bluuebunny/crossref_metadata_2025 huggingface dataset:
Primary Neuron/Astrocyte Co‐Culture on Polyelectrolyte Multilayer Films: A Template for Studying Astrocyte‐Mediated Oxidative Stress in Neurons
Authors: Kidambi S. , Lee I. , Chan C.
Published: January 2008

We engineered patterned co‐cultures of primary neurons and astrocytes on polyelectrolyte multilayer (PEM) films without the aid of adhesive proteins/ligands to study the oxidative stress mediated by astrocytes on neuronal cells. A number of studies have explored engineering co‐culture of neurons and astrocytes predominantly using cell lines rather than primary cells owing to the difficulties involved in attaching primary cells onto synthetic surfaces. To our knowledge this is the first demonstration of patterned co‐culture of primary neurons and astrocytes for studying neuronal metabolism. In our study, we used synthetic polymers, namely poly(diallyldimethylammoniumchloride) (PDAC) and sulfonated poly(styrene) (SPS) as the polycation and polyanion, respectively, to build the multilayers. Primary neurons attached and spread preferentially on SPS surfaces, while primary astrocytes attached to both SPS and PDAC surfaces. SPS patterns were formed on PEM surfaces, either by microcontact printing SPS onto PDAC surfaces or vice‐versa, to obtain patterns of primary neurons and patterned co‐cultures of primary neurons and astrocytes. We further used the patterned co‐culture system to study the neuronal response to elevated levels of free fatty acids as compared to the response in separated monoculture by measuring the level of reactive oxygen species (ROS; a widely accepted marker of oxidative stress). The elevation in the ROS levels was observed to occur earlier in the patterned co‐culture system than in the separated monoculture system. The results suggest that this technique may provide a useful tool for engineering neuronal co‐culture systems, that may more accurately capture neuronal function and metabolism, and thus could be used to obtain valuable insights into neuronal cell function and perhaps even the pathogenesis of neurodegenerative diseases.
Formulation of Superparamagnetic Iron Oxides by Nanoparticles of Biodegradable Polymers for Magnetic Resonance Imaging
Authors: Wang Y. , Ng Y. W. , Chen Y. , Shuter B. , Yi J. , Ding J. , Wang S.‐c. , Feng S. S.
Published: January 2008

A system of poly(lactide‐co‐glycolide)‐methoxy poly(ethylene glycol) (PLGA‐mPEG) nanoparticles is developed to formulate superparamagnetic iron oxides (IOs) for magnetic resonance imaging (MRI). This system improves the imaging effects, increases the half‐life of the IOs in circulation, and reduces their side effects. The IO‐loaded PLGA‐mPEG nanoparticles were prepared by a modified water‐in‐oil‐in‐water double‐emulsion technique. Their physicochemical and superparamagnetic properties were characterized by various techniques. In vitro IO release kinetics from the nanoparticles and stability of the IO‐loaded polymeric nanoparticles were also investigated. In vitro and ex vivo MRI of the IOs formulated in the PLGA‐mPEG nanoparticles show that the saturation magnetization and ther2,r2* relaxivities are enhanced, and the contrast effects are improved in comparison with commercial IOs (Resovist). It is proven that the enhanced superparamagnetic properties are caused by the polymeric nanoparticle formulation but not by the polymeric material itself. Moreover, the PLGA‐mPEG nanoparticle formulation achieves 36.9 and 35.6 % less cytotoxicity in comparison with the IOs (Resovist) after 48 h incubation at the same 20 and 50 μg mL–1Fe concentration, respectively. This research implies that formulation of IOs by nanoparticles of PLGA‐mPEG copolymer or other biodegradable polymers could be promising for more effective and sustainable MRI with reduced side effects, which, with targeting probes conjugated to the nanoparticle surface, can be further used to promote cellular and molecular MRI.
Exploitation of Diatom Frustules for Nanotechnology: Tethering Active Biomolecules
Authors: Townley H. E. , Parker A. R. , White‐Cooper H.
Published: January 2008

Diatoms are single‐celled microalgae with rigid walls (frustules) composed of amorphous silica. The intricate 3D microstructure of diatoms results in a high surface area formed by myriad pores and channels. The combination of the silica chemistry of the frustule coupled with the high surface area makes it particularly suitable for applications such as microscale total analysis systems. Here it is demonstrated that the diatom frustule can be chemically modified for the attachment of antibodies, and that the attached antibodies retain biological activity. These modified structures have potential applications in antibody arrays and may have use in techniques such as immunoprecipitation. These silica structures are produced in diatoms using only light and minimal nutrients and, therefore, generate an exceptionally cheap and renewable material.
Red‐Light‐Emitting Iridium Complexes with Hole‐Transporting 9‐Arylcarbazole Moieties for Electrophosphorescence Efficiency/Color Purity Trade‐off Optimization
Authors: Ho C.‐L. , Wong W.‐Y. , Gao Z.‐Q. , Chen C.‐H. , Cheah K.‐W. , Yao B. , Xie Z.‐Y. , Wang Q. , Ma D.‐G. , Wang L.‐X. , Yu X.‐M. , Kwok H.‐S. , Lin Z.‐Y.
Published: January 2008

The synthesis, structures, photophysics, electrochemistry and electrophosphorescent properties of new red phosphorescent cyclometalated iridium(III) isoquinoline complexes, bearing 9‐arylcarbazolyl chromophores, are reported. The functional properties of these red phosphors correlate well with the results of density functional theory calculations. The highest occupied molecular orbital levels of these complexes are raised by the integration of a carbazole unit to the iridium isoquinoline core so that the hole‐transporting ability is improved in the resulting complexes relative to those with 1‐phenylisoquinoline ligands. All of the complexes are highly thermally stable and emit an intense red light at room temperature with relatively short lifetimes that are beneficial for highly efficient organic light‐emitting diodes (OLEDs). Saturated red OLEDs, fabricated using these dyes as the phosphorescent dopants both as vacuum‐evaporated and spin‐coated emissive layers, have been achieved in a multilayer configuration with outstanding red color purity at Commission International de L'Éclairage (CIE) coordinates of (0.67,0.33) to (0.68,0.32). Some of the devices can show very high efficiencies with a maximum external quantum efficiency of up to 12 % photons per electron. The excellent performance of these red emitters indicates the advantage of the carbazole module in the ligand framework; demonstrated by an improved hole‐transporting ability that facilitates exciton transport. These materials could thus provide a new avenue for the rational design of heavy‐metal electrophosphors that reveal a superior device efficiency/color purity trade‐off necessary for pure red‐light generation.
Silicone–Poly(hexylthiophene) Blends as Elastomers with Enhanced Electromechanical Transduction Properties
Authors: Carpi F. , Gallone G. , Galantini F. , De Rossi D.
Published: January 2008

Dielectric elastomers are progressively emerging as one of the best‐performing classes of electroactive polymers for electromechanical transduction. They are used for actuation devices driven by the so‐called Maxwell stress effect. At present, the need for high‐driving electric fields limits the use of these transduction materials in some areas of potential application, especially in the case of biomedical disciplines. A reduction of the driving fields may be achieved with new elastomers offering intrinsically superior electromechanical properties. So far, most attempts in this direction have been focused on the development of composites between elastomer matrixes and high‐permittivity ceramic fillers, yielding limited results. In this work, a different approach was adopted for increasing the electromechanical response of a common type of dielectric elastomer. The technique consisted in blending, rather than loading, the elastomer (poly(dimethylsiloxane)) with a highly polarizable conjugated polymer (undoped poly(3‐hexylthiophene)). The resulting material was characterised by dielectric spectroscopy, scanning electron microscopy, tensile mechanical analysis, and electromechanical transduction tests. Very low percentages (1–6 wt %) of poly(3‐hexylthiophene) yielded both an increase of the relative dielectric permittivity and an unexpected reduction of the tensile elastic modulus. Both these factors synergetically contributed to a remarkable increase of the electromechanical response, which reached a maximum at 1 wt % content of conjugated polymer. Estimations based on a simple linear model were compared with the experimental electromechanical data and a good agreement was found up to 1 wt %. This approach may lead to the development of new types of materials suitable for several types of applications requiring elastomers with improved electromechanical properties.
The 2,2,6,6‐Tetramethyl‐1‐piperidinyloxy Radical: An Efficient, Iodine‐ Free Redox Mediator for Dye‐Sensitized Solar Cells
Authors: Zhang Z. , Chen P. , Murakami T. N. , Zakeeruddin S. M. , Grätzel M.
Published: January 2008

A promising redox system, offering an alternative to the widely used iodide/triiodide couple, based on the stable organic radical 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) has been employed in dye‐sensitized solar cells. The photovoltaic performance of this new redox couple has been evaluated by employing nanocrystalline TiO2 films with different thickness. Judicious selections of a 5.0 μm photoanode made from TiO2 mesoscopic particles and an organic sensitizer with a high molar extinction coefficient yield an overall solar‐to‐electric power conversion efficiency of 5.4 % under AM 1.5 illumination at 100 mW cm–2, which is unprecedented for an iodine‐free mediator system.
Inside Front Cover: Unprecedented Dual Alignment Mode and Freedericksz Transition in Planar Nematic Liquid Crystal Cells Doped with Gold Nanoclusters (Adv. Funct. Mater. 2/2008)
Authors: Qi H. , Kinkead B. , Hegmann T.
Published: January 2008

On p. 212, Torsten Hegmann and co‐workers describe nematic liquid crystals (N‐LCs) confined in planar liquid crystal cells after doping with small quantities of gold nanoclusters. These give rise to a dual alignment mode and electro‐optic response (Freedericksz transition). By fine‐tuning of experimental conditions, N‐LCs doped with gold nanoclusters can be electrically reoriented and aligned either like N‐LCs with a positive dielectric anisotropy (used in twisted nematic displays) in a planar cell or alternatively as N‐LCs with a negative dielectric anisotropy (used in large LCD TVs based on the vertical alignment mode).

We demonstrate that alkylthiol‐capped gold nanoclusters doped into nematic liquid crystals (N‐LCs) with positive dielectric anisotropy give rise to an unprecedented dual alignment mode and electro‐optical response, which has a potential impact on current liquid crystal (LC) display technologies and N‐LC optical‐biosensor design. By fine‐tuning experimental conditions (temperature, electric field, and alignment), N‐LCs doped with gold nanoclusters can be aligned and electrically reoriented either like N‐LCs with a positive dielectric anisotropy in a planar cell or, alternatively, as N‐LCs with a negative dielectric anisotropy in a homeotropic cell, both at lower threshold voltages than the pure N‐LC.
Organic Electronics: The Ions Have It
Authors: Leger J. M.
Published: January 2008

Organic electronics research has focused primarily on flexible, inexpensive versions of traditional semiconductor technologies. Although mixed ionic/electronic conduction in conjugated organic materials introduces exciting functionality, the understanding of the fundamental processes that take place is still in its infancy. In this Research News article, the advantages, applications, and basic research needs that relate to the incorporation of ionic carriers in organic electronic materials and devices are discussed and placed in the broader context of the field.
Managing risk through a flexible recipe framework
Authors: Ferrer‐Nadal Sergio , Puigjaner Luis , Guillén‐Gosálbez Gonzalo
Published: January 2008

A novel approach is proposed that exploits the use of a flexible recipe framework as a better way to handle the risk associated with the scheduling under uncertainty of batch chemical plants. The proposed solution strategy relies on a novel two‐stage stochastic formulation that explicitly includes the trade‐off between risk and profit at the decision‐making level. The model uses a continuous‐time domain representation and the generalized notion of precedence. Management of risk is explicitly addressed by including a control measure (i.e., the profit in the worst scenario), as an additional objective to be considered, thus, leading to a multiobjective optimization problem. To overcome the numerical difficulties associated with such mathematical formulation, a decomposition strategy based on the sample average approximation (SAA) is introduced. The main advantages of this approach are illustrated through a case study, in which a set of solutions appealing to decision makers with different attitudes toward risk are obtained. The potential benefits of the proposed flexible recipe framework as a way of managing the risk associated with the plant operation under demand uncertainty are highlighted through comparison with the conventional approach that considers nominal operating conditions. Numerical results corroborate the advantages of exploiting the capabilities of the proposed flexible recipe framework for risk management purposes. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Varying the blending protocol to control the morphology of model compatibilized polymer blends
Authors: Martin Jeffrey D. , Velankar Sachin S.
Published: January 2008

The structure of an oil/water emulsion is known to depend on its preparation method. Here, we test whether the preparation protocol can be used to control the morphology of “model” blends of immiscible polymers compatibilized by a diblock copolymer. Two preparation protocols were tested. In the “double blending” protocol, a droplet‐matrix blend was blended with additional drop‐phase fluid. As in oil/water emulsions, this yielded a drop‐within‐drop “double emulsion” morphology. Coalescence suppression due to compatibilizer was found crucial to double emulsion stability. The rheology of the double emulsion was qualitatively similar to that of a simple droplet‐matrix blend, but with an effectively higher drop volume fraction. In the “multistep concentration” protocol, the drop phase was added gradually (rather than all‐at‐once) to the matrix phase. While this protocol can realize a high‐dispersed phase emulsion in oil/water systems, in this case, phase inversion occurred when the drop volume fraction exceeded 0.5. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Memory enhancement induced by hypothalamic/fornix deep brain stimulation
Authors: Hamani Clement , McAndrews Mary Pat , Cohn Melanie , Oh Michael , Zumsteg Dominik , Shapiro Colin M. , Wennberg Richard A. , Lozano Andres M.
Published: January 2008

Bilateral hypothalamic deep brain stimulation was performed to treat a patient with morbid obesity. We observed, quite unexpectedly, that stimulation evoked detailed autobiographical memories. Associative memory tasks conducted in a double‐blinded “on” versus “off” manner demonstrated that stimulation increased recollection but not familiarity‐based recognition, indicating a functional engagement of the hippocampus. Electroencephalographic source localization showed that hypothalamic deep brain stimulation drove activity in mesial temporal lobe structures. This shows that hypothalamic stimulation in this patient modulates limbic activity and improves certain memory functions. Ann Neurol 2008;63:119–123
The olfactory vector hypothesis of neurodegenerative disease: Is it viable?
Authors: Doty Richard L.
Published: January 2008

Environmental agents, including viruses, prions, and toxins, have been implicated in the cause of a number of neurodegenerative diseases, most notably Alzheimer's and Parkinson's diseases. The presence of smell loss and the pathological involvement of the olfactory pathways in the formative stages of Alzheimer's and Parkinson's diseases, together with evidence that xenobiotics, some epidemiologically linked to these diseases, can readily enter the brain via the olfactory mucosa, have led to the hypothesis that Alzheimer's and Parkinson's diseases may be caused or catalyzed by agents that enter the brain via this route. Evidence for and against this concept, the “olfactory vector hypothesis,” is addressed in this review. Ann Neurol 2008;63:7–15
Synthesis and characterization of poly(acryloxyethyl‐trimethylammonium chloride‐co‐2‐hydroxyethyl methacrylate): A study of its interaction with sodium alginate
Authors: Valdés Oscar , Monett Dagmar , Agüero Lissette , Zaldívar Dionisio , Alexandrova Larissa , Katime Issa
Published: January 2008

Poly(acryloxyethyl‐trimethylammonium chloride‐co‐2‐hydroxyethyl methacrylate) [poly(Q‐co‐H)] was prepared by free radical polymerization in aqueous solution at 60°C using potassium persulfate as initiator. Spectroscopic characterization confirmed the formation of poly(Q‐co‐H) and the molar fractions of acryloxyethyl‐trimethylammonium chloride monomer units incorporated in the copolymers were determined by potenciometric titrations. The monomer reactivity ratios for Q and H are found to be rQ = 0.04 ± 0.01 and rH = 3.22 ± 0.84 using Fineman–Röss method and rQ = 0.06 and rH = 3.61 using Genetic Algorithms method. Finally we studied reaction between poly(Q‐co‐H) and sodium alginate by conductimetric measurement. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
The linear viscoelastic behaviors of Nylon1212 blends toughened with elastomer
Authors: Wang Wanjie , Shangguan Yonggang , Zhao Li , Yu Jie , He Li , Tan Hong , Zheng Qiang
Published: January 2008

The linear viscoelastic behaviors of nylon1212 blends toughened with (styrene‐[ethylene‐(ethylene‐propylene)]‐styrene block copolymer) (SEEPS) elastomer were carried out. The results show that dynamic storage modulus (G′) curves of the blends are located between those of virgin nylon and SEEPS within the frequency (ω) tested, and the G′ of blends increases with increasing of the SEEPS content. Moreover, the predictive results of Palierne emulsion model show that it is unsuitable for describing the viscoelastic behaviors of the double phase systems toughened with elastomer, especially for the system with high content of elastomer. The positive deviation in the plots of G′ vs. blend composition demonstrates that the blends are immiscible. From the point of phase transition, the phase inversion region for these blends was predicted to be in the range of 30–50 wt % of SEEPS, which agrees with the morphology analysis of nylon1212/SEEPS blends. In addition, “Cole–Cole” plots of modulus at different temperatures show that the microstructures of blends are unstable in the phase transition region. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Experimental investigation and numerical simulation of the heating/cooling process in rotational molding enhanced with fins
Authors: Liu Shih‐Jung , Fu Kwang‐Hwa
Published: January 2008

Rotational molding has become one of the most important polymer processing methods for producing hollow plastic articles. However, the long‐cycle time required by the rotational molding process has confounded the overall success of this technology. Molds with extended surfaces (fins) have the potential to enhance heat transfer by increasing surface area. This report aims to investigate, both experimentally and numerically, the heating/cooling process of rotational molds enhanced with fins. Rotational molding experiments were carried out in a laboratory scale uniaxial machine, which is capable of measuring internal air temperature in the cycle. Molds enhanced with three types of fins, including pin, rectangular, and triangular fins, were used to manufacture the parts. It was found that the mold surface enhanced with pins exhibited the highest heating and cooling rate. Nevertheless, from a design perspective, ease of manufacturing needs to be taken into account which could make triangular fin geometry a better choice to enhanced heat transfer. In addition, an unsteady‐state, nonlinear heat transfer model of rotational molding has been proposed to numerically simulate the internal air temperature profiles. It is shown that the numerical predictions are in good agreement with experimental data. This model enables prediction of the heating and cooling time of rotational molding enhanced with fins, and hence the overall cycle time for the process. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Styrene‐assisted melt free‐radical grafting of pentaerythritol triacrylate onto polypropylene and its crystallization behavior
Authors: Wang Dong , Xie Xu‐Ming , Jow Jinder , Chen Hong‐Yu , Lai Shih‐Yaw
Published: January 2008

The free‐radical grafting of the multimonomer system of pentaerythritol triacrylate (PETA) and styrene (St) onto polypropylene (PP) in the melt state was studied by reactive extrusion. The effects of the St and initiator concentrations on the grafting reaction were investigated by means of the melt flow rate, gel permeation chromatography (GPC), and Fourier transform infrared spectroscopy. The results showed that the use of St as a comonomer could effectively depress the degradation of PP and enhance the grafting degree of PETA. Increasing the peroxide level promoted the degradation of PP and reduced the grafting degree of PETA. When the molar ratio of St to PETA was 3 : 1, the GPC data showed that the molecular weight of the grafted PP sample was almost equal to or a little higher than that of virgin PP, suggesting that almost no chain scission occurred. In the presence of St, the dominant grafting mechanism was that St reacted with the PP macroradicals to form more stable St macroradicals, and thus β scission was limited. Then, St macroradicals reacted with PETA to form PETA‐grafted PP. X‐ray diffraction results showed that the grafted chains not only had a good nucleating effect on PP crystallization but also might induce the formation of β‐form crystals. The presence of ungrafted PETA increased the crystallization and melting temperatures of PP; however, the PETA‐grafted samples showed higher crystallization and melting temperatures than physically blended samples. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Hide tanning with modified natural tannins
Authors: Tambi Lorenzo , Frediani Piero , Frediani Marco , Rosi Luca , Camaiti Mara
Published: January 2008

Tannin from “Acacia Mearnsii” usually called Mimosa, is largely employed in vegetal tanning of hide even if the quality of the leather is poorer than that obtained using chromium as tanning agents. However, taking into account the natural resources of this product and its reduced environmental impact, mimosa tannin has been modified to obtain leather having improved properties. Tannin was modified using formaldehyde, urea, a sulfonic acid and a sulfiting agent: The new products show a higher molecular weight than mimosa tannin but maintain a good solubility in water. Modified tannins were characterized through physicochemical and technological tests and evaluated as tanning agents. The properties of tanned leathers obtained using the new tannin products and mimosa were compared. Some of the polymers containing phenolsulfonic acid are good tannin agents, especially those with a suitable molecular weight. The technological and sensorial properties of the leather obtained using modified tannins (distension and strength of grain, tensile strength, elongation, and tear load) are better than those obtained using mimosa when an appropriate ratio of the reagents were employed. At the same time the feeling of the tanned leather was improved and the final products show fullness, elasticity, fluency, reactivity, and a thin and fine grain. Some of the tannins modified with naphtalensulfonic acid show poor tanning properties but good penetration in the leather suggesting their use as auxiliary sintans in the pretanning process. A simple procedure to prepare these modified tanning agents in the course of the tannin extraction is suggested. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Enhancement of thermal stability associated with the chemical treatment of bacterial (Gluconacetobacter xylinus) cellulose
Authors: George Johnsy , Sajeevkumar V. A. , Kumar R. , Ramana K. V. , Sabapathy S. N. , Bawa A. S.
Published: January 2008

Bacterial cellulose produced by Gluconacetobacter xylinus was treated with sodium carbonate (Na2CO3) and sodium hydroxide (NaOH) to remove entrapped noncellulosic materials. Fourier transform infrared (FTIR) spectroscopy has been used to investigate the effect of alkali on the chemical structure of bacterial cellulose. The changes in the crystalline nature of these membranes were analyzed using X‐ray diffraction (XRD) technique. The morphology and the removal of noncellulosic impurities followed by alkali treatment were studied using scanning electron microscopy (SEM) and energy dispersive X‐ray spectrometry (EDS). The enhanced thermal stability of bacterial cellulose was evident from thermogravimetric analysis (TGA). Further, the alkali treatments resulted in relatively pure form of cellulose, which finds application in various spheres. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation and tribological properties of poly(methyl methacrylate)/styrene/MWNTs copolymer nanocomposites
Authors: Dong B. , Wang C. , He B. L. , Li H. L.
Published: January 2008

Poly(methyl methacrylate)/styrene/multi‐walled carbon nanotubes (PMMA/PS/MWNTs) copolymer nanocomposites with different contents have been prepared successfully by means of in situ polymerization method. The structure and the microhardness of PMMA/PS/MWNTs copolymer nanocomposites were characterized. The tribological behaviors of the copolymer nanocomposites were investigated by a friction and wear tester under dry conditions. The relative humidity of the air was about 50% ± 10%. Comparing with pure PMMA/PS copolymer, the copolymer nanocomposites showed not only better wear resistance but also smaller friction coefficient. MWNTs could help the nanocomposites dramatically improve the wear resistance property. The mechanisms of the improvements on the tribological properties of the PMMA/PS/MWNTs copolymer nanocomposites were also discussed in detail. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
An antimicrobial cationic reactive dye: Synthesis and applications on cellulosic fibers
Authors: Zhao Tao , Sun Gang , Song Xinyuan
Published: January 2008

An antimicrobial cationic reactive dye was synthesized by reacting aminoanthraquinone with cyanuric chloride, 3‐dimethylamino‐1‐proponol, and lauryl chloride in sequence. The chemical structure of the dye was fully characterized by using 1H‐NMR, 13C‐NMR, and FTIR analysis. This dye demonstrated adequate antimicrobial properties in aqueous solution. The minimum inhibitory concentration of the dye against bacterial concentrations of 106–107 colony forming units (CFU)/mL of both E. coli and S. aureas were only 10 ppm. The dye can react with cotton without addition of any salt as electrolyte. The dyed fabrics showed proper color washing durability. But the antimicrobial functions were severely affected by laundry. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Frontal Fusion: Collapse of Another Anthropoid Synapomorphy
Authors: Rosenberger Alfred L. , Pagano Anthony S.
Published: January 2008

We test the hypothesis that the fused interfrontal suture of anthropoids is a uniquely distinguishing feature and a derived characteristic indicative of their monophyletic origin. Our survey of nonanthropoid primates and several archontan families indicates frontal fusion is widespread. It is most variable (fused, open or partially fused) inter‐ and intra‐specifically among strepsirhines. The frontal bone is more commonly fused in living lemuroids and indrioids than among lorisoids. It appears to be fused regularly among Eocene adapids. Among nonanthropoid haplorhines, the interfrontal is fused in Tarsius, even in neonates and invariably in adults, probably also in all fossil tarsiiforms preserving the frontal bone, and in the late Eocene protoanthropoid Rooneyia. The plesiadapiform pattern remains uncertain, but fusion is ubiquitous among living tree shrews, colugos and bats. Distributional evidence implies that interfrontal fusion was present in the last common ancestor (LCA) of haplorhine primates and possibly in the LCA of euprimates as well. Anthropoids, therefore, cannot be defined cladistically by interfrontal fusion, not out of concern for homoplasy but because it is probably a primitive feature inherited from other taxa related to anthropoids. Fusion of the large anthropoid frontal bone, which was extended anteriorly to roof the orbits and expanded laterally in connection with a wide forebrain in the LCA of anthropoids and protoanthropoids, may have been preadaptive to the evolution of the postorbital septum. The zygomatico‐frontal suture of the septum may provide an alternative mechanism for dissipating the calvarial strains of mastication formerly taken up by an open interfrontal suture. Anat Rec, 291:308–317, 2008. © 2008 Wiley‐Liss, Inc.
Recent Advances in Immobilized Metal Catalysts for Environmentally Benign Oxidation of Alcohols
Authors: Matsumoto Tsutomu , Ueno Masaharu , Wang Naiwei , Kobayashi Shū
Published: January 2008

One of the most significant organic transformations in catalyst technology is the selective oxidation of alcohols. The acceleration of catalyst discovery in this field contributes to the economic and environmental impact in the production of useful materials. Heterogeneous catalysts combined with environmentally benign oxidants, such as molecular oxygen and hydrogen peroxide, are major challenges of exploratory research in the oxidation of alcohols. A wide range of recoverable catalysts has now emerged for these oxidation reactions. In this Focus Review, we present an overview of recent developments in immobilized metal catalysts and evaluate the potential of transition metals in the heterogeneously catalyzed oxidation of alcohols.
Interindividual variability in acetaminophen sulfation by human fetal liver: Implications for pharmacogenetic investigations of drug‐induced birth defects
Authors: Adjei Araba A. , Gaedigk Andrea , Simon Stephen D. , Weinshilboum Richard M. , Leeder J. Steven
Published: January 2008

BACKGROUND:

Acetaminophen (APAP) use in early pregnancy has been associated with the risk of gastroschisis, a rare but serious congenital defect of the abdominal wall. The purpose of this study was to characterize the variability of APAP sulfation in a panel of human fetal livers and to identify the sulfotransferases (SULT) isoform(s) responsible for catalyzing that activity.

METHODS:

APAP sulfation was determined in a panel of human fetal (n = 73) and postnatal (n = 18) liver cytosol preparations and correlated with the catalytic activity of various SULT isoforms as determined using prototypic substrates and specific antibodies.

RESULTS:

Of 10 heterologously expressed SULT isoforms examined, SULT1A1, SULT1A3/4, SULT1E1, and SULT2A1 all catalyzed the formation of APAP sulfate with Km values of 2.4, 1.5, 1.9, and 3.7 mM, respectively. Catalytic activities for these four isoforms were expressed at varying levels in human fetal liver, and APAP sulfation was positively correlated with each of the four prototypic activities. Several regression and clustering approaches revealed that SULT1A3/4 was the primary determinant of prenatal APAP sulfation but that SULT1A1 or SULT1E1 were also major contributors in subsets of samples.

CONCLUSIONS:

The results of this study lead to the hypothesis that genetic variation in SULT1A3/4 represents a risk factor for the development of gastroschisis in the offspring of mothers exposed to APAP early in pregnancy. Interpretation of genetic association studies conducted to test this hypothesis will be complicated by the variable contributions of other SULTs toward APAP‐sulfate formation in individual subjects. Birth Defects Research (Part A), 2007. © 2007 Wiley‐Liss, Inc.
Outcome in transferred and nontransferred patients after primary percutaneous coronary intervention for ischaemic out‐of‐hospital cardiac arrest
Authors: Peels Hans O. , Jessurun Gillian A.J. , van der Horst Iwan C.C. , Arnold Alfons E.R. , Piers Lieuwe H. , Zijlstra Felix
Published: January 2008

Objective:

To evaluate the impact of transfer from a referral hospital to a center with primary percutaneous coronary intervention (PCI) facilities of ST‐segment elevation myocardial infarction (STEMI) patients after successful cardiopulmonary resuscitation (CPR).

Methods:

We studied all STEMI patients with successful CPR admitted to two centers after out‐of‐hospital cardiac arrest and CPR from January 2004 to December 2005. Subjects were divided in a transferred (PCI performed after referral from center without PCI facility) and nontransferred (PCI performed in hospital of admission, i.e. center with PCI facility) group.

Results:

A total of 44 patients were included. Mean age was 61 ± 13 year and 35 (80%) patients were male. Of all patients 16 (36%) were transferred for treatment. After treatment, the left ventricular function was preserved in 4 (25%) patients of the transferred group are compared with 17 (61%) of the nontransferred group (P = 0.024). In‐hospital mortality after follow‐up did not differ with 7 (44%) survivors in the transferred group versus 15 (54%) survivors in the nontransferred group (P = 0.76). Patients who did not survive were more often treated with endotracheal intubation (100% versus 71%, P= 0.019), had more often an occlusion of the proximal right coronary artery (37% versus 10%, P= 0.02), and higher glucose levels at admission (15.2 mmol/l ± 4.4 versus 11.5 mmol/l ± 4.2, P= 0.009).

Conclusion:

In conclusion, no difference in outcome was observed between nontransferred and transferred patients. Therefore, we suggest that transfer for primary PCI for STEMI patients after successful CPR should be considered. © 2008 Wiley‐Liss, Inc.
Fe2 and Fe4 Clusters Encapsulated in Vacant Polyoxotungstates: Hydrothermal Synthesis, Magnetic and Electrochemical Properties, and DFT Calculations
Authors: Pichon Céline , Dolbecq Anne , Mialane Pierre , Marrot Jérôme , Rivière Eric , Goral Monika , Zynek Monika , McCormac Timothy , Borshch Serguei A. , Zueva Ekaterina , Sécheresse Francis
Published: January 2008

While the reaction of [PW11O39]7− with first row transition‐metal ions Mn+ under usual bench conditions only leads to monosubstituted {PW11O39M(H2O)} anions, we have shown that the use of this precursor under hydrothermal conditions allows the isolation of a family of novel polynuclear discrete magnetic polyoxometalates (POMs). The hybrid asymmetric [FeII(bpy)3][PW11O39Fe2III(OH)(bpy)2]⋅12 H2O (bpy=bipyridine) complex (1) contains the dinuclear {Fe(μ‐O(W))(μ‐OH)Fe} core in which one iron atom is coordinated to a monovacant POM, while the other is coordinated to two bipyridine ligands. Magnetic measurements indicate that the FeIII centers in complex 1 are weakly antiferromagnetically coupled (J=−11.2 cm−1, H=−JS1S2) compared to other {Fe(μ‐O)(μ‐OH)Fe} systems. This is due to the long distances between the iron center embedded in the POM and the oxygen atom of the POM bridging the two magnetic centers, but also, as shown by DFT calculations, to the important mixing of bridging oxygen orbitals with orbitals of the POM tungsten atoms. The complexes [Hdmbpy]2[FeII(dmbpy)3]2[(PW11O39)2Fe4IIIO2(dmbpy)4]⋅14 H2O (2) (dmbpy=5,5′‐dimethyl‐2,2′‐bipyridine) and H2[FeII(dmbpy)3]2[(PW11O39)2Fe4IIIO2(dmbpy)4]⋅10 H2O (3) represent the first butterfly‐like POM complexes. In these species, a tetranuclear FeIII complex is sandwiched between two lacunary polyoxotungstates that are pentacoordinated to two FeIII cations, the remaining paramagnetic centers each being coordinated to two dmbpy ligands. The best fit of the χMT=f(T) curve leads to Jwb=−59.6 cm−1 and Jbb=−10.2 cm−1 (H=−Jwb(S1S2+S1S2*+S1*S2+S1*S2*)−Jbb(S2S2*)). While the Jbb value is within the range of related exchange parameters previously reported for non‐POM butterfly systems, the Jwb constant is significantly lower. As for complex 1, this can be justified considering FewO distances. Finally, in the absence of a coordinating ligand, the dimeric complex [N(CH3)4]10[(PW11O39FeIII)2O]⋅12 H2O (4) has been isolated. In this complex, the two single oxo‐bridged FeIII centers are very strongly antiferromagnetically coupled (J=−211.7 cm−1, H=−JS1S2). The electrochemical behavior of compound 1 both in dimethyl sulfoxide (DMSO) and in the solid state is also presented, while the electrochemical properties of complex 2, which is insoluble in common solvents, have been studied in the solid state.
The geometric minimum action method: A least action principle on the space of curves
Authors: Heymann Matthias , Vanden‐Eijnden Eric
Published: January 2008

Freidlin‐Wentzell theory of large deviations for the description of the effect of small random perturbations on dynamical systems is exploited as a numerical tool. Specifically, a numerical algorithm is proposed to compute the quasi‐potential in the theory, which is the key object to quantify the dynamics on long time scales when the effect of the noise becomes ubiquitous: the equilibrium distribution of the system, the pathways of transition between metastable states and their rate, etc., can all be expressed in terms of the quasi‐potential. We propose an algorithm to compute these quantities called the geometric minimum action method (gMAM), which is a blend of the original minimum action method (MAM) and the string method. It is based on a reformulation of the large deviations action functional on the space of curves that allows one to easily perform the double minimization of the original action required to compute the quasi‐potential. The theoretical background of the gMAM in the context of large deviations theory is discussed in detail, as well as the algorithmic aspects of the method. The gMAM is then illustrated on several examples: a finite‐dimensional system displaying bistability and modeled by a nongradient stochastic ordinary differential equation, an infinite‐dimensional analogue of this system modeled by a stochastic partial differential equation, and an example of a bistable genetic switch modeled by a Markov jump process. © 2007 Wiley Periodicals, Inc.
Stability of peakons for the Degasperis‐Procesi equation
Authors: Lin Zhiwu , Liu Yue
Published: January 2008

The Degasperis‐Procesi equation can be derived as a member of a one‐parameter family of asymptotic shallow‐water approximations to the Euler equations with the same asymptotic accuracy as that of the Camassa‐Holm equation. In this paper, we study the orbital stability problem of the peaked solitons to the Degasperis‐Procesi equation on the line. By constructing a Lyapunov function, we prove that the shapes of these peakon solitons are stable under small perturbations. © 2007 Wiley Periodicals, Inc.
Effectiveness of sputum cytology using ThinPrep® method for evaluation of lung cancer
Authors: Choi Yoo‐Duk , Han Chang‐Woo , Kim Jo‐Heon , Oh In‐Jae , Lee Ji‐Shin , Nam Jong‐Hee , Juhng Sang‐Woo , Park Chang‐Soo
Published: January 2008

Sputum cytology is a non‐invasive test for evaluating lung cancer. But, its sensitivity is yet lower than other tests. ThinPrep® (TP) is an automated cytopreparatory method that has mucolytic and hemolysing effects. We compared 955 sputum specimens that were prepared by both TP and conventional preparation (CP). The nuclear details were more preserved on the TP slides, while the obscuring materials were more eliminated on the TP slides as compared with the CP. The cytologic rates of TP were 2.7% unsatisfactory, 4.7% normal, 81.0% benign, 2.4% suspicious, and 9.1% malignancy. The rates of CP were 7.9% unsatisfactory, 1.6% normal, 84.8% benign, 1.8% suspicious, and 4.0% malignancy. The false negative rates, relative to the histologic data for 352 cases which the tissue diagnosis was available, were 49.6% (TP) and 69.4% (CP). Sputum cytology using the TP method improves the diagnostic accuracy for evaluating lung cancer by reducing the unsatisfactory and false‐negative rates. Diagn. Cytopathol. 2008;36:167–171. © 2008 Wiley‐Liss, Inc.
Cystitis glandularis
Authors: Pantanowitz Liron , Otis Christopher N.
Published: January 2008

The cytologic finding of glandular cells in a urine specimen is unusual. The differential diagnosis ranges from benign conditions such as cystitis glandularis to adenocarcinoma. Glandular cells of cystitis glandularis with intestinal metaplasia have a bland cytologic appearance. If detected in a urine cytology specimen colonic metaplasia can be reported. Diagn. Cytopathol. 2008;36:181‐182. © 2008 Wiley‐Liss, Inc.
Bilateral carotid body tumor: The role of fine‐needle aspiration biopsy in the preoperative diagnosis
Authors: Rosa Marilin , Sahoo Sunati
Published: January 2008

Carotid body (CB) is a round to ovoid or flattened structure situated within the adventitia of the common carotid artery bifurcation on both sides of the neck. CB contains two basic types of cells: chief cells (or glomus type 1) and sustentacular cells (glomus type 2). Carotid body tumor (CBT) or paraganglioma arises from the chief cells of the carotid body. The diagnosis of CBT is typically made with radiological studies. Fine needle aspiration biopsy (FNAB) is seldom requested for this purpose due to rare but dreadful reported complications such as hemorrhage and damage to the carotid artery. In this report we discuss the cytological findings of a malignant CBT diagnosed by FNAB in a 22 year‐old female. Diagn. Cytopathol. 2008;36:178–180. © 2008 Wiley‐Liss, Inc.
Fine‐needle aspiration biopsy of disseminated sporotrichosis: A case report
Authors: Gerhard Renê , de Moscoso Patrícia Carrasco , Gabbi Tatiana Villas Boas , Valente Neusa Yuriko Sakai
Published: January 2008

In this report, we describe a case of disseminated sporotrichosis that was diagnosed by fine–needle aspiration biopsy (FNAB). The cytologic smears exhibited a large number of macrophages, few polymorphonuclear neutrophils and numerous round or oval, sometimes elongated, isolated and scattered yeast‐like structures localized extracellularly or inside macrophages. These structures were clearly visualized by Giemsa and Papanicolaou methods. Cultures from skin biopsy material revealed fungal colonies which were subsequently identified as Sporothrix schenckii. The cytologic aspects, the correlation with histologic findings and the differential cytologic diagnosis were reviewed. Diagn. Cytopathol. 2008;36:174–177. © 2008 Wiley‐Liss, Inc.
Effectiveness of the ThinPrep Imaging System: Clinical experience in a low risk screening population
Authors: Papillo Jacalyn L. , St. John Timothy L. , Leiman Gladwyn
Published: January 2008

The Cytyc ThinPrep Imaging System was FDA approved based on a multi‐institutional clinical trial, in which the HSIL+ prevalence rate was 0.7%. This study determines the effectiveness of the Imager in clinical practice at an academic medical center with a historical HSIL+ rate of 0.25%. Cytological interpretations were compared for two 12‐month periods pre‐ and post‐Imager implementation. Data was compiled by cytologic diagnoses, and variations in prevalence rates were analyzed for statistical significance. Interpretations of ASC‐US, ASC‐H, and LSIL were correlated with Digene Hybrid Capture2 High Risk HPV DNA testing; interpretations of ASC‐H, LSIL, and HSIL+ were correlated with subsequent surgical follow‐up. ASC‐US, ASC‐H, and LSIL detection rates increased 34, 48, and 29%, respectively, with the Imager (P < 0.001); whereas the detection of HSIL increased 24% (P < 0.051). Surgical correlation revealed no statistical differences in the positive predictive value (PPV) for ASC‐H and LSIL. However, an increase in the PPV of HSIL was found (P < 0.05). High risk HPV results were lower for ASC‐US (P < 0.001), but statistically equivalent for ASC‐H and LSIL. Results of surgical correlation and HPV testing validated an increase in detection rates of ASC‐H, LSIL, and HSIL, as well as increased PPV of HSIL with the ThinPrep Imaging System. Diagn. Cytopathol. 2008;36:155–160. © 2008 Wiley‐Liss, Inc.
Polymer‐Immobilized Pyrrolidine‐Based Chiral Ionic Liquids as Recyclable Organocatalysts for Asymmetric Michael Additions to Nitrostyrenes under Solvent‐Free Reaction Conditions
Authors: Li Pinhua , Wang Lei , Wang Min , Zhang Yicheng
Published: January 2008

A polymer immobilized pyrrolidine‐based chiral ionic liquid 5a was synthesized and was found to be a highly efficient catalyst for the Michael additions of ketones and aldehydes to nitrostyrenes, which afforded the corresponding adducts in good yields (up to 97 %), excellent enantioselectivities (up to >99 % ee) and high diastereoselectivities (up to >99:1 dr) under solvent‐free reaction conditions. In addition, the catalyst 5a could be reused at least eight times without a significant loss of its catalytic activity and stereoselectivity.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Continuous Flow Reactors, a Tool for the Modern Synthetic Chemist
Authors: Wiles Charlotte , Watts Paul
Published: January 2008

The competitive nature of the chemical industry means that researchers involved in product development and lead compound generation are under continued pressure to identify, and develop, promising programmes of research in order to secure vital intellectual property. The potential of a compound, however, depends not only on structural complexity, but also on the ability to prepare the compound via a scalable synthetic pathway. Consequently, micro reaction and continuous flow technologies have captured the attention of the modern synthetic chemist as they enable reactions to beperformed with an unprecedented level of control, affording excellent transferability between laboratory based investigations and subsequent production scales. With these features in mind, this Microreview focuses on recent developments made in the field of micro reaction technology, highlighting the advantages associated with its use through the synthesis of a diverse array of molecules.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis, Optical Properties and Magnetic Studies of 2,6‐Bis(pyrazolylmethyl)pyridine Functionalized with Two Nitronyl Nitroxide Radicals
Authors: Zoppellaro Giorgio , Geies Ahmed , Andersson K. Kristoffer , Enkelmann Volker , Baumgarten Martin
Published: January 2008

The synthesis, optical properties, spin‐polarization path and magnetic ground‐state studies of a novel nitronyl nitroxide biradical system based on the 2,6‐bis(pyrazolylmethyl)pyridine unit is reported. Besides the presence of σ conjugation and a non‐alternant pathway for spin polarization through the core as a coupling unit, the through‐bond ferromagnetic interaction between spin carriers, although weak (0.06 cm–1 < ΔEST = 2J/kB < 0.6 cm–1), is preserved. It vanishes (2J/kB ≈ 0) upon coordination with Zn2+ metal ions, but is restored upon Zn2+ depletion with EDTA. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Statistical evaluation of mobility curves of univalent weak acids
Authors: Šlampová Andrea , Boček Petr
Published: January 2008

This paper brings a new rigorous and complete statistical approach to the data processing of the mobility curves of univalent weak acids. It is based on a fundamental equation for the mobility curve, on applying the mathematical principle of the best fit, derivation of the related nonlinear equation and finding the mathematical solution of it which gives the best estimates of the mobility curve parameters. The mathematical procedure presented here does not impose any limitations upon the numerical data used, i.e., the experimental values of mobilities and pH may be real numbers (positive, negative, zero). Further, rigorous explicit statistical formulas are derived for SDs of effective mobility, dissociation constant, and ionic mobility of fully ionized anion in question.