bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure of dental hard tissues in fossil and recent xenarthrans (Mammalia: Folivora and Cingulata)
Authors: Kalthoff Daniela C.
Published: March 2011

A striking difference between xenarthrans and other mammals is the complete loss of tooth enamel in all members but the earliest armadillos. However, sloth and armadillo teeth show structured wear facets, which in all other mammals are formed by tooth enamel. How is that possible? Here, I report about an analysis of fossil and recent xenarthran dental hard tissue microstructure. It shows that osteodentine is not exclusive to fossil Cingulata, but also occurs in some recent taxa. Furthermore, I found profound modifications of orthodentine architecture in comparison to other mammals. Remarkable features are (a) a larger proportion of the highly mineralized, collagen‐free peritubular dentine, and (b) a modified architecture of the odontoblastic process with frequent interconnections between the extensions and unusually intensive branching of the extensions forming a complex meshwork, penetrating the intertubular dentine matrix. The orthodentine microstructural build‐up is unique in Folivora and Cingulata. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.
Dissection of dispersed off‐resonant femtosecond degenerate four‐wave mixing of O2
Authors: Knopp G. , Radi P. P. , Sych Y. , Gerber T.
Published: March 2011

Simultaneous time and frequency detection in off‐resonant femtosecond degenerate four‐wave mixing (fs‐DFWM) experiments displays spectral features that are covered in standard, nondispersed, frequency‐integrated measurements. The application of laser fields with finite bandwidths, narrower than or comparable to the rotational Raman bands, affects the observed coherent signals. Information available from such experiments is split between the time and frequency domains and an improved measurement necessitates a combined detection. Rotational recurrences of oxygen (O2), measured by dispersed fs‐DFWM at room temperature, exhibit spectral characteristics, using 800‐nm laser pulses with ∼100 fs duration. Analysis of the detected signals in both dimensions incorporating temporal and spectral trends can assist in the extraction and interpretation of chemicophysical quantities from the experiment. The dispersed recurrent signals are in accordance with simulations. Copyright © 2011 John Wiley & Sons, Ltd.
Phase‐locking of two independent degenerate coherent anti‐Stokes Raman scattering processes: concept, proposed all‐optical implementation, and potential applications
Authors: Zhang Qun
Published: March 2011

A novel approach toward phase‐locking of two independently produced yet energetically degenerate coherent anti‐Stokes Raman scattering (CARS) processes is put forward. The proposed all‐optical implementation involves a modified Mach–Zehnder interferometer, which is utilized to transfer phase coherence from three totally uncorrelated laser beams into two degenerate CARS beams that are produced in two distinct Raman active samples. Such a CARS interferometer based on coherent phase transport allows explicit measurement and control of phase differences between the two phase‐locked degenerate CARS processes, and hence may find applications in pertinent research fields such as CARS spectroscopy (tomography) as well as quantum information processing and transfer. Copyright © 2011 John Wiley & Sons, Ltd.
Low‐wavelength emission of Nd‐doped lasers
Authors: Balembois F. , Castaing M. , Hérault E. , Georges P.
Published: March 2011

This paper gives an overview of the results obtained with diode‐pumped Neodymium‐doped crystals operating below 900 nm. Operation at such low wavelengths requires considering the strong thermal population of the lower level of the laser transition. Based on a theoretical study and simulations, the paper presents the challenges related to the design of these three‐level lasers. Experimental results are given with Nd:YAG and Nd:vanadate crystals. It is explained how to deal with the line competition with emission at 946 nm or 912 nm. Finally, intracavity second‐harmonic generation is presented. The output powers reach a few hundred mW at wavelengths below 450 nm. Hence, the paper demonstrates the potential of Nd‐doped diode‐pumped solid‐state lasers for applications in the blue range, in replacement of gas lasers such as helium‐cadmium lasers.
Film‐forming properties of castor oil–polyol ester blends in elastohydrodynamic conditions
Authors: Bantchev Grigor B. , Biresaw Girma
Published: March 2011

The viscosity and elastohydrodynamic (EHD) film thickness properties of binary blends of castor oil with polyol esters were determined experimentally. Predicted blend viscosities were calculated from the viscosities of the pure blend components. Measured viscosity values were closer to the values predicted using the Lederer model than the Arrhenius model. EHD film thickness data were mostly in agreement with the predictions of the Hamrock–Dowson model. Observed deviations of EHD film thickness were attributed to boundary film formation and thermal effects. Calculated effective pressure–viscosity coefficients, α, displayed a complex relationship with blend viscosity. At 40°C, the addition of 10% polyol esters resulted in a 12–17% drop in α of castor oil. Higher concentrations of polyol esters resulted in an increase of α. At 70 and 100°C, α displayed an almost linear dependence on blend composition. Copyright © 2011 John Wiley & Sons, Ltd.
Association of Hepatic Artery Stenosis and Biliary Strictures in Liver Transplant Recipients
Authors: Dacha Sunil , Barad Ashis , Martin John , Levitsky Josh
Published: March 2011

Biliary complications are important causes of morbidity and graft failure in patients after orthotopic liver transplantation. Nonanastomotic biliary strictures (NAS) are frequently the most challenging biliary complications. Hepatic artery stenosis (HAS) as a cause of biliary strictures has not been studied well systematically. We performed a retrospective cohort study of patients who underwent liver transplantation at our institution between 1995 and 2007 to determine the incidence of biliary strictures (nonanastomotic and anastomotic) with HAS. Forty patients were identified, and they were compared with 62 matched non-HAS controls. Overall, NAS and biliary anastomotic strictures were seen more frequently in patients with HAS (24/40 or 60%) versus control patients (6/62 or 9.67%, P < 0.000001). Cholangiographic evidence of NAS was seen in 10 of 40 study patients (25%) and in 1 of 62 control patients (2%, P < 0.0001), whereas evidence of biliary anastomotic strictures was seen in 14 of 40 study patients (35%) and in 5 of 62 control patients (8%, P = 0.0006). The cold ischemia time was also found to be associated with the presence of NAS in patients with HAS (P = 0.024). Patients with biliary strictures were generally managed successfully with endoscopic retrograde cholangiopancreatography balloon dilation/stenting, except for 4 NAS patients who had significant morbidity and mortality. In conclusion, the development of HAS, particularly with a prolonged cold ischemia time, may increase the NAS risk after liver transplantation. HAS is also associated with the development of biliary anastomotic strictures. Prospective studies of frequent arterial monitoring for the early detection of HAS and interventions to prevent biliary complications are needed. Liver Transpl 17:849-854, 2011. © 2011 AASLD.
Should Possible Recurrence of Disease Contraindicate Liver Transplantation in Patients with End-Stage Alveolar Echinococcosis? a 20-Year Follow-Up Study
Authors: Bresson-Hadni Solange , Blagosklonov Oleg , Knapp Jenny , Grenouillet Frédéric , Sako Yasuhito , Delabrousse Eric , Brientini Marie-Pascale , Richou Carine , Minello Anne , Antonino Anca-Teodora , Gillet Michel , Ito Akira , Mantion Georges André , Vuitton Dominique Angèle
Published: March 2011

Liver transplantation (LT) is currently contraindicated in patients with residual or metastatic alveolar echinococcosis (AE) lesions. We evaluated the long-term course of such patients who underwent LT and were subsequently treated with benzimidazoles. Clinical, imaging, serological, and therapeutic data were collected from 5 patients with residual/recurrent AE lesions who survived for more than 15 years. Since 2004, [18F]-2-fluoro-2-deoxyglucose (FDG)–positron emission tomography (PET) images were available, and the levels of serum antibodies (Abs) against Echinococcus multilocularis–recombinant antigens were evaluated. Median survival time after LT was 21 years. These patients were from a prospective cohort of 23 patients with AE who underwent LT: 5 of 8 patients with residual/recurrent AE and 4 of 9 patients without residual/recurrent AE were alive in September 2009. High doses of immunosuppressive drugs, the late introduction of therapy with benzimidazoles, its withdrawal due to side effects, and nonadherence to this therapy adversely affected the prognosis. Anti-Em2plus and anti-rEm18 Ab levels and standard FDG-PET enabled the efficacy of therapy on the growth of EA lesions to be assessed. However, meaningful variations in Ab levels were observed below diagnostic cutoff values; and in monitoring AE lesions, images of FDG uptake taken 3 hours after its injection were more sensitive than images obtained 1 hour after its injection. In conclusion, benzimidazoles can control residual/recurrent AE lesions after LT. Using anti-rEm18 or anti-Em2plus Ab levels and the delayed acquisition of FDG-PET images can improve the functional assessment of disease activity. The potential recurrence of disease, especially in patients with residual or metastatic AE lesions, should not be regarded as a contraindication to LT when AE is considered to be lethal in the short term. Liver Transpl 17:855-865, 2011. © 2011 AASLD.
Hydrodynamic Activation of the Batch‐Polymerization of Methyl methacrylate in a Taylor‐Couette Reactor
Authors: Liu Zhen , Kádár Roland , Kind Matthias
Published: March 2011

Summary:In this work, the free radical batch polymerization of methyl methacrylate (MMA) premixed with xylene as a solvent, in the presence of an initiator, 2,2‐azoisobutyronitrile (AIBN), in the Taylor‐Couette reactor was studied. We observed an unexpected influence of hydrodynamic process parameters, i.e. angular velocity ω, on the polymer conversion, molecular weight and viscosity of the produced polymer. The polymerization process seems to be activated by hydrodynamic process parameters. Hydrodynamic activation is a promoting effect of process parameters on polymer product properties. The hydrodynamic activation is found to depend on the reaction time and the angular velocity of the inner cylinder. In addition, our results highlight both the reaction kinetics and the hydrodynamics during the polymerization. The conversion exhibits a significant difference between tests with and without the angular velocity of the inner cylinder. The conversion and the molecular weight strongly increase with the increase of the angular velocity of the inner cylinder, whereas the viscosity is less strongly dependent. There is more increase with decreasing solvent concentration. The radial Reynolds number decreases with increasing conversion. The polymerization is faster with a low solvent concentration, and the molecular weight is higher compared to the case of high solvent concentration.
Electrical, Film and Surface Properties of Water‐Based Latexes Prepared by Semicontinuous Emulsion Polymerization
Authors: Kahraman Ayça , Sarac Ayfer
Published: March 2011

Summary: In this study, the results obtained with latexes prepared by semicontinuous emulsion polymerization with conventional anionic and nonionic emulsifiers and their different mixtures were presented. For this study, vinyl acetate‐butyl acrylate latexes with a conventional anionic emulsifier (sodium lauril ether sulfate) and a nonionic emulsifier (30 mole nonyl phenol ethoxylate), of which films can be easily cast, were used. The latex properties in terms of mechanical stability, film‐water absorption, and film‐emulsifier exudation, and surface and electrical properties were assessed and compared.
Computational Analysis of Mixing and Scale‐Up in Emulsion Polymerization Reactors
Authors: Pohn Jordan , Heniche Mourad , Fradette Louis , Cunningham Michael , McKenna Timothy
Published: March 2011

Summary: A hybrid multi‐zonal/computational fluid dynamics (CFD) framework is currently being developed to aid in the scale‐up of high solid content latex production and processing. Poly3D, a commercial laminar CFD code tailored to modelling the mixing of non‐Newtonian fluids, has been coupled to a population balance model via a customized interface. CFD is used to generate flow fields inside a series of reactors; this information is then transferred to a multi‐zone population balance model to assess the impact of non‐homogenous mixing on the evolution of the latex particle size distribution (PSD) when concentrated latex suspension is altered via the addition of a coagulant. The rheological properties of high solid content latexes are sensitive to changes in the PSD, so the flow field is periodically updated if significant changes in the rheological properties of the latex are detected in any of the zones. The details of the models comprising the framework are presented and the utility of the framework is demonstrated.
A Density Functional Theory Study of Poly (vinyl chloride) (PVC) Free Radical Polymerization
Authors: Cuccato Danilo , Dossi Marco , Moscatelli Davide , Storti Giuseppe
Published: March 2011

Summary: Quantum chemistry was applied to the free radical polymerization of Vinyl Chloride with the aim of elucidating the reaction kinetics and especially the formation of structural defects and low molecular weight polymer. The radical reactions were studied using the Density Functional Theory. All calculations were performed with B3LYP functionals and in particular the 6‐31G(d,p) basis set was selected to evaluate the exchange and correlation energies. The computational method was first validated by predicting the rate constant of the propagation step and comparing the calculated values to experimental ones. Then intramolecular chain transfer, β‐scission and branching reactions were also investigated, due to their direct connection with the production of defects in the growing chains. A comparison of the evaluated kinetic constants of such secondary reactions with other computational evaluations and experimental data was finally made.
Microwave Effects Due to Anionic or Cationic Initiators in Emulsion Polymerization Reactions
Authors: Costa Cristiane , Santos Verusca H. S. , Sayer Claudia , Araujo Pedro H. H. , Santos Alexandre F. , Fortuny Montserrat
Published: March 2011

Summary: Emulsion polymerization reactions were performed under microwave irradiation and conventional heating using anionic or cationic initiators and surfactants. Microwave irradiation promoted higher reaction rates for both initiators and surfactants, in comparison with the conventional heating. The effect of high power microwave irradiation was studied using a method of cycles of heating and cooling, where rapid polymerization reactions were obtained. In the reactions with anionic initiator and surfactant, a decrease in the particle diameters was observed with microwave heating, and even smaller particles were obtained using high power microwave irradiation. Moreover, the decrease in the particle size was acompanied by an increase in the polymer molecular weight. On the other hand, these effects were not observed for reactions with cationic initiator and surfactant.
Modelling of the High‐Impact Polystyrene Morphogenesis
Authors: Vonka Michal , Šeda Libor , Kosek Juraj
Published: March 2011

Summary: High‐impact polystyrene (HIPS) is a hetero‐phase polymer with the so‐called salami morphology. Salami morphology is formed by a continuous PS phase containing micron‐sized PB domains. PB domains contain submicron‐sized irregular PS occlusions. In our modeling work we addressed several weak points of Cahn‐Hilliard model of HIPS salami morphology evolution. The weakest point of Cahn‐Hilliard model is the inherently present Ostwald ripening destabilizing or competing with graft‐stabilized domains. Two mechanism of formation of HIPS morphology are supported by the model: (i) encapsulation of graft‐stabilized PS‐rich domains in PB particles, and (ii) polymerization of styrene dissolved in PB‐rich phase and subsequent phase separation leading to PS occlusions in PB domains.
Data Reconciliation and Control in Styrene‐Butadiene Emulsion Polymerizations
Authors: Souza Paula Naomi , Soares Matheus , Amaral Marcelo M. , Lima Enrique Luis , Pinto José Carlos
Published: March 2011

Summary: A nonlinear model‐based predictive control (NLMPC) method was developed using a First Principles model of an emulsion copolymerization of carboxylated styrene butadiene rubber (XSBR). Copolymer composition, conversion and average molecular weights of the copolymer were chosen as the controlled variables due to their influence on the final product properties and quality. These properties, however, are rarely measured in‐line due to the operational difficulties associated with their measurement. For this reason a soft‐sensor using reaction calorimetry techniques was developed and used to infer reaction conditions, rates, species concentrations and polymer properties in a industrial scale emulsion polymerization reactor.
Design and Simulation of a New Reactor for the Production of High‐Viscosity Polymer Melts
Authors: Rieckmann Thomas , Frei Fabian , Völker Susanne
Published: March 2011

Summary: Innovative reactor internals consisting of a number of vertically stacked perforated plates have been proposed to increase mass transfer rates of volatiles from highly viscous polymer melts. A mathematical model comprising mass and enthalpy balances for the polycondensation of polyamide 6 has been used to evaluate the new reactor design. According to the simulation, the alternating arrangement of devolatilization and residence zones leads to an effective removal of reaction water from the polymer melt. Compared to the VK‐tube reactor, which is most commonly used to produce high quality PA‐6, the new reactor design produces high quality polymer with a high degree of polymerization within a considerably shorter residence time. The application of the proposed reactor internals is not limited to PA‐6 production, since the removal of volatiles is of the same major importance during all reversible polycondensation reactions, e.g. the production of PET.
A Detailed Polymerization Model for Cerenol® Polyols
Authors: Mueller Philipp A. , Murphy Edward R. , Rajagopalan Bhuma , Congalidis John P. , Minter Aaron R.
Published: March 2011

Summary: A mathematical model of the acid catalyzed 1,3‐propanediol polymerization has been developed. Two catalysts investigated include sulfuric acid and superacid (tetrafluoroethane sulfonic acid or triflic acid). Based on a detailed reaction mechanism, population and mass balance equations have been derived for small molecules as well as for polymeric species of numerous chain distributions, which are distinguishable in terms of protonation state and end group functionality. Due to the interaction of the sulfuric acid catalyst with the polymer ends, a novel, dual index polymer chain distribution was derived and implemented.

The model has been validated with various sets of experimental data obtained in a lab‐scale reactor setup. Dynamic model outputs such as monomer concentration, molecular weight averages, unsaturated and sulfate end groups, water evaporation rate and sulfate middle groups have been compared with experimental data of sulfuric and super acid catalyzed polymerization runs. Very good agreement between model predictions and experimental data has been obtained for both catalyst systems over an extended range of conditions using the same set of model parameter values. It is worth noting that the model is also capable of predicting polymerization equilibrium.
Safety and Quality Aspects of Acrylic Monomers
Authors: Hartwig Ali , Brand Raphael H. , Pfeifer Christian , Dürr Nadine , Drochner Alfons , Vogel Herbert
Published: March 2011

Summary: Acrylic monomers are important intermediates for the chemical industry. Especially acrylic acid (AA) is the basis for various reactions, such as polymerizations and esterifications and is, therefore, responsible for high product diversity. Spontaneous polymerization is a safety problem during the transportation and storage of acrylic monomers. In the production process, polymerization leads to blockages in the apparatus. For the prevention of these issues, special stabilizer systems are used such as hydroquinone monomethyl ether (MeHQ)/oxygen and phenothiazine (PTZ). The reactions of these stabilizer systems are not well understood at the moment. Therefore a lot of expertise and experience are necessary to guarantee safe handling. In this paper some methods for the investigation of stability related reaction kinetics are presented. A better comprehension of the mechanism of the polymerization inhibition is generated by the kinetic simulation with these data.
Polymerization Kinetics of Water‐Soluble N‐Vinyl Monomers in Aqueous and Organic Solution
Authors: Santanakrishnan Sandhya , Hutchinson Robin A. , Učňová Lucia , Stach Marek , Lacík Igor , Buback Michael
Published: March 2011

Summary: Free‐radical batch polymerization (FRP) of N‐vinyl pyrrolidone (NVP) and N‐vinyl formamide (NVF) monomers in aqueous solution as well as NVP polymerization in organic (n‐butanol) solution has been studied. The differences found in rate of monomer conversion with monomer and solvent choice correlates well with the differences in values of the propagation rate coefficients (kp) and their variation with monomer concentration measured in independent pulsed‐laser polymerization studies, a result demonstrating that a generalized understanding of water‐soluble vinyl monomers can be obtained once their kp differences have been accounted for. A reasonable representation of polymer molecular mass averages and the complete molecular mass distributions for the three systems was obtained by assuming that the rate coefficient for transfer to monomer, polymer, and organic solvent also vary as a function of monomer concentration.
Molecular Versus Conventional Kinetics of Emulsion Polymerization
Authors: Tauer Klaus , Hernandez Hugo , Weber Nancy , Roohi Farnoosh
Published: March 2011

Summary: Experimental data are discussed challenging the deterministic kinetics of emulsion polymerization. Examples are given for the overall rate of polymerization, in‐situ stabilizer formation, and swelling of latex particles. Improving the deterministic view on emulsion polymerization kinetics requires the consideration of results of molecular modelling and the application of multiscale integration techniques.
Order and Phase Behavior of a Cylinder Forming Diblock Copolymers and Nano‐Particles Mixture in Confinement: A Molecular Dynamics Study
Authors: Shagolsem Lenin S. , Sommer Jens‐Uwe
Published: March 2011

We study a coarse grained model of cylinder forming diblock copolymers and nano‐particles (NPs) mixture confined between Lennard–Jones hard walls. Two models for non‐selective interactions between monomers and NPs are applied. In the case of purely repulsive interactions between NPs and monomers (athermal case) strong segregation of NPs at the film surfaces and the formation of droplets of particles inside the copolymer film can be observed. For weakly attractive interactions between NPs and monomers (thermal case) formation of droplets of particles disappears and segregation on the film surfaces depend on temperature. The uptake of NPs by the copolymer film in the thermal case displays a non‐monotonic dependence on temperature which can be qualitatively explained by a mean‐field model. In both cases of non‐selective interactions NPs are preferentially localized at the interface between the microphase domains.

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Targeting PKC‐β II and PKB Connection: Design of Dual Inhibitors
Authors: Jain Kapil , Ajay Dara , Sobhia M. Elizabeth
Published: March 2011

Protein kinase C (PKC) has been the center of many cell signaling pathways. PKC isoforms, specifically PKC‐β II is linked to both diabetic complications as well as in promotion of angiogenesis and regulation of cancers. PKC‐β II activates the PKB/Akt pathway. Enzastaurin, a selective PKC‐β II inhibitor has been found to inhibit PKB/Akt by suppressing the regulation of various cancerous pathways. In the present work, we carried out an in depth study on the binding mode of inhibitors of PKC‐β II, enzastaurin and ruboxistaurin with the active site residues of PKB and PKC‐β II. A ligand based approach has been further used to determine the pharmacophoric features and spatial arrangement of molecules, having common properties necessary for appropriate binding to the active site of both targets. Virtual screening of the respective pharmacophores of both proteins led to identification of hits which may be useful for treatment of diabetic complications and cancer. The study has highlighted important features that may be considered in the future for designing novel inhibitors.
Prilocaine–cyclodextrin–liposome: effect of pH variations on the encapsulation and topology of a ternary complex using 1H NMR
Authors: Cabeça Luís Fernando , Figueiredo Isis Martins , Paula Eneida de , Marsaioli Anita Jocelyne
Published: March 2011

A better comprehension of the prilocaine (PLC)–β‐cyclodextrin (β‐CD) complex liberation to membranes was provided by studying the architectural supramolecular arrangements of PLC, β‐CD and egg phosphatidylcholine (EPC) liposomes, a membrane model. The topologies and possible interactions of mixtures of PLC, β‐CD and EPC liposomes were investigated by nuclear magnetic resonances combining experimental 1H‐NMR (1D ROESY, STD and DOSY) at different pHs. The results indicate that in the mixture PLC/β‐CD/EPC at pH 10 the PLC molecules are almost totally embedded into the liposomes and little interaction was observed between PLC and β‐CD. However, at pH 5.5 not only was PLC imbedded in the EPC bilayer, but PLC was also interacting with β‐CD. These results were rationalized as a spontaneous PLC release from β‐CD to liposomes vesicles, whereas the PLC/EPC complex formation was higher at pH 10 than pH 5.5. Copyright © 2011 John Wiley & Sons, Ltd.
NMR assignment in regioisomeric hydroquinones
Authors: Dobado Jose A. , Gómez‐Tamayo José C. , Calvo‐Flores Francisco G. , Martínez‐García Henar , Cardona Wilson , Weiss‐López Boris , Ramírez‐Rodríguez Oney , Pessoa‐Mahana Hernán , Araya‐Maturana Ramiro
Published: March 2011

A set of regioisomeric pairs of tricyclic hydroquinones, analogues of antitumor 9,10‐dihydroxy‐4,4‐dimethyl‐5,8‐dihydroanthracen‐1(4H)‐one (1) and other derivatives, were synthesized and their regiochemistry and NMR spectra assigned by using 1H‐detected one‐bond (CH) HMQC and long‐range CH HMBC, in good agreement with theoretical O3LYP/Alhrichs‐pVTZ calculations. The 5‐hydroxymethyl derivatives (11, 15, 19) showed a 3JH, H coupling constant of methylene protons evidencing the presence of a seven‐membered intramolecular hydrogen bonded ring, not observed for the 8‐hydroxymethyl isomers. Copyright © 2011 John Wiley & Sons, Ltd.
Steroids and an oxylipin from an algicolous isolate of Aspergillus flavus
Authors: Qiao Ming‐Feng , Ji Nai‐Yun , Miao Feng‐Ping , Yin Xiu‐Li
Published: March 2011

A new oxylipin, (8E,12Z)‐10,11‐dihydroxyoctadeca‐8,12‐dienoic acid (1), a new steroid, 3β,4α‐dihydroxy‐26‐methoxyergosta‐7,24(28)‐dien‐6‐one (2), and four known steroids, episterol (3), (22E,24R)‐ergosta‐7,22‐dien‐3β,5α,6α‐triol (4), (22E,24R)‐ergosta‐5,22‐dien‐3β‐ol (5), and (22E,24R)‐ergosta‐4,6,8(14),22‐tetraen‐3‐one (6), were isolated from the cultures of Aspergillus flavus, an endophytic fungus isolated from the marine red alga Corallina officinalis. Their structures and relative stereochemistry were elucidated by 1D, 2D NMR and mass spectroscopic techniques. 1 and 2 exhibited low activity to inhibit acetylcholinesterase and no activity against plant pathogenic fungi Colletotrichum lagenarium and Fusarium oxysporum. Copyright © 2011 John Wiley & Sons, Ltd.
Saturation‐dependent nuclear magnetic resonance relaxation of fluids confined inside porous media with micrometer‐sized pores
Authors: Simina Marius , Nechifor Ruben , Ardelean Ioan
Published: March 2011

In the present study, we investigate the relationship between the relaxation rate and the filling factor in partially saturated porous media. The filling fluids are polar (water, acetone) and nonpolar (cyclohexane, hexane). The porous sample is a silica glass (Vitrapor#5) with the nominal mean pore size of d = 1 µm ( ± 0.6 µm). All nuclear magnetic resonance relaxation experiments are performed at 20 °C using a NMR instrument operable at 20 MHz proton resonance frequency. The experimental results are compared with a two‐phase exchange model providing us information on the strength of surface relaxation and fluid distribution inside pores. These results will affect the NMR estimations about fluid content of porous media. Copyright © 2011 John Wiley & Sons, Ltd.
Complete NMR data of methoxylated cis‐ and trans‐stilbenes as well as 1,2‐diphenylethanes
Authors: Jo Geunhyeong , Hyun Jiye , Hwang Doseok , Lee Young Han , Koh Dongsoo , Lim Yoongho
Published: March 2011

Resveratrol is a polyphenol isolated from many natural sources including grapes, mulberries, eucalyptus, spruce, lilies, and peanuts. The hydroxyl groups in polyphenols can be substituted with various functional groups, allowing production of multiple derivatives. NMR spectroscopy is used to identify new derivatives. Since the complete NMR data of the known derivatives can be useful for identification of the newly isolated derivatives, here, we report the synthesis of 14 methoxylated stilbenes and four 1,2‐diphenylethanes and their NMR data. Copyright © 2011 John Wiley & Sons, Ltd.
Conformational analysis and diastereotopic assignments in the series of selenium‐containing heterocycles by means of 77Se‐1H spin‐spin coupling constants: a combined theoretical and experimental study
Authors: Rusakov Yury Yu. , Krivdin Leonid B. , Potapov Vladimir A. , Penzik Maxim V. , Amosova Svetlana V.
Published: March 2011

A combined theoretical and experimental study on the stereochemical behavior of 77Se‐1H spin‐spin coupling constants has been performed at the second‐order polarization propagator approach level together with heteronuclear multiple‐bond correlation technique in the series of selenium‐containing four‐, five‐ and six‐membered heterocycles including the derivatives of thiaselenetane, selenasilole, thiaselenole, thiaselenolane and dihydrothiaselenine. Geminal and vicinal 77Se‐1H spin‐spin couplings were shown to have the pronounced stereochemical dependences in respect with the topology of the coupling pathway, internal rotation of the side‐chain substituents and ring inversion providing a straightforward tool for the conformational analysis and diastereotopic assignments in the chiral organoselenium compounds. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of pharmaceutical counselling on antimicrobial use in surgical wards: intervention study with historical control group,
Authors: Grill Eva , Weber Alexandra , Lohmann Stefanie , Vetter‐Kerkhoff Cornelia , Strobl Ralf , Jauch Karl‐Walter
Published: March 2011

Purpose

The objective of this study was to assess the impact of pharmaceutical consulting on the quality of antimicrobial use in a surgical hospital department in a prospective controlled intervention study.

Methods

Patients receiving pharmaceutical intervention (intervention group, IG, n = 317) were compared with a historical control group (control group, CG, n = 321). During the control period, antimicrobial use was monitored without intervention. During the subsequent intervention period, a clinical pharmacist reviewed the prescriptions and gave advice on medication.

Results

Intervention reduced the length of antimicrobial courses (IG = 10 days, CG = 11 days, incidence rate ratio for i.v. versus o.p. = 0.88, 95% confidence interval 0.84 to 0.93) and shortened i.v. administration (IG = 8 days, CG = 10 days, hazard rate = 1.76 in favour of switch from i.v. to p.o., 95% confidence interval 1.23 to 2.52). Intervention also helped to avoid useless combination therapy and reduced total costs for antimicrobials.

Conclusions

A clinical pharmacist who reviews prescriptions can promote an increase in efficiency, for example, by shortening the course of treatment. Counselling by ward‐based clinical pharmacists was shown to be effective to streamline antimicrobial therapy in surgical units and to increase drug safety. Copyright © 2011 John Wiley & Sons, Ltd.
On the testing of large PV arrays
Authors: Martínez‐Moreno F. , Lorenzo E. , Muñoz J. , Moretón R.
Published: March 2011

This paper reports on the IES‐UPM experience from 2006 to 2010 in the field of the characterization of PV arrays of commercial large PV plants installed in Spain within the framework of the profitable economic scenarios associated to feed‐in tariff laws. This experience has extended to 200 MW and has provided valuable lessons to minimize uncertainty, which plays a key role in quality assurance procedures. The paper deals not only with classic I–V measurements but also with watt‐metering‐based procedures. Particular attention is paid to the selection of irradiance and cell temperature sensors. Copyright © 2011 John Wiley & Sons, Ltd.
Proteome profiling reveals potential toxicity and detoxification pathways following exposure of BEAS‐2B cells to engineered nanoparticle titanium dioxide
Authors: Ge Yue , Bruno Maribel , Wallace Kathleen , Winnik Witold , Prasad Raju Y.
Published: March 2011

Oxidative stress is known to play important roles in engineered nanomaterial‐induced cellular toxicity. However, the proteins and signaling pathways associated with the engineered nanomaterial‐mediated oxidative stress and toxicity are largely unknown. To identify these toxicity pathways and networks that are associated with exposure to engineered nanomaterials, an integrated proteomic study was conducted using human bronchial epithelial cells, BEAS‐2B and nanoscale titanium dioxide. Utilizing 2‐DE and MS, we identified 46 proteins that were altered at protein expression levels. The protein changes detected by 2‐DE/MS were verified by functional protein assays. These identified proteins include some key proteins involved in cellular stress response, metabolism, adhesion, cytoskeletal dynamics, cell growth, cell death, and cell signaling. The differentially expressed proteins were mapped using Ingenuity Pathway Analyses™ canonical pathways and Ingenuity Pathway Analyses tox lists to create protein‐interacting networks and proteomic pathways. Twenty protein canonical pathways and tox lists were generated, and these pathways were compared to signaling pathways generated from genomic analyses of BEAS‐2B cells treated with titanium dioxide. There was a significant overlap in the specific pathways and lists generated from the proteomic and the genomic data. In addition, we also analyzed the phosphorylation profiles of protein kinases in titanium dioxide‐treated BEAS‐2B cells for a better understanding of upstream signaling pathways in response to the titanium dioxide treatment and the induced oxidative stress. In summary, the present study provides the first protein‐interacting network maps and novel insights into the biological responses and potential toxicity and detoxification pathways of titanium dioxide.
Small colony variants of Staphylococcus aureus reveal distinct protein profiles
Authors: Kriegeskorte André , König Simone , Sander Gunnar , Pirkl Alexander , Mahabir Esther , Proctor Richard A. , von Eiff Christof , Peters Georg , Becker Karsten
Published: March 2011

Small‐colony variants (SCVs) of Staphylococcus aureus represent a slow‐growing subpopulation causing chronic and relapsing infections due to their physiological adaptation on an intracellular lifestyle. In this first proteomic study on physiological changes associated with a natural, clinically derived SCV, its proteomic profile was investigated in comparison to corresponding isogenic strains displaying normal (clinical wild‐type strain, complemented hemB mutant and spontaneous revertant of the clinical SCV) and SCV phenotypes (hemB mutant and gentamicin‐induced SCV). Applying an ultra‐high resolution chromatography and high mass accuracy MSE‐based label‐free relative and absolute protein quantification approach, the whole cytoplasmic proteome of this strain sextet was investigated in a growth phase‐controlled manner covering early‐exponential, late‐exponential and stationary phases. Of 1019 cytoplasmic proteins identified, 154 were found to be differently regulated between strains. All SCV phenotypes showed down‐regulation of the tricarboxylic acid (TCA) cycle‐related proteins and of a protein cluster involved in purine/pyrimidine and folate metabolism. In contrast to hemB mutant and gentamicin‐induced SCVs, the clinically derived SCVs showed no prominent up‐regulation of glycolytic proteins. The spontaneous switch into the normal phenotype resulted in up‐regulation of TCA cycle‐related parts, while oxidative stress‐related proteins were down‐regulated. However, the natural revertant from the clinical SCV retained also dominant protein features of the clinical SCV phenotype. In conclusion, physiological changes between normal and SCV S. aureus phenotypes are more complex than reflected by defined electron transport chain‐interrupting mutants and their complemented counterparts.
Synthesis of novel hyperbranched polymer through cationic ring‐opening multibranching polymerization of 2‐hydroxymethyloxetane
Authors: Satoh Toshifumi , Tamaki Masaki , Taguchi Tsukasa , Misaka Hideki , Hoai Nguyen To , Sakai Ryosuke , Kakuchi Toyoji
Published: March 2011

The cationic ring‐opening multibranching polymerization of 2‐hydroxymethyloxetane (1) as a novel latent AB2‐type monomer was carried out using trifluoromethane sulfonic acid or trifluoroboron diethyl etherate by a slow‐monomer‐addition (SMA) method. The polymer yield of poly‐1 ranged from ca. 58–88%, which increase with the increasing monomer addition time on the SMA method. The absolute molecular weights (Mw,MALLS) and the polydispersities of poly‐1 were in the range of 8,000–43,500 and 1.45–4.53, respectively, which also increased with the increasing monomer addition time. The Mark‐Houwink‐Sakurada exponents α in 0.2 M NaNO3 aq. were determined to be 0.02–0.25 for poly‐1, indicating that poly‐1 has compact forms in the solution because of the highly branched structure. The degree of the branching value of poly‐1, which was calculated by Frey's equation, ranged from ca. 0.50 to 0.58, which increased with the increasing monomer addition time. The steady shear flow of poly‐1 in aqueous solution exhibited a Newtonian behavior with steady shear viscosities independent of the shear rate. The results of the MALLS, NMR, and viscosity measurements indicated that poly‐1 is composed of a highly branched structure, i.e., the hyperbranched poly (2‐hydroxymethyloxetane). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
A versatile single‐electron‐transfer mediated living radical polymerization route to galactoglucomannan graft‐copolymers with tunable hydrophilicity
Authors: Voepel Jens , Edlund Ulrica , Albertsson Ann‐Christine
Published: March 2011

Cu(0) mediated living radical polymerization was successfully applied to synthesize graft‐copolymers from the hemicellulose acetylated galactoglucomannan. Functionalizing the polysaccharide backbone with α‐bromo isobutyric acid gave rise to a macroinitiator for single‐electron‐transfer mediated living radical polymerization (SET‐LRP). This macroinitiator with a degree of substitution of 0.15 or 0.20 was used in the graft‐SET‐LRP of methyl methacrylate in dimethyl sulfoxide as well as N‐isopropyl acrylamide and acrylamide in water. Kinetic analyses confirm conversions of up to 73% and a controlled behavior of the SET‐LRP process providing high molecular weight hemicellulose‐based hybrid copolymers with a brush‐like architecture. Derived graft‐copolymers varied significantly in solubility properties, ranging from hydrophobic via temperature responsive water‐solubility to water‐soluble. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Effect of night symptoms and disease severity on subjective sleep quality in children with non‐cystic‐fibrosis bronchiectasis
Authors: Erdem Ela , Ersu Refika , Karadag Bulent , Karakoc Fazilet , Gokdemir Yasemin , Ay Pinar , Akpinar Ihsan Nuri , Dagli Elif
Published: April 2011

Background

Night‐time symptoms and hypoxemia during sleep may affect sleep quality in children with chronic lung disease such as bronchiectasis. Poor sleep quality may impair growth, learning, and emotional development of children. Our aim was to assess the sleep quality and associated factors in children with non‐cystic fibrosis bronchiectasis.

Methods

Fifty‐four patients with bronchiectasis and age‐matched controls were included to the study. Pittsburgh Sleep Quality Index (PSQI) and Pediatric Sleep Questionnaire (PSQ) were used to evaluate sleep quality and presence of sleep disordered breathing. A global sum of 5 or more according to PSQI indicated a poor sleep quality. A cut‐off value of 0.33 in PSQ was used to identify pediatric sleep disordered breathing. Association between PSQI, pulmonary function tests, symptoms and HRCT scores were evaluated.

Results

Thirty‐seven percent of patients with bronchiectasis and 17% of patients in the control group had poor sleep quality (P < 0.05). Patients with sputum and wheezing had poorer sleep scores (P = 0.003 and P = 0.005). The association of wheezing and breathlessness during night time with sleep quality tended to be significant (P = 0.05). Twenty‐two percent of patients with bronchiectasis and 9% of controls had sleep disordered breathing (P = 0.003). Bronchiectasis patients who snored had poorer sleep quality (P < 0.001) and patients with wheezing had significantly higher rate of snoring (P = 0.04). Children with worse HRCT scores also had worse sleep quality (r = 0.28, P = 0.04).

Conclusions

Patients with bronchiectasis have disturbed sleep associated with severity of disease. Night symptoms increase the risk of poor sleep quality. Sleep disordered breathing and sleep quality should be assessed in these patients. Pediatr. Pulmonol. 2011; 46:919–926. © 2011 Wiley‐Liss, Inc.
Urine proteomics in kidney and urogenital diseases: Moving towards clinical applications
Authors: Zürbig Petra , Dihazi Hassan , Metzger Jochen , Thongboonkerd Visith , Vlahou Antonia
Published: March 2011

To date, multiple biomarker discovery studies in urine have been conducted. Nevertheless, the rate of progression of these biomarkers to qualification and even more clinical application is extremely low. The scope of this article is to provide an overview of main clinically relevant proteomic findings from urine focusing on kidney diseases, bladder and prostate cancers. In addition, approaches for promoting the use of urine in clinical proteomics including potential means to facilitate the validation of existing promising findings (biomarker candidates identified from previous studies) and to increase the chances for success for the identification of new biomarkers are discussed.
Infrared spectroscopic growth studies of an organic semiconductor
Authors: Glaser Tobias , Binder Martin , Lennartz Christian , Schildknecht Christian , Pucci Annemarie
Published: March 2011

We show an example for sensitive in situ monitoring of organic film growth by means of infrared spectroscopy. The phosphorescent emitter material used in this study was developed for the application in organic light emitting diodes. During thermal evaporation under ultra‐high vacuum conditions its vibrational spectrum is monitored and compared to spectra of pristine powder and calculated ones. This comparison proves that the molecules were not destroyed during evaporation and that their mutual interaction in the condensed layer gives rise to only marginal spectral modifications, which indicates the formation of a van der Waals‐like solid where the molecular electronic properties are preserved. The development of infrared spectral features with film thickness made obvious that no phase changes occurred during deposition from beginning on up to several ten nanometers thickness. Spectroscopy under different polarization conditions reveals that isotropic layers have formed, which is supported by the special molecular properties of the material under investigation.
Effect of postdeposition annealing on electrical properties of RF‐magnetron sputtered CeOx gate on 4H‐silicon carbide
Authors: Chuah SooKiet , Cheong KuanYew , Lockman Zainovia , Hassan Zainuriah
Published: March 2011

This research investigated the electrical characteristics of CeOx thin films deposited on n‐type 4H‐SiC via RF‐magnetron sputtering technique. Postdeposition annealing of CeOx was performed at different annealing temperatures (400, 600, 800, and 1000 °C) for 30 min in an argon ambient. The thickness of the deposited CeOx ranging from 30 to 40 nm was measured by an ellipsometer. All annealed samples showed smooth surface morphology without any physical defects. In this work, the lowest root‐mean square surface roughness was detected at samples annealed at 1000 °C. Prior to electrical characterization, all annealed samples demonstrated a positive flat‐band voltage shift indicating that negative effective oxide charge was present in the oxide layer. The sample annealed at 1000 °C revealed the lowest effective oxide charge and interface trap density as compared with other samples. The calculated interface trap density and effective oxide charge from high‐frequency capacitance–voltage curve were correlated with leakage current density and electric breakdown field. The Fowler–Nordheim tunneling mechanism only occurred in the sample annealed at 1000 °C. The leakage current density and electric breakdown field were enhanced as the postdeposition annealing increased to 1000 °C as compared with other samples.
High pressure semiconductor physics: Looking toward the future on the shoulder of the past
Authors: Yu Peter Y.
Published: March 2011

High pressure measurements attracted attention from the Semiconductor Physics community after the discovery of William Paul's Empirical Rule. The technique gained further momentum with the invention of the diamond‐anvils high pressure cell. Since diamond is transparent from near IR to near UV many forms of optical spectroscopy (such as photoluminescence, modulation spectroscopy, and Raman scattering) have now been routinely carried out under high pressure. The fact that diamonds are also transparent to X‐ray means structural phase transitions induced by pressure can be studied together with optical measurements. Further advances, such as electrical and magnetic measurements under hydrostatic (and sometimes quasi‐hydrostatic) high pressure conditions, have established high pressure as a general, powerful, and indispensable technique in studying semiconductors. From a review of these past achievements I will attempt to “predict” how high pressure techniques will impact semiconductor physics in the future. I will draw examples from areas as diverse as new materials for spintronics and renewable energies, topological insulators to possible multi‐ferroic semiconductors.
Comparative study of GaAs and GaInNAs/GaAs multi‐quantum well solar cells
Authors: Royall B. , Balkan N. , Mazzucato S. , Khalil H. , Hugues M. , Roberts J. S.
Published: March 2011

Current–voltage (I–V) characteristics together with spectral quantum efficiency (QE) measurements are performed on a GaAs control and GaInNAs/GaAs multi‐quantum well (MQW) solar cell under illumination with the AM1.5G spectrum. Nitrogen and Indium composition in the GaInNAs wells were selected as to ensure lattice matching to GaAs. The wells are shown to extend the spectral response to longer wavelengths but also cause a reduction in the QE at wavelengths below the GaAs band gap. Furthermore, the addition of wells generally causes a large decrease in open circuit voltage due to the increased dark current. The MQW cell reaches an efficiency of 5% compared to 8.5% for the GaAs control cell.