bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fragile X–associated tremor ataxia syndrome in FMR1 gray zone allele carriers
Authors: Hall Deborah , Tassone Flora , Klepitskaya Olga , Leehey Maureen 
Published: December 2011

AbstractBackground:Carriers of fragile X mental retardation 1 (FMR1) repeat expansions in the premutation range (55–200 CGG repeats) often develop a syndrome of kinetic tremor, cerebellar ataxia, and parkinsonism; designated the fragile X–associated tremor ataxia syndrome (FXTAS). Neurological signs have not been reported in carriers of gray zone (45–54 CGG repeats) expansions.Methods/Results:We describe 3 patients with FMR1 gray zone alleles who meet diagnostic criteria for FXTAS.Conclusions:Our cases suggest that the definition of the FXTAS may need to be broadened to include individuals with FMR1 repeat expansions in the gray zone. These neurological signs may be due to elevated levels of expanded CGG repeat FMR1 mRNA in the gray zone carriers, similar to the changes seen in premutation carriers with FXTAS. © 2011 Movement Disorder Society
Catalytic Chain Transfer in Continuous Emulsion Polymerization
Authors: Smeets Niels M. B. , Jansen Tom G. T. , Heuts Johan P. A. , van Herk Alex M. , Meuldijk Jan 
Published: December 2011

AbstractIt is demonstrated that CCT‐mediated emulsion polymerization can successfully be carried out in a PSPC. Proper molecular weight control is achieved with only minor quantities of a cobalt(II) complex, illustrating the robustness and scalability of CCT. Despite the successful implementation of CCT in the PSPC, differences in the course of the polymerization and the final latex properties (in terms of the PSD/MWD) for batchwise and PSPC operation are observed. Backmixing occurs to some extend in the PSPC, which increases the steady state CCTA concentration in the column. Consequently, a higher chain transfer activity is observed than expected based on the corresponding batch experiments, which affects the course of the polymerization and the final latex properties.magnified image
Longitudinal and noninvasive assessment of emphysema evolution in a murine model using proton MRI
Authors: Zurek Magdalena , Boyer Laurent , Caramelle Philippe , Boczkowski Jorge , Crémillieux Yannick 
Published: December 2011

AbstractUltrashort echo time (550 μs) MR imaging was implemented to track the emphysema development in mice lung challenged with elastase. Two parameters, namely, signal intensity and T, were used to monitor the disease evolution. Nine mice were imaged before and at 24 h as well as at 3 and 8 weeks after elastase instillation. Five mice instilled with saline served as controls. At week 8, the mean normalized signal intensity ± SD was 0.89 ± 0.20 for healthy controls and 0.64 ± 0.10 for animals with emphysema. Similarly, a reduced value of T (1.27 ± 0.35 ms vs 0.96 ± 0.18 ms) was found in the emphysema group. The mean signal intensity drop and the reduction of T were prominent at 3 weeks following elastase instillation and stabilized between 3 and 8 weeks. The results indicated an excellent agreement between MR findings and histological morphometry (signal intensity, r = −0.78, P = 0.004; T, r = −0.78, P = 0.001). This result shows that proton MRI allows structural changes at alveolar level to be monitored longitudinally. This technique, applied routinely in preclinical trials will represent a valuable tool for assessment of drug therapy efficacy. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Stabilization of mixed tetrahedral elements at large deformations
Authors: Caylak Ismail , Mahnken Rolf 
Published: December 2011

SUMMARYThis paper presents stabilized mixed finite element formulations for tetrahedral elements at large deformations using volume and area bubble functions. To this end, the corresponding weak formulations are derived for the standard two‐field method, the method of incompatible modes and the enhanced strain method. Then, the weak formulations will be linearized. Furthermore, the matrix formulations for the weak formulations and its linearizations are summarized. The numerical results for incompressible rubber‐like materials using a Neo‐Hookean material law show the locking‐free performance and the drastic damping of the stresses for the new stabilized tetrahedral elements in finite deformation problems. This paper is an extension of the works published by the authors regarding small deformation problems for linear elasticity and plasticity. Copyright © 2011 John Wiley & Sons, Ltd.
Slight compressibility and sensitivity to changes in Poisson's ratio
Authors: Destrade M. , Gilchrist M.D. , Motherway J. , Murphy J.G. 
Published: December 2011

SUMMARYFinite element simulations of rubbers and biological soft tissue usually assume that the material being deformed is slightly compressible. It is shown here that, in shearing deformations, the corresponding normal stress distribution can exhibit extreme sensitivity to changes in Poisson's ratio. These changes can even lead to a reversal of the usual Poynting effect. Therefore, the usual practice of arbitrarily choosing a value of Poisson's ratio when numerically modelling rubbers and soft tissue will, almost certainly, lead to a significant difference between the simulated and actual normal stresses in a sheared block because of the difference between the assumed and actual value of Poisson's ratio. The worrying conclusion is that simulations based on arbitrarily specifying Poisson's ratio close to 1∕2 cannot accurately predict the normal stress distribution even for the simplest of shearing deformations. It is shown analytically that this sensitivity is caused by the small volume changes, which inevitably accompany all deformations of rubber‐like materials. To minimise these effects, great care should be exercised to accurately determine Poisson's ratio before simulations begin. Copyright © 2011 John Wiley & Sons, Ltd.
Proper generalized decomposition of time‐multiscale models
Authors: Ammar Amine , Chinesta Francisco , Cueto Elías , Doblaré Manuel 
Published: December 2011

SUMMARYModels encountered in computational mechanics could involve many time scales. When these time scales cannot be separated, one must solve the evolution model in the entire time interval by using the finest time step that the model implies. In some cases, the solution procedure becomes cumbersome because of the extremely large number of time steps needed for integrating the evolution model in the whole time interval. In this paper, we considered an alternative approach that lies in separating the time axis (one‐dimensional in nature) in a multidimensional time space. Then, for circumventing the resulting curse of dimensionality, the proper generalized decomposition was applied allowing a fast solution with significant computing time savings with respect to a standard incremental integration. Copyright © 2011 John Wiley & Sons, Ltd.
Reformulation of nodally integrated continuum elements to attain insensitivity to distortion
Authors: Krysl P. , Kagey H. 
Published: December 2011

SUMMARYThe nodally integrated continuum element (NICE) formulation is an assumed‐strain finite element technique derived from a weighted residual statement that weakly enforces both the balance equation and the kinematic equation. The original NICE formulation has a number of desirable attributes (e.g., resistance to volumetric locking), but, similar to classical finite elements, it is sensitive to a geometrical distortion of the finite element mesh. The present work analyzes the NICE technique from this viewpoint, the source of the sensitivity to the shape of the element is identified, and an improvement of the NICE formulation is proposed. We illustrate the performance of the revised NICE formulation on extremely distorted meshes. The tetrahedral meshes contain zero‐volume or negative‐volume elements, including slivers, and the new NICE formulation is shown to have the condition number of the stiffness matrix under control even in the presence of slivers. Furthermore, insensitivity to distortions is demonstrated for quadratic and cubic hexahedral elements. The proposed improvement confers robustness to all element shapes treated by the NICE formulation. The approximation properties of the original NICE formulation are preserved, in particular the improved version is also locking free, and at the same time, the need for stabilization also carries over. Copyright © 2011 John Wiley & Sons, Ltd.
Ion exchange technology for optical waveguides
Authors: Kufner Maria , Kufner Stefan 
Published: December 2011

AbstractThe term ‘integrated optics’ has been created more than 30 years ago and describes a family of technologies where light guiding structures are integrated on planar substrates. The concept corresponds to electronic integration, where lithographical tools are used to create structures in the micron range with submicron precision. One of the first reliable production processes for integrated optical waveguides was ion exchange in glass.
Three‐dimensional laser lithography
Authors: Thiel Michael , Hermatschweiler Martin 
Published: December 2011

AbstractIn the last decades micro‐ and nanotechnology have made enormous progress. One of the key success factors is the continuous improvement of lithographic techniques which are the driving forces of innovation in many industrial areas. So far, lithography on the sub‐micrometer scale has mostly been limited to planar objects. Trends towards further miniaturization and high‐density integration call for disruptive developments of production standards. The next logical step is to go from planar two‐dimensional lithography to the third dimension.
Preparation and thermal energy storage properties of poly(n‐butyl methacrylate)/fatty acids composites as form‐stable phase change materials
Authors: Sari Ahmet , Alkan Cemil 
Published: December 2011

AbstractThis work is focused on the preparation, characterization, and determination of thermal energy storage properties of poly(n‐butyl methacrylate) (PnBMA)/fatty acid composites as form‐stable phase change material (PCM). In the composite materials, the fatty acids act as latent heat storage material whereas PnBMA serves as supporting material, which prevents the leakage of the melted fatty acids. The maximum encapsulation ratio for all fatty acids was found to be 40 wt%. The composites that do not allow PCM leakage in melted state were identified as form‐stable PCMs. The compatibility of fatty acids with PnBMA is investigated by optical microscopy (OM) and Fourier Transform Infrared (FT‐IR) spectroscopy. Thermal properties and thermal reliability of the form‐stable composite PCMs were determined using differential scanning calorimetry (DSC). DSC analysis revealed that the form‐stable composite PCMs had melting temperatures between 29.62°C and 53.73°C and latent heat values between 67.23 J/g and 87.34 J/g. Thermal stability of the composite PCMs was studied by thermal gravimetric (TG) analysis and the results indicated that the form‐stable PCMs had good thermal stability. In addition, thermal cycling test showed that the composite PCMs had good thermal reliability with respect to the changes in their thermal properties after accelerated 5,000 thermal cycling. On the basis of all results, it was also concluded that the prepared form‐stable composite PCMs had important potential for many thermal energy storage applications such as solar space heating of buildings by using wallboard, plasterboard or floors integrated with PCM. POLYM. COMPOS., 2012. © 2011 Society of Plastics Engineers
Effects of water absorption on mechanical properties of hemp fiber composites
Authors: Shahzad Asim 
Published: December 2011

AbstractEffects of water absorption on mechanical properties of hemp fiber composites have been studied. Finite difference method modeling of water absorption in these composites showed the diffusion to be Fickian in nature. The residual tensile and flexural properties showed immediate decline following immersion in water, the loss in modulus being more pronounced than the loss in strength. The fracture of tensile tested composites following immersion in water was found to be more ductile than brittle, which showed the evidence of shear stresses being more significant in these conditions. For impact damaged composites immersed in water, most of the degradation in residual tensile properties occurred within first 100 h of immersion in water at same impact energy level and further immersion in water for up to 400 h did not result in any further degradation. No deterioration in fatigue strength and fatigue sensitivity of composites following immersion in water was observed. POLYM. COMPOS., 2012. © 2011 Society of Plastics Engineers
Effect of electron beam irradiation on the mechanical, thermal, and dynamic mechanical properties of flyash and nanostructured fly ash waste polyethylene hybrid composites
Authors: Satapathy Sukanya , Nag Ahin , Nando Golok Bihari 
Published: December 2011

AbstractThe effect of electron beam irradiation on the technical properties of fly ash (FA) and nano fly ash (NFA)‐filled waste polyethylene (WPE) composites have been investigated in this article. It is observed that the FA/NFA at 5 wt% imparted enhanced technical properties. The modified composites were prepared by three different methods (1) modification of WPE matrix first by grafting with maleic anhydride (MA) and preparing the composite (2) Preparing WPE‐FA/NFA composites and subjecting to electron beam irradiation. (3) Subjecting the FA/NFA to electron beam radiation first and then preparing composites with WPE. Of the three methods, the composite prepared and then electron beam irradiated gave the best balance in the physico‐mechanical properties. The tensile and flexural strength of WPE increased from 21.2 MPa and 25.4 MPa to 33.0 MPa (57.8%) and 45.8 MPa (72%) respectively at 5 wt% FA‐filled WPE composites, which further increased to 34.5 MPa (65%) and 47.7 MPa (87.8%) respectively with 5 wt% of NFA‐filled WPE composites, after electron beam irradiation. The thermal stability was enhanced upon electron beam irradiation of the composites. The dynamic mechanical properties reveal that the storage modulus reaches the highest value for the irradiated composite corroborating with the flexural modulus throughout the temperature range studied. The fractured surfaces were examined under SEM and were correlated with the mechanical properties. The results indicate that FA/NFA reinforced WPE composites act as an excellent stress raisers preventing crack propagation and enhancing the performance properties on electron beam irradiation. POLYM. COMPOS., 2012. © 2011 Society of Plastics Engineers
Characterization of the human primary visual cortex and cerebellum proteomes using shotgun mass spectrometry‐data‐independent analyses
Authors: Martins‐de‐Souza Daniel , Guest Paul C. , Guest Francesca L. , Bauder Corinna , Rahmoune Hassan , Pietsch Sandra , Roeber Sigrum , Kretzschmar Hans , Mann David , Baborie Atik , Bahn Sabine 
Published: December 2011

AbstractWe present the first characterization of the human occipital lobe (primary visual cortex) and cerebellum proteomes. Proteins were identified using a combination of gel electrophoresis and data‐independent nanoflow liquid chromatography mass spectrometry (nLC‐MSE). The resulting data sets comprised 391 and 330 unique proteins in occipital lobe and cerebellum, respectively, present in at least 75% of the analyzed samples with 297 proteins found in common. These proteins have been associated previously with conditions, such as neurological disorder, progressive motor neuropathy, Parkinson's disease and schizophrenia. The unique proteins identified in the occipital lobe included the interesting finding of growth hormone and several members of the Ca2+‐dependent calmodulin kinase and serine/threonine protein phosphatase families. The complete mapping of these and other brain proteomes may help in the elucidation of neurological processes and identify potential targets for therapeutic strategies.
Minimum ignition energy for micro and nano flash powders
Authors: Azhagurajan A. , Selvakumar N. , Mohammed Yasin M. 
Published: December 2011

AbstractThe minimum ignition energy (MIE) of dust clouds is required to assess the electrostatic ignition risk. Recently, the growing number of accidents shows that fire and explosions occurring in fireworks industry are due to electrostatic discharge (ESD). The objective of the this paper is to discuss the various practical concerns during the handling of flash powders of various compositions containing potassium nitrate, sulfur, and aluminum in fireworks. These powders form dust clouds and cause fires and explosions because the MIEs of these dust clouds are very low. This study is carried out with powders of various sizes ranging from micron and nanometer. The measurements are done by using a 1.2‐L Hartmann apparatus. The experimental results show that the MIEs for flash powders are in the range from 89.2 to 19.8 mJ for micron‐ and nano‐sized particles. The experimental results are given for various changes, such as: electrode gap, electrode material, and dust concentration, dust composition, etc. If the nano flash powder is mixed with micron powders, the MIE is greatly reduced, and it becomes extremely combustible. Therefore, it is imperative for fireworks manufacturers, or anyone handling these dusts, to take precautionary measures to prevent fires and explosions involving ESDs. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2012
The dimensions and analysis of safety culture
Authors: Wang Chen‐Hua , Liu Yu‐Jung 
Published: December 2011

AbstractThis article (a) summarizes the literature concerning the dimensions of safety culture, (b) describes a method used to develop a questionnaire to identify the importance of these dimensions, and (c) includes a table of results that give the ranking of 18 safety culture dimensions. The results show that the most important dimensions include safety behaviour, awareness, contractor management, commitment, and training. A detailed analysis of the results show that the employees with the best culture recognize the importance of safety and safety regulations, they especially value life, and they consider safety as everyone's responsibility. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011
Recent progress of efficient deep UV‐LEDs by plasma‐assisted molecular beam epitaxy
Authors: Liao Yitao , Kao Chen‐kai , Thomidis C. , Moldawer A. , Woodward J. , Bhattarai D. , Moustakas T. D. 
Published: December 2011

AbstractWe report the development of efficient AlGaN‐based deep ultraviolet (UV) LEDs emitting in the wavelength range from 320 nm to 265 nm by plasma‐assisted molecular beam epitaxy (MBE). By growing the AlGaN well layers under Ga‐rich conditions to produce strong band structure potential fluctuations, the internal quantum efficiency (IQE) of the quantum wells, which are used as the active region of the UV LEDs, was found to be as high as 32%. Unpackaged deep UV‐LEDs emitting at 273 nm were found to have an optical output power of 0.35 mW and 1.3 mW under DC and AC injection current of 20 mA and 100 mA respectively. The maximum external quantum efficiency under DC injection was measured to be 0.4%. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Broadening of photoluminescence for inhomogeneous polar and non‐polar InGaN/GaN quantum wells
Authors: Gladysiewicz Marta , Kudrawiec Robert 
Published: December 2011

AbstractThe model of a ‘random’ quantum well (QW) [M. Gladysiewicz and R. Kudrawiec, J. Phys.: Condens. Matter 22, 485801 (2010)] has been applied to generate low temperature photoluminescence (PL) spectra for polar and non‐polar InGaN QWs dedicated for blue and green emitters. In order to simulate QW inhomogeneities in this model, it was assumed that the QW width, barrier widths and indium concentration vary with a Gaussian distribution where the nominal QW width, barrier widths and indium concentration correspond to the mean value in this distribution and their fluctuations correspond to the deviation from the mean value. In PL spectrum such a QW is represented by a Lorentz‐like peak with the homogeneous broadening. For an inhomogeneous QW the PL spectrum is built from such PL peaks obtained for thousands random QWs. Such an approach allows to investigate the influence of QW inhomogeneities on the broadening of the PL. In this paper it is clearly shown that the polarization‐related electric field enhances the broadening of the PL. A reduction of built‐in electric field in InGaN QWs can be a promising way to improve the homogeneity of light emission from this system. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carrier transport mechanism of AlGaN/GaN Schottky barrier diodes with various Al mole fractions
Authors: Ha Woo Jin , Chhajed Sameer , Chavan Ashonita , Lee Jae‐Hoon , Kim Ki‐Se , Kim Jong Kyu 
Published: December 2011

AbstractThe evolution of the dominant carrier transport mechanism of Alx Ga1‐xN/GaN Schottky barrier diodes with increasing Al mole fraction x (x = 0.2, 0.3, 0.4, and 0.5) is investigated. The Schottky barrier height (SBH) linearly increases with the work function of Schottky metal with the slope factor of ∼0.5 irrespective of x. The SBH, the ideality factor, and the reverse leakage current, however, show an increasing deviation from the predicted values given by the thermionic‐emission theory as x increases. The XPS analysis reveals enhanced predominant incorporation of oxygen donors and an increase in the energy band bending at the surface of AlGaN with increasing x, indicating that the carrier transport by tunnelling through the thin, heavily doped Schottky barrier becomes dominant. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Physicochemical properties of starch isolated from Antiaris africana seeds in comparison with maize starch
Authors: Nwokocha Louis M. , Nwokocha Kate E. , Williams Peter A. 
Published: December 2011

AbstractAntiaris africana seeds yielded 29.6% starch which showed appreciable high contents of ash, protein, and fat. The average diameter of A. africana starch granules was 3.98 µm compared to 8.93 µm for maize starch. A. africana starch had a C‐type XRD pattern and crystallinity of 41.5%. A. africana starch had higher AM content (24.1%) than maize starch (20.9%). The gelatinization onset temperature of A. africana starch (66.7°C) was higher than maize starch (63.1°C), but its gelatinization temperature range (8.57°C) and enthalpy (13.97 J/g) were lower than the values for maize starch (14.02°C, 14.65 J/g). The pasting temperature (Pt) and setback (Vs) were lower and breakdown (Vb) higher for A. africana starch (Pt = 82.5°C, Vs = 173.8 RVU, and Vb = 121.42 RVU) than for maize starch (Pt = 84.9°C, Vs = 183.73 RVU, and Vb = 78.58 RVU). The GPC analysis gave Mw of 2.18 × 107 g/mol and radius of gyration of 95.1 nm for Antiaris starch. Antiaris starch paste exhibited poor freeze‐thaw stability but its small granule size indicates potential for application as dusting starch.
Helping men to help themselves
Authors: Kirby Roger 
Published: December 2011

AbstractOne of our avowed missions in Trends is to help our readers to ‘help men to help themselves’. The trouble is that many of us, and even more of our patients, tend to ‘help ourselves’ rather too liberally to over‐large meals, tasty treats and festive tipples over the Christmas period. The inevitable result is an unwelcome expansion of abdominal girth and rise of body mass index (BMI) in the New Year. It does no harm, therefore, for us to go into the Christmas holiday with some sobering pieces of evidence in the front of our mind. Copyright © 2011 Wiley Interface Ltd
Role of radiological imaging for the evaluation of haematuria
Authors: Patel Dhruv , Patel Uday 
Published: December 2011

AbstractHaematuria is a sign that can arise from a constellation of disorders, ranging from urinary tract infection to invasive malignancy. The authors review imaging modalities for the investigation of haematuria and highlight how imaging is key to the exclusion of potentially serious causative aetiologies. Copyright © 2011 Wiley Interface Ltd