bluuebunny/crossref_metadata_2025_split huggingface dataset:
Initial Particle Morphology Development in Ziegler‐Natta Propylene Polymerization Tracked with Stopped‐Flow Technique
Authors: Taniike Toshiaki , Thang Vu Quoc , Binh Nguyen Tien , Hiraoka Yuichi , Uozumi Toshiya , Terano Minoru 
Published: January 2011

AbstractIn this study, the particle morphology development at the very initial stage of propylene polymerization using a spherical Mg(OEt)2‐based ZN catalyst was precisely tracked by applying stopped‐flow and short‐time slurry polymerizations. Electron microscope observation and mercury porosimetry derived a comprehensive view of the initial particle morphology development. The polymer first filled macropores, which were mainly located in the middle layer of the catalyst particles, then caused the fragmentation of the middle layer, and finally triggered the fragmentation of the particle core in a stepwise manner. Thus, key effects of the layered catalyst architecture and spatial distribution of macropores were discovered on the initial morphology control of catalytic olefin polymerization. magnified image
Influence of the Recycling Process on the Fire‐Retardant Properties of PP/EPR Blends
Authors: Casetta Mathilde , Delaval Damien , Traisnel Michel , Bourbigot Serge 
Published: January 2011

AbstractThe fire‐retardant properties of a recycled poly(propylene)‐based material were investigated and compared to the non‐recycled formulation. An intrinsic intumescent system and zinc borate were used to flame‐retard these polymers. By mass loss calorimetry, the best results were obtained with 20 wt.‐% of additives. Synergisms between AP765 and ZB were observed in the non‐recycled blends but not in the recycled ones. Solid‐state NMR showed that chemical reactions during the decomposition process were leading to the formation of borophosphates, reinforcing the efficiency of the intumescent char. From a ‘physical’ point of view, it was shown that the fire retardant properties of the materials are related to the formation speed of the intumescent structure and not on the char thickness. magnified image
On singular elliptic equations involving a concave term and critical Caffarelli‐Kohn‐Nirenberg exponent
Authors: Bouchekif Mohammed , Matallah Atika 
Published: January 2011

AbstractIn this paper, we establish the existence of multiple positive solutions for singular elliptic equations involving a concave term and critical Caffarelli‐Kohn‐Nirenberg exponent. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
Tunable Metal‐Enhanced Fluorescence by Stimuli‐Responsive Polyelectrolyte Interlayer Films
Authors: Ma Ning , Tang Fu , Wang Xiaoyu , He Fang , Li Lidong 
Published: January 2011

AbstractIn this paper, we report on the tunable metal‐enhanced fluorescence (MEF) of Ag nanostructures. Because of the good MEF properties of the highly dendritic Ag nanostructures, we obtained an increase of up to 25 times for the weak fluorescence of porphyrin molecules (Por4–). More importantly, by the introduction of a stimulus‐responsive PAA/PDDA multilayer film as an interlayer, the distance between the fluorophores and the Ag nanostructures could be tuned by immersing the substrates into solutions of different ionic strength or pH. The MEF behavior of the composite films could thus be tuned in a controlled manner, because of the distance dependent nature of the MEF effects. magnified image
Conformation of the tridimensional structure of 1,2,3,4,6‐pentagalloyl‐β‐D‐glucopyranose (PGG) by 1H NMR, NOESY and theoretical study and membrane interaction in a simulated phospholipid bilayer: a first insight
Authors: Beretta Giangiacomo , Artali Roberto , Caneva Enrico , Maffei Facino Roberto 
Published: January 2011

Abstract1,2,3,4,6‐Penta‐O‐galloyl‐β‐D‐glucopyranose (PGG) is a polyphenolic compound found in substantial amounts in a number of medicinal herbs. We report (i) its conformational analysis by solution NMR and molecular dynamics calculation and (ii) theoretical study of its interaction with a model membrane bilayer. The galloyl groups B and E appear to play important roles in the interaction with the phospholipid bilayer. Copyright © 2011 John Wiley & Sons, Ltd.
NMR analysis of conformationally dependent nJC, H and nJC, C in the trisaccharide α‐L‐Rhap‐(1 → 2)[α‐L‐Rhap‐(1 → 3)]‐α‐L‐Rhap‐OMe and a site‐specifically labeled isotopologue thereof
Authors: Jonsson K. Hanna M. , Pendrill Robert , Widmalm Göran 
Published: January 2011

AbstractAn array of NMR spectroscopy experiments have been carried out to obtain conformationally dependent 1H,13C‐ and 13C,13C‐spin–spin coupling constants in the trisaccharide α‐L‐Rhap‐(1 → 2)[α‐L‐Rhap‐(1 → 3)]‐α‐L‐Rhap‐OMe. The trisaccharide was synthesized with 13C site‐specific labeling at C2′ and C2″, i.e. in the rhamnosyl groups in order to alleviate 1H spectral overlap. This facilitated the measurement of a key trans‐glycosidic proton–proton cross‐relaxation rate using 1D 1H,1H‐T‐ROESY experiments as well as a 3JC, H coupling employing 1D 1H,13C‐long‐range experiments, devoid of potential interference from additional J coupling. By means of both the natural abundance compound and the 13C‐labeled sample 2D 1H,13C‐J‐HMBC and 1H,13C‐HSQC‐HECADE NMR experiments, total line‐shape analysis of 1H NMR spectra and 1D 13C NMR experiments were employed to extract 3JC, H, 2JC, H, 3JC, C, and 1JC, C coupling constants. The 13C site‐specific labeling facilitates straightforward determination of nJC, C as the splitting of the 13C natural abundance resonances. This study resulted in eight conformationally dependent coupling constants for the trisaccharide and illustrates the use of 13C site‐specific labeling as a valuable approach that extends the 1D and 2D NMR methods in current use to attain both hetero‐ and homonuclear spin–spin coupling constants that subsequently can be utilized for conformational analysis. Copyright © 2011 John Wiley & Sons, Ltd.
Quantifying cortical bone water in vivo by three‐dimensional ultra‐short echo‐time MRI
Authors: Rad Hamidreza Saligheh , Lam Shing Chun Benny , Magland Jeremy F. , Ong Henry , Li Cheng , Song Hee Kwon , Love James , Wehrli Felix W. 
Published: January 2011

AbstractBone contains a significant fraction of water that is not detectable with ordinary Cartesian imaging sequences. The advent of ultra‐short echo‐time (UTE) methods has allowed the recovery of this submillisecond T2* water. In this work, we have developed a new three‐dimensional hybrid‐radial ultra‐short echo‐time (3D HRUTE) imaging technique based on slab selection by means of half‐sinc pulses, variable‐TE slice encoding and algorithms for quantification. The protocol consists of collecting two datasets differing in TR, from which T1 is extracted, which is needed for quantification. Unlike T2*, which has been found to vary within a narrow range and does not require individual correction, T1 is critically subject dependent (range, 100–350 ms). No soft‐tissue suppression was used to preserve the signal‐to‐noise ratio of the short‐T2 bone water protons or to minimize the loss of relatively mobile water in large pores. Critical for quantification is correction for spatial variations in reception field and selection of the endosteal boundary for inclusion of pixels in the bone water calculation, because of the ruffled boundary stemming from trabecularization of the endosteal surface. The reproducibility, evaluated in 10 subjects covering the age range 30–80 years, yielded an average coefficient of variation of 4.2% and an intraclass correlation coefficient of 0.95, suggesting that a treatment effect on the order of 5% could be detected in as few as 10 subjects. Lastly, experiments in specimens by means of graded deuterium exchange showed that approximately 90% of the detected signal arises from water protons, whose relaxation rates (1/T1 and 1/T2*) scale linearly with the isotopic volume fraction of light water after stepwise exchange with heavy water. The data thus show conclusively that the method quantifies water even though, in vivo, no distinction can be made between various fractions, such as collagen‐bound vs pore‐resident water. Copyright © 2011 John Wiley & Sons, Ltd.
Age‐dependent brain temperature decline assessed by diffusion‐weighted imaging thermometry
Authors: Sakai Koji , Yamada Kei , Mori Susumu , Sugimoto Naozo , Nishimura Tsunehiko 
Published: January 2011

AbstractBrain metabolism declines with age, but cerebral blood flow (CBF) is less age dependent. We therefore hypothesized that the brain temperature would decline with age, and measured the temperatures of the lateral ventricles in healthy volunteers. Diffusion‐weighted imaging (DWI) data from 45 healthy volunteers [mean (± standard deviation) age, 30.6 ± 8.66 years; range, 19–56 years] were used for this study. The temperature of water molecules is directly related to the diffusion coefficient, so that the temperature of cerebrospinal fluid can be measured using DWI. Temperature was calculated using the equation, T ( °C) = 2256.74/ln(4.39221/D) – 273.15, where D is the diffusion coefficient. The lateral ventricles were manually extracted by an experienced neuroradiologist on b0 images. The mean ventricular temperature was determined from the distribution function of the temperature of all selected voxels. The mean lateral ventricular temperature in healthy volunteers showed a linear decrease with age (correlation coefficient R2 = 0.8879; p < 0.01), presumably caused by an asynchronous decline in brain metabolism and CBF. DWI‐based thermometry demonstrates that ventricular temperature declines with the normal aging process. Further study is warranted to define the relationships between temperature, metabolism and circulation. Copyright © 2011 John Wiley & Sons, Ltd.
Comparison of hyperpolarized 3He MRI with Xe‐enhanced computed tomography imaging for ventilation mapping of rat lung
Authors: Santyr Giles E. , Couch Marcus J. , Lam Wilfred W. , Ouriadov Alexei , Drangova Maria , McCormack David G. , Holdsworth David W. 
Published: January 2011

AbstractLung ventilation was mapped in five healthy Brown Norway rats (210–377 g) using both hyperpolarized 3He MRI and Xe‐enhanced computed tomography (Xe‐CT) under similar ventilator conditions. Whole‐lung measurements of ventilation r obtained with 3He MRI were not significantly different from those obtained from Xe‐CT (p = 0.1875 by Wilcoxon matched pairs test). The ventilation parameter r is defined as the fraction of refreshed gas per unit volume per breath. Regional ventilation was also measured in four regions of the lung using both methods. A two‐tailed paired t‐test was performed for each region, yielding p > 0.05 for all but the upper portion of the right lung. The distribution of regional ventilation was evaluated by calculating ventilation gradients in the superior/inferior (S/I) direction. The average S/I gradient obtained using the 3He MRI method was found to be 0.17 ± 0.04 cm−1, whereas the average S/I gradient obtained using the Xe‐CT method was found to be 0.016 ± 0.005 cm−1. In general, S/I ventilation gradients obtained from both methods were significantly different from each other (p = 0.0019 by two‐tailed paired t‐test). These regional differences in ventilation measurements may be caused by the manner in which the gas contrast agents distribute physiologically and/or by the imaging modality. Copyright © 2011 John Wiley & Sons, Ltd.
Bone‐guided regeneration: from inert biomaterials to bioactive polymer (nano)composites
Authors: Barone D. T.‐J. , Raquez J.‐M. , Dubois Ph. 
Published: January 2011

AbstractNatural bone is a unique nanostructured material made of collagen fibre matrix and hydroxyapatite (HA) nanocrystals, providing mechanical support and protection from the vertebrate skeleton. However, in severe cases like bone‐deficiencies, bone needs to be “externally” repaired. Initially, different biological solutions were developed in bone‐guided regeneration. However, due to the limitations with the existing biological grafts, a lot of researches have been devoted toward biomaterials including metals, ceramics, and polymers. On the basis of the interface reactions between the implant and the surrounding tissues, these biomaterials may be classified as “nearly inert” or bioactive. Interestingly, the bioactive materials exhibit a specific biological response, leading to the formation of a natural bonding junction between the bone and the implant during bone regeneration. Recently, a special attention has been paid to a new generation of bioactive materials, i.e. (nano)structured biomaterials composed of a bioresorbable polymer matrix reinforced with bioactive inorganic compounds. While (bio)ceramic component provides the bioactivity, these materials can be readily engineered in such a way that their resorption rate in the body match the formation rate of the new tissue. This review hence reports the different biological and non‐biological solutions developed in bone‐guided regeneration, with a special emphasis on polymer‐based materials, and our recent results obtained in osseointegration The bone physiology, and its natural regeneration are also described. Copyright © 2011 John Wiley & Sons, Ltd.
Characteristics and outcome of radiation and chemotherapy‐related mucoepidermoid carcinoma of the salivary glands
Authors: Verma Jonathan , Teh Bin S. , Paulino Arnold C. 
Published: January 2011

AbstractBackgroundMucoepidermoid carcinoma (MEC) of the salivary glands has been reported to occur in patients previously treated with chemotherapy and/or radiation. The purpose of our study is to review the patient, tumor, and treatment characteristics of patients who develop a treatment‐related MEC.ProcedureA PubMed search of English language articles was performed using the keywords and MeSH terms: mucoepidermoid, salivary gland, radiation‐induced, second malignancy, radiotherapy, and chemotherapy.ResultsThe search yielded 23 articles describing 58 patients who received chemotherapy and/or radiotherapy (RT) and subsequently developed MEC. The most common initial diagnoses were acute lymphoblastic leukemia (n = 18), acne (n = 9), and Hodgkin lymphoma (n = 6). Patients were divided into three groups according to chemotherapy and RT treatment: chemotherapy alone (n = 14), RT alone (n = 14), or chemotherapy and RT (n = 30). The parotid gland was the most common site for secondary MEC. Latent time (LT) to development of MEC from initial tumor treatment was significantly shorter in the patients treated with chemotherapy ± RT versus RT alone (7.9 years vs. 27.2 years, P < 0.01). The most common treatment for MEC was surgery alone followed by surgery and postoperative RT. The 2‐ and 5‐year overall survival rates were 98% and 93.4% while the 2‐ and 5‐year locoregional control rates were 97.7% and 92.5%, respectively. There was no difference in survival or locoregional control between groups exposed to RT alone, chemotherapy alone, or chemotherapy with RT for the initial tumor.ConclusionRadiation and chemotherapy‐related MEC has an excellent prognosis. Pediatr Blood Cancer 2011; 57: 1137–1141. © 2011 Wiley Periodicals, Inc.
Echocardiographic surveillance for asymptomatic late‐onset anthracycline cardiomyopathy in childhood cancer survivors
Authors: Abosoudah Ibraheem , Greenberg Mark L. , Ness Kirsten K. , Benson Lee , Nathan Paul C. 
Published: January 2011

AbstractBackgroundThe optimal frequency of echocardiographic surveillance in asymptomatic childhood cancer survivors exposed to anthracyclines has not been established. We evaluated the effectiveness of performing surveillance echocardiograms according to the Children's Oncology Group's (COG) Long‐Term Follow‐Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers in survivors ≥1 year from concluding therapy.MethodsWe reviewed all children treated at our institution with anthracycline chemotherapy from 1995 to 2003. We assessed the frequency of abnormal echocardiograms according to risk groups defined in the COG guidelines, and evaluated the risk factors for an abnormal echocardiogram using Cox proportional hazards modeling.ResultsAt least one echocardiogram was completed by 469/603 (77.8%) eligible survivors. Mean diagnosis age was 7.7 (SD = 4.6) years. Mean cumulative doxorubicin‐equivalent dose was 205 mg/m2 (SD = 115). Survivors completed 1,013 echocardiograms (median = 2, range = 1–10) beyond 1 year after concluding therapy. Seventy‐nine (16.8%) survivors had an abnormal echocardiogram at a median of 2.9 years (range 0.01–9.8) from 1 year after concluding therapy. Anthracycline dose >300 mg/m2 (hazard ratio [HR] 3.00; 95% CI 1.51–5.98), age 1–4 years at treatment (HR 1.89; 95% CI 1.08–3.31) and radiation to a field involving the heart (HR 1.73; 95% CI 1.08–2.76) predicted an increased risk of an abnormal echocardiogram; however, even survivors in the lower COG risk groups demonstrated abnormalities.ConclusionPeriodic echocardiographic surveillance in childhood cancer survivors can yield abnormalities that require further evaluation. Abnormalities may become evident as early as 1 year after the conclusion of therapy and can impact even those survivors considered to be at low risk. Pediatr Blood Cancer 2011; 57: 467–472. © 2011 Wiley‐Liss, Inc.
Internal structure of the Green Lake 5 rock glacier, Colorado Front Range, USA
Authors: Leopold M. , Williams M.W. , Caine N. , Völkel J. , Dethier D. 
Published: January 2011

ABSTRACTInformation about the internal structure of rock glaciers is needed to understand their reaction to ongoing climate warming. Three different geophysical techniques—shallow seismic refraction, ground‐penetrating radar (GPR) and electrical resistivity tomography—were used to develop a detailed subsurface model of the Green Lake 5 rock glacier in the Colorado Front Range, USA. Below a thin zone of fine sediments and soils (0.7 – 1‐m thickness; 0 – 20 kΩm and 320 – 370 m s−1), a 1 – 3‐m thick zone with low p‐wave velocities (790 – 820 m s−1) and high electrical resistivity (20 – 100 kΩm) is interpreted as the ice‐free, blocky active layer with large void spaces. The data corroborate strong reflections of the GPR signals which travel at this depth at 0.11 m ns−1. A third layer that extends from depths of 1 – 3 m to about 5 m is characterised by lower electric resistivities (5 – 20 kΩm) and has lower electromagnetic wave velocities (0.65 m ns−1), representing unfrozen, finer and wetter sediments. At around 5‐m depth, the measured physical parameters change drastically (vp = 3200 – 3300 m s−1, 50 – 150 kΩm, vGPR = 0.15 m ns−1), showing an ice‐rich permafrost zone above the bedrock. This model of the internal structure was used to evaluate an existing hydrological flowpath model based on the hydrochemical properties of water outflow from the rock glacier. Copyright © 2011 John Wiley & Sons, Ltd.
Protein structure prediction using a docking‐based hierarchical folding scheme
Authors: Kifer Ilona , Nussinov Ruth , Wolfson Haim J. 
Published: January 2011

AbstractThe pathways by which proteins fold into their specific native structure are still an unsolved mystery. Currently, many methods for protein structure prediction are available, and most of them tackle the problem by relying on the vast amounts of data collected from known protein structures. These methods are often not concerned with the route the protein follows to reach its final fold. This work is based on the premise that proteins fold in a hierarchical manner. We present FOBIA, an automated method for predicting a protein structure. FOBIA consists of two main stages: the first finds matches between parts of the target sequence and independently folding structural units using profile–profile comparison. The second assembles these units into a 3D structure by searching and ranking their possible orientations toward each other using a docking‐based approach. We have previously reported an application of an initial version of this strategy to homology based targets. Since then we have considerably enhanced our method's abilities to allow it to address the more difficult template‐based target category. This allows us to now apply FOBIA to the template‐based targets of CASP8 and to show that it is both very efficient and promising. Our method can provide an alternative for template‐based structure prediction, and in particular, the docking‐basedranking technique presented here can be incorporated into any profile–profile comparison based method. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Spectrally and time‐resolved cathodoluminescence microscopy of semipolar InGaN SQW on (11$\overline {2} $2) and (10$\overline {1} $1) pyramid facets
Authors: Metzner Sebastian , Bertram Frank , Karbaum Christopher , Hempel Thomas , Wunderer Thomas , Schwaiger Stephan , Lipski Frank , Scholz Ferdinand , Wächter Clemens , Jetter Michael , Michler Peter , Christen Jürgen 
Published: January 2011

AbstractSemipolar InGaN/GaN single quantum wells (SQWs) grown on {11$\overline {2} $2} planes of an inverted pyramid surface and {10$\overline {1} $1} facets of single self assembled pyramids have been studied by spatially, spectrally, and time‐resolved cathodoluminescence (CL) microscopy. Mappings of local spectra and local transients provide the distribution of spectral and time‐resolved luminescence properties by peak wavelength images, time delayed CL images (TDCLIs), and initial lifetime maps. The SQW on inverse pyramids exhibit strong local differences in recombination kinetics – two orders of magnitude change in initial lifetime – correlated with a giant shift in emission energy of ∼1 eV along a facet. For single pyramids a migration process of indium adatoms from the upper facet to the edges leads to an emission of longer wavelengths at the edges and shorter wavelengths at the upper facet with respect to the base.
Assessment of the Met Office dust forecast model using observations from the GERBILS campaign
Authors: Johnson B. T. , Brooks M. E. , Walters D. , Woodward S. , Christopher S. , Schepanski K. 
Published: January 2011

AbstractThis paper uses aircraft, ground‐based and satellite observations to assess the performance of Met Office dust forecasts during the Geostationary Earth Radiation Budget Intercomparison of Long‐wave and Short‐wave radiation (GERBILS) campaign. The dust forecasts were produced from a 20 km resolution limited‐area numerical weather prediction configuration of the Met Office Unified Model, based over North Africa. Dust uplift was modelled using two modified versions of the Woodward (2001) dust parametrization scheme. The model produced widespread dust over the Sahara desert in response to synoptically driven strong wind events. The modelled aerosol size distribution and short‐wave optical properties compared well with aircraft in situ measurements and retrievals from the Aerosol Robotic Network (AERONET). Better size distributions and extinction coefficients were achieved by fixing the emitted dust size distribution rather than attempting to predict this dynamically. The two versions performed similarly compared to observations of other variables. The interaction of dust with short‐wave and long‐wave radiation compared well with aircraft observations when scaled to allow for local differences in Aerosol Optical Depth (AOD). AODs were on average 50–100% too high over south‐western parts of the Sahara but 20–50% too low over the Sahel when compared to AERONET sites, aircraft profile estimates and satellite retrieval products. This implicated excessive dust emission over central parts of the Sahara and insufficient dust emissions from the Bodélé depression and semi‐arid regions on the southern border of the Sahara. These biases were linked to potential errors in wind speed, soil texture, soil moisture and vegetation, and possible limitations in the dust parametrization, such as the lack of an observationally constrained or geomorphologically based preferential source term. Copyright © 2011 Royal Meteorological Society and Crown copyright, the Met Office