bluuebunny/crossref_metadata_2025 huggingface dataset:
Sequential onset of presynaptic molecules during olfactory sensory neuron maturation
Authors: Marcucci Florencia , Zou Dong‐Jing , Firestein Stuart
Published: May 2009

Differentiated olfactory sensory neurons express specific presynaptic proteins, including enzymes involved in neurotransmitter transport and proteins involved in the trafficking and release of synaptic vesicles. Studying the regulation of these presynaptic proteins will help to elucidate the presynaptic differentiation process that ultimately leads to synapse formation. It has been postulated that the formation of a synapse between the axons of the sensory neurons and the dendrites of second order neurons in the olfactory bulb is a critical step in the processes of sensory neuron maturation. One approach to study the relationship between synaptogenesis and sensory neuron maturation is to examine the expression patterns of synaptic molecules through the olfactory neuron lineage. To this end we designed specific in situ hybridization probes to target messengers for proteins involved in presynaptic vesicle release. Our findings show that, as they mature, mouse olfactory neurons sequentially express specific presynaptic genes. Furthermore, the different patterns of expression of these presynaptic genes suggest the existence of discrete steps in presynaptic development: genes encoding proteins involved in scaffolding show an early onset of expression, whereas expression of genes encoding proteins involved in the regulation of vesicle release starts later. In particular, the signature molecule for glutamatergic neurons vesicle glutamate transporter 2 shows the latest onset of expression. In addition, contact with the targets in the olfactory bulb is not controlling presynaptic protein gene expression, suggesting that olfactory sensory neurons follow an intrinsic program of development. J. Comp. Neurol. 516:187–198, 2009. © 2009 Wiley‐Liss, Inc.
Sexual dimorphism and hormone responsiveness in the spinal cord of the socially monogamous prairie vole (Microtus ochrogaster)
Authors: Holmes Melissa M. , Musa Mutaz , Lonstein Joseph S. , Monks D. Ashley
Published: May 2009

Prairie voles (Microtus ochrogaster) are exceptional among rodents in that many aspects of their brain and behavior are not masculinized by exogenous aromatizable androgens. However, the sexually differentiated endpoints studied to date rely on estrogenic mechanisms in other mammals. We examined whether sexual differentiation of an androgen receptor‐dependent sex difference would be similarly distinct in prairie voles. Male mammals have more and larger motoneurons projecting to perineal muscles than do females. This sex difference normally arises from males' perinatal androgen exposure and can be eliminated by treating developing females with androgens. Gross dissection revealed bulbospongiosus muscles in adult male, but not female, prairie voles. Retrograde tracing from males' bulbocavernosus muscles and the external anal sphincter from both sexes revealed sexually dimorphic populations of labeled motoneurons in the ventral horn of the lumbar spinal cord. Similar to other rodents, males had twice as many motoneurons as females, although no sex difference in motoneuron size was detected. Unexpectedly, prenatal or early postnatal exposure to testosterone propionate had no effect on adult females' motoneuron number or size. In adulthood, gonadectomy alone or followed by chronic testosterone treatment also had no effect on females' motoneuron size or number, although castration reduced motoneuron size in males. Comparing gonadally intact weanlings confirmed that the sex difference in motoneuron number exists before adulthood. As with some other sexually dimorphic traits, and perhaps related to their unique social organization, sexual differentiation of the prairie vole spinal cord differs from that found in most other laboratory rodents. J. Comp. Neurol. 516:117–124, 2009. © 2009 Wiley‐Liss, Inc.
Vagal gustatory reflex circuits for intraoral food sorting behavior in the goldfish: Cellular organization and neurotransmitters
Authors: Ikenaga Takanori , Ogura Tatsuya , Finger Thomas E.
Published: May 2009

The sense of taste is crucial in an animal's determination as to what is edible and what is not. This gustatory function is especially important in goldfish, who utilize a sophisticated oropharyngeal sorting mechanism to separate food from substrate material. The computational aspects of this detection are carried out by the medullary vagal lobe, which is a large, laminated structure combining elements of both the gustatory nucleus of the solitary tract and the nucleus ambiguus. The sensory layers of the vagal lobe are coupled to the motor layers via a simple reflex arc. Details of this reflex circuit were investigated with histology and calcium imaging. Biocytin injections into the motor layer labeled vagal reflex interneurons that have radially directed dendrites ramifying within the layers of primary afferent terminals. Axons of reflex interneurons extend radially inward to terminate onto both vagal motoneurons and small, GABAergic interneurons in the motor layer. Functional imaging shows increases in intracellular Ca++ of vagal motoneurons following electrical stimulation in the sensory layer. These responses were suppressed under Ca++‐free conditions and by interruption of the axons bridging between the sensory and motor layers. Pharmacological experiments showed that glutamate acting via (±)‐α‐amino‐3‐hydroxy‐ 5‐ethylisoxazole‐4‐propioinc acid (AMPA)/kainate and N‐methyl‐D‐aspartic acid (NMDA) receptors mediate neurotransmission between reflex interneurons and vagal motoneurons. Thus, the vagal gustatory portion of the viscerosensory complex is linked to branchiomotor neurons of the pharynx via a glutamatergic interneuronal system. J. Comp. Neurol. 516:213–225, 2009. © 2009 Wiley‐Liss, Inc.
Immunotoxin‐induced ablation of melanopsin retinal ganglion cells in a non‐murine mammalian model
Authors: Ingham Elizabeth S. , Günhan Emine , Fuller Patrick M. , Fuller Charles A.
Published: May 2009

In mammals, non‐image‐forming visual functions, including circadian photoentrainment and the pupillary light reflex, are thought to be mediated by the combination of rods, cones, and the melanopsin‐expressing intrinsically photosensitive retinal ganglion cells (ipRGCs). Although several genetic models have been developed to clarify the individual roles of the rod, cone, and ipRGC systems in mediating non‐image visual function, assessing the in vivo role(s) of the ipRGCs has been complicated by the possibility of ontogenetic issues in these genetically modified animal models. In the present study, we describe the development and validation of an immunotoxin that specifically targets the ipRGC population in the mature mammalian retina. This ipRGC immunotoxin, consisting of saporin conjugated to a melanopsin polyclonal antibody, was evaluated with respect to its effectiveness and specificity in depleting the ipRGC population in the fully developed rat retina. The results showed that the ipRGC toxin rapidly and permanently depleted ∼70% of the ipRGC population, without inducing appreciable changes in the cell number or morphology of any of the non‐melanopsin‐containing retinal cell populations investigated. These findings suggest that the newly developed ipRGC immunotoxin provides a potent method for achieving relatively rapid, permanent, and selective depletion of the ipRGC population in a non‐murine model system. The development of this ipRGC‐ablation method is the next step in elucidating the role of ipRGCs in mediating non‐visual and circadian light‐resetting responses in a wide range of non‐murine mammalian models. J. Comp. Neurol. 516:125–140, 2009. © 2009 Wiley‐Liss, Inc.
Thymidine analog methods for studies of adult neurogenesis are not equally sensitive
Authors: Leuner Benedetta , Glasper Erica R. , Gould Elizabeth
Published: May 2009

Adult neurogenesis is often studied by labeling new cells with the thymidine analog bromodeoxyuridine (BrdU) and using immunohistochemical methods for their visualization. Using this approach, considerable variability has been reported in the number of new cells produced in the dentate gyrus of adult rodents. We examined whether immunohistochemical methods, including BrdU antibodies from different vendors (Vector, BD, Roche, Dako, Novocastra, and Accurate) and DNA denaturation pretreatments alter the quantitative and qualitative patterns of BrdU labeling. We also compared the sensitivity and specificity of BrdU with two other thymidine analogs, iododeoxyuridine (IdU) and chlorodeoxyuridine (CldU). We found that the number of BrdU‐labeled cells in the dentate gyrus of adult rats was dependent on the BrdU antibody used but was unrelated to differences in antibody penetration. Even at a higher concentration, some antibodies (Vector and Novocastra) stained fewer cells. A sensitive BrdU antibody (BD) was specific for dividing cells; all BrdU‐labeled cells stained for Ki67, an endogenous marker of cell proliferation. We also observed that DNA denaturation pretreatments affected the number of BrdU‐labeled cells and staining intensity for a marker of neuronal differentiation, NeuN. Finally, we found that IdU and CldU, when used at molarities comparable to those that label the maximal number of cells with BrdU, are less sensitive. These data suggest that antibody and thymidine analog selection, as well as the staining procedure employed, can affect the number of newly generated neurons detected in the adult brain, thus providing a potential explanation for some of the variability in the adult neurogenesis literature. J. Comp. Neurol. 517:123–133, 2009. © 2009 Wiley‐Liss, Inc.
Exciton Diffusion in Polyfluorene Copolymer Thin Films: Kinetics, Energy Disorder and Thermally Assisted Hopping
Authors: Dias Fernando B. , Kamtekar Kiran T. , Cazati Thiago , Williams Geoff , Bryce Martin R. , Monkman Andrew P.
Published: May 2009

A series of {(9,9‐dioctylfluorene)0.7−x‐(dibenzothiophene‐S,S‐dioxide)0.3‐[4,7‐bis(2‐thienyl)‐2,1,3‐benzothiadiazole]x} (PFS30‐TBTx), where x represents the minor percentage of the red emitter 4,7‐bis(2‐thienyl)‐2,1,3‐benzothiadiazole (TBT) randomly incorporated into the copolymer backbone, is investigated in order to follow the energy transfer from PFS30 to TBT moieties. The emission of the donor poly[(9,9‐dioctylfluorene)0.7‐(dibenzothiophene‐S,S‐dioxide)0.3 identified by PFS30 and peaking at 450 nm, is clearly quenched by the presence of the red TBT chromophore emitting at 612 nm, with an isoemissive point observed when the spectra are collected as a function of temperature. A plot of the ratio between the TBT and PFS30 emissions as a function of the reciprocal of temperature gives a clear linear trend between 290 and 200 K, with an activation energy of 20 meV and showing a turn over to a non‐activated regime below 200 K. Picosecond time‐resolved fluorescence decays collected at the PFS30 and TBT emission wavelengths, show a decay of the PFS30 emission and a fast build‐in, followed by a decay, of the TBT emission, confirming that the population of the TBT excited state occurs during the PFS30 lifetime(∼600 ps). The population of the TBT excited state occurs on a time regime around 150 ps at 290 K, showing an energy barrier of 20 meV that turns over to a non‐activated regime below 200 K in clear agreement with the steady‐state data. The origin of the activation barrier is attributed to the presence of physical and energetic disorder, affected by fast thermal fluctuations that dynamically change the energy landscape and control the exciton migration through the polymer density of states.
Identification of genes expressed preferentially in the developing peripheral margin of the optic cup
Authors: Trimarchi Jeffrey M. , Cho Seo‐Hee , Cepko Constance L.
Published: May 2009

Specification of the peripheral optic cup by Wnt signaling is critical for formation of the ciliary body/iris. Identification of marker genes for this region during development provides a starting point for functional analyses. During transcriptional profiling of single cells from the developing eye, two cells were identified that expressed genes not found in most other single cell profiles. In situ hybridizations demonstrated that many of these genes were expressed in the peripheral optic cup in both early mouse and chicken development, and in the ciliary body/iris at subsequent developmental stages. These analyses indicate that the two cells probably originated from the developing ciliary body/iris. Changes in expression of these genes were assayed in embryonic chicken retinas when canonical Wnt signaling was ectopically activated by CA‐β‐catenin. Twelve ciliary body/iris genes were identified as upregulated following induction, suggesting they are excellent candidates for downstream effectors of Wnt signaling in the optic cup. Developmental Dynamics 238:2327–2339, 2009. © 2009 Wiley‐Liss, Inc.
Cytoplasmic localization of oocyte‐specific variant of porcine DNA methyltransferase‐1 during early development
Authors: Jeong Young Sun , Oh Keon Bong , Park Jung Sun , Kim Ji‐Su , Kang Yong‐Kook
Published: May 2009

DNA methyltransferase‐1 (Dnmt1) is involved in the maintenance of genomic methylation patterns. Rather than full‐length Dnmt1, mouse oocytes have a truncated variant called Dnmt1o. Immunofluorescence data showed that Dnmt1o localized to the cytoplasm, but this has not been confirmed using more direct methods. The cytoplasmic localization of Dnmt1o has been assigned to the main cause of global DNA demethylation in early mouse embryos. We studied localization of Dnmt1o in mouse and pig embryos. We identified pig Dnmt1o protein and its transcript with unique 5′‐end sequence. Physically separating mouse and pig 2‐cell embryos into their nuclear and cytoplasmic components demonstrated that Dnmt1o of both species localized to the cytoplasm. Cloned pig embryos had Dnmt1o as the main form, with no indication of somatic Dnmt1. These findings indicate that Dnmt1o is cytoplasmic during early development; its presence in both pig and mouse embryos further suggests that Dnmt1o is conserved in mammals. Developmental Dynamics 238:1666–1673, 2009. © 2009 Wiley‐Liss, Inc.
Analysis of heart valve development in larval zebrafish
Authors: Martin Richard Tyler , Bartman Thomas
Published: May 2009

Malformations of the cardiac endocardial cushions (ECs) and valves are common congenital dysmorphisms in newborn infants. Many regulators of EC development have been identified, but the process of valve maturation is less well understood. Zebrafish have been used to understand cardiogenesis through 6 days postfertilization, yet mature heart valves are not present at this stage. By analyzing valve development in larval zebrafish, we identify that valve development proceeds in two phases. Valve elongation occurs through 16 dpf independently of localized cell division. Valve maturation then ensues, resulting from deposition of extracellular matrix and thickening of the valves. Whereas elongation is consistent between larvae, maturation varies based on larval size, suggesting that maturation occurs in response to mechanical forces. Taken together, our studies indicate that zebrafish valve morphogenesis occurs in the larval period, and that zebrafish may provide a unique opportunity to study epigenetic mechanisms leading to human congenital valvular disease, when studied at the appropriate developmental stages. Developmental Dynamics 238:1796–1802, 2009. © 2009 Wiley‐Liss, Inc.
Synthesis and Optical Properties of Regioisomerically Pure Alkynyl‐Bridged Bis(phthalocyanines)
Authors: García‐Frutos Eva M. , de la Torre Gema , Vázquez Purificación , Shirk James S. , Torres Tomás
Published: May 2009

PbII ethynyl‐ and butadiynyl‐bridged bis(phthalocyaninates) 1a–d, peripherally functionalized with n‐butoxy moieties, have been synthesized by using Pd‐catalyzed cross‐coupling methodologies. Preliminary open‐aperture Z‐scan experiments with nanosecond pulses at 550 nm on solutions of PbII bis(phthalocyaninates) 1b and 1d show strong reduction of the transmission at high intensities, although an irreversible optical behaviour is observed at the experimental time scale. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Calibration of POD reduced‐order models using Tikhonov regularization
Authors: Cordier L. , El Majd B. Abou , Favier J.
Published: May 2009

In this paper we compare various methods of calibration that can be used in practice to improve the accuracy of reduced‐order models based on proper orthogonal decomposition. The bench mark configuration retained corresponds to a case of relatively simple dynamics: a two‐dimensional flow around a cylinder for a Reynolds number of 200. We generalize to the first and second‐order the method of calibration based on Tikhonov regularization recently used in (Physica D: Nonlinear Phenom. 2009; 238:416–427). Finally, we show that for this flow configuration this procedure is the most effective in terms of reduction of errors. Copyright © 2009 John Wiley & Sons, Ltd.
DTNBP1 is associated with imaging phenotypes in schizophrenia
Authors: Narr Katherine L. , Szeszko Philip R. , Lencz Todd , Woods Roger P. , Hamilton Liberty S. , Phillips Owen , Robinson Delbert , Burdick Katherine E. , DeRosse Pamela , Kucherlapati Raju , Thompson Paul M. , Toga Arthur W. , Malhotra Anil K. , Bilder Robert M.
Published: May 2009

Dystrobrevin binding protein 1 (DTNBP1) has been identified as putative schizophrenia susceptibility gene, but it remains unknown whether polymorphisms relate to altered cerebral structure. We examined relationships between a previously implicated DTNBP1 risk variant [P1578] and global and segmented brain tissue volumes and regional cortical thickness in schizophrenia (n = 62; 24 risk carriers) and healthy subjects (n = 42; 11 risk carriers), across ethnic groups and within Caucasians. Schizophrenia patients showed similar brain volumes, but significantly reduced brain‐size adjusted gray matter and CSF volumes and cortical thinning in a widespread neocortical distribution compared to controls. DTNBP1 risk was found associated with reduced brain volume, but not with tissue sub‐compartments. Cortical thickness, which was weakly associated with brain size, showed regional variations in association with genetic risk, although effects were dominated by highly significant genotype by diagnosis interactions over broad areas of cortex. Risk status was found associated with regional cortical thinning in patients, particularly in temporal networks, but with thickness increases in controls. DTNBP1 effects for brain volume and cortical thickness appear driven by different neurobiological processes. Smaller brain volumes observed in risk carriers may relate to previously reported DTNBP1/cognitive function relationships irrespective of diagnosis. Regional cortical thinning in patient, but not in control risk carriers, may suggest that DTNBP1 interacts with other schizophrenia‐related risk factors to affect laminar thickness. Alternatively, DTNBP1 may influence neural processes for which individuals with thicker cortex are less vulnerable. Although DTNBP1 relates to cortical thinning in schizophrenia, morphological changes in the disorder are influenced by additional genetic and/or environmental factors. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Directional anisotropy of motion responses in retinotopic cortex
Authors: Raemaekers Mathijs , Lankheet Martin J.M. , Moorman Sanne , Kourtzi Zoe , van Wezel Richard J.A.
Published: May 2009

Recently, evidence has emerged for a radial orientation bias in early visual cortex. These results predict that in early visual cortex a tangential bias should be present for motion direction. We tested this prediction in a human imaging study, using a translating random dot pattern that slowly rotated its motion direction 360° in cycles of 54 s. In addition, polar angle and eccentricity mapping were performed. This allowed the measurement of the BOLD response across the visual representations of the different retinotopic areas. We found that, in V1, V2, and V3, BOLD responses were consistently enhanced for centrifugal and centripetal motion, relative to tangential motion. The relative magnitude of the centrifugal and centripetal response biases changed with visual eccentricity. We found no motion direction biases in MT+. These results are in line with previously observed anisotropies in motion sensitivity across the visual field. However, the observation of radial motion biases in early visual cortex is surprising considering the evidence for a radial orientation bias. An additional experiment was performed to resolve this apparent conflict in results. The additional experiment revealed that the observed motion direction biases most likely originate from anisotropies in long range horizontal connections within visual cortex. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
The association between −1304T>G polymorphism in the promoter of MKK4 gene and the risk of sporadic colorectal cancer in southern Chinese population
Authors: Wei Yisheng , Wang Lei , Lan Ping , Zhao Hongjun , Pan Zhizhong , Huang Jun , Lu Jiachun , Wang Jianping
Published: May 2009

MKK4 (mitogen‐activated protein kinase kinase 4, NM_003010.2), which belongs to the mitogen‐activated protein kinase pathways, possesses functions in tumorigenesis. We hypothesized the genetic variants in MKK4 gene may alter its functions and thus cancer risk. In current hospital‐based case‐control study of 706 patients with sporadic colorectal cancer (CRC) and 723 sex‐age–frequency‐matched control subjects in a southern Chinese population, we genotyped two polymorphisms of MKK4 promoter (i.e., −1304T>G, rs3826392 and −1044A>T, rs3809728) and assessed their associations with the risk of sporadic CRC. Compared with −1304TT genotypes, −1304TG had a significantly decreased risk of CRC (adjusted odds ratios [OR] = 0.56; 95% CI = 0.44–0.72; p = 3.53 × 10−6), the −1304GG carriers had a further decreased risk of CRC (OR = 0.40; 95% CI = 0.23–0.70; p = 1.32 × 10−3), and there was a significant trend for an allele dose effect on risk of CRC (ptrend = 2.64 × 10−7). The decreased risk associated with −1304G variant genotypes (i.e., TG+GG) was more pronounced in the subjects older than 60 years (adjusted OR = 0.41; 95% CI = 0.29–0.57; p = 2.25 × 10−7), in ever drinkers (adjusted OR = 0.41; 95% CI = 0.28–0.59; p = 2.42 × 10−6). The age and alcohol drinking status interacted with −1304G variant genotypes on reducing cancer risk (p values for interaction were 0.015 and 0.043, respectively). Western blotting analysis showed that the levels of Mkk4 protein in sporadic CRC neoplastic tissues were significantly higher in the carriers of −1304G variant genotypes than that in those with −1304TT genotypes. However, no significant association was observed between −1044A>T polymorphism and risk of CRC. To the best of our knowledge, this is the first study of genetic variants in MKK4 and cancer susceptibility. Larger studies are needed to validate our findings. © 2009 UICC
Prospects for pluripotent stem cell‐derived cardiomyocytes in cardiac cell therapy and as disease models
Authors: Freund Christian , Mummery Christine L.
Published: May 2009

The derivation of embryonic stem cells (hESC) from human embryos a decade ago started a new era in perspectives for cell therapy as well as understanding human development and disease. More recently, reprogramming of somatic cells to an embryonic stem cell‐like state (induced pluripotent stem cells, iPS) presented a new milestone in this area, making it possible to derive all cells types from any patients bearing specific genetic mutations. With the development of efficient differentiation protocols we are now able to use the derivatives of pluripotent stem cells to study mechanisms of disease and as human models for drug and toxicology testing. In addition derivatives of pluripotent stem cells are now close to be used in clinical practice although for the heart, specific additional challenges have been identified that preclude short‐term application in cell therapy. Here we review techniques presently used to induce differentiation of pluripotent stem cells into cardiomyocytes and the potential these cells have as disease models and for therapy. J. Cell. Biochem. 107: 592–599, 2009. © 2009 Wiley‐Liss, Inc.
A simple construction of representable relation algebras with non‐representable completions
Authors: Ahmed Tarek Sayed
Published: May 2009

We give a simple new construction of representable relation algebras with non‐representable completions. Using variations on our construction, we show that the elementary closure of the class of completely representable relation algebras is not finitely axiomatizable (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Archimedean classes in integral commutative residuated chains
Authors: Horčík Rostislav , Montagna Franco
Published: May 2009

This paper investigates a quasi‐variety of representable integral commutative residuated lattices axiomatized by the quasi‐identity resulting from the well‐known Wajsberg identity (p → q) → q ≤ (q → p) → p if it is written as a quasi‐identity, i. e., (p → q) → q ≈ 1 ⇒ (q → p) → p ≈ 1. We prove that this quasi‐identity is strictly weaker than the corresponding identity. On the other hand, we show that the resulting quasi‐variety is in fact a variety and provide an axiomatization. The obtained results shed some light on the structure of Archimedean integral commutative residuated chains. Further, they can be applied to various subvarieties of MTL‐algebras, for instance we answer negatively Hájek's question asking whether the variety of ΠMTL‐algebras is generated by its Archimedean members (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fuzzy topology representation for MV‐algebras
Authors: Zhang Jialu , Chen Quanfa
Published: May 2009

Let M be an MV‐algebra and ΩM be the set of all σ ‐valuations from M into the MV‐unit interval. This paper focuses on the characterization of MV‐algebras using σ ‐valuations of MV‐algebras and proves that a σ ‐complete MV‐algebra is σ ‐regular, which means that a ≤ b if and only if v (a) ≤ v (b) for any v ∈ ΩM. Then one can introduce in a natural way a fuzzy topology δ on ΩM. The representation theorem forMV‐algebras is established by means of fuzzy topology. Some properties of fuzzy topology δ and its cut topology U are investigated (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Micromechanical models of the strength of a sandstone
Authors: Dormieux L. , Jeannin L. , Bemer E. , Le T. H. , Sanahuja J.
Published: May 2009

In this paper, the strength of a sandstone is determined from a micromechanical approach. The microstructure of the rock is described as a porous polycrystal. A von Mises criterion is used for the strength of the solid grains. The grains are surrounded by Mohr–Coulomb interfaces describing the cement phase. The macroscopic strength of the polycrystal is determined by means of nonlinear homogenization techniques. The failure mechanism of the grains is assumed to be ductile. It is combined with a failure mechanism of the interfaces, which is successively assumed to be ductile and brittle. The theoretical predictions are then compared with the experimental data. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis, characterization, and electroluminescent performance of a novel copolyfluorene containing pendant crown ether groups
Authors: Yu Juin‐Meng , Chen Yun
Published: May 2009

Copolyfluorene PFC containing pendant crown ether moieties was prepared by the palladium‐catalyzed Suzuki coupling reaction. The photo‐physical and electrochemical properties were investigated by absorption, photoluminescence (PL) spectroscopy, and cyclic voltammetry to elucidate the influence of the crown ether groups. In film state, its PL spectra (peaked at 430 and 452 nm) show noticeable red‐shift relative to 423 and 448 nm of poly(9,9‐dihexylfluorene) (PF). Thermal annealing leads to appearance of new emission at about 520 nm which has been attributed to formation of excimer. The highest occupied molecular orbital and lowest unoccupied molecular orbital levels of PFC were estimated to be −5.68 and −2.65 eV which contributed to balanced charges injection. Double‐layer electroluminescent device using PFC as emitting layer (ITO/PEDOT:PSS/PFC/Ca/Al) revealed maximum luminance (7910 cd/m2) and maximum luminance efficiency (2.3 cd/A) superior to those of PF device (860 cd/m2, 0.29 cd/A). Moreover, inserting a PFC layer between the PF emitting layer and calcium cathode led to reduced turn‐on voltage (4.1 V), much lower than 7.1 and 6.6 V of the double‐layer PFC and PF devices, respectively, and enhanced device performance (2800 cd/m2 and 0.53 cd/A). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2985–2995, 2009
One‐pot synthesis of ABC miktoarm star terpolymers by coupling ATRP, ROP, and click chemistry techniques
Authors: Zhang Yanfeng , Li Changhua , Liu Shiyong
Published: May 2009

We report on the one‐pot synthesis of well‐defined ABC miktoarm star terpolymers consisting of poly(2‐(dimethylamino)ethyl methacrylate), poly(ε‐caprolactone), and polystyrene or poly(ethylene oxide) arms, PS(‐b‐PCL)‐b‐PDMA and PEO (‐b‐PCL)‐b‐PDMA, taking advantage of the compatibility and mutual tolerability of reaction conditions (catalysts and monomers) employed for atom transfer radical polymerization (ATRP), ring‐opening polymerization (ROP), and click reactions. At first, a novel trifunctional core molecule bearing alkynyl, hydroxyl group, and bromine moieties, alkynyl(OH)Br, was synthesized via the esterification reaction of 5‐ethyl‐5‐hydroxymethyl‐2,2‐dimethyl‐1,3‐dioxane with 4‐oxo‐4‐(prop‐2‐ynyloxy)butanoic acid, followed by deprotection and monoesterification of alkynyl(OH)2 with 2‐bromoisobutyryl bromide. In the presence of trifunctional core molecule, alkynyl(OH)Br, and CuBr/PMDETA/Sn(Oct)2 catalytic mixtures, target ABC miktoarm star terpolymers, PS(‐b‐PCL)‐b‐PDMA and PEO(‐b‐PCL)‐b‐PDMA, were successfully synthesized in a one‐pot manner by simultaneously conducting the ATRP of 2‐(dimethylamino)ethyl methacrylate (DMA), ROP of ε‐caprolactone (ε‐CL), and the click reaction with azido‐terminated PS (PS‐N3) or azido‐terminated PEO (PEO‐N3). Considering the excellent tolerability of ATRP to a variety of monomers and the fast expansion of click chemistry in the design and synthesis of polymeric and biorelated materials, it is quite anticipated that the one‐pot concept can be applied to the preparation of well‐defined polymeric materials with more complex chain architectures. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3066–3077, 2009
Antitumor and immunomodulating effects of polysaccharides isolated from Solanum nigrum Linne
Authors: Li Jian , Li Qing‐Wang , Gao Da‐Wei , Han Zeng‐Sheng , Lu Wen‐Zong
Published: May 2009

We have examined the effects of the crude polysaccharides isolated from Solanum nigrum Linne (SNL‐P) in vitro and in vivo against U14 cervical cancer. SNL‐P showed no antiproliferative effects in vitro at a dose up to 1 mg/ml. In vivo administration with SNL‐P (90, 180, 360 mg/kg b.w., p.o.) decreased the number of ascites tumor cells and prolonged the survival time of U14 cervical‐cancer‐bearing mice. FACScan flow cytometer analysis showed that most of the ascites tumor cells were arrested in G2/M phase of cell cycle and the ratio of CD4+/CD8+ peripheral blood T‐lymphocyte subpopulations were restored following treatment of SNL‐P. Furthermore, the treatment with SNL‐P also caused a significant increment in IFN‐γ (p < 0.01, 90, 180 and 360 mg/kg b.w.) and a remarkable decrease in Il‐4 (p < 0.01, 90, 180 mg/kg b.w.; p < 0.05, 360 mg/kg b.w.) by the method of ELISA. These data showed that SNL‐P possess potent antitumor activity and SNL‐P might exert antitumor activity via activation of different immune responses in the host rather than by directly attacking cancer cells on the U14 cervical cancer bearing mice. Thus, SNL‐P could be used as an immunomodulator and an anticancer agent. Copyright © 2009 John Wiley & Sons, Ltd.
A novel 3D classification system for canine impactions—the KPG index
Authors: Kau Chung How , Pan Philip , Gallerano Ron L. , English Jeryl D.
Published: May 2009

Background

3D cone beam imaging allows localization of impacted canines, using spatial relationships, with excellent tissue contrast. The aim of this project was to assess the degree of difficulty for the treatment of impacted canines, based on the 3D information provided by cone beam imaging.

Methods

3D cone beam images taken from subjects with impacted canines were obtained from a private practice and school setting.

Results

A novel measuring scale was devised, based on three different viewpoints, in order to grade the difficulty of impaction and the potential efficacy of treatment. Depending on its anatomical location, the cusp tip and the root tip are each given a number 0–5 in three dimensions taken from a pretreatment image. The sum of the cusp tip and root tip scores in the three views dictated our anticipated difficulty of treatment.

Conclusions

A novel method of analysing impactions using cone beam imaging was proposed. This method utilizes the entire three views of a CBCT image. Copyright © 2009 John Wiley & Sons, Ltd.
How do networks and learning drive M&As? An institutional comparison between China and the United States
Authors: Lin Zhiang (John) , Peng Mike W. , Yang Haibin , Sun Sunny Li
Published: May 2009

What drives mergers and acquisitions (M&As) in different institutional environments? This article builds on the resource dependence perspective and argues that networks, learning, and institutions represent three building blocks that can enhance our understanding of the drivers behind M&As. Specifically, we consider firms as learning actors embedded in network relations and influenced by institutional development, and compare and contrast firms' acquisition activities across the United States and China. Our findings show that there are indeed important learning and network factors that lead to M&As. More interestingly, the impact of such learning and network factors varies sharply across countries with different market‐based institutions. Copyright © 2009 John Wiley & Sons, Ltd.
Senescent Growth Arrest in Mesenchymal Stem Cells Is Bypassed by Wip1-Mediated Downregulation of Intrinsic Stress Signaling Pathways
Authors: Lee Ji-Seon , Lee Mi-Ok , Moon Bo-Hyun , Shim Sung Han , Fornace Albert J. , Cha Hyuk-Jin
Published: May 2009

Human mesenchymal stem cells (hMSCs) have been widely studied as a source of primary adult stem cells for cell therapy because of their multidifferentiation potential; however, the growth arrest (also known as “premature senescence”) often found in hMSCs cultured in vitro has been a major obstacle to the in-depth characterization of these cells. In addition, the inability to maintain constant cell growth hampers the development of additional genetic modifications aimed at achieving desired levels of differentiation to specific tissues; however, the molecular mechanisms that govern this phenomenon remain unclear, with the exception of a few studies demonstrating that induction of p16INK4a is responsible for this senescence-like event. Here, we observed that the premature growth arrest in hMSCs occurs in parallel with the induction of p16INK4a, following abrogation of inhibitory phosphorylation of retinoblastoma protein. These stress responses were concurrent with increased formation of reactive oxygen species (ROSs) from mitochondria and increased p38 mitogen-activated protein kinase (MAPK) activity. The introduction of Wip1 (wild-type p53 inducible phosphatase-1), a well-studied stress modulator, significantly lowered p16INK4a expression and led to p38 MAPK inactivation, although it failed to affect the levels of ROSs. Moreover, the suppression of stress responses by Wip1 apparently extended the life span of hMSCs, compared with control conditions, while maintaining their multilineage differentiation potential. Based on these results, we suggest that senescent growth arrest in hMSCs may result from activation of stress signaling pathways and consequent onset of stress responses, due in part to ROS production during prolonged in vitro culture.

Disclosure of potential conflicts of interest is found at the end of this article.
Interplay between MEK and PI3 kinase signaling regulates the subcellular localization of protein kinases ERK1/2 and Akt upon oxidative stress
Authors: Kodiha Mohamed , Bański Piotr , Stochaj Ursula
Published: May 2009

ERK and Akt kinases are key components that participate in numerous regulatory processes, including the response to stress. Using novel tools for quantitative immunofluorescence, we show that oxidant exposure controls the intracellular activation and localization of ERK1/2 and Akt. Oxidative stress alters the nuclear/cytoplasmic levels of the kinases, drastically changing phospho‐ERK1/2 and phospho‐Akt(Ser473) levels in the nucleus. Moreover, pharmacological inhibition of PI3 kinase modulates the intracellular distribution of phospho‐ERK1/2, whereas MEK inhibition affects phospho‐Akt(Thr308) and phospho‐Akt(Ser473). Our studies identify a new signaling link in the nucleus of stressed cells, where changes in phospho‐ERK1/2 levels correlate directly with changes in phospho‐Akt(Ser473).
Moral Distress in Rehabilitation Professionals: Results From a Hospital Ethics Survey
Authors: Mukherjee Debjani , Brashler Rebecca , Savage Teresa A. , Kirschner Kristi L.
Published: May 2009

Objective

Moral distress in the rehabilitation setting was examined in a follow‐up survey. The survey had 3 goals: (1) to systematically and anonymously gather data about the ethical issues that employees struggle with in their daily work; (2) to raise the visibility of the hospital‐based ethics program and resources available to employees; and (3) to prioritize and focus the direction of the program's educational seminars, quality improvement projects, and ethics consultation.

Design

Online survey of employees.

Setting

Urban rehabilitation system of care.

Participants

The survey was open to all employees; 207 completed the survey.

Interventions

N/A

Main Outcome Measurements

N/A

Conclusions

Three broad categories of moral distress were identified: institutional ethics, professional practice, and clinical decision‐making. Institutional ethics issues related to the health care environment, such as health care reimbursement pressures and corporate culture. Professional practice issues involved codes of behavior and concepts of professionalism, including patient confidentiality/privacy. Clinical decision‐making included such practical dilemmas as conflicts around goal‐setting, discharge planning, and assessment of decision‐making capacity. An anonymous survey of staff members allowed the hospital ethics program to identify sources of moral distress and prioritize strategies to address them.
LUXURY CONSUMPTION, CULTURAL POLITICS, AND THE CAREER OF THE EARL OF ARLINGTON, 1660–1685
Authors: JACOBSEN HELEN
Published: May 2009

Henry Bennet, earl of Arlington, is a neglected statesman. A sometime diplomat, he was Charles II's longest-serving secretary of state, held the highest household office for ten years, and married his daughter to a royal bastard. It is, however, his artistic patronage that has most conspicuously been overlooked and, consequently, its political significance underestimated. Informed by his experiences abroad, he appreciated the power of the arts to influence and impress and used the cultural mediation of the English diplomatic network in his control to help skilfully fashion his domestic political identity. Through judicious display of architecture, paintings, sculpture, and furniture, Arlington created a cultural world that confirmed both his close relationship with Charles II and his dominance of foreign affairs. Even after he resigned as secretary of state in 1674, Arlington continued to deploy artistic patronage for political ends: as lord chamberlain, he controlled the largest government department and was formally responsible for fashioning the royal image. This article reconsiders Arlington's contributions as a statesman through his considered use of material consumption and artistic patronage and thereby illuminates corners of cultural practice which are situated firmly in the political sphere.
STRATEGIC BOMBING AND RESTRAINT IN ‘TOTAL WAR’, 1915–1918
Authors: BARROS ANDREW
Published: May 2009

Recent studies of ‘total war’ depict a process of inexorable expansion leading to an often nebulous linkage of everything to war. This article takes the study of ‘total war’ in the opposite direction by studying a specific example of strategic restraint. It examines how the French bombing strategy that was developed over the course of the First World War went to considerable lengths to maintain a distinction between the civilian and the military. The article studies France's restraint by highlighting the strategic, geographical, institutional, and economic factors upon which it was built. It then goes on to examine the political pressures for an expansion of bombing which proved incapable of overturning this policy. Finally, it contrasts French restraint with that of its key ally, Great Britain. There, bombing developed into a strategic weapon designed to destroy the ‘home front’. This study of restraint underscores the importance of limits, and the attendant choices government has to make, in understanding the course and intensity of a country's mobilization for modern war.
MUSICAL MODERNITY AND CONTESTED COMMEMORATION AT THE FESTIVAL OF REMEMBRANCE, 1923–1927
Authors: MANSELL JAMES G.
Published: May 2009

This article makes the case for incorporating music into the history of war commemoration in 1920s Britain by examining John Foulds'sA World Requiem, performed at the British Legion's first Festivals of Remembrance at the Royal Albert Hall between 1923 and 1926. A simultaneously modernist and spiritual work, Foulds'sRequiemchallenges Jay Winter's conclusion that modernism was unconcerned with public grief. The controversy which theRequiemcaused also reveals the contested nature of public memory, particularly where music and religion were concerned. TheRequiem's axing in 1927 points to a hegemonic process which, although it had yet fully to take shape, found no room on Armistice Night for Foulds's progressive ideals.
THE RECENT HISTORIOGRAPHY OF AMERICAN NEOCONSERVATISM
Authors: HIGH BRANDON
Published: May 2009

This article surveys the literature on American neoconservatism since 1979, emphasizing those monographs which include assessments of developments in neoconservatism since 1995. It analyses the origins of neoconservatism in the anti-Stalinist Left and in the ideological divisions of the Democratic party. It assesses the position of neoconservatism in the American conservative tradition and its influence on Republican party policy. It places neoconservatism within the broader context of American foreign and domestic policy. It examines the emergence of networks of support which have sustained neoconservatives as a group of policy intellectuals independent of universities. It concludes by asking whether neoconservatism can be productively viewed as an expression of American ethnic politics, in particular as a response to the varying guises which anti-Semitism has assumed in the United States. The article asserts that, although commentators on neoconservatism from varying ideological standpoints have avoided the question of the neoconservatives' ethnicity, it offers a plausible explanation for the protean nature and apparent inconsistency of neoconservatism over the last forty years.
The Use of the Graphic Method in Tracing the Distribution of Milk-carried Scarlet Fever Illustrated by an Outbreak in Clifton, in 1900
Authors: Davies D. S.
Published: May 2009

The Graphic Method, which I first used in connection with the outbreak of milk-carried enteric fever which occurred in Clifton in 1897, is here applied to a similar outbreak of milk-carried scarlet fever.
Studies in Relation to Malaria II. (Cont.) The Structure and Biology of Anopheles (Anopheles maculipennis)
Authors: Nuttall George H. F. , Shipley Arthur E.
Published: May 2009

Before proceeding to describe the imago of Anopheles, we wish to record some observations regarding the hibernation of the larvae of various Culicidae. Grassi (1900, p. 47)1 considered that A. bifurcatus hibernated chiefly in the larval form, for he found the larvae of this species in midwinter in Southern and Central Italy, the imagines being rarely encountered. It was quite different with A. maculipennis. In this case the imagines congregated in houses, huts, caverns, etc., whereas no larvae could be found during the winter. Though he assumed that it was so, his finding the larvae in midwinter in the first instance did not prove that they hibernated, for they might well have been derived from late-laid eggs.
Observations on the Recurrence of Diphtheria in Cambridge in the Spring of 1901
Authors: Cobbett Louis
Published: May 2009

The outbreak of Diphtheria which occurred in Cambridge and Chesterton last October and November has already been the subject of a paper in this Journal, which dealt with the facts observed up to January 5th, 1901. The present communication deals with a return of the disease in the Spring of this year.
Characterization and Grouping of Phage Types of Salmonella Paratyphi B, Especially of a New Type ‘Sittard’, by Sensitivity to Type Phages and by Lysogenic Properties
Authors: Scholtens R. Th.
Published: May 2009

Summary and Discussion

1. If lysogenicity is used in conjunction with sensitivity to a set of phages aa a tool for phage-typing, a further subdivision of the phage types of Salm. paratyphi B becomes possible, and also the types fall into a number of natural groups. When lysogenicity is tested by growth of two types in mixed culture, phages are produced which by their characteristic host ranges reveal a subdivision of types, parallel and complementary to the subdivision found by a study of lysogenicity. These phage reactions therefore possess a biological significance not entirely empirical.

2. The method of Craigie & Yen, which made possible a great advance in phage typing of Salm. typhi by means of preparations derived by adaptation from a single phage, has not yet been shown to be applicable to the typing of Salm. paratyphi B (Felix & Callow, 1951). As some of the typing phages used in the Felix & Callow system are identical with certain ‘natural’ phages derived from lysogenic strains, the lysogenic character of the types they reveal may be used in conjunction with these sensitivity tests as characteristics of phage types, if the set of phages is increased by addition of a few, shown in Table 1. This suggestion was made to the International Committee for Enteric Phage Typing in 1952.

3. In addition to the demonstration by the direct method of phages carried by lysogenic strains of Salm. paratyphi B, phages derived from mixed cultures of different types are characteristic of some phage types. Further development of the use of such phages and study of their nature and origin demand further research. Until further investigations have been made, the subdivision of phage types which they reveal must be regarded as tentative.

4. Strains from a large outbreak of paratyphoid fever, which could not be typed reliably by the method of Felix & Callow, possessed peculiar lysogenic properties which, together with certain phage reactions, justify their designation as a new type, ‘Sittard’. These strains can be identified if phages derived from tests of lysogenic power are used in addition to those of the Felix & Callow system. A number of strains from other sources, diagnosed as type ‘Sittard’ by their sensitivity to phages, were shown to possess lysogenic properties characteristic of the type.

5. A few other strains, shown in a similar way to represent new types, are described.