bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental investigation of the electrical properties of atomic layer deposited hafnium-rich silicate films on n-type silicon
Authors: Dueñas S. , Castán H. , García H. , Bailón L. , Kukli K. , Ritala M. , Leskelä M. , Rooth M. , Wilhelmsson O. , Hårsta A.
Published: November 2006

This work examines the structural and electrical properties of HfSixOy film based metal-insulator-semiconductor capacitors by means of x-ray diffraction, x-ray photoelectron spectroscopy, capacitance-voltage (C-V), deep level transient spectroscopy, and conductance transient (G-t) techniques. Hafnium-rich silicate films were atomic layer deposited onto HF-etched or SiO2 covered silicon. Although as-deposited samples exhibit high interfacial state and disorder-induced gap state densities, a postdeposition thermal annealing in vacuum under N2 flow for 1min at temperatures between 600 and 730°C clearly improves the interface quality. Marked crystallization and phase separation occurred at 800°C, increasing the structural heterogeneity and defect density in the dielectric oxide layers.
The origin of contrast in the imaging of doped areas in silicon by slow electrons
Authors: Frank Luděk , Müllerová Ilona , Valdaitsev Dimitrii A. , Gloskovskii Andrei , Nepijko Sergei A. , Elmers Hans-Joachim , Schönhense Gerd
Published: November 2006

The importance of high resolution imaging of dopant contrast in semiconductor structures parallels the continuous increase in the degree of their integration and complexity and in the size of substrates. Some scanning electron microscopy modes show moderate contrast between differently doped areas, but its detailed interpretation remains questionable, in particular, as regards the measurement of the dopant concentration. Photoemission spectromicroscopy on silicon substrates with patterns of opposite-type dopants suggests that the p∕n contrast is primarily related to local differences in the absorption of hot electrons along their trajectory toward the surface. This explanation is also expected to be valid in the interpretation of image contrasts formed by secondary electrons or very slow backscattered electrons. Wide-field photoemission electron microscopy has proven itself a fast imaging method providing large p-n contrast and the prospect of high-level resolution.
Resonant effects in the strongly driven phase-biased Cooper-pair box
Authors: Shevchenko S. N. , Omelyanchouk A. N.
Published: November 2006

The time-averaged upper level occupation probability in a strongly driven two-level system is investigated, particularly its dependence on the driving amplitude x0 and frequency ω and the energy level separation ΔE. In contrast to the case of weak driving (x0⪡ΔE), when the positions of the resonances are almost independent of x0, in the case of the strong driving (x0∼ΔE) their positions are strongly amplitude dependent. These resonances are studied in a concrete system—the strongly driven phase-biased Cooper-pair box, which is considered to be weakly coupled to the tank circuit.
Single-mode room-temperature emission with a silicon rod lattice
Authors: Cluzel B. , Calvo V. , Charvolin T. , Picard E. , Noé P. , Hadji E.
Published: November 2006

The authors experimentally evidence an increase of light emission efficiency at room temperature in a silicon-on-insulator photonic crystal. The photonic crystal is made of a triangular lattice of silicon rods and operates as a single-mode light extractor. It exhibits a luminescence intensity two orders of magnitude higher than silicon-on-insulator substrate. In light of photoluminescence experiments, emission diagram measurements, and finite difference time domain calculations, they identify the different optical properties of the photonic crystal and they demonstrate the existence of at least a fivefold emission efficiency enhancement per surface unit.
Atomic scale observation of corner-voiding effects in advanced interconnects
Authors: Guedj C. , Barnes J. P. , Papon A. M.
Published: November 2006

Stress-induced voiding is a major reliability issue in advanced interconnects, and this detrimental phenomenon can be obtained at the corners of Cu lines even in the absence of twin or grain boundaries. An atomic scale description of this phenomenon is proposed. The high tensile strain gradient favors the motion of Cu atoms along the (111) planes. Hence the corners are progressively unfilled to minimize this strain gradient. This issue must be solved in view of further downscaling developments.
Characterization and field-emission properties of carbon nanotube arrays in nanoporous alumina template and on blank Si substrate
Authors: Yang Ching-Jung , Chen Chih , Shieh Jia-Min
Published: November 2006

Ordered carbon nanotube (CNT) arrays were synthesized within anodized aluminum oxide template by thermal decomposition of hydrocarbon precursor with hydrogen ambient at growth temperature as low as 500°C. Excess hydrogen in precursor mixture enables a steady supply of mobile hydrocarbon reactant which promotes facile solid-phase diffusion. The activation energy for CNT growth was determined to be 0.55eV, a number smaller than 1.02eV for similar precursor in nitrogen ambient. Moreover, CNTs grown in anodized aluminum oxide nanopores in this low temperature process were found to exhibit unusually high field-emission current of 100mA∕cm2 at 8V∕μm.
Characterization of the Si:H network during transformation from amorphous to micro- and nanocrystalline structures
Authors: Das Debajyoti , Bhattacharya Koyel
Published: November 2006

Optical, structural, and electrical characterizations of the Si:H network have been performed during its changes occurred by the increasing H2 dilution to the SiH4 ensemble in hot-wire chemical vapor deposition (HWCVD). A rapid structural transformation from a mostly amorphous phase to comprehensive micro/nanocrystallinity was attained at a relatively low H2 dilution, even at a low substrate temperature, because of the associated abundance of atomic H in HWCVD. However, elevated H2 dilution induces enormous polyhydrogenation and formation of lesser dense network full of voids, mostly around the tiny micro/nanocrystallites. This highly defective grain boundary zone provides high density of electronic trapping centers and contributes significantly to the transport of carriers. The overall electrical transport in the amorphous-micro-nano-crystalline heterogeneous Si:H network has been accounted in the framework of a three-phase model comprised of amorphous and crystalline (micro- and nano-) components while the grain boundary being the third phase, separately contributing to a potential energy barrier in between. The three-phase model to the electrical phenomena of nanocrystalline structures convincingly explains the dual activation energies arising in the electrical conduction with distinguishably different temperature dependent behaviors from that occurs in the conventional amorphous matrix.
Wave packet interferometry and quantum state reconstruction by acousto-optic phase modulation
Authors: Tekavec Patrick F. , Dyke Thomas R. , Marcus Andrew H.
Published: November 2006

Studies of wave packet dynamics often involve phase-selective measurements of coherent optical signals generated from sequences of ultrashort laser pulses. In wave packet interferometry (WPI), the separation between the temporal envelopes of the pulses must be precisely monitored or maintained. Here we introduce a new (and easy to implement) experimental scheme for phase-selective measurements that combines acousto-optic phase modulation with ultrashort laser excitation to produce an intensity-modulated fluorescence signal. Synchronous detection, with respect to an appropriately constructed reference, allows the signal to be simultaneously measured at two phases differing by 90°. Our method effectively decouples the relative temporal phase from the pulse envelopes of a collinear train of optical pulse pairs. We thus achieve a robust and high signal-to-noise scheme for WPI applications, such as quantum state reconstruction and electronic spectroscopy. The validity of the method is demonstrated, and state reconstruction is performed, on a model quantum system—atomic Rb vapor. Moreover, we show that our measurements recover the correct separation between the absorptive and dispersive contributions to the system susceptibility.
Induced emission cross sections of near-stoichiometric LiNbO3:Mg, Nd
Authors: Sekita Masami , Nakamura Masaru , Watanabe Akiteru , Takekawa Shunji , Kitamura Kenji
Published: November 2006

Optical absorption and emission spectra are measured on Nd3+ ion in near-stoichiometric LiNbO3 single crystals codoped with MgO. From the decomposition of the nonpolarized spectra, the Stark splitting scheme is established for 2wt% Nd3+ ion in the near-stoichiometric LiNbO3:Mg, Nd system. The induced emission cross sections are calculated to be 2.70×10−19 and 5.57×10−20cm2 for the π and σ polarizations, respectively, based on the decomposition of the polarized spectra. These values agree well with the reported values of 1.8×10−19 and 5.1×10−20cm2 for the π and σ polarizations of the conventional congruent-melt composition crystal through the branching ratio of emission spectra despite the different approach of calculations and difference in the near-stoichiometric and congruent-melt compositions. This fact shows that the slight difference in the host composition does not affect the cross section. The population inversion threshold is calculated to be 2.0×1016 for the Nd(2wt%) near-stoichiometric LiNbO3:Mg, Nd in the π polarization, the value of which is almost the same as that of 1.5×1016 for Nd:Y3Al5O12, one of the representative laser materials.
Pump-probe and pump-deplete-probe spectroscopies on carotenoids with N=9–15 conjugated bonds
Authors: Buckup Tiago , Savolainen Janne , Wohlleben Wendel , Herek Jennifer L. , Hashimoto Hideki , Correia Ricardo R. B. , Motzkus Marcus
Published: November 2006

A series of all-trans-carotenoids with N=9, 13, and 15 conjugated bonds has been studied by pump-probe and pump-deplete-probe spectroscopies to obtain a systematic analysis of the energy flow between the different electronic states. The ultrafast dynamics in the carotenoids are initialized by excitation to the S2 state and subsequently manipulated by an additional depletion pulse in the near-IR spectral range. The changes in the dynamics after depletion of the excited state population allowed differentiation of the excited state absorption into two components, a major one corresponding to the well known S1 state and the small contribution on the red wing of the S0-S2 absorption band originating from the hot ground state. We found no evidence for an additional electronically excited state, usually called S*. Instead, a deactivation mechanism that includes the hot ground state supports the observed results nicely in the framework of a simple three state model (S2, S1, and S0).
Enhanced elastic interactions between conical quantum dots
Authors: Gill Simon P. A.
Published: November 2006

An analytical model for the elastic energy of a system of conical heteroepitaxial quantum dots of finite slope is presented. An expression for the surface tractions at the dot-substrate interface is proposed. This includes a singularity in the stress field at the perimeter of the dot. The strength of this singularity increases as the slope of the dot increases. This dramatically enhances the elastic interaction between dots and the metastability of a quantum dot array. This could help explain the stability of bimodal island size distributions observed in some quantum dot systems.
Determination of carrier density of ZnO nanowires by electrochemical techniques
Authors: Mora-Seró Iván , Fabregat-Santiago Francisco , Denier Benjamin , Bisquert Juan , Tena-Zaera Ramón , Elias Jamil , Lévy-Clément Claude
Published: November 2006

The carrier density of ZnO nanowires has been determined by means of electrochemical impedance spectroscopy. A model taking into account the geometry of ZnO nanowires has been developed and the differences with the standard flat model, as curved Mott-Schottky plots, are discussed. The as-grown electrodeposited samples present a high donor density of 6.2×1019cm−3, dramatically reduced by two orders of magnitude after an annealing in air at 450°C during 1h. The results show that the surface of the ZnO nanowires is active; therefore this system appears as a useful structure to support a functionalized nanostructured devices.
Application of the optimized Baxter model to the hard-core attractive Yukawa system
Authors: Prinsen Peter , Pàmies Josep C. , Odijk Theo , Frenkel Daan
Published: November 2006

We perform Monte Carlo simulations on the hard-core attractive Yukawa system to test the optimized Baxter model that was introduced by Prinsen and Odijk [J. Chem. Phys. 121, 6525 (2004)] to study a fluid phase of spherical particles interacting through a short-range pair potential. We compare the chemical potentials and pressures from the simulations with analytical predictions from the optimized Baxter model. We show that the model is accurate to within 10% over a range of volume fractions from 0.1 to 0.4, interaction strengths up to three times the thermal energy, and interaction ranges from 6% to 20% of the particle diameter, and performs even better in most cases. We furthermore establish the consistency of the model by showing that the thermodynamic properties of the Yukawa fluid computed via simulations may be understood on the basis of one similarity variable, the stickiness parameter defined within the optimized Baxter model. Finally, we show that the optimized Baxter model works significantly better than an often used, naive method determining the stickiness parameter by equating the respective second virial coefficients based on the attractive Yukawa and Baxter potentials.
Marangoni effect and heat pipe dry-out
Authors: Savino R. , Paterna D.
Published: November 2006

In this study, Marangoni flows effects on heat pipe performances are explored. Recent results dealing with computations of the meniscus shape in a wedge are extended to take into account a nonzero flow rate, caused by the liquid mass lost at the evaporator and supplied by the vapor condensation at the opposite side. Moreover “inverse Marangoni effects” (prevailing in some binary mixtures) are investigated. Dry-out conditions have been computed for different flow rates and surface tension gradients. Results show that while dry-out occurrence is anticipated by the usual Marangoni effect, as illustrated by Yang and Homsy [Phys. Fluids18, 042107 (2006)], an inverse Marangoni effect is beneficial and dry-out conditions are delayed at much larger heating rates.
Studies Towards CD Intermediates of Vitamin D3: Enolate Trapping of Ketone Enolates With Novel Sulfonyl Electrophiles
Authors: Loughlin WA , Haynes RK , Sitpaseuth S
Published: November 2006

The phenyl sulfonyl electrophile (3) reacts with the titanium enol of cyclopentanone to provide an alkylated adduct (8). Conversion into the model hydrindanol (11) [71% from (8)] was readily effected by hydrogenation, and subsequent annelation with potassium t- butoxide . Application of the model study to the synthesis of a CD intermediate, through the use of the conjugate addition of lithiated butenyldiphenylphosphine oxide (2) to 2-methylcyclopentenone (1), followed by trapping with the electrophile (3), was not straightforward. Hydrogenation of the adduct (12) proceeded with loss of stereoselectivity. Instead, use of the alternative electrophiles, the α-( trimethylsilyl ) butadienyl sulfones (18) and (19), gave the desilylated unsaturated adduct (22). Hydrogenation of (22) proceeded smoothly to give the saturated adduct (15) as one isomer. However, in contrast to the model study, attempts at cyclization of the CD intermediate precursor (15) were unsuccessful.
Gibbs Transfer Energies and Solvent Transport Numbers of Some Copper(II) Salts in Methanol-Dimethylformamide Mixtures
Authors: Varghese AV , Kalidas C , Singh P , Hefter G
Published: November 2006

Standard Gibbs energies of transfer have been determined for copper(II) iodate, benzoate and formate at 30°C in methanol- dimethylformamide mixtures by solubility measurements. Single-ion transfer energies were obtained by using the negligible liquid junction potential assumption, along with relevant literature data, and are in excellent agreement with values estimated from the reference electrolyte ( tatb ) assumption. The results obtained indicate that all of these salts are heteroselectively solvated in these mixtures, with Cu2+ being preferentially solvated by dmf and the anions by MeOH. This model is consistent with calculations based on the quasi-lattice quasi-chemical theory of Marcus and with solvent transport numbers obtained from e.m.f . measurements.
Crystal Structure of Tetraethylammonium Bromopentacarbonyltungstate(0)
Authors: Whyte T , Williams GA
Published: November 2006

The crystal structure of tetraethylammonium bromopentacarbonyltungstate (0), [NEt4] [W(CO)5Br], has been determined by single-crystal X-ray diffraction methods at 22�1°C. Crystals are tetragonal, space group P4/n, with a 9.206(2), c 10.484(2) Ǻ, and Z 2. Full-matrix least-squares refinement gave a final R value of 0.034 for 820 independent reflections. The [W(CO)5Br]- anion possesses exact C4v symmetry, with bond lengths W-Br 2.736(1), W-COtrans 1.93(1) and W-COcis 2.034(6) Ǻ.
Synthesis of a Novel Diterpenoid Rearrangement Product
Authors: Bendall JG , Cambie RC , Moratti SC , Rutledge PS , Woodgate PD
Published: November 2006

The two intermediates postulated in the rearrangement of the labdane diterpenoid octahy-dronaphthopyranone (2) into the octahydronaphthofuranone (4) have been synthesized and coupled, thereby providing support for a previously proposed rearrangement mechanism.
Apparent cooperativity in the folding of multidomain proteins depends on the relative rates of folding of the constituent domains
Authors: Batey Sarah , Clarke Jane
Published: November 2006

Approximately 75% of eukaryotic proteins contain more than one so-called independently folding domain. However, there have been relatively few systematic studies to investigate the effect of interdomain interactions on protein stability and fewer still on folding kinetics. We present the folding of pairs of three-helix bundle spectrin domains as a paradigm to indicate how complex such an analysis can be. Equilibrium studies show an increase in denaturant concentration required to unfold the domains with only a single unfolding transition; however, in some cases, this is not accompanied by the increase in
m
value, which would be expected if the protein is a truly cooperative, all-or-none system. We analyze the complex kinetics of spectrin domain pairs, both wild-type and carefully selected mutants. By comparing these pairs, we are able to demonstrate that equilibrium data alone are insufficient to describe the folding of multidomain proteins and to quantify the effects that one domain can have on its neighbor.
Human cancers express a mutator phenotype
Authors: Bielas Jason H. , Loeb Keith R. , Rubin Brian P. , True Lawrence D. , Loeb Lawrence A.
Published: November 2006

Cancer cells contain numerous clonal mutations, i.e., mutations that are present in most or all malignant cells of a tumor and have presumably been selected because they confer a proliferative advantage. An important question is whether cancer cells also contain a large number of random mutations, i.e., randomly distributed unselected mutations that occur in only one or a few cells of a tumor. Such random mutations could contribute to the morphologic and functional heterogeneity of cancers and include mutations that confer resistance to therapy. We have postulated that malignant cells exhibit a mutator phenotype resulting in the generation of random mutations throughout the genome. We have recently developed an assay to quantify random mutations in human tissue with unprecedented sensitivity. Here, we report measurements of random single-nucleotide substitutions in normal and neoplastic human tissues. In normal tissues, the frequency of spontaneous random mutations is exceedingly low, less than 1 × 10
−8
per base pair. In contrast, tumors from the same individuals exhibited an average frequency of 210 × 10
−8
per base pair, an elevation of at least two orders of magnitude. Our data document tumor heterogeneity at the single-nucleotide level, indicate that accelerated mutagenesis prevails late into tumor progression, and suggest that elevation of random mutation frequency in tumors might serve as a novel prognostic indicator.
Human SHPRH is a ubiquitin ligase for Mms2–Ubc13-dependent polyubiquitylation of proliferating cell nuclear antigen
Authors: Unk Ildiko , Hajdú Ildikó , Fátyol Károly , Szakál Barnabás , Blastyák András , Bermudez Vladimir , Hurwitz Jerard , Prakash Louise , Prakash Satya , Haracska Lajos
Published: November 2006

Human SHPRH gene is located at the 6q24 chromosomal region, and loss of heterozygosity in this region is seen in a wide variety of cancers. SHPRH is a member of the SWI/SNF family of ATPases/helicases, and it possesses a C
3
HC
4
RING motif characteristic of ubiquitin ligase proteins. In both of these features, SHPRH resembles the yeast Rad5 protein, which, together with Mms2–Ubc13, promotes replication through DNA lesions via an error-free postreplicational repair pathway. Genetic evidence in yeast has indicated a role for Rad5 as a ubiquitin ligase in mediating the Mms2–Ubc13-dependent polyubiquitylation of proliferating cell nuclear antigen. Here we show that SHPRH is a functional homolog of Rad5. Similar to Rad5, SHPRH physically interacts with the Rad6–Rad18 and Mms2–Ubc13 complexes, and we show that SHPRH protein is a ubiquitin ligase indispensable for Mms2–Ubc13-dependent polyubiquitylation of proliferating cell nuclear antigen. Based on these observations, we predict a role for SHPRH in promoting error-free replication through DNA lesions. Such a role for SHPRH is consistent with the observation that this gene is mutated in a number of cancer cell lines, including those from melanomas and ovarian cancers, which raises the strong possibility that SHPRH function is an important deterrent to mutagenesis and carcinogenesis in humans.
SCFCdc4-mediated Degradation of the Hac1p Transcription Factor Regulates the Unfolded Protein Response inSaccharomyces cerevisiae
Authors: Pal Bhupinder , Chan Nickie C. , Helfenbaum Leon , Tan Kaeling , Tansey William P. , Gething Mary-Jane
Published: November 2006

The Saccharomyces cerevisiae basic leucine zipper transcription factor Hac1p is synthesized in response to the accumulation of unfolded polypeptides in the lumen of the endoplasmic reticulum (ER), and it is responsible for up-regulation of ∼5% of all yeast genes, including ER-resident chaperones and protein-folding catalysts. Hac1p is one of the most short-lived yeast proteins, having a half-life of ∼1.5 min. Here, we have shown that Hac1p harbors a functional PEST degron and that degradation of Hac1p by the proteasome involves the E2 ubiquitin-conjugating enzyme Ubc3/Cdc34p and the SCFCdc4E3 complex. Consistent with the known nuclear localization of Cdc4p, rapid degradation of Hac1p requires the presence of a functional nuclear localization sequence, which we demonstrated to involve basic residues in the sequence29RKRAKTK35. Two-hybrid analysis demonstrated that the PEST-dependent interaction of Hac1p with Cdc4p requires Ser146 and Ser149. Turnover of Hac1p may be dependent on transcription because it is inhibited in cell mutants lacking Srb10 kinase, a component of the SRB/mediator module of the RNA polymerase II holoenzyme. Stabilization of Hac1p by point mutation or deletion, or as the consequence of defects in components of the degradation pathway, results in increased unfolded protein response element-dependent transcription and improved cell viability under ER stress conditions.
Cdk5 Modulation of Mitogen-activated Protein Kinase Signaling Regulates Neuronal Survival
Authors: Zheng Ya-Li , Li Bing-Sheng , Kanungo Jyotshna , Kesavapany Sashi , Amin Niranjana , Grant Philip , Pant Harish C.
Published: November 2006

Cdk5, a cyclin-dependent kinase, is critical for neuronal development, neuronal migration, cortical lamination, and survival. Its survival role is based, in part, on “cross-talk” interactions with apoptotic and survival signaling pathways. Previously, we showed that Cdk5 phosphorylation of mitogen-activated protein kinase kinase (MEK)1 inhibits transient activation induced by nerve growth factor (NGF) in PC12 cells. To further explore the nature of this inhibition, we studied the kinetics of NGF activation of extracellular signal-regulated kinase (Erk)1/2 in cortical neurons with or without roscovitine, an inhibitor of Cdk5. NGF alone induced an Erk1/2-transient activation that peaked in 15 min and declined rapidly to baseline. Roscovitine, alone or with NGF, reached peak Erk1/2 activation in 30 min that was sustained for 48 h. Moreover, the sustained Erk1/2 activation induced apoptosis in cortical neurons. Significantly, pharmacological application of the MEK1 inhibitor PD98095 to roscovitine-treated cortical neurons prevented apoptosis. These results were also confirmed by knocking down Cdk5 activity in cortical neurons with Cdk5 small interference RNA. Apoptosis was correlated with a significant shift of phosphorylated tau and neurofilaments from axons to neuronal cell bodies. These results suggest that survival of cortical neurons is also dependent on tight Cdk5 modulation of the mitogen-activated protein kinase signaling pathway.
JEAN GENET'S QUEER ORIGINS: A READING OF
QUERELLE DE BREST
Authors: Kollias Hector
Published: November 2006

This article engages with debates in queer theory by attempting to look beyond the dominant trend of constructionism and interrogating the possibility of queer origins in the work of Jean Genet. In a reading of his novel
Querelle de Brest
, I seek to demonstrate that queer is located less in the self-assumption of subjectivity and more in the act of queer sex bestowing its agents with a series of metonymically substitutable role positions. Utilizing resources from psychoanalysis, I argue that Genet's novel is not a homophobic fantasy but rather an empowering narrative whose focus on betrayal can be aligned with the psychoanalytic notion of perversion as disavowal, allowing both Genet to be recognized as a salutary queer writer, and psychoanalysis to be wrested from the hostility with which it is received in queer-theoretical circles.
ROUND UP THE USUAL SUSPECTS: THE SEARCH FOR AN IDEOLOGY IN
LA PRINCESSE DE CLÈVES
Authors: Campbell John
Published: November 2006

This article considers various attempts to identify a clear structure of ideas, and their philosophical antecedents, in
La Princesse de Clèves
. These attempts arise naturally from the wide variations in interpretation that result from this novel's ambiguities. Many critics have made sense of the heroine's rejection of the man she loves by placing it in a religious framework, with roots in Augustinian/Jansenist thought, and thus in Neoplatonism. The influence of neo-Stoicism is also evident, for example in the mother's teaching and in her daughter's resistance to passion. However, these two currents of thought offer irreconcilable perspectives on free will. The situation is further complicated by the existence of an Epicurean dimension, in the value placed on prudence and on the retreat from emotional strife. Another element is Pyrrhonism, with its emphasis on the fragile basis of opinions and convictions. None of these ideologies offer an entirely persuasive explanation, yet they coexist uneasily. The difficulty of picking out totally convincing candidates from this identity parade necessarily leaves critics of this novel with questions as to the identity of our own hermeneutic endeavour.
Listeria monocytogenes translocates throughout the digestive tract in asymptomatic sheep
Authors: Zundel Etienne , Bernard Serge
Published: November 2006

Ruminants are fed forage which is often contaminated withListeria, and frequently shedListeria monocytogeneswith their faeces. The present study was designed to localize the sites of infection in the digestive tract concomitant withListeriafaecal excretion in a sheep model. TenListeria-free sheep were inoculatedper oswith a dose of 1010 c.f.u. of a pathogenicL. monocytogenesstrain.Listeriareceived by two of the ten animals were radiolabelled with111indium oxine. The dissemination of theListeriawas assessed byin vivoimaging, by culture of bacteria in the faeces, organs and digesta samples taken at slaughter on days 1, 2, 6, 10 and 14 post-inoculation, and by measuring gamma radioactivity of samples on day 6. It was shown thatListeriaspread through the entire volume of the forestomachs within 4 h, and through the whole gastrointestinal tract (GIT) within 24 h. Faecal shedding ofListerialasted 10 days. Rumen, duodenum, jejunum, ileum, caecum and colon walls and digesta, mesenteric lymph nodes, liver and spleen were temporarily infected. However,Listeriapersisted for at least 14 days in rumen digesta and retropharyngeal lymph nodes, and at a relatively high level (1×104 c.f.u. g−1) in palatine tonsils. These findings suggest thatL. monocytogenescan translocate from all parts of the GIT, with the rumen digesta, but not the gallbladder, serving as a reservoir. The results indicate that brief and low-level faecal excretion ofL. monocytogenesis concomitant with a transitory asymptomatic infection in sheep.
Mycobacterium kansasii olecranon bursitis
Authors: Barham G. S. , Hargreaves D. G.
Published: November 2006

A case is reported of a post-traumatic olecranon bursitis caused by Mycobacterium kansasii following an injury sustained in a public swimming pool. It responded to surgical debridement and combined rifampicin, isoniazid, pyrazinamide and ethambutol antimicrobial therapy. A literature search was performed and a treatment regimen for this uncommon condition is suggested.
Oral rabeprazole vs. intravenous pantoprazole: a comparison of the effect on intragastric pH in healthy subjects
Authors: ARMSTRONG D. , JAMES C. , CAMACHO F. , CHEN Y. , HORBAY G. L. A. , TEIXEIRA B. , HUSEIN‐BHABHA F. A.
Published: November 2006

Background

Intravenous pantoprazole is often administered inappropriately to hospitalized patients who can take oral medications.

Aim

To compare the antisecretory effects of oral rabeprazole and intravenous pantoprazole in healthy subjects.

Methods

In a double‐blind, double‐dummy, two‐way crossover study, 38 Helicobacter pylori‐negative volunteers were randomized to oral rabeprazole 20 mg or intravenous pantoprazole 40 mg daily for 3 days followed, after a 14‐day washout period by the comparator treatment. Intragastric pH was recorded continuously for 24 h at baseline and on days 1 and 3 of each treatment period.

Results

The mean (95% CI) percentage of the 24‐h recording with gastric pH >4 was higher with rabeprazole than with pantoprazole on day 1: 37.7% (30.6–44.8%) vs. 23.9% (20.0–27.8). The mean percentage times with pH >3 and >4 for all intervals assessed were greater and the median 24‐h intragastric pH values were higher with rabeprazole than with pantoprazole on days 1 and 3. The mean acidity index was lower with rabeprazole on days 1 and 3.

Conclusions

Oral rabeprazole 20 mg produced greater acid suppression than intravenous pantoprazole 40 mg. Therefore, it may be an appropriate and effective alternative in patients who can take oral medication.
Aliskiren, a novel orally effective renin inhibitor, exhibits similar pharmacokinetics and pharmacodynamics in Japanese and Caucasian subjects
Authors: Vaidyanathan Sujata , Jermany Joanne , Yeh ChingMing , Bizot Marie‐Noelle , Camisasca Riccardo
Published: November 2006

Aims

Aliskiren is the first in a new class of orally effective renin inhibitors for the treatment of hypertension. This study compared the pharmacokinetic and pharmacodynamic properties of aliskiren in Japanese and Caucasian subjects.

Methods

In this open‐label, single‐centre, parallel‐group, single‐ and multiple‐dose study, 19 Japanese and 19 Caucasian healthy young male subjects received a single 300‐mg oral dose of aliskiren on day 1 and then aliskiren 300 mg once daily on days 4–10. Blood samples were collected for the measurement of plasma aliskiren concentration, plasma renin concentration (PRC) and plasma renin activity (PRA).

Results

Pharmacokinetic parameters were comparable in Japanese and Caucasian subjects following administration of a single dose of aliskiren {ratio of geometric means: Cmax 1.12 [90% confidence interval (CI) 0.88, 1.43]; AUC0−72 h 1.19 [90% CI 1.02, 1.39]} and at steady state [mean ratio: Cmax 1.30 (90% CI 1.00, 1.70); AUC0–τ 1.16 (90% CI 0.95, 1.41)]. There was no notable difference in the plasma half‐life of aliskiren between Japanese and Caucasian groups (29.7 ± 10.2 h and 32.0 ± 6.6 h, respectively). At steady state, peak PRC level and AUC for the concentration–time plot were not significantly different between Japanese and Caucasian subjects (P = 0.64 and P = 0.80, respectively). A single oral dose of aliskiren significantly reduced PRA to a similar extent in Japanese and Caucasian subjects (by 87.5% and 85.7%, respectively, compared with baseline; P < 0.01). Aliskiren was well tolerated by both ethnic groups.

Conclusions

The oral renin inhibitor aliskiren demonstrated similar pharmacokinetic and pharmacodynamic properties in Japanese and Caucasian subjects.
Optimization of chapatti textural quality using British wheat cultivar flours
Authors: Salim‐ur‐rehman  , Paterson Alistair , Piggott John Raymond
Published: November 2006

Blending of British hard and soft wheats was explored using Fresco and Galahad, respectively, in an optimization of textural chapatti quality. For acceptability to consumers, chapatti dough should be extensible with limited recoil from the final sheet and produce breads with appropriate textural characteristics. A simple mixture design, employing rheological and viscoelastic studies, was used to establish an appropriate range of flour contents. Then, a shorter range in an optimization phase to define mixtures was applied. Texture softness of chapatti was evaluated through sensory and instrumental analyses at 3, 12 and 24 h of ambient storage. Dough of 33% Fresco and 67% Galahad composite flour had low shrinkage after sheeting and yielded chapattis sensory score high for texture softness, well correlated with instrumental data. The two‐phase experimental design produced a template for blending of flours for chapatti production.
Cephalaria syriaca addition to wheat flour dough and effect on rheological properties
Authors: Murat Karaoğlu Mehmet
Published: November 2006

Whole Cephalaria syriaca flour (WCSF), defatted C. syriaca flour (DCSF) and C. syriaca oil (CSO) were added to a medium strength wheat flour (WF). These were used to replace 0.5%, 1%, 1.5%, 2%, 2.5% and 3% of WF. The effects of WCSF, DCSF and CSO supplementation on rheological properties of dough were investigated. Overall, dough rheological characteristics improved with the addition of above‐mentioned C. syriaca products, and the effect was greater with WCSF and DCSF. Greater‐positive effects were observed in the extensograph characteristics at higher levels of supplementation than farinograph characteristics. The softness value and dough elasticity significantly (P < 0.05) increased as the C. syriaca products level increased; however, water absorption and dough stability decreased. As the level of WCSF and especially DCSF increased, maximum resistance to extension, area (energy) and ratio number increased and extensibility decreased. C. syriaca products increased dough resistance at least as good as an oxidising agent or more than those. The addition of DCSF at 1.5% level increased the maximum resistance to extension of dough and area (energy) from about 142 to 1000 BU and from 39 to 144 cm2, respectively.
Effect of baking procedure and storage on the pasting properties and staling of part‐baked and rebaked wheat bran bread
Authors: Karaoğlu Mehmet Murat
Published: November 2006

Wheat bran breads were part‐baked for 10, 15, 20 min at 230°C, with and without calcium propionate (0.2%), stored at refrigerator temperature (4°C) for 7, 14, 21 days and wrapped with two polyethylene bags. After storage, part‐baked and rebaked breads were subjected to volume, water activity and softness analysis, and pasting properties of bread crumb were determined using the Brabender amylograph. Addition of calcium propionate decreased pasting temperature and water activity of crumb of bran bread, while the bump area and viscosity values increased. The increase of initial baking time resulted in a decrease of pasting temperature, water activity and softness value, and in an increase of the bump area, viscosity and volume yield of the rebaked bran bread crumb. Pasting temperature, volume yield, water activity and softness value of crumb of the rebaked bran bread decreased with longer (intermediate storage) time. Pasting temperature, bump area and water activity significantly correlated with softness of bread crumb. The rebaking process of bran bread, which was part‐baked for 10 min and stored for 7 and 14 days at refrigerator temperature, resulted in a softer crumb than in the control group.
Textural and sensory quality enhancement of sorghum tuwo
Authors: Bolade Mathew K. , Buraimoh Moriamo S.
Published: November 2006

The study was focused on the improvement of textural and sensory qualities of sorghum tuwo by the use of hydrothermal treatment in modifying the physicochemical properties of sorghum grains. Flour was obtained from sorghum grains subjected to hydrothermal treatments at temperatures ranging between 65 and 95 °C for varying time intervals of 30, 45 and 60 min respectively. Flours obtained through the hydrothermal processes were found to be greatly affected in both pasting and functional properties as well as in flour yield when compared with flour obtained through the traditional processing methods. The sensory evaluation on sorghum tuwo prepared showed that a particular tuwo sample, D1 (from flour whose grains were hydrothermally treated at 95 ± 1 °C for 30 min), was rated highest in comparison with that from traditionally produced flour in terms of taste, texture (mouldability) and overall acceptability.
The effect of emergency department delay on outcome in critically ill medical patients: evaluation using hospital mortality and quality of life at 6 months
Authors: SAUKKONEN K. A. , VARPULA M. , RÄSÄNEN P. , ROINE R. P. , VOIPIO‐PULKKI L.‐M. , PETTILÄ V.
Published: November 2006

Objective.  To assess the impact of delay in emergency department (ED) on outcome of critically ill patients admitted to the medical intensive care unit (MICU). Outcome was defined as hospital mortality and as health‐related quality of life (HRQoL) at 6 months after intensive care assessed by the 15D measure. The 15D is a generic, 15‐dimensional, standardized measure of HRQoL. We hypothesized that prolonged stay in the ED is related to worse outcome.

Design and setting.  A prospective follow‐up cohort study in university hospital.

Subjects.  All consecutive 1675 patients admitted to the MICU between July 2002 and June 2004.

Results.  The 15D questionnaire was mailed to all patients alive at 6 months after admission. Of all MICU patients, 64% were admitted from ED. The mean length of stay in the ED was 6.2 h (95%CI 5.9–6.5 h). The hospital mortality rate was 24.4% (20.0% in the ED vs. 33.0% in the non‐ED cohort, P < 0.001) and it was associated with higher age and degree of physiological derangement at admission. Neither the length of ED stay was associated with hospital mortality (P = 0.82) nor with HRQoL at 6 months after MICU admission (P = 0.34). Altogether, HRQoL at 6 months was significantly lower compared with the age‐ and sex‐matched general population (P < 0.001).

Conclusions.  In a university hospital, the length of ED stay was not associated with the outcome of critically ill medical patients. However, we feel that the effect of ED treatment and delay on outcome and outcome prediction in the critically ill patients deserves further evaluation.
Insertion polymorphism of transposable elements and population structure of Anopheles gambiae M and S molecular forms in Cameroon
Authors: BOULESTEIX M. , SIMARD F. , ANTONIO‐NKONDJIO C. , AWONO‐AMBENE H. P. , FONTENILLE D. , BIÉMONT C.
Published: November 2006

The insertion polymorphism of five transposable element (TE) families was studied by Southern blots in several populations of the M and S molecular forms of the mosquito Anopheles gambiae sensu stricto from southern Cameroon. We showed that the mean TE insertion site number and the within‐population insertion site polymorphism globally differed between the M and S molecular forms. The comparison of the TE insertion profiles of the populations revealed a significant differentiation between these two molecular forms (0.163 < ΦST < 0.371). We cloned several insertions of a non‐LTR retrotransposon (Aara8) that were fixed in one form and absent in the other one. The only insertion that could be clearly located on a chromosome arm mapped to cytological division 6 of chromosome X, confirming the importance of this region in the ongoing speciation between the M and S molecular forms.
A Review on Peste des Petits Ruminants (PPR) with Special Reference to PPR in Iran
Authors: Bazarghani T. T. , Charkhkar S. , Doroudi J. , Bani Hassan E.
Published: November 2006

In 1995, a peste des petits ruminants (PPR) outbreak was diagnosed in Ilam province in Iran near the border with Iraq both serologically and virologically. As then, despite all control measures, PPR has been identified in the whole country and has led to costs of at least US$1.5 million to the Iranian owners of sheep and goats.
Oestrous Behaviour and Timing of Ovulation in Relation to Onset of Oestrus and LH Peak in Mithun (Bos frontalis) Cows
Authors: Mondal M , Rajkhowa C , Prakash BS
Published: November 2006

Contents

The objectives of the study were to evaluate the oestrus behaviour and to determine the timing of ovulation in relation to onset of oestrus and the pre‐ovulatory LH surge in mithun (Bos frontalis). For this purpose, the blood samples collected at 15‐min intervals for 9 h period following onset of oestrus and thereafter, at an interval of 2 h till 4 h post‐ovulation for three consecutive cycles from 12 mithun cows were assayed for plasma LH and progesterone. Ovulation was confirmed by palpation of ovaries per rectum at hourly intervals. Various signs of behavioural oestrus were also recorded. The common signs of oestrus and their frequency of occurrence in mithuns were following and mounting by male mithuns (100%), standing to be mounted (100%), frequent urination (62.33%), raising of tail (65.23%), swelling of vulva (54.26%) and congestion of vulvar mucous membrane (69.87%). The pre‐ovulatory LH surges consisted of several pulses (2.92 ± 0.26 pulses/animal; range, 1–4). The mean (±SEM) peak level of LH for individual mithun varied from 6.99 ± 0.44 to 12.69 ± 2.10 ng/ml and the mean pooled LH peak concentration was 9.10 ± 0.60 ng/ml. The highest peak (highest amplitude of LH during LH surge) was 10.83 ± 0.76 ng/ml (range, 8.07–16.49 ng/ml). The duration of LH surge was 6.98 ± 0.22 h (6–8 h). Onset of LH surge was at 1.23 ± 0.17 h post‐oestrus onset (range, 0.25–2.25 h). Mean plasma progesterone stayed low (<0.24 ng/ml) during the entire duration of sampling. Ovulation occurred at 26.92 ± 0.31 (range, 26–29 h) after the onset of oestrus and 18.63 ± 0.35 h (range, 17–20.75 h) after the end of LH surge. The occurrence of the highest LH peaks within a narrow time frame of 2‐ to 5‐h post‐oestrus onset in mithuns could have contributed to the animals ovulating within a narrow time interval. These results are very promising from a practical standpoint of potential success when AI program in this species is implemented in a big way. Furthermore, the results of the occurrence of LH pulses during pre‐ovulatory LH surges, which are required for ovulation in this species of animals, is unique and species specific.
Effect of cognitive training focusing on organizational strategies in patients with obsessive‐compulsive disorder
Authors: PARK HEE SOO , SHIN YONG‐WOOK , HA TAE HYON , SHIN MIN SUP , KIM YOUNG YOUN , LEE YOUNG HO , KWON JUN SOO
Published: November 2006

Abstract  The purpose of the present paper was to develop a cognitive training program for patients with obsessive‐compulsive disorder (OCD) and evaluate its effectiveness. Nine 60‐min sessions focusing on the improvement of organizational strategies were given to 15 patients with OCD over a period of 5 weeks. The control group consisted of 15 age‐ and sex‐matched patients also with OCD. The Rey–Osterrieth Complex Figure Test and Korean–California Verbal Learning Test were administered before and after cognitive training. Clinical symptoms were assessed with the Yale–Brown Obsessive‐Compulsive Scale. The memory function in the treatment group improved and their clinical symptoms were alleviated after training, compared to those of the control group. Cognitive training of OCD patients not only improved their memory function, but also alleviated their clinical symptoms. Therefore, cognitive training, focusing on the improvement of organizational strategies, could be an effective treatment modality for patients with OCD.
Intratesticular borderline serous tumor
Authors: ABDULLAH LAYLA SALEH , GUPTA RICHTA , ARNST A
Published: November 2006

Abstract  Neoplasms resembling ovarian serous tumors rarely arise in the male genital organs. Müllerian histogenesis of this tumor has been suggested. We report a case of an intratesticular borderline serous tumor accidentally discovered during the course of a preoperative workup in a 72‐year‐old man admitted for left upper lobectomy for squamous cell carcinoma of the lung.
Water pipeline failure due to water hammer effects
Authors: SCHMITT C. , PLUVINAGE G. , HADJ‐TAIEB E. , AKID R.
Published: November 2006

A numerical model has been established in order to simulate the propagation of pressure waves in water networks. The present model formulation is based on a system of partial hyperbolic differential equations. This system has been solved via the characteristics method. The current model provides the necessary data and the necessary damping of water hammer waves, taking into account the structure of the pipe network and the pressure loss. The numerical algorithm estimates the maximum pressure values resulting from the water hammer when closing valves in the network and consequently, the maximum stresses in the pipes have been calculated. In the case of simultaneous closing of several valves, the over pressure can exceed the admissible pressure. In this case, the severity of a defect such as a corrosion crater (pit) has been estimated by computing a safety factor for the stress distribution at the defect tip. This allows the applied notch stress intensity factor to be obtained. To investigate the defect geometry effects, semi‐spherical and semi‐elliptical defects are deemed to exist in up to one‐half of the thickness of the pipe wall. The outcomes have been introduced into the structural integrity assessment procedure (SINTAP) failure diagram assessment (FAD) in order to obtain the safety factor value. Conventionally, it is considered that a failure hazard exists if this safety factor is less than two.
STABILITY OF THE COURNOT SOLUTION AND FREE ENTRY: A NOTE*
Authors: IKEDA TAKESHI
Published: November 2006

Taking a traditional approach, I show that by using the discrete adjustment system, the Cournot solution in a free entry oligopoly with increasing returns to scale is stable only when the number of firms is very small. We must pay attention to stability when using the free entry Cournot oligopoly model.