bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of octylglucoside and triton X‐100 on the kinetics and specificity of carnitine palmitoyltransferase
Authors: Fiol Carol J. , Bieber Loran L.
Published: January 2007

The effects of octylglucoside on the substrate specificity, kinetics and aggregation state of purified carnitine palmitoyltrasferase (CPT) from beef heart mitochondria were investigated and compared to the effects of Triton X‐100. Conditions in which CPT can be assayed in the absence of micelles and albumin, thereby eliminating miceller effects on the kinetic parameters, are described. When octylglucoside is substituted for Triton X‐100, the specificity of CPT in the forward direction shifts towards the long‐chain acyl‐CoAs, and large changes in the kinetic constants are observed. The K0.5 for L‐carnitine varied as much as 50‐fold, depending on the acyl‐CoA and detergent used. At pH 8.0 and 200 μM palmitoyl‐CoA, the K0.5 for L‐carnitine is 4.9 mM in 12 mM octylglucoside and 0.2 mM in 0.1% Triton X‐100. Octylglucoside enhances the activity of CPT with long‐chain acyl‐CoA and lowers the K0.5 for these substrates. At pH 6.0, the K0.5 for palmitoyl‐CoA is 24.2 μM in 0.1% Triton X‐100, in contrast to 3.1 μM in 12 mM octylglucoside. Octylglucoside is a competitive inhibitor of CPT with octanoyl‐CoA as substrate with a Ki of 15 mM. Nonlinear kinetics for both acyl‐CoAs and L‐carnitine are observed when the concentration of octylglucoside is reduced to less than half of its critical micellar concentration (cmc). Gel filtration of CPT in octylglucoside below its cmc gives a single protein peak with a molecular mass of ca. 660,000 daltons. These data indicate that the catalytically active form of purified CPT is an aggregate that has quaternary structure and must have a very flexible catalytic site whose affinity for substrate and catalytic efficiency can be altered greatly by changes in environment and experimental conditions.
Effect of choline, ethanolamine and serine supplementation on the membrane properties ofMicrosporum gypseum
Authors: Pandey R. , Verma R. S. , Khuller G. K.
Published: January 2007

Phospholipid bases, choline and ethanolamine, when supplemented in the growth medium ofMicrosporum gypseum resulted in an increase in the corresponding phospholipid and total phospholipid content. However, when serine was supplemented, marginal changes were observed. The fatty acid profile of phospholipids remained almost unchanged. The uptake of lysine, leucine and aspartic acid in the spheroplasts of choline‐ and ethanolamine‐grown cells was higher as compared to the control. 1‐Anilinonaphathalene‐8‐sulfonate (ANS) binding to the spheroplast membrane, as calculated from Scatchard plots, demonstrated an increase in the number of binding sites in choline‐ and ethanolamine‐grown cells, while a decrease was observed in the serine‐supplemented cells. The results are discussed in terms of the effect of phospholipid polar head group composition on the membrane structure and function of this fungus.
Lack of regression of preestablished gallstones in mice
Authors: Beynen Anton C.
Published: January 2007

Feeding a high cholesterol, high cholic acid diet to mice for 28 days caused increased concentrations of plasma and liver cholesterol and formation of gallstones. Removal of cholesterol and cholic acid from the diet led to normalization of plasma and liver cholesterol within 28 days. Regression of the preestablished gallstones did not occur within 107 days.
Fatty acid biosynthesis during embryogenesis in the amphibianBufo arenarum Hensel
Authors: Miceli Dora C. , Brenner Rodolfo R.
Published: January 2007

The fatty acid composition and biosynthesis of fatty acids were studied during early embryogenesis of the toadBufo arenarum Hensel. The ova and stages up to the 6 1/2 day embryo have similar fatty acid compositions, with ca. 70% unsaturated acids. The eggs and embryo were permeable to acetate and impermeable to palmitic, linoleic, and eicosa‐8,11,14‐trienoic acid. Labeled acetate was incorporated by the eggs into the saturated acids‐lauric, myristic, palmitic, stearic, arachidic, and behenic‐and into the unsaturated acids‐myristoleic, palmitoleic, oleic, and eicosaenoic acids. During segmentation and gastrulation, de novo biosynthesis of fatty acids increased, desaturation to myristoleic, palmitoleic, and oleic acids was enhanced; and fatty acids were esterified to triglycerides, phosphatidyl choline, and phosphatidyl ethanolamine. The feeding embryo (11 days) changed the pattern of incorporation to less incorporation into triglycerides.
Effect of vitamin E deficiency on the lipid class and fatty acid composition of rat brain gray and white matter
Authors: Vatassery G. T. , Berry J. F. , Younozai R. , Bergad P. Lam
Published: January 2007

Three‐week old male Sprague‐Dawley rats were placed on a control or vitamin E‐deficient diet for 9 months. The total lipid and cholesterol contents of brain gray and white matter areas in the vitamin E‐deficient group did not differ from controls. The concentration of cerebrosides was lower in white matter but higher in gray matter of deficient animals. However, sulfatide was significantly (P<0.001) higher in white and gray matter of deficient animals compared with controls. Lysolecithin was not found in vitamin E‐deficient gray matter but was present in control gray matter lipids. No marked differences were found in the concentrations or relative amounts of sphinogomyelin, phosphatidyl choline, phospholipids of gray or white matter of vitamin E‐deficient rats as compared to controls. In addition no remarkable differences were found in the fatty acid composition of total lipid extracts of gray or white matter from vitamin E‐deficient rats when compared with controls.
Albumin‐bound docosahexaenoic acid and collagen‐induced human platelet reactivity
Authors: Gaudette Douglas C. , Holub Bruce J.
Published: January 2007

Anin vitro system designed to mimic the effect of various plasma nonesterified (polyunsaturated) fatty acids on platelet function and metabolism was employed. Human platelet aggregation induced by submaximal (1.8 μg/ml) collagen stimulation was significantly inhibited by 2 min preincubation with 20 μM albumin‐bound docosahexaenoic acid (22∶6n−3) (DHA), but not by the other fatty acids tested. [3H]Phosphatidic acid (PA) formation, an indicator of phospholipase C activation following platelet stimulation, was moderately inhibited by eicosapentaenoic acid (20∶5n−3), 11,14,17‐eicosatrienoic acid (20∶3n−3), dihomo‐γ‐linolenic acid (20∶3n−6), as well as DHA, but not by arachidonic acid (20∶4n−6); this inhibition of phospholipase C activation could not explain the differential effect of DHA on platelet aggregation. The decreased production of thromboxane A2 (TxA2), as assessed by [3H]12‐hydroxy‐5,8,10‐heptadecatrienoic acid (HHT) formation, may account for the inhibition of collagen‐induced aggregation by 20 μM DHA. Surprisingly, preincubation with 40 μM albumin‐bound DHA, even though resulting in greater inhibition of collagen‐induced aggregation, had less impact on HHT formation. A small but significant increase in [3H]prostaglandin D2 (PGD2) levels following 3‐min collagen stimulation may have contributed to the greater antiaggregatory effect of 40 μM DHA. It is concluded that increased plasma nonesterified DHA may contribute to the dampened platelet activation and altered metabolism following fish oil supplementation of the diet.
Discharge of newly‐synthesized dolichol and ubiquinone with lipoproteins to rat liver perfusate and to the bile
Authors: Elmberger P. Göran , Kalen Anders , Brunk Ulf T. , Dallner Gustav
Published: January 2007

An effective system for perfusing rat liver using complete tissue culture medium and washed calf erythrocytes as oxygen carriers was devised. Infusion of taurocholate and glucose proved necessary to maintain stable metabolic activity an bile secretion during a 6‐hr period. Perfusate pO2, pCO2 and pH values were monitored continuously and found to be stable. Electron microscopic examination revealed the maintenance of normal hepatic structure, even after 6 hr. Normal rates of protein and urea synthesis, no leakage of cytoplasmic enzymes, and continuous bile acid production demonstrated the functional integrity of this system. Using [3H]mevalonic acid as precursor, dolichol, dolichyl phosphate, ubiquinone and cholesterol were found to be continuously synthesized in this perfusate, indicating discharge through the ER‐Golgi system. The lipoproteins of the perfusate were isolated by ultracentrifugation and characterized with respect to size distribution and lipid composition. Dolichol was found in VLDL, LDL and HDL fractions, with the highest concentration present in the latter. In rat and human blood plasma this lipid was mainly associated with HDL. The ubiquinone in the perfusate was primarily associated with the VLDL fraction, while in rat plasma it was found more evenly distributed among all the three lipoprotein fractions studied. Dolichol, ubiquinone and cholesterol were also discharged to the bile, whereas dolichyl phosphate was not. Thus, newly‐synthesized dolichol and ubiquinone are transported out of the hepatocyte to the blood and to the bile.
Synthesis of trideuteratedO‐alkyl platelet activating factor and lyso derivatives
Authors: Prakash Chandra , Saleh Sam , Taber Douglass F. , Blair Ian A.
Published: January 2007

Racemic heavy isotope analogs of 1‐O‐alkyl‐sn‐glycero‐3‐phosphocholine (lysoPAF) and 1‐O‐alkyl‐2‐O‐acetyl‐sn‐glycero‐3‐phosphocholine (PAF) were prepared for use as internal standards to facilitate quantitative studies based on mass spectrometry. Starting from pentadencane‐1,15‐diol andrac‐glycerol‐1,2‐acetonide, a convergent synthesis of 1‐O‐[16′‐2H3]hexadecyl and 1‐O‐[18′‐2H3]octadecylrac‐glycero‐3‐phosphocholine and their acetyl derivatives is described. Three deuterium atoms were introduced at the terminal position of the 1‐O‐alkyl group by displacement of thep‐toluensulfonyl group from 1‐O‐alkyl‐15′‐p‐toluensulfonate and 1‐O‐alkyl‐17′‐p‐toluensulfonate with [2H3]‐methylmagnesium iodide. The 1‐O‐alkyl‐17′‐p‐toluensulfonate was obtained by reaction of the 1‐O‐alkyl‐15′‐p‐toluensulfonate with allylmagnesium bromide, followed by reductive ozonolysis and treatment withp‐toluenesulfonyl chloride. The hydroxyl group at C‐2 was protected by a benzyl group and removed at a late stage in the synthesis. This provided the corresponding lysoderivatives or allowed preparation of racemic PAF by subsequent acetylation of the free hydroxy group. The phosphocholine moiety was introduced at glycerol C‐3 by reaction with bromoethyldichlorophosphate and trimethylamine. The synthetic compounds were analyzed by FAB/MS and GC/NICIMS. They were shown to contain less than 0.6% protium impurity.
Plasma lipoproteins in dairy cows with naturally occurring severe fatty liver: Evidence of alteration in the distribution of apo A‐I‐containing lipoproteins
Authors: Mazur Andrzej , Marcos Edgardo , Rayssiguier Yves
Published: January 2007

The relationships between fatty liver in dairy cows and reduced levels of plasma lipoproteins, and particularly of low density lipoproteins (LDL), has been previously described. Since electrophoretic heterogeneity of ultracentrifugally isolated LDL (d, 1.006–1.063 g/ml) has been found, the exact nature of this reduction in cows with fatty liver was investigated. Lipoproteins from control and severely afflicted animals were isolated by ultracentrifugation and affinity chromatography on heparin‐Sepharose CL 6 B. Gradient gel electrophoresis of lipoproteins on 4–30% gels and an immunolocalization study of apoprotein A‐I (apo A‐I) showed that control animals have two subpopulations of apo A‐I‐containing particles with a mean radius of 6.52 and 5.05 nm. In the fatty liver cows, the former was clearly shifted toward smaller particles. We concluded that the depressed level and compositional modifications of LDL in severe fatty liver cows result from a decrease in the oversized apo A‐I‐containing lipoproteins which can be isolated in the LDL density range. This could stem from the decreased supply of triglyceride‐rich lipoprotein surface components for the production of these lipoproteins. The modifications can be plausibly explained by a reduced synthesis or secretion of very low density lipoproteins (VLDL) by the liver.
Environmental changes in the northern Altai during the last millennium documented in Lake Teletskoye pollen record
Authors: Andreev Andrei A. , Pierau Roberto , Kalugin Ivan A. , Daryin Andrei V. , Smolyaninova Lyubov G. , Diekmann Bernhard
Published: January 2007

A high-resolution pollen record from Lake Teletskoye documents the climate-related vegetation history of the northern Altai Mountain region during the last millennium. Siberian pine taiga with Scots pine, fir, spruce, and birch dominated the vegetation between ca. AD 1050 and 1100. The climate was similar to modern. In the beginning of the 12th century, birch and shrub alder increased. Lowered pollen concentrations and simultaneous peaks in herbs (especially Artemisia and Poaceae), ferns, and charcoal fragments point to colder and more arid climate conditions than before, with frequent fire events. Around AD 1200, regional climate became warmer and more humid than present, as revealed by an increase of Siberian pine and decreases of dry herb taxa and charcoal contents. Climatic conditions were rather stable until ca. AD 1410. An increase of Artemisia pollen may reflect slightly drier climate conditions between AD 1410 and 1560. Increases in Alnus, Betula, Artemisia, and Chenopodiaceae pollen and in charcoal particle contents may reflect further deterioration of climate conditions between AD 1560 and 1810, consistent with the Little Ice Age. After AD 1850 the vegetation gradually approached the modern one, in conjunction with ongoing climate warming.
Competitive displacement of thin liquid films on chemically patterned substrates
Authors: LENZ RICHARD D. , KUMAR SATISH
Published: January 2007

The behaviour of the interface between stratified thin liquid films bounded by parallel solid surfaces and subject to van der Waals forces which drive dewetting is studied in this work. Chemically homogeneous surfaces are considered first; this is followed by an investigation of chemically heterogeneous surfaces. The lubrication approximation is applied to obtain a single nonlinear evolution equation which describes the interfacial behaviour, and both the linear stability and nonlinear development of the interface are examined. The sensitivity of the interfacial rupture time to problem parameters such as the viscosity ratio, initial interfacial height, interfacial tension, and magnitude of the van der Waals forces is characterized in detail for the homogeneous case. This serves as a basis for a study of the heterogeneous case, where the strong dependence of the rupture time on the length scale of the heterogeneity is found to be relatively independent of changes in the remaining problem parameters. The mechanisms underlying the rupture-time behaviour are also explored in detail. The results suggest a route by which one liquid can become emulsified in the other, and may be beneficial to industrial processes such as lithographic printing which are based on wettability phenomena.
Flutter of long flexible cylinders in axial flow
Authors: DE LANGRE E. , PAÏDOUSSIS M. P. , DOARÉ O. , MODARRES-SADEGHI Y.
Published: January 2007

We consider the stability of a thin flexible cylinder considered as a beam, when subjected to axial flow and fixed at the upstream end only. A linear stability analysis of transverse motion aims at determining the risk of flutter as a function of the governing control parameters such as the flow velocity or the length of the cylinder. Stability is analysed applying a finite-difference scheme in space to the equation of motion expressed in the frequency domain. It is found that, contrary to previous predictions based on simplified theories, flutter may exist for very long cylinders, provided that the free downstream end of the cylinder is well-streamlined. More generally, a limit regime is found where the length of the cylinder does not affect the characteristics of the instability, and the deformation is confined to a finite region close to the downstream end. These results are found complementary to solutions derived for shorter cylinders and are confirmed by linear and nonlinear computations using a Galerkin method. A link is established to similar results on long hanging cantilevered systems with internal or external flow. The limit case of vanishing bending stiffness, where the cylinder is modelled as a string, is analysed and related to previous results. Comparison is also made to existing experimental data, and a simple model for the behaviour of long cylinders is proposed.
Extensional flows with viscous heating
Authors: WYLIE JONATHAN J. , HUANG HUAXIONG
Published: January 2007

In this paper we investigate the role played by viscous heating in extensional flows of viscous threads with temperature-dependent viscosity. We show that there exists an interesting interplay between the effects of viscous heating, which accelerates thinning, and inertia, which prevents pinch-off. We first consider steady drawing of a thread that is fed through a fixed aperture at given speed and pulled with a constant force at a fixed downstream location. For pulling forces above a critical value, we show that inertialess solutions cannot exist and inertia is crucial in controlling the dynamics. We also consider the unsteady stretching of a thread that is fixed at one end and pulled with a constant force at the other end. In contrast to the case in which inertia is neglected, the thread will always pinch at the end where the force is applied. Our results show that viscous heating can have a profound effect on the final shape and total extension at pinching.
Responses of the entomopathogenic nematode,Steinernema riobraveto its insect hosts,Galleria mellonellaandTenebrio molitor
Authors: CHRISTEN J. M. , CAMPBELL J. F. , LEWIS E. E. , SHAPIRO-ILAN D. I. , RAMASWAMY S. B.
Published: January 2007

Potential hosts for infective juveniles of entomopathogenic nematodes can vary considerably in quality based on the characteristics of the host species/stage, physiological status (e.g. stress, feeding on toxins), and infection status (heterospecific or conspecific infection). In this study, we investigated responses of the entomopathogenic nematodeSteinernema riobraveto hosts (Galleria mellonellaorTenebrio molitor) that were previously parasitized with conspecifics or injected with the nematode-symbiotic bacterium,Xenorhabdussp., to determine if there is a preference for previously parasitized/injected hosts and when this preference might occur. In no-choice bioassays, the number of juveniles infecting both host species decreased with increasing time post-infection. However, infective juveniles continued to infect previously parasitized hosts up to 72 h. Significant preference was exhibited byS. riobravefor 24 h post-infectionG. mellonellalarvae over uninfected, and by 24 h post-injectionG.mellonellalarvae over 48 h post-injection larvae. No significant preference was exhibited byS. riobraveforT. molitorhosts previously parasitized with conspecifics or those injected with bacteria in any treatment combination. Such preference for, or continued infection of parasitized insects, has the potential to impact nematode efficacy.
Einstein and Oppenheimer: Interactions and Intersections
Authors: Schweber Silvan S.
Published: January 2007

Argument

The paper is an exploration of the interactions between Einstein and Oppenheimer. It highlights the sharp differences in Einstein's and Oppenheimer's approach to physics, in their presentation of self as iconic figures, and in their relation to the communities they considered themselves part of. To understand their differing approaches to physics it briefly reviews the kinds of unifications that took place in physics during the first two-thirds of the twentieth century and points to the 1961 MIT centennial celebration to demonstrate the potency of Einstein's vision that there might be a fundamental theory from which all known theories could be derived. It also briefly reviews various aspects of the development of theoretical physics and of general relativity in the first two-thirds of the twentieth century, to better understand the context of the sharp, negative remarks that Oppenheimer made about Einstein and about his theory of general relativity in 1965 on the occasion of the tenth anniversary of Einstein's death. To answer the question: “Why the antagonism on Oppenheimer's part?” it looks at Oppenheimer's and Einstein's relation to their Jewish roots, their stance regarding nationalism, and their philosophical commitments.
In vivo real-time ethanol vapor detection in the interstitial fluid of a Wistar rat using piezoresistive microcantilevers
Authors: Cheney C. Parks , Wig A. , Farahi R. H. , Gehl A. , Hedden D. L. , Ferrell T. L. , Ji D. , Bell R. , McBride W. J. , O’Connor S.
Published: January 2007

Real-time, in vivo measurements were taken in the interstitial fluid of a Wistar rat after administering 2.5g∕kg ethanol by intraperitoneal injection. A low-power piezoresistive microcantilever sensor array was used with polymer coatings suitable for measuring ethanol concentrations at 100% humidity over several hours. A hydrophobic, vapor permeable nanopore membrane was used to screen liquid and ions while allowing vapor to pass to the sensor that was implanted into the saline environment presented by the interstitial fluid. The real-time measurements followed the time scale of previous blood ethanol concentration data.
Simulation of Ti diffusion into LiNbO3 in Li-rich atmosphere
Authors: Zhang De-Long , Zhuang Yu-Ran , Hua Ping-Rang , Pun E. Y. B.
Published: January 2007

A model is proposed for describing two-dimensional diffusion of Ti into an initially congruent LiNbO3 crystal under a Li-enriched atmosphere created by a mixed two-phase (Li3NbO4 and LiNbO3) powder at elevated temperature [vapor transport equilibration (VTE)]. The influence of VTE treatment on Ti diffusivity is considered in the model. To solve the model, four key input parameters including Li-concentration-dependent Li and Ti diffusivities and two switching times t1 and t2 were determined. Prior to solve the Ti-diffusion model, a one-dimensional VTE model is solved at first to obtain the dynamic Li2O concentration depth profile. Both the Li-diffusion and Ti-diffusion models were solved by using finite difference method. Based on secondary-ion-mass spectrometry analysis, the validity of the VTE and Ti-diffusion models as well as the numerical method employed are confirmed. After that, diffusion at 1100°C of an 8-μm-wide, 100-nm-thick Ti strip defined on the surface of a Z-cut or an X-cut substrate was simulated for the VTE duration up to 130h. Based on the numerical results, the Ti-(Li-)diffusion characteristics are discussed in the aspects of (1) the relation of depth and width profile function of Ti concentration to the VTE duration, (2) the substrate cut effect on both the Ti and Li diffusions, (3) the relation of the 1∕e Ti-concentration depth and half-width to the VTE duration, and (4) the VTE duration dependence of the mean [Li]∕[Nb] ratio within the Ti-diffused layer.
Awaking of ferromagnetism in GaMnN through control of Mn valence
Authors: Sonoda S. , Tanaka I. , Oba F. , Ikeno H. , Hayashi H. , Yamamoto T. , Yuba Y. , Akasaka Y. , Yoshida K. , Aoki M. , Asari M. , Araki T. , Nanishi Y. , Kindo K. , Hori H.
Published: January 2007

Room temperature ferromagnetism of GaMnN thin film is awaked by a mild hydrogenation treatment of a sample synthesized by molecular beam epitaxy. Local environment of Mn atoms is monitored by Mn-L2,3 near edge x-ray absorption fine structure technique. Doped Mn ions are present at substitutional sites of Ga both before and after the hydrogenation. No secondary phase can be detected. Major valency of Mn changes from 3+ to 2+ by the hydrogenation. The present result supports the model that the ferromagnetism occurs when Mn2+ and Mn3+ are coexistent and holes in the midgap Mn band mediate the magnetic coupling.
Emergence and evolution of tripole vortices from net-circulation initial conditions
Authors: Barba L. A. , Leonard A.
Published: January 2007

The emergence of coherent vortical structures is a hallmark of the evolution of two-dimensional turbulence. Two fundamental processes of this evolution have been identified in vortex merging and vortex axisymmetrization. The question of whether axisymmetrization is a universal process has recently been answered in the negative. In the linear approximation, vortices indeed become axisymmetric, due to shear-enhanced diffusion. In the case of nonlinear interactions, other outcomes are possible; in the present work, we discuss a situation in which the flow reorganizes into a tripolar vortex. By performing an extensive numerical study, spanning the parameter space, we pursue the questions of what dictates if the flow will become axisymmetric or will develop into a quasisteady tripolar vortex, and what are the stages and the time scales of the flow evolution. The initial condition in this study consists of a Gaussian monopole with a quadrupolar perturbation. The amplitude of the perturbation and the Reynolds number determine the evolution. A tripole emerges for sufficiently large amplitude of the perturbation, and we seek to find a critical amplitude that varies with Reynolds number. We make several physical observations derived from visualizing and postprocessing numerous flow simulations: looking at the decay of the perturbation with respect to viscous or shear diffusion time scales; applying mixing theory; obtaining the first few azimuthal modes of the vorticity field; and describing the long-time evolution.
Study of water dynamics and distances in paramagnetic solids by variable-temperature two-dimensional H2 NMR spectroscopy
Authors: Antonijevic Sasa , Persson Erik
Published: January 2007

A recently proposed two-dimensional H2 NMR experiment is used to measure the H2 (spin I=1) quadrupolar and paramagnetic shift anisotropy interactions in powdered CuCl2∙2D2O as a function of temperature. The principal components of the quadrupolar and paramagnetic shift anisotropy tensors and the Euler angles describing the orientations of the tensors in the molecular frame are determined at each temperature. For this purpose an analytical approach is introduced to extract desired parameters from motionally averaged two-dimensional line shapes where the averaging is introduced by rapid 180° flips around C2 axes of D2O molecules. This approach can be readily applied to study various materials containing water of crystallization. It is also clearly shown that the rapid continuous rotation of D2O molecules around their C2 axes is not taking place in the studied solid in the range of temperatures between 209 and 344K. Once the paramagnetic shift anisotropy of a deuterium atom is measured accurately it is used to estimate the distance between deuterium and the nearest copper atom bearing an unpaired electron. Excellent agreement is found between structural parameters obtained in this study and those provided by neutron and x-ray diffraction, showing that the paramagnetic shift anisotropy is a sensitive probe of distances in paramagnetic solids.
Thomson scattering diagnostics of the plasma generated in a hollow anode with a ferroelectric plasma source
Authors: Yarmolich D. , Vekselman V. , Gleizer J. Z. , Hadas Y. , Felsteiner J. , Krasik Ya. E.
Published: January 2007

Thomson scattering of a laser beam was applied to study the plasma parameters inside a hollow anode having a ferroelectric plasma source incorporated in it. This method allowed avoiding difficulties related to spectroscopical measurements in the case of unknown electron energy distribution. It was found that the electron density and energy of the ferroelectric plasma are ∼1015cm−3 and ⩽5eV, respectively, and the density of the hollow anode bulk plasma is ∼6×1013cm−3. Applying an accelerating pulse for electron extraction from the bulk plasma leads to an increase in the electron density and energy of the ferroelectric plasma up to 6×1016cm−3 and ⩽20eV, respectively.
Ultrahigh sensitivity Hall effect in magnetic multilayers
Authors: Zhu Yun , Cai J. W.
Published: January 2007

Pt-based ferromagnetic alloy thin films are known to exhibit very large extraordinary Hall effect (EHE) with maximum Hall slope around 20μΩcm∕T at room temperature for optimum Fe–Pt alloy films. The authors report features of the EHE observed in Fe∕Pt and Co0.9Fe0.1∕Pt multilayers. For Fe∕Pt multilayers, the room temperature Hall slope is comparable with that of Fe–Pt alloy thin films over a broad sublayer thickness range. For Co0.9Fe0.1∕Pt multilayers, the Hall slope increases by tens of times, reaching 545μΩcm∕T at room temperature through choosing appropriate sublayer thickness and the number of Co0.9Fe0.1∕Pt bilayers. While keeping good linearity, the EHE sensor made of Co0.9Fe0.1∕Pt multilayers has field sensitivity of up to 1200V∕AT, appreciably higher than the sensitivity of semiconductor Hall sensors commonly used. Besides, the dynamic field range can be varied in EHE sensors with compound multilayers of Co0.9Fe0.1∕Pt and Fe∕Pt. The great enhancement in Hall slope (or sensitivity) and the adjustable operation field range are realized via manipulation of the perpendicular interface anisotropy and shape anisotropy in the multilayers.
Growth of single-crystalline RuO2 nanowires with one- and two-nanocontact electrical characterizations
Authors: Liu Yee-Lang , Wu Zong-Yi , Lin Kuei-Jiun , Huang Jr-Jeng , Chen Fu-Rong , Kai Ji-Jung , Lin Yong-Han , Jian Wen-Bin , Lin Juhn-Jong
Published: January 2007

Single-crystalline RuO2 nanowires were grown by using a thermal evaporation method. A control of the sizes (width and length) and the length-to-width ratio of the nanowires were achieved by tuning the growth time. A transmission electron microscope–scanning tunneling microscope technique invoking one-nanocontact electrical characterization was adopted to determine the room-temperature resistivity (∼100μΩcm) of the nanowires. An e-beam lithography technique facilitating two-nanocontact measurements was performed to establish the metallic characteristic of individual nanowires. The authors found that a nanocontact may introduce high contact resistance, nonlinear current-voltage characteristics, and even semiconducting behavior in the temperature dependent resistance.
Structural and electronic properties of Al12X+ (X=C, Si, Ge, Sn, and Pb) clusters
Authors: Chen G. , Kawazoe Y.
Published: January 2007

Using the first-principles method with the generalized gradient approximation, the authors have studied the structural and electronic properties of Al12X+ (X=C, Si, Ge, Sn, and Pb) clusters in detail. The ground state of Al12C+ is a low symmetry Cs structure instead of an icosahedron. However, the Si, Ge, Sn, and Pb atom doped cationic clusters favor icosahedral structures. The ground states for Al12Si+ and Al12Ge+ are icosahedra, while the C5ν structures optimized from an icosahedron with a vertex capped by a tetravalent atom have the highest binding energy for Al12Sn+ and Al12Pb+ clusters. The Ih structure and the C5ν structure are almost degenerate for Al12Ge+, whose binding energy difference is only 0.03eV. The electronic properties are altered much by removing an electron from the neutral cluster. The binding strength of a valence electron is enhanced, while the binding energy of the cluster is reduced much. Due to the open electronic shell, the band gaps between the highest occupied molecular orbital and the lowest unoccupied molecular orbital are ∼0.3eV for the studied cationic clusters.
Epitaxial growth of SrTiO3 thin film on Si by laser molecular beam epitaxy
Authors: Zhou X. Y. , Miao J. , Dai J. Y. , Chan H. L. W. , Choy C. L. , Wang Y. , Li Q.
Published: January 2007

Sr Ti O 3 thin films have been deposited on Si (001) wafers by laser molecular beam epitaxy using an ultrathin Sr layer as the template. X-ray diffraction measurements indicated that SrTiO3 was well crystallized and epitaxially aligned with Si. Cross-sectional observations in a transmission electron microscope revealed that the SrTiO3∕Si interface was sharp, smooth, and fully crystallized. The thickness of the Sr template was found to be a critical factor that influenced the quality of SrTiO3 and the interfacial structure. Electrical measurements revealed that the SrTiO3 film was highly resistive.
Prevalence and Risk Factors for Bloodborne Exposure and Infection in Correctional Healthcare Workers
Authors: Gershon Robyn R. M. , Sherman Martin , Mitchell Clifford , Vlahov David , Erwin Melissa J. , Lears Mary Kathleen , Felknor Sarah , Lubelczyk Rebecca A. , Alter Miriam J.
Published: January 2007

Objective.

To determine the prevalence and risk factors for bloodborne exposure and infection in correctional healthcare workers (CHCWs).

Design.

Cross-sectional risk assessment study with a confidential questionnaire and serological testing performed during 1999-2000.

Setting.

Correctional systems in 3 states.

Results.

Among 310 participating CHCWs, the rate of percutaneous injury (PI) was 32 Pis per 100 person-years overall and 42 Pis per 100 person-years for CHCWs with clinical job duties. Underreporting was common, with only 25 (49%) of 51 Pis formally reported to the administration. Independent risk factors for experiencing PI included being age 45 or older (adjusted odds ratio [aOR], 2.41 (95% confidence interval (CI), 1.31-4.46]) and having job duties that involved needle contact (aOR, 3.70 [95% CI, 1.28-10.63]) or blood contact (aOR, 5.05 [95% CI, 1.45-17.54]). Overall, 222 CHCWs (72%) reported having received a primary hepatitis В vaccination series; of these, 150 (68%) tested positive for anti-hepatitis B surface antigen, with negative results significantly associated with receipt of last dose more than 5 years previously. Serologic markers of hepatitis В virus infection were identified in 31 individuals (10%), and the prevalence of hepatitis B virus infection was 2% (n = 7). The high hepatitis B vaccination rate limited the ability to identify risk factors for infection, but hepatitis C virus infection correlated with community risk factors only.

Conclusion.

Although the wide coverage with hepatitis B vaccination and the decreasing rate of hepatitis C virus infection in the general population are encouraging, the high rate of exposure in CHCWs and the lack of exposure documentation are concerns. Continued efforts to develop interventions to reduce exposures and encourage reporting should be implemented and evaluated in correctional healthcare settings. These interventions should address infection control barriers unique to the correctional setting.
Two Regions of the Tail Are Necessary for the Isoform-specific Functions of Nonmuscle Myosin IIB
Authors: Sato Masaaki K. , Takahashi Masayuki , Yazawa Michio
Published: January 2007

To function in the cell, nonmuscle myosin II molecules assemble into filaments through their C-terminal tails. Because myosin II isoforms most likely assemble into homo-filaments in vivo, it seems that some self-recognition mechanisms of individual myosin II isoforms should exist. Exogenous expression of myosin IIB rod fragment is thus expected to prevent the function of myosin IIB specifically. We expected to reveal some self-recognition sites of myosin IIB from the phenotype by expressing appropriate myosin IIB rod fragments. We expressed the C-terminal 305-residue rod fragment of the myosin IIB heavy chain (BRF305) in MRC-5 SV1 TG1 cells. As a result, unstable morphology was observed like MHC-IIB−/−fibroblasts. This phenotype was not observed in cells expressing BRF305 mutants: 1) with a defect in assembling, 2) lacking N-terminal 57 residues (N-57), or 3) lacking C-terminal 63 residues (C-63). A myosin IIA rod fragment ARF296 corresponding to BRF305 was not effective. However, the chimeric ARF296, in which the N-57 and C-63 of BRF305 were substituted for the corresponding regions of ARF296, acquired the ability to induce unstable morphology. We propose that the N-57 and C-63 of BRF305 are involved in self-recognition when myosin IIB molecules assemble into homo-filament.
I. Recent Developments in UK Extradition Law
Authors: Warbrick Colin , Warbrick Colin
Published: January 2007

In July 2006, three bankers, all UK nationals, were extradited to the United States on charges of conspiracy to defraud their one-time employers, a British bank, a subsidiary of Natwest. The conduct took place under the shadow of the ‘Enron’ affair. The defendants were said to have conspired with senior officials of Enron. Enron was the subject of the largest corporate bankruptcy in US history. In comparison the sums involved in the Enron collapse, those at stake in what the papers called the ‘Natwest Three’ case were small, but the involvement of persons implicated in the Enron affair made the defendants of interest to US prosecutors. The cases enjoyed an unusual public profile, partly because the extraditions took place under the unique legal regime which governs US-UK extradition,1partly because this case was simply one of several cases in which persons charged with what one might loosely call economic crimes were sought by US prosecutors2and partly because the defendants argued that their offences (which they denied) were allegations of what were ‘really’ English crimes which should have been proceeded with here. Although the extradition aspects have loomed largest, this last matter, possible conflicts of criminal jurisdiction, is the most interesting.
Observations with the Electron Microscope on the Internal Structure of the Spermatozoid of Fucus
Authors: MANTON I. , CLARKE B.
Published: January 2007

After preliminary description of antheridial dehiscence, details have been given of the internal structure and position inside the body of the Fucus spermatozoid of the following organs: mitochondria, chromatophore and eyespot, ciliary bases, proboscis. The position and approximate shape of the nucleus both expanded and in the coiled condition are described. The body membrane and its relation to the covering membrane of the proboscis and two flagella are described. The plane of symmetry of both flagella relative to the surface of the body is described.

The more important individual facts recorded are:

1. The plane of symmetry in both flagella is at right angles to the body surface, passing between but not through the two central strands in each flagellum.

2. A group of dark bodies previously mistaken for the nucleus are mitochondria.

3. The proboscis is part of the ciliary apparatus; it is covered on each side by a membrane and the internal thickening bands are attached at one end to the basal body of the front flagellum.
Osteonecrosis of the Jaw Associated With Bisphosphonate Use: Presentation of Seven Cases and Literature Review
Authors: Mortensen Melissa , Lawson William , Montazem Andre
Published: January 2007

Problem Addressed: Bisphosphonates, pyrophosphate analogs, are strong osteoclast inhibitors that are used for osteoporosis and in the treatment of solid tumors with bony metastasis. There are growing reports of osteonecrosis associated with the nitrogen containing bisphosphonates, Pamindronate and Zolendronic acid therapy. Theses cases have been most commonly seen and treated by oral surgeons. An untreated maxillary osteonecrosis can lead to pansinusitis, involving the otolaryngologist in these patients' care. To the authors' knowledge, this is the first case series reported in the otolaryngology literature.

Patients and Methods: A retrospective chart review was conducted on patients presenting to the Mount Sinai Hospital Center and at Elmhurst General Hospital between October 2003 and November 2004 with a history of refractory osteomyelitis of the jaws and chronic bisphosphonate therapy.

Results: Seven patients were identified with both of these conditions. These patients presented with nonhealing ulcers of the mandible or maxilla. Four of the patients were on bisphosphonate therapy, and the other three had been treated with bisphosphonates. Three of the patients required extensive operations to remove the involved bone. One patient required endoscopic sinus surgery.

Conclusions: Increasing reports of bisphosphonate associated osteomyelitis and the difficulty in treating these patients requires further investigation to identify the subset of patients who are at increased risk for this process. The optimal and safe duration of treatment with bisphosphonates needs to be determined.
Tackling the Child Malnutrition Problem: From What and Why to How Much and How
Authors: McLachlan Milla
Published: January 2007

There is strong economic evidence to invest in improving the economic status of young children, yet programs remain underresourced. Returns on investment in child nutrition in terms of improved health, better education outcomes and increased productivity are substantial, and cost estimates for effective programs are in the range of $2.8 to $5.3 billion. These amounts are modest when compared with total international development assistance or current spending on luxury goods in wealthy nations. New initiatives to redefine nutrition science and to apply innovative problem‐solving technologies to the global nutrition problem suggest that steps are being taken to accelerate progress toward a malnutrition‐free world.
Priorities in Nutritional Rehabilitation
Authors: Zlotkin Stanley
Published: January 2007

This review examines nutritional rehabilitation and stresses nutrition prophylaxis or prevention because for school‐age children, health promotion and disease prevention are the keys to a healthy childhood.
CTLA‐4 expressed by chemoresistant, as well as untreated, myeloid leukaemia cells can be targeted with ligands to induce apoptosis
Authors: Laurent Stefania , Palmisano Giulio L. , Martelli Alberto M. , Kato Tomohiro , Tazzari Pier Luigi , Pierri Ivana , Clavio Marino , Dozin Beatrice , Balbi Giuseppe , Megna Mauro , Morabito Anna , Lamparelli Teresa , Bacigalupo Andrea , Gobbi Marco , Pistillo Maria Pia
Published: January 2007

We have previously reported that about 80% of acute myeloid leukaemia (AML) samples tested at diagnosis constitutively expressed cytotoxic T‐lymphocyte‐associated antigen‐4 (CTLA‐4). The present study compared CTLA‐4 expression and function of leukaemic cells from AML patients at diagnosis with those from AML patients resistant to conventional chemotherapy. We also explored the possibility of targeting CTLA‐4 for apoptosis induction in chemoresistant AML cells. AML cells either from untreated patients (n = 15) or in chemoresistant phase (n = 10) were analysed for CTLA‐4 protein and transcript expression by flow cytometry and reverse transcription‐polymerase chain reaction respectively. CTLA‐4 expression was similar in untreated and in chemoresistant samples and was not associated with patients’ clinical features. In chemoresistant AML cells, CTLA‐4 transduced an apoptotic signal on engagement with its recombinant ligands r‐CD80 and r‐CD86, which induced an average of 71% and 62% apoptotic cells, respectively, at highest concentration. Apoptosis was equally induced in untreated leukaemic cells accompanied by cleavage of procaspase‐8 and ‐3. Thus, this study provides the first evidence that killing of leukaemic cells from AML patients may be obtained by the engagement of CTLA‐4 with its ligands, opening the way to a novel potential therapeutic approach based on triggering the CTLA‐4 molecule to circumvent chemoresistance in AML.
Longitudinal study of dental caries in Brazilian children aged from 12 to 30 months
Authors: SCAVUZZI ANA ISABEL FONSECA , JUNIOR ARNALDO DE FRANÇA CALDAS , COUTO GERALDO BOSCO LINDOSO , VASCONCELOS MÁRCIA MARIA BARBOSA VENDICIANO DE , SOARES RENATA PATRÍCIA DE FREITAS , VALENÇA PAULA ANDRÉA MELO
Published: January 2007

Objective.  The purpose of the present study was to investigate caries in a sample of young children in Brazil.

Methods.  A prospective longitudinal study of dental caries was carried out on a sample of 186 children aged from 12 to 30 months in Feira de Santana, Bahia, where the water supply is optimally fluoridated. The sample was composed of children accompanied by their mother or guardian and was part of a public health child care programme. After 11 months, all the mothers or guardians and children who took part in the initial examination were contacted, of whom 85.7% attended follow‐up. Oral examinations for the detection of dental caries, visible plaque (VP) and white spots (WS) were performed at the beginning of the study and after one year. The statistical analysis consisted of frequency distributions, means and standard deviations, bivariate analysis, and calculation of relative risk, adopting confidence intervals of 95%.

Results.  The prevalence of dental caries at the initial examination was 6.4%, rising approximately threefold by 12 months. When the presence of WS also took the form of dental caries, the prevalence of the disease almost doubled. A statistically significant difference was seen between the decayed, missing and filled primary teeth (dmft) found at the initial examination and that at the end of the study. In addition, there was an increase in the dmft index during the course of the study, both for the children who presented with WS and VP, and for those without these conditions.

Conclusions.  A low prevalence of dental caries was observed among the children studied at the initial examination, but around 20% of these children presented with new disease during the period of the study. Amongst children with lesions at the start, the presence of caries almost doubled between examinations.
Juvenile recurrent parotitis: clinical, sialographic and ultrasonographic features
Authors: SITHEEQUE MOHAIDEEN , SIVACHANDRAN YALINI , VARATHAN VIDYA , ARIYAWARDANA ANURA , RANASINGHE AJITH
Published: January 2007

Objective.  Juvenile recurrent parotitis (JRP) is a rare salivary gland disease of obscure aetiology that affects children. The aim of this study was to investigate the patterns of clinical presentation, and the sialographic and ultrasonographic features of JRP in Sri Lankan children.

Methods.  The authors analysed the hospital records of 26 subjects who had been diagnosed with JRP between January 2003 and April 2006.

Results.  The subjects consisted of 15 males and 11 females (male:female ratio = 1.4:1). The age range of the sample was 2.5–16 years (mean = 8.4 years). The age of onset was biphasic, with two major peaks at 6 years (n = 6) and 10 years (n = 5) (mean = 6.73 years). Unilateral involvement was seen in 69.2% of patients. The commonest clinical features were swelling (100%), pain (80.8%) and fever (50.0%). The average frequency of recurrences of JRP in 18 patients was 7.1 times per year. The average duration of an individual episode, also in 18 patients, was 5.44 days. Sialography in 17 patients had revealed punctate sialectasis, whereas ultrasonography in 16 patients had demonstrated multiple hypoechoic areas and heterogeneous echoes

Conclusions.  This study documents the clinical features of JRP in Sri Lankan children. It has established the usefulness of sialography and ultrasonography in the diagnosis of JRP.