bluuebunny/crossref_metadata_2025 huggingface dataset:
On spherical harmonics expansion type modelsfor electron–phonon collisions
Authors: Bourgade J.‐P.
Published: January 2003

In this paper, we give the rigorous derivation of a diffusion model for semiconductor devices, the starting point being a microscopic description of electron transport by means of a kinetic equation of Boltzmann type. The limit of a small mean free path at a large time leads to a diffusion equation of ‘SHE’ type (spherical harmonics expansion). We deal with a collision operator that models interactions between electron and phonons. This induces a peculiar form for the diffusion tensor: electron–phonon collisions happen to be discontinuous in energy and inelastic, and, as a consequence, the diffusion tensor appears as an infinite dimensional matrix. Copyright © 2003 John Wiley & Sons, Ltd.
Analysis of clustered matched‐pair data for a non‐inferiority study design
Authors: Durkalski Valerie L. , Palesch Yuko Y. , Lipsitz Stuart R. , Rust Philip F.
Published: January 2003

Hypothesis testing of matched‐pair data has been adapted for equivalence (one‐ and two‐sided) study designs; however, a statistical problem arises when more than one measurement is recorded for each study subject. Ignoring the correlation between the repeated measurements per subject may underestimate the standard error of the parameter estimate. A method of testing for non‐inferiority or equivalence of clustered matched‐pair data is not yet available. This paper proposes a Wald‐type test statistic for a non‐inferiority hypothesis and applies it to the comparison of two diagnostic procedures. Copyright © 2003 John Wiley & Sons, Ltd.
Consistent database sampling as a database prototyping approach
Authors: Bisbal Jesús , Grimson Jane
Published: January 2003

Requirements elicitation has been reported to be the stage of software development when errors have the most expensive consequences. Users usually find it difficult to articulate a consistent and complete set of requirements at the beginning of a development project. Prototyping is considered a powerful technique to ease this problem by exposing a partial implementation of the software system to the user, who can then identify required modifications. When prototyping data‐intensive applications a so‐called prototype database is needed.

This paper investigates how a prototype database can be built. Two different approaches are analysed, namely test databases and sample databases; the former populates the resulting database with synthetic values, while the latter uses data values from an existing database. The application areas that require prototype databases, in addition to requirements analysis, are also identified. The paper reports on existing research into the construction of both types of prototype databases, and indicates to which type of application area each is best suited. This paper advocates for the use of sample databases when an operational database is available, as is commonly the case in software maintenance and evolution. Domain‐relevant data values and integrity constraints will produce a prototype database which will support the information system development process better than synthetic data. The process of extracting a sample database is also investigated. Copyright © 2002 John Wiley & Sons, Ltd.
Two new species in the lichen genus Szczawinskia A. Funk
Authors: Holien H. , Tønsberg T.
Published: January 2003

Szczazvinskia leucopoda Holien & Tønsberg and 5. foliicola Holien & Tønsberg are described from coastal Central Norway and Newfoundland, and from Papua New Guinea, respectively.
Immobilization stress elevates IP3 receptor mRNA in adult rat hearts in a glucocorticoid‐dependent manner
Authors: Lencesova Lubomira , Ondrias Karol , Micutkova Lucia , Filipenko Maxim , Kvetnansky Richard , Krizanova Olga
Published: January 2003

Gene expression of the type 1 and 2 inositol 1,4,5‐trisphosphate (IP3) receptors in the rat cardiac atria and ventricles and their possible modulation by single immobilization stress was studied. Single immobilization stress significantly elevated mRNA levels for both types of these receptors. To evaluate the involvement of glucocorticoids in the modulation of the gene expression of IP3 receptors by immobilization stress, we used adrenalectomized and/or hypophysectomized rats. Since adrenalectomy and/or hypophysectomy completely abolished increase in IP3 receptor's mRNA levels after the immobilization, we conclude that immobilization stress elevates mRNA of type 1 and 2 IP3 receptors, mainly through the glucocorticoid responsive element.
ATP depletion increases phosphorylation of elongation factor eEF2 in adult cardiomyocytes independently of inhibition of mTOR signalling
Authors: McLeod Laura E , Proud Christopher G
Published: January 2003

Translation elongation consumes a high proportion of cellular energy and can be regulated by phosphorylation of elongation factor eEF2 which inhibits its activity. We have studied the effects of ATP depletion on the phosphorylation of eEF2 in adult rat ventricular cardiomyocytes. Energy depletion rapidly leads to inhibition of protein synthesis and increased phosphorylation of eEF2. Stimulation of the AMP‐activated protein kinase also causes increases eEF2 phosphorylation. Only at later times is an effect on mTOR signalling observed. These data suggest that energy depletion leads to inhibition of protein synthesis through phosphorylation of eEF2 independently of inhibition of mTOR signalling.
Determination of the orientation of the axial ligands and of the magnetic properties of the haems in the tetrahaem ferricytochrome from Shewanella frigidimarina
Authors: Louro Ricardo O , Pessanha Miguel , Reid Graeme A , Chapman Stephen K , Turner David L , Salgueiro Carlos A
Published: January 2003

The unambiguous assignment of the nuclear magnetic resonance (NMR) signals of the α‐substituents of the haems in the tetrahaem cytochrome isolated from Shewanella frigidimarina NCIMB400, was made using a combination of homonuclear and heteronuclear experiments. The paramagnetic 13C shifts of the nuclei directly bound to the porphyrin of each haem group were analysed in the framework of a model for the haem electronic structure. The analysis yields g‐tensors for each haem, which allowed the assignment of some electron paramagnetic resonance (EPR) signals to specific haems, and the orientation of the magnetic axes relative to each haem to be established. The orientation of the axial ligands of the haems was determined semi‐empirically from the NMR data, and the structural results were compared with those of the homologous tetrahaem cytochrome from Shewanella oneidensis MR‐1 showing significant similarities between the two proteins.
Pedicular fixation in the osteoporotic spine: a pilot in vivo study on long‐term ovariectomized sheep
Authors: Nicoli Aldini N. , Fini M. , Giavaresi G. , Giardino R. , Greggi T. , Parisini P.
Published: January 2003

Spinal instrumentation success is greatly affected by the presence of osteoporosis. To date, however, no data exist on in vivo investigations on biomaterial and surgical techniques in the osteoporotic spine. In the present study 24 uncoated and 24 HA‐coated screws were implanted in the L3, L4 and L5 pedicles of eight sheep (four ovariectomized, OVX Group; four sham‐operated, Control Group). At four months, uncoated screws showed a significant decrease of about −22% in the extraction torque of the OVX Group as compared to the Control Group (p < 0.005). The extraction torque of HA‐coated screws significantly (p < 0.0005) improved in both groups when compared to that of uncoated screws and showed increases ranging from 133% to 157%. Pedicle trabecular bone of OVX sheep showed a significant decrease in BV/TV (−30%; p < 0.05) and Tb.Th (−33%; p < 0.01). The affinity index (AI) results revealed significant (p < 0.0005) differences between uncoated and HA‐coated screws for both groups: values were lower for uncoated than HA‐coated screws by about −35%. A significant difference was also found for the AI data of uncoated screws between the OVX and Control Groups ( − 13%, p < 0.005). The current findings have demonstrated that long‐term ovariectomized sheep can be used to study in vivo osteointegration in the osteoporotic spine. The HA coating has proven to improve bone purchase and bone‐screw interface strength in healthy and osteopenic animals.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Titanium particles suppress expression of osteoblastic phenotype in human mesenchymal stem cells
Authors: Wang Mark L. , Nesti Leon J. , Tuli Richard , Lazatin Jovin , Danielson Keith G. , Sharkey Peter F. , Tuan Rocky S.
Published: January 2003

Long‐term stability of arthroplasty prosthesis depends on the integration between osseous tissue and the implant biomaterial. Integrity of the osseous tissue requires the contribution of mesenchymal stem cells and their continuous differentiation into an osteoblastic phenotype. This study aims to investigate the hypothesis that exposure to wear debris particles derived from orthopaedic biomaterials affects the osteoblastic differentiation of human mesenchymal stem cells (hMSC). Upon in vitro culture in the presence of osteogenic supplements (OS), we observe that cultures of hMSCs isolated from femoral head bone marrow are capable of osteogenic differentiation, expressing alkaline phosphatase, osteocalcin, and bone sialoprotein (BSP), in addition to producing collagen type I and BSP accompanied by extracellular matrix mineralization. Exposure of OS‐treated hMSCs to submicron commercially pure titanium (cpTi) particles suppresses BSP gene expression, reduces collagen type I and BSP production, decreases cellular proliferation and viability, and inhibits matrix mineralization. In comparison, exposure to zirconium oxide (ZrO2) particles of similar size did not alter osteoblastic gene expression and resulted in only a moderate decrease in cellular proliferation and mineralization. Confocal imaging of cpTi‐treated hMSC cultures revealed patchy groups of cells displaying disorganized cyto‐skeletal architecture and low levels of extracellular BSP. These in vitro findings suggest that chronic exposure of marrow cells to titanium wear debris in vivo may contribute to decreased bone formation at the bone/implant interface by reducing the population of viable hMSCs and compromising their differentiation into functional osteoblasts. Understanding the nature of hMSC bioreactivity to orthopaedic wear debris should provide additional insights into mechanisms underlying aseptic loosening.

Published by Elsevier Science Ltd. on behalf of Orthopaedic Research Society.
“She has done me no work”: language and power asymmetry in impoverished families in Poland
Authors: Jastrzebska-Szklarska Joanna
Published: January 2003

Based on an in-depth semantic analysis of interviews with poor Polish couples living in a foreclosed state farm and the examination of the so-called “linguistic sexism” of the Polish language, the author shows that despite a manifest change in the social context of poor households, power relations within impoverished rural married couples still remain the same. The traditional power imbalance can be observed at the level of the respondents' utterances, especially with regard to gender roles, work and household duties, dowries and inheritance. In households with downwardly mobile men, husbands tend to assert even more symbolic power than in households in which the husbands have jobs, even if low-paying ones. Wives of downwardly mobile men in the community studied are inclined to verbally support their husbands and patriarchal family relations, despite the fact that often the traditional basis of patriarchy—economic providership—is now women's responsibility also.
Lithospheric structure of the central Andes based on surface wave dispersion
Authors: Baumont David , Paul Anne , Zandt George , Beck Susan L. , Pedersen Helle
Published: January 2003

Shear wave velocity is very sensitive to temperature anomalies and partial melt and can provide important insights on the state of the lithosphere. With that aim in mind, phase velocities of Rayleigh and Love waves have been inverted for the regionalized shear wave velocity structure of the lithosphere across the central Andes. This inversion reveals strong lateral variations of Vs both across the range and along‐strike in the Altiplano crust. In the upper crust, the main features of our models are prominent low‐velocity anomalies probably related to partial melt below the Los Frailes ignimbrite complex and the southern Altiplano. At lower crustal level, the Altiplano is characterized by lower Vs than the surrounding regions. We find that the transition from the Altiplano to the Puna is associated with a 7‐km thickening of the crust. At mantle depths, the Nazca plate is found to be overlaid by a dipping low‐velocity zone with decreasing intensity with depth. Our results favor the idea of a cold mantle lid underlying the whole central Andes.
Thermal models of the Mexico subduction zone: Implications for the megathrust seismogenic zone
Authors: Currie C. A. , Hyndman R. D. , Wang K. , Kostoglodov V.
Published: January 2003

It has been proposed that the seismogenic zone of subduction thrust faults is primarily controlled by temperature or rock composition changes. We have developed numerical models of the thermal structure of the Mexico subduction zone to examine the factors that affect the temperature of the subduction thrust fault. Although the oceanic plates subducting beneath Mexico are young, the top of the oceanic plate at the trench is cool, because of the lack of a thick cover of insulating sediments. Marine heat flow observations suggest that hydrothermal circulation may further cool the oceanic plate. This results in a cool subduction thrust fault, where the brittle part of the fault extends to depths of over 40 km. At these depths, even slight frictional heating may have significant effects on temperature along the thrust fault, particularly for regions with a high convergence rate and shallow plate dip. With the addition of a small amount of frictional heating, the temperatures of the deep (30–40 km) thrust fault are increased by over 200°C. As the observed downdip limit of rupture in recent well‐constrained megathrust earthquakes is confined to depths above the intersection of the thrust fault and the continental Moho, a temperature of 350°C may control the downdip extent of the seismogenic zone. Thus, in order to be consistent with the observed shallow rupture areas, it is necessary to include a small amount of frictional heating, corresponding to an average shear stress of 15 MPa.
Chemical composition of aerosol, sea fog, and rainwater in the marine boundary layer of the northwestern North Pacific and its marginal seas
Authors: Sasakawa Motoki , Uematsu Mitsuo
Published: January 2003

Samples of aerosol, sea fog, and rainwater were collected during a research cruise in the northwestern North Pacific, the Sea of Okhotsk, and the Sea of Japan in the summer of 1998. High concentrations of NO3−, nss‐SO42− and NH4+ in aerosol over the Sea of Japan suggest that anthropogenic substances were transported to this region. Although the Sea of Okhotsk was covered with a clean marine air mass, the concentration of nss‐SO42− was comparatively high in the aerosol samples. This nss‐SO42− is probably of marine biogenic origin. The pH values of fogwater samples were measured to be <3.0 over the Sea of Okhotsk and the Sea of Japan. The concentrations of NO3− and NH4+ in the fogwater collected over the Sea of Japan were higher than those in the other regions, suggesting that the sea fog scavenged anthropogenic substances. The concentration of nss‐SO42− in fogwater over the Sea of Okhotsk was equivalent to that over the Sea of Japan, probably because nss‐SO42− and SO2 of marine biogenic origin were scavenged by the sea fog over the Sea of Okhotsk. The pH values of rainwater samples ranged from 6.1 to 7.2 during the cruise, and acidification of the rain was not significant. The concentrations of nss‐Ca2+ in the rainwater were higher than those of the fogwater. This suggests that the rain‐scavenged continental CaCO3 may have existed above the lower marine boundary layer, where sea fog appeared. Comparisons of the composition of aerosol and fogwater indicated that coarse particles, such as sea salts predominantly act as condensation nuclei of sea fog droplets rather than fine particles such as (NH4)2SO4.
Seasonal and inter‐annual variability of particulate organic matter in the global ocean
Authors: Loisel Hubert , Nicolas Jean‐Marc , Deschamps Pierre‐Yves , Frouin Robert
Published: January 2003

The geographic distribution and seasonal to inter‐annual variability of the particulate backscattering coefficient, bbp, is described and compared with that of chlorophyll concentration, Chl. Both variables are obtained from satellite‐derived ocean color and inverse modeling. In general, bbp exhibits larger seasonal variations than Chl, and the bbp values are more evenly distributed in space, especially at low and middle latitudes. A phase shift between the annual cycles of bbp and Chl is evidenced, and is attributed to the presence of an important pool of non‐pigmented particles. Converting bbp to particulate organic carbon, POC, the annual mean surface POC pool between 60°S and 60°N is about 19 Tg C per meter.
On the evolution of pollution from South and Southeast Asia during the winter‐spring monsoon
Authors: Phadnis Mahesh J. , Levy Hiram , Moxim Walter J.
Published: January 2003

The NOAA Geophysical Fluid Dynamics Laboratory three‐dimensional Global Chemical Transport Model (GFDL GCTM) is used to examine the winter‐spring evolution of pollution (fossil fuel combustion and biomass burning) from South and Southeast Asia with special focus on the Indian Ocean region. We find that during the monsoonal winter‐spring outflow, pollution over the Indian Ocean north of the ITCZ is concentrated in the maritime boundary layer and originates from both regions. South Asian emissions dominate over the Arabian Sea and the Western Indian Ocean, while the Southeast Asian emissions have the greatest impact over the Bay of Bengal and Eastern Indian Ocean. Over these oceanic regions, CO pollution in both source regions, most of which is from biomass burning, accounts for 30–50% of the boundary layer CO. It is transported equatorward from South and Southeast Asian source regions and episodically lofted into the upper troposphere by tropical convection events. This transport path has a noticable impact (10–20%) on total CO at 300 mb and produces a maximum in a tropical belt over and north of the ITCZ. Another free troposphere transport path, primarily open to Southeast Asian emissions, carries CO from that region out over the North Pacific and around the Northern Hemisphere. O3 production is driven by NOx, which, unlike CO, comes almost equally from biomass burning and fossil fuel combustion in this region and has a chemical lifetime of a few days or less. The resulting NOx distributions, while qualitatively similar to CO, have much steeper gradients, are transported much less widely, have a much lower background, and over the Indian and Pacific Oceans, are strongly dominated by pollution. O3 resulting from these anthropogenic sources generally exhibits patterns similar to those found for CO and NOx. Pollution accounts for 20–50% of the near‐surface O3 and 5–10% of the O3 in the upper troposphere. South and Southeast Asian emissions only produce 25% of the boundary layer O3 in the continental source regions. The maximum impact of the emissions occurs over the Indian Ocean (25–40%) with comparable contributions from O3 produced in the continental emission regions and O3 produced over the ocean by transported precursors. Convective lifting of the transported pollution O3 supplies ∼10% of the O3 in the tropical upper troposphere. While both emission regions have modest impacts on O3 (5–10%) outside of the Indian Ocean region, Southeast Asian pollution impacts free troposphere O3 in a midlatitude belt across the North Pacific, similar to NOx.
Observations of deep convection in the tropics using the Tropical Rainfall Measuring Mission (TRMM) precipitation radar
Authors: Alcala C. M. , Dessler A. E.
Published: January 2003

A satellite‐borne precipitation radar is used to study the penetration of convection bearing large particles to altitudes around the tropical tropopause, a region now known as the tropical tropopause layer (TTL). This overshooting convection has been identified as potentially important in the dehydration of air entering the stratosphere. The global distribution of the radar reflectivity tops in the TTL follows the interseasonal and interannual patterns of the surface precipitation rates. The amount of overshooting convection is ∼5% of total deep convection and ∼1.5% of the total convective rain. In agreement with previous studies, the radar observations show that continental convection typically extends to higher altitudes than oceanic convection.
Climate and landscape controls on water balance model complexity over changing timescales
Authors: Atkinson S. E. , Woods R. A. , Sivapalan M.
Published: January 2003

A systematic approach is described for determining the minimum level of model complexity required to predict runoff in New Zealand catchments, with minimal calibration, at decreasing timescales. Starting with a lumped conceptual model representing the most basic hydrological processes needed to capture water balance, model complexity is systematically increased in response to demonstrated deficiencies in model predictions until acceptable accuracy is achieved. Sensitivity and error analyses are performed to determine the dominant physical controls on streamflow variability. It is found that dry catchments are sensitive to a threshold storage parameter, producing inaccurate results with little confidence, while wet catchments are relatively insensitive, producing more accurate results with more confidence. Sensitivity to the threshold parameter is well correlated with climate and timescale, and in combination with the results of two previous studies, this allowed the postulation of a qualitative relationship between model complexity, timescale, and the climatic dryness index (DI). This relationship can provide an a priori understanding of the model complexity required to accurately predict streamflow with confidence in small catchments under given climate and timescales and a conceptual framework for model selection. The objective of the paper is therefore not to present a perfect model for any of the catchments studied but rather to present a systematic approach to modeling based on making inferences from data that can be applied with respect to different model designs, catchments and timescales.
Acetylcholine‐induced vasodilation may depend entirely upon NO in the femoral artery of young piglets
Authors: Støen Ragnhild , Lossius Kristin , Karlsson Jan Olof G
Published: January 2003

To characterize agonist‐induced relaxation in femoral artery rings from young piglets, we compared the effect of a NOS‐inhibitor Nω‐nitro‐L‐arginine (L‐NOARG), an NO‐inactivator oxyhaemoglobin (HbO) and a soluble guanyl cyclase(sGC)‐inhibitor 1H‐[1,2,4]Oxadiazolo‐[4,3,‐α]quinoxalin‐1‐one (ODQ) on acetylcholine(ACh)‐induced relaxation. The involvement of K+ channel activation was studied on relaxations induced by ACh, the two NO donors sodium nitroprusside (SNP) and diethylamine (DEA) NONOate, and the cell membrane permeable guanosine 3′5′ cyclic monophosphate (cGMP) analogue 8‐Br‐cGMP.

Full reversal of phenylephrine‐mediated precontraction was induced by ACh (1 nM–1 μM) (pD2 8.2±0.01 and Rmax 98.7±0.3%). L‐NOARG (100 μM) partly inhibited relaxation (pD2 7.4±0.02 and Rmax 49.6±0.8%). The L‐NOARG/indomethacin(IM)‐resistant response displayed characteristics typical for endothelium‐derived hyperpolarizing factor (EDHF), being sensitive to a combination of the K+ channel blockers charybdotoxin (CTX) (0.1 μM) and apamin (0.3 μM).

ODQ (10 μM) abolished relaxations induced by ACh and SNP. L‐NOARG/IM‐resistant relaxations to ACh were abolished by HbO (20 μM).

Ouabain (1 μM) significantly inhibited ACh‐induced L‐NOARG/IM‐resistant relaxations and relaxations induced by SNP (10 μM) and 8‐Br‐cGMP (0.1 mM). A combination of ouabain and Ba2+ (30 μM) almost abolished L‐NOARG/IM‐resistant ACh‐induced relaxation (Rmax 7.7±2.5% vs 23.4±6.4%, with and without Ba2+, respectively, P<0.05).

The present study demonstrates that in femoral artery rings from young piglets, despite an L‐NOARG/IM‐resistant component sensitive to K+ channel blockade with CTX and apamin, ACh‐induced relaxation is abolished by sGC‐inhibition or a combination of L‐NOARG and HbO. These findings suggest that relaxation can be fully explained by the NO/cGMP pathway.

British Journal of Pharmacology (2003) 138, 39–46. doi:10.1038/sj.bjp.0705001
Pharmacological profiles of presynaptic nociceptin/orphanin FQ receptors modulating 5‐hydroxytryptamine and noradrenaline release in the rat neocortex
Authors: Marti Matteo , Stocchi Sara , Paganini Francesca , Mela Flora , Risi Carmela De , Calo' Girolamo , Guerrini Remo , Barnes Timothy A , Lambert David G , Beani Lorenzo , Bianchi Clementina , Morari Michele
Published: January 2003

The pharmacological profiles of presynaptic nociceptin/orphanin FQ (N/OFQ) peptide receptors (NOP) modulating 5‐hydroxytryptamine (5‐HT) and noradrenaline (NE) release in the rat neocortex were characterized in a preparation of superfused synaptosomes challenged with 10 mM KCl.

N/OFQ concentration‐dependently inhibited K+‐evoked [3H]‐5‐HT and [3H]‐NE overflow with similar potency (pEC50 ∼7.9 and ∼7.7, respectively) and efficacy (maximal inhibition ∼40%).

N/OFQ (0.1 μM) inhibition of [3H]‐5‐HT and [3H]‐NE overflow was antagonized by selective NOP receptor antagonists of peptide ([Nphe1]N/OFQ(1‐13)NH2 and UFP‐101; 10 and 1 μM, respectively) and non‐peptide (J‐113397 and JTC‐801; both 0.1 μM) nature. Antagonists were routinely applied 3 min before N/OFQ. However, a 21 min pre‐application time was necessary for J‐113397 and JTC‐801 to prevent N/OFQ inhibition of [3H]‐NE overflow.

The NOP receptor ligand [Phe1ψ(CH2‐NH)Gly2]N/OFQ(1‐13)NH2 ([F/G]N/OFQ(1‐13)NH2; 3 μM) did not affect K+‐evoked [3H]‐NE but inhibited K+‐evoked [3H]‐5‐HT overflow in a UFP‐101 sensitive manner. [F/G]N/OFQ(1‐13)NH2 antagonized N/OFQ actions on both neurotransmitters.

The time‐dependency of JTC‐801 action was studied in CHO cells expressing human NOP receptors. N/OFQ inhibited forskolin‐stimulated cAMP accumulation and JTC‐801, tested at different concentrations (0.1–10 μM) and pre‐incubation times (0, 40 and 90 min), antagonized this effect in a time‐dependent manner. The Schild‐type analysis excluded a competitive type of antagonism.

We conclude that presynaptic NO receptors inhibiting 5‐HT and NE release in the rat neocortex have similar pharmacological profiles. Nevertheless, they can be differentiated pharmacologically on the basis of responsiveness to [F/G]N/OFQ(1‐13)NH2 and time‐dependent sensitivity towards non‐peptide antagonists.

British Journal of Pharmacology (2003) 138, 91–98. doi:10.1038/sj.bjp.0705005
Bradykinin inhibits development of myocardial infarction through B2 receptor signalling by increment of regional blood flow around the ischaemic lesions in rats
Authors: Ito Hiroshi , Hayashi Izumi , Izumi Tohru , Majima Masataka
Published: January 2003

To identify the roles of endogenous kinins in prevention of myocardial infarction (MI), we performed the permanent ligation of coronary artery in rats.

The size of MI 12, 24, and 48 h after coronary ligation in kininogen‐deficient Brown Norway Katholiek (BN‐Ka) rats was significantly larger (49.7±0.2%, 49.6±2%, and 51.1±1%, respectively) than that of kinin‐replete Brown Norway Kitasato (BN‐Ki) rats (42±2%, 38.5±4%, and 41.5±1%).

Hoe140, a bradykinin (BK) B2 receptor antagonist injected (1.0 mg kg−1, i.v.) half an hour before, and every 8 h after, coronary ligation, significantly increased the size of MI in Sprague‐Dawley rats. Aprotinin, a kallikrein inhibitor, which was infused intravenously (10,000 Units kg−1 h−1) with an osmotic mini‐pump, significantly increased the size of an MI 24 h after ligation.

When evaluated using microspheres, the regional myocardial blood flow around the necrotic lesion in BN‐Ka rats 6 h after ligation was reduced more than that in BN‐Ki rats with MI by 41–46%. The same was true in Hoe140‐treated BN‐Ki rats.

FR190997, a nonpeptide B2 agonist, which was infused (10 μg kg−1 h−1) into the vena cava of BN‐Ka rats for 24 h with an osmotic mini‐pump, caused significant reduction in the size of MI (38±3%), in comparison with the size in vehicle solution‐treated rats (51±3%). The size of MI in FR190997‐treated BN‐Ka rats was the same as in BN‐Ki rats.

These results suggested that endogenous kinin has the capacity to reduce the size of MI via B2 receptor signalling because of the increase in regional myocardial blood flow around the ischaemic lesion.

British Journal of Pharmacology (2003) 138, 225–233. doi:10.1038/sj.bjp.0705013
Evidence against β3‐adrenoceptors or low affinity state of β1‐adrenoceptors mediating relaxation in rat isolated aorta
Authors: Brahmadevara Nataraj , Shaw Angus M , MacDonald Allan
Published: January 2003

The presence of β3‐adrenoceptors and the low affinity state of the β1‐adrenoceptor (formerly ‘putative β4‐adrenoceptor’) was investigated in ring preparations of rat isolated aorta preconstricted with phenylephrine or prostaglandin F2α (PGF2α). Relaxant responses to isoprenaline, selective β3‐adrenoceptor agonists (BRL 37344, SR 58611A, CL 316243) and non‐conventional partial agonists (CGP 12177A, cyanopindolol, pindolol) were obtained.

In phenylephrine‐constricted, but not PGF2α‐constricted rings, relaxations to isoprenaline showed a propranolol‐resistant component.

In phenylephrine‐constricted rings, relaxations to BRL 37344 (pEC50, 4.64) and SR 58611A (pEC50, 4.94) were not antagonized by the selective β3‐adrenoceptor antagonist SR 59230A (1 μM). CL 316243 (100 μM) failed to produce relaxation. In PGF2α‐constricted rings only SR 58611A produced relaxation, which was not affected by SR 59230A (3 μM).

Non‐conventional partial agonists produced relaxation in phenylephrine‐constricted but not PGF2α‐constricted rings. The relaxation to CGP 12177A was unaffected by SR 59230A (1 μM) or by CGP 20712A (10 μM), reported to block the low affinity state of the β1‐adrenoceptor.

β‐adrenoceptor antagonists also produced relaxation in phenylephrine‐constricted rings with an order of potency of (pEC50 values): bupranolol (5.5)∼38;SR 59230A (5.47)∼38;cyanopindolol (5.47)>pindolol (5.30)>alprenolol (5.10)>propranolol (4.83)>ICI 118551 (4.60)>CGP 12177A (4.38)∼38;CGP 20712A (4.35). Bupranolol (100 μM), alprenolol (30 μM), propranolol (100 μM) and SR 59230A (10 μM) produced no relaxation in PGF2α‐constricted rings.

These results provide no evidence for the presence of functional β3‐adrenoceptors or the low affinity state of the β1‐adrenoceptor in rat aorta.

British Journal of Pharmacology (2003) 138, 99–106. doi:10.1038/sj.bjp.0705017
α1‐Adrenoceptor effects mediated by protein kinase C α in human cultured prostatic stromal cells
Authors: Preston A , Haynes J M
Published: January 2003

We have investigated the effects of α1‐adrenoceptor stimulation upon contractility, Ca2+ influx, inositol phosphate production, and protein kinase C (PKC) translocation in human cultured prostatic stromal cells (HCPSC).

The α1‐adrenoceptor selective agonist phenylephrine elicited contractile responses of HCPSC, i.e. a maximal cell shortening of 45±6% of initial cell length, with an EC50 of 1.6±0.1 μM. The α1‐adrenoceptor selective antagonists prazosin (1 μM) and terazosin (1 μM) both blocked contractions to phenylephrine (10 μM). The L‐type calcium channel blocker nifedipine (10 μM), and the PKC inhibitors Gö 6976 (1 μM) and bisindolylmaleimide (1 μM) also inhibited phenylephrine‐induced contractions.

Phenylephrine caused a concentration dependent increase in inositol phosphate production (EC50 119±67 nM). This response was blocked by terazosin (1 μM).

Phenylephrine caused the translocation of the PKC α isoform, but not the β, δ, γ, ε or λ isoforms, from the cytosolic to the particulate fraction of HCPSC, with an EC50 of 5.7±0.5 μM.

In FURA‐2AM (5 μM) loaded cells, phenylephrine elicited concentration dependent increases in [Ca2+]i, with an EC50 of 3.9±0.4 μM. The response to phenylephrine (10 μM) was blocked by prazosin (1 μM), bisindolymaleimide (1 μM), and nifedipine (10 μM).

In conclusion, this study has shown that HCPSC express functional α1‐adrenoceptors, and that the intracellular pathways responsible for contractility may be largely dependent upon protein kinase C activation and subsequent opening of L‐type calcium channels.

British Journal of Pharmacology (2003) 138, 218–224. doi:10.1038/sj.bjp.0705021
Activation and potentiation of the NO/cGMP pathway by NG‐hydroxyl‐L‐arginine in rabbit corpus cavernosum under normoxic and hypoxic conditions and ageing
Authors: Angulo Javier , Cuevas Pedro , Fernández Argentina , Gabancho Sonia , Allona Antonio , Martín‐Morales Antonio , Moncada Ignacio , Tejada Iñigo Sáenz de
Published: January 2003

When nitric oxide synthase (NOS) produces NO from NG‐hydroxy‐L‐arginine (OH‐arginine) instead of L‐arginine, the total requirement of molecular oxygen and NADPH to form NO is reduced. The aim of this work was to evaluate the effects of OH‐arginine on the contractility of rabbit corpus cavernosum (RCC) and to compare the capacities of L‐arginine and OH‐arginine to enhance NO‐mediated responses under normoxic and hypoxic conditions and in ageing, as models of defective NO production.

OH‐arginine, but not L‐arginine, was able to relax phenylephrine‐contracted rabbit trabecular smooth muscle. OH‐arginine‐induced relaxation was inhibited by the NOS‐inhibitor, L‐NNA (300 μM), and by the guanylyl cyclase inhibitor, ODQ (20 μM), while it was not affected by the cytochrome P450 oxygenase inhibitor, miconazole (0.1 mM). Administration of OH‐arginine, but not L‐arginine, produced a significant increment of cGMP accumulation in RCC tissue.

Relaxation elicited by OH‐arginine (300 μM) was still observed at low oxygen tension. The increase of cGMP levels induced by ACh (30 μM) in RCC was significantly enhanced by addition of OH‐arginine (300 μM) in normoxic conditions, as well as under hypoxia, while L‐arginine did not alter the effects of ACh on cGMP accumulation.

Endothelium‐dependent and nitrergic nerve‐mediated relaxations were both significantly reduced in RCC from aged animals (>20‐months‐old) when compared with young adult rabbits (5‐months‐old). Treatment with OH‐arginine (300 μM) significantly potentiated endothelium‐dependent and neurogenic relaxation in corpus cavernosum from aged rabbits, while L‐arginine (300 μM) did not have significant effects.

Results show that OH‐arginine promotes NO‐mediated relaxation of RCC and potentiates the NO‐mediated responses induced by stimulation of endogenous NO generation in hypoxic and aged tissues. We propose that the use of OH‐arginine could be of interest in the treatment of erectile dysfunction, at least in those secondary to defective NO production.

British Journal of Pharmacology (2003) 138, 63–70. doi:10.1038/sj.bjp.0705027
Ion-water interaction potentials in the semimicroscopic model
Authors: Dorman Vladimir L. , Jordan Peter C.
Published: January 2003

The semimicroscopic model separates the electronic and reorientational components of the solvent dielectric response. The former is accounted for by embedding the computational system in an electrical background that describes the high-frequency (optical) contributions to the dielectric constant (ε∼2). The latter is treated by means of the force field. We use this decomposition to describe the solvation of simple monovalent ions in water. The free energy of solvation is composed of two terms: one Born-like, describing the transfer of the ion from vacuum to the electrical background and the other describing the shielding free energy due to interaction between the ion and the surrounding solvent. We employ a highly simplified model: ions are hard spheres with crystal radii and water is a hard sphere with an embedded (gas-phase) multipole. Absolute ionic hydration energies cannot be directly measured. They hinge on the value accepted for the absolute potential of the standard hydrogen electrode. Using the most recent determination [M. D. Tissandier et al., J. Phys. Chem. A 102, 7787 (1998)] our description reproduces experimental hydration free energies using intuitively reasonable geometric parameters to describe water and the ions.
Gas-phase detection of the FCO2 radical by millimeter wave and high resolution infrared spectroscopy assisted by ab initio calculations
Authors: Zelinger Zdeněk , Dréan Pascal , Walters Adam , Moreno Juan Ramon Avilès , Bogey Marcel , Pernice Holger , von Ahsen Stefan , Willner Helge , Breidung Jürgen , Thiel Walter , Bürger Hans
Published: January 2003

Low pressure pyrolysis at 600 K of bis(fluoroformyl) peroxide, FC(O)OOC(O)F, yields the fluorocarboxyl radical, FCO2, in a concentration high enough to allow its detection by millimeter wave and infrared spectroscopy. The radical was first identified from its high resolution infrared spectrum obtained using a Fourier transform infrared interferometer. Observation and identification of its millimeter wave (MMW) spectrum were made possible by reliable ab initio calculations at the level of open-shell coupled cluster theory using large basis sets. The excellent agreement between the experimental and theoretical results confirms the structure of the FCO2 radical and the efficiency of the synthesis. The analysis of the MMW spectrum has given a set of ground state parameters including rotational, quartic centrifugal distortion, fine and hyperfine constants.
Electronic structure of para aminophenoxyl radical in water
Authors: Tripathi G. N. R.
Published: January 2003

The electronic structure of aqueous p-aminophenoxyl radical (H2NPhO•) has been examined by time-resolved resonance Raman spectroscopy and ab initio and density functional theories. The effects of hydrogen bonding and solvent reaction field on polarity of the radical have been visualized in terms of simple models. Calculations predict the dipole moment of the radical in its ground electronic state (2B1) to increase by 8(±2) D and the difference between the CN and CO bond lengths to decrease by ∼0.05 Å from gas phase to aqueous solution. This profound hydration effect converts the structure and chemical properties of H2NPhO• from a substituted phenoxyl radical in the gas phase to a semiquinone-like radical in water. The observation of vibrational modes enhanced in Raman by a non-Franck–Condon vibronic coupling mechanism has led to the identification of two very weakly absorbing electronic states of A22 symmetry in the 340–390 nm region, which borrow transition moment from close by strongly allowed electronic states of B12 symmetry at lower (∼440 nm) and higher (∼320 nm) energies. One of these transitions is parity forbidden (2B2g↔2B1g) in p-benzosemiquinone radical anion (PhO2−•) and p-phenylenediamine radical cation (Ph(NH2)2+•) and this is the first experimental evidence on energy location (3.44 eV) of this transition in an isoelectronic radical. The experiment and theory are combined to estimate the CO and CN bond lengths in H2NPhO• as ∼1.263 and ∼1.34 Å, respectively, in liquid water and ∼1.245 and ∼1.37 Å in the gas phase.
Interacting chain model for poly(ethylene glycol) from first principles—stretching of a single molecule using the transfer matrix approach
Authors: Livadaru L. , Netz R. R. , Kreuzer H. J.
Published: January 2003

Based on ab initio quantum-mechanical calculations on short segments (up to four subunits) of poly(ethylene glycol), we construct n-state interacting chain models with n=3 or 7 with nearest-neighbor interactions that also account fully for the geometrical structure of the molecule (bond lengths, bond angles, and dihedral angles). For chains up to N=21 subunits we construct, in the three-state model, all 3N conformers exactly. For longer chains we apply the transfer matrix method in the Gibbs ensemble in the presence of an external force. The force-extension curve is calculated with high accuracy by both methods, and the results are compared with each other and with experimental data. We show that the infinite chain length limit is reached at about N=200. We analyze the effect of variation of geometrical and energy parameters in the model, as well as the effect of chain length on our final results. Chain end distribution functions, probabilities of rotational states and the persistence length are calculated. We show that additional rotational states beyond those of the potential minima used in the rotational-isomeric-state approximation must be included for an accurate description.
Local hybrid functionals
Authors: Jaramillo Juanita , Scuseria Gustavo E. , Ernzerhof Matthias
Published: January 2003

We present a novel approach for constructing hybrid functionals by using a local mix of regular density functional theory (DFT) exchange and exact Hartree–Fock (HF) exchange. This local hybrid approach is computationally feasible for a wide range of molecules. In this work, the local mix of HF and DFT exchange is driven by the ratio of τW=|∇ρ|2/8ρ, the Weizsäcker kinetic energy density, with τ, the exact kinetic energy density. This particular choice of local mix yields 100% of exact exchange in one-electron regions. Dissociation energy curves, binding energies, and equilibrium geometries for two-center, three-electron symmetric radical cations can be modeled accurately using this scheme. We also report encouraging results for reaction energy barriers, and somewhat disappointing atomization energies for the small G2 set.
Binding energy, structure, and vibrational spectra of (HCl)2–6 and (HF)2–10 clusters by density functional theory
Authors: Guedes R. C. , do Couto P. C. , Costa Cabral B. J.
Published: January 2003

We are reporting density functional theory results for the binding energies, structures, and vibrational spectra of (H-Cl)2–6 and (H-F)2–10 clusters. The performance of different functionals has been investigated. The properties of HF clusters predicted by hybrid functionals are in good agreement with experimental information. The HCl dimer binding energy ΔEe is underestimated by hybrid functionals. The Perdew and Wang exchange and correlation functional (PW91) result for ΔEe is −9.6 kJ mol−1, in very good agreement with experiment (−9.5 kJ mol−1). However, PW91 overestimates binding energies of larger clusters. Hydrogen bonding cooperativity depends on the cluster size n but reaches a limit for moderately sized clusters (n=8 for HF). The average shift to low frequencies (Δν) of the X-H (X=Cl,F) stretching vibration relative to the monomer is in good agreement with experimental data for HF clusters in solid neon. However, some discrepancies with experimental results for HCl clusters were observed. The behavior of Δν as a function of the cluster size provides an interesting illustration of hydrogen-bond cooperative effects on the vibrational spectrum. The representation of the electronic density difference shows the rearrangement of the electronic density induced by hydrogen bonding in the clusters and supports the view that hydrogen-bond cooperativity is related to electronic sharing and delocalization.
Infrared cavity ringdown spectroscopy of acid–water clusters: HCl–H2O, DCl–D2O, and DCl–(D2O)2
Authors: Huneycutt Alex J. , Stickland Ross J. , Hellberg Fredrik , Saykally Richard J.
Published: January 2003

Infrared cavity ringdown laser absorption spectroscopy was used to characterize the gas-phase HCl and DCl stretch modes of three small acid–water clusters at 0.04 cm−1 resolution. The H35Cl stretch of HClH2O at 2723.1 cm−1 and the D35Cl stretch for DClD2O and DCl(D2O)2 were found to be at 1976.0 and 1796.7 cm−1, respectively. The spectral shifts with respect to the HCl and DCl monomers are consistent with theoretical predictions and matrix isolation work. Rotational structure was resolved for DClD2O and spectroscopic constants for both chlorine isotopomers were determined. The spectral shifts and band shapes were similar to those observed for the bonded OH stretch of pure water clusters. Cluster number densities (∼1×1012 cm−3) were slightly lower than found for the pure water clusters under similar conditions. Predissociation and IVR broadening in the acid–water clusters were determined to be qualitatively similar to the case of pure water and DF clusters.
Linear response functions for coupled cluster/molecular mechanics including polarization interactions
Authors: Kongsted Jacob , Osted Anders , Mikkelsen Kurt V. , Christiansen Ove
Published: January 2003

We present the first implementation of linear response theory for the coupled cluster/molecular mechanics (CC/MM) method. This model introduces polarization effects into a quantum mechanical/molecular mechanical (QM/MM) framework using a self-consistent procedure while electrostatic effects are modeled by assigning partial charges to the MM molecules and a van der Waals potential describes dispersion and short range repulsion. The quantum mechanical subsystem is described using coupled cluster electronic structure methods. The response theory for the calculation of molecular properties for such a model is described and implemented at the coupled cluster singles and doubles (CCSD) level. Sample calculations of excitation energies, transition moments and frequency dependent polarizabilities for liquid water are presented. Finally, we consider the development of a parameter independent iterative self-consistent CC/MM model where the properties calculated by CC/MM response theory are used in the QM/MM interaction Hamiltonian.
Can dendrimers be viewed as compact colloids? A simulation study of the fluctuations in a dendrimer of fourth generation
Authors: Harreis H. M. , Likos C. N. , Ballauff M.
Published: January 2003

By employing monomer-resolved Monte Carlo simulations, we analyze the conformations, density distributions, correlation functions, and the form factor of model dendrimers of fourth generation. We find that these objects are hybrids between polymer chains and compact colloidal particles, with the fluctuations of the monomers being correlated at length scales of the order of the bond length but practically uncorrelated for lengths exceeding this scale. We discuss the implications of this finding on the possibility of regarding dendrimers as “soft colloids,” on the detection of these fluctuations in scattering experiments and on the inversion of intensity profiles obtained in small-angle neutron scattering measurements.
Time delays in cold elastic scattering
Authors: Field David , Madsen Lars Bojer
Published: January 2003

Expressions are derived for time delays for elastic scattering in cold electron and cold atom collisions. Delays are found to occur in the femtosecond regime for virtual state electron scattering with CO2, using recent experimental data [Field et al., Phys. Rev. A 64, 22708 (2001)]. Delays associated with cold atom scattering may be of the order of 1 μs in the μK regime, using Li6 collisions as an example. The maximum theoretical time delay, obtained by magnetically tuning the scattering length, is found to have a universal value at any ultracold collision energy E, given by (2E)−1.