bluuebunny/crossref_metadata_2025 huggingface dataset:
Aquatic Animals in Toxicity Testing
Authors: Couch J. A. , Hargis W. J.
Published: December 2007

Aquatic animals provide useful models for toxicological evaluations that bridge the gap between real world and laboratory problems. Select aquatic organisms are adaptable to laboratory experimentation in areas such as acute toxicity testing and chronic sublethal risks evaluation, including such phenomena as carcinogenesis, mutagenesis, and teratogenesis. General and specific examples of how aquatic animals are useful to toxicologists, as well as theoretical bases for their use, are discussed in this paper.
The Marsupial as a Biomedical Model
Authors: Jurgelski W.
Published: December 2007

Marsupials are viviparous, placental mammals that have evolved independently from the same ancestor as the eutherian mammals, which include humans and the principal laboratory animals. As a result of this evolutionary divergence, marsupial structure and function embody alternative solutions to many of the problems of mammalian existence. This dichotomy between marsupials and eutherian species suggests the use of marsupial models to provide innovative laboratory approaches that may facilitate experimental access to specific aspects of normal and abnormal human anatomy and physiology. Those characteristics that endow marsupials with their unique but largely unexploited biomedical research potential are identified and evaluated.
Avian Models for Toxicity Testing
Authors: Hill E. F. , Hoffman D. J.
Published: December 2007

The use of birds as test models in experimental and environmental toxicology as related to health effects is reviewed, and an overview of descriptive tests routinely used in wildlife toxicology is provided. Toxicologic research on birds may be applicable to human health both directly by their use as models for mechanistic and descriptive studies and indirectly as monitors of environmental quality. Topics include the use of birds as models for study of teratogenesis and embryotoxicity, neurotoxicity, behavior, trends of environmental pollution, and for use in predictive wildlife toxicology. Uses of domestic and wild-captured birds are discussed.
Defining the Critical Phase
Authors: DeWoskin R. S. , Sadler B. M.
Published: December 2007

Quality does not mean compliance with a checklist of standards but rather “fitness for use.” Compliance with a checklist of standards will only assure quality if the standards specifically address the intended use of the final results. In the design of a quality assurance program, the emphasis is upon quality controls and monitoring schedules for those aspects of the study that significantly alter the variability of the final results and alter the variability to the extent that the final results are no longer useful. Therefore, the principal researcher in conjunction with the quality assurance staff contribute to the quality of a study by applying combined expertise in the design of specific reference standards that both address the fitness for use criterion and the more comprehensive government standards.
When Is a Teratology Study Not an Evaluation of Teratogenicity?
Authors: Johnson E. M. , Christian M. S.
Published: December 2007

The most widely used developmental toxicity safety evaluation is the Segment II protocol executed in rats and rabbits. It has come to be called the “teratology” study, even though it is not designed to produce terata and is not the optimal means for producing such, even if this should be the goal. To comply with the misstated letter of the Toxic Substances Control Act yet honor its intent to protect the conceptus from toxic insult, toxicologists are faced with terminology, definitions, and interpretations that result in unnecessary contention between the regulator and the regulated. When the developmental toxicology and teratology of the Segment II protocol are viewed in the appropriate context, the experiments provide not only a means for preventing embryo damage but also a means by which substances can be ranked according to their developmental hazard potential.
Enhancing data‐based fault isolation through nonlinear control
Authors: Ohran Benjamin J. , Peña David Muñoz de la , Christofides Panagiotis D. , Davis James F.
Published: December 2007

This work focuses on a broad class of nonlinear process systems subject to control actuator faults and disturbances and proposes a method for data‐based fault detection and isolation that explicitly takes into account the design of the feedback control law. This method allows isolating specific faults in the closed‐loop system; fault detection is done using a purely data‐based approach and fault isolation is achieved using the structure of the closed‐loop system as induced by an appropriately designed controller. This is achieved through the design of nonlinear model‐based state‐feedback control laws that decouple the dependency between certain process state variables in the closed‐loop system. In this sense, the proposed approach constitutes a departure from the available data‐based fault detection and isolation techniques which do not take advantage of the design of the feedback control law to enforce a closed‐loop system structure that enhances fault isolation. The theoretical results are demonstrated through simulations of a CSTR and a gas‐phase polyethylene reactor. © 2007 American Institute of Chemical Engineers AIChE J, 2008
Morphological population balance for modeling crystal growth in face directions
Authors: Ma Cai Y. , Wang Xue Z. , Roberts Kevin J.
Published: December 2007

A morphological (or polyhedral) population balance (PB) model is presented for modeling the dynamic size evolution of crystals grown from solution in all crystal growth directions. The morphological PB approach uses the crystal shape information for a single crystal obtained from morphology prediction, or experiment as the initial face locations, as well as face growth rates to predict the shape evolution of the crystal population. For each time instant during the crystallization process, the prediction uses its shape at the previous time moment, and the growth rate for the specific crystal habit plane. The methodology is demonstrated through a study of potash alum (KAl (SO4)2·12H2O), for which literature data is available for comparison and validation. The discretization method, method of classes, was used to convert the equations to ordinary differential form with the computational domain being discretized into small meshes. The ordinary differential equations (>1.5 million) were then solved simultaneously using the Runge‐Kutta‐Fehlbergh 4th/5th‐order solver with automatic time‐step control. The results obtained clearly demonstrate that the morphological PB model developed can predict crystal growth and surface area of individual habit faces in detail, together with crystal shape and size evolution. © 2007 American Institute of Chemical Engineers AIChE J, 2008
Synthesis and characterization of bacterial cellulose/alginate blend membranes
Authors: Phisalaphong Muenduen , Suwanmajo Thapanar , Tammarate Pramote
Published: December 2007

Bacterial cellulose and alginate in an aqueous NaOH/urea solution were used as substrate materials for the fabrication of a novel blend membrane. The blend solution was cast onto a Teflon plate, coagulated in a 5 wt % CaCl2 aqueous solution, and then treated with a 1% HCl solution. Supercritical carbon dioxide drying was then applied for the formation of a nanoporous structure. The physical properties and morphology of the regenerated bacterial cellulose and blend membranes were characterized. The blend membrane with 80% bacterial cellulose/20 wt % alginate displayed a homogeneous structure and exhibited a better water adsorption capacity and water vapor transmission rate. However, the tensile strength and elongation at break of the film with a thickness of 0.09 mm slightly decreased to 3.38 MPa and 31.60%, respectively. The average pore size of the blend membrane was 10.60 Å with a 19.50 m2/g surface area. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Modeling changes in the modulus of poly(ε‐caprolactone) due to hydrolysis and plasticization
Authors: Aitchison G. A. , Walker G. S. , Jones I. A. , Rudd C. D.
Published: December 2007

The evolution of the flexural modulus of poly(ε‐caprolactone), prepared with a tin(II) 2‐ethylhexanoate catalyst, was measured in terms of the polymer molecular weight and moisture content. Changes in the polymer molecular weight were observed, but these did not result in a loss of modulus. Fickian diffusion was used to characterize the absorption of moisture into the polymer. The maximum moisture content and moisture diffusivity constant of the polymer were determined to be 0.62% and 2.039 × 10−5 mm2/s, respectively. Reductions in the polymer modulus from 0.5 to 0.4 GPa were attributed to water plasticization. An empirical expression for the polymer modulus as a function of immersion time was developed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Adsorption of hexavalent chromium on cationic starches with different degree of crosslinking
Authors: Sidlauskiene D. , Klimaviciute R. , Zemaitaitis A.
Published: December 2007

The influence of the degree of crosslinking in the association with the degree of cationization on the adsorption of Cr(VI) by crosslinked cationic starches (CCS) was examined. The amount of adsorbed Cr(VI) depends on the preparation of CCS before adsorption experiments (dry or preswollen CCS) and has a higher value when dry CCS are used. The amount of crosslinks in CCS needed to reach the maximum effectiveness of the cationic groups of CCS in the binding of Cr(VI) depends also on the form in which CCS are used. The adsorption capacity for Cr(VI) decreases both with dry and preswollen CCS when the adsorption temperature increases. The thermodynamic parameters are calculated. The negative values of ΔG° and ΔH° indicated that the adsorption process in both cases was spontaneous and exothermic. If preswollen CCS is used, the entropy change has a positive value and indicates that the randomness of the system increases, whereas the negative value of entropy change when Cr(VI) species are adsorbed by dry CCS shows that in this case the order of the system increases like in the classical adsorption process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Study of a new titanium dual initiator for the synthesis of poly(ε‐caprolactone)‐b‐polystyrene block copolymers by the combination of coordination and nitroxide mediated polymerizations
Authors: Li Xinxin , Jeanmaire Thomas , Zerroukhi Amar
Published: December 2007

Poly ε‐caprolactone‐polystyrene block‐copolymers (PCL‐b‐PSt) were synthesized using a modified titanium catalyst as the dual initiator. Alcoholysis of Ti(OPr)4 by 4‐hydroxy 2,2,6,6 tetramethyl piperidinyl‐1‐oxyl (HO‐TEMPO) gave a bifunctional initiator Ti(OTEMPO)4. Poly ε‐caprolactone prepolymer end‐capped with the nitroxide group was first prepared by ring opening polymerization of ε‐caprolactone with this initiator at high conversion. The nitroxide‐end‐capped structure and molar mass (Mn) of the polymers were demonstrated by typical UV absorption band. This analytical technique indicates a near‐quantitative nitroxide functionality and a Mn in good agreement with size exclusion chromatography (SEC) ones. This polyester prepolymer was used to further initiate the radical polymerization with styrene and reach the block copolymers (PCL‐b‐PSt). All the prepolymers and block copolymers were characterized by SEC and NMR spectroscopy. Additionally, the preparation of star polymers bearing two kinds of arms (PCL and PSt) was envisaged and a preliminary result was given. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Structural characterization and dynamic water adsorption of electrospun polyamide6/montmorillonite nanofibers
Authors: Li Qi , Wei Qufu , Wu Ning , Cai Yibing , Gao Weidong
Published: December 2007

A facile compounding process, which combined nanocomposite process with electrospinning for preparing novel polyamide6/organic modified montmorillonite (PA6/O‐MMT) composite nanofibers, is reported. In this compounding process, the O‐MMT slurry was blended into the formic acid solution of PA6 at moderate temperatures, where the nanosized O‐MMT particles were first dispersed in N,N‐dimethyl formamide solvent homogeneously via ultrasonic mixing. Subsequently the solution via electrospinning formed nanofibers, which were collected onto aluminum foil. The O‐MMT platelets were detected to be exfoliated at nanosize level and dispersed homogeneously along the axis of the nanofibers using an electron transmission microscope. Scanning electron microscope and atomic force microscope were used to analysis the size and surface morphology of polyamide6/O‐MMT composite nanofibers. The addition of O‐MMT reduced the surface tension and viscosity of the solution, leading to the decrease in the diameter of nanofiber and the formation of rough and ridge‐shape trails on the nanofiber surface. The behavior of the dynamic water adsorption of composite nanofibers was also investigated and discussed in this article. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Novelty and topicality in interactive information retrieval
Authors: Xu Yunjie , Yin Hainan
Published: December 2007

The information science research community is characterized by a paradigm split, with a system‐centered cluster working on information retrieval (IR) algorithms and a user‐centered cluster working on user behavior. The two clusters rarely leverage each other's insight and strength. One major suggestion from user‐centered studies is to treat the relevance judgment of documents as a subjective, multidimensional, and dynamic concept rather than treating it as objective and based on topicality only. This study explores the possibility to enhance users' topicality‐based relevance judgment with subjective novelty judgment in interactive IR. A set of systems is developed which differs in the way the novelty judgment is incorporated. In particular, this study compares systems which assume that users' novelty judgment is directed to a certain subtopic area and those which assume that users' novelty judgment is undirected. This study also compares systems which assume that users judge a document based on topicality first and then novelty in a stepwise, noncompensatory fashion and those which assume that users consider topicality and novelty simultaneously and as compensatory to each other. The user study shows that systems assuming directed novelty in general have higher relevance precision, but systems assuming a stepwise judgment process and systems assuming a compensatory judgment process are not significantly different.
Capital punishment and anatomy: History and ethics of an ongoing association
Authors: Hildebrandt S.
Published: December 2007

Anatomical science has used the bodies of the executed for dissection over many centuries. As anatomy has developed into a vehicle of not only scientific but also moral and ethical education, it is important to consider the source of human bodies for dissection and the manner of their acquisition. From the thirteenth to the early seventeenth century, the bodies of the executed were the only legal source of bodies for dissection. Starting in the late seventeenth century, the bodies of unclaimed persons were also made legally available. With the developing movement to abolish the death penalty in many countries around the world and with the renunciation of the use of the bodies of the executed by the British legal system in the nineteenth century, two different practices have developed in that there are Anatomy Departments who use the bodies of the executed for dissection or research and those who do not. The history of the use of bodies of the executed in German Anatomy Departments during the National Socialist regime is an example for the insidious slide from an ethical use of human bodies in dissection to an unethical one. There are cases of contemporary use of unclaimed or donated bodies of the executed, but they are rarely well documented. The intention of this review is to initiate an ethical discourse about the use of the bodies of the executed in contemporary anatomy. Clin. Anat. 21:5–14, 2008. © 2007 Wiley‐Liss, Inc.
Tailor‐Made Fructooligosaccharides by a Combination of Substrate and Genetic Engineering
Authors: Zuccaro Alga , Götze Sven , Kneip Susanne , Dersch Petra , Seibel Jürgen
Published: December 2007

The combination of sucrose analogues as novel substrates (substrate engineering) and highly active recombinant β‐fructofuranosidase from A. niger (genetic engineering) provides a new powerful tool for the efficient preparative synthesis of tailor‐made saccharides of the important 1‐kestose and 1‐nystose type headed with different monosaccharides of interest. These novel compounds have been isolated. They did not display toxic effects or suppress cell growth in initial studies, making these new compounds potential candidates for prebiotics.
A Process Integration based Approach for the Analysis of an Evaporator System
Authors: Khanam S. , Mohanty B.
Published: December 2007

A scalable new mathematical model based on the principles of Process Integration has been developed for the analysis of multiple effect evaporator (MEE) systems. It uses the concepts of stream analysis, temperature path and internal heat exchange for the formulation of the model equations. In addition to the above concepts, the model also takes into account the variable physico‐thermal properties of steam/vapor, condensate and liquor, while simulating the MEE system. The present model consists of a set of linear equations and does not present any stability or oscillation problems during solution as is generally seen in the case of models that are based on sets of nonlinear equations. The model equations are automatically generated through a computer program and the model was run for three different liquor and flow sequences to prove its utility. The results obtained are compared with published models.
Magnetic Field, Flow Field and Inclusion Collision Growth in a Continuous Caster with EMBR
Authors: Lei H. , Xu G. , He J.
Published: December 2007

A three‐dimension mathematical model has been developed to describe the magnetic field, fluid flow and inclusion transport in a continuous caster with electromagnetic brake (EMBR). According to the model, all the governing equations can be expressed as a general differential equation, so a general numerical method was developed to solve these equations. The numerical results agree well with the experimental result. In the continuous caster, the inclusion distributions have ‘M’ shape under the nozzle and ‘W’ shape at the exit, which come from the centrifugal effect and the collision and aggregation among inclusions. The three‐dimensional static magnetic field can effectively damp local flows and affect the inclusion transport in a continuous caster. If EMBR is installed under the nozzle, it can promote the inclusion removal and the inclusion ‘M’ distribution disappears.
Study of the Effects of External and Internal Diffusion on the Propane Dehydrogenation Reaction over Pt‐Sn/Al2O3 Catalyst
Authors: Mohagheghi M. , Bakeri G. , Saeedizad M.
Published: December 2007

In the study of a reaction on a heterogeneous catalyst, external and internal mass diffusion play an important role since they can have an inherent affect on the kinetics of the reaction. Therefore, in the study of intrinsic rates of reaction, the effects of external and internal mass diffusion must be eliminated or considered prior to proper kinetic studies. In this study, the effects of external and internal mass diffusion on the propane dehydrogenation reaction over a Pt/Sn catalyst were investigated. Some experiments were performed in a laboratory scale setup and the required data was gathered. The rate of reaction was considered to be first order based on propane. External diffusion was studied using Mears' criterion and internal diffusion was investigated by the Thiele Module and the Internal Effectiveness Factor, based on experimental data.
Spray Scrubbing of Particulates with a Critical Flow Atomizer
Authors: Bandyopadhyay A. , Biswas M. N.
Published: December 2007

Wet scrubbers are gaining importance over other devices for particulate collection with the increasing stringency of pollution regulations. The scrubbing of particulates (soot and fly‐ash) in a spray tower with a two‐phase critical flow atomizer using water is reported in this article. The atomizer is capable of generating droplets with a high degree of spray uniformity. Preliminary studies reveal that the atomizer deployed in the present investigation is energetically more favorable than existing atomizers. With this atomizer, the scrubbing performances of a model spray tower are determined experimentally in terms of different operating variables. Various physical interactions with the exception of electrostatic effects are found to significantly influence the removal efficiency. The removal efficiency is found to increase with the inlet particle loading, gas flow rate and liquid to gas flow rate ratio. Experiments reveal that the present system collects finer (soot) particles (with a Sauter Mean Diameter (SMD) of 1.43 μm) more efficiently than the relatively coarse (fly‐ash) particles (SMD of 6.38 μm) under similar experimental conditions. Further investigation reveals that almost 100 % removal efficiency (zero penetration) of both soot and fly‐ash particles can be attained at a much lower QL/QG ratio of 3 m3/1000 actual cubic meters (ACM) than for the existing systems. A unique correlation is developed for predicting the performance of the spray tower in terms of various pertinent variables of the system. The predicted values agree very well with the experimental values (± 10 % deviation). A comparison of the performance of the present system with the existing systems indicates that the spray tower developed is techno‐enviro‐economically more favorable than existing systems.
Effects of Additives on the Activity and Enantioselectivity of Candida rugosa Lipase in a Biphasic Medium
Authors: Salgın S. , Takaç S.
Published: December 2007

The effects of Li+, Na+, K+, Mg2+ and Zn2+ ions on the activity and enantioselectivity of Candida rugosa lipase (CRL) were investigated in a biphasic medium composed of phosphate buffer solution (containing a metal ion within a 50–500 mM concentration range) and isooctane. The hydrolytic activities of CRL towards p‐nitrophenyl acetate were measured after incubation of the enzyme in the presence of metal ions for 24 h, and they were compared to that obtained after incubation in the absence of any metal ion. The CRL activity was stimulated by the chloride salts of Li+, K+ and Mg2+ for all concentrations considered and the highest enhancement was achieved by Li+ with a 1.24–1.75 fold increase observed. The effects of metal ions on the enantioselectivity of CRL were investigated by performing the hydrolysis of racemic Naproxen methyl ester in the same biphasic medium containing Li+, Na+, K+, Mg2+ and Zn2+ ions. The addition of metal ions increased the hydrolysis rate by ca. 1.31–1.45 fold relative to the control, whereas the enantiomeric excess of product increased slightly in the presence of the metal ions. The effect of Triton X‐100 on the activity and enantioselectivity of the CRL was also investigated by employing 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5 mM concentrations of it in phosphate buffer solution of the biphasic medium. High concentrations of Triton X‐100 stimulated the enzyme activity up to 1.66 fold after 24 h incubation. Triton X‐100 increased the hydrolysis rate almost independently of the concentration.
Amavadin and Other Vanadium Complexes as Remarkably Efficient Catalysts for One‐Pot Conversion of Ethane to Propionic and Acetic Acids
Authors: Kirillova Marina V. , Kuznetsov Maxim L. , da Silva José A. L. , Guedes da Silva Maria Fátima C. , Fraústo da Silva João J. R. , Pombeiro Armando J. L.
Published: December 2007

Synthetic amavadin Ca[V{ON[CH(CH3)COO]2}2] and its models Ca[V{ON(CH2COO)2}2] and [VO{N(CH2CH2O)3}], in the presence of K2S2O8 in trifluoroacetic acid (TFA), exhibit remarkable catalytic activity for the one‐pot carboxylation of ethane to propionic and acetic acids with the former as the main product (overall yields up to 93 %, catalyst turnover numbers (TONs) up to 2.0×104). The simpler V complexes [VO(CF3SO3)2], [VO(acac)2] and VOSO4 are less active. The effects of various factors, namely, C2H6 and CO pressures, time, temperature, and amounts of catalyst, TFA and K2S2O8, have been investigated, and this allowed optimisation of the process and control of selectivity. 13C‐labelling experiments indicated that the formation of acetic acid follows two pathways, the dominant one via oxidation of ethane with preservation of the CC bond, and the other via rupture of this bond and carbonylation of the methyl group by CO; the CC bond is retained in the formation of propionic acid upon carbonylation of ethane. The reactions proceed via both C‐ and O‐centred radicals, as shown by experiments with radical traps. On the basis of detailed DFT calculations, plausible reaction mechanisms are discussed. The carboxylation of ethane in the presence of CO follows the sequential formation of C2H5., C2H5CO., C2H5COO. and C2H5COOH. The C2H5COO. radical is easily formed on reaction of C2H5CO. with a peroxo V catalyst via a V{η1‐OOC(O)C2H5} intermediate. In the absence of CO, carboxylation proceeds by reaction of C2H5. with TFA. For the oxidation of ethane to acetic acid, either with preservation or cleavage of the CC bond, metal‐assisted and purely organic pathways are also proposed and discussed.
Synthesis of chiral vicinal diols and analysis of them by capillary zone electrophoresis
Authors: Liu Peng , He Wei , Zhao Yan , Wang Ping‐An , Sun Xiao‐Li , Li Xiao‐Ye , Zhang Sheng‐Yong
Published: December 2007

This paper describes an improved access to 1,4‐bis (9‐O‐quininyl) phthalazine [(QN)2PHAL], a very useful chiral ligand for catalytic asymmetric dihydroxylation (AD), by using CaH2 as acid‐binding reagent in a high yield under mild conditions. The application of (QN)2PHAL to the AD reactions of eight olefins exhibited excellent enantioselectivity and activity with corresponding chiral vicinal diols. Furthermore, a capillary zone electrophoresis method was developed to separate the aforementioned chiral vicinal diols by using of neutral β‐cyclodextrin (β‐CD) as chiral selector and borate as running buffer. High resolution was achieved under the optimal conditions of β‐CD 2.2% (w/v), pH 10, 200 mM borate buffer at 15 kV, and 20°C within 15 min. The relative standard deviations of the corrected peak areas and migration time were less than 3.9% and 1.3%, respectively. In addition, the developed method was successfully applied to the determination of the purity and the enantiomeric excesses value (%ee) of the AD reaction products. Chirality, 2008. © 2007 Wiley‐Liss, Inc.
The presence of halide salts influences the non‐covalent interaction of MRI contrast agents and human serum albumin
Authors: Henrotte Virginie , Muller Robert N. , Bartholet Annick , Elst Luce Vander
Published: December 2007

The rationale and objectives of the study were to evaluate the influence of the experimental conditions (buffer, salt, etc.) on the data characterizing the non‐covalent interaction between MRI contrast agents and human serum albumin and hence their in vivo relaxivity. The interaction of three gadolinium contrast agents (Gd‐EOB‐DTPA, Gd‐BOPTA and MP‐2269) with human serum albumin was assessed through the measurement of proton relaxation rate enhancement in various experimental conditions. The data show the negative effect of halide salts on the paramagnetic relaxation enhancement of the three contrast agents. The presence of halide salts can thus have a negative effect on the efficacy of MRI contrast agents interacting with HSA. In addition, careful attention must be paid to comparisons of the binding parameters of various contrast agents reported in different studies since the composition of the medium can greatly influence the non‐covalent interaction. Copyright © 2007 John Wiley & Sons, Ltd.
ghrelinis a novel target of Pax4 in endocrine progenitors of the pancreas and duodenum
Authors: Wang Qian , Elghazi Lynda , Martin Sophie , Martins Isabelle , Srinivasan R. Satish , Geng Xin , Sleeman Mark , Collombat Patrick , Houghton Janet , Sosa‐Pineda Beatriz
Published: December 2007

Pax4‐deficient mice have a severe gastrointestinal endocrine deficiency: they lack most pancreatic cells that produce insulin or somatostatin and various duodenal endocrine cell types. Remarkably,Pax4‐deficient mice also have an overabundance of ghrelin‐expressing cells in the pancreas and duodenum. Detailed analysis of thePax4nullizygous pancreas determined that the mutant islets are largely composed of a distinctive endocrine cell type that expresses ghrelin, glucagon, islet amyloid polypeptide (IAPP), and low levels of Pdx1. Lineage‐tracing analysis revealed that most of these unique endocrine cells directly arose fromPax4‐deficient progenitors. Previous in vitro work reported that Pax4 is a transcriptional repressor ofislet amyloid polypeptide(IAPP) andglucagon. In this study, we expanded those results by showing that Pax4 is also a repressor ofgherlin. Together, our data further support the notion that Pax4 activity is necessary to establish appropriate patterns of gene expression in endocrine progenitors of the digestive tract. Developmental Dynamics 237:51–61, 2008. © 2007 Wiley‐Liss, Inc.
Midkine‐b regulates cell specification at the neural plate border in zebrafish
Authors: Liedtke Daniel , Winkler Christoph
Published: December 2007

Midkines compose a family of secreted, heparin‐binding growth factors with neurotrophic activity in vitro, but largely unknown functions in mammals in vivo. Here we show that one member of this family, Midkine‐b (Mdkb), is responsible for establishment of the neural plate border in zebrafish. We propose that MdkB acts downstream of several signaling factors, most notably retinoic acid, implicated in neural crest cell (ncc) induction and refines a zone of competence for ncc and Rohon‐Beard (RB) sensory neuron formation. Overexpression of Mdkb expands the cell numbers of various ncc precursor subtypes and results in a significant increase in the number of RB neurons at the neural plate border. On the other hand, Morpholino‐mediated knockdown of Mdkb leads to a dramatic reduction of ncc and a loss of sensory neurons. Our results imply that Mdkb is required for the earliest steps of cell specification at the neural plate border in zebrafish. Developmental Dynamics 237:62–74, 2008. © 2007 Wiley‐Liss, Inc.
β1 integrin expression on endothelial cells is required for angiogenesis but not for vasculogenesis
Authors: Tanjore Harikrishna , Zeisberg Elisabeth M. , Gerami‐Naini Behzad , Kalluri Raghu
Published: December 2007

Integrins are a family of cell adhesion receptors that are involved in cell–matrix and cell–cell communications. They facilitate cell proliferation, migration, and survival. Using the Cre‐Lox system, we deleted β1 integrin on Tie2‐positive (Tie2‐cre β1 Int fl/fl) vascular endothelial cells. Deletion of β1 integrin on vascular endothelial cells results in embryonic lethality. Blood vessel defects are encountered in the Tie2‐Cre β1 Int fl/fl embryos at embryonic age (E9.5), and embryos die before reaching E10.5. The embryos exhibit growth retardation and both histological evaluation and PECAM‐1 staining of E9.5 embryos revealed defects in angiogenic sprouting and vascular branching morphogenesis. Large and medium‐size vessel formation is not affected in these embryos. Angiogenic defects were observed in several regions of the embryo and yolk sacs. These results indicate that β1 integrin expression on vascular endothelial cells is crucial for embryonic angiogenesis but dispensable for vasculogenesis. Developmental Dynamics 237:75–82, 2008. © 2007 Wiley‐Liss, Inc.
Functional evolutionary history of the mouse Fgf gene family
Authors: Itoh Nobuyuki , Ornitz David M.
Published: December 2007

Fibroblast Growth Factors (FGFs) are polypeptides with diverse activities in development and physiology. The mammalian Fgf family can be divided into the intracellular Fgf11/12/13/14 subfamily (iFGFs), the hormone‐like Fgf15/21/23 subfamily (hFGFs), and the canonical Fgf subfamilies, including Fgf1/2/5, Fgf3/4/6, Fgf7/10/22, Fgf8/17/18, and Fgf9/16/20. However, all Fgfs are evolutionarily related. We propose that an Fgf13‐like gene is the ancestor of the iFgf subfamily and the most likely evolutionary ancestor of the entire Fgf family. Potential ancestors of the canonical and hFgf subfamilies, Fgf4‐, Fgf5‐, Fgf8‐, Fgf9‐, Fgf10‐, and Fgf15‐like, appear to have derived from an Fgf13‐like ancestral gene. Canonical FGFs function in a paracrine manner, while hFGFs function in an endocrine manner. We conclude that the ancestral Fgfs for these subfamilies acquired this functional diversity before the evolution of vertebrates. During the evolution of early vertebrates, the Fgf subfamilies further expanded to contain three or four members in each subfamily. Developmental Dynamics 237:18–27, 2008. © 2007 Wiley‐Liss, Inc.
Nuclear localization of the zebrafish tight junction protein nagie oko
Authors: Bit‐Avragim Nana , Rohr Stefan , Rudolph Franziska , Van Der Ven Peter , Fürst Dieter , Eichhorst Jenny , Wiesner Burkhard , Abdelilah‐Seyfried Salim
Published: December 2007

The tight junctions‐associated MAGUK protein nagie oko is closely related to Drosophila Stardust, mouse protein associated with lin‐seven 1 (Pals1), and human MAGUK p55 subfamily member 5 (Mpp5). As a component of the evolutionarily conserved Crumbs protein complex, nagie oko is essential for the maintenance of epithelial cell polarity. Here, we show that nagie oko contains a predicted nuclear export and two conserved nuclear localization signals. We find that loss of the predicted nuclear export signal results in nuclear protein accumulation. We show that nagie oko nuclear import is redundantly controlled by the two nuclear localization signals and the evolutionarily conserved region 1 (ECR1), which links nagie oko with Par6‐aPKC. Finally, deletion forms of nagie oko that lack nuclear import and export signals complement several nagie oko mutant defects in cell polarity and epithelial integrity. This finding provides an entry point to potentially novel and unknown roles of this important cell polarity regulator. Developmental Dynamics 237:83–90, 2008. © 2007 Wiley‐Liss, Inc.
(Pentamethylcyclopentadienyl)iridium‐PTA (PTA = 1,3,5‐Triaza‐7‐phosphaadamantane) Complexes and Their Application in Catalytic Water Phase Carbon Dioxide Hydrogenation
Authors: Erlandsson Mikael , Landaeta Vanessa R. , Gonsalvi Luca , Peruzzini Maurizio , Phillips Andrew D. , Dyson Paul J. , Laurenczy Gábor
Published: December 2007

The water‐soluble iridium(III) complexes [Cp*Ir(PTA)Cl2] (1) and [Cp*Ir(PTA)2Cl]Cl (2) (PTA = 1,3,5‐triaza‐7‐phosphaadamantane) have been synthesised and characterised by spectroscopy and X‐ray crystallography. The complexes were evaluated as catalyst precursors for the hydrogenation of CO2 and hydrogen carbonate in aqueous solutions, in the absence of amines or other additives, under relatively mild conditions. Complex 1 performed poorly while 2 catalyses the hydrogenation with moderate activity. The catalytically active monohydride [Cp*Ir(PTA)2H]+ was identified by multinuclear NMR spectroscopy and its nature confirmed by independent synthesis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Highly Efficient Copper‐Mediated Atom‐Transfer Radical Addition (ATRA) in the Presence of Reducing Agent
Authors: Eckenhoff William T. , Garrity Sean T. , Pintauer Tomislav
Published: December 2007

The synthesis, characterization and exceptional activity of CuI(TPMA)Br [TPMA = tris(2‐pyridylmethyl)amine] and [CuII(TPMA)Br][Br] complexes in ATRA reactions of polybrominated compounds to alkenes in the presence of reducing agent (AIBN) was reported. [CuII(TPMA)Br][Br], in conjunction with AIBN, effectively catalyzed ATRA reactions of CBr4 and CHBr3 to alkenes with concentrations between 5 and 100 ppm, which is the lowest number achieved in copper‐mediated ATRA. The molecular structure of CuI(TPMA)Br indicated that the complex was pseudo‐pentacoordinate in the solid state due to the coordination of TPMA [CuI–N: 2.1024(15), 2.0753(15), 2.0709(15) and 2.4397(14) Å] and bromide anion to the copper(I) center [CuI–Br 2.5088(3) Å]. Variable temperature 1H NMR and cyclic voltammetry studies confirmed the equilibrium between CuI(TPMA)Br and [CuI(TPMA)(CH3CN)][Br], indicating some degree of halide anion dissociation in solution. The coordination of the bromide anion to the [CuI(TPMA)]+ cation resulted in a formation of much more reducing CuI(TPMA)Br complex (E1/2 = –720 mV vs. Fc/Fc+) than the corresponding ClO4– (E1/2 = –422 mV vs. Fc/Fc+) and PF6– (E1/2 = –421 mV vs. Fc/Fc+) analogues. In [CuII(TPMA)Br][Br], the CuII atom was coordinated by four nitrogen atoms [CuII–Neq 2.073(2) Å and CuII–Nax 2.040(3) Å] from TPMA ligand and a bromine atom [CuII–Br 2.3836(6) Å]. The overall geometry of the complex was distorted trigonal bipyramidal. CuI(TPMA)Br and [CuII(TPMA)Br][Br] complexes showed similar structural features from the point of view of TPMA coordination. The only more pronounced difference in the TPMA coordination to the copper center was observed in the shortening of Cu–Nax bond length by approximately 0.400 Å on going from CuI(TPMA)Br to [CuII(TPMA)Br][Br]. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
β‐Fluorinated Porphyrins and Related Compounds: An Overview
Authors: Leroy Jacques , Bondon Arnaud
Published: December 2007

Apart from a few examples, β‐(poly)fluorinated and β‐(poly)perfluoroalkylated porphyrins were practically unknownuntil recently. In particular, β‐octafluoro‐meso‐tetraarylporphyrins remained elusive ligands owing to the lack of any convenient access. The aim of this microreview is to highlight recent progress in the synthesis and characterization of β‐fluoroporphyrins and β‐(perfluoroalkyl)porphyrins, two new classes of so‐called electron‐deficient porphyrins. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Hydrolysis of Toxic Natural Glucosides Catalyzed by Cyclodextrin Dicyanohydrins
Authors: Bjerre Jeannette , Nielsen Erik Holm , Bols Mikael
Published: December 2007

The hydrolysis of toxic 7‐hydroxycoumarin glucosides and other aryl and alkyl glucosides, catalyzed by modified α‐ and β‐cyclodextrin dicyanohydrins, was investigated using different UV, redox, or HPAEC detection assays. The catalyzed reactions all followed Michaelis–Menten kinetics, and an impressive rate increase of up to 7569 (kcat/kuncat) was found for the hydroxycoumarin glucoside substrate 4‐MUGP. Good and moderate degrees of catalysis (kcat/kuncat) of up to 1259 were found for the natural glucosides phloridzin and skimmin. By using a newly developed catechol detection UV‐assay, a weak degree of catalysis was also found for the toxic hydroxycoumarin esculin. A novel synthesized diaminomethyl β‐cyclodextrin showed a weak catalysis of p‐nitrophenyl β‐D‐glucopyranoside hydrolysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Catalyst development for stable hydrogen generation during steam reforming of renewable and nonrenewable resources
Authors: Sharma Pradeepkumar O. , Swami Sadashiv , Goud Sandeep , Abraham Martin A.
Published: December 2007

The production of hydrogen from renewable and nonrenewable resources is demonstrated. Catalytic steam reforming, using a rhodium‐containing catalyst, is shown to be effective for the conversion of natural gas and n‐hexadecane (used as a simulant for diesel fuel). Improved conversion efficiencies can be achieved by performing the reaction at higher temperatures and steam to carbon ratios. The presence of sulfur in the fuel is shown to have a significant inhibiting effect on catalyst performance. Steam reforming of biomass‐derived species is less effective when compared with that of simpler compounds such as methane and methanol, because these species decompose to produce tars and chars at temperatures below which steam reforming reactions are effective. Autothermal reforming has been shown to be relatively effective for several biomass‐derived species. © 2007 American Institute of Chemical Engineers Environ Prog, 2008
Bioethanol from agricultural waste residues
Authors: Champagne Pascale
Published: December 2007

Under the Kyoto Protocol, the Government of Canada has committed to reducing its greenhouse gas emissions by 6% from 1990 levels between 2008 and 2012. Ethanol‐blended gasolines have the potential to contribute significantly to these emission reductions. Ethanol is derived from biologically renewable resources and can be employed to replace octane enhancers and aromatic hydrocarbons or oxygenates. To date, the ethanol production industry in Canada is comprised mainly of small‐scale plants producing ethanol primarily from agricultural crops as feedstock. Research interests in the area of bioethanol production from organic waste materials emerged in the late 1980. Significant advances in lignocellulosic material extraction and enzymatic hydrolysis have been reported in the last decade, however, continued research efforts are essential for the development of technically feasible and economically viable large‐scale enzyme‐based biomass‐to‐ethanol conversion processes. This research aims to develop and test an enzyme‐based biomass‐to‐ethanol conversion process, which employs organic waste materials, such as livestock manures, as alternative sources of cellulosic material feedstock. The source of the livestock manure, manure management practices and cellulose extraction procedures have a significant impact on the quantity and quality of the cellulosic materials derived. As such, raw feedstock materials must be carefully characterized to assess the impact of these factors on the yield of bioethanol and residual end products. The success of cellulose‐to‐ethanol conversion processes for cellulose extracted from these waste materials as feedstock is generally a function of cellulose fiber pretreatment, enzyme selection and operating conditions. These will differ depending on the source of the waste material feedstock. The long‐term benefits of this research will be to introduce a sustainable solid waste management strategy for a number of livestock manure and other lignocellulosic waste materials; contribute to the mitigation in greenhouse gases through sustained carbon and nutrient recycling; reduce the potential for water, air, and soil contamination associated with land disposal of organic waste materials; and to broaden the feedstock source of raw materials for the ethanol production industry. © 2007 American Institute of Chemical Engineers Environ Prog, 2008
Notes on South American Valerianaceae IV
Authors: Weberling F.
Published: December 2007

Buscando characteres distintivos seguros hemos revisado un grupo posiblemente natural de 6 especies de Valeriana caracterizado por frutos con carpeles esteriles bien desarollados. Además las descripciones de V. boelckei Rossow y V. parvula Killip están completados. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Leaf architecture of Hamelieae (Rubiaceae)
Authors: Martínez‐Cabrera D. , Terrazas T. , Ochoterena H.
Published: December 2007

The tribe Hamelieae sensu Robbrecht comprises seven genera, and is traditionally placed in subfamily Rubioideae. Molecular data, however, places Hamelieae within Cinchonoideae. In this study, leaf architecture characters were examined in order to provide further evidence for the circumscription of Hamelieae and discuss its placement in the proposed subfamilies. Leaves from 34 species belonging to six genera of the Hamelieae, plus Syringantha and representative species of Psychotrieae (Rubioideae), Cinchoneae (Cinchonoideeae) and Gardenieae (Ixoroideae) were studied in order to describe and compare their leaf architecture. The results showed that there are macromorphological characters shared by members of Hamelieae. The venation of Hamelieae is brochidodromous, as in the other sampled taxa, except Bouvardia, which has actinodromous venation and Randia with eucamptodromous‐brochidodromous venation. In Hamelieae and Psycho‐ trieae, marginal ultimate venation forms a fimbrial vein and raphides are present in the mesophyll, while in representatives of Cinchoneae and Gardenieae, marginal ultimate venation is incomplete and raphides are absent. Syringantha is distinguished by its narrow elliptical to lanceolate lamina, but shares several attributes with Hamelia and Hoffmannia. These attributes support the proposal to include Syringantha in Hamelieae. The results neither resolve the placement of Hamelieae in Rubioideae or Cinchonoideae. However, our current phylogenetic understanding of the family, placing this tribe in a clade within Cinchonoideae, suggests that raphides arised more than once independently, thus raphides should not be a taxonomic marker to define the Rubioideae. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characteristics associated with benzodiazepine usage in elderly outpatients in Taiwan
Authors: Cheng Jur‐Shan , Huang Weng‐Foung , Lin Keh‐Ming , Shih Yaw‐Tang
Published: December 2007

Objective

To investigate benzodiazepine usage and the characteristics associated with usage among elderly outpatients in Taiwan.

Methods

This was an observational study of subjects who were enrolled in the National Health Insurance program and aged at least 65 in 2002. They were grouped according to treatment period and mean dosage. An ordered logit regression model was used to evaluate associations of characteristics with benzodiazepine usage.

Results

Of the 4,267 elderly people included, 1,826 had received at least one prescription for benzodiazepines. The 1‐year prevalence of benzodiazepine usage by elderly outpatients was approximately 43%. Characteristics associated with receiving benzodiazepine therapy included female gender, displaying comorbid insomnia, anxiety, depression, other mental diseases, cardiovascular disease, cancer, chronic obstructive pulmonary disease, arthritis, and previous use of benzodiazepines. Individuals older than 75 years, with comorbid insomnia, anxiety, depression, other mental diseases, cardiovascular disease, cancer, being in previous receipt of benzodiazepines, or high prescription‐overlap ratio were more likely to receive longer treatment. Individuals with insomnia, anxiety, depression, and previous use of higher cumulative dosage of benzodiazepine were more likely to receive higher‐dosage therapy.

Conclusions

Mental disorders and previous exposure to higher cumulative dosages of benzodiazepines are associated with an increased likelihood of receiving benzodiazepine therapy, longer treatment, and a higher mean dosage. Older individuals, less likely to receive higher dosage benzodiazepine therapy, are more likely to receive more prolonged therapy. Women are more likely to receive benzodiazepine therapy, but both men and women have comparable benzodiazepine usage patterns. Copyright © 2007 John Wiley & Sons, Ltd.
APOE genotype predicts depression in women with Alzheimer's disease: a retrospective study
Authors: Delano‐Wood Lisa , Houston Wes S. , Emond Jennifer A. , Marchant Natalie L. , Salmon David P. , Jeste Dilip V. , Thal Leon J. , Bondi Mark W.
Published: December 2007

Objective

The association between the APOE ε4 allele and depression was investigated in a retrospective study of 323 AD patients.

Methods

Patients were divided into demographically comparable groups based on the presence or absence of depression.

Results

Results showed that the frequency of APOE ε4 allele was significantly higher in the depressed vs non‐depressed AD patients (72% and 58%, respectively), and an interaction revealed that women possessing the APOE ε4 allele were almost four times more likely to be depressed than those without the ε4 allele.

Conclusion

Results are consistent with recent suggestions that the APOE ε4 genotype may be over‐represented among depressed women with AD and highlight the need for additional research investigating the links between APOE genotype, mood, and gender. Copyright © 2007 John Wiley & Sons, Ltd.