bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of stearic acid on hemostatic risk factors in humans
Authors: Tholstrup Tine
Published: November 2006

Stearic acid has been claimed to be prothrombotic. Elevated plasma factor VII coagulant activity (FVIIc) may raise the risk of coronary thrombosis in the event of plaque rupture. Fibrinogen, an acute‐phase protein, is necessary for normal blood clotting; however, elevated levels of fibrinogen increase the risk of coronary heart disease (CHD). Here I report the results of three controlled, human dietary intervention studies, which used a randomized crossover design to investigate the hemostatic effects of stearic acid‐rich test diets in healthy young men. A diet high in stearic acid (shea butter) resulted in a 13% lower fasting plasma FVIIc than a high palmitic acid diet, and was 18% lower than a diet high in myristic and lauric acids (P=0.001) after 3 wk of intervention. The stearic acid‐rich test fat increased plasma fibrinogen concentrations slightly compared with the myristic‐lauric acid diet (P<0.01). When investigating the acute effects of fatty meals, those high in stearic acid (synthesized test fat) resulted in a smaller postprandial increase in FVII than those high in trans and oleic FA, indicating a smaller increase in activated FVII after ingesting stearic acid compared with fats high in monounsaturated FA, probably caused by lower postprandial lipemia. Thus, the present investigations did not find dietary stearic acid to be more thrombogenic, in either fasting effects compared with other longchain FA, or in acute effects compared with dietary unsaturated FA, including trans monounsaturated FA. The slightly increased effect on fasting plasma fibrinogen may be biologically insignificant, but it should be investigated further.
Trans isomeric octadecenoic acids are related inversely to arachidonic acid and DHA and positively related to mead acid in umbilical vessel wall lipids
Authors: Decsi Tamás , Boehm Günther , Tjoonk H. M. Ria , Molnár Szilárd , Dijck‐Brouwer D. A. Janneke , Hadders‐Algra Mijna , Martini Ingrid A. , Muskiet Frits A. J. , Boersma E. Rudy
Published: November 2006

Long‐chain PUFA play an important role in early human neurodevelopment. Significant inverse correlations were reported between values of trans isomeric and long‐chain PUFA in plasma lipids of preterm infants and children aged 1–15 yr as well as in venous cord blood lipids of full‐term infants. Here we report FA compositional data of cord blood vessel wall lipids in 308 healthy, full‐term infants (gestational age: 39.7±1.2 wk, birth weight: 3528±429 g, mean±SD). The median (interquartile range) of the sum of 18‐carbon trans FA was 0.22 (0.13)% w/w in umbilical artery and 0.16 (0.10)% w/w in umbilical vein lipids. Nonparametric correlation analysis showed significant inverse correlations between the sum of 18‐carbon trans FA and both arachidonic acid and DHA in artery (r=−0.38, P<0.01, and r=−0.20, P<0.01) and vein (r=−0.36, P<0.01, and −0.17, P<0.01) wall lipids. In addition, the sum of 18‐carbon trans FA was significantly positively correlated to Mead acid, a general indicator of EFA deficiency, in both artery (r=+0.35, P<0.01) and vein (r=+0.31, P<0.01) wall lipids. The present results obtained in a large group of full‐term infants suggest that maternal trans FA intake is inversely associated with long‐chain PUFA status of the infant at birth.
Synthesis of 9,9,9‐trideutero‐1,4‐dihydroxynonane mercapturic acid (d3‐DHN‐MA), a useful internal standard for DHN‐MA urinalysis
Authors: Chantegrel B. , Deshayes C. , Doutheau A. , Steghens J. P.
Published: November 2006

Racemic 1,4‐dihydroxynonane mercapturic acid (DHN‐MA) and 9,9,9‐trideutero‐1,4‐dihydroxynonane mercapturic acid (d3‐DHN‐MA) are synthesized on a 400‐mg scale (over‐all yield ∼40%) by a two‐step sequence involving Michael addition of N‐acetyl‐l‐cysteine to methyl‐4‐hydroxynon‐2(E)‐enoate or methyl 9,9,9‐trideutero‐4‐hydroxynon‐2(E)‐enoate, followed by reduction of the intermediate adducts with lithium borohydride. The requisite starting methyl esters are obtained, respectively, from heptanal or 7,7,7‐trideuteroheptanal and methyl 4‐chlorophenyl‐sulfinylacetate via a sulfoxide piperidine and carbonyl reaction described in the literature. The 7,7,7‐trideuteroheptanal is easily prepared by classical methods in four steps from 6‐bromo‐1‐hexanol. 13C NMR data indicate that DHN‐MA as well as d3‐DHN‐MA are obtained as mixtures of four diastereomers. Preliminary results show that d3‐DHN‐MA could be used as an internal standard for mass spectrometric quantification of DHN‐MA in human urine.
Antioxidant‐restricted diet reduces plasma nonesterified fatty acids in trained athletes
Authors: Watson Trent A. , Blake Robert J. , Callister Robin , Garg Manohar L.
Published: November 2006

Nonesterified FA (NEFA) are a major fuel source for humans at rest and during moderate exercise. The effect of dietary antioxidant restriction on plasma NEFA levels and exercise performance in trained athletes was examined. Seventeen athletes followed a 2‐wk restricted‐antioxidant (R‐AO) diet, which resulted in a threefold reduction in antioxidant intake (ascorbic acid, 139 to 49 mg; β‐carotene, 5093 to 1142 μg) and a significant (P=0.001) reduction in the plasma NEFA. The amount and types of fat consumed were not different between the R‐AO and habitual diets. Exercise time to exhaustion was not affected by the R‐AO diet, but rating of perceived exertion (RPE) was significantly (P=0.03) elevated. The increase in RPE may have occurred as a result of the R‐AO diet and subsequent reduction in plasma NEFA; however, further research is required to confirm this conclusion.
Kinetics, inhibition and oligomerization of Epstein‐Barr virus protease
Authors: Buisson Marlyse , Rivail Lucie , Hernandez Jean-François , Jamin Marc , Martinez Jean , Ruigrok Rob W.H. , Burmeister Wim P.
Published: November 2006

Epstein‐Barr virus (EBV) is an omnipresent human virus causing infectious mononucleosis and EBV associated cancers. Its protease is a possible target for antiviral therapy. We studied its dimerization and enzyme kinetics with two enzyme assays based either on the release of paranitroaniline or 7‐amino‐4‐methylcoumarin from labeled pentapeptide (Ac‐KLVQA) substrates. The protease is in a monomer–dimer equilibrium where only dimers are active. In absence of citrate the K
d is 20 μM and drops to 0.2 μM in presence of 0.5 M citrate. Citrate increases additionally the activity of the catalytic sites. The inhibitory constants of different substrate derived peptides and α‐keto‐amide based inhibitors, which have at best a K
i of 4 μM, have also been evaluated.
Surgical Treatment of Pheochromocytomas
Authors: Gavaghan Mary
Published: November 2006

Pheochromocytomas are tumors that develop from chromaffin tissue of the embryonic sympathoadrenal system. These tumors may occur anywhere chromaffin tissue exists but most often develop in the adrenal medulla. Less than 50% of patients are diagnosed with pheochromocytomas while alive, and most of these tumors are found on autopsy. The classic signs and symptoms of pheochromocytomas are headache, perspiration, palpitations, pallor, and paroxysmal hypertension. Elevated levels of vanillylmandelic acid and metanephrines in patients' 24‐hour urine collections are the most reliable diagnostic indicators of pheochromocytomas. Most patients with pheochromocytomas can be cured if diagnoses and surgical resections of tumors occur before irreversible cardiovascular disease and end‐organ damage from hypertension develop. AORN J 65 (June 1997) 1041‐1071.
Essentials of Perioperative Nursing
Authors: Bartlett Carolyn
Published: November 2006

ESSENTIALS OF PERIOPERATIVE NURSING, Second ed By Cynthia Spry 1997, 303 pp $57 hardcover
FACTS, NOT OPINIONS, DRIVE SCIENCE: A REPLY TO MORRISON
Authors: CAMERON PAUL
Published: November 2006

Accuracy is the most important aspect of empiricism. If investigators are clear about their method and employ it to generate ‘facts,’ their opinions are irrelevant. So it is of some significance that Morrison, who spends more than one-third of his paper attacking my motives — indeed accusing me of ‘hatred of gay men and lesbian women’ — does not dispute my findings. Strip away the ad hominem attacks and little remains.
In situ measurements of colloid transport and retention using synchrotron X‐ray fluorescence
Authors: DiCarlo David A. , Zevi Yuniati , Dathe Annette , Giri Shree , Gao Bin , Steenhuis Tammo S.
Published: November 2006

The physics regarding the retention and mobilization of colloids in saturated and unsaturated conditions remains poorly understood, partially because of the inability to measure colloid concentrations in situ. In this study, we attached Cd+2 ions to clay colloids and used synchrotron X rays to cause the Cd to fluoresce. By measuring the fluorescence and attenuation of the X rays we obtained simultaneous in situ water saturations and colloid concentrations on timescales of tens of seconds. We used this technique to study the transport of colloids consisting of Na and Ca Montmorillonite clays through a preferential flow path in uniform well‐sorted sand. This flow path had both saturated and unsaturated zones that travel downward with time. We found that the Na colloids showed little retention in the sand, while the Ca colloids were retarded with respect to the wetting front. By comparing the results to those obtained by infiltrations with a Cd solute we find that the retention of the colloids seen in the unsaturated portion of the column was no greater than that seen in the saturated portion. We discussed the advantages and limitations of this X‐ray fluorescence technique and the implications for colloid transport.
Grjotá Valles and implications for flood sediment deposition on Mars
Authors: Burr Devon M. , Parker Alex H.
Published: November 2006

Grjotá Valles is one of Mars' four Amazonian‐aged, fissure‐headed, catastrophic flood channels. It originates at the northwestern‐most Cerberus Fossa and stretches several hundred kilometers eastward and southward. Moats around in‐channel knobs and various small‐scale mounds, similar to mounds seen in Athabasca Valles, are both attributed to flood‐related processes. The floodwater sinks are ambiguous, and the lack of recognizable flood deposits is attributed to two causes. The first cause is the channel's high width‐to‐depth ratio, which may have facilitated floodwater recession during flooding. The second cause is the tendency of floodwater under lower gravity to move a higher percentage of material as washload. As flood deposits are comprised of bedload and suspended load, this tendency would result in fewer depositional bedforms. Our analysis of Grjotá Valles supports the idea that formation of terrestrial‐style flood deposits is energetically unlikely on Mars and that their presence indicates special paleohydraulic conditions.
Utah State University Global Assimilation of Ionospheric Measurements Gauss‐Markov Kalman filter model of the ionosphere: Model description and validation
Authors: Scherliess L. , Schunk R. W. , Sojka J. J. , Thompson D. C. , Zhu L.
Published: November 2006

The Utah State University Gauss‐Markov Kalman Filter (GMKF) was developed as part of the Global Assimilation of Ionospheric Measurements (GAIM) program. The GMKF uses a physics‐based model of the ionosphere and a Gauss‐Markov Kalman filter as a basis for assimilating a diverse set of real‐time (or near real‐time) observations. The physics‐based model is the Ionospheric Forecast Model (IFM), which accounts for five ion species and covers the E region, F region, and the topside from 90 to 1400 km altitude. Within the GMKF, the IFM derived ionospheric densities constitute a background density field on which perturbations are superimposed based on the available data and their errors. In the current configuration, the GMKF assimilates slant total electron content (TEC) from a variable number of global positioning satellite (GPS) ground sites, bottomside electron density (Ne) profiles from a variable number of ionosondes, in situ Ne from four Defense Meteorological Satellite Program (DMSP) satellites, and nighttime line‐of‐sight ultraviolet (UV) radiances measured by satellites. To test the GMKF for real‐time operations and to validate its ionospheric density specifications, we have tested the model performance for a variety of geophysical conditions. During these model runs various combination of data types and data quantities were assimilated. To simulate real‐time operations, the model ran continuously and automatically and produced three‐dimensional global electron density distributions in 15 min increments. In this paper we will describe the Gauss‐Markov Kalman filter model and present results of our validation study, with an emphasis on comparisons with independent observations.
Process control and melt depth homogenization for SiC-on-Si structures during flash lamp annealing by carbon implantation
Authors: Smith M. P. , McMahon R. A. , Voelskow M. , Skorupa W. , Stoemenos J. , Ferro G.
Published: November 2006

Flash lamp annealing in the millisecond regime of heteroepitaxial silicon carbide on silicon structures involves melting the silicon below the SiC layer, but the deep faceted nature of the liquid-solid interface leads to unacceptable surface roughness. This paper describes a method of controlling melting by implanting a high dose of carbon at a controlled depth below the Si∕SiC interface, which significantly alters the melting characteristics of the silicon. This technology has also been applied to SiC and Si multilayer heterostructures. Results confirm the effectiveness of this approach for increasing surface uniformity, making liquid phase processing compatible with standard device fabrication techniques. A thermal model has also been developed to describe this process and results indicate that the theoretical work is consistent with the experimental evidence. The model is a valuable tool for predicting the onset of melting, maximum temperatures, and process windows for controlled liquid phase epitaxy.
Carbon “peapods”—a new tunable nanoscale graphitic structure (Review)
Authors: Krive I. V. , Shekhter R. I. , Jonson M.
Published: November 2006

We consider the electronic properties of empty single-wall nanotubes (SWNT) and SWNT filled with fullerene molecules (carbon “nano-peapods”). The first part of the review (Sec. II) is devoted mostly to the Luttinger liqued properties of individual metallic SWNT coupled to metallic electrodes or to superconducting leads. The discovery of carbon “nano-peapods” and their elastic, electric and thermal properties are reviewed in the second part of the paper (Sec. III). We suggest in particular how fullerene and metallofullerene molecules can be released from a “nano-peapod” by a purely electrostatic method.
Density, spin, and isospin correlations in low-density two-component Fermi superfluid
Authors: Isayev A. A. , Yang J.
Published: November 2006

Finding the distinct features of the crossover from the regime of large overlapping Cooper pairs to the limit of non-overlapping pairs of fermions (Shafroth pairs) in multi-component Fermi systems remains a topical problem in a quantum many-body theory. Here this transition is studied by calculating the two-body density, spin and isospin correlation functions in dilute two-component Fermi superfluid, taking as an example an infinite system of protons and neutrons (nuclear matter). It is shown that criterion of the crossover [Phys. Rev. Lett. 95, 090402 (2005)], formulated for ultracold fermionic atomic gases and consisting in the change of the sign of the density correlation function at low momentum transfer, fails to describe correctly the density-driven BEC–BCS transition at finite isospin asymmetry or finite temperature. As an unambiguous signature of the BEC–BCS transition, one can use the presence (BCS regime) or absence (BEC regime) of the singularity in the momentum distribution of the quasiparticle density of states.
Energy level alignment symmetry at Co/pentacene/Co interfaces
Authors: Popinciuc M. , Jonkman H. T. , van Wees B. J.
Published: November 2006

We have employed x-ray and ultraviolet photoemission spectroscopies (XPS and UPS) to study the energy level alignment and electronic structure at the Co/pentacene/Co interfaces. In the case of pentacene deposition on Co we found an interfacial dipole of about 1.05eV and a hole injection barrier of 0.96eV, whereas for the case of Co deposition on pentacene we found a similar value for the hole injection barrier and vacuum level alignment (∼0eV interfacial dipole), respectively. By combining XPS and UPS we were able to identify that chemical reaction occurs between pentacene and Co. The results of the deposition of the reactive Co on pentacene indicates only a small penetration depth of the metal atoms into the pentacene layer. A complete band diagram for the layered Co/pentacene/Co structure is presented in the frame of a model with interfacial dipoles. Finally, our findings are linked to spin injection experiments.
Conversion of laser radiation to terahertz frequency waves in plasma
Authors: Yampolsky N. A. , Fraiman G. M.
Published: November 2006

A new scheme of terahertz radiation (T-ray) amplification based on four-wave coupling in plasma is proposed. Three stages of the amplification, namely, linear, initial nonlinear, and advanced nonlinear are analyzed. It is shown that (1) during the advanced nonlinear stage, a series of T-ray pulses with fixed energies is generated, and (2) the duration of each pulse decreases during the amplification, while the pulse amplitude grows. Possible parameters of the actual experimental apparatus are also suggested.
Strain study of self-assembled InAs quantum dots by ion channeling technique
Authors: Wang Hsing-Yeh , Lee Chien-Ping , Niu H. , Chen C. H. , Wu S.-C.
Published: November 2006

Ion channeling technique using MeV C++ ions was used to study strain in self-assembled InAs quantum dots (QDs) buried in GaAs matrix. Because of the use of heavy ions, we were able to observe an angular shift in the angular scan of the In signal relative to that of the Ga∕As signal. This provided a direct evidence that the InAs lattice is larger than that of GaAs in the growth direction. Combining the channeling results in [100] and [110] directions and the photoluminescence emission spectrum, we conclude that the InAs QDs are under tensile strain in the growth direction and have the same lattice constant as that of GaAs in the lateral direction. Thermal annealing causes the strain to relax, first in the growth direction and then in the lateral direction as the annealing temperature increases. The photoluminescence spectra of the QDs before and after annealing indicate, however, that composition intermixing also takes place during annealing and is the dominant factor in determining the band gap energy of the QDs.
Transformation of electrical transport from variable range hopping to hard gap resistance in Zn1−xFexO1−v magnetic semiconductor films
Authors: Tian Y. F. , Yan Shi-shen , Zhang Y. P. , Song H. Q. , Ji G. , Liu G. L. , Chen Y. X. , Mei L. M. , Liu J. P. , Altuncevahir B. , Chakka V.
Published: November 2006

Transformation of the electrical transport from the Efros and Shklovskii [J. Phys. C 8, L49 (1975)] variable range hopping to the “hard gap” resistance was experimentally observed in a low temperature range as the Fe compositions in Zn1−xFexO1−v ferromagnetic semiconductor films increase. A universal form of the resistance versus temperature, i.e., ρ∝exp[TH∕T+(TES∕T)1∕2], was theoretically established to describe the experimental transport phenomena by taking into account the electron-electron Coulomb interaction, spin-spin exchange interaction, and hard gap energy. The spin polarization ratio, hard gap energy, and ratio of exchange interaction to Coulomb interaction were obtained by fitting the theoretical model to the experimental results. Moreover, the experimental magnetoresistance was also explained by the electrical transport model.
Magnetotransport properties of Fe3O4 epitaxial thin films: Thickness effects driven by antiphase boundaries
Authors: Ramos A. V. , Moussy J.-B. , Guittet M.-J. , Bataille A. M. , Gautier-Soyer M. , Viret M. , Gatel C. , Bayle-Guillemaud P. , Snoeck E.
Published: November 2006

We present an in-depth study of the magnetotransport properties of epitaxial Fe3O4 films as a function of film thickness. The films, grown on α-Al2O3(0001) single crystals by atomic-oxygen assisted molecular beam epitaxy, exhibit high structural order and abrupt interfaces. These films contain antiphase boundaries (APBs), the density of which is strongly dependent on film thickness. A series of resistivity and magnetoresistance measurements demonstrate a systematic evolution of these properties with decreasing film thickness, revealing the impact of APBs on the transport properties in the films. We present a model based on the spin-polarized transport across an antiferromagnetically coupled APB in order to successfully reproduce our experimental data over a large range of applied magnetic fields. The comparison of this model with experimental results further clarifies the mechanism of the anomalous magnetotransport behavior in Fe3O4.
Gate-controlled nuclear magnetic resonance in an AlGaAs∕GaAs quantum Hall device
Authors: Masubuchi S. , Hamaya K. , Machida T.
Published: November 2006

The authors study the resistively detected nuclear magnetic resonance (NMR) in an AlGaAs∕GaAs quantum Hall device with a side gate. The strength of the hyperfine interaction between electron and nuclear spins is modulated by tuning a position of the two-dimensional electron systems with respect to the polarized nuclear spins using the side-gate voltages. The NMR frequency is systematically controlled by the gate-tuned technique in a semiconductor device.
Refractive index measurement of single living cells using on-chip Fabry-Pérot cavity
Authors: Song W. Z. , Zhang X. M. , Liu A. Q. , Lim C. S. , Yap P. H. , Hosseini Habib Mir M.
Published: November 2006

This letter reports the measurement of single living cells’ refractive index (RI) using an on-chip fiber-based Fabry-Pérot cavity by a differential method. In experiment a single cell is captured into the cavity, then the spectral shift in response to the buffer change and the cell presence/absence can be used to determine the cell’s RI and size. Experiment on kidney cancer cells measures an effective RI of 1.399 at 0.1% accuracy. Compared with other approaches, the differential method eliminates uncertain factors and thus ensures high accuracy. The microchip facilitates automatic detection and makes it promising for label-free drug screening.
Remarkable solute trapping within rapidly growing dendrites
Authors: Wang H. P. , Yao W. J. , Wei B.
Published: November 2006

Solute microsegregation always takes place during dendritic crystal growth. Although this may be reduced with the increase of crystal growth velocity, the realization of segregationless dendritic growth is quite difficult. Here the authors present the results of remarkable solute trapping within the rapidly growing dendrites of highly undercooled liquid Ni–5wt%Si alloy. The dendrites grow at a velocity of 15m∕s at the maximum experimental undercooling of 304K. Such a high growth velocity results in the pronounced solute trapping and almost segregationless solidification. Furthermore, a model is proposed to describe the correlation between dendritic growth velocity and undercooling. It agrees well with the experimental results in the whole undercooling regime and provides a reasonable prediction for the dendritic growth trend under extremely great undercooling conditions.
Room-temperature InAsSbP∕InAs light emitting diodes by liquid phase epitaxy for midinfrared (3–5μm) dynamic scene projection
Authors: Malyutenko V. K. , Malyutenko O. Yu. , Zinovchuk A. V.
Published: November 2006

The InAsSbP∕InAs light emitting diodes (LEDs) grown by liquid phase epitaxy and tuned at several wavelengths inside the 3–5μm band were tested. Light pattern, radiation apparent temperature (Ta), thermal resistance, and self-heating details were characterized at T=300K in microscale by calibrated infrared cameras operating in the 3–5 and 8–12μm bands. The authors show that LEDs dynamically simulate very hot (Ta⩾750K) targets as well as cold objects and low observable. They resume that low cost LEDs enable a platform for photonic scene projection devices able to compete with thermal microemitter technology. Proposals on how to further increase LEDs performance are given.
Impact of thin SrTiO3 seed layer to achieve low-temperature crystallization below 300°C and ferroelectricity of lead zirconate titanate thin film
Authors: Moon Ji-Won , Tazawa Shogo , Shinozaki Kazuo , Wakiya Naoki , Mizutani Nobuyasu
Published: November 2006

The authors report low-temperature preparation of Pb(Zr0.6,Ti0.4)O3 (PZT) thin films below 300°C using SrTiO3 seed layers on (111)Pt∕IrO2∕SiO2∕(001)Si substrates by metal-organic chemical vapor deposition. The critical parameters contributing low-temperature preparation for PZT were crystallinity and orientation of SrTiO3 seeds and deposition rate of PZT films. Using 1–2nm of SrTiO3 with (h00) and (hh0) mixed orientations, polycrystalline PZT films could be obtained at 290°C with deposition rate of 0.5–1.0nm∕min. The remanent polarization (2Pr) and coercive field (2Ec) of PZT films on SrTiO3 seeds with deposition rate of 0.5nm∕min were 42.4μC∕cm2 and 256kV∕cm, respectively.
Preparation, Spectroscopic Characterization and X-Ray Structure of [Dicyclohexylphosphinyl-N-methyl(thioformamide)]gold(I) Chloride: Au[Cy2P(O)C(S)N(H)Me]Cl
Authors: Siasios G , Tiekink ERT
Published: November 2006

The reaction of [AuCl4]- with Cy2P(O)C(S)N(H)Me in the presence of thiodiglycol affords the air-stable adduct Au[Cy2P(O)C(S)N(H)Me] Cl which features a linear gold atom geometry defined by a chloride atom and a sulfur atom derived from a monodentate thioformamide ligand. The pale-green crystals are monoclinic, space group P21, with unit cell dimensions a 18.507(4), b 12.204(2), c 18.513(6) Ǻ, β 117.69(2)°, Z 8; the structure was refined to final R 0.042, 4106 reflections being used.
The Reactions of Electrogenerated [Ni(sacsac)2]-: Biomimetic Chemistry Related to Nickel Enzymes
Authors: Lay PA , Masters AF , Wasiowych CD
Published: November 2006

The electrochemical reduction of [Ni( sacsac )2] ( sacsac = C5H7S2- = pentane-2,4-dithionate) has been investigated by cyclic voltammetry and controlled-potential electrolysis in acetone/tetra- butylammonium tetrafluoroborate (0.1 M). The reactions of the reduction product(s) with CO, CO2, CH3I, C12H25SH, light and water have been surveyed. At a scan rate of 100 mV s-1, [Ni( sacsac )2] (0.5 mM ) undergoes a quasi-reversible one-electron reduction (∆ Ep = 88 mV) at -1.543 V (v. Fc+/0) and an irreversible four-electron oxidation at +0.635 V. The oxidation generates the 3,5-dimethyl-1,2-dithiolium cation, as evidenced by the observation of the (known) reduction of this cation at -0.840 V. The initial product of the reduction of [Ni( sacsac )2] is a Lewis base, and reacts with light, water, CO, CO2, CH3I and C12H25SH. These reactions have been followed by electrochemical and spectroscopic methods. They appear to be biomimetic for a number of reactions observed for nickel enzymes.
Theoretical Evaluation of Alternative Pathways in the Stevens Rearrangement
Authors: Heard GL , Yates BF
Published: November 2006

Ab initio and semi-empirical molecular orbital theory has been used to explore the ion-pair and lithium-catalysed pathways in the Stevens rearrangement of an alkylammonium ylide to an amine. These pathways represent alternatives to the concerted and free radical mechanisms which we have previously studied. Solvation effects have been included via a polarizable continuum model. Finally, the calculations have been extended to a set of experimentally observable compounds. For the nine systems studied here, the stepwise free radical pathway is predicted in every case to be the favourable mechanism for the Stevens rearrangement. Single-point MP2/6-31G(d) calculations on fully optimized PM3 geometries are shown to provide a useful method of including electron correlation at low computational cost.
New Oxygenated Sesquiterpenes From a Southern Australian Marine Sponge, Dictyodendrilla sp.
Authors: Tran NH , Hooper JNA , Capon RJ
Published: November 2006

Chemical investigation of a Dictyodendrilla sp. from Port Phillip Bay, Victoria, yielded three new oxygenated sesquiterpenes, dictyodendrillin -A (6), -B (7) and -C (8), together with the known sesquiterpene dendrolasin (9). Structures for all these metabolites were established by spectroscopic analysis.
Scats can reveal the presence and habitat use of cryptic rock-dwelling macropods
Authors: Telfer Wendy R. , Griffiths Anthony D. , Bowman David M. J. S.
Published: November 2006

The rock-dwelling macropod species of the tropics of the Northern Territory, Australia, are behaviourally elusive and difficult to observe in their rugged habitats. Hence, little is understood about their ecology. We evaluated the potential of using scats (faecal pellets) as a survey tool for this faunal assemblage by: (1) developing a key to the scats of the species; (2) examining the rates of loss and decomposition of short-eared rock-wallaby (Petrogale brachyotis) scats in these tropical environments; and (3) comparing the distribution of scats of P. brachyotis with the species’ use of space and habitats as determined with radio-telemetry. Classification tree modelling discriminated the scats of the seven macropod species, primarily on the basis of width. The reliability of identification was greatly improved with larger sample sizes and inclusion of a habitat parameter. Rates of scat loss and decay were variable and the greatest losses occurred in the wet season, particularly on sandy soils. Scat censuses underestimated the total area used by P. brachyotis but the distribution of scats showed the same broad pattern of habitat use found by radio-telemetry. We conclude that scats can accurately indicate the presence and habitat preferences of rock-dwelling macropod species.
Scattering from laterally heterogeneous vesicles. I. Model-independent analysis
Authors: Pencer Jeremy , Anghel Vinicius N. P. , Kučerka Norbert , Katsaras John
Published: November 2006

This is the first of a series of papers considering the scattering from laterally heterogeneous vesicles. Here, it is shown that contrast variation studies on unilamellar vesicles can be analyzed in a model-independent manner to detect lateral segregation in model membranes. In particular, it is demonstrated that the Porod invariant,Q= \textstyle\int q^{2}I (q )\,{\rm d}q, is related to the scattering length density contrast between compositionally distinct regions in a heterogeneous membrane. The formation of domains and the concomitant identification of phase boundaries as a function of either membrane composition or temperature can therefore be detected in the changes taking place inQ.
Anomalous diffraction at ultra-high energy for protein crystallography
Authors: Jakoncic Jean , Di Michiel Marco , Zhong Zhong , Honkimaki Veijo , Jouanneau Yves , Stojanoff Vivian
Published: November 2006

Single-wavelength anomalous diffraction (SAD), multiwavelength anomalous diffraction (MAD) and single isomorphous replacement with anomalous scattering (SIRAS) phasing at ultra-high X-ray energy, 55 keV, are used successfully to determine a high-quality and high-resolution experimental electronic density map of hen egg-white lysozyme, a model protein. Several combinations, between single- and three-wavelength, with native data were exploited to demonstrate that standard phasing procedures with standard equipment and software can successfully be applied to three-dimensional crystal structure determination of a macromolecule, even at these very short wavelengths. For the first time, a high-quality three-dimensional molecular structure is reported from SAD phasing with ultra-high-energy X-rays. The quality of the crystallographic data and the experimental electron density maps meet current standards. The 2.7% anomalous signal from three Ho atoms, at the HoKedge, was sufficient to obtain a remarkable electron density and build the first lanthanide structure for HEWL in its entirety.
DASH: a program for crystal structure determination from powder diffraction data
Authors: David William I. F. , Shankland Kenneth , van de Streek Jacco , Pidcock Elna , Motherwell W. D. Samuel , Cole Jason C.
Published: November 2006

DASHis a user-friendly graphical-user-interface-driven computer program for solving crystal structures from X-ray powder diffraction data, optimized for molecular structures. Algorithms for multiple peak fitting, unit-cell indexing and space-group determination are included as part of the program. Molecular models can be read in a number of formats and automatically converted to Z-matrices in which flexible torsion angles are automatically identified. Simulated annealing is used to search for the global minimum in the space that describes the agreement between observed and calculated structure factors. The simulated annealing process is very fast, which in part is due to the use of correlated integrated intensities rather than the full powder pattern. Automatic minimization of the structures obtained by simulated annealing and automatic overlay of solutions assist in assessing the reproducibility of the best solution, and therefore in determining the likelihood that the global minimum has been obtained.
On the compression mechanism of FeF3
Authors: Jørgensen J.-E. , Smith R. I
Published: November 2006

The structure of FeF3, iron trifluoride, has been studied in the pressure range from ambient to 8.28 GPa by time-of-flight neutron powder diffraction. No structural phase transitions were found within the investigated pressure range, and least-squares refinements of the crystal structures were performed in the space group R\overline 3 c for all recorded data sets. It was found that volume reduction is achieved through rotation of the FeF6 octahedra, and the Fe—F—Fe bond angle decreases from 152.5 (2) to 134.8 (3)° within the investigated pressure range. A small octahedral strain was found to develop during compression, which reflects an elongation of the FeF6 octahedra along the c axis. The zero-pressure bulk modulus B_o and its pressure derivative B_o' were determined to be 14 (1) GPa and 12 (1), respectively.
Interplay between steric and electronic factors in determining the strength of intramolecular N—H...O resonance-assisted hydrogen bonds in β-enaminones
Authors: Bertolasi Valerio , Pretto Loretta , Ferretti Valeria , Gilli Paola , Gilli Gastone
Published: November 2006

The crystal structures of five β-enaminones are reported: (2Z)-3-(benzylamino)-1,3-diphenyl-prop-2-en-1-one, (2Z)-3-(benzylamino)-3-(2-hydroxyphenyl)-1-phenyl-prop-2-en-1-one, (2Z)-3-(benzylamino)-3-(4-methoxyphenyl)-1-(3-nitrophenyl)-prop-2-en-1-one, 2-{1-[(4-methoxyphenyl)amino]ethylidene}cyclohexene-1,3-dione and 2-{1-[(3-methoxyphenyl)amino]ethylidene}cyclohexene-1,3-dione. The structures were analysed and compared with those of similar compounds in order to establish which factors determine the range (2.53–2.72 Å) of N...O hydrogen-bond distances in intramolecularly hydrogen-bonded β-enaminones. It has been shown that, beyond electronic resonance-assisted hydrogen-bond effects modulated by substituents, the necessary requirements to produce very short N—H...O hydrogen bonding are steric intramolecular repulsions, including the embedding of an enaminonic C—C or C—N bond in an aliphatic six-membered ring. By considering the structural features it is possible to expect the strength of N—H...O hydrogen bonds adopted by specific β-enaminones.
Structural characterization of p-benzosemiquinone radical in a solid state: the radical stabilization by a low-barrier hydrogen bond
Authors: Molčanov Krešimir , Kojić-Prodić Biserka , Roboz Mario
Published: November 2006

Semiquinone (p-benzosemiquinone), a transient organic radical, was detected in the solid state by EPR spectroscopy revealing four symmetrically equivalent protons. A variable-temperature X-ray diffraction analysis (293 and 90 K) and EPR data support a dynamical disorder of the proton. A low-barrier O—H···O hydrogen bond stabilizes the radical. The C—O bond length is 1.297 (4) Å, corresponding to a bond order of ca 1.5. The geometry of the radical implies an electron delocalization throughout the benzenoid ring. Two polymorphs of semiquinone, monoclinic and triclinic, were observed and their structures determined. Their crystal packings were compared with those of quinhydrone polymorphs.
Order–disorder transition in monoclinic sulfur: a precise structural study by high-resolution neutron powder diffraction
Authors: David W. I. F. , Ibberson R. M. , Cox S. F. J. , Wood P. T.
Published: November 2006

High-resolution neutron powder diffraction has been used in order to characterize the order–disorder transition in monoclinic cyclo-octasulphur. Rapid data collection and the novel use of geometrically constrained refinements has enabled a direct and precise determination of the order parameter, based on molecular site occupancies, to be made. The transition is critical and continuous; with a transition temperature, Tc
= 198.4 (3) K, and a critical exponent, β = 0.28 (3), which is indicative of three-dimensional ordering. Difficulties encountered as a consequence of the low thermal conductivity of the sample are discussed.
Case–control study of multidrug resistance phenotype and response to induction treatment including or not fludarabine in newly diagnosed acute myeloid leukaemia patients
Authors: Malagola Michele , Damiani Daniela , Martinelli Giovanni , Michelutti Angela , Cesana Bruno , Vivo Antonio De , Piccaluga Pier Paolo , Ottaviani Emanuela , Candoni Anna , Geromin Antonella , Tiribelli Mario , Fanin Renato , Testoni Nicoletta , Lauria Francesco , Bocchia Monica , Gobbi Marco , Pierri Ivana , Zaccaria Alfonso , Zuffa Eliana , Mazza Patrizio , Priccolo Giancarla , Gugliotta Luigi , Bonini Alessandro , Visani Giuseppe , Skert Cristina , Bergonzi Cesare , Roccaro Aldo Maria , Filí Carla , Baccarani Michele , Russo Domenico
Published: November 2006

One hundred and six patients aged ≤60 years with newly diagnosed acute myeloid leukaemia (AML) treated with fludarabine‐based regimens (cases) were matched with 106 AML patients treated with conventional non‐fludarabine‐based regimens (controls). The cases and controls were matched by expression of the multidrug resistance P‐glycoprotein (MDR‐Pgp), measured by flow cytometry as mean fluorescence index (MFI), cytogenetics, and age. The complete remission (CR) rate of the cases was 61% among the MDR‐Pgp‐positive (posve) patients (MFI ≥ 6) vs. 75% among the MDR‐Pgp‐negative (negve) ones (MFI < 6) (P = 0·16). Conversely, in the controls, the CR rate was 44% among the MDR‐Pgp‐posve patients vs. 67% among the MDR‐Pgp‐negve ones (P = 0·02). The 4‐year disease‐free survival (DFS) and overall survival (OS) of MDR‐Pgp‐posve cases were significantly longer than those of MDR‐Pgp‐posve controls (DFS, 28·1% vs. 6·5%, P = 0·004; OS, 33·5% vs. 9·6%, P = 0·01). This difference was not found among the MDR‐Pgp‐negve patients. By univariate (P = 0·007) and multivariate (P = 0·007) analysis, the MDR‐Pgp‐posve phenotype was negatively correlated with CR and it emerged as the most important independent negative prognostic factor, after cytogenetics. Our study confirms the prognostic impact of the MDR phenotype in AML and strongly suggests fludarabine‐based induction treatments as a promising strategy for MDR‐Pgp‐posve AML patients. In this setting of patients, large prospective randomised studies should be planned.
Sensitivity of cells to apoptosis induced by iron deprivation can be reversibly changed by iron availability
Authors: Koc M. , Nad’ová Z. , Kovář J.
Published: November 2006

Abstract.  We tested the effect of iron deprivation on cell death induction in human Raji cells pre‐adapted to differing availability of extracellular iron. Iron deprivation was achieved by incubation in a defined iron‐free medium. Original Raji cells have previously been adapted to long‐term culture in a defined medium with 5 µg/ml of iron‐saturated human transferrin as a source of iron. Raji/lowFe cells were derived from original Raji cells by subsequent adaptation to culture in the medium with 50 µm ferric citrate as a source of iron. Raji/lowFe‐re cells were derived from Raji/lowFe cells by re‐adaptation to the transferrin‐containing (5 µg/ml) medium. Iron deprivation induced cell death in both Raji cells and Raji/lowFe‐re cells; that is, cells pre‐adapted to a near optimum source of extracellular iron (5 µg/ml of transferrin). However, Raji/lowFe cells preadapted to a limited source of extracellular iron (50 µm ferric citrate) became resistant to the induction of cell death by iron deprivation. We demonstrated that cell death induction by iron deprivation in Raji cells correlates with the activation of executioner caspase‐3 and the cleavage of caspase‐3 substrate, poly‐ADP ribose polymerase. Two other executioner caspases, caspase‐7 and caspase‐6, were not activated. Taken together, we suggest that in human Raji cells, iron deprivation induces apoptotic cell death related to caspase‐3 activation. However, the sensitivity of the cells to death induction by iron deprivation can be reversibly changed by extracellular iron availability. The cells pre‐adapted to a limited source of extracellular iron became resistant.
γ‐Tocotrienol inhibits ErbB3‐dependent PI3K/Akt mitogenic signalling in neoplastic mammary epithelial cells
Authors: Samant G. V. , Sylvester P. W.
Published: November 2006

Abstract.  The antiproliferative effects of γ‐tocotrienol are associated with suppression in epidermal growth factor (EGF)‐dependent phosphatidylinositol‐3‐kinase (PI3K)/PI3K‐dependent kinase‐1 (PDK‐1)/Akt mitogenic signalling in neoplastic mammary epithelial cells. Studies were conducted to investigate the direct effects of γ‐tocotrienol treatment on specific components within the PI3K/PDK‐1/Akt mitogenic pathway. +SA cells were grown in culture and maintained in serum‐free media containing 10 ng/ml EGF as a mitogen. Treatment with 0–8 µmγ‐tocotrienol resulted in a dose‐responsive decrease in the +SA cell growth and a corresponding decrease in phospho‐Akt (active) levels. However, γ‐tocotrienol treatment had no direct inhibitory effect on Akt or PI3K enzymatic activity, suggesting that the inhibitory effects of γ‐tocotrienol occur upstream of PI3K, possibly at the level of the EGF‐receptor (ErbB1). Additional studies were conducted to determine the effects of γ‐tocotrienol on ErbB receptor activation. Results showed that γ‐tocotrienol treatment had little or no effect on ErbB1 or ErbB2 receptor tyrosine phosphorylation, a prerequisite for substrate interaction and signal transduction, but did cause a significant and progressive decrease in the ErbB3 tyrosine phosphorylation. Because ErbB1 or ErbB2 receptors form heterodimers with the ErbB3 receptor, and ErbB3 heterodimers have been shown to be the most potent activators of PI3K, these findings strongly suggest that the antiproliferative effects of γ‐tocotrienol in neoplastic +SA mouse mammary epithelial cells are mediated by a suppression in ErbB3‐receptor tyrosine phosphorylation and subsequent reduction in PI3K/PDK‐1/Akt mitogenic signalling.
Present Status of Rinderpest Diseases in Pakistan
Authors: Matin M. A. , Rafi M. A.
Published: November 2006

All animal diseases have the potential to affect human lives adversely by reducing the quantity and/or quality of food (meat, milk, etc.), secondary livestock products (hides, skins and fibres) and animal power (traction and transport). The importance of the livestock sector is growing more rapidly than any other agricultural sector in Pakistan. In the past, livestock production in Pakistan has been affected because of transboundary animal diseases like rinderpest, foot and mouth disease and peste des petits ruminants disease, posing a serious threat to the livestock industry in Pakistan. The continuing persistence of rinderpest has been of grave concern for the entire region including Pakistan. The export of livestock products managed to retain its growth with relaxation of restrictions imposed by the Gulf states in the year 2001 only. Pakistan has been provisionally declared a rinderpest free country in 2003, as a result of a vigorous eradication programme.
Lymphocyte subsets and viral load in male AIDS patients with major depression: Naturalistic study
Authors: HUANG TIAO‐LAI , LEU HSIEH‐SHONG , LIU JIEN‐WEI
Published: November 2006

Abstract This study investigated the relationships between lymphocyte subsets and viral load in AIDS patients with and without major depression. During a 7‐year period, a total of 60 male hospitalized AIDS patients were recruited in this study. The diagnosis of major depression in patients was made by the same psychiatrist according to the 4th edition of the Diagnostic and Statistical Manual for Mental Disorders criteria. All patients had data for CD4, CD8 and CD4/CD8, and only 42 patients had viral load data. Of 60 AIDS patients, 32 patients had received highly active antiretroviral therapy and received subsequent assessment of lymphocyte cell counts 1 month later. Usingancovawith age adjustment, the authors found that patients with major depression (n = 22) had significantly lower CD8 cell counts than patients without major depression (n = 38). However, CD4 cell counts and CD4/CD8 ratios were not significantly different between these two groups. In addition, there was no significant difference in viral load between patients with major depression (n = 16) and patients without major depression (n = 26). Of 32 patients received highly active antiretroviral therapy, 14 patients with an antidepressant (e.g. fluoxetine 20 mg/day) had significantly decreased CD4 and not CD8 cell counts and significantly reduced CD4/CD8 ratios during a period of 1 month. In conclusion, these results suggest that AIDS patients with major depression had significantly lower CD8 cell counts and might have a more severe inflammation/immunity reaction than patients without major depression.
Primary adenocarcinoma of the rete testis with preceding diagnosis of pulmonary metastases
Authors: NAKAGAWA TOHRU , HIRAOKA NOBUYOSHI , IHARA FUMIE , KOMIYAMA MOTOKIYO , KANAI YAE , MATSUNO YOSHIHIRO
Published: November 2006

Abstract  We report a case of primary adenocarcinoma of the rete testis in a 55‐year‐old man with pulmonary metastases that were detected 11 months prior to the diagnosis of the primary lesion. Primary adenocarcinoma of the rete testis is an extremely rare malignant tumor with a poor outcome. The most common primary symptom is a scrotal mass, often accompanied by hydrocele and chronic epididymitis. The diagnosis is often delayed because of non‐specific clinical presentation and symptoms. We cannot forget that rete testis is a possible primary site for a primary, unknown metastatic adenocarcinoma.
Proximal‐type epithelioid sarcoma of the perineum: Calling attention of urologists
Authors: HIKOSAKA ATSUYA , YAMADA KENJI , FUJITA KEIJI , IWASE YUTAKA , TADA TOYOHIRO
Published: November 2006

Abstract  A subcutaneous mass in the perineum of a middle‐aged man was excised and pathologically diagnosed at first as ‘undifferentiated carcinoma’ of unknown origin, which recurred 2 years later without any metastasis. Further histological evaluation ultimately established a correct diagnosis of ‘proximal‐type epithelioid sarcoma’, a variant of rare epithelioid sarcoma. This type of tumor may confuse pathologists because its histological characteristics resemble undifferentiated carcinoma or malignant rhabdoid tumor. Frequent immunoreactivity of CD34, in addition to expression of keratins, epithelial membrane antigen and vimentin, provides strong support for the diagnosis of this rare neoplasm. Urologists should be aware that this sarcoma commonly occurs in the genital regions.