bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Z-scores to Rank Applicants to Professional Degree Programs
Authors: Raghavan Malathi , Martin Bruce D. , Aoki Fred , MacKalski Barbara , Christensen Heather
Published: November 2012

Criteria for assessing suitability of applicants for professional degree programs such as veterinary medicine are usually treated as distinct components of a composite scoring procedure that determines applicant ranking. Some components are valued more than others, which is reflected in the relative weights assigned to each component. However, the patterns of dispersal of individual components have the potential to alter the assigned relative weights. Components with larger variances can have greater influences on composite scores than intended. Such unintended altered weighting can be avoided through standardization. Yet non-standardized approaches continue to be used for admissions ranking in several programs. In this study, we documented the potential for differential selection of applicants when non-standardized scoring approaches are applied to admissions assessment components. At our medical school, applicants' component scores with differing variances are standardized by determining Z-scores with a mean of 0 and standard deviation of 1 before mathematically combining to calculate composite scores and admissions ranking. We retrospectively and hypothetically ranked one applicant cohort using non-standardized methods and identified differences in ranking between the standardized and non-standardized approaches. Most differences were observed for applicants in the second, third, and fourth quintiles of the admissions rank list, that is, those for whom admissions cut-off decisions make a marked difference. Observations were supported by lower Spearman's rank correlation coefficients in these quintiles. Although standardization of component scores is not a novel topic, we document the implications of using non-standardized scoring approaches for applicant ranking and underscore the importance of standardization of component scores.
Modeling the effect of austenite deformation on the bainite structure parameters in low carbon microalloyed steels
Authors: Zolotorevsky Nikolay , Nesterova Elena , Titovets Yuri , Khlusova Elena
Published: November 2012

A modeling approach to calculate the kinetics of non-isothermal bainite formation in low carbon microalloyed steels is presented. The model development is based on experimental data obtained by means of deformation dilatometry and electron back scattering diffraction. It is suggested that the misorientations inherited from the plastically deformed austenite make a significant contribution to the misorientation distribution in the final microstructure. Taking the inheritance phenomenon into consideration, the model allows prediction of the transformation kinetics and the effective grain size of bainitic microstructure as a function of the austenite deformation level and the cooling rate.
Fabrication of micro/nano structured aluminum–nickel energetic composites by means of ultrasonic powder consolidation
Authors: Erdeniz Dinc , Ando Teiichi
Published: November 2012

Al–Ni energetic composites, applicable to localized heating, were fabricated from atomized powders and hammer-milled flakes by means of ultrasonic powder consolidation, a novel low-temperature rapid powder consolidation technique. Full-density consolidation was achieved in 1 s of consolidation time at temperatures as low as 573 K without causing appreciable reactions between Al and Ni. The consolidated composite structure consists of Ni powder particles or flakes uniformly distributed in a metallurgically consolidated Al matrix. Consolidated materials were evaluated using spark and continuous-heating ignition tests. Ultrasonic powder consolidation is potentially applicable to the fabrication of a wide range of metastable materials that cannot be processed at elevated temperatures.
Characterization of silicon-silicon carbide ceramic derived from carbon-carbon silicon carbide composites
Authors: Srivastava Vijay K. , Krenkel Walter
Published: November 2012

The main objective of the present work is to process porous silicon–silicon carbide (Si–SiC) ceramic by the oxidation of carbon–carbon silicon carbide (C/C–SiC) composites. Phase studies are performed on the oxidized porous composite to examine the changes due to the high temperature oxidation. Further, various characterization techniques are performed on Si–SiC ceramics in order to study the material's microstructure. The effects of various parameters such as fiber alignment (twill weave and short/chopped fiber) and phenolic resin type (resol and novolak) are characterized.
Solubility study of the copper-lead system
Authors: Vaajamo Iina , Johto Hannu , Taskinen Pekka
Published: November 2012

In this study isothermal equilibration experiments were done at 866–1 166 K for the copper–lead (Cu-Pb) binary system. The experiments, conducted in a quartz ampoule, enabled the solubility limits at each end of the phase diagram to be obtained. In addition to the experiments, a literature survey and compilation of the experimental data of the solid solubilities was done. Critically evaluated and selected literature data and our own experimental values were used to optimise the fcc phase interaction parameters. According to the experiments the lead solubility in solid copper at the copper-rich end is smaller than previously reported. The liquidus curve at the lead-rich end was validated with our own experimental results, which agree well with previous experimental data. The thermodynamic assessment of the Cu-Pb system, in the area of fcc_A1 solid solutions, has been improved.
Preparation and magnetic characterization of Fe/metal oxide nanocomposite particles by means of hydrogen reduction assisted ultrasonic spray pyrolysis (USP-HR)
Authors: Ebin Burçak , Toparlı Çiğdem , Gürmen Sebahattin
Published: November 2012

Fe/metal oxide nanocomposite particles were produced by means of hydrogen reduction assisted ultrasonic spray pyrolysis. Fe/Fe0.761Mg0.239O and Fe/MgO nanocomposite particles were obtained at 600 and 800 °C, respectively. The thermodynamics of the formation reactions were investigated. Increasing the reaction temperature allowed efficient reduction of the precursor to metallic iron that induces the formation of pure MgO phase. The crystallite sizes of the Fe in the composite structures slightly increased, and also the crystallite sizes of the oxides decreased with elevating temperature. The nanocomposite particles exhibited spherical morphology and their particle sizes were slightly different. All of the samples showed ferromagnetic characteristics and the results indicate that the amount of metal and metal oxide phases most affected the saturation magnetizations of the composite particles which were lower than pure iron.
Synthesis of Ir1-xRex (0.15 ≤ x ≤ 0.40) solid solutions under high-pressure and high-temperature
Authors: Gromilov Sergey A. , Dyachkova Tatiyana V. , Bykova Elena A. , Tarakina Nadezda V. , Zaynulin Yurii G. , Yusenko Kirill V.
Published: November 2012

Ir1–xRex (0.15 ≤ x ≤ 0.40) phases prepared under high-pressure, high-temperature conditions from nanopowders of iridium and rhenium were characterized using powder X-ray diffraction and scanning electron microscopy. Structural characteristics of the phases obtained were identical with the corresponding parameters for the solid solutions prepared by means of melting and thermal decomposition of the precursors. The data obtained make it possible to improve solid-state solubility limits in the binary Ir–Re phase diagram. As revealed, the maximum solid solubility of Ir in Re is 68 at.%, and that of Re in Ir is 20 at.%.
The effect of nitrogen on the coarsening rate of precipitate phases in iron-based alloys with chromium and vanadium: experimental and theoretical investigations
Authors: Lindwall Greta , Frisk Karin
Published: November 2012

A comparison of the coarsening of nitrogen-rich vanadium precipitates and the coarsening of carbon-rich vanadium precipitates is presented. The precipitate phases are studied experimentally, via fabrication of model alloys, and theoretically, via simulations utilizing the DICTRA software. The experimental investigations indicate that the nitrogen-rich precipitates exhibit a slower coarsening behaviour than the carbon-rich precipitates. Analysis using thermodynamic and kinetic modelling shows that this can be explained by the higher thermodynamic stability of the nitrogen-rich precipitate compared to the carbon-rich precipitate. The calculated coarsening rates are compared with the measured rates, and found to be in satisfactory agreement using reasonable values for the interfacial energies. The investigations are motivated by the fine precipitate size distribution of nitrides and carbonitrides characteristic for high nitrogen alloyed tool steels produced by means of powder metallurgy.
Phase diagram investigation of the Sn-In
x
Ag
y
Cu
z
(x:y:z = 7:2:1) section in the Ag-In-Sn-Cu system
Authors: Milosavljević Aleksandra , Živković Dragana , Manasijević Dragan , Du Yong , Talijan Nadežda , Bu Mengjie , Kostov Ana
Published: November 2012

The results of phase diagram investigation and characterization of the Ag-In-Sn-Cu system are presented in this paper. Samples at the In : Ag : Cu = 7 : 2 : 1 vertical section were measured with differential scanning calorimetry, and the obtained transition temperatures were compared with calculated values. From Calphad-type calculation, the phase diagram for Sn-In
x
Ag
y
Cu
z
(molar ratio x:y:z = 7:2:1) section is constructed. In order to obtain the microstructure of investigated alloys, scanning electron microscopy with energy dispersive X-ray spectroscopy was used.
Characterization of electrospun fibrous scaffold produced from Indian eri silk fibroin
Authors: Andiyappan Muthumanickam , Sundaramoorthy Subramanian , Vidyasekar Prasanna , Srinivasan Natarajan Tirupattur , Verma Rama Shanker
Published: November 2012

A scaffold, synthesized from bio-degradable polymers and Bombyx
mori silk fibroin in the form of films and fibrous assemblies, has been used as the bio-material for in-vivo applications. In the present work, the scaffold was prepared from the fibroin of Indian eri silk via the electrospinning method. The diameter of the fibre produced was in the range of 300 to 900 nm. The scaffold was subjected to ethanol treatment to improve its dimensional stability, as there was the problem of curling and shrinking when it was treated with solutions used for the cell culture. The scaffold was characterized for surface, thermal and tensile properties. The dimensional stability of the scaffold improved and the porosity reduced, due to the treatment of the scaffold with ethanol. The average failure stress of the raw and ethanol treated scaffold was 2.34 MPa and 4.91 MPa respectively and the mean strain was 13.63 % and 7.91 % respectively. Bone marrow stromal cells were isolated from the bone marrow of Swiss albino mice, and cultured on the ethanol treated electrospun fibrous scaffold. Scanning electron microscopy of the culture was carried out to evaluate the attachment and growth of cells on the scaffold at different incubation periods. Mouse bone marrow stromal cells adhered and grew on the electrospun fibrous scaffold prepared from eri silk fibroin, and the cell density increased with increasing incubation periods.
Thermophysical properties of solid phase palladium over a wide temperature range
Authors: Milošević Nenad , Babić Marijana
Published: November 2012

This paper presents experimental results of a range of thermophysical properties of pure polycrystalline palladium samples over a wide temperature range. Specific heat capacity was measured from 250 to 1 770 K, specific electrical resistivity from 250 to 1 800 K, hemispherical total emissivity from 1 100 to 1 800 K, normal spectral emissivity from 1 340 to 1 720 K, and thermal diffusivity in the range from 200 to 1 540 K. From the measured data, the thermal conductivity and Lorentz function were computed in the range from 250 to 1 540 K. Specific heat capacity, electrical resistivity, and both emissivities were measured by means of subsecond pulse calorimetry, while the thermal diffusivity was obtained using the laser flash technique. The first method used specimens in the form of a thin rod, of about 2 mm in diameter and 200 mm in length, and the second disk specimens of about 3 mm in thickness and 10 mm in diameter. For necessary corrections, literature data on thermal linear expansion have been used. All the results are compared with available literature data and discussed.
Analysis of size effect and anisotropy of 6H – SiC thermal conductivity
Authors: Wang Z. H. , Zhang L. Y. , Meng X.
Published: November 2012

Silicon carbide has been used in refractories, ceramics, and numerous high-performance applications with very good mechanical properties and high thermal conductivity. Silicon carbide composites have excellent potential as a low-activation structural material for fusion and industrial applications. Thermal properties of silicon carbide ceramics are important for the design and safe operation in these situations. To obtain the thermal properties of silicon carbide ceramics, based on the nonequilibrium molecular dynamics simulation method, the size effect on thermal conductivity in different directions is described. 6H – SiC thermal conductivities in the normal and tangential directions are predicted in a nanoscale cuboid system. It is found that there is an obvious size effect and anisotropy of thermal conductivity in different directions because of the impact of the boundary scattering. The normal and tangential thermal conductivity equations have been obtained as good power function expressions. The results show that boundary scattering is strong in phonon transport in different directions within thin film silicon carbide.
Influence of Twin-Screw Processing Conditions on Structure and Properties of Polypropylene – Organoclay Nanocomposites
Authors: Domenech T. , Peuvrel-Disdier E. , Vergnes B.
Published: November 2012

This study looks at the influence of extrusion parameters such as screw speed, feed rate and barrel temperature on the nanocomposite structure (size of agglomerates, level of intercalation and exfoliation) and its consequences on final mechanical properties. Nanocomposites of polypropylene, maleated polypropylene and organomodified montmorillonite, with respective mass fractions of 85/10/5, were prepared in a co-rotating twin-screw extruder using a masterbatch dilution method. The nanocomposites structure was quantified by scanning and transmission electron microscopy, X-ray diffraction and dynamic rheometry. Relationships between the microstructure at different levels (size and number of agglomerates, interlayer distance, melt yield stress to quantify the exfoliation level) and the processing conditions were established, revealing that specific mechanical energy received during extrusion was the key parameter controlling this microstructure. Mechanical properties in uniaxial tension (apparent Young's modulus) were measured and related to the microstructural parameters resulting from extrusion conditions.
Design and Validation of a Cable Extrusion Tip with Spiral Channels
Authors: Haller D. , Gonnet J.-M. , Lankes C.
Published: November 2012

Traditional cable extrusion dies employ a side-fed flow distribution system. In this case, the flow is split into two streams, resulting in the formation of a weld line. The weld line runs as a radial line through the cross section of the cable coating and has the least favorable orientation when the cable coating is exposed to circumferential stresses. Therefore, a new cable extrusion tip based on the principle of spiral mandrel dies was developed to change the orientation of the weld line from radial, that takes place when side-fed mandrel dies are used, to circumferential, when melt distribution resulting from the layering of the leakage flow in spiral mandrel dies occurs. The circumferential orientation of the weld line reduces the exposure of the weld line to circumferential stresses and thus improves the mechanical properties of the cable coating. This paper first outlines the design strategy for the new cable extrusion tip and further presents experimental results. The design strategy is based on two-dimensional flow networks. The network model is applied to calculate the flow channel geometry for a wanted distribution of the flow. Further, it should generate a better understanding of the correlation between the flow, pressure drop, and the flow channel geometry to facilitate the design of the tip. Three dimensional FEM simulations were used in this work to validate the flow network model in terms of pressure drop and velocity profile at the exit of the tip. The results of the calculations with the network model show good accordance with three dimensional FEM-simulations. For the experimental part a tensile test was conducted to compare the tensile strength in circumferential direction of a cable extruded with the new tip with a cable extruded with a conventional cable extrusion tip. The measurements showed an increase of the tensile strength in circumferential direction of 10% to 15% for the cable extruded with the new tip compared to the tensile strength at the location of the weld line in the cable extruded with the conventional tip.
Mechanical Properties and Fracture Morphology of Blends of PC with PMMA
Authors: Lee S.-K. , Cho S.-S. , Kang L.-S. , Lee C. G. , Hong H. S.
Published: November 2012

The poly methyl methacrylate (PMMA) and polycarbonate (PC) residues were collected from waste LCD panels for use as raw materials to prepare PC/PMMA polymer blends (1/99, 3/97, 5/95, 10/90), which were extruded in a twin screw extruder. The extrudates were subsequently pelletized and then dried in an oven before injection molding into tensile bars of ASTM D638-91, type I. The tensile bars were placed in an Instron-type tensile tester and the load-elongation curves of tested 5/95 specimens demonstrated distinctively varied yielding before final brittle fracture but 10/90 showed some sign of ductile behavior, peak in the load-elongation curve attributable to formation of a neck. The tensile strength increased from 569.6 to 633.3 kgf/cm2 with PC concentration in the range of 1 to 5 wt% while it decreased at 10 wt% PC. On the contrary, transverse rupture strength increased with added amount of PC. Addition of PC could have toughened recycled PMMA matrix under impact test conditions. Finally, the fractured surfaces were examined by scanning electron microscopy and numerous fine particles dispersed in the matrix of 10/90 are regarded as PC phase, in reasonable agreement with literature results. On the other hand, fracture surface of 5/95 showed nearly homogeneous matrix phase of PC/PMMA.
Effect of Prepolymerization Time on Morphology and Properties of Epoxy-modified Bismaleimide Foams
Authors: Liu X. , Lu H. , Xing L.
Published: November 2012

Epoxy-modified bismaleimide (BMI) foams were prepared through prepolymerization and foaming. Density-adjustable BMI foams with closed-cell structures were produced. The influence of prepolymerization time on bubble growth and morphology, as well as the compressive and heat resistant properties of the foams, were thoroughly investigated. BMI prepolymerization was an effective method for controlling the bubble growth rate, the bubble size and its distribution, and the foam density. As the prepolymerization time increased, the matrix viscosity, the number of cells per unit volume and the foam density increased, whereas, the bubble growth rate and cell size decreased, and the cell size distribution became narrower. The compressive strength and modulus increased with increasing prepolymerization time. The dimensional stability temperatures of the BMI foams were all above 200°C, as determined by their base materials, and were unaffected by prepolymerization time.
Effects of a Multifunctional Polymeric Chain Extender on the Properties of Polylactide and Polylactide/Clay Nanocomposites
Authors: Meng Q.-K. , Heuzey M.-C. , Carreau P. J.
Published: November 2012

A multifunctional polymeric chain extender (Joncryl) was used in the melt processing of a neat polylactide and polylactide/clay nanocomposites. The effects of Joncryl on morphology, rheology, thermal and mechanical properties, barrier properties and biodegradability were investigated. Three Joncryl loadings (0.1, 0.3 and 0.5 wt%) were used in this study, and the 0.5 wt% loading induced a long-chain branched structure in the PLA matrix, as indicated by the melt rheology results. It is believed that the property variations are all related to the long-chain branched structure as well as on the molecular weight recovery. The use of Joncryl did not change the intercalated and partially exfoliated clay structures in the PLA/clay nanocomposites, as observed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The tensile modulus and maximum strength slightly increased with Joncryl loading. The oxygen barrier properties were also improved by adding Joncryl. However, the addition of Joncryl prevented the formation of large spherulitic crystals and decreased the creep resistance at low stress level. Joncryl could not only control the thermal degradation of PLA during processing, but also affected its biodegradation in compost: higher Joncryl loading led to slower biodegradation and less molecular weight reduction with time.
Grain-size evolution of polar firn: a new empirical grain growth parameterization based on X-ray microcomputer tomography measurements
Authors: Linow Stefanie , Hörhold Maria W. , Freitag Johannes
Published: November 2012

Firn microstructure properties from six different sites in Greenland and Antarctica are investigated by means of X-ray microcomputer tomography. The optical effective radius is calculated from the specific surface area (SSA) and used as a measure of grain size. It is shown that the recently introduced spherical approximation of firn grains using the effective radius Reff is representative of grain size in the microwave frequency region. The measured profiles show the well-known increase of grain size with depth at all sites, where the increase is largest at near-surface depths. A large variability in grain size on the decimeter-to-centimeter scale as a result of different grain properties of single layers is superimposed on the overall trend at each site. A simple empirical parameterization of grain-size evolution is developed which allows the rapid grain growth in the uppermost layers of the firn to be predicted. The growth is driven by strong seasonal and diurnal temperature gradients. The model can be used to simulate grain-size profiles required by models of firn/microwave interaction (e.g. for retrieval of accumulation rates from satellite microwave sensors) in a more realistic fashion.
Ice-shelf basal channels in a coupled ice/ocean model
Authors: Gladish Carl V. , Holland David M. , Holland Paul R. , Price Stephen F.
Published: November 2012

A numerical model for an interacting ice shelf and ocean is presented in which the ice- shelf base exhibits a channelized morphology similar to that observed beneath Petermann Gletscher’s (Greenland) floating ice shelf. Channels are initiated by irregularities in the ice along the grounding line and then enlarged by ocean melting. To a first approximation, spatially variable basal melting seaward of the grounding line acts as a steel-rule die or a stencil, imparting a channelized form to the ice base as it passes by. Ocean circulation in the region of high melt is inertial in the along-channel direction and geostrophically balanced in the transverse direction. Melt rates depend on the wavelength of imposed variations in ice thickness where it enters the shelf, with shorter wavelengths reducing overall melting. Petermann Gletscher’s narrow basal channels may therefore act to preserve the ice shelf against excessive melting. Overall melting in the model increases for a warming of the subsurface water. The same sensitivity holds for very slight cooling, but for cooling of a few tenths of a degree a reorganization of the spatial pattern of melting leads, surprisingly, to catastrophic thinning of the ice shelf 12 km from the grounding line. Subglacial discharge of fresh water along the grounding line increases overall melting. The eventual steady state depends on when discharge is initiated in the transient history of the ice, showing that multiple steady states of the coupled system exist in general.
Outlet glacier response to forcing over hourly to interannual timescales, Jakobshavn Isbræ, Greenland
Authors: Podrasky David , Truffer Martin , Fahnestock Mark , Amundson Jason M. , Cassotto Ryan , Joughin Ian
Published: November 2012

The loss of the floating ice tongue on Jakobshavn Isbrӕ, Greenland, in the early 2000s has been concurrent with a pattern of thinning, retreat and acceleration leading to enhanced contribution to global sea level. These changes on decadal timescales have been well documented. Here we identify how the glacier responds to forcings on shorter timescales, such as from variations in surface melt, the drainage of supraglacial lakes and seasonal fluctuations in terminus position. Ice motion and surface melt were monitored intermittently from 2006 to 2008. Dual-frequency GPS were deployed 20–50 km upstream of the terminus along the glacier center line. Gaps in surface melt measurements were filled using a temperature-index model of ablation driven by surface air temperatures recorded during the same time period. Our results corroborate the premise that the primary factors controlling speeds on Jakobshavn Isbrӕ are terminus position and geometry. We also observe that surface speeds demonstrate a complex relationship with meltwater input: on diurnal timescales, velocities closely match changes in water input; however, on seasonal timescales a longer, more intense melt season was observed to effectively reduce the overall ice flow of the glacier for the whole year
’He wasn’t in that chair’: what loneliness means to widowed older people
Authors: Bennet Kate Mary , Victor Christina
Published: November 2012

We have little robust empirical evidence that articulates what being lonely means to older people and even less knowledge about what loneliness means to older widows and widowers; this article addresses that deficit. We undertook a re-analysis of 125 interviews with older people (aged 55-98) that explored their experiences of widowhood. In this article, we focus on those interviews in which participants described themselves as experiencing loneliness by the spontaneous use of terms such as ’’lonely’’, ’’loneliness’’ or ’’lonesome’’. Almost half of the participants (42%) described themselves in that way without any prompting from the interviewer. In terms of understanding and describing the meaning of loneliness, 50% explained loneliness in terms of absence of either their spouse, a physical presence in the house or people. One-third (34%) discussed loneliness in relation to time and place: night, weekends and home, and 4% described the emotional impact of loneliness. Fifteen per cent just said they were lonely without elaboration, assuming a common understanding of what loneliness means. Our findings suggest that widowed people’s understanding and experience of loneliness resonates with the concept of ’’emotional’’ loneliness, resulting from the loss of significant social and emotional attachment. This has important implications for the types of interventions that may be appropriate for remediating loneliness in this group.
“Otherwise it would be nothing but cruises”: exploring the subjective benefits of working beyond 65
Authors: Reynolds Frances , Farrow Alexandra , Blank Alison
Published: November 2012

The age at which statutory and private pensions are being paid is increasing in many countries and hence more people will need to work into their late 60s and beyond. At present, relatively little is known about the meanings of work for people who actively choose to work into their later life. This qualitative study examined the subjective benefits of continuing in a paid job or self-employment beyond the age of 65 in the United Kingdom. Thirty-one participants were interviewed, aged 65-91 years (median age 71), with 11 females and 20 males. Fourteen were working full-time and seventeen part-time. Interview transcripts were subject to thematic analysis. Although financial reward was acknowledged (more so by the female participants and the males who had young second families), there was more elaboration of the role of work in maintaining health and enabling continuing personal development. Work was framed as increasing personal control over later life, lifestyle choices and active participation in wider society, an antithesis to ’’cruising’’.
Dale Dannefer & Chris Phillipson (eds.) (2010). The SAGE Handbook of Social Gerontology. Los Angeles, London, New Delhi, Singapore, Washington DC: SAGE Publications, 712 pp. ISBN 978 1 4129 3464 0 (hardcover)
Authors: Öberg Peter
Published: November 2012

Not Available.
Animal Sentience: Where Are We and Where Are We Heading?
Authors: Proctor Helen
Published: November 2012

The science of animal sentience underpins the entire animal welfare movement. Demonstrating objectively what animals are capable of is key to achieving a positive change in attitudes and actions towards animals, and a real, sustainable difference for animal welfare. This paper briefly summarises understanding and acceptance of animal sentience through the ages. Although not an exhaustive history, it highlights some of the leading figures whose opinions and work have most affected perspectives of animal sentience. There follows a review of the current state of animal sentience, what is known, and what the main limitations have been for the development of the study of sentience. The paper concludes with some thoughts for the future of the science, and where it should be going in order to most benefit animal welfare.
Evaluation of Acrylamide in Food from China by a LC/MS/MS Method
Authors: Chen Yong-Hong , Xia En-Qin , Xu Xiang-Rong , Ling Wen-Hua , Li Sha , Wu Shan , Deng Gui-Fang , Zou Zhi-Fei , Zhou Jing , Li Hua-Bin
Published: November 2012

Acrylamide is potential carcinogenic compound that possesses neurotoxicity activity. In this study, the levels of acrylamide in 123 selected food samples from China was evaluated using a LC/MS/MS method. One hundred and fifteen (115) out of 123 samples showed positive levels of acrylamide in the range of 0.41 to 4,126.26 µg/kg. Generally, the highest acrylamide levels were found in fried products, such as potato, prawn strips and rice crust, with average values of 604.27, 341.40, and 201.51 µg/kg, respectively. Heated protein-rich food also showed some acrylamide content (ranging from 2.31 to 78.57 µg/kg). The results revealed that a potential acrylamide public health risk occurred in processed snacks, as well as the food consumed daily. This study supplied new information on acrylamide content of a variety of heat-treated foods from China.
Evaluation of Benzo[a]pyrene in Food from China by High-Performance Liquid Chromatography-Fluorescence Detection
Authors: Chen Yong-Hong , Xia En-Qin , Xu Xiang-Rong , Li Sha , Ling Wen-Hua , Wu Shan , Deng Gui-Fang , Zou Zhi-Fei , Zhou Jing , Li Hua-Bin
Published: November 2012

The occurrence and levels of benzo[a]pyrene in various heat-treated foods from China were evaluated by high-performance liquid chromatography-fluorescence detection. In a total of 119 samples, 105 were found to contain benzo[a]pyrene at levels of 0.03 to 19.75 µg/kg. The benzo[a]pyrene contents in 12 animal source foods were higher than the Chinese maximum permissible level in food (5 µg/kg) and the highest level was 19.75 µg/kg, nearly four times the maximum permissible level. The results revealed a widespread carinogenic public health risk from benzo[a]pyrene in heat-treated foods. The highest benzo[a]pyrene levels were found in animal source samples such as charcoal-grilled and smoked meats, especially pork, beef and sausage, while trace levels of benzo[a]pyrene were present in grain food. Charcoal-grilled vegetables were found to also contain certain levels of benzo[a]pyrene. This study provided new information on benzo[a]pyrene content of a variety of heat-treated foods from China.
Probing Nucleic Acid Interactions and Pre-mRNA Splicing by Förster Resonance Energy Transfer (FRET) Microscopy
Authors: Šimková Eva , Staněk David
Published: November 2012

Förster resonance energy transfer (FRET) microscopy is a powerful technique routinely used to monitor interactions between biomolecules. Here, we focus on the techniques that are used for investigating the structure and interactions of nucleic acids (NAs). We present a brief overview of the most commonly used FRET microscopy techniques, their advantages and drawbacks. We list experimental approaches recently used for either in vitro or in vivo studies. Next, we summarize how FRET contributed to the understanding of pre-mRNA splicing and spliceosome assembly.
Impact of High Concentration Solutions on Hydraulic Properties of Geosynthetic Clay Liner Materials
Authors: Xue Qiang , Zhang Qian , Liu Lei
Published: November 2012

This study focuses on the impact of landfill high concentration solutions erosion on geosynthetic clay liner (GCL) materials permeability. The permeation tests on the GCL, submerged using different kinds of solutions with different concentrations, were carried out systematically by taking these chemical solutions as permeant liquids. Based on seasonal variations of ion concentrations in Chenjiachong landfill leachate (Wuhan Province), CaCl2, MgCl2, NaCl, and KCl were selected as chemical attack solutions to carry out experimental investigations under three concentrations (50 mM, 100 mM, 200 mM) and soak times (5, 10, and 20 days). The variation law of the GCL hydraulic conductivity under different operating conditions was analyzed. The relationship between GCL hydraulic conductivity, chemical solutions categories, concentrations, and soak times were further discussed. The GCL hydraulic conductivity, when soaked and permeated with high concentration chemical solutions, increases several times or exceeds two orders of magnitude, as compared with the permeation test under normal conditions that used water as the permeant liquid. This reveals that GCL is very susceptible to chemical attack. For four chemical solutions, the chemical attack effect on GCL hydraulic conductivity is CaCl2 > MgCl2 > KCl > NaCl. The impact of soak times on GCL hydraulic conductivity is the cooperative contribution of the liner chemical attack reaction and hydration swelling. A longer soak time results in a more advantageous hydration swelling effect. The chemical attack reaction restrains the hydration swelling of the GCL. Moreover, the GCL hydraulic conductivity exponentially decreases with the increased amplitude of thickness.
Therapeutic Applications of Nucleic Acids and Their Analogues in Toll-like Receptor Signaling
Authors: Gosu Vijayakumar , Basith Shaherin , Kwon O-Pil , Choi Sangdun
Published: November 2012

Toll-like receptors (TLRs) belong to a family of innate immune receptors that detect and clear invading microbial pathogens. Specifically intracellular TLRs such as TLR3, TLR7, TLR8 and TLR9 recognize nucleic acids such as double-stranded RNA, single-stranded RNA and CpG DNA respectively derived from microbial components. Upon infection, nucleic acid sensing TLRs signal within endosomal compartment triggering the induction of essential proinflammatory cytokines and type I interferons to initiate innate immune responses thereby leading to a critical role in the development of adaptive immune responses. Thus, stimulation of TLRs by nucleic acids is a promising area of research for the development of novel therapeutic strategies against pathogenic infection, allergies, malignant neoplasms and autoimmunity. This review summarizes the therapeutic applications of nucleic acids or nucleic acid analogues through the modulation of TLR signaling pathways.
Assessment of Fluorescent Particles for Surface Flow Analysis
Authors: Tauro Flavia , Mocio Gabriele , Rapiti Emiliano , Grimaldi Salvatore , Porfiri Maurizio
Published: November 2012

In this paper, a systematic performance assessment of the measurement system for surface flow analysis developed by our group in (Tauro et al., Sensors, 2010) is presented. The system is based on the detection of buoyant fluorescent microspheres through alow-cost apparatus, which incorporates light sources to elicit fluorescence response and a digital camera to identify the particles' transit. Experiments are conducted using green fluorescent particles and further tests are executed to evaluate the system performance forred and orange particles varying in emission wavelength, degree of biocompatibility, and cost. The influence of the following parameters on surface flow sensing using fluorescent beads is investigated: (i) distance of the light sources from the water surface, (ii) presence of an ad-hoc filter tuned at the particle emission wavelength, (iii) camera resolution and frame rate, (iv) flow regime, and (v) ambient light. Experimental results are used to inform implementation guidelines for surface flow analysis in natural environments.
A Metabolomic Approach to Clarifying the Effect of AST-120 on 5/6 Nephrectomized Rats by Capillary Electrophoresis with Mass Spectrometry (CE-MS)
Authors: Akiyama Yasutoshi , Takeuchi Yoichi , Kikuchi Koichi , Mishima Eikan , Yamamoto Yasuaki , Suzuki Chitose , Toyohara Takafumi , Suzuki Takehiro , Hozawa Atsushi , Ito Sadayoshi , Soga Tomoyoshi , Abe Takaaki
Published: November 2012

The oral adsorbent AST-120 is composed of spherical carbon particles and has an adsorption ability for certain small-molecular-weight compounds that accumulate in patients with chronic kidney disease (CKD). So far, very few compounds are known to be adsorbed by AST-120 in vivo. To examine the effect of AST-120 in vivo, we comprehensively evaluated the plasma concentrations of 146 compounds (61 anions and 85 cations) in CKD model rats, with or without four weeks of treatment with AST-120. By capillary electrophoresis with mass spectrometry, we identified 6 anions and 17 cations that were significantly decreased by AST-120 treatment. In contrast, we also identified 2 cations that were significantly increased by AST-120. Among them, 4 anions, apart from indoxyl sulfate and hippurate, and 19 cations were newly identified in this study. The plasma levels of N-acetyl-neuraminate, 4-pyridoxate, 4-oxopentanoate, glycine, γ-guanidinobutyrate, N-γ-ethylglutamine, allantoin, cytosine, 5-methylcytosine and imidazole-4-acetate were significantly increased in the CKD model compared with the sham-operated group, and were significantly decreased by AST-120 treatment. Therefore, these 10 compounds could be added as uremic compounds that indicate the effect of AST-120 treatment. This study provides useful information not only for identifying the indicators of AST-120, but also for clarifying changes in the metabolic profile by AST-120 treatment in the clinical setting.
Cellular Prion Protein: From Physiology to Pathology
Authors: Yusa Sei-ichi , Oliveira-Martins José B. , Sugita-Konishi Yoshiko , Kikuchi Yutaka
Published: November 2012

The human cellular prion protein (PrPC) is a glycosylphosphatidylinositol (GPI) anchored membrane glycoprotein with two N-glycosylation sites at residues 181 and 197. This protein migrates in several bands by Western blot analysis (WB). Interestingly, PNGase F treatment of human brain homogenates prior to the WB, which is known to remove the N-glycosylations, unexpectedly gives rise to two dominant bands, which are now known as C-terminal (C1) and N-terminal (N1) fragments. This resembles the β-amyloid precursor protein (APP) in Alzheimer disease (AD), which can be physiologically processed by α-, β-, and γ-secretases. The processing of APP has been extensively studied, while the identity of the cellular proteases involved in the proteolysis of PrPC and their possible role in prion biology has remained limited and controversial. Nevertheless, there is a strong correlation between the neurotoxicity caused by prion proteins and the blockade of their normal proteolysis. For example, expression of non-cleavable PrPC mutants in transgenic mice generates neurotoxicity, even in the absence of infectious prions, suggesting that PrPC proteolysis is physiologically and pathologically important. As many mouse models of prion diseases have recently been developed and the knowledge about the proteases responsible for the PrPC proteolysis is accumulating, we examine the historical experimental evidence and highlight recent studies that shed new light on this issue.
Running Loose or Getting Lost: How HIV-1 Counters and Capitalizes on APOBEC3-Induced Mutagenesis through Its Vif Protein
Authors: Münk Carsten , Jensen Björn-Erik , Zielonka Jörg , Häussinger Dieter , Kamp Christel
Published: November 2012

Human immunodeficiency virus-1 (HIV-1) dynamics reflect an intricate balance within the viruses’ host. The virus relies on host replication factors, but must escape or counter its host’s antiviral restriction factors. The interaction between the HIV-1 protein Vif and many cellular restriction factors from the APOBEC3 protein family is a prominent example of this evolutionary arms race. The viral infectivity factor (Vif) protein largely neutralizes APOBEC3 proteins, which can induce in vivo hypermutations in HIV-1 to the extent of lethal mutagenesis, and ensures the production of viable virus particles. HIV-1 also uses the APOBEC3-Vif interaction to modulate its own mutation rate in harsh or variable environments, and it is a model of adaptation in a coevolutionary setting. Both experimental evidence and the substantiation of the underlying dynamics through coevolutionary models are presented as complementary views of a coevolutionary arms race.
Soigner les adolescents difficiles
Authors: Nicolò Anna Maria
Published: November 2012

Résumé Il existe une spécificité du travail avec les adolescents, qui nécessite un aménagement du dispositif analytique classique. À partir d’études de cas d’adolescents difficiles, en situation de breakdown et de rupture de développement, l’auteur développe et illustre cette notion d’aménagement de cadre. Elle interroge la place de l’interprétation, sa spécificité dans le travail avec les adolescents, et l’intérêt de coupler le travail interprétatif avec d’autres outils pour aider le sujet à accéder à l’historicisation de ses vécus traumatiques.
« Ces angoisses ne sont pas les miennes »
Authors: Bonaminio Vincenzo
Published: November 2012

Résumé Cet article est le fruit d’une réflexion sur les angoisses et défenses persécutrices à l’adolescence, à partir du cas d’Osvaldo, suivi en analyse durant quatre années. L’article retrace les trois premières années du traitement et montre l’action de ces angoisses de persécution dans le tissage du transfert et du contre-transfert, ainsi que leur fonction d’intégration du Soi lorsque les menaces de désintégration et d’annihilation débordent le sujet.
Styles, outils et forces motrices dans la cure
Authors: Fabozzi Paolo
Published: November 2012

Résumé À partir d’une lecture croisée des travaux de Ph. Gutton et de V. Bonaminio, l’auteur aborde trois aspects interconnectés du travail analytique avec les patients adolescents, que sont les styles, les outils et les forces motrices à l’œuvre dans la cure. Se dessine en filigrane la spécificité de la posture de l’analyste d’adolescents, à même de se muer en objet intermédiaire, pour relancer une possibilité de penser et favoriser, chez le patient, l’expérience d’une intimité retrouvée avec soi-même.
Un domicile pour la chimère ?
Authors: Costis Angelique
Published: November 2012

Résumé Cet article propose un commentaire croisé des travaux de A. M. Nicolo et F. Richard, et pose la question des conditions de la cure en adolescence. La spécificité du positionnement de l’analyste est envisagée à partir de la figure mythologique de la chimère , personnage hybride pouvant représenter les capacités d’accueil du thérapeute d’adolescents : à même de tolérer une pause sur les frontières incertaines entre le Moi et le non-Moi, et de rendre possible l’émergence de processus de pensée originaux et de pensées paradoxales.
Brêves réflexions sur les résistances aux thérapies corporelles
Authors: Hochmann Jacques
Published: November 2012

Résumé Commentant une polémique actuelle sur le packing, cet article d’introduction relève les fantasmes archaïques suscités dans l’opinion par les thérapies corporelles.
L'Atelier des enveloppes
Authors: Calevoi Nicole , Thiry Solange
Published: November 2012

Résumé Nous interrogeons la pratique et l’articulation théorico-clinique d’un atelier à médiation dans un centre de jour. À travers le cas clinique de Maud, nous vous présentons le travail de collaboration entre l’artiste et les différents intervenants qui effectuent un travail psychanalytique à plusieurs autour de patients difficiles. L’aspect processuel du travail à médiation est complémentaire de l’approche verbale chez ces patients en manque de symbolisation.
Elèves et professeurs, nouveaux inventeurs, à leur insu
Authors: Montagne Yves-Félix
Published: November 2012

Résumé Il s’agit de proposer une lecture du couple emportements des élèves/réponses des professeurs, depuis le champ conceptuel de la psychanalyse, et de considérer ces faits comme des créations pulsionnelles, des trouvailles subjectives de sujets désirants. Ce postulat s’appuiera sur l’élaboration conceptuelle et praxique de Freud et J. Lacan, qui rend compte d’événements analogues aux éruptions des élèves et aux réponses des professeurs, survenant dans la pratique de la cure entre analyste et patient. Une telle position heuristique permettra d’établir l’hypothèse que certains élèves ont recours à l’acting out en cours et que des réponses qui surgissent chez leur professeur sont de l’ordre du « savoir y faire ». Dans cette perspective, les inventions adolescentes et leurs échos adultes sont les témoins d’une réalité scolaire nouvelle qui permet à des adolescents et à des professeurs de se construire l’un avec l’autre. Ces conduites seront pointées par une analyse interprétative du discours des sujets de la leçon quand ils parlent de ce qu’ils vivent.
Amour et subjectalisation
Authors: Monniello Gianluigi
Published: November 2012

Résumé Les parcours possibles des affects de la vie amoureuse, d’abord au temps de la naissance de l’objet, puis comme investissement de soi et de l’autre, pour se poursuivre enfin dans l’amour dit mûr, se télescopent dans les innombrables formes et dans l’intensité de l’amour de transfert. À partir de la dynamique transféro-contre-transférentielle à l’œuvre dans l’analyse d’Antonella, nous verrons comment la clinique illustre les nombreuses vicissitudes traversées par les adolescents, leurs solutions symptomatiques infinies, les innombrables souffrances de leur vie amoureuse, liées à la fidélité à l’identification primaire, à la force de ce lien aimé et haï, mais aussi, en même temps, à la réactivation des processus de subjectalisation et de subjectivation.
Once, se rencontrer, se parler et se dire adieu
Authors: Carbone Paola , Casini Elisa , Ferrari Anna
Published: November 2012

Résumé Les Urgences sont un des services sanitaires les plus fréquentés par les jeunes. Deux phénomènes principaux en cause : les accidents et les somatisations. Un point commun : un corps à la fois acteur et victime des troubles et des agirs adolescents. À partir d’une recherche menée dans cinq hôpitaux à Rome entre 2000 et 2002, et notamment au Service des Urgences de San Eugenio, nous proposons une réflexion sur la valeur clinique et la fonction évolutive d’un entretien clinique unique («  once  »). En tenant compte des différentes temporalités en jeu dans cet espace de rencontre, comme des expériences de crise et de surprise à l’œuvre, nous verrons comment l’entretien aux Urgences peut devenir l’occasion, le « risque créatif » d’une durée, d’une longue durée dans un instant, mais aussi d’un nouveau point de vue sur l’évènement vécu par l’adolescent, si nous savons accueillir sa temporalité paralysée et lui permettre de s’approprier sa propre histoire de vie.