bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrophilic interaction liquid chromatography with tandem mass spectrometry for the determination of underivatized dencichine (β‐N‐oxalyl‐L‐α,β‐diaminopropionic acid) in Panax medicinal plant species
Authors: Koh Hwee‐Ling , Lau Aik‐Jiang , Chan Eric Chun‐Yong
Published: April 2005

Dencichine (β‐N‐oxalyl‐L‐α,β‐diaminopropionic acid) is a haemostatic agent present in important Chinese medicinal herbs such as Panax notoginseng, as well as other Panax species. It is also a reported neurotoxic agent found in Lathyrus sativus (grass pea seed). A selective analytical method incorporating hydrophilic interaction chromatography with positive electrospray ionization tandem mass spectrometry (HILIC/ESI‐MS/MS), for the analysis of dencichine in Panax plant species, was developed. Using multiple reaction monitoring (MRM) mode, underivatized dencichine, a small and highly polar compound, was selectively detected and quantified. The contents of dencichine in raw and steamed Panax notoginseng roots, 11 pairs of raw and steamed P. notoginseng herbal products, Panax ginseng roots, and Panax quinquefolium roots, were analyzed and compared. Optimal sensitivity of 0.3 ppm (detection limit) and 1.5 ppm (quantification limit) was achieved. The method was rapid (≤5 min), with the HILIC peak eluting at about 1 min. Steamed P. notoginseng samples were found to contain less dencichine than the corresponding raw samples, and there were also differences among the three Panax species; raw P. ginseng and P. quinquefolium contained less dencichine than the raw P. notoginseng species. This rapid and specific method may be applied to the quantification of dencichine in complex medicinal plants and their products. Copyright © 2005 John Wiley & Sons, Ltd.
Synthese und Struktur gemischtvalenter Galliumsubhalogenide: Molekulare, donorstabilisierte Ga5X7‐Spezies (X = Cl, Br)
Authors: Duan Taike , Stößer Gregor , Schnöckel Hansgeorg
Published: April 2005

Synthesis and Structure of mixed‐valent Gallium Subhalides: Molecular, donor‐stabilized Ga5X7 Species (X = Cl, Br)

Caused by partial disproportionation, metastable GaX‐solutions (X = Cl, Br) contain small amounts of GaX3 species. They react via insertion of GaX to Ga2X4 and Ga5X7 entities. In contrast to Ga2X4, only one example has been isolated so far for the latter one: [Ga5Cl7·5Et2O]. Variation of the preparation conditions (e.g. temperature, amount and kind of the donor molecule) now leads to 4 further Ga5X7 species. In three of those a centered Ga5 tetrahedron is icosahedrically (distorted) coordinated by 12 atoms (halogen atoms resp. atoms of the donor ligand). The principal importance of these Ga5X7 species especially for the disproportionation process is discussed.
Helical Bipyrazole Networks Conditioned by Hydrothermal Crystallization
Authors: Domasevitch Konstantin V. , Boldog Ishtvan , Rusanov Eduard B. , Hunger Jens , Blaurock Steffen , Schröder Martin , Sieler Joachim
Published: April 2005

Angular structure of 3,3′,5,5′‐tetramethyl‐4,4′‐bipyrazole tecton (Me4bpz) supports multiple helical strands in a series of coordination and hydrogen bonded polymers prepared using hydrothermal technique. Compounds reveal a variety of helical architectures and exist in the forms of double helicate Ag(Me4bpz)(PO2F2), two‐dimensional network formed by inter‐connection of the helices Ag2(Me4bpz)3(CF3CO2)2, interpenetrated two‐dimensional networks by interconnection of double helices Ag4(Me4bpz)5(NO3)4 · 2H2O and triple helicate formed by NH‒‒‒N hydrogen bonded bipyrazole molecules in structure Me4bpz·H2O.

Coordination polymers Ag(Me4bpz)X ((X = ClO4−, CF3SO3−, C2F5CO2−) adopt simpler chain‐like structure. In all coordination compounds the bipyrazole acts as a bridging neutral group and connects two silver atoms at the distances of 9.44–9.94Å.
Synthese und Kristallstruktur von heteronuklearen Metallkomplexen mit Nitridobrücken Re≡N‐Ni, Re≡N‐Pt, Os≡N‐Rh und Os≡N‐Ir
Authors: Morrogh Daniel , Galceran Mestres Montserrat , Niquet Elke , Barboza da Silva Carlos F. , Santos Saez Abel , Schwarz Simon , Strähle Joachim
Published: April 2005

Synthesis and Crystal Structure of Heteronuclear Metal Complexes with Nitrido Bridges Re≡N‐Ni, Re≡N‐Pt, Os≡N‐Rh, and Os≡N‐Ir

The heteronuclear complex [(Me2PhP)3Br2Re≡N‐NiBr2(OPMe2Ph)] (1) is obtained by the reaction of [ReNBr2(PMe2Ph)3] with NiBr2 in tetrahydrofuran in form of dark green, air sensitive crystals crystallizing in the monoclinic space group P21/n with a = 961.44(9), b = 3692.6(4), c = 1177.8(2) pm, β = 103.42(1)°, and Z = 4. In the dinuclear complex the complex fragment [NiBr2(OPMe2Ph)] is connected by an asymmetric nitrido bridge Re≡N‐Ni with the nitrido complex [ReNBr2(PMe2Ph)3], such that the Ni atom achieves a tetrahedral coordination. The nitrido bridge is characterized by a bond angle Re‐N‐Ni of 172.7(7)° and distances Re‐N = 169(1) and Ni‐N = 195.0(9) pm.

The reaction of [ReNCl2(PMe2Ph)3] with PtCl4 in THF proceeds under reduction of PtIV to yield air stable, brown crystals of [{(Me2PhP)3Cl2Re≡N}2PtCl2] (2) with the monoclinic space group P21/c and a = 1241.3(1), b = 1734.0(1), c = 1369.7(1) pm, β = 101.32(1)°, and Z = 2. The divalent Pt atom exhibits a square planar coordination with the two rhenium(V) nitrido complexes coordinated by nitrido bridges Re≡N‐Pt in trans position. The distances in the virtually linear nitrido bridge (Re‐N‐Pt = 174.0(3)°) are Re‐N = 170.6(5) pm and Pt‐N = 196.4(5) pm.

The nitrido complex [OsNCl3(AsPh3)2] reacts with [Rh(μ‐Cl)(COD)]2 in CH2Cl2 to yield [(Ph3As)2Cl3Os≡N‐RhCl(COD)] (3). The heterometallic complex forms olive green, largely air stable crystals with the monoclinic space group Cc and a = 2316.8(5), b = 1169.3(1), c = 1601.4(2) pm, β = 106.12(1)°, and Z = 4. Rh(I) exhibits a square‐planar coordination with the two π bonds of the COD ligand coordinating in cis position. The osmium nitrido complex is coordinated by a linear nitrido bridge Os≡N‐Rh (Os‐N‐Rh = 176.1(7)°) with distances Os‐N = 168(1) pm and Rh‐N = 186(1) pm.

The complex [(Ph3As)2Cl3Os≡N‐IrCl(COD)] (4) is obtained by the reaction of [Ir(μ‐Cl)(COD)]2 with [OsNCl3(AsPh3)2] in CH2Cl2. 4 crystallizes isotypic to 3 in form of olive brown blocks with the space group Cc and a = 2322.1(2), b = 1167.01(6), c = 1603.8(2) pm, β = 105.927(9)°, and Z = 4. The nitrido bridge Os≡N‐Ir is characterized by the bond angle Os‐N‐Ir = 176.2(8)° and distances Os‐N = 171.2(8) pm and Ir‐N = 181.5(8) pm.
Na2[B18Se16]: The First 3D Polymeric Selenoborato‐closo‐dodecaborate
Authors: Hammerschmidt A. , Döch M. , Pütz S. , Krebs B.
Published: April 2005

Systematic studies on selenoborates containing a B12 cluster entity and alkali metal cations led to the new crystalline phase Na2[B18Se16] which consists of a icosahedral B12 cluster completely saturated with trigonal‐planar BSe3 units and sodium counter‐ions. The cluster entities are connected to each other via seleno‐ and perselenobridges. Thus a three‐dimensional network results with [(B18Se12Se6/2)n]2−‐ and [(B18Se15Se6/2)n]2− anions in a ratio of 2:1. The new chalcogenoborate was prepared in a solid state reaction from sodium selenide, amorphous boron and selenium in evacuated carbon coated silica tubes at a temperature of 850 °C. Na2[B18Se16] crystallizes in the trigonal space group ${\rm P}{\bar 3}$ (no. 147) with a = 17.021(1) Å, c = 8.903(1) Å and Z = 3.
Ternary Rare Earth Platinum Germanides RE2Pt9Ge3 (RE = Y, Tb–Lu) Crystallizing with a Monoclinic Structure Closely Related to Orthorhombic Y2Co3Ga9
Authors: Prots Yurii , Borrmann Horst , Schnelle Walter , Jeitschko Wolfgang
Published: April 2005

A new series of isotypic germanides RE2Pt9Ge3 (RE = Y, Tb‐Lu) was prepared by arc‐melting of the elemental components or in the case of the ytterbium compound via induction heating in a high‐frequency furnace. Subsequently, all samples were annealed at temperatures between 900 and 1000 °C. The investigated germanides crystallize in a new monoclinic structure type which for Tb2Pt9Ge3 was determined from single‐crystal X‐ray data: C2/c (no. 15), mC56, Z = 4, a = 13.373(1) Å, b = 7.742(1) Å, c = 10.029(1) Å, β = 116.73(1)°, RF = 0.030 for 973 structure factors and 67 variable parameters. The structures of Dy2Pt9Ge3 (a = 13.346(1) Å, b = 7.735(1) Å, c = 10.015(1) Å, β = 116.72(1)°, RF = 0.039, 1240 F's, 67 variables) and Ho2Pt9Ge3 (a = 13.332(1) Å, b = 7.723(1) Å, c = 9.999(1) Å, β = 116.67(1)°, RF = 0.047, 864 F's, 67 variables) were refined from single‐crystal data, too. The structure may be described as an ABAB stacking of two different pseudo‐trigonal layers with compositions RE2Pt3 (designated A) and Pt2Ge (designated B). Layers B may be considered as distorted hexagonal close packed, similar to a compression of three adjacent layers I–Cd–I of the CdI2 type structure. Structural relationships among the structures of Tb2Pt9Ge3, Y2Co3Ga9, Yb2Pd3Ga9, Er4Pt9Al24, Sc1.2Fe4Si9.8, and ErNi3Al9 are discussed. The temperature dependence of magnetic susceptibility, electrical resistivity, and specific heat capacity of the compounds RE2Pt9Ge3 (RE = Y, Tb‐Er, Yb, Lu) were investigated. All of them are metallic conductors. Y2Pt9Ge3 and Lu2Pt9Ge3 are Pauli paramagnets, while the others show Curie paramagnetic behavior with antiferromagnetic ordering temperatures of 5 K (for the Dy compound) or less. Ytterbium in Yb2Pt9Ge3 takes the trivalent oxidation state. Thermodynamic standard values at 298.15 K are derived and crystal electric field contributions are discussed.
Tieftemperaturuntersuchungen von Wasserstoffbrückenbindungen in den Hydroxiden β‐Be(OH)2 und ε‐Zn(OH)2 mit Raman‐Spektroskopie sowie Röntgen‐ und Neutronenbeugung
Authors: Jacobs Herbert , Niemann Anke , Kockelmann Winfried
Published: April 2005

Low Temperature Investigations of Hydrogen Bridge Bonds in the Hydroxides β‐Be(OH)2 and ε‐Zn(OH)2 by Raman‐Spectroscopy as well as X‐Ray and Neutron Diffraction

Fully and partially deuterated samples of β‐Be(OH)2 and ε‐Zn(OH)2 were investigated by Raman‐spectroscopy in the temperature range from ∼ 10 K to ∼ 300 K. X‐ray and neutron diffraction data from 5 K to 245 K were evaluated for β‐Be(OD)2 on powder samples. Neutron diffraction on ε‐Zn(OD)2 was carried out between 5 K and 298 K. Within these temperature regions the two hydroxides crystallize isotypic with orthorhombic symmetry, space group P212121 with Z = 4.

The Raman‐spectra of β‐Be(OH)2 show an unexpected and until now not understood effect: with decreasing temperatures beginning at ∼ 40 K the stretching modes of the two crystallograpically inequivalent hydroxide ions connected by hydrogen bridgebonds shift to higher wave numbers. For ε‐Zn(OH)2 this inversion occurs already at 50 K and the effect is markedly stronger.
Effects of Sensor Errors on the Performance of Map Matching
Authors: Chen Wu , Li Zhilin , Yu Meng , Chen Yongqi
Published: April 2005

Map matching has been widely applied in car navigation systems as an efficient method to display the location of vehicles on maps. Various map-matching algorithms have been proposed. Inevitably, the correctness of the map matching is closely related to the accuracy of positioning sensors, such as GPS or Dead Reckoning (DR), and the complexity of the road network and map, especially in urban areas where the GPS signal may be constantly blocked by buildings and the road network is complicated. The existing map matching algorithms cannot resolve the positioning problems under all circumstances. They sometimes give the wrong position estimates of the car on road; the result is called mismatching. In order to improve the quality of map matching, a deep understand of the accuracy of sensor errors on mismatching is important. This paper analyses various factors that may affect the quality of map matching based on extensive tests in Hong Kong. Suggestions to improve the success rate of map matching are also provided.
What is the accuracy of DGPS?
Authors: Monteiro Luís Sardinha , Moore Terry , Hill Chris
Published: April 2005

In general, a Reference Station calculates differential corrections which are valid for that exact location (zero baseline) at that particular epoch (age of corrections zero). However, DGPS users may be located as far as 200 nm away from the Reference Station and some of the errors compensated for by the Reference Station vary with space, namely satellite ephemeris, tropospheric and ionospheric errors. Therefore, the corrections calculated at the Reference Station suffer certain accuracy degradation as the separation distance increases, because of a decreasing relevance of the Reference Station data to the user. The error growth with increasing distance to the beacon is accentuated by the inability of Reference Station and user to see the same satellites, commonly termed the lack of intervisibility. The error growth with distance is the most important factor determining DGPS accuracy, but surprisingly very little has been done to assess it. US official documents and IALA state that the achievable accuracy degrades at an approximate rate of 1 m for each 150 km (80 nm) distance from the broadcast site, but this value is based on a theoretical prediction, made back in 1993. To estimate the error growth with real data, 6 DGPS receivers were placed along the Portuguese coastline at approximately 50 nm intervals from Sagres Broadcast Station, in a South – North direction. This paper describes the results of the trial.
Airborne Law Enforcement – Fighting Crime From The Air
Authors: Cowan James A.
Published: April 2005

This paper reviews the use of the air for the police in their operations to fight crime throughout the UK. There is a description of the job of the aircrew, the role and navigation systems and the aircraft used in daily operations. There is an examination of the use of both the helicopter and fixed wing aircraft concentrating on their suitability for police operations in which the weather and cost constraints are seen to be major factors to be considered in striking the balance to obtain the best effectiveness.
AIS at the Front Line The View from the Bridge “One Year On”
Authors: Hadnett Edmund
Published: April 2005

This paper was the basis of a presentation given on 9 November 2004 at Church House, London during the Institute's NAV 04 Conference. The author argues that AIS has been proven as a valuable aid to safe navigation, but requires comprehensive training to ensure its proper and effective use. Furthermore, he supports those concerned that using AIS in support of “homeland security” will make ships more vulnerable to attack.
Intravascular ultrasonic assessment of post-operative remodelling of aortic coarctation repaired by use of a subclavian flap
Authors: Shimizu Takashi , Satomi Gengi , Yasukochi Satoshi
Published: April 2005

Background:We have used intravascular ultrasound in an attempt to clarify the extent of vascular remodelling of the aortic arch after the repair of aortic coarctation by use of a subclavian flap.Methods:We investigated 13 patients with coarctation of the aorta, ranging in age from 1.4 to 43.0 months, with a mean of 20.8 months, who underwent aortoplasty by incorporation of a subclavian flap. The mean postoperative period was 19.6 months, with a range from 0.03 to 41.2 months. The luminal morphology of the aortic arch was evaluated by intravascular ultrasound at the time of post-operative catheterization.Results:We observed 3 cases longitudinally. Over the period of observation, we found three types of morphology of the aorta at the site of incorporation of the subclavian flap, namely a snowman shape with two inflection points, a pisiform shape with one inflection point, and a round shape without any points of inflection. There was a correlation between the cross-sectional shapes at the site of the subclavian flap in the postoperative period (p < 0.01). In each case, we measured the cross-sectional area at the site of subclavian flap, at the descending aorta, and at the distal aortic arch. The cross-sectional area, and the increment of the cross-sectional area at the site of subclavian flap, was larger.Conclusion:The shape of the lumen subsequent to repair of aortic coarctation changes progressively from a snowman, to a pisiform, and finally to a round shape. Greater growth of the subclavian flap compared to the native wall of the aorta was observed for at least the first 4 years after repair. This finding may improve our understanding of the remodelling process of the arterial trunks after surgical repair.
Echocardiographic presentations of endocarditis, and risk factors for rupture of a sinus of Valsalva in childhood
Authors: McMahon Colin J. , Ayres Nancy , Pignatelli Ricardo H. , Franklin Wayne , Vargo Thomas A. , Bricker J. Timothy , El-Said Howaida G.
Published: April 2005

Background: In recent years, the diagnosis of infective endocarditis has been enhanced by the use of echocardiography. We sought, therefore, to review its effect on the management of endocarditis in children. Methods: We reviewed all the patients presenting to our institution for evaluation for infective endocarditis from May 1994 to January 2002. The patients were stratified according to whether or not they had congenitally malformed hearts. Results: Of the 90 referred patients identified, 46 (51%) had positive ultrasonic findings. Of these, we excluded 26 patients because of the presence of indwelling lines. The remaining 20 patients with features of endocarditis had a median age of 6.5 years, and a range from 0.14 to 8.5 years. There were 4 patients with normal hearts, and 16 with congenital cardiac malformations. We identified rupture of a sinus of Valsalva in four patients, with rupture into the left ventricle in two, and into the right ventricle and right atrium in one each. The mitral valve was involved in six patients, the aortic valve in another six, including all four with rupture of the sinus of Valsalva, both mitral and aortic valves in three, the pulmonary trunk in three patients, and the tricuspid valve and a Blalock-Taussig shunt in one patient each. Organisms isolated included Streptococcus mitis in 4 patients, Streptococcus pneumoniae in 2 patients, Streptococcus sanguis in 1, Staphylococcus aureus in 3, Staphylococcus epidermidis in 1, and Enteroccocus in 2. Cultures proved negative in 7 patients. Surgical intervention was needed in 12 patients, and one died (5%). Only the left-sided chambers were involved in those with normal hearts. Both patients infected with Streptococcus pneumoniae had rupture of a sinus of Valsalva. Conclusion: Involvement of the left-sided chambers is more likely in structurally normal hearts, and in cases with rupture of a sinus of Valsalva, in which case infection with Streptococcus pneumonia should be suspected.
Last Glacial Maximum in South America: Paleoclimate proxies and model results
Authors: Wainer Ilana , Clauzet Gabriel , Ledru Marie‐Pierre , Brady Esther , Otto‐Bliesner Bette
Published: April 2005

Observations in South America based on paleoenvironmental data for the Last Glacial Maximum (LGM) that shows a generally lower temperatures and reduced precipitation of the region are compared to simulation results from the paleoclimate version of the National Center for Atmospheric Research coupled climate system model. Analyses of the LGM wind simulation for the tropical Atlantic show that the convergence zone does not extend all the way into South American continent during the Austral summer. This would have prevented moisture inflow into the adjacent continental area of equatorial northeastern Brazil. Interpretations of paleoclimate proxy records from this region are consistent with this scenario. In the subtropics, LGM westerlies were weaker and data show characteristics of more humid conditions. At higher latitudes model simulations suggest intensification of the westerlies which, in combination with colder sea surface temperatures would imply less moisture influx into the South American continent from the Atlantic sector. Low lake levels in high southern latitudes and general aridity would support the model findings.
A framework for inferring field‐scale rock physics relationships through numerical simulation
Authors: Moysey Stephen , Singha Kamini , Knight Rosemary
Published: April 2005

Rock physics attempts to relate the geophysical response of a rock to geologic properties of interest, such as porosity, lithology, and fluid content. The geophysical properties estimated by field‐scale surveys, however, are impacted by additional factors, such as complex averaging of heterogeneity at the scale of the survey and artifacts introduced through data inversion, that are not addressed by traditional approaches to rock physics. We account for these field‐scale factors by creating numerical analogs to geophysical surveys via Monte Carlo simulation. The analogs are used to develop field‐scale rock physics relationships that are appropriate for transforming the geophysical properties estimated from a survey into geologic properties. We demonstrate the technique using a synthetic example where radar tomography is used to estimate water content.
Generation of Alfvén waves by high power pulse at the electron plasma frequency
Authors: Van Compernolle B. , Gekelman W. , Pribyl P. , Carter T. A.
Published: April 2005

The interaction of a short high power pulse at the electron plasma frequency (f = 9 GHz, τ = .5 μs, P < 70 kW) and a magnetized plasma (n0 ≤ 1.25 · 1012 cm−3, B0 = 1.0 − 2.5 kG, Helium) capable of supporting Alfvén waves has been studied. The interaction leads to the generation of inertial shear Alfvén waves. The Alfvén waves are centered in an azimuthal layer corresponding to the location of the plasma frequency cutoff. The Alfvén waves are monochromatic with frequency within 10% of the ion cyclotron frequency. Spatial patterns of the wave were measured at different axial and radial locations.
Central and peripheral components of the pressor effect of anandamide in urethane‐anaesthetized rats
Authors: Kwolek Grzegorz , Zakrzeska Agnieszka , Schlicker Eberhard , Göthert Manfred , Godlewski Grzegorz , Malinowska Barbara
Published: April 2005

We wanted to search for the mechanism(s) responsible for the brief pressor response induced by anandamide in urethane‐anaesthetized rats.

The anandamide‐induced pressor effect was not modified by the antagonists of cannabinoid CB1 and vanilloid TRPV1 receptors, SR 141716A (3 μmol kg−1) and capsazepine (1 μmol kg−1), respectively, by bilateral vagotomy and by pithing. Replacement of urethane by pentobarbitone virtually abolished the pressor effect of anandamide, both in pithed and vagotomized and in ‘intact’ rats (i.e. not treated in this manner).

The pressor effect of anandamide was reduced by the nonselective TRPV family inhibitor ruthenium red (3 μmol kg−1) and by the blocker of L‐type calcium channels nifedipine (1 μmol kg−1), both in pithed urethane‐anaesthetized rats and in ‘intact’ urethane‐anaesthetized rats. The nonselective β‐adrenoceptor antagonist propranolol (0.1 or 0.3 μmol kg−1) and the nonselective NMDA receptor antagonist MK‐801 (1 μmol kg−1) diminished the anandamide‐induced vasopressor response in ‘intact’ but not in pithed rats. The inhibitory effect of propranolol in ‘intact’ rats was mimicked by the β2‐adrenoceptor antagonist ICI 118551 (1 μmol kg−1), but not by the β1‐adrenoceptor antagonist CGP 20712 (1 μmol kg−1).

The present study revealed that two mechanisms may be responsible for the anandamide‐induced pressor response in urethane‐anaesthetized rats. The first involves the central nervous system (probably the medulla oblongata) and is sensitive to propranolol and MK‐801. The second, which is located peripherally (most probably in blood vessels), is sensitive to nifedipine, ruthenium red and pentobarbitone and, hence, probably represents a Ca2+‐dependent mode of action.

British Journal of Pharmacology (2005) 145, 567–575. doi:10.1038/sj.bjp.0706195
Effect of galantamine on the human α7 neuronal nicotinic acetylcholine receptor, the Torpedo nicotinic acetylcholine receptor and spontaneous cholinergic synaptic activity
Authors: Texidó Laura , Ros Esteve , Martín‐Satué Mireia , López Susana , Aleu Jordi , Marsal Jordi , Solsona Carles
Published: April 2005

Various types of anticholinesterasic agents have been used to improve the daily activities of Alzheimer's disease patients. It was recently demonstrated that Galantamine, described as a molecule with anticholinesterasic properties, is also an allosteric enhancer of human α4β2 neuronal nicotinic receptor activity. We explored its effect on the human α7 neuronal nicotinic acetylcholine receptor (nAChR) expressed in Xenopus oocytes.

Galantamine, at a concentration of 0.1 μM, increased the amplitude of acetylcholine (ACh)‐induced ion currents in the human α7 nAChR expressed in Xenopus oocytes, but caused inhibition at higher concentrations. The maximum effect of galantamine, an increase of 22% in the amplitude of ACh‐induced currents, was observed at a concentration of 250 μM Ach.

The same enhancing effect was obtained in oocytes transplanted with Torpedo nicotinic acetylcholine receptor (AChR) isolated from the electric organ, but in this case the optimal concentration of galantamine was 1 μM. In this case, the maximum effect of galantamine, an increase of 35% in the amplitude of ACh‐induced currents, occurred at a concentration of 50 μM ACh.

Galantamine affects not only the activity of post‐synaptic receptors but also the activity of nerve terminals. At a concentration of 1 μM, quantal spontaneous events, recorded in a cholinergic synapse, increased their amplitude, an effect which was independent of the anticholinesterasic activity associated with this compound. The anticholinesterasic effect was recorded in preparations treated with a galantamine concentration of 10 μM.

In conclusion, our results show that galantamine enhances human α7 neuronal nicotinic ACh receptor activity. It also enhances muscular AChRs and the size of spontaneous cholinergic synaptic events. However, only a very narrow range of galantamine concentrations can be used for enhancing effects.

British Journal of Pharmacology (2005) 145, 672–678. doi:10.1038/sj.bjp.0706221
Phase behavior of self-associating fluids with weaker dispersion interactions between bonded particles
Authors: Talanquer V.
Published: April 2005

In this study, we explore the global phase behavior of a simple model for self-associating fluids where association reduces the strength of the dispersion interactions between bonded particles. Recent research shows that this type of behavior likely explains the thermodynamic properties of strongly polar fluids and certain micellar solutions. Based on Wertheim’s theory of associating liquids [M. S. Wertheim, J. Stat. Phys. 42, 459 (1986); 42, 477 (1986)], our model takes into account the effect that dissimilar particle interactions have on the equilibrium constant for self-association in the system. We find that weaker interactions between bonded molecules tend to favor the dissociation of chains at any temperature and density. This effect stabilizes a monomeric liquid phase at high densities, enriching the global phase behavior of the system. In particular, for systems in which the energy of mixing between bonded and unbonded species is positive, we find a triple point involving a vapor, a dense phase of chain aggregates, and a monomeric liquid. Phase coexistence between the vapor and the monomeric fluid is always more stable at temperatures above the triple point, but a highly associated fluid may exist as a metastable phase under these conditions. The presence of this metastable phase may explain the characteristic nucleation behavior of the liquid phase in strongly dipolar fluids.
Probing the ultrafast nuclear motion in CS22+ in intense laser fields
Authors: Hishikawa Akiyoshi , Ueyama Masakuni , Yamanouchi Kaoru
Published: April 2005

The temporal evolution of the nuclear wave packet of CS22+ formed in an intense laser field (60 fs, 0.13PW∕cm2) is traced in real time by the pump-and-probe technique combined with coincidence momentum imaging of the Coulomb explosion process, CS23+→S++C++S+. The momentum correlations among the fragment ions obtained as a function of the pump–probe time delay between 133 fs to 3 ps reveal that the nuclear wave packet in CS22+ evolves not only along the anti-symmetric stretching coordinate to yield S+ and CS+ but also along the symmetric stretching coordinate leading to the simultaneous breaking of the two C-S bonds. The contribution from two different electronic states having bent and linear-type geometrical configurations is identified in the wave packet motion along the bending coordinate of CS22+.
Improved visible photoluminescence from porous silicon with surface Si–Ag bonds
Authors: Sun J. , Lu Y. W. , Du X. W. , Kulinich S. A.
Published: April 2005

Porous silicon with surface Si–Ag bonds was prepared by a two-step method combining chemical etching and electrochemical anodization. The microstructure was analyzed by scanning electron microscopy, and the bond structure was evaluated by energy dispersion spectroscopy and Fourier transform infrared spectroscopy. The material prepared by this technique gives strong photoluminescence with improved photostability. The improvements in properties are attributed to the existence of the surface Si–Ag bonds, which are more stable compared to Si–H bonds usually observed in convenient porous silicon fabricated by electrochemical anodization.
Report on the Charleston Conference
Authors: Cassell Kay Ann
Published: April 2005

Purpose

To report on the annual Charleston Conference, held November 3‐6, 2004 in Charleston, South Carolina.

Design/methodology/approach

A summary of the main points of the conference.

Findings

Addresses questions and topics such as: how useful core book lists can be in 2004; new publishing models; a study of circulation data, ILL requests and WorldCat holdings of University of Colorado monographs; whether there is still funding for electronic full‐text resources in the humanities and fine arts; the usage of print journals in the electronic age; citation data in the sciences regarding books; and the e‐journal project at Drexel.

Originality/value

This report is of interest to library and information management professionals.
A template for shareholder value creation on M&As
Authors: MacDonald Randy
Published: April 2005

Purpose

To provide a template for creating shareholder value through successful mergers and acquisitions (M&A) practices.

Design/methodology/approach

Taking as an example the merger between Ameritrade Holding Corporation and Datek Online Holdings Corp. in 2002, this paper provides a template for clearly and transparently communicating with shareholders and potential shareholders the value creation so the company can get credit for its M&A success in its stock price.

Findings

Outlining a template can create consistency, discipline and transparency around the creation of shareholder value during M&As.

Originality/Value

Other publications have documented reasons why M&As fail including: companies overpaying, the integration failing to overcome cultural conflicts, poor integration processes being used, resource constraints, etc. This article doesn't cover that. This article walks through a simple template for companies to follow when measuring shareholder value creation from a M&A.

Originality/value

It is more than just the fact that most M&As fail to realize the promised value. To be successful, deal makers must have a simple, transparent and disciplined approach to measuring the shareholder value creation. This paper offers guidelines for this approach.
Building surveyors and adjudication: the implications of Hurst Stores v. M L Europe Property Limited (2004)
Authors: Donohoe Stephen
Published: April 2005

Purpose

To consider the recent decision by the Court of Appeal in the case of Hurst Stores v. M L Europe Property Ltd (2004) and the possible important implications for building surveyors and other construction professionals.

Design/methodology/approach

A review of literature and case law. Possible developments in this area of law are considered.

Findings

A person described as a “project manager” does not necessarily have authority to make legally binding agreements. Where a building surveyor is acting as a project manager, the extent of authority ought to be clarified, preferably in writing. Where a building surveyor is dealing or negotiating with a project manager, he/she cannot take it for granted that any agreement reached will be legally binding. Furthermore, as a consequence of the decision in the Court of Appeal, a document with the heading “Final Account” might not be a final account at all!

Research implications

Increasingly, building surveyors are involved in adjudication, either as witnesses or as adjudicators. In the latter case, the building surveyor ought to be aware that as a result of this case, the probability of a legal challenge to an adjudicator's decision is greatly increased. Another consequence of cases such as Hurst means that building surveyors are more likely rather than less likely to be involved in adjudication if they are operating in the UK.

Originality/value

Applies recent case law to the work of building surveyors.
Creating value for channel partners: the Cervena case
Authors: Beverland Michael
Published: April 2005

Purpose

Aims to report on the approach used by the New Zealand Game Industry Board (NZGIB) to create a competitive advantage with channel buyers in the USA. This examination is in response to calls for research on international marketing strategy implementation in business markets. The NZGIB developed an innovative marketing program labeled “Cervena” to reposition commodity venison as an up‐market product sold through specialist restaurants.

Design/methodology/approach

An in‐depth case study of the Cervena approach was conducted. Data were gained through in‐depth interviews with key marketing staff. Interviews were supplemented with secondary data.

Findings

The findings identified the synergistic relationships between demand chain partners and end consumers. Tacit competitive advantages were built by adapting to channel requirements, leveraging established relationships, and drawing on aspirational imagery at the consumer level. Critically, no one part of the program could operate in isolation. Implementing such a strategy was difficult because of the failure to convert transactional relationships between farmers and their buyers into long‐term ones that provided greater certainty of supply and pricing. This illustrates both the benefits of networks and the need to adapt the implementation effort over time to ensure ongoing commitment to the relationship, and high quality market‐oriented outcomes.

Originality/value

This article provides a rare glimpse into international strategy implementation in industrial networks and suggests that such success will be contingent on initial strategic choices, adaptability, and supportive policies that reinforce market‐oriented values. Managers need to ensure adaptability within a relationship or network structure in order to consolidate initial competitive advantages and ensure ongoing buyer commitment.
Job‐related stress and social support in kindergarten principals: the case of Macau
Authors: Sai Wong Kwok , Hing Cheuk Wai
Published: April 2005

Purpose

One objective of the present study was to explore how stressful kindergarten principals, as leaders and managers of their schools, found their work to be, and if such job‐related stress was associated with negative emotions and job (dis)satisfaction. Another objective was to assess whether or not social support from one's supervisor could reduce the adverse effects of job‐related stress. A related objective was to examine possible negative impacts associated with receipt of support from one's supervisor.

Design/methodology/approach

A total of 44 kindergarten principals in Macau filled out a questionnaire that contained the variables of interest.

Findings

The results indicated that the principals found their work to be moderately stressful; only emotional support was shown to be effective in buffering the impacts of job‐related stress; and there were only weak adverse effects related to the receipt of support.

Originality/value

This paper is useful in understanding the relationship of stress to work in the school environment.
Introduction: toward understanding e‐business transformation
Authors: Gale Jeffrey , Abraham Dolphy
Published: April 2005

Purpose

To introduce the special issue on organizational transformation and e‐business implementation.

Design/methodology/approach

Provides a brief review of the papers within the issue.

Findings

The organization transformation brought on by the internet and the adoption of e‐business approaches are fertile ground for continuing work. Virtually, all aspects of the structure and process within the organization are affected.

Originality/value

Provides a summary of the perspectives considered within the issue.
The impact of structuring characteristics on the launching of virtual communities of practice
Authors: Dubé Line , Bourhis Anne , Jacob Réal
Published: April 2005

Purpose

Despite the increasing popularity of virtual communities of practice (VCoPs), our understanding of how to intentionally form, develop and sustain them is still at an embryonic stage. Aims to go some way to remedying this.

Design/methodology/approach

Investigates the attempt by 14 organizations to implement 18 VCoPs. Using existing documents, detailed logs, and focus groups, a large quantity of qualitative data was gathered, coded, and analyzed.

Findings

The study shows that the environment, the relevance of the VCoP's objectives to its members' daily work, and the degree to which the VCoP is embedded in the organizational structure of an organization are the three structuring characteristics most likely to explain the success or failure of a VCoP at the launching stage.

Research limitations/implications

The focus is limited to the launching phase; further research should investigate different stages of development.

Practical implications

The results may offer an indication as to the most important characteristics to consider at the launching stage of a VCoP. Management may want to work at changing the characteristics or take actions to counteract their obstructive effects.

Originality/value

This paper highlights the need for a contingency approach in VCoPs research and practice, and rids one of the misconception, which is pervasive in the extant literature, that all VCoPs are the same and should be managed the same way.
E‐commerce in Hong Kong: an empirical perspective and analysis
Authors: Gunasekaran A. , Ngai E.W.T.
Published: April 2005

Purpose

The main objective of this study is to develop a framework for: identifying the reasons for using e‐commerce; understanding the implications of e‐commerce in companies; and implementing and applying e‐commerce successfully for improved organizational competitiveness and success.

Design/methodology/approach

A structured questionnaire was designed, pre‐tested, modified, and used to capture data on e‐commerce in Hong Kong. Based on the feedback from the pilot‐test, the questionnaire was modified and a final questionnaire was developed and mailed to companies in Hong Kong. In the survey, conducted with Hong Kong companies, the perceived benefits and perceived barriers of e‐commerce implementation are discussed.

Findings

The conceptual model based on the analysis of literature and some reported case experiences is developed using the current issues that have been highlighted as important e‐commerce success factors of implementation. The major factors that influence the application and implementation of e‐commerce are: perceived usefulness of web; perceived barriers of the internet for e‐commerce; usage of the internet; and perceived benefits of the internet for e‐commerce. In addition to this, country‐specific factors such as culture, technology competency, government policy, educational level, influence the level of application of e‐commerce.

Practical implications

The framework is the result of the validation of the theoretical model, together with the conclusions of the empirical analysis conducted in Hong Kong. The empirical analysis supported some of the assumptions of the theoretical model, whereas others were not supported. Based on the feedback received from respondents, the model has been revised to reflect these practical considerations.

Originality/value

Little research has been done to address the perceived benefits and potential barriers to e‐commerce implementation in Hong Kong. This study is a timely and important one in that examines the current status of e‐commerce implementation in Hong Kong. A generic framework is presented with the objective of supporting the application and implementation of the internet for e‐commerce.
Allozyme variation of African and Iberian populations of the genus Cobitis
Authors: Perdices A. , Machordom A. , Doadrio I.
Published: April 2005

African and Iberian populations of the genus Cobitis exhibit high morphological polymorphism and their taxonomy is unclear. In seven such populations the percentage of polymorphic loci ranged between _P=0.08–0.48 and mean heterozygosity per locus H=0.005–0.073. The lowest Nei genetic distance between African and Iberian populations of Cobitis was D=0.250. The populations separated with the formation of the Gibraltar strait 5 million years ago. C. calderoni is a well‐differentiated branch from the rest of the Iberian populations of the genus. Our analysis supports the concept that C. paludica populations and C. maroccana are referable to the subgenus Iberocobitis. These African and Iberian populations represent two taxa, C. maroccana Pellegrin, 1929 and C. paludica De Buen, 1930. C. maroccana and C. paludica populations are monophyletic and the African population is the most differentiated genetically. The Arrago population of C. paludica is genetically the most differentiated of the Iberian populations. Our allozyme data do not support the previous consideration of the Albufera lagoon population as a different species from C. paludica.
Quantitative Characterization of the Fracture Surface of Si Single Crystals by Confocal Microscopy
Authors: Xin Yun‐Biao , Hsia K. Jimmy , Lange David A.
Published: April 2005

Experiments are conducted to study the dislocation nucleation conditions at the crack tip in {110}〈110〉 oriented Si single crystals. Specimens with surface cracks are first statically loaded at elevated temperatures for a prolonged period of time to initiate and move dislocations away from the crack tip, then cooled down to room temperature and loaded to fracture to measure the fracture toughness. Fractographic analysis of the fracture surfaces is performed. Distinct wavy patterns on the fracture surface at the initial cleavage crack front are observed, which is attributed to the existence of local mixed mode I/mode III stresses resulting from the inhomogeneous dislocation activity. Confocal microscopy is employed to quantify the fracture surface roughness. The results show that the increase of fracture toughness is directly associated with the increased area of the rough surface, which is characterized by the roughness number or the fractal dimension increment. Our results also demonstrate that dislocation nucleation can occur only at discrete sites. The spacing between these dislocation nucleation sources is of the order of 1 μm. A simple model is developed for the relationship between the fracture toughness and the surface roughness parameters, which is in good agreement with the experimental results.
Residual Stresses in Unidirectional Composites with Closely Spaced Fibers
Authors: Kouris Demitris , Meisner Mark
Published: April 2005

Many of the composites utilized in current applications are consolidated at high temperatures. After cooldown to room temperature, the differences in the expansions of the constituent materials may lead to very high residual stresses. Since failure is driven by critical rather than average states, the local stress field becomes essential in evaluating any composite before it is tested under service conditions. The present study describes an analytical solution for the local residual field of a composite with fibers that are closely spaced. The geometry under consideration involves three fibers with their centers located at the vertices of an equilateral triangle. This arrangement corresponds to the generic element of the hexagonal array, an arguably natural fiber distribution. It was found that when the interfaces are perfectly bonded and the three fibers are very close to each other, tensile radial stresses may develop in the constrained matrix region. The analysis can be generalized for any number of fibers at the vertices of a regular polygon.
Density of xNa2S.(1 – x)B2S3 (x = 0 to 0.8) Glasses: Correlation with Short‐Range Order
Authors: Martin Steve W. , Cho Jaephil , Polewik Tamara , Bhowmik Siddhartha
Published: April 2005

The densities of xNa2S + (1 – x)B2S3 glasses have been measured for 0 ≤x≤ 0.80. The variation of the density with x is quite strong and is characterized by a sharp maximum at x∼0.30. The density increases on the low‐alkali side of the maximum from 1.7 g/mL for vitreous B2S3 up to 2.2 g/mL for the x= 0.3 glass and decreases on the highalkali side to 1.8 g/mL. The increase in the density at low alkali is associated with the increasing fraction of the heavy mass and relatively small volume tetrahedral boron group, Na+BS4–. The density decrease in the high‐alkali range is associated with the decreasing fraction of these groups with the concomitant increase in the fraction of trigonal boron groups with increasing numbers of nonbridging (terminal) sulfurs. To model the density, a weighted fractional mass and volume model was used. The molar volumes of the individual short‐range order (SRO) groups were determined from compositions where a particular SRO group was the single group in the glass, by fitting the density data, and by interpolating between groups of known volume. The composition dependence of the fractions of the individual SRO groups was developed by combining spectroscopic evidence with chemically reasonable hypotheses of the SRO of the glasses. In this way, the density was calculated from first principles with one adjustable parameter, that of the volume of the tetrahedral boron group. The calculated densities were found to agree well with the experimental values.
Surface Damage of Yttria‐Tetragonal Zirconia Polycrystals and Magnesia‐Partially‐Stabilized Zirconia in Single‐Point Abrasion
Authors: Asif S. A. Syed , Suvisesha Muthu D. Victor , Sood Ajay Kumar , Biswas Sanjay Kumar
Published: April 2005

Commercially available 3Y‐TZP and Mg‐PSZ flats were abraded by a 150° diamond cone at ‐196°, 25°, 200°, and 400°C. The coefficient of friction, the track width, and the morphological features of the track were recorded. Raman spectroscopy was used to record the tetragonal‐to monoclinic phase transformation (t → m) as a function of distance away from the track. The study was undertaken to establish the influence of tangential traction on phase transformation and surface damage.
Influence of Grain Size on Ferroelastic Toughening and Piezoelectric Behavior of Lead Zirconate Titanate
Authors: Zhang Zhiwu , Raj Rishi
Published: April 2005

Lead zirconate titanate specimens, at composition Zr48.9+‐ 1.0/ Ti51.1+‐1.0 of grain sizes ranging from 0.5 to 15 (μm were prepared by hot pressing. The fracture toughness showed a 40% increase in the fine‐grained specimens. Poling produced anisotropy in the fracture toughness. A tensor representation for the fracture toughness, now a function of the crack plane normal and the poling direction, is developed. The maximum and minimum values in the toughness tensor are shown to be related to the unpoled toughness by a simple phenomenological relationship. We also find that the piezoelectric coefficient, d33, shows a slight increase for the fine‐grained specimens, which is in conflict with the general view that smaller‐grained materials can sustain vanishingly small values of spontaneous polarization.