bluuebunny/crossref_metadata_2025 huggingface dataset:
The risks of exposure to internal emitters
Authors: Wakeford Richard
Published: July 2007

The risks to health from internally deposited radionuclides have received considerable attention in recent years. There are significant issues concerned with exposure to internal emitters beyond those associated with the risks posed by external sources of penetrating ionizing radiations, and these issues lead to additional uncertainty in risk estimates pertaining to internal emitters. There is, however, no firm evidence that the risks from internally deposited radioactive material have been seriously underestimated by scientific review groups, but the uncertainties associated with the risks of exposure to internal emitters need to be taken into account in radiological protection. Copyright © 2007 John Wiley & Sons, Ltd.
Towards stereoselective radiosynthesis of α‐[11C]methyl‐substituted aromatic α‐amino acids – a challenge of creation of quaternary asymmetric centre in a very short time
Authors: Popkov Alexander , Nádvorník Milan , Kružberská Pavla , Lyčka Antonín , Lehel Szabolcs , Gillings Nicholas
Published: July 2007

In positron emission tomography (PET) α‐methyl amino acids have two potential applications: As analogues of neutransmitter precursors for the study of neurodegenerative diseases; as non‐metabolised analogues of proteinogenic amino acids for the study of amino acid uptake into normal and cancer cells.

Clinical applications of such amino acids are strongly limited due to their poor availability. We carried out [11C]methylation of metalocomplex synthons derived from protected DOPA or tyrosine. For [11C]methylation, sodium hydroxide (5 mg of fine dry powder) was sealed in a vial, which was flushed with dry nitrogen before addition of a solution of the complex (10 mg) and 11CH3I in 1,3‐dimethylimidazolidin‐2‐one (300 µl). After 10 min at 25°C, a 9% radiochemical yield (decay‐corrected) of a mixture of the diastereomeric α‐[11C]methylDOPA complexes or a 7% radiochemical yield of a mixture of the diastereomeric α‐[11C]methyltyrosine complexes was achieved. Individual diastereomers were successfully separated by preparative HPLC, diluted with excess of water and extracted on C18 cartridges. Optimisation of the procedure including hydrolysis of the complexes (hydrolytic deprotection of enantiomerically pure amino acids) and subsequent purification of the enantiomers of α‐[11C]methylDOPA and α‐[11C]methyltyrosine is underway. Copyright © 2007 John Wiley & Sons, Ltd.
Opportunities for isotopic labelling via phase‐tagged synthesis with organogermanium linkers
Authors: Spivey Alan C. , Martin Laetitia J. , Noban Catherine , Jones Teyrnon C. , Ellames George J. , Kohler Andrew D.
Published: July 2007

Strategies for the use of germanium‐based linkers for the phase‐tagged synthesis of isotopically labelled intermediates are described. Protocols of potential use in the devolatilization of volatile intermediates prepared from [14C]‐CO2 and [14C]‐PhBr to aid ADME studies on drug substances and their metabolites are discussed in relation to SR47035 (an advanced intermediate en‐route to the 5‐HT2 receptor antagonist SR46349B) and 4‐amino‐4‐phenylpiperidine (a key intermediate in the synthesis of NK3 receptor antagonist SR142801, osanetant). Additionally, protocols with potential for the preparation of [123I] and [18F]‐labelled SPECT/PET imaging/diagnostic agents are discussed in relation to an [123I]‐labelled analogue of SR141716 (rimonabant, a CB1 receptor antagonist) and 6‐[18F]‐(S)‐DOPA (for diagnosis of Parkinson's disease). Copyright © 2007 John Wiley & Sons, Ltd.
Production of radioisotopes in the BR2 high‐flux reactor for applications in nuclear medicine and industry
Authors: Ponsard Bernard
Published: July 2007

The BR2 reactor, put into operation in 1963 and refurbished in 1995–1997, is a 100 MW high‐flux ‘materials testing reactor’ which provides thermal neutron fluxes up to 1015 n/cm2 s. The production of radioisotopes, characterized by high specific activities, is carried out in dedicated in‐core devices within standard irradiation cycles of 3–4 weeks and in accordance with a ‘quality system’ that has been certified to the requirements of the ‘EN ISO 9001:2000’ in November 2003. Due to its operating flexibility, its reliability and its production capacity, the BR2 reactor is considered as a major facility for a routine supply of radioisotopes such as 99Mo (99mTc), 131I, 133Xe, 192Ir, 186Re, 153Sm, 169Er, 90Y, 32P, 188W (188Re), 203Hg, 82Br, 79Kr, 41Ar, 125I, 177Lu, 89Sr, 60Co, 169Yb, 147Nd, etc. It will continue to play this key role with the possibility of an extra operating cycle from 2006 and the realization of various ‘test’ irradiations to develop the production of new radioisotopes. Some irradiation devices allow the loading and unloading of irradiated targets during the operation of the reactor. Hot cells and storage facilities are available to prepare and organize the shipment of the irradiated targets to dedicated processing facilities. Copyright © 2007 John Wiley & Sons, Ltd.
The use of biocatalysis in the synthesis of labelled compounds
Authors: Allen John , Brasseur Denis M. , De Bruin Béatrice , Denoux Mireille , Pérard Serge , Philippe Nicolas , Roy Sébastien N.
Published: July 2007

Since most biotransformations are highly chemo‐, regio‐ and stereoselective, they offer many opportunities for the synthesis of compounds that are not easily attainable by classical organic chemistry, The catalytic properties of the cytochrome P450 (CYP450) enzymes of microorganisms can be exploited to produce suitable N‐, S‐ or O‐dealkylated precursors, which can be realkylated with the appropriate labelled reagent. These enzymes are also well reported for hydroxylation of activated or nonactivated carbon centres, to produce drug metabolites. Nevertheless, to use such enzymes, a whole cell system is preferred due to the need for cofactor regeneration. Nitrile hydrolysing enzymes also attract attention, due to their ability to selectively hydrolyse nitrile derivatives under mild conditions. The scope of such biotransformations is discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Long‐term exposure to dieldrin reduces γ‐aminobutyric acid type A and N‐methyl‐D‐aspartate receptor function in primary cultures of mouse cerebellar granule cells
Authors: Babot Zoila , Vilaró M. Teresa , Suñol Cristina
Published: July 2007

The organochlorine pesticide dieldrin is a persistent organic pollutant that accumulates in the fatty tissue of living organisms. In mammals, it antagonizes the GABAA receptor, producing convulsions after acute exposure. Although accumulation in human brain has been reported, little is known about the effects of long‐term exposure to dieldrin in the nervous system. Homeostatic control of the balance between excitation and inhibition has been reported when neuronal activity is chronically altered. We hypothesized that noncytotoxic concentrations of dieldrin could decrease glutamatergic neurotransmission as a consequence of a prolonged reduction in GABAA receptor function. Long‐term exposure of primary cerebellar granule cell cultures to 3 μM dieldrin reduced the GABAA receptor function to 55% of control, as measured by the GABA‐induced 36Cl− uptake. This exposure produced a significant reduction (∼35%) of the NMDA‐induced increase in [Ca2+]i and of the [3H]MK‐801 binding, which was not accompanied by a reduction in the NMDA receptor subunit NR1, as determined by Western blot. Consistent with the decreased NMDA receptor function, dieldrin‐treated cultures were insensitive to an excitotoxic stimulus induced by exposure to high potassium. In summary, we report that the chronic reduction of GABAA receptor function induced by dieldrin decreases the number of functional NMDA receptors, which may be attributable to a mechanism of synaptic scaling. These effects could underlie neural mechanisms involved in cognitive impairment produced by low‐level exposure to dieldrin. © 2007 Wiley‐Liss, Inc.
In vitro neural injury model for optimization of tissue‐engineered constructs
Authors: Cullen D. Kacy , Stabenfeldt Sarah E. , Simon Crystal M. , Tate Ciara C. , LaPlaca Michelle C.
Published: August 2007

Stem cell transplantation is a promising approach for the treatment of traumatic brain injury, although the therapeutic benefits are limited by a high degree of donor cell death. Tissue engineering is a strategy to improve donor cell survival by providing structural and adhesive support. However, optimization prior to clinical implementation requires expensive and time‐consuming in vivo studies. Accordingly, we have developed a three‐dimensional (3‐D) in vitro model of the injured host–transplant interface that can be used as a test bed for high‐throughput evaluation of tissue‐engineered strategies. The neuronal‐astrocytic cocultures in 3‐D were subjected to mechanical loading (inducing cell death and specific astrogliotic alterations) or to treatment with transforming growth factor‐β1 (TGF‐β1), inducing astrogliosis without affecting viability. Neural stem cells (NSCs) were then delivered to the cocultures. A sharp increase in the number of TUNEL+ donor cells was observed in the injured cocultures compared to that in the TGF‐β1‐treated and control cocultures, suggesting that factors related to mechanical injury, but not strictly astrogliosis, were detrimental to donor cell survival. We then utilized the mechanically injured cocultures to evaluate a methylcellulose‐laminin (MC‐LN) scaffold designed to reduce apoptosis. When NSCs were codelivered with MC alone or MC‐LN to the injured cocultures, the number of caspase+ donor cells significantly decreased compared to that with vehicle delivery (medium). Collectively, these results demonstrate the utility of an in vitro model as a preanimal test bed and support further investigation of a tissue‐engineering approach for chaperoned NSC delivery targeted to improve donor cell survival in neural transplantation. © 2007 Wiley‐Liss, Inc.
Regulation of membrane association and kinase activity of Cdk5–p35 by phosphorylation of p35
Authors: Sato Ko , Zhu Ying‐Shan , Saito Taro , Yotsumoto Kensuke , Asada Akiko , Hasegawa Masato , Hisanaga Shin‐ichi
Published: August 2007

Although protein kinase Cdk5–p35 is important in many aspects of the development and function of the central nervous system, relatively little is known about its regulation. In the present study, we examined the relationship between the association of this kinase with membranes and its activity in perinatal and adult rat brains. Cdk5–p35 in perinatal brain exhibited higher activity than that found in adult tissue. Gel filtration chromatography revealed that a portion of Cdk5–p35 from fetal brain occurred as a soluble complex, whereas Cdk5–p35 in adult brain occurred predominantly as a membrane‐bound complex. Furthermore, soluble Cdk5–p35 in perinatal brain displayed elevated kinase activity, whereas membrane‐bound Cdk5–p35 was highly active only in the presence of detergent. This more active soluble form of Cdk5–p35 correlated to a form in which p35 was phosphorylated, whereas the less active membrane‐bound form of Cdk5 correlated to the dephosphorylated form of p35, as evidenced by a downward shift in electrophoretic mobility. Cdk5 activity and transition from soluble to membrane‐associated compartments could be modulated by conditions that affected the phosphorylation or dephosphorylation of p35. For example, dephosphorylation of p35 in brain extracts was suppressed by selective inhibition of protein phosphatase‐1. Together, these results suggest that the kinase activity of Cdk5–p35 is regulated through its association with membranes, which in turn is under the control of Cdk5‐dependent phosphorylation and protein phosphatase‐1–dependent dephosphorylation of p35. © 2007 Wiley‐Liss, Inc.
Markers of mRNA stabilization and degradation, and RNAi within astrocytoma GW bodies
Authors: Moser Joanna J. , Eystathioy Theophany , Chan Edward K.L. , Fritzler Marvin J.
Published: July 2007

GW bodies (GWBs) are unique cytoplasmic structures that contain the mRNA binding protein GW182 and other proteins involved in mRNA processing pathways. The rationale for this study arose from clinical studies indicating that 33% of patients with GWB autoantibodies have a motor/sensory neuropathy and/or ataxia. The novelty of this study is the identification of GWBs in astrocytes and astrocytoma cells within cell bodies and cytoplasmic projections. Astrocytoma GWBs exhibit complex heterogeneity with combinations of LSm4 and XRN1 as well as Ago2 and Dicer, key proteins involved in mRNA degradation and RNA interference, respectively. GWB subsets contained the mRNA transport and stabilization proteins SYNCRIP, hnRNPA1, and FMRP, not previously described as part of the GWB complex. Immunoprecipitation of astrocytoma GWBs suggested that Dicer, hDcp, LSm4, XRN1, SYNCRIP, and FMRP form a multiprotein complex. GWBs are likely involved in a number of regulatory mRNA pathways in astrocytes and astrocytoma cells. © 2007 Wiley‐Liss, Inc.
Rapid promoter analysis in developing mouse brain and genetic labeling of young neurons by doublecortin‐DsRed‐express
Authors: Wang Xiuyun , Qiu Runxiang , Tsark Walter , Lu Qiang
Published: August 2007

Characterization of neural promoter/enhancers is essential for understanding gene regulation during brain development and provides useful genetic tools. However, it relies on the use of transgenic mice. We report a method for the rapid in vivo analysis of neural promoter/enhancers in the developing mouse brain and its application in the isolation of the doublecortin (DCX) promoter/enhancer for genetic labeling of young neurons. In the present study, we demonstrated that reporter genes introduced into the developing mouse cerebral cortex by in utero electroporation can achieve promoter/enhancer‐specific patterns of expression. We used the in utero electroporation system to isolate a genomic fragment of the doublecortin gene that can direct reporter expression faithful to doublecortin in young neurons of the cerebral cortex. Finally, we showed that the DCX promoter identified via electroporation could reproduce doublecortin expression in the entire central nervous system in DCX‐DsRed‐express transgenic mice. The results of our study provide a convenient, reliable, and rapid method for in vivo analysis of neural promoter/enhancers in the developing mouse brain. © 2007 Wiley‐Liss, Inc.
Neocortical plasticity deficits in fetal alcohol spectrum disorders: Lessons from barrel and visual cortex
Authors: Medina Alexandre E. , Krahe Thomas E.
Published: August 2007

Fetal Alcohol Spectrum Disorder (FASD) is characterized by a constellation of behavioral and physiological abnormalities, including learning and sensory deficits. There is growing evidence that abnormalities of neuronal plasticity underlie these deficits. However, the cellular and molecular mechanisms by which prenatal alcohol exposure disrupts neuronal plasticity remain elusive. Recently, studies with the barrel and the visual cortex as models to study the effects of early alcohol exposure on neuronal plasticity shed light on this subject. In this Mini‐Review, we discuss the effects of ethanol exposure during development on neuronal plasticity and suggest environmental and pharmacological approaches to ameliorate these problems. © 2007 Wiley‐Liss, Inc.
Distinct spatial and temporal activation of caspase pathways in neurons and glial cells after excitotoxic damage to the immature rat brain
Authors: Villapol Sonia , Acarin Laia , Faiz Maryam , Castellano Bernardo , Gonzalez Berta
Published: August 2007

Although cleaved caspase‐3 is known to be involved in apoptotic cell death mechanisms in neurons, it can also be involved in a nonapoptotic role in astrocytes after postnatal excitotoxic injury. Here we evaluate participation of upstream pathways activating caspase‐3 in neurons and glial cells, by studying the intrinsic pathway via caspase‐9, the extrinsic pathway via caspase‐8, and activation of the p53‐dependent pathway. N‐methyl‐D‐aspartate (NMDA) was injected intracortically in 9‐day‐old postnatal rats, which were sacrificed at several survival times between 4 hr postlesion (pl) and 7 days pl. We analyzed temporal and spatial expression of caspase‐8, caspase‐9, and p53 and correlation with neuronal and glial markers and caspase‐3 activation. Caspase‐9 was significantly activated at 10 hpl, strongly correlating with caspase‐3. It was present mainly in damaged cortical and hippocampal neurons but was also seen in astrocytes and oligodendrocytes in layer VI and corpus callosum (cc). Caspase‐8 showed a diminished correlation with caspase‐3. It was present in cortical neurons at 10–72 hpl, showing layer specificity, and also in astroglial and microglial nuclei, mainly in layer VI and cc. p53 Expression increased at 10–72 hpl but did not correlate with caspase‐3. p53 Was seen in neurons of the degenerating cortex and in some astrocytes and microglial cells of layer VI and cc. In conclusion, after neonatal excitotoxicity, mainly the mitochondrial intrinsic pathway mediates neuronal caspase‐3 and cell death. In astrocytes, caspase‐3 is not widely correlated with caspase‐8, caspase‐9, or p53, except in layer VI‐cc astrocytes, where activation of upstream cascades occurs. © 2007 Wiley‐Liss, Inc.
Predicting summer rainfall in the Yangtze River basin with neural networks
Authors: Hartmann Heike , Becker Stefan , King Lorenz
Published: August 2007

Summer rainfall in the Yangtze River basin is predicted using neural network techniques. Input variables (predictors) for the neural network are the Southern Oscillation Index (SOI), the East Atlantic/Western Russia (EA/WR) pattern, the Scandinavia (SCA) pattern, the Polar/Eurasia (POL) pattern and several indices calculated from sea surface temperatures (SST), sea level pressures (SLP) and snow data from December to April for the period from 1993 to 2002. The output variable of the neural network is rainfall from May to September for the period from 1994 to 2002, which was previously classified into six different regions by means of a principal component analysis (PCA). Rainfall is predicted from May to September 2002.

The winter SST and SLP indices are identified to be the most important predictors of summer rainfall in the Yangtze River basin. The Tibetan Plateau snow depth, the SOI and the other teleconnection indices seem to be of minor importance for an accurate prediction. This may be the result of the length of the available time series, which does not allow a deeper analysis of the impact of multi‐annual oscillations.

The neural network algorithms proved to be capable of explaining most of the rainfall variability in the Yangtze River basin. For five out of six regions, our predictions explain at least 77% of the total variance of the measured rainfall. Copyright © 2007 Royal Meteorological Society
Mass balance of a slope glacier on Kilimanjaro and its sensitivity to climate
Authors: Mölg Thomas , Cullen Nicolas J. , Hardy Douglas R. , Kaser G. , Klok L.
Published: August 2007

Meteorological and glaciological measurements obtained at 5873 m a.s.l. on Kersten Glacier, a slope glacier on the southern flanks of Kilimanjaro, are used to run a physically‐based mass balance model for the period February 2005 to January 2006. This shows that net shortwave radiation is the most variable energy flux at the glacier‐atmosphere interface, governed by surface albedo. The majority of the mass loss (∼65%) is due to sublimation (direct conversion of snow/ice to water vapour), with melting of secondary importance. Sensitivity experiments reveal that glacier mass balance is 2–4 times more sensitive to a 20% precipitation change than to a 1 °C air temperature change. These figures also hold when the model is run with input data representative of a longer term (1979–2004) mean period. Results suggest that a regional‐scale moisture projection for the 21st century is crucial to a physically‐based prediction of glacier retention on Africa's highest mountain. Copyright © 2007 Royal Meteorological Society
A Middle Weichselian interstadial lake deposit on Sejerø, Denmark: macrofossil studies and dating
Authors: Bennike Ole , Houmark‐Nielsen Michael , Wiberg‐Larsen Peter
Published: July 2007

Studies of lake sediments on Sejerø in southern Kattegat indicate a treeless arctic environment with the dwarf shrub Salix polaris, herbs and wetland mosses. The mean July temperature was around 8 to 10°C. An AMS radiocarbon age determination of a Salix twig yielded an age of around 36 000 14C yr BP, which is in accordance with previous conventional dating of bulk sediment samples. Copyright © 2006 John Wiley & Sons, Ltd.
Collisionally induced dephasing and rotational energy transfer in the CO2 Fermi dyad ‘blue’ Q‐branch 1388 cm−1
Authors: Arakcheev V. G. , Kireev V. V. , Morozov V. B. , Olenin A. N. , Tunkin V. G. , Valeev A. A. , Yakovlev D. V.
Published: July 2007

In this paper we present a comparative analysis of two alternative approaches to the description of the rotational energy transfer (RET) in the ‘blue’ (1388 cm−1) Q‐branch of the CO2ν1/2ν2 Fermi dyad based on the simplified spectral exchange (SE) and rotational relaxation (RR) models. The analysis was carried out using a special approximation error minimization procedure for fitting the theoretical model to experimental impulse responses obtained by time‐domain CARS at low and moderate densities. At densities ρ≥ 1 amagat, the collisional dephasing (CD) contribution to the linewidth substantially prevails over the width attributed to the rotational structure. The impulse response beating analysis and the fitting results clearly proved that in contrast to the ‘red’ (1285 cm−1) band, the SE model is more appropriate in comparison with the RR model for a description of the RET in the ‘blue’ Q‐branch. Copyright © 2007 John Wiley & Sons, Ltd.
Challenges in the nutrition of organic pigs
Authors: Zollitsch Werner
Published: July 2007

The need to develop feeding strategies for organic pig husbandry is discussed. Successful performance of the farming system can only be achieved if the production process is optimised and controlled and essential inputs are available. When monogastric livestock such as pigs are integrated into an organic farming system, some nutritional inputs may be scarce. In the nutrition of organic pigs, two areas might be identified as the most important challenges: (1) balancing the supply and requirements of essential amino acids without relying too much on external feedstuffs and (2) developing and implementing nutritional concepts which help to improve animal health status. Copyright © 2007 Society of Chemical Industry
Rationally Designing Molecularly Imprinted Polymer towards Predetermined High Selectivity by Using Metal as Assembled Pivot
Authors: Li Songjun , Liao Cong , Li Wuke , Chen Yifeng , Hao Xiao
Published: July 2007

This article presents an original work aiming at rationally designing a molecularly imprinted polymer (MIP) towards high selective recognition. Assembled with (S)‐naproxen as a template and 4‐vinylpyridine as a functional monomer, a certain amount of cobalt, as pivot, is added for the preparation of MIP. The result indicates that the use of pivot plays obviously a positive role in increasing the specificity of MIP, so as to adsorb more for the template and less for its enantiomer. Related information indicates that this, in logic, can be a result of increasing match between binding sites and the templates, which makes the polymer capable of selectively recognizing the imprint species.

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Water‐Soluble pH‐Responsive Dendritic Core‐Shell Nanocarriers for Polar Dyes Based on Poly(ethylene imine)
Authors: Xu Shangjie , Luo Ying , Haag Rainer
Published: July 2007

A simple general synthetic concept to build dendritic core‐shell architectures with pH‐labile linkers based on hyperbranched PEI cores and biocompatible PEG shells is presented. Using these dendritic core‐shell architectures as nanocarriers, the encapsulation and transport of polar dyes of different sizes is studied. The results show that the acid‐labile nanocarriers exhibit much higher transport capacities for dyes than unfunctionalized hyperbranched PEI. The cleavage of imine bonds and controlled release of the polar dyes revealed that weak acidic condition (pH ≈ 5.0) could cleave the imine bonds linker and release the dyes up to five times faster than neutral conditions (pH = 7.4).

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Cation‐Dependent Switching of DNA Nanostructures
Authors: He Yu , Tian Ye , Chen Yi , Ye Tao , Mao Chengde
Published: July 2007

DNA is a versatile building material for nanoconstruction because of its remarkable molecular‐recognition capability and well‐predicted duplex conformation. A number of DNA motifs have been engineered, which can assemble into well‐defined nanostructures in Mg2+‐containing buffer solution. XRD studies reveal that the DNA conformation is slightly influenced by divalent cations (such as Mg2+ or Ca2+). This phenomenon can be utilized in DNA self‐assembly for regulating self‐assembled DNA nanostructures. As an initial step, a symmetric cross motif forms flat, periodic, 2D lattices in Mg2+‐containing solutions, but long nanofibers in Ca2+‐containing solutions. The obtained DNA fibers can serve as templates to fabricate CaCO3 nanotubes and nanowires.

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Synthesis and Properties of Amphiphilic Star Polysulfides
Authors: Wang Lei , Kilcher Giona , Tirelli Nicola
Published: July 2007

We here present the synthesis and characterisation of linear and star‐shaped amphiphilic block copolymers based on hydrophobic polysulfides (poly(propylene sulfide), PPS) and hydrophilic polyethers (poly(ethylene glycol), PEG). We also discuss the proof of the principle of their responsiveness to oxidising conditions. In a water environment, these polymers aggregate in the form of sub‐micron carriers that, due to the sensitivity to oxidation reactions typical of PPS, can be used for responsive drug delivery. In this first study we have focused on the study of large aggregates, which do not apparently show dramatic differences in behaviour when polymer chains with different degrees of branching are studied.

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Self Assembly and Optical Properties of Dendrimer Nanocomposite Multilayers
Authors: Balogh Lajos P. , Redmond Shawn M. , Balogh Peter , Tang Houxiang , Martin David C. , Rand Stephen C.
Published: July 2007

Ultrathin multilayers are important for electrical and optical devices, as well as for immunoassays, artificial organs, and for controlling surface properties. The construction of ultrathin multilayer films by electrostatic layer‐by‐layer deposition proved to be a popular and successful method to create films with a range of electrical, optical, and biological properties. Dendrimer nanocomposites (DNCs) form highly uniform hybrid (inorganic–organic) nanoparticles with controlled composition and architecture. In this work, the fabrication, characterization, and optical properties of ultrathin dendrimer/poly(styrene sulfonate) (PSS) and silver–DNC/PSS nanocomposite multilayers using layer‐by‐layer (LbL) electrostatic assembly techniques are described. UV‐vis spectra of the multilayers were found to be a combination of electronic transitions of the surface plasmon peaks, and the regular frequency modulations attributable to the multilayered film structure. The modulations appeared as the consequence of the highly regular and non‐intermixed multilayer growth as a function of the resulting structure. A simple model to explain the experimental data is presented. Use of DNCs in multilayers results in abrupt, flat, and uniform interfaces.

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Measuring and exploring symbolic money meanings
Authors: Rose Gregory M. , Orr Linda M.
Published: July 2007

This paper develops a scale to explore the symbolic meanings of money. Individual differences in the meanings and uses of money represent a fundamental issue in marketing, potentially influencing a wide variety of behaviors. Four dimensions were found based on a literature review and subsequent testing. Achievement and status, respectively, examine the extent that an individual perceives money as a marker of accomplishment or prestige. Worry examines the extent that a person feels anxious about money, whereas security examines the extent that an individual values money as a means of protection from an uncertain future. These dimensions are theoretically grounded, empirically tested, and potentially serve as a bridge between more general personal values and more specific consumer behaviors. © 2007 Wiley Periodicals, Inc.
Structural and spectral assignment of a new diterpenoid isolated from Ballota undulata and a complete 1H and 13C NMR data assignment for three other structurally related compounds
Authors: Hussein Ahmed A. , Jimeno María L. , Rodríguez Benjamín
Published: July 2007

The structure of 3β‐hydroxyballotinone, a new labdane diterpenoid isolated from Ballota undulata, has been established by NMR spectroscopic studies. In addition, complete and unambiguous assignments of the 1H and 13C NMR spectra of three other already known labdanes (ballotinone, ballonigrin and ballonigrinone) isolated from the same source have been achieved. The assignments are based on 2D shift‐correlated 1H1H COSY, 1H13C gHSQC [1J(C,H)] and 1H13C gHMBC [nJ(C,H) (n = 2 and 3)], and NOE experiments. Copyright © 2007 John Wiley & Sons, Ltd.
SPEED: single‐point evaluation of the evolution dimension
Authors: Kupče Eriks , Freeman Ray
Published: July 2007

Two‐dimensional NMR spectroscopy can be speeded up by orders of magnitude by severely restricting the number of sampling operations in the evolution dimension–we demonstrate that just a single measurement may suffice. The frequencies evolving in the indirect dimension (t1) are deduced from the amplitudes of the signals acquired in the direct dimension (t2). Prior measurements of the one‐dimensional spectra are required. Results are presented for the two‐dimensional 13C‐HSQC spectrum of 2‐ethylindanone recorded at a single fixed setting of the evolution time, demonstrating a speed advantage of 120. The method can be extended to multidimensional spectra, with correspondingly greater gains in speed. Copyright © 2007 John Wiley & Sons, Ltd.
Statistical analysis of 13C and 15N NMR chemical shifts from GIAO/B3LYP/6‐311 + + G** calculated absolute shieldings
Authors: Blanco Fernando , Alkorta Ibon , Elguero José
Published: July 2007

The 13C and 15N absolute shieldings of 28 compounds have been calculated at the GIAO/B3LYP/6‐311 + + G** level to complete a collection of data already published. This has allowed us to devise new equations relating δ and σ for these nuclei based on 461 points (13C) and 70(72) points (15N). Copyright © 2007 John Wiley & Sons, Ltd.
H(C)P and H(P)C triple‐resonance experiments at natural abundance employing long‐range couplings
Authors: Maloň Michal , Koshino Hiroyuki
Published: July 2007

Modified two‐dimensional (2D) triple‐resonance H(C)P and H(P)C experiments based on INEPT/HMQC and double‐INEPT schemes are applied to the study of organophosphorus compounds at natural abundances. The implementation of effective 1H13C gradient selection, additional purging pulsed field gradients, spinlock pulses, and improved phase cycling is demonstrated to allow weak correlation signals based on long‐range couplings to be readily observed. Through the combination of two heteronuclear long‐range coupling constants, nJCH and nJPC in H(C)P experiments or nJPH and nJPC in H(P)C experiments, protons can be correlated to a second heteronucleus through 4–7 chemical bonds. These experiments thus overcome the inherit limitations of classical 1H‐X HMBC experiments, which require a nonzero value of the heteronuclear coupling constant nJXH. Ultra‐broadband inversion composite pulses are successfully employed in the H(P)C INEPT/HMQC and H(P)C double‐INEPT pulse sequences to increase the utility of the experiments and the quality of obtained spectra. This work extends and completes a set of 2D phase‐sensitive triple‐resonance experiments applicable at natural abundances, and also offers insight into the methodology of triple‐resonance experiments and the application of pulsed field gradients. A one‐dimensional triple‐resonance experiment employing carbon detection is suggested for accurate determination of small nJPC. Copyright © 2007 John Wiley & Sons, Ltd.
Agroecosystem modeling and optimal economic decisions: Implications for sustainable agriculture
Authors: Bond Craig A. , Farzin Y. Hossein
Published: July 2007

We adapt a biogeochemical model of an agroecosystem to account for optimal economic behavior on the part of agricultural producers. Two institutional management regimes are considered: one in which a representative producer does not account for stock pollution caused by use of agricultural inputs, and one in which the externality is internalized. Comparative statics of the steady state of the former problem are analyzed in order to gain insight into the effects of potential policy and technological changes. Results show that a more realistic ecosystem component that includes nutrient cycling can qualitatively change optimal management practices relative to a one‐state representation, potentially rendering systems ‘unsustainable’ under some criteria and leading to policy instruments that exacerbate, rather than mitigate, external damages or the resource base. Moreover, the qualitative effect of changes in model parameters are not necessarily uniform across different agricultural systems, implying that a prescription for the so‐called ‘sustainable’ management under one system may have unintended consequences under another system. Copyright © 2007 John Wiley & Sons, Ltd.
A Phase 1 and pharmacokinetic clinical trial of paclitaxel for the treatment of refractory leukemia in children: A Children's Oncology Group study
Authors: Horton Terzah M. , Ames Matthew M. , Reid Joel M. , Krailo Mark D. , Pendergrass Thomas , Mosher Revonda , Reaman Gregory H. , Seibel Nita L.
Published: August 2007

Background

This report summarizes a phase 1 study conducted by the Children's Cancer Group (CCG) to determine the maximum tolerated dose (MTD), dose‐limiting toxicities (DLTs), pharmacokinetics, and anti‐leukemia activity of paclitaxel in children with advanced stage leukemias.

Procedure

This study examined two dose escalation schedules of intravenous paclitaxel. Doses ranged from 250 to 500 mg/m2 every 21 days in schedule A and 105 to 200 mg/m2 weekly × 3 every 28 days in schedule B. Serial plasma samples for pharmacokinetic studies were obtained after the first paclitaxel dose.

Results

Sixty‐three patients (median 10 years) with refractory or relapsed leukemia (ALL) (n = 39), acute myeloid leukemia (AML) (n = 19), biphenotypic (n = 4), and JCML (n = 1)) were enrolled. The DLTs in schedule A were grade 4 hypertension and hyperbilirubinemia with an MTD of 430 mg/m2 every 21 days. The DLTs in schedule B were coagulopathy, hyperkalemia, hyperbilirubinemia, elevated SGOT (n = 1, 125 mg/m2), peripheral neuropathy (n = 1, 200 mg/m2), and typhlitis (n = 1, 200 mg/m2) with an MTD of 182 mg/m2 weekly × 3 every 28 days. Among 54 evaluable patients, there was one complete response (CR), three partial responses (PR), and five patients with stable disease (SD). The mean terminal elimination half‐life was 9.5 ± 3.4 hr and the mean plasma clearance was 23 ± 11 L/hr/m2.

Conclusions

Paclitaxel was tolerated at 430 mg/m2 every 21 days and at 182 mg/m2/dose weekly × 3 every 28 days in pediatric patients. The objective response rate across all dose levels and schedules was <10%. Pediatr Blood Cancer 2008;50:788–792. © 2007 Wiley‐Liss, Inc.
Sibutramine usage in New Zealand: an analysis of prescription data by the Intensive Medicines Monitoring Programme
Authors: Hill Geraldine R. , Ashton Janelle , Harrison‐Woolrych Mira
Published: July 2007

Purpose

To describe patterns of sibutramine usage in New Zealand during the first 3 years of marketing using data acquired during post‐marketing safety surveillance.

Methods

Demographic and prescription data were examined from a nationwide cohort of 17 298 patients prescribed sibutramine between 1 February 2001 and 31 March 2004. Outcome measures were age and sex distribution of the cohort; period prevalence of sibutramine usage for each ethnic group; duration of treatment and reasons for cessation of therapy. Limited BMI data were also examined.

Results

About 0.5% of the NZ population were prescribed sibutramine in the period studied. Overwhelmingly, the highest users of sibutramine were NZ European women aged 30–59 years. Maori and Pacific Peoples were under‐represented in the cohort, despite the higher prevalence of obesity among these populations. Sibutramine usage was predominantly short‐term: 59% of the cohort used sibutramine for 90 days or less, half of whom used it for only 1 month.

Conclusions

There has been extensive use of sibutramine in New Zealand. Sibutramine has been relatively under‐utilised by Maori and Pacific ethnic groups, compared to New Zealand Europeans, despite their higher prevalence of obesity. A number of factors may have contributed to the predominantly short‐term use of this medicine, including the cost of the medicine to the consumer, weight loss not meeting expectations and adverse effects of the medicine. Copyright © 2007 John Wiley & Sons, Ltd.
Protein homology detection and fold inference through multiple alignment entropy profiles
Authors: Sánchez‐Flores Alejandro , Pérez‐Rueda Ernesto , Segovia Lorenzo
Published: August 2007

Homology detection and protein structure prediction are central themes in bioinformatics. Establishment of relationship between protein sequences or prediction of their structure by sequence comparison methods finds limitations when there is low sequence similarity. Recent works demonstrate that the use of profiles improves homology detection and protein structure prediction. Profiles can be inferred from protein multiple alignments using different approaches. The “Conservatism‐of‐Conservatism” is an effective profile analysis method to identify structural features between proteins having the same fold but no detectable sequence similarity. The information obtained from protein multiple alignments varies according to the amino acid classification employed to calculate the profile. In this work, we calculated entropy profiles from PSI‐BLAST‐derived multiple alignments and used different amino acid classifications summarizing almost 500 different attributes. These entropy profiles were converted into pseudocodes which were compared using the FASTA program with an ad‐hoc matrix. We tested the performance of our method to identify relationships between proteins with similar fold using a nonredundant subset of sequences having less than 40% of identity. We then compared our results using Coverage Versus Error per query curves, to those obtained by methods like PSI‐BLAST, COMPASS and HHSEARCH. Our method, named HIP (Homology Identification with Profiles) presented higher accuracy detecting relationships between proteins with the same fold. The use of different amino acid classifications reflecting a large number of amino acid attributes, improved the recognition of distantly related folds. We propose the use of pseudocodes representing profile information as a fast and powerful tool for homology detection, fold assignment and analysis of evolutionary information enclosed in protein profiles. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Implicit flexibility in protein docking: Cross‐docking and local refinement
Authors: Król Marcin , Chaleil Raphael A. G. , Tournier Alexander L. , Bates Paul A.
Published: August 2007

In previous CAPRI rounds (3–5) we showed that using MD‐generated ensembles, as inputs for a rigid‐body docking algorithm, increased our success rate, especially for targets exhibiting substantial amounts of induced fit. In recent rounds (6–11), our cross‐docking was followed by a short MD‐based local refinement for the subset of solutions with the lowest interaction energies after minimization. The above approach showed promising results for target 20, where we were able to recover 30% of native contacts for one of our submitted models. Further tests, performed a posteriori, revealed that cross‐docking approach produces more near‐native (NN) solutions but only for targets with large conformational changes upon binding. However, at the time of the blind docking experiment, these improved solutions were not chosen for the subsequent refinement, as their interaction energies after minimization ranked poorly compared with other solutions. This indicates deficiencies in the present scoring schemes that are based on interaction energies of minimized structures. Refinement MD simulations substantially increase the fraction of native contacts for NN docked solutions, but generally worsen interface and ligand RMSD. Further analysis shows that although MD simulations are able to improve sidechain packing across the interface, which results in an increased fraction of native contacts, they are not capable of improving interface and ligand backbone RMSD for NN structures beyond 1.5 and 3.5 Å, respectively, even if explicit solvent is used. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Acaricide resistance and synergism between permethrin and amitraz against susceptible and resistant strains of Boophilus microplus (Acari: Ixodidae)
Authors: Li Andrew Y , Chen Andrew C , Miller Robert J , Davey Ronald B , George John E
Published: July 2007

The control of the southern cattle tick, Boophilus microplus (Canestrini), in Mexico and many other countries relies on chemical acaricides. Boophilus microplus has developed resistance to all major classes of acaricides in recent years. To gain a better understanding of the resistance and to develop resistance management strategies that benefit both Mexican ranchers and USDA's cattle fever tick eradication program (CFTEP), the authors used larval bioassay techniques to determine levels of resistance to permethrin and amitraz and then evaluated synergism between these two acaricides in one susceptible laboratory tick strain and four resistant strains originating from Mexico and Brazil. To examine mechanisms of resistance to permethrin in these strains, the frequency of a mutated sodium channel gene was determined using a PCR assay. The tick strains from Mexico and Brazil demonstrated 49.4‐ to over 672.2‐fold resistance to permethrin, and up to 94.5‐fold resistance to amitraz. While the San Roman strain from Mexico was the most permethrin‐resistant strain, the Santa Luiza strain from Brazil was the most amitraz‐resistant strain. A significant correlation was found between the permethrin resistance ratio and the allelic frequency of the sodium channel mutation. Significant synergism between permethrin and amitraz was found when one acaricide was tested in the presence of another. Synergism ratios ranged from 1.5 to 54.9 when amitraz was tested as a synergist for permethrin. Similar synergism ratios were obtained when permethrin was tested as a synergist for amitraz. Permethrin caused virtually no mortality in the San Roman strain, even at the highest concentration (3294 µg cm−2). Adding amitraz (11.0 µg cm−2) to permethrin led to a dramatic increase in larval mortality, even at very low concentrations of permethrin. Copyright © 2007 Society of Chemical Industry
Molecular characterisation of resistance to ALS‐inhibiting herbicides in Hordeum leporinum biotypes
Authors: Yu Qin , Nelson Jared K , Zheng Ming Q , Jackson Michael , Powles Stephen B
Published: July 2007

BACKGROUND: The acetolactate synthase (ALS)‐inhibiting herbicide sulfosulfuron is registered in Australia for the selective control of Hordeum leporinum Link. in wheat crops. This herbicide failed to control H. leporinum on two farms in Western Australia on its first use. This study aimed to determine the level of resistance of three H. leporinum biotypes, identify the biochemical and molecular basis and develop molecular markers for diagnostic analysis of the resistance.

RESULTS: Dose–response studies revealed very high level (>340‐fold) resistance to the sulfonylurea herbicides sulfosulfuron and sulfometuron. In vitro ALS assays revealed that resistance was due to reduced sensitivity of the ALS enzyme to herbicide inhibition. This altered ALS sensitivity in the resistant biotypes was found to be due to a mutation in the ALS gene resulting in amino acid proline to serine substitution at position 197. In addition, two‐ to threefold higher ALS activities were consistently found in the resistant biotypes, compared with the known susceptible biotype. Two cleaved amplified polymorphic sequence (CAPS) markers were developed for diagnostic testing of the resistant populations.

CONCLUSION: This study established the first documented case of evolved ALS inhibitor resistance in H. leporinum and revealed that the molecular basis of resistance is due to a Pro to Ser mutation in the ALS gene. Copyright © 2007 Society of Chemical Industry
Effect of snack eating on salivary α‐amylase, a novel stress marker
Authors: Toda Masahiro , Morimoto Kanehisa
Published: July 2007

The aim of this study is to investigate the effect of snack eating on salivary α‐amylase (sAA) as compared with salivary cortisol. From 15 healthy males, saliva samples were collected every 30min from 14:00 to 18:00. Immediately after the sampling at 15:00, seven subjects (snack‐eating group) ate a snack. The sAA and cortisol levels were determined with commercial kits. In the snack‐eating group, there was a significant increase in both the levels of sAA and cortisol after snack eating at 15:30. Even higher salivary cortisol levels were detected at 16:00. In the control group, no significant changes were detected. These findings suggest that both the levels of sAA and salivary cortisol are affected by snack eating and that, before saliva sampling for stress measurement, a fasting period of about 90min is appropriate. Copyright © 2007 John Wiley & Sons, Ltd.
Burnout and self‐employment: a cross‐cultural empirical study
Authors: Jamal Muhammad
Published: July 2007

This study examined the differences between full‐time self‐employed and organizationally employed individuals in Canada (n = 248) and Pakistan (n = 306) in terms of overall burnout and its three dimensions (emotional exhaustion, depersonalization and lack of accomplishment), turnover intentions and non‐work satisfaction. Data were collected by means of a structured questionnaire from Canadian employees in Montreal and Pakistani employees in Lahore. One‐way analysis of variance and multivariate analysis of variance were used to analyse the data. The self‐employed reported significantly higher overall burnout, emotional exhaustion, lack of accomplishment, non‐work satisfaction and turnover intention than the organizationally employed in both countries. No significant differences were found between self‐employed and organizationally employed in terms of depersonalization in both countries. Results are discussed in light of previous empirical evidence on self‐employment and the quality of work and non‐work life from cross‐cultural perspectives. Copyright © 2007 John Wiley & Sons, Ltd.