bluuebunny/crossref_metadata_2025 huggingface dataset:
The Industrial Pharmacy Lab: New Concepts in Powder and Process Technology
Authors: Betz Gabriele
Published: June 2006

The Industrial Pharmacy Lab (IPL) was founded in 2001 and has been awarded the NETS Award and NETS Special Award of the Gebert Rüf Foundation, Basel in 2004. The IPL is a turning platform between the university and the pharmaceutical industry at the Pharma Hub Basel with the focus
on research in powder technology, dosage form design and scale-up. The IPL works with industrial-sized equipment and applies new and state-of-the-art technologies to the development of robust formulations. In the present article the research fields granulation process control, formulation
of low water soluble drugs, modified release, and impact of the filling process on protein solutions are introduced and critical parameters, sources of variability, and scale-up problems are identified in order to suggest and provide a rational and optimal formulation and process for pharmaceutical
dosage form design.
E-Learning and Development of New Courses and Scientific Work in the Field of Pharmaceutical Technology
Authors: Leuenberger Hans , Menshutina Natalia , Betz Gabriele , Puchkov Maxim N.
Published: June 2006

Since 2001, the Institute of Pharmaceutical Technology (IPT) at the University of Basel and the Mendeleyev University of Chemical Technology of Russia (MUCTR) have established an institutional partnership (IP), which is supported by the Swiss National Science Foundation (SNF) in the
framework of the SCOPES (Scientific Cooperation between Eastern Europe and Switzerland) project. The results of this collaboration are the new teaching technologies that were introduced at the MUCTR and the IPT. The former include multimedia lectures in pharmaceutical technology, which are
held in parallel at University of Basel and MUCTR, and the educational web-portal 'Pharmacy online', which was awarded a medal at the 4th Moscow International Salon of Innovations. The multimedia lectures are popular with and helpful for MUCTR students, because they can compensate to a certain
extent the lack of equipment at the MUCTR. However, multimedia lectures can never replace hands-on training and therefore the continuation of the collaboration is ongoing. In this respect SNF decided in 2005 to give continuous support for this cooperation through the grant entitled 'New Concepts
in Training Industrial Pharmacists and Pharmaceutical Engineers to Be Developed and Implemented at the Russian-Swiss Scientific and Education Centre in MUCTR'. This centre was established as a result of the previous grant. The development and implementation of a unique and innovative learning
concept on the basis of the Russian-Swiss scientific and educational centre involving the Russian pharmaceutical and biotechnological industry, is an ongoing activity.
Unravelling the Potential of Natural Products – Biological Profiling of Extracts and New Molecules
Authors: Hamburger Matthias
Published: June 2006

Natural products are highly useful as sources of drugs and as tools for fundamental biomedical research. Phytomedicines based on medicinal plants and herbal extracts are used worldwide. Using three examples from our lab, we have shown different approaches to explore the biological and
pharmacological properties of herbal extracts and new natural product leads. Our emphasis has been on global effects and multiple rather than single targets, whereby cell- and mechanism-based in vitro assays, in vivo pharmacology, cell biology and transcriptional profiling were
employed.
Dibenzothiophene/Oxide and Quinoxaline/Pyrazine Derivatives Serving as Electron‐Transport Materials
Authors: Huang T.‐H. , Whang W.‐T. , Shen J. Y. , Wen Y.‐S. , Lin J. T. , Ke T.‐H. , Chen L.‐Y. , Wu C.‐C.
Published: June 2006

A series of 2,8‐disubstituted dibenzothiophene and 2,8‐disubstituted dibenzothiophene‐S,S‐dioxide derivatives containing quinoxaline and pyrazine moieties are synthesized via three key steps: i) palladium‐catalyzed Sonogashira coupling reaction to form dialkynes; ii) conversion of the dialkynes to diones; and iii) condensation of the diones with diamines. Single‐crystal characterization of 2,8‐di(6,7‐dimethyl‐3‐phenyl‐2‐quinoxalinyl)‐5H‐5λ6‐dibenzo[b,d]thiophene‐5,5‐dione indicates a triclinic crystal structure with space group P1 and a non‐coplanar structure. These new materials are amorphous, with glass‐transition temperatures ranging from 132 to 194 °C. The compounds (Cpd) exhibit high electron mobilities and serve as effective electron‐transport materials for organic light‐emitting devices. Double‐layer devices are fabricated with the structure indium tin oxide (ITO)/Qn/Cpd/LiF/Al, where yellow‐emitting 2,3‐bis[4‐(N‐phenyl‐9‐ethyl‐3‐carbazolylamino)phenyl]quinoxaline (Qn) serves as the emitting layer. An external quantum efficiency of 1.41 %, a power efficiency of 4.94 lm W–1, and a current efficiency of 1.62 cd A–1 are achieved at a current density of 100 mA cm–2.
Generation of Self‐Assembled 3D Mesostructured SnO2 Thin Films with Highly Crystalline Frameworks
Authors: Brezesinski T. , Fischer A. , Iimura K.‐i. , Sanchez C. , Grosso D. , Antonietti M. , Smarsly B. M.
Published: June 2006

Crack‐free, mesoporous SnO2 films with highly crystalline pore walls are obtained by evaporation‐induced self‐assembly using a novel amphiphilic block‐copolymer template (“KLE” type, poly(ethylene‐co‐butylene)‐block‐poly(ethylene oxide)), which leads to well‐defined arrays of contracted spherical mesopores by suitable heat‐treatment procedures. Because of the improved templating properties of these polymers, a facile heat‐treatment procedure can be applied whilst keeping the mesoscopic order intact up to 600–650 °C. The formation mechanism and the mesostructural evolution are investigated by various state‐of‐the‐art techniques, particularly by a specially constructed 2D small‐angle X‐ray scattering setup. It is found that the main benefit from the polymers is the formation of an ordered mesostructure under the drastic conditions of using molecular Sn precursors (SnCl4), taking advantage of the large segregation strength of these amphiphiles. Furthermore, it is found that the crystallization mechanism is different from other mesostructured metal oxides such as TiO2. In the case of SnO2, a significant degree of crystallization (induced by heat treatment) already starts at quite low temperatures, 250–300 °C. Therefore, this study provides a better understanding of the general parameters governing the preparation of mesoporous metal oxides films with crystalline pore walls.
Linear Sweep Voltammetric Studies on the Interaction of Brilliant Cresyl Blue With Nucleic Acids and its Analytical Application
Authors: Sun Wei , You Jiayu , Gong Chaokun , Jiao Kui
Published: June 2006

In this paper, the interaction of brilliant cresyl blue (BCB) with nucleic acids was studied and further applied for the microdetermination of nucleic acids. In aqueous Britton‐Robinson (B‐R) buffer solution, BCB can be easily reduced on the hanging mercury drop electrode (HMDE) and had a sensitive voltammetric reduction peak at −0.09 V (vs. SCE). The reduction peak current of BCB could be greatly decreased by the addition of DNA. The results of voltammetric measurements had indicated that a binding reaction was occurred between BCB and DNA and a new supramolecular complex was formed, which resulted in the decrease of the diffusion coefficient of the reaction solution and the decrease of the reduction peak current correspondingly. The conditions of interaction and the electrochemical detection were carefully investigated. Under the selected conditions, the calibration curves for the detection of fish sperm (fs)DNA, calf thymus (ct)DNA and yeast (y)RNA were established. The linear range of this assay was 1.0‐30.0 μg/mL for fsDNA, 1.0‐45.0 μg/mL for ctDNA and 1.0‐25.0 μg/mL for yRNA, respectively. The detection limits were 0.38 μg/mL fsDNA, 0.43 μg/mL ctDNA, 0.64 μg/mL yRNA. The interaction parameters such as the equilibrium constant and the binding number were calculated by electrochemical method. The results showed that the 2:3 type of complex was formed in the fsDNA‐BCB complex with the binding constant as 2.51×107. The proposed method was further applied to the synthetic samples determination with satisfactory results.
Rapid Separation and Analysis of Six Organic Acids in Bayer Liquors by RP‐HPLC after Solid‐Phase Extraction
Authors: Xiao Jian Bo , Chen Xiao Qing , Jiang Xin Yu , Wu Sheng De
Published: June 2006

A rapid revised phase high‐performance liquid chromatographic (RP‐HPLC) method for the determination of six organic acids in Bayer liquors is reported. Oxalic, tartaric, acetic, succinic, glutaric and butene dicarboxylic acid were separated and quantified in 10 min. First time repeatability, reproducibility and recoveries were determined out for these acids in Bayer liquors. The organic acids were removed from Bayer liquor by using a solid‐phase extraction procedure with anion‐exchange cartridges. The chromatographic separation was achieved with only one Kromasil RP‐C18 column thermo stated at 25 °C. Organic acids were detected with a UV–vis detector (215 nm). The precision results showed that the relative standard deviations of the repeatability and reproducibility were <2.80% and <3.74%, respectively. The accuracy of the method was confirmed with an average recovery ranging between 85.2 and 107.3%. Under optimum conditions the detection limits ranged from 50 to 1000 mg/L.
Cover Picture: Multipotent Polymer Coatings Based on Chemical Vapor Deposition Copolymerization (Adv. Mater. 12/2006)
Authors: Elkasabi Y. , Chen H.‐Y. , Lahann J.
Published: June 2006

The cover shows that chemical vapor deposition can be used to prepare copolymer thin films, on varying substrates, that can bind two different ligands with high selectivity. In work reported by Lahann and co‐workers on p. 1521, the actual ligand ratios on the surface can be controlled by varying the copolymer composition. This technology may find applications in biomedical devices, high‐throughput screening platforms, microfluidic analysis devices, and diagnostic platforms.
Inside Front Cover: Nanoscale Surface Morphology and Rectifying Behavior of a Bulk Single‐Crystal Organic Semiconductor (Adv. Mater. 12/2006)
Authors: Menard E. , Marchenko A. , Podzorov V. , Gershenson M. E. , Fichou D. , Rogers J. A.
Published: June 2006

Local surface measurements of rubrene single crystals reveal interesting insights on carrier‐transport mechanisms at the active interface of high‐performance field‐effect “air‐gap stamp” transistors, as reported by Fichou, Rogers, and co‐workers on p. 1552. Scanning tunneling microscopy (STM, tip shown schematically) images, combined with atomic force microscopy and X‐ray diffraction, reveal directly the position and orientation of individual molecules in the a–b plane. Local current–voltage curves recorded using STM in the dark and under illumination indicate a rectifying p‐type behavior.
Nylon 6/CB polymeric conductive plastic bipolar plates for PEM fuel cells
Authors: Chen Chao‐Kuang , Kuo Jenn‐Kun
Published: June 2006

Bipolar plate materials are a potential alternative to the graphite sheets currently used in proton exchange membrane fuel cells (PEMFCs). These materials must be of low‐cost, easy to fabricate, light, strong, mechanically stable, and have a low surface contact resistance if they are to be widely applicable. Nylon 6 polymer thermoplastic and carbon black (CB, 100–600 nm) blends have nanoparticle carbon (30–50 nm), high electrical and thermal conductivity, and good gas tightness properties. These composites are suitable for the mass fabrication of bipolar plates using an injection molding process. In this study, various Nylon 6/CB composites are used to fabricate bipolar‐parallel‐plate gas‐flow channel. The bipolar plates are fabricated with three different gas flow channel configurations, namely serpentine, grid, and branch. The bipolar plates are then used in the construction of PEMFCs. The temperature effect on the resistivity of the Nylon 6/CB polymeric composite is investigated and the voltage–current curves and power density–current curves obtained from the different PEMFCs are analyzed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3415–3421, 2006
Effect of charge density, molecular weight, and hydrophobicity on polycations adsorption and flocculation of polystyrene latices and silica
Authors: Schwarz S. , Bratskaya S. , Jaeger W. , Paulke B.‐R.
Published: June 2006

Adsorption and flocculation behavior of two series of synthetic polycations was investigated in dispersions of silica and polystyrene latices with various particle size and surface charge densities. Polycations of the first series (polydiallyldimethyl ammonium chloride‐PDADMAC) varied in molecular weight only, while polycations of the second series (derivatives of polymethacrylic acid) varied in both molecular weight and hydrophobicity. We have found that maximum adsorbed amount of high molecular weight PDADMAC on latex particles was nearly independent of the surface charge density when the particle size was comparable to the polymer coil dimensions in solution. Both low and high molecular weight PDADMACs were efficient flocculants, although significantly lower amounts of high molecular weight polyelectrolyte were required for the phase separation in the dispersions due to particles aggregation through “charge patch” mechanism. The increase of polymer hydrophobicity leads to higher adsorbed amounts and broadening of flocculation window by polycations of the second series on both substrates. However, no strong enhancement of segment–surface interactions on hydrophobic substrates was observed. Since formation of multilayers upon adsorption was also excluded, the difference in adsorption and flocculation behavior was related to the more compact conformation of hydrophobically associating derivatives in solution and at the interface. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3422–3429, 2006
Synthesis and characterization of fluorine and nitrile containing polyimides
Authors: Raju M. Padmanabha , Alam Sarfaraz
Published: June 2006

A series of polyimides were synthesized from new diamine, Bis [4,4′‐amino‐5,5′ trifluoromethyl phenoxy‐(hexafluoro isopropylidine) phenoxy phenyl] benzonitrile [BATFB] and various aromatic tetracarboxylic anhydrides by thermal and chemical imidization routes. The BATFB was synthesized in two steps by nucleophilic displacement reaction of 2,6‐dichloro benzonitrile, 4,4′‐(hexafluoro isopropylidine) diphenol and 2‐amino‐5‐fluoro benzotrifluoride in the presence of anhydrous potassium carbonate in N,N′‐dimethyl acetamide (DMAc) and the structure was confirmed by FTIR spectroscopy and CHNSO analyzer. The polymers were characterized by FTIR spectroscopy and thermal analysis were performed by differential scanning calorimetry and thermogravimetric analysis methods. The prepared polyimides had glass transition temperatures between 230 and 290°C and their 10% weight loss were recorded in the range 550–590°C in N2 atmosphere. Majority of polymers are found to be soluble in most of the organic solvents such as DMSO, DMF, DMAc, m‐cresol, and THF even at room temperature and few becomes soluble on heating. The prepared polyimides showed water uptake values 0.34–0.54 wt % at room temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3455–3461, 2006
Binding behavior of Fe3+ ions on ion‐imprinted polymeric beads for analytical applications
Authors: Saatçılar Özgen , Şatıroğlu Nuray , Say Rıdvan , Bektas̨ Sema , Denizli Adil
Published: June 2006

We used a molecular imprinting approach to achieve specific metal binding utilizing N‐methacryloyl‐(L)‐cysteine methyl ester (MAC) as a metal‐complexing ligand. MAC was synthesized using methacryloyl chloride and cysteine methyl ester. Then, Fe3+ was complexed with MAC monomer. Fe3+‐imprinted poly(hydroxyethyl methacrylate‐N‐methacryloyl‐(L)‐cysteine methyl ester) [poly(HEMA‐MAC)] beads with average size of 63–140 μm were produced by suspension polymerization. After that, the template ions (i.e. Fe3+ ions) were removed by 0.1M HCl. Fe3+‐imprinted beads were characterized by swelling studies, FTIR, and elemental analysis. The Fe3+‐imprinted beads with a swelling ratio of 72%, and containing 3.9 mmol MAC/g were used in the binding of Fe3+ ions from aqueous solutions, tap water, certified reference serum sample, and real serum sample. Maximum binding capacity, optimum pH, and equilibrium binding time were 107 μmol/g, pH 3.0, and 30 min, respectively. It was observed that even in the presence of other ions, Fe3+‐imprinted beads selectively bound Fe3+ ions with 97% efficiency. Removal of Fe3+ ions from certified reference serum sample was approximately found to be 33%. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3520–3528, 2006
Synthesis of polymeric nanofiber and polymeric nanosphere by living free radical polymerization
Authors: Lee Jou‐Hwa , Liao Yih‐Tyan
Published: June 2006

Living free radical polymerizations are employed to synthesize the polystyrene copolymer. The applications of those copolymer in nanomaterials are elucidated in this research. It involves the copolymerization of styrene with 2‐hydroxyethyl methacrylate. The copolymers are reacted with cinnamoyl chloride, and then irradiated with UV light. The polymeric nanofibers are formed by solvent splitting. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3550–3558, 2006
Im Dienste der Wissenschaft: Der Centro de estudios históricos und die Begründung eines liberalen Nationalbewußtseins in Spanien (1910–1936)
Authors: López Sánchez José María
Published: June 2006

In the Name of Science: the Centro de Estudios Históricos and the shaping of a liberal national conciousness in Spain (1910–1936). – The Centro de Estudios Históricos was founded in 1910 by the Junta para Ampliación de Estudios. The main goal was to create a modern scientific system, but the researchers of the Centro also attempted to reinterpret some aspects of the Spanish Culture. We also try to have a new insight into how Spanish History and Culture was apprehended by those intelectuals in order to create the cultural basis of a new Spanish nationalism. The philological school of Menéndez Pidal or the historical school of Sánchez‐Albornoz played an active role in trying to find out the cultural roots of the Spanish Culture. They strived for providing the Spanish nation a cultural background.
An assay for inorganic mercury(II) based on its post‐catalytic enhancement effect on the potassium permanganate–luminol system
Authors: Hu Shangwei , Liu Weibing , Huang Yuming , Shu Weiqun , Cao Jia
Published: June 2006

A strong chemiluminescence (CL) response is observed when potassium permanganate solution is injected into basic luminol solution. When the CL reaction terminates, subsequent injection of Hg2+ solution into the reaction mixture results in a new CL reaction. Based on the post‐catalytic enhancement effect of Hg2+ on the potassium permanganate–luminol system in basic media, a fast and simple CL‐coupled flow injection analysis for the determination of Hg2+ was developed. In optimum conditions, CL intensity is proportional to Hg2+ concentration over the range 1.0 × 10−8–1.0 × 10−5 g/mL, with a detection limit of 2.0 × 10−9 g/mL. The relative standard deviation (RSD) is 3.6% for 1.0 × 10−7 g/mL Hg2+ (n = 11). After pretreatment with sulphydryl cotton fibre, environmental water samples were analysed by the proposed method for total mercury determination with satisfactory results. The results were in good agreement with those given by hydride generation–cold vapour atomic absorption spectrometry (HG–CVAAS). Copyright © 2006 John Wiley & Sons, Ltd.
Synthetic Ligands Able to Interact with the P53 Tetramerization Domain. Towards Understanding a Protein Surface Recognition Event
Authors: Martinell Marc , Salvatella Xavier , Fernández‐Carneado Jimena , Gordo Susana , Feliz Miguel , Menéndez Margarita , Giralt Ernest
Published: June 2006

The applied interaction of synthetic molecules with defined regions of protein surfaces is an emerging strategy for the modulation of protein activity and/or stability. In spite of recent advances, the design of these molecules is not trivial. Among the most challenging aspects in designing these compounds is that they must compete with water molecules for interaction with polar patches of protein surfaces. Herein is reported the preparation of an arginine‐rich peptide that interacts in aqueous solution with a very hydrophilic patch at the surface of the tetramerization domain of the tumor suppressor protein p53. The interaction has been studied by several complementary techniques. By using this peptide as a template, a library of peptides has been prepared and evaluated in order to examine the different factors that contribute to the recognition event. The conclusions extracted from this work could be useful for the design of ligands directed at highly hydrophilic protein surface patches.
Inactivation of gilGT, Encoding a C‐Glycosyltransferase, and gilOIII, Encoding a P450 Enzyme, Allows the Details of the Late Biosynthetic Pathway to Gilvocarcin V to be Delineated
Authors: Liu Tao , Kharel Madan Kumar , Fischer Carsten , McCormick Andrew , Rohr Jürgen
Published: June 2006

Resequencing of the gilGT gene, which encodes a putative glycosyltransferase (GT) that is 495 amino acids (aa) long, from the Streptomyces griseoflavus Gö3592 gilvocarcin V (GV) gene cluster, revealed that the previously reported gilGT indeed contains two genes. These are the larger gilGT, which encodes the C‐glycosyltransferase GilGT (379 aa), and the smaller gilV gene, which encodes an enzyme of unknown function (116 aa). The gene gilV is located immediately upstream of gilGT in the GV gene cluster. In‐frame deletion of gilGT created a mutant that accumulated defucogilvocarcin E (defuco‐GE). The result proves the function of GilGT as a C‐glycosyltransferase. Deletion of gilOIII, which is located immediately downstream of gilGT, led to a mutant that accumulated gilvocarcin E (GE). This confirms that the corresponding P450 enzyme, GilOIII, is involved in the vinyl‐group formation of GV. Cross‐feeding experiments in which GE, defuco‐GE, and defucogilvocarcin V (defuco‐GV) were fed to an early blocked mutant of the GV biosynthetic pathway, showed that neither GE nor any of the defuco‐ compounds was an intermediate of the pathway.
Cover Picture: Photoactivation of an Inhibitor of the 12/15‐Lipoxygenase Pathway (ChemBioChem 7/2006)
Authors: Herre Stephan , Schadendorf Torsten , Ivanov Igor , Herrberger Christian , Steinle Wencke , Rück‐Braun Karola , Preissner Robert , Kuhn Hartmut
Published: June 2006

The cover picture shows the alignment of the two geometric isomers (E isomer in blue, Z in turquoise) of 2‐(3‐benzylidene)‐3‐oxo‐2,3‐dihydrobenzo[b]thiophene‐7‐carboxylic acid methyl ester at the active site of rabbit 12/15‐lipoxygenase. In the Z configuration, the benzoyl moiety conflicts with the side chain of the C‐terminal I663, which normally ligates the catalytic non‐heme iron. Light irradiation induces Z‐to‐E isomerization, which flips the benzoyl ring over towards I593, the side chain of which limits the depth of the substrate binding pocket. There are no steric constraints for binding of the E isomer. Further details can be found in the article by H. Kuhn et al. on p. 1089 ff.
Expanding the Substrate Scope of Enzymes: Combining Mutations Obtained by CASTing
Authors: Reetz Manfred T. , Carballeira José Daniel , Peyralans Jérôme , Höbenreich Horst , Maichele Andrea , Vogel Andreas
Published: June 2006

In a previous paper, the combinatorial active‐site saturation test (CAST) was introduced as an effective strategy for the directed evolution of enzymes toward broader substrate acceptance. CASTing comprises the systematic design and screening of focused libraries around the complete binding pocket, but it is only the first step of an evolutionary process because only the initial libraries of mutants are considered. In the present study, a simple method is presented for further optimization of initial hits by combining the mutational changes obtained from two different libraries. Combined lipase mutants were screened for hydrolytic activity against six notoriously difficult substrates (bulky carboxylic acid esters) and improved mutants showing significantly higher activity were identified. The enantioselectivity of the mutants in the hydrolytic kinetic resolution of two substrates was also studied, with the best mutant–substrate combination resulting in a selectivity factor of E=49. Finally, the catalytic profile of the evolved mutants in the hydrolysis of simple nonbranched carboxylic acid esters, ranging from acetate to palmitate, was studied for theoretical reasons.
Structural Studies of 1‐Butyl‐3‐methylimidazolium Tetrafluoroborate/TX‐100/ p‐Xylene Ionic Liquid Microemulsions
Authors: Gao Yan'an , Zhang Jin , Xu Hongyan , Zhao Xueyan , Zheng Liqiang , Li Xinwei , Yu Li
Published: June 2006

The ionic liquid (IL) 1‐butyl‐3‐methylimidazolium tetrafluoroborate (bmimBF4) forms nonaqueous microemulsions with p‐xylene, with the aid of the nonionic surfactant TX‐100. The phase behavior of the ternary system is investigated, and three microregions of the microemulsions—ionic liquid‐in‐oil (IL/O), bicontinuous, and oil‐in‐ionic liquid (O/IL)—are identified by conductivity measurements, according to percolation theory. On the basis of a phase diagram, a series of IL/O microemulsions are chosen and characterized by dynamic light scattering (DLS). The size of aggregates increases on increasing the amount of added polar component (bmimBF4), which is a similar phenomenon to that observed for typical water‐in‐oil (W/O) microemulsions, suggesting the formation of IL/O microemulsions. The microstructural characteristics of the microemulsions are investigated by FTIR and 1H NMR spectroscopy. The results indicate that the interaction between the electronegative oxygen atoms of the oxyethylene (OE) units in TX‐100 and the electropositive imidazolium ring may be the driving force for the solubilization of bmimBF4 into the core of the TX‐100 aggregates. In addition, the micropolarity of the microemulsions is investigated by using methyl orange (MO) as a UV/Vis spectroscopic probe. A relatively constant polarity of the microemulsion droplets is obtained in the IL microemulsion. Finally, a plausible structure for the IL/O microemulsion is presented.
Oriented Ensembles in Ultrafast Electron Diffraction
Authors: Baskin J. Spencer , Zewail Ahmed H.
Published: June 2006

Electron scattering expressions are presented which are applicable to very general conditions of implementation of anisotropic ultrafast electron diffraction (UED) experiments on the femto‐ and picosecond time scale. “Magic angle” methods for extracting from the experimental diffraction patterns both the isotropic scalar contribution (population dynamics) and the angular (orientation‐dependent) contribution are described. To achieve this result, the molecular scattering intensity is given as an expansion in terms of the moments of the transition‐dipole distribution created by the linearly polarized excitation laser pulse. The isotropic component (n=0 moment) depends only on population and scalar internuclear separations, and the higher moments reflect bond angles and evolve in time due to rotational motion of the molecules. This clear analytical separation facilitates assessment of the role of experimental variables in determining the influence of anisotropic orientational distributions of the molecular ensembles on the measured diffraction patterns. Practical procedures to separate the isotropic and anisotropic components of experimental data are evaluated and demonstrated with application to reactions. The influence of vectorial properties (bond angles and rotational dynamics) on the anisotropic component adds a new dimension to UED, arising through the imposition of spatial order on otherwise randomly oriented ensembles.
Mauer und Wand: Teil 1
Authors: Bode Udo F. W.
Published: June 2006

Wände wurden historisch der ihnen zugedachten Funktion als Mauern und Wände unterschieden. Die Mauern stellten als Außenwände die Begrenzung von innen und außen dar, und ihnen wurden Tragfunktionen zugeordnet. Im Unterschied dazu dienten die Innenwände vorrangig der Raumunterteilung ohne deutliche Tragfunktion. Die stärkere Differenzierung nach einwirkenden Kräften und der Ermittlung empirischer Stabilitätskriterien führte während des 17. bis führen 19. Jh. zu unserem heutigen Verständnis, nach tragenden und raumbegrenzenden Wänden zu unterscheiden. Nachfolgend wird eine kurze Übersicht dieser Entwicklung aufgezeigt.
Bapx1 homeobox gene gain‐of‐function mice show preaxial polydactyly and activated Shh signaling in the developing limb
Authors: Tribioli Carla , Lufkin Thomas
Published: June 2006

To explore Bapx1 homeobox gene function in embryonic control of development, we employed a gain‐of‐function approach to complement our previous loss‐of‐function mutant analysis. We show that transgenic mice overexpressing Bapx1 are affected by skeletal defects including hindlimb preaxial polydactyly and tibial hypoplasia. Bapx1 overexpression generates limb anteroposterior patterning defects including induction of Shh signaling and ectopic activation of functions downstream of Shh signaling into the anterior region of the autopod. Moreover, Bapx1 overexpression stimulates formation of limb prechondrogenic condensations. We also show that Shh is reciprocally able to activate Bapx1 expression in mouse embryos as the orthologous hedgehog (hh) does with the bagpipe/Bapx1 gene in Drosophila. Our results indicate that Bapx1 can modulate appendicular skeletal formation, that the genetic hierarchy between Shh/hh and Bapx1/bagpipe has been conserved during evolution, and that in mouse embryos these two genes can influence one another in a genetically reciprocal manner. We conclude that it is reasonable to expect overexpression of Bapx1 in certain forms of polydactyly. Developmental Dynamics 235:2483–2492, 2006. © 2006 Wiley‐Liss, Inc.
Synthesis, Structure, and Magnetic Behavior of Two New 1D Polymeric Manganese Azido Complexes
Authors: Abu‐Youssef Morsy A. M. , Escuer Albert , Langer Vratislav
Published: June 2006

Two new MnII one‐dimensional compounds with formulae [Mn(μ‐N3)2(pyzamid)2]n (1) and [Mn2(3‐ampy)4(μ‐N3)2(N3)2(H2O)2]n, (2) (pyzamid = pyrazineamide and 3‐ampy = 3‐aminopyridine) were structurally and magnetically characterized. Compound 1 crystallizes in the monoclinic system, P2/c space group, and polymerizes through double end‐on azido bridges giving 1D chains with the MnII atoms in a MnN6 environment. Compound 2 crystallizes in the triclinic system, P$\bar {1}$ space group, and consists of alternate [Mn(3‐ampy)2(μ‐N3)2(N3)2] and [Mn(3‐ampy)2(μ‐N3)2(H2O)2] octahedrons (MnN6 – MnN4O2 environments), linked by single end‐to‐end azido bridges. Both chains show very uncommon topologies. Attemps to obtain manganese/azido derivatives with the qux = quinoline‐4‐carboxylato anion gave the recently reported compound [Mn(μ‐qux)2(μ‐H2O)]n (3), which consists of a chain with only carboxylato and aqua bridges with the MnII atoms in a MnO6 slightly distorted octahedron. In good agreement with the expected behavior, magnetic susceptibility measurements show weak ferromagnetic interactions for 1, whereas compound 2 exhibits moderate antiferromagnetic coupling.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Chiral Organometallic Catalysts in Confined Nanospaces: Significantly Enhanced Enantioselectivity and Stability
Authors: Song Choong Eui , Kim Dong Hyun , Choi Doo Seoung
Published: June 2006

This microreview presents some selected representative examples which demonstrate that significant improvement in the catalytic performance (increase in catalytic activity, stability and chemo‐ and enantioselectivity) of organometallic chiral catalysts as well as their recycling ability can be achieved by heterogenizing them in the confined spaces of porous or layered support materials. The positive effects of immobilization on the catalytic efficiencies are discussed in terms of the confinement effect and site‐isolation effect, etc., with the aim of understanding the extent to which such effects lead to positive changes in the catalytic properties. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Conformationally Biased Selective Alkylation of trans‐Cyclohexane‐1,2‐bis(sulfonamide) Assisted by Solvent‐Tuned Protecting Groups: Applications to the Synthesis of a Large Optically Active Polyazamacrocycle
Authors: Peña Carmen , Alfonso Ignacio , Gotor Vicente
Published: June 2006

The selective alkylation of (R,R)‐cyclohexane‐1,2‐bis(sulfonamide) with trityl bromoalkyl ethers has been studied in detail. The major formation of either mono‐ or dialkylated compounds clearly depends on the right combination of protecting groups and the reaction solvent. An exhaustive study suggests that this effect can be reasonably explained by the conformational preferences of the monoalkylated compounds, which also depend on the reaction medium, solvophobic effects and weak intramolecular interactions. Structural analysis by NOE measurements showed the presence of folded conformations in solution for all the tested examples. Monte Carlo conformational searches supported this proposal, showing a very good correlation between the fraction of folded species and the selectivity towards monoalkylation. Finally, tuning of the reaction conditions, leading to either extended or folded conformations of the monoalkylated synthetic intermediates, was exploited for the efficient synthesis of a large optically active polyazamacrocycle. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Comparison between Nafion® and a Nafion® Zirconium Phosphate Nano‐Composite in Fuel Cell Applications
Authors: Bauer F. , Willert‐Porada M.
Published: June 2006

A comparative investigation of the electrical, mechanical, and chemical behaviour of zirconium phosphate‐Nafion® composite membranes and Nafion® by means of ex‐situ measurements, as well as with fuel cell operation, reveals a slight reduction of ionic conductivity, a significant improvement of mechanical stability, and increased water retention for the composite materials. The overall efficiency at 130 °C is increased during direct methanol fuel cell (DMFC) operation because the reduction in the ionic conductivity is overcompensated for by the decrease in methanol crossover. With H2 as the fuel, the slight reduction in overall efficiency corresponds to the decrease in ionic conductivity. The dimensional stability of the membrane and the membrane electrode assembly (MEA) is significantly improved for operating temperatures above 100 °C. A model for the microstructure‐property relation for PFSA‐Zr(HPO4)2 · n H2O composite membranes is presented, based on the experimental results from membranes with varying filler contents and distributions, obtained through different synthesis routes. It is aimed at the improvement of water distribution in the membrane upon fuel cell operation.
MicroRNA: A new player in stem cells
Authors: Zhang Baohong , Pan Xiaoping , Anderson Todd A.
Published: June 2006

microRNAs (miRNAs) are an abundant class of endogenous non‐protein‐coding small RNAs, which negatively regulate gene expression at the posttranscriptional level in many developmental and metabolic processes. miRNAs regulate a variety of biological processes, including developmental timing, signal transduction, tissue differentiation and maintenance, disease, and carcinogenesis. Emerging evidence demonstrates that miRNAs also play an essential role in stem cell self‐renewal and differentiation. Some miRNAs are specifically expressed in stem cells, control stem cell self‐renewal, and differentiation through negatively regulating the expression of certain key genes in stem cells. J. Cell. Physiol. 209: 266–269, 2006. © 2006 Wiley‐Liss, Inc.
Synergistic extraction of rare earths(III) from chloride medium with mixtures of 1‐phenyl‐3‐methyl‐4‐benzoyl‐pyrazalone‐5 and di‐(2‐ethylhexyl)‐2‐ethylhexylphosphonate
Authors: Zhao Junmei , Meng Shulan , Li Deqian
Published: June 2006

The synergistic effect of 1‐phenyl‐3‐methyl‐4‐benzoyl‐pyrazalone‐5 (HPMBP, HA) and di‐(2‐ethylhexyl)‐2‐ethylhexylphosphonate (DEHEHP, B) in the extraction of rare earths (RE) from chloride solutions has been investigated. Under the experimental conditions used, there was no detectable extraction when DEHEHP was used as a single extractant while the amount of RE(III) extracted by HPMBP alone was also low. But mixtures of the two extractants at a certain ratio had very high extractability for all the RE(III). For example, the synergistic enhancement coefficient was calculated to be 9.35 for Y3+, and taking Yb3+and Y3+as examples, RE3+is extracted as RE(OH)A2.B. The stoichiometry, extraction constants and thermodynamic functions such as Gibbs free energy change ΔG(−17.06 kJ mol−1), enthalpy change ΔH(−35.08 kJ mol−1) and entropy change ΔS(−60.47 J K−1mol−1) for Y3+at 298 K were determined. The separation factors (SF) for adjacent pairs of rare earths were calculated. Studies show that the binary extraction system not only enhances the extraction efficiency of RE(III) but also improves the selectivity, especially between La(III) and the other rare earth elements. Copyright © 2006 Society of Chemical Industry
Estimate of vascular permeability and cerebral blood volume using Gd‐DTPA contrast enhancement and dynamic T2*‐weighted MRI
Authors: Cao Yue , Shen Zhen , Chenevert Thomas L. , Ewing James R.
Published: June 2006

Purpose

To develop a numerical approach for estimation of vascular permeability from dynamic T2*‐weighted imaging, a technique routinely used to measure cerebral blood volume (CBV) and flow in gliomas.

Materials and Methods

This study describes a process for estimating both the gadolinium diethylenetriamine pentaacetic acid (Gd‐DTPA) transvascular transfer constant and CBV from dynamic T2*‐weighted images. The algorithm was applied to data from the brains of 12 patients with grade IV gliomas. The stability of the method was assessed. Estimates of CBV by this technique were compared to those of the conventional method.

Results

The algorithm was found to be insensitive to noise and to generate stable voxel‐by‐voxel estimates of permeability and CBV.

Conclusion

Using a single imaging acquisition, the three most important vascular properties, CBV, cerebral blood flow (CBF), and permeability, can be estimated. This approach may have potential in clinical evaluation of patients with brain tumor or acute ischemic stroke. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Variable MR findings in ovarian functional hemorrhagic cysts
Authors: Kanso Hassan N. , Hachem Kamal , Aoun Noël J. , Haddad‐Zebouni Soha , Klein‐Tomb Laurence , Atallah David , Buy Jean‐Noël , Ghossain Michel A.
Published: June 2006

Purpose

To describe the magnetic resonance (MR) findings in ovarian functional hemorrhagic cysts (FHC).

Materials and Methods

A total of 21 patients with 22 FHC, proven by follow‐up ultrasound (US) in 11 women and surgery in 10 women, had US and MR examinations within 24 hours. The study was limited to cysts with obvious an echogenic pattern. All patients had T2‐weighted fast spin echo (FSE), T1‐weighted spin echo (SE), and T1‐weighted SE fat‐suppressed sequences.

Results

Four cysts (18%) were hypointense on T1‐weighted‐images without and with fat suppression, and hyperintense on T2‐weighted‐images. Five cysts (23%) were hypointense on T1‐weighted images without and with fat suppression but heterogenous on T2‐weighted images. Five cysts (23%) were hypointense on T1‐weighted images but showed intermediate signal intensity on T1‐weighted fat suppression images and heterogenous signal intensity on T2‐weighted images. Two cysts (9%) were entirely intermediate on T1‐weighted images. Five cysts (23%) displayed high signal intensity occupying less than 30% of the cystic content on T1‐weighted images and one cyst (5%) displayed high signal intensity occupying more than 30% of the cystic content.

Conclusion

Despite an obvious echogenic pattern on US, 64% of FHC were hypointense on T1‐weighted images and 18% were also hyperintense on T2‐weighted images. Only 36% demonstrated intermediate or high signal intensity on T1‐weighted images. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Sticking to our guns: social identity as a basis for the maintenance of commitment to faltering organizational projects
Authors: Haslam S. Alexander , Ryan Michelle K. , Postmes Tom , Spears Russell , Jetten Jolanda , Webley Paul
Published: June 2006

What leads some people to maintain commitment to faltering organizational projects while others abandon them? Building on previous work that has examined the link between social identity and the characteristics of decision‐making associated with groupthink, this paper argues that one key determinant of continued commitment to group projects is the extent to which group members define themselves in terms of a shared social identity rather than as individuals. This hypothesis is tested in two experiments that manipulate social identity salience and monitor attitudinal and financial commitment to an organizational project that encounters increasing difficulties over time. As predicted, in both studies, experimentally induced social identification leads to sustained commitment to the project across three temporal phases, while individuation of participants leads to a loss of faith and reduced financial commitment. These results contribute to theoretical understanding of the important role played by social identity in unfolding patterns of organizational and team commitment. Copyright © 2006 John Wiley & Sons, Ltd.
Arabinoxylans and endoxylanases in refrigerated dough syruping
Authors: Courtin Christophe M , Gys Wouter , Delcour Jan A
Published: June 2006

Refrigerated doughs of high quality have a long shelf life without loss of organoleptic properties. A major problem is the development of a liquid layer at the dough surface after prolonged storage, referred to as dough syruping. We here present a state‐of‐the‐art overview of the involvement of wheat flour arabinoxylan and wheat flour associated endoxylanases in this phenomenon and on ways to prevent or delay the occurrence of dough syrup upon prolonged storage of refrigerated doughs. Copyright © 2006 Society of Chemical Industry
Development of different damage pathways in Norway lobster (Nephrops norvegicus) stored under different chilling systems
Authors: Losada Vanesa , Rodríguez Óscar , Miranda José M , Barros‐Velázquez Jorge , Aubourg Santiago P
Published: June 2006

Slurry ice is a biphasic system that has recently shown a number of advantages when employed as a chilling medium for fish species. Its use for a crustacean species of high commercial value, Norway lobster (Nephrops norvegicus), was evaluated in parallel with traditional flake icing. Quality parameters related to microbial spoilage and biochemical breakdown (aerobe and psychrotroph counts, pH, K value, total volatile amines, trimethylamine, free fatty acids and non‐enzymatic browning reactions) were assessed and compared with sensory (carapace, eyes, gills, odour and flesh) acceptability. Storage in slurry ice produced a significant (P < 0.05) inhibitory effect on both microbial growth (as determined by aerobes, psychrotrophs and volatile amines) and autolysis breakdown (as determined by K values and the release of free fatty acids) in comparison with the flake ice batch. In contrast, an enhancement effect of slurry ice on carapace browning was observed as a result of enzymatic browning development. Slurry ice batch also showed a more intense non‐enzymatic browning reaction in the lipid extract of the edible flesh. With a view to limiting both browning effects, the incorporation of an anti‐melanosis agent in the liquid phase of the slurry ice system is envisaged. Copyright © 2006 Society of Chemical Industry
Structure Determination of Polyacetals by Liquid Chromatography and Hyphenated Techniques
Authors: Rittig Frank , Fandrich Nick , Urtel Melanie , Schrepp Wolfgang , Just Ulrich , Weidner Steffen M.
Published: June 2006

Summary: The structure of polyacetal copolymers with respect to their end groups is investigated. Several techniques, such as liquid chromatography, MALDI‐TOF MS, IR and NMR spectroscopy, as well as combined techniques like 2D chromatography have been applied. Cyclic oligomers and polymers with formyl, hydroxy, and aliphatic end groups are identified. 2D chromatography shows that all the separated species are homogenously distributed with respect to their molar mass.

2D chromatograms of sample F97B3.

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2D chromatograms of sample F97B3.
Simple Trends in the Methylene Regions of the NMR Spectrum of Poly(propylene) and Ethylene‐Propylene Copolymers
Authors: Monaco Guglielmo , Sessa Irene , Zambelli Adolfo
Published: June 2006

Summary: The configurational sensitivity of the chemical shift of methylene carbons has been analyzed theoretically in terms of a perturbative approach. Theoretical results and computations have been applied successfully to new experimental data obtained from model compounds of the ${\rm S}_{\alpha \beta}$ resonance. It has been shown that the carbon in $\beta$ position with respect to the first methine of a regioregular sequence follows the same simple trend of the corresponding carbon atoms in $\alpha$ position. The tiny chemical shift spreadings of the ${\rm S}_{\alpha \beta}$ resonance due to the relative configuration of the nearest methyl groups in $\alpha$ and $\beta$ position showed a single inversion with respect to theoretical expectation.

Decomposition of a chain in subchains.

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Decomposition of a chain in subchains.
3D fluoroscopy with real‐time 3D non‐cartesian phased‐array contrast‐enhanced MRA
Authors: Brodsky Ethan , Isaacs David , Grist Thomas M. , Block Walter F.
Published: June 2006

For optimized CE‐MRA of the chest and abdomen, the scan time and breath‐hold must be coordinated with the arrival of contrast. A 3D fluoroscopy system is demonstrated that performs real‐time 3D projection reconstruction acquisition, reconstruction, and visualization using only the standard scanner hardware and operator console workstation. Unlike 2D fluorotriggering techniques, no specification of a monitoring slab or careful placement of the imaging volume is required. 3DPR data are acquired continuously throughout the examination using an eight‐channel receiver and 1 s interleaved subframes. The data are reconstructed using 1 s segments for real‐time monitoring with 0.8‐cm isotropic spatial resolution over the entire torso, allowing full‐volume axial, coronal, and sagittal MIPs to be displayed simultaneously with minimal latency. The system later uses the same scan data to generate high‐spatial‐resolution time‐resolved sequences of the breath‐hold interval. The 3D fluoroscopy system was validated on phantoms and human volunteers. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.