bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diffusion‐weighted and dynamic contrast‐enhanced MRI in evaluation of early treatment effects during neoadjuvant chemotherapy in breast cancer patients
Authors: Jensen Line R. , Garzon Benjamin , Heldahl Mariann G. , Bathen Tone F. , Lundgren Steinar , Gribbestad Ingrid S. 
Published: August 2011

AbstractPurpose:To use dynamic contrast‐enhanced (DCE) and diffusion‐weighted (DW) MRI at 3 Tesla (T) for early evaluation of treatment effects in breast cancer patients undergoing neoadjuvant chemotherapy (NAC), and assess the reliability of DW‐MRI.Materials and Methods:DW‐ and DCE‐MRI acquisitions of 15 breast cancer patients were performed before and after one cycle of NAC. MRI tumor diameter and volume, apparent diffusion coefficient (ADC) and kinetic parameters (Ktrans, ve) were derived. The reliability of ADC before NAC was assessed. Changes in MRI parameters after NAC were analyzed, and logistic regression analysis was used to find the best predictors for pathologic response.Results:The reliability for ADC values was high, with intraclass correlation coefficient of 0.84 (P = 0.001). After one cycle of NAC, MRI tumor diameter (8%, P = 0.005) and tumor volume (30%, P = 0.008) was reduced for all patients, while ADC mean values increased (0.12 mm2/s, P = 0.008). The best predictor for treatment response was a change in MRI tumor diameter with mean error rate of 0.167 (13% for responders, 5% for nonresponders, P = 0.291).Conclusion:Changes in MRI derived tumor diameter and ADC after only one cycle of NAC could provide a valuable tool for early evaluation of treatment effects in breast cancer patients. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Antibody persistence and immune memory in healthy adults following vaccination with a two‐dose inactivated hepatitis A vaccine: Long‐term follow‐up at 15 years
Authors: Van Herck Koen , Jacquet Jeanne‐Marie , Van Damme Pierre 
Published: August 2011

AbstractLong‐term persistence of vaccine‐induced immune response in adults was assessed annually for 15 years following primary immunization with a two‐dose inactivated hepatitis A vaccine. In 1992, 119 and 194 subjects aged 17–40 years and naïve for hepatitis A virus (HAV) were enrolled in two studies to receive 1,440 ELISA units (El.U) of inactivated hepatitis A vaccine (Havrix™, GlaxoSmithKline Biologicals, Belgium) according to a standard 0, 6 or an extended 0, 12 months schedule, respectively. Serum samples were taken 1 month after the second vaccine dose and every consecutive year up to 15 years after primary vaccination for measurement of anti‐HAV antibody concentrations (NCT00291876 and NCT00289757).At year 15, 100% (48/48) and 97.3% (108/111) of subjects vaccinated at 0, 6 or 0, 12 months remained seropositive for anti‐HAV antibodies, with geometric mean concentrations (GMCs) of 289.2 and 367.4 mIU/ml, respectively. An additional dose of HAV vaccine (1,440 El.U) was administered to the six subjects who had become seronegative for anti‐HAV antibodies since year 11. All subjects mounted a humoral immune response to the additional HAV challenge dose, although post‐challenge anti‐HAV antibody levels remained low in one subject.These studies represent the longest annual follow‐up of hepatitis A vaccine in healthy adults. The immune response induced by two doses of this inactivated HAV vaccine was shown to persist for at least 15 years. No difference in long‐term antibody persistence was observed between the two primary vaccination schedules, reinforcing the potential for flexibility in the timing of the second primary vaccine dose. J. Med. Virol. 83:1885–1891, 2011. © 2011 Wiley‐Liss, Inc.
Feasibility of ultra high performance supercritical neat carbon dioxide chromatography at conventional pressures
Authors: Sarazin Cédric , Thiébaut Didier , Sassiat Patrick , Vial Jérôme 
Published: August 2011

AbstractThe implementation of columns packed with sub‐2 μm particles in supercritical fluid chromatography (SFC) is described using neat carbon dioxide as the mobile phase. A conventional supercritical fluid chromatograph was slightly modified to reduce extra column band broadening. Performances of a column packed with 1.8 μm C18‐bonded silica particles in SFC using neat carbon dioxide as the mobile phase were compared with results obtained in ultra high performance liquid chromatography (UHPLC) using a dedicated chromatograph. As expected and usual in SFC, higher linear velocities than in UHPLC must be applied in order to reach optimal efficiency owing to higher diffusion coefficient of solutes in the mobile phase; similar numbers of theoretical plates were obtained with both techniques. Very fast separations of hydrocarbons are presented using two different alkyl‐bonded silica columns.
High Resolution Tip Enhanced Raman Mapping on Polymer Thin Films
Authors: Xue L. , Li W. , Hoffmann G. G. , Goossens J. G. P. , Loos J. , de With G. 
Published: August 2011

AbstractAdvanced tip enhanced Raman mapping (TERM) was applied to high resolution chemical identification on nanoscale. Thin poly(methyl methacrylate)/poly(styrene acrylonitrile) (SAN28/PMMA) blend films were measured at different stages of phase separation. New insights into the phase evolution behavior of the thin films were obtained, when the TERM images were compared. An unexpected morphology transition was observed after a few minutes annealing at 250 °C. No surface enrichment of PMMA was observed, differing from the previous reports on a similar well‐studied system of SAN33/PMMA. The glass transition temperature, the surface and interfacial tension were found to be the main factors responsible for the phase evolution behavior of SAN28/PMMA films.
Production of Core–shell Particles by Combined Semibatch Emulsion/Suspension Polymerizations
Authors: Besteti Marina Damião , Freire Denise Maria Guimarães , Pinto José Carlos 
Published: August 2011

AbstractCore–shell polymer particles were produced by combined semibatch emulsion/suspension polymerizations, using different monomers. It is shown that the morphology of the shell depends on the glass transition temperature (Tg) of the emulsified particles and that specific areas can vary considerably (7.9 to 37 m2 · g−1), depending on reaction conditions and used monomers. Particularly, a thin film is formed around the core when the Tg of the polymer that constitutes the shell is lower than the reaction temperature, while a porous shell is formed when the Tg of the polymer material is higher than the reaction temperature. Based on the observed data, a physical model was proposed to explain the formation of core–shell particles by combination of typical suspension and emulsion polymerization recipes.magnified image
In vivo multicolor molecular MR imaging using diamagnetic chemical exchange saturation transfer liposomes
Authors: Liu Guanshu , Moake Matthew , Har‐el Yah‐el , Long Chris M. , Chan Kannie W.Y. , Cardona Amanda , Jamil Muksit , Walczak Piotr , Gilad Assaf A. , Sgouros George , van Zijl Peter C.M. , Bulte Jeff W.M. , McMahon Michael T. 
Published: August 2011

AbstractA variety of (super)paramagnetic contrast agents are available for enhanced MR visualization of specific tissues, cells, or molecules. To develop alternative contrast agents without the presence of metal ions, liposomes were developed containing simple bioorganic and biodegradable compounds that produce diamagnetic chemical exchange saturation transfer MR contrast. This diamagnetic chemical exchange saturation transfer contrast is frequency‐dependent, allowing the unique generation of “multicolor” images. The contrast can be turned on and off at will, and standard images do not show the presence of these agents. As an example, glycogen, L‐arginine, and poly‐L‐lysine were encapsulated inside liposomes and injected intradermally into mice to image the lymphatic uptake of these liposomes. Using a frequency‐dependent acquisition scheme, it is demonstrated that multicolor MRI can differentiate between different contrast particles in vivo following their homing to draining lymph nodes. Being nonmetallic and bioorganic, these diamagnetic chemical exchange saturation transfer liposomes form an attractive novel platform for multicolor imaging in vivo. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Preparation of amphiphilic poly(ethylene oxide)‐block‐polystyrene macrocycles via glaser coupling reaction under CuBr/pyridine system
Authors: Zhang Yannan , Wang Guowei , Huang Junlian 
Published: August 2011

AbstractThe amphiphilic cyclic poly(ethylene oxide)‐block‐polystyrene [c‐(PEO‐b‐PS)] was synthesized by cyclization of propargyl‐telechelic poly(ethylene oxide)‐block‐polystyrene‐block‐poly(ethylene oxide) (PEO‐b‐PS‐b‐PEO) via the Glaser coupling. The hydroxyl‐telechelic ABA triblock PEO‐b‐PS‐b‐PEO was first prepared by successive living anionic polymerization of styrene and ring‐opening polymerization of ethylene oxide, and then the hydroxyl ends were reacted with propargyl bromide to obtain linear precursors with propargyl terminals. Finally, the intramolecular cyclization was conducted in pyridine under high dilution by Glaser coupling of propargyl ends in the presence of CuBr under ambient temperature, and the c‐(PEO‐b‐PS) was directly obtained by precipitation in petroleum ether with high efficiency. The cyclic products and their corresponding linear precursor PEO‐b‐PS‐b‐PEO were characterized by means of GPC, 1H NMR, and FTIR. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Effect of block molecular weight distribution on the structure formation in block copolymer/homopolymer blends
Authors: Listak Jessica , Jia Xiaolong , Plichta Andrzej , Zhong Mingjiang , Matyjaszewski Krzysztof , Bockstaller Michael R. 
Published: August 2011

AbstractThe effect of homopolymer (hP) addition on the structure formation in lamellar amorphous block copolymers (BCP) with narrow‐ and broad‐molecular weight distribution (MWD) was studied using small‐angle X‐ray scattering and transmission electron microscopy. The systems in our study consist of blends of a poly(styrene‐b‐methyl acrylate) copolymer with block‐selective broad MWD of the poly(methyl acrylate) domain as well as polystyrene and poly(methyl acrylate) hPs with molecular weight less than the corresponding block of the copolymer. Homopolymer addition to the broad MWD domain of the BCP is found to induce structural changes similar to narrow MWD BCP/hP blend systems. Conversely, addition of hP to the narrow MWD domain is found to induce a more pronounced expansion of lamellar domains due to the segregation of the hP to the center region within the host copolymer domain. With increasing hP concentration, the formation of a stable two‐phase regime with coexisting lamellar/gyroid microphases is observed that is bounded by uniform lamellar phase regimes that differ in the distribution of hP within the corresponding narrow MWD block domain. The segregation of low‐molecular weight hP to the center region of the narrowdisperse domains of a broad MWD BCP is rationalized as a consequence of the more stretched chain conformations within the narrowdisperse block that are implied by the presence of a disperse adjacent copolymer domain. The increase of chain stretching reduces the capacity of the narrowdisperse block to solubilize hP additives and thus provides a driving force for the segregation of hP chains to the center of the host copolymer domain. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 50: 106–116, 2012
Indirect Fourier Transform and Model Fitting of Small Angle Neutron Scattering from Silica Nanoparticles
Authors: Hould Nathan , Lobo Raul , Wagner Norman 
Published: August 2011

AbstractSmall angle neutron scattering (SANS) patterns from spheroidal silica nanoparticles (〈 D 〉 = 27.5 nm) dispersed in water at volume fractions ranging from 0.01 to 0.315 were interpreted using model fitting and indirect Fourier transform methods. By modeling the effective structure factor using a two‐Yukawa potential it was determined that the particles interact through weak long range attractive and shorter range repulsive inter‐particle forces. For weakly‐interacting particles (∼ 0.01 v/v) analysis of SANS patterns using a polydisperse spheres form factor is simple and accurate. However, we find that the indirect Fourier transform is a more robust method to calculate the radial distribution function for interacting particles over a broad range of particle concentrations.
Satellite cloud and precipitation assimilation at operational NWP centres
Authors: Bauer Peter , Auligné Thomas , Bell William , Geer Alan , Guidard Vincent , Heilliette Sylvain , Kazumori Masahiro , Kim Min‐Jeong , Liu Emily H.‐C. , McNally Anthony P. , Macpherson Bruce , Okamoto Kozo , Renshaw Richard , Riishøjgaard Lars‐Peter 
Published: August 2011

AbstractThe status of current efforts to assimilate cloud‐ and precipitation‐affected satellite data is summarised with special focus on infrared and microwave radiance data obtained from operational Earth observation satellites. All global centres pursue efforts to enhance infrared radiance data usage due to the limited availability of temperature observations in cloudy regions where forecast skill is estimated to strongly depend on the initial conditions. Most systems focus on the sharpening of weighting functions at cloud top providing high vertical resolution temperature increments to the analysis, mainly in areas of persistent high and low cloud cover. Microwave radiance assimilation produces impact on the deeper atmospheric moisture structures as well as cloud microphysics and, through control variable and background‐error formulation, also on temperature but to lesser extent than infrared data. Examples of how the impacts of these two observation types are combined are shown for subtropical low‐level cloud regimes. The overall impact of assimilating such data on forecast skill is measurably positive despite the fact that the employed assimilation systems have been constructed and optimized for clear‐sky data. This leads to the conclusion that a better understanding and modelling of model processes in cloud‐affected areas and data assimilation system enhancements through inclusion of moist processes and their error characterization will contribute substantially to future forecast improvement. Copyright © 2011 Royal Meteorological Society, Crown in the right of Canada, and British Crown copyright, the Met Office
SEM sample preparation for cells on 3D scaffolds by freeze‐drying and HMDS
Authors: Lee Juliana Tsz Yan , Chow King Lau 
Published: August 2011

AbstractCommon dehydration methods of cells on biomaterials for scanning electron microscopy (SEM) include air drying, hexamethyldisilazane (HMDS) or tetramethysilane (TMS) treatment and critical point drying (CPD). On the other side, freeze‐drying has been widely employed in dehydrating biological samples and also in preparing porous biomaterial scaffolds but not in preparing cells on three‐dimensional (3D) biomaterials for SEM examination. In this study, we compare cells on porous hydroxyapatite (HA) prepared by air drying, HMDS and freeze‐drying. The effects of fixation and using phosphate buffered saline (PBS) in the fixation were also assessed on three porous calcium phosphate (CaP) materials, namely, HA, α‐tricalcium phosphate (α‐TCP) and β‐tricalcium phosphate (β‐TCP) samples. There is no significant difference in samples prepared by HMDS treatment and freeze‐drying viewed at low magnification. Besides, it is better not to use phosphate buffer in the fixation step for CaP materials to avoid undesirable spontaneous precipitation of CaPs. On the other hand, fewer exchanges of liquids are required for freeze‐drying and hence chemical fixation may not be absolutely required for samples prepared by freeze‐drying. Other technical details of the preparation were also investigated and discussed. This study suggests both HMDS and freeze‐drying can be employed to dehydrate cells on 3D scaffolds for SEM examination. SCANNING 34: 12–25, 2012. © 2011 Wiley Periodicals, Inc.
Enhancing directory virtualization to detect insider activity
Authors: Claycomb William , Shin Dongwan , Ahn Gail‐Joon 
Published: August 2011

ABSTRACTOne of the critical yet lingering issues in computer security is insider threat, and it often takes advantage of some security services based on directory services such as authentication and access control. Detecting these threats is quite challenging because malicious users with the technical ability to leverage these services often have sufficient knowledge and expertise to conceal unauthorized activity. In this article, we present an approach using directory virtualization to monitor various systems across an enterprise for the purpose of detecting malicious insider activity. Specifically, a policy engine that leverages directory virtualization services is proposed to enhance monitoring and detecting capabilities by allowing greater flexibility in analyzing changes for malicious intent. The resulting architecture is a system‐based approach, where the relationships and dependencies between data sources and directory services are used to detect an insider threat, rather than simply relying on point solutions. This paper presents such an architecture in detail, including a description of implementation results. Copyright © 2011 John Wiley & Sons, Ltd.
Global software engineering and agile practices: a systematic review
Authors: Jalali Samireh , Wohlin Claes 
Published: August 2011

SUMMARYAgile practices have received attention from industry as an alternative to plan‐driven software development approaches. Agile encourages, for example, small self‐organized collocated teams, whereas global software engineering (GSE) implies distribution across cultural, temporal, and geographical boundaries. Hence, combining them is a challenge. A systematic review was conducted to capture the status of combining agility with GSE. The results were limited to peer‐reviewed conference papers or journal articles, published between 1999 and 2009. The synthesis was made through classifying the papers into different categories (e.g. publication year, contribution type, research method). At the end, 81 papers were judged as primary for further analysis. The distribution of papers over the years indicated that GSE and Agile in combination has received more attention in the last 5 years. However, the majority of the existing research is industrial experience reports in which Agile practices were modified with respect to the context and situational requirements. The emergent need in this research area is suggested to be developing a framework that considers various factors from different perspectives when incorporating Agile in GSE. Practitioners may use it as a decision‐making basis in early phases of software development. Copyright © 2011 John Wiley & Sons, Ltd.
A Generic Polymorphic Unicast Routing Protocol for vehicular ad hoc networks
Authors: Mnaouer Adel Ben , Foh Chuan Heng , Chen Lei 
Published: August 2011

ABSTRACTIn this work, we present a new generic polymorphic routing protocol tailored for vehicular ad hoc networks (VANETs). Similar to the case of mobile ad hoc networks, the routing task in VANETs comes under various constraints that can be environmental, operational, or performance based. The proposed Polymorphic Unicast Routing Protocol (PURP) uses the concept of polymorphic routing as a means to describe dynamic, multi‐behavioral, multi‐stimuli, adaptive, and hybrid routing, that is applicable in various contexts, which empowers the protocol with great flexibility in coping with the timely requirements of the routing tasks. Polymorphic routing protocols, in general, are equipped with multi‐operational modes (e.g., grades of proactive, reactive, and semi‐proactive), and they are expected to tune in to the right mode of operation depending on the current conditions (e.g., battery residue, vicinity density, traffic intensity, mobility level of the mobile node, and other user‐defined conditions). The objective is commonly maximizing and/or improving certain metrics such as maximizing battery life, reducing communication delays, improving deliverability, and so on. We give a detailed description and analysis of the PURP protocol. Through comparative simulations, we show its superiority in performance to its peers and demonstrate its suitability for routing in VANETs. Copyright © 2011 John Wiley & Sons, Ltd.
Bayesian modeling for large spatial datasets
Authors: Banerjee Sudipto , Fuentes Montserrat 
Published: August 2011

AbstractWe focus upon flexible Bayesian hierarchical models for scientific data available at geo‐coded locations. Investigators are increasingly turning to spatial process models to analyze such datasets. These models are customarily estimated using Markov Chain Monte Carlo (MCMC) methods, which have become especially popular for spatial modeling, given their flexibility and power to fit models that would be infeasible otherwise. However, estimating Bayesian spatial process models is undermined by prohibitive computational expenses associated with parameter estimation. Classes of low‐rank spatial process models are increasingly being deployed to resolve this problem by projecting spatial effects to a lower‐dimensional subspace. We discuss how a low‐rank process called the ‘predictive process’ seamlessly enters the hierarchical modeling framework and helps us accrue substantial computational benefits.WIREs Comp Stat2012, 4:59–66. doi: 10.1002/wics.187This article is categorized under:Statistical and Graphical Methods of Data Analysis > Bayesian Methods and TheoryData: Types and Structure > Image and Spatial DataStatistical and Graphical Methods of Data Analysis > Markov Chain Monte Carlo (MCMC)Data: Types and Structure > Image and Spatial Data
Catheter Fracture of Intravenous Ports and its Management
Authors: Wu Ching‐Yang , Fu Jui‐Ying , Feng Po‐Hao , Kao Tsung‐Chi , Yu Sheng‐Yueh , Li Hao‐Jui , Ko Po‐Jen , Hsieh Hung‐Chang 
Published: August 2011

AbstractBackgroundIntravenous ports are widely used for oncology patients. However, catheter fractures may lead to the need for re‐intervention. We aimed to identify the risk factors associated with catheter fractures.MethodsBetween January 1 and December 31, 2006, we retrospectively reviewed the clinical data and plain chest films of 1,505 patients implanted with an intravenous port at Chang Gung Memorial Hospital. Different vascular sites were compared using the chi‐square or Fisher’s exact test for categorical variables, and the t test was used for continuous variables with normal distribution; P < 0.05 was considered statistically significant.ResultsThere were 59 and 1,448 procedures in the fracture and non‐fracture groups, respectively. Monovariate analysis revealed that the risk factors for catheter fracture were as follows: large angle (P < 0.0001), female gender (P < 0.0008), subclavian route (P < 0.0001), and port type Arrow French (Fr.) 8.1 (P < 0.0001). Because these risk factors showed no interaction effects, they were all considered independent risk factors. When all factors were considered together, all risk factors, except angle and age, retained their statistical significance.ConclusionsMost catheter fractures were caused by material weakness. If catheter fracture is confirmed, further intervention for port and catheter removal is recommended. Female gender, intravenous port implantation via the subclavian route, and the Arrow Fr. 8.1 port were found to be risk factors. Patients with these risk factors should be monitored closely to avoid catheter fractures.