bluuebunny/crossref_metadata_2025 huggingface dataset:
Dye‐Doped Polyhedral Oligomeric Silsesquioxane (POSS)‐Modified Polymeric Matrices for Highly Efficient and Photostable Solid‐State Lasers
Authors: Sastre Roberto , Martín Virginia , Garrido Leoncio , Chiara José Luis , Trastoy Beatriz , García Olga , Costela Angel , García‐Moreno Inmaculada
Published: September 2009

Here, the design, synthesis, and characterization of laser nanomaterials based on dye‐doped methyl methacrylate (MMA) crosslinked with octa(propyl‐methacrylate) polyhedral oligomeric silsesquioxane (8MMAPOSS) is reported in relation to their composition and structure. The influence of the silicon content on the laser action of the dye pyrromethene 567 (PM567) is analyzed in a systematic way by increasing the weight proportion of POSS from 1 to 50%. The influence of the inorganic network structure is studied by replacing the 8MMAPOSS comonomer by both the monofunctionalized heptaisobutyl‐methacryl‐POSS (1MMAPOSS), which defines the nanostructured linear network with the POSS cages appearing as pendant groups of the polymeric chains, and also by a new 8‐hydrogenated POSS incorporated as additive to the polymeric matrices. The new materials exhibit enhanced thermal, optical, and mechanical properties with respect to the pure organic polymers. The organization of the molecular units in these nanomaterials is studied through a structural analysis by solid‐state NMR. The domain size of the dispersed phase assures a homogeneous distribution of POSS into the polymer, thus, a continuous phase corresponding to the organic matrix incorporates these nanometer‐sized POSS crosslinkers at a molecular level, in agreement with the transparency of the samples. The silicon–oxygen core framework has to be covalently bonded into the polymer backbone instead of being a simple additive and both the silica content and crosslinked degree exhibit a critical influence on the laser action.
Preparation of Inorganic Materials Using Ionic Liquids
Authors: Ma Zhen , Yu Jihong , Dai Sheng
Published: September 2009

Conventional synthesis of inorganic materials relies heavily on water and organic solvents. Alternatively, the synthesis of inorganic materials using, or in the presence of, ionic liquids represents a burgeoning direction in materials chemistry. Use of ionic liquids in solvent extraction and organic catalysis has been extensively studied, but their use in inorganic synthesis has just begun. Ionic liquids are a family of non‐conventional molten salts that can act as templates and precursors to inorganic materials, as well as solvents. They offer many advantages, such as negligible vapor pressures, wide liquidus ranges, good thermal stability, tunable solubility for both organic and inorganic molecules, and much synthetic flexibility. In this Review, the use of ionic liquids in the preparation of several categories of inorganic and hybrid materials (i.e., metal structures, non‐metal elements, silicas, organosilicas, metal oxides, metal chalcogenides, metal salts, open‐framework structures, ionic liquid‐functionalized materials, and supported ionic liquids) is summarized. The status quo of the research field is assessed, and some future perspectives are furnished.
A Diversified Library of Bacterial and Fungal Bifunctional Cytochrome P450 Enzymes for Drug Metabolite Synthesis
Authors: Weis Roland , Winkler Margit , Schittmayer Matthias , Kambourakis Spiros , Vink Mandy , Rozzell J. David , Glieder Anton
Published: September 2009

Innovative biohydroxylation catalysts for the preparation of drug metabolites were developed from scratch. A set of bacterial and fungal sequences of putative and already known bifunctional P450 enzymes was identified by protein sequence alignments, expressed in Escherichia coli and characterised. Notably, a fungal self‐sufficient cytochrome P450 (CYP) from Aspergillus fumigatus turned out to be especially stable during catalyst preparation and application and also in presence of organic co‐solvents. To enhance the catalytic activity and broaden the substrate specificity of those variants with high expression levels prominent single mutations were introduced. Selected improved variants were then used as lyophilised bacterial lysates for the synthesis of 4′‐hydroxydiclofenac and 6‐hydroxychlorzoxazone, the two metabolites of active pharmaceutical compounds diclofenac and chlorzoxazone representing the same metabolites as generated by human P450s.
Samarium Powder‐Catalyzed Palladium‐Free and Ligand‐Free Sonogashira Coupling Reactions
Authors: Mao Jincheng , Wu Minyan , Xie Guanlei , Ji Shunjun
Published: September 2009

A study of samarium powder‐catalyzed cross‐coupling reactions of aryl halides with terminal alkynes is described. The couplings performed in the polyethylene glycol PEG‐600 provided the corresponding coupling products in good yields. The first example of palladium‐free, copper‐free and amine‐free catalytic system for Sonogashira couplings is presented in the absence of ligand.
Chiral Polyamino Alcohols via Hydroaminomethylation: A New Class of Polyamines for Dendritic Cores and Ligand Precursors
Authors: Subhani Muhammad Afzal , Müller Kai‐Sven , Eilbracht Peter
Published: September 2009

In this contribution, the synthesis of a new class of chiral polyamino alcohols (PAA) via a two‐step hydroaminomethylation/hydrolysis procedure is reported. The chiral polyamines are obtained by hydroaminomethylation of N‐olefinic oxazolidinones with different amines in first step followed by hydrolysis of the resulting polyamines to give the chiral PAA in the second step. The dendritic chiral PAA (Mw=1300–1400 g mol−1) are also synthesized efficiently through a multifold hydroaminomethylation/hydrolysis procedure. Furthermore, chiral PAA are investigated as ligands in ruthenium‐catalyzed asymmetric hydrogen transfer reduction of acetophenone to 1‐phenyl alcohol.
“Click” Polymer‐Supported Palladium Nanoparticles as Highly Efficient Catalysts for Olefin Hydrogenation and Suzuki Coupling Reactions under Ambient Conditions
Authors: Ornelas Cátia , Diallo Abdou K. , Ruiz Jaime , Astruc Didier
Published: September 2009

Complexation of palladium(II) acetate [Pd(OAc)2] or dipotassium tetrachloropalladate [K2PdCl4] to “click” polymers functionalized with phenyl, ferrocenyl and sodium sulfonate groups gave polymeric palladium(II)‐triazolyl complexes that were reduced to “click” polymer‐stabilized palladium nanoparticles (PdNPs). Transmission electron microscopy (TEM) showed that reduction using sodium borohydride (NaBH4) produced PdNPs in the 1–3 nm range of diameters depending on the nature of the functional group, whereas slow reduction using methanol yielded PdNPs in the 22–25 nm range. The most active of these PdNPs (0.01% mol Pd), stabilized by poly(ferrocenyltriazolylmethyl)styrene, catalyzed the hydrogenation of styrene at 25 °C and 1 atm hydrogen, with turnover numbers (TONs) of 200,000. When stabilized by the water‐soluble poly(sodium sulfonate‐triazolylmethyl)styrene, the PdNPs (0.01% mol Pd) catalyze the Suzuki–Miyaura coupling between iodobenzene (PhI) and phenylboronic acid [PhB(OH)2] in water/ethanol (H2O/EtOH) at 25 °C with TONs of 8,200. This high catalytic activity is comparable to that obtained with “click” dendrimer‐stabilized PdNPs under ambient conditions.
A Symmetry‐Based Synthesis of the Heterobicyclic Core of the Zaragozic Acids/Squalestatins
Authors: Wang Yuzhou , Kataeva Olga , Metz Peter
Published: September 2009

The pseudo C2‐symmetrical diketone 22 was efficiently constructed from furan‐3,4‐dimethanol (7) using a two‐directional route featuring a double asymmetric dihydroxylation. Acidic hydrolysis of the cyclopentylidene acetals of 22 triggered a selective cyclization of the resulting hexaol diketone to generate the 2,8‐dioxabicyclo[3.2.1]octane core of the zaragozic acids/squalestatins. Chemoselective oxidative cleavage of a superfluous two‐carbon appendage and further functional group manipulations yielded the enantiomerically pure triester 30, which offers itself as a general heterobicyclic building block for naturally occurring zaragozic acids/squalestatins and unnatural analogues.
Diethylzinc: A Simple and Efficient Catalyst for the Swift Hydroamination at Room Temperature
Authors: Pissarek Jens‐Wolfgang , Schlesiger David , Roesky Peter W. , Blechert Siegfried
Published: September 2009

Diethylzinc and dimethylanilinium tetrakis(pentafluorophenyl)borate were found to catalyze hydroaminations at room temperature in high efficiency and very short reaction times. The reactivity of the proposed cationic zinc species, which is assumed to catalyze the reaction, strongly depends on the coordinative abilities of the counterion.
Cross‐Linked Enzyme Aggregates of Chloroperoxidase: Synthesis, Optimization and Characterization
Authors: Perez Daniel I. , van Rantwijk Fred , Sheldon Roger A.
Published: September 2009

In this study we have optimized the conditions to precipitate and cross‐link the enzyme chloroperoxidase (EC 1.11.1.10) from Caldariomyces fumago (CPO) using 1,2‐dimethoxyethane as the precipitating agent. The coprecipitation of the enzyme with albumin and pentaethylenehexamine was needed for optimum results, presumably due to the low number of lysines available in CPO. The enzyme was immobilized with an activity recovery of 68%. The cross‐linked enzyme aggregate showed higher temperature and pH stability, and better hydrogen peroxide tolerance than the free enzyme.
An Efficient Combined Electrochemical and Ultrasound Assisted Synthesis of Imidazole‐2‐Thiones
Authors: Feroci Marta , Orsini Monica , Inesi Achille
Published: September 2009

The electrochemical reduction of 1,3‐dialkylimidazolium ionic liquids gave the corresponding N‐heterocyclic carbenes that, after reaction with elemental sulfur and ultrasound irradiation, yielded 1,3‐dialkylimidazole‐2‐thiones in very high yields. The reaction is very clean, produces no side‐products and avoids the use of any other added reagent.
Ruthenium‐Catalyzed Oxidative Homo‐Coupling of 2‐Arylpyridines
Authors: Guo Xiangyu , Deng Guojun , Li Chao‐Jun
Published: September 2009

A ruthenium‐catalyzed oxidative homo‐coupling reaction of 2‐arylpyridines via CH activation was developed. The reaction could tolerate various functional groups on both the aryl and the pyridyl rings to afford a series of dimerized products with iron(III) chloride (FeCl3) as a stoichiometric oxidant. A tentative mechanism was proposed for this oxidative CH/CH homo‐coupling.
Optimization of multicomponent photopolymer formulations using high‐throughput analysis and kinetic modeling
Authors: Johnson Peter M. , Bowman Christopher N. , Stansbury Jeffrey W.
Published: September 2009

While high throughput and combinatorial techniques have played an instrumental role in materials development and implementation, numerous problems in materials science and engineering are too complex and necessitate a prohibitive number of experiments, even when considering high throughput and combinatorial approaches, for a comprehensive approach to materials design. Here, we propose a unique combination of high throughput experiments focused on binary formulations that, in combination with advanced modeling, has the potential to facilitate true materials design and optimization in ternary and more complex systems for which experiments are never required. Extensive research on the development of photopolymerizable monomer formulations has produced a vast array of potential monomer/comonomer, initiator and additive combinations. This array dramatically expands the range of material properties that are achievable; however, the vast number of potential formulations has eliminated any possibility of comprehensive materials design or optimization. This limitation is addressed by maximizing the benefits and unique capabilities of high throughput experimentation coupled with predictive models for material behavior and properties. The high throughput experimentation‐model combination is useful to collect a limited amount of data from as few as 11 experiments on binary combinations of 10 analyzed monomers, and then use this limited data set to predict and optimize formulation properties in ternary resins that would have necessitated at least 1000 high throughput experiments and several orders of magnitude greater numbers of traditional experiments. A data analysis approach is demonstrated, and the model development and implementation for one model application in which a range of material properties are prescribed, and an optimal formulation that meets those properties is predicted and evaluated. © 2009 American Institute of Chemical Engineers AIChE J, 2010
Occupational health crossing borders—Part 1: Concept, teaching methods, and user evaluation of the first international summer school in Munich, Germany
Authors: Radon Katja , Ehrenstein Vera , Bigaignon‐Cantineau Janine , Vellore Arun Dev , Fingerhut Marilyn , Nowak Dennis ,   and the Occupational Health Crossing Borders Summer School Team
Published: September 2009

Background

Occupational health and safety (OHS) is relevant for occupational health professionals (OHP) throughout the world. However, training opportunities are often limited and exchange between OHP from industrialized and developing countries is sparse. We aimed to contribute to the international exchange of OHP through a 2‐week summer school program.

Methods

Twenty‐three OHP from 11 countries participated. Teaching methods included interactive lectures, participants' presentations, case‐based e‐learning, enterprise visits, and hands‐on sessions. After completion, participants evaluated the course.

Results

OHS systems of 18 different countries were presented using the same set of clinical cases as a starting point. Opportunities and challenges in the different OHS systems were considered. On median, participants rated the course as excellent and totally agreed that it will help them in their daily work.

Conclusions

An international summer school teaching basic aspects of different OHS systems is a useful tool for training and exchange at the global level. Am. J. Ind. Med. 52:774–781, 2009. © 2009 Wiley‐Liss, Inc.
Synthesis and characterization of a lactic acid‐based thermoset resin suitable for structural composites and coatings
Authors: Åkesson Dan , Skrifvars Mikael , Seppälä Jukka , Turunen Minna , Martinelli Anna , Matic Aleksandar
Published: September 2009

A new biobased polyester resin was developed for thermoset composite applications. The resin is potentially inexpensive and can be produced industrially by relatively simple means. The resin consists of star‐shaped methacrylated oligomers of lactic acid (LA). LA oligomers were synthesized in a two‐step process: in the first step, oligomers of LA were polymerized by direct condensation of LA. In the second step, the oligomers were end‐functionalized by methacrylic anhydride. The resin was characterized by differential scanning calorimetry, Raman spectroscopy, NMR, rubber process analyzer, and TOF‐SIMS. Tests show that the resin can be crosslinked into a rigid network within a couple of minutes upon thermal initiation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Shielding and dielectric properties of sulfonic acid‐doped π‐conjugated polymer in 8.2–12.4 GHz frequency range
Authors: Ohlan Anil , Singh Kuldeep , Dhawan S. K.
Published: September 2009

This article deals with dielectric and electromagnetic interference shielding properties of the polyaniline doped with dodecyl benzene sulfonic acid (DBSA) synthesized by microemulsion polymerization of aniline in aqueous solution of DBSA. Dielectric constant and shielding effectiveness due to absorption (SEA) were calculated using S‐parameter obtained from the vector network analyzer in 8.2–12.4 GHz frequency range. Maximum SEA of 26 dB (>99%) was achieved for polymer sample. The real part ε′ of complex permittivity shows small variation, whereas the imaginary part ε″ is found to decrease with the increase in frequency. Different formulations have been performed to see the effect of monomer to dopant ratio on intrinsic properties of polyaniline. Further characterization of polymer was carried out by UV–visible and thermal gravimetric analysis, whereas the conductivity measurements were carried out by the four‐probe method.© 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effects of alkali on properties of nanoscale 2,9 dimethyl quinacridone/poly(styrene‐maleic acid) composite dispersion
Authors: Shao‐Hai Fu , Chang‐Hai Xu
Published: September 2009

Nanoscale 2,9 dimethyl quinacridone (P.R.122) encapsulated by copolymer of styrene and maleic acid (PSMA) was prepared via phase separation technique followed by the preparation of composite dispersions. Experimental results showed that sodium hydroxide provided the dispersion the smallest particle size and the highest stability when compared with other additives, regardless of it being taken as dispersant or the other neutralization reagent. An optimal process was attained by using sodium hydroxide with a dosage of 0.60 times of molar amount of COOH groups in PSMA when P.R.122/PSMA composite dispersion was treated at 45°C for 30 min. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Rheology of poly(vinyl chloride) plastisol: Effect of a particular nonionic cosurfactant
Authors: Tomás A. , Rasteiro M. G. , Gando‐Ferreira L. , Figueiredo S.
Published: September 2009

The rheology of poly(vinyl chloride) plastisols is affected by many aspects of the formulations, such as type and concentration of each component, temperature and, perhaps most important, the polymer properties. Taking into consideration the surfactants normally present during the polymerization reaction, in this work, a different approach was followed. Besides the usual polymerization surfactants, a particular ester‐type emulsifier was also added in a postpolymerization stage. The results show a particle aggregation effect in the initial aqueous dispersion (latex) that promotes a significant decrease in the viscosity level, aging profile, and different viscoelastic properties of the latter plastisols. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Polypropylene/combinational inorganic filler micro‐/nanocomposites: Synergistic effects of micro‐/nanoscale combinational inorganic fillers on their mechanical properties
Authors: Chen Deliang , Yang Huaming
Published: September 2009

Polypropylene (PP) has wide applications in various areas, but its low‐temperature brittleness and low moduli have limited its applications in engineering areas. This article reported micro‐/nanoscale combinational inorganic fillers (CIFs) to reinforce PP‐matrix composites as the first example. The CIFs consisted of plate‐like talc (T), needle‐like wollastonite (W), and nano‐Al2O3 (N). The PP/CIFs specimens were fabricated via a process of twin‐screw extrusion and screw‐type injection molding. The mechanical properties and thermal deflection temperature (HDT) of the PP/CIF composites were tested according to the corresponding standards, and the morphologies of the tensile‐fractured sections were observed using FE‐SEM. The PP/WT composites had higher mechanical properties and HDTs than those of either PP/W or PP/T. Small amounts of Al2O3 nanocrystals together with WT simultaneously strengthened and toughened the PP‐matrix composites. The PP/WTN composite with 2.6% of nano‐Al2O3 had well‐balanced properties, enhanced by a large increment when compared with the PP matrix or PP/WT composites. The enhancements should be attributed to the synergistic effects of the CIFs not only in the aspect of various shapes (plate‐like, needle‐like, and spherical) but also in hierarchical size‐levels (microscale and nanoscale). The novel strategy overcame the limitation of conventional rigid modification and solved the problem of uniform dispersion of nanocrystals in polymer matrices. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis of polydimethylsiloxane‐containing block copolymers via reversible addition fragmentation chain transfer (RAFT) polymerization
Authors: Wadley Maurice L. , Cavicchi Kevin A.
Published: September 2009

Low polydispersity polydimethylsiloxane (PDMS) was end functionalized with a reversible addition fragmentation chain transfer (RAFT) agent by the esterification of hydroxyl terminated PDMS with a carboxylic acid functional RAFT agent. These PDMS‐RAFT agents were able to control the free radical polymerization of styrene and substituted styrene monomers to produce PDMS‐containing block copolymers with low polydispersities and targeted molecular weights. A thin film of polydimethylsiloxane‐block‐polystyrene was prepared by spin coating and exhibited a microphase separated morphology from scanning force microscopy measurements. Controlled swelling of these films in solvent vapor produced morphologies with significant long‐range order. This synthetic route will allow the straightforward production of PDMS‐containing block copolymer libraries that will be useful for investigating their thin film morphological behavior, which has applications in the templating of nanostructured materials.© 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Salts and Ionic Liquids of Resonance Stabilized Amides
Authors: Brand Harald , Martens Jörn , Mayer Peter , Schulz Axel , Seibald Markus , Soller Thomas
Published: September 2009

The synthesis, structure, and bonding of alkali salts of resonance stabilized amides, such as diformylamide (dfa), formylcyanoamide (fca), nitrocyanoamide (nca), and for comparision, the well‐known dicyanoamide (dca), are discussed on the basis of experimental and theoretical data. The first structural reports of K(18‐crown‐6)+dfa−, K(18‐crown‐6)+fca−, Na+nca−, and Li(TMEDA)+dca− are presented. Examination of the X‐ray data reveals almost planar anions with strong cation–anion interactions resulting in network‐like structures in the solid state. For comparison, the X‐ray structures of covalently bound phenyldicyanoamide and diformamide are also discussed. The thermal behavior of the alkali salts of these amides is studied by thermoanalytical experiments. Moreover, several novel ionic liquids based on resonance stabilized amides have been prepared and were fully characterized, namely the dfa, fca, and nca salts of EMIM (1‐ethyl‐3‐methyl‐imidazolium), BMIM (1‐butyl‐3‐methyl‐imidazolium), and HMIM (1‐hexyl‐3‐methyl‐imidazolium). Most of them are liquid at room temperature, except BMIM+fca− that melts at 32 °C. These ionic liquids are neither heat nor shock sensitive, are thermally stable up to over 200 °C, and can be prepared easily in large quantities.
Review of the pyrolysis platform for coproducing bio‐oil and biochar
Authors: Laird David A. , Brown Robert C. , Amonette James E. , Lehmann Johannes
Published: September 2009

Pyrolysis is a relatively simple, inexpensive, and robust thermochemical technology for transforming biomass into bio‐oil, biochar, and syngas. The robust nature of the pyrolysis technology, which allows considerable flexibility in both the type and quality of the biomass feedstock, combined with a distributed network of small pyrolysis plants, would be compatible with existing agriculture and forestry infrastructure. Bio‐oil can be used as a fuel in existing industrial boilers. Biochar can be used with existing infrastructure as a replacement for pulverized coal; however, use of biochar as a soil amendment results in significant environmental and agronomic benefits. Soil application of biochar is a means of sequestering large amounts of C and may have other greenhouse gas benefits. Preliminary reports of the impact of soil biochar applications on crop yields indicate that biochar quality is very important. Biochar is an effective adsorbent for both nutrients and organic contaminants, hence the presence of biochar in soils has been shown to improve water quality in column leaching and field lysimeters studies and it is anticipated to do the same for agricultural watersheds.

The pyrolysis platform for producing bio‐oil and biochar from biomass appears to be a practical, effective, and environmentally sustainable means of producing large quantities of renewable bioenergy while simultaneously reducing emissions of greenhouse gases. At the present time, the pyrolysis platform is economically marginal because markets for bio‐oil and biochar are highly competitive. However, if the USA adopts a program for controlling greenhouse gases, the pyrolysis platform would be highly competitive. Published in 2009 by John Wiley & Sons, Ltd
The role that lignocellulosic feedstocks and various biorefining technologies can play in meeting Ireland's biofuel targets
Authors: Hayes Daniel J. , Hayes Michael H. B.
Published: September 2009

This paper considers the contribution that biorefineries, through the production of second‐generation biofuels from lignocellulosic feedstocks, can make in the Republic of Ireland to the mandated 10% transport biofuel quotient for 2020. An emphasis is placed on the avoidance of land‐use conflict issues and, hence, on the prioritization of waste/residue utilization before dedicated energy crops are grown. It is concluded that up to 5.3% of the 2010 demand for biofuels can be met from the utilization of feasible quantities of wastes and residues in near‐term biorefining technologies and that 5% of the 2020 petrol and diesel demand can be met via processing a similar quantity of waste in advanced biorefining processes based on consolidated bioprocessing micro‐organisms and syngas‐reforming catalysts. The remaining biofuel requirements for 2020 can be met by processing energy crops. Between 1.4% and 15.9% of the agricultural area of Ireland is required for the production of these crops, depending on the particular feedstock and technology employed. The production of a high‐yielding Miscanthus crop that is harvested directly after senescence will place the minimum requirement on Irish land. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd
Toward a common classification approach for biorefinery systems
Authors: Cherubini Francesco , Jungmeier Gerfried , Wellisch Maria , Willke Thomas , Skiadas Ioannis , Van Ree René , de Jong Ed
Published: September 2009

This paper deals with a biorefinery classification approach developed within International Energy Agency (IEA) Bioenergy Task 42. Since production of transportation biofuels is seen as the driving force for future biorefinery developments, a selection of the most interesting transportation biofuels until 2020 is based on their characteristics to be mixed with gasoline, diesel and natural gas, reflecting the main advantage of using the already‐existing infrastructure for easier market introduction.

This classification approach relies on four main features: (1) platforms; (2) products; (3) feedstock; and (4) processes. The platforms are the most important feature in this classification approach: they are key intermediates between raw materials and final products, and can be used to link different biorefinery concepts. The adequate combination of these four features represents each individual biorefinery system. The combination of individual biorefinery systems, linked through their platforms, products or feedstocks, provides an overview of the most promising biorefinery systems in a classification network. According to the proposed approach, a biorefinery is described by a standard format as ‘platform(s) – products – and feedstock(s)’. Processes can be added to the description, if further specification is required. Selected examples of biorefinery classification are provided; for example, (1) one platform (C6 sugars) biorefinery for bioethanol and animal feed from starch crops (corn); and (2) four platforms (lignin/syngas, C5/C6 sugars) biorefinery for synthetic liquid biofuels (Fischer‐Tropsch diesel), bioethanol and animal feed from lignocellulosic crops (switchgrass).

This classification approach is flexible as new subgroups can be added according to future developments in the biorefinery area. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd
Prospective and impacts of whole cell mediated alcoholysis of renewable oils for biodiesel production
Authors: Sun Ting , Du Wei , Liu Dehua
Published: September 2009

Biodiesel has received considerable attention during the past decade as a renewable, biodegradable and environmentally friendly fuel. There are extensive reports about immobilized lipase‐mediated alcoholysis for biodiesel production and much progress has been achieved. In recent years, much attention has been paid to whole cell as the catalyst for biodiesel production. Whole cell process can be expected to reduce the biocatalyst cost considerably since separation and immobilization can be realized spontaneously during the process of cell cultivation. Currently, research related to whole cell mediated alcoholysis for biodiesel production is mainly focused on the following three aspects: (1) the optimization in cultivation of whole cell catalyst to obtain the maximal lipase activity; (2) the modification of whole cell catalyst to improve its catalytic performance; and (3) the application of whole cell catalyst for biodiesel production. This mini‐review covers the aforementioned research fields and the prospects of whole cell catalyst applied to biodiesel production are also discussed. Copyright © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd
First trimester paroxetine use and the prevalence of congenital, specifically cardiac, defects: A meta‐analysis of epidemiological studies
Authors: Wurst Keele E. , Poole Charles , Ephross Sara A. , Olshan Andrew F.
Published: September 2009

BACKGROUND: Several studies have evaluated maternal first trimester paroxetine use and the prevalence of congenital defects, particularly cardiac defects. To synthesize current epidemiologic information, a meta‐analysis was conducted. METHODS: A systematic literature search was conducted for original research published from January 1, 1992, through September 30, 2008. Results were extracted using predefined criteria, and authors were contacted for additional information when necessary. Compiled results were evaluated for funnel plot asymmetry, heterogeneity, and study characteristic associations. Where appropriate, fixed‐effect summary estimates were calculated and sensitivity analyses performed. RESULTS: Twenty reports (11 including results for aggregated congenital and combined cardiac defects, six for aggregated congenital defects only, and three for combined cardiac defects only) met prespecified inclusion criteria. There was little evidence of funnel plot asymmetry or overall heterogeneity. Summary estimates were produced for combined cardiac defects (prevalence odds ratio [POR], 1.46; 95% confidence interval [CI], 1.17–1.82) and aggregated congenital defects (POR, 1.24; 95% CI, 1.08–1.43) and first trimester paroxetine use. Some study characteristics may be associated with differential POR estimates for paroxetine and either combined cardiac or aggregated congenital defects. CONCLUSIONS: This meta‐analysis found little evidence of publication bias or overall statistical heterogeneity and only weak evidence of associations with some study characteristics. Although subject to limitations, the summary estimate indicates an increased prevalence of combined cardiac defects with first trimester paroxetine use. The summary estimate also indicates an increased prevalence of aggregated congenital defects with paroxetine; however, this association may be explained, in part, by the increased prevalence of combined cardiac defects. Birth Defects Research (Part A), 2010. © 2009 Wiley‐Liss, Inc.
Effects of prenatal exposure to a 50‐Hz magnetic field on one‐trial passive avoidance learning in 1‐day‐old chicks
Authors: Sun Huaying , Che Yi , Liu Xiaofen , Zhou Dongming , Miao Yingda , Ma Yuanye
Published: September 2009

We investigated memory impairment in newly hatched chicks following in ovo exposure to a 50‐Hz magnetic field (MF) of 2 mT (60 min/day) on embryonic days 12–18. Isolated and paired chicks were used to test the effect of stress during training, and memory retention was tested at 10, 30, and 120 min, following exposure to a bitter‐tasting bead (100% methylanthranilate). Results showed that memory was intact at 10 min in both isolated and paired chicks with or without MF exposure. However, while isolated chicks had good memory retention levels at 30 and 120 min, those exposed to MF did not. The results suggest a potential disruption of memory formation following in ovo exposure to MF, with this effect only evident in the more stressed, isolated chicks. Bioelectromagnetics 31:150–155, 2010. © 2009 Wiley‐Liss, Inc.
Microwell engineering characterization for mammalian cell culture process development
Authors: Barrett Timothy A. , Wu Andrew , Zhang Hu , Levy M. Susana , Lye Gary J.
Published: September 2009

Experimentation in shaken microplate formats offers a potential platform technology for the rapid evaluation and optimization of cell culture conditions. Provided that cell growth and antibody production kinetics are comparable to those found in currently used shake flask systems then the microwell approach offers the possibility to obtain early process design data more cost effectively and with reduced material requirements. This work describes a detailed engineering characterization of liquid mixing and gas–liquid mass transfer in microwell systems and their impact on suspension cell cultures. For growth of murine hybridoma cells producing IgG1, 24‐well plates have been characterized in terms of energy dissipation (P/V) (via Computational Fluid Dynamics, CFD), fluid flow, mixing and oxygen transfer rate as a function of shaking frequency and liquid fill volume. Predicted kLa values varied between 1.3 and 29 h−1; liquid‐phase mixing time, quantified using iodine decolorization experiments, varied from 1.7 s to 3.5 h; while the predicted P/V ranged from 5 to 35 W m−3. CFD simulations of the shear rate predicted hydrodynamic forces will not be detrimental to cells. For hybridoma cultures however, high shaking speeds (>250 rpm) were shown to have a negative impact on cell growth, while a combination of low shaking speed and high well fill volume (120 rpm, 2,000 µL) resulted in oxygen limited conditions. Based on these findings a first engineering comparison of cell culture kinetics in microwell and shake flask formats was made at matched average energy dissipation rates. Cell growth kinetics and antibody titer were found to be similar in 24‐well microtiter plates and 250 mL shake flasks. Overall this work has demonstrated that cell culture performed in shaken microwell plates can provide data that is both reproducible and comparable to currently used shake flask systems while offering at least a 30‐fold decrease in scale of operation and material requirements. Linked with automation this provides a route towards the high throughput evaluation of robust cell lines under realistic suspension culture conditions. Biotechnol. Bioeng. 2010; 105: 260–275. © 2009 Wiley Periodicals, Inc.
Profiling of host cell proteins by two‐dimensional difference gel electrophoresis (2D‐DIGE): Implications for downstream process development
Authors: Jin Mi , Szapiel Nicolas , Zhang Jennifer , Hickey John , Ghose Sanchayita
Published: September 2009

Host cell proteins (HCPs) constitute a major group of impurities for biologic drugs produced using cell culture technology. HCPs are required to be closely monitored and adequately removed in the downstream process. However, HCPs are a complex mixture of proteins with significantly diverse molecular and immunological properties. An overall understanding of the composition of HCPs and changes in their molecular properties upon changes in upstream and harvest process conditions can greatly facilitate downstream process design. This article describes the use of a comparative proteomic profiling method viz. two‐dimensional difference gel electrophoresis (2D‐DIGE) to examine HCP composition in the harvest stream of CHO cell culture. The effect of upstream process parameters such as cell culture media, bioreactor control strategy, feeding strategy, and cell culture duration/cell viability on HCP profile was examined using this technique. Among all the parameters studied, cell viability generated the most significant changes on the HCP profile. 2D‐DIGE was also used to compare the HCP differences between monoclonal antibody producing and null cell cultures. The HCP species in production cell culture was found to be well represented in null cell culture, which confirms the suitability of using the null cell culture for immunoassay reagent generation. 2D‐DIGE is complimentary to the commonly used HCP immunoassay. It provides a direct comparison of the changes in HCP composition under different conditions and can reveal properties (pI, MW) of individual species, whereas the immunoassay sensitively quantifies total HCP amount in a given sample. Biotechnol. Bioeng. 2010; 105: 306–316. © 2009 Wiley Periodicals, Inc.
Post‐translational events of a model reporter protein proceed with higher fidelity and accuracy upon mild hypothermic culturing of Chinese hamster ovary cells
Authors: Masterton Rosalyn J. , Roobol Anne , Al‐Fageeh Mohamed B. , Carden Martin J. , Smales C. Mark
Published: September 2009

Chinese hamster ovary cells (CHO) are routinely used in industry to produce recombinant therapeutic proteins and a number of studies have reported increased recombinant mRNA levels at temperatures <37°C. Surprisingly, the effect of reduced temperature on mRNA translation in CHO cells has not been investigated despite this process being highly responsive to environmental stresses. The relationship between low temperature culturing of CHO cells and mRNA translation was therefore investigated using labeling studies and dual luciferase reporter gene technology. Global protein synthetic capacity was not greatly affected at 32°C but was diminished at lower temperatures. The expression of both cap‐dependent and cap‐independent (IRES driven) mRNA translated luciferase reporter gene activity was highest at 32°C on a per cell basis and this was partially accounted for by increased mRNA levels. Importantly, post‐translational events appear to proceed with higher fidelity and accuracy at 32 than 37°C resulting in increased yield of active protein as opposed to an increase in total polypeptide synthesis. Therefore at 32°C recombinant cap‐dependent mRNA translation appears sufficient to maintain recombinant protein yields on a per cell basis and this is associated with improved post‐translational processing. Biotechnol. Bioeng. 2010;105: 215–220. © 2009 Wiley Periodicals, Inc.
Enhanced protein production using HBV X protein (HBx), and synergy when used in combination with XBP1s in BHK21 cells
Authors: Jin Fang , Kretschmer Peter J. , Harkins Richard N. , Hermiston Terry W.
Published: September 2009

The demand of therapeutic protein production from mammalian cells has expanded greatly since the first biologic was approved in 1982. It remains a major challenge to exploit the exocytic pathway and increase cell viability during the production process. Hepatitis B virus X protein (HBx) is a multifunctional viral transcription activator that regulates a variety of cellular events including transcription, cell cycle and proliferation, survival, and apoptosis. As such it may address some of the current production challenges. In this study we demonstrate that HBx can enhance protein production during transient transfection and in stable cell lines. XBP1s is a potent transcription factor and has been demonstrated to enlarge the ER secretion pathway and increase protein production. We explored the possibility of combinational engineering of HBx with XBP1s in BHK21 cells. Our data revealed that combinational engineering of HBx with XBP1s further enhances protein production compared with HBx or XBP1s alone. Biotechnol. Bioeng. 2010; 105: 341–349. © 2009 Wiley Periodicals, Inc.
Prediction of protein solubility in Escherichia coli using logistic regression
Authors: Diaz Armando A. , Tomba Emanuele , Lennarson Reese , Richard Rex , Bagajewicz Miguel J. , Harrison Roger G.
Published: September 2009

In this article we present a new and more accurate model for the prediction of the solubility of proteins overexpressed in the bacterium Escherichia coli. The model uses the statistical technique of logistic regression. To build this model, 32 parameters that could potentially correlate well with solubility were used. In addition, the protein database was expanded compared to those used previously. We tested several different implementations of logistic regression with varied results. The best implementation, which is the one we report, exhibits excellent overall prediction accuracies: 94% for the model and 87% by cross‐validation. For comparison, we also tested discriminant analysis using the same parameters, and we obtained a less accurate prediction (69% cross‐validation accuracy for the stepwise forward plus interactions model). Biotechnol. Bioeng. 2010; 105: 374–383. © 2009 Wiley Periodicals, Inc.
Development of a polishing step using a hydrophobic interaction membrane adsorber with a PER.C6®‐derived recombinant antibody
Authors: Kuczewski Michael , Fraud Nathalie , Faber Rene , Zarbis‐Papastoitsis Gregory
Published: September 2009

Membrane chromatography has already proven to be a powerful alternative to polishing columns in flow‐through mode for contaminant removal. As flow‐through utilization has expanded, membrane chromatography applications have included the capturing of large molecules, including proteins such as IgGs. Such bind‐and‐elute applications imply the demand for high binding capacity and larger membrane surface areas as compared to flow‐through applications. Given these considerations, a new Sartobind Phenyl™ membrane adsorber was developed for large‐scale purification of biomolecules based on hydrophobic interaction chromatography (HIC) principles. The new hydrophobic membrane adsorber combines the advantages of membrane chromatography—virtually no diffusion limitation and shorter processing time—with high binding capacity for proteins comparable to that of conventional HIC resins as well as excellent resolution. Results from these studies confirmed the capability of HIC membrane adsorber to purify therapeutic proteins with high dynamic binding capacities in the range of 20 mg‐MAb/cm3‐membrane and excellent impurity reduction. In addition the HIC phenyl membrane adsorber can operate at five‐ to ten‐fold lower residence time when compared to column chromatography. A bind/elute purification step using the HIC membrane adsorber was developed for a recombinant monoclonal antibody produced using the PER.C6® cell line. Loading and elution conditions were optimized using statistical design of experiments. Scale‐up is further discussed, and the performance of the membrane adsorber is compared to a traditional HIC resin used in column chromatography. Biotechnol. Bioeng. 2010; 105: 296–305. © 2009 Wiley Periodicals, Inc.
Effect of stress and stress hormones on the hormone (insulin) binding of Tetrahymena
Authors: Csaba György , Pállinger Éva
Published: September 2009

The unicellular Tetrahymena pyriformis GL produce, store and secrete vertebrate‐like hormones. In earlier experiments the effect of different stressors on the hormone levels of Tetrahymena was studied and an elevation of these was found. In the present experiments the hormone binding was investigated, using flow cytometric method. FITC‐insulin binding was elevated after concentrated (5, 10, or 20 mg ml−1) NaCl or 0.01%, 0.1%, or 0.05% formaldehyde treatment, or after thermal stress (37°C). Serotonin given together with NaCl increased and together with formaldehyde decreased the binding. Histamine always decreased the binding and insulin was indifferent. Four hours after osmotic stress, hormone binding significantly decreased and this was not influenced by hormones. However, 4 h after formaldehyde stress the binding elevated and this was further increased by repeated hormone treatments. The results show that the stress in Tetrahymena provokes an activation of its hormonal system (hormone production and binding), which is differently influenced by exogeneously given hormones. Copyright © 2009 John Wiley & Sons, Ltd.
Cyclodextrin Aldehydes are Oxidase Mimics
Authors: Hauch Fenger Thomas , Bjerre Jeannette , Bols Mikael
Published: September 2009

Cyclodextrins containing 6‐aldehyde groups were found to catalyse oxidation of aminophenols in the presence of hydrogen peroxide. The catalysis followed Michaelis–Menten kinetics and is related to the catalysis previously observed with cyclodextrin ketones. A range of different cyclodextrin aldehydes were prepared containing one, two or more aldehydes at the primary rim (6‐positions) or a ethoxy‐2‐al or propoxy‐3‐al at the secondary rim. 2‐O‐ethoxy‐2‐al‐β‐cyclodextrin (22) was found to be the best catalyst. The aldehydes are in many cases better catalysts than the ketones, because of their powerful covalent binding of hydrogen peroxide.
An Integrated Catalytic and Transient Study of Sulfated Zirconias: Investigation of the Reaction Mechanism and the Role of Acidic Sites in n‐Butane Isomerization
Authors: Breitkopf Cornelia
Published: September 2009

The transient temporal analysis of products (TAP) pulse method has been applied to investigate the isomerization of n‐butane on sulfated zirconias at very low pressure. By combining these results with findings from XRD, XPS, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), temperature‐programmed desorption (TPD), and catalytic studies at atmospheric pressure, a wide range of pressure conditions can be accessed to study the influence of surface sulfate groups on the isomerization activity and the mechanism of this reaction. The catalytic activity of powder catalysts has been correlated to the surface site density of sulfates, with pyrosulfate structures playing a major role in the initiation of the reaction. The complex interplay between sulfate‐free and sulfate‐covered zirconia surfaces for the adsorption of alkanes has been investigated in detail, with TAP pulse experiments showing a monomolecular reaction pathway at low n‐butane partial pressures. Moreover, TAP pulse experiments have allowed detection of the reaction products of this initiation process, including butene and water, and have shown their influence on the deactivation of sulfated zirconias. Heats of adsorption have been calculated from the TAP pulse experiments.
New Nanocrystalline Cu/MnOx Catalysts Prepared from Supercritical Antisolvent Precipitation
Authors: Tang Zi‐Rong , Jones Christopher D. , Aldridge James K. W. , Davies Thomas E. , Bartley Jonathan K. , Carley Albert F. , Taylor Stuart H. , Allix Mathieu , Dickinson Calum , Rosseinsky Matthew J. , Claridge John B. , Xu Zhongling , Crudace Mandy J. , Hutchings Graham J.
Published: September 2009

Supercritical CO2 is used as an antisolvent to precipitate out nanostructured homogeneous mixtures of Cu2+ and Mn3+ with crystallites of 10–20 nm in diameter. Following calcination, this material forms a crystalline tetragonal spinel, CuMn2O4, with a branched chainlike structure with a length of 160–200 nm and diameters of approximately 40 nm. This new material is more than twice as active per unit surface area as the conventionally prepared hopcalite catalysts for the oxidation of carbon monoxide. This is the first time that homogeneous mixed oxides have been formed using this method.