bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of exposure to the water-soluble fraction of crude oil on the swimming performance and the metabolic and ionic recovery postexercise in Pacific herring (Clupea pallasi)
Authors: Kennedy Christopher J. , Farrell Anthony P.
Published: September 2006

The swimming performance and recovery from exercise were determined in juvenile Pacific herring (Clupea pallasi) following exposure to the water-soluble fraction (WSF) of North Slope crude oil for more than eight weeks. Total polycyclic aromatic hydrocarbon concentrations (mean ± standard error) at the beginning of exposures were as follows: control, 0.2 ± 0.1 μg/L; low, 9.6 ± 2.5 μg/L; medium, 40.7 ± 6.9 μg/L; and high, 120.2 ± 11.4 μg/L. Biological availability of hydrocarbons was confirmed by a significant induction of hepatic cytochrome P450 content and ethoxyresorufin-O-deethylase activity. Critical swimming speed (Ucrit) was significantly reduced in fish exposed to the highest concentration of WSF for 96 h (11% ± 3.7% reduction) and at the two highest concentrations at four weeks (16% ± 3.6% and 29% ± 5.4% reductions) and eight weeks (11% ± 3.8% and 40% ± 5.7% reductions). Mortality occurred in all groups 24 h following Ucrit swim trials, with significantly higher mortalities observed in fish exposed to WSF in a concentration- and time-dependent manner (maximum mortality of 72.2% ± 5.5% in the eight-week, high-exposure group). Burst swimming alone resulted in increased plasma cortisol, lactate, Na+, and Cl− concentrations and decreased muscle glycogen levels that returned to baseline values by 24 h. An interpretation of the effect of WSF exposure on postexercise metabolic recovery was complicated by pre-exercise alterations in several parameters. The time courses and magnitudes of several key postexercise parameters, including plasma cortisol, lactate, and muscle glycogen, were significantly altered by exposure to WSF. The present study clearly shows that hydrocarbon exposure can reduce the swimming ability of fish and their ability to recover from exhaustive exercise.
Toxicity of ozonated seawater to marine organisms
Authors: Jones Adam C. , Gensemer Robert W. , Stubblefield William A. , van Genderen Eric , Dethloff Gail M. , Cooper William J.
Published: September 2006

Ballast water transport of nonindigenous species (NIS) is recognized as a significant contributor to biological invasions and a threat to coastal ecosystems. Recently, the use of ozone as an oxidant to eliminate NIS from ballast while ships are in transit has been considered. We determined the toxicity of ozone in artificial seawater (ASW) for five species of marine organisms in short-term (≤ 5 h) batch exposures. Larval topsmelt (Atherinops affinis) and juvenile sheepshead minnows (Cyprinodon variegatus) were the most sensitive to oxidant exposure, and the mysid shrimp (Americamysis bahia) was the most sensitive invertebrate. Conversely, benthic amphipods (Leptocheirus plumulosus and Rhepoxinius abronius) were the least sensitive of all species tested. Mortality from ozone exposure occurred quickly, with median lethal times ranging from 1 to 3 h for the most sensitive species, although additional mortality was observed 1 to 2 d following ozone exposure. Because ozone does not persist in seawater, toxicity likely resulted from bromide ion oxidation to bromine species (HOBr and OBr−), which persist as residual toxicants after at least 2 d of storage. Total residual oxidant (TRO; as Br2) formation resulting from ozone treatment was measured in ASW and four sitespecific natural seawaters. The rate of TRO formation correlated with salinity, but dissolved organic carbon and total dissolved nitrogen did not affect TRO concentrations. Acute toxicity tests with each water over 48 h using mysid shrimp, topsmelt, and sheepshead minnows yielded results similar to those of batch exposure. Addition of sodium thiosulfate (Na2S2O3) to ozonated waters resulted in TRO elimination and survival of all organisms. Our results provide necessary information for the optimization of an efficacious ozone ballast water treatment system.
Evaluation of Genotoxic effects of heavy metals and arsenic in wild nestling white storks (Ciconia ciconia) and black kites (Milvus migrans) from southwestern Spain after a mining accident
Authors: Baos Raquel , Jovani Roger , Pastor Nuria , Tella José L. , Jiménez Begoña , Gómez Gemma , González Marí J. , Hiraldo Fernando
Published: September 2006

Studies of birds from Doñana (southwestern Spain) after the Aznalcóllar mining accident (April 1998) have reported high levels of genetic damage when compared to conspecifics from reference areas. However, potential relationships between DNA damage and metal pollution have not yet been reported. The aim of the present study was to investigate the current levels of Zn, Pb, As, Cu, and Cd and to determine if they were associated with the genetic damage observed in free-living, nestling white storks (Ciconia ciconia) and black kites (Milvus migrans) born in the Doñana area after the mining spill. Blood concentrations of heavy metals and of As were quantified and DNA damage (comet assay) was determined in 258 storks and 132 kites monitored during a four-year period (1999–2002). Correlations between these elements and genetic damage varied between species and throughout years within species. Some elements did not show any relationship with DNA damage (e.g., Pb), whereas others had a significant correlation (e.g., As in storks, and Cu and Cd in kites) or only marginal statistical effects (e.g., Zn and Cd in storks, and As in kites) in some years but not in others. These results suggest that nestling white storks and black kites were affected, in part, by the elements studied, but they alone do not satisfactorily explain the observed DNA damage. Moreover, our results show that species-specific differences should be carefully considered when planning schemes for pollution monitoring, and highlight the need for including the temporal scale into the study of the pollutants effects in the wild.
Endoplasmic reticulum stress and apoptosis
Authors: Faitova Jitka , Krekac Daniel , Hrstka Roman , Vojtesek Borivoj
Published: September 2006

Cell death is an essential event in normal life and development, as well as in the pathophysiological processes that lead to disease. It has become clear that each of the main cellular organelles can participate in cell death signalling pathways, and recent advances have highlighted the importance of the endoplasmic reticulum (ER) in cell death processes. In cells, the ER functions as the organelle where proteins mature, and as such, is very responsive to extracellular-intracellular changes of environment. This short overview focuses on the known pathways of programmed cell death triggering from or involving the ER.
A Hybrid Supercapacitor Fabricated with a Carbon Nanotube Cathode and a TiO2–B Nanowire Anode
Authors: Wang Q. , Wen Z. H. , Li J. H.
Published: September 2006

Recently, a new hybrid supercapacitor, integrating both the advantages of supercapacitors and lithium‐ion batteries, was proposed and rapidly turned into state‐of‐the‐art energy‐storage devices with a high energy density, fast power capability, and a long cycle life. In this paper, a new hybrid supercapacitor is fabricated by making use of the benefits of 1D nanomaterials consisting of a carbon nanotube (CNT) cathode and a TiO2–B nanowire (TNW) anode, and the preliminary results for such an energy‐storage device operating over a wide voltage range (0–2.8 V) are presented. The CNT–TNW supercapacitor is compared to a CNT–CNT supercapacitor, and discussed with regards to available energy densities, power capabilities, voltage profiles, and cycle life. On the basis of the total weight of both active materials, the CNT–TNW supercapacitor delivers an energy density of 12.5 W h kg–1 at a rate of 10 C, double the value of the CNT–CNT supercapacitor, while maintaining desirable cycling stability. The combination of a CNT cathode and a TNW anode in a non‐aqueous electrolyte is proven to be suitable for high‐performance hybrid supercapacitor applications; this can reasonably be assigned to the interesting synergistic effects of the two nanomaterials. It is hoped that the results presented in this study might renew interest in the design of nanomaterials that are applicable not only to hybrid supercapacitors, but also to energy conversion and storage applications of the future.
A Supramolecular Chiroptical Switch Using an Amorphous Azobenzene Polymer
Authors: Kim M. J. , Yoo S. J. , Kim D. Y.
Published: September 2006

Supramolecular chirality has been optically induced in an achiral epoxy‐based polymer containing photoresponsive azobenzene groups. The origin of this effect is the long‐range helical arrangement of the azobenzenes, which extends through the entire thickness of the film. The helicity induced by the handedness of the laser can be reversibly switched by alternately exposing the film to a 488 nm laser with right‐ and left‐handed elliptical polarization. The chiral properties of these films have been characterized by circular dichroism spectroscopy and optical rotation. After five switching cycles, the fatigue resistance is seen to depend on the absorption wavelength of the film, probably due to differences in the photoresponsive speed of the azobenzenes and the polymeric segments.
Preparation of Near‐IR Fluorescent Nanoparticles for Fluorescence‐Anisotropy‐Based Immunoagglutination Assay in Whole Blood
Authors: Deng T. , Li J.‐S. , Jiang J.‐H. , Shen G.‐L. , Yu R.‐Q.
Published: September 2006

A class of novel core/shell near‐IR fluorescent nanoparticles have been prepared through co‐hydrolysis of a hydrophobic silicon alkoxide, hexadecyltrimethoxysilane, and tetraethyl orthosilicate as the dye‐doped core, followed by the formation of a hydrophilic shell via hydrolysis of tetraethyl orthosilicate in a water‐in‐oil microemulsion. The co‐hydrolysis of hexadecyltrimethoxysilane and tetraethyl orthosilicate produces a highly hydrophobic core for the entrapment of a low‐cost near‐IR fluorescence dye, methylene blue. Experimental investigation of this particular core/shell nanoparticle in comparison with conventional dye‐doped silica nanoparticles demonstrates that the hydrophobic core enables the doped dye to exhibit enhanced fluorescence and show improved stability to dye leaching and exogenous quenchers. In contrast to rhodamine B doped silica nanoparticles, the near‐IR fluorescent nanoparticles also show negligible background fluorescence and low inner‐filtration interference in complex biological systems such as whole blood. This advantage is utilized for the development of an immunoagglutination assay method based on fluorescence‐anisotropy measurement for the detection of alpha fetoprotein (AFP) in whole‐blood samples. The results reveal that increase in fluorescence anisotropy is linearly correlated with AFP concentration in the range 1.9–51.9 ng mL–1.
The impact of climate change on global river flow in HadGEM1 simulations
Authors: Falloon Pete D. , Betts Richard A.
Published: September 2006

Climate change could have significant impacts on the availability of freshwater and the frequency and severity of flooding, with major implications for society. The latest version of the Hadley Centre General Circulation Model, HadGEM1, includes the TRIP (total runoff including pathways) global river routing scheme. We have analysed the predicted changes in global river flow under the IPCC SRES A1B and A2 scenarios from HadGEM1‐TRIP simulations. Global total river flow was predicted to increase by 4–8% during the 2071–2100 period relative to 1961–1990, although there were large regional differences—for example, large increases in river flow in boreal regions and western Africa, and large decreases in river flow in southern Europe and North Africa. Significant changes in the seasonality of river flow could also occur, such as earlier peaks in spring runoff in boreal rivers due to earlier snow melt. In our simulations, large increases in monthly maximum flow and decreases in monthly minimum flow were found, although the increases in monthly maximum flow were generally larger. Thus, climate change is likely to increase the occurrence of both high and low flows, although the increased high flows could be dominant. © Crown Copyright 2006. Reproduced with the permission of the Controller of HMSO. Published by John Wiley & Sons, Ltd.
Synthesis and Characterization of Mixed‐Valent Manganese Phosphonate Cage Complexes
Authors: Shanmugam Maheswaran , Chastanet Guillaume , Mallah Talal , Sessoli Roberta , Teat Simon J. , Timco Grigore A. , Winpenny Richard E. P.
Published: September 2006

The reaction of phenylphosphonic acid (PhPO3H2) with the mixed‐valent basic oxo‐centered manganese triangle [Mn3O(O2CCMe3)6(py)3] (1; where py=pyridine) in the presence of a suitable base gives four different manganese clusters depending on the identity of the base. The syntheses and structural characterization of [Mn18(μ3‐O)8(PhPO3)14(O2CCMe3)12(py)6(H2O)2] (2), [Mn7(μ3‐O)3(O3PPh)3(O2CCMe3)8(py)3] (3), [Mn9Na(μ3‐O)4(μ4‐O)2(O3PPh)2(O2CCMe3)12(H2O)2(H2O)0.67(Py)0.33] (4), and [Mn13(μ3‐O)8(OMe)8(O3PPh)4(O2CCMe3)10] (5) are described. Complexes 4 and 5 are homovalent MnIII cages, while 2 and 3 contain divalent, trivalent, and/or tetravalent ions. All the manganese centers are valence‐localized, the octahedral MnIII sites being recognizable by marked Jahn–Teller distortions. The magnetic properties of compounds 2–5 have been investigated in the polycrystalline state by magnetic susceptibility and high‐field magnetization measurements, which reveal that spin ground states vary from 0≤S≥8. AC susceptibility measurements performed on 4 and 5, in the 1.6–10.0 K ranges show the presence of out of AC susceptibility signal (χM′′) for 4, and an effective energy barrier (Ueff) for the re‐orientation of the magnetization is found to be 17 K, but for 5, the χM′′ maximum is found to be below 1.5 K.
The Nature of Halogen⋅⋅⋅Halogen Synthons: Crystallographic and Theoretical Studies
Authors: Awwadi Firas F. , Willett Roger D. , Peterson Kirk A. , Twamley Brendan
Published: September 2006

A study of the halogen⋅⋅⋅halogen contacts in organic compounds using ab initio calculations and the results of previously reported crystallographic studies show that these interactions are controlled by electrostatics. These contacts can be represented by the geometric parameters of the CX1⋅⋅⋅X2C moieties (where θ1=CX1⋅⋅⋅X2 and θ2=X1⋅⋅⋅X2C; ri=X1⋅⋅⋅X2 distance). The distributions of the contacts within the sum of van der Waals radii (rvdW) versus θi (θ1=θ2) show a maximum at θ≈150° for X=Cl, Br, and I. This maximum is not seen in the distribution of F⋅⋅⋅F contacts. These results are in good agreement with our ab initio calculations. The theoretical results show that the position of the maximum depends on three factors: 1) The type of halogen atom, 2) the hybridization of the ipso carbon atom, and 3) the nature of the other atoms that are bonded to the ipso carbon atom apart from the halogen atom. Calculations show that the strength of these contacts decreases in the following order: I⋅⋅⋅I>Br⋅⋅⋅Br>Cl⋅⋅⋅Cl. Their relative strengths decrease as a function of the hybridization of the ipso carbon atom in the following order: sp2>sp>sp3. Attaching an electronegative atom to the carbon atom strengthens the halogen⋅⋅⋅halogen contacts. An electrostatic model is proposed based on two assumptions: 1) The presence of a positive electrostatic end cap on the halogen atom (except for fluorine) and 2) the electronic charge is anisotropically distributed around the halogen atom.
Optimized Synthesis of AMPA Receptor Antagonist ZK 187638 and Neurobehavioral Activity in a Mouse Model of Neuronal Ceroid Lipofuscinosis
Authors: Elger Bernd , Schneider Matthias , Winter Eric , Carvelli Lucia , Bonomi Marco , Fracasso Claudia , Guiso Giovanna , Colovic Milena , Caccia Silvio , Mennini Tiziana
Published: September 2006

Previous structure–activity relationship studies in the search for a potent, noncompetitiveα‐amino‐3‐(3‐hydroxy‐5‐methyl‐4‐isoxazolyl)propionic acid (AMPA) receptor antagonist led to 2,3‐dimethyl‐6‐phenyl‐12H‐[1,3]dioxolo[4,5‐h]imidazo[1,2‐c][2,3]benzodiazepine (ZK 187638). However, the first synthesis had some drawbacks regarding reagents, processes, and overall yield, which furthermore decreased when the synthesis was scaled up. Therefore, we now report a new synthetic route for this compound which requires fewer steps and is suited for large‐scale production. This compound significantly relieved the symptoms of neuromuscular deficit inmndmice, a model of neuronal ceroid lipofuscinosis with motor neuron dysfunction. After oral administration, the concentrations of the compound in the brain and spinal cord were about threefold higher than those in the plasma. In summary, this novel AMPA antagonist is accessible through an optimized synthetic route, has good neurobehavioral activity, oral bioavailability, and favorable brain penetration. This opens new possibilities for the treatment of devastating neurological diseases that are mediated by the AMPA receptor.
Chemoenzymatic Synthesis and Antimicrobial and Haemolytic Activities of Amphiphilic Bis(phenylacetylarginine) Derivatives
Authors: Castillo José A. , Infante M. Rosa , Manresa Àngels , Vinardell M. Pilar , Mitjans Montserrat , Clapés Pere
Published: September 2006

Novel bis(Nα‐phenylacetyl‐L‐arginine)‐α,ω‐alkanediamide dihydrochloride (bis(PhAcArg)) derivatives with antimicrobial activity were designed and synthesised by a chemoenzymatic strategy. The new structures consist of two Nα‐phenylacetyl‐L‐arginine moieties connected by an alkanediamine spacer chain of 6, 8, 10, 12, and 14 methylene units through amide bonds. The key step in the chemoenzymatic strategy is the double aminolysis of the Nα‐phenylacetyl‐L‐arginine methyl ester by the corresponding α,ω‐alkanediamine catalyzed by papain in ethanolic media. The compounds synthesised were tested as antimicrobials against 15 bacterial and 8 fungal species. The antimicrobial activity and selectivity depend strongly on the spacer chain length. The bis(PhAcArg) derivative with the spacer chain of 12 methylene groups gave the lowest MIC values against Gram‐positive bacteria, whereas that with 14 methylene units was the best against Gram‐negative bacteria. Interestingly, these novel compounds showed enhanced antibacterial activity relative to the lead compound, bis(Nα‐caproyl‐L‐arginine)‐1,3‐propanediamide dihydrochloride (C3(CA)2), and moderate antifungal activity. Moreover, tests of haemolytic activity toward human erythrocytes revealed that haemolysis increases with spacer chain length. Importantly, the compounds were classified as not irritating to eyes, with the exception of the compound with the spacer chain of 14 methylene groups, which was a slight eye irritant.
The role of Src in solid and hematologic malignancies
Authors: Alvarez Ricardo H. , Kantarjian Hagop M. , Cortes Jorge E.
Published: September 2006

c‐Src was the first protooncogene described and was among the first molecules in which tyrosine kinase activity was documented. c‐Src has been defined as a common modular structure that participates in much of the crosstalk between the cytoplasmic protein tyrosine kinases and tyrosine kinase receptors. Understanding the structure and function of this important class of protein kinases and elucidating the molecular signaling events mediated by c‐Src are important not only for identifying the critical pathways but also for designing new strategies to block or inhibit the action of these kinases. Despite the large amount of information available on c‐Src, its precise functions in cancer remain to be elucidated. Recently, there has been renewed interest in c‐Src as a molecular target for cancer therapy, and multiple c‐Src inhibitors are entering clinical trials. In this review, the authors describe the function and expression of c‐Src in human malignancies and the novel c‐Src inhibitors and their potential applications for cancer treatment. Cancer 2006. © 2006 American Cancer Society.
Fiber connections of the compact division of the posterior pallial amygdala and lateral part of the bed nucleus of the stria terminalis in the pigeon (Columba livia)
Authors: Atoji Yasuro , Saito Shouichiro , Wild J. Martin
Published: September 2006

The compact division of the posterior pallial amygdala (PoAc) and lateral part of the bed nucleus of the stria terminalis (BSTL) are components of the limbic system in the pigeon brain. In this study, we examined the position and fiber connections of these two nuclei by using Nissl staining and tract‐tracing methods. PoAc occupies a central division in the posterior pallial amygdala. BSTL faces the ventral horn of the lateral ventricle and extends between A 7.25 and A 10.50. PoAc and BSTL connect bidirectionally by the stria terminalis. PoAc connects reciprocally with two nuclear groups in the cerebrum: 1) a continuum consisting of the caudoventral nidopallium, lateral part of the caudoventral nidopallium (NCVl), subnidopallium beneath NCVl, and piriform cortex and 2) rostral areas of the hemisphere, including the frontolateral and frontomedial nidopallium and the densocellular part of the hyperpallium. Extratelencephalic projections of PoAc terminate in the dorsomedial thalamic nuclei and reach the lateral hypothalamic area via the hypothalamic part of the occipito‐mesencephalic tract. BSTL also connects reciprocally with two main regions: 1) the same continuum as for PoAc projections, except the piriform cortex and 2) rostral areas of the hemisphere, including the olfactory tubercle and nucleus accumbens. Extratelencephalic reciprocal connections are with the substantia nigra, nucleus subceruleus dorsalis, parabrachial nucleus, locus coeruleus, and nucleus of the solitary tract. The dorsomedial subdivision of the hippocampal formation projects massively to PoAc and BSTL. These findings indicate that PoAc and BSTL are important components of an interconnected neural circuit involving widespread regions of the neuraxis and mediating limbic‐visceral functions. J. Comp. Neurol. 499:161–182, 2006. © 2006 Wiley‐Liss, Inc.
Organization of primary afferent projections to the gracile nucleus of the dorsal column system of primates
Authors: Qi Hui‐Xin , Kaas Jon H.
Published: September 2006

In order to reveal the somatotopic organization of the gracile nucleus of the dorsal column–trigeminal complex, neuroanatomical tracers were injected subcutaneously into various parts of the hindlimb and tail of prosimian galagos, New World monkeys, and Old World monkeys. In most cases, tracers were injected bilaterally, and into more than one body part. In six cases, two different, distinguishable tracers were injected into the same hindlimb. Brainstem and spinal cord sections were processed for tracers transported by cutaneous afferents to terminations in the gracile nuclei. Foci of terminations were related to the cell‐cluster architecture of the gracile nuclei in sections processed for cytochrome oxidase or stained for cell bodies (Nissl stain). In all taxa, terminations labeled by the injections were distributed in a patchy fashion along the rostrocaudal length of the ipsilateral gracile nucleus. Terminations were largely but not completely focused within the cytochrome oxidase dense cell clusters. Across taxa, afferents from the tail, foot, lower leg, and upper leg terminated in a mediolateral sequence within the gracile nucleus. Afferents from the glabrous skin of toes 1–5 terminated in a ventromedial to dorsolateral sequence in owl, squirrel, and macaque monkeys, but an altered arrangement was seen in the galagos, with a ventrolateral location for toe 1. The use of two tracers in squirrel monkeys indicated that terminations from adjacent toes formed adjacent and largely segregated patches. Terminations of afferents from the plantar pad (sole) of the foot tended to surround those from the glabrous toes. J. Comp. Neurol. 499:183–217, 2006. © 2006 Wiley‐Liss, Inc.
Differential synaptology of vGluT2‐containing thalamostriatal afferents between the patch and matrix compartments in rats
Authors: Raju Dinesh V. , Shah Deep J. , Wright Terrence M. , Hall Randy A. , Smith Yoland
Published: September 2006

The striatum is divided into two compartments named the patch (or striosome) and the matrix. Although these two compartments can be differentiated by their neurochemical content or afferent and efferent projections, the synaptology of inputs to these striatal regions remains poorly characterized. By using the vesicular glutamate transporters vGluT1 and vGluT2, as markers of corticostriatal and thalamostriatal projections, respectively, we demonstrate a differential pattern of synaptic connections of these two pathways between the patch and the matrix compartments. We also demonstrate that the majority of vGluT2‐immunolabeled axon terminals form axospinous synapses, suggesting that thalamic afferents, like corticostriatal inputs, terminate preferentially onto spines in the striatum. Within both compartments, more than 90% of vGluT1‐containing terminals formed axospinous synapses, whereas 87% of vGluT2‐positive terminals within the patch innervated dendritic spines, but only 55% did so in the matrix. To characterize further the source of thalamic inputs that could account for the increase in axodendritic synapses in the matrix, we undertook an electron microscopic analysis of the synaptology of thalamostriatal afferents to the matrix compartments from specific intralaminar, midline, relay, and associative thalamic nuclei in rats. Approximately 95% of PHA‐L‐labeled terminals from the central lateral, midline, mediodorsal, lateral dorsal, anteroventral, and ventral anterior/ventral lateral nuclei formed axospinous synapses, a pattern reminiscent of corticostriatal afferents but strikingly different from thalamostriatal projections arising from the parafascicular nucleus (PF), which terminated onto dendritic shafts. These findings provide the first evidence for a differential pattern of synaptic organization of thalamostriatal glutamatergic inputs to the patch and matrix compartments. Furthermore, they demonstrate that the PF is the sole source of significant axodendritic thalamic inputs to striatal projection neurons. These observations pave the way for understanding differential regulatory mechanisms of striatal outflow from the patch and matrix compartments by thalamostriatal afferents. J. Comp. Neurol. 499:231–243, 2006. © 2006 Wiley‐Liss, Inc.
The numerical solution of third‐order boundary value problems using Sinc‐collocation method
Authors: Saadatmandi A. , Razzaghi M.
Published: September 2006

The Sinc‐collocation method is presented for solving boundary value problems for nonlinear third‐order differential equations. Properties of the Sinc‐collocation method required for our subsequent development are given and are utilized to reduce the computation of nonlinear third‐order boundary value problems to some algebraic equations. The method is computationally attractive and applications are demonstrated through illustrative examples. Copyright © 2006 John Wiley & Sons, Ltd.
Cooperative Interactions in Supramolecular Aggregates: Linear and Nonlinear Responses in Calix[4]arenes
Authors: Datta Ayan , Terenziani Francesca , Painelli Anna
Published: September 2006

The linear and nonlinear optical polarizabilities of donor–acceptor (D‐π‐A) chromophores in confined geometries of calix[4]arenes are investigated through a model for interacting polar‐polarizable molecules. Both the linear polarizability (α) and the first hyperpolarizability (β) decrease with increasing the interdipolar angle, as expected in the oriented‐gas picture. However, within the polar‐polarizable model we predict deviations from the additive result, irrespective of the interdipolar angle. Depending on the nature of the chromophore, electrostatic intermolecular interactions between polar and polarizable chromophores lead to cooperative damping or enhancement of the optical responses. Specifically, for chromophores whose ground state is dominated by the neutral D‐π‐A structure both α and β are suppressed with respect to the prediction of the oriented‐gas model, whereas the opposite holds true for chromophores whose ground state is dominated by the zwitterionic D+‐π‐A−. These results explain recent experimental data on a calix[4]arene functionalized with a donor–acceptor dye for nonlinear optical applications. Density functional theory calculations on the relevant crystal structure further support our interpretation.
Intercalated Smectic A Phases in Banana‐Shaped Liquid Crystals with Carbonate End Groups
Authors: Fodor‐Csorba Katalin , Jákli Antal , Vajda Anikó , Prasad S. Krishna , Shankar Rao Doddamane S. , Dong Ronald Y. , Xu Jiadi , Galli Giancarlo
Published: September 2006

Novel, symmetrical, bent‐core mesogens, namely substituted 1,3‐phenylenebis{4′‐[(ethoxycarbonyl)oxy]‐1,1′‐biphenyl}‐4‐carboxylates, are prepared with carbonate groups at both ends of the molecules. The mesophase properties are investigated for different electron‐donating and ‐withdrawing substituents connected to the central ring at different positions. These compounds exhibit nematic and/or smectic A intercalated (SmAint) mesophases. Electro‐optical studies show a very significant electric‐field‐induced biaxiality that is fast (<1 ms) and large (0.03) associated with a high birefringence (0.33 at 500 nm, 10 V μm−1 field) for the unsubstituted analogue. For one substance this effect is observable from above 100 °C down to room temperature. Such electric‐field‐induced biaxiality may find practical applications in fast electro‐optic modulation devices.
Flow cytometric assessment of autologous γδ T cells in patients with acute myeloid leukemia: Potential effector cells for immunotherapy?
Authors: Aswald Jorg M. , Wang Xing‐Hua , Aswald Sandra , Lutynski Andrzej , Minden Mark D. , Messner Hans A. , Keating Armand
Published: September 2006

Background:

γδ T cells are a rare component of the circulating innate immune system capable of exerting anti‐neoplastic activity. This population may be suitable for the adoptive immunotherapy of acute myeloid leukemia (AML). Little is known however, about the frequency and function of circulating γδ T cells in AML. The aim of the study was to enumerate peripheral blood γδ T cells in patients with AML and explore the feasibility of their use clinically.

Methods:

We compared the absolute circulating γδ T cell levels in 33 AML patients before and after treatment versus 20 healthy volunteers using flow cytometry. The function of γδ T cells was assessed by detection of intracelluar interferon‐γ (IFN‐γ) and cytotoxicity against leukemic blasts.

Results:

AML patients with high blast counts prior to induction chemotherapy had marginally decreased γδ T cell levels compared with healthy controls: median 38/μL versus 83/μL; P = 0.051. Sequential γδ T cell enumeration after induction showed significantly decreased counts in patients with a persistently high blast burden compared to patients with reduced but detectable residual disease (molecular maker or borderline bone marrow infiltration): median 7/μL versus 105/μL; P = 0.008. Patients with residual disease had significantly higher γδ T cell counts compared to those retested after they had achieved complete remission (CR); P = 0.0025. In CR, γδ T cell counts remained lower than those of healthy individuals: median 33/μL versus 83/μL, P = 0.030. We detected a sharp increase (on average, four‐fold higher than values in CR) of γδ T cells in patients in very early morphologic or molecular relapse. We also tested the functional properties of γδ T cells from patients with AML in CR. Flow cytometric assessment of IFN‐γ revealed similar numbers of γδ T cells expressing the T1 cytokine compared with healthy controls. We also showed that γδ T cells were able to kill leukemic target cells in vitro.

Conclusion:

Flow cytometric assessment of γδ T cells in patients with AML revealed quantitative shifts with respect to disease status. Our data suggest that γδ T cells warrant further investigation as potential therapeutic agents. © 2006 International Society for Analytical Cytology
Optimization of a flow cytometry‐based protocol for detection and phenotypic characterization of multipotent mesenchymal stromal cells from human bone marrow
Authors: Jones Elena A. , English Anne , Kinsey Sally E. , Straszynski Liz , Emery Paul , Ponchel Frederique , McGonagle Dennis
Published: September 2006

Background:

To study the biology of rare bone marrow (BM) multipotent mesenchymal stromal cells (MSCs), recognized protocols are needed. Colony‐forming unit‐fibroblast (CFU‐F) assays have historically been used for the enumeration of MSCs. However, the need to isolate and further analyze MSCs requires new strategies based on cell surface markers. The purpose of this work was to verify the phenotype of BM MSCs in vivo and to develop flow cytometry‐based methods for their evaluation.

Methods:

Pre‐enrichment with D7‐FIB‐conjugated microbeads, cell sorting for CD45lowD7‐FIB+LNGFR+ cells, and CFU‐F assay were used to confirm the phenotype of BM MSCs in vivo. Further phenotypic characterization of MSCs was performed using three‐color flow cytometry following pre‐enrichment or by direct four‐color flow cytometry. The sensitivity of direct flow cytometry/rare event analysis for the accurate enumeration of MSCs was validated using 85 samples from patients with neoplastic BM diseases.

Results:

In normal BM, a significant correlation was found between the frequencies of CFU‐Fs and CD45lowD7‐FIB+LNGFR+ cells (n = 19, R = 0.719, P = 0.001). Following cell sorting, ˜15% of these cells were clonogenic. The same cells were enriched using LNGFR‐based positive selection, CD45/Glycophorin A‐based depletion, or plastic adherence. CD45lowD7‐FIB+LNGFR+ cells expressed classic makers of cultured MSCs CD73/SH3 and CD105/SH2 and markers of stromal reticular cells CD106/VCAM and alkaline phosphatase. Novel markers were identified including leukemia inhibitory factor receptor and gp130. CD45lowD7‐FIB+LNGFR+ cells were increased fourfold in the floating fat fraction of normal BM aspirates. Their frequency was decreased in chronic lymphocytic leukemia (threefold, n = 13, P = 0.049) and chronic myelogenous leukemia (ninefold, n = 11, P = 0.001) compared with that in age‐matched controls (n = 26 and n = 31, respectively).

Conclusions:

This study demonstrates the usefulness of flow cytometry‐based methods for the detection, enumeration and further phenotypic analysis of BM MSCs. These findings have broad applications for the future evaluation of BM MSCs in health and disease. © 2006 International Society for Analytical Cytology
Stochastic sleeping with sink‐oriented connectivity and coverage in large‐scale sensor networks
Authors: Shi Gaotao , Liao Minghong
Published: September 2006

Maintaining a long network lifetime with stringent energy constraints on tiny sensor nodes presents a big challenge for the design of wireless sensor networks. A widely used energy consumption strategy is to turn off a node when it is transmitting or receiving. However, most existing scheduling algorithms depend on location or directional information. As a result, the energy cost and system complexity involved in obtaining such geometric information may compromise the effectiveness as a whole. In this paper, we analyse the shortcomings of geographic scheduling schemes maintaining a complete coverage and prove that the network lifetime is determined by the boundary nodes. We propose a probabilistic cellular automaton scheduling scheme, which does not need any node location or directional information and also provide a topology control protocol (S3C2), which schedules a node to sleep based on probabilistic cellular automaton and maintains a sink‐oriented connectivity and coverage. Extensive simulations are conducted to evaluate the performance of our proposed scheduling scheme and topology control protocol. Copyright © 2006 John Wiley & Sons, Ltd.
Membrane‐bound eotaxin‐3 mediates eosinophil transepithelial migration in IL‐4‐stimulated epithelial cells
Authors: Yuan Qian , Campanella Gabriele S. , Colvin Richard A. , Hamilos Daniel L. , Jones Krister J. , Mathew Anuja , Means Terry K. , Luster Andrew D.
Published: September 2006

Epithelial cells play an important role in orchestrating mucosal immune responses. In allergic‐type inflammation, epithelial cells control the recruitment of eosinophils into the mucosa. Th2‐type cytokine‐driven release of eosinophil‐active chemokines from epithelial cells directs eosinophil migration into the mucosal epithelium. CCR3, the main eosinophil chemokine receptor, regulates this process; however, the respective contribution of individual CCR3 ligands in eosinophil transepithelial migration is less well understood. Using an in vitro transepithelial chemotaxis system, we found that eotaxin‐3 produced by IL‐4‐stimulated airway epithelial cells and CCR3 on eosinophils exclusively mediate eosinophil transepithelial migration. Eotaxin‐3 protein levels were also increased in the nasal mucosal epithelium recovered from allergic patients as compared to non‐allergic patients. Surprisingly, eotaxin‐3 in IL‐4‐stimulated airway epithelial cells was predominantly cell surface bound, and the cell surface form was critical for eosinophil transepithelial migration. Eotaxin‐3 cell surface association was partially glycosaminoglycan (GAG) dependent, but was completely protein dependent, suggesting that eotaxin‐3 associates with both GAG and cell surface proteins. We thus provide evidence that cell surface‐associated eotaxin‐3 is the critical IL‐4‐dependent chemotactic signal mediating eosinophil transepithelial migration in the setting of allergic inflammation.
A Novel Europium Carbodiimide that Contains Isolated Europium Tetrahedra and Parallel Chains of Edge‐Sharing Open Handbag‐Like Eu6 Units
Authors: Liao Wuping , Englert Ulli , Dronskowski Richard
Published: September 2006

Eu2I2(NCN) is the first compound to contain discrete empty europium tetrahedra and infinite metal chains that are constructed from edge‐sharing Eu6 units with an open handbag‐like motif. The europium tetrahedra and chains are bridged by coordinating carbodiimide (NCN2–) anions in a three‐dimensional network. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
“Isomerism” of Coordination Modes and Numbers in Pentanuclear Organozinc Hydroxylamides: An Exercise in Subtle Substituent Size Effects
Authors: Ullrich Matthias , Berger Raphael J. F. , Lustig Christian , Fröhlich Roland , Mitzel Norbert W.
Published: September 2006

The first organometallic zinc hydroxylamides [Zn(RZn)4(ONMe2)6] (1: R = Me; 2: R = iPr) and [Zn(EtZn)4(ONEt2)6] (3) have been prepared by alkane elimination from dialkylzinc solutions upon treatment with N,N‐dialkylhydroxylamines. The molecular structures of 1 and 2 reveal that a subtle change in the constitution of the aggregates can make a striking difference. By the simple exchange of the MeZn+ groups with iPrZn+ groups, the coordination number of the central Zn2+ nucleus increases from four (1) to six (2). The two cluster types are unprecedented in both hydroxylamine and organometallic chemistry. Compounds 1 and 3 adopt a doubly bridged fenestrane‐like Zn5N6O6 core with two dangling NR2 moieties, whereas iPrZn species 2 comprises an octahedroid backbone with all donor atoms attached to the five Zn nuclei with the maintenance of the same heteroatom composition as 1 and 3. Variable‐temperature 13C NMR experiments of all‐ethyl cluster 3 reveal that the R2NO– ligands rapidly exchange between the RZn+ and Zn2+ cations. This process is rationalised by a plausible model which also points out that the core structure of 3 could be an intermediate motif in the observed heteroatom connectivity exchange. In line with this, computational investigations reveal that both skeletons are very similar in energy. In sum, the coordination flexibility of the hydroxylamide ligand makes this group of organometallic zinc complexes a highly dynamic family of cluster compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Voltammetric Behavior of Antileukemia Drug Glivec. Part II – Redox Processes of Glivec Electrochemical Metabolite
Authors: Diculescu Victor Constantin , Vivan Marilene , Brett Ana Maria Oliveira
Published: September 2006

Glivec is a newly developed drug that belongs to the class of 2‐phenylaminopyrimidine. It is a potent inhibitor of ABL‐kinase, the main clinical manifestation of chronic myelogenous leukemia (CML). Based on its activity on CML, glivec is undergoing extensive evaluation for its activity against other tumor types. Detection and quantitation of glivec in biological fluids or cells is thus very important. The antileukemia drug glivec undergoes oxidation at glassy carbon electrodes and involves the formation of an oxidation product, Pglivec. The adsorption of Pglivec at the GCE surface yields a compact monolayer allowing an electrochemical study of this compound adsorbed at the GCE surface. The reversible redox reaction of the adsorbed Pglivec is pH dependent and occurs with the transfer of 2 electrons and 2 protons. The surface standard potential and the rate constant of the heterogeneous electrochemical reaction were calculated using cyclic voltammetry to be Eθ′=+180 mV and k=15.5 s−1, respectively. The total surface concentration of adsorbed Pglivec is 2.5×10−12 mol cm−2. The analytical determination of glivec was carried out by differential pulse voltammetric measurement of the anodic peak current corresponding to either the oxidation peak of glivec or the oxidation peak of Pglivec adsorbed on the GCE surface. The limits of detection of glivec and adsorbed Pglivec based on three times the noise level are 3.3×10−8 M and 2.9×10−10 M, respectively.
Electroanalytical Approach to Evaluate Antioxidant Capacity in Honeys: Proposal of an Antioxidant Index
Authors: Ávila Mónica , Crevillén Agustín G. , González María Cristina , Escarpa Alberto , Hortigüela Lucía Vela , de Lorenzo Carretero Cristina , Pérez Martín Rosa Ana
Published: September 2006

A novel electrochemical route to estimate the antioxidant capacity in honey samples is proposed just using flow injection analysis. The analytical strategy involved the selective oxidation of polyphenolic compounds using two different target potentials, +0.8 and +0.5 V, at two different pHs. An oxidation current obtained at the fixed potential was used as an analytical guide of the antioxidant activity of the target honeys. Chemometrics (correlation and principal component analysis, PCA) demonstrated the significance of the electrochemical protocol versus the traditional spectrophotometric ones in the evaluation of antioxidant capacity and revealed the role of detection potential as a screening variable. The proposed protocol is very simple and fast. However, the most relevant merit of the electrochemical procedure is its inherent versatility which allows the evaluation of the antioxidant activity under predesigned controlled oxidation conditions. In addition, since intercept was statistically zero, its corresponding antioxidant content using just a calibration factor is proposed thus simplifying the calibration‐analysis process. As a result, an electrochemical antioxidant index (EAI) is proposed.
Electrochemical Biosensors Based on Layer‐by‐Layer Assemblies
Authors: Zhao Wei , Xu Jing‐Juan , Chen Hong‐Yuan
Published: September 2006

Layer‐by‐layer (LBL) assemblies, which have undergone great progress in the past decades, have been used widely in the construction of electrochemical biosensors. The LBL assemblies provide a strategy to rationally design the properties of immobilized films and enhance the performance of biosensors. The following review focuses on the application of LBL assembly technique on electrochemical enzyme biosensors, immunosensors and DNA sensors.
Parallel optimization and genotyping of multiple single‐nucleotide polymorphism markers by sample pooling approach using cycling‐gradient CE with multiple injections
Authors: Minarik Marek , Benesova Lucie , Fantova Lucie , Horacek Jiri , Heracek Jiri , Loukola Anu
Published: September 2006

Increasing importance of single‐nucleotide polymorphisms (SNPs) in determination of disease susceptibility or in prediction of therapy response brings attention of many molecular diagnostic laboratories to simple and low‐cost SNP genotyping methodologies. We have recently introduced a mutation detection technique based on analysis of homo‐ and heteroduplex PCR fragments resolved in cycling temperature gradient conditions on a conventional multicapillary‐array DNA sequencer. The main advantage of this technique is in its simplicity with no requirement for sample cleanup prior to the analysis. In this report we present a practical application of the technology for genotyping of SNP markers in two separate clinical projects resulting in a combined set of 44 markers screened in over 500 patients. Initially, a design of PCR primers and conditions was performed for each SNP marker. Then, optimization of CE running conditions (limited just to the proper selection of temperature cycling) was performed on pools of 20 DNA samples to increase the probability of having each of the two allele types represented in the sample. After selecting the optimum conditions, screening of markers in patients was performed using a multiple‐injection approach for further acceleration of the sample throughput. The rate of successful optimization of experimental conditions without any pre‐selection based on the SNP sequence or melting characteristics was 80% from the initial SNP marker candidates. By studying the failed markers, we attempt to identify critical factors enabling successful typing. The presented technique is very useful for low to medium sized SNP genotyping projects mostly applied in pharmacogenomic research as well as in clinical diagnostics. The main advantages include low cost, simple setup and validation of SNP markers.
Channel change, bankfull and effective discharges on a vertically accreting, meandering, gravel‐bed river
Authors: Gomez B. , Coleman S. E. , Sy V. W. K. , Peacock D. H. , Kent M.
Published: September 2006

Along the lower reaches of the Waipaoa River, New Zealand, cross‐section survey data indicate there was a 23 per cent decrease in bankfull width and a 22 per cent reduction in channel cross‐section area between 1948 and 2000, as the channel responded to increased inputs of fine (suspended) sediment following deforestation of the headwaters in late C19 and early C20. We determined the bankfull discharge within a ∼39 km long reach by routing known discharges through the one‐dimensional MIKE 11 flow model. The model runs suggest that the bankfull discharge varies between ∼800 and ∼2300 m3 s−1 and that the average recurrence interval is 4 ± 2 years on the annual maximum series; by contrast, the effective flow (360 m3 s−1) is equaled or exceeded three times a year. The variability in bankfull discharge arises because the banks tend to be lower in places where flood flows are constricted than in reaches where overbank flow is dispersed over a wide area, and because scour has counteracted aggradation in some locations. There is no downstream variation in Shields stress, or in relative shear stress, within the study reach. Bankfull shear stress is, on average, five times greater than the shear stress required to initiate motion. At the effective discharge it is more than twice the threshold value. The effective discharge probably has more relevance than the bankfull discharge to the overall picture of sediment movement in the lower reaches of the Waipaoa River but, because width is constrained by the stability and resistance of the bank material to erosion during high flows that also scour the bed, the overall channel geometry is likely determined by discharges at or near bankfull. Copyright © 2006 John Wiley & Sons, Ltd.