bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymer‐based Spherical Activated Carbons – From Adsorptive Properties to Filter Performance
Authors: Böhringer Bertram , Guerra Gonzalez Omar , Eckle Ilsebill , Müller Marco , Giebelhausen Jann‐Michael , Schrage Christian , Fichtner Sven 
Published: January 2011

AbstractPolymer‐based spherical activated carbon (PBSAC), produced by means of carbonization and subsequent activation of a polymeric precursor in a batch process represent adsorbents with adjustable pore size distribution and adsorption characteristics. This flexibility results from batch operation and from the possibility to combine different activation media, therefore controlling the mechanisms of pore generation. The geometry and the mechanical properties of PBSAC allow for structuring of filter media e.g., for adsorbent enlargement or fixation. Other intrinsic product properties such as roundness, high crush strength and high abrasion resistance of PBSAC offer advantages in various adsorption applications.
Wnt/β‐catenin signaling is disrupted in theextra‐toes(Gli3Xt/Xt) mutant from early stages of forebrain development, concomitant with anterior neural plate patterning defects
Authors: Fotaki Vassiliki , Price David J. , Mason John O. 
Published: January 2011

AbstractThe zinc finger transcription factor Gli3 is essential for normal development of the forebrain. Mutant mice with no functional Gli3 (extra‐toes,Gli3Xt/Xtmutants) display a massive reduction in the size of the telencephalic lobes and absence of dorsomedial telencephalic structures, including the cortical hem, which normally expresses a number of Wnt molecules essential for patterning the hippocampus. Dorsomedial telencephalic Wnt activity, transduced through the Wnt/β‐catenin signaling pathway, is also required for hippocampal specification and dorsoventral telencephalic patterning. Wnts whose normal expression is restricted to the cortical hem are completely absent inGli3Xt/Xtembryos, but some expression of those Wnts with a broader expression domain persists, raising the possibility that Wnt/β‐catenin signaling may still be active in this mutant. We examined whether theWntexpression that persists in theGli3Xt/Xtmutant neocortex activates Wnt/β‐catenin signaling, using the BAT‐gal transgenic reporter. We found Wnt/β‐catenin signaling consistently decreased in the forebrains ofGli3Xt/Xtmutants, even prior to the formation of the cortical hem. This is accompanied by a severe reduction in expression ofWnt7bandWnt8bat the lateral edges of the anterior neural plate that will give rise to the pallium. In addition, we found a significant increase in the expression of rostroventral markers of the anterior neural plate that will give rise to the basal forebrain. Our data reveal that Gli3 is required at the neural plate stage to regulateWntexpression and Wnt/β‐catenin signaling in the presumptive forebrain and confirm its previously proposed role in patterning the anterior neural plate. J. Comp. Neurol. 519:1640–1657, 2011. © 2011 Wiley‐Liss, Inc
Stereotyped axonal arbors of retinal ganglion cell subsets in the mouse superior colliculus
Authors: Hong Y. Kate , Kim In‐Jung , Sanes Joshua R. 
Published: January 2011

AbstractMouse retinal ganglion cells (RGCs) have been classified into around 20 subtypes based on the shape, size, and laminar position of their dendritic arbors. In most cases tested, RGC subtypes classified in this manner also have distinct functional signatures. Here we asked whether RGC subtypes defined by dendritic morphology have stereotyped axonal arbors in their main central target, the superior colliculus (SC). We used transgenic and viral methods to sparsely label RGCs and characterized both dendritic and axonal arbors of individual RGCs. Axon arbors varied in size, shape, and laminar position. For each of 12 subtypes defined dendritically, however, axonal arbors in the contralateral SC showed considerable stereotypy. We found no systematic relationship between the laminar position of an RGC's dendrites within the inner plexiform layer and that of its axon within the retinorecipient zone of the SC, suggesting that distinct developmental mechanisms specify dendritic and axonal laminar positions. We did, however, note a significant correlation between the dendritic field sizes of RGCs and the laminar position of their axon arbors: RGCs with larger dendritic areas, and hence larger receptive fields, projected to deeper strata within the SC. Finally, combining these new results with previous physiological analyses, we find that RGC subtypes that share similar functional properties, such as directional selectivity, project to similar depths within the SC. J. Comp. Neurol. 519:1691–1711, 2011. © 2011 Wiley‐Liss, Inc.
Expression pattern of cadherins in the naked mole rat (Heterocephalus glaber) suggests innate cortical diversification of the cerebrum
Authors: Matsunaga Eiji , Nambu Sanae , Iriki Atsushi , Okanoya Kazuo 
Published: January 2011

AbstractThe cerebral cortex is an indispensable region for higher cognitive function that is remarkably diverse among mammalian species. Although previous research has shown that the cortical area map in the mammalian cerebral cortex is formed by innate and activity‐dependent mechanisms, it remains unknown how these mechanisms contribute to the evolution and diversification of the functional cortical areas in various species. The naked mole rat (Heterocephalus glaber) is a subterranean, eusocial rodent. Physiological and anatomical studies have revealed that the visual system is regressed and the somatosensory system is enlarged. To examine whether species differences in cortical area development are caused by intrinsic factors or environmental factors, we performed comparative gene expression analysis of neonatal naked mole rat and mouse brains. The expression domain of cadherin‐6, a somatosensory marker, was expanded caudally and shifted dorsally in the cortex, whereas the expression domain of cadherin‐8, a visual marker, was reduced caudally in the neonatal naked mole rat cortex. The expression domain of cadherin‐8 was also reduced in other visual areas, such as the lateral geniculate nucleus and superior colliculus. Immunohistochemical analysis of thalamocortical fibers further suggested that somatosensory input did not affect cortical gene expression in the neonatal naked mole rat brain. These results suggest that the development of the somatosensory system and the regression of the visual system in the naked mole rat cortex are due to intrinsic genetic mechanisms as well as sensory input‐dependent mechanisms. Intrinsic genetic mechanisms thus appear to contribute to species diversity in cortical area formation. J. Comp. Neurol. 519:1736‐1747, 2011. © 2011 Wiley‐Liss, Inc.
Expression of Hairy/enhancer of split genes in neural progenitors and neurogenesis domains of the adult zebrafish brain
Authors: Chapouton Prisca , Webb Katharine J. , Stigloher Christian , Alunni Alessandro , Adolf Birgit , Hesl Birgit , Topp Stefanie , Kremmer Elisabeth , Bally‐Cuif Laure 
Published: January 2011

AbstractAll subdivisions of the adult zebrafish brain maintain niches of constitutive neurogenesis, sustained by quiescent and multipotent progenitor populations. In the telencephalon, the latter potential neural stem cells take the shape of radial glia aligned along the ventricle and are controlled by Notch signalling. With the aim of identifying new markers of this cell type and of comparing the effectors of embryonic and adult neurogenesis, we focused on the family of hairy/enhancer of split [E(spl)] genes. We report the expression of seven hairy/E(spl) (her) genes and the new helt gene in three neurogenic areas of the adult zebrafish brain (telencephalon, hypothalamus, and midbrain) in relation to radial glia, proliferation, and neurogenesis. We show that the expression of most her genes in the adult brain characterizes quiescent radial glia, whereas only few are expressed in progenitor domains engaged in active proliferation or neurogenesis. The low proliferation status of most her‐positive progenitors contrasts with the embryonic nervous system, in which her genes are expressed in actively dividing progenitors. Likewise, we demonstrate largely overlapping expression domains of a set of her genes in the adult brain, which is in striking contrast to their distinct embryonic expression profiles. Overall, our data provide a consolidated map of her expression, quiescent glia, proliferation, and neurogenesis in these various subdivisions of the adult brain and suggest distinct regulation and function of Her factors in the embryonic and adult contexts. J. Comp. Neurol. 519:1748–1769, 2011. © 2011 Wiley‐Liss, Inc.
Interpretation of cellular proliferation data: Avoid the panglossian
Authors: Roederer Mario 
Published: January 2011

AbstractThere are several statistics that may be calculated to characterize a cellular proliferation experiment. By far, the most commonly‐reported statistic is the percent of cells in the final culture that have divided; however, this statistic has significant limitations. Other statistics provided by software modeling provide a much richer characterization of the biological response; however, their use also comes with caveats. Here, I discuss the practical application of these statistics, including their limitations and interdependencies, using hypothetical data. The goal of this perspective is to prevent the blind reliance or overly optimistic (“panglossian”) interpretation of the statistics generated by software, so that researchers and reviewers have a more‐informed basis for drawing conclusions from the data. Published 2011 Wiley‐Liss, Inc.
A smart exponential‐threshold‐linear backoff mechanism for IEEE 802.11 WLANs
Authors: Ke Chih‐Heng , Wei Chih‐Cheng , Lin Kawuu W. , Ding Jen‐Wen 
Published: January 2011

AbstractBased on the standardized IEEE 802.11 Distributed Coordination Function (DCF) protocol, this paper proposes a new backoff mechanism, called Smart Exponential‐Threshold‐Linear (SETL) Backoff Mechanism, to enhance the system performance of contention‐based wireless networks. In the IEEE 802.11 DCF scheme, the smaller contention window (CW) will increase the collision probability, but the larger CW will delay the transmission. Hence, in the proposed SETL scheme, a threshold is set to determine the behavior of CW after each transmission. When the CW is smaller than the threshold, the CW of a competing station is exponentially adjusted to lower collision probability. Conversely, if the CW is larger than the threshold, the CW size is tuned linearly to prevent large transmission delay. Through extensive simulations, the results show that the proposed SETL scheme provides a better system throughput and lower collision rate in both light and heavy network loads than the related backoff algorithm schemes, including Binary Exponential Backoff (BEB), Exponential Increase Exponential Decrease (EIED) and Linear Increase Linear Decrease (LILD). Copyright © 2011 John Wiley & Sons, Ltd.
Traffic‐aware downlink power allocation in multiuser OFDM system
Authors: Rong Bo , Hu Rose Qingyang , Li Wei , Qian Yi 
Published: January 2011

AbstractMultiuser orthogonal frequency division multiplexing (OFDM) is a promising technology to achieve high uplink/downlink (DL) capacities in the next generation broadband wireless networks such as WiMAX (Worldwide Interoperability for Microwave Access). In this paper, we investigate the DL adaptive power allocation (APA) in multiuser OFDM system from the perspective of cross‐layer design. Specifically, we formulate APA as an optimization problem with the traffic profile of each user asit a priori knowledge. To solve the optimization problem, we develop a fairness‐constrained optimal prioritized effective throughput (PET) strategy and the corresponding iterative algorithms, aiming at balancing the prioritized effective throughput and the linear or logarithmic user satisfaction‐based fairness. Simulation results show that our proposed APA optimization approach can achieve satisfying performance. Copyright © 2011 John Wiley & Sons, Ltd.
Generic substitution for immunosuppressive drugs
Authors: Helderman J. Harold 
Published: January 2011

AbstractThe advent of generic alternatives for transplant immunosuppressant drugs has engendered concern and discussion. The process by which the food and drug administration (FDA) approves generic substitutes is reviewed. A category of medicines deﬁned as narrow therapeutic index (NTI) drugs is deﬁned with evidence that many (but not all) of the commonly used transplant medications fall into this category. It is demonstrated that the current FDA standards are inadequate to vet NTI agents. Outcomes data are presented that show generic switching for NTI drugs can be successfully accomplished with careful blood level monitoring, but clinical and ﬁnancial negative consequences can ﬂow from unregulated switching. Recommendations are made for provider use of generic immunsuppressants, for recipient education and response to switching, and for pharmacy shandling of generic alternatives.
Immune complex enhances tolerogenecity of immature dendritic cells via FcγRIIb and promotes FcγRIIb‐overexpressing dendritic cells to attenuate lupus
Authors: Zhang Yan , Liu Shuxun , Yu Yizhi , Zhang Ting , Liu Juan , Shen Qian , Cao Xuetao 
Published: January 2011

AbstractA balance of inhibitory and activating signals determines the function of dendritic cells (DCs) in the immune response, which may be regulatory or stimulatory. Defects of inhibitory receptor FcγRIIb are involved in the pathogenesis of autoimmune diseases such as systemic lupus erythematosus (SLE), in which high levels of circulating immune complexes (IC) exist. Our previous study showed that IC/Ig can suppress TLR4‐triggered inflammatory responses in macrophages via FcγRIIb. This led us to question whether IC/Ig can polarize FcγRIIb‐overexpressing DCs (DC‐FcγRIIb) to be tolerogenic, thus attenuating lupus progression once infused in vivo. First, we found that IC/Ig markedly inhibited LPS‐ or CpG‐induced DC maturation, enhanced tolerogenicity of DCs via FcγRIIb, and induced massive prostaglandin E2 (PGE2) secretion from DCs, both contributing to T‐cell hyporesponsiveness. Endogenous Ig and lupus‐derived IC also exhibited the same effect. DC‐FcγRIIb, transfected with recombinant adenovirus encoding FcγRIIb, displayed enhanced tolerogenic function and produced more PGE2 in the presence of IC, thus further inhibiting T‐cell responses. Importantly, in vivo infusion with DC‐FcγRIIb significantly reduced kidney damage and prolonged the survival of lupus‐prone MRL/lpr mice either before or after the onset of clinic lupus. Therefore, administration of DC‐FcγRIIb may be a new approach to attenuate lupus progression.
Mechanistic Insights into the Palladium‐Catalysed Asymmetric Phosphination of Cyclohexenyl Triflate
Authors: Julienne Delphine , Delacroix Olivier , Lohier Jean‐François , de Oliveira‐Santos Jana Sopkova , Gaumont Annie‐Claude 
Published: January 2011

AbstractPreliminary results on the mechanism of the asymmetricphosphination involving an achiral alkenyl triflate (cyclohexenyl triflate) and a secondary phosphane–borane, (methyl)phenylphosphane–borane (1) are reported. A catalytic cycle is proposed based on the variable‐temperature 31P NMR characterization of the individual steps (oxidative addition, transmetallation and reductive elimination). Each likely intermediate involved in this asymmetric C–P coupling reaction has been identified and characterized. Hence, cationic oxidative addition complex 3 has been readily synthesized and engaged in the stoichiometric reaction with highly enantio‐enriched secondary phosphane–borane (SP)‐1 enabling to isolate the corresponding diastereomerically pure transmetallation adduct (S,S,RP)‐5. Its structure has been confirmed by X‐ray crystallography. Its decomposition by reductive elimination affords the highly enantio‐enriched coupling product (SP)‐2. This study also provides information on the origin of the enantioselectivity.
The η2 Complex of Nickel Bis(diphenylphosphanyl)propane with Fullerene: {Ni(dppp)(η2‐C60)}·(Solvent) Obtained by Reduction
Authors: Konarev Dmitri V. , Khasanov Salavat S. , Yudanova Evgeniya I. , Lyubovskaya Rimma N. 
Published: January 2011

AbstractThe η2 complex of nickel bis(diphenylphosphanyl)propane with fullerene, {Ni(dppp)(η2‐C60)}·(C6H14)0.84·(C6H4Cl2)0.16 (1) (C6H14: hexane, C6H4Cl2: o‐dichlorobenzene), has been obtained by reduction of the Ni(dppp)Cl2 and C60 mixture with sodium fluorenone in o‐dichlorobenzene and slow precipitation of the single crystals by diffusion of hexane. Nickel coordinates to the 6–6 bond of C60 by η2‐coordination to form Ni–C(C60) bonds with a length of 1.948–1.951(2) Å, which are the shortest M–C bonds among known η2 complexes of fullerenes. The 6–6 bond length [1.488(3) Å] where the Ni atom is coordinated is noticeably longer than the average length of other 6–6 bonds in C60 [1.388(2) Å]. Coordination of nickel to C60 results in the splitting of two bands for two IR‐active modes of C60 into three bands, because of the lower symmetry of C60, and a noticeable shift in the F1u(4) mode of C60 to lower frequencies, as a result of π back‐donation. The dark green complex manifests two absorption bands at 664 and 890 nm in the visible range. The complex is EPR silent since only a weak narrow signal with g = 2.0000 and ΔH = 0.17 mT was found in the EPR spectrum of 1 at room temperature, which originates from about 0.1 % of spins of the total amount of C60.
Unraveling the Electronic Properties of the Photoinduced States of the H‐Cluster in the [FeFe] Hydrogenase from D. desulfuricans
Authors: Silakov Alexey , Reijerse Edward J. , Lubitz Wolfgang 
Published: January 2011

Abstract[FeFe] hydrogenases belong to a class of enzymes that catalyze the reversible heterolytic splitting of molecular hydrogen. The structure of their active site is rather unusual consisting of a CN– and CO‐coordinated [2Fe] subcluster connected to a ferredoxin‐like [4Fe4S] subcluster through one of the Cys‐S ligands. The iron, distal to the “cubane” has an open coordination site that is believed to be the substrate binding site. In the active forms of the H‐cluster, this site can be inhibited by carbon monoxide, which results in an EPR‐active state, called Hox‐CO. At temperatures below 100 K, illumination in the visible range causes conversion of this state into two other EPR‐active states. One of these is the Hox state, i.e. the catalytically active form, characterized by a vacant external coordination site. The other state (HLI) is probably characterized by dissociation of the bridging CO ligand. The photodissociation of the Hox‐CO state provides a convenient way to study changes in the electronic structure caused by dissociation of various CO ligands. In this article, we show results of an advanced EPR study of the light‐induced species of the active site, in particular, HLI. On the basis of the resolved hyperfine signals of the 1H, 14N, 13C, and 57Fe nuclei, we obtained a detailed picture of the electronic structure of the H‐cluster. It turned out that dissociation of the bridging CO ligand causes a major rearrangement of the structure of the H‐cluster and large changes in the distribution of the unpaired spin. Moreover, it appears that the extent of spin delocalization in the 2Fe subcluster in the case of HLI is intermediate between that of Hox and Hox‐CO.
Relaxometric Study of a Series of Monoaqua GdIIIComplexes of Rigidified EGTA‐Like Chelators and Their Noncovalent Interaction with Human Serum Albumin
Authors: Botta Mauro , Avedano Stefano , Giovenzana Giovanni Battista , Lombardi Alberto , Longo Dario , Cassino Claudio , Tei Lorenzo , Aime Silvio 
Published: January 2011

AbstractThe lanthanide(III) complexes of five EGTA [ethyleneglycol‐bis(2‐aminoethyl) ether‐N,N,N′,N′‐tetraacetic acid] derivatives fused with aromatic (benzene:L1; naphthalene:L2) and functionalized aromatic (L3–L5) moieties on the oxyethylene bridge were investigated in aqueous solution.1H and13C NMR spectra of the LaIIIand LuIIIcomplexes ofL1andL2indicate that the structural differences across the Ln series found for the [Ln(EGTA)]–complexes is maintained in the new derivatives. The presence of the aromatic moiety favours an increased stereochemical rigidity, as assessed by VT13C NMR spectra. Temperature‐dependent17O NMR spectroscopic data and 1/T11H NMRD profiles of the GdIIIcomplexes ofL1–L3were measured and globally analyzed to obtain the parameters influencing the water exchange rate,kex, and rotational dynamics. Thekexvalues are ca. twice as high as the corresponding value of [Gd(EGTA)]–and very close to optimal. The lipophilic complexes [GdL4]–and [GdL5]–form micellar aggregates whose NMRD profiles were measured and analyzed in terms of a model that allows separation of global motion and local rotation. The noncovalent binding interaction of the complexes to human serum albumin and the relaxivity of the macromolecular conjugates were investigated with relaxometric techniques at 20 MHz and 298 K, and the importance of a restricted local motion of the complex at the binding site for attaining large relaxivity enhancement outlined. Theoretical docking simulations and relaxometric competition experiments provided insights into the binding modes of the complexes.
Carbasugar Analogues of Galactofuranosides: Pseudodisaccharide Mimics of Fragments of Mycobacterial Arabino­galactan
Authors: Frigell Jens , Pearcey Jean A. , Lowary Todd L. , Cumpstey Ian 
Published: January 2011

AbstractA partially protected carbasugar analogue of β‐galactofuranose was converted into an α‐galacto‐configured 1,2‐epoxide, which was opened by alcohols under Lewis acid catalysis with regioselective attack at C‐1 to give β‐galacto‐configured C‐1 ethers. Using OH‐5 and OH‐6 carbagalactofuranose derivatives as nucleophiles, we synthesised pseudodisaccharide analogues of substructures of the arabinogalactan from M. tuberculosis. The dicarba analogue of the disaccharide Galf(β1→5)Galf was found to moderately inhibit the action of GlfT2 galactofuranosyl transferase from M. tuberculosis.
A Highly Efficient, Large‐Scale, Asymmetric Direct Aldol Reaction Employing Simple Threonine Derivatives as Recoverable Organocatalysts in the Presence of Water
Authors: Wu Chuanlong , Fu Xiangkai , Li Shi 
Published: January 2011

AbstractA one‐step O‐acylation of threonine resulted in a simple and readily available threonine‐surfactant organocatalyst that could efficiently catalyze the direct asymmetric aldol reactions of cyclic and acyclic ketones with a series of aromatic aldehydes in the presence of water at room temperature with good yields (up to 99 %), diastereoselectivities (up to 99:1), and enantiomeric excesses (>99 %). The catalyst can beeasily recovered and reused with no decrease of enantioselectivity after six cycles. This novel catalyst can be efficiently used in large‐scale reactions, with the enantioselectivity being maintained at the same level, which offers great possibilities for application in industry.
Phospha‐Michael‐Type Reactions between 1,2‐Diaza‐1,3‐dienes and Bidentate Nucleophiles: Formation of New Mono‐ and Diylides and their Elaboration to Heterocycles
Authors: Boga Carla , Zanna Nicola , Attanasi Orazio A. , Baccolini Graziano , De Crescentini Lucia , Forlani Luciano , Mantellini Fabio , Nicolini Simona , Micheletti Gabriele , Tozzi Silvia 
Published: January 2011

AbstractPhospha‐Michael additions of a series of methylene‐bridged phosphorus bidentate nucleophiles to 1,2‐diaza‐1,3‐dienes gave monoadducts and bisadducts in high yields under mild conditions. In particular, a series of new ylides and symmetrical diylides have been obtained from bis(diphenyl)phosphanes. The use of diphenylphosphanylamino derivatives gave, through phospha‐Michael addition, ylide intermediates that underwent spontaneous intramolecular attack by the amino group belonging to the Michael donor reagent moiety, thus giving access to new heterocycles.