bluuebunny/crossref_metadata_2025 huggingface dataset:
Overview of Genetic Diagnosis in Cancer
Authors: Korf Bruce , M. Mikhail Fady
Published: October 2007

Both cytogenetic and molecular genetic studies can contribute to the management of patients with cancer. In some cases genetic markers are specific to particular tumor types and are useful in diagnosis. This can be helpful in distinguishing histologically similar tumors that may respond differently to treatment and can sometimes be of prognostic value. Genetic markers can also be tools for following the response of a tumor to therapy, providing a sensitive means of detection of relapse. This introductory unit considers some of the types of genetic changes that occur in association with malignancies and major approaches used in their detection. Curr. Protoc. Hum. Genet. 55:10.1.1‐10.1.8. © 2007 by John Wiley & Sons, Inc.
Flow Cytometric Sorting of Bacterial Surface‐Displayed Libraries
Authors: Kenrick Sophia , Rice Jeffrey , Daugherty Patrick
Published: October 2007

The protocols herein detail methods for isolating binding peptides from a combinatorial library displayed on the surface of bacterial cells. These methods are appropriate for a variety of display scaffolds and a large range of library sizes, up to ∼5 × 109 or more. Instructions have been provided for isolating peptides that bind to both proteins and non‐protein targets, such as whole cells or inorganic particles. Qualitative analysis by flow cytometry can be exploited for bacterial libraries to characterize a displayed peptide's binding properties with a target of interest, and sorting conditions can be tuned to maximize binding affinity. Curr. Protocol. Cytom. 42:4.6.1‐4.6.27. © 2007 by John Wiley & Sons, Inc.
SYTO Probes: Markers of Apoptotic Cell Demise
Authors: Wlodkowic Donald , Skommer Joanna
Published: October 2007

As mechanistic studies on tumor cell death advance towards their ultimate translational goal, there is a need for specific, rapid, and high‐throughput analytical tools to detect diverse cell demise modes. Patented DNA‐binding SYTO probes, for example, are gaining increasing interest as easy‐to‐use markers of caspase‐dependent apoptotic cell death. They are proving convenient for tracking apoptosis in diverse hematopoietic cell lines and primary tumor samples, and, due to their spectral characteristics, appear to be useful for the development of multiparameter flow cytometry assays. Herein, several protocols for multiparametric assessment of apoptotic events using SYTO probes are provided. There are protocols describing the use of green fluorescent SYTO 16 and red fluorescent SYTO 17 dyes in combination with plasma membrane permeability markers. Another protocol highlights the multiparametric use of SYTO 16 dye in conjunction with the mitochondrial membrane potential sensitive probe, tetramethylrhodamine methyl ester (TMRM), and the plasma membrane permeability marker, 7‐aminoactinomycin D (7‐AAD). Curr. Protocol. Cytom. 42:7.33.1‐7.33.12. © 2007 by John Wiley & Sons, Inc.
Alternatives to Log‐Scale Data Display
Authors: Trotter Joseph
Published: October 2007

Traditional log‐scale data display of multiparameter immunofluorescence cytometry data has several perplexing intrinsic problems that are largely mitigated by recent transformation alternatives that are log‐like at the high end of the scale, near linear at the low end of the scale, and symmetrical about zero. These alternative log‐like display transformations provide a means for better interpretation and analysis of compensated data. Curr. Protocol. Cytom. 42:10.16.1‐10.16.11. © 2007 by John Wiley & Sons, Inc.
Detecting Protein‐Protein Interactions In Vivo with FRET using Multiphoton Fluorescence Lifetime Imaging Microscopy (FLIM)
Authors: Llères David , Swift Samuel , Lamond Angus I.
Published: October 2007

Protein interactions are critical for many processes in mammalian cells. Such interactions include the stable association of proteins within multi‐subunit complexes and the transient association of regulatory proteins. Information about protein interactions in cells has previously come from either in vitro analyses using recombinant expressed proteins, or from yeast 2–hybrid studies. A limitation of this approach is that the protein interaction is studied in isolation, without regard to the many competing protein interactions that can occur within cells. This unit presents a light microscopy approach for detecting protein‐protein interactions in vivo based on the measurement of FRET using the multiphoton fluorescence lifetime imaging microscopy (FLIM) technique. By using the FLIM‐FRET technique, the spatial organization and quantification of such interactions in a living cell can be characterized. A detailed protocol describing the complete microscope procedure and the choice of the appropriate experimental controls as well as the FRET calculations is also included. Curr. Protocol. Cytom. 42:12.10.1‐12.10.19. © 2007 by John Wiley & Sons, Inc.
Standing Wave Meters and Network Analyzers
Authors: Rolfes Ilona , Gronefeld Andreas , Schiek Burkhard
Published: October 2007

The sections in this article are

Measurement of Networks at Microwave Frequencies

Reflection Measurement Techniques

Error Models, Calibration, and Error Correction

Modern Self‐Calibration Techniques for Four‐ReceiverVNAs

Outlook and Related Topics
High‐Frequency Underwater Sound
Authors: Dahl Peter H.
Published: October 2007

This article will focus on some applications ofhigh‐frequencysound to probe the underwater environment. We define high‐frequency somewhat broadly, meaning frequencies of order 104 Hz (10 kHz) up to about 107 Hz (10 MHz). The nominal upper frequency limit is chosen from the applications point of view.
Fullerene Polymers: Synthetic Strategies, Properties and Applications
Authors: Giacalone Francesco , Martín Nazario
Published: October 2007

A general overview of the different C60‐containing polymers according to their chemical structure and the general synthetic routes followed for their preparation as well as their potential applications is presented. The many fullerene‐containing polymers reported in the recent literature have been classified depending upon the position of the fullerenes within the polymer chain and considering the type of chemical connectivity between them.

The combination of fullerenes and polymer chemistry is a new interdisciplinary field in which all the knowledge on the synthesis and study of natural, as well as artificial macromolecules, can be applied to fullerenes to achieve novel fullerene‐based architectures. The combination of the unique properties of C60with the characteristics of well‐known polymers, often allow chemists to create new materials with combined features. In some cases, novel unprecedented properties open the doors to new realistic applications.

In this article, a general overview of the different types of C60‐containing polymers according to their chemical structure and the consideration of their general synthetic routes as well as their plausible applications is given.

The aim of this work is to establish a classification of the many fullerene‐containing polymers reported in the literature in order to clarify the field for all those chemists interested in the topic. Nevertheless to say that not all the examples known are covered, but those more representative or appealing for the authors. For a more comprehensive presentation the readers are referred to a recent review on the same topic.
Fundamentals of Atom Transfer Radical Polymerization
Authors: Golas Patricia L. , Mueller Laura A. , Matyjaszewski Krzysztof
Published: October 2007

The development of living polymerization enabled the production of polymers with precisely controlled molecular weight, narrow molecular weight distribution, and well‐defined architecture and composition. There are a number of advantages of controlled/living radical polymerization (CRP) as compared to ionic polymerization. Such advantages include applicability to a wide range of monomers and solvents, tolerance to impurities and functional groups, and ease of experimental set‐up. The most widely used CRP techniques include atom transfer radical polymerization (ATRP), nitroxide‐mediated polymerization, organometallic‐mediated radical polymerization, and degenerative transfer polymerization. In each case, control is maintained via fast dynamic equilibrium between dormant species and propagating chains. This article gives details on ATRP fundamentals, mechanistic considerations, conducting ATRP, materials, and functionality. Recent advances in catalyst design, initiation systems, and material synthesis have expanded the potential of ATRP as an environmentally benign process.
Isolation of Human Embryonic Stem Cell–Derived Teratomas for the Assessment of Pluripotency
Authors: Gertow Karin , Przyborski Stefan , Loring Jeanne F. , Auerbach Jonathan M. , Epifano Olga , Otonkoski Timo , Damjanov Ivan , Ährlund‐Richter Lars
Published: October 2007

This unit describes protocols on how to assess the developmental potency of human embryonic stem cells (hESCs) by performing xenografting into immunodeficient mice to induce teratoma formation. hESCs can be injected under the testis capsule, or alternatively into the kidney or subcutaneously. Teratomas that develop from grafted hESCs are surgically removed, fixed in formaldehyde, and paraffin embedded. The tissues in the teratoma are analyzed histologically to determine whether the hESCs are pluripotent and form tissues derived from of all three embryonic germ layers (ectoderm, mesoderm, and endoderm). Teratomas can also be fixed in Bouin's or cryosectioned for analysis, and they can be analyzed by immunohistochemistry for tissue markers. Methods for these procedures are included in this unit. Curr. Protoc. Stem Cell Biol. 3:1B.4.1‐1B.4.29. © 2007 by John Wiley & Sons, Inc.
Formation and Hematopoietic Differentiation of Human Embryoid Bodies by Suspension and Hanging Drop Cultures
Authors: Cerdan Chantal , Hong Seok Ho , Bhatia Mickie
Published: October 2007

The in vitro aggregation of human embryonic stem cells (hESCs) into clusters termed embryoid bodies (EBs) allows for the spontaneous differentiation of cells representing endoderm, mesoderm, and ectoderm lineages. This stochastic process results however, in the generation of low numbers of differentiated cells, and can be enhanced to some extent by the addition of exogenous growth factors or overexpression of regulatory genes. In the authors' laboratory, the use of hematopoietic cytokines in combination with the mesoderm inducer bone morphogenetic protein‐4 (BMP‐4) was able to generate up to 90% of CD45+ hematopoietic cells with colony‐forming unit (CFU) activity. This unit describes two protocols that have been successfully applied in the authors' laboratory for the generation of EBs in (1) suspension and (2) hanging drop (HD) cultures from enzymatically digested clumps of undifferentiated hESC colonies. Curr. Protoc. Stem Cell Biol. 3:1D.2.1‐1D.2.16. © 2007 by John Wiley & Sons, Inc.
Simple Route to Hydrophilic Microfluidic Chip Fabrication Using an Ultraviolet (UV)‐Cured Polymer
Authors: Kim S. H. , Yang Y. , Kim M. , Nam S.‐W. , Lee K.‐M. , Lee N. Y. , Kim Y. S. , Park S.
Published: October 2007

Herein, we introduce a simple route to fabricating hydrophilic microfluidic chips with an alternative material, a UV‐cured polyurethane‐related polymer, known as Norland Optical Adhesive (NOA 63). Conventionally, polydimethylsiloxane (PDMS) is widely used to fabricate microfluidic chips as an alternative to glass or SiO2 because PDMS is easily molded and relatively cheap. However, despite these advantages, the hydrophobicity of PDMS entails critical problems when it is used in microfluidic chips because microchannels inside the microfluidic chips, which have extremely low surface tension, are difficult to fill with aqueous solution without an extra pumping system. To overcome these problems, significant efforts have been focused on developing procedures to change the PDMS surface to be hydrophilic. However, the resulting hydrophilicity is generally short‐lived and the modification procedures require cumbersome multi‐steps. In the present study, we demonstrate that microchannel‐molding and microfluidic chip construction are easier using NOA 63 than when using PDMS and that the hydrophilicity of the NOA surface, which is induced by treatment with O2 plasma, lasts longer, for at least one month. Due to the longer lasting hydrophilicity, microchannels in NOA 63 microfluidic chips are spontaneously filled with solution by capillary reaction without any extra pumping over the period. The feasibility of NOA 63‐based microfabrication is verified by demonstrating NOA 63 microfluidic platforms with antibody‐immobilized beads for immunoassays.
Poly(vinyl alcohol) Scaffolds with Tailored Morphologies for Drug Delivery and Controlled Release
Authors: Gutiérrez M. C. , García‐Carvajal Z. Y. , Jobbágy M. , Rubio F. , Yuste L. , Rojo F. , Ferrer M. L. , del Monte F.
Published: October 2007

Poly(vinyl alcohol) (PVA) scaffolds are prepared by a cryogenic process that consists of the unidirectional freezing of a PVA solution. The scaffolds exhibit a microchanneled structure, the morphology of which (in terms of pore diameter, surface area, and thickness of matter accumulated between adjacent microchannels) can be finely tailored by the averaged molecular weight of PVA, the PVA concentration in the solution, and the freezing rate of the PVA solution. The resulting PVA scaffolds are suitable substrates for drug‐delivery purposes, the drug release being controlled (from tens of minutes up to several days) by the morphology of the microchanneled structure. In vitro experiments reveal the efficiency of PVA scaffolds for controlling the release of ciprofloxacin into a bacteria culture medium.
Thickness‐Dependent Structural Evolutions and Growth Models in Relation to Carrier Transport Properties in Polycrystalline Pentacene Thin Films
Authors: Cheng H.‐L. , Mai Y.‐S. , Chou W.‐Y. , Chang L.‐R. , Liang X.‐W.
Published: October 2007

Thickness‐dependent crystal structure, surface morphology, surface energy, and molecular structure and microstructure of a series of polycrystalline pentacene films with different film thickness ranging from several monolayers to the several hundred nanometers have been investigated using X‐ray diffraction (XRD), atomic force microscopy (AFM), contact angle meter, and Raman spectroscopy. XRD studies indicate that thin film polymorphs transformation behaviours are from the orthorhombic phase to the thin‐film phase and then to the triclinic bulk phase as measured by the increased tilt angle (θtilt) of the pentacene molecule from the c‐axis toward the a‐axis. We propose a growth model that rationalizes the θtilt increased along with increasing film thickness in terms of grain size and surface energy varying with film growth using AFM combined with contact angle measurements. The vibrational characterizations of pentacene molecules in different thickness films were investigated by Raman spectroscopy compared to density functional theory calculations of an isolated molecule. In combination with XRD and AFM the method enables us to distinguish the molecular microstructures in different thin film polymorphs. We proposed a methodology to probe the microscopic parameters determining the carrier transport properties based on Davydov splitting and the characteristics of aromatic C–C stretching modes in Raman spectra. When compared to the triclinic bulk phase at a high thickness, we suggest that the first few monolayer structures located at the dielectric surface could have inferior carrier transport properties due to weak intermolecular interactions, large molecular relaxation energy, and more grain boundaries.
Tuning the Emitting Color of Organic Light‐Emitting Diodes Through Photochemically Induced Transformations: Towards Single‐Layer, Patterned, Full‐Color Displays and White‐Lighting Applications
Authors: Vasilopoulou M. , Georgiadou D. , Pistolis G. , Argitis P.
Published: October 2007

Photochemically induced emission tuning for the definition of pixels emitting the three primary colors, red, green, blue (RGB), in a single conducting polymeric layer is investigated. The approach proposed is based on an acid‐induced emission shift of the (1‐[4‐(dimethylamino)phenyl]‐6‐phenylhexatriene) (DMA‐DPH) green emitter and acid‐induced quenching of the red fluorescent emitter (4‐dimethylamino‐4′‐nitrostilbene) (DANS). The two emitters are dispersed in the wide bandgap conducting polymer poly(9‐vinylcarbazole) (PVK), along with a photoacid generator (PAG). In the unexposed film areas, red emission is observed because of efficient energy transfer from PVK and DMA‐DPH to DANS. Exposure of selected areas of the film at different doses results in quenching of the red emitter's fluorescence and the formation of green, blue, or even other color‐emitting pixels, depending on the exposure dose and the relative concentrations of the different compounds in the film. Organic light‐emitting diodes having the PVK polymer containing the appropriate amounts of DMA‐DPH, DANS, and PAG as the emitting layer are fabricated and electroluminescence spectra are recorded. The time stability of induced emission spectrum changes and the color stability during device operation are also examined, and the first encouraging results are obtained.
A Europium Complex With Excellent Two‐Photon‐Sensitized Luminescence Properties
Authors: Hao R. , Li M. , Wang Y. , Zhang J. , Ma Y. , Fu L. , Wen X. , Wu Y. , Ai X. , Zhang S. , Wei Y.
Published: October 2007

We report the synthesis and excellent two‐photon‐sensitized luminescence properties of a new complex [Eu(tta)3dmbpt] (tta = henoyltrifluoroacetonate; dmbpt = 2‐(N,N‐diethyl‐2,6‐dimethylanilin‐4‐yl)‐4,6‐bis(3,5‐dimethylpyrazol‐1‐yl)‐1,3,5‐triazine) that exhibits the highest efficiency of lanthanide luminescence when excited by near‐infrared (NIR) laser pulses (action cross section of two‐photon‐excited fluorescence δ × ΦF: 85 GM at 812 nm and 56 GM at 842 nm; 1 GM = 10–50 cm4 s photon–1 molecule–1). Compared to a previously reported [Eu(tta)3dpbt] complex, (dpbt = 2‐(N,N‐diethylanilin‐4‐yl)‐4,6‐bis(3,5‐dimethylpyrazol‐1‐yl)‐1,3,5‐triazine), [Eu(tta)3dmbpt] has two excess methyl groups at the 2,6‐positions of the phenyl ring. Crystallographic data of dmbpt show that the 2,6‐dimethyl substitutes bring about a significant twist in the conformation of the diethylamino group compared to that in dpbt, which severely influences the conjugation in the ground state between the electron lone pair of N in the –N(CH2–)2 moiety and the aromatic electron system in dmbpt. The large two‐photon absorption (TPA) cross section of dmbpt is mainly derived from its large static dipole moment difference between the S0 and the S1 states, which is partly responsible for the high capability of two‐photon‐sensitized luminescence of [Eu(tta)3dmbpt]. The broader two‐ and single‐photon excitation windows and the superior two‐photon‐sensitized luminescent properties in the long‐wavelength NIR region of [Eu(tta)3dmbpt] compared to [Eu(tta)3dpbt] are also explained according to the calculated results and twisted structure.
All‐Optical Operation Cycle on Molecular Bits with 250‐GHz Clock‐Rate Based on Photochromic Fulgides
Authors: Malkmus S. , Koller F. O. , Draxler S. , Schrader T. E. , Schreier W. J. , Brust T. , DiGirolamo J. A. , Lees W. J. , Zinth W. , Braun M.
Published: October 2007

The prototype operation of an ultrafast write–readout–erase–readout cycle of an all‐optical system based on photochromic indolylfulgides is demonstrated. In the employed dye the molecular structure is switched using light of different wavelengths between two thermally stable states to allow binary encoding of information. Non‐destructive readout of the bit states using infrared light completes the scheme of an all‐optical memory. For ultrafast operation femtosecond light pulses are applied and it is demonstrated that two consecutive write/erase processes separated by less than 4 ps still allow the defined readout of the bit state. The short time between the write/erase and readout actions demonstrates that an all‐optical data storage system based on indolylfulgides may be operated at memory clock rates that exceed 250 GHz.
Increasing the Complexity of Magnetic Core/Shell Structured Nanocomposites for Biological Applications
Authors: Salgueiriño‐Maceira V. , Correa‐Duarte M. A.
Published: October 2007

This Review article ponders core/shell structured nanoparticles that can be prepared with features that combine properties of different materials, including ligands that enhance their biocompatibility. These nanocomposites are not classified in terms of synthesis, but rather by how these features are distributed in the final morphology, attending to connected or isolated materials that end up in interacting or not‐interacting functionalities. In particular, we have focused on magnetic core/shell‐structured particles with a directly connected, coupled, or isolated second functionality. The current progress on methods in colloidal solution that have allowed the great development of these multifunctional magnetic and active spheres on biological and biomedical fields is reported.
Peeling Back the Layers: Controlled Erosion and Triggered Disassembly of Multilayered Polyelectrolyte Thin Films
Authors: Lynn D. M.
Published: October 2007

Methods for the layer‐by‐layer deposition of oppositely charged polymers on surfaces can be used to assemble thin multilayered films using a broad range of natural, synthetic, and biologically relevant materials. These methods also permit precise, nanometer‐scale control over the compositions and internal structures of multicomponent assemblies. Provided that the individual components of these materials are selected or designed appropriately, these methods provide tantalizing new opportunities to design thin films and coatings that provide spatial, temporal, or active control over the release of one or several different agents from surfaces. The last two years have seen a significant increase in reports describing the development of new chemical, physical, and biomolecular approaches to the controlled erosion, triggered disassembly, or general deconstruction of multilayered polymer films. In this Progress Report, we highlight recent work from our laboratory and several other groups toward the design of ultrathin multilayered assemblies that i) permit broad, tunable, and sophisticated control over film erosion, and ii) provide new opportunities for the localized release of macromolecular therapeutics, such as DNA and proteins, from surfaces.
Amelioration of antigen‐induced arthritis in rabbits treated with monoclonal antibodies to leukocyte adhesion molecules
Authors: Jasin Hugo E. , Lightfoot Ellis , Davis Laurie S. , Rothlein Robert , Faanes Ronald B. , Lipsky Peter E.
Published: October 2007

Objective. To examine the effects of treatment of antigen‐induced arthritis in rabbits with a monoclonal antibody against CD18, the common β chain of the leukocyte adhesion molecules. Intraarticular injection of antigen into primed rabbits elicits an acute inflammatory response followed by chronic arthritis in this model.

Methods. Anti‐CD18 was given at the time of intraarticular antigen administration, and effects on the acute and chronic arthritis were investigated. Twentyfour rabbits were examined (11 controls, 3 receiving normal mouse IgG, and 10 receiving anti‐CD18).

Results. Flow cytometry of blood leukocytes at anti‐CD18 administration showed saturating amounts of mouse Ig coating all the circulating cells. Treatment effects on the acute arthritis (measured by quantitating the synovial cell exudate 24 hours after arthritis induction) were a profound reduction in the number of inflammatory cells and a striking decrease in the proportion of polymorphonuclear leukocytes recovered from the synovial cavity, indicating a decrease in acute inflammation. Treatment effects on the chronic synovitis (2 and 4 weeks later) compared with controls showed a significant decrease in synovial fluid cell counts at 2 weeks (1.7 versus 21.0 x 1066/joint, P < 0.03) and at 4 weeks (7.4 versus 22.6 x 106/joint, P < 0.05). Histologic evaluation of the synovium (0–3+ scale, scored ‘blindly’) of anti‐CD18–treated rabbits and controls showed marked decreases in subsynovial cell infiltration and lymphoid follicle formation both at 2 weeks (1.0 versus 2.25, P < 0.005; and 0 versus 1.75, P < 0.001) and at 4 weeks (1.48 versus 2.17, P < 0.01; and 0.75 versus 2.08, P < 0.02). Quantitation of cartilage‐bound immune complexes, and of synovial synthesis of Ig and specific antibody showed no differences between groups.

Conclusion. These findings indicate that treatment with monoclonal antibody to CD18 not only modifies the initial acute arthritis, but also results in significant amelioration of the subsequent chronic inflammation in this animal model of rheumatoid arthritis.
Synthesis of Oligo(thienylfuran)s with Thiophene Rings at Both Ends and Their Structural, Electronic, and Field‐Effect Properties
Authors: Miyata Yasuo , Terayama Miki , Minari Takeo , Nishinaga Tohru , Nemoto Takashi , Isoda Seiji , Komatsu Koichi
Published: October 2007

Oligo(thienylfuran)s with thiophene rings at both ends (SOSOSOS, DE‐SOSOS, DH‐SOSOS, DE‐SOSOSOS, and DH‐SOSOSOS; S and O denote thiophene and furan rings, respectively, DE and DH denote diethyl‐ and dihexyl‐substituted, respectively) were newly synthesized by repetitive Stille coupling reactions. The UV/Vis maximum absorptions of the oligomers, SO, SOSO, SOSOS, SOSOSO, and SOSOSOS, exhibited a clear bathochromic shift with increasing number of heterocycles. The value of the oxidation peak potential (Epa1) determined by cyclic voltammetry decreased with an increase in the number of heterocycles by 0.06–0.08 V per heterocycle. The crystal‐packing structures of DE‐SOSOS and DH‐SOSOS determined by X‐ray crystallography have a herringbone motif and are denser than the reported structures of pentacene and α‐sexithiophene. The morphologies of thin films prepared by vacuum deposition and spin coating were investigated by atomic force microscopy and X‐ray diffraction. Among these films, those of DE‐SOSOS and DH‐SOSOS exhibited highly ordered arrangements. The devices based on vacuum‐deposited and spin‐coated films of DE‐SOSOS and DH‐SOSOS displayed the highest FET mobilities of 10−2–10−3 cm2 V−1 s−1 among the oligomers reported in this study.
Crops for industrial use ‐ a surge of interest
Authors: Lillford Peter J.
Published: October 2007

At this stage, the demand is for information rather than dramatic innovation. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd
Ecology of scale versus economy of scale for bioethanol production
Authors: Gwehenberger Gernot , Narodoslawsky Michael , Liebmann Bettina , Friedl Anton
Published: October 2007

Sustainability is an essential requirement of biofuel production. The reduction of ecological impact by using renewable resources instead of fossil raw materials is a major driving force for biofuel implementation. The investigation of ethanol production systems on different scales utilizing corn as well as wheat as raw material reveals, however, a strong influence of the size of the plant on the environmental pressure exerted by biofuel production. Comparing different technological options at different levels of production capacity gives insights into the major factors governing ecological as well as economical performance.

The trend with regard to economic performance is straightforward and well known: the higher the production capacity of a plant, the lower the costs. The picture is less clear with regard to ecological performance. Increased efficiency of larger plants usually reduces not only the costs but also the ecological impacts. Logistical factors, however, become increasingly important, leading to situations where economy of scale and ecology of scale are in contradiction. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd.
Paper‐PEG‐based membranes for hydrophobic interaction chromatography: Purification of monoclonal antibody
Authors: Yu Deqiang , Chen Xiaonong , Pelton Robert , Ghosh Raja
Published: October 2007

This article discusses the preparation of novel Paper‐PEG interpenetrating polymer network‐based membranes as inexpensive alternative to currently available adsorptive membranes. The Paper‐PEG membranes were developed for carrying out hydrophobic interaction membrane chromatography (HIMC). PEG is normally very hydrophilic but can undergo phase separation and become hydrophobic in the presence of high antichaotropic salt concentrations. Two variants of the Paper‐PEG membranes, Paper‐PEG 1 and Paper‐PEG 2 were prepared by grafting different amounts of the polymer on filter paper and these were tested for their hydraulic properties and antibody binding capacity. The better of the two membranes (Paper‐PEG 1) was then used for purifying the monoclonal antibody hIgG1‐CD4 from simulated mammalian cell culture supernatant. The processing conditions required for purification were systematically optimized. The dynamic antibody binding capacity of the Paper‐PEG 1 membrane was about 9 mg/mL of bed volume. A single step membrane chromatographic process using Paper‐PEG 1 membrane gave high monoclonal antibody purity and recovery. The hydraulic permeability of the paper‐based membrane was high and was maintained even after many runs, indicating that membrane fouling was negligible and the membrane was largely incompressible. Biotechnol. Bioeng. 2008;99: 1434–1442. © 2007 Wiley Periodicals, Inc.
Analysis of ammonia loss mechanisms in microbial fuel cells treating animal wastewater
Authors: Kim Jung Rae , Zuo Yi , Regan John M. , Logan Bruce E.
Published: October 2007

Ammonia losses during swine wastewater treatment were examined using single‐ and two‐chambered microbial fuel cells (MFCs). Ammonia removal was 60% over 5 days for a single‐chamber MFC with the cathode exposed to air (air–cathode), versus 69% over 13 days from the anode chamber in a two‐chamber MFC with a ferricyanide catholyte. In both types of systems, ammonia losses were accelerated with electricity generation. For the air–cathode system, our results suggest that nitrogen losses during electricity generation were increased due to ammonia volatilization with conversion of ammonium ion to the more volatile ammonia species as a result of an elevated pH near the cathode (where protons are consumed). This loss mechanism was supported by abiotic tests (applied voltage of 1.1 V). In a two‐chamber MFC, nitrogen losses were primarily due to ammonium ion diffusion through the membrane connecting the anode and cathode chambers. This loss was higher with electricity generation as the rate of ammonium transport was increased by charge transfer across the membrane. Ammonia was not found to be used as a substrate for electricity generation, as intermittent ammonia injections did not produce power. The ammonia‐oxidizing bacterium Nitrosomonas europaea was found on the cathode electrode of the single‐chamber system, supporting evidence of biological nitrification, but anaerobic ammonia‐oxidizing bacteria were not detected by molecular analyses. It is concluded that ammonia losses from the anode chamber were driven primarily by physical–chemical factors that are increased with electricity generation, although some losses may occur through biological nitrification and denitrification. Biotechnol. Bioeng. 2008;99: 1120–1127. © 2007 Wiley Periodicals, Inc.
Combining metabolic engineering and metabolic evolution to develop nonrecombinant strains of Escherichia coli C that produce succinate and malate
Authors: Jantama Kaemwich , Haupt M.J. , Svoronos Spyros A. , Zhang Xueli , Moore J.C. , Shanmugam K.T. , Ingram L.O.
Published: October 2007

Derivatives of Escherichia coli C were engineered to produce primarily succinate or malate in mineral salts media using simple fermentations (anaerobic stirred batch with pH control) without the addition of plasmids or foreign genes. This was done by a combination of gene deletions (genetic engineering) and metabolic evolution with over 2,000 generations of growth‐based selection. After deletion of the central anaerobic fermentation genes (ldhA, adhE, ackA), the pathway for malate and succinate production remained as the primary route for the regeneration of NAD+. Under anaerobic conditions, ATP production for growth was obligately coupled to malate dehydrogenase and fumarate reductase by the requirement for NADH oxidation. Selecting strains for improved growth co‐selected increased production of these dicarboxylic acids. Additional deletions were introduced as further improvements (focA, pflB, poxB, mgsA). The best succinate biocatalysts, strains KJ060(ldhA, adhE, ackA, focA, pflB) and KJ073(ldhA, adhE, ackA, focA, pflB, mgsA, poxB), produce 622–733 mM of succinate with molar yields of 1.2–1.6 per mole of metabolized glucose. The best malate biocatalyst, strain KJ071(ldhA, adhE, ackA, focA, pflB, mgsA), produced 516 mM malate with molar yields of 1.4 per mole of glucose metabolized. Biotechnol. Bioeng. 2008;99: 1140–1153. © 2007 Wiley Periodicals, Inc.
Model‐based comparative performance analysis of membrane aerated biofilm reactor configurations
Authors: Syron Eoin , Casey Eoin
Published: October 2007

The potential of the membrane aerated biofilm reactor (MABR) for high‐rate bio‐oxidation was investigated. A reaction‐diffusion model was combined with a preliminary hollow‐fiber MABR process model to investigate reaction rate‐limiting regime and to perform comparative analysis on prospective designs and operational parameters. High oxidation fluxes can be attained in the MABR if the intra‐membrane oxygen pressure is sufficiently high, however the volumetric oxidation rate is highly dependent on the membrane specific surface area and therefore the maximum performance, in volumetric terms, was achieved in MABRs with relatively thin fibers. The results show that unless the carbon substrate concentration is particularly high, there does not appear to be an advantage to be gained by designing MABRs on the basis of thick biofilms even if oxygen limitations can be overcome. Biotechnol. Bioeng. 2008;99: 1361–1373. © 2007 Wiley Periodicals, Inc.
Metabolic uncoupling of Shewanella oneidensis MR‐1, under the influence of excess substrate and 3, 3′, 4′, 5‐tetrachlorosalicylanilide (TCS)
Authors: Saini Gaurav , Wood Brian D.
Published: October 2007

The dissociation between catabolism and anabolism is generally termed as metabolic uncoupling. Experimentally, metabolic uncoupling is characterized by a reduction in the observed biomass yield. This condition can be brought about by: (a) excess‐substrate (as measured by S0/X0), and (b) addition of chemical uncouplers such as 3, 3′, 4′, 5‐Tetrachlorosalicylanilide (TCS). An empirical model is proposed to quantify the uncoupling effects of both excess‐substrate and uncoupler addition on the microbial cultures. Metabolic uncoupling of Shewanella oneidensis MR‐1, under the influence of excess pyruvate and TCS, has been modeled using the proposed expression. The degree of uncoupling was measured as a fractional reduction in theoretical maximum observed yield. Excess‐substrate was observed to successively reduce biomass yield as substrate concentration was increased. In the presence of TCS, conflicting trends were obtained for number yield and protein yield. This could, in part, be attributed to the observed increase in cellular protein content upon addition of TCS. Excess‐substrate conditions dominated uncoupling, as compared to uncoupler addition. However, these two approaches were found to have additive effects and could, in conjunction, be employed to control biomass growth during microbial processes such as subsurface bioremediation and activated sludge treatment. Biotechnol. Bioeng. 2008;99: 1352–1360. © 2007 Wiley Periodicals, Inc.
Choosing strategic responses to address emerging environmental regulations: size, perceived influence and uncertainty
Authors: Clemens Bruce , Bamford Charles E. , Douglas Thomas J.
Published: October 2007

How companies respond to impending regulations is a significant aspect of corporate strategy. Regulations, especially environmental regulations, are expanding quickly and increasingly important to firm success. The threat of impending environmental regulation forces companies to choose levels of strategic responses on a continuum from passive to active. Using practitioner oriented research and existing theoretical models of corporate response, this study finds that the type of strategic response is negatively related to size, positively related to state uncertainty and negatively related to effect/response uncertainty. Based on existing literature and the results of this study, the paper suggests that simplifying the uncertainty construct could lead to more definitive findings in future research. The study results also suggest that a curvilinear relationship may exist between managerial perception of influence and level of strategic response.

Most importantly, the findings could have a significant impact on firm decision making regarding environmental investments. For example, it is hoped that firms will be able to use the findings of this study to further understand and anticipate their competitors' decisions. Practitioners may also benefit from the conclusions on uncertainty in that they may be able to more cleanly parse the types of uncertainty immersed in impending environmental regulations. Finally, firms may be better able to understand decisions by their own managers and their competitors' managers in terms of their perceived influence over the regulatory process. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
The natural environment as a primary stakeholder: the case of climate change
Authors: Haigh Nardia , Griffiths Andrew
Published: October 2007

In this paper, we review the debate surrounding whether or not the natural environment should be considered an organizational stakeholder. We argue for a broad definition of stakeholders, and present a case for the natural environment being an easily identifiable primary stakeholder when climate change is brought into the debate. We develop a conceptual stakeholder identification framework by combining and extending the work of Mitchell, Agle and Wood, and Driscoll and Starik. We approach the stakeholder issue from a strategic rather than moral or ethical perspective. In particular, we contend that power, legitimacy, urgency and proximity are combined when climatic changes, such as increasingly frequent anomalous extreme weather, can damage business infrastructure, resources, products and market, overshadowing moral and ethical aspects of the debate. We also identify key implications for business and policymakers, and highlight opportunities for future research. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
An assessment and ranking of barriers to doing environmental business with China
Authors: Guerin Turlough F.
Published: October 2007

The transfer of environmental goods and services to China will increasingly be of importance to developed nations as the demand for environmental management services increases in China. A review of the literature on technology transfer to China revealed a range of well recognized and commonly known constraints to transferring technologies to China. There were gaps in the literature in relation to the concerns that environmental professionals have regarding technology transfer to China, as there is limited information on the transfer in environmental goods and services to China. A survey of the non‐trade barriers and their practical impact on the transfer of environmental technologies and goods and services to China, focusing on Australian suppliers, was undertaken to address these gaps. The survey, which was developed from barriers to technology transfer already described in the extensive research addressing the wider issues of technology transfer to China, targeted environmental professionals but also included other professionals with interests in transferring environmental goods and services to China. From the survey, the highest priority barriers to transferring environmental goods and service to China were identified, and those that are most likely to limit Australian vendors of environmental goods and services in their technology transfers to China were protection of intellectual property (IP), limitations of the rule of law, fragmentation and bureaucracy of the Chinese government and establishing appropriate level of ownership (of environmental goods and services providers in China). Examples of Australian experience were also examined, which confirmed these barriers to providing the needed technology and innovation to manage China's increasing environmental impacts. The research also shows that the barriers identified do not appear to be unique to transfer of environmental goods and services but rather generic to the transfer and adoption of Australian technology into China. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
Solution‐State 15N NMR Spectroscopic Study of α‐C‐Phycocyanin: Implications for the Structure of the Chromophore‐Binding Pocket of the Cyanobacterial Phytochrome Cph1
Authors: Hahn Janina , Kühne Ronald , Schmieder Peter
Published: October 2007

The detailed structure of the chromophore‐binding pocket in phytochrome proteins and the structural changes associated with its photocycle are still matters of debate. Insight into the structure and dynamics of the binding pocket has been gained through the comparison of a 15N NMR spectrum of α‐C‐phycocyanin, which is often used as a model system for the study of phytochromes, with the previously described 15N NMR spectrum of the cyanobacterial phytochrome Cph1. The former spectrum supports the hypothesis that all four nitrogen atoms of the α‐C‐phycocyanin chromophore are protonated, in analogy with the proposed protonation state for the Pr and Pfr forms of Cph1. The spectra show that the chromophores in both proteins exhibit a distinct dynamic behavior, as also indicated by a NOESY spectrum of Cph1. Finally, stereochemical arguments and a Cph1 homology model support the hypothesis that the chromophore in Cph1 is most likely in the ZZZssa conformation in the Pr form of the protein.
Characterization of a Putative Phosphorylation Switch: Adaptation of SPOT Synthesis to Analyze PDZ Domain Regulation Mechanisms
Authors: Boisguerin Prisca , Ay Bernhard , Radziwill Gerald , Fritz Rafael D. , Moelling Karin , Volkmer Rudolf
Published: October 2007

Transient macromolecular complexes are often formed by protein–protein interaction domains (e.g., PDZ, SH2, SH3, WW), which are often regulated (positively or negatively) by phosphorylation. To address the in vitro analysis of PDZ domain regulation by such phosphorylation, we improved the inverted peptide method. This method is based on standard SPOT synthesis, followed by inversion of the peptide under acidic conditions to generate the free C termini necessary for PDZ domain ligand recognition. The benefit of the newly introduced acidic conditions is the preservation of the incorporated phosphate group during peptide synthesis. Furthermore, the improved method is more robust and shows an increased signal‐to‐noise ratio. As representative examples, we used the AF6, ERBIN, and SNA1 (α‐1‐syntrophin) PDZ domains to analyze the influence of ligand‐position‐dependent phosphorylation. We could clearly demonstrate severe down‐regulation by phosphorylation of the PDZ ligand position −2 (<50 %) and slightly less at position −1 (∼50 %). These results are specific and reproducible for all three PDZ domains. Finally, we confirmed the influence of negative regulation by using the protein kinase BCR as the AF6 PDZ domain ligand. For the first time, this approach allows the SPOT synthesis technique to be used to screen large libraries of phosphorylated peptides in vitro. This should ultimately help in the identification of phosphorylation‐dependent regulation mechanisms in vivo.
Energetics and Mechanism of Ammonia Synthesis through the Chatt Cycle: Conditions for a Catalytic Mode and Comparison with the Schrock Cycle
Authors: Stephan Gerald C. , Sivasankar Chinnappan , Studt Felix , Tuczek Felix
Published: October 2007

Through a series of DFT calculations the energy profile of the Chatt cycle is evaluated. This is the counterpiece of our earlier investigations of the Schrock cycle (Angew. Chem. 2005, 117, 5783; Angew. Chem. Int. Ed. 2005, 44, 5639), applying the same quantumchemical methodology and approximations. As for the Schrock cycle, decamethylchromocene acts as reductant. The protonation reactions are considered to be mediated by HBF4/diethyl ether or lutidinium. For all protonation and reduction steps the corresponding free reaction enthalpy changes are calculated. The derived energy profile and corresponding reaction mechanism bear strong similarities to the Schrock cycle. In particular, the most endergonic reaction is the first protonation of the N2 complex and the most exergonic reaction is the cleavage of the NN bond. If lutidinium is employed as acid and ${{\rm Cp}{{{\ast}\hfill \atop 2\hfill}}}$Cr as reductant, the reaction course involves steps that are not thermally allowed. For HBF4/diethyl ether as the acid and ${{\rm Cp}{{{\ast}\hfill \atop 2\hfill}}}$Cr as reducant, however, a catalytic cycle consisting of thermally allowed reactions is principally feasible. This cycle involves a MoI–fluoro complex as dinitrogen intermediate. It is shown that regeneration to the Mo0–bis(dinitrogen) complex is thermally not accessible in this system. Moreover, the MoI fluoro‐dinitrogen complex is labile towards disproportionation. The implications of these results with respect to the realization of a catalytic system on the basis of Mo and W phosphine complexes are discussed.
Total Syntheses of Carbohydrates: Organocatalyzed Aldol Additions of Dihydroxyacetone
Authors: Markert Morris , Mahrwald Rainer
Published: October 2007

The selective total synthesis of carbohydrates with defined configuration has been of great interest for a long time. This field has been the domain of enzymatic methods so far. But now the recent development of several organocatalyzed aldol methodologies has made a selective synthetic approach to configuratively defined carbohydrates possible. This development and different strategies will be discussed in this concept article.
Charge‐Transfer Complexes Between the Sulfur Molecules SO2, S2O, S3, SONH, and SOCl2 and the Amine Donors NH3 and NMe3 — A theoretical Study
Authors: Steudel Ralf , Steudel Yana
Published: October 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A CASPT2 Study of the Electronic Spectrum of Hexacyanoosmate(III).
Authors: Van den Heuvel Willem , Hendrickx Marc F. A. , Ceulemans Arnout
Published: October 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Crystal Structure, Thermoelectric and Magnetic Properties of the Type‐I Clathrate Solid Solutions Sn24P19.3(2)BrxI8‐x (0 ≤ x ≤ 8) and Sn24P19.3.(2)ClyI8‐y (y ≤ 0.8).
Authors: Zaikina Julia V. , Schnelle Walter , Kovnir Kirill A. , Olenev Andrei V. , Grin Yuri , Shevelkov Andrei V.
Published: October 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Syntheses and Crystal Structures of Two Pentaborates, Na3CaB5O10 and Na3MgB5O10.
Authors: Chen Xuean , Li Ming , Zuo Jianlong , Chang Xinan , Zang Hegui , Xiao Weiqiang
Published: October 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.