bluuebunny/crossref_metadata_2025 huggingface dataset:
POSSIBLE ABNORMAL MECHANISM FOR LATTICE STRAIN RELAXATION IN La0.7Ca0.3MnO3 THIN FILM
Authors: TAN W. S. , JIA Q. J. , GAO J.
Published: August 2005

La 0.7 Ca 0.3 MnO 3(LCMO) thin films with the thickness of 50 nm were deposited on (001)-oriented single crystal SrTiO 3(STO), MgO and α- Al 2 O 3(ALO) by 90° off-axis radio frequency magnetron sputtering. Grazing incidence X-ray diffraction technique, associated with normal X-ray diffraction, was performed to measure the in-plane lattice parameter and investigate the lattice strain and strain relaxation in LCMO films. The results indicated that critical thickness of strain relaxation is very small, which may be related to large mismatch between film and substrate. The mechanism for strain relaxation in LCMO film is perhaps different from that for tetragonal distortion.
DENSITY FUNCTIONAL THEORY STUDY OF W5 CLUSTERS
Authors: ZHANG XIURONG , DING XUNLEI , YANG JINLONG
Published: August 2005

Density functional theory(DFT) calculations are performed to study W 5 clusters in their neutral, anionic and cationic charge states. All the possible stable isomers are examined, and the most stable isomers for all these species are found. They are singlet state with D3h symmetry for W 5, and doublets with C2v symmetry for both [Formula: see text] and [Formula: see text]. Equilibrium geometries, electron affinities and dissociation energies are also de termined. Time-depended DFT is used to calculate the low-lying excited states of W 5. Theoretical assignments for the features in the experimental photoelectron spectra are given. All results obtained are in good agreement with available experimental data.
INTERACTION OF HIGHLY CHARGED Xeq+ (q = 26, 27, 30) IONS WITH MOLYBDENUM SURFACE
Authors: LIU ZHAOYUAN , ZHANG HONGQIANG , CHEN XIMENG , YANG ZHIHU , XU JINZHANG , YING CUI , XU XU , SHAO JIANXIONG , XIAO GUOQING , ZHANG XIAOAN , ZHAO YONGTAO , ZHANG YANPING
Published: August 2005

Experimental investigation of Molybdenum L-shell X-ray emission is reported in the collision of highly charged Xe q+ (q = 26,27,30) ions with Molybdenum surface in the energy range 400 to 600 keV. Based on the X-ray spectra obtained and by the extrapolation of experimental data to the lower incident energy range, a limit was found for the energy of the incident ions. The influence of initial charge state on X-ray emission from the target L-shell was observed. The difference of the initial charge state and electron configuration of the incident ions may lead to observably different contribution to the target atom vacancy production and L-shell X-rays emission. Based on COB model, a simple explanation was presented to interpret the features of the experimental results.
HALF-LIVES OF CLUSTER RADIOACTIVITY OF HEAVY NUCLEI
Authors: REN ZHONGZHOU , XU CHANG
Published: August 2005

The half-lives of cluster radioactivity (14C-34Si) are well reproduced by a new formula between half-lives and decay energies. This formula is a natural extension of both the Geiger-Nuttall law and the Viola-Seaborg formula from α-decay to cluster radioactivity. The half-lives of new cluster emitters are predicted based on this formula. These are useful for future experimental researches of cluster radioactivity. The physics related to this formula is analyzed and discussed.
ADSORPTION REACTION OF POLAR ORGANIC MOLECULES ON ${\rm Si}^+_n$ CLUSTER IONS
Authors: NAKAGAWARA WAKANA , TSUNOYAMA HIRONORI , FURUYA ARI , MISAIZU FUMINORI , OHNO KOICHI
Published: August 2005

We have examined chemical reactions of small silicon cluster ions [Formula: see text] for n = 7 - 16 with polar organic molecules M ( M = CH 3 CN , CD 3 OD , C 2 H 5 CN , and C 2 H 5 OH ). The intensities of the adsorption products [Formula: see text] for m = 1 and 2 were investigated as a function of n. We found for all polar molecules that the relative intensity of Si n M + to the unreacted [Formula: see text] is smaller for n = 11, 13, and 14, that is, the adsorption reactivity is smaller for these n than others. It was also commonly observed that the [Formula: see text] ion are more intense than neighboring n. We discussed the relationship of the reactivity with the geometrical structures and the stabilities of the bare [Formula: see text] ions and adsorbed [Formula: see text] ions, from theoretical calculations based on density functional theory.
FERROMAGNETISM IN Co-DOPED TiO2 ANATASE DUE TO THE COBALT CLUSTERING
Authors: ZHOU X. H. , CHEN X. S. , SUN L. Z. , SUN Y. L. , LU W.
Published: August 2005

We have performed first-principles electronic structural calculations to investigate the nature and origin of ferromagnetism in Ti 1-x Co x O 2 with cobalt concentrations x being 0.0625 and 0.125 in the interesting experimental range. In x being 0.125, when all possible arrangements of two Co atoms within a large supercell are considered, the clustering of Co atoms at nearst-neighbour Ti sites is energetically preferred. Also the interplay between clustering and exchange interactions in Co -doped anatase TiO 2 is discussed. It is predicted that the exchange coupling constant increases up to a value corresponding to lower Co concentrations by decreasing the distance between Co atoms.
AB INITIO STUDY OF MAGNETISM IN PALLADIUM CLUSTERS SUPPORTED ON (110) SURFACE OF TiO2 RUTILE
Authors: MURUGAN P. , KUMAR VIJAY , KAWAZOE YOSHIYUKI
Published: August 2005

The structural, electronic, and magnetic properties of Pd n (n = 6, 13) clusters supported on (110) surface of TiO 2 rutile have been studied using ab initio ultrasoft pseudopotential calculations within generalized gradient approximation. The magnetic moments and atomic structures of these clusters have only small changes when soft landed on the oxide surface. The magnetic moments of Pd 13 cluster on TiO 2 (110) surface is reduced to 6 μB as compared to 8 μB for free cluster. Our calculations also show that the adsorption energy differences between various orientations of Pd 13 cluster on the surface of the slab are small. Therefore, nearly spherical clusters such as Pd 13 can roll and have high mobility. The calculated adsorption energies of Pd 6 and Pd 13 on the (110) surface of TiO 2 slab are approximately 2.2 and 2.4 eV, respectively.
ANGULAR DEPENDENCE OF MAGNETIC PROPERTIES IN Co/Pt MULTILAYERS WITH PERPENDICULAR MAGNETIC ANISOTROPY
Authors: LIN W. W. , SANG H. , YOU B. , JIANG Z. S. , XIAO G.
Published: August 2005

Dependence of magnetic properties on the angles between the applied magnetic field and the normal of the film plane in Co/Pt multilayer with easy magnetization direction perpendicular to the film plane have been studied. The results show that the sample exhibits unusual magnetization behaviors when an external magnetic field applied in different angle to the normal of the sample plane. The remanence decreases and the saturation field increases with increasing the angle, accompanying the magnetization-switching field and the coercivity enhance. These results suggest that the magnetization process in multilayers with perpendicular magnetic anisotropy (PMA) could not be described simply using coherent rotation model for uniaxial anisotropic ferromagnet.
MAGNETORESISTANCE IN NANO-SCALE NiO-CONTAINING Co/Cu/Co SPIN VALVES
Authors: ZHANG A. M. , WU X. S. , SUN L. , HU A.
Published: August 2005

A series of NiO -containing Co/Cu/Co spin valves with the thickness Co of 5 nm and Cu of 2 nm were fabricated by magnetron sputtering technique with different growth parameters. NiO layer with the thickness of 40 nm is used as a coupling layer. Magnetoresistance (MR) of the spin valve with NiO layer under the bottom of Co/Cu/Co (BSV) is larger than that of the spin valve with NiO layer at the top of Co/Cu/Co (TSV) at room temperature. The MR values can be improved with decreasing the sputtering rate of copper layer. The studies by in-situ grazing incident X-ray scattering on the annealing temperature dependence of MR show that the decrease of the interface roughness between Co and NiO may increase the MR value, while the decrease of the coupling effect between NiO and Co decreases the MR value.
OPTICAL PROPERTIES OF Er AND Si-NANOCRYSTAL CO-DOPED SiO2 FILMS AT A HIGH Er CONCENTRATION REGIME
Authors: MATSUMOTO KIMIHISA , IMAKITA KENJI , FUJII MINORU , HAYASHI SHINJI
Published: August 2005

Photoluminescence (PL) properties of Er and Si nanocrystals co-doped SiO 2 films are studied in a wide Er concentration range. In the Er concentration range of less than 3 at%, Er 3+ was excited by the energy transfer from Si nanocrystals. Above this concentration, Si nanocrystals and Er do not exist independently but amorphous or crystallin alloys of Si-Er-O are formed. In this region Er can be excited only by directly absorbed excitation light. The highest PL intensity is observed in the Er concentration range where an amorphous alloy of Si-Er-O is formed.
DIELECTRIC PROPERTY OF LaAlO3 THIN FILMS DOPED WITH MAGNETIC Co AND Co3O4 CLUSTERS
Authors: JIANG H. , LIU H. W. , Yu H. , GAO F. , LIU J.-M.
Published: August 2005

The thin films of Co -doped and Co3O4-doped dielectric LaAlO3 (LAO) by co-ablation of magnetic metal Co and dielectric LAO on Pt – Ti – SiO2 – Si substrates have been prepared by pulsed laser deposition. A significant enhancement of dielectric constant of LAO upon doping of Co and cobalt oxide clusters is observed. Furthermore, modulation of the dielectric constant of the thin films by applying a magnetic field is verified, obviously due to the ferromagnetism of Co metal and Co oxide clusters embedded in the LAO thin films. A series of microstructural and dielectric characterizations on the as-prepared thin films have been performed and the mechanism underlying the dielectric enhancement upon the doping of Co and Co3O4 clusters is discussed.
2D AND 3D ORDERED STRUCTURE OF SILVER NANOPARTICLES FROM HYDROSOL
Authors: WATANABE MASAHIRO , SATO SEIICHI , YAO HIROSHI , KIMURA KEISAKU
Published: August 2005

In recent years, the physical characteristics of noble metal nanoparticles are of considerable interest to material research. We made an effort to get superlattices of Ag nanoparticles at the air/water interface so as to apply various types of measurement by transferring the formed superlattices to suitable substrates. Basic procedure involved is based on a process recently developed for mercaptosuccinic acid (MSA) modified Au nanoparticles. The MSA protected Ag nanoparticles powder was redispersed in distilled water. HCl was added and the solution was left for several days at room temperature. Small crystallites appeared at the air/liquid interface. The diameter of the nanoparticles constructing the 2D superlattice was found to be larger than the parent nanoparticles.
AMORPHOUS SILICON NANO-PARTICLES IN A-SiNx:H PREPARED BY HELICON WAVE PLASMA-ENHANCED CHEMICAL VAPOUR DEPOSITION
Authors: FU GUANG-SHENG , YANG YAN-BIN , YU WEI , LU WAN-BING , DING WEN-GE , HAN LI
Published: August 2005

Amorphous silicon nano-particles embedded in hydrogenated amorphous silicon nitride ( a - SiN x: H ) matrix have been prepared using an approach based on the deposition of Si -rich a - SiN x: H thin films by helicon wave plasma-enhanced chemical vapour deposition (HWP-CVD) technique, which has a characteristic of high plasma density at low working pressure. X-ray photoelectron spectroscopy analysis shows that the silicon atom bonds exist in the Si-Si and Si-N configurations and the amorphous silicon regions appear separately in the Si -rich a - SiN x: H films. The existence of amorphous silicon nano-particles without any post annealing in the a - SiN x: H random matrix is confirmed by the image of high-resolution transmission electron microscopy. Through infrared absorption analysis, the formation of the separated amorphous silicon nano-particles structure is closely correlated with the deposition parameters such as low working pressure and Ar dilution in the HWP-CVD process.
SONOCHEMICAL SYNTHESIS OF PbWO4 NANOPARTICLES
Authors: GENG JUN , ZHANG JIAN-RONG , HONG JIAN-MIN , ZHU JUN-JIE
Published: August 2005

Lead tungstate ( PbWO 4) an important inorganic scintillator, was synthesized via a mild sonochemical route from an aqueous solution of lead acetate and sodium tungstate in the presence of complexing agents under ambient air. X-ray diffraction (XRD), transmission electron microscope (TEM) and photoluminescence (PL) were used to characterize the products. The as-prepared PbWO 4 nanocrystals crystallize in a tetragonal structure and have an average crystal size of ca. 10 nm.
MICROWAVE HYDROTHERMAL SYNTHESIS OF RUTILE TiO2 NANORODS
Authors: MA GUOBIN , ZHAO XIAONING , ZHU JIANMIN
Published: August 2005

We present in this paper the synthesis of rutile TiO 2 nanorods using an efficient microwave hydrothermal method. The product was characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy, and the results indicated the growth of high quality rutile nanorods along the c-axis of rutile TiO 2 and the radial aggregation of them into spherical secondary nanoparticles.
ANALYSIS OF CHARACTERISTICS OF ORDERED MESOPOROUS ASSEMBLED WITH Fe, Bi AND B
Authors: ZHANG JIANCHENG , NI QILIANG , SHEN YUE , ZHOU XIAO'AN , JIANG SHENGYU , YUE LIMING
Published: August 2005

Ordered SiO 2 mesoporous materials called SBA were prepared by hydrothermal or sol-gel method through using the surfactants as the template, such as cetytrimethylammonium bromide or triblock copolymer. SBA assembled with some different elements and compounds, including Fe , Bi , and B or Fe 2 O 3, B 2 O 3 and others by dipping or adding of chelating or coupling agents were prepared to form some composites, which characterized by wide or small angle X-ray diffraction, infrared spectra, N 2 static and kinetic adsorption, high resolution transmission electron microscopy and magnetic intensity instrument, respectively. The assembled α- Fe or α- Fe 2 O 3 under different conditions possessed lower magnetic coercive force (Hc), for instance the latter was about 87-117( Hc –103/4πA*m-1– Os ), but specific saturation magnetization (σ s –A*m2*kg-1) increase by 75.4% as compared with the conventional σ- Fe 2 O 3(1765 Os ) particles. However, the properties of the composites assembled with α- Fe was different from α- Fe 2 O 3 as mentioned-above. And the relationship between σ s or Os and structure for the assembled systems was discussed. After introduced B and Bi to the mesoporous materials, the composites showed not only existence of Brφnsted acid sites for B , but also improvement of the hydrothermal stability and enhance of the long–range order magnitude.
FORMATION OF Te NANOWIRES IN ZEOLITE AFI AND THEIR POLARIZED ABSORPTION SPECTRA
Authors: INOUE SHUN-ICHI , KOSHIZAKI NAOTO , KODAIRA TETSUYA
Published: August 2005

Te atoms were loaded into nanochannels of zeolite AFI single crystals. The polarized absorption and Raman scattering spectra were measured. The absorption spectra of Te loaded AFI showed large anisotropic properties. The absorption spectra of E//c deeply depended on the loading density of Te atoms. In low Te loading density, Te was adsorbed into the nanochannels in a dimer form whose absorption peak appeared at ca. 3.5 eV . In high loading density, Te form one dimensional nanowires inside the channels. Nanowire formation causes large anisotropic absorption and changes in the spectral shape.
MICROWAVE HYDROTHERMAL SYNTHESIS AND CHARACTERIZATION OF Co3O4 NANOCRYSTALS
Authors: MA GUOBIN , ZHOU SHUNHUA , HUANG SHISONG
Published: August 2005

Microwave hydrothermal method is employed to synthesize Co 3 O 4 nanocrystals. Co ( OH )2 from reaction of C 4 H 6 CoO 4·4 H 2 O with NaOH aqueous solution is used as starting material. With a fixed hold time of an hour, the results show that high quality Co 3 O 4 nanocrystals can be synthesized at 200 °C. Decrease of the hold temperature leads to deteriorated crystallinity and incomplete reaction.
SYNTHESIS AND CHARACTERIZATON OF HIGH-QUALITY GaN NANORODS WITH TRIANGULAR CROSS SECTION
Authors: WU X. X. , FU J. J. , YANG Y. , WU Q. , HU Z. , CHEN Y. , LU Y. N.
Published: August 2005

High-quality GaN nanorods with triangular cross section were synthesized via a simple chloride-assisted vapor phase epitaxy method. High-resolution transmission electron microscopic observations show that the synthesized GaN nanorods are single crystal with wurtzite hexagonal structure. Raman and photoluminescence measurements were also carried out to study the optical properties of the as-prepared GaN nanorods, which suggests the potential applications in optoelectronic devices.
MORPHOLOGICAL CHARACTERISTIC AND PHOTOLUMINESCENCE PROPERTY OF ZnO TETRAPOD NANOSTRUCTURES PREPARED BY SELF-SUBSTRATE METHOD
Authors: CHENG YAO , WAN JIAN-GUO , LI ZHENLIN , LIU HONGWEI , ZHENG CHANGLIN , HAN MIN
Published: August 2005

A self-substrate method is developed for the synthesis of the novel ZnO tetrapod nanostructures in this work. Electron Microscopy shows that there exists a sudden change in the width of each leg of the tetrapod nanostructures. High-resolution transmission electron microscopy (HRTEM) and Selected area electron diffraction (SAED) reveal that the tetrapod nanostructures have the same growth direction [0001] along each leg. The photoluminescence spectra of the nanostructures have been measured and the ultraviolet emission at 388.5nm and green emission at 504.5nm are observed.
STUDY OF THERMAL STABILITY OF FULLERENES BY MOLECULAR DYNAMICS
Authors: ZHANG WEI , XU ZIJIAN , ZHU ZHIYUAN
Published: August 2005

The thermal stability of fullerene C20, C26, C36 and C60 is studied using Molecular Dynamics (MD) simulation based on Brenner potential in this work. Lindemann's relative root-mean-square (rms) bond-length fluctuation is used to monitor the behavior of the structural and thermal properties. The results show that the rms bond-length fluctuation becomes scattered points at relative high tempereture, which is caused by different isomerization transitions. Larger fullerenes are found to be more stable than small ones. The results are compared with those from MD simulation based on TLHT potential. Mechanic stability of fullerene C20 is also studied.
TIME AND ENERGY-RESOLVED THERMIONIC EMISSION IN CARBON CLUSTERS
Authors: BORDAS C. , BAGUENARD B. , CLIMEN B. , LÉPINE F. , PAGLIARULO F. , LEBEAULT M. A. , WILLS J.
Published: August 2005

We present experimental measurements of time-dependent photoelectron spectra observed in thermionic emission of small carbon cluster anions and C 60 fullerenes. The combination of photoelectron velocity-map imaging with time-gated detection allowed to resolve delayed electron emission at different stages of the emission process. This unique capability allows us to analyze pure thermionic energy spectra under well-defined conditions. Experimental spectra are analyzed within the framework of the detailed balance theory.
ELECTRON SPIN RELAXATION OF A@C60
Authors: ZENG X. H. , ZHOU P. X. , GU B. , RUDA H. E. , QIAO BI
Published: August 2005

The electron spin decoherence in endohedral fullerene A@C 60 is studied at low temperature using master equation under the Markov approximation. At lower magnetic field the polarization decay occurs with form e-(t/T1)2 consitent with previous reports having decays of the order of ℏ/A, and the relationship [Formula: see text] is satisfied. For the case of A@C 60 (A = N,P ) endohedral fullerenes, the decay times on the order of tens of ns are calculated. For a strong external magnetic field, polarization strongly depends on the external magnetic field, the decay time is suppressed.
THE QUANTUM TUNNELLING BETWEEN TWO-COMPONENT BOSE–EINSTEIN CONDENSATES IN A DOUBLE-WELL CONFIGURATION
Authors: ZHANG GUO-FENG
Published: August 2005

We examine in terms of exact solutions of the time-dependent Schrödinger equation, the quantum tunnelling process in Bose–Einstein condensates of two interacting species trapped in a double well configuration. Based on the two series of time-dependent SU(2) gauge transformations, we diagonalize the Hamilton operator and obtain analytic time-evolution formulas of the population imbalance and the berry phase. The particle population imbalance [Formula: see text] of species A between the two wells is studied analytically.
Evolving the Psychological Mechanisms for Cooperation
Authors: Stevens Jeffrey R. , Cushman Fiery A. , Hauser Marc D.
Published: August 2005

▪ Abstract  Cooperation is common across nonhuman animal taxa, from the hunting of large game in lions to the harvesting of building materials in ants. Theorists have proposed a number of models to explain the evolution of cooperative behavior. These ultimate explanations, however, rarely consider the proximate constraints on the implementation of cooperative behavior. Here we review several types of cooperation and propose a suite of cognitive abilities required for each type to evolve. We propose that several types of cooperation, though theoretically possible and functionally adaptive, have not evolved in some animal species because of cognitive constraints. We argue, therefore, that future modeling efforts and experimental investigations into the adaptive function of cooperation in animals must be grounded in a realistic assessment of the psychological ingredients required for cooperation. Such an approach can account for the puzzling distribution of cooperative behaviors across taxa, especially the seemingly unique occurrence of cooperation observed in our own species.
Attitudes and Persuasion
Authors: Crano William D. , Prislin Radmila
Published: August 2005

Study of attitudes and persuasion remains a defining characteristic of contemporary social psychology. This review outlines recent advances, with emphasis on the relevance of today's work for perennial issues. We reiterate the distinction between attitude formation and change, and show its relevance for persuasion. Single- and dual-process models are discussed, as are current views on dissonance theory. Majority and minority influence are scrutinized, with special emphasis on integrative theoretical innovations. Attitude strength is considered, and its relevance to ambivalence and resistance documented. Affect, mood, and emotion effects are reviewed, especially as they pertain to fear arousal and (un)certainty. Finally, we discuss attitude-behavior consistency, perhaps the reason for our interest in attitudes in the first place, with emphasis on self-interest and the theory of planned behavior. Our review reflects the dynamism and the reach of the area, and suggests a sure and sometimes rapid accumulation of knowledge and understanding.
Activation of RNA metabolism-related genes in mouse but not human tissues deficient in SMN
Authors: Olaso Robert , Joshi Vandana , Fernandez Julien , Roblot Natacha , Courageot Sabrina , Bonnefont Jean Paul , Melki Judith
Published: August 2005

Mutations of the survival of motor neuron gene ( SMN1) are responsible for spinal muscular atrophies (SMA), a frequent recessive autosomal motor neuron disease. SMN is involved in various processes including RNA metabolism. However, the molecular pathway linking marked deficiency of SMN to SMA phenotype remains unclear. Homozygous deletion of murine Smn exon 7 directed to neurons or skeletal muscle causes severe motor axonal or myofiber degeneration, respectively. With the use of cDNA microarrays, expression profiles of 8,400 genes were analyzed in skeletal muscle and spinal cord of muscular and neuronal mutants, respectively, and compared with age-matched controls. A high proportion of genes (20 of 429, 5%) was involved in pre-mRNA splicing, ribosomal RNA processing, or RNA decay, and 18 of them were upregulated in mutant tissues. By analyzing other neuromuscular disorders, we showed that most of them (14 of 18) were specific to the SMN defect. Quantitative PCR analysis of these transcripts showed that gene activation was an early adaptive response to the lack but not reduced amount of full-length SMN in mouse mutant tissues. In human SMA tissues, activation of this program was not observed, which could be ascribed to the reduction but not the absence of full-length SMN.
Overweight and Obesity among Schoolchildren in Sana’a City, Yemen
Authors: Raja’a Yahia Ahmed , Bin Mohanna Mabrook Aidah
Published: August 2005

Aim: To estimate the prevalence of overweight and obesity among schoolchildren in Sana’a City (Yemen) and to examine the association with lifestyle and some socioeconomic factors. Methods: A cross-sectional study was done in public and private schools in Sana’a City during 2002–2003. We selected 1,253 students by the multistage random sampling technique. Weights and heights were measured to calculate body mass index (BMI = weight/height2). Data about age, sex, education level of the parents, food consumption and lifestyle was also collected. Results: The mean age of the children was 12.6 ± 2 years. Overweight was 6.2% and obesity was 1.8%. The prevalence of overweight and obesity was higher among private schoolchildren (p<000), females (p = 0.002), children with a sedentary lifestyle (p = 0.001) and children with a family history of obesity (p = 0.013). Also there is a positive association of overweight/obesity with the education level of the parents (p = 0.013 for the father and p = 0.19 for the mother) and consumption of unhealthy foods. Conclusion: Prevalence of overweight and obesity is low and positively associated with the education level of the father, private schooling, sedentary lifestyle, and with students who took unhealthy meals.
KCNH2
-K897T Is a Genetic Modifier of Latent Congenital Long-QT Syndrome
Authors: Crotti Lia , Lundquist Andrew L. , Insolia Roberto , Pedrazzini Matteo , Ferrandi Chiara , De Ferrari Gaetano M. , Vicentini Alessandro , Yang Ping , Roden Dan M. , George Alfred L. , Schwartz Peter J.
Published: August 2005

Background—

Clinical heterogeneity among patients with long-QT syndrome (LQTS) sharing the same disease-causing mutation is usually attributed to variable penetrance. One potential explanation for this phenomenon is the coexistence of modifier gene alleles, possibly common single nucleotide polymorphisms, altering arrhythmia susceptibility. We demonstrate this concept in a family segregating a novel, low-penetrant
KCNH2
mutation along with a common single nucleotide polymorphism in the same gene.

Methods and Results—

The proband is a 44-year-old white woman with palpitations associated with presyncope since age 20, who presented with ventricular fibrillation and cardiac arrest. Intermittent QT prolongation was subsequently observed (max QTc, 530 ms), and LQT2 was diagnosed after the identification of a missense
KCNH2
mutation (A1116V) altering a conserved residue in the distal carboxyl-terminus of the encoded HERG protein. The proband also carried the common
KCNH2
polymorphism K897T on the nonmutant allele. Relatives who carried A1116V without K897T were asymptomatic, but some exhibited transient mild QTc prolongation, suggesting latent disease. Heterologous expression studies performed in cultured mammalian cells and using bicistronic vectors linked to different fluorescent proteins demonstrated that coexpression of A1116V with K897T together resulted in significantly reduced current amplitude as compared with coexpression of either allele with WT-HERG. Thus, the presence of
KCNH2
-K897T is predicted to exaggerate the
I

Kr

reduction caused by the A1116V mutation. These data explain why symptomatic LQTS occurred only in the proband carrying both alleles.

Conclusions—

We have provided evidence that a common
KCNH2
polymorphism may modify the clinical expression of a latent LQT2 mutation. A similar mechanism may contribute to the risk for sudden death in more prevalent cardiac diseases.
The corrupt organization
Authors: Levine David P.
Published: August 2005

This article explores the psychic meaning of corruption understood as an attack on norms of conduct in organizations. The primary focus is on why individuals fail to become securely attached to norms, and on the part played in this failure by certain key features of corruption: greed, arrogance, a sense of personal entitlement, the idea of virtue as personal loyalty, and the inability to distinguish between organizational and personal ends. The essay considers the moral dimension of the problem and suggests that conduct normally interpreted as corrupt often expresses a powerful attachment to primitive moral thinking rather than a rejection of morality.
Commentary: Pensions and Pension Policy
Authors: Broadbent Simon , van de Ven Justin , Weale Martin
Published: August 2005

The Pensions Commission is to make its recommendations on pension policy reform later this year, in the light of comments on the challenges identified in its first Report. Widespread agreement on the need for such reform is partly a consequence of problems which have already surfaced, such as the insolvency of some pension schemes, moves to curtail benefits and mis-selling scandals. However the main impetus comes from the fact, clearly demonstrated by the Pensions Commission (2004), that for pensioners to enjoy the current relative standard of living in fifty years time will require people either to (i) retire later (ii) save more; or (iii) pay higher taxes. In the Commission's view the key issues are to find a consensus on the appropriate combination of these three, or of the alternative of lower pensioner incomes, and to find ways of bringing about such an outcome. We focus on aspects of such a reform and suggest one measure which could be implemented without further ado.
Global Realignment of Exchange Rates: East Asia's Dilemma
Authors: Al-Eyd Ali , Barrell Ray , Choy Amanda
Published: August 2005

Over the past year East Asia has featured prominently in the international debate over the widening global economic imbalances. In particular, China has attracted much attention for the nature of its currency regime and its large trade surplus. Until recently, China pursued a strict policy of tightly fixing the value of the renminbi against the US dollar and, as a result, Chinese exports have remained highly competitive while the US current account position has deteriorated markedly. A substantial widening of China's trade surplus in the first half of this year has sparked a great deal of criticism from the US regarding China's exchange rate regime. Protectionist threats from the US and growing domestic imbalances in the Chinese economy have succeeded in prompting the Chinese authorities to reform their exchange rate regime. On 21 July, Chinese authorities announced the abandonment of the longstanding US dollar peg in favour of a managed system where the renminbi is fixed against a basket of currencies. The specifics of this new exchange rate regime provide ample scope for further renminbi appreciation; however, this will be an orderly and drawn-out process dictated by both economic and market conditions.
A randomized trial of mail vs. telephone invitation to a community-based cardiovascular health awareness program for older family practice patients [ISRCTN61739603]
Authors: Karwalajtys Tina , Kaczorowski Janusz , Chambers Larry W , Levitt Cheryl , Dolovich Lisa , McDonough Bea , Patterson Christopher , Williams James E
Published: August 2005

Background

Family physicians can play an important role in encouraging patients to participate in community-based health promotion initiatives designed to supplement and enhance their in-office care. Our objectives were to determine effective approaches to invite older family practice patients to attend cardiovascular health awareness sessions in community pharmacies, and to assess the feasibility and acceptability of a program incorporating invitation by physicians and feedback to physicians.

Methods

We conducted a prospective randomized trial with 1 family physician practice and 5 community pharmacies in Dundas, Ontario. Regular patients 65 years or older (n = 235) were randomly allocated to invitation by mail or telephone to attend pharmacy cardiovascular health awareness sessions led by volunteer peer health educators. A health record review captured blood pressure status, monitoring and control. At the sessions, volunteers helped patients to measure blood pressure using in-store machines and a validated portable device (BPM-100), and recorded blood pressure readings and self-reported cardiovascular risk factors. We compared attendance rates in the mail and telephone invitation groups and explored factors potentially associated with attendance.

Results

The 119 patients invited by mail and 116 patients contacted by telephone had a mean age of 75.7 (SD, 6.4) years and 46.8% were male. Overall, 58.3% (137/235) of invitees attended a pharmacy cardiovascular health awareness session. Patients invited by telephone were more likely to attend than those invited by mail (72.3% vs. 44.0%, OR 3.3; 95%CI 1.9–5.7; p < 0.001).

Conclusion

While the attendance in response to a telephone invitation was higher, response to a single letter was substantial. Attendance rates indicated considerable interest in community-based cardiovascular health promotion activities. A large-scale trial of a pharmacy cardiovascular health awareness program for older primary care patients is feasible.
In B-CLL, the codon 72 polymorphic variants of p53 are not related to drug resistance and disease prognosis
Authors: Sturm Isrid , Bosanquet Andrew G , Hummel Michael , Dörken Bernd , Daniel Peter T
Published: August 2005

Background

A common sequence polymorphism at codon 72 of the p53 gene encoding either arginine or proline was recently shown to be functionally relevant for apoptosis induction in vitro. In B-type chronic lymphocytic leukemia (B-CLL), p53 gene mutations occur in a subset of patients and are associated with impaired survival and drug resistance. Here, we address the functional relevance of the codon 72 single nucleotide (SNP) polymorphism for cell death sensitivity following exposure to clinically employed cytotoxic drugs and γ-irradiation.

Methods

138 B-CLL samples were analysed by SSCP-PCR and sequencing for single nucleotide polymorphism at codon 72 of the p53 gene. The in vitro cytotoxicity assay (DiSC-assay) was performed with 7 drugs (chlorambucil, mafosfamide, fludarabine phosphate, methylprednisolone, doxorubicin, vincristine) or γ-irradiation.

Results

Of the138 B-CLL samples, 9 samples were homozygous for proline (Pro/Pro), 78 samples homozygous for arginine (Arg/Arg), and 49 samples heterozygous (Arg/Pro). No differences were found for patient survival and cell death triggered by 7 cytotoxic drugs or γ-irradiation.

Conclusion

These data indicate that polymorphic variants of p53 codon 72 are not clinically relevant for apoptosis induction or patient survival in B-CLL.
A case repot of Merkel cell carcinoma on chronic lymphocytic leukemia: differential diagnosis of coexisting lymphadenopathy and indications for early aggressive treatment
Authors: Papageorgiou KI , Kaniorou-Larai MG
Published: August 2005

Background

Chronic lymphocytic leukemia (CLL) is a monoclonal disorder, characterized by a progressive proliferation of functionally incompetent B lymphocytes. There is increased evidence of association between CLL and skin cancers, including the uncommon Merkel cell carcinoma (MCC).

Case presentation

A case report of an 84-year old male, who presented with an aggressively recurrent form of MCC on the lower lip, on the background of an 8-year history of untreated CLL. During the recurrences of MCC, coexisting regional lymphadenopathy, posed a problem in the differential diagnosis and treatment of lymph node involvement. Histopathology and immunoistochemistry showed that submandibular lymphadenopathy coexisting with the second recurrence of MCC, was due to B-cell small lymphocytic lymphoma. The subsequent and more aggressive recurrence of the skin tumor had involved the superficial and deep cervical lymph nodes. Surgical excision followed by involved field radiation therapy has been proven effective for both malignancies.

Conclusion

MCC has a high incidence of regional lymphadenopathy at presentation (12–45%) and even when it arises on the background of chronic leucemia, lymphadenopathy at presentation should be managed agressively with elective lymph node dissection. We overview the postulated correlation between Merkel tumor and CCL, the differential diagnosis of regional lymphadenopathy during the recurrences of the skin tumor and the strategies of treatment
Phosphorylation states of cell cycle and DNA repair proteins can be altered by the nsSNPs
Authors: Savas Sevtap , Ozcelik Hilmi
Published: August 2005

Background

Phosphorylation is a reversible post-translational modification that affects the intrinsic properties of proteins, such as structure and function. Non-synonymous single nucleotide polymorphisms (nsSNPs) result in the substitution of the encoded amino acids and thus are likely to alter the phosphorylation motifs in the proteins.

Methods

In this study, we used the web-based NetPhos tool to predict candidate nsSNPs that either introduce or remove putative phosphorylation sites in proteins that act in DNA repair and cell cycle pathways.

Results

Our results demonstrated that a total of 15 nsSNPs (16.9%) were likely to alter the putative phosphorylation patterns of 14 proteins. Three of these SNPs (CDKN1A-S31R, OGG1-S326C, and XRCC3-T241M) have already found to be associated with altered cancer risk. We believe that this set of nsSNPs constitutes an excellent resource for further molecular and genetic analyses.

Conclusion

The novel systematic approach used in this study will accelerate the understanding of how naturally occurring human SNPs may alter protein function through the modification of phosphorylation mechanisms and contribute to disease susceptibility.
Expression and subcellular localization of aquaporin water channels in the polarized hepatocyte cell line, WIF-B
Authors: Gradilone Sergio A , Tietz Pamela S , Splinter Patrick L , Marinelli Raúl A , LaRusso Nicholas F
Published: August 2005

Background

Recent data suggest that canalicular bile secretion involves selective expression and coordinated regulation of aquaporins (AQPs), a family of water channels proteins. In order to further characterize the role of AQPs in this process, an in vitro cell system with retained polarity and expression of AQPs and relevant solute transporters involved in bile formation is highly desirable. The WIF-B cell line is a highly differentiated and polarized rat hepatoma/human fibroblast hybrid, which forms abundant bile canalicular structures. This cell line has been reported to be a good in vitro model for studying hepatocyte polarity.

Results

Using RT-PCR, immunoblotting and confocal immunofluorescence, we showed that WIF-B cells express the aquaporin water channels that facilitate the osmotically driven water movements in the liver, i.e. AQP8, AQP9, and AQP0; as well as the key solute transporters involved in the generation of canalicular osmotic gradients, i.e., the bile salt export pump Bsep, the organic anion transporter Mrp2 and the chloride bicarbonate exchanger AE2. The subcellular localization of the AQPs and the solute transporters in WIF-B cells was similar to that in freshly isolated rat hepatocytes and in intact liver. Immunofluorescent costaining studies showed intracellular colocalization of AQP8 and AE2, suggesting the possibility that these transporters are expressed in the same population of pericanalicular vesicles.

Conclusion

The hepatocyte cell line WIF-B retains the expression and subcellular localization of aquaporin water channels as well as key solute transporters for canalicular bile secretion. Thus, these cells can work as a valuable tool for regulatory and mechanistic studies of the biology of bile formation.
Insect sting allergy. A study from 1980 to 2003 of patients who started treatment with venom immunotherapy between 1980 and 1998
Authors: Haye Rolf , Døsen Liv Kari
Published: August 2005

Background

Previously we treated patients with insect sting allergy with venom immunotherapy (IT) using whole body insect extracts. From 1980 we changed to insect venoms. The purpose of this study was to analyse data from the patients in order to improve our treatment.

Methods

This is an open, single centre study on patients treated with venom IT 14 years or older with a history of a systemic allergic reaction to an insect sting, a positive skin prick test (SPT) or a positive RAST and willingness to comply with five years of IT. Clinical and laboratory data were registered prospectively at the start of IT and after five years of treatment until 2003 on patients who started IT between 1980 and 1998. Questionnaires were answered in 1989, 1993 and 2003. Statistical analysis was done with Pearson's chi square, Fisher's exact or the t-test.

Results

Of 315 patients treated, 44 were given bee, 248 common wasp and 23 both venoms. Of the common wasp sting incidents 5.5 % resulted in a severe allergic reaction (SAR) during adequate IT and 22% after cessation. Seventy-one per cent of the patients carried epinephrine. Precautionary steps were taken by 77% of the patients during or after inadequate IT. On or after adequate IT 83% felt completely or substantially safe. Surprisingly 29 % of those inadequately treated felt safer and 50% were satisfied with having had the opportunity to be treated. The SPT became negative in 68% of the wasp allergic patients after five years of adequate IT. Increased risk of experiencing SAR to a future sting in wasp allergic patients after cessation of adequate IT was significantly associated with a SAR due to IT during the rush regimen. SAR due to IT occurred very rarely during maintenance dosing.

Conclusion

Adequate venom IT is very effective while ongoing but somewhat less effective after cessation, while inadequate treatment gives poor results. More of our patients should complete five years of IT and some should continue IT. The type of reaction to IT during incremental dosing may be of help in deciding who should continue beyond five years. Maintenance IT may be taken over by the general physician.
Cerebrospinal fluid signs of neuronal damage after antiretroviral treatment interruption in HIV-1 infection
Authors: Gisslén Magnus , Rosengren Lars , Hagberg Lars , Deeks Steven G , Price Richard W
Published: August 2005

Background

The neurofilament is a major structural component of myelinated axons. Increased cerebrospinal fluid (CSF) concentrations of the light chain of the neurofilament protein (NFL) can serve as a sensitive indicator of central nervous system (CNS) injury. To assess whether interrupting antiretroviral treatment of HIV infection might have a deleterious effect on the CNS, we measured NFL levels in HIV-infected subjects interrupting therapy.

We identified subjects who had CSF HIV RNA concentrations below 50 copies/mL at the time combination antiretroviral therapy was interrupted, and for whom CSF samples were available before and after the interruption.

Results

A total of 8 subjects were studied. The median (range) CSF NFL level at baseline was <125 (<125–220) ng/L (normal <250 ng/L). All 8 subjects exhibited an increase in CSF and plasma HIV RNA after stopping therapy, accompanied by intrathecal immunoactivation as evidenced by CSF lymphocytic pleocytosis (7/8 patients) and increased CSF neopterin concentration (5/6 patients). Three subjects showed a consistent increase in CSF NFL, rising from <125 ng/L to a maximum of 880 (at day 148), 1,010 (day 58) and 10,930 ng/L (day 101). None exhibited new neurological symptoms or signs, or experienced functional deterioration during the period off treatment; of 5 who underwent brief quantitative neurological testing, none showed worsening performance.

Conclusion

These findings suggest that resurgence of active HIV replication may result in measurable, albeit subclinical, CNS injury. Further studies are needed to define the frequency and pathobiological importance of the increase in CSF NFL.
Bridging the Gap: a study of general nurses’ perceptions of patient advocacy in Ireland
Authors: O’Connor Tom , Kelly Billy
Published: August 2005

Advocacy has become an accepted and integral attribute of nursing practice. Despite this adoption of advocacy, confusion remains about the precise nature of the concept and how it should be enacted in practice. The aim of this study was to investigate general nurses’ perceptions of being patient advocates in Ireland and how they enact this role. These perceptions were compared with existing theory and research on advocacy in order to contribute to the knowledge base on the subject.

An inductive, qualitative approach was used for this study. Three focus group interviews with a total of 20 practising nurses were conducted with a sample representing different grades in a general hospital setting. Data analysis was carried out using elements of Strauss and Corbins’ approach to concept development. The findings indicate that the principal role of the nurse advocate is to act as an intermediary between the patient and the health care environment. The results highlight that advocacy did, however, result in nurses becoming involved in conflict and confrontation with others and that it could be detrimental to nurses both professionally and personally. It was also clear that when enacting advocacy, nurses distinguished between ‘clinical advocacy’ (acting directly for patients in the clinical environment) and organizational advocacy (acting on an organizational level for one or more patients).
To Be a Nurse or a Neighbour? a moral concern for psychiatric nurses living next door to individuals with a mental illness
Authors: Högberg Torbjörn , Magnusson Annabella , Lützén Kim
Published: August 2005

Several studies reveal that positive attitudes towards individuals with a mental illness are correlated with knowledge about mental illness. The aim of this study was to explore and describe psychiatric nurses’ experiences of living next to people with mental health problems. In addition, it sought to identify and describe how they handle situations arising in a neighbourhood where people with a mental illness live.

Two men and seven women participated in the study. The constant comparative method of grounded theory was used for data collection and analysis. The process of ‘behaving as a nurse or not’ was identified as a core category. Four subcategories were identified: ‘receiving involuntary information’, ‘to take action or not’, ‘behaving as a mediator in the neighbourhood’ and ‘the freedom of choice’. The findings show that psychiatric nurses with professional knowledge about mental illness have moral concerns about their role as nurses during their leisure time.

In conclusion, it is not obvious that psychiatric nurses want to live in the same neighbourhood as persons with a mental illness. However, this study shows that their knowledge about mental illness creates for them a moral dilemma consisting of a conflict between whether to care for these mentally ill persons or to preserve their own leisure time.
Sedation of Patients in Intensive Care Medicine and Nursing: ethical issues
Authors: Nortvedt Per , Kvarstein Gunnvald , Jønland Ingvild
Published: August 2005

This article focuses on the ethical aspects of medically-induced sedation and pain relief in intensive care medicine. The study results reported are part of a larger investigation of patients’ experiences of being sedated and receiving pain relief, and also families’ experiences of having a close relative under controlled sedation in an intensive care unit.

The study is based on qualitative in-depth interviews with nine nurses and six doctors working in intensive care and surgical units in a major Norwegian hospital. The textual data are interpreted according to Kvale’s method for analyzing qualitative data.

There are ethical problems regarding how to achieve an acceptable balance between a patient’s subjective well-being and the medical need for reduced sedation. The authors discuss whether some medical reasons for reduced sedation are ethically justifiable, given the actual medical knowledge available. The study also addresses the ethical consequences of reducing medically-induced sedation and the demands it puts on interdisciplinary co-operation and communication, as well as the importance of improving the quality of medical and nursing care.