals is presented. By means of several computational techniques within the DFT framework, this work unveils the key importance of the thermal contraction of the crystal to quantitatively predict the magnetism of the studied compounds. In this sense, for the first time in the context of molecular magnetism, we propose to use variable‐cell geometry optimizations as an efficient alternative to obtain an estimation of low‐temperature crystal structures. The crucial role of crystalline disorder in defining the structure present at low temperature, and thus, the magnetic response, is revealed. Altogether, these are important elements for the rational design of future materials of this family of compounds.
Non‐proportional odds multivariate logistic regression of ordinal family data
Authors: Zaloumis  Sophie G. , Scurrah Katrina J. , Harrap Stephen B. , Ellis Justine A. , Gurrin Lyle C.
Published: October 2014

Methods to examine whether genetic and/or environmental sources can account for the residual variation in ordinal family data usually assume proportional odds. However, standard software to fit the non‐proportional odds model to ordinal family data is limited because the correlation structure of family data is more complex than for other types of clustered data. To perform these analyses we propose the non‐proportional odds multivariate logistic regression model and take a simulation‐based approach to model fitting using Markov chain Monte Carlo methods, such as partially collapsed Gibbs sampling and the Metropolis algorithm. We applied the proposed methodology to male pattern baldness data from the Victorian Family Heart Study.
Apoptosis, necrosis, and autophagy in mouse intestinal damage after 15‐Gy whole body irradiation
Authors: Chen Qiu , Xia Xiaochun , Wu Shu , Wu Anqing , Qi Dandan , Liu Wei , Cui Fengmei , Jiao Yang , Zhu Wei , Gu Yongping , Gao Hongjian , Zhang Xueguang , Cao Jianping
Published: October 2014

Enterocytes die during high‐dose radiation exposure in radiation accidents. The modality of cell death has a profound effect on the therapeutic response. The ilea from mice with 15 Gy total body irradiation (TBI) were drawn, morphological features observed by hematoxylin and eosin staining and transmission electron micrographs. The biochemical features of mouse ileum presented with the structure were cleaved Caspase‐3 (apoptosis marker), Light Chain 3 (LC3)‐I's conversion to LC3‐II (autophagy marker) and high mobility group box chromosomal protein 1's secretion (necrosis marker). Then, the autophagy inhibitor (3‐methyladenine), caspase inhibitor (Z‐VAD‐FMK) or necrosis inhibitor (necrostatin) was used to prevent death. Apoptosis, autophagy and necrosis were all appeared in the ileum, but necrosis had the biggest size; the use of 3‐methyladenine and Z‐VAD‐FMK prolong one day's life of the mice after 15 Gy TBI, necrostatin significantly extended the lifespan of 15 Gy irradiated mice (p < 0.05). The results suggest that the death of enterocytes could not be classified into one type of cell death but rather as ‘mixed death.’ Copyright © 2014 John Wiley & Sons, Ltd.
Single‐Molecule Imaging Reveals that Small Amyloid‐β1–42 Oligomers Interact with the Cellular Prion Protein (PrPC)
Authors: Ganzinger Kristina A. , Narayan Priyanka , Qamar Seema S. , Weimann Laura , Ranasinghe Rohan T. , Aguzzi Adriano , Dobson Christopher M. , McColl James , St. George‐Hyslop Peter , Klenerman David
Published: October 2014

Oligomers of the amyloid‐β peptide (Aβ) play a central role in the pathogenesis of Alzheimer’s disease and have been suggested to induce neurotoxicity by binding to a plethora of cell‐surface receptors. However, the heterogeneous mixtures of oligomers of varying sizes and conformations formed by Aβ42 have obscured the nature of the oligomeric species that bind to a given receptor. Here, we have used single‐molecule imaging to characterize Aβ42 oligomers (oAβ42) and to confirm the controversial interaction of oAβ42 with the cellular prion protein (PrPC) on live neuronal cells. Our results show that, at nanomolar concentrations, oAβ42 interacts with PrPC and that the species bound to PrPC are predominantly small oligomers (dimers and trimers). Single‐molecule biophysical studies can thus aid in deciphering the mechanisms that underlie receptor‐mediated oAβ‐induced neurotoxicity, and ultimately facilitate the discovery of novel inhibitors of these pathways.
A Zinc Phthalocyanine Based Periodic Mesoporous Organosilica Exhibiting Charge Transfer to Fullerenes
Authors: Auras Florian , Li Yan , Löbermann Florian , Döblinger Markus , Schuster Jörg , Peter Laurence M. , Trauner Dirk , Bein Thomas
Published: October 2014

Periodic mesoporous organosilica (PMO) materials offer a strategy to position molecular semiconductors within a highly defined, porous network. We developed thin films of a new semiconducting zinc phthalocyanine‐bridged PMO exhibiting a face‐centered orthorhombic pore structure with an average pore diameter of 11 nm. The exceptional degree of order achieved with this PMO enabled us to create thin films consisting of a single porous domain throughout their entire thickness, thus providing maximal accessibility for subsequent incorporation of a complementary phase. The phthalocyanine building blocks inside the pore walls were found to be well‐aggregated, enabling electronic conductivity and extending the light‐harvesting capabilities to the near IR region. Ordered 3D heterojunctions capable of promoting photo‐induced charge transfer were constructed by impregnation of the PMO with a fullerene derivative. When integrated into a photovoltaic device, the infiltrated PMO is capable of producing a high open‐circuit voltage and a considerable photocurrent, which represents a significant step towards potential applications of PMOs in optoelectronics.
Revised Role of Selectfluor in Homogeneous Au‐Catalyzed Oxidative CO Bond Formations
Authors: Geng Cuihuan , Zhu Rongxiu , Li Mingxia , Lu Tongxiang , Wheeler Steven E. , Liu Chengbu
Published: October 2014

The pairing of transition metal catalysis with the reagent Selectfluor (F‐TEDA–BF4) has attracted considerable attention due to its utility in myriad CC and Cheteroatom bond‐forming reactions. However, little mechanistic information is available for Selectfluor‐mediated transition metal‐catalyzed reactions and controversy surrounds the precise role of Selectfluor in these processes. We present herein a systematic investigation of homogeneous Au‐catalyzed oxidative CO bond‐forming reactions using density functional theory calculations. Currently, Selectfluor is thought to serve as an external oxidant in AuI/AuIII catalysis. However, our investigations suggest that these reactions follow a newly proposed mechanism in which Selectfluor functions as an electrophilic fluorinating reagent involved in a fluorination/defluorination cycle. We have also explored Selectfluor‐mediated gold‐catalyzed homocoupling reactions, which, when cyclopropyl propargylbenzoate is used as a substrate, lead to an unexpected byproduct.
A Metal–Organic Framework Containing Unusual Eight‐Connected Zr–Oxo Secondary Building Units and Orthogonal Carboxylic Acids for Ultra‐sensitive Metal Detection
Authors: Carboni Michaël , Lin Zekai , Abney Carter W. , Zhang Teng , Lin Wenbin
Published: October 2014

Two metal–organic frameworks (MOFs) with Zr–oxo secondary building units (SBUs) were prepared by using p,p′‐terphenyldicarboxylate (TPDC) bridging ligands pre‐functionalized with orthogonal succinic acid (MOF‐1) and maleic acid groups (MOF‐2). Single‐crystal X‐ray structure analysis of MOF‐1 provides the first direct evidence for eight‐connected SBUs in UiO‐type MOFs. In contrast, MOF‐2 contains twelve‐connected SBUs as seen in the traditional UiO MOF topology. These structural assignments were confirmed by extended X‐ray absorption fine structure (EXAFS) analysis. The highly porous MOF‐1 is an excellent fluorescence sensor for metal ions with the detection limit of <0.5 ppb for Mn2+and three to four orders of magnitude greater sensitivity for metal ions than previously reported luminescent MOFs.
Enantiomeric Separations of Ruthenium (II) Polypyridyl Complexes Using HPLC With Cyclofructan Chiral Stationary Phases
Authors: Shu Yang , Breitbach Zachary S. , Dissanayake Milan K. , Perera Sirantha , Aslan Joseph M. , Alatrash Nagham , MacDonnell Frederick M. , Armstrong Daniel W.
Published: October 2014

The enantiomeric separation of 21 ruthenium (II) polypyridyl complexes was achieved with a novel class of cyclofructan‐based chiral stationary phases (CSPs) in the polar organic mode. Aromatic derivatives on the chiral selectors proved to be essential for enantioselectivity. The R‐napthylethyl carbamate functionalized cyclofructan 6 (LARIHC CF6‐RN) column proved to be the most effective overall, while the dimethylphenyl carbamate cyclofructan 7 (LARIHC CF7‐DMP) showed complementary selectivity. A combination of acid and base additives was necessary for optimal separations. The retention factor vs. acetonitrile/methanol ratio plot showed a U‐shaped retention curve, indicating that different interactions take place at different polar organic solvent compositions. The separation results indicated that π–π interactions, steric effects, and hydrogen bonding contribute to the enantiomeric separation of ruthenium (II) polypyridyl complexes with cyclofructan chiral stationary phases in the polar organic mode. Chirality 27:64–70, 2015. © 2014 Wiley Periodicals, Inc.
Das Erdölzeitalter
Authors: Offermanns Heribert , Salesch Martin
Published: October 2014

Erdöl – vor 100 bis 400 Millionen Jahren aus abgestorbenen Meeresorganismen entstanden – wurde schon seit mehr als 5000 Jahren von den Hochkulturen des Vorderen Orients als Schmierstoff und Bindemittel, zu Heilzwecken, zur Einbalsamierung, Kalfaldern von Booten und zu Kriegszwecken verwendet. Die industrielle Nutzung als Lampenbrennstoff wurde durch die von einigen Pionieren gefundene Methode der Destillation möglich. Nach den ersten erfolgreichen Erdölbohrungen in Wietze (1858) und Titusville (1859) setzte ein Boom ein, der auch nicht gebrochen wurde als Edison die Glühbirne erfand, da der Benzinkarren konstruiert worden war. Die rasch einsetzende Motorisierung läutete das Erdölzeitalter ein. Erdöl gewann auch an Bedeutung als Energierohstoff und ist der wichtigste Chemierohstoff. Die Vorräte an fossilen Rohstoffen sind endlich und Erdöl wird noch im diesem Jahrhundert weitgehend erschöpft sein. Es bedarf enormer Anstrengungen, Energie‐ und Chemierohstoffe “Beyond Oil” bereitzustellen und den Forderungen nach Versorgungssicherheit, Bezahlbarkeit und Umweltschonung gerecht zu werden.
Joseph Beuys und die Braunkreuzfarbe
Authors: Valler Ole , Nast Krzysztof , Strieder Barbara , Scholz Peter
Published: October 2014

Physikalisch‐chemische Analysetechniken, allen voran die zerstörungsfreie Röntgenfluoreszenzanalytik (RFA) vor Ort im Museum, geben Einblick in Materialeinsatz und Schaffensprozesse des Künstlers Joseph Beuys. Recherchearbeit, die Befragung von Zeitzeugen und andere Herangehensweisen kennzeichnen die interdisziplinären Anforderungen und den Reiz, den moderne kunsthistorische Arbeit ausmacht; die chemische Analytik liefert einen Beitrag. Ein analytisches Instrument, mit dem die bislang wenig systematische Zuordnung in die Werkgruppe der Braunkreuz‐Arbeiten nunmehr erfolgen kann, wird vorgeschlagen: die Pigmentanalyse mittels RFA.
Dehydrierung: Die Angst geht um
Authors: Roth Klaus
Published: October 2014

Wasser ist gesund, ja lebenswichtig, aber auch giftig. In unserem Körper sorgt ein ausgeklügeltes biochemisches Regelungssystem für die tägliche Aufnahme der optimalen Wassermenge. Wir müssen nicht befürchten, unter normalen Umständen dehydratisiert zu werden, wenn wir trinken, wenn wir “durstig” sind und aufhören, wenn wir “nicht durstig” [51] sind. Nur wenn wir entgegen unserem Körpergefühl exorbitant viel Wasser trinken, begeben wir uns in Gefahr. Wohl dem, der sich einige Chemiekenntnisse gepaart mit gesundem Menschenverstand und ein wenig kritischer Distanz gegenüber dem vielstimmigen, aber unqualifiziertem Zeitgeist und Modediäten bewahrt hat.
Mehrfach ungesättigte Fettsäuren als Nervennahrung
Authors: Hille‐Rehfeld Annette
Published: October 2014

An den Synapsen von Nervenzellen muss nach der Freisetzung von Neurotransmittern aus Speichervesikeln das Gleichgewicht der Membranen durch Endocytose wiederhergestellt werden. Die Bildung der Endocytosevesikel wird durch Lipide mit mehrfach ungesättigten Fettsäuren gefördert, die Fehlstellen in der gekrümmten Lipiddoppelschicht minimieren und so die Flexibilität der Membranen erhöhen.
Chemie, die uns guttut
Authors: Harrer Roswitha
Published: October 2014

Hart, Zement, Beton: In der Antike noch sehr erfolgreich, war das “opus caementicium” über 1000 Jahre in Vergessenheit geraten. Erst im frühen 19. Jahrhundert begann man wieder mit Zement und Beton zu bauen – heute ist kein Stadtbild mehr ohne die hydratisierten Minerale vorstellbar. Aber auch in der Zahnmedizin sind mineralische Härtungsreaktionen nützlich. Die Chemie des Zements tut gut.
Analysis of heat transfer in a vessel with helical pipe coil and multistage impeller
Authors: Dostál Martin , Věříšová Marcela , Petera Karel , Jirout Tomáš , Fořt Ivan
Published: October 2014

Results of heat transfer coefficient measurements in an agitated vessel heated or cooled by the liquid media flowing in a helical pipe coil are presented in this paper. The multistage impeller made of two pitched six‐blade impellers and adjustable clearance was used in a vessel with conical bottom. The transient method based on measuring the temperature dependency on time and solving the unsteady enthalpy balance was used to determine the heat transfer coefficients between the agitated liquid and the helical pipe coil. The results are summarized by the Nusselt number correlations, which describe the dependency on the impeller Reynolds number. The second part of this paper introduces a theoretical analysis of the flow in the liquid batch near the helical pipe coil. Based on the known pumping capacity of the multistage impeller, the characteristic velocity near the helical pipe coil can be evaluated. This characteristic velocity can be then used to determine the Nusselt number describing the heat transfer in a flow around a cylinder with the same cross‐section profile as the helical pipe coil. A clear correlation between this Nusselt number and the integral Nusselt number is presented in this paper and introduces an alternative approach for prediction of heat transfer characteristics on the basis of hydrodynamic parameters describing an agitated system.
Short‐term Effects of Gray Wastewater on a Mediterranean Sandy Soil
Authors: Mekki Ali , Fki Firas , Kchaou Mariem , Sayadi Sami
Published: October 2014

The treatment of urban wastewater has been significant progress along with the development of submerged biofiltration technology. Undeniably, the combination of biological processes to physical one was a promising alternative to treat wastewater. In this study, the main objective was the application of aerobic bed reactor in urban gray wastewater treatment. Afterward, treated wastewater effects on soil properties, on seeds germination, and on plants growth were investigated. Treated wastewater showed physico‐chemical and microbiological qualities that meet the required standards for reuse in irrigation. In fact, after 130 days of treatment, the average chemical oxygen demand removal reached 84%, the average five‐day biochemical oxygen demand removal attained 91% and the effluent pH was in the right range, varying between 7.3 and 7.8. Moreover, treated water was exempt from pathogenic germs as Salmonella, Staphylococcus, and Pseudomonas. The application of such treated water for irrigation of the soil and plants has significant results. Indeed, we noticed the improvement of soil water retention capacity by an average of 12%, soil organic matter content which increased by an average of 30%, and enhancement in soil microflora count by 80%. Besides, the germination indexes of tomato (Lycopersicon esculentum) and alfalfa (Medicago sativa) were increased by 30 and 50%, respectively, in soil irrigated by untreated and treated gray wastewater. Furthermore, better growth levels for tested plant species, wheat (Triticum durum), barley (Hordeum vulgare), and sorghum (Sorghum bicolor), were obtained in the presence of treated wastewater.
Determination of Emerging Substances in the Danube and Potential Risk Evaluation
Authors: Letić Nevena N. Grujić , Milanović Maja Lj. , Milić Nataša B. , Miloradov Mirjana B.Vojinović , Radonić Jelena R. , Mihajlović Ivana J. , Sekulić Maja M. Turk
Published: October 2014

Seasonal variations of caffeine and antibiotic concentrations were investigated along the selected sites of the Danube using solid‐phase extraction followed by high‐performance liquid chromatography (HPLC). The potential risks on the aquatic organisms were evaluated. HPLC methods for caffeine and antibiotic determination were modified and validated showing good accuracy, repeatability, selectivity, and robustness. The obtained results confirmed the presence of caffeine at four sampling points, near the wastewater discharges. The mean caffeine concentrations for summer, autumn, winter, and spring were 24.78, 26.83, 24.61, and 86.29 ng/L, respectively. The analyzed antibiotics (sulfamethoxazole, chloramphenicol, and tiamuline) were under the limit of detection in all tested samples taken from the Danube. The maximum risk indexes (MaxRIs) were calculated for caffeine at each sampling site. Four out of seven selected sampling sites showed sublethal effects on the aquatic organisms with 10 < MaxRI < 100 (class II), while the other three had no potential risk for aquatic organisms. The highest potential risk was calculated for the sampling site in the vicinity of one of the biggest wastewater discharges.
P2Pedia: a peer‐to‐peer wiki for decentralized collaboration
Authors: Davoust Alan , Craig Alexander , Esfandiari Babak , Kazmierski Vincent
Published: October 2014

Existing Wiki systems such as Wikipedia depend on a centralized authority and cannot easily accommodate multiple points of view. We present P2Pedia, a social peer‐to‐peer wiki system, where users have their own local repository and can collaborate by creating, discovering, editing, and sharing pages with their peers but without synchronizing them. Multiple versions of each page can thus co‐exist on each repository and across the network, which allows for multiple points of view.

Browsing or searching the wiki thus yields multiple page versions; to help the user's page selection process, the system annotates search results with trust indicators based on the distribution of each version in the peer repositories and the topology of the social network.

We describe an experimental study where the system was deployed for academic writing exercises, and we analyze the results to validate different aspects of this collaboration principle. Copyright © 2014 John Wiley & Sons, Ltd.
Light‐Induced Self‐Assembly and Decay of J Aggregates of Thiamonomethinecyanine Dyes
Authors: Petrenko Volodymyr Yu. , Dimitriev Oleg P.
Published: October 2014

Formation of J aggregates, that is, one‐dimensional supramolecular self‐organizations in which the transition moments of individual molecules are aligned parallel to the line joining their centers through a “head‐to‐tail” arrangement, normally proceed via electrostatic interactions between oppositely charged molecular groups; this is facilitated by an electrolyte medium. Here, we show that J aggregates of thiamonomethinecyanine dyes in a solution can be assembled from dye dimers by illuminating the solution with light of the appropriate wavelength to induce excitation of the dye dimers. The reverse process is also demonstrated by application of light of the correct wavelength to induce excitation of the J aggregates. Our results indicate that spontaneous J aggregation in the dark and formation of J aggregates through illumination proceed through different mechanisms; the former resulting in an increase in the number of the aggregates and the latter in an increase in the size of the aggregates.
Improving the Field‐Effect Performance of Bi2S3 Single Nanowires by an Asymmetric Device Fabrication
Authors: Lu Fangyuan , Li Renxiong , Li Yan , Huo Nengjie , Yang Juehan , Li Yongtao , Li Bo , Yang Shengxue , Wei Zhongming , Li Jingbo
Published: October 2014

High‐quality Bi2S3 nanowires are synthesized by chemical vapor deposition and their intrinsic photoresponsive and field‐effect characteristics are explored in detail. Among the studied Au–Au, Ag–Ag, and Au–Ag electrode pairs, the device with stepwise band alignment of asymmetric Au–Ag electrodes has the highest mobility. Furthermore, it is shown that light can cause a sevenfold decrease of the on/off ratio. This can be explained by the photoexcited charge carriers that are more beneficial to the increase of Ioff than Ion. The photoresponsive properties of the asymmetric Au–Ag electrode devices were also explored, and the results show a photoconductive gain of seven with a rise time of 2.9 s and a decay time of 1.6 s.
Ordered Hierarchically Porous Carbon Codoped with Iron and Nitrogen as Electrocatalyst for the Oxygen Reduction Reaction
Authors: Deng Chengwei , Zhong Hexiang , Yao Lan , Liu Sisi , Xu Zhuang , Zhang Huamin
Published: October 2014

N‐doped carbon catalysts have attracted great attention as potential alternatives to expensive Pt‐based catalysts used in fuel cells. Herein, an ordered hierarchically porous carbon codoped with N and Fe (Fe‐NOHPC) is prepared by an evaporation‐induced self‐assembly process followed by carbonization under ammonia. The soft template and Fe species promote the formation of the porous structure and facilitate the oxygen reduction reaction (ORR).The catalyst possesses an ordered hierarchically porous structure with a large surface area (1172.5 m2 g−1) and pore volume of 1.03 cm3 g−1. Compared to commercial 20 % Pt/C, it exhibits better ORR catalytic activity and higher stability as well as higher methanol tolerance in an alkaline electrolyte, which demonstrates its potential use in fuel cells as a nonprecious cathode catalyst. The N configuration, Fe species, and pore structure of the catalysts are believed to correlate with its high catalytic activity.
Capacitance‐to‐digital: The upgrades of single chip detector
Authors: Drevinskas Tomas , Maruška Audrius , Briedis Vitalis
Published: October 2014

The capacitance‐to‐digital single chip detector was upgraded. The paper discusses hardware issues and benefits of the designed/upgraded detector. The device can be operated from rechargeable lithium‐ion battery as stand‐alone, portable system and is capable of transmitting real‐time data wirelessly. The detector and additional modules (battery, battery holder, microcontroller board, wireless module) weight is less than 85 g. Electrophoretic separation in low conductivity 20 mM MES/L‐His buffer, pH 6.1, was performed in order to evaluate detection parameters. The system is capable of quantification of potassium ions down to 0.31 μM. Investigation of differential signal acquisition configuration showed improved performance regarding external noise and temperature fluctuations. The system can be a solution for stand‐alone, field‐portable capillary format separation detector.
Liquid phase based separation systems for depletion, prefractionation, and enrichment of proteins in biological fluids and matrices for in‐depth proteomics analysis—An update covering the period 2011–2014
Authors: Puangpila Chanida , Mayadunne Erandi , El Rassi Ziad
Published: October 2014

This review article expands on the previous one (S. Selvaraju and Z. El Rassi, Electrophoresis 2012, 33, 74–88) by reviewing pertinent literature in the period extending from early 2011 to present. As the previous review article, the present one is concerned with proteomic sample preparation (e.g., depletion of high‐abundance proteins, reduction of the protein dynamic concentration range, enrichment of a particular subproteome), and the subsequent chromatographic and/or electrophoretic prefractionation prior to peptide separation and identification by LC‐MS/MS. This review article, however, is distinguished from its earlier version by expanding on capturing/enriching subphosphoproteomes by immobilized metal affinity chromatography and metal oxide affinity chromatography. Seventy‐seven papers published in the period extending from mid‐2011 to the present have been reviewed. By no means this review article is exhaustive, given the fact that its aim is to give a concise treatment of the latest developments in the field.
Comparative study of the functional properties of lupin, green pea, fava bean, hemp, and buckwheat flours as affected by pH
Authors: Raikos Vassilios , Neacsu Madalina , Russell Wendy , Duthie Garry
Published: October 2014

The demand for products of high nutritional value from sustainable sources is growing rapidly in the global food market. In this study, the effect of pH on the functional properties of lupin, green pea, fava bean, hemp, and buckwheat flours was investigated and compared with wheat flour. Functional properties included solubility, emulsifying and foaming properties, gelling ability, and water holding capacity (WHC). All flours had minimal solubility at pH 4 and their corresponding values increased with increasing pH. Emulsifying properties were improved at pH 10 for all samples and emulsion stability showed a similar trend. Increasing pH in the range 4–10 enhanced the foaming properties of the flours, particularly buckwheat and hemp. Wheat, green pea, buckwheat, and fava bean were more capable of forming firm gels compared with lupin and hemp, as indicated by least gelling concentrations (LGCs). The ranking of the water binding properties of the different types of flours were lupin>hemp>fava bean>buckwheat>green pea>wheat. Results indicate that underutilized flours from sustainable plant sources could be exploited by the food industry as functional food ingredients or as replacements of wheat flour for various food applications. Depending on the application, flour functionality may be effectively tailored by pH adjustment.
The Ghosts of Institutionalization at Pennhurst's Haunted Asylum
Authors: BEITIKS EMILY SMITH
Published: October 2014

In the woods of Spring City, Pennsylvania, lies Pennhurst, a school for people with developmental and physical disabilities from 1908 to 1987. Like many institutions, Pennhurst eventually became a place of abuse and neglect. Pennhurst was finally shut down, and the residents were relocated into group homes. Two years ago, a group well educated about Pennhurst's past formed the Pennhurst Memorial and Preservation Alliance, a nonprofit dedicated to making Pennhurst into a national museum. Standing in the way of PM&PA's vision was a businessman named Richard Chakejian, who purchased Pennhurst from the state for $2 million and has now converted it to a haunted house. The result is a bizarre hybrid of history and legend, and of criminality and commercialism, that simultaneously evokes and erases Pennhurst's troubled past.
Using Monkeys to Understand and Cure Parkinson Disease
Authors: Redmond, Jr. D. Eugene
Published: October 2014

Research with nonhuman primates is essential to medical progress and will still be necessary for the foreseeable future. Almost all research scientists agree that animal research is critical to understanding basic biology, discovering new treatments for human (and animal) diseases, and maximizing the safety of new medicines while minimizing their harm to humans. All but two of the Nobel prizes in medicine awarded over the last one hundred years have depended on animal research, and the list of modern medicines, vaccines, and other treatments, as well as basic science discoveries, is so extensive that it could not be adequately covered in even a huge volume. Increases in average life span in the last century are the result of improved public health measures, and many diseases may be related to lifestyle choices. But animal research has contributed to understanding these factors and to the development of vaccines and lifesaving treatments. The philosophical debate regarding the benefits and moral costs of animal research has also filled many volumes by ethicists and philosophers. The major arguments against the use of animals in medical research have been explicitly refuted by a few brave scientists, as well as implicitly by the vast majority of the working biomedical science community.

My contribution to this discussion is to provide a personal perspective on my decision if, when, and how to use monkeys in research experiments on Parkinson disease. As a physician researcher, I have been working for many years to understand and cure Parkinson disease.
The Utility of Basic Animal Research
Authors: Carbone Larry
Published: October 2014

For animal research that causes sentient nonhuman animal suffering to be justifiable, I believe that two conditions must be met. First, harming animals for human benefit must be morally justified; this is the speciesism justification. Second, animal research must have utility—that is, it must produce useful, empirically valid knowledge that successfully increases our understanding of human illness and treatments and that could not reasonably be obtained through other means; this is the utility justification. In other words, (some) animals must be sufficiently different from humans in morally relevant ways to allow the morality of speciesism, and (some) animals must be sufficiently similar to humans biologically for cross‐species extrapolation to have utility. Both conditions are necessary, and neither by itself is sufficient to justify animal experimentation.

I focus exclusively on the utility justification. I do not defend the morality of using animals in experiments, nor do I review the alternatives and refinements that can minimize laboratory animal suffering. I will argue that I and the medical scientists with whom I work have a sound rationale to continue the work we do.
No Animals Harmed: Toward a Paradigm Shift in Toxicity Testing
Authors: Zurlo Joanne
Published: October 2014

Advances in science have led to a new vision for toxicity testing based on human cell systems that will be more predictive, have higher throughput, cost less money, and be more comparable to real‐life exposures in humans, while using many fewer animals. This vision, embraced by leading scientific and regulatory groups, is a paradigm shift from animal‐based to human‐based testing that signals a major change in focus and promotes the development of new approaches to understanding the toxicity of chemicals in humans. Information gained from these new approaches will likely affect other areas of research as well, leading to less reliance on animals in the future.