bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrawideband monocycle pulse generator with dual resistive loaded shunt stubs
Authors: Ma Tzyh‐Ghuang , Wu Chin‐Jay , Cheng Po‐Kai , Chou Chin‐Feng
Published: December 2006

An ultrawideband (UWB) monocycle pulse generator with dual resistive loaded shunt stubs is present in this article. The proposed pulse generator consists of a step recovery diode (SRD), a Schottky diode, a pair of resistive loaded stubs, and a pair of short‐circuited stubs. By introducing an additional resistive loaded stub between the SRD and the Schottky diode, the ringing tail of the impulse waveform can be substantially suppressed and the resultant monocycle pulse is well‐behaved with very low ringing level. The measurement result demonstrates a monocycle pulse with peak‐to‐peak amplitude of 550 mV, pulsewidth of 320 ps, ringing level of as low as −22 dB, and good pulse symmetry. This pulse generator is suitable for various UWB applications. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 459–462, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22145
Dielectric resonator antenna: Operation of the magnetodielectric composites Cr0.75Fe1.25O3(CRFO)/Fe0.5Cu0.75Ti0.75O3(FCTO)
Authors: Rocha H. H. B. , Freire F. N. A. , Costa R. C. S. , Sohn R. S. T. M. , Orjubin G. , Junqueira C. , Cordaro T. , Sombra A. S. B.
Published: December 2006

The probe‐feed cylindrical dielectric resonator antennas (DRA) based on a new magnetodielectric composites Cr0.75Fe1.25O3(CRFO)/Fe0.5Cu0.75Ti0.75O3(FCTO) are investigated. The experimental and theoretical characteristics of the antenna like return loss, bandwidth, input impedance, and radiation patterns are in good agreement. Numerical validation is done, tacking into account the air gaps between the dielectric resonator and the metallic conductors. Frequency response bandwidth in the range of 6.6–11.8% was obtained for frequency operation around 4 GHz. The CRFO‐FCTO present a dielectric constant in the range of 8–13 with loss around 10−3. To summarize, the performance of a cylindrical DRA based in a new matrix CRFO/FCTO was examined. These measurements confirm the potential use of such materials for small DRA. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 409–413, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22160
Microwave holography measurement and adjustment of 25‐m radio telescope of Shanghai
Authors: Yu Hong
Published: December 2006

In an attempt to measure and correct the surface profile of the Sheshan 25‐m radio telescope, the author carried out a phase coherent holographic experiment at 12.26 GHz with a geostationary communication satellite SINO‐1 in the far field. To improve the spatial resolution, the author took the drift of the communication satellite into consideration. For the backend, a digital cross correlator was used to measure the complex beam pattern of the antenna under test. According to the data collected in the experiments, the holography software can give the energy distribution map, error map, and a suggested adjustment for every junction of the panels, after four iterations of measurement and adjustment in a week, the surface accuracy of the antenna is improved from 0.948 mm to better than 0.5 mm. The experiment shows that the microwave holography is much faster and more convenient than traditional method. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 467–470, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22171
QSPR ofn‐Octanol/Water Partition Coefficient of Nonionic Organic Compounds Using Extended Topochemical Atom (ETA) Indices
Authors: Roy Kunal , Sanyal Indrani , Ghosh Gopinath
Published: December 2006

Consideringn‐octanol/water partition coefficient as an important chemical property in modeling the fate and persistence of chemicals, recently introduced Extended Topochemical Atom (ETA) indices have been used to modeln‐octanol/water partition coefficient data of 122 nonionic organic compounds which are highly persistent in the environment and reported to bioconcentrate considerably in lipid tissues. In deriving the models, principal component Factor Analysis (FA) followed by Multiple Linear Regression (MLR), stepwise regression, Partial Least Squares (PLS), and Principal Component Regression Analyses (PCRA) were applied as the statistical tools. The model development process was repeated with non‐ETA (topological and physicochemical) descriptors and a combination set comprising both the ETA and non‐ETA descriptors. The models with ETA indices suggested negative contributions of groups capable of hydrogen bonding and/or polar interactions and positive contributions of volume and degree of halogen substitution to the partition coefficient. Finally, we discuss validation of QSPR models by dividing the dataset into training and test sets based on different strategies,e.g., random division, sorted log Kowdata andK‐means clusters for the factor scores of the original variable (ETA) matrix without the response property values. The ETA (FA‐MLR and stepwise regression) models were also applied on a purely external dataset (n=35) and acceptable predictiver2values (0.582 and 0.651 respectively) were obtained. The results suggest that ETA parameters are sufficiently rich in chemical information to encode the structural features contributing to then‐octanol/water partition coefficient of nonionic organic compounds and thus these merit further assessment to explore their potential in QSAR/QSPR/QSTR modeling.
Design and stability analysis of cooperative receding‐horizon control of linear discrete‐time agents
Authors: Franco Elisa , Parisini Thomas , Polycarpou Marios M.
Published: December 2006

This paper considers the problem of designing cooperative control algorithms for a team of distributed agents operating towards achieving a global performance objective. Each agent is assumed to evolve according to certain discrete‐time, linear dynamics and to exchange delayed state information with a subset of neighbouring or cooperating agents. The control design formulation is based on the definition of a finite‐horizon cost function that includes both the regulation and cooperation objectives. The cooperative control problem is formulated in a receding‐horizon framework, where the control law can be explicitly broken up in two components: one due to feedback from the local state variables and the other based on delayed information gathered from cooperating neighbouring agents. The stability and performance analysis of the overall system is carried out and simulation results are used to illustrate the effectiveness of the proposed control scheme. Copyright © 2006 John Wiley & Sons, Ltd.
Relative risk and acceleration in lung cancer
Authors: Berry Geoffrey
Published: December 2006

For a substance that increases the relative risk of disease, it does not necessarily follow that the proportion of cases due to exposure to the substance is the same as the attributable fraction in the exposed. An alternative explanation is that the substance has accelerated the occurrence of disease and, therefore, played a role in all cases. When the incidence of disease with time follows the Weibull distribution, it is well known that the proportional hazards model and the accelerated failure time model are equivalent. The purpose of this paper is to provide a numerical illustration of the relationship between the relative risk and the acceleration time of occurrence of cases. A Weibull distribution is a good approximation for lung cancer death rates up to the age of 80 years. The numerical relationship between the relative risk and the time by which cases are accelerated is given for lung cancer deaths occurring at ages of 40–75 years with relative risks of 1.01–3. As an example, for a death due to lung cancer at age 60 years in a smoker, relative risks of 2 and 1.1 due to occupational exposure to a substance correspond to accelerations of 5.2 years and 8 months, respectively. Copyright © 2006 John Wiley & Sons, Ltd.
Learning from students, inquiry into practice, and participation in professional communities: Beginning teachers' uneven progress toward equitable science teaching
Authors: Bianchini Julie A. , Cavazos Lynnette M.
Published: December 2006

In this research project, we investigated two beginning secondary science teachers' efforts to learn to teach science in ways that build from and celebrate the ethnic, gender, linguistic, and academic diversity of their students. To do so, we followed Troy and Brian from their preservice teacher education experiences through their first year of teaching 8th grade physical science at local junior high schools. We also conducted a follow‐up observation and interview with each participant after he had moved past the beginning stage of survival in the teaching profession—once in his fourth year of public school science teaching. Through qualitative analysis of interviews, classroom observations, and teachers' written work, we identified patterns and explored commonalities and differences in Troy and Brian's views and practices tied to equity over time. In particular, we examined successes and challenges they encountered in learning to teach science for all (a) from their students, (b) from inquiry into practice, and (c) from participation in professional communities. In our implications, we suggest ways teacher educators and induction professionals can better support beginning teachers in learning to teach science to all students. In particular, we highlight the central roles both individual colleagues and collective school cultures play in aiding or impeding beginning teachers' efforts to learn from students, from practice, and from professional communities. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 44: 586–612, 2007.
Nuss Procedure: Pediatric Surgical Solution for Adults with Pectus Excavatum
Authors: Aronson Daniel C. , Bosgraaf Remko P. , van der Horst Chantal , Ekkelkamp Seine
Published: December 2006

Introduction

The aim of the study was to compare results of the Nuss procedure in adults and children.

Methods

The data were collected prospectively. Antibiotic prophylaxis was used in all patients. Differences were tested statistically.

Results

A total of 35 adults (28 men; male/female ratio 4:1) with a median age of 23 years (range 18 years to 47 years 1 month) were included in the study. A previous Welch operation had been performed in one (3%). The median operating time was 65 minutes (range 45–105 minutes). Two bars were inserted in one patient, and stabilizers were used in all. Pneumothorax occurred in 9 (26%), wound abscess in 3 (9%), and bar slips in 5 (14%). The median hospital stay was 7 days (range 4–10 days). Bars were removed in 14 (40%) patients without complications. Follow‐up occurred 6 and 12 months after bar removed, at which times no recurrence of the pectus and no sternal protrusions were seen. In the other part of the study, 141 children and adolescents (105 boys; male/female ratio 3:1) with a median age of 13 years (range 4 years 11 months to 17 years 8 months) were included. A previous Welch operation had been performed in five (4%). Two bars were inserted in four, and stabilizers were used in 100 (71%). The median operating time was 65 minutes (40–185 minutes). Pneumothorax occurred in 33 (24%), wound abscess in 1 (0.7%), and bar slips in 18 (13%). The median hospital stay was 7 days (range 5–18 days). Bars were removed in 77 (55%) without complications. Follow‐up occurred 6 and 12 months after bar removed, and the last follow‐up was eventually planned at the end of growth (age 18). The pectus recurred in one patient with Marfan syndrome, and sternal protrusion occurred in one. Differences between groups were as follows: a significantly higher proportion of adult patients were treated with stabilizers (P < 0.001), and there were significantly more wound abscesses in adults (P < 0.001).

Conclusions

The Nuss procedure is as effective for correcting pectus excavatum in adults as it is in children. However, in adults the bars tended to be less stable, and wound abscesses occurred more frequently.
Economic incentives, social norms, and the crisis of fisheries
Authors: Jackson Jeremy B. C.
Published: December 2006

This year's Kyoto prize signals the long overdue recognition of the fundamental interdependence of economic and ecologic systems for the protection and maintenance of ecosystem services and human well‐being. Levin (2006) and Vincent (2007) point to several of the more important ways that interdisciplinary approaches will be essential to the better quantification and understanding of the economic contributions of ecosystem services, but they differ fundamentally in their relative faith in the evolution of new social norms versus economic incentives backed up by sanctions to achieve the necessary cooperation for environmental protection. In the case of marine fisheries, social norms have proven highly effective on small spatial scales but have not taken root in the face of increasingly global markets and free trade.
A trophic cascade in a macrophyte‐based food web at the land–water ecotone
Authors: Schlacher Thomas A. , Cronin Greg
Published: December 2006

Trophic cascades may purportedly be more common in aquatic than terrestrial food webs, but herbivory on freshwater vascular plants has historically been considered low. Water lilies are an exception, suffering severe grazing damage by leaf beetles. To test whether a central prediction of cascade models—that predator effects propagate downwards to plants—operates in a macrophyte‐based food web, we experimentally manipulated predation pressure on a key herbivore of water lilies in the littoral zone of a lake in Michigan, USA. Field experiments comprised combinations of caging treatments to alter the number of predators (larvae of the ladybird beetleColeomegilla maculata) that hunt the grazers of the macrophytes (larvae of the leaf beetlesGalerucella nymphaeae) on the leaves of the water lilyNuphar advena. Predatory larvae of the ladybird beetles significantly reduced grazing damage to water‐lily leaves by 35–43%. The predators reduced plant damage chiefly via density‐mediated effects, when lower densities of grazers translated to significant declines in plant damage. Plant damage caused by the surviving herbivores was less than predicted from individual grazing rates under predator‐free conditions. This suggests that trait‐mediated effects may possibly also operate in this cascade. The observed strong effect of predators on a non‐adjacent trophic level concurs with an essential component of the trophic cascade model, and the cascade occurred at the ecotone between aquatic and terrestrial habitats:Nupharis an aquatic macrophyte with emergent and floating leaves, whereas both beetle species are semi‐terrestrial and use the dry, emergent and floating leaves of the water lily as habitat. Also, the cascade is underpinned by freshwater macrophytes—a group for which trophic processes have often been underappreciated in the past.
Correlations of relative rate constants for sulfonation of alkylbenzenes with molecular structure
Authors: Roberts David W. , Ward Robert S. , Hughes Paul J.
Published: December 2006

Relative sulfonation rates of a series of linear alkylbenzenes are correlated with carbon numbers of the linear branches from which the alkyl groups are constituted. The trends are interpreted in terms of a composite steric parameter which reflects the degrees of freedom lost in forming the transition state. The results lend support to the argument that the entropy of activation is the main factor determining the relative reactivities of the different homologs and isomers in this reaction.
Synergistic solubilization of decafluorobiphenyl by micelles of fluorocarbon surfactants
Authors: Asakawa Tsuyoshi , Kitaguchi Takashi , Miyagishi Shigeyoshi
Published: December 2006

Solubilization of decafluorobiphenyl (FBIP) by surfactants in aqueous solution was examined to investigate the properties of micelles composed of surfactants having a per‐fluorocarbon chain. Fluorocarbon surfactants solubilize FBIP better than hydrocarbon surfactants. Significant solubilization by fluorocarbon surfactants was observed upon addition of salt. Highly synergistic solubilization of FBIP using surfactant mixtures was also observed for fluorocarbon and hydrocarbon surfactants in the presence of salt. The high solubilization ability of surfactants can be attributed to micelle growth. A simple geometrical consideration of molecular packing in micelles revealed that the characteristic micelle is composed of bulky fluorocarbon chains. The solubilization behavior accompanied by micelle growth would be closely associated with a change in interfacial contact area between the micelle core and bulk water. The behavior of fluorescence intensity of micelle‐solubilized FBIP also indicated a change in micropolarity of fluorocarbon micelles accompanied by micelle growth.
Safety to human skin of cocamidopropyl betaine: A mild surfactant for personal‐care products
Authors: Hunter J. Edward , Fowler Joseph F.
Published: December 2006

Cocamidopropyl betaine (CAPB) is a mild surfactant used in shampoos, conditioners, body washes, and other personal‐care products. Several recently published case reports have suggested that CAPB may be a skin sensitizer. A 6‐wk product‐use study was conducted to determine whether subjects with previous positive patch tests to CAPB could use personal‐care products (prototype hair shampoo, liquid handsoap, and body wash) with this surfactant without problems. Post‐study patch testing suggested that amidoamine, a material used in the synthesis of CAPB and a contaminant of CAPB preparations, is a likely sensitizer. However, patch testing did not rule out the possibility that CAPB itself may be an allergen to a small number of presensitized individuals. It is recommended that CAPB with minimal levels of contamination be used for the formulation of personal‐care products.
Molecular characterization of three peroxisome proliferator‐activated receptors from the sea bass (Dicentrarchus labrax)
Authors: Boukouvala Evridiki , Antonopoulou Efthimia , Favre‐Krey Laurence , Diez Amalia , Bautista José M. , Leaver Michael J. , Tocher Douglas R. , Krey Grigorios
Published: December 2006

Peroxisome proliferator‐activated receptors (PPAR) are nuclear hormone receptors that control the expression of genes involved in lipid homeostasis in mammals. We searched for PPAR in sea bass, a marine fish of particular interest to aquaculture, after hypothesizing that the physiological and molecular processes that regulate lipid metabolism in fish are similar to those in mammals. Here, we report the identification of complementary DNA and corresponding genomic sequences that encode three distinct PPAR from sea bass. The sea bass PPAR are the structural homologs of the mammalian PPARα, β/δ and γ isotypes. As revealed by RNase protection, the tissue expression profile of the fish PPAR appears to be very similar to that of the mammalian PPAR homologs. Thus, PPARα is mainly expressed in the liver, PPARγ in adipose tissue, and PPARβ in all tissues tested, with its highest levels in the liver, where it is also the dominant isotype expressed. Like mammalian PPAR, the sea bass isotypes recognize and bind to PPAR response elements of both mammalian and piscine origin, as heterodimers with the 9‐cis retinoic acid receptor. Through the coactivator‐dependent receptor ligand assay, we also demonstrated that natural FA and synthetic hypolipidemic compounds can act as ligands of the sea bass PPARα and β isotypes. This suggests that the sea bass PPAR act through similar mechanisms and perform the same critical lipid metabolism functions as mammalian PPAR.
Elastic anisotropy in hcp metals at high pressure and the sound wave anisotropy of the Earth's inner core
Authors: Antonangeli Daniele , Merkel Sébastien , Farber Daniel L.
Published: December 2006

We compare the elastic anisotropy in hcp metals at high pressure obtained by radial diffraction measurements with those determined by other experiments and calculations. Our analysis demonstrates that in non‐hydrostatically compressed hcp metals the assumption of a single uniform macroscopic stress applied to all grains in the polycrystal for the inversion of the lattice strain equations is violated due to plastic deformation. In addition, the derived apparent moduli and elastic anisotropy differ significantly from those derived from single crystals. We propose that for cobalt, rhenium and iron, the elastic anisotropy in the meridian plane is best described by a sigmoidal shape for the longitudinal velocity, with the fastest direction along the c‐axis. Based on these results, we suggest that preferential alignment of the c‐axis of iron crystallites along the Earth's rotation axis is the most plausible explanation for the observed P‐wave travel time anomalies in the inner core.
Role of p38 mitogen‐activated protein kinase in cardiac remodelling
Authors: Frantz S , Behr T , Hu K , Fraccarollo D , Strotmann J , Goldberg E , Ertl G , Angermann C E , Bauersachs J
Published: December 2006

Background and purpose:

Mitogen‐activated protein kinases (MAPK) are centrally involved in several mechanisms important for heart failure such as apoptosis, activation of inflammatory responses and cell proliferation. We therefore evaluated the effect of the selective p38 MAPK inhibitor SB 239063 on progression of left ventricular remodelling after myocardial infarction (MI) in rats.

Experimental approach:

Rats were treated for 9 weeks with placebo or SB 239063 by gavage (15mg kg‐1) twice daily starting 7 days after ligation of the left anterior descending artery. Serial transthoracic echocardiography was performed at days 7, 36 and 70.

Key results:

Over the 9 weeks, mortality was not different between the groups. On echocardiography, animals after myocardial infarction exhibited significant left ventricular dilatation as expected (week 10, end‐systolic diameter, placebo sham 5.21± 0.34 vs. placebo MI 8.44± 0.57 mm). However, there was no difference between placebo and SB 239063‐treated rats (week 10, end‐systolic diameter, SB MI 7.76± 0.74mm, not significantly different from placebo MI). Haemodynamics changed accordingly. Moreover, SB 239063 had no effect on left ventricular hypertrophy. Treatment with SB 239063 significantly reduced cytokine expression of tumour necrosis factor and interleukin‐1β after myocardial infarction. However, collagen content was not influenced by the treatment.

Conclusion:

Despite a reduction of inflammation, treatment with the p38 inhibitor SB 239063 does not affect cardiac remodelling and cardiac function when treatment is started 7 days after myocardial infarction.

British Journal of Pharmacology(2007)150, 130–135. doi:10.1038/sj.bjp.0706963
Protease‐activated receptor‐4: a novel mechanism of inflammatory pain modulation
Authors: Asfaha S , Cenac N , Houle S , Altier C , Papez M D , Nguyen C , Steinhoff M , Chapman K , Zamponi G W , Vergnolle N
Published: December 2006

Background and purpose:

Protease‐activated receptor‐4 (PAR4), the most recently discovered member of the PARs family, is activated by thrombin, trypsin and cathepsin G, but can also be selectively activated by small synthetic peptides (PAR4‐activating peptide, PAR4‐AP). PAR4is considered a potent mediator of platelet activation and inflammation. As both PAR1and PAR2have been implicated in the modulation of nociceptive mechanisms, we investigated the expression of PAR4in sensory neurons and the effects of its selective activation on nociception.

Experimental approach and key results:

We demonstrated the expression of PAR4in sensory neurons isolated from rat dorsal root ganglia by reverse transcription‐polymerase chain reaction and immunofluorescence. We found that PAR4colocalized with calcitonin gene‐related peptide and substance P. We also showed that a selective PAR4‐AP was able to inhibit calcium mobilization evoked by KCl and capsaicin in rat sensory neurons. Moreover, the intraplantar injection of a PAR4‐AP significantly increased nociceptive threshold in response to thermal and mechanical noxious stimuli, while a PAR4inactive control peptide had no effect. The anti‐nociceptive effects of the PAR4‐AP were dose‐dependent and occurred at doses below the threshold needed to cause inflammation. Finally, co‐injection of the PAR4‐AP with carrageenan significantly reduced the carrageenan‐induced inflammatory hyperalgesia and allodynia, but had no effect on inflammatory parameters such as oedema and granulocyte infiltration.

Conclusions and implications:

Taken together, these results identified PAR4as a novel potential endogenous analgesic factor, which can modulate nociceptive responses in normal and inflammatory conditions.

British Journal of Pharmacology(2007)150, 176–185. doi:10.1038/sj.bjp.0706975
Characterization of kinin receptors in human cultured detrusor smooth muscle cells
Authors: Bellucci F , Cucchi P , Santicioli P , Lazzeri M , Turini D , Meini S
Published: December 2006

Background and purpose:

Kinins have an important role in inflammatory cystitis and in animal pathophysiological models, by acting on epithelium, fibroblasts, sensory innervation and smooth muscle. The aim of this study was to characterize the receptors responsible for direct motor responses induced by kinins on human detrusor.

Experimental approach:

Human detrusor cells from biopsies were isolated and mantained in culture. B1and B2kinin receptors were characterized by means of radioligand and functional experiments (PI accumulation and PGE2release).

Key results:

[3H]‐[desArg9]‐Lys‐BK and [3H]‐BK saturation studies indicated receptor density (Bmax) andKdvalues of 19 or 113 fmol mg−1, and 0.16 or 0.11 nM for the B1or B2receptors, respectively. Inhibition binding studies indicated the selectivity of the B1receptor antagonist [desArg9Leu8]‐Lys‐BK and of the B2receptor antagonists Icatibant and MEN16132. [DesArg9]‐Lys‐BK and BK induced PI accumulation with an EC50of 1.6 and 1.4 nM and different maximal responses (Emaxof [desArg9]‐Lys‐BK was 10% of BK). BK also induced prostaglandin E2release (EC502.3 nM), whereas no response was detected with the B1receptor agonist. The incubation of detrusor smooth muscle cells with interleukin 1β (IL‐1β) or tumour necrosis factor‐α(TNF‐α) (10 ng ml−1) induced a time‐dependent increase in radioligand‐specific binding, which was greater for the B1than for the B2receptor.

Conclusions and Implications:

Human detrusor smooth muscle cells in culture retain kinin receptors, and represent a suitable model to investigate the mechanisms and changes that occur under chronic inflammatory conditions.

British Journal of Pharmacology(2007)150, 192–199. doi:10.1038/sj.bjp.0706976
The function of α‐ and β‐adrenoceptors of the saphenous artery in caveolin‐1 knockout and wild‐type mice
Authors: Neidhold S , Eichhorn B , Kasper M , Ravens U , Kaumann A J
Published: December 2006

Background and purpose:

Adrenoceptors can associate with cardiac caveolae. To investigate the function of vascular caveolae, adrenoceptor‐mediated effects were compared in the saphenous artery of caveolin‐1 knockout (cav‐1KO) and wild‐type (WT) mice.

Experimental approach:

Electronmicroscopy was used to detect caveolae. Real‐Time quantitative PCR was used for adrenoceptor subtypes. Catecholamine‐evoked contractions and relaxations were studied in arterial segments.

Key results:

Caveolae were found in arterial smooth muscle from WT but not from cav‐1KO mice. Arterial mRNA levels for the adrenoceptors α1A, α1B, α1D, β1, β2and β3were similar in cav‐1KO and WT. (‐)‐Noradrenaline contracted cav‐1KO (‐log EC50M=7.1) and WT (‐log EC50M=7.3) arteries through prazosin‐sensitive receptors. Maximum (‐)‐noradrenaline‐evoked contractions were greater in cav‐1KO than WT arteries. (‐)‐Isoprenaline relaxed WT arteries (‐log EC50M=7.3) more potently than cav‐1KO arteries (‐log EC50M=6.8); the effects were antagonized partially and similarly by the β2‐selective antagonist ICI118551 (50 nM). The (‐)‐isoprenaline‐evoked relaxation was partially antagonized by the β1‐adrenoceptor‐selective antagonist CGP20712 (300 nM) in WT but not cav‐1KO arteries. The β3‐adrenoceptor‐selective antagonist L748337 (100nM) partially antagonized the relaxant effects of (‐)‐isoprenaline in cav‐1KO but not in WT arteries. BRL37344 partially relaxed arteries through β3‐adrenoceptors in cav‐1KO but not WT. The relaxant effects of BRL37344 were decreased by the NO synthase inhibitor ΩL‐nitroarginine.

Conclusions and implications:

The function of arterial α1‐ and β2‐adrenoceptors is similar in cav‐1KO and WT mice. β1‐adrenoceptor‐mediated relaxation in WT is lost in cav‐1KO and replaced by the appearance of β3‐adrenoceptors.

British Journal of Pharmacology(2007)150, 261–270. doi:10.1038/sj.bjp.0706980
Antagonist, partial agonist and antiproliferative actions of B‐9870 (CU201) as a function of the expression and density of the bradykinin B1and B2receptors
Authors: Morissette G , Houle S , Gera L , Stewart J M , Marceau F
Published: December 2006

Background and purpose:

A bradykinin (BK) B2receptor (B2R) antagonist, B‐9870 (CU201), has been proposed to behave as a ‘biased agonist’ at B2Rs and to exert anti‐neoplasic effects. It was unclear whether these effects were determined by the activation of B2Rs by the drug. B‐9870 was evaluated for antagonism or stimulation of several responses mediated by the rabbit B2R or B1receptor (B1R); its anti‐proliferative activity was also characterized.

Experimental approach and key results:

B‐9870 was an insurmountable B2R antagonist in the rabbit jugular vein contractility assay, but a partial agonist in HEK 293 cells expressing the rabbit B2R or a green fluorescent protein (GFP) conjugate of the latter (ERK1/2 phosphorylation, [Ca2+]i, [3H]‐arachidonate release, endocytosis). The agonist‐like effects of B‐9870 were inhibited by the B2R antagonist LF 16.0687 and absent in untransfected cells. In addition, B‐9870 was a surmontable antagonist of the rabbit B1R in the aorta contractility assay, and blocked Lys‐des‐Arg9‐BK‐induced ERK1/2 phosphorylation in HEK 293 cells expressing a fluorescent B1R conjugate. B‐9870 inhibited the growth of MDA‐MB‐231 cells. The latter effect was not influenced by B1R or B2R antagonists and was not apoptotic. MDA‐MB‐231 cells expressed a small population of B2Rs but no B1Rs; they responded to BK (small calcium transients) and B‐9870 behaved as an antagonist.

Conclusion and implications:

B‐9870 is a dual B1R and B2R antagonist with confirmed stimulating effects at the B2R in high expression systems only. Its cell type‐specific anti‐proliferative effect occurs at a high concentration, independently from kinin receptors and apoptosis.

British Journal of Pharmacology(2007)150, 369–379. doi:10.1038/sj.bjp.0706982
Identification of an antagonist that selectively blocks the activity of prostamides (prostaglandin‐ethanolamides) in the feline iris
Authors: Woodward D F , Krauss A H , Wang J W , Protzman C E , Nieves A L , Liang Y , Donde Y , Burk R M , Landsverk K , Struble C
Published: December 2006

Background and Purpose:

The prostamides (prostaglandin‐ethanolamides) and prostaglandin (PG) glyceryl esters are biosynthesized by COX‐2 from the respective endocannabinoids anandamide and 2‐arachidonyl glycerol. Agonist studies suggest that their pharmacologies are unique and unrelated to prostanoid receptors. This concept was further investigated using antagonists.

Experimental Approach:

The isolated feline iris was used as a key preparation, where prostanoid FP receptors and prostamide activity co‐exist. Activity at human recombinant FP and other prostanoid receptors was determined using stable transfectants.

Key Results:

In the feline iris, AGN 204396 produced a rightward shift of the dose‐response curves for prostamide F2αand the prostamide F2αanalog bimatoprost but did not block the effects of PGF2αand synthetic FP receptor agonists. Studies on human recombinant prostanoid receptors confirmed that AGN 204396 did not behave as a prostanoid FP receptor antagonist. AGN 204396 exhibited no antagonism at DP and EP1‐4, but was a highly effective TP receptor antagonist. Contrary to expectation, the FP receptor antagonist AL‐8810 efficaciously contracted the cat iris. AGN 204396 did not affect AL‐8810 induced contractions, demonstrating that AL‐8810 and AGN 204396 are pharmacologically distinct. Unlike AL‐8810, the ethylamide derivate of AL‐8810 was not an agonist. Al‐8810 did not block prostamide F2αactivity. Finally, AGN 204396 did not block PGE2‐glyceryl ester activity.

Conclusions and Implications:

The ability of AGN 204396 to selectively block prostamide responses suggests the existence of prostamide sensitive receptors as entities distinct from receptors recognizing PGF2αand PGE2‐glyceryl ester.

British Journal of Pharmacology(2007)150, 342–352. doi:10.1038/sj.bjp.0706989
Effects of budesonide on P‐glycoprotein expression in intestinal cell lines
Authors: Maier A , Zimmermann C , Beglinger C , Drewe J , Gutmann H
Published: December 2006

Background and purpose:

P‐glycoprotein (P‐gp) is an important efflux transporter that supports the barrier function of the gut against invading antigens and against administered drugs. Since glucocorticoids, such as budesonide, are frequently used during inflammatory bowel disease we investigated how budesonide influences P‐gp expression in different intestinal cell lines.

Experimental approach:

LS180 and Caco‐2 cells were incubated with budesonide and changes in P‐gp expression were determined on mRNA, protein and functional level. The mRNA expression levels of glucocorticoid receptor (GR) and pregnane X receptor (PXR) were determined in these cell lines. PXR receptor was transiently transfected into Caco‐2 cells.

Key results:

Budesonide showed an induction of P‐gp in LS180 cells and a down‐regulation in Caco‐2 cells. Expression levels of nuclear receptors revealed high expression ofPXRonly in LS180 cells and exclusive expression ofGRin Caco‐2 cells. Mifepristone, an anti‐glucocorticoid, could not reverse the down‐regulation of P‐gp by budesonide in Caco‐2 cells. InPXR‐transfected Caco‐2 cells the budesonide‐mediated down‐regulation of P‐gp was abolished. Furthermore the expression of cytochrome P450 3A4 (CYP3A4), another PXR target gene, was induced inPXR‐transfected Caco‐2 cells after budesonide treatment.

Conclusions and Implications:

Budesonide has the potential to influenceMDR1expressionin vitro. In LS180 cells, the induction ofMDR1by budesonide probably is mediated via PXR. The mechanism of the down‐regulation in Caco‐2 cells still remains unclear, but GR does not seem to be involved. Further studies are required to evaluate how budesonide alters P‐gp expressionin vivo.

British Journal of Pharmacology(2007)150, 361–368. doi:10.1038/sj.bjp.0706992
Comparative antagonist pharmacology at the native mouse bradykinin B2receptor: radioligand binding and smooth muscle contractility studies
Authors: Meini S , Cucchi P , Bellucci F , Catalani C , Giuliani S , Santicioli P , Maggi C A
Published: December 2006

Background and purpose:

The aim was to characterize the recently discovered non‐peptide antagonist MEN16132 at the mouse B2receptor, relative to other antagonists.

Experimental approach:

[3H]‐BK binding experiments used mouse lung and ileum tissue membranes and antagonist potency was measured in the isolated ileum contractility assay.

Key results:

Two BK binding sites resulted from saturation and homologous competition experiments. A role for the B1receptor was excluded because of the poor affinity of B1receptor ligands (pIC50<5). MEN16132, and the other reference antagonists, inhibited only one portion of BK specific binding, and the rank order of potency was (pIC50): Icatibant (lung 10.7; ileum 10.2)=MEN11270 (lung 10.4; ileum 9.9)=MEN16132 (lung 10.5; ileum 9.9). > LF16‐0687 (lung 8.9; ileum 8.8) > FR173657 (lung 8.6; ileum 8.2). BK homologous curves performed with lung membranes after treatment with the antagonist MEN16132 or Icatibant (10 nM) displayed only the low affinity site. The functional antagonism by MEN16132 (pA29.4) and Icatibant (pA29.1), towards BK (control EC506.1 nM) induced ileum contractions, was concentration‐dependent and surmountable, but the Schild plot slope was less than unity.

Conclusions and Implications:

In mouse tissue, radiolabelled BK recognizes two binding sites and B2receptor antagonists can compete only for the higher affinity one. The pharmacological profile of the novel non‐peptide antagonist MEN16132 indicates that it exhibits subnanomolar affinity and potency for the mouse B2receptor and is suitable for further characterization inin vivopathophysiological models.

British Journal of Pharmacology(2007)150, 313–320. doi:10.1038/sj.bjp.0706995
Heart rate reduction by inhibition of If or by β‐blockade has different effects on postsystolic wall thickening
Authors: Lucats L , Ghaleh B , Colin P , Monnet X , Bizé A , Berdeaux A
Published: December 2006

Background and purpose:

Postsystolic wall thickening (PSWT) is part of thickening that occurs after end‐systole and represents wasted effort as it does not contribute to ejection. The effects of antianginal drugs on PSWT remain to be established. We compared the effects on PSWT of two agents that reduce heart rate, the β‐blocker atenolol and the selective inhibitor of If current, ivabradine.

Experimental approach:

Six dogs were prepared to measure wall thickening by sonomicrometry in the conscious state, at rest and during exercise, after administration of saline, atenolol (1mg.kg‐1) or ivabradine (1mg.kg‐1).

Key results:

Atenolol and ivabradine similarly reduced heart rate vs saline at rest (about 10‐20%) and during exercise (about 30%). Atenolol but not ivabradine decreased dP/dtmax. Concomitantly, PSWT increased with atenolol vs saline at rest (0.35±0.07 vs 0.21±0.03mm, respectively) and during exercise (0.30±0.04 vs 0.15±0.04mm, respectively). In contrast, ivabradine did not alter PSWT. Importantly, atenolol but not ivabradine increased the ratio of postsystolic to systolic wall thickening by 80±23%. This enhanced thickening during diastole with atenolol was accompanied by impeded isovolumic relaxation of the left ventricle, as illustrated by the significant correlation between the isovolumic relaxation time constant τ and the postsystolic to systolic wall thickening ratio. None of these effects of atenolol were abolished when heart rate was controlled with atrial pacing.

Conclusion and implications:

For a similar heart rate reduction at rest and during exercise, ivabradine, but not atenolol, did not alter PSWT and preserved the part of thickening contributing to ejection.

British Journal of Pharmacology (2007) 150, 335–341. doi:10.1038/sj.bjp.0706996
Inelastic ball-plane impact: An accurate way to measure the normal restitution coefficient
Authors: Leconte M. , Garrabos Y. , Palencia F. , Lecoutre C. , Evesque P. , Beysens D.
Published: December 2006

The authors describe a setup to measure accurately the normal restitution coefficient between a quasiresonant ball and a plane. It uses the fact that the trajectory of a single ball in a cylindrical box with a vibrating wall reduces rapidly to a merely periodic one dimensional dynamics, with little rotation. The ball speed is measured accurately from the time series of impacts. It is also used to study and calibrate a sphere-plane impact sensor. This sensor allows to determine the collision time at a microsecond accuracy and the maximum force applied. The collision is found to obey the Hertz law.
Ultraviolet-visible absorption spectra of N-doped TiO2 film deposited on sapphire
Authors: Park Jaewon , Lee Jung-Yup , Cho Jun-Hyung
Published: December 2006

The optical-response properties of nitrogen(N)-doped titanium dioxide (TiO2) films are investigated by means of a combination of ultraviolet-visible absorption spectroscopy and first-principles density-functional calculations. The TiO2 films were epitaxially grown on the sapphire substrate by the pulsed laser deposition method. The doping of N atoms was achieved by 70keV of N+ ion implantation, followed by postirradiation heat treatment at 550°C for 2h in air. We find that when 5×1016 (1×1017)Nions∕cm2 were implanted into the epitaxially grown TiO2 film, the absorption edge is reproducibly shifted to lower energy by about 0.06 (0.12)eV together with a significant optical absorption extending into the visible-light region. These experimental data can be explained by our calculated band structure of N-doped TiO2, where the bands originating from N 2p states locate above the valence band edge, while the band gap narrowing due to the mixing of N with O 2p states is 0.04eV.
Microtopologies in polymer surfaces by solvent drops in contact and noncontact mode
Authors: Li Guangfen , Höhn Nobert , Graf Karlheinz
Published: December 2006

A method for the generation of protruded microstructures in polymer surfaces with an evaporating solvent drop, provided by a homemade syringe system, is presented. Either a concave surface topology is obtained by exposing the polymer surface to the vapor of a pendent solvent drop (noncontact mode) or a solvent drop is deposited on the polymer by moving the substrate up and down (contact mode). Thus a liquid bridge between syringe tip and polymer surface is formed and even convex microstructures can be generated for slow substrate retraction.
Template-nonlithographic nanopatterning for site control growth of InGaN nanodots
Authors: Wang Y. D. , Zang K. Y. , Chua S. J. , Fonstad C. G.
Published: December 2006

A site-control nucleation and growth approach for dense InGaN nanodots has been demonstrated on the surface of GaN using a nonlithographic nanopatterning technique by metal organic chemical vapor deposition. Shallow nanopore arrays with a depth of ∼15nm are created by inductively coupled plasma etching in the GaN surface using anodic aluminum oxide films as etch masks. The nanopores are found to be the preferential sites for the InGaN nanodot formation. Uniform InGaN nanodot arrays with a density as high as 1010∕cm2 as defined by the nanopores in GaN were observed on the surface. A strong photoluminescence (PL) emission peak near 2.8eV is observed from the InGaN nanodots. The temperature dependence of PL shows the enhanced carrier localization with higher activation energy in the InGaN nanodots when compared to the InGaN thin layer grown simultaneously on the nonpatterned GaN surface.
Quantitative determination of the O(P3) density via visible cavity-enhanced spectroscopy
Authors: Gupta Manish , Owano Thomas , Baer Douglas , O’Keefe Anthony
Published: December 2006

A simple method has been developed to quantitatively measure the ground state oxygen atom, O(P3), density. The technique exploits cavity-enhanced spectroscopy to probe the relatively weak O(D1)←O(P13) transition near 636nm. O(P13) densities of approximately 3.4×1014at.∕cm3 were measured in an inductively coupled plasma produced within a high-finesse optical cavity, and a minimum detectable atom state density of 1.3×1012at.∕cm3 was determined. The absorption profile yielded a translational temperature of 453K. The technique can be readily extended to other atomic species.
Intramolecular Hydrolysis of Coordinated Acetonitrile in a Binuclear Complex of Cobalt(III): X-Ray Crystallographic Analysis of Salts of [(tren)Co(μ-NH2,μ-L)Co(tren)]4+(L=OH, CH3C(O)NH)
Authors: Alcock NW , Creaser II , Curtis NJ , Roecker L , Sargeson AM , Willis AC
Published: December 2006

A synthesis of [( tren )Co(μ-NH2,μ-OH)Co( tren )]4+(3)( tren = tris (2- aminoethyl )amine) is reported along with a series of derivatives: [( tren ) XCo (μ-NH2) CoX ( tren )]n+, where X = CF3SO3- (n = 3)(4), X = CH3CN (n = 5)(5), and [( tren )Co(μ-NH2,μ-CH3C(O)NH)Co( tren )]4+ (6). The substitution of (4) by CH3CN to yield (5) was studied in CH3CN at 20°C, k = 9.0×10-3 s-1, and the intramolecular hydrolysis of (5) to yield the bridging acetamide complex (6) was studied at various acid concentrations. The X-ray crystal structures were determined for (3b) (exafluorophosphate, dihydrate) and (6b) (dithionate, tetrahydrate ). Both crystals are monoclinic, respectively P21/n with a 11.082(2), b 10.402(2), c 15.611(2)Ǻ, β 99.13(2)°, Z 2, and C2/c with a 14.328(2), b 14.046(1), c 16.497(2)Ǻ, β 101.90(1)°, Z 4. For the salt of (3), 2389 data with 1 ≥ 2σ(I) were refined to R 0.070 ( Rw 0.066), and, for the salt of (6), 3087 data with I ≥ 3σ(I) were refined to R 0.041 ( Rw 0.056). Both ions lie on pseudo-symmetric sites involving disorder of the bridging ligands . The structures establish the binding mode of the acetamido ion and the orientation of the tren groups in the isolated complexes.
Rac1 and a GTPase-activating protein, MgcRacGAP, are required for nuclear translocation of STAT transcription factors
Authors: Kawashima Toshiyuki , Bao Ying Chun , Nomura Yasushi , Moon Yuseok , Tonozuka Yukio , Minoshima Yukinori , Hatori Tomonori , Tsuchiya Akiho , Kiyono Mari , Nosaka Tetsuya , Nakajima Hideaki , Williams David A. , Kitamura Toshio
Published: December 2006

STAT transcription factors are tyrosine phosphorylated upon cytokine stimulation and enter the nucleus to activate target genes. We show that Rac1 and a GTPase-activating protein, MgcRacGAP, bind directly to p-STAT5A and are required to promote its nuclear translocation. Using permeabilized cells, we find that nuclear translocation of purified p-STAT5A is dependent on the addition of GTP-bound Rac1, MgcRacGAP, importin α, and importin β. p-STAT3 also enters the nucleus via this transport machinery, and mutant STATs lacking the MgcRacGAP binding site do not enter the nucleus even after phosphorylation. We conclude that GTP-bound Rac1 and MgcRacGAP function as a nuclear transport chaperone for activated STATs.
Actin turnover–dependent fast dissociation of capping protein in the dendritic nucleation actin network: evidence of frequent filament severing
Authors: Miyoshi Takushi , Tsuji Takahiro , Higashida Chiharu , Hertzog Maud , Fujita Akiko , Narumiya Shuh , Scita Giorgio , Watanabe Naoki
Published: December 2006

Actin forms the dendritic nucleation network and undergoes rapid polymerization-depolymerization cycles in lamellipodia. To elucidate the mechanism of actin disassembly, we characterized molecular kinetics of the major filament end-binding proteins Arp2/3 complex and capping protein (CP) using single-molecule speckle microscopy. We have determined the dissociation rates of Arp2/3 and CP as 0.048 and 0.58 s−1, respectively, in lamellipodia of live XTC fibroblasts. This CP dissociation rate is three orders of magnitude faster than in vitro. CP dissociates slower from actin stress fibers than from the lamellipodial actin network, suggesting that CP dissociation correlates with actin filament dynamics. We found that jasplakinolide, an actin depolymerization inhibitor, rapidly blocked the fast CP dissociation in cells. Consistently, the coexpression of LIM kinase prolonged CP speckle lifetime in lamellipodia. These results suggest that cofilin-mediated actin disassembly triggers CP dissociation from actin filaments. We predict that filament severing and end-to-end annealing might take place fairly frequently in the dendritic nucleation actin arrays.