bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of controlled thermoresponsive PET track‐etched membranes by ATRP method
Authors: Pan Kai , Ren Ruimin , Dan Yi , Cao Bing
Published: June 2011

Controlled thermoresponsive PET track‐etched membranes were synthesized by grafting N‐isopropylacrylamide (NIPAAm) onto the membrane surface via atom transfer radical polymerization (ATRP). The initial measurements were made to determine the anchoring of ATRP initiator on PET membrane surface. Thereafter, polymerization was carried out to control the mass of polymer by controlling reaction time grafted from the membrane surface and, ATR‐FTIR, grafting degree measurements, water contact angle measurements, TGA, and SEM were used to characterize changes in the chemical functionality, surface and pore morphology of membranes as a result of modification. Water flux measurements were used to evaluate the thermoresponsive capacity of grafted membranes. The results show the grafted PET track‐etched membranes exhibit rapid and reversible response of permeability to environmental temperature, and its permeability could be controlled by controlling polymerization time using ATRP method. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Preparation and characterization of wood/styrene‐acrylonitrile copolymer/MMT nanocomposite
Authors: Devi R. R. , Maji T. K.
Published: June 2011

Wood polymer nanocomposite (WPNC) was prepared by impregnating Simul (Salmalia malabarica) wood with styrene‐acrylonitrile copolymer (SAN), glycidyl methacrylate(GMA), and a reactive polymerizable surfactant modified montmorillonite (MMT). The physical and mechanical properties of WPNC were investigated by using XRD, tensile tester, SEM, and FTIR. The polymer loading, dimensional stability, water uptake, mechanical property, and thermal stability were found to improve due to inclusion of MMT. SEM micrographs showed the presence of polymer and MMT into cell wall and cell lumen. FTIR analysis confirmed the presence of MMT and SAN in WPNC. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Polyethylene‐montmorillonite nanocomposites obtained by in situ polymerization of ethylene with nickel‐diimine catalysts
Authors: Mignoni Marcelo Luis , Silva Jonathan Vaz Martins , de Souza Michèle Oberson , Mauler Raquel dos Santos , de Souza Roberto Fernando , Bernardo‐Gusmão Katia
Published: June 2011

Nanocomposites of exfoliated montmorillonite in polyethylene were obtained using a combination of 1,4‐bis(2,6‐diisopropylphenyl)‐acenaphthenediimine‐dichloro‐nickel(II), montmorillonite, and methylalumoxane (MAO) or trimethylaluminum (TMA) to polymerize ethylene. The properties of the polymers were strongly influenced by the amount of clay they contained. The addition of 2.5% commercial montmorillonite (KSF or Cloisite 15A) enhanced the storage modulus from 5 to 878 MPa. Transmission electron microscopy (TEM) analyses provided evidence of exfoliation of the montmorillonite with the formation of a polyethylene nanocomposite. The enhanced mechanical properties were explained as a consequence of the reinforcement due to the presence of nanoscale layers formed from exfoliation of the clay included in the polyethylene matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
On the Role of Flexibility in Protein–Ligand Interactions: the Example of p53 Tetramerization Domain
Authors: Gordo Susana , Martos Vera , Vilaseca Marta , Menéndez Margarita , de Mendoza Javier , Giralt Ernest
Published: June 2011

The recognition of protein surfaces by designed ligands has become an attractive approach in drug discovery. However, the variable nature and irregular behavior of protein surfaces defy this new area of research. The easy to understand “lock‐and‐key” model is far from being the ideal paradigm in biomolecular interactions and, hence, any new finding on how proteins and ligands behave in recognition events paves a step of the way. Herein, we illustrate a clear example on how an increase in flexibility of both protein and ligand can result in an increase in the stability of the macromolecular complex. The biophysical study of the interaction between a designed flexible tetraguanidinium‐calix[4]arene and the tetramerization domain of protein p53 (p53TD) and its natural mutant p53TD‐R337H shows how the floppy mutant domain interacts more tightly with the ligand than the well‐packed wild‐type protein. Moreover, the flexible calixarene ligand interacts with higher affinity to both wild‐type and mutated protein domains than a conformationally rigid calixarene analog previously reported. These findings underscore the crucial role of flexibility in molecular recognition processes, for both small ligands and large biomolecular surfaces.
Magnetic instability in a rotating layer at highly eccentric positions of the critical level
Authors: Marsenić A. , Ševčík S.
Published: June 2011

This study follows the numerical results presented in Marsenić & Ševčík (2010) that explored the influence of the critical level position on stability of a system. The model was a horizontal fluid layer between z = ±0.5d rotating with an angular velocity Ω = Ω0ž about the vertical axis z. The fluid was considered to be inviscid, finitely electrically conducting and incompressible and was permeated by a horizontal magnetic field B0 = ℬ︁0B0(z)y̌, where ℬ︁0 was the magnitude of the field and the function B0(z) = tanh [γ (z –z0)]. When γ is large, the field gradient is concentrated near z = z0, the critical level, the field being almost homogeneous elsewhere. In this way it controls the width of the magnetic shear layer associated with the current sheet. It was found that at conditions when the magnetic field gradient was large enough (γ = O (10)) and the critical level was placed close enough to the (bottom) perfectly conducting boundary (z0 < –0.388d for γ = 80), magnetically driven convection appeared localized to a close neighbourhood of the critical level – the so called critical layer. Based on the circumstances of its rise and its properties it was identified with the resistive tearing‐mode instability. This paper presents an analytical treatment of the problem assuming γ ≥ 1. The approach consists in separation of the computational domain into an outer region where the diffusionless limit (Elsasser number Λ → ∞) applies and an inner region (the critical layer) of finite conductivity. According to the tearing‐mode theory in classical systems, the solution in the inner region is sought as long‐wavelength with respect to the width of the critical layer. The obtained solution shows features similar to the one obtained numerically and confirmed relevance of the simplifying physical assumptions made in each region. The convection in the critical layer is strictly conditioned by a sharp magnetic shear. If the shear region is removed by further positioning of the critical level towards the perfectly conducting boundary, the localized convection disappears. It is in compliance with the fact that the system is stabilised by a perfectly conducting boundary with respect to the tearing mode. Stability is then checked numerically in the layer bounded by perfectly conducting boundaries where the critical point of the magnetic field lies on one of them. The existence of a magnetically driven instability is confirmed. Depending on the value γ, it may rise as a stationary convection (for γ < 1.5) or as a wave which for γ > 16 exhibits similarity properties (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling the total and polarized emission in evolving galaxies: “Spotty” magnetic structures
Authors: Arshakian T.G. , Stepanov R. , Beck R. , Krause M. , Sokoloff D.
Published: June 2011

Future radio observations with the Square Kilometre Array (SKA) and its precursors will be sensitive to trace spiral galaxies and their magnetic field configurations up to redshift z ≈ 3. We suggest an evolutionary model for the magnetic configuration in star‐forming disk galaxies and simulate the magnetic field distribution, the total and polarized synchrotron emission, and the Faraday rotation measures for disk galaxies at z ≲ 3. Since details of dynamo action in young galaxies are quite uncertain, we model the dynamo action heuristically relying only on well‐established ideas of the form and evolution of magnetic fields produced by the mean‐field dynamo in a thin disk. We assume a small‐scale seed field which is then amplified by the small‐scale turbulent dynamo up to energy equipartition with kinetic energy of turbulence. The large‐scale galactic dynamo starts from seed fields of 100 pc and an averaged regular field strength of 0.02 μG, which then evolves to a “spotty” magnetic field configuration in about 0.8 Gyr with scales of about one kpc and an averaged regular field strength of 0.6 μG. The evolution of these magnetic spots is simulated under the influence of star formation, dynamo action, stretching by differential rotation of the disk, and turbulent diffusion. The evolution of the regular magnetic field in a disk of a spiral galaxy, as well as the expected total intensity, linear polarization and Faraday rotation are simulated in the rest frame of a galaxy at 5GHz and 150 MHz and in the rest frame of the observer at 150 MHz. We present the corresponding maps for several epochs after disk formation. Dynamo theory predicts the generation of large‐scale coherent field patterns (“modes”). The timescale of this process is comparable to that of the galaxy age. Many galaxies are expected not to host fully coherent fields at the present epoch, especially those which suffered from major mergers or interactions with other galaxies. A comparison of our predictions with existing observations of spiral galaxies is given and discussed (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Conjunction fallacy: Causality vs. event probability
Authors: Thüring Manfred , Jungermann Helmut
Published: June 2011

Under certain conditions people give a conjunction of events a higher probability than one of its constituents. This finding has been called the ‘conjunction fallacy’ (Tversky and Kahneman, 1983). One such condition is when the conjunction includes a possible cause and an outcome (called ‘causal conjunctions’) because the strength of the causal link biases the probability judgment. In the present experiment we investigated whether this finding could be replicated and whether it could be reasonably attributed to causality or might be attributed alternatively to the single event probabilities, as has been suggested by Yates and Carlson (1986).

120 subjects read short texts each describing two diseases. These texts varied with respect to the probability of disease A and the probability of disease B (high or low), and the causal relation between the two diseases (yes or no). Ss judged the conjunctive probabilities that a person suffered from both diseases. Causality showed neither an effect upon the judged probability of conjunctions nor upon the frequency of conjunction fallacies. The single event probabilities, on the other hand, had significant effects: conjunction fallacies occured most often when the text included a combination of high and low event probability. Our results support the assumption that (a) causality is not sufficient to induce the conjunction fallacy, and (b) single event probabilities have a major influence on conjunctive probability judgments. The mental model approach is suggested as a theoretical framework that might allow the integrative and systematic examination of causal reasoning processes.
Graphic displays in decision making — the visual salience effect
Authors: Jarvenpaa Sirkka L.
Published: June 2011

The study investigates the visual salience of information in making differential predictions for alpha‐numeric versus graphic displays in consumer decision making. The experiment partially supports predictions that with alpha‐numeric displays, information is acquired in correspondence with the importance weights of the attributes, whereas under graphic conditions, information is acquired in correspondence with the visual salience of the attributes. The information display form appears to have some effect not only on the temporal order in which information on attributes is acquired, but also on the relative attention given to information on attributes during the early phases of decision making.
Reluctance to vaccinate: Omission bias and ambiguity
Authors: Ritov Ilana , Baron Jonathan
Published: June 2011

Subjects are reluctant to vaccinate a (hypothetical) child when the vaccination itself can cause death, even when this is much less likely than death from the disease prevented. This effect is even greater when there is a ‘risk group’ for death (with its overall probability held constant), even though the test for membership in the risk group is unavailable. This effect cannot be explained in terms of a tendency to assume that the child is in the risk group. A risk group for death from the disease has no effect on reluctance to vaccinate. The reluctance is an example of omission bias (Spranca, Minsk & Baron, in press), an overgeneralization of a distinction between commissions and omissions to a case in which it is irrelevant. Likewise, it would ordinarily be prudent to find out whether a child is in a risk group before acting, but in this case it is impossible, so knowledge of the existence of the risk group is irrelevant. The risk‐group effect is consistent with Frisch & Baron's (1988) interpretation of ambiguity.
Simulation of dissolved CO2 gradients in a scale‐down system: A metabolic and transcriptional study of recombinant Escherichia coli
Authors: Baez Antonino , Flores Noemí , Bolívar Francisco , Ramírez Octavio T.
Published: June 2011

Deficient mixing in industrial‐scale bioreactors is an important concern as it results in a heterogeneous environment that may affect microbial cell physiology. Dissolved carbon dioxide (dCO2) fluctuations, which can occur in large‐scale bioreactors, were simulated for the first time and their effects were evaluated on Escherichia coli expressing recombinant green fluorescent protein (GFP). The dCO2 gradients were simulated by continuously circulating the medium between two vessels of a scale‐down system to mimic mean circulation times (tc) of 50, 170, and 375 s. Specific growth rate (μ) decreased by 11% and acetate concentration increased by 23% at the highest tc compared to reference cultures. An increase in the time needed for attaining maximum GFP concentration was also observed. The effect of dCO2 fluctuations on the transcriptional levels of genes involved in the glutamate decarboxylase (gadA and gadC) and α‐ketoglutarate dehydrogenase (sucA and sucB) were analyzed by quantitative real time PCR. Such genes are known to be highly over‐ or underexpressed at elevated constant dCO2. Expression levels of gadA and gadC increased up to 60% and 72%, and sucA decreased 1.8‐fold in the culture performed at the highest tc. Only a minor decrease of sucB expression was observed at tc of 170 and 375 s. Although exposure to continuous high dCO2 can affect culture performance, in this work it was shown that E. coli is able to rescue its metabolism in very short times when cells are intermittently returned to low dCO2 conditions after being exposed to high dCO2.
Enhancing the growth of Physcomitrella patens by combination of monochromatic red and blue light – a kinetic study
Authors: Cerff Martin , Posten Clemens
Published: June 2011

In the current work we demonstrate the relevance of monochromatic light conditions in moss plant cell culture. Light intensity and illumination wavelength are important cultivation parameters due to their impact on growth and chlorophyll formation kinetics of the moss Physcomitrella patens. This moss was chosen as a model organism due to its capability to produce complex recombinant pharmaceutical proteins. Filamentous moss cells were cultivated in mineral medium in shaking flasks. The flasks were illuminated by light emitting diodes (LED) providing nearly monochromatic red and blue light as well as white light as a reference. A maximum growth rate of 0.78 day(1 was achieved under additional CO2 aeration and no growth inhibition was observed under high light illumination. The application of dual red and blue light is the most effective way to reach high growth and chlorophyll formation rates while minimizing energy consumption of the LEDs. These observations are discussed as effects of photo sensory pigments in the moss. The combination of monochromatic red and blue light should be considered when a large scale process is set up.
A minimal set of bacterial cellulases for consolidated bioprocessing of lignocellulose
Authors: Liao Hehuan , Zhang Xiao‐Zhou , Rollin Joseph A. , Zhang Yi‐Heng Percival
Published: June 2011

Cost‐effective release of fermentable sugars from non‐food biomass through biomass pretreatment/enzymatic hydrolysis is still the largest obstacle to second‐generation biorefineries. Therefore, the hydrolysis performance of 21 bacterial cellulase mixtures containing the glycoside hydrolase family 5 Bacillus subtilis endoglucanase (BsCel5), family 9 Clostridium phytofermentans processive endoglucanase (CpCel9), and family 48 C. phytofermentans cellobiohydrolase (CpCel48) was studied on partially ordered low‐accessibility microcrystalline cellulose (Avicel) and disordered high‐accessibility regenerated amorphous cellulose (RAC). Faster hydrolysis rates and higher digestibilities were obtained on RAC than on Avicel. The optimal ratios for maximum cellulose digestibility were dynamic for Avicel but nearly fixed for RAC. Processive endoglucanase CpCel9 was the most important for high cellulose digestibility regardless of substrate type. This study provides important information for the construction of a minimal set of bacterial cellulases for the consolidated bioprocessing bacteria, such as Bacillus subtilis, for converting lignocellulose to biocommodities in a single step.
Hightech aus der grünen Apotheke. Biopharmazeutika aus Pflanzen
Authors: Warzecha Heribert
Published: June 2011

Pflanzen produzieren zahlreiche Stoffe, die traditionell als Arzneimittel verwendet wurden, aber auch in der modernen Medizin noch Anwendung finden. Viele neuartige Arzneistoffe allerdings sind Biopharmazeutika wie Antikörper, Hormone und Impfstoffe. Diese werden nicht mehr aus natürlichen Quellen isoliert oder synthetisiert, sondern in transgenen Organismen (Hefen, Bakterien und Säugerzellkulturen) produziert. Auch Pflanzen haben das Potenzial, als Produktionsorganismen für beispielsweise monoklonale Antikörper, Hormone wie Insulin oder bestimmte Impf‐Antigene Anwendung zu finden. Viele Studien haben gezeigt, dass Pflanzen oder pflanzliche Zellkulturen für die Produktion im Großmaßstab geeignet sind und dass in manchen Fällen die Produkte sogar klare Vorteile gegenüber anderen Produktionssystemen haben. Das betrifft sowohl die Herstellungskosten als auch die Funktionalität der therapeutischen Proteine und deren posttranslationale Modifikation. Neue Arzneipflanzen sind also möglich und werden in Zukunft hoffentlich unseren Arzneischatz bereichern.
Das Membranpotenzial. Biophysik im Experiment
Authors: Obermeyer Gerhard , Bertl Adam
Published: June 2011

Jede Zelle ist von einer Zellmembran umgeben, die das Zellinnere von der Umwelt abgrenzt und den Aufbau einer elektrischen Potentialdifferenz (Membranspannung oder Membranpotenzial) ermöglicht. Anhand von Modellmembranen (Ionenaustauschermembran) können einfache Versuche zum Verständnis des Membranpotenzials durchgeführt werden und die Ergebnisse mit den theoretischen Beschreibungen durch die Nernst‐Gleichung beziehungsweise durch die Goldman‐Hodgkin‐Huxley‐Gleichung verglichen werden.
Der Chromatin‐Code
Authors: Kronberg Inge
Published: June 2011

Typisch für eukaryotische Zellen ist ein Zellkern mit Chromatin. Das Grundgerüst von Chromatin besteht aus Nukleosomen – eng von DNA umwickelten Histonoktameren, die Kopplungsstellen für verschiedene strukturelle und regulatorische Proteine freigeben. Schon Emil Heitz (1928) unterschied das aufgelockerte, genetisch aktive Euchromatin vom stärker kondensierten, weitgehend stillen Heterochromatin. Neue Methoden verfeinern diese Unterteilung in fünf verschiedene Chromatintypen und geben einen Einblick, wie auf diese Weise ganze Chromatinbereiche in ihrer Aktivität reguliert werden.
Mehltau‐Pilze imitieren Pollenschläuche
Authors: Brennicke Axel
Published: June 2011

Bei den blühenden Pflanzen gehören zum Sex Spermienzellen aus dem Pollen und eine Eizelle im Inneren des Stempels. Wenn ein Pollenkorn oben auf der Narbe des Stempels landet, keimt ein Zellfaden aus, der Pollenschlauch. Dieser wird durch molekulare Signale in die Nähe der Eizelle geleitet, platzt dort auf und entlässt eine Spermienzelle für die Eizelle. Pilzfäden des Mehltaus nutzen diese Moleküle für ihr Wachstum. Diese neuen Regulatoren können vielleicht für eine gezielte Resistenz gegen den Mehltau genutzt werden.
Sterilisation von Materialien und Flüssigkeiten im Autoklav
Authors: Schrödel Andrea
Published: June 2011

Während hitzestabile Materialien aus Glas, Keramik und Metall durch Erhitzen für 30 min auf 180°C bei trockener Luft im Ofen sterilisiert werden können, ist für die Sterilisation von Flüssigkeiten, Textilien und Kunststoffen eine Behandlung mit feuchter Hitze im Autoklav oft die Methode der Wahl: Heißer Wasserdampf ist bei gleicher Temperatur wesentlich wirksamer als trockene Wärme. Während man sich am heißen Wasserdampf beim Anheben eines Kochtopfdeckels verbrüht, kann man in den Luftstrom eines auf 250°C erhitzten Umluftherdes fassen, ohne große Schmerzen zu erleiden.
Start auf hohem Niveau: schon ursprüngliche Tiere besaßen komplexe FGF‐Rezeptoren
Authors: Hassel Monika , Rebscher Nicole
Published: June 2011

Die Morphogenese erfordert bereits in der frühen Entwicklung eines Tieres eine feine Abstimmung zwischen Zellen, damit diese korrekt wandern und sich ausdifferenzieren können. Hierzu haben Organismen Signalsysteme entwickelt, die in der Lage sind, extrazelluläre Signale aufzunehmen, in intrazelluläre umzuwandeln und schließlich Entwicklungsgene anzusteuern. Die Evolution dieser Signalsysteme verläuft parallel zu Veränderungen der Baupläne. Diese Koevolution lässt sich anhand von Rezeptormolekülen für Fibroblasten‐Wachstumsfaktoren (FGFR) nachvollziehen.
Carl Chun – Zoologe und Tiefseeforscher
Authors: Kockerbeck Christoph
Published: June 2011

Carl Chun war ein herausragender Meereszoologe, Spezialist für Rippenquallen und Tintenfische und Leiter der ersten deutschen Tiefsee‐Expedition mit dem Dampfer “Valdivia” in den Jahren 1898/1899.
Discrete-choice preference comparison between patients and doctors for the surgical management of oesophagogastric cancer
Authors: Thrumurthy S G , Morris J J A , Mughal M M , Ward J B
Published: June 2011

Background

Establishing preferences for surgery is paramount to preoperative patient counselling. This study aimed to prioritize and compare preferences of patients and doctors towards surgery for oesophagogastric cancer, to aid the counselling process.

Methods

A discrete-choice questionnaire containing hypothetical scenarios was designed to test patient preferences for six treatment attributes: mortality, morbidity, quality of life (QoL), cure rate, hospital type and surgeon's reputation. The survey was mailed to all patients who underwent oesophagogastric cancer resection from 2008 to 2009 at two teaching hospital sites. All doctors at these sites with previous experience in counselling patients for cancer surgery were also identified and presented with the survey. Results were analysed using a random-effects probit regression model. Spearman correlation was used to compare participants' implicit choices from the discrete-choice scenarios (their true preferences) with their explicit choices from the direct ranking of preferences (their perceived preferences).

Results

Eighty-one patients and 90 doctors completed the survey. Some 15 per cent of patients and 31 per cent of doctors based their choices solely on QoL. In order of importance, patients based their implicit responses on QoL (β = 1·19), cure rate (β = 0·82), morbidity (β = − 0·70), surgeon's reputation (β = 0·60), mortality (β = − 0·57) and hospital type (β = 0·26). Doctors similarly indicated QoL (β = 1·14) and hospital type (β = 0·31) as highest and lowest preferences respectively, but placed far greater emphasis on mortality (β = − 0·80) than morbidity (β = − 0·35). Implicit and explicit preferences correlated only for morbidity and surgeon's reputation in the patient cohort.

Conclusion

Clinicians may better meet patients' expectations and facilitate informed decision-making if QoL, cure rate and morbidity are emphasized foremost. A similar study employing preoperative patients is warranted for further clarification of preferences.
An in silico DNA cloning experiment for the biochemistry laboratory
Authors: Elkins Kelly M.
Published: June 2011

This laboratory exercise introduces students to concepts in recombinant DNA technology while accommodating a major semester project in protein purification, structure, and function in a biochemistry laboratory for junior‐ and senior‐level undergraduate students. It is also suitable for forensic science courses focused in DNA biology and advanced high school biology classes. Students begin by examining a plasmid map with the goal of identifying which restriction enzymes may be used to clone a piece of foreign DNA containing a gene of interest into the vector. From the National Center for Biotechnology Initiative website, students are instructed to retrieve a protein sequence and use Expasy's Reverse Translate program to reverse translate the protein to cDNA. Students then use Integrated DNA Technologies' OligoAnalyzer to predict the complementary DNA strand and obtain DNA recognition sequences for the desired restriction enzymes from New England Biolabs' website. Students add the appropriate DNA restriction sequences to the double‐stranded foreign DNA for cloning into the plasmid and infecting Escherichia coli cells. Students are introduced to computational biology tools, molecular biology terminology and the process of DNA cloning in this valuable single session, in silico experiment. This project develops students' understanding of the cloning process as a whole and contrasts with other laboratory and internship experiences in which the students may be involved in only a piece of the cloning process/techniques. Students interested in pursuing postgraduate study and research or employment in an academic biochemistry or molecular biology laboratory or industry will benefit most from this experience. BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION Vol. 39, No. 3, pp. 211–215, 2011.
Differentiating biochemistry course laboratories based on student experience
Authors: Jakubowski Henry V.
Published: June 2011

Content and emphases in undergraduate biochemistry courses can be readily tailored to accommodate the standards of the department in which they are housed, as well as the backgrounds of the students in the courses. A more challenging issue is how to construct laboratory experiences for a class with both chemistry majors, who usually have little or no experience with biochemical techniques and biology and biochemistry majors who do. This manuscript describes a strategy for differentiating biochemistry labs to meet the needs of students with differing backgrounds. BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION Vol. 39, No. 3, pp. 216–218, 2011.
The turn of the screw: An exercise in protein secondary structure
Authors: Pikaart Michael
Published: June 2011

An exercise using simple paper strips to illustrate protein helical and sheet secondary structures is presented. Drawing on the rich historical context of the use of physical models in protein biochemistry by early practitioners, in particular Linus Pauling, the purpose of this activity is to cultivate in students a hands‐on, intuitive sense of protein secondary structure and to complement the common computer‐based structural portrayals often used in teaching biochemistry. As students fold these paper strips into model secondary structures, they will better grasp how intramolecular hydrogen bonds form in the folding of a polypeptide into secondary structure, and how these hydrogen bonds direct the overall shape of helical and sheet structures, including the handedness of the α‐helix and the difference between right‐ and the left‐handed twist. BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION Vol. 39, No. 3, pp. 221–225, 2011.
Bridging the educational research‐teaching practice gap: Curriculum development, Part 2: Becoming an agent of change
Authors: Rogan John M. , Anderson Trevor R.
Published: June 2011

Many faculty members in science departments are experiencing pressure to improve their courses, particularly with respect to the ways in which students are taught and assessed. The purpose of this article is to provide some insights and practical ideas on how curriculum change can be brought about—how motivated individuals can become agents of change. Change almost always elicits opposing and supporting forces, examples of which are given. Finally, we discuss examples of strategies to deal with these forces and highlight various factors that need to be considered when implementing such strategies, including the concepts of a zone of feasible innovation, the zone of tolerance, and the development of communities of practice. Biochemistry and Molecular Biology Education Vol. 39, No. 3, pp. 233–241, 2011
Problem‐based test: The effect of fibroblast growth factor on gene expression
Authors: Szeberényi József
Published: June 2011

Terms to be familiar with before you start to solve the test: growth factors, transcription, translation, gene expression, serum starvation, Northern blotting, cDNA probe, autoradiography, constitutive gene expression, gene induction, apoptosis, ERK pathway Biochemistry and Molecular Biology Education Vol. 39, No. 3, pp. 226–227, 2011
BZK.SAU.FPGA10.1: A modular approach to FPGA‐based micro computer architecture design for educational purpose
Authors: Oztekin Halit , Temurtas Feyzullah , Gulbag Ali
Published: June 2011

This article describes a modular approach to FPGA‐based micro computer architecture design for supporting undergraduate courses in computer science and related discipline. We have adopted the modular approach to the second FPGA version of the BZK.SAU[6] named BZK.SAU.FPGA10.1. The BZK.SAU.FPGA10.1 platform has modular units that enable development of their own micro computer designs, particularly arithmetic and logic unit (ALU), memory and system bus, by integrating of simple building blocks. So the proposed modular approach will create high level interest in the faculty teaching computer organization and architecture course and produce significant contribution in the education of engineers. Also, such an approach could greatly increase the understanding of the architectural concept of the Microcomputer Architecture. All the modules in the BZK.SAU.FPGA10.1 design are entirely realized using schematic structure on Altera's Cyclone II Development board. So, students can implement on a hardware platform to test their own designs by downloading since it is an affordable cost for the institution. © 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 22:272–282, 2014; View this article online atwileyonlinelibrary.com/journal/cae; DOI10.1002/cae.20553
Boron Compounds as Stabilizers of a Complex Microstructure in a Co‐B‐based Catalyst for NaBH4 Hydrolysis
Authors: Arzac G. M. , Rojas T. C. , Fernández A.
Published: June 2011

Co⋅B‐based materials are widely used as catalysts for hydrogen generation through sodium borohydride self‐decomposition. In the mid 1990 s, the aqueous and organic chemistry involved in Co⋅B synthesis and handling was studied. Nevertheless, the exact microstructure of these catalysts has remained unsolved. Herein we present an exhaustive study which shows a new and complete microstructural view of a Co⋅B‐based material together with the chemistry of the cobalt and boron involved. By using nanoscale‐resolution microscopy and spectroscopy techniques, we have elucidated the role of boron compounds as stabilizers in a complex microstructure, which also explains its high catalytic performance and long‐term stability. The catalyst is proposed to be made up of 1–3 nm hcp Co0 nanoparticles embedded in amorphous CoxB (x=1, 2, 3), CoxOy, Co(BO2)2, and B2O3 phases alternatively or all together. All of these amorphous phases protect the nanocrystalline metallic core from growth and oxidation.
ChemInform Abstract: La4.27Mg2.89Zn30, a New Structure Type with Strong Positional Disorder.
Authors: Pavlyuk Volodymyr , Rozycka‐Sokolowska Ewa , Marciniak Bernard
Published: June 2011

The title compound is prepared from the elements (670 K, 3 d; annealing at 1070 K, 3 h) and its structure is determined by single crystal XRD.
ChemInform Abstract: Copper(II) Manganese(II) ortho‐Phosphate, Cu0.5Mn2.5(PO4)2.
Authors: Bond Andrew D. , Foghmoes Soeren P. V. , Warner Terence E.
Published: June 2011

The title compound is synthesized from a mixture of Cu2O, Mn2O3, and NH4H2PO4 (alumina boat, flowing Ar, 1223 K, 7 h).
ChemInform Abstract: Disordered La3Cu 4.88Se7.
Authors: Gulay L. D. , Daszkiewicz M. , Strok O. M. , Pietraszko A.
Published: June 2011

Single crystals of the title compound are obtained from a melt of the elements (evacuated silica tube, 1420 K, 3 h).
ChemInform Abstract: In situ X‐Ray Diffraction Study of Cesium Exchange in Synthetic Umbite.
Authors: Fewox Christopher S. , Clearfield Abraham , Celestian Aaron J.
Published: June 2011

The exchange of Cs+ into H1.22K0.84ZrSi3O9 ·2.16H2O (I) leading to H0.18K0.45Cs1.37ZrSi3 O9·0.98H2O (II) is monitored in situ by time‐resolved synchrotron powder XRD.
ChemInform Abstract: Investigation of the First‐Order Phase Transition in the Co1‐xMgxMoO4 Solid Solution and Discussion of the Associated Thermochromic Behavior.
Authors: Robertson L. C. , Gaudon M. , Jobic S. , Deniard P. , Demourgues A.
Published: June 2011

Pure β‐Co1‐xMgxMoO4 (0 ≤ x ≤ 1) solid solutions are prepared by solid state reactions of stoichiometric mixtures of MoO3, Co3O4, and MgO (alumina crucible, 700 °C, 20 h).
ChemInform Abstract: α‐SrNCN:Eu2+ — A Novel Efficient Orange‐Emitting Phosphor.
Authors: Krings Michael , Montana Giuseppe , Dronskowski Richard , Wickleder Claudia
Published: June 2011

The title phosphor is synthesized from a mixture of SrI2, EuI2, CsN3, and CsCN (Ta ampules, 1073 K, 1 d) and characterized by powder XRD and IR spectroscopy.
ChemInform Abstract: Nature of the Spin Frustration in the CuO2 Ribbon Chains of LiCuVO4: Crystal Structure Determination at 1.6 K, Magnetic Susceptibility Analysis, and Density Functional Evaluation of the Spin Exchange Constants.
Authors: Koo Hyun‐Joo , Lee Changhoon , Whangbo Myung‐Hwan , McIntyre Garry J. , Kremer Reinhard K.
Published: June 2011

LiCuVO4 crystallizes in the space group Imma and the structure at 1.6 K is very close to that determined by powder XRD at room temperature.
ChemInform Abstract: Advanced Electrodes for Solid Acid Fuel Cells by Platinum Deposition on CsH2PO4.
Authors: Papandrew Alexander B. , Chisholm Calum R. I. , Elgammal Ramez A. , Oezer Mustafa M. , Zecevic Strahinja K.
Published: June 2011

Pt nanoparticle networks of varying thickness and coverage are grown on fine powders of the solid acid CsH2PO4 by vapor deposition from Pt(acac)2 at 210 °C.
ChemInform Abstract: Three‐Step Calcination Synthesis of High‐Purity Li8ZrO6 with CO2 Absorption Properties.
Authors: Yin Xian‐Sheng , Zhang Qin‐Hui , Yu Jian‐Guo
Published: June 2011

The title compound is prepared from mixtures of Zr(NO3)4 and LiNO3 (calcination at 873 K for 2 h, 1073 K for 2 h, and 1173 K for 72 h).
ChemInform Abstract: Combined Triple and Double Bonds to Uranium: The NU=N—H Uranimine Nitride Molecule Prepared in Solid Argon.
Authors: Wang Xuefeng , Andrews Lester , Vlaisavljevich Bess , Gagliardi Laura
Published: June 2011

The linear title molecule forms by reactions of laser‐ablated U atoms with N2 and H2 mixtures upon codeposition in excess Ar at 5 K.
ChemInform Abstract: W‐Knotted Chain {[CuII(dien)]4 [WV(CN)8]}5+∞: Synthesis, Crystal Structure, Magnetism, and Theory.
Authors: Podgajny Robert , Pelka Robert , Desplanches Cedric , Ducasse Laurent , Nitek Wojciech , Korzeniak Tomasz , Stefanczyk Olaf , Rams Michal , Sieklucka Barbara , Verdaguer Michel
Published: June 2011

Crystals of (H3O){[Cu(dien)]4[W(CN)8]} [W(CN)8]2·6.5H2O (dien: diethylenetriamine) are prepared by slow diffusion of aqueous solutions of [Cu(dien)(H2O)2]Cl2 and Cs3[W(CN)8] in an H‐tube at room temperature (pH 5.5, 22% yield).
ChemInform Abstract: AgScO2 Revisited: Synthesis, Crystal Structure Refinement and Properties of the Single‐Phase 3R Polymorph.
Authors: Dietrich Volker , Jansen Martin
Published: June 2011

AgScO2 is synthesized by solid state reaction of Ag2O and Sc2O3 (autoclave, 100 MPa O2, 500 °C, 3 d) and characterized by powder XRD and impedance spectroscopy.
ChemInform Abstract: Immobilized DMAP Derivatives Rivaling Homogeneous DMAP.
Authors: D'Elia Valerio , Liu Yinghao , Zipse Hendrik
Published: June 2011

The polystyrene‐supported diaminopyridine compound (I) exhibits unprecedented catalytic activity in the acylation reaction of secondary or tertiary alcohols and in the aza‐Morita—Baylis—Hillman reaction of tosylimines (IX).
ChemInform Abstract: Enantioselective Organocatalytic α‐Fluorination of Cyclic Ketones.
Authors: Kwiatkowski Piotr , Beeson Teresa D. , Conrad Jay C. , MacMillan David W. C.
Published: June 2011

Primary amine‐functionalized cinchona alkaloid (I) in combination with trichloroacetic acid catalyzes the title reaction of carbo‐ and heterocyclic ketones.
ChemInform Abstract: Asymmetric Synthesis of All‐Carbon Quaternary Stereocenters via Desymmetrization of 2,2‐Disubstituted 1,3‐Propanediols.
Authors: Lee Ji Young , You Young Suk , Kang Sung Ho
Published: June 2011

The asymmetric monobenzoylation of symmetric diols is achieved with high enantioselectivities by use of the copper‐catalyst derived from Pybox‐ligand PBO.
ChemInform Abstract: Nucleophilic Fluoromethylation of Aldehydes with Fluorobis(phenylsulfonyl)methane: The Importance of Strong Li—O Coordination and Fluorine Substitution for C—C Bond Formation.
Authors: Shen Xiao , Zhang Laijun , Zhao Yanchuan , Zhu Lingui , Li Guangyu , Hu Jinbo
Published: June 2011

In contrast to previous results, fluorobis(phenylsulfonyl)methane (II) reacts readily with various aldehydes to give addition products in high yields.
ChemInform Abstract: Reactions of Fluoroalkyl‐Containing Lithium 1,3‐Diketonates with Diaminoarenes and 2‐Aminobenzenethiol.
Authors: Filyakova V. I. , Boltacheva N. S. , Sevenarad D. V. , Charushin V. N.
Published: June 2011

Reactions of the title lithiated diketonates with diaminobenzenes provides diazepine and/or benzimidazole derivatives depending on the diketone used and the reaction conditions applied.
ChemInform Abstract: Gold‐Catalyzed Rearrangements: Reaction Pathways Using 1‐Alkenyl‐2‐alkynylcyclopropane Substrates.
Authors: Barluenga Jose , Tudela Eva , Vicente Ruben , Ballesteros Alfredo , Tomas Miguel
Published: June 2011

A novel reactivity pattern for alkynyl, cyclopentene‐fused cyclopropanes in the presence of Au(I)‐catalysts results in a five‐to six‐membered ring expansion.
ChemInform Abstract: Concurrent Oxidations with Tandem Biocatalysts in One Pot: Green, Selective and Clean Oxidations of Methylene Groups to Ketones.
Authors: Zhang Wei , Tang Weng Lin , Wang Daniel I. C. , Li Zhi
Published: June 2011

The novel method involves a whole cell‐based monooxygenase‐mediated regioselective hydroxylation and the subsequent alcohol dehydrogenase‐catalyzed oxidation with cofactor recycling using acetone as the coupled substrate.
ChemInform Abstract: Chiral Iridium Spiro Aminophosphine Complexes: Asymmetric Hydrogenation of Simple Ketones, Structure, and Plausible Mechanism.
Authors: Xie Jian‐Bo , Xie Jian‐Hua , Liu Xiao‐Yan , Zhang Qian‐Qian , Zhou Qi‐Lin
Published: June 2011

The title iridium complexes allow the asymmetric hydrogenation of ketones with up to 97% e.e.
ChemInform Abstract: Asymmetric Direct Aldol Reaction of Cyclohexanone Catalyzed by (N′‐Benzyl‐N′‐D‐prolyl)‐trans‐4‐hydroxy‐L‐proline Hydrazide.
Authors: Cheng Chuanling , Wang Wenliang
Published: June 2011

A new proline catalyst is prepared and proved to be superior for the asymmetric aldol reaction between aromatic aldehydes and cyclohexanone.
ChemInform Abstract: Chloride Ion‐Catalyzed Generation of Difluorocarbene for Efficient Preparation of gem‐Difluorinated Cyclopropenes and Cyclopropanes.
Authors: Wang Fei , Zhang Wei , Zhu Jieming , Li Huaifeng , Huang Kuo‐Wei , Hu Jinbo
Published: June 2011

The carbene source (II) is less toxic and expensive than alternative reagents which can be employed for similar transformations.
ChemInform Abstract: Enabling the Synthesis of Perfluoroalkyl Bicyclobutanes via 1,3 γ‐Silyl Elimination.
Authors: Kelly Christopher B. , Colthart Allison M. , Constant Brad D. , Corning Sean R. , Dubois Lily N. E. , Genovese Jacqueline T. , Radziewicz Julie L. , Sletten Ellen M. , Whitaker Katherine R. , Tilley Leon J.
Published: June 2011

The method includes [2 + 2] cycloaddition, fluoroalkylation by the Prakash method, tosylation and solvolysis.
ChemInform Abstract: Hydroxyl‐Directed Cyclizations of 1,6‐Enynes.
Authors: Camelio Andrew M. , Barton Thomas , Guo Fenghai , Shaw Travis , Siegel Dionicio
Published: June 2011

Homopropargylic alcohols of type (IV) undergo cyclization to cis‐substituted cyclopentanes with high diastereoselectivity.
ChemInform Abstract: Copper‐Catalyzed Trifluoromethylation of Aryl Iodides with Potassium (Trifluoromethyl)trimethoxyborate.
Authors: Knauber Thomas , Arikan Fatih , Roeschenthaler Gerd‐Volker , Goossen Lukas J.
Published: June 2011

A wide range of aromatic and heteroaromatic iodides affords the products with mostly high yields.
ChemInform Abstract: Ruthenium‐Catalyzed Nitro and Nitrile Compounds Coupling with Alcohols: Alternative Route for N‐Substituted Amine Synthesis.
Authors: Cui Xinjiang , Zhang Yan , Shi Feng , Deng Youquan
Published: June 2011

Nitrobenzenes and benzonitriles are easily converted to secondary amines in the reaction with benzylic and aliphatic alcohols requiring different catalytic systems.
ChemInform Abstract: A New Class of Urea‐Substituted Cinchona Alkaloids Promote Highly Enantioselective Nitroaldol Reactions of Trifluoromethylketones.
Authors: Palacio Carole , Connon Stephen J.
Published: June 2011

Among various catalysts tested, CHUR is found to be the most efficient one.
ChemInform Abstract: Azodioxy‐Carbonyl Compounds by Oxidation of Cyclic Imines with m‐CPBA.
Authors: Perrone Serena , Pilati Tullio , Rosato Francesca , Salomone Antonio , Videtta Valeria , Troisi Luigino
Published: June 2011

A variety of racemic and chiral 4,5‐dihydrooxazoles and 3,4‐dihydro‐2H‐pyrrole is oxidized with MCPBA to afford dimeric trans‐azodioxy esters or diketone (VIII).
ChemInform Abstract: Efficient One‐Pot Selective Reduction of Esters in β‐Ketoesters Using LiHMDS and Lithium Aluminum Hydride.
Authors: Sivagurunathan K. , Kamil S. Raja Mohamed , Shafi S. Syed , Khan F. Liakth Ali , Ragavan R. Venkat
Published: June 2011

With exception of bulky substrate (IIIb), aromatic β‐ketoesters are selectively converted into the corresponding β‐hydroxy ketones following the sequence A) and B).
ChemInform Abstract: L‐Threonine‐Derived Novel Bifunctional Phosphine—Sulfonamide Catalyst‐Promoted Enantioselective Aza‐Morita—Baylis—Hillman Reaction.
Authors: Zhong Fangrui , Wang Youqing , Han Xiaoyu , Huang Kuo‐Wei , Lu Yixin
Published: June 2011

Optimized conditions are elaborated concerning the chiral catalyst and the substituents in both the sulfone and the ester group of the substrates.
ChemInform Abstract: Direct Hydrogenation of Nitroaromatics and One‐Pot Amidation with Carboxylic Acids over Platinum Nanowires.
Authors: Li Min , Hu Lei , Cao Xueqin , Hong Haiyan , Lu Jianmei , Gu Hongwei
Published: June 2011

A variety of nitroarenes is easily converted to the corresponding anilines.
ChemInform Abstract: Modifiable Sulfur Tethers as Directing Groups for Aromatic C—H Acetoxylation Reactions.
Authors: Richter Heinrich , Beckendorf Stephan , Mancheno Olga Garcia
Published: June 2011

A new class of modifiable sulfur tethers is developed for aromatic C—H functionalization reactions.
ChemInform Abstract: Iron(II)‐Catalyzed Oxidation of sp3 C—H Bonds Adjacent to a Nitrogen Atom of Unprotected Arylureas with tert‐Butyl Hydroperoxide in Water.
Authors: Wei Ying , Ding Hongqian , Lin Shaoxia , Liang Fushun
Published: June 2011

The reaction at 50 °C leads to formation of hydroxylated/tert‐butoxylated products.
ChemInform Abstract: NBS or DEAD as Effective Reagents in α‐Thiocyanation of Enolizable Ketones with Ammonium Thiocyanate.
Authors: Reddy B. V. Subba , Reddy S. Madhu Sudana , Madan Ch.
Published: June 2011

In general, NBS‐promoted thiocyanations give higher yields of α‐thiocyanatoketones and require shorter reaction times compared to DEAD‐promoted thiocyanations.
ChemInform Abstract: A New Synthetic Protocol for the Preparation of Carbodiimides Using a Hypervalent Iodine(III) Reagent.
Authors: Zhu Chenjie , Xu Dan , Wei Yunyang
Published: June 2011

A simple, mild, and highly efficient system is developed for the preparation of the title compounds (II).
ChemInform Abstract: Ligand‐Free Suzuki—Miyaura Cross‐Coupling Reactions of Aryltriazenes with Arylboronic Acids.
Authors: Nan Guangming , Zhu Fanghua , Wei Zhijun
Published: June 2011

The boron trifluoride‐induced Suzuki‐Miyaura cross‐coupling of aryltriazenes with arylboronic acids catalyzed by palladium(II) acetate without added ligands is achieved for the first time.
ChemInform Abstract: Oxygen‐Promoted PdCl2‐Catalyzed Ligand‐Free Suzuki Reaction in Aqueous Media.
Authors: Liu Chun , Ni Qijian , Hu Pingping , Qiu Jieshan
Published: June 2011

Investigations in different solvents reveal that an aerobic atmosphere could accelerate the Suzuki reaction in aqueous media.
ChemInform Abstract: Gold‐Catalyzed Synthesis of Benzil Derivatives and α‐Keto Imides via Oxidation of Alkynes.
Authors: Xu Cheng‐Fu , Xu Mei , Jia Yi‐Xia , Li Chuan‐Ying
Published: June 2011

A straightforward and efficient method to prepare 1,2‐diaryldiketones and α‐keto imides is reported.
ChemInform Abstract: Phosphoric Acid‐Catalyzed Enantioselective Transfer Hydrogenation of N‐Aryl‐ortho‐hydroxybenzophenone Ketimines.
Authors: Nguyen Thanh Binh , Bousserouel Hadjira , Wang Qian , Gueritte Francoise
Published: June 2011

Transfer hydrogenation of title ketimines (I) with Hantzsch ester proceeds efficiently in the presence of a chiral BINOL‐derived phosphoric acid catalyst to give the corresponding diarylmethylamines (II) in good yields and enantioselectivities (up to 91% e.e.).
ChemInform Abstract: Cycloisomerization of Bifunctionalized Allenes: Synthesis of 3(2H)‐Furanones in Water.
Authors: Poonoth Manojkumar , Krause Norbert
Published: June 2011

Treatment of allenic hydroxyketones with aqueous NaOH provides a new and simple approach to 3‐furanones.
ChemInform Abstract: Rhodium‐Catalyzed Carbene‐Transfer Reactions via Thienylcarbene Complexes Generated from Thiocarbamoyl‐ene‐yne Compounds.
Authors: Tsuneishi Asuka , Okamoto Kazuhiro , Ikeda Yuji , Murai Masahito , Miki Koji , Ohe Kouichi
Published: June 2011

Ene‐yne (I) as a carbene source reacts with furans, thiophenes and alkenes to produce ring‐opened products of heterocycles and cyclopropanes, respectively.
ChemInform Abstract: Gold(I)‐Catalyzed Intramolecular Amination of Allylic Alcohols with Alkylamines.
Authors: Mukherjee Paramita , Widenhoefer Ross A.
Published: June 2011

The process can be applied to a broad spectrum of amines for the synthesis of pyrrolidine and piperidine derivatives.
ChemInform Abstract: An Efficient Procedure for the Synthesis of Polysubstituted Pyrroles in an Ionic Liquid.
Authors: He Yan‐Hong , Wang Gang‐Qiang , Xu Ke‐Ling , Guan Zhi
Published: June 2011

A wide range of 1,4‐diketones easily undergoes condensation with aniline or ethylenediamine furnishing pyrroles using [bmim]HSO4 as catalyst and reaction medium.
ChemInform Abstract: Silver‐Catalyzed 1,3‐Dipolar Cycloaddition of Azomethine Ylides with β‐Boryl Acrylates.
Authors: Lopez‐Perez Ana , Segler Marwin , Adrio Javier , Carretero Juan C.
Published: June 2011

The title reaction allows highly stereoselective access to polysubstituted pyrrolidines.